全文获取类型
收费全文 | 4904篇 |
免费 | 341篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 130篇 |
妇产科学 | 145篇 |
基础医学 | 765篇 |
口腔科学 | 89篇 |
临床医学 | 654篇 |
内科学 | 860篇 |
皮肤病学 | 87篇 |
神经病学 | 602篇 |
特种医学 | 166篇 |
外科学 | 527篇 |
综合类 | 37篇 |
一般理论 | 4篇 |
预防医学 | 366篇 |
眼科学 | 98篇 |
药学 | 264篇 |
中国医学 | 13篇 |
肿瘤学 | 398篇 |
出版年
2024年 | 7篇 |
2023年 | 42篇 |
2022年 | 64篇 |
2021年 | 161篇 |
2020年 | 95篇 |
2019年 | 134篇 |
2018年 | 155篇 |
2017年 | 117篇 |
2016年 | 141篇 |
2015年 | 170篇 |
2014年 | 212篇 |
2013年 | 235篇 |
2012年 | 359篇 |
2011年 | 373篇 |
2010年 | 259篇 |
2009年 | 202篇 |
2008年 | 304篇 |
2007年 | 337篇 |
2006年 | 288篇 |
2005年 | 282篇 |
2004年 | 266篇 |
2003年 | 225篇 |
2002年 | 273篇 |
2001年 | 53篇 |
2000年 | 41篇 |
1999年 | 48篇 |
1998年 | 46篇 |
1997年 | 40篇 |
1996年 | 31篇 |
1995年 | 37篇 |
1994年 | 30篇 |
1993年 | 18篇 |
1992年 | 15篇 |
1991年 | 18篇 |
1990年 | 14篇 |
1989年 | 17篇 |
1988年 | 15篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1973年 | 8篇 |
1972年 | 8篇 |
1970年 | 6篇 |
1968年 | 7篇 |
排序方式: 共有5282条查询结果,搜索用时 15 毫秒
1.
Rene S. Hendriksen Pimlapas Leekitcharoenphon Matthew Mikoleit Jacob Dyring Jensen Rolf Sommer Kaas Louise Roer Heena B. Joshi Srirat Pornruangmong Chaiwat Pulsrikarn Gladys D. Gonzalez-Aviles E. Ascelijn Reuland Nashwan Al Naiemi Astrid Louise Wester Frank M. Aarestrup Henrik Hasman 《Journal of clinical microbiology》2015,53(2):677-680
One unreported case of extended-spectrum-beta-lactamase (ESBL)-producing Salmonella enterica serovar Typhi was identified, whole-genome sequence typed, among other analyses, and compared to other available genomes of S. Typhi. The reported strain was similar to a previously published strain harboring blaSHV-12 from the Philippines and likely part of an undetected outbreak, the first of ESBL-producing S. Typhi. 相似文献
2.
Astrid Ruiz-Marg in Berenice M Rom n-Calleja Paulina Moreno-Guill n Jos A Gonz lez-Regueiro Deyanira K sulas-Delint Alejandro Campos-Murgu a Nayelli C Flores-Garc a Ricardo Ulises Mac as-Rodr guez 《World journal of gastrointestinal oncology》2021,13(10):1440-1452
Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and presents together with cirrhosis in most cases. In addition to commonly recognized risk factors for HCC development, such as hepatitis B virus/hepatitis C virus infection, age and alcohol/tobacco consumption, there are nutritional risk factors also related to HCC development including high intake of saturated fats derived from red meat, type of cooking (generation of heterocyclic amines) and contamination of foods with aflatoxins. On the contrary, protective nutritional factors include diets rich in fiber, fruits and vegetables, n-3 polyunsaturated fatty acids and coffee. While the patient is being evaluated for staging and treatment of HCC, special attention should be paid to nutritional support, including proper nutritional assessment and therapy by a multidisciplinary team. It must be considered that these patients usually develop HCC on top of long-lasting cirrhosis, and therefore they could present with severe malnutrition. Cirrhosis-related complications should be properly addressed and considered for nutritional care. In addition to traditional methods, functional testing, phase angle and computed tomography scan derived skeletal muscle index-L3 are among the most useful tools for nutritional assessment. Nutritional therapy should be centered on providing enough energy and protein to manage the increased requirements of both cirrhosis and cancer. Supplementation with branched-chain amino acids is also recommended as it improves response to treatment, nutritional status and survival, and finally physical exercise must be encouraged and adapted to individual needs. 相似文献
3.
