138 research outputs found

    Reaction Kinetics of Meisenheimer σ-Complex Formation between 2,4,6-Trinitrophenyl Chloride and Hydroxide Ion in Cationic Micellar Solution

    Get PDF
    Kinetic study was carried out by using stopped-flow method for the Meisenheimer σ-complex formation reaction between 2,4,6-trinitrophenyl chloride (picryl chloride: Pic-Cl) and hydroxide in aqueous cationic micellar solutions of dodecyltrimethylammonium bromide (DTAB), myristyltrimethylammonium bromide (MyTAB) and cetyltrimethyl-ammonium bromide (CTAB) dissolved in aqueous solution, for the purpose of elucidating the influence of the microscopic heterogeneity of reaction field on activation parameters. The reaction rate analysis based on a pseudo-phase ion exchange model led us to a conclusion that on the activation process the enthalpy-entropy compensation relationships worked over the wide range of surfactant concentration, and that, for the reaction occurring at the micellar surface, a reactant molecule effective to the reaction had to move into some restricted direction

    Effect of Cationic Micellar Reaction Field on Reaction Kinetics of Meisenheimer σ-Complex Formation between 1,3,5-Trinitrobenzene and Hydroxide Ion

    Get PDF
    Kinetic studies were done by using stopped-flow method for the Meisenheimer σ-complex formation reaction between 1,3,5-trinitrobenzene (TNB) and hydroxide ion in cationic micellar solutions of dodecyl-trimethylammonium bromide (DTAB), myristyltrimethylammonium bromide (MyTAB) and cetyltrimethylammonium bromide (CTAB) dissolved in aqueous solution, for the purpose of elucidating the influence of the microscopic heterogeneity of reaction field. The reaction rate analysis based on a pseudo-phase ion exchange model led us to a conclusion that the partition of reactant molecules between the micelle and water phase, and ion exchange between hydroxide ion and bromide ion existing as counter ions of cationic micellar surface were important. On the activation process, the enthalpy-entropy compensation relationships worked over the wide range of surfactant concentration. The derived isokinetic temperature, T_ revealed that in CTAB the reaction might be of enthalpy-control, and that in MyTAB be of entropy-control

    CO(J=1-0) Mapping Survey of 64 Galaxies in the Fornax Cluster with the ALMA Morita Array

    Get PDF
    We conduct a 12C16O(J = 1−0) (hereafter CO) mapping survey of 64 galaxies in the Fornax cluster using the Atacama Large Millimeter/submillimeter Array Morita array in cycle 5. CO emission is detected from 23 out of the 64 galaxies. Our sample includes dwarf, spiral, and elliptical galaxies with stellar masses of Mstar ∼ 106.3−11.6 Me. The achieved beam size and sensitivity are 15″ × 8″ and ∼12 mJy beam−1 at the velocity resolution of ∼10 km s−1, respectively. We study the cold gas (molecular and atomic gas) properties of 38 subsamples with Mstar > 109 Me combined with literature H I data. We find that (1) the low star formation (SF) activity in the Fornax galaxies is caused by the decrease in the cold gas mass fraction with respect to stellar mass (hereafter, gas fraction) rather than the decrease of the SF efficiency from the cold gas; (2) the atomic gas fraction is more heavily reduced than the molecular gas fraction of such galaxies with low SF activity. A comparison between the cold gas properties of the Fornax galaxies and their environmental properties suggests that the atomic gas is stripped tidally and by the ram pressure, which leads to the molecular gas depletion with an aid of the strangulation and consequently SF quenching. Preprocesses in the group environment would also play a role in reducing cold gas reservoirs in some Fornax galaxies.Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of ScienceGrants-in-Aid for Scientific Research (KAKENHI) 16H02158 JP17K14259 18H03717 19K03937 19J40004 19H01931 19H05076 20H05861 21H01128 21H04496Sumitomo Foundation 180923Collaboration Funding of the Institute of Statistical Mathematics "New Development of the Studies on Galaxy Evolution with a Method of Data Science"Ministry of Science and Innovation, Spain (MICINN) Spanish Government BG20/00224 MCIN/AEI PID2020-114414GB-100 PID2020-113689GB-I00Junta de Andalucia P20_00334FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades A-FQM-510-UGR20European Research Council (ERC) 679627 882793Australian Research Council CE170100013Korea Astronomy and Space Science Institute - Korean government (MSIT) 2022-1- 840-05National Aeronautics & Space Administration (NASA

