In Situ Construction of CuTCPP/Bi4O5Br2 Hybrids for Improved Photocatalytic CO2 and Cr(VI) Reduction.

Global warming and heavy metal pollution pose tremendous challenges to human development, and photocatalysis is considered to be an effective strategy to solve these problems. Herein, copper(II) tetra (4-carboxyphenyl) porphyrin (CuTCPP) molecules were successfully in situ loaded onto Bi4O5Br2 by a hydrothermal approach. A series of experimental results show that the light absorption capacity and photogenerated carrier separation efficiency were synchronously enhanced after the construction of CuTCPP/Bi4O5Br2 composites. Hence, the as-prepared composites possess significantly improved photocatalytic ability for both CO2 and Cr(VI) reduction. Specifically, CuTCPP/Bi4O5Br2-2 achieves a CO generation rate of 17.14 µmol g-1 under 5 h irradiation, which is twice as high as that of Bi4O5Br2 (8.57 µmol g-1). Besides, the optimized CuTCPP/Bi4O5Br2-2 also exhibits a removal rate of 61.87% for Cr(VI) within 100 min under irradiation. Furthermore, the mechanism of CO2 and Cr(VI) photoreduction was explored by in situ Fourier transform infrared spectroscopy and capture experiments, respectively. This work can be a reference toward the construction of photocatalysts with high activity for solar energy conversion.

Semimetallic Bismuthene with Edge-Rich Dangling Bonds: Broad-Spectrum-Driven and Edge-Confined Electron Enhancement Boosting CO2 Hydrogenation Reduction.

Broad-spectrum-driven high-performance artificial photosynthesis is quite challenging. Herein, atomically ultrathin bismuthene with semimetallic properties is designed and demonstrated for broad-spectrum (ultraviolet-visible-near infrared light) (UV-vis-NIR)-driven photocatalytic CO2 hydrogenation. The trap states in the bandgap produced by edge dangling bonds prolong the lifetime of the photogenerated electrons from 90 ps in bulk Bi to 1650 ps in bismuthine, and excited-state electrons are enriched at the edge of bismuthine. The edge dangling bonds of bismuthene as the active sites for adsorption/activation of CO2 increase the hybridization ability of the Bi 6p orbital and O 2p orbital to significantly reduce the catalytic reaction energy barrier and promote the formation of C─H bonds until the generation of CH4. Under λ ≥ 400 nm and λ ≥ 550 nm irradiation, the utilization ratios of photogenerated electron reduction CO2 hydrogenation to CO and CH4 for bismuthene are 58.24 and 300.50 times higher than those of bulk Bi, respectively. Moreover, bismuthene can extend the CO2 hydrogenation reaction to the near-infrared region (λ ≥ 700 nm). This pioneering work employs the single semimetal element as an artificial photosynthetic catalyst to produce a broad spectral response.

Synergy between plasmonic and sites on gold nanoparticle-modified bismuth-rich bismuth oxybromide nanotubes for the efficient photocatalytic CC coupling synthesis of ethane.

The photocatalytic reduction of carbon dioxide (CO2) to fossil fuels has attracted widespread attention. However, obtaining the high value-added hydrocarbons, especially C2+ products, remains a considerable challenge. Herein, gold (Au) nanoparticle-modified bismuth-rich bismuth oxybromide Bi12O17Br2 nanotube composites were designed and tested. Au nanoparticles act as electron traps and thermal electron donors that promote the efficient separation and migration of carriers to form the C2+ product. As a result, compared with the pure Bi12O17Br2 nanotubes, Au@Bi12O17Br2 composites can not only produce the carbon monoxide (CO) and methane (CH4), but also covert CO2 into ethane (C2H6). In this study, Au@Bi12O17Br2-700 was used to obtain a C2H6 production rate of 29.26 µmol h-1 g-1. The selectivities during a 5-hour test reached 94.86% for hydrocarbons and 90.81% for C2H6. The proposed approach could be used to design high-performance photocatalysts to convert CO2 into high value-added hydrocarbon products.

Edge-Site-Rich Ordered Macroporous BiOCl Triggers CO Activation for Efficient CO2 Photoreduction.

