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1.
J Chem Phys ; 160(20)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38804491

RESUMO

The outstanding catalytic property of cerium oxide (CeO2) strongly depends on the polaron formation due to the oxygen vacancy (V̈O) defect and Ce4+ to Ce3+ transformation. Temperature plays an important role in the case of polaron generation in CeO2 and highly influences its electrical transport properties. Therefore, a much needed attention is required for detailed understanding of the effect of temperature on polaron formation and oxygen vacancy migration to get an idea about the improvement in the redox property of ceria. In this work, we have probed the generation of polarons in CeO2 thin-film deposited on a silicon (Si) substrate using the resonance photoemission spectroscopy (RPES) study. The RPES data show an increase in polaron density at the substrate-film interface of the thermally annealed film, indicating the formation of an interfacial Ce2O3 layer, which is, indeed, a phase change from the cubic to hexagonal structure. This leads to a modified electronic band structure, which has an impact on the capacitance-voltage (C-V) characteristics. This result nicely correlates the microscopic property of polarons and the macroscopic transport property of ceria.

2.
J Synchrotron Radiat ; 30(Pt 2): 449-456, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36891859

RESUMO

The feasibility of X-ray absorption fine-structure (XAFS) experiments of ultra-dilute metalloproteins under in vivo conditions (T = 300 K, pH = 7) at the BL-9 bending-magnet beamline (Indus-2) is reported, using as an example analogous synthetic Zn (0.1 mM) M1dr solution. The (Zn K-edge) XAFS of M1dr solution was measured with a four-element silicon drift detector. The first-shell fit was tested and found to be robust against statistical noise, generating reliable nearest-neighbor bond results. The results are found to be invariant between physiological and non-physiological conditions, which confirms the robust coordination chemistry of Zn with important biological implications. The scope of improving spectral quality for accommodation of higher-shell analysis is addressed.


Assuntos
Metaloproteínas , Síncrotrons , Metaloproteínas/química , Raios X , Radiografia , Índia
3.
Phys Chem Chem Phys ; 25(4): 3072-3082, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36620902

RESUMO

The optical performance of low-bilayer-thickness metallic multilayers (ML) can be improved significantly by limiting the intermixing of consecutive layers at the interfaces. Barrier layers are supposed to exhibit a decisive role in controlling diffusion across the interfaces. The element-specific grazing incidence extended X-ray absorption fine structure technique using synchrotron radiation has been used in conjunction with grazing incidence X-ray reflectivity and diffuse X-ray scattering measurements to study the impact of the two most common barrier layers, viz., C and B4C, at the interfaces of Cr/Sc MLs. The diffusion propagation is reduced by both the barrier layers; however, it is found that the improvement is more significant with the B4C barrier layer. It is seen that C forms an intermixed layer with Sc and leads to carbide formation at the interface, which then acts as shielding and prevents further interdiffusion, while B4C hardly penetrates into Sc and stops the overlap between Sc and Cr directly by wetting the corresponding interface. Thus, the above measurements reveal crucial and precise information regarding the elemental diffusion kinetics at the interfaces of Cr/Sc MLs in a non-destructive way, which is very important for technological applications of these MLs as X-ray optical devices.

4.
Phys Chem Chem Phys ; 25(32): 21479-21491, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37539659

RESUMO

In recent times, ultra-thin films of hafnium oxide (HfO2) have shown ferroelectricity (FE) attributed to the orthorhombic (o) phase of HfO2 with space group Pca21. This polar o-phase could be stabilized in the doped thin film of the oxide. In the present work, both polar and non-polar o-phases of HfO2 could be stabilized in Gd-doped bulk polycrystalline HfO2. Rietveld analysis of XRD data shows that the relative population of o-phases in the presence of the monoclinic (m) phase of HfO2 increases with increasing Gd-content. The local environment around the host atom has been investigated by time differential perturbed angular correlation (TDPAC) spectroscopy, synchrotron based X-ray near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) measurements showed a reduction in grain size with increasing Gd-dopant indicating a solute drag effect. It could be established that the segregation of the Gd-dopant in the grain boundary is a thermodynamically favorable process and the solute drag effect plays an important role in nucleation of the o-phase in bulk HfO2. Stabilization of Gd in both Pbca and Pca21 phases of HfO2 was supported by defect formation energy calculations using density functional theory (DFT). The present study has important implications in future applications of HfO2 in ferroelectric devices and in understanding the role of dopants in stabilizing the o-phase of HfO2 in the bulk.

