全文获取类型
收费全文 | 806篇 |
免费 | 31篇 |
国内免费 | 7篇 |
专业分类
儿科学 | 17篇 |
妇产科学 | 31篇 |
基础医学 | 91篇 |
口腔科学 | 9篇 |
临床医学 | 97篇 |
内科学 | 132篇 |
皮肤病学 | 7篇 |
神经病学 | 162篇 |
特种医学 | 21篇 |
外科学 | 113篇 |
综合类 | 1篇 |
预防医学 | 36篇 |
眼科学 | 13篇 |
药学 | 58篇 |
肿瘤学 | 56篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 16篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 20篇 |
2017年 | 17篇 |
2016年 | 16篇 |
2015年 | 17篇 |
2014年 | 19篇 |
2013年 | 43篇 |
2012年 | 41篇 |
2011年 | 52篇 |
2010年 | 43篇 |
2009年 | 46篇 |
2008年 | 65篇 |
2007年 | 51篇 |
2006年 | 61篇 |
2005年 | 39篇 |
2004年 | 34篇 |
2003年 | 38篇 |
2002年 | 40篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1967年 | 3篇 |
1934年 | 1篇 |
排序方式: 共有844条查询结果,搜索用时 15 毫秒
1.
2.
3.
Gottfried Greve Svein Rotevatn Ketil Grong Lodve Stangeland 《Virchows Archiv : an international journal of pathology》1988,413(3):205-213
Summary We have studied the histogenesis of malignant lymphoma (ML), small cleaved cell of the B-cell type and intermediate lymphocytic lymphoma (mantle zone lymphoma) by comparing immunophenotypes and ALP-activity of neoplastic cells with those of germinal center cells (follicular center cells) anti mantle zone (MZ) cells of secondary follicles in non-neoplastic lymphoid tissues. The neoplastic cells in 3 cases of ML, follicular, small cleaved cell and 1 case of ML, small cleaved cell expressed the phenotypes similar to those of germinal center (GC) B lymphocytes (SIgM+, B1+, B2+, CALLA+, SigD–, IL-2R–, Leu-1– and ALP–). The neoplastic cells in 2 cases of ML, follicular, small cleaved cell and 12 cases of ML, diffuse, small cleaved cell displayed the characteristic phenotypes of MZ B lymphocytes (SIgM+, SIgD+, BA-1+, IL-2R+, Leu-1+ and ALP+). The phenotypes of 2 cases of mantle zone lymphoma were closely comparable with those of MZ B lymphocytes. These findings indicate that the histogenesis of ML, small cleaved cell of the B-cell type is heterogeneous and can be divided phenotypically into 2 types (GC B lymphocyte origin and MZ B lymphocyte origin). It is also apparent that intermediate lymphocytic lymphoma (mantle zone lymphoma) is derived from MZ B lymphocytes of secondary follicles.This work was supported by a Grant-in-Aid for Cancer Research From the Ministry of Health and Welfare (NO. 61-2) 相似文献
4.
R Mahalingam P Clarke M Wellish A N Dueland K F Soike D H Gilden R Cohrs 《Virology》1992,188(1):193-197
We used polymerase chain reaction to analyze the prevalence and distribution of latent simian varicella virus (SVV) in ganglionic and nonganglionic tissues from nine African green monkeys experimentally infected with SVV. Primers specific for three different regions of the SVV genome were used for amplification. SVV DNA sequences were detected in trigeminal ganglia from seven of nine monkeys and in thoracic ganglia from seven of nine monkeys. Analysis of DNA from nonneuronal tissues of three monkeys and from adrenal glands of nine monkeys revealed the presence of SVV-specific sequences in the adrenal gland of one monkey. The results indicate that, like human varicella, SVV becomes latent primarily in ganglia at multiple levels of the neuraxis, and more than one region of the SVV genome is present in latently infected ganglia. SVV latency in primates may be a useful model for varicella latency in humans. 相似文献
5.
For a drug with concentration-dependent serum protein binding, the unbound fraction of drug decreases during the drug elimination process. The clearance of the drug at a given blood flow rate is lower than would be expected from the observed unbound fraction in venous blood from a noneliminating organ. Based on both the well-stirred and parallel tube models, simulations demonstrated that consideration of concentration-dependent binding during drug elimination is important when the intrinsic clearance is higher than the blood flow and when the unbound drug concentration is much greater than the dissociation equilibrium constant of the binding complex.Supported in part by Grant GM 28423 from the National Institutes of General Medical Sciences, NIH. 相似文献
6.
Jacopo Lanari Morten Hagness Alessandra Sartori Eugenia Rosso Enrico Gringeri Svein Dueland Umberto Cillo Pål-Dag Line 《Transplant international》2021,34(9):1722-1732
Liver transplantation (LT) for colorectal liver metastasis (CRLM) may provide excellent survival rates in patients with unresectable disease. High tumor load is a risk factor for recurrence and low overall survival (OS) after liver resection (LR). We tested the hypothesis that LT could offer better survival than LR in patients with high tumor load. LR performed at Padua University Hospital for CRLM was compared with LT for unresectable CRLM performed both at Oslo and Padua. High tumor load was defined as tumor burden score (TBS) ≥ 9, and inclusion criteria were as in the SECA-I transplant study. 184 patients were eligible: 128 LRs and 56 LTs. 5-year OS after LR and LT was 40.5% and 54.7% (P = 0.102). In the high TBS cohort, 5-year OS after LR and LT was 22.7% and 52.2% (P = 0.055). In patients with Oslo score ≤ 2 and TBS ≥ 9 (13 LR; 24 LT) the 5-year OS after LR and LT was 14.6% and 69.1% (P = 0.002). The corresponding disease-free survival (DFS) was 0% and 22.9% (P = 0.005). Selected CRLM patients with low Oslo score and high TBS could benefit from LT with survival outcomes that are far better than what is achieved by LR. 相似文献
7.
