全文获取类型
收费全文 | 47569篇 |
免费 | 3544篇 |
国内免费 | 1968篇 |
专业分类
耳鼻咽喉 | 168篇 |
儿科学 | 831篇 |
妇产科学 | 491篇 |
基础医学 | 6879篇 |
口腔科学 | 511篇 |
临床医学 | 3713篇 |
内科学 | 13435篇 |
皮肤病学 | 646篇 |
神经病学 | 3174篇 |
特种医学 | 910篇 |
外国民族医学 | 2篇 |
外科学 | 3705篇 |
综合类 | 5219篇 |
现状与发展 | 5篇 |
预防医学 | 2840篇 |
眼科学 | 881篇 |
药学 | 6150篇 |
7篇 | |
中国医学 | 1530篇 |
肿瘤学 | 1984篇 |
出版年
2023年 | 471篇 |
2022年 | 911篇 |
2021年 | 1181篇 |
2020年 | 1166篇 |
2019年 | 1832篇 |
2018年 | 1803篇 |
2017年 | 1620篇 |
2016年 | 1595篇 |
2015年 | 1754篇 |
2014年 | 2867篇 |
2013年 | 3320篇 |
2012年 | 2621篇 |
2011年 | 2915篇 |
2010年 | 2189篇 |
2009年 | 2121篇 |
2008年 | 2100篇 |
2007年 | 2309篇 |
2006年 | 2030篇 |
2005年 | 1783篇 |
2004年 | 1568篇 |
2003年 | 1448篇 |
2002年 | 1223篇 |
2001年 | 1096篇 |
2000年 | 932篇 |
1999年 | 844篇 |
1998年 | 722篇 |
1997年 | 774篇 |
1996年 | 582篇 |
1995年 | 580篇 |
1994年 | 502篇 |
1993年 | 380篇 |
1992年 | 336篇 |
1991年 | 261篇 |
1990年 | 201篇 |
1989年 | 179篇 |
1988年 | 150篇 |
1987年 | 131篇 |
1985年 | 466篇 |
1984年 | 566篇 |
1983年 | 454篇 |
1982年 | 418篇 |
1981年 | 406篇 |
1980年 | 363篇 |
1979年 | 324篇 |
1978年 | 276篇 |
1977年 | 208篇 |
1976年 | 247篇 |
1975年 | 250篇 |
1974年 | 196篇 |
1973年 | 174篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
O. F. M. SELLEVOLD T. M. BERG K. A. REIN O. W. LEVANG O–J. IVERSEN K. BERGH 《Acta anaesthesiologica Scandinavica》1994,38(4):372-379
A prospective randomized study was performed to investigate the effect of surface coating with covalently endpoint–attached heparin (Carmeda Bio Active Surface) and reduced general heparinization on haematological indices and complement C5 activation. Care was taken to optimize the rheological design of the system using centrifugal pump and a closed system without venting or machine suction. Twenty patients scheduled for aortocoronary bypass grafting (EF > 0.5) participated in the study. Ten patients were randomized to be treated with heparin–coated equipment (CBAS) and reduced i.v. heparin (1.5 mg kg-1) while 10 patients treated with identical but noncoated equipment and full heparinization (3 mg–kg-1) served in a Control group. A vacuum suction was used to collect the blood from the operating field and it was autotransfused at weaning from extracorporeal circulation (ECC). Blood samples were obtained from the venous (precircuit) and arterial (postcircuit) side. We used a new and very specific method for detection of C5a based on monoclonal antibodies. The concentration of C5a was low in both groups during the operation but a significant increase was seen on days 1 and 2. In the Control group there was an increase from 10.2 ngml-1±1.2 to 27.5 ng ml-1 ± 4.8 on day 2 and in the CBAS group from 10.7 ng ml-1 ± 1.2 to 35.6 ng ml-1 ± 11.6 on day 2 (NS between groups). The granulocytes and total leukocyte count increased at the end of ECC and was maintained at the elevated level throughout the study period. The amount of free haemoglobin was high in the autotransfused blood in both groups. The present results confirm the feasibility of reducing general heparin when using heparin–coated systems but the study does not support the superiority of such coating with regard to biocompatibility in short procedures with a Theologically optimized circuit. The potential benefit from reduced heparin and protamine has not been fully evaluated. 相似文献
33.
