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   120篇
  免费   7篇
  2023年   2篇
  2022年   3篇
  2021年   6篇
  2020年   2篇
  2019年   5篇
  2018年   5篇
  2017年   7篇
  2016年   4篇
  2015年   6篇
  2014年   11篇
  2013年   11篇
  2012年   11篇
  2011年   8篇
  2010年   6篇
  2009年   3篇
  2008年   5篇
  2007年   6篇
  2006年   5篇
  2005年   4篇
  2004年   4篇
  2003年   1篇
  2002年   5篇
  2001年   1篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1990年   1篇
  1987年   1篇
  1981年   1篇
排序方式: 共有127条查询结果,搜索用时 15 毫秒
101.
102.
Micropropagation protocol of Oriental Hybrid Lilium cv. Ravenna was developed using bulb scale segments (Basal and Tip) as explants. Surface sterilization of healthy bulb scales with carbendazim 200 ppm for 30 min, then 0.1 percent mercuric chloride for 10 min, then 70% ethyl alcohol for 30 s was superior to all other treatments in recording highest culture asepsis (77.08%) and higher explant survival (86.12%). Explant survival was higher in basal segments (88.54%) compared to tip segments (85.52%). Highest culture establishment was recorded in basal scale segments (68.26%) followed by tip scale segments (55.21%). MS medium augmented with 0.50 mgl−1 Naphthalene acetic acid and 2.0 mgl−1. 6-Benzylamino Purine recorded maximum culture establishment (76.17%), highest bulblet number/explant (5.52) with maximum length of shoots (2.20 cm) and number of leaves (3.39). This treatment combination of growth regulators resulted in highest shoot proliferation (83.33%) along with maximum shoot number (2.41explant−1), shoot length (2.35 cm) and leaf number (5.44) of micro shoots during proliferation stage. Rooting of explants was superior with Indole-3-butyric acid compared to Naphthalene acetic acid. Highest rooting of 92.71% along with maximum number of primary roots shoot−1 (12.06), maximum primary root length (3.17 cm) was documented in Murashige and Skoog medium added with Indole-3-butyric acid 1.50 mgl−1 with best ex vitro survival rate (98.96%) of rooted plantlets during primary hardening in perlite + vermiculite (1:1) mixture.  相似文献   
103.
Hydrogen sulfide as a gasotransmitter   总被引:1,自引:0,他引:1  
  相似文献   
104.
105.
Alcoholic liver disease (ALD) encompasses a variety of liver injuries with various underlying mechanisms but still no effective treatment. So we aimed to monitor the influence of simvastatin on alcohol-induced liver injury and elucidate the underlying mechanisms of its cytoprotective effect. Thirty male albino rats were randomly divided into five equal groups. Group 1 (control): received a standard diet; group 2: received simvastatin (10 mg kg−1 day −1) once a day orally for 8 weeks; group 3: received 20% ethanol (7.9 g kg −1 day −1) daily orally for 8 weeks; group 4: received 20% ethanol along with same simvastatin dose daily for 8 weeks; group 5: received 20% ethanol orally for 8 weeks then received the same simvastatin dose for the next 8 weeks. Serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured. Liver tissue malondialdehyde, reduced glutathione levels, and superoxide dismutase activity were estimated. B-cell lymphoma 2 and C/EBP homologous protein levels were evaluated by enzyme linked immunosorbent assay (ELISA). Light chain 3-II and peroxisome proliferation-activated receptor gamma messenger RNA expression was assessed by real-time polymerase chain reaction. Immunohistochemical staining was performed using anti-rat tumor necrosis factor-alpha antibody. Our results revealed that simvastatin treatment was able to ameliorate alcohol-induced liver damage; the improved biochemical data were confirmed by histopathological evaluation. Simvastatin being an autophagy inducer was able to prevent and reverse alcohol-induced liver changes via induction of autophagy, attenuation of oxidative stress, inflammation, and endoplasmic reticulum stress-induced apoptosis. Therefore, our findings suggest that treatment with simvastatin may be a useful approach in the management strategy of ALD.  相似文献   
106.
Toxic heavy metals in water, air and soil are global problems that are a growing threat to humanity. Heavy metals are widely distributed in the environment and some of them occur in food, water, air and tissues even in the absence of occupational exposure. The antioxidant and protective influences of vitamin E on a mixture of some heavy metals (Pb, Hg, Cd and Cu)-induced oxidative stress and renal and testicular injuries were evaluated in male mice. Exposure of mice to these heavy metals in drinking water for seven weeks resulted in statistical increases of plasma creatinine, urea and uric acid concentrations. The levels of glutathione (GSH) and superoxide dismutases (SOD) in kidney and testis tissues were significantly declined. Moreover, the histopathological evaluation of kidney and testis showed severe changes in mice treated with these heavy metals. Administration of vitamin E protected the kidney and testis of mice exposed to heavy metals as evidenced by appearance of normal histological structures, insignificant changes in the values of plasma creatinine, urea and uric acid, and the levels of kidney GSH and SOD, while the levels of testis GSH and SOD were notably decreased. These data suggest that the administration of vitamin E protects against heavy metals-induced renal and testicular oxidative stress and injuries.  相似文献   
107.
