12 resultados para enzyme logic
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Tämän diplomityön tavoitteena oli selvittää entsyymikonvertoinnin mahdollisuudet vaikuttaa sideainetärkkelyksen toiminnallisiin ominaisuuksiin. Tärkein tehtävä oli etsiä vastaukset kysymykseen, kuinka paljon entsyymikonvertointia optimoimalla voidaan maksimoida tärkkelyksen positiivisia vaikutuksia. Tavoitteena oli myös tutkia, voiko lisäaineita käyttämällä ja tärkkelystä plastisoimalla säilyttää tärkkelyksen vaikutus paperin jäykkyyteen ja saada tärkkelysfilmille joustavuutta. Kirjallisuusosassa tarkasteltiin tärkkelyksen entsyymikonvertointiin vaikuttavia tekijöitä, eri tärkkelysraaka-aineiden eroja, sekä konvertoinnissa käytettävien entsyymien ominaisuuksia. Kirjallisuusosassa tarkasteltiin myöstärkkelyksen käyttöä sideaineena pigmenttipäällystyksessä. Kokeellisessa osassakeskityttiin selvittämään entsyymikonvertoinnin olosuhteiden, käytettävän raakatärkkelyksen ja entsyymin vaikutusta konvertoidun tärkkelyksen ominaisuuksiin. Konvertoiduista tärkkelyksistä valmistettiin päällystyspastat, ja tutkittiin niinpastan kuin päällystetyn paperin ominaisuuksia. Myös erilaisten pehmentimien vaikutusta niin päällystyspastaan, kuin paperin pinnalle tutkittiin. Havaittiin, että konvertoimalla tärkkelysketjua entsymaattisesti, voidaan tärkkelysketjun pituutta säädellä. Tarkoituksena oli konvertoida tärkkelystä niin, että tärkkelyksen molekyyliketjujakaumat sisältävät lyhyitä, keskipitkiä sekäpitkiä molekyylejä. Päällystämisen havaittiin olevan vaikeaa Helicoaterilla varsinkin pitkäketjuista tärkkelystä suuren määrän sisältävillä pastoilla. Myös tärkkelys/lateksi-suhde vaihteli eri pastoilla. Päällystyspastojen reologisia ominaisuuksia testattaessa huomattiin, että tärkkelysketjun pituuden kasvaessa pastanviskositeetti lisääntyy ja vesiretentio vähenee. Havaittiin vain muutamia teknisiä paperiominaisuuksia, jotka korreloivat hyvin tärkkelysketjun pituuden kanssa. Näitä olivat kiilto, Gurley-Hill huokoisuus, taivutusvastus, taivutuspituus sekä IGT pintalujuus. Pehmentimien ei havaittu vaikuttavan moneenkaan paperin eri tekniseen ominaisuuteen. Suurimmat erot huomattiin paperin taivutuspituudessa ja taivutusvastuksessa.
Resumo:
Tutkimuksen tavoitteena oli selvittää ohjelmistotoimialan avaintekijöitä, jotka vaikuttavat yrityksen ansaintalogiikkaan sekä lisätä tietoisuutta ansaintalogiikan muodostumisesta pienissä ja keskisuurissa ohjelmistoyrityksissä. Tutkimuksen teoreettisessa osassa keskityttiin tarkastelemaan ansaintalogiikan, strategian ja liiketoimintamallin käsitteiden suhteita sekä arvioitiin toimialan osatekijöiden, hinnoitteluperiaatteiden ja ansaintamallien vaikutusta ansainnan muodostumiseen ohjelmistotoimialalla. Ohjelmistotuote ja - palveluliiketoimintaa koskien oli merkityksellistä tutkia tuotteistamisasteen ja arvoketjujen vaikutusta ansaintalogiikan muodostumisessa sekä esitellä erilaisia, tyypillisiä ohjelmistotoimialalla käytettäviä hinnoittelumenetelmiä. Työn empiirisessä osassa tarkasteltiin 23 suomalaisen ohjelmistoalan yrityksen ansaintalogiikkaa. Tiedot kerättiin haastatteluin ja analysoitiin laadullisen tutkimuksen keinoin. Tutkimustulokset korostivat ansaintalogiikan 'epämääräisyyttä' terminä mutta osoittivat, että ydinliiketoimintaan keskittyminen, tuote-, palvelu-, tai projektiliiketoiminnan osaaminen, tuotteistusaste ja kanavavalinnat ovat avaintekijöitä ansaintalogiikanmuodostumisessa. Ansaintalogiikan muodostamiseen liittyy paljon yrityksen sisäisiä ja ulkoisia haasteita sekä muutospaineita, eikä ohjelmistotoimialalla ole todennettavissa yhtä yleismaailmallista, menestyksen takaavaa ansaintalogiikkaa.
