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排序方式: 共有114条查询结果,搜索用时 46 毫秒
91.
92.
Ti-salt flocculation of biologically treated sewage effluent (BTSE) was carried out on monthly basis during one year to trace the seasonal variation in the properties of BTSE, Ti-salt flocculated BTSE and titania photocatalysts. Titania photocatalysts were produced from incineration of Ti-salt flocculated sludge at 600 °C. The physio-chemical properties of BTSE, Ti-salt flocculated BTSE and titania photocatalysts were investigated. The photocatalytic activity of titania was examined using different substrates of rhodamine B and humic acid under UV light irradiation. Results indicated that the flocculation performance of Ti-salt was not affected by the seasonal variation of BTSE. BTSE characteristics resulted in marginal effect in titania characterisation and photocatalytic activity. Titania photocatalysts produced from Ti-salt flocculated sludge in different seasons showed constant anatase phase, high BET surface area and high photocatalytic activity. 相似文献
93.
Chung HY Lee HH Kim KI Chung HY Hwang-Bo J Park JH Sunter G Kim JB Shon DH Kim W Chung IS 《Plant cell reports》2011,30(8):1513-1521
We describe the expression and immunogenicity of a recombinant chimeric protein (HAV VP1-Fc) consisting of human hepatitis A virus VP1 and an Fc antibody fragment using a replicating vector based on Beet curly top virus (BCTV) in Agrobacterium-infiltrated Nicotiana benthamiana leaves. Recombinant HAV VP1-Fc was expressed with a molecular mass of approximately 68?kDa. Recombinant HAV VP1-Fc, purified using Protein A Sepharose affinity chromatography, elicited production of specific IgG antibodies in the serum after intraperitoneal immunization. Following vaccination with recombinant HAV VP1-Fc protein, expressions of IFN-γ and IL-4 were increased in splenocytes at the time of sacrifice. Recombinant VP1-Fc from infiltrated tobacco plants can be used as an effective experimental immunogen for research into vaccine development. 相似文献
94.
Zati Sharip Shon S. Schooler Matthew R. Hipsey Richard J. Hobbs 《Biological invasions》2012,14(5):1029-1044
In this study we: (1) present a quantitative spatial analysis of the macrophyte communities in Lake Chini with a focus on
the biogeographical distributions of the native Nelumbo nucifera and the invasive Cabomba furcata; (2) examine the environmental changes that affect plant community composition; and (3) outline a conceptual model of the
variation of ecological processes that shape the macrophyte communities. Plant species cover, biomass of C. furcata and N. nucifera, and water quality and environmental variables were measured before and after monsoonal floods in September 2009 and April
2010. Permutational multivariate analysis was used to examine the significance of the invasion of C. furcata at different spatial scales. Relationships between plant species cover and environmental variables before and after flooding
were examined using principal coordinates analysis and non-parametric multivariate multiple regressions. Our findings suggest
that (1) Variation in plant communities was significant at the lake scale and the distribution of plant species changed after
annual floods. (2) Invasion by C. furcata significantly affected the overall plant community composition. (3) C. furcata biomass increased after the monsoonal season, which indicates that C. furcata is adapted to flooding events and that it is becoming increasingly abundant. (4) In addition to the strong monsoonal effect,
total depth, nutrient concentration, and sediment type were important environmental variables that significantly affected
plant community composition. The macrophyte community in Lake Chini is highly dynamic. The spatial and temporal plant community
dynamics are associated with flood regime, water quality, and substrate. Human-induced changes in these parameters are likely
shifting the macrophyte dominance from floating-leaved to submerged species. 相似文献
95.
