Rubellicoccus peritrichatus gen. nov., sp. nov., isolated from crustose coralline algae in a coral aquarium.

A Gram-stain-negative, motile, aerobic, non-spore-forming coccus, designated strain CR14T, was isolated from crustose coralline algae. Cells grew at 20-30 °C (optimum, 25 °C), at pH 6-9 (optimum, pH 7.6) and with NaCl concentrations of 0.5-9 % (w/v; optimum, 2-4 %). Global alignment based on 16S rRNA gene sequences indicated strain CR14T is closest to Ruficoccus amylovorans JCM 31066T with an identity of 92 %. The average nucleotide identity and average amino acid identity values between CR14T and R. amylovorans JCM 31066T were 68.4 and 59.9 %, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CR14T forms an independent branch within the family Cerasicoccaeae, which was consistent with the phylogenomic results. The sole isoprenoid quinone was MK-7. The major fatty acids were C14 : 0, C18 : 1 ω9c, C19 : 0 cyc 9,10 DMA, C16 : 0, and C18 : 2 ω6c. The major cellular polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and two unidentified lipids. The genome DNA G+C content was 48.7 mol%. Based on morphological, physiological and chemotaxonomic characteristics, strain CR14T is suggested to represent a novel species in a new genus, for which the name Rubellicoccus peritrichatus gen. nov., sp. nov. is proposed. The type strain is CR14T (=MCCC 1K03845T=KCTC 72139T).

The tolerance of two marine diatoms to diurnal pH fluctuation under dynamic light condition and ocean acidification scenario.

Coastal waters undergo dynamic changes in seawater carbonate chemistry due to natural and anthropogenic factors. Despite this, our current understanding of how coastal phytoplankton respond to fluctuating pH is limited. In the present study, we investigated the physiological responses of two coastal diatoms Thalassiosira pseudonana and Thalassiosira weissflogii to seawater acidification and diurnally fluctuating pH under natural solar irradiance. Seawater acidification did not significantly impact the growth, maximum and effective quantum yield of PSII, and photosynthetic rates of the two species. However, it did increase the maximum relative electron transport rate of T. weissflogii by 11%. Overall, fluctuating pH had neutral or positive effects on both species. It enhanced the light-saturated photosynthetic rate of T. weissflogii by 20% compared to cells grown under seawater acidification condition. Results from the short-term pH exposure experiment revealed that the photosynthetic rates of both species remained unaffected by acute pH changes, indicating their tolerance to varying pH. Nevertheless, it is crucial to consider dynamic pH when predicting changes in primary production in coastal waters, given the interplay of various environmental drivers.

Characteristics of DOM and bacterial community in rural black and odorous water bodies under different dimensions.

Analysis of dissolved organic matter (DOM) composition and microbial characteristics is crucial for tracing the sources of rural black and odorous water bodies (BOWB). The aim of this study was to explore the DOM and microbial diversity and identify the primary environmental factors in BOWB from various pollution sources during different periods using EEMs-PARAFAC and Illumina sequencing. It was found that the physicochemical properties vary widely across different pollution types of BOWB, with higher overall content during the high-water period compared to the normal-water period. The types of dissolved organic matter in BOWB are Tyrosine proteins, Fulvic acid, Dissolved microbial metabolites, and Humic acid. During the normal-water period, DOM originates primarily from terrestrial sources in various water bodies. However, DOM affected by livestock and poultry waste and industrial effluents is influenced by both internal and external sources during periods of high water levels. In industrial waste-type BOWB, the biological sources of water are weak. Proteobacteria, Actinobacteria, Chloroflexi, Firmicutes were the dominant bacterial phyla. According to the redundancy analysis, pH (p = 0.047), Total nitrogen (TN) (p = 0.045), Organic carbon (OC) (p = 0.044), and Nickel (Ni) (p = 0.047) are the primary environmental factors influencing the composition of bacterial communities.

A genome-wide CRISPR screening uncovers that TOB1 acts as a key host factor for FMDV infection via both IFN and EGFR mediated pathways.

