The UV/H2O2 - photodegradation of poly(ethyleneglycol) and model compounds

The general mechanism for the photodegradation of polyethyleneglycol (PEG) by H2O2/UV was determined studying the photooxidation of small model molecules, like low molecular weight ethyleneglycols (tetra-, tri-, di-, and ethyleneglycol). After 30 min of irradiation the average molar mass (Mw) of the degradated PEG, analysed by GPC, fall to half of its initial value, with a concomitant increase in polydispersitivity and number of average chain scission (S), characterizing a random chain scission process yielding oligomers and smaller size ethyleneglycols. HPLC analysis of the photodegradation of the model ethyleneglycols proved that the oxidation mechanism involved consecutive reactions, where the larger ethyleneglycols gave rise, successively, to smaller ones. The photodegradation of ethyleneglycol lead to the formation of low molecular weight carboxylic acids, like glycolic, oxalic and formic acids.O mecanismo geral para a fotodegradação do polietilenoglicol (PEG) usando o sistema H2O2/UV foi determinado por GPC e HPLC, analisando o comportamento de moléculas modelo, como por exemplo os etilenoglicóis de baixa massa molar (tetra-, tri-, di-, e etilenoglicol). Após 30 min de irradiação, a massa molar ponderal média (Mw) do PEG degradado, analisada por GPC, cai para metade do seu valor inicial com um aumento concomitante na polidispersidade e número médio de quebra de cadeia (S). Essa queda acentuada caracteriza uma quebra de cadeia aleatória, formando oligômeros e etilenoglicóis de menor massa molar. A análise da fotodegradação de etilenoglicóis modelo por HPLC permitiu sugerir um mecanismo que envolve processos consecutivos, em que etilenoglicóis maiores originam menores, sucessivamente. A fotodegradação do etilenoglicol formou ácidos carboxílicos de baixa massa molar, como por exemplo os ácidos glicólico, oxálico e fórmico.FAPESPCNP

Towards a clinical staging for bipolar disorder: defining patient subtypes based on functional outcome.

BACKGROUND: The functional outcome of Bipolar Disorder (BD) is highly variable. This variability has been attributed to multiple demographic, clinical and cognitive factors. The critical next step is to identify combinations of predictors that can be used to specify prognostic subtypes, thus providing a basis for a staging classification in BD. METHODS: Latent Class Analysis was applied to multiple predictors of functional outcome in a sample of 106 remitted adults with BD. RESULTS: We identified two subtypes of patients presenting "good" (n=50; 47.6%) and "poor" (n=56; 52.4%) outcome. Episode density, level of residual depressive symptoms, estimated verbal intelligence and inhibitory control emerged as the most significant predictors of subtype membership at the p<0.05 level. Their odds ratio (OR) and confidence interval (CI) with reference to the "good" outcome group were: episode density (OR=4.622, CI 1.592-13.418), level of residual depressive symptoms (OR=1.543, CI 1.210-1.969), estimated verbal intelligence (OR=0.969; CI 0.945-0.995), and inhibitory control (OR=0.771, CI 0.656-0.907). Age, age of onset and duration of illness were comparable between prognostic groups. LIMITATIONS: The longitudinal stability or evolution of the subtypes was not tested. CONCLUSIONS: Our findings provide the first empirically derived staging classification of BD based on two underlying dimensions, one for illness severity and another for cognitive function. This approach can be further developed by expanding the dimensions included and testing the reproducibility and prospective prognostic value of the emerging classes. Developing a disease staging system for BD will allow individualised treatment planning for patients and selection of more homogeneous patient groups for research purposes

Gambaran Histopatologik Lambung Tikus Wistar (Rattus Norvegicus) Yang Diberikan Air Perasan Jeruk Nipis (Citrus Aurantifolia)

: Lime squash is often used as a herbal remedy for gastritis, even though it is acidic. It contains citric acid and vitamin C which in certain doses can be irritant to the stomach. Nevertheless, lime squash also contains antioxidants such as limonene, flavonoids, and vitamin C, that play certain roles in improving the protection of the stomach and the ability of cell regeneration, and as anti-inflammatory agents. This study aimed to reveal the histopathological features of the gaster of Wistar rats (Rattus norvegicus) treated with lime squash. This was an experimental laboratory study using 15 adult Wistar rats divided into three groups (five rats in each group). Group A (negative control) was given no treatment; group B and C were treated with lime squash 0.5 and 1.56 ml/day, respectively. Lime squash was given in a single dose for seven consecutive days. Rats were terminated on day eight. The results revealed that the gaster of Wistar rats in group A were similar to that of the normal gaster, while group B and C showed no signs of inflammation and the gastric gland cells appeared enlarged and dense. Conclusion: Histopathological features of the gaster of Wistar rats, treated with either low or high dose (three-fold) lime squash, showed no signs of abnormalities such as inflammation, however, there were enlarged glandular cells which might be related to increased gastric mucosal defence

Mutual diffusivity in n-Heptane + n-Hexane isomers

A preliminary study of the effect of branching in the binary diffusion of hexane isomer + n-heptane systems is presented. Measurements have been performed with an instrument modeled for the Taylor dispersion technique, at several compositions, at 297 K, for the n-hexane + n-heptane and 2,2-dimethylbutane + n-heptane binary mixtures. The accuracy is estimated to be 1%. The influence of branching is discussed. It was found that the rough hard sphere model for binary diffusion can reproduce the experimental data within 6%. This model was used to predict the binary diffusion coefficients in the 2-methylpentane + n-heptane and 3-methylpentane + n-heptane mixtures, with an estimated accuracy of 5%

Gambaran Histopatologik Hati Tikus Wistar Yang Diberi Ekstrak Daun Kelor (Moringa Oleifera) Setelah Diinduksi Karbon Tetraklorida (CCl4)

: Moringa (Moringa oleifera) is a traditional plant, which is known to treat liver disease. The effect of moringa is related to the antioxidant activity of its compounds such as quercetin and flavonoid silymarin which are useful as liver protector. Carbon tetraclorida is a hepatotoxic substance that is usually used as an inducer of liver damage in studies related to hepatoprotector activity of a substance. This study aimed to describe liver histopathological features of Wistar rats fed with moringa leaf extract after CCl4 induction. This was an experimental study using 24 Wistar rats (Rattus norvegicus) which were divided into 4 groups. Group A, the negative control, was terminated at day 6th, and the other groups (B, C, and D) were induced with CCl4 0.05 cc/day for 5 days. After CCl4 induction, group B were terminated at day 6th; group C was treated with moringa leaf extract 100 mg/day for 5 days and was terminated at day 11th; group D received no treatment for 5 days and was terminated at day 11th. The results showed that groups induced with CCl4 for 5 days showed the presence of inflammatory cells and fatty cells. The groups treated with moringa leaf extract 100mg/day for 5 days after CCl4 induction 0.05 cc/day exhibited regeneration of liver cells in nearly all lobules. Conclusion: Administration of moringa leaf extract of 100mg/day could accelerate liver cell regeneration of Wistar rats after induction of CCl4 0.05cc/day