The Discovery, Molecular Cloning, and Characterization of Dextransucrase LmDexA and Its Active Truncated Mutant from Leuconostoc mesenteroides NN710.

Dextransucrases play a crucial role in the production of dextran from economical sucrose; therefore, there is a pressing demand to explore novel dextransucrases with better performance. This study characterized a dextransucrase enzyme, LmDexA, which was identified from the Leuconostoc mesenteroides NN710. This bacterium was isolated from the soil of growing dragon fruit in Guangxi province, China. We successfully constructed six different N-terminal truncated variants through sequential analysis. Additionally, a truncated variant, ΔN190LmDexA, was constructed by removing the 190 amino acids fragment from the N-terminal. This truncated variant was then successfully expressed heterologously in Escherichia coli and purified. The purified ΔN190LmDexA demonstrated optimal hydrolysis activity at a pH of 5.6 and a temperature of 30 °C. Its maximum specific activity was measured to be 126.13 U/mg, with a Km of 13.7 mM. Results demonstrated a significant improvement in the heterologous expression level and total enzyme activity of ΔN190LmDexA. ΔN190LmDexA exhibited both hydrolytic and transsaccharolytic enzymatic activities. When sucrose was used as the substrate, it primarily produced high-molecular-weight dextran (>400 kDa). However, upon the addition of maltose as a receptor, it resulted in the production of a significant amount of oligosaccharides. Our results can provide valuable information for enhancing the characteristics of recombinant dextransucrase and potentially converting sucrose into high-value-added dextran and oligosaccharides.

Sleep Disturbances and Their Association With Quality of Life in Older Psychiatric Patients During the COVID-19 Pandemic.

AIMS: The negative effect of the COVID-19 pandemic on sleep quality of clinically stable psychiatric patients is unknown. This study examined the prevalence of sleep disturbances and their association with quality of life (QOL) in clinically stable older psychiatric patients during the COVID-19 pandemic. METHODS: This multicenter, cross-sectional study involved older patients attending maintenance treatment at outpatient departments of four major psychiatric hospitals in China. Patients' socio-demographic and clinical characteristics were collected. Sleep disturbances, depressive symptoms, and QOL were assessed with the Insomnia Severity Index, the 9-item Patient Health Questionnaire, and 2 items of the World Health Organization Quality of Life-Brief version, respectively. Binary logistic regression analysis was conducted to examine the independent associations of socio-demographic and clinical variables with sleep disturbances, while the association between sleep disturbances and QOL was explored with analysis of covariance. RESULTS: A total of 941 patients were recruited. The prevalence of sleep disturbances was 57.1% (95% CI: 53.9-60.2%). Analysis of covariance revealed that QOL was significantly lower in patients with sleep disturbances compared to those without. Multivariate logistic regression analysis showed that sleep disturbances were positively and independently associated with more severe depressive symptoms (OR = 1.32, 95% CI: 1.26-1.37). Compared to patients with major depressive disorder, those with other psychiatric diagnoses had a significantly higher prevalence of sleep disturbances (OR = 1.44, 95% CI: 1.00-2.08). CONCLUSION: Sleep disturbances were common among clinically stable older psychiatric patients during the COVID-19 pandemic. Considering the negative association with QOL, this subpopulation needs regular assessment and timely treatment to reduce their sleep disturbances and improve their QOL.

Network Analysis of Depression, Anxiety, Posttraumatic Stress Symptoms, Insomnia, Pain, and Fatigue in Clinically Stable Older Patients With Psychiatric Disorders During the COVID-19 Outbreak.

