全文获取类型
收费全文 | 481篇 |
免费 | 64篇 |
国内免费 | 3篇 |
专业分类
儿科学 | 38篇 |
妇产科学 | 2篇 |
基础医学 | 103篇 |
口腔科学 | 19篇 |
临床医学 | 55篇 |
内科学 | 86篇 |
皮肤病学 | 6篇 |
神经病学 | 4篇 |
特种医学 | 52篇 |
外科学 | 29篇 |
综合类 | 8篇 |
预防医学 | 24篇 |
眼科学 | 57篇 |
药学 | 35篇 |
肿瘤学 | 30篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 6篇 |
2015年 | 12篇 |
2014年 | 20篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 5篇 |
2010年 | 11篇 |
2009年 | 21篇 |
2008年 | 13篇 |
2007年 | 7篇 |
2006年 | 20篇 |
2005年 | 22篇 |
2004年 | 11篇 |
2003年 | 29篇 |
2002年 | 17篇 |
2001年 | 23篇 |
2000年 | 15篇 |
1999年 | 15篇 |
1998年 | 27篇 |
1997年 | 35篇 |
1996年 | 29篇 |
1995年 | 16篇 |
1994年 | 27篇 |
1993年 | 14篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有548条查询结果,搜索用时 15 毫秒
1.
2.
3.
Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand
PA Crock JD McKenzie AM Nicoll NJ Howard W Cutfield LK Shield G Byrne 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(4):381-386
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1 ), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1 ) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis. 相似文献
4.
5.
6.
7.
Multiple clones within multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104. The Greek Nontyphoidal Salmonella Study Group 下载免费PDF全文
Markogiannakis A Tassios PT Lambiri M Ward LR Kourea-Kremastinou J Legakis NJ Vatopoulos AC 《Journal of clinical microbiology》2000,38(3):1269-1271
Six distinct clones were present among Greek multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104, since isolates belonging to resistance phenotypes including the ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) core could be distinguished with respect to their pulsed-field gel electrophoresis patterns, int1 integron structures, and presence or absence of antibiotic resistance genes ant(3')-Ia, pse-1, and tem-1. 相似文献
8.
Sporadic Emergence of Klebsiella pneumoniae Strains Resistant to Cefepime and Cefpirome in Greek Hospitals 总被引:2,自引:0,他引:2 下载免费PDF全文
L. S. Tzouvelekis E. Tzelepi E. Prinarakis M. Gazouli A. Katrahoura P. Giakkoupi O. Paniara N. J. Legakis 《Journal of clinical microbiology》1998,36(1):266-268
The sporadic emergence of Klebsiella pneumoniae strains resistant to cefepime and cefpirome was observed in Greek hospitals during 1996. Examination of six epidemiologically distinct strains and clones selected in vitro provided indications that resistance is due to the cooperation of decreased outer membrane permeability and hydrolysis of the cephalosporins by SHV-5 β-lactamase, which was produced in large amounts. 相似文献
9.
Giakkoupi P Xanthaki A Kanelopoulou M Vlahaki A Miriagou V Kontou S Papafraggas E Malamou-Lada H Tzouvelekis LS Legakis NJ Vatopoulos AC 《Journal of clinical microbiology》2003,41(8):3893-3896
Seventeen Klebsiella pneumoniae clinical isolates carrying the bla(VIM-1) metallo-beta-lactamase gene were collected in the intensive care units of three hospitals in Athens, Greece, in 2002. They exhibited various carbapenem resistance levels (Etest MICs of imipenem ranged from 4 to 32 microg/ml). All isolates gave positive results by the imipenem-EDTA synergy Etest. The isolates were classified into four main types by pulsed-field gel electrophoresis; the majority of the isolates (5 and 10 isolates) belonged to two types. The bla(VIM-1) gene cassette was part of the variable region of a class 1 integron that also included aac6, dhfrI, and aadA. This structure was carried by transferable plasmids. 相似文献
10.
