Contribution of phospholipase C-beta3 phosphorylation to the rapid attenuation of opioid-activated phosphoinositide response

Our objective was: (1) to determine the appropriate dose of new ultrasmall superparamagnetic iron oxide particles for magnetic resonance angiography (MRA). This agent comprised of a single iron oxide crystal stabilized with a carbohydrate-polyethylene glycol coat (PEG-Ferron/NC 100150 injection); (2) to determine the proper flip angle for PEG-Ferron-enhanced 3 D time-of-flight (TOF) MRA sequence; and (3) to compare the enhancement of peripheral vessels following PEG-Ferron and GdDTPA-BMA. MRA parameters were: TR/TE = 50/2.1 ms, NEX = 1, FOV = 30 x 30 x 1.8 cm, and matrix = 256 x 128 x 64. In anesthetized beagle dogs (n = 10), the effects of PEG-Ferron and GdDTPA-BMA on regional signal were monitored for 45 min and compared. The lowest dose of PEG-Ferron (0.05 mmol/kg) produced the best enhancement of primary, secondary and tertiary vessels. The flip angle 60 degrees provided better enhancement than 20 degrees on contrast enhanced images. Unlike GdDTPA-BMA, PEG-Ferron allowed prolonged delineation (> 45 min) of the pelvis and lower extremities circulation. PEG-Ferron provided greater Contrast-to-noise ratio CNR (80.2 +/- 6.2, P < 0.05) than GdDTPA-BMA (63.5 +/- 2.5). It may be possible for blood pool contrast-enhanced 3 D TOF MRA to provide valuable information for visualization of vascular tree including guiding interventions.     

Targeting of active sialyltransferase to the plant Golgi apparatus

Glycosyltransferases in the Golgi apparatus synthesize cell wall polysaccharides and elaborate the complex glycans of glycoproteins. To investigate the targeting of this type of enzyme to plant Golgi compartments, we generated transgenic Arabidopsis plants expressing alpha-2,6-sialyltransferase, a glycosyltransferase of the mammalian trans-Golgi cisternae and the trans-Golgi network. Biochemical analysis as well as immunolight and immunoelectron microscopy of these plants indicate that the protein is targeted specifically to the Golgi apparatus. Moreover, the protein is predominantly localized to the cisternae and membranes of the trans side of the organelle. When supplied with the appropriate substrates, the enzyme has significant alpha-2,6-sialyltransferase activity. These results indicate a conservation of glycosyltransferase targeting mechanisms between plant and mammalian cells and also demonstrate that glycosyltransferases can be subcompartmentalized to specific cisternae of the plant Golgi apparatus.     

On the possible role of brain protein synthesis in functional barbiturate tolerance

Pentobarbital pellet implantation increased more than 200% the ED50 dose of pentobarbital required to induce loss of the righting reflex within 2 min of i.p. injection and increased the onset of barbital-induced sleep. Both tests of functional barbiturate tolerance were blocked by the intraventricular injection of cycloheximide. The effects of acute (45 mg/kg i.p.) and chronic (pellet implantation) pentobarbital treatment on the incorporation of 3/-lysine into the protein of various subcellular fractions of the cortex and subcortex were studied. In the subcortex, chronic pentobarbital treatment significantly stimulated protein synthesis 40-50% in the microsomal, soluble and mitochondrial fractions. Both acute and chronic pentobarbital treatments significantly increased (3H-lys)-protein accumulation in a fraction of synaptic plasma membranes derived from a population of nerve ending particles (NEP) enriched in gamma-aminobutyric acid (GABA). The possible significance of these data to pentobarbital tolerance and dependence development is discussed.     

Shielding Theory of Coaxial Cylindrical Structures

A theory on the shielding effectiveness of n coaxial metallic tubings which shield a coaxial cable has been developed based on electromagnetic (EM) field theory. The theory holds for all homogeneous, linear, and isotropic shields, magnetic or nonmagnetic, and covers essentially the entire frequency range. When a cable carries an evenly distributed axial current, the dominant mode of propagation is transverse magnetic (TM) and has only three field components, i.e., Ez, H?, and Er. The fields of the dominant mode leaking from the cable, with and without shields, have been determined rigorously from the solutions of Maxwell's equations and boundary conditions. The shielding effectiveness of the tubings, defined as the insertion loss, has thus been readily obtained. To simplify the obtained expressions to a certain degree such that numerical calculations are manageable, various approximations have been introduced and precisely justified. The limitations imposed on the simplified expression due to the approximations have been clearly listed. It has been shown that Schelkunoff's shielding theory is merely a special case of the present work. As an example, the shielding effectiveness of a single copper tubing surrounding an RG-8/U cable has been considered. The data measured from a carefully designed experimental setup show that at high frequencies, i.e., above 10 kHz, the curve predicted by the present work is about 1 dB above the empirical curve, while the curve due to Schelkunoff is about 5 dB below the empirical curve. At low frequencies, i.e.     

