血小板衍生膜微粒对内皮细胞增殖及血管生成的影响

目的探讨血小板衍生膜微粒（PMP）对人脐静脉内皮细胞（HUVEC）增殖和鸡胚绒毛尿囊膜（CAM）血管生成的影响。方法在血小板悬液中加1.0U/ml的凝血酶,37℃下作用10min后,800g离心20min,取上清,17000g离心分离出PMP,采用BCA法测定PMP含量（以蛋白含量计）,将HUVEC与不同浓度的PMP和血管内皮细胞生长因子（VEGF）共同孵育培养24h后,采用MTT法测定细胞增殖;将20μl的PMP（40μg/ml）和VEGF（10μl/ml）分别接种于CAM上,孵育72h后,观察PMP对CAM血管生成的影响。结果HUVEC的增殖与PMPs呈剂量依赖关系,在培养液中添加40μg/mlPMP时,HUVEC增殖是空白对照组的（1.83±0.33）倍;而VEGF（10μl/ml）组HUVEC的增殖是空白对照组的（1.91±0.47）倍,两者相比差异无显著性（P〉0.05）。PMP组及VEGF组在接种点周围可见不同程度放射状密集生长的血管网,而对照组无特异性密集血管生成。PMP组及VEGF组的CAM血管分支点数分别为112.5±11.3、128.4±10.0,均显著高于空白对照组82.6±8.1。结论PMP可促进人脐静脉内皮细胞的增殖和CAM血管的生成。     

敲低Bmi-1对鼻咽癌细胞CNE2放射敏感性的影响

目的探讨敲低Bmi-1的表达水平对鼻咽癌细胞CNE2放射敏感性的影响。方法通过实时荧光定量PCR(qRT-PCR)和Western blotting检测4种鼻咽癌细胞株CNE1、CNE2、HNE1和HONE1中Bmi-1的表达,筛选出高表达Bmi-1的细胞株。设计3条针对Bmi-1 mRNA的干扰序列(shRNA1、shRNA2、shRNA3),用于构建慢病毒重组载体Bmi-1-shRNA1、Bmi-1-shRNA2、Bmi-1-shRNA3,然后转染至高表达Bmi-1的细胞株中,筛选出敲低Bmi-1效果最佳的慢病毒重组载体。将筛选出的慢病毒重组载体转染至高表达Bmi-1的鼻咽癌细胞株中,使用2 Gy放射线(IR)进行照射,通过平板克隆形成实验检测细胞增殖情况,流式细胞术检测细胞周期分布及凋亡情况。结果在4种鼻咽癌细胞株中,CNE2细胞的Bmi-1 mRNA表达水平最高(P<0.05),CNE1、CNE2细胞中Bmi-1蛋白表达相对较高(P<0.05)。构建的3条慢病毒重组载体Bmi-1-shRNA1、Bmi-1-shRNA2、Bmi-1-shRNA3均可降低CNE2细胞中...     

A First-Principles Study on the Hydration Behavior of (MgO)n Clusters and the Effect Mechanism of Anti-Hydration Agents

Magnesia-based refractory is widely used in high-temperature industries; its easy hydration is, however, a key concern in refractory processing. Understanding the hydration mechanism of MgO will help in solving its hydration problem. Herein, the hydration behavior of (MgO)_n (n = 1–6) at the molecular level and the effect mechanisms of several anti-hydration agents on the hydration of (MgO)₄ were investigated with first-principles calculations. The results indicated that the following: (1) The smaller the (MgO)_n cluster size, the more favorable the hydration of MgO and the tendency to convert into Mg(OH)₂ crystal; (2) Anti-hydration agents can coordinate with the unsaturated Mg atom of (MgO)₄ to form a bond, increasing the coordination number of Mg, thus reducing its activity when reacting with H₂O; (3) The greater the number of −COOH groups and the longer the chain length in the anti-hydration agents, the better its effect of inhibiting the hydration of MgO. These findings could enhance the understanding of the mechanism of hydration of MgO and provide theoretical guidance for the design of novel anti-hydration agents.     

Vitamin D Status Presents Different Relationships with Severity in Metabolic-Associated Fatty Liver Disease Patients with or without Hepatitis B Infection

Whether the associations between serum vitamin D (VitD) and metabolic-associated fatty liver disease (MAFLD) vary with chronic hepatitis B (CHB) infection has not been well established. This study aims to investigate the relationships between serum VitD and metabolism, liver fat content (LFC) and fibrosis among MAFLD patients with and without CHB. Consecutive subjects (healthy controls: 360, CHB: 684, MAFLD: 521, CHB with MAFLD: 206) were prospectively enrolled between January 2015 and December 2021. Anthropometric, laboratory, imaging, and histological evaluations were conducted, with LFC measured via magnetic resonance imaging-based proton density fat fraction (MRI-PDFF). Serum VitD levels were lower in MAFLD patients than in healthy controls and patients with CHB alone or overlapping with MAFLD (24.4 ± 8.1 vs. 29.0 ± 9.5 vs. 27.4 ± 9.6 vs. 26.8 ± 8.4 ng/mL respectively; p < 0.001 in one-way ANOVA test). After adjusting for confounding factors, including season, hypersensitive C-reactive protein, insulin resistance, liver stiffness measurements, sun exposure, exercise and dietary intake, multivariate linear regression analysis revealed that VitD remained significantly negatively correlated with LFC in MAFLD patients (β = −0.38, p < 0.001), but not in CHB with MAFLD patients. Moreover, quantile regression models also demonstrated that lower VitD tertiles were inversely associated with the risk of insulin resistance and moderate–severe steatosis in the MAFLD group (p for trend <0.05) but not in the MAFLD with CHB group. VitD deficiency was associated with the severity of metabolic abnormalities and steatosis independent of lifestyle factors in MAFLD-alone subjects but not in MAFLD with CHB subjects.     

