Immunoglobulin Separation from Egg Yolk: A Serial Filtration System

A serial filtration system was developed for separating immunoglobulin from egg yolk (IgY). Egg yolk was diluted 10 times with water, adjusted to pH 5.0, frozen, then thawed. The diluted yolk was diafiltered through a hard filter paper at 4-6°C to produce a clear water-soluble fraction (WSF). The WSF was then delipidated by filtering through a hydrophobic membrane filter. Ultrafiltration of delipidated WSF at pH 9.0, at 4-6°C, in the presence of 1.5M NaCl resulted in electrophoretically pure (>90%) IgY with a recovery of about 92%. Advantages of this method are the use of only a few mild chemicals and the potential of developing a continuous process.     

OVER-EXPRESSION OF PROLINE-LINKED ANTIOXIDANT PATHWAY AND MODULATION OF PHENOLIC METABOLITES IN LONG LIFE SPAN CLONAL LINE OF ORIGANUM VULGARE IN RESPONSE TO ULTRAVIOLET RADIATION

Tissue culture-generated shoot-based clonal lines of oregano that have a short and long life span during in vitro culture were investigated to determine the role of proline-linked pentose phosphate pathway in modulating phenolic response following ultraviolet (UV) exposure. This novel reductant cycling pathway for energy and oxidative pentose phosphate pathway (PPP) is more efficient in long life span O-17 clonal line in response to UV and this supported antioxidant response. UV treatment stimulated rosmarinic acid and associated antioxidant enzyme response in O-17 clonal line compared with short life span O-3 clonal line. Additionally, O-17 clonal line had higher glucose-6-phosphate dehydrogenase and guaicol peroxidase activity in response to UV exposure compared with O-3 clonal line, indicating stimulation of anabolic pathway supporting PPP during UV treatment. The stimulation of proline dehydrogenase (PDH) activity in O-17 clonal line in response to UV indicated a switch to PDH-linked energy pathway via proline oxidation.

PRACTICAL APPLICATIONS

This oregano clonal model of ultraviolet (UV)-induced oxidative stress management has implications for designing dietary phytochemicals to manage oxidation-linked disease in humans. Further, the correlation between UV-linked inducibility of phenolic-linked antioxidant enzyme response through proline-linked pentose phosphate pathway and life span of in vitro shoot cultures of specific oregano clonal lines can be a good model for aging studies. The metabolic response link to aging and protective phytochemicals can be investigated in oregano tissue cultures, and phenolic extracts from various responding clonal lines could be explored in other eukaryotic aging models.     

平贝母多糖对D-半乳糖诱导衰老模型小鼠的抗氧化作用

为了探讨平贝母多糖对D-半乳糖诱导衰老模型小鼠的体内抗氧化作用,采用颈背皮下注射D-半乳糖(500mg/(kg ·d))建立亚急性衰老小鼠模型,通过对各组小鼠一般体征、脏器指数、血清或肝组织抗氧化酶活性及脑组织单胺氧化酶(MAO)活力的比较分析,全面评价平贝母多糖FUP-1的抗氧化衰老作用。结果表明：与模型组相比平贝母多糖FUP-1能显著降低D-半乳糖诱导衰老小鼠肝脏组织中丙二醛(MDA)含量(P＜0.05),提高肝组织中总抗氧化能力(T-AOC)、显著提高肝组织中谷胱甘肽过氧化物酶(GSH-Px)活性和血清超氧化物歧化酶(SOD)活性(P＜0.05),同时降低脑组织中MAO活力。提示平贝母多糖FUP-1具有一定的延缓衰老作用,其作用可能与其提高抗氧化酶活性和抗脂质过氧化有关。     

USE OF OZONE TO INACTIVATE MICROORGANISMS ON LETTUCE

When ozone (1.3 mM) was bubbled for 3 min in a mixture of shredded lettuce and water, counts ofmesophilic andpsychrotrophic bacteria decreased 1.4 and 1.8 log₁₀ cfu/g, respectively. Counts of these microorganisms on lettuce, from a different batch, decreased 3.9 and 4.6 log, respectively, during 5 min of ozone treatment. Shredded lettuce was treated with gaseous ozone, or mixed with aqueous solution of ozone (1:20 w/w) with or without bubbles. For effective delivery of ozone, stirring (low and high speed), sonication or stomaching was applied during the ozonation. Washing the lettuce with water only decreased total count on shredded lettuce by 0.74–1.0 log cfu/g. When lettuce in a treatment chamber was flushed with gaseous ozone, the total count decreased 0.85 log cfu/g, but when vacuum was applied before the ozone flush, the total count decreased 0.96 log cfu/g. Bubbling ozone in water-lettuce mixture while sonicating, high-speed stirring, or before stomaching inactivated 1.4, 1.9 and 1.9 log cfu/g, respectively. In conclusion, bubbling gaseous ozone in water is the most effective ozonation method. Efficient ozone delivery to microorganisms on lettuce requires a combination of ozone bubbling and high-speed stir.     

