全文获取类型
收费全文 | 56226篇 |
免费 | 3105篇 |
国内免费 | 598篇 |
专业分类
耳鼻咽喉 | 985篇 |
儿科学 | 630篇 |
妇产科学 | 825篇 |
基础医学 | 9770篇 |
口腔科学 | 1352篇 |
临床医学 | 4888篇 |
内科学 | 10550篇 |
皮肤病学 | 1872篇 |
神经病学 | 3986篇 |
特种医学 | 2971篇 |
外科学 | 7492篇 |
综合类 | 213篇 |
现状与发展 | 1篇 |
一般理论 | 17篇 |
预防医学 | 2715篇 |
眼科学 | 1233篇 |
药学 | 4986篇 |
中国医学 | 626篇 |
肿瘤学 | 4817篇 |
出版年
2023年 | 429篇 |
2022年 | 1331篇 |
2021年 | 2057篇 |
2020年 | 987篇 |
2019年 | 1288篇 |
2018年 | 1665篇 |
2017年 | 1240篇 |
2016年 | 1759篇 |
2015年 | 2560篇 |
2014年 | 3059篇 |
2013年 | 3489篇 |
2012年 | 5319篇 |
2011年 | 4816篇 |
2010年 | 2806篇 |
2009年 | 2365篇 |
2008年 | 3425篇 |
2007年 | 3095篇 |
2006年 | 2654篇 |
2005年 | 2357篇 |
2004年 | 2030篇 |
2003年 | 1698篇 |
2002年 | 1440篇 |
2001年 | 1364篇 |
2000年 | 1262篇 |
1999年 | 906篇 |
1998年 | 362篇 |
1997年 | 252篇 |
1996年 | 208篇 |
1995年 | 177篇 |
1994年 | 149篇 |
1993年 | 132篇 |
1992年 | 332篇 |
1991年 | 316篇 |
1990年 | 280篇 |
1989年 | 258篇 |
1988年 | 247篇 |
1987年 | 248篇 |
1986年 | 177篇 |
1985年 | 165篇 |
1984年 | 119篇 |
1983年 | 111篇 |
1982年 | 55篇 |
1981年 | 58篇 |
1979年 | 81篇 |
1978年 | 68篇 |
1975年 | 50篇 |
1974年 | 60篇 |
1973年 | 51篇 |
1972年 | 50篇 |
1970年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Hyun-Min Shin Chul-Jong Park Jong-Yuk Yi Tae-Yoon Kim Chung-Won Kim 《Pediatric dermatology》1996,13(2):146-147
Abstract: Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before. 相似文献
23.
24.
The effect of local administration of vasodilative concentrations of the adenosine receptor agonist 2-chloroadenosine (2-CADO) on the hyperemic responses of the pial and parenchymal microcirculations to graded hypercapnia was determined. The cranial window and brain microdialysis-hydrogen clearance techniques were utilized in two groups of isoflurane-anesthetized newborn pigs to measure changes in pial diameters and local CBF, respectively, in response to graded hypercapnia in the absence and presence of 2-CADO. Progressive size-dependent dilations of pial arterioles [small = 41 +/- 7 microns (mean +/- SD), intermediate = 78 +/- 13 microns, and large = 176 +/- 57 microns in diameter] occurred in response to graded hypercapnia alone (PaCO2 = 58 and 98 mm Hg) and to superfusions of 2-CADO (10(-5) M) during normocapnia; the magnitude of the dilative response to each of these stimuli was inversely proportional to vessel size. When hypercapnia was induced concomitantly with 2-CADO superfusion, the dilative effects of each stimulus were directly additive. Similarly, local microdialysis infusion of 10(-5) M 2-CADO, which doubled CBF during normocapnia, did not affect the hyperemic response of the parenchymal circulation to graded hypercapnia (PaCO2 = 69 and 101 mm Hg). Our findings are consistent with the participation of adenosine in the mediation of cerebral hypercapnic hyperemia. If, however, adenosine is not involved in this dilative response, our results indicate that concomitant vascular and neuromodulatory actions induced by adenosine receptor stimulation do not affect the mechanism responsible for the hypercapnic hyperemic response. 相似文献
25.
26.
