Fe-Fe Double-Atom Catalysts for Murine Coronavirus Disinfection: Nonradical Activation of Peroxides and Mechanisms of Virus Inactivation.

Peroxides find broad applications for disinfecting environmental pathogens particularly in the COVID-19 pandemic; however, the extensive use of chemical disinfectants can threaten human health and ecosystems. To achieve robust and sustainable disinfection with minimal adverse impacts, we developed Fe single-atom and Fe-Fe double-atom catalysts for activating peroxymonosulfate (PMS). The Fe-Fe double-atom catalyst supported on sulfur-doped graphitic carbon nitride outperformed other catalysts for oxidation, and it activated PMS likely through a nonradical route of catalyst-mediated electron transfer. This Fe-Fe double-atom catalyst enhanced PMS disinfection kinetics for inactivating murine coronaviruses (i.e., murine hepatitis virus strain A59 (MHV-A59)) by 2.17-4.60 times when compared to PMS treatment alone in diverse environmental media including simulated saliva and freshwater. The molecular-level mechanism of MHV-A59 inactivation was also elucidated. Fe-Fe double-atom catalysis promoted the damage of not only viral proteins and genomes but also internalization, a key step of virus lifecycle in host cells, for enhancing the potency of PMS disinfection. For the first time, our study advances double-atom catalysis for environmental pathogen control and provides fundamental insights of murine coronavirus disinfection. Our work paves a new avenue of leveraging advanced materials for improving disinfection, sanitation, and hygiene practices and protecting public health.

UltrasonicGS: A Highly Robust Gesture and Sign Language Recognition Method Based on Ultrasonic Signals.

With the global spread of the novel coronavirus, avoiding human-to-human contact has become an effective way to cut off the spread of the virus. Therefore, contactless gesture recognition becomes an effective means to reduce the risk of contact infection in outbreak prevention and control. However, the recognition of everyday behavioral sign language of a certain population of deaf people presents a challenge to sensing technology. Ubiquitous acoustics offer new ideas on how to perceive everyday behavior. The advantages of a low sampling rate, slow propagation speed, and easy access to the equipment have led to the widespread use of acoustic signal-based gesture recognition sensing technology. Therefore, this paper proposed a contactless gesture and sign language behavior sensing method based on ultrasonic signals-UltrasonicGS. The method used Generative Adversarial Network (GAN)-based data augmentation techniques to expand the dataset without human intervention and improve the performance of the behavior recognition model. In addition, to solve the problem of inconsistent length and difficult alignment of input and output sequences of continuous gestures and sign language gestures, we added the Connectionist Temporal Classification (CTC) algorithm after the CRNN network. Additionally, the architecture can achieve better recognition of sign language behaviors of certain people, filling the gap of acoustic-based perception of Chinese sign language. We have conducted extensive experiments and evaluations of UltrasonicGS in a variety of real scenarios. The experimental results showed that UltrasonicGS achieved a combined recognition rate of 98.8% for 15 single gestures and an average correct recognition rate of 92.4% and 86.3% for six sets of continuous gestures and sign language gestures, respectively. As a result, our proposed method provided a low-cost and highly robust solution for avoiding human-to-human contact.

Transformation of Graphitic Carbon Nitride by Reactive Chlorine Species: "Weak" Oxidants Are the Main Players.

Graphitic carbon nitride (g-C3N4) nanomaterials hold great promise in diverse applications; however, their stability in engineering systems and transformation in nature are largely underexplored. We evaluated the stability, aging, and environmental impact of g-C3N4 nanosheets under the attack of free chlorine and reactive chlorine species (RCS), a widely used oxidant/disinfectant and a class of ubiquitous radical species, respectively. g-C3N4 nanosheets were slowly oxidized by free chlorine even at a high concentration of 200-1200 mg L-1, but they decomposed rapidly when ClO· and/or Cl2•- were the key oxidants. Though Cl2•- and ClO· are considered weaker oxidants in previous studies due to their lower reduction potentials and slower reaction kinetics than ·OH and Cl·, our study highlighted that their electrophilic attack efficacy on g-C3N4 nanosheets was on par with ·OH and much higher than Cl·. A trace level of covalently bonded Cl (0.28-0.55 at%) was introduced to g-C3N4 nanosheets after free chlorine and RCS oxidation. Our study elucidates the environmental fate and transformation of g-C3N4 nanosheets, particularly under the oxidation of chlorine-containing species, and it also provides guidelines for designing reactive, robust, and safe nanomaterials for engineering applications.

