A correlation between light profile and [Mg/Fe] abundance ratio in early-type galaxies

We explore possible correlations between light profile shapes, as parameterized by the Sersic index or the concentration index C_re(1/3), and relevant stellar population parameters in early-type galaxies. Mean luminosity weighted ages, metallicities and abundance ratios were obtained from spectra of very high signal-to-noise and stellar population models that synthesize galaxy spectra at the resolution given by their velocity dispersions, in combination with an age indicator that is virtually free of the effects of metallicity. We do not find any significant correlation between the Sersic index (or C_re(1/3)) and mean age or metallicity, but a strong positive correlation of the shape parameters with [Mg/Fe] abundance ratio. This dependence is as strong as the [Mg/Fe] vs. velocity dispersion and C_re(1/3) vs. velocity dispersion relations. We speculate that early-type galaxies settle up their structure on time-scales in agreement with those imposed by their [Mg/Fe] ratios. This suggest that the global structure of larger galaxies, with larger [Mg/Fe] ratios and shorter time-scales, was already at place at high z, without experiencing a significant time evolution.Comment: 5 pages, 3 figures (to appear in The Astrophysical Journal Letters

Dynamics of biexciton localization in AlxGa1-xN mixed crystals under exciton resonant excitation

We report the localization dynamics of biexcitons in AlxGa1−xN mixed crystals under exciton resonant excitation at low temperatures. During a few tens of picoseconds just after intense laser excitation, the photoluminescence (PL) spectral shape obeys an inverse Maxwell–Boltzmann distribution and free biexcitons dominate the PL spectrum. With a further increase in the delay time, the biexciton PL peak energy and edge energy shift to lower energies. These redshift behaviors in AlxGa1−xN mixed crystals are completely different from the behaviors of free biexcitons in GaN crystals. Our observations reveal the rapid transformation dynamics from free to localized biexcitons in band-tail states in AlxGa1−xN mixed crystals

Temperature dependence of photoluminescence spectra of undoped and electron-doped SrTiO3: Crossover from Auger recombination to single-carrier trapping

We report unusual photoluminescence (PL) behaviors in highly photoexcited SrTiO3 crystals at low temperatures. The PL spectrum and dynamics show abrupt changes below 150 K in both nondoped and electron-doped SrTiO3 samples. We clarified that the PL dynamics in both nondoped and electron-doped SrTiO3 is well described by the same simple model involving single-carrier trapping, radiative bimolecular recombination, and nonradiative Auger recombination. The unusual temperature dependence of PL dynamics is caused by the crossover from Auger recombination at high temperatures to single-carrier trapping at low temperatures. We discuss the temperature-dependent PL dynamics in conjunction with the high carrier mobility of SrTiO3 at low temperatures

Structural analysis and proteolytic processing of recombinant G domain of mouse laminin α2 chain

AbstractFour individual LG modules from the C-terminus of the laminin α2 chain (LG1, LG2, LG4 and LG5) and combinations of these modules were prepared as recombinant products from transfected mammalian cells. This demonstrated that LG modules represent autonomously folding protein domains. Successful production depended on proper alignment of module borders and required a sequence correction at the C-terminus which added an extra cysteine. The LG modules were glycosylated and shown by electron microscopy to have a globular shape, indicating proper folding. Evidence is provided for the splicing of a 12 bp exon in LG2, although this did not impair folding. Proteolytic cleavage at the C-terminus of a basic sequence was observed close to the N-terminus of LG3. A similar processing also occurs in tissue-derived laminin-2 and -4 which contain the α2 chain

Medial prefrontal cortex and anterior cingulate cortex in the generation of alpha activity induced by transcendental meditation: a magnetoencephalographic study.

Previous EEG studies have shown that transcendental meditation (TM) increases frontal and central alpha activity. The present study was aimed at identifying the source of this alpha activity using magnetoencephalography (MEG) and electroencephalography (EEG) simultaneously on eight TM practitioners before, during, and after TM. The magnetic field potentials corresponding to TM-induced alpha activities on EEG recordings were extracted, and we attempted to localize the dipole sources using the multiple signal classification (MUSIC) algorithm, equivalent current dipole source analysis, and the multiple spatio-temporal dipole model. Since the dipoles were mapped to both the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC), it is suggested that the mPFC and ACC play an important role in brain activity induced by TM.</p

Advanced glycation end products modulate transcriptional regulation in mesangial cells

