Effect of surfactants on the spectrophotometric determination of phosphate by direct and extraction procedures

An investigation was carried out of the effects on phosphate analysis of up to 4000 ppm of pure cationic, anionic and nonionic detergents, two industrially prepared detergents and a soap, by both the ascorbic acid and stannous chloride direct methods and the isobutyl acetate extraction procedure. It was found that for the direct methods, the interference was very large for the cationic detergent but negligible for the biodegradable anionic (LAS-type) detergents. The simple and elegant ascorbic acid method is recommended to determine phosphate in most waters and wastewaters on a routine basis. For the extraction procedure, the level of cationic and nonionic detergents must not exceed 2 and 10 ppm respectively, but LAS-type detergents may be present to at least 1000 ppm. Compounds present in formulated detergents interfere badly, therefore the maximum limit of anionic detergent should be set at 8 ppm.     

Investigations of the electrochemical properties of activated carbon and carbon black

Potentiometric studies have been carried out on activated carbon and carbon black immersed in aqueous solutions of electrolytes. The samples studied were subjected to various modifying treatments: demineralization, oxidation in liquid and gaseous phases, saturation with hydrogen, and degassing. It was found that the potential of carbon increases during contact with the electrolyte solution; the amount of anions in the solution decreases with a simultaneous rise of the solution pH. Measurements of the potentials of the carbon samples of large specific surface area immersed in buffer solutions or solutions of established pH have shown that in the range 2.0 < pH < 7.00 the potential of the carbon material decreases with increasing pH. It was also found that the potential of the carbon powder electrode depends on the kind and concentration of the electrolyte solution as well as on the modification of the carbon surface.     

Coping strategies in psychiatric clinical research.

Suggests that classical and elementary approaches to design and analysis of research frequently are based on expectations of the behavior of Ss and of measures of response that are unrealistic in the context of psychiatric clinical research. A broad range of strategies in sampling, measurement, design, execution, implementation, and analysis are examined, and specific strategies are suggested that tend to be successful in the real world of psychiatric clinical research. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biological significance in forward and backward blocking: Resolution of a discrepancy between animal conditioning and human causal judgment.

Similarities between Pavlovian conditioning in nonhumans and causal judgment by humans suggest that similar processes operate in these situations. Notably absent among the similarities is backward blocking (i.e., retrospective devaluation of a signal due to increased valuation of another signal that was present during training), which has been observed in causal judgment by humans but not in Pavlovian responding by animals. The authors used rats to determine if this difference arises from the target cue being biologically significant in the Pavlovian case but not in causal judgment. They used a sensory preconditioning procedure in Exps 1 and 2, in which the target cue retained low biological significance during the treatment, and obtained backward blocking. The authors found in Exp 3 that forward blocking also requires the target cue to be of low biological significance. Thus, low biological significance is a necessary condition for a stimulus to be vulnerable to blocking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polyphenolic profile,antioxidant properties and antimicrobial activity of grape skin extracts of 14 Vitis vinifera varieties grown in Dalmatia (Croatia)

The aim of the present study was to determine polyphenolic composition, related antioxidative and antimicrobial properties of grape skin extracts from 14 grape varieties (seven white and seven red grape) grown in Dalmatia (Croatia). The content of total phenols, flavonoids, catechins, flavanols and individual polyphenols ((+)-catechin, (−)-epicatechin, epicatechin gallate, procyanidin B1 and procyanidin B2, quercetin glucoside, resveratrol monomers, piceid and astringin) was variety dependent. Antioxidant properties were determined as DPPH radical-scavenging ability (IC₅₀), ferric reducing/antioxidant power (FRAP), Fe²⁺-chelating activity (IC₅₀), and using β-carotene bleaching assay. The high antioxidant capacity of all extracts, both red and white, has been observed and related to the relative amounts of polyphenolic compounds with good antioxidant properties. The antimicrobial activity was screened by broth microdilution test using Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative bacteria (Escherichia coli O157:H7, Salmonella Infantis, Campylobacter coli). It was confirmed against all tested organisms. Minimum inhibitory concentrations (MICs), were found in the range 0.014–0.59 mg of gallic acid equivalents (GAE)/ml, with lower MICs of white cultivars, especially against Campylobacter and Salmonella.     

