In vitro and in vivo antimicrobial properties of silver-containing hydroxyapatite prepared via ultrasonic spray pyrolysis route

Hydroxyapatite (HAp), with its high biocompatibility and osteoconductivity, readily absorbs proteins, amino acids and other substances, which in turn favor the adsorption and colonization of bacteria. To prevent bacterial growth and biofilm formation on HAp discs, silver-containing (1–20 mol%) HAp (Ag-HAp) powders were synthesized using an ultrasonic spray pyrolysis (USSP) technique. The X-ray diffraction (XRD) peaks were very broad, indicating low crystallinity, and this induced the release of Ag⁺ ions from Ag-HAp powders. In addition, a gradual increase in Ca^2 + ion release was observed. These results suggest that dissolution of Ca^2 + ion in Ag-HAp triggered the release of Ag⁺ ions.The antimicrobial efficacy of Ag-HAp disc was tested against Staphylococcus aureus. Samples with Ag contents of more than 5 mol% were found to be highly effective against bacterial colonization and biofilm formation in vitro. In vivo antibacterial tests using bioluminescent strains also showed reductions in the viability of bacteria with Ag-HAp (5 mol%) discs. Biocompatibility tests using a modified Transwell® insert method showed that Ag-HAp (5 mol%) discs have negative effects on osteoblast proliferation. These results indicate that Ag-HAp (5 mol%) has effective antibacterial activity and good biocompatibility both in vitro and in vivo together with good biocompatibility, thus confirming its utility as a bactericidal material.     

Measurement of hydrogen permeation due to atomic flux using permeation probe in the spherical tokamak QUEST

Particle retention and recycling in plasma fusion devices are generally associated with the diffusion of atomic hydrogen into the materials. The resulted permeation of atomic hydrogen is known as plasma driven permeation (PDP). This permeation may also be significant, even in the walls, which are not directly exposed to the plasma. Under similar conditions, the permeation flux (Γ_perm) of hydrogen through a 30 μm thick Ni membrane heated at 412-575 K has been measured in the spherical tokamak QUEST. Γ_perm is being measured during the scans of different operating parameters like RF power (P_RF), chamber pressure (P_chamber), discharge widths (τ_dis) and vertical magnetic field (B_Z). Simultaneously edge plasma density and spectral intensities of atomic (Balmer) lines and molecular (Fulcher) bands have been compared with the permeation measurements. A linear relationship has been established between the time integrated Γ_perm i.e. permeation fluence (Q_perm) and the time integrated H_α intensity i.e. H_α fluence (Q_α). Q_perm also shows a strong relationship with the edge plasma density and various spectral fluences. The obtained results are discussed for exploring the applicability of the permeation probes in measuring the atomic flux near the first walls.     

Association between Serum Biomarkers and Peripheral Neuropathy in Microscopic Polyangiitis

This study aimed to elucidate the pathomechanism of peripheral neuropathy (PN) in microscopic polyangiitis (MPA) and to identify biomarkers useful for diagnosis and severity assessment. Patients with MPA (n = 37) and other non-inflammatory neurological diseases (ONDs; n = 12) were enrolled, and the peripheral nerves of all patients were evaluated using nerve conduction studies. We compared the clinical characteristics and 14 serum biomarker profiles among patients with MPA and PN, MPA without PN, and ONDs. Patients with MPA had a higher prevalence of motor neuropathy than patients with ONDs. Among the patients with MPA, those with motor neuropathy had significantly higher total Birmingham Vasculitis Activity Scores and serum levels of C-reactive protein (CRP), tissue inhibitor of metalloproteinase-1 (TIMP-1), and interleukin-6 than patients without motor neuropathy. Multivariable analyses adjusted for age, serum CRP level, and diabetes mellitus showed that high serum levels of TIMP-1 were independently related to a diagnosis of motor neuropathy in MPA. Additionally, there were significant negative correlations between the serum levels of TIMP-1 and compound muscle action potential amplitudes. Serum levels of TIMP-1 may be associated with the pathomechanism of motor neuropathy in MPA and could be a useful biomarker for diagnosing and evaluating the severity of motor neuropathy in MPA.     

