Journal articles on the topic 'Noninvasive matrice'
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Yu, Hong Xia, and Chuang Li. "Nonintrusive Efficiency Estimation of Induction Motors Based on an Adaptive Extended Kalman Filter." Applied Mechanics and Materials 446-447 (November 2013): 698–703. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.698.
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In this paper, a new nonintrusive efficiency estimation method without using stray loss approximation value was presented, the efficiency of induction motor was computed using estimated value of speed and load torque by AEKF. In AEKF, the speed and load torque as the state of system are estimated, the noise covariance matrices are estimated adaptively while the state of induction motor system are estimated to overcome the defect that estimation results are affected by the selected noise covariance matrices in EKF, then the estimated speed and the load torque are used to achieve noninvasive efficiency estimation. Experimental results demonstrate that the efficiency estimation results of this method has higher accuracy and are not affected by initial value of noises covariance matrices.
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Pfeifer, B., M. Seger, C. Hintermüller, F. Hanser, R. Modre, B. Tilg, T. Trieb, et al. "Computationally Efficient Noninvasive Cardiac Activation Time Imaging." Methods of Information in Medicine 44, no. 05 (2005): 674–86. http://dx.doi.org/10.1055/s-0038-1634024.
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Summary Objective: The computer model-based computation of the cardiac activation sequence in humans has been recently subject of successful clinical validation. This method is of potential interest for guiding ablation therapy of arrhythmogenic substrates. However, computation times of almost an hour are unattractive in a clinical setting. Thus, the objective is the development of a method which performs the computation in a few minutes run time. Methods: The computationally most expensive part is the product of the lead field matrix with a matrix containing the source pattern on the cardiac surface. The particular biophysical properties of both matrices are used for speeding up this operation by more than an order of magnitude. A conjugate gradient optimizer was developed using C++ for computing the activation map. Results: The software was tested on synthetic and clinical data. The increase in speed with respect to the previously used Fortran 77 implementation was a factor of 30 at a comparable quality of the results. As an additional finding the coupled regularization strategy, originally introduced for saving computation time, also reduced the sensitivity of the method to the choice of the regularization parameter. Conclusions: As it was shown for data from a WPW-patient the developed software can deliver diagnostically valuable information at a much shorter span of time than current clinical routine methods. Its main application could be the localization of focal arrhythmogenic substrates.
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Oleszko-Torbus, Natalia, Marcelina Bochenek, Alicja Utrata-Wesołek, Agnieszka Kowalczuk, Andrzej Marcinkowski, Andrzej Dworak, Agnieszka Fus-Kujawa, Aleksander L. Sieroń, and Wojciech Wałach. "Poly(2-oxazoline) Matrices with Temperature-Dependent Solubility—Interactions with Water and Use for Cell Culture." Materials 13, no. 12 (June 13, 2020): 2702. http://dx.doi.org/10.3390/ma13122702.
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In this work, we studied the stability of matrices with temperature-dependent solubility and their interactions with water at physiological temperature for their application in cell culture in vitro. Gradient copolymers of 2-isopropyl- with 2-n-propyl-2-oxazoline (P(iPrOx-nPrOx)) were used to prepare the matrices. The comonomer ratio during polymerization was chosen such that the cloud point temperature (TCP) of the copolymer was below 37 °C while the glass transition (Tg) was above 37 °C. The role of the support for matrices in the context of their stability in aqueous solution was examined. Therefore, matrices in the form of both self-supported bulk polymer materials (fibrillar mats and molds) and polymer films supported on the silica slides were examined. All of the matrices remained undissolved when incubated in water at a temperature above TCP. For the self-supported mats and molds, we observed the loss of shape stability, but, in the case of films supported on silica slides, only slight changes in morphology were observed. For a more in-depth investigation of the origin of the shape deformation of self-supported matrices, we analyzed the wettability, thickness, and water uptake of films on silica support because the matrices remained undeformed under these conditions. It was found that, above the TCP of P(iPrOx-nPrOx), the wettability of the films decreased, but at the same time the films absorbed water and swelled. We examined how this specific behavior of the supported films influenced the culture of fibroblasts. The temperature-dependent solubility of the matrices and the possibility of noninvasive cell separation were also examined.
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Tickle, Jacqueline A., Harish Poptani, Arthur Taylor, and Divya M. Chari. "Noninvasive imaging of nanoparticle-labeled transplant populations within polymer matrices for neural cell therapy." Nanomedicine 13, no. 11 (June 2018): 1333–48. http://dx.doi.org/10.2217/nnm-2017-0347.
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Lin, Shuyu, Wenzhuo Yu, Bo Wang, Yichao Zhao, Ke En, Jialun Zhu, Xuanbing Cheng, et al. "Noninvasive wearable electroactive pharmaceutical monitoring for personalized therapeutics." Proceedings of the National Academy of Sciences 117, no. 32 (July 27, 2020): 19017–25. http://dx.doi.org/10.1073/pnas.2009979117.
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To achieve the mission of personalized medicine, centering on delivering the right drug to the right patient at the right dose, therapeutic drug monitoring solutions are necessary. In that regard, wearable biosensing technologies, capable of tracking drug pharmacokinetics in noninvasively retrievable biofluids (e.g., sweat), play a critical role, because they can be deployed at a large scale to monitor the individuals’ drug transcourse profiles (semi)continuously and longitudinally. To this end, voltammetry-based sensing modalities are suitable, as in principle they can detect and quantify electroactive drugs on the basis of the target’s redox signature. However, the target’s redox signature in complex biofluid matrices can be confounded by the immediate biofouling effects and distorted/buried by the interfering voltammetric responses of endogenous electroactive species. Here, we devise a wearable voltammetric sensor development strategy—centering on engineering the molecule–surface interactions—to simultaneously mitigate biofouling and create an “undistorted potential window” within which the target drug’s voltammetric response is dominant and interference is eliminated. To inform its clinical utility, our strategy was adopted to track the temporal profile of circulating acetaminophen (a widely used analgesic and antipyretic) in saliva and sweat, using a surface-modified boron-doped diamond sensing interface (cross-validated with laboratory-based assays,R2∼ 0.94). Through integration of the engineered sensing interface within a custom-developed smartwatch, and augmentation with a dedicated analytical framework (for redox peak extraction), we realized a wearable solution to seamlessly render drug readouts with minute-level temporal resolution. Leveraging this solution, we demonstrated the pharmacokinetic correlation and significance of sweat readings.
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Turlewicz-Podbielska, Hanna, Jan Włodarek, and Małgorzata Pomorska-Mól. "Noninvasive strategies for surveillance of swine viral diseases: a review." Journal of Veterinary Diagnostic Investigation 32, no. 4 (July 2020): 503–12. http://dx.doi.org/10.1177/1040638720936616.
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In view of the intensive development of the swine industry, monitoring and surveillance of infectious diseases require low-cost, effective, and representative population sampling methods. We present herein the state of knowledge, to date, in the use of alternative strategies in the monitoring of swine health. Blood sampling, the most commonly used method in veterinary medicine to obtain samples for monitoring swine health, is labor-intensive and expensive, which has resulted in a search for alternative sampling strategies. Oral fluid (OF) is a good alternative to serum for pooled sample analysis, especially for low-prevalence pathogens. Detection of viral nucleic acids or antiviral antibodies in OF is used to detect numerous viruses in the swine population. Meat juice is used as an alternative to serum in serologic testing. Processing fluid obtained during processing of piglets (castration and tail-docking) may also be used to detect viruses. These matrices are simple, safe, cost-effective, and allow testing of many individuals at the same time. The latest methods, such as snout swabs and udder skin wipes, are also promising. These alternative samples are easy to acquire, and do not affect animal welfare negatively.
