Design and development of a horizontal contact separated (HCS) test setup for measuring the performance of triboelectric nanogenerator for sustainable energy harvesting applications.

Triboelectric nanogenerators (TENGs) can play a pivotal role in harnessing non-utilized reciprocating motion and convert it into electrical energy that can later be stored in a battery or capacitor to power various Internet of Things-based smart electronic and wearable devices. Herein, we designed a cost-effective instrumental test bed focused on investigating the output performance of a horizontal contact separation mode triboelectric nanogenerator by varying the input parameters, such as applied force, motor speed, triboplate separation, and frequency of instrumental setup. The test bed mainly consists of three major parts: (i) application of force, (ii) tapping of TENG sample, and (iii) output parameters measurement. The output performance in terms of open circuit output voltage (VOC), short circuit current (ISC), and power density of polydimethylsiloxane-based TENG was monitored and optimized by varying the input parameters. A low-cost current measuring circuitry using an operational amplifier integrated circuit has been proposed with 92% accuracy. The maximum value of VOC and ISC was observed to be 254 V and 31.8 µA at a motor speed of 600 rpm, the distance between both the plates was 6 mm, the input applied force of 40 N, and the striking frequency of 3 Hz. The maximum power density of 2.1 W/m2 was obtained at an input impedance of 8 kΩ. The durability of the test bed as well as the TENG sample was also measured for 25 h. The degree of uncertainty was measured for VOC, ISC, and applied force and calculated to be 1.62%, 7.45%, and 6.27%, respectively.

Gonadotropin upregulates intraovarian calpains-1 and -2 during ovarian follicular recruitment in the SD rat model.

Calpain role has been shown in the cumulus cell-oocyte complexes and, corpus luteum. We investigated the association of calpains-1 and -2 in ovarian folliculogenesis using the Sprague-Dawley (SD) rat model and steroidogenesis in the human granulosa cells (hGCs). We induced PCOS in 42-day-old SD rats by letrozole oral gavage for 21 days. Premature ovarian failure (POF) was induced in 21-day-old SD rats by 4-vinylcyclohexene diepoxide (VCD). Ovulation and ovarian hyperstimulatory (OHS) syndrome were induced by pregnant mare gonadotropin (PMSG) + human chorionic gonadotropin (hCG) treatments in 21 days SD rats, respectively. Steroidogenesis is stimulated in human granulosa cells (hGCs) by forskolin and the response of 17-beta-estradiol (E2) on calpains expression was checked in hGCs. The protein expression by immunoblotting and activity by biochemical assay of calpains-1 and -2 showed an oscillating pattern in the ovarian cycle. PMSG-induced follicular recruitment showed upregulation of calpains-1 and -2, but with no change during ovarian function cessation (POF). Upregulated calpain-2 expression and calpain activity was found in the hCG +PMSG-induced ovulation. Letrozole-induced PCOS showed downregulation of calpain-1, but upregulation of calpain-2. PMSG+hCG-induced OHS led to the upregulation of calpain-1. Letrozole and metformin separately increased the expression level of calpains-1 and -2 in the hGCs during luteinization. In conclusion, the expression levels of calpains -1 and -2 are increased with ovarian follicular recruitment by PMSG and calpain-1 is decreased in the PCOS condition, and letrozole and metformin upregulate the expression of calpains-1 and -2 during luteinization in the hGCs possibly via E2 action.

Brain tissue segmentation in neurosurgery: a systematic analysis for quantitative tractography approaches.

Diffusion magnetic resonance imaging (dMRI) is a cutting-edge imaging method that provides a macro-scale in vivo map of the white matter pathways in the brain. The measurement of brain microstructure and the enhancement of tractography rely heavily on dMRI tissue segmentation. Anatomical MRI technique (e.g., T1- and T2-weighted imaging) is the most widely used method for segmentation in dMRI. In comparison to anatomical MRI, dMRI suffers from higher image distortions, lower image quality, and making inter-modality registration more difficult. The dMRI tractography study of brain connectivity has become a major part of the neuroimaging landscape in recent years. In this research, we provide a high-level overview of the methods used to segment several brain tissues types, including grey and white matter and cerebrospinal fluid, to enable quantitative studies of structural connectivity in the brain in health and illness. In the first part of our review, we discuss the three main phases in the quantitative analysis of tractography, which are correction, segmentation, and quantification. Methodological possibilities are described for each phase, along with their popularity and potential benefits and drawbacks. After that, we will look at research that used quantitative tractography approaches to examine the white and grey matter of the brain, with an emphasis on neurodevelopment, ageing, neurological illnesses, mental disorders, and neurosurgery as possible applications. Even though there have been substantial advancements in methodological technology and the spectrum of applications, there is still no consensus regarding the "optimal" approach in the quantitative analysis of tractography. As a result, researchers should tread carefully when interpreting the findings of quantitative analysis of tractography.

Naringenin improves ovarian health by reducing the serum androgen and eliminating follicular cysts in letrozole-induced polycystic ovary syndrome in the Sprague Dawley rats.

Polycystic ovary syndrome (PCOS) is most common in women of reproductive age, giving rise to androgen excess and anovulation, leading to infertility and non-reproductive complications. We explored the ameliorating effect of naringenin in PCOS using the Sprague Dawley (SD) rat model and human granulosa cells. Letrozole-induced PCOS rats were given either naringenin (50 mg/kg/day) alone or in combination with metformin (300 mg/kg/day), followed by the estrous cycle, hormonal analysis, and glucose sensitivity test. To evaluate the effect of naringenin on granulosa cell (hGC) steroidogenesis, we treated cells with naringenin (2.5 µM) alone or in combination with metformin (1 mM) in the presence of forskolin (10 µM). To determine the steroidogenesis of CYP-17A1, -19A1, and 3ßHSD2, the protein expression levels were examined. Treatment with naringenin in the PCOS animal groups increased ovulation potential and decreased cystic follicles and levels of androgens. The expression levels of CYP-17A1, -19A1, and 3ßHSD2, were seen restored in the ovary of PCOS SD rats' model and in the human ovarian cells in response to the naringenin. We found an increased expression level of phosphorylated-AKT in the ovary and hGCs by naringenin. Naringenin improves ovulation and suppress androgens and cystic follicles, involving AKT activation.

Brain disorders: Impact of mild SARS-CoV-2 may shrink several parts of the brain.

Coronavirus (COVID-19) is a highly infectious respiratory infection discovered in Wuhan, China, in December 2019. As a result of the pandemic, several individuals have experienced life-threatening diseases, the loss of loved ones, lockdowns, isolation, an increase in unemployment, and household conflict. Moreover, COVID-19 may cause direct brain injury via encephalopathy. The long-term impacts of this virus on mental health and brain function need to be analysed by researchers in the coming years. This article aims to describe the prolonged neurological clinical consequences related to brain changes in people with mild COVID-19 infection. When compared to a control group, people those who tested positive for COVID-19 had more brain shrinkage, grey matter shrinkage, and tissue damage. The damage occurs predominantly in areas of the brain that are associated with odour, ambiguity, strokes, reduced attention, headaches, sensory abnormalities, depression, and mental abilities for few months after the first infection. Therefore, in patients after a severe clinical condition of COVID-19, a deepening of persistent neurological signs is necessary.

PKC-ßII is downregulated in the premature ovarian failure SD rat model.

We investigated the role of protein kinase c (PKC) -α and -ß during the ovarian follicular dynamics using estrous cycle, gonadotropin-induced ovulation, and antral follicle culture, 4-vinylcyclohexene diepoxide (VCD)-induced premature ovarian failure (POF) in the SD rat models. We found the higher activity of PKC during the proestrus stage along with expression of PKC-α during the estrus and metestrus stages of the estrous cycle while PKC-ß expression was increased during the diestrus, proestrus, and estrus stages. In response to pregnant mare gonadotropin (PMSG)-induced follicular recruitment and ovulation, the phosphorylated (Thr-642) PKC-ß was increased. PKC activity inhibition by hispidin during the proestrus stage resulted in decreased antral follicles and corpus luteum. Treatment with hispidin resulted in the downregulation of granulosa cell (GC) biomarker, follicle stimulating hormone receptor (FSHR) expression in the cultured pre-antral follicle. During the forskolin-induced luteinization of human granulosa cells, the expression level of PKC-α and ß (I and II) was decreased. In the POF condition, the activity of total PKC and the expression levels of PKC-α and ß (I and II) were increased. Immunostaining depicted ubiquitous expression of PKC-α in the ovary during the estrous cycle and POF conditions. Taken together, we conclude the association of PKC-α and -ß (I and II) during ovarian follicular dynamics where the expression level of PKC-α is increased, but the expression level of PKC-ß (I and II) is suppressed in the POF condition in the SD rat model.

Ormeloxifene, a selective estrogen receptor modulator, protects against pulmonary hypertension.

PURPOSE: Protective effect of 17ß-estradiol is well-known in pulmonary hypertension. However, estrogen-based therapy may potentially increase the risk of breast cancer, necessitating a search for novel drugs. This study, therefore, investigated the ameliorative effects of a selective estrogen receptor modulator, ormeloxifene, in pulmonary hypertension. METHODS: Cardiomyocytes (H9C2) and human pulmonary arterial smooth muscle cells (HPASMCs) were exposed to hypoxia (1% O2) for 42 and 96 h, respectively, with or without ormeloxifene pre-treatment (1 µM). Also, female (ovary-intact or ovariectomized) and male Sprague-Dawley rats received monocrotaline (60 mg/kg, once, subcutaneously), with or without ormeloxifene treatment (2.5 mg/kg, orally) for four weeks. RESULTS: Hypoxia dysregulated 17ß-hydroxysteroid dehydrogenase (17ßHSD) 1 & 2 expressions, reducing 17ß-estradiol production and estrogen receptors α and ß in HPASMC but increasing estrone, proliferation, inflammation, oxidative stress, and mitochondrial dysfunction. Similarly, monocrotaline decreased plasma 17ß-estradiol and uterine weight in ovary-intact rats. Further, monocrotaline altered 17ßHSD1 & 2 expressions and reduced estrogen receptors α and ß, increasing right ventricular pressure, proliferation, inflammation, oxidative stress, endothelial dysfunction, mitochondrial dysfunction, and vascular remodeling in female and male rats, with worsened conditions in ovariectomized rats. Ormeloxifene was less uterotrophic; however, it attenuated both hypoxia and monocrotaline effects by improving pulmonary 17ß-estradiol synthesis. Furthermore, ormeloxifene decreased cardiac hypertrophy and right ventricular remodeling induced by hypoxia and monocrotaline. CONCLUSION: This study demonstrates that ormeloxifene promoted pulmonary 17ß-estradiol synthesis, alleviated inflammation, improved the NOX4/HO1/Nrf/PPARγ/PGC-1α axis, and attenuated pulmonary hypertension. It is evidently safe at tested concentrations and may be effectively repurposed for pulmonary hypertension treatment.

Stomatin-like Protein-2 Promotes Aggregation, Colonization and Migration of Endometriotic Cells.

