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   1707篇
  免费   81篇
  国内免费   157篇
耳鼻咽喉   2篇
儿科学   12篇
妇产科学   10篇
基础医学   256篇
口腔科学   5篇
临床医学   174篇
内科学   119篇
皮肤病学   4篇
神经病学   46篇
特种医学   16篇
外科学   94篇
综合类   509篇
预防医学   117篇
眼科学   9篇
药学   248篇
中国医学   275篇
肿瘤学   49篇
  2023年   27篇
  2022年   55篇
  2021年   101篇
  2020年   97篇
  2019年   84篇
  2018年   60篇
  2017年   33篇
  2016年   88篇
  2015年   46篇
  2014年   148篇
  2013年   144篇
  2012年   203篇
  2011年   199篇
  2010年   135篇
  2009年   103篇
  2008年   49篇
  2007年   81篇
  2006年   52篇
  2005年   27篇
  2004年   19篇
  2003年   14篇
  2002年   27篇
  2001年   22篇
  2000年   9篇
  1999年   20篇
  1998年   18篇
  1997年   16篇
  1996年   19篇
  1995年   9篇
  1994年   16篇
  1993年   8篇
  1992年   4篇
  1991年   5篇
  1990年   2篇
  1989年   3篇
  1988年   2篇
排序方式: 共有1945条查询结果,搜索用时 106 毫秒
31.
32.
33.
34.
Recombinant human growth hormone (rhGH) was lyophilized with various glass-forming stabilizers, employing cycles that incorporated various freezing and annealing procedures to manipulate glass formation kinetics, associated relaxation processes, and glass-specific surface areas (SSAs). The secondary structure in the cake was monitored by infrared and in reconstituted samples by circular dichroism. The rhGH concentrations on the surface of lyophilized powders were determined from electron spectroscopy for chemical analysis. Glass transition temperature (Tg), SSAs, and water contents were determined immediately after lyophilization. Lyophilized samples were incubated at 323 K for 16 weeks, and the resulting extents of rhGH aggregation, oxidation, and deamidation were determined after rehydration. Water contents and Tg were independent of lyophilization process parameters. Compared with samples lyophilized after rapid freezing, rhGH in samples that had been annealed in frozen solids prior to drying, or annealed in glassy solids after secondary drying retained more native-like protein secondary structure, had a smaller fraction of the protein on the surface of the cake, and exhibited lower levels of degradation during incubation. A simple kinetic model suggested that the differences in the extent of rhGH degradation during storage in the dried state between different formulations and processing methods could largely be ascribed to the associated levels of rhGH at the solid–air interface after lyophilization. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.  相似文献   
35.
Natural products have attained great importance as they are believed to be the new alternative medicines for conventional therapy. As numerous studies have proved the tremendous medicinal values of Hericium erinaceus, it is necessary to take into account its safety as well as its risk for the recipient. However, mushroom mycelium has an identity distinct from mushrooms, as two specific classes of compounds, hericenones and erinacines, can only be extracted from both the fruit body and the cultured mycelium, respectively. Therefore, this is the first report on the evaluation of the toxicity of H. erinaceus mycelium, enriched with 5 mg/g erinacine A, by a 28-day repeated oral administration study in Sprague–Dawley rats. Three doses of 1 (Low), 2 (Mid) and 3 (High) g/kg body weight/day were selected for the study while distilled water served as control. All animals survived to the end of the study. No abnormal changes were observed in clinical signs. No adverse or test article-related differences were found in urinalysis, haematology and serum biochemistry parameters, between the treatment and control groups. No gross pathological findings and histopathological differences were seen. Therefore, the no-observed-adverse-effect level of erinacine A-enriched H. erinaceus is greater than 3 g/kg body weight/day.  相似文献   
36.
37.
Pharmaceutical industries are imminent for the survival of any contemporary society as their products are valuable for the populace's health and wellness. However, the wastes of these industries have become a nuisance with severe implications on human health and ecosystem, especially in many developing countries where they are discharged indiscriminately into the environment, either untreated or poorly treated. Pharmaceutical Manufacturing Waste (PMW) effluents have been reported to possess a high BOD and COD, as well as recoverable APIs of various classes of pharmaceuticals. Moreover, antibiotic residues in these effluents are implicated in the progression and spread of antibiotic resistance in the aquatic and agroecosystem. Globally, the diverse activities of various pharmaceutical industries, owing to their diverse products, have resulted in difficulty in developing universal management and treatment protocols. Consequently, regulatory bodies/institutions find it challenging to monitor waste disposal practices of these industries adequately, primarily owing to their non-disclosure policies of intellectual properties. Hence, to a large extent, the onus for a sustainable society regarding PMWs lies in the decision and policies of these industries. Therefore, this review aims to foster informed policy-making decisions regarding waste management practices of pharmaceutical industries.  相似文献   
38.
During a study of ornithophilous viruses in China, a new densovirus (DNV) was isolated from the lung tissue of Parus major (PmDNV-JL). The complete genome of PmDNV-JL was cloned and sequenced. Five open reading frames (ORFs) were identified in the 5166 nt sequence, on the basis of deduced amino acids. It was further shown that this virus caused cytopathic effects (CPE) in Feline kidney cells. The NS1 gene sequence of PmDNV-JL shares 70–99% nucleotide sequence identity with isolates of the Blattella germanica densovirus (BgDNV) and BgDNV-like virus. Phylogenetic analysis indicated that the predicted amino acid sequences of capsid (VP) and non-structural domain (NS1) of PmDNV-JL clustered with the BgDNV and were similar to BgDNV-HB within the genus Densovirus.  相似文献   
39.
We report the observation of a patient who presented with post-transplant Kaposi's sarcoma after a delay of eight months with a dual cutaneous and palatal localisation. The reduction in immunosuppressive treatment and the introduction of Rapamune® allowed good clinical progress initially with regression of the skin lesions. He subsequently presented later a skin relapse with visceral localisation. Chemotherapy was conducted based on weekly paclitaxel infusions allowing partial remission and maintenance of renal graft function with good clinical tolerance.  相似文献   
40.
There are approximately 350 million hepatitis B virus (HBV) carriers worldwide. Chronic HBV infection increases the risk of liver cirrhosis and hepatocellular carcinoma. To date, two classes of antiviral drugs have been approved by the Food and Drug Administration for the treatment of hepatitis B, immunomodulators (interferon [IFN]‐α and pegylated‐interferon [PEG‐IFN]‐α) and nucleos(t)ide analogs (lamivudine, telbivudine, adefovir, tenofovir [TDF], and entecavir [ETV]). Of these, ETV, TDF, and PEG‐IFN‐α are the most effective and are currently recommended for anti‐HBV therapy. However, these therapies are less than optimal because of their low rate of viral DNA and surface antigen clearance; thus, there exists a significant unmet medical need for safe and efficacious new anti‐HBV drugs. Covering diverse chemical structures and mechanisms of action, non‐nucleos(t)ide compounds offer great promise in the search for new anti‐HBV drugs. This review summarizes the currently approved anti‐HBV drugs and highlights advances in the identification and characterization of novel small molecule HBV inhibitors. We discuss the sources, structures, anti‐HBV effects, mechanisms of action, and potential toxicities of these novel inhibitors.  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