全文获取类型
收费全文 | 21827篇 |
免费 | 1039篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 253篇 |
儿科学 | 375篇 |
妇产科学 | 322篇 |
基础医学 | 3244篇 |
口腔科学 | 354篇 |
临床医学 | 1939篇 |
内科学 | 4125篇 |
皮肤病学 | 779篇 |
神经病学 | 2711篇 |
特种医学 | 1195篇 |
外科学 | 2723篇 |
综合类 | 151篇 |
一般理论 | 6篇 |
预防医学 | 929篇 |
眼科学 | 505篇 |
药学 | 1736篇 |
中国医学 | 28篇 |
肿瘤学 | 1659篇 |
出版年
2023年 | 80篇 |
2022年 | 133篇 |
2021年 | 275篇 |
2020年 | 232篇 |
2019年 | 278篇 |
2018年 | 374篇 |
2017年 | 296篇 |
2016年 | 420篇 |
2015年 | 465篇 |
2014年 | 655篇 |
2013年 | 815篇 |
2012年 | 1286篇 |
2011年 | 1368篇 |
2010年 | 783篇 |
2009年 | 789篇 |
2008年 | 1430篇 |
2007年 | 1477篇 |
2006年 | 1551篇 |
2005年 | 1573篇 |
2004年 | 1444篇 |
2003年 | 1483篇 |
2002年 | 1387篇 |
2001年 | 262篇 |
2000年 | 214篇 |
1999年 | 290篇 |
1998年 | 326篇 |
1997年 | 269篇 |
1996年 | 212篇 |
1995年 | 175篇 |
1994年 | 196篇 |
1993年 | 149篇 |
1992年 | 102篇 |
1991年 | 120篇 |
1990年 | 113篇 |
1989年 | 100篇 |
1988年 | 102篇 |
1987年 | 63篇 |
1986年 | 66篇 |
1985年 | 76篇 |
1984年 | 87篇 |
1983年 | 78篇 |
1982年 | 81篇 |
1981年 | 94篇 |
1980年 | 72篇 |
1979年 | 65篇 |
1977年 | 61篇 |
1976年 | 64篇 |
1974年 | 58篇 |
1955年 | 48篇 |
1954年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
21.
Bernd Huber Ines Hauser Verena Horstmann Gabi Jokeit Sylvia Liem Theodor May Thomas Meinert Enrique Robertson Heide Schorlemmer Wolfgang Wagner Michael Seidel 《Seizure》2007,16(1):35-42
This study was designed to describe the course of epilepsy (in terms of seizure frequency) and to assess the variables (antiepileptic therapy regimens and others) correlated to improvement. Seizure frequency (categories: seizure free, more than one seizure/year, monthly seizures, weekly seizures and daily seizures) and antiepileptic medication were retrospectively compared between 1992 and 2002 in a large cohort of 550 inpatients with chronic epilepsy and different degrees of intellectual disability or multiple handicaps. RESULTS: Seizure frequency decreased significantly (p<0.001). 218 of the 394 patients (55.3%) not seizure free in 1992 improved (changed into a better frequency category). The improvement rate was marginally higher in patients who had undergone a medication change (p=0.08). A high seizure frequency in 1992 (p=0.016) and older age (p=0.006), but not epilepsy syndrome or degree of intellectual disability, were predictors for improvement (stepwise logistic regression analysis). 56.4% of the improved patients were on combinations of two AEDs (17.4%, monotherapy; 20.2%, triple therapy). The most frequent therapy regimens in the improved patients were lamotrigine/valproate (48 patients), carbamazepine/phenobarbital (21) and carbamazepine only (19). Lamotrigine/valproate was effective in all kinds of epileptic syndromes. Most patients on lamotrigine had serum concentrations above 10microg/ml, approximately one half had dosages above 200mg/day. The rate of seizure freedom increased from 28.4 to 37.6%. The 84% of the patients seizure free in 1992 remained seizure free. Predictors for seizure freedom in 2002 were higher age (stepwise logistic regression, p<0.0005) and seizure freedom in 1992 (p<0.0005). CONCLUSIONS: Substantial improvement can be achieved even in intellectually disabled patients with chronic epilepsy. Although the rate of seizure freedom is reduced in comparison with a non-ID population, once seizure freedom has been achieved it is most likely to continue. For a majority of this patient population, monotherapy may not be sufficient. Lamotrigine/valproate appears to be a major therapeutic innovation. 相似文献
22.
Wolfgang Spiegel 《The American journal of geriatric psychiatry》2007,15(8):726-7; author reply 727
23.
