59 research outputs found

    Effect of Silver Addition on the Ethanol-Sensing Properties of Indium Oxide Nanoparticle Layers: Optical Absorption Study

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    In2O3 and In2O3:Ag nanoparticle layers have been deposited using a two-step method consisting of chemical capping and dip coating techniques. The result of optical absorption analysis of In2O3:Ag samples shows the presence of Ag2O and Ag in air-annealed and vacuum-annealed samples, respectively. These results have been correlated with the gas sensing properties of these layers towards ethanol and support the proposed mechanism that increase in sensor response on Ag addition is due to the conversion of Ag2O to Ag in the presence of ethanol

    Identification of Clinical Immunological Determinants in Asymptomatic VL and Post Kala-azar Dermal Leishmaniasis Patients

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    Background: Visceral Leishmaniasis (VL) caused by protozoa belonging to the genus Leishmania, usually have anthroponotic mode of transmission and is issue of great public health importance in Indian subcontinent. Asymptomatic cases of VL and PKDL are subject of keen interest to find their role in the transmission of VL in epidemic areas. We evaluated the immunological cytokine determinants expressed in most clinical suspects of asymptomatic VL and PKDL (IL-10, IFN-γ, and TNF-α). Methods: Eighty-four participants were included at RMRIMS, Patna, India in 2016-17 out of which 64 asymptomatic individual positive for rK-39, without sign and symptoms of VL; 15 PKDL patient’s with past history of VL and 5 endemic healthy subjects were recruited from VL endemic areas. DAT and quantitative assessment of plasma cytokines was determined from the blood samples collected in a plain and sodium-EDTA vacutainer respectively from the subjects. Results: The mean level of IL-10 in DATposLOW of asymptomatic VL and PKDL was significantly higher than endemic healthy (P<0.05). The cytokine polarization index (IFN-γ versus IL-10) was significantly low in PKDL cases compared with asymptomatic VL cases in DATposLOW titre (P<0.05). This index was low again but statistically not significant in PKDL than in asymptomatic VL when TNF-α was considered against IL-10. The ratio of IFN-γ: IL-10 and TNF-α: IL-10 was observed decreased both in asymptomatic VL and PKDL cases than in healthy from endemic areas. Conclusion: Collectively we surmise from our data that asymptomatic VL can also play an important role like PKDL in transmission of VL

    Noninvasive Diagnosis of Visceral Leishmaniasis:Development and Evaluation of Two Urine-Based Immunoassays for Detection of Leishmania donovani Infection in India

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    Visceral leishmaniasis (VL), one of the most prevalent parasitic diseasesin the developing world causes serious health concerns. Post kala-azar dermal leishmaniasis (PKDL) is a skin disease which occurs after treatment as a sequel to VL. Parasitological diagnosis involves invasive tissue aspiration which is tedious and painful. Commercially available immunochromatographic rapid diagnostic test such as rK39-RDT is used for field diagnosis of VL, detects antibodiesin serum samples. Urine sample is however, much easier in collection,storage and handling than serum and would be a better alternative where collection of tissue aspirate or blood is impractical. In this study, we have developed and evaluated the performance of two urine-based diagnostic assays, ELISA and dipstick test, and compared the results with serologicalrK39-RDT. Our study shows the capability of urinebased tests in detecting anti-Leishmania antibodies effectively for both VL and PKDL diagnosis. The ability of dipstick test to demonstrate negative results after six months in 90% of the VL cases after treatment could be useful as a test of clinical cure. Urine-based tests can therefore replace the need for invasive practices and ensure better diagnosi

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Investigation of Cu2ZnSnS4 thin film by scanning Kelvin force microscopy

