Origin of ferromagnetism in Cs2_2AgF4_4: importance of Ag - F covalency

The magnetic nature of Cs$_{2}$AgF$_{4}$, an isoelectronic and isostructural analogue of La$_2$CuO$_4$, is analyzed using density functional calculations. The ground state is found to be ferromagnetic and nearly half metallic. We find strong hybridization of Ag-$d$ and F-$p$ states. Substantial moments reside on the F atoms, which is unusual for the halides and reflects the chemistry of the Ag(II) ions in this compound. This provides the mechanism for ferromagnetism, which we find to be itinerant in character, a result of a Stoner instability enhanced by Hund's coupling on the F

Clinical profile of patients with COVID-19 and tuberculosis co-infection in a tertiary care hospital

Background: Historical evidences suggest that Tuberculosis (TB) with concurrent respiratory viral infections, such as, Influenza has been associated with higher mortality. TB and COVID-19 co-infection has implications beyond mortality at the individual level. Hence there is a need to study the clinical characteristics and outcomes in COVID-19 and TB co-infection.Methods: In this retrospective observational study, COVID-19 cases admitted to Victoria Hospital, a tertiary care hospital in Bengaluru, twenty-six patients with COVID 19 and TB co-infection were observed and their clinical characteristics, radiological and laboratory parameters were recorded and analyzed for the impact of COVID-19 on TB.Results: Raised inflammatory markers, high neutrophil to lymphocyte ratio (NLR), lymphocytopenia were observed in majority of the cases. There was worsening of Tubercular lesions on Chest radiography in eighteen patients (69%). Out of the twenty six, sixteen patients (61%) needed supplemental oxygen therapy at admission, Five (19%) of them needed Assisted ventilation and intensive care. Out of the five patients who needed intensive care, two (7.6%) patients succumbed to death owing to Severe COVID-19 pneumonia, respiratory failure and other co-morbid conditions.Conclusions: Co-infection with COVID-19 and TB alters the severity, the course and management of the disease and can be associated with adverse outcomes and is associated with high mortality; a high index of suspicion is required for the detection of this co-infection and bi-directional screening of COVID-19 and TB must be carried out for the early detection and management of this co-infection.

Study of the causes of non-acceptance of VBAC in patients with previous one LSCS in a tertiary institution

Background: Many women who are eligible candidates for a VBAC (Vaginal Birth after Caesarean) in the current pregnancy opt for a repeat LSCS (Lower Segment Caesarean Section) as a mode of delivery. We decided to evaluate the proportion of patients who opt out of a VBAC and to study the causality of this trend.Methods: All patients who presented to the Dept. of OBG in our institution and were eligible to have a VBAC were included in the study till the sample size of 100 cases was met. Consultant opinion was sought prior to deciding the mode of delivery.Results: Incidence of patients of previous one LSCS who were not willing for VBAC was 4%, out of total number of deliveries and 30.7%, out of all cases of patients with previous one LSCS. The reason for not opting for a VBAC in the current pregnancy in the majority of the eligible patients was the desire for a concurrent sterilization procedure. Others cited apprehension of a scar rupture or fear of labor pain or both as their primary reason for opting out of a VBAC.Conclusions: The high incidence of ERC (Elective Repeat Caesarean) as compared to TOLAC (Trial of Labour after Caesarean) has long-term clinical and financial implications. Counseling given to the pregnant woman with an emphasis on the advantages of VBAC in order that she opts for a VBAC with confidence and enthusiasm is the only way forward

Podoplanin expression in oral potentially malignant disorders and oral squamous cell carcinoma

Podoplanin is a type I transmembrane sialomucin-like glycoprotein that is specifically expressed in lymphatic endothelial cells. Studies have shown that assessment of podoplanin expression in the epithelial cells can be used to predict the malignant transformation of potentially malignant disorders and the metastatic tendency of primary head and neck squamous cell carcinoma. The aim of our study was to compare the expression of podoplanin in oral leukoplakia, oral submucous fibrosis and oral squamous cell carcinoma with that in normal buccal mucosa by immunohistochemical methods. Immunohistochemical expression of podoplanin was analyzed in 20 cases each of oral leukoplakia, oral submucous fibrosis, oral squamous cell carcinoma and normal buccal mucosa, with monoclonal antibody D2-40. The expression of podoplanin was graded from grade 0-4. There was a statistically significant upregulation of the grades of podoplanin expression in oral squamous cell carcinoma(100%), oral submucous fibrosis (90%) and oral leukoplakia (65%) when compared to that in normal mucosa(35%). Podoplanin expression increased with decrease in grades of differentiation in oral squamous cell carcinoma . Podoplanin expression in the samples of oral submucous fibrosis was higher than that in oral leukoplakia. Evaluation of podoplanin expression in the epithelial cells of oral dysplastic lesions may provide valuable information to predict their risk of malignant transformation

