Search

Excitation functions were measured by the activation method using the stacked-foil technique for the natMo(p,x)93(m+g),94m,g,95m,g,96(m+g),99mTc, 92m,95Nb reactions up to 18 MeV. The experimental results were compared with literature data and theoretical results from EMPIRE-3.2.2 code and TENDL. Special attention was paid to the 100Mo(p,2n)99mTc reaction which is very promising for the production of 99mTc at a cyclotron. In order to optimize the production conditions of some medically important Tc isotopes, the integral yields were estimated based on the measured cross sections.

Excitation functions were measured by the activation method using stacked-foil technique for the natSr(p,xn)88,87m,g,86m,gY reactions up to 18 MeV. The experimental results were compared with the theoretical data from EMPIRE-3.2 code and TENDL. Integral yields of 88,87m,g,86m,gY were estimated based on the measured cross sections. The optimum energy range for the production of the important isotope 88Y is Ep = 16→11 MeV, 88Y yield amounts to about 3 MBq/µAh.

The rapid synthesis of two radiofluoronicotinamide derivatives, namely, [18F]MEL050 and [18F]MEL-2F has been simply performed starting from commercial materials. [18F]MEL-2F is a new, potential analogue PET-probe for melanoma imaging. [18F]MEL050 is already an excellent PET imaging probe for early specific diagnosis. The synthesis involves coupling step to obtain the precursor followed by radiofluorination. During the synthesis of the precursors different coupling reagents, such as HBTU, TFFH, HOBT, COMU and PyCIU have been applied. PyClU was found the best to reduce the coupling period to

Understanding the nature of polymers used as nuclear detectors is crucial to enhance their behaviors. In this work, the induced modifications in wettability and etching properties of Hostaphan and Makrofol polymers irradiated by different fluences of thermal neutrons are investigated. The wetting properties are studied by contact angle technique which showed the spread out of various liquids over the irradiated polymers surfaces (wettability enhanced). This wetting behavior is attributed to the induced changes in surface free energy (SFE), morphology, roughness, structure, hardness, and chemistry. SFE values are calculated by three different models and found to increase after neutrons irradiation associated with differences depending on the used model. These differences result from the intermolecular interactions in the liquid/polymer system. Surface morphology and roughness of both polymers showed drastic changes after irradiation. Additionally, surface structure and hardness of pristine and irradiated polymers were discussed and correlated to the surface wettability improvements. The changes in surface chemistry are examined by Fourier transform infrared spectroscopy (FTIR), which indicate an increase in surface polarity due to the formation of polar groups. The irradiated polymers etching characteristics and activation energies are discussed as well. Lastly, it is evident that thermal neutrons show efficiency in improving surface wettability and etching properties of Hostaphan and Makrofol in a controlled way.

Iodobenzamides are reported to possess some affinity for melanoma. This study describes the synthesis of a new benzamide analogue, N-(2-diethylamino-ethyl)-4-(4-chloro-nicotinamido)-5-[125I]iodo-2-methoxybenzamide ([125I]H4) designed to target melanoma. The synthesis was simply achieved in four steps. There were two PyCIU/DIPEA amide condensations and a transfer hydrogenation using an ammonium formate hydrogen donor. The radioiodination step was carried out with 125I via an electrophilic substitution reaction. The reaction conditions were optimized. The labeled compound was purified by HPLC. The maximum radiochemical yield was found to be 78% at a radiochemical purity of 98%. All compounds were characterized by MS and NMR techniques. The log P value for [125I]H4 was found as 3.96±0.5.

Using stacked-foil activation technique and gamma-ray spectrometry, excitation functions for 3He induced nuclear reactions on natV were measured. Cross-sections for natV(3He, xn)52m,gMn and natV(3He, pxn)51Cr nuclear reactions were measured up to 27 MeV utilizing the MGC-20E cyclotron of ATOMKI. The measurements establish for the first time consistent excitation curves. Comparisons with results for values derived from different theoretical codes were included. Integral yield were calculated.