Resumo:
Fuzzy set theory and Fuzzy logic is studied from a mathematical point of view. The main goal is to investigatecommon mathematical structures in various fuzzy logical inference systems and to establish a general mathematical basis for fuzzy logic when considered as multi-valued logic. The study is composed of six distinct publications. The first paper deals with Mattila'sLPC+Ch Calculus. THis fuzzy inference system is an attempt to introduce linguistic objects to mathematical logic without defining these objects mathematically.LPC+Ch Calculus is analyzed from algebraic point of view and it is demonstratedthat suitable factorization of the set of well formed formulae (in fact, Lindenbaum algebra) leads to a structure called ET-algebra and introduced in the beginning of the paper. On its basis, all the theorems presented by Mattila and many others can be proved in a simple way which is demonstrated in the Lemmas 1 and 2and Propositions 1-3. The conclusion critically discusses some other issues of LPC+Ch Calculus, specially that no formal semantics for it is given.In the second paper the characterization of solvability of the relational equation RoX=T, where R, X, T are fuzzy relations, X the unknown one, and o the minimum-induced composition by Sanchez, is extended to compositions induced by more general products in the general value lattice. Moreover, the procedure also applies to systemsof equations. In the third publication common features in various fuzzy logicalsystems are investigated. It turns out that adjoint couples and residuated lattices are very often present, though not always explicitly expressed. Some minor new results are also proved.The fourth study concerns Novak's paper, in which Novak introduced first-order fuzzy logic and proved, among other things, the semantico-syntactical completeness of this logic. He also demonstrated that the algebra of his logic is a generalized residuated lattice. In proving that the examination of Novak's logic can be reduced to the examination of locally finite MV-algebras.In the fifth paper a multi-valued sentential logic with values of truth in an injective MV-algebra is introduced and the axiomatizability of this logic is proved. The paper developes some ideas of Goguen and generalizes the results of Pavelka on the unit interval. Our proof for the completeness is purely algebraic. A corollary of the Completeness Theorem is that fuzzy logic on the unit interval is semantically complete if, and only if the algebra of the valuesof truth is a complete MV-algebra. The Compactness Theorem holds in our well-defined fuzzy sentential logic, while the Deduction Theorem and the Finiteness Theorem do not. Because of its generality and good-behaviour, MV-valued logic can be regarded as a mathematical basis of fuzzy reasoning. The last paper is a continuation of the fifth study. The semantics and syntax of fuzzy predicate logic with values of truth in ana injective MV-algerba are introduced, and a list of universally valid sentences is established. The system is proved to be semanticallycomplete. This proof is based on an idea utilizing some elementary properties of injective MV-algebras and MV-homomorphisms, and is purely algebraic.
