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In practice, food products tend to be contaminated with food-borne pathogens at a low inoculum level. However, the huge potential risk cannot be ignored because microbes may initiate high-speed growth suitable conditions during the food chain, such as transportation or storage. Thus, it is important to perform predictive modeling of microbial single cells. Several key aspects of microbial single-cell modeling are covered in this review. First, based on previous studies, the techniques of microbial single-cell data acquisition and growth data collection are presented in detail. In addition, the sources of microbial single-cell variability are also summarized. Due to model microbial growth, traditional deterministic mathematical models have been developed. However, most models fail to make accurate predictions at low cell numbers or at the single-cell level due to high cell-to-cell heterogeneity. Stochastic models have been a subject of great interest; and these models take into consideration the variability in microbial single-cell behavior. [ABSTRACT FROM AUTHOR]

A multi-block fluorescent amphiphilic polyurethane copolymer (TPE-PU), self-assembling into hairy, water-soluble micelles, is used as a subcellular microfilament probe in living cells. [ABSTRACT FROM AUTHOR]

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The pseudo-rapidity distribution of charged hadron multiplicity in Pb+Pb collisions at √s = 2.76 TeV is studied by using Color Glass Condensate dynamics in the fixed coupling case. We fit the HERA experimental data with heavy parton mass effect to obtain saturation exponent λ = 0.22. It is found that the charged hadron multiplicity can only describe after including heavy parton mass effect due to a large amount of heavy partons produced at large hadron collider (LHC) energy. The pomeron loop effect contribution to hadron production is also investigated. It shows that charged hadron multiplicity is underestimated by including the pomeron loop effect, which indicates that the pomeron loop effect may not exist at LHC energy. [ABSTRACT FROM AUTHOR]

Abstract: Vapor adsorption behavior and its influence on the gas sensitivity of conductive carbon black filled waterborne polyurethane composites were studied. It was found that the traditional swelling model that was applicable for the reversible variation in the composites electrical resistance induced by the solvent uptake was challenged. That is, the higher adsorption quantity was not bound to result in higher sensitivity to the vapor. On the basis of a detailed study on thermodynamics of adsorption, selective swelling of the segmented microstructure of the composites’ matrix and the preferred distribution of the conductive fillers in the matrix were found to take the responsibility. The solvent–matrix polymer interaction and the chemical characteristics of the solvents determined the relationship between the vapor adsorption behavior and the electrical responsivity of the composites. [Copyright &y& Elsevier]

Abstract: When carbon black (CB) filled waterborne polyurethane (WPU) composites are exposed to organic solvent vapors, electrical resistance of the materials increases rapidly. They can thus serve as gas sensors. To improve the composites’ performance for practical applications, crosslinking agent was added to the composite latexes, forming intra-molecular crosslinked networks among the matrix polymer of the composites. The method greatly increased the filler/matrix interfacial interaction and reduced the mobility of CB particles. In the composites that had absorbed solvent vapors, reconstruction of conduction paths through re-aggregation of the disconnected filler particulates became difficult. As a result, the unwanted negative vapor coefficient (NVC) effect was significantly weakened, while the gas sensitivity and the performance reproducibility were enhanced as well. [Copyright &y& Elsevier]

The authors of the present work developed conductive composite materials comprised of carbon black and waterborne polyurethane by latex blending. Unlike conventional polymer composites that only respond to certain specific group of solvent vapors, the present composites exhibit electrical resistance responses to a series of vapors of polar and non-polar solvents as a result of the block molecular structure of polyurethane. Under a given vapor pressure, the response rate increases with increasing temperature, but the maximum magnitude of response of the composites decreases because of the effect of vapor desorption. In the case of a constant temperature, the maximum responsivity of the composites increases with a rise in vapor pressure and the relationship follows linear regression within the p/po range of 10-4 to 2 × 10-2. Besides, the slopes of the linear dependences vary when the vapor species is changed, suggesting the possibility of quantifying and distinguishing vapors. [Copyright &y& Elsevier]

