全文获取类型
收费全文 | 387590篇 |
免费 | 21453篇 |
国内免费 | 15310篇 |
专业分类
耳鼻咽喉 | 3004篇 |
儿科学 | 8705篇 |
妇产科学 | 5922篇 |
基础医学 | 42243篇 |
口腔科学 | 5201篇 |
临床医学 | 42641篇 |
内科学 | 62111篇 |
皮肤病学 | 2854篇 |
神经病学 | 28242篇 |
特种医学 | 16996篇 |
外国民族医学 | 138篇 |
外科学 | 49659篇 |
综合类 | 37219篇 |
现状与发展 | 55篇 |
一般理论 | 19篇 |
预防医学 | 30607篇 |
眼科学 | 9376篇 |
药学 | 31697篇 |
192篇 | |
中国医学 | 12842篇 |
肿瘤学 | 34630篇 |
出版年
2024年 | 570篇 |
2023年 | 3155篇 |
2022年 | 7872篇 |
2021年 | 11448篇 |
2020年 | 8517篇 |
2019年 | 7535篇 |
2018年 | 29167篇 |
2017年 | 23883篇 |
2016年 | 25548篇 |
2015年 | 11081篇 |
2014年 | 13286篇 |
2013年 | 11391篇 |
2012年 | 22704篇 |
2011年 | 38341篇 |
2010年 | 28827篇 |
2009年 | 19413篇 |
2008年 | 30218篇 |
2007年 | 32397篇 |
2006年 | 11661篇 |
2005年 | 13388篇 |
2004年 | 10215篇 |
2003年 | 10805篇 |
2002年 | 7875篇 |
2001年 | 5179篇 |
2000年 | 5736篇 |
1999年 | 5826篇 |
1998年 | 3696篇 |
1997年 | 3675篇 |
1996年 | 2893篇 |
1995年 | 2701篇 |
1994年 | 2234篇 |
1993年 | 1431篇 |
1992年 | 1925篇 |
1991年 | 1676篇 |
1990年 | 1409篇 |
1989年 | 1164篇 |
1988年 | 1064篇 |
1987年 | 894篇 |
1986年 | 736篇 |
1985年 | 553篇 |
1984年 | 353篇 |
1983年 | 261篇 |
1982年 | 173篇 |
1981年 | 145篇 |
1980年 | 150篇 |
1979年 | 144篇 |
1975年 | 62篇 |
1974年 | 75篇 |
1938年 | 64篇 |
1932年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
沙棘汁对致癌物N-二甲基亚硝胺(NDMA)在大鼠体内合成及诱癌的阻断与防护作用 总被引:3,自引:0,他引:3
在饲料中加入氨基比林和NaNO_2各2g/kg饲与Wistar大鼠38周后诱发出肝、肺及肾脏肿瘤,其中以肝肿瘤的发生率为100%(17/17),大鼠平均寿命195天。而同时给予沙棘汁饮用的大鼠其肿瘤发生较晚,发癌率较低(88%,15/17),平均寿命270天,显著长于对照组和单纯抗坏血酸组(P<0.01),且肝脏癌变范围较小,病变较轻。结果表明,沙棘汁能有效地阻断N-亚硝基化合物在大鼠体内合成及诱癌,其防癌效果优于等量的抗坏血酸。 相似文献
992.
Daniel A Rossignol Lanier W Rossignol S Jill James Stepan Melnyk Elizabeth Mumper 《BMC pediatrics》2007,7(1):36
Background
Recently, hyperbaric oxygen therapy (HBOT) has increased in popularity as a treatment for autism. Numerous studies document oxidative stress and inflammation in individuals with autism; both of these conditions have demonstrated improvement with HBOT, along with enhancement of neurological function and cognitive performance. In this study, children with autism were treated with HBOT at atmospheric pressures and oxygen concentrations in current use for this condition. Changes in markers of oxidative stress and inflammation were measured. The children were evaluated to determine clinical effects and safety. 相似文献993.
Background
Cardiovascular disease remains the leading killer of women in most developed areas of the world. Rates of physical inactivity and poor nutrition, which are two of the most important modifiable risk factors for cardiovascular disease in women, are substantial. This study sought to examine the effectiveness of a community-based lifestyle-modification program on increasing women's physical activity in a randomized trial guided by community-based participatory research (CBPR) methods. 相似文献994.
Ann Lecluyse 《The European journal of health economics》2007,8(3):237-243
This paper provides new evidence on the degree of income-related inequality in self-assessed health in Belgium. First of all,
we combine the time dimension, which has been shown to be very important in the analysis of inequality, and the use of the
recently developed interval regression approach to transform a categorical health variable in a continuous one. Second, we
measure how the long-run inequality differs from the short-run inequality. Finally, we decompose this health-related income
mobility index as well as the long-run concentration index (CI) itself into its contributors. Using data from the panel survey
of Belgian households (1994–2002), we find that health is pro-rich distributed and that its inequality is underestimated by
9.45% when neglecting the dynamics of individuals over time. Income, education, job status and age are the most important
contributors in the CI and the difference between the short-run and long-run inequality.
