A novel brain-derived member of the epidermal growth factor family that interacts with ErbB3 and ErbB4

The availability of an analgesic compound devoid of the side effects associated with the commonly used opioid and nonsteroidal antiinflammatory drugs would be useful during the perioperative period. Although adenosine has analgesic and anesthetic-sparing properties, it also produces dose-dependent cardiovascular depression. Inhibitors of adenosine kinase may be able to provide analgesia without producing acute cardiovascular or respiratory depression. This preliminary study investigated the effects of a novel adenosine kinase-inhibiting drug, GP683, on the minimum alveolar anesthetic concentration (MAC) of desflurane in dogs. Seven mongrel dogs were administered one of three different GP683 dose regimens (or the solvent) by intravenous infusion on separate occasions according to a cross-over study design. After determining the baseline desflurane MAC value, GP683 was infused at 75, 150, or 300 microg x kg(-1) x min(-1) for 5 min as a loading dose, followed by 15, 30, or 60 microg x kg(-1) x min(-1) for an additional 85 min to maintain a stable plasma drug level. The desflurane MAC was redetermined 30-90 min after starting the study drug or vehicle infusion, and 30-90 min and 120-180 min after termination of the infusion. Cardiovascular variables and plasma concentrations of GP683 were determined at specific intervals before, during, and after the MAC determinations. The three GP683 dose regimens produced 22%, 31%, and 50% decreases in the desflurane MAC, respectively. In addition, there was good correlation between the decrease in desflurane MAC and the plasma GP683 concentration (r = -0.78). Although the mean arterial pressure (MAP) was decreased up to 25% by the highest infusion rate of GP683, adjustments in the desflurane concentration to an equi-MAC value resulted in normalization of the MAP values. Furthermore, GP683 produced no changes in heart rate. In conclusion, the adenosine kinase-inhibiting drug, GP683, produced dose-dependent decreases in the desflurane MAC of dogs without producing untoward hemodynamic changes. IMPLICATIONS: An investigational drug (GP683) that can increase the levels of an important endogenous substance in the body (adenosine) has been found to decrease the anesthetic requirement in dogs without producing adverse effects on the cardiovascular system.     

Effect of the Chiral Center Position of an Optically Active Terminal Group on the Induction of Optical Activity in Polysilanes

Summary Polysilanes with an optically active alkoxy group, i.e., (S)-(+)-2-butoxy, (R)-(-)-2-butoxy, (S)-(-)-2-methyl-1-butoxy, and (S)-(+)-3,7-dimethyl-1-octoxy, at the terminal positions, the chiral carbon centers of which were located at the α, β, and γ positions relative to the oxygen, respectively, were prepared, and the effect of the position of chiral center of the terminal optically active group on the induction of optical activity in polysilanes was investigated. The circular dichroism (CD) spectra of these polymers showed positive Cotton signals around 340 nm at temperatures below -20 °C, but the intensities were small, indicating that the optically active groups at the terminal positions have some ability, albeit small, to induce optical activity to the polysilanes. Further, the optically active (S)-(+)-2-butoxy and (R)-(-)-2-butoxy groups did not control the helical sense direction of the polymers, despite the different chiral stimuli from the 2-butoxy groups introduced to the terminal positions. To control the helical structure of polysilanes by the use of optically active terminal groups, appropriate optically active groups are required.     

Accelerating sequential programs on commodity multi-core processors

A recently proposed pipelined multithreading (PMT) technique exhibits wide applicability in parallelizing general sequential programs on multi-core processors. However, significant inter-core communication overhead limits PMT performance and prevents its commercial utilization. A simple and effective clustered pipelined multithreading (CPMT) approach is presented to accelerate sequential programs on commodity multi-core processors. This CPMT technique adopts a clustered communication mechanism that can yield very low average communication overhead by eliminating false sharing as well as reducing communication operation and transit delays in the software-only approach. A single-producer/single-consumer concurrent lock-free clusteredQueue algorithm based on a two-level queue structure is also proposed. The accuracy of CPMT is theoretically demonstrated. The performances of the algorithm and CPMT are evaluated on a commodity AMD Phenom four-core processor. The number of enqueue and dequeue times of the algorithm are 20.8 and 23 cycles given an appropriate parameter, respectively. The speedup of CPMT ranges from 13.1% to 119.8% for typical loops extracted from the SPEC CPU 2000 benchmark suite.     

A coaxial pulsed plasma thruster using chemical propellants

Pulsed plasma thrusters (PPTs) have the advantages of mechanical simplicity and robustness compared to other electric propulsion systems. However the thrust power ratio of PPTs is lower than that of other electric propulsion systems. To enhance the thrust performance of the PPT, we propose to use several combustible solid chemicals as coaxial PPT propellants to replace Teflon^® (Polytetrafluoroethylene: PTFE). With the design, the force obtained thermodynamically is expected to augment the PPT thrust power ratio with the help of the chemical energy contained in the propellants. As a result, the thrust power ratio is increased using hydroxyl-terminated polybutadiene-ammonium perchlorate (HTPB-AP)-based propellants compared to the case of ordinary Teflon. The discharge current and voltage waveform does not change even when the propellant is changed. These findings could indicate that the impulse bits by gasdynamic contribution are lager in the case of chemical solid propellants than in the case of Teflon.     

