全文获取类型
收费全文 | 52980篇 |
免费 | 2345篇 |
国内免费 | 402篇 |
专业分类
耳鼻咽喉 | 589篇 |
儿科学 | 1087篇 |
妇产科学 | 593篇 |
基础医学 | 6719篇 |
口腔科学 | 1049篇 |
临床医学 | 3128篇 |
内科学 | 13346篇 |
皮肤病学 | 1360篇 |
神经病学 | 3998篇 |
特种医学 | 2152篇 |
外科学 | 8984篇 |
综合类 | 215篇 |
一般理论 | 7篇 |
预防医学 | 1468篇 |
眼科学 | 1127篇 |
药学 | 3566篇 |
中国医学 | 181篇 |
肿瘤学 | 6158篇 |
出版年
2023年 | 295篇 |
2022年 | 600篇 |
2021年 | 1036篇 |
2020年 | 564篇 |
2019年 | 785篇 |
2018年 | 1073篇 |
2017年 | 831篇 |
2016年 | 1031篇 |
2015年 | 1107篇 |
2014年 | 1436篇 |
2013年 | 1805篇 |
2012年 | 2917篇 |
2011年 | 3253篇 |
2010年 | 1840篇 |
2009年 | 1670篇 |
2008年 | 3044篇 |
2007年 | 3268篇 |
2006年 | 3310篇 |
2005年 | 3325篇 |
2004年 | 3415篇 |
2003年 | 3432篇 |
2002年 | 3412篇 |
2001年 | 859篇 |
2000年 | 772篇 |
1999年 | 897篇 |
1998年 | 870篇 |
1997年 | 728篇 |
1996年 | 686篇 |
1995年 | 573篇 |
1994年 | 518篇 |
1993年 | 539篇 |
1992年 | 547篇 |
1991年 | 525篇 |
1990年 | 478篇 |
1989年 | 458篇 |
1988年 | 437篇 |
1987年 | 372篇 |
1986年 | 298篇 |
1985年 | 321篇 |
1984年 | 280篇 |
1983年 | 226篇 |
1982年 | 166篇 |
1981年 | 179篇 |
1980年 | 159篇 |
1979年 | 167篇 |
1978年 | 157篇 |
1977年 | 130篇 |
1976年 | 96篇 |
1975年 | 83篇 |
1974年 | 90篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
C. Vyvyan Howard Luis M. Cruz-Orive Hiroshi Yaegashi 《Acta neurologica Scandinavica》1992,85(S137):14-19
The recently developed method of total vertical projections is illustrated to estimate the total dendritic length of a human Substantia Nigra neuron. Next, the length of the different orders of dendritic branches, and the mean segment length for each order - commonly regarded as important parameters in neuron physiology - are also estimated. Finally, it is shown how to estimate the mean dendritic length in a population of neurons from vertical slices of arbitrary and unknown thickness. Being unbiased and highly efficient, the proposed methods offer interesting alternatives to current procedures used for the metric analysis of neuron arborizations. 相似文献
62.
63.
64.
65.
Yoshihide Nagasako Meang Bong Jin Hiroshi Miyazaki Masato Nakayama Tsuyoshi Shimamura Hiroyuki Furukawa Michiaki Matushita Satoru Todo 《Liver transplantation》2006,12(3):435-439
Thrombocytopenia is a frequent finding following living donor hepatectomy. It appears more pronounced in right graft donors than in left graft donors. This study analyzed postoperative thrombocytopenia in 20 living liver donors and examined the change of endogenous thrombopoietin (TPO) in its recovery. Platelet count, TPO level, fibrinogen degradation product (FDP), and D-Dimer were measured before surgery and on postoperative days (PODs) 1, 2, 3, 5, 7, and 14. Concurrently, liver and spleen volumes were calculated by computed tomography. Platelet count on POD 3 was significantly lower in right graft donors than in left graft donors (13.0 +/- 3.7 x 10(4)/microL vs. 16.8 +/- 4.0 x 10(4)/microL, P = 0.039) but recovered by POD 7 in all donors. Postoperative elevations of FDP and D-Dimer were significantly higher in right graft donors than in left graft donors. TPO level rose immediately after surgery, peaked on POD 5 in left graft donors and on POD 7 in right graft donors, and fell nearly to preoperative levels by POD 14. Postoperative TPO level per liver volume was significantly higher in right graft donors than in left graft donors. In conclusion, thrombocytopenia following living donor hepatectomy resolved within the first week regardless of graft type and was mainly associated with increasing consumption of circulating platelets, possibly due to intrahepatic and splenic congestion. With a reduced number of circulating platelets, TPO level rapidly increases. Also, with reduced consumption of platelets related to recovery from surgery, thrombocytopenia should resolve. As a consequence, TPO level would be expected to fall. 相似文献
66.
