Search

Context Interpretation of thyroid function tests during pregnancy is limited by the generalizability of reference intervals between cohorts due to inconsistent methodology. Objective (1) To provide an overview of published reference intervals for thyrotropin (TSH) and free thyroxine (FT4) in pregnancy, (2) to assess the consequences of common methodological between-study differences by combining raw data from different cohorts. Methods (1) Ovid MEDLINE, EMBASE, and Web of Science were searched until December 12, 2021. Studies were assessed in duplicate. (2) The individual participant data (IPD) meta-analysis was performed in participating cohorts in the Consortium on Thyroid and Pregnancy. Results (1) Large between-study methodological differences were identified, 11 of 102 included studies were in accordance with current guidelines; (2) 22 cohorts involving 63 198 participants were included in the meta-analysis. Not excluding thyroid peroxidase antibody–positive participants led to a rise in the upper limits of TSH in all cohorts, especially in the first (mean +17.4%; range +1.6 to +30.3%) and second trimester (mean +9.8%; range +0.6 to +32.3%). The use of the 95th percentile led to considerable changes in upper limits, varying from –10.8% to –21.8% for TSH and –1.2% to –13.2% for FT4. All other additional exclusion criteria changed reference interval cut-offs by a maximum of 3.5%. Applying these findings to the 102 studies included in the systematic review, 48 studies could be used in a clinical setting. Conclusion We provide an overview of clinically relevant reference intervals for TSH and FT4 in pregnancy. The results of the meta-analysis indicate that future studies can adopt a simplified study setup without additional exclusion criteria.

The stable isotope ratios of carbon and nitrogen (δ13C and δ15N) were measured in composite samples of Japanese food and hair. Three hundred eighty-nine foodstuffs were collected in Tokyo and Gunma Prefecture, Japan, in 2020. The foodstuffs were classified into 15 food categories, prepared as usually consumed, and mixed to make 15 composite samples representing each of the food categories. Similarly prepared samples for foodstuffs collected in 2011 and 2015 were also examined. Composite hair samples were collected from a barber shop in Tokyo and a beauty salon in Gunma in 2019. The δ13C and δ15N values of the food and hair composites were measured by elemental analyzer/isotope ratio mass spectrometry after defatting. The δ13C and δ15N values of the food composite varied from composite to composite and according to year of collection. The whole-diet δ13C values were -21.1, -22.0, and -21.5 ‰ for the 2011, 2015, and 2020 samples, respectively; the δ15N values were 5.0, 4.4, and 4.4 ‰, respectively. Diet-hair offset values of δ13C and δ15N were calculated to be 1.9 and 4.3 ‰ for δ13C and δ15N, respectively. These offset values will be important for dietary analysis and nutritional research using hair isotope ratios.

Telomere length is thought to be a biomarker of biological aging. This study examined whether telomere length was associated with urinary concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative stress, and antioxidative trace elements in 73 female Japanese university students (age: 19.2 ± 0.7 years). We quantified 8-OHdG and selenium in urine by liquid chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry, respectively. Telomere length and urinary concentrations of other essential trace elements (molybdenum, cobalt, and chromium) that were previously measured in the same study participants, were used in this study. We used multiple linear regression analysis to examine the associations of telomere length with urinary 8-OHdG and essential trace element concentrations (covariates: urinary cotinine concentration, age, BMI, and drinking status). The geometric means (geometric standard deviation) of 8-OHdG and selenium were 3.4 (1.5) and 31 (1.3) µg/g creatinine, respectively. Telomere length was not associated with urinary 8-OHdG concentration, but was negatively associated with urinary selenium concentration. In conclusion, telomere length was not associated with urinary 8-OHdG concentration in the young women in this study. Longitudinal studies should be conducted to clarify the association between telomere shortening rate and oxidative stress level.

