The Size Effects of Point Defect on the Mechanical Properties of Monocrystalline Silicon: A Molecular Dynamics Study

The molecular dynamics method was used to simulate the fracture process of monocrystalline silicon with different sizes of point defect under a constant strain rate. The mechanism of the defect size on the mechanical properties of monocrystalline silicon was also investigated. The results suggested that the point defect significantly reduces the yield strength of monocrystalline silicon. The relationships between the yield strength variation and the size of point defect fitted an exponential function. By statistically analyzing the internal stress in monocrystalline silicon, it was found that the stress concentration induced by the point defect led to the decrease in the yield strength. A comparison between the theoretical strength given by the four theories of strength and actual strength proved that the Mises theory was the best theory of strength to describe the yield strength of monocrystalline silicon. The dynamic evolution process of Mises stress and dislocation showed that the fracture was caused by the concentration effect of Mises stress and dislocation slip. Finally, the fractured microstructures were similar to a kind of two-dimensional grid which distributed along the cleavage planes while visualizing the specimens. The results of this article provide a reference for evaluating the size effects of point defects on the mechanical properties of monocrystalline silicon.     

Evaluation of different treatment strategies between right-sided and left-sided pneumonectomy for stage I–IIIA non-small cell lung cancer patients

BackgroundThis study aimed to assess the different survival outcomes of stage I–IIIA non-small cell lung cancer (NSCLC) patients who received right-sided and left-sided pneumonectomy, and to further develop the most appropriate treatment strategies.MethodsWe accessed data from the Surveillance, Epidemiology, and End Results database from the United States for the present study. An innovative propensity score matching analysis was used to minimize the variance between groups.ResultsFor 2,683 patients who received pneumonectomy, cancer-specific survival [hazard ratio (HR) =0.863, 95% confidence interval (CI): 0.771 to 0.965, P=0.010] and overall survival (OS; HR =0.875, 95% CI: 0.793 to 0.967, P=0.008) were significantly superior in left-sided pneumonectomy patients compared with right-sided pneumonectomy patients. Cancer-specific survival (HR =0.847, 95% CI: 0.745 to 0.963, P=0.011) and OS (HR =0.858, 95% CI: 0.768 to 0.959, P=0.007) were also significantly longer with left-sided compared to right-sided pneumonectomy after matching analysis of 2,050 patients. Adjuvant therapy could significantly prolong cancer-specific survival (67 versus 51 months, HR =1.314, 95% CI: 1.093 to 1.579, P=0.004) and OS (46 versus 30 months, HR =1.458, 95% CI: 1.239 to 1.715, P<0.001) among left-sided pneumonectomy patients after the matching procedure, while adjuvant therapy did not increase cancer-specific survival for right-sided pneumonectomy patients (46 versus 42 months, HR =1.112, 95% CI: 0.933 to 1.325, P=0.236). Subgroup analysis showed that adjuvant chemotherapy could significantly improve cancer-specific survival and OS for all pneumonectomy patients. However, radiotherapy was associated with worse survival for patients with right-sided pneumonectomy.ConclusionsPneumonectomy side can be deemed as an important factor when physicians determine the most optimal treatment strategies.     

Self-discharge rates in cells have a critical effect on the cycle life of parallel lithium-ion batteries

More than two parameters are adopted to sort the lithium ion cells (LICs) for better performance in the production process, such as capacity, open-circuit voltage (OCV), direct current resistance (DCR), et al. However, more sorting parameters make mass production more complex. In order to solve this conflict, we compare capacity, OCV, DCR, and self-discharge rate (k_OCV) in this paper, investigate their different effects on the cycle life of parallel LICs through analyzing the relationship between component cell variations and the durability of the parallel blocks. We find that the variations of the self-discharge rate in cells significantly affect the discharge capacity retention of the blocks: bigger variation in the cells results in a better cycle life of parallel LICs. Thus, it is prudent to perform cell sorting for the assembly of superior blocks based on the self-discharge rates of the cells.

More than two parameters are adopted to sort lithium ion cells (LICs) for better performance in the production process, such as capacity, open-circuit voltage (OCV), direct current resistance (DCR), et al.     

The effect of solvent on Al-doped ZnO thin films deposited via aerosol assisted CVD

Aluminium-doped zinc oxide (AZO) thin films were deposited via aerosol assisted chemical vapour deposition (AACVD) from zinc acetylacetonate and aluminium chloride at 450 °C. The precursor solutions consisted of methanol in a mixture with one other secondary solvent, including toluene, tetrahydrofuran, n-hexane, cyclohexane, and ethyl acetate. The crystal structures, elemental compositions and surface morphologies of the resulting AZO films were determined, as well as the optoelectronic properties. It was found that the more polar solvents enhanced growth in the (002) plane of the wurtzite crystal structure, and that solutions with low viscosities resulted in superior grain growth. The film deposited from a solution consisting of methanol and ethyl acetate displayed the lowest visible transmittance, due to carbon contamination. However, it also exhibited 60% lower resistivity, in comparison to the film deposited using methanol only. This suggests that optoelectronic properties can be tuned for specific photovoltaic devices.

Aluminium-doped zinc oxide (AZO) thin films were deposited via aerosol assisted chemical vapour deposition (AACVD) from zinc acetylacetonate at 450 °C.     

