全文获取类型
收费全文 | 2450篇 |
免费 | 293篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 118篇 |
儿科学 | 157篇 |
妇产科学 | 86篇 |
基础医学 | 278篇 |
口腔科学 | 38篇 |
临床医学 | 296篇 |
内科学 | 541篇 |
皮肤病学 | 49篇 |
神经病学 | 204篇 |
特种医学 | 233篇 |
外科学 | 348篇 |
综合类 | 108篇 |
一般理论 | 5篇 |
预防医学 | 151篇 |
眼科学 | 12篇 |
药学 | 80篇 |
中国医学 | 2篇 |
肿瘤学 | 45篇 |
出版年
2023年 | 19篇 |
2021年 | 36篇 |
2019年 | 31篇 |
2018年 | 56篇 |
2017年 | 36篇 |
2016年 | 36篇 |
2015年 | 34篇 |
2014年 | 78篇 |
2013年 | 87篇 |
2012年 | 83篇 |
2011年 | 118篇 |
2010年 | 84篇 |
2009年 | 85篇 |
2008年 | 90篇 |
2007年 | 85篇 |
2006年 | 87篇 |
2005年 | 68篇 |
2004年 | 64篇 |
2003年 | 44篇 |
2002年 | 56篇 |
2001年 | 69篇 |
2000年 | 82篇 |
1999年 | 40篇 |
1998年 | 43篇 |
1997年 | 38篇 |
1996年 | 33篇 |
1995年 | 40篇 |
1994年 | 32篇 |
1993年 | 35篇 |
1992年 | 80篇 |
1991年 | 75篇 |
1990年 | 69篇 |
1989年 | 81篇 |
1988年 | 67篇 |
1987年 | 53篇 |
1986年 | 60篇 |
1985年 | 72篇 |
1984年 | 58篇 |
1983年 | 23篇 |
1982年 | 23篇 |
1981年 | 18篇 |
1980年 | 27篇 |
1979年 | 43篇 |
1978年 | 21篇 |
1977年 | 18篇 |
1976年 | 22篇 |
1975年 | 23篇 |
1973年 | 28篇 |
1972年 | 22篇 |
1971年 | 25篇 |
排序方式: 共有2751条查询结果,搜索用时 46 毫秒
61.
Toshihiro Nakamura MD Kunihiko Kiuchi MD FHRS Koji Fukuzawa MD Mitsuru Takami MD Yoshiaki Watanabe MD Yu Izawa MD Hideya Suehiro MD Tomomi Akita MD Makoto Takemoto MD Jun Sakai MD Atsusuke Yatomi MD Yusuke Sonoda MD Hiroyuki Takahara MD Kazutaka Nakasone MD Kyoko Yamamoto MD Noriyuki Negi RT Atsushi Kono MD Takashi Ashihara MD PhD Ken-ichi Hirata MD PhD 《Journal of cardiovascular electrophysiology》2021,32(4):1005-1013
62.
63.
I. Dianzani L. Farinasso P. Fortina C. Camaschella R. Ponzone H-H. M. Dahl R. G. H. Cotton A. Ponzone 《Journal of inherited metabolic disease》1989,12(2):162-165
Summary Different mutations of the phenylalanine hydroxylase (PAH) gene leading to phenylketonuria (PKU) have been described associated with specific haplotypes in several European countries. In order to investigate the distribution of DNA haplotypes in Italy, restriction fragment length polymorphism (RFLP) analysis of the PAH gene was performed in nine Italian PKU patients from eight unrelated families, and in the available relatives. The analysis of eight polymorphic sites revealed haplotypes 1 and 6 in association with PKU. This pattern appears to differ from those reported for other European populations.The majority of the 14 PKU subjects studied showed compound heterozygosity for different haplotypes, as observed for other European series.RFLP analysis at the PAH locus allowed us to offer the possibility of prenatal diagnosis to six of the studied families. One prenatal diagnosis was performed and a normal fetus was diagnosed. 相似文献
64.
J F Dowsett D Vaira A R Hatfield S R Cairns A Polydorou R Frost J Croker P B Cotton R C Russell R R Mason 《Gastroenterology》1989,96(4):1180-1186
Between September 1985 and December 1987, 74 patients underwent attempted endoscopic biliary therapy using a combined percutaneous transhepatic and endoscopic transpapillary approach (combined procedure). All patients had had failed endoscopy-alone procedures and had contraindications to surgery. The indication was palliation of malignant biliary obstruction in 66 cases (41 common bile duct, 25 hilar), assistance with sphincterotomy for the removal of common bile duct stones in 6 cases, and management of benign biliary stenosis in 2 cases. The initial procedure was percutaneous transhepatic access to the biliary tree, which was successful in all but 1 case (99%). The bile duct was drained externally for an average of 3.4 days before the combined procedure. One patient died during this period from hemorrhage associated with liver puncture. Combined procedure was performed in 72 cases and was successful in 60 [53 malignant stricture (53/66 = 80%), five common duct stone (5/6 = 83%), two benign stricture (2/2 = 100%)]. Procedure-related morbidity and mortality, respectively, were 12.5% and 0% for benign disease and 36% and 3% for malignant disease. The total (initial endoscopy included) morbidity and 30-day mortality were 33% and 0%, respectively, for benign disease and 62% and 27% for malignant disease. Subsequently, stent change has been required on 16 occasions, with endoscopy-only successful in 13 (81%) and repeat combined procedure being required in three (19%). The combined procedure improves the ability of endoscopy to offer nonsurgical therapy to poor risk patients with both malignant and benign biliary disease but is associated with significant morbidity and disease-related mortality. 相似文献
65.