Correction for ‘A new AIE multi-block polyurethane copolymer material for subcellular microfilament imaging in living cells’ by Yu-qing Niu et al., Chem. Commun., 2017, DOI: URL10.1039/c7cc02555f/URL. [ABSTRACT FROM AUTHOR]

A fucosylated chondroitin sulfate (FCS- pg ) with highly repeated structure from Pearsonothuria graeffei was subjected to a in vitro fermentation model to investigate its fermentability and effects on human gut microflora. High performance liquid chromatography (HPLC) measurement found FCS- pg can be fermented to short chain fatty acids (SCFAs) by gut microflora from partial human fecal samples. 16S rRNA gene-based polymerase chain reaction-based denaturing gradient gel electrophoresis (PCR-DGGE) profiling and real-time quantitative PCR analysis showed that FCS- pg mainly increased the proportions of Clostridium cluster XI, Bacteriodes prevotella group, Bifidobacterium genus , Clostridium cluster I and Clostridium cluster XIVab, whereas the numbers of the Enterobacteriaceae and Lactobacillus decreased. These results indicated that FCS- pg was mainly fermented by Bacteroides , Bifidobacterium and Clostridium . It increased the content of probiotics bacteria in achieving health-enhancing effect, was slightly different than most sulfated polysaccharides from marine animals. The current study provides useful new information on the mechanism of absorption and functional activity on FCS- pg within the gastrointestinal tract of the human body. [ABSTRACT FROM AUTHOR]

Squid is considered as a healthy food by consumers because of its high nutritive value. However, it is easily decay caused by microbial contamination. This study aimed to investigate the effect of slightly acidic electrolyzed water ice (SAEW-ice) on preservation of squid. Five groups (untreated with ice (A), squid placed on the tap water (TW) ice (B) or SAEW ice (C), squid placed in the TW ice layers (D) or SAEW ice layers (E)) were conducted to evaluate the changes of sensory properties, microbial loads, pH value, peroxide value (POV), thiobarbituric acid (TBA) and total volatile basic nitrogen (TVBN) contents during the shelf life tests. The results showed that SAEW-ice was more efficient at maintaining the squid quality during storage than TW-ice. The total bacterial counts were significantly reduced by 1.46 ± 0.10 log 10 CFU/g treated by SAEW-ice and maintained relatively slow microbial growth during storage. It was also observed that SAEW-ice treatment delayed the appearance of browning and softening. Furthermore, SAEW-ice treatment also inhibited the increase of POV and maintained relatively low TBA and TVBN contents. These data indicated that SAEW-ice had the potential to ensure the microbial safety and control the quality deterioration of squid during storage, which could be a new approach worthy of further investigation. [ABSTRACT FROM AUTHOR]

Time to detection experiments (TTD) based on turbidometry using an automatic Bioscreen C is a useful and straightforward method for estimating microbial growth parameters (lag time ( λ ), growth rate ( μ ) and “work to be done” (h 0 )) at constant temperature. This study investigated the effects of slightly acidic electrolyzed water (SAEW) and heat treatment on Listeria monocytogenes growth at different recovery temperatures (10 °C, 15 °C, 25 °C, and 30 °C). Similar surviving and sublethally injured L . monocytogenes populations were obtained by heat treatment (55 °C for 10 min) and SAEW treatment (available chlorine concentration of 30 mg/l and ratio of bacteria against SAEW of 8:2 for 30 s). In these experimental conditions, stresses had greater impact on the λ and h 0 parameter in comparison with recovery temperature while there was no great change in growth rate under isothermal conditions. Larger λ values and h 0 parameters were observed in sublethal-heat injured L . monocytogenes (the maximum λ and h 0 parameters are 30.199 h and 1.6492) as compared to SAEW groups (the maximum λ and h 0 parameters are 22.634 h and 1.4396). The sensitivity analysis of SAEW and heat treatments on h 0 parameter indicated that SAEW treatment showed a higher influence. The collinearity diagnostics of independent variables [recovery temperature (T), μ , λ ] for dependent variable (h 0 parameter) demonstrated that T, μ and λ had strong collinearity. In addition, the established secondary models in this study have good performances on predicting the effect of recovery temperature on bacterial growth parameters. [ABSTRACT FROM AUTHOR]

Slightly acidic electrolyzed water (SAEW), considered as a broad-spectrum and high-performance bactericide are increasingly applied in the food industry. However, its disinfection mechanism has not been completely elucidated. This study aims to examine the disinfection efficacy and mechanism of SAEW on Staphylococcus aureus , compared with that of sodium hypochlorite (NaClO) and hydrochloric acid (HCl). SAEW treatment significantly reduced S. aureus by 5.8 log CFU/mL in 1 min, while 3.26 and 2.73 log reductions were obtained with NaClO and HCl treatments, respectively. A series of biological changes including intracellular potassium leakage, TTC-dehydrogenase relative activity and bacterial ultrastructure destruction were studied following disinfection treatment of S. aureus . The results showed that SAEW decreased the relative activity of TTC-dehydrogenase by 65.84%. Comparing intracellular potassium leakage, the SAEW treatment caused a greater percent of protein leakage (108.34%) than the NaClO (18.75%) or HCl (0.84%) treatments. These results demonstrated the potent impact SAEW had on the permeability of cell membranes. In addition, the ranking of partly agglutinated cellular inclusion formation was HCl > SAEW > NaClO. It appeared that HCl, along with its low pH value, are responsible for most of the cytoplasmic disruptions. Overall, this study demonstrated that the disinfection mechanism of SAEW was disrupting the permeability of cell membrane and the cytoplasmic ultrastructures in S. aureus cells. [ABSTRACT FROM AUTHOR]

The objective of this study was to conduct a risk assessment to determine the food poisoning risk from the consumption of milk in China that might be contaminated by Staphylococcus aureus . Data related to prevalence and concentration of S. aureus in fluid raw milk in China were collected from the literature and used to calculate the initial contamination levels. Two main consumption routes were considered and the results of the Monte Carlo simulation model indicated that the storage temperature in the processing plant and heat processing of milk in the home were the primary factors affecting the S. aureus concentration at the processing plant and the home before consumption, respectively. Other important factors were distribution of log (D)-value's for S. aureus , storage temperature and time on farm, temperature of the thermal treatment of milk, and treatment time at the dairy processing plant. To minimize the risk of milk-borne staphylococcal intoxication in China, the key step appears to be the control of storage conditions during the period after heat treatment and before consumption. The risk assessment model developed in present study provides valuable information for Chinese government and dairy processors to improve milk safety. It also could provide valuable recommendations for Chinese consumer education on safe handling of milk products. [ABSTRACT FROM AUTHOR]

Fucosylated chondroitin sulfate (fCS) from sea cucumber Isostichopus badionotus (fCS- Ib ) with a chondroitin sulfate type E (CSE) backbone and 2,4- O -sulfo fucose branches has shown excellent anticoagulant activity although has also show severe adverse effects. Depolymerization represents an effective method to diminish this polysaccharide's side effects. The present study reports a modified controlled Fenton system for degradation of fCS- Ib and the anticoagulant activity of the resulting fragments. Monosaccharides and nuclear magnetic resonance (NMR) analysis of the resulting fragments indicate that no significant chemical changes in the backbone of fCS- Ib and no loss of sulfate groups take place during depolymerization. A reduction in the molecular weight of fCS- Ib should result in a dramatic decrease in prolonging activated partial thromboplastin time and thrombin time. A decrease in the inhibition of thrombin (FIIa) by antithromin III (AT III) and heparin cofactor II (HCII), and the slight decrease of the inhibition of factor X activity, results in a significant increase of anti-factor Xa (FXa)/anti-FIIa activity ratio. The modified free-radical depolymerization method enables preparation of glycosaminoglycan (GAG) oligosaccharides suitable for investigation of clinical anticoagulant application., Competing Interests: The authors declare no conflicts of interest.

The objectives of this study were to develop a probability model of Staphylococcus aureus enterotoxin A (SEA) production as affected by water activity (a(w)), pH, and temperature in broth and assess its applicability for milk. The probability of SEA production was assessed in tryptic soy broth using 24 combinations of a(w) (0.86 to 0.99), pH (5.0 to 7.0), and storage temperature (10 to 30°C). The observed probabilities were fitted with a logistic regression to develop a probability model. The model had a concordant value of 97.5% and concordant index of 0.98, indicating that the model satisfactorily describes the probability of SEA production. The model showed that a(w), pH, and temperature were significant factors affecting the probability of toxin production. The model predictions were in good agreement with the observed values obtained from milk. The model may help manufacturers in selecting product pH and a(w) and storage temperatures to prevent SEA production.

Iron deficiency anemia (IDA) is the one of the most common nutritional problems and is encountered all over the world. This study analysed the effects of squid ink melanin-Fe (SM-Fe) on IDA in rats. Forty weanling SD male rats were used and thirty-two rats were fed an iron-deficient diet for 4 weeks. Then SM-Fe (dosages of iron is 6 mg kg(-1) BW) was given to the IDA rats once a day for 3 weeks by intragastric administration, with FeCl3 and FeSO4 (dosages of iron is 6 mg kg(-1) BW) as positive controls. While the IDA model group and the control group were administrated distilled deionized water each day for 3 weeks. The content of haemoglobin (Hb), serum iron (SI), total iron binding capacity (TIBC), serum ferritin (SF), transferrin receptor (sTfR), erythropoietin (EPO), and iron content in the liver and spleen were measured. The results showed that the content of Hb, SI, SF, EPO, iron content in the liver and spleen were significantly increased in the iron supplement groups (SM-Fe, FeCl3 and FeSO4) compared with the model group (P < 0.05), while TIBC and sTfR were significantly decreased in the iron supplement groups compared with the model group (P < 0.05). In comparison with the FeCl3 and FeSO4 groups, a higher bioavailability of iron and fewer side effects were observed in the SM-Fe group. The present study indicated that SM-Fe is an effective source of iron supplement for IDA rats and might be exploited as a new iron fortifier.

Detection of H2O2 is important for the applications in environmental protection, pharmaceutical industries, food production, and clinical control. Current colorimetric assay of H2O2 based on enzyme or nanomaterials always needs TMB or other peroxidase substrate as coloration species. Furthermore, the corresponding response time including incubation process is in order of minute. In this study, we report on the synthesis of heavily Ti(3+)-doped TiO2 composed of spherelike nanoparticles by pulsed laser ablation method. This TiO2 can directly detect H2O2 without using TMB or any other peroxidase substrate and is free from incubation process. In addition, the detection sensitivity is compatible with or better than that of the natural enzyme or other nanomaterials. Hence, the self-doped TiO2 nanoparticles provide a novel, direct, ultrafast approach for H2O2 assay application.

A creative and sensitive method has been developed for the determination of triterpene glycosides concentrations in sea cucumber ( Stichopus japonicus) and related products by using d-quinovose (6-deoxyglucose) as the measurement standard by reverse-phase high-performance liquid chromatography (HPLC) and variable-wavelength detection. d-quinovose, which is a unique monosaccharide in holostane triterpene glycosides, was liberated by acid hydrolysis and precolumn derivatized by 1-phenyl-3-methyl-5-pyrazolone (PMP). PMP-quinovose was analyzed by HPLC with 22% acetonitrile in 0.05 M KH2PO4 aquatic solution (pH 5.2) as mobile phase. The calibration curves of d-quinovose were linear within the range of 6.56-164 mg/L (r(2) > 0.995). The contents of triterpene glycosides in various S. japonicus products were determined after appropriate pretreatment methods. The concentration of triterpene glycosides was calculated by the formula C = C(qui) x alpha (alpha = 8.5). The result showed that this method was a simple, rapid, and stable method for the determination of triterpene glycosides in S. japonicus products.