全文获取类型
收费全文 | 1853篇 |
免费 | 92篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 12篇 |
妇产科学 | 26篇 |
基础医学 | 239篇 |
口腔科学 | 26篇 |
临床医学 | 160篇 |
内科学 | 473篇 |
皮肤病学 | 86篇 |
神经病学 | 132篇 |
特种医学 | 62篇 |
外科学 | 255篇 |
综合类 | 6篇 |
预防医学 | 71篇 |
眼科学 | 48篇 |
药学 | 137篇 |
中国医学 | 5篇 |
肿瘤学 | 221篇 |
出版年
2023年 | 8篇 |
2022年 | 18篇 |
2021年 | 36篇 |
2020年 | 26篇 |
2019年 | 24篇 |
2018年 | 41篇 |
2017年 | 34篇 |
2016年 | 53篇 |
2015年 | 58篇 |
2014年 | 50篇 |
2013年 | 96篇 |
2012年 | 145篇 |
2011年 | 115篇 |
2010年 | 75篇 |
2009年 | 62篇 |
2008年 | 134篇 |
2007年 | 133篇 |
2006年 | 154篇 |
2005年 | 127篇 |
2004年 | 104篇 |
2003年 | 105篇 |
2002年 | 98篇 |
2001年 | 19篇 |
2000年 | 7篇 |
1999年 | 13篇 |
1998年 | 21篇 |
1997年 | 12篇 |
1996年 | 16篇 |
1995年 | 16篇 |
1994年 | 17篇 |
1993年 | 5篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1975年 | 5篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1970年 | 2篇 |
1909年 | 2篇 |
排序方式: 共有1976条查询结果,搜索用时 13 毫秒
61.
Enzo Ierardi Claudia Sorrentino Mariabeatrice Principi Floriana Giorgio Giuseppe Losurdo Alfredo Di Leo 《肝胆外科与营养》2015,4(4):289-292
Intestinal microbiota is a “dynamic organ” influencing host metabolism, nutrition, physiology and immune system. Among its several interactions, the role of a phosphatidylcholine metabolite derived by gut flora activity, i.e., trimethylamine-N-oxide (TMAO), allows perceiving a novel insight in the cardiovascular risk scenario, being a strong predictor of this condition. Based on current reports, including the paper of Tang et al., we describe here: the possible role of intestinal microbiota in cardiovascular risk as well as potential interventions to reduce gut flora TMAO production by diet, probiotics and antibiotics. Finally, we highlight the possibility of evaluating, monitoring and modulating TMAO in order to use its serum levels as a marker of cardiovascular risk in the next future, when the need of controlled studies on large series will be satisfied. 相似文献
62.
Robert G Pinkerton James P Near Enzo A Barberi Ravi S Menon Robert Bartha 《Magnetic resonance in medicine》2007,57(2):455-458
A novel torso transceive surface coil array for prostate magnetic resonance imaging (MRI) and spectroscopy (MRS) at 4T is presented. It is shown that with the use of a conformal transceive surface coil array with 50 Omega transmitter amplifiers and receiver preamplifiers, one can perform whole-volume torso imaging while maintaining the high signal-to-noise ratio (SNR) inherent to surface coil designs. Recent theoretical considerations have shown that by focusing the infringing radiofrequency (RF) electromagnetic field, one can achieve increased penetration and signal homogeneity compared to a conventional circularly polarized driving scheme. A variation of this driving scheme particular to the proposed coil design resulted in a twofold increase in SNR in the prostate compared to that achieved with a conventional circularly polarized driving scheme. The novel transceive surface coil array presented is capable of full-volume imaging of the human torso at 4T while maintaining signal penetration in the deep region of the prostate gland. 相似文献
63.
Alessandro Castagna Elyazid Mouhsine Marco Conti Enzo Vinci Mario Borroni Antonio Giardella Raffaele Garofalo 《Knee surgery, sports traumatology, arthroscopy》2007,15(5):645-648
Long head biceps (LHB) tendon pathologies are becoming increasingly recognized causes of shoulder pain in the published literature.
