296 research outputs found

    Stability of vacancies in β-type Ti-15Mo-5Zr-3Al alloy fabricated via laser powder bed fusion

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    The structural instability in the β-type titanium alloys could affect the stability of vacancies. The stability of vacancies in a β-type Ti-15Mo-5Zr-3Al alloy, fabricated via laser powder bed fusion (LPBF), was investigated using positron annihilation spectroscopy and first-principles calculations. The observed positron lifetimes were close to the experimental and calculated bulk lifetime of Ti-15Mo-5Zr-3Al, which indicates that vacancies were not detected in Ti-15Mo-5Zr-3Al by positron lifetime measurements. Therefore, for the first time, it has been confirmed that quenched-in vacancies are not introduced in the LPBF-manufactured β-type Ti-15Mo-5Zr-3Al despite the fast cooling rate in LPBF process. This feature is preferable for the structural stability in biomedical and industrial applications. The calculated atomic displacement from the ideal bcc lattice positions decreased in β-type Ti-Mo alloys with increasing Mo concentration, indicating that the bcc structure was stabilized by the added Mo. The calculated vacancy formation energies of Ti atoms in β-type Ti-14.5Mo and Ti-27.0Mo alloys exhibited an increasing trend with an increasing number of neighboring Mo atoms. Mo atoms also increased the migration energies of the neighboring paths of vacancies. The calculated results for Ti-15Mo-5Zr-3Al suggest that, while the bcc structure was stabilized by the Mo atoms in Ti-15Mo-5Zr-3Al, the migration and formation energies were still low enough for the diffusion of vacancies.Mizuno M., Sugita K., Do K., et al. Stability of vacancies in β-type Ti-15Mo-5Zr-3Al alloy fabricated via laser powder bed fusion. Additive Manufacturing Letters 7, 100162 (2023); https://doi.org/10.1016/j.addlet.2023.100162

    Endosperm cell size reduction caused by osmotic adjustment during nighttime warming in rice

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    High night temperature (HNT) often reduces yield in field crops. In rice, HNT during the ripening stage diminishes endosperm cell size, resulting in a considerable reduction in final kernel weight; however, little is known about the underlying mechanisms at cell level. In this study, we performed picolitre pressure-probe-electrospray-ionization mass spectrometry to directly determine metabolites in growing inner endosperm cells of intact seeds produced under HNT conditions, combining with 13C feeding and water status measurements including in situ turgor assay. Microscopic observation in the inner zone suggested that approximately 24.2% of decrease in cell expansion rate occurred under HNT at early ripening stage, leading to a reduction in cell volume. It has been shown that HNT-treated plants were subjected to mild shoot water deficit at night and endosperm cell turgor was sustained by a decline in osmotic potential. Cell metabolomics also suggests that active solute accumulation was caused by a partial inhibition of wall and starch biosynthesis under HNT conditions. Because metabolites were detected in the single cells, it is concluded that a partial arrest of cell expansion observed in the inner endosperms was caused by osmotic adjustment at mild water deficit during HNT conditions.Fil: Wada, Hiroshi. Ehime University; JapónFil: Chang, Fang Yu. Ehime University; JapónFil: Hatakeyama, Yuto. Ehime University; JapónFil: Erra Balsells, Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Araki, Takuya. Ehime University; JapónFil: Nakano, Hiroshi. Ehime University; JapónFil: Nonami, Hiroshi. Ehime University; Japó

    GDP/GTP exchange reaction-stimulating activity of Rabphilin-3A for Rab3A small GTP-binding protein

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    AbstractRabphilin-3A is a putative target protein for Rab3A, a small GTP-binding protein particularly implicated in neurotransmitter release. Rabphilin-3A interacts more preferentially with GTP-Rab3A than with GDP-Rab3A. Moreover, Rabphilin-3A shows a weak activity to stimulate the GTPase activity of Rab3A and a strong activity to inhibit the Rab3A GTPase-activating protein (GAP)-stimulated GTPase activity of Rab3A. Here, we show that Rabphilin-3A has another activity to stimulate the GDP/GTP exchange reaction of Rab3A. Rabphifin-3A may keep Rab3A continuously in the GTP-bound form by converting again GDP-Rab3A, which may be converted from GTP-Rab3A by Rab3A GAP, to GTP-Rab3A, until the function of Rab3A is accomplished

    Effect of Ethanol in Paclitaxel Injections on the Ethanol Concentration in Exhaled Breath

