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Introduction: Entry into the viable but nonculturable (VBNC) state is a survival strategy adopted by bacteria to survive harsh environment. Although VBNC cells still have metabolic activity, they lose the ability to form colonies on nonselective culture media. Thus, conventional bacterial detection methods, such as plate counting, are unable to detect the presence of VBNC cells. When the environmental conditions are appropriate, VBNC cells can initiate resuscitation, posing a great risk to the safety of public health. The study of the VBNC resuscitation mechanism could provide new insights into the prevention and control of VBNC resuscitation. Objectives: Uncovering the molecular mechanism of VBNC cell resuscitation by investigating the role of O-antigen ligase (RfaL) in inhibiting the resuscitation of Escherichia coli O157:H7 in the VBNC state. Methods: RfaL was screened and verified as a resuscitation inhibitor of VBNC Escherichia coli O157:H7 by detecting resuscitation curve and time-lapse microscopy. The mechanism of RfaL impacts VBNC E. coli resuscitation was investigated by detecting the single cell ATP content, metabolomic changes, NAD(H) content and new protein biosynthesis of WT and ΔrfaL at different stage of resuscitation. Results: Mutation of rfaL, which encoded an O-antigen ligase, markedly shortened the resuscitating lag phase. Further studies indicated that ΔrfaL VBNC cells contained higher ATP levels, and ATP consumption during the resuscitating lag phase was highly correlated with resuscitation efficiency. Metabolomic analysis revealed that ATP was utilized to activate the Handler and salvage pathways to synthesize NAD+, balancing redox reactions to recover cell activity and promote cell resuscitation. Conclusion: Our findings revealed a strategy employed by VBNC cells for revival, that is, using residual ATP to primarily recover metabolic activity, driving cells to exit dormancy. The synthesis pathway of lipopolysaccharide (LPS) in rfaL null mutant was inhibited and could supply more ATP to synthesis NAD+ and promote resuscitation.

Traditional unsupervised speech enhancement models often have problems such as non-aggregation of input feature information, which will introduce additional noise during training, thereby reducing the quality of the speech signal. In order to solve the above problems, this paper analyzed the impact of problems such as non-aggregation of input speech feature information on its performance. Moreover, this article introduced a temporal convolutional neural network and proposed a SASEGAN-TCN speech enhancement model, which captured local features information and aggregated global feature information to improve model effect and training stability. The simulation experiment results showed that the model can achieve 2.1636 and 92.78% in perceptual evaluation of speech quality (PESQ) score and short-time objective intelligibility (STOI) on the Valentini dataset, and can accordingly reach 1.8077 and 83.54% on the THCHS30 dataset. In addition, this article used the enhanced speech data for the acoustic model to verify the recognition accuracy. The speech recognition error rate was reduced by 17.4%, which was a significant improvement compared to the baseline model experimental results.

The Leuconostoc citreum SJ-57 strain isolated from the sweet potato starch production showed great potential as a microbiological flocculant, but its underlying flocculation mechanisms are yet unknown. In this study, infrared spectroscopy and thermodynamic analysis were performed to elucidate the short-range and long-range interactions between Leuc. citreum SJ-57 and starch granules, revealing that bacteria cells bond starch granules via metal-bridging ionic bonds. A high repulsive energy barrier of ~8 × 10−18 J must be overcome to initiate the flocculation process. Heat, protease, lipase, lysozyme, dextranase, and guanidine hydrochloride were used to treat the bacterial cell, confirming that its flocculation ability originated from surface proteins, including GW structural domain proteins, DnaK, GroEL, elongation factor Tu, and lysozyme M1. The primary flocculation mechanisms of Leuc. citreum was proposed to provide a deep understanding of microbiological flocculants and a foundation for future industrial applications in starch production.

Starch is a major component of the human diet and has several hierarchies including granule, shell, blocklet, amylose and amylopectin, which can be used as the raw materials in food processing. In order to be applied in a suitable range, this involves the selection of separation methods and the accurate characterization of the structural properties of each starch hierarchy. Therefore, this paper analyzes the separation and characterization methods for each starch hierarchy, introduces their different applications, and thus provides some references for the development and utilization of starch resources.

