Negative magnetization and magnetic ordering of rare earth and transition metal sublattices in NdFe0.5Cr0.5O3.

We investigate the effect of alloying at the 3dtransition metal site of a rare-earth-transition metal oxide, by considering NdFe0.5Cr0.5O3mixed perovskite with two equal and random distribution of 3d ions, Cr and Fe, interacting with an early 4f rare earth ion, Nd. Employing temperature- and field- dependent magnetization measurements, temperature-dependent x-ray diffraction, neutron powder diffraction, and Raman spectroscopy, we characterize its structural and magnetic properties. Our study reveals bipolar magnetic switching (arising from negative magnetization) and magnetocaloric effect which underline the potential of the studied mixed perovskite in device application. The neutron diffraction study shows the absence of spin reorientation transition over the entire temperature range of 1.5-320 K, although both parent compounds exhibit spin orientation transition. We discuss the microscopic origin of this curious behavior. The neutron diffraction results also reveal the ordering of Nd spins at an unusually high temperature of about 40 K, which is corroborated by Raman measurements.

Low temperature Raman spectroscopic study of anharmonic and spin-phonon coupled quasi-two dimensional rare earth based francisites.

Mineral francisites Cu3Bi(SeO3)2O2Cl are unique compounds with interesting quasi two-dimensional structure along with fascinating magnetic properties. The magnetic properties can be fine-tuned when non-magnetic Bi is replaced by a suitable rare earth (RE) metal. It is because of the inclusion of additional magnetic sub-centre RE apart from Cu. Temperature dependent Raman spectroscopy measurements in RE based francisites [Cu3RE(SeO3)2O2Cl, shortly RECufr] were performed in the range of 11 K-295 K. Among the three studied RECufr (LaCufr, NdCufr, and DyCufr) compounds, the properties of phonon vibration vary from moderate (in DyCufr) to weak (in LaCufr) spin phonon coupled and the absence of spin phonon coupling (SPC) (i.e. strictly anharmonic in nature) was observed in NdCufr and the reason for this observation has been provided. More specifically, two Raman-active phonons soften below the antiferromagnetic ordering temperature ofTN≈ 39 K in DyCufr compound, indicating the existence of moderate SPC. This trend of phonon vibration is correlated with magnetic properties, particularly field induced metamagnetic transition (MMT). Strong MMT enabled DyCufr develops SPC, while weak MMT enabled NdCufr is unable to develop SPC.

Highly correlated structural, local structural, Raman spectroscopic and magnetic properties of Mn-substituted Cu2V2O7.

Low-dimensional quantum spin ½ system Cu2V2O7has been investigated in the framework of Mn-substitution at the Cu site, which is really un-investigated. The studied compounds Cu2 -xMnxV2O7(x= 0, 0.05, 0.1 and 0.15) have been synthesized and characterized structurally, spectroscopically, local structurally and magnetically via x-ray diffraction, Raman, x-ray absorption and temperature, field dependent magnetization measurements respectively. Although Cu2V2O7can be found inα, ßandγ-phase, however all of the studied compounds are found in single orthorhombicα-phase which has crucial magneto-electric application potential. Temperature dependent Raman spectra indicated anharmonic phonon-phonon scattering but there is no spin-phonon coupling for VO4vibrational modes. The local structure probed via x-ray absorption near edge structure and extended x-ray absorption fine structure spectroscopy at 15 K, 300 K indicates Cu2+, V5+and mixed valent Mn2+and Mn3+ionic states and justified local structure for the probed ions. Magnetic measurements indicate long-range antiferromagnetic ordering with doping independent Neel temperature (32.5 K). Further observations are strong magnetic hysteresis at 5 K (due to canted spin structure), zero field exchange-bias and their noteworthy enhancement upon Mn-substitution. Interesting correlation between structural parameters and magnetic exchanges has been developed.

Prevalence and molecular characterization of extended-spectrum ß-lactamase (ESBL) producing Escherichia coli isolated from dogs suffering from diarrhea in and around Kolkata.

