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To enhance the security of image data transmission, and address the weaknesses of existing image encryption schemes based on chaotic systems, particularly concerning resistance to differential attacks and the unstable performance of chaotic systems, this article introduces an improved four-dimensional chaotic system and integrates evolutionary operators to propose an image encryption scheme. Firstly, a method for generating pseudo-random sequences associated with the plaintext is designed. The change rate of the ciphertext pixel value exceeds 0.9967 after a slight modification of the plaintext pixel value, significantly improving the plaintext sensitivity and the scheme's ability to resist selected plaintext attacks. Secondly, an individual rearrangement operation is introduced to achieve bit-level scrambling, and pixel-level scrambling is achieved by selection strategy. Subsequently, crossover and mutation operations are incorporated into image encryption. To reflect the randomness of the pairing, we adopt the pseudo-random sequence generated by the chaotic system to control the crossover and mutation operators, and a diffusion operation is performed on selected pixel pairs. Finally, ciphertext feedback is applied. Experimental results and performance analysis demonstrate that the proposed scheme not only enhances the security of encrypted images but also effectively resists noise and cropping attacks. This method effectively meets the high-security requirements of images in network transmission and provides new ideas for further research in the field of image encryption. [ABSTRACT FROM AUTHOR]

Proppant transport is critical in hydraulic fractures and enhanced geothermal systems. Proppant transport is essentially a dense granular flow in narrow slots, and the Euler–Euler methods are commonly used to study the principle of proppant transport at the field scale. However, the simulated results cannot reproduce the laboratory observations well because some closure equations are not suitable for describing the quasi-static state of proppants after settlement, and only monodisperse granular flow is considered in simulations, which neglects the interaction between large and small particles. To improve the applicability of the numerical simulation of proppant transport in hydraulic fracturing treatment, binary-size proppant transport numerical simulations using the Eulerian multifluid method (EMM) are performed in this study. First, the motion characteristics of the suspended and settled proppants were analyzed using the kinetic theory of granular flow (KTGF) and the frictional theory of viscous particles. Thereafter, the solid–liquid momentum exchange considering the wall retardation effect and the solid–solid momentum exchange considering the endurable contact among the particles are discussed. Finally, the numerical results are qualitatively and quantitatively verified using proppant transport experiments and particle image velocimetry tests. The combination of traditional KTGF models and frictional models exhibits better performance than the modified KTGF models when considering the inertia flow regime in the proppant transport simulation, and the contribution of viscous-particle cohesion to friction must be considered. Notably, the simulated results are close to the experimental results for the development process of sand banks and the velocity distribution of particles. This verified method is efficient in computing and it will provide new insights into the pumping procedure design for hydraulic fracturing. [ABSTRACT FROM AUTHOR]

This paper proposes a new image encryption algorithm based on chaos map systems, hash algorithm, and Josephus permutation. The algorithm consists of chaos initialization, pixel position permutation, and pixel information diffusion. The algorithm's initialization is generated by the original image, which has a high sensitivity to the initial value. The permutation step length is composed of Josephus permutation and gray curve permutation, which completely disturbs the pixel distribution. The diffusion process is composed of cross operation and ciphertext feedback, which breaks the strong correlation between pixels. The simulation results of the encryption algorithm are used to analyze its information entropy, the correlation between elements, and other indicators. The ciphertext image is attacked in several ways, and we analyzed its defense ability. Simulation results show that the algorithm can effectively encrypt image information and has a good defense against various attacks. [ABSTRACT FROM AUTHOR]

• MeHg photodegradation commonly occurs in paddy water during rice growth. • The photodegradation rates are comparable to those found in natural waters. • pH and DOC contents negatively impact MeHG degradation in paddy water. • MeHg photodegradation in paddy water moderately reduces MeHG accumulation in rice. • MeHg photodegradation in paddy water greatly limits its export to downstream systems. Photodegradation is critical to reduce the potent neurotoxic methylmercury (MeHg) in water and its subsequent accumulation along food chains. However, this process has been largely ignored in rice paddies, which are hotspots of MeHg production and receive about a quarter of the world's developed freshwater resources. Here, we reported that significant MeHg photodegradation, primarily mediated by hydroxyl radicals, occurs in the overlying water during rice growth. By incorporating field-measured light interception into a rice paddy biogeochemistry model, as well as photodegradation rates obtained from 42 paddy soils stretching ∼3500 km across China, we estimated that photodegradation reduced MeHg concentrations in paddy water and rice by 82 % and 11 %, respectively. Without photodegradation, paddy water could be a significant MeHg source for downstream ecosystems, with an annual export of 178 − 856 kg MeHg to downstream waters in China, the largest rice producer. These findings suggest that photodegradation in paddy water is critical for preventing greater quantities of MeHg entering human food webs. [Display omitted] [ABSTRACT FROM AUTHOR]