M Shaves D Barnhill J Bosscher S Remmenga M Hahn R Park 《Obstetrics and gynecology》1991,77(4):642-644
Seven patients with severe pain caused by an advanced, incurable gynecologic malignancy were treated with an indwelling epidural catheter connected to an implantable subcutaneous port through which morphine was infused. There were few major complications associated with insertion or maintenance of the system. The average usage was 60 days, although the system functioned continuously for 6 months in one patient. Pain distribution in these women ranged from the upper abdomen to the lower extremities. All patients, including one with liver metastases, reported good to excellent pain control with the epidural narcotics. Two subjects with upper abdominal pain occasionally required supplemental oral oxycodone, but the other five patients had adequate pain relief with the epidural system alone. The indwelling epidural system provides excellent analgesia for patients with advanced, incurable gynecologic cancer. 相似文献
27.
Selective inactivation of viruses in the presence of human platelets: UV sensitization with psoralen derivatives. 下载免费PDF全文
R P Goodrich N R Yerram B H Tay-Goodrich P Forster M S Platz C Kasturi S C Park N J Aebischer S Rai L Kulaga 《Proceedings of the National Academy of Sciences of the United States of America》1994,91(12):5552-5556
Inactivation of viruses in blood products requires that the method employed display selectivity in its action for viral elements while not affecting the biological entity of interest. Several methods have been developed for the treatment of human plasma or products derived from human plasma. An effective technique for the treatment of the cellular components of blood has been lacking, in part due to the inability to develop agents capable of selectively targeting viral agents in the milieu of cellular material. In this paper, we examine the behavior of a group of viral sensitizers designed to be added to cellular samples and be activated upon exposure to UVA light. Upon activation, these agents are capable of disrupting nucleic acids of the virus in a manner that renders them inactive for proliferation. The selectivity observed in this inactivation is determined by the chemical structure of the sensitizer, which can be varied to increase viral killing capacity while diminishing collateral damage to cellular and protein constituents. 相似文献
28.
Effects of inotropes on human leucocyte numbers, neutrophil function and lymphocyte subtypes 总被引:1,自引:1,他引:0
Burns A. M.; Keogan M.; Donaldson M.; Brown D. L.; Park G. R. 《British journal of anaesthesia》1997,78(5):530-535
We have investigated the effects of inotropes with different adrenergic
receptor specificity on differential white cell count, lymphocyte subtypes
and neutrophil function in healthy volunteers. Six healthy, male volunteers
were enrolled into this randomized, placebo-controlled pilot study. Each
volunteer was studied on four separate occasions during a 2-h infusion of
various agents, and for 2 h after stopping the infusion. The agents
investigated were adrenaline 0.1 microgram kg-1 min-1, dobutamine 5
micrograms kg-1 min-1, dopexamine 2 micrograms kg-1 min-1 and 5% glucose
0.5 ml kg-1 h-1. Venous blood was sampled at 0, 30, 120 and 240 min.
Haemodynamic monitoring was continued throughout the study. Full blood
count, white cell differential count and enumeration of lymphocyte subtypes
were performed. Neutrophil function tests included chemoluminescence, and
assessment of neutrophil chemotaxis, phagocytosis and adhesion. The
Wilcoxon signed rank test was used to compare differences between placebo
and active drugs at each time compared with baseline. There was a
significant increase in white cell count, lymphocyte count and neutrophil
count with adrenaline, and a small but significant decrease in these
variables with dobutamine and dopexamine. These changes were also apparent
for absolute CD3+, CD4+ and CD8+ lymphocyte counts. Neutrophil respiratory
burst in response to f-methionyl-leucyl-phenylalanine increased
significantly only with adrenaline at 30 min (P = 0.046). There were no
other significant changes in tests of neutrophil function. Infusion of
inotropes was associated with changes in white cell numbers, lymphocyte
subtypes and neutrophil respiratory burst. In healthy volunteers,
adrenaline had effects different from those of dobutamine and dopexamine.
The clinical relevance of such effects requires further investigation in
critically ill patients.
相似文献
29.
We present three unusual cases of molluscum contagiosum occurring in epidermal cysts. All of them are asymptomatic, elevated, oval nodules diagnosed clinically as epidermal inclusion cyst or prurigo nodularis. Histology showed true epidermal cysts containing molluscum bodies throughout the cyst wall and some type of laminated material within the cyst itself. The lesion, in all three cases developed in the pubic area of young adult men. 相似文献
30.