全文获取类型
收费全文 | 3235篇 |
免费 | 205篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 128篇 |
妇产科学 | 52篇 |
基础医学 | 377篇 |
口腔科学 | 269篇 |
临床医学 | 275篇 |
内科学 | 678篇 |
皮肤病学 | 20篇 |
神经病学 | 266篇 |
特种医学 | 102篇 |
外科学 | 490篇 |
综合类 | 24篇 |
一般理论 | 1篇 |
预防医学 | 373篇 |
眼科学 | 30篇 |
药学 | 242篇 |
中国医学 | 1篇 |
肿瘤学 | 99篇 |
出版年
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 44篇 |
2020年 | 38篇 |
2019年 | 48篇 |
2018年 | 53篇 |
2017年 | 46篇 |
2016年 | 51篇 |
2015年 | 47篇 |
2014年 | 77篇 |
2013年 | 160篇 |
2012年 | 171篇 |
2011年 | 188篇 |
2010年 | 101篇 |
2009年 | 93篇 |
2008年 | 206篇 |
2007年 | 215篇 |
2006年 | 199篇 |
2005年 | 220篇 |
2004年 | 215篇 |
2003年 | 221篇 |
2002年 | 203篇 |
2001年 | 64篇 |
2000年 | 50篇 |
1999年 | 79篇 |
1998年 | 54篇 |
1997年 | 59篇 |
1996年 | 45篇 |
1995年 | 27篇 |
1994年 | 34篇 |
1993年 | 42篇 |
1992年 | 41篇 |
1991年 | 41篇 |
1990年 | 25篇 |
1989年 | 17篇 |
1988年 | 21篇 |
1987年 | 24篇 |
1986年 | 16篇 |
1985年 | 22篇 |
1984年 | 20篇 |
1983年 | 15篇 |
1982年 | 25篇 |
1981年 | 26篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1978年 | 15篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 6篇 |
排序方式: 共有3461条查询结果,搜索用时 46 毫秒
31.
Use of AffiProbe HPV test kit for detection of human papillomavirus DNA in genital scrapes. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M Ranki A W Leinonen T Jalava P Nieminen V R Soares J Paavonen A Kallio 《Journal of clinical microbiology》1990,28(9):2076-2081
The presence of human papillomavirus (HPV) DNA in cervical and vaginal scrapes was analyzed by the AffiProbe HPV test kit (Orion Corp., Orion Pharmaceutica, Helsinki, Finland), which is a 1-day solution hybridization test for HPV type 6/11, 16, or 18. The AffiProbe test was compared with a commercially available dot blot test (ViraPap and ViraType tests; Life Technologies Inc., Gaithersburg, Md.). The study group consisted of 178 patients seen in a gynecological outpatient clinic. Altogether, 64 specimens (36 cervical and 28 vaginal scrapes) from 49 patients were positive by the AffiProbe test. Concurrently collected cervical scrapes from 174 patients were available for the reference test, which yielded 27 positive results for HPV type 6/11 or 16/18 and 25 positive results for HPV type 31/33/35. Agreement as to the presence of HPV type 6/11, 16, or 18 by the two tests was reached in 85% of the specimens. Eleven cervical specimens were positive by the AffiProbe test only, and nine cervical specimens were positive by the ViraType test only. Independent evidence obtained by the polymerase chain reaction, repeat examination, or the concurrent presence of HPV DNA in vaginal or vulval epithelium supported the AffiProbe and the ViraType test results for 6 of the 11 and 6 of the 9 specimens with discrepant results, respectively. Thus, the DNA tests had similar sensitivities for HPV type 6/11, 16, and 18 DNAs, but the results were obtained within 1 day by the AffiProbe test, whereas results for the ViraPap and ViraType analyses required from 4 days to 2 weeks. 相似文献
32.
Sanna Toppila Jouni Lauronen Pirkko Mattila Juha Pekka Turunen Leena Penttil Timo Paavonen Ossi Renkonen Risto Renkonen 《European journal of immunology》1997,27(6):1360-1365
Lymphocyte homing is initiated by their tethering to and rolling on the high endothelium and is followed by extravasation into the lymph nodes. We show here that glycosylated cell adhesion molecule-1 (GlyCAM-1), CD34, and sialyl Lewis x (sLex) are present on rat lymph node high endothelium analyzed by using monoclonal antibodies. α(1,3)fucosyltransferase VII (Fuc-TVII), the last enzyme involved in the synthesis of the sLex sequence is also expressed on the rat lymph node high endothelium. We have synthesized a family of sLex-decorated oligosaccharide structures and used them to inhibit lymphocyte binding to high endothelium in the Stamper-Woodruff assay. Monovalent sLex, branched di- and tetravalent sLex, as well as a linear tetravalent sLex significantly reduce lymphocyte binding to endothelium. The branched and linear forms of tetravalent sLex were clearly superior inhibitors of the L-selectin-dependent lymphocyte adhesion, with IC50 values in low nanomolar range. In contrast, the fucose-free analogs having the same charge and approximately the same size as the corresponding sLex glycans had no effect on lymphocyte binding and served as negative controls. Taken together, these data show the crucial importance of sLex in the endothelial ligands for L-selectin. Furthermore, we suggest that L-selectin acts as an oligomer on the lymphocyte surface as it binds multivalent sLex glycans. 相似文献
33.
