Adsorption dynamics of ethane from air in structured fixed beds with different microfibrous composites

Adsorption dynamics of ethane in two granular fixed beds and structured fixed beds with microfibrous composites was studied.5A zeolite membrane 5A/PSSF(paper-like sintered stainless steel fiber)and microfibrous entrapped activated carbon(MEAC)composites were prepared by wet layup papermaking/sintering technique and in-situ hydrothermal method.Microfibrous composites were characterized by X-ray diffraction,scanning electron microscopy and N2 adsorption/desorption.Structured fixed beds were designed by filling granular adsorbents(5A zeolite or activated carbon)and microfibrous composites at the inlet and outlet of the beds,respectively.Effects of flow rate,bed height and structure on the breakthrough curves were investigated.The length of unused bed(LUB)was determined,and Yoon–Nelson model was used to fit the breakthrough curves.The experimental results showed ethane was effectively adsorbed on the granular adsorbents and microfibrous composites.Both composites could decrease the LUB values and enhance bed utilization.All breakthrough curves fitted well to Yoon–Nelson model,with correlation coefficient exceeding 0.89.The adsorption rate of ethane could be improved in the structured fixed beds,which showed an enhanced mass transfer efficiency for ethane adsorption.LUB values of structured fixed beds with 5A/PSSF composites were larger,the bed utilization values were lower,and the adsorption rate constants were higher than those with MEAC composites under the same conditions.

Nicotiana benthamiana XYLEM CYSTEINE PROTEASE genes facilitate tracheary element formation in interfamily grafting

Grafting is a plant propagation technique widely used in agriculture.A recent discovery of the capability of interfamily grafting in Nicotiana has expanded the potential combinations of grafting.In this study,we showed that xylem connection is essential for the achievement of interfamily grafting and investigated the molecular basis of xylem formation at the graft junction.Transcriptome and gene network analyses revealed gene modules for tracheary element(TE)formation during grafting that include genes associated with xylem cell differentiation and immune response.The reliability of the drawn network was validated by examining the role of the Nicotiana benthamiana XYLEM CYSTEINE PROTEASE(NbXCP)genes in TE formation during interfamily grafting.Promoter activities of NbXCP1 and NbXCP2 genes were found in differentiating TE cells in the stem and callus tissues at the graft junction.Analysis of a Nbxcp1;Nbxcp2 loss-of-function mutant indicated that NbXCPs control the timing of de novo TE formation at the graft junction.Moreover,grafts of the NbXCP1 overexpressor increased the scion growth rate as well as the fruit size.Thus,we identified gene modules for TE formation at the graft boundary and demonstrated potential ways to enhance Nicotiana interfamily grafting.

Overview of Biomass Conversion to Electricity and Hydrogen and Recent Developments in Low-Temperature Electrochemical Approaches

Biomass is plant or animal material that stores both chemical and solar energies,and that is widely used for heat production and various industrial processes.Biomass contains a large amount of the element hydrogen,so it is an excellent source for hydrogen production.Therefore,biomass is a sustainable source for electricity or hydrogen production.Although biomass power plants and reforming plants have been commercialized,it remains a difficult challenge to develop more effective and economic technologies to further improve the conversion efficiency and reduce the environmental impacts in the conversion process.The use of biomass-based flow fuel cell technology to directly convert biomass to electricity and the use of electrolysis technology to convert biomass into hydrogen at a low temperature are two new research areas that have recently attracted interest.This paper first briefly introduces traditional technologies related to the conversion of biomass to electricity and hydrogen,and then reviews the new developments in flow biomass fuel cells(FBFCs)and biomass electrolysis for hydrogen production(BEHP)in detail.Further challenges in these areas are discussed.

