Structural effects of phosphate groups on apatite formation in a copolymer modified with Ca2+ in a simulated body fluid

Organic–inorganic composites are novel bone substitutes that can ameliorate the mismatch of Young\u27s moduli between natural bone and implanted ceramics. Phosphate groups contribute to the formation of apatite in a simulated body fluid (SBF) and the adhesion of osteoblast-like cells. Therefore, modification of a polymer with these functional groups is expected to enhance the ability of the organic–inorganic composite to bond with bone. Two phosphate groups have been used, phosphonic acid (–C–PO3H2) and phosphoric acid (–O–PO3H2). However, the effects of structural differences between these phosphate groups have not been clarified. In this study, the apatite formation of copolymers modified with Ca2+ and either –C–PO3H2 or –O–PO3H2 was examined. The mechanism of apatite formation is discussed based on analytical and computational approaches. The copolymers containing –O–PO3H2, but not those containing –C–PO3H2, formed apatite in the SBF, although both released similar amounts of Ca2+ into the SBF. Adsorption of HPO42− from –O–PO3H2 in the SBF following Ca2+ adsorption was confirmed by zeta-potential measurement and X-ray photoelectron spectroscopy. The measurement of the complex formation constant revealed that the –O–PO32−⋯Ca2+ complex was thermodynamically unstable enough to convert into CaHPO4, which was not the case with –C–PO32−⋯Ca2+. The formation of CaHPO4-based clusters was found to be a key factor for apatite nucleation. In conclusion, this study revealed that modification with –O–PO3H2 was more effective for enhancing apatite formation compared with –C–PO3H2

Hybrid mode atomic force microscopy of phase modulation and frequency modulation

This is a pre-copyedited, author-produced version of an article accepted for publication in Microscopy following peer review. The version of record Yamamoto T., Miyazaki M., Nomura H., et al. Hybrid mode atomic force microscopy of phase modulation and frequency modulation. 72(3), 236-242 1 June 2023 is available online at: https://doi.org/10.1093/jmicro/dfac057.We propose hybrid phase modulation (PM)/frequency modulation (FM) atomic force microscopy (AFM) to increase the imaging speed of AFM in high-Q environments. We derive the relationship between the phase shift, the frequency shift and the tip-sample interaction force from the equation of motion for the cantilever in high-Q environments. The tip-sample conservative force is approximately given by the sum of the conservative force with respect to the phase shift in the PM mode and that with respect to the frequency shift in the FM mode. We preliminarily demonstrate that the hybrid PM/FM-AFM is a new and very promising AFM operation mode that can increase imaging speed

Non-linear rheology of layered systems - a phase model approach

We study non-linear rheology of a simple theoretical model developed to mimic layered systems such as lamellar structures under shear. In the present work we study a 2-dimensional version of the model which exhibits a Kosterlitz-Thouless transition in equilibrium at a critical temperature Tc. While the system behaves as Newtonain fluid at high temperatures T > Tc, it exhibits shear thinning at low temperatures T < Tc. The non-linear rheology in the present model is understood as due to motions of edge dislocations and resembles the non-linear transport phenomena in superconductors by vortex motions.Comment: 10 pages, 5 figures, contribution to the conference proceeding of International Conference on Science of Friction, Irago Aichi, Japan Sept 9-13 200

Paraimmunobiotic bifidobacteria modulate the expression patterns of peptidoglycan recognition proteins in porcine intestinal epitheliocytes and antigen presenting ells

Peptidoglycan recognition proteins (PGLYRPs) are a family of pattern recognition receptors (PRRs) that are able to induce innate immune responses through their binding to peptidoglycan (PGN), lipopolysaccharide, or lipoteichoic acid, or by interacting with other PRR-ligands. Recently, progress has been made in understanding the immunobiology of PGLYRPs in human and mice, however, their functions in livestock animals have been less explored. In this study, we characterized the expression patterns of PGLYRPs in porcine intestinal epithelial (PIE) cells and antigen-presenting cells (APCs) and their modulation by the interactions of host cells with PRR-ligands and non-viable immunomodulatory probiotics referred to as paraimmunobiotics. We demonstrated that PGLYRP-1, -2, -3, and -4 are expressed in PIE cells and APCs from Peyer?s patches, being PGLYPR-3 and -4 levels higher than PGLYRP-1 and -2. We also showed that PGLYRPs expression in APCs and PIE cells can be modulated by different PRR agonists. By using knockdown PIE cells for TLR2, TLR4, NOD1, and NOD2, or the four PGLYRPs, we demonstrated that PGLYRPs expressions would be required for activation and functioning of TLR2, TLR4, NOD1, and NOD2 in porcine epitheliocytes, but PGLYRPs activation would be independent of those PRR expressions. Importantly, we reported for the first time that PGLYRPs expression can be differentially modulated by paraimmunobiotic bifidobacteria in a strain-dependent manner. These results provide evidence for the use of paraimmunobiotic bifidobacteria as an alternative for the improvement of resistance to intestinal infections or as therapeutic tools for the reduction of the severity of inflammatory damage in diseases in which a role of PGLYRPs-microbe interaction has been demonstrated.Fil: Iida, Hikaru. Tohoku University; JapónFil: Tohno, Masanori. National Agriculture and Food Research Organization. Central Region Agricultural Research Centre; JapónFil: Islam, Md. Aminul. Tohoku University; Japón. Agricultural University. Faculty of Veterinary Science. Department of Medicine; BangladeshFil: Sato, Nana. Tohoku University; JapónFil: Kobayashi, Hisakazu. Tohoku University; JapónFil: Albarracín, Leonardo Miguel. Tohoku University; Japón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Humayun Kober, AKM. Tohoku University; JapónFil: Ikeda-Ohtsubo, Wakako. Tohoku University; JapónFil: Suda, Yoshihito. Miyagi University. Department of Food, Agriculture and Environment; JapónFil: Aso, Hisashi. Tohoku University; JapónFil: Nochi, Tomonori. Tohoku University; JapónFil: Miyazaki, Ayako. National Institute of Animal Health. Viral Diseases and Epidemiology Research Division; JapónFil: Uenishi, Hirohide. National Agriculture And Food Research Organization; JapónFil: Iwabuchi, Noriyuki. Morinaga Milk Industry Co., Ltd.; JapónFil: Xiao, Jin-zhong. Morinaga Milk Industry Co., Ltd.; JapónFil: Villena, Julio Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Tohoku University; JapónFil: Kitazawa, Haruki. Tohoku University; Japó

