REE characteristics of Yamato-82162 and -86720 meteorites and their inference to classification

Abundances of REE, Ba, Sr, Rb, K, Mg, Ca and Fe were determined for Yamato-82162 and -86720 carbonaceous chondrites by mass spectrometric isotope dilution. The CI-normalized REE abundance patterns for Y-82162 are nearly flat (0.9-1.5×CI), but show small negative Ce anomalies. A small fraction of the chondrite shows a clear light/heavy REE fractionation. The REE abundance patterns of Y-86720 are also almost flat (1.4-1.9×CI) and show positive Eu anomalies. The degree of Eu anomaly seems to correlate with the absolute abundance of the REE. For the abundances of elements other than REE, Y-82162 shows enrichments of Fe and Mg and Y-86720 displays depletions of the relatively volatile elements K and Rb. From these results, the following conclusions are obtained : (1) Y-82162 may contain a high temperature component formed in the nebula. (2) Y-82162 is classified as a CI chondrite which has experienced thermal metamorphism. (3) Y-86720 is composed of a refractory-rich component and a refractory-poor component. (4) Y-86720 cannot be strictly classified into any group but is intermediate between CM and CO chondrites

Compositions of REE, K, Rb, Sr, Ba, Mg, Ca, Fe, and Sr isotopes in Antarctic"unique" meteorites

The abundances of Mg, Ca, Fe, K, Rb, Sr, Ba, and REE in five Antarctic "unique" meteorites, acapulcoite-lodranite type, Yamato (Y)-74063,Y-74357,Y-8002,and Allan Hills (ALH)-78230,and winonaite type, Y-75300 were determined by isotope dilution mass spectrometry. The Sr isotopic compositions of Y-74063,Y-75300,Y-8002,and ALH-78230 were also measured to investigate the whole-rock Rb-Sr isotopic systematics. In terms of the REE abundance pattern, these meteorites are grouped as follows; (1) Y-74063 and ALH-78230 with chondritic REE patterns, (2) Y-74357 with light REE depletion plus alkali and alkaline earth element depletion, and (3) Y-75300 and Y-8002 with middle REE depletion (V-shaped REE pattern) plus a positive Eu anomaly). The mineralogy of these meteorites is closely related to the above REE classification. The ^Rb-^Sr age determined from \u27whole-rock samples\u27 for Y-74063,Y-75300,Y-8002,and ALH-78230 is consistent with their formation of 4.5Ga, albeit with a large uncertainty due to the blank correction. Using the mineral/liquid partition coefficients of trace elements, the petrogenetic model calculations were performed. The results give indication on the origin of these "unique" meteorites. Y-74063 and ALH-78230 could be formed through a small degree of partial melting (less than a few%) from a chondritic starting material. Y-74357 could be formed by a larger degree (12%) of partial melting. On the other hand, the V-shaped REE pattern of the third group (Y-75300 and Y-8002) could not be explained by a simple partial melting process. The V-shaped REE pattern may be explained only by assuming the solid state equilibration within a reservoir with chondritic composition. It is suggested that Y-75300 and Y-8002 might be derived from parental materials depleted in phosphate and clinopyroxene

Volatilization of alkali metals from the heated Murchison (CM2) meteorite

In order to examine volatilization processes of alkali metals at high temperature, heating experiments were carried out using a starting material prepared from Murchison (CM2) (grain-size : ∿10μm) at temperatures of 1200-1400℃ under a constant pressure of 8×10^ Torr, and heating duration up to 80min. Analyses of alkalis (Na, K, Rb), major and minor elements and petrographic examinations were performed for run products. Results show that fractional volatilization of alkali metals occurred during heating. It is suggested that the volatilization rates of alkali metals are influenced by the chemical composition of partial melt

The association between problematic internet use and neck pain among Japanese schoolteachers

Objectives: Problematic internet use (PIU) has been suggested in relation to psychological symptoms among schoolteachers, but the relationship with physical symptoms remains unclear. We examined whether PIU or longer Internet usage time is associated with neck pain in schoolteachers. Methods: We conducted a cross-sectional study among 2582 teachers aged 20 years or older (35.6% women) in Shimane and Tottori, Japan in 2018. Neck pain was defined as ≥5 points on the Neck Disability Index. The Compulsive Internet Use Scale (CIUS) was used to assess PIU. Internet usage time on weekdays and weekends was divided into five groups: 0, 1–29, 30–59, 60–119, and ≥120 min/day. Logistic regression analysis was conducted to examine the association of the CIUS score and Internet usage time on weekdays or weekends with neck pain, adjusting for sex, age, position at school, insomnia, and psychological distress. Results: We observed 800 (31.0%) teachers with neck pain. The median (interquartile range) of their CIUS scores was 7 (2, 14). A higher CIUS score was independently associated with a higher prevalence of neck pain (odds ratio of 4th vs. 1st quartiles, 1.41; 95% confidence interval, 1.06–1.87; trend P = .006). Compared with non-Internet users, Internet users on weekdays had almost double the odds of neck pain although the difference did not reach the customary level for designating statistical significance. Conclusions: In conclusion, teachers with higher scores in CIUS were associated with a higher prevalence of neck pain in Japan, suggesting adults with PIU being at risk of physical disorders

