The effect of molecular structure of polypropylene on stretchability for biaxially oriented film

Biaxially oriented polypropylene films are widely used for food packaging and industrial films. Recently, machine speed has been increasing in order to obtain higher production rate, and film thickness has become thinner to reduce the environmental load. The customers\u27 requirements for better production ability and thinner films have been becoming more demanding, but their demands are not always met because of lack of film stretchability in the final product. To meet the demands, research on stretchability has been conducted with the goal of finding the optimum polypropylene molecular structure for developing a new product by analyzing stretching force-strain data using a table tenter, which was thought to be the parameter of stretchability. It was found that low crystallinity and wide molecular weight distribution were effective in improving the stretchability from the table tenter test. By running the test with a sequential and biaxially oriented stretching machine, it was verified that samples produced by the above designed polymer indicated good thickness uniformity, which was considered to be the barometer of stretchability. Furthermore, it was concluded that analyzing the stretching force-strain data obtained from a table tenter is a good method to predict machine speed and film thickness. © 2012 Society of Plastics Engineers

Motion and Speed of the Frail Elderly During Evacuation Process

健常者よりも運動能力が劣る要介護者が迅速に避難できるように準備することは，要介護者の命を救うだけでなく，介護スタッフの命を守ることにも繋がる。しかし，現状では要介護者の避難行動速度すら十分に調査されておらず，要介護者の避難を検討する上での情報が不足している。そこで，本研究では要介護者の避難訓練の様子を撮影し，歩行速度をはじめとする避難行動速度を詳細に調査した。その結果，すべての行動が健常者よりも遅いが，階段の上りと車からの降車が特に時間を要することがわかった。さらに，得られた行動速度を入力にして，エージェントモデルで避難訓練をシミュレートしたところ，シミュレーションの方が1割程度早く避難が完了する結果となった。しかしながら，この避難完了時間の違いは，介護スタッフの行動の中の「シミュレーションに考慮されていない行動」に掛かる時間を考慮することでほぼ解消した。While agent simulation has been used to investigate evacuation scenarios, evacuation speed of frail elderly has not been fully studied yet. Therefore, in order to obtain the evacuation speed of the frail elderly we recorded videos of evacuation drills held in a group home with care. We analyzed evacuation steps in detail through the videos and acquired the evacuation speed of the frail elderly. We also simulated the evacuation drills with an agent model using the observed data. In the simulation result, the evacuation completion time was about 10% faster than the measured time of the evacuation drills. The difference in evacuation completion time can be explained considering the time taken for “unplanned behavior” of caregivers such as stopping to think about the next action

Crater formation mechanism on the surface of a biaxially oriented polypropylene film

Biaxially oriented polypropylene (BOPP) films are used in a variety of areas around the world. They are especially well suited for food packaging and industrial usages because of their high productivity. Many studies on the stretchability with regard to crystal structure changes have been reported by various researchers because the machine speed has been increasing and the demand to produce thinner films has been becoming more important. Furthermore, a number of studies on the surface structure of BOPP films with craterlike roughnesses have been reported since the 1980s. Although a craterlike surface roughness was formed under specific film process conditions, the formation mechanism and the controlling method of the craterlike film surface are yet to be clarified. In this report, we demonstrated a new hypothesis for the craterlike film surface roughness formation mechanism by analyzing the morphology of the surface layer of polypropylene (PP) sheets and by investigating the relationship between the surface structural changes and the changes in the entire structure. As a result, we found that an overcritical crystallization time was needed to form the crater on the surface of the BOPP film, and the crater formation mechanism was closely related not only to the surface structure changes but also to the deformation phenomenon of the spherulite in the PP sheet during stretching. Furthermore, this report shows the controlling factors in the formation of the crater structure from the viewpoint of the production conditions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012 Copyright © 2012 Wiley Periodicals, Inc

Crystallization of polypropylene near the surface in injection-molded plaques: A comparison of morphology and a numerical analysis

Skin morphology formation on injection-molded isotactic polypropylene (PP) was investigated using micro-beam synchrotron wide-angle X-ray diffraction and numerical simulation. The 1-20 Î?m depth range was characterized with an X-ray beam of 0.273 Î?m Ï? 0.389 Î?m in size. From an evaluation of doping nucleating agents (NA) in PP, the NAs did not work at a depth of 1 Î?m. α-specified NA affected crystallization within a 5-Î?m depth. β-specified PP showed α-form crystallinity at the 5-20 Î?m depth. The mesomorphic crystal near the surface showed extremely high orientation. From viscoelastic flow simulation, PP molecules near the surface were oriented in the flow direction by extensional flow in the flow front, but freezing occurred faster than flow-induced crystallization. It was estimated that the delay of crystallization occurred during the transient temperature. The deformation rate did not cause a difference in crystal morphology near the surface, but the cooling rate did. Copyright © 2009 Society of Plastics Engineers

New bleeding model of additives in a polypropylene film under atmospheric pressure

Many additives are commercially used to add more favorable qualities to films. The bleeding process by which the additive in a film comes to the surface is considered. A new bleeding model of additives in a polypropylene film under atmospheric pressure was investigated. Solubility and diffusion are found to be important for explaining this bleeding process. The solubilities and diffusion coefficients of higher fatty acid amides such as erucamide (13-cis-docosenamide) and behenamide (docosanamide) were determined between 40 and 70°C and the difference between the solubilities and the diffusion coefficients was discussed. The experimental results are explained more precisely by assuming two transport processes between the crystalline regions and the amorphous ones. © 2007 Wiley Periodicals, Inc

New bleeding model of additives in a polypropylene film under atmospheric pressure II

金沢大学大学院自然科学研究科出光興産㈱　先進技術研究所　解析技術センター 第二解析技術室Many additives are commercially used to add more favorable qualities to films. The bleeding process by which the additive in a film comes to the surface is considered. A new bleeding model of additives in a polypropylene film under atmospheric pressure was investigated. Solubility and diffusion are found to be important for explaining this bleeding process. It was found that the experimental results were explained more precisely by assuming a twostep transport process between the crystalline regions and the amorphous ones. The solubilities and diffusion coefficients of UV-stabilizers such as 2-(2H-benzotriazol-2-yl)-4(l,l,3,3-tetramethylbutyl)phenol and 2-(2H-benzotriazol-2yl)-4-methylphenol were determined at 4O°C. The difference between the saturation solubilities and the diffusion coefficients of UV-stabilizers was discussed by comparing with the results of molecular dynamics (MD) simulation. © 2007 Wiley Periodicals, Inc

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target