Chemical analysis,antioxidant, antiinflammatory and anticholinesterase activities of Origanum ehrenbergii Boiss and Origanum syriacum L. essential oils

The essential oils of Origanum ehrenbergii and O. syriacum collected in Lebanon were analysed by GC and GC–MS and evaluated for their anticholinesterase, NO production inhibitory activities, and antioxidant properties. O.ehrenbergi essential oil was characterised by the presence of 37 components, representing 94.9% of the total oil of which thymol (19%) and p-cymene (16.1%) were the main abundant compounds. Thirty-six compounds characterised the O.syriacum essential oil, representing 90.6% of the total oil. The most abundant components were thymol (24.7%) and carvacrol (17.6%). O. ehrenbergii demonstrated interesting scavenging effects on DPPH with an IC₅₀ value of 0.99 μg/ml. In addition, both O. ehrenbergii and O. syriacum oils inhibited oxidation of linoleic acid after 30 min of incubation, as well as after 60 min of incubation with IC₅₀ values of 42.1 and 33.6 μg/ml, and 46.9 and 58.9 μg/ml, respectively. Interestingly, O. ehrenbergii oil inhibited NO production in the murine monocytic macrophage cell line RAW 264.7 with an IC₅₀ value of 66.4 μg/ml. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of the Ellman’s method. O. ehrenbergii exhibited a strong activity against both cholinesterases with IC₅₀ values of 0.3 μg/ml. The data suggest that O. ehrenbergii and O. syriacum oils could be used as a valuable new flavour with functional properties for food or nutriceutical products with particular relevance to supplements for the elderly.     

驱动单线圈保持继电器的电路

单线圈保持继电器是一种带存储器的继电器,通常带一种能提供两个稳定位置的磁性结构,用于保持可动触点的衔铁。一个永磁铁提供将这些衔铁保持在稳定位置上的力。给继电器线圈施加电流,可将衔     

Associations of blood pressure with self-report measures of anger and hostility among Black and White men and women.

135 Black and White male and female normotensives and unmedicated mild to moderate hypertensives (aged 25–44 yrs) completed 4 reliable self-report scales. Ss also took part in 3 laboratory tasks that elicited cardiovascular reactivity. Ambulatory blood pressure (BP) readings at home and at work were also obtained from most Ss. Black and White Ss differed in their self-reports of anger/hostility and in their cardiovascular reactivity to behavioral tasks. In contrast, the relationships between self-reports of anger/hostility and cardiovascular activity at rest, during laboratory tasks, and at work varied as a function of race–sex combinations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A heuristic Kalman filter for a class of nonlinear systems

One of the basic assumptions involved in the "optimality" of the Kalman filter theory is that the system under consideration must be linear. If the model is nonlinear, a linearization procedure is usually performed in deriving the filtering equations. This approach requires the nonlinear system dynamics to be differentiable. This note is an attempt to develop a heuristic Kalman filter for a class of nonlinear systems, with bounded first-order growth, that does not require the system dynamics to be differentiable. The proposed filter approximates the nonlinear state function by its state argument multiplied by a particular gain matrix only in the recursion of the estimation error covariance matrix. Under certain conditions, the error covariance remains bounded by bounds which can be precomputed from noise and system models, and the upper bound tends to zero when the state noise covariance tends to zero. A numerical example, with backlash nonlinearity, is also added.     

Robustness and convergence rate of a discrete-time learning control algorithm for a class of nonlinear systems

In this paper, we apply a discrete-time learning algorithm to a class of discrete-time varying nonlinear systems with affine input action and linear output having relative degree one. We investigate the robustness of the algorithm to state disturbance, measurement noise and reinitialization errors. We show that the input and the state variables are always bounded if certain conditions are met. Moreover, we shown that the input error and state error converge uniformly to zero in absence of all disturbances. In addition, we show that, after a finite number of iterations, the convergence rate is exponential in l^∞. A numerical example is added to illustrate the results. Copyright © 1999 John Wiley & Sons, Ltd.     

Structure and catalytic activity of POSS-stabilized Pd nanoparticles

Palladium nanoparticles stabilized with polyhedral oligomeric silsesquioxanes have been characterized and determined to function as a heterogeneous catalyst. TEM and SEM studies indicate the material comprises 2–5 nm diameter Pd crystallites in a POSS layer, which aggregate to form spherical secondary structures of about 50 nm in diameter. Solid-state NMR reveals that the primary interaction between Pd and POSS is through the alkyl-amino functional groups on the POSS cage, in addition to some weak interactions with the cage itself. This material is observed by microbalance measurements to efficiently catalyze the direct hydrogenation of 1,4-diphenylbutadiyne.     

Micro-X: Mission Overview and Science Goals

Micro-X, the High-Resolution Microcalorimeter X-ray Imaging Rocket, is a sounding rocket space telescope that will combine a transition-edge-sensor (TES) X-ray microcalorimeter array with a conical imaging mirror to obtain high spectral resolution images of extended and point X-ray sources. Microcalorimeters measure the energy of an absorbed photon by sensing the increase in temperature of the sensor from the thermalization of the absorbed photon’s energy. The advantages and scientific promise of this technology have fueled active development for the past 20 years. We will leverage this development and take the next step by producing a flight-qualified system that will serve as a pathfinder for future missions. Our scientific program will initially focus on extended sources, for which our high-spectral-resolution observations have distinct advantages over other technologies. For our initial flight, we will observe the bright eastern knot in the Puppis A remnant, a site of complex cloud-shock interactions and ejecta enrichment. A Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3–2.5 keV band.      

用实验室电源产生简单的高电流源

当电子测试需要可调电流源时,人们通常必须在实验室构建这种测试仪器。人们可以从标准的力觉实验室电源轻松制作这类电流源（图1）。该电路需要一个为IC供电的额外电源以及一个单独的控制电压。送往力觉电源的反馈信号来自Maxim公司的MAX4172高压侧电流监视器。在图1所示的构造中,