全文获取类型
收费全文 | 47549篇 |
免费 | 3972篇 |
国内免费 | 111篇 |
专业分类
耳鼻咽喉 | 381篇 |
儿科学 | 1994篇 |
妇产科学 | 1303篇 |
基础医学 | 6825篇 |
口腔科学 | 978篇 |
临床医学 | 6566篇 |
内科学 | 9265篇 |
皮肤病学 | 899篇 |
神经病学 | 4825篇 |
特种医学 | 1084篇 |
外科学 | 4289篇 |
综合类 | 408篇 |
一般理论 | 62篇 |
预防医学 | 5758篇 |
眼科学 | 675篇 |
药学 | 2665篇 |
2篇 | |
中国医学 | 54篇 |
肿瘤学 | 3599篇 |
出版年
2024年 | 41篇 |
2023年 | 398篇 |
2022年 | 444篇 |
2021年 | 1277篇 |
2020年 | 948篇 |
2019年 | 1400篇 |
2018年 | 1535篇 |
2017年 | 1211篇 |
2016年 | 1346篇 |
2015年 | 1411篇 |
2014年 | 1797篇 |
2013年 | 2653篇 |
2012年 | 3684篇 |
2011年 | 3809篇 |
2010年 | 2095篇 |
2009年 | 1854篇 |
2008年 | 3084篇 |
2007年 | 3170篇 |
2006年 | 3138篇 |
2005年 | 2941篇 |
2004年 | 2856篇 |
2003年 | 2602篇 |
2002年 | 2344篇 |
2001年 | 392篇 |
2000年 | 293篇 |
1999年 | 335篇 |
1998年 | 536篇 |
1997年 | 398篇 |
1996年 | 360篇 |
1995年 | 349篇 |
1994年 | 276篇 |
1993年 | 278篇 |
1992年 | 202篇 |
1991年 | 172篇 |
1990年 | 163篇 |
1989年 | 123篇 |
1988年 | 142篇 |
1987年 | 109篇 |
1986年 | 112篇 |
1985年 | 114篇 |
1984年 | 108篇 |
1983年 | 113篇 |
1982年 | 132篇 |
1981年 | 129篇 |
1980年 | 105篇 |
1979年 | 62篇 |
1978年 | 71篇 |
1977年 | 59篇 |
1976年 | 48篇 |
1972年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
982.
983.
984.
Mikhail-Paul Cardinal Samuel Blais Anne Dumas Vincent Hamilton Eric Larose Stéphanie LeBlanc Julie Déry Heynric Grotenhuis Tim Leiner Wadi Mawad Cassandre Têtu Steven C. Greenway Nicole Dahl David Patton Arif Hussain Christian Drolet Gérald Gahide Paul Farand Frederic Dallaire 《The Canadian journal of cardiology》2021,37(3):417-424
BackgroundReference values for cardiac magnetic resonance imaging (cMRI) in children and young adults are scarce. This leads to risk stratification of patients with congenital heart diseases being based on volumes indexed to body surface area (BSA). We aimed to produce cMRI Z score equations for ventricular volumes in children and young adults and to test whether indexing to BSA resulted in an incorrect assessment of ventricular dilation according to sex, body composition, and growth.MethodsWe retrospectively included 372 subjects aged < 26 years with either normal hearts or conditions with no impact on ventricular volumes (reference group), and 205 subjects with repaired tetralogy of Fallot (TOF) aged < 26 years. We generated Z score equations by means of multivariable regression modelling. Right ventricular dilation was assessed with the use of Z scores and compared with indexing to BSA in TOF subjects.ResultsVentricular volume Z scores were independent from age, sex, and anthropometric measurements, although volumes indexed to BSA showed significant residual association with sex and body size. In TOF subjects, indexing overestimated dilation in growing children and underestimated dilation in female compared with male subjects, and in overweight compared with lean subjects.ConclusionsIndexed ventricular volumes measured with cMRI did not completely adjust for body size and resulted in a differential error in the assessment of ventricular dilation according to sex and body size. Our proposed Z score equations solved this problem. Future studies should evaluate if ventricular volumes expressed as Z scores have a better prognostic value than volumes indexed to BSA. 相似文献
985.
Lajos Szak D vid N meth Nelli Farkas Szabolcs Kiss R ka Zsuzsa D m t r Marie Anne Engh P ter Hegyi Balint Eross r s Papp 《World journal of gastroenterology : WJG》2022,28(30):4201-4210
986.
Karvandi Elika Hanrahan John Gerrard Khan Danyal Zaman Boloux Pierre-Marc Bremner Fion Cabrilo Ivan Dorward Neil Grieve Joan Jackson Sue Jimenez Glenda Serrano Inma Nowak Victoria Anne Kolias Angelos Baldeweg Stephanie E. Marcus Hani Joseph 《Pituitary》2022,25(4):673-683
Pituitary - Pituitary adenomas affect patients’ quality-of-life (QoL) across several domains, with long-term implications even following gross-total resection or disease remission. While... 相似文献
987.
Brigtsen AK Kasper DL Baker CJ Jennings HJ Guttormsen HK 《The Journal of infectious diseases》2002,185(9):1277-1284
Types Ia and Ib group B streptococcal (GBS) capsular polysaccharides (PSs) are structural isomers but are antigenically distinct. Immunization of healthy adults with GBS type Ia PS-tetanus toxoid (Ia-TT) or Ib-TT glycoconjugate vaccines induced > or = 4-fold increases in specific immunoglobulin G to the heterologous PS in more than two-thirds of subjects. Ib-TT vaccine-induced IgG bound with substantially higher affinity to homologous (Ib) than to heterologous (Ia) PS and promoted opsonophagocytic killing of GBS type Ib but not type Ia organisms. The failure of the Ib-TT- and Ia-TT-induced human antibodies to kill bacteria of the cross-reactive serotype contrasts with the results of previous studies in animals. Inhibition enzyme-linked immunosorbent assays demonstrated that Ib-TT-induced IgG to the homologous PS bound mainly to native Ib PS, whereas the cross-reactive antibodies recognized both native and derivative PSs. These results indicate that GBS Ia and Ib PSs should be included in a multivalent conjugate vaccine to prevent GBS disease. 相似文献
988.
Guthmann JP Pittet A Lesage A Imwong M Lindegardh N Min Lwin M Zaw T Annerberg A de Radiguès X Nosten F 《Tropical medicine & international health : TM & IH》2008,13(1):91-98
Objective To assess the efficacy of chloroquine in the treatment of Plasmodium vivax malaria in in Dawei District, southern Myanmar.
Methods Enrolled patients at Sonsinphya clinic >6 months of age were assessed clinically and parasitologically every week for 28 days. To differentiate new infections from recrudescence, we genotyped pre- and post-treatment parasitaemia. Blood chloroquine was measured to confirm resistant strains.
Results Between December 2002 and April 2003, 2661 patients were screened, of whom 252 were included and 235 analysed. Thirty-four per cent (95% CI: 28.1–40.6) of patients had recurrent parasitaemia and were considered treatment failures. 59.4% of these recurrences were with a different parasite strain. Two (0.8%) patients with recurrences on day 14 had chloroquine concentrations above the threshold of 100 ng/ml and were considered infected with chloroquine resistant parasites. 21% of failures occurred during the first 3 weeks of follow-up: early recurrence and median levels of blood chloroquine comparable to those of controls suggested P. vivax resistance.
Conclusions Plasmodium vivax resistance to chloroquine seems to be emerging in Dawei, near the Thai-Burmese border. While chloroquine remains the first-line drug for P. vivax infections in this area of Myanmar, regular monitoring is needed to detect further development of parasite resistance. 相似文献
Methods Enrolled patients at Sonsinphya clinic >6 months of age were assessed clinically and parasitologically every week for 28 days. To differentiate new infections from recrudescence, we genotyped pre- and post-treatment parasitaemia. Blood chloroquine was measured to confirm resistant strains.
Results Between December 2002 and April 2003, 2661 patients were screened, of whom 252 were included and 235 analysed. Thirty-four per cent (95% CI: 28.1–40.6) of patients had recurrent parasitaemia and were considered treatment failures. 59.4% of these recurrences were with a different parasite strain. Two (0.8%) patients with recurrences on day 14 had chloroquine concentrations above the threshold of 100 ng/ml and were considered infected with chloroquine resistant parasites. 21% of failures occurred during the first 3 weeks of follow-up: early recurrence and median levels of blood chloroquine comparable to those of controls suggested P. vivax resistance.
Conclusions Plasmodium vivax resistance to chloroquine seems to be emerging in Dawei, near the Thai-Burmese border. While chloroquine remains the first-line drug for P. vivax infections in this area of Myanmar, regular monitoring is needed to detect further development of parasite resistance. 相似文献
989.
Audrey Dionne Anne Fournier Nagib Dahdah Dominic Abrams Paul Khairy Sylvia Abadir 《The Canadian journal of cardiology》2018,34(1):66-72
Background
QT-interval variations in response to exercise-induced increases in heart rate have been reported in children and adults in the diagnosis of long QT syndrome (LQTS). A quick standing challenge has been proposed as an alternative provocative test in adults, with no pediatric data yet available.Methods
A standing test was performed in 100 healthy children (mean age, 9.7 ± 3.1 years) after 10 minutes in a supine position with continuous electrocardiographic recording. QT intervals were measured at baseline, at maximal heart rate, at maximal QT, and at each minute of a 5-minute recovery while standing. Measurements were taken in leads II/V5 and were corrected for heart rate (QTc).Results
On standing, the heart rate increased by 29 ± 10 beats per minute (bpm). The QT interval was similar at baseline and on standing (394 ± 34 ms vs 394 ± 34 ms; P = 1.0). However, QTc increased from 426 ± 21 to 509 ± 41 ms (P < 0.001). The 95th percentile for QTc at baseline and maximal heart rate was 457 ms and 563 ms, respectively. At 1 minute of recovery, the QT interval was shorter (375 ± 31 ms) compared with baseline (394 ± 34 ms; P < 0.001) and standing (394 ± 34 ms; P < 0.001). QTc reached baseline values after 1 minute of recovery and remained stable thereafter (423 ± 23 ms at 1 minute; 426 ± 22 ms at 5 minutes; P = 1.0).Conclusions
This first characterization of QTc changes on standing in children shows substantial alterations, which are greater than those seen in adults. Two-thirds of the children would have been misclassified as having LQTS by adult criteria, indicating the need to create child-specific standards. 相似文献990.
McGarrigle CA Mercer CH Fenton KA Copas AJ Wellings K Erens B Johnson AM 《AIDS (London, England)》2005,19(1):77-84
OBJECTIVES: To estimate the prevalence of, and identify factors associated with, HIV testing in Britain. DESIGN: A large, stratified probability sample survey of sexual attitudes and lifestyles. METHODS: A total of 12,110 16-44 year olds completed a computer-assisted face-to-face interview and self-interview. Self-reports of HIV testing, i.e. the timing, reasons for and location of testing, were included. RESULTS: A total of 32.4% of men and 31.7% of women reported ever having had an HIV test, the majority of whom were tested through blood donation. When screening for blood donation and pregnancy were excluded, 9.0% of men and 4.6% of women had had a voluntary confidential HIV test (VCT) in the past 5 years. However, one third of injecting drug users and men who have sex with men had a VCT in the past 5 years. VCT in the past 5 years was significantly associated with age, residence, ethnicity, self-perceived HIV risk, reporting greater numbers of sexual partners, new sexual partners from abroad, previous sexually transmitted infection diagnosis, and injecting non-prescribed drugs for men and women, and same-sex partners (men only). Whereas sexually transmitted disease clinics were important sites for VCT, general practice accounted for almost a quarter of VCT. CONCLUSION: HIV testing is relatively common in Britain; however, it remains largely associated with population-based blood donation and antenatal screening programmes. In contrast, VCT remains highly associated with high-risk (sexual or drug-injecting) behaviours or population sub-groups at high risk. Strategies to reduce undiagnosed prevalent HIV infection will require further normalization and wider uptake of HIV testing. 相似文献