Demystification of luminescence properties and the near imperceptible thermal quenching of Sm3+-doped tungstate phosphors.

Ultra-high thermally stable Ca2MgWO6:xSm3+ (x = 0.5, 0.75, 1, 1.25, and 1.5 mol%) double perovskite phosphors were synthesized through solid-state reaction method. Product formation was confirmed by comparing the X-ray diffraction (XRD) patterns of the phosphors with the standard reference file. The structural, morphological, thermal, and optical properties of the prepared phosphor were examined in detail using XRD, Fourier transform infrared spectra, scanning electron microscopy, diffused reflectance spectra, thermogravimetric analysis (TGA), photoluminescence emission, and temperature-dependent PLE (TDPL). It was seen that the phosphor exhibited emission in the reddish region for the near-ultraviolet excitation with moderate Colour Rendering Index values and high colour purity. The optimized phosphor (x = 1.25 mol%) was found to possess a direct optical band gap of 3.31 eV. TGA studies showed the astonishing thermal stability of the optimized phosphor. Additionally, near-zero thermal quenching was seen in TDPL due to elevated phonon-assisted radiative transition. Furthermore, the anti-Stokes and Stokes emission peaks were found to be sensitive toward the temperature change and followed a Boltzmann-type distribution. All these marked properties will make the prepared phosphors a suitable candidate for multifield applications and a fascinating material for further development.

Development of enduring interstitial defects in Mg-doped CuO thin films.

Doping is one of the easiest methods to enhance the properties of semiconducting thin films. This work presents a systematic study of the influence of Mg doping on the optoelectronic properties of copper oxide (CuO) thin films prepared by spray pyrolysis. The pristine and doped films were prepared on glass substrates at an optimized temperature of 350 °C and a precursor solution concentration of 0.15 M while the Mg doping concentration was varied between 2 and 10 at%. The properties of the prepared films were studied in detail by using various characterization techniques such as X-ray diffraction, field emission scanning electron microscopy, Raman and photoluminescence, X-ray photoelectron spectroscopy and Hall measurement. The results suggest that oxygen interstitial (Oi) defects were enhanced upon doping which has influenced the properties of the film. The size of the crystallites reduced, and the band gap widened after doping. In addition, comprehensive density functional theory analyses have been conducted to gain a thorough understanding of the impact of impurity (i.e., doping/interstitial) atoms on the optical and electrical characteristics of CuO. This study shows that Oi defects improved the conductivity and enhanced the carrier concentration leading to an improvement in the electrical properties of the films.

Observation of positive trions in α-MoO3/MoS2 van der Waals heterostructures.

Mono-layer transition metal dichalcogenides (TMDCs) have emerged as an ideal platform for the study of many-body physics. As a result of their low dimensionality, these materials show a strong Coulomb interaction primarily due to reduced dielectric screening that leads to the formation of stable excitons (bound electron-hole pairs) and higher order excitons, including trions, and bi-excitons even at room temperature. van der Waals (vdW) heterostructures (HSs) of TMDCs provide an additional degree of freedom for altering the properties of 2D materials because charge carriers (electrons) in the different atomically thin layers are exposed to interlayer coupling and charge transfer takes place between the layers of vdW HSs. Astoundingly, it leads to the formation of different types of quasi-particles. In the present work, we report the synthesis of vdW HSs, i.e., α-MoO3/MoS2, on a 300 nm SiO2/Si substrate and investigate their temperature-dependent photoluminescence (PL) spectra. Interestingly, an additional PL peak is observed in the case of the HS, along with A and B excitonic peaks. The emergence of a new PL peak in the low-energy regime has been assigned to the formation of a positive trion. The formation of positive trions in the HS is due to the high work function of α-MoO3, which enables the spontaneous transit of electrons from MoS2 to α-MoO3 and injection of holes into the MoS2 layer. In order to confirm charge transfer in the α-MoO3/MoS2 HS, systematic power and wavelength-dependent Raman and PL studies, as well as first-principle calculations using Bader charge analysis, have been carried out, which clearly validate our mechanism. We believe that this study will provide a platform towards the integration of vdW HSs for next-generation excitonic devices.

