Inorganic Substrates Research Articles

Culexarchaeia, a novel archaeal class of anaerobic generalists inhabiting geothermal environments

Geothermal environments, including terrestrial hot springs and deep-sea hydrothermal sediments, often contain many poorly understood lineages of archaea. Here, we recovered ten metagenome-assembled genomes (MAGs) from geothermal sediments and propose that they constitute a new archaeal class within the TACK superphylum, “Candidatus Culexarchaeia”, named after the Culex Basin in Yellowstone National Park. Culexarchaeia harbor distinct sets of proteins involved in key cellular processes that are either phylogenetically divergent or are absent from other closely related TACK lineages, with a particular divergence in cell division and cytoskeletal proteins. Metabolic reconstruction revealed that Culexarchaeia have the capacity to metabolize a wide variety of organic and inorganic substrates. Notably, Culexarchaeia encode a unique modular, membrane associated, and energy conserving [NiFe]-hydrogenase complex that potentially interacts with heterodisulfide reductase (Hdr) subunits. Comparison of this [NiFe]-hydrogenase complex with similar complexes from other archaea suggests that interactions between membrane associated [NiFe]-hydrogenases and Hdr may be more widespread than previously appreciated in both methanogenic and non-methanogenic lifestyles. The analysis of Culexarchaeia further expands our understanding of the phylogenetic and functional diversity of lineages within the TACK superphylum and the ecology, physiology, and evolution of these organisms in extreme environments.

Flexible ferroelectric Pb(Zr0.53Ti0.47)O3 epitaxial films with large radiation and high-temperature tolerance

Radiation and temperature hardness are important for electronic devices operating in harsh environments such as modern medical equipment, outer space, and nuclear energy industries. In this work, we report radiation and temperature-hardened flexible ferroelectric Pb(Zr0.53Ti0.47)O3 epitaxial films that were grown on flexible inorganic mica substrates via van der Waals heteroepitaxy and can be further used for building high-performance electronic devices. We systematically investigated the effect of 60Co-gamma radiation and temperature on the ferroelectric properties of Pb(Zr0.53Ti0.47)O3 films and their flexibility as well. Pb(Zr0.53Ti0.47)O3 films exhibit a radiation and temperature tolerance of up to 20 Mrad and 175 °C, respectively. In particular, the 20 Mrad-irradiated Pb(Zr0.53Ti0.47)O3 film has an excellent retention even after 105 s with extrapolate retention time longer than 10 years and polarization fatigue up to 1010 cycles as well as moderate flexibility and bending stability after bending 105 cycles. Furthermore, we identified that the degradation of macroscopic ferroelectric properties of irradiated Pb(Zr0.53Ti0.47)O3 films originates from the ferroelectric domain pinning effect induced by the ionization effect. Our work demonstrates that flexible ferroelectric Pb(Zr0.53Ti0.47)O3 films are promising for developing novel flexible electronic devices for applications in harsh environments.

Engineering Bio-Adhesives Based on Protein-Polysaccharide Phase Separation.

Glue-type bio-adhesives are in high demand for many applications, including hemostasis, wound closure, and integration of bioelectronic devices, due to their injectable ability and in situ adhesion. However, most glue-type bio-adhesives cannot be used for short-term tissue adhesion due to their weak instant cohesion. Here, we show a novel glue-type bio-adhesive based on the phase separation of proteins and polysaccharides by functionalizing polysaccharides with dopa. The bio-adhesive exhibits increased adhesion performance and enhanced phase separation behaviors. Because of the cohesion from phase separation and adhesion from dopa, the bio-adhesive shows excellent instant and long-term adhesion performance for both organic and inorganic substrates. The long-term adhesion strength of the bio-glue on wet tissues reached 1.48 MPa (shear strength), while the interfacial toughness reached ~880 J m−2. Due to the unique phase separation behaviors, the bio-glue can even work normally in aqueous environments. At last, the feasibility of this glue-type bio-adhesive in the adhesion of various visceral tissues in vitro was demonstrated to have excellent biocompatibility. Given the convenience of application, biocompatibility, and robust bio-adhesion, we anticipate the bio-glue may find broad biomedical and clinical applications.