The interaction between foot-and-mouth disease virus (FMDV) and the host is extremely important for virus infection, but there are few researches on it, which is not conducive to vaccine development and FMD control. In this study, we designed a porcine genome-scale CRISPR/Cas9 knockout library containing 93,859 single guide RNAs targeting 16,886 protein-coding genes, 25 long ncRNAs, and 463 microRNAs. Using this library, several previously unreported genes required for FMDV infection are highly enriched post-FMDV selection in IBRS-2 cells. Follow-up studies confirmed the dependency of FMDV on these genes, and we identified a functional role for one of the FMDV-related host genes: TOB1 (Transducer of ERBB2.1). TOB1-knockout significantly inhibits FMDV infection by positively regulating the expression of RIG-I and MDA5. We further found that TOB1-knockout led to more accumulation of mRNA transcripts of transcription factor CEBPA, and thus its protein, which further enhanced transcription of RIG-I and MDA5 genes. In addition, TOB1-knockout was shown to inhibit FMDV adsorption and internalization mediated by EGFR/ERBB2 pathway. Finally, the FMDV lethal challenge on TOB1-knockout mice confirmed that the deletion of TOB1 inhibited FMDV infection in vivo. These results identify TOB1 as a key host factor involved in FMDV infection in pigs.

Research on the effectiveness and safety of bronchial thermoplasty in patients with chronic obstructive pulmonary disease.

OBJECTIVES: To investigate the clinical efficacy and safety of bronchial thermoplasty (BT) in treating patients with chronic obstructive pulmonary disease (COPD). METHODS: Clinical data of 57 COPD patients were randomized into the control (n = 29, conventional inhalation therapy) or intervention group (n = 28, conventional inhalation therapy plus BT). Primary outcomes were differences in clinical symptom changes, pulmonary function-related indicators, modified Medical Research Council (mMRC), 6-min walk test (6MWT), COPD assessment test (CAT) score and acute exacerbation incidence from baseline to an average of 3 and 12 months. Safety was assessed by adverse events. RESULTS: FEV1, FEV1(%, predicted) and FVC in both groups improved to varying degrees post-treatment compared with those pre-treatment (P < 0.05). The Intervention group showed greater improving amplitudes of FEV1 (Ftime × between groups = 21.713, P < 0.001) and FEV1(%, predicted) (Ftime × between groups = 31.216, P < 0.001) than the control group, and there was no significant difference in FVC variation trend (Ftime × between groups = 1.705, P = 0.193). mMRC, 6MWT and CAT scores of both groups post-treatment improved to varying degrees (Ps < 0.05), but the improving amplitudes of mMRC (Ftime × between groups = 3.947, P = 0.025), 6MWT (Ftime × between groups = 16.988, P < 0.001) and CAT score (Ftime × between groups = 16.741, P < 0.001) in the intervention group were greater than the control group. According to risk assessment of COPD acute exacerbation, the proportion of high-risk COPD patients with acute exacerbation in the control and intervention groups at 1 year post-treatment (100% vs 65%, 100% vs 28.6%), inpatient proportion (100% vs 62.1%; 100% vs 28.6%), COPD acute exacerbations [3.0 (2.50, 5.0) vs 1.0 (1.0, 2.50); 3.0(3.0, 4.0) vs 0 (0, 1.0)] and hospitalizations [2.0 (2.0, 3.0) vs 1.0 (0, 2.0); 2.0 (2.0, 3.0) vs 0 (0, 1.0)] were significantly lower than those pre-treatment (P < 0.05). Besides, data of the intervention group were significantly lower than the control group at each timepoint after treatment (P < 0.05). CONCLUSIONS: Combined BT therapy is superior to conventional medical treatment in improving lung function and quality of life of COPD patients, and it also significantly reduces the COPD exacerbation risk without causing serious adverse events.

Rapid weaning from mechanical ventilation and bronchial thermoplasty for near-fatal asthma: A case report.

Background: The action mechanism of bronchial thermoplasty (BT) is poorly understood. Generally, patients with severe asthma who are in desperate need of treatment have relatively low baseline values. In this paper, we describe the case of an asthmatic patient who was saved by a combination of therapy and bronchial thermoplasty. Case information: A patient with near-fatal asthma was initially treated in our hospital with conventional medication, but his condition did not improve. The patient was next subjected to invasive mechanical ventilation, which did not provide significant relief. Additionally, he was treated with BT in conjunction with mechanical ventilation, which promptly reversed his status asthmaticus and stabilized his condition. Conclusion: Patients with near-fatal asthma who do not react effectively to aggressive therapy may benefit from BT.

