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Rehpenn, Andreas, Alexandra Walter e Golo Storch. "Molecular Editing of Flavins for Catalysis". Synthesis 53, n. 15 (22 marzo 2021): 2583–93. http://dx.doi.org/10.1055/a-1458-2419.
Testo completoAbstract (sommario):
AbstractThe diverse activity of flavoenzymes in organic transformations has fascinated researchers for a long time. However, when applied outside an enzyme environment, the isolated flavin cofactor only shows largely reduced activity. This highlights the importance of embedding the reactive isoalloxazine core of flavins in defined surroundings. The latter include crucial non-covalent interactions with amino acid side chains or backbone as well as controlled access to reactants such as molecular oxygen. Nevertheless, molecular flavins are increasingly applied in the organic laboratory as valuable organocatalysts. Chemical modification of the parent isoalloxazine structure is of particular interest in this context in order to achieve reactivity and selectivity in transformations, which are so far only known with flavoenzymes or even unprecedented. This review aims to give a systematic overview of the reported designed flavin catalysts and highlights the impact of each structural alteration. It is intended to serve as a source of information when comparing the performance of known catalysts, but also when designing new flavins. Over the last few decades, molecular flavin catalysis has emerged from proof-of-concept reactions to increasingly sophisticated transformations. This stimulates anticipating new flavin catalyst designs for solving contemporary challenges in organic synthesis.1 Introduction2 N1-Modification3 N3-Modification4 N5-Modification5 C6–C9-Modification6 N10-Modification7 Conclusion
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Alrazzaq Ismail, Muhammad Abdul. "MODIFICATION". Journal of Tikrit University for Humanities 29, n. 7, 1 (10 luglio 2022): 78–90. http://dx.doi.org/10.25130/jtuh.29.7.1.2022.24.
Testo completoAbstract (sommario):
This research paper investigates the main features and types of modification. This research paper is clear and easy to read by every student and anyone who wants to develop his knowledge, especially in the modification field. The following research includes an introduction of modification definitions of modification, kinds of modifications, positions of modification forms of modification premodification, and post modification and the conclusion that is gained from this research
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Kato, Yuki, Ken Muramatsu, Yoshinori Yamamoto, Yoshie Suzuki e Ryo Momosaki. "Strategies for Effective Home Modification in Older Adults". Geriatric Orthopaedic Surgery & Rehabilitation 12 (1 gennaio 2021): 215145932110207. http://dx.doi.org/10.1177/21514593211020704.
Testo completoAbstract (sommario):
There are various barriers to home modifications to prevent falls among the older population. Several strategies may be necessary to overcome these barriers and implement effective home modifications. The need for home modification should be assessed, which requires a home evaluation by a specialist. In Japan, welfare housing environment coordinators have been trained to provide advice on home modifications suitable for people with disabilities. In addition, in Japan, home assessment and advice on home modification before discharge from acute care hospitals for older people is allowed as a medical reimbursement, and a system for effective home modification is well established. Human resource training and medical policy arrangements on home modifications could improve the cost-effectiveness. In Japan, a system has been established to support the costs of home modification and environmental maintenance. Financial support has reduced the barrier to home modification. Fixed grab bars or shower chairs can be rented, which may be more cost-effective than purchasing them and may shorten the time required for installation. There may be psychological barriers to home modification for older population. Since many older people do not recognize the importance of home modification, promotion to convey the value of home modification may be necessary. Training of staff to engage in home modification, public financial support for modification, and ideas for reducing psychological hesitation may help to reduce the barriers for home modification and to enable effective home modification.
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Eichler, Jerry, e Michael W. W. Adams. "Posttranslational Protein Modification in Archaea". Microbiology and Molecular Biology Reviews 69, n. 3 (settembre 2005): 393–425. http://dx.doi.org/10.1128/mmbr.69.3.393-425.2005.
Testo completoAbstract (sommario):
SUMMARY One of the first hurdles to be negotiated in the postgenomic era involves the description of the entire protein content of the cell, the proteome. Such efforts are presently complicated by the various posttranslational modifications that proteins can experience, including glycosylation, lipid attachment, phosphorylation, methylation, disulfide bond formation, and proteolytic cleavage. Whereas these and other posttranslational protein modifications have been well characterized in Eucarya and Bacteria, posttranslational modification in Archaea has received far less attention. Although archaeal proteins can undergo posttranslational modifications reminiscent of what their eucaryal and bacterial counterparts experience, examination of archaeal posttranslational modification often reveals aspects not previously observed in the other two domains of life. In some cases, posttranslational modification allows a protein to survive the extreme conditions often encountered by Archaea. The various posttranslational modifications experienced by archaeal proteins, the molecular steps leading to these modifications, and the role played by posttranslational modification in Archaea form the focus of this review.
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Kim, Jiseob. "HOW LOAN MODIFICATIONS INFLUENCE THE PREVALENCE OF MORTGAGE DEFAULTS". Macroeconomic Dynamics 21, n. 1 (20 giugno 2016): 55–105. http://dx.doi.org/10.1017/s1365100515000395.
Testo completoAbstract (sommario):
How much can government-driven mortgage modification programs reduce the mortgage default rate? I compare an economy without a modification option to one with easy modifications, and evaluate the impact of these loan modifications on the foreclosure rate. Through loan modification, mortgage servicers can mitigate their losses and households can improve their financial positions without having to walk away from their homes. When modifying loan contracts is prohibitively costly, the default rate increases 1.5 percentage points in response to a 2007-style unexpected drop in housing prices of 30%. I calibrate the cost of modification after the financial crisis to match the Home Affordable Modification Program (HAMP) modification rate of 0.68%. My quantitative exercises show that current government efforts to promote mortgage modifications reduce the mortgage default rate by 0.63 percentage points.
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Liu, Qi, e Richard I. Gregory. "RNAmod: an integrated system for the annotation of mRNA modifications". Nucleic Acids Research 47, W1 (31 maggio 2019): W548—W555. http://dx.doi.org/10.1093/nar/gkz479.
Testo completoAbstract (sommario):
Abstract Dynamic and reversible RNA modifications such as N6-methyladenosine (m6A) can play important roles in regulating messenger RNA (mRNA) splicing, export, stability and translation. Defective mRNA modification through altered expression of the methyltransferase and/or demethylases results in developmental defects and cancer progression. Identifying modified mRNAs, annotating the distribution of modification sites across the mRNA, as well as characterizing and comparing other modification features are essential for studying the function and elucidating the mechanism of mRNA modifications. Several methods including methylated RNA immunoprecipitation and sequencing (MeRIP-seq) are available for the detection of mRNA modifications. However, a convenient and comprehensive tool to annotate diverse kinds of mRNA modifications in different species is lacking. Here, we developed RNAmod (https://bioinformatics.sc.cn/RNAmod), an interactive, one-stop, web-based platform for the automated analysis, annotation, and visualization of mRNA modifications in 21 species. RNAmod provides intuitive interfaces to show outputs including the distribution of RNA modifications, modification coverage for different gene features, functional annotation of modified mRNAs, and comparisons between different groups or specific gene sets. Furthermore, sites of known RNA modification, as well as binding site data for hundreds of RNA-binding proteins (RBPs) are integrated in RNAmod to help users compare their modification data with known modifications and to explore the relationship with the binding sites of known RBPs. RNAmod is freely available and meets the emerging need for a convenient and comprehensive analysis tool for the fast-developing RNA modification field.
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Zhang, Xiao-Xuan, Yu-Zhe Sun, Wei Wang, Yang Gao, Xin-Yu Wei, Hong-Chao Sun, Chun-Ren Wang et al. "Altered landscape of total RNA, tRNA and sncRNA modifications in the liver and spleen of mice infected by Toxoplasma gondii". PLOS Neglected Tropical Diseases 18, n. 6 (21 giugno 2024): e0012281. http://dx.doi.org/10.1371/journal.pntd.0012281.
Testo completoAbstract (sommario):
Background Pathogens can impact host RNA modification machinery to establish a favorable cellular environment for their replication. In the present study, we investigated the effect of Toxoplasma gondii infection on host RNA modification profiles and explored how these modifications may influence the host-parasite interaction. Methodology/principal findings We analyzed the modification levels of ∼ 80 nt tRNA and 17–50 nt sncRNAs in mouse liver, spleen, and serum using liquid chromatography and tandem mass spectrometry analysis. The results revealed alterations in RNA modification profiles, particularly during acute infection. The liver exhibited more differentially abundant RNA modifications than the spleen. RNA modification levels in serum were mostly downregulated during acute infection compared to control mice. Correlations were detected between different RNA modifications in the liver and spleen during infection and between several RNA modifications and many cytokines. Alterations in RNA modifications affected tRNA stability and protein translation. Conclusions/significance These findings provide new insight into the role of RNA modifications in mediating the murine host response to T. gondii infection.