Endometriosis is a chronic gynecological disease in women of childbearing age, which leads to infertility with risk of endometrial and ovarian cancer. The pathogenesis of endometriosis is poorly understood, and cure/treatment for it is not available, except for symptomatic treatment. The recurrence rate of endometriosis is high. SLP-2 is an inner mitochondrial membrane protein whose participation has been explained in cases of endometrial stromal cell growth, differentiation and migration, but its role in endometriosis is yet to be understood. Previous studies have found altered expression of stomatin-like protein 2 (SLP-2) in the serum of endometriotic patients. Therefore, we have studied the possible role of SLP-2 in the development of endometriosis. We found the ubiquitous and high expression of SLP-2 in the endometriotic tissue of both human endometriosis patients and rat endometriosis model. SLP-2 is seen in the glandular epithelial cells and stromal cells in the eutopic/normal or non-endometriosis group endometrium from human subjects. Finding high expression levels of SLP-2 in endometriotic tissue and ovarian cystic cells derived from endometriosis patients, we explored the possible role of SLP-2 in the cell aggregation, colonization, migration, and invasion in the human endometriotic cells associated with the progression of the endometriosis. Transient silencing of SLP-2 by its siRNA hinders endometriotic cells, aggregation, migration, and invasion into the extracellular matrix, which confirms SLP-2 involvement in endometriotic disease onset and progression. This study unravels the ubiquitous expression of SLP-2 in the human ectopic endometrial tissue and its role in the endometriotic cell migration, colonization, aggregation, and invasion leading to endometriosis progression.

A Ketogenic Diet is Effective in Improving Insulin Sensitivity in Individuals with Type 2 Diabetes.

OBJECTIVE: This systematic review looked at different clinical trials that explored the beneficial effect of a ketogenic diet on insulin sensitivity in Type 2 Diabetics, both with and without exercise. It was hypothesized that a ketogenic diet is effective in improving insulin sensitivity in individuals with Type 2 Diabetes, with the greatest effect resulting from a ketogenic diet paired with exercise. METHODS: The databases used when searching were the Directory of Open Access Journals and PubMed for randomized control trials, non-randomized control trials, and prospective longitudinal studies. Results were summarized in an evidence table found in the Appendix. Studies were not limited by study type, age of study participants, gender, ethnicity, language, journal in which the studies were published, or geographic location. One study utilized mouse models. Statistical analysis was not performed. RESULTS: Twelve trials were studied. Three trials studied the role of exercise and a ketogenic diet in the treatment of Type 2 Diabetes. Five trials studied a ketogenic diet compared to another diet in the treatment of Type 2 Diabetes. Two trials studied a ketogenic diet alone in the treatment of Type 2 Diabetes. One trial studied a ketogenic diet in those with pre-diabetes. One trial studied a ketogenic diet in those with pre-diabetes and those diagnosed with Type 2 Diabetes. Every trial utilizing a ketogenic diet showed marked improvement in glycemic control among participants in support of the hypothesis. One study noted that while a ketogenic diet greatly improved glycemic control, it created problems with lipid metabolism and the liver. When pairing a ketogenic diet with exercise, hepatic steatosis was avoided. Eleven studies used adult participants, one used mouse models. One study was a prospective longitudinal study, nine randomized control trials, one nonrandomized control trial, and one observational cohort study. CONCLUSIONS: The studies provide encouraging results. A ketogenic diet consistently demonstrates improved glycemic control in Type 2 Diabetics, and in those at risk of Type 2 Diabetes. However, the studies are limited in their lack of exploration of the effects of a long-term ketogenic diet on the liver, with only one study including this data. Randomized trials looking at the effect of a ketogenic diet on the liver are needed. In addition, there were very few studies found when researching that paired a ketogenic diet with exercise to study both the effect on glycemic control, as well as avoiding potential hepatic steatosis.

Differential Physio-Biochemical and Metabolic Responses of Peanut (Arachis hypogaea L.) under Multiple Abiotic Stress Conditions.