A high-throughput microfluidic device inspired by the Wheatstone bridge principle for characterizing the mechanical properties of single cells.

The mechanical properties of single cells have been recognized as biomarkers for identifying individual cells and diagnosing human diseases. Microfluidic devices based on the flow cytometry principle, which are not limited by the vision field of a microscope and can achieve a very high throughput, have been extensively adopted to measure the mechanical properties of single cells. However, these kinds of microfluidic devices usually required pressure-driven pumps with a very low flow rate and high precision. In this study, we developed a high-throughput microfluidic device inspired by the Wheatstone bridge principle for characterizing the mechanical properties of single cells. The microfluidic analogue of the Wheatstone bridge not only took advantage of flow cytometry, but also allowed precise control of a very low flow rate through the constricted channel with a higher input flow rate generated by a commercially available pressure-driven pump. Under different input flow rates of the pump, the apparent elastic moduli and the fluidity of osteosarcoma (U-2OS) cells and cervical carcinoma (HeLa) cells were measured by monitoring their dynamic deformations passing through the bridge-channel with different sizes of rectangular constrictions. The results showed that the input flow rate had little effect on measuring the mechanical properties of the cells, while the ratio of cell radius to effective constriction radius was different, i.e., for U-2OS cells it was 1.20 and for HeLa cells it was 1.09. Under this condition compared with predecessors, our statistic results of cell mechanical properties exhibited minimal errors. Furthermore, the cell viability after measurements was kept above 90% that demonstrated the non-destructive property of our proposed method.

Formation Optimization, Characterization and Antioxidant Activity of Auricularia auricula-judae Polysaccharide Nanoparticles Obtained via Antisolvent Precipitation

Auricularia auricula-judae polysaccharide (AAP)-based nanoparticles (NPs) prepared via an anti-solvent precipitation approach were studied. Response surface methodology (RSM) design was carried out on the basis of single factor experiments, using average size and polydispersity index (PDI) as indicators. The optimal preparation conditions were determined to include an AAP concentration of 1 mg/mL, a pH of 8, and an anti-solvent/solvent volume ratio of 6. The average particle sizes of the AAP-NPs, PDI and electrical characteristic (ζ-potential) were found to be 150.27 ± 3.21 nm, 0.135 ± 0.012 and -31.10 ± 0.52 mV, respectively. Furthermore, Fourier transform infrared spectroscopy (FTIR) was used to determine the chemical structure of the AAP-NPs. It was observed that the intensity of AAP-NPs in the wide spectral band of 3000-3750 cm-1 was significantly stronger than that of the AAP, as was the characteristic peak of carboxyl anion, and the characteristic band moved to shorter wavelengths. Subsequent thermogravimetric analysis showed that the antisolvent precipitation method improved the thermal stability of the AAP, while scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed that the morphology of AAP-NPs was uniform and well-distributed, and that their single crystal structures had remained unaffected during the process. Moreover, the DPPH and ABTS scavenging activities of AAP-NPs were increased, and the IC50 values were 0.544 ± 0.241 mg/mL and 0.755 ± 0.226 mg/mL, respectively.

Correlation of Activation Site and Number with the Clinical Response to Bronchial Thermoplasty.

Objective: To investigate the relation of activation site and number with clinical response to bronchial thermoplasty (BT) in refractory asthma patients. Methods: This work included 106 consecutive refractory asthma patients completing three BT sessions in our hospital from May 2016 to May 2019. Procedure details included recording delivery sites and those in BT. Asthma Control Questionnaire (ACQ) scores and spirometric measurements were recorded 1-day before treatment and 6 months post-treatment to explore the effects of BT activation number and site on clinical response. Results: ACQ score (3.19±1.14 vs 1.26±0.63), forced expiratory volume in 1 sec (FEV1)% predicted (55.53±21.66 vs 66.19±22.50), FEV1 (1.53±0.74 vs 1.93±0.82), and forced vital capacity (FVC) (2.49±0.86 vs 2.92±0.94) significantly increased after three BT sessions compared with pre-session. Major bronchial ablation did not significantly improve BT response in asthma patients. Multivariate logistic regression identified baseline ACQ score and baseline FEV1% predicted as independent factors affecting the clinical response to BT. Correlation and regression analysis revealed a significant linear relationship between baseline ACQ and ACQ improvement, as well as a linear relationship between the third session activation number and ACQ improvement. Based on subgroup analysis of activation number, cohort C (activations ≥ 200) had better lung function, lower non-responding rate, and better long-term effectiveness than the other two cohorts. The activation number in the third BT session showed the strongest predictive ability compared with the first two sessions. Conclusion: Main bronchial ablation did not markedly affect clinical response to BT. Baseline ACQ and baseline FEV1% predicted were independent factors affecting clinical response to BT. Increasing the activation number might promote the therapeutic efficacy of BT, and the activation number in the third BT session correlated with and predicted the BT response.

