48 research outputs found
Experimental study on correlation of VEGF with corneal neovascular permeability after alkali burn
目的研究大鼠角膜碱烧伤后新生血管渗透率的变化并探讨血管内皮细胞生长常大鼠角膜作为对照。结果正常及碱烧伤后1d、2d、3d、5d、7d、10d大鼠角膜新生血管渗透率依次为0mg.L-1.mm-2,(1.14±0.17)mg.L-1.mm-2,(0.24±0.08)mg.L-1.mm-2,(0.29±0.16)mg.L-1.mm-2,(0.14±0.10)mg.L-1.mm-2,(0.09±0.06)mg.L-1.mm-2和(0.05±0.04)mg.L-1.mm-2;角膜组织中VEGF-RNA水平依次为(1.09±0.31)×106拷贝.μg-1总RNA,(7.01±1.99)×106拷贝.μg-1总RNA,(1.01±0.59)×106拷贝.μg-1总RNA,(2.43±0.43)×106拷贝.μg-1总RNA,(0.99±1.31)×106拷贝.μg-1总RNA,(0.95±0.03)×106拷贝.μg-1总RNA和(0.17±0.15)×106拷贝.μg-1总RNA,其中7d和10d的VEGF-RNA低于正常水平(P7=0.011,P10=0.006)。经Pearson相关分析,新生血管渗透率和VEGF-...
【英文摘要】 Objective To investigate the changes of neovascular permeability,and explore the effect of vascular endothelial growth factor(VEGF)on it after alkali burn.Methods The rat model of alkali burn induced corneal neovascularization(CNV)was constructed.Neovascular permeability was measured by Evans blue method at 1 day,2 days,3 days,5 days,7 days and 10 days after surgery,respectively.Expression of vascular endothelial growth factor(VEGF)was evaluated using real time PCR.Normal corneas were treated as control gro...国家杰出青年科学基金资助(编号:30225044);; 广州市卫生局科学基金资助(编号:2008-YB-053)~
福建省高校高级知识分子亚健康状况调查分析与对策
目的通过了解福建省高校高级知识分子亚健康相关状况,进一步揭示影响他们身心健康的原因和需求,探讨改善该人群健康状况的策略。方法采用整群抽样的方法对我省15所本科院校在职的高级知识分子及科研人员2 454名教师进行问卷调查,并进行统计学分析。结果亚健康者935人,检出率38.10%,其中副高职称者健康状况比正高职称者差。结论我省高校高级知识分子的健康状况较差,应引起各高校的重视。福建省教育厅基金资助项目(JA08065S
化学气相沉积SiC–B_xC涂层在高温模拟环境中的微观结构
将化学气相沉积在石墨基片上的SiC-BxC复合涂层在O2(8kPa)/H2O(14kPa)/Ar(78kPa)的模拟气氛中,分别加热到700,1000℃和1200℃处理10h。利用扫描电镜、X射线衍射、能谱分析、显微Raman和Fourier变换红外光谱仪研究其微观结构。结果表明:复合涂层中的BxC层在700~1000℃的模拟环境中会被完全氧化成B2O3和H3BO3;在1000~1200℃的模拟环境中,BxC层的氧化产物迅速挥发。经高温模拟环境处理后,复合涂层中生成了硼硅酸盐玻璃,且各氧化产物和SiC层的结晶度随处理温度的升高而下降。基于微观分析结果,对SiC-BxC复合涂层的自愈合抗氧化性能进行了分析
Micro-CT analysis of high temperature creep damage of 2D C/SiC composites
利用显微CT针对自愈合2dC/SIC复合材料高温蠕变试验前后的内部孔隙率进行了分。析结果表明,显微CT技术能较好地探测高温蠕变前后2dC/SIC复合材料内部孔隙率变化,从孔隙率的变化初步证实了bXC组元对2dC/SIC复合材料有一定的自愈合作用。利用显微CT技术证实了高温下的拉伸应力不会导致2dC/SIC复合材料中新的裂纹产生。We report a micro-CT experiment that permits us to assess void growth and microstructure development in self-healing 2D C/SiCcomposites subjected to high temperature creep.The results reveal that the micro-CT is a promising facility to detect the evolution of voidsin 2D C/SiC composites,and the BxC composition plays a positive role in the self-healing behavior of the composites subjected to hightemperature.In addition,the results show that high temperature creep will not lead to new cracks in the composites,which may be caused bythe self-healing of matrix cracks.国家自然科学基金重点项目(90405015
2D C/SiC复合材料高温蠕变损伤的显微CT分析
利用显微CT针对自愈合2DC/SiC复合材料高温蠕变试验前后的内部孔隙率进行了分。析结果表明,显微CT技术能较好地探测高温蠕变前后2DC/SiC复合材料内部孔隙率变化,从孔隙率的变化初步证实了BxC组元对2DC/SiC复合材料有一定的自愈合作用。利用显微CT技术证实了高温下的拉伸应力不会导致2DC/SiC复合材料中新的裂纹产生
