全文获取类型
收费全文 | 2793篇 |
免费 | 197篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 143篇 |
妇产科学 | 36篇 |
基础医学 | 422篇 |
口腔科学 | 48篇 |
临床医学 | 279篇 |
内科学 | 636篇 |
皮肤病学 | 37篇 |
神经病学 | 150篇 |
特种医学 | 331篇 |
外科学 | 287篇 |
综合类 | 70篇 |
一般理论 | 5篇 |
预防医学 | 247篇 |
眼科学 | 15篇 |
药学 | 165篇 |
中国医学 | 1篇 |
肿瘤学 | 125篇 |
出版年
2023年 | 10篇 |
2022年 | 16篇 |
2021年 | 33篇 |
2020年 | 22篇 |
2019年 | 28篇 |
2018年 | 38篇 |
2017年 | 22篇 |
2016年 | 36篇 |
2015年 | 44篇 |
2014年 | 65篇 |
2013年 | 89篇 |
2012年 | 104篇 |
2011年 | 108篇 |
2010年 | 76篇 |
2009年 | 65篇 |
2008年 | 92篇 |
2007年 | 101篇 |
2006年 | 106篇 |
2005年 | 88篇 |
2004年 | 105篇 |
2003年 | 91篇 |
2002年 | 74篇 |
2001年 | 73篇 |
2000年 | 69篇 |
1999年 | 69篇 |
1998年 | 116篇 |
1997年 | 93篇 |
1996年 | 96篇 |
1995年 | 69篇 |
1994年 | 66篇 |
1993年 | 74篇 |
1992年 | 60篇 |
1991年 | 49篇 |
1990年 | 52篇 |
1989年 | 78篇 |
1988年 | 54篇 |
1987年 | 74篇 |
1986年 | 50篇 |
1985年 | 61篇 |
1984年 | 60篇 |
1983年 | 39篇 |
1982年 | 45篇 |
1981年 | 33篇 |
1980年 | 33篇 |
1979年 | 20篇 |
1978年 | 26篇 |
1977年 | 20篇 |
1976年 | 24篇 |
1975年 | 22篇 |
1974年 | 10篇 |
排序方式: 共有3007条查询结果,搜索用时 15 毫秒
11.
12.
13.
Dr. David A. Danford Bruce M. McManus Stephen M. Nielsen Michael G. Levine Howard W. Needelman 《Pediatric cardiology》1993,14(4):242-246
Summary Correlative echocardiographic and pathological findings in a thoracopagus with conjoined hearts are reported. One twin had tricuspid atresia with discordant atrioventricular connections and concordant ventriculoarterial connections. The morphologic right ventricle was hypoplastic and there was a large muscular ventricular septal defect. The other twin had hypoplasia of the mitral valve anulus and left ventricle with double-outlet right ventricle and pulmonary valve atresia. The tricuspid valve was severely insufficient in part because of a large orifice and redundant, elongated leaflets with abnormal chordal attachments. The left ventricles of these two twins shared a perforated common free wall with at least two large defects allowing mixing of the circulations at that level. Not all anatomic details were established conclusively by fetal echocardiography; however, sufficient diagnostic information was obtained to support a decision not to aggressively resuscitate these twins after elective cesarean delivery at 31 weeks' gestation. 相似文献
14.
Frequency of the ATM IVS10-6T→G variant in Australian multiple-case breast cancer families
下载免费PDF全文

15.
Guo RJ; Wang Y; Kaneko E; Wang DY; Arai H; Hanai H; Takenoshita S; Hagiwara K; Harris CC; Sugimura H 《Carcinogenesis》1998,19(9):1539-1544
Mutations in the transforming growth factor beta type II receptor
(TGFbetaRII) gene have been detected in several human cancer types
exhibiting microsatellite instability. Using intron primers previously
reported for examination of the entire coding region of the TGFbetaRII
gene, 29 sporadic gastric cancers were screened with non-radioactive single
strand conformation polymorphism and subsequent DNA sequencing analysis.
Mutations of the TGFbetaRII gene were detected in three out of 29 tumors
(10%). Two cases showed deletions in a polyadenine tract in both alleles
and was positively associated with replication error. One case had an
insertion of GA dinucleotide sequence in one allele. Mutations of the
TGFbetaRII gene were restricted to exon 3 and other coding regions were not
affected. Loss of heterozygosity was detected by analyzing a polymorphic
site in intron 2. Three out of nine (33%) informative cases, which were all
of intestinal type and advanced cases, showed loss of heterozygosity but
neither TGFbetaRII mutation nor replication error was found in these cases.