Excitation functions were measured by the activation method using stacked-foil technique for the

Excitation functions for $$\alpha $$ -induced reactions on natural vanadium were measured in the energy range up to 20 MeV. The stacked-foil activation technique was used. The experimental results were compared with the theoretical calculations using EMPIRE-3.1, EMPIRE-3.2.2 and TENDL 2015, and with earlier experimental results. Thick target yields were calculated for the production of $$^{54}\hbox {Mn}$$ and for the associated impurity $$^{52}\hbox {Mn}$$ .

One-dimensional nanoferroic rods of BaTiO 3 were synthesized by improved citrate auto-combustion technology using tetrabutyl titanate. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) have been used to characterize the prepared sample. The results indicated that the crystal structure of BaTiO 3 is tetragonal phase with an average crystallite size of 47 nm. SEM image gives a cauliflower-like morphology of the agglomerated nanorods. The stoichiometry of the chemical composition of the BaTiO 3 ceramic was confirmed by EDX. TEM micrograph exhibited that BaTiO 3 nanoparticles have rod-like shape with an average length of 120 nm and width of 43 nm. AFM was used to investigate the surface topography and its roughness. The topography image in 3D showed that the BaTiO 3 particles have a rod shape with an average particle size of 116 nm which in agreement with 3D TEM result.

Excitation functions of 3He induced nuclear reactions on natSn were measured up to 26 MeV using the stacked-foil technique, utilizing the MGC-20E cyclotron of ATOMKI. Using HPGe detector the following radioisotopes were identified: 116,117,118,119g,119m,121g,121m,123mTe, 115g,116m,117,118m,120m,122g,124gSb and 113g,117mSn. The experimental results are presented for the first time in this energy range. The results of theoretical calculations based on EMPIRE and TENDL library were compared with the present data. Integral yields for some isotopes were calculated.

The broad-spectrum antibiotic agents have been demonstrated as promising diagnostic tools for early detection of infectious lesions. We set out ofloxacin (Oflo), a second-generation fluoroquinolone, for the radioiodination process. In particular, this was carried out with 125I via an electrophilic substitution reaction. The radiochemical yield was influenced by different factors; drug concentration, different oxidizing agents, e.g. chloramine-T, iodogen and n-bromosuccinimide, pH of medium, reaction time, temperature and different organic media. These parameters were studied to optimize the best conditions for labeling with ofloxacin. We found that radiolabeling in ethanol medium showed a 70% radiochemical yield of 125I-ofloxacin. The radioiodination was determined by means of TLC and HPLC. The cold labeled Oflo (127I-Oflo) was prepared and controlled by HPLC. The cold labeled Oflo was also confirmed by NMR and MS techniques. Furthermore, biodistribution studies for labeled 125I-Oflo were examined in two independent groups (3 mice in each one); control and E. Coli-injected (inflamed). The radiotracer showed a good localization in muscle of thigh for inflamed group as compared to control. In conclusion, ofloxacine might be a promising target as an anti-inflammatory imaging agent.

Radioiodinated MIP-1145, which specifically targets melanin, is an ideal candidate for targeted therapy of melanoma. An analogue of MIP-1145 lacking the iodo-substituent (desiodo-MIP-1145) was synthesized as a labeling precursor in three simple steps. The radioiodination of desiodo-MIP-1145 by iodine-125 was carried out via an electrophilic substitution reaction. An optimization study for the iodination reaction was carried out. The labeled compound was isolated and purified by means of electrophoresis and HPLC. The maximum radiochemical yield, 76%, was obtained with radiochemical purity greater than 99%. The log P value for [(125) I]MIP-1145 was measured as 4.5.

