获取高质量生物样品图象的电镜技术浅析

获取高分辨率和高反差的生物样品电镜图象受许多因素的影响,它包括切片厚度的选择,电镜的校直合轴、加速电压的选择、以及聚焦方法和曝光时间等。除生物样品制备技术这一重要因素外,必须考虑到上述各因素间的相互关系及其综合选择、然后才有可能获得高质量的生物样品的超微结构图象。     

深圳市2017年-2019年常住居民恶性肿瘤死因分析

目的 分析深圳市恶性肿瘤死亡特征和分布情况,为政府制定恶性肿瘤的防控策略提供参考依据.方法 采用国际疾病分类标准(ICD-10)进行编码分类,运用描述流行病学研究,对2017年1月1日-2019年12月31日深圳市常住居民恶性肿瘤10 612例死亡病例进行分析,分别计算死亡率、死因顺位等.结果 2017年-2019年间...     

Sleep‐disordered breathing in heart failure patients with different etiologies

BackgroundThe prevalence of sleep‐disordered breathing (SDB) is closely related to the severity of heart failure (HF), and the severity of HF is different in patients with HF of different etiologies. Hypothesis: This study aimed to explore the prevalence of SDB in patients with HFof different etiologies.MethodsHospitalized HF patients were consecutively enrolled. All patients underwent portable overnight cardiorespiratory polygraphy. Patients were divided into five groups according to the etiology of HF: ischemic, hypertensive, myocardial, valvular, and arrhythmic. The prevalence of SDB and clinical data was compared among the five groups.ResultsIn total, 248 patients were enrolled in this study. The prevalence of SDB in HF was 70.6%, with the prevalence of obstructive sleep apnea (OSA) at 47.6% and central sleep apnea (CSA) at 23.0%. Patients were divided into five groups: ischemic, hypertensive, myocardial, valvular, and arrhythmic. The prevalence of SDB among the five groups was 75.3%, 81.4%, 77.8%, 51.9%, and 58.5% (p = .014), respectively. The prevalence of OSA among the five groups was 42.7%, 72.1%, 36.1%, 37.0%, and 49.1% (p = .009), whereas the CSA was 32.6%, 9.3%, 41.7%, 14.8%, and 9.4% (p < .001), respectively.ConclusionsSDB is common in HF patients. The prevalence and types of SDB varied in HF with different etiologies, which may be related to the different severities of HF. SDB was highly prevalent in patients with ischemic, hypertensive, and myocardial HF. Hypertensive HF patients were mainly complicated with OSA, while myocardial HF patients were mainly complicated with CSA. Both conditions were highly prevalent in ischemic HF patients. The prevalence of SDB was relatively low in valvular and arrhythmic HF patients, and OSA was the main type.     

Theoretical and Experimental Models to Evaluate the Possibility of Corrosion Resistant Concrete for Coastal Offshore Structures

This study built theoretical and practical models to evaluate the corrosion resistance of concrete for coastal offshore structures in Vietnam. A mathematical model was developed in the form of a system of nonlinear partial differential equations characterizing the diffusion “free calcium hydroxide” in a solid of a concrete structure. The model describes the process of non-stationary mass conductivity observed in the “concrete structure—marine environment” system under non-uniform arbitrary initial conditions, as well as combined boundary conditions of the second and third kind, taking into account the nonlinear nature of the coefficients of mass conductivity k and mass transfer β. It was shown that the solution of the boundary value problem of non-stationary mass conductivity allows us to conclude about the duration of the service life of a concrete structure, which will be determined by the processes occurring at the interface: in concrete—mass conductivity, depending on the structural and mechanical characteristics of hydraulic structures, and in the liquid phase—mass transfer, determined by the conditions of interaction at the interface of the indicated phases.     

