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Lactococcus lactisis a crucial food-grade cell factory for secreting valuable peptides and proteins primarily via the Sec-dependent pathway. YidC, a membrane insertase, facilitates protein insertion into the lipid membrane for the translocation. However, the mechanistic details of how YidC affects protein secretion in L. lactisremain elusive. This study investigates the effects of deleting yidC1/yidC2on L. lactisphenotypes and protein secretion. Compared to the original strain, deleting yidC2significantly decreased the relative biomass, electroporation efficiency, and F-ATP activity by 25%, 47%, and 33%, respectively, and weakened growth and stress resistance, whereas deleting yidC1had a minimal impact. The absence of either yidC1or yidC2reduced target proteins secretion. Meanwhile, there is a considerable alteration in the transcription levels of genes involved in the secretion pathway, with secYtranscription increasing over 135-fold. Our results provide a theoretical foundation for further improving target protein secretion and investigating the YidC function.

The piezoelectric properties of two-dimensional semiconductor nanobubbles present remarkable potential for application in flexible optoelectronic devices, and the piezoelectric field has emerged as an efficacious pathway for both the separation and migration of photogenerated electron–hole pairs, along with inhibition of recombination. However, the comprehension and control of photogenerated carrier dynamics within nanobubbles still remain inadequate. Hence, this study is dedicated to underscore the importance of in situdetection and detailed characterization of photogenerated electron–hole pairs in nanobubbles to enrich understanding and strategic manipulation in two-dimensional semiconductor materials. Utilizing frequency modulation kelvin probe force microscopy (FM-KPFM) and strain gradient distribution techniques, the existence of a piezoelectric field in monolayer WS2nanobubbles was confirmed. Combining w/o and with illumination FM-KPFM, second-order capacitance gradient technique and in situnanoscale tip-enhanced photoluminescence characterization techniques, the interrelationships among the piezoelectric effect, interlayer carrier transfer, and the funneling effect for photocarrier dynamics process across various nanobubble sizes were revealed. Notably, for a WS2/graphene bubble height of 15.45 nm, a 0 mV surface potential difference was recorded in the bubble region w/o and with illumination, indicating a mutual offset of piezoelectric effect, interlayer carrier transfer, and the funneling effect. This phenomenon is prevalent in transition metal dichalcogenides materials exhibiting inversion symmetry breaking. The implication of our study is profound for advancing the understanding of the dynamics of photogenerated electron–hole pair in nonuniform strain piezoelectric systems, and offers a reliable framework for the separation and modulation of photogenerated electron–hole pair in flexible optoelectronic devices and photocatalytic applications.

Single-crystal semiconductor-based photocatalysts exposing unique crystallographic facets show promising applications in energy and environmental technologies; however, crystal facet engineering through solid-state synthesis for photocatalytic overall water splitting is still challenging. Herein, we develop a novel crystal facet engineering strategy through solid-state recrystallization to synthesize uniform SrTiO3single crystals exposing tailored {111} facets. The presynthesized low-crystalline SrTiO3precursors enable the formation of well-defined single crystals through kinetically improved crystal structure transformation during solid-state recrystallization process. By employing subtle Al3+ions as surface morphology modulators, the crystal surface orientation can be precisely tuned to a controlled percentage of {111} facets. The photocatalytic overall water splitting activity increases with the exposure percentage of {111} facets. Owing to the outstanding crystallinity and favorable anisotropic surface structure, the SrTiO3single crystals with 36.6% of {111} facets lead to a 3-fold enhancement of photocatalytic hydrogen evolution rates up to 1.55 mmol·h–1in a stoichiometric ratio of 2:1 than thermodynamically stable SrTiO3enclosed with isotropic {100} facets.

