全文获取类型
收费全文 | 229966篇 |
免费 | 16201篇 |
国内免费 | 5653篇 |
专业分类
耳鼻咽喉 | 2108篇 |
儿科学 | 3062篇 |
妇产科学 | 3192篇 |
基础医学 | 25560篇 |
口腔科学 | 5534篇 |
临床医学 | 18704篇 |
内科学 | 31418篇 |
皮肤病学 | 2370篇 |
神经病学 | 15273篇 |
特种医学 | 18178篇 |
外国民族医学 | 27篇 |
外科学 | 19009篇 |
综合类 | 30628篇 |
现状与发展 | 24篇 |
一般理论 | 8篇 |
预防医学 | 15743篇 |
眼科学 | 6009篇 |
药学 | 26675篇 |
66篇 | |
中国医学 | 12736篇 |
肿瘤学 | 15496篇 |
出版年
2024年 | 462篇 |
2023年 | 3284篇 |
2022年 | 6479篇 |
2021年 | 10050篇 |
2020年 | 8092篇 |
2019年 | 7908篇 |
2018年 | 7836篇 |
2017年 | 8427篇 |
2016年 | 8400篇 |
2015年 | 8050篇 |
2014年 | 10442篇 |
2013年 | 13743篇 |
2012年 | 11535篇 |
2011年 | 13635篇 |
2010年 | 9167篇 |
2009年 | 9360篇 |
2008年 | 10797篇 |
2007年 | 11985篇 |
2006年 | 11219篇 |
2005年 | 10149篇 |
2004年 | 8693篇 |
2003年 | 7646篇 |
2002年 | 6110篇 |
2001年 | 5507篇 |
2000年 | 4566篇 |
1999年 | 3888篇 |
1998年 | 3122篇 |
1997年 | 3242篇 |
1996年 | 2965篇 |
1995年 | 2593篇 |
1994年 | 2451篇 |
1993年 | 2046篇 |
1992年 | 1841篇 |
1991年 | 1707篇 |
1990年 | 1506篇 |
1989年 | 1252篇 |
1988年 | 1181篇 |
1987年 | 1110篇 |
1986年 | 997篇 |
1985年 | 1438篇 |
1984年 | 1171篇 |
1983年 | 847篇 |
1982年 | 941篇 |
1981年 | 776篇 |
1980年 | 721篇 |
1979年 | 570篇 |
1978年 | 372篇 |
1977年 | 322篇 |
1976年 | 281篇 |
1975年 | 198篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
目的探讨经皮冠状动脉介入(PCI)和静脉溶栓在急性心肌梗死患者中的应用价值。方法选择我院2013年1月至2014年9月收治的60例急性心肌梗死患者作为研究对象,随机分为实验组和对照组各30例。实验组患者采用PCI治疗,对照组患者采用静脉溶栓治疗,比较两组患者血管再通率、死亡发生率、ST段回落情况、住院时间、近远期不良事件发生率、左室舒张末径和左室射血分数变化情况。结果实验组血管再通率显著高于对照组,差异有统计学意义(P<0.05),而近期和远期不良事件发生率均低于对照组,近期不良事件发生率组间比较差异有统计学意义(P<0.05),而远期不良事件发生率比较差异无统计学意义(P>0.05)。实验组患者死亡发生率、ST段回落和住院时间均低于对照组,差异均有统计学意义(P<0.05)。实验组左室射血分数在术后1个月、3个月和6个月时均显著高于对照组,差异均有统计学意义(P<0.05)。结论急性心肌梗死患者应用PCI治疗可显著提高血管再通率、降低死亡和不良事件发生率,有效改善心功能。 相似文献
152.
《Journal of the American Medical Directors Association》2020,21(12):1968-1972.e2
ObjectivesVitamin D deficiency is prevalent among older adults. We aimed to study whether residential greenness could alter serum 25(OH)D concentrations as a possible mechanism of residential greenness's positive health effects.DesignA longitudinal cohort study.Setting and ParticipantsWe included older adults aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) with follow-up between 2012 and 2014.MethodsWe measured residential greenness by calculating annual average Normalized Difference Vegetation Index (NDVI) in a 500 m radius by using satellite images around each participant's residential address. Serum 25-hydroxyvitamin D (25(OH)D) concentration was dichotomized into 2 categories: nondeficiency (≥50 nmol/L) and deficiency (<50 nmol/L). We used the generalized estimating equation to examine the relationship between annual average NDVI and serum 25(OH)D.ResultsWe included 1336 participants in our analysis. The annual average NDVI was 0.49, and mean serum 25(OH)D was 43 nmol/L at baseline. Each 0.1-unit increase in annual average NDVI was associated with a 13% higher odds of vitamin D nondeficiency [95% confidence interval (CI): 1.01, 1.26]. The association was stronger among men [odds ratio (OR): 1.17, 95% CI: 1.02, 1.35] than women (OR: 1.08, 95% CI: 0.91, 1.29) and also stronger among those who were free of activities of daily living (ADL) disability at baseline (OR: 1.12, 95% CI: 1.00, 1.25). During the follow-up period, the participants who lived in greener areas were more likely to have an improved, rather than stable or deteriorated, vitamin D status (OR: 1.94, 95% CI: 1.51, 2.51).Conclusions and ImplicationsOur study suggests that higher levels of residential greenness are associated with higher serum 25(OH)D concentrations, which has implications for prevention of vitamin D deficiency among older adults. 相似文献
153.