P2Y12 inhibitor pretreatment in patients with nonST-segment elevation acute coronary syndrome: A meta-analysis

Background:The 2020 European Society of Cardiology guidelines do not recommend pretreatment for nonST-segment elevation myocardial infarction (NSTEMI) patients with unclear coronary anatomy, which is inconsistent with our routine preoperative approach to loading P2Y12 receptor inhibitors (e.g., preoperative loading of 300 mg of clopidogrel).Objectives:The purpose of our study was to compare the safety and effectiveness of P2Y12 inhibitors administered before coronary angiography or at least before percutaneous coronary intervention (PCI) with during or after PCI.Methods:Cochrane, PubMed, and Embase databases were searched. The primary effect endpoint and safety endpoint were any-cause death and major bleeding, respectively. Major adverse cardiovascular events, myocardial infarction and revascularization were also analyzed.Results:Our search identified 9 trials. P2Y12 inhibitor pretreatment was associated with lower death from any cause (OR 0.62, 95% CI 0.53–0.72, P < 0.00001) without increasing the risk of bleeding (OR 1.02, 95% CI 0.80–1.30, P = 0.89). However, prasugrel or ticagrelor pretreatment was not associated with a lower risk of mortality (OR 0.70, 95% CI 0.31–1.59, P = 0.40) and increased the risk of bleeding (OR 1.67, 95% CI 1.10–2.54, P = 0.02).Conclusions:In summary, clopidogrel pretreatment was associated with significantly lower mortality, major adverse cardiovascular events, myocardial infarction and revascularization with no increase in major bleeding. However, these advantages were not observed with prasugrel or ticagrelor pretreatment.     

Neoadjuvant chemotherapy endows CD9 with prognostic value that differs between tumor and stromal areas in patients with pancreatic cancer

BackgroundThe selective pressure imposed by chemotherapy creates a barrier to tumor eradication and an opportunity for metastasis and recurrence. As a newly discovered stemness marker of pancreatic ductal adenocarcinoma (PDAC), the impact of CD9 on tumor progression and patient''s prognosis remain controversial.MethodsA total of 179 and 211 PDAC patients who underwent surgical resection with or without neoadjuvant chemotherapy, respectively, were recruited for immunohistochemical analyses of CD9 expression in both tumor and stromal areas prior to statistical analyses to determine the prognostic impact and predictive accuracy of CD9.ResultsThe relationship between CD9 and prognostic indicators was not significant in the non‐neoadjuvant group. Nevertheless, CD9 expression in both tumor (T‐CD9) and stromal areas (S‐CD9) was significantly correlated with the clinicopathological features in the neoadjuvant group. High levels of T‐CD9 were significantly associated with worse OS (p = 0.005) and RFS (p = 0.007), while positive S‐CD9 showed the opposite results (OS: p = 0.024; RFS: p = 0.008). Cox regression analyses identified CD9 in both areas as an independent prognostic factor. The T&S‐CD9 risk‐level system was used to stratify patients with different survival levels. The combination of T&S‐CD9 risk level and TNM stage were accurate predictors of OS (C‐index: 0.676; AIC: 512.51) and RFS (C‐index: 0.680; AIC: 519.53). The calibration curve of the nomogram composed of the combined parameters showed excellent predictive consistency for 1‐year RFS. These results were verified using a validation cohort.ConclusionNeoadjuvant chemotherapy endows CD9 with a significant prognostic value that differs between tumor and stromal areas in patients with pancreatic cancer.     

冻融后移植的小鼠卵巢组织对促性腺激素的反应

目的 探讨冻融后移植的小鼠卵巢组织对促性腺激素的反应.方法 将36只性成熟雌性小白鼠随机分为新鲜移植组、冻融移植组和对照组,每组12只.新鲜移植组小鼠切除双侧卵巢,将卵巢切成小组织块,立即移植人双侧肾被膜下;冻融移植组小鼠切除双侧卵巢,将卵巢切成小组织块,采用玻璃化冷冻方法冷冻保存,2周后将冷冻卵巢组织复苏,移植入小鼠双侧肾被膜下.卵巢组织移植2周后,新鲜移植组和冻融移植组每组随机取6只小鼠应用7.5 IU人绝经期促性腺激素及10 IU绒毛膜促性腺激素,观察移植后的卵巢组织对促性腺激素的反应.同时应用免疫组化染色方法观察各组卵泡中卵泡刺激素受体的表达情况.结果 新鲜移植组、冻融移植组和对照组未应用促性腺激素小鼠卵巢组织内近成熟卵泡百分率分别为2.3%、2.3%和2.6%,应用促性腺激素小鼠卵巢组织内近成熟卵泡百分率分别为4.2%、4.0%和5.8%,各组内分别比较,差异均有统计学意义(P＜0.05);新鲜移植组和冻融移植组与对照组比较,差异均元统计学意义(P＞0.05).新鲜移植组、冻融移植组和对照组卵泡刺激素受体表达积分吸光度值在窦状卵泡中分别为9408±2777、9175±3093和8838±2064,在窦前卵泡中分别为4531±1903、4808±1386和5516±1136,各组间分别比较,差异均无统计学意义(P＞0.05).结论 卵巢组织冷冻保存、复苏及移植过程未影响卵巢卵泡刺激素受体的表达,冻融后移植的小鼠卵巢组织对外源性促性腺激素的反应未受冷冻、复苏及移植等过程影响.     

