全文获取类型
收费全文 | 22202篇 |
免费 | 1195篇 |
国内免费 | 115篇 |
专业分类
耳鼻咽喉 | 272篇 |
儿科学 | 492篇 |
妇产科学 | 487篇 |
基础医学 | 2829篇 |
口腔科学 | 598篇 |
临床医学 | 1723篇 |
内科学 | 5913篇 |
皮肤病学 | 536篇 |
神经病学 | 1971篇 |
特种医学 | 562篇 |
外科学 | 3504篇 |
综合类 | 108篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 1571篇 |
眼科学 | 415篇 |
药学 | 1126篇 |
中国医学 | 44篇 |
肿瘤学 | 1356篇 |
出版年
2023年 | 168篇 |
2022年 | 375篇 |
2021年 | 837篇 |
2020年 | 372篇 |
2019年 | 731篇 |
2018年 | 861篇 |
2017年 | 486篇 |
2016年 | 498篇 |
2015年 | 581篇 |
2014年 | 792篇 |
2013年 | 1110篇 |
2012年 | 1815篇 |
2011年 | 1732篇 |
2010年 | 1007篇 |
2009年 | 920篇 |
2008年 | 1488篇 |
2007年 | 1502篇 |
2006年 | 1403篇 |
2005年 | 1383篇 |
2004年 | 1138篇 |
2003年 | 1076篇 |
2002年 | 1015篇 |
2001年 | 170篇 |
2000年 | 126篇 |
1999年 | 186篇 |
1998年 | 154篇 |
1997年 | 157篇 |
1996年 | 129篇 |
1995年 | 132篇 |
1994年 | 108篇 |
1993年 | 89篇 |
1992年 | 79篇 |
1991年 | 77篇 |
1990年 | 57篇 |
1989年 | 43篇 |
1988年 | 50篇 |
1987年 | 41篇 |
1986年 | 45篇 |
1985年 | 48篇 |
1984年 | 45篇 |
1983年 | 28篇 |
1982年 | 35篇 |
1981年 | 43篇 |
1980年 | 27篇 |
1979年 | 34篇 |
1978年 | 34篇 |
1977年 | 22篇 |
1976年 | 28篇 |
1975年 | 19篇 |
1974年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Hamilton R. Correia Sandra C. Balseiro Elisabete R. Correia Paulo G. Mota Manuel L. De Areia 《American journal of human biology》2004,16(1):24-30
The plumpness of the human newborn has long been recognized as a trait in need of explanation among researchers. Using a linear regression analysis, we find that head circumference is significantly and positively associated with BMI at birth, after gestational age and birthlength were controlled for, in a sample of 1,069 healthy liveborn routinely delivered at the University Hospital of Coimbra (partial correlation r = 0.409, P < 0.0001). This significant association is consistent with the idea that newborn fatness is related to the higher need of lipids in newborn humans as an energetic and plastic substrate during its accelerated brain growth period. As birthweight and birth head size are associated with head size and cognitive abilities in childhood and adult life, it could be postulated that these cognitive abilities could have acted as selective pressure responsible for the newborn fatness increase in our lineage. Am. J. Hum. Biol. 16:24–30, 2004. © 2003 Wiley‐Liss, Inc. 相似文献
72.
Gianluca Taccagni Clara Sambade Jahn Nesland Maria Rosa Terreni Manuel Sobrinho-Simões 《Virchows Archiv : an international journal of pathology》1993,422(6):491-497
We describe three cases of solitary fibrous tumour (SFT) arising from thyroid stroma. Grossly, the tumours were clearly delimited but only partly encapsulated. The following histomorphological growth patterns were observed: bundles of cells in storiform configuration; non-structured bundles; prevalence of fibrous matrix; highly cellular, non-structured; prevalence of loose, non-structured extracellular substance; cellular proliferation and vascular spaces in a haemangiopericytic configuration and a lipomatous component. Immunohistochemical investigation demonstrated intense, diffuse vimentin positivity and focal, less intense actin positivity in all three cases. At electron microscopy we observed a primitive cell of mesenchymal type, with cytoplasm poor in organelles and rich in filaments; this cell sometimes presented differentiation characteristics. SFT is at present the most correct term for the lesions presented here despite some morphological characteristics which differ from cases reported in the literature. 相似文献
73.
Cano J Berzosa PJ Roche J Rubio JM Moyano E Guerra-Neira A Brochero H Mico M Edú M Benito A 《Journal of medical entomology》2004,41(2):158-161
The current study was performed on the Bioko Island (Equatorial Guinea) with the aim of establishing a rapid assessment technique for mapping malaria risk and measuring vector densities. Human bait collection, tent traps, light traps, indoor resting collection, and window exit traps were used to collect Anopheles gambiae s.s. and Anopheles funestus, the two anopheline species involved in malaria transmission in this island. Capture data were used to compare differences in the behavior and vectorial capacity of An. gambiae s.s. and An. funestus. Differences in the two species of mosquitoes were found in relation to the season and trapping methods used. Entomological inoculation rates (EIR) for Plasmodium falciparum were calculated using a polymerase chain reaction (PCR) test with individual anopheline mosquitoes from human bait collections in two villages during the dry and rainy seasons. P. falciparum sporozoites were detected from both dissected heads/thorax and abdomens of both species. 相似文献
74.