    Transcriptome Analyses of a Salt-Tolerant Cytokinin-Deficient Mutant Reveal Differential Regulation of Salt Stress Response by Cytokinin Deficiency

    Get PDF
    Soil destruction by abiotic environmental conditions, such as high salinity, has resulted in dramatic losses of arable land, giving rise to the need of studying mechanisms of plant adaptation to salt stress aimed at creating salt-tolerant plants. Recently, it has been reported that cytokinins (CKs) regulate plant environmental stress responses through two-component systems. A decrease in endogenous CK levels could enhance salt and drought stress tolerance. Here, we have investigated the global transcriptional change caused by a reduction in endogenous CK content under both normal and salt stress conditions. Ten-day-old Arabidopsis thaliana wild-type (WT) and CK-deficient ipt1,3,5,7 plants were transferred to agar plates containing either 0 mM (control) or 200 mM NaCl and maintained at normal growth conditions for 24 h. Our experimental design allowed us to compare transcriptome changes under four conditions: WT-200 mM vs. WT-0 mM, ipt1,3,5,7-0 mM vs. WT-0 mM, ipt1,3,5,7-200 mM vs. ipt1,3,5,7-0 mM and ipt1,3,5,7-200 mM vs. WT-200 mM NaCl. Our results indicated that the expression of more than 10% of all of the annotated Arabidopsis genes was altered by CK deficiency under either normal or salt stress conditions when compared to WT. We found that upregulated expression of many genes encoding either regulatory proteins, such as NAC, DREB and ZFHD transcription factors and the calcium sensor SOS3, or functional proteins, such as late embryogenesis-abundant proteins, xyloglucan endo-transglycosylases, glycosyltransferases, glycoside hydrolases, defensins and glyoxalase I family proteins, may contribute to improved salt tolerance of CK-deficient plants. We also demonstrated that the downregulation of photosynthesis-related genes and the upregulation of several NAC genes may cause the altered morphological phenotype of CK-deficient plants. This study highlights the impact of CK regulation on the well-known stress-responsive signaling pathways, which regulate plant adaptation to high salinity as well as other environmental stresses

    Breathing chest radiography using a dynamic flat-panel detector combined with computer analysis

    Get PDF
    金沢大学大学院医学系研究科保健学専攻Kinetic information is crucial when evaluating certain pulmonary diseases. When a dynamic flat-panel detector (FPD) can be used for a chest examination, kinetic information can be obtained simply and cost-effectively. The purpose of this study was to develop methods for analyzing respiratory kinetics, such as movement of the diaphragm and lung structures, and the respiratory changes in x-ray translucency in local lung fields. Postero- anterior dynamic chest radiographs during respiration were obtained with a modified FPD, which provided dynamic chest radiographs at a rate of 3 frames/s. Image registration for correction of physical motion was followed by measurement of the distance from the lung apex to the diaphragm. Next, we used a cross-correlation technique to measure the vectors of respiratory movement in specific lung areas. Finally, the average pixel value for a given local area was calculated by tracing the same local area in the lung field. This method of analysis was used for six healthy volunteers and one emphysema patient. The results reported here represent the initial stage in the development of a method that may constitute a new method for diagnosing certain pulmonary diseases, such as chronic obstructive pulmonary disease, fibroid lung, and pneumonia. A clinical evaluation of our method is now in progress. (C) 2004 American Association of Physicists in Medicine

    Pulmonary blood flow evaluation using a dynamic flat-panel detector: Feasibility study with pulmonary diseases

    Get PDF
    金沢大学医薬保健研究域保健学系Purpose: Pulmonary ventilation and circulation dynamics are reflected on fluoroscopic images as changes in X-ray translucency. The purpose of this study was to investigate the feasibility of non-contrast functional imaging using a dynamic flat-panel detector (FPD). Methods: Dynamic chest radiographs of 20 subjects (abnormal, n = 12; normal, n = 8) were obtained using the FPD system. Image analysis was performed to get qualitative perfusion mapping image; first, focal pixel value was defined. Second, lung area was determined and pulmonary hilar areas were eliminated. Third, one cardiac cycle was determined in each of the cases. Finally, total changes in pixel values during one cardiac cycle were calculated and their distributions were visualized with mapping on the original image. They were compared with the findings of lung perfusion scintigraphy. Results: In all normal controls, the total changes in pixel value in one cardiac cycle decreased from the hilar region to the peripheral region of the lung with left-right symmetric distribution. In contrast, in many abnormal cases, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on a mapping image. The findings of mapping image coincided with those of lung perfusion scintigraphy. Conclusions: Dynamic chest radiography using an FPD system with computer analysis is expected to be a new type of functional imaging, which provides pulmonary blood flow distribution additionally. © CARS 2009

    Development of pulmonary blood flow evaluation method with a dynamic flat-panel detector: quantitative correlation analysis with findings on perfusion scan

    Get PDF
    金沢大学医薬保健研究域保健学系Pulmonary blood flow is reflected in dynamic chest radiographs as changes in X-ray translucency, i.e., pixel values. Thus, decreased blood flow should be observed as a reduction of the variation of X-ray translucency. We performed the present study to investigate the feasibility of pulmonary blood flow evaluation with a dynamic flat-panel detector (FPD). Sequential chest radiographs of 14 subjects were obtained with a dynamic FPD system. The changes in pixel value in each local area were measured and mapped on the original image by use of a gray scale in which small and large changes were shown in white and black, respectively. The resulting images were compared to the findings in perfusion scans. The cross-correlation coefficients of the changes in pixel value and radioactivity counts in each local area were also computed. In all patients, pulmonary blood flow disorder was indicated as a reduction of changes in pixel values on the mapping image, and a correlation was observed between the distribution of changes in pixel value and those in radioactivity counts (0.7 ≤ r, 3 cases; 0.4 ≤ r < 0.7, 7 cases; 0.2 ≤ r < 0.4, 4 cases). The results indicated that the distribution of changes in pixel value could provide a relative measure related to pulmonary blood flow. The present method is potentially useful for evaluating pulmonary blood flow as an additional examination in conventional chest radiography. © 2009 Japanese Society of Radiological Technology and Japan Society of Medical Physics

    Bioavailability of prenyl quercetin

    Get PDF
    Prenyl flavonoids are widely distributed in plant foods and have attracted appreciable attention in relation to their potential benefits for human health. Prenylation may enhance the biological functions of flavonoids by introducing hydrophobic properties in their basic structures. Previously, we found that 8-prenyl naringenin exerted a greater preventive effect on muscle atrophy than nonprenylated naringenin in a mouse model. Here, we aimed to estimate the effect of prenylation on the bioavailability of dietary quercetin (Q). The cellular uptake of 8-prenyl quercetin (PQ) and Q in Caco-2 cells and C2C12 myotube cells was examined. Prenylation significantly enhanced the cellular uptake by increasing the lipophilicity in both cell types. In Caco-2 cells, efflux of PQ to the basolateral side was <15% of that of Q, suggesting that prenylation attenuates transport from the intestine to the circulation. After intragastric administration of PQ or Q to mice or rats, the area under the concentration-time curve for PQ in plasma and lymph was 52.5% and 37.5% lower than that of Q, respectively. PQ and its O-methylated form (MePQ) accumulated at much higher amounts than Q and O-methylated Q in the liver (Q: 3400%; MePQ: 7570%) and kidney (Q: 385%; MePQ: 736%) of mice after 18 d of feeding. These data suggest that prenylation enhances the accumulation of Q in tissues during long-term feeding, even though prenylation per se lowers its intestinal absorption from the diet

    Label-free multiphoton excitation imaging as a promising diagnostic tool for breast cancer

    Get PDF
    Histopathological diagnosis is the ultimate method of attaining the final diagnosis; however, the observation range is limited to the two-dimensional plane, and it requires thin slicing of the tissue, which limits diagnostic information. To seek solutions for these problems, we proposed a novel imaging-based histopathological examination. We used the multiphoton excitation microscopy (MPM) technique to establish a method for visualizing unfixed/unstained human breast tissues. Under near-infrared ray excitation, fresh human breast tissues emitted fluorescent signals with three major peaks, which enabled visualizing the breast tissue morphology without any fixation or dye staining. Our study using human breast tissue samples from 32 patients indicated that experienced pathologists can estimate normal or cancerous lesions using only these MPM images with a kappa coefficient of 1.0. Moreover, we developed an image classification algorithm with artificial intelligence that enabled us to automatically define cancer cells in small areas with a high sensitivity of ≥0.942. Taken together, label-free MPM imaging is a promising method for the real-time automatic diagnosis of breast cancer.This is the pre-peer reviewed version of the following article:Matsui T., Iwasa A., Mimura M., et al. Label-free multiphoton excitation imaging as a promising diagnostic tool for breast cancer. Cancer Science 113, 2916 (2022), which has been published in final form at https://doi.org/10.1111/cas.15428. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
    corecore