Unsaturated fatty acids (UFAs) play a fundamental role in maintaining human health and serve as an important raw material for functional foods. However, UFAs are prone to oxidization during processing and storage, leading to deterioration. Microencapsulation of UFAs is an effective processing method to minimize oxidation and enhance its stability. In this paper, the physiological functions of UFAs and their applications in food, medicine, and other fields are summarized. The research progress of microencapsulation technology of UFAs is systematically reviewed, aiming to provide a theoretical basis and rationale for their applications in the food industry. Research has shown that the wall materials widely used were mainly proteins and carbohydrates, whereas their combination can overcome their disadvantages. Spray drying, freeze drying, molecular encapsulation, and coacervation method are most commonly used in the fabrication of microencapsulated UFAs. Using various wall materials and fabrication methods leads to very different encapsulation efficiency, which also greatly impacts the stability of UFAs during processing and storage. Hence, it is still necessary to select appropriate materials and methods according to the properties and functions of the food products. Microencapsulated UFAs exhibited slow-release properties and improved physiological functions. Therefore, it may have broad applications and excellent future development prospects in the food industry.

Point cloud registration from laser scanning data is a technique to establish the mapping relationship between source and target point clouds, which has been widely used in automatic 3D reconstruction, pose estimation, localization, and navigation. While algorithms like Super4PCS and MSSF-4PCS can achieve registration without initial poses, they are relatively slow, less accurate, and require iterations. To address these issues, we propose a 3D point cloud registration algorithm based on interval segmentation and multi-dimensional feature. Firstly, the source and target point clouds are segmented internally and the point cloud curvature is designed to narrow down the search range for the registration between the segmented point clouds. Secondly, the corresponding four-point sets in the segmented areas of the source and target point clouds are determined using affine invariance constraints. Finally, a multi-dimensional feature vector based on curvature features and fast point feature histogram is established to determine the unique corresponding four-point set pairs, and the rigid body transformation matrix is solved accordingly. Our algorithm is tested on publicly available 3D point cloud data models Bunny, Dino, Dragon, and Horse from Stanford University. Results showed that our algorithm improved registration accuracy by 24.39% and registration efficiency by 46.21% compared to the MSSF-4PCS point cloud registration algorithm. Multiple sets of experimental results confirmed the effectiveness of our algorithm. The proposed 3D point cloud registration is proved to be fast with high accuracy, which can be utilized for automatic segmentation, reconstruction, and modelling from Laser Scanning Data.

Objective: Exploring the disinfection effect of high-pressure carbon dioxide (HPCD) on human coronavirus 229E (hCoV-229E). Methods: The human coronavirus 229E (hCoV-229E) was treated by HPCD at different temperatures (10, 25, and 37 ℃) and pressures (6.3 and 10 MPa) for different time (15 and 30 min). Result: Compared with the control groups under the corresponding temperatures, the virus titer in 50 mL tube treated with HPCD at 10 ℃ and 6.3 MPa for 30 min was significantly decreased (P

Abstract Precise localisation and navigation are the two most important tasks for mobile robots. Visual simultaneous localisation and mapping (VSLAM) is useful in localisation systems of mobile robots. The wide‐angle camera has a broad field of vision and more abundant information on images, so it is widely used in mobile robots, including legged robots. However, wide‐angle cameras are more complicated than ordinary cameras in the design of visual localisation systems, and higher requirements and challenges are put forward for VSLAM technologies based on wide‐angle cameras. In order to resolve the problem of distortion in wide‐angle images and improve the accuracy of localisation, a sampling VSLAM based on a wide‐angle camera model for legged mobile robots is proposed. For the predictability of the periodic motion of a legged robot, in the method, the images are sampled periodically, image blocks with clear texture are selected and the image details are enhanced to extract the feature points on the image. Then, the feature points of the blocks are extracted and by using the feature points of the blocks in the images, the feature points on the images are extracted. Finally, the points on the incident light through the normalised plane are selected as the template points; the relationship between the template points and the images is established through the wide‐angle camera model, and the pixel coordinates of the template points in the images and the descriptors are calculated. Moreover, many experiments are conducted on the TUM datasets with a quadruped robot . The experimental results show that the trajectory error and translation error measured by the proposed method are reduced compared with the VINS‐MONO, ORB‐SLAM3 and Periodic SLAM systems.

