12 resultados para Freeze-dried
em Helda - Digital Repository of University of Helsinki
Resumo:
Cellulose can be used as a renewable raw material for energy production. The utilization requires degradation of cellulose into glucose, which can be done with the aid of enzymatic hydrolysis. In this thesis, various x-ray methods were used to characterize sub-micrometer changes in microcrystalline cellulose during enzymatic hydrolysis to clarify the process and factors slowering it. The methods included wide-angle x-ray scattering (WAXS), small-angle x-ray scattering (SAXS) and x-ray microtomography. In addition, the samples were studied with transmission electron microscopy (TEM). The studied samples were hydrolyzed by enzymes of the Trichoderma reesei species for 6, 24, and 75 hours, which corresponded to 31 %, 58 %, and 68 % degrees of hydrolysis, respectively. Freeze-dried hydrolysis residues were measured with WAXS, SAXS and microtomography, whereas some of them were re-wetted for the wet SAXS and TEM measurements. The microtomography measurements showed a clear decrease in particle size in scale of tens of micrometers. In all the TEM pictures similar cylindrical and partly ramified structures were observed, independent of the hydrolysis time. The SAXS results were ambiguous and partly imprecise, but showed a change in the structure of wet samples in scale of 10-30 nm. According to the WAXS results, the degrees of crystallinity and the crystal sizes remained the same. The gained results support the assuption, that the cellulosic particles are hydrolyzed mostly on their surface, since the enzymes are unable to penetrate into the nanopores of wet cellulose. The hydrolysis therefore proceeds quickly in easily accessible particles and leaves the unaccesible particles almost untouched. The structural changes observed in the SAXS measurements might correspond to slight loosening of the microfibril aggregates, which was seen only in the wet samples because of their different pore structure.
Resumo:
Tutkielman kirjallisuusosassa perehdyttiin vehnän, rukiin ja ohran, eli Triticeaeprolamiinien erityisasemaan keliakianäkökulmasta tarkasteltuna ja prolamiinien hydrolyysiin proliinispesifeillä entsyymeillä. Lisäksi tarkasteltiin prolamiinien immunologisia määritysmenetelmiä. Keliakiassa haitalliset gluteenipeptidit sisältävät runsaasti proliinia ja ovat hankalia pilkkoa muilla kuin proliinispesifeillä peptidaaseilla. Suurin osa immunologisen reaktion aiheuttavista gluteenilähtöisistä peptideistä voidaan pilkkoa idätetyn viljan endogeenisilla entsyymeillä happamissa olosuhteissa, mutta jäljellejäävä prolamiinipitoisuus ylittää edelleen gluteenittomille tuotteille sallitun rajan. Kokeellisen työn tavoitteena oli eliminoida happamalla mallasinkubaatiolla valmistettujen vehnä-, ohra- ja ruismallasautolysaattien sisältämä jäännösprolamiini Aspergillus niger -homeen tuottamalla proliinispesifillä endopeptidaasilla (AN-PEP) siten, että hydrolysaattia voitaisiin käyttää gluteenittomissa leivontasovelluksissa. Proteiinien hydrolyysiä tarkkailtiin kokoekskluusiokromatografialla (SEC), vapaan aminotypen (FAN) muodostumisena ja SDS-PAGE-elektroforeesilla. Jäännösprolamiinien pilkkoutumista seurattiin immunologisella R5-ELISA-menetelmällä. AN-PEP-inkubaatiolla saatiin aikaan voimakasta prolamiinien pilkkoutumista; mallasautolysaattien jäännösprolamiinista pilkkoutui yli 96 %. SEC- ja FAN-analyysien perusteella inkubaatioaikaa kannatti jatkaa yli 4 h, jolloin polypeptidit pilkkoutuivat edelleen pienemmiksi hydrolyysituotteiksi. Vehnä- ja ruismallashydrolysaattien prolamiinipitoisuuden todettiin laskevan 22 h inkubaation aikana alle tason 100 mg/kg R5-ELISA-menetelmällä määritettynä. Matalimmat prolamiinipitoisuudet saavutettiin AN-PEP-pitoisuudella 35 ?l / g mallasautolysaattia. Codex Alimentarius -komission säädöksen mukaan keliakiaruokavalioon soveltuvat ns. erittäin vähägluteeniset tuotteet saavat sisältää gluteenia enintään 100 mg/kg. Erityisesti AN-PEP-käsiteltyä ruismallasraaka-ainetta voitaisiin mahdollisesti käyttää tuomaan rukiista aromia gluteenittomiin leipiin. Ennen kuin mallashydrolysaatit ovat valmiita kaupallisiin sovelluksiin, on tarkasteltava niiden todellisia mahdollisuuksia parantaa elintarvikkeiden makua ja aromia sekä todettava uuden teknologian turvallisuus keliaakikoille.
