Promoters of epithelialization induce expression of vascular endothelial growth factor in human gastric epithelial cells in primary culture

Three routes of heroin use were identified--injecting, 'chasing the dragon' and snorting. Whilst injecting and 'chasing the dragon' accounted for virtually all current heroin use, snorting had been the first route of use for nearly a fifth of heroin users in both the treatment and community samples. Overlap of lifetime experience of the different routes was widespread, with the majority of heroin users in both the treatment and community samples having used heroin by more than one route. Although less than half of the treatment sample had used heroin by injection on the first occasion, more than 90% had injected at least once, and over 80% had at some time used by 'chasing the dragon'. Only a quarter of the community sample had first used heroin by injecting, and yet, by the time of interview, two-thirds of the sample had injected. The majority of durable changes in route of heroin use were towards injecting and 'chasing the dragon', with transitions to snorting being extremely rare. For both the samples, transitions to injecting were twice as frequent as transitions to 'chasing'. Snorting appeared to be an unstable route of use, with almost all who initially snorted their heroin now using by injecting or 'chasing the dragon'.     

Myocardial tactile stiffness: a variable of regional myocardial function

OBJECTIVES: We developed a new sensor system for in situ measurement of myocardial tactile stiffness-stiffness in a direction perpendicular to the wall-and validated its use for providing a reasonable estimation of regional myocardial function. BACKGROUND: Numerous attempts have been made to directly assess regional myocardial function. The complexity and highly invasive nature of the measuring devices have hampered their in situ application. METHODS: In open chest mongrel dogs, myocardial tactile stiffness, ventricular pressure and ventricular volume were monitored. Under the preload reduction, these variables were measured to determine the relation between the end-systolic pressure-volume relation (ESPVR) and the end-systolic tactile stiffness-volume relation (ESSVR). The changes in myocardial tactile stiffness were monitored in the regional ischemic myocardial model and infarcted model to evaluate their usefulness as indexes of regional myocardial function. RESULTS: Myocardial tactile stiffness changed cyclically and followed a time course similar to left ventricular pressure. When preload was altered, the ESSVR was as linear as the ESPVR. The slope of the ESSVR and that of the ESPVR showed a strong correlation over a wide range of contractility. These results suggest that myocardial tactile stiffness can be a good index of regional wall stress or fiber stress. End-systolic myocardial tactile stiffness of ischemic and infarcted regions decreased significantly, with a concomitant increase in end-diastolic stiffness compared with that of intact myocardium. CONCLUSIONS: Using our tactile sensor system, regional myocardial tactile stiffness of a beating heart was measured with reasonable temporal resolution. We consider myocardial tactile stiffness to be a useful index of regional myocardial function.     

The two different states of hepatitis B virus DNA in asymptomatic carriers: HBe-antigen-positive versus anti-HBe-positive asymptomatic carriers

A protein product of the tissue kallikrein gene family was isolated from the submandibular gland of DBA/2N mice. Amino acid sequencing showed this protein to be highly homologous to two tissue kallikreins, mK13 and mK26, also known as prorenin-converting enzymes PRECE and PRECE-2, respectively. The cDNA corresponding to the present enzyme was cloned, and its complete nucleotide sequence was determined. The cloned cDNA was different in 6 and 12 bases out of 783 nucleotides from those of mK1k-13 and mK1k-26 cDNAs, respectively, the homologies being 99.2 and 98.5% (nucleotide), or 98.3 and 96.2% (amino acid). Upon incubation with either bovine kininogens or mouse Ren 2 prorenin, this tissue kallikrein generated bradykinin and renin, respectively, as judged by Western blotting and protein sequence analysis. Isoelectric focusing analysis of the submandibular gland tissue kallikreins suggested that the present enzyme was not expressed in CD-1 or ICR mice and that no mK13 protein was present in DBA/2N mice. These data suggest that the enzyme is an allozyme of mK13, a prorenin-converting enzyme highly expressed in the submandibular gland of DBA/2N mice. The mK1k-13 gene in mice is therefore suggested to be polymorphic, having at least two allelic forms with a high sequence homology. The designation mK13(b) and mK1k-13(b) for the protein and gene of this tissue kallikrein is proposed.     