We have theoretically deduced the condition where the signal-to-Rayleigh scattering noise (RSN) ratio can be optimally improved in the same-wavelength bidirectional (SWB) fiber communication systems, based on which an integral research about the feasibility of the SWB coherent fiber communication scheme and the benefits compared with the unidirectional system have been carried out. The theoretical deduction shows that the lossless transmission has a best effect on reducing the interference of the RSN on the signal, which has been verified by experiments in terms of OSNR. Based on the theory, systematic experiments have been carried out, during which the distributed Raman amplifiers (DRAs) were utilized to construct the quasi-lossless transmission to improve the OSNR. The results show that with the assistance of DRAs, an extra 90% spectral efficiency (SE) can be obtained over a 75 km fiber and an 80% SE gain should be attained over a 100 km fiber by the same-wavelength bidirectional scheme over the unidirectional system.

The lamellar and orientational characteristics of graphene nanoplatelets (GNPs) are crucial for reinforcing metal matrix composites, particularly in terms of their thermal properties. Two kinds of GNPs with plane sizes of 6 µm and 80 µm were respectively used as reinforcements in ZK60 alloy by powder metallurgy. The oriented distribution of GNPs in the matrix was obtained using a double-pass hot extrusion process, i.e., a stepped extrusion with two consecutive extrusion ratios (10:1 and 16:1). Reinforced with 0.05 wt% oriented GNPs (80 µm), the composite exhibited a tensile yield strength of 257 MPa, ultimate tensile strength of 342 MPa, elongation of 24.7%, and notably enhanced thermal conductivity of 128.3 W (mK)−1even with refined grain size compared to the ZK60 alloy. The oriented GNPs in the matrix create a favorable path for efficient load and heat transfer, leading to the simultaneously enhancement of mechanical and thermal properties of the GNPs/ZK60 composites. This work is expected to broaden the application potential of GNPs as highly efficient reinforcements and provide a practical method for fabricating metal matrix composites.

Powerful relativistic jets are one of the ubiquitous features of accreting black holes in all scales1–3. GRS 1915 + 105 is a well-known fast-spinning black-hole X-ray binary4with a relativistic jet, termed a ‘microquasar’, as indicated by its superluminal motion of radio emission5,6. It has exhibited persistent X-ray activity over the last 30 years, with quasiperiodic oscillations of approximately 1–10 Hz (refs. 7–9) and 34 and 67 Hz in the X-ray band10. These oscillations probably originate in the inner accretion disk, but other origins have been considered11. Radio observations found variable light curves with quasiperiodic flares or oscillations with periods of approximately 20–50 min (refs. 12–14). Here we report two instances of approximately 5-Hz transient periodic oscillation features from the source detected in the 1.05- to 1.45-GHz radio band that occurred in January 2021 and June 2022. Circular polarization was also observed during the oscillation phase.

Severe atomic migration occurs in the solder under the effect of multi-physics field coupling, leading to serious reliability problems. Under the influence of multi-physics field coupling, severe atomic migration occurs in solder, resulting in significant reliability issues. In Cu/Sn58Bi/Cu joints subjected to 0.5 × 104A/cm2current density and temperature cycling from −45 °C to 60 °C, the primary diffusing atom was Bi. However, when the temperature range was extended to −45 °C–90 °C, Cu atoms became the primary diffusing species. This led to rapid thickening of the interfacial intermetallic compound (IMC) and failure due to penetration cracks and excessive consumption of the Cu interconnect layer. The addition of Sb to Sn58Bi to form (Cu, Sb)6Sn5IMC inhibited Cu atom migration and mitigated rapid dissolution of the Cu interconnect layer and overgrowth of the interfacial IMC. The formation of a biphasic structure adjacent to the interfacial IMC improved joint deformability and prevented premature joint failure. COMSOL analysis revealed that the highest current densities in the Cu/Sn58Bi/Cu interconnect layer and solder joint were 6.041 × 104 A/cm2and 1.368 × 104A/cm2, respectively, under the influence of 0.5 × 104 A/cm2current. The current density in the Cu interconnect layer was 4–5 times higher than that inside the solder joint. However, the addition of Ni formed (Cu, Ni)6Sn5IMC, promoting Cu atom diffusion and accelerating joint failure under multi-physics field coupling. This study provides key insights into how alloying elements modulate atomic migration in Sn–Bi-based solder joints.

