804 research outputs found
Pole inflation in Jordan frame supergravity
We investigate inflation models in Jordan frame supergravity, in which an
inflaton non-minimally couples to the scalar curvature. By imposing the
condition that an inflaton would have the canonical kinetic term in the Jordan
frame, we construct inflation models with asymptotically flat potential through
pole inflation technique and discuss their relation to the models based on
Einstein frame supergravity. We also show that the model proposed by Ferrara et
al. has special position and the relation between the K\"ahler potential and
the frame function is uniquely determined by requiring that scalars take the
canonical kinetic terms in the Jordan frame and that a frame function consists
only of a holomorphic term (and its anti-holomorphic counterpart) for symmetry
breaking terms. Our case corresponds to relaxing the latter condition.Comment: 27 pages, 1 figure; revised version of the manuscript, accepted for
publication in JCA
Polarized XRF Spectrometer with a 40-mW X-Ray Tube
A three-dimensional polarized X-ray fluorescence (XRF) spectrometer was assembled with a low-power X-ray tube of 40 milliwatts, and a sample of stainless steel was measured with an acrylic polarizer. Based on the Schr?dinger’s wave picture of Compton scattering, the dependence of the de Broglie wavelength and the scattering angle of a recoil electron on the incident X-ray energy were calculated. When the incident X-rays were scattered at an angle of 90°, the de Broglie of the recoil electron always went away at an angle of 45° with the incident X-rays and the de Broglie wavelength varied for any wavelength of the incident X-rays, i.e. we could select the scattering angle of the recoil electron to be 45°according to the incident X-ray energy and it could then be regarded as 45° Bragg diffraction that could produce highly polarized X-rays. The polarization measurement of scattered X-rays from an acrylic and lead plates substantiated that Compton scattered X-rays from the acrylic plate had higher degree of polarization than the elastically scattered X-rays from the lead plate. Highly polarized Compton scattered X-rays from the light-element polarizer led to the background reduction and the changes of the characteristic X-ray intensity in XRF spectra measured by our laboratory-made spectrometer.Трехмерный рентгеновский флуоресцентный спектрометр с поляризатором (РФА) был собран с использованием маломощной рентгеновской трубки. Размер спектрометра составлял 25 см в длину, ширина и высота по 10 см. Расстояние от рентгеновской трубки до поляризатора составляло 10 мм, между образцом и детектором ? 10 мм. Камера образцов не вакуумировалась. Образец устанавливали на дно акрилового блока. Рентгеновское излучение падало на поляризатор под углом 45? , и после отражения направлялось на образец под углом в 45? . Использовали рентгеновскую трубку с вольфрамовым анодом фирмы Moxtek (номинальная мощность 4 Вт, максимальное напряжение 50 кВ). В качестве поляризатора использовали акриловую (C5H2 O8 )n пластину площадью 80 мм2 и толщиной 30 мм. Излучение регистрировали детектором SDD (RES-Lab, Osaka) площадью 100 мм2 , толщина кремниевого кристалла составляла 450 мкм. Толщина бериллиевого окна ? 8 мкм. Холодильник Пельтье понижал температуру детектора до -30 ° С. Образец из нержавеющей стали измеряли c акриловым поляризатором. На основе волновой теории Шредингера комптоновского рассеяния рассчитана зависимость длины волны де Бройля и угла рассеяния электрона отдачи в зависимости от энергии падающего рентгеновского излучения. Измерение поляризации рассеянного рентгеновского излучения подтвердило, что некогерентно рассеянное на акриловой пластинке рентгеновское излучение имело более высокую степень поляризации, чем когерентно рассеянное рентгеновское излучение от свинцовой пластины. Высокополяризованное некогерентно рассеянное рентгеновское излучение от поляризатора из элемента с малым атомным номером привело к уменьшению фона и изменению интенсивности характеристического рентгеновского излучения в РФА спектрах, измеренных нашим лабораторным спектрометром
First Total Synthesis of (+/-)-6 '-Methoxyretrojusticidin B Using Regiocontrolled Benzannulation: Structural Inconsistency with Procumphthalide A and Its Revision to 5 '-Methoxyretrochinensin
