Evolution of Supernova Remnants Expanding out of the Dense Circumstellar Matter into the Rarefied Interstellar Medium

We carry out 3D-hydrodynamical calculations for the interaction of expanding supernova ejecta with the dense circumstellar matter (CSM) and the rarefied interstellar medium (ISM) outside. The CSM is composed of the stellar wind matter from the progenitor in its pre-supernova phase, and assumed to be axially symmetric: more matter around the equator than in the polar direction driven by rotation of the progenitor. Because of high density of the CSM, the ionization state of the shock-heated ejecta quickly becomes equilibrium with the electron temperature. When the blast wave breaks out of the CSM into the rarefied ISM, the shocked ejecta cools rapidly due to adiabatic expansion, and hence an over-ionized/recombining plasma would be left. The ejecta is reheated by the second reverse shock due to the interaction with the ISM. We calculate the emission measure of the supernova remnant (SNR) along the line of sight, and find that the over-ionized plasma appears to be bar-like with wings in the edge-on (equatorial view), while shell-like in the face-on (polar view) geometry with respect to the rotation axis. The hot gas heated by the blast wave exists in the outermost region of the SNR with a nearly complete shell, but the X-rays therefrom are too faint to be observable. Thus, depending on the viewing angle, the SNR of the over-ionized plasma would exhibit center-filled morphology in X-rays, like W49B, a mixed-morphology SNR. The bar-like structure is swept out by the second reverse shock and disappears eventually, and then the SNR becomes shell-like in both the equatorial and polar views in the later phase of the evolution.Comment: 8 pages, 9 figures, accepted for publication in PAS

Dynamical Evolution and High-Energy Radiation of Mixed-Morphology Supernova Remnants

