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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Korrelation mellan fenolröd tråd och Schirmers tårtest : En litteraturstudie

Olsson, Malin, Sjösvärd, Richard January 2020 (has links)
Syfte: Att genom en litteraturstudie jämföra Schirmers tårtest (STT) och fenolröd tråd (PRTT), för att se hur god korrelation det är mellan de två testerna vid diagnostisering av torra ögon. Metod: Analysera och jämföra studier med hjälp av olika artiklar. Dessa artiklar har hittats genom sökning i databasen Google scholar med sökfraserna schirmer´s test versus phenol red thread och tear test correlations. Fem relevanta artiklar valdes ut för närmare granskning. Resultat: Det har framkommit varierande resultat angående huruvida det finns en god korrelation mellan Schirmers tårtest och fenolröd tråd. Slutsats: Efter att ha tittat närmare på de fem studierna så kan man konstatera att det behövs ytterligare studier av testerna Schirmers tårtest och fenolröd tråd, dessutom behövs det gemensamma gränser för vad som är torra ögon. När det gäller korrelationen mellan Schirmers tårtest och fenolröd tråd så är det svårt att ta ställning till det eftersom alla studier har olika urvalskriterier. / Objective: This literature review is a comparison of the Schirmer's tear test (STT) and the Phenol Red Thread Test (PRTT). The aim of the review is to find out if there was a good correlation between the two tests regarding diagnosing dry eye disease. Method: Analyze and compare studies using different articles. These articles were found by searching the Google Scholar. The search phrases were Schirmer´s test versus phenol red thread and tear test correlations. Five relevant articles were selected for further review. Results: There have been varying results regarding whether there is a good correlation between Schirmer's tear test and Phenol Red Thread. Conclusion: After a closer look at the five studies, it can be concluded that further studies of the Schirmer's tear test and Phenol Red Thread are required, in addition, there is a need of common cutoffs for diagnosing dry eye disease. It is hard to find a correlation between Schirmer's tear test and Phenol Red Thread, since all studies use different criteria for inclusion.
232

Chování lubrikační emulze a pryskyřice ve výrobě minerální plsti / Mineral wool and binding agent interaction and behavior study

Fiala, Michal January 2010 (has links)
Diploma's thesis describes resolution of cause technological problems in mineral wool manufacturig in company Saint-Gobain Orsil. Main attention is paid to thermal and volatile process in mineral wool from filtration chamber and common commercial sales. Samples of mineral wool were characterizated by thermal analysis (simultaneous TG-DTA), effluent gas analysis (EGA), infrared spectroscopy (FT-IR), electron microscopy (SEM) and X-ray diffraction (XRD). Thermal analysis experiments was used to check thermal volatile processes. Technological problem of burning is linked with rise of isocyanic acid.
233

Manufacturing of Mechanical Supporting Foamed Sheets by Processing Free Flowing Phenolic Molding Compounds via Foam Extrusion

Methe, Daniel 19 December 2019 (has links)
Manufacturing of Mechanical Supporting Foamed Sheets by processing Free Flowing Phenolic Molding Compounds with the Foam Extrusion and its Characterization
234

Vliv terminace povrchu borem dopované diamantové elektrody na elektrochemické chování fenolu a jeho derivátů / Influence of surface termination of boron-doped diamond electrode on the electrochemical behaviour of phenol and its derivatives

Nedvěd, Michal January 2020 (has links)
This thesis is devoted to the study of electrochemical oxidation of meta-substituted phenolic substances on a boron-doped diamond electrode. In the first phase, it was studied the effect of pH on their electrochemical oxidation by the methods of classical "direct current" voltammetry (DCV) and differential pulse voltammetry (DPV). The study was performed on three types of boron doped diamond (BDD) surfaces: polished, anodic and cathodically activated. In the second phase, attention was paid to the Hammett correlation to study the effect of the substituent on the potential of electrochemical oxidation of selected phenolic compounds. Among the substituents studied were (-H, -CH3, -OCH3, -(CH2)2COOH, -COOH a -NO2). In general, the oxidation potentials were lower in the basic medium than in the acidic medium on all studied surfaces. An exception was the studied phenolic acids, which could not be detected in an alkaline medium on the O-terminated BDD, probably due to electrostatic repulsion between the partially negative electrode surface and the acid dianion. The highest correlation coefficient for the dependence composed of all studied phenols was obtained for the polished and H-terminated surface at pH 11, ie the dissociated form of phenolic substances. The high electron density leads to easy...
235