Soo-Kyung Shon Ji Young Kim 《Biochemical and biophysical research communications》2009,385(2):198-203
In the current study, we examined the function of N-myc downstream-regulated gene 2 (NDRG2) expression in breast cancer cells, especially focusing on the role of bone morphogenetic protein-4 (BMP-4) induced by NDRG2. NDRG2 expression in MDA-MB-231 cells inhibited the mRNA expression of several matrix metalloproteinases (MMPs) and the gelatinolytic activity of MMP-9. Interestingly, a specific induction of active BMP-4 was exclusively observed in MDA-MB-231-NDRG2 cells but not in MDA-MB-231-mock cells. Neutralization of BMP-4 in MDA-MB-231-NDRG2 cells resulted in the rescue of MMP-9 mRNA expression and migration capacity. In addition, treatment with recombinant BMP-4 dramatically suppressed MMP-9 mRNA expression, gelatinolytic MMP-9 activity, migration, and invasion capacity both in MDA-MB-231 and PMA-treated MCF-7 cells. Collectively, our data show that BMP-4 induced by NDRG2 expression inhibits the metastatic potential of breast cancer cells, especially via suppression of MMP-9 activity. 相似文献
96.
Mark E. Polhemus Shon A. Remich Bernhards R. Ogutu John N. Waitumbi Lucas Otieno Stella Apollo James F. Cummings Kent E. Kester Christian F. Ockenhouse Ann Stewart Opokua Ofori-Anyinam Isabelle Ramboer Conor P. Cahill Marc Lievens Marie-Claude Dubois Marie-Ange Demoitie Amanda Leach Joe Cohen W. Ripley Ballou D. Gray Heppner Jr. 《PloS one》2009,4(7)
Background
This study advances the clinical development of the RTS,S/AS01B candidate malaria vaccine to malaria endemic populations. As a primary objective it compares the safety and reactogenicity of RTS,S/AS01B to the more extensively evaluated RTS,S/AS02A vaccine.Methodology
A Phase IIb, single centre, double-blind, controlled trial of 6 months duration with a subsequent 6 month single-blind follow-up conducted in Kisumu West District, Kenya between August 2005 and August 2006. 255 healthy adults aged 18 to 35 years were randomized (1∶1∶1) to receive 3 doses of RTS,S/AS02A, RTS,S/AS01B or rabies vaccine (Rabipur®; Chiron Behring GmbH) at months 0, 1, 2. The primary objective was the occurrence of severe (grade 3) solicited or unsolicited general (i.e. systemic) adverse events (AEs) during 7 days follow up after each vaccination.Principal Findings
Both candidate vaccines had a good safety profile and were well tolerated. One grade 3 systemic AE occurred within 7 days of vaccination (RTS,S/AS01B group). No unsolicited AEs or SAEs were related to vaccine. A marked increase in anti-CS antibody GMTs was observed post Dose 2 of both RTS,S/AS01B (31.6 EU/mL [95% CI: 23.9 to 41.6]) and RTS,S/AS02A (16.7 EU/mL [95% CI: 12.9 to 21.7]). A further increase was observed post Dose 3 in both the RTS,S/AS01B (41.4 EU/mL [95% CI: 31.7 to 54.2]) and RTS,S/AS02A (21.4 EU/mL [95% CI: 16.0 to 28.7]) groups. Anti-CS antibody GMTs were significantly greater with RTS,S/AS01B compared to RTS,S/AS02A at all time points post Dose 2 and Dose 3. Both candidate vaccines produced strong anti-HBs responses. Vaccine efficacy in the RTS,S/AS01B group was 29.5% (95% CI: −15.4 to 56.9, p = 0.164) and in the RTS,S/AS02A group 31.7% (95% CI: −11.6 to 58.2, p = 0.128).Conclusions
Both candidate malaria vaccines were well tolerated over a 12 month surveillance period. A more favorable immunogenicity profile was observed with RTS,S/AS01B than with RTS,S/AS02A.Trial Registration
Clinicaltrials.gov NCT00197054相似文献97.
