Cascade Synthesis from Cyclohexane to ϵ-Caprolactone by Visible-Light-Driven Photocatalysis Combined with Whole-Cell Biological Oxidation.

Cyclohexane was directly oxy-functionalised to ϵ-caprolactone through a cascade reaction sequence combining visible-light-driven photocatalysis with cyclohexanone monooxygenase (CHMO) whole-cell biocatalysis. Two available photocatalysts, Au-doped TiO2 (Au-TiO2 ) and graphitic carbonitride (g-C3 N4 ), were evaluated in the experiment and some optimisations to the cascade reaction were applied. In stepwise mode, the highest degree of conversion from cyclohexanol to ϵ-caprolactone can be up to 41 %, with use of g-C3 N4 . The cascade reaction from cyclohexane to ϵ-caprolactone is achievable under a light intensity of 149 µW cm-2 .

Photonic crystal-enhanced fluorescence biosensor with logic gate operation based on one-pot cascade amplification DNA circuit for enzyme-free and ultrasensitive analysis of two microRNAs.

The development of sensitive and efficient analytical methods for multiple biomarkers is crucial for cancer screening at early stage. MicroRNAs (miRNAs) are a kind of biomarkers with diagnostic potential for cancer. However, the ultrasensitive and logical analysis of multiple miRNAs with simple operation still faces some challenges. Herein, a photonic crystal (PC)-enhanced fluorescence biosensor with logic gate operation based on one-pot cascade amplification DNA circuit was developed for enzyme-free and ultrasensitive analysis of two cancer-related miRNAs. The fluorescence biosensor was performed by biochemical recognition amplification module (BCRAM) and physical enhancement module (PEM) to achieve logical and sensitive detection. In the BCRAM, one-pot cascade amplification circuit consisted of the upstream parallel entropy-driven circuit (EDC) and the downstream shared catalytic hairpin assembly (CHA). The input of target miRNA would trigger each corresponding EDC, and the parallel EDCs released the same R strand for triggering subsequent CHA; thus, the OR logic gate was obtained with minimization of design and operation. In the PEM, photonic crystal (PC) array was prepared easily for specifically enhancing the fluorescence output from BCRAM by the optical modulation capabilities; meanwhile, the high-throughput signal readout was achieved by microplate analyzer. Benefiting from the integrated advantages of two modules, the proposed biosensor achieved ultrasensitive detection of two miRNAs with easy logic gate operation, obtaining the LODs of 8.6 fM and 6.7 fM under isothermal and enzyme-free conditions. Hence, the biosensor has the advantages of high sensitivity, easy operation, multiplex and high-throughput analysis, showing great potential for cancer screening at early stage.

Synthesis, crystal structure, and photoluminescent properties of ternary Cd(II)/triazolate/chloride system.

Solvothermal reactions of cadmium chloride and 1,2,4-triazole (Htrz) in different solvent mediums have successfully synthesized five ternary Cd(II)/trz/Cl(-) complexes, [Cd(trz)Cl]·H(2)O (1·H(2)O), [Cd(4)(trz)(5)Cl(3)(H(2)O)]·(THF)(1.25)·(H(2)O)(2.5) (2·1.25THF·2.5H(2)O), [Cd(3)(trz)(2)Cl(MeCN)] (3), [Cd(3)(trz)(4)Cl(2)]·(H(2)O)(0.5) (4·0.5H(2)O), and [Cd(4)(trz)(6)Cl(2)(H(2)O)(0.5)]·(H(2)O)(3.5) (5·3.5H(2)O). All of these five coordination polymers have three-dimensional (3-D) structural features, which are constructed by distinct substructures including clusters, chains, rings, and even 3-D frameworks. In all cases, 1,2,4-triazolate adopts a µ(1,2,4) bridging mode, and chloride ions display a µ(2), µ(3), µ(4) bridging mode, respectively, which makes the structural diversity in the assembling system, for example, µ(4)-Cl and cadmium triazolate, build up an unprecedented tetranuclear cluster [Cd(4)(trz)(8)Cl](-) in 2. All of the materials exhibit intense blue fluorescent emission and high thermal stability, wherein 1 presents an interesting guest-responsive photoluminescent property.

[Determination of mercury by electric heat digestion and atomic fluorescence spectrometry].

OBJECTIVE: To develop a method to determine mercury by electric heat digestion and atomic fluorescence spectrometry. METHODS: After electric heat digestion using aqua regia, the soil samples were determined by atomic fluorescence spectrometry. RESULTS: The linear range of the method was from 0 to 50 microg/L. The correlation coefficient was 0.9994. The detection limit of the method was 0.0051 microg/L. The relative standard deviations ranged from 1.55% to 6.52%. Four soil samples for quality control were determined by this method and all of the results were in the range of the true values. CONCLUSION: The optimized method have many advantages, such as high sensitivity, few interferences, wide linearity. At the same time,it is simple and rapid.

Enantioselective Sulfoxidation of Thioanisole by Cascading a Choline Oxidase and a Peroxygenase in the Presence of Natural Deep Eutectic Solvents.

A bienzymatic cascade for selective sulfoxidation is presented. The evolved recombinant peroxygenase from Agrocybe aegeritra catalyses the enantioselective sulfoxidation of thioanisole whereas the choline oxidase from Arthrobacter nicotianae provides the H2 O2 necessary via reductive activation of ambient oxygen. The reactions are performed in choline chloride-based deep eutectic solvents serving as co-solvent and stoichiometric reductant at the same time. Very promising product concentrations (up to 15 mM enantiopure sulfoxide) and catalyst performances (turnover numbers of 150,000 and 2100 for the peroxygenase and oxidase, respectively) have been achieved.

[Study on polymorphism of UCP2 gene in Chengdu simple obesity and normal-weight people and a preliminary investigation of its relationship with gut bacteria].

OBJECTIVE: To study on the polymorphism of UCP2 gene in Chengdu simple obesity and normal-weight people and to initially investigate the relationship between UCP2 Ala55Val variation and gut bacteria. METHODS: PCR-PFLP was applied to determine the genotypes of Ala55Val variant in the UCP2 gene of 86 Chengdu people (the simple obesity group, 43 subjects; the normal-weight group, 43 subjects). And six kinds of gut bacteria among different genotypes in different groups were analyzed. RESULTS: Both the simple obesity and the normal-weight group had the Ala55Val variants of Ala/Ala, Val/Val and Ala/Val in the UCP2 gene, and the Ala55Val genotype distributions between the two groups was significantly different (chi2=11.97, P< 0.05). The allelic mutation frequency in the simple obesity group was higher than that of the normal-weight group (chi2=10.06, P<0.05). However, no significant difference was observed in the population of six gut bacteria among different genotypes in different groups (P>0.05). CONCLUSION: The UCP2 gene mutation might be a risk factor of obesity in Chengdu area. However, this gene mutation may not be an impact factor on the alternation of gut bacteria.

Oxidation degree of soybean oil at induction time point under Rancimat test condition: Theoretical derivation and experimental observation.

Indices including conductivity, short-chain carboxylic acids, total polar material, acid value, peroxide value and fatty acid composition in water or oil were monitored during Rancimat test of soybean oil from 90 °C to 120 °C. Formic, acetic, propionic and butyric acids in water were detected by ion chromatography. The results showed that all indices had two-stage oxidation rates of initiation (ki) and propagation (kp) at each temperature. Induction period (IP) computed from conductivity and other indices were well correlated (R2 = 0.9980-0.9999). According to the Arrhenius model and empirical equation, ki increased exponentially with temperature (T) while IP decreased exponentially with T. Oxidation degree of oil at induction time point IP*ki was found to be independent of heating time and temperature. The transition between two models was theoretically derived and proved by H NMR. Evaluation of IP*ki may provide a new route to correlate Rancimat data with shelf life of edible oil.

Natural Deep Eutectic Solvents as Multifunctional Media for the Valorization of Agricultural Wastes.

The use of natural deep eutectic solvents (NADES) as multifunctional solvents for limonene bioprocessing was reported. NADES were used for the extraction of limonene from orange peel wastes, as solvent for the chemoenzymatic epoxidation of limonene, and as sacrificial electron donor for the in situ generation of H2 O2 to promote the epoxidation reaction. The proof-of-concept for this multifunctional use was provided, and the scope and current limitations of the concept were outlined.

Simultaneous Detection of Yersinia Enterocolitica and Listeria Monocytogenes in Foodstuffs by Capillary Electrophoresis and Microchip Capillary Electrophoresis Laser-Induced Fluorescence Detector.