Instability of LHB presenting as dislocation or subluxation has been recently recognized as a possible cause of disabling
pain or discomfort of the shoulder. A clinical diagnosis of LHB instability is very difficult and often confounding because
of association with other shoulder pathologies. However, an early diagnosis of LHB instability is important in order to prevent
the evolution of lesions of the biceps pulley until an internal anterosuperior impingement of the shoulder (ASI) and subscapular
tear occur. The advent of arthroscopy contributed to enhance understandings. The goal of this article is to describe an arthroscopic
sign, the chondral print on the humeral head, associated with a LHB instability, that when present can be very useful to help
the surgeon to make the diagnosis of unstable LHB tendon. 相似文献
64.
Enzo Bonora Stefano Orioli Carlo Coscelli Giampiero Buzzelli Paolo Gentilini Ugo Butturini 《Acta diabetologica》1984,21(3):241-250
Summary In the present investigation, insulin sensitivity and fasting levels of insulin, C-peptide, glucagon, growth hormone and free
fatty acids were estimated and correlated in a population of individuals suffering from liver cirrhosis or chronic hepatitis.
Insulin sensitivity, assessed by glucose disappearance rate after intravenous bolus injection of insulin, was reduced but
not significantly different from controls in subjects with chronic persistent hepatitis, while it was significantly reduced
in individuals suffering from chronic active hepatitis or liver cirrhosis. Insulin, glucagon, growth hormone, and free fatty
acid fasting levels were higher than in healthy subjects in individuals with liver cirrhosis or chronic active hepatitis but
not in subjects with chronic persistent hepatitis. C-peptide concentrations did not differ from controls in subjects with
liver disease. Significant negative correlations occurred between coefficients of insulin sensitivity and fasting concentrations
of insulin, glucagon, growth hormone and free fatty acids, but not with fasting levels of C-peptide. Positive relationships
were present between fasting levels of free fatty acids and both glucagon and growth hormone concentrations. These results
show that, unlike subjects with liver cirrhosis and chronic active hepatitis, individuals suffering from chronic persistent
hepatitis do not differ from healthy subjects in insulin sensitivity and fasting levels of insulin, glucagon, growth hormone,
and free fatty acids. Moreover, they suggest that both hyperinsulinemia and high concentrations of counterregulatory substances
might play a role in the pathogenesis of insulin resistance in subjects suffering from chronic liver disease.
Supported by grants from the Ministry of Public Education and grant No. 83/02132.04 from the National Research Council (C.N.R.),
Rome. 相似文献
65.
E Menconi E Lepri E Bonmassar L Frati A Barzi 《International journal of tissue reactions》1986,8(6):485-492
The present study was aimed at defining the standard conditions for predictive chemosensitivity testing of human leukaemias. The in vitro cytotoxic potential of 11 anticancer drugs against L1210 murine leukaemia was comparatively determined 3 and 48 h after in vitro exposure of leukaemia cells to these agents. In preliminary testing, drug-induced damage was estimated in terms of percent inhibition of: tumour cell proliferation, by microscopic determination of viable cell numbers; and DNA synthesis, by measuring the extent of incorporation of the labelled nucleoside 125IUdR. Since the two tests appeared to yield comparable results, all subsequent experiments on the various murine tumours were performed using the radiolabel incorporation technique. The results obtained pointed out that this metabolic assay performed 48 hours after drug exposure appears to be capable of predicting both "spontaneous" and "induced" in vivo resistance of murine leukaemias. 相似文献
66.
