Atmospheric occurrence of particle-associated nitrotriphenylenes via gas-phase radical-initiated reactions observed in South Osaka, Japan

Nitrotriphenylenes (NTPs), which include the highly mutagenic isomer 2-nitrotriphenylene (2-NTP), have been detected in airborne particles. From a public hygienic point of view, it is necessary to study the environmental occurrence of NTPs in detail. In this study, concentrations of five nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) including NTPs in airborne particles and of nitrogen oxides (NOx; NO+NO₂) and carbon monoxide (CO), at a location in South Osaka, Japan, were measured at 3 h intervals. It was found that the diurnal variations in the concentrations of 1-nitropyrene (1-NP), NOx, and CO were similar, being high early in the morning and late in the evening. This finding indicates that the occurrence of 1-NP is affected significantly by primary emissions, particularly by automotive emissions. The concentration change in 1-nitrotriphenylene was similar to that of 2-nitropyrene produced by an atmospheric OH radicalinitiated reaction. On the contrary, the variations in the concentrations of 2-nitrofluoranthene (2-NF) and 2-NTP were significantly different from those of the other nitro-PAHs, i.e., their concentrations increased during the nighttime, suggesting that neither 2-NF nor 2-NTP was emitted from the primary sources, but were formed via the NO₃ radicalinitiated nitration of the parent fluoranthene and triphenylene (TP) in the atmosphere. Based on the ambient concentration of 2-NTP and the reported rate constant for the reaction of TP with NO3 radicals, the yield of 2-NTP from the gas-phase NO₃ radical-initiated reaction of TP was estimated to be 23%

Evaluation of Oxidative Potential of Pyrenequinone Isomers by the Dithiothreitol (DTT) Assay

Atmospheric quinoid polycyclic aromatic hydrocarbons (PAHQs) have adverse health effects as redox-active species in particulate matter (PM). Several PAHQs are known to be very reactive in the dithiothreitol (DTT) assay; however, it is unclear if pyrenequinones, their parent pyrene is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) in the atmosphere, contribute to the loss of DTT in PM extracts. Herein, by employing the DTT assay, we evaluated oxidative potentials of three pyrenequinone isomers (4, 5-pyrenequinone [4, 5-PyQ] and a mixture of 1, 6-/1, 8-pyrenequinones [1, 6-/1, 8-PyQ]), along with 9, 10-phenanthrenequinone (PQN), 1, 2-naphthoquinone (1, 2-NQ), and 1, 4-naphthoquinone (1, 4-NQ), of which DTT loss rates were examined previously. Our results demonstrate that the DTT consumption by ortho-type PAHQs is fast, particularly by 4, 5-PyQ. The order of DTT loss rate by the PAHQs tested in this study was as follows: 4, 5-PyQ ∼ PQN > 1, 2-NQ > 1, 4-NQ ∼ 1, 6-/1, 8-PyQ. 4, 5-PyQ was confirmed to be active in the DTT assay for the first time in this study. The DTT consumption rate by 4, 5-PyQ is 14.6 ± 0.8 mol/min/PAHQ-mol, which is comparable to that of PQN (14.4 ± 0.1 mol/min/PAHQ-mol) known as the most active PAHQs by the DTT assay so far

Reduced uremic metabolites are prominent feature of sarcopenia, distinct from antioxidative markers for frailty

Due to global aging, frailty and sarcopenia are increasing. Sarcopenia is defined as loss of volume and strength of skeletal muscle in elderlies, while frailty involves multiple domains of aging-related dysfunction, impaired cognition, hypomobility, and decreased social activity. However, little is known about the metabolic basis of sarcopenia, either shared with or discrete from frailty. Here we analyzed comprehensive metabolomic data of human blood in relation to sarcopenia, previously collected from 19 elderly participants in our frailty study. Among 131 metabolites, we identified 22 sarcopenia markers, distinct from 15 frailty markers, mainly including antioxidants, although sarcopenia overlaps clinically with physical frailty. Notably, 21 metabolites that decline in sarcopenia or low SMI are uremic compounds that increase in kidney dysfunction. These comprise TCA cycle, urea cycle, nitrogen, and methylated metabolites. Sarcopenia markers imply a close link between muscle and kidney function, while frailty markers define a state vulnerable to oxidative stress

