全文获取类型
收费全文 | 54087篇 |
免费 | 3653篇 |
国内免费 | 266篇 |
专业分类
耳鼻咽喉 | 522篇 |
儿科学 | 1928篇 |
妇产科学 | 1392篇 |
基础医学 | 8090篇 |
口腔科学 | 823篇 |
临床医学 | 5216篇 |
内科学 | 12258篇 |
皮肤病学 | 1178篇 |
神经病学 | 5911篇 |
特种医学 | 1141篇 |
外科学 | 4392篇 |
综合类 | 307篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 5073篇 |
眼科学 | 869篇 |
药学 | 4086篇 |
中国医学 | 136篇 |
肿瘤学 | 4640篇 |
出版年
2024年 | 91篇 |
2023年 | 684篇 |
2022年 | 1444篇 |
2021年 | 2438篇 |
2020年 | 1400篇 |
2019年 | 1798篇 |
2018年 | 1977篇 |
2017年 | 1604篇 |
2016年 | 1757篇 |
2015年 | 1908篇 |
2014年 | 2480篇 |
2013年 | 3111篇 |
2012年 | 4579篇 |
2011年 | 4578篇 |
2010年 | 2428篇 |
2009年 | 2072篇 |
2008年 | 3466篇 |
2007年 | 3460篇 |
2006年 | 3126篇 |
2005年 | 2837篇 |
2004年 | 2628篇 |
2003年 | 2338篇 |
2002年 | 2112篇 |
2001年 | 251篇 |
2000年 | 193篇 |
1999年 | 262篇 |
1998年 | 336篇 |
1997年 | 288篇 |
1996年 | 194篇 |
1995年 | 186篇 |
1994年 | 184篇 |
1993年 | 145篇 |
1992年 | 113篇 |
1991年 | 97篇 |
1990年 | 87篇 |
1989年 | 98篇 |
1988年 | 90篇 |
1987年 | 86篇 |
1986年 | 73篇 |
1985年 | 68篇 |
1984年 | 92篇 |
1983年 | 73篇 |
1982年 | 80篇 |
1981年 | 71篇 |
1980年 | 65篇 |
1979年 | 37篇 |
1978年 | 46篇 |
1977年 | 38篇 |
1976年 | 28篇 |
1973年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Sheetal Chopra Anna S Lev-Toaff Fatih Ors Diane Bergin 《Journal of ultrasound in medicine》2006,25(5):617-27; quiz 629
OBJECTIVE: The purpose of this presentation is to show the imaging findings of the common and uncommon variants of adenomyosis as seen on sonography and magnetic resonance imaging (MRI). METHODS: A 3-year database search was performed to identify women who had pelvic sonography and pelvic MRI within a 6-month interval. Images of these cases were retrospectively reviewed. RESULTS: Eighty women were identified. Adenomyosis was diagnosed on MRI, which was used as the reference standard, in 45 of these women. The correct diagnosis was made on sonography in 73% of the cases. CONCLUSIONS: Awareness of the spectrum of imaging features of adenomyosis is important to use sonography effectively for diagnosing this entity and to help avoid misdiagnosis. 相似文献
22.
Retention: An unresolved workforce issue affecting rural occupational therapy services 总被引:1,自引:0,他引:1
Failure to retain health professionals in rural areas contributes to the poor health status of these communities through an inability to deliver reliable and consistent services. Considerable attention has been focused on factors affecting recruitment of health professionals. Far less is known about factors affecting the retention of occupational therapists. This was the focus of this study. Ethnographic interviews were used to explore the experiences of 10 occupational therapists who had left rural practice. Six themes emerged from the participants' experiences, from when they first considered rural practice to reflections following their departure from it. These themes were initial appeal, facing the challenge, rural practice issues, the social sphere, reasons for leaving and the value of rural experience. These factors gave rise to a proposed Model of Retention Equilibrium, which suggests that retention can be improved by addressing the imbalance between incentives to leave and incentives to stay. The model provides a useful framework for occupational therapists contemplating rural practice, as well as for health services managers responsible for service delivery in rural areas. 相似文献
23.
Anna Andlin-Sobocki 《Journal of clinical periodontology》1993,20(3):212-218
Abstract Facial gingival surfaces of maxillary and mandibular anterior teeth were monitored to evaluate changes of the width of the keratinized and attached gingiva. 96 children 6 to 12 years of age were examined 2 × with an interval of 2 years. Measurements included dental plaque, gingival inflammation, probing depth, and width of keratinized and attached gingiva. In addition, study models were used to determine the facial/lingual position of the teeth. The results of this report, evaluating well-aligned teeth only, showed that during the 2-year observation period, increases in widths of the facial keratinized and attached gingiva took place. Increases occurred for the various teeth regions examined, and for deciduous as well as permanent teeth. During transition from the deciduous to the permanent dentition, patterns of change were variable. The increase of gingival widths was greatest for sites with the smallest baseline width of attached gingiva, and smallest for sites with the greatest baseline width. It was concluded that in well-aligned teeth, a conservative, monitoring approach prior to a corrective, surgical intervention seems prudent in children of this age with a minimal zone or absence of attached gingiva. 相似文献
24.
Anna I. Suvorova Lyudmila Yu. Demchik Aza L. Peshekhonova Olga A. Sdobnikova 《Macromolecular chemistry and physics.》1993,194(5):1315-1321
The phase equilibrium of plasticized polymer systems on the basis of cellulose diacetate and ethylene glycol esters of dibasic aliphatic acids (from oxalic acid to 1,10-decanedicarboxylic acid) was studied and the solubility parameters and the thermodynamic interaction parameters of the components were calculated. It is shown that an increase in molecular weight of the plasticizers leads to a lower miscibility of the components, a fact which is reflected in a regular rise of the upper critical solution temperature (UCST), a tendency of the systems for gelation, a decrease of the solubility parameter of the plasticizer δ1, and a growth of the interaction parameters χH and χ12. The results are discussed in terms of the existing theories for polymer solutions. 相似文献
25.
