Extremely Long Chains of Magnetic Particles via Large Plastic Beads Observed in Bimodal Magnetic Elastomers.

The relationship between the magnetorheology of bimodal magnetic elastomers with high concentrations (60 vol %) of plastic beads with diameters of 8 or 200 µm and the meso-structure of the particles was investigated. Dynamic viscoelasticity measurements revealed that the change in storage modulus of the bimodal elastomer with 200 µm beads was 2.8 × 105 Pa at a magnetic field of 370 mT. The change in the storage modulus for monomodal elastomer without beads was 4.9 × 104 Pa. The bimodal elastomer with 8 µm beads hardly responded to the magnetic field. In-situ observation for the particle morphology was performed using synchrotron X-ray CT. For the bimodal elastomer with 200 µm beads, a highly aligned structure of magnetic particles was observed in the gaps between the beads when the magnetic field was applied. On the other hand, for the bimodal elastomer with 8 µm beads, no chain structure of magnetic particles was observed. The orientation angle between the long axis of the aggregation of magnetic particles and the magnetic field direction was determined by an image analysis in three dimensions. The orientation angle varied from 56° to 11° for the bimodal elastomer with 200 µm beads and from 64° to 49° for that with 8 µm beads by applying the magnetic field. The orientation angle of the monomodal elastomer without beads changed from 63° to 21°. It was found that the addition of beads with a diameter of 200 µm linked the chains of magnetic particles, while beads with a diameter of 8 µm prevented the chain formation of the magnetic particles.

In Situ Observation of the Movement of Magnetic Particles in Polyurethane Elastomer Densely Packed Magnetic Particles Using Synchrotron Radiation X-ray Computed Tomography.

In situ observation of the migration and structure formation of magnetic particles in polyurethane elastomers was carried out by X-ray computed tomography using synchrotron radiation. The mean diameter of the magnetic particles was 7.0 µm, and the volume fraction was ϕ= 0.24 at its maximum. The exposure time was 100 ms/frame, and the pixel size was 0.458 µm/pixel. The orientation angle and the volume fraction of the maximum aggregate were analyzed using commercial software for image analysis. The orientation angle for magnetic elastomers with ϕ = 0.24 was approximately 55° at 0 mT and decreased remarkably with the magnetic field. At magnetic fields above 150 mT, the orientation angle gradually decreased with the field and showed a constant value of 38° at 300 mT, suggesting that magnetic particles move and form a chain-like structure although the chains do not align perfectly in the direction of the magnetic field. On the other hand, the volume fraction of the maximum aggregate was constant at magnetic fields below 100 mT, and it significantly increased with the field, indicating that magnetic particles were connected to each other and developed into a macroscopic structure with anisotropy. Dynamic viscoelastic measurements revealed that the storage modulus of the magnetic elastomers cannot be simply scaled by the orientation angle. It was also found that the volume fraction of the maximum aggregate is a good parameter for explaining the huge increase in the storage modulus. The dynamic movement of magnetic particles when a magnetic field of 300 mT was switched on and off was also successfully observed. When the field was switched on, magnetic particles connected instantly and their aggregates were rapidly elongated in the direction of the magnetic field. When the field was switched off, some of the connections between aggregates were broken; however, most of the aggregates did not return to the original position even 5 min after being switched off.

Rare earth element identification and quantification in millimetre-sized Ryugu rock fragments from the Hayabusa2 space mission.

Millimetre-sized primordial rock fragments originating from asteroid Ryugu were investigated using high energy X-ray fluorescence spectroscopy, providing 2D and 3D elemental distribution and quantitative composition information on the microscopic level. Samples were collected in two phases from two sites on asteroid Ryugu and safely returned to Earth by JAXA's asteroid explorer Hayabusa2, during which time the collected material was stored and maintained free from terrestrial influences, including exposure to Earth's atmosphere. Several grains of interest were identified and further characterised to obtain quantitative information on the rare earth element (REE) content within said grains, following a reference-based and computed-tomography-assisted fundamental parameters quantification approach. Several orders of magnitude REE enrichments compared to the mean CI chondrite composition were found within grains that could be identified as apatite phase. Small enrichment of LREE was found for dolomite grains and slight enrichment or depletion for the general matrices within the Ryugu rock fragments A0055 and C0076, respectively. Supplementary Information: The online version contains supplementary material available at 10.1186/s40623-022-01705-3.

