Lead-Free Piezoelectric Energy Harvester Based on 2D Bismuth Titanate.

The use of two-dimensional (2D) layered materials with a noncentrosymmetric structure dramatically increases the potential of nanoscale electromechanical systems and electronic devices. In this work, liquid-phase exfoliation of bulk bismuth titanate was employed to synthesize atomically thin 2D sheets and fabricate a high-performance piezoelectric energy harvester. The structural and morphological properties of the 2D sheets were analyzed, confirming their phase purity and layer formation. Piezoelectric properties of the 2D sheets were evaluated using Piezoresponse Force Microscopy (PFM), demonstrating a high d33 piezoelectric coefficient of 40 pm/V in a few-layer bismuth titanate nanosheet. A prototype energy harvesting device was fabricated with 2D bismuth titanate as the active material. The piezoelectric response of the fabricated device was recorded at different frequencies and forces, which yielded a maximum d33 of 57.8 pC/N at 1 Hz. Such a solid electromechanical performance at a relatively infinitesimal input response indicates that 2D bismuth titanate can be useful for piezoelectric energy harvesting applications.

Energy harvesting from radio waves using few-layer 2D galena (galenene).

Radiofrequency (RF) energy harvesting is receiving increased attention in today's digital era due to its potential to replace or improve the longevity of energy storage devices in low-power IoT devices. RF energy is available in the ambient environment, but efficient devices are still not commonly known for RF energy harvesting applications. Here, the main goal is to develop an RF energy harvesting device using multi-layered two-dimensional (2D) galena (PbS). A Schottky diode is fabricated by using 2D galena. RF energy harvesting is demonstrated using a handheld radio transceiver with a carrier frequency of 140-170 MHz. The device extracts RF energy and produces an output DC voltage of a maximum of 1.8 volts and a corresponding output power of 38 mW at 150 MHz, and lights up an LED within a range of 100 cm. At 150 MHz, the device's power conversion efficiency is found to be 19%. DFT calculations support the experimental observations of energy harvesting using 2D galena. The performance results show that 2D galena is a promising material for RF energy harvesting devices.

Clinical Spectrum of Monogenic Infantile-Onset Inflammatory Bowel Disease.

Very-early-onset IBD and infantile-onset IBD is extremely rare in children. There is paucity of data with regards to clinical profile and outcome of children with infantile-onset IBD from India. The clinicolaboratory profile, molecular genetic testing and treatment details of 8 children diagnosed with monogenic infantile-onset IBD during 2015-2020 is described here. The median age at onset of symptoms was 3 mo. Sibling death and consanguinity were noted in 4 (50%) each respectively. Diarrhea was the presentation in all (100%) and hematochezia in 5 (62%). Colonic ulcers on colonosopy was seen in 7 infants. The common mutation identified was IL-10R gene in 3 (42%) and LRBA gene mutation in 2 (25%). HSCT was done in 4 children and the rest were managed conservatively. Although there was no mortality in this series, two children (25%) were lost for follow-up.

Identification of potential anti-leishmanial agents using computational investigation and biological evaluation against trypanothione reductase.

Trypanothione reductase of Leishmania donovani is a flavin adenine dinucleotide containing homodimeric protein essential for parasite survival. The flavoenzyme utilizes nicotinamide adenine dinucleotide phosphate in the reaction to convert oxidized trypanothione to reduced trypanothione which is further used up by tryparedoxin/tryparedoxin peroxidase system to neutralize the reactive oxygen species generated by the macrophages. Some of the drugs previously reported against the disease include sodium stibogluconate, miltefosine and amphotericin B. However, due to the resistance and toxicity problem associated with these molecules, there is an urgent need to develop new drugs against L. donovani. Trypanothione reductase of L. donovani is one such essential target whose inhibition could lead to a decline in parasite growth. In this work, we have performed a computational studies using Maybridge library of chemical compounds to identify potential inhibitors of Trypanothione reductase of L. donovani. Structure-based virtual screening method in combination with molecular docking was employed to identify and prioritize 30 compounds which were further subjected to molecular dynamics simulation. Ten compounds which showed stable ligand root-mean-square deviation plot, c-alpha backbone and root-mean-square fluctuation were considered for trypanothione reductase inhibition assay and subsequent inhibition studies of parasite growth. Enzyme inhibition assay resulted in shortlisting of four compounds that were found to inhibit Trypanothione reductase of L. donovani. Subsequently, the anti-leishmanial screening highlighted one compound as the potential anti-leishmanial agent, with IC50 value of 15.2 µM, that can be further optimised with medicinal chemistry efforts to improve its activity. Communicated by Ramaswamy H. Sarma.

Uncommon Anatomic Variation of Left Internal Mammary Artery: God-Created Y-Graft Conduit.

The left internal mammary artery is the most accepted and widely used conduit in coronary artery bypass grafting. This report presents a rare case of very early bifurcation of the left internal mammary artery at the level of the third intercostal space.

Infected Teflon felt strip-paracardiac abscess after Dor's procedure.

Foreign material used for reconstructing or suturing the cardiac chambers carries the risk of infection. When such a scenario is encountered, it is better to be aggressive in removing the infected source surgically, as conservative management will most often result in recurrence. Herein, we present an unusual case of infected prosthetic material after cardiac surgery that was managed surgically. This case reminds us of the surgical principle of eradicating the source of infection, which should be given priority.

Neonatal septicaemia caused by vancomycin resistant enterococcus faecium-a case report.

Neonatal bacterial sepsis is one of the major causes of morbidity and mortality in neonates. 10% cases of neonatal bacteraemia and septicaemia are caused by Enterococci. The increasing incidence of Vancomycin resistant enterococci (VRE) is of particular concern because of limited treatment options and increased mortality. We report here a case of neonatal sepsis in a premature baby caused by vancomycin resistant Enterococcus faecium Van A phenotype from a tertiary care Hospital in South India. A preterm baby boy with low birth weight was admitted to the NICU with Respiratory distress and meconium aspiration. On 5(th) day the baby succumbed to death and a final diagnosis of respiratory distress and meconium aspiration with sepsis was made. Blood cultures sent yielded vancomycin resistant Enterococcus faecium (minimum inhibitory concentration ≥ 256 µg/ml). It was confirmed as Enterococcus feacium Van A phenotype by Automated Vitek system.

Left atrial myxoma presenting as acute inferior wall infarction-a case report.

Acute myocardial infarction is a rare form of presentation in patients with left atrial myxoma. With wider availability of echocardiography, more and more patients with atrial myxomas will be diagnosed. This report describes a patient with left atrial myxoma who presented features of acute myocardial infarction and had surgical removal of LA myxoma.