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   6732篇
  免费   423篇
  国内免费   27篇
耳鼻咽喉   83篇
儿科学   185篇
妇产科学   144篇
基础医学   908篇
口腔科学   557篇
临床医学   571篇
内科学   1419篇
皮肤病学   189篇
神经病学   448篇
特种医学   147篇
外科学   820篇
综合类   45篇
一般理论   1篇
预防医学   598篇
眼科学   177篇
药学   589篇
中国医学   54篇
肿瘤学   247篇
  2023年   64篇
  2022年   164篇
  2021年   271篇
  2020年   169篇
  2019年   203篇
  2018年   267篇
  2017年   158篇
  2016年   210篇
  2015年   251篇
  2014年   335篇
  2013年   360篇
  2012年   514篇
  2011年   607篇
  2010年   291篇
  2009年   207篇
  2008年   362篇
  2007年   410篇
  2006年   326篇
  2005年   322篇
  2004年   236篇
  2003年   186篇
  2002年   173篇
  2001年   124篇
  2000年   119篇
  1999年   111篇
  1998年   39篇
  1997年   30篇
  1996年   31篇
  1995年   27篇
  1994年   18篇
  1992年   58篇
  1991年   67篇
  1990年   35篇
  1989年   51篇
  1988年   42篇
  1987年   30篇
  1986年   34篇
  1985年   30篇
  1984年   23篇
  1983年   13篇
  1981年   11篇
  1980年   20篇
  1979年   23篇
  1978年   21篇
  1977年   15篇
  1976年   10篇
  1975年   12篇
  1974年   16篇
  1973年   9篇
  1969年   9篇
排序方式: 共有7182条查询结果,搜索用时 281 毫秒
91.
92.
Prostate cancer remains one of the leading causes of cancer death in men worldwide. In the past decade, several new treatments for advanced prostate cancer have been approved. With a wide variety of available drugs, including cytotoxic agents, androgen receptor axis-targeted therapies, and alpha-emitting radiation therapy, identifying their optimal sequencing remains a challenge. Progress in the understanding of the biology of prostate cancer has provided an opportunity for a more refined and personalized treatment selection process. With the advancement of molecular sequencing techniques, genomic precision through the identification of potential treatment targets and predictive biomarkers has been rapidly evolving. In this review, we discussed biomarker-driven treatments for advanced prostate cancer. First, we presented predictive biomarkers for established, global standard treatments for advanced diseases, such as chemotherapy and androgen receptor axis-targeted agents. We also discussed targeted agents with recent approval for special populations, such as poly ADP ribose polymerase (PARP) inhibitors in patients with metastatic castrate-resistant prostate cancer with homologous recombination repair-deficient tumors, pembrolizumab in patients with high levels of microsatellite instability or high tumor mutational burden, and prostate-specific membrane antigen (PSMA) directed radioligand theragnostic treatment for PSMA expressing tumors. Additionally, we discussed evolving treatments, such as cancer vaccines, chimeric antigen receptor T-cells (CAR-T), Bispecific T-cell engagers (BiTEs), other targeted agents such as AKT inhibitors, and various combination treatments. In summary, advances in molecular genetics have begun to propel personalized medicine forward in the management of advanced prostate cancer, allowing for a more precise, biomarker-driven treatment selection with the goal of improving overall efficacy.  相似文献   
93.
Chikungunya virus (CHIKV) is the causative agent of chikungunya fever, a disabling disease that can cause long-term severe arthritis. Since the last large CHIKV outbreak in 2015, the reemergence of the virus represents a serious public health concern. The morbidity associated with viral infection emphasizes the need for the development of specific anti-CHIKV drugs. Herein, we describe the development and characterization of a CHIKV reporter replicon cell line and its use in replicon-based screenings. We tested 960 compounds from MMV/DNDi Open Box libraries and identified four candidates with interesting antiviral activities, which were confirmed in viral infection assays employing CHIKV-nanoluc and BHK-21 cells. The most noteworthy compound identified was itraconazole (ITZ), an orally available, safe, and cheap antifungal, that showed high selectivity indexes of >312 and >294 in both replicon-based and viral infection assays, respectively. The antiviral activity of this molecule has been described against positive-sense single stranded RNA viruses (+ssRNA) and was related to cholesterol metabolism that could affect the formation of the replication organelles. Although its precise mechanism of action against CHIKV still needs to be elucidated, our results demonstrate that ITZ is a potent inhibitor of the viral replication that could be repurposed as a broad-spectrum antiviral.  相似文献   
94.