New MCRs in Ionic Liquid: Green Synthesis and Biological Activity Investigation of New Pyrazoloazepines: Application of Ag/Fe3O4/CdO@MWCNT MNCs in Reduction of Organic Pollutant

In this research we have synthesized new derivatives of dihydrobenzopyrazoloazepine in high yields using multicomponent reaction of anilines, oxalylchloride, alkyl bromides, activated acetylenic compounds, and hydrazine in the presence of Ag/Fe3O4/CdO@MWCNTs MNCs as a high-performance catalyst in ionic liquid at room temperature. The Ag/Fe3O4/CdO@MWCNTs MNCs were synthesized using ionic liquid 1-Octhyl-3-methyl imidazolium bromide ([OMIM]Br) as a stabilizer and soft template. Because of having NH group in the synthesized compounds, the antioxidant property of some synthesized dihydrobenzopyrazoloazepine was investigated by diphenyl-picrylhydrazine (DPPH) radical trapping and power of ferric reduction experiment. Also, the catalytic activity of the green synthesized Ag/Fe3O4/CdO@MWCNTs MNCs was evaluated in the reduction of organic pollutants, such as 4-nitrophenol (4-NP) in water under mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for removing organic pollutants within a few seconds. A short time of reaction, high yields of product and easy separation of catalyst and products are some advantages of this procedure. HIGHLIGHTS Ionic liquids (ILs) are one of the important examples of green solvents with the capacity to solvate an array of inorganic and organic substrates and vanishingly small vapor pressures. ‘ILs are promising substitutes for volatile organic solvents (VOCs).’ The present procedure avoids the use of toxic solvents. Benzazepines, which have a seven-membered aza-heterocyclic fused aromatic ring, are of interest because of their biological activity and use as building blocks for natural product synthesis and drug discovery.

Determinants, maintenance, and function of organellar pH.

The protonation state of soluble and membrane-associated macromolecules dictates their charge, conformation, and functional activity. In addition, protons (H+ or their equivalents) partake in numerous metabolic reactions and serve as a source of electrochemical energy to drive the transmembrane transport of both organic and inorganic substrates. Stringent regulation of the intracellular pH is therefore paramount to homeostasis. Although the regulation of the cytosolic pH has been studied extensively, our understanding of the determinants of the H+ concentration ([H+]) of intracellular organelles has developed more slowly, limited by their small size and inaccessibility. Recently, however, targeting of molecular probes to the organellar lumen together with advances in genomic, proteomic, and electrophysiological techniques have led to the identification and characterization of unique pumps, channels, and transporters responsible for the establishment and maintenance of intraorganellar pH. These developments and their implications for cellular function in health and disease are the subject of this review.

Decreased temperature sensitivity of soil respiration induced by warming slowed topsoil carbon turnover in a semi-arid grassland

The carbon feedback between soil and climate is partly determined by topsoil organic carbon turnover time (τ). However, the τ under future warmer climate still remains unclear. Herein, a manipulative experiment was conducted in a semi-arid grassland on the Loess Plateau of China to investigate the underlying mechanisms of the response of topsoil τ to warming. The results showed that warming significantly increased topsoil τ, which was directly regulated by the decreased temperature sensitivity of soil microbial respiration and indirectly due to the decreased pH and the increased aboveground biomass, soil inorganic nitrogen and soil carbon substrate quality. These results implied that short-term warming could potentially promote soil carbon sequestration in the semi-arid grassland.

Revealing the cathode electrolyte interphase on Li- and Mn-rich materials by in-situ electrochemical atomic force microscopy

Solid electrolyte interphase (SEI) grown on electrode surfaces during charge-discharge processes plays a key role in the cycle performance of lithium-ion batteries. In-situ study of cathode electrolyte interphase (CEI) is challenging due to the complicated interfacial reactions on the cathode materials including gas formation and the formation of thin CEI film. Herein, we applied the electrochemical atomic force microscope (EC-AFM) to study the interfacial changes in high energy density Li- and Mn-rich (LMR) materials with an F-rich electrolyte (1 M LiPF6 FEC/FEMC/HFE). The study indicated that the electrolyte formed a uniform and dense passivation CEI film on the LMR material surface at high voltage. The CEI is composed of inorganic LiF substrate as confirmed by X-ray photoelectron spectroscopy (XPS). The assembled battery (LMR||Li) shows an excellent cycle performance and maintains capacity at 85.5% after 100 cycles, compared to the 13.7% retention rate of commercial carbonate electrolyte (1 M LiPF6 EC/EMC/DMC).

