Neutrino Spectroscopy of the Early Phase of Nearby Supernovae

Neutrinos emitted during stellar core collapse up to their trapping phase carry information about the stage from which the Supernova explosion process initiates. The dominant $\nu_e$ emission mechanism is by electron capture on free protons and f-p shell nuclei and the spectrum of these neutrinos is a function of the ambient physical conditions within the core as well as the nuclear equation of state. The number of collapse phase $\nu_e$ which can be detected by Super-Kamioka and Sudbury Neutrino Observatory from a Supernova within 1 kpc, and their generic energy spectra are given.Comment: 9 pages of text and tables plus 2 pages of figures. Accepted for publication in Phys. Rev. Lett. on 11th Jul., 1997. Please e-mail Comments etc. to [email protected]

Massive stars as thermonuclear reactors and their explosions following core collapse

Nuclear reactions transform atomic nuclei inside stars. This is the process of stellar nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars are reviewed. How stars manage to burn their fuel so slowly most of the time are also considered. Stellar thermonuclear reactions involving protons in hydrostatic burning are discussed first. Then I discuss triple alpha reactions in the helium burning stage. Carbon and oxygen survive in red giant stars because of the nuclear structure of oxygen and neon. Further nuclear burning of carbon, neon, oxygen and silicon in quiescent conditions are discussed next. In the subsequent core-collapse phase, neutronization due to electron capture from the top of the Fermi sea in a degenerate core takes place. The expected signal of neutrinos from a nearby supernova is calculated. The supernova often explodes inside a dense circumstellar medium, which is established due to the progenitor star losing its outermost envelope in a stellar wind or mass transfer in a binary system. The nature of the circumstellar medium and the ejecta of the supernova and their dynamics are revealed by observations in the optical, IR, radio, and X-ray bands, and I discuss some of these observations and their interpretations.Comment: To be published in " Principles and Perspectives in Cosmochemistry" Lecture Notes on Kodai School on Synthesis of Elements in Stars; ed. by Aruna Goswami & Eswar Reddy, Springer Verlag, 2009. Contains 21 figure

Role of serum interleukin-6 level on hyperalgesia and spinal mu-opioid receptor expression during the complete Freund's adjuvant-induced chronic inflammation

Background: Interleukin (IL-6) is known to cause pro- and anti-inflammatory effects during different stages of inflammation. The purpose of this study was to elucidate the effects of IL-6 on hyperalgesia, edema and the changes in the spinal mu opioid receptor expression during different stages of complete Freund’s adjuvant (CFA)-induced arthritis (AA) in rats. Materials and Methods: In this study, AA was induced by a single subcutaneous injection of CFA into rats’ hindpaw. The rats with arthritis were divided into four groups, each consisted of three subgroups (n= 6). Anti-IL-6 was administered either daily or weekly during the 21-day study period. Spinal mu-opioid receptor (mOR) expression was detected by Western blotting. Results: Daily treatment with an anti-IL-6 antibody significantly decreased the paw edema in the AA group compared to the control one (P=0.001), but daily and weekly anti-IL-6 administrations significantly increased the hyperalgesia in the antibody-treated group on the 14th and 21st days post-treatment (P=0.001, P=0.01, respectively). The administration of IL-6 antibody not only increased hyperalgesia in a time-dependent manner, but also caused a significant reduction in the spinal mOR expression on the 14th and 21st days post-CFA injection (P=0.01, P=0.001, respectively). Conclusion: Results can indicate the importance of a time-dependent relationship between the serum IL-6 level and hyperalgesia during the AA. Moreover, the results suggest that the stages of inflammation in AA must be considered for anti-hyperalgesic and anti-inflammatory interventions via anti-IL-6 antibody treatment

Effect of methanol extract of Althaea root on contractile function of rat's tracheal smooth muscle

Background: The sudden involuntary muscular contractions of the air ways is a very common disease in human societies. Study on medical plant extracts to affect contractile activity of the tracheal smooth muscle can be useful manner in control of pulmonary obstructive sickness. Objectives: This research was designed to determine the effect of Althaeas' root methanol extract on contractile function of rat tracheal smooth muscle. Methods: In this experimental study, 36 tracheas of a healthy and male of 18 Sprague Dawley rats were dissected in 6 groups. The effect of Althaeas' root methanol extract concentrations (0.2, 0.6, 2.6, 6.6, 14.6, 140.6 μg/ml) and epinephrine (5 μm) in presence and absence of 1μM propranolol under one gram tension based on isometric method was assayed. This assay was recorded in an organ bath containing kerebs-hancelit solution on tracheal smooth muscle contractions by KCl (60 mM) induction. Results: Epinephrine (5 μm) alone and root methanol extract concentrations (0.6-140.6 μg/ml) reduced the tracheal smooth muscle contractions induced by KCl (60 mM) dose-dependently. Propranolol couldn't reduce the antispasmodic effect of root methanol extract concentrations, but it could reduce the antispasmodic effect of Epinephrine on tracheal smooth muscle contractions. Conclusion: Althaeas' root methanol extract inhibited the tracheal smooth muscle of rat contractions dose dependently, but it seems that β-Adrenergic receptors are not engage in this process. Realizing the mechanism of this process can be useful in treatment of pulmonary obstructive disease