全文获取类型
收费全文 | 8009篇 |
免费 | 426篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 186篇 |
妇产科学 | 135篇 |
基础医学 | 1014篇 |
口腔科学 | 188篇 |
临床医学 | 673篇 |
内科学 | 2044篇 |
皮肤病学 | 149篇 |
神经病学 | 685篇 |
特种医学 | 230篇 |
外科学 | 1322篇 |
综合类 | 57篇 |
一般理论 | 6篇 |
预防医学 | 504篇 |
眼科学 | 229篇 |
药学 | 432篇 |
中国医学 | 50篇 |
肿瘤学 | 487篇 |
出版年
2024年 | 8篇 |
2023年 | 83篇 |
2022年 | 230篇 |
2021年 | 402篇 |
2020年 | 200篇 |
2019年 | 288篇 |
2018年 | 352篇 |
2017年 | 221篇 |
2016年 | 214篇 |
2015年 | 228篇 |
2014年 | 383篇 |
2013年 | 428篇 |
2012年 | 716篇 |
2011年 | 679篇 |
2010年 | 388篇 |
2009年 | 320篇 |
2008年 | 510篇 |
2007年 | 508篇 |
2006年 | 452篇 |
2005年 | 435篇 |
2004年 | 363篇 |
2003年 | 354篇 |
2002年 | 300篇 |
2001年 | 39篇 |
2000年 | 25篇 |
1999年 | 38篇 |
1998年 | 46篇 |
1997年 | 33篇 |
1996年 | 25篇 |
1995年 | 21篇 |
1994年 | 11篇 |
1993年 | 17篇 |
1992年 | 14篇 |
1991年 | 14篇 |
1990年 | 9篇 |
1989年 | 6篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有8480条查询结果,搜索用时 15 毫秒
61.
David Saavedra-Perez Yuhamy Curbelo-Peña Jaime Sampson-Davila Sonia Albertos Alejandro Serrano Luis Ibañez Xavier Errando Xavier Perez 《Gastroenterologia y hepatologia》2021,44(7):497-518
Symptomatic uncomplicated diverticular colon disease (SUDCD) is a highly prevalent disease in our setting, which significantly affects the quality of life of patients. Recent changes in understanding the natural history of this disease and technological and pharmacological advances have increased the available options for both diagnosis and treatment. However, consensus regarding the use of these options is scarce and sometimes lacks scientific evidence. The objective of this systematic review is to clarify the existing scientific evidence and analyse the use of the different diagnostic and therapeutic options for SUDCD, comparing their advantages and disadvantages, to finally suggest a diagnostic-therapeutic algorithm for this pathology and, at the same time, propose new research questions. 相似文献
62.
Carlos Escobar Julio Martí-Almor Alejandro Pérez Cabeza M. José Martínez-Zapata 《Revista espa?ola de cardiología》2019,72(4):305-316
Introduction and objectives
To assess the effectiveness of direct oral anticoagulants vs vitamin K antagonists in real-life patients with atrial fibrillation.Methods
A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA statement. The ROBINS-I tool was used to assess risk of bias.Results
A total of 27 different studies publishing data in 30 publications were included. In the studies with a follow-up up to 1 year, apixaban (HR, 0.93; 95%CI, 0.71-1.20) and dabigatran (HR, 0.95; 95%CI, 0.80-1.13) did not significantly reduce the risk of ischemic stroke vs warfarin, whereas rivaroxaban significantly reduced this risk (HR, 0.83; 95%CI, 0.73-0.94). Apixaban (HR, 0.66; 95%CI, 0.55-0.80) and dabigatran (HR, 0.83; 95%CI, 0.70-0.97) significantly reduced the major bleeding risk vs warfarin, but not rivaroxaban (HR, 1.02; 95%CI, 0.95-1.10), although with a high statistical heterogeneity among studies. Apixaban (HR, 0.56; 95%CI, 0.42-0.73), dabigatran (HR, 0.45; 95%CI, 0.39-0.51), and rivaroxaban (HR, 0.66; 95%CI, 0.49-0.88) significantly reduced the risk of intracranial bleeding vs warfarin. Reduced doses of direct oral anticoagulants were associated with a slightly better safety profile, but with a marked reduction in stroke prevention effectiveness.Conclusions
Data from this meta-analysis suggest that, vs warfarin, the stroke prevention effectiveness and bleeding risk of direct oral anticoagulants may differ in real-life patients with atrial fibrillation. 相似文献63.