BACKGROUND: Adequate maternal thyroid function is important for an uncomplicated pregnancy. Although multiple observational studies have evaluated the association between thyroid dysfunction and hypertensive disorders of pregnancy, the methods and definitions of abnormalities in thyroid function tests were heterogeneous, and the results were conflicting. We aimed to examine the association between abnormalities in thyroid function tests and risk of gestational hypertension and pre-eclampsia. METHODS: In this systematic review and meta-analysis of individual-participant data, we searched MEDLINE (Ovid), Embase, Scopus, and the Cochrane Database of Systematic Reviews from date of inception to Dec 27, 2019, for prospective cohort studies with data on maternal concentrations of thyroid-stimulating hormone (TSH), free thyroxine (FT(4)), thyroid peroxidase (TPO) antibodies, individually or in combination, as well as on gestational hypertension, pre-eclampsia, or both. We issued open invitations to study authors to participate in the Consortium on Thyroid and Pregnancy and to share the individual-participant data. We excluded participants who had pre-existing thyroid disease or multifetal pregnancy, or were taking medications that affect thyroid function. The primary outcomes were documented gestational hypertension and pre-eclampsia. Individual-participant data were analysed using logistic mixed-effects regression models adjusting for maternal age, BMI, smoking, parity, ethnicity, and gestational age at blood sampling. The study protocol was registered with PROSPERO, CRD42019128585. FINDINGS: We identified 1539 published studies, of which 33 cohorts met the inclusion criteria and 19 cohorts were included after the authors agreed to participate. Our study population comprised 46 528 pregnant women, of whom 39 826 (85·6%) women had sufficient data (TSH and FT(4) concentrations and TPO antibody status) to be classified according to their thyroid function status. Of these women, 1275 (3·2%) had subclinical hypothyroidism, 933 (2·3%) had isolated hypothyroxinaemia, 619 (1·6%) had subclinical hyperthyroidism, and 337 (0·8%) had overt hyperthyroidism. Compared with euthyroidism, subclinical hypothyroidism was associated with a higher risk of pre-eclampsia (2·1% vs 3·6%; OR 1·53 [95% CI 1·09-2·15]). Subclinical hyperthyroidism, isolated hypothyroxinaemia, or TPO antibody positivity were not associated with gestational hypertension or pre-eclampsia. In continuous analyses, both a higher and a lower TSH concentration were associated with a higher risk of pre-eclampsia (p=0·0001). FT(4) concentrations were not associated with the outcomes measured. INTERPRETATION: Compared with euthyroidism, subclinical hypothyroidism during pregnancy was associated with a higher risk of pre-eclampsia. There was a U-shaped association of TSH with pre-eclampsia. These results quantify the risks of gestational hypertension or pre-eclampsia in women with thyroid function test abnormalities, adding to the total body of evidence on the risk of adverse maternal and fetal outcomes of thyroid dysfunction during pregnancy. These findings have potential implications for defining the optimal treatment target in women treated with levothyroxine during pregnancy, which needs to be assessed in future interventional studies. FUNDING: Arkansas Biosciences Institute and Netherlands Organization for Scientific Research.

National statistics show that seafood consumption in Japan is decreasing since the mid-1990s. The risks and benefits of this decreasing seafood consumption was assessed in this study. Intake of docosahexaenoic acid (DHA) and methylmercury (MeHg) of women of childbearing age were estimated by using seafood consumption data of women of age 20–39 in the period 2011–2019 and seafood DHA and MeHg content data to find significantly (p < 0.05) decreasing intake of DHA (2.8 mg/day per year) and MeHg (0.19 μg Hg/day per year) in this period. The effect of the decreasing maternal DHA and MeHg intake on infant IQ was estimated by using the equation developed by the FAO/WHO. Net IQ change (the difference in IQ gain by DHA and IQ loss by MeHg) was constant or even increasing, depending on the assumption, in this period while seafood consumption was significantly decreasing. This was due to the decreasing adverse effect of MeHg, along with saturated DHA-derived benefits on infant IQ, even at the decreased seafood consumption of Japanese women of childbearing age. It was indicated that the recent decreasing trend in seafood consumption in Japan did not have an unfavorable effect on infant IQ.

Daily intakes of total (TAs) and inorganic arsenic (iAs), lead (Pb) and aluminum (Al) of the Japanese were estimated by the analysis of duplicated diet samples. The samples were collected for 3 consecutive days from 319 subjects (total number: 949) living in Japan during 2006–2010 by the Ministry of the Environment of Japan. TAs, Pb and Al concentrations in duplicated diet samples, determined by ICP mass spectrometry (ICP-MS) preceded by a microwave acid digestion, and iAs was by liquid chromatography-ICP-MS preceded by an acidic extraction, were used for this study. Median 3-days average intake was calculated to be 2.31, 0.260, 0.0928, and 41.1 μg/kg/day, for TAs, iAs, Pb and Al, respectively (138, 15.3, 5.40, and 2363 μg/person/day). The daily intake levels were found to vary according to subjects’ gender (TAs, Pb, and Al), but this was explained by variation in the amount of daily food consumption. Daily TAs intake was found to vary with age grade, districts where community is located and types (urban/farming/fishing) of community, probably reflecting fish/seaweed consumption.

