Long Non-Coding RNA B3GALT5-AS1 Suppresses Keloid Progression by Regulating the ß-Trcp1-Mediated Ubiquitination of HuR.

Background: lncRNA ß­1,3­galactosyltransferase 5­AS1 (B3GALT5-AS1) plays a vital regulatory role in colon and gastric cancers. However, the biological functions and regulatory mechanisms of B3GALT5-AS1 in keloid progression remain unknown. This study aims to investigate the molecular mechanisms in the B3GALT5-AS1-regulated keloid proliferation and invasion. Methods: Secondary mining of the lncRNA sequencing data from GSE158395 was conducted to screen differentially expressed lncRNAs between keloid and normal tissues. MTT, cell migration and invasion assays were performed to detect the effects of B3GALT5-AS1 on keloid fibroblasts (KFs) proliferation and metastasis. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were also determined to evaluate glycolysis in KFs. RNA pull-down and RNA-protein immunoprecipitation assays were used to confirm the interaction between B3GALT5-AS1 and Hu-Antigen R (HuR). Further ubiquitination and rescue experiments were performed to elucidate the regulatory relationship between B3GALT5-AS1 and HuR. Results: B3GALT5-AS1 was significantly down-regulated in keloid tissues and fibroblasts. B3GALT5-AS1 overexpression significantly inhibited KFs proliferation, glycolysis, invasion, and migration and promoted cell apoptosis, whereas silencing B3GALT5-AS1 inhibited these effects. Moreover, B3GALT5-AS1 binds to HuRand reduces its stability through ß-Transducin repeats-containing protein 1 (ß-Trcp1)-mediated ubiquitination. Overexpression of HuR reversed the inhibition of B3GALT5-AS1 on cell proliferation, migration, and invasion in KFs, where glycolysis pathway was involved. Conclusion: Our findings illustrate that B3GALT5-AS1 has great effect on inhibition of keloid formation, which provides a potential target for keloid therapy.

Triglyceride-glucose index in early pregnancy predicts the risk of gestational diabetes: a prospective cohort study.

OBJECTIVE: This study aimed to investigate the association between the triglyceride-glucose (TyG) index in early pregnancy and the development of gestational diabetes mellitus (GDM) in the second trimester. The primary objectives were to evaluate the predictive potential of the TyG index for GDM, determine the optimal threshold value of the TyG index for GDM assessment, and compare the predictive performance of the TyG index alone versus its combination with maternal age and pre-pregnancy body mass index on GDM. Moreover, the study explored the association between the TyG index in early pregnancy and the risk of other pregnancy-related complications (PRCs), such as placental abruption and gestational hypertension. PATIENTS AND METHODS: This prospective cohort study recruited 1,624 pregnant women who underwent early pregnancy antenatal counseling and comprehensive assessments with continuous monitoring until delivery. To calculate the TyG index, health indicators, including maternal triglycerides and fasting plasma glucose, were measured in early pregnancy (< 14 weeks of gestation). The predictive power of the TyG index for evaluating GDM in Chinese pregnant women was determined using multifactorial logistic regression to derive the odds ratios and 95% confidence interval (CI). Subgroup analyses were conducted, and the efficacy of the TyG index in predicting PRCs was assessed via receiver operating characteristic (ROC) curve analysis and restricted cubic spline, with the optimal cutoff value calculated. RESULTS: Logistic regression analyses revealed a 2.10-fold increase in the GDM risk for every 1-unit increase in the TyG index, after adjusting for covariates. The highest GDM risk was observed in the group with the highest TyG index compared with the lowest quintile group (odds ratios: 3.25; 95% CI: 2.23-4.75). Subgroup analyses indicated that exceeding the recommended range of gestational weight gain and an increased GDM risk were significantly associated (P = 0.001). Regarding predictive performance, the TyG index exhibited the highest area under the curve (AUC) value in the ROC curve for GDM (AUC: 0.641, 95% CI: 0.61-0.671). The optimal cutoff value was 8.890, with both sensitivity and specificity of 0.617.The combination of the TyG index, maternal age, and pre-pregnancy body mass index proved to be a superior predictor of GDM than the TyG index alone (AUC: 0.672 vs. 0.641, P < 0.01). After adjusting for multiple factors, the analyses indicated that the TyG index was associated with an increased risk of gestational hypertension. However, no significant association was noted between the TyG index and the risk of preeclampsia, placental abruption, intrauterine distress, or premature rupture of membranes. CONCLUSION: The TyG index can effectively identify the occurrence of GDM in the second trimester, aligning with previous research. Incorporating the TyG index into routine clinical assessments of maternal health holds significant practical implications. Early identification of high-risk groups enables healthcare providers to implement timely interventions, such as increased monitoring frequency for high-risk pregnant women and personalized nutritional counseling and health education. These measures can help prevent or alleviate potential maternal and infant complications, thereby enhancing the overall health outcomes for both mothers and babies.

Graph Neural Network-Based Efficient Subgraph Embedding Method for Link Prediction in Mobile Edge Computing.

Link prediction is critical to completing the missing links in a network or to predicting the generation of new links according to current network structure information, which is vital for analyzing the evolution of a network, such as the logical architecture construction of MEC (mobile edge computing) routing links of a 5G/6G access network. Link prediction can provide throughput guidance for MEC and select appropriate c nodes through the MEC routing links of 5G/6G access networks. Traditional link prediction algorithms are always based on node similarity, which needs predefined similarity functions, is highly hypothetical and can only be applied to specific network structures without generality. To solve this problem, this paper proposes a new efficient link prediction algorithm PLAS (predicting links by analysis subgraph) and its GNN (graph neural network) version PLGAT (predicting links by graph attention networks) based on the target node pair subgraph. In order to automatically learn the graph structure characteristics, the algorithm first extracts the h-hop subgraph of the target node pair, and then predicts whether the target node pair will be linked according to the subgraph. Experiments on eleven real datasets show that our proposed link prediction algorithm is suitable for various network structures and is superior to other link prediction algorithms, especially in some 5G MEC Access networks datasets with higher AUC (area under curve) values.

Prevalence, risk factors, impact and management of pneumonia among preschool children in Chinese seven cities: a cross-sectional study with interrupted time series analysis.

BACKGROUND: Pneumonia is a common disease worldwide in preschool children. Despite its large population size, China has had no comprehensive study of the national prevalence, risk factors, and management of pneumonia among preschool children. We therefore investigated the prevalence of pneumonia among preschool children in Chinese seven representative cities, and explore the possible risk factors of pneumonia on children, with a view to calling the world's attention to childhood pneumonia to reduce the prevalence of childhood pneumonia. METHODS: Two group samples of 63,663 and 52,812 preschool children were recruited from 2011 and 2019 surveys, respectively. Which were derived from the cross-sectional China, Children, Homes, Health (CCHH) study using a multi-stage stratified sampling method. This survey was conducted in kindergartens in seven representative cities. Exclusion criteria were younger than 2 years old or older than 8 years old, non-permanent population, basic information such as gender, date of birth and breast feeding is incomplete. Pneumonia was determined on the basis of parents reported history of clearly diagnosed by the physician. All participants were assessed with a standard questionnaire. Risk factors for pneumonia, and association between pneumonia and other respiratory diseases were examined by multivariable-adjusted analyses done in all participants for whom data on the variables of interest were available. Disease management was evaluated by the parents' reported history of physician diagnosis, longitudinal comparison of risk factors in 2011 and 2019. RESULTS: In 2011 and 2019, 31,277 (16,152 boys and 15,125 girls) and 32,016 (16,621 boys and 15,395 girls) preschool children aged at 2-8 of permanent population completed the questionnaire, respectively, and were thus included in the final analysis. The findings showed that the age-adjusted prevalence of pneumonia in children was 32.7% in 2011 and 26.4% in 2019. In 2011, girls (odds ratio [OR] 0.91, 95%CI [confidence interval]0.87-0.96; p = 0.0002), rural (0.85, 0.73-0.99; p = 0.0387), duration of breastfeeding ≥ 6 months(0.83, 0.79-0.88; p < 0.0001), birth weight (g) ≥ 4000 (0.88, 0.80-0.97; p = 0.0125), frequency of putting bedding to sunshine (Often) (0.82, 0.71-0.94; p = 0.0049), cooking fuel type (electricity) (0.87, 0.80-0.94; p = 0.0005), indoor use air-conditioning (0.85, 0.80-0.90; p < 0.0001) were associated with a reduced risk of childhood pneumonia. Age (4-6) (1.11, 1.03-1.20; p = 0.0052), parental smoking (one) (1.12, 1.07-1.18; p < 0.0001), used antibiotics (2.71, 2.52-2.90; p < 0.0001), history of parental allergy (one and two) (1.21, 1.12-1.32; p < 0.0001 and 1.33, 1.04-1.69; p = 0.0203), indoor dampness (1.24, 1.15-1.33; p < 0.0001), home interior decoration (1.11, 1.04-1.19; p = 0.0013), Wall painting materials (Paint) (1.16, 1.04-1.29; p = 0.0084), flooring materials (Laminate / Composite wood) (1.08, 1.02-1.16; p = 0.0126), indoor heating mode(Central heating)(1.18, 1.07-1.30, p = 0.0090), asthma (2.38, 2.17-2.61; p < 0.0001), allergic rhinitis (1.36, 1.25-1.47; p < 0.0001), wheezing (1.64, 1.55-1.74; p < 0.0001) were associated with an elevated risk of childhood pneumonia; pneumonia was associated with an elevated risk of childhood asthma (2.53, 2.31-2.78; p < 0.0001), allergic rhinitis (1.41, 1.29-1.53; p < 0.0001) and wheezing (1.64, 1.55-1.74; p < 0.0001). In 2019, girls (0.92, 0.87-0.97; p = 0.0019), duration of breastfeeding ≥ 6 months (0.92, 0.87-0.97; p = 0.0031), used antibiotics (0.22, 0.21-0.24; p < 0.0001), cooking fuel type (Other) (0.40, 0.23-0.63; p = 0.0003), indoor use air-conditioning (0.89, 0.83-0.95; p = 0.0009) were associated with a reduced risk of childhood pneumonia. Urbanisation (Suburb) (1.10, 1.02-1.18; p = 0.0093), premature birth (1.29, 1.08-1.55; p = 0.0051), birth weight (g) < 2500 (1.17, 1.02-1.35; p = 0.0284), parental smoking (1.30, 1.23-1.38; p < 0.0001), history of parental asthma (One) (1.23, 1.03-1.46; p = 0.0202), history of parental allergy (one and two) (1.20, 1.13-1.27; p < 0.0001 and 1.22, 1.08-1.37; p = 0.0014), cooking fuel type (Coal) (1.58, 1.02-2.52; p = 0.0356), indoor dampness (1.16, 1.08-1.24; p < 0.0001), asthma (1.88, 1.64-2.15; p < 0.0001), allergic rhinitis (1.57, 1.45-1.69; p < 0.0001), wheezing (2.43, 2.20-2.68; p < 0.0001) were associated with an elevated risk of childhood pneumonia; pneumonia was associated with an elevated risk of childhood asthma (1.96, 1.72-2.25; p < 0.0001), allergic rhinitis (1.60, 1.48-1.73; p < 0.0001) and wheezing (2.49, 2.25-2.75; p < 0.0001). CONCLUSIONS: Pneumonia is prevalent among preschool children in China, and it affects other childhood respiratory diseases. Although the prevalence of pneumonia in Chinese children shows a decreasing trend in 2019 compared to 2011, a well-established management system is still needed to further reduce the prevalence of pneumonia and reduce the burden of disease in children.

Prevalence and influencing factors of wheeze and asthma among preschool children in Urumqi city: a cross-sectional survey.

To investigate the prevalence and indoor environmental influencing factors of wheeze and asthma among preschool children in Urumqi, Xinjiang, China to provide a strong basis for prevention and control. In August 2019, a cross-sectional study involving 8153 preschool children was conducted in 60 kindergartens in Urumqi. The ALLHOME-2 questionnaire was used for childhood wheeze and asthma survey, and the dampness in buildings and health (DBH) questionnaire was used for the childhood home dwelling and living environment survey. Multivariate unconditional logistic regression was then used to analyze the potential influencing factors of childhood asthma and wheeze. The prevalence of wheeze and asthma in children was 4.7% and 2.0%, respectively. Multivariate unconditional logistic regression results suggested that ethnicity other than the Han Chinese (odds ratio (OR) 1.39, 95% confidence interval (CI) 1.05-1.84), caesarean section (OR 1.24, 95% CI 1.00-1.53), family history of asthma (OR 5.00, 95% CI 3.36-7.44), carpet or floor bedding at home (OR 1.40, 95% CI 1.05-1.87), purchasing new furniture in the mother's residence during pregnancy (OR 1.58, 95% CI 1.06-2.36), pet keeping in the residence at aged 0-1 year (OR 1.55, 95% CI 1.13-2.13), passive smoking by child in the current residence (OR 1.35, 95% CI 1.01-1.80), and having mould or hygroma in the child's residence at aged 0-1 year (OR 1.72, 95% CI 1.12-2.64) were risk factors for wheeze. In addition, Girls (OR 0.73, 95% CI 0.59-0.90) was a protective factor for wheeze. Caesarean section (OR 1.46, 95% CI 1.06-2.00), family history of asthma (OR 7.06, 95% CI 4.33-11.53), carpet or floor bedding at home (OR 2.20, 95% CI 1.50-3.23), and pet keeping in the residence at aged 0-1 year (OR 1.64, 95% CI 1.04-1.83) were risk factors for asthma, whereas Girls (OR 0.58, 95% CI 0.42-0.80) was a protective factor for asthma. This survey indicates that the purchase of new furniture, the placement of carpet or floor bedding in the child's residence, the pets keeping, room dampness or moldy phenomena, and passive smoking may all contribute to an elevated risk of wheeze or asthma in children.

Converting Plastic Wastes to Naphtha for Closing the Plastic Loop.

To solve the serious environmental problem and huge resource waste of plastic pollution, we report a tandem catalytic conversion of low-density polyethylene (LDPE) into naphtha, the key feedstock for renewable plastic production. Using ß zeolite and silicalite-1-encapsulated Pt nanoparticles (Pt@S-1), a naphtha yield of 89.5% is obtained with 96.8% selectivity of C5-C9 hydrocarbons at 250 °C. The acid sites crack long-chain LDPE into olefin intermediates, which diffuse within the channels of Pt@S-1 to encounter Pt nanoparticles. The hydrogenation over confined metal matches cracking steps by selectively shipping the olefins with right size, and the rapid diffusion boosts the formation of narrow-distributed alkanes. A conceptual upgrading indicates it is suitable for closing the plastic loop, with a significant energy saving of 15% and 30% reduced greenhouse gas emissions.

Prevalence and indoor environment risk factors of otitis among preschool children in Urumqi, China.

OBJECTIVE: To investigate the indoor environmental risk factors to provide measures for the prevention and control of otitis in preschool children. METHOD: In this cross-sectional study, a questionnaire survey was administered to preschool children aged 2-7 years from 60 kindergartens in six districts of Urumqi City in August 2019. Multiple regression was run to predict influence factors for otitis media in preschool children. RESULT: A total of 8153 valid questionnaires were collected. After adjusting for age, the prevalence of otitis among preschool children in Urumqi was 13.1%. Multivariate logistic regression showed that previous antibiotic treatment, treatment with one to two antibiotics before 1 year of age, presence of walls with aqueous or latex paint, use of carpet floor bedding in rooms, newly decorated homes of mothers before pregnancy, purchase of new furniture for homes of children at 0-1 year of age, and presence of flowering plants in the residence of children at 0-1 years of age were all identified as risk factors for the development of otitis in children. CONCLUSION: Parents should also pay attention to indoor living environments, and reduce indoor renovation in the homes of children during their growth and development, which can positively improve children's indoor living environment, thus effectively preventing otitis in preschool children.

Parental, gestational, and early-life exposure to indoor environmental hazardous factors on allergic rhinitis among preschool children in Urumqi City: a case-control study.

OBJECTIVE: Allergic rhinitis (AR) is a disease associated with impaired quality of life and heredity. This study aimed to investigate the association of allergic rhinitis in preschool children with exposure to indoor environment-related factors early in life. METHODS: In August 2019, the authors implemented a study among 2020 preschool children in Urumqi City using a case-control design. The study included parental reports for the occurrence of AR in children, parental history of respiratory disease, and indoor environmental correlates of maternal exposure from 1 year prior to pregnancy until the child's age of 0-1 year. RESULTS: Mode of birth (cesarean section) (OR = 1.31, 95% CI = 1.02∼1.67), father with AR (OR = 2.67, 95% CI = 2.08∼3.44), mother with AR (OR = 3.70, 95% CI = 2.88∼4.74), mother with asthma (OR = 3.11, 95% CI = 1.18∼8.20), and mother with newly purchased furniture in the parents' residence during pregnancy (OR = 1.49, 95% CI = 1.03∼2.14) were risk factors for AR in children. CONCLUSIONS: The focus of allergic rhinitis should be on children with a family history of AR and asthma and cesarean delivery. Primary prevention efforts for AR in preschool children are avoiding exposure of children to indoor environmental hazardous factors early in life.

Parental, gestational, and early-life exposure to indoor environmental hazardous factors on allergic rhinitis among preschool children in Urumqi City: a case-control study

Abstract Objective Allergic rhinitis (AR) is a disease associated with impaired quality of life and heredity. This study aimed to investigate the association of allergic rhinitis in preschool children with exposure to indoor environment-related factors early in life. Methods In August 2019, the authors implemented a study among 2020 preschool children in Urumqi City using a case-control design. The study included parental reports for the occurrence of AR in children, parental history of respiratory disease, and indoor environmental correlates of maternal exposure from 1 year prior to pregnancy until the child's age of 0-1 year. Results Mode of birth (cesarean section) (OR = 1.31, 95% CI = 1.02∼1.67), father with AR (OR = 2.67, 95% CI = 2.08∼3.44), mother with AR (OR = 3.70, 95% CI = 2.88∼4.74), mother with asthma (OR = 3.11, 95% CI = 1.18∼8.20), and mother with newly purchased furniture in the parents' residence during pregnancy (OR = 1.49, 95% CI = 1.03∼2.14) were risk factors for AR in children. Conclusions The focus of allergic rhinitis should be on children with a family history of AR and asthma and cesarean delivery. Primary prevention efforts for AR in preschool children are avoiding exposure of children to indoor environmental hazardous factors early in life.

Prevalence and indoor environment risk factors of otitis among preschool children in Urumqi, China

Abstract Objective To investigate the indoor environmental risk factors to provide measures for the prevention and control of otitis in preschool children. Method In this cross-sectional study, a questionnaire survey was administered to preschool children aged 2-7 years from 60 kindergartens in six districts of Urumqi City in August 2019. Multiple regression was run to predict influence factors for otitis media in preschool children. Result A total of 8153 valid questionnaires were collected. After adjusting for age, the prevalence of otitis among preschool children in Urumqi was 13.1%. Multivariate logistic regression showed that previous antibiotic treatment, treatment with one to two antibiotics before 1 year of age, presence of walls with aqueous or latex paint, use of carpet floor bedding in rooms, newly decorated homes of mothers before pregnancy, purchase of new furniture for homes of children at 0-1 year of age, and presence of flowering plants in the residence of children at 0-1 years of age were all identified as risk factors for the development of otitis in children. Conclusion Parents should also pay attention to indoor living environments, and reduce indoor renovation in the homes of children during their growth and development, which can positively improve children's indoor living environment, thus effectively preventing otitis in preschool children.

An Overview of Laser Metal Deposition for Cladding: Defect Formation Mechanisms, Defect Suppression Methods and Performance Improvements of Laser-Cladded Layers.

With the development of society and the economy, there is an increasing demand for surface treatment techniques that can efficiently utilize metal materials to obtain good performances in the fields of mechanical engineering and the aerospace industry. The laser metal deposition (LMD) technique for cladding has become a research focus in recent years because of its lower dilution rate, small heat-effect zone and good metallurgical bonding between the coating and substrate. This paper reviews the simulation technology for the melt pool's grain growth mechanism, temperature and stress distribution that are directly related to defect formation in LMD technology. At the same time, the defect suppression method and the performance improvement method of the cladded layer in LMD technology are introduced. Finally, it is pointed out that the active selection of materials according to the required performance, combined with the controllable processing technology, to form the corresponding microstructure, and finally, to actively realize the expected function, is the future development direction of LMD technology.

Risk assessment for precise intervention of COVID-19 epidemic based on available big data and spatio-temporal simulation method: Empirical evidence from different public places in Guangzhou, China.

