Airborne and surface-residing microorganisms in indoor environments pose potential risks for infectious disease transmission. To address this issue, we developed a composite device combining a generator of vaporized free chlorine components with a fine particle removal filter. Field tests were conducted in occupied university classrooms to evaluate the device’s efficacy in reducing airborne bacterial loads. Airborne bacteria were sampled under three operational conditions [Electrolyzed (+)/Filter (+), Electrolyzed (−)/Filter (+), and Electrolyzed (−)/Filter (−)]. Significant reductions in bacterial counts were observed in the Electrolyzed (+)/Filter (+) condition, with a residual rate of 14.5% after 2.25 h (p = 0.00001). Additionally, surface contact tests demonstrated that vaporized free chlorine components, primarily consisting of hypochlorous acid (HOCl), reduced viable counts of E. coli, P. aeruginosa, and S. aureus by 59.0–99.7% even at a distance of 8.0 m. The concentrations of vaporized free chlorine components during operation remained within safe exposure limits (0–19 ppb), consistent with the effective range reported in prior literature (10–50 ppb). Computational fluid dynamics simulations confirmed the diffusion of vaporized free chlorine components throughout the room, including distant sampling points. These findings suggest the combined use of a vaporized free chlorine generator and a particulate filter effectively reduces microbial contamination in indoor environments, providing a promising approach for infection control in residential and public settings.

To better understand the evolution of the SARS-CoV-2 Omicron subvariants, we performed molecular evolutionary analyses of the spike (S) protein gene/S protein using advanced bioinformatics technologies. First, time-scaled phylogenetic analysis estimated that a common ancestor of the Wuhan, Alpha, Beta, Delta variants, and Omicron variants/subvariants diverged in May 2020. After that, a common ancestor of the Omicron variant generated various Omicron subvariants over one year. Furthermore, a chimeric virus between the BM.1.1.1 and BJ.1 subvariants, known as XBB, diverged in July 2021, leading to the emergence of the prevalent subvariants XBB.1.5 and XBB.1.16. Next, similarity plot (SimPlot) data estimated that the recombination point (breakpoint) corresponded to nucleotide position 1373. As a result, XBB.1.5 subvariants had the 5′ nucleotide side from the breakpoint as a strain with a BJ.1 sequence and the 3′ nucleotide side as a strain with a BM.1.1.1 sequence. Genome network data showed that Omicron subvariants were genetically linked with the common ancestors of the Wuhan and Delta variants, resulting in many amino acid mutations. Selective pressure analysis estimated that the prevalent subvariants, XBB.1.5 and XBB.1.16, had specific amino acid mutations, such as V445P, G446S, N460K, and F486P, located in the RBD when compared with the BA.4 and BA.5 subvariants. Moreover, some representative immunogenicity-associated amino acid mutations, including L452R, F486V, R493Q, and V490S, were also found in these subvariants. These substitutions were involved in the conformational epitopes, implying that these mutations affect immunogenicity and vaccine evasion. Furthermore, these mutations were identified as positive selection sites. These results suggest that the S gene/S protein Omicron subvariants rapidly evolved, and mutations observed in the conformational epitopes may reduce the effectiveness of the current vaccine, including bivalent vaccines such as mRNA vaccines containing the BA.4/BA.5 subvariants.

Far-infrared radiation (FIR) may influence vascular endothelial function, but its time-dependent molecular effects in adult arterial endothelial cells remain incompletely defined. We investigated FIR-induced responses in human femoral artery endothelial cells (HFAECs) using transcriptomic, proteomic, and phosphoproteomic analyses with three biological replicates per condition. Transcriptomic profiling 3 h after 30 min of FIR irradiation identified 424 differentially expressed genes (210 upregulated and 214 downregulated) among 16,081 genes, including endothelial-protective, nitric oxide-related, oxidative-stress, and heat-shock response genes. Proteomic analysis identified 13 differentially abundant proteins immediately after irradiation and 23, 75, and 61 proteins at 6, 12, and 24 h, respectively. These temporal changes involved mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling, vascular maturation, cytoskeletal organization, cell polarity, calcium/nitric oxide regulation, and stress adaptation. Phosphoproteomic analysis identified 12, 10, and 53 phosphorylation-related changes at 6, 12, and 24 h, respectively, indicating progression from actin and adhesion remodeling to junctional reorganization, focal adhesion maturation, and mechanosensing. Network analysis identified caveolin-1, β-catenin, and lamin B1 as hubs in a Rho guanosine triphosphatase-related module. Collectively, FIR induced a coordinated endothelial adaptive molecular response in HFAECs; functional studies are required to determine whether these changes enhance vascular repair.