Taphonomy of microorganisms and microbial microtextures at sulfidic hydrothermal vents: A case study from the Roman Ruins black smokers, Eastern Manus Basin.

Biological activity at deep-sea hydrothermal chimneys is driven by chemotrophic microorganisms that metabolize chemicals from the venting high-temperature fluids. Understanding taphonomy and microbial microtextures in such environments is a necessity for micropaleontological and palaeoecological research. This study examines fossilized microorganisms and related microtextures in a recent black smoker from the Roman Ruins hydrothermal vent site, Eastern Manus Basin offshore of Papua New Guinea. Whereas the center of the examined sulfide chimney is dominated by high-temperature mineralogy (chalcopyrite and dendritic sphalerite), filamentous and coccoidal biomorphs occur in an outer, warm zone of mixing between hydrothermal fluids and seawater, which is indicated by their occurrence within colloform and botryoidal pyrite of barite-pyrite coprecipitates. Both morphotypes can be interpreted as thermophilic microorganisms based on their occurrence in a high-temperature habitat. Their separate (non-commensal) occurrence hints at sensitivities to microenvironmental conditions, which is expectable for strong temperature, pH, and redox gradients at the walls of deep-sea hydrothermal chimneys. Whereas both morphotypes experienced mild thermal overprint, taphonomic differences exist: (i) spaces left by cells in filamentous fossils are predominately filled by silica, whereas inter/extracellular features (crosswalls/septae and outer sheaths) are pyritized; (ii) coccoidal fossils show both silica- and pyrite-infilled interiors, and generally better preservation of cell walls. These different manifestations presumably relate to an interplay between microenvironmental and biological factors, potentially contrasting metabolisms, and differences in cell wall chemistries of distinct bacteria and/or archaea. A further hypothesis is that the coccoidal features represent biofilm-forming organisms, whose organic matter derivates contributed to the formation of intimately associated wavy and wrinkly carbonaceous laminations that are at least locally distinguishable from the texture of the surrounding pyrite. Hence, the presented data provide evidence that microtextures of microbiota from hydrothermal systems can have a similar significance for palaeobiological research as those from sedimentary environments.

Global Research Trends in Pediatric COVID-19: A Bibliometric Analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) emerged in 2019 and has since caused a global pandemic. Since its emergence, COVID-19 has hugely impacted healthcare, including pediatrics. This study aimed to explore the current status and hotspots of pediatric COVID-19 research using bibliometric analysis. METHODS: The Institute for Scientific Information Web of Science core collection database was searched for articles on pediatric COVID-19 to identify original articles that met the criteria. The retrieval period ranged from the creation of the database to September 20, 2021. A total of 3,561 original articles written in English were selected to obtain data, such as author names, titles, source publications, number of citations, author affiliations, and countries where the studies were conducted. Microsoft Excel (Microsoft, Redmond, WA) was used to create charts related to countries, authors, and institutions. VOSviewer (Center for Science and Technology Studies, Leiden, The Netherlands) was used to create visual network diagrams of keyword, author, and country co-occurrence. RESULTS: We screened 3,561 publications with a total citation frequency of 30,528. The United States had the most published articles (1188 articles) and contributed the most with author co-occurrences. The author with the most published articles was Villani from the University of Padua, Italy. He also contributed the most co-authored articles. The most productive institution was Huazhong University of Science and Technology in China. The institution with the most frequently cited published articles was Shanghai Jiao Tong University in China. The United States cooperated most with other countries. Research hotspots were divided into two clusters: social research and clinical research. Besides COVID-19 and children, the most frequent keywords were pandemic (251 times), mental health (187 times), health (172 times), impact (148 times), and multisystem inflammatory syndrome in children (MIS-C) (144 times). CONCLUSION: Pediatric COVID-19 has attracted considerable attention worldwide, leading to a considerable number of articles published over the past 2 years. The United States, China, and Italy have leading roles in pediatric COVID-19 research. The new research hotspot is gradually shifting from COVID-19 and its related clinical studies to studies of its psychological and social impacts on children.

