Optical, structural and morphological study of CdS nanoparticles: Role of sulphur source

Cadmium sulfide (CdS) nanoparticles were synthesized by simple and low cost homemade hot injection method at low process temperature using different sulphur sources. The effects of sulphur concentration on the structural, morphological, and optoelectronic properties of synthesized CdS films were studied using a range of characterization techniques: X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and UV-Visible spectroscopy. The XRD studies revealed the formation of hexagonal type CdS nanoparticles. The varying morphology dependence on the sulphur source was ascertained from FESEM analysis. The longitudinal optical (LO) phonon vibrational modes of CdS were assigned in Raman spectra at 300 and 600 cm−1. The band gap of the CdS particles was estimated to be 2.30 eV from Tauc’s plots. Consistent with the experimental results, our first-principles DFT calculations predict the band gap of CdS nanoparticles to increase with decreasing S concentration: Cd52S52 (2.38 eV) Cd52S51 (2.52 eV) and Cd52S50 (2.65 eV), with both the valence and conduction band edges demonstrated to be dominated by S-p states

Synthesis and characterization of chemical spray [yrolysed CZTS thin films for solar cell applications

In present work, thin films of CZTS have been prepared by chemical spray pyrolysis (CSP) by spraying precursor solution directly onto the soda lime glass (SLG) substrates by varying sulphur molar concentration. Copper chloride [CuCl2.2H2O], zinc chloride [ZnCl2.2H2O], tin chloride [SnCl4.5H2O] and thiourea [(NH2)2CS] were used as precursor materials to deposit CZTS thin films by using home-built chemical spray pyrolysis system. Influence of sulphur variation on structural, optical, morphology and electrical properties of CZTS films have been investigated by using variety techniques such as low angle x-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), UV-Visible spectroscopy, four probe method, etc. The formation of CZTS has been confirmed by low angle XRD and Raman spectroscopy. The structural analysis reveals formation of kesterite tetragonal phase with preferential orientation along (112) direction. The band gap values of CZTS thin films have been calculated and found in the range 2 - 2.25 eV over the entire range of sulphur variation studied. The change in band gap may be due to quantum confinement effects at nanoscale. The morphological studies show formation of islands of nanoscale particulate clusters which constitute the films in most of the samples. The films exhibit higher resistivity values (in KΩ) which may be due to presence of the strain in the films

Effects of intrauterine exposure to synthetic glucocorticoids on fetal, newborn, and infant hypothalamic-pituitary-adrenal axis function in humans : a systematic review

BACKGROUND: Synthetic glucocorticoids are commonly used in reproductive medicine. Fetal organ systems are highly sensitive to changes in the intrauterine environment, including overexposure to glucocorticoids. Structural and functional alterations resulting from such changes may persist throughout life and have been associated with diverse diseases. One system that could be particularly sensitive to fetal glucocorticoid overexposure is the hypothalamic-pituitary-adrenal (hpa) axis. Many human studies have investigated this possibility, but a systematic review to identify consistent, emergent findings is lacking. METHODS: We systematically review 49 human studies, assessing the effects of intrauterine exposure to synthetic glucocorticoids on fetal, neonate, and infant hpa function. RESULTS: Study quality varied considerably, but the main findings held true after restricting the analyses to higher-quality studies: intrauterine exposure to synthetic glucocorticoids reduces offspring hpa activity under unstimulated conditions after pain but not pharmacological challenge. Although reduced unstimulated hpa function appears to recover within the first 2 wk postpartum, blunted hpa reactivity to pain is likely to persist throughout the first 4 months of life. There is some evidence that the magnitude of the effects is correlated with the total amount of glucocorticoids administered and varies with the time interval between glucocorticoid exposure and hpa assessment. CONCLUSIONS: This systematic review has allowed the demonstration of the way in which intrauterine exposure to various regimens of synthetic glucocorticoids affects various forms of hpa function. As such, it guides future studies in terms of which variables need to be focused on in order to further strengthen the understanding of such therapy, whilst continuing to profit from its clinical benefits

Ulnar nerve injury due to lateral traction device during shoulder arthroscopy: Was it avoidable?