Resumo:
Selostus: Angiotensiini I -muuntavaa entsyymiä estävien peptidien aminohapposekvenssien esiintyminen viljan varastoproteiinien rakenteessa
Resumo:
Cytochrome P450 (CYP) enzymes play a pivotal role in the metabolism of many drugs. Inhibition of CYP enzymes usually increases the plasma concentrations of their substrate drugs and can thus alter the safety and efficacy of these drugs. The metabolism of many widely used nonsteroidal antiinflammatory drugs (NSAIDs) as well as the metabolism of the antidepressant venlafaxine is nown to be catalyzed by CYP enzymes. In the present studies, the effect of CYP inhibition on the armacokinetics and pharmacodynamics of NSAIDs and venlafaxine was studied in clinical trials with healthy volunteers and with a crossover design, by using different antifungal agents as CYP inhibitors. The results of these studies demonstrate that the inhibition of CYP enzymes leads to increased concentrations of NSAIDs. In most cases, the exposure to ibuprofen, diclofenac, etoricoxib, and meloxicam was increased 1.5to 2 fold when they were used concomitantly with antifungal agents. CYP2D6 inhibitor, terbinafine, substantially increased the concentration of parent venlafaxine, whereas the concentration of active moiety of venlafaxine (parent drug plus active metabolite) was only slightly increased. Voriconazole, an inhibitor of the minor metabolic pathway of venlafaxine, produced only minor changes in the pharmacokinetics of venlafaxine. These studies show that an evident increase in the concentrations of NSAIDs may be expected, if they are used concomitantly with CYP inhibitors. However, as NSAIDs are generally well tolerated, use of single doses of NSAIDs concomitantly with CYP inhibitors is not likely to adversely affect patient safety, whereas clinical relevance of longterm concomitant use of NSAIDs with CYP inhibitors needs further investigation. CYP2D6 inhibitors considerably affect the pharmacokinetics of venlafaxine, but the clinical significance of this interaction remains unclear.
Resumo:
This bachelor’s thesis is a part of the research project realized in the summer 2011 in Lappeenranta University of Technology. The goal of the project was to develop an automation concept for controlling the electrically excited synchronous motor. Thesis concentrates on the implementation of the automation concept into the ABB’s AC500 programmable logic enviroment. The automation program was developed as a state machine with the ABB’s PS501 Control Builder software. For controlling the automation program is developed a fieldbus control and with CodeSys Visualization Tool a local control with control panel. The fieldbus control is done to correspond the ABB drives communication profile and the local control is implemented with a function block which feeds right control words into the statemachine. A field current control of the synchronous motor is realized as a method presented in doctoral thesis of Olli Pyrhönen (Pyrhönen 1998). The Method combines stator flux and torque based openloop control and power factor based feedback control.
Resumo:
The human body eliminates foreign compounds primarily by metabolizing them to hydrophilic forms to facilitate effective excretion through the kidneys. Cytochrome P450 (CYP) enzymes in the liver and intestine contribute to the metabolism of many drugs. Pharmacokinetic drugdrug interactions occur if the activity of CYPs are inhibited or induced by another drug. Prescribing multiple drugs to the improve effectiveness of therapy or to treat coexisting diseases is a common practice in clinical medicine. Polypharmacy predisposes patients to adverse effects because of the profound unpredictability in CYP enzymatic-mediated drug metabolism. S-ketamine is a phencyclidine derivative which functions as an antagonist of the N-methyl-Daspartate (NMDA) receptor in the central nervous system. It is a unique anaesthetic producing “dissociative anaesthesia” in high doses and analgesia in low doses. Studies with human liver microsomes suggest that ketamine is metabolized primarily via CYP3A4 and CYP2B6 enzymes. In this thesis, in healthy volunteers, randomized and controlled cross-over studies were conducted to investigate the effects of different CYP inducers and inhibitors on the pharmacokinetics and pharmacodynamics of oral and intravenous S-ketamine. The plasma concentrations of ketamine and its metabolite, norketamine, were determined at different timepoints over a 24 hour period. Other pharmacodynamic variables were examined for 12 hours. Results of these studies showed that the inhibition of the CYP3A4 pathway by clarithromycin or grapefruit juice increased the exposure to oral S-ketamine by 2.6- and 3.0-fold. Unexpectedly, CYP3A4 inhibition by itraconazole caused no significant alterations in the plasma concentrations of oral S-ketamine. CYP3A4 induction by St. John´s wort or rifampicin decreased profoundly the concentrations of oral S-ketamine. However, after rifampicin, there were no significant differences in the plasma concentrations of S-ketamine when it was administered intravenously. This demonstrated that rifampicin inhibited the metabolism of Sketamine at the intestinal level. When CYP2B6 was inhibited by ticlopidine, there was a 2.4- fold increase in the exposure of S-ketamine. These studies demonstrated that low dose oral Sketamine is metabolized both via CYP3A4 and CYP2B6 pathways. The concomitant use of drugs that affect CYP3A4 or CYP2B6, during oral S-ketamine treatment, may cause clinically significant drug-drug interactions.