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•A water-based ferrofluid was irradiated with photons and electrons.•The dose was that usually involved in radiation therapy of human subjects (50 Gy).•Electron irradiation induced ...minor change in the colloidal stability of ferrofluid.•Magnetic heating of ferrofluid at 100 kHz is not affected by irradiation.•Magnetic hyperthermia can be applied in the same time period as radiation therapy.
The paper reports on the effect of therapeutic-like irradiation of a water based magnetic fluid with magnetite particles double-surfacted with oleic acid on its magnetic heating characteristics. To assess the effect of irradiation, a quantity of the initial sample was retained as the reference sample. The other part of the ferrofluid was irradiated with a photon beam (with the energy of 10 MeV and the dose of 50 Gy) and with an electron beam (of the energy of 9 MeV and the dose of 50 Gy).
The frequency dependence of the complex magnetic permeability, μ(ω) = μ′(ω)-i μ″(ω), was affected only in the case of the electron irradiated sample and over the approximate range of 10–100 kHz.
The dynamic light scattering investigation revealed a small increase of the average of the size of light scattering entities and of the polydispersity index of the sample irradiated with electrons compared to the reference sample.
Magnetic heating experiments, performed at the frequency of 100 kHz and with various amplitudes of magnetic field, H, (of 25, 50, 75 and 100 Oe) did not reveal significant difference in the heating rate values of the reference sample and of the irradiated samples. Therefore, magnetic hyperthermia can be involved in the therapy plan, in the same period of time as the radiation therapy, provided at the frequency of the alternating magnetic field larger than the frequency corresponding to the Brownian relaxation peak.
A
bstract
We describe a proposal to add a set of very forward detectors to the CMS experiment for the high-luminosity era of the Large Hadron Collider to search for beyond the standard model ...long-lived particles, such as dark photons, heavy neutral leptons, axion-like particles, and dark Higgs bosons. The proposed subsystem is called
FACET
for
F
orward-
A
perture
C
MS
E
x
T
ension, and will be sensitive to any particles that can penetrate at least 50 m of magnetized iron and decay in an 18 m long, 1 m diameter vacuum pipe. The decay products will be measured in detectors using identical technology to the planned CMS Phase-2 upgrade.
In this work, alkali and oxidative treatments were employed to obtain flax fibers with different content of hemicelluloses and lignin, in order to study the influence of chemical composition on ...structure and sorption properties of flax fibers. The flax fibers were characterized using FTIR spectroscopy and FESEM microscopy, and by determination of chemical composition, carboxyl group content, electrokinetic and sorption properties. Adsorption of silver ions was used to evaluate flax fiber sorption properties, but also to obtain antimicrobial fibers whose antimicrobial activity was tested against Gram-negative bacteria
Escherichia coli
, Gram-positive bacteria
Staphylococcus aureus
and fungi
Candida albicans
. The progressive removal of hemicelluloses or lignin influenced the sorption properties through the increased liberation of elementary fibers and accessibility of functional surface groups of flax fibers. Removal of hemicelluloses led to increase of iodine sorption without significant change in functional groups content and electrokinetic properties. On the other hand, lignin removal led to an increase of functional groups content, namely carboxyl groups, which in turn influenced better moisture and silver ions sorption. Flax fibers with incorporated silver exhibit fair antimicrobial activity against Gram (−)
E. coli
, Gram (+)
S. aureus
and fungi
C. albicans
.
