全文获取类型
收费全文 | 853篇 |
免费 | 22篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 33篇 |
妇产科学 | 7篇 |
基础医学 | 61篇 |
口腔科学 | 10篇 |
临床医学 | 59篇 |
内科学 | 104篇 |
皮肤病学 | 29篇 |
神经病学 | 3篇 |
特种医学 | 98篇 |
外科学 | 108篇 |
综合类 | 260篇 |
预防医学 | 28篇 |
眼科学 | 4篇 |
药学 | 34篇 |
肿瘤学 | 46篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 28篇 |
2014年 | 13篇 |
2013年 | 18篇 |
2012年 | 18篇 |
2011年 | 12篇 |
2010年 | 46篇 |
2009年 | 45篇 |
2008年 | 34篇 |
2007年 | 43篇 |
2006年 | 59篇 |
2005年 | 39篇 |
2004年 | 56篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 17篇 |
2000年 | 19篇 |
1999年 | 27篇 |
1998年 | 40篇 |
1997年 | 49篇 |
1996年 | 52篇 |
1995年 | 32篇 |
1994年 | 29篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1940年 | 1篇 |
排序方式: 共有885条查询结果,搜索用时 0 毫秒
101.
Fetal erythropoiesis in steel mutant mice. III. Defect in differentiation from BFU-E to CFU-E during early development 总被引:5,自引:1,他引:5
Erythroid progenitor cells in +/+ and Sl/Sld fetal livers manifested as burst-forming units-erythroid (BFU-E) and colony-forming units- erythroid (CFU-E) were assayed in vitro during early development. The proportion of BFU-E was higher as mutant than in normal fetal livers. On the other hand, the proportion of CFU-E was less in the mutant than in the normal. These results suggest that the defect in Sl/Sld fetal hepatic erythropoiesis is expressed at the steps of differentiation that effect the transition from BFU-E to CFU-E. 相似文献
102.
NICHOLAS J TALLEY SK LAM KL GOH KM FOCK 《Journal of gastroenterology and hepatology》1998,13(4):335-353
Dyspepsia is most optimally defined as pain or discomfort centred in the upper abdomen. The symptom complex may be caused by peptic ulcer disease, gastro-oesophageal reflux, or gastric cancer but is most often due to functional (or non-ulcer) dyspepsia. While upper endoscopy is the method of choice to determine the underlying cause of dyspepsia, it is expensive. A more pragmatic approach is needed in the Asia-Pacific region where health services are limited. A detailed treatment algorithm is given for managing patients presenting with new-onset dyspepsia and documented functional dyspepsia after endoscopy, and evidence to support this approach is reviewed. Prompt endoscopy is recommended for patients with alarm features. In patients without alarm features, treatment for 2–4 weeks with an empirical anti-secretory or prokinetic agent, followed by investigation using non-invasive Helicobacter pylori testing and treatment for patients who do not respond or relapse, is recommended. Trials of management strategies are now needed to establish the efficacy and cost-effectiveness of the approaches recommended. 相似文献
103.
104.
P Dutta U Mitra DR Saha SK Niyogi B Manna SK Bhattacharya 《Acta paediatrica (Oslo, Norway : 1992)》1999,88(8):822-826
A hospital-based case-control study was carried out to clarify the characteristics of mucoid presentation of acute enterocolitis in children. One hundred sixty-eight cases of acute mucoid enterocolitis (study population) were compared with 200 cases of watery diarrhoea and 118 cases of blood dysentery (control groups) on the basis of clinical characteristics and findings on stool examination. Study and control groups were comparable with respect to age, body weight and nutritional status. There was no significant difference in clinical characteristics (duration of diarrhoea, stool frequency, presence of vomiting, fever and dehydration) between patients suffering from mucoid enterocolitis and blood dysentery. However, watery diarrhoea patients had significantly high frequencies of vomiting (p = 0.00001) and dehydration (p 相似文献
105.
