A functional study reveals CsNAC086 regulated the biosynthesis of flavonols in Camellia sinensis.

MAIN CONCLUSION: CsNAC086 was found to promote the expression of CsFLS, thus promoting the accumulation of flavonols in Camellia sinensis. Flavonols, the main flavonoids in tea plants, play an important role in the taste and quality of tea. In this study, a NAC TF gene CsNAC086 was isolated from tea plants and confirmed its regulatory role in the expression of flavonol synthase which is a key gene involved in the biosynthesis of flavonols in tea plant. Yeast transcription-activity assays showed that CsNAC086 has self-activation activity. The transcriptional activator domain of CsNAC086 is located in the non-conserved C-terminal region (positions 171-550), while the conserved NAC domain (positions 1-170) does not have self-activation activity. Silencing the CsNAC086 gene using antisense oligonucleotides significantly decreased the expression of CsFLS. As a result, the concentration of flavonols decreased significantly. In overexpressing CsNAC086 tobacco leaves, the expression of NtFLS was significantly increased. Compared with wild-type tobacco, the flavonols concentration increased. Yeast one-hybrid assays showed CsNAC086 did not directly regulate the gene expression of CsFLS. These findings indicate that CsNAC086 plays a role in regulating flavonols biosynthesis in tea plants, which has important implications for selecting and breeding of high-flavonols-concentration containing tea-plant cultivars.

Characterization of humoral immune responses against SARS-CoV-2 accessory proteins in infected patients and mouse model.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, encodes several accessory proteins that have been shown to play crucial roles in regulating the innate immune response. However, their expressions in infected cells and immunogenicity in infected humans and mice are still not fully understood. In this study, we detected accessory protein-specific antibodies in COVID-19 patients' sera using various techniques, including Luciferase Immunoprecipitation System (LIPS), Immunofluorescence assay (IFA), and Western blot (WB). Proteins 3a, 3b, 7b, 8 and 9c specific antibodies can be detected by LIPS, but only protein 3a antibody was detected by IFA or WB. And antibodies against protein 3a and 7b only detected in ICU patients, which may serve as a marker for predicting the disease progression. Further, we investigated the expression of accessory proteins in SARS-CoV-2-infected cells and identified the expressions of proteins 3a, 6, 7a, 8, and 9b. We also analyzed their ability to induce antibodies in immunized mice and found that only proteins 3a, 6, 7a, 8, 9b and 9c were able to induce measurable antibody productions, but these antibodies lacked neutralizing activities and did not protect mice from SARS-CoV-2 infection. Our findings validate the expression of SARS-CoV-2 accessory proteins and elucidate their humoral immune response, providing a basis for the protein detection assays and their role in pathogenesis.

[Components Characteristic and Source Apportionment of Fine Particulate Matter in Transition Period of Heating Season in Xi'an with High Time Resolution].

Influenced by heating, the concentration of atmospheric fine particulate matter (PM2.5) rises in autumn and winter in northern cities. In this study, Q-ACSM, AE33, and Xact 625 were used to carry out online monitoring of PM2.5 chemical components with high time resolution in Xi'an from October 25 to November 17, 2019, to analyze the characteristics of PM2.5 pollution during the transition period of the heating season. Additionally, we analyzed the sources of PM2.5 in combination with the positive matrix factorization model. The results showed that the average PM2.5 concentration during the observation period was (78.3 ± 38.5) µg·m-3, and the main chemical components were organic matter (OA), secondary inorganic ions (SIA), and dust, which accounted for 38.7%, 31.6%, and 21.2%, respectively. The average concentrations of sulfate, nitrate, and ammonium were (4.0 ± 3.1), (14.9 ± 13.7), and (5.8 ± 4.8) µg·m-3, and the average concentrations of the major metals potassium, calcium, and iron were (1.0 ± 0.4), (1.5 ± 1.1), and (1.4 ± 0.9) µg·m-3. Black carbon, chloride ions, and trace elements contributed relatively little to PM2.5 (5.7%, 1.3%, and 1.5%, respectively). In the pollution development and maintenance stage, the concentration of OA and SIA increased by 137.7% to 537.0%, whereas in the pollution dissipation stage, only the concentration of dust gradually increased. The source apportionment results showed that secondary sources, biomass burning, dust, vehicle emission, industrial emission, and coal combustion were the main sources of PM2.5 during the observation period, contributing 29.1%, 21.1%, 15.3%, 12.9%, 11.4%, and 10.2%, respectively. The contribution rate of secondary sources and biomass burning was higher in the pollution development and maintenance stage, and dust was higher in the pollution dissipation stage.