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Artioli, Gilberto, and Daniel S. Hussey. "Imaging with Neutrons." Elements 17, no. 3 (June 1, 2021): 189–94. http://dx.doi.org/10.2138/gselements.17.3.189.
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By exploiting the penetration, attenuation, and scattering properties of neutrons, images of matter in two or three dimensions reveal information unobtainable using other probes. Despite the limitation in brilliance of neutron sources, several neutron-based imaging techniques are essential to different aspects of modern geoscience. Typical examples include the evaluation of porosity in rocks and sediments, mapping of light elements in solids, noninvasive probing of cultural heritage objects, investigations of thick engineering components, and the exploration of diffusion and percolation processes of fluids within porous matrices, organo-inorganic composites, and living organisms. Techniques under development include simultaneous neutron and X-ray tomography in heterogeneous media, Bragg-edge imaging, and the possibility of porosimetry from dark-field imaging.
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Mitrea, Delia, Paulina Mitrea, Sergiu Nedevschi, Radu Badea, Monica Lupsor, Mihai Socaciu, Adela Golea, Claudia Hagiu, and Lidia Ciobanu. "Abdominal Tumor Characterization and Recognition Using Superior-Order Cooccurrence Matrices, Based on Ultrasound Images." Computational and Mathematical Methods in Medicine 2012 (2012): 1–17. http://dx.doi.org/10.1155/2012/348135.
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The noninvasive diagnosis of the malignant tumors is an important issue in research nowadays. Our purpose is to elaborate computerized, texture-based methods for performing computer-aided characterization and automatic diagnosis of these tumors, using only the information from ultrasound images. In this paper, we considered some of the most frequent abdominal malignant tumors: the hepatocellular carcinoma and the colonic tumors. We compared these structures with the benign tumors and with other visually similar diseases. Besides the textural features that proved in our previous research to be useful in the characterization and recognition of the malignant tumors, we improved our method by using the grey level cooccurrence matrix and the edge orientation cooccurrence matrix of superior order. As resulted from our experiments, the new textural features increased the malignant tumor classification performance, also revealing visual and physical properties of these structures that emphasized the complex, chaotic structure of the corresponding tissue.
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Lamoureux, M. M., J. C. Hutton, D. L. Styris, and R. L. Gordon. "Noninvasive Quantitative Chromium(III) Speciation in Neat Solid Mixtures by Extended X-ray Absorption Fine Structure Spectroscopy." Applied Spectroscopy 49, no. 6 (June 1995): 808–12. http://dx.doi.org/10.1366/0003702953964471.
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A procedure that uses extended X-ray absorption fine structure (EXAFS) spectroscopy for quantitative chromium(III) speciation in neat solid mixtures is described. The procedure uses the full, filtered EXAFS, e.g., 4 ≤ k ≤ 12 Å−1, rather than the smaller k-range associated with a single coordination sphere. Concentration is determined by a simple correlation of full, filtered EXAFS of standards with full, filtered EXAFS of mixtures. Under optimized conditions, calibration curves for mixtures of Cr2O3 and Cr(NO3)3·9H2O have slopes of 1.002, respective intercepts of −0.7% and 0.5%, and correlation coefficients of 0.9991. Fluorescence EXAFS from mixtures must be compared to fluorescence EXAFS from standards, and the matrices and thicknesses of standards and mixtures must be closely matched. Transmission EXAFS of standards must be obtained to correct for self-absorption effects.
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Vivaldi, F., A. Dallinger, N. Poma, A. Bonini, D. Biagini, P. Salvo, F. Borghi, A. Tavanti, F. Greco, and F. Di Francesco. "Sweat analysis with a wearable sensing platform based on laser-induced graphene." APL Bioengineering 6, no. 3 (September 1, 2022): 036104. http://dx.doi.org/10.1063/5.0093301.
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The scientific community has shown increasing interest in laser scribing for the direct fabrication of conductive graphene-based tracks on different substrates. This can enable novel routes for the noninvasive analysis of biofluids (such as sweat or other noninvasive matrices), whose results can provide the rapid evaluation of a person's health status. Here, we present a wearable sensing platform based on laser induced graphene (LIG) porous electrodes scribed on a flexible polyimide sheet, which samples sweat through a paper sampler. The device is fully laser manufactured and features a two layer design with LIG-based vertical interconnect accesses. A detailed characterization of the LIG electrodes including pore size, surface groups, surface area in comparison to electroactive surface area, and the reduction behavior of different LIG types was performed. The bare LIG electrodes can detect the electrochemical oxidation of both uric acid and tyrosine. Further modification of the surface of the LIG working electrode with an indoaniline derivative [4-((4-aminophenyl)imino)-2,6-dimethoxycyclohexa-2,5-dien-1-one] enables the voltammetric measurement of pH with an almost ideal sensitivity and without interference from other analytes. Finally, electrochemical impedance spectroscopy was used to measure the concentrations of ions through the analysis of the sweat impedance. The device was successfully tested in a real case scenario, worn on the skin during a sports session. In vitro tests proved the non-cytotoxic effect of the device on the A549 cell line.
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Hosseinian, Hamed, Samira Hosseini, Sergio O. Martinez-Chapa, and Mazhar Sher. "A Meta-Analysis of Wearable Contact Lenses for Medical Applications: Role of Electrospun Fiber for Drug Delivery." Polymers 14, no. 1 (January 3, 2022): 185. http://dx.doi.org/10.3390/polym14010185.
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In recent years, wearable contact lenses for medical applications have attracted significant attention, as they enable continuous real-time recording of physiological information via active and noninvasive measurements. These devices play a vital role in continuous monitoring of intraocular pressure (IOP), noninvasive glucose monitoring in diabetes patients, drug delivery for the treatment of ocular illnesses, and colorblindness treatment. In specific, this class of medical devices is rapidly advancing in the area of drug loading and ocular drug release through incorporation of electrospun fibers. The electrospun fiber matrices offer a high surface area, controlled morphology, wettability, biocompatibility, and tunable porosity, which are highly desirable for controlled drug release. This article provides an overview of the advances of contact lens devices in medical applications with a focus on four main applications of these soft wearable devices: (i) IOP measurement and monitoring, (ii) glucose detection, (iii) ocular drug delivery, and (iv) colorblindness treatment. For each category and application, significant challenges and shortcomings of the current devices are thoroughly discussed, and new areas of opportunity are suggested. We also emphasize the role of electrospun fibers, their fabrication methods along with their characteristics, and the integration of diverse fiber types within the structure of the wearable contact lenses for efficient drug loading, in addition to controlled and sustained drug release. This review article also presents relevant statistics on the evolution of medical contact lenses over the last two decades, their strengths, and the future avenues for making the essential transition from clinical trials to real-world applications.
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Han, Alice A., Charles Timchalk, Zana A. Carver, Thomas J. Weber, Kimberly J. Tyrrell, Ryan L. Sontag, Teresa Gibbins, et al. "Physiologically Based Pharmacokinetic Modeling of Salivary Concentrations for Noninvasive Biomonitoring of 2,4-Dichlorophenoxyacetic Acid (2,4-D)." Toxicological Sciences 172, no. 2 (September 21, 2019): 330–43. http://dx.doi.org/10.1093/toxsci/kfz206.