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    BACKGROUND: Ethanol is included in certain injectable preparations of anticancer drugs to increase their solubility. Since the volume of ethanol in these preparations is approximately half of the total injection volume, the potential inhibitory effects of ethanol on the central nervous system cannot be disregarded, especially considering that patients may drive immediately after administration of the medication. Therefore, the concentration of ethanol was examined in exhaled breath after administration of paclitaxel, an anticancer medication containing ethanol. METHODS: The ethanol concentration in exhaled breath immediately after an intravenous infusion of paclitaxel was measured in 30 patients, using a balloon-type gas detector tube. Correlations between the concentration of ethanol in exhaled breath and the total amount of ethanol administered or the intravenous infusion speed were calculated. RESULTS: The mean ethanol concentration in exhaled breath was 0.028 ± 0.015 mg/L. The correlation between the ethanol concentration in exhaled breath and the total dose of ethanol was weak (R(2) = 0.25; p = 0.055), while the intravenous infusion speed showed a stronger positive correlation with the concentration of ethanol in the breath (R(2) = 0.49; p = 0.11). The maximum concentration of ethanol measured in exhaled breath (0.06 mg/L) was equivalent to 40% of the threshold for drunk driving, as specified in the Road Traffic Act in Japan. CONCLUSION: In this study, no patient had a breath ethanol concentration exceeding the legal threshold for drunk driving. However, it is still advisable for patients to avoid driving after receiving paclitaxel injections. When driving cannot be avoided, patients should wait for a sufficient time after receiving the injection before driving

    Metabolic coordination of rice seed development to nighttime warming: In-situ determination of cellular redox states using picolitre pressure-probe electrospray-ionization mass spectrometry

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    High night temperature (HNT) at the ripening stage severely affects both rice yield and quality. HNT accelerates embryo growth and chalky formation in the developing grains, accompanying with a diminishment of endosperm cell size. Although these responses may be physiologically interacted each other in the grains, what signals are involved in the accelerated embryo development remains undetermined. In this work, we have used picolitre pressure-probe electrospray-ionization mass spectrometry (picoPPESI-MS) to conduct single-cell metabolomics at several regions in HNT-treated grains, embryonic scutellum and outer endosperms in the basal (‘chalky region’ at maturation) and middle (‘translucent region’ at maturation as a reference) positions. Microscopic observations showed that HNT promoted cell expansion rate in the scutellum. When embryonic cell expansion rate reached the maximum, spatial differences in several metabolisms including ascorbate-glutathione (ASC-GSH) pathway and purine were detected, together with considerable sugar and amino acid accumulations in embryonic scutellum cells. There was no treatment difference in GSH content during active cell expansion in HNT-treated embryos, although an increase in GSH/GSSG ratio due to a reduction in oxidized glutathione (GSSG) content has been contrastingly observed. In the endosperms, greater ASC accumulation with a difference in ASC/dehydroascobic acid ratio has been also detected under HNT conditions. Since dormancy is often correlated with GSSG concentration, it is concluded that spatial regulation of GSH redox homeostasis detected at cell-level might be essential for dormancy alleviation and embryo growth accelerated in HNT-treated seeds.Fil: Chang, Fang-Yu. Ehime University; JapónFil: Hatakeyma, Yuto. Ehime University; JapónFil: Nonami, Hiroshi. Ehime University; JapónFil: Erra Balsells, Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Araki, Takuya. Ehime University; JapónFil: Nakano, Hiroshi. Ehime University; JapónFil: Wada, Hiroshi. Ehime University; Japó

    Shape selectivity in toluene disproportionation into para-xylene generated by chemical vapor deposition of tetramethoxysilane on MFI zeolite catalyst

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    Dependence of shape selectivity for para-xylene production by toluene disproportionation on conditions of chemical vapor deposition (CVD) of tetramethoxysilane on MFI (ZSM-5) zeolite were investigated in detail. The CVD after pelletization was necessary to obtain 0.7–1 mm particles with high selectivity. The influences of preparation conditions on the selectivity were investigated in detail to find the optimum conditions. The parent zeolite with small number of Brønsted acid sites on the external surface brought the high selectivity after the CVD. The catalyst prepared in the optimized conditions showed the selectivity 99.7% at ca. 10% of the toluene conversion

    Etiology of recurrent cystitis in postmenopausal women based on vaginal microbiota and the role of Lactobacillus vaginal suppository