Starch and polyphenols can interact through predominant non-covalent bonds to form a range of distinctive starch-polyphenol complexes, which exhibit varied physicochemical properties, nutritional characteristics, and bioavailability. This paper mainly reviews the current regulation methods and effect, as well as the regulation mechanism of different food processing methods to the interactions between starch and polyphenol in perspective of thermal, non-thermal and the combined processing methods in recent decades. Different food processing methods turn out to modulate the interactions between starch and polyphenols by changing the multi-scale structure of starch. Thermal processing methods affect starch structure through strong thermal effect, which is beneficial to strengthen the interactions between starch and polyphenols and induce the formation of new crystalline structure. Non-thermal processing methods are considered to have a less obvious effect on starch structure in comparison of thermal processing methods, but could have more precise modifications. And the combined processing methods can further improve efficiency. This review is expected to provide reference for future quality control in food system by appropriate processing technology.

To analyze the quality discrepancies of pod pepper, line pepper and horn pepper , the integrated structural characteristic values ( the seeds content and sarcocarp content), crude fiber, sugar, fat, protein, moisture, ash, carotenoids, capsaicins, and volatile compounds in nine dried pepper varieties were detected in this study, which test samples of pepper varieties included three pod peppers (Neihuang-xinyidai, Huaxi-dangwu pepper and Qiubei pepper), four line peppers (Dafang wrinkly pepper, Shawan line pepper, Shaanxi qin pepper and Gangu line pepper) and two horn peppers (Tuoxian red pepper and Yidu red pepper), respectively. Principal component analysis and cluster analysis were carried out to evaluate the comprehensive quality of dried peppers. The results indicated that the seeds and sarcocarp in whole dried pepper constituted 21%~47% and 52%~79%, respectively. The crude fiber, sugar, fat and protein were 35%~46%, 11%~28%, 13%~19% and 14%~18%, respectively. The reducing sugar was made up 77%~99%. Unsaturated fatty acids represented over 80% among total fatty acids, linoleic acid accounted for 61%~73%. Capsanthin (37~221 mg/100 g) was the dominant in total carotenoids (73~458 mg/100 g), and the contents of capsaicins vary 18~206 mg/100 g. Eleven types of volatile compounds were detected in test samples, and total volatile constituents content was 1.12~7.65 mg/100 g. For principal component analysis, three principal components were extracted, and their cumulative variance contribution rate was up to 85.29%, which reflected mostly the quality characteristics of dried peppers. Nine dried pepper varieties samples were divided into two classes by cluster analysis, the first class includes three pod pepper varieties, the second class inludes six samples of line peppers and horn peppers. The analysis of the integrated structural characteristic values and their correlations with quality indicators revealed that seeds in pod pepper samples were higher, which contained higher fat, crude fiber, and more abundant volatile compounds, the sarcocarp in the samples of line peppers or horn peppers were higher, which contained higher sugar and carotenoids. Meanwhile, the contents of crude fiber and fat were significant positively correlated with seeds content (P

Abstract In this study, composite pear juice was processed by ultra‐high pressure homogenization (UHPH) at four different pressures (50, 100, 150, and 200 MPa) with six different temperatures (4, 20, 30, 40, 60, and 80°C), then microorganism and physicochemical and nutritional properties of the samples were investigated. The counts of total aerobic bacteria (TAB) and yeasts and molds (Y&M) were reduced by 0.89–4.72 log10 CFU/ml and 0.40–3.03 log10 CFU/ml after processing, respectively. There was no significant change on total soluble solid and color, but significant decreases of pH and particle size value were observed, and the antioxidant activity, total phenolic content, viscosity, and suspension stability significantly increased in treated samples. Compared to the untreated samples, polyphenol oxidase (PPO) and peroxidase (POD) activity of UHPH‐treated samples varied between 97%–126% and 81%–165%, respectively, indicating that the PPO and POD activities could be inactivated or activated by UHPH. This study introduced proper temperature combined with UHPH could improve the microbial inactivation and the quality of the compound juice.

