A novel core-shell up-conversion nanoparticles immunochromatographic assay for the detection of deoxynivalenol in cereals.

Deoxynivalenol (DON) toxin is a type B group of trichothecene mycotoxins mainly originating from specific Fusarium fungi, seriously harming human and livestock health. Herein, a novel core-shell up-conversion nanoparticles immunochromatographic assay (CS-UCNPs-ICA) was developed for deoxynivalenol based on the competitive reaction principle. By exploiting the fluorescence intensity of the T and C lines of CS-UCNPs-ICA, the concentrations of DON were obtained sensitively and precisely under optimized conditions in 5 min with a detection limit of 0.1 ng/mL. The CS-UCNPs-ICA strips only specifically detect DON and its derivatives (3-Ac-DON and 15-Ac-DON), with no cross-reaction with other mycotoxins. The low CV values illustrated a modest intra- and inter-assay variation, confirming the superior precision of this method. In the spiked experiment, the mean recoveries of corn and wheat ranged from 94.74% to 100.90% and 96.21%-104.81%, respectively. Furthermore, the approach generated results that were in good agreement with data from HPLC and ELISA analyses of naturally contaminated feed and cereals, confirming that the significant advantages of proposed strips were their high practicality, rapidness, and simplicity. Therefore, the CS-UCNPs-ICA strips platform serves as a promising candidate for developing new approaches for rapid testing or high throughput screening from DON in food products.

Mechanism Exploration of the Effect of Polyamines on the Polishing Rate of Silicon Chemical Mechanical Polishing: A Study Combining Simulations and Experiments.

Polyamines have become important chemical components used in several integrated circuit manufacturing processes, such as etching, chemical mechanical polishing (CMP), and cleaning. Recently, researchers pointed out that polyamines can be excellent enhancers in promoting the material removal rate (MRR) of Si CMP, but the interaction mechanism between the polyamines and the silicon surface has not been clarified. Here, the micro-interaction mechanisms of polyamines, including ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and pentaethylenehexamine (PEHA), with the Si(1, 0, 0) surface were investigated through molecular dynamics (MD) simulations using the ReaxFF reactive force field. Polyamines can adsorb onto the Si(1, 0, 0) surface, and the adsorption rate first accelerates and then tends to stabilize with the increase in the quantity of -CH2CH2NH-. The close connection between the adsorption properties of polyamines and the polishing rate has been confirmed by CMP experiments on silicon wafers. A comprehensive bond analysis indicates that the adsorption of polyamines can stretch surface Si-Si bonds, which facilitates subsequent material removal by abrasive mechanical wear. This work reveals the adsorption mechanism of polyamines onto the silicon substrate and the understanding of the MRR enhancement in silicon CMP, which provides guidance for the design of CMP slurry.

In-situ Construction of Poly(tetraisopentyl acrylate) based Gel Polymer Electrolytes with Lix La2-x TiO3 for High Energy Density Lithium-Metal Batteries.

As promising alternatives to liquid electrolytes, polymer electrolytes attract much research interest recently, but their widespread use is limited by the low ionic conductivity. In this study, we use electrostatic spinning to introduce particles of an ionic conductor into polyacrylonitrile (PAN) fibers to prepare a porous membrane as the host of gel polymer electrolytes (GPEs). The relevant in-situ produced GPE performs a high ionic conductivity of 6.0×10-3  S cm-1 , and a high lithium transfer number (tLi + ) of 0.85 at 30 °C, respectively. A symmetrical Li cell with this GPE can cycle stably for 550 h at a current density of 0.5 mA cm-2 . While the capacity retention of the NCM|GPE|Li cell is 79.84 % after 500 cycles at 2 C. Even with an increased cut-off voltage of 4.5 V, the 1st coulomb efficiency reaches 91.58 % with a specific discharge capacity of 213.4 mAh g-1 . This study provides a viable route for the practical application of high energy density lithium metal batteries.

