452 research outputs found

    Transport and magnetic properties in YBaCo2O5.45: Focus on the high-temperature transition

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    The electronic transport properties and the magnetic susceptibility were measured in detail in YBaCo2O5.45YBaCo_2O_{5.45}. Close to the so-called metal-insulator transition, strong effects of resistance relaxation, a clear thermal hysteresis and a sudden increase of the resistance noise are observed. This is likely due to the first order character of the transition and to the underlying phases coexistence. Despite these out of equilibrium features, a positive and linear magneto-resistance is also observed, possibly linked to the heterogeneity of the state. From a magnetic point of view, the paramagnetic to ordered magnetic state transition is observed using non linear susceptibilty. This transition shows the characteristics of a continuous transition, and time dependent effects can be linked with the dynamics of magnetic domains in presence of disorder. Thus, when focusing on the order of the transitions, the electronic one and the magnetic one can not be directly associated.Comment: accepted for publication in PR

    Financial Distress and Healthcare: A Study of Migrant Dalit Women Domestic Helpers in Bangalore, India

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    The Indian caste system originated in ancient India and gradually evolved concurrently with Indian history. Dalits in Indian history were considered as lower caste untouchables and were deprived of basic human rights. After the onset of modern economic development and the progressive initiatives taken by the government, the situation has improved considerably. The modern Indian state, since independence has been oriented towards providing reservations for Dalits in education and other public services. However, even with continuous efforts to eradicate the caste system and numerous measures to improve their lives, Dalits, specifically Dalit women, are still deprived of their basic needs. Many of them have moved to urban areas to earn their livelihoods and find employment mostly in the unorganized sector. Empowering these large numbers of Dalit women is a challenging endeavour, especially when they are deprived and mostly unaware of basic healthcare needs. The present research paper aims to discover the factors influencing the migration of Dalit women. It explores the deteriorating quality of life experienced by Dalit women with increased out-of-pocket expenditures for healthcare. The paper suggests cost-effective practices for reducing healthcare payments for low-income Dalit domestic helpers. The researcher conducted a cross-sectional survey using an in-depth interview with 10 Dalit women working as domestics in Bangalore. A convenient sampling method was used to select the sample. Thematic content analysis with some grounded theory was used to analyse data. NVivo12 Pro software was used for qualitative data analysis. Observed results suggest poverty and caste discrimination were the main reasons for migration. Results indicate that better cost-effective healthcare facilities would improve the quality of life of Dalit women. However, empowering and entitling Dalit women is the greatest challenge

    Protein L: a novel reagent for the detection of Chimeric Antigen Receptor (CAR) expression by flow cytometry

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    <p>Abstract</p> <p>Background</p> <p>There has been significant progress in the last two decades on the design of chimeric antigen receptors (CAR) for adoptive immunotherapy targeting tumor-associated antigens. Structurally CARs consist of a single chain antibody fragment directed against a tumor-associated antigen fused to an extracellular spacer and transmembrane domain followed by T cell cytoplasmic signaling moieties. Currently several clinical trials are underway using gene modified peripheral blood lymphocytes (PBL) with CARs directed against a variety of tumor associated antigens. Despite the improvements in the design of CARs and expansion of the number of target antigens, there is no universal flow cytometric method available to detect the expression of CARs on the surface of transduced lymphocytes.</p> <p>Methods</p> <p>Currently anti-fragment antigen binding (Fab) conjugates are most widely used to determine the expression of CARs on gene-modified lymphocytes by flow cytometry. The limitations of these reagents are that many of them are not commercially available, generally they are polyclonal antibodies and often the results are inconsistent. In an effort to develop a simple universal flow cytometric method to detect the expression of CARs, we employed protein L to determine the expression of CARs on transduced lymphocytes. Protein L is an immunoglobulin (Ig)-binding protein that binds to the variable light chains (kappa chain) of Ig without interfering with antigen binding site. Protein L binds to most classes of Ig and also binds to single-chain antibody fragments (scFv) and Fab fragments.</p> <p>Results</p> <p>We used CARs derived from both human and murine antibodies to validate this novel protein L based flow cytometric method and the results correlated well with other established methods. Activated human PBLs were transduced with retroviral vectors expressing two human antibody based CARs (anti-EGFRvIII, and anti-VEGFR2), two murine antibody derived CARs (anti-CSPG4, and anti-CD19), and two humanized mouse antibody based CARs (anti-ERBB2, and anti-PSCA). Transduced cells were stained first with biotin labeled protein L followed by phycoerythrin (PE)-conjugated streptavidin (SA) and analyzed by flow cytometry. For comparison, cells were stained in parallel with biotin conjugated goat-anti-mouse Fab or CAR specific fusion proteins. Using protein L, all CAR transduced lymphocytes exhibited specific staining pattern ranging from 40 to 80% of positive cells (compared to untransduced cells) and staining was comparable to the pattern observed with anti-Fab antibodies.</p> <p>Conclusion</p> <p>Our data demonstrate the feasibility of employing Protein L as a general reagent for the detection of CAR expression on transduced lymphocytes by flow cytometry.</p