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Abstract Saliva has become a favorable sample matrix for biomonitoring due to its noninvasive attributes and overall flexibility in collection. To ensure measured salivary concentrations reflect the exposure, a solid understanding of the salivary transport mechanism and relationships between salivary concentrations and other monitored matrices (ie, blood, urine) is needed. Salivary transport of a commonly applied herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), was observed in vitro and in vivo and a physiologically based pharmacokinetic (PBPK) model was developed to translate observations from the cell culture model to those in animal models and further evaluate 2,4-D kinetics in humans. Although apparent differences in experimental in vitro and in vivo saliva:plasma ratios (0.034 and 0.0079) were observed, simulations with the PBPK model demonstrated dynamic time and dose-dependent saliva:plasma ratios, elucidating key mechanisms affecting salivary transport. The model suggested that 2,4-D exhibited diffusion-limited transport to saliva and was additionally impacted by protein binding saturation and permeability across the salivary gland. Consideration of sampling times post-exposure and potential saturation of transport mechanisms are then critical aspects for interpreting salivary 2,4-D biomonitoring observations. This work utilized PBPK modeling in in vitro to in vivo translation to explore benefits and limitations of salivary analysis for occupational biomonitoring.
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Goodilin, E. A., A. A. Semenova, O. E. Eremina, N. A. Brazhe, E. A. Goodilinа, T. Yu Danzanova, G. V. Maksimov, and I. A. Veselova. "Promising methods for noninvasive medical diagnosis based on the use of nanoparticles: surface-enhanced raman spectroscopy in the study of cells, cell organelles and neurotransmitter metabolism markers." NANOMEDICINE, no. 6 (December 30, 2018): 57–67. http://dx.doi.org/10.24075/brsmu.2018.077.
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Application of advances in nanomedicine and materials science to medical diagnostics is a promising area of research. Surface-enhanced Raman spectroscopy (SERS) is an innovative analytical method that exploits noble metal nanoparticles to noninvasively study cells, cell organelles and protein molecules. Below, we summarize the literature on the methods for early clinical diagnosis of some neurodegenerative and neuroendocrine diseases. We discuss the specifics, advantages and limitations of different diagnostic techniques based on the use of low- and high molecular weight biomarkers. We talk about the prospects of optical methods for rapid diagnosis of neurotransmitter metabolism disorders. Special attention is paid to new approaches to devising optical systems that expand the analytical potential of SERS, the tool that demonstrates remarkable sensitivity, selectivity and reproducibility of the results in determining target analytes in complex biological matrices.
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Veronesi, M. C., A. Comin, T. Meloni, M. Faustini, A. Rota, and A. Prandi. "Coat and claws as new matrices for noninvasive long-term cortisol assessment in dogs from birth up to 30 days of age." Theriogenology 84, no. 5 (September 2015): 791–96. http://dx.doi.org/10.1016/j.theriogenology.2015.05.013.
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Hayes, Taylor R., and Alexander A. Petrov. "Pupil Diameter Tracks the Exploration–Exploitation Trade-off during Analogical Reasoning and Explains Individual Differences in Fluid Intelligence." Journal of Cognitive Neuroscience 28, no. 2 (February 2016): 308–18. http://dx.doi.org/10.1162/jocn_a_00895.
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The ability to adaptively shift between exploration and exploitation control states is critical for optimizing behavioral performance. Converging evidence from primate electrophysiology and computational neural modeling has suggested that this ability may be mediated by the broad norepinephrine projections emanating from the locus coeruleus (LC) [Aston-Jones, G., & Cohen, J. D. An integrative theory of locus coeruleus-norepinephrine function: Adaptive gain and optimal performance. Annual Review of Neuroscience, 28, 403–450, 2005]. There is also evidence that pupil diameter covaries systematically with LC activity. Although imperfect and indirect, this link makes pupillometry a useful tool for studying the locus coeruleus norepinephrine system in humans and in high-level tasks. Here, we present a novel paradigm that examines how the pupillary response during exploration and exploitation covaries with individual differences in fluid intelligence during analogical reasoning on Raven's Advanced Progressive Matrices. Pupillometry was used as a noninvasive proxy for LC activity, and concurrent think-aloud verbal protocols were used to identify exploratory and exploitative solution periods. This novel combination of pupillometry and verbal protocols from 40 participants revealed a decrease in pupil diameter during exploitation and an increase during exploration. The temporal dynamics of the pupillary response was characterized by a steep increase during the transition to exploratory periods, sustained dilation for many seconds afterward, and followed by gradual return to baseline. Moreover, the individual differences in the relative magnitude of pupillary dilation accounted for 16% of the variance in Advanced Progressive Matrices scores. Assuming that pupil diameter is a valid index of LC activity, these results establish promising preliminary connections between the literature on locus coeruleus norepinephrine-mediated cognitive control and the literature on analogical reasoning and fluid intelligence.
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Colomban, Philippe, Burcu Kırmızı, Bing Zhao, Jean-Baptiste Clais, Yong Yang, and Vincent Droguet. "Investigation of the Pigments and Glassy Matrix of Painted Enamelled Qing Dynasty Chinese Porcelains by Noninvasive On-Site Raman Microspectrometry." Heritage 3, no. 3 (August 17, 2020): 915–40. http://dx.doi.org/10.3390/heritage3030050.
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A selection of 15 Chinese painted enameled porcelains from the 18th century (Qing dynasty) was analyzed on-site by mobile Raman and XRF microspectroscopy. The highly prized artifacts are present in the collections of the Musée du Louvre in Paris and Musée Chinois at Fontainebleau Castle in France. In the painted enamels, pigments such as Naples yellow lead pyrochlore, hematite, manganese oxide and carbon and opacifiers such as lead arsenates were detected. The glassy matrices of the enamels mainly belonged to lead-rich and lead-alkali glass types according to the Raman spectra obtained. The glaze and body phases of the porcelain artifacts were also analyzed. The detection of lead arsenate apatite in some of the blue enamels was significant, indicating the use of arsenic-rich European cobalt ores (smalt) and possibly mixing with Asian cobalt. This characteristic phase has also been identified in French soft-paste porcelains and glass decor and high-quality Limoges enamels from the same period. Based on the shape of the Raman scattering background, the presence of colloidal gold (Au° nanoparticles) was identified in red, orange and pink enamels. Different types of Naples yellow pigments were also detected with Sb-rich, Sn-rich and mixed Sb–Sn–(Zn, Fe?) compositions in the yellow enamels. The results were compared to previous data obtained on Chinese cloisonné and painted enameled metalware and Limoges enamels as well as French enameled watches.
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Mathejczyk, Julia Eva, Jutta Pauli, Christian Dullin, Joanna Napp, Lutz-F. Tietze, Horst Kessler, Ute Resch-Genger, and Frauke Alves. "Spectroscopically Well-Characterized RGD Optical Probe as a Prerequisite for Lifetime-Gated Tumor Imaging." Molecular Imaging 10, no. 6 (November 1, 2011): 7290.2011.00018. http://dx.doi.org/10.2310/7290.2011.00018.
