胸腔镜下肺部手术后发生广泛皮下气肿的临床分析

目的 探讨胸腔镜下肺部手术后发生广泛皮下气肿的影响因素.方法 回顾性分析2015年10月-2020年10月3314例行胸腔镜下肺部手术后发生广泛皮下气肿患者的临床资料,寻找发生广泛皮下气肿的相关因素,分析皮下气肿的治疗效果.结果 术后广泛皮下气肿发生率为1.90％(63/3314).其中,肺减容、胸腔粘连、合并肺气肿和...     

Preparation and Characterization of In Situ (TiC-TiB2)/Al-Cu-Mg-Si Composites with High Strength and Wear Resistance

This study involved the preparation and characterization of in situ (TiC-TiB₂)/Al-4.7Cu-0.32Mg-0.44Si composites with excellent mechanical and abrasive wear properties. The composites were synthesized in an Al-Ti-B₄C system by combining combustion reaction synthesis with hot-pressed sintering and hot extrusion. The in situ TiB₂ and TiC particles were of multi-scaled sizes ranging from 20 nm to 1.3 μm. The TiB₂ and TiC particles effectively increased the yield strength (σ_0.2), ultimate tensile strength (σ_UTS), hardness (HV), and abrasive wear resistance of the composites. The 40 wt.% (TiC-TiB₂)/Al-4.7Cu-0.32Mg-0.44Si composite exhibited the highest σ_0.2 (569 MPa), σ_UTS (704 MPa) and hardness (286 HV), which were 74%, 51% and 110% higher than those of the matrix alloy, respectively. Compared with the matrix alloy, the abrasive wear resistance of the 40 wt.% (TiC-TiB₂)/Al-4.7Cu-0.32Mg-0.44Si composite was increased by 4.17 times under an applied load of 5 N and Al₂O₃ abrasive particle size of 13 µm. Micro-ploughing and micro-cutting were the main abrasive wear mechanisms for the Al-Cu-Mg-Si alloy and the composites.     

Effect of Volume Fraction of Reinforcement on Microstructure and Mechanical Properties of In Situ (Ti,Nb)B/Ti2AlNb Composites with Tailored Three-Dimensional Network Architecture

The mechanical properties of (Ti, Nb)B/Ti₂AlNb composites were expected to improve further by utilizing spark plasma sintering (SPS) and inducing the novel three-dimensional network architecture. In this study, (Ti, Nb)B/Ti₂AlNb composites with the novel architecture were successfully fabricated by ball milling the LaB₆ and Ti₂AlNb mixed powders and subsequent SPS consolidation. The influence of the (Ti, Nb)B content on the microstructure and mechanical properties of the composites was revealed by using the scanning electron microscope (SEM), transmission electron microscopy (TEM) and electronic universal testing machine. The microstructural characterization demonstrated that the boride crystallized into a B27 structure and the α₂-precipitated amount increased with the (Ti, Nb)B increasing. When the (Ti, Nb)B content reached 4.9 vol%, both the α₂ and reinforcement exhibited a continuous distribution along the prior particle boundaries (PPBs). The tensile test displayed that the tensile strength of the composites presented an increasing trend with the increasing (Ti, Nb)B content followed by a decreasing trend. The composite with a 3.2 vol% reinforcement had the optimal mechanical properties; the yield strengths of the composite at 25 and 650 °C were 998.3 and 774.9 MPa, showing an 11.8% and 9.2% improvement when compared with the Ti₂AlNb-based alloy. Overall, (Ti, Nb)B possessed an excellent strengthening effect and inhibited the strength weakening of the PPBs area at high temperatures; the reinforcement content mainly affected the mechanical properties of the (Ti, Nb)B/Ti₂AlNb composites by altering the α₂-precipitated amount and the morphology of (Ti, Nb)B in the PPBs area. Both the continuous precipitation of the brittle α₂ phase and the agglomeration of the (Ti, Nb)B reinforcement dramatically deteriorated the mechanical properties.     

Survival benefit of resection surgery for lung adenocarcinoma with bone metastases and a post-operative prognosis nomogram establishment and validation

