89 research outputs found

    The murine charged multivesicular body protein 2A, CHMP2A interacts with the 5’ and 3’ terminal regions of dengue virus complementary minus-strand RNA

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    Dengue (DEN) viruses, of which there are four distinct serotypes (DEN-1, -2, -3 and –4), belong to the Flaviviridae family. Their ‘plus’ sense RNA genomes contain Non-Translated Regions (NTRs) at their 5’ and 3’ ends. Replication of viral genomic RNA, which takes place in close association with host cell membranes, involves the initial synthesis of the complementary minus sense RNA intermediate. The NTRs, which have the potential to form stable stem-loop structures, are implicated to play a key role in the viral life cycle through binding to viral and/or host proteins. We have screened a mouse macrophage cDNA expression library with a mixture of radioactive plus and minus sense DEN-2 virus NTR transcripts and identified a ∼25 kDa protein. A BLAST analysis of the cDNA sequence encoding this protein showed it to be identical to human CHarged Multivesicular body Protein 2A, CHMP2A (also known as CHromatin Modifying Protein 2A), implicated in sorting proteins into endosome-derived vesicles. Recombinant murine CHMP2A was expressed in E. coli as a 6x His tagged protein, purified to homogeneity and shown to interact preferentially with the minus sense 5’ and 3’ NTRs of all four DEN virus serotypes. Using DEN-2 virus 5’ (-) and 3’ (-) NTRs we could demonstrate the specificity of this binding activity in vitro by ultraviolet cross-linking and electrophoretic mobility shift assays, carried out in the absence and presence of specific and nonspecific competitors. Finally, this unique RNA/protein interaction was verified in vivo using a yeast based interaction assay

    Catching the “Tail/Tale” of Teaching Qualitative Inquiry to Novice Researchers

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    This article responds to the call for deeper examination of qualitative inquiry teaching practices by presenting representative examples from the pedagogies of three teacher-educators who have taught Qualitative Research Methods courses for the past 15 years. We focus in particular on the pedagogical complexities of teaching data analysis, which is a topic that remains under-theorized and under-represented in contemporary scholarship on qualitative methodologies. Using a critical friends framework, we analyze and synthesize our pedagogical responses to key dilemmas we have encountered in our respective contexts, all state universities, to introducing qualitative inquiry to novice researchers who often enter the analytic process with positivist notions of knowledge creation. They sometimes enter the analytic process with the belief if they can only “catch the tail” of this thing called qualitative research they will be able to “do it right.” Yet, as the metaphor implies, catching a fierce beast by the tail, thinking you can control its actions, can intrude on the inductive and holistic character of the qualitative inquiry process

    Surface modification of substrates

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    The present invention is directed to a practically universal surface modification process and the materials thereby obtained. In general, the process includes initial epoxy modification of a substrate surface by attachment of an epoxy-containing polymer to the surface. Following attachment of the polymer, still-existing epoxy groups on the polymer may then cross-link the polymer to form a unified anchoring layer on the surface. Other epoxy groups in the anchoring layer, not utilized in forming the layer may be used to graft surface modifying materials to the surface. For instance, macromolecules, biomolecules, polymers, and polymerization initiators may be grafted to the surface via the anchoring layer

    Surface modification of substrates

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    The present invention is directed to a practically universal surface modification process and the materials thereby obtained. In general, the process includes initial epoxy modification of a substrate surface by attachment of an epoxy-containing polymer to the surface. Following attachment of the polymer, still-existing epoxy groups on the polymer may then cross-link the polymer to form a unified anchoring layer on the surface. Other epoxy groups in the anchoring layer, not utilized in forming the layer may be used to graft surface modifying materials to the surface. For instance, macromolecules, biomolecules, polymers, and polymerization initiators may be grafted to the surface via the anchoring layer

    Epidemiology of patients presenting to a pediatric emergency department in Karachi, Pakistan

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    Background: There is little data describing pediatric emergencies in resource-poor countries, such as Pakistan. We studied the demographics, management, and outcomes of patients presenting to the highest-volume, public, pediatric emergency department (ED) in Karachi, Pakistan.Methods: In this prospective, observational study, we approached all patients presenting to the 50-bed ED during 28 12-h study periods over four consecutive weeks (July 2013). Participants’ chief complaints and medical care were documented. Patients were followed-up at 48-h and 14-days via telephone. Results: Of 3115 participants, 1846 were triaged to the outpatient department and 1269 to the ED. Patients triaged to the ED had a median age of 2.0 years (IQR 0.5–4.0); 30% were neonates (\u3c 28 days). Top chief complaints were fever (45.5%), diarrhea/vomiting (32.3%), respiratory (23.1%), abdominal (7.5%), and otolaryngological problems (5.8%). Temperature, pulse and respiratory rate, and blood glucose were documented for 66, 42, and 1.5% of patients, respectively. Interventions included medications (92%), IV fluids (83%), oxygen (35%), and advanced airway management (5%). Forty-five percent of patients were admitted; 11 % left against medical advice. Outcome data was available at time of ED disposition, 48-h, and 14 days for 83, 62, and 54% of patients, respectively. Of participants followed-up, 4.3% died in the ED, 11.5% within 48 h, and 19.6% within 14 days.Conclusions: This first epidemiological study at Pakistan’s largest pediatric ED reveals dramatically high mortality, particularly among neonates. Future research in developing countries should focus on characterizing reasons for high mortality through pre-ED arrival tracking, ED care quality assessment, and post-ED follow-up

    Correction to: Epidemiology of patients presenting to a pediatric emergency department in Karachi, Pakistan

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    An amendment to this paper has been published and can be accessed via the original article

    Corrosion Protection of Steel Using Nonanomalous Ni-Zn-P Coatings

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    A novel technique for obtaining nonanomalous Ni-Zn-P coatings with high Ni content (74 wt % as compared to 15-20 wt % in the conventional plating method) has been developed. These coatings show promise as a replacement for Cd in sacrificially protecting steel. Ni-Zn-P coatings were deposited using an electroless method from a solution containing NiSO4, complexing agent and ammonium chloride. Varying the concentration of ZnSO4 in the bath controls the final amount of Zn in the deposit. The Zn content in the coating was optimized based on the corrosion resistance of the final deposit. Coatings with 16.2 wt % Zn were found to display a potential of –0.652 V vs. SCE that is more electronegative to steel and hence can be used as a sacrificial coating for the protection of steel. Deposition parameters like pH and temperature have been optimized based on composition of the coating and the surface morphology. Corrosion studies in corroding media show that Ni-Zn-P coatings obtained using the electroless method show a higher barrier resistance and better stability as compared to cadmium coatings

    Superparamagnetic core-shell nanoparticles for biomedical applications

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    Superparamagnetic magnetite (Fe3O4) nanoparticles have been widely studied for various scientific and technological applications such as magnetic storage media, contrast agents for magnetic resonance imaging (MRI), biolabelling and separation of biomolecules, and magnetic targetted drug delivery. In the absence of surface coating, Fe3O4 nanoparticles tend to aggregate due to the Van der Waals forces coupled with the magnetic dipole-dipole attractions between the particles. In order to successfully prepare stable magnetite dispersions, any attractive forces between the nanoparticles must be overcome. In this study, magnetite nanoparticles have been prepared by chemical precipitation method. Gold (Au) and silver (Ag) are ideal coating for Fe3O4 nanoparticles due to their high chemical stability, biocompatibility, and their affinity for binding to amine/thiol terminal groups of organic molecules. In addition these coatings also render the Fe3O4 nanoparticles with plasmonic properties
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