Articles de revues : « Organisation 2D »

1

Moura, Felipe Arruda, Juliana Exel Santana, Nathália Arnosti Vieira, Paulo Roberto Pereira Santiago et Sergio Augusto Cunha. « Analysis of Soccer Players’ Positional Variability During the 2012 UEFA European Championship : A Case Study ». Journal of Human Kinetics 47, n^o 1 (1 septembre 2015) : 225–36. http://dx.doi.org/10.1515/hukin-2015-0078.

Texte intégral

Résumé :

AbstractThe purpose of this study was to analyse players’ positional variability during the 2012 UEFA European Championship by applying principal component analysis (PCA) to data gathered from heat maps posted on the UEFA website. We analysed the teams that reached the finals and semi-finals of the competition. The players’ 2D coordinates from each match were obtained by applying an image-processing algorithm to the heat maps. With all the players’ 2D coordinates for each match, we applied PCA to identify the directions of greatest variability. Then, two orthogonal segments were centred on each player’s mean position for all matches. The segments’ directions were driven by the eigenvectors of the PCA, and the length of each segment was defined as one standard deviation around the mean. Finally, an ellipse was circumscribed around both segments. To represent player variability, segment lengths and elliptical areas were analysed. The results demonstrate that Portugal exhibited the lowest variability, followed by Germany, Spain and Italy. Additionally, a graphical representation of every player’s ellipse provided insight into the teams’ organisational features throughout the competition. The presented study provides important information regarding soccer teams’ tactical strategy in high-level championships that allows coaches to better control team organisation on the pitch.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Eydeland, A., et E. van Groesen. « An extended self-organisation principle for modelling and calculating the dissipation of 2D confined vortices ». Nonlinearity 2, n^o 3 (1 août 1989) : 459–75. http://dx.doi.org/10.1088/0951-7715/2/3/006.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

3

Jeulin, Dominique, et Maxime Moreaud. « SEGMENTATION OF 2D AND 3D TEXTURES FROM ESTIMATES OF THE LOCAL ORIENTATION ». Image Analysis & ; Stereology 27, n^o 3 (3 mai 2011) : 183. http://dx.doi.org/10.5566/ias.v27.p183-192.

Texte intégral

Résumé :

We use a method to estimate local orientations in the n-dimensional space from the covariance matrix of the gradient, which can be implemented either in the image space or in the Fourier space. In a second step, two methods allow us to detect sudden changes of orientation in images. The first one uses an index of confidence of the estimated orientation, and the second one the detection of minima of scalar products in a neighbourhood. This is illustrated on 2D Transmission Electrons Microscope images of cellulose cryofracture (to display the organisation of cellulose whiskers and the points of germination), and to 3D images of a TA6V alloy (lamellar microstructure) obtained by microtomography.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Badel, E., R. Bakour et P. Perré. « Investigation of the Relationships between Anatomical Pattern, Density and Local Swelling of Oak Wood ». IAWA Journal 27, n^o 1 (2006) : 55–71. http://dx.doi.org/10.1163/22941932-90000137.

Texte intégral

Résumé :

We coupled a digital X-ray imaging system with a humid air conditioner. This new configuration allows the shrinkage behaviour of thin samples to be measured. In order to control both the temperature and the relative humidity in the chamber, an air generator was developed which ensures very stable conditions even over several months. The X-ray beam passes through the chamber to the 2D detector. Twelve samples can be placed on a rotating sample holder. The strain field due to the moisture content variations is determined by an image correlation algorithm, which compares X-ray images collected at different moisture conditions. Moreover, inspection by X-ray simultaneously produces complementary data: the local density and the spatial organisation of the tissues within the anatomical pattern. Twelve oak samples, chosen for their wide variability of the anatomical pattern, were characterised using this device.Some models available in the literature are used to predict the swelling. fThe comparison between measurements and prediction is rather poor. The variable anatomical structure of the annual rings permits some explanations for this decrepancy and leads to the conclusion that the complete spatial organisation of the tissues has to be quantified to understand and to predict the behaviour of oak wood.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Klenovšek, Tina. « Modularity of the dorsal and lateral view of the skull in the European ground squirrel ». Acta Biologica Slovenica 63, n^o 1 (1 juillet 2020) : 17–23. http://dx.doi.org/10.14720/abs.63.1.15910.

Texte intégral

Résumé :

Modular organization is a general characteristic of biological systems from cellular to organismal level. The mammalian skull is a complex structure that can in general be divided into two functional components, the neurocranium and the viscerocranium. The two-module organisation of the skull of the European ground squirrel Spermophilus citellus (Linnaeus, 1766) has already been confirmed on the ventral cranium, while different studies of integration and modularity of squirrel skulls in general gave mixed results. Studies using 2D geometric morphometrics capture and analyse different views of the skull separately, and often the eventral cranial view is considered as the most suitable. In this study, the hypothesis of the two-module organisation of the S.citellus skull was re-evaluated and confirmed also on the dorsal and lateral cranial view. Nevertheless, the lateral cranium was more integrated than the dorsal cranium. Allometry had almost no effect on the pattern of modularity. This and the previous study of the S. citellus skull modularity show that different cranial views can give different results. Advisably, all three views should be considered also because the lateral view of the skull shows morphological variation in the sagittal plane that is not visible along the frontal plane, when only the ventral and/or dorsal views are considered.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Loginova, Dina B., Anastasia A. Zhuravleva et Olga G. Silkova. « Random chromosome distribution in the first meiosis of F1 disomic substitution line 2R(2D) x rye hybrids (ABDR, 4× = 28) occurs without bipolar spindle assembly ». Comparative Cytogenetics 14, n^o 4 (9 octobre 2020) : 453–82. http://dx.doi.org/10.3897/compcytogen.v14.i4.55827.

Texte intégral

Résumé :

The assembly of the microtubule-based spindle structure in plant meiosis remains poorly understood compared with our knowledge of mitotic spindle formation. One of the approaches in our understanding of microtubule dynamics is to study spindle assembly in meiosis of amphyhaploids. Using immunostaining with phH3Ser10, CENH3 and α-tubulin-specific antibodies, we studied the chromosome distribution and spindle organisation in meiosis of F1 2R(2D)xR wheat-rye hybrids (genome structure ABDR, 4× = 28), as well as in wheat and rye mitosis and meiosis. At the prometaphase of mitosis, spindle assembly was asymmetric; one half of the spindle assembled before the other, with simultaneous chromosome alignment in the spindle mid-zone. At diakinesis in wheat and rye, microtubules formed a pro-spindle which was subsequently disassembled followed by a bipolar spindle assembly. In the first meiosis of hybrids 2R(2D)xR, a bipolar spindle was not found and the kinetochore microtubules distributed the chromosomes. Univalent chromosomes are characterised by a monopolar orientation and maintenance of sister chromatid and centromere cohesion. Presence of bivalents did not affect the formation of a bipolar spindle. Since the central spindle was absent, phragmoplast originates from “interpolar” microtubules generated by kinetochores. Cell plate development occurred with a delay. However, meiocytes in meiosis II contained apparently normal bipolar spindles. Thus, we can conclude that: (1) cohesion maintenance in centromeres and between arms of sister chromatids may negatively affect bipolar spindle formation in the first meiosis; (2) 2R/2D rye/wheat chromosome substitution affects the regulation of the random chromosome distribution in the absence of a bipolar spindle.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Charmant, W. M., B. A. M. Snoeker, H. P. J. van Hout, I. N. Nauta, F. Boonstra, E. Geleijn, C. Veenhof et P. W. B. Nanayakkara. « Facilitators and barriers for the implementation of a transmural fall-prevention care pathway for older adults in the emergency department ». PLOS ONE 19, n^o 12 (31 décembre 2024) : e0314855. https://doi.org/10.1371/journal.pone.0314855.

Texte intégral

Résumé :

Background Older adults at the emergency department (ED) with fall-related injuries are at risk of repeated falls. National guidelines state that the ED is responsible for initiating fall preventive care. A transmural fall-prevention care pathway (TFCP) at the ED can guide patients to tailored interventions. In this study, we investigated the facilitators and barriers for the implementation of the TFCP for older adults following a fall-related ED visit from the perspectives of patients and healthcare professionals. Methods In this qualitative study, we used semi-structured interviews with ten older adults who had a recent ED visit due to a fall. Furthermore, we organised focus groups with 13 healthcare professionals involved in TFCP. Two researchers independently coded the transcripts using inductive thematic analysis. Results We revealed facilitators and barriers on three key themes: 1) Communication, 2) organisation & execution, and 3) personal factors, and thereunder 12 subthemes. Our specific finding were 1a) communication between healthcare professionals and patients, 1b) interprofessional communication and 1c) communication between patients and their family or friends can have both positive and negative impact on the implementation of a TFCP. For the organisation & execution, facilitators and barriers were mentioned for 2a) processes at the ED, 2b) the fall risk assessment, 2c) patient engagement, 2d) finances, 2e) time, and 2f) responsibilities. Personal factors such as 3a) emotions and behaviour, 3b) knowledge, and 3c) motivation play a crucial role in the success of patient participation. The competence of healthcare professionals in geriatric care facilitate the process of tailoring of care to patients’ needs. Conclusion When implementing a TFCP, it is crucial to be aware that facilitators and barriers from the perspective of patients and healthcare professionals exist in the processes of communication, organisation & execution, and personal factors. These factors guide the development of tailored implementation strategies in ED and primary care settings.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Wilson, Christopher J. L., Vladimir Luzin, Sandra Piazolo, Mark Peternell et Daniel Hammes. « Experimental deformation of deuterated ice in 3D and 2D : identification of grain-scale processes ». Proceedings of the Royal Society of Victoria 127, n^o 1 (2015) : 99. http://dx.doi.org/10.1071/rs15011.

Texte intégral

Résumé :

Major polar ice sheets and ice caps experience cycles of variable flow during different glacial periods and as a response to past warming. The rate and localisation of deformation inside an ice body controls the evolution of ice microstructure and crystallographic fabric. This is critical for interpreting proxy signals for climate change, with deformation overprinting and disrupting stratigraphy deep under ice caps due to the nature of the flow. The final crystallographic fabric in polar ice sheets provides a record of deformation history, which in turn controls the flow properties of ice during further deformation and affects geophysical sensing of ice sheets. For example, identification of layering in ice sheets, using seismic or ice radar techniques, is attributed to grain size changes and fabric variations. Such information has been used to provide information on climate state and its changes over time, and as the Fourth Intergovernmental Panel on Climate Change (IPCC) Report (Solomon et al. 2007) points out there is currently still a lack of understanding of internal ice-sheet dynamics. To answer this we have recently conducted experiments at the Australian Nuclear Science and Technology Organisation (ANSTO) to collect fully quantitative microstructural data from polycrystalline heavy water (D2O) ice deformed in a dynamic regime. The ice and temperature (–7°C) chosen for this study is used as a direct analogue for deforming natural-water ice as it offers a unique opportunity to link grain size and texture evolution in natural ice at –10°C. Results show a dynamic system where steady-state rheology is not necessarily coupled to microstructural and crystallographic fabric stability. This link needs to be taken into account to improve ice-mass-deformation modelling critical for climate change predictions.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Firsov, Yu G. « Modern digital hydrography and the new international hydrographic organisation bathymetric survey standards ». Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 16, n^o 1 (14 mars 2024) : 17–36. http://dx.doi.org/10.21821/2309-5180-2024-16-1-17-36.

