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1.
Rep Prog Phys ; 82(5): 056301, 2019 05.
Article in English | MEDLINE | ID: mdl-30736024

ABSTRACT

The present review summarizes the recent studies on the thermodynamic properties of pairing in many-body systems including superconductors, metallic nanosized clusters and/or grains, solid-state materials, focusing on the excited nuclei, that is nuclei at finite temperature and/or angular momentum formed via heavy-ion fusion, [Formula: see text]-induced fusion reactions, or inelastic scattering of light particles on heavy targets. Because of the finiteness of the systems, several interesting effects of pairing such as nonvanishing pairing gap, smoothing of superfluid-normal phase transition, first and second order phase transitions, pairing reentrance, etc, will be discussed in detail. Influences of exact and approximate thermal pairing on some nuclear properties such as temperature-dependent width of the giant dipole resonance, total level density, and radiative strength function of the [Formula: see text]-rays emission will be also analyzed. Finally, the first experimental evidence of the pairing reentrance phenomenon in a 104Pd nucleus as well as its solid-state counterpart of ferromagnets under strong magnetic field will be presented.

2.
Nanoscale Adv ; 1(9): 3626-3638, 2019 Sep 11.
Article in English | MEDLINE | ID: mdl-36133537

ABSTRACT

The efficient targeting of cancer cells depends on the success of obtaining the active targeting of overexpressed receptors. A very accurate design of nanoconjugates should be done via the selection of the conjugation strategy to achieve effective targeted nanoconjugates. Here, we present a detailed study of cetuximab-conjugated nonspherical gold nanocages for the active targeting of triple-negative breast cancer cells, including MDA-MB-231 and MDA-MB-468. A few different general strategies were selected for monoclonal antibody conjugation to the nanoparticle surface. By varying the bioconjugation conditions, including antibody orientation or the presence of a polymeric spacer or recombinant protein biolinker, we demonstrate the importance of a rational design of nanoconjugates. A quantitative study of gold content via ICP-AES allowed us to compare the effectiveness of cellular uptake as a function of the conjugation strategy and confirmed the active nature of nanoparticle internalization in cancer cells via epidermal growth factor receptor recognition, corroborating the importance of the rational design of nanomaterials for nanomedicine.

3.
Anal Chim Acta ; 946: 9-39, 2016 Nov 23.
Article in English | MEDLINE | ID: mdl-27823674

ABSTRACT

The use of graphene in the field of electrochemical sensors is increasing due to two main properties that make graphene and derivatives appealing for this purpose: their conductivity and high surface area. In addition, graphene materials can be easily functionalized with nanoparticles (Au, Pt, etc.) or organic molecules (DNA, polymers, etc.) producing synergies that allow higher sensitivity, lower limit of detection as well as increased selectivity. The present review focuses on the most important works published related to graphene-based electrochemical sensors for the determination of hazardous ions (such as As(III), Cd2+, Pb2+, Hg2+, Cr(VI), Cu2+, Ag+, etc.). The review presents examples of the use of graphene-based electrodes for this purpose as well as important parameters of the sensors such as: limit of detection, linear range, sensitivity, main interferences, stability, and reproducibility. The application of these graphene-based electrodes in real samples (water or food matrices) is indicated, as well. There is room for improvement of these type of sensors and more effort should be devoted to the use of doped graphene (doped for instance with N, B, S, Se, etc.) since electrochemically active sites originated by doping facilitate charge transfer, adsorption and activation of analytes, and fixation of functional moieties/molecules. This will allow the sensitivity and the selectivity of the electrodes to be increased when combined with other materials (nanoparticles/organic molecules).


Subject(s)
Electrochemistry/methods , Environmental Pollutants/analysis , Graphite/chemistry , Metals, Heavy/analysis , Animals , Electrochemistry/instrumentation , Environmental Pollutants/chemistry , Humans , Metals, Heavy/chemistry
4.
Nanotechnology ; 22(18): 185305, 2011 May 06.
Article in English | MEDLINE | ID: mdl-21427473

ABSTRACT

Ordered arrays of nanoelectrodes for electrochemical use are prepared by electron beam lithography (EBL) using polycarbonate as a novel e-beam resist. The nanoelectrodes are fabricated by patterning arrays of holes in a thin film of polycarbonate spin-coated on a gold layer on Si/Si(3)N(4) substrate. Experimental parameters for the successful use of polycarbonate as high resolution EBL resist are optimized. The holes can be filled partially or completely by electrochemical deposition of gold. This enables the preparation of arrays of nanoelectrodes with different recession degree and geometrical characteristics. The polycarbonate is kept on-site and used as the insulator that separates the nanoelectrodes. The obtained nanoelectrode arrays (NEAs) exhibit steady state current controlled by pure radial diffusion in cyclic voltammetry for scan rates up to approximately 50 mV s( - 1). Electrochemical results showed satisfactory agreement between experimental voltammograms and suitable theoretical models. Finally, the peculiarities of NEAs versus ensembles of nanoelectrodes, obtained by membrane template synthesis, are critically evaluated.

