全文获取类型
收费全文 | 627篇 |
免费 | 40篇 |
国内免费 | 35篇 |
专业分类
儿科学 | 16篇 |
妇产科学 | 1篇 |
基础医学 | 58篇 |
口腔科学 | 25篇 |
临床医学 | 60篇 |
内科学 | 195篇 |
皮肤病学 | 16篇 |
神经病学 | 32篇 |
特种医学 | 118篇 |
外科学 | 32篇 |
综合类 | 28篇 |
预防医学 | 49篇 |
眼科学 | 2篇 |
药学 | 41篇 |
中国医学 | 2篇 |
肿瘤学 | 27篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 18篇 |
2013年 | 23篇 |
2012年 | 20篇 |
2011年 | 21篇 |
2010年 | 19篇 |
2009年 | 21篇 |
2008年 | 23篇 |
2007年 | 33篇 |
2006年 | 22篇 |
2005年 | 29篇 |
2004年 | 13篇 |
2003年 | 15篇 |
2002年 | 24篇 |
2001年 | 22篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 22篇 |
1997年 | 26篇 |
1996年 | 25篇 |
1995年 | 13篇 |
1994年 | 27篇 |
1993年 | 24篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 9篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 13篇 |
1986年 | 6篇 |
1985年 | 14篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有702条查询结果,搜索用时 15 毫秒
1.
A case of a rare anomaly of the common bile duct associated with an abnormal arrangement of the pancreaticobiliary ductal union 总被引:1,自引:0,他引:1
L E Loria K Yamamoto T Eto T Tomioka T Miyamoto N Mochinaga R Tsuchiya 《The Japanese journal of surgery》1988,18(6):718-724
A 39 year-old Japanese female patient with a duplication of the distal portion of the common bile duct is presented herein. Moreover, an abnormal arrangement of the pancreaticobiliary ductal union, congenital biliary dilatation and carcinoma of the gallbladder were all demonstrated by cholangiographic and endoscopical studies. The patient underwent radical surgery for advanced adenosquamous carcinoma of the gallbladder, and her postoperative course was satisfactory. A reflux of pancreatic juice into the bile duct was demonstrated, but it was eliminated and considered to be a contributory etiologic factor of the gallbladder carcinoma. 相似文献
2.
以18-甲基-17β-羟基-17α-乙炔基-雌甾-4-烯-3-酮(18-甲基炔诺酮),17β-羟基-17α-乙缺基-雌甾-4-烯-3-酮(炔诺酮),17β-羟基-17α-乙炔基-雄甾-4-烯-3-酮(妊娠素)和17a-羟基孕甾-4-烯-3,20二酮(17α-羟基黄体酮)为原料,经NaBH,还原、脱水、双键转位和酯化等反应合成一系列3,5-甾二烯化合物,用1HNMR和MS证明了它们的结构。动物筛选结果表明,17β-丙酰氧基-17α-乙炔基-雌甾-3,5-二烯(IVb2有明显的抗早孕活性。中断早期妊娠的作用似与其雌激素活性有关。 相似文献
3.
4.
5.
Androstenediol and dehydroepiandrosterone protect mice against lethal bacterial infections and lipopolysaccharide toxicity 总被引:8,自引:0,他引:8
The protective effects of the hormones androstenediol (androstene-3beta, 17beta,-diol; AED) and dehydroepiandrosterone (5-androsten-3beta-ol-17-one; DHEA) on the pathophysiology of two lethal bacterial infections and endotoxin shock were examined. The infections included a gram-positive organism (Enterococcus faecalis) and a gram-negative organism (Pseudomonas aeruginosa). Both hormones protected mice from the lethal bacterial infections and from lipopolysaccharide (LPS) challenge. Treatment of animals lethally infected with P. aeruginosa with DHEA resulted in a 43% protection whereas treatment with AED gave a 67% protection. Both hormones also protected completely animals infected with an LD50 dose of E. faecalis. Similarly, the 88% mortality rate seen in LPS challenge was reduced to 17% and 8.5%, by treatment with DHEA and AED, respectively. The protective influences of both steroids were shown not to be directly antibacterial, but primarily an indirect antitoxin reaction. DHEA appears to mediate its protective effect by a mechanism that blocks the toxin-induced production of pathophysiological levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1. AED usually had greater protective effects than DHEA; however, the AED effect was independent of TNF-alpha suppression, both in vivo and in vitro. The data suggest that both DHEA and AED may have a role in the neuro-endocrine regulation of antibacterial immune resistance. 相似文献
6.