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Winter, Stefan, e Wolfgang Fischle. "Epigenetic markers and their cross-talk". Essays in Biochemistry 48 (20 settembre 2010): 45–61. http://dx.doi.org/10.1042/bse0480045.
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Post-translational modifications of histone proteins in conjunction with DNA methylation represent important events in the regulation of local and global genome functions. Advances in the study of these chromatin modifications established temporal and spatial co-localization of several distinct ‘marks’ on the same histone and/or the same nucleosome. Such complex modification patterns suggest the possibility of combinatorial effects. This idea was originally proposed to establish a code of histone modifications that regulates the interpretation of the genetic code of DNA. Indeed, interdependency of different modifications is now well documented in the literature. Our current understanding is that the function of a given histone modification is influenced by neighbouring or additional modifications. Such context sensitivity of the readout of a modification provides more flexible translation than would be possible if distinct modifications function as isolated units. The mechanistic principles for modification cross-talk can originate in the modulation of the activity of histone-modifying enzymes or may be due to selective recognition of these marks via modification of specific binding proteins. In the present chapter, we discuss fundamental biochemical principles of modification cross-talk and reflect on the interplay of chromatin marks in cellular signalling, cell-cycle progression and cell-fate determination.
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Zhu, Sucheng, Tao Zheng, Lingxin Kong, Jinli Li, Bo Cao, Michael S. DeMott, Yihua Sun et al. "Development of Methods Derived from Iodine-Induced Specific Cleavage for Identification and Quantitation of DNA Phosphorothioate Modifications". Biomolecules 10, n. 11 (28 ottobre 2020): 1491. http://dx.doi.org/10.3390/biom10111491.
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DNA phosphorothioate (PT) modification is a novel modification that occurs on the DNA backbone, which refers to a non-bridging phosphate oxygen replaced by sulfur. This exclusive DNA modification widely distributes in bacteria but has not been found in eukaryotes to date. PT modification renders DNA nuclease tolerance and serves as a constitute element of bacterial restriction–modification (R–M) defensive system and more biological functions are awaiting exploration. Identification and quantification of the bacterial PT modifications are thus critical to better understanding their biological functions. This work describes three detailed methods derived from iodine-induced specific cleavage-an iodine-induced cleavage assay (ICA), a deep sequencing of iodine-induced cleavage at PT site (ICDS) and an iodine-induced cleavage PT sequencing (PT-IC-Seq)-for the investigation of PT modifications. Using these approaches, we have identified the presence of PT modifications and quantized the frequency of PT modifications in bacteria. These characterizations contributed to the high-resolution genomic mapping of PT modifications, in which the distribution of PT modification sites on the genome was marked accurately and the frequency of the specific modified sites was reliably obtained. Here, we provide time-saving and less labor-consuming methods for both of qualitative and quantitative analysis of genomic PT modifications. The application of these methodologies will offer great potential for better understanding the biology of the PT modifications and open the door to future further systematical study.
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Zhou, Ting, e Honghai Liu. "Research Progress of Wood Cell Wall Modification and Functional Improvement: A Review". Materials 15, n. 4 (21 febbraio 2022): 1598. http://dx.doi.org/10.3390/ma15041598.
Testo completoAbstract (sommario):
The modification of wood cell walls is based on the characteristics of the chemical composition and structure of the cell wall. Various physical and chemical modifications to these characteristics enhance the original properties of the cell wall and give additional functionality. Through complex modification, wood has also obtained the opportunity to become a multifunctional material. Scholars have paid more attention to the microscopic properties of the cell wall with continuous enrichment of modification methods and improvement of modification mechanisms. This article summarizes the methods of cell wall modification in recent years and proposes prospects for future development: (1) innovation of modifiers and combination with modification mechanism, as well as improvement of cell wall permeability; (2) the application directions of cell wall structures; and (3) the application of nano-technologies in cell wall modification. This review provides further ideas and technologies for wood modifications.
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Nazari, Simin, e Amira Abdelrasoul. "Impact of Membrane Modification and Surface Immobilization Techniques on the Hemocompatibility of Hemodialysis Membranes: A Critical Review". Membranes 12, n. 11 (28 ottobre 2022): 1063. http://dx.doi.org/10.3390/membranes12111063.
Testo completoAbstract (sommario):
Despite significant research efforts, hemodialysis patients have poor survival rates and low quality of life. Ultrafiltration (UF) membranes are the core of hemodialysis treatment, acting as a barrier for metabolic waste removal and supplying vital nutrients. So, developing a durable and suitable membrane that may be employed for therapeutic purposes is crucial. Surface modificationis a useful solution to boostmembrane characteristics like roughness, charge neutrality, wettability, hemocompatibility, and functionality, which are important in dialysis efficiency. The modification techniques can be classified as follows: (i) physical modification techniques (thermal treatment, polishing and grinding, blending, and coating), (ii) chemical modification (chemical methods, ozone treatment, ultraviolet-induced grafting, plasma treatment, high energy radiation, and enzymatic treatment); and (iii) combination methods (physicochemical). Despite the fact that each strategy has its own set of benefits and drawbacks, all of these methods yielded noteworthy outcomes, even if quantifying the enhanced performance is difficult. A hemodialysis membrane with outstanding hydrophilicity and hemocompatibility can be achieved by employing the right surface modification and immobilization technique. Modified membranes pave the way for more advancement in hemodialysis membrane hemocompatibility. Therefore, this critical review focused on the impact of the modification method used on the hemocompatibility of dialysis membranes while covering some possible modifications and basic research beyond clinical applications.
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Lin, Hsiang Hsi, Chinwai Lee, F. B. Oswald e D. P. Townsend. "Computer-Aided Design of High-Contact-Ratio Gears for Minimum Dynamic Load and Stress". Journal of Mechanical Design 115, n. 1 (1 marzo 1993): 171–78. http://dx.doi.org/10.1115/1.2919315.
Testo completoAbstract (sommario):
This paper presents a numerical procedure for minimizing dynamic effects on high-contact-ratio gears by modification of the tooth profile. The paper examines and compares both linear and parabolic tooth profile modifications of high-contact-ratio gears under various loading conditions. The effects of the total amount of modification and the length of the modification zone were systematically studied at various loads and speeds to find the optimum profile design for minimizing the dynamic load and the tooth bending stress. Parabolic profile modification is preferred over linear profile modification for high-contact-ratio gears because of its lower sensitivity to manufacturing errors. For parabolic modification a greater amount of modification at the tooth tip and a longer modification zone are required. Design charts are presented for high-contact-ratio gears with various profile modifications operating under a range of loads. A procedure is illustrated for using the charts to find the optimum profile design.
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Liu, Siyuan, Chaosheng Song, Caichao Zhu e Qi Fan. "Concave modifications of tooth surfaces of beveloid gears with crossed axes". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, n. 4 (4 aprile 2018): 1411–25. http://dx.doi.org/10.1177/0954406218768842.
Testo completoAbstract (sommario):
The mathematical models of the beveloid gear surfaces with different scenarios of combinations of profile concave modification and lead crowning are derived. Four schemes of modifications were proposed for beveloid gears with crossed axes. Tooth contact analysis is developed to study the influences of different schemes of concave modifications on the mesh behaviors including film thickness, transmission errors, contact ratio, root stresses, and contact patterns. Comparison of the contact characteristics of a beveloid gear drive with and without concave modifications is conducted. The results show that all the concave modification schemes can increase the area of contact patterns and decrease the maximum value of contact stresses, while the minimum film thickness can be increased. For the scheme i.e. the pinion with profile crowning modification and gear with profile concave modification, the contact ratio increases firstly then decreases to a relative lower value. Also, the root stresses are increased obviously. For the scheme for pinion without modification and gear with lead concave modification and the scheme for both pinion and gear with lead concave modification, the transmission errors are decreased slightly. The scheme for the pinion with combined crowning modification and gear with combined concave modification shows the largest improvement for the mesh behaviors in terms of the transmission errors and contact patterns where an almost contact condition can be found for the crossed beveloid gear pair.
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Lee, C. K., C. L. Hsieh, J. C. Ruan e C. Y. Wang. "Simulation of Meshing of Herringbone Double Circular-Arc Helical Gears using Multibody Dynamic Analysis Software". Journal of Physics: Conference Series 2287, n. 1 (1 giugno 2022): 012023. http://dx.doi.org/10.1088/1742-6596/2287/1/012023.
