全文获取类型
收费全文 | 5966篇 |
免费 | 376篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 280篇 |
妇产科学 | 221篇 |
基础医学 | 851篇 |
口腔科学 | 117篇 |
临床医学 | 605篇 |
内科学 | 1299篇 |
皮肤病学 | 196篇 |
神经病学 | 455篇 |
特种医学 | 539篇 |
外科学 | 627篇 |
综合类 | 65篇 |
预防医学 | 272篇 |
眼科学 | 101篇 |
药学 | 376篇 |
2篇 | |
肿瘤学 | 351篇 |
出版年
2022年 | 33篇 |
2021年 | 52篇 |
2020年 | 48篇 |
2019年 | 64篇 |
2018年 | 80篇 |
2017年 | 73篇 |
2016年 | 86篇 |
2015年 | 101篇 |
2014年 | 130篇 |
2013年 | 158篇 |
2012年 | 174篇 |
2011年 | 210篇 |
2010年 | 209篇 |
2009年 | 202篇 |
2008年 | 223篇 |
2007年 | 280篇 |
2006年 | 240篇 |
2005年 | 214篇 |
2004年 | 197篇 |
2003年 | 159篇 |
2002年 | 177篇 |
2001年 | 176篇 |
2000年 | 207篇 |
1999年 | 154篇 |
1998年 | 173篇 |
1997年 | 213篇 |
1996年 | 178篇 |
1995年 | 150篇 |
1994年 | 139篇 |
1993年 | 134篇 |
1992年 | 131篇 |
1991年 | 128篇 |
1990年 | 121篇 |
1989年 | 129篇 |
1988年 | 104篇 |
1987年 | 89篇 |
1986年 | 100篇 |
1985年 | 107篇 |
1984年 | 64篇 |
1983年 | 72篇 |
1982年 | 46篇 |
1981年 | 59篇 |
1980年 | 48篇 |
1979年 | 46篇 |
1978年 | 36篇 |
1977年 | 45篇 |
1976年 | 46篇 |
1975年 | 37篇 |
1973年 | 30篇 |
1972年 | 30篇 |
排序方式: 共有6423条查询结果,搜索用时 15 毫秒
51.
52.
Dysfunction of the blood–cerebrospinal fluid barrier (BCB) has been implicated in the pathogenesis of Parkinson's disease (PD) and other neurodegenerative disorders. Therefore, we assayed serum and cerebrospinal fluid (CSF) from 30 parkinsonian patients and 30 controls for concentrations of albumin and IgG. The CSF/serum ratio for albumin (AQ), IgG (GQ), IgG-index as well as determination of oligoclonal bands were used to evaluate BCB function and to quantify humoral immune response within the central nervous system (CNS). Levels of AQ, GQ and IgG-index did not significantly differ in both groups. We found no dysfunction of the blood–CSF barrier or signs of local synthesis of IgG in the central nervous system of parkinsonian patients. Our data do not support the hypothesis of a dysfunctional BCB that contributes to pathophysiological mechanisms underlying PD. 相似文献
53.
The ability of antigen-specific T-helper (Th) cells to enhance direct plaque-forming cell responses in spleen cells from Trypanosoma cruzi-infected C57BL/6 mice was investigated at various times during the course of infection from day 7 to day 230. The injection of antigen-specific Th cells in vivo or the addition of antigen-specific Th cells in vitro was effective in enhancing direct plaque-forming cell responses, except at the time of the most intense suppression during the acute phase of infection (i.e., day 28). The ability of antigen-specific Th cells to overcome nonspecific immunosuppression was due not only to the activity of antigen-specific Th cells added to Mishel-Dutton cultures but also to activation of resident T cells. Thus, antigen-specific Th cells and resident T cells act in concert to produce enhanced direct plaque-forming cell responses. The effect of plastic-adherent spleen cells from infected mice on the ability of antigen-specific Th cells to stimulate anti-sheep erythrocyte responses of normal spleen cells was examined because macrophages have been shown to have an immunoregulatory role during the course of experimental American trypanosomiasis. Increasing numbers of macrophages from infected mice caused increased immunosuppression of normal spleen cells that could not be overcome with the addition of primed Th cells. It can be concluded from these data that antigen-specific Th cells can potentiate immune responses in mice infected with T. cruzi but that highly active suppressor macrophages can inhibit the expression of these primed Th cells. 相似文献
54.