In the era of big data, the advantages of 3D packaging are becoming increasingly significant. In addition, the mismatch between the coefficient of thermal expansion (CTE) of the PCB and BGA components leads to dynamic warpage of the system, and the expansion and innovation of low-temperature soldering have been a new trend. We developed a fully mixed solder joint of a SAC305(Sn-3.0Ag-0.5Cu wt.%) solder ball and Sn–58Bi(wt.%) solder paste by solid-liquid low-temperature solder bonding technology. The mixing degree and diffusion process of the two were calculated and simulated by mathematical calculation and COMSOL Multiphysics. The results show that a completely mixed solder joint can be obtained after reflow at 210 °C for 5 min. The average shear strength of the composite solder joints was 63.68 ± 1.12 MPa, which was about twice that of the single SAC305 and Sn58Bi solder joints, and the shear fracture was a composite mode of brittle and ductile fracture, which appeared in the IMC and the solder, respectively. After complete mixing, the solder wettability angle was less than 26.68°, with outstanding wetting properties. No phase transition occurred after aging, the distribution of each phase remained uniform, and no enrichment of the brittle phase was observed at the interface. The shear strength decreased slightly with aging time, and the reduction value was less than 10 MPa, which has good reliability.

Seismic signals are usually nonlinear and nonstationary. The Fourier transform (FT) based on stationary signal processing theory cannot depict the frequency components at any moment. However, the time–frequency analysis (TFA) methods have the capability of describing the partial features of signal both in time and frequency domains. S transform (ST), as a common TFA method, has great time–frequency (TF) combination characteristics, but the changing trend of the window function is fixed and the TF resolution cannot be adjusted. In addition, for seismic signals, the peaks of the frequency distribution in the TF spectrum bias the actual Fourier spectrum, which will affect the accuracy of data analysis. Therefore, we propose a new TFA method called the deconvolutive improved S transform (DIST). The DIST introduces one parameter to the window function other than multiple parameters to improve the flexibility in the application process. The normalization factor is also removed from the window function to avoid the frequency bias. Moreover, the deconvolution in DIST can further improve the accuracy of TF representation. The comparison of the TFA results of synthetic seismic signals shows that the DIST has better TF resolution and energy aggregation than other TFA methods in this article. By adding different degrees of noise to synthetic seismic signals, we conclude that DIST has better noise robustness. Finally, we apply DIST to different field data for hydrocarbon detection, and the results are basically consistent with the drilling data.

Surface Cu+modified ZnIn2S4photocatalysts with spatial separation of energy levels remarkably suppress the recombination of electron and hole and thus enhance the photocatalytic H2evolution.

Metal-organic frameworks (MOFs) possess the features of highly porosity-tunable and electronic-tunable structures. Taking advantages of these merits, we successfully installed high-valence W6+ions onto the Ti-oxo clusters of MIL-125(Ti) (W-MIL-125). The installed W6+ions which form a W-O-Ti structure trigger the metal-to-cluster charge transfer (MCCT), together with an enhanced light absorption. Structural and spectroscopic characterizations reveal that the MCCT process optimizes the charge transfer process and efficiently separates the photogenerated electron-hole spatially. The as-obtained sample of 3.45 W-MIL-125 with optimized electronic structure demonstrates an enhanced photocatalytic hydrogen evolution performance of 1110.7 ± 63.7 µmol g−1h−1under light irradiation, which is 4.0 times that of the pristine MIL-125(Ti). This work will open up a new avenue for local structural modification of MOFs to boost photocatalytic performance.

Potassium-doped picene films grown on an Au(111) surface have been investigated using low-temperature scanning tunneling microscopy. The evolution of both the morphologies and the electronic properties of the pristine and doped picene films have been carefully studied. With the increase of the K doping ratio, several novel ordered structures sequentially appear on the KxPicene (x= 0–4) film. Meanwhile, owing to the increase of charge transferring from K atoms to picene molecules, the lowest unoccupied molecular orbital state of the films is observed to shift toward the Fermi level. In particular, for K3.4Picene, this state splits into an upper unoccupied part and a lower occupied one when saddling the Fermi level. This may imply the presence of the electronic correlation effect.