Testo completoAbstract (sommario):
Abstract This paper aims to complete the simulation of meshing of a pair of herringbone double circular-arc helical gears by using the multibody dynamic analysis software, SolidWorks motion. Three types of edge modifications, including no edge modification, chamfered edge modification, and rounded edge modification, are applied respectively to the pair of gears. The output angular velocities and contact regions corresponding with the three types of edge modifications are analyzed. Moreover, whether the center distance assembly error affects the output angular velocity and contact regions are analyzed. The results obtained by the simulation of meshing show that rounded edge modification is better than chamfered edge modification, and chamfered edge modification is better than no edge modification. The center distance assembly error has no effect on the output angular velocity and has little effect on the contact regions. Therefore, double circular-arc helical gears are not sensitive to center distance assembly errors.
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Dveirin, Oleksandr, Viktor Riabkov, Liudmyla Kapitanova e Danylo Kirnoson. "Методологія формування предметної області модифікаційних змін у важкому транспортному літаку". Aerospace Technic and Technology, n. 1 (27 febbraio 2023): 4–11. http://dx.doi.org/10.32620/aktt.2023.1.01.
Testo completoAbstract (sommario):
The subject of study is the process of forming the parameters of modification changes in a heavy transport aircraft. The goal is to develop the subject area of modification changes with the help of design models. The task is to develop models for determining the parameters of modification changes of the base aircraft based on the subject area of the modification project, namely: a model of the decomposition of modification changes of the base aircraft with the selection of parameter levels, which made it possible to apply more reliable assessment methods for different groups of parameters; a model of displaying the structure of the base aircraft in the subject area of the modification project, which uses the concepts of similarity and equivalence, it allows to highlight the necessary modification changes of the base aircraft; a temporal model of tracking efficiency changes, taking into account the time interval of creating modifications; a model for assessing the feasibility of modification changes in lower-level parameters, taking into account additional labor costs for their implementation. All this makes it possible to increase the reliability of the technical and economic justification of the modification. The methods used are following: an analytical method of defining the subject area using a system of new criteria that allow evaluating the integral characteristics of the aircraft modification for the benefit of different participants at different stages of the creation of the modification: for project developers, specific cost criteria are adopted as the ratio of all types of costs to all useful work, performed by the modification at the stage of its operation; for the stage of flight tests and production development in modifications – the criterion for the expediency of modification changes, taking into account the labor costs for their implementation; for operating airlines – the technology of formation of flight parameters, which provide a "niche" of competitiveness of modifications and temporary tariffs for the benefit of the consumer. The obtained scientific results: allow to form subject areas of promising modifications of heavy transport aircraft, which can reasonably compete in the world markets of aircraft and air transportation. Conclusion. The scientific novelty of the obtained results is as follows: the proposed model for determining the subject area of modification changes of the base aircraft. This makes it possible to set the parameters of modification changes in the aircraft at the stage of aircraft design, and thereby ensure its competitiveness in the aircraft and air transportation markets.
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Novák, Igor, Ivan Michalec, Marian Valentin, Milan Marônek, Ladislav Šoltés, Ján Matyašovský e Peter Jurkovič. "Steel Surface Modification". Vestnik Volgogradskogo gosudarstvennogo universiteta. Serija 10. Innovatcionnaia deiatel’nost’, n. 3 (20 ottobre 2014): 47–55. http://dx.doi.org/10.15688/jvolsu10.2014.3.6.
Testo completo
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Yu, Li Jing, e You Li Feng. "Researching Progress of Zeolite Modification and their Applications in Wastewater Treatment". Applied Mechanics and Materials 66-68 (luglio 2011): 1260–63. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.1260.
Testo completoAbstract (sommario):
Zeolite as a cheap mineral material in industry used in catalytic and environment protection, long time has passed for research on zeolite modification, synthesis and application. In the paper, several modifications for zeolite have been reviewed in detail such as the skeleton element modification, skeleton element modification and zeolite crystals surface modification, modified zeolite properties and application. The shortcomings of the modification methods were pointed out, development and zeolite modification suggestions in the future were put forward.
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Petrulis, Donatas, e Salvinija Petrulyte. "Packing Properties of Fibres in the Open-Packed Yarn Mode". Fibres and Textiles in Eastern Europe 25 (30 aprile 2017): 57–61. http://dx.doi.org/10.5604/12303666.1228171.
Testo completoAbstract (sommario):
Theoretical observations of the packing properties of non-compressible round fibres for two idealized modifications of the open-packed yarn model are discussed. The modifications differ in the method of arrangement of fibres within the cross-sectional ring layer. Modification I has a number of fibres regularly increasing in further layers, and Modification II has the fibres maximum packed in the layers. A procedure for obtaining the number of fibres in the layers of Modification II was proposed. The investigation showed that with the beginning of the 5th layer, the above-mentioned modifications have different packing properties. Because of additional fibres in the layers of Modification II, packing fractions in the layers and yarn obtained were greater if compared with those for Modification I. Analysis of packing properties was made up to 12 layers of the yarn model and also was done for a case of an infinitely large numbers of layers or fibres in a yarn.
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Yuan, Zhe, e Yu Guo. "Approach of Selecting Profile Modifications Curves for Spur Gears". Advanced Materials Research 499 (aprile 2012): 138–42. http://dx.doi.org/10.4028/www.scientific.net/amr.499.138.
Testo completoAbstract (sommario):
The tooth profile modification can generally choose straight line modification, parabolic modification and arc modification. In order to accurately determine the tooth profile modification curves, basing on analysis of the vibration that effected by transmission error, a pair of gears meshing process is simulated with FEM approach. Aiming at reducing the fluctuation of transmission error, the transmission error curves of straight line modification, parabolic modification and arc modification with the same modification parameters are plotted, and the best modifications curve is obtained. The research shows that the approach is accurate to choose the best modification curve, and reduce the fluctuation of transmission error greatly. The approach illustrated in this paper provides a new way for designing the noiseless gears.
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Marta, Herlina, Ari Rismawati, Giffary Pramafisi Soeherman, Yana Cahyana, Mohamad Djali, Tri Yuliana e Dewi Sondari. "The Effect of Dual-Modification by Heat-Moisture Treatment and Octenylsuccinylation on Physicochemical and Pasting Properties of Arrowroot Starch". Polymers 15, n. 15 (28 luglio 2023): 3215. http://dx.doi.org/10.3390/polym15153215.
Testo completoAbstract (sommario):
Starch is widely applied in various industrial sectors, including the food industry. Starch is used as a thickener, stabilizer, or emulsifier. However, arrowroot starch generally has weaknesses, such as unstable under heating and acidic conditions, which are generally applied to processing in the food industry. Modifications were applied to improve the characteristics of native arrowroot starch. In this study, arrowroot starch was modified by heat-moisture treatment (HMT), octenylsuccinylation (OSA), and dual modification between OSA and HMT in a different sequence––namely, HMT followed by OSA, and OSA followed by HMT. This study aims to determine the effect of different modification methods on the physicochemical and functional properties of native arrowroot starch. The result shows that both single HMT and dual modification caused damage to native starch granules, such as the formation of cracks and roughness. For single OSA treatment, especially, there is no significant change in granule morphology after modification. All modification treatments did not change the crystalline type of starch but reduced the RC of native starch. Both single HMT and dual modifications (HMT-OSA, OSA-HMT) increased pasting temperature and setback, but, conversely, decreased the peak and the breakdown viscosity of native starch, whereas single OSA had the opposite trend compared with the other modifications. HMT played a greater role in increasing the thermal stability and the retrogradation ability of arrowroot starch. Both single modifications (HMT and OSA) increased the hardness and gumminess of native starch, and the opposite was true for the dual modifications. HMT had a greater effect on color characteristics, where the lightness and whiteness index of native arrowroot starch decreased. Single OSA modification increased swelling volume higher than dual modification. Both single HMT and dual modifications increased water absorption capacity and decreased the oil absorption capacity of native arrowroot starch.
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Han, Dali, e Meng Michelle Xu. "RNA Modification in the Immune System". Annual Review of Immunology 41, n. 1 (26 aprile 2023): 73–98. http://dx.doi.org/10.1146/annurev-immunol-101921-045401.
Testo completoAbstract (sommario):
Characterization of RNA modifications has identified their distribution features and molecular functions. Dynamic changes in RNA modification on various forms of RNA are essential for the development and function of the immune system. In this review, we discuss the value of innovative RNA modification profiling technologies to uncover the function of these diverse, dynamic RNA modifications in various immune cells within healthy and diseased contexts. Further, we explore our current understanding of the mechanisms whereby aberrant RNA modifications modulate the immune milieu of the tumor microenvironment and point out outstanding research questions.