Vesicle-Cloaked Rotavirus Clusters are Environmentally Persistent and Resistant to Free Chlorine Disinfection.

Recent discovery of vesicle-cloaked virus clusters (i.e., viral vesicles) has greatly challenged the central paradigm of viral transmission and infection as a single virion. To understand the environmental transmission of viral vesicles, we used an in vivo model to investigate their environmental persistence and engineering control by disinfection. Murine rotavirus vesicles maintained both their integrity and infectivity after incubation in filtered freshwater and wastewater for at least 7 days, with 24.5-27.5% of the vesicles still intact at 16 weeks after exposure to both waters. Free chlorine disinfection at a dosage of 13.3 mg min L-1 did not decompose murine rotavirus vesicles, and it was much less effective in inactivating rotaviruses inside vesicles than free rotaviruses based on the quantification of rotavirus shedding in mouse stool and rotavirus replication in small intestines. Rotavirus vesicles may be more environmentally transmissible than free rotaviruses regardless of disinfection. Vesicle-mediated en bloc transmission could be responsible for vesicles' resistance to disinfection due to an increased multiplicity of infection and/or genetic recombination or reassortment to promote infection. Our work highlights the environmental, biological, and public health significance of viral vesicles, and the findings call for urgent action in advancing disinfection for pathogen control.

Environmental application of chlorine-doped graphitic carbon nitride: Continuous solar-driven photocatalytic production of hydrogen peroxide.

Solar-driven photocatalytic generation of H2O2 over metal-free catalysts is a sustainable approach for value-added chemical production. Here, we synthesized chlorine-doped graphitic carbon nitride (Cl-doped g-C3N4) through a solvothermal method to effectively produce H2O2 with a rate of 1.19 ± 0.06 µM min-1 under visible light irradiation, which was improved by 104 times compared to pristine g-C3N4. Continuous net production of H2O2 was realized at a rate of 2.78 ± 0.10 µM min-1 up to 54 h with isopropanol as the hole scavenger, whereas H2O2 production was only sustained for ~ 6 h without scavengers. Both molecular simulations and advanced spectroscopic characterizations elucidated that the Cl dopant increased the charge transfer rate, decreased the bandgap, and reduced the activation energy of the rate-limiting step of O2 reduction, all of which favored H2O2 production. This work implemented a novel metal-free photocatalyst for sustainable H2O2 production and elucidated the mechanism for promoting H2O2 production that can guide future photoreactive nanomaterial design.

The Impact of Health Information Privacy Concerns on Engagement and Payment Behaviors in Online Health Communities.

Online health communities (OHCs) have enjoyed increasing popularity in recent years, especially in the context of the COVID-19 pandemic. However, several concerns have been raised regarding the privacy of users' personal information in OHCs. Considering that OHCs are a type of data-sharing or data-driven platform, it is crucial to determine whether users' health information privacy concerns influence their behaviors in OHCs. Thus, by conducting a survey, this study explores the impact of users' health information privacy concerns on their engagement and payment behavior (Paid) in OHCs. The empirical results show that users' concerns about health information privacy reduce their Paid in OHCs by negatively influencing their OHC engagement. Further analysis reveals that if users have higher benefit appraisals (i.e., perceived informational and emotional support from OHCs) and lower threat appraisals (i.e., perceived severity and vulnerability of information disclosure from OHCs), the negative effect of health information privacy concerns on users' OHC engagement will decrease.

The association between changes in multifidus muscle morphology and back pain scores following discectomy surgery for lumbar disc herniation: a systematic review and meta-analysis.

