1,036 research outputs found

    Non-surgical techniques in the treatment of peripheral vascular disease of the lower limb: preliminary results in a cohort of elderly, high risk patients

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    High recurrence rate supports need for secondary prophylaxis in non-HIV patients with disseminated mycobacterium avium complex infection: a multi-center observational study

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    © 2016 Sridhar et al.Background: Long-term outcomes in non-HIV immunocompromised patients with disseminated Mycobacterium avium complex (dMAC) infections are unknown and the need for post-treatment secondary prophylaxis against MAC is uncertain in this setting. The objective of this study was to determine the need of continuing secondary anti-MAC prophylaxis in non-HIV patients after completing treatment of the primary dMAC episode. Methods: We conducted a ten-year multi-center analysis of non-HIV immunosuppressed patients with dMAC infections in Hong Kong. Results: We observed sixteen patients with dMAC during the study period of which five (31 %) were non-HIV immunosuppressed patients. In the non-HIV immunosuppressed group, three patients completed a treatment course without secondary prophylaxis, one patient received azithromycin-based secondary prophylaxis and one patient was still receiving therapy for the first dMAC episode. All the three patients who completed treatment without being given secondary prophylaxis developed recurrent dMAC infection requiring retreatment. Conclusions: In view of the high rate of dMAC infection recurrence in non-HIV immunocompromised patients following treatment completion, our data support long-term anti-MAC suppression therapy after treatment of the first dMAC infection episode in immunocompromised non-HIV patients, as is recommended for patients with advanced HIV. Tests of cell mediated immune function need to be evaluated to guide prophylaxis discontinuation in non-HIV patients.published_or_final_versio

    Electrospun nanofiber membranes incorporating fluorosilane-coated TiO<inf>2</inf> nanocomposite for direct contact membrane distillation

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    © 2016 Elsevier B.V. The electrospinning technique as a method for fabricating hydrophobic membranes for membrane distillation (MD) has received much attention in recent times. In this study, TiO2 functionalized with 1H,1H,2H,2H-perfluorooctyltriethoxysilane was added directly to the dope solution for electrospinning in order to increase the hydrophobicity of the resulting MD membranes. Three concentrations (10%, 15% and 20%) of polyvinylidene fluoride-co-hexafluoropropylene (PH) dope solution were used for electrospinning with various amounts of TiO2 (1%, 5% and 10%) to generate nanofibers. The electrospun nanofiber membrane (ENM) of 20% PH with 10% TiO2 exhibited the highest surface hydrophobicity (contact angle=149°) resulting from good dispersion of the TiO2 particles, while the highest liquid entry pressure of 194.5 kPa was observed for the ENM comprising 10% PH with 10% TiO2 due to its reduced pore sizes. Furthermore, the ENMs containing 10% TiO2 exhibited better flux and stable salt rejection than commercial and ENMs without TiO2. Notably, there was no severe wetting in the 20% PH ENM with 10% TiO2 over seven days of operation, despite the high salt concentration (7.0 wt% NaCl) of the feed water

    Adsorption mechanism of hexavalent chromium onto layered double hydroxides-based adsorbents: A systematic in-depth review

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    © 2019 Elsevier B.V. An attempt has been made in this review to provide some insights into the possible adsorption mechanisms of hexavalent chromium onto layered double hydroxides-based adsorbents by critically examining the past and present literature. Layered double hydroxides (LDH) nanomaterials are typical dual-electronic adsorbents because they exhibit positively charged external surfaces and abundant interlayer anions. A high positive zeta potential value indicates that LDH has a high affinity to Cr(VI) anions in solution through electrostatic attraction. The host interlayer anions (i.e., Cl−, NO3−, SO42−, and CO32−) provide a high anion exchange capacity (53–520 meq/100 g) which is expected to have an excellent exchangeable capacity to Cr(VI) oxyanions in water. Regarding the adsorption-coupled reduction mechanism, when Cr(VI) anions make contact with the electron-donor groups in the LDH, they are partly reduced to Cr(III) cations. The reduced Cr(III) cations are then adsorbed by LDH via numerous interactions, such as isomorphic substitution and complexation. Nonetheless, the adsorption-coupled reduction mechanism is greatly dependent on: (1) the nature of divalent and trivalent salts utilized in LDH preparation, and the types of interlayer anions (i.e., guest intercalated organic anions), and (3) the adsorption experiment conditions. The low Brunauer–Emmett–Teller specific surface area of LDH (1.80–179 m2/g) suggests that pore filling played an insignificant role in Cr(VI) adsorption. The Langmuir maximum adsorption capacity of LDH (Qomax) toward Cr(VI) was significantly affected by the natures of used inorganic salts and synthetic methods of LDH. The Qomax values range from 16.3 mg/g to 726 mg/g. Almost all adsorption processes of Cr(VI) by LDH-based adsorbent occur spontaneously (ΔG° 0) and increase the randomness (ΔS° >0) in the system. Thus, LDH has much potential as a promising material that can effectively remove anion pollutants, especially Cr(VI) anions in industrial wastewater

