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Microplastics (MPs) have been identified as an emerging soil pollutant and a global environmental concern. Scientists have recently paid attention to the contamination of soil by MPs as their detrimental impacts on soil systems are largely unknown. MPs are considered to be vectors for other soil contaminants, such as potentially toxic elements (PTEs) and organic contaminants. PTEs are persistent contaminants and are often released into soils in large quantities. MPs adsorb PTEs, mainly via electrostatic attraction and surface complexation, and increase their mobility in soils. These complexes can be easily absorbed by plants; hence, the accumulation of PTEs in plants can be enhanced in both microplastic and PTE contaminated soils. Furthermore, there is a high risk of food chains contamination by PTEs due to crops grown in both microplastic and PTE-contaminated soils. Consequently, countermeasures including policy- and governance-based approaches that target circular economy as well as reduce, reuse, recycle (3R) applications are being discussed around the world to minimize the environmental contamination of MPs.

X-ray fluorescence (XRF) analysis is a widely used technique to measure plating thickness. Its main advantage resides in allowing simultaneous, non-destructive analysis of multilayered plated parts. The miniaturization and increasing complexity of electronic devices proliferated by advancements in smartphone functionality continues with the rise of microelectromechanical systems (MEMS). Consequently, the electronic components and features for these devices are becoming as miniscule as ever. In order to maintain the necessary quality of these components, the measuring and control of the plating thickness and composition is critical. For this application, an XRF plating thickness analyzer capable of high accuracy measurement in small areas is essential. Utilizing the latest X-ray focusing polycapillary technology with a high-sensitivity detector, modern XRF systems deliver high-precision measurements of nanometer-scale plating. The beam diameter of less than $20\ \mu \mathrm{m}$ (full width at half maximum, FWHM) not only allows plating thickness measurements, but also composition analysis, useful for solder bumps. This allows for an outstanding measurement repeatability, achieving precision of 1% RSD for gold plating at 100 A. Furthermore, the levels of irradiated energy are lower than those utilized in wavelength dispersive techniques (WDXRF), thus considerably reducing the potential damage to the sample. This paper discusses XRF as an analytical technique for determining the thickness of plated or coated layers applied to a substrate. The effects of layer structure and properties on multilayer XRF thickness measurements are investigated.

In 2013, the European Union expanded the list of hazardous substances contained in the RoHS Directive. In addition, certain phthalate esters, such as dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DIBP), will be categorized as RoHS-prohibited substances starting from July 2019. Although pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) is a promising analytical method for the screening of phthalate esters, we have developed a novel soft-ionization MS method that is quantitative as well as faster and more convenient for this purpose. The sample was measured three times, after providing the calibration curve using a powdery standard material of SPEX. The data collection time is 5 min, and continuous measurements are completed within 8 min per sample. The mass spectrum was corrected by dividing the intensity by the sample weight. For the coefficient of variation, DBP was 2.9%, BBP was 3.4%, DEHP was 3.6%, and good reproducibility was observed. Precise analyses of phthalate esters using traditional methods can require solvent extraction times of up to 24 h as well as special techniques. Therefore, a screening method that can be easily carried out by anyone within ten minutes is very attractive.

The microcalorimeter detects the energy of incidentX-ray photon by the slight temperature rise of a device at a very low temperature, and the detector of a superconducting transition-edge sensor (TES) microcalorimeter has been developed for the measurement of energy dispersive X-ray photons of the energy of 10 to 20 keV with the energy resolution better than 100 eV of FWHM value by having the counting rate over 100 counts per second. A FE-SEM with a detector of TES microcalorimeter (SEM-TES) has already been developed for the extra-high resolution energy-dispersive X-ray spectrometry system to apply in electron-microprobe chemical analyses. Recently, we developed the sensitive correct function on the observed X-ray intensity data measured in the system. Then, the high energy resolution of revised SEM-TES system is precisely able to determine the element contents on the sample. In addition, the chemical bonding states can be clarified by the fluorescent X-ray intensities in the lower energy region derived with a low accelerating voltage of SEM-TES system. We applied the revised SEM-TES system to analyze chemical state on the electrode of nanosheets-derived Hx(Ni1/3Co1/3Mn1/3)O2 for newly developing electrochemical capacitors. We investigated the chemicalstate of cations by not the M-lines but the L-beta and L-alpha lines as the lower energy lines having relative large contribution on chemical bonding. As a result, we revealed a specific chemical state of the Mn different from that of Li(Ni1/3Co1/3Mn1/3)O2 electrode in LiB, that was supported by the result of TEM-EELS analysis. These results show that the SEM-TES system can be a useful analytical tool for the chemical bonding state and electronic structure determinations in a wide range of materials.

