Investigating Electronic, Optical, and Phononic Properties of Bulk γ-M<inf>2</inf>ON<inf>2</inf>and β-M<inf>7</inf>O<inf>8</inf>N<inf>4</inf>(M = Hf and Zr) Insulators Using Density Functional Theory

Hafnium and zirconium oxynitrides have similar properties, yet a consolidated investigation of their intrinsic properties has not been carried out. In this paper, we perform first-principles density functional theory calculations of γ- and β-phase hafnium and zirconium oxynitrides, which show that the γ-M2ON2(M = Hf and Zr) is an indirect band-gap (Eg) insulator, while the β-M7O8N4has a "pseudo-direct" type of Eg. β-phase has higher Egthan γ-phase, with concomitant disappearance of the conduction band tail. Optical properties in γ-M2ON2show that the anisotropy is negligible, and the optical constant values are in the range of other superhard materials. Phonon calculations present peculiar characteristics such as a small phonon band gap in γ-Hf2ON2and imaginary phonon frequencies in β-phases relating to lattice instability. The phononic properties are unfavorable for their potential use as an absorber material of the hot carrier solar cell-an emerging photovoltaic concept

Free charges versus excitons: photoluminescence investigation of InGaN/GaN multiple quantum well nanorods and their planar counterparts

InGaN/GaN multiple quantum well (MQW) nanorods have demonstrated significantly improved optical and electronic properties compared to their planar counterparts. However, the exact nature of the processes whereby nanorod structures impact the optical properties of quantum wells is not well understood, even though a variety of mechanisms have been proposed. We performed nanoscale spatially resolved, steady-state, and time-resolved photoluminescence (PL) experiments confirming that photoexcited electrons and holes are strongly bound by Coulomb interactions (i.e., excitons) in planar MQWs due to the large exciton binding energy in InGaN quantum wells. In contrast, free electron–hole recombination becomes the dominant mechanism in nanorods, which is ascribed to efficient exciton dissociation. The nanorod sidewall provides an effective pathway for exciton dissociation that significantly improves the optical performance of InGaN/GaN MQWs. We also confirm that surface treatment of nanorod sidewalls has an impact on exciton dissociation. Our results provide new insights into excitonic and charge carrier dynamics of quantum confined materials as well as the influence of surface states

Performance of Tomato with Organic Manures in Plastic Tunnel

Tomato is one of the most demanded vegetable with increasing trend of commercial cultivation in Nepal. As it is the heavy feeder crop thus soil nutrient management has been always challenging. Since, in modern world organic production has been favored by consumers for many reasons thus we aimed to compare the efficacy of various compost, mineral fertilizers and their combinations in tomato production and soil productivity. For the purpose a field experiment in plastic tunnel was carried out in Horticulture Research Division, Khumaltar in two consecutive years (2014 and 2015). Srijana, a popular tomato hybrid among commercial producers, was purposively selected. Eight treatments (control, recommended doses of chemical fertilizers, compost 15 t ha-1 + cattle urine, compost 10 t ha-1 + cattle urine, compost 12.5 t ha-1 + cattle urine, compost 15 t ha-1 + 1/4 recommended dose of chemical fertilizers, compost 10 t ha-1 + ¾ recommended dose of chemical fertilizer and compost 12.5 t ha-1 + 1/2 recommended dose of chemical fertilizer) were laid out in randomized complete block design and replicated thrice. The result showed significant (p &lt; 0.05) positive correlation between the plant height and yield of tomato. The treatment with compost dose of 12.5 t ha-1 with half dose of recommended dose of chemical fertilizers produced the highest incremental yield (85% increment) over other treatments followed by compost 15 t ha-1 with cattle urine. Addition of soil organic carbon, soil nitrogen, soil potassium by the increasing level of compost though not significant, but increment in carbon content, nitrogen content and potassium content of soil observed in successive years. For commercial producer at plastic tunnel, compost at the rate 12.5 t ha-1 with half dose of recommended level of chemical fertilizer (100:90:40 kg N:P:K ha-1) is recommended to apply in field, while for organic producer, application of 15 tha-1 compost with fermented cattle urine is recommended

Study of Serum Lactate Dehydrogenase and Gamma-Glutamyl Transpeptidase in Breast Cancer Patients Receiving Chemotherapy.