Cadmium is a toxic metal found ubiquitously throughout the world. Our study evaluated whether cadmium exposure was associated with telomere length in 73 female university students. Determination of telomere length was performed by quantitative polymerase chain reaction using DNA in blood. Urinary cadmium concentration was measured by inductively coupled plasma mass spectrometry. The students' physiological attributes and lifestyle were surveyed by means of a self-administered questionnaire. The geometric mean of urinary cadmium concentration was 0.312 μg/g creatinine, which was lower than the levels previously reported for Japan. Urinary cadmium concentration was not significantly associated with telomere length, though the exposure level of the present subjects was similar to that of previous study subjects which found significantly negative associations. It is possible that other factors affected telomere length in this study population.

Background Arsenic hydrocarbons, major arsenolipids occurring naturally in marine fish, have substantial cytotoxicity leading to human health-related studies of their distribution and abundance in foods. These studies have all investigated fresh foods; because most fish are cooked before being consumed, it is both food- and health relevant to determine the arsenolipids present in cooked fish. Methods We used HPLC/mass spectrometry to investigate the arsenolipids present in salmon (Salmo salar) before and after cooking by either baking or steaming. Results In raw salmon (total As 2.74 mg kg-1 dry mass, of which 6% was lipid-soluble), major arsenolipids were three arsenic hydrocarbons (oxo-AsHC 332, oxo-AsHC 360, and oxo-AsHC 404, ca 55% of total arsenolipids) and a band of unidentified less-polar arsenolipids (ca 40%), trace amounts of another four arsenic hydrocarbons and two thioxo analogs were also detected. During the cooking process, 28% of the oxo-AsHCs were converted to their thioxo analogs. Conclusion Our study shows that arsenic hydrocarbons naturally present in fresh fish are partly converted to their thioxo analogs during cooking by either baking or steaming. The greater lipophilicity of the thioxo analogs could alter the mode of toxicity of arsenic hydrocarbons, and hence future food regulations for arsenic should consider the influence of cooking on the precise type of arsenolipid in fish.

Dietary intake and urinary excretion of monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine (AsB) were measured in 150 adult Japanese subjects. Duplicate diet (DD) samples and first void of urine on the next morning of DD sampling day were collected and analysed for arsenic species with liquid chromatography-ICP mass spectrometry. Median (min-max) intakes of MMA, DMA and AsB were

Telomere length can be a biomarker of cumulative oxidative stress and inflammation indicating biological aging. Previous studies examined association of nutrient intake with telomere length targeting middle-aged and elderly individuals. This study examined whether dietary macro- and micronutrient intake was associated with telomere length in young females.Seventy-four Japanese young females (median (interquartile range) age was 19 (19 - 20) years) participated. We estimated their intake of nutrients (energy, protein, fat, carbohydrate, essential elements, vitamins, fatty acids, and dietary fibre) using a semi-quantitative food frequency questionnaire and measured telomere length (T/S ratio, the ratio of telomere repeat copy number (T) to single-copy gene number (S)) of DNA extracted from blood by qPCR. The association between telomere length and tertiles of nutrient intake were analysed.The median (interquartile range) of telomere length was 0.70 (0.52 - 0.98). Vitamin A intake was positively associated with telomere length (tertile 1 vs. 2, coefficient [95% confidence interval] = 0.42 [0.12, 0.71]; tertile 1 vs. 3, coefficient [95% confidence interval] = 0.33 [0.04, 0.62]) after adjusting for covariates (age, BMI, passive smoking, and drinking).Our findings suggest that variation in vitamin A intake might influence telomere attrition in healthy individuals.

Current power systems on remote islands use diesel generators (DG) that have high operational and maintenance costs, and emit excessive amounts of carbon dioxide. In this respect, power systems based on renewable energy are currently gaining research attention, with the aim of improving the economic performance and reducing greenhouse gas emissions. However, as the output of renewable energy fluctuates and varies depending on weather conditions, a battery energy storage system (BESS) and DG are required to stabilize the renewable energy output. Then the capacity balances of renewable energy, BESS and DG and these operation methods are main issues. In this paper, several output control methods were proposed for DG and the appropriate generators capacity were evaluated. The effectiveness of the methods was then verified by conducting economic and environmental evaluations. This study conducted a numerical simulation using real data, measured in a power system on an existing island in Japan.

