442 research outputs found

    Interstellar Extinction Law in the J, H, and Ks Bands toward the Galactic Center

    Full text link
    We have determined the ratios of total to selective extinction in the near-infrared bands (J, H, Ks) toward the Galactic center from the observations of the region |l| < 2.0deg and 0.5deg < |b| < 1.0deg with the IRSF telescope and the SIRIUS camera. Using the positions of red clump stars in color-magnitude diagrams as a tracer of the extinction and reddening, we determine the average of the ratios of total to selective extinction to be A(Ks)/E(H-Ks) = 1.44+-0.01, A(Ks)/E(J-Ks) = 0.494+-0.006, and A(H)/E(J-H) = 1.42+-0.02, which are significantly smaller than those obtained in previous studies. From these ratios, we estimate that A(J) : A(H) : A(Ks) = 1 : 0.573+-0.009 : 0.331+-0.004 and E(J-H)/E(H-Ks) = 1.72+-0.04, and we find that the power law A(lambda) \propto lambda^{-1.99+-0.02} is a good approximation over these wavelengths. Moreover, we find a small variation in A(Ks)/E(H-Ks) across our survey. This suggests that the infrared extinction law changes from one line of sight to another, and the so-called ``universality'' does not necessarily hold in the infrared wavelengths.Comment: 18 pages, 9 figures, Accepted for publication in the Ap

    Universality of electron accumulation at wurtzite c- and a-plane and zinc-blende InN surfaces

    Get PDF
    Electron accumulation is found to occur at the surface of wurtzite (112¯0), (0001), and (0001¯) and zinc-blende (001) InN using x-ray photoemission spectroscopy. The accumulation is shown to be a universal feature of InN surfaces. This is due to the low Г-point conduction band minimum lying significantly below the charge neutrality level

    Impacts of seasonal transitions of enso on atmospheric river activity over east Asia

    Get PDF
    Atmospheric rivers (ARs), which are narrow water vapor transport bands over the mid-latitudes, often have great socio-economic impacts over East Asia. Although summertime AR activity over East Asia is strongly induced by preceding-winter El Niño development, the extent to which seasonal transitions of El Niño–Southern Oscillation (ENSO) from winter to summer affect the AR activity remains unclear. Here, we examine the relationship between the seasonal transitions of ENSO and the summertime AR activity over East Asia using an atmospheric reanalysis and high-resolution atmospheric general circulation model (AGCM) ensemble simulations. A rapid transition from preceding-winter El Niño to summertime La Niña results in more AR occurrence over northern East Asia via the northward expansion of an anomalous low-level anticyclone over the western North Pacific compared with sustained or decayed El Niño cases. The northward expansion of the anticyclone is consistent with a steady response of the atmosphere to the anomalous condensation heating over the Maritime Continent and equatorial Pacific. Meridional positions of the extratropical AR occurrence and circulation anomalies are different between the reanalysis and AGCM simulations, which is possibly contributed by a limited sample size and/or AGCM biases and suggests that the seasonal prediction of AR-related natural disaster risk over East Asia on a regional scale remains a challenge

    Atmospheric rivers over the Northwestern Pacific: Climatology and interannual variability

    Get PDF
    Atmospheric rivers (ARs), conduits of intense water vapor transport in the midlatitudes, are critically important for water resources and heavy rainfall events over the west coast of North America, Europe, and Africa. ARs are also frequently observed over the northwestern Pacific (NWP) during boreal summer but have not been studied comprehensively. Here the climatology, seasonal variation, interannual variability, and predictability of NWP ARs (NWPARs) are examined by using a large ensemble, high-resolution atmospheric general circulation model (AGCM) simulation and a global atmospheric reanalysis. The AGCM captures general characteristics of climatology and variability compared to the reanalysis, suggesting a strong sea surface temperature (SST) effect on NWPARs. The summertime NWPAR occurrences are tightly related to El Niño-Southern Oscillation (ENSO) in the preceding winter through Indo-western Pacific Ocean capacitor (IPOC) effects. An enhanced East Asian summer monsoon and a low-level anticyclonic anomaly over the tropical western North Pacific in the post-El Niño summer reinforce low-level water vapor transport from the tropics with increased occurrence of NWPARs. The strong coupling with ENSO and IPOC indicates a high predictability of anomalous summertime NWPAR activity

    Antiapoptotic action of anti-Alzheimer drug, TV3326 [(N-propargyl)-(3R)-aminoindan5-yl]-ethyl methyl carbamate, a novel cholinesterase-monoamine oxidase inhibitor.