Texte intégral

Résumé :

The current state of the International Hydrographic organization bathymetric survey Standards S44 (6.1.0) is examined in this study. The introduction of the S44 survey Standards fourth edition in 1998 heralded the beginning of a new era of modern digital hydrography based on the concept of the survey orders resulting from implementation of the Global Navigation Satellite Systems of positioning and hydrographic information systems. The fundamental changes between the 4th and 6th editions of the Standards for Hydrographic Surveys (S-44) are described. The differences between the 5th and 6th editions of the Standards for Hydrographic Surveys (S-44) are evaluated. Particular attention is paid to the conceptual evolution of such definitions as “bathymetric model” and “ features detection”. The main new S44 (6.1.0) survey Standards paradigm became the concept of “bathymetric coverage” and the rejection of the “ full sea floor coverage” concept which was introduced in the previous 5th edition. Introducing the “bathymetric coverage” and “ feature search” notions in the 6th S44 (2022) survey Standards provides the possibility to avoid the implementation of such previously important hydrographic definition as “line spacing”. It is especially emphasized that the introduction and combined application of such definitions as “bathymetric coverage”, “ feature detection” and “ feature search” necessitate the usage in the 6th S44 (2022) survey Standards of the new special tool named “specification matrix”. This tool is important for hydrographic survey drafting taking into consideration the various stakeholder requirements as well as providing a short hydrographic survey description. The introduction of gridding concept in hydrography provided in the S44 (6.1.0) survey Standards for the first time is also mentioned. Critical comments on the interpretation of gridding methods provided in the annex D which are not considered as the part of the Standards are presented. Some recommendations concerning general quality control requirements and survey posteriori quality control provided in the annex C and B are also commented on. It should be especially emphasized that three last editions of S44 Standards use the “standard deviation” term without specifying its confidence level for position uncertainty (Total Horizontal Uncertainty — THU) calculation. The position uncertainty (2D) quantities are stated as “standard deviation” multiplied by coefficient 2.45. The “standard deviation” term needs additional explanation and clarification; it should not be confused with the widely used term «position standard deviation =distance root mean squared». It is also pointed out the insufficient study of the 3D hydrographic technology provisions presented in the 6th S44 survey Standards edition associated with the alternative method of sea level correction determination based on the precise ellipsoid (geodetic) heights measurements of the tide gauges benchmarks and chart datum using GNSS observations. The necessity of inclusion of the requirements for survey posteriori quality control as the result of survey data post-processing, using statistical comparison of check lines crossing the regular lines, is substantiated. Finally, the urgency of developing new Russian hydrographic standards and specifications based on IHO S44 (6.1.0) on the basis of modern technology is emphasized.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Dumas, D., C. Gigant, N. Presle, C. Cipolletta, G. Miralles, E. Payan, J. Y. Jouzeau et al. « The role of 3D‐microscopy in the study of chondrocyte–matrix interaction (alginate bead or sponge, rat femoral head cap, human osteoarthritic cartilage) and pharmacological application ». Biorheology : The Official Journal of the International Society of Biorheology 37, n^o 1-2 (janvier 2000) : 165–76. http://dx.doi.org/10.1177/0006355x2000037001002014.

Texte intégral

Résumé :

The potentialities of a new non‐invasive optical scanning microscopy technique were evaluated through 3D analysis of chondrocyte–matrix interactions. Five different 2D or 3D culture systems were used: (1) MonoLayer (ML) of human chondrosarcoma cell line; (2) rat or human chondrocytes encapsulated in Alginate Bead (AB); (3) human chondrocytes encapsulated in Alginate Sponge (AS); (4) Rat Femoral Head Cap (RFHC); (5) slices of knee human Osteoarthritic Cartilage (HOAC). Chondrocytes ML, AB, RFHC were incubated for 24 h in vitro in the presence of recombinant human interleukin1‐β (rhIL1‐β) and the effects on cytoskeleton organisation (F‐actin filament), Focal Adhesion Kinase (FAK) expression (tyrosine kinase), collagenase B expression (metalloprotease) were studied. Furthermore, the production of intracellular IL1‐β by LPS‐ or rhIL1‐β‐stimulated chondrocytes was shown to be partly suppressed by rhein (active metabolite of diacerhein) in all culture systems. This high resolution light microscopy gave complementary information that could be important for a better understanding of the interaction of chondrocytes with the extracellular matrix in a variety of culture devices.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Siddhartha Adhikary, Rajat Bandyopadhyay, Suparna Banerjee et Amit Sarkar. « Change in the quality of life in the patients of laryngeal and pharyngeal carcinoma after receiving radiation therapy : A prospective and observational study ». Asian Journal of Medical Sciences 14, n^o 7 (1 juillet 2023) : 210–16. http://dx.doi.org/10.3126/ajms.v14i7.53400.

Texte intégral

Résumé :

Background: The quality of life (QoL) of laryngeal and pharyngeal carcinoma patients is influenced by the side effects of treatment affecting functions such as swallowing, feeding, and speech, more so following conventional radiation using 2D technique. Aims and Objectives: This study was undertaken to determine the change in QoL of laryngeal and pharyngeal cancer patients after radiation using 2D technique in a Telecobalt unit in a resource constrained peripheral institution. Materials and Methods: In this prospective, observational, and single institutional study, fifty-one larynx and pharynx cancer patients were treated with radiation/chemoradiation in telecobalt unit using conventional 2D technique. QoL was evaluated using European Organisation for Research and Treatment of Cancer Quality of Life (EORTC QLQ) C30 and EORTC QLQ Head and Neck Module (HN43) pre-validated and locally adapted questionnaires at pre-treatment, immediately, 3 months and 6 months after radiation. The difference between the scores at different time points was verified using Friedman’s non-parametric test. Results: Of the 46 evaluable patients, 71% were male with median age of 56.5 years, median follow-up of 8 months; 15 patients (32%) had Stage II disease and 78% of patients received concurrent chemotherapy. There was statistically significant deterioration of global health status and functional scales immediately after radiation. All the symptom scales of QLQ C30 and QLQ HN43 except neck swelling showed significant worsening at the end of radiation. After 6 months, the Global health status and all functional scales showed statistically significant improvement. Most symptom scales of QLQ C30 (except appetite loss and fatigue) were statistically significantly improved. At the end of 6 months, most of the symptoms showed significant improvement reaching pre-treatment values. There were however worsening of symptoms such as dry mouth, sticky saliva, and mouth opening. Conclusion: Laryngeal and pharyngeal carcinoma patients suffered from a deterioration of QoL after radiation. Six months later, most of the QoL scales showed a statistically significant improvement. These negative impacts on QoL can be reduced by use of newer techniques of radiation therapy such as 3D conformal radiotherapy, intensity-modulated radiation therapy, and image-guided radiation therapy.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Siddhartha Adhikary, Rajat Bandyopadhyay, Suparna Banerjee et Amit Sarkar. « Change in the quality of life in the patients of laryngeal and pharyngeal carcinoma after receiving radiation therapy : A prospective and observational study ». Asian Journal of Medical Sciences 14, n^o 7 (1 juillet 2023) : 210–16. https://doi.org/10.71152/ajms.v14i7.3707.

Texte intégral

Résumé :

Background: The quality of life (QoL) of laryngeal and pharyngeal carcinoma patients is influenced by the side effects of treatment affecting functions such as swallowing, feeding, and speech, more so following conventional radiation using 2D technique. Aims and Objectives: This study was undertaken to determine the change in QoL of laryngeal and pharyngeal cancer patients after radiation using 2D technique in a Telecobalt unit in a resource constrained peripheral institution. Materials and Methods: In this prospective, observational, and single institutional study, fifty-one larynx and pharynx cancer patients were treated with radiation/chemoradiation in telecobalt unit using conventional 2D technique. QoL was evaluated using European Organisation for Research and Treatment of Cancer Quality of Life (EORTC QLQ) C30 and EORTC QLQ Head and Neck Module (HN43) pre-validated and locally adapted questionnaires at pre-treatment, immediately, 3 months and 6 months after radiation. The difference between the scores at different time points was verified using Friedman’s non-parametric test. Results: Of the 46 evaluable patients, 71% were male with median age of 56.5 years, median follow-up of 8 months; 15 patients (32%) had Stage II disease and 78% of patients received concurrent chemotherapy. There was statistically significant deterioration of global health status and functional scales immediately after radiation. All the symptom scales of QLQ C30 and QLQ HN43 except neck swelling showed significant worsening at the end of radiation. After 6 months, the Global health status and all functional scales showed statistically significant improvement. Most symptom scales of QLQ C30 (except appetite loss and fatigue) were statistically significantly improved. At the end of 6 months, most of the symptoms showed significant improvement reaching pre-treatment values. There were however worsening of symptoms such as dry mouth, sticky saliva, and mouth opening. Conclusion: Laryngeal and pharyngeal carcinoma patients suffered from a deterioration of QoL after radiation. Six months later, most of the QoL scales showed a statistically significant improvement. These negative impacts on QoL can be reduced by use of newer techniques of radiation therapy such as 3D conformal radiotherapy, intensity-modulated radiation therapy, and image-guided radiation therapy.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Lersnimitthum, Purinut, Audrey Piccini, Federico Carra, Tirawat Boonyatee, Niphon Wansophark et Nopdanai Ajavakom. « Future Circular Lepton Collider Vibrational Crosstalk ». Vibration 7, n^o 4 (4 octobre 2024) : 912–27. http://dx.doi.org/10.3390/vibration7040048.

Texte intégral

Résumé :

CERN, the European Organisation for Nuclear Research is studying the feasibility of the Future Circular Collider, considering both financial and technical aspects. One of the challenges is that the performance of particle accelerators relies on the dynamic stability of structures, affected by multiple sources of vibrations, including crosstalk vibration between two particle accelerators, the Booster and Collider, in the Future Circular Lepton Collider. This research aims to find a methodology for determining transfer functions, specifically crosstalk transfer functions, between the Collider and Booster within an underground tunnel. Also, it aims to determine how significant crosstalk is compared to the vibration from other sources, such as ground vibrations. The transfer functions of the tunnel were independently determined from internal structures using the Finite Element Method, employing 2D plane strain and the standard absorbing boundary to model the underground tunnel. It was found that the overall gain of crosstalk was less than 10% of that of ground-to-magnetic axis of either the Collider or Booster. This method may be used to optimize the tunnel layout from a vibration point of view. It appears that vibrations from crosstalk are far lower compared to vibrations from ground vibrations.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Shrivastava, Shaurya, et Theresa Saxton-Fox. « Correlation between Large-Scale Streamwise Velocity Features and the Height of Coherent Vortices in a Turbulent Boundary Layer ». Fluids 6, n^o 8 (16 août 2021) : 286. http://dx.doi.org/10.3390/fluids6080286.

Texte intégral

Résumé :

The preferential organisation of coherent vortices in a turbulent boundary layer in relation to local large-scale streamwise velocity features was investigated. Coherent vortices were identified in the wake region using the Triple Decomposition Method (originally proposed by Kolář) from 2D particle image velocimetry (PIV) data of a canonical turbulent boundary layer. Two different approaches, based on conditional averaging and quantitative statistical analysis, were used to analyze the data. The large-scale streamwise velocity field was first conditionally averaged on the height of the detected coherent vortices and a change in the sign of the average large scale streamwise fluctuating velocity was seen depending on the height of the vortex core. A correlation coefficient was then defined to quantify this relationship between the height of coherent vortices and local large-scale streamwise fluctuating velocity. Both of these results indicated a strong negative correlation in the wake region of the boundary layer between vortex height and large-scale velocity. The relationship between vortex height and full large-scale velocity isocontours was also studied and a conceptual model based on the findings of the study was proposed. The results served to relate the hairpin vortex model of Adrian et al. to the scale interaction results reported by Mathis et al., and Chung and McKeon.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Agugiaro, Giorgio, Fabio Remondino, Gabrio Girardi, Jennifer Von Schwerin, Heather Richards-Rissetto et Raffaele De Amicis. « QueryArch3D : Querying and Visualising 3D Models of a Maya Archaeological Site in a Web-Based Interface ». Geoinformatics FCE CTU 6 (21 décembre 2011) : 10–17. http://dx.doi.org/10.14311/gi.6.2.

Texte intégral

Résumé :

Constant improvements in the field of surveying, computing and distribution of digital-content are reshaping the way Cultural Heritage can be digitised and virtually accessed, even remotely via web. A traditional 2D approach for data access, exploration, retrieval and exploration may generally suffice, however more complex analyses concerning spatial and temporal features require 3D tools, which, in some cases, have not yet been implemented or are not yet generally commercially available. Efficient organisation and integration strategies applicable to the wide array of heterogeneous data in the field of Cultural Heritage represent a hot research topic nowadays. This article presents a visualisation and query tool (QueryArch3D) conceived to deal with multi-resolution 3D models. Geometric data are organised in successive levels of detail (LoD), provided with geometric and semantic hierarchies and enriched with attributes coming from external data sources. The visualisation and query front-end enables the 3D navigation of the models in a virtual environment, as well as the interaction with the objects by means of queries based on attributes or on geometries. The tool can be used as a standalone application, or served through the web. The characteristics of the research work, along with some implementation issues and the developed QueryArch3D tool will be discussed and presented.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Kozłowski, M., J. Wilczak, T. Motyl et M. Gajewska. « Role of extracellular matrix and prolactin in functional differentiation of bovine BME-UV1 mammary epithelial cells ». Polish Journal of Veterinary Sciences 14, n^o 3 (1 septembre 2011) : 433–42. http://dx.doi.org/10.2478/v10181-011-0064-1.