To investigate the changes of lipids and volatile flavor components of Chinese braised pork in brown sauce after sterilization processes, quantitative analysis of the whole lipid components of unpasteurized, pasteurized, and ultra-high pressure (UHP) braised pork in the brown sauce was conducted using ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry. A total of 251 different lipids were identified. Partial least squares discriminant analysis and hierarchical clustering analysis were used to successfully distinguish the braised pork samples processed with different sterilization methods. Among them, 24 lipid substances were the key compounds to effectively distinguish the lipids, including 15 types of triglycerides (TG), 8 types of phospholipids, and N-acylethanolamine. According to the relative contents of lipid compounds, the braised meat after UHP sterilization was closer to the control group than the ones pasteurized. Using solid-phase micro-extraction coupled with gas chromatography-mass spectrometry, the types and contents of volatile components in braised pork under different sterilization methods were compared. A total of 31 volatile flavor components were identified, including 4 types of alcohols, 4 types of acids, 4 types of lipids, 7 types of alkanes, 2 types of ketones, and 9 types of aldehydes and furan. Based on these results, it was found that the UHP sterilization could maintain the original flavor and lipid composition of Chinese braised pork in brown sauce, which had great potential in meat processing and Chinese cuisine preparation.

Accurate mathematical modeling of state of charge (SOC) prediction is essential for battery management systems (BMSs) to improve battery utilization efficiency and ensure a good safety performance. The current SOC prediction framework only considers battery-related features but ignores vehicle information. Additionally, in light of the emergence of time-series Transformers (TSTs) that harness the power of multi-head attention, developing a SOC prediction model remains a significant challenge. Therefore, we introduce a new framework that integrates laboratory battery data with mathematical vehicle model features to improve the accuracy of the SOC and propose a prediction model named DLPformer, which can effectively capture variations in the SOC attributed to both trend and seasonal patterns. First, we apply Matlab/Simulink to simulate a mathematical model of electric vehicles and process the generated vehicle data with Spearman correlation analysis to identify the most relevant features, such as the mechanical losses of the electric motor, differential, and aerodynamic drag. Then, we employ a data fusion method to synchronize the heterogeneous datasets with different frequencies to capture the sudden changes in electric vehicles. Subsequently, the fused features are input into our prediction model, DLPformer, which incorporates a linear model for trend prediction and patch-input attention for seasonal component prediction. Finally, in order to effectively evaluate the extrapolation and adaptability of our model, we utilize different driving cycles and heterogeneous battery datasets for training and testing. The experimental results show that our prediction model significantly improves the accuracy and robustness of SOC prediction under the proposed framework, achieving MAE values of 0.18% and 0.10% across distinct driving cycles and battery types.

As a non-thermal technology, high hydrostatic pressure (HHP) has been widely investigated for inactivating microorganisms in food. Few studies have been presented on the pressurization/depressurization rate and mode of microbial inactivation. In this study, effect of pressurization rate and mode on Escherichia coli and Staphylococcus aureus cell damage during HHP treatment was investigated. The results showed that fast pressurization + linear mode (FL) treatment has the best bactericidal effect on E. coli and S. aureus, followed by fast pressurization + stepwise mode (FS) and slow pressurization + stepwise mode (SS) treatments. FL treatment caused more morphological damage to the cell wall, cell membrane, and cytoplasmic components compared with FS and SS treatment detected by SEM and TEM. Additionally, the damage to membrane permeability of them was also enhanced after FL treatment. Therefore, our results indicated that FL treatment could be applied to enhance the bactericidal effect of HHP on bacteria by increasing the damage to cell morphological structure and membrane integrity.

Formal modeling and verification of a concurrent system is an essential means to ensure the security and reliability of the system. However, at present, there is no single formal method that can fully meet the modeling and verification requirements of concurrent systems. In this paper, we propose an integrated formal method that utilizes both event-based method Event-B and state-based formalism LTS to address this problem. We first analyze the difference and connection between Event-B and LTS in building system models and then propose to use the graphical front-end iUML-B of Event-B to obtain a unified representation with LTS so as to take their advantages in the integrated method. Finally, we carry out a case study to demonstrate the practicality of the proposed method. The case study shows that our method effectively models and verifies the various properties of the system, and to a large extent makes up for the shortcomings of a single formal method in the process of system modeling and verification.

Summary: Bacterial spores can preserve cellular dormancy for years, but still hold the remarkable ability to revive and recommence life. This cellular awakening begins with a rapid and irreversible event termed germination; however, the metabolic determinants required for its success have been hardly explored. Here, we show that at the onset of the process of sporulation, the metabolic enzyme RocG catabolizes glutamate, facilitating ATP production in the spore progenitor cell, and subsequently influencing the eventual spore ATP reservoir. Mutants displaying low RocG levels generate low ATP-containing spores that exhibit severe germination deficiency. Importantly, this phenotype could be complemented by expressing RocG at a specific window of time during the initiation of sporulation. Thus, we propose that despite its low abundance in dormant spores, ATP energizes spore germination, and its production, fueled by RocG, is coupled with the initial developmental phase of spore formation.