Background: Lower extremity arterial disease (LEAD) occurs at a high frequency in dialysis patients and is associated with a poor prognosis. In recent years, intermittent infusion online hemodiafiltration (I-OHDF) combined with far-infrared therapy (FIR) has been reported as being useful in dialysis patients with LEAD. However, there are also reports of worsening of the ulcers and gangrene in some cases. Hot shot I-OHDF (HS I-OHDF), which involves intermittent infusion of heated dialysate, is reported as being more effective than conventional I-OHDF for improving the plasma refilling rate (PRR) and peripheral circulation. We report the case of a patient in whom a lower extremity ulcer healed only after we switched from I-OHDF + FIR to HS I-OHDF + FIR, and the usefulness of this treatment. Case presentation: The patient was a 41-year-old male dialysis patient with LEAD who showed worsening of the ulcers in the lower extremity before he was switched from I-OHDF plus FIR to HS I-OHDF plus FIR; we compared the changes in the lower extremity blood flow, PRR, degree of wound healing, and subjective symptoms over time after the switch to HS I-OHDF plus FIR as compared with the values prior to the switching. As compared with the values during I-OHDF plus FIR, the lower extremity blood flow and PRR increased markedly during HS I-OHDF plus FIR. The wounds in the lower extremity improved over time during HS I-OHDF plus FIR and showed complete healing after 6 months; evaluation by visual analog scales (VASs) showed improved scores for all of fatigue, pain, coldness, and insomnia, and the patient reported improved subjective symptoms. The mechanism underlying the effectiveness of HS I-OHDF plus FIR in promoting wound healing is unknown, however, we speculated that the temperature change in the intermittent infusion solution resulted in increased blood flow in the true capillaries (resting vessels) and transfer of the nonthermal effects of FIR to more peripheral vessels. Conclusions: This case demonstrates that combined use of HS I-OHDF with FIR can enhance the efficacy of FIR in dialysis patients with LEAD by increasing the lower extremity blood flow and PRR, which is useful for wound healing.

Vaporized free chlorine, primarily present as hypochlorous acid (HOCl), is increasingly used for indoor microbial control; however, virus-dependent susceptibility and its molecular determinants remain unclear. We evaluated virucidal effects under controlled indoor conditions (0–9 ppb) against echovirus 30 (E30), influenza A/H1N1, and human adenovirus type 3 (HAdV3). Infectious titers were quantified by TCID₅₀ assays. Computational fluid dynamics (CFD) simulations and gas-sensor measurements assessed spatial dispersion, and structural analyses examined oxidation-sensitive amino acid residues. Significant reductions in infectivity were observed for E30 (99.0%, p = 0.00727) and influenza A/H1N1 (99.9%, p = 0.000597), whereas no significant reduction was detected for HAdV3 (p = 0.142). Analyses including all data points without outlier exclusion confirmed the robustness of these findings. CFD indicated uniform dispersion, although spatial heterogeneity within the indoor environment cannot be excluded. These findings suggest that viral susceptibility to vaporized HOCl is associated with residue-level composition and structural context; however, this relationship should be interpreted as correlative rather than causal. Moreover, integration of molecular and structural analyses provides a plausible mechanistic framework, although direct biochemical validation remains necessary. Structural analyses showed lower proportions of oxidation-sensitive residues in adenoviral proteins compared with influenza A hemagglutinin (OR = 0.34–0.40, adjusted p < 0.001) and the E30 VP1 intermediate. Residues were clustered in surface-exposed functional domains in susceptible viruses.

Background: Intradialytic exercise is recommended to improve exercise capacity, physical function, and quality of life in patients undergoing maintenance hemodialysis (HD). However, objective and practical physiological indicators for monitoring circulatory responses during intradialytic exercise remain limited in routine clinical settings. Laser Doppler flowmeter (LDF) enables noninvasive assessment of microcirculatory blood flow and may provide a useful method for monitoring peripheral circulation during exercise. This study aimed to (1) evaluate changes in earlobe microcirculatory blood flow during intradialytic exercise, (2) examine its association with perceived exercise intensity, and (3) explore its potential as a real-time circulatory monitoring parameter. Methods: Seventeen patients undergoing maintenance HD participated in this observational study. A 20-min intradialytic exercise program consisting of lower-limb resistance and stretching exercises was performed during dialysis sessions. Bilateral earlobe blood flow and pulse rate were continuously measured using LDF. Relative changes from baseline were calculated at 5-min intervals (5, 10, 15, and 20 min). The stability index (SI), defined as the coefficient of variation of the blood flow signal, was calculated to evaluate microcirculatory stability. Perceived exertion was assessed using the modified Borg scale. Statistical analyses included paired t-tests, Wilcoxon signed-rank tests, and Pearson correlation analysis. Results: Earlobe blood flow increased significantly during intradialytic exercise compared with baseline, reaching a maximum increase of approximately 1.9-fold of the resting level. A strong positive correlation was observed between earlobe blood flow and perceived exertion assessed by the Borg scale ( r = 0.938, p < 0.001). Despite the increase in blood flow, the stability index did not change significantly during exercise, indicating that microcirculatory fluctuations remained stable throughout the exercise period. Conclusions: Earlobe blood flow increased during intradialytic exercise and correlated with perceived exertion, while microcirculatory variability remained stable. These findings indicate that earlobe blood flow may reflect acute peripheral circulatory responses to exercise. However, given the exploratory nature of this preliminary study, including the small sample size and lack of control conditions, further studies are needed to validate its clinical applicability.