Development of a direct monitoring approach of CO/H₂ in bioreactors for syngas to biofuels conversion

Syngas fermentation is a novel technology to produce biofuels from syngas using acetogens. Precise monitoring of dissolved CO/H₂ concentrations helps to maintain the proper activities of the acetogens and is of great importance for a high product yield and operation stability. A new approach was developed to measure the dissolved CO/H₂ concentration with optical sensing and electrochemical methods, respectively.An indirect mid-infrared measurement system was developed to measure dissolved CO concentration. The measurement system included a gas extraction system for dissolved CO degasification and a non-dispersive mid-infrared CO sensor for gas phase CO concentration measurement. The gas extraction system used a hollow fiber membrane contactor to extract dissolved CO in a fixed volume of liquid sample. A vacuum was applied to the contactor to accelerate the degasification. The non-dispersive mid-infrared CO sensor used a room-temperature, mid-infrared light emitting diode as a mid-infrared source. The sensor was designed to detect CO absorption in the mid-infrared range between 4.7 µm and 4.9 µm as this range has minimal spectral interference from other chemicals in the syngas fermentation. The infrared signal was detected with a thermoelectric cooled photodetector. A digital lock-in amplifier was designed to improve the quality of the collected signals from the preamplifier.A commercial electrochemical dissolved H₂ sensor was introduced to measure the dissolved H₂ concentration. An integrated dissolved CO/H₂ measurement system was built by integrating the dissolved H₂ sensor to the developed dissolved CO measurement system. Performance evaluation of the integrated measurement system showed a maximum mean absolute percentage error of 10.83% and a root-mean-square error of 1.40 mg/L for the dissolved CO concentration measurement. The measurement on the dissolved H₂ concentration measurement was affected by the supersaturated dissolved H₂.The developed integrated measurement system provides a new method that can measure the dissolved CO/H₂ concentrations in the syngas fermentation medium. The method would be helpful to future optimization and commercialization of the syngas fermentation technology

Evaluation for Core Competence of Private Enterprises in Xuchang City Based on an Improved Dynamic Multiple-Attribute Decision-Making Model

Because Deng’s grey relational degree is inconspicuous, Deng’s relational degree with an exponential function is first presented. Then, we demonstrate that improved Deng’s relational degree is more conspicuous than the original model. Then, we construct a multiple-attribute decision-making model, based on improved Deng’s relational degree with multiple stages, and a method for determining the weight of the index is also developed. Finally, the core competence of private enterprises in Henan province is analyzed, illustrating the validity and feasibility of the improved model

Strong convergence of a km iterative algorithm for computing a split common fixed-point of quasi-nonexpansive operators

A modified Krasnoselski-Mann iterative algorithm is proposed for solving the split common fixed-point problem for quasi-nonexpansive operators. A parameter sequence is introduced to enhance convergence. It is shown that the proposed iterative algorithm strongly converges to a split common fixed-point in Hilbert spaces. This result extends the applicability of the KM algorithm

In Situ Absorption in Rat Intestinal Tract of Solid Dispersion of Annonaceous Acetogenins

Isolated from Annona squamosa L, Annonaceous acetogenins (ACGs) exhibit a broad range of biological properties yet absorbed badly due to the low solubility. Solid dispersion in polyethylene glycol 4000 (PEG 4000) has been developed to increase the solubility and oral absorption of ACGs. The formulation of ACGS-solid dispersion was optimized by a simplex lattice experiment design and carried out by a solvent-fusion method. We studied the absorption property of ACGs in rat's intestine, which showed there was a good absorption and uptake percentages with solid dispersion. The study on uptake percentage in different regions of rat's intestine attested that the duodenum had the best permeability, followed by jejunum, ileum, and colon in order with no significant differences. So the paper drew the conclusion that solid dispersion could improve the solubility and oral absorption of annonaceous acetogenins

Sustained oxygenation accelerates diabetic wound healing by promoting epithelialization and angiogenesis and decreasing inflammation

Nonhealing diabetic wounds are common complications for diabetic patients. Because chronic hypoxia prominently delays wound healing, sustained oxygenation to alleviate hypoxia is hypothesized to promote diabetic wound healing. However, sustained oxygenation cannot be achieved by current clinical approaches, including hyperbaric oxygen therapy. Here, we present a sustained oxygenation system consisting of oxygen-release microspheres and a reactive oxygen species (ROS)-scavenging hydrogel. The hydrogel captures the naturally elevated ROS in diabetic wounds, which may be further elevated by the oxygen released from the administered microspheres. The sustained release of oxygen augmented the survival and migration of keratinocytes and dermal fibroblasts, promoted angiogenic growth factor expression and angiogenesis in diabetic wounds, and decreased the proinflammatory cytokine expression. These effects significantly increased the wound closure rate. Our findings demonstrate that sustained oxygenation alone, without using drugs, can heal diabetic wounds

Integrative Analyses of Transcriptome Sequencing Identify Functional miRNAs in the Chicken Embryo Fibroblasts Cells Infected With Reticuloendotheliosis Virus

