全文获取类型
收费全文 | 4597篇 |
免费 | 286篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 245篇 |
妇产科学 | 62篇 |
基础医学 | 523篇 |
口腔科学 | 171篇 |
临床医学 | 386篇 |
内科学 | 791篇 |
皮肤病学 | 66篇 |
神经病学 | 499篇 |
特种医学 | 186篇 |
外科学 | 750篇 |
综合类 | 134篇 |
一般理论 | 4篇 |
预防医学 | 255篇 |
眼科学 | 87篇 |
药学 | 334篇 |
中国医学 | 18篇 |
肿瘤学 | 335篇 |
出版年
2023年 | 39篇 |
2022年 | 57篇 |
2021年 | 167篇 |
2020年 | 77篇 |
2019年 | 138篇 |
2018年 | 160篇 |
2017年 | 112篇 |
2016年 | 124篇 |
2015年 | 130篇 |
2014年 | 193篇 |
2013年 | 226篇 |
2012年 | 338篇 |
2011年 | 335篇 |
2010年 | 209篇 |
2009年 | 177篇 |
2008年 | 318篇 |
2007年 | 285篇 |
2006年 | 227篇 |
2005年 | 247篇 |
2004年 | 215篇 |
2003年 | 181篇 |
2002年 | 150篇 |
2001年 | 83篇 |
2000年 | 91篇 |
1999年 | 75篇 |
1998年 | 34篇 |
1997年 | 31篇 |
1996年 | 24篇 |
1995年 | 23篇 |
1994年 | 12篇 |
1993年 | 18篇 |
1992年 | 26篇 |
1991年 | 48篇 |
1990年 | 37篇 |
1989年 | 36篇 |
1988年 | 25篇 |
1987年 | 34篇 |
1986年 | 28篇 |
1985年 | 20篇 |
1984年 | 19篇 |
1983年 | 18篇 |
1982年 | 7篇 |
1981年 | 14篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1967年 | 5篇 |
1917年 | 4篇 |
排序方式: 共有4898条查询结果,搜索用时 109 毫秒
1.
N. S. Hari Narayana Moorthy Sergio F. Sousa Maria J. Ramos Pedro A. Fernandes 《Medicinal chemistry research》2016,25(7):1340-1357
Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets. 相似文献
2.
3.
4.
5.
Pankaj Hari Anand Srivastava Arun Kumar Gupta Rajendra N. Srivastava 《Pediatric nephrology (Berlin, Germany)》1997,11(4):497-498
Acute renal failure (ARF) developed in a 7-week-old infant due to bilateral candidal bezoars (fungal balls) causing obstruction
at the pelviureteric junction. The baby was born at term with an appropriate birthweight, and had been treated with broad-spectrum
antibiotics for respiratory distress and septicemia during the 1st week of life. Recovery from ARF followed renal decompression
with bilateral nephrostomy tube placement and parenteral administration of amphotericin B and 5-flucytosine.
Received August 21, 1996; received in revised form and accepted January 3, 1997 相似文献
6.
Sarala Rajajee Malathi Sathyasekaran Janani Shankar Latha Dhathathri Anandnathan 《Indian journal of pediatrics》2002,69(10):821-822
A 5-year-old boy presented with history of failure to thrive from infancy. There was a history of one sibling death due to
similar problems and history of severe abortions in the mother. Routine examination of peripheral smear revealed more than
50% acanthocytes. Based on this tests were streamlined to doing lipid profile and Lipo protein electrophoresis which revealed
hypolipidemia and absent Β hypo protein band. Jejuna) mucosal biopsy confirmed the diagnosis of A Beta Lipo proteinemia which
revealed lipid laden enterocytes. This case illustrates the importance of simple tests like peripheral smear examination in
streamlining further tests in the diagnosis of major diseases. 相似文献
7.
We studied the relationship between arterial carbon dioxide tension (PaCO2) and fresh gas flow (FGF) during use of the Bain breathing circuit for Caesarean section anaesthesia. Thirty-one patients undergoing Caesarean section were anaesthetised using the Bain circuit with intermittent positive pressure ventilation. The PaCO2 were measured at FGF of 70 ml X kg-1 X min-1, 80 ml X kg-1 X min-1, and 100 ml X kg-1 X min-1. The FGF requirement to maintain a given PaCO2 during Caesarean section anaesthesia is the same as the requirements for nonpregnant subjects, despite the increase in carbon dioxide production associated with pregnancy. This is probably because the total FGF determined by body weight and given during Caesarean section anaesthesia is 15-20 per cent higher than nonpregnant levels, due to the weight gain associated with pregnancy. A FGF of 100 ml X kg-1 of pregnant weight/min maintains PaCO2 of 4.44 kPa predelivery, which is in the desirable range of PaCO2 during Caesarean section. 相似文献
8.
9.
Global gene profiling reveals a downregulation of BMP gene expression in experimental atrophic nonunions compared to standard healing fractures. 总被引:1,自引:0,他引:1
Nonunion is a challenging problem that may occur following certain bone fractures. However, there has been little investigation of the molecular basis of nonunions. Bone morphogenetic proteins (BMPs) play a significant role in osteogenesis. However, little is known about the expression patterns of BMPs in abnormal bone healing that results in nonunion formation. These facts prompted us to investigate and compare the gene expression patterns of BMPs and their antagonists in standard healing fractures and nonunions using rat experimental models. Standard closed healing fractures and experimental atrophic nonunions produced by periosteal cauterization at the fracture site were created in rat femurs. At postfracture days 3, 7, 10, 14, 21, and 28, total RNA was extracted from the callus of standard healing fracture and fibrous tissue of nonunion (n=4 per each time point and each group). Gene expression of BMPs, BMP antagonists, and other regulatory molecules were studied by methods including Genechip microarray and real-time quantitative RT-PCR. Gene expression of BMP-2, 3, 3B, 4, 6, 7, GDF-5, 7, and BMP antagonists noggin, drm, screlostin, and BAMBI were significantly lower in nonunions compared to standard healing fractures at several time points. Downregulation in expression of osteogenic BMPs may account for the nonunions of fracture. The balance between BMPs and their endogenous antagonists is critical for optimal fracture healing. 相似文献
10.