System separation equipment to minimize power system instabilityusing generator's angular-velocity measurements

The purpose of the equipment described is to separate the power system when an out-of-step between two groups of generators within it is predicted. The out-of-step prediction method is based on the generator's angular-velocity data measured by electromagnetic sensors and gears that are fastened directly to the rotors. The equipment was tested by the large-scale power system simulator APSA (Advanced Power System Analyzer) and was also field tested. The results are presented     

Estimation Methods of Short Circuit Current Using Normal PMU Measurements and Field Testing

This paper proposes estimation methods for short circuit currents using phasor measurement unit (PMU) measurements (phasors). The methods follow the basic notion of representing the source side of a power system by an equivalent circuit with a voltage behind a back impedance, and employ a set of voltage and current phasors measured at substations during the normal variation of loads in their estimation. In order to improve the estimation accuracy of the proposed methods, the concept of using the changes between consecutive phasors is introduced. Furthermore, to make the methods applicable to a real‐world system, the concept of a reference phasor, used to remove the effects of system‐wide frequency variations and a filtering process to filter out the outlier phasors, is proposed and implemented. The validity and effectiveness of the proposed methods were checked and confirmed through experiments and field tests.     

Nanocrystals of zirconia- and ceria-based solid electrolytes: Syntheses and properties

Nano-effect on solid electrolytes that appears as a conductivity enhancement is expected as a way to develop or improve practical solid ionic devices, such as solid oxide fuel cells. Interfaces play a major role in the enhanced conductivity. Using nanocrystals (NCs) as the starting material, the nanostructured materials containing many interfaces, i.e., grain boundaries, can be simply made by forming the NCs with successive sintering without grain growth. The past decade has seen significant advances in the syntheses of solid electrolyte NCs and understanding the nano-effects on the ionic conductivity. In the present paper, the syntheses of zirconia- and ceria-based NCs, which are important constituent materials of solid oxide fuel cells, and their grain size-dependent conductivity due to the nano-effect are briefly reviewed.     

Preparation and fuel cell performance of catalyst layers using sulfonated polyimide ionomers

Sulfonated polyimide (SPI-8) ionomers were used as binders in the catalyst layers, and their fuel cell performance was evaluated. SPI-8 ionomers functioned well in the anode with only minor overpotential even at low humidity (50% relative humidity (RH)). In contrast, the cathode performance was significantly dependent on the content and molecular weight of the ionomers and humidity of the supplied gases. Higher molecular weight of the ionomer caused larger potential drop at high current density at 80 and 100% RH since oxygen supply and/or water discharge became insufficient due to higher water uptake (swelling) of the ionomer. Similar results were obtained at higher ionomer content, because of the increase of thickness in the catalyst layer. The mass transport was improved with decreasing humidity, however, proton conductivity became lower. While the maximum values of j(@0.70?V) for all membrane electrode assemblies (MEAs) were ca. 0.35 A/cm(2), each electrode could have the different appropriate operating conditions. The results suggest that the parameters such as oxygen supply, proton conductivity, and water uptake and discharge need to be carefully optimized in the catalyst layers for achieving reasonable cathode performance with hydrocarbon ionomers.     

Considerations in the design and sensitivity optimization of the micro tactile sensor

Although miniaturization has been considered the only technology with which to increase sensitivity of tactile sensors, we recently developed the micro tactile sensor (MTS) that performs with high sensitivity without microfabrication. In this study, we examined design and sensitivity optimization of the MTS using theory based upon Mason's equivalent circuit. The touch probe, which is attached to the lead zirconate titanate (PZT) element, was expressed as a purely inductive circuit component. Resonance frequency was calculated as a function of the length of the touch probe, and sensitivity was predicted to be dependent on the length. Furthermore, many kinds of MTS were fabricated with different touch probe lengths, and actual sensitivity was measured as phase shift between nonloaded and loaded conditions. And, from the consideration of theory and experimental data, a sensitivity coefficient was proposed and found to be useful.