Low-nitrite generation Cu-Co/Ti cathode materials for electrochemical nitrate reduction.

In order to reduce by-product nitrite, a more toxic compound than nitrate, and increase high value-added products ammonia in the electrochemical reduction nitrate process, the novel Cu-Co/Ti cathode material was applied in this process. In this paper, the electrochemical process was carried out in a single compartment electrolytic cell, and with Cu-Co/Ti electrode as cathode, identifying the effects of current density, pH, electrolytes in the nitrate reduction, and the distribution of products. The Cu-Co/Ti cathode exhibited 94.65% NO3--N (nitrate-N) removal, 0.18% NO2--N (nitrite-N) generation, and 40.86% NH4--N (ammonia-N) generation with the assistance of Na2SO4 electrolyte in 6 h at 10 mA cm-2 and pH 6. Compared with the Cu/Ti cathode, the higher nitrate removal ratio and lower nitrite generation ratio were obtained on the Cu-Co/Ti cathode. The excellent performance of Cu-Co/Ti cathode is ascribed to the synergy of Cu and Co, which couples the facilitation of nitrate conversion to nitrite and the acceleration of nitrite reduction on the Cu-Co/Ti cathode. The LSV curves showed that nitrate and nitrite might undergo indirect and direct reduction reactions on Cu-Co/Ti cathode. The possible pathways of nitrate reduction on the Cu-Co/Ti cathodes were proposed. These results highlight the viability of using the Cu-Co/Ti cathode developed at this work for the nitrate removal from contaminated waters. This study achieved low-nitrite generation by Cu-Co/Ti cathode during electrochemical nitrate reduction.

Blue Light Exposure Caused Large-Scale Transcriptional Changes in the Abdomen and Reduced the Reproductive Fitness of the Fall Armyworm Spodoptera frugiperda.

In the present study, we found that blue light stress negatively affected the development periods, body weight, survival and reproduction of Spodoptera frugiperda, and it showed a dose-dependent reaction, as longer irradiation caused severer effects. Further transcriptome analysis found blue light stress induced fast and large-scale transcriptional changes in the head, thorax and, particularly, the abdomen of female S. frugiperda adults. A functional enrichment analysis indicated that shorter durations of blue light irradiation induced the upregulation of more stress response- and defense-related genes or pathways, such as abiotic stimuli detection and response, oxidative stress, ion channels and protein-kinase-based signal pathways. In the abdomen, however, different durations of blue-light-exposure treatments all induced the downregulation of a large number genes and pathways related to cellular processes, metabolism, catalysis and reproduction, which may be a trade-off between antistress defense and other processes or a strategy to escape stressful conditions. These results indicate irradiation duration- and tissue-specific blue light stress responses and consequences, as well as suggest that the stress that results in transcriptional alterations is associated with the stress that causes a fitness reduction in S. frugiperda females.

Li-doped calcium phosphate cement for accelerated bone regeneration of osteoporotic bone defect.

Osteoporotic fractures seriously endanger the elderly quality of life, especially postmenopausal women. Currently, calcium phosphate cement (CPC) is one of the materials used for the treatment of osteoporotic fractures. This study intends to investigate the biological effects of lithium (Li)-doped CPC. Li was dissolved into ultrapure water as curing solution to prepare CPC@Li composite material. Li did not affect the morphology of CPC. CPC@Li composite showed a sustained release of Li in 14 days. Compared with CPC, CPC@Li promoted the adhesion, proliferation, and osteogenic differentiation of rat bone marrow stem cells. The result of femur implantation in an osteoporosis mouse model showed that a larger amount of new bone was formed surrounding the CPC@Li implant and closely to the implant surface, indicating favorable osteogenesis and osteointegration capabilities. Li-doped CPC is promising to be used in clinic for its enhanced bone regeneration ability.

Electrochemical degradation of chloramphenicol using Ti-based SnO2-Sb-Ni electrode.

Antibiotic residues may be very harmful in aquatic environments, because of limited treatment efficiency of traditional treatment methods. An electrochemical system with a Ti-based SnO2-Sb-Ni anode was developed to degrade a typical antibiotic chloramphenicol (CAP) in water. The electrode was prepared using a sol-gel method. The performance of electrode materials, impact factors and dynamic characteristics were evaluated. The Ti-based SnO2-Sb-Ni electrode was compact and uniform as shown by characterization using SEM and XRD. The electrocatalytic oxidation of CAP was carried out in a single-chamber reactor by using a Ti-based SnO2-Sb-Ni electrode. For 100 mg L-1 CAP, the CAP removal ratio of 100% and the TOC removal ratio of 60% were obtained at the current density of 20 mA cm-2 and in a neutral electrolyte at 300 min. Kinetic investigation has shown that the electro-oxidation of CAP on a Ti-based SnO2-Sb-Ni electrode displayed a pseudo-first-order kinetic model. Free radical quenching experiments presented that the oxidation of CAP on Ti-based SnO2-Sb-Ni electrode resulted from the synergistic effect of direct oxidation and indirect oxidation (·OH and ·SO4-). Doping Ni on the Ti/SnO2-Sb electrode for CAP degradation was presented in this paper, showing its great application potential in the area of antibiotic and halogenated organic pollutant degradation.

Novel Bat Alphacoronaviruses in Southern China Support Chinese Horseshoe Bats as an Important Reservoir for Potential Novel Coronaviruses.

While bats are increasingly recognized as a source of coronavirus epidemics, the diversity and emergence potential of bat coronaviruses remains to be fully understood. Among 1779 bat samples collected in China, diverse coronaviruses were detected in 32 samples from five different bat species by RT-PCR. Two novel alphacoronaviruses, Rhinolophus sinicus bat coronavirus HKU32 (Rs-BatCoV HKU32) and Tylonycteris robustula bat coronavirus HKU33 (Tr-BatCoV HKU33), were discovered from Chinese horseshoe bats in Hong Kong and greater bamboo bats in Guizhou Province, respectively. Genome analyses showed that Rs-BatCoV HKU32 is closely related to BatCoV HKU10 and related viruses from diverse bat families, whereas Tr-BatCoV HKU33 is closely related to BtNv-AlphaCoV and similar viruses exclusively from bats of Vespertilionidae family. The close relatedness of Rs-BatCoV HKU32 to BatCoV HKU10 which was also detected in Pomona roundleaf bats from the same country park suggests that these viruses may have the tendency of infecting genetically distant bat populations of close geographical proximity with subsequent genetic divergence. Moreover, the presence of SARSr-CoV ORF7a-like protein in Rs-BatCoV HKU32 suggests a common evolutionary origin of this accessory protein with SARS-CoV, also from Chinese horseshoe bats, an apparent reservoir for coronavirus epidemics. The emergence potential of Rs-BatCoV HKU32 should be explored.