No description available.

Nitric oxide (NO) has become a molecule of interest in biological research. NO is generated via the oxidation of L-arginine, by NO synthase (NOS), and plays a key role in many bioregulatory systems, including smooth muscle relaxation, platelet inhibition, neurotransmission, and immune stimulation, primarily through the formation of cGMP. N-Diazeniumdiolates (NONOates) are an interesting class of compound that can deliver NO specifically to a target site, with potential biological or therapeutic value and minimal side effects. The versatility of NONOates makes them ideal for studying NO in many different scenarios. Primary amine diazeniumdiolates such as isopropyl amine (IPA/NO) can release HNO under physiological conditions.\\Quantitative Structure Activity/Property Relationships (QSAR/QSPR) relate the structure of a compound, to a property/activity of interest ( biological activity). QSAR/QSPR studies are of great importance in drug design. Model that predict the half-lives of NONOates was built and were studied the influence of each variable on decomposition rate. External validation of this model will be made using new set of NONOates to test the Model.

No description available.

No description available.

Isoxaben is a preemergence (PRE) broadleaf herbicide used in turf and ornamentals. Field, greenhouse, and laboratory research evaluated this herbicide for PRE control of selected broadleaves in turf, suspected postemergence (POST) herbicidal effects, and the influence of application timings and rates on soil residual. During seed germination in moist filter paper, isoxaben concentrations required for 50% inhibition of radicle growth (GR50) were 0.013, 0.010, 0.008, 0.008, and 0.007 ppm for dandelion, buckhorn plantain, white clover, black medic, and common lespedeza, respectively. In greenhouse experiments, isoxaben applied POST at 2.24 kg ai/ha suppressed the growth of Florida betony, black medic and white clover by 45, 65, and 66%, respectively, and reduced regrowth of Florida betony by 71%. In soil bioassays, yellow rocket control from isoxaben applied in fall was approximately 20 and 30% greater than spring-applied isoxaben at 3 and 6 MAT, respectively. Buckhorn plantain control from fall treatments at 3 MAT was approximately 15% higher than spring-applied isoxaben at 3 MAT. Application timings did not influence control of spotted spurge, a less sensitive weed. Isoxaben applied to turf in spring at 1.12 kg/ha provided > 90% control of buckhorn plantain, dandelion, and corn speedwell at 4 MAT. Fall applied isoxaben at the same rate provided total control of common chickweed, corn speedwell and henbit at 3 MAT and 80 to 90% control of white sweet clover and buckhorn plantain that germinated the following spring. Double (spring followed by fall) application of isoxaben to turf appeared to enhance broadleaf weed control in some instances. Dissipation of isoxaben in the top 3.8 cm of a Ross silt-loam soil as affected by spring, fall, and spring followed by fall applications was determined using high performance liquid chromatography (HPLC) analysis. Isoxaben residues in soil decreased by 55 and 92% by 3 and 6 MAT, respectively, for spring teatments, and decreased 29 and 52% by 3 and 6 MAT for fall treatments, respectively. A soil-bioassay study correlated well with chemical analysis of isoxaben residues, as the correlation coefficients were 0.85 and 0.89 for yellow rocket and buckhorn plantain, respectively. / Ph. D.

