全文获取类型
收费全文 | 6694篇 |
免费 | 478篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 248篇 |
妇产科学 | 126篇 |
基础医学 | 1248篇 |
口腔科学 | 77篇 |
临床医学 | 754篇 |
内科学 | 1344篇 |
皮肤病学 | 225篇 |
神经病学 | 679篇 |
特种医学 | 128篇 |
外科学 | 743篇 |
综合类 | 37篇 |
一般理论 | 2篇 |
预防医学 | 353篇 |
眼科学 | 75篇 |
药学 | 405篇 |
中国医学 | 20篇 |
肿瘤学 | 710篇 |
出版年
2023年 | 40篇 |
2022年 | 69篇 |
2021年 | 100篇 |
2020年 | 98篇 |
2019年 | 122篇 |
2018年 | 150篇 |
2017年 | 112篇 |
2016年 | 139篇 |
2015年 | 164篇 |
2014年 | 185篇 |
2013年 | 289篇 |
2012年 | 462篇 |
2011年 | 505篇 |
2010年 | 279篇 |
2009年 | 291篇 |
2008年 | 456篇 |
2007年 | 541篇 |
2006年 | 468篇 |
2005年 | 500篇 |
2004年 | 466篇 |
2003年 | 431篇 |
2002年 | 405篇 |
2001年 | 68篇 |
2000年 | 40篇 |
1999年 | 65篇 |
1998年 | 82篇 |
1997年 | 80篇 |
1996年 | 70篇 |
1995年 | 63篇 |
1994年 | 56篇 |
1993年 | 36篇 |
1992年 | 22篇 |
1991年 | 27篇 |
1990年 | 22篇 |
1989年 | 24篇 |
1988年 | 28篇 |
1987年 | 22篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1982年 | 22篇 |
1981年 | 8篇 |
1980年 | 19篇 |
1977年 | 7篇 |
1975年 | 9篇 |
1974年 | 9篇 |
1973年 | 7篇 |
1971年 | 8篇 |
1968年 | 7篇 |
排序方式: 共有7194条查询结果,搜索用时 15 毫秒
981.
Bancel B Esteve J Souquet JC Toyokuni S Ohshima H Pignatelli B 《World journal of gastroenterology : WJG》2006,12(7):1005-1012
AIM:To investigate the extent of oxidative stress in pre-neoplastic and neoplastic gastric mucosa in relation totheir pathological criteria and histological subtypes.METHODS:A total of 104 gastric adenocarcinomas from98 patients(88 infiltrative and 16 intraepithelial tumors)were assessed immunohistochemically for expression ofiNOS and occurrence of nitrotyrosine(NTYR)-containingproteins and 8-hydroxy-2'-deoxyguanosine(8-OH-dG)-containing DNA,as markers of NO production anddamages to protein and DNA.RESULTS:Tumor cells staining for iNOS,NTYR and8-OH-dG were detected in 41%,62% and 50% ofinfiltrative carcinoma,respectively.The three markerswere shown for the first time in intraepithelial carcinoma.The expression of iNOS was significantly more frequentin tubular carcinoma(TC)compared to diffuse carcinoma(DC)(54% vs 18%;P=0.008)or in polymorphouscarcinoma(PolyC)(54% vs 21%;P=0.04).NTYRstaining was obviously more often found in TC thanthat in PolyC(72% vs 30%;P=0.03).There was atendency towards a higher rate of iNOS staining whendistant metastasis(pM)was present.In infiltrativeTC,the presence of oxidative stress markers was notsignificantly correlated with histological grade,density ofinflammation,the depth of infiltration(pT),lymph nodesdissemination(pN)and pathological stages(pTNM). CONCLUSION:The iNOS-oxidative pathway may playan important role in TC,but moderately in PolyC and DC.DNA oxidation and protein nitration occur in the threesubtypes.Based on the significant differences of NTYRlevels,TC and PolyC appear as two distinct subtypes. 相似文献
982.