5.
J Postgrad Med ; 69(4): 215-220, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37357486

RESUMO

Single parent adoption (SPA) is a relatively new construct worldwide and in India. The Ministry of Women and Child Development, Government of India, has laid down criteria for adoption in general and SPA in particular, in conjunction with the Juvenile Justice Act (Care and Protection of Children), 2015. There is scant literature on this topic of SPA, more so in India, that looks into the various psychological nuances of SPA from a mental health professional's (MHP) perspective. This review paper aims to assess SPA from the perspective of a MHP that will focus on its various legal nuances as well as the psychological connotations attached to it. For this, a search strategy was employed that included a thorough literature search from two databases (PubMed and Google Scholar) with relevant keywords related to the topic. The various legal issues pertaining to SPA in the current scenario, the psychological issues and challenges faced by single parents, the behavioral outcomes of adoptees who are adopted by single parents, and ways to deal with the various obstacles of SPA are discussed.


Assuntos
Saúde Mental , Pais Solteiros , Criança , Humanos , Feminino , Adoção/psicologia , Índia
6.
Kathmandu Univ Med J (KUMJ) ; 21(81): 58-63, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37800427

RESUMO

Background Although Nephrolithiasis is a common condition caused by a wide variety of metabolic or environmental disturbances, its being one of the major factor of morbidity. Incidence of kidney stone disease (KSD) is highly affected by metabolic disorders and change in blood pressure and glucose. Objective To find out association of different biochemical and hemodynamic parameters with various glycemic status and hypertension in kidney stone disease. Method A cross sectional study was conducted in patients diagnosed as nephrolithiasis by using re¬nal ultrasonography and underwent nephrectomy between January 2019 to January 2021 in Shahid Dharmabhakta National Transplant Centre (SDNTC). A total of 100 subjects with 60 male and 40 females were enrolled. Glycemic status was categorized based on criteria of American Diabetes Association (ADA) and hypertension was defined as BP ≥ 140/90 mm Hg in right arm supine position. All biochemical and hemodynamic profile was carried out following standard protocol. Result Out of 100 patients enrolled, pre-diabetes accounted for 31% followed by diabetes (4%). However, hypertension comprised of 66% in total subjects. Serum urea, cholesterol and triglyceride level were found to be increased by 84.6%, 67.7% and 64.7% respectively in diabetes followed by increase of 3.9%, 19.5% and 3.1% respectively in prediabetes when compared to normal glycemic condition in nephrolithiasis subjects. Serum fasting blood glucose, creatinine and uric acid level was observed significantly higher (p=0.003, p=0.004, p < 0.001 respectively) in hypertensive patients. Duration of hospital stay was also seen positively correlated with hypertension. Conclusion Not only diabetes, prediabetes also manifests the increased risk of kidney stone disease along with hypertension. There is significant impairment in renal function and lipid profile based on diabetes mellitus and hypertension. Early identifying these systemic diseases, different biochemical and hemodynamic parameters and proper treatment accordingly may minimize risk and prevent serious complication in these patients.


Assuntos
Diabetes Mellitus Tipo 2 , Diabetes Mellitus , Hipertensão , Cálculos Renais , Estado Pré-Diabético , Feminino , Humanos , Masculino , Diabetes Mellitus Tipo 2/complicações , Estado Pré-Diabético/complicações , Estudos Transversais , Hipertensão/complicações , Cálculos Renais/complicações , Cálculos Renais/epidemiologia , Pressão Sanguínea
7.
BJOG ; 129(4): 664-670, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34524725

