Search

Abstract: The tandem target for a simultaneous production of [11C]CH4 and [18F]-fluoride has been designed and evaluated. A separate recovery system has been applied for a simultaneous collection of [11C]CH4 and [18F]-fluoride after a bombardment. The [11C]CH4 target was placed in front, and the [18F]-fluoride target was posted successively. An aluminum grid was employed between the two target cavities to improve the burst pressure of the titanium foil during an irradiation. It was demonstrated that a useful amount of [11C]CH4 and [18F]-fluoride can be produced simultaneously by this newly designed system. [Copyright &y& Elsevier]

A durable and ready to use 68Ge-68Ga generator column material is required for its routine use in radiopharmaceutical procedures. The present work comprises preliminary studies for development and evaluation of chitosan-TiO 2 based microsphere (C-TOM) composite towards its competence as a column material. The batch uptake studies showed higher distribution coefficients for 68Ge vis-à-vis 68Ga in the complete concentration range of HCl examined (0.01–1 mol.L−1). Furthermore, C-TOM showed enduring physical and chemical stability in 0.01 mol.L−1 HCl with persistent 68Ga elution profiles (>95%) and negligible 68Ge breakthrough (2 × 10−4%) for the preliminary evaluation period of ∼2 months. Overall, the studies indicated that, 68Ga with high radionuclidic purity (≥99.99%) can be eluted routinely in a small volume (∼1.5 mL) of 0.01 mol.L−1 HCl proving its potentials as a novel solid phase extractant for 68Ge/68Ge generator system. Image 1 • Novel approach towards synthesis of chitosan-TiO 2 microsphere (C-TOM). • Superlative physical and chemical stability of C-TOM in 0.01 M HCl. • Separation of 68Ga from 68Ge with high radionuclidic purity. • Consistent 68Ga elution profile with low 68Ge breakthrough. • Possible application of C-TOM as a potential 68Ge/68Ga generator material. [ABSTRACT FROM AUTHOR]

The 68 Ge/ 68 Ga generator system is an excellent source for producing ready-to-use Ga-68 in clinical Positron Emission Tomography (PET) applications. The column adsorbent is the key component for the 68 Ge/ 68 Ga generator system. Therefore, several studies have been conducted to identify column materials with a stable and superior elution yield in an acidic eluent (0.1 N HCl solution). In this study, four different zirconium phosphates were synthesized with a particle size of 200–800 nm, pore-size of 55∼190 Å and surface area of 0.72–268 m 2 g −1 . Synthesized and studied amorphous zirconium phosphate (ZrP-1) exhibited excellent acid resistant properties for the 0.1 N HCl eluent and a large surface area of 268 m 2 g −1 . Amorphous ZrP-1 showed a good Ga-68 elution yield of 74% in 0.1 N HCl eluent accompanying extraordinary low breakthrough of Ge-68 (0.007%). [ABSTRACT FROM AUTHOR]

A boronic acid-based fluorescent probe was developed for diagnosis of amyloid-β (Aβ) plaques from Alzheimer’s disease (AD). Probe 4c , which included boronic acid as a functional group, exhibited a significant increase (64.37-fold, F Aβ / F 0 ) in fluorescence intensity as a response to Aβ aggregates, with a blue shift (105 nm) in the maximum emission wavelength. We found that boronic acid as a functional group improved the binding affinity ( K D value = 0.79 ± 0.05 μM for 4c ) for Aβ aggregates and confirmed that 4c selectively stained Aβ plaques in brain sections from APP/PS1 mice. Ex vivo fluorescence imaging using mice (normal and APP/PS1) also revealed that 4c was able to penetrate the blood–brain barrier (BBB) and to stain Aβ plaques in the brain. From these results, we believe that 4c will be useful as a fluorescent probe in preclinical research related to AD. Furthermore, we believe that our results with boronic acid also provide valuable information for the development of a probe for Aβ plaques. [ABSTRACT FROM AUTHOR]

Abstract: Malignant melanoma displays a highly aggressive metastasis. Thus, early diagnosis of malignant melanoma is important for patient survival. We designed and synthesized a novel 68Ga-labeled benzamide derivative that specifically binds to melanoma as demonstrated by its ability to bind to melanin. 68Ga-SCN-DOTA-PCA was synthesized with a radiochemical yield of ∼80% and a radiochemical purity of >97% by analytical HPLC. The in vitro binding of 68Ga-SCN-DOTA-PCA to melanin and its cellular uptake demonstrated the selective uptake in melanin. In addition, the biodistribution and micro-PET imaging of 68Ga-SCN-DOTA-PCA in B16F10 tumor models showed the specific accumulation in melanoma. These results suggest that 68Ga-SCN-DOTA-PCA would be a promising agent for melanoma diagnosis. [Copyright &y& Elsevier]