Detection of Entamoeba histolytica using colorimetric loop-mediated isothermal amplification (LAMP)

Blom, Matilda January 2022 (has links)
Amoebic dysenteri is a problem in developing countries and is caused by Entamoeba histolytica (E. histolytica) with symptoms such as diarrhea, vomiting and in worse case extra intestinal manifestation. Currently there are difficulties to diagnose E. histolytica infections in developing countries because PCR requires advanced and expensive and microscopy cannot distinguish E. histolytica from other harmless species of amoebas. The aim of this study was therefore to develop loop-mediated isothermal amplification (LAMP), which is similar to PCR but is performed at a single temperature and amplifies the target gene in less than an hour. LAMP was also compared to real time PCR. With a commercial kit, DNA were extracted from cultivated trophozoites and for the LAMP reaction, a colorimetric mastermix and six primers were used designed from 18S small subunit ribosomal RNA gene. With phenol red positive LAMP reactions showed a color change from pink to yellow and negative LAMP reactions remained pink. The sensitivity of LAMP for detection of E. histolytica was determined to be 80 pg/µl, which was ten times less sensitive than real time-PCR. The method was also shown to work on trophozoites with no DNA extraction and no non-specific amplifications were seen with DNA from G. lamblia, which showed some specificity. LAMP proved to be sensitive and easy to work with, but requires tightly closed tubes to avoid contamination and false positive results. To develop and evaluate the method LAMP for detection of E. histolytica, more studies are needed, including clinical samples and optimization.
236

Polyphenol intake by food group in the ulcerative colitis population

Kleinman, Joshua 19 June 2019 (has links)
No description available.
237

Bastutinių šeimos piktžolių alelopatinių savybių palyginimas / The comparison of allelopathic properties of Brassicaceae family weeds

Eimutytė, Edita 16 June 2014 (has links)
Tyrimų objektas – dirvinis garstukas (Sinapis arvensis L.), dirvinė čiužutė (Thlaspi arvense L.), smalkinis tvertikas (Erysimum cheiranthoides L.), trikertė žvaginė (Capsella bursa-pastoris (L.) Medik.). Tyrimų tikslas ir metodai – nustatyti ir palyginti bastutinių šeimos piktžolių alelopatinę įtaką žemės ūkio augalams. Bendrasis fenolinių junginių kiekis buvo nustatytas pagal (Ragaee et al., 2006) metodiką. Praskiedimo būdu paruoštos vandeninės ištraukos: 1:6250, 1:1250, 1:250 ir 1:50 koncentracijų (Гродзинский, 1965; Lazauskas, 1990). Žieminių ir vasarinių rapsų sėklos bei žieminių kviečių ir vasarinių miežių grūdai buvo daiginami keturias paras ant filtrinio popieriaus, sudrėkinto paruoštų koncentracijų vandeninėmis ištraukomis, Petri lėkštelėse, klimatinėje kameroje RUMED 1301, 22 oC temperatūroje ir esant 65 proc. oro drėgniui. Buvo apskaičiuotas sudygusių žemės ūkio augalų kiekis procentais, išmatuotas jų daigų aukštis ir šaknų ilgis. Tyrimų rezultatai – didžiausias bendrasis fenolinių junginių kiekis nustatytas dirvinio garstuko ir smalkinio tvertiko lapuose (atitinkamai 1,70 ± 0,15 mg g-1 ir 1,81 ± 0,03 mg g-1 žaliosios masės), o trikertės žvaginės ir dirvinės čiužutės – žiedynuose (atitinkamai 1,56 ± 0,02 ir 1,70 ± 0,31 mg g-1). Mažiausiai fenolinių junginių kaupiasi piktžolių šaknyse. Žieminių ir vasarinių rapsų sėklų dygimas ir pradinis augimas labiausiai buvo slopinamas dirvinio garstuko vandeninėse ištraukose, lyginant su kitų piktžolių rūšių vandeninėmis... [toliau žr. visą tekstą] / Research object – charlock mustard (Sinapis arvensis L.), field penny cress (Thlaspi arvense L.), treacle mustard (Erysimum cheiranthoides L.), shepherd’s purse (Capsella bursa-pastoris L.). The aim and methods of investigations – The total phenols content was research in accordance with the methodology (Ragaee et al., 2006 ). Treatments of investigations: Factor A – weed species of Brassicaceae family: 1) charlock mustard (Sinapis arvensis L.), 2) field penny cress (Thlaspi arvense L.), 3) treacle mustard (Erysimum cheiranthoides L.), 4) shepherd’s purse (Capsella bursa-pastoris L.). Factor B – concentrations of aqueous extracts: 1) distilled water, 2) 1: 6250 (ratio of aqueous extracts weed biomass and water), 3) 1: 1250, 4) 1: 250, 5) 1:50, 6) 1:10. The seeds of winter and spring oilseed rape, winter wheat and spring barley was grown for four days on filter paper moistened with the prepared aqueous extracts in Petri dishes, in a climate chamber. Research results – The significant highest content of total phenols was in the leaves of charlock mustard and treacle mustard (respectively 1.70 ± 0.15 mg g-1 and 1.81 ± 0.03 mg g-1 of green mass), in the flowers of shepherd’s purse and field pennycress (respectively 1.56 ± 0.02 and 1.70 ± 0.31 mg g-1). The significant least content of total phenols accumulated in the roots of weeds. The germination and early seedling growth of winter and spring oilseed rape were most inhibited in the aqueous extracts of charlock mustard, compared... [to full text]
238