Tim Elliott Marc Bonneville Juan Carlos Zúiga-Pflücker Paul R. Walker David Essayan Nicolas Glaichenhaus Anna Vyakarnam Jean-Laurent Casanova Yang Liu Hugh Auchincloss Jr Gerry Waneck Christian LeGuern Cezmi Akdis Allison Green 《Current opinion in immunology》2002,14(6):673
A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology. 相似文献
26.
Angelo Cagnacci Gian Benedetto Melis Renza Soldani Anna Maria Paoletti Marco Gambacciani Adriana Spinetti Piero Fioretti 《Maturitas》1991,13(4):283-296
The neuroendocrine and clinical effects of transdermal 17β-estradiol (rated at 50 μg/day; TTS 50) were studied in 40 postmenopausal women; ten additional postmenopausal women did not receive any drugs. The changes in LH and rectal temperature induced by the infusion of the opioid antagonist naloxone (10 mg i.v. bolus plus 10 mg/h for 4 h) were used to evaluate the central activity of endogenous opioid peptides. TTS 50 increased opioid activity, as evidenced by the restoration of the LH response (P < 0.01) and the enhancement of the hypothermic effect (P < 0.05) of naloxone. A greater reduction in hot flushes was observed in TTS 50-treated subjects than in untreated women, with the maximal effect of TTS 50 achieved after 3 months of therapy. TTS 50 did not modify the concentrations of circulating lipids, glucose or liver enzymes but reduced the biochemical parameters indicative of bone reabsorption. Bone density of the distal radius significantly increased during TTS 50 (P < 0.02), reaching its maximum value after 6 months of therapy. Thereafter bone density declined, but more slowly than in untreated women.
Our data suggest that TTS 50 has marked neuroendocrine effects, that it diminishes the incidence of hot flushes and reduces bone demineralization. By contrast, it has a very little, if any, metabolic impact on the liver or on glucose and lipid metabolism. 相似文献
27.
We evaluated the effectiveness of statewide bicycle legislation using direct observation of the number of elementary and middle school children riding bicycles with and without helmets to or from school over a 7-year period. The percentage of children wearing helmets increased dramatically over the past 7 years (to a high of 81%) due to the passage of state law that required helmet usage. Rates for elementary school children were consistently higher than rates of middle school children. Numerous children still do not wear helmets, particularly older children. Further interventions are needed to promote helmet wearing. 相似文献
28.
David M. Kelley Alan Lichtenstein Jianyi Wang Anna N. Taylor Steven M. Dubinett 《Immunopharmacology and immunotoxicology》1994,16(2):139-148
Previous studies have suggested that corticotropin-releasing factor (CRF) has immunoregulatory effects in addition to its neuroendocrine role. We examined the ability of CRF to inhibit lipopolysaccharide (LPS)-induced pulmonary vascular leak in vivo. Female BALB/C mice were treated with either normal saline (NS) or CRF prior to injection with LPS. Pulmonary vascular leak was inhibited by CRF as assessed by measurement of lung wet-to-dry ratios. The stress-induced increase in serum corticosterone levels in mice injected with LPS alone was not further increased by treatment with CRF. This indicates that the effect of CRF was not mediated centrally by stimulation of endogenous steroid release. Histologic examination of the lungs revealed that leukocyte infiltration was significantly depressed in CRF-treated mice thus confirming the protective effect of CRF. In addition, a modest prolongation of survival was demonstrated in CRF-treated mice following challenge with LPS (p=.08). These data indicate the potential utility of CRF as a modulator of pulmonary vascular leak. 相似文献
29.
Richard B Scott Ralph Gregory Joanna Wilson Sarah Banks Anna Turner Simon Parkin Nir Giladi Carol Joint Tipu Aziz 《Movement disorders》2003,18(5):539-550
Primary dystonia is a disorder of movement for which no consistent pathophysiology has been identified; in the absence of evidence to the contrary, it is assumed to be cognitively benign. We have studied a clinically heterogeneous group of 14 patients with primary dystonia on a battery of neuropsychological tests. Despite well-preserved speed of information processing, language, spatial, memory and general intellectual skills relative to normal controls, we have identified a constellation of attentional-executive cognitive deficits on the Cambridge Neuropsychological Test Automated Battery (CANTAB). Specifically, patients demonstrated significant difficulties negotiating the extra-dimensional set-shifting phase of the IED task. The implications of these findings for the pathophysiology of primary dystonia are discussed. This is, to the best of our knowledge, the first report of a significant cognitive deficit in patients with primary dystonia. 相似文献
30.
Alfonso Fasano Antonio E Elia Arianna Guidubaldi Pietro A Tonali Anna Rita Bentivoglio 《Movement disorders》2007,22(4):564-566
We report a case of cervical dystonia occurring in a 33-year-old without personal history of movement disorder but with family history of essential tremor, primigravid, primiparous woman at 1 weeks' amenorrhea, resolved completely after delivery in the course of 3 months. Dystonia never recurred in the following 5 years. Several neurological disorders are known to occur or worsen during pregnancy. As far as we know, this is the second reported case of dystonia occurring during pregnancy, thus confirming that dystonia gravidarum represents a new entity and should be considered in women of reproductive age affected by dystonia, especially when presenting with rapid-onset cervical dystonia. 相似文献