Texte intégral

Résumé :

Role of extracellular matrix and prolactin in functional differentiation of bovine BME-UV1 mammary epithelial cells Interactions between extracellular matrix (ECM) and epithelial cells are necessary for proper organisation and function of the epithelium. In the present study we show that bovine mammary epithelial cell line BME-UV1 cultured on ECM components, commercially available as Matrigel™, constitutes a good model for studying mechanisms controlling functional differentiation of the bovine mammary gland. In contact with Matrigel BME-UV1 cells induce apicobasal polarity, and within 16 days form three dimensional (3D) acinar structures with a centrally localized hollow lumen, which structurally resemble mammary alveoli present in the functionally active mammary gland. We have shown that the 3D culture system enables a high expression and proper localisation of integrin receptors and tight junction proteins in BME-UV1 cells to be induced. This effect was not obtained in cells grown in the classical 2D culture system on plastic. Moreover, ECM highly stimulated the synthesis of one of the major milk proteins, β-casein, even in the absence of prolactin. Our results show that contact with ECM plays an important role in the lactogenic activity of bovine MECs, however, prolactin is necessary for the efficient secretion of milk proteins.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Rossado Espinoza, Verónica Paola, Daniel Cardenas-Salas, Angela Cabrera et Lucía Coronel. « Virtual Reality and BIM Methodology as Teaching- Learning Improvement Tools for Sanitary Engineering Courses ». International Journal of Emerging Technologies in Learning (iJET) 16, n^o 06 (30 mars 2021) : 20. http://dx.doi.org/10.3991/ijet.v16i06.13535.

Texte intégral

Résumé :

Virtual Reality (VR) is the term often used to describe a 3D environment where objects and images of the real world are simulated through technology. In Architecture or Civil Engineering, the design process with 2D planes could lead to error due to misinterpretation in the visualisation of elements. The civil engineering programme of a University mandates teaching of the BIM methodology in all courses, allowing the students to learn about the organisation and optimisation of projects from design to construction. The engineering students are required to manage many variables with BIM methodology, especially in mechanical, electrical and plumbing systems (MEP). Nevertheless, the BIM´s teaching method could be enriched by analysing 3D project models using virtual reality (VR). Whereas BIM organises and optimises a project through a 3D model, VR can introduce the user into a model very close to reality, improving the interpretation and analysis of details. The present study contributes to the implementation of a Plumbing Engineering course in a Civil Engineering programme. The proposed methodology was applied in an experimental group of undergraduate students and test results compared with a corresponding group that made used of a traditional approach. Based on the results of the study, students can visualise the accessories and recognise a good design in a creative and innovative way using the VR–BIM method

Styles APA, Harvard, Vancouver, ISO, etc.

18

Paule, S. G., L. Kilpatrick, A. N. Stephens et G. Nie. « 171. IDENTIFICATION OF DECIDUALISATION-INDUCED PROTEIN CHANGES IN HUMAN ENDOMETRIAL STROMAL CELLS BY PROTEOMICS ». Reproduction, Fertility and Development 21, n^o 9 (2009) : 89. http://dx.doi.org/10.1071/srb09abs171.

Texte intégral

Résumé :

Decidualisation of human endometrial stromal cells (HESC) is pivotal for successful implantation and can be induced by cAMP analogues such as 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) and ligands to enhance cellular cAMP levels. The resulting decidualisation HESC is recognised by morphological changes and cellular products such as prolactin or insulin-like growth factors. The regulation of proteins during decidualisation HESC has yet to be clearly identified. The aim of this study was to identify proteins that are altered during decidualisation. HESC were isolated and decidualised with 500μM of 8-Br-cAMP for 72 hours. Decidualisation success was determined by prolactin assay. 2D differential in-gel electrophoresis (DIGE) was used to examine differentially expressed proteins between control and 8-Br-cAMP treated HESC. The proteins of interest were validated by Western blot and/or immunohistochemistry. A total of 88 differentially expressed proteins were identified by matrix assisted laser desorption/ionisation (MALDI) and/or liquid chromatography mass spectrometry (LC-MS). The proteins that were up regulated during decidualisation include insulin growth factor binding protein as well as caldesmon, tropomycin, actin, tubulin, SRC substrate cortactin and calponin-1 which contribute to the re-organisation of cell cytoskeletal restructuring and remodelling. Proteins associated with cellular growth and transformation such as annexin, nuclear migration factor protein and elongation factor 1B were also up regulated. These results suggest that the process of decidualisation is complicated requiring synergy and cross-talk between structural and cell growth proteins and pathways.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Jasztal, Michał. « Testing the Process of Evacuation from the Passenger Aircraft with the Use of Computer Simulation ». Safety & ; Fire Technology 56, n^o 2 (2020) : 22–39. http://dx.doi.org/10.12845/sft.56.2.2020.2.

Texte intégral

Résumé :

Aim: The main aim of the study was to investigate the possibility to use the Pathfinder simulation software to determine the duration of an evacuation and to plan its course for various scenarios of evacuation organisation, for specific profiles and behaviours of passengers and on-board personnel, and for a specific geometrical arrangement of the passenger cabin of a selected passenger aircraft. In addition, the paper discusses selected factors that affect the evacuation from the passenger aircraft. Project and methods: The Pathfinder software used in the research has the graphical interface to create an evacuation simulation model (2D and 3D) as well as tools to visualise the results. Pathfinder is based on artificial intelligence algorithms, in which each passenger has a number of individual features that can influence his/her movements and decisions during the simulation. The simulation of people's movement is determined by their profiles and behaviours, the parameters of which can be entered by means of probability distributions, which makes it possible to take into account the stochastic nature of the evacuation process. Results: The Boeing 787 Dreamliner was selected for the study, for which six options for simulating the evacuation of 252 passengers and eight members of on-board personnel were conducted. The shortest evacuation time was achieved by changing the even distribution of the number of passengers to the individual emergency exits, thus avoiding congestions in sensitive areas of the passenger cabin. The increase in passengers' maximum speed has paradoxically increased evacuation times, as it has increased the intensity of passenger collisions. It was found that one of the key issues affecting the timing of an evacuation is the proper organisation of the evacuation by on-board personnel, who, by guiding passengers through the geometrically most advantageous passageways, results in the fastest possible evacuation. The simulations in variants five and six have achieved satisfactory evacuation times, which are within the emergency aircraft evacuation time limit required in a certification process. Conclusions: The presented simulation models, the results obtained, and the wide range of possibilities of three-dimensional visualisation of research results give a rational basis for the use of Pathfinder software for testing the evacuation process and thus: for the usage in the aircraft design process, for preparing aircrafts for tests, for shaping evacuation procedures, for on-board personnel training and for air accident investigation.

Styles APA, Harvard, Vancouver, ISO, etc.

20

Dechantsreiter, Susanne, Ashley Ambrose, Edith M. Hessel, Soren Beinke, Gillian Tannahill et Daniel M. Davis. « Activation-induced cell protrusions and vesicle secretion of human lung macrophages revealed by super-resolution microscopy ». Journal of Immunology 204, n^o 1_Supplement (1 mai 2020) : 149.1. http://dx.doi.org/10.4049/jimmunol.204.supp.149.1.

Texte intégral

Résumé :

Abstract Recent studies using super-resolution microscopy have established that the organisation of immune cell receptors impacts signal integration and cellular activation. Understanding the nano-scale dynamics of surface receptors on tissue specific macrophages is especially important, as they are phenotypically diverse and possess a large repertoire of receptors. However, tissue macrophages are highly auto-fluorescent, severely limiting the utility of light microscopy. Here, we report a novel correction technique which utilises a moving median filter to remove auto-fluorescent noise from stochastic optical reconstruction microscopy datasets. Using this, we visualised lung macrophages (LMs) activated through Fc receptors by IgG-coated glass slides, representing a 2D model of the phagocytic synapse. This unexpectedly revealed the formation of protrusions, at the surface of LMs but not blood-derived macrophages. Class I MHC protein accumulated at the tips, consistent with a role for macrophage protrusions in antigen presentation. Additionally, staining for the exosome marker CD81 revealed the secretion of extracellular vesicles. Classically, cell-derived vesicles are studied after bulk isolation, which is harsh and comes with many caveats. Imaging them directly upon secretion allows analysis of their properties on a cell-by-cell basis in a near-native state. We discovered that LM vesicles appeared distinct from those secreted from blood-derived macrophages in that their average diameter was much smaller (80 nm ± 19 nm vs. 159 nm ± 78 nm). Thus, our correction method for super-resolution microscopy revealed novel cell biology – protrusion formation and vesicle secretion – triggered upon activation of human LMs.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Moshkelgosha, Sajad, Giulia Masetti, Utta Berchner-Pfannschmidt, Hedda Verhasselt, Mareike Horstmann, Salvador Diaz-Cano, Alistair Noble et al. « Gut Microbiome in BALB/c and C57BL/6J Mice Undergoing Experimental Thyroid Autoimmunity Associate with Differences in Immunological Responses and Thyroid Function ». Hormone and Metabolic Research 50, n^o 12 (14 août 2018) : 932–41. http://dx.doi.org/10.1055/a-0653-3766.

Texte intégral

Résumé :

AbstractExperimental models of hyperthyroid Graves’ disease (GD) and Graves’ orbitopathy (GO) are efficiently developed by genetic immunisation by electroporation with human thyrotropin hormone receptor (hTSHR) A-subunit plasmid in female BALB/c (H-2d) mice. We investigated susceptibility in C57BL/6 J (H-2b) animals to allow studies on disease mechanisms in transgenic and immune response gene knock-out mice. Higher numbers of female C57BL/6 J were positive for pathogenic thyroid stimulating antibodies, but induced hyperthyroidism remained at a low frequency compared to BALB/c animals. Assessment of hTSHR specific T cells showed reduced proliferation in C57BL/6 J animals accompanied with anti-inflammatory IL-10, with less pro-inflammatory IFN-γ compared to BALB/c. Whilst the orbital tissue from immune BALB/c mice showed inflammation and adipogenesis, in contrast C57BL/6 J animals showed normal pathology. We characterised the gut microbiota using 16 S ribosomal RNA gene sequencing to explore its possible pathogenic role in the model. Despite being housed under identical conditions, we observed significantly different organisation of the microbiota (beta-diversity) in the two strains. Taxonomic differences were also noted, with C57BL/6 J showing an enrichment of Operational Taxonomic Units (OTUs) belonging to the Paludibacter and Allobaculum, followed by Limibacter, Anaerophaga and Ureaplasma genera. A higher number of genera significantly correlating with clinical features was observed in C57BL/6 J compared to BALB/c; for example, Limibacter OTUs correlated negatively with thyroid-stimulating antibodies in C57BL/6 J mice. Thus, our data suggest gut microbiota may play a pivotal immunomodulatory role that differentiates the thyroid function and orbital pathology outcome in these two inbred strains undergoing experimental GO.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Wimalawansa, Sunil J. « Rapidly Increasing Serum 25(OH)D Boosts the Immune System, against Infections—Sepsis and COVID-19 ». Nutrients 14, n^o 14 (21 juillet 2022) : 2997. http://dx.doi.org/10.3390/nu14142997.