La tyrosinase : études de nouveaux effecteurs

Dubois, Carole 24 October 2012 (has links)
La tyrosinase est une métalloenzyme à cuivre de type 3 impliquée dans la biosynthèse de la mélanine. La compréhension et la modulation de cette enzyme ont plusieurs enjeux importants, notamment dans les domaines médical, cosmétique et agroalimentaire.A travers la synthèse et l'évaluation de composés actifs, sur la réaction catalysée par la tyrosinase, des relations structures activités ont pu être mises en lumière sur des tyrosinases provenant d'espèces différentes.L'ensemble des molécules analysées a permis de découvrir des inhibiteurs prometteurs de la tyrosinase mais aussi des substrats alternatifs et des activateurs hyperboliques. Cette grande variété d'activité révèle la présence d'un site allostérique sur la tyrosinase d'Agaricus bisporus.Parallèlement, la synthèse d'un analogue d'un inhibiteur compétitif de la tyrosinase (le HOPNO), marquée à l'azote 15, a été réalisée. Cette molécule sonde servira à déterminer, par RMN paramagnétique, le mode de fixation de ce fragment dans le site actif. / Tyrosinase is a copper metalloenzyme type 3 involved in the biosynthesis of melanin.Understanding and modulation of this enzyme have several important issues, including the medical, cosmetic and food .Through the synthesis and evaluation of active compounds, the reaction catalyzed by tyrosinase, structures relations activities have been highlighted on tyrosinases from different species. All molecules analyzed revealed promising inhibitors of tyrosinase but also alternative substrates and activators hyperbolic. This wide variety of activity indicates the presence of an allosteric site on tyrosinase of Agaricus bisporus. Meanwhile, the synthesis of an analogue of a competitive inhibitor of tyrosinase (the HOPNO), labeled with 15 N, was carried out. This probe molecule used to determine, by paramagnetic NMR, the binding mode of the fragment in the active site.
239

Synthèse d’iodanes biaryliques chiraux : application à des réactions d’oxygénation asymétrique