相似文献
995.
We compared the Acrysoft monofocal intraocular lens (IOL) in the mini monovision formula (n = 20) with the Array multifocal intraocular lens (n = 20) for glasses independence after cataract surgery. The Acrysoft monofocal IOL group showed similar and even slightly
better results than the Array multifocal IOL group. The monofocal Acrysoft IOL using the mini monovision (blended vision)
formula is a good alternative for providing post-cataract surgery glasses independence.
Drs. Chen, Clinical Assistant Professor of Ophthalmology and Neal H. Atebara are at University of Hawaii School of Medicine,
Honolulu, Hawaii, USA.
Dr. Te Tsaw Chen, Past Professor & Director, was at Department of Ophthalmology, Taipei Medical University, Taipei, ROC.
The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer
or provider of services discussed in this article. The authors also do not discuss the use of off-label products, which includes
unlabeled, unapproved, or investigative products or devices.
The authors compared the Acrysoft monofocal intraocular lens in the mini monovision formula to the Array multifocal intraocular
lens for glasses independence after cataract surgery. 相似文献
996.
Kamran Sardari Ehsan Galedar Kakhki Mehrdad Mohri 《Comparative clinical pathology》2007,16(3):197-200
Ten bulls (age 7 months, weight 302 ± 15 kg) were used in this study. After sterile preparation of skin, a full thickness
wound (20 × 20 mm) was created in each bull. The bulls were randomly assigned into two groups: group 1 received 6 ml Theranekron
subcutaneously and group 2 penicillin banzatine 10,000 IU/kg IM. These doses were repeated 6 days after initial wounding.
At days 0, 3, 6, 10 and 14, digital photographs were taken from the wounds to calculate wound contraction and epithelialization
using geometry. Chi-square test was performed for statistical analysis using SPSS 9 for Windows. There was no significant
differences in wound contraction between trial groups (P > 0.05) but a statistical difference was seen in epithelialization between groups (P < 0.05). Epithelialization is one of the most important factors in wound healing. According to the results of the present
study, Theranekron can significantly stimulate epithelialization in full thickness wounds in cows during the first 14 days
of healing. 相似文献
997.
Objective: 5-Aminoisoquinolinone, a water-soluble, potent inhibitor of the activity of poly (adenosine 5'-diphosphate ribose) polymerase, plays an important role in the tissue injury associated with ischaemia-reperfusion injury and inflammation by inhibiting the activity of poly (adenosine 5'-diphosphate ribose) polymerase and the expression of cell adhesion molecules such as ICAM-1, P-selectin et al. But how about it in the tumor is not clear. The aim of the present study was to study the effects of 5-Aminoisoquinolinon on the adhesion of colon carcinoma line HT-29 cells to human umbilical vein endothelial cells; and the effects of 5-Aminoisoquinolinon on the expression of ICAM-1, P-selectin and the activity of poly (adenosine 5'-diphosphate ribose) polymerase in colon carcinoma HT-29 cells. Methods: The adhesion of HT-29 cells to human umbilical vein endothelial cells was detected by adhesive experiment. Immunocytochemically Streptavidin-Peroxidase method was used to investigate the expression of ICAM-1, P-selectin and Poly (adenosine 5'-diphosphate ribose)( the product of poly (adenosine 5'-diphosphate ribose) polymerase activation). Results: the results of the adhesion assay of HT-29 cells to HUVEC showed that the OD570 value in each 5-AIQ-treated group was significant lower than that in the control group (5-AIQ-untreated) in a dose-dependent manner. The expression of ICAM-1, P-selectin and Poly (adenosine 5'-diphosphate ribose) was significant lower in 5-Aminoisoquinolinone-treated HT-29 cell group than that in 5-Aminoisoquinolinoneuntreated groups. Conclusion: The data suggest that 5-Aminoisoquinolinone can inhibit the adhesion of HT-29 cells to human umbilical vein endothelial cells. 5-Aminoisoquinolinone also can inhibit poly (adenosine 5'-diphosphate ribose) polymerase activation and the expressions of ICAM-1 and P-selectin in HT-29 cells. 5-Aminoisoquinolinone probably contributes to the prevention of tumor cell metastasis. Further study is needed. 相似文献
998.
从糖尿病合并冠心病的流行病学、病理基础、发病机理及临床、治疗五个方面论述了糖尿病合并冠心病的现代基础研究,并对其中西医结合治疗提出了方法. 相似文献
999.
1000.
本实验观察了0. 25、0. 5、1. 0、2. 0、3. 0和4. 0Gy全身照射后3至6 h羊红细胞(SRBC)免疫对小鼠脾脏抗体形成细胞(PFC)的影响。结果发现,各剂量照射后,免疫与照射的时间间隔较长者,辐射对PFC反应的抑制显著加深。照射后3及6h免疫,脾脏PFC反应均随照射剂量的增加而降低。照射后3h免疫时,PFC反应的D_(37)值为4. 13Gy;照射后6h免疫时,PFC反应的D_(37)值为1. 74Gy。 相似文献