777 research outputs found
Curcumin-loaded zeolite as anticancer drug carrier: Effect of curcumin adsorption on zeolite structure
In this work we used a combination of different techniques to investigate the adsorption properties of curcumin by zeolite type A for potential use as an anticancer drug carrier. Curcumin is a natural water-insoluble drug that has attracted great attention in recent years due to its potential anticancer effect in suppressing many types of cancers, while showing a synergistic antitumor effect with other anticancer agents. However, curcumin is poorly soluble in aqueous solutions leading to the application of high drug dosage in oral formulations. Zeolites, inorganic crystalline aluminosilicates with porous structure on the nano- and micro-scale and high internal surface area, can be useful as pharmaceutical carrier systems to encapsulate drugs with intrinsic low aqueous solubility and improve their dissolution. Here, we explore the use of zeolite type A for encapsulation of curcumin, and we investigate its surface properties and morphology, before and after loading of the anticancer agent, using scanning electron microscopy (SEM), powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and UV-vis spectroscopy. Results are used to assess the loading efficiency of zeolite type A towards curcumin and its structural stability after loading
Cosmogenic neutrino fluxes under the effect of active-sterile secret interactions
Ultra High Energy cosmogenic neutrinos may represent a unique opportunity to
unveil possible new physics interactions once restricted to the neutrino sector
only. In the present paper we study the observable effects of a secret
active-sterile interactions, mediated by a pseudoscalar, on the expected flux
of cosmogenic neutrinos. The results show that for masses of sterile neutrinos
and pseudoscalars of hundreds MeV, necessary to evade cosmological,
astrophysical and elementary particle constraints, the presence of such new
interactions can significantly change the energy spectrum of cosmogenic
neutrinos at Earth in the energy range from PeV to ZeV. Interestingly, the
distortion of the spectrum results to be detectable at GRAND apparatus if the
scalar mediator mass is around 250 MeV and the UHECRs are dominated by the
proton component. Larger mediator masses or a chemical composition of UHECRs
dominated by heavier nuclei would require much larger cosmic rays apparatus
which might be available in future.Comment: 10 pages, 3 figure
Fiber Bragg Grating sensors for deformation monitoring of GEM foils in HEP detectors
Fiber Bragg Grating (FBG) sensors have been so far mainly used in high energy
physics (HEP) as high precision positioning and re-positioning sensors and as
low cost, easy to mount, radiation hard and low space- consuming temperature
and humidity devices. FBGs are also commonly used for very precise strain
measurements. In this work we present a novel use of FBGs as flatness and
mechanical tensioning sensors applied to the wide Gas Electron Multiplier (GEM)
foils of the GE1/1 chambers of the Compact Muon Solenoid (CMS) experiment at
Large Hadron Collider (LHC) of CERN. A network of FBG sensors has been used to
determine the optimal mechanical tension applied and to characterize the
mechanical stress applied to the foils. The preliminary results of the test
performed on a full size GE1/1 final prototype and possible future developments
will be discussed.Comment: Four pages, seven figures. Presented by Michele Caponero at IWASI
2015, Gallipoli (Italy
Evaluation of HF-radar wave measures in the Gulf of Naples
HF-radar systems are commonly employed for detecting the upper sea currents. Nevertheless, the signal of such systems can be further post-processed for characterizing as well the wave characteristics, though this is a recent application whose reliability has not been yet exhaustively investigated. In this work, we evaluate HF-radar measures of significant wave height, wave mean period and incident direction against the outcomes of two numerical models previously validated. The comparison is developed in the Gulf of Naples (hereinafter GoN), taking advantage of three antennas placed in the locations of Castellamare di Stabia, Portici and Sorrento. First, a wave hindcast defined on a regional scale is employed; then, wave data are down-scaled through a local model defined over a finer resolution (local scale). The agreement between the systems is evaluated through statistical error indexes. Results show good consistency, leaving room for deepening the use of radars for wave data collection
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Gas detectors for elementary particles require F-based gases for optimal performance.
Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or
banned. This work studies properties of potential eco-friendly gas replacements by computing the
physical and chemical parameters relevant for use as detector media, and suggests candidates to be
considered for experimental investigation
HF Radar Measurements of Surface Waves in the Gulf of Naples (Southeastern Tyrrhenian Sea): Comparison With Hindcast Results at Different Scales
HF radar systems wave measurements are evaluated against numerical simulations in the Gulf of Naples (Southeastern Tyrrhenian Sea). Wave measurements are obtained from three CODAR SeaSonde HF radars installed along the coast of the Gulf of Naples. The numerical models employed are WavewatchIII, implemented on a regional scale with a resolution of about 10 km in longitude and latitude in the whole Mediterranean Sea, and SWAN, implemented with a 200 m resolution in the area of interest. Numerical simulations are also validated against experimental data acquired by a buoy installed offshore the Gulf of Naples. The agreement between HF radar measurements and model hindcasts is evaluated through the estimate of statistical error indices for the main wave characteristics (significant wave height, mean period, and mean direction). The consistency between wave parameters retrieved by HF radars and hindcasted by the models opens the way to future integration of the two systems as well as to the utilization of HF radar wave parameters that could be envisaged for data assimilation in wave models
Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics
Modern gas detectors for detection of particles require F-based gases for
optimal performance. Recent regulations demand the use of environmentally
unfriendly F-based gases to be limited or banned. This review studies
properties of potential eco-friendly gas candidate replacements.Comment: 38 pages, 9 figures, 8 tables. To be submitted to Journal of
Instrumentatio
Candidate eco-friendly gas mixtures for MPGDs
Modern gas detectors for detection of particles require F-based gases for optimal performance.Recent regulations demand the use of environmentally unfriendly F-based gases t o be limited or banned. This review studies properties of potential eco-friendly gas candidate replacements
Amoxicillin in water: Insights into relative reactivity, byproduct formation, and toxicological interactions during chlorination
In recent years, many studies have highlighted the consistent finding of amoxicillin in waters destined for wastewater treatment plants, in addition to superficial waters of rivers and lakes in both Europe and North America. In this paper, the amoxicillin degradation pathway was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants at three different pH values. The structures of 16 isolated degradation byproducts (DPs), one of which was isolated for the first time, were separated on a C-18 column via a gradient HPLC method. Combining mass spectrometry and nuclear magnetic resonance, we then compared commercial standards and justified a proposed formation mechanism beginning from the parent drug. Microbial growth inhibition bioassays with Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were performed to determine the potential loss of antibacterial activity in isolated degradation byproducts. An increase of antibacterial activity in the DPs was observed compared to the parent compound
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