Influence of native defects on magneto-optoelectronic properties ofα-MoO3.

Semiconducting oxides possess a variety of intriguing electronic, optical, and magnetic properties, and native defects play a crucial role in these systems. In this study, we study the influence of native defects on these properties ofα-MoO3using the first-principles density functional theory calculations. From the formation energy calculations, it is concluded that Mo vacancies are difficult to form in the system, while O and Mo-O co-vacancies are energetically quite favorable. We further find that vacancies give rise to mid-gap states (trap states) that remarkably affect the magneto-optoelectronic properties of the material. Our calculations indicate that a single Mo vacancy leads to half-metallic behavior, and also induces a large magnetic moment of 5.98µB. On the other hand, for the single O vacancy case, the band gap disappears completely, but the system remains in a non-magnetic state. For Mo-O co-vacancies of two types considered in this work, a reduced band gap is found, along with an induced magnetic moment of 2.0µB. Furthermore, a few finite peaks below the main band edge are observed in the absorption spectra of configurations with Mo and O vacancies, while they are absent in the Mo-O co-vacancies of both types, just like in the pristine state. From theab-initiomolecular dynamics simulations, stability and sustainability of induced magnetic moment at room temperate is verified. Our findings will enable the development of defect strategies that maximize the functionality of the system and further help in designing highly efficient magneto-optoelectronic and spintronic devices.

Prevalence and clinical correlates of co-morbid attention deficit hyperactivity disorder in euthymic adults with bipolar disorder: A cross-sectional study.

Background: Bipolar disorders (BDs) are co-morbid with attention deficit hyperactivity disorder (ADHD), making diagnosis and management more difficult and associated with poorer outcomes. So, this study was planned to find the prevalence and clinical implication of co-morbid ADHD in BD. Materials and Methods: In this cross-sectional study, a total of 110 euthymic BD patients were taken. They were screened for childhood ADHD symptoms and adult ADHD symptoms using the Wender Utah Rating Scale for ADHD and Adult ADHD Self-Report Screening Scale for DSM-5. Those were divided into three groups: Group A included BD patients without ADHD, Group B included bipolar patients with co-morbid adult ADHD (BD-aADHD), and Group C included bipolar patients who had a diagnosis of childhood ADHD (BD-cADHD). Results: The ADHD prevalence of 27% was found in bipolar patients. The age of onset of an episode of BD was significantly earlier and the total duration of illness was significantly higher in BD-aADHD and BD-cADHD compared to the BD without ADHD. The BD-aADHD and BD-cADHD groups showed a significantly higher number of total, manic and major depressive episodes as compared to the BD without ADHD group. BD-aADHD showed a significant greater number of hypomanic episodes as compared to BD without ADHD. Conclusions: The present study concludes that ADHD is a lifetime co-morbid condition in adults with BD. These patients have a more chronic and disabling course of BD which underscores the need to understand the potential benefit of controlling ADHD symptoms in this population.

User Perception of Telephone-Based Telepsychiatry Consultation: A Cross-Sectional Survey.

Objective: To assess user perception regarding different aspects of the telepsychiatry process.Methods: This cross-sectional survey study was conducted between July and September 2020 with follow-up patients attending teleconsultation at a tertiary care center (N = 108). The online survey included questions about the user's experience such as the appointment process and different aspects of teleconsultation, as well as perceived benefits, difficulties experienced, and suggestions for improvement. The sociodemographic and clinical data were retrieved from the electronic record.Results: The majority of patients expressed satisfaction with teleconsultation. The patients who were living far from the center (> 100 km) and those with psychotic illness favored telepsychiatry. Patients with nonpsychotic illnesses reported significantly less satisfaction with counseling in teleconsultation.Conclusions: The findings substantiate the acceptance of telepsychiatry services and emphasize the need for a tailor-made hybrid form of consultation as per the patient's profile.