5.
Braz. j. phys. ther. (Impr.) ; 13(2): 130-135, Mar.-Apr. 2009. tab
Article in English, Portuguese | LILACS | ID: lil-516037

ABSTRACT

Objetivo: Descrever a prevalência da utilização de serviços de fisioterapia entre a população adulta urbana de Lages (Santa Catarina) segundo variáveis demográficas e socioeconômicas. Métodos: Realizou-se um estudo transversal de base populacional com amostra obtida em múltiplos estágios e composta por adultos entre 20 e 59 anos (n=2.051). Os dados foram coletados por meio de entrevistas domiciliares em que se obteve a informação por parte dos sujeitos de pesquisa sobre o uso, em algum momento da vida, de serviços de fisioterapia. Foi calculada a prevalência desse desfecho para a população global segundo sexo, idade, escolaridade, autoavaliação em saúde e renda. Resultados: Observou-se que a prevalência da utilização de serviços de fisioterapia foi de 33,5% (IC95% 33,0%-39,8%) entre os homens e de 31,5% (IC95% 28,9%-34,1%) entre as mulheres. Quanto às demais variáveis demográficas investigadas, verificou-se que a prevalência do uso da Fisioterapia aumentou de acordo com a idade dos indivíduos, sendo o maior valor relatado no grupo de 50 a 59 anos (47,2%; IC95% 42,4%-52,0%) e foi maior entre as pessoas que referiram cor amarela (45,9%; IC95% 29,1%-62,7%). Em relação às variáveis socioeconômicas, constatou-se que grupos com melhores indicadores reportaram maior uso do serviço, sendo esse valor equivalente a 46,9% (IC95% 42,3%-51,5%) no estrato de maior renda e a 37,5% (IC95% 34,4%-40,7%) entre aqueles de 12 a 15 anos de estudo. Conclusão: Observou-se, no presente estudo, que o uso de serviços de fisioterapia variou na população de acordo com as características socioeconômicas e demográficas das pessoas investigadas.


Objective: To describe the prevalence of physical therapy service use among the urban adult population of Lages (Santa Catarina), according to demographic and socioeconomic variables. Methods: A population-based cross-sectional study with multiple-stage sampling was carried out among adults aged 20 to 59 years (n=2051). Data were gathered by means of interviews at the participants’ home, in which they provided information on the use of physical therapy services over their lifetime. The prevalence of this outcome was estimated for the entire population according to sex, age, educational level, self-evaluation of health, and income. Results: The prevalence of physical therapy service use was 33.5% (95% CI: 33.0%-39.8%) among men and 31.5% (95% CI: 28.9%-34.1%) among women. Regarding the other demographic variables investigated, the prevalence of physical therapy use increased with age and was highest among the 50 to 59 year-old group (47.2%; 95% CI: 42.4%-52.0%). The prevalence was also higher among participants of self-reported Asian background (45.9%; 95% CI: 29.1%-62.7%). Regarding socioeconomic variables, it was observed that groups with better indicators reported greater service use: 46.9% (95% CI: 42.3%-51.5%) in the highest income range and 37.5% (95% CI: 34.4%-40.7%) in the range of 12 to 15 years of education. Conclusion: The present study found that physical therapy service use varied among this population according to the participants’ socioeconomic and demographic characteristics.

6.
Phys Rev Lett ; 100(15): 152501, 2008 Apr 18.
Article in English | MEDLINE | ID: mdl-18518099

ABSTRACT

The lifetime of the 2_+(1) state in 16C has been measured with the recoil distance method using the 9Be(9Be,2p) fusion-evaporation reaction at a beam energy of 40 MeV. The mean lifetime was measured to be 11.7(20) ps corresponding to a B(E2;2_+(1)-->0+) value of 4.15(73)e_2 fm_4 [1.73(30) W.u.], consistent with other even-even closed shell nuclei. Our result does not support an interpretation for "decoupled" valence neutrons.

7.
Phys Rev Lett ; 94(20): 202701, 2005 May 27.
Article in English | MEDLINE | ID: mdl-16090240

ABSTRACT

The effects of the finite size of a liquid drop undergoing a phase transition are described in terms of the complement, the largest (but mesoscopic) drop representing the liquid in equilibrium with the vapor. Vapor cluster concentrations, pressure, and density from fixed mean density lattice gas (Ising) calculations are explained in terms of the complement generalization of Fisher's model. Accounting for this finite size effect is important for extracting the infinite nuclear matter phase diagram from experimental data.

