Effects of gamma-ray irradiation on material and electrical properties of AlN gate dielectric on 4H-SiC.

This article investigates the radiation effects on as-deposited and annealed AlN films on 4H-SiC substrates under gamma-rays. The AlN films are prepared using plasma-enhanced-atomic-layer-deposition on an n-type 4H-SiC substrate. The AlN/4H-SiC MIS structure is subjected to gamma-ray irradiation with total doses of 0, 300, and 600 krad(Si). Physical, chemical, and electrical methods were employed to study the variations in surface morphology, charge transport, and interfacial trapping characteristics induced by irradiation. After 300 krad(Si) irradiation, the as-deposited and annealed samples exhibit their highest root mean square values of 0.917 nm and 1.190 nm, respectively, which is attributed to N vacancy defects induced by irradiation. Under irradiation, the flatband voltage (Vfb) of the as-deposited sample shifts from 2.24 to 0.78 V, while the annealed sample shifts from 1.18 to 2.16 V. X-ray photoelectron spectrum analysis reveals the decomposition of O-related defects in the as-deposited AlN and the formation of Al(NOx)ycompounds in the annealed sample. Furthermore, the space-charge-limits-conduction (SCLC) in the as-deposited sample is enhanced after radiation, while the barrier height of the annealed sample decreases from 1.12 to 0.84 eV, accompanied by the occurrence of the SCLC. The physical mechanism of the degradation of electrical performance in irradiated devices is the introduction of defects like N vacancies and O-related defects like Al(NOx)y. These findings provide valuable insights for SiC power devices in space applications.

[Effect of obstructive sleep apnea on the severity of acute coronary syndrome].

Objective: To investigate the effects of obstructive sleep apnea (OSA) on myocardial damage, coronary multi-vessel lesion and postoperative indexes in patients with acute coronary syndrome(ACS). Methods: The patients, admitted to the Second Affiliated Hospital of Soochow University from September 2022 to October 2023 due to chest tightness and pain, diagnosed with ACS and accompanied by emergency/elective percutaneous coronary intervention(PCI)at, were prospectively enrolled. Portable sleep monitor was used to monitor after stabilization of condition(postoperative day 2±1). The patients were divided into the OSA group (AHI≥15/h) and the control group (AHI<15/h) according to apnea-hypopnea index (AHI). The hematologic indices, echocardiographic parameters, coronary vascular scores and postoperative indicators between the groups were compared. Binary logistic regression model was used to analyze the risk factors for muti-vessel lesion in patients with ACS. Results: One hundred and four ACS patients who met the inclusion criteria were ultimately included, including 85 males (81.7%) and 19 females (18.3%), aged (57.3±10.8) years, of whom 48.1% (50/104) were complicated with OSA. Body mass index (BMI), prevalence of hypertension and diabetes, triglyceride (TG), glycosylated hemoglobin A1c (HbA1c) and D-dimer in the OSA group were higher than those in the control group (P<0.05). There were statistically significant differences in sleep parameters between the two groups (P<0.05). The patients in the OSA group exhibited higher troponin T (cTnT) [M(Q1,Q3),54.0 (9.3,343.8) ng/L vs 15.0 (7.8,38.8) ng/L, P<0.05], larger left atrial internal diameters [41.4 (39.3,45.2) mm vs 40.2 (37.1,42.0) mm, P<0.05], more diseased vessels [2 (1, 3) vs 1 (1, 2), P<0.001], a higher percentage of muti-vessel lesion[60.0%(30/50)vs 29.6%(16/54),P<0.05], and a higher incidence of cardiovascular complications during hospitalization[10.0%(5/50)vs 0(0/54), P=0.017]. The results of binary logistic regression analysis suggested that after adjusting for confounders, AHI (OR=1.035, 95%CI: 1.008-1.063, P=0.011) was independently associated with the development of muti-vessel lesion in patients with ACS. Conclusions: ACS patients with OSA suffer more severe myocardial damage, are more likely to develop structural abnormalities of left heart and multi-vessel lesion, and have a higher incidence of postoperative complications. High AHI is a risk factor for multi-vessel lesion in ACS patients.

[Conjecture on the next development direction of colorectal cancer and its minimally invasive surgery].