Effects of the variation in α-phase volume fraction on the thermal stability of TiAl alloys with a lamellar microstructure

The thermal stability of two-phase ( + ) lamellar microstructure in Ti-Al-Mo PST (polysynthetically twinned that has single colony) crystals, containing C or Si, was investigated. In addition, the variation of -phase volume fraction in Ti-Al-Mo-(C,Si) systems was investigated at several temperatures. Ti-46Al-1.5Mo-0.2C and Ti-46Al-1.5Mo-1.0Si alloys did not recrystallized (stable in this paper) during heat treatments at various heating rates and temperatures. Moreover, the -phase volume fractions of Ti-46Al-1.5Mo-0.2C and Ti-46Al-1.5Mo-1.0Si alloys which were stable compositions, changed less than those of Ti-47Al and Ti-46Al-1.5Mo alloys which were unstable compositions. The instability of the latter alloys was caused by their relatively higher variation of -phase volume fraction during heating. Therefore, it is suggested that the variation of -phase volume fraction is an important factor in controlling the thermal stability of lamellar microstructure.     

A Subsequence Matching Algorithm that Supports Normalization Transform in Time-Series Databases

In this paper, an algorithm is proposed for subsequence matching that supports normalization transform in time-series databases. Normalization transform enables finding sequences with similar fluctuation patterns even though they are not close to each other before the normalization transform. Simple application of existing subsequence matching algorithms to support normalization transform is not feasible since the algorithms do not have information for normalization transform of subsequences of arbitrary lengths. Application of the existing whole matching algorithm supporting normalization transform to the subsequence matching is feasible, but requires an index for every possible length of the query sequence causing serious overhead on both storage space and update time. The proposed algorithm generates indexes only for a small number of different lengths of query sequences. For subsequence matching it selects the most appropriate index among them. Better search performance can be obtained by using more indexes. In this paper, the approach is called index interpolation. It is formally proved that the proposed algorithm does not cause false dismissal. The search performance can be traded off with storage space by adjusting the number of indexes. For performance evaluation, a series of experiments is conducted using the indexes for only five different lengths out of lengths 256512 of the query sequence. The results show that the proposed algorithm outperforms the sequential scan by up to 2.4 times on the average when the selectivity of the query is 10^–2 and up to 14.6 times when it is 10^–5. Since the proposed algorithm performs better with smaller selectivities, it is suitable for practical situations, where the queries with smaller selectivities are much more frequent.     

A Theoretical Analysis of Query Selection for Collaborative Filtering

We consider the problem of determining which of a set of experts has tastes most similar to a given user by asking the user questions about his likes and dislikes. We describe a simple algorithm for generating queries for a theoretical model of this problem. We show that the algorithm requires at most opt(F)(ln(|F|/opt(F)) + 1) + 1 queries to find the correct expert, where opt(F) is the optimal worst-case bound on the number of queries for learning arbitrary elements of the set of experts F. The algorithm runs in time polynomial in |F| and |X| (where X is the domain) and we prove that no polynomial-time algorithm can have a significantly better bound on the number of queries unless all problems in NP have n ^{O(log log n)} time algorithms. We also study a more general case where the user ratings come from a finite set Y and there is an integer-valued loss function on Y that is used to measure the distance between the ratings. Assuming that the loss function is a metric and that there is an expert within a distance from the user, we give a polynomial-time algorithm that is guaranteed to find such an expert after at most 2opt(F, ) ln + 2( + 1)(1 + deg(F, )) queries, where deg(F, ) is the largest number of experts in F that are within a distance 2 of any f F.     

Injection molding of 316L stainless steel microstructures

Micro powder injection molding (PIM) is a promising process for low cost fabrication of three-dimensional microstructures. The PIM can be used for a wide range of metal and ceramic materials, combined with the potential for mass production. In this paper, initial study on the molding of 316L stainless steel microstructures was investigated. Three different micro-cavity shapes were used. Small powder with mean size of 4 m was used with two multi-component binder systems. Microstructures with dimension as small as 35 m could be injection molded. For successful molding, the binder system must provide high green strength to withstand ejection from the mold and suitable molding parameters used. For example, a high mold temperature is required and ejection speed must be reduced. The cross-sections of the microstructures are precisely replicated. The general shape in the depth direction is replicated although it is not as good as that for the cross-section. More work has to be conducted to realize the full potentials of the process.The authors would like to thank the Nanyang Technological University for awarding a research grant to conduct this research and Adeka Fine Chemicals (Tokyo) for the supply of PAN 250 binder.     

Processor Design in 3D Die-Stacking Technologies

Three-dimensional integration is an emerging fabrication technology that vertically stacks multiple integrated chips. The benefits include an increase in device density; much greater flexibility in routing signals, power, and clock; the ability to integrate disparate technologies; and the potential for new 3D circuit and microarchitecture organizations. This article provides a technical introduction to the technology and its impact on processor design. Although our discussions here primarily focus on high-performance processor design, most of the observations and conclusions apply to other microprocessor market segments.     

Evolutionary design and implementation of a hard disk drive servo control system

The ever increasing demand for higher storage capacity and smaller magnetic hard disk drives have driven the need of developing a high performance head positioning servo control system. To meet the challenge, this paper presents the design and real-time implementation of a robust two-degree-of-freedom servo system for physical 3.5-in. hard disk drive with single voice-coil-motor actuator using a multi-objective evolutionary algorithm toolbox. Besides the simplicity in controller structure, such an evolutionary servo control system is capable of meeting various performance specifications of hard disk drives in both the time and frequency domains. It is shown that the servo system optimally moves the magnetic head onto the desired track with minimal control effort, and keeps it on the track robustly against plant uncertainties or runout disturbances. Validation results of the evolutionary servo control system are compared with classical PID and RPT controllers, which show excellent closed-loop response and robustness in the face of practical perturbations in HDD.