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.

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.

[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.

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.

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.

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.

Photon extraction enhancement of praseodymium ions in gallium nitride nanopillars.

Lanthanoid-doped Gallium Nitride (GaN) integrated into nanophotonic technologies is a promising candidate for room-temperature quantum photon sources for quantum technology applications. We manufactured praseodymium (Pr)-doped GaN nanopillars of varying size, and showed significantly enhanced room-temperature photon extraction efficiency compared to unstructured Pr-doped GaN. Implanted Pr ions in GaN show two main emission peaks at 650.3 nm and 651.8 nm which are attributed to 3P0-3F2 transition in the 4f-shell. The maximum observed enhancement ratio was 23.5 for 200 nm diameter circular pillars, which can be divided into the emitted photon extraction enhancement by a factor of 4.5 and the photon collection enhancement by a factor of 5.2. The enhancement mechanism is explained by the eigenmode resonance inside the nanopillar. Our study provides a pathway for Lanthanoid-doped GaN nano/micro-scale photon emitters and quantum technology applications.

A case of pancreatic duct stones treated with electrohydraulic lithotripsy through a duodenal ulcer.

Video 1Crush the large-sized stones directly using an electrohydraulic lithotripsy device.

Size Control and Enhanced Stability of Silver Nanoparticles by Cyclic Poly(ethylene glycol).

Silver nanoparticles (AgNPs) are used in a wide range of applications, and the size control and stability of the nanoparticles are crucial aspects in their applications. In the present study, cyclized poly(ethylene glycol) (c-PEG) with various molecular weights, along with linear PEG with hydroxy chain ends (HO-PEG-OH) and methoxy chain ends (MeO-PEG-OMe) were applied for the Tollens' synthesis of AgNPs. The particle size was significantly affected by the topology and end groups of PEG. For example, the size determined by TEM was 40 ± 7 nm for HO-PEG5k-OH, 21 ± 4 nm for c-PEG5k, and 48 ± 9 nm for MeO-PEG5k-OMe when the molar ratio of PEG to AgNO3 (ω) was 44. The stability of AgNPs was also drastically improved by cyclization; the relative UV-Vis absorption intensity (A/A0 × 100%) at λmax to determine the proportion of persisting AgNPs in an aqueous NaCl solution (37.5 mM) was 58% for HO-PEG5k-OH, 80% for c-PEG5k, and 40% for MeO-PEG5k-OMe, despite the fact that AgNPs with c-PEG5k were much smaller than those with HO-PEG5k-OH and MeO-PEG5k-OMe.

PEGylation of silver nanoparticles by physisorption of cyclic poly(ethylene glycol) for enhanced dispersion stability, antimicrobial activity, and cytotoxicity.

Silver nanoparticles (AgNPs) are practically valuable in biological applications. However, no steady PEGylation has been established, which is essential for internal use in humans or animals. In this study, cyclic PEG (c-PEG) without any chemical inhomogeneity is physisorbed onto AgNPs to successfully PEGylate and drastically enhance the dispersion stability against physiological conditions, white light, and high temperature. In contrast, linear HO-PEG-OH and MeO-PEG-OMe do not confer stability to AgNPs, and HS-PEG-OMe, which is often used for gold nanoparticles, sulfidates the surface to considerably degrade the properties. TEM shows an essentially intact nanostructure of c-PEG-physisorbed AgNPs even after heating at 95 °C, while complete disturbance is observed for other AgNPs. Molecular weight- and concentration-dependent stabilization by c-PEG is investigated, and DLS and ζ-potential measurements prove the formation of a c-PEG layer on the surface of AgNPs. Furthermore, c-PEG-physisorbed AgNPs exhibit persistent antimicrobial activity and cytotoxicity.

Snare devices with thinner loop wire may provide higher performance for cold snare polypectomy in an experimental model.

Background and study aims Snare devices play an important role in treatment of intestinal polyps. However, there are no objective measurements for the characteristics of the various types of snare devices. Materials and methods Seven types of snare devices from four manufacturers were evaluated based on original measurements. The evaluated factors were stiffness, cutting quality, and change in force required for cutting depending on sheath shape. The latter two factors were evaluated by measuring the force required to cut 20 % gelatin cylinders, which simulated intestinal polyps. The cutting sharpness was evaluated by observing the sectional surface of cut gelatin cylinders using a stereomicroscope. The correlations between these measurements and characteristics of the snare devices were investigated. Results A strong positive correlation, with an R 2 value of 0.863, was shown between the force required to cut gelatin cylinders and loop wire diameter. Loop wire diameter also had a strong correlation, with an R 2 value of 0.7997, with the change in force required for cutting gelatin cylinders depending on sheath shape. No correlations were detected between loop stiffness and characteristics of snare devices. The edge-enhanced image revealed that the rougher surfaces of the gelatin cylinders were cut by snares with a thicker diameter. Conclusions Thinner loop wire may provide higher performance in cold snare polypectomy in an experimental model.