An interlaboratory study on the National Institute for Environmental Studies (NIES) certified reference material (CRM) No. 28 Urban Aerosols, collected on the filters of a central ventilating system in a building in Beijing city center, was performed to obtain informative values of Hg isotopic composition and total Hg (THg) mass fraction. The THg mass fraction was determined by four organizations using atomic absorption spectrometry; it resulted in the mean value of 1.19 ± 0.12 mg/kg (2SD, n = 24). The Hg isotopic composition of the CRM was measured and intercompared at two different institutions by cold vapor generation system coupled to multicollector inductively coupled plasma mass spectrometry. Subsequently, a conventional dissolution method that uses a mixture of HNO3/HCl/H2O2 in Hotblock® and two different dissolution methods that use a mixture of HNO3/HCl with a microwave and a digestion bomb were applied. The Hg isotopic compositions were δ202Hg = − 1.26 ± 0.17‰, Δ199Hg = − 0.23 ± 0.06‰, Δ200Hg = 0.01 ± 0.07‰, and Δ201Hg = − 0.22 ± 0.09‰ (2SD, n = 18) for the conventional method, which agree well with those obtained using microwave and bomb digestion. Our results indicate that, for the quality control of particulate matter analyses, this CRM is appropriate for use in environmental and geochemical studies.

BACKGROUND: Adequate transplacental passage of maternal thyroid hormone is important for normal fetal growth and development. Maternal overt hypothyroidism and hyperthyroidism are associated with low birth weight but there are still important knowledge gaps regarding the impact of subclinical thyroid function test abnormalities on birth weight, in general or during the late second and third trimester of pregnancy, remains unknown. The aim of this study was to examine associations of maternal thyroid function with birth weight. METHODS: For this individual-participant data meta-analysis we searched Medline (Ovid), Embase.com, Web-of-Science, Cochrane CENTRAL and Google Scholar from inception to March 18(th) 2018, and published open invitations to join the Consortium on Thyroid and Pregnancy, to identify prospective cohort studies with data on maternal thyroid function during pregnancy and birth weight. We excluded participants with multiple pregnancies, in vitro fertilization, pre-existing thyroid disease or thyroid medication usage, miscarriages and stillbirth. Main outcomes were small for gestational age (SGA), large for gestational age (LGA) (defined by the lowest or highest 10(th) population-specific percentile of birth weight standardized to gestational age and sex, respectively) and birth weight. We analysed individual participant data using mixed-effects regression models adjusting for maternal age, body mass index, ethnicity, smoking, parity, gestational age at blood sampling, fetal sex and gestational age at birth (the latter two only in case of birth weight continuously). The study protocol was pre-registered at the International Prospective Register of Systematic Reviews (PROSPERO), number CRD42016043496. RESULTS: From 2,526 published reports, 36 cohorts met the inclusion criteria and were invited to participate of which 15 agreed and after addition of 5 unpublished datasets, a total of 20 cohorts were included. After exclusions, the study population comprised 48,145 mother-child pairs of whom 1,275 (3·1%) had subclinical hypothyroidism (increased TSH with normal FT4) and 929 (2·2%) had isolated hypothyroxinaemia (decreased FT4 with normal TSH). Maternal subclinical hypothyroidism was associated with a higher risk of SGA compared to euthyroidism (11·8% vs. 10·0% respectively, adjusted risk difference 2·4% [95% CI, 0·4 to 4·8]; odds ratio (OR) 1·24 [95% CI 1·04 to 1.48], P=0·015) and lower mean birth weight (adjusted risk difference −38g [95% CI −61 to −15], P=0·001) with a higher effect estimate for measurement in the 3(rd) trimester compared with the 1(st) or 2(nd) trimester. Isolated hypothyroxinaemia was associated with a lower risk of SGA compared to euthyroidism (7·3% vs. 10·0%, adjusted risk difference −2·9 [95% CI, −4·5 to −0·9]; OR, 0·70 [95% CI 0·55 to 0·91], P=0·007) and higher mean birth weight (difference, 45g [95% CI 18 to 73], P=0·001). Each 1-SD higher maternal TSH concentration was associated with lower birth weight (−6g [−10 to −2], per SD, P=0·003), with higher effect estimates in TPOAb-positive than TPO-negative women (P for interaction=0·10). Each 1-SD higher FT4 concentration was associated with lower birth weight (−21g [95% CI −25 to −17] per SD, P