Association of serum lipid peroxidation and glutathione peroxidase 4 levels with clinical outcomes and metabolic abnormalities among patients with gestational diabetes mellitus: a case-control study in the Chinese population.

PURPOSE: This study investigated the association of serum lipid peroxidation (LPO) and glutathione peroxidase 4 (GPx4) with gestational diabetes mellitus (GDM) and metabolic abnormalities in Chinese pregnant women. METHODS: The present case-control study was matched at a ratio of 1:1, and it recruited 132 pairs of participants at 24-28 gestational weeks. The serum LPO and GPx4 level were determined in each subject by enzyme-linked immunosorbent assay. The associations of LPO and GPx4 with metabolic parameters were analyzed. Thereafter, this study classified all subjects based on metabolic abnormality frequency (including body mass index, blood pressure, triglycerides, and fasting plasma glucose), and explored the association of the serum LPO and GPx4 levels in relation to metabolic abnormalities and clinical outcomes. Simultaneously, logistic regression analysis was used to estimate the odds radio (OR) and 95% confidence interval (CI) expressing the association between LPO/GPx4 and metabolic abnormalities. RESULTS: Women with gestational diabetes mellitus (GDM) in second trimester displayed an increased LPO concentration, whereas the GPx4 concentration was decreased compared with normal subjects (174.58 ± 22.01 ng/mL vs. 119.54 ± 8.93 ng/mL, p < 0.001 and 27.31 ± 16.88 vs. 33.84 ± 19.55 ng/mL, p < 0.001, respectively). In addition, the GPx4 concentration was negatively associated with the plasma fasting 2 h plasma glucose level (2h-PG) and percentage glycated albumin (GA%) in the second trimester. Bivariate correlation analysis revealed that in GDM patients the serum GPx4 concentration displayed a significant linear correlation with glucose metabolism indexes, including fasting plasma glucose, glycated albumin, and 2h-PG (all p < 0.05). By contrast, there was no relationship between the serum LPO concentration and glucose metabolism (p > 0.05) in GDM patients. Nevertheless, the LPO and GPx4 concentrations in the second trimester were not significantly related to the pregnancy/neonatal outcomes. Moreover, after the GDM subjects were grouped based on metabolic abnormality component, the metabolic abnormality risk was elevated with the increase in the LPO concentration (elevated diastolic blood pressure, OR = 1.04, p = 0.048; and high triglycerides, OR = 2.19, p < 0.001), together with a greater incidence of multiple metabolic abnormalities. Additionally, the serum LPO concentration increased with the increased metabolic abnormality frequency (OR = 1.93, 95% CI: 1.62-2.29, p < 0.001). CONCLUSIONS: In women with GDM, the serum GPx4 concentration was lower, which was strongly associated with second trimester glucose metabolism among the Chinese pregnant population. According to our findings, women with GDM had an increased LPO concentration, which was strongly associated with metabolic abnormalities among the pregnant women; this might be adopted as a predictor factor for metabolic abnormalities. The results of the present study suggest that a higher lipid oxidative stress and lower lipid antioxidant associated with an increased risk of GDM.

Effect of rapeseed meal degraded by enzymolysis and fermentation on the growth performance, nutrient digestibility and health status of broilers.

The purpose of this study is to investigate the nutritional changes of degraded rapeseed meal and its effects on growth performance, nutrient digestibility and health status of broilers. Raw rapeseed meal (CON), degraded by enzymolysis (protease, ERM), fermentation (Bacillus subtilis, FRM) or both (DRM) were included in diets at 25% and fed to 480 yellow-feathered broilers at 22-63 d of age. Results showed that rapeseed peptide contents (≤1 kDa) were increased (p < 0.05) from 4.13% (CON) to 35.5% (ERM), 24.1% (FRM) and 50.4% (DRM); glucosinolate and erucic acid in DRM were decreased (p < 0.05) by 71.6% and 86.2%, respectively, compared to CON. There were increases (p ≤ 0.029) in feed intake, body weight gain, feed efficiency and precaecal digestibility of dry matter, crude protein, methionine, isoleucine, leucine, lysine, cysteine, phenylalanine, tyrosine, threonine, tryptophan and valine in the three degraded diets. Also, serum immunoglobulin (Ig) A, IgG, glutathione peroxidase, superoxide dismutase and catalase were raised (p ≤ 0.034) in the degraded diets. Additionally, DRM showed more pronounced effects (p < 0.05) on variables related to growth, digestibility and health than ERM and FRM. It is concluded that rapeseed meal degraded by both enzymolysis and fermentation can increase its nutritional values and application in broilers.