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Labeling of RGD peptides with near-infrared fluorophores yields optical probes for noninvasive imaging of tumors overexpressing αvβ3 integrins. An important prerequisite for optimum detection sensitivity in vivo is strongly absorbing and highly emissive probes with a known fluorescence lifetime. The RGD-Cy5.5 optical probe was derived by coupling Cy5.5 to a cyclic arginine–glycine–aspartic acid–d-phenylalanine–lysine (RGDfK) peptide via an aminohexanoic acid spacer. Spectroscopic properties of the probe were studied in different matrices in comparison to Cy5.5. For in vivo imaging, human glioblastoma cells were subcutaneously implanted into nude mice, and in vivo fluorescence intensity and lifetime were measured. The fluorescence quantum yield and lifetime of Cy5.5 were found to be barely affected on RGD conjugation but dramatically changed in the presence of proteins. By time domain fluorescence imaging, we demonstrated specific binding of RGD-Cy5.5 to glioblastoma xenografts in nude mice. Discrimination of unspecific fluorescence by lifetime-gated analysis further enhanced the detection sensitivity of RGD-Cy5.5-derived signals. We characterized RGD-Cy5.5 as a strongly emissive and stable probe adequate for selective targeting of αvβ3 integrins. The specificity and thus the overall detection sensitivity in vivo were optimized with lifetime gating, based on the previous determination of the probes fluorescence lifetime under application-relevant conditions.
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Mitrea, Delia-Alexandrina, Raluca Brehar, Sergiu Nedevschi, Monica Lupsor-Platon, Mihai Socaciu, and Radu Badea. "Hepatocellular Carcinoma Recognition from Ultrasound Images Using Combinations of Conventional and Deep Learning Techniques." Sensors 23, no. 5 (February 24, 2023): 2520. http://dx.doi.org/10.3390/s23052520.
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Hepatocellular Carcinoma (HCC) is the most frequent malignant liver tumor and the third cause of cancer-related deaths worldwide. For many years, the golden standard for HCC diagnosis has been the needle biopsy, which is invasive and carries risks. Computerized methods are due to achieve a noninvasive, accurate HCC detection process based on medical images. We developed image analysis and recognition methods to perform automatic and computer-aided diagnosis of HCC. Conventional approaches that combined advanced texture analysis, mainly based on Generalized Co-occurrence Matrices (GCM) with traditional classifiers, as well as deep learning approaches based on Convolutional Neural Networks (CNN) and Stacked Denoising Autoencoders (SAE), were involved in our research. The best accuracy of 91% was achieved for B-mode ultrasound images through CNN by our research group. In this work, we combined the classical approaches with CNN techniques, within B-mode ultrasound images. The combination was performed at the classifier level. The CNN features obtained at the output of various convolution layers were combined with powerful textural features, then supervised classifiers were employed. The experiments were conducted on two datasets, acquired with different ultrasound machines. The best performance, above 98%, overpassed our previous results, as well as representative state-of-the-art results.
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Paleczek, Anna, and Artur Rydosz. "Review of the algorithms used in exhaled breath analysis for the detection of diabetes." Journal of Breath Research 16, no. 2 (January 26, 2022): 026003. http://dx.doi.org/10.1088/1752-7163/ac4916.
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Abstract Currently, intensive work is underway on the development of truly noninvasive medical diagnostic systems, including respiratory analysers based on the detection of biomarkers of several diseases including diabetes. In terms of diabetes, acetone is considered as a one of the potential biomarker, although is not the single one. Therefore, the selective detection is crucial. Most often, the analysers of exhaled breath are based on the utilization of several commercially available gas sensors or on specially designed and manufactured gas sensors to obtain the highest selectivity and sensitivity to diabetes biomarkers present in the exhaled air. An important part of each system are the algorithms that are trained to detect diabetes based on data obtained from sensor matrices. The prepared review of the literature showed that there are many limitations in the development of the versatile breath analyser, such as high metabolic variability between patients, but the results obtained by researchers using the algorithms described in this paper are very promising and most of them achieve over 90% accuracy in the detection of diabetes in exhaled air. This paper summarizes the results using various measurement systems, feature extraction and feature selection methods as well as algorithms such as support vector machines, k-nearest neighbours and various variations of neural networks for the detection of diabetes in patient samples and simulated artificial breath samples.
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Heinemann, Matthias, Holger Meinberg, Jochen Büchs, Hans-Jürgen Koß, and Marion B. Ansorge-Schumacher. "Method for Quantitative Determination of Spatial Polymer Distribution in Alginate Beads Using Raman Spectroscopy." Applied Spectroscopy 59, no. 3 (March 2005): 280–85. http://dx.doi.org/10.1366/0003702053585363.
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A new method based on Raman spectroscopy is presented for noninvasive, quantitative determination of the spatial polymer distribution in alginate beads of approximately 4 mm diameter. With the experimental setup, a two-dimensional image is created along a thin measuring line through the bead comprising one spatial and one spectral dimension. For quantitative analysis of the Raman spectra, the method of indirect hard modeling was applied to make use of the information contained in the entire recorded spectra. For quantification of the alginate signals from within the beads, a calibration curve acquired from sodium alginate solutions was used after it was shown that only negligible differences occur between signals from alginate solutions and alginate gels. The distribution of alginate over the bead gel matrix was acquired with high spatial (51 μm) and time (12 s) resolution. The inhomogeneous distribution obtained using the new measuring technique is qualitatively in excellent agreement with data from the literature. In contrast to known measuring techniques, correct quantitative information about the spatial polymer distribution within the matrix was derived. It gave an alginate mass fraction of approximately 0.045 g/g at the edges and 0.02 g/g in the center of the beads. Next to the determination of mere polymer concentrations, the excellent time resolution of the presented method will enable investigation of the dynamic process of gel formation and it will also serve as a basis for investigation of mass transfer of small diffusing molecules in alginate matrices.
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Anizan, Sebastien, and Marilyn A. Huestis. "The Potential Role of Oral Fluid in Antidoping Testing." Clinical Chemistry 60, no. 2 (February 1, 2014): 307–22. http://dx.doi.org/10.1373/clinchem.2013.209676.
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Abstract BACKGROUND Currently, urine and blood are the only matrices authorized for antidoping testing by the World Anti-Doping Agency (WADA). Although the usefulness of urine and blood is proven, issues remain for monitoring some drug classes and for drugs prohibited only in competition. The alternative matrix oral fluid (OF) may offer solutions to some of these issues. OF collection is easy, noninvasive, and sex neutral and is directly observed, limiting potential adulteration, a major problem for urine testing. OF is used to monitor drug intake in workplace, clinical toxicology, criminal justice, and driving under the influence of drugs programs and potentially could complement urine and blood for antidoping testing in sports. CONTENT This review outlines the present state of knowledge and the advantages and limitations of OF testing for each of the WADA drug classes and the research needed to advance OF testing as a viable alternative for antidoping testing. SUMMARY Doping agents are either prohibited at all times or prohibited in competition only. Few OF data from controlled drug administration studies are available for substances banned at all times, whereas for some agents prohibited only in competition, sufficient data may be available to suggest appropriate analytes and cutoffs (analytical threshold concentrations) to identify recent drug use. Additional research is needed to characterize the disposition of many banned substances into OF; OF collection methods and doping agent stability in OF also require investigation to allow the accurate interpretation of OF tests for antidoping monitoring.