The CD24low/−CD44+EpCAM+ phenotype is associated with breast cancer initiating cells. To investigate if these putative breast cancer stem cell markers are regulated by estrogen receptor alpha (ERα) we have determined the expression levels of EpCAM, CD44 and CD24 in several well characterized breast cancer cell lines. The expression levels of the three adhesion proteins were quantitatively different in the cell lines but the composite CD24low/−CD44+EpCAM+ breast cancer stem cell phenotype was shown to exist as a small fraction, between 0.1% and 1.2%, in all breast cancer cell lines tested. Experimental silencing of ERα resulted in a reduced epithelial appearance and partial reduction of CD24 mRNA, while levels of CD44 and EpCAM were unaltered. Moreover, knockdown of ERα led to a change in the morphology of the cells similar to the epithelial to mesenchymal transition phenotype and was associated with decreased E-cadherin expression. Our findings offer new insights into the regulation of the breast cancer stem cell phenotype by ERα and suggest that treatments targeting the breast cancer stem cell adhesion molecules and the ERα pathway may be complementary.  相似文献   
108.
The regulation of telomere length (TL) is a complex process, requiring the telomerase enzyme complex and numerous regulatory proteins. Epigenetic regulation may also be important in telomere maintenance. Specifically, methylation at subtelomeres is associated with changes in TL in vitro and in mouse models. Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome characterized by exceedingly short telomeres and mutations in telomere biology genes. To understand the interaction between methylation and TL in humans, we measured LINE-1, pericentromeric (NBL2), and subtelomeric (D4Z4) methylation in peripheral blood DNA derived from 40 patients with DC and 51 mutation-negative relatives. Pearson's correlation coefficient and linear regression models were used to evaluate the relationship between age-standardized lymphocyte TL measured by flow FISH and % DNA methylation. No differences in % subtelomeric, LINE-1, or pericentromeric methylation between patients with DC and relatives were noted except for an increase in % subtelomeric methylation in DC patients with a telomerase-complex mutation (TERC, TERT, DKC1, or TCAB1) (63.0% in DC vs. 61.8% in relatives, P = 0.03). Positive correlations between TL and DNA methylation at LINE-1 (r = 0.39, P = 0.01) and subtelomeric (r = 0.32, P = 0.05) sites were present in patients with DC. The positive correlation between TL and % LINE-1 methylation was restricted to TINF2 mutations. In contrast, statistically nonsignificant inverse correlations between TL and % LINE-1 (r = -0.17), subtelomeric (r = -0.20) were present in unaffected relatives. This study suggests an interaction between TL and both subtelomeric and LINE-1 methylation, which may be altered based on mutation status of telomere biology genes.  相似文献   
109.
Medicinal plants have always been an important source of new alternative effective compounds for human therapy. Currently, there are many of scientific evidences indicate that the medicinal plants contain a lot of hypoglycemic chemical compounds. The purpose of the present study was to determine the influence of olive leaves extract on hepatorenal injury in diabetic male rats. Experimental diabetes was induced by streptozotocin (STZ). The levels of serum glucose, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transferase, total bilirubin, creatinine, blood urea nitrogen, uric acid and malondialdehyde were significantly increased, while the levels of serum superoxide dismutase, glutathione and catalase were statistically decreased in untreated diabetic rats. Moreover, the histopathological examination showed several alterations in the structure of liver and kidney in untreated diabetic rats. Treatments with low dose and high dose of olive leaves extract in diabetic rats showed remarkable reducing and protecting influences of physiological and histopathological alterations. Moreover, the highly treatment efficiency was noted in diabetic rats treated with high dose followed by low dose of olive leaves extract. Additionally, the results of this study proved that the antioxidant activities of olive leaves extract played a vital role against the hepatorenal injury induced by diabetes. Finally, this study indicates to the importance of the use of olive leaves extract as promising alternative and complementary therapeutic agent against diabetes and its complications.  相似文献   
110.
The discovery of the inducible isoform of cyclooxygenase enzyme (COX-2) spurred the search for anti-inflammatory agents devoid of the undesirable effects associated with classical NSAIDs. New chlorzoxazone ester prodrugs (68) of some acidic NSAIDs (13) were designed, synthesized and evaluated as mutual prodrugs with the aim of improving the therapeutic potency and retard the adverse effects of gastrointestinal origin. The structure of the synthesized mutual ester prodrugs (68) were confirmed by IR, 1H NMR, mass spectroscopy (MS) and their purity was ascertained by TLC and elemental analyses. In vitro chemical stability revealed that the synthesized ester prodrugs (68) are chemically stable in hydrochloric acid buffer pH 1.2 as a non-enzymatic simulated gastric fluid (SGF) and in phosphate buffer pH 7.4 as non-enzymatic simulated intestinal fluid (SIF). In 80% human plasma, the mutual prodrugs were found to be susceptible to enzymatic hydrolysis at relatively faster rate (t1/2  37 and 34 min for prodrugs 6 and 7, respectively). Mutual ester prodrugs (68) were evaluated for their anti-inflammatory and muscle relaxation activities. Scanning electromicrographs of the stomach showed that the ester prodrugs induced very little irritancy in the gastric mucosa of rats after oral administration for 4 days. In addition, docking of the mutual ester prodrugs (68) into COX-2 active site was conducted in order to predict the affinity and orientation of these prodrugs at the enzyme active site.  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