Transition Edge Sensor (TES) is an energy dispersive X-ray detecting system with high energy resolution. The energy resolution of this system depends on the steepness of superconducting transition curve from normal to superconducting state, heat capacitance and the operating temperature. The TES is based on the dilution refrigerator cooled by about 100 mK. The energy resolution is calculated about 1-2 eV for the detector with maximum detecting energy as 10 eV. The energy resolution also depends on the superconducting current flowing through the TES device because the superconducting current is affected by the temperature stability of the refrigerator. The fluctuation of the superconducting current means the fluctuation of the X-ray spectrum peak center. We have developed the sensitivity correction system to stabilize the peak center of the X-ray spectrum. The peak center of X-ray spectrum correlates with heater power to keep the base temperature of TES device at a constant temperature. The peak center of X-ray spectrum is calibrated by monitoring the heater power at constant time interval using the correlation curve between the peak center of X-ray spectrum and heater power.

The electrochemical properties of layer-structured H x (Ni 1/3 Co 1/3 Mn 1/3 )O 2 were examined for the first time to evaluate its use as an electrode for an electrochemical capacitor in alkaline aqueous solutions. The protonated H x (Ni 1/3 Co 1/3 Mn 1/3 )O 2 (HNCM) was prepared by reacting Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 (LNCM) with an HCl aqueous solution. The HNCM exhibited a large capacitance of 720 F g −1 (290 mAh g −1 , −1 to 0.45 V vs. Hg/HgO) at a current density of 50 mA g −1 in 8 M KOH aqueous solution, which is the highest level for the bulk electrodes in aqueous solutions. High power density, that is a capacitance of 560 F g −1 at a large current density of 1500 mA g −1 , was also confirmed. The HNCM exhibited good cycle stability, especially in 1 M KOH aqueous solution. The HNCM was found to be a promising electrode material for electrochemical capacitors because of its large capacitance, high cycle stability, and high rate capability.

The electrochemical properties of MnO 2 nanosheet thin films were examined to determine the intrinsic electrochemical properties of MnO 2 nanosheets and the influence of a laminated structure on the electrode properties as cathodes for electrochemical capacitors in a mild alkaline system. The MnO 2 nanosheet thin films were prepared on an ITO substrate using electrophoretic deposition. The XRD patterns and SEM and STEM observations showed that films composed of nanosheets with large lateral sizes of approximately 1 μm (large-NS) had a homogeneous microstructure like a bulk material. Thin films composed of nanosheets with small lateral sizes of 50–100 nm (small-NS) had a heterogeneous microstructure with numerous pores. The small-NS film exhibited a large capacitance of 1200 F g − 1 at a small mass density of 0.57 μg cm − 2 and a low sweep rate of 3 mV s − 1 . The small-NS film maintained a large capacitance of 450 F g − 1 even at a high sweep rate of 600 mV s − 1 . The small-NS film exhibited a better rate capability than the large-NS film because of the fast ion diffusion through the heterogeneous microstructure with numerous pores. This heterogeneous microstructure with numerous pores was found to contribute to the good electrode properties of the nanosheet electrodes.

High-density β-calcium orthophosphate (β-Ca3(PO4)2, also called β-tricalcium phosphate: β-TCP) ceramics with submicrometer-sized grains were fabricated using a pulse-current pressure firing route. The maximum relative density of the β-TCP compacts was 98.7% at 1050 °C and this was accompanied by a translucent appearance. The mean grain size of the β-TCP compacts increased slightly with temperature to reach 0.78 μm at 1000 °C. However, upon further increasing the firing temperature to 1050 °C the mean grain size increased significantly to 1.6 μm. The extent of plastic deformation during tensile testing was examined at temperatures between 900 and 1100 °C using a strain rate in the range 9.26 × 10−5 to 4.44 × 10−4 s−1. The maximum tensile strain achieved was 145% for a test temperature of 1000 °C and strain rate of 1.48 × 10−4 s−1 and this was attributed to the relatively high density and small grain size.

Accelerations of bone-like apatite deposition and cell growth on an electrically polarized ceramic hydroxyapatite have been reported. A relationship between these phenomena was investigated in a previous report, and then it was suggested that osteoblast-like cell's (MC3T3-E1) growth had relevance to the mineral growth. The effect of the formed apatite layer especially appeared to be on the cell adhesion. The acceleration of cell proliferation on the polarized HAp has been shown using fibroblastic cell (L929) and nerve cell (SK-N-SH) lines, therefore the effect of the layer on L929 and SK-N-SH was investigated to support the mechanism of acceleration of cell proliferation by polarization of HAp. In this study, the effect of the bone-like apatite layer was not confirmed on L929 cell's growth. On the other hand, the acceleration of nerve cell's proliferation was confirmed on the formed apatite layer. However, the remarkable improvement of the cell adhesion of SK-N-SH was not confirmed on the apatite layer. Consequently, it was considered that the bone-like apatite containing serum protein obtained by the coprecipitation of bone-like apatite and serum protein has a pronounced role only in the activity of osteoblast-like cells.

In cell culture medium containing serum proteins, a layer with a great role in ostelblast-like cell’s growth formed on a HAp ceramics by a coprecipitation with a deposition of a bone-like apatite and an adsorption of serum proteins. The adsorption of proteins is influential in the apatite deposition and the cell adhesion. A component of serum albumin is forming < 80% of total serum proteins, therefore we focused on the serum albumin. The serum albumin was removed from fetal bovine serum by using an albumin removal kit, and then the albumin free cell culture medium was prepared. The bone-like apatite layer was quickly formed on the HAp ceramics in the albumin free medium, however the high cell adhesion property was not confirmed. As a result of investigation of an initial cell adhesion, the initial cell adhesion property of the bone-like apatite layer was not excellent even though the layer contained the serum proteins. Moreover, the layer without serum proteins showed a meager cell adhesion property in every time of the cultivation. Therefore, it was revealed that the adsorption of the serum proteins only on the surface was not enough to the improvement of the cell growth. And a few days cultivation was required for an appearance of the remarkable effect on the cell growth on the layer formed by a coprecipitation reaction about the bone-like deposition apatite and the serum proteins adsorption.

Autograft, allograft, and biomaterials had been developed for bone regeneration. In recent year, a tissue engineering technique has been paid much attention for next generation implant. A problem of bone tissue engineering to be solved is a development of the substrate that is suitable for cell adhesion, proliferation, and differentiation. A biomimic scaffold for tissue culture was proposed, and then a cell response on the scaffold was estimated. The scaffold composed by a calcium deficient apatite with an adsorbed serum protein was formed on a ceramic hydroxyapatite (HAp) and surface-modified titanium by a soaking in cell-culture medium supplemented with fetal bovine serum. Excellent results on cell proliferation and cell adhesion were obtained only on osteoblast-like cells (MC3T3-E1). An actin filament in narrow filopodium of the spindle-shaped MC3T3-E1 cells on the ceramic HAp had a regular course. On the other hand, ends of the actin filament of the widely spread cells on the apatite layer with serum protein were scattering. It was suggested that the scattering of the actin end showed an existence of fibronectin, and then tight adhesion would be obtained by the many focal adhesion. Accordingly, the effectiveness of the biomimic scaffold containing serum protein on cell growth was confirmed.

The conformation of organic compound deposited on hydroxyapatite (HAp) ceramics was manipulated by their surface charge induced by electrical polarization. The sintered HAp ceramics were electrically polarized in a d.c. field at 400 °C. The organic layers on the HAp ceramics were deposited from a toluene solution of phenyltrichlorosilane (PTCS). The results of contact angle measurements and IR spectroscopy clarified the organic layer containing the fragments of PTCS. The amount of the obtained layer on the positively charged surface was larger than those on the negatively charged and nonpolarized surfaces. The thickness of the layer on the nonpolarized surfaces was thinner than those on the polarized surfaces, based on the depth profiles of Ca2p and Si2p. Although the deposition prepared on the nonpolarized HAp surfaces from the PTCS solution was supposed to be a self-assembled layer including of phenyl–Si bond, the layers on the polarized HAp were aggregated irregularly. Consequently, the HAp ceramic surface charge induced by the polarization altered the electrostatic interaction to the organic compounds in nonaqueous system.

Controllability of crystal growth on polarized hydroxyapatite (HAp) associated with simulated body fluid (SBF) was studied. Polarizing microscopic observation showed the crystal layer with c-axis vertically oriented to the polarized HAp surface. Scanning electron microscopic observation (SEM) showed an initial growth of the crystal. Structurally and micromorphologically oriented particles were precipitated on the surfaces of polarized HAp ceramics. Confocal laser scanning microscopic observation (CLSM) revealed higher Ca2+ concentration near negatively polarized surfaces. The polarization on HAp may make the crystal deposition with an orientation, and an electrostatic field to the ambient ions.