Gemcitabine–Paclitaxel Chemotherapy for Patients with Advanced Urothelial Cancer Refractory to Cisplatin-Based Chemotherapy: Predictive Role of PGK1 for Treatment Response to Cytotoxic Chemotherapy

An investigation of alternatives to immune checkpoint inhibitors for advanced urothelial cancer (aUC), with biologic information, is urgently needed. Clinical data for 53 patients who received gemcitabine–paclitaxel therapy (GP) as 2nd-line chemotherapy for aUC refractory to platinum-based chemotherapy were retrospectively reviewed. The efficacy and tolerability of GP were evaluated, and the predictive value of phosphoglycerate kinase 1 (PGK1) immunostained in surgical specimens was investigated for treatment outcomes in 1st- and 2nd-line chemotherapy. GP was associated with an objective response rate of 35.8% and a median overall survival duration of 12.3 months. Multivariate analysis showed that PS2 and 1st- and 2nd-line non-response are independent predictors of worse progression-free survival and that PS2 and 1st-line non-response are independent predictors of worse overall survival. Adverse events were manageable, and no therapy-related deaths occurred. Non-response rates to 1st-line chemotherapy were significantly higher in patients with a high expression of PGK1 in the nucleus than in those with low expression (p = 0.006). Our study demonstrates the efficacy and tolerability of 2nd-line GP for patients with aUC who are refractory to platinum-based chemotherapy. Moreover, PGK1 in the nucleus was predictive values for resistance to platinum-based chemotherapy in aUC.     

Evaluation of Plant Ceramide Species-Induced Exosome Release from Neuronal Cells and Exosome Loading Using Deuterium Chemistry

The extracellular accumulation of aggregated amyloid-β (Aβ) in the brain leads to the early pathology of Alzheimer’s disease (AD). The administration of exogenous plant-type ceramides into AD model mice can promote the release of neuronal exosomes, a subtype of extracellular vesicles, that can mediate Aβ clearance. In vitro studies showed that the length of fatty acids in mammalian-type ceramides is crucial for promoting neuronal exosome release. Therefore, investigating the structures of plant ceramides is important for evaluating the potential in releasing exosomes to remove Aβ. In this study, we assessed plant ceramide species with D-erythro-(4E,8Z)-sphingadienine and D-erythro-(8Z)-phytosphingenine as sphingoid bases that differ from mammalian-type species. Some plant ceramides were more effective than mammalian ceramides at stimulating exosome release. In addition, using deuterium chemistry-based lipidomics, most exogenous plant ceramides were confirmed to be derived from exosomes. These results suggest that the ceramide-dependent upregulation of exosome release may promote the release of exogenous ceramides from cells, and plant ceramides with long-chain fatty acids can effectively release neuronal exosomes and prevent AD pathology.     

Output power enhancement of a palmtop terahertz-wave parametric generator

Broadband terahertz (THz) waves were generated by optical parametric processes based on laser light scattering from the polariton mode of a nonlinear crystal. By using the parametric oscillation of a MgO-doped LiNbO3 crystal pumped by a nanosecond Q-switched Nd:YAG laser, we have realized a broadband, high-energy and compact THz-wave source. We report the development of a THz-wave parametric generator (TPG) using a small pump source with a short pulse width and a top-hat beam profile. These characteristics of the pump beam permit high-intensity pumping especially close to the output surface of the THz wave without thermal damage to the crystal surface. We also calculated the outcoupled THz wave for beams with two different intensity profiles: a top-hat beam (in this experiment) and a Gaussian beam (previously reported). The result shows the mechanism of the output energy and/or power enhancement.     