4.
K Junge U Klinge B Klosterhalfen P R Mertens R Rosch A Schachtrupp F Ulmer V Schumpelick 《Journal of investigative surgery》2002,15(6):319-328
Alterations of the extracellular matrix (ECM) with its major component collagen are increasingly discussed as possible risk factors implicated in the development of abdominal-wall herniation. Because of the widespread use of alloplastic meshes for the surgical repair of hernias, an animal study was performed to analyze the influence of various mesh materials on the quantity and quality of collagen deposition. In 60 male Sprague-Dawley rats an abdominal replacement was performed using three different kinds of mesh materials: polyester (PE), a pure polypropylene (PP), and a composite mesh made of polypropylene and polyglactin (PG). A simple fascia suture repair served as control. The count of fibroblasts, the collagen/protein ratio, the type I/III collagen ratio, and the expression of basic fibroblast growth factor (b-FGF) at the interface were analyzed after 7, 21, and 90 days. The ratio of collagen to overall protein (microg/mg) showed significant differences comparing different mesh materials (sham controls 38.44 +/- 16.33 microg/mg, PE 68.5 +/- 23.8 microg/mg, PP 101.6 +/- 32.3 microg/mg, PG 49.6 +/- 11.6 microg/mg at day 90). The ratio of collagen type I/III increased over time in all groups. However, 90 days after mesh implantation the ratio was always significantly lowered compared to the controls. No significant difference was found comparing different mesh materials. The alteration of the scar composition is closely connected to an increased b-FGF expression. b-FGF and count of fibroblasts highly correlated (r =.95) and showed significant elevated levels compared to simple suture repair. The results of our study strongly support the notion that wound healing is affected by mesh implantation. The quality of the ECM deposition as determined by collagen type I/III ratio is impaired in general, whereas the quantity of ECM deposition is markedly influenced by the kind of mesh material. 相似文献
5.
6.
Early alcoholic liver injury: Activation of lipocytes in acinar zone 3 and correlation to degree of collagen formation in the disse space 总被引:3,自引:0,他引:3
Acinar zone 3 areas in liver biopsy specimens from 23 alcoholics and 47 non-alcoholics were investigated by light microscopy and transmission electron microscopy to asses fibrosis in the perisinusoidal space and to evaluate the role of the lipocytes. Quantitative analysis by light microscopy on toluidine blue-stained sections showed a significant reduction in number of lipocytes--median values of 2.7 and 1.2 lipocytes per 100 hepatocytes in biopsies from chronic alcoholics showing no or varying degrees of zone 3 fibrosis, respectively, as compared to 3.6 lipocytes per 100 hepatocytes in non-alcoholic livers. By transmission electron microscopy, the reduction in number of lipocytes was related to a corresponding increase in number of cells rich in rough endoplasmic reticulum and microfilaments (activated lipocytes). The occurrence of activated cells was significantly correlated to fibrosis of the perisinusoidal space. Activation of lipocytes and collagenization of the perisinusoidal space appeared before light microscopic evidence of fibrosis and were topographically not related to Mallory bodies or alcoholic hepatitis. 相似文献
7.
Genetic predisposition for adult lactose intolerance and relation to diet, bone density, and bone fractures. 总被引:8,自引:0,他引:8
Barbara M Obermayer-Pietsch Christine M Bonelli Daniela E Walter Regina J Kuhn Astrid Fahrleitner-Pammer Andrea Berghold Walter Goessler Vinzenz Stepan Harald Dobnig Georg Leb Wilfried Renner 《Journal of bone and mineral research》2004,19(1):42-47
Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. INTRODUCTION: Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. MATERIALS AND METHODS: We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. RESULTS: Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. CONCLUSION: The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose malabsorption and osteoporosis. 相似文献
8.
9.
10.