75.
Ramos-Casals M García-Carrasco M Brito Zerón MP Cervera R Font J 《Autoimmunity reviews》2002,1(4):238-243
Patients with hepatitis C virus (HCV) chronic infection present some extrahepatic manifestations that may mimic the clinical, immunologic and histological manifestations of primary Sj?gren's syndrome (SS). Thus, HCV patients with sicca symptomatology and positive autoantibodies could be misdiagnosed as a 'primary' SS. Nevertheless, there are several clinical and immunologic features that could help us differentiate both processes. 相似文献
76.
Cloning and analysis of the murine Fanconi anemia group C cDNA 总被引:7,自引:1,他引:7
Fanconi anemia (FA) is one of a group of disorders characterizedat the cellular level by a combination of hypersensitivity toDNA-damaging agents, chromosomal instability, and defectiveDNA repair. Clinical features of FA include pancytopenia, oftenaccompanied by specific congenital malformations, and a predispositionto leukemia. Since the hematological manifestations are thecritical defect in terms of prognosis, FA is a candidate diseasefor gene replacement therapy, and the development of a mousemodel system is essential for the initial stages of this work.Previously, we have cloned the gene defective in FA group Cby complementation of the intrinsic sensitivity of FA cellsto DNA cross-linking agents. We have now cloned the murine homologueof the human FACC cDNA. The mouse cDNA (Facc) shares 79% aminoacid sequence similarity with the human gene product. The expressionof the mouse cDNA in human FA(C) cells restores the cellulardrug sensitivity to normal levels. Thus, the function of theprotein has been conserved despite the significant sequencedivergence. PCR analysis of mouse tissue RNA reveals that thegene is expressed in all adult tissues, while in situ RNA hybridizationexperiments show tissue specific expression at late stages offetal development. Cross-hybridizing sequences exist in DNAfrom other mammals, chicken and Drosophila. These results supportthe hypothesis that the FACC gene product has a role in a basicaspect of cellular protection against DNA damaging agents andthat this function has been conserved during evolution. 相似文献
77.
78.
Danile Reyx Jos Manuel Natrio Martins Irne Campistron Patrick Noireaux 《Macromolecular chemistry and physics.》1993,194(1):87-100
Low-molecular-weight organosilane polymers were prepared by sodium coupling of dichloro-methylphenylsilane ( 1 ) with chlorotrimethylsilane ( 2 ). Gel permeation chromatography (GPC), IR and NMR (1H, 13C and 29Si) analysis of the crude product ( 3 ) were performed and compared with those of the isolated first oligomers, trisilane ( 3a ) and tetrasilane ( 3b ). The GPC characteristics, especially high resolution ones, in accordance with the α,ω-bis(trimethylsilyl)-oligo(methylphenylsilane) structure are compared with those of hydrocarbon polymers. The relations of the NMR characteristics of the methylphenylsilanediyl unit with the position along the chain and the configuration of the diads are approached. Some spectroscopic indications of the secondary structure are discussed. 相似文献
79.
Souriau J Gimenes M Blouin C Benbrik I Benbrik E Churakowskyi A Churakowskyi B 《American journal of medical genetics. Part A》2005,135(3):278-281
Kabuki syndrome (KS) is associated with multiple organ system involvement. Characteristic features include long palpebral fissures with everted lower lids, prominent ears, skeletal abnormalities, mental retardation, and short stature. An increased incidence of infection has been reported in KS, and a few patients have been noted to have immune defects. However, the frequency and severity of the immune deficiency has not been clearly defined. Immunologic evaluation of 19 consecutive individuals with KS was performed at The Children's Hospital of Philadelphia. Decreased IgA levels were noted in 15/19 individuals (79%), 2 of whom had undetectable levels. Eight patients (42%) also had low total IgG levels. Specific IgG subclass abnormalities were found in 6 of 13 patients evaluated. IgM levels were less frequently decreased. One patient failed to generate anti-tetanus antibodies despite immunization. This study suggests that hypogammaglobulinemia is a frequent finding in children with KS. The pattern of antibody abnormalities seen in children with KS resembles common variable immune deficiency (CVID). Due to this increased susceptibility to infection, children with KS should have immunologic evaluations at the time of diagnosis in order to reduce preventable morbidity and mortality. 相似文献
80.
Anthony J McGoron Michael Capille Michael F Georgiou Pablo Sanchez Juan Solano Manuel Gonzalez-Brito John W Kuluz 《BMC medical imaging》2008,8(1):4