Hydroquinone (HQ) is produced commercially from benzene by multi‐step Hock‐type processes with equivalent amounts of acetone as side‐product. We describe an efficient biocatalytic alternative using the cytochrome P450‐BM3 monooxygenase. Since the wildtype enzyme does not accept benzene, a semi‐rational protein engineering strategy was developed. Highly active mutants were obtained which transform benzene in a one‐pot sequence first into phenol and then regioselectively into HQ without any overoxidation. A computational study shows that the chemoselective oxidation of phenol by the P450‐BM3 variant A82F/A328F leads to the regioselective formation of an epoxide intermediate at the C3=C4 double bond, which departs from the binding pocket and then undergoes fragmentation in aqueous medium with exclusive formation of HQ. As a practical application, an E. coli designer cell system was constructed, which enables the cascade transformation of benzene into the natural product arbutin, which has anti‐inflammatory and anti‐bacterial activities. [ABSTRACT FROM AUTHOR]

Hydroquinone (HQ) is produced commercially from benzene by multi‐step Hock‐type processes with equivalent amounts of acetone as side‐product. We describe an efficient biocatalytic alternative using the cytochrome P450‐BM3 monooxygenase. Since the wildtype enzyme does not accept benzene, a semi‐rational protein engineering strategy was developed. Highly active mutants were obtained which transform benzene in a one‐pot sequence first into phenol and then regioselectively into HQ without any overoxidation. A computational study shows that the chemoselective oxidation of phenol by the P450‐BM3 variant A82F/A328F leads to the regioselective formation of an epoxide intermediate at the C3=C4 double bond, which departs from the binding pocket and then undergoes fragmentation in aqueous medium with exclusive formation of HQ. As a practical application, an E. coli designer cell system was constructed, which enables the cascade transformation of benzene into the natural product arbutin, which has anti‐inflammatory and anti‐bacterial activities. Unique enzymatic one‐pot dihydroxylation of benzene to hydroquinone: A mutant of a cytochrome P450 monooxygenase catalyzes this challenging transformation with no overoxidation, enabling, among other things, the cascade synthesis of biologically active arbutin. [ABSTRACT FROM AUTHOR]

Although the circulation of avian influenza viruses in humans is limited, they can be transmitted from Aves (birds) to humans, representing a great challenge. Herein, we suggest that influenza viruses from Aves might exist in a mineralized state owing to the high calcium concentrations in the avian intestine. Using two typical influenza viruses as examples, we demonstrate that these viruses can self-mineralize in simulated avian intestinal fluid, resulting in egg-like virus-mineral structured composites. The mineralized viruses are more robust, with enhanced infectivity and thermostability. More importantly, the mineral exterior of mineralized viruses can alter their cell internalization, expanding the possible tropisms. The discovery of a mineralized state of influenza viruses highlights the integration of nanomaterials and viruses in the environment, which provides a new understanding of avian influenza infection and its control. [ABSTRACT FROM AUTHOR]

Although the circulation of avian influenza viruses in humans is limited, they can be transmitted from Aves (birds) to humans, representing a great challenge. Herein, we suggest that influenza viruses from Aves might exist in a mineralized state owing to the high calcium concentrations in the avian intestine. Using two typical influenza viruses as examples, we demonstrate that these viruses can self-mineralize in simulated avian intestinal fluid, resulting in egg-like virus-mineral structured composites. The mineralized viruses are more robust, with enhanced infectivity and thermostability. More importantly, the mineral exterior of mineralized viruses can alter their cell internalization, expanding the possible tropisms. The discovery of a mineralized state of influenza viruses highlights the integration of nanomaterials and viruses in the environment, which provides a new understanding of avian influenza infection and its control. [ABSTRACT FROM AUTHOR]

Synovial fibrosis is a driver in the progression of osteoarthritis (OA). Fibroblast growth factor 10 (FGF10) has prominent anti-fibrotic effects in many diseases. Thus, we explored the anti-fibrosis effects of FGF10 in OA synovial tissue. In vitro , fibroblast-like synoviocytes (FLSs) were isolated from OA synovial tissue and stimulated with TGF-β to establish a cell model of fibrosis. After treatment with FGF10, we assessed the effects on FLS proliferation and migration using CCK-8, EdU, and scratch assays, and collagen production was observed using Sirius Red Stain. The JAK2/STAT3 pathway and expression of fibrotic markers were evaluated through western blotting (WB) and immunofluorescence (IF). In vivo , we treated mice with OA induced by surgical destabilization of the medial meniscus (DMM) with FGF10 and assessed the anti-OA effect using histological and immunohistochemical (IHC) staining of MMP13, and fibrosis was evaluated using HE and Masson's trichrome staining. The expression of IL-6/JAK2/STAT3 pathway components was determined using ELISA, WB, IHC, and IF. In vitro , FGF10 inhibited TGF-β-induced FLS proliferation and migration, decreased collagen deposition, and improved synovial fibrosis. Moreover, FGF10 mitigated synovial fibrosis and improved the symptoms of OA in DMM-induced OA mice. Overall, FGF10 had promising anti-fibrotic effects on FLSs and improved OA symptoms in mice. The IL-6/STAT3/JAK2 pathway plays key roles in the anti-fibrosis effect of FGF10. This study is the first to demonstrate that FGF10 inhibited synovial fibrosis and attenuated the progression of OA by inhibiting the IL-6/JAK2/STAT3 pathway. • Synovial fibrosis is one of the important factors that promote the progression of osteoarthritis. Fibroblast growth factor 10 (FGF10) has a good anti-fibrosis effect and can delay the progression of osteoarthritis. Therefore, FGF10 was used for the first time in the treatment of synovial fibrosis in osteoarthritis in vitro and vivo, and the role of IL-6/JAK2/STAT3 signaling pathway is further discussed. It provides a new diagnosis and treatment idea for osteoarthritis. [ABSTRACT FROM AUTHOR]

