全文获取类型
收费全文 | 53146篇 |
免费 | 3018篇 |
国内免费 | 2364篇 |
专业分类
耳鼻咽喉 | 140篇 |
儿科学 | 1104篇 |
妇产科学 | 1085篇 |
基础医学 | 2849篇 |
口腔科学 | 129篇 |
临床医学 | 7632篇 |
内科学 | 3964篇 |
皮肤病学 | 84篇 |
神经病学 | 11542篇 |
特种医学 | 2483篇 |
外国民族医学 | 2篇 |
外科学 | 2902篇 |
综合类 | 12246篇 |
现状与发展 | 2篇 |
预防医学 | 2201篇 |
眼科学 | 598篇 |
药学 | 5740篇 |
90篇 | |
中国医学 | 3487篇 |
肿瘤学 | 248篇 |
出版年
2024年 | 104篇 |
2023年 | 518篇 |
2022年 | 1129篇 |
2021年 | 1680篇 |
2020年 | 1627篇 |
2019年 | 1319篇 |
2018年 | 1305篇 |
2017年 | 1657篇 |
2016年 | 1851篇 |
2015年 | 1939篇 |
2014年 | 3632篇 |
2013年 | 3504篇 |
2012年 | 3498篇 |
2011年 | 3644篇 |
2010年 | 3136篇 |
2009年 | 2769篇 |
2008年 | 2695篇 |
2007年 | 2739篇 |
2006年 | 2630篇 |
2005年 | 2364篇 |
2004年 | 1973篇 |
2003年 | 1790篇 |
2002年 | 1493篇 |
2001年 | 1298篇 |
2000年 | 1116篇 |
1999年 | 950篇 |
1998年 | 737篇 |
1997年 | 693篇 |
1996年 | 501篇 |
1995年 | 484篇 |
1994年 | 454篇 |
1993年 | 365篇 |
1992年 | 313篇 |
1991年 | 319篇 |
1990年 | 233篇 |
1989年 | 225篇 |
1988年 | 192篇 |
1987年 | 182篇 |
1986年 | 184篇 |
1985年 | 238篇 |
1984年 | 189篇 |
1983年 | 139篇 |
1982年 | 151篇 |
1981年 | 183篇 |
1980年 | 112篇 |
1979年 | 75篇 |
1978年 | 53篇 |
1977年 | 38篇 |
1976年 | 39篇 |
1975年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
101.
Cerebralvasospasm(CVS)remainsoneofthemajorcausesofseriousoutcomeinpatientswithsubarachnoidhemorrhage(SAH);however,themechanismofwhichisstillnotwellunderstood.Sofaralargenumberofputativespasmogenshavebeenproposedandoneofwhichisendothelins(ETs).ETs,akindofverypotentendogenousvasoconstrictorsubstancesknown[1],hasthreeiso-forms:ET-1,2and3,andET-1isthemostpo-tentvasoconstrictorofthem.lnrecentstudies,ET-lhasbeenproposedasamediatorofCVSfol-lowingSAH[2-4j.TheavailabilityofETantagonistprovided… 相似文献
102.
急性脑梗塞患者血清肿瘤坏死因子水平变化的观察 总被引:7,自引:0,他引:7
采用双抗体夹心ELISA法对30例正常对照和36例急性脑梗塞患者血清肿瘤坏死因子(TNF)水平进行了检测。结果显示:急性脑梗塞组血清TNF水平显著高于正常对照组,血清TNF水平变化与脑梗塞容积大小密切相关,恢复期血清TNF水平显著降低。结果提示,TNF参与了脑梗塞发生后病理变化过程,检测血清TNF对判定脑梗塞容积大小有一定的临床意义。 相似文献
103.
Kazumichi Yamada Satoshi Goto Taro Oyama Makoto Yoshikawa Shinji Nagahiro Yukitaka Ushio 《Acta neuropathologica》1995,89(2):172-177
The present study concerns the vulnerability of striatal interneurons immunopositive for the Ca2+-binding protein calretinin to ischemic neuronal injury. An immunohistochemical study was carried out on the striata of rats which had undergone transient middle cerebral artery occlusion. Two weeks after the ischemia, there was a marked reduction in the number of calretinin-positive neurons in the ipsilateral ischemic lesion, although the striatal interneurons positive for parvalbumin, which are a neuronal population distinct from the calretinin-immunoreactive cells in the striatum, were spared in the insulted areas. The present data indicate that the striatal calretinin-positive neurons are less resistant to transient ischemia, suggesting that there may exist vulnerability differences among the striatal interneurons in ischemia-induced neuronal injury. 相似文献
104.