DFT Exploration of Metal Ion-Ligand Binding: Toward Rational Design of Chelating Agent in Semiconductor Manufacturing.

Chelating agents are commonly employed in microelectronic processes to prevent metal ion contamination. The ligand fragments of a chelating agent largely determine its binding strength to metal ions. Identification of ligands with suitable characteristics will facilitate the design of chelating agents to enhance the capture and removal of metal ions from the substrate in microelectronic processes. This study employed quantum chemical calculations to simulate the binding process between eleven ligands and the hydrated forms of Ni2+, Cu2+, Al3+, and Fe3+ ions. The binding strength between the metal ions and ligands was quantified using binding energy and binding enthalpy. Additionally, we explored the binding interaction mechanisms and explained the differences in binding abilities of the eleven ligands using frontier molecular orbitals, nucleophilic indexes, electrostatic potentials, and energy decomposition calculations based on molecular force fields. Based on our computational results, promising chelating agent structures are proposed, aiming to guide the design of new chelating agents to address metal ion contamination issues in integrated circuit processes.

Is there any difference in organizational commitment between general hospitals and specialized hospitals? Empirical evidence from public hospitals in Beijing, China.

OBJECTIVE: The purpose of the study on the one hand is to see different hospital organization commitment have difference, including the overall score and various dimensions, on the other hand, due to the different hospital type, its function orientation is different, the factors of the doctor organization commitment may also exist differences, so the study of another purpose is to determine for different types of hospital doctor organization commitment the focus and key groups, provide reference for the doctor incentive strategy. METHODS: A total of 292 doctors in four large public hospitals in Beijing were investigated. Physicians' perceived organizational commitment was investigated using self-made electronic questionnaires. Data were analyzed by factor analysis, descriptive statistics, t-test, ANOVA, and multiple linear regression. RESULTS: In the large public hospital doctor perception of the hospital commitment status, Specialized hospitals had higher overall commitment behavior scores, it is 3.47 ± 0.86; General hospital commitment behavior scored low at 3.39 ± 0.91. In the regression results, department category, working years, administrative position, and entry mode are the influencing factors of the organizational commitment of doctors in general hospitals, while in specialized hospitals, in addition to whether to hold an administrative position, entry mode, and working hours, the influencing factors also include gender, professional title and overseas learning background. CONCLUSION: There are differences in the perceived organizational commitment by doctors in different types of public hospitals, and different factors influencing their organizational commitment.Hospital type directly influences physicians' organizational commitment and plays a moderating role in influencing other factors. A possible solution is general hospital specialization, encouraging general hospitals to develop the dominant discipline. These findings can help healthcare service hospital executives or government policymakers understand the impact of hospital specialization strategies and develop more efficient medical staff incentive systems.

Effect of Aspergillus flavus contamination on the fungal community succession, mycotoxin production and storage quality of maize kernels at various temperatures.

Aspergillus flavus, a notorious saprobe and opportunistic plant pathogen, alters mycotoxin contamination and biochemical components in maize kernels during processing and storage, thereby reducing the possibilities of maize end use and compromising food safety. This study explored changes in mycotoxin production, fungal community succession and biochemical components in maize kernels stored at 20, 25 and 30 °C, exposed to A. flavus. Results showed that aflatoxin B1 concentration increased over time, reaching 4.88 µg/kg at 20 °C, 167.23 µg/kg at 25 °C and 349.64 µg/kg at 30 °C after 15 days of storage, whereas the zearalenone production was characterized by an increase followed by a decrease. Correspondingly, the number of molds gradually increased and reached a stable stage after 10 days. High-throughput sequencing of the internal transcribed spacer (ITS) revealed that Eurotium dominated the fungal communities, with A. flavus reaching maximum abundance in maize kernels stored at 30 °C for 15 days. Correlation analysis indicated that the relative abundance of A. flavus was significantly negatively correlated with the content of zein and moisture (P < 0.05). Moreover, the wet milling process of maize effectively eliminated the concentration of aflatoxin B1 and zearalenone from the starch. Pasting temperature and setback value of starch decreased while peak viscosity, final viscosity and breakdown value increased with storage. These findings indicate that interactions between the epiphytic fungal community and A. flavus at elevated storage temperatures aggravate both maize quality deterioration and mycotoxin contamination. Furthermore, they have a discernible impact on the pasting properties of starch. This insight informs strategies to control fungal infections during maize processing and storage.

