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A magnetic field is generally considered to be incompatible with superconductivity as it tends to spin-polarize electrons and breaks apart the opposite-spin singlet superconducting Cooper pairs. Here, an experimental phenomenon is observed that an intriguing reemergent superconductivity evolves from a conventional superconductivity undergoing a hump-like intermediate phase with a finite electric resistance in the van der Waals heterointerface of layered NbSe2 and CrCl3 flakes. This phenomenon merely occurred when the applied magnetic field is parallel to the sample plane and perpendicular to the electric current direction as compared to the reference sample of a NbSe2 thin flake. The strong anisotropy of the reemergent superconducting phase is pointed to the nature of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state driven by the strong interfacial spin-orbit coupling between NbSe2 and CrCl3 layers. The theoretical picture of FFLO state nodes induced by Josephson vortices collectively pinning is presented for well understanding the experimental observation of the reemergent superconductivity. This finding sheds light on an opportunity to search for the exotic FFLO state in the van der Waals heterostructures with strong interfacial spin-orbit coupling., 24

The slope of the northern South China Sea (SCS) is one of the world’s most active areas of modern marine sedimentary processes. A rapidly deposited sediment drift (RDSD) was identified on the slope near Dongsha Island. The sources of this body have been studied and discussed by several authors, but no consensus has been achieved. Based on multi-channel seismic profiles interpretation and data analysis of long-term observation of bottom currents, we identified that although the amounts of sediments input from the Pearl and Hanjing Rivers, and from Kao-ping and Tseng-Wen Rivers are large, considering the current situation of northern SCS, none of the Pearl River, the Hanjiang River, the Kao-ping River and the Tseng-Wen River can maintain the deposition pattern of the northern SCS margin as the single source, especially to maintain the supper high sedimentation rate at the RDSD area. The Miocene drape formation (MDF) calmly draped over an unconformity after rifting stage resulting in a relatively constant thickness of about 2000 m throughout the overall northern SCS continental margin, and followed by a standard configuration of a clinoform, the Pliocene formation and another clinoform of about another 700 m in total thickness. Due to Dongsha uplift since 3 Ma, roughly 1/2 of MDF and the N2 formation in the Dongsha area measures 150 km by 200 km were denudated resulting in an average annual denudation rate of 60 × 106 t/y. If these sediments were deposited on a slope region within an area measuring 100 km by 100 km, the sedimentation rate could reach 250 cm/ky. This is clearly an impressive new sediment source that has never been discussed before. Moreover, the RDSD is near the Dongsha Uplift and on the adjacent slope. We believe that this new sediment source should be the main contributor for the RDSD development.

Persimmon tannin (PT), a primary physiological component of young persimmon, exhibits antibacterial activity against several microorganisms, but its effect on methicillin-resistant Staphylococcus aureus (MRSA) remains unclear. In this study, we found that PT from young astringent persimmon fruit had an active inhibition against several MRSA isolated from retail pork and the minimum inhibitory concentrations were 1000 μg/mL. Treatment of PT suppressed cell proliferation, caused decreases in membrane potential and intracellular ATP concentration, destroyed whole cell protein integrity, and induced S phase cell cycle arrest. Electron microscopy demonstrated that PT can change the normal morphology of MRSA and cause severe damage on cell wall and cell membrane. These results indicated that PT presented antimicrobial activity against foodborne MRSA and could be potentially developed as an alternative or supplemental agent to control the spread and infection of MRSA in foods.

The electronic and topological properties of MoS2 monolayers with n-p codoping effect are investigated by using first-principles calculations. Two types of the doped Nb atoms play the roles of the p-type and n-type dopants, respectively. The n-p codoping is found inducing a large valley polarization, associated with the strong magnetization induced by the Nb dopants. Interestingly, the system simultaneously owns a perfect Chern insulating band gap opened exactly at the Fermi level. The nontrivial band gap comes from the lifting of the degeneracy of the dxz and dyz orbitals of Nb2 atoms after the spin-orbit coupling is considered. Our work inspires exciting prospects to tune the novel properties of materials with n-p codoping effects.

