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- Author or Editor: A. Bernal x
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Abstract
This research addresses itself to the study of the mechanism of the acetic acid decarboxylation in Na-Montmorillonite exposed to ionizing radiation. The results obtained indicated that the decarboxylation reaction is enhanced several times by the irradiation. This behavior is probably due to an oxidation reaction at the edges of the clay. Also it is by energy transfer from the clay to adsorbed molecules by an interaction of non-equilibrium charge carriers with the adsorbed molecules.
Capsaicinoid and phenolic contents were determined at different maturation stages of the pepper fruit, with an increase being observed in the levels of both components. The increase in total soluble phenolics probably reflects the accumulation of capsaicinoids seen throughout development. Four different capsaicinoids and their precursor vanillylamine were identified in the cultivars studied. Capsaicin, dihydrocapsaicin and nordihydrocapsaicin showed the same accumulation patterns in all stages, but homodihydrocapsaicin appeared only in the last stage.
Abstract
Investigation on the nature of an initial mass loss observed for Mn(II)pyrrolidinedithiocarbamate complex is described. No evidences of decomposition are observed in infrared or mass spectra, elemental analysis and scanning electron microscopy of the residue at the end of the first thermal event, when compared with the same data for the original complex. Partial sublimation is assigned as the physical event after several experiments. The results are comparable with the findings for other complexes of the first transition series with pirrolidinedithiocarbamate.
Abstract
Thermally stimulated luminescence and optical absorption measurements were performed on NaCl single crystals, both single and double doped. The NaCl single crystals were exposed to gamma rays from a 60Co source at both low and room temperatures. The radiation-induced defects were mainly F and H centers, and the absorption bands for the F centers were centered at 464 nm. Bleaching with F-light showed the participation of the F center generated by gamma radiation on the TL phenomenon. The results suggest that NaCl single crystals, both single and double doped can be used as dosimeters, within certain doses.
Abstract
Electron paramagnetic resonance (EPR) was used to investigate the dosimetric properties of two pharmaceutical preparations containing acetylsalicylic acid, Aspirin® and Cafiaspirin®. The EPR spectra of the irradiated samples were found to have an asymmetric absorption characterized by a major resonance at g = 2.0033. Dose response was investigated between dose ranges of 2 to 95 kGy for 60Co-gamma rays. Fading characteristics and dependence on temperature irradiation were also studied. We suggest that commercial Aspirin® and Cafiaspirin® tablets can be used as dosimeters in the case of a short accident.
Abstract
The thermoluminescense (TL) behavior of solid solutions of cadmium and manganese doped single crystals under γ-irradiation is reported. Various compositions of single crystals of NaCl doped with Cd2+ and Mn2+ have been irradiated with ionizing radiation. The increase in the glow curve was followed as a function of the F-centers produced by the dose. The analysis shows the potential use of these materials as dosimeters.
Abstract
210Pb activities were analyzed in surface sediments from the Coatzacoalcos River (Gulf of Mexico) to evaluate its distribution according to sediment grain size and in different geochemical compartments by using sequential extraction techniques. The geochemical fractionation experiments provided compatible results: by using the Tessier’s method [<cite>1</cite>] more than 90% of the 210Pb activity in the samples was found the residual fraction (primary and secondary minerals) and the remaining (<10%) in the iron and manganese oxides fraction of the sediments; whereas using the Huerta-Diaz and Morse method [<cite>2</cite>] the 210Pb content was found in comparative amounts in the reactive, the silicate, and the pyrite fractions (accounting together for >80%), and the rest was found in the residual fraction. The grain size fractionation analyses showed that the 210Pb activities were mostly retained in the clay fraction, accounting up to 60–70% of the 210Pb total activity in the sediment sample and therefore, it is concluded that the separation of the clay fraction can be useful to improve the analysis of low 210Pb content sediments for dating purposes.
In this work it was developed marker-free transgenic indica rice plants (cv J-104) by biolistic co-transformation and segregation approach. We attempted to express the NmDef02 antifungal defensin. Primary transformants were regenerated from embryogenic callus on culture medium with 50 mg/L hygromycin. Screening of hpt-marker-free transgenic lines was made by PCR in T1 progeny lines, germinated on semisolid medium without hygromycin. Relative expression of NmDef02 mRNA was examined by quantitative RT-PCR in marker-free T1 plants. In vitro antifungal test was performed by disk diffusion assay against Sarocladium oryzae. PCR assay verified that 15.12% of T1 plants were marker-free (NmDef02+/hpt−). RT-PCR analysis indicated that NmDef02 gene was successfully transcribed and the transgenic lines displayed different expression levels of the NmDef02 cDNA. Protein extracts of marker-free lines with high relative expression of NmDef02 inhibited fungus mycelial growth around disks. In contrast, it was confirmed fungus proliferation on disks impregnated with protein extracts of non-transgenic plants. The results of the present work demonstrated that the expression of the NmDef02 defensin in transgenic rice plants is effective against the phytopathogenic fungus Sarocladium oryzae under in vitro conditions. Thus, NmDef02 defensin could be a useful tool for J-104 rice improvement.
Abstract
Background
Previous research suggests a therapeutic potential of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). However, online anecdotal reports have described a phenomenon following cessation of the acute effects of 5-MeO-DMT use which has been termed reactivation (i.e., re-experiencing [“flashback”]). To date, no research has investigated whether different routes of administration may confer different reactivation rates, effects and experiences.
Aims
We aimed to assess whether intramuscular injection (IM) and vaporization of 5-MeO-DMT conferred different reactivation rates, changes in satisfaction with life as well as ratings of the experience with ego dissolution and the mystical.
Methods
Using internet-based advertisements, 27 respondents (M age = 32. SE = 1.43; males = 18; North America = 19) completed an online-based survey.
Results
Of the 14 participants in the IM group, 3 (21%) reported reactivations; in contrast, of the 13 participants in the vaporization group, 9 (69%) reported reactivations. Redosing (more than 1 dose) occurred more frequently in the vaporization group (N = 8) (1–6 times with 3–35 mg of 5-MeO-DMT), relative to the IM group (N = 2) (1–5 times with 5–10 mg of 5-MeO-DMT). All participants in the IM group experienced release of physical tension, compared to 8 participants in the vaporization group. Participants in the IM group reported longer time of onset of acute effects (between 1 and 3 [N = 6] and 4–6 min [N = 6]), relative to the vaporization group where the majority (N = 11) reported a rapid onset of 1–50 s.
Conclusion
Findings suggest that compared to vaporization, the IM route of administering 5-MeO-DMT is associated with lower and less doses, lower frequencies of reporting reactivation, a higher frequency of physical tension release, and a slower onset of acute effects.
