Applied Mechanics and Materials Vols. 295-298

Abstract: 3D-QSAR studies of halogenated phenols screening for acute toxicity were performed by comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. Groups’ data has been modeled to obtain an average estimate and a predictive value for ranking and screening purposes. CoMFA and CoMSIA models have given cross-validation regression coefficient (q²) values of more than 0.80 and correlation coefficient (R²) value of more than 0. 96, which validated for their prediction, could be applied to predict unavailable data.

Abstract: Through pot experiment to research the influence of different concentrations of compound heavy metals pollution on Pakchoi, Brassica chinensis and Celery growth status and several physiological and biochemical indexes. The test results showed that: with the increasing of pollution concentration, the maximum leaf area, plant height, fresh weight of the overground part, catalase activity, vitamin C content and free proline content were not uniform in three kinds of vegetables. The Pakchoi plant height and leaf area were increased at first, then decreased in the trend, biomass declined; the maximum leaf area, plant height and overground parts of the fresh weight of celery are tending to decline; the Brassica chinensis except plant height erratic, maximum leaf area and fresh weight of the overground parts showed a gradual downward trend; the Proline content increased compared with the control group, and celery’s proline content increased when compound heavy metals concentration increased, but the proline content declined of Pakchoi and Brassica chinensis in high heavy metals concentrations. The vitamin C content were lower than the control group, and celery’s vitamin C decreased with the compound heavy metals concentration increased, there was significant difference between the treatments, but Pakchoi and Brassica chinensis did not show a strong regularity; catalase activity of Celery and Brassica chinensis is lower than the control, but it is strong in Pakchoi.

Abstract: An experiment was conducted to study the influence of isoamylase supplementation to maize-soybean diets on productive performance and amylase activities of broilers from 1 to 42 d of age.The results showed that different dose of isoamylase（300g/T,600 g/T,900 g/T, containing 3000IU of isoamylase/g）in the maize - soybean meal diet significantly affected the performance of broilers within 1-42 days. Within 1-21 days , the average daily gain(ADG) of experimental groups( experiment I (E I) experiment II (E II) experiment III (E III) ) improved by 3.2% -10.32%(P>0.05) compared with the control groups(negative control(NC) and positive control(PC)), average daily feed intake(ADFI) improved by 0.63%-7.43%(P>0.05), while feed conversion ratio decreased by 0.55%-4.43%(P>0.05); Within 21-42 days , the ADG of experimental groups decreased by 1.38%-4.84% and ADFI by 11.89%-15.58% (P<0.05), feed conversion ratio by 5.41%-7.54% compared with that in the NC group; Within 1-42 days , the ADG of experimental groups improved by 0.54%-4.06%(P>0.05), while ADFI decreased by 0.75%-11.83% (P<0.05), and feed conversion ratio by 3.97%-7.52% (P>0.05) compared with those in the negative control. Isoamylase supplementation influenced amylase activity of various parts of the chyme in digestive tract and the tissues of small intestine and pancreas. 21 d, the amylase activity in experimental groups improved by 4.67%-79.29%(P<0.05) compared with PC, α-amylase activity in the majority experimental groups were lower than PC group, but the difference was not significant(P>0.05).

Abstract: A quantitative structure-activity relationship (QSAR) study for predicting the acute toxicity 96h - LC50 values of substituted anilines and phenols to carp is presented in this work. For this, the descriptors were obtained with DFT method at the B3LYP/6-311G** level using the Gaussian 03 software package. Afterwards the obtained parameters were taken as theoretical descriptors to establish a QSAR model for predicting -lgLC50. The model contains two variables, energy of the highest occupied molecular orbital (EHOMO) and energy of the lowest unoccupied molecular orbital (ELUMO), which suggest that the main effect on biological toxicity of phenols and anilines is the interaction of electrons between the molecules of organic chemicals. Besides, the model was further validated by variance inflation factors (VIF) and t-test, and show fine stabilities and predictive abilities, which can be used to predict -lgLC50 of these kinds of compounds.

Abstract: In this study IGC50 (50% inhibitory growth concentration) values of 26 nitrobenzenes were determined for population growth endpoint of Paramecium caudatum. Quantitative structure activity relationships (QSARs) were developed using log of the inverse of the IGC50 (logIGC50-1) in mole liter as the dependent variable and 6 molecular descriptors (logP, 1XⅤ, I, 1Ka, ∑σ- and ELUMO) as the independent variables. Through multiplicate regression analysis, one best QSAR equation was obtained. The equation was used to estimate IGC50 for 7 analogues.