Background: Dogs are the favorite companion animals among humans. The close interaction between dogs and people increases the risk of antibiotic resistance spreading. Surveillance for antimicrobial resistance and the identification of ESBL-producing Escherichia coli as an indicator bacterium is an important tool for managing antimicrobial drug therapy. Aims: The present study targeted to identify and characterize ESBL-producing E. coli among dogs suffering from diarrhea in and around Kolkata. Methods: Isolation and identification of E. coli from dogs suffering from diarrhea (n=70) along with screening for the production of both ESBL and AmpC. The isolates were further characterized through antimicrobial resistance profiling, resistance genes (bla CTX-M, bla TEM, and bla SHV) screening, and phylogenetic group study. Results: Among the 70 isolates, 21 (30%) were confirmed ESBL producers. An antibiogram typing of ESBL-producing E. coli revealed that the majority of them were resistant to norfloxacin (85.7%) followed by tetracycline (61.90%), doxycycline (57.14%), piperacillin/tazobactam (52.38%), cotrimoxazole (47.62%), gentamicin (42.62%), amikacin (23.81%), and chloramphenicol (19.05%). Major resistance genes included bla CTX-M (100%), bla TEM (28.57%), and bla SHV (9.50%). The predominant phylogenetic groups were phylogroup A (76%) followed by phylogroup D (24%). Conclusion: The current investigation reported a high prevalence of both ESBL and AmpC ß-lactamase (AmpC) producing E. coli, co-resistance to a distinct group of antibiotics, and co-existence of different ESBL genes in dogs. Our findings highlight the importance of diagnostic antimicrobial susceptibility testing for proper antimicrobial therapy and to prevent antimicrobial resistance from spreading to humans from dogs in Kolkata and the surrounding area.

Comparative occurrence of ESBL/AmpC beta-lactamase-producing Escherichia coli and Salmonella in contract farm and backyard broilers.

The present study was conducted to detect the occurrence of beta-lactamase and biofilm-producing Escherchia coli and Salmonella in apparently healthy broiler birds reared in household and contract poultry farms. In total, 150 cloacal swabs were collected from apparently healthy broiler birds of various age groups reared in backyard (n = 100) and contract farms (n = 50) in West Bengal (India). The isolation rate of ESBL producers was significantly more (P < 0·05) reared in contract poultry farms than those reared in backyard. Majority of the E. coli isolates possessed blaCTX-M followed by blaSHV and blaTEM . Majority of the Salmonella strains possessed blaTEM followed by blaCTX-M , and no blaSHV was detected. The selected sequences of the PCR products were found cognate with blaCTX-M-1 , blaCTX-M-2 , blaCTX-M-9 , blaCTX-M-14 , blaCTX-M-15 , blaSHV-12 and blaTEM-52 . The study detected 46·8% of E. coli and 42·5% of Salmonella strains as biofilm producers. Beta-lactamase-producing Enterobacteriaceae strains showed resistance against tetracycline, chloramphenicol, doxycycline, co-trimoxazole and ampicillin and sensitivity to imipenem-EDTA, colistin and gentamicin. The study revealed the partial clonal relationship of ESBL sequences possessed by the poultry isolates of the present study and local clinical isolates available in the database. The study made consumer awareness about careful handling of live birds or poultry meat to avoid the zoonotic transmission of antimicrobial-resistant Enterobacteriaceae.

Exploring the art of medical photography - an otolaryngologist's perspective.

BACKGROUND: Modern day otolaryngology has expanded beyond the ear, nose and throat to include head and neck surgery and aesthetic facial procedures. Photographic documentation is important within this expanded horizon. The spectrum of clinical photography includes photomicrographs, endoscopic photographs, peri-operative photography and medical social photography. METHOD: This article aimed to review the standard guidelines essential to obtain, store and disseminate photographs and looked at setting up a small clinic with minimal gadgets to suit clinical photography requirements. Elaboration of basic photography techniques in otolaryngology was reviewed, with examples of photographs taken in a clinic by a clinician. Advances and innovation in clinical photography, in the form of smartphone photography, artificial intelligence, device editing and newer hardware and software in otorhinolaryngology was reviewed. CONCLUSION: Having a professional photographer to aid a clinician is a luxury. Simple knowledge and regular practice of basic photography guidelines by a clinician is imperative.

Absence of clinical benefit of FDG PET-CT in staging T1 part-solid lung adenocarcinoma.