Most of the nerve injuries reported during shoulder arthroscopy in a beach chair, or lateral position is related to inappropriate patient positioning or excess traction. The lateral decubitus position is more vulnerable for traction-related neuropraxia. The present case serves as an important lesson from an avoidable situation of “having a one track mind” of the surgical team during the arthroscopic repair of shoulder instability performed in the lateral decubitus position. The operating surgeon must supervise the appropriate positioning of the patient on operation table and adequate padding of vulnerable bony points before beginning of shoulder arthroscopy to prevent any position-related nerve injuries. This is probably the first case to illustrate an unusual cause of ulnar nerve compression particularly related to the use of an additional traction device in the arthroscopic repair of shoulder instability performed in lateral decubitus position, which has not been previously defined

Toe salvage procedure for the recurrent chondromyxoid fibroma

The treatment options for recurrent chondromyxoid fibroma of the toe range from total amputation to salvaging a functional toe. There is no globally accepted treatment protocol available for this tumour because of its rarer incidence and lack of population based data. Here we suggest performing a staged approach, which involves en block resection initially and maintenance of metatarsophalangeal space by using a kirshner wire with the bone cement. If there is no sign of malignancy in the histopathology, we recommend performing interposition arthroplasty at the metatarsophalangeal joint with the tricortical iliac crest graft. The kirshner wire should be kept which incorporates the iliac graft and the soft tissue, which is being interposed at the metatarsal head. This will cause pseudoarthrosis and also decreases the chances of having chronic pain. We believe that this staged approach which leads to toe salvage is the best suitable treatment option for the recurrent chondromyxoid fibroma. This will prevent amputation of the toe and will give cosmetic success to the patient

TOE SALVAGE PROCEDURE FOR THE RECURRENT CHONDROMYXOID FIBROMA

The treatment options for recurrent chondromyxoid fibroma of the toe range from total amputation to salvaging a functional toe. There is no globally accepted treatment protocol available for this tumour because of its rarer incidence and lack of population based data. Here we suggest performing a staged approach, which involves en block resection initially and maintenance of metatarsophalangeal space by using a kirshner wire with the bone cement. If there is no sign of malignancy in the histopathology, we recommend performing interposition arthroplasty at the metatarsophalangeal joint with the tricortical iliac crest graft. The kirshner wire should be kept which incorporates the iliac graft and the soft tissue, which is being interposed at the metatarsal head. This will cause pseudoarthrosis and also decreases the chances of having chronic pain. We believe that this staged approach which leads to toe salvage is the best suitable treatment option for the recurrent chondromyxoid fibroma. This will prevent amputation of the toe and will give cosmetic success to the patien

Perceived stress, stigma, and social support among Nepali health care workers during COVID-19 pandemic: A cross-sectional web-based survey.

The COVID-19 pandemic has caused immense psychological distress among Health Care Workers (HCWs). HCWs have been stigmatized by people at their workplace and community, fearing that health care workers are the sources of spreading the virus. This study aimed to assess the perceived stress, stigma, and social support of Nepali health care workers during the COVID-19 pandemic. A web-based cross-sectional survey was conducted among 380 Nepali HCWs. Perceived stress was measured using Perceived Stress Scale (PSS-10). The questionnaire related to stigma was derived from a study conducted to measure stigma among HCWs during the Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak. Furthermore, perceived social support was measured by Oslo Social Support Scale (OSSS-3). Associated factors were examined using Chi-square tests followed by multivariate logistic regression analyses at the significance level of 0.05. This study illustrated that nearly half (44.2%) of the respondents perceived poor social support. Similarly, almost 3% of the HCWs experienced high perceived stress, whereas 87.6% perceived moderate stress, and 35% of the HCWs felt stigmatized. Nepali healthcare workers experienced perceived stress, social stigma, and social support in various severity levels during the COVID-19 pandemic. COVID-19 emergency is emotionally difficult and where psychological distress can jeopardize outcomes and affect work performance. Appropriate psychological interventions are needed to promote the mental well-being of the healthcare workers