全文获取类型
收费全文 | 5844篇 |
免费 | 489篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 218篇 |
妇产科学 | 149篇 |
基础医学 | 789篇 |
口腔科学 | 287篇 |
临床医学 | 484篇 |
内科学 | 1208篇 |
皮肤病学 | 125篇 |
神经病学 | 520篇 |
特种医学 | 373篇 |
外国民族医学 | 1篇 |
外科学 | 872篇 |
综合类 | 40篇 |
预防医学 | 352篇 |
眼科学 | 55篇 |
药学 | 316篇 |
中国医学 | 10篇 |
肿瘤学 | 504篇 |
出版年
2023年 | 30篇 |
2022年 | 46篇 |
2021年 | 126篇 |
2020年 | 97篇 |
2019年 | 141篇 |
2018年 | 177篇 |
2017年 | 121篇 |
2016年 | 132篇 |
2015年 | 161篇 |
2014年 | 200篇 |
2013年 | 232篇 |
2012年 | 306篇 |
2011年 | 284篇 |
2010年 | 210篇 |
2009年 | 194篇 |
2008年 | 229篇 |
2007年 | 244篇 |
2006年 | 217篇 |
2005年 | 225篇 |
2004年 | 203篇 |
2003年 | 211篇 |
2002年 | 208篇 |
2001年 | 148篇 |
2000年 | 147篇 |
1999年 | 139篇 |
1998年 | 105篇 |
1997年 | 114篇 |
1996年 | 86篇 |
1995年 | 81篇 |
1994年 | 96篇 |
1993年 | 92篇 |
1992年 | 106篇 |
1991年 | 98篇 |
1990年 | 104篇 |
1989年 | 118篇 |
1988年 | 97篇 |
1987年 | 108篇 |
1986年 | 84篇 |
1985年 | 87篇 |
1984年 | 51篇 |
1983年 | 59篇 |
1982年 | 34篇 |
1981年 | 41篇 |
1980年 | 34篇 |
1979年 | 40篇 |
1978年 | 33篇 |
1977年 | 28篇 |
1975年 | 28篇 |
1973年 | 27篇 |
1967年 | 25篇 |
排序方式: 共有6350条查询结果,搜索用时 15 毫秒
61.
62.
Background
Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population. 相似文献63.
Nielsen M Franken PF Reinards TH Weiss MM Wagner A van der Klift H Kloosterman S Houwing-Duistermaat JJ Aalfs CM Ausems MG Bröcker-Vriends AH Gomez Garcia EB Hoogerbrugge N Menko FH Sijmons RH Verhoef S Kuipers EJ Morreau H Breuning MH Tops CM Wijnen JT Vasen HF Fodde R Hes FJ 《Journal of medical genetics》2005,42(9):e54
Objective: To investigate the contribution of MYH associated polyposis coli (MAP) among polyposis families in the Netherlands, and the prevalence of colonic and extracolonic manifestations in MAP patients. Methods: 170 patients with polyposis coli, who previously tested negative for APC mutations, were screened by denaturing gradient gel electrophoresis and direct sequencing to identify MYH germline mutations. Results: Homozygous and compound heterozygous MYH mutations were identified in 40 patients (24%). No difference was found in the percentage of biallelic mutation carriers between patients with 10–99 polyps or 100–1000 polyps (29% in both groups). Colorectal cancer was found in 26 of the 40 patients with MAP (65%) within the age range 21 to 67 years (median 45). Complete endoscopic reports were available for 16 MAP patients and revealed five cases with gastro-duodenal polyps (31%), one of whom also presented with a duodenal carcinoma. Breast cancer occurred in 18% of female MAP patients, significantly more than expected from national statistics (standardised morbidity ratio = 3.75). Conclusions: Polyp numbers in MAP patients were equally associated with the attenuated and classical polyposis coli phenotypes. Two thirds of the MAP patients had colorectal cancer, 95% of whom were older than 35 years, and one third of a subset of patients had upper gastrointestinal lesions. Endoscopic screening of the whole intestine should be carried out every two years for all MAP patients, starting from age 25–30 years. The frequent occurrence of additional extraintestinal manifestations, such as breast cancer among female MAP patients, should be thoroughly investigated. 相似文献
64.
