全文获取类型
收费全文 | 875863篇 |
免费 | 65880篇 |
国内免费 | 1811篇 |
专业分类
耳鼻咽喉 | 12886篇 |
儿科学 | 24799篇 |
妇产科学 | 25208篇 |
基础医学 | 125034篇 |
口腔科学 | 25671篇 |
临床医学 | 76125篇 |
内科学 | 166793篇 |
皮肤病学 | 17165篇 |
神经病学 | 71020篇 |
特种医学 | 35446篇 |
外国民族医学 | 171篇 |
外科学 | 137407篇 |
综合类 | 24726篇 |
现状与发展 | 2篇 |
一般理论 | 290篇 |
预防医学 | 67554篇 |
眼科学 | 20805篇 |
药学 | 65157篇 |
18篇 | |
中国医学 | 1615篇 |
肿瘤学 | 45662篇 |
出版年
2018年 | 7518篇 |
2015年 | 7868篇 |
2014年 | 11289篇 |
2013年 | 17046篇 |
2012年 | 23027篇 |
2011年 | 24189篇 |
2010年 | 14071篇 |
2009年 | 13234篇 |
2008年 | 22893篇 |
2007年 | 24944篇 |
2006年 | 24837篇 |
2005年 | 24449篇 |
2004年 | 23953篇 |
2003年 | 23114篇 |
2002年 | 22145篇 |
2001年 | 35964篇 |
2000年 | 36623篇 |
1999年 | 31038篇 |
1998年 | 9281篇 |
1997年 | 8597篇 |
1996年 | 8525篇 |
1995年 | 8067篇 |
1994年 | 7777篇 |
1992年 | 26793篇 |
1991年 | 26214篇 |
1990年 | 25724篇 |
1989年 | 24787篇 |
1988年 | 23325篇 |
1987年 | 23003篇 |
1986年 | 21854篇 |
1985年 | 21197篇 |
1984年 | 16480篇 |
1983年 | 14053篇 |
1982年 | 8895篇 |
1981年 | 8233篇 |
1980年 | 7704篇 |
1979年 | 16811篇 |
1978年 | 12187篇 |
1977年 | 10232篇 |
1976年 | 9368篇 |
1975年 | 10190篇 |
1974年 | 12703篇 |
1973年 | 12194篇 |
1972年 | 11593篇 |
1971年 | 10739篇 |
1970年 | 10254篇 |
1969年 | 9945篇 |
1968年 | 8945篇 |
1967年 | 8270篇 |
1966年 | 7702篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Zusammenfassung
In 2 F?llen von Wachstumsretardierungen wird die Wertigkeit des Stre?tests (Wehenbelastungstest) analysiert. Unzureichende
Gewichtszunahme, reduzierter Symphysen-Fundus-Abstand und sonographisch nachgewiesene Stagnation des biparietalen Durchmessers
und des Thoraxdurchmessers waren die Indikation zu intensiverer überwachung. Der Stre?test demaskierte die Borderline-Oxygenation
des Feten bevor eine Zentralisation des fetalen Kreislaufs auftreten konnte. 相似文献
992.
993.
A Zejc J Obniska M Wilimowski M Rutkowská M Witkowska J Barczyńska L Kedzierska-Go?dzik W Wojewódzki K Orzechowska-Juzwenko T P?awiak 《Polish journal of pharmacology and pharmacy》1990,42(1):69-77
In reaction of alpha-phenyl, alpha-p-chlorophenyl and alpha-m-chlorophenylsuccinic acid with various aminopyridines, N-pyridyl-substituted succinimides (compounds 1-14) were obtained. These compounds were investigated for their CNS activity. Compounds 1, 2, 5, 6 and 7 displayed anticonvulsant properties in the maximum electroshock test. Compounds 5 and 6 were also active in the pentetrazole test. 相似文献
994.
Interstitial retinoid binding protein (IRBP) is a 136,000 molecular weight photoreceptor cell protein which is a highly pathogenic autoantigen for the induction of experimental autoimmune uveitis (EAU). In this study we produced a series of monoclonal antibodies (MAbs) which define different epitopes in the native molecule. These MAbs were further subdivided into three distinct groups based on a radioimmunoassay, and by ELISA assay using native IRBP and synthetic peptides corresponding to its entire amino acid sequence. Group I MAbs (MAbD7-B1 and MAbC6-B4) bound to native IRBP but not to any synthetic peptides, suggesting that their antigenic epitopes are strictly conformation dependent. Group II MAbs (MAbC7-D3 and MAbG8-H4) bound weakly to multiple peptides which shared amino acid sequence similarity located within each of four homology domains indicating that these epitopes are also conformation dependent. In group III (MAbH3-B5, MAbH7-A5, and MAbB6-D12) MAb binding was localized to a specific peptide. The MAbH3-B5 binding site was further refined to amino acid positions 361 to 367 in the native molecule. MAbH3-B5 was also useful in localizing IRBP in the mouse retina by immunohistochemical techniques. The application of these MAbs in the study of EAU and interphotoreceptor transport mechanisms is discussed. 相似文献
995.