Quantifying Health Policy Uncertainty in China Using Newspapers: Text Mining Study.

BACKGROUND: From the severe acute respiratory syndrome (SARS) outbreak in 2003 to the COVID-19 pandemic in 2019, a series of health measures and policies have been introduced from the central to the local level in China. However, no study has constructed an uncertainty index that can reflect the volatility, risk, and policy characteristics of the health environment. OBJECTIVE: We used text mining analysis on mainstream newspapers to quantify the volume of reports about health policy and the total number of news articles and to construct a series of indexes that could reflect the uncertainty of health policy in China. METHODS: Using the Wisenews database, 11 of the most influential newspapers in mainland China were selected to obtain the sample articles. The health policy uncertainty (HPU) index for each month from 2003 to 2022 was constructed by searching articles containing the specified keywords and calculating their frequency. Robustness tests were conducted through correlation analysis. The HPU index was plotted using STATA (version 16.0), and a comparative analysis of the China and US HPU indexes was then performed. RESULTS: We retrieved 6482 sample articles from 7.49 million news articles in 11 newspapers. The China HPU index was constructed, and the robustness test showed a correlation coefficient greater than 0.74, which indicates good robustness. Key health events can cause index fluctuations. At the beginning of COVID-19 (May 2020), the HPU index climbed to 502.0. In December 2022, China's HPU index reached its highest value of 613.8 after the release of the "New Ten Rules" pandemic prevention and control policy. There were significant differences in HPU index fluctuations between China and the United States during SARS and COVID-19, as well as during the Affordable Care Act period. CONCLUSIONS: National health policy is a guide for health development, and uncertainty in health policy can affect not only the implementation of policy by managers but also the health-seeking behavior of the people. Here, we conclude that changes in critical health policies, major national or international events, and infectious diseases with widespread impact can create significant uncertainty in China's health policies. The uncertainty of health policies in China and the United States is quite different due to different political systems and news environments. What is the same is that COVID-19 has brought great policy volatility to both countries. To the best of our knowledge, our work is the first systematic text mining study of HPU in China.

How Does Fiscal Decentralization Affect Health Outcomes? Evidence from China.

Background: The impact of fiscal decentralization on health outcomes still has not reached a consensus, and studies conducted in the context of the new round of fiscal and taxation system reform are even less available. China's fiscal decentralization system has its own special characteristics, so it is necessary to analyze the impact of fiscal decentralization on health outcomes before and after the new round of fiscal and taxation system reform in China. Methods: Panel data from 2007 to 2019 were obtained through China's Health Statistics Yearbook and China's Statistical Yearbook. The effects of fiscal decentralization on health outcomes before and after the reform are explored separately by SYS-GMM, which introduce a dynamical model with a lag period of the explained variables. The Hansen test is used to determine excessive identification. The AR(2) is used to determine whether the residual term of the differential equation has a second-order serial correlation. Results: Fiscal decentralization consistently had a negative impact on health outcomes, yet government health expenditures did not mediate the impact of fiscal decentralization on health outcomes. Fiscal decentralization had a positive effect on per capita government health expenditure before the new reforms, yet had a negative effect on the percentage of government health expenditures, both before and after the new reform. Conclusion: China's fiscal decentralization has caused local governments to pay insufficient attention to the construction of people's livelihoods, and the problem of insufficient government investment in health has not been improved. The new round of fiscal and taxation system reform has not reversed this situation either. It is recommended to adjust the incentive system for local officials, include medical and health in the evaluation indicators of local governments, optimize the structure of government expenditure, and improve the efficiency of the use of government health expenditure.

