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1.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-692337

RESUMO

A novel method for rapid detection of arginine based on fluorescence resonance energy transfer effect (FRET) between carbon quantum dots ( CQDs) and gold nanoparticles ( AuNPs) was developed. Firstly, the CQDs with excellent fluorescence properties were synthesized by one-step microwave assisted method. The AuNPs/ CQDs composites were characterized and their quenching mechanism was analyzed. Then the amount of AuNPs/ CQDs, the pH value and the reaction time were optimal. Under the optimum conditions, the fluorescence system was used to detect the content of arginine, showing a good linear relationship ( R2 = 0. 993 ) between fluorescence intensity and concentration of arginine in the range of 0. 1-10. 0 μmol/ L, and the detection limit was 5. 8 nmol/ L. Finally, the content of arginine in grape juice was determined by this method with recoveries of 105. 4% -110. 8% , which indicated that the proposed FRET system had the potential for practical detection of arginine in fruit juice.

2.
Food Chem ; 197(Pt A): 930-6, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26617036

RESUMO

Trimethylamine (TMA) is a key measurement indicator for meat spoilage. In order to develop simple, cheap, and sensitive sensors for TMA detection, a nanoporous colorimetric sensor array (NCSA) was developed. A sol-gel method has been used to obtain TiO2 nanoporous film as substrate material to improve the sensitivity and stability of the CSA. The sensor enabled the visual detection of TMA gas from the permissible exposure limits (PEL) 10 ppm to 60 ppb concentrations with significant response. Principal component analysis (PCA) was used to characterize the functional relationship between the color difference data and TMA concentrations. Furthermore, the NCSA was used to predict the presence of TMA in Yao-meat. A partial least square (PLS) prediction model was obtained with the correlation coefficients of 0.896 and 0.837 in calibration and prediction sets, respectively. This research suggested that the NCSA offers a useful technology for quality evaluation of TMA in meat.


Assuntos
Colorimetria/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Carne/análise , Metilaminas/análise , Nanoporos , Titânio/química , Análise dos Mínimos Quadrados , Limite de Detecção , Modelos Teóricos , Análise de Componente Principal
3.
Biosens Bioelectron ; 67: 35-41, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24934102

RESUMO

A new room temperature gas sensor was fabricated with pigment-sensitized TiO2 thin film as the sensing layer. Four natural pigments were extracted from spinach (Spinacia oleracea), red radish (Raphanus sativus L), winter jasmine (Jasminum nudiflorum), and black rice (Oryza sativa L. indica) by ethanol. Natural pigment-sensitized TiO2 sensor was prepared by immersing porous TiO2 films in an ethanol solution containing a natural pigment for 24h. The hybrid organic-inorganic formed films here were firstly exposed to atmospheres containing methylamine vapours with concentrations over the range 2-10 ppm at room temperature. The films sensitized by the pigments from black-rice showed an excellent gas-sensitivity to methylamine among the four natural pigments sensitized films due to the anthocyanins. The relative change resistance, S, of the films increased almost linearly with increasing concentrations of methylamine (r=0.931). At last, the black rice pigment sensitized TiO2 thin film was used to determine the biogenic amines generated by pork during storage. The developed films had good sensitivity to analogous gases such as putrscine, and cadaverine that will increase during storage.


Assuntos
Aminas Biogênicas/isolamento & purificação , Técnicas Biossensoriais , Análise de Alimentos , Gases/isolamento & purificação , Animais , Antocianinas/química , Aminas Biogênicas/química , Gases/química , Carne , Suínos , Temperatura , Titânio/química
4.
Food Chem ; 138(1): 192-9, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23265476

RESUMO

More than 3.2 million litres of vinegar is consumed every day in China. There are many types of vinegar in China. How to control the quality of vinegar is problem. Near infrared spectroscopy (NIR) transmission technique was applied to achieve this purpose. Ninety-five vinegar samples from 14 origins covering 11 provinces in China were collected. They were classified into mature vinegar, aromatic vinegar, rice vinegar, fruit vinegar, and white vinegar. Fruit vinegar and white vinegar were separated from the other traditional categories in the two-dimension principal component space of NIR after principle component analysis (PCA). Least-squares support vector machine (LS-SVM) as the pattern recognition was firstly applied to identify mature vinegar, aromatic vinegar, rice vinegar in this study. The top two principal components (PCs) were extracted as the input of LS-SVM classifiers by principal component analysis (PCA). The best experimental results were obtained using the radial basis function (RBF) LS-SVM classifier with σ=0.8. The accuracies of identification were more than 85% for three traditional vinegar categories. Compared with the back propagation artificial neural network (BP-ANN) approach, LS-SVM algorithm showed its excellent generalisation for identification results. As total acid content (TAC) is highly connecting with the quality of vinegar, NIR was used to prediction the TAC of samples. LS-SVM was applied to building the TAC prediction model based on spectral transmission rate. Compared with partial least-square (PLS) model, LS-SVM model gave better precision and accuracy in predicting TAC. The determination coefficient for prediction (R(p)) of the LS-SVM model was 0.919 and root mean square error for prediction (RMSEP) was 0.3226. This work demonstrated that near infrared spectroscopy technique coupled with LS-SVM could be used as a quality control method for vinegar.


Assuntos
Ácido Acético/química , Ácidos/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , China , Análise dos Mínimos Quadrados , Análise de Componente Principal , Controle de Qualidade , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Máquina de Vetores de Suporte
5.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-973846

RESUMO

@#ObjectiveTo study the effects of Deanxit associated with illumination on the depressed patients with chronic pain in open psychology ward in general hospitals.Methods41 patients were assigned into two groups:study group included 21 patients,who received the treatment of Deanxit(1 mg/d),even more with the treatment of illumination;control group included 20 patients,who only received the treatment of Deanxit(1 mg/d).Assessments of the efficacy were performed with Beck depression inventory(BDI) and Hamilton depression scale(HAMD) before and in the 2nd,4th,8th week during treatment.In addition,Symptom Checklist-90(SCL-90) was also used before and after treatment,as well as six month after discharge.ResultsThe efficacy was consistent with study group's superiority versus control group.ConclusionThe treatment consisting of Deanxit associated with illumination is effective on depression and helpful to prevent relapsing.

6.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-978010

RESUMO

@#ObjectiveTo observe the effect of light therapy combined with fluoxetine on winter attack depression.Methods68 patients of winter attack depression were divided randomly into the treatment group and control group with 34 cases in each group. Patients of the treatment group were treated by bright white light combined with fluoxetine (20 mg/d), but cases of the control group were treated only with fluoxetine. Therapeutic effects of two groups were evaluated with BDI, HAMD, and SCL-90 scales and traditional evaluation.ResultsPatients of the treatment group had a better effect than that of the control group (P<0.05).ConclusionLight therapy combined with fluoxetine has a good short and long term effect on winter attack depression, and can prevent from recurrence.

7.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-978607

RESUMO

@#ObjectiveTo explore the possibility and significance that psychotic patients treated in open wards in general hospital,a new managing model for psychosis cases.Methods1 200 psychotic cases were treated in the open ward,that was a new managing model for psychotic patients.ResultsNew managing model had following advantages: a. free for patients to communicate with outsides and keep their secret and human rights; b. having better effective,shorter housing days,and more economy compared with controlled cases.ConclusionSetting up open managing psychosis wards in general hospital can help treatment of psychotic patients,and it is the tendency of modern mental health.

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