A Method to Develop the Driver-Adaptive Lane-Keeping Assistance System Based on Real Driver Preferences.

To satisfy the preference of each driver, the development of a Lane-Keeping Assistance (LKA) system that can adapt to individual drivers has become a research hotspot in recent years. However, existing studies have mostly relied on the assumption that the LKA characteristic aligned with the driver's preference is consistent with this driver's naturalistic driving characteristic. Nevertheless, this assumption may not always hold true, causing limitations to the effectiveness of this method. This paper proposes a novel method for a Driver-Adaptive Lane-Keeping Assistance (DALKA) system based on drivers' real preferences. First, metrics are extracted from collected naturalistic driving data using action point theory to describe drivers' naturalistic driving characteristics. Then, the subjective and objective evaluation method is introduced to obtain the real preference of each test driver for the LKA system. Finally, machine learning methods are employed to train a model that relates naturalistic driving characteristics to the drivers' real preferences, and the model-predicted preferences are integrated into the DALKA system. The developed DALKA system is then subjectively evaluated by the drivers. The results show that our DALKA system, developed using this method, can enhance or maintain the subjective evaluations of the LKA system for most drivers.

Critical Review of Pd-Catalyzed Reduction Process for Treatment of Waterborne Pollutants.

Catalyzed reduction processes have been recognized as important and supplementary technologies for water treatment, with the specific aims of resource recovery, enhancement of bio/chemical-treatability of persistent organic pollutants, and safe handling of oxygenate ions. Palladium (Pd) has been widely used as a catalyst/electrocatalyst in these reduction processes. However, due to the limited reserves and high cost of Pd, it is essential to gain a better understanding of the Pd-catalyzed decontamination process to design affordable and sustainable Pd catalysts. This review provides a systematic summary of recent advances in understanding Pd-catalyzed reductive decontamination processes and designing Pd-based nanocatalysts for the reductive treatment of water-borne pollutants, with special focus on the interactions and transformation mechanisms of pollutant molecules on Pd catalysts at the atomic scale. The discussion begins by examining the adsorption of pollutants onto Pd sites from a thermodynamic viewpoint. This is followed by an explanation of the molecular-level reaction mechanism, demonstrating how electron-donors participate in the reductive transformation of pollutants. Next, the influence of the Pd reactive site structure on catalytic performance is explored. Additionally, the process of Pd-catalyzed reduction in facilitating the oxidation of pollutants is briefly discussed. The longevity of Pd catalysts, a crucial factor in determining their practicality, is also examined. Finally, we argue for increased attention to mechanism study, as well as precise construction of Pd sites under batch synthesis conditions, and the use of Pd-based catalysts/electrocatalysts in the treatment of concentrated pollutants to facilitate resource recovery.

Climate change may drive the distribution of tribe Zyginelline pests in China and the Indo-China Peninsula to shift towards higher latitude river-mountain systems.

