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101.
The use of membrane sequencing batch reactors, operated at HRT of 8, 16 and 24 h, was considered for the treatment of a synthetic petroleum wastewater. Increase in HRT resulted in statistically significant decrease in MLSS. Removal efficiencies higher than 97% were found for the three model hydrocarbon pollutants at all HRTs, with air stripping making a small contribution to overall removal. Particle size distribution (PSD) and microscopic analysis showed reduction in the protozoan populations in the activated sludge with decreasing HRT. PSD analysis also showed a higher proportion of larger and smaller sized particles at the lowest HRT. The rate of membrane fouling was found to increase with decreasing HRT; SMP, especially carbohydrate SMP, and mixed liquor apparent viscosity also showed a pronounced increase with decreasing HRT, whereas the concentration of EPS and its components decreased. FTIR analysis identified organic compounds as the main component of membrane pore fouling. 相似文献
102.
Bacterial biofilms are complex microbial depositions on immersed interfaces that form wherever the environmental conditions sustain microbial growth. Despite their name, biofilms can develop in highly irregular structures. Recently several mathematical concepts have been introduced to model these spatially structured microbial populations. Regardless of the type of model, they all have, even for microbially relatively simple systems, many parameters which generally are known at most approximately. We investigate the effect of uncertainties in model parameters on four morphological and four ecological output parameters using a nonlinear diffusion model for a biofilm in which two species compete for a shared nutrient. To this end we conduct an extensive computer simulation experiment for two different levels of data uncertainty, three different hydrodynamic conditions, and two different scenarios of bulk substrate availability. Our results indicate that input model parameter uncertainties have a much larger effect on ecological than on morphological output parameters. 相似文献
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Nasim Babaknejad Fatemeh Sayehmiri Kourosh Sayehmiri Parya Rahimifar Somaye Bahrami Ali Delpesheh Farhad Hemati Sajjad Alizadeh 《Biological trace element research》2014,159(1-3):1-7
Breast cancer is the most common cancer type. In several studies, hints have been provided that there is a correlation between selenium deficiency and the incidence of breast cancer. Findings of these published reports are, however, inconsistent. This study serves as a pioneering study aiming at combining the results of studies using a meta-analytic method. A total of 16 articles published between 1980 and 2012 worldwide were selected through searching PubMed, Scopus, and Google scholar databases, and the information were analyzed using a meta-analytic method [random effects model]. I 2 statistics were used to examine heterogeneity. The information was then analyzed by STATA version 12. In this study, due to the non-uniform methods used to measure selenium concentrations, selenium levels were measured in the various subgroups in both case and control groups. There were significant correlations between selenium concentration and breast cancer [P?<?0.05]. Hence, the mean risk differentiating criteria were estimated to be 0.63 [95 % confidence interval [95% CI] 0.93 to 0.32] in serum and toenails. Subgroup analysis showed that the value in toenails was ?0.07 [95% CI ?0.16 to 0.03] and in serum ?1.04 [95% CI 1.71 to ?0.38]. In studies in which selenium concentrations were measured in serum, a significant correlation was observed between selenium concentration and breast cancer. In contrast, in studies in which selenium concentration was measured in toenails, the correlation was not significant. Therefore, the selenium concentration can be used as one predictor for breast cancer. 相似文献
106.
Iltaf Ahmed Kirti Mittal Taimoor I. Sheikh Nasim Vasli Muhammad Arshad Rafiq Anna Mikhailov Mehrnaz Ohadi Huda Mahmood Guy A. Rouleau Attya Bhatti Muhammad Ayub Myriam Srour Peter John John B. Vincent 《Human genetics》2014,133(11):1419-1429
Mirror movements (MRMV) are involuntary movements on one side of the body that mirror voluntary movements on the opposite side. Congenital mirror movement disorder is a rare, typically autosomal-dominant disorder, although it has been suspected that some sporadic cases may be due to recessive inheritance. Using a linkage analysis and a candidate gene approach, two genes have been implicated in congenital MRMV disorder to date: DCC on 18q21.2 (MRMV1), which encodes a netrin receptor, and RAD51 on 15q15.1 (MRMV2), which is involved in the maintenance of genomic integrity. Here, we describe a large consanguineous Pakistani family with 11 cases of congenital MRMV disorder reported across five generations, with autosomal recessive inheritance likely. Sanger sequencing of DCC and RAD51 did not identify a mutation. We then employed microarray genotyping and autozygosity mapping to identify a shared region of homozygosity-by-descent among the affected individuals. We identified a large autozygous region of ~3.3 Mb on chromosome 22q13.1 (Chr22:36605976?39904648). We used Sanger sequencing to exclude several candidate genes within this region, including DMC1 and NPTXR. Whole exome sequencing was employed, and identified a splice site mutation in the dynein axonemal light chain 4 gene, DNAL4. This splice site change leads to skipping of exon 3, and omission of 28 amino acids from DNAL4 protein. Linkage analysis using Simwalk2 gives a maximum Lod score of 6.197 at this locus. Whether or how DNAL4 function may relate to the function of DCC or RAD51 is not known. Also, there is no suggestion of primary ciliary dyskinesis, situs inversus, or defective sperm in affected family members, which might be anticipated given a putative role for DNAL4 in axonemal-based dynein complexes. We suggest that DNAL4 plays a role in the cytoplasmic dynein complex for netrin-1-directed retrograde transport, and in commissural neurons of the corpus callosum in particular. This, in turn, could lead to faulty cross-brain wiring, resulting in MRMV. 相似文献
107.