Endowing a semiconductor with tunable edge active sites will effectively enhance catalytic performance. Herein, an edge-site-rich ordered macroporous BiOCl (BiOCl-P) with abundant dangling bonds is constructed via the colloidal crystal template method. The edge-site-rich ordered macroporous structure provides abundant adsorption sites for CO2 molecules, as well as forms numerous localized electron enrichment areas, accelerating charge transfer. DFT calculations reveal that the dangling bonds-rich configuration can effectively reduce the CO2 activation energy barrier, boost the CO double bond dissociation, and facilitate the proton electron coupling reaction. As a result, the BiOCl-P achieves a higher CO and CH4 generation rate of 78.07 and 3.03 µmol g-1 under 4 h Xe lamp irradiation in a solid-gas system. Finally, the CO2 molecules' conversion process is further investigated by in situ Fourier-transform infrared spectroscopy. This work realizes a new avenue toward the design of vibrant semiconductors on the nanoscale to boost inert CO2 photoreduction.

Oxygen vacancies mediated Bi12O17Cl2 ultrathin nanobelts: Boosting molecular oxygen activation for efficient organic pollutants degradation.

Photocatalysis technology has been considered as a sustainable and promising strategy for pollutant degradation. However, the photocatalytic activity is limited by the unsatisfactory carrier separation efficiency of photocatalysts and insufficient reactive oxygen species. Herein, the oxygen vacancies (OVs) mediated Bi12O17Cl2 ultra-thin nanobelt (ROV Bi12O17Cl2) was fabricated via solvothermal method. The surface oxygen vacancies can act as the 'electron sink' and boost charge separation. Thus, the ROV Bi12O17Cl2 shows superior photocatalytic performance, which is 2.72 and 4.52 times compared to deficient oxygen vacancies Bi12O17Cl2 (DOV Bi12O17Cl2) and Bulk Bi12O17Cl2 for colored organic pollutants degradation, respectively. Besides, the ROV Bi12O17Cl2 also displays excellent removal efficiency for refractory antibiotics, roughly 4.00 and 7.45 times compared to that of DOV Bi12O17Cl2 and Bulk Bi12O17Cl2, respectively. Furthermore, the intermediates for photocatalytic degradation were determined through HPLC-MS and the possible degradation paths of the target molecules were inferred. Capture experiment and ESR spectra confirmed that the •O2- played a vital role for the organic pollutant degradation. This work provides a new perspective for the design of advanced semiconductors for organic pollutants degradation.

AMPK-mTOR-ULK1-mediated autophagy protects carbon tetrachloride-induced acute hepatic failure by inhibiting p21 in rats.

Autophagy is a lysosomal-dependent degradation pathway in eukaryotic cells. Recent studies have reported that autophagy can facilitate the activation of hepatic stellate cells (HSCs) and fibrogenesis of the liver during long-term carbon tetrachloride (CCl4) exposure. However, little is known about the role of autophagy in CCl4-induced acute hepatic failure (AHF). This study aimed to identify whether modulation of autophagy can affect CCl4-induced AHF and evaluate the upstream signaling pathways mediated by CCl4-induced autophagy in rats. The accumulation of specific punctate distribution of endogenous LC3-II, increased expression of LC3-II, Atg5, and Atg7 genes/proteins, and decreased expression of p62 gene were observed after acute liver injury was induced by CCl4 in rats, indicating that CCl4 resulted in a high level of autophagy. Moreover, loss of autophagic function by using chloroquine (CQ, an autophagic inhibitor) aggravated liver function, leading to increased expression of p21 (a cyclin-dependent kinase inhibitor) in CCl4-treated rats. Furthermore, the AMPK-mTORC1-ULK1 axis was found to serve a function in CCl4-induced autophagy. These results reveal that AMPK-mTORC1-ULK1 signaling-induced autophagy has a protective role in CCl4-induced hepatotoxicity by inhibiting the p21 pathway. This study suggests a useful strategy aimed at ameliorating CCl4-induced acute hepatotoxicity by autophagy.

A Janus cobalt nanoparticles and molybdenum carbide decorated N-doped carbon for high-performance overall water splitting.

