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61.
Conflicting results have been reported in literature about the influence of beta-adrenergic stimulation on the fast cardiac sodium current (INa+). To elucidate these mechanisms in multicellular preparations we used the loose-patch-clamp technique to evaluate the effect of the beta-adrenergic agonist isoproterenol 1-1000 nmol/l. Isoproterenol enhanced INa+ at all membrane potentials by elevation of the maximal available INa+ . Only at the high concentration of 1 micromol/l was INa+ slightly depressed after depolarizing conditioning clamps. The most marked increase of the maximal available INa+ was 30+/-9% after application of 100 nmol/l isoproterenol. To learn about the mechanisms in view of sodium channel modulation we combined isoproterenol with the sodium channel blocker lidocaine (47 micromol/l). Under these circumstances the effects of both drugs were completely independent. This investigation shows clearly that low concentrations of isoproterenol increase INa+ in multicellular preparations by a gating-independent mechanism.  相似文献   
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63.
The estimation of tetrachloethene (PCE) dechlorinating-activity and identification of PCE-dechlorinating bacteria were performed in 65 unsaturated subsurface soils (at a depth 30-60 cm) that were collected from 21 noncontaminated soils and 44 chloroethene-contaminated soils including four soils that dechlorinated PCE to 1,2-cis-dichloroethene (cisDCE) in situ. Sixteen out of the 44 PCE-contaminated soils and three out of the 21 noncontaminated soils dechlorinated PCE to trichloroethene and cisDCE but not vinyl chloride or ethene after a month of incubation with 0.1% yeast extract at 30 degrees C. Desulfitobacterium sp. strain B31e3 that can dechlorinate PCE to cisDCE was isolated from a soil that dechlorinated PCE to cisDCE in situ. 16S rRNA gene of this strain showed the closest similarity of 99.1% with that of Desulfitobacterium hafniense (formally frappieri) strain DP7. Real-time PCR using specific primer sets targeted to the 16S rRNA genes of the representative PCE-dechlorinating bacteria, Dehalococcoides spp., Desulfitobacterium spp., and Dehalobacter spp. were performed using five unsaturated subsurface soils that dechlorinated PCE and three that did not dechlorinate PCE. In two out of the five soils that dechlorinated PCE, Desulfitobacterium spp. (0.12, 0.38% of total bacteria) and Dehalobacter spp. (0.0045, 0.0061% of total bacteria) were detected, and in one of the five soils, only Desulfitobacterium spp. (0.042% of total bacteria) was detected. None of these representative PCE-dechlorinating bacteria were detected in two out of the five soils that dechlorinated PCE and in all of the three soils that did not dechlorinate PCE. Dehalococcoides spp. were not detected in any unsaturated subsurface soils used in this study. These results suggested the involvement of Desulfitobacterium spp. and probably Dehalobacter spp. rather than Dehalococcoides spp. in the dechlorination of PCE to cisDCE in unsaturated subsurface soils.  相似文献   
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Highly acidic catalysts stronger than the SO4/ZrO2 superacid with an acid strength of Ho –16.04 were obtained by kneading Zr(OH)4 with ammonium sulfate together with chlorides of Ir, Pt, Rh, Ru, Os, and Pd followed by calcining in air at 600°C, the metal concentration being equivalent to Pt of 7.5 wt% based on the hydroxide. The catalysts with Ir and Pt materials were highest in activity for the skeletal isomerization of butane to isobutane. The present catalysts were not obtained by treating the crystallized oxide, ZrO2 calcined at 700°C, but the amorphous form followed by calcination to the crystallization.Superacids by metal oxides, VI. For previous publication in this series see ref. [1].  相似文献   
66.
67.
The purpose of this paper is to improve the bonding strength of tape-automated bonding (TAB) technology in supertwisted nematic liquid crystal display (STN LCD) module manufacturing by double-process control. First, the quality characteristic – the output of the process – is monitored by control charts and the variation of the process is reduced. Later, it is found that the quality characteristic is affected by critical input process parameters. These critical input process parameters and the quality characteristic are therefore monitored simultaneously. By this double-process control, the deviation of the process is further reduced. The results show that process capability and yield rate are increased.  相似文献   
68.
Groundwater replenishment by infiltration of road runoff is expected to be a promising option for ensuring a sustainable urban water cycle. In this study, we performed a soil infiltration column test using artificial road runoff equivalent to approximately 11-12 years of rainfall to evaluate the removal of pollutants by using various chemical analyses and bioassay tests. These results indicated that soil infiltration treatment works effectively to remove most of the pollutants such as organic matter (chemical oxygen demand (CODMn) and dissolved organic carbon (DOC)), P species, polycyclic aromatic hydrocarbons (PAHs), numerous heavy metals and oestrogenic activities. Bioassay tests, including algal growth inhibition test, Microtox and mutagen formation potential (MFP) test, also revealed effective removal of toxicities by the soils. However, limited amounts of NO3, Mn, Ni, alkaline earth metals, perfluorooctane sulphonate (PFOS) and perfluorooctane sulphonamide (FOSA) were removed by the soils and they possibly reach the groundwater and cause contamination.  相似文献   
69.
Inhalation of particulate matter is associated with adverse health outcomes. The fluorescent portion of supermicron particulate matter has been used as a proxy for bioaerosols. The sources and emission rates of fluorescent particles in residential environments are not well-understood. Using an ultraviolet aerodynamic particle sizer (UVAPS), emissions of total and fluorescent supermicron particles from common human activities were investigated during the HOMEChem campaign, a test-house investigation of the chemistry of indoor environments. Human occupancy and activities, including cooking and mopping, were found to be considerable sources of indoor supermicron fluorescent particles, which enhanced the indoor particle concentrations by two orders of magnitude above baseline levels. The estimated total (fluorescent) mass emission rates for the activities tested were in the range of 4-30 (1-11) mg per person meal for cooking and 0.1-4.9 (0.05-4.7) mg/h for occupancy and mopping. Model calculations indicate that, once released, the dominant fate of coarse particles (2.5-10 micrometer in diameter) was deposition onto indoor surfaces, allowing for the possibility of subsequent resuspension and consequent exposures over durations much longer than the ventilation time scale. Indoor coarse particle deposition would also contribute to soiling of indoor surfaces.  相似文献   
70.
Semivolatile organic compounds (SVOCs) emitted from building materials, consumer products, and occupant activities alter the composition of air in residences where people spend most of their time. Exposures to specific SVOCs potentially pose risks to human health. However, little is known about the chemical complexity, total burden, and dynamic behavior of SVOCs in residential environments. Furthermore, little is known about the influence of human occupancy on the emissions and fates of SVOCs in residential air. Here, we present the first‐ever hourly measurements of airborne SVOCs in a residence during normal occupancy. We employ state‐of‐the‐art semivolatile thermal‐desorption aerosol gas chromatography (SV‐TAG). Indoor air is shown consistently to contain much higher levels of SVOCs than outdoors, in terms of both abundance and chemical complexity. Time‐series data are characterized by temperature‐dependent elevated background levels for a broad suite of chemicals, underlining the importance of continuous emissions from static indoor sources. Substantial increases in SVOC concentrations were associated with episodic occupant activities, especially cooking and cleaning. The number of occupants within the residence showed little influence on the total airborne SVOC concentration. Enhanced ventilation was effective in reducing SVOCs in indoor air, but only temporarily; SVOCs recovered to previous levels within hours.  相似文献   
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