The Central Gas Systems of Early-Type Galaxies Traced by Dust Feature: Based on the HST WFPC2 Archival Images

We investigated the central gas systems of E/S0 galaxies by making use of the WFPC2 images of the Hubble Space Telescope archive. We searched the gas systems that were traced by the dust with a new method of making color excess images in F555W - F814W (V-I). Out of 25 sample galaxies, we detected gas system in 14 galaxies. The dust was newly detected in two galaxies that were thought to contain no dust based on single band, pre-refurbishment data. The full extents of the gas systems are 0.1 to 3.5 kpc, and the masses of the gas, log M(gas) [M(solar)], are 4.2 to 7.2. The AGN activity is well correlated with existence of the gas systems. None of galaxies without the gas systems show the AGN activity. On the other hand, some galaxies with the gas systems show the AGN activity; optical AGN activities are shown in 5 out of 11 galaxies of which AGNs are optically studied, and radio activities are shown in 6 out of 14 galaxies. This shows that the AGN activity is driven with the gas system.Comment: gzipped tarred file containing 7 files: Tomita.tex (main text, needs aaspp4.sty), Tomita.tab[1,2].tex (tables, need aj_pt4.sty), Tomita.fig [1a,1b,1c,2].ps (PS figures). To be appeared in AJ, Vol.120, No.1 (July 2000

Capturing molecular structural dynamics by 100 ps time-resolved X-ray absorption spectroscopy

An experimental set-up for time-resolved X-ray absorption spectroscopy with 100 ps time resolution at beamline NW14A at the Photon Factory Advanced Ring is presented

Pillar[6]arene acts as a biosensor for quantitative detection of a vitamin metabolite in crude biological samples

ビタミン代謝物を迅速定量できる超分子バイオセンサーを開発. 京都大学プレスリリース. 2020-12-09.Metabolic syndrome is associated with obesity, hypertension, and dyslipidemia, and increased cardiovascular risk. Therefore, quick and accurate measurements of specific metabolites are critical for diagnosis; however, detection methods are limited. Here we describe the synthesis of pillar[n]arenes to target 1-methylnicotinamide (1-MNA), which is one metabolite of vitamin B3 (nicotinamide) produced by the cancer-associated nicotinamide N-methyltransferase (NNMT). We found that water-soluble pillar[5]arene (P5A) forms host–guest complexes with both 1-MNA and nicotinamide, and water-soluble pillar[6]arene (P6A) selectively binds to 1-MNA at the micromolar level. P6A can be used as a “turn-off sensor” by photoinduced electron transfer (detection limit is 4.38 × 10−6 M). In our cell-free reaction, P6A is used to quantitatively monitor the activity of NNMT. Moreover, studies using NNMT-deficient mice reveal that P6A exclusively binds to 1-MNA in crude urinary samples. Our findings demonstrate that P6A can be used as a biosensor to quantify 1-MNA in crude biological samples

Thymidine Catabolism as a Metabolic Strategy for Cancer Survival

Thymidine phosphorylase (TP), a rate-limiting enzyme in thymidine catabolism, plays a pivotal role in tumor progression; however, the mechanisms underlying this role are not fully understood. Here, we found that TP-mediated thymidine catabolism could supply the carbon source in the glycolytic pathway and thus contribute to cell survival under conditions of nutrient deprivation. In TP-expressing cells, thymidine was converted to metabolites, including glucose 6-phosphate, lactate, 5-phospho-α-D-ribose 1-diphosphate, and serine, via the glycolytic pathway both in vitro and in vivo. These thymidine-derived metabolites were required for the survival of cells under low-glucose conditions. Furthermore, activation of thymidine catabolism was observed in human gastric cancer. These findings demonstrate that thymidine can serve as a glycolytic pathway substrate in human cancer cells

Thymidine catabolism promotes NADPH oxidase-derived reactive oxygen species (ROS) signalling in KB and yumoto cells

Thymidine phosphorylase (TP) is a rate-limiting enzyme in the thymidine catabolic pathway. TP is identical to platelet-derived endothelial cell growth factor and contributes to tumour angiogenesis. TP induces the generation of reactive oxygen species (ROS) and enhances the expression of oxidative stress-responsive genes, such as interleukin (IL)-8. However, the mechanism underlying ROS induction by TP remains unclear. In the present study, we demonstrated that TP promotes NADPH oxidase-derived ROS signalling in cancer cells. NADPH oxidase inhibition using apocynin or small interfering RNAs (siRNAs) abrogated the induction of IL-8 and ROS in TP-expressing cancer cells. Meanwhile, thymidine catabolism induced by TP increased the levels of NADPH and intermediates of the pentose phosphate pathway (PPP). Both siRNA knockdown of glucose 6-phosphate dehydrogenase (G6PD), a rate-limiting enzyme in PPP, and a G6PD inhibitor, dihydroepiandrosterone, reduced TP-induced ROS production. siRNA downregulation of 2-deoxy-D-ribose 5-phosphate (DR5P) aldolase, which is needed for DR5P to enter glycolysis, also suppressed the induction of NADPH and IL-8 in TP-expressing cells. These results suggested that TP-mediated thymidine catabolism increases the intracellular NADPH level via the PPP, which enhances the production of ROS by NADPH oxidase and activates its downstream signalling

Comparison of the EEG between before and during sleeping by the RCE analysis

It is crucial to practically estimate the dozing like the driver dozing, because many people cannot have enough sleeping caused by irregular hour and much stress. In the conventional study, the electroencephalogram (EEG) has been a promising indicator to driver dozing. Furthermore, it is known that frequency of the EEG is highly related to the sleep and the wake conditions. Therefore, we propose to extract frequency components of the EEG from the whole cerebral cortex, by using the rhythmic component extraction (RCE), proposed by Tanaka et al. RCE extracts a component by combining multi-channel signals with weights that are optimally sought for such that the extracted component maximally contains the power in the frequency range of interest and suppresses that in unnecessary frequencies. We found difference between the features obtained by RCE in the sleep and in the wake conditions. This implies that this method is available for analyzing the sleeping.APSIPA ASC 2009: Asia-Pacific Signal and Information Processing Association, 2009 Annual Summit and Conference. 4-7 October 2009. Sapporo, Japan. Oral session: Advances in Signal Processing for Brain Data Analysis and Feature Extraction (5 October 2009)

Characterization of a Lactobacillus gasseri JCM 1131(T) Lipoteichoic Acid with a Novel Glycolipid Anchor Structure

We determined the chemical structure of lipoteichoic acid (LTA) from Lactobacillus gasseri JCM 1131(T). The repeating unit was comprised of glycerolphosphate and 2-alanylglycerolphosphate. The glycolipid anchor was tetrahexosylglycerol with two or three acyl groups. To our knowledge, this is the first demonstration of a tetrahexose structure in an LTA glycolipid anchor