A certified reference material. NIMD-01, was developed for the analysis of mercury speciation in human hair. We collected the hair of Vietnamese males from a barbershop in Hanoi in 2016 and prepared 1200 bottles containing 3 g of sieved and blended hair powder. The certified value was given on a dry-mass basis, with the moisture content obtained by drying at 85°C for 4 h. Certified values with the expanded uncertainties (coverage factor, k = 2) were as follows: methylmercury, 0.634 ±0.071 mg kg -1 as mercury; total mercury. 0.794 ± 0.050 mg kg -1; copper, 12.8 ± 1.4 mgkg -1; /inc. 234 ± 29 mg kg -1; selenium, 1.52 ± 0.29 mg kg -1. An indicative arsenic concentration of 0.17 ± 0.03 mg kg 1 was measured. Extended uncertainties were estimated by sample homogeneity, long-and short-term stabilities, and a characterization from measurements made by collaborating laboratories.

Quantitative relationship between intake of inorganic arsenic (iAs) and urinary excretion of iAs and its metabolite, methylarsonic acid (MMA), was investigated for 150 adult Japanese subjects. Duplicate diet was used for the determination of intake and first void of urine on the next day of duplicate diet sampling was used for urinary iAs + MMA determination. Speciation analysis of arsenic in diet and urine was carried out with liquid chromatography-inductively coupled plasma mass spectrometry. Geometric mean iAs intake of the subjects was 0.349 μg/kg/day and that of urinary iAs + MMA concentration was 5.20 ng As/mL (specific gravity (SG) corrected) or 4.05 ng As/mg creatinine (Cre). There was a significant positive correlation between iAs intake and urinary iAs + MMA concentration: the correlation coefficient between intake and Cre-corrected urinary concentration (r = 0.544) was greater than that between intake and SG-corrected concentration (r = 0.458). The regression equation of intake-excretion was: log 10 [ d a i l y i n t a k e ] = 0.451 × log 10 [ c r e a t i n i n e c o r r e c t e d u r i n a r y i A s + M M A ] + 0.814 . This equation has a practical value for converting urinary As levels, measured as a biomarker of exposure in epidemiologic study, to dietary intake levels in the future risk assessment.

In this paper, we propose a comprehensive scheme to determine a suitable method and timing for upgrading the voltage control method. Voltage control methods are expected to be upgraded in accordance with the photovoltaic (PV) penetration in distribution systems. The suitable method and timing detailed in this paper are based on the limit of the PV penetration rate, which is constrained by the regulated voltage deviation. The upgrade process involves moving the on-load tap changer (OLTC) control method from the conventional scalar line drop compensator (LDC) method to the vector LDC method or centralized control method. Then, a static var compensator (SVC) or step voltage regulator (SVR) is installed. The locations of the SVR and SVC are determined to maximize the PV penetration rate. The suitable method and timing are demonstrated using a general distribution system. In addition to the numerical simulations, experiments are performed using an active network system with energy resources. The experimental results are consistent with the numerical simulation results, thus validating the proposed scheme. The maximum PV penetration rate obtained using the OLTC control method is 55%. Whereas, the installation of the SVR and SVC increased the rate to 95% and 100%, respectively.

Arsenolipid concentrations were measured in 17 food composites prepared from 152 food items purchased in Shizuoka city, Japan, to (1) determine the food contributing to daily intake of arsenolipids, and (2) estimate the daily intake of arsenolipids. Analysis of arsenolipids was performed by high performance liquid chromatography-inductively coupled plasma mass spectrometry/electrospray ionization tandem mass spectrometry (HPLC-ICP-MS/ESI-MS-MS). Arsenic containing hydrocarbons (AsHCs), arsenic containing fatty acids (AsFAs), and arsenosugar phospholipids (AsSugPLs) were detected only in “algae” and “fish and shellfish” of the 17 food composites in a concentration range of 4.4–233 ng As/g fresh weight (fw). Two cytotoxic arsenolipids, AsHC332 and AsHC360, were detected in “algae” and “fish and shellfish” in the concentrations range of 33–40 ng As/g fw. The estimated average daily intake of AsHC332 and AsHC360 was ca 3000 and 360 ng As/person/day, or 50 and 6.0 ng As/kg bw/day, respectively. The present study indicated that arsenolipids from “algae” and “fish and shellfish” consumption contributed to the daily intake of toxic AsHCs, though the margin of exposure for the AsHC332 and AsHC360 does not appear to pose a health risk for the general Japanese population.