Influencing factors of low vision 2 years after vitrectomy for proliferative diabetic retinopathy: an observational study.

BACKGROUND: Proliferative diabetic retinopathy (PDR) can seriously affect the vision and quality of life of patients. The present study aimed to evaluate the clinical effect of vitrectomy for PDR by observing visual recovery and postoperative complications and to explore the factors influencing low vision. METHODS: This was a case series observational study. Consecutive eyes of patients with PDR who underwent 23G vitrectomy in our hospital within one year (2019.11-2020.11) were collected and followed up for more than 2 years. Patients' visual acuity, surgical complications and management were collected before the operation and during the follow-up. Decimal visual acuity was recorded and converted to the logarithm of the minimal angle of resolution (logMAR) for statistical analysis. Excel was used to establish a database, and SPSS 22.0 statistical software was used for data analysis. RESULTS: A total of 127 patients and 174 eyes were included in the study. The mean age was 57.8 years. The best corrected visual acuity (BCVA) was < 0.3 in 89.7% of eyes before surgery and ≥ 0.3 in 48.3% of eyes after surgery. Among 174 eyes, visual acuity improved in 83.3%. There was no change in 8.6% of eyes, while 8.1% of eyes had decreased visual acuity after surgery. The average logMAR visual acuity was 1.5 ± 0.7 before surgery and 0.7 ± 0.6 after surgery, indicating significant improvement (p < 0.05). Logistic regression analysis showed that intraoperative silicone oil filling and postoperative complication were significant risk factors for postoperative low vision, while preoperative pseudophakic lens and postoperative intra vitreal injection of anti-VEGF were protective factors for vision recovery (p < 0.05). The incidence of postoperative complications was 15.5%, top three of which were vitreous haemorrhage, neovascular glaucoma and traction retinal detachment. CONCLUSION: Vitrectomy is safe and effective in the treatment of PDR with few complication. Postoperative intra vitreal injection of anti-VEGF is a protective factor for vision recovery. TRIAL REGISTRATION: The trial registration number is ChiCRT2100051628, and the date of registration was September 28, 2021.

Synergistic effect of electrolyzed water generated by sodium chloride combined with dimethyl dicarbonate for inactivation of Listeria monocytogenes on lettuce.

BACKGROUND: Electrolyzed water (EW) is recognized as an effective way to control and reduce pathogens in vegetables. However, the disinfection efficacy of EW alone is limited. In this work, the bactericidal activity and biofilm removal capability of EW, generated by adding NaCl to a portable EW generator, were investigated with special reference to Listeria monocytogenes. Furthermore, the impact of EW in combination with dimethyl dicarbonate (DMDC) in reducing the microbial load and improving the overall quality of lettuce during refrigerated storage was evaluated. RESULTS: EW with 0.3% NaCl (SEW) had the highest bactericidal activity against L. monocytogenes. The pathogen treated with SEW exhibited lower superoxide dismutase activity and more leakage of proteins and nucleic acids than in the case of EW. Furthermore, the use of SEW resulted in changes in the cell permeability and morphology of L. monocytogenes. A decrease in adhesion and collapse of the biofilm architecture were also observed, indicating that SEW was more effective for inactivating L. monocytogenes cells compared to EW. For untreated lettuce, the populations of the total plate count and inoculated L. monocytogenes decreased by 2.47 and 2.35 log CFU g-1 , respectively, after the combined SEW/DMDC treatment for 3 min. The use of SEW alone or combined with DMDC did not negatively impact the lettuce color values, titratable acid, ascorbic acid and soluble solids compared to the control group. CONCLUSION: SEW in combination with DMDC can be used as a novel and potentially effective disinfection strategy for ensuring the safety of vegetable consumption. © 2023 Society of Chemical Industry.

