Decarboxylation efficiency of carboxylic acids as ligands of metal oxide nanocluster resists upon γ-ray irradiation

Metal oxide nanocluster resists have recently attracted considerable attention for use in extreme ultraviolet (EUV) lithography. To obtain sophisticated guidelines for material design, it is necessary to understand well the radiation-induced chemical reaction scheme including the insolubilization mechanism. In this study, the production of CO2, which is considered to be one of the end products of treatment with an ionizing radiation, was investigated for eight types of carboxylic acid under various conditions using -rays (60Co) as a radiation source. The amount of CO2 produced was measured by gas chromatography (GC). GCO2 (/100 eV), which indicates decarboxylation efficiency, was evaluated. CO2 was generated through electron addition, hole transfer, and hydroxyl radical addition to the molecular and ionic forms of carboxylic acids. The dependences of GCO2 on reaction partners were clarified. The dependences of GCO2 on the molecular structure and dissociative state of carboxylic acids were also clarified.

Effects of Different Irradiation Treatments on Total Saponins Content of Sapindus mukorossi

Sapindus mukorossi Gaertn is also known as Mu Huanzi, You Huanzi, soap tree, etc. The pericarp of Sapindus mukorossi contains many saponins, which is a type of natural non-ionic surfactant. Its extract has vigorous surface activity and biological activities such as bacteriostasis, oxidation resistance, and free radical scavenging. The Sapindus mukorossi extract is an environmentally friendly washing product that microorganisms can be rapidly decompose in nature without any environmental pollution.This study aims to investigate the effects of E-beam and Co60-γ irradiation on the total saponins content in the crude extract of the S mukorossi. The S mukorossi powder is irradiated with E-beam and Co60-γ ray at doses of 0, 4, 6, 8, 10, and 12 kGy for E-beam and 0, 50, 100, 150, and 200 Gy, respectively, for Co60-γ ray. The changes in the content of total saponins in the crude extract, total detergency, and the bacteriostatic abilities before and after the irradiation were analyzed. The results showed that the content of total saponins in samples irradiated by E-beam was significantly higher than that in non-irradiated samples. The saponins yield was the highest at a radiation dose of 6 kGy, and the detergency and bacteriostatic ability were also the strongest. After low-dose Co6-γ irradiation, the total saponins in the S mukorossi crude extract, and detergency and bacteriostatic ability had no apparent change. Conclusion: E-beam irradiation at a dose of 6 kGy can effectively improve the content of total saponins in the crude extract of S mukorossi powder. In addition, its effects on detergency and bacteriostatic abilities are relatively significant. The findings provide sufficient reference data for the further development of S mukorossi commodities.

Validity of the γ-Ray Evaluation with iodoamphetamine for Cerebral Blood Flow Assessment (REICA) method for quantification of cerebral blood flow including acetazolamide challenge test

Objective The γ-Ray Evaluation with iodoamphetamine for Cerebral Blood Flow Assessment (REICA) is a new method for quantifying cerebral blood flow (CBF) using single-photon emission computed tomography (SPECT) and [123I]N-isopropyl-p-iodoamphetamine (123I-IMP). The present study aimed to validate the REICA method using data including acetazolamide challenge test. Methods The REICA and Graph-Plot (GP) methods were used to calculate mean CBF (mCBF) for 92 acquisitions (rest: 57, stress: 35) and cerebrovascular reactivity (CVR) in 33 patients. To obtain stress data, 15 mg/kg of acetazolamide was injected intravenously 10 min before the administration of 123I-IMP, and blood samples were collected under the same conditions as rest data. The reference standard was the Autoradiograph (ARG) method using arterial blood sampling, and the accuracy of the REICA method was analyzed by comparing it with each method. Results For mCBF, the correlation coefficients (r) were 0.792 for the REICA method and 0.636 for the GP method. For CVR, r values were 0.660 for the REICA method and 0.578 for the GP method. In both acquisitions, the REICA method had a stronger correlation with the ARG method than the GP method. For mCBF, there was a significant difference in the correlation coefficient between the two correlation coefficients (p < 0.01). Conclusions The REICA method was more accurate than the GP method in quantifying CBF and closer to the ARG method. The REICA method, which is a noninvasive method of cerebral blood flow quantification using 123I-IMP, has great medical usefulness.