BACKGROUND: Tribe Zyginelline leafhoppers can transmit plant viruses and are important pests that affect agriculture, forestry, and animal husbandry, causing serious economic losses. The potential distribution patterns of Zyginellini will change under climate change. Therefore, the best-performing random forest and maximum entropy models among 12 commonly used ecological niche models, alongside an ensemble model, were selected to predict the changes in habitat suitability distribution of Zyginellini under current and future climate scenarios [represented by two shared socio-economic pathways (SSPs), namely SSP126 and SSP585, for three periods (2050s, 2070s, and 2090s)] in China and the Indo-China Peninsula for the first time. RESULTS: The results revealed that the distribution of Zyginellini was mainly dominated by minimum temperature of coldest month. Under current and future climate scenarios, Zyginellini was mostly distributed southeast of the 400 mm equivalent precipitation line in China, and Vietnam. Under the future SSP126 scenario, the alert areas will mainly be concentrated in Hunan, Jiangxi, Zhejiang, Anhui, and Hebei in China, alongside Myanmar and Thailand in the Indo-China Peninsula. Meanwhile, in the SSP585 scenario, the alert areas in China will increase, whereas there will be little change in the Indo-China Peninsula. Interestingly, from the current to the future, the cores of Zyginelline distribution occurred around rivers and mountains, and shifted from Guizhou along the Yuanjiang River system to higher latitudes in Hunan. CONCLUSION: Zyginellini prefers higher latitude river-mountain systems under climate change. Our results will contribute to effective pest control strategies and biogeographical research for Zyginellini alongside other Cicadellidae insects. © 2023 Society of Chemical Industry.

Clinical Effect of Ultrasound-Guided Adductor Block on Postoperative Analgesia After Total Knee Replacement.

Objective: To explore the clinical effects of ultrasound-guided adductor block (UGAB) on postoperative analgesia after total knee replacement. Methods: From March 2022 to June 2022, 60 patients in the First Affiliated Hospital of Chongqing Medical University were included. They were divided into control (n = 30) and ultrasonic groups (n = 30). They all received total knee arthroplasty. Before total knee arthroplasty, patients in the control and ultrasonic groups underwent general anesthesia and UGAB, respectively. Visual Analogue Scale (VAS) was used to assess the pain. The time of the first straight leg elevation and the first landing time were recorded. Knee joint function was evaluated. Information about the dosage of tramadol intramuscular injection and the number of times patient-controlled analgesia pump pressing was collected. The serum levels of interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were detected. Results: Compared with the control group, UGAB increased the rate of muscle contraction and relaxation and total and relaxation after total knee replacement in the ultrasonic group (P < .05). UGAB reduced VAS scores of pain during passive activity after operation (P < .05). UGAB also facilitated the first straight leg lifting time after the operation and the time of the first landing after the operation (P < .05). Meanwhile, UGAB reduced the dose of tramadol and press times of the self-control analgesia pump after operation (P < 0.05). UGAB also suppressed postoperative IL-6 and hs-CRP levels and increased postoperative joint range of motion (P < .05). Conclusion: UGAB promotes early recovery of knee function with high safety in patients undergoing total knee replacement, with reduced postoperative pain and inflammatory reaction.

Mosaic RBD Nanoparticles Elicit Protective Immunity Against Multiple Human Coronaviruses in Animal Models.

To combat SARS-CoV-2 variants and MERS-CoV, as well as the potential re-emergence of SARS-CoV and spillovers of sarbecoviruses, which pose a significant threat to global public health, vaccines that can confer broad-spectrum protection against betacoronaviruses (ß-CoVs) are urgently needed. A mosaic ferritin nanoparticle vaccine is developed that co-displays the spike receptor-binding domains of SARS-CoV, MERS-CoV, and SARS-CoV-2 Wild-type (WT) strain and evaluated its immunogenicity and protective efficacy in mice and nonhuman primates. A low dose of 10 µg administered at a 21-day interval induced a Th1-biased immune response in mice and elicited robust cross-reactive neutralizing antibody responses against a variety of ß-CoVs, including a series of SARS-CoV-2 variants. It is also able to effectively protect against challenges of SARS-CoV, MERS-CoV, and SARS-CoV-2 variants in not only young mice but also the more vulnerable mice through induction of long-lived immunity. Together, these results suggest that this mosaic 3-RBD nanoparticle has the potential to be developed as a pan-ß-CoV vaccine.