Resumo:
Nearly one fourth of new medicinal molecules are biopharmaceutical (protein, antibody or nucleic acid derivative) based. However, the administration of these compounds is not always that straightforward due to the fragile nature of aforementioned domains in GI-tract. In addition, these molecules often exhibit poor bioavailability when administered orally. As a result, parenteral administration is commonly preferred. In addition, shelf-life of these molecules in aqueous environments is poor, unless stored in low temperatures. Another approach is to bring these molecules to anhydrous form via lyophilization resulting in enhanced stability during storage. Proteins cannot most commonly be freeze dried by themselves so some kind of excipients are nearly always necessary. Disaccharides are commonly utilized excipients in freeze-dried formulations since they provide a rigid glassy matrix to maintain the native conformation of the protein domain. They also act as "sink"-agents, which basically mean that they can absorb some moisture from the environment and still help to protect the API itself to retain its activity and therefore offer a way to robust formulation. The aim of the present study was to investigate how four amorphous disaccharides (cellobiose, melibiose, sucrose and trehalose) behave when they are brought to different relative humidity levels. At first, solutions of each disaccharide were prepared, filled into scintillation vials and freeze dried. Initial information on how the moisture induced transformations take place, the lyophilized amorphous disaccharide cakes were placed in vacuum desiccators containing different relative humidity levels for defined period, after which selected analyzing methods were utilized to further examine the occurred transformations. Affinity to crystallization, water sorption of the disaccharides, the effect of moisture on glass transition and crystallization temperature were studied. In addition FT-IR microscopy was utilized to map the moisture distribution on a piece of lyophilized cake. Observations made during the experiments backed up the data mentioned in a previous study: melibiose and trehalose were shown to be superior over sucrose and cellobiose what comes to the ability to withstand elevated humidity and temperature, and to avoid crystallization with pharmaceutically relevant moisture contents. The difference was made evident with every utilized analyzing method. In addition, melibiose showed interesting anomalies during DVS runs, which were absent with other amorphous disaccharides. Particularly fascinating was the observation made with polarized light microscope, which revealed a possible small-scale crystallization that cannot be observed with XRPD. As a result, a suggestion can safely be made that a robust formulation is most likely obtained by utilizing either melibiose or trehalose as a stabilizing agent for biopharmaceutical freeze-dried formulations. On the other hand, more experiments should be conducted to obtain more accurate information on why these disaccharides have better tolerance for elevating humidities than others.
Resumo:
This study is based on the multidiciplinary approach of using natural colorants as textile dyes. The author was interested in both the historical and traditional aspects of natural dyeing as well as the modern industrial applications of the pure natural compounds. In the study, the anthraquinone compounds were isolated as aglycones from the ectomycorrhizal fungus Dermocybe sanguinea. The endogenous beta-glucosidase of the fungus was used to catalyse the hydrolysis of the O-glycosyl linkage in emodin- and dermocybin-1-beta-D-glucopyranosides. The method, in which 10.45 kg of fresh fungi was starting material, yielded two fractions: 56.0 g of Fraction 1 (94% of the total amount of pigment,) consisting almost exclusively of the main pigments emodin and dermocybin, and 3.3 g of Fraction 2 (6%) consisting mainly of the anthraquinone carboxylic acids. The anthraquinone compounds in Fractions 1 and 2 were separated by one- and two-dimensional thin-layer-chromatography (TLC) using silica plates. 1D TLC showed that neither an acidic nor a basic solvent system alone separated completely all the anthraquinones isolated from D. sanguinea, in spite of the variation of the rations of the solvent components in the systems. Thus, a new 2D TLC technique was developed, applying n-pentanol-pyridine-methanol (6:4:3, v/v/v) and toluene-ethyl acetate-ethanol-formic acid (10:8:1:2, v/v/v/v) as eluents. Fifteen different anthraquinone derivatives were completely separated from one another. Emodin, physcion, endocrocin, dermolutein, dermorubin, 5-chlorodermorubin, emodin-1-beta-D-glucopyranoside, dermocybin-1-beta-D-glucopyranoside and dermocybin, and five new compounds, not earlier identified in D. sanguinea, 7-chloroemodin, 5,7-dichloroemodin, 5,7-dichloroendocrocin, 4-hydroxyaustrocorticone and austrocorticone, were separated and identified on the basis of their Rf-values, UV/Vis spectra and mass spectra. One substance remained unidentified, because of its very low concentration. The anthraquinones in Fractions 1 and 2 were preparatively separeted by liquid-liquid partition, with isopropylmethyl ketone and aqueous phosphate buffer as the solvent system. Advantage was taken of the principle of stepwise pH-gradient elution. The multiple liquid-liquid partition (MLLP) offered an excellent method for the preparative separation of compounds, which contain acidic groups such as the phenolic OH and COOH groups. Due to their strong aggregation properties, these compounds are, without derivatization, very difficult to separate on a preparative scale by chromatographic methods. By the MLLP method remarkable separations were achieved for the components in each mixture. Emodin and dermocybin were both obtained from Fraction 1 in a purity of at least 99%. Pure emodin and dermocybin were applied as mordant dyes to wool and polyamide and as disperse dyes to polyester and polyamide, using the high temperature (HT) technique. A mixture of dermorubin and 5-chlorodermorubin was applied as an acid dye to wool. In these experiments, synthetic dyes were used as references. Experiments were also performed using water extract of the air-dried fungi as dye liquor for wool and silk. The main colouring compounds in the crude water extract were emodin and dermocybin, which indicated that the O-glycosyl linkages in emodin- and dermocybin-1-beta-D-glucopyranosides were broken by the beta-glucosidase enzyme. Apparently, the hydrolysis occurred during the drying of the fungi and during the soaking of the dried fruit bodies overnight when preparing the dyebath. The colour of each dyed material was investigated in terms of the CIELAB L*, a* and b* values, and the colour fastness to light, washing and rubbing was tested according to the ISO standards. In the mordant dyeing experiments, emodin dyed wool and polyamide yellow and red, depending on the pH of the dyebath. Dermocybin gave purple and violet colours. The colour fastness of the mordant-dyed fabrics varied from good to moderate. The fastness properties of the natural anthraquinone carboxylic acids on wool were good, indicating the strength of the ionic bonds between the COO- groups of the dyes and the NH3+ groups of the fibres. In the disperse dyeing experiments, emodin dyed polyester bright yellow and dermocybin bright reddish-orange, and the fabrics showed excellent colour fastness. In contrast, emodin and dermocybin successfully dyed polyamide brownish-orange and wine-red, respectively, but with only moderate fastness. In industrial dyeing processes, natural anthraquinone aglycone mixtures dyed wool and silk well even at low concentrations of mordants, i.e. with 10% of the weight of the fibre (owf) of KAl(SO4)2 and 1 or 0.5% owf of other mordants. This study showed that purified natural anthraquinone compounds can produce bright hues with good colour-fastness properties in different textile materials. Natural anthraquinones have a significant potential for new dyeing techniques and will provide useful alternatives to synthetic dyes.
Resumo:
In Africa various species of Combretum, Terminalia and Pteleopsis are used in traditional medicine. Despite of this, some species of these genera have still not been studied for their biological effects to validate their traditional uses. The aim of this work has been to document the ethnomedicinal uses of several species of Combretum and Terminalia in Mbeya region, south-western Tanzania, and to use this information for finding species with good antimicrobial and cytotoxic potential. During a five weeks expedition to Tanzania in spring 1999 sixteen different species of Combretum and Terminalia, as well as Pteleopsis myrtifolia were collected from various locations in the districts of Mbeya, Iringa and Dar-es-Salaam. Traditional healers in seven different villages in the Mbeya region were interviewed in Swahili and Nyakyusa on the medicinal uses of Combretum and Terminalia species shown to them. A questionnaire was used during the interviews. The results of the interviews correlated well between different villages, the same species being used in similar ways in different villages. Of the ten species shown to the healers six were frequently used for treatment of skin diseases, bacterial infections, diarrhea, oedema and wounds. The dried plants were most commonly prepared into hot water decoctions or mixed into maize porridge, Ugali. Infusions made from dried or fresh plant material were also common. Wounds and topical infections were treated with ointments made from the dried plant material mixed with sheep fat. Twenty-one extracts of six species of Combretum and four of Terminalia, collected from Tanzania, were screened for their antibacterial effects against two gram-negative and five gram-positive bacteria, as well as the yeast, Candida albicans, using an agar diffusion method. Most of the screened plants showed substantial antimicrobial activity. A methanolic root extract of T. sambesiaca showed the most potent antibacterial effects of all the plant species screened, and gave a MIC value of 0.9 mg/ml against Enterobacter aerogenes. Also root extracts of T. sericea and T. kaiserana gave excellent antimicrobial effects, and notably a hot water extract of T. sericea was as potent as extracts of this species made from EtOH and MeOH. Thus, the traditional way of preparing T. sericea into hot water decoctions seems to extract antimicrobial compounds. Thirty-five extracts of five species of Terminalia, ten of Combretum and Pteleopsis myrtifolia were screened for their antifungal effects against five species of yeast (Candida spp.) and Cryptococcus neoformans. The species differed from each other to their antifungal effects, some being very effective