全文获取类型
收费全文 | 1605篇 |
免费 | 207篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 108篇 |
妇产科学 | 123篇 |
基础医学 | 267篇 |
口腔科学 | 31篇 |
临床医学 | 131篇 |
内科学 | 545篇 |
皮肤病学 | 47篇 |
神经病学 | 99篇 |
特种医学 | 24篇 |
外科学 | 117篇 |
综合类 | 13篇 |
一般理论 | 2篇 |
预防医学 | 60篇 |
眼科学 | 13篇 |
药学 | 47篇 |
肿瘤学 | 173篇 |
出版年
2023年 | 10篇 |
2022年 | 19篇 |
2021年 | 34篇 |
2020年 | 31篇 |
2019年 | 42篇 |
2018年 | 61篇 |
2017年 | 48篇 |
2016年 | 47篇 |
2015年 | 31篇 |
2014年 | 45篇 |
2013年 | 56篇 |
2012年 | 91篇 |
2011年 | 96篇 |
2010年 | 48篇 |
2009年 | 34篇 |
2008年 | 83篇 |
2007年 | 77篇 |
2006年 | 64篇 |
2005年 | 92篇 |
2004年 | 84篇 |
2003年 | 76篇 |
2002年 | 64篇 |
2001年 | 36篇 |
2000年 | 39篇 |
1999年 | 44篇 |
1998年 | 20篇 |
1997年 | 14篇 |
1996年 | 20篇 |
1995年 | 15篇 |
1994年 | 14篇 |
1992年 | 28篇 |
1991年 | 24篇 |
1990年 | 20篇 |
1989年 | 9篇 |
1988年 | 22篇 |
1987年 | 21篇 |
1986年 | 32篇 |
1985年 | 20篇 |
1984年 | 17篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1979年 | 14篇 |
1978年 | 8篇 |
1977年 | 14篇 |
1974年 | 11篇 |
1973年 | 12篇 |
1971年 | 10篇 |
1969年 | 9篇 |
1968年 | 8篇 |
排序方式: 共有1813条查询结果,搜索用时 0 毫秒
141.
142.
Pain and cachexia are two of the most debilitating aspects of rheumatoid arthritis. Despite that, the mechanisms by which they are mediated are not well understood. We provide evidence that nerve growth factor (NGF), a secreted regulatory protein that controls neuronal survival during development, is a key mediator of pain and weight loss in auto-immune arthritis. Function blocking antibodies to NGF completely reverse established pain in rats with fully developed arthritis despite continuing joint destruction and inflammation. Likewise, these antibodies reverse weight loss while not having any effect on levels of the pro-cachectic agent tumor necrosis factor (TNF). Taken together, these findings argue that pathological joint pain and joint destruction are mechanistically independent processes and that NGF regulates an alternative cachexia pathway that is independent or downstream of TNF. 相似文献
143.
Bruck R Genina O Aeed H Alexiev R Nagler A Avni Y Pines M 《Hepatology (Baltimore, Md.)》2001,33(2):379-386
Hepatic fibrosis is associated with activation of hepatic stellate cells (HSC), the major source of the extracellular matrix (ECM) proteins. The predominant ECM protein synthesized by the HSC is collagen type I. We evaluated the effect of halofuginone-an inhibitor of collagen synthesis-on thioacetamide (TAA)-induced liver fibrosis in rats. In the control rats the HSC did not express smooth muscle actin, collagen type I gene, or tissue inhibitor of metalloproteinases-2 (TIMP-2), suggesting that they were in their quiescent state. When treated with TAA, the livers displayed large fibrous septa, which were populated by smooth muscle actin-positive cells expressing high levels of the collagen alpha1(I) gene and containing high levels of TIMP-2, all of which are characteristic of advanced fibrosis. Halofuginone given orally before fibrosis induction prevented the activation of most of the stellate cells and the remaining cells expressed low levels of collagen alpha1(I) gene, resulting in low levels of collagen. The level of TIMP-2 was almost the same as in the control livers. When given to rats with established fibrosis, halofuginone caused almost complete resolution of the fibrotic condition. The levels of collagen, collagen alpha1(I) gene expression, TIMP-2 content, and smooth muscle actin-positive cells were as in the control rats. Halofuginone inhibited the proliferation of other cell types of the fibrotic liver in vivo and inhibited collagen production and collagen alpha1(I) gene expression in the SV40-immortalized rat HSC-T6 cells in vitro. These results suggest that halofuginone may become an effective and novel mode of therapy in the treatment of liver fibrosis. 相似文献
144.
Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during
pregnancy. The definition of GDM does not preclude the possibility that unrecognized glucose intolerance may have existed
before the pregnancy, and the definition applies whether insulin, oral antidiabetic agents, or dietary modification is used
for treatment. Approximately 7% of all pregnancies in the United States are complicated by gestational diabetes resulting
in more than 200,000 cases annually, but the prevalence ranges from 1% to 14% of all pregnancies depending on the population
studied and the diagnostic tests used. Despite the better detection of GDM and recognition of its adverse consequences for
mother and baby in many countries, there is still no consensus regarding GDM pathophysiology; as a result, diagnosis and treatment
of GDM remain controversial. A better understanding of obesity along with new studies in GDM has identified the intra-abdominal
metabolically active adipose tissue as a major factor in the pathophysiology of GDM. This review examines recent research
regarding the link between obesity and glucose intolerance and highlights studies in the areas of genetics, glucose transport,
and adipokines. 相似文献
145.