Can Ultrasound-Guided Continuous Paravertebral Block Reduce the Incidence of Chronic Postsurgical Pain in Patients with Thoracoscopic Lung Cancer Surgery? A Randomized Controlled Trial.

Background: Thoracoscopic lung cancer surgery is accompanied by severe pain. Both continuous paravertebral block (CPVB) and continuous wound infiltration (CWI) are widely used for perioperative analgesia in thoracoscopic surgery. However, the effects of these different methods on chronic postsurgical pain (CPSP) are still unknown. Patients and Methods. This prospective randomized controlled trial assessed the eligibility of 113 patients. Ninety-seven patients who met the inclusion criteria were randomly divided into a CPVB group and a CWI group, and 80 patients were analyzed in the final study. The primary outcome measures were the incidence and intensity of chronic postsurgical pain (CPSP) at 3, 6, and 9 months after surgery. The secondary outcome measures were the numerical rating scale (NRS) score of rest and activity at 12, 18, and 24 hours and on the 2nd, 3rd, and 7th days postoperatively; the Barthel Activities of Daily Living (ADL) score of activity levels on the 1st, 2nd, 3rd, and 7th days postoperatively; and the long-term quality of the life score at 3, 6, and 9 months postoperatively. Results: The incidence of chronic postsurgical pain in the CWI group was significantly higher than that in the CPVB group at 3, 6, and 9 months after surgery (all P < 0.05). The intensity of chronic postsurgical pain was significantly decreased in the CPVB group at 3, 6, and 9 months after surgery (P < 0.05). NRS-R and NRS-A scores were significantly decreased in the CPVB group within the first week after thoracoscopic surgery (P < 0.001). ADL scores were increased in the CPVB group within 3 days postoperatively. However, there were no differences in the ADL score on the 7th postoperative day or the long-term quality of the life score at 3, 6, and 9 months postoperatively. Conclusion: Continuous ultrasound-guided paravertebral block reduced the intensity of acute pain within 7 days postoperatively and reduced the incidence of chronic pain at 3, 6, and 9 months after surgery, but there was no significant advantage in long-term quality of life. This trial is registered with ChiCTR2000038505.

First-principle study of shear deformation effect on Mg adsorption by monolayer SnS2.

CONTEXT: In this study, the effects of different shear deformations on the structural stability, electronic structure, and optical properties of a Mg atom adsorption system of S vacancy defect SnS2 are systematically investigated based on density functional theory. It is shown that the presence of an S-vacancy defect makes the band gap of the SnS2 system significantly smaller than that of the perfect SnS2 system, and the SnS2 system is changed from a direct band gap semiconductor to an indirect band gap semiconductor. The optimal adsorption position of a Mg atom on the S-vacancy SnS2 system is above the S atom where the adsorption energy is the largest and the system is the most stable. The density of states of the adsorption system is predominantly contributed by the S-3p and Sn-5 s orbital electrons. The imposition of shear deformation leads to the introduction of certain impurity energy levels in the adsorption system, and the forbidden bandwidth near the Fermi energy level decreases. As compared to the intrinsic SnS2, the absorption and reflection peaks of adsorption systems under different shear deformation are red-shifted and appear in the ultraviolet region. This improves the utilization of the adsorption system for ultraviolet light to a great extent. METHODS: The model calculations in this paper are performed using the CASTEP module of the Material Studio (MS) software based on the first principles of Density Functional Theory (DFT) (Wei et al. in Physica B 545:99-106, 2018) for plane wave artifacts. Geometrical optimization and computational procedures are used to calculate the exchange-correlation energy using the Perdew-Burke-Ernzerhof (PBE) generalized function (Perdew et al. in Phys Rev B Condens Matter 48:4978, 1993) of the generalized gradient approximation (GGA). The Monkhorst-Pack method (Monkhorst and Pack in Phys Rev B 13:5188-5192, 1976) was used to rationalize the sampling of the highly symmetric k-points in the Brillouin zone. The grid of k-points is set to be 6 × 6 × 1. The plane-wave truncation energy is set to be 400 eV. The energy convergence criterion is 1.0 × 10-5 eV. The residual stress of all atoms is 0.01 eV/Å. A vacuum layer with a thickness of 15 Å is set up in the z-direction, which ensures that the interactions of the system along the z-axis between the top and the bottom layers can be ignored during the whole simulation process. We construct a 3 × 3 × 1 SnS2 system containing 27 atoms as the computational model. The intrinsic SnS2 contains 9 Sn atoms and 18 S atoms.

