全文获取类型
收费全文 | 899728篇 |
免费 | 62527篇 |
国内免费 | 2337篇 |
专业分类
耳鼻咽喉 | 12482篇 |
儿科学 | 28682篇 |
妇产科学 | 26143篇 |
基础医学 | 126601篇 |
口腔科学 | 24686篇 |
临床医学 | 74758篇 |
内科学 | 183283篇 |
皮肤病学 | 18988篇 |
神经病学 | 71394篇 |
特种医学 | 36454篇 |
外国民族医学 | 336篇 |
外科学 | 142117篇 |
综合类 | 19031篇 |
一般理论 | 247篇 |
预防医学 | 64562篇 |
眼科学 | 20083篇 |
药学 | 63812篇 |
中国医学 | 1799篇 |
肿瘤学 | 49134篇 |
出版年
2018年 | 9053篇 |
2017年 | 7161篇 |
2016年 | 7677篇 |
2015年 | 8727篇 |
2014年 | 12372篇 |
2013年 | 19215篇 |
2012年 | 25659篇 |
2011年 | 27267篇 |
2010年 | 16581篇 |
2009年 | 15785篇 |
2008年 | 26130篇 |
2007年 | 27740篇 |
2006年 | 27924篇 |
2005年 | 27450篇 |
2004年 | 26300篇 |
2003年 | 25472篇 |
2002年 | 25060篇 |
2001年 | 41358篇 |
2000年 | 42552篇 |
1999年 | 36267篇 |
1998年 | 9967篇 |
1997年 | 9152篇 |
1996年 | 9083篇 |
1995年 | 8446篇 |
1994年 | 8082篇 |
1993年 | 7584篇 |
1992年 | 28199篇 |
1991年 | 26980篇 |
1990年 | 26408篇 |
1989年 | 25346篇 |
1988年 | 23553篇 |
1987年 | 23170篇 |
1986年 | 22250篇 |
1985年 | 21151篇 |
1984年 | 15806篇 |
1983年 | 13477篇 |
1982年 | 8087篇 |
1979年 | 14589篇 |
1978年 | 10208篇 |
1977年 | 8627篇 |
1976年 | 8147篇 |
1975年 | 8959篇 |
1974年 | 10697篇 |
1973年 | 10182篇 |
1972年 | 9661篇 |
1971年 | 8917篇 |
1970年 | 8584篇 |
1969年 | 8025篇 |
1968年 | 7684篇 |
1967年 | 7087篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Katherine J. Wert Susanne F. Koch Gabriel Velez Chun‐Wei Hsu MaryAnn Mahajan Alexander G. Bassuk Stephen H. Tsang Vinit B. Mahajan 《Human mutation》2019,40(12):2377-2392
Small molecule pharmacological inhibition of dominant human genetic disease is a feasible treatment that does not rely on the development of individual, patient‐specific gene therapy vectors. However, the consequences of protein inhibition as a clinical therapeutic are not well‐studied. In advance of human therapeutic trials for CAPN5 vitreoretinopathy, genetic inactivation can be used to infer the effect of protein inhibition in vivo. We created a photoreceptor‐specific knockout (KO) mouse for Capn5 and compared the retinal phenotype to both wild‐type and an existing Capn5 KO mouse model. In humans, CAPN5 loss‐of‐function (LOF) gene variants were ascertained in large exome databases from 60,706 unrelated subjects without severe disease phenotypes. Ocular examination of the retina of Capn5 KO mice by histology and electroretinography showed no significant abnormalities. In humans, there were 22 LOF CAPN5 variants located throughout the gene and in all major protein domains. Structural modeling of coding variants showed these LOF variants were nearby known disease‐causing variants within the proteolytic core and in regions of high homology between human CAPN5 and 150 homologs, yet the LOF of CAPN5 was tolerated as opposed to gain‐of‐function disease‐causing variants. These results indicate that localized inhibition of CAPN5 is a viable strategy for hyperactivating disease alleles. 相似文献
82.