Towards sustainable CO2 electrochemical transformation via coupling design strategy

CO2 is a notorious greenhouse gas, but it is also an abundant, non-toxic, and sustainable C1 source. CO2 electrochemical transformation (CO2ET) is an effective way to close the artificial carbon cycle. Coupling design strategies guided by green chemistry are widely utilized in CO2ET because they can effectively optimize chemical performance, economic feasibility, and sustainability. The current review presents recent advances of coupling strategies in a progressively macroscopic view: from co-electrodes, counter electrodes to carbon capture, utilization and storage (CCUS) processes. Specifically, this review summarizes the coupling design in the electro-organic conversion of CO2, including co-electrolysis with organic and inorganic substrates at the cathode. We also discuss the coupling of CO2ET with paired anodic oxidation reactions. Literarily available anodic substrates contain chlorine compounds, biomass derivatives, alcohols, and amines. In addition, existing applications of coupling strategies in CO2ET processes are summarized, including coupling with capture-media, multi-physical fields, and product utilization. Finally, the challenges encountered in the coupling design strategy are presented, and future developments are envisioned.

Polyaniline-based room temperature ammonia gas sensor employing hybrid organic-inorganic substrate

Air pollution poses a serious threat to public health, and gas sensors for detection of the pollution has gained great attention over the past decades. In this work, a novel idea based on the substrate material integrated by structure and function was built to prepare NH3 sensor with an improving sensing properties. Hybrid organic–inorganic sol gel with methacryloxy and epoxy groups was first synthesized. A hybrid organic–inorganic substrate was then prepared based on continuous condensation, radical polymerization and anionic polymerization. The thermal stability and microstructural of the hybrid substrate were studied and the results indicated that the hybrid has excellent thermal and structural stability. Then, polyaniline (PANI) was directly loaded on the hybrid substrate due to hydrogen bonding though a facile in-situ polymerization method to fabricate a PANI/hybrid nanocomposite for NH3 sensing. The hydroxyl groups generated from the epoxide ring-open reaction and silane hydrolysis condensation contribute to improve the sensing properties. This sensor showed superior selectivity and reproducibility to 50 ppm NH3 at room temperature. The low detection limit towards NH3 at room temperature can reach 1 ppm. This strategy may provide a promising and straightforward method in gas sensing electronics at room temperature.

Ceramic supported composite nanofiltration membrane via a PDA interlayer induced mineralization of TiO2

Inorganic membrane has good stability, which acts as a significant role in water treatment. However, the effective preparation of stable and defect-free nanofiltration membranes on inorganic substrate remains challenge. In this paper, ceramic supported composite nanofiltration membrane (CNM) was prepared by mineralization of TiO2 polymeric sol induced by a polydopamine (PDA) interlayer on ceramic ultrafiltration substrate at low temperature. FESEM analysis shows that a PDA interlayer with a thickness of ∼44 nm and a smooth and dense top layer with a thickness of ∼88 nm are formed. And the construction and chemical changes of the membrane layer are confirmed by XPS and FTIR analyses. The water contact angle and zeta potential characterizations show that the CNM has a hydrophilic surface and a positive charge property. The obtained CNM has a polyethylene glycol (PEG) molecular weight cut-off (MWCO) of 800 Da. The CNM prepared with polymeric sol size less than 10 nm has a higher rejection to divalent salt. At 0.6 MPa, the CaCl2 rejection is 91.5% and the permeation flux is 22.8 L m−2 h−1. In 50 h continuous filtration, the rejection rate changes little. This paper describes a facile and efficient approach for producing stable ceramic supported composite nanofiltration membranes, which has potential applications in water treatment.

