全文获取类型
收费全文 | 24779篇 |
免费 | 1564篇 |
国内免费 | 734篇 |
专业分类
耳鼻咽喉 | 148篇 |
儿科学 | 1408篇 |
妇产科学 | 310篇 |
基础医学 | 2001篇 |
口腔科学 | 46篇 |
临床医学 | 3071篇 |
内科学 | 3335篇 |
皮肤病学 | 104篇 |
神经病学 | 1286篇 |
特种医学 | 1037篇 |
外国民族医学 | 2篇 |
外科学 | 4898篇 |
综合类 | 3322篇 |
现状与发展 | 2篇 |
预防医学 | 2064篇 |
眼科学 | 38篇 |
药学 | 2408篇 |
14篇 | |
中国医学 | 615篇 |
肿瘤学 | 968篇 |
出版年
2024年 | 65篇 |
2023年 | 338篇 |
2022年 | 667篇 |
2021年 | 939篇 |
2020年 | 837篇 |
2019年 | 796篇 |
2018年 | 840篇 |
2017年 | 762篇 |
2016年 | 854篇 |
2015年 | 868篇 |
2014年 | 1646篇 |
2013年 | 1692篇 |
2012年 | 1468篇 |
2011年 | 1553篇 |
2010年 | 1271篇 |
2009年 | 1234篇 |
2008年 | 1260篇 |
2007年 | 1257篇 |
2006年 | 1150篇 |
2005年 | 961篇 |
2004年 | 813篇 |
2003年 | 668篇 |
2002年 | 583篇 |
2001年 | 527篇 |
2000年 | 416篇 |
1999年 | 395篇 |
1998年 | 349篇 |
1997年 | 298篇 |
1996年 | 251篇 |
1995年 | 217篇 |
1994年 | 192篇 |
1993年 | 172篇 |
1992年 | 183篇 |
1991年 | 136篇 |
1990年 | 156篇 |
1989年 | 118篇 |
1988年 | 122篇 |
1987年 | 101篇 |
1986年 | 115篇 |
1985年 | 136篇 |
1984年 | 109篇 |
1983年 | 80篇 |
1982年 | 108篇 |
1981年 | 80篇 |
1980年 | 57篇 |
1979年 | 48篇 |
1978年 | 46篇 |
1977年 | 33篇 |
1976年 | 30篇 |
1974年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
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
3.
4.
《Journal of vascular and interventional radiology : JVIR》2020,31(3):378-387
PurposeTo determine if cone-beam CT and digital subtraction angiography analysis of pelvic arterial anatomy has predictive value for radiation exposure and technical success of prostatic artery embolization (PAE).Materials and MethodsThis prospective, nonrandomized, single-center study included 104 consecutive patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia. Cone-beam CT was performed in 160/208 (76.9%) hemipelves to determine prostatic artery (PA) origin. Classification of pelvic arterial tortuosity was possible in 73/104 (70.2%) patients. Learning curves of 2 interventionalists who performed 86.5% of PAEs were analyzed.ResultsTortuosity of pelvic arteries was classified as mild in 25 (34.2%) patients median age 64 years, moderate in 40 (54.8%) patients median age 69 years, and severe in 8 (11.0%) patients median age 70 years (mild vs moderate, P = .002; mild vs severe, P = .019); median fluoroscopy times were 24, 36, and 46 minutes (P = .008, P = .023); median contrast volumes were 105, 122.5, and 142 mL (P = .029, P = .064); and bilateral PAE rates were 84.0%, 77.5%, and 62.5% (P = .437), respectively. PA origin from superior vesical artery was most frequent (27.5%) and showed higher dose area product (median 402.4 vs 218 Gy ∙ cm2, P = .033) and fluoroscopy time (median 42.5 vs 27 min, P = .01) compared with PA origin from obturator artery, which was least frequent. Interventionalist experience revealed significant impact on procedure times (median 159 vs 130 min, P = .006).ConclusionsTortuosity of pelvic arteries was more frequent in older patients and predicted worse technical outcomes of PAE. PA origin from obturator artery was associated with lower dose area product and fluoroscopy time, especially compared with PA origin from superior vesical artery. Interventionalist experience showed significant influence on technical outcome. 相似文献
5.
