102 research outputs found

    Application of DIC in Solid Mechanics

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    During service life, composite structures are susceptible to damage which reduces their structural integrity. For improved service life, the damage needs to be repaired. In case of low velocity impact damage adhesively bonded patch repair has shown to be cost effective and most efficient in extending service life of damaged parts. The repair performance is mainly influenced by patch stacking sequence, patch shape, patch thickness, overlap length and adhesive strength. In the first phase of work, a 3D finite element based study is carried out using mechanics based approach to optimize the patch dimensions and stacking sequence so that the performance of repaired structure can be improved. Also, a genetic algorithm based approach in-conjunction with finite element analysis is implemented for arriving at an optimized patch and adhesive dimensions. Experimental study is then carried out with optimized geometry using non-contact optical based technique namely digital image correlation (DIC). The mechanics of double and single sided repair are discussed in detail and strain field from DIC have been compared with finite element (FE) estimates

    Compositional alterations in erythrocyte membranes in Type II diabetes

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    Loss of erythrocyte membrane deformability is one of the most crucial factors in developing complications associated with Type II diabetes. The observed loss of erythrocyte membrane deformability could be related to structural changes in the membrane. In this context, here, we have made an attempt at gaining a better insight (quantitative as well as qualitative) into the protein and lipid contents in erythrocyte membranes and their interrelationships in Type II diabetes. Age matched control (n=12) and Type II diabetic subjects (n=22) were selected for this study. Morphological characteristics were studied by atomic force microscopy (AFM). AFM study confirmed remarkable alterations in morphology of the diabetic erythrocytes. In diabetic erythrocytes following changes were noted: (i) Significant increase in membrane as well as cytosolic proteins with a marginal increase in phospholipids content; (ii) The membrane total lipids:protein, phospholipids:protein, cholesterol:protein and phospholipids:cholesterol (mole:mole) ratios decreased significantly; (iii). A reproducible decrease in docosahexaenoic acid (DHA) and Omega-3 index with increase in Omega-6:Omega-3 ratio in membrane fatty acids; and (iv) The SDS-PAGE analysis indicated that all membrane proteins increased in almost equal proportion leading to increased membrane protein content. The observed compositional and stochiometric changes in lipids, proteins and their ratios may underlie morphological alterations and loss of deformability

    Compositional alterations in erythrocyte membranes in Type II diabetes

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    671-679Loss of erythrocyte membrane deformability is one of the most crucial factors in developing complications associated with Type II diabetes. The observed loss of erythrocyte membrane deformability could be related to structural changes in the membrane. In this context, here, we have made an attempt at gaining a better insight (quantitative as well as qualitative) into the protein and lipid contents in erythrocyte membranes and their interrelationships in Type II diabetes. Age matched control (n=12) and Type II diabetic subjects (n=22) were selected for this study. Morphological characteristics were studied by atomic force microscopy (AFM). AFM study confirmed remarkable alterations in morphology of the diabetic erythrocytes. In diabetic erythrocytes following changes were noted: (i) Significant increase in membrane as well as cytosolic proteins with a marginal increase in phospholipids content; (ii) The membrane total lipids:protein, phospholipids:protein, cholesterol:protein and phospholipids:cholesterol (mole:mole) ratios decreased significantly; (iii). A reproducible decrease in docosahexaenoic acid (DHA) and Omega-3 index with increase in Omega-6:Omega-3 ratio in membrane fatty acids; and (iv) The SDS-PAGE analysis indicated that all membrane proteins increased in almost equal proportion leading to increased membrane protein content. The observed compositional and stochiometric changes in lipids, proteins and their ratios may underlie morphological alterations and loss of deformability

    Signaling via a CD27-TRAF2-SHP-1 axis during naive T cell activation promotes memory-associated gene regulatory networks.

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    The interaction of the tumor necrosis factor receptor (TNFR) family member CD27 on naive CD8 <sup>+</sup> T (Tn) cells with homotrimeric CD70 on antigen-presenting cells (APCs) is necessary for T cell memory fate determination. Here, we examined CD27 signaling during Tn cell activation and differentiation. In conjunction with T cell receptor (TCR) stimulation, ligation of CD27 by a synthetic trimeric CD70 ligand triggered CD27 internalization and degradation, suggesting active regulation of this signaling axis. Internalized CD27 recruited the signaling adaptor TRAF2 and the phosphatase SHP-1, thereby modulating TCR and CD28 signals. CD27-mediated modulation of TCR signals promoted transcription factor circuits that induced memory rather than effector associated gene programs, which are induced by CD28 costimulation. CD27-costimulated chimeric antigen receptor (CAR)-engineered T cells exhibited improved tumor control compared with CD28-costimulated CAR-T cells. Thus, CD27 signaling during Tn cell activation promotes memory properties with relevance to T cell immunotherapy

    Red flags for the early detection of spinal infection in back pain patients

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    © 2019 The Author(s). Background: Red flags are signs and symptoms that are possible indicators of serious spinal pathology. There is limited evidence or guidance on how red flags should be used in practice. Due to the lack of robust evidence for many red flags their use has been questioned. The aim was to conduct a systematic review specifically reporting on studies that evaluated the diagnostic accuracy of red flags for Spinal Infection in patients with low back pain. Methods: Searches were carried out to identify the literature from inception to March 2019. The databases searched were Medline, CINHAL Plus, Web of Science, Embase, Cochrane, Pedro, OpenGrey and Grey Literature Report. Two reviewers screened article texts, one reviewer extracted data and details of each study, a second reviewer independently checked a random sample of the data extracted. Results: Forty papers met the eligibility criteria. A total of 2224 cases of spinal infection were identified, of which 1385 (62%) were men and 773 (38%) were women mean age of 55 (± 8) years. In total there were 46 items, 23 determinants and 23 clinical features. Spinal pain (72%) and fever (55%) were the most common clinical features, Diabetes (18%) and IV drug use (9%) were the most occurring determinants. MRI was the most used radiological test and Staphylococcus aureus (27%), Mycobacterium tuberculosis (12%) were the most common microorganisms detected in cases. Conclusion: The current evidence surrounding red flags for spinal infection remains small, it was not possible to assess the diagnostic accuracy of red flags for spinal infection, as such, a descriptive review reporting the characteristics of those presenting with spinal infection was carried out. In our review, spinal infection was common in those who had conditions associated with immunosuppression. Additionally, the most frequently reported clinical feature was the classic triad of spinal pain, fever and neurological dysfunction. This is an Open Access article distributed in accordance with the Creative Commons Attribution Non-Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
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