Walter S Speidl Markus Exner Jasmin Amighi Wolfgang Mlekusch Schila Sabeti Stefan P Kastl Gerlinde Zorn Gerald Maurer Oswald Wagner Kurt Huber Erich Minar Johann Wojta Martin Schillinger 《Journal of endovascular therapy》2007,14(1):62-69
PURPOSE: To investigate whether balloon angioplasty of the superficial femoral artery (SFA) increases serum levels of C5a and whether C5a predicts risk of restenosis. METHODS: C5a antigen was measured at baseline and 8 hours after intervention in 131 consecutive patients (76 women; median age 72 years) with intermittent claudication who underwent successful primary SFA balloon angioplasty. Patients were followed for a median 10 months [interquartile range (IQR) 6 to 14] for the occurrence of >50% restenosis by duplex ultrasound. RESULTS: Median C5a levels increased significantly from 39.7 ng/mL (IQR 27.8 to 55.0) at baseline to 53.8 ng/mL (IQR 35.6 to 85.1, p<0.001) 8 hours post intervention. During the follow-up period, 70 (53%) patients developed restenosis. Increasing levels of C5a (quartiles) at baseline were significantly associated with an increased risk for restenosis (p=0.0092). Adjusted hazard ratios (95% confidence intervals) for restenosis with increasing quartiles of baseline serum C5a levels were 1.24 (0.60 to 2.58), 1.93 (0.95 to 3.93), and 2.08 (1.02 to 4.21), respectively, compared to the lowest quartile. This effect was independent of nonspecific inflammation as reflected by plasma levels of C-reactive protein. CONCLUSION: Inflammatory mechanisms play a major role in the development of restenosis after angioplasty. The complement component C5a exerts strong chemotactic and proinflammatory effects. Enhanced complement activation prior to PTA, as measured by higher levels of C5a, was significantly associated with restenosis after SFA balloon angioplasty. Pathways of complement inhibition thus may be worth investigating with respect to improving patency rates. 相似文献
24.
25.
Ayman Agha Gabriel Glockzin Matthias Woenckhaus Wolfgang Dietmaier Igors Iesalnieks Hans J. Schlitt 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2007,392(6):671-677
Background Insular thyroid carcinoma was described as a tumor with aggressive behavior, and patients usually present themselves with
an advanced tumor stage. Whether the insular component is an independent factor for poor prognosis remains unclear. Therefore,
in the present study, we compared the survival of patients with advanced insular, follicular, and papillary thyroid cancer.
Materials and methods The clinical behavior of tumors in three groups of patients with T4 thyroid carcinoma—8 patients with insular, 11 patients
with follicular, and 21 patients with papillary thyroid carcinomas—was compared. Disease-free survival and disease-specific
death were analyzed statistically. Cox regression analysis was used to evaluate the influence of histotype and other prognostic
factors.
Results At 3 years, survival was 37.5% (mean 26 months) among patients with insular thyroid carcinoma, 80% (mean 59 months) among
those with follicular, and 89% (mean 126 months) among those with papillary thyroid carcinomas (p = 0.007). Disease-free survival in patients without initial distant metastasis was worst in patients with insular thyroid
carcinoma (20%) compared to those with follicular (75%) and those with papillary thyroid carcinomas (71%).
Conclusion Patients with advanced insular thyroid carcinoma have a poorer outcome in comparison to patients with similar advanced stage
who have follicular or papillary thyroid carcinoma. 相似文献
26.