RESUMO

OBJECTIVE: To compare the incidence of systemic conditions between women who had surgical treatment for stress incontinence with mesh and without mesh. DESIGN: National cohort study. SETTING: English National Health Service. POPULATION: Women with no previous record of systemic disease who had first-time urinary incontinence surgery between 1 January 2006 and 31 December 2013, followed up to the earliest of 10 years or 31 March 2019. METHODS: Competing-risks regression was used to estimate hazard ratios (HR), adjusted for patient characteristics, with HR > 1 indicating increased incidence following mesh surgery. MAIN OUTCOME MEASURES: First postoperative admission with a record of autoimmune disease, fibromyalgia or myalgic encephalomyelitis up to 10 years following the first incontinence procedure. RESULTS: The cohort included 88 947 women who had mesh surgery and 3389 women who had non-mesh surgery. Both treatment groups were similar with respect to age, socio-economic deprivation, comorbidity and ethnicity. The 10-year cumulative incidence of autoimmune disease, fibromyalgia or myalgic encephalomyelitis was 8.1% (95% CI 7.9-8.3%) in the mesh group and 9.0% (95% CI 8.0-10.1%) in the non-mesh group (adjusted HR 0.89, 95% CI 0.79-1.01; P = 0.07). A sensitivity analysis including only autoimmune diseases as an outcome returned a similar result. CONCLUSIONS: These findings do not support claims that synthetic mesh slings cause systemic disease. TWEETABLE ABSTRACT: No evidence of increased risk of systemic conditions after stress incontinence treatment with a mesh sling.


Assuntos
Slings Suburetrais/estatística & dados numéricos , Telas Cirúrgicas/efeitos adversos , Incontinência Urinária por Estresse/cirurgia , Adulto , Idoso , Doenças Autoimunes/etiologia , Estudos de Coortes , Síndrome de Fadiga Crônica/etiologia , Feminino , Fibromialgia/etiologia , Humanos , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Medição de Risco , Slings Suburetrais/efeitos adversos , Incontinência Urinária por Estresse/epidemiologia
8.
Phys Chem Chem Phys ; 24(7): 4415-4424, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35113109

RESUMO

The thin films of Ni and Bi are known to form NiBi3 and NiBi compounds spontaneously at the interface, which become superconducting below 4.2 K and show ferromagnetism either intrinsically or due to Ni impurities. Formation of NiBi3 and NiBi is a slow diffusion reaction, which means the local environment around Ni and Bi atoms may vary with time and temperature. In this report, we assess the feasibility of using X-ray Absorption Spectroscopy (XAS) as a tool to track the changes in local bonding environment in NiBi3 and NiBi. Thermal annealing at temperatures up to 500 °C was used to induce changes in the local environment in NiBi3 system. Consequent decomposition of NiBi3 into NiO and Bi has been tracked through changes in structural and magnetization behavior, which matched well with the findings of XAS. In addition, the magnetic hysteresis measurements indicated that NiO should be the dominant phase when NiBi3 is annealed at 500 °C. This was corroborated from XAS and was found to be >90%. The shift in K-edge of Ni in annealed samples was attributed to increasing charge state on Ni atom, which was ascertained by Bader charge analysis using Density Functional Theory (DFT). This study correlating macroscopic properties of NiBi3 with local bonding environment of the system indicates that XAS can be a very reliable tool for studying dynamics of diffusion in the NiBi3 system.

9.
Phys Chem Chem Phys ; 24(30): 18255-18264, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35876232

RESUMO

Intrinsic defects created by chemically inert gas (Xe) ion implantation in vertically grown ZnO nanorods are studied by optical and X-ray absorption spectroscopy (XAS). The surface defects produced due to dynamic sputtering by ion beams control the fraction of O and Zn with ion fluence, which helps in tuning the optoelectronic properties. The forbidden Raman modes related to Zn interstitials and oxygen vacancies are observed because of the weak Fröhlich interaction, which arises due to disruption of the long-range lattice order. The evolution of the lattice disorder is identified by O K-edge and Zn K-edge scans of XAS. The hybridization strength between the O 2p and Zn 4p states increases with ion fluence and modulates the impact of intrinsic defects. The ion irradiation induced defects also construct intermediate defects bands which reduce the optical bandgap. Density functional theory (DFT) calculations are used to correlate the experimentally observed trend of bandgap narrowing with the origin of electronic states related to Zn interstitial and O vacancy defects within the forbidden energy gap in ZnO. Our finding can be beneficial to achieve enhanced conductivity in ZnO by accurately varying the intrinsic defects through ion irradiation, which may work as a tuning knob to control the optoelectronic properties of the system.