Modulation of the electronic state of carbon thin films by inorganic substrates

The control of the electronic states of carbon-based materials is of great importance for the widespread use of carbon materials as electronic devices and catalysts. This article reports a novel method of controlling the electronic states of carbon-based materials by establishing covalent bonds between inorganic support materials and carbon thin films. Carbon thin films of 1 nm thickness were grown on inorganic substrates (Al2O3, AlN, and ZrO2) using chemical vapor deposition. Covalent bond formation was confirmed between the substrates and the carbon films. The investigations of field effect transistor characteristics and work function revealed the different relationships between the Dirac points and Fermi levels of carbon films depending on the type of substrate. The Fermi level of the films grown on Al2O3 or ZrO2 was found to be lower than the Dirac point energy level, with the ZrO2 sample exhibiting the lowest Fermi level. In contrast, the Fermi level of the film grown on AlN was located at a higher energy than the Dirac point. The Fermi level of the carbon film depends on the inorganic substrate, and the change in the Fermi level can be explained by the nature of the covalent bonds between the substrate and the film.

Role of Adatoms for the Adsorption of F4TCNQ on Au(111).

Organic adlayers on inorganic substrates often contain adatoms, which can be incorporated within the adsorbed molecular species, forming two-dimensional metal–organic frameworks at the substrate surface. The interplay between native adatoms and adsorbed molecules significantly changes various adlayer properties such as the adsorption geometry, the bond strength between the substrate and the adsorbed species, or the work function at the interface. Here, we use dispersion-corrected density functional theory to gain insight into the energetics that drive the incorporation of native adatoms within molecular adlayers based on the prototypical, experimentally well-characterized system of F4TCNQ on Au(111). We explain the adatom-induced modifications in the adsorption geometry and the adsorption energy based on the electronic structure and charge transfer at the interface.

Diversity and distribution of sulfur metabolic genes in the human gut microbiome and their association with colorectal cancer

BackgroundRecent evidence implicates microbial sulfidogenesis as a potential trigger of colorectal cancer (CRC), highlighting the need for comprehensive knowledge of sulfur metabolism within the human gut. Microbial sulfidogenesis produces genotoxic hydrogen sulfide (H2S) in the human colon using inorganic (sulfate) and organic (taurine/cysteine/methionine) substrates; however, the majority of studies have focused on sulfate reduction using dissimilatory sulfite reductases (Dsr).ResultsHere, we show that genes for microbial sulfur metabolism are more abundant and diverse than previously observed and are statistically associated with CRC. Using ~ 17,000 bacterial genomes from publicly available stool metagenomes, we studied the diversity of sulfur metabolic genes in 667 participants across different health statuses: healthy, adenoma, and carcinoma. Sulfidogenic genes were harbored by 142 bacterial genera and both organic and inorganic sulfidogenic genes were associated with carcinoma. Significantly, the anaerobic sulfite reductase (asr) genes were twice as abundant as dsr, demonstrating that Asr is likely a more important contributor to sulfate reduction in the human gut than Dsr. We identified twelve potential pathways for reductive taurine metabolism and discovered novel genera harboring these pathways. Finally, the prevalence of metabolic genes for organic sulfur indicates that these understudied substrates may be the most abundant source of microbially derived H2S.ConclusionsOur findings significantly expand knowledge of microbial sulfur metabolism in the human gut. We show that genes for microbial sulfur metabolism in the human gut are more prevalent than previously known, irrespective of health status (i.e., in both healthy and diseased states). Our results significantly increase the diversity of pathways and bacteria that are associated with microbial sulfur metabolism in the human gut. Overall, our results have implications for understanding the role of the human gut microbiome and its potential contributions to the pathogenesis of CRC.D6EbGb2ro5gR7oXf6xaE6NVideo abstract

