Integrated cosmic muon flux in the zenith angle range 0<cosθ<0.370 < \text{cos}\theta < 0.37 for momentum threshold up to 11.6 GeV/c

We have measured the cosmic muon flux in the zenith angle range<cosθ<0.37 with a detector comprising planes of scintillator hodoscope bars and iron blocks inserted between them. The muon ranges for up to 9.5 m-thick iron blocks allow the provision of muon flux data integrated over corresponding threshold momenta up to 11.6 GeV/c. Such a dataset covering the horizontal direction is extremely useful for a technique called muon radiography, where the mass distribution inside a large object is investigated from the cosmic muon distribution measured behind the object

Detection of on-surface objects with an underground radiography detector system using cosmic-ray muons

We have developed a compact muon radiography detector to investigate the status of the nuclear debris in the Fukushima Daiichi Reactors. Our previous observation showed that a large portion of the Unit-1 Reactor fuel had fallen to floor level. The detector must be located underground to further investigate the status of the fallen debris. To investigate the performance of muon radiography in such a situation, we observed 2 m cubic iron blocks located on the surface of the ground through different lengths of ground soil. The iron blocks were imaged and their corresponding iron density was derived successfully

シンリョウジョ シュッサン シタ ジョセイ ノ ニンシン リスクスコアヲ モチイタ リスク ヒョウカ ノ ケントウ

目的 平成16年に開発された妊娠リスクスコア自己評価表(以下,スコア)を用いて診療所で出産した女性の得点を算出し,リスクレベルの傾向とスコアの特徴,分娩帰結との関連を検討する.方法 対象はA診療所で平成20年1月～ 12月に分娩し協力が得られた124名である.診療録よりスコアの評価項目と分娩帰結の情報を収集し,スコアA(初診時評価点)とスコアB(妊娠後半期評価点),合計スコア(スコアAとスコアBの総合得点)を算出した.次に,スコアA,スコアB,合計スコアそれぞれについて早産,分娩時異常出血(1,000ml以上),低出生体重児,吸引分娩,帝王切開分娩の5項目と低リスク群(0-1点)・中リスク群(2-3点)・高リスク群(4点以上)間の関連をみた.結果 平均年齢30.5±3.45歳,初産婦4割,経産婦6割であった.スコア別リスク群別割合は,スコアAで1点が37.9%と最も多く,低リスク群が半数(58.9%)を占めた.スコアBでは0点が80.6%と最も多く,同群が8割以上(83.1%)を占めた.合計スコアをみると中・高リスク群合わせて全体の50.1%を占めた.分娩帰結に異常がなかった事例は全体の78.2%で,うち診療所が単独で扱えない中・高リスク群は37.1%であった.一方早産,分娩時異常出血,低出生体重児,吸引分娩,帝王切開の帰結をとった事例は全体の21.8%あり,うち低リスク群は3.2%(4件)あった.スコアBで加点された事例を概観すると分娩帰結に大きな影響を及ぼす事例であった.χ2独立性の検定の結果,特に,Bスコアで骨盤位,IUGR,低位胎盤,双胎により2点以上の得点が付いた場合と,帝王切開や低出生体重児である傾向に関連があった.結論 1.スコアAは容易に加点されるが分娩帰結に影響を与える項目は少なく,スコアBは容易に加点されないが加点されると分娩帰結に直結する項目が多かった.2.妊産婦らが忠実にスコアの評価基準を守れば,約半数が二次・三次医療施設での健診・分娩が適切であると判断される.3.リスク得点が分娩帰結を反映していない事例が一部存在した.4.妊婦の後半期の評価において2点以上のリスク得点が付く場合には,帝王切開と低出生体重児などの異常帰結を取る傾向があり,スコアBの有用性が示唆された.Aim To use the pregnancy risk score self-assessment form developed in 2004 to examine the relationship between the risk level of women who delivered at a clinic and the birth result.Method The subjects were 124 women who gave birth from January～December 2008 at Clinic A and from whom consent was obtained.Birth results and scored items were collected from medical records to calculate Score A(first medical examination),Score B(latter half of pregnancy),and the Total Score(A and B).Next, with regard to each score,correlations were sought between five items(premature delivery,intrapartum abnormal bleeding(1,000ml or more),low birth weight infant,vacuum extraction and caesarean delivery) and the low(0-1 points),intermediate(2-3 points)and high(4 or more points)risk groups. Results Subjects\u27 mean age was 30.5±3.45 years with 40% primipara and 60% multipara.Inspection showed a correlation tending toward caesarean section(r=0.506)or low birth weight infant(r=0.409),particularly when two or more points were assigned for breech presentation, IUGR,low lying placenta or twin fetus to Score B. Conclusion When two or more points were assigned to the risk score during the latter half of pregnancy, there was a tendency toward caesarean operation,lower birth weight infant or other abnormal results, suggesting the utility of Score B

Imaging the inner structure of a nuclear reactor by cosmic muon radiography

We studied the inner structure of the nuclear reactor of the Japan Atomic Power Company (JAPC) at Tokai, Japan, by muon radiography. Muon detectors were placed outside the reactor building. By detecting cosmic muons penetrating the wall of the reactor building, we could successfully identify objects such as the containment vessel, pressure vessel, and other structures of the reactor. We also observed a concentration of heavy material which can be attributed to the nuclear fuel assemblies stored in the nuclear fuel storage pool

Effectiveness of COVID-19 vaccination in healthcare workers in Shiga Prefecture, Japan

This study, which included serological and cellular immunity tests, evaluated whether coronavirus disease 2019 (COVID-19) vaccination adequately protected healthcare workers (HCWs) from COVID-19. Serological investigations were conducted among 1600 HCWs (mean ± standard deviation, 7.4 ± 1.4 months after the last COVID-19 vaccination). Anti-SARS-CoV-2 antibodies N-Ig, Spike-Ig (Roche), N-IgG, Spike-IgM, and -IgG (Abbott), were evaluated using a questionnaire of health condition. 161 HCWs were analyzed for cellular immunity using T-SPOT® SARS-CoV-2 kit before, and 52 HCWs were followed up until 138.3 ± 15.7 days after their third vaccination. Spike-IgG value was 954.4 ± 2282.6 AU/mL. Forty-nine of the 1600 HCWs (3.06%) had pre-existing SARS-CoV-2 infection. None of the infectious seropositive HCWs required hospitalization. T-SPOT value was 85.0 ± 84.2 SFU/106 cells before the third vaccination, which increased to 219.4 ± 230.4 SFU/106 cells immediately after, but attenuated later (to 111.1 ± 133.6 SFU/106 cells). Poor counts (< 40 SFU/106 cells) were present in 34.8% and 38.5% of HCWs before and after the third vaccination, respectively. Our findings provide insights into humoral and cellular immune responses to repeated COVID-19 vaccinations. COVID-19 vaccination was effective in protecting HCWs from serious illness during the original Wuhan-1, Alpha, Delta and also ongoing Omicron-predominance periods. However, repeated vaccinations using current vaccine versions may not induce sufficient cellular immunity in all HCWs

Serology suggests adequate safety measures to protect healthcare workers from COVID-19 in Shiga Prefecture, Japan.

Healthcare workers (HCWs), especially frontline workers against coronavirus disease 2019 (COVID-19), are considered to be risky because of occupational exposure to infected patients. This study evaluated the correlation between seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies among HCWs and the implementation of personal protective equipment (PPE) & infection prevention and control (IPC). We recruited 1237 HCWs from nine public COVID-19-designated hospitals in Shiga Prefecture, central Japan, between 15-26 February 2021. All participants answered a self-administered questionnaire and provided blood samples to evaluate SARS-CoV-2 antibodies. A total of 22 cases (1·78%) were seropositive among the 1237 study participants. An unavoidable outbreak of SARS-CoV-2 had occurred at the terminal care unit of one hospital, before identifying and securely isolating this cluster of cases. Excluding with this cluster, 0·68% of HCWs were suspected to have had previous SARS-CoV-2 infections. Binomial logistic regression from individual questionnaires and seropositivity predicted a significant correlation with N95 mask implementation under aerosol conditions (p = 8.63e-06, aOR = 2.47) and work duration in a red zone (p = 2.61e-04, aOR = 1.99). The institutional questionnaire suggested that IPC education was correlated with reduced seropositivity at hospitals. Seroprevalence and questionnaire analyses among HCWs indicated that secure implementation of PPE and re-education of IPC are essential to prevent SARS-CoV-2 infection within healthcare facilities. Occupational infections from SARS-CoV-2 in healthcare settings could be prevented by adhering to adequate measures and appropriate use of PPE. With these measures securely implemented, HCWs should not be considered against as significantly risky or dirty by local communities