Bosset, Cyril 17 December 2013 (has links)
La chimie des dérivés à base d’iode hypervalent, également appelés iodanes, connaît depuis la fin des années 1990 un essor important qui s’explique par leurs conditions d’utilisation douces et leur faible toxicité comparée à celle des réactifs à base de métaux lourds. Plus récemment, des versions chirales de ces réactifs font l’objet de nombreuses recherches. Dans ce contexte, une première partie de ces travaux de thèse a consisté à développer de nouveaux iodanes chiraux basés sur un squelette biarylique atropoiso-mériquement pur de type soit 1,1’-binaphtyle, soit 5,5’,6,6’,7,7’,8,8’-octahydro-1,1’-binaphtyle. Plusieurs iodobiaryles ont été synthétisés, puis oxydés efficacement et sélectivement au 3,3-diméthyldioxirane (DMDO) pour donner, après une simple filtration, les iodanes correspondants purs. Le degré d’oxydation de l’atome d’iode de chacun de ces composés a été déterminé par spectroscopie RMN 13C : des iodanes-λ3 ont été isolés dans le cas des systèmes binaphtyliques ou substitués par une fonction acide carboxylique en ortho de l’atome d’iode, tandis que des iodanes-λ5 ont été obtenus pour les composés basés sur un squelette octahydro-1,1’-binaphtyle. Dans une seconde partie, ces iodanes ont été appliqués à des réactions d’oxygénation et plus particulièrement à la désaromatisation hydroxylante asymétrique de 2-alkylarénols. Le 2-méthylnaphtol a été converti en son ortho-quinol avec un excès énantiomérique (ee) atteignant 73 %. Des phénols naturels comme le carvacrol et le thymol ont conduit aux cyclodimères [4+2] d’ortho-quinols, le biscarvacrol et le bisthymol, avec des résultats encore meilleurs, respectivement 74 % ee et 94 % ee. / The chemistry of hypervalent organoiodine compounds, also referred to as iodanes, has experienced an impressive development since the 1990s due to their mild oxidizing conditions and their low toxicity compared to heavy metal-based reagents. Recently, chiral versions of iodanes have been focusing several research efforts. In this context, the first part of this work was dedicated to the development of new chiral iodanes with an atropisomerically pure biarylic structure, either 1,1’-binaphthyl or 5,5’,6,6’,7,7’,8,8’-octahydro-1,1’-binaphthyl. Many iodobiaryls were synthesized, and then efficiently and selectively oxidized with 3,3-dimethyldioxirane (DMDO) to furnish the corresponding pure iodanes by simple filtration. The oxidation state of the iodine atom of each compound was determined by 13C NMR spectroscopic analysis: λ3-iodanes were isolated in the case of binaphthylic structures or when the iodoarene bears a carboxylic acid function ortho to the iodine atom, whereas λ5-iodanes were obtained for octahydro-1,1’-binaphthylic compounds. These iodanes were next applied to oxygenation reactions and in particular to asymmetric hydroxylative dearomatization of 2-alkylarenols. 2-Methylnaphthol was converted into its ortho-quinol with up to 73 % enantiomeric excess (ee). Natural phenols such as carvacrol and thymol gave the corresponding ortho-quinol-based [4+2] cyclodimers, biscarvacrol and bisthymol, with even better results of 74 % ee and 94 % ee, respectively.
240

The long-term dynamics of soil organic carbon in the anthropogenic soils of Scotland's medieval urban landscape

Esiana, Benneth O. I. January 2015 (has links)
In an interdisciplinary study requiring the synergistic association of historical evidence and chemical and biochemical analyses, this thesis investigates the properties and characteristics of historically modified soils known as anthrosols. These soils, developed through the anthropogenic addition of high volumes of organic-rich municipal waste materials to land, including human and animal waste, as part of the waste management practices in medieval urban communities in Scotland at St Andrews, Roxburgh and Elgin, offer an insight to the state and dynamics of these organic material. Soil is one of the most sensitive environmental domains to transformation. These transformations are visible from the alterations to the physical and chemical properties of soil. Anthropogenic activities may leave behind signatures in the soil in the form of artefacts, ecofacts, elemental enrichment or depletion, enhancement in soil magnetic properties and organic matter content. In the historical dimension of this study, the observable features and measurable properties of soil profiles are exploited to reveal past organisation and functions of cultural landscapes by carefully studying the stratigraphic units of soil profile, and examining the association of each unit with settlement artefacts and soil properties. Through comparison with historical records of past events on the respective study sites, the relationship between the soils record of past human activities is observed through physical, chemical and biochemical properties. The historical record is used to assess if such evidence can be used reliably to develop the account of site use for the medieval burghs of Scotland. In the environmental aspect, investigation focuses on the physical and chemical conditions of these soils in terms of their carbon content, composition, residence time estimates and their role in global C cycle and terrestrial carbon budgeting. Past investigations of anthopogenically-deepened soils have been interpreted with respect to historical site use, however, the environmental implications of the resultant accumulated organic material or residue have not previously been considered in much detail. A particular novelty of this aspect of the project is that it is an in-depth examination of anthropogenic soils with known histories extending into the medieval period. This time-depth allows a new understanding of the processes and products of decomposition of known organic materials that were added to soil. The biophysicochemical data obtained from these soils such as their extant organic carbon content and variability with depth, the composition of the various carbon species that together constitute soil organic matter, and biological community and activity (microorganisms and enzymes) provides critical information on the relative recalcitrance, state of decomposition, and the mechanism of stabilisation of these materials in the soil.

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