Summary The effect of pinacidil on the release of endogenous noradrenaline and dopamine from the sympathetic innervation of the rat vas deferens was examined. Amine release was evoked by electrical stimulation (1, 2, 5 and 10 Hz) or by depolarization with high potassium (75 mmol/l) in the medium. Dopamine and noradrenaline were measured by means of high pressure liquid chromatography with electrochemical detection.Pinacidil (1, 5, 10 and 50 mol/l) produced a concentration-dependent inhibition of the electrically stimulated (2 Hz) overflow of noradrenaline and dopamine. Only pinacidil 50 mol/l increased the spontaneous loss of dopamine and noradrenaline. The inhibitory effects of pinacidil (5 mol/l) on amine overflow were also observed at other frequencies of stimulation (1, 5 and 10 Hz). The magnitude of the inhibitory effect on noradrenaline release was approximately the same at all frequencies (63% to 56% reduction); for dopamine, the higher the frequency of stimulation, the greater the inhibitory effect of pinacidil (up to 73% reduction). When the preparations were continuously stimulated for 70 min at 2 Hz, pinacidil (5 mol/l) reduced the overflow of dopamine and noradrenaline during the first 40 or 30 min of stimulation only. The addition of phentolamine (1 mol/l) to the perifusion medium slightly reduced the inhibitory effect of pinacidil on amine overflow, but the inhibition by pinacidil remained statistically significant. Tetraethylammonium (10 mmol/l) completely abolished the inhibitory effect of pinacidil (10 mol/l). Pinacidil (5 mol/l) did not reduce the potassium-evoked release of the amines.The results demonstrate that pinacidil impairs transmitter release from the sympathetic innervation of the rat vas deferens, probably as a consequence of the opening of potassium channels. Send offprint request to P. Soares-da-Silva at the above adress  相似文献   
95.
The purpose of this study was to evaluate rat tissue antioxidant status after repeated administration of d-amphetamine. Three groups of four rats each were used: control, d-amphetamine sulphate dosed (s.c., 20 mg/kg per day), and pair-fed. After 14 days of d-amphetamine daily administration, superoxide dismutase (CuZnSOD and MnSOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GRed), glutathione-S-transferase (GST), glutathione (GSH), cysteine and thiobarbituric acid reactive substances (TBARS) were measured in liver, kidney, and heart. Various serum and urine parameters were also analysed. d-Amphetamine treatment induced an increase of liver GSH, as well as a decrease of cysteine and MnSOD levels in this organ. A small increase in serum transaminases was also observed in comparison to the pair-fed group. Hepatic levels of TBARS, GPx, GRed and CuZnSOD were found to be similar among the three groups of rats. d-Amphetamine treatment induced an increase of kidney GST, GRed and catalase levels, and an elevation of N-acetyl-β-d-glucosaminidase efflux to the urine, accompanied by a decrease in urinary creatinine, compared to the pair-fed group. In d-amphetamine treated animals, heart cysteine levels were significantly depleted when compared to the pair-fed group, but all three groups of rats were found to have similar heart antioxidant enzyme levels. These results indicate that repeated administration of d-amphetamine caused a certain degree of stress in liver and kidney, which was followed by adaptations of antioxidant defences. The mechanisms involved in d-amphetamine-induced toxicity may explain the different adaptations observed for the studied organs. Received: 19 October 1998 / Accepted: 11 January 1999  相似文献   
96.
