排序方式: 共有72条查询结果,搜索用时 15 毫秒
51.
Maryam Salimizadeh Hossein Shariatmadari Mahnaz Nikaeen Seyedeh Leili Mohebi Nozar 《International journal of phytoremediation》2018,20(7):658-665
This study was carried out to assess the dissipation of 17 selected polychlorinated biphenyl (PCBi) congeners in a transformer oil-contaminated soil using bioaugmentation with 2 PCB-degrading bacterial strains, i.e., Pseudomonas spp. S5 and Alcaligenes faecalis, assisted or not by the maize (Zea mays L.) plantation. After 5 and 10 weeks of treatment, the remaining concentrations of the target PCBi congeners in the soil were extracted and measured using GC-MS. Results showed that the bacterial augmentation treatments with Pseudomonas spp. S5 and A. faecalis led to 21.4% and 20.4% reduction in the total concentration of the target PCBs (ΣPCBi), respectively, compared to non-bioaugmented unplanted control soil. The ΣPCBi decreased by 35.8% in the non-bioaugmented planted soil compared with the control. The greatest degradation of the PCB congeners was observed over a 10-week period in the soil inoculated with Pseudomonas spp. S5 and cultivated with maize. Under this treatment, the ΣPCBi decreased from 357 to 119 ng g?1 (66.7% lower) and from 1091 to 520 ng g?1 (52.3% lower). Overall, the results suggested that the combined application of phytoremediation and bioaugmentation was an effective technique to remove PCBs and remediate transformer oil-contaminated soils. 相似文献
52.
Colon and intestinal crypts have been widely chosen to study cell dynamics because of their fairly simple structures. In the colon and intestinal crypts, stem cells (SCs) are located at very bottom of the crypt, fully differentiated cells (FDs) are located in the top of the crypt, and transit-amplifying cells (TAs) are in the middle of the crypt between FDs and SCs. Recently, it has been discovered that there are two types of stem cells in the intestinal crypts: central stem cells (CeSCs) and border stem cells. To investigate dynamics of mutants in colon and intestinal crypts, we develop a four-compartmental stochastic model, which includes two SC compartments, and TAs and FDs compartments. We calculate the probability of the progeny of marked or mutant cells located at each of these compartments taking over the entire crypt or being washed out from the crypt. We found that the progeny of CeSCs will take over the entire crypt with a probability close to one. Interestingly, the progeny of advantageous mutant TAs and FDs will be washed out faster than disadvantageous mutants. Saliently, the model predicts that the time that the progeny of wild-type central stem cells will take over the mouse intestinal crypt is around 60 days, which is in perfect agreement with an experimental observation. 相似文献
53.
Morphological analysis of Brandt's hedgehog (Paraechinus hypomelas) reflects the isolation history of Persian Gulf islands and has implications for taxonomy
下载免费PDF全文
![点击此处可从《Biological journal of the Linnean Society. Linnean Society of London》网站下载免费的PDF全文](/ch/ext_images/free.gif)
54.
Vahidinia Aliasghar Samiee Fateme Faradmal Javad Rahmani Alireza Taravati Javad Masoumeh Leili Mostafa 《Biological trace element research》2019,187(1):32-40
Biological Trace Element Research - Breast milk is considered the best source of nutrition for all infants. However, exposure of newborns to toxic metals is of special interest due to their... 相似文献
55.
Analysis of host-inducing proteome changes in bifidobacterium longum NCC2705 grown in Vivo 总被引:1,自引:0,他引:1
Yuan J Wang B Sun Z Bo X Yuan X He X Zhao H Du X Wang F Jiang Z Zhang L Jia L Wang Y Wei K Wang J Zhang X Sun Y Huang L Zeng M 《Journal of proteome research》2008,7(1):375-385
To investigate the molecular mechanisms underlying the adaptation of Bifidobacterium longum to the intestinal tract, we utilized a new model for rabbit intestinal culture of B. longum and reported the changes in proteomic profiles after incubation in the in vivo environment. By 2D-PAGE coupled with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and/or electrospray ionization tandem mass spectrometry (ESI-MS/MS) analyses, proteomic profiles of B. longum strain NCC2705 grown in the in vivo and in vitro environments were compared. Confirmed by semiquantitative RT-PCR, which exhibited at least a 3-fold change or greater, 19 up-regulated proteins, 14 down-regulated proteins, and 4 proteins with mobility changes were identified during intestinal growth. These identified proteins include key stress proteins, metabolism-related proteins, and proteins related to translation. Our results indicate that some useful proteins are expressed at higher levels in cells during intestinal growth. These proteins reflected the adaptation of B. longum NCC2705 to the intestine, such as EF-Tu which contributes to the retention or attachment as a Bifidobacterium adhesin-like factor, bile salt hydrolase (BSH) which might play an important role in the molecular mechanisms for the initial interaction of probiotic with the intestinal environment, and stress proteins which defend B. longum against the action of bile salts and other harmful ingredients of the gastrointestinal tract (GIT). The most striking fact of our observation was that four proteins GlnA1, PurC, LuxS, and Pgk exhibit clear post-translational modification. Western blot (WB) analysis and Pro-Q Diamond staining revealed that substances of the GIT trigger Pgk and LuxS phosphorylation at Ser/Thr residues for bacteria grown in vivo. These proteins were identified for the first time as bifidobacterial phosphoproteins. Our data suggest that the phosphorylated autoinducer-2 production protein LuxS of B. longum NCC2705 (LuxS-P) is the active form of LuxS and that LuxS-P may play a key role in the regulation of quorum sensing. 相似文献
56.