Using density functional calculations, we elucidate the interaction between magnons and phonons on Fe(001) and O/Fe(001) surfaces. The effective Heisenberg exchange parameters between neighbor sites ( J i ) were derived by fitting the ab initio spin spiral dispersion relation to a classical Heisenberg model. In bulk Fe, J 5 b has a larger amplitude than J 2 b - J 4 b . Surface magnons were softer on the Fe(001) surface than in bulk, but were strengthened on the O/Fe(001) surface through strong interactions between the O and Fe atoms. The four calculated high-energy phonon modes of O/Fe(001) excellently agreed with the experimental measurements. The J 1 in O/Fe(001) decreased significantly with increasing phonon amplitude. Phonon-magnon coupling occurred more easily on O/Fe(001) than on Fe(001). The softening of the magnon on the O/Fe(001) with phonon amplitude was attributed to the reduced amplitude of longitudinal excitations. Magnetic moment of the Fe atom of the second layer (Fe2) was especially sensitive to phonon amplitude, regardless of the motion direction of the Fe2 atoms.

The β-glucosidase derived from microorganisms has attracted worldwide interest for their industrial applications, but studies on β-glucosidases from Oenococcus oeni are rare. In this paper, catalytic mechanism of a novel β-glucosidase BGL0224 of Oenococcus oeni SD-2a was explored for the first time by kinetic parameters determination, fluorescence spectroscopy and quenching mechanism analysis, molecular dynamics simulation. The results indicated that BGL0224 had universal catalytic effect on different types of glycoside substrates, but the catalytic efficiencies were different. Fluorescence quenching analysis results suggested that the quenching processes between BGL0224 and seven kinds of substrates were predominated by the static quenching mechanism. A reasonable three-dimensional model of BGL0224 was obtained using the crystal structure of E.coli BglA as a template. The analysis results of molecular simulation (RMSD, Rg, RMSF and hydrogen bonding) showed that the composite system ‘BGL0224-pNPG’ was very stable after 40 ns. The catalytic process of BGL0224 acting on ‘p-Nitrophenyl β- d -glucopyranoside’ conformed to the double displacement mechanism. Two glutamic acid residues ‘Glu178 and Glu377’ played a vital role in the whole catalytic process. Overall, this study gave specific insights on the catalytic mechanism of BGL0224, which was of great significance for developing its potential applications in food industry.

Phloridzin has been an attractive target for the development of preparation methodologies due to its various applications as pharmaceutical ingredient and food additive. In this study, an enzymatic synthesis approach using engineered P. pastoris GS115 was developed to produce phloridzin. Four factors, identifying as key factors affecting the phloridzin yield, were optimized by response surface methodology as follows: induction time 121.8 h, pH 7.0, methanol 0.75%, and a rotation speed 194 rpm. The maximal yield of phloridzin reached 41.59 mg/L (95.31 μM) and the specific bioconversion rate of substrate was up to 98.50% with 1L working volume in a 5L bioreactor under the optimal conditions. Phloridzin with purity of 93.98% and recovery of 78.14% was achieved just using affinity chromatography and preparative high performance liquid chromatography ( Pre -HPLC). These results confirm the enzymatic synthesis developed provides an efficient alternative to traditional approach for the preparation of phloridzin in vitro .