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Gunka, Volodymyr, Olena Astakhova, Yurii Hrynchuk, Iurii Sidun, Volodymyr Reutskyy, Iryna Mirchuk e Olha Poliak. "A Review of Road Bitumen Modification Methods. Part 1 – Physical Modification". Chemistry & Chemical Technology 18, n. 2 (14 giugno 2024): 295–304. http://dx.doi.org/10.23939/chcht18.02.295.
Testo completoAbstract (sommario):
The information in this study is based on a thorough review of recent articles related to the production of binders for road construction and the improvement of their performance properties. The main attention is paid to the physical modification of road bitumen with polymer modifiers. The influence of the three main types of polymers (thermoplastics, elastomers, and thermoplastic elastomers) on the main physical and mechanical properties of bitumen-polymer compositions is shown. The main technological parameters and features of the physical modification of bitumen by different types of polymer modifiers have been determined.
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Bensaad, Dhiya Eddine, Mohammed Saleh, Khalid Ismail e Youngseung Lee. "Recent Advances in Physical, Enzymatic, and Genetic Modifications of Starches". Jordan Journal of Agricultural Sciences 18, n. 3 (1 settembre 2022): 245–58. http://dx.doi.org/10.35516/jjas.v18i3.474.
Testo completoAbstract (sommario):
The current review presents the potential physical modification devised into thermal which includes pre-gelatinization and hydrothermal processing (i.e., annealing (ANN) and heat-moisture treatment (HMT)) and nonthermal modifications (i.e., high-pressure processing (HPP), micronization, ultrasonication, and pulsed electric field (PEF)). Rather than physical modification; enzymatic modification by single enzyme treatment, debranching enzymes, and multienzyme synergetic treatment was discussed. Genetic modification was also discussed as a potential starch modification for better utilization of starch.
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Spear, Morwenna J., Simon F. Curling, Athanasios Dimitriou e Graham A. Ormondroyd. "Review of Functional Treatments for Modified Wood". Coatings 11, n. 3 (12 marzo 2021): 327. http://dx.doi.org/10.3390/coatings11030327.
Testo completoAbstract (sommario):
Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.
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HAMID, ISSAM A., e MOHAMED ERRADI. "DYNAMIC EVOLUTION OF DISTRIBUTED SYSTEMS SPECIFICATIONS USING REFLECTIVE LANGUAGE". International Journal of Software Engineering and Knowledge Engineering 05, n. 04 (dicembre 1995): 511–40. http://dx.doi.org/10.1142/s0218194095000253.
Testo completoAbstract (sommario):
Recently, object-oriented specifications of distributed systems has gained more attention. The object-oriented approach is known for its flexibility for system construction. However, one of the major challenges is to provide facilities for the dynamic modifications of such specifications during the development and maintenance process. Yet, current work has not addressed the dynamic modifications of specifications of distributed systems. In this paper, we are concerned with formal description techniques that allow for the development and dynamic modification of executable specifications. A two-level model for the evolution of large object-oriented specifications is introduced. The first deals with the dynamic modifications of types (classes), while the second deals with modifications of modules. We have defined a set of structural and behavioral constraints to ensure specification consistency after modification at both levels. To allow dynamic modification of types and modules, we have developed a reflective object-oriented specification language which uses meta-objects to support the modification operations. In this language, types and modules are objects.
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Phillips, Stacia, Tarun Mishra, Siyu Huang e Li Wu. "Functional Impacts of Epitranscriptomic m6A Modification on HIV-1 Infection". Viruses 16, n. 1 (16 gennaio 2024): 127. http://dx.doi.org/10.3390/v16010127.
Testo completoAbstract (sommario):
Epitranscriptomic RNA modifications play a crucial role in the posttranscriptional regulation of gene expression. N6-methyladenosine (m6A) is the most prevalent internal modification of eukaryotic RNA and plays a pivotal role in RNA fate. RNA m6A modification is regulated by a group of cellular proteins, methyltransferases (writers) and demethylases (erasers), which add and remove the methyl group from adenosine, respectively. m6A modification is recognized by a group of cellular RNA-binding proteins (readers) that specifically bind to m6A-modified RNA, mediating effects on RNA stability, splicing, transport, and translation. The functional significance of m6A modification of viral and cellular RNA is an active area of virology research. In this review, we summarize and analyze the current literature on m6A modification of HIV-1 RNA, the multifaceted functions of m6A in regulating HIV-1 replication, and the role of viral RNA m6A modification in evading innate immune responses to infection. Furthermore, we briefly discuss the future directions and therapeutic implications of mechanistic studies of HIV-1 epitranscriptomic modifications.
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Li, Tianxing, Xiaotao An, Xiaozhong Deng, Jinfan Li e Yulong Li. "A New Tooth Profile Modification Method of Cycloidal Gears in Precision Reducers for Robots". Applied Sciences 10, n. 4 (13 febbraio 2020): 1266. http://dx.doi.org/10.3390/app10041266.
Testo completoAbstract (sommario):
The tooth profile modification of cycloidal gears is important in the design and manufacture of precision reducers or rotary vector (RV) reducers for robots. The traditional modification design of cycloidal gears is mainly realized by setting various machining parameters, such as the size and center position of the grinding wheel. The traditional modification design has some disadvantages such as complex modification calculation, uncontrollable tooth profile curve shape and unstable meshing performance. Therefore, a new tooth profile modification method is proposed based on the consideration of the comprehensive influences of pressure angle distribution, meshing backlash, tooth tip and root clearance. Taking the pressure angle and modifications of tooth profile as the parameters of the modification function and the meshing backlash of gear teeth as constraints, the mathematical model for tooth profile modifications is built. The modifications are superimposed on the normal direction of the theoretical profile—the force transmission direction. The mathematical relationship between the modifications and the pressure angle distribution, which determines the force transmission performance, is established. Taking the straight line method, cycloid method and catenary method as examples, by means of the tooth contact analysis technology, the transmission error and minimum meshing backlash, which reflects the lost motion, of the newly modified profile are analyzed and verified. This proposed method can flexibly control the shape change of the modification profile and accurately pre-control the transmission accuracy of the cycloid-pin gear. It avoids the disadvantages of traditional modification methods, such as uncontrollable tooth profile shape and unstable meshing accuracy. The method allows good meshing characteristics, high force transmission performance and more precise tooth profile curve. The study provides a new design method of the modified profile of cycloidal gears.
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Ding, Hongxu, Andrew D. Bailey, Miten Jain, Hugh Olsen e Benedict Paten. "Gaussian mixture model-based unsupervised nucleotide modification number detection using nanopore-sequencing readouts". Bioinformatics 36, n. 19 (29 giugno 2020): 4928–34. http://dx.doi.org/10.1093/bioinformatics/btaa601.
Testo completoAbstract (sommario):
Abstract Motivation Nucleotide modification status can be decoded from the Oxford Nanopore Technologies nanopore-sequencing ionic current signals. Although various algorithms have been developed for nanopore-sequencing-based modification analysis, more detailed characterizations, such as modification numbers, corresponding signal levels and proportions are still lacking. Results We present a framework for the unsupervised determination of the number of nucleotide modifications from nanopore-sequencing readouts. We demonstrate the approach can effectively recapitulate the number of modifications, the corresponding ionic current signal levels, as well as mixing proportions under both DNA and RNA contexts. We further show, by integrating information from multiple detected modification regions, that the modification status of DNA and RNA molecules can be inferred. This method forms a key step of de novo characterization of nucleotide modifications, shedding light on the interpretation of various biological questions. Availability and implementation Modified nanopolish: https://github.com/adbailey4/nanopolish/tree/cigar_output. All other codes used to reproduce the results: https://github.com/hd2326/ModificationNumber. Supplementary information Supplementary data are available at Bioinformatics online.
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Khairul Anwar Mohd Dahuri, Mohd, Mohd Nasir Hussain, Nor Fasiha Mohd Yusof e Mohamad Kasim Abdul Jalil. "Preferential factors and usability effects on vehicle modifications for the Malaysian independent disabled driver". International Journal of Engineering & Technology 7, n. 2.29 (22 maggio 2018): 781. http://dx.doi.org/10.14419/ijet.v7i2.29.14256.