We achieved the first total synthesis of a novel (+/-)-6'-methoxyretrojusticidin B, which was proposed as procumphthalide A, utilizing regiocontrolled benzannulation of an aryl(aryl')-2,2-dichlorocyclopropylmethanol as the key step. (1)H NMR spectral data suggested that the structure of the synthesized product, 6'-methoxyretrojusticidin B, was inconsistent with that of natural procumphthalide A. A computational study of the rotational barrier rationally supports the existence of a rigid chiral axis in 6'-methoxyretrojusticidin B. The revised structural elucidation of natural procumphthalide A was concluded to be 5'-methoxyretrochinensin.ArticleSYNLETT. 2010(15):2275-2278 (2010)journal articl
Cold Molecular Gas Along the Merger Sequence in Local Luminous Infrared Galaxies
We present an initial result from the 12CO (J=1-0) survey of 79 galaxies in
62 local luminous and ultra-luminous infrared galaxy (LIRG and ULIRG) systems
obtained using the 45 m telescope at the Nobeyama Radio Observatory. This is
the systematic 12CO (J=1-0) survey of the Great Observatories All-sky LIRGs
Survey (GOALS) sample. The molecular gas mass of the sample ranges 2.2 x 10^8 -
7.0 x 10^9 Msun within the central several kiloparsecs subtending 15" beam. A
method to estimate a size of a CO gas distribution is introduced, which is
combined with the total CO flux in the literature. The method is applied to a
part of our sample and we find that the median CO radius is 1-4 kpc. From the
early stage to the late stage of mergers, we find that the CO size decreases
while the median value of the molecular gas mass in the central several kpc
region is constant. Our results statistically support a scenario where
molecular gas inflows towards the central region from the outer disk, to
replenish gas consumed by starburst, and that such a process is common in
merging LIRGs.Comment: 25 pages, 22 figures, accepted for publication in Ap
Bcl-2 genes regulate noise-induced hearing loss
Proteins of the Bcl-2 family have been implicated in control of apoptotic pathways modulating neuronal cell death, including noise-induced hearing loss. In this study, we assessed the expressions of anti- and proapoptotic Bcl-2 genes, represented by Bcl-xL and Bak following noise exposures, which yielded temporary threshold shift (TTS) or permanent threshold shift (PTS). Auditory brainstem responses (ABRs) were assessed at 4, 8, and 16 kHz before exposure and on days 1, 3, 7, and 10 following exposure to 100 dB SPL, 4 kHz OBN, 1 hr (TTS) or 120 dB SPL, 4 kHz OBN, 5 hr (PTS). On day 10, subjects were euthanized. ABR thresholds increased following both exposures, fully recovered following the TTS exposure, and showed a 22.6 dB (4 kHz), 42.5 dB (8 kHz), and 44.9 dB (16 kHz) mean shift on day 10 following the PTS exposure. PTS was accompanied by outer hair cell loss progressing epically and basally from the 4-kHz region. Additional animals were euthanized for immunohistochemical assessment. BcL-xL was robustly expressed in outer hair cells following TTS exposure, whereas Bak was expressed following PTS exposure. These results indicate an important role of the Bcl-2 family proteins in regulating sensory cell survival or death following intense noise. Bcl-xL plays an essential role in prevention of sensory cell death following TTS levels of noise, and PTS exposure provokes the expression of Bak and, with that, cell death. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58028/1/21533_ftp.pd
Generation of human GAPDH knock-in reporter iPSC lines for stable expression of tdTomato in pluripotent and differentiated culture conditions
Human induced pluripotent stem cells (iPSCs) can differentiate into multiple cell types and are utilized for research on human development and regenerative medicine. Here, we report the establishment of human GAPDH knock-in reporter iPSC lines (GAPDH-tdT1 and 2), via CRISPR/Cas9-mediated homologous recombination, that stably express tdTomato as a constitutive cell label in both iPSCs and their differentiated derivatives. These cell lines will provide useful tools to trace cell locations and fates in 2D cultures and 3D organoids and will facilitate in vivo experiments
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