983 resultados para Phosphorus uptake efficiency
Resumo:
Alum-impregnated activated alumina (AIAA) was investigated in the present work as an adsorbent for the removal of As(V) from water by batch mode. Adsorption study at different pH values shows that the efficiency of AIAA is much higher than as such activated alumina and is suitable for treatment of drinking water. The adsorption isotherm experiments indicated that the uptake of As(V) increased with increasing As(V) concentration from 1 to 25 mg/l and followed Langmuir-type adsorption isotherm. Speciation diagram shows that in the pH range of 2.8–11.5, arsenate predominantly exists as H2AsO4− and HAsO42− species and hence it is presumed that these are the major species being adsorbed on the surface of AIAA. Intraparticle diffusion and kinetic studies revealed that adsorption of As(V) was due to physical adsorption as well as through intraparticle diffusion. Effect of interfering ions revealed that As(V) sorption is strongly influenced by the presence of phosphate ion. The presence of arsenic on AIAA is depicted from zeta potential measurement, scanning electron microscopy (SEM) and energy-dispersive analysis of X-ray (EDAX) mapping study. Alum-impregnated activated alumina successfully removed As(V) to below 40 ppb (within the permissible limit set by WHO) from water, when the initial concentration of As(V) is 10 mg/l.
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This thesis investigates factors that impact the energy efficiency of a mining operation. An innovative mathematical framework and solution approach are developed to model, solve and analyse an open-pit coal mine. A case study in South East Queensland is investigated to validate the approach and explore the opportunities for using it to aid long, medium and short term decision makers.
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Vampire bats, Desmodus rotundus, must maximize their feeding cycle of one blood meal per day by being efficient in the stalking and acquisition of their food. Riskin and Hermanson documented the running gait of the common vampire bat and observed they were efficient at running speeds, using longer stride lengths and thus decreased stride frequency. We obtained preliminary data on gait maintained for up to 10 minutes on a moving treadmill belt at speeds ranging from 0.23 to 0.74 m/s, which spanned a range from walking to running gaits. Bats tended to transition between gaits at about 0.40 m/s. Fourteen bats were studied and included four that were able to walk or run for 10 minutes. There was no significant change in either stride duration or frequency associated with an increase in speed. We estimated O2 consumption and CO2 production both before and 5 minutes after exercise, and found that O2 consumption increased 1 minute and 5 minutes after exercise. CO2 levels increased significantly 1 minute after exercise, but tended back towards pre-exercise level 5 minutes after exercise. Two bats were tested for blood O2, CO2 and pH levels. Interestingly, pH levels fell from 7.3 to about 7.0, indicating lactate accumulation.
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CaO-SiO2-FeOx-P2O5-MgO bearing slags are typical in the basic oxygen steelmaking (BOS) process. The partition ratio of phosphorus between slag and steel is an index of the phosphorus holding capacity of the slag, which determines the phosphorus content achievable in the finished steel. The influences of FeO concentration and basicity on the equilibrium phosphorus partition ratios were experimentally determined at temperatures of 1873 and 1923 K, for conditions of MgO saturation. The partition ratio initially increased with basicity but attained a constant value beyond basicity of 2.5. An increase in FeO concentration up to approximately 13 to 14 mass pet was beneficial for phosphorus partition.
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Complex typeN-linked oligosaccharides derived from fetuin, fibrinogen and thyroglobulin were coupled to acetyltyrosine affording a series of neoglycopeptides with retention of terminal structures and the beta-anomeric configuration of their reducing endN-acetylglycosamine residue. The neoglycopeptides thus synthesized could be labelled to high specific activities with125I in the aromatic side chain of tyrosine. Analysis of the fate of these neoglycopeptides in conjunction with inhibition with asialofetuin and oligosaccharides of defined structure in micein vivo revealed the uptake of galactosylated biantennary compound by kidneys, in addition to the known itinerary of triantennary galactosylated complex oligosaccharide from fetuin to liver and the galactosylated biantennary chain with fucosylation in the core to bone marrows. On the other hand, the agalacto, aglucosamino biantennary chains with and without fucosylation in the core region are taken up by submaxillary glands while the conserved trimannosyl core with fucose is primarily concentrated in stomach tissue. These studies thus define new routes for the uptake of complexN-linked glycans and also subserve to identify lectins presumably involved in their recognition.