Associations of chemokine system polymorphisms with clinical outcomes and treatment responses of chronic hepatitis C 总被引:21,自引:0,他引:21
Promrat K McDermott DH Gonzalez CM Kleiner DE Koziol DE Lessie M Merrell M Soza A Heller T Ghany M Park Y Alter HJ Hoofnagle JH Murphy PM Liang TJ 《Gastroenterology》2003,124(2):352-360
BACKGROUND & AIMS: CCR5Delta32, a 32-base pair deletion of the CC chemokine receptor (CCR) 5 gene, is associated with slowed human immunodeficiency virus disease progression in heterozygotes and protection against infection in homozygotes. A recent study found a higher than expected frequency of CCR5Delta32/Delta32 in patients with hepatitis C virus infection. The roles of other disease-associated chemokine system polymorphisms have not been evaluated in hepatitis C virus infection. METHODS: Six chemokine system polymorphisms (CCR5Delta32, CCR5 promoter 59029-G/A, CCR2 -64I, RANTES [regulated upon activation, normal T cells expressed and secreted] -403 -G/A, and -28 -C/G and stromal derived factor 1 -3'A) were studied in 417 patients with liver diseases (339 with hepatitis C) and 2380 blood donors. The clinical parameters of hepatitis C virus infection were compared between carriers and noncarriers of each genetic variant. RESULTS: The frequency of CCR5Delta32 homozygosity was 0.8% in whites with hepatitis C virus and 1.1% in controls (P = 0.75). The CCR5Delta32 allele was not associated with any of the clinical parameters of hepatitis C virus infection. Hepatitis C virus-seropositive whites with the RANTES -403-A allele were less likely to have severe hepatic inflammation compared with those without (odds ratio, 0.34; P = 0.03). In multivariate analysis, the CCR5 promoter 59029 -A allele was marginally associated with a sustained response to interferon therapy (odds ratio, 3.07; P = 0.048). CONCLUSIONS: In this cohort, the frequency of CCR5Delta32 homozygosity in patients with hepatitis C was similar to controls. The high prevalence of CCR5Delta32 homozygosity in the hepatitis C virus patients of the earlier study likely reflects resistance to human immunodeficiency virus infection in hemophiliacs rather than a susceptibility to hepatitis C virus infection. Expression of CCR5 and RANTES may be important in the modulation of hepatic inflammation and response to interferon therapy in chronic hepatitis C. 相似文献
64.
65.
A strategy to improve treatment‐related mortality and abandonment of therapy for childhood ALL in a developing country reveals the impact of treatment delays 下载免费PDF全文
Amaranto Suarez MD Martha Piña MD Diana X. Nichols‐Vinueza MD John Lopera MD Lyda Rengifo MD Mauricio Mesa MD Marcela Cardenas RN Lisa Morrissey RN Galo Veintemilla MD Martha Vizcaino MD Ligia Del Toro MD Victor Vicuna PhD Jorge Fernandez LICSW Donna Neuberg ScD Kristen Stevenson MS Alejandro Gutierrez MD 《Pediatric blood & cancer》2015,62(8):1395-1402
Background
Treatment‐related mortality and abandonment of therapy are major barriers to successful treatment of childhood acute lymphoblastic leukemia (ALL) in the developing world.Procedure
A collaboration was undertaken between Instituto Nacional de Cancerologia (Bogota, Colombia), which serves a poor patient population in an upper‐middle income country, and Dana‐Farber/Boston Children's Cancer and Blood Disorders Center (Boston, USA). Several interventions aimed at reducing toxic deaths and abandonment were implemented, including a reduced‐intensity treatment regimen and a psychosocial effort targeting abandonment. We performed a cohort study to assess impact.Results
The Study Population comprised 99 children with ALL diagnosed between 2007 and 2010, and the Historic Cohort comprised 181 children treated prior to the study interventions (1995–2004). Significant improvements were achieved in the rate of deaths in complete remission (13% to 3%; P = 0.005), abandonment (32% to 9%; P < 0.001), and event‐free survival with abandonment considered an event (47% to 65% at 2 years; P = 0.016). However, relapse rate did not improve. Medically unnecessary treatment delays were common, and landmark analysis revealed that initiating the PIII phase of therapy ≥4 weeks delayed predicted markedly inferior disease‐free survival (P = 0.016). Conversely, patients who received therapy without excessive delays had outcomes approaching those achieved in high‐income countries.Conclusions
Implementation of a twinning program was followed by reductions in abandonment and toxic deaths, but relapse rate did not improve. Inappropriate treatment delays were common and strongly predicted treatment failure. These findings highlight the importance of adherence to treatment schedule for effective therapy of ALL. Pediatr Blood Cancer 2015;62:1395–1402. © 2015 Wiley Periodicals, Inc. 相似文献66.
