全文获取类型
收费全文 | 379581篇 |
免费 | 24131篇 |
国内免费 | 2808篇 |
专业分类
耳鼻咽喉 | 5187篇 |
儿科学 | 8211篇 |
妇产科学 | 10086篇 |
基础医学 | 53161篇 |
口腔科学 | 11776篇 |
临床医学 | 30118篇 |
内科学 | 78430篇 |
皮肤病学 | 8547篇 |
神经病学 | 27197篇 |
特种医学 | 13924篇 |
外国民族医学 | 82篇 |
外科学 | 60739篇 |
综合类 | 9958篇 |
现状与发展 | 1篇 |
一般理论 | 64篇 |
预防医学 | 17448篇 |
眼科学 | 9437篇 |
药学 | 30983篇 |
1篇 | |
中国医学 | 2192篇 |
肿瘤学 | 28978篇 |
出版年
2021年 | 2628篇 |
2019年 | 2732篇 |
2018年 | 4531篇 |
2017年 | 3449篇 |
2016年 | 3534篇 |
2015年 | 4047篇 |
2014年 | 5710篇 |
2013年 | 7400篇 |
2012年 | 10043篇 |
2011年 | 10227篇 |
2010年 | 6204篇 |
2009年 | 5857篇 |
2008年 | 9468篇 |
2007年 | 10290篇 |
2006年 | 10211篇 |
2005年 | 9281篇 |
2004年 | 8792篇 |
2003年 | 8527篇 |
2002年 | 8197篇 |
2001年 | 28244篇 |
2000年 | 28777篇 |
1999年 | 23658篇 |
1998年 | 5169篇 |
1997年 | 4252篇 |
1996年 | 3834篇 |
1995年 | 3485篇 |
1994年 | 3107篇 |
1993年 | 2849篇 |
1992年 | 16083篇 |
1991年 | 14827篇 |
1990年 | 14168篇 |
1989年 | 13973篇 |
1988年 | 12586篇 |
1987年 | 12067篇 |
1986年 | 11110篇 |
1985年 | 10323篇 |
1984年 | 6916篇 |
1983年 | 5601篇 |
1982年 | 2721篇 |
1979年 | 5484篇 |
1978年 | 3349篇 |
1977年 | 2976篇 |
1975年 | 2649篇 |
1974年 | 3066篇 |
1973年 | 2868篇 |
1972年 | 2831篇 |
1971年 | 2775篇 |
1970年 | 2513篇 |
1969年 | 2545篇 |
1968年 | 2250篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
2.
卫逸涛肖惠敏谢银环孙丽军 《中华健康管理学杂志》2022,(8):547-552
目的了解老年人生命晚期获知疾病相关信息意向及影响因素。方法2016年10月至2017年6月,采用生命晚期疾病信息意向问卷,利用方便抽样法对福州市中心城区7所养老机构及15个社区的414例年龄≥60岁的老年人进行横断面调查,采用单因素分析、多元线性回归与有序多分类logistic回归分析老年人对疾病相关信息的需求水平、获知程度意向及其影响因素。结果414例老年人疾病相关信息需求得分为(17.1±4.9)分;48.8%(202/414)希望详尽知晓,30.7%(127/414)希望选择性了解,20.5%(85/414)不想知道任何信息;多元线性回归分析显示,年龄、文化程度、是否接受/见过其他生命维持治疗(LSTs)是影响老年人疾病相关信息需求水平的主要因素(标准化回归系数分别为-0.141、0.116、0.115,均P<0.05);有序多分类logistic分析显示,年龄(以60~69岁为参照,70~79岁:OR=0.544,95%CI:0.310~0.957;80~89岁:OR=0.526,95%CI:0.289~0.956)、文化程度(以小学及以下为参照,大专及以上:OR=2.166,95%CI:1.093~4.290)、主要生活费来源(以其他补贴为参照,家人支持:OR=7.303,95%CI:1.157~46.108;退休金:OR=9.288,95%CI:1.502~57.415;公积金/储蓄:OR=15.676,95%CI:2.122~115.793)、是否接受/见过其他LSTs(以是为参照,OR=1.985,95%CI:1.150~3.425)是影响老年人疾病相关信息获知程度意向的主要因素。结论老年人生命晚期获知疾病相关信息的意向程度较高,年龄、文化程度、主要生活费来源、是否接受/见过其他生命维持治疗等是其主要影响因素。 相似文献
3.
4.
5.
6.
Nevo N. Goldstein A. L. Staierman M. Eran N. Carmeli I. Rayman S. mnouskin Y. 《Hernia》2022,26(6):1491-1499
Hernia - The minimally invasive surgical repair of combined inguinal and ventral hernias often requires shifting from one approach or plane to another. The traditional enhanced-view totally... 相似文献
7.
8.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs. 相似文献
9.
Edward J. Holland Walter O. Whitley Kenneth Sall Stephen S. Lane Aparna Raychaudhuri Steven Y. Zhang 《Current medical research and opinion》2016,32(10):1759-1765
Objective: Report efficacy findings from three clinical trials (one phase 2 and two phase 3 [OPUS-1, OPUS-2]) of lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease (DED).Research design and methods: Three 84-day, randomized, double-masked, placebo-controlled trials. Adults (≥18 years) with DED were randomized (1:1) to lifitegrast 5.0% or matching placebo. Changes from baseline to day 84 in signs and symptoms of DED were analyzed.Main outcome measures: Phase 2, pre-specified endpoint: inferior corneal staining score (ICSS; 0–4); OPUS-1, coprimary endpoints: ICSS and visual-related function subscale (0–4 scale); OPUS-2, coprimary endpoints: ICSS and eye dryness score (EDS, VAS; 0–100).Results: Fifty-eight participants were randomized to lifitegrast 5.0% and 58 to placebo in the phase 2 trial; 293 to lifitegrast and 295 to placebo in OPUS-1; 358 to lifitegrast and 360 to placebo in OPUS-2. In participants with mild-to-moderate baseline DED symptomatology, lifitegrast improved ICSS versus placebo in the phase 2 study (treatment effect, 0.35; 95% CI, 0.05–0.65; p?=?0.0209) and OPUS-1 (effect, 0.24; 95% CI, 0.10–0.38; p?=?0.0007). Among more symptomatic participants (baseline EDS ≥40, recent artificial tear use), lifitegrast improved EDS versus placebo in a post hoc analysis of OPUS-1 (effect, 13.34; 95% CI, 2.35–24.33; nominal p?=?0.0178) and in OPUS-2 (effect, 12.61; 95% CI, 8.51–16.70; p?<?0.0001).Limitations: Trials were conducted over 12 weeks; efficacy beyond this period was not assessed.Conclusions: Across three trials, lifitegrast improved ICSS in participants with mild-to-moderate baseline symptomatology in two studies, and EDS in participants with moderate-to-severe baseline symptomatology in two studies. Based on the overall findings from these trials, lifitegrast shows promise as a new treatment option for signs and symptoms of DED. 相似文献
10.