Testo completoAbstract (sommario):
The usability of driving modifications for a person with disabilities is known to be an important aspect in addressing the independent vehicle’s driving capabilities. The existence of assistive modifications such as hand control, secondary control, foot control, and also the wheelchair assisted vehicle, which were developed to accommodate limitations were found to be widely used. A survey was conducted on 202 Malaysian independent disabled drivers from Kuala Lumpur, Selangor, Perak, Johor Baharu, Terengganu, and also Melaka. The components evaluated in the survey include the origin of modification used for driving, factors influencing the decision on the type of vehicle modification, usability difficulties when modification is in use, the satisfaction level of product appearance, as well as to understand user preferences when making decisions between modifications. A Likert scale of 1 to 5 was used as measurement, in order to rate the score given by the responses for each question in the survey. As a result, it was discovered that aspects such as the modification colour, shape, the toggle, pedal grip, regulation, modification availability, and movement limitation on the involved body part are among the major factors influencing the driver to make modification for driving purposes. Major factors were also found to influence the driving modification preferences to suit the category of disabilities. It was also discovered that components such as the availability of modification information and emergency driving situations are some of the least important factors influencing the decision to make and select a suitable driving modification. However, these less important components must not be ignored as it also contributes to the improvement for independent disabled driving, and also for the purpose of assistive product development.
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Alleyn, Matthew, Mason Breitzig, Richard Lockey e Narasaiah Kolliputi. "The dawn of succinylation: a posttranslational modification". American Journal of Physiology-Cell Physiology 314, n. 2 (1 febbraio 2018): C228—C232. http://dx.doi.org/10.1152/ajpcell.00148.2017.
Testo completoAbstract (sommario):
Posttranslational modifications affect almost all proteins and are critical to a well-functioning and diverse proteome; however, many modifications remain relatively unknown and unstudied. This paper will give a perspective on the rapidly developing, novel posttranslational modification called succinylation. This modification may be implicated in numerous diseases, such as hepatic, cardiac, and pulmonary diseases. Although the influences of this modification still remain poorly understood, we are confident that further research into succinylation will provide an enhanced understanding of the complex machinery within the mitochondria, as well as the imposing consequences associated with its dysfunction.
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Puja, Ign Wiratmaja, Khalid e S. Weij. "Crash Zone Development for Railway Vehicle". Key Engineering Materials 306-308 (marzo 2006): 321–26. http://dx.doi.org/10.4028/www.scientific.net/kem.306-308.321.
Testo completoAbstract (sommario):
This paper considers crash zone development for railway vehicle to improve it’s crashworthiness characteristics. The principle of modification is by weakening the crash zone area and strengthening the passenger area. Thus the huge impact energy during collision will be absorbed by crash zone area so that it will maintain the structural integrity of the passengers. There are two type of modifications proposed in this study. The first modification is conducted by weakening the end-under-frame section and strengthening the middle-under-frame section. These modification shows deformation characteristics improvement where the passenger area structure are not suffered from buckling and plastic deformation as expected. The second type of modification is full modification on end-under-frame. These modifications give better improvement on the deformation and energy absorption characteristics, however in the practical application, this will be more expensive option.
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Schäck, Manfred A., Kim Philipp Jablonski, Stefan Gräf, Roland Klassen, Raffael Schaffrath, Stefanie Kellner e Christian Hammann. "Eukaryotic life without tQCUG: the role of Elongator-dependent tRNA modifications in Dictyostelium discoideum". Nucleic Acids Research 48, n. 14 (1 luglio 2020): 7899–913. http://dx.doi.org/10.1093/nar/gkaa560.
Testo completoAbstract (sommario):
Abstract In the Elongator-dependent modification pathway, chemical modifications are introduced at the wobble uridines at position 34 in transfer RNAs (tRNAs), which serve to optimize codon translation rates. Here, we show that this three-step modification pathway exists in Dictyostelium discoideum, model of the evolutionary superfamily Amoebozoa. Not only are previously established modifications observable by mass spectrometry in strains with the most conserved genes of each step deleted, but also additional modifications are detected, indicating a certain plasticity of the pathway in the amoeba. Unlike described for yeast, D. discoideum allows for an unconditional deletion of the single tQCUG gene, as long as the Elongator-dependent modification pathway is intact. In gene deletion strains of the modification pathway, protein amounts are significantly reduced as shown by flow cytometry and Western blotting, using strains expressing different glutamine leader constructs fused to GFP. Most dramatic are these effects, when the tQCUG gene is deleted, or Elp3, the catalytic component of the Elongator complex is missing. In addition, Elp3 is the most strongly conserved protein of the modification pathway, as our phylogenetic analysis reveals. The implications of this observation are discussed with respect to the evolutionary age of the components acting in the Elongator-dependent modification pathway.
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Meyer, Britta, Carina Immer, Steffen Kaiser, Sunny Sharma, Jun Yang, Peter Watzinger, Lena Weiß et al. "Identification of the 3-amino-3-carboxypropyl (acp) transferase enzyme responsible for acp3U formation at position 47 in Escherichia coli tRNAs". Nucleic Acids Research 48, n. 3 (21 dicembre 2019): 1435–50. http://dx.doi.org/10.1093/nar/gkz1191.
Testo completoAbstract (sommario):
Abstract tRNAs from all domains of life contain modified nucleotides. However, even for the experimentally most thoroughly characterized model organism Escherichia coli not all tRNA modification enzymes are known. In particular, no enzyme has been found yet for introducing the acp3U modification at position 47 in the variable loop of eight E. coli tRNAs. Here we identify the so far functionally uncharacterized YfiP protein as the SAM-dependent 3-amino-3-carboxypropyl transferase catalyzing this modification and thereby extend the list of known tRNA modification enzymes in E. coli. Similar to the Tsr3 enzymes that introduce acp modifications at U or m1Ψ nucleotides in rRNAs this protein contains a DTW domain suggesting that acp transfer reactions to RNA nucleotides are a general function of DTW domain containing proteins. The introduction of the acp3U-47 modification in E. coli tRNAs is promoted by the presence of the m7G-46 modification as well as by growth in rich medium. However, a deletion of the enzymes responsible for the modifications at position 46 and 47 in the variable loop of E. coli tRNAs did not lead to a clearly discernible phenotype suggesting that these two modifications play only a minor role in ensuring the proper function of tRNAs in E. coli.
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Pongsapan, Allo Sarira, e Rombe Allo. "ANALISIS UNJUK KERJA POMPA SENTRIFUGAL DENGAN PEMASANGAN INDUCER PADA LOCK NUT IMPELLER". Jurnal Teknik AMATA 3, n. 2 (3 dicembre 2022): 17–25. http://dx.doi.org/10.55334/jtam.v3i2.298.
Testo completoAbstract (sommario):
Centrifugal pumps are the most widely used fluid machines in our daily life. In operation there are many losses caused by the installation and construction of the pump itself. Many studies have been carried out to minimize these losses, including the research we did, namely in the form of modifications to the centrifugal pump inlet. This study aims to determine the effect of installing the inducer on the locknut impeller on the characteristics of a radial flow type centrifugal pump. Here what is meant by pump characteristics are head, discharge, and pump efficiency. The method used is experimental. The activities carried out in this study included: designing and assembling simple pump testing equipment, making specimens, collecting data, analyzing and discussing and concluding. In this study there were four types of tests, namely: 1) Centrifugal pump without modification (normal); 2) Pump of the 1st modification with inducer, 25 mm long; 3) Pump of the 2nd modification with inducer, length 50 mm; and 4) Pump modification 3rd with inducer, length 75 mm. Research shows that modifications can improve the characteristics of centrifugal pumps which are the object of research where there is an increase in total head (Htot), discharge (Q) and efficiency (ηp). The best characteristics were obtained from the 2nd modification pump with an inducer length of 50 mm, followed by the 3rd modification pump with an inducer length of 75 mm, the 1st modification pump with an inducer length of 25 mm and the lowest was the pump without modification (normal). Characteristics of centrifugal pumps This increase is due to modifications that minimize pre-rotation symptoms, turbulence, and flow separation. Or in other words, the modification causes an improvement in the flow pattern at the inlet of the centrifugal pump.
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Froese, Vincent, Leon Kellerhals e Rolf Niedermeier. "Modification-Fair Cluster Editing". Proceedings of the AAAI Conference on Artificial Intelligence 36, n. 6 (28 giugno 2022): 6631–38. http://dx.doi.org/10.1609/aaai.v36i6.20617.
