全文获取类型
收费全文 | 2976篇 |
免费 | 254篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 171篇 |
妇产科学 | 26篇 |
基础医学 | 373篇 |
口腔科学 | 51篇 |
临床医学 | 303篇 |
内科学 | 711篇 |
皮肤病学 | 55篇 |
神经病学 | 153篇 |
特种医学 | 251篇 |
外科学 | 435篇 |
综合类 | 58篇 |
预防医学 | 247篇 |
眼科学 | 36篇 |
药学 | 146篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 221篇 |
出版年
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 48篇 |
2020年 | 26篇 |
2019年 | 54篇 |
2018年 | 64篇 |
2017年 | 46篇 |
2016年 | 39篇 |
2015年 | 67篇 |
2014年 | 78篇 |
2013年 | 103篇 |
2012年 | 153篇 |
2011年 | 168篇 |
2010年 | 139篇 |
2009年 | 124篇 |
2008年 | 158篇 |
2007年 | 143篇 |
2006年 | 154篇 |
2005年 | 133篇 |
2004年 | 135篇 |
2003年 | 111篇 |
2002年 | 124篇 |
2001年 | 38篇 |
2000年 | 26篇 |
1999年 | 37篇 |
1998年 | 134篇 |
1997年 | 113篇 |
1996年 | 114篇 |
1995年 | 77篇 |
1994年 | 61篇 |
1993年 | 59篇 |
1992年 | 28篇 |
1991年 | 35篇 |
1990年 | 19篇 |
1989年 | 42篇 |
1988年 | 37篇 |
1987年 | 42篇 |
1986年 | 24篇 |
1985年 | 38篇 |
1984年 | 29篇 |
1983年 | 23篇 |
1982年 | 26篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 6篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1976年 | 17篇 |
1975年 | 13篇 |
1965年 | 5篇 |
排序方式: 共有3248条查询结果,搜索用时 0 毫秒
1.
PJ Commerford 《Cardiovascular journal of Africa》2015,26(4):151-Aug;26(4):151
2.
3.
David M Raffel Robert A Koeppe Roderick Little Chia-Ning Wang Suyu Liu Larry Junck Mary Heumann Sid Gilman 《Journal of nuclear medicine》2006,47(11):1769-1777
Scintigraphic imaging with (123)I-metaiodobenzylguanidine ((123)I-MIBG) has demonstrated extensive losses of cardiac sympathetic neurons in idiopathic Parkinson's disease (IPD). In contrast, normal cardiac innervation has been observed in (123)I-MIBG studies of multiple-system atrophy (MSA) and progressive supranuclear palsy (PSP). Consequently, it has been hypothesized that cardiac denervation can be used to differentiate IPD from MSA and PSP. We sought to test this hypothesis by mapping the distribution of cardiac sympathetic neurons in patients with IPD, MSA, and PSP by using PET and (11)C-meta-hydroxyephedrine ((11)C-HED). Also, the relationship between cardiac denervation and nigrostriatal denervation was investigated by measuring striatal presynaptic monoaminergic nerve density with PET and (11)C-dihydrotetrabenazine ((11)C-DTBZ). METHODS: (11)C-HED and (11)C-DTBZ scans were obtained for patients with IPD (n = 9), MSA (n = 10), and PSP (n = 8) and for age-matched control subjects (n = 10). Global and regional measurements of (11)C-HED retention were obtained to assess the extent of cardiac sympathetic denervation. (11)C-DTBZ binding was measured in the caudate nucleus, anterior putamen, and posterior putamen. RESULTS: As expected, extensive cardiac denervation was observed in several of the patients with IPD. However, substantial cardiac denervation was also seen in some patients with MSA and PSP. (11)C-DTBZ studies demonstrated striatal denervation in all patients with IPD and in most patients with MSA and PSP. No correlation was found between cardiac (11)C-HED retention and striatal (11)C-DTBZ binding. CONCLUSION: Cardiac sympathetic denervation was found to occur not only in IPD but also in other movement disorders, such as MSA and PSP. This finding implies that scintigraphic detection of cardiac sympathetic denervation cannot be used independently to discriminate IPD from other movement disorders, such as MSA and PSP. Cardiac sympathetic denervation was not correlated with striatal denervation, suggesting that the pathophysiologic processes underlying cardiac denervation and striatal denervation occur independently in patients with parkinsonian syndromes. These findings provide novel information about central and peripheral denervation in patients with neurodegenerative disorders. 相似文献
4.
Paul Roderick Ruth Davies Chris Jones Terry Feest Steve Smith Ken Farrington 《Nephrology, dialysis, transplantation》2004,19(3):692-701
BACKGROUND: The demand for renal replacement therapy (RRT) in England has risen steadily, although from a lower base than many other developed countries. Predicting the future demand for RRT and the impact of factors such as the acceptance rate, transplant supply and patient survival, is required in order to inform the planning of such services. METHODS: A discrete event simulation model estimates the future demand for RRT in England in 2010 for a range of scenarios. The model uses current prevalence and current and projected future acceptance rates, survival rates and the transitions between modalities to predict future patient numbers. National population and mortality data, published literature and data from the UK Renal Registry and UK Transplant, are used to estimate unmet need for RRT, the impact of changing demography and incidence of Type 2 diabetes, patient haemodialysis (HD) survival and transplant supply. RESULTS: By 2010 the predicted prevalence will have increased from about 30,000 in 2000 to between 42 and 51,000 (900-1000 p.m.p.), an average annual growth of 4.5-6%. Changing transplant supply has a small effect on overall numbers but changes the proportion of patients with functioning graft by up to 8%. Even with an optimistic increase in transplant supply (11% p.a. for 5 years), numbers on HD will continue to rise substantially, especially in the elderly. The factors most influencing future patient numbers are the acceptance rate and dialysis survival. CONCLUSION: This model predicts a substantial growth in the RRT population to 2010 to a rate approaching 1000 p.m.p., particularly in the elderly and those on HD, with a steady state not being reached for at least 25 years. 相似文献
5.
6.
7.
Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease. 相似文献
8.
9.
10.
Uroscopy in the 21st century: high-field NMR spectroscopy 总被引:1,自引:1,他引:0
Neild GH; Foxall PJ; Lindon JC; Holmes EC; Nicholson JK 《Nephrology, dialysis, transplantation》1997,12(3):404-417
From the experiments described, it can be seen that there are different
research approaches that can be taken and these are summarized in Table 1.
Whereas much scientific research is principally hypothesis led, there
remains, nevertheless, an important place for exploratory research. High
resolution NMR can measure, directly and simultaneously, a wide range of
endogenous metabolites in biological fluids and has the unique capability
of providing structural information on the metabolites detected. It has
proved to be a powerful research tool with which to study inherited
metabolic diseases, renal disease, drug metabolism, and toxicity, and can
be used to monitor the effects of drug therapy. For instance, by using a
library of experimental toxins one can map the metabolic profile of
site-specific nephron injury. With this approach in man one could
eventually take an unknown disease such as Balkan nephropathy and predict
the initial site of tubular injury, the mode of injury and therefore the
kind of toxin capable of producing that injury. NMR spectroscopic
techniques are still advancing rapidly, with ever increasing sensitivity
and sophistication of NMR pulse sequences to enhance structural elucidation
in complex mixtures. Given the advances in directly coupled HPLC-NMR and
even HPLC-NMR-mass spectroscopy it is likely that these technologies in
conjunction with pattern recognition will make major contribution to our
understanding of renal processes and provide new diagnostic insights in the
21st century.
相似文献