63 research outputs found

    Hall Effect in the Viscous Incompressible Flow Through a Rotating Channel Between Two Porous Walls

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    Exact solutions for the velocity and induced magnetic field distributions, accounting for Hall currents have been obtained for the flow of a conducting porous walls under the action of a constant pressure gradient and in the presence of a uniform magnetic field transversely applied to the flow. Further, the channel is rotated with constant angular velocity about an axis perpendicular to the walls. For the purpose of mathematical simplicity, the magnetic prandtl number is assumed to be negligible. An expression for the boundary layer thickness dependent on Taylor, Hartmann, suction Reynolds numbers and Hall parameter has been obtained

    Searching for DNA Lesions: Structural Evidence for Lower- and Higher-Affinity DNA Binding Conformations of Human Alkyladenine DNA Glycosylase

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    To efficiently repair DNA, human alkyladenine DNA glycosylase (AAG) must search the million-fold excess of unmodified DNA bases to find a handful of DNA lesions. Such a search can be facilitated by the ability of glycosylases, like AAG, to interact with DNA using two affinities: a lower-affinity interaction in a searching process and a higher-affinity interaction for catalytic repair. Here, we present crystal structures of AAG trapped in two DNA-bound states. The lower-affinity depiction allows us to investigate, for the first time, the conformation of this protein in the absence of a tightly bound DNA adduct. We find that active site residues of AAG involved in binding lesion bases are in a disordered state. Furthermore, two loops that contribute significantly to the positive electrostatic surface of AAG are disordered. Additionally, a higher-affinity state of AAG captured here provides a fortuitous snapshot of how this enzyme interacts with a DNA adduct that resembles a one-base loop.National Institutes of Health (U.S.) (grant no. P30-ES002109)National Institutes of Health (U.S.) (grant no. GM65337)National Institutes of Health (U.S.) (grant no. GM65337-03S2)National Institutes of Health (U.S.) (grant no. CA055042)National Institutes of Health (U.S.) (grant no. CA092584)Repligen Corporation (KIICR Graduate Fellowship

    The Role of Purported Mucoprotectants in Dealing with Irritable Bowel Syndrome, Functional Diarrhea, and Other Chronic Diarrheal Disorders in Adults

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    Chronic diarrhea is a frequent presenting symptom, both in primary care medicine and in specialized gastroenterology units. It is estimated that more than 5% of the global population suffers from chronic diarrhea. and that about 40% of these subjects are older than 60 years. The clinician is frequently faced with the need to decide which is the best therapeutic approach for these patients. While the origin of chronic diarrhea is diverse, impairment of intestinal barrier function, dysbiosis. and mucosal micro-inflammation are being increasingly recognized as underlying phenomena characterizing a variety of chronic diarrheal diseases. In addition to current pharmacological therapies, there is growing interest in alternative products such as mucoprotectants, which form a mucoadhesive film over the epithelium to reduce and protect against the development of altered intestinal permeability, dysbiosis, and mucosal micro-inflammation. This manuscript focuses on chronic diarrhea in adults, and we will review recent evidence on the ability of these natural compounds to improve symptoms associated with chronic diarrhea and to exert protective effects for the intestinal barrier

    Tight junctions: from simple barriers to multifunctional molecular gates

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    Epithelia and endothelia separate different tissue compartments and protect multicellular organisms from the outside world. This requires the formation of tight junctions, selective gates that control paracellular diffusion of ions and solutes. Tight junctions also form the border between the apical and basolateral plasma-membrane domains and are linked to the machinery that controls apicobasal polarization. Additionally, signalling networks that guide diverse cell behaviours and functions are connected to tight junctions, transmitting information to and from the cytoskeleton, nucleus and different cell adhesion complexes. Recent advances have broadened our understanding of the molecular architecture and cellular functions of tight junctions

    Impact on Cognitive Improvement Following Burr Hole Evacuation of Chronic Subdural Hematoma: A Prospective Observational Study

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    Objective: Patients of Chronic subdural haematoma can present with only subtle cognitive impairment without any motor deficit. It is hence imperative for the treating clinician to be aware of this entity. The aim of the study was to identify any statistically significant improvement of cognitive functions following burr hole evacuation of Chronic SDH especially in the elderly patients. Methods and Material: A Prospective observational study of 30 patients of CSDH, from Jan 2015 to Dec 2016 was done at a tertiary level Armed Forces Hospital. The study had 23 male, 07 female, with age ranging from 7-85 years. The cognitive function of each patient was assessed at admission and 24 hours after surgery by MMSE. Radiological confirmation was done by CT head. Standard two burr holes were made and hematoma evacuated. The clinical, cognitive assessment and radiological data were collected and analysed. Results: There was no statistical significance preoperatively between age and pre operative cognitive impairment, headache, hemiparesis, dysarthria (P>0.05). We however found a statistically significant improvement postoperatively in cognitive impairment, headache (P=0.00), motor deficit (P=0.01) and dysarthria (P=0.046) Conclusion: The clinical features of dementia and other neurodegenerative disorders simulate CSDH in the geriatric population. These patients should have early neuroimaging and prompt surgical intervention to alleviate cognitive deficits

    Quantitative trait locus analysis and construction of consensus genetic map for foliar disease resistance based on two recombinant inbred line populations in cultivated groundnut (Arachis hypogaea L.)

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    Late leaf spot (LLS) and rust have the greatest impact on yield losses worldwide in groundnut (Arachis hypogaea L.). With the objective of identifying tightly linked markers to these diseases, a total of 3,097 simple sequence repeats (SSRs) were screened on the parents of two recombinant inbred line (RIL) populations, namely TAG 24 × GPBD 4 (RIL-4) and TG 26 × GPBD 4 (RIL-5), and segregation data were obtained for 209 marker loci for each of the mapping populations. Linkage map analysis of the 209 loci resulted in the mapping of 188 and 181 loci in RIL-4 and RIL-5 respectively. Using 143 markers common to the two maps, a consensus map with 225 SSR loci and total map distance of 1,152.9 cM was developed. Comprehensive quantitative trait locus (QTL) analysis detected a total of 28 QTL for LLS and 15 QTL for rust. A major QTL for LLS, namely QTLLLS01 (GM1573/GM1009-pPGPseq8D09), with 10.27–62.34% phenotypic variance explained (PVE) was detected in all the six environments in the RIL-4 population. In the case of rust resistance, in addition to marker IPAHM103 identified earlier, four new markers (GM2009, GM1536, GM2301 and GM2079) showed significant association with the major QTL (82.96% PVE). Localization of 42 QTL for LLS and rust on the consensus map identified two candidate genomic regions conferring resistance to LLS and rust. One region present on linkage group AhXV contained three QTL each for LLS (up to 67.98% PVE) and rust (up to 82.96% PVE). The second candidate genomic region contained the major QTL with up to 62.34% PVE for LLS. Molecular markers associated with the major QTL for resistance to LLS and rust can be deployed in molecular breeding for developing groundnut varieties with enhanced resistance to foliar diseases

    A One-pot tandem approach for the synthesis of 5-(Het)aryloxazoles from substituted (Het)aryl methyl alcohols and benzyl bromides

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    A new modified van Leusen strategy has been developed for the synthesis of biologically significant 5-substituted oxazoles by the reaction of (het)aryl methyl alcohols or benzyl bromides as precursors with tosylmethylisocyanide (TosMIC) under basic conditions. This method is efficient, takes place under mild reaction conditions, and is tolerant of various functional groups with high yield
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