With growing attention to sustainability and recognition of the impact of global warming problems, energy supply and consumption have become critically important. This paper presents the construction of a modeling platform accommodating cooperative energy management systems (EMSs), which virtually produces the model of a smart city with a distribution network (DN) by using a wide range of data obtained from the real world. The platform involves models of various EMSs, governing the operation of a power system or controlling consumer-installed devices, and simulating the power flow, electrical losses, and voltage in the DN. In addition, indices measuring the sustainability of the model city, such as CO2 emission, are estimated from scenarios, for example, photovoltaic system installation, electric vehicle penetration, etc. The results can be visually displayed and the platform is highly versatile and applicable to various types of issues associated with smart cities. Two case studies are presented in detail.

We evaluated the representativeness of concentrations of parabens in a spot urine sample for the assessment of long-term exposure levels. Urine sample was taken monthly from 10 male Japanese subjects (35.9 ± 6.8 years) and 12 female Japanese university students (21.1 ± 0.4 years) for 5 months and measured for methyl (MP), ethyl (EP), propyl (PP) and butyl (BP) parabens by liquid chromatography–tandem mass spectrometry. Median (min–max) specific-gravity-adjusted urinary concentrations of the male group (n = 10) were 39.7 (2.99–268), 1.69 (< 0.045–75.2), 0.569 (< 0.11–123) and 0.0264 (< 0.020–24.4) ng mL−1 for MP, EP, PP and BP, respectively. Those of the female group (n = 12) were 283 (5.49–1687), 9.30 (0.290–487), 22.9 (< 0.11–307) and 3.76 (< 0.020–135) ng mL−1, respectively, which were significantly higher than those of the male group. Intra-class correlation coefficients (ICCs) were calculated for the four parabens to find 0.56, 0.58, 0.39 and 0.28 for MP, EP, PP and BP, respectively, in the ma...

The aim of this study is to demonstrate the effectiveness of debriefing which applies experiences of a history game to contemporary issues, through an evaluation of its practice. Recently, the game has been expected to engage students in a problem-solving process as citizens in social studies lessons. But there are only a few studies of simulation & gaming about history learning, because the method is not clear for students to apply the outcomes of history learning to solutions of contemporary issues. Therefore, a lot of students cannot have the reasons why they need to learn history in school. To solve the above problems, this study designs the debriefing referring to the theory of Kriz, W.C. (2010) and verifies the effectiveness by an evaluation of an experiment. This study organizes the following process in lessons; “Historical Subject” (in the game) → “Transfer Subject” (in the debriefing) → “Contemporary Subject” (in the debriefing). In Contemporary Subject, students think about a contemporary issue by the experiences of the game. Transfer Subject is an exercise to make it easier for students to connect a contemporary issue with a history game. The results of the lessons indicate the following 2 points; 1) the students became able to establish their own opinions about Japanese politics by applying experiences of a history game to contemporary issues. 2) the students became to understand the importance of history learning.

Speciation and isotopic analyses of mercury (Hg) detected at high concentration (11–107 mg total Hg/kg) in the hair samples of Pakistani subjects were carried out to analyze whether the source of Hg was the skin cream or the soap they used. Liquid chromatography-ICP mass spectrometric speciation analysis revealed that the Hg in the hair was primarily inorganic. This result supported our assumption that skin care products were the source of the high concentration of Hg in hair, which was based on the statistical association found in our previous study because it is known that inorganic Hg compounds are added to some skin care products sold in some countries. Stable isotope ratios of the Hg in the hair samples of 6 subjects and 3 skin cream samples, which were reported to be used by the subjects, were measured by multi-collector ICP mass spectrometry after acid digestion. A comparison of the isotopic compositions of Hg in hair and skin cream in two subjects revealed that the composition in both samples matched in one subject, hence confirming that the products were the source of high Hg concentration in hair. However, the isotopic compositions of Hg in hair and skin cream did not match in the other subject demonstrating the presence of other exposure source(s).