CVI B-C基体改性2D C/SiC在低温湿氧中的自愈合行为
针对C/SiC低温氧化易失效的不足,研究了CVI B-C基体改性2D C/SiC在700℃湿氧中100MPa下加载至60h的氧化行为,利用SEM和TEM观察了改性材料不同服役时间的微结构特征,揭示了演变规律.研究表明,CVI B-C基体改性使C/SiC低温抗氧化能力显著提升.基体裂纹及其在应力加载下的开裂均为氧化气体提供进入通道,而后可被B-C氧化产物B2O3封填,抑制内部C消耗.CVI B-C与其氧化产物一同参与缺陷愈合.在60h内,B-C改性层愈合能力尚未完全发挥,可服役更长时间
C/SiC表面SiC涂层氧化的显微CT无损检测与分析
对C/SiC复合材料表面SiC涂层在1300℃干氧和湿氧环境中退火处理60 h,利用显微CT技术对高温氧化后的SiC涂层进行无损检测。通过重构SiC涂层不同深度的氧化形貌,并利用SEM、EDS和XRD进行辅助验证,得到沿SiC涂层表面和厚度方向的氧化形貌。结果表明:显微CT能有效地检测氧化后SiC涂层中存在的氧化产物SiO2及其氧化深度,其在表面及深度方向均呈非均匀分布;在干氧环境中SiC涂层的氧化面积沿着涂层的深度方向呈减少趋势,而在湿氧环境中SiC涂层的氧化面积沿着涂层的深度方向呈先增加后递减的趋势,验证了C/SiC复合材料表面SiC涂层在干氧和湿氧中不同的氧化机制
ST段抬高型急性心肌梗死院前溶栓治疗中国专家共识
急性心肌梗死仍然严重威胁我国人民健康,在我国广大城乡地区,形势更为严峻[1,2]。及时救治急性心肌梗死患者,降低死亡率和保护心脏功能刻不容缓。鉴于我国的实际情况,院前溶栓治疗在大城市以外的城乡地区具有重要意义。为此,中国医师协会胸痛专业委员会及中国医学救援协会心血管急救分会专门组织有关专家制订了本共识,旨在帮助院前医疗急救人员对急性心肌梗死患者选择最佳
DISTRIBUTION CHARACTERS AND MODEL of RARE EARTH ELEMENT (REE) IN SURFACE SEDIMENTS FROM LINGDINGYANG AREA of PEARL RIVER ESTUARY
珠江口伶仃洋海区表层沉积物中的稀土元素的含量变化范围较大(170.34~344.60μg/g),平均含量为272.02μg/g,远高于陆壳平均含量(200μg/g)和华南地区花岗岩中稀土元素的平均含量,接近于全球沉积物平均稀土元素含量上限。以轻稀土富集为主,富集系数在1.51~2.43之间。经北美页岩标准化后,伶仃洋海区沉积物配分模式呈负斜率配分型;与南海沉积物中稀土分布具有相似性,说明二者具有同源性。The paper studies the content of Rare Earth Element(REE)in surface sediments from Pearl River Estuary.The content of REE changes from 170 34μg/g to 344 60μg/g.The average content of REE is 272 02μg/g,far higher than the average content of REE in crust and in granite of the South China area.It approaches the average upper limit of REE content in sediments in the world.The higher content of REE in surface sediments from Pearl River Estuary is related to sediment material source from Pearl River valley. The distribution model of REE in surface sediments from Pearl River Estuary shows negative slope model on the basis of standard of shale in North America (NASC).Ce shows a little positive anomaly,but Eu shows a little negative anomaly.The REE accumulation in surface sediments from Pearl River Estuary is mainly LREE accumulation, and the accumulating coefficient is 1 51~2 43.The accumulating degree in surface sediments of Pearl River Estuary is higher than that of Yellow River Estuary,Amazon Estuary and the South China Sea and less than that of East China Sea and Bohai Sea.The distribution model of South China Sea is similar to that of the continent shelf sea in China,especially to that of the South China Sea.It shows surface sediments in Pearl River Estuary have the same material source as in South China Sea. The TREE in surface sediments from Pearl River Estuary is closely related to clay mineral.Further analyzed,the LREE is closely related to kaolinite,MREE and HREE is closely related to gibbsite.But the reasons need further research