MnBi2Te4is an antiferromagnetic topological insulator that has stimulated intense interest due to its exotic quantum phenomena and promising device applications. The surface structure is a determinant factor to understand the magnetic and topological behavior of MnBi2Te4, yet its precise atomic structure remains elusive. Here we discovered a surface collapse and reconstruction of few-layer MnBi2Te4exfoliated under delicate protection. Instead of the ideal septuple-layer structure in the bulk, the collapsed surface is shown to reconstruct as a Mn-doped Bi2Te3quintuple layer and a MnxBiyTe double layer with a clear van der Waals gap in between. Combined with first-principles calculations, such surface collapse is attributed to the abundant intrinsic Mn–Bi antisite defects and the tellurium vacancy in the exfoliated surface, which is further supported by in situannealing and electron irradiation experiments. Our results shed light on the understanding of the intricate surface-bulk correspondence of MnBi2Te4and provide an insightful perspective on the surface-related quantum measurements in MnBi2Te4few-layer devices.

In this study, the gene of γ-glutamyltranspeptidase (GGT) from Bacillus amyloliquefaciens(BaGGT) controlled by the Placpromoter was cloned into Bacillus subtilisto construct two recombinant vectors with either one or two signal peptides to drive extracellular secretion. After optimization, 90 ± 0.2 mg/L BaGGT was obtained when the inducing conditions were 24 h and 80 μM (IPTG). The properties of BaGGT were measured, showing that the optimal reaction conditions were 40 °C and pH 9.0 with 55.0 ± 0.5 U/mg enzymatic activity. Kmand Vmaxwere 0.214 mM and 88.13 μmol/min/mg. BaGGT could be stored for 72 h with 90% of the initial activity at 40 °C and retained more than 50% of the initial activity after being maintained at different pH values for 24 h. Finally, enzymatic synthesis of l-theanine was performed with the optimal conditions: 20 mM l-Gln, 100 mM ethylamine HCl, 0.5 U/mL BaGGT, incubated at 40 °C for 6 h, 200 rpm.

A novel α-amylase gene (BAA) from Bacillus amyloliquefacienswas cloned into Lactococcus lactis, designing two recombinant α-amylases to facilitate extracellular secretion. Following optimizing the expression conditions, the highest yield of BAA (88.12 mmol/L) was achieved upon 36 h induction and 5 ng/mL nisin concentration. Determining the enzymatic properties of BAA revealed its poor stability and activity at high temperatures, hindering its widespread application. Therefore, we used computer-aided design to generate a mutant, S275L, which exhibited significantly improved activity and thermostability: an 18.7% increase in enzymatic activity (3767.38 U/mg), a 10 °C increase in optimal temperature, and a 49.2% improvement in stability at 60 °C. Molecular dynamics simulations and force analysis confirmed these enhancements. Finally, the mutant S275L’s potential was further analyzed for starch hydrolysis on poultry feed. Therefore, the mutant S275L holds promising as an enzyme agent for enhanced feed digestibility and quality.

To investigate the effect of individual and collaborative fermentation on summer-autumn green tea (SAGT) quality. Liquid fermentation with individual inoculation of Aspergillus cristatus(ACFT), Aspergillus niger(ANFT) and mixed inoculation of A. cristatus/A. niger(MFT), respectively, with SAGT extracts (CT) as raw materials. The volatile organic compounds (VOCs), characteristic non-volatile compounds and sensory evaluation of tea samples were determined. The results showed a significant decrease in the content of tea polyphenols, carbohydrates and nongalloylated catechins (C, EC) and a significant increase in the amount of VOCs in MFT compared to ANFT and ACFT. The results of metabolic pathway analysis and sensory evaluation showed that ACFT went through the terpene and phenylpropanoic acid metabolic pathway, which produced large amounts of α-terpineol, phenethyl alcohol, and methyl salicylate, which in turn conferred ACFT with distinctly sweet, floral, and herbal aroma. ANFT produces large amounts of linalool oxides I and II, mainly through the linalool oxide metabolic pathway, making ANFT a distinctive aged and woody aroma. MFT may be due to the strong woody aroma of linalool oxides masking other weaker and better aromas, thus giving MFT a significant woody, herbal and stale aroma. This study provides new insights and a theoretical basis for mixed fungal fermentation to improve the quality of SAGT.

