262 research outputs found

    A Multi-electrode Electrochemical and Scanning Differential Electrochemical Mass Spectrometry Study of Methanol Oxidation on Electrodeposited PtxRuy

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    Methanol electro-oxidation was studied on a series of electrodeposited PtxRuy catalysts constructed as multielement band electrodes. A combination of electrochemical and scanning differential electrochemical mass spectrometry measurements were performed to evaluate the composition-dependence of methanol oxidation, methanol decomposition, CO2 current efficiency, and the product distribution at 25 and 50 °C. At 25 °C, cyclic voltammetry revealed that the presence of Ru led to enhanced methanol oxidation rates over that of pure Pt. Methanol decomposition showed a similar composition-dependence. Mass spectrometry measurements revealed the evolution of HCOOH and CO2 during methanol oxidation and allowed indirect determination of H2CO produced. Notably, these products were not observed during methanol decomposition. The most active electrode compositions and the highest instantaneous current efficiencies for the formation of CO2 were found to depend on several factors. At 25 °C, the maximum activity was 10% Ru, while at 50 °C the most active composition increased to 25% Ru. Pure Pt had the highest instantaneous current efficiency for CO2 at both temperatures. The product distribution reflected high CO2 evolution for Pt, with an increasing fraction of the product emerging as H2CO at higher Ru content. Increasing the temperature improved the CO2 current efficiency for all electrode compositions. These results confirm that methanol oxidation occurs though a parallel reaction pathway on PtxRuy electrodes. In addition, the balance between the different reaction pathways depends on several factors, including Ru composition and temperature

    Characteristics of patients with organic brain syndromes : A cross-sectional 2-year follow-up study in Kuala Lumpur, Malaysia

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    BACKGROUND: Organic Brain Syndromes (OBS) are often missed in clinical practice. Determining their varied presentations may help in earlier detection, better management, and, assessing prognosis and outcome. We described the in-patient referrals of patients suffering from the psychiatric effects of organic states and compared the symptomatology and mortality between those with the Acute and Chronic varieties. METHODS: 59 patients referred to our Consultation-Liaison (C-L) Psychiatry services and given a clinical diagnosis of OBS were selected over a 6-month period. Psychiatric and cognitive abnormalities and treatment regimes were recorded and fatality rates determined. Information regarding their condition 24 months after their index hospitalization was recorded. All data were entered into a proforma and analyzed after exclusion. RESULTS: The mean duration of detecting the symptoms by the physician was 3.52 days. The presence of a premorbid psychiatric illness had no influence on the clinical presentation but did on the mortality of patients with OBS (p = 0.029). Patients with the Acute syndrome had significantly more symptom resolution as compared to those with the Chronic syndrome (p = 0.001) but mortalityrates did not differ. Elderly patients and those with symptom resolution upon discharge did not show statistically significant higher mortality rates. The most popular combination of treatment was that of a low-dose neuroleptic and a benzodiazepine (34.7%). The need for maintenance treatment was not significantly different in any group, even in those with a past history of a functional disorder. CONCLUSION: Other than the Acute group having a significantly better outcome in terms of symptom resolution, our findings suggest that there was no significant difference in the clinical presentation between those with Acute or Chronic OBS. Mortality-wise, there was also no difference between the Acute and Chronic syndromes, nor was there any difference between the elderly and the younger group. There was also no significant difference in the need for continued treatment in both groups

    Phylogenetic relationships in the genus Arachis based on seed protein profiles

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    Seed protein profiles of 19 accessions representing seven sections of the genus Arachis were studied using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The general profile showed appreciable homology between these taxa, supporting their classification based on morphology and cross-compatibility relationships. The accessions of section Arachis expressed a high variation confirming inferences from earlier studies. Variation between accessions of a species is limited. Accessions of the section Ambinervosae and Caulorhizae formed one cluster and accessions of sect. Erectoides and Procumbensae formed another. Whereas the representative accessions of sect. Triseminalae and Extranervosae formed two independent clusters. Using the percentage of dissimilarity in electrophoretic bands as a statistical genetic distance between accessions, sect. Arachis (containing the cultivated groundnut, A. hypogaea) is phylogenetically closest to sect. Erectoides followed by Procumbensae, Ambinervosae, Caulorhizae, Triseminalae and Extranervosae, respectively

    Polyphenols in Groundnut Genotypes Resistant and Susceptible to Seed Colonization by Aspergillus flavus

