Influence of Al Preflow Time on Surface Morphology and Quality of AlN and GaN on Si(111) Grown by MOCVD

We investigate the influence of A1 preflow time on surface morphology and quality of AIN and GaN. The AIN and GaN layers are grown on a Si （111） substrate by metal organic chemical vapor deposition. Scanning electron microscopy, atomic force microscopy, x-ray diffraction and optical microscopy are used for analysis. Consequently, we find significant differences in the epitaxial properties of AlN buffer and the GaN layer, which are dependent on the AI preflow time. A1 preflow layers act as nucleation sites in the case of AiN growth. Compact and uniform AIN nucleation sites are observed with optimizing A1 preflow at an early nucleation stage, which will lead to a smooth AIN surface. Trenches and AlN grain clusters appear on the AIN surface while meltoback etching occurs on the GaN surface with excessive A1 preflow. The GaN quality variation keeps a similar trend with the AIN quality, which is influenced by AI preflow. With an optimized duration orAl preflow, crystal quality and surface morphology of AIN and GaN could be improved.

Changing trends and influencing factors of the quality of life of chemotherapy patients with breast cancer

Objective： To understand the changing trajectory of quality of life（QOL） during the treatment courses of breast cancer patients during chemotherapy and to investigate the factors in each treatment course that affect QOL.Methods： The M.D. Anderson Symptom Inventory Scale, the Hospital Anxiety and Depression Scale（HADS）, and the Functional Assessment of Cancer Therapy-Breast（FACT-B） scale were used to perform a survey on 174 breast cancer patients who received the TAC（docetaxel, Adriamycin, and cyclophosphamide） chemotherapy regimen before postoperative chemotherapy and 5-7 days after each chemotherapy course.Results： The QOL scores of the breast cancer patients were the lowest before the postoperative chemotherapy（81.2 ± 19.6） and the highest after the second chemotherapy course（94.5 ± 14.4）. After the fourth and fifth chemotherapy courses, the scores were much lower again, with values of 82.7 ± 13.9and 82.6 ± 13.1, respectively. The scores improved again after the sixth chemotherapy course（93.9 ± 18.7）. Furthermore, each treatment course had different related symptoms that affected the QOL of the patients.Conclusions： More attention should be paid to the changing trajectory of QOL of patients in all treatment courses and to the influence of treatment-related symptoms on the QOL of patients; moreover, interventions should be adopted by medical care personnel to increase QOL in cancer patients.

Quality of Sleep at the Ward after Cardiothoracic Surgery

Objective: Sleeping problems are among the issues most mentioned by patients after cardiothoracic surgery. These problems can have a negative effect on duration of the hospital stay and recovery. In the ward of our cardiothoracic surgery department, a study was initiated to assess the quality of sleep after cardiothoracic surgery. The primary objective was to investigate the effect of cardiothoracic surgery on the quality of sleep. The secondary objective was to investigate the quality of sleep. Correlations with perioperative factors and related issues such as the type of surgery and medication were sought. Methods: A consecutive prospective cohort study was initiated (N = 72). The study used validated questionnaires to assess sleep: the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Verran Snyder-Halpern Sleep Scale (VSH) and the Factors Influencing Sleep Quality (FISQ). Results: The PSQI showed that the quality of sleep one month after surgery was inferior to the quality of sleep before surgery (p-value: 0.03). The efficiency of sleep (time spent in bed) was higher after surgery then before surgery (p-value: 0.01). The VSH showed increased impaired sleep on the third night after surgery. The most disruptive factors were not being comfortable in a hospital bed, pain and the noise of medical devices. Conclusions: The quality of sleep after cardiothoracic surgery is worse when compared with the preoperative situation. The chief influencing factors are discomfort in bed, pain and disturbance from medical devices. The use of pain medication does not improve the quality of sleep.