Masanori Hara M.D. Reiko Yoshida M.D. Susumu Inaba M.D. Akira Higuchi M.D. Yoshifumi Suzuki M.D. Toshio Okada M.D. Takakuni Tanizawa M.D. 《Pediatrics international》1991,33(3):335-344
The aim of this study was to assess the significance of C3 deposition in IgA nephropathy in children and adolescents. One hundred and two patients aged 5–21 years (57 male and 45 female) were studied. The findings of C3 deposition were classified into 8 groups by immunofluorescent (IF) pattern and intensity as follows: group MC3+ (N = 12): mesangiocapillary pattern and 3+ in intensity; group MC2+ (N = 13): mesangiocapillary and 2+; group MC1 + (N = 4): mesangiocapillary and 1 +; group M3+ (N = 11): mesangial and 3+; group M2+ (N = 24): mesangial and 2+; group M1 + (N=18): mesangial 1 +; group S (N = 12): only segmentally positive; and group N (N = 8): negative. Histological changes were scored semiquantitatively as an activity index (cellular proliferation, necrosis, interstitial cell infiltration, and cellular crescents) and a chronicity index (mesangial sclerosis, segmental and global glomerular sclerosis, fibrous crescents, adhesion and tubulo-interstitial change). IF findings were scored semiquantitatively and laboratory findings were also studied. The following results were obtained: 1) The scores of total activity index in MC groups were higher than in the M, S or N groups, and the greater the degree of C3 deposition, the higher the score; 2) Such result was not evident in the chronicity index; 3) High IF scores of IgG and IgM were found in the MC3+ and MC2+ groups; 4) Hematuria was more severe in MC3+ and MC2+ than in other groups, and proteinuria was more prominent in the MC than other groups. Thus the degree of C3 deposition was parallel with histological activity and urinary findings. 相似文献
34.
S. Leskinen-Kallio 《Clinical physiology and functional imaging》1994,14(3):329-335
Summary. The particular advantages of positron emission tomography (PET) technique are that it has higher sensitivity, higher resolution, and a higher quality of image than that found in conventional nuclear medicine. The possibility of quantification and the wide range of useful tracers have raised expectations of this new method. To date, most of the human PET cancer studies have been performed with [18F]fluorodeoxyglucose (FDG) or [11CJmethionine. These are good imaging agents for tumours. However, more specific radiopharmaceuticals are required if other features of tumour metabolism are to be observed, f11Thymidine may prove to be a good tracer for quantitative measurements of tumour proliferation and [18F]misonidazole has been suggested for imaging of hypoxia. 相似文献
35.
谢林 《湖南中医药大学学报》1994,14(2):1-3
本文从髌骨软骨软化症的病因病理出发,阐述了活血化瘀疗法治疗髌骨软骨软化症的作用及其原理,列举了活血化瘀法在该病治疗中的具体运用,同时强调了在辨证施治基础上活血化瘀的重要性。 相似文献
36.
37.
HCVRNA阳性的丙型肝炎46例,均经临床和/或组织学确诊。治疗组24例用IFNa-nl或a-2b3×106IU,隔日一次;对照组22例用一般护肝药物。HCVRNA12周转阴率治疗组为83.3%,对照组为9.0%(P<0.001)。ALT和AST复常率治疗组也优于对照组(P<0.05)。随访观察满48周者治疗组15例中HCVRNA持续转阴11例(73.3%).对照组5例均持续阳性。治疗组中5例做了Ⅰ~Ⅲ型HCV基因分型,结果均为Ⅱ型。同时对急、慢性丙型肝炎的发病过程和病理诊断作了讨论。 相似文献
38.
39.
正常人及胃癌患者胃蛋白酶原C基因多态性研究 总被引:2,自引:0,他引:2
以PGC301为探讨,对10例胃癌组织及11例正常人体组织基因组DNA中胃蛋白酶原C基因的EcoR I限制性片段长度多态性作了观察分析。发现在正常人体有三种常见等位片段,分别为20kb、5.7kb及3.6kb;一种稀有片段,3.5kb。在胃癌患者,未发现与正常人体不同的等位片段。但是,稀有片段及稀有杂交带型的出现频率高于正常组。这一结果对深入探讨胃蛋白酶原C基因稀有片段及稀有杂交带型对胃癌的诊断价 相似文献
40.
利用气相色谱—质谱—计算机联用仪分析了云南省腾冲县产珠子参挥发油的成份,从中鉴定了27种化合物,测定了它们的相对含量,其中有10种倍半萜烯和一种倍半萜醇。 相似文献