    A Study on Field Emission Characteristics of Planar Graphene Layers Obtained from a Highly Oriented Pyrolyzed Graphite Block

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    This paper describes an experimental study on field emission characteristics of individual graphene layers for vacuum nanoelectronics. Graphene layers were prepared by mechanical exfoliation from a highly oriented pyrolyzed graphite block and placed on an insulating substrate, with the resulting field emission behavior investigated using a nanomanipulator operating inside a scanning electron microscope. A pair of tungsten tips controlled by the nanomanipulator enabled electric connection with the graphene layers without postfabrication. The maximum emitted current from the graphene layers was 170 nA and the turn-on voltage was 12.1 V

    Glutamatergic deficits and parvalbumin-containing inhibitory neurons in the prefrontal cortex in schizophrenia

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    <p>Abstract</p> <p>Background</p> <p>We have previously reported that the expression of the messenger ribonucleic acid (mRNA) for the NR2A subunit of the N-methyl-D-aspartate (NMDA) class of glutamate receptor was decreased in a subset of inhibitory interneurons in the cerebral cortex in schizophrenia. In this study, we sought to determine whether a deficit in the expression of NR2A mRNA was present in the subset of interneurons that contain the calcium buffer parvalbumin (PV) and whether this deficit was associated with a reduction in glutamatergic inputs in the prefrontal cortex (PFC) in schizophrenia.</p> <p>Methods</p> <p>We examined the expression of NR2A mRNA, labeled with a <sup>35</sup>S-tagged riboprobe, in neurons that expressed PV mRNA, visualized with a digoxigenin-labeled riboprobe via an immunoperoxidase reaction, in twenty schizophrenia and twenty matched normal control subjects. We also immunohistochemically labeled the glutamatergic axon terminals with an antibody against vGluT1.</p> <p>Results</p> <p>The density of the PV neurons that expressed NR2A mRNA was significantly decreased by 48-50% in layers 3 and 4 in the subjects with schizophrenia, but the cellular expression of NR2A mRNA in the PV neurons that exhibited a detectable level of this transcript was unchanged. In addition, the density of vGluT1-immunoreactive boutons was significantly decreased by 79% in layer 3, but was unchanged in layer 5 of the PFC in schizophrenia.</p> <p>Conclusion</p> <p>These findings suggest that glutamatergic neurotransmission via NR2A-containing NMDA receptors on PV neurons in the PFC may be deficient in schizophrenia. This may disinhibit the postsynaptic excitatory circuits, contributing to neuronal injury, aberrant information flow and PFC functional deficits in schizophrenia.</p

    The effect of posterior capsule repair upon post-operative hip dislocation following primary total hip arthroplasty

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    <p>Abstract</p> <p>Background</p> <p>Herein, we evaluated, retrospectively, the effect of posterior capsular repair upon postoperative hip dislocation subsequent to total hip arthroplasty (THA) incorporating a posterolateral approach.</p> <p>Methods</p> <p>A total of 181 patients undergoing 204 primary non-complicated THA surgical procedures in the period from January 2000 to October 2005 inclusively were included in this study. The patients were separated into two groups by whether the posterior capsular repair had been incorporated in the surgical procedure. For the surgeon did not commence repairing the posterior capsule until July, 2003, all members in the group that did not undergo posterior capsular repair (142 hips from 131 patients) were collected since January, 2000 to July, 2003, while the members in the group that underwent posterior capsular repair (62 hips from 52 patients) were followed since July, 2003, to October, 2005. With a minimum follow-up period of 12 months, we evaluated the early post-operative dislocation rate.</p> <p>Results</p> <p>The early postoperative hip-dislocation rate for the group who did not undergo posterior capsular repair appeared to be substantially greater (6.38% versus 0%) than the corresponding figure for the group the members of which underwent posterior capsular repair. In addition, patient demographics and the orientation of acetabular components for the replaced hip joints, as presented in postoperative radiographs, did not differ between the two groups.</p> <p>Conclusion</p> <p>Thus, surgeons should include posterior capsular repair as an important step in the surgical procedures of posterolateral approach for all THA in order to reduce the likelihood of early hip dislocation subsequent to THA.</p
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