Mutation rate evaluation at 21 autosomal STR loci: Paternity testing experience.

The short tandem repeats (STRs) or microsatellites are used for paternity testing and these sequences mutate more rapidlythanbulkDNAsequences. A total of 746 paternity cases were analysed to understand the mutation rate of 21 autosomal STR loci. We identified 41 mutations in 11 STR Loci with a maximum at SE33. No mutations occurred in the remaining 10 STR loci. The overall average mutation rate was estimated as 0.004523 and the estimated locus-specific mutation rate varied between 0.001214 and 0.016990. Among these 90.24% was accounted for single-step mutation, 2.44% for two steps, and 7.32 % for three or muti steps. The obtained data is crucial and could be helpful for ensuring the accuracy of DNA testing and interpretation.

Development and validation of novel kit for quantification of SARS-CoV-2 antibodies on clinical samples.

Since the pandemic occurred due to the emergence of SARS-CoV-2, there has always been a demand for a simple and sensitive diagnostic kit for detection of SARS-Cov-2 infection. In January 2020, WHO approved the Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for detecting the presence of Covid-19 genetic material in individuals. Till date many diagnostic kits have arrived in the market for quantification of SARS-CoV-2 antibodies. In spite of being the gold standard method of Covid-19 detection, there are some drawbacks associated with RT-PCR which leads to false-negative results. Hence, in order to fulfil the need for an antibody testing kit for evaluating seroconversion and immunity acquisition in the population, an efficient, highly specific and sensitive assay, Chimera Soochak, an enzyme-linked immunoassay (ELISA) Kit has been developed. It works on the principle of detecting IgG antibodies developed specifically against the S1-RBD by employing a recombinant strain of S1-RBD produced in the HEK293 cell line. The developed kit was validated using different modes and methods to attain the utmost confidence on the samples collected from patients. The validation methodology included, validation with known samples, blind study, third-party validation, validation using WHO Reference Panel and comparison with FDA approved Surrogate virus neutralization kit. The kit was found successful in detecting IgG against the S1-RBD of SARS-CoV-2. The kit had been validated on multiple parameters. A total of 900 samples had been tested by using this kit and it has exhibited the sensitivity, specificity and accuracy for all the above-mentioned parameters.

Prozone phenomenon in pretransplant testing: An interesting conundrum involving solid-phase and cell-based assays.

BACKGROUND: Human leukocyte antigen (HLA) is a major determinant in deciding upon solid organ histocompatibility. Donor-specific anti-HLA antibodies (Donor-specific anti-HLA antibodies (DSAs)) are always a contraindication for solid organ transplantation, and identification of DSA becomes very crucial before transplantation to provide long-term graft survival. For identification of DSA, usually, either cell-based or HLA bead-based assay is being used in laboratories. However, both cell-based and bead-based assays have certain limitations. One such common limitation is "prozone effect," which can give false-negative results. Here, we would like to present a small pilot study to analyze the effect of the prozone phenomenon in the cell-based and HLA bead-based assays and its utility in histocompatibility testing. MATERIALS AND METHODS: In a series of four experiments, cell-based assay, flow cytometric cross-match (FCXM), and HLA bead-based flow cytometric panel reactive antibodies (PRAs) were performed. Single-antigen bead (SAB) testing was conducted as a first experiment on four known positives samples for anti-HLA antibody-antibodies. In the second experiment, these four samples were pooled together (called pooled sera in the text) and tested for FCXM and PRA. In the third experiment, known commercially available positive control sera were mixed with pooled positive sera (positive control sera + pooled sera) to prepare, what we have called "positive concoction" in the text. In the fourth experiment, the positive concoction was diluted serially (1:2, 1:4, 1:8, and 1:16) and FCXM and PRA were performed again to analyze and compare the prozone effect. RESULTS: Pooled sera did not have the expected median fluorescence intensity (MFI) values in FCXM assay, whereas the PRA was showing >90% positivity. In positive concoction, the MFI of FCXM assay was observed to be declining; however, PRA values remained almost constant. Dilutions of the pooled sera showed that MFI values of FCXM assays were increased suddenly after dilution. The highest MFI values were observed in 1:4 dilution of the sera, and then, it declined gradually, but the PRA values remained almost constant even after serial dilutions. CONCLUSION: In our experimental findings, it was clear that cell-based assay (FCXM) was more severely affected by the prozone, whereas solid-phase (flow PRA) assay remained resistant to prozone.

