Japan Chemical Analysis Center

For small molecules with large rotational constants, knowing the relative intensities of the ro-vibrational transitions can be used to determine the temperature within a gas plume. We demonstrate the use of carbon monoxide (CO) as an in situ spectroscopic probe of gas plume temperature by application of both laboratory and standoff Fourier transform infrared spectroscopy to monitor the CO spectral response at different temperatures. The measured CO rotational contours were analyzed using a simple Boltzmann model to deduce the population distribution of the J-levels, from which the in-plume temperature is deduced. The method was vetted by comparing calculated temperatures to both static laboratory measurements of known temperatures, as well as field measurements using a simulated smokestack release. The calculated and laboratory values agreed to within 1 °C. For the smokestack experiments, the spectroscopically deduced temperatures were compared to readings from a series of thermocouples placed at strategically sampled distances along the plume trajectory. Both the spectroscopically derived as well as the thermocouple-measured temperatures revealed a rapid cooling of the plume, with the infrared thermometry values displaying greater temperature values which are believed to better represent the actual plume temperatures.

ABSTRACT Previously we reported a simple algorithmic method of spectral determination method (SDM), which is based on the first principle that a γ-ray spectrum obtained for a sample is a linear superposition of individual spectra of the radioactive nuclides included in the sample and demonstrated that the method is valid for γ-ray determination. Here, we apply it to the spectra obtained by liquid scintillation counter (LSC). In LSC measurements quenching is generally observed, and we at first developed its correction method to standard spectra. The SDM code reported in the previous investigation is used to analyze the LSC spectra. Based on the analyses done by using the measured spectra, we concluded that the SDM method is valid in the LSC spectra similarly to the γ-ray spectra studied in the previous investigation.

We performed multigenerational tests to clarify the chemical tolerance mechanisms of a nontarget aquatic organism, Daphnia magna. We continuously exposed D. magna to a carbamate insecticide (pirimicarb) at lethal or sublethal concentrations (0, 3.8, 7.5, and 15 μg/L) for 15 generations (F0-F14). We then determined the 48 h-EC50 values and mRNA expression levels of acetylcholinesterase, glutathione S-transferase, and ATP (Adenosine triphosphate)-binding cassette transporter (ABCt) in neonates (<24 h old) from F0, F4, F9, and F14. To ascertain the effects of DNA methylation on pirimicarb sensitivity, we measured 5-methylcytosine levels (DNA methylation levels) in neonates of parents in the last generation (F14). In addition, we cultured groups exposed to 0 and 7.5 μg/L (the latter of which acquired chemical tolerance to pirimicarb) with or without 5-azacytidine (de-methylating agent) and determined methylation levels and 48 h-EC50 values in neonates (<24 h old) from the treated parents. The EC50 values (30.3-31.6 μg/L) in F14 of the 7.5 and 15 μg/L groups were approximately two times higher than that in the control (16.0 μg/L). A linear mixed model analysis showed that EC50 and ABCt mRNA levels were significantly increased with generational alterations; further analysis showed that the ABCt mRNA level was positively related to the EC50 . Therefore, ABCt may be associated with altered pirimicarb sensitivity. In addition, the EC50 value and DNA methylation levels in pirimicarb-tolerant clones decreased after exposure to 5-azacytidine, suggesting that DNA methylation contributes to chemical tolerance. These findings improved our knowledge regarding the acquisition of chemical tolerance in aquatic organisms.

Plasma xanthine oxidoreductase (XOR) activity in patients with cardiopulmonary arrest (CPA) has not yet been studied.A total of 1,158 patients who required intensive care and 231 control patients who attended a cardiovascular outpatient clinic were prospectively analyzed. Blood samples were collected within 15 minutes of admission from patients in intensive care patients, which were divided into a CPA group (n = 1,053) and a no-CPA group (n = 105). Plasma XOR activity was compared between the 3 groups and factors independently associated with extremely elevated XOR activity were identified using a multivariate logistic regression model. Plasma XOR activity in the CPA group (median, 1,030.0 pmol/hour/mL; range, 233.0-4,240.0 pmol/hour/mL) was significantly higher than in the no-CPA group (median, 60.2 pmol/hour/mL; range, 22.5-205.0 pmol/hour/mL) and control group (median, 45.2 pmol/hour/mL; range, 19.3-98.8 pmol/hour/mL). The regression model showed that out-of-hospital cardiac arrest (OHCA) (yes, odds ratio [OR]: 2.548; 95% confidence interval [CI]: 1.098-5.914; P = 0.029) and lactate levels (per 1.0 mmol/L increase, OR: 1.127; 95% CI: 1.031-1.232; P = 0.009) were independently associated with high plasma XOR activity (≥ 1,000 pmol/hour/mL). Kaplan-Meier curve analysis indicated that the prognosis, including all-cause death within 30 days, was significantly poorer in high-XOR patients (XOR ≥ 6,670 pmol/hour/mL) than in the other patients.Plasma XOR activity was extremely high in patients with CPA, especially in OHCA. This would be associated with a high lactate value and expected to eventually lead to adverse outcome in patients with CPA.