154.
155.
156.
157.
《Clinical Lymphoma, Myeloma & Leukemia》2020,20(8):e461-e467
IntroductionVon Willebrand factor (vWF) cleaving protease ADAMTS-13 has a key role for maintaining normal size of vWF. A deficiency or dysfunction of vWF cleaving protease is associated with ultra large vWF multimers and thrombotic microangiopathy. Patients with cancers have reduced levels of vWF cleaving protease. In this pilot study, we have evaluated whether or not deficiencies of ADAMTS-13 were present in myelodysplastic syndromes (MDS). Moreover, we assessed if a reduction in basal levels of ADAMTS-13 may play a role in the prognosis of MDS.Patients and MethodsWe measured and compared the levels of vWF cleaving protease ADAMTS-13 in 100 patients with MDS and 35 healthy controls. Patients were divided into 2 groups according to the International Prognostic Scoring System: group I consisting of 44 patients with low-risk MDS and group II of 56 patients with high-risk MDS. Patients with high-risk and low-risk MDS presented significantly lower levels of ADAMTS-13 than controls (P < .001 and P = .0177, respectively). High-risk patients had significantly lower levels of ADAMTS-13 when compared with the low-risk group (P < .001).ResultsWe found that reduced levels of ADAMTS-13 have a relationship with overall survival (P < .001). Statistical analysis showed that ADAMTS-13 correlates with cytogenetics (P < .001) and a tendency of slight correlation with platelet count and basal levels of ADAMTS-13 (R, 0.35; P value, 0.001). Moreover, we found that levels of ADAMTS-13 have correlation with response to treatment (P < .001).ConclusionsADAMTS-13 in MDS might represent a surrogate marker of prognosis, response to therapy, or disease progression. Further studies are needed. 相似文献
158.
《Cancer cell》2020,37(1):123-134.e5
- Download : Download high-res image (200KB)
- Download : Download full-size image
159.
《Clinical oncology (Royal College of Radiologists (Great Britain))》2020,32(6):347-353
The current COVID-19 pandemic presents a substantial obstacle to cancer patient care. Data from China as well as risk models suppose that cancer patients, particularly those on active, immunosuppressive therapies are at higher risks of severe infection from the illness. In addition, staff illness and restructuring of services to deal with the crisis will inevitably place treatment capacities under significant strain. These guidelines aim to expand on those provided by NHS England regarding cancer care during the coronavirus pandemic by examining the known literature and provide guidance in managing patients with urothelial and rarer urinary tract cancers. In particular, they address the estimated risk and benefits of standard treatments and consider the alternatives in the current situation. As a result, it is recommended that this guidance will help form a framework for shared decision making with patients. Moreover, they do not advise a one-size-fits-all approach but recommend continual assessment of the situation with discussion within and between centres. 相似文献
160.
目的 探讨非高密度脂蛋白胆固醇水平(non-HDL-C)与冠心病(CHD)患者冠状动脉病变Gensini评分的关系及临床意义。方法 对225例疑诊或既往临床诊断CHD患者予以冠状动脉造影(CAG),将造影阴性的39例作为对照组(HC组),造影阳性的186例患者诊断为CHD,结合临床特点分为心绞痛组(AP组)122例和心肌梗死组(AMI组)64例。采用Gensini评分对冠状动脉病变程度评分,测定患者全套血脂水平,探讨non-HDL-C及相关脂质成分与冠状动脉病变程度Gensini评分的相关性;同时对他汀类药物强化降脂达标,低密度脂蛋白胆固醇(LDL-C)<1.80 mmol/L的AP组患者进行non-HDL-C与冠状动脉病变程度Gensini评分的亚组分析。结果 AMI组non-HDL-C水平高于AP组及HC组,AP组non-HDL-C水平高于HC组,差异均有统计学意义(P<0.05);CHD患者non-HDL-C水平与Gensini评分呈正相关(r=0.562,P<0.05);LDL-C控制达标的AP组患者,高non-HDL-C组(≥2.60 mmol/L)比低non-HDL-C组(<2.60 mmol/L)Gensini评分明显升高,差异均有统计学意义(P<0.05)。结论 non-HDL-C与冠状动脉病变程度密切相关,non-HDL-C在评估LDL-C控制达标患者的冠状动脉病变程度及再发心血管事件风险上有一定价值,可作为LDL-C达标后心血管残余风险新的观察指标。 相似文献