AIM: To assess the rates of nodal and metastatic disease and change in management when staging part-solid T1 lung adenocarcinomas using integrated 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-computed tomography (CT) in a UK population. MATERIALS AND METHODS: This was a retrospective review of PET-CT examinations performed to stage radiologically suspected T1 part-solid lung adenocarcinoma (n=58) from two different centres. Rates of detection of nodal and metastatic disease, change in management, and final patient outcome were recorded. RESULTS: PET-CT changed the stage in one patient from N0 to N1. It did not change final management in any patient. CONCLUSIONS: In this UK population, PET-CT had minimal additional diagnostic benefit in staging patients with T1 part-solid lung adenocarcinoma. Especially given its cost, the inclusion of PET-CT for this indication in guidelines should be reviewed.

Effect of Co and Mg doping at Cu site on structural, magnetic and dielectric properties of α-Cu2V2O7.

We have studied the effect of doping of both magnetic (Co) and nonmagnetic (Mg) ions at the Cu site on phase transition in polycrystalline α-Cu2V2O7through structural, magnetic, and electrical measurements. X-ray diffraction reveals that Mg doping triggers an onset ofα- toß-phase structural transition in Cu2-xMgxV2O7above a critical Mg concentrationxc= 0.15, and both the phases coexist up tox= 0.25. Cu2V2O7possesses a non-centrosymmetric crystal structure and antiferromagnetic ordering along with a non-collinear spin structure in theαphase, originated from the microscopic Dzyaloshinskii-Moriya interaction between the neighboring Cu spins. Accordingly, a weak ferromagnetic (FM) behavior has been observed up tox= 0.25. However, beyond this concentration, Cu2-xMgxV2O7exhibits complex magnetic properties. A clear dielectric anomaly is observed in α-Cu2-xMgxV2O7around the magnetic transition temperature, which loses its prominence with the increase in Mg doping. The analysis of experimental data shows that the magnetoelectric coupling is nonlinear, which is in agreement with the Landau theory of continuous phase transitions. Co doping, on the other hand, initiates a sharpαtoßphase transition around the same critical concentrationxc= 0.15 in Cu2-xCoxV2O7but the FM behavior is very weak and can be detected only up tox= 0.10. We have drawn the magnetic phase diagram which indicates that the rate of suppression in transition temperature is the same for both types of doping, magnetic (Co) and nonmagnetic (Zn/Mg).

Metal contaminations in sediment and associated ecological risk assessment of river Mahanadi, India.

Mahanadi is one of the major rivers of peninsular India. Like other Indian rivers, it is contaminated with sewages, industrial discharges, and agricultural runoff. Thus, necessity was felt to monitor its pollution status. Present work was part of that program and aimed to assess the sediment contamination due to the trace metals Cd, Cr, Cu, Mn, Pb, and Zn during 2012-2015. Sediment pollution status and ecological risks were evaluated calculating contamination factor (CF), geo-accumulation (Igeo), pollution load index (PLI), potential ecological risk (EiR), etc. The recorded metal concentrations were Cd BDL of flame mode of AAS; Cr BDL - 73.9; Cu BDL - 44.4; Mn 37.2 - 1887.0; Pb BDL - 29.5; and Zn BDL - 92.5 mg kg-1. As per US EPA guidelines, Cr concentrations at many locations were in the moderately polluted range. Igeo, CF, mCd, PLI, and EiR indicated low pollution levels and low ecological risks due to the trace metals assessed. The sediment quality guidelines (SQGs) indicated that Cr and Cu concentrations exceeded (16% sample) the threshold effect concentrations and may occasionally exhibit adverse biological effects. The association of sediment organic matter, conductivity and content of Cu, and their grouping in component 1 of PCA revealed that the anthropogenic input was dominant and so also the component 2 where Cr exhibited moderately good correlation with organic matter. Cluster analysis of the sampling sites based on pollution status yielded 3 groups: relatively uncontaminated (S3, S4), low to moderately contaminated (S2), and moderately contaminated (S1, S5, S6) stretches.

Multi-drug resistant, biofilm-producing high-risk clonal lineage of Klebsiella in companion and household animals.