Chloromycetin resistance of clinically isolated E coli is conversed by using EGS technique to repress the Chloromycetin acetyl transferase

AIM: To explore the possibility of repression of chloromycetin (Cm) acyl transferase by using external guided sequence (EGS) in order to converse the clinical Ecoli isolates from Cm- resistant to Cm- sensitive.METHODS: EGS directed against chloromycetin acetyl transferase gene (cat) was cloned to vector pEGFP-C1 which contains the kanamycin (Km) resistance gene.The recombinant plasmid pEGFP-C1+EGScat1+cat2 was constructed and the blank vector without EGS fragment was used as control plasmids. By using the CaCl2 transformation method, the recombinant plasmids were introduced into the clinically isolated Cm resistant but Km sensitive E colistrains. Transformants were screened on LB agar plates containing Km. Extraction of plasmids and PCR were applied to identify the positive clones.The growth curve of EGS transformed bacteria cultured in broth with Cm resistance was determined by using spectrophotometer at A600. Drug sensitivity was tested in solid culture containing Cm by using KB method.RESULTS: Transformation studies were carried out on 16 clinically isolated Cm-resistant (250 μg/mLof Cm) E colistrains by using pEGFP-C1-EGScat1cat2 recombinant plasmid. Transformants were screened on LB-agar plates containing Km after the transformation using EGS.Of the 16 tested strains, 4 strains were transformed successfully. Transformants with EGS plasmid showed growth inhibition when grown in liquid broth culture containing 200 μg/mL of Cm. In drug sensitivity test,these strains were sensitive to Cm on LB-agar plates containing 200 μg/mL of Cm. Extraction of plasmids and PCR amplification showed the existence of EGS plasmids in these four transformed strains. These results indicated that the Cat of the four clinical isolates had been suppressed and the four strains were converted to Cm sensitive ones.CONCLUSION: The EGS directed against Cat is able to inhibit the expression of Cat, and hence convert Cmresistant bacteria to Cm-sensitive ones. Thus, the EGS has the capability of converting the phenotype of clinical drug-resistant isolates strains to drug-sensitive ones.

Anisotropic and asymmetric deformation mechanisms of nanolaminated graphene/Cu composites

We conducted molecular dynamics (MD) simulations of tension and compression along the <112> direction and MD simulations of compression along the <110> and <111> directions on nanolaminated graphene/Cu (NGCu) composites to investigate the effects of the incorporated graphene and the deformation mechanisms related to the loading direction. The deformation behavior and the defect structures were found to be strongly dependent on the loading conditions. An asymmetric tension-compression deformation behavior was thus found in graphene/Cu nanolaminates under the <112> loading, which was dominated by stacking faults and deformation twins formed by dislocation slide under tension and compression, respectively. High density and ordered nanotwins were formed at the graphene/Cu interfaces. Two different formation mechanisms of the twins were found under the <112> compression, and the nucleated twins were easy to be thickened with the assistance of the graphene wrinkles. Multiple twins were formed under the <110> compression by the dislocation cross-slip. This study provides a way to introduce graphene reinforcement and twin boundary to Cu matrix composites and design nanotwinned graphene/Cu composites with excellent mechanical performance.

Characterization of Soil Bacterial Diversity in Relation to Irrigation Water: A Case Study in China

Use of wastewater for irrigation has become indispensable worldwide due to accelerating water scarcity, and it also carries a social dimension of poverty reduction in developing countries. However, the impacts of wastewater irrigation on soil properties are still insufficiently understood, especially with regard to change in soil microbial community characteristics. The present study presents an assessment of soil bacterial communities subjecting to different irrigation waters. We conducted soil sampling in farmlands irrigated with wastewater, river water and groundwater respectively in an arid region of China and performed a metagenomic survey of microbial populations using the prokaryotic 16S ribosomal RAN gene. It sheds new light on possible alteration of soil bacterial diversity due to irrigation water. It also reveals that the relative abundance of nitrifying bacteria is greater in soil irrigated with river water than soil irrigated with wastewater. The opposite is true for denitrifying bacteria. The findings serve as a call for further in-depth study to explore the long-term responses of soil microbial communities to irrigation waters for the sake of environmentally sound watershed management.