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The results of the present investigation reveal that the presence of anions in the reacting medium greatly modify the reactions between soil and solution P. Associating anions reduce considerably the retention of phosphate in soils. Citrate, tartrate, and silicate are found to be superior to arsenate, oxalate, and fluoride in reducing phosphate retention in soil. The performance of associating anions depends on the pH and P concentration of the reacting medium. The nature and properties of soil also play a highly significant role on the effectiveness of associating anions.
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Suurin ongelma syöpätautien lääkehoidossa on sen aiheuttamat toksiset sivuvaikutukset. Tyypillisesti vain noin 1 % elimistöön annostellusta lääkeaineesta saavuttaa hoitoa tarvitsevat syöpäsolut, loppuosa lääkeaineesta jää vahingoittamaan elimistön terveitä soluja. Toksiset sivuvaikutukset rajoittavat lääkehoidon annoksen nostamista elimistössä riittävälle pitoisuudelle, mikä johtaa usein sairauden ennenaikaiseen pahenemiseen ja mahdollisen lääkeaineresistenssin kehittymiseen. Liposomien välittämä lääkeaineen kohdentaminen voidaan jakaa kahteen eri menetelmään: passiiviseen ja aktiiviseen kohdentamiseen. Liposomien passiivisen kohdentamisen tarkoituksena on lisätä sytotoksisen lääkeaineen paikallistumista pelkästään kasvainkudokseen. Passiivinen kohdentaminen perustuu liposomien kulkeutumiseen verenkierron mukana, jolloin liposomit kerääntyvät epänormaalisti muodostuneeseen kasvainkudokseen. Liposomien aktiivisella kohdentamisella pyritään parantamaan passiivisesti kohdentuvien liposomien terapeuttista tehokkuutta kohdentamalla lääkeaineen vaikutus pelkästään syöpäsoluihin. Aktiivisessa kohdennuksessa liposomin pintaan kiinnitetään ligandi, joka spesifisesti tunnistaa kohdesolun. Tämän pro gradu -tutkielman kirjallisen osion tarkoituksena oli tutustua syöpäkudokseen kohdennettujen liposomien ominaisuuksiin tehokkaan soluunoton ja sytotoksisuuden saavuttamiseksi. Kokeellisessa osiossa tutkittiin kohdennettujen liposomien soluunottoa ja sytotoksista vaikutusta ihmisen munasarjasta eristetyillä adenokarsinoomasoluilla (SKOV-3). Liposomit kohdennettiin setuksimabi (C225, Erbitux®) vasta-aineella, jonka on todettu olevan tietyissä syöpätyypeissä (mm. keuhko- ja kolorektaalisyövissä, pään ja kaulan syövissä sekä rinta-, munuais-, eturauhas-, haima- ja munasarjasyövissä) yli-ilmentyneen epidermaalisen kasvutekijäreseptoriperheen HER1-proteiinin (ErbB-1, EGFR, epidermal growth factor receptor) spesifinen ja selektiivinen inhibiittori. Afrikan viherapinan munuaisista lähtöisin olevaa CV-1 solulinjaa käytettiin kontrollina kuvaamaan elimistön normaaleja soluja. Kohdennettujen liposomien soluunottoa tutkittiin soluunottokokeilla, joissa käytettiin kontrollina kohdentamattomia pegyloituja liposomeja. Setuksimabi-vasta-aineen spesifinen sitoutuminen EGF-reseptoriin todettiin kilpailutuskokeilla. Doksorubisiinia sisältävien immunoliposomien sytotoksisuutta selvitettiin Alamar Blue™ -elävyystestillä. Lisäksi immunoliposomien säilyvyyttä seurattiin mittaamalla liposomien keskimääräinen halkaisija noin kahden viikon välein. Setuksimabi-vasta-aineella kohdennettujen liposomien soluunotto oli huomattavasti suurentunut SKOV-3 syöpäsoluissa ja doksorubisiinia sisältävät kohdennetut liposomit aiheuttivat voimakkaamman sytotoksisen vaikutuksen kuin kohdentamattomat liposomit. Kohdennettujen doksorubisiiniliposomien sytotoksisuus tuli kuitenkin esille viiveellä, mikä viittaa lääkeaineen hitaaseen vapautumiseen liposomista. Suurentunutta soluunottoa ja sytotoksista vaikutusta ei havaittu CV-1 solulinjassa. Kohdennettujen liposomien sovellusmahdollisuudet lääketieteessä ja syövän hoidossa ovat merkittävät. Tällä hetkellä liposomien kliininen käyttö rajoittuu passiivisesti kohdennettuihin liposomeihin (Doxil® (Am.),Caelyx® (Eur.)). Lupaavista solukokeista huolimatta kohdennettujen liposomien terapeuttinen käyttö tulevaisuudessa näyttää haasteelliselta.
