The Elastic Modulus of Nano-Sized Zinc Determined by Laser Ultrasonic Method

The nano — sized materials are the advanced materials developed in the eighties[1]and being called nanocrystalline materials, ultra — fine grained materials or nanophase materials. Because there are a lot of interfaces within the nano — scaled materials, the volume fraction occupied by the interface is comparable with that of particles. The particle size effect and disordering effect of interface exist in the materials. They are referred to have“gaslike” structure. So the nano — sized materials have a number of advantages excelling to the traditional materials properties. Many new phenomena have been discovered from the investigations of their optical and electric properties. However few works are related to their mechanical and ultrasonic properties

Degradation of azo dye orange G in aqueous solutions by persulfate with ferrous ion

2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

The protective effect of ginko bilboa leaves injection on the brain dopamine in the rat model of cerebral ischemia/reperfusion injury

Background: Ginkgo Bilboa injection has had been clinically applied to restore the damaged cells and tissues due to the ischemia through improving the cerebral blood supply and decreasing the oxygen consumption.ObjectiveAim: To evaluate the Ginkgo Bilboa injection's therapeutic role towards ischemia/ reperfusion (I/R) injury through determination of monoamine neurotransmitter dopamine (DA) in corpus striatum.Methods: After the incomplete global cerebral ischemia and reperfusion models were prepared, rats were randomly assigned into four groups: sham-operated group, ischemia-reperfusion group, nimodipine injection group, and Ginkgo Biloba injection group. The cerebrospinal fluid in the rat brain striatum at different time points was collected with microdialysis, and the level of monoamine neurotransmitters dopamineDA was determined by high performance liquid chromatography (HPLC) with electrochemical detector (ECD).Results: The dopamineDA content in cerebral ischemia model group was significantly higher than that in the sham-operated group (P<0.05) at the 30 min. However, the DA level in nimodipine injection group and Ginkgo Biloba injection group were lower than the model group (P<0.05). The dopamineDA level in Ginkgo Biloba injection group gradually decreased, and was significantly different from the model group (P<0.05).Conclusion: Ginkgo Biloba injection can could significantly inhibit brain I/R injury, as demonstrated by prevention of excessive release of dopamineDA in striatum.Key Words: MD-HPLC-ECD; Ginkgo Biloba injection; ischemia/reperfusion; dopamineD

Influences of processing technique on electrical characteristics of TVS used in communication systems

An improved technique is proposed in fabricating a semiconductor surge protection device which is used in high-speed wideband information transmission systems. In order to increase the surge handling capability of the device, a double p-type diffusion is used. Specifically, in the diffusion step of gallium, SiO2 is used as a mask to obtain a very small base width and to avoid the reduction of carrier lifetime. It is found that this is a very useful way to reduce the on-state voltage drop and therefore the energy dissipation of the device.published_or_final_versio

Elevation of marcophage migration inhibitory factor level acute myocardial infarction but not in acute myocardial ischaemia

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Substrate-dependent activation of the Vibrio cholerae vexAB RND efflux system requires vexR

Vibrio cholerae encodes six resistance-nodulation-division (RND) efflux systems which function in antimicrobial resistance, virulence factor production, and intestinal colonization. Among the six RND efflux systems, VexAB exhibited broad substrate specificity and played a predominant role in intrinsic antimicrobial resistance. The VexAB system was encoded in an apparent three gene operon that included vexR; which encodes an uncharacterized TetR family regulator. In this work we examined the role of vexR in vexRAB expression. We found that VexR bound to the vexRAB promoter and vexR deletion resulted in decreased vexRAB expression and increased susceptibility to VexAB antimicrobial substrates. Sub-strate-dependent induction of vexRAB was dependent on vexR and episomal vexR expression provided a growth advantage in the presence of the VexAB substrate deoxycholate. The expression of vexRAB increased, in a vexR-dependent manner, in response to the loss of RND efflux activity. This suggested that VexAB may function to export intracellular metabolites. Support for this hypothesis was provided by data showing that vexRAB was upregulated in several metabolic mutants including tryptophan biosynthetic mutants that were predicted to accumulate indole. In addition, vexRAB was found to be upregulated in response to exogenous indole and to contribute to indole resistance. The collective results indicate that vexR is required for vexRAB expression in response to VexAB substrates and that the VexAB RND efflux system modulates the intracellular levels of metabolites that could otherwise accumulate to toxic levels

Involvement of macrophage migration inhibitory factor (MIF) in graft-versus-host disease (GvHD)

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Low background techniques for the SuperNEMO experiment

SuperNEMO is a 0uββ experiment aiming to reach a half-life sensi¬tivity of 1026 years corresponding to an effective Majorana neutrino mass of (mββ) < 50 - 100 meV. Stringent radio-purity constraints are therefore placed on the detector construction material as well as the gases used in the central detector tracking volume. Radon, 222Rn, is one of the most problematic backgrounds for SuperNEMO due to its decay daughter, 214Bi, having a high Qββ value. Hence the radon level within the SuperNEMO tracker gas mixture must not exceed 150 pBq/m3. This activity is beyond the measurement capability of standard radon detectors, therefore a “Radon Concentration Line” was designed and constructed. This instrument has demonstrated the ability to measure the SuperNEMO tracker gas to a sensitivity of 20 pBq/m3. For large volume of gases the 222Rn activity can be measured with a sensitivity of <5 pBq/m3. Measurements of the fully instrumented quarter trackers and its subsystems have been performed. Radon emanation chambers have also been built to be used with the electrostatic detector which has demonstrated sensitivities of <190 pBq. High-purity germanium detectors offer a standard method to mea-sure material contamination. A dedicated screening facility has been established at Boulby Underground Laboratory with four detectors fully commissioned for low background material measurements. Such a detector can be used to make a highly sensitive measurement of 96Zr decay to the 0+ 1 excited state. Simulations of an experimental setup using 20 kg of 96Zr have shown a sensitivity of 1021yrs can be achieved with a 1 year measurement, a factor of 3 improvement on current world’s best limit