全文获取类型
收费全文 | 12821篇 |
免费 | 1229篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 155篇 |
儿科学 | 409篇 |
妇产科学 | 369篇 |
基础医学 | 1734篇 |
口腔科学 | 145篇 |
临床医学 | 1881篇 |
内科学 | 2299篇 |
皮肤病学 | 238篇 |
神经病学 | 1314篇 |
特种医学 | 273篇 |
外科学 | 1364篇 |
综合类 | 155篇 |
一般理论 | 12篇 |
预防医学 | 1651篇 |
眼科学 | 213篇 |
药学 | 917篇 |
中国医学 | 8篇 |
肿瘤学 | 954篇 |
出版年
2023年 | 55篇 |
2022年 | 83篇 |
2021年 | 211篇 |
2020年 | 149篇 |
2019年 | 229篇 |
2018年 | 269篇 |
2017年 | 211篇 |
2016年 | 204篇 |
2015年 | 259篇 |
2014年 | 351篇 |
2013年 | 621篇 |
2012年 | 771篇 |
2011年 | 756篇 |
2010年 | 453篇 |
2009年 | 420篇 |
2008年 | 651篇 |
2007年 | 793篇 |
2006年 | 713篇 |
2005年 | 671篇 |
2004年 | 616篇 |
2003年 | 619篇 |
2002年 | 551篇 |
2001年 | 247篇 |
2000年 | 268篇 |
1999年 | 282篇 |
1998年 | 172篇 |
1997年 | 155篇 |
1996年 | 131篇 |
1995年 | 113篇 |
1994年 | 101篇 |
1993年 | 97篇 |
1992年 | 206篇 |
1991年 | 205篇 |
1990年 | 198篇 |
1989年 | 206篇 |
1988年 | 193篇 |
1987年 | 169篇 |
1986年 | 165篇 |
1985年 | 149篇 |
1984年 | 118篇 |
1983年 | 110篇 |
1982年 | 97篇 |
1981年 | 96篇 |
1980年 | 91篇 |
1979年 | 82篇 |
1978年 | 65篇 |
1975年 | 49篇 |
1974年 | 57篇 |
1973年 | 57篇 |
1972年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
71.
72.
J. Villacis T. R. Rice L. R. Bucci J. M. El-Dahr L. Wild D. DeMerell D. Soteres S. B. Lehrer 《Clinical and experimental allergy》2006,36(11):1457-1461
BACKGROUND: There is concern that shrimp-allergic individuals may react to glucosamine-containing products as shrimp shells are a major source of glucosamine used for human consumption. OBJECTIVE: The purpose of this study was to determine whether shrimp-allergic individuals can tolerate therapeutic doses of glucosamine. METHODS: Subjects with a history of shrimp allergy were recruited and tested for both shrimp reactivity via a prick skin test and shrimp-specific IgE by an ImmunoCAP assay. Fifteen subjects with positive skin tests to shrimp and an ImmunoCAP class level of two or greater were selected for a double-blind placebo-controlled food challenge (DBPCFC) using glucosamine-chondroitin tablets containing 1,500 mg of synthetically produced (control) or shrimp-derived glucosamine. Immediate reactions, including changes in peak flow and blood pressure, and delayed reactions (up to 24 h post-challenge) via questionnaire were noted and assessed. RESULTS: All subjects tolerated 1,500 mg of both shrimp-derived or synthetic glucosamine without incident of an immediate hypersensitivity response. Peak flows and blood pressures remained constant, and no subject had symptoms of a delayed reaction 24 h later. CONCLUSION: This study demonstrates that glucosamine supplements from specific manufacturers do not contain clinically relevant levels of shrimp allergen and therefore appear to pose no threat to shrimp-allergic individuals. 相似文献
73.
Melanophores were studied in tadpoles of the South African clawed toad, Xenopus laevis , during the first week after hatching (stages 46–49) at 25°C. The tadpoles had melanophores with dispersed melanosomes in the light and punctate melanophores in the dark in LD12:12. The melanophores remained punctate in constant dark and the melanosomes remained dispersed in constant light. Lights-out (in the light-time of LD12:12) caused the melanophores to become punctate, which occurred more quickly than the dispersion of melanosomes, which commenced when the lights were turned on (in the dark-time of LD12:12). Melanophores with dispersed melanosomes in tadpoles (in constant light) became punctate in response to a series of melatonin concentrations (0.2–5 ng/ml) in their bathing water irrespective of the time of day melatonin was administered. An image-analysis technique for assessing melanophore responses was tested. 相似文献
74.
