High yield electrosynthesis of oxygenates from CO using a relay Cu-Ag co-catalyst system.

As a sustainable alternative to fossil fuel-based manufacture of bulk oxygenates, electrochemical synthesis using CO and H2O as raw materials at ambient conditions offers immense appeal. However, the upscaling of the electrosynthesis of oxygenates encounters kinetic bottlenecks arising from the competing hydrogen evolution reaction with the selective production of ethylene. Herein, a catalytic relay system that can perform in tandem CO capture, activation, intermediate transfer and enrichment on a Cu-Ag composite catalyst is used for attaining high yield CO-to-oxygenates electrosynthesis at high current densities. The composite catalyst Cu/30Ag (molar ratio of Cu to Ag is 7:3) enables high efficiency CO-to-oxygenates conversion, attaining a maximum partial current density for oxygenates of 800 mA cm-2 at an applied current density of 1200 mA cm-2, and with 67 % selectivity. The ability to finely control the production of ethylene and oxygenates highlights the principle of efficient catalyst design based on the relay mechanism.

Synergistic Effect of Ni/Ni(OH)2 Core-Shell Catalyst Boosts Tandem Nitrate Reduction for Ampere-Level Ammonia Production.

Electrocatalytic reduction of nitrate to ammonia provides a green alternate to the Haber-Bosch method, yet it suffers from sluggish kinetics and a low yield rate. The nitrate reduction follows a tandem reaction of nitrate reduction to nitrite and subsequent nitrite hydrogenation to generate ammonia, and the ammonia Faraday efficiency (FE) is limited by the competitive hydrogen evolution reaction. Herein, we design a heterostructure catalyst to remedy the above issues, which consists of Ni nanosphere core and Ni(OH)2 nanosheet shell (Ni/Ni(OH)2). In-situ Raman spectroscopy reveals Ni and Ni(OH)2 are interconvertible according to the applied potential, facilitating the cascade nitrate reduction synergistically. Consequently, it attains superior electrocatalytic nitrate reduction performance with an ammonia FE of 98.50% and a current density of 0.934 A cm-2 at -0.476 V versus reversible hydrogen electrode, and exhibits an average ammonia yield rate of 84.74 mg h-1 cm-2 during the 102-hour stability test, which is highly superior to the reported catalysts tested under similar conditions. Density functional theory calculations corroborate the synergistic effect of Ni and Ni(OH)2 in the tandem reaction of nitrate reduction. Moreover, the Ni/Ni(OH)2 catalyst also possesses good capability for methanol oxidation and thus is used to establish a system coupling with nitrate reduction.

Direct Electroreduction of Carbonate to Formate.

A cause of losses in energy and carbon conversion efficiencies during the electrochemical CO2 reduction reaction (eCO2RR) can be attributed to the formation of carbonates (CO32-), which is generally considered to be an electrochemically inert species. Herein, using in situ Raman spectroscopy, liquid chromatography, 1H nuclear magnetic resonance spectroscopy, 13C and deuterium isotope labeling, and density functional theory simulations, we show that carbonate intermediates are adsorbed on a copper electrode during eCO2RR in KHCO3 electrolyte from 0.2 to -1.0 VRHE. These intermediates can be reduced to formate at -0.4 VRHE and more negative potentials. This finding is supported by our observation of formate from the reduction of Cu2(CO3)(OH)2. Pulse electrolysis on a copper electrode immersed in a N2-purged K2CO3 electrolyte was also performed. We found that the carbonate anions therein could be first adsorbed at -0.05 VRHE and then directly reduced to formate at -0.5 VRHE (overpotential of 0.28 V) with a Faradaic efficiency of 0.61%. The nature of the active sites generating the adsorbed carbonate species and the mechanism for the pulse-enabled reduction of carbonate to formate were elucidated. Our findings reveal how carbonates are directly reduced to a high-value product such as formate and open a potential pathway to mitigate carbonate formation during eCO2RR.

[LPS-induced endothelial cytoskeleton remodeling in human lung vessels and related miRNAs-profiling].

