[Detection of Late Blight Disease on Potato Leaves Using Hyperspectral Imaging Technique].

Hyperspectral imaging feature on potato leaves stressed by late blight was studied in the present paper. The experiment used 60 potato leaves. Among those 60 potato leaves, 48 leaves were vitro inoculated with pathogen of potato late blight, the rest 12 leaves were used as control samples. The leaves were observed for 7 continuous days before and after inoculated and samples including healthy and infested were acquired. Hyperspectral data of healthy and infected potato samples of different disease severity were obtained by the hyperspectral imaging system from 374 to 1,018 nm and then extract spectral data of region of interest (ROI) from those hyperspectral data by the ENVI software. In order to improve the signal-to-noise ratio, the spectral data were preprocessed using different pretreatment methods such as moving average smoothing, normalization, derivative, baseline etc. The least squares-support vector machine(LS-SVM) models were developed based on the raw and those preprocessed data. Among the nine models, the model that used the raw data and the data after the spectroscopic transformation performed best with the discrimination of 94.87%. It was demonstrated that it is realized to determine the potato late blight disease of different disease severity using hyperspectral imaging technique.

[Kinetic models for determination of yeast in fresh jujube using near infrared spectroscopy].

The objectives of this study were: (1) to optimize a near-infrared (NIR) spectroscopy model for fresh jujube stored at room temperature to predict the quality change (yeast growth), (2) to establish a kinetic model of yeast growth for fresh jujubes at room temperature according to NIR spectroscopy data and storage time, and (3) to predict the shelf life of fresh jujube at room temperature. The Lizao samples of fresh jujubes were adopted as the research object in the study. The NIR spectral data were achieved before yeast infection level measured. In order to optimize the NIR model, the pretreatment techniques such as Savitzky-Golay smoothing (S-G smoothing), multiplicative scatter correction (MSC), first derivative (1-Der) and second derivative (2-Der) were compared with the raw spectra by using a statistical software package (Unscrambler 9.8), and the regression coefficient (RC) method was used to choose the characteristic wavenumber. Multiple linear regression (MLR) was applied as NIR modeling method. According to the predicted yeast infection level using NIR model, the chemical kinetic models of spectral data and storage time at room temperature with zero-order and first-order reaction were established by using a statistical software package (SPSS 18). The shelf life could be predicted based on the chemical kinetic model. The results showed that the characteristic wave numbers of 10 300, 8 330, 6 900, 5 666, 5 150 and 4 060 cm(-1) in the whole near-infrared range with MSC technique could be chosen to model the quality deterioration of fresh jujube at room temperature. The NIR model that produced the best prediction had the form of B = 320.027 - 233.920(chi1) - 206.663(chi2) - 61.584(chi3) - 14.847(chi4) - 2.680(chi5) - 9.131(chi6), where B is yeast value (lg/cfu x g(-1)), chi1-chi6 are absorbance value of characteristic wavenumber. The correlation coefficient of calibration (R(c)) was 0.950, the root mean square error of calibration (RMSEC) was 2. 560, the correlation coefficient of prediction (R(p)) was 0.863, and the root mean square error of prediction (RMSEP) was 2.447. The zero-order reaction kinetic model performed better than the first-order model. The zero-order reaction kinetic model of yeast growth with storage time was predicted by B(t) = 171.395-124.445(chi1) - 109.945(chi2) - 32.763(chi3) - 7.899(chi4) - 1.426(chi5) - 4.857(chi6) + 0.045t with a correlation coefficient of 0.996. Based on the linear correlation between the NIR measurement and storage time, the shelf life of fresh jujube at room temperature was predicted to be 8 days for the yeast infection level less than 10 cfu x g(-1). The study showed that the NIR when combed with kinetic models could be used as a non-destructive, rapid method to detect the yeast growth in fresh jujube, and to predict the shelf life and ensure the quality and safety of fresh jujube.

[Discrimination of the fresh jujube varieties and dehiscent fruit by NIR spectroscopy].

