全文获取类型
收费全文 | 125955篇 |
免费 | 10885篇 |
国内免费 | 8146篇 |
专业分类
耳鼻咽喉 | 1019篇 |
儿科学 | 1561篇 |
妇产科学 | 2322篇 |
基础医学 | 14802篇 |
口腔科学 | 2059篇 |
临床医学 | 16402篇 |
内科学 | 20669篇 |
皮肤病学 | 1448篇 |
神经病学 | 6874篇 |
特种医学 | 4296篇 |
外国民族医学 | 70篇 |
外科学 | 13092篇 |
综合类 | 18905篇 |
现状与发展 | 24篇 |
一般理论 | 5篇 |
预防医学 | 7819篇 |
眼科学 | 3651篇 |
药学 | 12778篇 |
115篇 | |
中国医学 | 6039篇 |
肿瘤学 | 11036篇 |
出版年
2024年 | 345篇 |
2023年 | 1822篇 |
2022年 | 4659篇 |
2021年 | 5862篇 |
2020年 | 4222篇 |
2019年 | 4061篇 |
2018年 | 4128篇 |
2017年 | 3690篇 |
2016年 | 3460篇 |
2015年 | 5213篇 |
2014年 | 6533篇 |
2013年 | 6090篇 |
2012年 | 8900篇 |
2011年 | 9758篇 |
2010年 | 5945篇 |
2009年 | 4735篇 |
2008年 | 6506篇 |
2007年 | 6496篇 |
2006年 | 6538篇 |
2005年 | 6478篇 |
2004年 | 4458篇 |
2003年 | 4211篇 |
2002年 | 3560篇 |
2001年 | 3225篇 |
2000年 | 3309篇 |
1999年 | 3454篇 |
1998年 | 2243篇 |
1997年 | 2168篇 |
1996年 | 1564篇 |
1995年 | 1457篇 |
1994年 | 1266篇 |
1993年 | 819篇 |
1992年 | 1227篇 |
1991年 | 1075篇 |
1990年 | 931篇 |
1989年 | 823篇 |
1988年 | 712篇 |
1987年 | 668篇 |
1986年 | 508篇 |
1985年 | 463篇 |
1984年 | 249篇 |
1983年 | 178篇 |
1982年 | 118篇 |
1981年 | 116篇 |
1980年 | 76篇 |
1979年 | 120篇 |
1978年 | 59篇 |
1976年 | 52篇 |
1975年 | 55篇 |
1974年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
老年充血性心衰患者地高辛药代动力学研究 总被引:3,自引:0,他引:3
目的 :探讨老年心衰患者地高辛维持量的合理应用。 方法 :用荧光偏振免疫分析法测定了 14例老年心衰患者血清地高辛浓度 ,并计算出药代动力学参数。 结果 :14例老年心衰患者地高辛 t1/ 2 β,β和 Vd分别为 72 .769± 2 9.768h、0 .0 11± 0 .0 0 6h-1和 3.190± 3.30 0 L/ kg,与非老年心衰患者 ( t1/ 2 β 36.1± 2 .0 h,56.3± 12 h,β 0 .0 19± 0 .0 0 1h-1,Vd 7.37± 1.65L / kg)相比差异显著。 结论 :老年心衰患者地高辛维持量以小量分次给药为宜 ,且更应注意个体化 相似文献
122.
123.
