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181.
目的:观察中药复方肾络宁对膜性肾病(MN)模型小鼠TNF-α和IL-10的影响。方法:实验Balb/c小鼠采用阳离子化牛血清白蛋白(C-BSA)诱导MN模型,分为模型组、肾络宁组,另设正常组,以肾络宁为治疗药物,于实验第0周、第3周、第6周末检测各组小鼠尿蛋白及血清TNF-α、IL-10的变化情况。结果:治疗6周后,模型组和肾络宁组小鼠均出现不同程度的尿蛋白排泄量增加,其中肾络宁组较模型组小鼠尿蛋白排泄量减少;与空白对照组比较,模型组、肾络宁组TNF-α表达均不同程度升高,IL-10表达均不同程度降低,其中肾络宁组改善优于模型组,差异均有统计学意义(P<0.05或P<0.01)。结论:肾络宁具有减少MN模型小鼠尿蛋白排泄的作用,其机制可能与调节TNF-α及IL-10的表达相关。 相似文献
182.
A large mid-channel sand bar in the macrotidal seaway of outer Asan Bay, Korea: 30 years of morphologic response to anthropogenic impacts 总被引:1,自引:1,他引:0
Tae Soo Chang Seong-Pil Kim Dong Geun Yoo Seungjong Lee Eunil Lee 《Geo-Marine Letters》2010,30(1):15-22
Over the past three decades, dike constructions along the shores and dredging activities for navigation purposes have caused
significant sedimentologic/morphologic modifications of a mid-channel bar situated in the tidal seaway of outer Asan Bay,
Korea, as shown by a comparison of two sediment datasets collected in the channel and over the bar in 1977 and 2008. In addition,
three hydrographic charts published in 1976, 1989, and 2006 were analyzed using GIS to estimate sand volume budgets and any
bar migration. The bar is currently about 15 km long and 2–5 km wide, with a relief of 15 m. It is elongated in the tidal
flow direction, but asymmetric in cross section. Chart analyses reveal a dramatic reduction in size and volume over the study
period. An approximate 19% net loss in total sediment volume was calculated between 1976 and 1989. Since then, a net gain
of about 7% has been estimated. The surface areas between selected depth contours reveal a similar pattern, i.e., substantial
shrinking until 1989, followed by slight expansion up to 2006. Comparing selected textural parameters (mean grain size, sorting)
of a 2008 sediment sampling campaign with those of a 1977 survey, it was found that mean grain sizes have decreased by as
much as 1-phi interval, and that the sediments have become more poorly sorted in the vicinity of the bar over the 30-year
study period, probably due to a sudden decrease in tidal energy flux after completion of the adjacent dikes. A particular
feature is the temporary response of the bar to man-made impacts, characterized by substantial shrinking along its southwestern
flank, and slight expansion along its northeastern flank. The observed changes in bar morphology can plausibly be explained
by a sudden decrease in sediment supply resulting from a reduction in tidal prism in the wake of diking. The bar initially
shrunk, but since 1989 has begun to gradually recover. To compensate the deficit, the bar has lowered its base level by scouring
troughs along both flanks. 相似文献
183.
分子鉴定方法研究大亚湾水体弧菌种类变化 总被引:2,自引:0,他引:2
借助分子鉴定方法监测大亚湾水体中弧菌Vibrio种类季节性动态的变化规律.通过增菌培养、菌株分离,在224份海水中共分离出弧菌368株,并用分子生物学辅助生化鉴定方法鉴定弧菌菌株.结果表明,在大亚湾海域水体中鉴定的弧菌种类有溶藻弧菌Vibrio alginolyticus、副溶血弧菌V.parahaemolyticus、哈氏弧菌V.harveyi和创伤弧菌V.vuinificus,没有检测到霍乱弧菌V.cholerae、拟态弧菌V.mimicus、河流弧菌V.fluvialis和霍利斯弧菌V.hollisae.溶藻弧菌和副溶血弧菌为优势菌群,分别占弧菌总数的27.99%和21.74%. 相似文献
184.
随着矿产勘查工作由浅部矿向深部隐伏矿、由易识别矿向难识别矿发展,找矿难度日益增大,地质专家越来越重视新理论、新方法、新技术的应用。深度学习作为人工智能的前沿领域/技术,对于实现矿产资源预测“智能化预测评价”具有得天独厚的优势。本文以陕西省镇安县西部钨钼矿集区单元素化探异常原始数据为基础,提出了基于深度学习的钨钼矿产评价方法。该方法以归一化地球化学数据作为模型训练数据,通过深度学习中深度自编码网络方法实现异常值提取进而识别重点成矿有利地段,实现矿产资源找矿远景区定性预测。研究结果表明,在对957条单元素化探异常原始数据分类且做好模型标签后,整个过程在计算机的“黑盒子”中自动完成学习和预测,相较于传统预测研究方法,本文方法具有自动化程度高和客观性强的特征。此外,本文利用已知矿点构建训练数据集,采用随机森林方法对预测区进行矿产资源找矿靶区预测圈定,为进一步缩小找矿靶区范围提供科学依据。 相似文献
185.
