全文获取类型
收费全文 | 3651篇 |
免费 | 211篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 267篇 |
妇产科学 | 53篇 |
基础医学 | 444篇 |
口腔科学 | 104篇 |
临床医学 | 357篇 |
内科学 | 821篇 |
皮肤病学 | 97篇 |
神经病学 | 451篇 |
特种医学 | 463篇 |
外国民族医学 | 20篇 |
外科学 | 243篇 |
综合类 | 51篇 |
预防医学 | 166篇 |
眼科学 | 33篇 |
药学 | 131篇 |
2篇 | |
中国医学 | 1篇 |
肿瘤学 | 225篇 |
出版年
2021年 | 29篇 |
2020年 | 22篇 |
2019年 | 34篇 |
2018年 | 60篇 |
2017年 | 39篇 |
2016年 | 41篇 |
2015年 | 63篇 |
2014年 | 83篇 |
2013年 | 118篇 |
2012年 | 92篇 |
2011年 | 102篇 |
2010年 | 123篇 |
2009年 | 127篇 |
2008年 | 126篇 |
2007年 | 154篇 |
2006年 | 126篇 |
2005年 | 128篇 |
2004年 | 85篇 |
2003年 | 67篇 |
2002年 | 81篇 |
2001年 | 83篇 |
2000年 | 69篇 |
1999年 | 88篇 |
1998年 | 154篇 |
1997年 | 169篇 |
1996年 | 140篇 |
1995年 | 124篇 |
1994年 | 127篇 |
1993年 | 114篇 |
1992年 | 82篇 |
1991年 | 84篇 |
1990年 | 77篇 |
1989年 | 102篇 |
1988年 | 86篇 |
1987年 | 84篇 |
1986年 | 89篇 |
1985年 | 74篇 |
1984年 | 53篇 |
1983年 | 41篇 |
1982年 | 37篇 |
1981年 | 37篇 |
1980年 | 34篇 |
1979年 | 22篇 |
1978年 | 17篇 |
1977年 | 35篇 |
1976年 | 36篇 |
1975年 | 30篇 |
1974年 | 22篇 |
1971年 | 17篇 |
1970年 | 18篇 |
排序方式: 共有3937条查询结果,搜索用时 15 毫秒
1.
JM Martín† L Calduch† C Monteagudo‡ I Molina† D Ramón† V Alonso† E Jordᆠ《Journal of the European Academy of Dermatology and Venereology》2006,20(4):428-431
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified. 相似文献
2.
3.
4.
5.
JM Vilanova J Figueras-Aloy J Roselló G Gómez E Gelpí R Jiménez 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(5):588-592
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF 1-α, TXB2 , PGE2 and PGF2-α in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean ± SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 ± 10.6), and related to the severity of HIE ( p = 0:005): without HIE (50.84 ± 16.4; p = 0:02), mild HIE (80.65 ± 12.64; p ± 0:01) and moderate-severe HIE (178.14 ± 20.5; p < 0:01). The CSF 6-keto-PGF 1-α (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 ± 12.56), but indirectly related to the severity of HIE: without HIE (240.95 ± 28.12; p < 0:01), mild HIE (183.65 ± 30.1; p < 0:01) and moderate-severe HIE (140.55 ± 25.12; p < 0:01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF 1-α . 相似文献
6.
7.
Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma 总被引:9,自引:3,他引:6
Weisenburger DD; Gordon BG; Vose JM; Bast MA; Chan WC; Greiner TC; Anderson JR; Sanger WG 《Blood》1996,87(9):3860-3868
Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study. 相似文献
8.
Inhibition of cap (m7GpppXm)-dependent endonuclease of influenza virus by 4-substituted 2,4-dioxobutanoic acid compounds. 总被引:4,自引:1,他引:3 下载免费PDF全文
9.
Amir Kimia MD John S. Brownstein PhD Karen L. Olson PhD Victor Zak PhD Florence T. Bourgeois MD MPH Kenneth D. Mandl MD MPH 《Academic emergency medicine》2006,13(7):767-773
Background: The Centers for Disease Control and Prevention is incorporating laboratory data into real-time surveillance systems. When normal patterns of laboratory test orders and results are modeled, aberrations can be detected. Because many test orders are available electronically well before results, atypical patterns of test ordering may signal outbreaks.
Objectives: The authors sought to characterize baseline patterns in the ordering and early results of lumbar punctures, motivated by the possibility of using these data for real-time surveillance for early detection of meningitis or encephalitis outbreaks.
Methods: Retrospective cohorts of pediatric emergency department patients at a single hospital (1993–2003) and from the National Hospital and Ambulatory Medical Care Survey (1992–2000) were used for analysis.
Results: Test ordering exhibits seasonal patterns, with monthly peaks in January and August (p < 0.0001). For the hospital cohort, the rate of cerebrospinal fluid pleocytosis exhibits seasonal patterns (p < 0.0001), with a peak from August to October. This is strongly associated with the rate and pattern of clinical neurologic disease (p < 0.0001). A long-term secular decline in daily test ordering is evident, dropping from 5.3 to 2.9 in the hospital sample, and from 371.8 to 185.3 in the national sample (p < 0.001). The long-term rate of pleocytosis has declined (p < 0.0001), though the yield of testing for pleocytosis has improved (p = 0.0104).
Conclusions: Laboratory test patterns correspond with those of clinical disease and are a promising source of surveillance data. Using such data for real-time monitoring requires specific adjustments for patient age, periodicities, and secular trends. 相似文献
Objectives: The authors sought to characterize baseline patterns in the ordering and early results of lumbar punctures, motivated by the possibility of using these data for real-time surveillance for early detection of meningitis or encephalitis outbreaks.
Methods: Retrospective cohorts of pediatric emergency department patients at a single hospital (1993–2003) and from the National Hospital and Ambulatory Medical Care Survey (1992–2000) were used for analysis.
Results: Test ordering exhibits seasonal patterns, with monthly peaks in January and August (p < 0.0001). For the hospital cohort, the rate of cerebrospinal fluid pleocytosis exhibits seasonal patterns (p < 0.0001), with a peak from August to October. This is strongly associated with the rate and pattern of clinical neurologic disease (p < 0.0001). A long-term secular decline in daily test ordering is evident, dropping from 5.3 to 2.9 in the hospital sample, and from 371.8 to 185.3 in the national sample (p < 0.001). The long-term rate of pleocytosis has declined (p < 0.0001), though the yield of testing for pleocytosis has improved (p = 0.0104).
Conclusions: Laboratory test patterns correspond with those of clinical disease and are a promising source of surveillance data. Using such data for real-time monitoring requires specific adjustments for patient age, periodicities, and secular trends. 相似文献
10.