Anisotropic Optical Conductivity Accompanied by a Small Energy Gap in One-Dimensional Thermoelectric Telluride Ta4SiTe4

We investigated the optical properties of single crystals of one-dimensional telluride Ta4SiTe4, which shows high thermoelectric performance below room temperature. Optical conductivity estimated from reflectivity spectra indicates the presence of a small energy gap of 0.1-0.15 eV at the Fermi energy. At the lowest energy, optical conductivity along the Ta4SiTe4 chain is an order of magnitude higher than that perpendicular to this direction, reflecting the anisotropic electron conduction in Ta4SiTe4. These results indicate that coexistence of a very small band gap and anisotropic electron conduction is a promising strategy to develop a high-performance thermoelectric material for low temperature applications.Comment: 6 pages, 4 figure

Analysis of Serum Fatty Acids and Vitamin D with Dimension Reduction Methods

Fatty acid plays an important role in human health and fat-related diseases. A comprehensive analysis of diverse fatty acids in serum naturally results in a multi-variable, high-dimensional dataset, and, therefore, multivariate analysis, especially dimension reduction, should be considered to extract useful information. In this study, three basic dimension reduction methods including factor analysis, principal component analysis, and independent component analysis were conducted on total and free fatty acid datasets in a general Japanese population (N=545; men:women=245:300). These analyses successfully characterized fatty acid datasets, reflecting their physicochemical natures, metabolisms, and food sources. Factor analysis and principal component demonstrated the association of -3 fatty acids (20:5 and 22:6) with 25-hydroxyvitamin D3 (vitamin D), suggesting fish oil as their common source of vitamin D. We conclude that dimension reductions can serve as a useful tool to extract valuable information from complex datasets of fatty acids and vitamin D in the aspect of health care and disease control

Impact of cigarette smoking on the relationship between body mass index and coronary heart disease: a pooled analysis of 3264 stroke and 2706 CHD events in 378579 individuals in the Asia Pacific region

BACKGROUND: Elevated levels of body mass index (BMI) and smoking are well established lifestyle risk factors for coronary heart disease (CHD) and stroke. If these two risk factors have a synergistic relationship, rigorous lifestyle modification may contribute to greater reduction in cardiovascular burden than previously expected. METHODS: A pooled analysis of individual participant data from 38 cohorts, involving 378,579 participants. Hazards ratios (HRs) and 95% confidence intervals (CIs) for BMI by cigarette smoking status were estimated using Cox proportional hazard models. RESULTS: During a mean follow-up of 3.8 years, 2706 CHD and 3264 strokes were recorded. There was a log-linear, positive relationship of BMI with CHD and stroke in both smokers and non-smokers with evidence of a synergistic effect of smoking on the association between BMI and CHD only: HRs (95% CIs) associated with a 2 kg/m2 higher BMI were 1.13 (1.10-1.17) in current smokers and 1.09 (1.06-1.11) in non-smokers (p-value for interaction=0.04). CONCLUSION: Smoking amplifies the positive association between BMI and CHD but not stroke. If confirmed, these results suggest that effective strategies that target smoking cessation and weight loss are likely to have a greater impact than anticipated on reducing the burden of CHD.published_or_final_versio