Advanced glycation end products modulate transcriptional regulation in mesangial cells. Advanced glycation end products (AGEs) stimulate synthesis of extracellular matrix (ECM) in a receptor-mediated manner on mesangial cells. In the present study, we examined the transcriptional regulation of the gene for type IV collagen [(IV)collagen], which is one of the major components of mesangial sclerosis, after stimulation of AGEs on mesangial cells. The methylation pattern of the promoter/enhancer region of (IV)collagen gene was similar in AGE-treated and control cells. AGEs significantly increased the transcriptional activity of the (IV)collagen gene, as measured by transient transaction assays using the reporter gene construct containing (IV)collagen promoter/enhancer and the chloramphenicol acetyltransferase gene. AGEs also increased smooth muscle α-actin mRNA levels as well as its transcriptional activity. Nuclear factor binding of the promoter of (IV)collagen gene was stimulated by AGEs. Furthermore, AGEs dramatically decreased the mRNA levels of (IV)collagen promoter binding protein (MSW), a larger subunit of DNA replication complex, AP1. These results suggest that AGEs increase expression of (IV)collagen gene by modulating the levels of promoter binding proteins. These transcriptional events may play a critical role in ECM accumulation in response to AGEs

Photoelectronic Responses in Solution-Processed Perovskite CH[3]NH[3]PbI[3] Solar Cells Studied by Photoluminescence and Photoabsorption Spectroscopy

Photoelectronic responses of organic-inorganic hybrid perovskite CH[3]NH[3]PbI[3] on mesoporous TiO[2] electrodes are investigated. On the basis of near-band-edge optical absorption and photoluminescence spectra, the bandgap energy and exciton binding energy as a function of temperature are obtained. The exciton binding energy is much smaller than thermal energy at room temperature, which means that most excitons are thermally dissociated, and optical processes are determined by the photoexcited electrons and holes. We determined the temperature dependence of exciton binding energy, which changes from ~30 meV at 13 K to 6 meV at 300 K. In addition, the bandgap energy and the exciton binding energy show abrupt changes at 150 K due to structural phase transition. Our fundamental optical studies provide essential information for improving the device performance of solar cells based on halide perovskite semiconductors

Characterization of muscarinic and P2X receptors in the urothelium and detrusor muscle of the rat bladder

AbstractMuscarinic and purinergic (P2X) receptors play critical roles in bladder urothelium under physiological and pathological conditions. Aim of present study was to characterize these receptors in rat bladder urothelium and detrusor muscle using selective radioligands of [N-methyl-3H]scopolamine methyl chloride ([3H]NMS) and αβ-methylene ATP [2,8-3H]tetrasodium salt ([3H]αβ-MeATP). Similar binding parameters for each radioligand were observed in urothelium and detrusor muscle. Pretreatment with N-(2-chloroethyl)-4-piperidinyl diphenylacetate (4-DAMP mustard) mustard revealed co-existence of M2 and M3 receptors, with the number of M2 receptors being larger in the urothelium and detrusor muscle. Intravesical administration of imidafenacin and Dpr-P-4 (N → O) (active metabolite of propiverine) displayed significant binding of muscarinic receptors in the urothelium and detrusor muscle. The treatment with cyclophosphamide (CYP) or resiniferatoxin (RTX) resulted in a significant decrease in maximal number of binding sites (Bmax) for [3H]NMS and/or [3H]αβ-MeATP in the urothelium and detrusor muscle. These results demonstrated that 1) pharmacological characteristics of muscarinic and P2X receptors in rat bladder urothelium were similar to those in the detrusor muscle, 2) that densities of these receptors were significantly altered by pretreatments with CYP and RTX, and 3) that these receptors may be pharmacologically affected by imidafenacin and Dpr-P-4 (N → O) which are excreted in the urine

Carcinosarcoma of the Uterine Corpus with Alpha-Fetoprotein-Producing Hepatoid Adenocarcinoma: A Report of Two Cases

We report two cases of uterine carcinosarcoma associated with alpha-fetoprotein (AFP)-producing hepatoid adenocarcinoma. Samples were obtained from two women aged 63 and 82 years. Serum AFP levels of the two samples were 10,131 and 401 ng/ml, respectively. Histologically, in both cases the tumor cells were composed of hepatoid adenocarcinoma component and sarcoma component including rhabdomyosarcoma. Immunohistochemical analyses revealed that AFP was expressed in the cytoplasm of the carcinomatous component. After surgery, the patients received six courses of carboplatin/paclitaxel chemotherapy, and the serum levels of AFP decreased to normal range. The first patient is alive and well at the 2-year follow-up, while the second patient died of disease 1 year after initial operative treatment. This is, to our knowledge, the second report of carcinosarcoma of the uterine corpus with AFP-producing hepatoid adenocarcinoma, as proven by immunohistochemical analyses