全文获取类型
收费全文 | 2153篇 |
免费 | 124篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 39篇 |
妇产科学 | 55篇 |
基础医学 | 288篇 |
口腔科学 | 13篇 |
临床医学 | 220篇 |
内科学 | 469篇 |
皮肤病学 | 55篇 |
神经病学 | 309篇 |
特种医学 | 102篇 |
外科学 | 192篇 |
综合类 | 6篇 |
预防医学 | 133篇 |
眼科学 | 20篇 |
药学 | 179篇 |
中国医学 | 5篇 |
肿瘤学 | 201篇 |
出版年
2024年 | 3篇 |
2023年 | 19篇 |
2022年 | 58篇 |
2021年 | 63篇 |
2020年 | 33篇 |
2019年 | 39篇 |
2018年 | 62篇 |
2017年 | 49篇 |
2016年 | 62篇 |
2015年 | 68篇 |
2014年 | 78篇 |
2013年 | 99篇 |
2012年 | 167篇 |
2011年 | 163篇 |
2010年 | 90篇 |
2009年 | 96篇 |
2008年 | 163篇 |
2007年 | 160篇 |
2006年 | 137篇 |
2005年 | 123篇 |
2004年 | 135篇 |
2003年 | 114篇 |
2002年 | 89篇 |
2001年 | 25篇 |
2000年 | 17篇 |
1999年 | 22篇 |
1998年 | 10篇 |
1997年 | 15篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1945年 | 9篇 |
1943年 | 4篇 |
排序方式: 共有2294条查询结果,搜索用时 12 毫秒
11.
Prognostic value of CD40 in adult soft tissue sarcomas. 总被引:4,自引:0,他引:4
Alessandro Ottaiano Anna De Chiara Francesco Perrone Gerardo Botti Flavio Fazioli Vincenzo De Rosa Nicola Mozzillo Vincenzo Ravo Brunello Morrica Ciro Gallo Carmela Pisano Maria Napolitano Paolo Antonio Ascierto Rosario Vincenzo Iaffaioli Gaetano Apice 《Clinical cancer research》2004,10(8):2824-2831
PURPOSE: The purpose is to evaluate the expression of CD40, a membrane protein predominantly expressed on B cells, dendritic cells, and macrophages, in a series of adult soft tissue sarcomas and to test its possible prognostic value. EXPERIMENTAL DESIGN: CD40 expression was studied by immunohistochemistry. Correlations with other baseline characteristics of patients and tumors were analyzed with chi(2) test. The prognostic value was studied with univariable and multivariable analysis adjusted by age, sex, tumor size, grade, location, and distant metastases. RESULTS: Eighty-two patients, between January 1994 and May 2001, were analyzed. Membrane or cytoplasmic staining for CD40 protein was absent in 30% of the tumors but present in <10% of cells in 22 (27%), in 10% to 50% in 23 (28%), and in >50% of cells in 12 (15%) tumors. There was no correlation between CD40 expression and age, sex, size, grade, and location of the primary tumor and distant metastases. With 61 patients (74.4%) progressed and 31 (37.8%) dead, CD40 expression was a significant prognostic factor for disease-free and overall survival at univariable and multivariable analysis. Patients with tumors expressing CD40 in >50% of cells had a dramatically unfavorable prognosis with median disease-free and overall survival of 7 and 17 months, respectively, and hazard ratios of relapse and death as compared with patients with CD40-negative tumors of 2.89 (95% confidence interval: 1.26-6.60) and 6.92 (95% confidence interval: 2.18-22.0), respectively. CONCLUSIONS: These data suggest that expression of CD40 protein in >50% of cells might indicate an unfavorable prognosis in adult soft tissue sarcomas. 相似文献
12.
