全文获取类型
收费全文 | 9221篇 |
免费 | 853篇 |
国内免费 | 122篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 303篇 |
妇产科学 | 156篇 |
基础医学 | 1262篇 |
口腔科学 | 209篇 |
临床医学 | 1132篇 |
内科学 | 1957篇 |
皮肤病学 | 127篇 |
神经病学 | 626篇 |
特种医学 | 587篇 |
外国民族医学 | 1篇 |
外科学 | 1358篇 |
综合类 | 225篇 |
一般理论 | 9篇 |
预防医学 | 910篇 |
眼科学 | 110篇 |
药学 | 606篇 |
中国医学 | 1篇 |
肿瘤学 | 560篇 |
出版年
2021年 | 92篇 |
2019年 | 109篇 |
2018年 | 153篇 |
2017年 | 84篇 |
2016年 | 102篇 |
2015年 | 120篇 |
2014年 | 162篇 |
2013年 | 285篇 |
2012年 | 360篇 |
2011年 | 382篇 |
2010年 | 214篇 |
2009年 | 228篇 |
2008年 | 376篇 |
2007年 | 434篇 |
2006年 | 416篇 |
2005年 | 403篇 |
2004年 | 356篇 |
2003年 | 320篇 |
2002年 | 348篇 |
2001年 | 303篇 |
2000年 | 294篇 |
1999年 | 241篇 |
1998年 | 192篇 |
1997年 | 178篇 |
1996年 | 178篇 |
1995年 | 137篇 |
1994年 | 124篇 |
1993年 | 153篇 |
1992年 | 204篇 |
1991年 | 201篇 |
1990年 | 226篇 |
1989年 | 211篇 |
1988年 | 189篇 |
1987年 | 197篇 |
1986年 | 165篇 |
1985年 | 191篇 |
1984年 | 140篇 |
1983年 | 100篇 |
1982年 | 87篇 |
1981年 | 82篇 |
1980年 | 87篇 |
1979年 | 123篇 |
1978年 | 92篇 |
1977年 | 76篇 |
1976年 | 98篇 |
1975年 | 88篇 |
1974年 | 86篇 |
1973年 | 82篇 |
1972年 | 87篇 |
1969年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Abra R. M. Hunt C. Anthony Fu K. K. Peters J. H. 《Cancer chemotherapy and pharmacology》1983,11(2):98-101
Cancer Chemotherapy and Pharmacology - Addition of solid doxorubicin or solutions to pre-formed liposomes proved to be the optimal method for incorporating the drug into liposomes whilst... 相似文献
2.
3.
4.
Leonard A. Jason PhD Steven B. Pokorny PhD Monica Adams MPH Annie Topliff MA Courtney Harris BA Yvonne Hunt PhD 《The American journal on addictions / American Academy of Psychiatrists in Alcoholism and Addictions》2009,18(5):367-374
This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty‐four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use. 相似文献
5.
6.
7.
This study assessed the capabilities of a traditional and an amplified stethoscope used by flight nurses to assess breath sound during air medical transport in an MBB BO-105 helicopter. We developed a normal breath sound model using a prerecorded tape of breath sounds interspersed with segments without breath sounds; the recorder had been placed in the chest wall of a resuscitation training manikin. Flight nurses completed control listening sessions in a quiet environment and experimental sessions during flight using a traditional stethoscope for half of the sessions and an amplified stethoscope for the remaining half. In the quiet environment, flight nurses accurately reported the presence or absence of breath sounds in 110 (92%) of 120 trials. During helicopter flight, none of the flight nurses heard breath sounds during any of the recorded segments with either the traditional stethoscope or the amplified stethoscope. We conclude that flight nurses are unable to hear normal breath sounds using a traditional or amplified stethoscope during flight in a medically configured MBB BO-105 helicopter. Improved stethoscopes, innovative methods of listening, and reduction of aircraft noise are potential solutions to the problems of breath sound assessment during air medical transport. 相似文献
8.
9.
Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D100) were determined and vessels were set up to a normalized internal diameter (0.9 D100). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells. 相似文献
10.