血清ペプシノゲン検査に基づく胃がん発生率と有効性に関する15年間のコホート研究

Objectives : The incidence of and mortality from gastric cancer in Japan have remained high and prophylaxis is important. However, the number of the individuals undergoing gastric mass radiography has decreased in recent years because the examination has a big burden at the time of the consultation. Many studies have reported the ease and effectiveness of the pepsinogen test and a higher incidence of gastric cancer in positive groups. However, the longest survey period was 10 years. Therefore, we conducted a 15-year cohort study to examine the validity of the testing period and the incidence of gastric cancer in serum pepsinogen positive and negative groups at a private company utilizing pepsinogen test. Methods : Subjects were 4383 employees who received a pepsinogen test. Subjects were followed for 15 years. For the purpose of examining the three periods over five-, 10-, and 15-year periods, we analyzed the validity of testing during each period, carried out a log-rank test, and analyzed hazard ratio in the Cox proportional hazard model. Results : The number of individuals who developed gastric cancer during the survey was nine in the five-year negative group, 18 in the five-year positive group, 16 in the 10-year negative group, 27 in the 10-year positive group, 31 in the 15-year negative group, and 29 in the 15-year positive group. The sensitivity of testing was 0.667 over the first five years, 0.628 over 10 years, and 0.483 over 15 years, and the specificity was 0.744 over the first five years, 0.745 over 10 years, and 0.745 over 15 years. The five-year incidence of gastric cancer was 57 per 100,000 person years in the negative group and 350 per 100,000 person years in the positive group. The ten-year incidences were 53 per 100,000 person years in the negative group and 279 per 100,000 person years in the positive group. The 15-year incidence was 75 per 100,000 person years in the negative group and 231 per 100,000 person years in the positive group. The hazard ratio of the positive group toward the negative group was 4.98 over the first five years, 4.71 over 10 years, and 2.76 over 15 years (p＜0.001). Conclusions : This study clarified that the first five years after the testing showed the highest hazard ratio and validity, therefore, the validity of testing was approximately 10 years. 【目的】我が国の胃がんの死亡率及び罹患率は現在も上位であり、その予防対策は重要で ある。けれども、近年X線の胃集団検診の受診者は、受診時の負担が大きいことから減少 している。一方職域の胃がん予防対策は、法的義務が無いため、企業により様々であるが 地域同様減少している。多くの先行研究では、血清ペプシノゲン検査法が簡便で有益とし ており、陽性群に発症率が高いとしているが、調査期間は最長10年であり、15年間の調査 はなかった。そこで、一企業において15年間の“陽性群”と“陰性群”での発症率の違い と検査の有効性の期間を検討することを目的にコホート調査を行った。 【方法】ペプシノゲン検査を受診した4,383名を15年間追跡した。５年間、10年間、15年間の ３期間に区切って各期間の検査の有効性を算出し、発症率をLog-rankで検定し、発症危険 度をCox比例ハザードで分析した。 【結果】追跡期間中に陰性群と陽性群のそれぞれの胃がん発症数は、５年間で９人と18人、 10年間で16人と27人、15年間で31人と29人であった。検査の感度は５年間で0.667、10年間 で0.628、15年間で0.483であり、特異度は、５年間で0.744、10年間で0.745，15年間で0.745 であった。発症率では、５年間の陰性群と陽性群で57、350per 100,000 person yearsであり、 10年では53、279 per 100,000 person years であり、15年では 75、231 per 100,000 person yearsであった。陰性群に対する陽性群の発生危険度は、５年間4.98、10年間4.71、15年間 2.76であった (p＜0.001)。 【結論】胃がんの発症率及び発症危険度や検査の有効性が最も高かったのは、2000年まで の５年間であり、検査の有効性は、約10年であることが明らかになった。Thesis of Takami Okuno / 奥野 敬生 博士論文 金沢大学医薬保健学総合研究科（保健学専攻

Contribution of visceral adiposity and insulin resistance to metabolic risk factors in Japanese men

金沢大学大学院医学系研究科北陸中央病院内科We investigated the relative impacts of visceral adiposity and insulin resistance on the metabolic risk profile in middle-aged Japanese men. A cross-sectional study was conducted in 636 nondiabetic Japanese men with a mean age of 51.6 years. Visceral adipose tissue (AT) was assessed using computed tomography, and insulin resistance was determined by the homeostasis model assessment of insulin resistance (HOMA-IR). Metabolic risk factors were diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III metabolic syndrome criteria: (1) hypertriglyceridemia, (2) low high-density lipoprotein cholesterol, (3) hypertension, (4) impaired fasting glucose, and (5) impaired glucose tolerance. Visceral AT and HOMA-IR were significantly and positively correlated with each other (r = 0.41, P < .001). Using the 75th percentile value as a cut point, those with isolated large visceral AT showed significantly greater odds ratios for each of the 5 risk factors measured except impaired fasting glucose, whereas those with isolated high HOMA-IR showed significantly greater odds ratios for each of the 5 risk factors except hypertriglyceridemia and impaired glucose tolerance, compared with the control group. The combined group (increased visceral AT and HOMA-IR) had the highest odds ratios for all studied risk factors. On logistic regression analysis using visceral AT and HOMA-IR as continuous independent variables, they were each independently associated with most of the metabolic risk factors and their clustering. In conclusion, neither visceral AT nor HOMA-IR stands out as the sole driving force of the risk profile; each makes a significant contribution to metabolic abnormalities in Japanese men. © 2010 Elsevier Inc. All rights reserved