Urodilatin: a new peptide with beneficial effects in the postoperative therapy of cardiac transplant recipients 总被引:1,自引:0,他引:1
M. Hummel M. Kuhn A. Bub H. Bittner D. Kleefeld P. Marxen B. Schneider R. Hetzer W. G. Forssmann 《Journal of molecular medicine (Berlin, Germany)》1992,70(8):674-682
Summary Renal failure after heart transplantation (HTx) still remains a serious problem, especially when cyclosporin A is used for immunosuppression in the early postoperative therapy. To preserve good renal function without reducing immunosuppressive cyclosporin A treatment, we administered urodilatin (CDD/ANP-95-126) in a long-term, low-dose infusion in addition to the usual medication after heart transplantation. From November 1990 to June 1991, 51 patients (46 male and 5 female; mean age 48 years) were treated with a 620 ng/kg bw·min infusion for 96 h after HTx. The renal function and hemodynamic parameters of these urodilatin-treated patients were compared in this sequential study with 40 patients (33 male and 7 female; mean age 49 years) who had undergone HTx previously from May to November, 1990, as controls. In this phase IIa study, both groups did not differ significantly with respect to age, sex, indication for HTx, and preoperative renal function. In comparison with controls patients treated with urodilatin had a significantly better renal function: a reduction in the peak plasma creatinine (PC values day 4 : 1.5 ± 0.11 vs. 2.19 ± 0.19 mg/dl; P = 0.002), a lower peak serum urea (SU values day 4 : 109 ± 8 vs. 154.7 ± 8.94 mg/dl ; P = 0.0036), and a lower incidence of hemodialysis (6% vs. 10%) were observed. Adequate diuresis was maintained in spite of the reduction of furosemide by more than 60% (P = 0.005) on each day of urodilatin infusion in comparison with controls. The mean central venous pressure was significantly lower by about 50% (P = 0.02) during the administration of urodilatin in spite of reduced vasodilator medication with nitroglycerin. From this phase IIa study, we may conclude that urodilatin could be an important drug in intensive care treatment. For patients undergoing HTx, this peptide seems to be indicated for the improvement of renal function and cardiovascular status, especially in postoperative therapy using high-dose cyclosporin A treatment.Abbreviations ACE
angiotensin converting enzyme
- ANP
atrial natriuretic polypeptide
- ATG
antithymocyte globulin
- bpm
beats per minute
- bw
body weight
- CDD
cardiodilatin
- CDD/ANP-99-126
circulating form of vasorelaxant cardiac peptide
- CHD
coronary heart disease
- CyA
cyclosporin A
- DCM
dilated cardiomyopathy
- GLM
general linear model
- hANP
human atrial natriuretic polypeptide
- HTx
heart transplantation
- NTG
nitroglycerine
- PC
plasma creatinine
- SU
serum urea
- SAS
statistical analysing system 相似文献
55.
56.
Anatomic bases for liver transplantation 总被引:1,自引:0,他引:1
Summary This study gathers the anatomic implications for a good liver transplantation. During hepatic removal a left hepatic a.exists in 20% of cases; a right hepatic artery originating from the superior mesenteric a. (SMA) can be the only arterial supply in 9% of cases; the whole lesser omentum has to be removed and the SMA from 6 cm to its origin. The SMA must be freed from the celiac ganglia and its ostium removed with the celiac trunk in an aortic patch cut on the anterior side in order to avoid the renal ostia. During total hepatectomy, dissection of the portal triad is often difficult because of portal hypertension dilating accessory portal veins (parabiliary arcade) and pedicular lymphatics. Nerve plexuses are thick in front of the hepatic artery or behind the portal triad. Transection of triangular ligaments leads to the retrohepatic inferior vena cava (IVC) that must be freed from its posterior tributaries (right suprarenal vein and inferior phrenic veins flowing either into the IVC or into the hepatic veins). One big problem during hepatic replacement is the biliary anastomosis which must be well irrigated. In the recipient, dissection up to the hilum preserves hepatic and pancreatico-duodenal pedicles. The biliary tract of the graft must be cut low, behind the pancreas, and several centimeters of the gastroduodenal artery must be preserved to save hepatic and gastroduodenal pedicles.