This study presents a method for the isotope analysis of gaseous elemental mercury (GEM, Hg 0 (g) ) using cold vapor multicollector inductively coupled plasma mass spectrometry. Isotopic compositions of Hg in the atmospheric samples collected from urban-industrial (Ichikawa) and coastal (South Boso Peninsula) regions in Chiba, Japan were investigated. Values of mass-dependent fractionation (MDF) of δ 202 Hg range from − 2.36‰ to − 0.11‰ and mass-independent fractionation (MIF) of Δ 199 Hg range between − 0.31‰ and 0.01‰. There was a rough linear correlation between δ 202 Hg values and Hg concentrations of our GEM samples ( r 2 = 0.31, p 199 Hg values were positively correlated with SO 2 concentrations; however, air mass source(s) was not identified using NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory model. We suggest that our sampling site, Ichikawa, was largely impacted by nearby anthropogenic sources (high GEM concentration with low δ 202 Hg value), and a mixing with back ground air (low GEM concentration with high δ 202 Hg value).

A simplified questionnaire was developed to assess inorganic arsenic (iAs) intake level in a Japanese population. The two page questionnaire included photographs of single serving sizes of rice and cooked hijiki (Hizikia fusiforme: brown algae), and asked subjects about the number of servings of rice and cooked hijiki, two predominant dietary sources of iAs in Japan, they consume in a day. Daily intake of iAs was estimated for 72 Japanese subjects using the questionnaire together with data of iAs content in rice and hijiki seaweed, and the estimated intakes were compared with actual iAs intakes of the subjects as measured for a duplicate diet using liquid chromatography&ndash, inductively coupled plasma mass spectrometry. A highly significant correlation was found between the estimated and measured intakes (r = 0.65, p &lt, 0.001), however, the slope of regression indicated a systematic error in the intake estimation. Possible sources of error are discussed herein. It was concluded that this approach is promising if minor improvements are made to the questionnaire.

Preterm birth complicates 5% to 15% of births worldwide, and although it is the most important direct cause of morbidity and mortality in children younger than 5 years, no known risk factors can be identified in the majority of cases. However, overt hypothyroidism and hyperthyroidism during pregnancy are well-known risk factors for preterm birth, and as such, the purpose of this study was to assess whether thyroid function test abnormalities and thyroid peroxidase (TPO) antibody positivity were associated with preterm birth. The study conducted a systematic review on the association of thyroid function or autoimmunity with preterm birth published from database inception to March 18, 2018, without language restrictions, using the Ovid MEDLINE, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar databases. Possible studies for inclusion were independently assessed for suitability by 2 of the authors, and study quality and risk of bias were assessed using the Newcastle-Ottawa Scale. Then, authors were contacted to ascertain interest in participating in the individual patient meta-analysis. The primary outcome was preterm birth defined as a gestational age at birth of less than 37 weeks, as assessed using either ultrasound measurements or time after the last menstrual period. Secondary outcomes were very preterm birth (

Higher concentrations of oxidative stress biomarkers are found in women with polycystic ovary syndrome (PCOS) and endometriosis, conditions linked to irregular menstrual cycles and menstrual pain. The aim of the present study was to test whether women with higher oxidative stress are more likely to show irregular menstrual cycles and severe menstrual pain compared with women with lower oxidative stress. A cross-sectional study was conducted targeting female university students with a mean (SD) age of 20.5 (1.8) years (n = 188). Participants completed a questionnaire on reproductive characteristics and anthropometry and kept a menstrual cycle diary for 5 consecutive months. Urinary 8-hydroxy-2&prime, deoxyguanosine (8-OHdG), cotinine, and creatinine concentrations were measured once during the study period. The mean (SD) value of the urinary 8-OHdG concentration was 4.7 (2.0) &mu, g/g of creatinine. A total of 1021 menstrual cycles were recorded. The participants were categorized as either having regular (68%) or irregular (18%) cycles or oligomenorrhea (13%) or polymenorrhea (1%). The urinary 8-OHdG concentration did not significantly differ across menstrual cycle regularity or pain categories. Even after adjusting for age, body mass index (BMI), and urinary cotinine concentrations, having irregular cycles or more severe menstrual pain was not associated with urinary 8-OHdG concentration.

This paper proposes a method to determine the combined energy (kWh) and power (kW) capacity of a battery energy storage system and power conditioning system capacity (kVA) based on load leveling and voltage control performances. Through power flow calculations, a relationship between the capacity combination and the control performance is identified and evaluated. A tradeoff relationship between the capacity combination and control performance is confirmed, and the proper capacity combination for operation is determined based on the evaluated relationship. In addition, the control performance of the capacity combination is evaluated through the power flow calculation, confirming that the proposed method is effective for determining the optimized capacity combination.