不同剂量甘露醇单用或合用速尿治疗颅高压的疗效观察

目的观察不同剂量甘露醇单用或合用速尿治疗颅高压的疗效。方法对60例各种原因行脑外科手术后出现颅内压增高的患者、依据使用不同剂量甘露醇单用或加用速尿而分为半量甘露醇(0.5 g/kg)组(A组)、全量甘露醇(1.0 g/kg)组(B组)、半量甘露醇 速尿(20 mg)组(C组)及全量甘露醇 速尿(20 mg)组(D组),通过颅内压监测,观察各组降低颅内压的效率、血浆渗透压及肾功能改变。结果(1)在降低颅内压的有效率、颅内压反跳率、药效持续时间上,C、D组明显优于A、B组(均P<0.05);降压幅度4组间差异无显著性。(2)连续降颅压治疗第5 d及第7 d时,各组均出现血浆渗透压的升高,与C组相比,B、D组升高更明显(P<0.05~0.01)。(3)连续使用甘露醇第5 d、7 d,与C组相比,B、D组血尿素氮、肌酐明显升高(均P<0.05)。结论半量甘露醇 速尿治疗颅内压增高疗效佳、安全性高。     

神经内镜手术对幕上高血压性脑出血患者的疗效分析：一项单中心、回顾性、对照研究

目的：探讨神经内镜手术治疗幕上高血压性脑出血的效果。方法 ：回顾性选取2022年1月至2022 年12月我中心收治的42例幕上高血压性脑出血手术患者,以治疗方式分为神经内镜组和开颅手术组。神经内镜组患者采用神经内镜手术治疗,共22例;开颅手术组患者采用传统开颅手术,共20例。对比两组患者术后残余血肿量、术后3月mRS评分、死亡率及并发症率。结果：神经内镜组的术后残余血肿量小于15ml的患者比率77.3%（17/22）高于开颅手术组35.0%（7/20）,差异有统计学意义（P=0.022）;神经内镜组和开颅手术组的患者中,术后3个月预后良好的患者分别为14例（63.6%）和4例（20.0%）,差异有统计学意义（P<0.001）;开颅手术组中,1名（5.0%）患者发生了术后再出血,而神经内镜组中,1名（4.5%）患者发生了术后再出血,差异有统计学意义（P=0.001）;两组手术患者的肺部感染发生率均为100%,差异无统计学意义（P=1.000）;神经内镜组的术后死亡率13.6%（3/22）也低于开颅手术组30.0%（6/20）,差异有统计学意义（P<0.001）。结论：神经内镜手术治疗可提高幕上高血压性脑出血患者的血肿清除率,降低并发症发生率及死亡率,改善患者预后。     

The Relationship between Fat Mass Percentage and Glucose Metabolism in Children and Adolescents: A Systematic Review and Meta-Analysis

To assess the relationship between fat mass percentage (FMP) and glucose metabolism in children aged 0–18 years we performed a systematic review of the literature on Medline/PubMed, SinoMed, Embase and Cochrane Library using the PRISMA 2020 guidelines up to 12 October 2021 for observational studies that assessed the relationship of FMP and glucose metabolism. Twenty studies with 18,576 individuals were included in the meta-analysis. The results showed that FMP was significantly associated with fasting plasma glucose (FPG) (r = 0.08, 95% confidence interval (CI): 0.04–0.13, p < 0.001), fasting plasma insulin (INS) (r = 0.48, 95% CI: 0.37–0.57, p < 0.001), and homeostasis model assessment (HOMA)- insulin resistance (IR) (r = 0.44, 95% CI: 0.33–0.53, p < 0.001). The subgroup analysis according to country or overweight and obesity indicated that these associations remained significant between FMP and INS or HOMA-IR. Our results demonstrated that there is a positive relationship between FMP and FPG. Moreover, subgroup analysis according to country or overweight and obesity indicated that FMP is significantly associated with INS and HOMA-IR. This is the first known systematic review and meta-analysis to determine the associations of FMP with glucose metabolism in children and adolescents.