    A Study on Neerizhivu

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    Yugi munivar classified megarogam into 20 varieties in which Neerizhivu is one among them.Disease Neerizhivu come under pitha neer classification which is very specific and correlates with maturity onset diabetes mellitus i.e.non insulin dependent,which is a chronic metabolic disorder.Currently Neerizhivu is considered as one of the worst life style disorders faced by civilized world. The clinical diagnosis of all the cases of Neerizhivu were done on basis of signs and symptoms explained by yugi in siddha text yugi vaidhya chinthamani -800, Noi Naadal and Noi muthal Naadal and modern concept whereas need. The disease Neerizhivu has been thoroughly studied by selecting totally 40 patients were treated both OP & IP Department of pothu maruthuvam, Arignar Anna Hospital for period of 2 years. Patients were examined and investigated with Siddha and Modern concept. The medicine administered were, • Seerankottai thiravagam -10 drops with water twice daily after food. • Encouragingly the patients responded to the medicine showing gradual decrease in signs and symptoms. • No hypoglycemia was observed during the study. • HbA1(c) - 5% to 7% in 55% of cases shows the valuable management and control of Neerizhivu. • Seeronkottai thiravagam also significantly prevents associated symptoms like high blood pressure peripheral neuritis, cholesterol in the blood. • The drug shows no contra indications and side effect. • The drug also subjected to Pharmacological and toxicological tests in rat models. • The result revealed that the Seeronkottai thiravagam had very effective result. • There were no signs of toxicity as could be judged by the absence of undesirable clinical manifestations. • The biostatistical report of the clinical trial shows significant result. CONCLUSION: The drugs selected in this study are very effective and easily available. • Rasam (mercury) is very specific in treating Megarogam. The drug Seeronkottai is equal to rasam in the action, so this drug specifically treats Neerizhivu. • The drug acts as Kayakarpam. • Route of administration is easy. • As the drug is in Thiravagam from absorption is very quick. • The drug is a safe and effective one for Neerizhivu. • The drug has anti-hyperglycemia activity in rat model. • The drug is economically viable and without any untoward side effect. • The drug used to prepare the medicine is easily available herb, which even helps the lay man support from this disease. • The pharmacological study revealed that the Seerankottai thiravagam yield ed good results in rat models. • The statistical analysis proved significance of clinical improvement with the treatment. • As the result of this dissertation work is highly encouraging and the medicine being a cost effective one for the treatment of NEERIZHIVU, further detailed study will definitely fruitful to the society

    Magnetic enhancement of Co0.2_{0.2}Zn0.8_{0.8}Fe2_2O4_4 spinel oxide by mechanical milling

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    We report the magnetic properties of mechanically milled Co0.2_{0.2}Zn0.8_{0.8}Fe2_2O4_4 spinel oxide. After 24 hours milling of the bulk sample, the XRD spectra show nanostructure with average particle size ≈\approx 20 nm. The as milled sample shows an enhancement in magnetization and ordering temperature compared to the bulk sample. If the as milled sample is annealed at different temperatures for the same duration, recrystallization process occurs and approaches to the bulk structure on increasing the annealing temperatures. The magnetization of the annealed samples first increases and then decreases. At higher annealing temperature (∼\sim 10000^{0}C) the system shows two coexisting magnetic phases {\it i.e.}, spin glass state and ferrimagnetic state, similar to the as prepared bulk sample. The room temperature M\"{o}ssbauer spectra of the as milled sample, annealed at 3000^{0}C for different durations (upto 575 hours), suggest that the observed change in magnetic behaviour is strongly related with cations redistribution between tetrahedral (A) and octahedral (O) sites in the spinel structure. Apart from the cation redistribution, we suggest that the enhancement of magnetization and ordering temperature is related with the reduction of B site spin canting and increase of strain induced anisotropic energy during mechanical milling.Comment: 14 pages LaTeX, 10 ps figure