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Fisher, S. J., T. Y. Cui, L. Zhang, L. Hartman, K. Grahl, G. Y. Zhang, J. Tarpey, and C. H. Damsky. "Adhesive and degradative properties of human placental cytotrophoblast cells in vitro." Journal of Cell Biology 109, no. 2 (August 1, 1989): 891–902. http://dx.doi.org/10.1083/jcb.109.2.891.
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Human fetal development depends on the embryo rapidly gaining access to the maternal circulation. The trophoblast cells that form the fetal portion of the human placenta have solved this problem by transiently exhibiting certain tumor-like properties. Thus, during early pregnancy fetal cytotrophoblast cells invade the uterus and its arterial network. This process peaks during the twelfth week of pregnancy and declines rapidly thereafter, suggesting that the highly specialized, invasive behavior of the cytotrophoblast cells is closely regulated. Since little is known about the actual mechanisms involved, we developed an isolation procedure for cytotrophoblasts from placentas of different gestational ages to study their adhesive and invasive properties in vitro. Cytotrophoblasts isolated from first, second, and third trimester human placentas were plated on the basement membrane-like extracellular matrix produced by the PF HR9 teratocarcinoma cell line. Cells from all trimesters expressed the calcium-dependent cell adhesion molecule cell-CAM 120/80 (E-cadherin) which, in the placenta, is specific for cytotrophoblasts. However, only the first trimester cytotrophoblast cells degraded the matrices on which they were cultured, leaving large gaps in the basement membrane substrates and releasing low molecular mass 3H-labeled matrix components into the medium. No similar degradative activity was observed when second or third trimester cytotrophoblast cells, first trimester human placental fibroblasts, or the human choriocarcinoma cell lines BeWo and JAR were cultured on radiolabeled matrices. To begin to understand the biochemical basis of this degradative behavior, the substrate gel technique was used to analyze the cell-associated and secreted proteinase activities expressed by early, mid, and late gestation cytotrophoblasts. Several gelatin-degrading proteinases were uniquely expressed by early gestation, invasive cytotrophoblasts, and all these activities could be abolished by inhibitors of metalloproteinases. By early second trimester, the time when cytotrophoblast invasion rapidly diminishes in vivo, the proteinase pattern of the cytotrophoblasts was identical to that of term, noninvasive cells. These results are the first evidence suggesting that specialized, temporally regulated metalloproteinases are involved in trophoblast invasion of the uterus. Since the cytotrophoblasts from first trimester and later gestation placentas maintain for several days the temporally regulated degradative behavior displayed in vivo, the short-term cytotrophoblast outgrowth culture system described here should be useful in studying some of the early events in human placen
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Duarte, Nilo J. C., Léonard V. K. Kupa, Julio C. R. Ferreira-Filho, Nicole Fontoura, Marc Y. Chalom, Paschoalina Romano, Pérsio A. R. Ebner, Clovis A. A. Silva, Valdemir M. Carvalho, and Eloisa Bonfá. "UHPLC-MS/MS Method for Determination of Hydroxychloroquine and Its Main Metabolites in Oral Fluid and Whole Blood for Therapeutic Drug Monitoring." Journal of Applied Laboratory Medicine 6, no. 4 (January 28, 2021): 868–80. http://dx.doi.org/10.1093/jalm/jfab031.
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Abstract Background Hydroxychloroquine (HCQ) blood levels are used to monitor efficacy, safety, and patient adherence during treatment. Oral fluid has emerged as an alternative noninvasive, easily accessible, and low-complexity matrix for drug monitoring. However, there is no analytical method to measure HCQ in oral fluid. Therefore, we developed and validated an ultra-high-performance liquid chromatography-tandem mass (UHPLC-MS/MS) method for the measurement of HCQ and its main metabolites in oral fluid and compared to whole blood. Methods Ten microliters of matrices were used for sample preparation by protein precipitation with acetonitrile followed by online solid phase extraction. The validation process included assessment of lower limit of quantification, linearity, precision, recovery, matrix effect, interferences assessment, carryover, and sample dilution validation. Results The lower limit of quantification was 50 ng/mL for HCQ and metabolites in both oral fluid and whole blood. The calibration curve was linear from 50 to 2000 ng/mL (r2 = 0.999). The coefficient of variation for precision assay was 1.2% to 9.7% for intraday and 1.1% to 14.2% for interday for both HCQ and metabolites in oral fluid and whole blood samples at 150, 750, and 1250 ng/mL. The recovery was 85.3% to 118.5% for 150, 750, and 1250 ng/mL of HCQ and metabolites in both oral fluid and whole blood. Dilution factor up to 5-fold was validated for concentrations higher than the upper limit of quantification. Conclusions The validated method is specific, precise, and accurate to determine the analytical range for therapeutic monitoring of HCQ and its main metabolites in oral fluid and blood.
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Meyer, Jerrold S., and Melinda A. Novak. "Minireview: Hair Cortisol: A Novel Biomarker of Hypothalamic-Pituitary-Adrenocortical Activity." Endocrinology 153, no. 9 (September 1, 2012): 4120–27. http://dx.doi.org/10.1210/en.2012-1226.
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Activity of the hypothalamic-pituitary-adrenocortical (HPA) axis is commonly assessed by measuring glucocorticoids such as cortisol (CORT). For many years, CORT was obtained primarily from blood plasma or urine, whereas later approaches added saliva and feces for noninvasive monitoring of HPA functioning. Despite the value of all these sample matrices for answering many research questions, they remain limited in the temporal range of assessment. Plasma and saliva are point samples that vary as a function of circadian rhythmicity and are susceptible to confounding by environmental disturbances. Even urine and feces generally assess HPA activity over a period of only 24 h or less. We and others have recently developed and validated methods for measuring the concentration of CORT in the body hair of animals (e.g. rhesus monkeys) and scalp hair of humans. CORT is constantly deposited in the growing hair shaft, as a consequence of which such deposition can serve as a biomarker of integrated HPA activity over weeks and months instead of minutes or hours. Since the advent of this methodological advance, hair CORT has already been used as an index of chronic HPA activity and stress in human clinical and nonclinical populations, in a variety of laboratory-housed and wild-living animal species, and in archival specimens that are many decades or even centuries old. Moreover, because human hair is known to grow at an average rate of about 1 cm/month, several studies suggest that CORT levels in hair segments that differ in proximity to the scalp can, under certain conditions, be used as a retrospective calendar of HPA activity during specific time periods preceding sample collection.
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Geaghan, Sharon M. "Fetal Laboratory Medicine: On the Frontier of Maternal–Fetal Medicine." Clinical Chemistry 58, no. 2 (February 1, 2012): 337–52. http://dx.doi.org/10.1373/clinchem.2011.166991.
