The synthesis of CuxS from Cu layers by low pressure plasma processing

A new method of converting Cu layers to CuxS on glass at low pressure using an electron cyclotron resonance plasma and SF6 gas is presented. The process operates at low temperatures and short time scales. Trends in film crystallinity and morphology are identified in relation to process time and temperature. These show that sulphurisation is most likely complete within 10 min and that the sulphur content of the films reduces as the conversion temperature is increased from 473 to 623 K. Optical measurements show that the films have a direct bandgap of ∼2.5 eV which is consistent with published values for CuxS films grown by other techniques. Analysis by SEM has revealed that the films possess a complicated structure of platelets covering a denser underlying film. This may account for the differences in observations made by XRF and Raman spectroscopy, which both indicated a mixture of CuS and Cu2S, and X-ray diffraction which predominantly showed CuS

Fabrication and characterisation of Si micropillar PV structures

Arrays of vertical silicon micropillar radial junction solar cells have been fabricated by diffusion of direct application spin on dopant and from the vapour phase through proximity rapid thermal diffusion. The micropillars were fabricated by optical lithography and deep reactive ion etching. The micropillar arrays show superior antireflective properties over the measured spectrum and good correlation to finite difference time domain modelling of identical geometry arrays. Junctions formed by a conventional spin on doping process of phosphorus containing dopant solution produced Suns-Voc values in the region of 0.3 V. This value is likely due to difficulties encountered in achieving an even distribution of dopant over the entire surface of the arrays. An alternative method utilising spin on dopant but employing an intermediate vapour phase diffusion step produced promising results with Suns-Voc values reaching 0.5 V following a post-diffusion drive-in step

Fabrication and characterisation of Si micropillar PV structures

Arrays of vertical silicon micropillar radial junction solar cells have been fabricated by diffusion of direct application spin on dopant and from the vapour phase through proximity rapid thermal diffusion. The micropillars were fabricated by optical lithography and deep reactive ion etching. The micropillar arrays show superior antireflective properties over the measured spectrum and good correlation to finite difference time domain modelling of identical geometry arrays. Junctions formed by a conventional spin on doping process of phosphorus containing dopant solution produced Suns-Voc values in the region of 0·3 V. This value is likely due to difficulties encountered in achieving an even distribution of dopant over the entire surface of the arrays. An alternative method utilising spin on dopant but employing an intermediate vapour phase diffusion step produced promising results with Suns-Voc values reaching 0·5 V following a post-diffusion drive-in ste

Toward a Consistent Description of the PNC Experiments in A=18-21 Nuclei

The experimental PNC results in $^{18}$F, $^{19}$F, $^{21}$Ne and the current theoretical analysis show a discrepancy . If one interprets the small limit of the experimentally extracted PNC matrix element for $^{21}$Ne as a destructive interference between the isoscalar and the isovector contribution, then it is difficult to understand why the isovector contribution in $^{18}$F is so small while the isoscalar + isovector contribution in $^{19}$F is relatively large. In order to understand the origin of this discrepancy a comparison of the calculated PNC matrix elements was performed. It is shown that the $^{18}$F and $^{21}$Ne matrix elements contain important contributions from 3$\hbar \omega$ and 4$\hbar \omega$ configuration and that the (0+1)$\hbar \omega$ calculations give distorted results.Comment: REVTEX, 16 pages, 1 postscriptum figure uuencoded and appende

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks