Surface Morphology and Properties of Bombyx mori Silk Fibroin Fiber Treated with I-2-KI Aqueous Solution

The surface morphology, thermal and mechanical properties of Bombyx mori silk fibroin (SF) fiber treated with a 1.23 N iodine-potassium iodide (I-2-KI) aqueous solution were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry, thermogravimetric analysis, and tensile measurements to clarify the effects of the iodine treatment. SEM and AFM analyses indicated that the SF fiber surface became rougher by the absorption of polyiodide ions. The mechanical properties of iodinated SF showed an increase in Young's modulus, and strain remained constant although ultimate tensile strength slightly decreased. The thermal stability of SF molecules was greatly enhanced by iodine treatment. Iodinated SF fibers should be an attractive candidate for biomedical applications such as for producing antimicrobial filters, iodine containing wound-healing anion exchange fibers, etc.ArticleTEXTILE RESEARCH JOURNAL. 79(14):1305-1311 (2009)journal articl

Nanocomposite of silk fibroin nanofiber and montmorillonite: Fabrication and morphology

The purpose of our research is creating a new nanocomposite material. Generally silk fibroin (SF) is regarded as a promising base material for biomedical uses. The incorporation of montmorillonite (MMT) into SF fibers would improve physical properties of the SF fibers. We investigated a new method of combining electospun SF with MMT. Specifically, electrospun silk nanofibers were treated with methanol and dipped in a MMT suspension. We could obtain a nanosheet composite of silk nanofibers and MMT. Their ultrastructures were successfully visualized by high resolution transmission electron microscopy. This compound was comprised of individual silk nanofibers surrounded by thin layers of MMT, each with a thickness of about 1.2 nm. This structure was confirmed by elemental analysis. We also performed IR, NMR and X-ray diffraction analyses in conjunction with morphological data. Conclusively we obtained a new composite of silk nanofiber and MMT, which has never been reported. Using this unique nanocomposite biological tests of its application for a scaffold for tissue engineering are under way.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 57:124-128 (2013)journal articl

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

Desempeños del alumnado de Educación Secundaria en la evaluación de una investigación científica en el contexto de la industria láctea

En este estudio se analizan los desempeños de estudiantes de 2.º, 3.º y 4.º de ESO (14, 15 y 16 años) que cursan la asignatura de Física y química, cuando evalúan el diseño de una investigación sobre un problema de precipitación identificado en la industria láctea. Los desempeños se examinan por separado para cada dimensión del diseño: identificación de la cuestión objeto de investigación, formulación de hipótesis, planificación de la investigación y selección del criterio de finalización. Para el análisis de resultados, se recogen sus propuestas, en las que han de estar desarrolladas las siguientes tareas: seleccionar la mejor opción, justificar su elección y modificar la opción alternativa para convertirla en correcta. Los resultados menos adecuados corresponden a las dos últimas dimensiones citadas.In this paper we analyse the performance of 8th, 9th and 10th grade students (14, 15 and 16 years old respectively), attending Physics and Chemistry lessons, when assessing the design of scientific research on a precipitation problem identified in the dairy industry. Students' performances are examined separately for each dimension involved in the design: identifying the issue to be studied, posing the hypotheses, planning the research and selecting the ending criterion. For the analysis, we collect participants' individual proposals, which have to include the following tasks: selecting the best option, justifying their choice and modifying the alternative option so that it will be correct. The less adequate results correspond to the last two dimensions

日本人男性海外勤務者の精神的健康度と職業関連要因との関係

目的：海外勤務者の精神的健康度と職業関連要因の関係と日本国内勤務者の精神的健康度の違いを明らかにすることである。方法：同一の金属製品製造業に勤務する男性海外勤務者450名と男性日本国内勤務者683名を対象に自記式質問紙調査を行った。精神的健康度は日本版気分プロフィール検査を用いて評価した。 結果：日本国内と海外勤務者の精神的健康度の比較では、34－39歳において海外勤務者が日本国内より低く、40代と50代では海外勤務者が日本国内より高かった。 　ロジスティック重回帰分析の結果、精神的健康度の不良に関連していたものは、ヨーロッパに対して東アジア（e.g. オッズ比 : 7.548, 95%信頼区間［以下CI］: 2.912－22.293［抑うつ－落込み〔以下D〕］）、東南・南アジア（e.g. オッズ比 : 4.675, 95% CI : 1.679－14.433［D］）、北米（e.g. オッズ比 : 3.997, 95% CI : 1.495－11.895［D］）。管理職に対してエンジニア（e.g. OR : 2.328, 95% CI : 1.168－4.679［緊張－不安〔以下T－A〕］）と生産管理（OR: 5.268, 95% CI : 1.520－18.013［T－A］）。労働時間10－11時間未満に対して12－13時間未満（e.g. OR : 2.063, 95% CI : 1.007－4.283［D］）、13時間以上（e.g. OR : 2.651, 95% CI :1.227－5.814［D］）。休日日数 8 日以上に対して 5 日未満（e.g. OR : 2.285, 95% CI : 1.276－4.129［疲労〔以下F〕］）、5－7日以下（e.g. OR : 2.219, 95% CI: 1.246－4.000［F］）であった。結論：海外勤務者の精神保健対策は、地域別ではアジア圏特に東アジア、職種ではエンジニアや生産管理を中心に取り組んでいく必要がある。また実労働時間が12時間を超える者や休日日数が7日以下の者には、就労時間の制限や休日日数を 8 日以上確保することも対策として考えられた。Objectives : The aim of this study was to clarify the relationship between the mental-health status of overseas employees and work-related factors, and also to determine the difference between the mental-health status of these employees and their counterparts in Japan. Method : Four hundred and fifty male overseas employees and 683 male employees in Japan were surveyed using a self-assessment questionnaire, namely the Japanese version of the Profile of Mood States, which is used to assess mental-health status. Result: The mental-health status of overseas employees in the age range 34－39 years was worse, and that for those in their forties and fifties better, than those o employees in Japan. A multiple logistic regression analysis showed that employees in East Asia Southeast & South Asia and North America were positively associated with poor ental-health status compared with employees in Europe (e.g. odd ratio [OR] : 7.548, 95% confidence interval [CI] : 2.912－22.293, OR : 4.675, 95% CI : 1.679－14.433 and OR: 3.997, 95% CI : 1.495－11.895 in depression/dejection, respectively). Engineers and production controllers were positively associated with poor mental-health status compared with those in managerial posts (e.g. OR : 2.328, 95% CI : 1.168－4.679 and OR : 5.268, 95% CI : 1.520－18.013 in tension/anxiety, respectively). As regards average daily working hours, those employees working for between 12 and less than 13 hours and 13 hours or more were positively associated with poor mentalhealth status compared with those working for between 10 and less than 11 hours (e.g. OR : 2.063, 95% CI : 1.007－4.283 and OR : 2.651, 95% CI : 1.227－5.814 in depression/dejection, respectively). In terms of number of days’ holiday in the last month, those employees who had taken less than five days and between five days and seven days were positively associated with poor mental-health status comparison with those who had taken eight days or more (e.g. OR : 2.285, 95% CI : 1.276－4.129 and OR : 2.219, 95% CI : 1.246－4.000 in fatigue, respectively). Conclusion : Mental-health protection measures in overseas bases need to focus on Asia, especially East Asia and employees who work as engineers or production controllers. Furthermore, average daily working hours should be shortened as much as possible and employees should take at least eight days’ holiday per month

Self-reported speed of eating and 7-year risk of type 2 diabetes mellitus in middle-aged Japanese men

Objective: This cohort study investigated the association between eating speed and the incidence of type 2 diabetes in middle-aged Japanese men. Materials/Methods: Participants were 2,050 male employees of a metal products factory in Japan. We measured self-reported categorical eating speed. The incidence of diabetes was determined in annual medical examinations over a 7-year period. The association between eating speed and the incidence of diabetes adjusted for multiple variables (age, family history of diabetes, smoking, alcohol drinking, habitual exercise, and presence of hypertension and hyperlipidemia) was evaluated using Cox proportional hazards models. Results: The prevalence of obesity (BMI ≥ 25 kg/m 2) across the categories of eating speed (slow, medium, and fast) was 14.6, 23.3, and 34.8%, respectively, and a faster eating speed was associated with a higher prevalence of obesity. During the study, 177 participants developed diabetes. Crude incidence rates (/1,000 person-years) across the three categories of eating speed were 9.9, 15.6, and 17.3, respectively. Multivariate-adjusted hazard ratios (95% CI) across the categories were 1.00 (reference), 1.68 (0.93-3.02), and 1.97 (1.10-3.55), respectively, and eating speed was associated with the risk of diabetes (p for trend = 0.030). After further adjustment for BMI, a significant association was not observed. Conclusions: Eating speed was associated with the incidence of diabetes. Since these associations were not significant after adjusting for BMI, eating speed may act via its effect on body weight. Eating speed is a controllable risk factor, and eating slowly could be an acceptable lifestyle intervention for the prevention of diabetes mellitus. © 2012 Elsevier Inc. All rights reserved

Family history of diabetes, lifestyle factors, and the 7-year incident risk of type 2 diabetes mellitus in middle-aged Japanese men and women

Aims/Introduction: This cohort study of middle-aged Japanese participants investigated the relationship between family history of diabetes, the incident risk of type 2 diabetes and the interaction of these variables with other factors. Materials and Methods: Study participants were 3,517 employees (2,037 men and 1,480 women) of a metal products factory in Japan. Baseline health examinations included questions about medical history, physical examination, anthropometric measurements, questions about lifestyle factors, such as smoking, alcohol consumption and habitual exercise, and a self-administered diet history questionnaire. Family history of diabetes was defined as having at least one-first-degree relative with diabetes. The incidence of diabetes was determined in annual medical examinations over a 7-year period. Hazard ratios (HRs) for type 2 diabetes were estimated by Cox proportional hazards analysis. Results: Of the 3,517 participants, 630 (18%) had a family history of diabetes mellitus. During the study, 228 participants developed diabetes. The age and sex-adjusted HR for type 2 diabetes in participants with a family history of diabetes was 1.82 (95% confidence interval 1.36-2.43) as compared with those without a family history of diabetes. HRs did not change after adjustment for body mass index and lifestyle factors. We found no interactions with body mass index, insulin resistance, pancreatic β-cell function or lifestyle factors. Conclusions: Family history of diabetes was associated with the incident risk of diabetes, and these associations were independent of other risk factors, such as obesity, insulin resistance, and lifestyle factors in Japanese men and women. © 2013 Asian Association for the Study of Diabetes and Wiley Publishing Asia Pty Ltd