全文获取类型
收费全文 | 77216篇 |
免费 | 4410篇 |
国内免费 | 1053篇 |
专业分类
耳鼻咽喉 | 455篇 |
儿科学 | 3183篇 |
妇产科学 | 1429篇 |
基础医学 | 8883篇 |
口腔科学 | 1957篇 |
临床医学 | 5879篇 |
内科学 | 14854篇 |
皮肤病学 | 498篇 |
神经病学 | 7813篇 |
特种医学 | 1293篇 |
外国民族医学 | 1篇 |
外科学 | 7719篇 |
综合类 | 6001篇 |
现状与发展 | 5篇 |
一般理论 | 7篇 |
预防医学 | 9571篇 |
眼科学 | 844篇 |
药学 | 7235篇 |
50篇 | |
中国医学 | 3104篇 |
肿瘤学 | 1898篇 |
出版年
2023年 | 1224篇 |
2022年 | 1967篇 |
2021年 | 2997篇 |
2020年 | 2544篇 |
2019年 | 4403篇 |
2018年 | 3556篇 |
2017年 | 2933篇 |
2016年 | 2046篇 |
2015年 | 1890篇 |
2014年 | 3427篇 |
2013年 | 4111篇 |
2012年 | 3105篇 |
2011年 | 3429篇 |
2010年 | 2776篇 |
2009年 | 2645篇 |
2008年 | 2677篇 |
2007年 | 2549篇 |
2006年 | 2071篇 |
2005年 | 1772篇 |
2004年 | 1516篇 |
2003年 | 1297篇 |
2002年 | 1051篇 |
2001年 | 862篇 |
2000年 | 774篇 |
1999年 | 687篇 |
1998年 | 661篇 |
1997年 | 584篇 |
1996年 | 537篇 |
1995年 | 506篇 |
1994年 | 460篇 |
1993年 | 385篇 |
1992年 | 372篇 |
1991年 | 302篇 |
1990年 | 291篇 |
1989年 | 241篇 |
1988年 | 205篇 |
1986年 | 225篇 |
1985年 | 1652篇 |
1984年 | 2668篇 |
1983年 | 2422篇 |
1982年 | 1818篇 |
1981年 | 1938篇 |
1980年 | 1618篇 |
1979年 | 1384篇 |
1978年 | 1206篇 |
1977年 | 688篇 |
1976年 | 1145篇 |
1975年 | 990篇 |
1974年 | 825篇 |
1973年 | 792篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
《Anales de pediatría (Barcelona, Spain : 2003)》2020,92(4):200-207
IntroductionMore than five million children have been conceived by assisted reproductive techniques (ART) around the world. Most authors agree that there are no differences in psychomotor development in comparison to naturally conceived children. However, these results are still contradictory.ObjectiveTo determine whether children born from a cohort of ART-clinical gestations have a higher risk of suffering neurodevelopmental disorders in comparison to a control group. The potential associated ART-factors associated were also determined.Material and methodsThe study included the assessment of children up to 3 years old conceived by ART, and born from a cohort of women treated by the reproduction unit of a public hospital from May 2012 to May 2014. A simultaneous assessment was made of matched controls, by following the newborn naturally conceived after the ART-case, of the same group of maternal age, gestational age, and type of gestation.ResultsThere were 243 clinical gestations and 267 ART-newborns, of which 231 were assessed (87%). A simultaneous assessment was carried out in 208/230 controls (90%). There were no differences in neurodevelopmental disorders (global developmental delay, autism spectrum or language delay). Multivariate analysis of potential ART factors only showed an association between transfer of frozen embryos with language delay that has not been previously described.ConclusionsThere were no differences between groups after adjusting the results according to maternal age, multiple pregnancy, and other possible confounding factors, supporting that the role of these factors may be more relevant than the ART itself. The association between frozen embryo transfer and language delay has not been previously described. Thus, more studies are needed to confirm or refute this relationship. 相似文献
13.
目的:调查心脏瓣膜置换术后患者的出院准备度现状,并分析其影响因素。方法:于2018年9月至2019年3月用一般资料、出院准备度量表、出院指导质量量表对139例瓣膜置换术后患者进行调查。结果:心脏瓣膜置换术后患者的出院准备度总分为(89.51±8.53)分,与出院指导质量呈正相关;多元回归分析显示,主要照顾者、婚姻状况、工作状态、服药种类、出院指导质量为出院准备度影响因素。结论:心脏瓣膜置换术后患者的出院准备度有待提高,患者感知的个人状态得分不理想;护士应鼓励患者配合进行早期康复,强化出院指导,采取有效措施提供康复信息,满足患者及其家属需求,提高出院准备度。 相似文献
14.