The frequency and severity of extreme climatic conditions such as drought, salinity, cold, and heat are increasing due to climate change. Moreover, in the field, plants are affected by multiple abiotic stresses simultaneously or sequentially. Thus, it is imperative to compare the effects of stress combinations on crop plants relative to individual stresses. This study investigated the differential regulation of physio-biochemical and metabolomics parameters in peanut (Arachis hypogaea L.) under individual (salt, drought, cold, and heat) and combined stress treatments using multivariate correlation analysis. The results showed that combined heat, salt, and drought stress compounds the stress effect of individual stresses. Combined stresses that included heat had the highest electrolyte leakage and lowest relative water content. Lipid peroxidation and chlorophyll contents did not significantly change under combined stresses. Biochemical parameters, such as free amino acids, polyphenol, starch, and sugars, significantly changed under combined stresses compared to individual stresses. Free amino acids increased under combined stresses that included heat; starch, sugars, and polyphenols increased under combined stresses that included drought; proline concentration increased under combined stresses that included salt. Metabolomics data that were obtained under different individual and combined stresses can be used to identify molecular phenotypes that are involved in the acclimation response of plants under changing abiotic stress conditions. Peanut metabolomics identified 160 metabolites, including amino acids, sugars, sugar alcohols, organic acids, fatty acids, sugar acids, and other organic compounds. Pathway enrichment analysis revealed that abiotic stresses significantly affected amino acid, amino sugar, and sugar metabolism. The stress treatments affected the metabolites that were associated with the tricarboxylic acid (TCA) and urea cycles and associated amino acid biosynthesis pathway intermediates. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and heatmap analysis identified potential marker metabolites (pinitol, malic acid, and xylopyranose) that were associated with abiotic stress combinations, which could be used in breeding efforts to develop peanut cultivars that are resilient to climate change. The study will also facilitate researchers to explore different stress indicators to identify resistant cultivars for future crop improvement programs.

miR-149-PARP-2 Signaling Regulates E-cadherin and N-cadherin Expression in the Murine Model of Endometrium Receptivity.

Cadherins play an essential role in the attachment of the blastocyst to the endometrium, a process known as endometrial receptivity. Loss of E-cadherin expression is essential during the process, while the expression level of the other cadherin, N-cadherin, has been reported to be altered in cases of infertility. Both E-cadherin and N-cadherin can be regulated by members of the PARP family. Specifically, PARP-2, which is under the epigenetic control of miR-149, has been observed to promote E-cadherin expression in other human cells. We investigated the roles of E-cadherin and N-cadherin in endometrial receptivity using mouse models for normal endometrial receptivity, pseudopregnancy, and LPS-induced endometrial receptivity failure. E-cadherin and phosphorylated E-cadherin were predominantly expressed during pre-receptive stages as well as in the implantation site of the receptive stage, which were observed reduced during the later stages of implantation in both implantation and non-implantation regions, while N-cadherin was detected only at pre-receptive stages. E-cadherin and N-cadherin were also seen in the uterus during pseudopregnancy, showing a downregulation trend during receptive and post-receptive stages. LPS-induced failed endometrial receptivity showed upregulation of E-cadherin and downregulation of N-cadherin. The E-cadherin expression promoter, GSK-3, was lost and its suppressor, SLUG was upregulated during normal course of endometrial receptivity in mouse model, while GSK-3 was increased during LPS-induced failed embryo implantation. In an in vitro model of embryo implantation, E-cadherin expression is promoted by PARP-2 and regulated by miR-149 epigenetically in human endometrium epithelial cells. In conclusion, E-cadherin is predominantly expressed during pre-receptive stage and promoted by PARP-2, which is regulated by miR-149 in the endometrial epithelial cells.

Introgression of SbERD4 Gene Encodes an Early-Responsive Dehydration-Stress Protein That Confers Tolerance against Different Types of Abiotic Stresses in Transgenic Tobacco.

Salicornia brachiata is an extreme halophyte that commonly grows on marsh conditions and is also considered a promising resource for drought and salt-responsive genes. To unveil a glimpse of stress endurance by plants, it is of the utmost importance to develop an understanding of stress tolerance mechanisms. 'Early Responsive to Dehydration' (ERD) genes are defined as a group of genes involved in stress tolerance and the development of plants. To increase this understanding, parallel to this expedited thought, a novel SbERD4 gene was cloned from S. brachiata, characterized, and functionally validated in the model plant tobacco. The study showed that SbERD4 is a plasma-membrane bound protein, and its overexpression in tobacco plants improved salinity and osmotic stress tolerance. Transgenic plants showed high relative water, chlorophylls, sugars, starch, polyphenols, proline, free amino acids, and low electrolyte leakage and H2O2 content compared to control plants (wild type and vector control) under different abiotic stress conditions. Furthermore, the transcript expression of antioxidant enzyme encoding genes NtCAT, NtSOD, NtGR, and NtAPX showed higher expression in transgenic compared to wild-type and vector controls under varying stress conditions. Overall, the overexpression of a novel early responsive to dehydration stress protein 4-encoding gene (SbERD4) enhanced the tolerance of the plant against multiple abiotic stresses. In conclusion, the overexpression of the SbERD4 gene mitigates plant physiology by enduring stress tolerance and might be considered as a promising key gene for engineering salinity and drought stress tolerance in crops.