Regulatory properties of brain glutamate decarboxylase (GAD): the apoenzyme of GAD is present principally as the smaller of two molecular forms of GAD in brain 总被引:10,自引:0,他引:10
The apoenzyme of glutamate decarboxylase [enzyme without bound cofactor, pyridoxal 5'-phosphate (pyridoxal-P)] serves as a reservoir of inactive glutamate decarboxylase (GAD) that can be activated when additional GABA synthesis is required. We have investigated which of two molecular forms of GAD is present as apoenzyme in synaptosomes and in cortex, caudate nucleus, hippocampus, and cerebellum of rat brain. Endogenous glutamate apodecarboxylase (apoGAD) was labeled by incubating extracts of synaptosomes or punches of each region with 32P-pyridoxal-P, followed by reduction with NaBH4, to link covalently the 32P-pyridoxal-P to GAD. Proteins were separated by SDS-PAGE. Punches from all four brain regions and forebrain synaptosomes contained two forms of GAD with apparent Mrs of 63 and 65 kDa as identified by immunoblotting with four antiGAD sera. Punches and synaptosomes contained a major 32P-pyridoxal-P-labeled band with an apparent Mr of 63 kDa that was stained on immunoblots by the antiGAD serum 1440 and the monoclonal antibody GAD-6, and a minor labeled band at 65 kDa that was stained by the 1440, 6799, and K2 antisera. Synaptosomes contained remarkably few other strongly labeled proteins, but punches contained several other labeled bands. Three additional lines of evidence indicate that the labeled 63-kDa protein is apoGAD: (1) it was purified by immunoaffinity chromatography with the GAD-1 monoclonal antibody; (2) it yielded one major labeled peptide when digested with chymotrypsin, and that peptide appeared identical in peptide-mapping experiments to the labeled active-site peptide isolated from chromatographically prepared rat brain GAD; and (3) its labeling was selectively blocked by 4-deoxypyridoxine 5'-phosphate, a competitive inhibitor of the binding of pyridoxal-P to GAD.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
124.
125.
The efficacy of radiology in evaluating dysphagia was studied in 86 patients by comparison to endoscopic findings. In the 66 patients with endoscopic abnormalities radiology was correct in 54, for a sensitivity of 82%. Sensitivity of radiology improved to 95% if mild esophagitis was excluded. In the 20 patients with normal endoscopy, radiology was normal in 18 (90%). Thus radiology proved to be a reliable means of evaluating the esophagus in patients with dysphagia. 相似文献
126.
Detection of cell apoptosis by MTT assay.] 总被引:1,自引:0,他引:1
Chun-Qiong Feng Wen-Li Ma Yan-Bing Song Qiu-Ye Guo Qing-Hua Wu Wen-Ling Zheng 《第一军医大学学报》2002,22(3):262-263
OBJECTIVE: To study the feasibility of using MTT assay to detect cell apoptosis. METHODS: K562 cells were grown in RPMI 1640 medium supplemented with 10% calf serum and 4 micromol/L arsenic trioxide. Apoptosis was induced in the cultured cells by As2O3, and the cells were detected with optical microscope, DNA gel electrophoresis and MTT staining respectively. RESULT: MTT staining could also accurately detect cell apoptosis, by which the apoptotic cells were easily distinguished from normal cells and dead cells. CONCLUSION: MTT staining is simple, convenient and practical for detecting cell apoptosis. 相似文献
127.
ELISA法检测可溶性人类白细胞抗原—I及广东人参考值的测定 总被引:3,自引:0,他引:3
OBJECTIVE: To explore a method for quantitative detection of soluble human leukocyte antigen class I(HLA-I) antigens, with the assistance of which we attempt to define the reference value of the antigen in the population of Guangdong Province. METHODS: Sandwich enzyme-linked immunosorbent assay (ELISA) was employed with W6/32 monoclonal antibody serving as the solid phase antibody and beta2 microglobulin antibody as the first antibody. HRP-labeled second antibody and the substrate were added for enzyme-catalyzed coloring. On the basis of the standard curve obtained by sHLA-I standard reagent in serial dilution, the concentration of sHLA-I antigens in the samples of 60 normal subjects from the population of Guangdong province was detected. RESULTS: The sensitivity of this assay was 2.84 ng/ml with variation coefficients of 5.80% within the same batch and 9.00% between batches. The recovery rate ranged from 98.57% to 100.15%. The level of sHLA-I antigens in normal individuals was 699.54+/-360.10 ng/ml. CONCLUSION: Sandwich ELISA is sensitive, specific and stable in the detection of sHLA-I. 相似文献
128.
