全文获取类型
收费全文 | 401篇 |
免费 | 13篇 |
国内免费 | 41篇 |
专业分类
儿科学 | 16篇 |
妇产科学 | 1篇 |
基础医学 | 46篇 |
口腔科学 | 8篇 |
临床医学 | 43篇 |
内科学 | 63篇 |
皮肤病学 | 3篇 |
神经病学 | 41篇 |
特种医学 | 66篇 |
外科学 | 117篇 |
综合类 | 17篇 |
预防医学 | 6篇 |
眼科学 | 2篇 |
药学 | 16篇 |
中国医学 | 1篇 |
肿瘤学 | 9篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 18篇 |
2011年 | 20篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 16篇 |
2007年 | 34篇 |
2006年 | 14篇 |
2005年 | 20篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 28篇 |
1996年 | 20篇 |
1995年 | 9篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 16篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 7篇 |
1975年 | 2篇 |
排序方式: 共有455条查询结果,搜索用时 15 毫秒
51.
目的:利用核因子κBp65特异性小干涉核糖核酸抑制肿瘤坏死因子α诱导的关节滑膜细胞中一氧化氮合酶2和环氧合酶2的表达,探讨基因治疗类风湿性关节炎的新方法。方法:实验于2005-03/2006-03在北京大学医学部中心实验室(国家级)完成。①实验材料:清洁级健康近交系SD大鼠10只;一氧化氮合酶2,环氧合酶2,3-磷酸甘油醛脱氢酶引物(由北京奥科生物公司合成);肿瘤坏死因子α(Sigma公司);核因子κBp65特异性小干涉核糖核酸和转染条件由北京大学运动医学研究所陈连旭博士提供。②实验干预:切取大鼠髋关节和膝关节的滑膜体外培养滑膜细胞。利用脂质体siPORTTMLipid将核因子κBp65特异性小干涉核糖核酸转染滑膜细胞,再加入肿瘤坏死因子α刺激。阴性对照为任意编码的小干涉核糖核酸,阳性对照为针对3-磷酸甘油醛脱氢酶的小干涉核糖核酸。③实验评估:提取滑膜细胞中的核蛋白,利用电泳迁移率试验检测核因子κB的活性;提取滑膜细胞的核糖核酸和总蛋白,利用反转录聚合酶链反应和蛋白质免疫印记法从信使核糖核酸和蛋白质两水平检测一氧化氮合酶2和环氧合酶2的表达。结果:①肿瘤坏死因子α和核因子κBp65特异性小干涉核糖核酸对核因子κB转录活性的影响:与正常滑膜细胞相比,肿瘤坏死因子α可以显著提高核因子κB的结合能力,而事先转染小干涉核糖核酸48h,再用肿瘤坏死因子α刺激,核因子κB的结合能力又显著降低。②核因子κBp65特异性小干涉核糖核酸对核因子κB下游因子的影响:在培养的滑膜细胞中,肿瘤坏死因子α可以显著增加一氧化氮合酶2和环氧合酶2的表达;在转染小干涉核糖核酸抑制核因子κBp65的表达后再用肿瘤坏死因子α刺激,一氧化氮合酶2和环氧合酶2的表达被抑制。结论:①核因子κBp65特异性小干涉核糖核酸可降低肿瘤坏死因子α诱导的滑膜细胞中核因子κB的转录活性,抑制其下游因子一氧化氮合酶2和环氧合酶2的表达。②核因子κBp65特异性小干涉核糖核酸可用于基因治疗类风湿性关节炎的试验研究。 相似文献
52.
应用灰关联分析及信息处理方法评价骨质疏松症复方中药治疗的用药规律 总被引:1,自引:0,他引:1
学术背景:中医药在防治骨质疏松症方面具有独特优势,但目前关于该病的中药复方用药规律的研究较少,而且多以统计用药频率为主。此法往往需要大样本且须具有典型的概率分布。此外,在中医诊治过程中,个人经验也造成处方配伍用药的偏倚,药物剂量相距甚远,这使药物治疗的安全性和有效性难以保证。目的:应用灰关联分析及信息处理方法探讨治疗骨质疏松症的用药规律。
检索策略:由第一、三、四作者应用计算机检索中国知网1995-01/2005-12期间的相关文献。所用中文检索词包括“骨质疏松,骨萎,中药,治疗”。共检索到169篇文献。纳入标准:①治疗方法为单纯使用中药治疗,不包括其他辅助治疗,如西药、手法、针灸等。②所有中药复方必须药味完整,剂量准确,主治明确,疗效确切。排除标准:排除含有辅助治疗及疗效不确切,药味不全、没有给出药物剂量或剂量不准确的文献。结果选出104篇符合标准的文章。
文献评价:文献的来源主要是通过对治疗骨质疏松症的中药复方的相关文章进行循证医学系统查询,通过灰关联分析及信息处理方法分析查询结果,以此探讨治疗骨质疏松症的中药复方用药规律。资料综合:在治疗骨质疏松症的104首中药复方中共使用106种药物1204频次。其中,使用频次在10次以上的依次为熟地、淫洋藿、杜仲等34味中药,使用总频次为890次,灰关联系数大小依次为山药、淫羊藿、骨碎补等。性温、平,味甘、苦、辛,归肾经、肝经和脾经的药物所占比例较大。在药物分类中,补益药达到23种,占总数的67.6%。其中,又以补阳药为主,其次为补气药。
结论:灰关联分析及信息处理结果认为骨质疏松症的主要病理是脾肾阳虚,其次为气虚、阴虚和血虚,在用药中主要使用补益肝肾、补脾益气、滋阴活血药。 相似文献
53.