Objective To investigate the effects of lipopolysaccharide (LPS) on human pulmonary vascular endothelial cells (HPVECs) cytoskeleton and perform biological analysis of the microRNA (miRNA) spectrum. Methods The morphology of HPVECs was observed by microscope, the cytoskeleton by FITC-phalloidin staining, and the expression of VE-cadherin was detected by immunofluorescence cytochemical staining; the tube formation assay was conducted to examine the angiogenesis, along with cell migration test to detect the migration, and JC-1 mitochondrial membrane potential to detect the apoptosis. Illumina small-RNA sequencing was used to identify differentially expressed miRNAs in NC and LPS group. The target genes of differentially expressed miRNAs were predicted by miRanda and TargetScan, and the functional and pathway enrichment analysis was performed on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Further biological analysis of related miRNAs was carried out. Results After the LPS got induced, the cells became round and the integrity of cytoskeleton was destroyed. The decreased expression of VE-cadherin was also observed, along with the decreased ability of angiogenesis and migration, and increased apoptosis. Sequencing results showed a total of 229 differential miRNAs, of which 84 miRNA were up-regulated and 145 miRNA were down-regulated. The target gene prediction and functional enrichment analysis of these differential miRNA showed that they were mainly concentrated in pathways related to cell connection and cytoskeleton regulation, cell adhesion process and inflammation. Conclusion In vitro model of lung injury, multiple miRNAs are involved in the process of HPVECs cytoskeleton remodeling, the reduction of barrier function, angiogenesis, migration and apoptosis.

Pt single atoms meet metal-organic frameworks to enhance electrocatalytic hydrogen evolution activity.

The electrochemical hydrogen evolution reaction (HER) effectively produces clean, renewable, and sustainable hydrogen; however, the development of efficient electrocatalysts is required to reduce the high energy barrier of the HER. Herein, we report two excellent single-atom (SA)/metal-organic framework (MOF) composite electrocatalysts (PtSA-MIL100(Fe) and PtSA-MIL101(Cr)) for HER. The obtained PtSA-MIL100(Fe) and PtSA-MIL101(Cr) electrocatalysts exhibit overpotentials of 60 and 61 mV at 10 mA cm-2, respectively, which are close to that of commercial Pt/C (38 mV); they exhibit overpotentials of 310 and 288 mV at 200 mA cm-2, respectively, which are comparable to that of commercial Pt/C (270 mV). Theoretical simulations reveal that Pt SAs modulate the electronic structures of the MOFs, leading to the optimization of the binding strength for H* and significant enhancement of the HER activity. This study describes a novel strategy for preparing desirable HER electrocatalysts based on the synergy between SAs and MIL-series MOFs. Using MIL-series MOFs to support SAs could be valuable for future catalyst design.

First Report of Lasiodiplodia theobromae Causing Brown Leaf Spot on Bruguiera gymnorrhiza in China.