Fresh “Xuxiang” kiwifruit juice with or without pomace was used for fermentation with different levels of glutathione‐enriched inactive dry yeast (g‐IDY). After alcohol fermentation, the glutathione (GSH) content, color parameters, phenolic composition, and antioxidant activities of kiwi wine were determined. The results suggested that the addition of g‐IDY to kiwi juice increased GSH, glutathione disulfide, total GSH concentrations, and the total phenolic content of kiwi wine. No obvious effect on individual phenolic content was found in wine with g‐IDY. The color parameters of wines fermented with pomace were remarkably improved with addition of 100 mg/L and 300 mg/L g‐IDY. The supply of g‐IDY improved the antioxidant activities of kiwi wine fermented with pomace. Principal component analysis suggested that with the same supplies of g‐IDY, wine fermented with pomace was better than wine fermented through pure juice in all measurements. PRACTICAL APPLICATIONS: The improvements in color and antioxidant capacity of kiwi wine have always been the focus of kiwi wine brewing. Constant improvement in methods which contribute to high quality of kiwi wine provides crucial support for wine industry and even agriculture development. The aim of this study is to investigate the impacts of glutathione‐enriched inactive dry yeast (g‐IDY) on quality of kiwi wine. These results could provide feasible advices about g‐IDY application to kiwi wine for improving the sensory and nutritional properties.

The study of universal critical behavior is a crucial issue in a continuous phase transition, which groups various critical phenomena into universality classes for revealing microscopic electronic behaviors. The understanding of the nature of magnetism in Eu-based ferromagnetic superconductors is largely impeded by the infeasibility of performing inelastic neutron scattering measurements to deduce the microscopic magnetic behaviors and the effects on the superconductivity, due to the significant neutron absorption effect of natural $^{152}\mathrm{Eu}$ and unavailability of large single crystals. However, by systematically combining the neutron diffraction experiment, the first-principles calculations, and the quantum Monte Carlo simulations, we have obtained a perfectly consistent universal critical exponent value of $\ensuremath{\beta}=0.385(13)$ experimentally and theoretically for $\mathrm{Eu}{({\mathrm{Fe}}_{0.75}{\mathrm{Ru}}_{0.25})}_{2}{\mathrm{As}}_{2}$, from which the magnetism in the Eu-based ferromagnetic superconductors is identified as the universal class of a three-dimensional anisotropic quantum Heisenberg model with long-range magnetic exchange coupling. This systematic study points out a suitable microscopic theoretical model for describing the nature of magnetism in the intriguing Eu-based ferromagnetic superconductors.

Reductions in fire frequency (RFF) are known to occur in the area adjacent to the rigid-boundary of simulated forest landscapes. Few studies, however, have removed those edge effected regions (EERs), and many others may, thus, have misinterpreted their simulated forest conditions within those unidentified edges. We developed three methods to detect and remove EERs with RFF and applied them to fire frequency maps of 2900 &times, 2900 grids developed using between 1000 and 1200 fire-year maps. The three methods employed different approaches: scanning, agglomeration, and division, along with the consensus of two and three of those methods. The detected EERs with RFF ranged in mean width from 5.9 to 17.3 km, and occupied 4.9 to 21.3% of the simulated landscapes. Those values are lower than the 40 km buffer width, which occupied 47.5% of the simulated landscape, used in a previous study in this area that based buffer width on length of the largest fire. The maximum width of the EER covaried with wind predominance, indicating it is not possible to prescribe a standard buffer width for all simulation studies. The three edge detection methods differ in their optimality, with the best results provided by a consensus of the three methods. We suggest that future landscape forest simulation studies should, to ensure their results near the rigid boundary are not misrepresentative, simulate an appropriately enlarged study area and then employ edge detection methods to remove the EERs with RFF.

Persimmon tannin (PT) exhibits antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) isolated from retail pork. The involved molecular mechanisms were investigated for the first time using transcriptome and metabolome in this study. Results showed that subinhibitory concentration of PT (0.5 mg/ml) induced significant changes in MRSA at both transcriptional and metabolic levels, as 370 genes and 19 metabolites were differentially expressed. Bioinformatic analysis revealed that the varying genes and metabolites were mainly involved in pathways of membrane transport, amino acids, carbohydrate, and energy metabolism. The highlighted changes were those related to osmotic regulation, intracellular pH regulation, amino acid synthesis and metabolism, glycolysis, TCA cycle and iron metabolism, suggesting the multifaceted effects including cell membrane damage, amino acids limitation, energy metabolism disorder and iron deprivation induced by PT. The results provided insight into the anti-MRSA mechanism of PT, which is useful for PT’s development and application in food safety.