The fabrication of high-performance and stable electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of importance for sustainable water-splitting technologies. Herein, the cobalt (Co) nanoparticles and molybdenum carbide (Mo2C) heterostructures anchored N-doped carbon (Co/Mo2C@NC-800) was designed as bifunctional electrocatalyst for overall water splitting via a simple pyrolysis approach for metal organic frameworks (MOFs) precursor. This composite shows a remarkable performance for HER and OER with a small overpotential of 121 mV and 311 mV at 10 mA cm-2, respectively. When the optimized electrocatalyst was employed as both anode and cathode for overall water splitting in a two-electrode system, the electrolyzer achieves a low cell voltage of 1.67 V at 10 mA cm-2 in 1 M KOH, as well as a superior and stable long-time operation of 30 h. The promising hybrid material demonstrates excellent electrocatalysis performance due to effective combination of the best of both worlds: Mo2C with remarkable HER performance and Co nanoparticles with excellent OER activity. The Mo2C possesses strong hydrogen binding energy and Co exhibits prominent electrical conductivity, thus the construction of heterostructures achieves more active sites with different functions and significantly boosts HER and OER process. The novel and effective synthesis strategy provides new insights into the design of outstanding non-noble metal bifunctional electrocatalysts for overall water splitting.

Simultaneous detection of five pig viruses associated with enteric disease in pigs using EvaGreen real-time PCR combined with melting curve analysis.

In recent years, a series of porcine diarrhea viruses such as porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), rotaviruses of group A (RVA), rotaviruses of group C (RVC), and porcine circovirus 2 (PCV2) caused enormous economic losses all over the world. While any of these viruses is capable to cause disease alone, there is often concurrent infection with more than one virus on pig farms. In this study, a multiplex real-time PCR method based on EvaGreen fluorescent dye and melting curve analysis was established to simultaneously detect these five viruses in a single closed tube. Five distinct melt peaks were obtained with different melting temperature (Tm) value corresponding to each of the five viruses. This method was highly sensitive to detect and distinguish TGEV, RVA, RVC, PEDV and PCV2 with the limits of detection ranging from 5 to 50 copies/µL. The intra-assay and inter-assay reproducibility were good with coefficient of variation of Tm and cycle threshold values less than 0.32% and 2.86%, respectively. Testing of 90 field samples by the single and multiplex real-time PCR assays demonstrated a concordance of 91.1%. Thus, the EvaGreen multiplex real-time PCR is a rapid, sensitive and low-cost diagnostic tool for differential detection and routine surveillance of TGEV, RVA, RVC, PEDV and PCV2 in pigs.

Detection and differentiation of five diarrhea related pig viruses utilizing a multiplex PCR assay.

Porcine viral diarrhea, mainly caused by porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine group A rotaviruses (RVA), porcine group C rotaviruses (RVC) and porcine circovirus 2 (PCV2), is a serious global problem, resulting in substantial economic losses to the swine industry. For fast and reliable diagnosis of the causative agent associated with viral diarrhea in pigs, an inexpensive and easy to perform gel-based multiplex PCR assay was developed in this study to detect and differentiate the different viruses by amplicon size. The assay was able to distinguish between all five viral agents without cross-reacting with other non-target pig viruses. The detection limits of the assay per reaction were 5 copies for PEDV, TGEV, RVC and PCV2 and 50 copies for RVA for the singleplex assays and 50 copies when all five viruses were multiplexed. Sixty-nine field samples were used to validate the developed multiplex assay. The overall prevalence of positive samples was 44.9% (31/69). PCV2 was detected in 37.7% of the samples, PEDV and RVC each in 4.3%, TGEV in 2.9%, and RVA was detected in 1.4% of the samples tested. A total of 5.8% of the samples were co-infected by two or more viruses, and the results of the multiplex assay were in agreement to those obtained by single PCR assays. These findings suggest that the developed cost-effective multiplex assay is specific, sensitive, and will serve as a valuable diagnostic tool for the rapid differential detection of these five viruses and for molecular epidemiological studies and diarrhea disease management.

Novel mesoporous graphitic carbon nitride modified PbBiO2Br porous microspheres with enhanced photocatalytic performance.