Guillaume Gorincour Audrey Aschero Catherine Desvignes François Portier Brigitte Bourlière-Najean Alix Ruocco-Angari Philippe Devred Nathalie Colavolpe Bertrand Roquelaure Arnaud Delarue Philippe Petit 《Pediatric radiology》2010,40(6):920-926
Approximately one fourth of cases of inflammatory bowel disease (IBD) occur during childhood and children are more prone than their adult counterparts to have severe disease at presentation. To investigate these diseases MR imaging is no longer an emerging tool. Numerous reviews and articles have been published on this topic underlying the advances of imaging but also the complexity and the financial impact on management of such diseases. In children it seems reasonable to consider US as the first imaging examination to perform, especially when the diagnosis of IBD is unknown. However, we believe that recent and future technical progress, especially the ability of MR to display reproducible data, and the need for gold standard evaluation of new medical therapies will increase the role of MR enterography. 相似文献
983.
984.
Stéphane Chabrier Elie Saliba Sylvie Nguyen The Tich Aude Charollais Marie-Noëlle Varlet Brigitte Tardy Emilie Presles Cyrille Renaud Dominique Allard Béatrice Husson Pierre Landrieu 《European journal of paediatric neurology》2010,14(3):206-213
ObjectivesMany questions remain regarding the mechanism of perinatal stroke.MethodsIn a series of 100 prospectively enrolled term neonates with symptomatic arterial ischemic stroke, we explored family antecedents, pregnancy and delivery conditions and clinical presenting features and distinguished features of the 50 larger infants with the remainder. Cardiac and cervical arterial imaging were performed in 70 and 51 cases.ResultsPrevious fetal loss, first pregnancy, primiparity, twin-gestation, cesarean and traumatic delivery, neonatal distress, male sex and premature rupture of membranes were statistically more common than in the general population. Normal pregnancy proportion and mean birthweight were in the normal range, arguing against a vasculo-placental origin in the majority. Furthermore, there was an excess of large babies. The larger infants were more subject to suffer from acute perinatal events, with a trend for an excess of neonatal distress (p = 0.065) and for more severe presenting features (p = 0.027), while the lighter were more likely to have experienced longstanding obstetrical risk factors such as complicated pregnancy (p = 0.047) and tobacco exposure (p = 0.028). Cervical MR angiography showed an internal carotid occlusion in two babies, whereas echo-Doppler was always normal; in one case the two methods were discordant. Echocardiography was non-informative.InterpretationThe data from this prospective cohort of neonates with stroke confirm that many obstetrical and perinatal factors are risk determinants. They also suggest that birthweight and gender may be biomarkers of two populations of neonates with different pathological mechanisms. MR angiography appears more sensitive than echo-Doppler for the exploration of the neonatal cervical vasculature. 相似文献
985.
Ibanez Martin P Fresard A Cuilleron M Peoc'h M Patouillard B Prost B Audigier JC 《Gastroentérologie clinique et biologique》2006,30(4):605-608
Localized macronodular tuberculosis of the liver is rare. In this location antituberculosis therapy results in a favorable clinical evolution in 100% of cases. We report a pseudo-tumoral form of this condition with no specific clinical, biological or radiological data. After ultrasound guided needle aspiration cytology suggesting metastasis, the correct diagnosis was obtained on liver biopsy after laparotomy. After what was probably inadequate therapy, the enlargement of several hepatic and splenic macronodules was observed. After two years and eight months, the clinical condition of the patient was good but radiological features remained. The risk of diagnostic errors and the therapeutic difficulties in the zones where the incidence of tuberculosis is low should be noted. 相似文献
986.
Impact of radiation schedule and chemotherapy duration in definitive chemoradiotherapy regimen for esophageal cancer 总被引:2,自引:0,他引:2
Di Fiore F Lecleire S Galais MP Rigal O Vié B David I Hamidou H Paillot B Jacob JH Michel P 《Gastroentérologie clinique et biologique》2006,30(6-7):845-851
Impact of radiotherapy (RT) schedule on local response and duration of the 5-fluorouracil/cisplatin (5 FU/CDDP) chemotherapy (CT) on m are still questioning in chemoradiotherapy (CRT) regimen in esophageal carcinoma.AIM: Evaluate two RT schedules and two different CT durations by a retrospective comparison of the CRT regimens used by two centres between 1994 and 2000. METHODS: In centre I (regimen I), patients received 2 CT concomitantly to a continuous RT (50 Gy/25 fractions/5 weeks). In centre II (regimen II), patients received 6 CT, 3 were concomitant to a split course RT (20 Gy/10 fractions x 3 courses) and 3 CT were delivered after CRT. RESULTS: A total of 129 patients were included, 74 in centre I and 55 in centre II respectively. Main patient characteristics were similar between the two groups. Clinical complete response to CRT was significantly more frequent in regimen I (83.8% vs 65.4%; P=0.02). The median overall survival (OS) was 20 months in regimen I and 22 months in regimen II (NS). During follow-up, responder patients to CRT in regimen II experienced significant fewer metastasis (51.6% vs 27.8%; P=0.03) with a trend to an increased 5-year survival (19.4% vs 11.3%) and OS (26.5 vs 21.0 months) (NS). Grade 3-4 toxicities were not different. CONCLUSION: Clinical complete response to CRT was significantly more frequent with a continuous RT whereas additional CT after CRT significantly reduced metastasis occurrence. CRT regimen in esophageal carcinoma may be more effective using a continuous RT schedule and additional CT courses after CRT completion. 相似文献
987.
988.
989.
Braibant M Brunet S Costagliola D Rouzioux C Agut H Katinger H Autran B Barin F 《AIDS (London, England)》2006,20(15):1923-1930
OBJECTIVE: Previous studies have shown that broadly neutralizing antibodies (NAb) are more frequent in long-term non-progressors (LTNP) than in other HIV-1 infected patients, but nothing is known about the envelope regions targeted by these broadly NAb. We investigated whether the breadth of neutralizing activity of sera was associated with the presence of specific antibodies (2F5- and/or 4E10-like, b12-like or 2G12-like antibodies) directed against conserved epitopes known to be involved in broad neutralization. METHODS: We assessed the ability of sera from 67 LTNP of the French ANRS cohort (ANRS CO15) to neutralize four heterologous primary isolates of four various clades. Competitive and non-competitive ELISA were developed for the specific comparison of levels of antibodies against these specific epitopes in neutralizing and non-neutralizing sera from LTNP. RESULTS: We found that higher 2G12-like antibody levels were significantly associated with the broadest neutralizing activity in sera from LTNP. Levels of 2G12-like antibodies were higher in the sera that neutralized the four isolates than in the others, with a median of 5.7 microg/ml [interquartile range (IQR), 2.7-9.3 microg/ml] versus 2.3 microg/ml (IQR, 1.1-3.9 microg/ml) (Mann-Whitney test, P = 0.03). Levels of antibodies against the other targeted envelope epitopes did not differ significantly between broadly and non-broadly neutralizing sera. CONCLUSION: These results suggest that the antigenicity of the "silent face" of gp120 that exposes the 2G12 epitope should be analysed in more detail, to find ways to induce broadly neutralizing antibodies. 相似文献
990.
Lin YL Mettling C Portalès P Réant B Robert-Hebmann V Reynes J Clot J Corbeau P 《AIDS (London, England)》2006,20(10):1369-1377
OBJECTIVE AND DESIGN: The intensity of replication of CCR5-using HIV-1 strains is highly dependent on the number of CCR5 molecules on the surface of CD4-positive T cells. The molecular mechanisms responsible for this phenomenon remained so far unclear. As CCR5 co-receptors are coupled to G alpha i and G alpha q proteins, we tested the hypothesis that the activation triggered through these proteins secondary to the interaction between the viral envelope and CCR5 could account for the effect of the level of CCR5 expression on HIV-1 production. METHODS: We transduced the wild-type or a G-protein signalling-defective CCR5 gene into CD4/CCR5 HOS cells and peripheral blood mononuclear cells. The effect on cell activation in presence of a CCR5-binding chemokine and on HIV infection was monitored by measuring calcium mobilization and p24 antigen production, respectively. The role of G alpha i protein signalling was tested by adding pertussis toxin to the cell cultures or by transfecting small interfering (si) RNAs into the HOS cells. RESULTS: The over-expression of the wild-type form, but not of a G-protein signalling-defective form of CCR5, on the surface of CCR5 expressing peripheral blood mononuclear cells markedly increased their infectability. In addition, both pertussis toxin and G alpha i 1-specific siRNA drastically inhibited R5 infection. CONCLUSIONS: The signalling through G alpha i-protein induced upon R5 virion binding to CCR5 is responsible for the difference in HIV-1 infectability between CD4-positive T cells expressing low or high levels of cell surface CCR5 density. This observation sheds new light on the physiopathology of HIV infection, and opens new therapeutic opportunities targeting G alpha i signalling. 相似文献