10.
Cereb Cortex ; 31(2): 933-948, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33009551

RESUMO

A better understanding of genetic influences on early white matter development could significantly advance our understanding of neurological and psychiatric conditions characterized by altered integrity of axonal pathways. We conducted a genome-wide association study (GWAS) of diffusion tensor imaging (DTI) phenotypes in 471 neonates. We used a hierarchical functional principal regression model (HFPRM) to perform joint analysis of 44 fiber bundles. HFPRM revealed a latent measure of white matter microstructure that explained approximately 50% of variation in our tractography-based measures and accounted for a large proportion of heritable variation in each individual bundle. An intronic SNP in PSMF1 on chromosome 20 exceeded the conventional GWAS threshold of 5 x 10-8 (p = 4.61 x 10-8). Additional loci nearing genome-wide significance were located near genes with known roles in axon growth and guidance, fasciculation, and myelination.


Assuntos
Estudo de Associação Genômica Ampla , Substância Branca/ultraestrutura , Axônios/fisiologia , Cromossomos Humanos Par 20/genética , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Lactente , Recém-Nascido , Masculino , Bainha de Mielina/fisiologia , Fibras Nervosas/fisiologia , Fenótipo , Polimorfismo de Nucleotídeo Único , Complexo de Endopeptidases do Proteassoma/genética , Análise de Regressão
11.
J Vector Borne Dis ; 59(2): 145-153, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36124480

RESUMO

We aimed to assess the effect of gamma radiation on the expression of heat shock proteins Hsc70 and Hsp83 in Aedes aegypti. Adult males were irradiated with 50Gy of gamma radiation, and changes in the expression of proteins in SDS-PAGE gel bands corresponding to molecular weights ~60-75kDa and ~80-95kDa were analyzed at two different time points 6 and 12-hour post-irradiation, using a temporal mass spectrometry based semi-quantitative analysis. A 2-3-fold increase was observed in both proteins Hsc70 and Hsp83, at both time points. In addition, the experiment also revealed the overexpression of several other molecules such as Arginine Kinase - known to be upregulated in certain insects during stress, Esterase B1- implicated in insecticide resistance, and also down-regulation of the 26S proteasome non-ATPase regulatory subunit 1 and ubiquitin-activating enzyme E1 - both known to be involved in ubiquitin-mediated protein degradation. The results taken together with existing data on Hsp83 and Hsc70, indicate that these proteins may enhance the survival of Ae. aegypti following gamma radiation and could serve as molecular markers for the detection of radiation-induced stress.


Assuntos
Aedes , Arginina Quinase , Dengue , Aedes/genética , Animais , Arginina Quinase/metabolismo , Esterases/metabolismo , Esterases/farmacologia , Raios gama , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Proteínas de Choque Térmico/farmacologia , Masculino , Enzimas Ativadoras de Ubiquitina/metabolismo , Enzimas Ativadoras de Ubiquitina/farmacologia , Ubiquitinas/metabolismo , Ubiquitinas/farmacologia
12.
Environ Monit Assess ; 194(11): 837, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36169769