A novel dual-channel immunochromatographic strip using up-conversion nanoparticles for simultaneous detection of AFB1 and ZEN in maize.

Due to universal contamination and synergistic toxicity of multiple mycotoxins in foodstuff, reliable and high-throughput detection methods for multiple mycotoxins are urgently needed in corn products. In this study, a novel dual-channel immunochromatographic assay (ICA) based on improved up-conversion nanoparticles (IUCNPs) was developed for rapidly detecting aflatoxin B1 (AFB1) and zearalenone (ZEN). The synthesized IUCNPs doped by 30% Lu3+ showed a larger size, more regular structure, and brighter fluorescence intensity than conventional UCNPs. The limits of detection (LODs) of single-channel ICA test strips for AFB1 and ZEN detection were 0.01 and 0.1 ng/mL, respectively. After the optimization, the dual-channel ICA of AFB1 and ZEN in 10 min was conducted, resulting in low detection limits of 0.025 and 0.1 ng/mL, respectively. Moreover, the built assay was revealed to be highly specific for six other food-contaminated mycotoxins, and exhibited excellent accuracy, with corresponding R2 of 0.9931 and 0.9982 in calibration curves, respectively. Long-term storage experiments indicated that the dual-channel test strips had superior stability and precision. The LODs of AFB1 and ZEN in spiked maize were 0.025 and 0.25 µg/kg, demonstrating great sensitivity and matrix tolerance. Furthermore, the IUNCP-ICA was validated by high-performance liquid chromatography (HPLC) analyses, and a satisfactory consistency was obtained in 15 natural maize samples. Thus, the IUCNPs-ICA proposed in this work realized rapid and sensitive detection of AFB1 and ZEN, providing broad application potential in on-site screening for multiple mycotoxins in agricultural products.

Slack resources and individual performance of clinicians: the mediating role of job satisfaction and empirical evidence from public hospitals in Beijing, China.

BACKGROUND: Clinicians in Chinese public hospitals face a complex and severe clinical practice environment, and the individual performance of clinicians is key to improving the output of the healthcare industry. This study aims to explore the mechanism of slack resources in improving individual performance of clinicians and the role of job satisfaction in this process, while the study framework is based on the widely applied Job-Demands Resources theory. METHODS: Based on the study framework composed of slack resources, individual performance, and job satisfaction, hypotheses have been put forward, and questionnaires have been distributed to representative clinicians in tertiary public hospitals. Finally, 318 valid data collected from clinicians have been obtained. To verify the hypotheses, multiple linear regression models have been established to explore the relationship between variables, and the three-stage regression models have been used to verify the presence of mediating role. RESULTS: All four hypotheses proposed in this study have been proved to be held. Clinicians' job satisfaction has played a mediating role in the impact of slack resources and its three dimensions on individual performance. Among them, there has been a complete mediating role for staff slack, while time and space dimensions have played a partial mediating role in the impact of slack resources on individual performance. CONCLUSIONS: In public hospitals in environments where behavior is subject to significant government interference, it is necessary and feasible to retain appropriate slack resources to improve individual performance. From the perspective of resources management in hospitals, it is necessary for public hospitals to implement a strategy of reserving an appropriate portion of time, staff and space in order to have the conditions to improve clinicians' satisfaction. The existence of slack resources in public hospitals can improve the job satisfaction of clinicians, and then improve the individual performance through the process.

Impact of slack resources on healthcare costs in tertiary and secondary hospitals: a panel data study of public hospitals in Beijing from 2015 to 2019.