β-glucosidase is widely used in food industry for its glycosidic hydrolysis properties. In this paper, performance of a novel β-glucosidase BGL0224 from Oenococcus oeni for aroma enhancement of Cabernet Sauvignon wines was explored for the first time. The main projects included electronic nose, gas chromatography-mass spectrometry and sensory analysis. Principal component analysis indicated that electronic nose had the ability to discriminate different treatments by responding specifically to volatile compounds. Adding BGL0224 before alcoholic fermentation significantly increased the “aromatic index” of Cabernet Sauvignon wines. Compared with the control group, adding BGL0224 increased more than 15 volatile aroma compounds of Cabernet Sauvignon wines. Furthermore, with the addition of BGL0224 before alcoholic fermentation, the concentrations of medium-chain fatty acid ethyl esters, long-chain fatty acid ethyl esters and terpenes in wines were 3004.19 ± 36.14 μg/L, 4090.37 ± 94.07 μg/L and 210.21 ± 8.98 μg/L respectively, which were all significantly higher than other treatments. Sensory analysis showed that BGL0224 increased “tropical fruity”, “sweet fruity” and “floral notes” characteristics while inhibited “citrus” characteristics of Cabernet Sauvignon wines. Overall, this study provided support for industrial application of BGL0224 by evaluating its performance for aroma enhancement of Cabernet Sauvignon wines.

The lateral flux of dissolved organic carbon (DOC) from soils to inland waters and ultimately to the ocean represents a fundamental component of the global carbon cycle. To estimate the DOC flux, we developed an empirical terrestrial-aquatic DOC fluxes model (TAF-DOC). TAF-DOC incorporates various environmental factors (e.g., meteorology, sulfur, and nitrogen deposition) that to-date have not been comprehensively considered or well-represented in existing modeling frameworks. TAF-DOC was applied to estimate spatial-temporal patterns of DOC flux and potential fates across the conterminous United States during the 1985 to 2018 time period. Our results suggest that TAF-DOC successfully characterized spatial-temporal of DOC flux. As expected, the interannual pattern of DOC flux was strongly regulated by precipitation, but the long-term trend was significantly influenced by the rate of atmospheric wet sulfur deposition. From 1985 to 2018, TAF-DOC estimated DOC loading from terrestrial to aquatic ecosystems in the conterminous United States to be 33.5 ± 2.2 TgC per year, which was roughly 0.39–0.49% of total soil organic carbon stock estimates. The dominant fate of terrestrially-derived DOC was delivery to the coastal ocean in riverine export (41%), with another 21% buried in sediment and the remaining 12.8 ± 0.4 TgC per year (38%) returned to the atmosphere through outgassing from inland waters. Assuming the quantities of DOC sediment burial and export to the ocean as an annual sink of terrestrially-derived carbon, budget inventories and models that do not account for DOC flux in the conterminous United States will underestimate the net annual carbon sink by as much as 5.5–6.4%.

The effects of selenium (Se) addition methods on antioxidant activity and flavor properties of fermented Pleurotus eryngii (P. eryngii) using Lactobacillus plantarum (L. plantarum) inoculated and natural fermentation were investigated. After fermentation, the Se-enrichment rates in fruiting bodies of Se-added fermented P. eryngii were all more than 50%. Se addition, especially in the form of Se-enriched L. plantarum inoculation, had a significantly positive effect on total phenolic content and DPPH radical scavenging activity. Non-volatiles analysis revealed that the highest ration of lactic acid to acetic acid and the highest umami intensity were observed in P. eryngii fermented by inoculating Se-enriched L. plantarum (Lp-Se). Principal components analysis and cluster analysis of volatiles clearly separated Se-treated and plain experiments, which mainly due to dissimilarities in alcohols, aldehydes and ketones. Additionally, Lp-Se obtained the highest alcohols, especially 1-octen-3-ol with mushroom flavor. In short, Se-enriched L. plantarum inoculation could produce high-quality fermented P. eryngii.