William M. Chadduck Duc H. Duong John M. Kast David J. Donahue 《Child's nervous system》1995,11(10):579-583
Cerebellar hemorrhage is a devastating condition with morbidity and mortality related not only to the etiology of the hemorrhage, but also to the timing of the intervention. Sixteen consecutive pediatric patients with acute cerebellar hemorrhages are presented: 6 had vascular abnormalities, 3 had tumors, and 2 had hemorrhages of unknown etiology. Thirteen of the 16 patients survived with only 1 of the 13 having persistent vegetative state as a neurologic outcome. Six of 8 patients presenting in a moribund condition had good outcomes, and 3 of 4 patients presenting with fixed and dilated pupils also had good outcomes. Thus, in contrast to adults, rapid evaluation by CT scanning, followed by the judicious use of ventricular drainage and prompt surgical treatment, have resulted in favorable outcomes in pediatric patients despite their poor clinical presentations. None of the neonates having cerebellar hemorrhages required surgical intervention; their courses could be followed clinically and with transfontanel ultrasound.Presented as a poster at the 14th Congress of the European Society for Paediatric Neurosurgery, Lyon, France, 21–23 September 1994, and the XXII Annual Meeting of the International Society for Pediatric Neurosurgery, Birmingham, UK, 25–28 September 1994 相似文献
105.
Summary A simple technique of stereotactic craniotomy and intraoperative lesion localisation that uses the Brown-Robert-Wells (BRW) stereotactic frame is presented. The method optimises craniotomy placement and facilitates localisation of small intracerebral lesions. Using the system, 16 patients have had resection of intracranial neoplasms from deep and/or eloquent areas of the brain with no neurological morbidity. 相似文献
106.
研究深低温停循环(DHCA)与逆行脑灌注(RCP)时脑组织自由基的变化。健康杂种犬14只,随机等分为DHCA组和RCP组,在停循环前(A点)、DHCA/RCP30分(B点)、DHCA/RCP60分(C点)DHCA/RCP90分(D眯)和复温再灌注30分(E点)取脑皮层lg,检测丙二醛(MDA)和超氧化物歧化酶(SOD)水平。结果见两组在A点MDA和SOD无差别。在B、C、D、E点,DHCA组MDA 相似文献
107.
一氧化氮含量在急性脑梗死不同时期变化的临床意义 总被引:4,自引:0,他引:4
目的和方法为探讨急性脑梗死不同时期一氧化氮(NO)含量变化的临床意义,送检42例急性脑梗死患者不同时期的血清,采用Green改良法检测NO和以邻苯三酚自氧化法检测超氧化物歧化酶(SOD)含量,并配有30例正常对照。结果结果表明:脑梗死早期NO、SOD含量显著降低;急性期NO含量增高,并超过正常对照,而SOD含量进一步下降;脑梗死稳定期后,NO含量有所下降,接近正常水平,SOD含量增高,但仍低于正常。结论据上述结果提示,NO在急性脑梗死不同时期具有细胞毒性和组织保护双重作用,为临床寻求一种急性脑梗死的可能有效治疗方法提供了理论依据。 相似文献
108.
本文阐述了奥美拉唑(Omeprazole)治疗急性上消化道大出血80例与法莫替丁(Famotidine)治疗上消化道大出血50例比较,前者有效率明显高于后者。提示奥美拉唑治疗急性上消化道大出血效果好,无副作用,减少了手术率、死亡率,是一种有效的止血药物。 相似文献
109.
报告应闭合式玻璃体切除术治疗7例(7眼)因视网膜静脉阻塞所致的玻璃体出血。所有病人术后眼底清晰可见,视力明显提高。术后4例出现再出血,经药物治疗后出血吸收,加用氩离子激光视网膜光凝,无再出血。随访3至18个月所有病人无新生血管性青光眼及牵引性视网膜脱离出现。认为玻璃体切除术不但能使屈光间质恢复透明,视力提高,预防牵引性视网膜脱离,而且为明确诊断和进一步激光治疗提供条件。 相似文献
110.
Erika G. Gisel 《Occupational therapy international》1994,1(4):209-232
This review addresses the current state of knowledge in oral sensorimotor therapy for children with neurological impairments and ingestive problems. Comprehensive assessment of the child with dysphagia looks at the interaction of oral performance and growth. These domains include eating efficiency, oral-motor skills, oral sensory evaluation, classification of the severity of an eating problem, interaction of respiration and ingestion, aspiration, positioning for feeding, social skills assessment, careload and assessment technologies. Oral sensorimotor therapy improves eating but not drinking skills in children 3–12 years of age. Weight gain is sufficient so that children maintain their growth channel but they do not show catchup growth. Many factors thought to contribute to better ingestive performance need further study, such as jaw and lip control in association with drinking. The earliest possible identification of infants at risk for eating impairments needs to be rigorously pursued. Such an approach offers hope that the later growth deterioration now seen in children with eating impairments may be prevented. Finally, the effect of positioning and the use of eating equipment to promote self-feeding need further study. 相似文献