The growth of polycyclic aromatic hydrocarbon (PAH) molecular coronene film on various substrates and the subsequent doping of potassium under ultrahigh vacuum (UHV) conditions have been systematically investigated by low-temperature scanning tunneling microscopy and spectroscopy (STM/STS). The crystalline structures and molecular orientations of coronene thin films are both thickness-dependent and substrate-sensitive due to the competition between molecule–substrate interaction and intermolecular interaction. In mono- or bilayer films, coronene molecules are flat-lying on the surface with hexagonal lattice, whereas in multilayer films, the topmost molecules are in a standing-up but tilted configuration with rectangular lattice. In particular, a 2 × 1 superstructure with respect to that of bulk coronene is formed on thick KCl film. Furthermore, we have studied the potassium doped coronene monolayer and multilayer on Ag(100) and KCl/Ag(100) surface. For K-doped coronene monolayer, at certain doping ratio x= 3, the lowest unoccupied molecular orbital (LUMO) of coronene film moves to the Fermi level, and a splitting of the LUMO state is observed. Increased potassium doping would result in a filled LUMO state below the Fermi level. By contrast, no well-ordered structures are obtained in the K-doped coronene multilayers which are vulnerable to rather moderate annealing processes owing to their relatively weak bonding with the supporting substrates, implying a big challenge of growth of PAH thick films in vacuum. The differences in the crystal structures of coronene thin films compared with that in bulk crystals might shed insight on the controversies in the experimental results on the electronic properties of alkali-metal-doped PAHs.

Daqu is a crucial saccharifying and fermenting agent in the production of Baijiu, with GuaYi referring to the white fungal colonies on Daqu's surface, serving as a critical indicator for sensory evaluation. However, the correlation between distinct GuaYi and the consequent internal modifications in Daqu remains to be elucidated. Our investigation delineates that Heavy GuaYi Daqu (HGY), distinguished by an elevated prevalence of white microflora (notably Saccharomycopsis), sustains enhanced moisture levels internally. This environment is conducive to the proliferation of Aspergillusand Kroppenstedtia, resulting in significant increases of 50.95% and 40.75% in the concentrations of alcohols and pyrazines, respectively. Conversely, Light GuaYi Daqu (LGY) creates a comparatively arid environment, favoring Thermoascusand Staphylococcusgrowth, which is instrumental in the decomposition of complex biomolecules such as starch, reducing sugars, and proteins. These insights elucidate the nuanced interplay between GuaYi and Daqu's quality and stylistic attributes, providing an invaluable theoretical framework for the refinement of sensory evaluation standards for Daqu.