Antimicrobial resistance is a global emergency which needs one health approach to address. The present study was conducted to detect the prevalence of beta-lactamase and biofilm-producing Klebsiella strains in rectal swabs (n = 624) collected from healthy dogs, cats, sheep and goats reared as companion or household animals in India. The dogs and cats were frequently exposed to third- or fourth-generation cephalosporins for therapy. The sheep and goats were occasionally exposed to antibiotics and had environmental exposure. Phenotypical ESBL (n = 93) and ACBL (n = 88)-producing Klebsiella were isolated significantly more (P < 0·05) from companion animals than household animals. Majority of the Klebsiella possessed blaCTX-M-15 . The sequences blaCTX-M-15.2 , blaCTX-M-197 and blaCTX-M-225 are reported first time from the companion animals. All ACBL-producing isolates possessed blaAmpC . The present study detected 65·8% of Klebsiella strains as biofilm producers possessing the studied biofilm associated genes. The isolates showed phenotypical resistance against chloramphenicol, tetracycline, doxycycline, co-trimoxazole, ampicillin, cefotaxime/clavulanic acid. The present study showed that companion and household animals (dogs, cats, sheep, goats) may act as a carrier of ESBL/biofilm-producing, multi-drug resistant, high-risk clonal lineage of Klebsiella.

Survey and analysis of knowledge, attitude and practice among otolaryngologists in a state in eastern India in relation to the coronavirus disease 2019 pandemic.

BACKGROUND: The coronavirus disease 2019 pandemic has resulted in various changes in knowledge, attitude and practice among doctors. A survey was conducted of otolaryngologists in India regarding these aspects in relation to the coronavirus disease 2019 pandemic. METHOD: Otolaryngologists from West Bengal (India) were invited to participate in an online self-administered survey. Data were collected and analysed using appropriate methods. RESULTS: Responses from 133 participants, grouped into 4 groups by their career stage, were collected and analysed. Of the participants, 36.8 per cent were directly involved in treating a known or suspected coronavirus disease 2019 patient, although 66.2 per cent considered the personal protective equipment inadequate. Ninety-four per cent indicated that their willingness to perform procedures depended on personal protective equipment availability. Of the respondents, 83.5 per cent revealed additional mental stress due to the pandemic. Of the participants, 41.4 per cent took hydroxychloroquine as coronavirus disease 2019 prophylaxis. CONCLUSION: This study provides an insight into which issues may need attention, to help ENT surgeons tackle the coronavirus disease 2019 pandemic more effectively based on analysis of responses in the survey.

Are thalassemia patients oxidatively challenged?

BACKGROUND: Repeated blood transfusions is the mainstay of treatment for beta thalassemia major patients. Multiple blood transfusions lead to significant iron overload in these patients. Iron overload causes liberation of oxygen free radicals and peroxidative lipid injury. This study has been designed to study whether thalassemics suffer from oxidative injury. It also aims to study the quantum of oxidative injury. METHODS: It is a cross sectional study using cases and controls. Thirty thalassemic patients receiving multiple blood transfusions were included in this study and thirty healthy age and sex matched controls were recruited for the study. Serum ferritin levels, malondialdehyde, nitric oxide levels were estimated. RESULTS: Levels of all the three parameters were significantly increased (p < 0.05) in the cases compared to controls. Mean levels of all three parameters were correlated with serum ferritin levels and number of blood transfusions in increasing order. All the parameters showed fair degree of correlation (r ≥ 0.25, p ≤ 0.05). CONCLUSION: Thalassemic patients receiving multiple blood transfusion suffer from iron overload which results in increased oxidative stress.

Variability of the EG95 antigen-coding gene of Echinococcus granulosus in animal and human origin: implications for vaccine development.

