全文获取类型
收费全文 | 20797篇 |
免费 | 2030篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 228篇 |
儿科学 | 548篇 |
妇产科学 | 441篇 |
基础医学 | 2617篇 |
口腔科学 | 605篇 |
临床医学 | 2172篇 |
内科学 | 4461篇 |
皮肤病学 | 290篇 |
神经病学 | 1877篇 |
特种医学 | 712篇 |
外国民族医学 | 1篇 |
外科学 | 3189篇 |
综合类 | 454篇 |
一般理论 | 47篇 |
预防医学 | 2086篇 |
眼科学 | 612篇 |
药学 | 1344篇 |
中国医学 | 34篇 |
肿瘤学 | 1144篇 |
出版年
2021年 | 302篇 |
2020年 | 217篇 |
2019年 | 367篇 |
2018年 | 420篇 |
2017年 | 343篇 |
2016年 | 318篇 |
2015年 | 366篇 |
2014年 | 454篇 |
2013年 | 728篇 |
2012年 | 966篇 |
2011年 | 1030篇 |
2010年 | 641篇 |
2009年 | 541篇 |
2008年 | 953篇 |
2007年 | 974篇 |
2006年 | 951篇 |
2005年 | 930篇 |
2004年 | 901篇 |
2003年 | 926篇 |
2002年 | 789篇 |
2001年 | 560篇 |
2000年 | 574篇 |
1999年 | 529篇 |
1998年 | 231篇 |
1997年 | 221篇 |
1996年 | 173篇 |
1995年 | 185篇 |
1994年 | 161篇 |
1993年 | 167篇 |
1992年 | 410篇 |
1991年 | 384篇 |
1990年 | 388篇 |
1989年 | 364篇 |
1988年 | 343篇 |
1987年 | 311篇 |
1986年 | 360篇 |
1985年 | 303篇 |
1984年 | 264篇 |
1983年 | 227篇 |
1982年 | 168篇 |
1980年 | 165篇 |
1979年 | 254篇 |
1978年 | 218篇 |
1977年 | 195篇 |
1976年 | 159篇 |
1975年 | 184篇 |
1974年 | 212篇 |
1973年 | 205篇 |
1972年 | 173篇 |
1971年 | 169篇 |
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
1.
2.
E. Niclas Jonsson Rujia Xie Scott F. Marshall Rosalin H. Arends 《British journal of clinical pharmacology》2016,81(4):688-699
AimsThe aims were to 1) develop the pharmacokinetics model to describe and predict observed tanezumab concentrations over time, 2) test possible covariate parameter relationships that could influence clearance and distribution and 3) assess the impact of fixed dosing vs. a dosing regimen adjusted by body weight.MethodsIndividual concentration–time data were determined from 1608 patients in four phase 3 studies conducted to assess efficacy and safety of intravenous tanezumab. Patients received two or three intravenous doses (2.5, 5 or 10 mg) every 8 weeks. Blood samples for assessment of tanezumab PK were collected at baseline, 1 h post‐dose and at weeks 4, 8, 16 and 24 (or early termination) in all studies. Blood samples were collected at week 32 in two studies. Plasma samples were analyzed using a sensitive, specific, validated enzyme‐linked immunosorbent assay.ResultsA two compartment model with parallel linear and non‐linear elimination processes adequately described the data. Population estimates for clearance (CL), central volume (V
1), peripheral volume (V
2), inter‐compartmental clearance, maximum elimination capacity (VM) and concentration at half‐maximum elimination capacity were 0.135 l day–1, 2.71 l, 1.98 l, 0.371 l day–1, 8.03 μg day–1 and 27.7 ng ml–1, respectively. Inter‐individual variability (IIV) was included on CL, V
1, V
2 and VM. A mixture model accounted for the distribution of residual error. While gender, dose and creatinine clearance were significant covariates, only body weight as a covariate of CL, V
1 and V
2 significantly reduced IIV.ConclusionsThe small increase in variability associated with fixed dosing is consistent with other monoclonal antibodies and does not change risk : benefit. 相似文献
3.