Many photovoltaic (PV) systems have been installed in distribution systems. This installation complicates the maintenance of all voltages within the appropriate range in all low-voltage distribution systems (LVDSs) because the trends in voltage fluctuation differ in each LVDS. The installation of a low-voltage regulator (LVR) that can accordingly control the voltage in each LVDS has been studied as a solution to this problem. Voltage control in a medium-voltage distribution system must be considered to study the deployment of LVRs. In this study, we installed LVRs in the LVDSs in which the existing voltage-control scheme cannot prevent voltage deviation and performed a numerical simulation by using a distribution system model with PV to evaluate the deployment of the LVRs.

Compensation of a voltage within the appropriate range becomes difficult when a large number of photovoltaic (PV) systems are installed. As a solution to this problem, the installation of a low-voltage regulator (LVR) has been studied. In this paper, we propose a method for instantly and accurately determining the line drop compensator (LDC) method parameters as a part of a voltage management scheme, which consists of prediction, operation, and control. In the proposed method, the solution candidates of the proper LDC parameters are narrowed by using a random forest that learns the relationship between the power-series data and the properness of the LDC parameters, thereby reducing the computational cost. We performed numerical simulations to verify the validity of the proposed method. From the results, the LDC parameters can be rapidly and accurately determined. Additionally, the desirable voltage control performance is verified.

Food categories that significantly contribute to daily intake of total arsenic (TAs), inorganic arsenic (iAs), lead (Pb) and aluminium (Al) were statistically sought for the 949 duplicate diet samples collected from 319 households in Japan. Daily intakes of TAs, iAs, Pb and Al were calculated based on measured element concentration in duplicate diet samples and weight of the samples. Amounts of consumption of 12 food categories of each duplicate diet sample were self-reported (beverage), interviewed (fat and oil, spices, and sugar) and actually weighted (other 9 categories) at the time of diet sampling. Multiple regression analyses were conducted by using daily element intake as dependent variable and amounts of daily consumption of the 12 food categories as independent variables. The most significant predictors were amount of daily consumption of ‘Fish & Shellfish’ for daily TAs intake and ‘Rice & Rice products’ for iAs intake. Other food categories contributed to daily intakes of the four elements with smaller coefficient. Some of the significant predictors identified in this study were consistent with the findings of the previous market basket surveys while others were not. The 12 food category consumption data moderately explained daily intake of TAs (Coefficient of determination adjusted for degree of freedom (adjusted R2) = 0.447) and iAs (0.307) while they only poorly explained daily intakes of Pb (0.229) and Al (0.117). The present results suggest that a Total Diet Study based on food consumption survey data and element contents of food from data base/literature will result in large errors in the estimation of daily element intake.

OBJECTIVES To acquire fundamental knowledge on menstrual cycle and its intraindividual variation in healthy Japanese female students and their association with biological attributes, lifestyle and food habit. METHODS We asked female students of a nursing school to keep a diary of their menstruation over 5 consecutive months and to fill a questionnaire on their biological attributes, lifestyle and consumption frequency of some food items during the period from November 2012 to January 2014. RESULTS The mean±standard deviation (SD) of cycle lengths of 180 women (20.4±0.9 yrs) was 34.2±10.5 days. Of these 180 women, 141 had a cycle length within the normal range (25-38 days) while 10 had a shorter cycle and 20 had a longer cycle. The intraindividual variations of the cycle, defined as "range" (difference between the longest and shortest cycles of an individual) and "SD" (SD of mean of multiple lengths within an individual), were 11.4±10.3 and 7.9±11.8 days, respectively. Of 177 women, 73 and 109 had normal range and SD (≤6 days), respectively. The mean age of women with long cycles was older than that of women with short cycle (Kruscal-Wallis test, p

This paper discusses the novel voltage control method in the distribution system using the electronic devices. In order to stabilize the power flow of the system, voltage in the system is traditionally controlled by devices such as load ratio control transformers (LRTs) installed in the distribution substation and step voltage regulators (SVRs) installed in the distribution line according to their fixed control parameters. In this paper, the authors verify the optimal interval of updating the control parameters of advanced SVRs using the determining method of control parameters.