40 research outputs found

    Preparation, characterization and enhanced photocatalytic activity of Ni2+ doped titania under solar light

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    Anatase TiO2 was prepared by sol-gel method through the hydrolysis of TiCl4. Ni2+ was doped into the TiO2 matrix in the concentration range of 0.02 to 0.1 at. and characterized by various analytical techniques. Powder X-ray diffraction revealed only anatase phase for all the samples, while diffuse reflectance spectral studies indicated a red shift in the band gap absorption to the visible region. The photocatalytic activities of these photocatalysts were probed for the degradation of methyl orange under natural solar light. The photocatalyst with optimum doping of 0.08 at. Ni2+, showed enhanced activity, which is attributed to: (i) effective separation of charge carriers and (ii) large red shift in the band gap to visible region. The influence of crystallite size and dopant concentration on the charge carrier trapping - recombination dynamics is investigated. √ā¬© Versita Warsaw and Springer-Verlag Berlin Heidelberg

    Enhanced photocatalytic activity of transition metal ions Mn2+, Ni2+ and Zn2+ doped polycrystalline titania for the degradation of Aniline Blue under UV/solar light

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    Anatase TiO2 was doped with divalent transition metal ions like Mn2+, Ni2+ and Zn2+ and characterized by various analytical techniques. Powder X-ray diffraction revealed stabilization of anatase phase for Ni2+ and Zn2+ doped samples, while phase transformation from anatase to rutile was promoted due to Mn2+ inclusion. The rutile fraction increased with Mn2+ concentration due to the creation of surface oxygen vacancies. All the doped catalysts showed red shift in the band gap absorption to the visible region. The photocatalytic activities of these catalysts were evaluated in the degradation of Aniline Blue (AB) under UV/solar light. Among the photocatalysts, Mn2+ (0.06 at.)-TiO2 showed enhanced activity, which is attributed to the synergistic effect in the bicrystalline framework of anatase and rutile. Further the unique half filled electronic structure of Mn2+ serves as a shallow trap for the charge carriers to enhance the photocatalytic activity. An insight to the mechanism of interfacial charge transfer in the mixed phase of anatase and rutile is explored, taking into consideration the theories of previous models. √ā¬© 2010 Elsevier B.V

    Design and Synthesis of Metal Complexes of (2 E

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    The photocatalytic degradation has been considered to be an efficient process for the degradation of organic pollutants, which are present in the effluents released by industries. The photocatalytic bleaching of cationic dye methylene blue was carried out spectrometrically on irradiation of UV light using Cu(II), Ni(II), and Co(II) complexes of (2E)-2-[(2E)-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide (HL). The effects of pH and metal ion were studied on the efficiency of the reaction. Cu(II) complex shows better catalytic activity and the highest percentage degradation (~88.8%) of methylene blue was observed at pH 12. A tentative mechanism has also been proposed for the photocatalytic degradation of methylene blue

    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

    Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial

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    Manipulation under anaesthesia and arthroscopic capsular release are costly and invasive treatments for frozen shoulder, but their effectiveness remains uncertain. We compared these two surgical interventions with early structured physiotherapy plus steroid injection. In this multicentre, pragmatic, three-arm, superiority randomised trial, patients referred to secondary care for treatment of primary frozen shoulder were recruited from 35 hospital sites in the UK. Participants were adults (‚Č•18 years) with unilateral frozen shoulder, characterised by restriction of passive external rotation (‚Č•50%) in the affected shoulder. Participants were randomly assigned (2:2:1) to receive manipulation under anaesthesia, arthroscopic capsular release, or early structured physiotherapy. In manipulation under anaesthesia, the surgeon manipulated the affected shoulder to stretch and tear the tight capsule while the participant was under general anaesthesia, supplemented by a steroid injection. Arthroscopic capsular release, also done under general anaesthesia, involved surgically dividing the contracted anterior capsule in the rotator interval, followed by manipulation, with optional steroid injection. Both forms of surgery were followed by postprocedural physiotherapy. Early structured physiotherapy involved mobilisation techniques and a graduated home exercise programme supplemented by a steroid injection. Both early structured physiotherapy and postprocedural physiotherapy involved 12 sessions during up to 12 weeks. The primary outcome was the Oxford Shoulder Score (OSS; 0-48) at 12 months after randomisation, analysed by initial randomisation group. We sought a target difference of 5 OSS points between physiotherapy and either form of surgery, or 4 points between manipulation and capsular release. The trial registration is ISRCTN48804508. Between April 1, 2015, and Dec 31, 2017, we screened 914 patients, of whom 503 (55%) were randomly assigned. At 12 months, OSS data were available for 189 (94%) of 201 participants assigned to manipulation (mean estimate 38¬∑3 points, 95% CI 36¬∑9 to 39¬∑7), 191 (94%) of 203 participants assigned to capsular release (40¬∑3 points, 38¬∑9 to 41¬∑7), and 93 (94%) of 99 participants assigned to physiotherapy (37¬∑2 points, 35¬∑3 to 39¬∑2). The mean group differences were 2¬∑01 points (0¬∑10 to 3¬∑91) between the capsular release and manipulation groups, 3¬∑06 points (0¬∑71 to 5¬∑41) between capsular release and physiotherapy, and 1¬∑05 points (-1¬∑28 to 3¬∑39) between manipulation and physiotherapy. Eight serious adverse events were reported with capsular release and two with manipulation. At a willingness-to-pay threshold of ¬£20‚Äą000 per quality-adjusted life-year, manipulation under anaesthesia had the highest probability of being cost-effective (0¬∑8632, compared with 0¬∑1366 for physiotherapy and 0¬∑0002 for capsular release). All mean differences on the assessment of shoulder pain and function (OSS) at the primary endpoint of 12 months were less than the target differences. Therefore, none of the three interventions were clinically superior. Arthoscopic capsular release carried higher risks, and manipulation under anaesthesia was the most cost-effective. The National Institute for Health Research Health Technology Assessment programme. [Abstract copyright: Copyright ¬© 2020 The Author(s). Publishedx by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection