発色団の光励起に起因した多原子分子解離反応の動力学的研究

広島大学(Hiroshima University)博士(理学)Doctor of Sciencedoctora

A suitable stereoisomer of vibrioferrin probes for iron uptake of Vibrio parahaemolyticus

Suitable Stereostructures of vibrioferrin probes for iron uptake of Vibrio parahaemolyticus was revealed. Stereoisomers of dansyl labeled vibrioferrin at the 2′′-position were synthesized and their uptake activities were evaluated. Vibrio parahaemolyticus take in both isomers at the 2′′-position. In addition to Vibrio parahaemolyticus, several bacteria have also taken up the (R)-isomer

Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study

Background: Glutathione plays crucial roles in the detoxification and antioxidant systems of cells and has been used to treat acute poisoning and chronic liver diseases by intravenous injection. This is a first study examining the therapeutic effects of oral administration of glutathione in patients with nonalcoholic fatty liver disease (NAFLD). Methods: The study was an open label, single arm, multicenter, pilot trial. Thirty-four NAFLD patients diagnosed using ultrasonography were prospectively evaluated. All patients first underwent intervention to improve their lifestyle habits (diet and exercise) for 3 months, followed by treatment with glutathione (300 mg/day) for 4 months. We evaluated their clinical parameters before and after glutathione treatment. We also quantified liver fat and fibrosis using vibration-controlled transient elastography. The primary outcome of the study was the change in alanine aminotransferase (ALT) levels. Results: Twenty-nine patients finished the protocol. ALT levels significantly decreased following treatment with glutathione for 4 months. In addition, triglycerides, non-esterified fatty acids, and ferritin levels also decreased with glutathione treatment. Following dichotomization of ALT responders based on a median 12.9% decrease from baseline, we found that ALT responders were younger in age and did not have severe diabetes compared with ALT non-responders. The controlled attenuation parameter also decreased in ALT responders. Conclusions: This pilot study demonstrates the potential therapeutic effects of oral administration of glutathione in practical dose for patients with NAFLD. Large-scale clinical trials are needed to verify its efficacy. Trial registration: UMIN000011118 (date of registration: July 4, 2013)

Usefulness of FDG PET/CT derived parameters in prediction of histopathological finding during the surgery in patients with pancreatic adenocarcinoma

Purpose Pancreatic cancer is the 4th most common cause of cancer death in Japan and exhibits a 5-year overall survival rate of approximately 7%. The accurate diagnosis of pancreatic cancer is important for determining the optimal management strategy. Fludeoxyglucose-positron emission tomography (FDG PET) integrated with computed tomography (18F-FDG PET/ CT) has emerged as a powerful imaging tool for detecting and evaluating various cancers, and it is used for staging, detecting local recurrence and distant metastasis, measuring therapeutic effects,and predicting prognosis in pancreatic cancer patients. Lately, FDG PET/CT-derived parameters, such as standardized uptake values (SUV), the metabolic tumor volume (MTV), and total lesion glycolysis (TLG), have been suggested as prognostic factors for various types of cancer, including pancreatic cancer. However, there is no consensus regarding the best parameters for evaluating patient prognosis, operability, etc. The purpose of this study was to examine the differences between operable and non-operable pancreatic cancer using FDG PET/CT-derived parameters, and to investigate whether volumetric parameters (TLG and the MTV) are superior to SUV-based parameters for predicting infiltration status/determining operability. Materials and methods We conducted a retrospective study of the cases of 48 patients with clinically proven pancreatic adenocarcinoma, who underwent FDG PET/CT imaging before treatment. In the operable group, the surgical specimens were subjected to histopathological examinations, and the cases were separated into those exhibiting less and greater infiltration. SUVmax, SUVpeak, the tumor background ratio (TBR), TLG, and the MTV were compared between these groups as well as between the operable and non-operable groups.Results Venous infiltration showed significant associations with several metabolic parameters (SUVmax, SUVpeak, and the TBR). However, it did not display any significant associations with volumetric parameters, such as TLG or the MTV. None of the FDG PET/CT-derived parameters exhibited significant associations with lymphatic or neural infiltration. Significant differences in volumetric parameters, such as the MTV and TLG,were detected between the operable and non-operable subgroups. Conclusions Metabolic18F-FDG PET/CT-derived parameters,such as SUVmax, SUVpeak, and the TBR, are useful for predicting venous infiltration status in patients with operable pancreatic adenocarcinoma

Photocatalytic Current Doubling-Induced Generation of Uniform Selenium and Cadmium Selenide Quantum Dots on Titanium(IV) Oxide

We have developed a current doubling-induced two step photodeposition (CD-2PD) technique for forming selenium quantum dots (QDs) and metal selenide QDs on TiO₂, and proposed a reaction mechanism. Large aggregates of Se particles (∼100 nm) are generated on TiO₂ from aqueous and 2-methyl-2-propanol solutions of H₂SeO₃ by UV-light irradiation. In contrast, highly dispersed selenium QDs are formed on TiO₂ from the H₂SeO₃ ethanol and methanol solutions (Se/TiO₂). The mean particle size increases with an increase in irradiation time (<i>t</i>_p1) to reach 8.7 nm at <i>t</i>_p1 = 2 h. The rates of Se photodeposition in the latter solvents are much faster than those in the latter solvents. These striking differences can be attributed to the current doubling effect of ethanol and methanol by photoelectrochemical measurements. Subsequent UV-light irradiation of Se­(<i>t</i>_p1 = 20 min)/TiO₂ in ethanol and methanol solutions containing Cd²⁺ ions converts the Se QDs into homogeneous CdSe QDs (∼2 nm). The application of this <i>in situ</i> CD-2PD technique to the mesoporous TiO₂ nanocrystalline film enables the uniform incorporation of CdSe QDs into the film (CdSe/mp-TiO₂). QD-sensitized solar cells employing the CdSe/mp-TiO₂ photoanodes afford much higher power conversion efficiencies than that using a photoanode prepared in the aqueous solution

Multistep Intersystem Crossing Pathways in Cinnamate-Based UV‑B Sunscreens

The nonradiative decay pathways of jet-cooled <i>para</i>-methoxy methylcinnamate (<i>p</i>-MMC) and <i>para</i>-methoxy ethylcinnamate (<i>p</i>-MEC) have been investigated by picosecond pump–probe and nanosecond UV-Deep UV pump–probe spectroscopy. The possible relaxation pathways were calculated by the (time-dependent) density functional theory. We found that <i>p</i>-MMC and <i>p</i>-MEC at low excess energy undergo multistep intersystem crossing (ISC) from the bright S₁ (¹<i>ππ</i>*) state to the lowest triplet T₁ (³<i>ππ</i>*) state via two competing pathways through the T₂ state in the time scale of 100 ps: (a) stepwise ISC followed after the internal conversion (IC) from S₁ to the dark ¹nπ* state; (b) direct ISC from the S₁ to T₂ states. These picosecond multistep ISCs result in the torsion of CC double bond by ∼95° in the T₁ state, whose measured adiabatic energy and lifetime are 16577 cm^–1 and ∼20 ns, respectively, for <i>p</i>-MMC. These results suggest that the ISC processes play an indispensable role in the photoprotecting sunscreens in natural plants