Carbon-centered radicals in isolated soy proteins

ABSTRACT:  Solid-state electron paramagnetic resonance (EPR) spectroscopy of commercial samples of isolated soy proteins (ISP) revealed a symmetrical free-radical signal typical of carbon-centered radicals ( g = 2.005) ranging from 2.96 × 10¹⁴ to 6.42 × 10¹⁴ spins/g. The level of free radicals in ISP was 14 times greater than similar radicals in sodium caseinate, 29 times greater than egg albumin, and about 100 times greater levels than casein. Nine soy protein powdered drink mixes contained similar types of free radicals up to 4.10 × 10¹⁵ spins/g of drink mix, or up to 6.4 times greater than the highest free-radical content found in commercial ISP. ISP samples prepared in the laboratory contained trapped radicals similar to the levels in commercial ISP samples. When ISP was hydrated in 2.3 mM sodium erythorbate or 8.3 mM L-cysteine, frozen and dried, the level of trapped free radicals increased by about 17- and 19-fold, respectively. The ESR spectrum of defatted soybean flakes contained overlapping signals from the primary free-radical peak ( g = 2.005) and a sextet pattern typical of manganese-II. The manganese signal was reduced in the laboratory ISP and very weak in the commercial ISP.     

Incidence of Salmonella in five Swedish slaughterhouses

Five Swedish slaughterhouses where pig slaughter takes place were sampled and tested for Salmonella. Each slaughterhouse was visited six times, and sampling was done repeatedly at specific points in the slaughter line during the day. Both sampling of pork carcasses and the slaughterhouse environment was done. This study was part of a larger European project, entitled Salmonella in Pork (Salinpork), with the aim of identifying specific risk points or risk factors associated with Salmonella contamination that contribute to health hazards for humans. During the study, a total of 3,388 samples from the five slaughterhouses were collected and cultured for Salmonella. All of the samples were culture negative for Salmonella.     

浮选回收粗粒磷酸盐时的细粒效应

用浮选选别佛罗里达磷酸盐矿石时,为了优化选别效率,给料通常分成粗粒(-16+35目)和细粒(-35+150目)两级别入选。粗粒浮选的回收率相当低(-16％),而通常细粒浮选的效率很高,回收率大约为90％。已经证实,细粒级和粗粒级以适当的比例混合可以提高总的浮选效率。细粒存在时粗粒回收率的提高被认为是由于细粒的加入改进了泡沫特性。又证明,在自然给料中,粗粒与细粒比例不利于混合物料浮选时,添加少量的预先调好的细粒,能在很大程度上提高粗粒的回收率。     

Pasteurization of milk and the heat resistance of Mycobacterium avium subsp. paratuberculosis: a critical review of the data

Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) causes Johne's disease in ruminants (including cattle, sheep and goats) and other animals, and may contribute to Crohn's disease in humans. This possibility, and the fact that M. paratuberculosis may be present in raw milk, make it important to ensure that the heat treatment specified for pasteurization of milk will give acceptable inactivation of this bacterium, with an adequate margin of safety. Published studies of the heat resistance of this bacterium in milk have given widely differing results. Possible reasons for these differences, and the technical problems involved in the work, are reviewed. It is concluded that there is a need (i) for the adoption of an agreed Performance Criterion for pasteurization of milk in relation to this bacterium, (ii) a need for definitive laboratory experiments to understand and determine the heat resistance of M. paratuberculosis, and (iii) a need for an assessment of whether the minimum heat treatments specified at present for pasteurization of milk (Process Criteria) will meet the Performance Criterion for M. paratuberculosis. Measures are also required to ensure that commercial processes deliver continually the specified heat treatment, and to ensure that post-pasteurization contamination is avoided.     

Nine-analyte detection using an array-based biosensor

A fluorescence-based multianalyte immunosensor has been developed for simultaneous analysis of multiple samples. While the standard 6 x 6 format of the array sensor has been used to analyze six samples for six different analytes, this same format has the potential to allow a single sample to be tested for 36 different agents. The method described herein demonstrates proof of principle that the number of analytes detectable using a single array can be increased simply by using complementary mixtures of capture and tracer antibodies. Mixtures were optimized to allow detection of closely related analytes without significant cross-reactivity. Following this facile modification of patterning and assay procedures, the following nine targets could be detected in a single 3 x 3 array: Staphylococcal enterotoxin B, ricin, cholera toxin, Bacillus anthracis Sterne, Bacillus globigii, Francisella tularensis LVS, Yersiniapestis F1 antigen, MS2 coliphage, and Salmonella typhimurium. This work maximizes the efficiency and utility of the described array technology, increasing only reagent usage and cost; production and fabrication costs are not affected.     

Carbon and nitrogen fluxes in a closed seawater facility

A variety of empirical and calculated data from the largest tank at the New Jersey State Aquarium were used to quantify the fluxes of carbon and nitrogen before and after the installation of denitrification in this facility. Before denitrification, the stock of dissolved inorganic carbon (DIC) in Ocean Tank exhibited a decrease of 6.9 kg C/month and sodium bicarbonate had to be added to maintain DIC in steady state. We were able to explain the DIC decrease by two non-conservative processes: the formation of carbonaceous precipitates (removes 4.2 kg C/month) and outgassing of carbon dioxide due to acidity from nitrification (independently determined to remove 3.2 kg C/month). Nitrogen budget in Ocean Tank before denitrification is in contrast to that of carbon, and it shows an increase of 4.8 kg N/month in the form of nitrate. Denitrification is currently removing 53.3 kg N/month (in the form of nitrogen gas), so this element should eventually reach steady state. The use of methanol for denitrification has resulted in a flux of 26.3 kg C/month into the aquarium and, as predicted, an increase in Ocean Tank DIC stock has been observed without any additions of sodium bicarbonate. Our approach can be used to model carbon and nitrogen balances in closed seawater facilities that host heterotrophic organisms and operate either with or without a biological denitrification system.     

Blood speed imaging with an intraluminal array

In applications in which Doppler processing is not possible, such as side-looking intravascular imaging systems, decorrelation methods can be used to estimate blood speed. Here, a method is presented measuring relative blood speed using an FIR filter bank to estimate temporal decorrelation rates. It can be implemented in a modern commercially available ultrasound imaging system with no additional hardware. Both simulations and experiments using an intraluminal scanner appropriate for coronary artery applications have tested the system. In this study, the FIR filter bank is contrasted with previous methods, and its utility is further demonstrated with real-time color flow images from a pig model.     

布列依水利枢纽运行期的泄水建筑物及水力学论证

布列依水电站泄水建筑物为８跨溢洪道，采用挑流鼻坎防止建筑物和左岸被大泄量水流冲刷。为此进行了多种模型试验，以探讨水力学特性。试验得出：双层挑流鼻坎结构辅以掺气装置掺气，可大大减轻水流对建筑物、左岸及河床的冲刷。