An electrical field may affect osteogenesis. Since we found that hydroxyapatite (HA) ceramics may be polarizable, we hypothesized that electrically polarized HA may foster production of new bone in vivo. Both polarized and non-polarized HA ceramics were inserted into the subperiosteum spaces at the parietal bone area of rats. After 2, 4, and 8 weeks, the implant sites were examined histologically. Morphometric analysis revealed that new bone formation was accelerated on the negatively charged surface of the polarized HA (N-surface) at 2 weeks. The newly formed bone approached maturation at 4 weeks and was thicker on the N-surface than in the controls. By 8 weeks, newly formed bone in the controls was almost the same as that on the N-surface. These findings suggest that polarized HA is biocompatible and that bone formation on the N-surface is enhanced in the early stage of bone healing.

Adherence of cells to a surface, such as a biomaterial surface, can be significantly influenced by the surface charge on that material. The applicability of electrically charged hydroxyapatite ceramics to selective cell adhesion was examined, and we show that polarized hydroxyapatite has significant effects on cell growth and adhesion. The surface charge applied to polarized hydroxyapatite promotes (i) enhanced colony formation of osteoblast-like cells, (ii) activation of gap junctions, and (iii) specific orienting of neuroblastoma cells. These findings will be of great utility and have significance in applications of tissue engineering, for example, in potential treatments for osteoporosis.

Growth enhancement of the bone-like layer on electrically polarized hydroxyapatite was investigated. Dense hydroxyapatite ceramics were electrically polarized in a dc field. For estimation of the bone-like grown layer on the polarized hydroxyapatite ceramic surfaces, polarized specimens were immersed not only in a simulated body fluid (SBF) with the inorganic ion-concentrations equal to those of human blood plasma, but also in minimum essential medium (MEM), and in MEM supplemented with 10% foetal bovine serum. After several days of immersion, the grown crystal layers were observed by scanning electron microscopy, and analyzed by X-ray diffraction and IR spectroscopy. As a result, the bone-like hydroxyapatite crystals grew rapidly on the negatively polarized surface, while the growth was restricted on the positively polarized surface both in SBF and MEM. The morphology of the grown layers on the polarized surface was different among the immersion fluids. The growth enhancement of the bone-like layer on the polarized HAp was demonstrated in multiple ions based on inorganic and organic groups. It was considered that the charged surfaces of the polarized HAp ceramics accelerated the growth of the bone-like layer on the negatively polarized surface, but was inhibited on the positively polarized surface.

Nanosheet-derived Hx(Ni1/3Co1/3Mn1/3)O2 was prepared by restacking (Ni1/3Co1/3Mn1/3)O2 nanosheets with large or small lateral sizes and their electrochemical properties in a 1 M KOH aqueous solution, microstructural factors were compared with those of bulk Hx(Ni1/3Co1/3Mn1/3)O2 (HNCM). The electrodes composed of small nanosheets exhibited very large capacitances of 1241 F·g−1 (395 mAh·g−1) at a current density of 50 mA·g−1, and 430 F·g−1 (100 mAh·g−1) at a large current density of 1000 mA·g−1. These large capacitances resulted from a heterogeneous layer structure with a large surface area and pore volume. The electrodes of large nanosheets, with a strongly interconnected microstructure and a surface area slightly larger than that of HNCM, exhibited good cycle stability and capacitances larger than that of HNCM. Microstructural control through the restacking of (Ni1/3Co1/3Mn1/3)O2 nanosheets improved the electrochemical properties of Hx(Ni, Co, Mn)O2.

The formation process of Ba2La8(SiO4)6O2 was clarified using thermogravimetry–differential thermal analysis (TG-DTA) and a high-temperature powder X-ray diffraction (HT-XRD) method. Phase changes identified from the HT-XRD data surprisingly corresponded to the weight loss and/or endothermic peaks observed in the TG-DTA curves. Raw material with the composition Ba2La8(SiO4)6O2 was completely reacted at 1400°C and produced only an apatite-type compound without a secondary phase. Moreover, the synthesis of Ba2+xLa8−x(SiO4)6O2−δ crystals with x= 0–2 was attempted using a solid-state reaction.

A functionally graded hybridization approach has been used in the formation of polymer-ceramic composites of polymethylmethacrylate (PMMA) and hydroxyapatite (HAp). HAp was successfully reinforced by sedimentary HAp distributions on a PMMA matrix using a centrifuge to avoid stress convergence on the interface. The stress-strain curves of the functionally graded PMMA-HAp composite showed sufficient mechanical strength with reduced brittleness. Scanning electron micrographs also showed evidence of exposed HAp on the surface of the composites.