Adsorption behaviors and mechanisms of antibiotic norfloxacin on degradable and nondegradable microplastics.

The misuse of both antibiotics and plastics significantly increases the environmental pollution problems associated with these contaminants. Moreover, microplastics can adsorb other pollutants in the environment. However, the mechanisms of antibiotic adsorption by degradable and nondegradable microplastics are not completely understood. In this study, we investigated the environmental behavior of norfloxacin (NOR) using polybutylene succinate (PBS), which is a degradable microplastic, and compared it with conventional microplastics, polystyrene (PS) and polyethylene (PE). The order of adsorption capacity was PS > PBS â‰« PE. The adsorption behavior fitted well with the pseudo-second-order kinetic and Langmuir isotherm models, indicating monolayer adsorption. The process is thermodynamically endothermic and non-spontaneous and is controlled by chemical and physical mechanisms, including π-π conjugation, hydrogen bonds, ion exchange, and electrostatic interactions. The adsorption capacity of microplastics was higher when the solution pH was around the pKa value of NOR than at other pH values. Ionic strength and dissolved organic matter inhibited the adsorption process. For PS and PBS, the amount of NOR adsorbed onto MPs initially decreased and then increased with the increase of coexisting heavy metal ions. Zn2+ and Pb2+ could promote the adsorption of NOR by PE. This study reveals the interaction mechanisms between microplastics and antibiotics and provides a more comprehensive theoretical basis for an ecological environmental risk assessment of different microplastics.

Design and construction strategies to improve covalent organic frameworks photocatalyst's performance for degradation of organic pollutants.

Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers. In recent years, COFs have received extensive attention in the field of photocatalytic degradation due to their large specific surface area, good thermal and solvent stability, and diverse structures. This review studies the progress of COF in the field of photocatalytic degradation, and summarizes the strategies to improve the photocatalytic activity of covalent organic frameworks, including the designs of ligands and structures. In particular, the design and construction of the COF composites (COF/MOF, COF/g-C3N4, COF/metal semiconductor) are discussed. The photocatalytic mechanism is described in detail, and the prospect of COFs in photocatalytic degradation is prospected.

A microfluidic system for precisely reproducing physiological blood pressure and wall shear stress to endothelial cells.

To reproduce hemodynamic stress microenvironments of endothelial cells in vitro is of vital significance, by which one could exploit the quantitative impact of hemodynamic stresses on endothelial function and seek innovative approaches to prevent circulatory system diseases. Although microfluidic technology has been regarded as an effective method to create physiological microenvironments, a microfluidic system to precisely reproduce physiological arterial hemodynamic stress microenvironments has not been reported yet. In this paper, a novel microfluidic chip consisting of a cell culture chamber with on-chip afterload components designed by the principle of input impedance to mimic the global hemodynamic behaviors is proposed. An external feedback control system is developed to accurately generate the input pressure waveform. A lumped parameter hemodynamic model (LPHM) is built to represent the input impedance to mimic the on-chip global hemodynamic behaviors. Sensitivity analysis of the model parameters is also elaborated. The performance of reproducing physiological blood pressure and wall shear stress is validated by both numerical characterization and flow experiment. Investigation of intracellular calcium ion dynamics in human umbilical vein endothelial cells is finally conducted to demonstrate the biological applicability of the proposed microfluidic system.

Oxygen Vacancies and Lewis Acid Sites Synergistically Promoted Catalytic Methane Combustion over Perovskite Oxides.

