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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.

East Java, on the southeastern margin of the Sundaland Shelf, is an ideal and pilot location to study paleogeographic changes due to the interactions of the Eurasian and the Indian-Australia plates. Many studies have been conducted; however, some issues remain poorly understood, such as the initial compression stage and associated paleogeography of East Java. Here, we report newly acquired high-resolution seismic data and drilling wells in the area of the Madura Strait. We systematically reconstruct a three-dimensional model on the paleogeography of East Java in the Middle Miocene in combination with others’ results. Different depositional environments and characteristics of the related lithofacies observed on both sides of the Middle Miocene volcanic arc imply that weak subaerial and subaqueous volcanism existed in East Java. The extensive Ngrayong fining in the southward clastic sequences, located north of the mentioned volcanic arc, were deposited in a bathyal marine environment, which showed an oversteepening slope and basinal characteristics with outer neritic to bathyal facies within the present-day Kendeng Zone and Madura Strait area. This differs from the northern region of the present-day Rembang-Madura Inversion Zone and the northern offshore region of East Java, which were deposited in a transitional and neritic marine environment. We identified two new turbidite fans showing opposite source directions based on 3D seismic data within the Madura Strait area. Four controlling factors contributed to the formation of the Ngrayong turbidite fans, including the paleotopography of the underlying Kujung Formation, short-term intense regional tectonic events, high rates of sediment supply and occasional volcanic activity.

This study provided phenotypic and molecular analysis of the antibiotic resistance within coagulase-negative staphylococci and lactic acid bacteria isolated from naturally fermented Chinese cured beef. A total of 49 strains were isolated by selective medium and identified at the species level by 16S rRNA gene sequencing as follows: Staphylococcus carnosus (37), Lactobacillus plantarum (6), Weissella confusa (4), Lactobacillus sakei (1), and Weissella cibaria (1). All strains were typed by random amplified polymorphic DNA fingerprinting, and their antibiotic resistances profiles to 15 antibiotics were determined as the MIC by using the agar dilution method. All the tested strains were sensitive to ampicillin, and most of them were also sensitive to penicillin, gentamycin, neomycin, norfloxacin, and ciprofloxacin with low MICs. High resistance to streptomycin, vancomycin, erythromycin, roxithromycin, lincomycin, and kanamycin was widely observed, while the resistant levels to tetracycline, oxytetracycline, and chloramphenicol varied. The presence of corresponding resistance genes in resistant isolates was investigated by PCR, with the following genes detected: tet(M) gene in 9 S. carnosus strains and 1 W. confusa strain; erm(F) gene in 10 S. carnosus strains; ere(A) gene in 6 S. carnosus strains; ere(A) gene in 4 S. carnosus strains and 1 L. plantarum strain; and str(A) gene and str(B) gene in 3 S. carnosus strains. The results indicated that multiple antibiotic resistances were common in coagulase-negative staphylococci and lactic acid bacteria strains isolated from naturally fermented Chinese cured beef. Safety analysis and risk assessment should be performed for application in meat products.

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.

Oenococcus oeni (O. oeni) induces malolactic fermentation to improve wine quality. However, the molecular basis of mechanisms involved in its freeze-drying resistance remains unclear. In this work, O. oeni SD-2a without freeze-drying (No-FD), with freeze-drying (FD) and freeze-drying with monosodium glutamate (MSG) (FD-MSG) were investigated. Flow cytometry results showed severe cell damage in FD cells and less membrane transmissibility in FD-MSG cells. Meanwhile, extracellular polymeric substances (EPS) were detected in FD and FD-MSG cells by scanning electron microscopy. Bioinformatic analysis revealed that varying proteins were involved in carbon, lipid and nucleic acids metabolism, stress response, oxidoreductase activity and signal sensing. Among the identified proteins, the highlighted proteins were those involved in polysaccharides production and signal sensing for freeze-drying resistance and cyclopropane fatty acid metabolism for MSG addition.