Randomised controlled trial: effect of metformin add-on therapy on functional cure in entecavir-treated patients with chronic hepatitis B

Introduction and ObjectivesHepatitis B surface antigen (HBsAg) clearance, indicating functional cure or resolved chronic hepatitis B (CHB), remains difficult to achieve via nucleos(t)ide analogue monotherapy. We investigated whether metformin add-on therapy could help achieve this goal in entecavir-treated patients with hepatitis B e antigen (HBeAg)-negative CHB.Patients and MethodsPatients with HBeAg-negative CHB who met eligibility criteria (entecavir treatment for > 12 months, HBsAg < 1000 IU/mL) were randomly assigned (1:1) to receive 24 weeks of either metformin (1000 mg, oral, once a day) or placebo (oral, once a day) add-on therapy. The group allocation was blinded for both patients and investigators. Efficacy and safety analyses were based on the intention-to-treat set. The primary outcome, serum HBsAg level (IU/mL) at weeks 24 and 36, was analysed using mixed models.ResultsSixty eligible patients were randomly assigned to the metformin (n = 29) and placebo (n = 31) groups. There was no substantial between-group difference in the HBsAg level at week 24 (adjusted mean difference 0.05, 95% confidence interval -0.04 to 0.13, p = 0.278) or week 36 (0.06, -0.03 to 0.15, p = 0.187), and no significant effect of group-by-time interaction on the HBsAg level throughout the trial (p = 0.814). The occurrence of total adverse events between the two groups was comparable (9 [31.0%] of 29 vs. 5 [16.1%] of 31, p = 0.227) and no patient experienced serious adverse events during the study.ConclusionAlthough it was safe, metformin add-on therapy did not accelerate HBsAg clearance in entecavir-treated patients with HBeAg-negative CHB.     

儿童支气管肺炎门诊抗菌药物的应用情况分析

目的：调查肇庆市第二人民医院（以下简称本院）儿童支气管肺炎在门诊临床治疗中抗菌药物的应用情况,评价治疗用药方案,为临床合理用药提供参考。方法采用回顾性调查方法,抽查2014年6月1日~2014年9月1日在本院以第一诊断收治入院的支气管肺炎患儿病历171份,调查在入院前门诊应用抗菌药物的情况,对其应用情况进行统计、分析。结果171份住院病历中,经本院门诊治疗的抗生素应用率为47%,院外抗生素应用率为34%。应用的抗菌药物涉及15种四个大类,分别为青霉素类、头孢菌素类、大环内酯类、林可霉素类。联合用药17份,占总数的15%,其中二联用药的有16份,占总数的14%。结论儿童支气管肺炎患者入院前在门诊（院内外）接受抗菌药物治疗较为普遍。该院门诊抗菌药物应用基本合理,但有极个别病例出现联合或序贯用药不当的情况,应加强用药监控。     

慢性阻塞性肺疾病伴认知功能障碍患者血清lipocalin-2表达及意义

目的分析血清脂质运载蛋白-2(lipocalin-2)在慢性阻塞性肺疾病(chronic obstructive pulmonary disease, COPD)稳定期伴认知障碍患者血清中的表达变化及其意义。 方法依据蒙特利尔认知评估量表(Montreal cognitive assessment, MoCA)评分,MoCA分值<26分者为认知受损,将43例COPD稳定期的患者分为认知障碍组23例及认知正常组20例,并选取20例健康体检者做对照组;采用酶联免疫吸附实验(ELISA)分别检测患者外周静脉血清脂质运载蛋白-2(lipocalin-2)水平;分析血清脂质运载蛋白-2与认知功能的相关性,根据血清lipocalin-2水平预测认知障碍的受试者工作特征(ROC)曲线。 结果与健康对照组相比(60.37±10.77)μg/ml,COPD稳定期伴认知障碍患者血清lipocalin-2水平(82.76±12.90)μg/ml显著增加(P<0.05);与COPD稳定期认知正常组(69.70±11.51)μg/ml相比,认知功能障碍组血清lipocalin-2水平显著升高,差别有统计学意义(P<0.05)。Pearson相关分析结果显示血清lipocalin-2水平与MoCA评分呈负相关(r＝-0.749,P<0.001);血清lipocalin-2水平预测COPD稳定期患者认知功能障碍的ROC曲线下面积分别为0.804(95%CI 0.664~0.945,P<0.001)。 结论血清lipocalin-2表达水平与COPD稳定期患者认知功能障碍密切相关。血清lipocalin-2水平检测可能成为COPD患者出现认知功能障碍的一个重要诊断指标。     

Immunotherapy for hepatocellular carcinoma: A promising therapeutic option for advanced disease

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide, and its incidence continues to increase. Despite improvements in both medical and surgical therapies, HCC remains associated with poor outcomes due to its high rates of recurrence and mortality. Approximately 50% of patients require systemic therapies that traditionally consist of tyrosine kinase inhibitors. Recently, however, immune checkpoint inhibitors have revolutionized HCC management, providing new therapeutic options. Despite these major advances, the different factors involved in poor clinical responses and molecular pathways leading to resistance following use of these therapies remain unclear. Alternative strategies, such as adoptive T cell transfer, vaccination, and virotherapy, are currently under evaluation. Combinations of immunotherapies with other systemic or local treatments are also being investigated and may be the most promising opportunities for HCC treatment. The aim of this review is to provide updated information on currently available immunotherapies for HCC as well as future perspectives.