Comparison of bioassay and high performance liquid chromatographic assay of artesunate and dihydroartemisinin in plasma

The study was a comparison of bioassay and HPLC analysis of artesunate (ARTS) and dihydroartemisinin (DHA) in plasma. ARTS and DHA in plasma samples from patients treated with ARTS were quantified by HPLC and expressed as DHA. DHA-equivalents in the same plasma samples were measured using a standardised parasite culture technique. DHA concentrations estimated by both methods were highly correlated (bioassay = 0.96 x HPLC + 11.0; r(2) = 0.92). At high concentrations ( > 12 000 nmol/l) bioassay sometimes overestimated DHA. Bioassay of active drug in plasma correlates well with specific chemical analysis by HPLC. ARTS and DHA appear to account for the total antimalarial activity in plasma after ARTS administration. (C) 2003 Elsevier Science B.V. All rights reserved.

Liquidus temperatures in calcium ferrite slags in equilibrium with molten copper

Experimental laboratory methods have been developed that enable phase-equilibria studies to be carried out on slags in the system Ca-Cu-Fe-O in equilibrium with metallic copper. These techniques involve equilibration at temperature, rapid quenching, and chemical analysis of the phases using electron-probe X-ray microanalysis (EPNIA). Equilibration experiments have been carried out in the temperature range of 1150 degreesC to 1250 degreesC (1423 to 1523 K) and in the composition range of 4 to 80 wt pct "Cu2O," 0 to 25 wt pct CaO, and 20 to 75 wt pct "Fe2O3" in equilibrium with metallic copper. Liquidus and solidus data are reported for the primary-phase fields of spinel (magnetite) and dicalcium ferrite. The resulting data have been used to construct liquidus isotherms of the CaO-"Cu2O"-"Fe2O3" system at metallic copper saturation.

Phase equilibria in the ZnO-rich area of the Fe-Zn-O system in air

The phase equilibria in the Fe-Zn-O system in the range 900-1580degreesC in air have been experimentally studied using equilibration and quenching techniques. The compositions of the phases at equilibrium were determined using electron probe X-ray microanalysis (EPMA). The ferrous and ferric bulk iron concentrations were measured with a wet chemical analysis using the ammonium metavanadate technique. X-ray powder diffraction analysis (XRD) was used to characterise the phases. Iron oxide dissolved in zincite was found to be present principally in the ferric form. The XRD analysis and the composition measurements both indicate that zincite is the only phase stable in the ZnO-rich area in the range of conditions investigated. The solubility of the iron oxide in zincite rapidly increases at temperatures above 1200degreesC; the morphology of the zincite crystals also sharply changes between 1200 and 1300degreesC from rounded to plate-like crystals. The plate-like zincite forms a refractory network-the type of microstructure beneficial to the Imperial Smelting Process (ISP) sinter performance. The software program FactSage with a thermodynamically optimised database was used to predict phase equilibria in the Fe-Zn-O system.

Blanchaquinone: A new anthraquinone from an Australian Streptomyces sp.

Chemical analysis of an Australian Streptomyces species yielded a range of known anthracyclines and biosynthetically related metabolites, including daunomycin (1), E-rhodomycinone (2), 11-hydroxyauramycinone (3), 11-hydroxysulfurmycinone (4), aklavinone (5), bisanhydro-gamma-rhodomycinone (6), and the anthraquinone 7, as well as the hitherto unreported blanchaquinone (8). The structure assigned to 8 was secured by detailed spectroscopic analysis and correlation to known analogues, such as the anthraquinone 7. This account also represents the first natural occurrence of 3, 4, and 7 and the first spectroscopic characterization of 11-hydroxysulfurmycinone (4).

Phase equilibria in the Fe-Zn-O system at conditions relevant to zinc sintering and smelting