A Naïve Phage Display Library-Derived Nanobody Neutralizes SARS-CoV-2 and Three Variants of Concern.

Background: The emergence of the coronavirus disease 2019 (COVID-19) pandemic and the new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants of concern (VOCs) requires the continuous development of safe, effective, and affordable prevention and therapeutics. Nanobodies have demonstrated antiviral activity against a variety of viruses, providing a new candidate for the prevention and treatment of SARS-CoV-2 and its variants. Methods: SARS-CoV-2 glycoprotein spike 1 subunit (S1) was selected as the target antigen for nanobody screening of a naïve phage display library. We obtained a nanobody, named Nb-H6, and then determined its affinity, inhibition, and stability by ELISA, Competitive ELISA, and Biolayer Interferometry (BLI). Infection assays of authentic and pseudotyped SARS-CoV-2 were performed to evaluate the neutralization of Nb-H6. The structure and mechanism of action were investigated by AlphaFold, docking, and residue mutation assays. Results: We isolated and characterized a nanobody, Nb-H6, which exhibits a broad affinity for S1 and the receptor binding domain (RBD) of SARS-CoV-2, or Alpha (B.1.1.7), Delta (B.1.617.2), Lambda (C.37), and Omicron (BA.2 and BA.5), and blocks receptor angiotensin-converting enzyme 2 (ACE2) binding. Moreover, Nb-H6 can retain its binding capability after pH or thermal treatment and effectively neutralize both pseudotyped and authentic SARS-CoV-2, as well as VOC Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron (BA.2 and BA.5) pseudoviruses. We also confirmed that Nb-H6 binds two distinct amino acid residues of the RBD, preventing SARS-CoV-2 from interacting with the host receptor. Conclusion: Our study highlights a novel nanobody, Nb-H6, that may be useful therapeutically in SARS-CoV-2 and VOC outbreaks and pandemics. These findings also provide a molecular foundation for further studies into how nanobodies neutralize SARS-CoV-2 and variants and imply potential therapeutic targets for the treatment of COVID-19.

Establishment and evaluation of a multiplex real-time RT-PCR for quantitative and differential detection of wild-type canine distemper virus from vaccine strains.

This study sought to establish a real-time reverse transcription (RT)-PCR method to differentially detect canine distemper virus (CDV) wild-type and vaccine strains. To this end, a pair of CDV universal primers and two specific minor groove binder (MGB) probes, harboring a T/C substitution in the hemagglutinin (H) gene, were designed. Using a recombinant plasmid expressing the H gene of the CDV wild-type or vaccine strain as standards, a sensitive and specific multiplex real-time RT-PCR was established for quantitative and differential detection of CDV wild-type and vaccine strains. The limit of detection for this multiplex assay was 22.5 copies/µL and 2.98 copies/µL of viral RNA for wild-type and vaccine strains, respectively. Importantly, the wild-type and vaccine MGB probes specifically hybridized different genotypes of wild-type CDV circulating in China as well as globally administered vaccine viruses, respectively, with no cross-reactivity observed with non-CDV viruses. Moreover, this method was successfully applied for the quantitative detection of CDV RNA in tissue samples of experimentally infected breeding foxes, raccoon dogs, and minks. Additionally, the multiplex real-time RT-PCR was able to detect the viral RNA in the whole blood samples as early as 3 days post-infection, 3 to 4 days prior to the onset of clinical signs in these CDV infection animals. Hence, the established multiplex real-time RT-PCR method is useful for differentiating wild-type CDV and vaccine strains in China, and for conducting canine distemper early diagnosis as well as dynamic mechanism of CDV replication studies in vivo.