Arrhythmogenic right ventricular dysplasia/cardiomyopathy assessed with 64-slice computed tomography
Nishiyama Kei; Tadamura Eiji; Kanao Eitaro; Shizuta Satoshi; Furukawa Yutaka; Nakagawa Yoshihisa; Kimura Takeshi; Kita Toru 《European heart journal》2006,27(22):2666
A 69-year-old man was admitted to hospital because of sustainedventricular tachycardia with right bundle branch block morphology.After abolition of ventricular tachycardia, an electrocardiogramshowed atrial fibrillation, complete right bundle 相似文献
67.
Takeshi Uchida Yutaka Ohtaki Hideaki Kido Hiroshi Shinyama Kazutaka Hayashi Katsumi Yamanaga Masahiro Watanabe 《Drug development research》1992,26(2):203-212
The diuretic and the antihypertensive actions of torasemide were examined in renal and genetic hypertensive rats and compared to the effects of furosemide. Oral administration of torasemide (1 and 3 mg/kg) elicited a dose-dependent increase in the excretion of urine and electrolytes and elevated the urinary Na/K ratio in both renal and genetic hypertensive rats. Torasemide and furosemide had a similar maximum diuretic effect in the normotensive Wistar rat and the spontaneously hypertensive rat (SHR). However, the diuretic activity of furosemide was weaker in the renal hypertensive rat (RHR). Torasemide showed approximately 30 times greater diuretic potency than furosemide. Torasemide and furosemide demonstrated hypotensive action in hypertensive rat models, but not in the normotensive Wistar rat. Especially in the RHR, torasemide exhibited a more potent hypotensive action than furosemide. These results show that the diuretic and antihypertensive activities of torasemide are effective in various rat models of hypertension, while the diuretic activity of furosemide is weak in certain hypertensive rat models. © 1992 Wiley-Liss, Inc. 相似文献
68.
Kazuhiko Suzuki Hiroshi Tanaka Satoshi Kaneko Motoi Nishi Shin Teramoto Susumu Itoh Shosaku Abe 《The Journal of asthma》2003,40(3):243-250
The relation between smoking and risk of asthma has been well-examined; however little attention has been paid to the correlation between smoking and asthma symptoms. The aims of this study were to examine respiratory symptoms in asthmatics with a highly prevalent use of inhaled corticosteroid (ICS) and to assess the effects of smoking and its cessation. A cross-sectional study of pulmonologist-based 3197 asthmatics (men 45.2%, ages 20-97) was performed using a questionnaire about smoking habits, the incidence and frequency of symptoms (sputum, cough and wheezing, night symptoms, and shortness of breath), physical activity interference, and medication. Although 81.4% of the patients used ICS according to the international guideline, 14.9% had activity interference, and daily symptoms remained in 43.3%. At the time of the questionnaire, 21.6% were current and 25.1% were ex-smokers. In multiple logistic regression analysis, the factors of significance (p < 0.0001) were (1) smoking; for all four symptoms, (2) age and duration of asthma; for shortness of breath. Current smokers were at a risk of sputum (age-adjusted odds ratio 2.32 [95% confidence interval 1.73-3.11]; 2.09 [1.57-2.79]), of cough and wheezing (2.38 [1.81-3.14]; 1.78 [1.35-2.36]), of night symptoms (1.95 [1.41-2.60]; 1.47 [1.09-1.98]), and of shortness of breath (1.70 [1.26-2.28]; 1.30 [0.97-1.75]) in men and women, respectively. These ratios in ex-smokers decreased to the level similar to nonsmokers. Although 81.4% of asthmatic patients used ICS, 43.3% complained of daily respiratory symptoms, especially sputum. It is suggested that the effects of ICS on asthma symptoms may be interfered with by smoking and therefore more emphasis should be placed on cessation of smoking. 相似文献
69.
70.
Koichi Tanaka Kazue Ozawa Satoshi Teramukai Yasutsugu Takada Hiroto Egawa Satoshi Kaihara Yasuhiro Fujimoto Yasuhiro Ogura Mureo Kasahara Masako Ono Hiroshi Sato Kenji Takai Masanori Fukushima Nagahiro Minato 《Liver transplantation》2006,12(5):792-800
The primed status of T cells is markedly different among liver transplant recipients, due to a lifetime of antigen exposure and reduced thymopoiesis by aging, and diseases. This study aims to characterize the preoperative immunological status of CD8+ T cell subpopulations and relate it to the outcome for liver transplant recipients. We classified 112 liver transplant recipients into 5 groups, based on hierarchical clustering of the CD8+CD45 isoform proportion of T cells. In Groups I and II (pediatric), the naive T cell proportion was more than 50%. In adult recipients, Group III was characterized by a naive T cell proportion of 50%, Group IV had the greatest effector/memory T cells (EM), and Group V had the greatest proportion of effector T cells. In Groups IV and V, the effector T cell proportion was considerably higher, and was accompanied by marked downregulation of the CD27+CD28+ subsets and upregulation of interferon gamma (IFN)-gamma, tumor necrosis factor-alpha, and perforin expression. Group V recipients tended to be complicated postoperatively, with a significantly reduced survival rate (1 yr, 66.8%) and markedly reduced Eastern Cooperative Oncology Group performance status. 相似文献