Meng-Luen Lee Lon-Yen Tsao Wun-Tsong Chaou Albert D Yang Kun-Tu Yeh Jou-Kou Wang Mei-Hwan Wu Hung-Chi Lue Ing-Sh Chiu Chung-I Chang 《Pediatric pulmonology》2002,33(1):1-11
We propose a haphazard branching theory to support the concept of bronchopulmonary malinosculations, and we apply this theory to classify congenital bronchopulmonary vascular malformation (BPVM) based on the anatomical results we have found. Between January 1990 and December 1997, a total of 22 pediatric patients (10 male and 12 female), aged 2 days to 14 years (median, 19.6 months), with congenital BPVM were enrolled in this retrospective study. Study modalities include the clinical features and plain chest films (n = 22) plus at least two of the following: echocardiography (n = 13), barium esophagraphy (n = 2), bronchoscopy (n = 4), contrast bronchography (n = 8), high-resolution direct coronal CT (n = 1) and electron beam or ultrafast CT (n = 1) of the chest, MRI (n = 10), MRA (n = 1), contrast cineangiocardiography (n = 9), surgery (n = 11), or autopsy (n = 2). The salient clinical features were recurrent lung infections in 14 patients, acute respiratory distress in 13, associated cardiovascular malformations in 8, dextroversion in 7, congestive heart failure in 7, dextrocardia in 4, and complex congenital heart diseases in 4. There were abnormal openings (malinosculations) of the pulmonary airway in 20 patients: to an artery in 12, to a vein in 8, and to the lung parenchyma in 9. These 22 patients with congenital BPVM can be classified into bronchial malinosculation (10 cases), arterial malinosculation (2 cases), and bronchoarterial malinosculation (10 cases). Congenital BPVM can be classified in terms of bronchopulmonary malinosculation based upon a haphazard branching theory, in which abnormal communications between two independent systems (primitive foregut system and aortic-pulmonary arch system) occurred coincidentally rather than causally. 相似文献
129.
目的 :提高妊娠合并柯兴氏综合征的诊治水平。方法 :结合国内外文献 16例 ,分析讨论妊娠与柯兴氏综合征的相互影响所导致的各种临床结局。结果 :肾上腺皮质腺瘤位于妊娠合并柯兴氏综合征的病因首位 ,而高肾上腺皮质激素刺激征和特征性腹部、大腿宽大紫纹 ,结合B超、CT可以诊断妊娠合并柯兴氏综合征 ;严重的并发症威胁母婴安全 ,积极进行手术治疗和并发症的处理可以降低母婴死亡率、延长孕周。结论 :妊娠合并柯兴氏综合征是极度的高危妊娠 ,妊娠期的早期诊断、早期治疗能改善妊娠质量。 相似文献
130.
中南邵阳、华东南京、西南成都组织胞浆菌感染流行病学调查 总被引:5,自引:0,他引:5
目的 :组织胞浆菌是一种真菌 ,由家禽及鸟类传播 ,可引起人的深部真菌病。我们进行的流调工作 ,对掌握疾病流行情况、制定防治措施及对结核病的防治工作具有重要意义。方法 :调查对象是健康人、住院的肺结核病人、住院的非结核性肺疾患病人。使用的方法是在前臂内侧皮内注射酵母相组织胞浆菌素 (Histolyn -CYL)。同时在另一前臂做PPD皮试 (1∶1万 )。结果 :中南邵阳地区健康人组织胞浆菌素皮试阳性率2 2 .4 0 %。肺结核病人阳性率 31.6 0 %。非结核病肺部疾病阳性率 15 .85 %。华东南京地区健康人阳性率15 .10 %。肺结核病等阳性率 17.74 %。西南成都地区健康人阳性率 2 1.77%。肺结核病人阳性率 5 4 .4 4 %。结论 :组织胞浆菌感染率很高 ,与人文地理条件密切相关 ,差异很大。因此制订防治措施也应有所不同 ,应结合当地具体情况。 相似文献