    Cationic exchange in nanosized ZnFe2O4 spinel revealed by experimental and simulated near-edge absorption structure

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    The non-equilibrium cation site occupancy in nanosized zinc ferrites (6-13 nm) with different degree of inversion (0.2 to 0.4) was investigated using Fe and Zn K-edge x-ray absorption spectroscopy XANES and EXAFS, and magnetic measurements. The very good agreement between experimental and ab-initio calculations on the Zn K-edge XANES region clearly show the large Zn2+(A)--Zn2+[B] transference that takes place in addition to the well-identified Fe3+[B]--Fe3+(A) one, without altering the long-range structural order. XANES spectra features as a function of the spinel inversion were shown to depend on the configuration of the ligand shells surrounding the absorbing atom. This XANES approach provides a direct way to sense cationic inversion in these spinel compounds. We also demonstrated that a mechanical crystallization takes place on nanocrystalline spinel that causes an increase of both grain and magnetic sizes and, simultaneously, generates a significant augment of the inversion.Comment: 5 pages, 5 eps figures, uses revtex4, corrected table

    Mössbauer and magnetic study of Co x Fe3−x O4 nanoparticles

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    Magnetic nanoparticles of cobalt ferrites Co x Fe3−x O4 (x = 1 or 2) have been obtained either by mechanical milling or thermal treatment of pre-prepared layered double hydroxide carbonate x-LDH–CO3. Mechanical milling of the 1-LDH–CO3 leads to the large-scale preparation of nearly spherical nanoparticles of CoFe2O4, the size of which (5 to 20 nm) is controlled by the treatment time. Core-shell structure with surface spin-canting has been considered for the nanoparticles formed to explain the observed hysteresis loop shift (from ZFC–FC) in the magnetic properties. Annealing treatment of the 2-LDH–CO3 below 673 K results in the formation of nearly spherical pure Co2FeO4 nanoparticles. At 673 K and above, the LDH decomposition leads to the formation of a mixture of both spinels phases Co2FeO4 and CoFe2O4, the amount of the latter increases with annealing temperature. Unusually high magnetic hardness characterized by a 22 kOe coercive field at 1.8 K has been observed, which reflects the high intrinsic anisotropy for Co2FeO4

    Inhibition of NF-ÎşB activation by 5-lipoxygenase inhibitors protects brain against injury in a rat model of focal cerebral ischemia

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    BACKGROUND: Stroke is one of the leading causes of death worldwide and a major cause of morbidity and mortality in the United States of America. Brain ischemia-reperfusion (IR) triggers a complex series of biochemical events including inflammation. Leukotrienes derived from 5-lipoxygenase (5-LOX) cause inflammation and are thus involved in the pathobiology of stroke injury. METHODS: To test the neuroprotective efficacy of 5-LOX inhibition in a rat model of focal cerebral IR, ischemic animals were either pre- or post-treated with a potent selective 5-LOX inhibitor, (N- [3-[3-(-fluorophenoxy) phenyl]-1-methyl-2-propenyl]-N-hydroxyurea (BW-B 70C). They were evaluated at 24 h after reperfusion for brain infarction, neurological deficit score, and the expression of 5-LOX. Furthermore, the mechanism and the anti-inflammatory potential of BW-B 70C in the regulation of nuclear factor kappa B (NF-ÎşB) and inflammatory inducible nitric oxide synthase (iNOS) were investigated both in vivo and in vitro. RESULTS AND DISCUSSION: Both pre- and post-treatment with BW-B 70C reduced infarctions and improved neurological deficit scores. Immunohistochemical study of brain sections showed IR-mediated increased expression of 5-LOX in the neurons and microglia. BW-B 70C down-regulated 5-LOX and inhibited iNOS expression by preventing NF-ÎşB activation. Two other structurally different 5-LOX inhibitors were also administered post IR: caffeic acid and 2, 3, 5-trimethyl-6- [12-hydroxy-5, 10-dodecadiynyl]-1, 4-benzoquinone (AA-861). As with BW-B 70C, they provided remarkable neuroprotection. Furthermore, in vitro, BW-B 70C inhibited lipopolysaccharide (LPS) mediated nitric oxide production, iNOS induction and NF-ÎşB activation in the BV2 microglial cell line. Treating rat primary microglia with BW-B70C confirmed blockage of LPS-mediated translocation of the p65 subunit of NF-ÎşB from cytosol to nucleus. CONCLUSION: The study demonstrates the neuroprotective potential of 5-LOX inhibition through down-regulation of NF-ÎşB in a rat model of experimental stroke