The COVID-19 pandemic has led to a burgeoning demand for active travel (walking or cycling), which is a healthy, pollution-free, and affordable daily transportation mode. Park green space (PGS), as an open natural landscape, have become a popular destination for active travel trips in metropolitan areas. Pedestrians and cyclists are often at high crash risk when exposed to complicated traffic environments in urban areas. Therefore, this study aims to propose a safety assessment framework for evaluating active travel traffic safety (ATTS) near PGS from the perspective of urban planning and exploring the effect of the point-of-interest (POI) aggregation phenomenon on ATTS. First, links between ATTS and the environment variables were investigated and integrated into the framework using the catastrophe model. Second, the relationship between the POI density and ATTS was investigated using three spatial regression models. Results in the Wuhan Metropolitan Area as a case study have shown that (1) the population density, road density, nighttime brightness, and vegetation situation near PGS have pronounced effects on ATTS; (2) pedestrians near PGS enjoy safer road facilities than cyclists. Active travel traffic near PGS requires more attention than non-park neighborhoods; (3) among four park categories, using active travel to access theme parks is the safest; and (4) SEM has the best fit for POI cluster research. Increases in leisure facility density and residence density may lead to deterioration and improvement in ATTS safety levels near PGSs, respectively. The safety framework can be applied in other regions because the selected environment indicators are common and accessible. The findings offer appropriate traffic planning strategies to improve the safety of active travel users when accessing PGS.

For the better standardization and widespread application of the determination method of carotenoids in both chili peppers and their products, this work reports for the first time the simultaneous determination of five main carotenoids, including capsanthin, zeaxanthin, lutein, β-cryptoxanthin and β-carotene in chili peppers and their products, with optimized extraction and the high-performance liquid chromatography (HPLC) method. All parameters in the methodological evaluation were found to be in good stability, recovery and accuracy compliance with the reference values; the R coefficients for the calibration curves were more than 0.998; and the LODs and LOQs varied from 0.020 to 0.063 and from 0.067 to 0.209 mg/L, respectively. The characterization of five carotenoids in chili peppers and their products passed all the required validation criteria. The method was applied in the determination of carotenoids in nine fresh chili peppers and seven chili pepper products.

Previously, a new copper-zinc SOD (CuZnSOD) isolated from chestnut rose (Rosa roxburghii) with good stability was described. In this study, the biosynthetic approach was used to create recombinant CuZnSOD. RACE PCR was also used to amplify the full-length CuZnSOD gene from chestnut rose, and the ORF segment was expressed in E. coli BL21 and P. pastoris GS115. For characterization, the enzyme was isolated in two steps in E. coli and one step in P. pastoris. The biochemical properties of the two recombinant enzymes were similar, and their optimal reaction pH and temperature were 6.0 and 50°C, respectively. According to molecular dynamics simulation, the CuZnSOD showed high stability from 70 to 90°C, and eight amino acids are important for enzyme thermal stability at high temperatures. This study set the stage for industrial manufacture by filling gaps in the link between conformational changes and the thermal stability of the new CuZnSOD.

Herein, we present a method for the quantitative analysis of broflanilide residues in water, soil, and rice samples from a paddy field in Jiangxi Province, China. The quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was optimized for the extraction and purification of broflanilide residues. Residual broflanilide concentrations in different matrices were then determined by high-performance liquid chromatography (HPLC). The calibration curve of broflanilide showed good linearity in all matrices for concentrations between 0.005 and 1 mg·L−1, with a correlation coefficient greater than 0.99. The matrix effect varied from −69% to −54%, indicating matrix suppression. The average recoveries ranged between 85.82% and 97.46%, with relative standard deviations of 3.29%–8.15%. The limits of detection ranged from 0.16 to 1.67 μg·kg−1, and the limits of quantification were in the range of 0.54 to 5.48 μg·kg−1. Dissipation dynamic tests indicated broflanilide half-lives of 0.46–2.46, 2.09–5.34, and 1.31–3.32 days in soil, water, and rice straw, respectively. Broflanilide was dissipated more rapidly in water than in soil and rice straw. More than 90% of broflanilide residues dissipated within 14 days. The final residues of broflanilide in rice were all below LOQ at harvest.

