Do the Impacts of Mentally Active and Passive Sedentary Behavior on Dementia Incidence Differ by Physical Activity Level? A 5-year Longitudinal Study.

BACKGROUND: It has not been determined whether mentally active sedentary behavior (MASB) and passive sedentary behavior (PSB) differentially affect cognitive function and whether these associations differ according to physical activity (PA) level. We examined the comparative impacts of MASB and PSB on dementia onset and aimed to understand whether the associations differed by PA level. METHODS: We conducted a 5-year longitudinal study involving all community-dwelling older adults in a rural area in Japan (n = 5,323). Dementia onset was examined using long-term care insurance data. PA was evaluated using the International Physical Activity Questionnaire and categorized as low (<2.5 metabolic equivalent of task [MET]-h/week), moderate (2.5-16.0 MET-h/week), or high (≥16.0 MET-h/week). We also assessed PSB (TV-watching time; <1 h/day, 1-3 h/day, ≥3 h/day) and MASB (Book-reading time; <10 min/day, 10-30 min/day, ≥30 min/day). To examine the associations of MASB and PSB with dementia onset, we performed the Fine-Gray models accounting for competing risk of death. RESULTS: During the follow-up period, 606 (11.4%) participants developed dementia. MASB was independently associated with a lower risk of dementia; the magnitude of the impact was significant at higher PA levels. There was no association between PSB and developing dementia across all PA levels. Furthermore, dementia risk for individuals with high PA levels and moderate or high MASB levels was approximately 60% lower than those with low PA levels and low MASB. CONCLUSION: Providing interventions to promote MASB, which reduces dementia risk, and PA, which increases MASB's effect on dementia incidence, can be beneficial in delaying or preventing dementia onset.

[Relationship between low back pain and physical activity and sitting time among community-dwelling older adults: A cross-sectional study].

Objectives　Japan has a high prevalence of low back pain among older adults requiring long-term care, which results in increasing expenses; therefore, prevention measures are necessary. This study aimed to examine the relationship between low back pain and physical activity and sitting time according to sex and age (65-74 years [young-old adults]; ≥75 years [old-old adults]) who had not received long-term care certification.Methods　A self-administered survey was mailed to 7,080 adults >65 years of age residing in Tsuru City (Yamanashi Prefecture, Japan) from January to February 2018, and had not received long-term care certification. Demographic information, health status (body mass index and medical history), lifestyle (dietary habits, alcohol consumption, and smoking), presence of low back pain, physical activity, sitting time, and social participation were measured. Low back pain was evaluated by asking, "Did you experience pain in parts of the body other than the knees for the past month?" Those who answered, "experienced low back pain" were categorized as "with low back pain". The short form of the International Physical Activity Questionnaire was used to assess physical activity, which was categorized into three groups: <150, 150-299, and ≥300 min/week. Sitting time was divided into two groups: <480 and ≥480 min/day. Multiple logistic regression analysis was used to determine the association between low back pain and physical activity and sitting time, according to sex and age.Results　Of the 7,080 individuals surveyed, 4,877 responded (2,217 male, 2,660 female), corresponding to a response rate of 68.9%. The number of older adults with low back pain was 1,542 (31.6%) including 673 (30.4%) males and 869 (32.7%) females. The rate of low back pain in young-old adults was 29.8% and 33.6% in old-old adults. There was no significant relationship between lower back pain and physical activity among the young-old adults. In the old-old adults, there was a significant relationship in the male ≥300 min group (odds ratio [OR] 0.66 [95%CI 0.48-0.89]), and in both female 150-299 (OR 0.69 [95%CI 0.48-0.99]) and ≥300 (OR 0.59 [95%CI 0.44-0.80]) min/week groups.Conclusion　The complaint rate for low back pain was approximately 30%, regardless of sex or age. These results suggest that interventions to prevent low back pain are necessary. Moreover, physical activity, but not sitting time, was associated with low back pain in both males and females among the old-old adults.

Topology-Dependent Interaction of Cyclic Poly(ethylene glycol) Complexed with Gold Nanoparticles against Bovine Serum Albumin for a Colorimetric Change.

