A Process Study of Lactic Acid Production from Phragmites australis Straw by a Thermophilic Bacillus coagulans Strain under Non-Sterilized Conditions

Phragmites australis straw (PAS) is an abundant and renewable wetland lignocellulose. Bacillus coagulans IPE22 is a robust thermophilic strain with pentose-utilizing capability and excellent resistance to growth inhibitors. This work is focused on the process study of lactic acid (LA) production from P. australis lignocellulose which has not been attempted previously. By virtue of thermophilic feature of strain IPE22, two fermentation processes (i.e., separated process and integrated process), were developed and compared under non-sterilized conditions. The integrated process combined dilute-acid pretreatment, hemicellulosic hydrolysates fermentation, and cellulose utilization. Sugars derived from hemicellulosic hydrolysates and cellulose enzymatic hydrolysis were efficiently fermented to LA in a single vessel. Using the integrated process, 41.06 g LA was produced from 100 g dry PAS. The established integrated process results in great savings in terms of time and labor, and the fermentation process under non-sterilized conditions is easy to scale up for economical production of lactic acid from PAS

The Mechanism of Lipopolysaccharide’s Effect on Secretion of Endometrial Mucins in Female Mice during Pregnancy

The main toxic component of endotoxins released from the death or dissolution of Gram-negative bacteria is lipopolysaccharide (LPS), which exists widely in the natural environment, and a large amount of endotoxin can significantly inhibit the reproductive performance of animals. A previous study showed that endotoxins mainly damaged the physiological function of mucins in the endometrium, but the mechanism is not clear. In this study, the PI3K/Akt signaling pathway was not activated, and the NF-κB signaling pathway was inhibited by LPS treatment; the expression of occludin and E-cadherin proteins were decreased and ZO-1 protein expression was increased, because LPS can lead to the mucous layer becoming thinner, so that the embryonic survival rate is significantly reduced in early pregnancy. In middle and late pregnancy, LPS translocated to the epithelial cells of the uterus and the expression of claudin-1, JAMA, and E-cadherin proteins were decreased; at this time, a large number of glycosaminoglycan particles were secreted by endometrial gland cells through the PI3K/Akt/NF-κB signaling pathway that was activated after LPS treatment, However, there was no significant difference between the survival rates of fetal mice in the LPS (+) and LPS (-) groups. Glycosaminoglycan particles and mucins are secreted by gland cells, which can protect and maintain the pregnancy in the middle and late gestational periods

Chlorine-modulated tin oxide as an efficient catalyst toward carbon dioxide electrochemical reduction

Electrochemical conversion of CO2 into value-added chemicals such as formic acid shows promise in carbon neutralization for carbon-intensive manufacturing industry, such as ironsteel industry or ammonia production. However, low product selectivity and competitive hydrogen evolution over Sn-based catalysts severely lowers the energy efficiency of this process and increases the cost of downstream product separation. In this work, we demonstrated a facile strategy to improve conversion efficiency of CO2 at a relatively low overpotential by incorporating chlorine element into tin oxide. We found that the less electronegative chlorine than oxygen could lower the oxidation state of surface Sn to an optimal level for CO2 reduction. As a result, the chlorine-modulated Sn showed an overall CO2 conversion Faradaic efficiency of 82.9% at -0.783 V vs RHE, over 43% higher than those over commercial Sn foil and SnO2-derived nanoparticles

Consistent analysis of differentially expressed genes across 7 cell types in papillary thyroid carcinoma

Single-cell transcriptome sequencing (scRNA-seq) provides a higher resolution of cellular differences than bulk RNA-seq, enabling the dissection of cell-type-specific responses to perturbations in papillary thyroid carcinoma (PTC). However, cellular genomic features are highly heterogeneous and have a large number of genes without any expression signals, which hinders the statistical power to identify differentially expressed genes and may generate many false-positive results. To overcome this challenge, we conducted an integrative analysis on two PTC scRNA-seq datasets and cross-validated consistent differential expression. By combining results from 32 common cell types in the two studies, we identified 31 consistently differentially expressed genes (DEGs) across seven cell types, including B cells, endothelial cells, epithelial cells, monocytes, NK cells, smooth muscle cells, and T cells. Functional enrichment analysis revealed that these genes are important for the adaptive immune response and autoimmune thyroid diseases. The additional disease-free survival analysis also confirmed that these 31 genes significantly affected patient survival time in large scale thyroid cancer cohort. Furthermore, we experimentally validated one of the top consistent DEGs as a potential biomarker gene of PTC epithelial cells, KRT7, which may be a upstream gene for the NF-κB signaling pathway. The result shows that KRT7 may promote thyroid cancer metastasis through the epithelial-mesenchymal transition and NF-κB signaling pathway. In summary, our single-cell transcriptome integration-based approach may provide insights into the important role of NF-κB in the underlying biology of the PTC