Marinella Portolani Claudio Cermelli Alessandra Moroni Maria Francesca Bertolani Dario Di Luca Enzo Cassai Anna Maria Sabbatini 《Journal of medical virology》1993,39(2):146-151
The development of hepatocellular carcinoma (HCC) is very closely associated with chronic liver disease. In the present study, the prevalence of the hepatitis B virus (HBV) and hepatitis C virus (HCV) infection as a causative role in the development of HCC was analysed in 253 patients with HCC, who were admitted to our hospital during 1976–90. Among these patients, 68 (27%) were positive for HBsAg but negative for anti-HCV antibody (group I); in contrast, 147 (58%) were negative for HBsAg but positive for anti-HCV antibody (group II), 19 (7.5%) were both positive (group Ill), and 19 (7.5%) were both negative (group IV). To evaluate the serial changes in the prevalence of HBsAg and anti-HCV antibody, changes in the number of patients were compared between group I and group II. The number of group I patients reached a peak during 1982–84 and was thereafter followed by a decreasing trend, whereas the number of group ll patients steadlly increased and reached a plateau over 6 recent years. These results suggest that HCV infection recently seems to play a more important role in the development of HCC than chronic HBV infection, even in the Nagasaki Prefecture, where the HBV carrier rate is higher than elsewhere in Japan. © 1993 Wiley-Liss, Inc. 相似文献
67.
Daniele Borsetto Jonathan M. Fussey Diego Cazzador Joel Smith Andrea Ciorba Stefano Pelucchi Sara Don Paolo Boscolo‐Rizzo Michele Tomasoni Davide Lombardi Piero Nicolai Elisabetta Zanoletti Roberta Colangeli Enzo Emanuelli Max S. Osborne Syed F. Ahsan Margherita Tofanelli Giancarlo Tirelli Katherine McNamara Leonard Liew Katherine Harrison Ambrogio Fassina Samantha Sarcognato Neil Sharma Kanishka Rao Paul Pracy Paul Nankivell 《Head & neck》2020,42(3):522-529
68.
Massimo Cardillo Nicola De Fazio Paola Pedotti Tullia De Feo Luigi Rainero Fassati Vincenzo Mazzaferro Michele Colledan Bruno Gridelli Lucio Caccamo Luciano DeCarlis Umberto Valente Enzo Andorno Mariangelo Cossolini Cristiano Martini Adelmo Antonucci Umberto Cillo Giacomo Zanus Umberto Baccarani Mario Scalamogna 《Liver transplantation》2006,12(3):402-410
A specific split liver transplantation (SLT) program has been pursued in the North Italian Transplant program (NITp) since November 1997. After 5 yr, 1,449 liver transplants were performed in 7 transplant centers, using 1,304 cadaveric donors. Whole liver transplantation (WLT) and SLT were performed in 1,126 and 323 cases, respectively. SLTs were performed in situ as 147 left lateral segments (LLS), 154 right trisegment liver (RTL) grafts, and 22 modified split livers (MSL), used for couples of adult recipients. After a median posttransplant follow-up of 22 months, SLTs achieved a 3-yr patient and graft survival not significantly different from the entire series of transplants (79.4 and 72.2% vs. 80.6 and 74.9%, respectively). Recipients receiving a WLT or a LLS showed significantly better outcomes than patients receiving RTL and MSL (P < 0.03 for patients and P < 0.04 for graft survival). At the multivariate analysis, donor age of >60 yr, RTL transplant, <50 annual transplants volume, urgent transplantation (United Network for Organ Sharing (UNOS) status I and IIA), ischemia time of >7 hours, and retransplantation were factors independently related to graft failure and to significantly worst patient survival. Right grafts procured from RTL and either split procured as MSL had a similar outcome of marginal whole livers. In conclusion, in 5 yr, the increased number of pediatric transplants due to split liver donation reduced to 3% the in-list children mortality, and a decrease in the adult patient dropout rate from 27.2 to 16.2% was observed. Such results justify a more widespread adoption of SLT protocols, organizational difficulties not being a limit for the application of such technique. 相似文献
69.