J.G. Liese C. Schoen M. van der Linden L. Lehmann D. Goettler S. Keller A. Maier F. Segerer M.A. Rose A. Streng 《Clinical microbiology and infection》2019,21(7):857-864
ObjectivesParapneumonic pleural effusions/empyema (PPE/PE) are severe complications of community-acquired pneumonia. We investigated the bacterial aetiology and incidence of paediatric PPE/PE in Germany after the introduction of universal pneumococcal conjugate vaccine (PCV) immunization for infants.MethodsChildren <18 years of age hospitalized with pneumonia-associated PPE/PE necessitating pleural drainage or persisting >7 days were reported to the German Surveillance Unit for Rare Diseases in Childhood between October 2010 and June 2017. All bacteria detected in blood or pleural fluid (by culture/PCR) were included, with serotyping for Streptococcus pneumoniae.ResultsThe median age of all 1447 PPE/PE patients was 5 years (interquartile range 3–10). In 488 of the 1447 children with PPE/PE (34%), 541 bacteria (>40 species) were detected. Aerobic gram-positive cocci accounted for 469 of 541 bacteria detected (87%); these were most frequently Streptococcus pneumoniae (41%), Streptococcus pyogenes (19%) and Staphylococcus aureus (6%). Serotype 3 accounted for 45% of 78 serotyped S. pneumoniae strains. Annual PPE/PE incidence varied between 14 (95%CI 12–16) and 18 (95%CI 16–21) PPE/PE per million children. Incidence of S. pneumoniae PPE/PE decreased from 3.5 (95%CI 2.5–4.6) per million children in 2010/11 to 1.5 (95%CI 0.9–2.4) in 2013/14 (p 0.002), followed by a re-increase to 2.2 (95%CI 1.5–3.2) by 2016/17 (p 0.205).ConclusionsIn the era of widespread PCV immunization, cases of paediatric PPE/PE were still caused mainly by S. pneumoniae and, increasingly, by S. pyogenes. The re-increase in the incidence of PPE/PE overall and in S. pneumoniae-associated PPE/PE indicates ongoing changes in the bacterial aetiology and requires further surveillance. 相似文献
83.
C.G. Giske F. Dyrkell D. Arnellos N. Vestberg S. Hermansson Panna I. Fröding M. Ullberg H. Fang 《Clinical microbiology and infection》2019,21(10):1289.e5-1289.e8
ObjectivesStaphylococcus argenteus has been increasingly reported since the species was defined as a novel staphylococcal species in 2015. This study aims to investigate genetic epidemiological links and antimicrobial susceptibilities of methicillin-resistant S. argenteus isolates recovered in Stockholm.MethodsSixteen methicillin-resistant S. argenteus isolates were identified from a collection of methicillin-resistant Staphylococcus aureus in Stockholm 2007–2018, by using whole-genome sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The genomes of the isolates were investigated by pulsed-field gel electrophoresis, single-nucleotide polymorphism (SNP)-based phylogeny, k-mer analysis, core-genome multi-locus sequence typing (cgMLST), resistance traits and virulence factors. The MICs of 19 antimicrobial agents for each isolate were determined by using the broth microdilution method.ResultsOf the 16 isolates, seven, seven and two isolates were assigned to ST1223, ST2250 and ST2793, respectively, with the S. aureus MLST-scheme. Analyses based on SNPs and cgMLST revealed a likely clonal spread of methicillin-resistant S. argenteus in 2007. Four isolates were found to be resistant to non-β-lactams in antimicrobial susceptibility testing.ConclusionsA transmission event of methicillin-resistant S. argenteus in family was identified by this study. Among our limited number of isolates, non-β-lactam resistance was detected, which highlights the necessity of a continued surveillance on this emerging pathogen. S. argenteus could be correctly identified by MALDI-TOF MS with the updated database, enabling its detection also in clinical laboratories. 相似文献
84.