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    Background: The vaginal microbiota can be altered by uropathogenic bacteria associated with recurrent cystitis (RC), and the vaginal administration of Lactobacillus have suggested certain effects to prevent RC. The relationship between vaginal microbiota and the development of RC has not been elucidated. We aimed to clarify the etiology of RC from vaginal microbiota and importance of vaginal Lactobacillus. Methods: Vaginal samples obtained from 39 postmenopausal women were classified into four groups: healthy controls; uncomplicated cystitis; RC; and prevention (prevented RC by Lactobacillus crispatus-containing vaginal suppositories). Principal coordinate analysis and beta-diversity analysis was used to assess 16S rRNA gene sequencing data from the vaginal microbiome. Results: Cluster analysis divided the vaginal bacterial communities among 129 vaginal samples into three clusters (A, B, and C). Fourteen of 14 (100%) samples from the RC group and 51 of 53 (96%) samples from the prevention group were in clusters B and C, while 29 of 38 (76%) samples from the healthy group and 14 of 24 (58%) samples from the uncomplicated cystitis group were in cluster A. The principal coordinate analysis showed that plots in the uncomplicated cystitis group were similar to the healthy group, indicating a large separation between the RC group and the uncomplicated cystitis group. On beta-diversity analysis, there were significant differences between the healthy group and the uncomplicated cystitis group (p = 0.045), and between the RC group and the uncomplicated cystitis group or the healthy group (p = 0.001, p = 0.001, respectively). There were no significant differences between the RC group and the prevention group (p = 0.446). The top six taxa were as follows: Prevotella, Lactobacillus, Streptococcus, Enterobacteriaceae, Anaerococcus, and Bifidobacterium. Among patients with RC, Lactobacillus was undetectable before administration of suppositories, while the median relative abundance of Lactobacillus was 19% during administration of suppositories (p = 0.0211), reducing the average cystitis episodes per year (6.3 vs. 2.4, p = 0.0015). Conclusion: The vaginal microbiota of postmenopausal women with RC is differed from healthy controls and uncomplicated cystitis in terms of lack of Lactobacillus and relatively dominant of Enterobacteriaceae. Vaginal administration of Lactobacillus-containing suppositories can prevent RC by stabilizing vaginal dysbiosis and causing a loss of pathogenic bacteria virulence

    Visualization of Charge Migration in Conductive Polymers via Time-Resolved Electrostatic Force Microscopy

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    Charge dynamics play an important role in numerous natural phenomena and artificial devices, and tracking charge migration and recombination is crucial for understanding the mechanism and function of systems involving charge transfer. Tip-synchronized pump–probe electrostatic force microscopy simultaneously permits highly sensitive detection, microsecond time resolution, and nanoscale spatial resolution, where the spatial distribution in static measurement (usual EFM) reflects differences in the carrier density and the time evolution reveals the surface carrier mobility. By using this method, carrier injection and ejection in sulfonated polyaniline (SPAN) thin films were visualized. Comparison of tr-EFM results of SPAN thin films with different doping levels revealed the individual differences in carrier density and mobility

    Clitoral Blood Flow Changes after Surgery with Tension-Free Vaginal Mesh for Pelvic Organ Prolapse

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    We measured basal clitoral blood flow by Doppler sonography to determine whether tension-free vaginal mesh(TVM) affects the clitoral blood flow and sexual function in women with pelvic organ prolapse (POP). We performed a prospective study of 22 patients who underwent TVM for POP. Clitoral blood flow was measured by Doppler ultrasound. The resistance index (RI), pulsatility index (PI), peak systolic velocity (PSV), and end-diastolic velocity (EDV) of the clitoral arteries were measured preoperatively and at 1, 3, and 6 months postoperatively. Female sexual function was also investigated with the Female Sexual Function Index (FSFI). The mean PI and RI were increased at 1 month and significantly decreased at 6 months postoperatively (p<0.05). In contrast, the mean PSV and EDV decreased at 1 month postoperatively and increased at 6 months postoperatively. These four parameters recovered to baseline levels at 6 months following surgery. Total FSFI scores improved significantly from 10.2±7.9 at baseline to 18.2±8.9 at 6 months postoperatively. Color Doppler ultrasonography is potentially useful in measuring clitoral blood flow in patients treated with TVM for POP. Prospective long-term studies are needed to evaluate the utility of this modality as a diagnostic and prognostic tool for female sexual dysfunction
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