全文获取类型
收费全文 | 18654篇 |
免费 | 888篇 |
国内免费 | 141篇 |
专业分类
耳鼻咽喉 | 170篇 |
儿科学 | 379篇 |
妇产科学 | 141篇 |
基础医学 | 2505篇 |
口腔科学 | 426篇 |
临床医学 | 1205篇 |
内科学 | 4828篇 |
皮肤病学 | 349篇 |
神经病学 | 1694篇 |
特种医学 | 701篇 |
外科学 | 3039篇 |
综合类 | 85篇 |
预防医学 | 510篇 |
眼科学 | 408篇 |
药学 | 1183篇 |
中国医学 | 43篇 |
肿瘤学 | 2017篇 |
出版年
2024年 | 12篇 |
2023年 | 128篇 |
2022年 | 235篇 |
2021年 | 426篇 |
2020年 | 217篇 |
2019年 | 338篇 |
2018年 | 438篇 |
2017年 | 352篇 |
2016年 | 444篇 |
2015年 | 455篇 |
2014年 | 570篇 |
2013年 | 707篇 |
2012年 | 1182篇 |
2011年 | 1335篇 |
2010年 | 716篇 |
2009年 | 601篇 |
2008年 | 1164篇 |
2007年 | 1314篇 |
2006年 | 1229篇 |
2005年 | 1342篇 |
2004年 | 1285篇 |
2003年 | 1274篇 |
2002年 | 1186篇 |
2001年 | 196篇 |
2000年 | 149篇 |
1999年 | 214篇 |
1998年 | 274篇 |
1997年 | 212篇 |
1996年 | 181篇 |
1995年 | 185篇 |
1994年 | 142篇 |
1993年 | 134篇 |
1992年 | 104篇 |
1991年 | 103篇 |
1990年 | 81篇 |
1989年 | 98篇 |
1988年 | 75篇 |
1987年 | 69篇 |
1986年 | 61篇 |
1985年 | 48篇 |
1984年 | 50篇 |
1983年 | 43篇 |
1982年 | 37篇 |
1981年 | 40篇 |
1980年 | 39篇 |
1979年 | 30篇 |
1978年 | 30篇 |
1977年 | 23篇 |
1976年 | 21篇 |
1975年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 236 毫秒
91.
92.
93.
94.
95.
The chemical and radio toxicity of 125-5-iodo-2-deoxyuridine (125IUDR) on 870127T human lung cancer (HLC) cells grown in tissue cultures and the quantitative analysis of the distribution and fate of 125IUDR-labeled 870127T HLC cells in nude mice were evaluated. After 870127T HLC cells were plated and 125IUDR was added to the dishes at levels ranging from 0.1 µCi/ml to 5.0 µCi/ml of media, the growth rate of the cells for 24h was similar to that of non-labeled cells. Nude mice were given intravenous injections of 125IUDR labeled 870127T HLC cells and killed at various intervals ranging from 5 min to 24 h after injection. Organs were collected, processed, and monitored. The lung contained most of the tumor cells at all intervals and the number of tumor cells in the lung decreased gradually post-injection. The tumor cells died rapidly, and only about 1.5% of all cell survived after 24 h post-injection. This study confirmed that very few surviving tumor cells are needed to cause metastasis. 相似文献
96.
Gennady E. Tur M.D. Hitoshi Kotanagi M.D. Dr. Kenji Koyama M.D. 《Diseases of the colon and rectum》1994,37(6):604-605
A modified technique for handsewn anastomosis after abdominoperineal pull-through resection is described. The technique is a continuous locked modification of the Gambee suture. Simplicity, rapidity, reliability, and firmness are the advantages of this technique. 相似文献
97.
Hiromichi Yamada Yasushi Suga Kenji Takamori Hideoki Ogawa 《The Journal of dermatology》1994,21(6):394-396
The stoichiometry of the reaction catalyzed by skin sulfhydryl oxidase was investigated. Dithiothreitol (DTT) was used as the substrate for skin sulfhydryl oxidase. The consumption of DTT, consumption of oxygen, and production of hydrogen peroxide were measured during the enzyme reaction. The molar ratio of DTT:O2:H2O2 in the enzyme reaction was 1:1.02:0.89. Correspondingly, the stoichiometry of the enzyme reaction was calculated to be R(SH)2 + O2 → + H2O2. 相似文献
98.
