内镜下组织胶联合药物注射治疗急性非静脉曲张性上消化道出血的疗效及安全性研究

目的分析内镜下组织胶联合药物注射治疗急性非静脉曲张性上消化道出血(ANVUGIB)的临床效果与安全性。方法选取ANVUGIB患者82例,根据治疗方案分为研究组和对照组,各41例。在常规治疗基础上,对照组给予内镜下金属钛夹治疗或出血病灶黏膜下注射1∶10000的肾上腺素治疗,研究组予内镜下组织胶联合药物注射裸露血管治疗。比较两组的手术指标(输血量、止血时间、住院时间)、临床疗效、止血成功率、再出血率及并发症情况。结果研究组的输血量少于对照组,止血时间及住院时间短于对照组;研究组的总有效率明显高于对照组(97.56%vs.78.05%,均P<0.05);两组患者的止血成功率、迟发性再出血率比较,差异无统计学意义(均P>0.05);研究组的术后早期再出血率明显低于对照组(P<0.05);治疗后1~2个月,两组患者均未出现消化道穿孔以及感染等并发症,预后效果较好。结论内镜下组织胶联合药物注射治疗ANVUGIB的效果显著,可有效减少输血量、缩短止血时间及住院时间,降低患者再出血发生率,且安全性高,值得临床推广应用。

幽门螺杆菌与胃癌关系的研究进展

越来越多的研究表明,幽门螺杆菌定殖胃黏膜后,导致持续漫长的感染与胃癌的发生密切相关,其中幽门螺杆菌吸附于胃黏膜的机制,吸附胃黏膜后胃部黏蛋白的异常表达,及幽门螺杆菌感染后相关炎症因子及毒力因子以多种途径促进胃癌的发生,笔者总结了幽门螺杆菌感染定殖、胃部黏蛋白、炎症因子、毒力因子和胃癌的关系最新进展,旨在为H.pylori感染与胃癌关系的进一步研究提供思路与帮助。

Spatio-temporal Pattern and Spatial Heterogeneity of Ecotones Based oh Land Use Types of Southeastern Da Hinggan Mountains in China

Ecotones have received great attention due to its critical function in energy flux, species harbor, global carbon sequestration, and land-atmosphere interaction. This study investigated land use pattern and spatial heterogeneity of the ecotones among agricultural land, forest land, and grassland of the southeastern Da Hinggan Mountains in the northeastern China. The change of these delineated ecotones under different slopes and aridity conditions was analyzed by two landscape indices, edge density(ED) and core area percentage of landscape(CPL), to explore the inter-linkage between spatial structure of ecotones and socioeconomic development and land management. Specifically, the ecotones such as agriculture-forest(AF) ecotone, forest-grassland(FG) ecotone, and agriculture-forestgrassland(AFG) ecotone moved from the arid southeast to the humid northwest. The flat area with small slope is more edge-fragmented than the steep area since the ED decreases as the slope increases. The AF ecotone mostly found in the humid region is moving to more humid areas while the agriculture-grassland(AG) ecotone mostly found in the dry region is moving towards the drier region.

A MODIS Time Series Data Based Algorithm for Mapping Forest Fire Burned Area

Burned area mapping is an essential step in the forest fire research to investigate the relationship between forest fire and climate change and the effect of forest fire on carbon budgets. This study proposed an algorithm to map forest fire burned area using the Moderate-Resolution Imaging Spectroradiameter (MODIS) time series data in Heilongjiang Province, China. The algorithm is divided into two steps: Firstly, the′core′pixels were extracted to represent the most possible burned pixels based on the comparison of the temporal change of Global Environmental Monitoring Index (GEMI), Burned Area Index (BAI) and MODIS active fire products between pre- and post-fires. Secondly, a 15-km distance was set to extract the entire burned areas near the′core′pixels as more relaxed conditions were used to identify the fire pixels for reducing the omission error as much as possible. The algorithm comprehensively considered the thermal characteristics and the spectral change between pre-and post-fires, which are represented by the MODIS fire products and the spectral index, respectively. Tahe, Mohe and Huma counties of Heilongjiang Province, China were chosen as the study area for burned area mapping and a time series of burned maps were produced from 2000 to 2011. The results show that the algorithm

Comparison and Analysis of Agricultural and Forest Land Changes in Typical Agricultural Regions of Northern Mid-latitudes

The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The western Europe has a longer history of agricultural land development than the eastern United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic benefits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though persistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulnerability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects.

基于行业的城市安全生产风险结构及差异性

风险防治和隐患排查是城市安全的重要组成部分。由于各行业领域中潜在的风险类型和分布存在着很大差异,因此在风险防治工作中需要考虑差异性,并有针对性地制定行业风险防控措施。研究了城市安全生产风险的行业分布差异性,提出了行业安全风险结构的概念,在行业风险分布标准化的基础上定义了行业安全风险向量,基于信息熵理论给出了行业风险熵和风险特异度的量化指标。基于对数万个不同企业风险和隐患案例分析的结果,发现风险向量、风险熵、风险特异度等几个参数的确定有助于对安全生产风险进行行业内和行业间的对比研究,从而为行业安全风险分类监控提供依据。

幽门螺杆菌Tipα对胃癌细胞顺铂敏感性的影响

目的基于磷酸肌醇-3激酶(PI3K)/蛋白激酶B(Akt)信号通路研究幽门螺杆菌肿瘤坏死因子-α诱导蛋白(Tipα)对胃癌细胞顺铂敏感性的作用机制。方法使用Tipα刺激胃癌SGC-7901细胞,采用CCK8检测细胞活性,流式细胞术检测细胞凋亡,Western blot检测PI3K/Akt信号通路相关蛋白——PI3K、p-PI3K、Akt、p-Akt表达水平,运用PI3K/Akt抑制剂——LY294002预处理细胞阻断PI3K/Akt信号通路,探讨PI3K/Akt信号通路活性与Tipα对胃癌细胞顺铂敏感性作用的关系。结果与顺铂组比较,Tipα联合顺铂组细胞活性、侵袭力、p-PI3K/PI3K比值、p-Ak/Akt比值均明显增加,细胞凋亡率明显降低,差异均有统计学意义(P<0.05);LY294002预处理可逆转Tipα对胃癌细胞顺铂敏感性的抑制作用。结论Tipα可通过激活PI3K/Akt信号通路抑制胃癌细胞的顺铂敏感性。