66.
67.
68.
A. Keshavarzian MD F. L. Iber MD P. Greer RT J. Wobbteton RNNP 《Alcoholism, clinical and experimental research》1986,10(4):432-435
Nausea and vomiting are common complaints in chronic alcoholics. Autonomic neuropathy and esophageal motor abnormalities are frequently observed in chronic alcoholics, but gastric emptying has not been studied in these patients. Gastric emptying of a solid meal was measured, using 99mTc-sulfur colloid cooked in a scrambled egg, in 10 male chronic alcoholics with upper gastrointestinal complaints of nausea and vomiting. All patients were adequately nourished, recently drinking, but just over withdrawal and free of clinical peripheral neuropathy. Gastric emptying in 10 alcoholics was similar to 5 normal controls (t 1/2 115 +/- 12 versus 107 +/- 8 min). These data suggest that upper gastrointestinal symptoms in chronic alcoholics are not related to gastric motor dysfunction. 相似文献
69.
B-chronic lymphocytic leukemia (CLL) patients frequently suffer from moderate to severe hypogammaglobulinemia. This complication is a serious cause of morbidity and mortality in this disorder. There is recent evidence that natural killer (NK) cells modulate B-cell immunoglobin (Ig) synthesis/secretion. The authors therefore evaluated the circulating NK cells from B-CLL patients on their ability to regulate mitogen-induced B-cell Ig synthesis. Blood, NK cells (CD16+, CD3-) from three B-CLL patients with hypogammaglobulinemia were able to clearly down-regulate the pokeweed mitogen (PWM)-induced-B-cell Ig secretion. In contrast, CD16+, CD3- cells from age-sex-matched controls or B-CLL patients with normal Ig were either nonregulatory or enhanced mitogen-induced B-cell Ig secretion. An alternative explanation for hypogammaglobulinemia in B-CLL patients is the immunomodulation of B- cell Ig production/secretion by CD16+, CD3- blood cells. 相似文献
70.
High resolution of heterogeneity among human neutrophil granules: physical, biochemical, and ultrastructural properties of isolated fractions 总被引:4,自引:1,他引:4
Previous studies on the fractionation of human neutrophil granules have identified two major populations: myeloperoxidase (MPO)-containing azurophil, or primary, granules and MPO-deficient specific, or secondary, granules. Peripheral blood neutrophils from individual donors were lysed in sucrose-free media by either hypotonic shock or nitrogen cavitation. Using a novel two-gradient Percoll density centrifugation system, the granule-rich postnuclear supernatant was rapidly (ten minutes) and reproducibly resolved into 13 granule fractions (L1 through L8 and H1 through H5). Granule flotation and recentrifugation experiments on both continuous, self-generated and multiple-step gradients using individual and mixed isolated fractions demonstrated that the banding patterns were isopycnic and nonartifactual. Isolated granules were intact based on the findings that biochemical latency of several granule enzymes was greater than 95%, and thin-sectioned electron micrographs demonstrated intact granule profiles. Biochemical analyses of the granule marker proteins MPO, beta-glucuronidase, lysozyme, and lactoferrin indicated that a number of the fractions were related to the major azurophil and specific granule populations. Lactoferrin was found in ten of 13 fractions (L1 through L8, H1 to H2), whereas MPO was found in every fraction. Consistent with these biochemical data, all fractions exhibited varying degrees of heterogeneity based on ultrastructural morphology and cytochemistry, including diaminobenzidine (DAB) reactivity for peroxidase and periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining for complex glycoconjugates. A variable but significant percentage (23% to 70%) of the granules in fractions L1 through L8 and H1 and H2 showed DAB reactivity, while about 90% of the granules in fractions H3 through H5 were peroxidase positive. These results demonstrated that DAB-reactive granules spanned the entire range of granule size and density. Ultrastructural PA-TCH-SP staining of isolated granule fractions revealed patterns similar to those of granules in intact neutrophils at different stages of development. Granules from human acute promyelocytic leukemia cells (HL-60) exhibited a surprisingly low density compared with typical azurophil granules from normal, mature neutrophils. The data suggest that both functional and maturational differences contribute to granule heterogeneity, and provide a new practical and conceptual framework for further defining the phenomenon of neutrophil granule heterogeneity. 相似文献