The application of hydroxyapatite-sol as a drug carrier is being developed. Hydroxyapatite-sol which is a suspension consisting of hydroxyapatite nano-crystals, was synthesized using an ultrasonic homogenizer. The size of the crystals was 40 x 15 x 10 mm3 on average and their specific surface area was 100 m2/g. An amount of a glycoside antibiotics adsorbed onto hydroxyapatite nano-crystals was measured. The drug adsorbed 0.2 mg per 1 mg of hydroxyapatite. The affect of the drug adsorbed onto the hydroxyapatite was investigated using cancer cells. The drug, adsorbed onto the hydroxyapatite nano-crystals, inhibited cancer cell growth.

A low-temperature X-ray powder diffractometer has been developed and applied to the measurement of lattice constants of Bi2Sr2CaCu2O x superconductor at 80 K, only 3 K higher than the critical temperature. The relationship between the lattice constants and electrical resistivity was studied. The Bi2Sr2CaCu2O x sample was prepared by solid-state reaction and sintered by a hot-press system at 750°C. Lattice constants of the Bi2Sr2CaCu2C x were measured at 293 to 80 K. The electrical resistivity of the sample, measured by the standard four-probe method, reached 0 Ω cm at 77 K. The resistivity decreased rapidly along with rapid shrinkage of the c-axial length.

Recent X-ray diffraction analysis on electron-density distribution hasachieved a remarkable development, and structure refinement has been required tocorrect several factors such as extinction correction, thermal diffuse scattering, anharmonic thermal vibration. There were another problems on treatment of deformed distributions of 3d electron in transition-metal compounds. In this paper, three analytical factors to obtain accurate electron-density distributions, 3d electron-density distribution, anharmonic thermal vibration and extinction correction, were reviewed.

Objective The purpose of this study was to evaluate the pulpal response to an octacalcium phosphate (OCP)–based cement used as a pulp-capping material. Study design The pulps of 60 maxillary first molars of male Sprague-Dawley rats were exposed and then capped directly by using either OCP-based cement or a calcium hydroxide slurry (control). Histologic examinations were performed at 1, 2, and 5 weeks after the surgical procedure, and the results were analyzed statistically by using the Mann-Whitney U test (P Results One week after pulp capping, the initial formation of reparative dentin in the exposed areas was more notable in the calcium hydroxide group than in the OCP-based cement group. At 2 weeks, reparative dentin covered by a layer of odontoblast-like cells was observed in both groups. However, at 5 weeks, reparative dentin consisting of regular dentinal tubules was observed more frequently in the OCP-based cement group. Conclusion OCP-based cement allowed favorable healing processes to occur in the dental pulp.

The electrical polarization of ceramic HAp had an effect on the acceleration of bone restoration. Cell behavior in the bone-like growth layer was investigated. The deposits on the ceramic HAp was grown and formed layers by soaking in alpha-minimum essential medium supplemented with 10% fetal bovine serum (alpha-MEM supplemented with 10% FBS). The shapes of the adhering cells on the grown layer gradually changed from spindle to flat with growth of the layer. On the totally grown layer that was grown on the ceramic HAp by soaking in alpha-MEM supplemented with 10% FBS for 7 days, all the adhering cells were flat and the surface was filled with the grown cells. From these results, it was revealed that the grown layer on the ceramic HAp is one of the activation factors of cell growth. Consequently, cell growth was reinforced by acceleration of the layer growth on the negatively charged surface of the polarized ceramic HAp.

Hydroxyapatite (HA) coatings on Ti implants are made by the physical methods, mainly plasma spraying. We have developed a new chemical coating technique, thermal decomposition method. This method consisted of applying HA or perovskite (CaTiO3) coating solution containing organometals, phosphate ester (only in HA solution), and organic solvents onto the surface of Ti and then sintered it at 650°C. The process was repeated several times. The thin and homogeneous layer included an initial CaTiO3 layer with a thickness of 0.6 µm followed by an HA layer (2.4 µm) on top. The underlying CaTiO3 layer reduced oxidation of the Ti substrate and enhanced stability of the coating.

Hydroxyapatite microcrystals were synthesized by a neutral reaction of Ca(OH)2 suspension and H3PO4 aqueous solution using an ultrasonic homogenizer. The in vitro influence of hydroxyapatite microcrystals with the drug on cancer cell growth was investigated using Ca-9 and HSC-3 cells. The crystal shapes were plate-like, less than 0.1μm. The secondary particle sizes of the aggregated crystals dispersed into a physiological salt solution were determined as 1-10μm by a scattering laser diffraction method. The cell growth was drastically restricted by addition of hydroxyapatite microcrystals with doxorubicin hydrochloride compared to additions of doxorubicin hydrochloride alone and hydroxyapatite microcrystals alone. it was concluded that hydroxyapatite microcrystals are safe, absorbable, and very effective materials as new drug carriers for DDS.