Texte intégral

Résumé :

Vitamin D deficiency is a global public health problem, a pandemic that commonly affects the elderly and those with comorbidities such as obesity, diabetes, hypertension, respiratory disorders, recurrent infections, immune deficiency, and malignancies, as well as ethnic minorities living in temperate countries. The same groups were worst affected by COVID-19. Since vitamin D deficiency weakens the immune system, it increases the risk of infections, complications, and deaths, such as from sepsis and COVID-19. Deficiency can be remedied cost-effectively through targeted food fortification, supplementation, and/or daily safe sun exposure. Its endocrine functions are limited to mineral metabolism, musculoskeletal systems, specific cell membrane interactions, and parathyroid gland functions. Except for the rapid, endocrine, and cell membrane-based non-genomic functions, all other biological and physiological activities of vitamin D depend on the adequate intracellular synthesis of 1,25(OH)2D (calcitriol) in peripheral target cells via the genome. Calcitriol mediates autocrine (intracrine) and paracrine signalling in immune cells, which provides broader, protective immune functions crucial to overcoming infections. The synthesis of 1,25(OH)2D (calcitriol) in peripheral target cells is dependent on diffusion and endocytosis of D3 and 25(OH)D from the circulation into them, which requires maintenance of serum 25(OH)D concentration above 50 ng/mL. Therefore, in acute infections such as sepsis and respiratory infections like COVID-19, it is necessary to rapidly provide its precursors, D3 and 25(OH)D, through the circulation to generate adequate intracellular calcitriol. Immune defence is one of the crucial non-hormonal functions of vitamin D. A single oral (bolus) dose or divided upfront loading doses between 100,000 and 500,000 IU, using 50,000 IU vitamin D3 increase the serum 25(OH)D concentrations to a therapeutic level of above 50 ng/mL that lasts between two to three months. This takes three to five days to raise serum 25(OH)D. In contrast, a single oral dose of calcifediol (0.014 mg/kg body weight) can generate the needed 25(OH)D concentration within four hours. Considering both D3 and 25(OH)D enter immune cells for generating calcitriol, using the combination of D3 (medium-term) and calcifediol (immediate) is cost-effective and leads to the best clinical outcome. To maximise protection against infections, particularly to reduce COVID-19-associated complications and deaths, healthcare workers should advise patients on safe sun exposure, adequate vitamin D supplementation and balanced diets containing zinc, magnesium, and other micronutrients to support the immune system. Meanwhile, governments, the World Health Organisation, the Centers for Disease Control, and governments should consider similar recommendations to physicians and the public, change the outdated vitamin D and other micronutrient recommendations directed to their population, and organise targetted food fortification programs for the vulnerable groups. This article discusses a rational approach to maintaining a sustained serum 25(OH)D concentration above 50 ng/mL, necessary to attain a robust immune system for overcoming infections. Such would cost-effectively improve the population’s health and reduce healthcare costs. It also describes three cost-effective, straightforward protocols for achieving and sustaining therapeutic serum 25(OH)D concentrations above 50 ng/mL (>125 nmol/L) to keep the population healthy, reduce absenteeism, improve productivity, and lower healthcare costs.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Roterman, Irena, Katarzyna Stapor et Leszek Konieczny. « Secondary Structure in Amyloids in Relation to Their Wild Type Forms ». International Journal of Molecular Sciences 24, n^o 1 (21 décembre 2022) : 154. http://dx.doi.org/10.3390/ijms24010154.

Texte intégral

Résumé :

The amyloid structures and their wild type forms, available in the PDB database, provide the basis for comparative analyses. Globular proteins are characterised by a 3D spatial structure, while a chain in any amyloid fibril has a 2D structure. Another difference lies in the structuring of the hydrogen bond network. Amyloid forms theoretically engage all the NH and C=O groups of the peptide bonds in a chain with two hydrogen bonds each. In addition, the hydrogen bond network is highly ordered—as perpendicular to the plane of the chain. The β-structure segments provide the hydrogen bond system with an anti-parallel system. The folds appearing in the rectilinear propagation of the segment with the β-structure are caused by just by one of the residues in the sequence—residues with a Rα-helical or Lα-helical conformation. The antiparallel system of the hydrogen bonds in the β-structure sections at the site of the amino acid with a Rα- or Lα-helical conformation changes into a parallel system locally. This system also ensures that the involvement of the C=O and H-N groups in the construction of the interchain hydrogen bond, while maintaining a perpendicular orientation towards the plane of the chain. Conformational analysis at the level of the Phi and Psi angles indicates the presence of the conditions for the structures observed in the amyloids. The specificity of amyloid structures with the dominant conformation expressed as |Psi| = |Phi| reveals the system of organisation present in amyloid fibrils. The Phi, Psi angles, as present in this particular structure, transformed to form |Psi| = |Phi| appear to be ordered co-linearly. Therefore, the calculation of the correlation coefficient may express the distribution around this idealised localisation on the Ramachandran map. Additionally, when the outstanding points are eliminated, the part of amyloid chain can be classified as fulfilling the defined conditions. In addition, the presentation of the chain structure using geometric parameters, V-angle—the angle between the planes of the adjacent peptide bonds (angle versus the virtual axis Cα-Cα) and the radius of the curvature R, depending on the size of the angle V, allows for a quantitative assessment of changes during amyloid transformation.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Shahneh, Amir Zare. « Analysis of Onset of Transition Region on a Supersonic Wing ». Middle East Research Journal of Engineering and Technology 1, n^o 1 (20 décembre 2021) : 1–8. http://dx.doi.org/10.36348/merjet.2021.v01i01.001.

Texte intégral

Résumé :

Abstract: Climate change is due to the sole effect of global warming, which is an outcome of Green House Gas (GHG) emissions. The aviation industry is considered to be one of the fastest-growing sources of these emissions. Mitigation of these emissions is a challenging task since it requires the entire world to work hand-in-hand. The International Civil Aviation Organisation (ICAO), an international governing body, has come up with a challenging target of net 50% reduction in global aviation emission by 2050, relative to the emission levels in 2005. To achieve this target, there must at least be 2% improvement in fuel efficiency every year. This 2% efficiency improvement is further split into Aircraft technology improvement (1.1%) and Airport infrastructure improvement (0.9%). This research aims to achieve the 2% improvement by aircraft technology improvement. Over the years, it was evidenced that mitigation of skin-friction drag on the wing would contribute to a majority of the fuel efficiency improvement. Hence, the primary aim is narrowed down to wing skin friction drag. The theory of boundary-layer has been studied thoroughly in this research work. Also, the interaction between the shock-waves and boundary-layer will be briefed in this paper as the baseline aircraft is supersonic. As it was understood as understood over the research that extension of the laminar boundary-layer favours the reduction of skin-friction drag, it is the primary objective of this research work. A Computational Fluid Dynamics (CFD) study on the of the wing aerodynamics has been conducted to enhance the performance of the aircraft and ANSYS Fluent has been used to serve this purpose. The results obtained from ANSYS fluent will be validated in one of the NASA’s open-source tool VSPAero which uses Vortex Lattice Method to model the flow. Turbulent Kinetic Energy technique is used to predict the onset of the transition of the flow. Initial study is performed on the 2D aerofoil and one the most optimum aerofoil is obtained, the study is continued in 3D to understand the effect of cross-flow instabilities. Free-stream velocity profile variation is another reliable technique in predicting the transition and will be discussed in the next volume of the paper. Finally, aerodynamic performance analysis will be performed to obtain the best wing configuration.

Styles APA, Harvard, Vancouver, ISO, etc.

25

Carlyle, Jo-anne, Jolita Buzaityte-Kašalyniene, Erika Speičytė-Ruschhoff et Chris Tanner. « “… When what’s needed is imagination” : using remote platforms for group relations and organisational practices ». Organisational and Social Dynamics 22, n^o 1 (19 juin 2022) : 28–45. http://dx.doi.org/10.33212/osd.v22n1.2022.28.

Texte intégral

Résumé :

This article positions itself at a particular moment in time to benchmark the shift to online working for group relations and organisational consultancy practices. Drawing on varied experiences of working online during the global pandemic of 2020, the authors describe the impact that remote working is having on traditional assumptions about systems-psychodynamic work. It contributes to an appraisal of what different approaches are needed in the online sphere. It discusses the oppor-tunities for more global participation and the current challenges to existing cultural assumptions. The article is structured around the themes of: setting the scene—opening the window to online working; losing and finding ourselves in the online space; the renaissance of lateral approaches to leadership; the question of where the unconscious goes in 2D space; and finally looks at implications for structuring the online space, including design issues for workshops and conferences.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Tiwari, A., A. Rauf, S. Kesavan, M. Kappanayil, S. Sivadas, S. Balan et P. Chickermane. « POS1262 A COHORT STUDY OF COVID-19 RELATED MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN AND ADOLESCENTS FROM MULTIPLE TERTIARY CARE CENTRES IN SOUTH INDIA ». Annals of the Rheumatic Diseases 80, Suppl 1 (19 mai 2021) : 915.2–916. http://dx.doi.org/10.1136/annrheumdis-2021-eular.4034.

Texte intégral

Résumé :

Background:After the peak of COVID 19 pandemic, a surge of cases with multi-system involvement and hyperinflammatory state was reported in children, at multiple tertiary care centers across the world. (1) This COVID-19 associated multisystem inflammatory syndrome in children and adolescents is also known as multisystem inflammatory syndrome in children (MIS-C). There is a paucity of literature of clinical profile of MIS-C patients from India.Objectives:To study the clinical manifestations and treatment outcomes of COVID-19 related multisystem inflammatory syndrome in children (MIS-C) and adolescents.Methods:It was a cohort study including cases defnied as per the case definitions of MIS-C by World Health Organisation (WHO) or Centre for Disease Control and Prevention(CDC).(2)The clinical parameters, laboratory parameters (including inflammatory markers, D dimer and NT ProBNP), electrocardiogram, 2D echocardiogram, course in hospital, and immediate outcomes were noted.Results:Twenty five patients (male-14) with a mean age of 6.22 ±4.25 years and a mean body mass index of 16.21 ±3.36 kg/m2 were enrolled on the study. Average length of hospital stay was 8.12±5.76 days. Associated comorbidities were present in 4 of our patients (16%). Figure 1 shows the frequency of clinical features in our study patients. Table 1 shows the clinical, laboratory, imaging findings, disease course and outcomes.Figure 1.Frequency of clinical features in our MIS-C cohort patientsTable 1.Clinical characteristics of MIS-C patients (n)=25Clinical Phenotypes:Incomplete/ Atypical Kawasaki Disease (KD)18 (72%)Macrophage activation syndrome (MAS)11 (44%)Unexplained Shock13 (52%)Fever with gastrointestinal symptoms17 (68%)Fever with neurological symptoms9 (36%)Fever with respiratory symptoms5 (20%)COVID chronology:MISC with acute COVID 19 with MAS1 (4%)MISC with acute COVID 19 with incomplete/atypical KD1 (4%)COVID 19 tests:COVID 19 RTPCR positive2 (8%)COVID 19 RTPCR negative23 (92%)COVID 19 IgG positive20 (80%)COVID 19 IgM positive6 (24%)COVID 19 IgG and IgM both positive2 (8%)COVID 19 IgG and IgM not done4 (16%)Other laboratory investigations(Peak/ trough values):Anaemia20 (80%)Leukopenia2 (8%)Thrombocytopenia6 (24%)Pancytopenia2 (8%)Positive CRP23 (92%)High Procalcitonin9 (36%)High ferritin10 (40%)High D- dimer17 (68%)High NT ProBNP23 (92%)Hypoalbuminemia14 (56%)Sterile pyuria7 (28%)Proteinuria4 (16%)Cardiac assessment:Abnormal Electrocardiogram (ECG)5 (20%)Abnormal Echocardiography15 (60%)Coronary dilation/prominence/non-tapering9 (36%)Coronary aneurysm1 (4%)LAD Z score (Mean±SD)2.12 ± 1.11Decreased Ejection fraction (EF)5 (20%)Systolic Dysfunction5 (20%)Pericardial effusion9 (36%)Global/septal hypokinesia4 (16%)Mitral Valve regurgitation3 (12%)Complete heart block1 (4%)Twenty patients (80%) had severe illness requiring intensive care. Fourteen patients (56%) required inotropic support, 8 patients (32%) required supplemental oxygen, 5 patients (20%) required mechanical ventilation and 2 patients (8%) expired. A total of 23 patients (92%) received pulse steroids followed by oral/iv steroids, 22 patients (88%) received IVIG (2g/kg) and 3 patients (12%) required anticoagulation.Conclusion:Our MIS-C cohort had varied clinical manifestations ranging from the mild cutaneous and gastrointestinal symptoms to fatal multiorgan dysfunctions. In contrast to western cohorts, our study cohort had higher number of patients from younger age group and lower BMI.References:[1]Ahmed M, Advani S, Moreira A, Zoretic S, Martinez J, Chorath K et al. Multisystem inflammatory syndrome in children: A systematic review. EClinicalMedicine. 2020;26:100527.[2]Jiang L, Tang K, Levin M, Irfan O, Morris S, Wilson K et al. COVID-19 and multisystem inflammatory syndrome in children and adolescents. The Lancet Infectious Diseases. 2020;20(11):e276-e288.Disclosure of Interests:None declared

Styles APA, Harvard, Vancouver, ISO, etc.

27

Borda D’água, J., A. P. Cláudio, M. B. Carmo, M. Guerreiro, A. Cavaco, D. Piedade, C. F. Gomes, A. Pais et E. Mateus. « POS0068-PARE VITORIA, A VIRTUAL ASSISTANT TO PROMOTE EDUCATION AND AWARENESS ON JUVENILE RHEUMATIC MUSCULOSKELETAL DISEASES ». Annals of the Rheumatic Diseases 82, Suppl 1 (30 mai 2023) : 245.1–245. http://dx.doi.org/10.1136/annrheumdis-2023-eular.5927.

