A new polyketide from marine-derived Streptomyces sp.MDW-06 / 中国中药杂志

To isolate and identify secondary metabolites of marine-derived Streptomyces sp.MDW-06,the isolations and purifications of compounds were performed by means of column chromatography over silica gel. And their structures were elucidated through the spectroscopic analysis of MS,NMR and specific rotations. The bioactivities were assayed by paper diffusion and DPPH method. From the fermentation broth of marine-derived Streptomyces sp.MDW-06,five compounds( 1-5) were isolated and identified as streptopentanoic acid( 1),germicidin A( 2),germicidin B( 3),isogermicidin A( 4),isogermicidin B( 5) and oxohygrolidin( 6),respectively. Compound 1 is a new compound. Compound 1 shows DPPH radical scavenging activity with 36. 4% at 100 mg·L~(-1).

A Photoelecteochemical Sensor Based on CdS Sensitized Fe:TiO2Nanosheets for Determination of Cu2+ / 分析化学

Iron-doped titanium dioxide nanosheets was prepared by hydrothermal method using tetrabutyl titanate (C16H36O4Ti) and iron trifluoride (FeF3) and modified on ITO electrode.ITO/Fe : TiO2/CdS photoelectrochemical sensor was fabricated by successive ionic layer absorption and reaction(SILAR) method for determination of copper ion.The band gap of electode material was narrowed by iron doped TiO2 nanosheets,which made its absorption red-shifted and its response range of light was magnified.Based on the sensitization effect of CdS,the absorption and utilization of visible light of sensor was significantly enhanced and the photoelectric signal was amplified via reducing the recombination of electrons and holes.The sensor displayed excellent analytical performance for detection of copper ion with linear range of 0.2-4.0 μmol/L and 4.0-80.0 μmol/L and with the detection limit of 85 nmol/L.The sensor was used to detect copper ion in tap water,drinking water and Yongjiang river water with recoveries ranging from 94% to 111%.

Structural and functional insights into lipid-bound nerve growth factors.

Nerve growth factor (NGF) is a dimeric molecule that modulates the survival, proliferation, and differentiation of nervous cells and is also known to act on cells of the immune system and endocrine system. NGFs extracted from mouse submaxillary gland and cobra venom have different immunological behaviors, yet the underlying mechanism remains unclear. Here we report the crystal structure of the NGF purified from Chinese cobra Naja naja atra (cNGF), which unexpectedly reveals a 2-tailed lipid molecule that is embedded between the two protomers of the NGF homodimer. In addition, crystallographic analysis indicated that the purified mouse NGF(mNGF) is free from lipid but can bind lysophosphatidylserine (lyso-PS) in the same pocket as cNGF. Bioassays indicated that the binding of lipid molecules to cNGF and mNGF are essential for their mast cell activation activity and abates their p75(NTR) binding capacity. Taken together, these results suggest a new mechanism for the regulation of the function of NGF.

Relationship between caregivers' nutritional knowledge and children's dietary behavior in Chinese rural areas / 中南大学学报(医学版)

OBJECTIVE@#To explore the relationship between caregivers' nutritional knowledge and children's dietary behavior in rural areas of China.@*METHODS@#A cross-sectional study was conducted. 3361 rural caregivers and their children, aged 2 to 7 years old, were selected randomly and surveyed by questionnaire. Logistic regression models were used to identify the relationship between caregivers' nutritional knowledge and the children's dietary behaviors.@*RESULTS@#The awareness level of nutritional knowledge among rural caregivers was 57.9%; among the children surveyed, 79.6% did not like to drink milk, 66.0% were considered choosy of food, 84.1% regularly snacked, 24.4% frequently skipped breakfast, and 13.7% did not come to meals on time. Logistic regression models indicated that a caregiver with a low level of nutritional knowledge is a risk factor for a child's unhealth dietary behaviors (snacking excepted): the odds ratios (OR) of not liking to drink milk, being choosy about food, skipping breakfast or not having meals on time are 1.665, 1.338, 1.330 and 1.582, respectively.@*CONCLUSION@#Caregivers' nutritional knowledge is strongly associated with children's dietary behavior. Nutrition education programs are urgently wanted to improve caregiver's knowledge and thus to improve children's dietary behavior in rural areas of China.