目的 按照国家计划抽验要求,评价国内不同企业生产的注射用盐酸柔红霉素的质量。方法 按国家标准检验与探索性研究相结合,对抽验样品进行检验,对检验结果进行统计分析。结果 共抽取样品17批次,按国家标准检验合格率100.0%。探索性研究对主要杂质的来源与结构进行了研究;建立溶液的澄清度检查方法;对包材相容性及稳定性进行了考察。结论 目前国内注射用盐酸柔红霉素总体质量较好;现行标准有待进一步提高,建议现行标准修订有关物质检查方法,增加特定杂质的控制,增加溶液的澄清度检查;建议企业优化生产工艺,以提高产品质量。 相似文献
15.
16.
17.
18.
Susan E. Hickman Alexia M. Torke Greg A. Sachs Rebecca L. Sudore Anne L. Myers Qing Tang Giorgos Bakoyannis Bernard J. Hammes 《Journal of pain and symptom management》2019,57(6):1143-1150.e5
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST. 相似文献
19.
Sho Yagishita 《Psychiatry and clinical neurosciences》2020,74(2):91-98
Pharmacological studies of antidepressants and atypical antipsychotics have suggested a role of dopamine and serotonin signaling in depression. However, depressive symptoms and treatment effects are difficult to explain based simply on brain‐wide decrease or increase in the concentrations of these molecules. Recent animal studies using advanced neuronal manipulation and observation techniques have revealed detailed dopamine and serotonin dynamics that regulate diverse aspects of motivation‐related behavior. Dopamine and serotonin transiently modulate moment‐to‐moment behavior at timescales ranging from sub‐second to minutes and also produce persistent effects, such as reward‐related learning and stress responses that last longer than several days. Transient and sustained effects often exhibit specific roles depending on the projection sites, where distinct synaptic and cellular mechanisms are required to process the neurotransmitters for each transient and sustained timescale. Therefore, it appears that specific aspects of motivation‐related behavior are regulated by distinct synaptic and cellular mechanisms in specific brain regions that underlie the transient and sustained effects of dopamine and serotonin signaling. Recent clinical studies have implied that subjects with depressive symptoms show impaired transient and sustained signaling functions; moreover, they exhibit heterogeneity in depressive symptoms and neuronal dysfunction. Depressive symptoms may be explained by the dysfunction of each transient and sustained signaling mechanism, and distinct patterns of impairment in the relevant mechanisms may explain the heterogeneity of symptoms. Thus, detailed understanding of dopamine and serotonin signaling may provide new insight into depressive symptoms. 相似文献
20.
《Vaccine》2022,40(11):1594-1605
In addition to providing pathogen-specific immunity, vaccines can also confer nonspecific effects (NSEs) on mortality and morbidity unrelated to the targeted disease. Immunisation with live vaccines, such as the BCG vaccine, has generally been associated with significantly reduced all-cause infant mortality. In contrast, some inactivated vaccines, such as the diphtheria, tetanus, whole-cell pertussis (DTPw) vaccine, have been controversially associated with increased all-cause mortality especially in female infants in high-mortality settings. The NSEs associated with BCG have been attributed, in part, to the induction of trained immunity, an epigenetic and metabolic reprograming of innate immune cells, increasing their responsiveness to subsequent microbial encounters. Whether non-live vaccines such as DTPw induce trained immunity is currently poorly understood. Here, we report that immunisation of mice with DTPw induced a unique program of trained immunity in comparison to BCG immunised mice. Altered monocyte and DC cytokine responses were evident in DTPw immunised mice even months after vaccination. Furthermore, splenic cDCs from DTPw immunised mice had altered chromatin accessibility at loci involved in immunity and metabolism, suggesting that these changes were epigenetically mediated. Interestingly, changing the order in which the BCG and DTPw vaccines were co-administered to mice altered subsequent trained immune responses. Given these differences in trained immunity, we also assessed whether administration of these vaccines altered susceptibility to sepsis in two different mouse models. Immunisation with either BCG or a DTPw-containing vaccine prior to the induction of sepsis did not significantly alter survival. Further studies are now needed to more fully investigate the potential consequences of DTPw induced trained immunity in different contexts and to assess whether other non-live vaccines also induce similar changes. 相似文献