151 research outputs found

    血管内皮生长因子表达与肝癌患者临床病理特征及预后的关系研究

    Get PDF
    目的:研究肝细胞肝癌(HCC)组织中血管内皮生长因子(VEGF)表达与患者临床病理特征及预后的关系。方法:采用免疫组织化学染色法检测79例在广西医科大学附属肿瘤医院行肝癌根治性切除术的HCC患者癌组织中VEGF的表达情况,分析VEGF表达与树突状细胞(DC)浸润程度、肿瘤大小、癌栓、包膜、血清AFP水平及术后肝外转移的关系,随访患者术后生存情况及肿瘤复发情况。结果:79例HCC患者中,VEGF低表达43例(54.4%),高表达36例(45.6%)。VEGF表达与DC浸润程度、肿瘤直径及血清AFP水平有关(P0.05)。VEGF高表达组2年内复发率为83.3%(30/36),明显高于VEGF低表达组的60.5%(26/43),差异有统计学意义(P0.05)。结论:VEGF与癌组织DC浸润程度、肿瘤直径及血清AFP水平有关,其在HCC组织中高表达可能增加肝癌术后短期复发风险,可作为肝癌早期复发预警指标

    Formation and solving for the micro-waves of fly-cut surface introduced by spindle error

    Get PDF
    为分析超精密飞切机床加工表面微波纹的形成机理,研究了主轴回转误差信息提取与表面形貌仿真技术,获取微波纹误差来源并研究解决方案。首先,在超精密飞切机床主轴上搭载五通道在线电容位移检测系统,并对采集到的信号进行误差分析提取。然后,建立飞切加工表面微观形貌三维仿真模型,仿真分析主轴误差引入的加工表面微波纹,并与表面检测结果比对确定误差来源。最后,通过调整主轴电机控制系统抑制该误差。三维仿真和实测结果相吻合,证实超精密飞切机床主轴转速波动导致的回转误差造成了工件表面1 Hz左右的规律性条纹,对主轴转速控制系统进行数字化改造后,基本消除了该因素导致的表面微波纹,表面粗糙度从5 nm以上抑制到2 nm左右,PV值优于10 nm。超精密飞切机床主轴转速波动会对飞切加工表面微观形貌以及表面粗糙度产生显著影响,需至少控制在0.5 r/min以内。In order to find out the formation mechanism of micro-waves on the fly-cut surface,the spindle motion error was sampled and a 3D topography simulation model was compiled. Firstly,a nano-class testing and evaluation system was established on the fly cutting machine,the displacement data was sampled and the spindle motion error was analyzed.Then a 3D surface profile topography simulation model was established to analyze the micro-waves caused by the spindle motion error. The simulated surface was compared with the measured surface to find out the error sources. Finally,the characteristics of spindle were improved by adjusting the control system of the spindle motor. The simulated 3D surface profile topography was similar to that of the measured profile,which verified that the macro-waves was caused by the undulate of the spindle speed. When the spindle characteristics was improved,the macro-waves caused by the spindle motion error almost disappeared,and the surface roughness reduced from more than 5 nm to 2 nm. It is thus concluded that the undulate of ultra-precision fly cutting machine spindle speed causes macro-waves on the work-piece surface,and the undulate spindle speed must less than 0. 5 r / min.基金项目:高档数控机床与基础制造装备《强激光光学元件超精密制造关键装备研制》(2013ZX04006011-102-001

    Preparation and in vitro evaluation of chitosan microspheres containing matrine

    Get PDF
    目的:以壳聚糖为囊材制备苦参碱结肠靶向给药微球及评价其体外释药情况。方法:用乳化化学交联法制备微球,以微球的粒径分布百分数、载药量及包封率为优化指标对影响微球制备的主要因素用正交试验设计优化制备条件;并对最佳制备工艺制得的微球进行3种不同递质(人工胃液、人工肠液及大鼠结肠液)中的体外释放度评价。结果:制得的苦参碱壳聚糖微球在电镜下,球形表面圆整,粒径分布适宜,微球平均粒径为(68.3±2.7)μm,平均载药量为(16.0±0.5)%,平均包封率为(66.3±4.2)%。苦参碱壳聚糖微球在人工胃液中2h不释药;在人工肠液中4h内释放不到1%,96h释药不到10%;在含大鼠结肠内容物的磷酸盐缓冲液(pH6.8)中4h释放10%左右,36h释药近50%,此后释药趋于缓慢,96h释药近80%。结论:苦参碱壳聚糖微球几乎不在上消化道释药,而是在结肠靶向释药。OBJECTIVE To preparate the chitosan microspheres containing matrine for the colon-specific drug delivery and evaluate its release in vitro.METHODS The chitosan microspheres containing matrine were prepared by emulsion-chemical crosslink technique.The better preparation procedure with respect to particles size distribution,embedding rate and drug loading were optimized by the orthogonal experimental design.In-vitro drug release were carried out in the artificial gastric,artificial intestinal and the phosphate buffered saline(pH(6.8)) containing rat colon contents.RESULTS The chitosan microspheres containing matrine was shown to have good spherical geometry,a smooth surface and suitable size distribution under scanning electron micrographs.Average diameter of microspheres was((68.3)±(2.7))μm,drug loading was((16.0)±(0.5))%,embedding rate ((66.3)±(4.2))%.Little release and a little release of matrine from the microspheres were observed in the artificial gastric juice and in the artificial intestinal juice,respectively.However,the release of matrine was markedly increased in the phosphate buffered saline(pH(6.8)) containing rat colon contents,which was near to 10%,50% and 80% at 4 h,36 h and 96 h,respectively.CONCLUSION These findings suggest that the chitosan microspheres containing matrine may be useful a dosage form for colon-specific drug delivery.甘肃省自然科学基金(编号ZS0001-A23-073-Y