Bruguiera gymnorrhiza (Linn.) Sav. is a dominant tree species of mangrove forests in tropical coastal areas of China. This species is commonly used for the greening of tidal flats and seawalls in tropical and subtropical regions (Allen, & Duke 2000). A survey that was conducted from August to September 2020, in the mangrove national nature reserve at Zhanjiang, Guangdong Province, South China. Brown leaf spot symptoms were observed on Bruguiera gymnorrhiza and disease incidence was over 10% (200 investigated trees). Symptomatic small spots initially appeared at the middle or edges of leaves, enlarged irregularly, and developed into brown necrotic spots with dying curly edges. The color of the lesion's center changed to dark brown or gray. To identify the causative agent, twenty diseased leaves were sampled for pathogen isolation. Affected foliar tissues cut into 5 × 5 mm pieces, disinfected in 75% ethanol for 2 mins, rinsed in sterile distilled water, and then air dried under a sterilized filter paper. Leaf pieces were plated onto potato dextrose agar (PDA) in Petri dishes and then incubated at 28°C in darkness for 3-5 days. Hyphal tips of fungal colonies growing from the tissue pieces were subcultured onto fresh PDA to obtain pure single hyphae cultures. The fungal colonies were initially composed of white aerial mycelia, but turned gray after 7 days. Immature conidia were hyaline, subovoid, and aseptate while mature conidia becoming dark brown, one-septate with longitudinal stripes, the length/width ratio is 19.98 to 29.50 µm (average 24.37 µm; n = 50) × 11.99 to 14.45 µm (average 13.09 µm; n = 50). On the basis of morphological features all isolates were identified as Lasiodiplodia theobromae (Pat.) Griffon & Maubl (Alves et al. 2008). For DNA-based identification, the internal transcribed spacer (ITS) region gene and fragment of elongation factor 1-alpha (EF1-α) gene of the three isolates were amplified and sequenced following the methods described in a previous study (White et al. 1990, Carbone & Kohn 1999). The obtained sequences of ITS and EF1-α were deposited in GenBank with accession numbers OK644200 and OL345571. The BLAST results showed at least 99.60% similarity with the sequences of Lasiodiplodia theobromae (ITS, MT644474.1 [99.79%]; EF1-a, MK961975.1 [99.60%]). To fulfill Koch's postulates, PDA plugs with actively growing mycelium of the isolates were inoculated on the leaves of Bruguiera gymnorrhiza plants that were wounded by using a sterilized needle or scalpel. Inoculated leaves were covered with sterilized wet cotton, and the plants were kept at 28°C and 80% relative humidity. The inoculated plants showed leaf spot symptoms that were similar to those previously observed in the field after 1-2 days, whereas control leaves remained healthy. Lasiodiplodia theobromae was consistently isolated from inoculated leaves again. Lasiodiplodia theobromae (Botryosphaeriaceae) is a plurivorous pathogen in a wide variety of hosts, mostly prevalent in tropical and subtropical climate regions. It has been previously reported to cause brown leaf spot on Broussonetia papyrifera (Luo et al. 2020), foliar diseases on Camellia oleifera (Zhu et al. 2014) and Kadsura longipedunculata (Fan et al. 2020). To our knowledge, this is the first report of Lasiodiplodia theobromae causing brown leaf spot on Bruguiera gymnorrhiza plants in China and worldwide. Our findings will help to make management strategies for control of this disease on Bruguiera gymnorrhiza.

Medium/High-Entropy Amalgamated Core/Shell Nanoplate Achieves Efficient Formic Acid Catalysis for Direct Formic Acid Fuel Cell.

High-entropy alloys (HEAs) have been attracting extensive research interests in designing advanced nanomaterials, while their precise control is still in the infancy stage. Herein, we have reported a well-defined PtBiPbNiCo hexagonal nanoplates (HEA HPs) as high-performance electrocatalysts. Structure analysis decodes that the HEA HP is constructed with PtBiPb medium-entropy core and PtBiNiCo high-entropy shell. Significantly, the HEA HPs can reach the specific and mass activities of 27.2 mA cm-2 and 7.1 A mgPt -1 for formic acid oxidation reaction (FAOR), being the record catalyst ever achieved in Pt-based catalysts, and can realize the membrane electrode assembly (MEA) power density (321.2 mW cm-2 ) in fuel cell. Further experimental and theoretical analyses collectively evidence that the hexagonal intermetallic core/atomic layer shell structure and multi-element synergy greatly promote the direct dehydrogenation pathway of formic acid molecule and suppress the formation of CO*.

Molecular Diversity and Evolutionary Relatedness of Paulownia Witches'-Broom Phytoplasma in Different Geographical Distributions in China.