Exploration of Activated Pathways for Improving Antifungal Agent FR901469 Productivity in Fungal Species No.11243 Using Comprehensive Pathway Model

Secondary metabolites are important for various industrial applications. The production of secondary metabolites is often improved by the activation of substrate supply pathways for biosynthesis. However, many important pathways have remained unclear. In this study, we explored possible pathways related to substrate supply for the biosynthesis of the antifungal agent FR901469 which is a nonribosomal peptide and a fungal secondary metabolite. To clarify the unknown activated pathways, we utilized the Comprehensive Pathway Model (CPM) which was developed in our previous study. We verified that the overexpression of the hypothetical beta-alanine-aminotransferase (BAL-AT), which was included in the explored pathways, improved the FR901469 productivity. The genes encoding the BAL metabolic enzymes are considered to be important for improving the FR901469 productivity.

Development of an Algorithm for Reconstructing a Comprehensive Pathway Model: Application to <i>Saccharomyces cerevisiae</i>

The generation of bioactive products by microbial bioprocesses is important for drug discovery, functional food development, and other beneficial purposes. Many pathways contribute to the production of these bioactive compounds, but important knowledge for improving productivity still remains in hidden pathways. Recently, an abundance of knowledge about metabolic pathways has been accumulated in metabolic pathway databases, such as BioCyc and KEGG. Many by-products are chemically transformed and actually used in other enzymatic reactions. In this work, we developed an algorithm for the reconstruction of a comprehensive genetic pathway model from a known metabolic pathway database. This model considers the interactions of the by-products, in addition to the main products. Furthermore, we developed a method for the construction of a comprehensive pathway model in a specific organism. In this study, we reconstructed a Saccharomyces cerevisiae model. From this model, the pathways among enzymes that contributed to galactose metabolism were explored. Using S. cerevisiae DNA microarray data, the activated pathways were found among the explored pathways.

Liquid metal compartmented by polyphenol-mediated nanointerfaces enables high-performance thermal management on electronic devices

The exponentially increasing heat generation in electronic devices,induced by high power density and miniaturization,has become a dominant issue that affects carbon footprint,cost,performance,reliability,and lifespan.Liquid metals(LMs)with high thermal conductivity are promising candidates for effective thermal management yet are facing pump-out and surface-spreading issues.Confinement in the form of metallic particles can address these problems,but apparent alloying processes elevate the LM melting point,leading to severely deteriorated stability.Here,we propose a facile and sustainable approach to address these challenges by using a biogenic supramolecular network as an effective diffusion barrier at copper particle-LM(EGaIn/Cu@TA)interfaces to achieve superior thermal conduction.The supramolecular network promotes LM stability by reducing unfavorable alloying and fluidity transition.The EGaIn/Cu@TA exhibits a record-high metallic-mediated thermal conductivity(66.1 W m^(-1) K^(-1))and fluidic stability.Moreover,mechanistic studies suggest the enhanced heat flow path after the incorporation of copper particles,generating heat dissipation suitable for computer central processing units,exceeding that of commercial silicone.Our results highlight the prospects of renewable macromolecules isolated from biomass for the rational design of nanointerfaces based on metallic particles and LM,paving a new and sustainable avenue for high-performance thermal management.

Biomass gasification,catalytic technologies and energy integration for production of circular methanol:New horizons for industry decarbonisation

The Intergovernmental Panel on Climate Change(IPCC)recognises the pivotal role of renewable energies in the future energy system and the achievement of the zero-emission target.The implementation of renewables should provide major opportunities and enable a more secure and decentralised energy supply system.Renewable fuels provide long-term solutions for the transport sector,particularly for applications where fuels with high energy density are required.In addition,it helps reducing the carbon footprint of these sectors in the long-term.Information on biomass characteristics feedstock is essential for scaling-up gasification from the laboratory to industrial-scale.This review deals with the transformation biogenic residues into a valuable bioenergy carrier like biomethanol as the liquid sunshine based on the combination of modified mature technologies such as gasification with other innovative solutions such as membranes and microchannel reactors.Tar abatement is a critical process in product gas upgrading since tars compromise downstream processes and equipment,for this,membrane technology for upgrading syngas quality is discussed in this paper.Microchannel reactor technology with the design of state-of-the-art multifunctional catalysts provides a path to develop decentralised biomethanol synthesis from biogenic residues.Finally,the development of a process chain for the production of(i)methanol as an intermediate energy carrier,(ii)electricity and(iii)heat for decentralised applications based on biomass feedstock flexible gasification,gas upgrading and methanol synthesis is analysed.

