Constructing hydrogen bond based melam/WO3 heterojunction with enhanced visible-light photocatalytic activity

Hydrogen bond based visible-light-response heterojunction photocatalyst Melam/WO3 (MW) has been fabricated for the first time by facile planetary milling treatment. Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric (TG) analysis reveal the formation of hydrogen bonds (NH···O) between melam and WO3. As compared to WO3, the MW not only complete decomposes acetaldehyde, but also shows 10 times and 12 times higher photocatalytic activity for photo-degradation of 2-propanol and photo-generation of H2O2, respectively, under the visible-light irradiation. X-ray photoelectron spectroscopy suggests that the potential difference between N and O (N+H⋯O−) in the heterojunction provides the driving force for the charge transfer from WO3 to melam. Furthermore, hydrogen bonds offer an ultrafast electron pathway for heterojunction. This study demonstrates that hydrogen bond based heterojunction could be a promising approach for developing a new photocatalyst with efficient visible-light photocatalytic activity

Ventilation control of road tunnels towards disturbance suppression

Abstract In recent years, research on ventilating tunnels has become increasingly important. However, the impact of external disturbances on ventilating systems has been largely ignored. To address this issue of frequent airflow fluctuations caused by external perturbations, which cannot be fully compensated using conventional control methods, this study proposes a perturbation-compensated ventilation control approach. A disturbance compensator is developed by incorporating the tunnel’s airflow velocity and the number of jet fan start-stop events as input parameters. By compensating for external disturbances, the disturbance to the system is reduced. The Simulink model of the tunnel controller was used for simulation experiments. The compensator demonstrated good tracking results in comparison experiments with different disturbances. The ventilation approach based on disturbance compensator is capable of regulating the fluctuation of CO concentration within a justifiable range compared to using PID control and ADRC. This not only improves the stability of the entire control system but also significantly prolongs the service life of the jet fan by reducing the frequency of start-stop cycles

Constructing hydrogen bond based melam/WO3 heterojunction with enhanced visible-light photocatalytic activity

Hydrogen bond based visible-light-response heterojunction photocatalyst Melam/WO3 (MW) has been fabricated for the first time by facile planetary milling treatment. Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric (TG) analysis reveal the formation of hydrogen bonds (NH···O) between melam and WO3. As compared to WO3, the MW not only complete decomposes acetaldehyde, but also shows 10 times and 12 times higher photocatalytic activity for photo-degradation of 2-propanol and photo-generation of H2O2, respectively, under the visible-light irradiation. X-ray photoelectron spectroscopy suggests that the potential difference between N and O (N+H⋯O−) in the heterojunction provides the driving force for the charge transfer from WO3 to melam. Furthermore, hydrogen bonds offer an ultrafast electron pathway for heterojunction. This study demonstrates that hydrogen bond based heterojunction could be a promising approach for developing a new photocatalyst with efficient visible-light photocatalytic activity

Nitrogen and sulfur co-doped CeO2 nanorods for efficient photocatalytic VOCs degradation

Ceria and its derivatives are environmentally-friendly and sustainable photocatalysts with a strong oxygen storage/release ability, good photostability, and high cost-effectiveness. In this work, nitrogen and sulfur synchronously doped ceria (NS-CeO2) with a regular nanorod morphology was successfully prepared, in which doping was obtained just from one precursor and by one-step calcination treatment. The photooxidation performance of acetaldehyde on NS-CeO2 was significantly better than that on undoped ceria. As confirmed by density functional theory (DFT) calculations, the oxygen atoms exposed on the surface were partially replaced after doping with nitrogen and sulfur, resulting in the generation of new impurity level states near the Fermi level and reduction of the bandgap of NS-CeO2. Meanwhile, the increased concentration of oxygen vacancies formed a doping transition state which can act as an effective electron capture center. In addition, this transition state further exhibits a mediation role in interfacial charge separation due to its effective restriction of the recombination of electrons and holes, which can further improve the photocatalytic performance of NS-CeO2. Herein, an effective strategy for synthesizing non-metal doped CeO2-based semiconductor photocatalysts that can degrade volatile organic compounds is proposed

An exonic splicing enhancer mutation in DUOX2 causes aberrant alternative splicing and severe congenital hypothyroidism in Bama pigs

Pigs share many similarities with humans in terms of anatomy, physiology and genetics, and have long been recognized as important experimental animals in biomedical research. Using an N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we previously identified a large number of pig mutants, which could be further established as human disease models. However, the identification of causative mutations in large animals with great heterogeneity remains a challenging endeavor. Here, we select one pig mutant, showing congenital nude skin and thyroid deficiency in a recessive inheritance pattern. We were able to efficiently map the causative mutation using family-based genome-wide association studies combined with whole-exome sequencing and a small sample size. A loss-of-function variant (c.1226 A>G) that resulted in a highly conserved amino acid substitution (D409G) was identified in the DUOX2 gene. This mutation, located within an exonic splicing enhancer motif, caused aberrant splicing of DUOX2 transcripts and resulted in lower H2O2 production, which might cause a severe defect in thyroid hormone production. Our findings suggest that exome sequencing is an efficient way to map causative mutations and that DUOX2D409G/D409G mutant pigs could be a potential large animal model for human congenital hypothyroidism

Reconstitution of UCP1 using CRISPR/Cas9 in the white adipose tissue of pigs decreases fat deposition and improves thermogenic capacity

Acknowledgments We thank members of the J.Z., W.J., and Y.W. laboratories for helpful discussions; P. Chai, S. Liu, H. Tang, and C. Wei (Institute of High Energy Physics at the Chinese Academy of Sciences and Beijing Engineering Research Center of Radiographic Techniques and Equipment) for their help with the PET scan experiments and analysis; L. Yang (Institute of Genetics and Developmental Biology at the Chinese Academy of Sciences) for help in TEM analysis; and Peter Thomson (University of Aberdeen) for technical assistance with isotope analysis. This study was supported by the National Transgenic Project of China (Grant 2016ZX08009003-006-007), the Strategic Priority Research Programs of the Chinese Academy of Sciences (Grants XDA08010304 and XDB13030000), the National Natural Science Foundation of China (Grants 81671274 and 31272440), and the National Program on Key Basic Research Project (973 Program; Grant 2015CB943100). Y.W. was supported by the Elite Youth Program of the Chinese Academy of Agricultural Sciences (ASTIP-IAS05). This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1707853114/-/DCSupplemental.Peer reviewedPostprin