Bimetallic Au@Cu core–shell nanocrystals have been synthesized by a two-step seed-mediated growth method through controlled heteroepitaxial growth of Cu shells on Au nanorods serving as seeds. The final crystal structures have cubic morphology with edge lengths from 50 to 100 nm due to a strong affinity of hexadecylamine, which is a selective capping agent for the {100} facets of Cu. Various characterizations reveal that the epitaxial growth mechanism is based on block-type growth mode, rather than layer-by-layer growth mode, owing to the larger mismatch in the different lattice constants between Au core and Cu shell. Moreover, contrastive experiments using Au nanobipyramids as seeds were carried out to gain further insight into the heteroepitaxial growth mechanism. Combining first-principles density-functional theory with experimental results, the binding energies of Cu atoms at different sites on Au surfaces are explored to clarify the aspects of nanostructure formation. This study provides useful insights into the effective synthesis method and the further investigation of the proposed growth mechanism.

The van der Waals interactions are responsible for a large diversity of structures and functions in chemistry, biology, and materials. Discussion of van der Waals interactions has focused on the attractive potential energy that varies as the inverse power of the distance between the two interacting partners. The origin of the attractive force is widely discussed as being due to the correlated fluctuations of electron charges that lead to instantaneous dipole-induced dipole attractions. Here, we use the inelastic tunneling probe to image the potential energy surface associated with the van der Waals interactions of xenon atoms.

β-Glucosidases play an important role in food industry. Oenococcus oeni are typical lactic acid bacteria that initiate malolactic fermentation of wines. 35 β-glucosidases from O. oeni were selected and their conserved domains and evolutionary relationships were further explored in this study. The homology analysis results indicated that 35 β-glucosidases were basically derived from GH1 and GH3 family. A novel β-glucosidase was successfully expressed and characterized. The recombinant protein, referred to as BGL0224, consisted of a total 480 amino acids with an apparent molecular weight of 55.15 kDa and was classified as GH1 family. It achieved the highest activity at pH 5.0 and 50 °C. The activity and stability were significantly increased when 12% ethanol was supplemented to the enzyme. Using p-NPG as substrate, the Km, Vmax and Kcat of BGL0224 were 0.34 mM, 382.81 U/mg and 351.88 s−1, respectively. In all, BGL0224 has good application prospects in food industry.

To reveal the origin of the deep in-gap states in hydrogenated TiO 2 (H:TiO 2 ), which are located ∼ 1.5 eV below the conduction band minimum (CBM) and largely enhance the absorption of visible light, we systematically investigate the structural stabilities, electronic states and optical absorption of various defects in hydrogenated rutile and anatase TiO 2 using first-principles calculations with the HSE06 hybrid functional. Our results show that some double-oxygen-vacancy cluster configurations can induce occupied deep in-gap states, while the other defects, including substitutional H impurities and single oxygen vacancies, only induce shallow in-gap states. The deep in-gap states can strongly absorb visible light and effectively produce holes in the valence band (VB). The components of the in-gap states and electron transition channels between the in-gap states and the conduction band (CB) or the VB are also presented. Noticeably, the structural stability study shows that substitutional H is more energetically stable than oxygen vacancies.

The purpose of this paper is to design one-dimensional chaotic maps with a non-zero intercept in the Y-axis and research the basic dynamic characteristics. First, by studying the common conditions that make one-dimensional discrete dynamical systems chaotic under the modulo operation, the general theory of the chaotic behavior of one-dimensional nonlinear functions with a non-zero origin is presented. It is proved that the discrete dynamic system derived from the proposed theory exhibits chaos phenomena in the sense of Li-Yorke, utilizing the improved version of Marotto’s theorem. Furthermore, the part of the discrete dynamical functions satisfying the proposed chaos theory is given. The function track, bifurcation diagram and Lyapunov exponential spectrum are also analyzed. Numerical simulations agree with the analytical framework for the suggested chaos theory. Finally, given the application of chaos in cryptographic communication, two significant corollaries of the original functions as general polynomials are put forward according to the theory of chaos structure.