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Abstract BACKGROUND Emerging antenatal interventions and care delivery to the fetus require diagnostic support, including laboratory technologies, appropriate methodologies, establishment of special algorithms, and interpretative guidelines for clinical decision-making. CONTENT Fetal diagnostic and therapeutic interventions vary in invasiveness and are associated with a spectrum of risks and benefits. Fetal laboratory assessments are well served by miniaturized diagnostic methods for blood analysis. Expedited turnaround times are mandatory to support invasive interventions such as cordocentesis and intrauterine transfusions. Health-associated reference intervals are required for fetal test interpretation. Fetal blood sampling by cordocentesis carries substantial risk and is therefore performed only when fetal health is impaired, or at risk. When the suspected pathology is not confirmed, however, normative fetal data can be collected. Strategies for assurance of sample integrity from cordocenteses and confirmation of fetal origin are described. After birth, definitive assessment of prenatal environmental and/or drug exposures to the fetus can be retrospectively assessed by analysis of meconium, hair, and other alternative matrices. A rapidly advancing technology for fetal assessment is the use of fetal laboratory diagnostic techniques that use cell-free fetal DNA collected from maternal plasma, and genetic analysis based on molecular counting techniques. SUMMARY Developmental changes in fetal biochemical and hematologic parameters in health and disease are continually delineated by analysis of our collective outcome-based experience. Noninvasive technologies for fetal evaluation are realizing the promise of lower risk yet robust diagnostics; examples include sampling and analysis of free fetal DNA from maternal blood, and analysis of fetal products accessible at maternal sites. Application of diagnostic technologies for nonmedical purposes (e.g., sex selection) underscores the importance of ethical guidelines for new technology implementation.
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Bolhuis, M. S., R. van Altena, K. van Hateren, W. C. M. de Lange, B. Greijdanus, D. R. A. Uges, J. G. W. Kosterink, T. S. van der Werf, and J. W. C. Alffenaar. "Clinical Validation of the Analysis of Linezolid and Clarithromycin in Oral Fluid of Patients with Multidrug-Resistant Tuberculosis." Antimicrobial Agents and Chemotherapy 57, no. 8 (May 20, 2013): 3676–80. http://dx.doi.org/10.1128/aac.00558-13.
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ABSTRACTLinezolid plays an increasingly important role in the treatment of multidrug-resistant tuberculosis (MDR-TB). However, patients should be carefully monitored due to time- and dose-dependent toxicity. Clarithromycin plays a more modest role. Therapeutic drug monitoring may contribute to assessment of treatment regimens, helping to reduce toxicity while maintaining adequate drug exposure. Oral fluid sampling could provide a welcome alternative in cases where conventional plasma sampling is not possible or desirable. The aim of this study was to clinically validate the analysis of linezolid and clarithromycin and its metabolite hydroxyclarithromycin in oral fluid of patients with multidrug-resistant tuberculosis. Serum and oral fluid samples were simultaneously obtained and analyzed by using validated methods, after extensive cross-validation between the two matrices. Passing-Bablok regressions and Bland-Altman analysis showed that oral fluid analysis of linezolid and clarithromycin appeared to be suitable for therapeutic drug monitoring in MDR-TB patients. No correction factor is needed for the interpretation of linezolid oral fluid concentrations with a ratio of the linezolid concentration in serum to that in oral fluid of 0.97 (95% confidence interval [CI], 0.92 to 1.02). However, the clarithromycin concentration serum/clarithromycin concentration in oral fluid ratio is 3.07 (95% CI, 2.45 to 3.69). Analysis of hydroxyclarithromycin in oral fluid was not possible in this study due to a nonlinear relationship between the concentration in serum and that in oral fluid. In conclusion, the analysis of linezolid (no correction factor) and clarithromycin (correction factor of 3) in oral fluid is applicable for therapeutic drug monitoring in cases of multidrug-resistant tuberculosis as an alternative to conventional serum sampling. Easy sampling using a noninvasive technique may facilitate therapeutic drug monitoring for specific patient categories.
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Paschoal, André Monteiro, Fernando Fernandes Paiva, and Renata Ferranti Leoni. "Dual-Echo Arterial Spin Labeling for Brain Perfusion Quantification and Functional Analysis." Concepts in Magnetic Resonance Part A 2019 (August 1, 2019): 1–7. http://dx.doi.org/10.1155/2019/5040465.
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Arterial Spin Labeling (ASL) is a noninvasive MRI-based method to measure cerebral blood flow (CBF). Recently, the study of ASL as a functional tool has emerged once CBF fluctuation comes from capillaries in brain tissue, giving a more spatially specific response when compared to the standard functional MRI method, based on the blood oxygenation level-dependent (BOLD) contrast. Although the BOLD effect could be desirable to study brain function, if one aims to quantify CBF, such effect is considered contamination that can be more attenuated if short TE value is used in the image acquisition. An approach that provides both CBF and function information in a simultaneous acquisition is the use of a dual-echo ASL (DE-ASL) readout. Our purpose was to evaluate the information provided by DE-ASL regarding CBF quantification and functional connectivity with a motor task. Pseudocontinuous ASL of twenty healthy subjects (age: 32.4 ± 10.2 years, 13 male) was acquired at a 3T scanner. We analyzed the influence of TE on CBF values and brain connectivity provided by CBF and concurrent BOLD (cc-BOLD) time series. Brain networks were obtained by the general linear model and independent component analysis. Connectivity matrices were generated using a bivariate correlation (Fisher Z values). No effect of the sequence readout, but significant effect of the TE value, was observed on gray matter CBF values. Motor networks with reduced extension and more connections with important regions for brain integration were observed for CBF data acquired with short TE, proving its higher spatial specificity. Therefore, it was possible to use a dual-echo readout provided by a standard commercial ASL pulse sequence to obtain reliable quantitative CBF values and functional information simultaneously.
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Dressler, Franz F., Christian Gratzke, Arkadiusz Miernik, and Dominik S. Schoeb. "Track and Teach: Identifying Key Movement Patterns in Endoscopic Transurethral Enucleation of the Prostate." Urologia Internationalis 105, no. 9-10 (2021): 835–45. http://dx.doi.org/10.1159/000514596.
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<b><i>Purpose:</i></b> We evaluated a system for noninvasive quantitative motion tracking to recognize differences in the movement pattern of experienced surgeons and beginners. Since performing endoscopic procedures requires extensive training, and tissue damage due to disruptive movements with sudden acceleration is possible, the learning curve for beginners is of clinical relevance. Steepening this curve may improve patient outcome. <b><i>Materials and Methods:</i></b> We used a commercial gyroscope sensor with a wireless data link, which was attached to the resectoscope handle (RH). After recording, orientation was retrieved by application of the calculated rotation matrices to the RH vector relative to the sensor under the boundary condition of rotational movement around and quasi-constant distance to the pivot point at pelvic floor level. Data alignment, normalization, interpolation, and analysis were performed in custom software scripts. <b><i>Results:</i></b> Experienced surgeons and beginners were recorded in <i>n</i> = 36 and <i>n</i> = 14 holmium laser enucleation of the prostate (HoLEP), respectively. Prostate size, patient age, and recorded procedure duration were comparable. Mean lever angle of the individual normalized motion patterns was considerably lower (19.28 ± 0.54° [SEM]) in the advanced than in the beginners’ group (24.52 ± 1.00°; <i>p</i> = 0.0001). Further parameters such as velocity and motion variation demonstrated additional differences between both groups. <b><i>Conclusions:</i></b> We demonstrate the feasibility of motion tracking in HoLEP. Pronounced differences exist between different stages of surgeon experience with this procedure. The method can easily be adopted to aide young surgeons in resectoscope handling and identification of improvable motion patterns. Damage to the pelvic floor and surrounding tissue may thus be reduced.
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Hsieh, Yao-Te, Enzi Jiang, Carlton Scharman, Ella Waters, Eugene Park, Asha Kadavallore, Halvard Bonig, and Yong-Mi Kim. "Preclinical Evaluation of Tysabri as a Novel Adjuvant Therapy against Drug Resistant B-ALL." Blood 114, no. 22 (November 20, 2009): 3089. http://dx.doi.org/10.1182/blood.v114.22.3089.3089.