PURPOSE: To evaluate the impact of discectomy on back muscles (e.g. multifidus muscle (MM)) morphology in patients with lumbar disc herniation (LDH) following discectomy surgery, address the association of back muscles morphology with pain score preoperatively and post-operatively, and investigate the relationships between the changes from pre- to post-operative back muscles measurements and pain score (primary outcome) and disability score (secondary outcome) change following discectomy if any. METHODS: We searched three online databases for randomized controlled trials (RCTs) and observational studies. In LDH patients, eligible for discectomy surgery, pre- and post-operative and the changes from pre- to post-operative of back and/or leg pain with Visual Analogue Scale (VAS) and multifidus muscle morphology, were considered as primary outcomes. Cochrane Risk-of-Bias 2 tool and Newcastle-Ottawa Scale (NOS) were used to assess the methodological quality of RCTs and observational studies, respectively. Standardize mean difference (SMD) with 95% confidence intervals (CI) was evaluated. A meta-regression analysis was conducted. GRADE approach was used to summarize the strength of evidence. RESULTS: One RCT and five observational studies were included in the analysis of 489 patients with LDH undergoing discectomy surgery. The mean overall follow-up was 64.9 weeks (6 to 148.7 weeks). There was a significant negative relationship between the change from pre- to post-operative cross-sectional area (CSA) in MM and change in VAS back pain [regression coefficient = -0.01, (95% CI = -0.02, -0.01), p = 0.044] after discectomy surgery. No significant relationship between preoperative CSA in MM and preoperative/post-operative clinical (any of the follow-up periods) scores could be established. CONCLUSION: The results of this study found very low-quality grade evidence for an association between higher reduction of CSA in MM and less reductions of back pain scores following discectomy surgery for patients with LDH. Due to the heterogeneity and methodological limitations, further studies will improve understanding and aid preoperative counselling.

Radical-Driven Decomposition of Graphitic Carbon Nitride Nanosheets: Light Exposure Matters.

Understanding the transformation of graphitic carbon nitride (g-C3N4) is essential to assess nanomaterial robustness and environmental risks. Using an integrated experimental and simulation approach, our work has demonstrated that the photoinduced hole (h+) on g-C3N4 nanosheets significantly enhances nanomaterial decomposition under •OH attack. Two g-C3N4 nanosheet samples D and M2 were synthesized, among which M2 had more pores, defects, and edges, and they were subjected to treatments with •OH alone and both •OH and h+. Both D and M2 were oxidized and released nitrate and soluble organic fragments, and M2 was more susceptible to oxidation. Particularly, h+ increased the nitrate release rate by 3.37-6.33 times even though the steady-state concentration of •OH was similar. Molecular simulations highlighted that •OH only attacked a limited number of edge-site heptazines on g-C3N4 nanosheets and resulted in peripheral etching and slow degradation, whereas h+ decreased the activation energy barrier of C-N bond breaking between heptazines, shifted the degradation pathway to bulk fragmentation, and thus led to much faster degradation. This discovery not only sheds light on the unique environmental transformation of emerging photoreactive nanomaterials but also provides guidelines for designing robust nanomaterials for engineering applications.

Continuous photocatalysis via photo-charging and dark-discharging for sustainable environmental remediation: Performance, mechanism, and influencing factors.

Continuous photocatalysis via photo-charging and dark-discharging presents a paradigm shift in conventional photocatalysis with the requirement of continuous illumination to maintain the catalytic activity. This is expected to meet the ever-increasing demand for sustainable development of energy and environment driven by natural day-night cycles. Substantial advances in continuous photocatalysis for various environmental applications under light-dark cycles have been witnessed during the last decade. However, there lacks a systematic and critical review on basic but important information of continuous photocatalysis for environmental remediation, challenging robust scientific progress of this technology towards potential practical use. Here, the general description of continuous photocatalysis involving energy storage mechanisms (hole and electron storage) and characterizations (electron storage behaviors, release behaviors and storage capacity) has been first introduced. Importantly, the remediation performance and mechanism of continuous photocatalysis for environmental applications are qualitatively and quantitatively demonstrated, including chemical pollutant oxidation and reduction, microbial pathogen inactivation, and multifunctional treatment. In addition, key factors influencing its remediation performance are analyzed, for the first time, from both operational and environmental views. The ample opportunities in the field of continuous photocatalysis for sustainable environmental remediation are also pointed out, calling for more efforts to fill current knowledge gaps in the future.

Fe-based single-atom catalysis for oxidizing contaminants of emerging concern by activating peroxides.

We prepared a single-atom Fe catalyst supported on an oxygen-doped, nitrogen-rich carbon support (SAFe-OCN) for degrading a broad spectrum of contaminants of emerging concern (CECs) by activating peroxides such as peroxymonosulfate (PMS). In the SAFe-OCN/PMS system, most selected CECs were amenable to degradation and high-valent Fe species were present for oxidation. Moreover, SAFe-OCN showed excellent performance for contaminant degradation in complex water matrices and high stability in oxidation. Specifically, SAFe-OCN, with a catalytic center of Fe coordinated with both nitrogen and oxygen (FeNxO4-x), showed 5.13-times increased phenol degradation kinetics upon activating PMS compared to the catalyst where Fe was only coordinated with nitrogen (FeN4). Molecular simulations suggested that FeNxO4-x, compared to FeN4, was an excellent multiple-electron donor and it could potential-readily form high-valent Fe species upon oxidation. In summary, the single-atom Fe catalyst enables efficient, robust, and sustainable water and wastewater treatment, and molecular simulations highlight that the electronic nature of Fe could play a key role in determining the activity of the single-atom catalyst.