To reveal the distribution and transmission pathway of Paulownia witches'-broom (PaWB) disease, which is caused by phytoplasmas related to genetic variation, and the adaptability to the hosts and environments of the pathogenic population in different geographical regions in China, in this study, we used ten housekeeping gene fragments, including rp, fusA, secY, tuf, secA, dnaK, rpoB, pyrG, gyrB, and ipt, for multilocus sequence typing (MLST). A total of 142 PaWB phytoplasma strains were collected from 18 provinces or municipalities. The results showed that the genetic diversity was comparatively higher among the PaWB phytoplasma strains, and substantially different from that of the other 16SrI subgroup strains. The number of gene variation sites for different housekeeping genes in the PaWB phytoplasma strains ranged from 1 to 14 SNPs. Among them, rpoB (1.47%) and dnaK (1.12%) had higher genetic variation, and rp (0.20%) had the least genetic variation. The tuf and rpoB genes showed the fixation of positively selected beneficial mutations in the PaWB phytoplasma populations, and all housekeeping genes except tuf followed the neutral evolutionary model. We found an absence of recombination among PaWB phytoplasma sequence types (STs) for each housekeeping gene except dnaK, and no evidence for such recombination events for concatenated sequences of PaWB phytoplasma strains. The 22 sequence types were identified among the concatenated sequences of seven housekeeping genes (rp, fusA, secY, secA, tuf, dnaK, and rpoB) from 105 representative strains. We analyzed all 22 STs by goeBURST algorithm, forming two clonal complexes (CCs) and three singletons. Among them, ST1, as the primary founder of CC1, had the widest geographical distribution, accounting for 72.38% of all strains, with a high frequency of shared sequence type. The results of phylogenetic analysis of the concatenated sequences further revealed that the 105 strains were clustered into two representative lineages of PaWB phytoplasma, with obvious geographical differentiation. The ST1 strains of highly homogeneous lineage-1 were a widespread and predominant population in diseased areas. Lineage-2 contained strains from Jiangxi, Fujian, and Shaanxi provinces, highlighting the close genetic relatedness of the strains in these regions, which was also consistent with the results of most single-gene phylogenetic analysis of each gene. We also found that the variability in the northwest China population was higher than in other geographical populations; the range of genetic differentiation between the south of the Yangtze River population and the Huang-huai-hai Plain (or southwest China) population was relatively large. The achieved diversity and evolution data, as well as the MLST technique, are helpful for epidemiological studies and guiding PaWB disease control decisions.

Combined transcriptome and metabolome analysis of Nerium indicum L. elaborates the key pathways that are activated in response to witches' broom disease.

BACKGROUND: Nerium indicum Mill. is an ornamental plant that is found in parks, riversides, lakesides, and scenic areas in China and other parts of the world. Our recent survey indicated the prevalence of witches' broom disease (WBD) in Guangdong, China. To find out the possible defense strategies against WBD, we performed a MiSeq based ITS sequencing to identify the possible casual organism, then did a de novo transcriptome sequencing and metabolome profiling in the phloem and stem tip of N. indicum plants suffering from WBD compared to healthy ones. RESULTS: The survey showed that Wengyuen county and Zengcheng district had the highest disease incidence rates. The most prevalent microbial species in the diseased tissues was Cophinforma mamane. The transcriptome sequencing resulted in the identification of 191,224 unigenes of which 142,396 could be annotated. There were 19,031 and 13,284 differentially expressed genes (DEGs) between diseased phloem (NOWP) and healthy phloem (NOHP), and diseased stem (NOWS) and healthy stem (NOHS), respectively. The DEGs were enriched in MAPK-signaling (plant), plant-pathogen interaction, plant-hormone signal transduction, phenylpropanoid and flavonoid biosynthesis, linoleic acid and α-linoleic acid metabolism pathways. Particularly, we found that N. indicum plants activated the phytohormone signaling, MAPK-signaling cascade, defense related proteins, and the biosynthesis of phenylpropanoids and flavonoids as defense responses to the pathogenic infection. The metabolome profiling identified 586 metabolites of which 386 and 324 metabolites were differentially accumulated in NOHP vs NOWP and NOHS and NOWS, respectively. The differential accumulation of metabolites related to phytohormone signaling, linoleic acid metabolism, phenylpropanoid and flavonoid biosynthesis, nicotinate and nicotinamide metabolism, and citrate cycle was observed, indicating the role of these pathways in defense responses against the pathogenic infection. CONCLUSION: Our results showed that Guangdong province has a high incidence of WBD in most of the surveyed areas. C. mamane is suspected to be the causing pathogen of WBD in N. indicum. N. indicum initiated the MAPK-signaling cascade and phytohormone signaling, leading to the activation of pathogen-associated molecular patterns and hypersensitive response. Furthermore, N. indicum accumulated high concentrations of phenolic acids, coumarins and lignans, and flavonoids under WBD. These results provide scientific tools for the formulation of control strategies of WBD in N. indicum.