Neutrinos are abundantly produced in the LHC. Flavour composition and energy reach of the neutrino flux from proton-proton collisions depend on the pseudorapidity . At large , energies can exceed the ...TeV, with a sizeable contribution of the τ flavour. A dedicated detector could intercept this intense neutrino flux in the forward direction, and measure the interaction cross section on nucleons in the unexplored energy range from a few hundred GeV to a few TeV. The high energies of neutrinos result in a larger N interaction cross section, and the detector size can be relatively small. Machine backgrounds vary rapidly while moving along and away from the beam line. Four locations were considered as hosts for a neutrino detector: the CMS quadrupole region (25 m from CMS Interaction Point (IP)), UJ53 and UJ57 (90 and 120 m from CMS IP), RR53 and RR57 (240 m from CMS IP), TI18 (480 m from ATLAS IP). The potential sites are studied on the basis of (a) expectations for neutrino interaction rates, flavour composition and energy spectrum, (b) predicted backgrounds and in situ measurements, performed with a nuclear emulsion detector and radiation monitors. TI18 emerges as the most favourable location. Already with 150 fb−1 expected in LHC Run3, a small detector in TI18 could measure, for the first time and with good precision, the high-energy N cross section for all neutrino flavours.
Purpose: This study evaluated the cytotoxic effects of polymethyl methacrylate resin extracts on rat macrophage viability in in vitro conditions.Methods: Prepared test specimens were immersed in 5 mL ...of artificial saliva and incubated for 24, 48, and 72 h at 37°C. The cytotoxicity of the obtained solutions of extracted resins, used as a stock solution (100%) and diluted with Roswell Park Memorial Institute (RPMI) medium to obtain the working solutions (50, 40, 30, 20, 10, and 5%), was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Results: No dose-dependent toxic activity in macrophage culture was detected for the three types of extracts obtained after 24, 48, and 72 h of material extraction. The shortest extraction of material was found to be completely non-toxic, and the 20% concentration of this extract obtained caused a significant increase in cell ability to metabolize MTT. Extracts obtained after 72 h of extraction showed the highest cytotoxic potential of 50%, 40% and 30%, and extracts obtained after 48 and 72 h of extraction at concentrations of 5% and 10% had a proliferative effect on the macrophage cell line.Conclusion: This study demonstrated that the highest cytotoxic effect was observed in cells exposed to the highest concentrations (50, 40, and 30%) of the extracts that were extracted for 72 h.
We discuss an experiment to investigate neutrino physics at the LHC, with emphasis on tau flavour. As described in our previous paper Beni et al (2019 J. Phys. G: Nucl. Part. Phys. 46 115008), the ...detector can be installed in the decommissioned TI18 tunnel, ≈480 m downstream the ATLAS cavern, after the first bending dipoles of the LHC arc. The detector intercepts the intense neutrino flux, generated by the LHC beams colliding in IP1, at large pseudorapidity η, where neutrino energies can exceed a TeV. This paper focuses on exploring the neutrino pseudorapity versus energy phase space available in TI18 in order to optimize the detector location and acceptance for neutrinos originating at the pp interaction point, in contrast to neutrinos from pion and kaon decays. The studies are based on the comparison of simulated pp collisions at s= 13 TeV: PYTHIA events of heavy quark (c and b) production, compared to DPMJET minimum bias events (including charm) with produced particles traced through realistic LHC optics with FLUKA. Our studies favour a configuration where the detector is positioned off the beam axis, slightly above the ideal prolongation of the LHC beam from the straight section, covering 7.4 < η < 9.2. In this configuration, the flux at high energies (0.5-1.5 TeV and beyond) is found to be dominated by neutrinos originating directly from IP1, mostly from charm decays, of which ≈50% are electron neutrinos and ≈5% are tau neutrinos. The contribution of pion and kaon decays to the muon neutrino flux is found small at those high energies. With 150 fb−1 of delivered LHC luminosity in Run 3 the experiment can record a few thousand very high energy neutrino charged current (CC) interactions and over 50 tau neutrino CC events. These events provide useful information in view of a high statistics experiment at HL-LHC. The electron and muon neutrino samples can extend the knowledge of the charm PDF to a new region of x, which is dominated by theory uncertainties. The tau neutrino sample can provide first experience on reconstruction of tau neutrino events in a very boosted regime.