Anomalous Relations among Various Performance Objectives

Abstract Distributed computer systems consist of a set of heterogeneous host computers (i.e., nodes) connected by a communication network. A job that arrives at a node may either be processed locally or transferred to another node for remote processing, which we call load balancing. One possible performance objective of load balancing in distributed computer systems is to minimize the overall mean response time. We can characterize analytically the static load balancing policy whereby the mean overall response time is minimized, which we call the overall optimal policy. This policy, however, lacks fairness in the sense that, for example, two jobs arriving at the same node but being forwarded to different nodes may not have the same expected response time. To satisfy fairness among jobs we can consider an individually optimal load balancing policy whereby jobs arriving at the same node have the same (minimum) expected response time regardless of the nodes which process them. Furthermore, we can think of a node optimal load balancing policy whereby the mean response time of jobs arriving at each node is minimum given the decision by the other nodes of which jobs arriving at those nodes are forwarded. We report the existence of some seemingly anomalous phenomena in the mutual relation among the above policies

Determining the rate constants for the gas-phase reactions of low-volatile compounds with radical using a relative-rate method in CCL4 liquid phase-system

大阪府立大学Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

Determination of 1-nitropyrene in low volume ambient air samples by high-performance liquid chromatography with fluorescence detection

金沢大学医薬保健研究域薬学系To measure the actual exposure of a person to 1-nitropyrene (1-NP) in airborne particulate matter, it is considered more accurate to collect air samples with a portable air sampler than to sample at a fixed location. However, because the portable samplers can sample only small volumes, a sensitive method is needed to analyze the compounds that are collected on a filter. Here we describe a high-performance liquid chromatographic (HPLC) method with fluorescence detection that is sensitive and precise enough for use with portable air samplers. The developed column-switching system successfully removed the interfering substances in the samples with only a simple pretreatment. To improve the precision of the measurement, deuterated 1-NP was used as an internal standard, and it eluted immediately prior to 1-NP with sufficient resolution (Rs, 1.50). The detection limit was 0.32 fmol/injection, and the calibration range was from 2 to 100 fmol. The proposed method was applied to determining 1-NP in fine airborne particulate matter (PM2.5) at two sites with low pollution levels. 1-NP was detected in all samples at concentrations in the low fmol/m3 range. The proposed method has enough sensitivity and precision to determine 1-NP in the limited air volume of the portable sampler. © 2009 Elsevier B.V. All rights reserved

Study on formation processes of nitrated polycyclic aromatic hydrocarbons in the atmosphere

大阪府立大学 /　金沢大学大学院自然科学研究科Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

Long-range transportation of polyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons from China to Japan

金沢大学大学院自然科学研究科Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

Analysis of 8-hydroxy-2\u27-deoxyguanosine in human urine using hydrophilic interaction chromatography with tandem mass spectrometry

Urinary 8-hydroxy-2\u27-deoxyguanosine (8-OHdG) is a widely used noninvasive biomarker of oxidative stress. A selective, sensitive and rapid method for determining 8-OHdG in human urine was developed using hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) with electrospray ionization. 8-OHdG and isotopically labeled 8-OHdG (internal standard) were separated on a HILIC column with a mobile phase of 10. mM ammonium acetate: acetonitrile (1:9, v/v) within 10. min and detected by using a positive electrospray ionization interface under the selected reaction monitoring mode. The detection limits of 8-OHdG (corresponding to a signal-to-noise ratio of 3) for the HILIC-MS/MS system and the conventional method using a reversed-phase column with MS/MS were 1.0 and 26.0. fmol/injection, respectively. The proposed method makes it possible to monitor the basal level of urinary 8-OHdG from non-exposed healthy subjects and can be used for large-scale human studies. © 2012 Elsevier B.V