Development of Drip Flow Technique Hydroponic in Growing Cucumber

Hydroponics is a new branch and aspect of food crop growing that in recent years made its mark in developing country such as Nigeria. Although, its adoption has not been too encouraging. This research work aimed at developing a drip technique system of hydroponics in determination of the agronomic parameters of cucumber by comparing the yield, water and nutrient efficiency, its consumptive use and proximate and mineral composition of cucumber. The experiment was carried out in a complete randomized design with three treatments; organic substrate (coconut coir), inorganic substrate (styrofoam) and soil. These treatments were replicated five times. The vegetative growth (agronomic parameters), yield, water and nutrient, proximate and mineral composition were measured. The result showed the consumptive use as 0.0044 m3 per day and 0.3212 m3 as the water and nutrient use efficiency. The result also showed that organic substrate gave the highest mean plant height of 736.66 mm, highest mean stem diameter of 5.79 mm and highest mean number of leaves of 9.75 while inorganic substrate gave highest mean plant height, mean stem diameter and mean number of leaves as 336.28 mm, 4.95 mm and 7.68 respectively. Also, the highest result of control (soil) gave 301.23 mm, 5.47 mm and 7.06 for the mean plant height, stem diameter and number of leaves respectively. The yield of cucumber as compared with the different growing media showed that there is no significant difference between the growing media (Fcrit> Fcal) unless for the plant height and number of flowers having Fcrit less than Fcal. From these results, it is advisable that drip technique system should be embraced by farmers whose primary aim of farming is for leafy vegetables and non-leafy vegetables as seen in the increase in stem diameter and plant height in the organic substrate.

Tracing carbon and nitrogen microbial assimilation in suspended particles in freshwaters

The dynamic interactions between dissolved organic matter (DOM) and particulate organic matter (POM) are central in nutrient cycling in freshwater ecosystems. However, the molecular-level mechanisms of such interactions are still poorly defined. Here, we study spatial differences in the chemical (i.e., individual proteinaceous amino acids) and microbial (i.e., 16S rRNA) composition of suspended sediments in the River Chew, UK. We then applied a compound-specific stable isotope probing (SIP) approach to test the potential assimilation of 13C,15N-glutamate (Glu) and 15N-NO3− into proteinaceous biomass by particle-associated microbial communities over a 72-h period. Our results demonstrate that the composition of suspended particles is strongly influenced by the effluent of sewage treatment works. Fluxes and percentages of assimilation of both isotopically labelled substrates into individual proteinaceous amino acids showed contrasting dynamics in processing at each site linked to primary biosynthetic metabolic pathways. Preferential assimilation of the organic molecule glutamate and evidence of its direct assimilation into newly synthesised biomass was obtained. Our approach provides quantitative molecular information on the mechanisms by which low molecular weight DOM is mineralised in the water column compared to an inorganic substrate. This is paramount for better understanding the processing and fate of organic matter in aquatic ecosystems.

Self‐Assembly of Adjustable Micropatterned Graphene Oxide and Reduced Graphene Oxide on Porous Polymeric Surfaces

AbstractThe breath figure (BF) method is a simple technique for fabricating micropatterned surfaces but has been rarely studied using graphene oxide (GO) or reduced GO (rGO). Additionally, fabrication of GO or rGO micropatterned (MPGO or MPrGO) by the BF method focuses on smooth and dense inorganic substrates, and the investigation of adjusting the MPGO morphology has been limited. This research systematically studies self‐assembly of MPGO and MPrGO on the surface of two model porous polymers by the BF method and explores its potential applications for surface modification. It is found that the size range of the MPGO is 1–50 µm and that the structures can be adjusted by changing the process parameters. Specifically, under specific conditions, a uniform honeycomb MPGO is obtained. Surface characteristics demonstrate that the unique MPGO morphology alters the surface water contact‐angle from ≈65° to ≈100° and that MPrGO decreases the surface resistivity to 1–5 kΩ cm−2. Additionally, MPGO coating on a microfiltration membrane gives it a much greater permeability than GO coating without micropatterned morphology and antibiofilm properties. Overall, this study shows that MPGO and MPrGO with adjustable morphologies are easily obtained on polymeric surfaces, thus altering the surface properties and giving the polymers various potential applications.