Methods for dynamic synchrotron X-ray respiratory imaging in live animals.

Small-animal physiology studies are typically complicated, but the level of complexity is greatly increased when performing live-animal X-ray imaging studies at synchrotron and compact light sources. This group has extensive experience in these types of studies at the SPring-8 and Australian synchrotrons, as well as the Munich Compact Light Source. These experimental settings produce unique challenges. Experiments are always performed in an isolated radiation enclosure not specifically designed for live-animal imaging. This requires equipment adapted to physiological monitoring and test-substance delivery, as well as shuttering to reduce the radiation dose. Experiment designs must also take into account the fixed location, size and orientation of the X-ray beam. This article describes the techniques developed to overcome the challenges involved in respiratory X-ray imaging of live animals at synchrotrons, now enabling increasingly sophisticated imaging protocols.

Interrelationship among the health-related and subjective quality of life, daily life activities, instrumental activities of daily living of community-dwelling elderly females in orthopedic outpatients.

[Purpose] This study aimed to examine the health-related and subjective quality of life of community-dwelling elderly females in orthopedic outpatients, and also examined how such quality of life correlate with their daily life activities and instrumental activities of daily living. [Subjects and Methods] Subjects were 27 community-dwelling elderly females in orthopedic outpatients (mean age: 76.3 ± 7.4 years). Their health-related quality of life and subjective quality of life, life-space assessment, frenchay activities index were researched. [Results] For the relationships between the total subjective quality of life scores and health-related quality of life scores, significant positive correlations were observed for body pain, general health, vitality, social functions and mental health. The correlations were not statistically significant between the subjective quality of life scores and the life-space assessment and frenchay activities index scores. The correlations were statistically significant between some health-related quality of life scores and the life-space assessment and frenchay activities index scores. [Conclusion] The results suggest that supporting community-dwelling elderly females in orthopedic outpatients to improve their sense of physical and mental well-being, and prevent and reduce their depression and physical pain, is required in order to improve their QOL.

Factors affecting the quality of life of homebound elderly hemiparetic stroke patients with cognitive impairment.

[Purpose] This study examined the quality of life of homebound elderly hemiparetic stroke patients with cognitive impairment and the factors affecting their quality of life. [Subjects and Methods] The subjects of the study were 17 home-based elderly hemiparetic stroke patients with cognitive impairment (8 males and 9 females, average age: 76.3 ± 10.5 years old). Their physical and psychological conditions, quality of life and other items were investigated. Nishimura's Mental State Scale for the Elderly was used for the cognitive impairment assessment. The Functional Independence Measure was used to assess activities of daily living, and the Japanese Quality of Life Inventory for the Elderly with Dementia was used to assess quality of life. [Results] The subjects' quality of life was affected by their cognitive impairment level and independence of activities of daily living. However, no correlations were observed between the quality of life of the homebound elderly hemiparetic stroke patients with cognitive impairment, age, gender or care-need level. [Conclusion] In order to improve the quality of life of homebound elderly hemiparetic stroke patients with cognitive impairment, assistance helping them to maintain their cognitive abilities and on-going rehabilitation for improving activities of daily living independence are required.

Relationships between problematic behaviors and motor abilities of children with cerebral palsy.

[Purpose] This study aimed to examine whether motor abilities of children with cerebral palsy are related to their problematic behaviors. [Subjects] The subjects were children with mental retardation who were undergoing physical therapy. [Methods] Twenty-one examiners, 13 physical therapists, and 8 occupational therapists treated and examined the subjects by using the Japanese version of the Aberrant Behavior Checklist. The Japanese version of the Aberrant Behavior Checklist scores were compared between the Gross Motor Function Classification System I to III (12 subjects) and Gross Motor Function Classification System IV and V groups (17 subjects). [Results] Lethargy and stereotypy scores significantly differed between the groups, proving that patients with Gross Motor Function Classification System levels IV and V have more severe problematic behaviors. [Conclusion] In this study, only five types of problematic behaviors, namely irritability, lethargy, stereotypy, hyperactivity, and inappropriate speech, were examined. Despite this limitation, the study clarifies that problematic behaviors of children with cerebral palsy, except lethargy and stereotypy, have little relationship with their motor abilities.

Factors that affect the quality of life of community-dwelling elderly women with musculoskeletal disorders.