85.
The birth experience and subsequent maternal caregiving attitudes and behavior: a birth cohort study
Bell A. F. Rubin L. H. Davis J. M. Golding J. Adejumo O. A. Carter C. S. 《Archives of women's mental health》2019,22(5):613-620
Archives of Women's Mental Health - Optimal maternal caregiving is critical for children’s healthy development, yet quality of maternal caregiving may be influenced by a negative birth... 相似文献
86.
87.
Sandra F. Centofanti Rossana P. V. Francisco Sonia T. Phillippi Marco A. K. Galletta Ana M. S. Sousa Agatha S. Rodrigues Rui Curi Maria L. Brizot 《American journal of medical genetics. Part A》2019,179(8):1535-1542
Fetal gastroschisis is a paraumbilical abdominal wall defect with herniation of the abdominal organs. This multifactorial malformation occurs in young pregnant women, and the underlying cause of the disease remains unknown; however, nutritional factors may play a role in its development. This case‐control study explored the association of maternal nutrient intake with the occurrence of gastroschisis. The gastroschisis group (GG) comprised 57 pregnant women with fetuses with gastroschisis, and the control group (CG) comprised 114 pregnant women with normal fetuses matched for maternal age, gestational age, and preconception body mass index classification. Nutritional assessments related to the preconception period were obtained using the food consumption frequency questionnaire, and nutrient intakes were calculated using nutrition programs. The median daily calorie intake was higher (2,382.43 vs. 2,198.81; p = .041) in the GG than in the CG. The median intake of methionine (763.89 vs. 906.34; p = .036) and threonine (1,248.34 vs. 1,437.01; p = .018) was lower in the GG than in the CG. Pregnant women with fetuses with gastroschisis have a diet characterized by higher calorie intake and lower levels of essential amino acids (methionine and threonine) during the preconception period than pregnant women with normal fetuses. 相似文献
88.
89.
Gideon St.Helen Neal L. Benowitz Jasjit S. Ahluwalia Rachel F. Tyndale Newton Addo Steven E. Gregorich Eliseo J. Pérez-Stable Lisa Sanderson Cox 《Journal of the National Medical Association》2019,111(5):509-520
ObjectiveThe study objective was to identify biobehavioral variables associated with greater intake of nicotine and a tobacco carcinogen among Black light smokers who smoke 1 to 10 cigarettes per day (CPD).MethodsWe analyzed baseline data collected from 426 Black light smokers enrolled in Kick It at Swope III (KIS III), a smoking cessation trial for Black smokers. We examined differences in concentrations of tobacco biomarkers, including urinary total nicotine equivalents (TNE) and total 4-(methylnitrosamino)-1-(3)pyridyl-1-butanonol (NNAL; a human carcinogen), across gender, age, plasma nicotine metabolite ratio (NMR), CPD, and measures of tobacco dependence, including time to first cigarette (TFC), using ANOVA.ResultsTobacco biomarker levels were significantly higher among those who smoked more CPD (6–10 vs 1–5 CPD) and those with greater reported physical dependence on tobacco. Concurrently, those who smoked 1–5 CPD smoked each cigarette more intensely than those who smoked 6–10 CPD. While we found no gender differences overall, among those who smoked 1–5 CPD, women had higher NNAL levels compared to men. The rate of nicotine metabolism, measured by the nicotine metabolite ratio, was not significantly related to TNE or NNAL levels.ConclusionAmong Black Light smokers, higher cigarette consumption and greater physical dependence—but not rate of nicotine metabolism, menthol use, or socioeconomic status—were associated with greater toxicant exposure and thus a likely increased risk of tobacco-related diseases. The lack of data on light smokers, and specifically on Blacks, make this observation important given the disproportionate burden of lung cancer in this population. 相似文献
90.