Design and evaluation of gas fermentation systems for CO2 reduction to C2 and C4 fatty acids: Non-genetic metabolic regulation with pressure, pH and reaction time

Addressing the carbon emissions through microbial mediated fermentation is an emerging interest. Custom designed and fabricated gas fermentation (GF) systems were evaluated to optimize the headspace pressure, pH (6.5, 7.5, and 8.5), fermentation time, and substrate concentration by employing enriched homoacetogenic chemolithoautotrophs in non-genetic approach. Headspace pressure showed marked influence on the metabolic conversion of inorganic carbon to acetic and butyric acids with 26% higher productivity than the control (atmospheric pressure). Maximum volatile fatty acid (VFA) yield of 3.7 g/L was observed at alkaline pH (8.5) under 2 bar pressure at carbon load of 10 g/L, 96 h). Acetic (3.0 g/L) and butyric (0.7 g/L) acids were the major products upon conversion of 85% of the inorganic substrate. A better in-situ buffering (β = 0.048) at pH 8.5 along with higher reductive current (RCC: −4.4 mA) depicted better performance of GF towards CO2 reduction.

Super‐Robust Xanthine–Sodium Complexes on Au(111)

AbstractA widely accepted theory is that life originated from the hydrothermal environment in the primordial ocean. Nevertheless, the low desorption temperature from inorganic substrates and the fragileness of hydrogen‐bonded nucleobases do not support the required thermal stability in such an environment. Herein, we report the super‐robust complexes of xanthine, one of the precursors for the primitive nucleic acids, with Na. We demonstrate that the well‐defined xanthine–Na complexes can only form when the temperature is ≥430 K, and the complexes keep adsorbed even at ≈720 K, presenting as the most thermally stable organic polymer ever reported on Au(111). This work not only justifies the necessity of high‐temperature, Na‐rich environment for the prebiotic biosynthesis but also reveals the robustness of the xanthine–Na complexes upon the harsh environment. Moreover, the complexes can induce significant electron transfer with the metal as inert as Au and hence lift the Au atoms up.

Super-Robust Xanthine-Sodium Complexes on Au(111).

A widely accepted theory is that life originated from the hydrothermal environment in the primordial ocean. Nevertheless, the low desorption temperature from inorganic substrates and the fragileness of hydrogen-bonded nucleobases do not support the required thermal stability in such an environment. Herein, we report the super-robust complexes of xanthine, one of the precursors for the primitive nucleic acids, with Na. We demonstrate that the well-defined xanthine-Na complexes can only form when the temperature is ≥430 K, and the complexes keep adsorbed even at ≈720 K, presenting as the most thermally stable organic polymer ever reported on Au(111). This work not only justifies the necessity of high-temperature, Na-rich environment for the prebiotic biosynthesis but also reveals the robustness of the xanthine-Na complexes upon the harsh environment. Moreover, the complexes can induce significant electron transfer with the metal as inert as Au and hence lift the Au atoms up.

Carbon molecular sieve hollow fiber composite membrane derived from PMDA-ODA polyimide for gas separation

Carbon molecular sieve (CMS) membranes have excellent gas separation property over conventional polymeric membranes and superior anti-swelling property. PMDA-ODA polyimide has high thermal stability and good mechanical property. It has been extensively adopted as the precursor of CMS membrane. However, due to the insoluble nature, PMDA-ODA CMS membranes are limited to configurations like dense symmetric films or composite membranes using porous inorganic or metal substrates. In this work, CMS hollow fiber composite membranes based on an asymmetric PMDA-ODA hollow fiber were successfully prepared for the first time. The neat PMDA-ODA hollow fiber membrane was crosslinked by polyethyleneimine to alleviate pore collapsing during carbonization and then dip-coated by a PMDA-ODA PAA solution to seal the surface defects. The PDMA-ODA CMS composite hollow fiber membranes showed gas permeances of 93.4 GPU, 19.6 GPU, 6.5 GPU, and 4.7 GPU for CO2, O2, N2, and CH4, respectively, with an ideal selectivity of 14.4, 3.0, and 19.8 for CO2/N2, O2/N2, and CO2/CH4 gas pairs, respectively. The attractive gas separation property shows a great potential for industrial application.