Breast cancer (BC) is the most common type of cancer worldwide, being a major cause of morbidity in female. In Nepal it is the second most common type of cancer among females of perimenopausal age group. More than one quarter of the BC diagnosed in young Nepalese female, with familial history of breast cancer, early pregnancy, longer lactation and estrogen exposure and often with tumors showing aggressive biological behaviors. Anthracyclines (Doxorubicin) based treatment regime were reported to cause cardiotoxicity by increasing intramyocardial free radical production, lipid alterations and decreasing antioxidant level. Oxidative stress involving cellular reactive oxygen species (ROS) production is widely accepted mechanism but the molecular basis of chemotherapy induced organ toxicity remains highly controversial. An increased rate of metabolism and oxidative stress results rapid turnover of cancer cells that modulates the enzyme level in blood circulation. Serum LDH and GGT level correlates with tumor burden, metastatic character of BC and intensity of organtoxicity. The aim of our study is to evaluate the serum level of LDH and GGT in BC patients receiving chemotherapy and correlate these enzyme levels with different stages of BC. A total number of 150 subjects were included in the study, comprising 90 histopathologically confirmed 24 to 76 years aged patients of different breast cancer stages, receiving at least 3 cycles of 5-Fluorouracil, Adriamycin and Cyclophosphamide (FAC) chemotherapy. Sixty age- matched healthy women were enrolled as controls. Blood samples from each individual was collected after informed consent and analysed for serum LDH and GGT levels using standard biochemical methods. Data were analyzed using student's paired 't' test, Pearson correlation test and ANOVA. Serum LDH and GGT levels were significantly (p&lt;0.001) increased in BC patients as compared to control group. When all 4 stages of BC were compared to control group, LDH and GGT showed steady and progressive increase in the activities of these enzymes from stage I-IV. The study concludes that serum LDH and GGT may be sensitive, specific and cost effective biomarkers in early diagnosis of breast cancer, assessing cancer prognosis and response to treatment

Prevalence Study of H. pylori infection in Dyspeptic patients coming to Nepal Medical College Teaching Hospital, Jorpati, Kathmandu

ABSTRACT Helicobacter pylori (H. pylori) is one of the most common human infections worldwide particularly in the developing countries. It has been established as etiology of chronic gastritis and peptic ulcer disease, gastric adenocarcinoma and mucosal associated lymphoid tissue lymphoma (MALT). During this decade, there have been some reports showing a decline in global prevalence of H. pylori infection and peptic diseases including many Asian countries. Hence to determine prevalence of Helicobacter pylori infection in dyspeptic patients, this descriptive, non-interventional study was carried out at the Endoscopy sub-unit of the Surgery Department from April 2011 to February 2012. Three hundred nineteen dyspeptic patients (Male 161 and female 152) with a mean age of 20.12 years were examined for the presence of H. pylori infection by histology staining. The prevalence of H. pylori infection was 50.47%. The most common endoscopic fi ndings was gastritis (47.6%) followed by normal fi ndings 57 (17.87%). A total of 8.47% of gastric Ulcer, oesophagitis 5.64% and gastric cancer 0.94% were detected. All three cases of gastric cancer were positive for H. pylori infection. Among gastritis, H. pylori was observed in 67 (44%) cases and 18 out of 57 (5.6 %) of normal gastric mucosa showed H. pylori. The endoscopic fi ndings such as gastritis, gastric ulcer, duodenal ulcer and gastro duodenal refl ux are signifi cantly associated with H pyloric infection. The prevalence of H. pylori infection is still high in peptic diseases. H pylori infection is signifi cantly correlated with peptic ulcer diseases than with non-ulcer dyspepsia. Further studies are required to establish the H. pylori positive cases with that of other tests such as serological detection of anti H. pylori antibody by ELISA/ICT and culture to establish a diagnosis quickly without any invasive method and institute proper management thus reducing morbidity

Effects of climatic factors on diarrheal diseases among children below 5 years of age at national and subnational levels in Nepal: an ecological study

INTRODUCTION: The incidence of diarrhea, a leading cause of morbidity and mortality in low-income countries such as Nepal, is temperature-sensitive, suggesting it could be associated with climate change. With climate change fueled increases in the mean and variability of temperature and precipitation, the incidence of water and food-borne diseases are increasing, particularly in sub-Saharan Africa and South Asia. This national-level ecological study was undertaken to provide evidence linking weather and climate with diarrhea incidence in Nepal. METHOD: We analyzed monthly diarrheal disease count and meteorological data from all districts, spanning 15 eco-development regions of Nepal. Meteorological data and monthly data on diarrheal disease were sourced, respectively, from the Department of Hydrology and Meteorology and Health Management Information System (HMIS) of the Government of Nepal for the period from 2002 to 2014. Time-series log-linear regression models assessed the relationship between maximum temperature, minimum temperature, rainfall, relative humidity, and diarrhea burden. Predictors with p-values < 0.25 were retained in the fitted models. RESULTS: Overall, diarrheal disease incidence in Nepal significantly increased with 1 degrees C increase in mean temperature (4.4%; 95% CI: 3.95, 4.85) and 1 cm increase in rainfall (0.28%; 95% CI: 0.15, 0.41). Seasonal variation of diarrheal incidence was prominent at the national level (11.63% rise in diarrheal cases in summer (95% CI: 4.17, 19.61) and 14.5% decrease in spring (95% CI: -18.81, -10.02) compared to winter season). Moreover, the effects of temperature and rainfall were highest in the mountain region compared to other ecological regions of Nepal. CONCLUSION: Our study provides empirical evidence linking weather factors and diarrheal disease burden in Nepal. This evidence suggests that additional climate change could increase diarrheal disease incidence across the nation. Mountainous regions are more sensitive to climate variability and consequently the burden of diarrheal diseases. These findings can be utilized to allocate necessary resources and envision a weather-based early warning system for the prevention and control of diarrheal diseases in Nepal