OBJECTIVE: This study aims to explore the relationship between slack resources and cost consumption index in tertiary and secondary hospitals and to provide targeted healthcare resource utilisation recommendations for tertiary and secondary hospital managers. DESIGN: This is a panel data study of 51 public hospitals in Beijing from 2015 to 2019. SETTING: Tertiary and secondary public hospitals in Beijing. Data envelope analysis was used to calculate the slack resources. Regression models were used to explore the relationship between slack resources and healthcare costs. PARTICIPANTS: A total of 255 observations were collected from 33 tertiary hospitals and 18 secondary hospitals. OUTCOME MEASURES: Slack resources and healthcare costs in tertiary and secondary public hospitals in Beijing from 2015 to 2019. Linear or curve relationship between slack resources and healthcare costs in tertiary and secondary hospitals. RESULTS: The cost of healthcare in tertiary hospitals has always been higher than in secondary hospitals, and the slack resources in secondary hospitals have always been worse than in tertiary hospitals. For tertiary hospitals, the cubic coefficient of slack resources is significant (ß=-12.914, p<0.01) and the R2 of cubic regression is increased compared with linear and quadratic regression models, so there is a transposed S-shaped relationship between slack resources and cost consumption index. For secondary hospitals, only the first-order coefficient of slack resources in the linear regression was significant (ß=0.179, p<0.05), so slack resources in secondary hospitals were positively related to the cost consumption index. CONCLUSIONS: This study shows that slack resources' impact on healthcare costs differs in tertiary and secondary public hospitals. For tertiary hospitals, slack should be kept within a reasonable range to control excessive growth in healthcare costs. In secondary hospitals, keeping too many slack resources is not ideal, so managers should adopt strategies to improve competitiveness and service transformation.

Relationship Between Psychological Contract Violation and Physicians' Destructive and Constructive Behaviors in Tertiary Public Hospitals: An Empirical Evidence in Beijing.

Background: In China, physicians have long faced long working hours, high stress levels, and tensions between physicians and patients, which can lead to negative behaviors. Understanding physicians' expectations and requirements of the hospital and increasing satisfaction with their psychological contract can help improve physician motivation and stabilize the hospital team. Aim: The study aims to analyze the relationship between physicians' psychological contract violations and different behavioral choices, encourage hospitals to conclude a balanced psychological contract with physicians, and provide governance and intervention strategies for hospital human resource management. Methods: Stratified cluster sampling was used to select 321 physicians from four public hospitals in Beijing for questionnaire surveys. Descriptive statistical analysis, t-test, ANOVA, correlation analysis, and regression models were performed using Stata 15.0 and SPSS 26.0 to analyze the relationship between psychological contract violations, physicians' EVLN behaviors and organizational justice. Results: Psychological contract violation had a positive effect on exit behavior and neglect behavior, and a negative effect on voice behavior and loyalty behavior. Organizational justice plays a mediating role between psychological contract violation and physicians' exit, voice and loyalty behaviors. Conclusion: Psychological contract violation can drive negative behavior among physicians, and organizational justice can play a mediating role in this. Public hospitals should establish a healthy psychological contract with physicians and place a premium on organizational justice to promote constructive behaviors and prevent destructive behaviors. This study constructs a more complete theoretical framework to explain physicians' behavior, and further dynamic tracking investigations are necessary because the evolution of physicians' behavior is a dynamic and long-term process.

Extracellular matrix affects mature biofilm and stress resistance of psychrotrophic spoilage Pseudomonas at cold temperature.