Immunoreactivity of TGFbetaRII in tumor tissues was reduced to a different
extent in the gastric cancer with genetically abnormal transforming growth
factor. Although the numbers studied are small, homozygous (A)10 deletion
or loss of heterozygosity of TGFbetaRII is involved in tumorigenesis and
progression of at least some part of sporadic gastric cancer.
相似文献
16.
17.
McManus A 《British journal of sports medicine》2000,34(5):342-347
OBJECTIVE: To provide the basis for collecting rugby union injury data using a rigorously validated injury report form. METHODS: Seven stages were used to assess face, content, and criterion validity of the rugby union injury report form. A 22 member panel plus four sporting bodies assessed the form for face validity, and an expert panel assessed it for content and criterion validity. Panel members were consulted until consensus was reached. A yardstick developed by an expert panel using the Delphi technique was used to assess the reliability of the form. An independent panel of 10 viewed a series of five videotaped injuries, three times over a five week period to assess inter-rater and intrarater reliability. The form was then trialed by 40 people in situ during four games. RESULTS: The rugby union injury report form for games and training was developed, and the face, content, and criterion validity successfully assessed. A seven step protocol to create a yardstick was also developed to assist in the validation process. Both inter-rater and intrarater reliability results indicated a 98% agreement. The 40 trialists who completed forms in situ during four games were found to have an inter-rater reliability agreement of 98% for nine injuries. CONCLUSIONS: A measurement instrument for injury data collection in rugby union was successfully developed and validated, providing researchers with a basis for future studies in this area. A procedure to develop future injury data collection instruments in other sports was also developed. 相似文献
18.
John McManus Timothy Hurtado Anthony Pusateri Kevin J. Knoop 《Prehospital emergency care》2013,17(1):67-71
Four cases are presented to illustrate cutaneous burns sustained with the use of zeolite in the treatment of major hemorrhage secondary to combat wounds. Zeolite, a microporous crystalline aluminosilicate granular hemostatic agent, can cause secondary thermal injuries through an exothermic reaction that is likely related to the absorption of free fluid at the hemorrhage site. Understanding of this process may help both military andcivilian EMS personnel avoid or minimize secondary thermal injury while still benefiting from zeolite's hemostatic capabilities. 相似文献
19.
Geoffrey N. Gobert Hong You Malcolm K. Jones Russell McInnes Donald P. McManus 《Molecular and cellular probes》2013,27(1):19-27
The Chinese (SjC) and Philippine (SjP) strains of the blood fluke Schistosoma japonicum have been shown to present clearly different phenotypes in fecundity, pathology, drug sensitivity and immunology. We used microarray based comparative genomic hybridisation (aCGH) to investigate structural differences in the genomes of the two strains and identified seven distinct regions of the S. japonicum genome that present differential aCGH representing either deletion or duplication regions in SjP. Within these regions, genes predicted to be associated with the recognised phenotypic differences were identified and that may provide new insights into the biology and evolution of the two strains, with implications for the epidemiology and control of schistosomiasis japonica in China and the Philippines. 相似文献
20.
D'Andrea RJ; Barry SC; Moretti PA; Jones K; Ellis S; Vadas MA; Goodall GJ 《Blood》1996,87(7):2641-2648
The hypothesis that extracellular truncation of the common receptor subunit for interleukin-3 (IL-3), granulocyte-macrophage colony- stimulating factor, and IL-5 (h beta c) can lead to ligand-independent activation was tested by infecting factor-dependent hematopoietic cell lines with retroviruses encoding truncated forms of h beta c. A truncation, resembling that in v-Mpl, and retaining 45 h beta c-derived extracellular residues, led to constitutive activation in the murine myeloid cell line, FDC-P1. However, infection of cells with retrovirus encoding a more severely truncated receptor, retaining only 7 h beta c- derived extracellular residues, did not confer factor independence on these cells. These experiments show that truncation activates the receptor and define a 37-amino acid segment of h beta c (H395-A431) which contains two motifs conserved throughout the cytokine receptor superfamily (consensus Y/H XX R/Q VR and WSXWS), as essential for factor-independent signaling. The mechanism of activation was also investigated in less severe truncations. A receptor that retains the entire membrane-proximal domain (domain 4) also conferred factor independent growth on FDC-P1 cells; however, a retrovirus encoding a truncated form of h beta c having two intact membrane proximal domains did not have this ability, suggesting that domain 3 may have an inhibitory role in h beta c. The ability of these receptors to confer factor independence was cell specific as demonstrated by their inability to confer factor-independent growth when introduced into the murine IL-3-dependent pro-B cell line BaF-B03. These results are consistent with a model in which activation requires unmasking of an interactive receptor surface in domain 4 and association with a myeloid- specific receptor or accessory component. We suggest that in the absence of ligand intramolecular interactions prevent inappropriate signaling. 相似文献