Zincite and spinel phases are present in the complex slag systems encountered in zinc/lead sintering and zinc smelting processes. These phases form extensive solid solutions and are stable over a wide range of compositions, temperatures and oxygen partial pressures. Accurate information on the stability of these phases is required in order to develop thermodynamic models of these slag systems. Phase equilibria in the Fe–Zn–O system have been experimentally studied for a range of conditions, between 900°C and 1580°C and oxygen partial pressures (pO2) between air and metallic iron saturation, using equilibration and quenching techniques. The compositions of the phases were measured using Electron probe X-ray microanalysis (EPMA). The ferrous and ferric bulk iron concentrations were determined using a specially developed wet-chemical analysis procedure based on the use of ammonium metavanadate. XRD was used to confirm phase identification. A procedure was developed to overcome the problems associated with evaporation of zinc at low pO2 values and to ensure the achievement of equilibria. An isothermal section of the system FeO–Fe2O3–ZnO at high ZnO concentrations at 1200°C was constructed. The maximum solubilities of iron and zinc in zincite and spinel phases in equilibrium were determined at pO2 = 1 × 10-6 atm at 1200°C and 1300°C. The morphology of the zincite crystals sharply changes in air between 1200–1300°C from rounded to plate-like. This is shown to be associated with significant increase in total iron concentration, the additional iron being principally in the form of ferric iron. Calculations performed by FactSage with a thermodynamically optimised database have been compared with the experimental results.

Anaerobic and aerobic metabolism of glycogen-accumulating organisms selected with propionate as the sole carbon source

In the microbial competition observed in enhanced biological phosphorus removal (EBPR) systems, an undesirable group of micro-organisms known as glycogen-accumulating organisms (GAOs) compete for carbon in the anaerobic period with the desired polyphosphate-accumulating organisms (PAOs). Some studies have suggested that a propionate carbon source provides PAOs with a competitive advantage over GAOs in EBPR systems; however, the metabolism of GAOs with this carbon source has not been previously investigated. In this study, GAOs were enriched in a laboratory-scale bioreactor with propionate as the sole carbon source, in an effort to better understand their biochemical processes. Based on comprehensive solid-, liquid- and gas-phase chemical analytical data from the bioreactor, a metabolic model was proposed for the metabolism of propionate by GAOs. The model adequately described the anaerobic stoichiometry observed through chemical analysis, and can be a valuable tool for further investigation of the competition between PAOs and GAOs, and for the optimization of the EBPR process. A group of Alphaproteobacteria dominated the biomass (96% of Bacteria) from this bioreactor, while post-fluorescence in situ hybridization (FISH) chemical staining confirmed that these Alphaproteobacteria produced poly-beta-hydroxyalkanoates (PHAs) anaerobically and utilized them aerobically, demonstrating that they were putative GAOs. Some of the Alphaproteobacteria were related to Defluvicoccus vanus (16% of Bacteria), but the specific identity of many could not be determined by FISH. Further investigation into the identity of other GAOs is necessary.

Citrinin revisited: from monomers to dimers and beyond

Detailed chemical analysis of the solid phase fermentation of an Australian Penicillium citrinum isolate has returned the known compounds citrinin (1), phenol A acid (6), dihydrocitrinone (7) and dihydrocitrinin (8), together with a novel cytotoxic dimer, dicitrinin A (5). Dicitrinin A (5) was determined to be a dimerised artefact of the major co-metabolite citrinin, and its structure solved by spectroscopic analysis and chemical modi. cation. Analysis of the products encountered during the controlled decomposition of citrinin led to the discovery of additional citrinin dimers and delineated a plausible mechanistic pathway linking all monomeric and dimeric citrinin degradation products.

Phenolic compounds in tea from Australian supermarkets

Phenolic compounds constitute 50-70% of tea water extract and are the main quality parameters for teas. Theaflavins (TF), thearubigins (TR) and theabrownins (TB) are the major polyphenols that determine the quality of black tea. These compounds were measured in 56 leaf teas and teabags sampled from Australian supermarkets in Queensland. The various quantities of TF, ranging from 0.29% to 1.25%, indicate a quality difference that exists among the teas studied. Low TF content in black tea may be due to over-fermenting and/or long periods of storage. The solubility of TR and TB from teabags ranged from 82% to 92%, indicating that the permeability of teabags was variable. Variable quantities of TF in Australian teas show instability and a tendency of TF to oxidize during storage. Total polyphenols in green teas ranged from 14% to 34%, indicating a large variation, which was not reflected in price. The solubility of total polyphenols from teabags has been proposed as a useful quality index of the filtering paper used for the teabags. This chemical analysis of phenolic compounds in commercial teas may be a potential tool for the quality control of Australian manufactured and imported teas in Australian markets. (C) 2005 Elsevier Ltd. All rights reserved.