Abstract: The aim of this study was to determine the changes of antioxidant activity and antioxidative compounds during table olive preparing by different procedures. The extraction of antioxidants from table olive is studied considering different debittering procedure (alkali treated or brine treated) to investigate the selectivity of the process. The radical-scavenging activity (RSA) of 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and determination of the antioxidant compounds (total phenol, ascorbic acid and tocopherol) are applied to evaluate the antioxidant activity and antioxidative compounds of table olive. The active compounds and DPPH-RSA decreased during table olive preparation. A large amount of the active compounds lost during “alkali treated” except tocopherol. Little amount of the active compounds remained in “brine treated” table olive.

Abstract: The Cladophora and Spirogyra algae examined in this study belong to the Chlorophyta division. Macro filamentous algae, which are widespread in fresh water worldwide, have high potential to be developed as biological materials because of their large biomass and availability. In this study, we collected fresh algae from where they grew and produced bleached and unbleached algae powder using to adsorb Cu(II) ion solution. After the biosorption process, we noted the following four significant findings: (i) The functional groups and binding sites in the produced algae powder were affected, causing variations in the amount of copper adsorbed. The variations resulted from differences in the cell structure, the cell wall thickness of Cladophora and Spirogyra algae, cell composition, and the types and amount of epiphytic algae. (ii) Common bleaching procedures using glacial acetic acid influenced the binding sites of the functional groups and the biomass of the produced powder. Because of the bleaching, the amount of copper adsorbed by the Cladophora powder declined by 14.2%, and by 15.7% for Spirogyra powder. (iii) The carbonyl and hydroxyl groups of unbleached powder were the main elements affected during the bleaching procedures. Examining whether the biosorption experiment results fit Gin’s biosorption model, we found that the biosorption amount and equilibrium reaction of the two bleached algae powders were inferior to that of the unbleached algae powders. (iv) The bleaching procedure using glacial acetic acid was not suitable for producing algae powder to use as an adsorbent for metal ions.

Abstract: Biosorption of heavy metals is an effective technology for the treatment of industrial wastewater. In this paper, Bacillus licheniformis R08 was used as biosorbent for Ag+. The physic-chemical properties of biosorption of silver by Bacillus licheniformis R08 were studied. Experimental parameters, including pH, temperature, biosorption time, initial silver ion concentration and biomass concentration were optimized. Under the optimized conditions, the silver biosorption capacity and biosorption efficiency could reach 73.6mg×g-1 and 73.6%, respectively. Equilibrium isotherms of biosorption by R08 were fitted by Langmuir equation and the theoretical maximum biosorption capacity was 136 mg×g-1. FTIR results showed that-CO-NH and -COO- groups of R08 cell were confirmed to be the main active groups that could combine with silver ions.

Abstract: BP-BF₄ ionic liquid is prepared by the double decomposition reaction of BPC and NaBF₄. The ionic liquid at room temperature used in the experiment has a signific_{Subscript text}ant absorption determined by UV spectrum within the range of 200-400nm, the maximum absorption wavelength of BP-BF₄ ionic liquid is 256nm. The standard working curve of BP-BF₄ ionic liquid is _{Subscript text}y=0.02852x+0.02406 (R=0.99933). The recovery rate of BP-BF₄ ionic liquid which is between 99.6% and 102.2%, is measured by standard addition method in water. The quantitative analysis of BP-BF₄ ionic liquids in water using ultraviolet spectroscopy is simple, accurate and reliable.

Abstract: Diatoms are commonly used for the assessment to determine the unending rivers and lakes due to their broad distribution and its integrative nature. As it is, the corresponding evolution of species and quantity will come into being in diatom communities with the variation of physicochemical characteristics and the pollution of organic, which can indicate directly the local ecological status of aquatic environment. Water samples were collected from 32 sites in unending streams and lakes along with the Yangtze River and its cardinal branches during the mid-July last year, in order to analyze the feature of its distribution and communities. Biological diatom index BDI and the diversity index H′ were used to assess the degree of water eutrophication . We concluded that a great many biometrical indexes are valuable tools for the assessment and future monitoring of waters, combined with the ecological theory, the species of Cyclotella meneghiniana, Stephanodiscus parvus and Navicula subminiscula manifest to be very good indicators for the outbreak of eutrophication in the middle reach region of the Yangtze River and the Han River.