Context Opioids have been used as the reference treatment on chronic pain. However, they are related to serious adverse effects which affect the patient compliance to treatment, as well as, his quality of life. Particulate formulations have been investigated as an alternative to improve opioid efficacy and safety. Objective Summarise the available studies concerning micro and nanoencapsulated opioid formulations discussing their biopharmaceutical characteristics, such as composition, size, in vitro release, pharmacokinetic and antinociceptive profile. Methods Papers available in 1995–2015 at Medline, Science Direct and Web of Science databases were collected and assessed. Searches were performed using varied combinations of the keywords of this work. Results Opioid-loaded particles showed prolonged drug release with maintenance of serum therapeutic concentrations and extended analgesia when compared with the free drugs. The side effects incidences were reduced or maintained the same. Conclusion Particulate formulations can significantly increase both potency and safety profiles of opioids.  相似文献   
97.
Summary The effect of perazine and the flavines FAD, FMN and riboflavine on the NAD-kinase of rat brain and the NAD-kinase of rat liver was studied.The flavine derivatives inhibited both enzymes. The inhibition mechanism was found to be non-competitive with rat liver NAD-kinase.Perazine, added simultaneously, restored the enzyme activity. The mechanism of interaction was elucidated by the use of the pA¯x-method and found to be competitive with rat liver NAD-kinase. The antagonism described occured with the rat brain enzyme too, but with the method used the mechanisms of inhibition and interaction could not be investigated.  相似文献   
98.
Although hydrogel extended-wear contact lenses (EWCLs) have been used extensively in the correction of aphakia in neonates, little is known about the effects of these lenses on infant corneas. Recent studies have demonstrated that long-term contact lenses can induce endothelial morphometric changes, including an increased coefficient of variation (CV) of mean endothelial cell area. Using wide-field specular microscopy, the authors studied 11 eyes of 10 patients, 1 to 3 years of age who, after lensectomy for congenital cataracts, wore EWCLs for the correction of aphakia. Except for two corneas in which increased pachometric readings and CV developed after repeated episodes of lens loss and inflammation, the EWCL were well tolerated and associated with few complications in this study.  相似文献   
99.
While surgical resection has remained the mainstay of treatment in early-stage renal cell carcinoma (RCC), therapeutic options in the advanced setting have remarkably expanded over the last 20 years. Tyrosine kinase inhibitors targeting the vascular endothelial growth factor receptor (VEGF-TKIs) and anti-programmed cell death 1 (PD-1)/anti-programmed death-ligand 1 (PD-L1)-based immune checkpoint inhibitors (ICIs) have become globally accepted options in the upfront metastatic setting, with different ICI-based combination strategies improving overall survival compared to single-agent Sunitinib. Although some patients benefit from long-term responses, most eventually develop disease progression. Ongoing efforts to better understand the biology of RCC and the different mechanisms of acquired resistance have led to the identification of promising therapeutic targets. Belzutifan, a novel agent targeting the angiogenic pathway involving hypoxia-inducible factors (HIFs), has already been approved for the treatment of early-stage tumors associated with VHL disease and represents a very promising therapy in advanced RCC. Other putative targets include epigenetic regulation enzymes, as well as several metabolites such as adenosine, glutaminase and tryptophan, which are critical players in cancer cell metabolism and in the tumor microenvironment. Different methods of immune regulation are also being investigated, including CAR-T cell therapy and modulation of the gut microbiome, in addition to novel agents targeting the interleukin-2 (IL-2) pathway. This review aims to highlight the emergent novel therapies for RCC and their respective completed and ongoing clinical trials.  相似文献   
100.
While ophthalmology as a surgical branch itself has evolved technologically with newer instruments, techniques and procedures; ophthalmic surgical training appears to have stagnated in terms of how it is delivered and how trainees’ learning and performance are assessed. This collaborative editorial attempts to identify the lacunae in ophthalmic residency training and highlight how technological tools such as surgical simulators can be incorporated into ophthalmic training even in limited-resource settings with good results.  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