The protective effect of Withania somnifera against oxidative damage caused by ethanol in the testes of adult male rats

Background: To investigate the effect of Withania somnifera (WS) in preventing the damage caused by alcohol on testis.Methods: Adult male Wistar rats were divided into 4 groups. Group A - control, Group B - WS200 mg orally, Group C - alcohol 4 g/kg orally, and Group D - WS + alcohol. The sperm parameters were examined. Testicular tissues were examined for biochemical (glutathione [GSH] peroxidase, superoxide dismutase, catalase (CAT), malondialdehyde [MDA]) analysis, and histopathological changes.Results: Biochemical parameters revealed tissue oxidative stress in alcohol group which was evidenced as increase in MDA level and reduction in CAT and GSH activities in testes which was reduced in co-treatment group. WS significantly reduced alcohol-induced sperm shape abnormality and sperm count. The alcohol-induced changes in histopathologic findings were partially reversed by treatment with WS.Conclusion: These observations suggest that the antioxidant property of WS might have contributed for its ability to ameliorate the testicular toxicity caused by alcohol

Nanotechnology and the Developing World

How nanotechnology can be harnessed to address some of the world's most critical development problem

Bridging frustrated-spin-chain and spin-ladder physics: quasi-one-dimensional magnetism of BiCu2PO6

We derive and investigate the microscopic model of the quantum magnet BiCu2PO6 using band structure calculations, magnetic susceptibility and high-field magnetization measurements, as well as ED and DMRG techniques. The resulting quasi-one-dimensional spin model is a two-leg AFM ladder with frustrating next-nearest-neighbor couplings along the legs. The individual couplings are estimated from band structure calculations and by fitting the magnetic susceptibility with theoretical predictions, obtained using ED. The nearest-neighbor leg coupling J1, the rung coupling J4, and one of the next-nearest-neighbor couplings J2 amount to 120-150 K, while the second next-nearest-neighbor coupling is J2'~J2/2. The spin ladders do not match the structural chains, and although the next-nearest-neighbor interactions J2 and J2' have very similar superexchange pathways, they differ substantially in magnitude due to a tiny difference in the O-O distances and in the arrangement of non-magnetic PO4 tetrahedra. An extensive ED study of the proposed model provides the low-energy excitation spectrum and shows that the system is in the strong rung coupling regime. The strong frustration by the next-nearest-neighbor couplings leads to a triplon branch with an incommensurate minimum. This is further corroborated by a strong-coupling expansion up to second order in the inter-rung coupling. Based on high-field magnetization measurements, we estimate the spin gap of 32 K and suggest the likely presence of antisymmetric DM anisotropy and inter-ladder coupling J3. We also provide a tentative description of the physics of BiCu2PO6 in magnetic field, in the light of the low-energy excitation spectra and numerical calculations based on ED and DMRG. In particular, we raise the possibility for a rich interplay between one- and two-component Luttinger liquid phases and a magnetization plateau at 1/2 of the saturation value

Provider reported implementation of nutrition-related practices in childcare centers and family childcare homes in rural and urban Nebraska

Approximately 15 million children under age 6 are in childcare settings, offering childcare providers an opportunity to influence children’s dietary intake. Childcare settings vary in organizational structure – childcare centers (CCCs) vs. family childcare homes (FCCHs) – and in geographical location – urban vs. rural. Research on the nutrition-related best practices across these childcare settings is scarce. The objective of this study is to compare nutrition-related best practices of CCCs and FCCHs that participate in the Child and Adult Care Food Program (CACFP) in rural and urban Nebraska. Nebraska providers (urban n = 591; rural n = 579) reported implementation level, implementation difficulty and barriers to implementing evidence-informed food served and mealtime practices. Chi-square tests comparing CCCs and FCCHs in urban Nebraska and CCCs and FCCHs in rural Nebraska showed sub-optimal implementation for some practices across all groups, including limiting fried meats and high sugar/ high fat foods, using healthier foods or non-food treats for celebrations and serving meals family style. Significant differences (p \u3c .05) between CCCs and FCCHs also emerged, especially with regard to perceived barriers to implementing best practices. For example, CCCs reported not having enough money to cover the cost of meals for providers, lack of control over foods served and storage problems, whereas FCCHs reported lack of time to prepare healthier foods and sit with children during mealtimes. Findings suggest that policy and public health interventions may need to be targeted to address the unique challenges of implementing evidence-informed practices within different organizational structures and geographic locations