Unique physical and chemical properties arising from a polymer topology recently draw significant attention. In this study, cyclic poly(ethylene glycol) (c-PEG) was found to significantly interact with bovine serum albumin (BSA), suggested by nuclear magnetic resonance, dynamic light scattering, and fluorescence spectroscopy. On the other hand, linear HO-PEG-OH and MeO-PEG-OMe showed no affinity. Furthermore, a complex of gold nanoparticles and c-PEG (AuNPs/c-PEG) attracted BSA to form aggregates, and the red color of the AuNPs dispersion evidently disappeared, whereas ones with linear PEG or without PEG did not demonstrate such a phenomenon. The interactions among BSA, AuNPs, and PEG were investigated by changing the incubation time and concentration of the components by using UV-Vis and fluorescence spectroscopy.

Trends in hepatitis E virus infection: Analyses of the long-term screening of blood donors in Hokkaido, Japan, 2005-2019.

BACKGROUND: After experiencing several cases of transfusion-transmitted hepatitis E (TT-HE) in Hokkaido, Northern Japan, hepatitis E virus (HEV) screening in blood donors, using a nucleic acid amplification test (NAT), was introduced in 2005. STUDY DESIGN AND METHODS: The frequency of HEV RNA-positive donations (2005-2019) was investigated, and the HEV RNA-positive specimens were phylogenetically analyzed. In August 2014, the 20-pooled NAT (20P-NAT) was replaced with an individual-NAT (ID-NAT) system. RESULTS: Until 2019, the frequency of HEV RNA-positive donors was 0.011% (289/2,638,685) with 20P-NAT and 0.043% (597/1,379,750) with ID-NAT, and no TT-HE cases were observed in Hokkaido. The prevalence among male, but not female donors, increased significantly between 2015 and 2019. Eighty-nine percent of HEV isolates from donors were genotype 3 and the remainder were genotype 4, and many clusters existed in each genotype. ALT levels at the time of donation were significantly higher in donors with genotype 4. Four subgenotypes, namely 3a (37%), 3b (41%), 3e (6%), and 4c (10%), comprised 94% of the total. During this period, the most identified subgenotype, 3a, transitioned to 3b. Majority of the HEV strains within the same clusters were detected in the same geographical region around the same period. Many of the human HEV isolates were shown to coexist closely with animal HEV isolates phylogenetically. CONCLUSION: In Hokkaido, multiple divergent HEV strains have been circulating, and small outbreaks of hepatitis E have occurred in the last 15 years. The results suggested that HEV NAT can contribute significantly in ensuring safety during blood transfusions.

Cyclization of PEG and Pluronic Surfactants and the Effects of the Topology on Their Interfacial Activity.

A series of cyclic surfactants were synthesized from a poly(ethylene glycol) (PEG) homopolymer and Pluronic surfactants L35, L64, P123, F68, 10R5, and 17R4, and their interfacial activity depending on the topology, chain ends, and block sequence was investigated. The cyclization was performed in a single step through etherification of the PEG homopolymer and the hydrophilic-hydrophobic-hydrophilic (ABA type) poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) (PEG-PPG-PEG), while the hydrophobic-hydrophilic-hydrophobic (BAB type) PPG-PEG-PPG was cyclized via acetalization. The cyclized surfactants were rigorously characterized by nuclear magnetic resonance spectroscopy and size exclusion chromatography. Cyclization of the surfactants induced a significant decrease in the hydrodynamic volume, which was more pronounced than that of the PEG homopolymer. Surface tension (γ) measurements indicated that the interfacial activity of the cyclized surfactants is stronger than their corresponding linear precursors, due to the increase in the surfactant density at the air-water interface as a consequence of the decreased molecular occupational area (A) upon cyclization. In the case of the PEG homopolymer, A considerably decreased from 410 Å2 for the linear PEG prepolymer to 100 Å2 for the cyclized PEG product. While the effects of chain-end groups were found to be limited to surfactants of relatively small molecular weights, the influence of cyclization depended strongly on the hydrophilic/hydrophobic ratio; the higher the PEG composition the surfactants had, the larger the decrease in γ and A; in other words, stronger enhancement in the interfacial activity was observed.