Topology and Sequence-Dependent Micellization and Phase Separation of Pluronic L35, L64, 10R5, and 17R4: Effects of Cyclization and the Chain Ends.

The topology effects of cyclization on thermal phase transition behaviors were investigated for a series of amphiphilic Pluronic copolymers of both hydrophilic-hydrophobic-hydrophilic and hydrophobic-hydrophilic-hydrophobic block sequences. The dye solubilization measurements revealed the lowered critical micelle temperatures (TCMT) along with the decreased micellization enthalpy (ΔHmic) and entropy (ΔSmic) for the cyclized species. Furthermore, the transmittance and dynamic light scattering (DLS) measurements indicated a block sequence-dependent effect on the clouding phenomena, where a profound decrease in cloud point (Tc) was only found for the copolymers with a hydrophilic-hydrophobic-hydrophilic block sequence. Thus, the effect of cyclization on these critical temperatures was manifested differently depending on its block sequence. Finally, a comparison of the linear hydroxy-terminated, methoxy-terminated, and cyclized species indicated the effect of cyclization to be unique from a simple elimination of the terminal hydrophilic moieties.

Physical activity and/or sedentary behaviour and the development of functional disability in community-dwelling older adults in Tsuru, Japan: a prospective cohort study (the Tsuru Longitudinal Study).

OBJECTIVES: To clarify the association between moderate-to-vigorous physical activity (MVPA) and/or sedentary behaviour (SB) and the incidence of functional disability (FD) in older adults. DESIGN: Prospective cohort study. SETTING: Local municipality of Tsuru, Yamanashi, Japan. We conducted a baseline survey in January 2016. Follow-up was commenced on 1 February 2016 and completed on 31 October 2018. PARTICIPANTS: All individuals (6661 people) aged >65 years who were independently living in the community were eligible. METHODS AND OUTCOME MEASURES: MVPA (min/week) and SB (min/day) were measured using self-administered questionnaires in 5311 independently living older adults who participated in this study. The follow-up period was 33 months, and the incidence of FD was objectively determined by experts. The participants were divided into three groups based on MVPA distribution (non-MVPA, 0 min; short-MVPA, 1-299 min and long-MVPA, ≥300 min/week) and into two groups based on the median value of SB (short-SB,<190 min; and long-SB, ≥190 min/day). The participants were also classified into six categories based on different combinations of MVPA and SB. Cox proportional hazards model was used to calculate the HR and 95% CI for FD development with MVPA, SB and a combination of these behaviours. RESULTS: Among the included participants, 2415 were male and 2896 were female. The mean ages (SD) of the male and female participants were 74.5 (6.8) and 74.9 (6.9) years, respectively. The total number of participants with chronic conditions was 3489 (65.7%). Using the non-MVPA group as the reference, the multivariable-adjusted HR (95% CI) was 0.68 (0.54 to 0.84) in the short-MVPA group and 0.53 (0.41 to 0.69) in the long-MVPA group. Regarding SB, the short-SB group had an HR of 0.86 (0.71 to 1.03) compared with the long-SB group. The combined behaviour showed the lowest HR in the long-MVPA and short-SB group 0.49 (0.34 to 0.72) and the long-MVPA and long-SB group 0.49 (0.34 to 0.68), respectively. CONCLUSIONS: Long-MVPA had a robust association with FD development, whereas short-SB had a modest association. Moreover, a combination of these behaviours had a stronger association than individual behaviours. If the identified associations are assumed to be causal in nature, these findings suggest that encouraging older adults to engage in MVPA and reduce SB in their daily lives could be effective to prevent or delay FD development.

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.

Precise Synthesis and Thermoresponsive Property of Poly(ethyl glycidyl ether) and Its Block and Statistic Copolymers with Poly(glycidol).