Background: Food safety is one of the most important public health problems in the world, and pathogenic bacterium is a major factor causing serious foodborne diseases. Objective: Two methods of duplex PCR combined with capillary electrophoresis laser-induced fluorescence detector (CE-LIF) and microchip capillary electrophoresis laser-induced fluorescence detector (MCE-LIF) have been developed for the simultaneous detection of Yersinia Enterocolitica and Listeria Monocytogenes in various foods. The specific conservative sequences of these two bacteria were amplified. Methods: After labelled with nucleic acid dye SYBR Gold and SYBR Orange, the PCR products were analyzed by CE-LIF and MCE-LIF, respectively. Under the optimal conditions, the detection of PCR products of the target bacteria was achieved in less than 15 min by CE-LIF and within 6 min by MCE-LIF. Results: The alignment analysis demonstrated that the PCR products had good agreement with the sequences published in GenBank. The CE-LIF method could detect 10 CFU/mL Y. enterocolitica and L. monocytogenes, and the MCE-LIF method could detect 100 CFU/mL Y. enterocolitica and L. monocytogenes. The intraday precisions of migration time and peak area of DNA markers and PCR products were in the range of 1.13 to 1.18% and 1.60 to 6.29%, respectively, for CE-LIF and 1.18 to 1.48% and 2.85 to 4.06%, respectively, for MCE-LIF. Conclusions: The proposed methods could be applied to target bacterial detection infood samples rapidly, sensitively, and specifically. Highlights: Two new methods based on CE and MCE have been developed for the simultaneous detection of Y. enterocolitica and L. monocytogenes in foodstuffs, and they can detect the bacteria directly without any enrichment because of their high sensitivity.

Interaction between serotonin transporter gene-linked polymorphic region (5-HTTLPR) and job-related stress in insomnia: a cross-sectional study in Sichuan, China.

OBJECTIVE: Insomnia, a widely occurring sleep disorder in modern society, has a large impact on life quality and work safety. A cross-sectional study was conducted to explore the possible link between serotonin transporter-linked polymorphic region (5-HTTLPR), job-related stress, and insomnia in West China. METHODS: Of the total 462 workers recruited, 177 had insomnia according to the Athens Insomnia Scale (AIS-5). The 5-HTTLPR genotypes were determined by polymerase chain reaction. Job-related stress was assessed for each participant by the General Job Stress Questionnaire. RESULTS: Unconditional logistic regression models showed that the 5-HTTLPR genotype was significantly associated with insomnia, and >80% increased risk per S allele was observed. High job-related stress had a higher risk for insomnia than low job-related stress (odds ratio [OR], 6.14; 95% confidence interval [CI], 3.94-9.59). Crossover analysis found significant job-related stress × 5-HTTLPR interaction. Compared to individuals with both low job-related stress and SL/LL genotype, those with both higher job-related stress and SS genotype had a higher risk of insomnia (OR, 5.16; 95% CI, 3.13-8.54), whereas those with both low job-related stress and SS genotype showed a lower risk of insomnia (OR, 0.26; 95% CI, 0.08-0.74). The interaction remained statistically significant after adjusting for potential confounding factors. CONCLUSIONS: The findings indicated that 5-HTTLPR could modify the effect of job-related stress on employees' insomnia, suggesting that a work environment-based personalized intervention may be applied to prevent employees' insomnia by alleviating job-related stress in the workplace.

Gut bacteria alteration in obese people and its relationship with gene polymorphism.

AIM: To investigate the differences in cultivable gut bacteria and peroxisome proliferator-activated receptor γ2 (PPAR-γ2) gene Pro12Ala variation in obese and normal-weight Chinese people. METHODS: Using culture methods, the amounts of Escherichia coli, Enterococci, Bacteroides, Lactobacilli, Bifidobacteria and Clostridium perfringens (C. perfringens) in the feces of 52 obese participants [body mass index (BMI): ≥ 28 kg/m(2)] and 52 participants of normal-weight (BMI: 18.5-24 kg/m(2)) were obtained. Study participants completed comprehensive questionnaires and underwent clinical laboratory tests. The polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) assay was used to analyze PPAR-γ2 gene Pro12Ala variation. RESULTS: The obese group exhibited a lower amount of C. perfringens (6.54 ± 0.65 vs 6.94 ± 0.57, P = 0.001) and Bacteroides (9.81 ± 0.58 vs 10.06 ± 0.39, P = 0.012) than their normal-weight counterparts. No major differences were observed in Pro12Ala genotype distribution between the two groups; however, obese individuals with a Pro/Ala genotype had a significantly lower level of Bacteroides (9.45 ± 0.62 vs 9.93 ± 0.51, P = 0.027) than those with a Pro/Pro genotype. In addition, the obese group demonstrated a higher stool frequency (U = 975, P < 0.001) and a looser stool (U = 1062, P = 0.015) than the normal-weight group. CONCLUSION: Our results indicated interactions among cultivable gut flora, host genetic factors and obese phenotype and this might be helpful for obesity prevention.