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The present work describes a new method to produce membranes of poly(Acrylic-acid-Xmonomer) using the grafting procedure. PVDF foils irradiated with Ar + beam with energies between 30 and 150 keV were employed as substratum. Different combinations of monomers in water solutions were used: acrylic acid (AAc); acrylic acid–glycidyl methacrylate (AAc–GMA); acrylic acid–styrene (AAc–S), acrylic acid-N-isopropyl acrylamide (AAc–NIPAAm) and acrylic acid- N -isopropyl acrylamide–glycidyl methacrylate (AAc-NIPAAm–GMA). A large percentage of grafting results for specific values of: ion fluence and energy, AAc and sulfuric acid concentration, and different substrata PVDF polymorphous (alpha or beta). At a particular time of the grafting process, the poly(AAc-Xmonomer) membranes detach from the substratum and continue their grafting in the solution. This method is useful to produce increased replicated membranes of the irradiated original surface.

Ion beam irradiation is a well known means to change the physico-chemical properties of polymers, and induced bio and citocompatibility in controlled conditions and in selected areas of surface. However, the enhancement of cell adhesion on a modified substrate does not mean that the surface is adequate for functional cells. The purpose of the present work is to study proliferation, changes in cytoskeleton and cell morphology on substrates as a function of irradiation parameters. We irradiated polypropylene with sulfur (S) ion-beam at energies of 110 MeV with fluences between 1 × 106 and 2 × 1010 ions cm−2. NIH 3T3 cells were cultured on each sample. Cell morphology was observed using phase contrast microscopy and cytoskeleton proteins with fluorescence microscopy. The analysis show different cellular responses as a functions of irradiation parameter, strongly suggests that different underlying substratum can result in distinct types of cytoskeleton reorganization. Fil: Arbeitman, Claudia Roxana. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ibañez, Irene Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Garcia Bermudez, Gerardo Jose. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Duran, Hebe Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina Fil: del Grosso, Mariela Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina Fil: Salguero, Noelia. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina Fil: Mazzei, Rubén Omar. Comisión Nacional de Energía Atómica; Argentina

When polymers are irradiated with heavy ions new chemical groups are created in a few microns of the material. The irradiation changed the polarity and wettability on the surface so that could enhance the biocompatibility of the modified polymer. The study of chemistry and nanoscale topography of the biomaterial is important in determining its potential applications in medicine and biotechnology, because their strong influence on cell function, adhesion and proliferation. In this study, thin films of Polystyrene and Polypropylene samples were modified by irradiation with low energy ion beams (30-150 keV) and swift heavy ions both with various fluences and energies. The changes were evaluated with different methods. Adhesion of NIH 3T3 fibroblasts onto unirradiated and irradiated surfaces has been studied by in vitro techniques. The correlations between physicochemical properties as a function of different irradiations parameters were compared with cell adhesion on the modified polymer surface. Fil: Arbeitman, Claudia Roxana. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: del Grosso, Mariela Fernanda. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ibañez, Irene Laura. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Garcia Bermudez, Gerardo Jose. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Duran, Hebe Alicia. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Chappa, Veronica Cecilia. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Mazzei, Rubén Omar. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina Fil: Behar, M.. Universidade Federal do Rio Grande do Sul; Brasil

When ions suddenly pass through a polymeric material a very complex path of excited and ionized molecules is induced. Experimental data of grafting yield and new chemical groups formation present a maximum as a function of radiation fluence. We have found a correlation between this characteristic ion fluence and the stopping power. Their values lie approximately on a straight line with a negative slope and this correlation persists for an extended range, almost two orders of magnitude in stopping power variations. In the present work we will try to explain the observed correlation applying a known radial distribution of deposited energy induced by ion interaction with polymers.

In order to continue with a systematic study that include different polymers and monomers, the residual active sites produced by heavy ion beams, that remain after the etching process, were used to start the grafting process. To produce tracks, foils of polypropylene (PP) were irradiated with 208 Pb of 25.62 MeV/n. Then, these were etched and grafted with acrylic acid (AA) monomers. Experimental curves of grafting yield as a function of grafting time with the etching time as a parameter were measured. Also, the grating yield as a function of the fluence and etching time was obtained. In addition, the permeation of solutions, with different pH, through PP grafted foils was measured.