OBJECTIVES: The Coronavirus Disease 2019 (COVID-19) pandemic has profound negative effects on the mental health of clinically stable older patients with psychiatric disorders. This study examined the influential nodes of psychiatric problems and their associations in this population using network analysis. METHODS: Clinically stable older patients with psychiatric disorders were consecutively recruited from four major psychiatric hospitals in China from May 22 to July 15, 2020. Depressive and anxiety syndromes (depression and anxiety hereafter), insomnia, posttraumatic stress symptoms (PTSS), pain, and fatigue were measured using the Patient Health Questionnaire, General Anxiety Disorder, Insomnia Severity Index, Posttraumatic Stress Disorder Checklist - Civilian Version, and Numeric Rating Scales for pain and fatigue, respectively. RESULTS: A total of 1063 participants were included. The network analysis revealed that depression was the most influential node followed by anxiety as indicated by the centrality index of strength. In contrast, the edge connecting depression and anxiety was the strongest edge, followed by the edge connecting depression and insomnia, and the edge connecting depression and fatigue as indicated by edge-weights. The network structure was invariant by gender based on the network structure invariance test (M = .14, P = .20) and global strength invariance tests (S = .08, P = .30). CONCLUSIONS: Attention should be paid to depression and its associations with anxiety, insomnia, and fatigue in the screening and treatment of mental health problems in clinically stable older psychiatric patients affected by the COVID-19 pandemic.

Prevalence of Suicidality and its Association with Quality of Life in Older Patients with Clinically Stable Psychiatric Disorders in China During the COVID-19 Pandemic.

AIMS: The pattern of suicidality in older patients with psychiatric disorders during the COVID-19 pandemic is not clear. This study examined the prevalence of suicidality and its association with quality of life (QOL) among older clinically stable patients with psychiatric disorders during the COVID-19 pandemic. METHODS: A multicenter, cross-sectional study was conducted from May 22 to July 15, 2020, among four major tertiary psychiatric hospitals in China. Suicidality was assessed by asking 3 standardized questions. Depressive symptoms, pain, and QOL were assessed with the 9-item Patient Health Questionnaire (PHQ-9), the numeric pain rating scale (NPRS), and the World Health Organization Quality of Life Questionnaire-brief version, respectively. RESULTS: A total of 1063 clinically stable patients participated and completed the assessment. The prevalence of suicidality was 11.8% (95% CI: 9.9%-13.7%) during the COVID-19 pandemic. Multiple logistic regression analysis revealed that poor treatment adherence (P = .009, OR = 1.86, 95% CI: 1.17-2.96) and perceived illness worsening during the COVID-19 outbreak (P = .02, OR = 2.07, 95% CI: 1.15-3.73), being diagnosed with major depressive disorder (P < .001, OR = 2.79, 95% CI: 1.68-4.64), PHQ-9 total score (P < .001, OR = 1.20, 95% CI: 1.15-1.24) and NPRS total score (P = .002, OR = 1.17, 95% CI: 1.06-1.29) were associated with higher risk of suicidality. After controlling for covariates, older psychiatric patients with suicidality had lower QOL compared to those without (F(1, 1063) =16.5, P<.001). CONCLUSIONS: Suicidality was common in older patients with clinically stable psychiatric disorders during the COVID-19 pandemic. Considering its negative impact on QOL and personal suffering, routine screening and preventive suicide measures should be implemented for older psychiatric patients.

Soybean Seedling Root Segmentation Using Improved U-Net Network.

Soybean seedling root morphology is important to genetic breeding. Root segmentation is a key technique for identifying root morphological characteristics. This paper proposed a semantic segmentation model of soybean seedling root images based on an improved U-Net network to address the problems of the over-segmentation phenomenon, unsmooth root edges and root disconnection, which are easily caused by background interference such as water stains and noise, as well as inconspicuous contrast in soybean seedling images. Soybean seedling root images in the hydroponic environment were collected for annotation and augmentation. A double attention mechanism was introduced in the downsampling process, and an Attention Gate mechanism was added in the skip connection part to enhance the weight of the root region and suppress the interference of background and noise. Then, the model prediction process was visually interpreted using feature maps and class activation mapping maps. The remaining background noise was removed by connected component analysis. The experimental results showed that the Accuracy, Precision, Recall, F1-Score and Intersection over Union of the model were 0.9962, 0.9883, 0.9794, 0.9837 and 0.9683, respectively. The processing time of an individual image was 0.153 s. A segmentation experiment on soybean root images was performed in the soil-culturing environment. The results showed that this proposed model could extract more complete detail information and had strong generalization ability. It can achieve accurate root segmentation in soybean seedlings and provide a theoretical basis and technical support for the quantitative evaluation of the root morphological characteristics in soybean seedlings.