Introgression of a novel cold and drought regulatory-protein encoding CORA-like gene, SbCDR, induced osmotic tolerance in transgenic tobacco.

A potent cold and drought regulatory-protein encoding gene, SbCDR was cloned from an extreme halophyte Salicornia brachiata. In vitro localisation study, performed with SbCDR::RFP gene-construct revealed that SbCDR is a membrane protein. Overexpression of the SbCDR gene in tobacco plants confirmed tolerance against major environmental constraints such as salinity, drought and cold, as evidenced by improved chlorophyll contents, plant morphology, plant biomass, root length, shoot length and seed germination efficiency. Transgenic lines also exhibited high accumulation of proline, total sugar, reducing sugar, free amino acid and polyphenol, besides the low level of malondialdehyde (MDA) contents. SbCDR transgenic lines showed better relative water contents, membrane stability index and osmotic water potential. Furthermore, higher expression of ROS scavenging genes was observed in transgenic lines under stress. Moreover, microarray analysis revealed that several host genes were upregulated and downregulated under drought and salt stress conditions in SbCDR transgenic line compared with control (WT) plants. The results demonstrated that the overexpression of the halophytic SbCDR gene has intense effects on the abiotic stress tolerance of transgenic tobacco plants. However, the exact mode of action of SbCDR in multiple abiotic stress tolerance of plants is yet to be unveiled. It is believed that the precise role of SbCDR gene will provide additional information to comprehend the abiotic stress tolerance mechanism. Furthermore, it will appear as a promising candidate gene for improving stress tolerance in different crop plants for sustainable agriculture and crop productivity.

Exploring the effectiveness of incorporating carbon nanotubes into bioengineered scaffolds to improve cardiomyocyte function.

INTRODUCTION: Carbon nanotubes are effective in improving scaffolds to enhance cardiomyocyte function and hold great promise in the field of cardiac tissue engineering. AREAS COVERED: A PubMed and Google Scholar search was performed to find relevant literature. 18 total studies were used as primary literature. The literature revealed that the incorporation of carbon nanotube into biocompatible scaffolds that mimic myocardial extracellular matrix enhanced the ability to promote cell functions by improving physical profiles of scaffolds. Several studies showed improved scaffold conductance, mechanical strength, improvements in cell properties such as viability, and beating behavior of cells grown on carbon nanotube incorporated scaffolds. Carbon nanotubes present a unique opportunity in the world of tissue engineering through reparation and regeneration of the myocardium, an otherwise irreparable tissue. EXPERT OPINION: The high burden of cardiovascular disease has prompted research into cardiac tissue engineering applications. Carbon-nanotube incorporation into extracellular matrix-mimicking-scaffolds has shown to improve cardiomyocyte conductivity, viability, mechanical strength, beating behavior, and have protected them from damage to a certain degree. These are promising findings that have the potential of becoming the focus of future cardiac tissue engineering research.

Poly(ADP-ribose) polymerase-2 is essential for endometrial receptivity and blastocyst implantation, and regulated by caspase-8.