The viable but non-culturable (VBNC) state, in which bacteria fail to grow on routine culture media but are actually alive, has been widely recognized as a strategy adopted by bacteria to cope with stressful environments. However, little is known regarding the molecular mechanism of VBNC formation. Here, we aimed to elucidate the specific roles of cell division regulatory proteins and the cell growth rate during VBNC Escherichia coli O157:H7 formation. We have previously found that expression of dicC is reduced by 20.08-fold in VBNC E. coli O157:H7 compared to non-VBNC cells. Little is known about DicC except that it, along with DicA, appears to act as a regulator of cell division by regulating expression of the cell division inhibitor DicB. First, our results showed that the VBNC cell number increased in the ΔdicC mutant as well as the DicA-overexpressing strain but decreased in the DicC-overexpressing strain induced by high-pressure carbon dioxide, acid, and H2O2. Furthermore, the growth rates of both the DicA-overexpressing strain and the ΔdicC mutant were higher than that of the control strain, while DicC-overexpressing strain grew significantly more slowly than the vector strain. The level of the dicB gene, regulated by dicA and dicC and inhibiting cell division, was increased in the DicC-overexpressing strain and decreased in the ΔdicC mutant and DicA-overexpressing strain, which was consistent with the growth phenotypes. In addition, the dwarfing cell morphology of the ΔdicC mutant and DicA-overexpressing strain were observed by SEM and TEM. Taken together, our study demonstrates that DicC negatively regulates the formation of the VBNC state, and DicA enhances the ability of cells to enter the VBNC state. Besides, the cell growth rate and dwarfing cell morphology may be correlated with the formation of the VBNC state.

Basic oxygen furnace (BOF) slag was modified by adding 3.5% SiO2 and holding at 1673 K for 0, 5, 40, 90, 240, or 360 min. Kilo-scale modification was also carried out. The growth, stratification, and liberation of P-rich C2S in the modified slag were investigated. The optimum holding time was 240 min, and 90% of C2S grains were above 30 μm in size. The phosphorus content increased with holding time, and after modification, the phosphorus content in C2S was nearly three times higher than that in the original slag (2.23%). Obvious stratification of C2S was observed in the kilo-scale modification. Upper C2S particles with a relatively larger size of 20−110 μm was independent of RO (FeO-MgO-MnO solid solution) and spinel, which is favorable for liberation. Lower C2S was less than 3 μm and was embedded in spinel, which is not conducive to liberation. The content of phosphorus in upper C2S (6.60%) was about twice that of the lower (3.80%). After grinding, most of the upper C2S existed as free particles and as locked particles in the lower. The liberation degree of C2S in the upper increased with grinding time, from 86.02% to 95.92% in the range of 30−300 s, and the optimum grinding time was 180 s. For the lower slag grinding for 300 s, the liberation degree of C2S was 40.07%.

Developing the formal model based on the Event-B design pattern is an excellent method to improve the development efficiency of the embedded control system and improve the reusability of the formal model. However, the instantiation of the Event-B design pattern requires the manual writing of a large number of model codes, which brings a great deal of learning cost and coding burden to the engineering staff. In this paper, we propose a modelling approach for formal development of control systems based on the application of iUML-B state machine patterns to model the four synchronization patterns of the typical control system. Then, we use the instantiation of iUML-B pattern state machine to establish a typical multilevel control system's Event-B model. The simulation results show that the event trace of the model obtained using our method is the same as that of the corresponding model obtained using the traditional Event-B design pattern. Compared with the traditional Event-B design pattern method, our method can greatly reduce the manual coding burden in the modelling process. The system model expressed using the iUML-B pattern state machine can be easily mapped to the labelled transition system so as to verify the behavioural properties of the model.