Central nervous system post-transplant lymphoproliferative disorder after allogeneic hematopoietic stem cell transplantation: The Nagasaki transplant group experience

A 17-year-old male received allogeneic transplantation for acute lymphoblastic leukemia, and presented with generalized seizures due to a solitary brain lesion with massive necrosis on day +621. Epstein?Barr virus (EBV) DNA copies were below the cut-off value in plasma. Stereotactic biopsy of the cerebral lesion confirmed the diagnosis of post-transplant lymphoproliferative disorder (PTLD) with large atypical cells positive for CD20 and EBER.In order to diagnose primary central nervous system PTLD, the biopsy should be applied as early as possible when brain lesion with necrosis develops in post-transplant patients regardless of EBV-DNA in plasma

Candidate Brown-dwarf Microlensing Events with Very Short Timescales and Small Angular Einstein Radii

Short-timescale microlensing events are likely to be produced by substellar brown dwarfs (BDs), but it is difficult to securely identify BD lenses based on only event timescales t_E because short-timescale events can also be produced by stellar lenses with high relative lens-source proper motions. In this paper, we report three strong candidate BD-lens events found from the search for lensing events not only with short timescales (t_E ≲ 6 days) but also with very small angular Einstein radii (θ_E ≲ 0.05 mas) among the events that have been found in the 2016–2019 observing seasons. These events include MOA-2017-BLG-147, MOA-2017-BLG-241, and MOA-2019-BLG-256, in which the first two events are produced by single lenses and the last event is produced by a binary lens. From the Monte Carlo simulations of Galactic events conducted with the combined t_E and θ_E constraint, it is estimated that the lens masses of the individual events are 0.051^(+0.100)_(−0.027) M⊙, 0.044^(+0.090)_(−0.023) M⊙, and 0.046^(+0.067)_(−0.023) M⊙/0.038^(+0.056)_(−0.019) M⊙ and the probability of the lens mass smaller than the lower limit of stars is ~80% for all events. We point out that routine lens mass measurements of short-timescale lensing events require survey-mode space-based observations

A Gas Giant Planet in the OGLE-2006-BLG-284L Stellar Binary System

We present the analysis of microlensing event OGLE-2006-BLG-284, which has a lens system that consists of two stars and a gas giant planet with a mass ratio of $q_p = (1.26\pm 0.19) \times 10^{-3}$ to the primary. The mass ratio of the two stars is $q_s = 0.289\pm 0.011$, and their projected separation is $s_s = 2.1\pm 0.7\,$AU, while the projected separation of the planet from the primary is $s_p = 2.2\pm 0.8\,$AU. For this lens system to have stable orbits, the three-dimensional separation of either the primary and secondary stars or the planet and primary star must be much larger than that these projected separations. Since we do not know which is the case, the system could include either a circumbinary or a circumstellar planet. Because there is no measurement of the microlensing parallax effect or lens system brightness, we can only make a rough Bayesian estimate of the lens system masses and brightness. We find host star and planet masses of $M_{L1} = 0.35^{+0.30}_{-0.20}\,M_\odot$, $M_{L2} = 0.10^{+0.09}_{-0.06}\,M_\odot$, and $m_p = 144^{+126}_{-82}\,M_\oplus$, and the $K$-band magnitude of the combined brightness of the host stars is $K_L = 19.7^{+0.7}_{-1.0}$. The separation between the lens and source system will be $\sim 90\,$mas in mid-2020, so it should be possible to detect the host system with follow-up adaptive optics or Hubble Space Telescope observations

A Gas Giant Planet in the OGLE-2006-BLG-284L Stellar Binary System

We present the analysis of microlensing event OGLE-2006-BLG-284, which has a lens system that consists of two stars and a gas giant planet with a mass ratio of q_p = (1.26 ± 0.19) × 10⁻³ to the primary. The mass ratio of the two stars is q_s = 0.289 ± 0.011, and their projected separation is s_s = 2.1 ± 0.7 au, while the projected separation of the planet from the primary is s_p = 2.2 ± 0.8 au. For this lens system to have stable orbits, the three-dimensional separation of either the primary and secondary stars or the planet and primary star must be much larger than the projected separations. Since we do not know which is the case, the system could include either a circumbinary or a circumstellar planet. Because there is no measurement of the microlensing parallax effect or lens system brightness, we can only make a rough Bayesian estimate of the lens system masses and brightness. We find host star and planet masses of, M_(L1) = 0.35^(+0.30)_(−0.20) M⊙, M_(L2) = 0.10^(+0.09)_(−0.06) M⊙, and m_p = 144^(+126)_(−82) M⊕, and the K-band magnitude of the combined brightness of the host stars is K_L = 19.7^(+0.7)_(−1.0). The separation between the lens and source system will be ~90 mas in mid-2020, so it should be possible to detect the host system with follow-up adaptive optics or Hubble Space Telescope observations