Novel Trypanocidal Inhibitors that Block Glycosome Biogenesis by Targeting PEX3-PEX19 Interaction.

Human pathogenic trypanosomatid parasites harbor a unique form of peroxisomes termed glycosomes that are essential for parasite viability. We and others previously identified and characterized the essential Trypanosoma brucei ortholog TbPEX3, which is the membrane-docking factor for the cytosolic receptor PEX19 bound to the glycosomal membrane proteins. Knockdown of TbPEX3 expression leads to mislocalization of glycosomal membrane and matrix proteins, and subsequent cell death. As an early step in glycosome biogenesis, the PEX3-PEX19 interaction is an attractive drug target. We established a high-throughput assay for TbPEX3-TbPEX19 interaction and screened a compound library for small-molecule inhibitors. Hits from the screen were further validated using an in vitro ELISA assay. We identified three compounds, which exhibit significant trypanocidal activity but show no apparent toxicity to human cells. Furthermore, we show that these compounds lead to mislocalization of glycosomal proteins, which is toxic to the trypanosomes. Moreover, NMR-based experiments indicate that the inhibitors bind to PEX3. The inhibitors interfering with glycosomal biogenesis by targeting the TbPEX3-TbPEX19 interaction serve as starting points for further optimization and anti-trypanosomal drug development.

Evolutionary divergent PEX3 is essential for glycosome biogenesis and survival of trypanosomatid parasites.

Trypanosomatid parasites cause devastating African sleeping sickness, Chagas disease, and Leishmaniasis that affect about 18 million people worldwide. Recently, we showed that the biogenesis of glycosomes could be the "Achilles' heel" of trypanosomatids suitable for the development of new therapies against trypanosomiases. This was shown for inhibitors of the import machinery of matrix proteins, while the distinct machinery for the topogenesis of glycosomal membrane proteins evaded investigation due to the lack of a druggable interface. Here we report on the identification of the highly divergent trypanosomal PEX3, a central component of the transport machinery of peroxisomal membrane proteins and the master regulator of peroxisome biogenesis. The trypanosomatid PEX3 shows very low degree of conservation and its identification was made possible by a combinatory approach identifying of PEX19-interacting proteins and secondary structure homology screening. The trypanosomal PEX3 localizes to glycosomes and directly interacts with the membrane protein import receptor PEX19. RNAi-studies revealed that the PEX3 is essential and that its depletion results in mislocalization of glycosomal proteins to the cytosol and a severe growth defect. Comparison of the parasites and human PEX3-PEX19 interface disclosed differences that might be accessible for drug development. The absolute requirement for biogenesis of glycosomes and its structural distinction from its human counterpart make PEX3 a prime drug target for the development of novel therapies against trypanosomiases. The identification paves the way for future drug development targeting PEX3, and for the analysis of additional partners involved in this crucial step of glycosome biogenesis.

Shrimp TAB1 interacts with TAK1 and p38 and activates the host innate immune response to bacterial infection.

Mammalian TAB1 has been previously identified as transforming growth factor-ß (TGF-ß)-activated kinase 1 (TAK1) binding protein, which functions as the activator of TAK1 and p38. This report, for the first time, identified and characterized the homolog of TAB1 in shrimp, to be specific, the homolog gene from Litopenaeus vannamei, containing a 1560-bp open reading frame (ORF) that encoded a putative protein of 519 amino acids with the conserved PP2Cc (Serine/threonine phosphatases, family 2C, catalytic) domain in N-terminal and a TAK1 binding motif in C-terminus, has been cloned and named LvTAB1. LvTAB1 was most abundant in gills and its expression could respond significantly to a series of stimuli, including LPS, Vibrio parahemolyticus and Staphylococcus aureus. Moreover, Co-immunoprecipitation (Co-IP) experiments showed that LvTAB1 could combine with LvTAK1 as well as Lvp38, two members of IMD-NF-κB/MAPK pathway, which meant LvTAB1 could have a role in regulating the activities of these kinases. Over-expression of LvTAB1 in drosophila S2 cells could improve the transcriptional levels of antimicrobial peptide genes (AMPs) such as Diptericin (Dpt), the hallmark of drosophila NF-κB activated genes, indicating its activation effect on NF-κB pathway. Furthermore, suppression of LvTAB1 expression in vivo by RNA-interference increased the sensibility of shrimps to V. parahaemolyticus infection, implying its protective role against bacterial infection. In conclusion, these results provide some insight into the function of LvTAB1 during bacterial infection.