Modifiable risk factors associated with cardiovascular disease and mortality in China: a PURE substudy.

AIMS: To examine the incidence of cardiovascular disease (CVD) and mortality in China and in key subpopulations, and to estimate the population-level risks attributable to 12 common modifiable risk factors for each outcome. METHODS AND RESULTS: In this prospective cohort of 47 262 middle-aged participants from 115 urban and rural communities in 12 provinces of China, it was examined how CVD incidence and mortality rates varied by sex, by urban-rural area, and by region. In participants without prior CVD, population-attributable fractions (PAFs) for CVD and for death related to 12 common modifiable risk factors were assessed: four metabolic risk factors (hypertension, diabetes, abdominal obesity, and lipids), four behavioural risk factors (tobacco, alcohol, diet quality, and physical activity), education, depression, grip strength, and household air pollution. The mean age of the cohort was 51.1 years. 58.2% were female, 49.2% were from urban areas, and 59.6% were from the eastern region of China. The median follow-up duration was 11.9 years. The CVD was the leading cause of death in China (36%). The rates of CVD and death were 8.35 and 5.33 per 1000 person-years, respectively, with higher rates in men compared with women and in rural compared with urban areas. Death rates were higher in the central and western regions of China compared with the eastern region. The modifiable risk factors studied collectively contributed to 59% of the PAF for CVD and 56% of the PAF for death in China. Metabolic risk factors accounted for the largest proportion of CVD (PAF of 41.7%), and hypertension was the most important risk factor (25.0%), followed by low education (10.2%), high non-high-density lipoprotein cholesterol (7.8%), and abdominal obesity (6.9%). The largest risk factors for death were hypertension (10.8%), low education (10.5%), poor diet (8.3%), tobacco use (7.5%), and household air pollution (6.1%). CONCLUSION: Both CVD and mortality are higher in men compared with women, and in rural compared with urban areas. Large reductions in CVD could potentially be achieved by controlling metabolic risk factors and improving education. Lowering mortality rates will require strategies addressing a broader range of risk factors.

Interface Engineering of Co/CoMoN/NF Heterostructures for High-Performance Electrochemical Overall Water Splitting.

The development of low-cost and high-efficiency catalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolyte is still challenging. Herein, interfacial Co/CoMoN heterostructures supported on Ni foam (Co/CoMoN/NF) are constructed by thermal ammonolysis of CoMoOx . In 1.0 m KOH solution, Co/CoMoN/NF heterostructures exhibit excellent HER activity with an overpotential of 173 mV at 100 mA cm-2  and a Tafel slope of 68.9 mV dec-1 . Density functional theory calculations indicate that the low valence state Co site acts as efficient water-dissociation promoter, while CoMoN substrate has favorable hydrogen adsorption energy, leading to an enhanced HER activity. The Co/CoMoN/NF heterostructures also achieve high OER activity with an overpotential of 303 mV at 100 mA cm-2  and a Tafel slope of 56 mV dec-1 . Using Co/CoMoN/NF heterostructures as the cathode and anode, the alkaline electrolyzer requires a low voltage of 1.56 V to reach the current density of 100 mA cm-2  along with superior long-term durability. This study provides a new design strategy toward low-cost and excellent catalysts for water splitting.

Defect-Assisted Anchoring of Pt Single Atoms on MoS2 Nanosheets Produces High-Performance Catalyst for Industrial Hydrogen Evolution Reaction.