Sn-Bi based solders are used in electronic packaging for interconnection processes. However, the rate of research on the comprehensive performance of solders is difficult to match the rapid development of advanced manufacturing of integrated circuits, resulting in the inability to obtain interconnect structures with excellent reliability for electronic devices. To demand a more effective modification method, we chose to dope 1.0 wt. % In element in Sn58Bi-1Sb alloy. The strength, micromechanical properties and creep resistance of the solder were improved due to the combined effect of solid solution strengthening and diffusely distributed second phase strengthening. Furthermore, the addition of In element dramatically improved the thermal properties and wettability due to the generation of Bi3In5intermetallic compounds (88.9°C) and the activation energy of the solder wettability reaction was reduced to 247.36 J/mol. Notably, the addition of In element increased the amount of β-Sn phase deviation and decreased the Schmid factor value of β-Sn phase, resulting in a significant increase in the strength and micro-zone creep resistance. Under the action of current, a large amount of uniform Bi particle deviations and sub-crystalline structures persist in the β-Sn phase of the Sn58Bi-1Sb1In solder matrix. In the Cu/Sn58Bi-1Sb1In/Cu joints, many Bi particles are staggered in the β-Sn phase. Since the resistivity of the β-Sn phase is smaller than that of the Bi phase, the energization process leads to a possible further increase of the local currents at certain locations in the β-Sn phase, which reduces the electromigration resistance of the β-Sn phase. After energization, the biphasic twin structure with excellent electromigration resistance starts to degrade. The results show that the doping of In element comprehensively improves the performance of Sn58Bi-1Sb solder. It opens up a new idea for the design of alloying modification of tin-bismuth based solder.

An iron (Fe)-modified carbon dots (CDs) doped ZIF-8 zeolite imidazole metal-organic frame pyrolyzed composite (5Fe@NC) was prepared and then evaluated as a peroxydisulfate (PDS) activator for the oxidative removal of organic pollutants. The 5Fe@NC/PDS system not only has a good recovery performance, wide pH adaptability, and low activation energy, but also is resistant to environmental interference. The quenching experiments, electron paramagnetic resonance (EPR) detection, and electrochemical analysis all revealed that unlike the widely reported singlet oxygen (1O2) dominated nonradical mechanism, an electron transfer process (ETP) involving a surface bound PDS complex played the main role in pollutants’ degradation by 5Fe@NC/PDS system. The FeNx, defect, graphitic N and hydroxyl group (-OH) acting as active sites, prompted the 5Fe@NC-PDS complex to capture electrons (e−) from acetaminophen (ACT). This study provides a new approach for xFe@NCs rational design, and deepen the understanding of FeNxactivation mechanism of PDS in carbon nanomaterials.

There are two steps (alcoholic fermentation and acetic acid fermentation) in the production of fruit vinegar by liquid fermentation. The yeast alcoholic fermentation step plays an important role in the quality of apple vinegar. In this work, Candida tropicalisand aromatizing yeast were used in mixed alcoholic fermentation to improve the flavor of the apple vinegar. The total organic acid contents of apple cider and vinegar in mixed cultures were all higher than those in pure culture (Candida tropicalis). Umami and sweet free amino acid levels in mixed-culture apple vinegar (MCAV; 1236.71 and 858.25 mg/L, respectively) were significantly higher than those in pure-culture apple vinegar (PCAV; 1214.69 and 820.37 mg/L, respectively). The total esters, total alcohols, and total phenolics were also significantly increased in MCAV (282.36 g/L, 254.22 g/L and 47.49 g/L, respectively), fruit flavor and floral aromas in MCAV were higher than that in PCAV. In the principal component analysis (PCA), the integrative score for MCAV was higher than that for PCAV. Therefore, mixed cultures of Candida tropicalisand aromatizing yeast in alcoholic fermentation can effectively improve the flavor and quality of apple cider vinegar; more details about the mixed culture need to be investigated in the future.

In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting white dwarfs, low and high mass X-ray binaries, radio quiet and radio loud active galactic nuclei, tidal disruption events, and gamma-ray bursts. eXTP will be excellently suited to study one common aspect of these objects: their often transient nature. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.

The Wide Field Survey Telescope (WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China (USTC) and the Purple Mountain Observatory (PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for high-quality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands (u, g, rand i) at cadences from hourly/daily in the deep high-cadence survey (DHS) program, to semi-weekly in the wide field survey (WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31 (AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-zuniverse and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23 (u) and 24 mag (g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions, tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g≃ 25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) that monitors the southern sky.