Bases anatomiques de la transplantation hépatique
Résumé Ce travail rassemble les notions anatomiques nécessaires au bon déroulement d'une transplantation hépatique. Le prélèvement du greffon doit enlever tout le petit omentum contenant une éventuelle a. hépatique gauche née de l'a. gastrique gauche (20%) et emporter l'a. mésentérique supérieure jusqu'à 6 cm de son origine pour ne pas oublier une a. hépatique droite née de cette dernière: son ostium est pris avec le tronc clique dans un patch aortique découpé sur la face antérieure. Lors de l'hépatectomie totale, la dissection du pédicule hépatique est rendue délicate par l'hypertension portale qui dilate les veines portes diets accessoires (arcade parabiliaire) et les lymphatiques pédiculaires. Les plexus nerveux sont riches devant l'artère hépatique et derrière le pédicule. La section des ligaments triangulaires droit et gauche amène à la veine cave inférieure (VCI) rétro-hépatique qu'il faut libérer de ses afférences postérieures (en particulier la veine surrénale principale droite toujours haut située et les veines phréniques inférieures qui s'abouchent soit dans la VCI soit dans les veines hépatiques du carrefour). Lors du remplacement, l'anastomose biliaire doit être vascularisée. Chez le receveur la dissection jusqu'au hile permet de conserver les pédicules. La voie biliaire du greffon doit être coupée bas derrière le pancréas et les premiers centimètres de l'artère gastro-duodénale conservés pour préserver les pédicules hépatique et pancréaticoduodénal.相似文献
57.
The ileoanal J pouch: radiographic evaluation 总被引:1,自引:0,他引:1
Endorectal ileoanal pull-through offers an attractive alternative to proctocolectomy and ileostomy for patients with ulcerative colitis, Gardner syndrome, and familial polyposis. To our knowledge, a careful radiographic analysis of the ileum, ileal pouch, and ileoanal anastomosis after ileoanal pull-through has not been reported. Thirty-two patients with ulcerative colitis, Gardner syndrome, and familial polyposis underwent colectomy, mucosal proctectomy, and endorectal ileoanal pull-through of a 15-cm ileal "J" pouch and loop ileostomy. Twenty-five (78%) of 32 of all the pouches radiographically demonstrated spiral folds extending from the middle of the pouch to the pectinate line. Other radiographic features included a mesenteric mass effect, pseudopolyps, and a central lucency that indicated intrapouch sutures. Radiographs provide useful information in the postoperative management of the ileal pull-through. 相似文献
58.
Summary GABA synthesis in skin fibroblasts from patients with Huntington's chorea was compared with that in a control group by means of the highly specific 3H-muscimol radioreceptor assay. A significantly increased rate of GABA synthesis was found in the group with Huntington's chorea in an early cell passage. The possible use of this method for early diagnosis of Huntington's chorea is considered.
Zusammenfassung Die GABA-Synthese in Hautifbroblasten von Chorea Huntington-Patienten im Vergleich zu einer gesunden Kontrollgruppe wurde mittels des hochspezifischen 3H-Muscimol-Radiorezeptoren-Assays untersucht. Wir fanden eine signifikante 8fache Erhöhung der GABA-Synthese bei Chorea Huntington in einer frühen Zellpassage. Es wird erwogen, diese Methode zur Frühdiagnostik von Chorea Huntington einzusetzen.相似文献
59.
Kuhn Josepha van den Berg Pieter Mamede Silvia Zwaan Laura Bindels Patrick van Gog Tamara 《Advances in health sciences education : theory and practice》2022,27(1):189-200
Advances in Health Sciences Education - When physicians do not estimate their diagnostic accuracy correctly, i.e. show inaccurate diagnostic calibration, diagnostic errors or overtesting can occur.... 相似文献
60.
Katrin Gaardbo Kuhn Anne Kathrine Hvass Annette Hartvig Christiansen Steen Ethelberg Susan Alice Cowan 《Emerging infectious diseases》2021,27(4):1133
Campylobacteriosis is a disease of worldwide importance, but aspects of its transmission dynamics, particularly risk factors, are still poorly understood. We used data from a matched case-control study of 4,269 men who have sex with men (MSM) and 26,215 controls, combined with national surveillance data on Campylobacter spp., Salmonella spp., and Shigella spp., to calculate matched odds ratios (mORs) for infection among MSM and controls. MSM had higher odds of Campylobacter (mOR 14, 95% CI 10–21) and Shigella (mOR 74, 95% CI 27–203) infections, but not Salmonella (mOR 0.2, 95% CI 0–13), and were less likely than controls to have acquired Campylobacter infection abroad (χ2 = 21; p<0.001). Our results confirm that sexual contact is a risk factor for campylobacteriosis and also suggest explanations for unique features of Campylobacter epidemiology. These findings provide a baseline for updating infection risk guidelines to the general population. 相似文献