FAHP ranking and selection of pretreatment module for membrane separation processes in textile cluster

Recent development in membrane manufacturing and extensive application of membranes in effluent treatment has opened up a new water resource. The effluent pretreatment module plays a critical role in membrane performance. Appropriate selection of conventional and advanced pretreatment modules in membrane separation processes (MSP) is significant to the success of zero effluent discharge (ZED). This study addresses performance assessment of eight conventional and advanced pretreatment modules implemented for wastewater management in a textile cluster in South India. The comparative pollutant reduction, capital, operation and maintenance (OM) cost of pretreatment modules are discussed. The ranking and interdependence of the pretreatment modules were analyzed through fuzzy analytical hierarchy process (FAHP) with MATLAB software.The pretreatment module IV ranked third with a composite weight of 15.46%. The integrated study of performance assessment and FAHP resulted in an optimum pretreatment module IV comprising the sequence of chemical precipitation, bio-oxidation processes (activated sludge processes) followed by chemical precipitation, to achieve the ZED. This study provides a techno-economically feasible solution for selection of an effective pretreatment module for MSP in the textile cluster.     

伴HBV感染性肝癌调控枢纽基因筛选与初步鉴定

慢性乙型肝炎病毒(Hepatitis B virus,HBV)感染引起的原发性肝癌涉及多种基因、转录本和蛋白质的相互作用及调控。从单个基因的角度来看,某个基因的表达量的改变只能对肝癌发生发展的局部作出解释而无法从整体行为进行深入和全面的探索,无法满足高度复杂性的调控研究需要。筛选乙肝相关性肝癌的基因芯片数据获取差异表达基因后,应用加权基因共表达网络分析算法构建基因共表达网络,识别与肝癌发生相关的模块,利用可视化筛选枢纽基因,并针对枢纽基因进行基因本体富集分析和初步验证。富集分析和文献挖掘一致发现,某些枢纽基因确实与多种癌症的发生与发展存在显著的关联。权重基因共表达网络分析方法被证明是一个高效的系统生物学方法,应用该方法发现了新的HBV相关性肝癌枢纽基因。经实验验证,发现枢纽基因SHARPIN促进细胞迁移。该研究对肝癌发生的调控机制以及发现HBV慢性感染导致肝癌的新型诊断标志物和(或)药物作用靶点提供了新的视野。     

嗜冷嗜酸β-1,4-木聚糖酶及其钙离子依赖型碳水化合物结合模块

【目的】β-1,4-木聚糖酶是木聚糖降解的关键酶之一,嗜冷嗜酸木聚糖酶在功能性低聚木糖的制备中具有重要作用,但相关报道较少。【方法】从太平洋火色杆菌(Flammeovirga pacifica)菌株WPAGA1基因组发掘到一条新型的木聚糖酶序列,经基因合成、质粒构建和表达,并对其进行分离纯化及酶学性质研究。【结果】该木聚糖酶(Xyl4513)具有2个保守结构域,一个属于糖苷水解酶11家族(glycoside hydrolase family 11,GH11)催化模块(Xyl4513-T),另一个属于碳水化合物结合模块(carbohydrate-binding module,CBM) 60家族(CBM4513),这是一种非常罕见的GH11家族木聚糖酶含有CBM的现象。纯化后的Xyl4513最适反应温度和pH值分别为30℃、3.0,这一特性说明Xyl4513为嗜冷嗜酸β-1,4-木聚糖酶;而截短的木聚糖酶Xyl4513-T最适反应温度和pH值分别为20℃、4.0,且催化效率(k_cat/K_m)较前者下降了20%,说明CBM4513对酶稳定性和催化效...     

原生动物的细胞骨架蛋白及其功能组件

目前在原生动物中发现了许多新的细胞骨架蛋白,如中心元蛋白、副鞭毛杆蛋白等。深入研究发现,原生动物的细胞骨架在细胞的模式形成,细胞核的遗传中也具有重要作用。从功能组件角度着眼研究细胞骨架的功能,将有助于了解细胞骨架的进化机制。     

Promiscuous,non-catalytic,tandem carbohydrate-binding modules modulate the cell-wall structure and development of transgenic tobacco (<Emphasis Type="Italic">Nicotiana tabacum</Emphasis>) plants

We have compared heterologous expression of two types of carbohydrate binding module (CBM) in tobacco cell walls. These are the promiscuous CBM29 modules (a tandem CBM29-1-2 and its single derivative CBM29-2), derived from a non-catalytic protein1, NCP1, of the Piromyces equi cellulase/hemicellulase complex, and the less promiscuous tandem CBM2b-1-2 from the Cellulomonas fimi xylanase 11A. CBM-labelling studies revealed that CBM29-1-2 binds indiscriminately to every tissue of the wild-type tobacco stem whereas binding of CBM2b-1-2 was restricted to vascular tissue. The promiscuous CBM29-1-2 had much more pronounced effects on transgenic tobacco plants than the less promiscuous CBM2b-1-2. Reduced stem elongation and prolonged juvenility, resulting in delayed flower development, were observed in transformants expressing CBM29-1-2 whereas such growth phenotypes were not observed for CBM2b-1-2 plants. Histological examination and electron microscopy revealed layers of collapsed cortical cells in the stems of CBM29-1-2 plants whereas cellular deformation in the stem cortical cells of CBM2b-1-2 transformants was less severe. Altered cell expansion was also observed in most parts of the CBM29-1-2 stem whereas for the CBM2b-1-2 stem this was observed in the xylem cells only. The cellulose content of the transgenic plants was not altered. These results support the hypothesis that CBMs can modify cell wall structure leading to modulation of wall loosening and plant growth.     

Blood Group Antigen Recognition by a Solute-Binding Protein from a Serotype 3 Strain of Streptococcus pneumoniae

Streptococcus pneumoniae is a common bacterial pathogen that is well known for its ability to cause acute respiratory disease (pneumonia), ear infections, and other serious illnesses. This Gram-positive bacterium relies on its carbohydrate-metabolizing capabilities for full virulence in its host; however, the range of glycan targets that it can attack is presently not fully appreciated. S. pneumoniae is known to have a fucose utilization operon that in the TIGR4 strain plays a role in its virulence. Here we identify a second type of fucose utilization operon that is present in a subset of S. pneumoniae strains, including the serotype 3 strain SP3-BS71. This operon contains a transporter with a solute-binding protein, FcsSBP (fucose solute-binding protein), that interacts tightly (K_a ∼ 1 × 10⁶ M^− 1) and specifically with soluble A- and B-antigen trisaccharides but displays no selectivity between these two sugars. The structure of the FcsSBP in complex with the A-trisaccharide antigen, determined to 2.35 Å, reveals its mode of binding to the reducing end of this sugar, thus highlighting this protein's requirement for soluble blood group antigen ligands. Overall, this report exposes a heretofore unknown capability of certain S. pneumoniae strains to transport and potentially metabolize the histo-blood group antigen carbohydrates of its host.