    Optimization Electrode of GaN-Based Light-Emitting Diode

    Get PDF
    针对以蓝宝石为衬底的GaN基发光二极管出现的电流扩展不均的问题,采用有限元方法建立了GaN基发光二极管的三维网络模型,并对四种常见结构的器件进行数值模拟,发现影响二极管电流的因素不仅与发光二极管电极的位置有关,而且依赖于器件的结构参数。以电流扩展不均为指标确定出这四种器件中最佳的电极位置分布,同时对最佳电极位置分布的器件进行了结构参数优化,结果表明当p型金属层方块电阻与n型GaN的方块电阻接近时,电流扩展均匀性最好,且p-GaN的接触电阻和厚度越小,电流扩展越不均匀。A 3D networks model of GaN-based LED on sapphire substrate was built by finite element analysis to simulate the non-uniformity current spreading.Analog modeling was done on the four normal device structures,it was found that the factors effected the current of LED were the position of electrode and the parameters of device structure.Considering the practical structures of GaN-based LED,four LED designs were modeled and the optimal electrode distribution was obtained,meanwhile the structure parameters were optimized.It reveals that the smaller contact resistances and the thickness of p-GaN are,the more non-uniformity of current distribution is.国家自然科学基金(60276029);; 国家863计划(2004AA311020和2006AA032409);; 福建省科技项目和基金(2006H0092,A0210006,2005HZ1018

    On-line measurement and evaluation of spindle error motion in ultra precision machine tool

    Get PDF
    为了实现对超精密机床主轴回转误差的在线测试与评价,建立了纳米级在线测试与评价系统。对该系统所采用的测试仪器、干扰抑制、数据处理与指标评价方法进行研究。首先,在某台超精密切削机床上搭建了由5个电容传感器组成的5通道测试模块。接着,以多通道高速数据采集模块实现多通道位移数据模拟量的高速采集。然后,对采集的信号进行必要的干扰信号分离。最后,将5通道位移数据转换为易于理解的轴向误差和径向误差数据,并按照同步误差和异步误差进行分离。测试结果表明:该机床主轴工作转速下的径向同步误差为405 nM,径向异步误差为66 nM;轴向同步误差为59 nM,轴向异步误差为54 nM。能够实现超精密机床主轴回转误差的纳米级在线测试,对于超精密光学加工表面的误差溯源和机床主轴性能分析具有重要意义。In order to realize the on-line measurement and analysis of spindle error motion in ultra precision machine,a nano-class testing and evaluation system is established and its measurement instruments,interference control,data processing,evaluation methods and etc.are investigated.Firstly,a five-channel module consisted of five capacitance sensors is established on an ultra precision cutting machine.All the five channels of the displacement sensors are sampled via a high speed data acquisition system simultaneously.Secondly,the separation of interference signals from displacement sensors has been carried out.Finally,the displacement signals are transformed into radial error and axial error,and are separated as synchronous and asynchronous error.Experimental results indicate that the synchronous error and the asynchronous error in radial direction are 405 nm and 66 nm respectively,and the synchronous error and the asynchronous error in axial direction are 59 nm and 54 nm respectively.It can meet the system demands of nano-class,on-line measurement of ultra precision spindle.Thus,it is of great importance for the optical work piece's surface error tracing,and the spindle's performance analyzing.高档数控机床与基础制造装备“强激光光学元件超精密制造关键装备研制”(2013ZX04006011-102-001

    Effects of mowing plus waterlogging on germination and seedling growth of Spartina alterniflora

    Get PDF
    互花米草(Spartina alterniflora)是我国危害最严重的外来入侵植物之一,探索环保、经济、有效地防治互花米草的技术对保护我国海滩生态环境具有重要意义。本研究通过人工气候室(20~25℃)的盆栽实验,研究刈割与淹水对互花米草萌发和幼苗生长的影响。实验持续4个月,对互花米草地上部分进行了2次刈割,首次刈割是在互花米草生长季结束时,3个月后进行第二次刈割。首次刈割后持续淹水至实验结束,淹水处理设计0、5、10、20 cm四个淹水深度。首次刈割后各淹水处理互花米草根茎上迅速萌发克隆苗,种子的萌发比克隆苗晚约3个月。不同淹水深度对克隆苗的萌发和生长均有抑制作用,克隆苗株数、株高和地上生物量均随淹水深度增加而减少。第二次刈割后各淹水处理均没有再萌发克隆苗,但有少量种子实生苗,其中20 cm水深处理的实生苗数量最少。刈割加淹水可以很好地抑制互花米草的萌发和幼苗生长,据此建议互花米草防治方案为:在春季萌芽前,修筑堤坝,保持淹水20 cm,在营养生长期后期贴地刈割互花米草,继续淹水,第二年重复同样的刈割和淹水。为防止二次入侵,需要在邻近的互花米草分布区同时进行治理。&nbsp;</p