Texte intégral

Résumé :

BackgroundThe range of musculoskeletal and connective tissue conditions that manifest in children is referred to as paediatric rheumatic diseases[1]. Juvenile idiopathic arthritis (JIA) is the most common childhood chronic rheumatic disease[2]. This disease is the most frequent cause of chronic pain in young people, which negatively affects their quality of life. To mitigate the burden of chronic condition, self-management (e.g., lifestyle) should be combined with medical management. More effective information strategies are required to respond to the needs of those living with rheumatic diseases and their caregivers. Virtual Humans (VH) have been utilized in interactive computational simulations to boost users’ acceptability and knowledge of health conditions while also promoting lifestyle changes in healthy individuals or in the management of chronic illnesses, such as juvenile rheumatic musculoskeletal diseases (RMDs)[3,4].ObjectivesThis project aimed to develop a web application to support education for disease management and health promotion, in children and young people with RMDs, their caregivers and peers[5].MethodsThe use of gamification as well as a virtual character incorporated in a narrative, with the dual goal of maintaining user engagement and improving the play experience, was the core idea underpinning the development of our application. Group discussions with youngsters (members of the patient organisation ANDAI) were used to obtain feedback and experiences from application users during the requirement phase, intermediate feedback and testing the developed application. The application was also assessed by an evaluation survey following the testing phase.ResultsA virtual assistant was developed to communicate with users through speech (voice and subtitles) as well as face and body motions[6]. This 2D animated young female model, portrays a character with juvenile RMDs and shares information about her lived experiences with the illness. An assessment of user knowledge follows each interaction. Users are encouraged to play and learn more by awarding points and digital badges for right answers or by displaying the solutions when incorrect answers are chosen. In short, on a scale of 1 to 5, 83% of the participants in application testing rated the application with maximal punctuation, indicating that users, which were children with RMDs, their young relatives and/or friends, found this tool useful.ConclusionA virtual assistant web application that uses a narrative approach and gamification concepts to encourage education on juvenile RMDs was successfully developed. This web application is intended to be lodged on the ANDAI website to convey easy access. In addition, this tool will be also made available in tablets at the waiting room of paediatric rheumatology services, facilitating education when children are diagnosed.References[1]Davies, K. & Copeman, A. The spectrum of paediatric and adolescent rheumatology.Best Pract. Res. Clin. Rheumatol.20, 179–200 (2006).[2]EULAR RheumaMap Task Force.RheumaMap A Research Roadmap to transform the lives of people with Rheumatic and Musculoskeletal Diseases Prepared by a European League Against Rheumatism Taskforce. (2019).[3]Wonggom, P., Kourbelis, C., Newman, P., Du, H. & Clark, R. A. Effectiveness of avatar-based technology in patient education for improving chronic disease knowledge and self-care behavior: A systematic review.JBI Database Syst. Rev. Implement. Reports17, 1101–1129 (2019).[4]Walters, R., Leslie, S. J., Polson, R., Cusack, T. & Gorely, T. Establishing the efficacy of interventions to improve health literacy and health behaviours: A systematic review.BMC Public Health20, 1–17 (2020).[5]D’Água, J. B. B. Personagem virtual numa abordagem digital para apoio a jovens com doença reumática, MSc Thesis in Informatics;https://repositorio.ul.pt/handle/10451/53774. (Universidade de Lisboa, Faculdade de Ciências, 2021).[6]Vitoria.http://www.di.fc.ul.pt/~apc/VITORIA_ANDAI/Site/Website/inicio.html.Acknowledgements:NIL.Disclosure of InterestsNone Declared.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Sandersen, Peter B. E., Thomas Vangkilde-Pedersen, Flemming Jørgensen, Richard Thomsen, Jørgen Tulstrup et Johnny Fredericia. « Towards a national 3D geological model of Denmark ». Geological Survey of Denmark and Greenland (GEUS) Bulletin 35 (15 juillet 2016) : 27–30. http://dx.doi.org/10.34194/geusb.v35.4900.

Texte intégral

Résumé :

As part of its strategy, the Geological Survey of Denmark and Greenland (GEUS) is to develop a national, digital 3D geological model of Denmark that can act as a publicly accessible database representing the current, overall interpretation of the subsurface geology. A national model should be under constant development, focusing on meeting the current demands from society. The constant improvements in computer capacity and software capabilities have led to a growing demand for advanced geological models and 3D maps that meet the current technical standards (Berg et al. 2011). As a consequence, the users expect solutions to still more complicated and sophisticated problems related to the subsurface. GEUS has a long tradition of making 2D maps of subsurface layer boundaries and near-surface geology (Fredericia & Gravesen 2014), but in the change from 2D to 3D and when combining data in new ways, new geological knowledge is gained and new challenges of both technical and organisational character will arise. The purpose of this paper is to present the strategy for the national 3D geological model of Denmark and the planned activities for the years ahead. The paper will also reflect on some of the challenges related to making and maintaining a nationwide 3D model. Initially, the model will only include the Danish onshore areas, with the Danish offshore areas and Greenland to be added later using a similar general setup.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Mota, Luis Carlos Martins de Almeida, et António Gomes Ferreira. « A FORMAÇÃO DE PROFESSORES EM PORTUGAL NO QUADRO DO ESPAÇO EUROPEU DE ENSINO SUPERIOR ». Revista Observatório 3, n^o 6 (1 octobre 2017) : 38. http://dx.doi.org/10.20873/uft.2447-4266.2017v3n6p38.

Texte intégral

Résumé :

RESUMO A alteração do quadro legal de formação de professores e educadores ocorreu num contexto de desenvolvimento de dinâmicas de globalização hegemónica (Santos, 2001). Neste contexto o Estado-nação tem perdido centralidade, emergindo entidades económico-políticas regionais de natureza supranacional na tentativa de os estados ampliarem a sua influência nas dinâmicas de globalização (Jessop, 2005). A União Europeia, forma avançada de “Estado em rede” (Castells, 2007), apresenta-se como a configuração institucional mais desenvolvida e tem afirmado um papel crescente nas políticas sociais, e. g., a educação (Moutsios, 2009). No processo de transnacionalização da educação certas organizações internacionais e supranacionais têm ganho crescente relevo, e. g. Organização Mundial do Comércio (OMC) ou a Organização para a Cooperação e Desenvolvimento Económico (OCDE). Neste âmbito, e cujo mandato contempla funções regulatórias, destaca-se a União Europeia (UE). No seio da UE os programas de educação e formação incluem as iniciativas no contexto da plataforma intergovernamental Processo de Bolonha (Conselho da União Europeia, 2009a). Neste contexto têm vindo a ser adotadas medidas consideradas chave para estruturar o Espaço Europeu de Educação Superior (EEES) (Bergen, 2005), como a definição do Sistema Europeu de Acumulação e Transferência de Créditos (ECTS), acompanhada da adoção de um sistema único de graus, com a (sugestão de) adoção do modelo anglo-saxónico, na modalidade 3 + 2 anos, i. é, 180 + 120 ects, nos dois primeiros ciclos, e a implementação de um sistema de avaliação garantidor de qualidade e acreditação, com base em entidades e procedimentos que se desejam articulados nacional e transnacionalmente (Antunes, 2008). Centramo-nos na discussão das opções de política educativa para a formação de professores de crianças dos 3 aos 12 anos de idade, em Portugal, aferindo o grau de autonomia nas vias de consecução do processo de europeização pela evolução das soluções implementadas ao nível das condições de acesso, dos objetivos e da estrutura da formação – duração, vertentes e pesos dos domínios do saber específico dos professores, do saber psicopedagógico e da prática educativa – no âmbito da oferta formativa de 1º e 2º ciclo. Para o efeito, para além da revisão bibliográfica considerada pertinente, procedemos à análise documental de um conjunto diversificado de fontes entre os documentos dimanados das instituições internacionais e supranacionais, de grupos de trabalho e plataformas intergovernamentais – estudos, relatórios, inquéritos e seus resultados, programas, projetos, tratados, etc. –, bem como a produção legislativa sobre problemática, dos últimos governos de Portugal, no sentido de clarificar princípios e opções de política educativa no domínio da formação de professores, nomeadamente ao nível do recrutamento, do perfil profissional e da organização dos planos de estudo e da oferta educativa. Genericamente, o processo de europeização tem contribuído para uma certa convergência das políticas educativas, com impacto no ensino superior português e ao nível da formação inicial de professores. As alterações políticas geraram cambiantes nos regimes jurídicos de formação inicial de educadores e professores ilustrando a permanência do Estado como regulador, no plano nacional, como contraponto a uma regulação transnacional da educação. Uma perspetiva do professor como profissional autónomo dotado de atitude crítica, capaz de avaliar a sua atuação, que investiga e constrói reflexivamente o seu saber profissional, aparenta deslizar para uma visão mais técnica do trabalho do professor, orientada para e pelos resultados. A formação apresenta uma estrutura bietápica, mas com inegável integração das dimensões de formação prevalecendo, no entanto, a tradição portuguesa de modelos estruturais em detrimento dos concetuais (Ferreira e Mota, 2013). Desde novembro de 2015 que o contexto político, em Portugal, se alterou e, na educação, diversas medidas têm sido revertidas. Contudo, a formação de professores permanece inalterável. PALAVRAS-CHAVE: Processo de Bolonha; Espaço europeu de educação superior; Formação de professores. ABSTRACT The change of the legal framework for the training of teachers and educators occurred within a context of development of hegemonic globalisation dynamics (Santos, 2001). In this context, the nation-state has lost its centrality, and regional economic-political entities of a supranational nature have emerged in an attempt for states to increase their influence on globalisation dynamics (Jessop, 2005). The European Union, an advanced form of ‘Network State’ (Castells, 2007), presents itself as the most developed institutional configuration and has affirmed an increasing role in social policies, e.g., in education (Moutsios, 2009). Within the process of transnationalisation of education, certain international and supranational organisations have gained increasing importance, including the World Trade Organisation (WTO) or the Organisation for Economic Cooperation and Development (OECD). In this context, the European Union (EU) stands out with a mandate that includes regulatory functions. Within the EU, education and training programs include initiatives in the context of the intergovernmental Bologna Process (Council of the European Union, 2009a). In this framework, key measures have been taken to structure the European Higher Education Area (EHEA) (Bergen, 2005), such as the definition of the European Credit Transfer and Accumulation System (ECTS), with the adoption of a single system of degrees, with the (suggestion of) adoption of the Anglo-Saxon model, in the modality 3 + 2 years, in other words 180 + 120 ects, in the first two cycles, and the implementation of a quality assurance and accreditation system, based on entities and procedures that are coordinated nationally and transnationally (Antunes, 2008). We focus on the discussion of educational policy options for the training of teachers of children aged 3 to 12 years in Portugal, assessing the degree of autonomy in the ways of achieving the process of Europeanisation by the evolution of solutions implemented at the level of conditions of access, objectives and structure of the training - duration, fields and weights of the areas of specific knowledge of teachers, psycho-pedagogical knowledge and educational practice - within the scope of the 1st and 2nd cycle training offer. To this end, in addition to the bibliographic review considered relevant, we engaged in the documentary analysis of a broad range of sources among the documents originating from international and supranational institutions, working groups and intergovernmental platforms - studies, reports, surveys and their results, programs, projects, treaties, etc. - as well as of the legislative production on this matter by the last Portuguese governments, in order to clarify education policy principles and options in the field of teacher education, including recruitment, professional profile and the organisation of study plans and educational offer. In global terms, the process of Europeanisation has contributed to a certain convergence of educational policies, with an impact on Portuguese higher education and at the level of initial teacher training. The political changes generated variations in the legal regimes of initial training of educators and teachers illustrating the permanence of the State as a regulator at the national level and as a counterpoint to a transnational regulation of education. A perspective of the teacher as an autonomous professional with a critical attitude, capable of evaluating his/her work, who investigates and constructively reflects his/her professional knowledge, seems to give way to a more technical view of the teacher's work, oriented towards and for results. Teacher training presents a two-stage structure, but with undeniable integration of the training dimensions, with the Portuguese tradition of structural models still prevailing to the detriment of the conceptual ones (Ferreira e Mota, 2013). Since November 2015, the political context in Portugal has changed and several education measures have been reversed. However, teacher training remains unchanged. KEYWORDS: Bologna Process; European Higher Education Area; Teacher training RÉSUMÉ La modification du cadre juridique de la formation des enseignants et des éducateurs est advenue dans un contexte de développement de dynamiques de globalisation hégémonique (Santos, 2001). Dans ce contexte, l’Etat-nation a perdu de sa centralité, faisant émerger des entités économico-politiques régionales de nature supranationale dans une tentative, de la part des états, d’élargissement de leur influence dans les dynamiques de globalisation (Jessop, 2005). L’Union Européenne, forme avancée d’«Etat en réseau» (Castells, 2007), se présente en tant que configuration institutionnelle la plus développée et a affirmé progressivement un rôle croissant au niveau des politiques sociales, notamment l’éducation (Moutsios, 2009). Dans le processus de transnationalisation de l’éducation, certaines organisations internationales et supranationales ont gagné une croissante notoriété, par exemple, l’Organisation Mondiale du Commerce (OMC) ou l’Organisation pour la Coopération et le Développement Economique (OCDE). Dans ce contexte, on peut mettre en exergue l’Union Européenne (UE), dont le mandat contient des fonctions de régulation. Au sein de l’UE, les programmes d’éducation et de formation incluent les initiatives dans le contexte de la plateforme intergouvernementale Processus de Bologne (Conseil de l’Union Européenne, 2009a). Dans ce contexte aussi, ont été adoptées des mesures considérées cruciales afin de structurer l’Espace Européen de l’Enseignement Supérieur (EEES) (Bergen, 2005), comme la définition du Système Européen d’Accumulation et de Transfert de Crédits (ECTS), accompagnée de l’adoption d’un système unique de degrés, avec l’ (suggestion de) adoption du modèle anglo-saxon, dans la modalité 3 + 2 ans, c’est-à-dire 180 + 120 ects, lors des deux premiers cycles, et la mise en œuvre d’un système d’évaluation qui assure la qualité et l’accréditation, sur la base d’entités et de procédures qui se veulent articulées au niveau national e transnational (Antunes, 2008). Nous nous centrons sur la discussion des options de la politique éducative pour la formation des enseignants d’enfants de 3 à 12 ans d’âge, au Portugal, conférant le degré d’autonomie dans les voies d’exécution du processus d’européisation à travers l’évolution des solutions mises en œuvre au niveau des conditions d’accès, des objectifs et de la structure de la formation – durée, volets et poids des domaines du savoir spécifique des enseignants, du savoir psychopédagogique et de la pratique éducative – dans le cadre de l’offre formative du 1er et du 2d cycles. À cet effet, outre la révision bibliographique considérée pertinente, nous procédons à l’analyse documentaire d’un ensemble diversifié de sources parmi les documents émanant des institutions internationales et supranationales, de groupes de travail et de plateformes intergouvernementales – études, rapports, enquêtes et leurs résultats, programmes, projets, traités, etc. –, ainsi que la production législative sur la problématique, des derniers gouvernements du Portugal, dans le but de clarifier des principes et des options de politique éducative dans le domaine de la formation d’enseignants, surtout au niveau du recrutement, du profil professionnel et de l’organisation des plans d’étude et de l’offre éducative. Globalement, le processus d’européisation a contribué à une certaine convergence des politiques éducatives, avec un impact dans l’enseignement supérieur portugais et au niveau de la formation initiale d’enseignants. Les modifications politiques ont engendré des changements dans les régimes juridiques de formation initiale d’éducateurs et d’enseignants démontrant bien la permanence de l’Etat en tant que régulateur, sur le plan national, comme contrepoids à une régulation transnationale de l’éducation. Une perspective de l’enseignant en tant que professionnel doté d’une attitude critique, capable d’évaluer son action, qui recherche et construit de façon réfléchie son savoir professionnel, semble glisser vers une vision plus technique du travail d’enseignant, orienté par et vers ses résultats. La formation présente une structure en deux étapes, mais avec une indéniable intégration des dimensions de formation; cependant, ce qui prévaut c’est la tradition portugaise de modèles structuraux au détriment des modèles conceptuels (Ferreira e Mota, 2013). Depuis novembre 2015 que le contexte politique, au Portugal, s’est modifié et, dans l’éducation, différentes mesures ont été inversées. Toutefois, la formation d’enseignants est maintenue inchangée. MOTS-CLÉS: Processus de Bologne; Espace européen de l’enseignement supérieur; Formation des enseignants.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Ahsan, Muhammad Sheraz, Ejaz Hussain, Christiaan Lemmen, Malumbo Chaka Chipofya, Jaap Zevenbergen, Salman Atif, Javier Morales, Mila Koeva et Zahir Ali. « Applying the Land Administration Domain Model (LADM) for Integrated, Standardized, and Sustainable Development of Cadastre Country Profile for Pakistan ». Land 13, n^o 6 (18 juin 2024) : 883. http://dx.doi.org/10.3390/land13060883.

Texte intégral

Résumé :

Rapid urban growth necessitates focused attention regarding its policy and governance to ensure affordable housing, transparent and efficient real-world systems, reduce social inequalities, and promote sustainable development. This study delves into the semantics and ontology for developing a Land Administration Domain Model (LADM) profile in the context of Pakistan’s Land Administration Systems (LASs), which currently face issues due to manual record-keeping, lack of transparency, frauds, and disintegration. Establishing a baseline through Record of Rights (RoR) and Property Information Report (PIR), alongside surveying and mapping procedures defined by laws and rules, forms the foundation for LADM profile development. This study explores the transition from manual LAS to 2D/3D representation, using LADM as a conceptual guideline. The LADM profile’s three key packages—PK_Party, PK_Administrative, and PK_SpatialUnit—a sub-package, and external classes are examined, with proposals for digitalisation and modernisation. Additionally, the study includes expert consultation, and highlights the significant support that the LADM implementation offers to achieve Sustainable Development Goals (SDGs) in Pakistan. In conclusion, the study underscores the need for a comprehensive and inclusive approach to address organisational overlaps and ambiguities within LAS, positioning PK LADM as a transformative force for sustainable urban LAS in Pakistan, aligning with broader SDGs. Recommendations include exploring realistic land valuation, integrated ownership and location verification systems, addressing historical survey data challenges, and promoting wider stakeholder adoption for sustainable 2D/3D urban LAS using LADM and its edition II as a way forward towards the creation of a smart city and digital twin.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Kalogianni, Eftychia, Peter van Oosterom, Efi Dimopoulou et Christiaan Lemmen. « 3D Land Administration : A Review and a Future Vision in the Context of the Spatial Development Lifecycle ». ISPRS International Journal of Geo-Information 9, n^o 2 (13 février 2020) : 107. http://dx.doi.org/10.3390/ijgi9020107.

Texte intégral

Résumé :

Land Administration practices worldwide rely mainly on 2D-based systems to define legal and other spatial boundaries related to land interests. However, the built environment is increasingly becoming spatially complex. Land administrators are challenged by an unprecedented demand to utilise space above and below earth’s surface. The relationships between people and land in vertical space can no longer be unambiguously represented in 2D. In addition, the current societal demand for sustainability in a collaborative environment and a lifecycle-thinking, is driving the need to integrate independent systems with standalone databases and methodologies, associated with different aspects of the Spatial Development lifeCycle (SDC). Land Administration Systems (LASs) are an important component of the SDC. Today, a LAS is often mandated and managed as a domain in isolation. Interaction and data reuse with the other phases of the SDC is limited and far from optimal. It is expected that effective 3D data collaboration, sharing, and reuse across the sectors and disciplines in the lifecycle will enable new ways of data harmonisation and use in this complex environment; will improve efficiency of design and data acquisition, as well as data quality (in relation to specific regulations); and will minimise inconsistencies and data loss within information flows. Overall, a cross-sectoral approach is directed towards improving the current state of the Land Administration (LA) domain. This paper consists of two parts. In the first, a review of the current situation, with respect to LASs is presented, concluding the needs for improvement in terms of effectiveness and consistency. In the second part, the vision for the future of LASs is introduced in a wider context, and as an important phase in the SDC, with regards to legal, technical, and organisational aspects. In this part, the needs and considerations that result from the evolving environment and the emerging technological advances are addressed, with a view to discussing a cross-sector approach to collect, maintain, reuse, and share 3D data. In such a cross-sectoral approach, various interoperability issues appear, making it necessary to introduce and use standards. In this respect, the ISO 19152:2012 Land Administration Domain Model (LADM) in its current Edition I, as well as in Edition II (expected in 2022) may serve as the standardised core structure of a 3D LAS, with respect to its role as further presented in this paper. In parallel, the evolution of the Building Information Modelling (BIM) in the design and construction industry, as well as the fact that BIM plays a central role in the life cycle of development projects, are well recognized. Emphasis is given on feasible reuse of BIM/IFC (Industry Foundation Class) data in a 3D LAS. Those considerations are addressed through a web-based system architecture for a future 3D LAS, thereby attempting to integrate heterogeneous systems in the SDC.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Phillips, Thomas A., Stefania Marcotti, Susan Cox et Maddy Parsons. « Imaging actin organisation and dynamics in 3D ». Journal of Cell Science 137, n^o 2 (15 janvier 2024). http://dx.doi.org/10.1242/jcs.261389.

Texte intégral

Résumé :

ABSTRACT The actin cytoskeleton plays a critical role in cell architecture and the control of fundamental processes including cell division, migration and survival. The dynamics and organisation of F-actin have been widely studied in a breadth of cell types on classical two-dimensional (2D) surfaces. Recent advances in optical microscopy have enabled interrogation of these cytoskeletal networks in cells within three-dimensional (3D) scaffolds, tissues and in vivo. Emerging studies indicate that the dimensionality experienced by cells has a profound impact on the structure and function of the cytoskeleton, with cells in 3D environments exhibiting cytoskeletal arrangements that differ to cells in 2D environments. However, the addition of a third (and fourth, with time) dimension leads to challenges in sample preparation, imaging and analysis, necessitating additional considerations to achieve the required signal-to-noise ratio and spatial and temporal resolution. Here, we summarise the current tools for imaging actin in a 3D context and highlight examples of the importance of this in understanding cytoskeletal biology and the challenges and opportunities in this domain.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Jeffries, Gavin D. M., Shijun Xu, Tatsiana Lobovkina, Vladimir Kirejev, Florian Tusseau, Christoffer Gyllensten, Avadhesh Kumar Singh, Paul Karila, Lydia Moll et Owe Orwar. « 3D micro-organisation printing of mammalian cells to generate biological tissues ». Scientific Reports 10, n^o 1 (10 novembre 2020). http://dx.doi.org/10.1038/s41598-020-74191-w.

Texte intégral

Résumé :

Abstract Significant strides have been made in the development of in vitro systems for disease modelling. However, the requirement of microenvironment control has placed limitations on the generation of relevant models. Herein, we present a biological tissue printing approach that employs open-volume microfluidics to position individual cells in complex 2D and 3D patterns, as well as in single cell arrays. The variety of bioprinted cell types employed, including skin epithelial (HaCaT), skin cancer (A431), liver cancer (Hep G2), and fibroblast (3T3-J2) cells, all of which exhibited excellent viability and survivability, allowing printed structures to rapidly develop into confluent tissues. To demonstrate a simple 2D oncology model, A431 and HaCaT cells were printed and grown into tissues. Furthermore, a basic skin model was established to probe drug response. 3D tissue formation was demonstrated by co-printing Hep G2 and 3T3-J2 cells onto an established fibroblast layer, the functionality of which was probed by measuring albumin production, and was found to be higher in comparison to both 2D and monoculture approaches. Bioprinting of primary cells was tested using acutely isolated primary rat dorsal root ganglia neurons, which survived and established processes. The presented technique offers a novel open-volume microfluidics approach to bioprint cells for the generation of biological tissues.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Windels, Sam F. L., Daniel Tello Velasco, Mikhail Rotkevich, Noël Malod-Dognin et Nataša Pržulj. « Graphlet-based hyperbolic embeddings capture evolutionary dynamics in genetic networks ». Bioinformatics, 4 novembre 2024. http://dx.doi.org/10.1093/bioinformatics/btae650.

