61 research outputs found
Genotoxicity of DrinkingWater Disinfectants in Plant Bioassays
The genotoxicity of two widely used drinking
water disinfectants, sodium hypochlorite (NaClO)
and chlorine dioxide (ClO2), and a new disinfectant,
peracetic acid (PAA, CH3-CO-COOH), was
evaluated in three short-term plant tests: (1) induction
of anaphase chromosome aberrations in the
root cells of Allium cepa, (2) micronucleus induction
in the root cells of Vicia faba, and (3) micronucleus
induction in Tradescantia pollen cells. The
study was carried out in the laboratory by directly
exposing the plants to several concentrations of
the disinfectants in redistilled water at unadjusted
(acid) and adjusted (neutral) pHs. Both 0.1 and
0.2 mg/l NaClO induced chromosome aberrations
in the Allium cepa test at acid pH, but concentrations
up to 0.5 mg/l of all the disinfectants
were negative at neutral pH. Concentrations ranging
from 0.1 to 0.5 mg/l NaClO, ClO2, and PAA
induced micronuclei in Vicia faba at acid pH,
while 1–2 mg/l NaClO and ClO2 and 0.5–2
mg/l PAA gave positive responses at neutral pH.
Most of concentrations of ClO2 produced positive
responses in the Tradescantia micronucleus test. In
general, the highest levels of genotoxicity were
observed under acid conditions; at acid pH,
significant effects were induced by low concentrations
of ClO2 and PAA. Since the test concentrations
of disinfectants are typical of those
encountered in the biocidal treatment of tap
water and similar concentrations are consumed
daily by a large number of people, the genotoxicity
of these compounds may constitute a significant
public health concern
Measurement of the 58Ni(α, γ) 62Zn reaction and its astrophysical impact
Funding Details: PHY 08-22648, NSF, National Science Foundation; PHY 0969058, NSF, National Science Foundation; PHY 1102511, NSF, National Science FoundationCross section measurements of the 58Ni(α,γ)62Zn reaction were performed in the energy range Eα=5.5to9.5 MeV at the Nuclear Science Laboratory of the University of Notre Dame, using the NSCL Summing NaI(Tl) detector and the γ-summing technique. The measurements are compared to predictions in the statistical Hauser-Feshbach model of nuclear reactions using the SMARAGD code. It is found that the energy dependence of the cross section is reproduced well but the absolute value is overestimated by the prediction. This can be remedied by rescaling the α width by a factor of 0.45. Stellar reactivities were calculated with the rescaled α width and their impact on nucleosynthesis in type Ia supernovae has been studied. It is found that the resulting abundances change by up to 5% when using the new reactivities. © 2014 American Physical Society.Peer reviewe
Quenching Measurements and Modeling of a Boron-Loaded Organic Liquid Scintillator
Organic liquid scintillators are used in a wide variety of applications in experimental nuclear and particle physics. Boron-loaded scintillators are particularly useful for detecting neutron captures, due to the high thermal neutron capture cross section of 10B. These scintillators are commonly used in neutron detectors, including the DarkSide-50 neutron veto, where the neutron may produce a signal when it scatters off protons in the scintillator or when it captures on 10B. Reconstructing the energy of these recoils is complicated by scintillation quenching. Understanding how nuclear recoils are quenched in these scintillators is an important and difficult problem. In this article, we present a set of measurements of neutron-induced proton recoils in a boron-loaded organic liquid scintillator at recoil energies ranging from 57–467 keV, and we compare these measurements to predictions from different quenching models. We find that a modified Birks’ model whose denominator is quadratic in dE/dx best describes the measurements, with χ 2 /NDF= 1.6. This result will help model nuclear recoil scintillation in similar detectors and can be used to improve their neutron tagging efficiency
Collectivity of 0\u3csup\u3e+\u3c/sup\u3e States in \u3csup\u3e160\u3c/sup\u3eGd
Excited 0+ states in 160Gd have been examined with the (n,n′γ) reaction at incident neutron energies up to 2.8 MeV. Gamma-ray excitation functions and angular distribution measurements allow the confirmation of the existence of 0+ states at 1379.70 keV and 1558.30 keV, but we reject the assignments of additional previously suggested 0+ candidates. Limits on the level lifetimes of the observed 0+ states permit an evaluation of the collectivity of these states
Nutraceuticals for peripheral vestibular pathology: Properties, usefulness, future perspectives and medico-legal aspects
Vestibular disorders may generate complex signs and symptoms, which may alter pa-tients’ balance and the quality of life. Dizziness and vertigo can strongly affect daily activities and relations. Despite the presence of conventional drugs, maneuvers, and surgery, another interesting therapeutic opportunity is offered by nutraceuticals. These molecules are often used in the treatment of dizziness and vertigo, but the rationale of their application is not always solidly demon-strated by the scientific evidence. Several substances have shown a variable level of efficacy/useful-ness in this field, but there is lack of important evidence for most of them. From a medico-legal point of view, specific information must be provided to the patient regarding the efficacy and possibilities that the use of these preparations can allow. Administering the right nutraceutical to the proper patient is a fundamental clinical skill. Integrating conventional drug treatment with nutraceutical administration seems to be easy, but it may be difficult considering the (in part unexplored) phar-macodynamics and pharmacokinetics of nutraceuticals. The aim of the scientific community should be to elevate nutraceuticals to the same law and technical dignity of conventional drugs
Lifetime Measurements of Low-Spin Negative-Parity Levels in \u3csup\u3e160\u3c/sup\u3eGd
160Gd(n,n′γ) experiments were performed with accelerator-produced monoenergetic neutrons. Excitation functions at neutron energies from 1.5 to 2.8 MeV aided in the placement of γ rays in the level scheme and angular distributions at three neutron energies resulted in the determination of 28 excited-level lifetimes or limits in 160Gd, including the lifetimes of several negative-parity levels attributed to octupole vibrations
Caratteristiche del puerperio e complicanze nel parto vaginale e nel taglio cesareo. Confronto fra la popolazione italiana e straniera nella casistica 2000-2004 del Policlinico “A. Gemelli”
Obiettivo: questo studio prende in esame le caratteristiche di 14.604 donne che hanno partorito presso il nostro Dipartimento nel periodo 2000-2004. Metodi: sono state esaminate le seguenti variabili: etĂ materna, nazionalitĂ , modalitĂ di parto e complicanze nel puerperio. Risultati: sono emerse le seguenti considerazioni: un aumento della
natalità (da 2.874 parti nel 2000 a 2.974 nel 2004), in parte legato alla presenza sempre più cospicua di donne straniere (dal 14% nel 2000 al 20,7% nel 2004), come riflesso del fenomeno di immigrazione, e in parte anche ad una lenta ma costante ripresa di nascite tra le donne italiane. Inoltre, abbiamo osservato un cambiamento delle caratteristiche epidemiologiche della popolazione ostetrica: età materna avanzata, una maggiore consapevolezza e coscienza della gravidanza e del parto, che ha inciso profondamente sull’incidenza del taglio cesareo. Conclusioni: alla luce di tali considerazioni si rende necessaria una rielaborazione dei protocolli di assistenza clinica e strumentale al puerperio, che hanno tentato di rispondere, da un lato, ad una richiesta
di competenze super-specialistiche e, dall’altro, ad un desiderio di “umanizzazione” del percorso nascita.
Dai risultati ottenuti, che denotano un “controllo” delle complicanze infettive, emorragiche e tromboemboliche, possiamo confermare la validità di tali modelli assistenziali, sostenuti anche da un elevato grado di soddisfazione espresso dalle pazienti durante la degenza
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