Applied Mechanics and Materials Vols. 651-653

Abstract: The QTLs associated with cassava yield traits were detected by two-QTL model (unconditional and conditional QTLs) approaches after planting for 90 d, 180 d and 270 d in the present study. A genetic linkage map was constructed with a segregating F₁ population derived from a cross of 2 heterozygous parental plants from the cultivars South China 6 and Mianbao, and analysed with 39 SSR markers. The constructed linkage map of cassava consisted of 12 linkage groups covering a total length of 694.59 cM with a mean distance of 17.81 cM between two markers. The F1 population was evaluated for components of yield including fresh root yield (FRY), harvest index (HI), and starch content in dry root weight (SC) at 90 d, 180 d and 270 d. The identification of QTLs for yield traits at three growth periods explained 56.4% for FRY, 16.3% for HI and 27.3% for SC, suggesting characterization of yield components. The work made a step closer to understand the persistence of quantitative genetic variations of cassava in different development periods.

Abstract: In this study, we researched the degradation of the 2 pesticides (phorate and chlorpyrifos) by Chemical Germicidal Water (CGW). Degradation effect of CGW on the 2 pesticides in spinach was related with reaction time and available chlorine concentrations (ACC). Our research showed that fresh CGW with different ACC had different abilities to reduce the 2 pesticides (phorate and chlorpyrifos). The degradation effect would be strengthened following with the increase of reaction time and ACC. Compared with tap water treatment, the concentration of phorate has significant decrease (P<0.05), which reach above to 92.5% ,8.8%,4.0% and 2.2% after treated with 5 mg/L,10 mg/L,20 mg/L and 50 mg/L ACC, respectively. What’s more, pesticide residues on fresh spinach after 20 minutes of immersion in 5 mg/L,10 mg/L,20 mg/L and 50 mg/L ACC of CGW reduced chlorpyrifos by 86.5% ,21.7% ,9.8% and 7.4%. Further, the best soaking time for CGW was 20 minutes for reduce the degradation of the phorate and chlorpyrifos . These results indicate that CGW is an ideal candidate for reducing the pesticide residues in the field of food processing industry.

Abstract: A reusable electrochemical biosensing strategy based on gold nanoparticle involved layer-by-layer self-assembly for sensitive detection of single nucleotide polymorphisms is proposed in this study. Making use of the strong sulfur-Au affinity, ethanthiol and capture probe modified gold nanoparticles are self-assembled onto the surface of gold electrode successively. The target DNA hybridizes with the capture probe and ferrocene labeled signaling probe successively via sandwich hybridization reaction. By measuring ac current voltammetry, the target DNA can be sensitively detected in a linear dynamic range from 4.1-410 nM with a low detection limit of 2 nM. Making use of self-assembled gold nanoparticles layer, a large amount of capture probes can be modified onto the gold electrode, supporting the high sensitivity of the proposed strategy. In addition, good reproducibility, high selectivity and stability are achieved. In particular, the biosensor can be easily regenerated by melting in hot water, making it reusable.

Abstract: Lytic enzyme produced by Bacillus circulans A1.383-2 was proved to be able to hydrolyze the cell wall of Phaffia rhodozyma effectively and make astaxanthin be extractable by the uniform design. When the hydrolysis temperature and pH to modify the yeast-walls were 37°C and 5.0, respectively, and 33ml lytic enzyme (1603.8u.g^-1 dry yeast) was added, over 98% of the astaxanthin could be extracted within 16.5h.

Abstract: Textiles are necessaries of human life. The fiber content is index of textile quality and how to measure it has important meaning. A method for testing fiber contents in mixture textiles by near infrared spectroscopy (NIR) was researched. The near infrared Spectra of samples in the range of 4000 cm^-1 - 10000 cm^-1 were obtained. Noise reduction and compression of spectra data was done by wavelet transform (WT). The reconstructed spectral signals were established based on WT and the correction models based on back propagation (BP) neural network were built. Comparisons between the BP neural network models at different analysis scale and the model of partial least square method (PLS) were given. When the structure of neural network is 11-9-2 for cotton/ terylene mixture samples and 21-13-2 for cotton/wool mixture samples, the best accuracy and fastest convergence speed is achieved. Experimental results have shown that this approach by Fourier transform NIR based on the BP neural network to predict the fiber content of textile mixture can satisfy the requirement of quantitative analysis and is also suitable for other fiber contents measurement of mixture textiles.

