全文获取类型
收费全文 | 198996篇 |
免费 | 23146篇 |
国内免费 | 1256篇 |
专业分类
耳鼻咽喉 | 3140篇 |
儿科学 | 6122篇 |
妇产科学 | 5111篇 |
基础医学 | 14437篇 |
口腔科学 | 6482篇 |
临床医学 | 39557篇 |
内科学 | 40964篇 |
皮肤病学 | 4796篇 |
神经病学 | 20862篇 |
特种医学 | 5364篇 |
外国民族医学 | 33篇 |
外科学 | 25388篇 |
综合类 | 1107篇 |
现状与发展 | 40篇 |
一般理论 | 140篇 |
预防医学 | 25038篇 |
眼科学 | 3275篇 |
药学 | 6212篇 |
3篇 | |
中国医学 | 143篇 |
肿瘤学 | 15184篇 |
出版年
2024年 | 1063篇 |
2023年 | 5816篇 |
2022年 | 2201篇 |
2021年 | 4793篇 |
2020年 | 6754篇 |
2019年 | 4392篇 |
2018年 | 9266篇 |
2017年 | 8990篇 |
2016年 | 9747篇 |
2015年 | 9944篇 |
2014年 | 13088篇 |
2013年 | 16424篇 |
2012年 | 10189篇 |
2011年 | 10306篇 |
2010年 | 10323篇 |
2009年 | 12208篇 |
2008年 | 9250篇 |
2007年 | 8709篇 |
2006年 | 9693篇 |
2005年 | 7999篇 |
2004年 | 7259篇 |
2003年 | 6579篇 |
2002年 | 6060篇 |
2001年 | 2472篇 |
2000年 | 1608篇 |
1999年 | 2296篇 |
1998年 | 3115篇 |
1997年 | 2705篇 |
1996年 | 2649篇 |
1995年 | 2299篇 |
1994年 | 1656篇 |
1993年 | 1476篇 |
1992年 | 1143篇 |
1991年 | 988篇 |
1990年 | 843篇 |
1989年 | 778篇 |
1988年 | 780篇 |
1987年 | 637篇 |
1986年 | 585篇 |
1985年 | 557篇 |
1984年 | 548篇 |
1983年 | 594篇 |
1982年 | 610篇 |
1981年 | 558篇 |
1980年 | 406篇 |
1979年 | 261篇 |
1978年 | 295篇 |
1977年 | 292篇 |
1976年 | 239篇 |
1975年 | 191篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Kun Hwang MD PhD Ei Tae Kim MD Se Il Lee MD DMSc 《The Journal of foot and ankle surgery》2005,44(6):473-477
The purpose of this study was to determine the genetic characteristics of foot polydactyly and identify its inheritance pattern by analyzing familial pedigree. Five cases from 2 Korean families were studied: 1 is a family whose members have been affected for 4 generations and the other for 2 generations. Using peripheral blood samples, we performed chromosomal analysis using the banding technique with Giemsa stain and karyotyping. We investigated the shape and structure of 46 chromosomes, looking for translation, deletion, inversion, ring chromosome, and isochromosome abnormalities. All peripheral blood samples demonstrated no chromosomal abnormalities, though the genetic nature of foot polydactyly and a new genetic locus was identified recently by other studies. Familial pedigree analysis suggested that polydactyly was inherited as an autosomal dominant trait in the first family. The mode of inheritance for the second family could not be determined due to an insufficient number of family members. The result of this study brought us to the conclusion that, while genetic factors play a major role in polydactyly, other factors may contribute to its occurrence. 相似文献
72.
73.
Philip J. Langlais PhD Mark L. Wardlow BS Hitoshi Yamamoto MD 《Pediatric neurology》1991,7(6):440-445
Cerebrospinal fluid (CSF) from 7 patients with infantile spasms (mean age: 6.7 months) was collected before and after treatment with adrenocorticotropic hormone (ACTH). The concentration of neurotransmitter metabolites was analyzed using high-performance liquid chromatography and compared to the metabolite concentration in the CSF from 7 age-matched controls (mean age: 6.1 months). Pretreatment levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid, 3-methoxy-4-hydroxyphenyl glycol (MHPG), and kynurenine were significantly lower in infantile spasm patients compared to controls. Following treatment, marked increases in 5-HIAA and decreases in kynurenine levels were observed in the CSF of the 5 infants whose seizures were eliminated or reduced by ACTH. In the 2 nonresponders 5-HIAA levels decreased. The level of MHPG was reduced slightly in 5 infants, including the 2 nonresponders, and was increased in 2 responders. CSF homovanillic acid levels increased in 4 infantile spasm infants and decreased in 3 following ACTH. These data demonstrate that the presence of seizures in infantile spasms is associated with a significant decrease in serotonergic activity and that elimination of seizures by ACTH is accompanied by increased serotonin turnover. The simultaneous increase of 5-HIAA and decrease of kynurenine, an alternate metabolite of tryptophan, suggests an underlying disturbance of tryptophan metabolism in infantile spasms. The possibility that elimination of seizures by ACTH may be related to decreased production of certain kynurenine metabolites, particularly quinolinic acid, is discussed. 相似文献
74.