RESUMO

In the current survey, different hydrogeochemical processes governing the geochemistry of aquifers, the usefulness of groundwater for regular consumption, and agricultural purposes were evaluated around the Tummalapalle area. One hundred forty-four borehole locations were chosen to characterize the major physicochemical components of the aquifer water. The analysis results of pH inferred that the groundwater is nominally acidic to basic, and pH ranged from 6.6 to 8.4. The average concentrations of TDS, Ca2+, Mg2+, total hardness (TH), HCO3-, and total alkalinity (TA) are within the allowable limits of potable water quality as prescribed by the Bureau of Indian Standards (BIS) and WHO. However, the average concentrations of Na+, K+, Cl-, and SO42- were all below the permissible limit. All samples were analyzed with the help of Piper and Chadha charts to determine the dominant hydrogeochemical components of groundwater. The dominance of cations in groundwater in this region is in the sequence of Ca2+ > Na+ > Mg2+ > K+, followed by anions HCO3- > Cl- > SO42-. The Gibbs plot analysis suggested the predominance of rock aquifer interaction as the major hydrogeochemical process governing groundwater geochemistry in this region. The water quality index (WQI) of all groundwater samples in the Tummalapalle region was estimated, with 55% of the samples being potable grade. The different irrigation indices were analyzed for the groundwater samples to estimate their desirability for agriculture. The maximum number of water samples was found to be well-suited for cultivation.


Assuntos
Água Potável , Água Subterrânea , Poluentes Químicos da Água , Ânions/análise , Cátions/análise , Água Potável/análise , Monitoramento Ambiental/métodos , Água Subterrânea/química , Índia , Poluentes Químicos da Água/análise , Qualidade da Água
13.
Kathmandu Univ Med J (KUMJ) ; 20(79): 346-350, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37042378

RESUMO

Background Ultrasound (USG) with Doppler examination of intrarenal vessels is the imaging modality of choice employed in patients with renal failure and is commonly performed early in the clinical course. The pulsatility index (PI) and the resistive index (RI) of downstream renal artery have been found to correlate with renal vascular resistance, filtration fraction and effective renal plasma flow in chronic renal failure. Pathological process in any tissues alters their elastic properties which can be assessed non-invasively through newer technique like elastography. Objective To correlate the findings obtained by sonoelastographic, doppler and histopathological studies in chronic kidney disease patients. Method Study was done in 146 patients referred to Department of Radiodiagnosis and Imaging, TUTH for native renal biopsy. Renal sonographic morphology (length, echogenicity, cortical thickness), Sonoelastography (Young's modulus) and Doppler parameters (peak systolic velocity, resistive index) were assessed. The grading of estimated GFR (eGFR) was calculated based on chronic kidney disease (CKD) criteria. Result Among 146 patients, 63 (43.2%) were females and 83 (56.8%) were males. Maximum patients were in age group of 41-50 years (25.3%) followed by age group 51-60 years (24%). Mean age of patient was 42.06±14.70 for males and 39.57±12.54 females. Maximum mean Young's modulus was seen in eGFR stage G1 with 46.57±19.51 kPa followed by in stage G3a with 36.46±10.01 kPa and observed to be statistically non-significant (p=0.172). However, statistical significance difference was noted between the resistive index and elastographic measurement of Young's modulus (r=0.462, p=0.0001). Minimum mean cortical thickness was seen in eGFR stage G5 with 4.42±1.48 mm followed by stage G4 with 5.57±1.24 mm (p= 0.0001). Cortical thickness is decreasing as eGFR stage was increasing in our study (p=0.0001). Resistive index is increasing with decrease in renal size (r=-0.202, p=0.015). Conclusion Ultrasonography along with doppler study and elastography have limited role in diagnosing the pathology of chronic kidney disease, however, it has significant role in the disease progression.


Assuntos
Insuficiência Renal Crônica , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Centros de Atenção Terciária , Insuficiência Renal Crônica/patologia , Rim , Artéria Renal/diagnóstico por imagem , Ecocardiografia Doppler
14.
J Synchrotron Radiat ; 28(Pt 2): 480-489, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33650560