Embryo implantation is a very complex process and several factors play important roles. Using a mouse model, we investigated the functions of PARP-2 and caspase-8 during endometrial receptivity for blastocyst implantation. We found that PARP-2 was upregulated at the receptive stage's implantation region and predominantly expressed in the endometrial stromal region, but downregulated during pregnancy failure and pseudopregnancy. To reinforce the necessity of PARP-2 for embryo implantation, we pharmacologically inhibited PARP-2 'before' & 'after' embryo arrival and observed a reduction in blastocyst implantation. Conversely, elevated caspase-8 expression and activity during pseudopregnancy, delayed implantation, and embryo implantation failure conditions and decreased levels in the decidualization exhibited an inverse pattern with PARP-2, suggesting caspase-8 as a negative regulator for embryo implantation. In vitro caspase-8 downregulates the PARP-2 activity in the mouse endometrial epithelial and stromal cells. These data suggest that PARP-2 and its negative regulation by caspase-8 constitute a crucial step in embryo implantation.

Impact of HfO2 as a Passivation Layer in the Solar Cell Efficiency Enhancement in Passivated Emitter Rear Cell Type.

We report the simulation of high-efficiency c-silicon Passivated Emitter Rear Contact (PERC) type solar cell structure with rear side passivated with HfO2 as a passivating material. Variation in the half length of pyramid has been carried out to investigate its effect on the solar cell electrical characteristics such as fill factor (FF), open circuit voltage (Voc) and efficiency. Aluminum back Surface Field (Al-BSF) and PERC type solar cell with Al2O3 passivation layer structures were also modeled for comparison. Effect of variation in passivation layer (HfO2) thickness (10 and 15 nm) and permittivity (k = 14 and 25) on the solar cell electrical characteristics has been investigated. Result shows the efficiency improvement in the PERC solar cell with HfO2 passivation layer by 0.5941% and 0.983% as compared to the Al-BSF and PERC with Al2O3 passivation layer at 8 µm pyramid half length. Increased series resistance and reduced FF has been observed with the incorporation of passivation layer at the solar cell structure. Negligible effect of passivation layer thickness has been observed on the solar cell electrical parameters whereas the permittivity value does have significant effect.

Medical students' perceptions of their learning environment during clinical years at Chitwan Medical College in Nepal.

BACKGROUND: The educational environment of an institution affects learning and has a significant role in determining students' academic achievement. The objective of the study was to determine the undergraduate medical students' perception about educational environment in clinical years of study utilizing Dundee Ready Education Environment Measure (DREEM) questionnaire. METHODS: A descriptive cross-sectional questionnaire-based study was conducted among fourth and fifth-year medical students toward the end of their 2016 academic year in Chitwan Medical College, Bharatpur, Nepal. The 50-item DREEM questionnaire was used to collect the data. The items were scored based on a 5-point Likert scale. The data were analyzed using SPSS version 20. Scores obtained were expressed as mean±SD. RESULTS: The mean total DREEM score was 122/200. The mean score for Students' Perceptions of Learning, Students' Perceptions of Teachers, Students' Academic Self-Perceptions, Students' Perceptions of Atmosphere, and Students' Social Self-Perceptions were 29.8/48, 25.9/44, 20.3/32, 28.6/48, and 17.27/28, respectively. This shows the environment for learning was satisfactory. There were nine problem areas with a mean score of ≤2. There was no significant difference observed in educational environment subscales scores according to enrollment year, gender, or funding source for education. CONCLUSION: The overall student's perception of the educational environment was satisfactory. Nevertheless, the study revealed some problematic areas in the learning environment which require remedial measures to make the environment more conducive for learning to satisfy the students and achieve a far better outcome.

Recent advances in Staphylococcus aureus infection: focus on vaccine development.

Staphylococcus aureus normally colonizes the nasal cavity and pharynx. After breaching the normal habitat, the organism is able to cause a number of infections at any site of the body. The development of antibiotic resistance has created a global challenge for treating infections. Therefore, protection by vaccines may provide valuable measures. Currently, several vaccine candidates have been prepared which are either in preclinical phase or in early clinical phase, whereas several candidates have failed to show a protective efficacy in human subjects. Approaches have also been made in the development of monoclonal or polyclonal antibodies for passive immunization to protect from S. aureus infections. Therefore, in this review we have summarized the findings of recently published scientific literature to make a concise report.