Psychrotrophic Pseudomonas as the dominant spoilage bacteria, have biofilm forming ability, increasing persistence and contamination in the chilled food. Biofilm formation of spoilage Pseudomonas at cold temperature was documented, however, role of extracellular matrix in mature biofilm and stress resistance of psychrotrophic Pseudomonas are much less abundant. The aim of this study was to investigate the biofilm forming characteristics of three spoilers P. fluorescens PF07, P. lundensis PL28, and P. psychrophile PP26 at 25 °C, 15 °C and 4 °C, and to explore their stress resistance to chemical and thermal treatments of mature biofilms. The results showed that biofilm biomass of three Pseudomonas at 4 °C was significantly higher than that at 15 °C and 25 °C. The secretion of extracellular polymeric substances (EPS) greatly increased in those Pseudomonas under low temperature, of which extracellular protein constituted about 71.03%-77.44%. Compared to 25 °C, the mature biofilms were observed to more aggregation and thicker spatial structure at 4 °C ranging from 42.7 to 54.6 µm, in contrast to 25.0-29.8 µm at 25 °C, especially strain PF07. These Pseudomonas biofilms switched into moderate hydrophobicity, and their swarming and swimming were significantly inhibited at low temperature. Furthermore, the resistance to NaClO and heating at 65 °C apparently enhanced for mature biofilm formed at 4 °C, indicating the difference in EPS matrix production influenced the stress resistance of biofilm. In addition, three strains contained alg and psl operons for exopolysaccharide biosynthesis, and biofilm related genes of algK, pslA, rpoS, and luxR were significantly up-regulated, while flgA gene was down-regulated at 4 °C compared to 25 °C, consistent with the above phenotype changes. Thus, the dramatic increase of mature biofilm and their stress resistance in psychrotrophic Pseudomonas were associated with large secretion and protection of extracellular matrix under low temperature, which provide a theoretical basis for subsequent biofilm control during cold chain.

Design of Miniaturized Wideband Beam Deflection Conformal Array Antenna.

Antenna beam deflection, along with miniaturization and wideband of the antenna is in demand for practical applications. In this paper, a cylindrical conformal array antenna with a small-tilt forward beam was designed. The microstrip antenna unit was loaded with the artificial electromagnetic structure, which reduced the size of the antenna unit. As a result, the center spacing of the array elements can be shortened with the same array element spacing. The beam deflection angle can be increased in this way without increasing the coupling effect between the parts. Changing the number of line array elements and the number of line arrays can regulate the beam width of E-field and H-field, respectively. The bandwidth of the antenna can be significantly extended by slotting the ground plane. This work implemented a cylindrical conformal array of the antenna's forward beam with a small dip angle using a cylindrical carrier as an example. The measurement results showed that the angle between the main beam and the carrier axis of the conformal antenna was less than 30°, the bandwidth was more than 30%, and the antenna volume decreased by 40.4%.

An improved up-conversion nanoparticles-based immunochromatographic assay for rapid detection of zearalenone in cereals.

A novel improved up-conversion nanoparticles-based immunochromatographic assay (IUCNPs-ICA) was developed for the detection of zearalenone (ZEN). Lu3+-doped UCNPs were synthesized using the solvothermal method, and the UCNPs doped with 30 % Lu3+ displayed optimal optical properties. The IUCNPs-ICA was subsequently developed for the detection of ZEN in cereals under optimized conditions. The detection time and limit of detection (LOD) were 10 min and 0.1 µg/L, respectively. Moreover, a good linear relationship was observed from 0 to 100 µg/L ZEN (r2 = 0.9946) and high specificity for other mycotoxins. LODs in spiked maize and wheat reached 0.16 µg/kg, and recovery rates were 82.11-100.76 % and 79.64-98.51 %. There was good consistency between the results of IUCNPs-ICA, colloidal gold-ICA, and high-performance liquid chromatography (HPLC) in the detection of natural cereal samples. The collective results support the utility of IUCNPs-ICA as a reliable on-site screening method for ZEN residue analysis in various cereals.

Transcriptomics reveal the antibiofilm mechanism of NaCl combined with citral against Vibrio parahaemolyticus.