Quinolactacins revisited: from lactams to imide and beyond

Chemical analysis of a solid phase fermentation of an Australian Penicillium citrinum strain has returned all known examples of a rare class of N-methyl quinolone lactams, quinolactacins A2 (1), B2 (2), C2 (3) and Al (4), together with the new quinolactacins B1 (5), C1 (6), D1 (7) and D2 (8), and the novel derivatives quinolonimide (9) and quinolonic acid (10). Complete stereostructures were assigned to all these compounds by detailed spectroscopic analysis and chemical interconversion. Carefully controlled and monitored decomposition studies have confirmed that quinolactacins readily undergo C-3 epimerization and oxidation, and under appropriate conditions convert to quinolonimide and quinolonic acid. Mechanisms for key transformations are proposed. The decomposition studies suggested that only quinolactacins A2 (1) and B2 (2) are genuine natural products, with all other isolated compounds being decomposition artefacts. Quinolactacins C1 (6), C2 (3), and the racemic mixture of quinolactacins D1/D2 (8/7) all displayed notable cytotoxic activity.

Secondary metabolites from the wood bark of Durio zibethinus and Durio kutejensis

Phytochemical exploration of a wood bark extract from Durio zibethinus afforded two new triterpenoids, namely, methyl 27-O-trans-caffeoylcylicodiscate (1) and methyl 27-O-cis-caffeoylcylicodiscate (2), a new phenolic, 1,2-diarylpropane-3- ol (3), and seven known compounds, fraxidin, eucryphin, boehmenan, threo-carolignan E, (-)-(3R, 4S)-4-hydroxymellein, methyl protocatechuate, and (+)-(R)-de-O-methyllasiodiplodin (4). In addition, chemical analysis of a wood bark extract from Durio kutejensis yielded the new triterpenes 3 beta-O-trans-caffeoyl-2R-hydroxyolean-12-en-28-oic acid (5) and 3 beta-trans-caffeoyl-2R-hydroxytaraxest-12-en-28-oic acid (6) together with four known compounds, maslinic acid, arjunolic acid, 2,6-dimethoxy-p-benzoquinone, and fraxidin. The structures of all compounds were determined on the basis of spectroscopic data.

Strategy-making process and firm performance in small firms

This paper argues that individual small firms just like large firms, place differing emphasis on strategy-making and may employ different modes of strategy-making. It offers a typology of the different modes of strategy-making that seem most likely to exist in small firms, and hypothesises how this typology relates to performance. It then describes the results of an empirical study of the strategy-making processes of small firms. The structural equation analysis of the data from 477 small firms with less than 100 employees indicates among other results that the simplistic, adaptive, intrapreneurial and participative modes of strategy-making exist in these small firms. Of these modes, the simplistic mode exhibits the strongest relationship with firm performance.

Dissolution, recovery and fade of Sr master alloys in Al-7Si-0.5Mg casting alloys

A number of commercial Al-Sr master alloys of differing Sr content and product form have been added to Al-7Si-0.5Mg casting alloy melts and held at constant temperature for periods up to 7 hours following the addition. The master alloys were added to achieve a specific Sr target level of 200 ppm, and the melts were held at various temperatures (most at 710ºC, but also 670, 690, 740 and 770ºC). A total of thirty six melt trials were conducted and during each trial chill-cast disc samples were taken throughout for subsequent chemical analysis. The Sr concentration versus time data of each trial has been considered in terms of Sr dissolution/recovery behaviour, as well as Sr loss/fade. Trends in the data are identified and discussed, and implications for industrial practices are suggested.

Italian wild hop (Humulus lupulus L.): from biodiversity evaluation to varietal selection

