Effectiveness of estradiol in preventing and reversing obesity induced by ovariectomy and high-caloric diet in female rats.

Four experiments with 77 female Holtzman rats examined the effects of estradiol benzoate (EB) on food intake, body weight (BW), ano-nasal length, and BW/body length ratio in ovariectomized (OVX) and intact Ss maintained on control or high-fat diets and of OVX and intact Ss that had been reduced by deprivation. EB was highly effective in preventing the increase in food intake, BW, and ano-nasal growth after OVX; it was relatively ineffective in reversing BW gain after OVX. However, when ano-nasal length was also considered, BW was effective in returning OVX Ss to an appropriate BW for their increased ano-nasal length. Intact Ss fed a high-caloric diet did not exhibit an increased rate of ano-nasal growth, which indicates that the skeletal growth that occurred after OVX was not simply a result of increased food intake. It is concluded that EB modulates food intake and BW by multiple mechanisms, one of which is by modulating skeletal growth. The nature of the effect of EB on BW of intact Ss suggests that this effect occurs by still another mechanism. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fibrin-Based Drug Delivery Systems. II. The Preparation and Characterization of Microbeads

An emulsion method was employed to prepare fibrin beads having different sizes in this study. The oil phase of emulsion system was consisted of mineral oil with various amount of oleic acid as surfactant. Fibrin was converted from fibrinogen with thrombin in Tris buffer solution, then the mixture was emulsified into the oil phase forming droplets. After curing for one hour, 400 ul of glutaraldehyde solution (0.5% v/v) was added to minimize coagulation. The recovery of fibrin beads was simply done by decanting the oil phase and washing the residual with diethyl ether once and then with a mixture of isopropanol and n-hexane (1:3) containing 0.2% w/v Tween 80 twice. As expected, increasing the amount of oleic acid in the oil phase decreased the size of fibrin beads. It is due to the decrease of interfacial tension with increasing oleic acid amount. The presence of macromolecules showed no interference on the formation of fibrin beads except lysozyme. The diffusion characteristics of fibrin beads was evaluated using macromolecules of different molecular weight as model. The size of fibrin beads affected the penetration rate, whereas the effect of molecular weight of macromolecules was inconclusive. An exponential equation was able to approximate the penetration of macromolecules into fibrin beads during the late-time period. The possibility of using fibrin beads as the carrier to deliver protein drugs was appreciated.     

An Open-Loop Computer-Based Drug Infusion System

This study reports the development of a computer-based infusion system and methodology to produce and maintain selected plasma concentrations. The method identifies pharmacokinetic infusion parameters for subjects from bolus injection response data, employs these values in control equations implemented by a portable microcomputer and computer-controlled infusion pump, and achieves and maintains selected stepwise drug levels by intravenous drug infusion. Infusion studies with four dogs and five humans resulted in correlation coefficients of 0.98 for the dogs and 0.94 for the humans, with rms errors in maintaining the drug concentration at the desired level of 13.4 and 19.3 percent, respectively. An analysis of error demonstrated that: 1) the control error was less than the value of the pharmacokinetic parameter estimation error in determining a single parameter value, 2) errors in several parameters can have cancelling or additive effects depending on their sign, and 3) an error in the sum of two of the model parameters (A and B) directly translates to equivalent time-independent error in the controlled level.     

The rolling texture of iron of different purities

Deformation texture of 90% cold rolled iron of various purities was studied by pole figure measurements from which complete orientation distribution functions ODF were calculated using series expansion including the zero range method. The texture type consists of two mutually perpendicular orientation tubes which can be idealized as ( 110 )//RD and ( 111 )//ND in accordance with microstructural investigations which revealed two types of microstructures corresponding to these idealized fibres. The intensity superposition of the two fibres yields a maximum density in slightly deviating positions especially in the vicinity of the intersection of the two tubes which may be idealized as ( 110 ) 30° ND fibre component. The texture of the high-purity iron is nearest to the ( 111 )//ND fibre. Within this general texture type, two subtypes can be distinguished corresponding to high-purity iron on the one hand and the low-purity materials on the other. The texture of the high-purity iron at 90% of deformation still corresponds to the low-degree type of the lower-purity materials which is attributed to the occurrence of dynamic recovery in the high-purity iron.     