IN SITU X-RAY PROBES FOR PIEZOELECTRICITY IN EPITAXIAL FERROELECTRIC CAPACITORS

ABSTRACT

Probing the piezoelectricity and ferroelectricity of thin film devices and nanostructures quantitatively has proven to be challenging because the appropriate experimental tools have had a limited range of usefulness. We show here that the piezoelectric and ferroelectric properties of epitaxial thin films can be measured quantitatively using time-resolved synchrotron x-ray microdiffraction. Microdiffraction combines structural specificity with the appropriate spatial resolution and ability to probe structures with electrical contacts. Our measurements of piezoelectric coefficients and coercive electric fields for Pb(Zr,Ti)O₃ capacitors using this approach are in excellent quantitative agreement with results obtained electrically and mechanically. The time and spatial resolution of microdiffraction probes are well-defined and decoupled from electrical and mechanical resonances of the ferroelectric capacitor.     

孤岛运行方式下微电网储能系统能量成型控制策略

在分析微电网储能系统(ESS)结构的基础上,建立了微电网ESS的端口受控哈密顿(PCH)模型,设计了PCH控制器,确定了期望平衡点,给出了微电网ESS的能量成型控制策略。建立含可再生能源发电单元和ESS的微电网仿真模型对所提策略进行仿真,仿真结果表明,与典型PI闭环线性控制策略相比,所提控制策略在孤岛运行期间能很好地满足对ESS的控制要求,且具有更好的快速性、鲁棒性。     

Variable step-size affine projection algorithm based on global speech absence probability for adaptive feedbackcancellation简

A novel approach is proposed for improving adaptive feedback cancellation using a variable step-size affine projection algorithm（VSS-APA） based on global speech absence probability（GSAP）.The variable step-size of the proposed VSS-APA is adjusted according to the GSAP of the current frame.The weight vector of the adaptive filter is updated by the probability of the speech absence.The performance measure of acoustic feedback cancellation is evaluated using normalized misalignment.Experimental results demonstrate that the proposed approach has better performance than the normalized least mean square（NLMS） and the constant step-size affine projection algorithms.     

Simple reactor for the synthesis of silver nanoparticles with the assistance of ethanol by gas–liquid discharge plasma

Atmospheric pressure plasma technology is gaining increasing importance because it is a simple and tunable synthesis process for the production of metallic nanoparticles. In addition to the development of the power supply, improving the reactor is also one of the main strategies to enhance the utility. In this study, a simple reactor for the gas–liquid discharge plasma induced by argon gas was applied to synthesize silver nanoparticles from silver nitrate (AgNO₃) in solution. An AC power supply with a peak voltage of 3.5 kV was used. The frequency and on-time were set to 50 kHz and 2.5 μs, respectively. The oscilloscope showed that the rising time was approximately 2 μs. The ethanol was used as the source for the reactive reducing agent. No more additional components existed in the solution during the discharge and neither of the electrodes was in contact with the treated solution. The temperature increased by 10 °C within 1min without a cooling system. Carbon was the main impurity and was expected to be produced from the decomposition of the organics under the plasma. The elevated temperature decreased the organic by-products by evaporation and could also decrease the production of carbon. Transmission electron microscopy showed that the spherical silver nanoparticles with a size of approximately 10 nm were synthesized with a crystal structure and that a low concentration of ethanol prefers the production of the mono-dispersed colloid.     

Performance improvement using time delays in multivariable controller design

A new controller for linear multivariable ordinary systems is suggested in which distributed delays are included in the feedback loop. A general design approach to obtain this type of controller is suggested. It is shown that the resulting closed-loop system is asymptotically stable under some sufficient conditions. Sufficient conditions are derived under which the disturbance attenuation, the robustness against parameter variations, and the time-delay stability margins are improved by the proposed controller. The state feedback tracking controller and the dual-state observer are obtained by modification of the proposed controller.