Vibrio parahaemolyticus (VP) as a prominent foodborne pathogen in seafood generally adheres to various surfaces and forms biofilms in the processing of aquatic products. The study aimed to elucidate the inhibitory efficacy and potential mechanism of salinity (NaCl) or it combined with citral against the biofilm formation of VP. Three VP strains formed the most biofilm at 1.0% NaCl, and their biofilms gradually declined with the increase of NaCl concentration. Compared with 1% NaCl, applying 3% and 5% NaCl or NaCl in combination with citral at 10-40 µg/mL significantly reduced biofilm biomass, cellular activity, and viable cells, as well as extracellular polymeric substances (EPS) and cell surface hydrophobicity. Sparser and thinner VP biofilm with large dead cells were observed under the combined treatment, in contrast to the dense architectures of biofilm formed at 1% NaCl. Although VP exhibited the strongest swimming and swarming ability at 3% NaCl, the two motilities were both significantly reduced by citral for all three salinities. Transcriptomic profiling revealed that, compared with 1% NaCl (Con), the two treatments consisting of 3% NaCl (Sal3) and it combined with 40 µg/mL citral (Com) drastically altered gene expression patterns in VP biofilm cells, resulting in 1196 and 1304 differentially expressed genes, respectively. The treatment of Com group altered the transcription of various genes related to chemotaxis, flagellar assembly, EPS synthesis, LuxS and CqsA-mediated quorum sensing, and c-di-GMP, which might interfere with biofilm development of VP. Our findings provided novel insights into the combined regulatory mechanism of high salinity and citral for antibiofilm formation in VP. KEY POINTS: • High salinity enhanced the antibiofilm efficacy of citral against Vibrio parahaemolyticus. • Combined treatment downregulated the expression of exopolysaccharide synthesis genes. • A total of 3% NaCl and combined treatments interfered with signaling pathways of QS and c-di-GMP.

Dynamic changes of quality and flavor characterization of Zhejiang rosy vinegar during fermentation and aging based on untargeted metabolomics.

Zhejiang Rosy Vinegar (ZRV) is a traditional condiment in Southeast China. This study aimed to track the physicochemical, microbiological, sensory changes, and metabolomic profiles of ZRV during fermentation and aging. The increase of acidity and decrease of reducing sugar were associated with the dominant growth of Lactobacillus and Acetobacter. The total 35 volatile compounds were identified in ZRV, mainly containing alcohols, esters, acids, aldehydes, ketones acids, phenols and nitrogen-containing. Compared to phenethyl acetate with sweet aroma in fresh vinegar, the compound with high odor activity values was isoamyl acetate with fruity aromas in aged vinegar. Furthermore, 1309 types of non-volatile components were identified, and histidine metabolism and arginine biosynthesis were revealed as main pathways during fermenting and aging. Concurrently, various bioactive substances in ZRV were identified. This study enriched the knowledge on the components and flavor of ZRV, and assist to improve the production quality of vinegar.

How slack resource affects hospital financial performance: The evidence from public hospitals in Beijing.

Background: Beijing is a city with high concentration and congestion of quality medical resources in China. While moderate slack seems to be beneficial to the improvement of medical quality. The actual relationship between hospital slack resources and their performance deserves further exploration. The study aims to analyze the slack resources of public hospitals in Beijing and investigate the relationship between slack and hospital financial performance. Finding a reasonable range of slack to optimize resource allocation. Methods: The panel data of 22 public hospitals in Beijing from 2005 to 2011 were selected as the sample, and the DEA model was applied to measure the main variable using DEAP 2.1. Descriptive statistical analysis was performed using Excel and STATA 15. Pearson correlation coefficient analysis and variance inflation factor test were performed for each variable to avoid multicollinearity. The HAUSMAN test was used to determine the appropriate panel regression model, and then to analyze the influence relationship between the variables. Results: From 2005 to 2011, hospital slack resource transitioned from high to low. The slack measured by the DEA model has an inverted U-shaped relationship with financial performance, with ROA increasing from 4.088 to 8.083 when slack increases from 0 to about 0.378, and then showing a decreasing trend; slack measured by financial indicators has a transposed S-shaped relationship with financial performance, with ROA increasing when slack increase from 3.772 to 5.933. Conclusions: The slack resources of Beijing public hospitals decreased year by year from 2005 to 2011. Moderate slack resources are conducive to the improvement of healthcare quality, but when slack resources increase to a certain level, it will have a negative impact on healthcare quality. Therefore, hospital managers should control the slack within a moderate range according to the hospital operation policy and development plan to obtain the best performance.