In this paper, we describe a comprehensive study of the thermoresponsive properties of statistic copolymers and multiblock copolymers synthesized by poly(glycidol)s (PG) and poly(ethyl glycidyl ether) (PEGE) with different copolymerization methods. These copolymers were first synthesized by ring-opening polymerization (ROP), which was initiated by tert-butylbenzyl alcohol (tBBA) and 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phosphoranylidenamino]-2Λ5,4Λ5-catenadi(phosphazene) (t-Bu-P4) as the catalyst, and then the inherent protective groups were removed to obtain the copolymers without any specific chain end groups. The thermoresponsive property of the statistic copolymer PGx-stat-PEGEy was compared with the diblock copolymer PGx-b-PEGEy, and the triblock copolymers were compared with the pentablock copolymers. Among them, PG-stat-PEGE, PG-b-PEGE-b-PG-b-PEGE-b-PG, and PEGE-b-PG-b-PEGE-b-PG-b-PEGE, and even the specific ratio of PEGE-b-PG-b-PEGE, exhibited LCST-type phase transitions in water, which were characterized by cloud point (Tcp). Although the ratio of x to y affected the value of the Tcp of PGx-stat-PEGEy, we found that the disorder of the copolymer has a decisive effect on the phase-transition behavior. The phase-transition behaviors of PG-b-PEGE, part of PEGE-b-PG-b-PEGE, and PG-b-PEGE-b-PG copolymers in water present a two-stage phase transition, that is, firstly LCST-type and then the upper critical solution temperature (UCST)-like phase transition. In addition, we have extended the research on the thermoresponsive properties of EGE homopolymers without specific α-chain ends.

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.

Bidirectional relationship between insomnia and frailty in older adults: A 2-year longitudinal study.

BACKGROUND: Most previous studies that examined the association of insomnia with frailty used cross-sectional designs. The temporal relationship between these factors is therefore largely unknown. This study aimed to examine the bidirectional relationship between insomnia and frailty by sex. METHODS: A 2-year longitudinal study involving all community-dwelling older adults living in a rural area in Japan (n = 3844). Validated measures of insomnia and frailty were employed. Insomnia was assessed using the Athens insomnia scale, and frailty using the Kihon checklist. We performed a cross-lagged panel model, adjusted for age, sex, years of education, employment status, self-rated health, complications (hypertension, diabetes, stroke, or osteoarthritis), BMI, physical activity, alcohol consumption, and smoking status, and assessed differences by sex. RESULTS: Poor sleep predicted the onset and worsening of frailty during follow up (standardized coefficient [95% confidence interval]: 0.076 [0.045, 0.107]). Frailty also predicted severe insomnia symptoms (0.074 [0.044, 0.104]). However, the temporal association between these conditions varied by sex. In older men, the effect of frailty on insomnia was stronger than that of insomnia on frailty. However, in women, the impact of insomnia on frailty was stronger than that of frailty on insomnia. CONCLUSIONS: The primary potential cause of the association between insomnia and frailty may vary by sex, being frailty in men and insomnia in women. Sex-specific interventions to improve sleep quality and duration, and maintain functional abilities in daily life may contribute to the prevention and management of both frailty and insomnia in older adults.

Establishment of a novel cell-based assay using HLA-transfected cells to detect HLA antibodies.

The detection of HLA antibodies is important in clinical practice, such as platelet transfusion refractoriness and transfusion-related lung injury. However, difficulties are associated with the preparation of panel cells for conventional HLA detection systems using intact cells, such as the immunocomplex capture fluorescence analysis (ICFA). Based on an ICFA analysis, HEK293 cells stably transfected with the HLA-A locus were used instead of peripheral blood mononuclear cells (PBMC). The reactivity, sensitivity, and stability of transfectants were examined. All 20 antisera to HLA-A identified by LABScreen® Single Antigen class I (LS-SA1) were reactive to our modified-ICFA (m-ICFA) and showed the same specificities as those in LS-SA1, indicating the cell surface expression and correct antigenicity of the HLA-A locus in transfectants. The expression of HLA class I antigens was similar between transfectants frozen for 6 years and those prior to freezing. In the reaction of the anti-A24 or anti-A33 antibody vs each transfectant, the index of m-ICFA was higher than that of WAKFlow® ICFA. Our m-ICFA also showed that false negative reactions sometimes observed in capture assays may be avoided. By using HLA-A transfectants as ICFA targets, we herein developed m-ICFA. Our m-ICFA may avoid false negative reactions of capture assay like enzyme-linked immunosorbent assay and can also be carried out in almost any laboratory without cell culture facilities.