Mycelium as a self-growing biobased material for the fabrication of single-layer masks

Disposable face masks are an essential piece of personal protective equipment for workers in medical facilities,laboratories,and the general public to prevent the spread of illnesses and/or contamination.Covid-19 resulted in an uptick in the usage and production of face masks,exacerbating issues related to the waste and recycling of these materials.Traditionally,face masks are derived from petrochemicals,such as melt-blown or spunbound polypropylene.As such,there is a need to find sustainable mask materials that can maintain or improve the performance of petrochemical masks.This paper explores an alternative mask material that utilizes fungal mycelium as self-growing filaments to enhance the efficiency of individual polypropylene mask layers.By engineering the growth pattern and time,breathability and filtration efficiency was optimized such that one layer of the mycelium-modified mask could replace all three layers of the traditional three-layer mask.Additionally,it was found that the mycelium-modified mask exhibits asymmetric hydrophobicity,with super-hydrophobicity at the composite-air interface and lower hydrophobicity at the composite-medium interface.This property can improve the performance of the modified mask by protecting the mask from external liquids without trapping water vapor from the user’s breath.The findings from this study can provide a basis for further development of mycelium to create sustainable filtration materials with enhanced functionality.

Near infrared light-induced dynamic modulation of enzymatic activity through polyphenol-functionalized liquid metal nanodroplets

Dynamic manipulation of enzymatic activity is a challenging task for applications in chemical and pharmaceutical industries due to the difficult modification and variable conformation of various enzymes.Here, we report a new strategy for reversible dynamic modulation of enzymatic activity by near-infrared light-induced photothermal conversion based on polyphenol-functionalized liquid metal nanodroplets(LM). The metal-phenolic nanocoating not only provides colloidal stability of LM nanodroplets but also generates nanointerfaces for the assembly of various enzymes on the LM nanodroplets. Upon near infrared(NIR) irradiation, the localized microenvironmental heating through photothermal effect of the LM nanodroplets allows tailoring the enzymatic activity without affecting the bulk temperature. A library of functional enzymes, including proteinase K, glucoamylase, glucose oxidase, and Bst DNA polymerase, is integrated to perform a reversible control and enhanced activities even after five times of cycles, demonstrating great potential in bacterial fermentation, bacteriostasis, and target gene amplification.

A biologically stable, self-catalytic DNAzyme machine encapsulated by metal-phenolic nanoshells for multiple microRNA imaging

DNAzyme machines play critical roles in the fields of cell imaging, disease diagnosis, and cancer therapy. However, the applications of DNAzyme machines are limited by the nucleases-induced degradation,non-specific binding of proteins, and insufficient provision of cofactors. Herein, protected DNAzyme machines with different cofactor designs(referred to as Pro Ds) were nanoengineered by the construction of multifunctional metal-phenolic nanoshells to deactivate the interferential proteins, including nucleases and non-specific binding proteins. Moreover, the nanoshells not only facilitate the cellular internalization of Pro Ds but provide specific metal ions acting as cofactors of the designed DNAzymes. Cellular imaging results demonstrated that Pro Ds could effectively and simultaneously monitor multiple tumor-related micro RNAs in living cells. This facile and rapid strategy that encapsulates DNAzyme machines into the protective metal-phenolic nanoshells is anticipated to extend to a wide range of functional nucleic acidsbased biomedical applications.