Tanja Bauer Matthias Günther Ulrich Bienzle Ruth Neuhaus Wolfgang Jilg 《Liver transplantation》2007,13(3):434-442
After liver transplantation for hepatitis-B-related diseases, patients currently receive lifelong treatment with hepatitis B immunoglobulin to prevent endogenous reinfection with hepatitis B virus (HBV). Active immunization with hepatitis B vaccine would be a preferable alternative; however, most attempts to immunize these patients with standard vaccine have failed. A recent study with a new adjuvanted hepatitis B vaccine was exceptionally successful, leading to a high-titered long-lasting antibody response in 80% of all vaccinees. To identify the immunological mechanisms behind these unexpected results, the successfully vaccinated participants were tested for hepatitis B surface antigen (HBsAg)-specific T and B cells, and their cellular responses to revaccination with conventional vaccine were studied. HBsAg-specific CD4(+) T lymphocytes could be detected in 13 of 16 patients after immunization with the new vaccine. Unexpectedly, these T cells produced almost exclusively interleukin (IL)-10 and had a CD4(+)/CD25(+) phenotype. They were functionally active, suppressing cytokine secretion in HBsAg-specific (Th1) cells, thus representing antigen-specific regulatory T cells (T(Reg)). Following a booster dose with conventional vaccine 22-31 months after completion of the initial vaccination series, the T-cell pattern in the revaccinated individuals changed substantially: 7 days after revaccination 9 of 11 individuals showed a switch to a Th1-type immune response with HBsAg-specific T cells secreting IL-2, interferon gamma and tumor necrosis factor alpha as observed in healthy controls. Four weeks after the booster, 4 patients still showed a Th1-type cytokine pattern, whereas in 5 patients only IL-10-secreting cells were detectable. After 1 year, in 3 of 4 revaccinated individuals only IL-10-secreting cells could be found, whereas the specific T cells of the fourth patient still showed a Th1-type of response. HBsAg-specific T(Reg) cells could be demonstrated in HBV-positive liver transplant recipients successfully immunized with a new adjuvanted vaccine. Revaccination led to immediate disappearance of the these cells and the appearance of HBsAg-specific T cells with a Th1-type cytokine profile, which in most cases were replaced by the IL-10-secreting regulatory cells during the following months. The specific induction of T(Reg) cells could contribute to the poor response of liver transplant recipients to conventional vaccine. In conclusion,, for successful vaccination of these patients, a vaccine with a strong inhibitory effect on T(Reg) cells would be desirable. 相似文献
27.
Tariquidar-induced P-glycoprotein inhibition at the rat blood-brain barrier studied with (R)-11C-verapamil and PET. 总被引:1,自引:0,他引:1
Jens P Bankstahl Claudia Kuntner Aiman Abrahim Rudolf Karch Johann Stanek Thomas Wanek Wolfgang Wadsak Kurt Kletter Markus Müller Wolfgang L?scher Oliver Langer 《Journal of nuclear medicine》2008,49(8):1328-1335
The multidrug efflux transporter P-glycoprotein (P-gp) is expressed in high concentrations at the blood-brain barrier (BBB) and is believed to be implicated in resistance to central nervous system drugs. We used small-animal PET and (R)-11C-verapamil together with tariquidar, a new-generation P-gp modulator, to study the functional activity of P-gp at the BBB of rats. To enable a comparison with human PET data, we performed kinetic modeling to estimate the rate constants of radiotracer transport across the rat BBB. METHODS: A group of 7 Wistar Unilever rats underwent paired (R)-11C-verapamil PET scans at an interval of 3 h: 1 baseline scan and 1 scan after intravenous injection of tariquidar (15 mg/kg, n = 5) or vehicle (n = 2). RESULTS: After tariquidar administration, the distribution volume (DV) of (R)-11C-verapamil was 12-fold higher than baseline (3.68 +/- 0.81 vs. 0.30 +/- 0.08; P = 0.0007, paired t test), whereas the DVs were essentially the same when only vehicle was administered. The increase in DV could be attributed mainly to an increased influx rate constant (K1) of (R)-11C-verapamil into the brain, which was about 8-fold higher after tariquidar. A dose-response assessment with tariquidar provided an estimated half-maximum effect dose of 8.4 +/- 9.5 mg/kg. CONCLUSION: Our data demonstrate that (R)-11C-verapamil PET combined with tariquidar administration is a promising approach to measure P-gp function at the BBB. 相似文献
28.
Burkhard H. A. von Rahden Brigitte Stigler Wolfgang Weiß Hubert J. Stein 《Journal of gastrointestinal surgery》2007,11(7):945-947
Management of upper gastrointestinal bleeding because of erosion of vessels by esophageal cancer may be challenging. We present
herein the angiographic images of a 49-year-old patient who was admitted with massive bleeding from a tumor-eroded inferior
thyroid artery. Attempts to control the bleeding by means of flexible endoscopy and insertion of a Sengstaken–Blakemore tube
had failed. The diagnosis was impressively demonstrated by multislice computed tomography with intravenous contrast in the
arterial phase and multiplanar reconstructions (computed tomography angiography) and by digital subtraction angiography. The
bleeding was successfully treated with superselective catheterization and coiling of the eroded vessel. 相似文献
29.
Wolfgang Heubner 《Journal of molecular medicine (Berlin, Germany)》1940,19(46):1199-1199
Ohne Zusammenfassung 相似文献
30.
Wolfgang Junker 《European archives of psychiatry and clinical neuroscience》1940,111(1):115-128
Ohne Zusammenfassung 相似文献