Knowledge, attitude, practice and related determinants on nutrition among caregivers of rural stranded children under 7-year-olds in China / 中华流行病学杂志

Objective To explore knowledge, attitude, practice (KAP) and related determinants on nutrition among caregivers of those rural stranded children under 7 years of age in China and to provide evidence for setting up relevant health education program. Methods 1691 caregivers of the stranded children randomly selected were surveyed by a standard questionnaire. Logistic regression models were used to screen the determinants on KAP regarding nutrition. Results Rates on awareness, positive attitude and approprite behavior were lower in caregivers of children whose parents both left (47.8%, 55.4%, 41.8%, respectively) the countryside, when compared with those only one parent was away from home (59.9%, 59.5%, 38.0%, respectively). Data from multivariable logistic regression models showed that caregivers' KAP on nutrition was related to age, educational background, average family income, and willingness on the job as well as the age of the child. Conclusion Improving caregivers' KAP on nutrition and setting up appropriate health education program were in urgent need.

[Quantitative detection of Vibrio parahaemolyticus by real-time TaqMan PCR].

Vibrio parahaemolyticus is one of important human food pathogens. Traditional diagnostic tests for V. parahaemolyticus are laborious and always present false negative results. Therefore, it is important to develop a nucleic acid-based test for quantitative detection of V. parahaemolyticus. A TaqMan PCR assay was presented for quantitative detection of V. parahaemolyticus in pure cultures and oysters. The primers and probe were designed according to the gyrase B gene (gyrB) sequence of V. parahaemolyticus strains. Amplification of DNAs from 12 bacterial strains comprising 9 genera showed that all of the strains of V. parahaemolyticus tested (n = 4) were positive and all other species of strains tested (n = 8) were negative. The results of the TaqMan PCR with raw oysters inoculated with V. parahaemolyticus were comparable to those of pure cultures. The sensitivity of the assay was 1 CFU PCR Mixture(-1) and 10 CFU PCR Mixture(-1) in pure culture and inoculated raw oyster, respectively. The correlation rate was 0.99 (gamma2 = 0.99). The assay could be completed within 1h. The Real-time PCR can be used as a rapid screening tool for the presence of V. parahaemolyticus in seafood without prior isolation and characterization of the bacteria by traditional microbiological methods.

Behavior and Exposure to Violence:Mediating Role of Self-esteem in Rural Middle School Students / 中国临床心理学杂志

Objective:To test a model in which self-esteem mediated the effects of behavior on exposure to violence(victimization) in a sample of rural middle school students.Methods:A cross-section study was conducted in 3620 middle school students randomly selected from rural areas.A questionnaire of violence(WHO) and Achenbach Children Behavior Checklist(CBCL) and Rosenberg self-esteem scale were used to measure the exposure to violence behavior,and self-esteem respectively.Results:Hierarchical regression analyses provided evidence that the addition of self-esteem reduced the links between behavior and exposure to violence(? from 0.232 to 0.226).Sobel Z-test predicted that self-esteem partially mediated the effects of behavior on exposure to violence(victimization) with significant difference(? from 0.232 to 0.226,Sobel-Z value=2.340,P=0.019).Speech violence,physical violence,and sexual violence were tested by the same model respectively,and the results showed that self-esteem partially mediated the effects of behavior on speech violence with significant difference(? from 0.225 to 0.200,Sobel-Z value=1.992,P=0.046),but not on physical or sexual violence.Conclusion:Self-esteem partially mediates the effects of behavior on exposure to violence(emotion violence).