Diav-Citrin O Shechtman S Halberstadt Y Finkel-Pekarsky V Wajnberg R Arnon J Di Gianantonio E Clementi M Ornoy A 《Reproductive toxicology (Elmsford, N.Y.)》2011,31(4):540-545
ObjectiveTo examine first trimester safety of angiotensin-converting-enzyme-inhibitors (ACEIs) or angiotensin-receptor-blockers (ARBs).Study designProspective observational cohort regarding pregnancy ACEI/ARBs-exposure including contacts to two Teratology Information Services in Israel (1994–2007) and Italy (1990–2008), with two comparison groups: (1) exposed to other antihypertensives (OAH) (2) after non-teratogenic exposure (NTE) in similar time frames.Results252 ACEI/ARBs-exposed, 256 OAH-exposed and 495 NTE-exposed pregnancies were followed-up. The rate of major congenital anomalies was comparable between the groups (8/190, 4.2%, ACEI/ARB; 9/212, 4.2%, OAH; 18/471, 3.8% NTE; p = 0.954) among first trimester exposed pregnancies. The median gestational age at delivery was two weeks earlier, rate of preterm deliveries more than 2-fold higher, and median birth weight more than 200 g lower in the ACEI/ARB and OAH groups compared to the NTE group.ConclusionThe present study suggests that ACEI/ARBs are not major teratogens when used in the first trimester, and can reassure women with similar exposures. 相似文献
146.
Age-related changes in salivary antioxidant profile: possible implications for oral cancer 总被引:1,自引:0,他引:1
Hershkovich O Shafat I Nagler RM 《The journals of gerontology. Series A, Biological sciences and medical sciences》2007,62(4):361-366
Oral cancer's much higher prevalence among older people may be due to an age-related reduction in protective salivary antioxidant mechanisms and/or an age-related increase in the magnitude of oral carcinogen attack, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), causing DNA aberrations. This study found a significantly reduced total value of salivary antioxidant capacity in elderly persons (as measured by overall antioxidant capacity [ImAnOx] assay), (46% of healthy individuals, p =.004), increased oxidative stress (86% increase in carbonyl concentrations--indicators of enhanced ROS attack, p =.001), and increased salivary concentrations and total values of RNS (7-fold and 3-fold higher respectively, p =.001), all contributing to increased DNA oxidation of oral epithelial cells. Salivary oxidative stress-related changes in the intimately related saliva and oral epithelium compounded with higher viscosity of saliva may explain the higher prevalence of oral cancer in the elderly population. Administration of local therapeutic agents (i.e., antioxidants) to the oral cavity should be considered. 相似文献
147.
Blum A Kryuger K Mashiach Eizenberg M Tatour S Vigder F Laster Z Front E 《European Journal of Internal Medicine》2007,18(4):295-298
BackgroundPeriodontitis is a chronic, infectious, insidious disease of the tooth-supporting structures that causes a general inflammatory response. The aims of this study were to determine whether periodontitis is associated with endothelial dysfunction leading to cardiovascular events and whether proper management of periodontal disease would improve endothelial function and prevent cardiovascular events in the future.MethodsTwenty-two patients (12 women, 10 men; 40 ± 5 years old) took part in the study. All had severe periodontitis (without systemic disorders) and were all treated conservatively. Thirteen patients returned for a second visit after 3 months of treatment. Endothelial function and periodontal status were evaluated on entry into the study and 3 months following treatment. Ten age-matched, healthy volunteers without periodontal disease served as the control group.ResultsThere was a significant difference between the patient group and the healthy controls: FMD% 4.12 ± 3.96 vs. 16.60 ± 7.86% (p = 0.0000). Periodontitis improved significantly in all 13 patients who completed 3 months of treatment, and their endothelial function improved as well: FMD% 4.12 ± 3.96% vs. 11.12 ± 7.22% (p = 0.007). No difference was found in FID% before and after 3 months of treatment: 20.97 ± 10.66% vs.17.94 ± 6.23% (p = NS).ConclusionsPeriodontitis may be an insidious cause of endothelial dysfunction and cardiovascular events. Treating periodontitis can improve endothelial function and be an important preventive tool for cardiovascular disease. 相似文献
148.
A large percentage of older people suffer from chronic insomnia, affecting many aspects of life quality and well-being. Although insomnia is most often treated with medication, a growing number of studies demonstrate the efficiency of various relaxation techniques. The present study had three aims: first, to compare two relaxation techniques--music relaxation and progressive muscular relaxation--on various objective and subjective measures of sleep quality; second, to examine the effect of these techniques on anxiety and depression; and finally, to explore possible relationships between the efficiency of both techniques and personality variables. Fifteen older adults took part in the study. Following one week of base-line measurements of sleep quality, participants followed one week of music relaxation and one week of progressive muscular relaxation before going to sleep. Order of relaxation techniques was controlled. Results show music relaxation was more efficient in improving sleep. Sleep efficiency was higher after music relaxation than after progressive muscular relaxation. Moreover, anxiety was lower after music relaxation. Progressive muscular relaxation was related to deterioration of sleep quality on subjective measures. Beyond differences between the relaxation techniques, extraverts seemed to benefit more from both music and progressive muscular relaxation. The advantage of non-pharmacological means to treat insomnia, and the importance of taking individual differences into account are discussed. 相似文献
149.
150.