Isolation and structure elucidation of new and unusual saxitoxin analogues from mussels 总被引:1,自引:0,他引:1
Dell'Aversano C Walter JA Burton IW Stirling DJ Fattorusso E Quilliam MA 《Journal of natural products》2008,71(9):1518-1523
Chemical analyses of plankton and highly toxic mussel samples collected in eastern Canada during an intense bloom of the dinoflagellate Alexandrium tamarense established the presence of a complex mixture of paralytic shellfish poisoning (PSP) toxins. Application of a newly developed technique, hydrophilic interaction liquid chromatography-mass spectrometry, confirmed the identities of the known toxins and revealed the presence in the mussels of five saxitoxin analogues (M1-M5) that were not present in the plankton. Four of these compounds were isolated and their structures established by tandem mass spectrometry, 1D- and 2D-NMR spectroscopy, and chemical interconversion experiments. One of these was found to be 11beta-hydroxysaxitoxin (M2), while the other three were found to be new saxitoxin analogues, namely, 11beta-hydroxy-N-sulfocarbamoylsaxitoxin (M1), 11,11-dihydroxy-N-sulfocarbamoylsaxitoxin (M3), and 11,11-dihydroxysaxitoxin (M4). Compound M5 remains unidentified because of insufficient material for characterization. 相似文献
13.
Bolignano D Coppolino G Crascì E Campo S Aloisi C Buemi M 《The journal of obstetrics and gynaecology research》2008,34(2):137-143
Renal damage, which can be caused by gestational anomalies such as pre-eclampsia, carries a risk of gestational complications; the greatest risk being in women who become pregnant while on hemodialysis or peritoneal dialysis. If this rare event occurs, there is a marked increase in the risk of pre-eclampsia, early uterine contractions and hydramnios, hypertensive crisis, preterm delivery and intrauterine growth retard. Furthermore, newborns are almost always of low birthweight. Patients who undergo renal transplantation are another high-risk category. In such cases, the pregnancy itself can compromise the success of the transplant and the immunosuppressive therapy correlated to it can become a threat to the course of the pregnancy and normal fetal growth. Therefore, in view of the lack of appropriate guidelines for the best possible approach to the treatment of women on dialysis or of those with a renal transplantation, it is best to advise these patients against becoming pregnant and/or to provide a valid counselling service illustrating the extreme difficulties and dangers involved in becoming pregnant. 相似文献
14.
Gennaro Daniele Clorinda Schettino Laura Arenare Domenico Bilancia Fabio Farinati Piera Federico Stefano Tamberi Gino Crivellari Sandro Barni Raffaella Tortora Francesco Izzo Antonio Frassoldati Luigi Cavanna Claudia Mucciarini Luigi Bolondi Angelo Dinota Filippo Pelizzaro Maria Carmela Piccirillo Piera Gargiulo Massimo Di Maio Ciro Gallo Francesco Perrone Bruno Daniele 《肝癌研究(英文版)》2021,7(7):52-65
Aim: Only patients with good liver function {[Child-Pugh (CP)] A class} were eligible for trials testing sorafenib as first-line treatment of hepatocellular car... 相似文献
15.
Gabriel Zerbi was born in Verona in 1445 and died in Dalmatia in 1505. He was professor of philosophy in Padua at the age of 22, and moved to Bologna where he became professor of medicine and philosophy. In Rome at the time of Sixtus V and Innocentius VIII, he was archiater and professor of medicine. He completed his academic career in Padua where he worked from 1494 to 1505 with a salary of 600 florins a month. A man of vast culture, a philosopher, physician and professor of medicine, he wrote many books: (1) Questiones Metaphysicae; (2) Gerentocomia; (3) De Cautelis Medicorum; (4) Liber anatomiae corporis humani et singulorum membrorum illius; (5) De anatomia infantiis et porci ex traditione Cophonis, and (6) Libellus de preservatione corporum a passione calculosa. His contribution to anatomy was superb. Through him the discipline became the basis of modern medicine. The core of this article deals with some passages of Zerbi's chapters on the anatomy of the kidneys and bladder. 相似文献
16.