Hop (Humulus lupulus L.) is a dioecius perennial plant. The cultivation is specific for female plants, used mainly for brewing and pharmacology. Female inflorescence, known as cone or strobili, contains bitter acids, essential oil and polyphenols. Commercial hop cultivation provides better results in regions between 45 and 55 degrees north or south in latitude, an area that also includes the northern part of Italy, where hop is endemic. Despite several studies have been conducted on the characterization of wild hops biodiversity in the U.S.A. and Europe, a lack in literature concerning the description of Italian wild hops genetic variability is still present. The increasing request of hop varieties improved in important traits, like diseases, resistance and valuable aroma profile, is bringing the hop industry. Moreover, Italian agricultural sector needs new impulse to be competitive in the market. In this view, Italian wild hop biodiversity is a resource, useful for the obtaining of Italian hop varieties, characterized by peculiar aromatic traits and more adaptable to Mediterranean climate, making their cultivation more sustainable. Based on this consideration, the present Ph.D. thesis deals with the evaluation of the Italian hop biodiversity, through the characterization of the wild samples under different point of view. The project started with the recovery of wild hop samples in different areas of north of Italy to consitue a collection field, where 11 commercial cultivars of US and European origin were grown, to have a complete vision of the hop panorama. Ph.D. project followed different research lines, the results of each one contributed to completly characterize the northern Italian hop wild biodiversity: • the morphological description showed a high phenological variability (Study 1); • the genetic characterization confirmed the rich biodiversity of the Italian population and showed a significant genetic distance between Italian genotypes and the commercial cultivars, taken in consideration (Study 2); • the need of an early sex discrimination method leads to an improvement of a genetic marker, developing a more efficient marker (Study 3); • a complete morphologic, genetic and chemical analysis of plants gave results to select the most promising genotypes (Study 4); • the comparison between the performance of wild hops and commercial cultivars in the same collection field indicated that some wild genotypes had a higher environment adaptability (Study 5); • the evaluation of the terroir, obtained comparing commercial cultivars in the collection field and the same genotypes purchased in the market, showed the influence of the northern Italian environment on the aromatic profile (Study 5); • a new analytical method for the revelation of bioactive metabolites and a simple extraction procedure were developed (Study 6). In conclusion, the Ph.D. thesis, contains the first characterization of Italian wild hop, made under field condition. The present study: i) permits to obtain a complete and significative description of the genotypes; ii) allows the identification of the most promising wild Italian genotypes; iii) allows the identification of commercial cultivars more adaptable the northern Italian climate.

COACHING E MENTORING COMO PRÁTICAS DE COMPARTILHAMENTO DO CONHECIMENTO: ESTUDOS DE CASOS EM EMPRESAS PÚBLICAS PAULISTAS

A pesquisa teve como objetivo geral analisar as principais razões pelas quais as empresas públicas paulistas utilizam coaching e mentoring como práticas de compartilhamento de conhecimento. No ano de 2009, foi instituído pelo governador do Estado de São Paulo, o decreto nº 53.963 que instituiu a Política de Gestão do Conhecimento e Inovação para as empresas públicas. Kuniyoshi e Santos (2007) realizaram uma pesquisa, na qual identificaram práticas e iniciativas de gestão do conhecimento adotadas por algumas empresas, dentre elas, coaching e mentoring. As práticas são processos que necessitam de investimento não somente financeiro, mas de tempo e pessoas adequadas, por serem processos mais complexos, instigam a investigação de ações no contexto organizacional de empresas públicas. Este estudo busca contribuir para o desenvolvimento de estudos na área pública. O método utilizado neste estudo de abordagem qualitativa é do tipo exploratória. O objeto desta pesquisa foram as empresas públicas paulistas, que, atualmente, somam 21. Foi realizado estudo de caso, com entrevista e análise documental em duas destas empresas, A Sabesp, empresa do segmento de saneamento de água e esgoto, teve como objetivo analisar a prática de coaching e, o Instituto de Pesquisa Tecnológicas (IPT), referência nacional em metrologia, teve como objetivo analisar a prática de mentoring. Uma vez que não existem práticas exclusivas à Gestão do Conhecimento, e o sucesso de uma prática está relacionado ao contexto na qual está inserida. No caso da Sabesp, a prática de coaching é utilizada como uma das atividades dentro de dois programas, visando desenvolver o capital humano como força competitiva. O IPT teve como objetivo da aplicação do programa de mentoring, especificamente, o compartilhar conhecimento tácito. Foi constatado que as práticas de coaching e mentoring podem ser utilizadas como recurso capaz de tornar a empresa singular perante as demais, mesmo empresas públicas não tendo foco em competitividade, mas utilizam o conhecimento de forma estratégica para melhorar a qualidade de atendimento à sociedade.

Organizational citizenship behavior and organizational commitment in Nepal

The present study examines the structure of organizational citizenship behavior (OCB) and its relation to organizational commitment in Nepal. Four-hundred and fifty employees of five Nepalese organizations filled out standardized questionnaires. Exploratory and confirmatory factor analyses revealed two factors of OCB, altruism and compliance, replicating Western models of extra-role behavior. Structural equation analysis showed a positive relation between affective and normative commitment on the one hand and both citizenship factors on the other. Continuance commitment was negatively related to compliance and unrelated to altruism. The findings thus confirmed the structure and usefulness of the concepts in an under-researched geographical area. Findings of the research are discussed within the Nepalese sociocultural context. © Blackwell Publishing Ltd with the Asian Association of Social Psychology and the Japanese Group Dynamics Association 2005.