Resumo:
An Arthrobacter species (tentatively identified as A. citreus), isolated by the enrichment culture method with glycerol as the sole source of carbon, was studied with a view to elucidate its pathway of glycerol breakdown. Evidence has been obtained against the functioning of the phosphorylative pathway by the study of (1) oxygen uptake with phosphorylated intermediates, (2) uptake of inorganic phosphorus by intact resting cells, (3) action of inhibitors like sodium fluoride, sodium azide, sodium arsenite, sodium iodoacetate, and parachloromercurybenzoate on oxygen uptake with resting cell suspensions and cell-free extracts in some cases. Evidence presented for the functioning of a non-phosphorylative pathway includes studies on the oxidation of glycerol, D-glyceraldehyde, glycerate, glycolic aldehyde, glycolic acid, glyoxylic acid, and formic acid to carbon dioxide and water. Further, the possibility of glyoxylate metabolism through the tricarboxylic acid cycle by its formation of malate was shown. The significance of the above pathway is that it has pointed to an alternative route of carbohydrate metabolism and entry into the tricaboxylic acid cycle without the intervention of pyruvate or the condensing enzyme.
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Administration of chloromycetin has been found to enhance the oxygen uptake of the gut of the silkworm. The possibility that this increase might have been due to a thinning of the gut wall has been ruled out since the reduction in gut weight set in much later. Although glucose ultilization by the gut has been found to be increased in vitro, increase in oxygen uptake has not been affected in the presence of glucose. The possibility of a hormonal stimulation has been discussed.
Resumo:
Administration of chloromycetin has been found to enhance the oxygen uptake of the gut of the silkworm. The possibility that this increase might have been due to a thinning of the gut wall has been ruled out since the reduction in gut weight set in much later. Although glucose ultilization by the gut has been found to be increased in vitro, increase in oxygen uptake has not been affected in the presence of glucose. The possibility of a hormonal stimulation has been discussed.
Resumo:
1. Anhydrous aluminium chloride reacts with phosphorus oxychloride to give a complex with a composition AlCl3.2 POCl3 which can be prepared in the form of a free flowing powder. 2. The phosphorus oxychloride-aluminium chloride complex in nitrobenzene dissociates into AlCl3.POCl3 and POCl3 as indicated by the cryoscopic measurements. 3. The solution of the complex in nitrobenzene has a higher specific conductivity than the corresponding electrical conductivities of individual components. Similar higher electrical conductance is observed when the two components are mixed in nitrobenzene in different proportions. 4.When a solution of anhydrous aluminium chloride in nitrobenzene is titrated conductometrically against a solution of phosphorus oxychloride in nitrobenzene, a limiting value in the conductivity is reached at point corresponding to the molecular composition, the components in the ratio of 1:2 AlCl3: POCl3 in solution. 5. The absorption maxima of the complex in nitrobenzene solution differ from the absorption maximum of the individual components.
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Tiivistelmä: Suomen jokivesien Itämereen kuljettama fosfori ja orgaaninen aine