首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   301篇
  免费   19篇
  320篇
  2024年   1篇
  2023年   4篇
  2022年   4篇
  2021年   4篇
  2020年   8篇
  2019年   7篇
  2018年   10篇
  2017年   13篇
  2016年   17篇
  2015年   9篇
  2014年   24篇
  2013年   23篇
  2012年   17篇
  2011年   30篇
  2010年   16篇
  2009年   12篇
  2008年   15篇
  2007年   14篇
  2006年   11篇
  2005年   19篇
  2004年   11篇
  2003年   8篇
  2002年   6篇
  2001年   7篇
  2000年   11篇
  1999年   4篇
  1998年   8篇
  1997年   1篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1981年   1篇
  1978年   2篇
排序方式: 共有320条查询结果,搜索用时 15 毫秒
1.
This study aimed to investigate the protective effects of arbutin (ARB) against brain injury induced in rats with potassium bromate (KBrO3). The rats were divided into four groups as Group 1: Control (0.9% NaCl ml/kg/day p.), Group 2: KBrO3 (100 mg/kg (gavage), Group 3: ARB (50 mg/kg/day p.), and Group 4: KBrO3 + ARB (100 mg/kg (gavage) + 50 mg/kg/day p.). At the end of the fifth day of the study, the rats in all groups were killed, and their brain tissues were collected. In the collected brain tissues, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels were measured, and routine histopathological examinations were made. The MDA levels in the group that was exposed to KBrO3 were significantly higher than those in the control group (p ˂ 0.001). In comparison to the KBrO3 group, the MDA levels in the KBrO3 + ARB group were significantly lower (p ˂ 0.001). It was observed that SOD and CAT enzyme activity levels were significantly lower in the KBrO3 group compared to the control group (p ˂ 0.001), while these levels were significantly higher in the KBrO3 + ARB group than in the KBrO3 group (p ˂ 0.001). Additionally, the group that was subjected to KBrO3 toxicity, as well as ARB administration, had much lower levels of histopathologic signs than the group that was subjected to KBrO3 toxicity only. Consequently, it was found that KBrO3 exposure led to injury in the brain tissues of the rats, and using ARB was effective in preventing this injury.  相似文献   
2.
Molecular Biology Reports - Glioma is the most common type of brain tumors and isocitrate dehydrogenase (IDH1) gene is the most prominent molecular marker about the disease prognosis, response to...  相似文献   
3.
Thesystematics of the genus Gobio, especially of the populations on the southern Black Sea coast, seems to be still far from being resolved. Seven species were rec-orded from the northern Black Sea coast while three species were recognized from the southern Black Sea coast. We examined in total 43 specimens from K?z?l?rmak River (southern Black Sea basin), 80 specimens from Çoruh River (the Western Cau-casus of the Black Sea basin), 14 specimens from Rioni River (the Western Caucasus of the Black Sea basin), and 6 specimens from Kherota and Shakhe Rivers (the Western Caucasus of the Black Sea basin). Based on an analysis of 32 metric and 5 meristic data as well as the number of vertebrae, we concluded that the K?z?l?rmak and Coruh populations are two distinct, unnamed species, and we describe them here as Gobio kizilirmakensis from the K?z?l?rmak River and G. artvinicus from the Çoruh River.

http://www.zoobank.org/urn:urn:lsid:zoobank.org:pub:1ED54FB1-588F-4412-B376-4BE4E4516EB1  相似文献   
4.
This study is aimed at investigating the inhibitory effect of cadmium ion on glutathione reductase activity of rabbit brain and liver and the relationship of this effect with dietary selenium. For this purpose, one group of New Zealand rabbits were fed a selenium-deficient diet, another group was fed a selenium-rich diet, and the control group was fed a normal diet. The brain and liver tissues of these groups were investigated for the in vitro inhibitory effects of Cd2+ on glutathione reductase activity. For liver, the percentage inhibition of glutathione reductase by 40 nmol/mg protein of Cd2+ was similar for selenium-deficient and control groups, but significantly lower in the selenium-rich group. For brain tissues, there was no difference with respect to cadmium inhibition of glutathione reductase in all three groups.  相似文献   
5.
Numerical prediction of non-Newtonian blood flow in a 3D abdominal aortic aneurysm bifurcating model is carried out. The non-Newtonian Carreau model is used to characterise the shear thinning behaviour of the human blood. A physical inlet velocity waveform incorporating a radial velocity distribution reasonably representative of a practical case configuration is employed. Case studies subject to both equal and unequal outlet pressures at iliac bifurcations are presented to display convincingly the downstream pressure influences on the flow behaviour within the aneurysm. Simulations indicate that the non-Newtonian aspects of the blood cannot at all be neglected or given a cursory treatment. The wall shear stress (WSS) is found to change significantly at both the proximal and distal ends of the aneurysm. At the peak systole, the WSS is peak around the bifurcation point, whereas the WSS becomes zero in the bifurcation point. Differential downstream pressure fields display significant effects regarding the flow evolution in the iliac arteries, whereas little or no effects are observed directly on the flow details in the aneurysm.  相似文献   
6.
We hypothesized that solid tumors rarely occur in patients with hydatid disease. We obtained the serum of 14 patients diagnosed with hydatid disease, the serum of 10 patients who did not have a history of hydatid disease, and the hydatid cyst fluid from six patients. These sera and fluid samples were added at different concentrations to NCI-H209/An1 human lung small cell carcinoma cells and L929 mouse fibroblasts as a control group. Sera of patients with hydatid diseases had cytotoxic effects on NCI-H209/An1 cells, but they did not have cytotoxic effects on fibroblast cells. Sera from healthy subjects did not have a cytotoxic effect on the tumor cell line or control fibroblasts. Cyst fluid, also, did not have toxic effects on the NCI-H209/An1 cell line, but was toxic to fibroblasts up to a 1:32 dilution. Sera from patients with hydatid disease had cytotoxic effects on human small cell lung cancer cells in vitro.  相似文献   
7.
8.
9.
10.
This study tested the spatial variations in the digestive/intestine tract length of Capoeta banarescui, with regard to their diets in different habitats. Highly varied diets observed in a previous study within the same river system posed the question whether this flexibility is reflected in the digestive tract and intestine length of the species in the Ye?il?rmak River, Turkey. Totals of 382 specimens (standard length 4.6–19.1 cm) were captured by electro‐fishing along the river in September 2012 at 11 locations spanning elevations from 34 to 992 m. The stomach, intestine and total digestive tract lengths were measured, and stomach contents analysed from 196 specimens. For statistical analyses, the stomach, intestine and total digestive tract length were expressed as percentages of total weight and standard length. The data provided evidence that the digestive tract and intestine lengths varied significantly among locations in association with the diet. Fish having dominantly carnivorous diets (e.g. chironomid larvae/invertebrates) in two locations had significantly shorter intestines and digestive tracts than those with diets dominated by benthic algae and other plants. The data indicated that C. banarescui showed broad flexibility in their feeding habits. Feeding heavily on plant materials might lead to the development of longer digestive tracts, increasing the active surface area for digestion; alternatively, there may be less invested in development of the digestive tract when feeding primarily on carnivorous diets where the respective digestive enzymes are readily available. The data suggest that phenotypic plasticity in the digestive tract length of C. banarescui is associated more with the abundant protein‐rich carnivorous food sources in the studied habitats. Whether this digestive tract plasticity has a genetic background remains to be verified in future studies.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号