全文获取类型
收费全文 | 141篇 |
免费 | 16篇 |
专业分类
157篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 12篇 |
2011年 | 11篇 |
2010年 | 4篇 |
2009年 | 11篇 |
2008年 | 9篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 11篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 15 毫秒
101.
Mirja Puolakkainen Airi Palva Ilkka Julkunen Marjut Ranki Pekka Saikku 《FEMS microbiology letters》1988,55(3):353-359
Abstract Culture, enzyme immunoassay (Chlamydiazyme™) and nucleic acid sandwich hybridization were compared in detecting Chlamydia trachomatis in uncomplicated genital tract infections. Urethral and cervical specimens were collected from 100 males and 100 females attending a sexually transmitted disease clinic. Chlamydial culture was performed under optimal conditions (duplicate inoculation within the day specimen was collected, culture in vials, monoclonal antibody staining of inclusions, blind passage for negative samples). Here the sensitivity of culture exceeded that of the rapid methods. The sensitivity of a chlamydial antigen detection method (Chlamydiazyme™) was 68% in male and 86% in female specimens, when compared with culture, and the specificity was 100% and 97%, respectively. Acinetobacter calcoace9icus present in clinical specimens did not interfere with Chlamydiazyme™. The sensitivity of the nucleic acid sandwich hybridization was 53% of that of the culture, and specificity 100%. By comparing the three methods it was apparent that the rapid methods did not reveal chlamydial infections not detectable by culture. Thus, if performed carefully, culture is the most sensitive diagnostic method in acute genital infections due to C. trachomatis . 相似文献
102.
Safety Evaluation of Sous Vide-Processed Products with Respect to Nonproteolytic Clostridium botulinum by Use of Challenge Studies and Predictive Microbiological Models 下载免费PDF全文
Eija Hyyti-Trees Eija Skytt Mirja Mokkila Arvo Kinnunen Miia Lindstrm Liisa Lhteenmki Raija Ahvenainen Hannu Korkeala 《Applied microbiology》2000,66(1):223-229
Sixteen different types of sous vide-processed products were evaluated for safety with respect to nonproteolytic group II Clostridium botulinum by using challenge tests with low (2.0-log-CFU/kg) and high (5.3-log-CFU/kg) inocula and two currently available predictive microbiological models, Food MicroModel (FMM) and Pathogen Modeling Program (PMP). After thermal processing, the products were stored at 4 and 8°C and examined for the presence of botulinal spores and neurotoxin on the sell-by date and 7 days after the sell-by date. Most of the thermal processes were found to be inadequate for eliminating spores, even in low-inoculum samples. Only 2 of the 16 products were found to be negative for botulinal spores and neurotoxin at both sampling times. Two products at the high inoculum level showed toxigenesis during storage at 8°C, one of them at the sell-by date. The predictions generated by both the FMM thermal death model and the FMM and PMP growth models were found to be inconsistent with the observed results in a majority of the challenges. The inaccurate predictions were caused by the limited number and range of the controlling factors in the models. Based on this study, it was concluded that the safety of sous vide products needs to be carefully evaluated product by product. Time-temperature combinations used in thermal treatments should be reevaluated to increase the efficiency of processing, and the use of additional antibotulinal hurdles, such as biopreservatives, should be assessed. 相似文献
103.
104.
105.
John van der Oost Tuomas Haltia Mirja Raitio Matti Saraste 《Journal of bioenergetics and biomembranes》1991,23(2):257-267
Several loci on theParacoccus denitrificans chromosome are involved in the synthesis of cytochromec oxidase. So far three genetic loci have been isolated. One of them contains the structural genes of subunits II and III, as well as two regulatory genes which probably code for oxidase-specific assembly factors. In addition, two distinct genes for subunit I have been cloned, one of which is located adjacent to the cytochromec
550 gene. An alignment of six promoter regions reveals only short common sequences. 相似文献
106.
Mirja Krause Kaisa Ukkonen Tatu Haataja Maria Ruottinen Tuomo Glumoff Antje Neubauer Peter Neubauer Antti Vasala 《Microbial cell factories》2010,9(1):11
Background
Cultivations for recombinant protein production in shake flasks should provide high cell densities, high protein productivity per cell and good protein quality. The methods described in laboratory handbooks often fail to reach these goals due to oxygen depletion, lack of pH control and the necessity to use low induction cell densities. In this article we describe the impact of a novel enzymatically controlled fed-batch cultivation technology on recombinant protein production in Escherichia coli in simple shaken cultures. 相似文献107.
Tsitko I Rahkila R Priha O Ali-Vehmas T Terefework Z Soini H Salkinoja-Salonen MS 《FEMS microbiology letters》2006,262(2):236-243
Automated ribotyping as a tool for identifying of nontuberculous mycobacteria was evaluated. We created a database comprising of riboprints of 60 strains, representing 32 species of nontuberculous mycobacteria. It was shown that combined ribopatterns generated after digestion with EcoRI and PvuII were distinguishable between species of both slow-growing and rapid-growing mycobacteria. The findings were in good agreement with the 16S rRNA gene sequencing results, allowing correct identification of Mycobacterium lentiflavum isolated from clinical specimens and from biofilms growing in public water distribution system. The automated ribotyping was powerful in discriminating between M. lentiflavum and closely related species M. simiae and M. palustre. Mycobacterium lentiflavum strains from drinking water biofilms were resistant to two to four antimycobacterial drugs. The drinking water distribution system may, thus, be a source of nontuberculous mycobacteria resistant to multiple drugs. 相似文献
108.
Prevention of the flowering of a tree,silver birch 总被引:3,自引:1,他引:2
Lemmetyinen Juha Keinonen Kaija Sopanen Tuomas 《Molecular breeding : new strategies in plant improvement》2004,13(3):243-249
Genetic modification of trees presents great advantages but it is hampered by the possible spread of introduced genes to native populations. However, the spread would be prevented if the modified trees would be sterile. We have previously shown that the induction of sterility by the prevention of flowering is possible in tobacco and Arabidopsis by introducing a gene construct composed of the ribonuclease gene BARNASE ligated to the flower-specific promoter of the birch gene BpMADS1. In the present study, we test this gene construct in silver birch (Betula pendula Roth). When this gene construct was introduced into very early-flowering birch clones, 81 kanamycin resistant lines were obtained. In 38 lines, the vegetative development was disturbed, e.g., the leaves were small and the plants were short and bushy or the growth of plants was weak. More importantly, in 7 other lines no male inflorescences formed or they aborted early. If male inflorescences were formed, they did not contain any stamens. The initial growth of these lines was similar to the non-transgenic control lines. Later, however, the growth of the non-flowering lines differed from that of the controls in showing some dichotomic branching and a reduced number of branches. Preliminary results showed that the gene construct can prevent the development of female inflorescences as well. The results show clearly that BpMADS1::BARNASE can prevent the flowering in a tree but the prevention of flowering may cause some side effects. Studies with ordinary birch clones will show whether the side effects are a property of the early flowering clones or all birches. 相似文献
109.
110.
Maria Ruottinen Monika Bollok Martin Kögler Antje Neubauer Mirja Krause Eija-Riitta Hämäläinen Johanna Myllyharju Antti Vasala Peter Neubauer 《BMC biotechnology》2008,8(1):33