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    CZTS thin film has been grown on Mo-coated soda lime glass by co-sputtering the metal targets and post sulfurization in H2S ambient. The structural, microstructural, compositional and optical properties have been studied using glancing incidence XRD, Raman spectroscopy, SEM, EDS, XRF and UV-Vis spectrophotometry. Local electrical transport measurements using conducting AFM show that for small bias voltage (-0.5 V), the dark negative currents flow mainly through grain boundaries (GBs) rather than grain interior. Kelvin probe force microscopic measurements (local surface potential) indicated positive surface potential in the vicinity of GBs in a Cu-deficient CZTS thin film. All measurements indicated that grain interior to GBs have a smaller effective band gap than the bulk, due to the composition change (Cu-vacancies or CuZn anti site defects) at GBs. Electrical measurement revealed the presence of defects in the CZTS thin film

    A Special Section on Functional Nanomaterials for Solar Cells

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    The process of bringing out a special section for Journal of Nanoscience and Nanotechnology started with Dr. H. S. Nalwa inviting to bring out a special section on topic related to solar cells. During the course of discussion we came upon the topic of “functional nanomaterials for solar cells.” The purpose of this special section of Journal of Nanoscience and Nanotechnology is to summarize the recent developments in this important research field. Therefore, original research articles, short communications and review articles were invited on all types of functional nonomaterials associated with solar cells. Upon receiving the invitation several authors were kind enough to accept to contribute. Finally, the special section is being published with forty-two manuscripts, out of which four are review articles. The topics are focused on nanoscience and nanotechnology aspects of solar cells covering synthesis, spectroscopic characterization, properties, and applications of all types of nanomaterials in solar cells involving photodiodes, photodetectors, photoelectrochemical, etc. The research topics include nanofabrication and processing, manipulation, computational simulation, nanomachining, structure analysis, applications in nanoelectronics, nanooptics and nanophotonics using all kinds of materials which are parts of solar cell (absorber materials, buffer layers, transparent conducting oxide, up-conversion, down conversion materials, back and front contact, etc.)

    A Special Section on

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    Sodium induced grain growth, defect passivation and enhancement in the photovoltaic properties of Cu2ZnSnS4 thin film solar cell

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    Sodium diffusion from soda lime glass (SLG) during high temperature annealing is known to play a crucial role in affecting the grain growth and defect passivation in chalocogenide/kesterite solar cells. Additional sodium is required when low temperature or short term annealing is used. Although this fact is known, a systematic comparative study for kesterite films is seldom reported. In the present study, Cu2ZnSnS4 thin films were deposited on SLG and Mo coated SLG using stacked layer reactive sputtering. Na was deposited over the CZTS thin film and the film was annealed in N-2 atmosphere in order to enhance the grain growth. This resulted in the shift in the XRD peak towards lower diffraction angle. The optical bandgap shifted from 1.45 eV to 1.38 eV with Na addition. Significant grain growth from hundreds of nanometer to micrometer was observed in samples with Na. Device fabricated in SLG/Mo/CZTS/CdS/ZnO/ITO configuration with Al front contact shows increase in efficiencies values from 1.50% to 2.84%

    Mechanical and electrical properties of high performance MWCNT/polycarbonate composites prepared by an industrial viable twin screw extruder with back flow channel

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    High performance multiwall carbon nanotube (MWCNT) reinforced polycarbonate (PC) composites were prepared using an industrially viable fast dispersion process by a micro twin screw extruder with back flow channel and their mechanical and electrical properties were investigated for EMI shielding applications. A uniformly dispersed MWCNT/PC composite system was observed through SEM and TEM investigations. Incorporation of a small amount of MWCNT (2 wt%) led to enhancements in the tensile strength (up to 79.6 MPa) and flexural strength (up to 110 MPa), which were equivalent to 19.6% and 14.6% increases over the neat PC. The effect of MWCNTs on the failure mechanism of the PC under tensile loading showed a ductile to brittle transition with increasing concentration of MWCNTs. The results of enhanced mechanical properties were well supported by micro Raman spectroscopic studies. In addition to the mechanical properties, significant improvement in the electrical conductivity (0.01 S cm(-1) at 10 wt% MWCNT) of these composites was observed which yielded the EMI shielding of -27.2 dB in the Ku band suggesting their possible use as a high strength EMI shielding material
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