Texte intégral

Résumé :

Abstract Motivation Spatial Analysis of Functional Enrichment (SAFE) is a popular tool for biologists to investigate the functional organisation of biological networks via highly intuitive 2D functional maps. To create these maps, SAFE uses Spring embedding to project a given network into a 2D space in which nodes connected in the network are near each other in space. However, many biological networks are scale-free, containing highly connected hub nodes. Because Spring embedding fails to separate hub nodes, it provides uninformative embeddings that resemble a “hairball”. In addition, Spring embedding only captures direct node connectivity in the network and does not consider higher-order node wiring patterns, which are best captured by graphlets, small, connected, non-isomorphic, induced subgraphs. The scale-free structure of biological networks is hypothesised to stem from an underlying low-dimensional hyperbolic geometry, which novel hyperbolic embedding methods try to uncover. These include coalescent embedding, which projects a network onto a 2D disk. Results To better capture the functional organisation of scale-free biological networks, whilst also going beyond simple direct connectivity patterns, we introduce Graphlet Coalescent (GraCoal) embedding, which embeds nodes nearby on a disk if they frequently co-occur on a given graphlet together. We use GraCoal to extend SAFE-based network analysis. Through SAFE-enabled enrichment analysis, we show that GraCoal outperforms graphlet-based Spring embedding in capturing the functional organisation of the genetic interaction networks of fruit fly, budding yeast, fission yeast and E. coli. We show that depending on the underlying graphlet, GraCoal embeddings capture different topology-function relationships. We show that triangle-based GraCoal embedding captures functional redundancies between paralogs. Availability https://gitlab.bsc.es/swindels/gracoal_embedding Supplementary information Supplementary data are available at Bioinformatics online.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Lee, Sun Young, Sung Bum Park, Young Eun Kim, Hee Min Yoo, Jongki Hong, Kyoung-Jin Choi, Ki Young Kim et Dukjin Kang. « iTRAQ-Based Quantitative Proteomic Comparison of 2D and 3D Adipocyte Cell Models Co-cultured with Macrophages Using Online 2D-nanoLC-ESI-MS/MS ». Scientific Reports 9, n^o 1 (14 novembre 2019). http://dx.doi.org/10.1038/s41598-019-53196-0.

Texte intégral

Résumé :

AbstractThe demand for novel three-dimensional (3D) cell culture models of adipose tissue has been increasing, and proteomic investigations are important for determining the underlying causes of obesity, type II diabetes, and metabolic disorders. In this study, we performed global quantitative proteomic profiling of three 3D-cultured 3T3-L1 cells (preadipocytes, adipocytes and co-cultured adipocytes with macrophages) and their 2D-cultured counterparts using 2D-nanoLC-ESI-MS/MS with iTRAQ labelling. A total of 2,885 shared proteins from six types of adipose cells were identified and quantified in four replicates. Among them, 48 proteins involved in carbohydrate metabolism (e.g., PDHα, MDH1/2, FH) and the mitochondrial fatty acid beta oxidation pathway (e.g., VLCAD, ACADM, ECHDC1, ALDH6A1) were relatively up-regulated in the 3D co-culture model compared to those in 2D and 3D mono-cultured cells. Conversely, 12 proteins implicated in cellular component organisation (e.g., ANXA1, ANXA2) and the cell cycle (e.g., MCM family proteins) were down-regulated. These quantitative assessments showed that the 3D co-culture system of adipocytes and macrophages led to the development of insulin resistance, thereby providing a promising in vitro obesity model that is more equivalent to the in vivo conditions with respect to the mechanisms underpinning metabolic syndromes and the effect of new medical treatments for metabolic disorders.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Sanchez, Clément, Eduardo L. Crepaldi, Anne Bouchara, Florence Cagnol, David Grosso et Galo J. de A. A. Soler-Illia. « Design of Transition Metal Oxide and Hybrid Mesoporous Materials ». MRS Proceedings 728 (2002). http://dx.doi.org/10.1557/proc-728-s1.2.

Texte intégral

Résumé :

AbstractMesostructured transition metal (Ti, Zr, V, Al and Ce-Zr) oxide-based hybrid thin films, templated by poly(ethylene oxide)-based surfactants or block copolymers, have been prepared reproducibly, displaying 2D-hexagonal (p6m) or 2D-centred rectangular (c2m) structure. By carefully adjusting the variables involved it is possible to combine both high organisation and excellent optical quality. TiO2 and ZrO2-based materials show thermal stability up to 400-550°C. The elimination of the template can be conducted efficiently and gives rise to high surface area mesoporous films. For the other metal oxide hybrids the inorganic framework is much more fragile, and requires a precise sequence of post-treatments to be stabilised. In addition, original and homogeneous macrotextures shaped with coral-like, helical or macroporous sieves morphologies have been obtained following a nanotectonic approach based on the template-directed assembly by poly-γ-benzyl-L-glutamate (PBLG) of organically functionalised CeO2 crystalline nanoparticles.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Hrishikesh, Bhadra, Kyohei Takae, Ethayaraja Mani et Hajime Tanaka. « Phase separation of rotor mixtures without domain coarsening driven by two-dimensional turbulence ». Communications Physics 5, n^o 1 (27 décembre 2022). http://dx.doi.org/10.1038/s42005-022-01116-6.

Texte intégral

Résumé :

AbstractUnlike in thermodynamic systems, phase separation can occur without a thermodynamic driving force in active systems. How phase separation of purely hydrodynamic origin proceeds is an intriguing physical question. To this end, we study the phase separation of a binary mixture of oppositely rotating disks in a two-dimensional (2D) viscous fluid at an athermal condition by hydrodynamic simulations, focusing on the inertia effect. At symmetric and off-symmetric compositions, phase separation forms the oppositely flowing bands and a circular rotating droplet in the disordered matrix phase. In both cases, phase separation creates the largest structure directly from a chaotic state without gradual domain coarsening, unlike in the thermodynamic and corresponding dry rotor mixtures. We show that this unusual behaviour results from the nonlinear convective acceleration, i.e., the inverse cascade phenomena characteristic of 2D turbulence. Our finding reveals nontrivial nonlinear hydrodynamic effects on the self-organisation of active/driven particles in a fluid.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Vernon, Alexander R., Roy M. Pemberton et H. Ruth Morse. « A novel in vitro 3D model of the human bone marrow to bridge the gap between in vitro and in vivo genotoxicity testing ». Mutagenesis, 8 avril 2022. http://dx.doi.org/10.1093/mutage/geac009.

Texte intégral

Résumé :

Abstract The regulatory 2D in vitro micronucleus (MN) assay is part of a battery of tests, used to test for genotoxicity of new and existing compounds before they are assessed in vivo (ICH S2). The 2D MN assay consists of a monolayer of cells, whereas the in vivo bone marrow (BM) setting comprises a multicellular environment within a three-dimensional extracellular matrix. Although the in vitro MN assay follows a robust protocol set out by the Organisation for Economic Co-operation and Development (OECD) to comply with regulatory bodies, some compounds have been identified as negative genotoxicants within the in vitro MN assay but marginally positive when assessed in vivo. The glucocorticoids, which are weakly positive in vivo, have generally been suggested to pose no long-term carcinogenic risk; however, for novel compounds of unknown activity, improved prediction of genotoxicity is imperative. To help address this observation, we describe a novel 3D in vitro assay which aims to replicate the results seen within the in vivo BM microenvironment. AlgiMatrix scaffolds were optimized for seeding with HS-5 human BM stromal cells as a BM microenvironment, to which the human lymphoblast cell line TK6 was added. An MN assay was performed aligning with the 2D regulatory assay protocol. Utilizing this novel 3D in vitro model of the BM, known genotoxicants (mitomycin C, etoposide, and paclitaxel), a negative control (caffeine), and in vivo positive glucocorticoids (dexamethasone and prednisolone) were investigated for the induction of MN. It was found, in agreement with historical in vivo data, that the model could accurately predict the in vivo outcome of the glucocorticoids, unlike the regulatory 2D in vitro MN assay. These preliminary results suggest our 3D MN assay may better predict the outcome of in vivo MN tests, compared with the standard 2D assay.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Roterman, Irena, Katarzyna Stapor, Dawid Dułak et Leszek Konieczny. « Secondary structure in polymorphic forms of alpha-synuclein amyloids ». Acta Biochimica Polonica, 18 juin 2023. http://dx.doi.org/10.18388/abp.2020_6788.

Texte intégral

Résumé :

Numerous Alpha-synuclein amyloid structures available in PDB enable their comparative analysis. They are all characterized by a flat structure of each individual chain with an extensive network of inter-chain hydrogen bonds. The identification of such amyloid fibril structures requires determining the special conditions imposed on the torsion angles. Such conditions have already been formulated by the Authors resulting in the model of idealised amyloid. Here, we investigate the fit of this model in the group of A-Syn amyloid fibrils. We identify and describe the characteristic supersecondary structures in amyloids. Generally, the amyloid transformation is suggested to be the 3D to 2D transformation engaging mostly the loops linking Beta-structural fragments. The loop structure introducing the 3D organisation of Beta-sheet change to flat form (2D) introduces the mutual reorientation of Beta-strands enabling the large-scale H-bonds generation with the water molecules. Based on the model of idealised amyloid we postulate the hypothesis for amyloid fibril formation based on the shaking, an experimental procedure producing the amyloids.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Kim, Jisoo, Matias Kagias, Federica Marone, Zhitian Shi et Marco Stampanoni. « Fast acquisition protocol for X-ray scattering tensor tomography ». Scientific Reports 11, n^o 1 (29 novembre 2021). http://dx.doi.org/10.1038/s41598-021-02467-w.

Texte intégral

Résumé :

AbstractMicrostructural information over an entire sample is important to understand the macroscopic behaviour of materials. X-ray scattering tensor tomography facilitates the investigation of the microstructural organisation in statistically large sample volumes. However, established acquisition protocols based on scanning small-angle X-ray scattering and X-ray grating interferometry inherently require long scan times even with highly brilliant X-ray sources. Recent developments in X-ray diffractive optics towards circular pattern arrays enable fast single-shot acquisition of the sample scattering properties with 2D omnidirectional sensitivity. X-ray scattering tensor tomography with the use of this circular grating array has been demonstrated. We propose here simple yet inherently rapid acquisition protocols for X-ray scattering tensor tomography leveraging on these new optical elements. Results from both simulation and experimental data, supported by a null space analysis, suggest that the proposed acquisition protocols are not only rapid but also corroborate that sufficient information for the accurate volumetric reconstruction of the scattering properties is provided. The proposed acquisition protocols will build the basis for rapid inspection and/or time-resolved tensor tomography of the microstructural organisation over an extended field of view.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Svetlove, Angelika, Titus Griebel, Jonas Albers, Lorenzo D’Amico, Philipp Nolte, Giuliana Tromba, Hanibal Bohnenberger, Frauke Alves et Christian Dullin. « X-ray phase-contrast 3D virtual histology characterises complex tissue architecture in colorectal cancer ». Frontiers in Gastroenterology 2 (24 octobre 2023). http://dx.doi.org/10.3389/fgstr.2023.1283052.

Texte intégral

Résumé :

Precise morphological analysis of tumour tissue samples is crucial for accurate diagnosis and staging of colorectal cancer (CRC), but remains limited by the 2D nature of conventional histology. Our aim is to offer a 3D representation of tissue samples by means of X-ray-based imaging to facilitate the evaluation of clinically relevant features in cancer tissue, a process that is currently subject to various restrictions. In this study, we show that propagation-based synchrotron radiation-based free propagation phase-contrast microcomputed tomography (SRµCT) is suitable for the generation of 3D tumour volumes with 2-µm voxel size using standard formalin-fixed, paraffin-embedded tissue from CRC patients and provides sufficient contrast for virtual histology. We demonstrate that, using an existing registration pipeline, a 2D histologic haematoxylin–eosin slice can be placed in the context of the 3D µCT volume. The precisely registered histologic section can then be used as a “seed point” for the segmentation and depiction of major histologic features. This approach allows for a more comprehensive understanding of the organisation of the tumour in space with respect to other structures such as vessels, fat, and lymph nodes, and has the potential to improve patients’ prognostic outcomes.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Dreher, Maximilian, Pierre Martin Dombrowski, Matthias Wolfgang Tripp, Niels Münster, Ulrich Koert et Gregor Witte. « Shape control in 2D molecular nanosheets by tuning anisotropic intermolecular interactions and assembly kinetics ». Nature Communications 14, n^o 1 (21 mars 2023). http://dx.doi.org/10.1038/s41467-023-37203-7.

Texte intégral

Résumé :

AbstractSince molecular materials often decompose upon exposure to radiation, lithographic patterning techniques established for inorganic materials are usually not applicable for the fabrication of organic nanostructures. Instead, molecular self-organisation must be utilised to achieve bottom-up growth of desired structures. Here, we demonstrate control over the mesoscopic shape of 2D molecular nanosheets without affecting their nanoscopic molecular packing motif, using molecules that do not form lateral covalent bonds. We show that anisotropic attractive Coulomb forces between partially fluorinated pentacenes lead to the growth of distinctly elongated nanosheets and that the direction of elongation differs between nanosheets that were grown and ones that were fabricated by partial desorption of a complete molecular monolayer. Using kinetic Monte Carlo simulations, we show that lateral intermolecular interactions alone are sufficient to rationalise the different kinetics of structure formation during nanosheet growth and desorption, without inclusion of interactions between the molecules and the supporting MoS2 substrate. By comparison of the behaviour of differently fluorinated molecules, experimentally and computationally, we can identify properties of molecules with regard to interactions and molecular packing motifs that are required for an effective utilisation of the observed effect.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Zhou, Ying, Xiaoliang Wang, Yaping Shi, Haiyang Ding, Yanbo Hui, Ju Gao, Luyao Bai et Qiao Wang. « 3D reconstruction and morphological characterisation of single wheat grains by X‐ray μCT ». International Journal of Food Science & ; Technology, 5 octobre 2024. http://dx.doi.org/10.1111/ijfs.17500.