The rapid synthesis of two radiofluoronicotinamide derivatives, namely, [

A theoretical study of the nuclear reaction cross-section for the production of 64Cu and 86Y was performed from the nuclear reactions 64Ni(p, n) 64Cu, 64Ni(d, 2n) 64Cu, 66Zn(d, α)64Cu, 68Zn(p, n α)64Cu, 86Sr(p, n) 86gY, 87Sr(p, 2n) 86gY and 88Sr(p, 3n) 86gY. The calculations were performed using three codes EMPIRE, TALYS and ALICE-IPPE. The excitation function curves for the investigated reactions have been constructed from the enriched targets using 64Ni, 66Zn, 68Zn, 86Sr, 87Sr and 88Sr. The calculated excitation functions and the experimental data were compared. Mean standardized deviation, mean relative deviation and mean ratio statistical parameters were introduced to control the quality of the fitting between both the experimentally and the theoretically calculated cross-sections.

Excitation functions of 3He-particle induced nuclear reactions on natural cadmium were measured using the standard stacked foil technique and high resolution gamma-ray spectroscopy. From their threshold energies up to 27 MeV, cross-sections for natCd(3He,xn)117m,113,111,110Sn, natCd(3He,xnp)117m,g,116m,115m,114m,113m,111,110m,g,109,108,107In, and natCd(3He,X)115g,111mCd reactions were measured. The nuclear codes TALYS, and EMPIRE-3,1 were used to describe the formation of these products. The present data were compared to theoretical results and to the available experimental data. Integral yields for some important radioisotopes were determined.

Radioiodinated MIP-1145, which specifically targets melanin, is an ideal candidate for targeted therapy of melanoma. An analogue of MIP-1145 lacking the iodo-substituent (desiodo-MIP-1145) was synthesized as a labeling precursor in three simple steps. The radioiodination of desiodo-MIP-1145 by iodine-125 was carried out via an electrophilic substitution reaction. An optimization study for the iodination reaction was carried out. The labeled compound was isolated and purified by means of electrophoresis and HPLC. The maximum radiochemical yield, 76%, was obtained with radiochemical purity greater than 99%. The log P value for [(125) I]MIP-1145 was measured as 4.5.

Nitrofurantoin (NF) was labeled with iodine-125 via electrophilic substitution reaction. Some factors affecting the radiochemical yield of 125I-NF, such as NF concentration, chloramine-T (CAT) concentration, pH of the reaction mixture, reaction time, temperature, and reaction medium, were studied. The maximum yield of 125I-NF (90%) was obtained by using 3.7 MBq of Na125I, 1 mM CAT, 1 mM NF in DMF, at pH 2 and 60 °C within 5 min. The specific activity of 125I-NF reaches 33.3 MBq/0.2 mmol, and the 125I-NF was completely separated and purified by means of high pressure liquid chromatography. The biological distribution in normal mice indicates the suitability of radioiodinated NF for urinary tract imaging. Copyright © 2012 John Wiley & Sons, Ltd.

Proton induced nuclear reactions were measured with stacked-foil technique on natural zirconium targets up to 16.7MeV. Excitation functions were measured for the production of (90,92m,95m,95g,96)Nb and (88)Y. Cumulative cross-section, thick target yields and activation functions were deduced and compared with the available experimental data, as well as with the nuclear models codes; ALICE-IPPE, EMPIRE and TALYS. The integral yields for thick targets were deduced from the measured excitation function of the produced radionuclides.

Magnetoelectric biferroic nanocomposite with composition 0.5Ni0.5Zn0.5Fe2O4 + 0.5BaTiO3 was synthesized by ceramic technique. The structural and electrical characterizations of the investigated nanocomposite are discussed and reported. The formation of nanosized composite with two separate phases was confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The variation of dielectric constant (e'), dielectric loss factor (e”) and the ac conductivity (σac) of 0.5Ni0.5Zn0.5Fe2O4 + 0.5BaTiO3 was investigated as a function of both frequency and temperature. Thermal hysteresis (first-order transition) was obtained during heating (300 - 830 K) and cooling runs (830 - 300 K). The exact transition temperature and the amount area of the thermal hysteresis depend on applied ac electric field. The delay (lagging) time between heating and cooling processes was estimated from the hysteresis loop area versus frequency. The conduction mechanism in the investigated samples was explained according to different models. This study enhances the use of this prepared system in memory applications.