Tsun-Shih Hsieh A. B. Schooler Allyn Bell John D. Nalewaja 《American journal of botany》1972,59(8):789-796
All hybrid plants from interspecific crosses among the three species, Sonchus asper (L.) Hill, S. oleraceus L., and S. arvensis L., were male-sterile, but the progeny of the cross S. arvensis X S. oleraceus and reciprocal cross produced seed after backcrossing to the male parent. Hybrid plants from crosses between S. oleraceus and S. asper lacked vigor. Cytological data indicated that S. arvensis has one genome in common with S. asper and that S. oleraceus is an autotetraploid (2n = 36) with no genomes in common with S. arvensis or S. asper. 相似文献
98.
Ives AR Schooler SS Jagar VJ Knuteson SE Grbic M Settle WH 《The American naturalist》1999,154(6):652-673
When a parasitoid is searching for hosts, not all hosts are equally likely to be attacked. This variability in attack probability may affect the parasitoid functional response. Using a collection of experiments, we quantified the functional response of Aphidius ervi (Hymenoptera: Braconidae), an insect parasitoid of the pea aphid Acyrthosiphon pisum (Homoptera: Aphididae). We measured variability in the number of hosts attacked by a foraging parasitoid both among plants and within plants. At the first scale, A. ervi, searching among plants containing different numbers of aphids, showed both aphid-density-dependent and aphid-density-independent variability in the number of aphids attacked per plant. Within plants, A. ervi selectively attacked second and third instar aphids relative to other instars. Furthermore, there was variability in the susceptibility of attack among aphids independent of instar. Variability in attack rates among aphids both among and within plants decreased parasitoid foraging efficiency, with the greatest decrease caused by among-plant variability. Furthermore, the decrease in foraging efficiency was greatest when the average number of aphids per plant was low, thereby transforming a strong Type II functional response into one approaching Type I. 相似文献
99.
In the course of a study of the microbial degradation of polychlorinated biphenyls (PCB), 16 cultures, representing 5 genera of bacteria, were isolated. APseudomonas sp. was found to degrade mixtures of PCB (Aroclor 1254) and pure isomers, i.e., hexachlorobiphenyl (HCB). Degradation was found to be variable, depending on length of incubation, purity, and degree of chlorination of the biphenyl molecule. In addition to apparent degradation of PCB, it was observed that PCB stimulated growth and oxygen uptake. Bioaccumulation of PCB residues was suggested since14-Clabeled material derived from14C-PCB accumulated on or in the bacterial cells. The potential degradation and utilization of PCB by microorganisms suggests that this may be an important mechanism for removal or mobilization of PCB into food chains in the estuarine environment. 相似文献
100.
Rahman A Kumar SG Kim SW Hwang HJ Baek YM Lee SH Hwang HS Shon YH Nam KS Yun JW 《Proteomics》2008,8(3):569-581
In the present study, we performed a differential proteomic analysis using 2-DE combined with MS to clarify the molecular mechanism for the suppressive effect of chitosan oligosaccharides (CO) during differentiation of adipocyte 3T3-L1. Cell differentiation was significantly inhibited by CO at the concentration of 4 mg/mL. Protein mapping of adipocyte homogenates by 2-DE revealed that numerous protein spots were differentially altered in response to CO treatment. Out of 50 identified proteins showing significant alterations, six were up-regulated and 44 were down-regulated by CO treatment in comparison to control mature adipocytes. Among them, most of the proteins are associated with lipid metabolism, cytoskeleton, and redox regulation, in which the levels of farnesyl diphosphate synthetase (FDS), dedicator of cytokinesis 9 (DOCK9), and chloride intracellular channel 1 (CLIC1) were significantly reduced (>two-fold) with CO treatment. These results have not previously been examined in the context of adipogenesis, and thus can be used as novel biomarkers. Taken together with immunoblot analysis, it was concluded that the inhibitory effect of CO on adipocyte differentiation was mediated by C/EBPalpha and PPARgamma pathway through significant downregulations of important adipogenic molecules such as fatty acid binding protein and glucose transporter 4. 相似文献