mtDNA Analysis: A Valuable Tool to Establish Relationships in Live Related Organ Transplants.

INTRODUCTION: In India, 90% kidneys for transplantation are obtained from living donor while only 10% come from deceased donors. Since the rate of living organ donors is high, it therefore leads to the problem of organ trafficking.To minimize the chances of organ trafficking, the Transplantation of Human Organ Act (THOA) 2014 was enacted in India that makes it mandatory to prove the relationship between patient and donor by DNA testing. The present study was undertaken to evaluate the degree of matching between maternally related patients and donors, performed using mitochondrial DNA (mtDNA). METHODS: After taking an informed consent, a total of 84 subjects were recruited in the study, 42 kidney transplant recipients and 42 their corresponding donors. An attempt was made to establish and confirm the claimed relationship betweenrecipient and donor using mtDNA analysis. RESULTS: Out of the total 42 cases, mtDNA analysis supported the claimed relationship in 33 (78.57%) cases, whereas in 9 (21.42%) cases claimed relationship could not be supported. CONCLUSION: mtDNA can be used as valuable tool to support the claimed relationships of maternal lineage. It is important that more and more organ transplant physicians, surgeons and committees are made aware of this diagnostic modality.

A guide to organize voluntary stem cell donors recruitment drive for hematopoietic progenitor stem cell transplant.

BACKGROUND: Hematopoietic progenitor cell transplantation (HPCT) is used as a definitive treatment in hematological malignancies. For a successful HPCT, the donor and recipient should have matching human leukocyte antigens (HLAs). About 25% of patients have a chance of finding matching HLA within family, while rests 75% are dependent on voluntary stem cell donor. Globally, there are 75 stem cell registries with more than 30 million donors registered among which India represents 0.36 million. Therefore, finding a stem cell donor for Indian patient is quite difficult. The aim of the present study is to discuss the significance of voluntary stem cell donor recruitment drive and also to guide the drive organizers and their team for effectively organizing the drive to increase the database of such donors. MATERIALS AND METHODS: Voluntary stem cell donor recruitment drives are conducted to spread awareness among the people and motivate them to register as a donor. Once the donors have given their consent, the sample is taken and sent to laboratory for HLA typing and the result is uploaded in World Marrow Donor Association, an international association of member to find the best possible matches for patients with hematological disorders. RESULTS: Genebandhu has organized over 127 recruitment camps since 2012 and recruited 13,000 voluntary stem cell donors. HLA typing of 7446 donors has been completed. Out of this small number of typed donors, 11 lifesaving HPCTs have been successfully facilitated. CONCLUSIONS: Here, we have demonstrated guidelines along with steps to organize voluntary stem cell donors recruitment drive that is needed to increase number of donors, thus increasing significantly the chances of saving many vital lives.

Matched unrelated donor hematopoietic progenitor cell transplantation: A report based on a single registry in India.