PURPOSE: Recent experimental work indicates a major role for PTEN and p27 in prostate cancer. The combined loss of PTEN and p27 was found to strongly increase the development of prostatic carcinomas in an animal model, and a prognostic value in human tumors was postulated. The purpose of our study was to examine the impact of PTEN and p27 on prognosis in a series of prostate cancer patients, using high-density tissue microarray technology for expression profile analysis of PTEN, p27, and tumor cell proliferation. EXPERIMENTAL DESIGN: The expression of PTEN and p27 was examined in primary prostatic carcinomas from 104 patients treated with radical prostatectomy and with complete follow-up available. Using high-throughput tissue microarrays, the expression of PTEN and p27 was examined by immunohistochemistry, and the results were related to clinicopathological variables, tumor cell proliferation (Ki-67), and time to disease progression. RESULTS: PTEN was negative in 28 of 103 tumors (27.2%), and median p27 expression was 64%. Combined loss of PTEN and p27 expression defined a group of 18 tumors (17.5%) associated with increased tumor diameter, seminal vesicle invasion, increased pathological stage, and elevated tumor cell proliferation by Ki-67. Cox regression analysis revealed that loss of PTEN/p27 expression and histological grade were both independent predictors of time to biochemical failure and clinical recurrence. CONCLUSIONS: Our findings strongly support the importance of PTEN and p27 for the progression of human prostate cancer because loss of PTEN/p27 expression was associated with adverse pathological parameters, tumor cell proliferation, and increased risk of recurrence. 相似文献
8.
Mahala Livingston Pavitra Pillay Siphosenkosi Gift Zulu Leiv Sandvik Jane Dene Kvalsvig Silindile Gagai Hashini Nilushika Galappaththi-Arachchige Elisabeth Kleppa Patricia Ndhlovu Birgitte Vennervald Svein Gunnar Gundersen Myra Taylor Eyrun F. Kjetland 《The American journal of tropical medicine and hygiene》2021,104(6):2055
9.
Havre RF Elde E Gilja OH Odegaard S Eide GE Matre K Nesje LB 《Ultrasound in medicine & biology》2008,34(10):1638-1650
Real-time elastography is a method for visualization of the elastic properties of soft tissue and may potentially enable differentiation between malignant and benign pathologic lesions. Our aim was to validate the method on a tissue-mimicking (TM) phantom and to evaluate the influence of different scanning parameters and investigator variability. A TM-phantom containing eight spherical inclusions with known storage modulus was examined using two different transducers on an ultrasound (US) scanner equipped with software for real-time elasticity imaging. The ultrasound transducers were moved vertically in a repetitive manner to induce strain. Two investigators performed series of standardized elastography scans applying a 0-4 categorical quality scale to evaluate the influence of seven parameters: dynamic range of elasticity, region-of-interest, frequency of transducer movement, rejection of elastogram noise, frame rate, persistence and smoothing. Subsequently, repeated examinations of four selected inclusions were performed using a visual analog scale (VAS) where investigators marked a 100 mm horizontal line representing the span in image quality based on experience from the first examination. The hardest and softest inclusions were imaged more clearly than the inclusions with elasticity more similar to the background material. Intraobserver agreement on elastogram quality was good (kappa: 0.67 - 0.75) and interobserver agreement average (kappa: 0.55 - 0.56) when using the categorical scale. The subsequent VAS evaluation gave intraclass-correlation coefficients for the two observers of 0.98 and 0.93, respectively, and an interclass-correlation coefficient of 0.93. Real-time elastography adequately visualized isoechoic inclusions with different elastic properties in a TM-phantom with acceptable intra- and interobserver agreement. Dynamic range of elasticity was the parameter with most impact on the elastographic visualization of inclusions. 相似文献
10.
Svein Oskar Frigstad Marte Høivik Jørgen Jahnsen Sandra Rinne Dahl Milada Cvancarova Tore Grimstad 《Scandinavian journal of gastroenterology》2017,52(1):100-106
Background and aim: Vitamin D deficiency is common in inflammatory bowel disease (IBD). The aims of the present study were to determine the prevalence of vitamin D deficiency and to identify clinical and epidemiological variables associated with vitamin D deficiency in an outpatient population with IBD.Methods: Participants were recruited from nine hospitals in the southeastern and western regions of Norway as part of an observational, multicentre study from March 2013 to April 2014. Clinical and epidemiological data were collected by interview and from medical records. All analyses of serum 25-hydroxyvitamin D (25-OH-D) were performed in the same laboratory.Results: In total, 49% (200/408) of the patients had a 25-OH-D concentration <50?nmol/L, including 53% (122/230) of the Crohn’s disease (CD) patients and 44% (78/178) of the ulcerative colitis (UC) patients. In CD patients, disease activity, measured as the HBI, was inversely associated with vitamin D deficiency. No such association was observed with the Simple Clinical Colitis Activity Index (SCCAI) scores in UC, but in UC patients, vitamin D deficiency was associated with elevated faecal calprotectin >100?mg/kg. In patients with CD, there were significantly more relapses during the previous year in patients with vitamin D deficiency.Conclusions: Vitamin D deficiency was common, especially in CD, and was associated with increased disease activity, a relapsing disease course and higher inflammatory activity. 相似文献