The surgical treatment of colorectal cancer will be more and more accurate and minimally invasive under the guidance of precision medicine. At the same time, it will derive and evolve non-surgical paths, such as immune checkpoint inhibitors and immune targeted therapy for microsatellite instability high/mismatch repair deficient colorectal cancer, and wait and watch path after neoadjuvant treatment for low advanced rectal cancer. Laparoscopic minimally invasive surgery for colorectal cancer will be gradually iterated by robots, which is the only way to intelligent surgery.

[Mechanisms and clinical management of small bowel obstruction caused by kinking of the jejunojejunal anastomosis after laparoscopic Roux-en-Y gastric bypass].

Currently, obesity and its complications have become increasingly serious health issues. Bariatric surgery is an effective method of treating obesity and related metabolic complications. Among them, Roux-en-Y gastric bypass (RYGB) is still considered the "gold standard" procedure for bariatric surgery. Small bowel obstruction is one of the possible complications after RYGB, and in addition to the formation of intra-abdominal hernias, kinking of the jejunojejunal anastomosis is an important cause of small bowel obstruction. The early clinical symptoms of kinking of the jejunojejunal anastomosis often lack clarity in the early stages. Therefore, early diagnosis, prevention, and effective treatment of kinking of the jejunojejunal anastomosis are challenging but crucial. The occurrence of kinking of the jejunojejunal anastomosis may be related to surgical techniques and the surgeon's experience. The use of anti-obstruction stitch, mesenteric division, and bidirectional jejunojejunal anastomosis may be beneficial in preventing kinking of the jejunojejunal anastomosis. If kinking of the jejunojejunal anastomosis occurs, timely abdominal CT scans and endoscopic examinations should be performed. Gastric and intestinal decompression should be initiated immediately, and exploratory surgery should be prepared.

[Application of modified fusion convergence index in intermittent exotropia].

Objective: To investigate a modified fusional convergence parameter-total convergence amplitude/distance angle and its relationship with exotropia control, stereoacuity, and other visual functions in intermittent exotropia. Methods: The cross-sectional study included children diagnosed with intermittent exotropia at the First Affiliated Hospital of Nanjing Medical University from August 2020 to June 2021. A modification was made by combining total convergence amplitude using synoptophore and distance angle at distance using prism bars to calculate total convergence amplitude/distance angle. Exotropia control at distance and near measured by Office-based Scale for Assessing Control was classified as good control (scale 0-1) and poor control (scale 2-5). Statistical analysis was performed using Spearman correlation analysis, Mann-Whitney U test, Fisher's exact test, χ2 test, logistic regression analysis, and mediation effect analysis. Results: The study included 212 patients, of which 105 (49.5%) were male and 107 (50.5%) were female. The median (interquartile range) age was 9.0 (8.0, 10.0) years. Of 211 cases, 201 (94.8%) had binocular fusional function, while 11 cases (5.2%) did not have binocular fusional function. Among patients with binocular fusional function, inverse correlation was observed between total convergence amplitude and exotropia control scores for both distance (r=-0.427, P<0.001) and near (r=-0.194, P=0.006). Total convergence amplitude/distance angle was an independent predictive factor for exotropia control at distance (OR=0.195; 95%CI, 0.060-0.630; P=0.006) and near (OR=0.252; 95%CI, 0.085-0.746; P=0.013). Stereoacuity at distance (OR=3.110; 95%CI, 1.311-7.379; P=0.010) and near (OR=2.780; 95%CI, 1.401-5.517; P=0.003) were also factors associated with distance exotropia control. Mediation analysis revealed that stereoacuity was not a mediating factor between the ratio and distance control (distance: P=0.066; near: P=0.181). In patients with ratio≥1.5 °/PD, all the 15 patients demonstrated good control. On the contrary, patients with ratio<1.5 °/PD showed worse exotropia control (distance: P=0.001; near: P=0.040) and larger angles of deviation (distance: P<0.001; near: P<0.001). Conclusion: The modified fusional ratio, total convergence amplitude/distance angle, combining synoptophore and prism bars, could be used to evaluate the severity of intermittent exotropia. A higher ratio may be associated with poorer exotropia control. Though it may also be associated with distance exotropia control, stereoacuity is not the mediating factor between the modified ratio and distance exotropia control.

[Construction of a model based on multipoint full-layer puncture biopsy for predicting pathological complete response after neoadjuvant therapy for locally advanced rectal cancer].