Graphene fiber-based supercapacitors have attracted tremendous interest and possess the greatest potential for flexible/wearable energy storage devices. However, their specific capacitance and energy density are not sufficient and impede their widespread practical application. Here, polyaniline/graphene hybrid fibers (PANI/GF) were fabricated by a simple in situ chemical polymerization of polyaniline on graphene fibers synthesized by the wet-spinning method and a chemical reduction process. The crumpled morphology of the graphene fibers and polymerization process in a dilute solution of aniline monomer improve the structural uniformity and stability of the composite fibers. The hybrid fibers based flexible supercapacitor with solid-state electrolyte not only deliver high specific capacitance of 87.8 m F cm−2 and high energy density of 12.2 μW h cm−2 at a current density of 0.22 mA cm−2, but also exhibits long cycling stability after 10,000 cycles. This is mainly ascribed to the uniform dispersion of polyaniline on the graphene fibers and the stable structure of the hybrid fibers. The as-synthesized graphene hybrid fibers are a promising candidate for flexible/wearable supercapacitors.

Ethanol acclimations have been proven to be beneficial for enhancing the viability of lyophilized Oenococcus oeni. To explore the relevant mechanisms, cell integrity, protein patterns, morphology, exopolysaccharides (EPS) content of lyophilized O. oeni SD-2a with ethanol acclimations were investigated in this research. After freeze-drying, the improvement of cell integrity was found in all ethanol acclimated cells. Comparative proteomics combined with bioinformatics revealed the important role of central carbohydrate metabolism, polysaccharides production, cell envelope biosynthesis and stress responses related proteins with ethanol acclimations in freeze-dried O. oeni SD-2a. Extracellular polymeric substances were observed in mild ethanol (5% and 8%) adapted cells using scanning electron microscope. In addition, mild ethanol (5% and 8%) adapted cells showed higher EPS content. Transcriptional analysis showed that citrate lysis gene over-expressed in all ethanol acclimated freeze-dried cells. Therefore, citrate was added in culture medium and it is highlighted that the addition of citrate was useful for the growth of freeze-dried O. oeni SD-2a. These results provide new insights of molecular mechanisms regulated by ethanol acclimation and improve our understanding of biological characteristics involved in freeze-dried O. oeni.

Malolactic fermentation (MLF), usually induced by Oenococcus oeni (O. oeni), is an important process to improve wine quality. Acid acclimation has been proven to be useful for enhancing the viability of lyophilized O. oeni. To explain the involved mechanisms, cell integrity, morphology and protein patterns of lyophilized O. oeni SD-2a were investigated with acid acclimation. After lyophilization, improvement of cell integrity and more extracellular polymeric substances (EPS) were observed in acid acclimated cells. Combined with GO and KEGG analysis, different abundant proteins were noticeably enriched in the carbohydrate metabolism process, especially amino sugar and nucleotide sugar metabolism. The most significant result was the over-expression of proteins participating in cell wall biosynthesis, EPS production, ATP binding and the bacterial secretion system. This result indicated the important role of acid acclimation on cell envelope properties. In addition, protein response to stress and arginine deiminase pathway were also proven to be over-expressed.

