全文获取类型
收费全文 | 3257篇 |
免费 | 233篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 114篇 |
妇产科学 | 97篇 |
基础医学 | 416篇 |
口腔科学 | 120篇 |
临床医学 | 376篇 |
内科学 | 439篇 |
皮肤病学 | 82篇 |
神经病学 | 269篇 |
特种医学 | 228篇 |
外科学 | 270篇 |
综合类 | 73篇 |
一般理论 | 1篇 |
预防医学 | 203篇 |
眼科学 | 106篇 |
药学 | 211篇 |
1篇 | |
肿瘤学 | 374篇 |
出版年
2021年 | 24篇 |
2019年 | 35篇 |
2018年 | 46篇 |
2017年 | 27篇 |
2016年 | 38篇 |
2015年 | 39篇 |
2014年 | 54篇 |
2013年 | 98篇 |
2012年 | 90篇 |
2011年 | 102篇 |
2010年 | 96篇 |
2009年 | 79篇 |
2008年 | 97篇 |
2007年 | 122篇 |
2006年 | 147篇 |
2005年 | 145篇 |
2004年 | 125篇 |
2003年 | 111篇 |
2002年 | 98篇 |
2001年 | 86篇 |
2000年 | 88篇 |
1999年 | 116篇 |
1998年 | 72篇 |
1997年 | 72篇 |
1996年 | 62篇 |
1995年 | 50篇 |
1994年 | 69篇 |
1993年 | 47篇 |
1992年 | 90篇 |
1991年 | 84篇 |
1990年 | 89篇 |
1989年 | 93篇 |
1988年 | 75篇 |
1987年 | 75篇 |
1986年 | 59篇 |
1985年 | 52篇 |
1984年 | 62篇 |
1983年 | 62篇 |
1982年 | 43篇 |
1981年 | 35篇 |
1980年 | 32篇 |
1979年 | 54篇 |
1978年 | 41篇 |
1977年 | 26篇 |
1976年 | 28篇 |
1975年 | 22篇 |
1974年 | 36篇 |
1973年 | 21篇 |
1971年 | 17篇 |
1970年 | 21篇 |
排序方式: 共有3496条查询结果,搜索用时 328 毫秒
1.
D Monnier† C Vidal‡ L Martin§ A Danzon¶ F Pelletier† E Puzenat† MP Algros†† D Blanc† R Laurent† PH Humbert† F Aubin† 《Journal of the European Academy of Dermatology and Venereology》2006,20(10):1237-1242
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating. 相似文献
2.
3.
D J Enscore J L Osborne J E Shaw 《Methods and findings in experimental and clinical pharmacology》1989,11(3):173-178
The in vitro and in vivo functionality of Catapres-TTS, a transdermal therapeutic system that delivers the alpha adrenergic receptor agonist clonidine, is discussed in terms of the drug transport kinetics and resultant plasma drug concentration profiles. The design of Catapres-TTS is presented as an optimization by which the best combination of system performance characteristics is obtained within the inherent limitations of the transdermal drug transport properties and the known pharmacokinetic and pharmacodynamic properties of the drug. Clonidine is a potent antihypertensive agent with a relatively low therapeutic index. For Catapres-TTS, the majority of control over the drug input rate resides within the system, rather than within the skin, which significantly reduces the variability in drug input rate and resulting plasma drug concentration both within and between patients. Moreover, the presence of a rate-control element in the system allows for patterning of the drug release rate. An initial bolus of drug is placed in the contact adhesive layer, where its transport into the skin is not inhibited by the rate control element in the system, for reduction in the time needed to achieve steady state drug input. The selection of the loading dose of drug is described as an optimization between the minimization of the lag time and the maintenance of constant plasma drug concentrations during the crossover period between system applications in chronic therapy. 相似文献
4.
Variation in opinions of medical experts is a problem for both the legal and medical profession. This is particularly relevant in breast imaging. BreastScreen Queensland and New South Wales have developed a review protocol to assess ‘reasonableness’ of radiological opinions. It is hoped that the protocol will be acceptable to the courts and will result in a fair outcome for all parties involved in a medico-legal dispute. 相似文献
5.
The effect of substance P and other tachykinins on inositol phospholipid hydrolysis in rabbit retina, superior colliculus and retinal cultures 总被引:1,自引:0,他引:1
Substance P and eledoisin stimulate the accumulation of inositol phosphates in a dose-dependent manner in retinal and superior colliculus slices of the rabbit. The EC50 values for substance P and eledoisin in both tissues were of the same order (1.5-4.9 microM), suggesting that the receptors in the two tissues were alike with characteristics of the SP-P subtype rather than the SP-E subtype. These data suggest that the SP-immunoreactive material in the retinal ganglion and amacrine cells is identical. The effectiveness for a number of tachykinin substances at 10(-5) M for stimulating inositol phosphates accumulation was as follows: Substance P greater than eledoisin greater than neurokinin A greater than neurokinin B greater than substance P (octapeptide) greater than substance P (pentapeptide). Spantide [(D-Arg1, D-Try7.9, Leu11) substance P] and (D-Pro2, D-Try7.9) substance P did not stimulate inositol phospholipid hydrolysis. However, spantide, at a concentration of 10(-6) M, was an antagonist of the effect produced by substance P, but had no action on the effect produced by neurokinin A or neurokinin B. Substance P and other tachykinins were also effective in stimulating inositol phosphates accumulation in 3-5-day-old rabbit retinal cultures but did not elicit a response in the older (25-30-day-old) cultures which lacked neurones but contained Müller cells. Furthermore, substance P was only active in the younger cultures in stimulating an increase in internal calcium levels. It is therefore concluded that retinal tachykinin receptors linked to phosphoinositide turnover and calcium mobilisation are associated exclusively with neurones and not with Müller cells. 相似文献
6.
Over the past decade, the unfortunate reality is that the income gap has widened between Canadian families. Educational outcomes are one of the key areas influenced by family incomes. Children from low-income families often start school already behind their peers who come from more affluent families, as shown in measures of school readiness. The incidence, depth, duration and timing of poverty all influence a child’s educational attainment, along with community characteristics and social networks. However, both Canadian and international interventions have shown that the effects of poverty can be reduced using sustainable interventions. Paediatricians and family doctors have many opportunities to influence readiness for school and educational success in primary care settings. 相似文献
7.
8.
9.
MP Costi D Tondi M Rinaldi D Barlocco G Cignarella DV Santi C Musiu I Pudu G Vacca P La Colla 《European journal of medicinal chemistry》1996,31(12):1011-1016
A new series of N-(substituted)benzyl-1,8-naphthalimides 4, structurally related to the previously reported thymidylate synthase (TS) inhibitor naphthaleins 3, were synthesized and compounds tested for their inhibition of several species of TS. Moreover, their in vitro cytotoxicity together with antimycotic and antibacterial properties were assayed. While no activity was detected in the antibacterial tests, the m-nitro (4ae) and the p-nitro (4af) derivatives were found able to partially inhibit TS at low micromolar concentrations. Introduction of nitro or (substituted)-amino groups in position 4 of the naphthalic ring always led to less active compounds. 相似文献
10.
Multiple genes encode nuclear factor 1-like proteins that bind to the promoter for 3-hydroxy-3-methylglutaryl-coenzyme A reductase. 总被引:37,自引:1,他引:36
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)