[Effect of an exercise program targeting knee pain on medical costs of elderly community-dwelling adults].

Objectives　The aim of this study was to examine the effect of an exercise program targeting knee pain on longitudinal medical costs (MC) of elderly community-dwelling adults.Methods　A community-based health program using specific exercises for improving knee pain was held from January to February, 2015. Twenty-eight individuals participated in the program (intervention group) and seventy individuals were selected from the respondents of a health and lifestyle survey by matching age, sex, and baseline value of severity of knee pain as a control group. Twenty individuals from the intervention group and twenty-nine from the control group were included in the final analysis. The changes in MC from 2014 to 2018 were compared between the two groups using a linear mixed-effects model.Results　The effect of the program on MC, estimated as a change from the baseline in 2014, showed a reduction of -5.6×103 yen/person (95% CI: -39.2-28.0) for the entire four-year period after the intervention. However, this difference was not significant. The changes in MC each year after the intervention were 9.3×103 yen/person (95% CI: -39.6-58.3) in 2015, -2.0×103 yen/person (95% CI: -44.4-40.5) in 2016, -10.3×103 yen/person (95% CI: -42.5-21.9) in 2017, and 8.2×103 yen/person (95% CI: -39.1-55.4) in 2018.Conclusion　The exercise program did not show a clear benefit in reducing the MC of elderly community-dwellers during the four years after the intervention. Further research with longer study durations and larger sample populations would be necessary to determine the effect of such intervention programs on MC.

Switching of Fluorescent Zn/Cd Selectivity in N,N,N',N'-Tetrakis(6-methoxy-2-quinolylmethyl)-1,2-diphenylethylenediamine by One Asymmetric Carbon Atom Inversion.

A quinoline-based hexadentate ligand, (S,S)-N,N,N',N'-tetrakis(6-methoxy-2-quinolylmethyl)-1,2-diphenylethylenediamine ((S,S)-6-MeOTQPh2EN), exhibits fluorescence enhancement at 498 nm upon addition of 1 equiv of Zn2+ (IZn/I0 = 12, φZn = 0.047) in aqueous DMF solution (DMF/H2O = 2:1). Addition of 1 equiv of Cd2+ affords a much smaller fluorescence increase at the same wavelength (ICd/I0 = 2.5, ICd/IZn = 21%). The trivalent metal ions such as Al3+, Cr3+, and Fe3+ also exhibit fluorescence enhancement at 395 nm (IAl/I0 = 22, ICr/I0 = 6 and IFe3+/I0 = 13). In contrast, meso-6-MeOTQPh2EN exhibits a Cd2+-selective fluorescence increase at 405 nm in the presence of 1 equiv of metal ion (ICd/I0 = 11.5, φCd = 0.022), while Zn2+ induces a smaller fluorescent response under the same experimental conditions (IZn/I0 = 3.3, IZn/ICd = 29%). In this case, the fluorescence intensities of meso-6-MeOTQPh2EN in the presence of a large amount of Zn2+ and Cd2+ become similar. This diastereomer-dependent, fluorescent metal ion specificity is derived from the Zn2+-specific intramolecular excimer formation in (S,S)-6-MeOTQPh2EN-Zn2+ complex and higher binding affinity of meso-6-MeOTQPh2EN with Cd2+ in comparison to Zn2+. The more conformationally restricted diastereomeric pair, namely, cis- and trans-TQDACHs (cis- and trans-N,N,N',N'-tetrakis(2-quinolylmethyl)-1,2-diaminocyclohexanes), both exhibit Zn2+-specific fluorescence enhancement because of the high metal binding affinity and intramolecular excimer forming property derived from the rigid DACH backbone.

TQOPEN (N,N,N',N'-Tetrakis(2-quinolylmethyl)-3-oxa-1,5-pentanediamine) Family as Heptadentate Fluorescent Cd2+ Sensors.

