全文获取类型
收费全文 | 27676篇 |
免费 | 1915篇 |
国内免费 | 434篇 |
专业分类
耳鼻咽喉 | 327篇 |
儿科学 | 799篇 |
妇产科学 | 711篇 |
基础医学 | 2682篇 |
口腔科学 | 794篇 |
临床医学 | 2339篇 |
内科学 | 5656篇 |
皮肤病学 | 540篇 |
神经病学 | 1172篇 |
特种医学 | 996篇 |
外国民族医学 | 9篇 |
外科学 | 4610篇 |
综合类 | 1659篇 |
现状与发展 | 1篇 |
一般理论 | 21篇 |
预防医学 | 1985篇 |
眼科学 | 745篇 |
药学 | 2620篇 |
8篇 | |
中国医学 | 650篇 |
肿瘤学 | 1701篇 |
出版年
2024年 | 37篇 |
2023年 | 404篇 |
2022年 | 1134篇 |
2021年 | 1577篇 |
2020年 | 872篇 |
2019年 | 1025篇 |
2018年 | 1321篇 |
2017年 | 871篇 |
2016年 | 847篇 |
2015年 | 1033篇 |
2014年 | 1266篇 |
2013年 | 1541篇 |
2012年 | 2149篇 |
2011年 | 2154篇 |
2010年 | 1269篇 |
2009年 | 1051篇 |
2008年 | 1439篇 |
2007年 | 1509篇 |
2006年 | 1331篇 |
2005年 | 1126篇 |
2004年 | 1011篇 |
2003年 | 855篇 |
2002年 | 789篇 |
2001年 | 428篇 |
2000年 | 384篇 |
1999年 | 309篇 |
1998年 | 169篇 |
1997年 | 124篇 |
1996年 | 114篇 |
1995年 | 111篇 |
1994年 | 77篇 |
1993年 | 64篇 |
1992年 | 131篇 |
1991年 | 120篇 |
1990年 | 116篇 |
1989年 | 112篇 |
1988年 | 100篇 |
1987年 | 96篇 |
1986年 | 100篇 |
1985年 | 89篇 |
1984年 | 70篇 |
1983年 | 91篇 |
1982年 | 37篇 |
1981年 | 46篇 |
1979年 | 78篇 |
1978年 | 48篇 |
1977年 | 55篇 |
1976年 | 44篇 |
1975年 | 47篇 |
1974年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
大鼠心肌缺血再灌注时心肌细胞凋亡caspase-3活性变化规律及药物对其影响 总被引:3,自引:2,他引:1
目的 探讨大鼠心肌缺血再灌注 (Ischemiareperfusion ,IR)不同时相的心肌细胞凋亡、caspase 3活性变化规律及caspase 3抑制剂Ac DEVD CHO的影响。方法 Wistar大鼠 12 2只 ,设立IR组 ,IR +Ac DEVD CHO组和假手术对照组并分设缺血 3 0min后再灌注 1、3、6、12、2 4h 5个时相点 ;以缺口末端标记法 (TUNEL)标记凋亡细胞 ,用荧光分析法检测caspase 3活性 ,行TTC染色测定心肌梗死范围。结果 心肌细胞凋亡与caspase 3活性随心肌再灌注不同时相而变化 ,心肌细胞凋亡指数 (Apoptosisindex ,AI)与caspase 3活性于再灌注 12h最高 [AI :( 3 4 83± 9 3 5 ) % ;caspase 3活性 :( 1 3 4±0 2 ) ] ,其后基本维持在平台状态 ;心肌梗死范围随IR时间逐渐增加 ,至 2 4h仍未见下降趋势 ,三者间呈显著正相关 (P <0 0 5 )。IR +Ac DEVD CHO组上述指标虽也明显增高 ,但比IR组明显减小 (P <0 0 5 )。结论 Caspase 3激活及心肌细胞凋亡参与了心肌缺血再灌注损伤过程 ,Ac DEVD CHO减轻心肌缺血再灌注损伤可能部分与其抑制心肌细胞凋亡有关。 相似文献
43.
