全文获取类型
收费全文 | 9121篇 |
免费 | 612篇 |
国内免费 | 66篇 |
学科分类
医药卫生 | 9799篇 |
出版年
2024年 | 11篇 |
2023年 | 136篇 |
2022年 | 255篇 |
2021年 | 431篇 |
2020年 | 253篇 |
2019年 | 383篇 |
2018年 | 368篇 |
2017年 | 250篇 |
2016年 | 320篇 |
2015年 | 331篇 |
2014年 | 398篇 |
2013年 | 477篇 |
2012年 | 698篇 |
2011年 | 757篇 |
2010年 | 378篇 |
2009年 | 310篇 |
2008年 | 516篇 |
2007年 | 478篇 |
2006年 | 464篇 |
2005年 | 450篇 |
2004年 | 384篇 |
2003年 | 373篇 |
2002年 | 319篇 |
2001年 | 114篇 |
2000年 | 116篇 |
1999年 | 101篇 |
1998年 | 98篇 |
1997年 | 55篇 |
1996年 | 46篇 |
1995年 | 37篇 |
1994年 | 40篇 |
1993年 | 21篇 |
1992年 | 42篇 |
1991年 | 44篇 |
1990年 | 50篇 |
1989年 | 31篇 |
1988年 | 35篇 |
1987年 | 31篇 |
1986年 | 16篇 |
1985年 | 30篇 |
1984年 | 12篇 |
1983年 | 22篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1975年 | 11篇 |
1974年 | 8篇 |
1972年 | 8篇 |
1966年 | 9篇 |
排序方式: 共有9799条查询结果,搜索用时 15 毫秒
11.
To evaluate the correlation between persistent symptoms while stents are in place and final outcome in children with nasolacrimal duct obstruction (NLDO). A retrospective observational case series, with medical record review that included indications for surgery, surgical procedure, presence of symptoms while stents were in place, and final outcome after stent removal. Twenty-eight children with NLDO had nasolacrimal duct stents placed in 42 eyes. Twenty-one of the 42 eyes (50%) had minimal or no signs or symptoms of NLDO while stents were in place, and 18 of 21 (86%) were symptom-free after stent removal. Twenty-one of the 42 eyes (50%) remained symptomatic while stents were in place. Eleven of these 21 eyes (52%) had good outcomes after stent removal. Ten (48%) of these patients had persistent symptoms after stent removal requiring further treatment. The prognosis for a good outcome is excellent if symptoms of NLDO resolve while stents are in place. The prognosis is poorer if symptoms of NLDO persist, but more than half of such patients still have good outcomes. Careful counseling of parents regarding these outcomes should be performed before considering additional interventions. 相似文献
12.
13.
14.
15.
The authors studied the effects of 4-hydroxyandrostene-3,17-dione (4-OHA) on progesterone (P), 17 beta-estradiol (E2), and 20 alpha-hydroxy-4-pregnen-3-one synthesis and pregnenolone accumulation in cultured human midluteal cells. A dose-dependent inhibition with and without human chorionic gonadotropin (hCG) of E2 and P production was observed. The accumulation of pregnenolone was significantly enhanced three to fourfold by 4-OHA in this culture system, as compared with control value. In addition, a sevenfold increase on pregnenolone accumulation was observed in the presence of 4-OHA plus 10 IU of hCG as compared with control values and 2.2-fold as compared with the 4-OHA treatments. These in vitro findings indicate a direct effect of 4-OHA on luteal steroidogenesis. Nevertheless, the suppressive effect of 4-OHA on P and E2 production is located at different sites of the steroidogenic pathway. In addition, the results demonstrate that hCG in the presence of 4-OHA stimulated pregnenolone accumulation, suggesting that the inhibition of P synthesis is in some steps after the formation of pregnenolone. These data indicate that the actions of 4-OHA on P or E2 formation have different inhibitory mechanisms. 相似文献
16.
MD MPHCecilia Albala MD MScMabel Y ez MPh Mat.Sc.Gabriela Salazar MD MPHFernando Vio 《Nutrition Research》1994,14(12):1797-1809
Body composition measured with isotopic dilution was compared with anthropometric measurements. The study was carried out in 47 subjects from both sexes, 65 to 92 years old. Total body water (TBW), anthropometric measurements, and dynamometry were assessed. TBW was significatively higher in men than women and decreased with age. Dynamometry and fatfree mass were well correlated (r=0.73 in males and r=0.58 in females) and significantly different between sexes. A negative correlation was found for dynamometry with age, being significant for women. Linear regression equations to predict TBW from anthropometric measurements in males and females were obtained: Males: TBW(I)=19.349+0.617 weight(kg) — 0.931 mid-arm circumference(cm)+0.122 dynamometry (kg) Females: TBW(l)=−5.531+0.343 weight(kg)-0.213 triceps skinfold (mm)+ 0.148 dynamometry(kg) + 3.424 wrist diameter (cm). This simple model is proposed for use in epidemiological and field studies where other more sophisticated methods can not be applied. 相似文献
17.
Telma T Florêncio Haroldo S Ferreira Jairo C Cavalcante Gabriela R Stux Ana L Sawaya 《European journal of cardiovascular prevention and rehabilitation》2007,14(2):346-348
OBJECTIVE: To test the hypothesis that short stature is associated with abdominal obesity, insulin resistance and lipid profile changes. METHODS: Anthropometric data were collected from 237 women (18-60 years old), residents of a shantytown in Maceió. Biochemical profiles of 60 individuals drawn from this population were determined. RESULTS: Total and low-density lipoprotein (LDL) cholesterol levels and insulin resistance rose with increasing waist : hip circumference ratio, particularly in women. Short, overweight individuals exhibited larger biochemical alterations than overweight individuals of average stature. CONCLUSION: Short stature, when associated with overweight, is a risk factor for increased insulin resistance and alterations in lipid profile. 相似文献
18.
19.
Neodymium: YAG laser treatment of persistent pupillary membrane 总被引:1,自引:0,他引:1
A 16-year-old girl had a cosmetically unappealing persistent iridopupillary membrane in the left eye. Her best corrected visual acuity was 20/60, but this improved to 20/40 with pupillary dilation. Neodymium: YAG laser membranectomy resulted in 20/20 vision. This is the first reported case of persistent pupillary membrane treated with the Neodymium: YAG laser. 相似文献
20.
V. van Casteren P. Leurquin A. Bartelds F. Gurtner V. Massari S. Maurice-Tison A.T. Vega R. Mak 《European journal of epidemiology》1993,9(2):169-175
This study describes a p. year international data collection on the demand pattern for HIV-antibody tests in general practice recorded by 6 sentinel networks in 5 European countries. The purpose of the recording was to evaluate the use of HIV-antibody testing by general practitioners and the demand for testing among the general population. Sentinel networks of general practitioners are a possible and available instrument for monitoring the perception of the HIV-test, and indirectly of the threat of the HIV-epidemic by the public and by the general practitioners (GPs). Differences were found between the countries in the frequency of testing, the person asking the test and the reason for testing. Possible explanatory factors, such as differences in the routine testing of specific groups, differences in the training and in the role of the GP, differences in the characteristics of prevention policy, are discussed. The European comparison also offers the opportunity to reflect on common medical practice in dealing with demands for HIV-tests. 相似文献