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Abstract Abstract 3089 Poster Board III-26 Novel treatment strategies for pediatric acute lymphoblastic leukemia (ALL) have turned a rapidly deadly diagnosis into a highly treatable entity, but we are still failing 25% of our pediatric ALL patients who die of recurrent ALL. Definitive studies have demonstrated that adhesion of leukemia and lymphoma cells to extracellular matrices or stromal cells protects them against the toxicity of cytoreductive chemotherapy drugs. In this context, a specific role for CD49d, a dominant adhesion molecule for normal lymphocytes, was demonstrated for acute myeloid leukemia (AML) and other malignant hematopoietic cells. The finding that CD49d blockade sensitizes AML cells to chemotoxicity may be of therapeutic potential, as is suggested by recent findings for AML cells engrafted in NOD/SCID mice. CD49d is and is similarly expressed on acute lymphoblastic leukemia (ALL) cells, but our knowledge about CD49d adhesion-mediated chemoprotection of B-ALL is limited. We hypothesized whether similar to primary AML blasts, xenografted ALL cells resistant to chemotherapy can be sensitized to chemotherapy by disrupting their CD49d-mediated adhesive interaction with stroma. To test our hypothesis we used as a CD49d inhibitor the humanized anti-human CD49d antibody natalizumab, or Tysabri®, which is in clinical use for the treatment of relapsing or refractory Multiple Sclerosis. To determine the potential of Tysabri as a single agent to decrease leukemia progression, we engrafted 5-7 weeks old NOD/SCID mice with primary drug resistant B-ALL labeled with lentiviral luciferase to allow monitoring of leukemia using noninvasive bioluminescent imaging. Tysabri administered upon detection of engraftment on Day15 post-injection of leukemia in the dose of either 1 mg (n=3) or 6 mg (n=3) led to remarkably slower leukemia progression regardless of the dose compared to the control group treated with saline only (n=2). Additional administration of Tysabri on day 29 and day 37 did not result in further containment of leukemogenesis but still showed a marked reduction in progression compared to the saline treated control group. In addition, we determined in vivo that a weekly administration of Tysabri in the dose of 5mg/kg/d resulted in prolonged survival compared to the treated control (p<0.05). Next, we assessed the effect of adjuvant anti-CD49d antibody-mediated dislodgement of ALL cells of drug resistant patients in combination with chemotherapy. The group treated for 4 weeks with chemotherapy including Vincristine, Dexamethasone and L-Asparaginase (VDL) in combination with Tysabri (5mg/kg/d) admistered once weekly showed decreased progression of leukemia and significantly prolonged survival (p<0.05) compared to the VDL only treated control group. No toxicity of Tysabri treatment was observed. Taken together, our data indicates the potential of Tysabri as a novel adjuvant therapy for treatment of drug resistant B-ALL. Given the availability of clinical-grade CD49d blocking antibody, clinical studies can follow immediately, should our hypothesis be confirmed in further in vitro an in vivo studies. Disclosures No relevant conflicts of interest to declare.
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Banerjee, Sudipta. "Estimation of Matrix Metalloproteinases and their Tissue Inhibitors in Urine to Ascertain Noninvasive tools for Detecting Prostate Cancer." Journal of Medical Science And clinical Research 6, no. 3 (March 18, 2018). http://dx.doi.org/10.18535/jmscr/v6i3.85.
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Lu, Yang, Qingqing Zhou, and Lin Xu. "Non-Invasive Electrochemical Biosensors for TNF-α Cytokines Detection in Body Fluids." Frontiers in Bioengineering and Biotechnology 9 (September 21, 2021). http://dx.doi.org/10.3389/fbioe.2021.701045.
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The measurement of pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-α), which is an important indicator of the inflammatory process, has received increasing attention recently because it is easy to extract from body fluid and serves as an early sign of a serious systemic inflammatory disease. Developing fast and simple detection methods to quantify the concentration of TNF-α is essential. Saliva, tears, and urine, which can easily be sampled in a non-invasive way, are considered to be important matrices for monitoring and assessing the physiological status of humans; importantly, they also provide an ideal window for monitoring the concentration of TNF-α. As a fast, accurate, inexpensive, portable, and scalable method, electrochemical biosensors are very promising for biomarker detection in matrices obtained in a non-invasive manner. This review summarises and compares the electrochemical biosensors for the detection of TNF-α in a non-invasive manner and highlights recent advances and future prospects in developing high-performance electrochemical platforms for noninvasive measurement of TNF-α.
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Lamichhane, Bidhan, Dinal Jayasekera, Rachel Jakes, Wilson Z. Ray, Eric C. Leuthardt, and Ammar H. Hawasli. "Functional Disruptions of the Brain in Low Back Pain: A Potential Imaging Biomarker of Functional Disability." Frontiers in Neurology 12 (July 14, 2021). http://dx.doi.org/10.3389/fneur.2021.669076.
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Chronic low back pain (LBP) is one of the leading causes of disability worldwide. While LBP research has largely focused on the spine, many studies have demonstrated a restructuring of human brain architecture accompanying LBP and other chronic pain states. Brain imaging presents a promising source for discovering noninvasive biomarkers that can improve diagnostic and prognostication outcomes for chronic LBP. This study evaluated graph theory measures derived from brain resting-state functional connectivity (rsFC) as prospective noninvasive biomarkers of LBP. We also proposed and tested a hybrid feature selection method (Enet-subset) that combines Elastic Net and an optimal subset selection method. We collected resting-state functional MRI scans from 24 LBP patients and 27 age-matched healthy controls (HC). We then derived graph-theoretical features and trained a support vector machine (SVM) to classify patient group. The degree centrality (DC), clustering coefficient (CC), and betweenness centrality (BC) were found to be significant predictors of patient group. We achieved an average classification accuracy of 83.1% (p < 0.004) and AUC of 0.937 (p < 0.002), respectively. Similarly, we achieved a sensitivity and specificity of 87.0 and 79.7%. The classification results from this study suggest that graph matrices derived from rsFC can be used as biomarkers of LBP. In addition, our findings suggest that the proposed feature selection method, Enet-subset, might act as a better technique to remove redundant variables and improve the performance of the machine learning classifier.
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Tiwari, Vipin, Yukti Pandey, and Nandan S. Bisht. "Spatially Addressable Polarimetric Calibration of Reflective-Type Spatial Light Modulator Using Mueller–Stokes Polarimetry." Frontiers in Physics 9 (August 12, 2021). http://dx.doi.org/10.3389/fphy.2021.709192.
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Mueller–Stokes polarimetry is emerging as a prominent noninvasive imaging technique to study the structural characteristics of an anisotropic medium. Spatial light modulator (SLM) is a programmable liquid crystal device (LCD), which is used to modulate the amplitude, phase, and polarization of light. The compact design and cumbrous manufacturing process of SLM requires its polarimetric calibration prior to its utilization for various applications. In this study, we experimentally demonstrate Mueller–Stokes imaging of a reflective-type SLM (Holoeye, LCR-720) to calibrate its polarization modulation characteristics with respect to its dynamic gray value range (0–255) at different spatial locations of SLM screen. Mueller matrices at 18 different gray values of SLM at an interval of 15, that is, at gray values 0, 15, 30, up to 255 have been experimentally measured using an improvised Mueller matrix imaging polarimeter (MMIP). Crucial polarimetric characteristics, that is, diattenuation, polarizance, state of polarization (SOP), depolarization, and retardance have been estimated with respect to the gray value range of SLM. Significant polarization modulation characteristics [diattenuation (0.08–0.3), polarizance (0.02–0.2), and retardance (0 to π)] have been determined for the SLM. These results indicate that the SLM exhibits spatially variable depolarizing nature and hence it is not perfectly homogeneous in structure. Therefore, it is expected that the outcomes of this study would be helpful for exploring the applicability of Mueller–Stokes polarimetry in advancement of LC technology.