Assessment of Resolution and Intercenter Reproducibility of Results of Genotyping Staphylococcus aureus by Pulsed-Field Gel Electrophoresis of SmaI Macrorestriction Fragments: a Multicenter Study 下载免费PDF全文
Alex van Belkum Willem van Leeuwen Mary Elizabeth Kaufmann Barry Cookson Fran?oise Forey Jerome Etienne Richard Goering Fred Tenover Christine Steward Frances O’Brien Warren Grubb Panayotis Tassios Nicholas Legakis Anne Morvan Névine El Solh Raf de Ryck Marc Struelens Saara Salmenlinna Jaana Vuopio-Varkila Mirjam Kooistra Adriaan Talens Wolfgang Witte Henri Verbrugh 《Journal of clinical microbiology》1998,36(6):1653-1659
Twenty well-characterized isolates of methicillin-resistant Staphylococcus aureus were used to study the optimal resolution and interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Five identical isolates (one PFGE type), 5 isolates that produced related PFGE subtypes, and 10 isolates with unique PFGE patterns were analyzed blindly in 12 different laboratories by in-house protocols. In several laboratories a standardized PFGE protocol with a commercial kit was applied successfully as well. Eight of the centers correctly identified the genetic homogeneity of the identical isolates by both the in-house and standard protocols. Four of 12 laboratories failed to produce interpretable data by the standardized protocol, due to technical problems (primarily plug preparation). With the five related isolates, five of eight participants identified the same subtype interrelationships with both in-house and standard protocols. However, two participants identified multiple strain types in this group or classified some of the isolates as unrelated isolates rather than as subtypes. The remaining laboratory failed to distinguish differences between some of the related isolates by utilizing both the in-house and standardized protocols. There were large differences in the relative genome lengths of the isolates as calculated on the basis of the gel pictures. By visual inspection, the numbers of restriction fragments and overall banding pattern similarity in the three groups of isolates showed interlaboratory concordance, but centralized computer analysis of data from four laboratories yielded percent similarity values of only 85% for the group of identical isolates. The differences between the data sets obtained with in-house and standardized protocols could be the experimental parameters which differed with respect to the brand of equipment used, imaging software, running time (20 to 48 h), and pulsing conditions. In conclusion, it appears that the standardization of PFGE depends on controlling a variety of experimental intricacies, as is the case with other bacterial typing procedures.The use of electric field pulsing techniques in conjunction with agarose gel electrophoresis for discrimination of large DNA molecules was introduced by Schwarz and Cantor in 1984 (9). During the past decade the methodology has been adapted and improved by various research groups to the point that pulsed-field gel electrophoresis (PFGE) for bacterial strain typing is now utilized with relative ease in a variety of laboratories (1). The combination of contour-clamped homogeneous field electrophoresis and PFGE for the molecular analysis of Staphylococcus aureus has been reported since the late 1980s (7, 19). At present, PFGE is considered to have both the reproducibility and resolving power of a standard technique for the epidemiological typing of bacterial isolates (10, 15).Molecular typing systems can identify different strains within a species, generating data useful for taxonomic or epidemiologic purposes (10, 14). A frequently observed shortcoming of typing systems in general is their lack of reproducibility: most typing systems do not provide a definitive strain identification, which is usually due to the variability of the technique and the lack of large databases containing fragment patterns from a wide variety of organisms to which unknowns can be compared. These problems were recently described in detail for two molecular typing systems. A multicenter study on random amplification of polymorphic DNA for discrimination of S. aureus strains revealed a lack of interlaboratory reproducibility among the banding patterns generated by the participating centers, although the epidemiological interpretation of the data was similar for all the centers involved (16). For PFGE, a similar lack of interlaboratory reproducibility of patterns was observed, although the interpretation of the experimental data also differed per participating center (2). The latter study analyzed 12 different methicillin-resistant S. aureus (MRSA) strains with different techniques optimized in each center and different sources and types of equipment. Since interlaboratory discrepancies with respect to classification of the strains were observed, the study concluded that there is a clear need for standardization of the technique, including the construction of a panel of reference strains to assist the individual researcher in the optimization of the PFGE protocol.The aim of the present study was to compare the fragment patterns of a well-defined collection of MRSA isolates in 12 laboratories using in-house and a standard set of PFGE parameters to determine whether standardization of experimental parameters (DNA preparation and switching protocols) would improve intercenter reproducibility of PFGE analysis. 相似文献