全文获取类型
收费全文 | 17835篇 |
免费 | 1321篇 |
国内免费 | 454篇 |
专业分类
耳鼻咽喉 | 101篇 |
儿科学 | 571篇 |
妇产科学 | 160篇 |
基础医学 | 1247篇 |
口腔科学 | 300篇 |
临床医学 | 1373篇 |
内科学 | 1699篇 |
皮肤病学 | 267篇 |
神经病学 | 1311篇 |
特种医学 | 581篇 |
外国民族医学 | 5篇 |
外科学 | 993篇 |
综合类 | 2149篇 |
现状与发展 | 3篇 |
一般理论 | 2篇 |
预防医学 | 2100篇 |
眼科学 | 311篇 |
药学 | 3867篇 |
20篇 | |
中国医学 | 1295篇 |
肿瘤学 | 1255篇 |
出版年
2024年 | 43篇 |
2023年 | 241篇 |
2022年 | 400篇 |
2021年 | 511篇 |
2020年 | 587篇 |
2019年 | 527篇 |
2018年 | 506篇 |
2017年 | 609篇 |
2016年 | 651篇 |
2015年 | 584篇 |
2014年 | 1118篇 |
2013年 | 1517篇 |
2012年 | 937篇 |
2011年 | 947篇 |
2010年 | 713篇 |
2009年 | 764篇 |
2008年 | 786篇 |
2007年 | 790篇 |
2006年 | 699篇 |
2005年 | 635篇 |
2004年 | 542篇 |
2003年 | 532篇 |
2002年 | 403篇 |
2001年 | 330篇 |
2000年 | 287篇 |
1999年 | 239篇 |
1998年 | 253篇 |
1997年 | 253篇 |
1996年 | 218篇 |
1995年 | 193篇 |
1994年 | 191篇 |
1993年 | 178篇 |
1992年 | 197篇 |
1991年 | 190篇 |
1990年 | 172篇 |
1989年 | 164篇 |
1988年 | 169篇 |
1987年 | 167篇 |
1986年 | 152篇 |
1985年 | 170篇 |
1984年 | 181篇 |
1983年 | 100篇 |
1982年 | 145篇 |
1981年 | 97篇 |
1980年 | 101篇 |
1979年 | 93篇 |
1978年 | 67篇 |
1977年 | 69篇 |
1976年 | 58篇 |
1975年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The aim of this study was to develop films based on β–glucans in association with pomegranate juice for its potential in metabolic disorders such as diabetes due to plenty of bioactive compounds from the film composition. Initially, a Box-Behnken design was generated by varying the level of β–glucan content (0.5, 1, 1.5 g), sodium alginate (0.2, 0.4, 0.6 g) and pomegranate juice (10, 20, 30 mL) for development of films. Subsequently, glycerin was added as 25% of the total dry matter. The optimization of the films prepared by the solvent casting method was conducted based on the different responses such as: water vapor transmission rate (WVTR), water vapor permeability (WVP), thickness, density, moisture content, solubility, film opacity and color. The water activity profile and FT–IR analysis were performed in all tests. The model was used to determine the optimal experimental values considering that the optimal film will make a sustained contribution to diabetes. The optimal values of the film sample made of β–glucans, sodium alginate, pomegranate juice and glycerin make it befitting for packaging dry powdered pharmaceuticals. Finally, antimicrobial activity against Gram-negative and Gram-positive bacteria, UV barrier properties and microcrack and pore detections through SEM were also investigated for the optimal film sample. 相似文献
102.
The unregulated use of acetaminophen (APAP), an antipyretic and analgesic drug, harms hepatocytes and kidney cells, leading to liver failure and acute kidney injury. Herein, we investigate whether APAP damages macrophages in the immune system by observing its effects on macrophage proliferation and apoptosis. Using proteomics, we analyzed the effects of APAP on macrophage protein expression profiles and evaluated whether polydatin, the active ingredient in grapes and wine, can repair the damaged cells. The results showed that APAP alters the morphology and physiological processes of macrophages, inhibits macrophage proliferation, and promotes apoptosis. We observed 528 differentially expressed proteins when 500 µg/mL APAP was administered to the cells. These proteins are involved in biological processes including cell division, apoptosis, and acute phase response. Overall, our findings demonstrate that APAP harms the immune system by damaging macrophages and that polydatin can repair this damage. 相似文献
103.
目的观察强心化瘀方对慢性心力衰竭的临床疗效。方法将106例慢性心力衰竭患者随机分为治疗组(A组,应用强心化瘀方治疗,69例)和对照组(B组,应用西医综合治疗,37例),比较两组总有效率、心功能改善状况、心力衰竭常见症状及体征改善率。结果 A组总有效率高于B组(94.20% v s .72.98%)( P<0.05)。治疗后,A组气短、心悸、疲劳乏力、咳嗽咳痰和紫绀的改善率均高于B组(91.30% vs .72.97%、81.03% vs .48.28%、65.57% vs .15.63%、77.14% vs .33.33%和75.56% v s .24.13%)( P<0.05)。治疗后,A组心功能Ⅰ级患者所占比例多于B组( P<0.05)。结论强心化瘀方治疗慢性心力衰竭疗效确切,较常规西药疗效好。 相似文献
104.