Risk assessment of the intra-city spatio-temporal spreading of COVID-19 is important for providing location-based precise intervention measures, especially when the epidemic occurred in the densely populated and high mobile public places. The individual-based simulation has been proven to be an effective method for the risk assessment. However, the acquisition of individual-level mobility data is limited. This study used publicly available datasets to approximate dynamic intra-city travel flows by a spatio-temporal gravity model. On this basis, an individual-based epidemic model integrating agent-based model with the susceptible-exposed-infectious-removed (SEIR) model was proposed and the intra-city spatio-temporal spreading process of COVID-19 in eleven public places in Guangzhou China were explored. The results indicated that the accuracy of dynamic intra-city travel flows estimated by available big data and gravity model is acceptable. The spatio-temporal simulation method well presented the process of COVID-19 epidemic. Four kinds of spatial-temporal transmission patterns were identified and the pattern was highly dependent on the urban spatial structure and location. It indicated that location-based precise intervention measures should be implemented according to different regions. The approach of this research can be used by policy-makers to make rapid and accurate risk assessments and to implement intervention measures ahead of epidemic outbreaks.

Optimizing Spatial Allocation of COVID-19 Vaccine by Agent-Based Spatiotemporal Simulations.

Optimizing allocation of vaccine, a highly scarce resource, is an urgent and critical issue during fighting against on-going COVID-19 epidemic. Prior studies suggested that vaccine should be prioritized by age and risk groups, but few of them have considered the spatial prioritization strategy. This study aims to examine the spatial heterogeneity of COVID-19 transmission in the city naturally, and optimize vaccine distribution strategies considering spatial prioritization. We proposed an integrated spatial model of agent-based model and SEIR (susceptible-exposed-infected-recovered). It simulated spatiotemporal process of COVID-19 transmission in a realistic urban context. Individual movements were represented by trajectories of 8,146 randomly sampled mobile phone users on December 28, 2016 in Guangzhou, China, 90% of whom aged 18-60. Simulations were conducted under seven scenarios. Scenarios 1 and 2 examined natural spreading process of COVID-19 and its final state of herd immunity. Scenarios 3-6 applied four vaccination strategies (random strategy, age strategy, space strategy, and space & age strategy), and identified the optimal vaccine strategy. Scenario 7 assessed the most appropriate vaccine coverage. The results demonstrates herd immunity is heterogeneously distributed in space, thus, vaccine intervention strategies should be spatialized. Among four strategies, space & age strategy is substantially most efficient, with 7.7% fewer in attack rate and 44 days longer than random strategy under 20% vaccine uptake. Space & age strategy requires 30%-40% vaccine coverage to control the epidemic, while the coverage for a random strategy is 60%-70% as a comparison. The application of our research would greatly improves the effectiveness of the vaccine usability.

Geographic Ecological Momentary Assessment (GEMA) of environmental noise annoyance: the influence of activity context and the daily acoustic environment.

BACKGROUND: Noise annoyance is considered to be the most widespread and recognized health effect of environmental noise. Previous research is mostly based on the static study of residential environmental noise, but few studies have focused on the effects of noise exposure in different activity contexts on real-time annoyance. The two deficiency are that they neglect the influence of activity context besides residence and fail to reflect the difference of time-scale effect of noise influence. METHODS: Using portable noise and air sensors, GPS-equipped mobile phones, questionnaire survey, and geographic ecological momentary assessment (GEMA), this paper measured the environmental noise and real-time noise annoyance of participants at different activity places. Hierarchical logistic regression models were used to examine the effects of environmental noise on people's real-time annoyance. The paper further considered the influence of the geographic context of the activity places and daily acoustic environment on participants' real-time annoyance. Further, a nonlinear regression model was constructed using Random Forest to further examine the nonlinear relationship between environmental noise and real-time annoyance. RESULTS: The results showed that: (1) the average cumulative equivalent sound level during was 55 dB (A) when the participants responded to the EMA surveys; (2) Only the temperature of activity places had an influence on momentary annoyance and the higher the temperature, the more likely participants were annoyed; (3) Participants with higher perception of noise pollution in residential communities were more likely to be annoyed. However, participants with higher daily exposure to noise were less likely to feel annoyed; (4) The threshold value of the effect of noise on real-time annoyance was 58 dB (A) to 78 dB (A). CONCLUSIONS: These findings can guide the development of urban planning and environmental noise standards and also provide a reference for noise barrier requirements for different activity places.

Extracellular expression of Aerococcus viridans pyruvate oxidase in recombinant Escherichia coli through SecB co-expression.