    High coercivity cobalt carbide nanoparticles processed via polyol reaction: A new permanent magnet material

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    Cobalt carbide nanoparticles were processed using polyol reduction chemistry that offers high product yields in a cost effective single-step process. Particles are shown to be acicular in morphology and typically assembled as clusters with room temperature coercivities greater than 4 kOe and maximum energy products greater than 20 KJ/m3. Consisting of Co3C and Co2C phases, the ratio of phase volume, particle size, and particle morphology all play important roles in determining permanent magnet properties. Further, the acicular particle shape provides an enhancement to the coercivity via dipolar anisotropy energy as well as offering potential for particle alignment in nanocomposite cores. While Curie temperatures are near 510K at temperatures approaching 700 K the carbide powders experience an irreversible dissociation to metallic cobalt and carbon thus limiting operational temperatures to near room temperature.Comment: Total 28 pages, 10 figures, and 1 tabl

    Changes in daily mental health service use and mortality at the commencement and lifting of COVID-19 'lockdown' policy in 10 UK sites: a regression discontinuity in time design.

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    OBJECTIVES: To investigate changes in daily mental health (MH) service use and mortality in response to the introduction and the lifting of the COVID-19 'lockdown' policy in Spring 2020. DESIGN: A regression discontinuity in time (RDiT) analysis of daily service-level activity. SETTING AND PARTICIPANTS: Mental healthcare data were extracted from 10 UK providers. OUTCOME MEASURES: Daily (weekly for one site) deaths from all causes, referrals and discharges, inpatient care (admissions, discharges, caseloads) and community services (face-to-face (f2f)/non-f2f contacts, caseloads): Adult, older adult and child/adolescent mental health; early intervention in psychosis; home treatment teams and liaison/Accident and Emergency (A&E). Data were extracted from 1 Jan 2019 to 31 May 2020 for all sites, supplemented to 31 July 2020 for four sites. Changes around the commencement and lifting of COVID-19 'lockdown' policy (23 March and 10 May, respectively) were estimated using a RDiT design with a difference-in-difference approach generating incidence rate ratios (IRRs), meta-analysed across sites. RESULTS: Pooled estimates for the lockdown transition showed increased daily deaths (IRR 2.31, 95% CI 1.86 to 2.87), reduced referrals (IRR 0.62, 95% CI 0.55 to 0.70) and reduced inpatient admissions (IRR 0.75, 95% CI 0.67 to 0.83) and caseloads (IRR 0.85, 95% CI 0.79 to 0.91) compared with the pre lockdown period. All community services saw shifts from f2f to non-f2f contacts, but varied in caseload changes. Lift of lockdown was associated with reduced deaths (IRR 0.42, 95% CI 0.27 to 0.66), increased referrals (IRR 1.36, 95% CI 1.15 to 1.60) and increased inpatient admissions (IRR 1.21, 95% CI 1.04 to 1.42) and caseloads (IRR 1.06, 95% CI 1.00 to 1.12) compared with the lockdown period. Site-wide activity, inpatient care and community services did not return to pre lockdown levels after lift of lockdown, while number of deaths did. Between-site heterogeneity most often indicated variation in size rather than direction of effect. CONCLUSIONS: MH service delivery underwent sizeable changes during the first national lockdown, with as-yet unknown and unevaluated consequences
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