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    Thirteen groundnut genotypes, eight resistant and five susceptible to in vitro seed colonization by Aspergillus flavus were grown in replicated trials at three locations in Andhra Pradesh, India. Seed coats of these genotypes were analyzed for polyphenols using different methods. No significant correlation was observed between seed colonization and polyphenols content, which corroborates earlier observations on many genotypes using a single method for polyphenols estimation

    Dry Milling Characteristics Of Sorghum Grains And Their Relationship To Product Quality

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    Fifty-two sorghum cultivars were tested for their milling performance and to study the distribution of particle size, and starch damage after milling the grain in UDY cyclone mill, wherein varying layers of grain are progressively rubbed off against a hard surface. Cultivars showed variation in distribution of starch damage content, protein content and particle size distribution. Starch damage varied from 9.8 to 37.4%, the protein content from 7.8 to 14.8%, and the particle size from 8.4 to 19.1% in flours. Protein content was high in the coarse flour fraction while starch d1179amage was high in fine fractions. Relationships among flour particle size index (PSI), starch damage, and roti and porridge quality are reported. The potential of sorghum for use in foods such as breads and cookies through modification of milling is discussed

    Volatile Constituents of Mold-Susceptible and Mold Resistant Sorghum [Sorghum bicolor (L.) Moench] Grains

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    Headspace volatile compounds of mold-susceptible and mold-resistant sorghum [Sorghum bicolor (L.) Moench] grains were determined. The concentrations of volatile compounds in mold-susceptible sorghum were higher than those of mold-resistant sorghum. Among the 10 compounds that were identified, 2-methylbutanal was severalfold higher in the mold-susceptible sorghum than in the mold-resistant sorghum. A comparison of volatile compounds of mold-susceptible grains obtained from greenhouse-grown sorghum (mold-free) with those of field-grown sorghum indicated the possibility of a large contribution of volatile compounds from fungal organism

    Nutritional quality evaluation of newly developed high-protein genotypes of pigeonpea (Cajanus cajan)

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    Two high-protein genotypes of pigeonpea (Cajanus cajan L), HPL 8 and HPL 40, were analysed for their nutritional quality characteristics, and the results were compared with those of normal-protein genotypes (C 11 and ICPL 211). The protein content of the high-protein genotypes was higher on average by nearly 20% but their starch content, the principal constituent of the seed, was lower by about 8%. The higher fraction (about 7%) of globulin, the major storage protein, was associated with a lower glutelin fraction in the high-protein genotypes. The amino acid composition (g per 100 g protein) of the high-protein genotypes was comparable with those of the normal-protein genotypes. However, the sulphur-containing amino acids methionine and cystine were noticeably higher (about 25%) in high-protein genotypes when results were expressed in g per 100 g sample. No large differences in true protein digestibility, biological value and net protein utilisation were observed between HP and NP genotypes. True protein digestibility was significantly increased by cooking in both whole-seed and dhal samples. The values for utilisable protein were considerably higher in high-protein genotypes, suggesting their superiority from the nutritional point of view

    Nutritional Quality of Vegetable Pigeonpeas [Cajanus cajan (L.) Millsp.]: Dry Matter Accumulation, Carbohydrates and Proteins

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    Since average dry matter accumulation of green pigeonpea seeds intended for use as a vegetable was 65.6% of the total in matured seeds, green seeds were collected prior to physiological maturity. Green seed contained less starch and more dietary fiber than did mature seed. Flatulence causing oligosaccharides were present in a lower amount in green seed. Trypsin inhibitor activity (TIA) was more in mature seed whereas green and mature seed differed little in chymotrypsin inhibitor activity (CIA). The mean value for in vitro protein digestibility (IVPD) of green seed was more than that of mature seed. The green seed had a greater amount of tryptophan and threonine and the sulphur containing amino acids, methionine and cystine. It is concluded that the green seeds of pigeonpea genotypes are nutritionally better than their mature seeds

    Nutritional Quality of Vegetable Pigeonpeas [Cajanus cajan (L.) Mill sp.]: Mineral and Trace Elements

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    Mineral and trace elements of green and mature seed of pigeonpea genotypes were determined. Among the genotypes tested a considerable variation was observed in phosphorus, potassium and calcium of both green and mature seeds whereas the variation was small for magnesium. When consumed, green seeds are a richer source of iron, copper and zinc on a dry matter basis than the mature seed whereas there was a reverse trend for manganese. The calcium content of mature seed was significantly higher than green seed and this was attributed to the seed coat content of the mature seed
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