INTRODUCTION: Currently, more than 10,000 matched unrelated donor transplants (MUDT) are performed annually worldwide. India has recorded a significant increase in the number of hematopoietic progenitor cell transplantation (HPCT) centers reporting transplants. The number of HPCTs increases by approximately 10% every year, with 1878 transplants reported by Indian stem cell transplant registries in 2016. However, published outcome data of MUDT in India are scant, with reports limited to autologous and allogenic matched unrelated transplants, which motivated us to present our MUDT data. AIMS AND OBJECTIVE: To review the operations, and more importantly, the patient outcome data of a new registry in India. MATERIALS AND METHODS: We accessed an Indian HLA donor database with high-resolution HLA typing results of 7682 (until 31st July 2018) volunteer HLA donors. The typing results were uploaded to proprietary software. The search result was considered a "match" when a 10/10 potential HLA match was found. Patients who were found to be alive through mail communication and did not exhibit signs and symptoms of disease were considered to have disease-free survival (DFS). RESULTS: During the six years of operations of the database, 1165 searches resulted in 68 10/10 matches from the registry. Of these, 11 were MUD HPCT records. At a minimum follow-up of almost 11 months, seven recipients continue to exhibit DFS. CONCLUSIONS: The patient DFS data prove that even a small registry with slightly more than 7000 donors can yield reasonably good patient outcomes.

Strain induced disordered phonon modes in Cr doped PrFeO3.

Room temperature optical absorption spectroscopy (OAS) and Raman spectroscopy measurements have been carried out in order to understand the effect of structural disorder on the electronic and phononic states. For this purpose, polycrystalline samples of Cr doped PrFeO3 have been prepared via wet chemical route. OAS analysis suggests the systematic scaling of electronic disorder with Cr doping; whereas, shifting in Raman line shapes and an increase in Raman line width has been observed with Cr doping. X-ray diffraction analysis clearly suggests the increase in structural disorders in the form of crystallographic strain with Cr doping, which is consistent with the broadening in Raman line shapes. The major contribution to Raman line width has been understood in terms of temperature independent terms i.e. structural disorder induced by doping. The generation of a new phonon mode at ~510 cm-1 has been observed and understood as a disorder phonon mode due to strain induced structural disorder. Moreover, a systematic correlation between crystallographic strain, Raman line width, disordered parameter (σ) and Urbach energy has been observed, which implies that structural disorder affects phononic as well as electronic states of the system. Such comparative study allows us to find the correlation between densities of tail states, structural disorders and anharmonic effects probed by Raman spectroscopy.

Use of flow cytometry in forensic medicine: Current scenario and future prospects.

Several methodologies are being used on different biological, physical and chemical indicators to determine the postmortem interval (PMI); however, most of them are not completely accurate. Flow cytometry is an emerging technology widely used for single cell analysis in the field of clinical pathology. Studies on flow cytometry and its application in the field of forensic medicine were retrieved from systematic web searched of different databases including "MEDLINE", "ScienceDirect", "PubMed" and "Google Scholar" using keywords forensic science; forensic medicine; forensic investigation; flow cytometry; DNA; postmortem interval; vitreous humour with the last search performed in January 2018. A total of 43 publications have been reviewed, and out of them 22 studies met our criteria and have been cited in this article. A handful of studies have evaluated the application of flow cytometry in forensic medicine for estimation of the PMI and identification of the perpetrator of sexual assault cases. Flow cytometry is also useful for quantifying the ABH antigens in red blood cells as well as in other human samples that can be further used for personal identification. In conclusion, flow cytometry is more sensitive, faster and easy compared to the other methods of investigation, thus making it a preferred method. However, a large numbers of studies with the application of flow cytometry on different cases of death are required to establish a universally accepted rate of DNA degradation to avoid errors in judgment.

Amplification or cancellation of Fano resonance and quantum confinement induced asymmetries in Raman line-shapes.

Fano resonance is reported here to be playing a dual role by amplifying or compensating for the quantum confinement effect induced asymmetry in Raman line-shape in silicon (Si) nanowires (NWs) obtained from heavily doped n- and p-type Si wafers respectively. The compensatory nature results in a near symmetric Raman line-shape from heavily doped p-type Si nanowires (NWs) as both the components almost cancel each other. On the other hand, the expected asymmetry, rather with enhancement, has been observed from heavily doped n-type SiNWs. Such a system (p- & n-) dependent Raman line-shape study has been carried out by theoretical line-shape analysis followed by experimental validation through suitably designed experiments. A dual role of Fano resonance in n- and p-type nano systems has been observed to modulate Raman spectra differently and reconcile accordingly to enhance and cease the Raman spectral asymmetry respectively. The present analysis will enable one to be more careful while analyzing a symmetric Raman line-shape from semiconductor nanostructures.