A quinoline-based heptadentate ligand, N,N,N',N'-tetrakis(2-quinolylmethyl)-3-oxa-1,5-pentanediamine (TQOPEN), exhibits a fluorescence increase (ICd/I0 = 25, ϕCd = 0.017) at 428 nm upon addition of 1 equiv of Cd2+. In contrast, 1 equiv of Zn2+ induces a negligible fluorescence change due to weak interaction (IZn/I0 = 2.5, IZn/ICd = 10%). In comparison with TQOPEN, the thia and aza derivatives TQSPEN and TQNPEN exhibit improved Cd2+/Zn2+ selectivity and higher Cd2+-binding affinity, respectively. The solid-state structures of mononuclear Cd2+ and hydroxide-bridged dinuclear Zn2+ complexes of TQOPEN were elucidated by X-ray crystallography. Although the crystal structure of the TQOPEN-Cd2+ complex exhibits a six-coordinate metal center, in which one quinoline weakly interacts with the Cd center (Cd···Nquinoline = 3.303(3) Å), a 1H NMR study at 233 K suggests that all quinolines interact with the Cd center to form a symmetrical seven-coordinate structure in solution. Theoretical calculations (TDDFT) support the flexible coordination environment around the Cd center, leading to intramolecular excimer formation with two quinoline moieties in the excited state. The importance of a heptadentate structure was further demonstrated by the lack of Cd2+ specificity with hexadentate ligands TriQOPEN (N,N,N'-tris(2-quinolylmethyl)-3-oxa-1,5-pentanediamine) and TQCPEN (N,N,N',N'-tetrakis(2-quinolylmethyl)-1,5-pentanediamine).

Errata: The relevant factors for knee pain in community-dwelling elderly: A cross-sectional study.

Nihon Koshu Eisei Zasshi(JAPANESE JOURNAL OF PUBLIC HEALTH), Vol. 63 (2016) No. 9 p. 560-568: p563(Tables 1, 2).

The prevalence and basic characteristics of knee pain in community-dwelling independent elderly: A complete survey.

Objectives　The objectives of this study were to determine the prevalence of knee pain in independent community-dwelling elderly people and to examine the basic characteristics (sex and age) of those experiencing knee pain.Methods　Survey on the health status and lifestyle habits was conducted for all (6,790) independent elderly who were 65 years or older, living in Tsuru City, Yamanashi Prefecture, Japan. The survey was carried out using a mailing questionnaire for 1 month from January 12 to February 11, 2016. Knee pain was defined as subjective pain in and around the knee joint in either one or both knees, on most days during the past month. Participants answered "Yes" if they were experienced knee pain, and "No" if they did not experience knee pain. Sex and age were investigated as basic characteristics of the participants by the questionnaire. The prevalence rate of knee pain was calculated as follows: the total number of people with knee pain divided by the total number of the respondents in the study. To examine the relationships between knee pain and age or sex, these basic characteristics were analyzed using a Chi-square test for the prevalence of knee pain within sex and age groups.Results　The number of survey respondents was 5,328 (response rate: 78.5%). The number of valid respondents with complete data was 5,186 (valid response rate: 76.4%). The number of subjects who responded "with knee pain" was 1,733. The prevalence rate of knee pain was 33.4%. In addition, sex and age demonstrated strong associations with the prevalence of knee pain (both, P<0.001). In other words, the prevalence rate was higher in the elderly women than in elderly men and increased with age.Conclusion　The present study suggested that one in three independently living elderly who live in medium-sized local municipalities in Japan experience chronic knee pain. The basic characteristics of a community-dwelling independent elderly with knee pain are to be a woman and older age.

A cross-sectional study on the factors related to cognitive decline in community-dwelling elderly.