Evolution of a supernova remnant (SNR) without an active neutron star is basically described by probation of shock waves. The shock waves accelerate charged particles. The particles accelerated to GeV radiate synchrotron radio emission, which appears to be shelllike morphology. The shock waves heat matter up to keV, and heated-electrons ionize ions. Compared with a time-scale of shock-heating of electrons by the shock, a time-scale of ionization of ions by electron collisions in the shock down stream region is longer. Hence an ionization state of SNR plasma is thought to be under-ionized state in which the ionization temperature is lower than the electron temperature, or collisional ionization equilibrium state at late time. In fact, X-ray spectra of many SNRs are explained by such plasma state model. SNRs that exhibit shell-like morphology in thermal X-ray as well as radio are categorized into shell-like SNRs. In contrast to shell-like SNRs, some SNRs exhibit shell-like radio but center-filled thermal X-ray morphology. Such SNRs are categorized into mixed-morphology SNRs (MM SNRs). Many MM SNRs interact with molecular clouds, suggested by OH maser and near infrared observations, and hence are thought to be remnants of core-collapse supernova of massive stars. Interestingly, recombination radiation X-rays, which are evidence that X-ray emitting plasmas are over-ionized states in which the ionization temperature is higher than the electron temperature, are detected from six MM SNRs. The center-filled X-rays with recombination radiation can not be explained by a picture of shock-wave propagation that explains the X-rays of shell-like SNRs. As well as X-rays, MM SNRs are characteristic in γ-ray emission. Several MM SNRs and shell-like SNRs are detected in the GeV γ-ray band by Fermi. The 1 − 100 GeV γ-ray luminosities of MM SNRs are ～ 10^ − 10^ erg s^, which are systematically higher than those of shell-like SNRs of ～ 10^ − 10^ erg s^. Such high luminosities may be caused by π^0-decay γ-rays enhanced by the interactions with molecular clouds. The γ-ray spectra of SNRs are fitted to broken power-laws with break energies of 1 − 100 GeV above which the spectra become steep. If the progenitors of MM SNRs are massive stars, their X-ray characters may caused by progenitors and/or their environment. One possibility of the origin of over-ionized state is rarefaction: when the blast wave breaks out of the dense circumstellar matter, consists of stellar wind matter blown out by the progenitor, into rarefied interstellar medium, electrons rapidly cool by adiabatic expansion, leaving a high ionization state (Itoh and Masai 1989). Such SNR evolution is investigated only by Itoh and Masai (1989), and whether the evolution results in other characters of MM SNRs is not clear. The work of Itoh and Masai (1989) is spherically-symmetric calculation. We extent their work to three dimensional non-symmetric calculation. In realistic stellar wind, more matter is in the equatorial plane by rotation, like observed around B[e] stars. Assuming such distribution of stellar wind matter, we carry out numerical hydrodynamic calculation of adiabatic gas. As a result of the calculation, we find that shocked ejecta and stellar wind matter become over-ionized states due to rarefaction after the break-out when the anisotropies of stellar wind matter are considered. The shocked ejecta contribute X-ray emission dominantly, because the density of the shocked ejecta is higher that those of the shocked stellar wind matter and ISM. The X-ray emission measure appears to be an irregular shape depending on viewing angle in early times after the break-out because of the anisotropies of stellar wind matter., e.g., bar-like structure with wings at either end in equatorial view. Since the shocked ejecta are located far inside the blast wave, the distribution of emission measure is inside the blast wave. Using the results of hydrodynamic calculations, we investigate synchrotron radio and bremsstrahlung, inverse-Compton scattering, and π^0-decay γ-ray emissions from blast-shocked ISM shell. Just after the break-out, the blast wave is accelerated to have a high velocity, which is favor for magnetic field amplification near the shock. We take such amplification into calculation. As a result, the radio flux at 1 GHz is tens of Jy, which is comparable to typical observed value of MM SNRs. From the above results of radio and X-rays, we find that the SNR after the break-out exhibit radio shell and center-filled recombination radiation X-ray morphology, as observed in MM SNRs. The γ-ray luminosity is dominated by inverse-Compton scattering because of low density. The total γ-ray luminosity, including bremsstrahlung and π^0-decay, is on the order of 10^ erg s^, which is lower than the typical value of MM SNRs of 10^ − 10^ erg s^. However, if e.g., 10% of accelerated protons interact with some matter of density of ～ 100 cm^, the π^0-decay γ-ray luminosity would be enhanced to be comparable with the typical value. In order to verify the SNR model considered in the present thesis, we investigate observations of X-ray fluxes and γ-ray spectra, referring to radio, of MM SNRs comparing with shell-like SNRs. The 2.1-10 keV X-rays to 1 GHz radio flux ratios of MM SNRs are lower than those of shell-like SNRs at the same 1 GHz surface brightness. This can be explain by lower emissivity of plasma in the over-ionized state than other ionization states.首都大学東京, 2014-03-25, 博士（理学）, 甲第407号首都大学東

Ocular infestation by a juvenile leech, Myxobdella sinanensis in Japan

[Purpose] The case of ocular infestation by a leech is rare. We reported that Myxobdella sinanensis infests conjunctiva. [Observations] A 5-year-old girl presented with blood clots in the inner corner of the left eye, and a history bloody eye discharge and bloody tears for 5 days. She was prescribed 0.5% levofloxacin ophthalmic drops for conjunctival damage. However, her parent watched a worm moving in her conjunctiva while taking a bath. She presented again the same day, and a worm was found in the left eye of the lower conjunctival fornix and was adsorbed to the inner corner. We removed a worm under eye drop anesthesia, the next day the patient had no symptoms. We captured the worm, and it was identified morphologically and genetically as Myxobdella sinanensis. This was the first case reported of Myxobdella sinanensis be infestation in a human. [Conclusions and Importance] The ecological trait of Myxobdella sinanensis still did not remain clear, so this case report was helpful to find out a life cycle of Myxobdella sinanensis. As the outdoor population continues to increase, the cases of human parasites such as leech are expected to increase. When a patient with bloody eye discharge and bloody tears presents, we should carefully examine the conjunctiva and ocular surfaces, and interview recent history of exposure to stream water