[Purpose] This study aimed to examine the quality of life (QOL) of community-dwelling elderly women with musculoskeletal disorders and factors that affect it. [Subjects] The subjects were 27 community-dwelling elderly women with musculoskeletal disorders (mean age: 76.3 ± 7.4 years). Their physical and psychological conditions, QOL, and other characteristics were researched. [Methods] The Japanese version of Life-Space Assessment was used to assess the subjects' daily life activities; the Japanese version of Fall Efficacy Scale (FES), to assess their fear of falling; the Geriatric Depression Scale (GDS 15), to assess their depression status; and the Life Satisfaction Index K (LSIK), to assess their QOL. [Results] The results indicated that the number of family members living together, degree of pain, fear of falling, and depression affect the LSIK scores of the community-dwelling elderly women with musculoskeletal disorders. [Conclusion] The study results suggest that the LSIK scores of community-dwelling elderly women with musculoskeletal disorders can be improved by easing their pain, improving their physical abilities to prevent falls, and improving their mobility. The results also suggest that continuing rehabilitation treatment is required.

Effect of exercise at light loads with manipulative resistance on infraspinatus, trapezius (upper fiber) and deltoid (middle fiber) muscle activities in shoulder joint elevation.

[Purpose] To clarify rotator cuff muscular activity in the raised position of the closed kinetic chain (CKC) exercise. [Subjects] Twenty-nine cases were studied, 19 men and 10 women (average age 21.5 ±4.7 years old, average body weight 60.1 kg ±11.4). [Methods] To determine the effects of the closed kinetic chain exercise on the upper limb, we measured the surface EMG of the infraspinatus muscle, the trapezius (upper fiber) and the deltoid (middle fiber) with the arm elevated. [Results] Our results show that at an elevation angle of 150° in the scapular plane of the upper limb, with 5% body weight load, the EMG activities of the infraspinatus muscle are approximately 30% of maximum voluntary contraction (MVC). [Conclusion] The raised position of the CKC exercise is effective in physical therapy for functional recovery of the infraspinatus muscle.

The role of physical therapists in introducing assistive products for the home-bound elderly disabled.

[Purpose] This study explored the roles of physical therapists (PTs) in introducing assistive products, which are essential for living securely and stably at home, and examined how PTs can fulfill these roles more efficiently and effectively. [Subjects and Methods] A questionnaire on introducing assistive products was administered to PTs working at randomly selected hospitals, health-care facilities for the elderly requiring long-term care, home-visit nursing stations, and other such facilities and to PTs providing physical therapy directly to the home-bound elderly disabled. The subjects of the study were 77 PTs who returned valid responses. [Results] For awareness of systems for assistive product's introduction, PTs were more aware of the system based on the Long-Term Care (LTC) Insurance Act than the system based on the Act on Welfare for the Home-Bound Elderly Disabled. For PTs handling assistive product's introduction for the home-bound elderly disabled, approximately 91% of the respondents answered that they had handled some cases of assistive product's introduction, and PTs with longer clinical experience had handled more assistive product's introduction cases. [Conclusion] The results demonstrated that PTs understand the work involved in introducing assistive products work well and that they handle it. The results, however, also suggested that educational and operational improvements are urgently required for PTs introducing assistive products essential for the lives of the home-bound elderly disabled.

Relationships between Gross Motor Abilities and Problematic Behaviors of Handicapped Children in Different Age Groups.

[Purpose] In this study, we examined problematic behaviors of independent-walking and non-independent-walking handicapped children in the infant, school child and adolescent development phases, using the Japanese version of the Aberrant Behavior Checklist (ABC-J) to determine if such behaviors relate to their gross motor abilities. [Subjects and Methods] The subjects were 86 handicapped children who were receiving physical therapy. The subjects were classified into three groups by age. Using the Gross Motor Function Classification System (GMFCS), each group was further divided into an independent-walking group and non-independent-walking group. Thirteen physical therapists and 8 occupational therapists, who were treating the subject children, rated the subjects using the ABC-J. [Results] Significant differences were observed between the independent-walking and the non-independent-walking groups in the stereotypy and lethargy scores of infants. [Conclusion] For schoolchildren and adolescents, no significant differences were observed between the independent-walking and the non-independent-walking groups in their problematic behavior scores.

Factors affecting quality of life of the homebound elderly hemiparetic stroke patients.

[Purpose] This study examined the quality of life (QOL) of homebound elderly hemiparetic stroke patients and factors that affect it. [Subjects] The subjects of the study were 21 homebound elderly hemiparetic stroke patients who were 65 years old or over and required care for daily living (12 males and 9 females, average age: 79.3 ± 8.4 years old). Their physical and psychological conditions, QOL, and other characteristics were researched. [Methods] The Functional Independence Measure (FIM) was used for the activities of daily living (ADL) assessment, and the MOS 36-Item Short-Form Health Survey (SF-36, Japanese version 1.2) was used for the QOL assessment. [Results] No correlations were observed between the QOL of homebound elderly hemiparetic stroke patients and their age and gender. However, the results showed that their QOL was affected by their independence in ADL, bedridden degree, and care-need level. [Conclusion] These results suggest that in order to improve the QOL of homebound elderly hemiparetic stroke patients, ongoing rehabilitation to improve independence in ADL and lower the bedridden degree and care-need level is required.

In situ 3D crystallographic characterization of deformation-induced martensitic transformation in a metastable Fe-Cr-Ni austenitic alloy by X-ray microtomography.

Excellent strength-ductility balance in metastable Fe-Cr-Ni austenitic alloys stems from phase transformation from austenite (fcc structure) to α' martensite (bcc structure) during deformation, namely deformation-induced α' martensitic transformation (DIMT). Here, DIMT in a metastable Fe-17Cr-7Ni austenitic alloy was detected in situ and characterized in three dimensions (3D) by employing synchrotron radiation X-ray microtomography. This technique utilizes refraction contrast, which is attributable to the presence of phase boundaries between the parent austenite and the newly formed α' martensite phase. By combining microtomography and position-sensitive X-ray diffraction, we succeeded in crystallographically identifying multiple α' martensite phases continuously transformed in four groups from a single parent austenitic phase.

Comparison of problematic behavior according to the ryouiku techou standard.

[Purpose] We compared problematic behaviors of children according to the severity of their mental retardation (MR) of intellect as categorized by the Ryouiku Techou in this study, to investigate the influence of MR of intellect on children's problematic behaviors. [Subjects] The subjects were 86 mentally retarded children undergoing physical therapy at hospitals and other facilities. [Methods] The examiners were 13 physical therapists and 8 occupational therapists who worked at the hospital and knew the children well. The examiners individually assessed the subjects using the Japanese version of the Aberrant Behavior Checklist. The subjects were divided into two groups (A and non-A) according to the Ryouiku Techou standard. [Results] No significant differences were observed between the groups except in the items of stereotypy and lethargy. [Conclusion] Problematic behaviors other than stereotypy and lethargy were not influenced by the Ryouiku Techou standard.

The Role of Physical Therapists in Living Environment Maintenance of the Home-bound Elderly Disabled.

[Purpose] This study explored the roles of physical therapists (PTs) in living environment maintenance, which is essential for living securely and stably at home, and examines how physical therapists can fulfill these roles more efficiently and effectively. [Subjects and Methods] A questionnaire on living environment maintenance was given to PTs working at randomly selected hospitals, health care facilities for the elderly requiring long-term care, home-visit nursing stations, and other such facilities and directly providing physical therapy to the home-bound elderly disabled. The subjects of the study were 77 PTs who returned valid responses. [Results] For awareness of systems for living environment maintenance, PTs were more aware of the system based on the Long-Term Care (LTC) Insurance Act than the system based on the Act on Welfare for the Home-Bound Elderly Disabled. PTs who have worked at two or more types of medical, welfare, and intermediate institutions were more aware of such systems than PTs who have worked at only one type. For PTs handling living environment maintenance for the home-bound elderly disabled, approximately 80% of respondents answered that they have handled some living environment maintenance, and PTs with longer clinical experience have handled more living environment maintenance cases. [Conclusion] The results demonstrated that PTs understand their living environment maintenance work well and handle the work. The results, however, also suggested that educational and operational improvements are urgently required for PTs handling living environment maintenance essential for the lives of the home-bound elderly disabled.

Structural aging of human neurons is opposite of the changes in schizophrenia.