The accumulation of selenium (Se) by Lactobacillus delbrueckii ssp. bulgaricus (Lb) and Streptococcus thermophilus (St) at the different cultivation conditions, including initial pH, inoculum dose (%), and temperature (°C), was investigated in this work. Se enrichment efficiency was optimized using the Design-Expert software for response surface methodology on a basis of single-factor experiment. The antioxidant activities of Se-enriched Lactic acid bacteria (LAB) were also investigated. The qualitative analysis of Se-enriched LAB was performed by FT-IR spectra. The cell morphology and chemical element components were measured by a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy. The results indicated that the optimum initial pH, inoculum doses, and temperatures of Lb and St were 5.96, 6.73%, 33.24 °C, and 6.37, 6%, 40 °C, respectively. Under the optimal conditions, the ratios of Se enrichment reached 94.34% for Lb and 97.05% for St. Furthermore, Se-enriched LAB enhanced scavenging rates on DPPH, ABTS free radical, and also heightened reducing activity. The FT-IR results showed that the two Se-enriched strains had similar characteristic absorption peaks, which were further demonstrated that both Se biomasses had the same carbonyl, carboxyl, and hydroxyl groups. Elemental selenium nanoparticles were verified around cell surfaces of Se-enriched LAB, which implied that both strains had detoxification ability when grown in liquid media containing selenite.

Electronic and topological properties of $\mathrm{Mo}{\mathrm{S}}_{2}$ monolayers endowed with $3d$ transition metal (TM) adatoms (V-Fe) are explored by using ab initio methods and $k\ifmmode\cdot\else\textperiodcentered\fi{}p$ models. Without the consideration of the Hubbard $U$ interaction, the V, Cr, and Fe adatoms tend to locate on the top of the Mo atoms, while the most stable site for the Mn atom is at the hollow position of the Mo-S hexagon. After the Hubbard $U$ is applied, the most stable sites of all the systems become the top of the Mo atoms. Chern insulators without band inversion are achieved in these systems. The V and Fe adsorption systems are the best candidates to produce the topological states. The $k\ifmmode\cdot\else\textperiodcentered\fi{}p$ model calculations indicate that these topological states are determined by the TM magnetism, the ${C}_{3v}$ crystal field from the $\mathrm{Mo}{\mathrm{S}}_{2}$ substrate, and the TM atomic spin-orbit coupling (SOC). The special two-meron pseudospin texture is found to contribute to the topology. The apparent difference between the Berry curvatures for the V and Fe adsorption systems is also explored. Our results widen the understanding of the Chern insulators and are helpful for the applications of the $\mathrm{Mo}{\mathrm{S}}_{2}$ monolayers in the future electronics and spintronics.

Disturbances are a primary force regulating the successional development and associated carbon cycling in forest ecosystems, but our understanding of these dynamics is based on studies mostly limited to relatively homogeneous and high intensity forest disturbances such as harvesting and wildfire. Contrarily, extensive insect defoliations such as that caused by spruce budworm (SBW; Choristoneura fumiferana (Clem.)) often are species-specific and vary greatly in their intensities and consequent influences on forest carbon dynamics over large spatial and temporal extents. In this study, we applied an individual tree growth model across a large forested area in the state of Maine, USA to simulate the impact of SBW outbreaks on above-ground carbon stock in merchantable trees, which is the primary carbon pool of interest in forest management and its associated downstream industries. The model, the Acadian Variant of the Forest Vegetation Simulator (FVS-ACD), provides the necessary resolution needed to capture the spatio-temporal variability in SBW defoliation and its impacts on the mixed species, structurally complex spruce-fir (Picea-Abies) forests of Maine. Our evaluation of two 40-year SBW outbreak cycles (1975–2015 and 2017–2057) indicates that, due primarily to changing species composition (particularly significant increases of hardwood species), this carbon stock of spruce-fir forests was not reduced and not significantly different than what it would be without an outbreak at the end of either cycle. However, there were temporary decreases in carbon growth immediately following these outbreaks. These decreases were at smaller scales in the 40-year cycle starting 2017 where significant increases of hardwood species along with decreases of SBW's primary host species were observed. As this trend of changing species composition continues in this region, a future SBW outbreak would cause less reduction in carbon growth and less likely to result in a decrease of carbon stock in spruce-fir forests. Overall, the utilized tree-level modeling framework may prove useful for assessing the influence of complex disturbances like insect defoliation in other regions.