Intestinal immune response of volunteers ingesting a strain of enteroadherent (HEp-2 cell-adherent) Escherichia coli. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Clinical and Vaccine Immunology : CVI》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H F Gomez J J Mathewson P C Johnson H L DuPont 《Clinical and Vaccine Immunology : CVI》1995,2(1):10-13
Enteroadherent Escherichia coli (EAEC) strains identified by adherence to HEp-2 tissue culture cells have been incriminated epidemiologically as important etiologic agents of diarrheal disease in both adult travelers and children in developing countries. One strain, JM 221, with no recognized E. coli virulence characteristics other than adherence to HEp-2 cells, caused diarrhea in 5 of 16 volunteers ingesting it. We studied the secretory immunoglobulin A (sIgA) responses to EAEC JM 221 of five volunteers with diarrhea and five volunteers who remained healthy after challenge. sIgA was extracted from stools obtained prechallenge and 7 days postchallenge. Total sIgA was standardized for all specimens. Specific sIgA titers were determined by dot blotting with the following JM 221 antigens: water-extractable surface antigens, whole cells, lipopolysaccharides, and outer membrane proteins. All five subjects who became ill had fourfold or greater rises in titers against each of the four antigens. The five subjects who remained healthy following challenge did not exhibit significant rises in titers to any JM 221 antigens, but their mean titers were significantly higher than the mean prechallenge titers of the volunteers with diarrhea, suggesting that high intestinal sIgA titers may be protective. The significant increases in intestinal antibody against JM 221 in the subjects who became ill is further evidence of the enteropathogenicity of EAEC strains. 相似文献
65.
JE Robb LA Rymaszewski HB Bentley PT Donnan 《Surgical and radiologic anatomy : SRA》1991,13(3):181-185
Summary This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.
La valeur du sourcil cotyloidien comme repère d'analyse radiologique
Résumé Cette étude, conduite sur 7 bassins secs, apprécie l'effet de l'inclinaison du bassin sur la qualité de l'analyse radiographique de la position d'une cupule prothétique de hanche en utilisant le sourcil cotyloïdien comme repère. Une inclinaison du bassin dans les plans coronal et sagittal est aisément détectable et il n'existe pas de variation d'analyse entre les différents observateurs en dessous de 5° d'inclinaison. De plus, sur 100 radiographies antéro-postérieures de bassin choisies au hasard dans les dossiers de consultation, 90 avaient été réalisées sans incidence particulièrement adaptée et l'on pouvait repérer facilement le sourcil sur 93% d'entre elles. Les mesures faites sur des radios de routine sont donc suffisamment précises pour permettre l'évaluation de la position d'une prothèse à partir du sourcil cotyloïdien.相似文献
66.
Adrenergic mechanisms in cerebral circulation of the goat 总被引:1,自引:0,他引:1
67.
J F Parra R C Fran?a J R Kusel M V Gomez E A Figueiredo T A Mota-Santos 《Molecular and biochemical parasitology》1986,21(2):151-159
The ability of Schistosoma mansoni schistosomula to evade in vitro cytotoxic activity of antibodies plus complement is shown to be increased by incubation with Concanavalin A (Con A) or with non-immune inactivated human serum. This effect was not observed if S-adenosyl-homocysteine (SAH) a methyltransferase inhibitor was added to the incubation medium. Methyl group incorporation occurs in schistosomulum phospholipids if parasites are incubated in Earle's balanced salt solution. This incorporation is increased by Con A addition and this increase is inhibited by SAH. Supernatants of schistosomula incubated in culture media containing Con A were able to promote phospholipid methylation, showing that methyltransferases were liberated into the culture media. The possible roles played by these phenomena in host-parasite interactions are discussed. 相似文献
68.
Tuberous sclerosis complex: neonatal deaths in three of four children of consanguineous, non-expressing parents. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of medical genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M Ruggieri C Carbonara G Magro N Migone S Grasso A Tinè L Pavone M R Gomez 《Journal of medical genetics》1997,34(3):256-260
We describe here four sibs, born to consanguineous, healthy, asymptomatic parents. Three of these infants had a rapidly fatal course in the neonatal period; death was attributed to congestive heart failure with radiographic evidence of cardiomegaly in all of them. Necropsy was done in only one of them and showed the typical findings of tuberous sclerosis complex (TSC) in the central nervous system (CNS), kidneys, heart, and liver. The fourth sib, currently 2 years old, also has typical signs of TSC, namely hypomelanotic skin macules and calcified subependymal nodules. Both parents and a living maternal grandmother had appropriate examination, which included skin inspection under Wood's lamp, dental examination, fundoscopy, echocardiography, abdominal and renal ultrasound, and head CT and MRI scans, and no signs of TSC were found in either parent or in the only living grandmother. By history alone there is no other relative with signs or symptoms suggestive of TSC. Linkage analysis and loss of heterozygosity (LOH) investigations on a variety of lesions obtained from postmortem and tissue or blood specimens from all available family members studied failed to identify a microdeletion in the chromosomal regions where TSC genes are located. It is very unusual that in a single TSC family there were three consecutive neonatal deaths, and very likely that all had cardiac rhabdomyomas. Moreover, to the best of our knowledge, there are no previous reports of TSC families with more than one affected sib, unusually severe manifestations of the disease, and completely normal, consanguineous parents. 相似文献
69.
70.