No abstract

Ceramics are high-strength and high-temperature resistant materials that are used in various functional parts. However, due to the high strength and brittleness properties, there are many difficulties in the fabrication of complex shapes. Therefore, there are many studies related to the fabrication of ceramic parts using 3D printing technology optimized for complex shapes. Among them, studies using photo-polymerization (PP) 3D printing technology with excellent dimensional accuracy and surface quality have received the most widespread attention. To secure the physical properties of sintered ceramic, the content and distribution of materials are important. This study suggests a novel 3D printing process based on a high-viscosity composite resin that maximizes the content of zirconia ceramics. For reliable printing, the developed 3D printers that can adjust the process environment were used. To minimize warpage and delamination, the divided micro square pattern images were irradiated in two separate intervals of 1.6 s each while maintaining the internal chamber temperature at 40 °C. This contributed to improved stability and density of the sintered structures. Ultimately, the ceramic parts with a Vickers hardness of 12.2 GPa and a relative density of over 95% were able to be fabricated based on a high-viscosity resin with 25,000 cps.

A 57Fe Mössbauer-effect study of autopsied lung tissue from Canadian asbestos mine workers is presented. The spectra typically show large quantities of iron storage protein. This exhibits a quadrupole-split doublet at room temperature and both a doublet and a Zeeman-split sextet at 4.2 K, due to a distribution of particle sizes. A comparison is made with Mössbauer spectra of lung tissue from an individual not occupationally exposed to respirable asbestos, and with spectra of respirable chrysotile asbestos taken from Canadian mines.

Phytoestrogen (PE) has received considerable attention due to the physiological significance of its estrogenicity. Flemingia strobilifera (FS) has been used as a folk medicine in Asia for the treatment of inflammation, cancer, and infection; however, the estrogenic effects and chemical components of FS have not yet been reported. We aimed to uncover the estrogenic properties and PEs derived from FS using phytochemical and pharmacological evaluation. PEs from FS extract (FSE) were analyzed by NMR, HPLC, and MS. To evaluate estrogenic activity, FSE and its compounds were evaluated by in vitro and in vivo assays, including human estrogen receptor alpha (hERα) binding, estrogen response element (ERE)-luciferase reporter assays, and uterotrophic assays. FSE and its compounds 1-5 showed binding affinities for hERα and activated ERE transcription in MCF-7 cells. Additionally, FSE and compounds 1-5 induced MCF-7 cell proliferation and trefoil factor 1 (pS2) expression. In immature female rats, significant increases in uterine weight and pS2 gene were observed in FSE-treated groups. We identified estrogenic activities of FSE and its bioactive compounds, suggesting their possible roles as PEs via ERs. PEs derived from FSE are promising candidates for ER-targeted therapy for post-menopausal symptoms.