AIM: The aim of this study was to examine the relationship between cognitive decline and physical activity, sitting time, and social participation among elderly people living independently in a local community. METHODS: In January 2015, 1,133 independently-living elderly individuals from a local Japanese community completed self-administrated questionnaires. A total of 929 participants completed the questionnaire (valid response rate: 82.0%). A multiple logistic regression analysis was conducted to examine the relationship between cognitive decline, physical activity, sitting time, and social participation. The factors related to cognitive decline were examined using three statistical models: (1) Model 1 was not adjusted for any factors; (2) Model 2 was adjusted for age, education level, smoking status, and drinking status; and (3) Model 3 was adjusted for the covariates in Model 2, plus depression. RESULTS: Cognitive decline was observed in 33% of men and 26% of women. The results indicated that decreased social participation was significantly related to cognitive decline in Models 1 and 2. For men, local community activity and political/economic activity were significantly associated with cognitive decline in Models 1 and 2. Among women, physical activity was significantly related to cognitive decline in Model 1. There was also a significant association between social participation and cognitive decline in Models 1 and 2; decreased volunteer activity was significantly related to cognitive decline in all three models. CONCLUSION: The results of the present study indicated that attending volunteer activities was significantly related to cognitive decline in women.

The relevant factors for knee pain in community-dwelling elderly: A cross-sectional study.

Objective To clarify the comprehensive relevant factors for knee pain in elderly men and women independently living in the community.Methods A health and lifestyle survey was conducted using 1,133 independent living elderly participants from a district in local community. Demographics, health status, lifestyle, knee pain, and physical activity were measured. Knee pain was evaluated based on whether the individual had reported experiencing pain when he or she was walking at the ground level during the last two weeks. The International Physical Activity Questionnaire Short Version assessed physical activity and sitting time. With regards to physical activity, subjects were classified into two groups -"non-sufficiency" or "sufficiency"- based on the recommendation by the World Health Organization of 150 minutes per week. With regards to sitting time, subjects were classified into two groups -"long time" or "short time"- based on a median value of 5 hours of sitting time per week. The demographic variables evaluated were age, sex, education, and marital status. Health status was evaluated by measuring the individual's Body mass index (BMI) and by their current disease history. Lifestyle was evaluated based on the individual's dietary habits, alcohol consumption, and smoking status. Each variable was classified into two groups. Multiple logistic regression analysis was used to examine the association of knee pain with physical activity, sitting time, dietary habits, drinking, smoking, and BMI in men and women. All variables were entered simultaneously as independent variables. The models were adjusted for sex, age, education, marital status, and health status.Results The number of valid respondents for the analysis was 801 (response rate: 70.7%), including 365 men (74.9±6.9 years) and 436 women (74.9±6.9 years). Survey responses for men and women who had reported experiencing knee pain suggested that, only physical activity was significantly associated with knee pain in men (P=0.035). The odds ratio (OR) and 95% confidential interval (95% CI) for knee pain were 0.605 and 0.308-0.964, respectively. In women, BMI and dietary habits were significant relevant factors for knee pain (P=0.023 and P=0.004, respectively). The OR for BMI and dietary habits were 0.595 and 0.547, respectively while the 95% CI were (0.380-0.931) and (0.364-0.823), respectively.Conclusion The results of this study suggest that physical activity was a related factor for knee pain in men. In contrast, BMI and dietary habits were relevant factors for knee pain in women.

Elucidating the structural changes of cellulose molecules and dynamics of Na ions during the crystal transition from cellulose I to II in low temperature and low concentration NaOH solution.

Low-concentration alkali treatments at low temperatures facilitate the crystal transition of cellulose I to II. However, the transition mechanism remains unclear. Hence, in this study, we traced the transition using in situ solid-state 13C CP/MAS NMR, WAXS, and 23Na NMR relaxation measurements. In situ solid-state 13C CP/MAS NMR and WAXS measurements revealed that soaking cellulose in NaOH at low temperatures disrupts the intramolecular hydrogen bonds and lowers the crystallinity of cellulose. The dynamics of Na ions (NaOH) play a crucial role in causing these phenomena. 23Na NMR relaxation measurements indicated that the Na-ion correlation time becomes longer during the crystal transition. This transition requires the penetration of Na ions (NaOH) into the cellulose crystal and a reduction in Na-ion mobility, which occurs at low temperatures or high NaOH concentrations. The interactions between cellulose and NaOH disrupt intramolecular hydrogen bonds, inducing a conformational change in the cellulose molecules into a more stable arrangement. This weakens the hydrophobic interactions of cellulose, and facilitates the penetration of NaOH and water into the crystal, leading to the formation of alkali cellulose. Our findings suggest that a strategy to control NaOH dynamics could lead to the discovery of a novel preparation method for cellulose II.

