22 research outputs found

    Self-ordered TiO2 quantum dot array prepared via anodic oxidation

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    The template-based methods belong to low-cost and rapid preparation techniques for various nanostructures like nanowires, nanotubes, and nanodots or even quantum dots [QDs]. The nanostructured surfaces with QDs are very promising in the application as a sensor array, also called 'fluorescence array detector.' In particular, this new sensing approach is suitable for the detection of various biomolecules (DNA, proteins) in vitro (in clinical diagnostics) as well as for in vivo imaging

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Structures and orientation-dependent interaction forces of titania nanowires using molecular dynamics simulations

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    Engineering nano wires to develop new products and processes is highly topical due to their ability to provide highly enhanced physical, chemical, mechanical, thermal and electrical properties. In this work, using molecular dynamics simulations, we report fundamental information, about the structural and thermodynamic properties of individual anatase titania (TiO2) nanowires with cross-sectional diameters between 2 and 6 nm, and aspect ratio (Length: Diameter) of 6:1 at temperatures ranging from 300 to 3000 K. Estimates of the melting-transition temperature of the nanowires are between 2000 and 2500 K. The melting transition temperature predicted from the radial distribution functions (RDFs) shows strong agreement with those predicted from the total energy profiles. Overall, the transition temperature is in reasonable agreement with melting points predicted from experiments and simulations reported in the literature for spherical nanoparticles of similar sizes. Hence, the melting-transition temperature of TiO2 nanowires modelled here can be considered as shape independent. Furthermore, for the first time based on MD simulations, interaction forces between two nanowires are reported at ambient temperature (300 K) for different orientations: parallel, perpendicular, and end-to-end. It is observed that end-to-end orientations manifested the strongest attraction forces, while the parallel and perpendicular orientations, displayed weaker attractions. The results reported here could form a foundation in future multiscale modelling studies of the structured titania nanowire assemblies, depending on the inter-wire interaction forces

    Hypertension in a resource‐limited setting: Poor Outcomes on Short‐term Follow‐up in an Urban Hospital in Maputo, Mozambique

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    Mozambique has low levels of detection, treatment, and control of hypertension. However, data on target organ damage and clinical outcomes are lacking. The authors aimed at characterizing the clinical profile, pattern of target organ damage, and short‐term outcomes of patients referred to a first referral urban hospital in a low‐income setting in Africa. We conducted a prospective descriptive cohort study from February 2016 to May 2017 in Maputo, Mozambique. Adult patients with systolic and diastolic blood pressure ≥180 mm Hg and/or ≥110 mm Hg, respectively, or any systolic blood pressure above 140 mm Hg and/or diastolic blood pressure above 90 mm Hg in the presence of target organ damage (with or without antihypertensive treatment) were submitted to detailed physical examination, funduscopy, laboratory profile, electrocardiography, and echocardiography. Six months after the occurrence of complications (stroke, heart failure, and renal failure), hospital admission and death were assessed. Overall, 116 hypertensive patients were recruited (mean age 57.5 ± 12.8 years old; 111[95.7%] black; 81[70%] female) of which 79 had severe hypertension. The baseline mean values recorded for systolic and diastolic blood pressure were 192.3 ± 23.6 and 104.2 ± 15.2 mm Hg, respectively. Most patients (93; 80.2%) were on antihypertensive treatment. Patients’ risk profile revealed dyslipidemia, obesity, and diabetes in 59(54.1%), 48(42.5%), and 23(19.8%), respectively. Target organ damage was found in 111 patients. The commonest being left atrial enlargement 91(84.5%), left ventricular hypertrophy 57(50.4%), hypertensive retinopathy 30(26.3%), and chronic kidney disease 27(23.3%). Major events during 6‐month follow‐up were hospitalizations in 10.3% and death in 8.6% of the patients. Worsening of target organ damage occurred in 10 patients: four stroke, two heart failure, and four renal damage. Patients with severe hypertension and target organ damage were young with high‐risk profile, low hypertension control, and high occurrence of complications during short‐term follow‐up. Efforts to improve high blood pressure control are needed to reduce premature mortality in this highly endemic poor setting