The influent and effluent nitrogen compositions of an expanded granular sludge blanket (EGSB) reactor employed for treating food waste (FW) operated under ambient temperature was evaluated. Additionally, dynamic changes in the bacterial community structures and its metabolic functions were investigated. Results show that the EGSB reactor had a good effect on FW disposal and well resistance to variations in the organic loading rate. Furthermore, the COD concentration in the influent increased to about 10,000 mg/L and the COD removal rate stabilized at about 95%. The dissolved ammonia nitrogen ( d -ammonia) content was the largest, accounting for approximately 70–80% of the dissolved nitrogen in the effluent. The amount of particulate organic nitrogen (PON) decreased by about 25%–33%. Amino acid, carbohydrate and lipid metabolism decreased at high organic loading rate (OLR). Meanwhile, the abundance of Methanothrix increased from 30.82% to 70.25%, whereas Methanobacterium decreased from 66.14% to 14.49%.

To investigate the effect of reduced glutathione (GSH) on the quality characteristics of apple wine, 10, 20 and 30 mg/L of GSH were added to apple juice before alcoholic fermentation. Meanwhile, apple wine fermented by Saccharomyces cerevisiae which had been pre-incubated with GSH (100 mg/L) was another experimental group. Mono-phenols, GSH and oxidized glutathione (GSSG) were determined by HPLC. Aroma compounds were analysed by GC–MS. Further, E-nose was applied to monitor the odor. After fermentation, GSH content was the same in all of the samples. However, for the apple wine with GSH addition, GSSG content increased significantly. Notably, GSH could reduce the color index, protect chlorogenic acid and phloretin, decrease the content of epicatechin and catechin as well as change the profile of aroma compounds (higher levels of 2-methyl-1-propanol, 3-methyl-1-butanol, ethyl benzoate, linalool, etc.). GSH may be used for flavor enhancement and quality improvement of apple wine.

Phloretin-2′-O-glycosyltransferase (P2′GT) catalyzes the last glycosylation step in the biosynthesis of phloridzin that contributes to the flavor, color and health benefits of apples and processed apple products. In this work, a novel P2′GT of Malus x domestica (MdP2′GT) with a specific activity of 46.82 μkat/Kg protein toward phloretin and uridine diphosphate glucose (UDPG) at an optimal temperature of 30 °C and pH 8.0 was purified from the engineered Pichia pastoris broth to homogeneity by anion exchange chromatography, His-Trap affinity chromatography and gel filtration. The purified MdP2′GT was low N-glycosylated and secreted as a stable dimer with a molecular mass of 70.7 kDa in its native form. Importantly, MdP2′GT also exhibited activity towards quercetin and adenosine diphosphate glucose (ADPG), kaempferol and UDPG, quercetin and UDP-galactose, isoliquiritigenin and UDPG, and luteolin and UDPG, producing only one isoquercitrin, astragalin, hyperoside, isoliquiritin, or cynaroside, respectively. This broad spectrum of activities make MdP2′GT a promising biocatalyst for the industrial preparation of the corresponding polyphenol glycosides, preferably for their subsequent isolation and purification. Besides, MdP2′GT displayed the lowest Km and the highest kcat/Km for phloretin and UDPG compared to all previously reported P2′GTs, making MdP2′GT favor phloridzin synthesis the most.

Visualizing halogen bonding Even though halogen atoms are highly electronegative, a noncovalent bond can form between an electron donor and a halogen atom in a covalent bond. Such interactions are facilitated by the formation of electron-depleted regions in the halogen's covalent bond, a situation least likely for fluorine atoms. Han et al. used noncontact scanning tunneling microscopy with submolecular resolution to explore how the size and polarizability of halogens affect complex formation by halogenated benzene molecules adsorbed on a silver surface (see the Perspective by Neaton). With the help of density functional theory, they show how several weak interactions, including van der Waals forces, electrostatic repulsions, and halogen bonds, affect structure. Science , this issue p. 206 ; see also p. 167