Pt-based catalysts are currently the most efficient electrocatalysts for the hydrogen evolution reaction (HER), but the scarcity and high cost of Pt limit industrial applications. Downsizing Pt nanoparticles (NPs) to single atoms (SAs) can expose more active sites and increase atomic utilization, thus decreasing the cost. Here, a solar-irradiation strategy is used to prepare hybrid SA-Pt/MoS2 nanosheets (NSs) that demonstrate excellent HER activity (the overpotential at a current density of 10 mA cm-2 (η10 ) of 44 mV, and Tafel slope of 34.83 mV dec-1 in acidic media; η10 of 123 mV, and Tafel slope of 76.71 mV dec-1 in alkaline media). Defects and deformations introduced by thermal pretreatment of the hydrothermal MoS2 NSs promote anchoring and stability of Pt SAs. The fabrication of Pt SAs and NPs is easily controlled using different Pt-precursor concentrations. Moreover, SA-Pt/MoS2 produced under natural sunlight exhibits high HER performance (η10 of 55 mV, and Tafel slope of 43.54 mV dec-1 ), which indicates its viability for mass production. Theoretical simulations show that Pt improves the absorption of H atoms and the charge-transfer kinetics of MoS2 , which significantly enhance HER activity. A simple, inexpensive strategy for preparing SA-Pt/MoS2 hybrid catalysts for industrial HER is provided.

Efficient Electrocatalytic Nitrogen Reduction to Ammonia on Ultrafine Sn Nanoparticles.

Electrocatalytic nitrogen reduction reaction (NRR) at ambient conditions is a promising route for ammonia (NH3) synthesis but still suffers from low activity and selectivity. Here, ultrafine Sn nanoparticles (NPs) grown on carbon blacks (SnSC/C) have been synthesized through a wet-chemical method using sodium citrate dehydrate as a stabilizing agent. Benefiting from the small sizes of Sn NPs, the SnSC/C catalyst exhibits excellent electrocatalytic performance for NRR with a high Faradaic efficiency of 22.76% and an NH3 yield rate of 17.28 µg h-1 mg-1 in the 0.1 M Na2SO4 electrolyte, outperforming many reported electrocatalysts for NRR under similar conditions. Density functional theory calculation results reveal that the potential-determining step on Sn NPs is the generation of NHNH* through simultaneous hydrogenation of N2* by a H* and a H+/e- pair via Langmuir-Hinshelwood plus Eley-Rideal mechanisms.

Tuning the electronic structure of NiCoVOx nanosheets through S doping for enhanced oxygen evolution.

It is of great importance to develop efficient and low-cost oxygen evolution reaction (OER) electrocatalysts for electrochemical water splitting. Herein, S doped NiCoVOx nanosheets grown on Ni-Foam (S-NiCoVOx/NF) with a modified electronic structure have been prepared through a facile one-step hydrothermal method. The as-prepared S4.06-NiCoVOx/NF exhibits outstanding OER activity with low overpotentials of 248 mV and 289 mV to deliver current densities of 10 mA cm-2 and 100 mA cm-2, respectively, and a small Tafel slope of 46.2 mV dec-1 in 1.0 M KOH electrolyte. These values are much lower than those obtained for most of the recently reported non-noble metal-based electrocatalysts under similar experimental conditions. This study provides a simple approach to rational design of efficient and cost-effective OER electrocatalysts for practical application of electrochemical water splitting.

Association of heart rate with cardiovascular events and mortality in hypertensive and normotensive population: a nationwide prospective cohort study.

