全文获取类型
收费全文 | 2675篇 |
免费 | 139篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 112篇 |
妇产科学 | 49篇 |
基础医学 | 310篇 |
口腔科学 | 60篇 |
临床医学 | 188篇 |
内科学 | 380篇 |
皮肤病学 | 41篇 |
神经病学 | 149篇 |
特种医学 | 166篇 |
外科学 | 257篇 |
综合类 | 318篇 |
预防医学 | 157篇 |
眼科学 | 148篇 |
药学 | 310篇 |
中国医学 | 50篇 |
肿瘤学 | 127篇 |
出版年
2023年 | 12篇 |
2022年 | 41篇 |
2021年 | 65篇 |
2020年 | 35篇 |
2019年 | 53篇 |
2018年 | 60篇 |
2017年 | 42篇 |
2016年 | 64篇 |
2015年 | 82篇 |
2014年 | 100篇 |
2013年 | 99篇 |
2012年 | 140篇 |
2011年 | 143篇 |
2010年 | 125篇 |
2009年 | 100篇 |
2008年 | 133篇 |
2007年 | 122篇 |
2006年 | 128篇 |
2005年 | 104篇 |
2004年 | 119篇 |
2003年 | 89篇 |
2002年 | 81篇 |
2001年 | 49篇 |
2000年 | 55篇 |
1999年 | 50篇 |
1998年 | 55篇 |
1997年 | 66篇 |
1996年 | 64篇 |
1995年 | 39篇 |
1994年 | 33篇 |
1993年 | 18篇 |
1992年 | 47篇 |
1991年 | 39篇 |
1990年 | 30篇 |
1989年 | 41篇 |
1988年 | 38篇 |
1987年 | 27篇 |
1986年 | 23篇 |
1985年 | 19篇 |
1984年 | 35篇 |
1983年 | 18篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 12篇 |
1979年 | 17篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1974年 | 11篇 |
1973年 | 13篇 |
1972年 | 12篇 |
排序方式: 共有2835条查询结果,搜索用时 15 毫秒
991.
Shukla SK Prasad KN Tripathi A Singh A Saxena A Ghoshal UC Krishnani N Husain N 《The Brazilian journal of infectious diseases》2011,15(6):583-590
Helicobacter pylori and Epstein-Barr virus (EBV) infections are common worldwide. Although H. pylori infection is a major factor in gastroduodenal diseases, its role in association with EBV infection is unknown.ObjectiveTo study the association of H. pylori infection and EBV DNA load in patients with gastroduodenal diseases.MethodsBiopsy samples were collected from 200 adult patients [non-ulcer dyspepsia (NUD) 100, peptic ulcer disease (PUD) 50, gastric carcinoma (GC) 50] undergoing upper gastrointestinal endoscopy. H. pylori infection was diagnosed by rapid urease test, culture, histopathology, PCR and Q-PCR. EBV DNA was detected by non-polymorphic Epstein- Barr nuclear antigen-1 (EBNA-1) gene based Q-PCR.ResultsIn patients with GC and PUD, EBV DNA was detected more often than NUD (GC versus NUD = 90% versus 37%, p < 0.001; PUD versus NUD = 70% versus 37%, p < 0.001). The dual prevalence of H. pylori infection and EBV DNA was significantly higher in patients with GC and PUD than in those with NUD. Median copy number of EBV DNA was considerably higher in GC and PUD than NUD (p < 0.01). The copy number of EBV DNA was significantly higher in H. pylori infected patients (p = 0.015). The number of ureA gene copies was also found to be significantly higher in PUD and NUD with presence of EBV DNA. However, in GC no significant difference was seen between EBV positive and negative status.ConclusionThere was a trend for higher EBV DNA load in H. pylori positive individuals suggesting a probable role of H. pylori in modulating the conversion of EBV to its lytic phase. 相似文献
992.
993.