Intravascular hemolysis in patients with new-generation prosthetic heart valves: a prospective study 总被引:2,自引:0,他引:2
Mecozzi G Milano AD De Carlo M Sorrentino F Pratali S Nardi C Bortolotti U 《The Journal of thoracic and cardiovascular surgery》2002,123(3):550-556
OBJECTIVE: A prospective clinical study was designed to assess the frequency and severity of intravascular hemolysis in patients with new-generation, normally functioning prosthetic heart valves. METHODS: Hemolysis was evaluated in 172 patients with a mechanical prosthesis (53 CarboMedics and 119 Sorin Bicarbon) and in 106 patients with a bioprosthesis (15 St Jude Medical Toronto, 19 Baxter Perimount, and 72 Medtronic Mosaic) in the aortic position, mitral position, or both. Aortic valve replacement was performed in 206 patients, mitral valve replacement in 59 patients, and double valve replacement in 13 patients. The presence of hemolysis was assessed on the basis of the level of serum lactic dehydrogenase and serum haptoglobin and the presence and amount of reticulocytes and schistocytes in the peripheral blood. Severity of intravascular hemolysis was estimated on the basis of serum lactic dehydrogenase. Clinical, echocardiographic, and hematologic evaluations were performed 1, 6, and 12 months after discharge. RESULTS: None of the 278 patients experienced decompensated anemia, whereas at 12 months, mild subclinical hemolysis was identified in 49 patients, 44 (26%) with a mechanical prosthesis and 5 (5%) with a bioprosthesis (P <.001). At multivariate analysis, independent predictors of the presence of subclinical hemolysis were mitral valve replacement (P <.001), use of a mechanical prosthesis (P =.002), and double valve replacement (P =.02). Frequency of hemolysis in patients with stented aortic bioprostheses was 3%, whereas it was absent in those with stentless valves. Among mechanical valve recipients, double versus single valve replacement (P =.04) and mitral versus aortic valve replacement (P =.05) were correlated with the presence of hemolysis; double valve recipients also showed a more severe degree of hemolysis (P =.03). In patients with a Sorin Bicarbon prosthesis, hemolysis was less frequent (22% vs 34%, P =.09) and severe (P <.001) than in those with a CarboMedics prosthesis. CONCLUSIONS: In normally functioning prosthetic heart valves, subclinical hemolysis is a frequent finding. A low incidence of hemolysis is found in stented biologic prostheses, and it is absent in stentless aortic valves. Modifications of valve design may contribute to minimize the occurrence of hemolysis in mechanical prostheses. 相似文献
17.
Cottone S Lorito MC Riccobene R Nardi E Mulè G Buscemi S Geraci C Guarneri M Arsena R Cerasola G 《Journal of nephrology》2008,21(2):175-179
Traditional risk factors such as hypertension, diabetes, dyslipidemia, obesity and metabolic syndrome, as well as additional nontraditional risk factors, can damage the kidney directly and by promoting intrarenal atherogenesis. Evidence indicates that increased oxidative stress and inflammation may mediate most of the effects of risk factors on the kidney. Clinical studies have demonstrated a relationship between oxidative stress and inflammatory biomarkers, and a few studies indicate an inverse correlation of oxidative stress biomarkers with estimated glomerular filtration rate (eGFR). Further, surrogate indexes of atherosclerosis such as intima-media thickness and aortic pulse wave velocity have been demonstrated to be related to plasma concentrations of markers of endothelial activation, inflammation and fibrosis in patients with different stages of chronic kidney disease (CKD). Moreover, plasma concentrations of high-sensitivity C-reactive protein have been shown to be increased and related to left ventricular mass in CKD individuals having left ventricular hypertrophy. In contrast, in these patients, decreases in fetuin-A plasma levels have been reported. Considering the complex background of the pathophysiological changes characterizing CKD patients, we can consider cardiovascular disease a multifactorial complication of CKD. 相似文献
18.
Ricciardelli C Jackson MW Choong CS Stahl J Marshall VR Horsfall DJ Tilley WD 《The Prostate》2008,68(8):830-838
BACKGROUND: In this study, we investigated the expression of HER-2/neu and AR in clinically organ-confined prostate cancer to determine whether alterations in these signaling pathways contribute to the development of metastatic disease. METHODS: HER-2/neu and AR immunoreactivity were evaluated in archived prostatic tissues obtained from 53 men with clinically organ-confined disease who underwent radical prostatectomy. Associations between AR and HER-2/neu immunostaining and disease outcome were determined. RESULTS: Seventy percent (37/53) of tumors exhibited high levels of HER-2/neu immunostaining and 68% (36/53) of tumors had elevated AR levels. Patients with high levels of both HER-2/neu and AR had the highest rate of PSA failure (56%, 15/27) compared with no PSA failures amongst seven patients with low levels of both HER-2/neu and AR (log rank statistic 7.69, P = 0.021). Concurrent high levels of HER-2/neu and AR expression were significantly associated with high pathological stage (P = 0.027) and development of metastatic disease (P = 0.022). CONCLUSIONS: These findings support the notion that both the HER-2/neu and AR signaling pathways may contribute to development of metastatic disease. The subset of prostate tumors with increased HER-2/neu and AR levels may benefit from treatment strategies that target both signaling pathways. 相似文献
19.