There are many fresh jujube varieties. The different variety has different quality. In addition, dehiscent fruit easily rot and the rotten fruit contaminated the full fruit very rapidly. It is necessary to discriminate the jujube varieties and dehiscent fruit to reduce the storage loss. The objective is to discriminate varieties and dehiscent Fruit of fresh jujube using near infrared (NIR) spectroscopy. Two jujube varieties were investigated. Smoothing, multiplicative scatter correction, the first derivative and second derivative methods were adopted to pretreat the spectra. The regression coefficient and principal component analysis were used to select wavenumber. Multilayer perceptron artificial neural network was used to build varieties and dehiscent fruit qualitative discrimination model. The results showed that the varieties and dehiscent fruit could be correctly discriminated and both the discrimination accuracy rates were 100%. Hence, near infrared spectroscopy could achieve to identify the variety of Dongzao and Lizao, and dehiscent fruit and intact fruit.

Study on the roles of ß-catenin in hydrogen peroxide-induced senescence in human skin fibroblasts.

Oxidative stress is one of the most important causes of the cellular senescence process. Previous studies showed that ß-catenin can regulate FoxO3a and this association was enhanced in cells exposed to oxidative stress. It has also been reported that ß-catenin can regulate some senescence-related proteins. We propose that ß-catenin may play a crucial role in senescence of normal human primary skin fibroblasts (NHSFs). Here, we explored the roles and mechanisms of ß-catenin on H(2)O(2)-induced senescence in NHSFs. ß-catenin expression was decreased in NHSFs after H(2)O(2) treatment. Overexpression of ß-catenin in NHSFs led to a marked delay of many senescent phenotypes induced by H(2)O(2). Furthermore, overexpression of ß-catenin in NHSFs can antagonise the alteration of reactive oxygen species accumulation and some senescence-related proteins expression induced by H(2)O(2) treatment. Our data demonstrated that ß-catenin can protect NHSFs from H(2)O(2)-induced premature senescence by alleviating oxidative stress and regulating some senescence-related molecules.

Association study of tumor necrosis factor receptor type 2 M196R and toll-like receptor 2 Arg753Gln polymorphisms with acne vulgaris in a Chinese Han ethnic group.

BACKGROUND: Inflammatory cytokines such as tumor necrosis factor receptor 2 (TNFR2) and Toll-like receptor 2 (TLR2) are the main responsible mediators of inflammatory acne. Factors affecting their production may possibly influence the degree of inflammatory response and hence may account for the clinical severity of acne. However, the roles of TNFR2 and TLR2 in the pathophysiology of acne vulgaris are poorly understood. We therefore investigated the relationship between acne vulgaris susceptibility and the polymorphisms in the TNFR2 M196R as well as TLR2 Arg753Gln gene. METHODS: A total of 93 acne vulgaris patients and 90 healthy subjects from the Chinese Han ethnic group were enrolled in the study. The polymerase chain reaction restriction fragment length polymorphism technique was adopted to analyze the single-nucleotide polymorphisms of the TNFR2 M196R and TLR2 Arg753Gln gene, and to examine the association between acne vulgaris and the polymorphisms in the TNFR2 M196R as well as TLR2 Arg753Gln gene. The relationship between different genotypes and the susceptibility to acne vulgaris was analyzed. RESULTS: There is a significant difference in the frequency of TNFR2 M196R genetic polymorphisms between the moderate-acne to severe-acne subgroups and the control group (p < 0.05), and there is also a significant difference in the frequency of TLR2 Arg753Gln genetic polymorphisms between the severe-acne subgroup and control group (p < 0.05). CONCLUSION: The 196R allele of TNFR2 M196R as well as the 753Gln allele of TLR2 Arg753Gln are risk factors for acne vulgaris in Chinese Han patients, further supporting the contribution of inflammatory cytokines to the pathogenesis of acne.

[Measurement of cooking loss and tenderness of fresh pork using visible/near infrared spectroscopy].