Abstract Human papillomavirus 8 (HPV8) is involved in skin cancer development in epidermodysplasia verruciformis patients. Transgenic mice expressing HPV8 early genes (HPV8-CER) developed papillomas, ...dysplasias and squamous cell carcinomas. UVA/B-irradiation and mechanical wounding of HPV8-CER mouse skin led to prompt papilloma induction in about 3 weeks. The aim of this study was to analyze the kinetics and level of transgene expression in response to skin irritations. Transgene expression was already enhanced 1 to 2 days after UVA/B-irradiation or tape-stripping and maintained during papilloma development. The enhanced transgene expression could be assigned to UVB and not to UVA. Papilloma development was thus always paralleled by an increased transgene expression irrespective of the type of skin irritation. A knock-down of E6 mRNA by tattooing HPV8-E6-specific siRNA led to a delay and a lower incidence of papilloma development. This indicates that the early increase of viral oncogene expression is crucial for induction of papillomatosis.
An effective instructional approach in elementary mathematics education has a significant role in the understanding of mathematical concepts and overall student achievement. We point out the ...characteristics, significance and effects that may be achieved in mathematics education through the application of project-based learning. The aim of the study was to examine the effects of project-based learning on student achievement in lower elementary mathematics education and examine whether the project-based model was equally acceptable to students with different marks. We arranged quasi-experimental research instruction (experiment with parallel groups), on a sample (N = 147) in order to examine whether an instructional approach based on the principles of project-based work would achieve better effects of learning and student achievement compared to the usual way of learning implemented in mathematics education. Results of the final measurements show that students in the experimental group, who worked according to the model of project-based work, achieved better compared to students who worked in the usual way. With this study we have shown that project-based instruction has significant effects on student achievement in lower elementary mathematics education, and that it can undoubtedly contribute to the methodological empowerment of teachers in their teaching practice.
Flax fibers were modified with NaOH and NaClO2 under different conditions in order to not only clarify the effects of hemicelluloses and lignin removal on the morphology and properties of flax ...fibers, but also to improve the fiber quality. The quality of flax fibers was characterized in terms of chemical composition, fineness, whiteness, and mechanical and sorption properties. Both treatments, alkali treatment leading to hemicelluloses removal (up to 72 % of the hemicelluloses removed) and chlorite treatment leading to lignin removal (up to 96 % of the lignin removed), induce a modification of the morphology and properties of flax fibers. For 5 % NaOH treatments, as well as all NaClO2 treatments, an increase in the crystallinity was observed, while for higher NaOH concentrations, the mercerization phenomenon induced a slight decrease in the crystallinity. Modification with NaClO2 resulted in fiber fibrillation while modification with NaOH at boiling temperature resulted in smoother fiber surfaces. Both treatments cause a decrease in tensile strength and water retention values, with the maximal decrease obtained with NaOH treatment at boiling temperature. Chlorite treatment resulted in finer fibers having a higher whiteness index compare to the alkali-modified fibers.
The frequency dependence of the complex magnetic susceptibility, χ(ω) = χ′(ω) − i χ″(ω), of a water-based magnetic fluid with magnetite particles, over the frequency range 500 kHz to 2 MHz and at ...three different temperatures of 30 °C, 40 °C and 50 °C are presented. Based on these experimental measurements, the dependence on frequency, f = (ω/2π) Hz, of the heating rate, ΔT/Δt, of the ferrofluid has been evaluated at these stated temperatures and alternating magnetic field of different amplitudes, Ho = 200 A/m, 400 A/m, 600 A/m, 800 A/m and 1 kA/m.
The results show that the preheating of the ferrofluid sample at the desired operating temperature has the advantage of using lower levels of H0 during over a shorter time period, as opposed to the case of an unheated sample. This concept of preheating a sample, has major significance for the treatment of cancer by magnetic hyperthermia in that the patient is subjected to lower values of H0, over the time period of the treatment.
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