The aim of this study was to evaluate the antibiotic susceptibility of lactic acid bacteria (LAB) and coagulase-negative staphylococci (CNS) strains isolated from naturally fermented smoked pork produced in Hunan, China. A total of 48 strains were isolated by selective medium and identified at the species level by 16S rRNA gene sequencing as follows: Staphylococcus carnosus (23), Lactobacillus plantarum (12), Lactobacillus brevis (10), Lactobacillus sakei (1), Weissella confusa (1), and Weissella cibaria (1). All strains were typed by RAPD-PCR, and their susceptibility to 15 antibiotics was determined and expressed as the minimum inhibitory concentration (MIC) using agar dilution method. High resistance to penicillin G, streptomycin, gentamycin, vancomycin, chloramphenicol, norfloxacin, ciprofloxacin, kanamycin, and neomycin was found among the isolates. All the strains were sensitive to ampicillin, while the susceptibility to tetracycline, oxytetracycline, erythromycin, lincomycin, and roxithromycin varied. The presence of relevant resistance genes was investigated by PCR and sequencing, with the following genes detected: str(A), str(B), tet(O), tet(M), ere(A), and catA. Eleven strains, including 3 S. carnosus, 6 L. plantarum, and 2 L. brevis, harbored more than 3 antibiotic resistance genes. Overall, multiple antibiotic resistance patterns were widely observed in LAB and S. carnosus strains isolated from Hunan smoked pork. Risk assessment should be carried out with regard to the safe use of LAB and CNS in food production.We evaluated the antibiotic resistance of lactic acid bacteria and coagulase-negative staphylococci strains isolated from Chinese naturally fermented smoked pork. Our results may provide important data on establishing breakpoint standards for LAB and CNS and evaluating the safety risk of these strains for commercial use.

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.

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.

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.

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

We propose a consolidated risk measure based on variance and the safety-first principle in a mean-risk portfolio optimization framework. The safety-first principle to financial portfolio selection strategy is modified and improved. Our proposed models are subjected to norm regularization to seek near-optimal stable and sparse portfolios. We compare the cumulative wealth of our preferred proposed model to a benchmark, S&P 500 index for the same period. Our proposed portfolio strategies have better out-of-sample performance than the selected alternative portfolio rules in literature and control the downside risk of the portfolio returns.

UNLABELLED This article describes the cloning, sequence analysis and expression of the DnaJ gene from Alicyclobacillus acidoterrestris. The genome walking technique was used to clone the full-length sequence of DnaJ and quantitative real-time PCR was used to analyze DnaJ expression under stress conditions. AadnaJ (GenBank accession nr: HQ893544) containing an open reading frame of 1137 bp encoding 378 amino acid residues was cloned from A. acidoterrestris DSM 3922(T). The nucleotide sequence of AadnaJ shows 77% homology with the DnaJ of A. acidocaldarius LAA1. The DnaJ expression level was upgraded rapidly under heat or acid stress. Its mRNA expression level reached a peak value at 25 min after the onset of heat stress (70 °C) and at 1 h after the onset of acid stress (pH = 1). Acid stress at pH 1 for 25 and 60 min led to the DnaJ expression levels 2.1 times and 35.7 times above that of the control, respectively. In response to cold stress at 0 °C, the DnaJ expression level decreased drastically to 0.04 times that of the control level after 1 h. The expression patterns of DnaJ in response to the stress conditions shown here explained the heat and acidity endurance of A. acidoterrestris. PRACTICAL APPLICATION This study directly addresses the role of the DnaJ gene in temperature and acid endurance in A. acidoterrestris. This provides a basis for the development of genetic and molecular techniques that may minimize the adverse effects of A. acidoterrestris in fruit juice production. This study also sheds light on the design of heat- and acid-tolerant recombinases and the understanding of the molecular mechanisms underlying heat and acid resistance in A. acidoterrestris.

The local atomic and electronic structures around the dopants in Cr-doped $({\mathrm{Bi}}_{x}{\mathrm{Sb}}_{1\ensuremath{-}x}){}_{2}{\mathrm{Te}}_{3}$ are studied by x-ray absorption fine structure (XAFS) measurements and first-principles calculations. Both Cr and Bi are confirmed substituting Sb sites $({\mathrm{Cr}}_{\mathrm{Sb}}$ and ${\mathrm{Bi}}_{\mathrm{Sb}})$. The six nearest Te atoms around Cr move towards Cr and shorten the Cr-Te bond lengths to 2.76 \AA{} and 2.77 \AA{} for $x=0.1$ and $x=0.2$, respectively. Importantly, we reveal the hybridization between the Sb/Te $p$ states and Cr $d$ states by the presence of a pre-edge peak at Cr $K$-absorption edge, which is also supported by our ab initio calculations. These findings provide important clues to understand the mechanism of ferromagnetic order in this system with quantum anomalous Hall effect.