BackgroundSurgical resection is not usually recommended for lung adenocarcinoma (LUAD) patients with bone metastases. However, the criteria for surgery are constantly being adjusted and there is a need to focus on the prognostic role of cancer-directed surgery (CDS) for bone metastatic LUAD patients investigate the factors influencing survival of CDS. We determined the survival benefit of CDS for LUAD patients with bone metastases and to develop a prognostic nomogram to predict overall survival (OS) for patients after surgery.MethodsLUAD patients with bone metastases from the Surveillance, Epidemiology, and End Results (SEER) database between 2010–2015 were included and divided into CDS and non-CDS groups. The propensity score matching (PSM) was used to balance baseline characteristics. We used Kaplan-Meier curves and log-rank tests to compare cancer-specific survival (CSS) and OS between the two groups. Patients underwent CDS were randomly divided into training and validation cohorts to develop and validate a nomogram model to predict postoperative prognosis outcome–OS.ResultsPatients who underwent CDS had a better OS and CSS than those who did not underwent CDS (e.g., 1-year OS rate: 56.9% vs. 30.1%). Independent prognostic factors were selected by Cox regression analysis for CDS patients including age, sex, race, histological grade, N stage, and chemotherapy, and a nomogram was constructed to predict 1-, 2-, and 3-year OS after surgery according to the prognostic factors. The calibration curve and receiver operating characteristic (ROC) curve for the nomogram showed the model had a high predictive accuracy. [Area under the curve (AUC) at 1, 2, and 3 years in the training cohort were 0.735, 0.756 and 0.782, and in the validation cohort were 0.703, 0.758 and 0.836, respectively]. In addition, patients were divided into high-risk and low-risk groups based on prognostic scores, and Kaplan-Meier curves showed significant differences in prognosis between the two groups.ConclusionsThese results indicated that patients with bone metastasis of LUAD received survival benefit from CDS. The prognostic nomograms could assist clinicians in specifying individualized assessments, but further research is needed.     

EPO预处理骨髓间充质干细胞预防大鼠肾移植术后急性排斥反应的初步研究

目的  探讨促红细胞生成素（EPO）预处理骨髓间充质干细胞（BMSC）用于预防大鼠肾移植术后急性排斥反应的作用。方法  将BMSC分为5组,分别为对照组（不含EPO）、A组（EPO终浓度10 IU/mL）、B组（EPO终浓度100 IU/mL）、C组（EPO终浓度500 IU/mL）和D组（EPO终浓度1 000 IU/mL）,每组细胞培养24 h和48 h,采用3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐（MTT）法测定BMSC的细胞增殖率。将BMSC分为2组,分别为BMSC组（不含EPO）和EPO-BMSC组（EPO终浓度500 IU/mL）,每组细胞培养48 h后,采用蛋白印迹（Western blot）法检测各组BMSC表面趋化因子受体（CXCR）4的蛋白表达水平。以Wistar大鼠为供体,SD大鼠为受体,建立肾移植急性排斥反应模型后,将受体鼠随机分为4组,每组6只,分别为对照组（未进行任何干预）、EPO组（术后立即经尾静脉注射1 mL含有500 IU的EPO溶液）、BMSC组（术后立即经尾静脉注射1 mL的1×10⁶/mL BMSC细胞液）、EPO-BMSC组（经尾静脉注射1 mL500 IU/mL EPO体外培养的含有1×10⁶/mL BMSC细胞液）,采用血清肌酐（Scr）试剂盒测定血标本中Scr水平,采用Western blot法检测移植肾组织中干扰素（IFN）-γ和白细胞介素（IL）-4的蛋白表达水平。结果  培养24 h,各组BMSC增殖率比较,差异均无统计学意义（均为P > 0.05）。培养48 h,与对照组比较,C组（EPO终浓度500 IU/mL）的BMSC增殖率较高,差异有统计学意义（P < 0.05）。与BMSC组比较,EPO-BMSC组BMSC表面CXCR4的蛋白表达水平更高（P < 0.05)。肾移植术后1 d,各组受体鼠的Scr水平比较,差异均无统计学意义（均为P > 0.05）;术后5 d,与对照组比较,EPO组、BMSC组和EPO-BMSC组受体鼠的Scr水平均明显降低,差异均有统计学意义（均为P < 0.05）,且EPO-BMSC组受体鼠的Scr水平低于EPO组、BMSC组,差异均有统计学意义（均为P < 0.05）。术后1 d和术后5 d,各组受体鼠移植肾组织中IL-4的蛋白表达水平比较,差异均无统计学意义（均为P > 0.05）。术后1 d,与对照组比较,EPO组、BMSC组及EPO-BMSC组受体鼠移植肾组织中IFN-γ蛋白表达水平和IFN-γ/IL-4均有不同程度降低,差异均有统计学意义（均为P < 0.05）。术后5 d,与对照组比较,EPO组、BMSC组和EPO-BMSC组中IFN-γ蛋白表达水平和IFN-γ/IL-4均有不同程度降低,差异均有统计学意义（均为P < 0.05）,其中EPO-BMSC组中IFN-γ蛋白表达水平和IFN-γ/IL-4均低于EPO组和BMSC组,差异均有统计学意义（均为P < 0.05）。结论  EPO预处理BMSC可预防肾移植术后急性排斥反应,保护移植肾功能。     

