全文获取类型
收费全文 | 2317篇 |
免费 | 179篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 38篇 |
妇产科学 | 36篇 |
基础医学 | 347篇 |
口腔科学 | 51篇 |
临床医学 | 216篇 |
内科学 | 468篇 |
皮肤病学 | 97篇 |
神经病学 | 352篇 |
特种医学 | 87篇 |
外科学 | 237篇 |
综合类 | 12篇 |
一般理论 | 2篇 |
预防医学 | 154篇 |
眼科学 | 33篇 |
药学 | 212篇 |
中国医学 | 4篇 |
肿瘤学 | 148篇 |
出版年
2023年 | 54篇 |
2022年 | 76篇 |
2021年 | 137篇 |
2020年 | 84篇 |
2019年 | 109篇 |
2018年 | 117篇 |
2017年 | 80篇 |
2016年 | 104篇 |
2015年 | 118篇 |
2014年 | 118篇 |
2013年 | 148篇 |
2012年 | 189篇 |
2011年 | 181篇 |
2010年 | 97篇 |
2009年 | 95篇 |
2008年 | 116篇 |
2007年 | 104篇 |
2006年 | 118篇 |
2005年 | 103篇 |
2004年 | 85篇 |
2003年 | 56篇 |
2002年 | 67篇 |
2001年 | 27篇 |
2000年 | 18篇 |
1999年 | 13篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1980年 | 3篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1959年 | 4篇 |
1949年 | 2篇 |
1938年 | 1篇 |
1934年 | 2篇 |
1933年 | 1篇 |
1930年 | 2篇 |
1929年 | 2篇 |
1925年 | 1篇 |
1923年 | 1篇 |
排序方式: 共有2509条查询结果,搜索用时 15 毫秒
1.
Early detection of avascular necrosis of the femoral head following renal transplantation 总被引:3,自引:0,他引:3
B. Fink S. Degenhardt C. Paselk T. Schneider U. Mödder W. Rüther 《Archives of orthopaedic and trauma surgery》1997,116(3):151-156
This prospective study included 43 patients undergoing renal transplantations. Magnetic resonance imaging (MRI) and X-rays of the hip joints were produced 3 and 12 months after transplantation. In 6 hip joints of 4 patients (9.3%), we discovered femoral head necroses just 3 months after transplantation. Three of the hip joints affected were symptomatic and 3 painless. The MR images taken 12 months after transplantation revealed no additional femoral head necrosis. A core decompression was performed on 3 joints. In contrast to those with core decompression, the femoral heads without core decompression showed a progression of the necrosis in 2 of 3 cases. All 4 patients with femoral head necroses were younger than 50 years and exhibited a premature conversion of the haematopoietic marrow to fatty marrow in the area of the proximal femoral metaphysis. A similar premature conversion to fatty marrow was seen in 6 of the 22 (27.2%) patients younger than 50 years and without femoral head necroses. The doses in long-term steroid medication and the steroid doses during the rejection periods of the patients with femoral head necroses were not significantly higher than those for the patients with premature conversion to fatty marrow. The latter had also not received significantly higher doses than the patients whose MRI findings were inconspicuous. 相似文献
2.
Dorota Gabry's Annegret Dörfler Ala Yaromina Franziska Hessel Mechthild Krause Reinhard Oertel Prof. Dr. Michael Baumann 《Strahlentherapie und Onkologie》2008,184(1):48-53
PURPOSE: To evaluate the effect of lovastatin alone or combined with radiation on U87MG and FaDu cells in vitro and U87MG tumors in vivo. MATERIAL AND METHODS: Cell number, p21(WAF1) expression, apoptosis, reproductive cell death, and cell-cycle distribution were investigated after incubation of U87MG and FaDu cells in vitro. The effect of lovastatin (50 mg/kg/day) on tumor growth and on tumor growth delay after single-dose irradiation with 20 Gy was investigated using U87MG tumors in nude mice. RESULTS: Lovastatin dose dependently decreased cell number and proliferation of U87MG and FaDu cells. The proportion of cells in G0/G1 phase, apoptosis and p21 protein expression increased after lovastatin alone or combined with 4-Gy irradiation in both cell lines. Effects of lovastatin on cell cycle and cell number were more pronounced in U87MG compared to FaDu. No radiosensitization of clonogenic cells by lovastatin could be demonstrated in both cells lines, but the colony-forming ability after lovastatin alone was decreased in FaDu cells. In vivo, lovastatin decreased tumor volume over time but did not increase growth delay after irradiation of U87MG tumors with 20 Gy. CONCLUSION: The data support effects of lovastatin on proliferation, apoptosis and colony-forming ability in vitro and tumor volume in vivo. At the drug concentration achievable, lovastatin did not improve the effects of radiation on U87MG tumors in vivo. 相似文献
3.