Testo completoAbstract (sommario):
The classic Cluster Editing problem (also known as Correlation Clustering) asks to transform a given graph into a disjoint union of cliques (clusters) by a small number of edge modifications. When applied to vertex-colored graphs (the colors representing subgroups), standard algorithms for the NP-hard Cluster Editing problem may yield solutions that are biased towards subgroups of data (e.g., demographic groups), measured in the number of modifications incident to the members of the subgroups. We propose a modification fairness constraint which ensures that the number of edits incident to each subgroup is proportional to its size. To start with, we study Modification-Fair Cluster Editing for graphs with two vertex colors. We show that the problem is NP-hard even if one may only insert edges within a subgroup; note that in the classic "non-fair" setting, this case is trivially polynomial-time solvable. However, in the more general editing form, the modification-fair variant remains fixed-parameter tractable with respect to the number of edge edits. We complement these and further theoretical results with an empirical analysis of our model on real-world social networks where we find that the price of modification-fairness is surprisingly low, that is, the cost of optimal modification-fair differs from the cost of optimal "non-fair" solutions only by a small percentage.
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Kim, Geon-Woo, e Aleem Siddiqui. "Hepatitis B virus X protein recruits methyltransferases to affect cotranscriptional N6-methyladenosine modification of viral/host RNAs". Proceedings of the National Academy of Sciences 118, n. 3 (4 gennaio 2021): e2019455118. http://dx.doi.org/10.1073/pnas.2019455118.
Testo completoAbstract (sommario):
Chronic hepatitis B virus (HBV) infections are one of the leading causes of cirrhosis and hepatocellular carcinoma. N6-methyladenosine (m6A) modification of cellular and viral RNAs is the most prevalent internal modification that occurs cotranscriptionally. Previously, we reported the dual functional role of m6A modification of HBV transcripts in the viral life cycle. Here, we show that viral HBV X (HBx) protein is responsible for the m6A modifications of viral transcripts. HBV genomes defective in HBx failed to induce m6A modifications of HBV RNAs during infection/transfection, while ectopic expression of HBx restores m6A modifications of the viral RNAs but not the mutant HBx carrying the nuclear export signal. Using chromatin immunoprecipitation assays, we provide evidence that HBx and m6A methyltransferase complexes are localized on the HBV minichromosome to achieve cotranscriptional m6A modification of viral RNAs. HBx interacts with METTL3 and 14 to carry out methylation activity and also modestly stimulates their nuclear import. This role of HBx in mediating m6A modification also extends to host phosphatase and tensin homolog (PTEN) mRNA. This study provides insight into how a viral protein recruits RNA methylation machinery to m6A-modify RNAs.
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Meza, Rosemary D., Nathaniel Jungbluth, Georganna Sedlar, Prerna Martin, Lucy Berliner, Shannon Wiltsey-Stirman e Shannon Dorsey. "Clinician-Reported Modification to a CBT Approach in Children’s Mental Health". Journal of Emotional and Behavioral Disorders 28, n. 2 (13 febbraio 2019): 104–13. http://dx.doi.org/10.1177/1063426619828369.
Testo completoAbstract (sommario):
Examining the nature and determinants of evidence-based treatment (EBT) modification is an important step toward understanding the impact of modifications and informing modification guidelines. We examined the prevalence, types, reasons for, and predictors of clinician-reported modification to cognitive behavioral therapy (CBT) for children and adolescents. Ninety-eight clinicians trained in CBT completed surveys on their intent to modify CBT, perceptions of CBT characteristics, confidence in their ability to appropriately deliver CBT in complex clinical situations, and organizational EBT implementation climate post-training. Post-consultation, clinicians self-reported the types and reasons for modifications they performed. Ninety-three percent of clinicians reported they modified CBT, primarily with fewer than half of their clients. Client needs and clinician preference or style accounted for the highest proportion of modification reasons. The number of reported modifications performed was predicted by clinician confidence in their ability to deliver CBT appropriately ( b = .90, p = .01) and their intent to modify ( b = .55, p = .01).
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Subroto, Edy, Yana Cahyana, Rossi Indiarto e Tiara Aray Rahmah. "Modification of Starches and Flours by Acetylation and Its Dual Modifications: A Review of Impact on Physicochemical Properties and Their Applications". Polymers 15, n. 14 (9 luglio 2023): 2990. http://dx.doi.org/10.3390/polym15142990.
Testo completoAbstract (sommario):
Various modification treatments have been carried out to improve the physicochemical and functional properties of various types of starch and flour. Modification by acetylation has been widely used to improve the quality and stability of starch. This review describes the effects of acetylation modification and its dual modifications on the physicochemical properties of starch/flour and their applications. Acetylation can increase swelling power, swelling volume, water/oil absorption capacity, and retrogradation stability. The dual modification of acetylation with cross-linking or hydrothermal treatment can improve the thermal stability of starch/flour. However, the results of the modifications may vary depending on the type of starch, reagents, and processing methods. Acetylated starch can be used as an encapsulant for nanoparticles, biofilms, adhesives, fat replacers, and other products with better paste stability and clarity. A comparison of various characteristics of acetylated starches and their dual modifications is expected to be a reference for developing and applying acetylated starches/flours in various fields and products.
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Mao, Shuangshuang, Zuhua Chen, Yingying Wu, Huihua Xiong e Xianglin Yuan. "Crosstalk of Eight Types of RNA Modification Regulators Defines Tumor Microenvironments, Cancer Hallmarks, and Prognosis of Lung Adenocarcinoma". Journal of Oncology 2022 (11 luglio 2022): 1–19. http://dx.doi.org/10.1155/2022/1285632.
Testo completoAbstract (sommario):
RNA modification has become an exciting underexplored field in recent years. In lung adenocarcinoma (LUAD), m6A was the best characterized and most studied RNA modification, while knowledge about other kinds of RNA modifications in LUAD is limited. In our study, we included a total of 100 RNA modification regulators of eight types of cancer-related RNA modifications (m6A, m1A, m5C, Nm, m7G, Ψ, A-to-I, and mcm5s2U) to systematically profile their specific roles in LUAD. By gene mutation and expression analysis, we identified extensive dysregulations and complicated interactions of 100 RNA modification regulators in LUAD. Based on unsupervised clustering analysis, gene set variation analysis (GSVA), and single-sample gene-set enrichment analysis (ssGSEA), two RNA modification patterns in LUAD were defined to show distinct biological characteristics. The favorable prognostic pattern was enriched with infiltrated immune cells, including activated B cells, CD8 T cells, eosinophil cells, dendritic cells, and natural killer cells, while the unfavorable prognostic pattern was enriched with cancer hallmarks, including hypoxia, epithelial-mesenchymal transition (EMT), angiogenesis, PI3K-AKT-mTOR pathway, MYC pathway, and glycolysis pathway. We also constructed an RNA modification score (RMScore) based on five critical genes (CYP17A1, NTSR1, PITX3, KRT6A, and ANLN) to evaluate the RNA modification status of individual LUAD patients. RMScore was revealed to be related to the infiltrated immune cells and cancer hallmarks and was an independent prognostic factor in the TCGA-LUAD cohort and two external GEO-LUAD cohorts. Our study was the first to comprehensively investigate the dysregulations, crosstalk, and potential prognostic value of eight types of RNA modifications in LUAD. Our results highlighted the significance of eight types of RNA modifications in tumor microenvironments and cancer hallmarks and provided novel prognostic biomarkers and potential therapeutic targets in the management of LUAD patients in the future.
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TUHVATULLIN, Midhat, Yuri ARKHANGELSKY, Rustam AIPOV e Eduard KHASANOV. "Innovations in designing microwave electro-technological units with hybrid chambers". Spanish Journal of Agricultural Research 21, n. 1 (23 febbraio 2023): e0202. http://dx.doi.org/10.5424/sjar/2023211-19683.
Testo completoAbstract (sommario):
Aim of study: Microwave (MW) electro-technological units based on electromagnetic radiation of ultrahigh-frequency can involve thermal MW modification of dielectrics and non-thermal MW modification of polymers.
Area of study: Russian Federation.
Material and methods: The paper considers a method for making a unit with a hybrid chamber, where thermal and non-thermal MW modifications were carried out simultaneously, and the remaining energy after non-thermal MW modification of polymers was used for heating the dielectric.
Main results: A microwave electro-technological unit with a hybrid chamber replaced two separate devices that implemented these MW modifications. It was cheaper and required one MW generator. The unit took up less space than two separate apparatuses, and upgraded the existing microwave dryer to perform thermal MW modification of a lumber pile and non-thermal MW modification of polymer materials. The existing microwave dryer was redeveloped by solving the boundary value problem in electrodynamics and heat and mass transfer.
Research highlights: The research presents a microwave electro-technological unit with a hybrid chamber, combining thermal and non-thermal MW modifications of dielectric and polymer materials. As a result of upgrading the existing microwave dryer, it was possible to carry out both thermal and non-thermal MW modifications, namely, microwave drying of timber and microwave drying of up to seven different polymer objects.