The sediment stratigraphy of a medium-sized mixotrophic lake (Ruila) situated below the highest shoreline of the Baltic Ice
Lake in the West-Estonian Lowland is described. The lake is without natural inlets our outlets. The reconstruction of vegetation
and land-use history based on pollen data, combined with available archaeological data and detailed 14C dating allows us to give a provisional reconstruction of the temporal and spatial pattern of natural and human induced environmental
changes in north-west Estonia during the Holocene. Both radiocarbon dates derived from terrestrial macrofossil dating by accelerator
mass spectrometry (AMS) and conventional dating of bulk lake sediment are discussed. The isolation of the lake basin from
the Yoldia Sea took place ca. 9700 cal B. C. The Ancylus Lake transgression at ca. 8400 cal B. C. did not reach the basin,
but caused a ground water rise, seen in the sediment stratigraphy of the lake. The first signs of human impact on the pollen
record appear ca. 5400 cal B. C. (Late Mesolithic). The history of arable farming has been divided into three periods: 1)
introduction of crop cultivation and animal husbandry (1500 cal B. C. – A. D. 500); 2) establishment of animal husbandry A.
D. 500–1000) and 3) establishment of crop cultivation and intensive cattle breeding (A. D. 1000–today). Due to unfavourable
eda-phic conditions the introduction of arable farming was delayed for more than 1000 years compared with elsewhere on the
north coast of Esotnia, and intensity of land-use never reached the same proportion as in these areas.
Received August 15, 2001 / Accepted August 5, 2002
Correspondence to: Leili Saarse 相似文献
57.
58.
59.
Jing Xie Shengjie Yi Jiangong Zhu Peng Li Beibei Liang Hao Li Xiaoxia Yang Ligui Wang Rongzhang Hao Leili Jia Zhihao Wu Shaofu Qiu Hongbin Song 《PloS one》2015,10(10)
Salmonella enterica subsp. enterica serovar Choleraesuis is a highly invasive pathogen of swine that frequently causes serious outbreaks, in particular in Asia, and can also cause severe invasive disease in humans. In this study, 21 S. Choleraesuis isolates, detected from 21 patients with diarrhea in China between 2010 and 2011, were found to include 19 H2S-negative S. Choleraesuis isolates and two H2S-positive isolates. This is the first report of H2S-negative S. Choleraesuis isolated from humans. The majority of H2S-negative isolates exhibited high resistance to ampicillin, chloramphenicol, gentamicin, tetracycline, ticarcillin, and trimethoprim-sulfamethoxazole, but only six isolates were resistant to norfloxacin. In contrast, all of the isolates were sensitive to cephalosporins. Fifteen isolates were found to be multidrug resistant. In norfloxacin-resistant isolates, we detected mutations in the gyrA and parC genes and identified two new mutations in the parC gene. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and clustered regularly interspaced short palindromic repeat (CRISPR) analysis were employed to investigate the genetic relatedness of H2S-negative and H2S-positive S. Choleraesuis isolates. PFGE revealed two groups, with all 19 H2S-negative S. Choleraesuis isolates belonging to Group I and H2S-positive isolates belonging to Group II. By MLST analysis, the H2S-negative isolates were all found to belong to ST68 and H2S-positive isolates belong to ST145. By CRISPR analysis, no significant differences in CRISPR 1 were detected; however, one H2S-negative isolate was found to contain three new spacers in CRISPR 2. All 19 H2S-negative isolates also possessed a frame-shift mutation at position 760 of phsA gene compared with H2S-positive isolates, which may be responsible for the H2S-negative phenotype. Moreover, the 19 H2S-negative isolates have similar PFGE patterns and same mutation site in the phsA gene, these results indicated that these H2S-negative isolates may have been prevalent in China. These findings suggested that surveillance should be increased of H2S-negative S. Choleraesuis in China. 相似文献
60.
Claire E. Turner Mary Sommerlad Karen McGregor Frances J. Davies Bruno Pichon Deborah L. W. Chong Leili Farzaneh Matthew T. G. Holden Brian G. Spratt Androulla Efstratiou Shiranee Sriskandan 《PloS one》2012,7(10)
Streptococcus pyogenes M/emm3 strains have been epidemiologically linked with enhanced infection severity and risk of streptococcal toxic shock syndrome (STSS), a syndrome triggered by superantigenic stimulation of T cells. Comparison of S. pyogenes strains causing STSS demonstrated that emm3 strains were surprisingly less mitogenic than other emm-types (emm1, emm12, emm18, emm28, emm87, emm89) both in vitro and in vivo, indicating poor superantigenic activity. We identified a 13 bp deletion in the superantigen smeZ gene of all emm3 strains tested. The deletion led to a premature stop codon in smeZ, and was not present in other major emm-types tested. Expression of a functional non-M3-smeZ gene successfully enhanced mitogenic activity in emm3 S. pyogenes and also restored mitogenic activity to emm1 and emm89 S. pyogenes strains where the smeZ gene had been disrupted. In contrast, the M3-smeZ gene with the 13 bp deletion could not enhance or restore mitogenicity in any of these S. pyogenes strains, confirming that M3-smeZ is non-functional regardless of strain background. The mutation in M3-smeZ reduced the potential for M3 S. pyogenes to induce cytokines in human tonsil, but not during invasive infection of superantigen-sensitive mice. Notwithstanding epidemiological associations with STSS and disease severity, emm3 strains have inherently poor superantigenicity that is explained by a conserved mutation in smeZ. 相似文献