Lombardi CP Raffaelli M D'alatri L De Crea C Marchese MR Maccora D Paludetti G Bellantone R 《World journal of surgery》2008,32(5):693-700
Background Voice and swallowing symptoms are frequently reported after thyroidectomy even in absence of objective voice alterations.
We evaluated the influence of the video-assisted approach on voice and swallowing outcome of thyroidectomy.
Methods Sixty-five patients undergoing total thyroidectomy (TT) were recruited. Eligibility criteria were: nodule size ≤30 mm, thyroid
volume ≤30 ml, no previous neck surgery. Exclusion criteria were: younger than aged 18 years and older than aged 75 years,
vocal fold paralysis, history of voice, laryngeal or pulmonary diseases, malignancy other than papillary thyroid carcinoma.
Patients were randomized for video-assisted (VAT) or conventional (CT) thyroidectomy. Videostrobolaryngoscopy (VSL), acoustic
voice analysis (AVA), and maximum phonation time (MPT) evaluation were performed preoperatively and 3 months after TT. Subjective
evaluation of voice (voice impairment score = VIS) and swallowing (swallowing impairment score = SIS) were obtained preoperatively,
1 week, 1 month, and 3 months after TT.
Results Fifty-three patients completed the postoperative evaluation: 29 in the VAT group, and 24 in the CT group. No laryngeal nerves
injury was shown at postoperative VSL. Mean postoperative MPT, F
0, F
low, F
high, and the number of semitones were significantly reduced in the CT group but not in the VAT group. Mean VIS 3 months after
surgery was significantly higher than preoperatively in CT group but not in the VAT group. Mean SIS was significantly decreased
1 and 3 months after VAT but not after CT.
Conclusions The incidence and the severity of early voice and swallowing postthyroidectomy symptoms are significantly reduced in patients
who undergo VAT compared with conventional surgery.
Presented at the ISW2007—IAES free paper session, Montreal, Canada, August 26–30, 2007. 相似文献
20.
Carmine Zoccali Renke Maas Sebastiano Cutrupi Patrizia Pizzini Piero Finocchiaro Francesco Cambareri Vincenzo Panuccio Carmela Martorano Friedrich Schulze Giuseppe Enia Giovanni Tripepi Rainer Boger 《Nephrology, dialysis, transplantation》2007,22(3):801-806
BACKGROUND AND METHODS: The endogenous inhibitor of nitric oxide synthase (NOs) asymmetrical dimethyl-arginine (ADMA) has been implicated as a possible modulator of inducible NOs during acute inflammation. We examined the evolution in the plasma concentration of ADMA measured at the clinical outset of acute inflammation and after its resolution in a series of 17 patients with acute bacterial infections. RESULTS: During the acute phase of inflammation/infection, patients displayed very high levels of C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin and nitrotyrosine. Simultaneous plasma ADMA concentration was similar to that in healthy subjects while symmetric dimethyl-arginine (SDMA) levels were substantially increased and directly related with creatinine. When infection resolved, ADMA rose from 0.62 +/- 0.23 to 0.80 +/- 0.18 micromol/l (+29%, P = 0.01) while SDMA remained unmodified. ADMA changes were independent on concomitant risk factor changes and inversely related with baseline systolic and diastolic pressure. Changes in the ADMA/SDMA ratio were compatible with the hypothesis that inflammatory cytokines activate ADMA degradation. CONCLUSIONS: Resolution of acute inflammation is characterized by an increase in the plasma concentration of ADMA. The results imply that ADMA suppression may actually serve to stimulate NO synthesis or that in this situation plasma ADMA levels may not reflect the inhibitory potential of this methylarginine at the cellular level. 相似文献