Appl. Sci.2013, 3(4), 684-693; doi:10.3390/app3040684 - published online 4 December 2013 Show/Hide Abstract
Abstract: A series of materials was prepared by curing acrylated epoxidized soybean oil (AESO) and dibutyl itaconate (DBI) or ethyl cinnamate (EC) comonomers to provide examples of thermosets with a high proportion of bio-based carbon, in accordance with the principles of green chemistry. The comonomers, representative of cellulose-derived (DBI) or potentially lignin-derived (EC) raw materials, were tested at levels of 25%, 33%, and 50% by mass and the resulting products were characterized by infrared spectroscopy, thermogravimetric analysis, and dynamic mechanical analysis. Both DBI and EC were incorporated into the thermosets to a high extent (>90%) at all concentrations tested. The AESO-DBI and AESO-EC blends showed substantial degradation at 390–400 °C, similar to pure AESO. Glass transition temperatures decreased as comonomer content increased; the highest Tg of 41.4 °C was observed for AESO-EC (3:1) and the lowest Tg of 1.4 °C was observed for AESO-DBI (1:1). Accordingly, at 30 °C the storage modulus values were highest for AESO-EC (3:1, 37.0 MPa) and lowest for AESO-DBI (1:1, 1.5 MPa).
Appl. Sci.2013, 3(4), 675-683; doi:10.3390/app3040675 - published online 28 October 2013 Show/Hide Abstract
Abstract: As medical cyclotrons are becoming more abundant, 123I and 124I are getting more attention as alternatives to 131I for diagnostics of thyroid disease. Both 123I and 124I provide better diagnostics, deliver less dose to patients and both reduce the risk of thyroid stunning, facilitating subsequent therapy. Dry distillation of radioiodine from tellurium dioxide targets has become the standard approach to producing these radioiodines. Setting up such a production of radioiodine is associated with a lengthy optimization of the process and for this purpose natural tellurium is often used for economical reasons. In this paper, the distillation parameters are scrutinized to ensure optimal distillation temperature, in order to minimize time spent and prevent loss of expensive target material. It is further demonstrated how the individual iodine isotopes, produced from proton bombardment of natTe, will diffuse out of the target in a time dependent ratio. We believe the effect is due to the isotopes having their maximum cross section at different energies. The individual isotopes produced will thus have their highest concentration at different depths in the target. This results in individual mean diffusion lengths and diffusion times for the different isotopes.
Appl. Sci.2013, 3(4), 656-674; doi:10.3390/app3040656 - published online 25 October 2013 Show/Hide Abstract
Abstract: Magnetically recyclable nano-catalysts and their use in aqueous media is a perfect combination for the development of greener sustainable methodologies in organic synthesis. It is well established that magnetically separable nano-catalysts avoid waste of catalysts or reagents and it is possible to recover >95% of catalysts, which is again recyclable for subsequent use. Water is the ideal medium to perform the chemical reactions with magnetically recyclable nano-catalysts, as this combination adds tremendous value to the overall benign reaction process development. In this review, we highlight recent developments inthe use of water and magnetically recyclable nano-catalysts (W-MRNs) for a variety of organic reactions namely hydrogenation, condensation, oxidation, and Suzuki–Miyaura cross-coupling reactions, among others.
Appl. Sci.2013, 3(3), 636-655; doi:10.3390/app3030636 - published online 18 September 2013 Show/Hide Abstract
Abstract: A “wet chemistry” approach for isolation of 211At from an irradiated bismuth target is described. The approach involves five steps: (1) dissolution of bismuth target in conc. HNO3; (2) removal of the HNO3 by distillation; (3) dissolution of residue in 8 M HCl; (4) extraction of 211At from 8 M HCl into DIPE; and (5) extraction of 211At from DIPE into NaOH. Results from 55 “optimized” 211At isolation runs gave recovery yields of approximately 78% after decay and attenuation corrections. An attenuation-corrected average of 26 ± 3 mCi in the target provided isolated (actual) yields of 16 ± 3 mCi of 211At. A sixth step, used for purification of 211At from trace metals, was evaluated in seven runs. In those runs, isolated 211At was distilled under reductive conditions to provide an average 71 ± 8% recovery. RadioHPLC analyses of the isolated 211At solutions, both initial and after distillation, were obtained to examine the 211At species present. The primary species of 211At present was astatide, but astatate and unidentified species were also observed. Studies to determine the effect of bismuth attenuation on 211At were conducted to estimate an attenuation factor (~1.33) for adjustment of 211At readings in the bismuth target.
Appl. Sci.2013, 3(3), 624-635; doi:10.3390/app3030624 - published online 5 August 2013 Show/Hide Abstract
Abstract: The ability to detect the presence of body fluids is a crucial first step in documenting and processing forensic evidence. The Rapid Stain IDentification (RSID™) tests for blood, saliva, semen and urine are lateral flow immunochromatographic strip tests specifically designed for forensic use. Like most lateral flow strips, the membrane components of the test are enclosed in a molded plastic cassette with a sample well and an observation window. No specialized equipment is required to use these tests or to score the results seen in the observation window; however, the utility of these tests can be enhanced if an electronic record of the test results can be obtained, preferably by a small hand-held device that could be used in the field under low light conditions. Such a device should also be able to “read” the lateral flow strips and accurately record the results of the test as either positive, i.e., the body fluid was detected, or negative, i.e., the body fluid was not detected. Here we describe the RSID™ Reader System—a ruggedized strip test reader unit that allows analysis and documentation of RSID™ lateral flow strip tests using pre-configured settings, and show that the RSID™ Reader can accurately and reproducibly report and record correct results from RSID™ blood, saliva, semen, and urine tests.
Appl. Sci.2013, 3(3), 614-623; doi:10.3390/app3030614 - published online 24 July 2013 Show/Hide Abstract
Abstract: We have previously developed water-based microwave (MW)-assisted peptide synthesis using Fmoc-amino acid nanopaticles. It is an organic solvent-free, environmentally friendly method for peptide synthesis. Here we describe water-based MW-assisted solid-phase synthesis using Boc-amino acid nanoparticles. The microwave irradiation allowed rapid solid-phase reaction of nanoparticle reactants on the resin in water. We also demonstrated the syntheses of Leu-enkephalin, Tyr-Gly-Gly-Phe-Leu-OH, and difficult sequence model peptide, Val-Ala-Val-Ala-Gly-OH, using our water-based MW-assisted protocol with Boc-amino acid nanoparticles.