Pyruvate oxidase (POD) is an important enzyme used for clinical applications and biochemical analyses, and recombinant Escherichia coli strains expressing Aerococcus viridans POD have been frequently employed for obtaining high POD yield. Although significant progress has been achieved in increasing recombinant POD production, intracellular POD expression and weak stability of POD make POD purification difficult. In this study, extracellular POD expression was achieved by co-expression of chaperone SecB under three promoters (T7, lac, bla). The weakest promoter, bla, when compared with T7 and lac promoters, provided the optimum extracellular POD activity among these three promoters. After optimization of cultivation conditions, such as IPTG concentration, pH, and temperature, the extracellular POD yield increased to 795.7 U L-1. Furthermore, by using glycine to disrupt recombinant E. coli cell wall and Cu2+ ions as POD stabilizer, the final extracellular POD yield reached 2926.3 U L-1. The expression intensity of chaperone had significant influence on heterologous protein secretion, and the high yield of extracellular POD implies potential widespread POD production and application.

[Rapid determination of 48 contaminant residues in food contact plastic products by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry coupled with microwave-assisted extraction].

An ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UPLC-Q Orbitrap HRMS) method was developed for the rapid determination of 48 contaminant residues in food plastic packaging materials. The samples were extracted with methanol using microwave-assisted extraction. The separation of the 48 contaminants was performed on a CAPCELL PAK MG Ⅱ C18 column (150 mm×2.0 mm, 5 µm) with gradient elution. Methanol (containing 0.04% (v/v) formic acid) and water (containing 0.04% (v/v) formic acid and 20 mmol/L ammonium acetate) were used as mobile phases. The compounds were detected under the full scan/date dependent-MS/MS (Full MS/dd-MS2) mode with a heated electrospray ionization (HESI) source. The calibration curves were linear with correlation coefficients no less than 0.9950. The limits of detection (LODs) ranged from 0.1 to 1.0 µg/kg. The average spiked recoveries of the 48 target compounds were between 71.2% and 108.8%, with relative standard derivations (RSDs) ranging from 2.2% to 11.8% (n=6). Compared to previous methods, this method has advantages of simpler sample preparation and higher sensitivity.

[Rapid determination of 25 drug residues in aquatic products by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry].

An ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UPLC-Q Orbitrap HRMS) method was developed for the rapid screening of 25 drug residues in aquatic products by the application of a novel enhanced matrix removal of lipids (EMR-Lipid). The samples were extracted with acetonitrile, cleaned-up with EMR-Lipid, and salted out with 3.0 g sodium chloride and 3.0 g sodium sulfate. The separation of the 25 drug residues was performed on an ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm) with gradient elution. Acetonitrile containing 0.1% (v/v) formic acid and 0.1% (v/v) formic acid aqueous solution were used as mobile phases. The compounds were detected by Full scan/date dependent MS/MS (Full MS/dd-MS2) via heated electrospray ionization (HESI) source. The calibration curves were linear with correlation coefficients (r) greater than 0.997. The limits of detection (LODs) ranged from 0.1 µg/kg to 1.0 µg/kg. The average spiked recoveries of the 25 target compounds were between 70.1% and 108.9% with relative standard derivations (RSDs) from 2.1% to 13.8%. Compared with the previous methods, this method has characteristics of simpler sample preparation and higher sensitivity.

Optimization for production of exopolysaccharides with antitumor activity in vitro from Paecilomyces hepiali.

In the present study, optimal medium for the growth of mycelia and the production of exopolysaccharides from Paecilomyces hepiali HN1 (PHEPS) in submerged culture was investigated. As a result, the maximum production of mycelia (12.98 ± 0.14 g/L) and PHEPS (5.33 ± 0.11 g/L) were achieved under the optimal medium of sucrose 46.08 g/L, yeast extract 4.71 g/L, (NH4)2SO4 5.72 g/L, KH2PO4 1.70 g/L, CaCl2 0.50 g/L, MgSO4 0.50 g/L, potato extract 1% and malt extract 1%. Furthermore, the antitumor activity of PHEPS in vitro was evaluated by using three cell lines of human liver tumor HepG2 cells, breast cancer MCF-7 cells and cervical cancer Hela cells. It was found that PHEPS exhibited relative higher anti-proliferative activity against HepG2 cells than MCF-7 cells and Hela cells. At a concentration of 500 µg/mL and 72 h treatment, the inhibition rate of PHEPS on HepG2 cells reached to 62.58%. All these results suggested that PHEPS could be explored as novel natural antitumor agent with great potential application.