This study was performed to determine the risk of family members of anti-hepatitis C virus (HCV)-positive hemophilia patients (index patients) for infection with HCV compared with the risk of acquiring hepatitis B virus (HBV), human immunodeficiency virus (HIV), and hepatitis A virus (HAV) infection. All index patients (n = 141) were found to be positive by first and second generation anti-HCV enzyme immunoassays (EIAs). Among their household contacts (n = 228), 224 were negative and 1 positive by both assays. Three contacts gave positive results in first generation anti-HCV EIA and negative results in second generation assay. This latter result was confirmed by further tests (neutralization test, synthetic peptides, and supplemental assay). Percent positivity for anti-HBc was about the same in non-sexual household contacts and sexual partners (13 of 109 [12%] and 7 of 54 [13%], respectively). Percent prevalence of anti-HBc was higher in contacts of index patients with chronic hepatitis B than in those of index patients who had recovered from that disease (6 of 20 [30%] and 14 of 133 [10%], respectively; P < .05). The HBV infection rate of contacts participating in controlled self-treatment was not higher than that of controls (3 of 57 [5%] and 10 of 98 [10%], respectively). Of 44 sexual partners, 5 (11%) were found to be positive for anti-HIV. Prevalence of anti-HAV matched with the age-related distribution in the German population. These findings suggest that intrafamilial transmission of HCV to family members of hemophilia patients is uncommon. In contacts of hemophilia patients, the risk of acquiring HBV infection seems to be as high in household contacts as in sexual contacts. Participation in controlled self-treatment does not appear to be an additional risk for HCV and HBV infection. There is no doubt that sexual transmission of HCV is less common than that of HBV and HIV. 相似文献
54.
Arteriovenous malformations of the posterior fossa. Clinical presentation, diagnostic evaluation, and surgical treatment 总被引:2,自引:0,他引:2
Infratentorial arteriovenous malformations (AVM's) represent only 5% to 7% of all AVM's in major series. Since 1977, 32 patients with intracranial intradural malformations of the brain stem or cerebellum have been evaluated at the University of Texas Health Science Center, 30 of whom underwent surgical treatment. Twenty-three patients presented with intracranial hemorrhage, which was recurrent in 11 cases, and nine patients were evaluated for progressive brain-stem or cerebellar deficits. A history of progressive deficits was unusual in the group that presented with hemorrhage, and a prior or subsequent hemorrhage was rare in the patients initially evaluated for progressive deficits. Seventeen of these AVM's were located in the vermis, seven within the cerebellar hemisphere, two in the tonsil, two in the cerebellopontine angle, and four within the brain stem. Operative intervention was directed at primary resection in 15 cases, staged resection in seven, embolization and resection in five, and evacuation of hematoma in three. Operative mortality in this surgical series was 7%, with significant morbidity in 13%. Use of modern microsurgical techniques in removal of posterior fossa AVM's may offer results better than the natural history of the disease process, especially in patients who present with hemorrhage. 相似文献
55.
The risk of carotid endarterectomy in acute cerebral ischemic situations is well documented. By using the superficial temporal or occipital artery, it is possible to provide relatively low flow revascularization conduits, potentially avoiding the risk of postoperative hemorrhage. Eighteen patients at The University of Texas Health Science Center at Dallas, Texas, have been treated recently with extracranial to intracranial bypass in the setting of acute neurological deficit, stroke in evolution, or recent completed infarction. Angiographic causes of these deficits included cervical carotid occlusion in 5 patients, carotid siphon disease in 2 patients, middle cerebral stenosis or occlusion in 3 patients, and delayed cerebral ischemia following subarachnoid hemorrhage in 8 patients. Neurological improvement was demonstrated within 24 hours following revascularization in 15 cases (83%); 3 patients were unchanged following bypass, and no patient's condition was worsened. The only case of postoperative intracerebral hemorrhage occurred 1 week following a long saphenous vein graft from the subclavian to the middle cerebral artery. After an average follow-up of 19 months, 7 patients are neurologically normal, 8 patients have mild to moderate deficits, and 3 patients have died. Low flow revascularization procedures appear to be safe in the setting of acute cerebral ischemia and may in selected patients boost regional cerebral blood flow from levels of symptomatic ischemia into a range compatible with normal neuronal function. 相似文献
56.
57.
Chou HH; Lai YM; Lai CH; Hsueh S; Soong YK 《Human reproduction (Oxford, England)》1997,12(5):1021-1023
A 36 year-old infertile female developed a stage IV (FIGO) ovarian
carcinoma consisting of a poorly differentiated Sertoli-Leydig cell tumour
after receiving one course of ovulation induction with follicle stimulating
hormone (FSH), human menopausal gonadotrophin (HMG) and human chorionic
gonadotrophin (HCG) followed by gonadotrophin-releasing hormone analogue
(GnRHa). The patient died of liver metastasis and hepatic failure 4 1/2
months after first diagnosis, despite aggressive treatment consisting of
debulking surgery and aggressive adjuvant chemotherapy.
相似文献
58.
59.
60.