This paper examines mapping and related data-gathering at geographical locations of vulnerable urban groups with regard to risky sexual behaviors and alcohol/drug use in the capital city of Delhi. The aim is to describe the situations of special geographic locations and sub-groups in relation to alcohol/drug use and risks of HIV/STI infections. The study was part of a community program for alcohol and drug users in slum communities in West and East Delhi carried out by the National Drug Dependence Treatment Centre (NDDTC) of the All India Institute of Medical Science (AIIMS), New Delhi, India. As part of a WHO multi-centered qualitative study among selected groups, mapping was done at different sites concerning alcohol use, social contexts, involvement in sexual risk behavior, availability of sex partners and related factors. Easy access to alcohol and drugs, accompanied by availability of sex workers appeared as compound risk factors in the study sites. Reported risky sexual behaviors included nonuse or irregular use of condoms, multiple sex partners, group sex, and anal sex with hijras (eunuchs). 相似文献
994.
ObjectiveTo determine distribution of arthropods in processed rice products such as rice flour and rice cereal-based infant food.MethodsRandom samples of rice flour and rice cereal-based infant food purchased from commercial outlets were examined for the presence of arthropods using a modified Berlese Tullgren Funnel Method. Mites were mounted prior to identification and weevils were directly identified.ResultsFor non-expired products, infestation was found in 6.7% of rice flour and none was found in rice cereal-based infant food samples. The arthropods found in the flour samples were Cheyletus spp., Suidasia pontifica (S. pontifica), Tarsonemus spp., Tyrophagus putrescentiae (T. putrescentiae), Sitophilus granarius (S. granarius) and Sitophilus oryzae (S. oryzae). Others which cannot be identified were Oribatid and Prostigmatid mites. The most common mites in rice flour were Tarsonemus spp. (69.1%), followed by S. pontifica (18.2%). For expired products, only one sample of rice cereal-based infant food was infested and the infestation was by mites of the family Tydeidae.ConclusionsThis study demonstrates the presence of 4 allergenic species of S. pontifica, T. putrescentiae, S. granarius and S. oryzae in rice flour. These arthropods can contribute to the incidence of anaphylaxis upon consumption by atopic individuals. There was no infestation of arthropods in rice cereal-based infant food surveyed except for an expired product in a moderate rusty tin container. 相似文献
995.
FT Aweeka A Stek BM Best C Hu D Holland A Hermes SK Burchett J Read M Mirochnick EV Capparelli 《HIV medicine》2010,11(4):232-238
Background
Pregnancy may alter protein binding (PB) of highly bound protease inhibitors due to changes in plasma concentrations of albumin and α‐1 acid glycoprotein (AAG). Small changes in PB can greatly impact the fraction of drug unbound (FU) exerting pharmacological effect. We report lopinavir (LPV) PB during third trimester (antepartum, AP) compared to ≥1.7 weeks postpartum (PP) to determine if FU changes compensate for reduced total concentrations reported previously.Methods
P1026s enrolled women receiving LPV/ritonavir, soft gel capsules 400/100 mg or 533/133 mg twice daily. LPV FU, albumin and AAG were determined AP and PP.Results
AP/PP samples were available from 29/25 women respectively with all but one woman receiving the same dose AP/PP. LPV FU was increased 18% AP vs. PP (mean 0.96±0.16% AP vs. 0.82±0.21% PP, P=0.001). Mean protein concentrations were reduced AP (AAG=477 mg/L; albumin=3.28 mg/dL) vs. PP (AAG=1007 mg/L; albumin=3.85 mg/dL) (P<0.0001 for each comparison). AAG concentration correlated with LPV binding. Total LPV concentration did not correlate with LPV FU AP or PP. However, higher LPV concentration PP was associated with reduced PB and higher FU after adjustment for AAG.Conclusions
LPV FU was higher and AAG lower AP vs. PP. The 18% increase in LPV FU AP is smaller than the reduction in total LPV concentration reported previously and is not of sufficient magnitude to eliminate the need for an increased dose during pregnancy.996.