Prevalence and correlates of fatigue and its association with quality of life among clinically stable older psychiatric patients during the COVID-19 outbreak: a cross-sectional study.

BACKGROUND: The pattern of fatigue in older psychiatric patients during the COVID-19 outbreak was unknown. This study examined the prevalence of fatigue and its association with overall quality of life (overall QOL) in clinically stable older patients with psychiatric disorders during the COVID-19 outbreak. METHODS: This was a multicenter, cross-sectional study. Fatigue, depressive symptoms, pain, insomnia symptoms, and overall QOL were assessed with standardized instruments. RESULTS: A total of 1063 patients were recruited. The prevalence of fatigue was 47.1% (95%CI: 44.1-50.1%). An analysis of covariance revealed that overall QOL was significantly lower in patients with fatigue compared to those without (P = 0.011). A multiple logistic regression analysis revealed that more severe depressive symptoms (OR = 1.15, P < 0.001), insomnia symptoms (OR = 1.08, P < 0.001) and pain (OR = 1.43, P < 0.001) were significantly associated with fatigue. CONCLUSIONS: Fatigue is common among clinically stable older patients with psychiatric disorders during the COVID-19 outbreak. Considering its negative impact on overall QOL, regular assessment of fatigue and appropriate treatment warrant attention in this subpopulation.

Role of abnormal microRNA expression in Helicobacter pylori associated gastric cancer.

Epidemiological studies have shown that Helicobacter pylori (HP) infection is a risk factor for gastric cancer (GC). HP infection may induce the release of pro-inflammatory mediators, and abnormally increase the level of reactive oxygen species (ROS), nitric oxide (NO), and cytokines in mucosal epithelial cells of the stomach. However, the specific mechanism underlying the pathogenesis of HP-associated GC is still poorly understood. Recent studies have revealed that abnormal microRNA expression may affect the proliferation, differentiation, and apoptosis of mucosal epithelial cells of the stomach to further influence GC occurrence, development, and metastasis. Herein, we summarize the role of abnormal microRNAs in the regulation of HP-associated GC progression. Abnormal microRNA expression in HP-positive GC may be a biomarker for GC diagnosis, occurrence, and development as well as its targeted treatment and prognosis.

ß-Elemene inhibits peritoneal metastasis of gastric cancer cells by modulating FAK/Claudin-1 signaling.

Peritoneal metastasis is common in advanced gastric cancer patients and is typically associated with a worse prognosis. ß-Elemene is a natural compound that can be isolated from the Curcuma wenyujin plant and has been widely used in China to treat a variety of cancers. However, the anti-metastatic impacts of ß-elemene on gastric cancer remain unknown. In our study, we found that ß-elemene significantly inhibited the migration and invasive capacity of gastric cells in vitro and inhibited the capacity of gastric cancer cells to peritoneally diffuse and metastasize in vivo. Mechanistically, we demonstrated that the anti-metastatic effects of ß-elemene were exerted by downregulating the expression of Claudin-1. Furthermore, ß-elemene was found to inhibit the metastatic capacity of cells by downregulating FAK phosphorylation, which regulated Claudin-1. Overall, our result revealed that ß-elemene inhibited peritoneal metastases from gastric cancer by modulating the FAK/Claudin-1 pathway.

Effect of fermentation on water mobility and distribution in fermented cornmeal using LF-NMR and its correlation with substrate.

Cordyceps militaris (C. militaris) was utilized to ferment cornmeal by solid state fermentation. The main objective of this study was to investigate effect of fermentation on the dynamic state of water and microstructure distribution of water within cornmeal with Low-field nuclear magnetic resonance, as well as the effect on composition and microstructure properties. The spin-spin relaxation time (T2) showed significant changes in solid-state fermented cornmeal. Principal component analysis further revealed that the variations within different fermentation stage could be discriminated by the T2 parameters. Bulk water (T22) was the main form of water present and lost in substrates. The weights of different indicators, as assessed by multiple regression analysis, demonstrated that there was a strong correlation between starch and T2 relaxation. Scanning electron microscopy demonstrated that fermentation can cause the appearance of micropores. The longer relaxation time of T22 during logarithmic period can be interpreted as a loosening of the structure at the starch hydrolysis, introducing more water into the structure. Thus, the differences in composition and structure of the substrate at different fermentation time produce different T2 values.