Respiratory viruses are recognized as serious causes of morbidity and mortality in lower respiratory tract infections in patients. Isothermal amplification assays are increasingly used in their detection because of their rapidity, simplicity and cost-effectiveness, when compared to traditional molecular diagnostic methods. However, systematic assessment of these assays in the clinical settings is rarely reported. MEDLINE (Pubmed) searches were done analysing subject headings and words in the abstract related to isothermal amplification assay and virus. Selected loop-mediated isothermal amplification assays (LAMP) for respiratory syncytial virus (RSV), human metapneumovirus (HMPV) and adenovirus (ADV) as well as a reverse transcription genome exponential amplification reaction assay (GEAR) for human rhinovirus (HRV) were clinically evaluated in a head to head comparison against a two-tube multiplex reverse transcription-PCR (RT-PCR) assay (two-tube assay) using 634 respiratory specimens from children with pneumonia from different regions in China. Discrepant results between isothermal amplification assays and the two-tube assay were resolved by sequencing. A comparison of sensitivities of each selected isothermal amplification assay among province, gender, and age groups was also analyzed. A total of 634 respiratory specimens selected from Hebei Province children's hospital and Hunan Provincial Center for Disease Control and Prevention were tested. The overall detection rate (number of positive specimens/total specimens) for viruses tested by Reverse transcription (RT)-LAMP/LAMP/RT-GEAR was 35.9% while the detection rate was 46.2% by the two-tube assay. The sensitivity of each isothermal amplification assay was 88.4%, 74.3%, 100% and 73.6% for RSV, HMPV, ADV and HRV, respectively. No false positives were found in isothermal amplification assays. All the discrepant negative results by isothermal amplification assays were confirmed false negatives by sequencing. The LAMP assay for ADV showed significant consistency with the two-tube assay. A higher sensitivity of RSV detection was found in Hunan Province than in Hebei Province (P = 0.01). Among different age groups, a higher sensitivity of RSV detection was also found in children older than 1 year, when compared to children less than 1 year (P = 0.01). The clinical performance of the selected isothermal amplification assays for different viruses varies. Multiple-center assessment is critical to evaluate isothermal amplification assays, especially for RNA viruses, for their broad use in clinical hospital. The selected LAMP assay for the detection of ADV is reliable and has great potential for use in clinics; however, the sensitivities of the LAMP/GEAR assays for the detection of RSV, HMPV and HRV need to be further improved to meet clinical requirements, although a statistical difference in sensitivity was only found for the selected LAMP assay for RSV. [ABSTRACT FROM AUTHOR]

Developing vaccine formulations with excellent thermostability and immunogenicity remains a great challenge. By in situ encapsulating a live-attenuated strain of human enterovirus 71 (EV71) in alumina, we obtained a robust vaccine formulation named EV71@NanoAlum, which features significantly enhanced thermostability and immunogenicity. This attempt follows a material-based tactic for vaccine improvement. [ABSTRACT FROM AUTHOR]

Organic, inorganic, and biological pollutants are typical water contaminants and they seriously affect water quality. In this study, we suggested that a novel multifunctional Ag 3 PO 4 loaded hydroxyapatite (HAP) material can remove the typical pollutants from water. The Ag 3 PO 4 /HAP composites were synthesized facilely via in-situ precipitation of Ag 3 PO 4 on the pre-existing HAP nanowires. By optimizing the composition of Ag 3 PO 4 and HAP, the material could achieve an optimal photocatalytic activity to decompose rhodamine B (RhB), methyl orange (MO) and methylene blue (MB) under visible light irradiations with enhanced pH stability. Besides, the adsorption of Pb(II) on the Ag 3 PO 4 /HAP reached a maximum capacity of 250 mg/g and this value was approximately three times as that of pure HAP. Furthermore, the composite material exhibited excellent antibacterial activities towards gram-negative bacterium ( Escherichia coli ) and gram-positive bacterium ( Stphylococcus aureus ). The results highlighted the cooperative effect between Ag 3 PO 4 and hydroxyapatite (HAP). The simultaneous removals of dyes, toxic metal ions, and bacteria with a high efficiency followed an easy approach for the purification of contaminated water via the rationally designed material, in which the Ag 3 PO 4 /HAP composite might be developed as a general water treatment material with multiple functions. [ABSTRACT FROM AUTHOR]