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Yang, Weiwei, Alexey Fomenkov, Dan Heiter, Shuang-yong Xu e Laurence Ettwiller. "High-throughput sequencing of EcoWI restriction fragments maps the genome-wide landscape of phosphorothioate modification at base resolution". PLOS Genetics 18, n. 9 (19 settembre 2022): e1010389. http://dx.doi.org/10.1371/journal.pgen.1010389.
Testo completoAbstract (sommario):
Phosphorothioation (PT), in which a non-bridging oxygen is replaced by a sulfur, is one of the rare modifications discovered in bacteria and archaea that occurs on the sugar-phosphate backbone as opposed to the nucleobase moiety of DNA. While PT modification is widespread in the prokaryotic kingdom, how PT modifications are distributed in the genomes and their exact roles in the cell remain to be defined. In this study, we developed a simple and convenient technique called EcoWI-seq based on a modification-dependent restriction endonuclease to identify genomic positions of PT modifications. EcoWI-seq shows similar performance than other PT modification detection techniques and additionally, is easily scalable while requiring little starting material. As a proof of principle, we applied EcoWI-seq to map the PT modifications at base resolution in the genomes of both the Salmonella enterica cerro 87 and E. coli expressing the dnd+ gene cluster. Specifically, we address whether the partial establishment of modified PT positions is a stochastic or deterministic process. EcoWI-seq reveals a systematic usage of the same subset of target sites in clones for which the PT modification has been independently established.
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PEGO, MATHEUS, JANAÍNA CARVALHO e DAVID GUEDES. "SURFACE MODIFICATIONS OF ACTIVATED CARBON AND ITS IMPACT ON APPLICATION". Surface Review and Letters 26, n. 01 (gennaio 2019): 1830006. http://dx.doi.org/10.1142/s0218625x1830006x.
Testo completoAbstract (sommario):
The main and new surface modification methods of activated carbon (AC) and their influence on application (adsorption capacity) were reviewed. Adsorption capacity is an important issue, contributing to hazardous substances environment management. According to literature, it is true that surface chemistry strongly affects adsorption capacity. Surface chemistry can be modified by several methods that lead to different activated carbon properties. Furthermore, adsorbate properties, and their relationships with surface structure, can impact adsorption properties. Surface modifications can be conducted by adding some atoms to the surface structure, making the surface more acidic or basic. Introduction of oxygen and ammonia atoms (chemical modification) are the main processes to make the surface more acidic and basic, respectively, although may bring chemical wastes to environment. Surface modification is done by chemical and physical modifications that lead activated carbons to present different properties. The main and new methods of chemical and physical modifications are compared and presented in this paper. Some new physical methods, like corona treatment, plasma discharge and microwave radiation, can be applied to cause surface modifications. Corona treatment can be a practical and new way to cause surface modification on an activated carbon surface.
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Jeníček, V. "Modification of sustainability indicators". Agricultural Economics (Zemědělská ekonomika) 59, No. 4 (25 aprile 2013): 160–66. http://dx.doi.org/10.17221/12/2012-agricecon.
Testo completoAbstract (sommario):
During time, a more attention was paid to the sustainability indicators. While formerly they regarded only the environment area, gradually they were extended also to the social, economic and institutional sphere. However, their use is rather problematic in developing countries the majority of which was not persuaded of their importance. Developing countries also often reason that they have not the relevant data to their disposal.
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Marta, Herlina, Hana Nur Layalia Hasya, Zahra Indah Lestari, Yana Cahyana, Heni Radiani Arifin e Siti Nurhasanah. "Study of Changes in Crystallinity and Functional Properties of Modified Sago Starch (Metroxylon sp.) Using Physical and Chemical Treatment". Polymers 14, n. 22 (10 novembre 2022): 4845. http://dx.doi.org/10.3390/polym14224845.
Testo completoAbstract (sommario):
Sago starch has weaknesses such as low thermal stability and high syneresis. Modifications were made to improve the characteristics of native sago starch. In this study, sago starch was modified by autoclave-heating treatment (AHT), osmotic-pressure treatment (OPT), octenyl-succinic anhydride modification (OSA), and citric acid cross-linking (CA). This study aimed to examine the changes in chemical composition, crystallinity, and functional properties of the native sago starch after physical and chemical modifications. The results show that physical modification caused greater granule damage than chemical modification. All modification treatments did not alter the type of crystallinity but decreased the relative crystallinity of native starch. New functional groups were formed in chemically modified starches at a wavelength of 1700–1725 cm−1. The degree of order (DO) and degree of double helix (DD) of the modified starches were also not significantly different from the native sample, except for AHT and OPT, respectively. Physical modification decreased the swelling volume, while chemical modification increased its value and is inversely proportional to solubility. AHT and OPT starches have the best freeze–thaw stability among others, indicating that both starches have the potential to be applied in frozen food.
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Glans, M., S. Bejerot e J. Dossou Nilsson. "Tattooing and piercing are associated with symptoms of ADHD: A cross-sectional study of non-clinical adults". European Psychiatry 65, S1 (giugno 2022): S84—S85. http://dx.doi.org/10.1192/j.eurpsy.2022.255.
Testo completoAbstract (sommario):
Introduction Previous studies suggest that individuals with tattoos and piercings exhibit higher impulsive personality traits compared to peers without body modifications. No studies on body modifications and core-symptoms of ADHD are available. Objectives This study aimed to compare self-reported ADHD symptoms between non-clinical adults with and without body modifications. Methods A non-clinical adult Swedish population (n=815) completed the Adult ADHD self-report scale (ASRS-v1.1) and answered questions concerning body modification. ADHD diagnosis served as exclusion criterion. Three grouping variables were analysed separately; tattoo status, piercing status and a combination of having both tattoo and piercing. Linear regression compared mean ASRS total- and subscale scores between individuals with and without body modification according to each grouping variable, while adjusting for candidate covariates age and sex. Results The prevalence of each body modification variable was; 30% for tattoo, 18% for piercing other than earlobe and 12% for combination of tattoo and piercing. Any combination of body modification was associated with significantly higher ASRS total- and subscale scores compared to no body modification. The most pronounced differences between groups were for the combination of tattoo and piercing, and on the hyperactivity/impulsivity (HI) subscale; revealing adjusted mean differences of 4.3 points (range 0-72) on the ASRS-total score (p <0.001) and 2.6 points (range 0-36) on the ASRS HI subscale (p <0.001). Conclusions Body modification was associated with more pronounced ADHD core symptoms amongst non-clinical adults. Although statistically significant, the clinical significance is uncertain. The prevalence rates of body modifications in our cohort indicate that they are becoming cultural normal. Disclosure No significant relationships.
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Baccini, Federica, Monica Bianchini e Filippo Geraci. "Graph-Based Integration of Histone Modification Profiles". Mathematics 10, n. 11 (27 maggio 2022): 1842. http://dx.doi.org/10.3390/math10111842.
Testo completoAbstract (sommario):
In this work, we introduce a similarity-network-based approach to explore the role of interacting single-cell histone modification signals in haematopoiesis—the process of differentiation of blood cells. Histones are proteins that provide structural support to chromosomes. They are subject to chemical modifications—acetylation or methylation—that affect the degree of accessibility of genes and, in turn, the formation of different phenotypes. The concentration of histone modifications can be modelled as a continuous signal, which can be used to build single-cell profiles. In the present work, the profiles of cell types involved in haematopoiesis are built based on all the major histone modifications (i.e., H3K27ac, H3K27me3, H3K36me3, H3K4me1, H3K4me3, H3K9me3) by counting the number of peaks in the modification signals; then, the profiles are used to compute modification-specific similarity networks among the considered phenotypes. As histone modifications come as interacting signals, we applied a similarity network fusion technique to integrate these networks in a unique graph, with the aim of studying the simultaneous effect of all the modifications for the determination of different phenotypes. The networks permit defining of a graph-cut-based separation score for evaluating the homogeneity of subgroups of cell types corresponding to the myeloid and lymphoid phenotypes in the classical representation of the haematopoietic tree. Resulting scores show that separation into myeloid and lymphoid phenotypes reflects the actual process of haematopoiesis.
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DeZern, Amy E., Gary Binder, Albert Fliss, X. Henry Hu, Syed Rizvi, Frank A. Corvino, Steven R. Arikian, Andy Surinach, Jianyi Lee e B. Douglas Smith. "Relationship Between Lenalidomide Dose Modification and Outcomes in Patients with Myelodysplastic Syndromes". Blood 126, n. 23 (3 dicembre 2015): 3286. http://dx.doi.org/10.1182/blood.v126.23.3286.3286.
