全文获取类型
收费全文 | 646篇 |
免费 | 48篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 7篇 |
妇产科学 | 6篇 |
基础医学 | 84篇 |
口腔科学 | 7篇 |
临床医学 | 44篇 |
内科学 | 91篇 |
皮肤病学 | 5篇 |
神经病学 | 29篇 |
特种医学 | 245篇 |
外科学 | 85篇 |
综合类 | 4篇 |
一般理论 | 2篇 |
预防医学 | 25篇 |
眼科学 | 8篇 |
药学 | 16篇 |
肿瘤学 | 40篇 |
出版年
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 12篇 |
2012年 | 14篇 |
2011年 | 11篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 12篇 |
2007年 | 21篇 |
2006年 | 21篇 |
2005年 | 12篇 |
2004年 | 21篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 16篇 |
1998年 | 20篇 |
1997年 | 22篇 |
1996年 | 19篇 |
1995年 | 15篇 |
1994年 | 22篇 |
1993年 | 20篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 14篇 |
1989年 | 27篇 |
1988年 | 31篇 |
1987年 | 39篇 |
1986年 | 27篇 |
1985年 | 28篇 |
1984年 | 24篇 |
1983年 | 20篇 |
1982年 | 14篇 |
1981年 | 22篇 |
1980年 | 18篇 |
1979年 | 4篇 |
1978年 | 12篇 |
1977年 | 6篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1956年 | 2篇 |
排序方式: 共有700条查询结果,搜索用时 15 毫秒
1.
2.
3.
Normal and diseased isolated lungs: high-resolution CT 总被引:8,自引:0,他引:8
4.
Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease. 总被引:1,自引:0,他引:1
Collins CE Benson MJ Burnham WR Rampton DS 《Alimentary pharmacology & therapeutics》1996,10(3):315-320
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease. 相似文献
5.
6.
W G Simpson M W Vernon B E Maley M E Rush 《Gynecologic and obstetric investigation》1987,24(4):232-240
The relative roles of the cyclic nucleotide messengers cAMP and cGMP in the suppression of follicle-stimulating hormone (FSH) secretion in response to inhibin (IBN) were assessed employing rat gonadotropes in monolayer culture. While exposure of cells to gonadotropin-releasing hormone (GnRH) induced a significant increase in the amounts of both FSH and luteinizing hormone (LH) released into the culture medium, these responses were dampened by the administration of IBN (in porcine follicular fluid). Addition of cGMP to the system failed to restore FSH release, while cAMP restored basal FSH release. Modulation of nucleotide metabolism with theophylline, sodium nitroprusside, and a protein kinase inhibitor failed to overcome the IBN-induced suppression of FSH release. The cellular content of calmodulin increased in response to GnRH, a response antagonized by IBN. Cellular levels of cGMP were also increased by GnRH, but this response was unaltered by IBN. The administered drugs all failed to reverse these effects of IBN. These data indicate that the IBN-induced suppression of FSH release is not dependent upon the cyclic nucleotides cAMP and/or cGMP. However, a role in the maintenance of basal FSH synthesis and release for cAMP is indicated. 相似文献
7.
P M Colombani F G Cigarroa K Schwarz B Wise W E Maley A S Klein 《Annals of surgery》1996,223(6):658-664
OBJECTIVE: The authors report on experience with liver transplantation for infants younger than 1 year of age. SUMMARY BACKGROUND DATA: Over the last 15 years, orthotopic liver transplant has become the only lifesaving procedure available for infants with end-stage liver disease. Many transplant centers initially required infants to reach a specific weight or age to minimize morbidity and mortality. Size-appropriate infant donors also were uncommon. As a result, many children, in the first few years of life, died of their disease. The availability of reduced-size cadaveric and living-related liver transplants has offered the ability to transplant the young infant with liver failure. METHODS: The authors instituted a program to aggressively transplant infants with liver failure in the first year of life using both cadaveric and living-related liver donors. RESULTS: Between June 1991 and January 1995, 13 infants were transplanted for rapidly progressive liver failure. Infant age ranged from 4 to 11 months (mean, 7.5 months). The cause of liver failure included biliary atresia (11), alpha 1-antitrypsin deficiency (1), and liver failure secondary to echovirus 7 (1). The United Network for Organ Sharing status at the time of transplant ranged from status 4, intensive care unit bound (4 patients); status 3, hospitalized (4 patients); or status 2, failing at home (5 patients). Six patients (46%) received cadaveric whole organ (2) or segmental transplants (4). Seven patients (54%) received left lateral segment living-related transplants from parental donors. After operation, patients received cyclosporine or FK506-based immunosuppression. Three patients (23%) required four retransplants (two cadaveric for primary nonfunction; one living-related for graft thrombosis in the face of fungal infection and bile leak). Postoperative complications included primary nonfunction (15%), rejection (85%), graft vascular thrombosis (15%, two of three revascularized successfully), bacterial and fungal infections (77%), and viral infections (46%). Epstein-Barr virus-associated lymphoproliferative developed in two patients (15%). Intestinal perforation requiring reoperation developed in two patients (15%). Bile leaks requiring reoperation or transhepatic stinting or both developed in three patients (23%). Two patients died in the perioperative period (< 1 month) from a combination of primary nonfunction or graft thrombosis and sepsis. Overall survival was 85%, ranging from 11.0 months to 4.5 years. CONCLUSIONS: Orthotopic liver transplantation in infants younger than 1 year of age poses significant challenges from technical and infectious complications. Despite these barriers, overall patient survival is comparable to that of older children and adults. 相似文献
8.
9.
Hydrosalpinges adversely affect markers of endometrial receptivity 总被引:22,自引:10,他引:22
Meyer WR; Castelbaum AJ; Somkuti S; Sagoskin AW; Doyle M; Harris JE; Lessey BA 《Human reproduction (Oxford, England)》1997,12(7):1393-1398
While in-vitro fertilization (IVF) was initially developed in women with
tubal factor infertility, recent clinical studies have suggested that the
presence of hydrosalpinges lowers implantation and pregnancy rates. We
postulated that these hydrosalpinges cause impaired endometrial
receptivity. A total of 103 women with hydrosalpinges were prospectively
evaluated, and compared with 55 infertile and 44 fertile controls. All
women had endometrial biopsies during the window of implantation, analysed
by conventional histological criteria, and also stained for three integrin
markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha
vbeta3). Women with hydrosalpinges (cases) expressed significantly less of
the alpha vbeta3 integrin compared with controls. There was no difference
in expression of alpha1beta1 or alpha4beta1 among groups. A significantly
greater number of cases had out of phase histology and missing alpha vbeta3
(type I defects) and absent integrin expression despite normal histological
maturation (type II) defects, compared with controls. Of 20 women with
impaired endometrial receptivity who were also biopsied after hydrosalpinx
surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven
percent of type I and 57% of type II defects were corrected
postoperatively. Using markers of endometrial receptivity, this study
demonstrates that inflammatory hydrosalpinges have an adverse effect on
endometrial receptivity, which in some cases may be overcome by surgical
treatment of the hydrosalpinx.
相似文献
10.