RESUMO

The germanium auto-diffusion effects on the inter-atomic distance between the nearest neighbors of the Ga atom in GaP epilayers are investigated using high-resolution X-ray diffraction (HRXRD) and X-ray absorption spectroscopy. The GaP layers grown on Ge (111) are structurally coherent and relaxed but they show the presence of residual strain which is attributed to the auto-diffusion of Ge from the results of secondary ion mass spectrometry and electrochemical capacitance voltage measurements. Subsequently, the inter-atomic distances between the nearest neighbors of Ga atom in GaP are determined from X-ray absorption fine-structure spectra performed at the Ga K-edge. The estimated local bond lengths of Ga with its first and second nearest neighbors show asymmetric variation for the in-plane and out-of-plane direction of GaP/Ge(111). The magnitude and direction of in-plane and out-of-plane microscopic residual strain present in the GaP/Ge are calculated from the difference in bond lengths which explains the presence of macroscopic residual tensile strain estimated from HRXRD. Modified nearest neighbor configurations of Ga in the auto-diffused GaP epilayer are proposed for new possibilities within the GaP/Ge hetero-structure, such as the conversion from indirect to direct band structures and engineering the tensile strain quantum dot structures on (111) surfaces.

15.
Phys Chem Chem Phys ; 23(10): 6051-6061, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33683228

RESUMO

The structural changes of Fe3O4 nanoparticle electrodes in Li ion batteries during charging-discharging cycles have been investigated using in situ X-ray absorption spectroscopy (XAS). Chemometric methods viz., Principal Component Analysis (PCA) and Multivariate Curve Resolution-Alternate Least Square (MCR-ALS) have been used for analysis of the in situ XANES data during the charge-discharge cycle, which help to identify the various species formed during the lithiation-delithiation of Fe3O4. The concentration variation of the different species has also been determined and the detailed intercalation-conversion mechanism of the Fe3O4 electrodes during the first discharge has been established. Subsequently, the first charge and second discharge cycles were also studied to apprehend the difference in redox reaction between the first discharge and subsequent cycles. The above studies clearly identify the four species involved in the whole intercalation-conversion process of Fe3O4 electrode of a Li ion battery and also indicate the irreversibility of the conversion reaction in subsequent cycles which may be one of the reasons for capacity fading of these electrodes. The above results have also been corroborated with density functional theory (DFT)based ab inito calculations.

16.
Phys Chem Chem Phys ; 23(30): 16258-16267, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34309608

RESUMO

The recent observation of ferroelectricity in ultra thin films of hafnium oxide (HfO2) has been attributed to the orthorhombic (o) phase of HfO2 with space group Pca21. Although this oxide is polymorphic in nature, this polar o-phase is known to be stabilized in the doped thin film oxide. The objective of the present experiment is to stabilize the o-phases in La doped bulk polycrystalline HfO2 and investigate their evolution with the doping concentration through Time Differential Perturbed Angular Correlation (TDPAC), X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) measurements. The present work reports the presence of both the polar Pca21 phase and the antipolar Pbca phase at different La-concentrations. Two o-phases of HfO2 with space groups Pca21 and Pbca, difficult to distinguish by other complimentary methods, could be unambiguously identified by utilizing the atomic scale sensitivity of the electric field gradient (EFG) embedded in TDPAC spectroscopy. The determination of the oxidation state and the local environment of La-atoms by XANES and EXAFS measurements illuminates the microscopic role of the dopant in stabilizing the o-phase. The "solute drag model" proposes a critical crystallite size for the nucleation of the o-phase in bulk HfO2 and explains the role of the La-dopant in stabilizing the o-phase. Thus the present study shows the possibility of stabilizing the polar o-phase and hence attaining ferroelectricity in bulk HfO2 to augment the scope of future application for this ferroelectric device.

17.
J Synchrotron Radiat ; 27(Pt 4): 988-998, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33566008

RESUMO

The static focusing optics of the existing energy-dispersive XAFS beamline BL-8 have been advantageously exploited to initiate diamond anvil cell based high-pressure XANES experiments at the Indus-2 synchrotron facility, India. In the framework of the limited photon statistics with the 2.5 GeV bending-magnet source, limited focusing optics and 4 mm-thick diamond windows of the sample cell, a (non-trivial) beamline alignment method for maximizing photon statistics at the sample position has been designed. Key strategies include the selection of a high X-ray energy edge, the truncation of the smallest achievable focal spot size to target size with a slit and optimization of the horizontal slit position for transmission of the desired energy band. A motor-scanning program for precise sample centering has been developed. These details are presented with rationalization for every step. With these strategies, Nb K-edge XANES spectra for Nb2O5 under high pressure (0-16.9 GPa) have been generated, reproducing the reported spectra for Nb2O5 under ambient conditions and high pressure. These first HPXANES results are reported in this paper. The scope of extending good data quality to the EXAFS range in the future is addressed. This work should inspire and guide future high-pressure XAFS experiments with comparable infrastructure.