whereas others showed no antifungal effects. The most effective extracts showed antifungal effects comparable to the standard antibiotics itraconazol and amphotericin B. Species of Terminalia gave in general stronger antifungal effects than those of Combretum. The best effects were obtained with methanolic root extracts of T. sambesiaca, T. sericea and T. kaiserana, and this investigation indicates that decoctions of these species might be used for treatment of HIV-related fungal infections. Twenty-seven crude extracts of eight species of Combretum, five of Terminalia and Pteleopsis myrtifolia were evaluated for their cytotoxic effects against human cancer cell lines (HeLa, cervical carcinoma; MCF 7, breast carcinoma, T 24 bladder carcinoma) and one endothelial cell line (BBCE, bovine brain capillary endothelial cells). The most outstanding effects were obtained with a leaf extract of Combretum fragrans, which nearly totally inhibited the proliferation of T 24 and HeLa cells at a concentration of 25 ug/ml and inhibited 60 % of the growth of the HeLa cells at a concentration of 4.3 ug/ml. The species of Terminalia were less cytotoxically potent than the Combretum species, although T. sericea and T. sambesiaca gave good cytotoxic effects (< 30 % proliferation). In summary this study indicates that some of the species of Terminalia, Combretum and Pteleopsis, used in Tanzanian traditional medicine, are powerful inhibitors of both microbial and cancer cell growth. In depth studies would be needed to find the active compounds behind these biological activities.
Resumo:
The Antarctic system comprises of the continent itself, Antarctica, and the ocean surrounding it, the Southern Ocean. The system has an important part in the global climate due to its size, its high latitude location and the negative radiation balance of its large ice sheets. Antarctica has also been in focus for several decades due to increased ultraviolet (UV) levels caused by stratospheric ozone depletion, and the disintegration of its ice shelves. In this study, measurements were made during three Austral summers to study the optical properties of the Antarctic system and to produce radiation information for additional modeling studies. These are related to specific phenomena found in the system. During the summer of 1997-1998, measurements of beam absorption and beam attenuation coefficients, and downwelling and upwelling irradiance were made in the Southern Ocean along a S-N transect at 6°E. The attenuation of photosynthetically active radiation (PAR) was calculated and used together with hydrographic measurements to judge whether the phytoplankton in the investigated areas of the Southern Ocean are light limited. By using the Kirk formula the diffuse attenuation coefficient was linked to the absorption and scattering coefficients. The diffuse attenuation coefficients (Kpar) for PAR were found to vary between 0.03 and 0.09 1/m. Using the values for KPAR and the definition of the Sverdrup critical depth, the studied Southern Ocean plankton systems were found not to be light limited. Variabilities in the spectral and total albedo of snow were studied in the Queen Maud Land region of Antarctica during the summers of 1999-2000 and 2000-2001. The measurement areas were the vicinity of the South African Antarctic research station SANAE 4, and a traverse near the Finnish Antarctic research station Aboa. The midday mean total albedos for snow were between 0.83, for clear skies, and 0.86, for overcast skies, at Aboa and between 0.81 and 0.83 for SANAE 4. The mean spectral albedo levels at Aboa and SANAE 4 were very close to each other. The variations in the spectral albedos were due more to differences in ambient conditions than variations in snow properties. A Monte-Carlo model was developed to study the spectral albedo and to develop a novel nondestructive method to measure the diffuse attenuation coefficient of snow. The method was based on the decay of upwelling radiation moving horizontally away from a source of downwelling light. This was assumed to have a relation to the diffuse attenuation coefficient. In the model, the attenuation coefficient obtained from the upwelling irradiance was higher than that obtained using vertical profiles of downwelling irradiance. The model results were compared to field measurements made on dry snow in Finnish Lapland and they correlated reasonably well. Low-elevation (below 1000 m) blue-ice areas may experience substantial melt-freeze cycles due to absorbed solar radiation and the small heat conductivity in the ice. A two-dimensional (x-z) model has been developed to simulate the formation and water circulation in the subsurface ponds. The model results show that for a physically reasonable parameter set the formation of liquid water within the ice can be reproduced. The results however are sensitive to the chosen parameter values, and their exact values are not well known. Vertical convection and a weak overturning circulation is generated stratifying the fluid and transporting warmer water downward, thereby causing additional melting at the base of the pond. In a 50-year integration, a global warming scenario mimicked by a decadal scale increase of 3 degrees per 100 years in air temperature, leads to a general increase in subsurface water volume. The ice did not disintegrate due to the air temperature increase after the 50 year integration.