Chlamydia pneumoniae inhibits apoptosis in human epithelial and monocyte cell lines 总被引:12,自引:0,他引:12
Airenne S Surcel HM Tuukkanen J Leinonen M Saikku P 《Scandinavian journal of immunology》2002,55(4):390-398
Chlamydia pneumoniae is an obligate intracellular pathogen with a tendency to cause persistent infections that has been associated with many chronic conditions such as asthma and coronary artery disease. However, its immunopathogenic mechanisms are poorly understood. When aiming to study the impact of C. pneumoniae infection on host cell apoptosis, we found that epithelial infected (HL) cells and macrophages (U937-line) were resistant to staurosporine and tumour necrosis factor (TNF)-alpha-induced physiological apoptosis 48, 72 or 120 h post-infection, as determined by flow cytometry, DNA fragmentation assay and fluorescence microscopy. The antiapoptotic influence was observed even at a late stage of the chlamydial life cycle and was dependent on the chlamydial protein synthesis. The mechanisms involved blockage of mitochondrial cytochrome c release and caspase 3 activation. We also found that during a persistent C. pneumoniae infection induced in vitro by penicillin treatment of cell cultures, the inhibition of apoptosis was extended for up to 120 h of follow-up post-infection and was restricted to the cells carrying chlamydial inclusions. Our findings suggest that inhibition of apoptosis may be one of the pathogenetic mechanisms by which C. pneumoniae infection can mediate the development of chronic diseases. 相似文献
34.
Autoimmune polyendocrinopathy – candidosis – ectodermal dystrophy (APECED): autosomal recessive inheritance 总被引:9,自引:0,他引:9
A genetic analysis was made of 58 patients and their 42 families with APECED (autoimmune polyendocrinopathy--candidosis--ectodermal dystrophy). APECED is characterized by hypoparathyroidism, primary adrenocortical failure and chronic mucocutaneous candidosis, but none of its components is constant. Other endocrine deficiencies can occur as well and also dystrophy of dental enamel and nails. The proportion of affected siblings was 0.147 +/- 0.034 (S.D.) when corrected for truncate single ascertainment, 0.246 +/- 0.019 when corrected for a priori truncate complete ascertainment and 0.240 +/- 0.047 when corrected for a posteriori truncate complete ascertainment. The male/female ratio was 1.04. The results are compatible with autosomal recessive transmission. No heterozygous manifestations of the gene were found. The gene is enriched in isolated subpopulations in central and eastern Finland. APECED is part of the "Finnish heritage of disease". 相似文献
35.
36.
Huang XH Loimaala A Nenonen A Mercuri M Vuori I Pasanen M Oja P Bond G Koivula T Hiltunen TP Nikkari T Lehtimäki T 《Journal of molecular medicine (Berlin, Germany)》1999,77(12):853-858
The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele has been suggested to be a potent risk factor for coronary artery disease; however, the effect of the ACE gene on carotid atherosclerosis remains controversial. We therefore studied the relationship between the ACE gene I/D polymorphism and carotid artery intima-media thickness (IMT). A random sample of 300 men aged 50-59 years living in southern Finland were selected, and 233 agreed to participate (74%). Data were collected in 219 subjects. Quantitative B-mode ultrasonography was used to measure the maximum near and far wall IMT of right and left common, bifurcation, and internal carotid artery. The mean maximum IMT (overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard sites were assumed to have carotid atherosclerosis. The I/D polymorphism was determined by polymerase chain reaction. Overestimation of the frequency of the DD genotype was eliminated by insertion-specific primer and the inclusion of 5% dimethylsulfoxide. No significant differences were found in carotid wall thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30, 1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively. Similarly, the ACE genotypes and allele frequencies did not differ significantly between the subjects with and those without carotid atherosclerosis. There was no association in the subgroups among only nonsmoking subjects or subjects without chronic medication. The present data indicate that the I/D polymorphism of the ACE gene is not related to carotid IMT and is unlikely to play a major role in carotid atherosclerosis. 相似文献
37.