Mental Health-Related Stigma in China.

OBJECTIVE: The past decade has been marked by a significant increase in information on stigma associated with mental disorders, but these findings have yet to be applied extensively to mental health services in China. The objective of this study was to conduct a narrative review of studies relating to stigma toward mental illness in China. METHODS: A critical search of scientific papers was conducted in the PubMed, CNKI, and WANFANG databases. The search included articles published from January 2001 to April 2016. RESULTS: Forty-two studies were evaluated and arranged into the following category groups: general public, health professionals, medical students, family members and caregivers, and people with mental disorders. CONCLUSION: We identified some results similar to those reported in foreign settings. However, some noteworthy findings concerning the stigma of health professionals, medical students, and family members towards people with mental disorders in China should be the focus of further research. Interventions designed to reduce mental health-related stigma may benefit from considering cultural influences exhibited by the Chinese population.

Psychiatric and Mental Health Nursing in China: Past, Present and Future.

The mental health service model and policy have undergone dramatic changes and are moving toward the establishment of integrated service network-based community mental health services in China. But there are still some issues, such as shortage of resources, a relatively low rate of psychiatric treatment, lack of the knowledge about mental health in the general population, and stigma associated with mental disorders. This paper summarizes the history of psychiatric and mental health nursing in China and analyzes the characteristics of the current situation. There are healthcare challenges for psychiatric and mental health nurses with the mental health services reform by government, and in this paper we discuss future trends and provide suggestions for development of the psychiatric nursing profession, and mental health services reform.

[Investigate optimum conditions and determinate changes of ß-glucosidase activity in Scrophularia root under different drying conditions].

To explore the optimum conditions of ß-glucosidase activity in Scrophularia root by using pNPG method. The extraction conditions and reaction conditions (such as extraction liquid type, reaction system, reaction time, temperature, and substrate concentration) were screened by using monofactorial experiment and homogeneous design. Then the changes of ß-glucosidase activity in Scrophularia root were detected at the drying temperature of 40-100 ℃. The results showed that citric acid phosphate buffer had better extraction effect, and the maximum absorbance produced by enzymatic reaction was present at 50 ℃ environment after reaction for 30 min. Homogeneous design experiment determined that the optimal conditions were as follows: optimal extraction liquid pH 7.0; enzymatic reaction system pH 6.0; substrate concentration 20 mmol•L⁻¹. The change of enzyme activity was affected by drying temperature and water loss rate. In the drying temperature of 60-100 ℃, the enzyme activity was reduced rapidly with the increase in water loss rate, while the activity was seen even with 0% of water at 40 and 50 ℃. This study has laid the theoretical foundation for research of hydrolysis mechanism of iridoid glycosides and optimum drying process.

[A quantitative method for simultaneous assay of seven active ingredients with one marker in Scrophularia ningpoensis root].

To establish a new quantitative method for simultaneous determination of multi-components in Scrophularia root by using high performance liquid chromatography (HPLC) and validate its feasibilities．Meanwhile,using catalpol as one chemical reference substance to establish the relative correct factors and relative retention values of aucubin,harpagide,acteoside,angoroside C,harpagoside and cinnamic acid．Then using the quantitative analysis of multi-components by single-marker (QAMS)model,the six analytes can be quantitatively determined in Scrophularia root．The method was evaluated by comparison of the quantitative results to external standard method．No significant differences were observed between the quantitative results of the two methods．The obtained RCFs were credible．It is feasible and suitable to evaluate the quality of Scrophularia root.

Research on corn starch and black bean protein isolate interactions during gelatinization and their effects on physicochemical properties of the blends.