75.
The expression of parvalbumin-like immunoreactivity (PV-LIR) was examined in the mystacial representation within the primary somatosensory cortex (SI) of postnatal day 21 and adult rabbits. PV-LIR was expressed in a prominent vibrissa-like array of patches in layer IV despite the fact that barrels were indistinct in the cytoarchitecture. Each patch consisted of dense terminal-like PV-LIR and a preferential concentration of intensely labeled stellate neurons. Layer V contained scattered small and large intensely labeled basket cells. Layer Vb had a distinct layer of lightly labeled large pyramidal cells that received labeled basket cell terminations. Upper layer VI also contained patches of terminal-like PV-LIR that were in register with the overlying vibrissae pattern. These patches also contained a preferential distribution of labeled non-pyramidal cells as well as modified pyramidal cells. These results suggest that PV-LIR in rabbits delineates cortical modules composed of thalamorcotical afferents and inhibitory local circuits in the absence of a distinct barrel cytoarchitecure. In contrast, prior studies of rat SI cortex have revealed a distinct barrel cytoarchitecture but a uniform distribution of PV-LIR. The differences in PV-LIR between rodents and lagomorphs within the vibrissae representation in SI may be related to species differences in thalamic and local cortical circuits devoted to the whisker sense. 相似文献
76.
D Evison R F R Brown P Rice 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(10):1087-1093
The chemical warfare agent, sulphur mustard (SM), is a potent blistering agent in man. Skin exposure can produce partial-thickness burns which take up to three months to heal. The aim of this study was to investigate the use of early laser ablation as a means of accelerating this exceptionally slow rate of healing. Four circular partial-thickness SM burns were induced on the dorsum of nine large white pigs (under general anaesthesia). At 72 h post-exposure, three burns per animal were ablated with a single pass of an UltraPulse 5000C CO(2) laser, at a fluence of 5-6 J cm(-2). All the burns were dressed with silver sulphadiazine and a semi-occlusive dressing. At one, two and three weeks post-surgery three animals were culled and all lesions excised for histological analysis. Burn depth was confirmed and measurements of the radii of regenerative epithelium were performed allowing the area of the zone of re-epithelialisation in each lesion to be calculated. Laser-treated lesions showed a significant increase (350%) in healing rates compared to controls (p<0.005). At two weeks, the laser-treated sites were 95% healed in comparison with control sites (28% healed). These data suggest that laser ablation may be effective in the treatment of partial-thickness SM-induced skin injury. 相似文献
77.
78.
Kazumasa Fujitani Jaffer A. Ajani Christopher H. Crane Barry W. Feig Peter W. Pisters Nora Janjan Garrett L. Walsh Stephen G. Swisher Ara A. Vaporciyan David Rice Angela Welch Jackie Baker Josephine Faust Paul F. Mansfield MD 《Annals of surgical oncology》2007,14(4):1305-1311
Background Significant tumor downstaging has been achieved in patients with localized gastric or gastroesophageal adenocarcinoma by induction
chemotherapy and preoperative chemoradiotherapy (CTX–CTXRT). However, the influence of CTX–CTXRT on operative morbidity and
mortality has not yet been clarified. The aim of the present study was to document the frequency and nature of morbidity and
mortality after surgery combined with CTX–CTXRT, and identify factors predictive of postoperative complications in patients
with localized gastric or gastroesophageal adenocarcinoma.
Methods A prospectively collected database on 71 consecutive patients who underwent CTX–CTXRT at M.D. Anderson Cancer Center between
January 1997 and August 2004 was reviewed. Postoperative morbidity and mortality were investigated, and risk factors for overall
complications were identified by multivariate logistic regression analysis.
Results Overall morbidity and mortality rates were 38.0% (27 patients) and 2.8% (2 patients), respectively. Age greater than 60 years
[relative risk 11.3 (95% confidence interval 2.50–50.6)] and body mass index (BMI) of 26 kg/m2 or above [relative risk 4.08 (95% confidence interval 1.08–15.4)] were significant risk factors for overall complications.
Conclusions CTX–CTXRT can be performed safely with an acceptable operative morbidity and a low operative mortality rate in patients with
gastric or gastroesophageal cancer, with careful consideration of added risk associated with age and obesity. 相似文献
79.
80.