Radial profile measurement of Zeff using visible bremsstrahlung (5300 Å) in the Large Helical Device (LHD) has often encountered difficulties because the intensity profile was largely deformed by the nonuniform visible bremsstrahlung emissions from the edge ergodic layer surrounding the core plasma. A space-resolved flat-field extreme ultraviolet (EUV) spectrometer has been newly adopted to measure the Zeff profile using the EUV bremsstrahlung continuum in the wavelength range of 70-75 Å. The EUV bremsstrahlung intensity profiles have been measured and checked for all the magnetic configurations with totally different magnetic field structures in the ergodic layer of LHD. It is found that the nonuniform bremsstrahlung emission from the thick ergodic layer can be entirely eliminated by use of the EUV emission with relatively high photon energy of 170 eV. As a result, the Zeff profile can be successfully measured for most of discharges regardless of magnetic field structures of the ergodic layer. The Zeff profiles measured in the EUV range are compared with those measured in the visible range at a magnetic configuration with the thinnest ergodic layer thickness. The result verifies that the use of the EUV bremsstrahlung continuum is an alternative way for the Zeff measurement in toroidal plasmas with nonuniform bremsstrahlung emissions at the edge. Typical results from the EUV bremsstrahlung measurement are presented showing a fairly flat Zeff profile with error bars of ±14%. [ABSTRACT FROM AUTHOR]

Morphological control of photocatalysts is an important way to improve photocatalytic activity. Herein, we design a carbon-doped mesoporous g-C 3 N 4 nanoreactor by combining the self-assembly method of supramolecular precursors with the bubble template method. The mesoporous structure can increase the utilization rate of light absorption. Furthermore, the C atoms replace the position of bridging N atoms may generate delocalized large π bonds, both of which can facilitate photocatalysis. This nanoreactor coupled with larger specific surface area and faster electronic transmission efficiency shows an outstanding performance in photocatalytic RhB degradation (97%, 15 min) and reducing CO 2 into CO (60.82 μmol/g, 5h). The C-doped mesoporous g-C 3 N 4 nanoreactor would provide some practical reference for environmental improvements and clean energy production. [Display omitted] • Carbon-doped porous g-C 3 N 4 photocatalyst is synthesized. • Glucose serves as both a bubble template and a carbon dopant. • CPCN-2 exhibits superior photocatalytic activity and stability in the experiments. • Possible mechanism based on CPCN-2 in the photocatalytic process is proposed. [ABSTRACT FROM AUTHOR]

• Reserch highlight 1:A typical physical architecture of the multifunctional charging station with photovoltaic power generation and battery energy storage was designed. Then considering the market price signal, charging load, PV power fluctuation and other uncertain factors, an energy management model was established to maximize the overall operating benefits. • Reserch highlight 2:An intelligent energy management architecture based on machine learning was proposed in order to improve the intelligence level of charging stations to achieve multi-functional integration and optimal operation of charging stations in the most convenient and economical way. • Reserch highlight 3:Power prediction algorithm based deep learning was implemented to meet the predictive requirement of charging station operation scenarios under uncertain conditions. • Reserch highlight 4:.Optimization decision making algorithm based deep reinforcement learning was implemented to meet the optimization decision-making requirement of energy management for multifunctional charging stations under uncertain conditions. The machine-learning based approach to energy management of multifunctional charging stations that meets the needs in the context of "carbon neutrality". The method takes multifunctional charging station as the research object, considers the uncertainty elements such as market price signal, charging load, and the change of photovoltaic power generation, and aims at maximizing the comprehensive operation efficiency of charging station in the decision cycle, realizes the prediction of power generation and load power by using deep learning method, and obtains the optimal energy management strategy by reinforcement learning, and realizes intelligent management and operation of multifunctional charging station. A typical case study is presented and simulation analysis is carried out for typical cases to verify the correctness and effectiveness of the method. It is shown that the method can effectively cope with the uncertain elements in the operation of multifunctional charging stations, reduce the hardware configuration and manual operation and maintenance costs of charging stations while ensuring safety constraints, and effectively improve the energy utilization efficiency and economy of the whole charging station. [ABSTRACT FROM AUTHOR]

Arbutin (also called β-arbutin) is a natural product occurring in the leaves of a variety of different plants, the bearberries of the Ericaceae and Saxifragaceae families being prominent examples. It is a β-glucoside derived from hydroquinone (HQ; 1,4-dihydroxybenzene). Arbutin has been identified in traditional Chinese folk medicines as having, inter alia, anti-microbial, anti-oxidant, and anti-inflammatory properties that useful in the treatment of different ailments including urinary diseases. Today, it is also used worldwide for the treatment of skin ailments by way of depigmenting, which means that arbutin is a component of many products in the cosmetics and healthcare industries. It is also relevant in the food industry. Hundreds of publications have appeared describing the isolation, structure determination, toxicology, synthesis, and biological properties of arbutin as well as the molecular mechanism of melanogenesis (tyrosinase inhibition). This review covers the most important aspects with special emphasis on the chemical and biocatalytic methods for the production of arbutin. [ABSTRACT FROM AUTHOR]