In the present study, the genetic variability of the EG95 protein-coding gene in several animal and human isolates of Echinococcus granulosus was investigated. A total of 24 isolates collected from cattle, buffalo, sheep, goat, dog and man were amplified by Eg95-coding gene-specific primers. From the generated sequence information, a conceptual amino acid sequence was deduced. Phylogenetically, the Eg95 coding gene belongs to the Eg95-1/Eg95-2/Eg95-3/Eg95-4 cluster. Further confirmation on the maximum composite likelihood analysis revealed that the overall transition/transversion bias was 2.913. This finding indicated thatthere is bias towards transitional and transversional substitution. Using artificial neural networks, a B-cell epitope was predicted on primary sequence information. Stretches of amino acid residues varied between animal and human isolates when hydrophobicity was considered. Flexibility also varied between larval and adult stages of the organism. This observation is important to develop vaccines. However, cytotoxic T-lymphocyte epitopes on primary sequence data remained constant in all isolates. In this study, agretope identification started with hydrophobic amino acids. Amino acids with the same physico-chemical properties were present in the middle. The conformational propensity of the Eg95-coding gene of 156 amino acid residues had α-turns and ß-turns, and α-amphipathic regions up to 129, 138-156 and 151-155 residues, respectively. The results indicated potential T-cell antigenic sites. The overall Tajima's D value was negative (-2.404165), indicative of negative selection pressure.

Characterization of beta-lactamase and biofilm producing Enterobacteriaceae isolated from organized and backyard farm ducks.

This study was undertaken to detect the occurrence of beta-lactamase and biofilm producing Enterobacteriaceae in healthy ducks. A total 202 cloacal swabs were collected from ducks kept in organized (n = 92) and backyard (n = 110) farms in West Bengal (India). The ducks had no history of antibiotic intake. Among the 87 phenotypically beta-lactamase producing Escherichia coli, 19 (17·43%), 6 (5·05%) and 15 (13·76%) isolates possessed blaTEM , blaSHV and blaCTX-M respectively. Whereas, 5 (38·46%) Salmonella isolates were found to harbour blaCTX-M . In K. pneumoniae 10 (33·33%), 3 (13·33%), 4 (13·33%) isolates possessed blaTEM , blaSHV and blaCTX-M respectively. The sequences of selected PCR products were found 98% cognate with blaCTX-M-9, blaSHV-12 and blaTEM-1 . Beta-lactamase producing E. coli isolates belonged to 14 different serogroups such as O1, O2, O3, O5, O7, O8, O35, O83, O84, O88, O119, O128, O145 and O157. Moreover, 87 E. coli (79·82%), six Samonella (46·15%) and 13 K. pneumoniae (43·33%) isolates were detected as AmpC producers possessing blaAmpC . Majority of E. coli (46·79%), Salmonella (46·15%) and K. pneumoniae (70%) isolates were detected as biofilm producers and possessed the associated genes (csgA, sdiA, rcsA, rpoS). Significantly higher occurrence of beta-lactamase and biofilm producing Enterobacteriaceae isolates was detected in backyard ducks than organized farms. SIGNIFICANCE AND IMPACT OF THE STUDY: Consumption of antibiotic through feed or during therapy is considered as potential reason for generation of antimicrobial resistant bacteria in birds. This study provides valuable evidence that exposure to contaminated environment may be an additional source for generation of antimicrobial resistant bacteria in backyard ducks. The backyard ducks are reared by marginal farmers in India who cannot offer antibiotics to them either through feed or during therapy due to high cost. The study also reveals a significant correlation between biofilm formation and possession of antimicrobial resistance genes in the bacterial isolates from the ducks.

Effect of CoFe dusting layer and annealing on the magnetic properties of sputtered Ta/W/CoFeB/CoFe/MgO layer structures.

We explored the effect of a CoFe wedge inserted as a dusting layer (0.2 nm-0.4 nm thick) at the CoFeB/MgO interface of a sputtered Ta(2 nm)/W(3 nm)/CoFeB(0.9 nm)/MgO(3 nm)/Ta(2 nm) film-a typical structure for spin-orbit torque devices. Films were annealed at temperatures varying between 300 °C and 400 °C in an argon environment. Ferromagnetic resonance studies and vibrating sample magnetometry measurements were carried out to estimate the effective anisotropy field, the Gilbert damping, the saturation magnetization and the dead layer thickness as a function of the CoFe thickness and across several annealing temperatures. While the as-deposited films present only easy-plane anisotropy, a transition along the wedge from in-plane to out-of-plane was observed across several annealing temperatures, with evidence of a spin-reorientation transition separating the two regions.

Metamagnetic transition and observation of spin-fluctuations in the antiferromagnetic Heusler compound Pd2MnIn.

