全文获取类型
收费全文 | 204223篇 |
免费 | 14525篇 |
国内免费 | 4239篇 |
专业分类
耳鼻咽喉 | 2605篇 |
儿科学 | 3668篇 |
妇产科学 | 4316篇 |
基础医学 | 29366篇 |
口腔科学 | 4042篇 |
临床医学 | 20980篇 |
内科学 | 37814篇 |
皮肤病学 | 4782篇 |
神经病学 | 14730篇 |
特种医学 | 9443篇 |
外国民族医学 | 17篇 |
外科学 | 26651篇 |
综合类 | 8887篇 |
现状与发展 | 10篇 |
一般理论 | 85篇 |
预防医学 | 12337篇 |
眼科学 | 5506篇 |
药学 | 17987篇 |
31篇 | |
中国医学 | 3445篇 |
肿瘤学 | 16285篇 |
出版年
2023年 | 1643篇 |
2022年 | 4421篇 |
2021年 | 6966篇 |
2020年 | 4038篇 |
2019年 | 5083篇 |
2018年 | 5970篇 |
2017年 | 4583篇 |
2016年 | 5444篇 |
2015年 | 7517篇 |
2014年 | 9237篇 |
2013年 | 10467篇 |
2012年 | 15781篇 |
2011年 | 15623篇 |
2010年 | 9240篇 |
2009年 | 7701篇 |
2008年 | 11526篇 |
2007年 | 11432篇 |
2006年 | 10547篇 |
2005年 | 10168篇 |
2004年 | 8593篇 |
2003年 | 7625篇 |
2002年 | 6585篇 |
2001年 | 5434篇 |
2000年 | 5120篇 |
1999年 | 4468篇 |
1998年 | 1954篇 |
1997年 | 1699篇 |
1996年 | 1473篇 |
1995年 | 1336篇 |
1994年 | 1160篇 |
1993年 | 936篇 |
1992年 | 1933篇 |
1991年 | 1886篇 |
1990年 | 1619篇 |
1989年 | 1472篇 |
1988年 | 1369篇 |
1987年 | 1215篇 |
1986年 | 1177篇 |
1985年 | 1002篇 |
1984年 | 712篇 |
1983年 | 639篇 |
1982年 | 445篇 |
1981年 | 429篇 |
1980年 | 367篇 |
1979年 | 562篇 |
1978年 | 426篇 |
1977年 | 405篇 |
1976年 | 352篇 |
1974年 | 376篇 |
1973年 | 342篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Qiangsheng He Chongfei Huang Xiwen Qin Yuanyuan Yu Di Tang Junjie Huang Zi Chong Kuo Yuyao Ling Deli Mao Bin Xia Wenjing Li Kuiqing Lu Man Yang Yulong He Wenbo Meng Jinqiu Yuan Yihang Pan 《International journal of cancer. Journal international du cancer》2023,153(5):942-949
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes. 相似文献
12.
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
13.
The research and development of penicillin started with difficulty before 1949 and achieved certain results. In 1951, after the founding of the People's Republic of China, Zhang Weishen, as the only Chinese scientist who had been trained and worked in a penicillin research and development center in the United States for many years, overcame many difficulties and returned to China. In 1953, with the efforts of Zhang Weishen and his colleagues, China realized the industrialized production of penicillin, alleviating the urgent needs of the masses. Antibiotics has also become the first discipline to achieve major scientific and technological achievements after the founding of the New China. In the mid-1950s, the technical breakthrough in the localization of lactose substitutes marked the localization of the raw materials of the penicillin-producing culture medium, which paved the way for the industrialized production of penicillin with Chinese characteristics. Antibiotics have become one of the most widely used and affordable drugs for hundreds of millions of patients in China, and China has since ended the humiliating history of the “Sick Man of East Asia". 相似文献
14.
Clinical and Experimental Medicine - Recently, the use of novel targeted drugs significantly improved the overall response rate (ORR) and survival of patients with relapsed/refractory chronic... 相似文献
15.
16.
17.
目的探讨脑卒中患者急性应激障碍发生现状及影响因素。方法采用斯坦福急性应激反应问卷对349例脑卒中住院患者进行调查。结果共163例(46.70%)患者发生急性应激障碍;Logistic回归分析结果显示,患者性格、是否存在偏瘫及是否吞咽功能障碍是脑卒中患者发生急性应激障碍的主要影响因素(P0.05,P0.01)。结论脑卒中患者急性应激障碍发生率较高,内向性格及存在偏瘫和吞咽功能障碍的患者更容易发生急性应激障碍。医护人员应及时为高危患者提供个体化治疗及预见性护理,防止脑卒中患者发生急性应激障碍。 相似文献
18.
19.
20.
观察并评估角膜电刺激对糖尿病大鼠前部缺血性视神经病变(AION)模型的影响。方法:实验 研究。健康雄性Sparague-Dawley大鼠40只,随机分组后抽出8只作为正常大鼠组。余下32只先予 以链脲佐菌素腹腔注射建立糖尿病大鼠模型,将造模成功的大鼠随机抽出8只作为糖尿病组,余下 24只糖尿病大鼠采用孟加拉玫瑰红联合532 nm激光方法建立AION大鼠模型。将24只造模成功的 AION大鼠随机分成3组,每组8只,分别为AION模型组,不予任何处理;电刺激组,予以角膜电刺 激(刺激参数为:电流1 mA,频率20 Hz,波宽1 ms/phase,刺激时间1 h,隔日1次,刺激2周);假电 刺激组,电极安放位置与电刺激组相同,仅不接通电源。2周后5组大鼠进行眼底照相、光学相干断 层扫描和视觉诱发电位,然后处死,行视网膜及视神经冰冻切片,苏木精伊红染色观察。数据采用 单因素方差分析和LSD-t检验进行分析。结果:正常大鼠组视盘上半部视网膜厚度为(211±13)μm, 糖尿病大鼠组为(206±16)μm,AION模型组为(240±54)μm,假电刺激组为(216±11)μm,电刺 激组为(198±4)μm,5组视盘上半部视网膜厚度差异有统计学意义(F=2.854,P=0.038)。其中AION 模型组视盘上半部视网膜厚度高于正常组、糖尿病组、电刺激组,差异均有统计学意义(P<0.05); 正常组与糖尿病组差异无统计学意义,AION模型组与假电刺激组未见明显差异。视觉诱发电位示 AION模型组N1潜伏期较电刺激组延长,差异有统计学意义(t=4.1,P<0.001);AION模型组P1潜伏 期较正常组、糖尿病组、假电刺激组、电刺激组延长,差异均有统计学意义(t=4.1、2.5、2.6、3.2, P<0.05);电刺激组N1-P1波幅大于假电刺激组,差异有统计学意义(t=4.0,P<0.001)。结论:角膜电 刺激能促进糖尿病大鼠前部缺血性视神经病变模型肿胀的视盘变薄,加速视盘水肿的消退,同时在 一定程度上改善视功能。 相似文献