Suppressing gas swelling in self-assembled Li4Ti5O12 (400) for high-performance rechargeable batteries.

Lithium titanate is a promising anode material for lithium-ion batteries due to its high-rate capability and long-cycle duration. However, gas swelling during electrochemical reactions has hindered its industrial application. Here, we synthesize self-assembled (400)-orientation lithium titanate (SA-LTONF) with ultrafine nanoparticles using a feasible thermal method. The SA-LTONF with an organic carbon coating exhibited superior electrochemical performance. To understand such high-rate capability, we perform density functional theory (DFT) calculations which elucidate the orientation-dependent electrochemical mechanism of hydrogen evolution and the atomically dynamic mechanism of lithium-ion migration in Li4Ti5O12 and Li7Ti5O12. Our findings provide a unique insight into the gas generation and ultrafast lithium-ion transportation in lithium titanate and offer guidance for nanoarchitecture construction and materials design of lithium titanate for commercial applications.

Online Personalized Preference Learning Method Based on In-Formative Query for Lane Centering Control Trajectory.

The personalization of autonomous vehicles or advanced driver assistance systems has been a widely researched topic, with many proposals aiming to achieve human-like or driver-imitating methods. However, these approaches rely on an implicit assumption that all drivers prefer the vehicle to drive like themselves, which may not hold true for all drivers. To address this issue, this study proposes an online personalized preference learning method (OPPLM) that utilizes a pairwise comparison group preference query and the Bayesian approach. The proposed OPPLM adopts a two-layer hierarchical structure model based on utility theory to represent driver preferences on the trajectory. To improve the accuracy of learning, the uncertainty of driver query answers is modeled. In addition, informative query and greedy query selection methods are used to improve learning speed. To determine when the driver's preferred trajectory has been found, a convergence criterion is proposed. To evaluate the effectiveness of the OPPLM, a user study is conducted to learn the driver's preferred trajectory in the curve of the lane centering control (LCC) system. The results show that the OPPLM can converge quickly, requiring only about 11 queries on average. Moreover, it accurately learned the driver's favorite trajectory, and the estimated utility of the driver preference model is highly consistent with the subject evaluation score.

Early oral nutritional supplement improves COVID-19 outcomes among hospitalized older patients during the Omicron wave.

OBJECTIVES: The effect of and optimal timing for initiating an oral nutritional supplement(ONS) in hospitalized older patients with the Omicron variant infection remain unclear. The aim of this study was to explore the associations between the ONS and clinical outcomes. METHODS: This study used a retrospective cohort design as primary analysis and a case-control design as sensitivity analysis. We collected data from patients with confirmed coronavirus disease 2019 (COVID-19) between April 2022 and June 2022 at Shanghai Fourth People's Hospital, one of the designated medical centers for COVID-19 in Shanghai, China. Patients were identified as ONS users or non-ONS users, with the former defined as early ONS (ONS initiated within 48 h from hospital admission), and late ONS (ONS initiated after 48 h) users. RESULTS: The study included 1181 hospitalized patients ≥60 y of age. The mean age of the cohort was 78 y, and most patients were women (57.7%). Mortalities after propensity-score matching were 1.2% and 4.3% in the ONS group and non-ONS groups, respectively (P = 0.032). Subgroup analysis results showed that median (IQR) hospital length of stay and the median (IQR) length from symptom onset to viral clearance were shorter for the early ONS than for the late ONS group (9 [6-13] d versus 14 [11 -18] d; P < 0.001, and 11 [8-17] d versus 17 [13-22] d; P < 0.001, respectively). The findings from the case-control analysis supported those from the primary analysis. CONCLUSIONS: Early ONS might have significantly lowered risk for in-hospital death, as well as reduce hospital length of stay and days of viral clearance in older patients with COVID-19 during the Omicron wave.