Nanocellulose-based porous materials: Regulation and pathway to commercialization in regenerative medicine

We review the recent progress that have led to the development of porous materials based on cellulose nanostructures found in plants and other resources. In light of the properties that emerge from the chemistry, shape and structural control, we discuss some of the most promising uses of a plant-based material, nanocellulose, in regenerative medicine. Following a brief discussion about the fundamental aspects of self-assembly of nanocellulose precursors, we review the key strategies needed for material synthesis and to adjust the architecture of the materials (using three-dimensional printing, freeze-casted porous materials, and electrospinning) according to their uses in tissue engineering, artificial organs, controlled drug delivery and wound healing systems, among others. For this purpose, we map the structure-property-function relationships of nanocellulose-based porous materials and examine the course of actions that are required to translate innovation from the laboratory to industry. Such efforts require attention to regulatory aspects and market pull. Finally, the key challenges and opportunities in this nascent field are critically reviewed.

Consequences of coinfection with protective symbionts on the host phenotype and symbiont titres in the pea aphid system

Symbiotic associations between microbes and insects are widespread, and it is frequent that several symbionts share the same host individual. Hence, interactions can occur between these symbionts, influencing their respective abundance within the host with consequences on its phenotype. Here, we investigate the effects of multiple infections in the pea aphid, Acyrthosiphon pisurn, which is the host of an obligatory and several facultative symbionts. In particular, we study the influence of a coinfection with 2 protective symbionts： Harniltonella defensa, which confers protection against parasitoids, and Rickettsiella viridis, which provides protection against fungal pathogens and predators. The effects of Hamiltonella-Rickettsiella coinfection on the respective abundance of the symbionts, host fitness and efficacy of enemy protection were studied. Asymmetrical interactions between the 2 protective symbionts have been found： when they coinfect the same aphid individuals, the Rickettsiella infection affected Hamiltonella abundance within hosts but not the Hamiltonella-mediated protective phenotype while the Hamiltonella infection negatively influences the Rickettsiella-mediated protective phenotype but not its abundance. Harboring the 2 protective symbionts also reduced the survival and fecundity of host individuals. Overall, this work highlights the effects of multiple infections on symbiont abundances and host traits that are likely to impact the maintenance of the symbiotic associations in natural habitats.

基于基因组信息指导的古菌培养新策略

古菌、细菌及真核生物共同组成了地球上的三域生命体系.其中古菌域不仅包含了现今地球上最古老的生命类群,如产甲烷古菌;同时,阿斯加德(Asgard)古菌超门还被认为是真核生物的共同祖先.近些年来,随着地球科学和生命科学交叉研究日益加深,科学家发现古菌在地球化学元素循环中也起到了显著作用.通过不依赖于纯培养的高通量测序技术分析,表明古菌具有丰富的物种多样性,现已发现超过20个全新的古菌门.然而,目前仅在其中4个古菌门中获得了纯培养菌株,对古菌生理特征、起源与演化以及生态功能的认识也受到纯培养古菌菌株稀缺的限制,无法通过实验验证环境中未培养古菌基因组所预测到的功能基因.在本综述中,简述了古菌的发现与研究进展,对比了未培养和纯培养古菌之间的差距,并呼吁将更多的努力和科研资源投入到古菌分离和纯培养工作中.文章还概述了基于大量未培养古菌基因组指导分离和纯培养的新思路和新策略,即:基因组功能预测、代谢互作网络构建、基因组水平代谢建模、机器学习预测培养条件,期望能够使用现代高通量测序技术所积累的未培养古菌基因组数据来帮助获得更多新的纯培养古菌菌株.