BACKGROUND: Cardiovascular disease is the leading cause of death worldwide. We assessed the association of baseline heart rate with cardiovascular events and mortality in hypertensive and normotensive populations using a prospective urban and rural epidemiology cohort study in China. METHODS: A total of 29,554 individuals were involved in our analysis, distributed equally between groups of normotensive and hypertensive. The primary outcomes were myocardial infarction, stroke, major cardiovascular diseases, and cardiovascular mortality. Cox frailty models were utilized to estimate hazard ratios for cardiovascular outcomes, and restricted cubic splines were used to explore the shape of the association between baseline heart rate and cardiovascular mortality. RESULTS: During a total observational time of 230,813 person-years, 402 myocardial infarction events, 1,096 stroke events, 1,540 major cardiovascular events, and 356 cardiovascular deaths were documented. In adjusted analyses, normotensive subjects with baseline heart rate >82.5 beats per minute had a 3.30-fold greater risk of cardiovascular death and an increased 72% risk of myocardial infarction, compared with individuals whose baseline heart rate was 65.5-71 beats per minute. A similar trend was observed for cardiovascular mortality in the hypertensive population, but the association was attenuated. Multivariable-adjusted restricted cubic splines showed linear associations between baseline heart rate and cardiovascular mortality in two groups of people (all P<0.05 for linearity). CONCLUSIONS: Elevated baseline heart rate is associated with an increased risk of cardiovascular mortality and myocardial infarction in the normotensive population. The association is attenuated for cardiovascular death in hypertensive patients.

Transcriptome and metabolome profiling in naturally infested Casuarina equisetifolia clones by Ralstonia solanacearum.

Casuarina equisetifolia is an important pioneer tree and suffers from bacterial wilt caused by Ralstonia solanacearum. We collected resistant (R) and susceptible (S) C. equisetifolia clones naturally infected by R. solanacearum and compared their transcriptome and metabolome with a clone (CK) from a non-infested forest, in order to study their response and resistance to bacterial wilt. We identified 18 flavonoids differentially accumulated among the three clonal groups as potential selection biomarkers against R. solanacearum. Flavonoid synthesis-related genes were up-regulated in the resistant clones, probably enhancing accumulation of flavonoids and boosting resistance against bacterial wilt. The down-regulation of auxin/indoleacetic acid-related genes and up-regulation of brassinosteroid, salicylic acid and jasmonic acid-related differentially expressed genes in the R vs CK and R vs S clonal groups may have triggered defense signals and increased expression of defense-related genes against R. solanacearum. Overall, this study provides an important insight into pathogen-response and resistance to bacterial wilt in C. equisetifolia.

Electroreduction of nitrogen to ammonia on nanoporous gold.

The electrochemical reduction of nitrogen (N2) to ammonia (NH3) has attracted attention as an emerging alternative to the traditional Haber-Bosch process to synthesize NH3. Unfortunately, electrocatalytic N2 reduction processes are still very inefficient. Here we report three-dimensional nanoporous gold (NPG) as an efficient and stable electrocatalyst for the N2 reduction reaction at room temperature and atmospheric pressure. NPG can deliver a high NH3 yield rate of 45.7 µg h-1 mg-1cat. and a high faradaic efficiency of 3.41% at an ultralow potential of -0.10 V versus the reversible hydrogen electrode, in 0.1 M HCl solution. These values are much higher than those obtained for most of the reported electrocatalysts under similar experimental conditions. Structural characterization and density functional theory calculations reveal that the excellent electrocatalytic activity of NPG mainly results from the high density of geometrically required surface steps and kinks.

The Roles of H19 in Regulating Inflammation and Aging.

Accumulating evidence suggests that long non-coding RNA H19 correlates with several aging processes. However, the role of H19 in aging remains unclear. Many studies have elucidated a close connection between H19 and inflammatory genes. Chronic systemic inflammation is an established factor associated with various diseases during aging. Thus, H19 might participate in the development of age-related diseases by interplay with inflammation and therefore provide a protective function against age-related diseases. We investigated the inflammatory gene network of H19 to understand its regulatory mechanisms. H19 usually controls gene expression by acting as a microRNA sponge, or through mir-675, or by leading various protein complexes to genes at the chromosome level. The regulatory gene network has been intensively studied, whereas the biogenesis of H19 remains largely unknown. This literature review found that the epithelial-mesenchymal transition (EMT) and an imprinting gene network (IGN) might link H19 with inflammation. Evidence indicates that EMT and IGN are also tightly controlled by environmental stress. We propose that H19 is a stress-induced long non-coding RNA. Because environmental stress is a recognized age-related factor, inflammation and H19 might serve as a therapeutic axis to fight against age-related diseases.