Receptor-interacting protein kinase 1 (RIPK1) is a major upstream mediator of inflammation and cell death. These processes are key to common inflammatory diseases such as atherosclerosis, where macrophages play an important role in their progression. Closely linked to the expression of downstream genes, long non-coding RNAs (lncRNAs) are critical to controlling cellular processes in health and disease. As post-transcriptional regulatory mechanisms for RIPK1 are largely unknown, this project seeks to study the stability of Ripk1 mRNA and RIPK1 protein, along with Ripk1 mRNA interactions with relevant lncRNAs under various conditions. Using transcription and translation inhibitors, we determined that both Ripk1 mRNA and RIPK1 protein are relatively unstable with half-lives of approximately 3 h. Their turnover in macrophages is further influenced by the timing and duration of inflammation. We also implemented a novel RNA pull-down procedure to capture Ripk1 mRNA and attached lncRNAs for next-generation sequencing. Through differential expression analysis, we discovered significant upregulation of known lncRNA AC125611 and novel lncRNA MSTRG.5894.1 in Ripk1-targeted samples subject to inflammation. MSTRG.7477.1 was upregulated during necroptosis, while MSTRG.5684.5 was upregulated during both inflammation and necroptosis. GapmeR-mediated knockdowns of AC125611 and MSTRG.5684.5 under inflammatory conditions resulted in decreased Ripk1 mRNA expression and RIPK1 protein expression, respectively. Meanwhile, MSTRG.7477.1 knockdowns were connected to decreased RIPK1 at both the mRNA and protein levels. Our research ultimately advances the current understanding of RIPK1 regulation by focusing on Ripk1 mRNA-lncRNA associations and turnover of its mRNA and protein in macrophages, paving the way for future investigations into their capacity to act as therapeutic targets.

The occurrence of pharmaceuticals in aquatic environments originating from human consumption has received increased scientific attention during the last decades due to concerns regarding their combined environmental effects. This concerns stress the need of studies quantifying dissipation rates of pharmaceutical in aquatic ecosystems. The aims of this study were: i) to assess the degradation rates of trimethoprim (TPR), diphenhydramine (DPH), diclofenac (DCL), oxazepam (OXZ) and hydroxyzine (HDZ) in laboratory incubations, and ii) to compare laboratory assessment of dissipation rates with previously measured in situ half-lives of these drugs in a pond ecosystem. I hypothesized that the dissipation of these five drugs dissolved, in laboratory incubations, is affected by common environmental parameters such as temperature, UV-light, organic solutes and presences of sediments. In line with my hypothesis, all substances were affected by my treatments. Here, main parameters affecting the dissipation of the drugs were UV light and to a lesser temperature (i.e. through microbial degradation). All drugs were found to be affected by sediment sorption, especially HDZ where 95 % of the applied pharmaceutical was adsorbed. Laboratory estimate with highest environmental relevance (low TOC and 3 °C water temperature or low TOC, sediments and UV light) seemed to predict field estimates fairly well for all of the drugs beside OXZ and DCL. Given the strong adsorption for sediments seen in the laboratory incubations, it seems likely that the mismatch between laboratory inferred half-lives and the in situ half-lives for OXZ was likely caused by sediment exchange processes releasing drugs initially adsorbed to the sediments into water column over time.

<div>In this work new methodologies for measuring and monitoring nuclear decay parameters is explored. A determination of the tritium half-life by measuring the current of a betavoltaic device is presented. The benefits of this approach in exploring the possibility of time dependence of nuclear decay parameters is discussed.</div>

Early in the history of the field of nuclear science, experiments were performed to ascertain whether the half-lives of the radioactive substances being studied – isotopes then called the “radium emanation” [222Rn], “radium A” [218Po], “radium B” [214Pb], and “radium C” [214Bi] - were dependent upon any external factors. At that time, the external factors deemed most likely to affect half-life were temperature and pressure. After several experiments, designed to pick up any change in half-life in the course of changing temperature or pressure, had failed to find any significant changes, it was concluded that half-life does not depend on the physical properties of external environment. And that was the state of the field for a long time - for almost 100 years, in fact. Fairly recently, however, half-life measurements were recorded, and published, that seemed to show a change in half-life at the few percent level for certain radioactive nuclides which were exposed to extremes of temperature - thus challenging the long-held belief in the unchangeability of half-lives. In addition to half-life changes caused by temperature change, other experiments seemed to find half-life changes caused by other external influences, including the chemical environment of the decaying radioactive nuclide, and even the distance between Earth and the Sun at the time of the half-life measurement. In this study we present evidence that the initial beliefs in the immutability of radioactive half-life (with the exception of a few nuclides decaying by electron capture whose orbital electrons are involved in both the decay and also in the chemical bonding of those nuclides) is indeed correct; we have done this by performing precise half-life measurements on the β− emitter 198Au, the EC emitter 97Ru, and on the β− emitter 198Au when sited in gold(III) oxide, Au2O3, (an insulator for practical purposes). We have performed various experiments designed to detect any half-life change at the level of a few parts in 10^4 due to change in temperature, physical environment, or the Earth-Sun distance. In these experiments, we have found no significant half-life change due to any of these external factors. These results represent the most accurate demonstrations of the immutability of radioactive half-life change ever made.

