Central Taiwan University of Science and Technology

StoS is a hybrid histidine kinase that, to date, has been investigated only in Xanthomonas oryzae pathovar oryzae. In this study, we elucidated the function and transcriptional regulation of the stoS gene in X. campestris pathovar campestris (Xcc). An stoS deletion mutant and its complemented strain were constructed to assess phenotypic characteristics. Inactivation of StoS markedly decreased tolerance to heat, sodium dodecyl sulfate, and hydrogen peroxide, impaired membrane integrity, and reduced stationary-phase survival, whereas complementation restored these phenotypes. Transcriptional mapping identified a guanine residue 22 nucleotides upstream of the start codon as the transcription start site. Promoter activity assays further revealed that stoS expression is regulated by nutrient availability and environmental stress. Together, these results demonstrate that stoS plays a crucial role in maintaining membrane stability and stress resilience in Xcc. By providing the first functional characterization of stoS in Xcc, this study extends its investigation beyond X. oryzae pathovar oryzae and advances current understanding of stress-adaptive regulation in Xanthomonas.

This study presents a novel surface modification strategy for the low-modulus beta-type Ti-13Nb-7Sn-4Mo alloy to enhance its bioactivity for biomedical implants. A hierarchical micro-/submicro-/nano-structured surface was developed, incorporating a Ca(1-x)SrxTiO3 layer and metallic Ag nanoparticles. Elemental analysis showed surface concentrations of 2.61 f 0.39 at.% Ca, 1.14 f 0.23 at.% Sr, and 0.21 f 0.14 at.% Ag. X-ray photoelectron spectroscopy confirmed the presence of TiO2, Nb2O5, SnO2, MoO2, MoO3, Mo2O5, CaTiO3, SrTiO3, and metallic Ag. Water contact angles of 23.7 degrees for NT-Ca and 29.1 degrees for NT-Ca-Sr-Ag indicated moderate surface hydrophilicity. In simulated body fluid, all samples initiated apatite formation within one day. However, the NT-Ca-Sr-Ag surface exhibited faster and denser apatite growth after 14 days compared to the NT sample. The average weight gains of the NT, NT-Ca, and NT-Ca-Sr-Ag samples were measured as 2.87 f 0.3 mg/cm2, 2.93 f 0.45 mg/cm2, and 3.10 f 0.4 mg/cm2, respectively. These results demonstrate that the hierarchical Ca(1-x)SrxTiO3/nanotube surface combined with Sr and Ag incorporation enhances the surface's apatite-forming ability. The presence of Sr may enhance bioactivity, while Ag provides potential antibacterial activity. Although antibacterial performance was not directly tested in this study, the combined incorporation of Ca, Sr, and Ag on a hierarchical surface structure represents a novel design strategy with clear clinical relevance for Ti-based implants.

Titanium (Ti) and its alloys are widely used as hard tissue implants due to their excellent mechanical strength, corrosion resistance, and biocompatibility. However, their bioinert nature limits osseointegration, requiring surface modification to enhance biological responses. In this study, a hierarchical micro/submicro/nano-textured bioactive surface was constructed on a metastable beta-type Ti-13Nb-7Sn-4Mo alloy using anodization, microwave annealing, and hydrothermal treatment with a sustainable Ca source. The microwave annealing process produced crystalline TiO2 nanotube arrays with either anatase or mixed anatase/rutile phases, allowing investigation of phase-dependent CaTiO3 formation while preserving nanotube morphology. Subsequent hydrothermal treatment employed oyster shell-derived biogenic Ca to synthesize CaTiO3 on the nanotube surfaces. The selective nucleation and growth of CaTiO3 on anatase versus rutile phases generated distinct surface architectures, with partial decoration by micron- and submicron-sized CaTiO3 crystallites at 180 degrees C and complete coverage at 190 degrees C. The anatase-rich surfaces (M500H180) exhibited more uniform CaTiO3 coverage, better preserved nanotube structure, and enhanced surface hydrophilicity, which collectively promoted surface-induced mineralization behavior, as evidenced by apatite formation after 14 days in simulated body fluid. This study demonstrates a novel, eco-friendly strategy for fabricating phase-controlled CaTiO3 coatings on Ti-based alloys using biogenic Ca, highlighting the synergistic effects of TiO2 crystalline phase, hierarchical surface morphology, and sustainable Ca sources. The developed surfaces offer both environmental and functional advantages, providing a promising strategy for phase-controlled ceramic surface functionalization on Ti-based alloys.

OBJECTIVES:Poor sleep quality and depressive symptoms are common among institutionalized older adults. This pilot study examined the preliminary effects of bedtime inhalation-based aromatherapy on sleep and mood. METHODS:A pilot, single-blind, two-arm randomized controlled trial was conducted in a Taiwanese long-term care facility. Thirty-seven residents completed the study (intervention: n = 19; control: n = 18). The intervention group inhaled bergamot and clary sage essential oils for 15 minutes nightly over four weeks, while the control group received unscented almond oil. Outcomes were assessed using the Geriatric Depression Scale-15 (GDS-15) and Pittsburgh Sleep Quality Index (PSQI). One participant in the intervention group discontinued due to mild intolerance. RESULTS:Compared with the control group, the intervention group showed greater improvements in sleep quality (B = 2.41, p < .001) and reductions in depressive symptoms (B = 2.28, p < .001). No serious adverse events occurred. CONCLUSIONS:Bedtime inhalation-based aromatherapy appears safe and feasible, with potential to improve sleep and mood in institutionalized older adults. CLINICAL IMPLICATIONS:Incorporating bedtime inhalation-based aromatherapy into routine care may provide a safe, complementary non-pharmacological approach to support sleep and mood in institutionalized older adults. These findings are preliminary and require confirmation in larger trials.