Effect of chemical treatment on mineralization of C and N in Andosols rich in Al-humus complexes

Poster Sessio

Non-catalytic conversion of chitin into Chromogen I in high-temperature water

Epub 2019 June 21The non-catalytic conversion of chitin into N-acetyl-ᴅ-glucosamine (GlcNAc) derivatives such as 2-acetamido-2,3-dideoxy-ᴅ-erythro-hex-2-enofuranose (Chromogen I) was investigated in high-temperature water at 290–390 °C and 25 MPa with a reaction time of 0–180 min. High-temperature water treatment is a promising method for chitin conversion as it does not require the use of any additional organic solvents or ionic liquids. A semi-batch reactor was developed to control the reaction temperature and time. It was found that the chitin powder could be converted into a water-soluble fraction in ~90% yield, with Chromogen I being obtained in a maximum yield of 2.6%. Furthermore, a kinetic model was developed to estimate the reaction rate for the conversion of the chitin powder to the water-soluble fraction.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 136:994-999 (2019)journal articl

骨芽細胞様細胞MC3T3-E1における電位依存症L型カルシウムチャネルからのカルシウムの流入

This study was undertaken to confirm that there are voltage-dependent L-type Ca^ channels in osteoblastic MC3T3-E1 cells and that the type of Ca^ channel involved in the Ca^ entry is the L-type. We investigated the effects of a Ca^-free saline and Bay K 8644, an L-type Ca^ channel activator, on intracellular Ca^ concentration ( [Ca^]i). Although high K^+ (100mM) alone raised the [Ca^]i, high K^+ did not raise the [Ca^]i in the absence of extracellular Ca^. Bay K 8644 (1uM) augmented the high K^+-induced [Ca^]i rise. In conclusion, it is confirmed that Ca^ invades through the voltage-dependent L-type Ca^ channels in osteoblastic MC3T3-E1 cells

Biological performance of novel phosphate-based glass microspheres for mesenchymal stem cell therapy in osteoporotic patients

In this study, degradable phosphate-based bulk or porous glass microspheres (BGMS or PGMS), with nominal molar compositions of P45-(45P2O5-16CaO-24MgO-11Na2O-4Fe2O3) and P40-(40P2O5-16CaO-24MgO-20Na2O), were evaluated for cytotoxicity, cytocompatibility and osteogenic potential for Mesenchymal stem cell (MSC)-based therapy in osteoporotic patients. Evaluations were performed using direct-contact and indirect-contact bone marrow derived human MSC (hMSC)-based experiments, in addition to material characterisations such as morphology, elemental composition and degradation behaviour, which were correlated to the hMSC experiments. Degradation of microspheres (MS) was measured using a novel method where Scanning Electron micrographs was used to assess the number of MS with surface damage (cracks and peeling effect), over 42 days of degradation in culture medium. Results showed that after 42 days, 2%, 46% and 29% of P45 BGMS, P40 BGMS and P40 PGMS, respectively, had cracks or peeling off surfaces. The results for direct-contact hMSC-experiments showed that P45 BGMS supported 1.4 times more hMSCs than P40 BGMS over 31 days of culture period. However, P45 BGMS were not osteoinductive, possibly due to hydrophobic nature of this glass and its slower dissolution rate. On the other hand, in comparison to P45 BGMS, hMSCs seeded on P40 BGMS showed up to 1.7 times higher alkaline phosphatase (ALP) activity on Day 7, up to 1.5 times more collagen and at least 6 times more Ca deposited in extracellular matrix, in addition to osteocalcin on Day 21 of culture, which strongly indicated the osteoinductive nature of P40 BGMS. This effect was also confirmed through indirect-contact experiments where there was higher collagen and Ca production by hMSCs was observed after 25 days of culture in P40 BGMS-conditioned medium as compared to control (no MS) or P45-conditioned medium. Elemental analysis using Energy Dispersive X-Ray Spectroscopic (EDS) analysis revealed that the Ca-based porogen used in the manufacturing of PGMS, may have been retained on the edges of the pores in PGMS. Therefore, an acid-washing step was introduced at the end of manufacturing process in order to remove the porogen and limit the possible cytotoxic effect of porogen and excess calcium. Characterisation results indicated that acid washing changed the physicality of these microspheres without changing their chemical composition. For example, mean and mode pore window sizes on the surface of PGMS increased from 2.63 μm to 2.73 μm and from 1.15 μm to 1.53 μm, respectively, and closed porosity decreased by 27%, as a result of acid washing. However, more detailed EDS analysis revealed that the Ca-based porogen was not being completely removed from PGMS even after acid washing and this may need further investigation. Cytotoxicity evaluations over 7 days of elution (indirect-contact hMSC experiments) suggested that there was marked improvement in hMSC membrane integrity and metabolic activity in PGMS neat extracts after acid washing. Moreover, direct-contact hMSC experiments also showed higher DNA content on acid washed (AW) P40 PGMS over 7 days of culture. Therefore, based on these results, it was hypothesised that acid washing may have opened up some of the pores and removed some of the glass fragments from PGMS surface, which may have been responsible for cytotoxicity in non-AW PGMS. Direct-contact experiments also showed that over 42-day culture period, there was up to 1.6 times higher hMSC numbers in AW P40 PGMS as compared to P40 BGMS. However, this increase was much lower than the expected range as there was more than 10-fold increase in surface area after the introduction of porosity. This was probably due to presence of <5 μm and <10 μm pore window sizes and interconnection sizes, respectively, in these microspheres, which allowed limited penetration of hMSCs into the porous structures. There was also evidence of at least 2 times more ALP activity up to day 42 of culture and up to 1.7 times more collagen production by day 21 of culture, in case of AW P40 PGMS as compared to P40 BGMS, which strongly indicated a positive effect of porosity on osteogenesis. Interestingly, there was also lower Ca and P deposited by hMSCs in porous microspheres, which was in line with the observations made through indirect-contact experiments, where there was lower collagen and Ca production by hMSCs in P40 PGMS-conditioned medium as compared to P40 BGMS-conditioned medium. This negative effect of PGMS was hypothesised due to excess release of glass fragments/particulates and calcium ions into the medium, possibly leading to cytotoxicity. Based on the results shown here, there is a potential of P40 BGMS and AW P40 PGMS for hMSC-based bone repair therapy. However, future work needs to be done in order to limit the delamination of glass surfaces and release of glass fragments/particulates from these MS, as a result of degradation