Resumo:
The study analyses European social policy as a political project that proceeds under the guidance of the European Commission. In the name of modernisation, the project aims to build a new idea for the welfare state. To understand the project, it is necessary to distance oneself from both the juridical competence of the European Union and the traditional national welfare state models. The question is about sharing problems, as well as solutions to them: it is the creation and sharing of common views, concepts and images that play a key role in European integration. Drawing on texts and speeches produced by the European Commission, the study throws light on the development of European social policy during the first years of the 2000s. The study "freeze-frames" the welfare debate having its starting points in the nation states in the name of the entity of Europe. The first article approaches the European social model as a story in itself, a preparatory, persuasive narrative that concerns the management of change. The article shows how the audience can be motivated to work towards a set target by using discursive elements in a persuasive manner: the function of a persuasive story is to convince the target audience of the appropriateness of the chosen direction and to shape their identity so that they are favourably disposed to the desired political targets. This is a kind of "intermediate state" where the story, despite its inner contradictions and inaccuracies, succeeds in appearing as an almost self-evident path towards a modern social policy that Europe is currently seen to be in need of. The second article outlines the European social model as a question of governance. Health as a sector of social policy is detached from the old political order, which was based on the welfare state, and is closely linked to economy. At the same time the population is primarily seen as an economic resource. The Commission is working towards a "Europe of Health" that grapples with the problem of governance with the help of the "healthisation" of society, healthy citizenship and health economics. The way the Commission speaks is guided by the Union's powerful interest to act as "Europe" in the field of welfare policy. At the same time, the traditional separateness of health policy is effaced in order to be able to make health policy reforms a part of the Union's wider modernisation targets. The third article then shows the European social policy as its own area of governance. The article uses an approach based on critical discourse analysis in examining the classification systems and presentation styles adopted by Commission communications, as well as the identities that they help build. In analysing the "new start" of the Lisbon strategy from the perspective of social policy, the article shows how the emphasis has shifted from the persuasive arguments for change with necessary common European targets in the early stages of the strategy towards the implementation of reforms: from a narrative to a vision and from a diagnosis to healing. The phase of global competition represents "the modern" with which European society with its culture and ways of life now has to be matched. The Lisbon strategy is a way to direct this societal change, thus building a modern European social policy. The fourth article describes how the Commission uses its communications policy to build practices and techniques of governance and how it persuades citizens to participate in the creation of a European project of change. This also requires a new kind of agency: agents for whom accountability and responsibilities mean integration into and commitment to European society. Accountability is shaped into a decisive factor in implementing the European Union's strategy of change. As such it will displace hierarchical confrontations and emphasise common action with a view to modernising Europe. However, the Union's discourse cannot be described as being a political language that would genuinely rouse and convince the audience at the level of everyday life. Keywords: European social policy, EU policy, European social model, European Commission, modernisation of welfare, welfare state, communications, discoursiveness.