The present work is part of a systematic study that involves different polymeric substrates and monomers with the purpose to induce grafting on etched tracks. The residual active sites produced by heavy ion beams, remaining after the etching process, were used to start the grafting process. In order to produce tracks on foils of poly(vinylidene fluoride) (PVDF) they were irradiated with 208 Pb of 25.62 MeV/n or with 115 MeV Cl ions. Then, they were etched and grafted with N -isopropylacrylamide (NIPAAm) monomers. Experimental curves of grafting yield as a function of fluence with the etching time as a parameter were measured. Also, the grafting yield as a function of the grafting and etching time was obtained. The replica method allowed the observation of the shape of the grafted tracks using transmission electron microscopy (TEM). In addition NIPAAm grafted foils were analyzed using Fourier transform infrared spectroscopy (FTIR).

Polypropylene (PP) and poly(vinylidene fluoride) (PVDF) films were irradiated with 100 keV Argon ions and with different fluences from 1012 up to 2 × 1015 cm−2. PP and PVDF films were grafted with styrene and PVDF was also grafted with acrylic acid (AA). The grafting yields were determined by measuring the weight differences and analysing the Fourier transform infrared (FTIR) and UV–visible (UV–Vis) spectra. The effects on the measured grafting yields for different ion fluences and monomer concentrations were studied and are reported in this paper. The grafting yield exhibit the common feature of showing a maximum as a function of the ion fluence. To our knowledge the present work study systematically for the first time the grafting process induced by the irradiation with low energy Argon beams on the surface of PVDF and PP samples.

Poly(propylene) foils were irradiated with Ag ions and then chemically etched to produce samples with structured surfaces. After the etching procedure the active sites that remain on the latent track were used to graft acrylic acid. Nuclear tracks before grafting were visualised using a transmission electron microscope. The grafting yields were determined by weight measurements as a function of ion fluence, etching and grafting time, and were also analysed using Fourier transform infrared spectroscopy. Both measurements suggest that the acrylic acid was grafted on etched tracks using the active sites produced by the swift heavy ion beam.

Structural analysis with infrared spectroscopy was carried out on ultra-high molecular weight polyethylene (UHMWPE). The polyethylene was irradiated using Li, C, N, S and I heavy ion beams with different fluences. The analysis showed that the absorbance of the C C stretching vibration from trans-vinylene groups containing hydroperoxides presents a maximum at certain ion fluence and is correlated with the ion stopping power. The results were analyzed by a Monte Carlo simulation program that models the irradiation process from a geometrical point of view, in which the latent tracks consist in a central core zone surrounded by a larger perturbed region. This study suggests that it is possible to estimate the core dimension from absorbance measurements as a function of fluence. A possible relationship between this C C structure with the cross-link of two polymeric chains is discussed.

Polypropylene (PP) foils were irradiated with 100 keV energy Argon ions at different fluences ranging from 1012 up to 2 × 1015 cm−2 and then grafted with acrylic acid (AA). The grafting yield was measured by weight difference and the structural changes on the films were analysed using Fourier transform infrared spectroscopy (FTIR). Different parameters that determined the grafting process such us fluence, grafting time and monomer concentration were analysed. The grafting reached an optimum value at 79% in aqueous solution at 30 min grafting time. The grafting yield as a function of the ion fluence plot, presented a maximum value, as previously found in a study of heavy beam on polymers.

The surface of the polymer was modified by the effects of different radiations. Foils of poly(vinylidene fluoride) were irradiated with different swift heavy ions such us: proton, alpha particles, chlorine and fission fragments. The active sites created by the irradiation of the polymer were used to graft different monomers likes: styrene, HEMA, MMA, AA and NIPAAm. The grafting yield was measured as a function of the ion fluence and its results interpreted using a theoretical model based on the target theory. The correlation between the maximum of the grafting yield versus the ion mass was discussed.