The interaction between starch and protein during food processing is crucial for controlling food quality. This study aims to understand the interactions between corn starch and black bean protein isolate (BBPI) at various gelatinization phases and their effects on the physicochemical properties of the blends. BBPI reduced the rheological properties of the corn starch/BBPI mixed system during gelatinization, increasing light transmittance and gelatinization temperature, while decreasing total viscosity and enthalpy change. The changes in starch and protein microstructure during gelatinization indicated that BBPI adhered to the starch particle surface or partially penetrated the swollen starch particles. Fourier transform infrared spectroscopy (FT-IR) revealed that BBPI decreased the number of hydrogen bonds within starch, with no newly formed functional groups in the mixed system. Furthermore, BBPI reduced the composite relative crystallinity (RC). The effect of protein addition on water migration in the mixed system demonstrates that protein and starch compete for water during gelatinization, preventing water molecules from diffusing into starch particles.

Riboflavin-loaded soy protein isolate cold gel treated with combination of high intensity ultrasound and high hydrostatic pressure: Gel structure, physicochemical properties and gastrointestinal digestion fate.

Transglutaminase (TGase) was added to soy protein isolate (SPI) dispersion after the combination treatment of high intensity ultrasound (HIU) and high hydrostatic pressure (HHP) to catalyze the formation of cold gel, which was used to encapsulate riboflavin. The structure, physicochemical properties and in vitro digestion characteristics of riboflavin-loaded SPI cold gel were investigated. HIU-HHP combined treatment enhanced the strength, water retention, elastic property, thermal stability and protein denaturation degree of riboflavin-loaded SPI cold gels, and improved the gel network structure, resulting in a higher encapsulation efficiency of riboflavin and its chemical stability under heat and light treatment. HIU-HHP combined treatment reduced the erosion and swelling of SPI cold gel in simulated gastrointestinal fluid, and improved the sustained release effect of SPI gel on riboflavin by changing the digestion mode and rate of gel. In addition, HIU-HHP combined treated gels promoted the directional release of riboflavin in the simulated intestinal fluid, thereby improving its bioaccessibility, which was related to the secondary structure orderliness, tertiary conformation tightness and aggregation degree of protein during the gastrointestinal digestion. Therefore, HIU-HHP combined treatment technology had potential application value in improving the protection, sustained/controlled release and delivery of SPI cold gels for sensitive bioactive compounds.

Effects of alginate synergized with polyphenol compounds on the retrogradation properties of corn starch.

This study aimed to investigate the impact of alginate (AG) on the retrogradation properties of corn starch (CS) in conjunction with three phenolic compounds, including naringin (NA), rutin (RT), and soy isoflavones (SI). The findings indicated that AG, NA, RT, and SI collectively resulted in a significant reduction in the hardness, retrogradation enthalpy, and relaxation time of CS gel. This effect was more pronounced when compared to NA, RT, and SI individually. The findings suggested that the elemental system comprising AG, phenolic compounds, and CS yielded enhanced water retention capacity and thermal stability. Moreover, a noticeable decrease in the short-range ordered structure and crystallinity was observed, indicating that AG and phenolic compounds effectively inhibited the retrogradation of CS; notably, the synergistic interaction between AG and SI resulted in the most favorable outcome. The results of this study provide new ideas for the design, development, and quality improvement of starch-based food.

Understanding the multiscale structure and in vitro digestibility changes of corn starch-ferulic acid complexes induced by high hydrostatic pressure.

High hydrostatic pressure (HHP) was used to synthesize corn starch (CS) and ferulic acid (FA) complex (CS-FA). Its effects on the structure of the complex at multiple scales and its digestibility were examined. The results demonstrated that HHP significantly influenced the digestibility of the CS-FA complex, decreasing the content of rapidly digestible starch (RDS) while increasing slowly digestible starch (SDS) and resistant starch (RS). Notably, the combined SDS and RS content in the HHP-treated CS-FA complex with 2.0 % FA addition (38.13 %) was significantly higher (p < 0.05) than those in the CS-FA complex without HHP treatment (29.21 %) and pure CS (21.72 %). The results indicated that HHP treatment reduced the enthalpy change (ΔH), number of short-range order structures, and relative crystallinity (RC) while increasing the average particle size of these CS-FA complexes. This treatment also increased the proportion of amorphous starch regions and the degree of agglomeration between the starch and FA. HHP treatment-induced CS-FA complexes exhibited a denser fractal structure and higher short-range order, affecting the interaction sites between the starch and digestive enzymes. These findings suggest the potential application of HHP treatment and FA in modulating the postprandial glycemic response to starchy food.