18.
Theor Appl Genet ; 133(9): 2685-2694, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32507913

RESUMO

KEY MESSAGE: A novel leaf rust resistance gene, LrM, introgressed from Aegilops markgrafii and mapped on chromosome 2AS using SSR- and SNP-based PCR markers will aid in broadening the genetic base of rust resistance in wheat. A new leaf rust resistance gene tentatively named LrM was introgressed from the diploid non-progenitor species Ae. markgrafii (2n = 2x = 14, genome CC) into common wheat using the nulli-5B mechanism. The introgression line ER9-700 showed a high degree of resistance against a wide spectrum of Puccinia triticina pathotypes. Genetic analysis was performed using the F1, F2, F2:3 and BC1F1 generations derived from the cross ER9-700/Agra Local. The results showed a single dominant gene for leaf rust resistance. The resistance gene LrM was mapped on chromosome arm 2AS using SSR- and SNP-based PCR markers. Preliminary mapping with SSR markers in the F2:3 population from the cross ER9-700/Agra Local identified two SSR markers flanking the LrM. SNPs were identified in the genomic region flanked by SSR markers, and SNP-based PCR markers were developed to construct the final map. Three SNP-based PCR markers co-segregated and mapped closest to the resistance gene at a distance of 2 cM. The gene LrM was distinguished from all the other genes designated and mapped on chromosome arm 2AS by molecular markers and rust reaction. All five markers used in the mapping amplified identical alleles in the donor Ae. markgrafii accession and introgression line ER9-700. The chromosomal location and rust reaction suggest that LrM is a novel leaf rust resistance gene that may be useful in broadening the genetic base of leaf rust resistance in wheat.


Assuntos
Aegilops/genética , Genes de Plantas , Doenças das Plantas/genética , Triticum/genética , Basidiomycota/patogenicidade , Mapeamento Cromossômico , Cromossomos de Plantas , Cruzamentos Genéticos , Repetições de Microssatélites , Fenótipo , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Triticum/microbiologia
19.
Clin Radiol ; 75(9): 710.e1-710.e4, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32405081

RESUMO

Coronavirus disease 2019 has spread to every inhabited continent in the world. So far, plain radiography and computed tomography have been the mainstay of imaging methods used. The present analytical paper on the role of point-of-care lung ultrasound in this pandemic examines its diagnostic accuracy, clinical utility, and physical practicality in the intensive care unit.


Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico por imagem , Cuidados Críticos/métodos , Pneumonia Viral/diagnóstico por imagem , Sistemas Automatizados de Assistência Junto ao Leito , Ultrassonografia/métodos , COVID-19 , Humanos , Pulmão/diagnóstico por imagem , Pandemias , SARS-CoV-2
20.
J Synchrotron Radiat ; 26(Pt 1): 137-144, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30655478

RESUMO

This article describes the setting up of a facility on the energy-scanning EXAFS beamline (BL-09) at RRCAT, Indore, India, for operando studies of structure-activity correlation during a catalytic reaction. The setup was tested by operando X-ray absorption spectroscopy (XAS) studies performed on a Co-based catalyst during the Fischer-Tropsch reaction to obtain information regarding structural changes in the catalyst during the reaction. Simultaneous gas chromatography (GC) measurements during the reaction facilitate monitoring of the product gases, which in turn gives information regarding the activity of the catalyst. The combination of XAS and GC techniques was used to correlate the structural changes with the activity of the catalyst at different reaction temperatures. The oxide catalyst was reduced to the metallic phase by heating at 400°C for 5 h under H2 at ambient pressure and subsequently the catalytic reaction was studied at four different temperatures of 240, 260, 280 and 320°C. The catalyst was studied for 10 h at 320°C and an attempt has been made to understand the process of its deactivation from the XANES and EXAFS results.

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