Nina Streefkerk Marianne J. Heins Jop C. Teepen Elizabeth A. M. Feijen Dorine Bresters Eline van Dulmen‐den Broeder Margriet van der Heiden‐van der Loo Marry M. van den Heuvel‐Eibrink Flora E. van Leeuwen Jacqueline J. Loonen Helena J. H. van der Pal Ccile M. Ronckers A. Birgitta Versluys Wim J. E. Tissing Joke C. Korevaar Leontien C. M. Kremer 《Pediatric blood & cancer》2019,66(8)
105.
槲皮素对培养人视网膜色素上皮细胞增生及DNA合成的影响 总被引:3,自引:0,他引:3
目的研究槲皮素(quercetin, QUE)对培养人视网膜色素上皮(retinal pigment epithelium, RPE)细胞增生和DNA合成以及对表皮生长因子(epidermal growth factor, EGF)促RPE细胞增生和DNA合成作用的影响。方法用细胞计数和3H-胸腺嘧啶核苷(3H-thymidine, 3H-TdR)掺入方法,观察不同浓度(200、100、50、1μmol/L)的QUE和最大浓度的QUE(200μmol/L)在不同作用时间(24-168小时),分别单独或与EGF共同作用时,对RPE细胞增生及DNA合成的影响,排除着色的死细胞,用活细胞计数法判断药物的细胞毒性作用。结果QUE 200μmol/L具有最强的抑制效应,48小时时抑制效应已明显出现,96小时时抑制达到高峰。与QUE单独作用相比,QUE对EGF的促RPE细胞增生效应能产生更强的抑制。QUE无细胞毒性作用,各实验组细胞活力均在85.00%以上。结论QUE以剂量依赖和时间依赖的方式抑制RPE细胞的增生,尤其是由EGF刺激的增生,并且对培养的RPE细胞无细胞毒作用。(中华眼底病杂志,1999,15:27-29) 相似文献
106.
107.
108.
Daisuke Tamanoi Koichi Saruwatari Kosuke Imamura Ryo Sato Takuya Jodai Shohei Hamada Yusuke Tomita Sho Saeki Shikiko Ueno Yuji Yonemura Hidenori Ichiyasu Takuro Sakagami 《Internal medicine (Tokyo, Japan)》2022,61(11):1731
The effect of radiotherapy during immunotherapy on immune-related adverse events (irAEs) is not fully understood. We herein report a 74-year-old woman diagnosed with lung adenocarcinoma with programmed death ligand 1 expression ≥50% and treated with pembrolizumab. She developed fatal immune thrombocytopenia associated with pembrolizumab immediately following radiotherapy. A flow cytometry analysis of peripheral blood detected an increased expression of programmed death-1 (PD-1) and Ki-67 in CD4+ and CD8+ T cells after radiotherapy, compared with pre-irradiation measurements. This case suggests that radiotherapy may evoke irAEs during treatment with anti-PD-1 antibodies, which physicians should consider when using radiotherapy in patients treated with these drugs. 相似文献
109.
The Coronavirus Disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome-coronavirus-2, has claimed 5,587,549 lives worldwide as of January 20, 2022. Fortunately, large-scale vaccination can mitigate the impact of COVID-19 by making the disease milder and less common. Although 75.2% of the United States population has received at least 1 dose of a COVID-19 vaccines thus far, concerns regarding vaccine side effects have contributed to vaccine hesitancy. Furthermore, nearly 50% of adults in the United States are concerned not only about side effects, but about their downstream impact, including missed work.The goal of this cross-sectional study was to investigate the effect of messenger RNA vaccine adverse effects on the propensity to miss work among employees associated with a single, large academic health center.Using Qualtrics, all employees, including faculty, staff, and trainees, of 5 large departments were surveyed to determine whether they received the COVID-19 vaccine and which type, and any symptoms they experienced after receipt of either vaccine dose. We hypothesized that vaccine recipients would be more likely to miss work or feel sick enough to miss work following the second dose.Thirty-seven percent of respondents experienced events severe enough that they needed to miss work from either of the doses, with the majority (27.8%) related to the second dose. These findings are consistent with and expand on the results from the phase 3 trials for Pfizer-BionTech and Moderna, which showed that vaccine side effects were more common after the second dose than after the first dose. Our statistically significant finding was more common among Asians, women, trainees/house staff, and nonphysician clinical employees.With an increasing number of individuals taking the vaccine, employers will need to account for the impact of adverse effects on their employees’ ability to work. These findings will further help organizations better plan for staffing as vaccinations increase to mitigate the spread of COVID-19. 相似文献
110.
Research on the effects of glyphosate and seed germination spans 30 years. Despite several studies reporting detrimental effects of the herbicide on seedling germination and growth, glyphosate is still being registered for use as a weed killer and preharvest desiccant. Its nonselective nature and low chance of species developing resistance has lead to the development of genetically modified crops tolerant to the herbicide which also raises concerns about increased reliance on herbicide use, and subtle ecological impact.This paper presents the result of a literature review on past studies mostly, on crop species, and the results of a new experiment performed with emphasis on noncrop species. The new experimental part attempted to determine whether glyphosate (Roundup®) would have an effect on the germination and growth of the F1 generation of seeds produced by plants sprayed with the herbicide. It was designed to mirror spray drift which might affect noncrop plants in nontarget drift zones. Of the 11 species tested using treatments of 0% (control), 1%, 10% or 100% of a 890 g a.i./ha label rate solution sprayed near seed maturity, seven showed a significant effect of the glyphosate treatment on germination and/or growth characteristics.Results of this experiment together with several previous studies reviewed in this paper suggest that there are significant effects to keep in mind when using herbicides such as glyphosate as severe ecological changes could occur. 相似文献