Effect of Microwave Intermittent Drying on the Structural and Functional Properties of Zein in Corn Kernels.

Microwave intermittent drying was carried out on newly harvested corn kernels to study the effects of different microwave intermittent powers (900 W, 1800 W, 2700 W, and 3600 W) on the structural and functional properties of zein in corn kernels. The results showed that microwave drying could increase the thermal stability of zein in corn kernels. The solubility, emulsification activity index, and surface hydrophobicity increased under 1800 W drying power, which was due to the unfolding of the molecular structure caused by the increase in the content of irregular structure and the decrease in the value of particle size. At a drying power of 2700 W, there was a significant increase in grain size values and ß-sheet structure. This proves that at this time, the corn proteins in the kernels were subjected to the thermal effect generated by the higher microwave power, which simultaneously caused cross-linking and aggregation within the proteins to form molecular aggregates. The solubility, surface hydrophobicity, and other functional properties were reduced, while the emulsification stability was enhanced by the aggregates. The results of the study can provide a reference for the in-depth study of intermittent corn microwave drying on a wide range of applications of zein in corn kernels.

Development of a chemiluminescence enzyme-linked immunosorbent assay for the simultaneous detection of imidaclothiz and thiacloprid in agricultural samples.

A novel and sensitive enhanced chemiluminescence enzyme-linked immunosorbent assay (ECL-ELISA) for the simultaneous analysis of imidaclothiz and thiacloprid is described. The concentrations of coating antibodies and enzyme tracers were optimised by three different ECL-ELISA formats. Under the optimised conditions, when anti-imidaclothiz polyclonal and anti-thiacloprid polyclonal antibodies were immobilised in a single well, single-enzyme tracer ECL-ELISA was used to screen the corresponding pesticide residue, and multi-enzyme tracer ECL-ELISA was used for the analysis of imidaclothiz and thiacloprid residue mixtures. The average recoveries of the two pesticides from spiked tomato, cabbage, and rice samples were in the range of 83.7-117%. Meanwhile, the results showed that the multi-enzyme tracer ECL-ELISA could be applied to the accurate analysis of different proportions of imidaclothiz and thiacloprid (1 : 4 to 4 : 1, m/m) when the gross residues ranged from 20 to 250 µg kg(-1). The results of the multi-enzyme tracer ECL-ELISA in the real tomato samples correlated well with those of high-performance liquid chromatography, with a correlation coefficient of 0.996. Therefore, this new strategy for developing immunoassays is suitable for the simultaneous quantitative detection of imidaclothiz and thiacloprid residues in agricultural samples.

Study on physicochemical, structural, and functional properties of Zhengdan958 and Xianyu335 cornstarch from newly harvested corn under postharvest ripening conditions at ambient temperature.

The importance of starch in nutrition and industry is unquestionable. This study investigated the changes in physicochemical, structural, and functional properties of cornstarch from newly harvested Zhengdan958 (Zd958) and Xianyu335 (Xy335) corn during for 0, 20, 40, and 60 d at ambient temperature. The results showed no significant changes in the proximate components and apparent structure of Zd958 and Xy335 cornstarch under postharvest ripening conditions. Compared with 0 d, the molecular weight distribution and mass fraction of Zd958 and Xy335 cornstarch have changed significantly, the relative crystallinity (RC) has significantly increased from 26.4% to 26.5%-28.8% and 28.4%, and R1045/1022 has significantly increased from 0.828 to 0.826 to 0.843 and 0.883, respectively. The changes in structure indicated that the synthesis and rearrangement of cornstarch molecules formed highly ordered crystalline structures, and the ordered structures of long-range and short-range molecules increased. Moreover, the changes in structure affected the pasting characteristics and texture profiles of cornstarch, therefore, affecting the final food quality.