HDPE膜预辐照接枝VBTAC制备阴离子交换膜

在氮气保护下,利用预辐照接枝技术在高密度聚乙烯(HDPE)膜上接枝苯乙烯三甲基氯化铵(VBTAC)单体,以甲基丙烯酸二甲氨基乙酯(DMAEMA)单体作为接枝辅助单体来提高VBTAC的接枝率,制备出阴离子交换膜,解决了在HDPE上难以直接接枝聚合VBTAC的问题.本文研究了接枝条件及接枝液的组分对接枝的影响,并用X射线显微分析方法研究了VBTAC的接枝进程和接枝分布.     

Self-assembly of three dimensional micro mechanisms using thermal shrinkage of polyimide

This paper describes three-dimensional microstructures fabricated using a simple self-assembly process involving the thermal shrinkage of polyimide. The proposed method enables hinged structures to be automatically rotated out of the wafer plane and to remain bent without the need to use any interlocking mechanisms. The hinged structures were fabricated using surface micromachining techniques involving heating in a furnace. An increase in the bending angle due to the shrinkage of polyimide was observed with increasing heating temperature, heating time, and length of the polyimide hinge. Of these three parameters, the heating time was found to be the most suitable for precise control of the bending angle. Furthermore, microcubes were fabricated by this method and the self-assembly process was successfully visualized using a CCD camera.     

Development and Use of a Kinetical and Real-Time Monitoring System to Analyze the Replication of Hepatitis C Virus

In microbiological research, it is important to understand the time course of each step in a pathogen’s lifecycle and changes in the host cell environment induced by infection. This study is the first to develop a real-time monitoring system that kinetically detects luminescence reporter activity over time without sampling cells or culture supernatants for analyzing the virus replication. Subgenomic replicon experiments with hepatitis C virus (HCV) showed that transient translation and genome replication can be detected separately, with the first peak of translation observed at 3–4 h and replication beginning around 20 h after viral RNA introduction into cells. From the bioluminescence data set measured every 30 min (48 measurements per day), the initial rates of translation and replication were calculated, and their capacity levels were expressed as the sums of the measured signals in each process, which correspond to the areas on the kinetics graphs. The comparison of various HuH-7-derived cell lines showed that the bioluminescence profile differs among cell lines, suggesting that both translation and replication capacities potentially influence differences in HCV susceptibility. The effects of RNA mutations within the 5′ UTR of the replicon on viral translation and replication were further analyzed in the system developed, confirming that mutations to the miR-122 binding sites primarily reduce replication activity rather than translation. The newly developed real-time monitoring system should be applied to the studies of various viruses and contribute to the analysis of transitions and progression of each process of their life cycle.     

Effectiveness of polyamidoamine dendrimers modified with tripeptide growth factor, glycyl-L-histidyl-L-lysine, for enhancement of function of hepatoma cells

Cationic polyamidoamine dendrimers are known to be highly branched cascade polymers. Tripeptide growth factor, glycyl-L-histidyl-L-lysine (GHK), was employed as a ligand for activation or attachment of cells from a rat hepatoma cell line, H4-H-E-C3, and immobilized at the terminus of the dendrimer (GHK-dendrimer) to develop a suitable surface for use as a culture substratum in the bioartificial liver support system (BAL). The growth of cells was inhibited by increasing the number of generations of GHK-dendrimers. On the other hand, urea synthesis and lidocaine clearance of the cells adhered on fifth generation GHK-dendrimers were enhanced much more than on first generation GHK-dendrimers. GHK was shown to act as a growth inhibitor and an activator of hepatoma cells. These properties of GHK are advantageous for the utilization of hepatoma cells in BAL. Ligand-modified dendrimers are very promising for the creation of a high-performance substratum for cell culture and high performance bioartificial organs, as well as for high-performance bioartificial liver systems. GHK may have the potential to be a highly useful ligand.     

Aerodynamics of high speed trains passing by each other

A three-dimensional flow field induced by two trains passing by each other inside a tunnel is studied based on the numerical simulation of the three-dimensional compressible Euler/Navier-Stokes equations formulated in the finite difference approximation. A domain decomposition method with the FSA (fortified solution algorithm) interface scheme is used to treat this moving-body problem. The computed results show the basic characteristics of the flow field created when two trains pass by each other. The history of the pressure distributions and the aerodynamic forces acting on the trains are the main areas discussed. The results indicate that the phenomenon is complicated due to the interaction of the flow induced by the two trains. Strong side forces occur between the two trains when the front portion of the opposite train passes by. The forces fluctuate rapidly and the maximum suction force occurs when two trains are aligned side by side. The results also indicate the effectiveness of the present numerical method calculating moving boundary problems.     

Radiation-induced polymerization of ethylene in a pilot plant. I. Bulk process

Radiation-induced bulk polymerization of ethylene was carried out with use of a pilot plant with a 10 liter reactor at pressures of 225–400 kg/cm², temperatures of 30–95°C, ethylene feed rates of 5–28 kg/hr, and dose rate of 3.8 × 10⁵ rad/hr. Characteristics of the process are mild polymerization conditions and capability of producing medium density polyethylene in powder form. The spacetime yield and molecular weight of polymer were in the range of 3.5 to 13.1 g/liter hr and 2.2 × 10⁴ to 14 × 10⁴, respectively. The space-time yield increased with mean residence time and 2.4 powders of pressure, and decreased with temperature. Molecular weight changed similarly with the reaction conditions. These results were consistent with those of the bench plant experiment and the scale effect was small. Polymer deposit to the reactor wall limited a period of continuous operation of the plant. The amount of deposited polymer was increased with the square of reaction time. The rate of polymer deposit was proportional to polymer concentration and to the cube of pressure. The polymer deposit cannot be solved in the bulk process.