GD Cramer DJ Allen LJA DiDio W Potvin R Brinker 《Surgical and radiologic anatomy : SRA》1990,12(4):287-290
Summary Accurate volume determination of the encephalic ventricles is of importance in several clinical conditions, including Alzheimer's presenile dementia, schizophrenia, and benign intracranial hypertension. Previous studies have investigated the accuracy with which magnetic resonance imaging (MRI) can be used in clinical practice to evaluate the encephalic ventricles. However, adequate evaluation of pathological conditions depends on a sufficient amount of morphometric data from normal subjects. To begin establishing this data base for normal subjects, we evaluated the MRI scans of 38 subjects found to have no apparent pathology and calculated the ventricular volume in each case by using methods previously developed in our laboratory. The results were then compared with published volumes determined from studies that used either ventricular casts or computerized tomographic scans. The average total ventricular volume for all 38 subjects was 17.4 cm3, while that for males was 16.3 cm3 and that for females was 18.0 cm3. A small but significant correlation was found between age of subject and ventricular volume, with ventricular size increasing with age.
Evaluation du volume des ventricules cérébraux à partir des images obtenues en résonance magnétique nucléaire chez 38 sujets humains
Résumé La détermination exacte du volume des ventricules cérébraux est importante en clinique comme par exemple dans la démence présénile d'Alzheimer, la schizophrénie et l'hypertension intracrânienne bénigne. Des études antérieures ont étudié la fiabilité de la résonance magnétique nucléaire en pratique clinique pour évaluer le volume des ventricules cérébraux. Toutefois une évaluation correcte dans les conditions pathologiques implique une bonne connaissance des données morphométriques du sujet normal. Pour établir ces données sur « le sujet normal », nous avons étudié les coupes obtenues en IRM chez 38 sujets apparemment indemnes de toute pathologie; nous avons calculé le volume ventriculaire dans chaque cas en utilisant des méthodes mises au point auparavant dans notre laboratoire. Les résultats ont été ensuite comparés avec ceux obtenus par d'autres études utilisant soit des moules ventriculaires, soit des coupes tomographiques computérisées. Le volume ventriculaire total moyen chez 38 sujets est de 17,4 cm3, mais il est chez les sujets masculins de 16,3 cm3 et chez les sujets de sexe féminin de 18 cm3. Une corrélation faible mais significative a été trouvée entre l'âge du sujet et le volume ventriculaire, étant entendu que la taille du ventricule augmente avec l'âge.相似文献
7.
8.
W L Kos R M Loria M J Snodgrass D Cohen T G Thorpe A M Kaplan 《Infection and immunity》1979,26(2):658-667
Previous experiments showed that nutritionally induced hypercholesteremia in mice caused an increase in susceptibility to coxsackievirus B, with a marked suppression of cellular infiltrates in infected tissues and an increased mortality. The present studies demonstrated that a hypercholesteremic diet was associated with an inhibition in host resistance as measured by susceptibility to Listeria monocytogenes infection and the growth of two transplanted syngeneic murine tumors. Moreover, the ability of Corynebacterium parvum to induce regression of a transplanted methylcholanthrene-induced fibrosarcoma was inhibited in hypercholesteremic hosts, as was the histiocytic infiltration normally accompanying C. parvum inoculation. In contrast, the peritoneal macrophages from C. parvum-treated hypercholesteremic mice were indistinguishable from similarly treated macrophages from normal mice with respect to their in vitro tumoricidal activity and the presence of a cell surface antigen associated with activated macrophages. Hypercholesteremia was also associated with a decreased antibody response to sheep erythrocytes in vivo, but dit not appear to exert a detrimental effect on B- or T-cell blastogenesis when tested in vitro. The findings that the hypercholesteremic diet was associated with an impairment in the host immune response and increased susceptibility to viral, bacterial, and tumor cell challenge are discussed with respect to virus-lipid interactions in the pathogenesis of atherogenesis and diabetes mellitus. 相似文献
9.
10.
Congenital pulmonary atresia with ventricular septal defect: angiographic and surgical correlates 总被引:1,自引:0,他引:1
Of 181 patients with severe congenital pulmonary atresia and ventricular septal defect or "type IV truncus" (an obsolete term), all but 11% had true central pulmonary arteries. These arteries were demonstrable by large serial biplane angiograms using multiple selective injections into collateral vessels, frequent photographic subtraction, and occasional pulmonary vein-wedge angiograms. These techniques are extremely important for accurate diagnosis and in planning corrective or palliative surgery, which was done in 77% of patients with pulmonary arteries. 相似文献