Tuning the photocatalytic/electrocatalytic properties of MoS2/MoSe2 heterostructures by varying the weight ratios for enhanced wastewater treatment and hydrogen production

Two-dimensional (2D) heterojunctions with layered structures give high flexibility in varying their photocatalytic/electrocatalytic properties. Herein, 2D/2D heterostructures of MoS₂/MoSe₂ with different weight-ratios (1 : 1, 1 : 3, and 3 : 1) have been prepared by a simple one-step microwave-assisted technique. The characterization studies confirm formation of crystalline MoS₂/MoSe₂ nanoparticles with a high surface area (60 m² g⁻¹) and porous structure. The high synergistic-effect (1.73) and narrow bandgap (∼1.89 eV) of the composites result in enhanced photo-degradation efficiency towards methylene blue dye (94%) and fipronil pesticide (80%) with high rate constants (0.33 min⁻¹ and 0.016 min⁻¹ respectively) under visible light. The effect of pH, catalyst dose, and illumination area on photodegradation has been optimized. Photodegradation of real-industrial wastewater shows 65% COD and 51.5% TOC removal. Trapping experiments confirm that holes are mainly responsible for degradation. The composites were highly reusable showing 75% degradation after 5-cycles. MoS₂/MoSe₂ composites show excellent electrochemical water-splitting efficacy through hydrogen-evolution-reaction (HER) exhibiting a stable high current density of −19.4 mA cm⁻² after 2500 cyclic-voltammetry (CV) cycles. The CV-plots reveal high capacitance activity (C_dl value ∼607 μF cm⁻²) with a great % capacitance retention (>90%). The as-prepared 2D/2D-catalysts are highly active in sunlight and beneficial for long-time physico-chemical wastewater treatment. Moreover, the electrochemical studies confirm that these composites are potential materials for HER activity and energy-storage applications.

The 2D/2D-MoS₂/MoSe₂ catalysts with good photocatalytic/electrocatalytic properties can be potential materials for wastewater treatment and hydrogen production.     

An epidemiological analysis of patients with abdominal trauma in an eastern Indian metropolitan city

The profile and pattern of abdominal trauma is changing with progressing civilisation. We are lacking epidemiological data from most parts of the world. This study was conducted to prepare a database in our set up and look into the pattern of abdominal trauma, make an aetiological correlation of abdominal trauma with the types of injuries, identify the preventable factors causing delay in intervention and, compare the data with the other available national and international data. This prospective, observational study was done in a teaching hospital in a metropolitan city of eastern India. Records of patients with abdominal trauma were collected in predesigned forms, from admission to discharge. Data were analysed applying standard statistical techniques. Males (87.3%) predominated with the age range between 21 and 30 years, and the majority (73.5%) had blunt abdominal trauma. Compression injury (57.3%) commonly caused blunt trauma and stab injuries caused majority of penetrating trauma. The commonest organ injured both in blunt and penetrating trauma was small bowel (30.7% and 33.3% respectively). It was found that prehospital trauma care is virtually non-existent in this region. We are lacking a uniform protocol for the management of abdominal trauma across the hospitals. With the availability of better investigational modalities we are moving more towards a conservative approach to the abdominal trauma patients, especially the blunt abdominal trauma patients with solid organ injuries.     

Performance Enhancement in N2 Plasma Modified AlGaN/AlN/GaN MOS-HEMT Using HfAlOX Gate Dielectric with Γ-Shaped Gate Engineering

In this paper, we have demonstrated the optimized device performance in the Γ-shaped gate AlGaN/AlN/GaN metal oxide semiconductor high electron mobility transistor (MOS-HEMT) by incorporating aluminum into atomic layer deposited (ALD) HfO₂ and comparing it with the commonly used HfO₂ gate dielectric with the N₂ surface plasma treatment. The inclusion of Al in the HfO₂ increased the crystalline temperature (~1000 °C) of hafnium aluminate (HfAlO_X) and kept the material in the amorphous stage even at very high annealing temperature (>800 °C), which subsequently improved the device performance. The gate leakage current (I_G) was significantly reduced with the increasing post deposition annealing (PDA) temperature from 300 to 600 °C in HfAlO_X-based MOS-HEMT, compared to the HfO₂-based device. In comparison with HfO₂ gate dielectric, the interface state density (D_it) can be reduced significantly using HfAlO_X due to the effective passivation of the dangling bond. The greater band offset of the HfAlO_X than HfO₂ reduces the tunneling current through the gate dielectric at room temperature (RT), which resulted in the lower I_G in Γ-gate HfAlO_X MOS-HEMT. Moreover, I_G was reduced more than one order of magnitude in HfAlO_X MOS-HEMT by the N₂ surface plasma treatment, due to reduction of N₂ vacancies which were created by ICP dry etching. The N₂ plasma treated Γ-shaped gate HfAlO_X-based MOS-HEMT exhibited a decent performance with I_DMAX of 870 mA/mm, G_MMAX of 118 mS/mm, threshold voltage (V_TH) of −3.55 V, higher I_ON/I_OFF ratio of approximately 1.8 × 10⁹, subthreshold slope (SS) of 90 mV/dec, and a high V_BR of 195 V with reduced gate leakage current of 1.3 × 10⁻¹⁰ A/mm.     

Correlation of the severity of atopic dermatitis with absolute eosinophil counts in peripheral blood and serum IgE levels

BACKGROUND: Although a number of epidemiological studies, showing incidence and prevalence of atopic dermatitis, were available, scant attention has been paid to the correlation between the parameters of the disease like severity, absolute eosinophil count and IgE level, which has been known to be associated inconsistently. Hence this study was undertaken. METHODS: A total of 102 patients of atopic dermatitis, both children and adults, and 107 age matched controls were studied at the Pediatric Dermatology clinic, Institute of Child Health and department of Dermatology, AMRI-Apollo hospitals, Kolkata. RESULTS: The average age of onset of atopic dermatitis was observed to be 4.55 years. Both the average absolute eosinophil count and IgE levels in patients of atopic dermatitis were significantly higher than that of the controls. Each of these parameters showed significant correlation with severity of the disease and showed a nonhomogeneous distribution reflected by significant association with personal history of bronchial asthma and family history of atopy, when both parents were atopic. CONCLUSIONS: Our study shows that clinical activity of the disease as recorded by the "SCORAD" index can be used as an indicator of the hematological abnormalities as well as to some extent as a prognostic indicator. Family history of atopy correlates with the hematological abnormalities only if both parents are involved and bronchial asthma is the only associated atopic condition which correlates with the parameters of the disease .