全文获取类型
收费全文 | 47309篇 |
免费 | 3412篇 |
国内免费 | 195篇 |
专业分类
耳鼻咽喉 | 375篇 |
儿科学 | 1517篇 |
妇产科学 | 1215篇 |
基础医学 | 6671篇 |
口腔科学 | 616篇 |
临床医学 | 5071篇 |
内科学 | 9928篇 |
皮肤病学 | 883篇 |
神经病学 | 5612篇 |
特种医学 | 1159篇 |
外科学 | 4180篇 |
综合类 | 387篇 |
一般理论 | 58篇 |
预防医学 | 5690篇 |
眼科学 | 632篇 |
药学 | 3023篇 |
中国医学 | 87篇 |
肿瘤学 | 3812篇 |
出版年
2024年 | 59篇 |
2023年 | 652篇 |
2022年 | 1096篇 |
2021年 | 2150篇 |
2020年 | 1303篇 |
2019年 | 1784篇 |
2018年 | 2050篇 |
2017年 | 1367篇 |
2016年 | 1525篇 |
2015年 | 1666篇 |
2014年 | 2036篇 |
2013年 | 2643篇 |
2012年 | 4231篇 |
2011年 | 4183篇 |
2010年 | 2121篇 |
2009年 | 1856篇 |
2008年 | 2968篇 |
2007年 | 2943篇 |
2006年 | 2809篇 |
2005年 | 2597篇 |
2004年 | 2310篇 |
2003年 | 2068篇 |
2002年 | 1757篇 |
2001年 | 204篇 |
2000年 | 160篇 |
1999年 | 229篇 |
1998年 | 352篇 |
1997年 | 263篇 |
1996年 | 220篇 |
1995年 | 182篇 |
1994年 | 133篇 |
1993年 | 128篇 |
1992年 | 82篇 |
1991年 | 86篇 |
1990年 | 76篇 |
1989年 | 72篇 |
1988年 | 62篇 |
1987年 | 46篇 |
1986年 | 51篇 |
1985年 | 43篇 |
1984年 | 54篇 |
1983年 | 49篇 |
1982年 | 36篇 |
1981年 | 42篇 |
1980年 | 29篇 |
1979年 | 23篇 |
1978年 | 17篇 |
1977年 | 22篇 |
1975年 | 10篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
992.
Elisa Swanljung Laura Tapiovaara Liisa Lehtoranta Harri Mäkivuokko Merja Roivainen Riitta Korpela 《Acta oto-laryngologica》2015,135(8):824-830
Conclusion: Lactobacillus rhamnosus GG (L.GG) was present in all adenoids of children receiving the L. GG product. However, since L.GG was also found from the placebo group, one cannot confirm its effect on the occurrence of rhinovirus (RV) or enterovirus (EV). Objectives: The present study was conducted to determine whether a 3-week oral consumption of L.GG would lead to presence of the probiotic in adenoid tissue. Furthermore, nasopharyngeal RV and EV findings and symptom data were investigated. Method: The tissue samples were collected from 40 children aged 1–5 years about to undergo adenotomy due to recurrent acute/secretory otitis media, chronic rhinitis, or recurrent sinusitis after a 3-week daily consumption of L.GG (n = 20) or placebo (n = 20). Strain-specific real-time PCR was used to detect RV, EV, and L.GG in adenoid tissue. Results: L.GG was recovered in the adenoid sample in 100% of children in the L.GG group and in 76% in the placebo group (p = 0.07). Both RV and EV were found in 31% of children in the L.GG group and in 18% of children in the placebo group (p = 0.67). The majority of the positive samples were positive for both RV and EV. Study diaries showed no differences in symptoms between the groups. 相似文献
993.
Giuseppe Attanasio Edoardo Covelli Laura Cagnoni Eleonora Masci Davide Rosati Edoardo Di Porto 《Acta oto-laryngologica》2015,135(10):969-973
Conclusions: The present study shows that AGE, DELAY, and PTA_PRE may be considered factors influencing therapeutic success in intra-tympanic steroid therapy. Objective: The aim of the study is to evaluate the relationship between the therapeutic success of intra-tympanic prednisolone therapy and age, in patients affected by idiopathic sudden sensorineural hearing loss (ISSNHL), considering the influence of factors such as delay, gender, and pure tone average (PTA) pre-therapy. Method: This retrospective study involved 402 consecutive patients, affected by unilateral ISSNHL between January 2009 and January 2014. Patients were divided into two groups based on age: group one with 94 patients aged over 65 years and group two with all 402 patients enrolled in the study, including those over 65. Results: PTA recorded before the beginning of the therapy (PTA_PRE) in group one was worse than for group two. In both groups the therapy was significantly effective in improving hearing thresholds, even if PTA_PRE was significant and negatively correlated with success rate. This effect disappeared within the population over 65. On average, each day of DELAY from the onset of hearing loss to the beginning of therapy cuts almost 2% of the possibility to recover. AGE was negative and significant when specified continuously for group two. 相似文献
994.
Post-traumatic stress disorder (PTSD) is a serious problem for children exposed to intimate partner violence (IPV). Recent changes to diagnostic criteria for PTSD include a reduction in avoidance symptom criteria from three to one and the separation of emotional numbing from avoidance symptoms, thus creating a need to better understand how avoidance symptoms of PTSD present themselves in young children. This study evaluated 56 children aged four to six as they participated in an intervention for mothers and children exposed to IPV. Therapists documented behaviours indicative of avoidance symptoms during group sessions. Data were analysed and coded into symptom categories and thematically emergent domains. Results demonstrated that avoidance symptoms fell into three separate categories: physical avoidance, emotional avoidance, and changing topics. Additionally, the data support the Diagnostic and Statistical Manual of Mental Disorders (5th edition) change to remove emotional numbing from the avoidance symptom category. These results give insight into how to develop more targeted treatments for PTSD as well as improve the assessment and diagnosis of PTSD symptoms in preschoolers. 相似文献
995.
D. Max Crowley Laura Griner Hill Margaret R. Kuklinski Damon E. Jones 《Prevention science》2014,15(6):789-798
In response to growing interest in economic analyses of prevention efforts, a diverse group of prevention researchers, economists, and policy analysts convened a scientific panel, on “Research Priorities in Economic Analysis of Prevention” at the 19th annual conference of the Society for Prevention Research. The panel articulated four priorities that, if followed in future research, would make economic analyses of prevention efforts easier to compare and more relevant to policymakers and community stakeholders. These priorities are: (1) increased standardization of evaluation methods, (2) improved economic valuation of common prevention outcomes, (3) expanded efforts to maximize evaluation generalizability and impact as well as (4) enhanced transparency and communicability of economic evaluations. In this paper, we define three types of economic analyses in prevention, provide context and rationale for these four priorities as well as related sub-priorities, and discuss the challenges inherent in meeting them. 相似文献
996.
Maja Derlink Barbara Pipan Petra Pavlovčič Laura E. Jones Vladimir Meglič William O. C. Symondson Meta Virant-Doberlet 《Conservation Genetics Resources》2014,6(4):933-935
Eleven microsatellite markers were developed for the leafhoppers of the genus Aphrodes using shotgun pyrosequencing and will be used to study the genetic diversity, population structure and gene flow within and between species in this genus in order to assess their conservation status. The number of alleles per locus ranged from 3 to 10, while observed and expected heterozygosity values varied from 0.421–1.000 to 0.542–0.876, respectively. Cross-species amplification was successful among the four congeners. 相似文献
997.
Sven Rainer Kantelhardt Naureen Keric Jens Conrad Amr Nimer Raymund Woo Laura Varich Alf Giese 《Acta neurochirurgica》2014,156(9):1799-1805
Background
Two-dimensional image guidance and navigation can help to reduce the number of misplaced pedicle screws, but do not completely prevent misplacement. This experimental, retrospective, non-inferiority study was designed to evaluate and compare the efficacy of a novel 3D imaging technique versus conventional postoperative CT-scan, for intra-operative determination of pedicle screw position accuracy.Methods
The capacity of C-OnSite® to intraoperatively assess screw placement was evaluated in 28 clinical cases and 23 deliberately misplaced screws in a cadaver model, and compared to placement accuracy determined by standard CT. The position of each implant, as viewed by both modalities, was graded by three neurosurgeons, one orthopaedic-surgeon and one radiologist. The intermodal variance determined the difference between CT- and C-OnSite® results for each observer, while the inter-observer variance measured the difference between ratings of the same modality by different observers.Results
C-OnSite® successfully assessed 120/138 screws (25/28 cases). Mean procedural fluoroscopy time was 132?±?51s, and 40?±?16s per C-OnSite® scan. The average inter-modality variance was ,15 % with mismatches >1° between C-OnSite® and the gold-standard imaging technique in only 2 % of the comparisons. Average inter-observer variances were about similar (12 % for CT and 18 % for C-OnSite®), with deviations of >1° reaching 1 % for CT and 3 % for C-OnSite®. Individual variances between experienced only observers differed even less.Conclusions
C-OnSite® is a feasible, reliable and intuitive means of intraoperatively visualizing pedicle screw positions and might render the majority of postoperative CTs superfluous. C-OnSite® might help avoid re-operations for screw re-positioning. 相似文献998.
Louise L. Dunn Philippa J.L. Simpson Hamish C. Prosser Laura Lecce Gloria S.C. Yuen Andrew Buckle Daniel P. Sieveking Laura Z. Vanags Patrick R. Lim Renee W.Y. Chow Yuen Ting Lam Zoe Clayton Shisan Bao Michael J. Davies Nadina Stadler David S. Celermajer Roland Stocker Christina A. Bursill John P. Cooke Martin K.C. Ng 《Diabetes》2014,63(2):675-687
Impaired angiogenesis in ischemic tissue is a hallmark of diabetes. Thioredoxin-interacting protein (TXNIP) is an exquisitely glucose-sensitive gene that is overexpressed in diabetes. As TXNIP modulates the activity of the key angiogenic cytokine vascular endothelial growth factor (VEGF), we hypothesized that hyperglycemia-induced dysregulation of TXNIP may play a role in the pathogenesis of impaired angiogenesis in diabetes. In the current study, we report that high glucose–mediated overexpression of TXNIP induces a widespread impairment in endothelial cell (EC) function and survival by reducing VEGF production and sensitivity to VEGF action, findings that are rescued by silencing TXNIP with small interfering RNA. High glucose–induced EC dysfunction was recapitulated in normal glucose conditions by overexpressing either TXNIP or a TXNIP C247S mutant unable to bind thioredoxin, suggesting that TXNIP effects are largely independent of thioredoxin activity. In streptozotocin-induced diabetic mice, TXNIP knockdown to nondiabetic levels rescued diabetes-related impairment of angiogenesis, arteriogenesis, blood flow, and functional recovery in an ischemic hindlimb. These findings were associated with in vivo restoration of VEGF production to nondiabetic levels. These data implicate a critical role for TXNIP in diabetes-related impairment of ischemia-mediated angiogenesis and identify TXNIP as a potential therapeutic target for the vascular complications of diabetes. 相似文献
999.
Laura M. Enomoto Darren C. Hill Peter W. Dillon David C. Han Christopher S. Hollenbeak 《The Journal of surgical research》2014
Background
Carotid endarterectomy (CEA) has been performed since the 1950s and remains one of the most common surgical procedures in the United States. The procedure is performed by cardiothoracic, general, neurologic, and vascular surgeons. This study uses data from the National Surgical Quality Improvement Program (NSQIP) to examine the outcomes after CEA when performed by general or vascular surgeons.Materials and methods
Data included 34,493 CEAs from years 2005 to 2010 recorded in the NSQIP database. Primary outcomes measured were length of stay, 30-d mortality, surgical site infection, cerebrovascular accident, myocardial infarction, and blood transfusion requirement. Secondary outcomes measured were the remaining intraoperative outcomes from the NSQIP database.Results
After controlling for patient and surgical characteristics, patients treated by general surgeons did not have a significantly different LOS or 30-d mortality than those treated by vascular surgeons. Patients of general surgeons had nearly twice the risk of acquiring a surgical site infection (odds ratio [OR] = 1.94; P = 0.012), >1.5 times the risk of cerebrovascular accident (OR = 1.56; P = 0.008), and >1.8 times the risk of blood transfusion (OR = 1.85; P = 0.017) than those of vascular surgeons. Patients of general surgeons had less than half the risk of having a myocardial infarction (OR = 0.34; P = 0.031) than those of vascular surgeons.Conclusions
Surgical specialty is associated with a wide range of postoperative outcomes after CEA. Additional research is needed to explore practice and cultural differences across surgical specialty that may lead to outcome differences. 相似文献1000.
Giuseppe d'Ambrosio Laura del Prete Chiara Grimaldi Arianna Bertocchini Cristina Lo Zupone Lidia Monti Jean de Ville de Goyet 《Journal of pediatric surgery》2014