This study describes a fast and efficient method for radiolabeling of etodolac with iodine-125 [125I], where both chloramine-T and iodogen were used as oxidizing agents. The labeling reaction was carried out via electrophilic substitution of hydrogen atom with the iodonium cation I+. The labeling yield was found to be influenced by different factors such as drug concentration, pH of the reaction mixtures, different oxidizing agents, reaction time, temperature and different organic media. The radiochemical yield (RCY) was determined by TLC system using methylene chloride:ethyl acetate (3:7 v/v) as a developing solvent and by electrophoresis using cellulose acetate moistened with 0.02 M phosphate buffer pH 7. The maximum radiochemical yield of [125I]Etodolac (87.7%) was obtained. Labeled etodolac shows a good localization in inflamed muscle. It excretes mainly via kidney and to some via liver.

This work assesses the potential of an adsorptive material, Dowex 50w-x8, for the separation of indium ions from cadmium ions in aqueous media. The adsorption behavior of Dowex 50 w-x8 for indium and cadmium ions was investigated. The effect of pH, initial concentration of metal ions, the weight of resins, and contact time on the sorption of each of the metal ions were determined. It was found that the adsorption percentage of the indium ions was more than 99% at pH 4.0. The result shows that In (III) was most strongly extracted, while Cd(II) was slightly extracted at this pH value. The recovery of In(III) and Cd(II) ions is around 98% using hydrochloric acid as the best eluent.

The present study is performed to compare the electrophilic substitution radioiodination reaction of two non-steroidal anti-inflammatory drugs namely, Piroxicam (Pirox) and Meloxicam (Melox) with 125I where both chloramine-T (CAT) and iodogen were used as oxidizing agents. The factors affecting the percent of radiochemical yields such as drug concentration, pH of the reaction mixtures, different oxidizing agents, reaction time, temperature and different organic media were studied to optimize the conditions for labeling of Pirox and Melox and to obtain high radiochemical yields. The maximum radiochemical yield of 125I-Piroxicam (125I-Pirox) was 94% using 3.7 MBq of Na125I, 0.4 mM of Pirox as substrate, 3.6 mM of chloramine-T (CAT) as oxidizing agent in acetone at neutral pH = 7 and at 60 °C within 20 min where the maximum radiochemical yield of 125I-Melox was 92% using 0.7 mM of Melox as substrate, 0.62 mM of iodogen as oxidizing agent in acetone at neutral pH = 7 and at 25 °C within 30 min. The radiochemical yields were determined by TLC and high-pressure liquid chromatography (HPLC). Tracers showed good localization in inflamed muscle either septic or sterile. The collected data indicates that Pirox and Melox can be used as antiinflammatory imaging agents at 24 and 2 h post injection, respectively.

A procedure for radioiodination of colchicine with iodine-125 is carried out via an electrophilic substitution reaction. The reaction parameters studied were colchicine concentration, pH of the reaction mixture, reaction time, temperature, different oxidizing agents and different organic media to optimize the conditions for the labeling of colchicine and to obtain a high radiochemical yield of the 125I-colchicine (125I-Col). Using 3.7 MBq of Na125I, 1.25 mM of colchicine as substrate, 1.1 mM of chloramine-T (CAT) as oxidizing agent in ethanol at 60°C for 5 min, a maximum radiochemical yield of 125I-Col (60%) was obtained. The specific activity of 125I-Col obtained was 44.4 MBq/0.5 mmol, and the labeled compound was not completely separated and purified from Col by means of high-pressure liquid chromatography (HPLC), so the uncertainty in the purity may affect the distribution and clearance routes due to the expected competition between 125I-Col and Col. The biological distribution in normal mice indicates the suitability of radioiodinated colchicine for imaging of muscles. Copyright © 2008 John Wiley & Sons, Ltd.