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Ye, Fei, Jie Liang, Jiaoxing Li, Haiyan Li, and Wenli Sheng. "Development and Validation of a Five-Gene Signature to Predict Relapse-Free Survival in Multiple Sclerosis." Frontiers in Neurology 11 (December 3, 2020). http://dx.doi.org/10.3389/fneur.2020.579683.
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Background: Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system with a variable natural history of relapse and remission. Previous studies have found many differentially expressed genes (DEGs) in the peripheral blood of MS patients and healthy controls, but the value of these genes for predicting the risk of relapse remains elusive. Here we develop and validate an effective and noninvasive gene signature for predicting relapse-free survival (RFS) in MS patients.Methods: Gene expression matrices were downloaded from Gene Expression Omnibus and ArrayExpress. DEGs in MS patients and healthy controls were screened in an integrated analysis of seven data sets. Candidate genes from a combination of protein–protein interaction and weighted correlation network analysis were used to identify key genes related to RFS. An independent data set (GSE15245) was randomized into training and test groups. Univariate and least absolute shrinkage and selection operator–Cox regression analyses were used in the training group to develop a gene signature. A nomogram incorporating independent risk factors was developed via multivariate Cox regression analyses. Kaplan–Meier methods, receiver-operating characteristic (ROC) curves, and Harrell's concordance index (C-index) were used to estimate the performance of the gene signature and nomogram. The test group was used for external validation.Results: A five-gene signature comprising FTH1, GBP2, MYL6, NCOA4, and SRP9 was used to calculate risk scores to predict individual RFS. The risk score was an independent risk factor, and a nomogram incorporating clinical parameters was established. ROC curves and C-indices demonstrated great performance of these predictive tools in both the training and test groups.Conclusions: The five-gene signature may be a reliable tool for assisting physicians in predicting RFS in clinical practice. We anticipate that these findings could not only facilitate personalized treatment for MS patients but also provide insight into the complex molecular mechanism of this disease.
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Turanov, Sergei. "Development of a set of oligonucleotides for the identification of the Sakhalin sturgeon Acipenser mikadoi Hilgendorf, 1892 by PCR." ARPHA Conference Abstracts 4 (March 4, 2021). http://dx.doi.org/10.3897/aca.4.e65013.
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Sturgeons (family Acipenseridae) are valuable commercial fish and aquaculture resources. The Acipenser genus includes about 20 species, 12 of which are recorded for the Russian territory. One of the rarest is the Sakhalin sturgeon A. mikadoi Hilgendorf, 1892. At present, its population size is significantly decreased and the species is close to extinction. Natural populations of the species have survived in the Tumnin River in Khabarovsk Region and the Viakhtu River in Sakhalin Region. Vihtu River in Sakhalin Region. Due to the small numbers of rare and endangered fish species, noninvasive approaches, including the use of DNA from the environment, appear to be the most suitable for monitoring their species and genetic diversity. The method is well established in this area and has been successfully tested for the monitoring of several species of rare and endangered sturgeons. This paper presents the results of the development of primers specific for the mitochondrial DNA of the species A. mikadoi. A matrix of 15 sequences of complete mitochondrial genomes from 3 sturgeon species whose ranges may overlap - A. mikadoi (KX276658), A. dauricus (KJ402277) and A. schrenckii (MH973728- MH973734, KX276660, KX276659, KF150287, KC905169, KC820796) - was generated. A. medirostris (NC_028405), which is genetically closest to the Sakhalin sturgeon, was also included in the analysis. A sliding window algorithm was applied to the sequence matrix. A graph showing the distribution of divergence values along the mitochondrial genome of sturgeon was plotted based on the results of the analysis Fig. 1. Based on matrices of individual genome fragments (16S rRNA, COI, ND1, and D-loop), a search for species-specific primers was performed in the DECIPHER program. A Primer-BLAST algorithm was run based on each pair of primers. Taxa Actinopterygii and Acipenseridae were used as references separately in different runs. In addition, primers were checked using local reference sequences of the complete mitochondrial genome of representatives of the genus Acipenser. The results of primer evaluation are summarized in the table Table 1. As a result, a combination of primer pairs developed on the basis of D-loop and COI fragments seems to be the most successful for error-free identification of Sakhalin sturgeon.
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Xu, Aqiao, Xiufeng Chu, Shengjian Zhang, Jing Zheng, Dabao Shi, Shasha Lv, Feng Li, and Xiaobo Weng. "Prediction Breast Molecular Typing of Invasive Ductal Carcinoma Based on Dynamic Contrast Enhancement Magnetic Resonance Imaging Radiomics Characteristics: A Feasibility Study." Frontiers in Oncology 12 (May 19, 2022). http://dx.doi.org/10.3389/fonc.2022.799232.
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ObjectiveTo investigate the feasibility of radiomics in predicting molecular subtype of breast invasive ductal carcinoma (IDC) based on dynamic contrast enhancement magnetic resonance imaging (DCE-MRI).MethodsA total of 303 cases with pathologically confirmed IDC from January 2018 to March 2021 were enrolled in this study, including 223 cases from Fudan University Shanghai Cancer Center (training/test set) and 80 cases from Shaoxing Central Hospital (validation set). All the cases were classified as HR+/Luminal, HER2-enriched, and TNBC according to immunohistochemistry. DCE-MRI original images were treated by semi-automated segmentation to initially extract original and wavelet-transformed radiomic features. The extended logistic regression with least absolute shrinkage and selection operator (LASSO) penalty was applied to identify the optimal radiomic features, which were then used to establish predictive models combined with significant clinical risk factors. Receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis were adopted to evaluate the effectiveness and clinical benefit of the models established.ResultsOf the 223 cases from Fudan University Shanghai Cancer Center, HR+/Luminal cancers were diagnosed in 116 cases (52.02%), HER2-enriched in 71 cases (31.84%), and TNBC in 36 cases (16.14%). Based on the training set, 788 radiomic features were extracted in total and 8 optimal features were further identified, including 2 first-order features, 1 gray-level run length matrix (GLRLM), 4 gray-level co-occurrence matrices (GLCM), and 1 3D shape feature. Three multi-class classification models were constructed by extended logistic regression: clinical model (age, menopause, tumor location, Ki-67, histological grade, and lymph node metastasis), radiomic model, and combined model. The macro-average areas under the ROC curve (macro-AUC) for the three models were 0.71, 0.81, and 0.84 in the training set, 0.73, 0.81, and 0.84 in the test set, and 0.76, 0.82, and 0.83 in the validation set, respectively.ConclusionThe DCE-MRI-based radiomic features are significant biomarkers for distinguishing molecular subtypes of breast cancer noninvasively. Notably, the classification performance could be improved with the fusion analysis of multi-modal features.