Increased prevalence of peripheral arterial disease in osteoporotic postmenopausal women 总被引:2,自引:0,他引:2
Mangiafico RA Russo E Riccobene S Pennisi P Mangiafico M D'Amico F Fiore CE 《Journal of bone and mineral metabolism》2006,24(2):125-131
The aim of this study was to investigate the prevalence and correlates of peripheral arterial disease (PAD) in a population
of osteoporotic postmenopausal women. The presence of PAD was assessed by ankle brachial index (ABI) in 345 ambulatory osteoporotic
postmenopausal women, and in 360 community-based, age- and race-matched postmenopausal women with normal bone mineral density
(BMD) (control group). PAD was detected in 63/345 (18.2%) osteoporotic women and in 14/360 (3.8%) control subjects (P < 0.0001). The mean ABI values were significantly lower in the osteoporosis group than in the control group (0.98 ± 0.09
vs. 1.04 ± 0.06, P < 0.0001). No difference in cardiovascular risk factors was observed between osteoporotic patients and controls, or between
osteoporotic patients with and without PAD. Osteoporotic patients with PAD had lower femoral neck BMD T scores than those without PAD (−4.2 ± 0.7 vs. −2.3 ± 0.7, P < 0.0001). Only 4 PAD patients (5.1%) had intermittent claudication. In multivariate logistic regression analysis, factors
independently associated with PAD within osteoporotic patients were lower femoral neck BMD T score (odds ratio (OR) = 0.20, 95% confidence interval (CI), 0.05–0.70, P = 0.01) and systolic blood pressure (OR = 1.02, 95% CI, 1.00–1.03, P = 0.01). This study shows for the first time an increased prevalence of PAD among osteoporotic postmenopausal women, with
a lower femoral neck BMD T score being a significant independent predictor. The findings suggest that vascular status evaluation should be done in osteoporotic
postmenopausal women in order to identify candidate patients for preventive and therapeutic cardiovascular interventions. 相似文献
70.
Feasibility and limits of split liver transplantation from pediatric donors: an italian multicenter experience 下载免费PDF全文
Cescon M Spada M Colledan M Torre G Andorno E Valente U Rossi G Reggiani P Cillo U Baccarani U Grazi GL Tisone G Filipponi F Rossi M Ettorre GM Salizzoni M Cuomo O De Feo T Gridelli B 《Annals of surgery》2006,244(5):805-814
OBJECTIVE: To report the results of a multicenter experience of split liver transplantation (SLT) with pediatric donors. SUMMARY BACKGROUND DATA: There are no reports in the literature regarding pediatric liver splitting; further; the use of donors weighing <40 kg for SLT is currently not recommended. METHODS: From 1997 to 2004, 43 conventional split liver procedures from donors aged <15 years were performed. Nineteen donors weighing < or =40 kg and 24 weighing >40 kg were used. Dimensional matching was based on donor-to-recipient weight ratio (DRWR) for left lateral segment (LLS) and on estimated graft-to-recipient weight ratio (eGRWR) for extended right grafts (ERG). In 3 cases, no recipient was found for an ERG. The celiac trunk was retained with the LLS in all but 1 case. Forty LLSs were transplanted into 39 children, while 39 ERGs were transplanted into 11 children and 28 adults. RESULTS: Two-year patient and graft survival rates were not significantly different between recipients of donors < or =40 kg and >40 kg, between pediatric and adult recipients, and between recipients of LLSs and ERGs. Vascular complication rates were 12% in the < or =40 kg donor group and 6% in the >40 kg donor group (P = not significant). There were no differences in the incidence of other complications. Donor ICU stay >3 days and the use of an interposition arterial graft were associated with an increased risk of graft loss and arterial complications, respectively. CONCLUSIONS: Splitting of pediatric liver grafts is an effective strategy to increase organ availability, but a cautious evaluation of the use of donors < or =40 kg is necessary. Prolonged donor ICU stay is associated with poorer outcomes. The maintenance of the celiac trunk with LLS does not seem detrimental for right-sided grafts, whereas the use of interposition grafts for arterial reconstruction should be avoided. 相似文献