4-Phenyl-1-(4-phenylbutyl)piperidine(4-PPBP) is a very potent ligand for σ (Sigma) receptors. The present study was undertaken to evaluate [3H]4-PPBPas a radioligand for in vivo labeling of cerebral σ receptors. After intravenous administration of [3H]4-PPBP to mice, there is high uptake of radioactivity in the brain. The regional distribution of radioactivity in the brain 2 h after intravenous injection of [3H]4-PPBP parallels the in vitro binding of the radioligand in rat brain (pons/medulla > cerebellum ≥ prefrontal cortex ≥ parietal cortex > hypothalamus > olfactory tubercle ≥ thalamus > hippocampus > striatum). Pretreatment with haloperidol (2 mg/kg) significantly decreases the radioactivity measured in the brain 30–120 min after injection of [3H]4-PPBP. Pretreatment with unlabeled 4-PPBP or ifenprodil also significantly decreases radioactivity in the brain 2 h after injection of [3H]4-PPBP, in a dosedependent manner. The in vivo binding of [3H]4-PPBP in the brain also is significantly inhibited by SL 82.0715, BMY 14802, 1,3-di-o-tolylguanidine (DTG), and (+)-enantiomers of pentazocine, SKF 10,047, and 3-PPP, but not by the corresponding (?)-enantiomers, consistent with stereoselectivity of inhibition obtained in in vitro binding studies. In contrast, pretreatment with dizocilpine and spiperone does not inhibit in vivo binding of [3H]4-PPBP. The results indicate that [3H]4-PPBP would be a suitable radioligand for in vivo labeling of σ receptors in brain. © 1995 Wiley-Liss, Inc. 1 This article is a US Government work and, as such, is in the public domain in the United States of America . 相似文献
99.
Lin Y Kawamura T Anno T Ichihara Y Ohta T Saito M Fujioka Y Kimura M Okada T Kuwayama Y Wakai K Ohno Y 《Environmental health and preventive medicine》1999,4(3):117-121
It is well known that physical exercise can reduce coronary risk factors. But how an aerobic exercise modifies coronary risk
factors in relation to severity and physical fitness is still controversial.
Fifty-four middle-aged women (mean age, 55 years) completed a 6-month on-site and home-based anaerobic threshold-level exercise
program. The changes in coronary risk factor profiles were observed during the pre-intervention and intervention periods.
Before the intervention (during control period), most coronary risk factors showed a rather unfavorable trend. After the program,
their mean body weight decreased from 56.7 to 55.7 kg (p>0.05) and the proportion of body fat from 30.9 to 27.9% (p>0.05)
without any reduction in lean body mass. Systolic blood pressure (SBP) decreased from 129.0 to 125.0 mm Hg (p>0.05) and diastolic
blood pressure from 79.5 to 76.6 mm Hg (p>0.05). Fasting plasma glucose (FPG) declined from 109.6 to 103.4 mg/dl (p>0.05).
Changes in SBP and FPG were most remarkable in their respective worst tertile. Serum lipids improved only modestly. Maximum
oxygen uptake increased from 23.6 to 26.1 ml/kg/min (p>0.01). However, no significant correlations were found between changes
in coronary risk factors and those in physical fitness. We conclude that the 6-month aerobic exercise program would modify
women’s coronary risk factors depending on their initial values, probably independently of the changes in physical fitness. 相似文献
100.
Abstract
A developing child, with a high metabolic
rate and low body stores of nutrients, is susceptible to metabolic
disturbances due to surgical stress. For perioperative nutritional care
of infants, the distinct physiologic features of their body fluids must
be carefully considered. The postoperative metabolic response is the
same as that in adults, but in children this response is more rapid.
Based on the urinary excretion of 3-methylhistidine in infants, the
postoperative degradation of muscle protein is thought to be twice the
preoperative level. This transient increase during the early
postoperative period was not suppressed by increased amino acid intake,
and energy intake was sufficient. To prevent postoperative metabolic
complications, the energy intake of glucose or fat should correspond to
the patient—s requirements, and excess carbohydrate should be avoided. The quantity and quality of the amino acid formula
used must be
carefully evaluated.
E-pub: 31 October 2000 相似文献