Although the family of polycrystalline Cu2ZnSn(S,Se)4(CZTSSe) thin films are well-known light absorber materials for photovoltaic solar cells and have been studied extensively in the past, the behaviors of their grain boundary (GB) still remain elusive. By using a combination of experimental techniques, we have systematically investigated the compositions and electronic structures of the grain interior (GI) and GB of the polycrystalline CZTS, CZTSe and CZTSSe films at nanometer scales. In particular, we have for the first time independently determined the band edge positions for both the conduction band and the valence band using scanning tunneling spectroscopy. While the composition of GB was nearly the same as that of GI for both CZTS and CZTSe films, opposite band bending behaviors near GBs were discovered for them. For CZTS, both the conduction band and valence band were found to bend towards the forbidden gap near GBs, resulting in enhanced carrier recombination and relatively poor device performance. For CZTSe, in contrast, both the conduction band and valence band were found to bend away from the forbidden gap near GBs, which could be responsible for the relative better device performance due to the potentially impeded carrier recombination. In the case of CZTSSe thin film, by actively substituting Se with S near GBs, both conduction band and valence band at GBs were demonstrated to bend away from the forbidden gap, leading in principle to a lower carrier recombination at GBs and improved device performance. Our findings could provide a direction for manipulating the band bending between GB and GI to improve the performance of CZTSSe family solar cells.

In this paper, aiming at the characteristics of large mold and complex surface of automobile cover mold, the mold processing of cover is analyzed, especially the mold surface quality. Roughness prediction is an important concept in the field of machining and manufacture,especially for automobile cover mold manufacturing industry, not only to improve its quality of product, reduce wear and tear, but also to enhance its mechanical strength.

Acetobacter pasteurianusJST-S was screened from solid fermented grains of vinegar in China, identified by molecular analysis, and used for the production of purple sweet potato vinegar using purple sweet potato as the substrate. By orthogonal experiment, maximum total acid concentration (4.26% [v/v]) was achieved under optimized conditions as follows: fermentation time, 3.5 days; ethanol content, 9% v/v; and inoculum size, 8% v/v. During the production of purple potato vinegar, the anthocyanin concentration decreased from 652.07 to 301.73 μg/mL. The antioxidant activity of products, including diphenyl-picryl hydrazide radical-scavenging capacity (above 60%), reducing power (above 0.47), and hydroxyl radical-scavenging capacity (above 46%), showed positive linear regression (P< 0.01), which could be related with the changes in anthocyanin concentration and antioxidant activities at different stages of vinegar fermentation. The acetic acid and other non-phenolic antioxidants in purple sweet potato vinegar may have contributed to the antioxidant activities. Results of these studies may provide a reference for the industrial production of vinegar by liquid fermentation of purple sweet potato.

Histone acetylation and the families of enzymes responsible for controlling these epigenetic marks have been implicated in regulating T-cell maturation and phenotype. Here, we demonstrate a previously undefined role of histone deacetylase 11 (HDAC11) in regulating T-cell effector functions. Using EGFP-HDAC11 transgenic reporter mice, we found that HDAC11 expression was lower in effector relative to naive and central memory T-cell populations, and activation of resting T cells resulted in its decreased expression. Experiments using HDAC11 knockout (KO) mice revealed that T cells from these mice displayed enhanced proliferation, proinflammatory cytokine production, and effector molecule expression. In addition, HDAC11KO T cells had increased expression of Eomesodermin (Eomes)and TBX21(Tbet), transcription factors previously shown to regulate inflammatory cytokine and effector molecule production. Conversely, overexpression of HDAC11 resulted in decreased expression of these genes. Chromatin immunoprecipitation showed the presence of HDAC11 at the Eomesand Tbetgene promoters in resting T cells, where it rapidly disassociated following T-cell activation. In vivo, HDAC11KO T cells were refractory to tolerance induction. HDAC11KO T cells also mediated accelerated onset of acute graft-versus-host disease (GVHD) in a murine model, characterized by increased proliferation of T cells and expression of interferon-γ, tumor necrosis factor, and EOMES. In addition, adoptive transfer of HDAC11KO T cells resulted in significantly reduced tumor burden in a murine B-cell lymphoma model. Taken together, these data demonstrate a previously unknown role of HDAC11 as a negative epigenetic regulator of T-cell effector phenotype and function.

