731 research outputs found
Cloud optical thickness and effective particle radius derived from transmitted solar radiation measurements : Comparison with cloud radar observations
A method is presented for determining the optical thickness and effective particle radius of stratiform clouds containing liquid water drops in the absence of drizzle from transmitted solar radiation measurements. The procedure compares measurements of the cloud transmittance from the ground at water-absorbing and nonabsorbing wavelengths with lookup tables of the transmittance precomputed for plane-parallel, vertically homogeneous clouds. The optical thickness derived from the cloud transmittance may be used to retrieve vertical profiles of cloud microphysics in combination with the radar reflectivity factor. To do this, we also present an algorithm for solving the radar equation with a constraint of the optical thickness at the visible wavelength. Observations of clouds were made in August and September 2003 at Koganei, Tokyo, Japan, using a PREDE i-skyradiometer and a 95-GHz cloud radar Super Polarimetric Ice Crystal Detection and Explication Radar (SPIDER). The optical thickness and effective radius of water clouds were derived from the i-skyradiometer. Then, the vertical profile of the effective radius was retrieved from SPIDER, using the optical thickness determined from the i-skyradiometer. We found that the effective radii derived by using these two instruments were in good agreement
Environmental monitoring and assessment of short-term exposures to hazardous chemicals of a sterilization process in hospital working environments.
In order to assess short-term exposures to ethylene oxide, formaldehyde and glutaraldehyde in a sterilization process, the authors conducted continuous environmental monitoring of these chemicals in the breathing zone of workers in 2 hospitals. The arithmetic mean of ethylene oxide was 1.2 ppm near unventilated cabinets housing sterilizing materials, and environmental concentrations of ethylene oxide could not be reduced under threshold limit values time weighted average by only managing general ventilation. Environmental concentration of formaldehyde was lower in a properly ventilated pathology division in which no large specimens were stored (0.3 ppm) than in the pathology division where large specimens were stored (2.3 ppm). Although environmental concentrations of glutaraldehyde in an endoscopy unit with proper general ventilation were not detectable, environmental concentration levels in an endoscopy unit without general ventilation system were 0.2 and 0.5 ppm. According to the results of environmental monitoring in the breathing zone of workers, extremely high concentrations were observed in some work practices (ethylene oxide, 300 ppm; formaldehyde, 8.6 ppm; glutaraldehyde, 2.6 ppm). In order to avoid occupational exposures to these chemicals and prevent potential chronic and acute health hazards, good communications with these chemicals, good work practices, appropriate personal protective equipment, and engineering controls should be required.</p
(R)-2-Benzyl-4-methylpentyl (R)-2-methoxy-2-(1-naphthyl)propionate
The relative configuration of the alcohol component in the title ester, C27H32O3, has been assigned as (R) from the known configuration of (R)-(−)-2-methoxy-2-(1-naphthyl)propionic acid [(R)-MαNP acid]. In the crystal structure, the C atom of the methyl group of the MαNP acid lies in the extended plane of the naphthyl ring system [methyl C atom deviates from plane by 0.211 (2) Å; r.m.s. deviation of fitted atoms = 0.0187 Å] and a weak intramolecular C—H⋯O hydrogen bond links the naphthyl ring system and the methoxy group. These structural properties are similar to those of most MαNP acid esters
993-40 Characteristics of the Atrial Signal-averaged Electrocardiograms in Patients with Sick Sinus Syndrome – the Presence of “Atrial Early Potential”
In sick sinus syndrome (SSS), pathophysiological abnormalities have been shown not only in the sinus node but also in the atrial muscle, especially of the perinodal portion. To investigate whether the electrophysiological abnormalities of atrial muscle in SSS would induce the characteristic P wavepattern, especially in the initial portion of the P wave, we studied 37 patients with SSS and 67 age-comparable control patients. using the P wave-triggered signal-averaged electrocardiography. Sixteen of 37 SSS patients had paroxysmal atrial fibrillation (Paf). Signal-averaged electrocardiograms were recorded with a band-pass filter of 40–300Hz and signals of 200 beats or more were averaged with the P wave-triggering technique. The P wave complexes of the three bipolar leads were combined into a spatial magnitude, and then the root mean square voltage for the initial 30ms (EP30) and the last 20m (LP20) of filtered P wave were measured. The duration (Ad) and root mean square voltage (RMS) of the total filtered P wave were also measured.ResultsSSS with PafSSS without PatControlEP30 (μV)2.55±1.17*2.16±0.98*3.93±1.23LP20 (μV)1.98±0.40#†2.79±1.043.35±1.76Ad (ms)145.8±16.1*†131.2±14.1123.7±11.7RMS (μV)6.20±0.415.82±0.826.20±1.47*p<0.0001#P<0.005p<0.05 vs. Control†p<0.01 vs SSS Without PatThe amplitude of initial portion of filtered P wave was significantly lower and the duration was longer in SSS patients with/without Paf than the controls, while there was no significant difference in the amplitude of the terminal portion between SSS patients without Paf and controls. The criteria of “EP30≤3.0μV and Ad>130m” as defining “atrial early potential” gave a sensitivity of 76%, a specificity of 83% and a predictive accuracy of 81% for detection of patients with SSS. These results indicate that the low amplitude signals in the initial portion of filtered P wave were characteristic of SSS, so that the recognition of atrial early potential might be promising to identify patients with SSS
Vulcanian eruptions with dominant single force components observed during the Asama 2004 volcanic activity in Japan
DNA methyltransferase 3B plays a protective role against hepatocarcinogenesis caused by chronic inflammation via maintaining mitochondrial homeostasis
Most hepatocellular carcinomas (HCCs) develop on the basis of chronic hepatitis, but the mechanism of epigenetic regulation in inflammatory hepatocarcinogenesis has yet to be elucidated. Among de novo DNA methyltransferases (DNMTs), DNMT3B has lately been reported to act specifically on actively transcribed genes, suggesting the possibility that it plays a role in the pathogenesis of cancer. We confirmed that DNMT3B isoforms lacking its catalytic domain were highly expressed in HCCs compared with non-tumorous liver tissue. To elucidate the role of DNMT3B in hepatocarcinogenesis, we generated a genetically engineered mouse model with hepatocyte-specific Dnmt3b deletion. The liver of the Dnmt3b-deficient mice exhibited an exacerbation of thioacetamide-induced hepatitis, progression of liver fibrosis and a higher incidence of HCC compared with the liver of the control mice. Whole-genome bisulfite sequencing verified a lower CG methylation level in the Dnmt3b-deficient liver, demonstrating differentially methylated regions throughout the genome. Transcriptome analysis revealed decreased expression of genes related to oxidative phosphorylation in the Dnmt3b-deficient liver. Moreover, primary hepatocytes isolated from the Dnmt3b-deficient mice showed reduced mitochondrial respiratory capacity, leading to the enhancement of oxidative stress in the liver tissue. Our findings suggest the protective role of DNMT3B against chronic inflammation and HCC development via maintaining mitochondrial homeostasis
Vascular Dysfunction in Patients with Chronic Arsenosis Can Be Reversed by Reduction of Arsenic Exposure
Chronic arsenic exposure causes vascular diseases associated with systematic dysfunction of endogenous nitric oxide. Replacement of heavily arsenic-contaminated drinking water with low-arsenic water is a potential intervention strategy for arsenosis, although the reversibility of arsenic intoxication has not established. In the present study, we examined urinary excretion of cyclic guanosine 3′,5′-monophosphate (cGMP), a second messenger of the vasoactive effects of nitric oxide, and signs and symptoms for peripheral vascular function in 54 arsenosis patients before and after they were supplied with low-arsenic drinking water in an endemic area of chronic arsenic poisoning in Inner Mongolia, China. The arsenosis patients showed a marked decrease in urinary excretion of cGMP (mean ± SEM: male, 37.0 ± 6.1; female, 37.2 ± 5.4 nmol/mmol creatinine), and a 13-month period of consuming low-arsenic drinking water reversed this trend (male, 68.0 ± 5.6; female, 70.6 ± 3.0 nmol/mmol creatinine) and improved peripheral vascular response to cold stress. Our intervention study indicates that peripheral vascular disease in arsenosis patients can be reversed by exposure cessation and has important implications for the public health approach to arsenic exposure
Development of Nine Markers and Characterization of the Microsatellite Loci in the Endangered Gymnogobius isaza (Gobiidae)
Gymnogobius isaza is a freshwater goby endemic to Lake Biwa, Japan. They experienced a drastic demographic bottleneck in the 1950s and 1980s and slightly recovered thereafter, but the population size is still very small. To reveal dynamics of genetic diversity of G. isaza, we developed nine microsatellite markers based on the sequence data of a related goby Chaenogobius annularis. Nine SSR (Simple Sequence Repeats) markers were successfully amplified for raw and formalin-fixed fish samples. The number of alleles and expected heterozygosities ranged from one to 10 and from 0.06 to 0.84, respectively, for the current samples, while one to 12 and 0.09 to 0.83 for historical samples. The markers described here will be useful for investigating the genetic diversity and gene flow and for conservation of G. isaza
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