The paper presents a numerical method for calculating the particle trajectories of nonlinear gravity waves in deep water. Particle trajectories, mass-transport velocity and Lagrangian wave period can be accurately determined by the proposed method. The high success rate of the proposed method is examined by comparing the present results with those of (a) Longuet-Higgins, M.S., 1986, 1987. Eulerian and Lagrangian aspects of surface waves. Journal of Fluid Mechanics 173, 683-707 and (b) Lagrangian moments and mass transport in Stokes waves. Journal of Fluid Mechanics 179, 547-555. It is shown that the dimensionless mass-transport velocity can exceed 10% for large waves, and the Lagrangian wave period is much larger than the Eulerian wave period for large waves. 相似文献
186.
Po-Hung Yeh Kuang-An Chang John Henriksen Billy Edge Peter Chang Andrew Silver Abel Vargas 《Ocean Engineering》2009,36(3-4):248-255
This study investigates the topographic deformation due to the erosion of a sand bed impinged by a moving submerged turbulent round jet in a large-scale laboratory. The test conditions represent the case of discharges beneath a vessel while operating in water with a limited clearance such as a shallow navigation channel. The jet moves horizontally and discharges water vertically downward towards the bed. The distance between the jet nozzle and the bed equals six times the jet diameter so the jet flow is in the potential core region. The speed of the jet horizontal motion was varied to examine its effect on the scour profile. The characteristic lengths of the scour profile in the asymptotic state were determined by modifying the empirical formulas in Aderibigbe and Rajaratnam [1996. Erosion of loose beds by submerged circular impinging vertical turbulent jets. Journal of Hydraulic Research 34(1), 19–33]. The maximum scour depth, the scour hole radius, and the ridge height were found to be a function of the ratio of the jet exit to jet translation velocities and were modeled using a hyperbolic function. Empirical equations describing the scour profile were developed and the scour profile was found to be self-similar when normalized by appropriate length scales. 相似文献
187.
The run-up flow and related pressure of solitary waves breaking on a 1:20 plane beach were investigated experimentally in a super tank (300 m × 5 m × 5.2 m). Swash flow measurements of flow velocities are compared with an existing analytical solution. By incorporating an analytical solution, the hydrodynamic pressure for a quasi-steady flow state is determined and compared with laboratory data. Concerning the evident extra pressure exerted by the impact of swash flow, an empirical drag coefficient for a circular plate is also suggested in the present study. 相似文献
188.
Qingchun Wen Xiuzhen Li Hongshi He Yuanman Hu Xin Chen Yu Chang Wei Wang Rencang Bu 《中国地理科学(英文版)》2014,24(1):50-59
Traditionally,patch-based analysis at the landscape scale fragmentation has been used in the study of landscape ecology while the study of boundary and node has not been considered as much detail until recently.This study investigated the possibility of applying boundary-and node-based methods in landscape pattern analysis to the upper reaches of the Minjiang River in the southwestern China.Boundary-based and node-based landscape indices were selected to be used in analyzing changes in landscape patterns,and the results were compared with analysis using traditional pattern indices.We compared the responses of patch-area-based,boundary-length-based and node-number-based indices,and concluded that boundary-based and node-based indices are more sensitive to disturbance than patch-based indices with various patterns,and node-based indices are even more sensitive than boundary-based ones.Thus,the results suggest that boundary-based and node-based pattern analysis methods provide helpful supplementary information to traditional patch-based pattern analysis methods.The results about pattern dynamics of landscapes in the upper reaches of the Minjiang River based on boundaries and nodes showed that with human disturbance,the dominance of forest landscape was weakened by other landscape types; thus the landscape pattern of the study area became more homogeneous and the boundary network became more complex.These changes further augmented disturbance interfaces in the landscape and increased the possibilities of further landscape fragmentation. 相似文献
189.
Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when study-ing the dark matter particles and the acceleration mechanism of cosmic rays. An imaging calorimeter,BETS (Balloon-borne Electron Telescope with Scintillator fiber),has been de-veloped for this purpose. Using pattern analysis of the shower development,the electrons can be selected from those primary cosmic ray proton events with flux heights one-tenth that of the electrons. The Monte-Carlo simulation is indispensable for the instrument design,the sig-nal trigger and the data analysis. We present different shower simulation codes and compare the simulation results with the beam test and the flight data of BETS. We conclude that the code FLUKA2002 gives the most consistent results with the experimental data. 相似文献
190.
Rui-Zhi Yang Jin Chang Jian Wu Purple Mountain Observatory Chinese Academy of Sciences Nanjing China 《中国天文和天体物理学报》2010,10(1)
Results from PAMELA and ATIC indicate that the Kaluza-Klein type dark matter particles could be the annihilation source of the observed excess of electrons and positrons.Assuming the existence of a nearby black hole with 10000–100000 solar masses and a point source boost algorithm,we apply the standard propagation model and find that the results fit the data well. 相似文献