Bacterial communities in different locations, seasons and segments of a dairy wastewater treatment system consisting of six segments

A dairy wastewater treatment system composed of the 1st segment（no aeration） equipped with a facility for the destruction of milk fat particles, four successive aerobic treatment segments with activated sludge and a final sludge settlement segment was developed. The activated sludge is circulated through the six segments by settling sediments（activated sludge） in the 6th segment and sending the sediments beck to the 1st and 2nd segments.Microbiota was examined using samples from the non-aerated 1st and aerated 2nd segments obtained from two farms using the same system in summer or winter. Principal component analysis showed that the change in microbiota from the 1st to 2nd segments concomitant with effective wastewater treatment is affected by the concentrations of activated sludge and organic matter（biological oxygen demand [BOD]）, and dissolved oxygen（DO） content. Microbiota from five segments（1st and four successive aerobic segments） in one location was also examined. Although the activated sludge is circulating throughout all the segments, microbiota fluctuation was observed. The observed successive changes in microbiota reflected the changes in the concentrations of organic matter and other physicochemical conditions（such as DO）, suggesting that the microbiota is flexibly changeable depending on the environmental condition in the segments. The genera Dechloromonas, Zoogloea and Leptothrix are frequently observed in this wastewater treatment system throughout the analyses of microbiota in this study.

Thermomemory in shoot apical meristem: Regulation of carbohydrate metabolism and stem cell identity

Adaptation to the environment is essential for sessile organisms,such as plants,as they cannot move away from adverse conditions.Heat stress(HS)is one of the most serious environmental stresses in terms of its effect on crop growth and yield,especially in this era of global warming.Therefore,research on heat re-sponses and acclimation in plants is becoming increasingly important.Plants have evolved complex systems to respond to HS for their survival.In general,heat shock transcription factors(Hsfs)are involved in the acquisition of thermotolerance.

Tuning porosity of coal-derived activated carbons for CO_(2) adsorption

A simple method was developed to tune the porosity of coal-derived activated carbons,which provided a model adsorbent system to investigate the volumetric CO_(2)adsorption performance.Specifically,the method involved the variation of the activation temperature in a K2CO3 induced chemical activation process which could yield activated carbons with defined microporous(<2 nm,including ultra-microporous<1 nm)and meso-microporous structures.CO_(2)adsorption isotherms revealed that the microporous activated carbon has the highest measured CO_(2)adsorption capacity(6.0 mmol∙g^(–1)at 0℃and 4.1 mmol∙g^(-1)at 25℃),whilst ultra-microporous activated carbon with a high packing density exhibited the highest normalized capacity with respect to packing volume(1.8 mmol∙cm−3 at 0℃and 1.3 mmol∙cm^(–3)at 25℃),which is significant.Both experimental correlation analysis and molecular dynamics simulation demonstrated that(i)volumetric CO_(2)adsorption capacity is directly proportional to the ultra-micropore volume,and(ii)an increase in micropore sizes is beneficial to improve the volumetric capacity,but may lead a low CO_(2)adsorption density and thus low pore space utilization efficiency.The adsorption experiments on the activated carbons established the criterion for designing CO_(2)adsorbents with high volumetric adsorption capacity.

Alloyed nanostructures integrated metal-phenolic nanoplatform for synergistic wound disinfection and revascularization

New materials for combating bacteria-caused infection and promoting the formation of microvascular networks during wound healing are of vital importance.Although antibiotics can be used to prevent infection,treatments that can disinfect and accelerate wound healing are scarce.Herein,we engineer a coating that is both highly compatible with current wound dressing substrates and capable of simultaneously disinfecting and revascularizing wounds using a metal-phenolic nanoplatform containing an alloyed nanostructured architecture(Ag@Cu-MPNNC).The alloyed nanostructure is formed by the spontaneous co-reduction and catalytic disproportionation reaction of multiple metal ions on a foundation metal-phenolic supramolecular layer.This synergistic presence of metals greatly improves the antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria,while demonstrating negligible cytotoxicity to normal tissue.In infected rat models,the Ag@Cu-MPNNC could kill bacteria efficiently,promoting revascularization and accelerate wound closure with no adverse side effects in infected in vivo models.In other words,this material acts as a combination therapy by inhibiting bacterial invasion and modulating bio-nano interactions in the wound.