To determine the background radiation level in an area affected by the Fukushima Daiichi nuclear power plant accident in 2011, natural terrestrial gamma rays had been measured using portable germanium detectors repeatedly from 2013 through 2019, at 370 locations within an area of 80 km radius around the Fukushima Daiichi nuclear power plant. At these locations, radioactive 238U, 232Th, and 40K concentrations in soil and air kerma rates at a height of 1 m above the ground due to terrestrial gamma rays were obtained by the method indicated in ICRU report 53. The average 238U, 232Th, and 40K concentrations were 18.8 (standard deviation, SD: 6.37), 22.7 (SD: 11.7), and 428 (SD: 163) Bq/kg, respectively, and the average air kerma rate over the area was found to be 0.0402 (SD: 0.0146) μGy/h. The obtained air kerma rates were compared with those reported in the literature. It was confirmed that the measured data positively correlated with each other with a regression coefficient close to one and agreed within a factor of two. A trend similar to that in previous findings was observed, that is, the air kerma rates at locations geologically classified as granite and rhyolite zones were statistically significantly higher than those at other locations.

ABSTRACTConcentrations of humic substance (HS) in deep groundwater from sedimentary formations were determined by the carbon concentration-based DAX-8 resin isolation technique. The groundwater samples were collected from test galleries at depths of 140, 250 and 350 m at the Horonobe Underground Research Laboratory (URL) in Hokkaido, and two observation wells with different depths of 560 and 1050 m in Niigata, Japan. The analytical condition was optimized for the groundwater samples with a high salinity and a high concentration of dissolved organic matters (DOMs). The analytical results showed that the HS concentrations varied from 7.8 to 23.5 mg-C dm−3, depending on the depth and the area. The HS proportions to DOM (%HS) were evaluated to be 58 – 67% and slightly decreased in the deeper groundwater. The regression analysis showed that the HS concentrations are positively correlated with the DOM concentrations. In addition, the low deviation of the %HS values from the slope in the regression equation indicated that the slight variation of %HS can be trivial in the prediction of the concentration of HS. In previous studies, HS concentrations in the groundwater had been determined with a large uncertainty and potential usage of the regression equation for the prediction had not been elucidated. Therefore, the results in this study can provide useful information on the HS concentration and its prediction from the DOM concentration in deep groundwater from sedimentary formations.

Accurate molecular modeling reveal the surprisingly large impact of the solid-state environment on the electron acceptor levels of molecular dopants.

Fluorescent silica nanoparticles, which encapsulated dye DCF-BYT with thermally activated delayed fluorescence (TADF) were fabricated by a simple synthetic method. Even in the atmospheric aqueous environment, the obtained DCF-BYT nanoparticles exhibited extremely long TADF lifetime up to 9.33 ms, which imparts these nanoparticles with great potential in biological applications, like time-resolved fluorescence imaging.

BackgroundThe standard method for personal identification and verification of urine samples in doping control is short tandem repeat (STR) analysis using nuclear DNA (nDNA). The DNA concentration of urine is very low and decreases under most conditions used for sample storage; therefore, the amount of DNA from cryopreserved urine samples may be insufficient for STR analysis. We aimed to establish a multiplexed assay for urine mitochondrial DNA typing containing only trace amounts of DNA, particularly for Japanese populations.MethodsA multiplexed suspension-array assay using oligo-tagged microspheres (Luminex MagPlex-TAG) was developed to measure C-stretch length in hypervariable region 1 (HV1) and 2 (HV2), five single nucleotide polymorphisms (SNPs), and one polymorphic indel. Based on these SNPs and the indel, the Japanese population can be classified into five major haplogroups (D4, B, M7a, A, D5). The assay was applied to DNA samples from urine cryopreserved for 1 - 1.5 years (n = 63) and fresh blood (n = 150).ResultsThe assay with blood DNA enabled Japanese subjects to be categorized into 62 types, exhibiting a discriminatory power of 0.960. The detection limit for cryopreserved urine was 0.005 ng of nDNA. Profiling of blood and urine pairs revealed that 5 of 63 pairs showed different C-stretch patterns in HV1 or HV2.ConclusionsThe assay described here yields valuable information in terms of the verification of urine sample sources employing only trace amounts of recovered DNA. However, blood cannot be used as a reference sample.