Rajendra Prasad Tripathi Arun Batra Sameer Kaushik 《Indian journal of gastroenterology》2002,21(3):105-109
BACKGROUND AND AIMS: Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive imaging technique for evaluating the biliary and pancreatic ducts. MRCP has reached a level of resolution and reliability where it may replace diagnostic endoscopic retrograde cholangio-pancreatography (ERCP). We analyzed the results of MRCP in adult patients with biliary or pancreatic disease, and compared the findings with those at surgery or on ERCP. METHODS: Data of 150 patients who underwent MRCP with both single slab and multislice rapid acquisition with relaxation enhancement sequences with half-fourier acquisition single-shot turbo spin echo techniques were analyzed. Patients were divided into four groups according to reason for referral for MRCP: obstructive jaundice (n = 65), chronic/acute pancreatitis (n = 25), screening prior to laparoscopic cholecystectomy (n = 20), and failed ERCP (n = 40). RESULTS: MRCP could accurately identify the level of biliary obstruction in 58 of 61 patients. Characterization of benign or malignant nature of a stricture was possible in 30 of 32 patients when findings of both MRCP and magnetic resonance imaging were analyzed together. MRCP revealed the morphology of the entire pancreatic duct in 13 of 15 patients having ductal changes on endoscopic retrograde pancreatography. CONCLUSION: MRCP has high sensitivity and specificity for detection of biliary dilatation, calculi, strictures and anatomical variants. 相似文献
997.
Insulin-like growth factor-binding protein 5 (Igfbp5) compromises survival, growth, muscle development, and fertility in mice 总被引:11,自引:0,他引:11 下载免费PDF全文
Salih DA Tripathi G Holding C Szestak TA Gonzalez MI Carter EJ Cobb LJ Eisemann JE Pell JM 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(12):4314-4319
The insulin-like growth factors (IGFs) are essential for development; bioavailable IGF is tightly regulated by six related IGF-binding proteins (IGFBPs). Igfbp5 is the most conserved and is developmentally up-regulated in key lineages and pathologies; in vitro studies suggest that IGFBP-5 functions independently of IGF interaction. Genetic ablation of individual Igfbps has yielded limited phenotypes because of substantial compensation by remaining family members. Therefore, to reveal Igfbp5 actions in vivo, we generated lines of transgenic mice that ubiquitously overexpressed Igfbp5 from early development. Significantly increased neonatal mortality, reduced female fertility, whole-body growth inhibition, and retarded muscle development were observed in Igfbp5-overexpressing mice. The magnitude of the response in individual transgenic lines was positively correlated with Igfbp5 expression. Circulating IGFBP-5 concentrations increased a maximum of only 4-fold, total and free IGF-I concentrations increased up to 2-fold, and IGFBP-5 was detected in high M(r) complexes; however, no detectable decrease in the proportion of free IGF-I was observed. Thus, despite only modest changes in IGF and IGFBP concentrations, the Igfbp5-overexpressing mice displayed a phenotype more extreme than that observed for other Igfbp genetic models. Although growth retardation was obvious prenatally, maximal inhibition occurred postnatally before the onset of growth hormone-dependent growth, regardless of Igfbp5 expression level, revealing a period of sensitivity to IGFBP-5 during this important stage of tissue programming. 相似文献
998.