8.
J Hazard Mater ; 126(1-3): 141-8, 2005 Nov 11.
Article in English | MEDLINE | ID: mdl-16087289

ABSTRACT

This study deals with the biodegradation of the polycyclic aromatic hydrocarbons (PAH)s present in a soil contaminated by soot waste, characterised by a total PAHs content in the 200 mg kg(-1) range. A challenging characteristic of the waste soil treated was its high alkalinity, with a pH of about 12.8. The waste came from a soot-contaminated area located in the industrial zone of Porto Marghera, Venice (Italy). The biodegradation process employed was the composting of the waste with sewage sludge and yard waste. The process was carried out on a pilot scale using a closed tank with forced aeration for a period of 60 days, followed by 70 days with natural aeration. The time evolution of the process was monitored by following the time change in the concentration of the 16 US-EPA PAHs, as well as temperature, pH, electrical conductivity, C and N contents. Also phytotoxicity parameters, such as the growth and respiration indexes, were monitored. An induction time of about 30 days was observed, which corresponded to the time required before observing a significant self-drop in the waste pH and an increase in mass temperature. Afterward, a progressive drop in the PAHs concentration was observed, up to reaching after 130 days an overall degradation percentage in the order of 68%. The degradation was more effective on rather low molecular weight PAHs (2-4 rings).


Subject(s)
Alkalies/metabolism , Carbon/metabolism , Environmental Pollution/prevention & control , Polycyclic Aromatic Hydrocarbons/metabolism , Soil Pollutants/metabolism , Soil , Biodegradation, Environmental , Hydrogen-Ion Concentration , Kinetics , Temperature
9.
Phys Rev Lett ; 88(4): 042701, 2002 Jan 28.
Article in English | MEDLINE | ID: mdl-11801117

ABSTRACT

The thermal component of the 8 GeV/c pi+ Au data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model when Coulomb energy is taken into account. Critical exponents tau and sigma, the critical point (p(c),rho(c),T(c)), surface energy coefficient c(0), enthalpy of evaporation DeltaH, and critical compressibility factor C(F)(c) are determined. For the first time, the experimental phase diagrams, (p,T) and (T,rho), describing the liquid vapor coexistence of finite neutral nuclear matter have been constructed.

10.
Med Phys ; 26(5): 793-8, 1999 May.
Article in English | MEDLINE | ID: mdl-10360544

ABSTRACT

Neutron yields and energy spectra have been measured for various deuteron-induced reactions at low energy. Neutrons of energy > 100 keV emitted in the 9Be(d,n)10B, 12C(d,n)13N, and 13C(d,n)14N reactions at Ed= 1.5 MeV were detected at five angles by means of liquid scintillator detectors. While low-energy neutrons were observed in all studied reactions, only 13C(d,n)14N is characterized by a relatively large yield with spectral features potentially interesting for an accelerator-based neutron source for BNCT.


Subject(s)
Neutron Capture Therapy/instrumentation , Neutron Capture Therapy/methods , Radiotherapy Planning, Computer-Assisted , Beryllium/therapeutic use , Boron/therapeutic use , Carbon/therapeutic use , Carbon Isotopes , Nitrogen/therapeutic use , Nitrogen Radioisotopes/therapeutic use
11.
Anal Chem ; 68(23): 4160-5, 1996 Dec 01.
Article in English | MEDLINE | ID: mdl-21619326

ABSTRACT

Ensembles of nanoscopic disk-shaped electrodes have been shown to offer enhancements in electroanalytical detection limits relative to electrodes of macroscopic dimensions (e.g., disk electrodes with diameters of ∼1 mm). Enhancements in electroanalytical detection limits have also been observed at macroscopic electrodes that have been coated with films of ion-exchange polymers. In this paper we combine these two concepts. We demonstrate that a nanoelectrode ensemble (NEE) that has been coated with a thin film of the Kodak ion-exchange polymer AQ 55 shows enhanced electroanalytical detection limits relative to the uncoated NEE and to the coated macroscopic electrode. To our knowledge, this is the first investigation of the electrochemistry, and the electroanalytical advantages, of polymer film-coated NEEs.

12.
Talanta ; 37(3): 317-24, 1990 Mar.
Article in English | MEDLINE | ID: mdl-18964944

ABSTRACT

Trace amounts of thorium have been determined in the presence of uranyl nitrate and ammonium diuranate (as interferents) by cyclic voltammetry, differential-pulse polarography, differential-pulse voltammetry, square-wave voltammetry and anodic-stripping voltammetry. The determination is based on the substitution of thorium for copper, lead and cadmium in their EDTA complexes and voltammetric measurement of the displaced metal ion. The detection limits ranged between 2 x 10(-7) and 1 x 10(-6)M (r.s.d. 2-7%) for solutions free from the uranium compounds, and between 8 x 10(-7) and 5 x 10(-6)M (r.s.d. 3-5%) in the presence of the uranium compounds at concentrations up to about 1000 times that of thorium. The detection limits depend on both the particular technique and the EDTA complex employed. Anodic-stripping voltammetry gave detection limits of 8 x 10(-8) and 10(-7)M in the absence and presence of uranium respectively.

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