Resumo:
Microchips for use in biomolecular analysis show a lot of promise for medical diagnostics and biomedical basic research. Among the potential advantages are more sensitive and faster analyses as well as reduced cost and sample consumption. Due to scaling laws, the surface are to volume ratios of microfluidic chips is very high. Because of this, tailoring the surface properties and surface functionalization are very important technical issues for microchip development. This thesis studies two different types of functional surfaces, surfaces for open surface capillary microfluidics and surfaces for surface assisted laser desorption ionization mass spectrometry, and combinations thereof. Open surface capillary microfluidics can be used to transport and control liquid samples on easily accessible open surfaces simply based on surface forces, without any connections to pumps or electrical power sources. Capillary filling of open partially wetting grooves is shown to be possible with certain geometries, aspect ratios and contact angles, and a theoretical model is developed to identify complete channel filling domains, as well as partial filling domains. On the other hand, partially wetting surfaces with triangular microstructures can be used for achieving directional wetting, where the water droplets do not spread isotropically, but instead only spread to a predetermined sector. Furthermore, by patterning completely wetting and superhydrophobic areas on the same surface, complex droplet shapes are achieved, as the water stretches to make contact with the wetting surface, but does not enter into the superhydrophobic domains. Surfaces for surface assisted laser desorption ionization mass spectrometry are developed by applying various active thin film coatings on multiple substrates, in order to separate surface and bulk effects. Clear differences are observed between both surface and substrate layers. The best performance surfaces consisted of amorphous silicon coating and an inorganic-organic hybrid substrate, with nanopillars and nanopores. These surfaces are used for matrix-free ionization of drugs, peptides and proteins, and for some analytes, the detection limits were in the high attomoles. Microfluidics and laser desorption ionization surfaces are combined on a functionalized drying platforms, where the surface is used to control the shape of the deposited analyte droplet, and the shape of the initial analyte droplet affects the dried droplet solute deposition pattern. The deposited droplets can then directly detected by mass spectrometry. Utilizing this approach, results of analyte concentration, splitting and separation are demonstrated.
Resumo:
Viime aikoina ilmastonmuutos, fossiilisten polttoaineiden väheneminen ja niiden hinnan nousu ovat lisänneet merkittävästi maailmanlaajuista kiinnostusta uusiutuviin energiavaroihin. Suomessa uusiutuvien energialähteiden käytössä on jo pitkään panostettu metsäteollisuuden sivutuotevirtana tuottamaan puuperäiseen biomassaan, jota metsäteollisuus käyttää energiantuotantoonsa. Metsäteollisuuden jätevesien käsittelyssä syntyy erilaisia lietteitä, jotka joko uusiokäytetään tai hävitetään polttamalla tai sijoittamalla kaatopaikalle. Erityisesti biolietteiden uusiokäyttö on hankalaa ja kaatopaikkasijoitus tulevaisuudessa mahdotonta tai ainakin kustannuksiltaan kohtuutonta. Käytännössä liete hävitetään polttamalla ja kuivaamalla siitä tulee polttoaine. Lietteiden energiakäyttö on järkevin tapa hävittää jäteliete. Lietteiden korkean vesipitoisuuden vuoksi ne tulee kuitenkin kuivata ennen polttoa. Lietteen kuivaaminen sekundäärienergiavirralla eli metsäteollisuusprosesseissa sivutuotteena muodostuvalla ns. hukkalämmöllä lisää lietteen poltosta saatavaa energiamäärää ja korvaa fossiilisten polttoaineiden käyttöä. Tutkimuksen tavoitteena oli selvittää lietteen kuivaukseen optimaalisin kuoren ja lietteen seossuhde eri kuivausparametrejä vaihdellen. Kokeellinen työ aloitettiin rakentamalla energiatekniikan koehalliin laboratoriokokoluokan kiintopetikuivuri, jossa kuivumista tutkittiin puhaltamalla polttoainepedin läpi lämmitettyä ilmaa. Kuivattavina polttoaineina olivat kuoren ja lietteen seos tai pelkkä kuori ja liete erilaisilla massoilla ja erilaisilla prosenttisilla suhteilla ja erilaisissa lämpötiloissa. Kuivumiskäyrien määritys perustui massanmuutokseen. Koelaitteessa olivat anturit lämpötilan mittausta varten, jotta lämpötila saatiin säädettyä ja seurattua kokeen edellyttämällä tavalla. Lämpötilat ja painonmuutokset tallentuivat koetta tehdessä tietokoneelle. Kuivauskokeet osoittivat, että liete-kuori seos kuivuu hyvin kiintopedissä kun lietteen massaosuus seoksessa on korkeintaan 50 %. Lietteen massaosuuden ollessa tätä suurempi kuivaaminen ei enää ole tehokasta, mikä johtuu luultavasti ilman suuresta kanavoitumisesta kuivauspedissä. Kuorta kuivatessa lämpötilan nosto 50 °C:stä 70 °C:een oli huomattavasti tehokkaampaa kuin 70 °C:stä 90 °C:een, ajallisesti ero oli noin kaksinkertainen.