Objective: To investigate the value of transanal multipoint full-layer puncture biopsy (TMFP) in predicting pathological complete response (pCR) after neoadjuvant radiotherapy and chemotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to establish a predictive model for providing clinical guidance regarding the treatment of LARC. Methods: In this multicenter, prospective, cohort study, we collected data on 110 LARC patients from four hospitals between April 2020 and March 2023: Beijing Chaoyang Hospital of Capital Medical University (50 patients), Beijing Friendship Hospital of Capital Medical University (41 patients), Qilu Hospital of Shandong University (16 patients), and Zhongnan Hospital of Wuhan University (three patients). The patients had all received TMFP after completing standard nCRT. The variables studied included (1) clinicopathological characteristics; (2) clinical complete remission (cCR) and efficacy of TMFP in determining pCR after NCRT in LARC patients; and (3) hospital attended, sex, age, clinical T- and N-stages, distance between the lower margin of the tumor and the anal verge, baseline and post-radiotherapy serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 concentrations, chemotherapy regimen, use of immunosuppressants with or without radiotherapy, radiation therapy dosage, interval between surgery and radiotherapy, surgical procedure, clinical T/N stage after radiotherapy, cCR, pathological results of TMFP, puncture method (endoscopic or percutaneous), and number and timing of punctures. Single-factor and multifactorial logistic regression analysis were used to determine the factors affecting pCR after NCRT in LARC patients. A prediction model was constructed based on the results of multivariat analysis and the performance of this model evaluated by analyzing subject work characteristics (ROC), calibration, and clinical decision-making (DCA) curves. pCR was defined as complete absence of tumor cells on microscopic examination of the surgical specimens of rectal cancer (including lymph node dissection) after NCRT, that is, ypT0+N0. cCR was defined according to the Chinese Neoadjuvant Rectal Cancer Waiting Watch Database Study Collaborative Group criteria after treatment, which specify an absence of ulceration and nodules on endoscopy; negative rectal palpation; no tumor signals on rectal MRI T2 and DWI sequences; normal serum CEA concentrations, and no evidence of recurrence on pelvic computed tomography/magnetic resonance imaging. Results: Of the 110 patients, 45 (40.9%) achieved pCR after nCRT, which was combined with immune checkpoint inhibitors in 34 (30.9%). cCR was diagnosed before puncture in 38 (34.5%) patients, 43 (39.1%) of the punctures being endoscopic. There were no complications of puncture such as enterocutaneous fistulae, vaginal injury, prostatic injury, or presacral bleeding . Only one (2.3%) patient had a small amount of blood in the stools, which was relieved by anal pressure. cCR had a sensitivity of 57.8% (26/45) for determining pCR, specificity of 81.5% (53/65), accuracy of 71.8% (79/110), positive predictive value 68.4% (26/38), and negative predictive value of 73.6% (53/72). In contrast, the sensitivity of TMFP pathology in determining pCR was 100% (45/45), specificity 66.2% (43/65), accuracy 80.0% (88/110), positive predictive value 67.2% (45/67), and negative predictive value 100.0% (43/43). In this study, the sensitivity of TMFP for pCR (100.0% vs. 57.8%, χ2=24.09, P<0.001) was significantly higher than that for cCR. However, the accuracy of pCR did not differ significantly (80.0% vs. 71.8%, χ2=2.01, P=0.156). Univariate and multivariate logistic regression analyses showed that a ≥4 cm distance between the lower edge of the tumor and the anal verge (OR=7.84, 95%CI: 1.48-41.45, P=0.015), non-cCR (OR=4.81, 95%CI: 1.39-16.69, P=0.013), and pathological diagnosis by TMFP (OR=114.29, the 95%CI: 11.07-1180.28, P<0.001) were risk factors for pCR after NCRT in LARC patients. Additionally, endoscopic puncture (OR=0.02, 95%CI: 0.05-0.77, P=0.020) was a protective factor for pCR after NCRT in LARC patients. The area under the ROC curve of the established prediction model was 0.934 (95%CI: 0.892-0.977), suggesting that the model has good discrimination. The calibration curve was relatively close to the ideal 45° reference line, indicating that the predicted values of the model were in good agreement with the actual values. A decision-making curve showed that the model had a good net clinical benefit. Conclusion: Our predictive model, which incorporates TMFP, has considerable accuracy in predicting pCR after nCRT in patients with locally advanced rectal cancer. This may provide a basis for more precisely selecting individualized therapy.