The radiation induced graft polymerisation is a well known method to obtain new materials. Until recently only conventional radiation sources, such as 60 Co and electron beams were used. Moreover, part of the damage induced in polymers by heavy ions can produce active sites (peroxides and hydroperoxides) useful to initiate grafting reactions. In this way, the damage induced in polypropylene (PP) by a 25 MeV proton beam was used to initiate grafting reactions by the peroxide method. So, polymer surface modification was obtained by grafting different monomers onto PP films. The present work shows the grafting yield of acrylic acid, methyl methacrylate and styrene as a function of proton fluency and dose. The experimental points obtained by grafting PP foils were fitted according to the equations deduced supposing the target theory

Polymer surface modifications are obtained by the application of radiation treatments and other physico-chemical methods: fission fragment (ff) irradiation and etching. The biocompatibility of the surface is then observed by cell seeding and cell adhesion experiments. Approaches to improvement of the cell adhesion are obtained by different methods: for example, in PS, cell adhesion is improved after ion implantation; in PMMA, after bombarding the polymer, the surface is reconditioned with surfactants and proteins and in PVDF, cell adhesion is assayed on nuclear tracks membranes. In this work, we obtained important cell adhesion improvements in PP films by irradiation with swift heavy ions and subsequent etching of the nuclear tracks. We use BOPP (isotactic −25 μm thickness). Irrradiations were performed with a Cf-252 californium ff source. The source has a heavy ff and a light one, with 160–200 MeV energy divided among them corresponding to ff energies between 1 and 2 MeV/amu. A chemical etching procedure consisting of a solution of sulphuric acid and chromium three oxide at 85 °C was used. The 3T3 NIH fibroblast cell line was used for the cell adhesion experiment. Here we report for the first time, the results of a series of experiments by varying the ff fluence and the etching time showing that attachment and spreadout of cells are very much improved in this cell line according to the number of pores and the pore size.

Polymer surface modifications are obtained by the application of radiation treatments and other physico-chemical methods: fragment fission (ff) or ion implantation, etching and grafting procedure. Poly vinylidene fluoride (PVDF) foils were irradiated during different times to produce pores of different diameters through the foils. In this way, nuclear track membranes (NTM) were produced with different track diameters and track numbers. Active sites were formed using a γ-ray Co-60 source and then contacted with N-isopropylacrylamide (NIPAAm) to obtain a graft copolymer that responds to environmental conditions. The present work shows the grafting yield as a function of: γ-dose, NIPAAm concentration, pore diameter, track density, etc.

Two galactolipids, 1 and 2, were isolated and identified both in olive fruits and in olive oil. They are characterized by a low polarity, despite the presence of a diglycosidic unit, giving, in water, micelles. Because of this characteristic, compounds 1 and 2 could be responsible for the stability of the light emulsion typical of freshly produced olive oil. The presence of hydrophilic ortho-diphenolic compounds enhances the antioxidant properties of this oil, particularly in the first period after the production. In addition, the functions present in 1 and 2 are susceptible to hydrolysis and may be easily modified in the alkaline treatment used for the olive oil refining process. For this reason, their presence in olive oil may be a very useful indication of the untreated food product.

The synthesis of a new carbocyclic nucleoside, starting from a natural methylcyclopentanoid monoterpene, has been performed, allowing preparation of a carbovir analog, with a highly functionalized cyclopentane. © 1997 Published by Elsevier Science Ltd.

Chemically etched ion tracks in solid state nuclear detectors are studied in detail searching for a correlation between track profile inhomogeneities — breaks — and ion charge change events. Beams of 36 MeV carbon ions in charge states 3 + to 6 + bombarded 300 μm thick Macrofol-E foils. Etched track replicas were obtained and analyzed with an electron microscope. Microphotographed profiles were fitted with a mathematical model able to follow fast slope changes in track profiles. Lengths related to profile breaks were extracted and considered as mean free paths for charge exchange. These results compare favourably with published cross section values.