Defective Tungsten Oxide Hydrate Nanosheets for Boosting Aerobic Coupling of Amines: Synergistic Catalysis by Oxygen Vacancies and Brønsted Acid Sites.

Adsorption and activation of molecules on a surface holds the key to heterogeneous catalysis toward aerobic oxidative reactions. To achieve high catalytic activities, a catalyst surface should be rationally tailored to interact with both organic substrates and oxygen molecules. Here, a facile bottom-up approach to defective tungsten oxide hydrate (WO3 ·H2 O) nanosheets that contain both surface defects and lattice water is reported. The defective WO3 ·H2 O nanosheets exhibit excellent catalytic activity for aerobic coupling of amines to imines. The investigation indicates that the oxygen vacancies derived from surface defects supply coordinatively unsaturated sites to adsorb and activate oxygen molecules, producing superoxide radicals. More importantly, the Brønsted acid sites from lattice water can contribute to enhancing the adsorption and activation of alkaline amine molecules. The synergistic effect of oxygen vacancies and Brønsted acid sites eventually boosts the catalytic activity, which achieves a kinetic rate constant of 0.455 h-1 and a turnover frequency of 0.85 h-1 at 2 h, with the activation energy reduced to ≈35 kJ mol-1 . This work provides a different angle for metal oxide catalyst design by maneuvering subtle structural features, and highlights the importance of synergistic effects to heterogeneous catalysts.

PdPt Alloy Nanocatalysts Supported on TiO2 : Maneuvering Metal-Hydrogen Interactions for Light-Driven and Water-Donating Selective Alkyne Semihydrogenation.

Low power consumption and minimal potential hazards are ultimate goals for the modern development of chemical manufacturing; however, it often reduces the selectivity of chemical reactions by implementing a new reaction system. A nanocatalyst design is reported for achieving efficient and selective alkyne semihydrogenation through the photocatalytic hydrogen transfer from water, which avoids the use of a heat source and explosive H2 . The PdPt catalytic sites that are implemented on the TiO2 photocatalyst hold the key to achieving both high activity and selectivity. As compared with pure Pd or Pt, the alloy cocatalysts can better harness H diffusion/desorption for selective semihydrogenation as well as suppress competitive H2 evolution. This work opens up new possibilities for green and selective alkyne semihydrogenation and highlights the importance of lattice engineering to catalytic selectivity.

Changing Ce3+ Content and Codoping Mn2+ Induced Tunable Emission and Energy Transfer in Ca2.5Sr0.5Al2O6:Ce3+,Mn2.

A series of color-tunable Ce3+ single-doped and Ce3+, Mn2+ codoped Ca2.5Sr0.5Al2O6 phosphors were synthesized by a high-temperature solid-state reaction. The crystal structure, luminescent properties, and energy transfer were studied. For Ca2.5Sr0.5Al2O6:Ce3+ phosphors obtained with Al(OH)3 as the raw material, three emission profiles were observed. The peak of photoluminescence (PL) spectra excited at ∼360 nm shifts from 470 to 420 nm, while that of the PL spectra excited at 305 nm stays unchanged at 470 nm with the increase of Ce3+ content. Furthermore, the peak of PL spectra is situated at 500 nm under excitation at ∼400 nm. The relationship between the luminescent properties and crystal structure was studied in detail. Ce3+, Mn2+ codoped Ca2.5Sr0.5Al2O6 phosphors also showed interesting luminescent properties when focused on the PL spectra excited at 365 nm. Obvious different decreasing trends of blue and cyan emission components were observed in Ca2.5Sr0.5Al2O6:0.11Ce3+,xMn2+ phosphors with the increase in Mn2+ content, suggesting different energy transfer efficiencies from blue- and cyan-emitting Ce3+ to Mn2+. Phosphors with high color-rendering index (CRI) values are realized by adjusting the doping content of both Ce3+ and Mn2+. Studies suggest that the Ca2.5Sr0.5Al2O6:Ce3+,Mn2+ phosphor is a promising candidate for near UV-excited w-LEDs.