Cooking loss and tenderness are important quality characteristics of fresh pork. To find a rapid, non-destructive and non-contaminated method to measure them, visible/near infrared spectroscopy was proposed for measurement of cooking loss and tenderness of vacuum-packed pork loin. The acquired raw spectra were pretreated by Savisky-Golay smoothing, second derivative and MSC, respectively using the software of Unscrambler 9.6. A total of 104 samples were used in the experiment. The samples were divided into calibration set and validation set. The calibration set was used to set up calibration model and then the model was adopted to predict the samples of validation set. The partial least square regression (PLSR) was used to build calibration model. The results show that the correlation coefficient for cooking loss and shear force are 0.81 and 0.78 respectively. It is feasible and effective that measure cooking loss and shear force of vacuum-packed fresh pork loin using visible/near infrared spectroscopy in interactance mode.

[Detection of fatty acid composition in intramuscular fat of packed pork loin by near infrared spectroscopy].

Near infrared spectroscopy as a new method was proposed for rapid and non-destructive measurement of fatty acid composition in intramuscular fat of packed pork loin. Gas chromatography was used as a reference method for the spectral analysis of fatty acid composition. The fiber optic in interactance mode was adopted to measure the spectra of packed pork loins by low density polythene. The original spectra were pretreated by smoothing and 2nd derivative, and then PLS calibration model was builtby using software of Unscrambler 9.6. A total of eighty two samples were used in the experiment. The samples were divided into calibration set and validation set after removing the outliers. The calibration set was used to set up calibration model and then the model was adopted to predict the samples of validation set. The results show that the correlation coefficient for C14 : 0, C15 : 1, C16 : 0, C16 : 1, C18 : 0, C18 : 1, C18 : 2, C18 : 3, C20 : 1, C20 : 4, SFA, MUFA, PUFA is 0.57, 0.76, 0.71, 0.77, 0.62, 0.81, 0.86, 0.91, 0.85, 0.91, 0.67, 0.81 and 0.95, respectively. It means that evaluating fatty acid using near infrared spectroscopy in interactance mode has higher precision. Near infrared spectroscopy technique is a feasible and rapid method for nondestructive detection of fatty acid composition in intramuscular fat of packed pork loin.

[Prediction of water holding capacity of fresh pork using near infrared spectroscopy].

Water holding capacity (WHC) is an important quality characteristic of fresh pork. It is necessary to determinate it by a rapid and nondestructive method in order to reduce the loss of meat. Near infrared spectroscopy as a new method was proposed for rapid and nondestructive measurement of WHC of vacuum-packed pork loin. Two reference methods for measuring water holding capacity were used to evaluate the water holding capacity, i. e. drip loss and press method. The acquired raw spectra were pretreated by Savisky-Golay smoothing and second derivative, respectively. A total of 106 samples were used in the experiment. The samples were divided into calibration set and validation set. The calibration set was used to set up calibration model and then the model was adopted to predict the samples of validation set. The partial least square regression (PLSR) was used to build calibration model. The results show that the correlation coefficient for drip loss and press method is 0.74-0.79. It shows that evaluating the water holding capacity of vacuum-packed fresh pork loin using near infrared spectroscopy in diffuse reflection mode is better than those results with reflectance or transmission.

[Correlation between CYP17 gene polymorphisms and female post adolescent acne in Han population in Hunan Province].

OBJECTIVE: To explore the correlation between androgen-related CYP17 gene polymorphisms and female post adolescent acne in Han population in Hunan Province. METHODS: The female patients with post adolescent acne and high levels of androgen (A group), those without high levels of androgen (B group) and healthy subjects (C group) were enrolled. The CYP17 gene polymorphism was investigated by PCR using DNA samples from peripheral blood lymphocytes. The T-->C transition in the risk allele (A2) produced a new recognition site for the restriction endonuclease MspA1 I. Three genotypes of androgen-related CYP17 gene (A1A1, A1A2, and A2A2) were determined and confirmed by sequencing. RESULTS: The frequency of the A1A2 gene was similar in the cases and controls (P>0.05). The frequency of A2A2 gene was not significantly different between groups A and C (P>0.05). The frequency of A2A2 gene was significantly different between groups A and B and between groups B and C (P<0.05). CONCLUSION: The presence of base substitution in androgen-related CYP17 gene at -34 bp (T-->C) increases the risk of post adolescent acne in female subjects with increased androgen levels.