《Vaccine》2020,38(42):6508-6516
BackgroundPneumococcal conjugate vaccine (PCV) effectiveness against radiographic pneumonia in South Asia is unknown. Bangladesh introduced PCV10 in 2015 using a three dose primary series (3 + 0). We sought to measure PCV10 effectiveness for two or more vaccine doses on radiographic pneumonia among vaccine-eligible children in rural Bangladesh.MethodsWe conducted a matched case-control study over two years from 2015 to 2017 using clinic and community controls in three subdistricts of Sylhet, Bangladesh. Cases were vaccine eligible 3–35 month olds at Upazila Health Complex outpatient clinics with World Health Organization-defined radiographic primary endpoint pneumonia (radiographic pneumonia). Clinic controls were matched to cases within a one week time window by age, sex, and clinic and had an illness unlikely to be Streptococcus pneumoniae; community controls were healthy and similarly matched within a one week time window by age and sex, and distance from the clinic. We estimated adjusted vaccine effectiveness (aVE) using conditional logistic regression.ResultsWe matched 1262 cases with 2707 clinic and 2461 community controls. Overall, aVE using clinic controls was 21.4% (95% confidence interval, −0.2%, 38.4%) for ≥2 PCV10 doses and among 3–11 month olds was 47.3% (10.5%, 69.0%) for three doses. aVE increased with higher numbers of doses in clinic control sets (p = 0.007). In contrast, aVE using community controls was 7.6% (95% confidence interval, −22.2%, 30.0%) for ≥2 doses. We found vaccine introduction in the study area faster and less variable than expected with 75% coverage on average, which reduced power. Information bias may also have affected community controls.ConclusionsClinic control analyses show PCV10 prevented radiographic pneumonia in Bangladesh, especially among younger children receiving three doses. While both analyses were underpowered, community control enrollment – compared to clinic controls – was more difficult in a complex, pluralistic healthcare system. Future studies in comparable settings may consider alternative study designs. 相似文献
6.
7.
目的 研究胎膜早破孕妇生殖道感染情况及对妊娠结局的影响。方法 选择2014年5月至2015年1月住院分娩的胎膜早破孕妇70例为早破组,同期无胎膜早破70例为对照组,检测两组生殖道病原微生物感染情况,并比较两组的妊娠结局。结果 早破组生殖道感染阳性率高于对照组,且剖宫产率,母体发生产后出血,绒毛膜羊膜炎,胎儿窘迫及新生儿窒息发生率均高于对照组,差异均有统计学意义(P<0.05)。结论 生殖道感染是胎膜早破最常见的诱因,积极筛查及治疗孕妇生殖道感染可以减少相关产科并发症的发生。 相似文献
8.
9.
《European Urology Supplements》2015,14(1):9-11
The main goal in the management of patients with vesicoureteral reflux (VUR) is the preservation of kidney function by minimizing the risk of pyelonephritis. By defining and analyzing the risk factors for each patient depending on age, sex, grade of reflux, lower urinary tract dysfunction, anatomic abnormalities, and kidney status, it is possible to identify those patients with a potential risk of upper urinary tract infection and resulting renal scarring. This paper gives a brief overview of the European Association of Urology guidelines for the management and treatment of VUR in children. These guidelines are based on the best currently available knowledge and evidence. 相似文献
10.
Emmi Helle Aldo Córdova-Palomera Tiina Ojala Priyanka Saha Praneetha Potiny Stefan Gustafsson Erik Ingelsson Michael Bamshad Deborah Nickerson Jessica X. Chong University of Washington Center for Mendelian Genomics Euan Ashley James R. Priest 《Genetic epidemiology》2019,43(2):215-226
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes. 相似文献