The inactivation effects of high pressure CO2 + nisin (simultaneous treatment of HPCD and nisin, HPCD + nisin), HPCD→nisin (HPCD was followed by nisin), and nisin→HPCD (nisin was followed by HPCD) treatments on Bacillus subtilis spores in aqueous solutions were compared. The spores were treated by HPCD at 6.5 or 20 MPa, 84-86ºC and 0-30 min, and the concentration of nisin was 0.02%. Treated spores were examined for the viability, the permeability of inner membrane (IM) using flow cytometry method (FCM) and pyridine-2, 6-dicarboxylic acid (DPA) release, and structural damage by transmission electron microscopy (TEM). A synergistic effect of HPCD + nisin treatment on inactivation of the spores was found, and the inactivation efficiency of the spores was HPCD + nisin > HPCD→nisin or nisin→HPCD. Moreover, HPCD + nisin caused higher IM permeability and DPA release of the spores than HPCD. A possible action mode of nisin-enhanced inactivation of the spores was suggested as that HPCD firstly damaged the coat and cortex of spores, and nisin penetrated into and acted on the inner membrane (IM) of spores, which increased the damage to the IM of spores, and resulted in higher inactivation of the spores.

Silicon nanowires (SiNWs) embedded in Ag nano-hole arrays with broadband light absorption is proposed in this paper. Finite Difference Time Domain (FDTD) simulations were utilized to obtain absorptivity and band diagrams for both SiNWs and SiNWs embedded in Ag nano-hole arrays. A direct relationship between waveguide modes and extraordinary absorptivity is established qualitatively, which helps to optimal design the structure parameters to achieve broadband absorptivity. After introducing Ag nano-hole arrays at the rear side of SiNWs, the band modes are extended into leaky regions and light energy can be fully absorbed, resulting in high absorptivity at long wavelength. Severe reflection is also suppressed by light trapping capability of SiNWs at short wavelength. Over 70% average absorptivity from 400 nm to 1100 nm is realized finally. This kinds of design give promising route for high efficiency solar cells and optical absorbers.

The objective of this study was to investigate the inactivation mechanism of Bacillus subtilis spores by high pressure CO2 (HPCD) processing. The spores of B. subtilis were subjected to heat at 0.1 MPa or HPCD at 6.5-20 MPa, and 64-86ºC for 0-120 min. The germination, the permeability of inner membrane (IM) and cortex, the release of pyridine-2, 6-dicarboxylic acid (DPA), and changes in the morphological and internal structures of spores were investigated. The HPCD-treated spores did not lose heat resistance and their DPA release was lower than the inactivation, suggesting that spores did not germinate during HPCD. The flow cytometry analysis suggested that the permeability of the IM and cortex of HPCD-treated spores was increased. Furthermore, the DPA of the HPCD-treated spores were released in parallel with their inactivation and the fluorescence photomicrographs showed that these treated spores were stained by propidium iodide (PI), ensuring that the permeability of IM of spores was increased by HPCD. The scanning electron microscopy (SEM) photomicrographs showed that spores were crushed into debris or exhibited a hollowness on the surface, and the transmission electron microscopy (TEM) photomicrographs exhibited an enlarged core, ruptured and indistinguishable IM and a loss of core materials in the HPCD-treated spores, indicating that HPCD damaged the structures of the spores. These findings suggested that HPCD inactivated B. subtilis spores by directly damaging the structure of the spores, rather than inducing germination of the spores.

Fermentation is a traditional method utilized for vegetable preservation, with microorganisms playing a crucial role in the process. Nowadays, traditional spontaneous fermentation methods are widely employed, which excessively depend on the microorganisms attached to the surface of raw materials, resulting in great difficulties in ideal control over the fermentation process. To achieve standardized production and improve product quality, it is essential to promote inoculated fermentation. In this way, starter cultures can dominate the fermentation processes successfully. Unfortunately, inoculated fermentation has not been thoroughly studied and applied. Therefore, this paper provides a systematic review of the potential upgrading strategy of vegetable fermentation technology. First, we disclose the microbial community structures and succession rules in some typical spontaneously fermented vegetables to comprehend the microbial fermentation processes well. Then, internal and external factors affecting microorganisms are explored to provide references for the selection of fermented materials and conditions. Besides, we widely summarize the potential starter candidates with various characteristics isolated from spontaneously fermented products. Subsequently, we exhibited the inoculated fermentation strategies with those isolations. To optimize the product quality, not only lactic acid bacteria that lead the fermentation, but also yeasts that contribute to aroma formation should be combined for inoculation. The inoculation order of the starter cultures also affects the microbial fermentation. It is equally important to choose a proper processing method to guarantee the activity and convenience of starter cultures. Only in this way can we achieve the transition from traditional spontaneous fermentation to modern inoculated fermentation. [ABSTRACT FROM AUTHOR]