Tissue and organ failure has induced immense economic and healthcare concerns across the world. Tissue engineering is an interdisciplinary biomedical approach which aims to address the issues ...intrinsic to organ donation by providing an alternative strategy to tissue and organ transplantation. This review is specifically focused on cartilage tissue. Cartilage defects cannot readily regenerate, and thus research into tissue engineering approaches is relevant as a potential treatment option. Cells, scaffolds, and growth factors are three components that can be utilized to regenerate new tissue, and in particular recent advances in microparticle technology have excellent potential to revolutionize cartilage tissue regeneration. First, microspheres can be used for drug delivery by injecting them into the cartilage tissue or joint space to reduce pain and stimulate regeneration. They can also be used as controlled release systems within tissue engineering constructs. Additionally, microcarriers can act as a surface for stem cells or chondrocytes to adhere to and expand, generating large amounts of cells, which are necessary for clinically relevant cell therapies. Finally, a newer application of microparticles is to form them together into granular hydrogels to act as scaffolds for tissue engineering or to use in bioprinting. Tissue engineering has the potential to revolutionize the space of cartilage regeneration, but additional research is needed to allow for clinical translation. Microparticles are a key enabling technology in this regard.
Phosphorylation of proteins on tyrosine (Tyr) residues evolved in metazoan organisms as a mechanism of coordinating tissue growth
. Multicellular eukaryotes typically have more than 50 distinct ...protein Tyr kinases that catalyse the phosphorylation of thousands of Tyr residues throughout the proteome
. How a given Tyr kinase can phosphorylate a specific subset of proteins at unique Tyr sites is only partially understood
. Here we used combinatorial peptide arrays to profile the substrate sequence specificity of all human Tyr kinases. Globally, the Tyr kinases demonstrate considerable diversity in optimal patterns of residues surrounding the site of phosphorylation, revealing the functional organization of the human Tyr kinome by substrate motif preference. Using this information, Tyr kinases that are most compatible with phosphorylating any Tyr site can be identified. Analysis of mass spectrometry phosphoproteomic datasets using this compendium of kinase specificities accurately identifies specific Tyr kinases that are dysregulated in cells after stimulation with growth factors, treatment with anti-cancer drugs or expression of oncogenic variants. Furthermore, the topology of known Tyr signalling networks naturally emerged from a comparison of the sequence specificities of the Tyr kinases and the SH2 phosphotyrosine (pTyr)-binding domains. Finally we show that the intrinsic substrate specificity of Tyr kinases has remained fundamentally unchanged from worms to humans, suggesting that the fidelity between Tyr kinases and their protein substrate sequences has been maintained across hundreds of millions of years of evolution.
College students are known to have unhealthy levels of sleep. Using data from the StudentLife Dataset, we analyzed the predictors of “recall bias” regarding sleep. We compared the average of a ...running, daily, self-reported sleep value over a period of time to the average sleep amount perceived by the students in their PSQI (Pittsburgh Sleep Quality Index) tests. We found that the variability in the measure of self-assessment of health was related to errors in sleep recall, as were some individual parameters.
We have built equipment that can visualize the angle distributions of scattered X-rays. The main body of the equipment is made of a lead-shielded box 340 mm long, 300 mm wide and 270 mm high. The ...collimated X-rays are introduced into the equipment from the front face, then scattered by the sample located in the center of the equipment. The X-rays scattering toward the upper side are detected by the phosphor plate. To verify the usability of the equipment, an experiment using diagnostic X-rays was carried out. X-rays with a tube voltage of 100 kV were narrowed down to 6 mm(phi) and a 2 mm-thick acrylic sample was irradiated. The experimental conditions with a tube current-time product of 300 mAs to 1500 mAs proved appropriate for obtaining suitable images on a 10 inch x 12 inch phosphor plate. The obtained images were analyzed using ImageJ. The experimental values were in good agreement with the theoretical distribution calculated by Klein and Nishina. Because the distribution of the scattered X-rays can be visualized in relatively simple experiments using the developed equipment, it is hoped that it will be of use for the practical training of beginners.
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