Nasim Mansoori Jaap Timmers Thierry Desprez Claire L. A. Kamei Dianka C. T. Dees Jean-Paul Vincken Richard G. F. Visser Herman H?fte Samantha Vernhettes Luisa M. Trindade 《PloS one》2014,9(11)
Cellulose is synthesized by the so called rosette protein complex and the catalytic subunits of this complex are the cellulose synthases (CESAs). It is thought that the rosette complexes in the primary and secondary cell walls each contains at least three different non-redundant cellulose synthases. In addition to the CESA proteins, cellulose biosynthesis almost certainly requires the action of other proteins, although few have been identified and little is known about the biochemical role of those that have been identified. One of these proteins is KORRIGAN (KOR1). Mutant analysis of this protein in Arabidopsis thaliana showed altered cellulose content in both the primary and secondary cell wall. KOR1 is thought to be required for cellulose synthesis acting as a cellulase at the plasma membrane–cell wall interface. KOR1 has recently been shown to interact with the primary cellulose synthase rosette complex however direct interaction with that of the secondary cell wall has never been demonstrated. Using various methods, both in vitro and in planta, it was shown that KOR1 interacts specifically with only two of the secondary CESA proteins. The KOR1 protein domain(s) involved in the interaction with the CESA proteins were also identified by analyzing the interaction of truncated forms of KOR1 with CESA proteins. The KOR1 transmembrane domain has shown to be required for the interaction between KOR1 and the different CESAs, as well as for higher oligomer formation of KOR1. 相似文献
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Rashmi Kapoor Sekh Abdul Nasim Bhupinder Dhir Mahmooduzzafar Abdul Mujib 《In vitro cellular & developmental biology. Plant》2012,48(4):411-416
Garlic, an important flavoring agent and a medicinally useful plant, can take up selenium from its immediate surrounding medium and incorporate it at high concentrations into amino acids and phytochemicals. Selenium, supplied as 0.5, 1.0, 2.0, and 4.0?mg?L?1 Na2SeO3 increased the amino acid, protein, proline, and alliin content of in vitro-grown callus, embryo, plantlet, leaf, and root tissues of Allium sativum L. The enhancement was significant at 2 and 4?mg?L?1. Superoxide dismutase, catalase, and glutathione reductase activities increased in all in vitro-grown tissues and organs with increasing selenium concentrations, but enzyme activity was highest with 4?mg?L?1 selenium. 相似文献
110.
Rodriguez-Manzanet R Meyers JH Balasubramanian S Slavik J Kassam N Dardalhon V Greenfield EA Anderson AC Sobel RA Hafler DA Strom TB Kuchroo VK 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(7):4706-4713
TIM (T cell, Ig, mucin) proteins can regulate T cell immune responses. Tim-4 mRNA is not expressed in T cells, but exclusively in APCs. Tim-4 is a ligand for Tim-1 and Tim-4.Ig fusion protein was shown to either inhibit or expand T cells. However, the molecular basis for such opposite effects was not defined. By generating mAbs, we show that expression of Tim-4 protein is restricted to CD11c(+) and CD11b(+) cells and is up-regulated upon activation. We show that Tim-4 specifically phosphorylates Tim-1 and induces T cell expansion by enhancing cell division and reducing apoptosis. Tim-4 also induces the phosphorylation of signaling molecules LAT, Akt, and ERK1/2 in T cells. Tim-4, expressed on APCs, is a costimulatory molecule that promotes T cell expansion and survival by cross-linking Tim-1 on T cells. 相似文献