Room-Temperature Magneto-dielectric Effect in LaGa0.7Fe0.3O3+γ; Origin and Impact of Excess Oxygen.

We report an observation of room-temperature magneto-dielectric (RTMD) effect in LaGa0.7Fe0.3O3+γ compound. The contribution of intrinsic/resistive sources in the presently observed RTMD effect was analyzed by measuring direct-current (dc) magnetoresistance (MR) in four-probe geometry and frequency-dependent MR via impedance spectroscopy (MRIS). Present MRIS analysis reveals that at frequencies corresponding to grain contribution (≥1 × 106 Hz for present sample), the observed MD phenomenon is MR-free/intrinsic, whereas at lower probing frequencies (<1 × 106 Hz), the observed MD coupling appears to be MR-dominated possibly due to oxygen excess, that is, due to coexistence of Fe3+ and Fe4+. The magnetostriction is anticipated as a mechanism responsible for MR-free/intrinsic MD coupling, whereas the MR-dominated part is attributed to hopping charge transport along with Maxwell-Wagner and space charge polarization. The multivalence of Fe ions in LaGa0.7Fe0.3O3+γ was validated through iodometric titration and Fe K-edge X-ray absorption near-edge structure measurements. The excess of oxygen, that is, coexistence of Fe3+ and Fe4+, was understood in terms of stability of Fe4+ by means of "bond-valence-sum" analysis and density functional theory-based first-principles calculations. The cation vacancies at La/Ga site (or at La and Ga both) were proposed as the possible origin of excess oxygen in presently studied compound. Present investigation suggests that, to justify the intrinsic/resistive origin of MD phenomenon, frequency-dependent MR measurements are more useful than measuring only dc MR or comparing the trends of magnetic-field-dependent change in dielectric constant and tan δ. Presently studied Fe-doped LaGaO3 can be a candidate for RTMD applications.

Synthesis of 1,3,5-trisubstituted pyrazolines as potential antimalarial and antimicrobial agents.

A series of novel 1,3,5-trisubstituted pyrazolines derivatives have been synthesized from chalcones and nicotinic acid hydrazide in two steps. In first step, chalcones were prepared by treatment of 4-hydroxy acetophenone with different substituted benzaldehyde by Claisen-Schimidt Condensation. In second step, various pyrazoline derivatives were prepared by reflux reaction of chalcones with nicotinic acid hydrazide in ethanolic solution. Compounds were confirmed by elemental analyses, IR, 1H NMR and 13C NMR spectral data and were evaluated for antimalarial and antibacterial activity. Compounds 5n (IC50=0.022µM for MRC-2 and IC50=0.192µM for RKL-9) displayed better antiplasmodial activity than the chloroquine (CQ) against chloroquine-sensitive (MRC-2) and chloroquine-resistant (RKL-9) P. falciparum strains. The in vitro cytotoxicity study conducted on the human HepG2 cell line (>30µM) and selectivity index (100-220) indicate that this series presents an interesting selective antiplasmodial profile. Further, in vitro heme crystallization inhibition assay showed compound 5e inhibited formation of ß-hematin more efficiently than CQ. In addition, antibacterial and antifungal evaluations were conducted, compounds 5c, 5i and 5j displayed better antibacterial activity against S. aureus, B. subtilis, E. coli and P. aeruginosa than ciproafloxacin. Antifungal activity of compound 5l against A. niger (MIC-3.25µg/ml) and C. albicans (MIC-6.5µg/ml) was found to be better than the standard drug fluconazole.