In this study, we found a much higher proportion of reticuloendotheliosis virus (REV) infected chicken embryo fibroblasts (CEF) were in active cell division phase than that of control cells which indicated that REV can affect the fate of CEF. So, we performed high-throughput sequencing and transcriptomic analysis to identify functional miRNAs, in order to figure out the possible mechanism in the interaction of REV with CEF. In total, 50 differentially expressed miRNAs (DEmiRNAs) were identified. Then target genes of DEmiRNAs were predicted and identified by transcriptome profile results. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were conducted to analyze the identified target genes of miRNAs which showed that metabolism, cell cycle, and apoptosis were the most related pathways involved in infection of REV. We analyzed the genes related to cell cycle which indicated that CyclinD1-CDK6 complex played an important role in regulating the transition of the cell cycle from G1 phase to S phase during REV infection. Fluorescence microscope identification showed that REV inhibited the apoptosis of CEF which was in accordance with transcriptome results. A novel miRNA, named novel-72 was found, KEGG analysis was conducted to predict the biological function of its target genes which showed that those target genes were significantly enriched in mTOR signaling pathway and functioned to promote cell cycle and cell growth during the REV infection. In conclusion, REV could induce the up-regulation of cell metabolism, cell cycle and mTOR signaling pathway while inhibit apoptosis of the cell

High-Temperature Polyimide Dielectric Materials for Energy Storage

The availability of high-temperature dielectrics is key to develop advanced electronics and power systems that operate under extreme environmental conditions. In the past few years, many improvements have been made and many exciting developments have taken place. However, currently available candidate materials and methods still do not meet the applicable standards. Polyimide (PI) was found to be the preferred choice for high-temperature dielectric films development due to its thermal stability, dielectric properties, and flexibility. However, it has disadvantages such as a relatively low dielectric permittivity. This chapter presents an overview of recent progress on PI dielectric materials for high-temperature capacitive energy storage applications. In this way, a new molecular design of the skeleton structure of PI should be performed to balance size and thermal stability and to optimize energy storage property for high-temperature application. The improved performance can be generated via incorporation of inorganic units into polymers to form organic-inorganic hybrid and composite structures

Mannose-6-phosphate regulates destruction of lipid-linked oligosaccharides.

Mannose-6-phosphate (M6P) is an essential precursor for mannosyl glycoconjugates, including lipid-linked oligosaccharides (LLO; glucose(3)mannose(9)GlcNAc(2)-P-P-dolichol) used for protein N-glycosylation. In permeabilized mammalian cells, M6P also causes specific LLO cleavage. However, the context and purpose of this paradoxical reaction are unknown. In this study, we used intact mouse embryonic fibroblasts to show that endoplasmic reticulum (ER) stress elevates M6P concentrations, leading to cleavage of the LLO pyrophosphate linkage with recovery of its lipid and lumenal glycan components. We demonstrate that this M6P originates from glycogen, with glycogenolysis activated by the kinase domain of the stress sensor IRE1-α. The apparent futility of M6P causing destruction of its LLO product was resolved by experiments with another stress sensor, PKR-like ER kinase (PERK), which attenuates translation. PERK's reduction of N-glycoprotein synthesis (which consumes LLOs) stabilized steady-state LLO levels despite continuous LLO destruction. However, infection with herpes simplex virus 1, an N-glycoprotein-bearing pathogen that impairs PERK signaling, not only caused LLO destruction but depleted LLO levels as well. In conclusion, the common metabolite M6P is also part of a novel mammalian stress-signaling pathway, responding to viral stress by depleting host LLOs required for N-glycosylation of virus-associated polypeptides. Apparently conserved throughout evolution, LLO destruction may be a response to a variety of environmental stresses.This work is supported by NIH grants DK-042394, HL-052173, and HL-057346 to R.J.K.; by NIH grants AI-073898 and GM-056927 to I.M.; by NIH grant R-37-DK047119 and a Principal Research Fellowship from the Wellcome Trust to D.R.; by NIH grant GM-031278 and support from the Robert Welch Foundation to J.R.F.; and by NIH grant GM-038545 and Robert Welch Foundation grant I-1168 to M.A.L

Patrilineal Perspective on the Austronesian Diffusion in Mainland Southeast Asia

The Cham people are the major Austronesian speakers of Mainland Southeast Asia (MSEA) and the reconstruction of the Cham population history can provide insights into their diffusion. In this study, we analyzed non-recombining region of the Y chromosome markers of 177 unrelated males from four populations in MSEA, including 59 Cham, 76 Kinh, 25 Lao, and 17 Thai individuals. Incorporating published data from mitochondrial DNA (mtDNA), our results indicated that, in general, the Chams are an indigenous Southeast Asian population. The origin of the Cham people involves the genetic admixture of the Austronesian immigrants from Island Southeast Asia (ISEA) with the local populations in MSEA. Discordance between the overall patterns of Y chromosome and mtDNA in the Chams is evidenced by the presence of some Y chromosome lineages that prevail in South Asians. Our results suggest that male-mediated dispersals via the spread of religions and business trade might play an important role in shaping the patrilineal gene pool of the Cham people