Syntheses and Characterization of New Nickel Coordination Polymers with 4,4′-Dipyridylsulfide. Dynamic Rearrangements of One-Dimensional Chains Responding to External Stimuli: Temperature Variation and Guest Releases/Re-Inclusions

Crystal structures and dynamic rearrangements of one-dimensional coordination polymers with 4,4′-dipyridylsulfide (dps) have been studied. Reaction of Ni(NO3)2·6H2O with dps in EtOH yielded [Ni(dps)2(NO3)2] ·EtOH (1), which had channels filled with guest EtOH molecules among the four Ni(dps)2 chains. This coordination polymer reversibly transformed the channel structure responding to temperature variations. Immersion of 1 in m-xylene released guest EtOH molecules to yield a guest-free coordination polymer [Ni(dps)2(NO3)2] (2a), which was also obtained by treatment of Ni(NO3)2·6H2O with dps in MeOH. On the other hand, removal of the guest molecules from 1 upon heating at 130 °C under reduced pressure produced a guest-free coordination polymer [Ni(dps)2(NO3)2] (2b). Although the 2a and 2b guest-free coordination polymers have the same formula, they showed differences in the assembled structures of the one-dimensional chains. Exposure of 2b to EtOH vapor reproduced 1, while 2a did not convert to 1 in a similar reaction. Reaction of Ni(NO3)2·6H2O with dps in acetone provided [Ni(dps)(NO3)2(H2O)] ·Me2CO (4) with no channel structure. When MeOH or acetone was used as a reaction solvent, the [Ni(dps)2(NO3)2] · (guest molecule) type coordination polymer, which was observed in 1, was not formed. Nevertheless, the reaction of Ni(NO3)2·6H2O with dps in MeOH/acetone mixed solution produced [Ni(dps)2(NO3)2]·0.5(MeOH·acetone) (5), which has an isostructural Ni-dps framework to 1

The ASTRO-H X-ray Observatory

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

The Quiescent Intracluster Medium in the Core of the Perseus Cluster

Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July