Made available in DSpace on 2014-06-11T19:27:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-28Bitstream added on 2014-06-13T20:56:40Z : No. of bitstreams: 1 bianchini_w_dr_botfmvz.pdf: 625794 bytes, checksum: 39e58158fd9b6061d06d312f793e4743 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Este estudo buscou determinar através da utilização dos isótopos estáveis do carbono a fase em que o bezerro já está apto para ser desmamado e capaz de consumir alimentos sólidos. Para isso foram coletadas ao longo do período experimental amostras de fezes e sangue, para monitorar o comportamento do turnover do carbono em quatro bezerros bubalinos que recebiam dieta C3 em cocho privativo durante amamentação e leite proveniente de búfalas que se alimentavam de pasto C4. As análises isotópicas foram realizadas no Centro de Isótopos Estáveis do Instituto de Biociências da UNESP, campus de Botucatu. Para mensurar o turnover do carbono nos tecidos em determinado intervalo de tempo, foi utilizado o método sigmoidal de regressão de Boltzmann ou a função exponencial do tempo. Os resultados isotópicos das amostras dos animais que foram submetidos à análise por meio do modelo de Boltzmann ou equação exponencial evidenciaram a dinâmica de consumo do grupo durante os primeiros dias de vida. A meia-vida nas fezes do animal 1091 foi de 224,8 dias e no animal 1093 foi de apenas 61,2 dias, no sangue apenas no animal 1093 foi possível determinar a meia-vida, que foi de 125,6 dias e no plasma sangüíneo a meiavida do animal 1091 foi de 63,8 dias, no animal 1093 foi de 88 dias e no animal 1094 foi de 53,3 dias. Portanto, pode-se concluir que fezes não podem ser consideradas marcadores de digesta confiáveis para as condições deste estudo, apenas como indicadores de consumo. Plasma e sangue total foram eficientes em determinar o tempo de desmame para bubalinos Murrah. / This study it searched to determine through the use of stable isotopes of carbon the phase where the year-old calf already is apt to be weaned and capable to consume solid foods. For this samples of blood and faeces had been collected throughout the experimental period, to monitor the behavior of turnover of carbon in four buffaloes year-old calves that received privative C3 diet during breast-feeding and milk proceeding from buffalos that if they fed of C4 grass. The isotopic analyses had been carried through in the Steady Isotope Center of the Institute of Biociências of the UNESP, campus of Botucatu. To measure turnover of carbon in fabrics in determined time interval, the sigmoid method of regression of Boltzmann or the exponential function of the time was used. The isotopic results of the samples of the animals that had been submitted to the analysis by means of the model of Boltzmann or exponential equation had evidenced the dynamics of consumption of the group during the first days of life. The stocking-life in faeces of animal 1091 was of 224,8 days and in animal 1093 it was of only 61,2 days, in the blood only in animal 1093 was possible to determine the stocking-life, that was of 125,6 days and in the plasma sanguine the stocking-life of animal 1091 was of 63,8 days, in animal 1093 it was of 88 days and in animal 1094 it was of 53,3 days. Therefore, it can be concluded that faeces cannot be considered true markers of digestibility for the conditions of this study, as only indicating of consumption... (Complete abstract click electronic access below)