4.
5.
Fabian M. Laage Gaupp Nadia Solomon Ivan Rukundo Azza A. Naif Erick M. Mbuguje Anish Gonchigar Minzhi Xing John D. Prologo Douglas D. Silin Frank J. Minja 《Journal of vascular and interventional radiology : JVIR》2019,30(12):2036-2040
Despite a population of nearly 60 million, there is currently not a single interventional radiologist in Tanzania. Based on an Interventional Radiology (IR) Readiness Assessment, the key obstacles to establishing IR in Tanzania are the lack of training opportunities and limited availability of disposable equipment. An IR training program was designed and initiated, which relies on US-based volunteer teams of IR physicians, nurses, and technologists to locally train radiology residents, nurses, and technologists. Preliminary results support this strategy for addressing the lack of training opportunities and provide a model for introducing IR to other resource-limited settings. 相似文献
6.
Mahwash Kassi Venkateshwar Polsani Robert C. Schutt Solomon Wong Faisal Nabi Michael J. Reardon Dipan J. Shah 《The Journal of thoracic and cardiovascular surgery》2019,157(5):1912-1922.e2
Background
The purpose of this analysis is to describe the differences in cardiac magnetic resonance characteristics between benign and malignant tumors, which would be helpful for surgical planning.Methods
This was a prospective cohort study of 130 patients who underwent cardiac magnetic resonance imaging for evaluation of a suspected cardiac mass. After excluding thrombi and tumors without definitive diagnosis, 66 tumors were evaluated for morphologic features and tissue composition.Results
Of the 66 patients, 39 (59.0%) had malignant tumors and 27 (41.0%) had benign tumors. Patients with malignant tumors were younger when compared with those with benign tumors (age 51 years [42.8-60.0] vs 65 years [60.0-71.0] median). Malignant tumors more often demonstrated tumor invasion (69% vs 0% P < .001) and were more often associated with pericardial effusion (41% vs 7.4% P = .004). Presence of first-pass perfusion (100% vs 33% P < .001) and late gadolinium enhancement (100% vs 59.2%, P < .001) were significantly higher in malignant tumors. In logistic regression modeling, tumor invasion (P < .001) and first-pass perfusion (P < .001) were independently associated with malignancy. Furthermore, using classification and regression tree analysis, we developed a decision tree algorithm to help differentiate benign from malignant tumors (diagnostic accuracy ~90%). The algorithm-weighted cost of misclassifying a malignant tumor as benign was twice that of classifying a benign tumor as malignant.Conclusions
Our study demonstrates that cardiac magnetic resonance imaging is a useful noninvasive method for differentiating malignant from benign cardiac tumors. Tumor size, invasion, and first-pass perfusion were useful imaging characteristics in differentiating benign from malignant tumors. 相似文献7.
8.
9.
10.
Venom from the scorpion Pandinus imperator potently and selectively blocks voltage-gated K+ channels in bullfrog neurones (Pappone, P. A. and Cahalan, M. D. 1987, J. Neurosci. 7, 3300-3305). Its effects on neuromuscular transmission have now been assessed. Twitch tension studies on chick biventer cervicis preparations showed that the venom (1 microgram/ml and above) significantly augmented responses to nerve but not muscle stimulation; there was little change in postjunctional sensitivity to cholinoceptor agonists or K+-induced depolarization. Electrophysiological studies on mouse triangularis sterni preparations revealed that the venom had no effect on spontaneous transmitter release, but increased evoked transmitter release. Extracellular recordings of nerve terminal action potentials showed that the venom selectively reduced the component of the waveform associated with K+ currents. These results confirm that this venom can selectively block neuronal K+ currents, and they show that this can facilitate the release of acetylcholine at the neuromuscular junction. 相似文献