Modulated Sn oxidation states over a Cu2O-derived substrate for selective electrochemical CO2 reduction

Pursuing high catalytic selectivity is challenging but paramount for an efficient and low-cost CO electrochemical reduction (COR). In this work, we demonstrate a significant correlation between the selectivity of COR to formate and the duration of tin (Sn) electrodeposition over a cuprous oxide (CuO)-derived substrate. A Sn electrodeposition time of 120 s led to a cathode with a formate Faradaic efficiency of around 81% at -1.1 V vs reversible hydrogen electrode (RHE), which was more than 37% higher than those of the Sn foil and the sample treated for 684 s. This result highlights the significant role of the interface between deposited Sn and the cuprous-derived substrate in determining the selectivity of COR. High-resolution X-ray photoelectron spectra revealed that the residual cuprous species at the Cu/Sn interfaces could stabilize Sn species in oxidation states of 2+ and 4+, a mixture of which is essential for a selective formate conversion. Such modulation effects likely arise from the moderate electronegativity of the cuprous species that is lower than that of Sn but higher than that of Sn. Our work highlights the significant role of the substrate in the selectivity of the deposited catalyst and provides a new avenue to advance selective electrodes for CO electrochemical reduction

Temporal variations and potential sources of organophosphate esters in PM2.5 in Xinxiang, North China

We monitored the concentrations of 10 organophosphate esters (OPEs) in 52 fine particulate matter (PM2.5) samples in Xinxiang, Henan Province, North China, in 2015. During the sampling period, the OPE concentrations in most samples (n = 47) differed minimally and were relatively stable (mean: 2.02 +/- 0.93 ng m(-3)), although several samples (n = 5) had high total OPE (Sigma 10OPE) concentrations (mean: 9.99 +/- 5.69 ng m(-3)), which may have been influenced by high PM2.5 levels. Meanwhile, some samples had high PM2.5 concentrations but low Sigma 10OPE concentrations (i.e. low OPE/PM2.5 ratios) or low PM2.5 concentrations but high Sigma 10OPE concentrations, which might have been influenced by air mass sources. Therefore, we assessed air mass sources using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and wind direction frequency data, and subsequently analysed PM2.5 and OPE sources using a potential source contribution function (PSCF) model. The results revealed that air mass sources couldn't represent the source of specific pollutants, including PM2.5 and OPEs. Generally, both PM2.5 and OPEs were from Henan and Shandong Provinces; however, the major source areas differed, which may have resulted from diverse pollution characteristics in various source areas. The principal component analysis and PSCF results revealed that the 10 OPEs could be segmented into three groups, which were associated with different source areas. These results suggested that pollution characteristics of contaminants in source areas should be considered in source apportionment. (C) 2018 Elsevier Ltd. All rights reserved

Insights into Persistent Toxic Substances in Protective Cases of Mobile Phones: Occurrence, Health Risks, and Implications

Despite the popularity of smartphones worldwide, persistent toxic substances (PTSs) in protective cases of mobile phones (PCMPs) and their health risks via direct skin contact have been ignored. This study investigated PTSs in PCMPs made in China with different materials and sales territory and their potential harm to human health. Polybrominated diphenyl ethers (PBDEs, 6.40 ng/g), new brominated flame retardants (NBFRs, 144 ng/g), organophosphate esters (OPEs, 10.1 mu g/g), short-chain chlorinated paraffins (SCCPs, 3.58 mu g/g), medium-chain chlorinated paraffins (MCCPs, 3.17 mu g/g), and heavy metals (HMs, 72.3 mu g/g) were detected. It was found that the different concentrations and compositions depend on the material, region, and use. Moreover, the raw materials used to fabricate PCMPs are of variable quality and may include recycled plastic waste. There are no standard quality specifications for PCMPs, and different materials have different properties, including specific surface area and adsorption ability. The risk assessment performed by Monte Carlo simulations indicated that the PTSs evaluated pose no health risks to the general population and may have adverse effects on individual high-exposure populations. According to the results of this work, it is suggested that more stringent global specifications for the selection of raw materials should be established, including the content and structural characteristics of PTSs, limitations on the use of additives in the production process, and the handling after use