Construction of microbial platform for an energy-requiring bioprocess: practical 2′-deoxyribonucleoside production involving a C−C coupling reaction with high energy substrates

BACKGROUND: Reproduction and sustainability are important for future society, and bioprocesses are one technology that can be used to realize these concepts. However, there is still limited variation in bioprocesses and there are several challenges, especially in the operation of energy-requiring bioprocesses. As an example of a microbial platform for an energy-requiring bioprocess, we established a process that efficiently and enzymatically synthesizes 2′-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase. This method consists of the coupling reactions of the reversible nucleoside degradation pathway and energy generation through the yeast glycolytic pathway. RESULTS: Using E. coli that co-express deoxyriboaldolase and phosphopentomutase, a high amount of 2′-deoxyribonucleoside was produced with efficient energy transfer under phosphate-limiting reaction conditions. Keeping the nucleobase concentration low and the mixture at a low reaction temperature increased the yield of 2′-deoxyribonucleoside relative to the amount of added nucleobase, indicating that energy was efficiently generated from glucose via the yeast glycolytic pathway under these reaction conditions. Using a one-pot reaction in which small amounts of adenine, adenosine, and acetone-dried yeast were fed into the reaction, 75 mM of 2′-deoxyinosine, the deaminated product of 2′-deoxyadenosine, was produced from glucose (600 mM), acetaldehyde (250 mM), adenine (70 mM), and adenosine (20 mM) with a high yield relative to the total base moiety input (83%). Moreover, a variety of natural dNSs were further synthesized by introducing a base-exchange reaction into the process. CONCLUSION: A critical common issue in energy-requiring bioprocess is fine control of phosphate concentration. We tried to resolve this problem, and provide the convenient recipe for establishment of energy-requiring bioprocesses. It is anticipated that the commercial demand for dNSs, which are primary metabolites that accumulate at very low levels in the metabolic pool, will grow. The development of an efficient production method for these compounds will have a great impact in both fields of applied microbiology and industry and will also serve as a good example of a microbial platform for energy-requiring bioprocesses

Prolyl Isomerase Pin1 Directly Regulates Calcium/Calmodulin-Dependent Protein Kinase II Activity in Mouse Brains

Calcium/calmodulin-dependent protein kinase II (CaMKII) is abundant in the brain and functions as a mediator of calcium signaling. We found that the relative activity of CaMKII was significantly lower in the WT mouse brains than in the Pin1-/- mouse brains. Pin1 binds to phosphorylated CaMKII and weakens its activity. For this reason, the phosphorylation level of tau in the presence of Pin1 is lower than that in the absence of Pin1, and microtubule polymerization is not downregulated by CaMKII when Pin1 is present. These results suggest a novel mechanism of action of Pin1 to prevent neurodegeneration

Akt2 phosphorylates Synip to regulate docking and fusion of GLUT4-containing vesicles

We have identified an unusual potential dual Akt/protein kinase B consensus phosphorylation motif in the protein Synip (RxKxRS97xS99). Surprisingly, serine 97 is not appreciably phosphorylated, whereas serine 99 is only a specific substrate for Akt2 but not Akt1 or Akt3. Although wild-type Synip (WT-Synip) undergoes an insulin-stimulated dissociation from Syntaxin4, the Synip serine 99 to phenylalanine mutant (S99F-Synip) is resistant to Akt2 phosphorylation and fails to display insulin-stimulated Syntaxin4 dissociation. Furthermore, overexpression of WT-Synip in 3T3L1 adipocytes had no effect on insulin-stimulated recruitment of glucose transporter 4 (GLUT4) to the plasma membrane, whereas overexpression of S99F-Synip functioned in a dominant-interfering manner by preventing insulin-stimulated GLUT4 recruitment and plasma membrane fusion. These data demonstrate that insulin activation of Akt2 specifically regulates the docking/fusion step of GLUT4-containing vesicles at the plasma membrane through the regulation of Synip phosphorylation and Synip–Syntaxin4 interaction