The development of a highly photostable and chemically stable zwitterionic near-infrared dye for imaging applications

Chemical Communications51193989-399

Whole cell biosynthesis of a functional oligosaccharide, 2′-fucosyllactose, using engineered Escherichia coli

BACKGROUND: 2'-Fucosyllactose (2-FL) is a functional oligosaccharide present in human milk which protects against the infection of enteric pathogens. Because 2-FL can be synthesized through the enzymatic fucosylation of lactose with guanosine 5′-diphosphate (GDP)-l-fucose by α-1,2-fucosyltransferase (FucT2), an 2-FL producing Escherichia coli can be constructed through overexpressing genes coding for endogenous GDP- l-fucose biosynthetic enzymes and heterologous fucosyltransferase. RESULTS: The gene for FucT2 from Helicobacter pylori was introduced to the GDP- l-fucose producing recombinant E. coli BL21 star(DE3) strain. However, only small amount of 2-FL was produced in a batch fermentation because the E. coli BL21star(DE3) strain assimilated lactose instead of converting to 2-FL. As an alternative host, the E. coli JM109(DE3) strain which is incapable of assimilating lactose was chosen as a 2-FL producer. Whole cell biosynthesis of 2-FL from lactose was investigated in a series of batch fermentations using various concentrations of lactose. The results of batch fermentations showed that lactose was slowly assimilated by the engineered E. coli JM109(DE3) strain and 2-FL was synthesized without supplementation of another auxiliary sugar for cell growth. A maximum 2-FL concentration of 1.23 g/l was obtained from a batch fermentation with 14.5 g/l lactose. The experimentally obtained yield (g 2-FL/g lactose) corresponded to 20% of the theoretical maximum yield estimated by the elementary flux mode (EFM) analysis. CONCLUSIONS: The experimental 2-FL yield in this study corresponded to about 20% of the theoretical maximum yield, which suggests further modifications via metabolic engineering of a host strain or optimization of fermentation processes might be carried out for improving 2-FL yield. Improvement of microbial production of 2-FL from lactose by engineered E. coli would increase the feasibility of utilizing 2-FL as a prebiotic in various foods

Sugar transporter engineering in yeast to enable simultaneous co-utilization of sugars prevalent in cellulosic hydrolysates

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Intrinsically Stretchable Three Primary Light-Emitting Films Enabled By Elastomer Blend For Polymer Light-Emitting Diodes

Intrinsically stretchable light-emitting materials are crucial for skin-like wearable displays; however, their color range has been limited to green-like yellow lights owing to the restricted stretchable light-emitting materials (super yellow series materials). To develop skin-like full-color displays, three intrinsically stretchable primary light-emitting materials [red, green, and blue (RGB)] are essential. In this study, we report three highly stretchable primary light-emitting films made from a polymer blend of conventional RGB light-emitting polymers and a nonpolar elastomer. The blend films consist of multidimensional nanodomains of light-emitting polymers that are interconnected in an elastomer matrix for efficient light-emitting under strain. The RGB blend films exhibited over 1000 cd/m2 luminance with low turn-on voltage (Von) and the selectively stretched blend films on rigid substrate maintained stable light-emitting performance up to 100% strain even after 1000 multiple stretching cycles

Activation of spleen tyrosine kinase is required for TNF-α-induced endothelin-1 upregulation in human aortic endothelial cells

AbstractEndothelin-1 (ET-1) promotes atherosclerosis. We tested whether spleen tyrosine kinase (Syk) mediates tumor necrosis factor-α (TNF-α)-induced ET-1 upregulation in human aortic endothelial cells (HAECs) and sought to identify the signal pathways involved. TNF-α-induced reactive oxygen species (ROS) activated Syk and phosphatidylinositol 3-kinase (PI3K), which was required for the activation of AP-1 and subsequent ET-1 gene transcription. ROS mediated c-Jun NH2-terminal kinase (JNK) is also required for AP-1 activation, but Syk and PI3K regulated AP-1 activation independently of JNK. Through regulation of ET-1 production, Syk could be implicated in atherosclerosis

Carbonic anhydrase XII expression is associated with histologic grade of cervical cancer and superior radiotherapy outcome

BACKGROUND: To investigate whether expression of carbonic anhydrase XII (CA12) is associated with histologic grade of the tumors and radiotherapy outcomes of the patients with invasive cervical cancer. METHODS: CA12 expression was examined by immunohistochemical stains in cervical cancer tissues from 183 radiotherapy patients. Histological grading was classified as well (WD), moderately (MD) or poorly differentiated (PD). Oligonucleotide microarray experiment was performed using seven cervical cancer samples to examine differentially expressed genes between WD and PD cervical cancers. The association between CA12 and histological grade was analyzed by chi-square test. CA12 and histological grades were analyzed individually and as combined CA12 and histologic grade categories for effects on survival outcome. RESULTS: Immunohistochemical expression of CA12 was highly associated with the histologic grade of cervical cancer. Lack of CA12 expression was associated with PD histology, with an odds ratio of 3.9 (P = 0.01). Microarray analysis showed a fourfold reduction in CA12 gene expression in PD tumors. CA12 expression was marginally associated with superior disease-free survival. Application of the new combined categories resulted in further discrimination of the prognosis of patients with moderate and poorly differentiated tumor grade. CONCLUSIONS: Our study indicates that CA12 may be used as a novel prognostic marker in combination with histologic grade of the tumors