The effect of post- and pre-high doses of γ–radiation in CR-39 plastic detectors has been studied in the dose range of 3×101−106 Gy. Some properties like bulk-etch rate (V B), track-etch rate (V T), sensitivity (V T/V B) and efficiency have been found out for different gamma doses from a 60Co source in CR-39. It is found that V B and V T remain almost invariant up to gamma doses of 104 Gy. Then they start increasing slowly till 105 Gy. Between 105 Gy and 106 Gy there is a sharp increase of V B and V T values for pre- and post-gamma exposed samples. The present data are compared with the previous literature.

The ion beam of a Mather-type 23.25 J plasma focus device operated with air filling at 10 Torr was registered using CR-39 nuclear track detector. The irradiated samples were etched in NaOH solution at 70°C for 1 h. It is found here that plasm a beam contains multi-components of microbeams. The individual track density of microbeams is estimated and the total current density of the plasma stream is measured to be 1.2 mA/cm2. A model for counting the track density of individual microbeams is proposed here. Faraday cup measurements showed the ion pulse with energy ranging from 5.8 keV to 3.3 keV.

The thickness of the removed layer of the LR-115-II solid state nuclear track detector during etching is measured directly with a rather precise instrument. Dependence of bulk etching rate on temperature of the etching solution is investigated. It has been found that the bulk etching rate is 3.2 µm/h at 60°C in 2.5 N NaOH of water solution. It is also found that the track density in detectors exposed to soil samples increases linearly with the removed layer.

Thorium-to-uranium ratios have been determined in different soil samples using CR-39 and LR-115-II solid-state nuclear track detectors (SSNTDs). A calibration method based on determination of SSNTD registration sensitivity ratio for α-particles of thorium and uranium series has been developed. Thorium and uranium contents of the standard soil samples have been determined and compared with its known values. There is a good agreement between the results of this method and the values of standard samples. The method is simple, inexpensive, non-destructive and has a wide range of applications in environment, building materials and petroleum fields.

An alpha track was selected through a number of successive CR-39 sheets in a high energy nuclear reaction experiment. The experiment was aimed at identifying particles emitted at an angle of 25° to the beam direction when bombarding a copper disk with relativistic fluorine ions. Most of these particles were identified as protons and alpha particles. The experiment showed that the inlet energy of an alpha particle to be detectable in CR-39 plastic is 53.4 MeV per nucleon. The CR-39 range of such particles is ∼2 cm long. The corresponding range for a proton is ∼1 mm long. The track diameter at positions on the track length can display the damage as a function of the depth in the CR-39 material. In addition, the track length is measured along the particle trajectories in CR-39 sheets for a single track as a function of residual range in the CR-39 material. The restricted energy loss (REL) for alpha tracks in CR-39 is calculated using the Henke–Benton computer program. Comparison between the REL and the damag...

The formation of etched tracks in solid-state nuclear track detectors is usually described by assuming an unequivocal correlation of the etch-rate ratio with the energy loss of charged particles. For alpha particles, this assumption could be verified within the scatter of the experimental data. In this article, the dependence of the depth (x) on the track etch rate (V T) was determined experimentally by track length measurement. It is found that the track etch rate as a function of the depth within the detector follows the Bragg curve. The track etch rate has been found to be described by a generalization of the restricted energy loss, in good approximation along the trajectories of alpha particles.