静脉输注高氧液在心肺复苏中的临床应用

目的:探讨在心肺复苏过程中静脉输注高氧液对心跳停搏患者的作用,评价其在心肺复苏中的应用价值。方法:选择心跳停搏患者46例,分为高氧液组和常规组,每组其他抢救措施相同,高氧液组输入高氧液。观察记录复苏过程中患者自主循环恢复率、存活率、脑复苏率、血气分析和SpO2恢复平均时间、血液流变学的变化。结果:自主循环恢复率、存活率高氧液组明显高于常规组(P<0.05),脑复苏率两组比较无统计学意义(P>0.05),血气分析及SpO2恢复平均时间高氧液组均短于常规组(P<0.05),高氧液组治疗后高、低切粘度与复苏即刻比较差异有显著性(P<0.05)。结论:在心肺复苏过程中静脉输注高氧液对心跳停搏患者的复苏有一定作用,是一种辅助治疗手段。     

内源性大麻素系统对丙戊酸诱导的模型鼠孤独症样行为的影响研究

目的 探讨花生四烯酸甘油酯(2-AG)水平改变对VPA鼠孤独症样行为的影响,为进一步明确孤独症谱系障碍(ASD)病因及发病机制提供依据。方法 以VPA诱导ASD模型鼠为研究对象,将实验鼠分为CON组、VPA组、JZL184急性干预组：VPA+40 mg/kg JZL184组(VPA+40AJ)、JZL184慢性干预组：VPA+1 mg/kg JZL184组(VPA+1RJ)、VPA+3 mg/kg JZL184组(VPA+3RJ)和VPA+10 mg/kg JZL184组(VPA+10RJ)。检测各组大鼠的孤独症样行为,采用液相色谱-质谱联用技术检测大鼠海马组织中内源性大麻素(eCBs)水平,采用Western blot检测eCB系统相关受体及代谢酶表达水平。结果 VPA组2-AG、AEA水平显著低于CON组(P<0.05),JZL184干预后,VPA+3RJ组和VPA+10RJ组2-AG水平显著升高(P<0.05)。与CON组相比,VPA组埋珠数量、自梳时间及自发活动明显增多,同时社交能力指数和社交偏好指数降低(P<0.05);JZL184干预后,VPA+40AJ组...     

不同承力点前牵引颅面骨骼的三维有限元研究

目的：从生物力学的角度比较分析,不同部位承力颅面骨骼前牵引的生物力学变化特点。方法：采用三维有限元方法,建立颅面复合体三维有限元模型,在模型上分别以牙列承力前牵引和梨状孔底骨骼承力的前牵引,比较分析其生物力学变化。结果：以梨状孔底骨骼承力的前牵引,矢向位移面中上1／2前移比牙列承力的前牵引多,面中下1／2位移相对较少,垂直向及侧向位移值均小于牙列承力的前牵引,等效应力集中范围明显小于牙列承力的前牵引,鼻根区压应力减少明显。结论：与传统的牙列承力的前牵引比较,以梨状孔底骨骼承力的前牵引可整体前移上颌,减少上颌的逆向旋转,减少硬腭前部压缩现象。     

种植体直径和长度在Ⅰ类骨质中的优化选择

目的:应用Ansys DesignXplorer模块,研究圆柱形种植体直径和长度同时连续变化对Ⅰ类骨质的颌骨应力影响,为临床选择和设计种植体提供理论依据。方法:建立包含圆柱状种植体的下颌骨Ⅰ类骨质骨块的三维有限元模型,设定种植体直径(D)变化范围为3.0~5.0mm,种植体长度(L)变化范围为6.0~16.0mm,观察D和L变化对颌骨Von Mises应力峰值的影响。同时进行颌骨Von Mises应力峰值对变量的敏感度分析。结果:随着D和L的增加,垂直向加载时,皮、松质骨的EQV应力峰值分别降低了54.5%和70.2%,颊舌向加载时,皮、松质骨的EQV应力峰值分别降低了73.5%和75.1%;当D大于3.8mm同时L大于9.0mm时,应力峰值的响应曲线的切斜率位于-1和0之间;在垂直向加载和颊舌向加载时,变量D比L更易影响皮质骨的EQV应力峰值。结论:种植体的直径比长度更易影响皮质骨的应力大小。从生物力学角度而言,对于Ⅰ类骨质,在临床上选择种植体时,种植体的直径应不小于3.8mm,种植体的长度应不小于9.0mm。     

术前3D打印与三维CT重建对腰椎滑脱症手术中的辅助应用效果

目的 探讨术前3D打印技术与三维CT重建图像在腰椎滑脱症手术中的辅助应用效果.方法 选取本院2017年1月～2018年9月收治的腰椎滑脱症患者78例,简单随机化分为两组,均行腰椎椎弓根钉置入术治疗.3D打印组(39例)术前采用3D打印技术制定手术方案,三维CT组(39例)术前采用传统三维CT重建图像制定手术方案.比较两...     

一例HIV感染者的外籍性伴侣的追踪调查

通过对1例HIV-1抗体阳性人员的外籍性伴侣的追踪调查,进行了出入境人员传染病监测对策思考,建议政府有关部门应加大对外籍人员管理力度,协调出入境、公安、劳动、教育等相关部门各负其职,落实责任,切实将外籍人员管理工作落到实处.