996.
J W Babich F Keeling M A Flower L Repetto A Whitton S Fielding A Fullbrook R J Ott V R McCready 《European journal of nuclear medicine》1988,14(1):39-44
A preliminary study of the distribution of the 99mTc complex of hexamethylpropylene amine oxime (HM-PAO) in 12 patients with brain neoplasms before, during, and after radiotherapy has been performed. Untreated brain tumors were found to exhibit a range of 99mTc-HM-PAO uptake, varying from areas of markedly increased isotope activity to photopenic areas, when compared to normal brain tissue. A ratio of 99mTc-HM-PAO tumor uptake to contralateral normal tissue uptake was calculated prior to and during radiotherapy. This ratio tended to return towards unity in lesions responding to therapy. A predictable alteration in whole brain 99mTc-HM-PAO uptake during radiotherapy was not demonstrated. Unlike the radiolabeled amines, 99mTc-HM-PAO localizes in primary tumors, probably indicating that its uptake mechanism is independent of non specific amine receptors. 99mTc-HM-PAO may be useful in the study of brain tumor physiology and response to therapy. 相似文献
997.
K W Zuurbier A R Bakkenist R H Fokkens N M Nibbering R Wever A O Muijsers 《Biochemical pharmacology》1990,40(8):1801-1808
The chlorinating activity of myeloperoxidase, isolated from human polymorphonuclear neutrophils, was inhibited by the non-steroidal anti-inflammatory drug diclofenac (Voltaren). The concentration of diclofenac needed for 50% inhibition was 20 microM, a value comparable with IC50 values found for other drugs. Diclofenac did not react with HOCl nor with H2O2 but was oxidized in the presence of myeloperoxidase and H2O2 to an orange-coloured unstable product. The rate of oxidation was proportional to the enzyme concentration and to the concentration of diclofenac. but independent of the H2O2 concentration. Presumably both Compound I and Compound II, two intermediates formed during the reaction cycle of myeloperoxidase with H2O2 are able to oxidize diclofenac. In these redox reactions, the active short-living Compound I is reduced to Compound II, thereby inhibiting the chlorinating activity of the enzyme. Analysis by Fast Atom Bombardment mass spectrometry showed that in the presence of H2O2 myeloperoxidase oxidizes diclofenac to dihydroxyazobenzene. 相似文献
998.
999.
RAFAEL BEYAR M.D. D.Sc. ARIEL ROGUIN M.D. JAAP HAMBURGER M.D. RE SAAIMAN M.D. ANTONIO L. BARTORELLI M.D. CARLO DiMARIO M.D. ANTONIO COLOMBO M.D. CHRISTIAN W. HAMM M.D. CHRISTOPHER J. WHITE M.D. J. MARCO M.D. PATRICK W. SERRUYS M.D. Ph.D. 《Journal of interventional cardiology》1997,10(4):277-286
The beStent is a new stainless steel, balloon-expandable mesh stent which has a unique serpentine design. Rotation of the unique low stress junctions upon expansion leads to orthogonal locking of the wires, maximizing radial strength and assuring zero shortening. The stent has delineating gold markers which assure precise positioning. We aim to present the initial acute results in a pilot registry for stent evaluation. Two hundred eighty-four stents were used in a total of 217 patients (age 57.9 ± 3.10 years; 178 males; 39 females) in seven centers, for variable indications. Stents of 15-, 25-, and 35-mm length were used. The arteries treated were the left anterior descending (n = 112, 42%), circumflex (n = 54, 20.2%), right coronary (n = 95, 35.5%), left main (n = 1, 0.4%), and vein graft (n = 5, 1.9%). Lesion types were: A in 42 patients (16.5%); B1 in 53 patients (20.7%); B2 in 81 patients (31.8%); and C in 79 patients (31%). One hundred fifty-nine patients required one stent, 40 patients required two stents, and 18 patients required three or more stents. Anticoagulation protocol included procedural heparin with aspirin with/without ticlopidine. Smooth angiographie results were obtained in all cases with no plaque herniation. Acute angiographic success was obtained in 97% of the patients, and acute clinical success in 95% of the patients. Complications within 30 days were: 3 deaths (1.4%) (2 noncardiac); 2 (0.9%) myocardial infarctions; and 2 (0.9%) stent thromboses. Therefore, the beStent is useful in treatment of complex lesions of variable length and complexity, providing excellent acute results with a low complication rate, in spite of unfavorable basic clinical and angiographie characteristics. 相似文献
1000.