    Get PDF
    Abstract The anti Parkinson drug, rasagiline [R-(þ)-N-propargyl-1-aminoindan], an inhibitor of type B monoamine oxidase, has been shown to suppress apoptosis induced by neurotoxins and oxidative stress. A series of novel propargylaminoindans with a carbamate moiety to inhibit cholinesterase were developed from phamacophore of rasagiline to protect or rescue deteriorated neurons in Alzheimer&apos;s and Lewy Body disease and provide a beneficial effect on the cognitive deficits. Rasagiline analogues were found to protect dopaminergic SH-SY5Y cells against apoptosis induced by peroxynitrite donor. -(3R)-aminoindan-5-yl]-ethyl methyl carbamate, was as effective as rasagiline in preventing apoptosis, followed by its S-enantiomer, TV3279. The anti-apoptotic-neuroprotective activity was shown to reside in the propargylamine and not the carbamate moiety. This resulted in stabilization of the mitochondrial membrane potential, the collapse of which initiates the apoptotic cascade. q 2003 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Propargylamines; Anti-apoptotic activity; Mitochondrial membrane potential; Monoamine oxidase inhibitor; Cholinesterase inhibitor; Parkinson&apos;s disease; Alzheimer&apos;s disease; Lewy Body disease; Peroxynitrite; Rasagiline; TV3326 Neurodegenerative disorders, such as Parkinson&apos;s (PD) and Alzheimer&apos;s disease (AD), are characterized by progressive cell death of selective neurons in the brain. Apoptosis is considered to be a common type of neuronal cell death in neurodegenerative diseases that may be induced by various environmental and genetic factors. The apoptotic cascade is activated by tightly controlled step-wise processes and has been proposed to be a target of neurorescue or neuroprotective strategies A series of analogues were synthesized with a carbamate cholinesterase inhibitory moiety in the aminoindan structure of rasagiline with the purpose of preserving its neuroprotective activity Rasagiline and derivatives ( SH-SY5Y cells were incubated with 0.01 -10 mM of propargylamine derivatives for 20 min, then cultured for 18 h in the presence of 250 mM SIN-1, and the morphological changes in the cells were observed by phase-contrast and fluorescence microscopy after staining with PI and Hoechst 33342 The effects of SIN-1 with and without propargylamines were examined on mitochondrial permeability transition pore by measurement of DCm, as reported previously The chemical structures of rasagiline and its derivatives, TV3326, TV3279, TV3218 a (3SR)-aminoindan-5-yl]-ethyl methyl carbamate, without the propargyl moiety and TV 3294 (6-hydroxy-rasagiline), a propargylaminoindan metabolite of TV3326 without a carbamate moiety are shown in The effects of TV3326 and rasagiline on DCm were examined by measurement of the reduction in Rhodamin 123 fluorescence. SIN-1 (250 mM) reduced the fluorescence to 28.3% of control, and the pre-treatment with TV3326 or rasagiline (0.1 -10 mM) prevented the fluorescence reduction, as summarized in The present study on the structure-activity relationship among propargylamines studied shows that the propargyl moiety is responsible for the anti-apoptotic activity. The presence of the carbamate moiety in TV3326 and TV3279, did not affect the antiapoptotic function associated with rasagilin

    Effects of mandrel shape on deformation behavior for hot mandrel bending of elbows

    Get PDF
    Elbows of steel pipe joints are used in the industrial plants and are mainly manufactured by the hot mandrelbending from raw material of straight steel pipe. Elbows are generally manufactured at elevatedtemperature by means of pushing, expanding and bending of pipes simultaneously, using the innertool of mandrel. Characteristics of mandrel bending strongly depend on the integrated shape anddimensions of the mandrel. We investigate the effects of shape and dimension of mandrel on deformationbehaviors for hot mandrel bending of elbows, conducting experimental test and numerical analysis. Weclarify the effects of bending radius ratio Rout/Dout, expansion ratio Dout/Din, mandrel length ratio L/Doutand other items of mandrel shape. And optimum conditions of mandrel are estimated as conclusion

    Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage

    Get PDF
    We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe2O3) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the “pure” conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt4BF4 (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of charge–discharge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertion–expulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during charge–discharge processes

    Genetic Spectrum of EYS-associated Retinal Disease in a Large Japanese Cohort: Identification of Disease-associated Variants with Relatively High Allele Frequency

    Get PDF
    Biallelic variants in the EYS gene are a major cause of autosomal recessive inherited retinal disease (IRD), with a high prevalence in the Asian population. The purpose of this study was to identify pathogenic EYS variants, to determine the clinical/genetic spectrum of EYS-associated retinal disease (EYS-RD), and to discover disease-associated variants with relatively high allele frequency (1%-10%) in a nationwide Japanese cohort. Sixty-six affected subjects from 61 families with biallelic or multiple pathogenic/disease-associated EYS variants were ascertained by whole-exome sequencing. Three phenotype groups were identified in EYS-RD: retinitis pigmentosa (RP; 85.94%), cone-rod dystrophy (CORD; 10.94%), and Leber congenital amaurosis (LCA; 3.12%). Twenty-six pathogenic/disease-associated EYS variants were identified, including seven novel variants. The two most prevalent variants, p.(Gly843Glu) and p.(Thr2465Ser) were found in 26 and twelve families (42.6%, 19.7%), respectively, for which the allele frequency (AF) in the Japanese population was 2.2% and 3.0%, respectively. These results expand the phenotypic and genotypic spectrum of EYS-RD, accounting for a high proportion of EYS-RD both in autosomal recessive RP (23.4%) and autosomal recessive CORD (9.9%) in the Japanese population. The presence of EYS variants with relatively high AF highlights the importance of considering the pathogenicity of non-rare variants in relatively prevalent Mendelian disorders
    corecore