Ruben A. Mesa MD Alfonso Quintás-Cardama MD Srdan Verstovsek MD PhD 《Current hematologic malignancy reports》2007,2(1):25-33
Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a classic (ie, BCR-ABL-negative) myeloproliferative
disorder characterized by anemia, multiorgan extramedullary hematopoiesis, constitutional symptoms, and premature death from
either leukemic transformation or other disease complications. Stem cell transplantation can be curative, but many patients
either are not appropriate candidates or do not choose to accept the significant risks associated with transplantation. Current
pharmacologic therapy has been beneficial mainly in terms of palliating disease-associated cytopenias, constitutional symptoms,
splenomegaly, and other organ damage from excess myeloproliferation. Novel treatment strategies are under investigation, including
targeted inhibition of JAK2V617F, the activating tyrosine kinase point mutation present in about half of patients with MMM. In this article, we review both
the old and new pharmacologic options for MMM. 相似文献
75.
Edward J Boland Mary MacDougall David L Carnes Sabine H Dickens 《Dental materials》2006,22(4):338-345
Recently, a resin-based calcium phosphate cement (RCPC) has been reported as a remineralizing pulp-capping or lining cement. RCPC consists mainly of tetracalcium and dicalcium phosphates, ethoxylated bisphenol A dimethacrylate and pyromellitic glycerol dimethacrylate monomers and photo- and chemical initiators. OBJECTIVES: Here, the cytotoxic effects of RCPC were evaluated. The hypothesis was that RCPC induced only minor cytotoxic response in immortalized murine odontoblast and pulp cells, comparable to that produced by similar dimethacrylates due to unpolymerized dimethacrylate monomer present after curing. METHODS: Cytotoxicity was determined following the changes in cell succinate dehydrogenase activity after 24 h exposure to the cement components and after a 24 h recovery period. A fourfold range of concentrations was tested of the monomers, the eluate of cured RCPC leached in Dulbecco's modified Eagle's medium, and crushed cured cement in dimethyl sulfoxide. RESULTS: The monomers themselves had cytotoxicities similar to those reported for other dimethacrylates, although they are significantly less toxic than Bis-GMA. Differential cell sensitivity was demonstrated, with the pulp cells having greater sensitivity to the unpolymerized monomer than the odontoblast-like cells. The leached components have cytotoxicity similar to that of the free monomers. The crushed material demonstrated no apparent cytotoxicity at the dilutions tested. SIGNIFICANCE: These data demonstrate that RCPC has an in vitro cytotoxicity that is comparable to other materials containing dimethacrylate monomers and suggest that the material may be suitable for use in dental restorations. The data also indicate that the pulp cells appear more sensitive to dimethacrylates than the odontoblasts. 相似文献
76.
77.
78.
Boris A. Zelle MD Andrea S. Herzka MD Christopher D. Harner MD James J. Irrgang PhD PT ATC 《Operative Techniques in Orthopaedics》2005,15(1):76
Clinical outcomes data can be used to facilitate patient management decisions, assess clinician and organizational performance, and to provide evidence for the effectiveness of surgery and rehabilitation. The validity of the inferences made from outcomes data are dependent on the validity of the outcomes measures themselves and the circumstances under which the data were collected, analyzed, and interpreted. Clinical outcomes may include measures of impairment of body structure and function, activity limitation, and participation restriction. However, because the relationship between impairment and the resulting activity limitation and participation restriction is not direct, and because activity limitations and participation restrictions are of the utmost concern to the athlete, the primary clinical outcome should be measures of activity limitation and participation restriction. Activity limitation and participation restriction may be measured either through direct observation of performance or by general or specific measures of health related quality of life. Clinical outcomes data must be collected systematically to ensure valid inferences from the data. 相似文献
79.
80.