The production of eta mesons has been measured in the proton-proton interaction close to the reaction threshold using the COSY-11 internal facility at the cooler synchrotron COSY. Total cross sections were determined for eight different excess energies in the range from 0.5 MeV to 5.4 MeV. The energy dependence of the total cross section is well described by the available phase-space volume weighted by FSI factors for the proton-proton and proton-eta pairs., Comment: 9 pages, 1 table, 5 figures

Threshold measurements of the associated strangeness production reactions pp --> pK(+)Lambda and pp --> pK(+)Sigma(0) are presented. The most remarkable feature of the data is that at the same excess energy the total cross section for the Sigma(0) production appears to be about a factor of 28(-9)(+6) smaller than for the Lambda particle. It is concluded that strong Sigma(0)p final state interactions, and in particular the Sigma N --> Lambda p conversion reaction, are the likely cause of the depletion in the Sigma signal. This hypothesis is in line with other experimental evidence in the literature.

The $pp \to pp \eta^{\prime}$ (958) reaction has been measured at COSY using the internal beam and the COSY-11 facility. The total cross sections at the four different excess energies \mbox{$ Q = ~1.5 ~MeV, ~1.7 ~MeV, ~2.9 ~MeV,$ and $ ~4.1 MeV$} have been evaluated to be \mbox{$ \sigma = 2.5 \pm 0.5~nb$, $~~~ 2.9 \pm 1.1~nb$, $~~~ 12.7 \pm 3.2~nb$, ~ and $~~~ 25.2 \pm 3.6 ~nb $}, respectively. In this region of excess energy the $\eta^{\prime}$ (958) cross sections are much lower compared to those of the $\pi ^0$ and $\eta$ production.

The energy dependence of the total cross section for the pp \to pK^+\Lambda reaction was measured in the threshold region covering the excess energy range up to 7MeV. Existing model calculations describe the slope of the measured cross sections well, but are too low by a factor of two to three in rate. The data were used for a precise determination of the beam momentum of the COSY-synchrotron.

The pp → pK+Λ reaction was measured at COSY with a proton beam momentum of 2.345 GeV/c, i.e. with an excess energy of 2 MeV above threshold. The total cross section was determined to be 8.2 ± 1.8 nb. The present data point close to the production threshold indicates, that existing phenomenological parametrizations of the total kaon production cross section are insufficient.

The COSY-11 installation is an internal experiment at the cooler synchrotron and storage ring COSY Julich. It has been designed for full geometrical acceptance close to threshold for meson production studies, especially in the 1 GeV/c2 mass range. The experimental setup makes use of a regular C-type COSY dipole magnet, following a cluster target, to separate reaction products from the beam and to analyze their momenta, thus allowing the observation of charged reaction products at small angles with beam energies close to threshold. Resonances will be identified by missing mass reconstructions from measured four-momenta of two outgoing protons in the predominantly studied pp → ppX reaction. In addition, charged mesons either produced directly or from decays of X will be detected. The different components of the experimental facility are presented.

Close-to-threshold data on the elementary kaon and antikaon production channels in the proton-proton interaction have been taken using the COSY-11 installation at the cooler synchrotron COSY Julich. The experimental technique applied at the internal COSY-11 facility—designed for meson production studies at small excess energies—is outlined. The threshold excitation functions for the kaon-hyperon production via the reactions pp→pK+Λ and pp→pK+Σ0 are presented. The magnitude of the production amplitudes is compared at equal excess energies and physical implications of the observed Σ0 suppression in the threshold region are discussed. In addition, within a Dalitz plot analysis the spin-averaged S-wave scattering parameters could be extracted for the Λ-p channel. With the possibility of detecting all final state particles the elementary antikaon production in the reaction pp→ppK+K− has been investigated. Results on the exclusive total cross section fix the scale of the strangeness dissociation into two kaons.

The experimental setup and detection technique of the COSY-11 installation, an internal experimental facility at the cooler synchrotron and storage ring COSY Julich, are described. The detection system has been designed for meson production studies with full geometrical acceptance close to threshold. Preliminary results of first measurements are presented, emphasis is put on strangeness production in the reactions pp → ppK + K − and pp → pK + Λ .