Antioxidants in spring leaves of Oxalis acetosella L.

Oxalis acetosella L. is a common, edible wild plant native to the northern hemisphere. The contents of selected antioxidants, and the antioxidant capacity of young and old spring leaves of O. acetosella, were evaluated. The present study reports foliar contents of ascorbic acid, tocopherols, carotenoids, chlorophyll, flavonoids, phenolic acids and total phenolics, and compares the nutritional value of O. acetosella with other cultivated and wild plants. The composition of foliar antioxidants was found to depend on leaf age. On the other hand, the antioxidant capacity of old leaves were in the same range as young leaves. A comparison between O. acetosela with lettuce analysed in our study, and with numerous cultivated and wild edible plants from other studies, showed that O. acetosella is very rich in β-carotene, ascorbic acid, tocopherols and xanthophylls, and that it is one of the best sources of flavonoids (flavonol glycosides and flavan-3-ols), especially rutin. Therefore, O. acetosella is a potentially important dietary source of antioxidants.     

Evaluation of some physico-chemical properties of restructured trout and hake mince during cold gelation and chilled storage

Cold gelation was carried out on trout (Oncorhynchus mykiss) or on hake (Merluccius merluccius) mince with or without addition of fish oil and using microbial transglutaminase (MTGase). Products were stored at 4 °C for 6 days and lipid oxidation, protein oxidation, texture, water binding capacity, and colour were followed. Results indicated that MTGase was able to generate gels with good properties for both trout and hake. Gels prepared with trout were oxidised whilst gels prepared with hake were stable toward oxidation even in the presence of 5% fish oil. However, in the presence of oil, as an alternative for generating omega-3 enriched products, the activity of MTGase was impaired, as the gels took longer to reach maximum hardness. Furthermore, in all samples containing MTGase, protein oxidation was high.     

Soy protein containing isoflavones favorably influences macrophage lipoprotein metabolism but not the development of atherosclerosis in CETP transgenic mice

The possibility that soy protein containing isoflavones influences the development of experimental atherosclerosis has been investigated in ovariectomized mice heterozygous for the human CETP transgene and for the LDL-receptor null allele (LDLr^+/− CETP^+/−). After ovariectomy at 8 wk of age they were fed a fat/cholesterol-rich diet for 19 wk and divided into three experimental groups: dietary unmodified soy protein containing isoflavones (mg/g of diet), either at low-dose (Iso Low, 0.272, n=25), or at high-dose (Iso High, 0.535, n=28); and the atherogenic diet containing an isoflavone-depleted alcohol-washed soy protein as a control group (n=28). Aortic root lipid-stained lesion area (mean μm²×10³±SD) did not differ among Iso Low (12.3±9.9), Iso High (7.4±6.4), and controls (10.7±12.8). Autoantibody titers against plasma oxidized LDL did not differ among the experimental groups. Using the control mice as the reference value (100%), in vitro mouse peritoneal macrophage uptake of labeled acetylated LDL-cholesterol was lower in the Iso High (68%) than in the Iso Low (85%) group. The in vitro percent removal by exogenous HDL of labeled unesterified cholesterol from macrophages previously enriched with human [4-¹⁴C]-cholesteryl oleate acetylated LDL was enhanced in the Iso High group (50%). In spite of these in vitro potentially antiatherogenic actions, soy protein containing isoflavones did not modify the average size of lipid-stained area in the aortic root.     

机械制造商未来服务理念的一个策略性选择

一、简介 当制造企业以其核心业务为重点时,业务外包和外委服务的方式成为资产管理的一个选择。新的生产模式是建立在协作网络的基础上的,其中如维修、设计和物流由服务者提供,并与企业的工作紧密协作。未来价值网络可能取代价值链,在价值网络中,对于产品和提供的服务,公司提供补充功能和所有资本都是必要的。