全文获取类型
收费全文 | 2301398篇 |
免费 | 168901篇 |
国内免费 | 3390篇 |
专业分类
耳鼻咽喉 | 31796篇 |
儿科学 | 76082篇 |
妇产科学 | 66015篇 |
基础医学 | 338540篇 |
口腔科学 | 64727篇 |
临床医学 | 206905篇 |
内科学 | 446761篇 |
皮肤病学 | 48696篇 |
神经病学 | 182773篇 |
特种医学 | 87621篇 |
外国民族医学 | 605篇 |
外科学 | 340763篇 |
综合类 | 48481篇 |
现状与发展 | 4篇 |
一般理论 | 836篇 |
预防医学 | 181574篇 |
眼科学 | 52654篇 |
药学 | 172415篇 |
8篇 | |
中国医学 | 4098篇 |
肿瘤学 | 122335篇 |
出版年
2018年 | 23028篇 |
2016年 | 19415篇 |
2015年 | 22553篇 |
2014年 | 31160篇 |
2013年 | 47595篇 |
2012年 | 65079篇 |
2011年 | 69581篇 |
2010年 | 40603篇 |
2009年 | 38804篇 |
2008年 | 66340篇 |
2007年 | 71479篇 |
2006年 | 71756篇 |
2005年 | 70362篇 |
2004年 | 67765篇 |
2003年 | 65038篇 |
2002年 | 63764篇 |
2001年 | 100312篇 |
2000年 | 102773篇 |
1999年 | 87153篇 |
1998年 | 25207篇 |
1997年 | 22581篇 |
1996年 | 23048篇 |
1995年 | 21850篇 |
1994年 | 20589篇 |
1993年 | 19069篇 |
1992年 | 70149篇 |
1991年 | 69197篇 |
1990年 | 67914篇 |
1989年 | 65795篇 |
1988年 | 61295篇 |
1987年 | 60171篇 |
1986年 | 57442篇 |
1985年 | 54665篇 |
1984年 | 41219篇 |
1983年 | 35898篇 |
1982年 | 21544篇 |
1981年 | 19372篇 |
1979年 | 39553篇 |
1978年 | 28410篇 |
1977年 | 24129篇 |
1976年 | 22611篇 |
1975年 | 24642篇 |
1974年 | 29500篇 |
1973年 | 28735篇 |
1972年 | 27264篇 |
1971年 | 25411篇 |
1970年 | 23807篇 |
1969年 | 22744篇 |
1968年 | 21334篇 |
1967年 | 19007篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The absence of the temporary incisors could be to a genetic illness or to some multiple premature extractions. These extractions are the aftermaths of the carious lesions or some traumatisms underwent by the temporary incisors. Beyond measure the loss of the space, the premature loss some temporary incisors very often assign the relational development of the child and disturb its psychological development and the aesthetic function. Across some cases clinics, the authors show that the replacement of the temporary incisors is the therapeutic ideal solution. Indeed, the child prosthesis, replacing the temporary absent incisors, solves the psychological, aesthetic and relational problems of the child. 相似文献
102.
The onset of the sporadic Creutzfeldt-Jakob disease is usually characterized by dementia or neurological symptoms. We are reporting the case of a 31 year-old man with a sporadic Creutzfeldt-Jakob disease characterized by a schizophrenia-like onset. The schizophrenic symptoms developed for sixteen months before the neurological symptoms appeared. The psychiatric onset of the present case was linked with the early age of onset and the long duration of the disease and could have been influenced by polymorphism of the codon 129 of the prion protein gene (PRNP) and a type of pathological prion protein (PrPres). 相似文献
103.
The antiepileptic efficacy and tolerability of oxcarbazepine, used both as monotherapy and adjunctive therapy, were observed for 1 year in 202 adult patients, aged 17-83 years, with newly diagnosed or refractory partial epilepsy in clinical practice in Italy. At first observation, the seizure free rate was 72.2% in newly diagnosed patients given monotherapy, 40% in patients in whom oxcarbazepine replaced another monotherapy and 10.3% in patients given oxcarbazepine as adjunctive therapy. At least 50% reduction in seizure frequency was achieved in 90.7, 72 and 57%, respectively. Efficacy increased with the duration of treatment (p < 0.0001). In the 160 completers the seizure free rate was 61.3% with monotherapy and 28% with adjunctive therapy. 16.3% of patients reported adverse effects, mainly sedation and sleepiness; 5% discontinued oxcarbazepine because of adverse events. OXC is an effective and well-tolerated antiepileptic agent for the long-term treatment of partial epilepsy in adults. 相似文献
104.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed. 相似文献
105.
106.