    Diagnostic accuracy of the rapid Xpert HIV-1 Viral Load XC, Xpert HIV-1 Viral Load & m-PIMA HIV-1/2 Viral Load in South African clinics

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    Background: We aimed to evaluate the analytic performance of three rapid HIV viral load assays: the novel Xpert HIV-1 VL XC (Xpert XC), the Xpert HIV-1 VL (Xpert VL), and the m-PIMA HIV52 1/2 VL (m-PIMA). Setting: Two South African clinics. Methods: We conducted a prospective diagnostic accuracy study. Site-laboratory technicians and nurses used the Xpert XC, Xpert VL and m-PIMA to test plasma samples from people with HIV receiving antiretroviral therapy. We compared results with the Roche Cobas HIV-1 reference assay. We determined accuracy to detect viraemia at the World Health Organization (WHO) failure threshold of 1000 copies/mL on all three assays, and 50 and 200 copies/mL on the Xpert assays. We assessed agreement using Bland-Altman plots. Results: We enrolled 140 participants (98 [70%] women, median age 37 years), who provided 189 paired samples at one or more timepoints. We tested 174 samples with the Xpert XC, 188 with the Xpert VL, and 128 with the m-PIMA. At 1000 copies/mL, sensitivity and specificity (95% confidence intervals) were 97% (82-100) and 98% (93-99) (Xpert XC), 100% (87-100) and 96% (91-98) (Xpert VL), and 92% (72-99) and 99% (93-100) (m-PIMA) respectively. At 50 copies/mL, sensitivity and specificity were 93% (81-98) and 96% (91-99) (Xpert XC), and 95% (84-99) and 95% (90-98) (Xpert VL) respectively. Mean bias was -0.10 (-0.54 to 0.34) log10 copies/mL (Xpert XC), 0.07 (-0.37 to 0.52) log10 copies/mL (Xpert VL) and -0.26 (-0.83 to 0.31) log10 copies/mL (m-PIMA). Conclusions: In these South African clinics, the accuracy of all three assays was clinically acceptable to detect viraemia at the WHO failure threshold, while both Xpert assays were also accurate at detecting low level viraemia.</p

    Simplifying TREAtment and Monitoring for HIV (STREAM HIV): protocol for a randomised controlled trial of point-of-care urine tenofovir and viral load testing to improve HIV outcomes

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    Introduction: Substantial improvements in viral suppression among people living with HIV (PLHIV) are needed to end the HIV epidemic, requiring extensive scale-up of low-cost HIV monitoring services. Point-of-care (POC) tests for monitoring antiretroviral therapy (ART) adherence and viral load (VL) may be efficient and effective tools for real-time clinical decision making. We aim to evaluate the effects of a combined intervention of POC ART adherence and VL testing compared with standard-of-care on ART adherence, viral suppression and retention at 6 and 18 months post-ART initiation among PLHIV. Methods and analysis: Simplifying TREAtment and Monitoring for HIV (STREAM HIV) is a two-arm, open-label, randomised controlled superiority trial of POC urine tenofovir (POC TFV) and VL monitoring in PLHIV. We aim to enrol 540 PLHIV initiating a first-line ART regimen at a public HIV clinic in South Africa. Participants will be randomised 1:1 to the intervention or control arm. Intervention arm participants will receive monthly POC TFV testing for the first 5 months and POC VL testing at months 6 and 12. Intervention arm participants will also receive reflex POC TFV testing if viraemic and reflex HIV drug resistance testing for those with viraemia and detectable TFV. Control arm participants will receive standard-of-care, including laboratory-based VL testing at months 6 and 12. Primary outcomes include ART adherence (TFV-diphosphate concentration) at 6 months and viral suppression and retention at 18 months. Secondary outcomes include viral suppression and retention at 6 months, TFV-diphosphate concentration at 18 months, cost and cost-effectiveness of the intervention and acceptability of the intervention among PLHIV and healthcare workers. Ethics and dissemination: STREAM HIV has received ethical approval from the University of Washington Institutional Review Board (STUDY00007544), University of KwaZulu-Natal Biomedical Research Ethics Committee (BREC/00000833/2019) and Division of AIDS Regulatory Support Center (38509). Findings will be disseminated at international conferences and in peer-reviewed journals.</p
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