Testo completoAbstract (sommario):
Abstract Introduction: In clinical studies of patients (pts) with International Prognostic Scoring System (IPSS)-defined Low- to Intermediate-1-risk myelodysplastic syndromes (MDS), dose modification of lenalidomide (LEN) has been commonly used by physicians to sustain control of disease while managing toxicities. A previous real-world setting analysis has shown that dose modification of LEN in pts with multiple myeloma was associated with longer duration of therapy (DOT) and improved outcomes versus pts without dose modification (Usmani SZ, et al. Blood. 2014;124:abstract 2655). This study aimed to evaluate whether LEN dose modification in pts with MDS is associated with longer DOT and improved outcomes in a real-world setting using various measures available from claims data. Methods: A retrospective study was conducted using a large US medical and pharmacy claims database, covering > 25 million commercial- and Medicare-insured lives annually. MDS pts with ≥ 2 outpatient claims or ≥ 1 inpatient medical claim associated with a diagnosis of MDS (ICD-9-CM codes 238.72-238.75) were identified; the first such claim was defined as the index date. A minimum of 12 months' pre-index enrollment and 6 months' post-index continuous enrollment between Jan 1, 2008 and Dec 31, 2013 was required. The inclusion criteria included pts with MDS treated with LEN who did not have claims for stem cell transplantation or high-risk disease at diagnosis. Clinically relevant metrics, including DOT, time to acute myeloid leukemia (AML), time to next therapy, time to advancement to high-risk disease (as measured by ICD-9-CM code 238.73), and time to red blood cell transfusion dependence, were compared in pts with and without LEN dose modifications (defined as: change in dose [mg/day], dose interruption of 10-60 days, or both); time-to-progression (TTP) was defined as a composite of the above. Charlson Comorbidity Index (CCI) and MDS Comorbidity Index (MDS-CI) (Della Porta MG, et al. Haematologica. 2011;96:441-9) scores were determined to compare baseline measures between groups. Adjusted hazard ratios (HRs) were calculated using a Cox proportional hazards model adjusted for age group, sex, and MDS-CI risk group at LEN initiation. Results: Of 529 pts who met inclusion criteria, 245 (46%) had LEN dose modifications, including 135 pts with ≥ 1 dose change and 201 pts with ≥ 1 dose interruption; 91 pts had both. Overall, 54% of pts were aged ≥ 75 years; age (P = 0.647), CCI (P = 0.867), and MDS-CI (P = 0.967) did not differ between pts managed with and without LEN dose modifications. For pts without dose modifications, the rate of cytopenias within 14 days prior to discontinuation (50.7%) did not significantly differ from the rate of cytopenias within 14 days prior to first modification for pts with dose modifications (50.2%; P = 0.920). Median time to first dose modification was 1.9 months (range 0.4-23.2). Median DOT was 12.6 months for pts with LEN dose modification versus 1.9 months for pts without dose modification (P < 0.0001). The DOT benefit did not differ whether the modification was a dose change or an interruption (P = 0.115). Most pts initiated LEN at a 10 mg/day dose; the most common change for those who modified was to reduce to a 5 mg/day dose. Median TTP was 20.6 months for pts with dose modification versus 13.7 months for those without; the adjusted HR was 0.703 (95% confidence interval 0.541-0.914) (P = 0.009). Pts with dose modification had statistically significant improvements in time to AML (P = 0.018), time to next therapy (P = 0.002), and time to high-risk disease (P = 0.043) compared with pts without dose modification. Conclusions: For pts medically managed with lenalidomide treatment for myelodysplastic syndromes in the USA, dose modifications during their treatment were associated with longer therapy duration, improvement in time to progression to AML or high-risk disease, and improved time to next therapy compared with pts without lenalidomide dose modification. Modifications were utilized in 46% of pts and the median time to modifications was similar to the DOT in those not receiving modifications, suggesting dose modifications may be worth considering for some pts who discontinue lenalidomide. This analysis supports lenalidomide dose modification in the treatment of MDS as an effective technique in the real-world setting for pts to achieve better treatment outcomes based on proxy measures available from claims data. Disclosures Binder: Celgene Corporation: Employment, Equity Ownership. Fliss:Celgene Corporation: Employment, Equity Ownership. Hu:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Rizvi:Celgene Corporation: Employment, Equity Ownership. Corvino:Genesis Research LLC: Consultancy. Arikian:Genesis Research LLC: Consultancy. Surinach:Genesis Research LLC: Consultancy. Lee:Genesis Research LLC: Consultancy.
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Nurse, Jalisa, Aubee Joseph e Karl M. Thompson. "444 Post-translational role of RNA modifications in sRNA chaperone Hfq". Journal of Clinical and Translational Science 6, s1 (aprile 2022): 88. http://dx.doi.org/10.1017/cts.2022.260.
Testo completoAbstract (sommario):
OBJECTIVES/GOALS: The goal of this study is to determine the role of the tRNA modifications in the translation of Hfq. Hfq is an RNA chaperone that acts as a co-factor for the action of the largest class of small RNAs in E. coli. RNA modifications have been known to play critical roles in the translational fidelity of many cellular proteins in bacteria. METHODS/STUDY POPULATION: In this study, we used an hfq-lacZ translation fusion to screen several RNA modification mutant genes to uncover additional RNA modifications that may play a role in Hfq translation. We measured hfq-lacZ activity in genetic backgrounds mutated for several additional RNA modification enzymes previously untested for Hfq effects. RESULTS/ANTICIPATED RESULTS: We identified 5 RNA modification genes that were defective for hfq-lacZ fusion activity, and we subsequently performed western blot analysis on the Hfq protein in the absence of these modification mutant genes to determine the effect of these mutants more directly on Hfq protein levels. We identified 2 out of these 5 RNA modification mutants that also affect Hfq protein levels. DISCUSSION/SIGNIFICANCE: Since Hfq is critically important for small RNA function is a wide range of bacteria, it is possible tRNA modifications regulate Hfq expression in other bacteria. These processes, when further investigated, could provide us with the basic information to develop new antibiotics needed to address emerging antibiotic resistance.
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Schwartz, Daniel. "Prediction of lysine post-translational modifications using bioinformatic tools". Essays in Biochemistry 52 (25 maggio 2012): 165–77. http://dx.doi.org/10.1042/bse0520165.
Testo completoAbstract (sommario):
Our understanding of the importance of lysine post-translational modifications in mediating protein function has led to a significant improvement in the experimental tools aimed at characterizing their existence. Nevertheless, it remains likely that at present we have only experimentally detected a small fraction of all lysine modification sites across the commonly studied proteomes. As a result, online computational tools aimed at predicting lysine modification sites have the potential to provide valuable insight to researchers developing hypotheses regarding these modifications. This chapter discusses the metrics and procedures used to assess predictive tools and surveys 11 online computational tools aimed at the prediction of the four most widely studied lysine post-translational modifications (acetylation, methylation, SUMOylation and ubiquitination). Analyses using unbiased testing data sets suggest that nine of the 11 lysine post-translational modification tools perform no better than random, or have false-positive rates which make them unusable by the experimental biologist, despite self-reported sensitivity and specificity values to the contrary. The implications of these findings for those using and creating lysine post-translational modification software are discussed.
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Lee, Chinwai, Hsiang Hsi Lin, Fred B. Oswald e Dennis P. Townsend. "Influence of Linear Profile Modification and Loading Conditions on The Dynamic Tooth Load and Stress of High-Contact-Ratio Spur Gears". Journal of Mechanical Design 113, n. 4 (1 dicembre 1991): 473–80. http://dx.doi.org/10.1115/1.2912807.
Testo completoAbstract (sommario):
This paper presents a computer simulation for the dynamic response of high-contact-ratio spur gear transmissions. High contact ratio gears have the potential to produce lower dynamic tooth loads and minimum root stress but they can be sensitive to tooth profile errors. The analysis presented in this paper examines various profile modifications under realistic loading conditions. The effect of these modifications on the dynamic load (force) between mating gear teeth and the dynamic root stress is presented. Since the contact stress is dependent on the dynamic load, minimizing dynamic loads will also minimize contact stresses. This paper shows that the combination of profile modification and the applied load (torque) carried by a gear system has a significant influence on gear dynamics. The ideal modification at one value of applied load will not be the best solution for a different load. High-contact-ratio gears were found to require less modification than standard low-contact-ratio gears. High-contact-ratio gears are more adversely affected by excess modification than by under modification. In addition, the optimal profile modification required to minimize the dynamic load (hence the contact stress) on a gear tooth differs from the optimal modification required to minimize the dynamic root (bending) stress. Computer simulation can help find the design tradeoffs to determine the best profile modification to satisfy the conflicting constraints of minimizing both the load and root stress in gears which must operate over a range of applied loads.