Emily YY Chan William B Goggins Janice SK Yue Poyi Lee 《Bulletin of the World Health Organization》2013,91(8):576-584
Objective
To explore the relationship between weather phenomena and pollution levels and daily hospital admissions (as an approximation to morbidity patterns) in Hong Kong Special Administrative Region (SAR), China, in 1998–2009.Methods
Generalized additive models and lag models were constructed with data from official sources on hospital admissions and on mean daily temperature, mean daily wind speed, mean relative humidity, daily total global solar radiation, total daily rainfall and daily pollution levels.Findings
During the hot season, admissions increased by 4.5% for every increase of 1 °C above 29 °C; during the cold season, admissions increased by 1.4% for every decrease of 1 °C within the 8.2–26.9 °C range. In subgroup analyses, admissions for respiratory and infectious diseases increased during extreme heat and cold, but cardiovascular disease admissions increased only during cold temperatures. For every increase of 1 °C above 29 °C, admissions for unintentional injuries increased by 1.9%. During the cold season, for every decrease of 1 °C within the 8.2–26.9 °C range, admissions for cardiovascular diseases and intentional injuries rose by 2.1% and 2.4%, respectively. Admission patterns were not sensitive to sex. Admissions for respiratory diseases rose during hot and cold temperatures among children but only during cold temperatures among the elderly. In people aged 75 years or older, admissions for infectious diseases rose during both temperature extremes.Conclusion
In Hong Kong SAR, hospitalizations rise during extreme temperatures. Public health interventions should be developed to protect children, the elderly and other vulnerable groups from excessive heat and cold. 相似文献106.
目的 建立早产儿三元整合式教育方案,并探讨其培训效果。方法 组建三元整合教育团队,按照早产儿的发育发展特点构建教育课程,搭建教育平台,包括开办家长学校、开展家长微课堂、视频引导、家长床旁照护操作培训等。采用NICU家长满意度调查表调查并比较培训前后家长满意度。结果 培训后早产儿家长的满意度总分为(191.90±0.20)分,培训前满意度总分为(176.00±4.40)分,差异有统计学意义(t=-41.68,P<0.001);培训前后家长的知识和信息维度、家长参与照护维度、医护人员专业态度维度得分的比较,差异有统计学意义(t1=-20.83,P1<0.001;t2=-27.30,P2<0.001;t3=-27.10,P3<0.001)。结论 早产儿三元整合式教育方案能提升家长的照护知识和参与照护能力,提高家长对医护人员专业态度的满意度。 相似文献
107.
亚太地区炎症性肠病处理共识意见(一) 总被引:24,自引:0,他引:24
虽然目前亚太地区尚无炎症性肠病(IBD)的大规模流行病学资料,但一系列研究显示其发病率和患病率呈上升趋势。与西方国家相比仍呈滞后现象。溃疡性结肠炎(UC)的发病率仍较克罗恩病(CD)高。除地域差异外。在一些多民族国家中,IBD尚可见种族差异。亚太地区IBD的遗传背景有异于西方国家。如据报道该地区CD患者未检出NOD2/CARDI5变异。一般而言,该地区IBD患者的临床过程似不如西方国家严重。
亚太地区IBD的诊断存在一些特殊问题。如缺乏IBD诊断金标准。存在多种小肠结肠炎,与IBD临床表现相似,使鉴别诊断特别困难。迄今为止,亚太地区IBD的诊断标准多采用西方国家的诊断标准。诊断必须逐步排除非IBD的小肠结肠炎。确诊应有典型的组织学表现。某些患者需借助随访和诊断性治疗才能确诊。进一步研究IBD发病机制将有助于开发更好的诊断标记物。
亚太地区IBD的治疗亦存在特殊问题。由于诊断困难。IBD患者常未能及时接受适当的药物治疗,但该地区仍广泛采用药物治疗方案。结合西方指南和本地经验可制定类似的处理原则。以利诱导缓解和维持缓解。提倡逐级使用基于病变范围、活动性和严重度的阶梯式治疗方案。对不同病例采用综合性、个体化的方法。随着对IBD发病机制和亚太地区IBD独特性的深入理解。合理、实用的药物治疗指南和应用生物制剂治疗将改善该地区IBD的治疗前景。 相似文献
108.
109.
110.
Biological evaluation of intervertebral disc cells in different formulations of gellan gum‐based hydrogels 下载免费PDF全文
G Khang SK Lee HN Kim J Silva‐Correia ME Gomes CAA Viegas IR Dias JM Oliveira RL Reis 《Journal of tissue engineering and regenerative medicine》2015,9(3):265-275
Gellan gum (GG)‐based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine‐tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG‐MA) and high‐acyl gellan gums (HA‐GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA‐GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA‐GG content induced greater weight loss in the GG‐MA/HA‐GG formulation compared to GG‐MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein‐AM and ATP assays. Results showed that tunable GG‐MA/HA‐GG hydrogels were non‐cytotoxic and supported viability of rabbit NP cells. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献