Honkanen PO Mäkelä PH 《BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy》1999,12(1):19-25
Pneumococcal infections, especially pneumococcal pneumonia and pneumococcal bacteraemia are leading causes of morbidity and mortality among the elderly. The emergence of penicillin-resistant pneumococcal strains together with the growing number of old people have emphasised the need for prevention of pneumococcal infections. Prospective cohort studies with pneumonia as the endpoint have so far left open the question of the rationale of vaccinating the risk groups with pneumococcal vaccine. Pneumococcal vaccine has been proven effective against pneumococcal bacteraemia, but the incidence of that disease and thus its importance to the individuals themselves and to the healthcare system is small. Adverse events associated with pneumococcal vaccine are quite frequent but, especially in the elderly, mild and do not limit its use. Clinicians should keep the pneumococcal vaccine in mind and discuss its use with their patients at increased risk for pneumococcal infection. However, before pneumococcal vaccine can be included in national vaccination programmes, its cost-effectiveness in preventing invasive infections must be assured or definitive evidence obtained of its effectiveness against non-invasive pneumococcal infection. 相似文献
38.
Kontiokari T Renko M Kaijalainen T Kuisma L Leinonen M 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2000,108(11):734-738
It is not known how well nasopharyngeal swab culture represents pneumococcal carriage status. We tested this by comparing swab culture to quantitative culture and quantitative PCR of mucosal tissue in a rat model of pneumococcal carriage. Quantitative culture and quantitative PCR identified significantly more carriers compared to swab culture (differences 15% and 33%, 95% CI 1-28% and 16-47%, p=0.04 and 0.001, respectively). The sensitivity and specificity of swab culture was 75/92% and 63/100% compared to quantitative tissue culture and quantitative PCR, respectively. The quantitative estimates of culture and PCR were very similar (Pearson correlation coefficient 0.79, p<0.001). In conclusion, even a well-controlled swab sampling markedly underestimates pneumococcal carriage rate, and simultaneous use of quantitative culture and PCR increases the number of positive samples by about one third. 相似文献
39.
Kunnas TA Lehtimäki T Karhunen PJ Laaksonen R Janatuinen T Vesalainen R Nuutila P Knuuti J Nikkari ST 《Journal of molecular medicine (Berlin, Germany)》2004,82(12):821-825
Most of the effects of estrogens are mediated by estrogen receptors. Vascular endothelial cells and smooth muscle cells express estrogen receptor (ESR1) in both genders. A long genotype group of a common thymine-adenine (TA) dinucleotide repeat polymorphism in the regulatory region of this gene has previously been related to coronary artery disease. The present study examined whether coronary blood flow is affected by this genotype. A total of 49 healthy men were genotyped by PCR and divided into three groups according to median number of the ESR1 promoter TA repeat (=19), i.e., in the short allele genotype group both alleles were of fewer than 19 repeats whereas in the long allele group both alleles were 19 repeats or more. The intermediate group comprised men who had one short and one long allele. Myocardial blood flow was measured by positron emission tomography using [15O]water, performed at rest and during adenosine stimulation. Men with long alleles had lower adenosine-stimulated coronary flow than those with short alleles and those with one short and one long allelle. Our results suggest that adenosine-stimulated myocardial perfusion is lower in subjects with ESR1 long alleles than the other TA repeat genotypes. 相似文献
40.
Interleukin 1-induced lymphocyte binding to endothelial cells. Role of cAMP as a second messenger 总被引:1,自引:0,他引:1
Risto Renkonen Pirkko Mattila Pekka Häyry Jarkko Ustinov 《European journal of immunology》1990,20(7):1563-1567
Interleukin 1 (IL 1) is a potent protein mediator of inflammation. Among other things it increases the number of lymphocytes adhering to endothelial cell monolayers. We analyzed the signal transduction during IL 1-induced lymphocyte binding. Dibutyryl cyclic AMP, which is a cAMP analog able to penetrate into the cytosol, increased lymphocyte binding to the same extent as IL 1. Direct activation of adenylate cyclase by forskolin enhanced also lymphocyte binding. IL 1 increased the level of cytosolic cAMP in a time- and dose-dependent manner measured with radioimmunoassay. 2',5'-Dideoxyadenosine, which is an inhibitor of adenylate cyclase, decreased both the IL 1-induced lymphocyte binding to endothelial cells and elevation in cytosolic cAMP levels. Lymphocyte binding increased with cytosolic cAMP levels in accordance with elevation of IL 1 concentration. These results suggest that cAMP is essential in signal transduction during IL 1-induced lymphocyte binding to cultured endothelial cell monolayers. 相似文献