原发性开角型青光眼黄斑区视网膜厚度与多焦视网膜电图变化的关系

目的 探讨原发性开角型青光眼（POAG）患者黄斑区视网膜厚度与相对应的视网膜功能改变的关系。方法 对24例（43只眼）POAG患者的早期、进展期和晚期患眼进行光学相干断层扫描（OCT）及多焦视网膜电图（ERG）的检查。所得数据应用SPSS统计分析软件进行处理,并做线性相关分析。结果早期的开角型青光眼患者中OCT所测黄斑区视网膜厚度与mERG1环L波潜伏期有显著性负相关（γ=-0．72,P〈0．05,t=2．936）;晚期POAG患者中OCT所测黄斑区视网膜厚度与mERG2,3环b波潜伏期有显著性负相关（γ=-0．666,γ=-0．702,t=2．676,t=2．956,P〈0．05）;对早期,进展期和晚期的开角型青光眼患者OCT所测黄斑区厚度进行比较,显示早期OCT黄斑厚度与晚期相比有极显著性差异,P〈0．01;进展期与晚期相比有显著性差异,P〈0．05,F=5．018。结论POAG患者黄斑区神经上皮厚度的改变影响了黄斑区局部视网膜的功能状态,主要表现为与mERG的b波潜伏期有一定相关性;早期POAG患者眼底视网膜组织形态学上无明显改变时,视网膜功能已经有了改变,OCT与mERG检查对于POAG临床的早期诊断与治疗具有指导性的意义。     

视网膜新生血管的药物治疗研究进展

全身或局部的病变可导致血—视网膜屏障破坏、血液微循环障碍和血管通透性改变,进一步引起视网膜缺氧,乃至水肿,随之视网膜组织对缺氧发生一系列代偿性反应,在各种细胞因子、细胞内外调控机制的共同作用下生成新生血管,目的是补偿缺血缺氧的视网膜。视网膜新生血管相关疾病包括糖尿病性视网膜病变、视网膜静脉周围炎、早产儿视网膜病变等。抑制新生血管生长是治疗这类疾病的关键。本文对抑制视网膜新生血管药物的研究进展作一综述。     

小鼠视网膜新生血管模型的建立及特征

目的:建立可靠稳定的视网膜新生血管动物模型,为今后探究视网膜新生血管疾病的发生机制和治疗方法奠定模型基础。方法:将24只新生C57BL/6J小鼠随机分为正常组和模型组,每组各12只。将模型组小鼠于生后第7d置于750mL/L氧浓度环境,生后第12d返回正常空气中;正常组小鼠始终置于正常空气环境喂养。至小鼠生后第17d进行心脏荧光素灌注造影视网膜铺片以及眼球连续切片苏木精-伊红(H-E)染色,观测视网膜新生血管生成情况。结果:模型组小鼠心脏荧光素灌注造影结果显示视网膜中央区域呈无灌注缺血,另外视网膜血管有迂曲扩张、荧光渗漏等异常表现。眼球连续切片发现模型组小鼠突出视网膜内界膜的血管内皮细胞核数为48.65±6.24个/片/眼,而正常组小鼠平均为0.38±0.21个/片/眼,两组比较差异有显著统计学意义(P<0.01)。结论:氧诱导的视网膜缺血模型可成功诱导小鼠产生视网膜新生血管,可作为探究视网膜新生血管疾病发生机制和治疗方法的可靠动物模型。     

基于全脑影像组学的阿尔茨海默病诊断研究

目的：探讨构建影像组学、临床和联合模型,对正常认知（cognitively normal,CN）组、轻度认知障碍（mild cognitive impairment,MCI）组和阿尔茨海默病（Alzheimer’s disease,AD）组的分类价值。方法：选取阿尔茨海默病神经影像学倡议（Alzheimer’s Disease Neuroimaging Initiative,ADNI）数据库中139例CN、162例MCI和128例AD患者基线的临床和影像资料。以7∶3的比例随机分为训练集和验证集。基于3D-T1WI磁共振成像（magnetic resonance imaging,MRI）提取影像组学特征。在训练集中,使用套索回归算法（least absolute shrinkage and selection operator,LASSO）筛选组学特征,并通过多因素逻辑回归建立基于全脑皮层及皮层下核团的影像组学模型。使用单因素逻辑回归和多因素逻辑回归获得与分类相关的临床指标,并通过多因素逻辑回归模型建立临床模型和基于影像组学特征和临床指标的联合模型。用受试者工作特征（receiver ...     

CT技术诊断下肢动脉硬化闭塞症的应用进展

CT血管成像技术(CTA)在下肢动脉硬化闭塞症诊断中的应用日益广泛。该技术相对其他方法来说具有无创、简便等明显优势。数字减影血管造影以往被认为是诊断动脉硬化性疾病的唯一可靠方法, 而目前CTA技术对这个老的“金标准”提出了挑战。多源CT的应用使全动脉树形结构的无创成像成为可能, 该技术的优化令动脉硬化性疾病的诊断更加精准。对比剂的应用和仪器参数的优化, 使CTA检查的照射剂量明显降低。今后, 随着CT技术的快速发展, CTA技术必将成为诊断下肢动脉闭塞疾病的理想方法。