Genomes of some parasites contain dozens of alternative and highly diverged surface antigens, of which only a single one is expressed in any cell. Individual cells occasionally change expression of their surface antigen, allowing them to escape immune surveillance. These switches appear to occur in a partly random way, creating a diverse set of antigenic variants. In spite of this diversity, the parasitemia develops as a series of outbreaks, in which each outbreak is dominated by relatively few antigenic types. Host-specific immunity eventually clears the dominant antigenic types, and a new outbreak follows from antigenic types that have apparently been present all along at low frequency. This pattern of sequential dominance by different antigenic types remains unexplained. We review the five most prominent theories, which have developed mainly from studies of the protozoans Trypanosoma and Plasmodium, and the bacterial spirochete Borrelia. The most promising theories depend on some combination of mechanisms to create favored connectivity pathways through the matrix of transitions between variants. Favored pathways may arise from biased switches at the molecular level of gene expression or from biases imposed by immune selection. We illustrate the concept of connectivity pathways by reanalysis of data on transitions between variants from Borrelia hermsii. 相似文献
107.
O Schouten J H H van Laanen E Boersma R Vidakovic H H H Feringa M Dunkelgrün J J Bax J Koning H van Urk D Poldermans 《European journal of vascular and endovascular surgery》2006,32(1):21-26
OBJECTIVE: To evaluate the effect of statins on aneurysm growth in a group of consecutive patients under surveillance for infrarenal aortic aneurysms (AAA). MATERIALS AND METHODS: All patients (59 statin users, 91 non-users) under surveillance between January 2002 and August 2005 with a follow-up for aneurysm growth of at least 12 months and a minimum of three diameter evaluations were retrospectively included in the analysis. Multiple regression analysis, weighted with the number of observations, was performed to test the influence of statins on AAA growth rate. RESULTS: During a median period of 3.1 (1.1-13.1) years the overall mean aneurysm growth rate was 2.95+/-2.8 mm/year. Statin users had a 1.16 mm/year lower AAA growth rate compared to non-users (95% CI 0.33-1.99 mm/year). Increased age was associated with a slower growth (-0.09 mm/year per year, p = 0.003). Female gender (+1.82 mm/year, p = 0.008) and aneurysm diameter (+0.06 mm/year per mm, p = 0.049) were associated with increased AAA growth. The use of non-steroidal anti-inflammatory drugs, chronic lung disease, or other cardiovascular risk factors were not independently associated with AAA growth. CONCLUSIONS: Statins appear to be associated with attenuation of AAA growth, irrespective of other known factors influencing aneurysm growth. 相似文献
108.
Paul C. Willems Leon Elmans Patricia G. Anderson Wilco C. H. Jacobs Dick B. van der Schaaf Marinus de Kleuver 《European spine journal》2006,15(10):1487-1494
The results of lumbar fusion in chronic low back pain (LBP) patients vary considerably, and there is a need for proper patient selection. Lumbosacral orthoses have been widely used to predict outcome, however, with little scientific support. The aim of the present study was to determine the value of a pantaloon cast test in selecting chronic LBP patients for lumbar fusion or conservative management. First, a systematic review of the literature was carried out in which two independent reviewers identified studies in Medline, Cochrane and Current Contents databases. Three papers met the selection criteria. In the only study with a control group, a significantly better outcome after fusion compared to conservative treatment was found in patients who reported significant pain relief while in a cast (i.e. a positive cast test). The results of lumbar fusion, however, were not significantly different for patients with a positive and those with a negative cast test. In addition to the review, a clinical cohort study of 257 LBP patients, who had been allocated to either lumbar fusion or conservative management by a temporary external transpedicular fixation trial, was performed. Prior to allocation, all had undergone a pantaloon cast test. Patients with no history of prior spine surgery and with a positive pantaloon cast test had a better outcome after lumbar fusion than those treated conservatively (P = 0.002, χ
2 test). In patients with previous spine operations the outcomes were poor and the test was of no value. From the literature and the present patient cohort, it was concluded that only in chronic LBP patients without prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative management. The test has no value in patients who have had previous spine surgery. 相似文献
109.
110.
目的:通过16例经内窥镜及病理证实为Barrett食管的钡餐检查表现,初步探讨Barrett食管及其并发症放射学检查的意义。方法:回顾性分析16例Barrett食管的内窥镜和气钡检查的记录及表现,着重探讨气钡检查的X线表现。结果:食管内窥镜和组织学检查全部病例均有炎症改变,其他可见胃食管反流、食管溃疡和食管腺癌。放射学钡餐检查结果:Barrett食管炎4例,Barrett食管溃疡7例,Barrett食管癌5例。结论:Barrett食管及其并发症至今无明确放射学征象,改进对“Z”线的检查技术和方法,有可能提高其发现率。钡餐发现胃食管反流、食管裂孔疝同时并发食管炎、食管溃疡及食管癌者均应考虑到本症的可能。 相似文献