全文获取类型
收费全文 | 42460篇 |
免费 | 3878篇 |
国内免费 | 2290篇 |
专业分类
耳鼻咽喉 | 618篇 |
儿科学 | 565篇 |
妇产科学 | 923篇 |
基础医学 | 4834篇 |
口腔科学 | 701篇 |
临床医学 | 5019篇 |
内科学 | 7324篇 |
皮肤病学 | 871篇 |
神经病学 | 2173篇 |
特种医学 | 1419篇 |
外国民族医学 | 18篇 |
外科学 | 4488篇 |
综合类 | 5652篇 |
现状与发展 | 5篇 |
一般理论 | 8篇 |
预防医学 | 2942篇 |
眼科学 | 920篇 |
药学 | 4404篇 |
37篇 | |
中国医学 | 2077篇 |
肿瘤学 | 3630篇 |
出版年
2024年 | 128篇 |
2023年 | 622篇 |
2022年 | 1529篇 |
2021年 | 1982篇 |
2020年 | 1418篇 |
2019年 | 1416篇 |
2018年 | 1515篇 |
2017年 | 1368篇 |
2016年 | 1276篇 |
2015年 | 1860篇 |
2014年 | 2307篇 |
2013年 | 2291篇 |
2012年 | 3174篇 |
2011年 | 3368篇 |
2010年 | 2160篇 |
2009年 | 1744篇 |
2008年 | 2346篇 |
2007年 | 2241篇 |
2006年 | 2203篇 |
2005年 | 2137篇 |
2004年 | 1550篇 |
2003年 | 1514篇 |
2002年 | 1269篇 |
2001年 | 1027篇 |
2000年 | 918篇 |
1999年 | 843篇 |
1998年 | 517篇 |
1997年 | 464篇 |
1996年 | 365篇 |
1995年 | 343篇 |
1994年 | 307篇 |
1993年 | 209篇 |
1992年 | 352篇 |
1991年 | 304篇 |
1990年 | 245篇 |
1989年 | 196篇 |
1988年 | 201篇 |
1987年 | 176篇 |
1986年 | 134篇 |
1985年 | 126篇 |
1984年 | 88篇 |
1983年 | 50篇 |
1982年 | 26篇 |
1981年 | 37篇 |
1980年 | 21篇 |
1979年 | 35篇 |
1978年 | 25篇 |
1977年 | 21篇 |
1975年 | 19篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Ludefu Su Yu Liu Yanhong Tang Mingmin Zhou Liang Xiong Congxin Huang 《International journal of clinical and experimental pathology》2021,14(4):408
Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive. 相似文献
2.
Her-Shyong Shiah Nai-Jung Chiang Chia-Chi Lin Chia-Jui Yen Hui-Jen Tsai Shang-Yin Wu Wu-Chou Su Kwang-Yu Chang Ching-Chiung Wang Jang-Yang Chang Li-Tzong Chen 《The oncologist》2021,26(4):e567-e579
Lessons Learned
- SCB01A is a novel microtubule inhibitor with vascular disrupting activity.
- This first‐in‐human study demonstrated SCB01A safety, pharmacokinetics, and preliminary antitumor activity.
- SCB01A is safe and well tolerated in patients with advanced solid malignancies with manageable neurotoxicity.
3.
Hyun Jong Choi Jong Ho Moon Yun Nah Lee Hyun Su Kim Ji Su Ha Tae Hoon Lee Sang‐Woo Cha Young Deok Cho Sang‐Heum Park 《Digestive endoscopy》2015,27(7):772-775
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS. 相似文献
4.
5.
Yinlei
Wen Huaguang Zhang Hanguang Su He Ren 《Optimal control applications & methods.》2020,41(4):1233-1250
In this article, a model-free off-policy reinforcement learning algorithm is applied to address the optimal tracking problem based on multiplayer non-zero-sum games for discrete-time linear systems. In contrast to the traditional method and the policy iteration method for solving the optimal tracking problems, the proposed algorithm operates with the system data rather than the knowledge of the system dynamics. For performing the proposed algorithm, an auxiliary augmented system is constructed via assembling the original system and the reference trajectory while a discount factor is introduced into the performance indexes. It is analyzed that the solutions of the proposed algorithm converge to the Nash equilibrium and the result is not influenced by the probing noise. Two simulations are presented to verify the feasibility and effectiveness of the proposed algorithm. 相似文献
6.
7.
8.
Jianhui Su Chaoyang Ma Chengxiang Liu Chuanzhong Gao Rongjing Nie 《International journal of food sciences and nutrition》2016,67(1):20-28
This study investigated the hypocholesterolaemic effects of bitter melon aqueous extracts (BMAE) in vitro, the inhibitory effects of BMAE on pancreatic cholesterol esterase (CEase) and incorporation of cholesterol into micelles were investigated. BMAE decreased the in vitro micellar solubility of cholesterol in a dose-dependent manner. The conformation of CEase was investigated by means of circular dichroism (CD) and fluorescence. The result revealed the decrease of α-helix contents, increase of β-sheet and exposure of aromatic amino acid residuals. The incorporation of cholesterol into micelles was inhibited by BMAE. A complex was observed by transmission electron microscopy (TEM), which indicated interaction between cholesterol and BMAE. The result revealed that BMAE can play a role in decreased intestinal cholesterol absorption via inhibition of CEase, and of micelle formation. 相似文献
9.
Jeffrey Buenaflor Parker Sommerville Hang Qian Christine Luscombe 《Macromolecular chemistry and physics.》2020,221(2)
A comparative study involving bimetallic nickel catalysts designed from disubstituted N,N,N′,N′‐tetra(diphenylphosphanylmethyl)benzene diamine bridging ligands is reported. Catalyst behavior is explored in the Kumada catalyst‐transfer polymerization (KCTP) using poly(3‐hexylthiophene) (P3HT) as the model system. The success of a controlled polymerization is monitored by analyzing monomer conversion, degree of polymerization, end‐group identity, and molecular weight distribution. The characterization of P3HT obtained from KCTP initiated with the bimetallic catalysts shows chain‐growth behavior; however, the presence of Br/Br end‐groups and broader molecular weight distribution reveals a reduced controlled polymerization compared to the commonly employed Ni(dppp)Cl2. The observed increase in intermolecular chain transfer and termination processes in KCTP initiation with the bimetallic catalysts can be attributed to a weaker Ni(0)‐π‐aryl complex interaction, which is caused by increased steric crowding of the coordination sphere. 相似文献
10.