16 research outputs found

    Modification of bacterial cellulose using silk fibroin β-sheet crystals induced by ultrasonication

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    Silk fibroin (SF) has been continuously explored as a biomaterial due to its biocompatibility, tunability, and self-healing properties. In this work, we present a novel approach to the modification of bacterial cellulose (BC) with SF β-sheet dominant structures induced via ultrasonication. Secondary structure analysis through infrared spectroscopy, thioflavin T assay, and circular dichroism spectropolarimetry revealed a conversion of silk I to silk II structures within the protein mixture. Cold field emission scanning electron microscope images revealed the tightly packed fibers coated with the protein. Thermogravimetric curves demonstrated higher resistance to temperature degradation supplemented by broader and flatter DSC curves attributed to the highly bonded and dense composite. Successful conversion of amide I to amide II and amide III allowed for the more stable β-crystals to contribute to a more thermodynamically stable double-network hydrogel. The conversion of silk I to silk II structures offers a viable and highly biocompatible material that is both thermodynamically and biochemically stable for various potential biomedical applications

    Three dimensional structure directs T-cell epitope dominance associated with allergy

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    <p>Abstract</p> <p>Background</p> <p>CD4+ T-cell epitope immunodominance is not adequately explained by peptide selectivity in class II major histocompatibility proteins, but it has been correlated with adjacent segments of conformational flexibility in several antigens.</p> <p>Methods</p> <p>The published T-cell responses to two venom allergens and two aeroallergens were used to construct profiles of epitope dominance, which were correlated with the distribution of conformational flexibility, as measured by crystallographic B factors, solvent-accessible surface, COREX residue stability, and sequence entropy.</p> <p>Results</p> <p>Epitopes associated with allergy tended to be excluded from and lie adjacent to flexible segments of the allergen.</p> <p>Conclusion</p> <p>During the initiation of allergy, the N- and/or C-terminal ends of proteolytic processing intermediates were preferentially loaded into antigen presenting proteins for the priming of CD4+ T cells.</p

    A History of Molecular Chaperone Structures in the Protein Data Bank

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    Thirty years ago a class of proteins was found to prevent the aggregation of Rubisco. These proteins&rsquo; ability to prevent unwanted associations led to their being called chaperones. These chaperone proteins also increased in expression as a response to heat shock, hence their label as heat shock proteins (Hsps). However, neither label encompasses the breadth of these proteins&rsquo; functional capabilities. The term &ldquo;unfoldases&rdquo; has been proposed, as this basic function is shared by most members of this protein family. Onto this is added specializations that allow the different family members to perform various cellular functions. This current article focuses on the resolved structural bases for these functions. It reviews the currently available molecular structures in the Protein Data Bank for several classes of Hsps (Hsp60, Hsp70, Hsp90, and Hsp104). When possible, it discusses the complete structures for these proteins, and the types of molecular machines to which they have been assigned. The structures of domains and the associated functions are discussed in order to illustrate the rationale for the proposed unfoldase function

    Level of anxiety of patients undergoing transvaginal ultrasound in selected hospitals in Laguna

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    The study used a descriptive research design method. The State-Trait Anxiety Inventory questionnaire was used to determine the level of anxiety of 50 patients undergoing transvaginal ultrasound in selected hospitals in Laguna. The study used purposive sampling technique. The research instrument was an adapted questionnaire that determined the level of anxiety of patients undergoing transvaginal ultrasound. The statistical tools that were used to analyze the data were percentage, mean, standard deviation, t-test for Independent means and analysis of variance (ANOVA). Based on the findings of the study, the following conclusions are drawn: 1) Majority of the respondents are 18 to 39 years old and married; 2) The study revealed that the patients undergoing transvaginal ultrasound are moderately anxious; 3) There is no significant difference in the level of anxiety of the respondents when grouped according to age. There is a significant difference in the level of anxiety of the respondents when they are grouped according to civil status. Respondents who are married have significantly higher level of anxiety compared to the respondents who are single, widowed and separated

    Relationship of compliance to ergonomic training and work-related musculoskeletal complaints among office workers of Nalco Philippines Inc.

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    The study utilized a correlational type of research design using convenience sampling. A total of 50 office workers were included in the population but only 44 agreed to participate in the study. A questionnaire (M-NMQ) and Researcher Made Observation Checklist were used as data gathering tools. Statistical techniques used were Kendall Tau-B correlation coefficient to determine the relationship of office workers in NPI with work-related musculoskeletal complaints as to monitor, keyboard, mouse, chair, level of object, lighting, temperature and rest break and Fishers’ Exact Test to determine the correlation between office workers in NPI with compliance to ergonomic training and work-related musculoskeletal complaints. Based from the results of this study, compliance of the office workers of NPI to the given training is not a sufficient basis alone to determine the relationship between the compliance and work-related musculoskeletal complaints. The activities outside work can also be a major factor in the development of work-related musculoskeletal complaints. This includes the household chores, travelling, driving, sports, outing, dancing, jogging, going to the gym and gardening
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