Fabrication of a tellurite-fiber-based side-pump coupler based on the tapered-fused method.

In this study, (1 + 1) × 1 side-pump couplers made of tellurite fibers were fabricated and investigated. The whole optical design of the coupler was established on the basis of ray tracing models and validated by experimental results. By optimizing the preparation conditions and structural parameters, the tested component achieved a coupling efficiency of 67.52% and an insertion loss of 0.52 dB. To the best of our knowledge, this is the first time a tellurite-fiber-based side-pump coupler was developed. The fused coupler presented will simplify many mid-infrared fiber lasers or amplifier architectures.

Case report: Successful treatment of mediastinal unicentric castleman disease using cardiopulmonary bypass.

Unicentric Castleman disease (UCD) is a rare, benign lymphoproliferative disorder. Mediastinal UCD has tumors with no clear boundaries that are highly vascularized. Resection surgery results in bleeding, leading to further challenges. Mixed-type UCD is rare. We report the case of a 38-year-old asymptomatic patient with mixed-type UCD; the tumor measured 7.8 cm in size and had unclear boundaries. The tumor was successfully resected by performing a cardiopulmonary bypass on the beating heart; the patient recovered uneventfully.

AuFe3@Pd/γ-Fe2O3 Nanosheets as an In Situ Regenerable and Highly Efficient Hydrogenation Catalyst.

Heterogenous Pd catalysts play a pivotal role in the chemical industry; however, it is plagued by S2- or other strong adsorbates inducing surface poisoning long term. Herein, we report the development of AuFe3@Pd/γ-Fe2O3 nanosheets (NSs) as an in situ regenerable and highly active hydrogenation catalyst. Upon poisoning, the Pd monolayer sites could be fully and oxidatively regenerated under ambient conditions, which is initiated by •OH radicals from surface defect/FeTetra vacancy-rich γ-Fe2O3 NSs via the Fenton-like pathway. Both experimental and theoretical analyses demonstrate that for the electronic and geometric effect, the 2-3 nm AuFe3 intermetallic nanocluster core promotes the adsorption of reactant onto Pd sites; in addition, it lowers Pd's affinity for •OH radicals to enhance their stability during oxidative regeneration. When packed into a quartz sand fixed-bed catalyst column, the AuFe3@Pd/γ-Fe2O3 NSs are highly active in hydrogenating the carbon-halogen bond, which comprises a crucial step for the removal of micropollutants in drinking water and recovery of resources from heavily polluted wastewater, and withstand ten rounds of regeneration. By maximizing the use of ultrathin metal oxide NSs and intermetallic nanocluster and monolayer Pd, the current study demonstrates a comprehensive strategy for developing sustainable Pd catalysts for liquid catalysis.

Promoting Effect of Nitride as Support for Pd Hydrodechlorination Catalyst.

Pd-catalyzed reductive decontamination is considerably promising in the safe handling of various pollutants, and previous studies on heterogeneous Pd catalysts have demonstrated the key role of support in determining their catalysis performance. In this work, metal nitrides were studied as supports for Pd as a hydrodechlorination (HDC) catalyst. Density functional theory study showed that a transition metal nitride (TMN) support could effectively modulate the valence-band state of Pd. The upward shift of the d-band center reduced the energy barrier for water desorption from the Pd site to accommodate H2/4-chlorophenol and increased the total energy released during HDC. The theoretical results were experimentally verified by synthesizing Pd catalysts onto different metal oxides and the corresponding nitrides. All studied TMNs, including TiN, Mo2N, and CoN, showed satisfactorily stabilized Pd and render Pd with high dispersity. In line with theoretical prediction, TiN most effectively modulated the electronic states of the Pd sites and enhanced their HDC performance, with mass activity much higher than those of counterpart catalysts on other supports. The combined theoretical and experimental results shows that TMNs, especially TiN, are new and potentially important support for the highly efficient Pd HDC catalysts.