We report three theoretical methods which yield, by means of a computer program, the theoretical Submicroscopic and microscopic track profiles corresponding to normal incidence ions for velocities of chemical attack which vary with the position on the incidence axis (x) of the ion and the perpendicular distance measured on the y axis. The program can simulate tracks for cases in which there are weak or sharp fluctuations in the physical damage. These fluctuations may come statistical changes in the damage or changes in the charge state of the incident ion. We report here an alternative solution for problems identified in earlier studies (e.g. G. Somogyi and S.A. Slazay, Nucl. Instr. and Meth. 109 (1973) 211 and R. Mazzei et al., Nucl. Instr. and Meth. B9 (1985) 163) for the microscopic and Submicroscopic tracks, respectively.

A theoretical description for submicroscopic kinetics of track formation is described. On the other hand the variational principle was used to obtain the equations for the track profile. Moreover, three theoretical methods are reported which yield, by a computer program, the theoretical submicroscopical track profiles for velocities of chemical attack which vary with the position on the incidence axis (x) of the ion and the perpendicular distance measured on the axis. It can simulate tracks for cases in which there are changes in the physical damage owing to statistical changes or state changes in the incident ion charges.

The central activated region of tracks is analyzed, by means of the folding track replica method up to a resolution of 10 A, using chemical etching, for different ions and energies. The data indicate that the mean track velocity considered at specific radial intervals os the track profile is not a unique function of the corresponding mean delivered dose. This function also depends on the ion species. The Vareille and Tombrello model and the experimental results are discussed for the track damage region. For a better knowledge of track formation mechanisms post-irradiation dynamic processes must be considered.

The central activated region of tracks is analyzed,by means of chemical etching,up to a resolution of 10 A by the folding track replica method for different ions and energies. The data indicate that post-irradiation dynamic processes must be considered to gain a better understanding of track formation mechanisms and of final distribution of damage.

Cl or Pb irradiated foils of poly(vinylidene fluoride) (PVDF) were chemically etched to produce nuclear track membranes (NTM) with submicroscopic pores. The NTM were grafted with styrene using the remaining active sites produced by the heavy ion beams. Experimental curves of grafting yield were measured by weight difference as a function of ion fluence and etching time. As the etching time was increased from 0 to 30 min a decrease of the grafting yield was observed. Grafted foils were also analysed by Fourier transform infrared spectroscopy (FTIR). Both measurements suggest that the styrene was grafted on the pore wall of the NTM using the active sites left by the ion beam.

The synthesis of a new carbocyclic nucleoside starting from aucubin, a natural methylcyclopentanoid monoterpene, has been performed, allowing the preparation of aucubovir II, a carbocyclic nucleoside analog with a highly functionalized cyclopentane ring. The stereocontrol of the coupling reaction was complete, utilizing the procedure described by Vorbruggen with a purinic base.

The molecular structure of the microcomponents of olive fruit was investigated in order to evidence new molecules which could be transferred to the resulting oil and therefore be typical of olive oil. The three glucosides of 2(3,4-dihydroxy-phenyl)ethanol, 1, 2 and 3 were isolated together with other glucosides previously identified in Olea europaea. Glucosides 1–3 were detected in the olive oil, there being always present a small quantity of water as an emulsion, together with the aglycone, the 2(3,4-dihydroxy-phenyl)ethanol. The presence of glucosides 1–3 is closely linked with the organoleptic characteristics and to the recognized antioxidant properties of olive oil..

A macroscopic technique which involves only a few minutes' processing, for the evaluation of the induction time was previously used only in organic materials. This methodology is extended to evaluate the induction time in inorganic materials (muscovite mica).

Three theoretical descriptions that yield, using a computer program, theoretical submicroscopical track profiles corresponding to normal incidence ions are proposed. The chemical attack velocity was assumed to vary with the position on the incidence axis (x) of the ion and the perpendicular distance measured on the y axis. The program can simulate profiles for cases in which there are changes in the physical damage due to statistical changes or state changes in the incident ion charges. Moreover, the effects of the fluctuations in the bulk material on the track profiles as well as the experimental track profiles are shown.

The classic method for the evaluation of the induction time in SSNTD with electron and light microscopy is based on the analysis of the evolution of track diameters as a function of etching time and the extrapolation to zero diameter. The present study outlines a simple method to evaluate the induction time, which is based on the evaluation of changes in light transmission in the irradiated area of the foil. This change is the result of the collective effect of tracks (diameters of less than 500 A) in saturated foils which can be visualized as individual tracks only by electron microscopy.

The analysis of the effect of soaking in alcohol and/or water in track development was evaluated in Makrofol E using electron microscopy. Alcohol seems to be the main cause of track development when no other chemical reagent is used. No track development is achieved when water is used as an etching agent.

The submicroscopic track kinetic theory (STKT) is able to deal with a broad range of cases. We derive here its behaviour for very short etching times (new born tracks) and also for long etching times, where the classical track kinetic theory is a particular case of the STKT. Experimental data obtained previously by Bean et al. using the electroconductivity method are then analyzed by the STKT method. We show that good agreement is obtained between Bean and STKT theoretical results for the track diameter evolution.

Chemical etching track profiles in the bulk region, as well as in the physical damage region, were described in a track kinetic theory by Mazzei et al. applying submicroscopic evaluations. In the present work this theory proves useful also to analyze the profiles of “new born” tracks. The equation describing height variations along each track profile is similar to that describing track velocity variation along the axis perpendicular to the ion incidence direction. The theory proves that for “new born” tracks, the chemical etching wave fronts generated in any point of the track are not exceeded by that wave front generated along the heavy ion incidence axis.

A theoretical description for submicroscopic kinetics of track formation in SSNTD is proposed. Kinetics of chemical attack in the primary damage region of the track is included. A good correlation between theory and experimental data obtained with Mazzei's replica method is achieved.

After a single injection of formaldehyde-treated 131 I-albumin into the heart, the incorporation of the labelled protein by liver (% of total injected radioactivity/% of body weight of the organ) was far greater than in other organs. In kidney and spleen it was respectively six and three times greater than in lungs, intestine, testis and fatty body. No radioactivity was found in brain. The radioactivity in liver and kidney reached a peak 30 minutes after the injection, and quickly decreased during the following four hours. In the 27,000 g × ten minute particles recovered from liver homogenates of animals sacrificed at various times after injection, the rate of 131 I-albumin hydrolysis in vitro and the percentage of trichloroacetic acid soluble radioactivity at zero time of incubation showed different stages of intraparticulate hydrolytic activity. The incorporation and intraparticulate hydrolysis in toad kidney was very low if compared with that of toad liver or mouse kidney; however the catheptic specific activity in toad kidney doubles that of mouse kidney. Isolated toad liver was perfused with total blood, containing 131 I-albumin, for five hours at 22°C in a special chamber. In this conditions, 16% of the labelled albumin was hydrolyzed by the liver.

Rat tail epidermis was used to analyze the in vivo response of a biological system to heavy particle irradiation. The conical configuration of the rat tail gives rise to a variable energy degradation of the beam thus yielding information on the damage elicited by 2 different L.E.T. regions of the helium beam at different sites on the same sample. Cytochrome oxidase activity and epidermal thickness were used to analyze the metabolic and structural radioinduced response. Quantitative evaluation of radiation damage revealed marked variations within a few micrometers of tissue.

The enzymatic activity of five acid hydrolases: acid phosphatase, arylsulfatase A, deoxyribonuclease, β-glucuronidase, and cathepsin D, was assayed in fetal (fifteenth and eighteenth days of pregnancy) and neonatal (Days 0, 5, 10, and 15 post-partum) mouse liver. With the exception of cathepsin D, the activity increased around birth to levels varying according to the enzyme. Histochemical observations of other authors appear to justify, at least in part, the present results, which indicate that late days of fetal development and early neonatal life may constitute a transitional stage to full lysosomal enzyme functionality of the adult organ The livers of the mothers were also assayed for the same enzymes. Each activity showed a peculiar pattern which was, in turn, different from that found in the liver of the litter for the same enzyme, probably as a cause of the metabolic requirement of the gland The hypothesis that the lysosomes are heterogeneous in their enzyme composition is suggested by the variety of enzymatic patterns found in the liver of the litters and their mothers.