Micronization of dihydroartemisinin by rapid expansion of supercritical solutions

The purpose of this study was to prepare fine particles of antimalarial drug dihydroartemisinin (DHA) by rapid expansion of supercritical solutions (RESS) using carbon dioxide as supercritical fluid. The mechanical grinding by jet mill and additional vibration rod mill also was performed as a comparative method. In the RESS process, drug particles were prepared by varying processing conditions, including extraction condition, pre-expansion condition, nozzle diameter, nozzle temperature, and collecting distance. Particle size and morphology and physicochemical characteristics of the drug particles were investigated. The RESS process could produce the smaller drug particles (about 1-2 microm) when compared to mechanical grinding method (about 7 microm). All RESS processing parameters had an effect on size and morphology of drug particles. The particle size of drug was related to the solubility of drug in supercritical CO(2) at each processing condition. The fine particles of DHA (about 1 microm) with narrow size distribution could be obtained at extraction pressure of 18 MPa and extraction temperature of 32 degrees C, which was closed to the critical temperature of supercritical CO(2) whereas broad size distribution was obtained at extraction temperature of 60 degrees C. Powder X-ray diffraction study indicated that the RESS-processed particles were in crystalline form. The results revealed that RESS process is applicable for micronization of DHA.     

Low thermal conductivity of SrTiO3−LaTiO3 and SrTiO3−SrNbO3 thermoelectric oxide solid solutions

Electron-doped SrTiO₃ has been attracting attention as oxide thermoelectric materials, which can convert wasted heat into electricity. The power factor of the electron-doped SrTiO₃, including SrTiO₃-LaTiO₃ and SrTiO₃-SrNbO₃ solid solutions, has been clarified. However, their thermal conductivity (κ) has not been clearly identified thus far. Only a high κ (>12 W m⁻¹ K⁻¹) has been assumed from the electron contribution based on Wiedemann–Franz law. Here, we show that the κ of the electron-doped SrTiO₃ is lower than the assumed κ, and its highest ZT exceeded 0.1 at room temperature. The κ slightly decreased with the carrier concentration (n) when n is below 4 × 10²¹ cm⁻³. In the case of SrTiO₃-SrNbO₃ solid solutions, an upturn in κ was observed when n exceeds 4 × 10²¹ cm⁻³ due to the contribution of conduction electron to the κ. On the other hand, κ decreased in the case of SrTiO₃-LaTiO₃ solid solutions probably due to the lattice distortion, which scatters both electrons and phonons. The highest ZT was 0.11 around n = 1 × 10²¹ cm⁻³. These findings would be useful for the future design of electron-doped SrTiO₃-based thermoelectric materials.     

Enhancement of Fat Oxidation during Submaximal Exercise in Sedentary Persons: Variations by Medium-Chain Fatty Acid Composition and Age Group

Previous studies in recreational and trained athletes aged mostly in their 20s have reported that short-term ingestion of medium-chain triacylglycerols (MCT) enhances fat oxidation (FAO) during submaximal exercise. However, whether the FAO-enhancing effect of MCT with a different composition of medium-chain fatty acids (MCFA) occurs in older sedentary persons is unclear. The present study investigated the effect of MCT ingestion with different proportions of MCFA in sedentary participants in their 40's and 50's. Participants ingested 0 g of MCT (control), 6 g of octanoic acid-rich MCT (OAR), or 6 g of decanoic acid-rich MCT (DAR) for 14 days separated by a 14-day washout period in random order. Cumulative FAO (F_cv) during submaximal, fixed, and incremental exercise was evaluated at workload from 20 W to the appearance of a ventilation threshold (VT). During the 20 W fixed-load exercise, F_cv was significantly (p < 0.05) higher in the OAR than in the control. At appearance of VT, intervention effect of power output was significantly higher in the OAR and DAR than in the control. In a subgroup analysis by age, intervention effects of maximal FAO rate and oxygen uptake in the upper age subgroup were higher in the OAR and DAR than in the control. In a pooled analysis with age subgroup and diet, the integrated pooled estimate of F_cv during submaximal exercise was significantly higher in 6 g of MCT ingestion than 0 g ingestion. Our data show that the effect of MCT might differ depending on the age group and the proportion of MCFA, while MCT could enhance FAO during submaximal exercise.