Soza A Heller T Ghany M Lutchman G Jake Liang T Germain J Hsu HH Park Y Hoofnagle JH 《Journal of hepatology》2005,43(1):67-71
BACKGROUND/AIMS: Currently, there are no effective therapies available for patients with chronic hepatitis C who have failed to respond to optimal interferon alfa-based regimens. The aims of this pilot study were to assess the antiviral activity and safety of interferon gamma in chronic hepatitis C. METHODS: Patients with chronic hepatitis C, genotype 1, who had not responded to or who had relapsed after therapy with interferon alfa and ribavirin were enrolled in a trial of interferon gamma 1b given in doses of 100, 200 or 400 microg subcutaneously three times weekly for 4 weeks. Frequent blood samples were obtained for HCV RNA levels. RESULTS: Fourteen patients were enrolled. Geometric mean HCV RNA levels remained unchanged. Serum aminotransferase levels also did not change, while there were significant decreases in neutrophil counts (-41% from baseline) and hematocrit (-5%). Low grade fever and malaise were common with the first injection of interferon gamma, but no serious side effects were encountered. CONCLUSIONS: Although relatively well tolerated, interferon gamma in doses of 100-400 microg thrice weekly had no effect on HCV RNA levels in patients with chronic hepatitis C who had failed to achieve a sustained response to interferon alfa-based therapies. 相似文献
67.
M. de los Ángeles Leal-Felipe M. del Carmen Arroyo-López M. del Cristo Robayna-Delgado Ana Gómez-Espejo Patricia Perera-Díaz Carmen D. Chinea-Rodríguez Natalia García-Correa Alejandro Jiménez-Sosa 《Australian critical care》2018,31(6):355-361
Background
Hospital-acquired pressure injuries are a costly and largely preventable complication occurring in a variety of acute care settings. Patients admitted to the intensive care unit are at greater risk of developing pressure injuries.Objective
To determine whether the efficiency of scales to measure pressure injury risk increase when a continuously updated 3-day moving average method is used.Methods
With a retrospective cohort design we recruited 3085 patients treated between June 2011 and February 2015 in the intensive care unit of a tertiary level university hospital.The present study included 2777 patients admitted to the Intensive Care Unit of the Hospital Universitario de Canarias, Spain.Patients were evaluated daily with two scales to measure pressure injury risk: the Current Risk Assessment Scale for Pressure injury in Intensive Care scale (EVARUCI scale) and the Conscious level-Mobility-Haemodynamics-Oxygenation-Nutrition Index (COMHON). The moving average was used to create a series of three day averages from the complete time-data set. The moving average method was used to analyze data points by creating series of averages of three days subsets of the time-data set. We calculated the efficiency of the method as the product of positive (PPV) and negative predicted values (NPV) for each scale.Results
The efficiency using the moving average method was: PPV x NPV = 0.483 × 0.907 = 0.438 (standard deviation = 0.059), for EVARUCI Scale, and. PPV x NPV = 0.552 × 0.806 = 0.445 (standard deviation = 0.075) for COMHON Index.Conclusions
The efficiency using the moving average method was higher, than the efficiency of other methods previously reported (0.360 ± 0.009 on average). The present study provides a useful procedure for nurses in clinical practice to assess whether a particular patient is protected against the appearance of pressure injury. The instrument should be used focusing on negative predictive value to indicate protection against pressure injury. 相似文献68.
69.
Biagia La Pira Tarun D. Singh Alejandro A. Rabinstein Giuseppe Lanzino 《Mayo Clinic proceedings. Mayo Clinic》2018,93(12):1786-1793
Objective
To analyze trends in mortality rates, functional outcomes, and treatment in patients with aneurysmal subarachnoid hemorrhage (aSAH) over the past 3 decades.Patients and Methods
We conducted a retrospective review of consecutive patients with aSAH treated at Mayo Clinic in Rochester, Minnesota, between January 1, 1985, and December 31, 2014.Results
A total of 1173 patients identified were grouped by decade of treatment: 1985 to 1994, n=274; 1995 to 2004, n=461; and 2005 to 2014, n=438. Overall, the use of endovascular techniques increased progressively from 5.1% (14) in 1985 to 1994 to 65.5% (287) in 2005 to 2014. This corresponded to a progressive decrease in the rate of clipping from 78.8% (216) in 1985 to 2004 to 21.5% (94) in 2005 to 2014 (P<.001). The percentage of patients admitted with poor clinical grade also increased from 22.3% (61) in 1985 to 1994 to 24.1% (111) in 1995 to 2004 and 29.5% (129) in 2005 to 2014 (P=.06). The in-hospital mortality rate decreased from 22.6% (62) in 1985 to 1994 to 16.3% (75) in 1995 to 2004 and remained relatively constant at 16.7% (73) in 2005 to 2014. Good functional outcome at 3- to 6-month follow-up improved significantly from 64.8% (173) in 1985 to 1994 to 72% (332) in 1995 to 2004 and 78.8% (345) in 2005 to 2014 (P<.001).Conclusion
Outcomes in patients with aSAH have markedly improved over the past 3 decades, in terms of both in-hospital survival and functional recovery of survivors. Higher rates of endovascular coiling over time paralleled these improvements in clinical outcomes. More detailed investigation is necessary to determine whether this or other factors may directly explain the favorable trends in survival and functional recovery over time. 相似文献70.
Vitamin D Analogue: Potent Antiproliferative Effects on Cancer Cell Lines and Lack of Hypercalcemic Activity 下载免费PDF全文