Human mentality develops with age and is altered in psychiatric disorders, though their underlying mechanism is unknown. In this study, we analyzed nanometer-scale three-dimensional structures of brain tissues of the anterior cingulate cortex from eight schizophrenia and eight control cases. The distribution profiles of neurite curvature of the control cases showed a trend depending on their age, resulting in an age-correlated decrease in the standard deviation of neurite curvature (Pearson's r = -0.80, p = 0.018). In contrast to the control cases, the schizophrenia cases deviate upward from this correlation, exhibiting a 60% higher neurite curvature compared with the controls (p = 7.8 × 10-4). The neurite curvature also showed a correlation with a hallucination score (Pearson's r = 0.80, p = 1.8 × 10-4), indicating that neurite structure is relevant to brain function. This report is based on our 3D analysis of human brain tissues over a decade and is unprecedented in terms of the number of cases. We suggest that neurite curvature plays a pivotal role in brain aging and can be used as a hallmark to exploit a novel treatment of schizophrenia.

A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu.

Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe3+ to Fe2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (-OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss.

Reassigning CI chondrite parent bodies based on reflectance spectroscopy of samples from carbonaceous asteroid Ryugu and meteorites.

The carbonaceous asteroid Ryugu has been explored by the Hayabusa2 spacecraft to elucidate the actual nature of hydrous asteroids. Laboratory analyses revealed that the samples from Ryugu are comparable to unheated CI carbonaceous chondrites; however, reflectance spectra of Ryugu samples and CIs do not coincide. Here, we demonstrate that Ryugu sample spectra are reproduced by heating Orgueil CI chondrite at 300°C under reducing conditions, which caused dehydration of terrestrial weathering products and reduction of iron in phyllosilicates. Terrestrial weathering of CIs accounts for the spectral differences between Ryugu sample and CIs, which is more severe than space weathering that likely explains those between asteroid Ryugu and the collected samples. Previous assignments of CI chondrite parent bodies, i.e., chemically most primitive objects in the solar system, are based on the spectra of CI chondrites. This study indicates that actual spectra of CI parent bodies are much darker and flatter at ultraviolet to visible wavelengths than the spectra of CI chondrites.

X-ray nanoimaging of a transversely embedded carbon fiber in epoxy matrix under static and cyclic loads.

The initial stage of fatigue failure has not been thoroughly clarified for carbon fiber reinforced plastics (CFRPs). Although the initiation of fatigue cracks has been regarded to be interfacial debonding between the carbon fiber and polymer matrix, their detection among numerous carbon fibers, whose diameter is only 7 µm, is extremely difficult. In this study, a single carbon fiber was transversely embedded in a dumbbell-shaped epoxy sample to focus on the interfacial debonding and was observed using synchrotron radiation (SR) X-ray computed tomography (CT). A tabletop fatigue testing machine driven by a piezoelectric actuator was developed to apply static and cyclic loads along the beamline. SR X-ray multiscale CT imaging was conducted by switching between an absorption-contrast projection method (micro-CT) and a phase-contrast imaging-type X-ray microscopic CT (nano-CT). The carbon fiber was entirely captured by micro-CT and then magnified at both ends on the free surfaces. Nano-CT clearly visualized the interfacial debonding under 30 MPa static tensile load and the implication of the coalescence of nano-voids along the interface under 50 MPa. Under cyclic loads, the interfacial debonding gradually progressed under a 8-40 MPa sinusoidal stress after 10,000 cycles, whereas it did not propagate under a stress below 30 MPa.

Switching nanoprecipitates to resist hydrogen embrittlement in high-strength aluminum alloys.

Hydrogen drastically embrittles high-strength aluminum alloys, which impedes efforts to develop ultrastrong components in the aerospace and transportation industries. Understanding and utilizing the interaction of hydrogen with core strengthening elements in aluminum alloys, particularly nanoprecipitates, are critical to break this bottleneck. Herein, we show that hydrogen embrittlement of aluminum alloys can be largely suppressed by switching nanoprecipitates from the η phase to the T phase without changing the overall chemical composition. The T phase strongly traps hydrogen and resists hydrogen-assisted crack growth, with a more than 60% reduction in the areal fractions of cracks. The T phase-induced reduction in the concentration of hydrogen at defects and interfaces, which facilitates crack growth, primarily contributes to the suppressed hydrogen embrittlement. Transforming precipitates into strong hydrogen traps is proven to be a potential mitigation strategy for hydrogen embrittlement in aluminum alloys.