Histological, histochemical and electron microscopic changes of the placenta induced by maternal exposure to hyperthermia in the rat. 总被引:3,自引:0,他引:3
R Padmanabhan N M Al-Menhali I Ahmed H H Kataya M A Ayoub 《International journal of hyperthermia》2005,21(1):29-44
Both clinical and experimental investigations have shown that maternal hyperthermia during critical stages of embryo development can induce malformations in the offspring. Studies of the effect of heat stress on the placental functions are limited to the ewes, but that on microscopic structure is unknown. In the present study, rats were exposed to 41 or 42 degrees C for 1 h on gestation day (GD) 9. The controls were sham treated. Fetuses and placentas were collected on GD 20. Intrauterine growth retardation (IUGR) and several craniofacial malformations were observed in the fetuses of the heat-treated group. The placentas of the 42 degrees C group were significantly lighter in weight than those of the control. Light microscopy (LM) revealed thickening, hyalinization and occasional lymphocytic infiltration of the decidua basalis. Giant cells were prominent and glycogen cells had degenerated, leaving behind large cysts in the basal (spongy) zone. Best's carmine stain with or without diastase indicated the reduction in number and degeneration of glycogen cells and cyst formation. The labyrinthine zone was relatively thin in comparison to that of the controls. Perivascular fibrosis and paucity of vascularization were other features of the placentas of the hyperthermia group. Electron microscopy (EM) revealed lipid droplet accumulation in the trophoblast, the presence of myelin bodies and an increased production of collagen in the basal zone. Perivascular fibrosis appeared to have contributed to placental barrier thickening. EM also revealed accumulation of glycogen and lipid droplets in the trophoblasts and fibrin secretion into the extracellular space of the labyrinthine zone. These data suggest that placental pathology possibly contributes to fetal growth retardation in maternally heat-stressed rat fetuses. 相似文献
44.
45.
46.
Hassan Chamsi-Pasha Alaa Abdulmoneim Waqar H Ahmed Khaled F Al-Shaibi Aref Ajam Hassan Bakhamees Abdullah K Ashmeg 《Journal of the American Society of Echocardiography》2004,17(1):70-72
A 24-year-old man presented with a 24-hour history of pain and numbness in his left arm. The patient's clinical presentation of peripheral embolism was corroborated by angiography. Echocardiographic study showed masses in both right and left atria. Pathologic specimen from the embolus confirmed the diagnosis of aspergillosis. 相似文献
47.
Abstract Simultaneous bilateral avulsions of the tibial tuberosity are rare injuries. The authors found only five reported cases in
the orthopedic literature. We add a further case of bilateral avulsions of the tibial tuberosity with the longest reported
follow-up. 相似文献
48.
49.
K elZaki M E Ahmed A M elHassan M A Yousif A H Fahal 《The Journal of tropical medicine and hygiene》1991,94(3):206-209
This prospective study contains clinical and experimental parts. In the clinical study, 125 patients given intramuscular chloroquine for malaria were followed for 2 months in order to detect local injection site complications. Adequate local antiseptic conditions were ensured before giving the injection. Twenty-three patients (18.4%) had minimal local reaction in the form of redness, induration and/or a lump. No pyogenic abscess was noted in contrast to a previous report. In the second part of the study, an experimental animal (Green monkey) was given either chloroquine phosphate, Ampiclox or normal saline intramuscularly. The injection site was later biopsied and histologically examined. Intramuscular chloroquine was found to cause severe inflammatory reactions and muscle necrosis, whereas other injections had very minimal local effects. It is concluded that intramuscular chloroquine causes muscle necrosis which may lead to acute pyogenic abscess if minimal contamination takes place. 相似文献
50.
Ahmed M. Abu El-Asrar Eman S. Kahtani Khalid F. Tabbara 《Documenta ophthalmologica. Advances in ophthalmology》1995,89(4):313-320
In this report we describe, herewith, a patient with primary pigmentary dystrophy of the retina (retinitis pigmentosa) associated with unilateral retinal arteriovenous communication and exudative retinal detachment. The patient had complete resolution of the retinal detachment following laser photocoagulation treatment. Such association has not been previously reported. 相似文献