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   838篇
  免费   72篇
  国内免费   1篇
  2024年   5篇
  2023年   8篇
  2022年   25篇
  2021年   36篇
  2020年   21篇
  2019年   33篇
  2018年   49篇
  2017年   33篇
  2016年   44篇
  2015年   52篇
  2014年   55篇
  2013年   71篇
  2012年   67篇
  2011年   68篇
  2010年   28篇
  2009年   44篇
  2008年   33篇
  2007年   31篇
  2006年   26篇
  2005年   18篇
  2004年   19篇
  2003年   19篇
  2002年   21篇
  2001年   8篇
  2000年   7篇
  1999年   6篇
  1998年   5篇
  1997年   2篇
  1996年   7篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   4篇
  1990年   3篇
  1986年   2篇
  1985年   2篇
  1984年   4篇
  1982年   4篇
  1981年   2篇
  1980年   5篇
  1979年   3篇
  1978年   3篇
  1977年   2篇
  1975年   2篇
  1973年   5篇
  1969年   4篇
  1967年   2篇
  1955年   1篇
  1948年   1篇
排序方式: 共有911条查询结果,搜索用时 46 毫秒
851.
Abstract

Introduction: Stomach ulcer is one of the most prevalent disorders worldwide. The study was aimed to isolate and characterize the major polymethoxylated flavonoids in Citrus sinensis peels petroleum ether extract and investigate its protective and curative effect on gastric ulcer.

Material and methods: Some spectral analyses were used for identification of the isolated compounds from the petroleum ether extract of Citrus sinensis peels. One oral dose (0.5?ml/100?g b.wt.) of absolute ethanol was orally given to rats after starvation for 24?h to induce gastric ulcer. To explore the protective and curative role of the plant extract, it was orally (250?mg/kg b.wt.) given for 1 week either before or post-ulcer induction. A reference drug, ranitidine (100?mg/kg b.wt.), was also evaluated. Stomach acidity, gastric volume, lesion counts, glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), succinate dehydrogenase (SDH), lactate dehydrogenase (LDH), acid phosphatase (AP), interlukin-10 (IL-10) and prostaglandin E2 (PGE2) were estimated. Stomach histopathological features were monitored.

Results: Nine polymethoxy flavonoids were identified from the extract. Treatment with C. sinensis peels extract recorded amelioration in all parameters.

Conclusion: Citrus sinensis petroleum ether peels extract had protective and curative effects against gastric ulcer. Therefore, the extract recorded anti-secretory, anti-ulcerative, anti-inflammatory, and antioxidant effects. Its healing action exceeded its protective role due to its richness in polymethoxylated flavonoids  相似文献   
852.
853.
Novel, selective, facile, and precise spectroscopic approaches were validated to determine nilotinib hydrochloride, a tyrosine kinase inhibitor used to treat patients with chronic myeloid leukemia. These approaches depend on the reaction of the tertiary amine group of nilotinib with erythrosine B in the Britton–Robinson buffer at pH 4. Method I, depends on measuring the absorbance of the formed complex at 551 nm. The absorbance concentration plot showed linearity over the concentration range of 1.0 to 9.0 μg/ml. Method II, involved the measurement of the quenching of the native fluorescence of erythrosine B by adding nilotinib in an acidic medium. The fluorescence quenching of erythrosine B was measured at 549 nm after excitation at 528 nm. This approach showed excellent linearity in the concentration range of 0.04 to 0.7 μg/ml. The limit of detection values for Method I and Method II were 0.225 and 0.008 μg/ml, respectively, while the limit of quantitation values for Method I and Method II were 0.68 and 0.026 μg/ml, respectively. To get the optimal conditions, factors that may affect the formation of the ion-pairing complex were thoroughly examined. The two approaches were carefully validated following the International Conference of Harmonization (ICH Q2R1) guidelines. Statistical assessment of the results achieved using the suggested and previously published comparison approaches showed no significant difference. The approaches were successful in determining nilotinib in a pharmaceutical dosage form as well as spiked human plasma samples. The eco-friendly properties of the methods were evaluated by three different tools.  相似文献   
854.
Biological Trace Element Research - The present study aims to evaluate the efficacy of selenium (Se) alone or combined with carbamazepine (CBZ) against the adverse effects induced by the...  相似文献   
855.
Summary Thirty-three strains of different species of rhizobia were seeded into medium 79 agar. Discs impregnated with 3, 0.3, 0.03 and 0.003%, corresponding to 10, 1, 1/10 and 1/100 the recommended rate of application, of fungicides TMTD, Rhizoctole, Phygon, Ceresan and Orthocide 75 were placed on the seeded agar. After 120 hrs, zones of inhibition were measured. The 3, 0.3 and 0.03% concentrations of the five fungicides were inhibitory to most rhizobia tested in different degrees. The 0.003% level of these fungicides while toxic to certain strains, was not so for others.Deceased August 6, 1968.  相似文献   
856.
857.
858.
859.
Effects of DNA on microtubule assembly   总被引:5,自引:0,他引:5  
  相似文献   
860.

Background  

Astrocytomas are cancers of the brain in which high levels of extracellular glutamate plays a critical role in tumor growth and resistance to conventional treatments. This is due for part to a decrease in the activity of the glutamate transporters, i.e. the Excitatory Amino Acid Transporters or EAATs, in relation to their nuclear mislocalization in astrocytoma cells. Although non-astrocytoma cancers express EAATs, the localization of EAATs and the handling of L-glutamate in that case have not been investigated.  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