Joncourt F Neuhaus B Jostarndt-Foegen K Kleinle S Steiner B Gallati S 《Human mutation》2004,23(4):385-391
Recently developed PCR systems offer online-monitoring of amplification and allow simple and reliable DNA quantification. We have used the LightCycler system to develop a simple and rapid method for direct identification of female carriers of deletions and duplications in the dystrophin gene. The challenge resides in the ability to identify the presence of a deleted or duplicated allele over the background contributed by the normal allele. Quantification is based on the determination of the ratio between potentially deleted/duplicated dystrophin exons and non-deleted/-duplicated reference exons using the unspecific dsDNA-dye SYBRgreen I. In a retrospective study, we evaluated our method in female relatives of DMD/BMD patients with known carrier status by comparative analysis of deleted or duplicated versus non-deleted/-duplicated exons. Carrier status was accurately attributed in 100% of cases, the mean ratios being 0.52+/-0.12 for deletion carriers (expected value: 0.5) and 1.56+/-0.18 for duplication carriers (expected value: 1.5) vs. 1.022+/-0.17 for non-carriers (expected value: 1.0). The method proved to be simple, rapid, reliable, and cost-effective. It may be used for direct determination of deletions/duplications in potential DMD/BMD carriers and may easily be adapted for other genetic conditions involving deletions and duplications. 相似文献
4.
Postextrasystolic regulation patterns of blood pressure and heart rate in patients with idiopathic dilated cardiomyopathy 总被引:12,自引:0,他引:12
Andreas Voss Vico Baier Agnes Schumann Annette Hasart Franziska Reinsperger Alexander Schirdewan Karl-Josef Osterziel Uwe Leder† 《The Journal of physiology》2002,538(1):271-278
Assessment of fluctuations in heart rate (HR) following a premature ventricular complex (PVC) is valuable for identifying patients at high risk of sudden cardiac death. We hypothesised that postextrasystolic potentiation is the main determinant of the regulation patterns of blood pressure (BP) and HR following a PVC. Twelve patients with idiopathic dilated cardiomyopathy (IDC) and 13 control subjects with single PVCs (comparable coupling intervals) were investigated. Non-invasive finger arterial BP and ECGs were analysed. Regulation patterns following a single PVC were quantified using the indices postextrasystolic amplitude potentiation (PEAP) and maximum turbulence slope of five consecutive mean BP values (MBP-TS), and compared with the HR turbulence parameters turbulence slope (HR-TS) and turbulence onset (HR-TO). PEAP was significantly higher in IDC patients compared to controls (48.7 ± 32.6 vs. 9.8 ± 5.4 %, P < 0.01), whereas MBP-TS was lower (0.97 ± 0.60 vs. 2.07 ± 1.04 mmHg BBI−1 (BBI, beat-to-beat interval), P < 0.05), as was HR-TS (8.46 ± 7.90 vs. 30.73 ± 22.90 ms BBI−1 , P < 0.01). HR-TO was significantly higher in IDC patients (−0.56 ± 2.19 vs. −5.52 ± 4.13 %, P < 0.01). In addition, the regulation patterns of BP and HR following a single PVC differed significantly between IDC patients and controls. Specifically, we observed pronounced PEAPs in IDC patients. The baroreflex response initiated by the low pressure amplitude of the PVC was suppressed in IDC patients due to the augmented potentiation of the first postextrasystolic blood pressure. Furthermore, IDC patients displayed impressive postextrasystolic pulsus alternans phenomena, whereas healthy subjects exhibited a typical baroreflex pattern. The pulsus alternans phenomenon seems to be triggered by a PVC. 相似文献
5.