Resumo:
Nowadays growing number of new active pharmaceutical ingredients (API) have large molecular weight and are hydrophobic. The energy of their crystal lattice is bigger and polarity has decreased. This leads to weakened solubility and dissolution rate of the drug. These properties can be enhanced for example by amorphization. Amorphous form has the best dissolution rate in the solid state. In the amorphous form drug molecules are randomly arranged, so the energy required to dissolve molecules is lower compared to the crystalline counterpart. The disadvantage of amorphous form is that it is unstable. Amorphous form tends to crystallize. Stability of amorphous form can be enhanced by adding an adjuvant to drug product. Adjuvant is usually a polymer. Polymers prevent crystallization both by forming bonds with API molecules and by steric hindrance. The key thing in stabilizing amorphous form is good miscibility between API and polymer. They have to be mixed in a molecular level so that the polymer is able to prevent crystallization. The aim of this work was to study miscibility of drug and polymer and stability of their dispersion with different analytical methods. Amorphous dispersions were made by rotary evaporator and freeze dryer. Amorphicity was confirmed with X-ray powder diffraction (XRPD) right after preparation. Itraconazole and theophylline were the chosen molecules to be stabilized. Itraconazole was expected to be easier and theophylline more difficult to stabilize. Itraconazole was stabilized with HPMC and theophylline was stabilized with PVP. Miscibility was studied with XRPD and differential scanning calorimetry (DSC). In addition it was studied with polarized light microscope if miscibility was possible to see visually. Dispersions were kept in stressed conditions and the crystallization was analyzed with XRPD. Stability was also examined with isothermal microcalorimetry (IMC). The dispersion of itraconazole and theophylline 40/60 (w/w) was completely miscible. It was proved by linear combination of XRPD results and single glass transition temperature in DSC. Homogenic well mixed film was observed with light microscope. Phase separation was observed with other compositions. Dispersions of theophylline and PVP mixed only partly. Stability of itraconazole dispersions were better than theophylline dispersions which were mixed poorer. So miscibility was important thing considering stability. The results from isothermal microcalorimetry were similar to results from conventional stability studies. Complementary analytical methods should be used when studying miscibility so that the results are more reliable. Light microscope is one method in addition to mostly used XRPD and DSC. Analyzing light microscope photos is quite subjective but it gives an idea of miscibility. Isothermal microcalorimetry can be one option for conventional stability studies. If right conditions can be made where the crystallization is not too fast, it may be possible to predict stability with isothermal microcalorimetry.
Resumo:
Emulsiokalvolla tarkoitetaan kalvoa, joka on valmistettu haihduttamalla ylimääräinen vesi pois emulsiosta. Polysakkaridipohjainen emulsiokalvo koostuu kalvonmuodostuspolysakkaridista, rasvasta, emulgointiaineesta ja pehmittimestä. Kirjallisuusosassa selvitettiin, mitä raaka-aineita polysakkaridipohjaisissa emulsiokalvoissa käytetään ja mitkä tekijät vaikuttavat emulsiokalvojen vesihöyrynläpäisevyyteen ja mekaanisiin ominaisuuksiin. Tutkimuksen kokeellisen osan tavoitteena oli selvittää, miten konjac-glukomannaani (KGM) ja kuusen galaktoglukomannaani (GGM) soveltuvat emulsiokalvon raaka-aineiksi. Lisäksi selvitettiin, miten rasvan tyyppi ja rasvapitoisuus vaikuttavat GGM-KGM-pohjaisten emulsiokalvojen mekaanisiin ominaisuuksiin ja vesihöyrynläpäisevyyteen. Mehiläisvahasta, mäntyöljystä ja rypsiöljystä valmistettiin emulsiokalvot, joissa oli 30 %:n (paino-% GGM:sta) rasvapitoisuudet. Lisäksi mehiläisvahasta valmistettiin emulsiokalvot, joissa oli 10 ja 50 % mehiläisvahaa. Emulsiokalvoja verrattiin vertailukalvoon, jossa ei ollut rasvaa. Kalvoissa käytetty KGM:n ja GGM:n suhde oli 1:1. Kalvoista mitattiin vesihöyrynläpäisevyys ja -läpäisynopeus, vetolujuus, Youngin moduuli ja murtovenymä. Näiden lisäksi kalvojen poikkileikkaus kuvattiin pyyhkäisyelektronimikroskoopilla. GGM ja KGM soveltuvat emulsiokalvon raaka-aineiksi. Huoneenlämpötilassa kuivatuista kalvoista saatiin tasaisemman näköisiä kuin lämpökaapissa kuivatuista. Pyyhkäisyelektronimikroskooppikuvissa vahapisarat olivat öljypisaroita pienempiä, mikä mahdollisesti vaikutti siihen, että vahapisarat pysyivät paremmin kiinnittyneenä kalvomatriisissa. Öljypisaroiden koko oli kalvoissa noin 10 ?m ja vahapisaroiden 2–6 ?m. Vesihöyrynläpäisynopeus oli pienin 50 %:n mehiläisvahakalvolla (p < 0,05). Vesihöyrynläpäisevyys laski lineaarisesti mehiläisvahapitoisuuden suurentuessa. Öljykalvot ja 10 %:n mehiläisvahakalvo eivät eronneet tilastollisesti merkitsevästi vesihöyrynläpäisevyyden suhteen vertailukalvosta. Pienin vetolujuus ja Youngin moduuli oli 50 %:n mehiläisvahakalvolla. Vertailukalvo oli kestävin ja jäykin. Murtovenymän suhteen kalvot eivät eronneet toisistaan tilastollisesti merkitsevästi. Tutkimuksessa onnistuttiin valmistamaan GGM-KGM-pohjaisia emulsiokalvoja, jotka pidättivät vesihöyryä vertailukalvoa paremmin ja silti säilyttivät mekaaniset ominaisuutensa kohtuullisen hyvin.