Histone acetylation and the families of enzymes responsible for controlling these epigenetic marks have been implicated in regulating T-cell maturation and phenotype. Here, we demonstrate a previously undefined role of histone deacetylase 11 (HDAC11) in regulating T-cell effector functions. Using EGFP-HDAC11 transgenic reporter mice, we found that HDAC11 expression was lower in effector relative to naive and central memory T-cell populations, and activation of resting T cells resulted in its decreased expression. Experiments using HDAC11 knockout (KO) mice revealed that T cells from these mice displayed enhanced proliferation, proinflammatory cytokine production, and effector molecule expression. In addition, HDAC11KO T cells had increased expression of Eomesodermin (Eomes) and TBX21 (Tbet), transcription factors previously shown to regulate inflammatory cytokine and effector molecule production. Conversely, overexpression of HDAC11 resulted in decreased expression of these genes. Chromatin immunoprecipitation showed the presence of HDAC11 at the Eomes and Tbet gene promoters in resting T cells, where it rapidly disassociated following T-cell activation. In vivo, HDAC11KO T cells were refractory to tolerance induction. HDAC11KO T cells also mediated accelerated onset of acute graft-versus-host disease (GVHD) in a murine model, characterized by increased proliferation of T cells and expression of interferon-γ, tumor necrosis factor, and EOMES. In addition, adoptive transfer of HDAC11KO T cells resulted in significantly reduced tumor burden in a murine B-cell lymphoma model. Taken together, these data demonstrate a previously unknown role of HDAC11 as a negative epigenetic regulator of T-cell effector phenotype and function.

Macrophages play critical, but opposite, roles in acute and chronic inflammation and cancer. In response to pathogens or injury, inflammatory macrophages express cytokines that stimulate cytotoxic T cells, whereas macrophages in neoplastic and parasitic diseases express anti-inflammatory cytokines that induce immune suppression and may promote resistance to T cell checkpoint inhibitors. Here we show that macrophage PI 3-kinase γ controls a critical switch between immune stimulation and suppression during inflammation and cancer. PI3Kγ signalling through Akt and mTor inhibits NFκB activation while stimulating C/EBPβ activation, thereby inducing a transcriptional program that promotes immune suppression during inflammation and tumour growth. By contrast, selective inactivation of macrophage PI3Kγ stimulates and prolongs NFκB activation and inhibits C/EBPβ activation, thus promoting an immunostimulatory transcriptional program that restores CD8+T cell activation and cytotoxicity. PI3Kγ synergizes with checkpoint inhibitor therapy to promote tumour regression and increased survival in mouse models of cancer. In addition, PI3Kγ-directed, anti-inflammatory gene expression can predict survival probability in cancer patients. Our work thus demonstrates that therapeutic targeting of intracellular signalling pathways that regulate the switch between macrophage polarization states can control immune suppression in cancer and other disorders.

Laser assisted machining is an effective method to machine advanced materials with the added benefits of longer tool life and increased material removal rates. While extensive studies have investigated the machining properties for laser assisted milling(LAML), few attempts have been made to extend LAML to machining parts with complex geometric features. A methodology for continuous path machining for LAML is developed by integration of a rotary and movable table into an ordinary milling machine with a laser beam system. The machining strategy and processing path are investigated to determine alignment of the machining path with the laser spot. In order to keep the material removal temperatures above the softening temperature of silicon nitride, the transformation is coordinated and the temperature interpolated, establishing a transient thermal model. The temperatures of the laser center and cutting zone are also carefully controlled to achieve optimal machining results and avoid thermal damage. These experiments indicate that the system results in no surface damage as well as good surface roughness, validating the application of this machining strategy and thermal model in the development of a new LAML system for continuous path processing of silicon nitride. The proposed approach can be easily applied in LAML system to achieve continuous processing and improve efficiency in laser assisted machining.