Synthesis and Properties of Novel Poly(amide-imide)s Derived from 2,4-diaminotriphenylamine and Imide Ring-Preformed Dicarboxylic Acids

2,4-diaminotriphenylamine (2) was synthesized via the cesium fluoride-mediated aromatic substitution reaction of 1-fluoro-2,4-dinitrobenzene with diphenylamine, followed by palladium-catalyzed hydrazine reduction. A series of poly(amide-imide)s (PAIs) with inherent viscosities of 0.38–0.46 dL/g were prepared by triphenyl phosphite-activated polycondensation from the diamine monomer 2 with various monoimide- and diimide-dicarboxylic acids. All of the PAIs were readily soluble in a variety of organic solvents and formed strong and tough films via solution casting. These PAIs have moderately high glass transition temperatures in the range of 168–274 ^○C and 10 % weight loss temperatures in excess of 447 ^○C in nitrogen or in air.     

Studies of particle holding,separating, and focusing using convergent electrodes in microsorters

This paper presents numerical simulation results on the efficacy of dielectrophoretic (DEP) convergent electrodes in a particle sorter. DEP forces created by non-uniform electric fields are used as holding forces to trap and select the particles from a mixture of many samples, as well as confining forces to focus the particles into a single particle stream in the microsorter for further analysis. The key mechanism of the sorter that can hold particles against destabilizing fluid flows is investigated in this study. A barrier is found at X/L=0.84 and Y=0 in the present DEP sorter. By comparing the DEP and hydrodynamic forces at the barrier, one can determine the release velocity when the zero-net-force condition ceases to exist and the particles start to be released.     

Electroluminescent studies of emission characteristics of InGaAsN/GaAs injection lasers in a wide temperature range

Light-current, spectral, and far-field characteristics of InGaAsN injection lasers on GaAs substrates were studied in a wide temperature range (77–300 K) at various driving current densities. The increase in indium content in InGaAsN solid solution results in a modification of the QW structure, which is manifested in the spontaneous formation of InGaAsN nanoclusters. These changes result in N-shaped temperature dependences of the threshold current density and slope efficiency.     

An Evaluation of the Robustness of MTS for Imbalanced Data

In classification problems, the class imbalance problem will cause a bias on the training of classifiers and will result in the lower sensitivity of detecting the minority class examples. The Mahalanobis-Taguchi System (MTS) is a diagnostic and forecasting technique for multivariate data. MTS establishes a classifier by constructing a continuous measurement scale rather than directly learning from the training set. Therefore, it is expected that the construction of an MTS model will not be influenced by data distribution, and this property is helpful to overcome the class imbalance problem. To verify the robustness of MTS for imbalanced data, this study compares MTS with several popular classification techniques. The results indicate that MTS is the most robust technique to deal with the classification problem on imbalanced data. In addition, this study develops a "probabilistic thresholding method" to determine the classification threshold for MTS, and it obtains a good performance. Finally, MTS is employed to analyze the radio frequency (RF) inspection process of mobile phone manufacturing. The data collected from the RF inspection process is typically an imbalanced type. Implementation results show that the inspection attributes are significantly reduced and that the RF inspection process can also maintain high inspection accuracy.     

A note on total ordering multicast using propagation trees

Jia (1995) proposed a multicast scheme, using propagation trees, to ensure the total ordering (including causal ordering) delivery of messages for group communication. Our study indicates that causal relation between some messages may not actually be presented in this protocol. We then present a revised approach for closed group communication     

Using rotational mirrored declustering for replica placement in a disk-array-based video server

In a video-on-demand (VOD) environment, disk arrays are often used to support the disk bandwidth requirement. This can pose serious problems on available disk bandwidth upon disk failure. In this paper, we explore the approach of replicating frequently accessed movies to provide high data bandwidth and fault tolerance required in a disk-array-based video server. An isochronous continuous video stream imposes different requirements from a random access pattern on databases or files. Explicitly, we propose a new replica placement method, called rotational mirrored declustering (RMD), to support high data availability for disk arrays in a VOD environment. In essence, RMD is similar to the conventional mirrored declustering in that replicas are stored in different disk arrays. However, it is different from the latter in that the replica placements in different disk arrays under RMD are properly rotated. Combining the merits of prior chained and mirrored declustering methods, RMD is particularly suitable for storing multiple movie copies to support VOD applications. To assess the performance of RMD, we conduct a series of experiments by emulating the storage and delivery of movies in a VOD system. Our results show that RMD consistently outperforms the conventional methods in terms of load-balancing and fault-tolerance capability after disk failure, and is deemed a viable approach to supporting replica placement in a disk-array-based video server.