By using first-principles electronic and magnetic as well as ferroelectric property calculations on the ferroelectric compound ${\mathrm{PbBaFe}}_{2}{\mathrm{O}}_{5}$, we find that the ground states of the two ${\mathrm{PbBaFe}}_{2}{\mathrm{O}}_{5}$ phases, the space group $Imma$ and $Pnma$ phases, exhibit an antiferromagnetic structure with a propagation vector $[0,\frac{1}{2},\frac{1}{2}]$ state and the magnetic moment of $3.99 {\ensuremath{\mu}}_{B}$ on Fe atoms, which are in good agreement with neutron diffraction experiments. In addition, we find that this magnetic ordering state is an insulating state with an energy gap of 2.24 (2.62) eV for the $Imma (Pnma)$ phase. These findings can be tested by future optical measurements. Furthermore, the parameters of magnetic exchange coupling are also evaluated to illustrate the nature of frustrated magnetic behaviors based on the localized Heisenberg model. Finally, we discuss whether the presence of an improper geometric spin frustration causes the appearance of ferroelectricity.

Transition-metal-doped Bi2Se3 crystals, X0.05Bi2Se3 (X = Cr, Co, Ni, and Cu), are prepared and studied by powder x-ray diffraction and extended x-ray absorption fine structure (EXAFS) measurements to get the local structures around the dopants. Cr atoms substitute Bi atoms and Co atoms may substitute Bi atoms or form Co3Se4 (C2/m) clusters. Cu is also found taking the Bi substitutional site, which differs from the reported superconductor phase of Cu-doped Bi2Se3, suggesting the dependence of site occupancy of Cu in Bi2Se3 on the process of sample growing. For Ni0.05Bi2Se3, Ni atoms form Ni3Se4 (C2/m) clusters. The nearest neighbors of X (X = Cr, Co, and Cu) are Se atoms, and the X-Se bond lengths are extracted from EXAFS as 2.50 angstrom for Cr-Se, 2.40 angstrom for Co-Se, and 2.38 angstrom for Cu-Se, which show the direct evidences of dramatic structural relaxations around 3d dopants. The bond information of local structures around dopants is valuable for subsequent theoretical studies, and can hardly be obtained from other techniques.

We investigate spin-dependent thermoelectronic transport properties of a single molecule magnet Mn(dmit)2 sandwiched between two Au electrodes using first-principles density functional theory combined with nonequilibrium Green's function method. By applying a temperature difference between the two Au electrodes, spin-up and spin-down currents flowing in opposite directions can be induced due to asymmetric distribution of the spin-up and spin-down transmission spectra around the Fermi level. A pure spin current and 100% spin polarization are achieved by tuning back-gate voltage to the system. The spin caloritronics of the molecule with a perpendicular conformation is also explored, where the spin-down current is blocked strongly. These results suggest that Mn(dmit)2 is a promising material for spin caloritronic applications.

Based on first-principles calculations, we found that the surface adsorption energetics of Ag on a Si(111) surface can be modified by imposing an external electric field. The preferred adsorption site is found to be field dependent. The most energetically favorable adsorption site of Ag on the Si(111) surface, among all the considered sites (hcp, fcc, bridge, and top), will undergo a transformation from the fcc site to the top site with an increase in field strength when the surface is positively biased.

Using an ab initio method, we explored electronic structures and transport properties of zigzag graphene nanoribbons (ZGNRs) with ordered doping of B or N atoms. We find B or N atoms doping can increase significantly the conductance of the ZGNRs with an even number of zigzag chains due to additional conducting channels being induced and the breakdown of parity limitation. The higher the doping concentration, the larger the current amplification factor obtained. For the nanojunctions with one row B (or N) atoms, the current amplification factor can be larger when the doping position is near to the center, while for the junction with two rows, the trend is subtle due to the interactions between the two rows of B (or N) atoms. Negative differential resistive phenomena are found for the case of B doping at low concentrations and the case for N doping. The conductance of the ZGNR with odd numbers of zigzag chains can also be increased by doping of B or N atoms. More interestingly, the B or N doping can almost completely remove the even-odd effect on electronic transport of the ZGNRs. Our studies provide avenues to drastically improve the electronic transport of ZGNRs, helpful for graphene applications.