In September 2011, Zhuonai Lake (ZL) in the northeast of Hoh Xil (HX) on the Qinghai–Tibet Plateau (QTP) broke out. The outburst event seriously changed the environmental hydraulics in this region. Due to the insufficient temporal resolution of observations, it is challenging to assess the impact of this event on short-period variations of water volumes in three lakes downstream of ZL. Combining multisource remote sensing data, we constructed long and high-temporal-resolution time series for the lake level, area, and lake water storage (LWS) of Kusai Lake (KL) to characterize the variabilities before and after the outburst. The water level, area, and LWS time series contain 1051 samples from 1990 to 2022, with uncertainties of 0.16 m, 2.5 km2, and 0.016 km3, respectively. The accuracies verified using the Database for Hydrological Time Series of Inland Waters (DAHITI) are 0.26 m, 2.64 km2, and 0.08 km3 for water level, area, and LWS, respectively. We characterized the LWS variations during the past 30 years based on the high temporal resolution LWS time series. Before the outburst, the 1-year and 3.5-year variations dominated the LWS time series, and there was no obvious semi-annual signal. After the outburst, the 3.5-year variation disappeared, and a strong semi-annual oscillation was observed. From 2012 to 2015, the periodic LWS variations in KL were disturbed by the ZL outburst and the subsequent outflow of KL led by the outburst. Regular cyclic signals have been restored since 2016, with an amplified annual fluctuation. By analysis, precipitation, evaporation, and glacier area change are excluded as driving factors of the pattern change in LWS variations of KL. It can be concluded that the altered recharge pattern of KL triggered by the outburst directly resulted in the observed changes in TWS behavior. For the first time, we identified the periodic patterns of LWS variations of KL during the past 30 years and revealed that the ZL outburst event significantly influenced these patterns. This finding contributes to the comprehensive understanding of the effects of the ZL outburst on downstream lake dynamics. Furthermore, the presented procedure for constructing long and high-resolution time series of LWS allows for monitoring and characterizing the short-period variabilities of Tibetan lakes that lack hydrological data. [ABSTRACT FROM AUTHOR]

Die enzymatische Benzol‐Dihydroxylierung zu Hydrochinon im Eintopfverfahren wird von A. Li, M. T. Reetz et al. in ihrer Zuschrift auf S. 774 vorgestellt. Eine Mutante einer Cytochrom‐P450‐Monooxygenase, die durch halbgezieltes Protein‐Engineering erhalten wurde, katalysiert die anspruchsvolle Umwandlung ohne Überoxidation, sodass unter anderem Synthesekaskaden für biologisch aktives Arbutin in einem maßgeschneiderten Escherichia‐coli‐Zellsystem möglich werden. [ABSTRACT FROM AUTHOR]

The unique enzymatic one‐pot dihydroxylation of benzene to hydroquinone can be achieved as described by A. Li, M. T. Reetz et al. in their Communication on page 764 ff. A mutant of a cytochrome P450 monooxygenase obtained by a semirational protein engineering strategy catalyzes this challenging transformation with no overoxidation, enabling, among other things, the cascade synthesis of biologically active arbutin by a constructed Escherichia coli designer cell system. [ABSTRACT FROM AUTHOR]

Polymer electrolytes have great potential to realize solid‐state lithium metal batteries with high energy density and intrinsic safety. However, the poor mechanical strength and uncontrolled electrolyte/electrode interface cannot guarantee the stable operation during long‐term cycling. Herein, a supramolecular polyurethane material reinforced by aromatic charge‐transfer interactions is synthesized as electrolyte matrix with high stiffness, excellent toughness, and unique mechanical energy dissipation capacity. The optimized electrolyte network can dynamically adapt to the volume fluctuating Li metal and, importantly, eliminate stress‐concentrating behavior under deformed state. As a result, the Li/Li symmetric cells can stably work for more than 3500 h without short circuit. And the LiFePO4/Li batteries show superior electrochemical performance over 1200 cycles with a capacity retention of 95.4% at 0.33 C. The supramolecular approach to tune the mechanical properties of the polymers is believed to provide a new strategy for designing solid electrolytes with desirable comprehensive mechanical properties for solid‐state batteries. [ABSTRACT FROM AUTHOR]

Vogelgrippe‐Viren können auch Menschen infizieren, über den Übertragungsweg ist aber nur wenig bekannt. In der Zuschrift auf S. 13088 schlagen R. Tang et al. vor, dass die Viren in Vögeln in einem mineralisierten Zustand in Eierschalen‐artigen Strukturen vorliegen. Die mineralisierten Viren sind robuster, infektiöser und temperaturbeständiger. Die mineralische Hülle um die Viren ändert außerdem ihr Zellaufnahmeverhalten und eröffnet ihnen dadurch neue Möglichkeiten. [ABSTRACT FROM AUTHOR]