We report detailed investigations on the structural, magnetic, magneto-transport and calorimetric aspects of a partially ordered Heusler compound Pd2MnIn. The sample shows antiferomagnetic (AFM) state below around 120 K, though positive paramagnetic Curie temperature signifies a complex magnetic ground state with the presence of both ferromagnetic (FM) and AFM correlations. A clear spin-flop type metamagnetic transition is observed as evident from the magnetization and resistivity data. However, non-saturation of magnetization even at 145 kOe of applied field implies that the high field state may be a spin canted state, originating from the enhanced FM correlations by field induced conduction electron spin polarization. The sample shows a profound quadratic temperature dependence of resistivity below about 20-25 K indicating a spin-fluctuation dominated low temperature region. Previous electronic structure calculations show the existence of a subtle balance between superexchange mediated AFM state and an RKKY (Ruderman-Kittel-Kasuya-Yoshida) interaction mediated FM state in Pd2MnIn. Such competing AFM-FM correlations can be accounted for the observed spin fluctuations.

T-Cell Responses in Adults During Natural Respiratory Syncytial Virus Infection.

Background: The pathogenesis of respiratory syncytial virus (RSV) in older adults may be due to age-related T-cell immunosenescence. Thus, we evaluated CD4 and CD8 T-cell responses during RSV infection in adults across the age spectrum. Methods: Peripheral blood mononuclear cells collected during RSV infection in adults, age 26-96 years, were stimulated with live RSV and peptide pools representing F, M, NP, and G proteins and analyzed by flow cytometry. Results: There were no significant age-related differences in frequency of CD4+ T cells synthesizing interferon (IFN)γ, interleukin (IL)2, IL4, IL10, or tumor necrosis factor (TNF)α or in CD8+IFNγ+ T cells. IL4+CD4+ T-cell numbers were low, as were IL13 and IL17 responses. However, in univariate analysis, CD4 T-cell IFNγ, IL2, IL4, IL10, and TNFα responses and CD8+IFNγ+ T cells were significantly increased with more severe illness requiring hospitalization. In multivariate analysis, viral load was also associated with increased T-cell responses. Conclusions: We found no evidence of diminished RSV-specific CD4 or CD8 T-cell responses in adults infected with RSV. However, adults with severe disease seemed to have more robust CD4 and CD8 T-cell responses during infection, suggesting that disease severity may have a greater association with T-cell responses than age.

One- and Two-Photon Uncaging: Carbazole Fused o-Hydroxycinnamate Platform for Dual Release of Alcohols (Same or Different) with Real-Time Monitoring.

A one- and two-photon activated photoremovable protecting group (PRPG) was designed based on a carbazole fused o-hydroxycinnamate platform for the dual (same or different) release of alcohols. The mechanism for the dual release proceeds through a stepwise pathway and also monitors the first and second photorelease in real time by an increase in fluorescence intensity and color change, respectively. Further, its application in staining live neurons and ex vivo imaging with two-photon excitation is shown.

Unique transcriptome signatures and GM-CSF expression in lymphocytes from patients with spondyloarthritis.

Spondyloarthritis encompasses a group of common inflammatory diseases thought to be driven by IL-17A-secreting type-17 lymphocytes. Here we show increased numbers of GM-CSF-producing CD4 and CD8 lymphocytes in the blood and joints of patients with spondyloarthritis, and increased numbers of IL-17A+GM-CSF+ double-producing CD4, CD8, γδ and NK cells. GM-CSF production in CD4 T cells occurs both independently and in combination with classical Th1 and Th17 cytokines. Type 3 innate lymphoid cells producing predominantly GM-CSF are expanded in synovial tissues from patients with spondyloarthritis. GM-CSF+CD4+ cells, isolated using a triple cytokine capture approach, have a specific transcriptional signature. Both GM-CSF+ and IL-17A+GM-CSF+ double-producing CD4 T cells express increased levels of GPR65, a proton-sensing receptor associated with spondyloarthritis in genome-wide association studies and pathogenicity in murine inflammatory disease models. Silencing GPR65 in primary CD4 T cells reduces GM-CSF production. GM-CSF and GPR65 may thus serve as targets for therapeutic intervention of spondyloarthritis.