Effect of carrier tunneling on the structure of Si nanowires fabricated by metal assisted etching

The metal assisted etching mechanism for Si nanowire fabrication, triggered by doping type and level and coupled with choice of metal catalyst, is still very poorly understood. We explain the different etching rates and porosities of wires we observe based on extensive experimental data, using a new empirical model we have developed. We establish as a key parameter, the tunneling through the space charge region (SCR) which is the result of the reduction of the SCR width by level of the Si wafer doping in the presence of the opposite biases of the p- and n-type wafers. This improved understanding should permit the fabrication of high quality wires with predesigned structural characteristics, which hitherto has not been possible.

Medical Graduates, Tertiary Hospitals, and Burnout: A Longitudinal Cohort Study

BACKGROUND

Burnout among junior doctors can affect patient care. We conducted a longitudinal cohort study designed to explore the incidence of burnout in medical interns and to examine the changes in burnout during the course of the intern year.

METHODS

Interns were recruited at two tertiary hospitals in Brisbane, Australia (n=180). Participants completed surveys at four time points during their internship year. All interns (100%) completed the baseline survey during their orientation. Response rates were 85%, 88%, and 79%, respectively, at 5-week, 6-month, and 12-month follow-up.

RESULTS

Interns reported high levels of personal and work-related burnout throughout the year that peaked at 6 months with mean scores of 42.53 and 41.81, respectively. Increases of 5.1 points (confidence interval [CI] 2.5,7.7; P=0.0001) and 3.5 points (CI 1.3,5.6; P=0.0015) were seen at 6 months for personal and work-related burnout, respectively. The mean score for patient-related burnout at 12 months was 25.57, and this number had increased significantly by 5.8 points (CI 3.2,8.5; P<0.0001) throughout the year. Correlation with demographic variables (age, sex) were found. The total incidence of burnout was 55.9%.

CONCLUSION

Our study showed that burnout is a common problem among interns. The high incidence of burnout demonstrates the need for appropriate strategies to prevent adverse effects on doctors' quality of life and on the quality of care patients receive.

Diffusion induced effects on geometry of Ge nanowires

We report diffusion induced germanium nanowire growth and its dependence on the Ge evaporation flux. The wires show a growth rate (dL/dt) in agreement with the previously reported models, but detection of anomalies in the grown wires may indicate the prevalence of the direct Ge impinging effect on large diameter wires. Additionally, we demonstrate that change in deposition flux could directly affect the diffusion length of the Ge adatoms on the wire sidewalls. This in turn modifies the geometry of the grown wires by introducing a lateral growth starting from the base of the wire. A detailed understanding of the deposition flux effect on the growth and geometry of wires will result in improved knowledge of physical properties of wires.

Ischemic cardiomyopathy: midterm survival and its predictors

BACKGROUND

the aim of the study was to analyze all-cause mortality and predictors of long-term survival after myocardial revascularization for ischemic cardiomyopathy.

METHOD

data of 101 patients (mean age, 63.86 years; age range, 30-85 years; 92% male), operated on with stable coronary artery disease and left ventricular ejection fraction <30% between April 2000 and June 2010, were analyzed.

RESULTS

operative mortality was 1.9% (2/101). There was a significant improvement in left ventricular ejection fraction from 25.99% ± 3.8% preoperatively to 34% ± 12% postoperatively (p <0.0001). The mean duration of follow-up was 56.3 ± 33 months, and it was 97% complete (98/101). There were 18/96 (18.75%) late deaths. Overall actuarial survival at 1, 3, 5, and 10 years was 96%, 89%, 83% and 75%, respectively. Univariate predictors of late death were preoperative arrhythmia, cerebrovascular disease, peripheral vascular disease, and logistic EuroSCORE. Multivariate predictors of late death were cerebrovascular disease and preoperative arrhythmia.

CONCLUSION

our study suggests that myocardial revascularization for ischemic cardiomyopathy improves left ventricular ejection fraction and is associated with favorable long-term survival. Patients with cerebrovascular disease and preoperative arrhythmias had poorer outcomes.

A randomized clinical trial of adjuvant chemotherapy with doxorubicin, ifosfamide, and cisplatin followed by radiotherapy versus radiotherapy alone in patients with localized uterine sarcomas (SARCGYN study). A study of the French Sarcoma Group

BACKGROUND

There is no proven benefit of adjuvant treatment of uterine sarcoma (US). SARCGYN phase III study compared adjuvant polychemotherapy followed by pelvic radiotherapy (RT) (arm A) versus RT alone (arm B) conducted to detect an increase ≥ 20% of 3-year PFS.

METHODS

Patients with FIGO stage ≤ III US, physiological age ≤ 65 years; chemotherapy: four cycles of doxorubicin 50 mg/m&sup2; d1, ifosfamide 3 g/m&sup2;/day d1-2, cisplatin 75 mg/m&sup2; d3, (API) + G-CSF q 3 weeks. Study was stopped because of lack of recruitment.

RESULTS

Eighty-one patients were included: 39 in arm A and 42 in arm B; 52 stage I, 16 stage II, 13 stage III; 53 leiomyosarcomas, 9 undifferenciated sarcomas, 19 carcinosarcomas. Gr 3-4 toxicity during API (/37 patients): thrombopenia (76%), febrile neutropenia (22%) with two toxic deaths; renal gr 3 (1 patient). After a median follow-up of 4.3 years, 41/81 patients recurred, 15 in arm A, 26 in arm B. The 3 years DFS is 55% in arm A, 41% in arm B (P = 0.048). The 3-year overall survival (OS) is 81% in arm A and 69% in arm B (P = 0.41).

CONCLUSION

API adjuvant CT statistically increases the 3 year-DFS of patients with US.

Return to work after coronary artery bypass in patients aged under 50 years

Background: This study was designed to identify factors associated with return to work and quality of life in patients undergoing primary coronary artery bypass at age <50 years.

Methods: 172 patients <50-years old underwent primary coronary artery bypass between January 2000 and December 2006. Predictors of return to work were analysed from variables in a prospectively collected database and on follow-up by the SF-36 questionnaire in 129 (75%) patients.

Results: 136 (79%) patients were working prior to surgery. The educational level was: primary 14.5%, secondary 47%, trade 22%, tertiary 13%, and postgraduate 3%. Type of occupation was blue collar 51%, white collar 41%, pensioner 27%, and unspecfied 8%. The mean follow-up was 86.4 ± 23.4 months. One hundred and twenty-six (69%) patients attended cardiac rehabilitation. Forty (23%) patients experienced recurrence of symptoms; 11 (6%) required reintervention. One hundred and twenty-seven (93%) patients returned to work postoperatively. Univariate predictors of return to work were male sex, blue-collar work, and working prior to surgery. Independent predictors of return to work were working prior to surgery and blue-collar work. Patients who returned to work had significantly higher scores in all 8 domains on the SF36-Questionnaire compared to those who did not return to work.

Conclusions: Preoperative employment and blue collar occupation were associated with a higher rate of return to work after coronary artery bypass in patients of working age. Patients who returned to work had significantly better measured quality of life than those who did not.