BACKGROUND: Digital impression technology has been widely used in the oral field. Compared with traditional impression technology, it is more convenient and accurate. OBJECTIVE: To explore the application of digital prosthesis for repairing palatal fistula in rabbits. METHODS: The rabbit models of palatal fistula were established by surgery. One month later, 10 rabbit models of palatal fistula were scanned by digital intraoral scanning system. The medical silicone rubber prosthesis for palatal fistula was manufactured by digital impression technology and digital design. After wearing the prosthesis, the accuracy, retention and sealing properties of the prosthesis were examined. The study was approved by the Laboratory Animal Ethical Committee of Hospital of Stomatology, Southwest Medical University. RESULTS AND CONCLUSION: After digital prosthesis repaired palatal fistula, the accuracy, retention and sealing properties of the prosthesis were good. To conclude, the digital prosthesis for palatal fistula repair by digital impression technology achieves accurate repair, and has certain clinical values. [ABSTRACT FROM AUTHOR]

• Leucine145 of α-glucosidase AglA is identified as the critical amino acid residue for catalytic activity. • Catalytic efficiency (k cat / K m) of mutant L145V is increased by 7.2-fold. • The production of α-arbutin produced by Escherichia coli BL21(DE3) cells harboring mutant L145V is 4.7-fold higher than that of wild type AglA. • MD shed light on the possible reasons behind the greatly enhanced activity of mutant L145V. The α-glucosidase AglA from Xanthomonas campestris suffers from low catalytic activity for α-arbutin production, which leads to unsatisfied productivity. To address this issue, herein, the critical amino acid residue Leucine145 of α-glucosidase AglA, which locates on the loop adjacent to maltose binding domain, is identified with potential capability of affecting the enzyme activity with the aid of computational analysis. Site-directed and saturation mutagenesis on this key residue is performed, and the best mutant L145V with 7.2-fold improvement in catalytic efficiency (k cat / K m) is achieved. Following maltose hydrolysis test and α-arbutin production by whole cell biotransformation further demonstrate that L145V has the most excellent catalytic performance. The production of α-arbutin produced by Escherichia coli BL21(DE3) cells harboring mutant L145V reaches 63.1 mM within 3 h, which is 4.7-fold higher than that of wild type AglA. Finally, molecular dynamics simulations studies provide molecular insights into the possible maltose binding poses, and shed light on the possible reasons behind the greatly enhanced activity of mutant L145V. These results reveal critical roles of residue L145 of α-glucosidase AglA in regulating catalytic activity, which will be very useful for guiding the further engineering of other glucosidases. [Display omitted] [ABSTRACT FROM AUTHOR]

A grazing-incidence flat-field extreme ultraviolet (EUV) spectrometer has been newly developed in HL-2A tokamak. Typical spectral lines are observed from intrinsic impurities of carbon, oxygen, iron, and extrinsic impurity of helium in the wavelength range of 20 Å-500 Å. Bremsstrahlung continuum is measured at different electron densities of HL-2A discharges to calibrate absolute sensitivity of the EUV spectrometer system and to measure effective ionic charge, Zeff. The sensitivity of a vacuum ultraviolet (VUV) spectrometer system is also absolutely calibrated in overlapped wavelength range of 300 Å-500 Å by comparing the intensity between VUV and EUV line emissions. [ABSTRACT FROM AUTHOR]

Acid treatment is widely used for exploiting tight limestone reservoirs, and how acid affects the microstructure and mechanical property of tight limestone needs deeper understanding. Tight limestone cores from Middle Ordovician Yijianfang Formation in Tarim Basin, China, were collected to conduct acid coreflooding tests, simulating acid–rock reaction process between tight limestone and gelled acid or crosslinked acid. After that, surface indentation tests were conducted to characterize the effect of acid–rock reaction on the mechanical properties of tight limestone. Microscopic characteristics of dissolution in limestone were evaluated by scanning electron microscope. The results indicated that limestone samples exhibited ultra-low porosity of less than 2.5%, ultra-low permeability of less than 6.00 × 10−17 m2 and tight microstructure with compactive grains and few intercrystal pores. Acid could hardly penetrate deep into the core samples with continuously high pumping pressure up to 8 MPa, showing that acid–rock reaction mainly occurred on the rock inlet surface. The size of dissolved pores and corrosion fractures created by acid–rock reaction were closely correlated with acid type and acid concentration, reflecting the changing rules of mechanical properties. Gelled acid could penetrate into the whole rock inlet surface and the size of dissolved pores and corrosion fractures evidently enlarged as acid concentration increased, comparable with the monotonically decreasing trend of surface hardness and Young's modulus. Crosslinked acid mainly penetrated into partial areas of the rock inlet surface and the size of dissolved pores and corrosion fractures increased slightly, consist with the phenomenon that surface hardness showed volatility and Young's modulus reduced stably. [ABSTRACT FROM AUTHOR]