Enhanced Electrocatalytic Hydrogen Evolution Activity in Single-Atom Pt-Decorated VS2 Nanosheets.

Enhancing catalytic activity by decorating noble metals in catalysts provides an opportunity for promoting the electrocatalytic hydrogen evolution reaction (HER) application. However, there are few systematic studies on regulating the structures of noble metals in catalytic materials and investigating their influence on HER. Herein, Pt catalysts with different structures including single atoms (SAs), clusters, and nanoparticles well-controllably anchored on VS2 nanosheets through a cost-effective optothermal method are reported, and their HER performance is studied. The most efficient Pt-decorated VS2 catalyst (with both Pt SAs and clusters) delivers an overpotential of 77 mV at 10 mA cm-2, close to that of Pt/C (48 mV). However, the optimal mass activity of Pt (normalizing to Pt content) is obtained from only SA Pt-decorated VS2 (i.e., 22.88 A mgPt-1 at 200 mV) and is 12 times greater than that of the Pt/C (1.87 A mgPt-1), attributed to the greatly enhanced Pt utilization. Additionally, the theoretical simulations reveal that Pt SA decoration makes the adsorption free energy of H* closer to the thermoneutral value and improves the charge-transfer kinetics, significantly enhancing HER activity. This work offers a pathway to prepare the desired catalyst based on synergy of Pt structures and VS2 and reveals the intrinsic mechanism for enhancing catalytic activity, which is important for HER applications.

Nrf2/Keap1/ARE Signaling Mediated an Antioxidative Protection of Human Placental Mesenchymal Stem Cells of Fetal Origin in Alveolar Epithelial Cells.

The oxidative stresses are a major insult in pulmonary injury such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), two clinical manifestations of acute respiratory failure with substantially high morbidity and mortality. Mesenchymal stem cells (MSCs) hold a promise in treatments of many human diseases, mainly owing to their capacities of immunoregulation and antioxidative activity. The strong immunoregulatory role of human placental MSCs of fetal origin (hfPMSCs) has been previously demonstrated; their antioxidant activity, however, has yet been interrogated. In this report, we examined the antioxidative activity of hfPMSCs by accessing the ability to scavenge oxidants and radicals and to protect alveolar epithelial cells from antioxidative injury using both a cell coculture model and a conditioned culture medium (CM) of hfPMSCs. Results showed a comparable antioxidative capacity of the CM with 100 µM of vitamin C (VC) in terms of the total antioxidant capacity (T-AOC), scavenging abilities of free radicals DPPH, hydroxyl radical (·OH), and superoxide anion radical (O2 -), as well as activities of antioxidant enzymes of SOD and GSH-PX. Importantly, both of the CM alone and cocultures of hfPMSCs displayed a protection of A549 alveolar epithelial cells from oxidative injury of 600 µM hydrogen peroxide (H2O2) exposure, as determined in monolayer and transwell coculture models, respectively. Mechanistically, hfPMSCs and their CM could significantly reduce the apoptotic cell fraction of alveolar epithelial A549 cells exposed to H2O2, accompanied with an increased expression of antiapoptotic proteins Bcl-2, Mcl-1, Nrf-2, and HO-1 and decreased proapoptotic proteins Bax, caspase 3, and Keap1, in comparison with naïve controls. Furthermore, hfPMSCs-CM (passage 3) collected from cultures exposed an inhibition of the Nrf2/Keap1/ARE signaling pathway which led to a significant reduction in caspase 3 expression in A549 cells, although the addition of Nrf2 inhibitor ML385 had no effect on the antioxidative activity of hfPMSCs-CM. These data clearly suggested that hfPMSCs protected the H2O2-induced cell oxidative injury at least in part by regulating the Nrf2-Keap1-ARE signaling-mediated cell apoptosis. Our study thus provided a new insight into the antioxidative mechanism and novel functions of hfPMSCs as antioxidants in disease treatments, which is warranted for further investigations.