Sustainable mesoporous graphitic carbon nitride (mpg-C3N4) modified PbBiO2Br porous microsphere (mpg-C3N4/PbBiO2Br) had been successfully synthesized via solvothermal process. Multiple techniques were applied to explore the structure, morphology, optical and electronic properties of the as-prepared photocatalysts. It could be found that the mpg-C3N4 was uniformly distributed on the surface of the PbBiO2Br porous microsphere. Compared with the pure PbBiO2Br, the mpg-C3N4/PbBiO2Br exhibited superior photocatalytic activity for the degradation of organic pollutants under visible light irradiation. When the mass fraction of mpg-C3N4 was 3%, the mpg-C3N4/PbBiO2Br composite materials exhibited the highest photocatalytic performance. The results indicated that the introduction of mpg-C3N4 could effectively enhance the electron mobility to promote the catalytic activity. The enhanced photocatalytic activity of the mpg-C3N4/PbBiO2Br materials can be attributed to the stronger optical trapping capability and the more effective separation efficiency of photogenerated electron-hole pairs. During the process of photocatalysis, the main active species of the photocatalysts were determined to be the and hole under visible light irradiation. Based on the relative band positions of mpg-C3N4 and PbBiO2Br, a possible photocatalytic mechanism of mpg-C3N4/PbBiO2Br composite catalyst was proposed.

Development and validation of a multiplex conventional PCR assay for simultaneous detection and grouping of porcine bocaviruses.

Porcine bocavirus (PBoV), a newly described porcine parvovirus, has received attention because it can be commonly identified in clinically affected pigs including pigs with post-weaning multisystemic wasting syndrome (PWMS) and pigs with diarrhea. In recent years, novel PBoVs have been identified and were classified into three genogroups, but the ability to detect and classify these novel PBoVs is not comprehensive to date. In this study, a multiplex conventional PCR assay for simultaneous detection and grouping of PBoVs was developed by screening combinations of mixed primer pairs followed by optimization of the PCR conditions. This method exclusively amplifies targeted fragments of 531bp from the VP1 gene of PBoV G1, 291bp from the NP1 gene of PBoV G2, and 384bp from the NP1/VP1 gene of PBoV G3. The assay has a detection limit of 1.0×10(3)copies/µL for PBoV G1 4.5×10(3) for PBoV G2 and 3.8×10(3) for PBoV G3 based on testing mixed purified plasmid constructs containing the specific viral target fragments. The performance of the multiplex PCR assay was comparable to that of the single PCRs which used the same primer pairs. Using the newly established multiplex PCR assay, 227 field samples including faeces, serum and tissue samples from pigs were investigated. All three PBoV genogroups were detected in the clinical samples with a detection rate of 1.3%, 2.6% and 12.3%, respectively for PBoV G1, G2 and G3. Additionally, coinfections with two or more PBoV were detected in 1.7% of the samples investigated. These results indicate the multiplex PCR assay is specific, sensitive and rapid, and can be used for the detection and differentiation of single and multiple infections of the three PBoV genogroups in pigs.

Rapid detection and grouping of porcine bocaviruses by an EvaGreen(®) based multiplex real-time PCR assay using melting curve analysis.

Several novel porcine bocaviruses (PBoVs) have been identified in pigs in recent years and association of these viruses with respiratory signs or diarrhea has been suggested. In this study, an EvaGreen(®)-based multiplex real-time PCR (EG-mPCR) with melting curve analysis was developed for simultaneous detection and grouping of novel PBoVs into the same genogroups G1, G2 and G3. Each target produced a specific amplicon with a melting peak of 81.3 ± 0.34 °C for PBoV G1, 78.2 ± 0.37 °C for PBoV G2, and 85.0 ± 0.29 °C for PBoV G3. Non-specific reactions were not observed when other pig viruses were used to assess the EG-mPCR assay. The sensitivity of the EG-mPCR assay using purified plasmid constructs containing the specific viral target fragments was 100 copies for PBoV G1, 50 for PBoV G2 and 100 for PBoV G3. The assay is able to detect and distinguish three PBoV groups with intra-assay and inter-assay variations ranging from 0.13 to 1.59%. The newly established EG-mPCR assay was validated with 227 field samples from pigs. PBoV G1, G2 and G3 was detected in 15.0%, 25.1% and 41.9% of the investigated samples and coinfections of two or three PBoV groups were also detected in 25.1% of the cases, indicating that all PBoV groups are prevalent in Chinese pigs. The agreement of the EG-mPCR assay with an EvaGreen-based singleplex real-time PCR (EG-sPCR) assay was 99.1%. This EG-mPCR will serve as a rapid, sensitive, reliable and cost effective alternative for routine surveillance testing of multiple PBoVs in pigs and will enhance our understanding of the epidemiological features and possible also pathogenetic changes associated with these viruses in pigs.