Abstract: Radiolabeled benzamides have been reported to be attractive agents for targeting malignant melanoma as they bind melanin and display high accumulation in melanoma cells. Herein, we report the synthesis and bioevaluation of a novel 68Ga-labeled benzamide as a potential PET agent for malignant melanoma. The novel radiotracer was synthesized in good radiochemical yields (80% decay corrected yield) and high specific radioactivity (10GBq/μmol). Cellular uptake of 68Ga-SCN-NOTA-BZA was significantly higher in B16F10 cells (mouse melanoma) treated with L-tyrosine. Biodistribution and micro-PET studies of 68Ga-SCN-NOTA-BZA in B16F10-bearing mice showed selective uptake into the tumor. The radiotracer was cleared via renal excretion without further metabolism. These results demonstrate that 68Ga-SCN-NOTA-BZA is a potential PET probe for malignant melanoma. [Copyright &y& Elsevier]

Abstract: Amyloid plaques, which are primarily composed of aggregated amyloid-beta (Aβ) peptide, are the neuropathological hallmarks of Alzheimer’s disease (AD). Fluorescent markers containing 2-styrylpyridazin-3(2H)-ones were developed to detect intracellular aggregated Aβ peptides. Nine compounds exhibited a greater than 10-fold increase of in emission spectra before and after mixing with Aβ aggregates compared with before mixing. Among these compounds, compound 9n exhibited the highest affinity for Aβ aggregates (K d =1.84μM) and selectively stained both aggregated intracellular Aβ and Aβ plaques in the transgenic AD model mice (APP/PS1). These preliminary results indicate that 2-styrylpyridazin-3(2H)-one derivatives are promising alternative fluorescence imaging agent for the study of AD. [Copyright &y& Elsevier]

Abstract: α-Cobalt hydroxide is synthesized through a novel radiation-induced route using a cobalt nitrate hexahydrate isopropanol solution by irradiating 60Co γ-rays. The as-prepared product shows a layer-structured mesoporous morphology with an average size of 250 nm. Crystalline property analysis exhibits the presence α-Co(OH)2 as a predominant phase with a tiny amount of secondary phases of β-Co(OH)2 and CoO. X-ray photoelectron spectroscopy discloses the existence of Co as Co(OH)2 and CoO with a stoichiometric ratio of 76.7:23.3. In addition, the supercapacitive properties of the product are investigated using cyclic voltammetry and impedance spectroscopy in 1M KOH aqueous solution, showing a maximum capacitance value of 246.7 F g−1 at a scan rate of 5 mV s−1. [Copyright &y& Elsevier]

Abstract: Eight d-ribo-phytosphingosine derivatives were synthesized from d-ribo-phytosphingosine and diverse acyl chlorides with N,N-diisopropylethylamine in tetrahydrofuran for 1h at room temperature. Effect of these compounds on IR-induced cell death was evaluated on blood cancer cells (Jurkat). Among these, 3d showed the highest enhancement of radiosensitizing effect. [Copyright &y& Elsevier]

Abstract: Soy germ was irradiated with 2MeV electron beam with different doses ranging from 1 to 20kGy. The amount of isoflavones from irradiated soy germ was compared with those from natural soy germ by extracting with ethanol and methanol. The changed amounts of isoflavones were measured by high-performance liquid chromatography with standard calibration curve. Each extract of soy germ was quantified for antioxidant activity with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging method. The amount of isoflavones was found to be increased after electron-beam irradiation. Particularly ethanol extract with 15kGy irradiated soy germ contained the maximum amount of isoflavones. Antioxidant activity of irradiated soy germ was higher than that of natural soy germ. [Copyright &y& Elsevier]

Abstract: The aim of this research is to observe phenomena inside of a H2 18O water target during the proton beam irradiation. We made a target unit which enabled to visualize and tested it by using a 30MeV proton beam from a cyclotron at KIRAMS. In the case of a closed target system, we found that the bubbles inside of the target become smaller and dispersed over the volume as the beam intensity increases and the pressure on the water becomes higher. As a result of this study, it turned out that the target can absorb the initial proton energy completely and there arises no need to have an additional energy degradation length. It has been also found that the target has a saturation point of the irradiation current to the liquid phase due to bulging of the target windows. Consequently, RI production yield in the target depends on this value. For designing a high yield water target, suppression of the target windows and improvement of the cooling efficiency are required. [Copyright &y& Elsevier]