Impact of chemiluminescent enzyme immunoassay screening for human parvovirus B19 antigen in Japanese blood donors.

BACKGROUND: To reduce the risk of human parvovirus B19 (B19V) transmission through contaminated blood for transfusion and plasma-derived products, the Japanese Red Cross (JRC) Blood Centers introduced B19V antigen screening by chemiluminescent enzyme immunoassay (CLEIA-B19V) in 2008. STUDY DESIGN AND METHODS: Donor samples that were positive by CLEIA-B19V screening were tested for B19V DNA. The sensitivity of CLEIA-B19V was tested using samples of all three genotypes and B19V DNA-positive donations. B19V DNA-positive donations and pooled plasma were quantitatively assayed for B19V DNA. B19V DNA-positive donations were phylogenetically analyzed by polymerase chain reaction direct sequencing. RESULTS: The sensitivity of CLEIA-B19V was inferred to be approximately 6.3 log IU/mL with the genotype samples and 6.4 log IU/mL with B19V DNA-positive donor samples. Of 417 CLEIA-B19V-positive samples from 1,035,560 donations in Hokkaido, Japan, 101 were positive for B19V DNA. The 198 strains of B19V DNA-positive donations in Hokkaido over the past 15 years clustered exclusively with Genotype 1. After introduction of CLEIA-B19V, the viral load for B19V DNA in all 772 pooled plasma for fractionation from donors in nationwide Japan did not exceed 4 log IU/mL. CONCLUSION: CLEIA-B19V can detect all three genotypes of B19V (viral load >6.3 log IU/mL) and limit the viral load (<4 log IU/mL) in pooled plasma, and thus such screening has further reduced the risk of transfusion-transmitted B19V infection. These results show that CLEIA-B19V screening at the JRC Blood Centers can be an alternative approach to comply with recommendations regarding B19V in the United States and Europe.

All-Atom Molecular Dynamics Simulations of the Temperature Response of Poly(glycidyl ether)s with Oligooxyethylene Side Chains Terminated with Alkyl Groups.

Recently, experimental investigations of a class of temperature-responsive polymers tethered to oligooxyethylene side chains terminated with alkyl groups have been conducted. In this study, aqueous solutions of poly(glycidyl ether)s (PGE) with varying numbers of oxyethylene units, poly(methyl(oligooxyethylene)n glycidyl ether) (poly(Me(EO)nGE)), and poly(ethyl(oligooxyethylene)n glycidyl ether) (poly(Et(EO)nGE) (n = 0, 1, and 2) were investigated by all-atom molecular dynamics simulations, focusing on the thermal responses of their chain extensions, the recombination of intrapolymer and polymer-water hydrogen bonds, and water-solvation shells around the alkyl groups. No clear relationship was established between the phase-transition temperature and the polymer-chain extensions unlike the case for the coil-globule transition of poly(N-isopropylacrylamide). However, the temperature response of the first water-solvation shell around the alkyl group exhibited a notable correlation with the phase-transition temperature. In addition, the temperature at which the hydrophobic hydration shell strength around the terminal alkyl group equals the bulk water density (TCRP) was slightly lower than the cloud point temperature (TCLP) for the methyl-terminated poly(Me(EO)nGE) and slightly higher for the ethyl-terminated poly(Et(EO)nGE). It was concluded that the polymer-chain fluctuation affects the relationship between TCRP and TCLP.

Molecular Weight-Dependent Oxidation and Optoelectronic Properties of Defect-Free Macrocyclic Poly(3-hexylthiophene).