Accessory proteins play important roles in the interaction between coronaviruses and their hosts. Accordingly, a comprehensive study of the compositional diversity and evolutionary patterns of accessory proteins is critical to understanding the host adaptation and epidemic variation of coronaviruses. Here, we developed a standardized genome annotation tool for coronavirus (CoroAnnoter) by combining open reading frame prediction, transcription regulatory sequence recognition and homologous alignment. Using CoroAnnoter, we annotated 39 representative coronavirus strains to form a compositional profile for all of the accessary proteins. Large variations were observed in the number of accessory proteins of 1–10 for different coronaviruses, with SARS-CoV-2 and SARS-CoV having the most (9 and 10, respectively). The variation between SARS-CoV and SARS-CoV-2 accessory proteins could be traced back to related coronaviruses in other hosts. The genomic distribution of accessory proteins had significant intra-genus conservation and inter-genus diversity and could be grouped into 1, 4, 2 and 1 types for alpha-, beta-, gamma-, and delta-coronaviruses, respectively. Evolutionary analysis suggested that accessory proteins are more conservative locating before the N-terminal of proteins E and M (E-M), while they are more diverse after these proteins. Furthermore, comparison of virus-host interaction networks of SARS-CoV-2 and SARS-CoV accessory proteins showed that they share multiple antiviral signaling pathways, those involved in the apoptotic process, viral life cycle and response to oxidative stress. In summary, our study provides a tool for coronavirus genome annotation and builds a comprehensive profile for coronavirus accessory proteins covering their composition, classification, evolutionary pattern and host interaction. [ABSTRACT FROM AUTHOR]

In this paper, a deep reinforcement learning-based energy optimization management method for hydrogen-electric coupling system is proposed for the conversion and utilization and joint optimization operation of hydrogen, wind and solar energy forms considering information uncertainty on the demand side of smart grid. Based on the wind energy, photovoltaic energy generation and load forecast information, the method uses deep Q network to simulate the energy management strategy set of the hydrogen-electric coupling system, and obtains the optimal strategy through reinforcement learning to finally realize the optimal operation of the hydrogen-electric coupling system based on the demand response. Firstly, based on the energy management model, a research framework and equipment model for integrated energy systems is established. On the basis of fundamental theories of reinforcement learning framework, Q-learning algorithm and DQN algorithm, the empirical replay mechanism and freezing parameter mechanism to improve the performance of DQN are analyzed, and the energy management and optimization of integrated energy system is completed with the objective of economy. By comparing the performance of DQN algorithms with different parameters in integrated energy system energy management, the simulation results demonstrate the improvement of algorithm performance after inheriting the set of strategies, and verify the feasibility and superiority of deep reinforcement learning compared to genetic algorithm in integrated energy system energy management applications. • A hydrogen-electric coupling regional comprehensive energy system was established. • Deep reinforcement learning algorithm is used to manage energy system. • Hydrogen energy as the main energy storage mode was investigated. • The hydrogen-electric coupling integrated energy system was optimized. [ABSTRACT FROM AUTHOR]

In unconventional reservoir slickwater fracturing, a large flow rate of slickwater with proppant is injected into the fracture network to create a complex solid-liquid two-phase flow. To obtain the flow pattern, quantitative testing methods must be explored based on conventional proppant transport laydown qualitative observation experiments. Optical visualization of the flow field was achieved by improving the structure of the flat plate fracture experimental unit, followed by particle image data acquisition of the fracturing fluid-proppant two-phase flow field using laser particle image velocimetry on the constructed experimental setup. The image acquisition parameters were optimized based on the proppant particle exposure characteristics, and a method was developed to enhance the proppant-tracer particle image for separation. Based on particle center detection, a model for proppant particle velocity calculation was established based on quasi-rigidity theory, and the validity of the model was verified using an artificial flow field. According to the experimental test and calculation results of the two-phase flow field with different proppant particle sizes, types, and different flow regimes, such as turbulent and laminar flow, the designed device and the established quantitative test and calculation method of the solid-liquid two-phase flow field can better adapt to the testing problem of the proppant transport velocity field in unconventional fracturing, and aid further quantitative studies of the proppant transport law. • Established a PIV/PTV experiment equipment to test fracturing fluid and proppant velocity field for the first time. • Two-phase separation, enhancement and matching algorithms based on exposure response difference are proposed. • The accuracy and reliability of the algorithm are verified by the artificial particle field. • This method provides a micro perspective on proppant transport and fluid flow, going beyond macro sand placement analysis. [ABSTRACT FROM AUTHOR]

Spin transfer torque magnetic random-access memory is widely considered as a promising candidate for a next generation cache, with a core device of magnetic tunnel junction. The MgO/CoFeB/W/CoFeB/MgO structure as recording layer for magnetic tunnel junctions is of great interest due to features such as strong perpendicular magnetic anisotropy (PMA) and thermal stability. However, the origin of correlation between PMA and interlayer exchange coupling (IEC) in this structure remains unclear. In this paper, we investigate the PMA and IEC in the MgO/CoFe/W/CoFe/MgO structure with first-principles calculation. IEC with long and short period oscillations is observed, which results in much different magnetic anisotropy energies at CoFe/W interface in MgO/CoFe/W/CoFe/MgO structure compared to MgO/CoFe/W structure. Furthermore, we find an oscillation of magnetic anisotropy energies in ferromagnetically coupled MgO/CoFe/W/CoFe/MgO structure. According to k-space and band-decomposed charge-density analyses, this oscillation can be elucidated with quantum well states on spin-up states near Fermi energy within W layers. Thus, the correlation between PMA and IEC is explained by quantum well states. These findings provide comprehensive understanding of PMA and IEC in double-interface structures and pave a new way to modulate PMA with quantum well states in heavy metal layers. [ABSTRACT FROM AUTHOR]

[Display omitted] • THz broadband amplitude modulation of flexible FNLC materials under magnetic field. • Using microfluidic chip to reduce the absorption of THz waves in H 2 O. • Increasing magnetic fluid maximum MD to 78% by using topological defects of LC. • The experimental results lay a foundation for liquid film THz modulator. In recent years, solid state terahertz (THz) modulators have obtained rapid progress with the widespread use of two-dimensional (2D) materials in the field of THz; however, challenges remain in preparing flexible THz modulators. In this study, flexible ferromagnetic nematic materials were prepared by doping thermotropic nematic liquid crystals 5CB into magnetic fluids, and the influence of water was reduced by a self-made cyclic olefin copolymer (COC) microfluidic chip. THz modulation characteristics of magnetic fluid and ferromagnetic nematic liquid crystal (FNLC) under the induction of external magnetic field were compared using a THz time domain spectroscopy system. Under the action of a 91 mT magnetic field, the magnetic fluid has a maximum modulation depth (MD) of 54%. Under the same magnetic field, the maximum MD of the FNLC materials increase to 78% because of the rearrangement of Fe 3 O 4 nanoparticles induced by the topological defect of the liquid crystal. We demonstrate that the magneto-optical effect is significantly enhanced in the ferromagnetic nematic liquid crystal hybrid system. This strategy of doping thermotropic nematic liquid crystals to enhance the magneto-optical effect has great potential for THz filtering, modulation, and sensing applications. [ABSTRACT FROM AUTHOR]

Multi-walled carbon nanotube arrays (MWCNTAs) were grown by thermal chemical vapor deposition (TCVD) in a horizontal furnace reactor. The scanning electron microscopy (SEM) results show that MWCNTAs grown on the bottom and the central of the quartz tube are different in one experiment. Moreover, the MWCNTAs grown on the central position are more aligned and longer than those on the bottom. A computational fluid dynamics (CFD) model was employed to investigate the gas flow field impact on the MWCNTAs growth. The results show that gas circulations appear after carrier gas and carbon source are injected into the quartz tube. Because of the existence of gas circulations, the gas flow field at the central of the quartz tube is more stable, which is conducive to the growth of MWCNTAs. The CFD simulation results match well with the experimental data. [ABSTRACT FROM AUTHOR]

Conventional therapeutic monoclonal antibodies (mAbs) are invalid for intracellular viruses but by using in situ biomineralization treatment, they can be successfully delivered into cells to inhibit intracellular viral replication. This achievement significantly expands the applications of mAbs and provides a new intracellular strategy to control viral infections. [ABSTRACT FROM AUTHOR]

A space-resolved extreme ultraviolet (EUV) spectrometer working in 60–400 Å range has been developed to observe impurity emission profiles in core and edge plasmas of Large Helical Device (LHD). A flat focus is made for plane surface detector by using a varied line spacing holographic grating with an angle of incidence of 87°. An excellent spectral resolution of 0.22 Å at 200 Å is then obtained after careful adjustment of the optical components. In the profile measurement of the LHD plasmas, the toroidal resolution is important as well as the radial resolution because the magnetic surfaces of LHD quickly change when the observation chord is tilted at a slightly different toroidal location. Horizontal dispersion is therefore selected for the present spectrometer. As a result, the toroidal resolution of 75 mm is achieved at the plasma position. An enough radial resolution of 10 mm is also obtained at spatial-resolution slit width of 0.2 mm. In order to measure the full radial profile of LHD plasmas the spectrometer is placed at a distance of ∼9200 mm away from the plasma center and a backilluminated charge-coupled device with a size of 6.6×26.6 mm2 is set vertical to the horizontal dispersion. Half of the LHD plasma, i.e., ∼50 cm, can be measured along the vertical direction at horizontally elongated plasma cross section. A full vertical profile can be obtained by changing the vertical angle of the EUV spectrometer. As an example the full vertical profile of edge C IV (312.4 Å) emission is presented. A wavelength interval of 35–65 Å can be simultaneously observed, which varies according to the wavelength to be measured. A local emission profile of Fe XX (132.67 Å) is also presented after Abel inversion as a typical example of the core EUV emission. Finally, the EUV spectrometer is absolutely calibrated using EUV bremsstrahlung continuum profile in comparison with absolute values of visible bremsstrahlung continuum profile because the bremsstrahlung continuum can be easily detected in high-density discharges of LHD. [ABSTRACT FROM AUTHOR]

Multi‐walled carbon nanotube arrays could be easily grown on the central position in the quartz tube. SEM images show the well‐aligned carbon nanotube feature. They clearly exhibit the highly ordered array structures and a very good alignment of carbon nanotube arrays with high packing densities. [ABSTRACT FROM AUTHOR]