An in-depth understanding of the surface properties-activity relationship could provide a fundamental guidance for the design of highly efficient perovskite-based catalysts for the control of anthropogenic methane emission. Herein, both oxygen vacancies and Con+ Lewis acid sites were purposely introduced on ordered macroporous La0.8Sr0.2CoO3 monolithic catalysts by one-step reduction and selective etching in oxalic acid, and their synergistic effect on methane combustion was investigated. Combined with experimental and theoretical investigations, we revealed that the positively charged Con+ Lewis acid sites and single-electron-trapped oxygen vacancies (Vo·) formed an active pair, which enabled an effective localized electron cloud shift from Vo· to Con+. The characteristic electronic effect modulates surface electronic properties and coordination structures, thus resulting in superior oxygen activation capacity, lattice oxygen mobility, and reducibility, as well as favorable CH4 interaction and oxidation. Our work not only gives insights into surface properties-activity relationships on perovskite for hydrocarbon combustion but also sheds substantial light on future environmental catalyst design and modulation for hydrocarbon pollutants elimination.

Interfacial sp C-O-Mo Hybridization Originated High-Current Density Hydrogen Evolution.

High-current density (≥1 A cm-2) is a critical factor for large-scale industrial application of water-splitting electrocatalysts, especially seawater-splitting. However, it still remains a great challenge to reach high-current density due to the lack of active and stable intrinsic catalytic active sites in catalysts. Herein, we report an original three-dimensional self-supporting graphdiyne/molybdenum oxide (GDY/MoO3) material for efficient hydrogen evolution reaction via a rational design of "sp C-O-Mo hybridization" on the interface. The "sp C-O-Mo hybridization" creates new intrinsic catalytic active sites (nonoxygen vacancy sites) and increases the amount of active sites (eight times higher than pure MoO3). The "sp C-O-Mo hybridization" facilitates charge transfer and boosts the dissociation process of H2O molecules, leading to outstanding HER activity with high-current density (>1.2 A cm-2) in alkaline electrolyte and a decent activity and stability in natural seawater. Our results show that high-current density electrocatalysts can be achieved by interfacial chemical bond engineering, three-dimensional structure design, and hydrophilicity optimization.

A comparison study of sodium ion- and potassium ion-modified graphitic carbon nitride for photocatalytic hydrogen evolution.

It is well known that modifying graphitic carbon nitride (GCN) is an imperative strategy to improve its photocatalytic activity. In this study, Na-doped and K-doped graphitic carbon nitride (GCN-Na and GCN-K) were prepared via the simple thermal polymerization of a mixture of melamine and NaCl or KCl, respectively. The structure characterization showed that both Na+ and K+ intercalation could reduce the interlayer distance of GCN and introduce cyano defects in GCN, while K+ apparently had a stronger influence on the structure variation of GCN. The chemical composition data showed that both Na+ and K+ could easily interact with GCN, while K-doping caused a greater change in the C/N ratio than Na-doping. Moreover, compared to GCN-Na-5 (5 represents weight ratio of alkali halide to melamine), the conduction and valence bands of GCN-K-5 both shifted upward based on the electronic and optical measurements. Consequently, GCN-K-5 yielded an H2 evolution rate around 4 times higher than that of GCN-Na-5 under visible light irradiation (>420 nm). The cation size effect on GCN was proposed to be mainly responsible for the variation in the structure, optical and electronic properties of ion-doped GCNs, and hence the enhanced photocatalytic H2 evolution. The current work can provide new insight into optimizing photocatalysts for enhanced photocatalytic performances.

Investigation of the Internal Structure of a Modern Seafloor Hydrothermal Chimney With a Combination of EBSD, EPMA, and XRD.

Samples from the sphalerite-dominated zone of a seafloor massive sulfide chimney, the Satanic Mills Chimney of the PACMANUS hydrothermal field, have been investigated to determine the internal macrostructure and microstructure of this zone, the phases present, and the distribution of metals. A combination of electron probe microanalysis, electron backscattered diffraction, and x-ray diffraction has been used. At the macroscale, this zone of the chimney wall is heavily porous and is comprised primarily of sphalerite, enclosing minor chalcopyrite, pyrite, and wurtzite. A Pb­As sulfosalt layer of possible microbial origins is present at the outer edge of the sphalerite matrix, next to a pore. The sphalerite has grown in globules on the order of 300 µm in diameter. At the microscale, the sphalerite features a colloform texture and a duplex-type grain structure consisting of either fine-grain regions in the center surrounded by coarse-grained regions or radiating coarse grains only. Pb- and As-rich bands have been detected in the colloform sphalerite, and growth twins have been observed in both the sphalerite and chalcopyrite crystals. A qualitative description of the growth of a typical globule is given, including nucleation, crystal growth, and solute redistribution.