    改良分子信标-双重实时荧光PCR快速检测SARS病毒

    Get PDF
    目的建立改良分子信标-双重实时荧光PCR检测SARS病毒的方法,用于SARS的早期诊断和动物溯源。方法利用改良分子信标技术、装甲RNA和双片段双色荧光技术,根据GenBank公布的SARS病毒聚合酶基因1b的阅读开放框架结构的保守序列,自行设计一对引物和探针,以部分临床标本的酶联吸附实验结果和传统细胞培养方法作为对照,建立分子信标检测SARS病毒的方法。对368份临床标本(咽漱液、血液、粪便、尿液)、52份细胞培养液和50份动物标本进行荧光PCR扩增。结果分子信标检测SARS病毒的方法灵敏度为10~100个拷贝ml,与流感病毒等呼吸道病毒无交叉反应。分子信标检测368份临床标本,20份阳性。其中确诊病例阳性率为21.27%(1047),确诊病例的咽漱液阳性率为43.48%,还分别从粪便和血清中检测到SARS病毒。52份细胞培养液,29份阳性,阳性率为55.77%。50份动物标本,23份阳性,阳性率为46%。结论改良分子信标-双重实时荧光PCR检测SARS病毒方法灵敏度高、特异性强,可用于SARS的临床早期诊断和动物溯源

    养正消积胶囊辅助GP方案治疗晚期非小细胞肺癌临床研究

    Get PDF
    目的观察养正消积胶囊辅助GP方案治疗晚期非小细胞肺癌(NSCLC)的临床疗效。方法采用随机数字表法将89例晚期NSCLC患者分为对照组44例及观察组45例。2组均采用GP方案;观察组并予养正消积胶囊,每次4粒,每日3次,口服。2组均21d为1个周期,连续治疗2个周期,随访1年。观察2组治疗前后Ki67、Bax、Bcl-2蛋白表达及肿瘤标志物[血管内皮生长因子(VEGF)、骨桥蛋白(OPN)、癌胚抗原(CEA)、糖类抗原199(CA199)]、中医症状评分、生活质量评分,比较2组客观缓解率(ORR)、疾病控制率(DCR)、无进展生存时间(PFS),监测不良反应。结果观察组ORR、DCR明显优于对照组(P<0.05)。与本组治疗前比较,观察组治疗后、随访1年VEGF、OPN、CEA、CA199水平明显降低(P<0.05);对照组治疗后上述指标明显降低(P<0.05),随访1年CEA水平明显降低(P<0.05)。与本组治疗前比较,2组治疗后Ki67、Bcl-2蛋白表达明显降低,Bax蛋白表达明显升高(P<0.05);2组治疗后比较,观察组Ki67、Bcl-2蛋白表达低于对照组(P<0.05),Bax蛋白表达高于对照组(P<0.05)。与本组治疗前比较,2组治疗后中医症状评分(神疲乏力、胃纳少馨、腰膝无力、夜尿频多、头晕目眩)、生活质量评分(躯体功能、认知功能、社会功能、情绪功能)明显改善(P<0.05);2组治疗后比较,观察组上述评分改善明显优于对照组(P<0.05)。观察组PFS明显长于对照组(P<0.05),不良反应明显低于对照组(P<0.05)。结论养正消积胶囊辅助GP方案治疗晚期NSCLC可有效降低患者肿瘤标志物水平,改善生存质量,减少吉西他滨和顺铂的不良反应,提高疗效。福建省卫生厅中医药科研专项课题(wst201210

    法学家眼中的和谐社会

    Get PDF
    从现有权威性文献看,“和谐社会”是执政党要追求的一种社会状态,更是一种涉及面极其广泛的治国方略。在这个过程中,法律、法学和法学家的作用举足重轻。面对如此重大议题,法学家应当表达观点、提出诉求、发挥专业功能。基于这种考虑,本刊特邀部分中青年法学家进行了笔谈,希望他们的文章能引起讨论,促进法律界、法学界形成一些基本共识

    Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25

    Get PDF
    阿尔茨海默病(Alzheimer’s disease, AD)是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征(Down’s syndrome, DS)是早发型阿尔茨海默病的一个重要风险因素,作为最常见的智力障碍遗传疾病,厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点,并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能,缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成,厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作,王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持,清华大学董晨教授提供了Usp25基因敲除小鼠,厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao). 该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持
    corecore