Abstract: The present study was to evaluated the antioxidant capacity and the effect to the D - galactose senile mice of buckwheat vinegar which maked by sprouting buckwheat, divided healthy Kunming male mice into blank, positive control, model and three dose groups of vinega made by stirring buckwheat randomly. After 6 weeks, it was determined the activity of antioxidant enzyme and malondialdehyde in mice with different doses groups. The results showed that: the stirring buckwheat vinegar exhibited strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC₅₀ was 0.58*10^-2 ) and total antioxidant capacity (210.58 mmolFe₂SO₄•ml^-1 ); the vinegar can droped the level of MDA and improved the activity of SOD in liver of D - galactose senile mice. The low-dose group can improved the activity of SOD in serum. However, for the aging mice, the buckwheat vinegar had no effect on behavior when they were in the new environment, the ability of reduced the activity of TChE in brain and the level of MDA in serum was not significant, at the same time, the activity of GSH-px in the serum couldn't be enhanced.

Abstract: Objective: to prepare sustained-release capsules, changchun amine build release degree determination method, study its drug release characteristics and compared with the reference preparation. Methods: using ordinary dissolution apparatus and fiber stripping analyzer to determine the in vitro release of sustained-release capsules. The content determination method, drug to pH 1.5 sodium chloride for the release of the medium of hydrochloric acid solution, using ultraviolet spectrophotometry to release a quantity, at the same time by optical real-time test evaluation of homemade consistency and reference formulation of drug release. Results: the analysis method can be effectively used to build the release of sustained-release capsules to measure, two kinds of similarity factor is more than 50, drug release characteristics match each batch sample, quality and stability. Conclusion: the self-made samples and reference preparation have similar in vitro release characteristics of homemade capsule good slow release effect, drug release and stability.

Abstract: Remote sensing technology is one of the best methods for the large-scale monitoring of chlorophyll in crops. This study analyzes the feasibility of estimating the contents of chlorophyll by means of narrow band normalized difference vegetation indices (NDVI_nb). The reflectance of the two bands forming the NDVI_nb is from simulations run on the PROSPECT model. A traversal of possible combinations of NDVI_nb are examined from 400 nm to 800 nm. Our results indicate that, at the leaf level, estimation of chlorophyll content can be identified in NDVI_nb. Ranges for these bands include: 1) 720-735 nm combined with 400-428 nm; 2) 550-615 nm, 692-701 nm or 707-715 nm combined with 400-432 nm or 462-496 nm; 3) 562-589 nm, 616-662 nm or 729-737 nm combined with 434-454 nm; and 4) 664-687 nm combined with 550-615 nm or 692-701 nm.

Abstract: In order to find the best impact head and threshing moisture content to damage the arrangement law of maize ear,the impact test with different varieties and different moisture of the maize ear is carried out in the drop impact test bench. The experimental result shows that the breakage rate of kernel is smaller and the discrete effect of kernel is better than others in the the action of impact head when moisture content of the maize ear belongs to 14%-20% or less than 12%. The wedge impact head is the most suitable for maize kernel threshing than other impact heads.The effect of maize varieties to the breakage rate is not obvious. The research results can provide a theoretical reference for the low damage threshing method of further research.

Abstract: With the morphological characters, anatomy and molecular biology research, 29 entomopathogenic nematodes populations isolated from Gansu province were identified and the resoult showed that they were 8 species of EPN, Steinernema feltiae,Steinernema bicornutum,Steinernema affin,Steinernema krusse and Steinernema karil were belong to Steinernema while Heterorhabditis brevicaudis,Heterorhabditis megidi and Heterorhabditis marelatu were belong to Heterorhabditis respectively. And what more research found that S. affin,S. krusse,S. karil and H. marelatu were new species in China.