The redox behaviors of macrocyclic molecules with an entirely π-conjugated system are of interest due to their unique optical, electronic, and magnetic properties. In this study, defect-free cyclic P3HT with a degree of polymerization (DPn) from 14 to 43 was synthesized based on our previously established method, and its unique redox behaviors arising from the cyclic topology were investigated. Cyclic voltammetry (CV) showed that the HOMO level of cyclic P3HT decreases from -4.86 eV (14 mer) to -4.89 eV (43 mer), in contrast to the linear counterparts increasing from -4.94 eV (14 mer) to -4.91 eV (43 mer). During the CV measurement, linear P3HT suffered from electro-oxidation at the chain ends, while cyclic P3HT was stable. ESR and UV-Vis-NIR spectroscopy suggested that cyclic P3HT has stronger dicationic properties due to the interactions between the polarons. On the other hand, linear P3HT showed characteristics of polaron pairs with multiple isolated polarons. Moreover, the dicationic properties of cyclic P3HT were more pronounced for the smaller macrocycles.

Association of social participation (including inconsistent participation) with the progression of frailty among older adults: Community-based cohort study in Japan.

AIM: This study examined the relationship between continuity of social participation and progression of frailty among community-dwelling older adults, by baseline frailty level. METHODS: This study was part of a 3-year community-based cohort study among adults aged ≥65 years, living independently in a rural municipality in Japan. Mail surveys were carried out in 2016, 2018 and 2019. This study involved 2799 participants who responded to the question about social participation in every survey. Frailty was evaluated by Kihon Checklist total scores. Social participation was categorized into consistent non-participation, interrupted recent non-participation, interrupted recent participation and consistent participation. We assessed the relationship between social participation and change in frailty scores using general linear regression analysis, stratifying the participants into groups by their frailty level at baseline. RESULTS: There was a smaller frailty score increase in the robust (ß -0.61, 95% CI -0.99 to -0.22) and prefrail groups (ß -0.73, 95% CI -1.18 to -0.27) for consistent participation than consistent non-participation. Interrupted recent participation showed significant suppression in the prefrail group (ß -0.96, 95% CI -1.60 to -0.32). Social participation had no clear effect on progression in the frail group. CONCLUSIONS: Consistent social participation might reduce the progression of frailty in robust and prefrail people. Inconsistent participation might also help to reduce progression in prefrail older adults. It is important for prefrail older adults to return to their social activities and continue to engage as long as possible, even if their participation was intermittent in the past. Geriatr Gerontol Int 2023; 23: 25-31.

Thermoresponsive Property of Poly(N,N-bis(2-methoxyethyl)acrylamide) and Its Copolymers with Water-Soluble Poly(N,N-disubstituted acrylamide) Prepared Using Hydrosilylation-Promoted Group Transfer Polymerization.

The group-transfer polymerization (GTP) of N,N-bis(2-methoxyethyl)acrylamide (MOEAm) initiated by Me2EtSiH in the hydrosilylation-promoted method and by silylketene acetal (SKA) in the conventional method proceeded in a controlled/living manner to provide poly(N,N-bis(2-methoxyethyl)acrylamide) (PMOEAm) and PMOEAm with the SKA residue at the α-chain end (MCIP-PMOEAm), respectively. PMOEAm-b-poly(N,N-dimethylacrylamide) (PDMAm) and PMOEAm-s-PDMAm and PMOEAm-b-poly(N,N-bis(2-ethoxyethyl)acrylamide) (PEOEAm) and PMOEAm-s-PEOEAm were synthesized by the block and random group-transfer copolymerization of MOEAm and N,N-dimethylacrylamide or N,N-bis(2-ethoxyethyl)acrylamide. The homo- and copolymer structures affected the thermoresponsive properties; the cloud point temperature (Tcp) increasing by decreasing the degree of polymerization (x). The chain-end group in PMOEAm affected the Tcp with PMOEAmx > MCIP-PMOEAmx. The Tcp of statistical copolymers was higher than that of block copolymers, with PMOEAmx-s-PDMAmy > PMOEAmx-b-PDMAmy and PMOEAmx-s-PEOEAmy > PMOEAmx-b-PEOEAmy.