Resumo:
Lipeä on vahva emäs, jonka on havaittu lisäävän hemiselluloosan ja ligniinin hydrolyysiä pötsissä. Näin ollen lipeäkäsittelyllä on mahdollista korvata viljan mekaaninen litistys ja jauhatus. Seosrehuruokinnalla, jonka osana on lipeäkäsitelty vilja, on mahdollista vähentää liiallisesta tärkkelyksestä aiheutuvia metabolisia ongelmia pötsissä. Tämän tutkielman tarkoituksena oli selvittää lipeäkäsitellyn vehnän vaikutusta lypsylehmien syöntiin ja tuotokseen ad libitum seosrehuruokinnoilla. Ruokinnoissa korvattiin kuivaa murskattua vehnää asteittain kokonaisella lipeäkäsitellyllä vehnällä. Kontrollina oli perinteisesti käytetty kuiva, murskattu ohra-kaura seos. Koe tehtiin Ruotsin maatalousyliopiston (SLU) maataloustieteiden laitoksella Uumajassa. Koe alkoi syyskuussa ja päättyi joulukuussa 2010. Kokeessa oli 17 useamman kerran poikinutta lehmää ja 6 ensikkoa (Ruotsin punainen -rotu). Lehmät olivat lämpimässä pihattonavetassa, jossa seosrehun syöntiä mitattiin vaakakuppien avulla. Koekäsittelyt olivat murskattu ohra-kaura seos (1:1), murskattu kuiva vehnä (1:0), murskatun kuivan vehnän ja kokonaisen lipeävehnän seos (1:1) ja kokonainen lipeävehnä (1:0). Ruokintojen kuiva-ainepitoisuudeksi asetettiin 370 g/kg ja raakavalkuaispitoisuudeksi 180 g/kg kuiva-ainetta. Näennäinen ravintoaineen sulavuus määritettiin happoon liukenemattoman tuhkan avulla. Typen hyväksikäyttöä arvioitiin laskennallisen typpitaseen avulla. Koe toteutettiin 4x4 latinalaisen neliön koemallin mukaisesti ja käsittelyjen väliset tilastolliset erot testattiin kontrastien avulla. Kuiva-aineen (PQ=0,02) ja orgaanisen aineen (PQ=0,02) syönnit lisääntyivät, samalla kun niiden sulavuudet paranivat korvattaessa puolet kuivasta vehnästä lipeävehnällä. Ruokintojen välillä ei ollut tilastollisesti merkitsevää eroa maitotuotoksessa eikä energiakorjatussa maitotuotoksessa. Maidon rasvatuotos lisääntyi vähän (PQ=0,04) ja rasvapitoisuus selvästi (PQ=0,004), kun kuivasta vehnästä korvattiin puolet lipeävehnällä. Kun kaikki kuiva vehnä korvattiin lipeävehnällä, maidon valkuaispitoisuus väheni (PL<0,001). Samoin kävi maidon ureapitoisuudelle (PL=0,002). Lipeäkäsittely ei tuottanut tässä kokeessa taloudellisesti kannattavaa tulosta, sillä maidon valkuaispitoisuus väheni ja syönti lisääntyi maitotuotoksen pysyessä samana. Vehnäruokinnoista paras tuotosvaste saatiin kuivan vehnän ja lipeävehnän seoksella.