Texte intégral

Résumé :

SummaryThe intricate task of achieving three‐dimensional (3D) visual reconstruction of wheat kernels represents a notable challenge within the domain of digital grain analysis, playing a pivotal role in the realms of grain storage, processing, and breeding. However, existing investigations focused on individual kernels predominantly encompass dimensions such as length, width, height, and epidermal texture features, with a tendency to be invasive to the internal organisational structure of the kernel. Non‐local mean filtering algorithm is proposed to segment various tissues, and the 2D grey scale images are extracted from X‐ray micro‐computed tomography (μCT) to reconstruct a meticulous 3D visualisation model of individual wheat grains. Furthermore, building upon this foundation, an exhaustive assessment of morphological and structural parameters pertaining to each facet of the internal organisation of the wheat seed grain is conducted. Notably, these calculated parameters align with data generated by prior researchers，with 80% of the volume of the endosperm, 12% of the pericarp, about 2% of the endosperm and scutellum, and 4% of the pores. The established parameters and resultant 3D visual models serve as foundational components for subsequent in‐depth examinations into various physicochemical properties, including quality characteristics, heat, and mass transfer attributes, as well as variations in its morphological structure during breeding, which are pertinent to individual grains. This research contributes valuable insights and methodologies that can propel the advancement of studies in wheat kernel analysis.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Hailstone, Martin, Dominic Waithe, Tamsin J. Samuels, Lu Yang, Ita Costello, Yoav Arava, Elizabeth Robertson, Richard M. Parton et Ilan Davis. « CytoCensus, mapping cell identity and division in tissues and organs using machine learning ». eLife 9 (19 mai 2020). http://dx.doi.org/10.7554/elife.51085.

Texte intégral

Résumé :

A major challenge in cell and developmental biology is the automated identification and quantitation of cells in complex multilayered tissues. We developed CytoCensus: an easily deployed implementation of supervised machine learning that extends convenient 2D ‘point-and-click’ user training to 3D detection of cells in challenging datasets with ill-defined cell boundaries. In tests on such datasets, CytoCensus outperforms other freely available image analysis software in accuracy and speed of cell detection. We used CytoCensus to count stem cells and their progeny, and to quantify individual cell divisions from time-lapse movies of explanted Drosophila larval brains, comparing wild-type and mutant phenotypes. We further illustrate the general utility and future potential of CytoCensus by analysing the 3D organisation of multiple cell classes in Zebrafish retinal organoids and cell distributions in mouse embryos. CytoCensus opens the possibility of straightforward and robust automated analysis of developmental phenotypes in complex tissues.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Wadkin, L. E., I. Makarenko, N. G. Parker, A. Shukurov, F. C. Figueiredo et M. Lako. « Human Stem Cells for Ophthalmology : Recent Advances in Diagnostic Image Analysis and Computational Modelling ». Current Stem Cell Reports, 18 novembre 2023. http://dx.doi.org/10.1007/s40778-023-00229-0.

Texte intégral

Résumé :

Abstract Purpose of Review To explore the advances and future research directions in image analysis and computational modelling of human stem cells (hSCs) for ophthalmological applications. Recent Findings hSCs hold great potential in ocular regenerative medicine due to their application in cell-based therapies and in disease modelling and drug discovery using state-of-the-art 2D and 3D organoid models. However, a deeper characterisation of their complex, multi-scale properties is required to optimise their translation to clinical practice. Image analysis combined with computational modelling is a powerful tool to explore mechanisms of hSC behaviour and aid clinical diagnosis and therapy. Summary Many computational models draw on a variety of techniques, often blending continuum and discrete approaches, and have been used to describe cell differentiation and self-organisation. Machine learning tools are having a significant impact in model development and improving image classification processes for clinical diagnosis and treatment and will be the focus of much future research.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Turnbull, C., A. Macleod, S. Esposito, R. Gorantla, S. Seth, R. Ramamoorthy et F. Mehendale. « 616 Addressing Challenges to Enable Better Use of Routinely Collected Clinical Photographs : Evaluating the Largest Cleft Dataset for Machine Learning Analysis ». British Journal of Surgery 109, Supplement_6 (19 août 2022). http://dx.doi.org/10.1093/bjs/znac269.310.

Texte intégral

Résumé :

Abstract Aim Orofacial clefts are the most common congenital anomaly to affect the craniofacial region. Surgical repair is usually performed in infancy; however, there are concerning inequalities in access to and quality of surgical care. Scoring aesthetic results after surgery is crucial when determining the success of a repair. A reliable and accurate scoring system utilising large numbers of unstandardised 2-dimentional (2D) photographs of ethnically diverse patients, which is inexpensive, widely accepted and easily applicable, does not exist. Artificial Intelligence (AI) has been applied in various surgical specialities with beneficial results; however, its advantages have not yet been harnessed in cleft care. We aimed to evaluate the potential use of routinely collected 2D photographs of patients with an orofacial cleft and determine if non-standardised data could be used for machine learning (ML) analysis in cleft research. Method A database comprising over 5 million photographs, collected over 20 years, and developed by the international non-governmental organisation Smile Train, was described, and analysed using RStudio and Microsoft Excel. Results Description and analysis of the dataset demonstrated that it is the largest and most ethnically inclusive and diverse dataset that currently exists. Preliminary AI analysis confirmed that ML could be used to analyse the data. Conclusion The quality of routinely collected data presents challenges for use in research. Addressing such challenges helps ensure that findings are more representative of global burden of disease and will deliver outcomes that are more relevant to a diverse global population. Evidence based minimum standards to optimise future data collection have been identified.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Garcia-Canadilla, Patricia, Timothy J. Mohun, Bart Bijnens et Andrew C. Cook. « Detailed quantification of cardiac ventricular myocardial architecture in the embryonic and fetal mouse heart by application of structure tensor analysis to high resolution episcopic microscopic data ». Frontiers in Cell and Developmental Biology 10 (16 novembre 2022). http://dx.doi.org/10.3389/fcell.2022.1000684.

Texte intégral

Résumé :

The mammalian heart, which is one of the first organs to form and function during embryogenesis, develops from a simple tube into a complex organ able to efficiently pump blood towards the rest of the body. The progressive growth of the compact myocardium during embryonic development is accompanied by changes in its structural complexity and organisation. However, how myocardial myoarchitecture develops during embryogenesis remain poorly understood. To date, analysis of heart development has focused mainly on qualitative descriptions using selected 2D histological sections. High resolution episcopic microscopy (HREM) is a novel microscopic imaging technique that enables to obtain high-resolution three-dimensional images of the heart and perform detailed quantitative analyses of heart development. In this work, we performed a detailed characterization of the development of myocardial architecture in wildtype mice, from E14.5 to E18.5, by means of structure tensor analysis applied to HREM images of the heart. Our results shows that even at E14.5, myocytes are already aligned, showing a gradual change in their helical angle from positive angulation in the endocardium towards negative angulation in the epicardium. Moreover, there is gradual increase in the degree of myocardial organisation concomitant with myocardial growth. However, the development of the myoarchitecture is heterogeneous showing regional differences between ventricles, ventricular walls as well as between myocardial layers, with different growth patterning between the endocardium and epicardium. We also found that the percentage of circumferentially arranged myocytes within the LV significantly increases with gestational age. Finally, we found that fractional anisotropy (FA) within the LV gradually increases with gestational age, while the FA within RV remains unchanged.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Todorovski, Vanja, Finn McCluggage, Yixuan Li, Annika Meid, Joachim P. Spatz, Andrew W. Holle, Archa H. Fox et Yu Suk Choi. « Confined environments induce polarized paraspeckle condensates ». Communications Biology 6, n^o 1 (3 février 2023). http://dx.doi.org/10.1038/s42003-023-04528-4.

Texte intégral

Résumé :

AbstractCancer cells experience confinement as they navigate the tumour microenvironment during metastasis. Recent studies have revealed that the nucleus can function as a ‘ruler’ for measuring physical confinement via membrane tension, allowing for compression-sensitive changes in migration. Cell nuclei contain many nuclear bodies that form when their components phase separate and condense within permissive local regions within the nucleus. However, how sub-nuclear organisation and phase separation changes with cell confinement and compression is largely unknown. Here we focus on paraspeckles, stress-responsive subnuclear bodies that form by phase separation around the long non-coding RNA NEAT1. As cells entered moderate confinement, a significant increase in paraspeckle number and size was observed compared to unconfined cells. Paraspeckle polarization bias towards the leading edge was also observed in confinement, correlating with regions of euchromatin. Increasing paraspeckle abundance resulted in increases in confined migration likelihood, speed, and directionality, as well as an enhancement of paraspeckle polarization towards the leading edge. This polarization of paraspeckle condensates may play a key role in regulating confined migration and invasion in cancer cells, and illustrates the utility of microchannel-based assays for identifying phenomena not observed on 2D or 3D bulk substrates.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Lounas, Amel, Ariane Lebrun, Isabelle Laflamme, Nathalie Vernoux, Julie Savage, Marie-Ève Tremblay, Marc Germain et François J. Richard. « A 3D analysis revealed complexe mitochondria morphologies in porcine cumulus cells ». Scientific Reports 12, n^o 1 (13 septembre 2022). http://dx.doi.org/10.1038/s41598-022-19723-2.

Texte intégral

Résumé :

AbstractIn the ovarian follicle, a bilateral cell-to-cell communication exists between the female germ cell and the cumulus cells which surround the oocyte. This communication allows the transit of small size molecules known to impact oocyte developmental competence. Pyruvate derivatives produced by mitochondria, are one of these transferred molecules. Interestingly, mitochondria may adopt a variety of morphologies to regulate their functions. In this study, we described mitochondrial morphologies in porcine cumulus cells. Active mitochondria were stained with TMRM (Tetramethylrhodamine, Methyl Ester, Perchlorate) and observed with 2D confocal microscopy showing mitochondria of different morphologies such as short, intermediate, long, and very long. The number of mitochondria of each phenotype was quantified in cells and the results showed that most cells contained elongated mitochondria. Scanning electron microscopy (SEM) analysis confirmed at nanoscale resolution the different mitochondrial morphologies including round, short, intermediate, and long. Interestingly, 3D visualisation by focused ion-beam scanning electron microscopy (FIB-SEM) revealed different complex mitochondrial morphologies including connected clusters of different sizes, branched mitochondria, as well as individual mitochondria. Since mitochondrial dynamics is a key regulator of function, the description of the mitochondrial network organisation will allow to further study mitochondrial dynamics in cumulus cells in response to various conditions such as in vitro maturation.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Walczak, Paige A., Patricia Perez-Esteban, David C. Bassett et Eric James Hill. « Modelling the central nervous system : tissue engineering of the cellular microenvironment ». Emerging Topics in Life Sciences, 15 septembre 2021. http://dx.doi.org/10.1042/etls20210245.

Texte intégral

Résumé :

With the increasing prevalence of neurodegenerative diseases, improved models of the central nervous system (CNS) will improve our understanding of neurophysiology and pathogenesis, whilst enabling exploration of novel therapeutics. Studies of brain physiology have largely been carried out using in vivo models, ex vivo brain slices or primary cell culture from rodents. Whilst these models have provided great insight into complex interactions between brain cell types, key differences remain between human and rodent brains, such as degree of cortical complexity. Unfortunately, comparative models of human brain tissue are lacking. The development of induced Pluripotent Stem Cells (iPSCs) has accelerated advancement within the field of in vitro tissue modelling. However, despite generating accurate cellular representations of cortical development and disease, two-dimensional (2D) iPSC-derived cultures lack an entire dimension of environmental information on structure, migration, polarity, neuronal circuitry and spatiotemporal organisation of cells. As such, researchers look to tissue engineering in order to develop advanced biomaterials and culture systems capable of providing necessary cues for guiding cell fates, to construct in vitro model systems with increased biological relevance. This review highlights experimental methods for engineering of in vitro culture systems to recapitulate the complexity of the CNS with consideration given to previously unexploited biophysical cues within the cellular microenvironment.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Organisation 2D »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres