全文获取类型
收费全文 | 9644篇 |
免费 | 700篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 276篇 |
妇产科学 | 267篇 |
基础医学 | 1342篇 |
口腔科学 | 154篇 |
临床医学 | 1031篇 |
内科学 | 1997篇 |
皮肤病学 | 217篇 |
神经病学 | 925篇 |
特种医学 | 197篇 |
外科学 | 1022篇 |
综合类 | 109篇 |
一般理论 | 9篇 |
预防医学 | 1150篇 |
眼科学 | 163篇 |
药学 | 742篇 |
中国医学 | 19篇 |
肿瘤学 | 678篇 |
出版年
2023年 | 94篇 |
2022年 | 164篇 |
2021年 | 338篇 |
2020年 | 211篇 |
2019年 | 295篇 |
2018年 | 333篇 |
2017年 | 202篇 |
2016年 | 261篇 |
2015年 | 300篇 |
2014年 | 367篇 |
2013年 | 489篇 |
2012年 | 746篇 |
2011年 | 760篇 |
2010年 | 437篇 |
2009年 | 345篇 |
2008年 | 585篇 |
2007年 | 589篇 |
2006年 | 564篇 |
2005年 | 509篇 |
2004年 | 432篇 |
2003年 | 416篇 |
2002年 | 382篇 |
2001年 | 96篇 |
2000年 | 86篇 |
1999年 | 95篇 |
1998年 | 81篇 |
1997年 | 72篇 |
1996年 | 49篇 |
1995年 | 47篇 |
1994年 | 44篇 |
1993年 | 31篇 |
1992年 | 67篇 |
1991年 | 62篇 |
1990年 | 65篇 |
1989年 | 46篇 |
1988年 | 61篇 |
1987年 | 49篇 |
1986年 | 52篇 |
1985年 | 61篇 |
1984年 | 34篇 |
1983年 | 34篇 |
1982年 | 28篇 |
1981年 | 30篇 |
1980年 | 32篇 |
1979年 | 45篇 |
1978年 | 22篇 |
1977年 | 36篇 |
1974年 | 21篇 |
1973年 | 29篇 |
1971年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
41.
42.
43.
44.
45.
Women who stop smoking spontaneously prior to prenatal care and predictors of relapse before delivery 总被引:4,自引:0,他引:4
This study explores the experience of pregnant women who quit smoking prior to initiating prenatal care. These "spontaneous quitters" comprised 41% of a socioeconomically and ethnically diverse population of prepregnancy smokers enrolled in a health maintenance organization. Compared to women who were smoking at the start of prenatal care, spontaneous quitters had been lighter smokers, were less likely to have another smoker in their household, indicated a stronger belief in the harmful effect of maternal smoking, had a history of fewer miscarriages, and entered prenatal care earlier. Biochemical validation of smoking status over the course of pregnancy found that 21% of the spontaneous quitters relapsed prior to delivery. Characteristics reported at the first prenatal visit that were associated with maintenance included having achieved cessation for a longer period of time without smoking even a puff, higher self-efficacy for maintenance, stronger belief in the harmful effect of maternal smoking, primigravida, and greater frequency of nausea. The identification of spontaneous quitters and selected intervention for those at greatest risk of relapse is recommended for inclusion in routine prenatal care. 相似文献
46.
J B Mullen 《Neurosurgery》1979,5(4):432-436
Four cases of acute hyperesthesia after spinal trauma are presented. An attempt is made to characterize the natural history of this syndrome. In the three cases with truncal sensory aberration, hyperesthetic zones developed only anteriorly. All four patients demonstrated spontaneous relief of pain within 2 weeks after injury. The pain was modified by transcutaneous stimulation in one case and by l-dopa in another case. It is suggested that the "lesion" responsible for the hyperesthetic response is partial damage to dorsal root fibers at a point medial to the dorsal root ganglion. 相似文献
47.
Miriam B. G. Morrell Claudia Alvarez‐Florez Aiqian Zhang Eugenie S. Kleinerman Hannah Savage Enrica Marmonti Minjeong Park Angela Shaw Keri L. Schadler 《Pediatric blood & cancer》2019,66(9)
Recent studies in mouse models of cancer have shown that exercise improves tumor vascular function, thereby improving chemotherapy delivery and efficacy. However, the mechanisms underlying this improvement remain unclear and the effect of exercise on Ewing sarcoma (ES), a pediatric bone and soft tissue cancer, is unknown. The effect of exercise on tumor vascular hyperpermeability, which inversely correlates with drug delivery to the tumor, has also not been evaluated. We hypothesized that exercise improves chemotherapy efficacy by enhancing its delivery through improving tumor vascular permeability. We treated ES‐bearing mice with doxorubicin with or without moderate treadmill exercise. Exercise did not significantly alter ES tumor vessel morphology. However, compared to control mice, tumors of exercised mice had significantly reduced hyperpermeability, significantly decreased hypoxia, and higher doxorubicin penetration. Compared to doxorubicin alone, doxorubicin plus exercise inhibited tumor growth more efficiently. We evaluated endothelial cell sphingosine‐1‐phosphate receptors 1 and 2 (S1PR1 and S1PR2) as potential mediators of the improved vascular permeability and increased function afforded by exercise. Relative to tumors from control mice, vessels in tumors from exercised mice had increased S1PR1 and decreased S1PR2 expression. Our results support a model in which exercise remodels ES vasculature to reduce vessel hyperpermeability, potentially via modulation of S1PR1 and S1PR2, thereby improving doxorubicin delivery and inhibiting tumor growth more than doxorubicin alone does. Our data suggest moderate aerobic exercise should be tested in clinical trials as a potentially useful adjuvant to standard chemotherapy for patients with ES. 相似文献
48.
49.
The Social Learning Theory concepts of self-efficacy and outcome expectations were used to study physician practice regarding patients' smoking, alcohol problems, OTC drug problems, and illicit drug use in a random sample of Texas primary care physicians. The highest proportion of physicians took histories and counseled patients regarding the abuse of cigarettes, followed by alcohol, OTC drugs, and illicit drugs. Outside referral was most likely for illicit drugs, followed by alcohol, OTC drugs, and smoking. Multivariate discriminant analysis showed year of graduation, specialty, self-efficacy, and outcome expectation for patient compliance to be predictive of many of the behavior/practice level combinations. More recently trained physicians, internists, and family practice specialists were more likely to practice in the substance abuse areas. Self-efficacy and outcome expectation were positively related to history-taking and counseling and negatively related to outside referral. Interventions to increase physicians' self-efficacy and expectations for patient compliance and to provide more realistic expectations for treatment "success" are needed, especially for physicians who are not recently trained. Further research to clarify the process by which physicians' cognitions of self-efficacy and outcome expectations influence their practice behavior is also recommended. 相似文献
50.
ngel Gimnez-Richarte Mabel Ortiz de Salazar Cristina Arbona María P. Gimnez-Richarte Miriam Collado Pedro L. Fernndez Francisco Quiles Carlos Clavijo Pascual Marco Jose-Manuel Ramos-Rincon 《Trasfusione del sangue》2022,20(4):267
BackgroundBlood transfusion centres should understand the epidemiology of emerging diseases that are transmissible through the transfusion of blood components. The risk of transmission of arboviruses through this route has become apparent in recent years. The aim of our study is to summarise the reported prevalence (viraemic rate, seroprevalence and/or antigen detection) of Chikungunya (CHIKV), Dengue (DENV) and Zika (ZIKV) viruses in blood donors according to screening test used and world region.Materials and methodsWe conducted a systematic literature review and meta-analysis having searched for information in the main bibliographic databases (MEDLINE, Embase, and Scopus). The prevalence for each of the viruses was calculated according to the screening test used and geographic location.ResultsWe included 18 records on CHIKV, 71 on DENV, and 27 on ZIKV. The highest prevalences of RNA for CHIKV were 1.9% in Puerto Rico (2014), 1.0% in Thailand (2009), and 1.0% in French Polynesia (2014–15). The highest prevalences of RNA for DENV were 5.5% in Saudi Arabia (2015–16), 2.3% in Madeira, Portugal (2012–13), and 0.6% in Brazil (2012). The highest prevalences of RNA for ZIKV were 2.8% in French Polynesia (2013–14), 2.7% in Brazil (2015–16), and 1.8% in Martinique (2016). Overall seroprevalence, as assessed by IgG antibodies, was 21.6% for CHIKV, 24.0% for DENV, and 5.1% for ZIKV.DiscussionOur study shows a high proportion of donors who are viraemic and asymptomatic, especially during outbreaks, with prevalences surpassing 5% for DENV, 1% for CHIKV, and 2% for ZIKV. These data confirm a clear threat to blood transfusion safety. The elevated seroprevalence for these three arboviruses is also indicative of their wide circulation in populations, correlating with an increased risk of infected but asymptomatic donors. Health centres and institutions must address this threat, especially in tropical regions where the biggest outbreaks occur. 相似文献