221 research outputs found

    Ultrafine conducting fibers: metallization of poly(acrylonitrile-co-glycidyl methacrylate) nanofibers

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    Electrospun poly(glycidylmethacrylate) (PGMA) and poly(acrylonitrile-co-glycidyl methacrylate) (P(AN-GMA)) nanofibers were coated with monodisperse silver nanoparticles by using an electroless plating technique at ambient conditions. Oxirane groups on the surface of nanofibers were replaced with reducing agent, hydrazine. Surface modified nanofibers were allowed to react with ammonia solution of AgNO3. A redox reaction takes place and metallic silver nucleate on fibers surface. Parameters affecting the particle size were determined

    A case of urinary tract infection caused by Raoultella planticola after a urodynamic study

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    AbstractHere we report the case of a patient who developed urinary tract infection after a urodynamic study. The causative agent was Raoultella planticola, a rare opportunistic pathogen that usually invades immunocompromised patients. While a urinary tract infection with R. planticola has been previously described, this is the first report in which an R. planticola infection developed after a urodynamic study. We postulate that the mechanism of infection was direct invasion of the urinary tract from contaminated urodynamic study equipment. Here, we discuss the role played by isotonic solutions in facilitating bacterial reproduction

    Can gestational exercise have a positive effect on cognitive functions resulting from brain injury? A rat study

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    Aim: The effects of gestational exercise on potential pathological conditions is not known yet.  Therefore, in the present study, it was aimed to evaluate the effects of forced running exercise on LPS-induced brain damage in pregnant rats. Method: Pregnant females in the experimental group were forced to exercise 30 min daily for five days a week. Lipopolysaccharide (LPS) induced brain injury model was created by administering 500 µg/kg body weight of LPS on gestational days 18 and 19.   To evaluate injury histopathologically, brain tissues were fixed at the postnatal day seven through transcardial perfusion (n=4 pups/group). When the remaining pups reached 30-day of age, Morris water maze test (MWM) was performed to assess memory and learning, open filed (OP) and elevated plus maze (EPM) for testing anxiety, and Porsolt test (PT) for evaluating depression. The groups were defined as brain injury group (BI, n=13) and exercise+brain injury group (E+BI, n=7).  Results: The results obtained from MWM test indicated that animals found the platform in a shorter duration and distance at the day five compared to the day three. However, there was no significant difference between the groups. No significant difference was found in OP test regarding the distance traveled, time spent at the margins, movement at the center and the time spent as immobile. However, in the EPM test, the offspring at the BI group displayed higher mobility and increased number of entry to the open arms compared to the E+BI groups (p=0.01).  There was no significant difference regarding mobility duration and total distance traveled in the PT test. Conclusion: In the present study, we tested the impact of gestational exercise using the brain injury model. The results of the EPM test suggests that the gestational exercise can suppress the stress factors in the pregnant females with brain injury leading to the prevention of hyperactivity-induced negative learning behavior

    An Interoperability Platform Enabling Reuse of Electronic Health Records for Signal Verification Studies

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    Depending mostly on voluntarily sent spontaneous reports, pharmacovigilance studies are hampered by low quantity and quality of patient data. Our objective is to improve postmarket safety studies by enabling safety analysts to seamlessly access a wide range of EHR sources for collecting deidentified medical data sets of selected patient populations and tracing the reported incidents back to original EHRs. We have developed an ontological framework where EHR sources and target clinical research systems can continue using their own local data models, interfaces, and terminology systems, while structural interoperability and Semantic Interoperability are handled through rule-based reasoning on formal representations of different models and terminology systems maintained in the SALUS Semantic Resource Set. SALUS Common Information Model at the core of this set acts as the common mediator. We demonstrate the capabilities of our framework through one of the SALUS safety analysis tools, namely, the Case Series Characterization Tool, which have been deployed on top of regional EHR Data Warehouse of the Lombardy Region containing about 1 billion records from 16 million patients and validated by several pharmacovigilance researchers with real-life cases. The results confirm significant improvements in signal detection and evaluation compared to traditional methods with the missing background information

    Protonation States of Remote Residues Affect Binding-Release Dynamics of the Ligand but not the Conformation of apo Ferric Binding Protein

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    We have studied the apo (Fe3+ free) form of periplasmic ferric binding protein (FbpA) under different conditions and we have monitored the changes in the binding and release dynamics of H2PO4- that acts as a synergistic anion in the presence of Fe3+. Our simulations predict a dissociation constant of 2.2±\pm0.2 mM which is in remarkable agreement with the experimentally measured value of 2.3±\pm0.3 mM under the same ionization strength and pH conditions. We apply perturbations relevant for changes in environmental conditions as (i) different values of ionic strength (IS), and (ii) protonation of a group of residues to mimic a different pH environment. Local perturbations are also studied by protonation or mutation of a site distal to the binding region that is known to mechanically manipulate the hinge-like motions of FbpA. We find that while the average conformation of the protein is intact in all simulations, the H2PO4- dynamics may be substantially altered by the changing conditions. In particular, the bound fraction which is 20%\% for the wild type system is increased to 50%\% with a D52A mutation/protonation and further to over 90%\% at the protonation conditions mimicking those at pH 5.5. The change in the dynamics is traced to the altered electrostatic distribution on the surface of the protein which in turn affects hydrogen bonding patterns at the active site. The observations are quantified by rigorous free energy calculations. Our results lend clues as to how the environment versus single residue perturbations may be utilized for regulation of binding modes in hFbpA systems in the absence of conformational changes.Comment: 26 pages, 4 figure
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