The pitch identification performance of absolute pitch possessors has previously been shown to depend on pitch range, key color, and timbre of presented tones. In the present study, the dependence of pitch identification performance on key color and timbre of musical tones was examined by analyzing hit rates, reaction times, and pupillary responses of absolute pitch possessors (n = 9) and nonpossessors (n = 12) during a pitch identification task. Results revealed a significant dependence of pitch identification hit rate but not reaction time on timbre and key color in both groups. Among absolute pitch possessors, peak dilation of the pupil was significantly dependent on key color whereas the effect of timbre was marginally significant. Peak dilation of the pupil differed significantly between absolute pitch possessors and nonpossessors. The observed effects point to the importance of learning factors in the acquisition of absolute pitch. 相似文献
6.
Stuart Gilmour Louisa Degenhardt Wayne Hall Carolyn Day 《BMC medical research methodology》2006,6(1):16-9
Background
Intervention time series analysis (ITSA) is an important method for analysing the effect of sudden events on time series data. ITSA methods are quasi-experimental in nature and the validity of modelling with these methods depends upon assumptions about the timing of the intervention and the response of the process to it. 相似文献7.
Kainz Elena Stuff Karin Kahl Ursula Wiessner Christian Yu Yuanyuan von Breunig Franziska Nitzschke Rainer Haese Alexander Graefen Markus Fischer Marlene 《Quality of life research》2022,31(8):2397-2410
Quality of Life Research - The objective of this study was to determine the influence of postanesthesia care unit (PACU) delirium on self-reported cognitive function and perceived health... 相似文献
8.
Mastella Giulio Darstein Lars Raufhake Carsten Schneider Vera Corletto Anna Buiatti Alessandra Mller Alexander Schuessler-Hahn Franziska Gondert Markus Gerdes Heiko Martens Eimo 《Zeitschrift fur Gesundheitswissenschaften》2022,30(1):5-10
Journal of Public Health - Offshore wind energy is a fast growing market. Accordingly, a correspondingly large number of employees are working at the wind farms. Owing to the harsh operating... 相似文献
9.
Angela Pecoraro Marina Deuker Giuseppe Rosiello Franziska Stolzenbach Stefano Luzzago Zhe Tian Shahrokh F. Shariat Fred Saad Alberto Briganti Anil Kapoor Cristian Fiori Francesco Porpiglia Pierre I. Karakiewicz 《Urologic oncology》2021,39(4):239.e1-239.e7
BackgroundThe NCCN guidelines recommend active surveillance (AS) as an option for the initial management of cT1a 0-2 cm renal lesions. However, data about comparison between renal cell carcinoma (RCC) 0-2 cm vs. 2.1-4 cm are scarce.MethodsWithin the Surveillance, Epidemiology, and End Results database (2002–2016), 46,630 T1a NanyMany stage patients treated with nephrectomy were identified. Data were tabulated according to histological subtype, tumor grade (low [LG] vs. high [HG]), as well as age category and gender. Additionally, rates of synchronous metastases were quantified.ResultsOverall, 69.3 vs. 74.1% clear cell, 21.4 vs. 17.6% papillary, 6.9 vs. 6.8% chromophobe, 2.0 vs. 1.1% sarcomatoid dedifferentiation, 0.2 vs. 0.2% collecting duct histological subtype were identified for respectively 0-2 cm and 2.1-4 cm RCCs. In both groups, advanced age was associated with higher rate of HG clear cell and HG papillary histological subtype. In 0-2 cm vs. 2.1-4 cm RCCs, 13.8% vs. 20.2% individuals operated on harbored HG tumors and were more prevalent in males. Lower synchronous metastases rates were recorded in 0-2 cm RCC and ranged from 0 in respectively multilocular cystic to 0.9% in HG papillary histological subtype. The highest synchronous metastases rates were recorded in sarcomatoid dedifferentiation histological subtype (13.8% and 9.7%) in both groups.ConclusionsRelative to 2.1-4 cm RCCs, 0-2 cm RCCs harbored lower rates of HG tumors, lower rates of aggressive variant histology and lower rates of synchronous metastases. The indications and demographics of patients selected for AS may be expanded in the future to include younger and healthier patients. 相似文献
10.
Vu Thuy Khanh Le-Trilling Jana-Fabienne Ebel Franziska Baier Kerstin Wohlgemuth Kai Robin Pfeifer Aart Mookhoek Philippe Krebs Madita Determann Benjamin Katschinski Alexandra Adamczyk Erik Lange Robert Klopfleisch Christian M. Lange Viktoriya Sokolova Mirko Trilling Astrid M. Westendorf 《European journal of immunology》2023,53(2):2249940
Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis. 相似文献