Improved clinical outcome with transjugular intrahepatic portosystemic stent-shunt utilizing polytetrafluoroethylene-covered stents 总被引:2,自引:0,他引:2
Tripathi D Ferguson J Barkell H Macbeth K Ireland H Redhead DN Hayes PC 《European journal of gastroenterology & hepatology》2006,18(3):225-232
BACKGROUND AND AIMS: Transjugular intrahepatic portosystemic stent-shunt (TIPSS) with standard uncovered stents has a 50% one-year primary patency rate, and is complicated by hepatic encephalopathy in 35% of patients. Newer covered stents appear to have improved patency. This large study aimed to assess the shunt function and clinical efficacy of polytetrafluoroethylene-covered stents in a single centre. METHODS: A total of 316 patients with uncovered stents before the introduction of covered stents (group 1) and 157 patients with the Viatorr Gore polytetrafluoroethylene-covered stents at the time of TIPSS creation (group 2) were studied. RESULTS: The mean follow-up was 22.8+/-25.4 and 13.1+/-12.5 months, respectively (P<0.01). Shunt insufficiency was greater in group 1 [54 versus 8% at 12 months; relative hazard (RH) 8.6; 95% confidence interval (CI) 4.8-15.5; P<0.001]. The incidence of variceal rebleeding was greater in group 1 (11 versus 6% at 12 months; RH 2.4; 95% CI 1.1-5.1; P<0.05). The incidence of hepatic encephalopathy was greater in group 1 (32 versus 22% at 12 months; RH 1.5; 95% CI 1.1-2.3; P<0.05). Mortality was similar in the two groups. CONCLUSION: The Viatorr type of polytetrafluoroethylene-covered stent results in vastly improved patency compared with uncovered stents, with reduced rates of variceal rebleeding and hepatic encephalopathy. This type of covered stent has the potential for superior clinical efficacy compared with uncovered stents. 相似文献
999.
Bwnjamin CH Wong SK Lam 《胃肠病学》2002,7(1):64-64
胃癌为世界第二位常见癌症,1996年新发病例为100万,且75%的新发病例见于亚洲,因此是亚洲国家面临的一个重要问题。与大多数癌症一样,其病因尚不清楚。通常认为其发病机制是多因素的,包括饮食。环境。细菌和病毒感染等。其中,幽门螺杆菌(H. pylori)感染起着重要作用。亚洲发病率最高的国家包括中国。日本和韩国,世界上其他高发地区包括前苏联。南美热带国家。Carribeans和南欧。发病率呈不同模式,即使在同一个国家,亦有很大差异。中国的许多地方如福建省长乐地区有很高的发病率,而有些地方发病率却相当的低。尽管饮食是胃癌发病中的一个重要… 相似文献
1000.
Tan To Cheung Sheung Tat Fan See Ching Chan Kenneth SH Chok Ferdinand SK Chu Caroline R Jenkins Regina CL Lo James YY Fung Albert CY Chan William W Sharr Simon HY Tsang Wing Chiu Dai Ronnie TP Poon Chung Mau Lo 《World journal of gastroenterology : WJG》2013,19(20):3083-3089
AIM:To analyze whether high-intensity focused ultrasound(HIFU) ablation is an effective bridging therapy for patients with hepatocellular carcinoma(HCC).METHODS:From January 2007 to December 2010,49 consecutive HCC patients were listed for liver transplantation(UCSF criteria).The median waiting time for transplantation was 9.5 mo.Twenty-nine patients received transarterial chemoembolization(TACE) as a bringing therapy and 16 patients received no treatment before transplantation.Five patients received HIFU ablation as a bridging therapy.Another five patients with the same tumor staging(within the UCSF criteria) who received HIFU ablation but not on the transplant list were included for comparison.Patients were comparable in terms of Child-Pugh and model for end-stage liver disease scores,tumor size and number,and cause of cirrhosis.RESULTS:The HIFU group and TACE group showed no difference in terms of tumor size and tumor number.One patient in the HIFU group and no patient in the TACE group had gross ascites.The median hospital stay was 1 d(range,1-21 d) in the TACE group and two days(range,1-9 d) in the HIFU group(P < 0.000).No HIFU-related complication occurred.In the HIFU group,nine patients(90%) had complete response and one patient(10%) had partial response to the treatment.In the TACE group,only one patient(3%) had response to the treatment while 14 patients(48%) had stable disease and 14 patients(48%) had progressive disease(P = 0.00).Seven patients in the TACE group and no patient in the HIFU group dropped out from the transplant waiting list(P = 0.559).CONCLUSION:HIFU ablation is safe and effective in the treatment of HCC for patients with advanced cirrhosis.It may reduce the drop-out rate of liver transplant candidate. 相似文献