Search results for "väriaineet"
showing 10 items of 16 documents
Indigon sinisestä kokenillin punaiseen : tekstiilivärjäyksessä käytettyjen luonnonväriaineiden tuonti Suomeen (1791–1856)
2022
Tutkimme ulkomaisten luonnonväriaineiden tuontia Suomeen 1790-luvun alusta 1850-luvun puoliväliin. Ajankohtaa voidaan luonnehtia murroskaudeksi väriaineiden käytön historiassa. Selvitämme mitä väriaineita Suomeen tuotiin, millaisia määriä, minneniitä tuotiin sekä mistä satamista väriainelastit olivat lähtöisin. Lähdeaineistomme perustan muodostavat Tanskan Juutinrauman tullitilit, joista on koostettu suomalaisia satamia koskeva tietokanta (FIN-STRO: 1560/1791–1856). Lähdepohjaa on täydennetty muulla tilastoaineistolla sekä laadullisella materiaalilla, kuten värjäysoppailla ja Kansalliskirjaston digitaalisella sanomalehtiarkistolla. Tutkimme erityisesti sinistä, punaista ja keltaista väriä t…
Dye molecules on titatium dioxide surface: cluster and periodic surface models
2008
Optimizing the SYBR green related cyanine dye structure to aim for brighter nucleic acid visualization
2022
In recent years, the studies of RNA and its use for the development of RNA based vaccines have increased drastically. Although cyanine dyes are commonly used probes for studying nucleic acids, in a wide range of applications, there is still a growing need for better and brighter dyes. To meet this demand, we have systematically studied the structure of SYBR green-related cyanine dyes to gain a deeper understanding of their interactions with biomolecules especially how they interact with nucleic acids and the structural components which makes them strongly fluorescent. Herein, five new dyes were synthesized, and their photophysical properties were evaluated. Observations of photophysical cha…
Covalent and non-covalent coupling of a Au102 nanocluster with a fluorophore : energy transfer, quenching and intracellular pH sensing
2021
Interactions between an atomically precise gold nanocluster Au102(p-MBA)44 (p-MBA = para mercaptobenzoic acid) and a fluorescent organic dye molecule (KU, azadioxatriangulenium) are studied. In solution, the constituents form spontaneously a weakly bound complex leading to quenching of fluorescence of the KU dye via energy transfer. The KU can be separated from the complex by lowering pH, leading to recovery of fluorescence, which forms a basis for an optical reversible pH sensor. However, the sensor is not a stable entity, which could be delivered inside cells. For this purpose, a covalently bound hybrid is synthesized by linking the KU dye to the ligand layer of the cluster via an ester b…
Modeling optical constants from the absorption of organic thin films using a modified Lorentz oscillator model
2022
Optical constants of organic thin films can be evaluated using the Lorentz oscillator model (LOM) which fails to fit inhomogeneously broadened absorption of highly concentrated molecular films. In modified LOM (MLOM), the inhomogeneous broadening is implemented through a frequency-dependent adjustable broadening function. In this work, we evaluate the optical constants of rhodamine 6G doped poly-vinyl alcohol thin films with varying doping concentration (including also extensively high concentrations) using MLOM, which outperforms LOM by showing a better agreement with the experimental results. Our proposed method provides a way to accurately determine optical constants of isotropic organic…
Luonnontieteellisin analyysimenetelmin tunnistettu Akseli Gallen-Kallelan väripaletti
2020
Artikkeli on kokonaisuudessaan ensimmäinen laatuaan Suomessa ja se esittelee tutkimuksen tuloksia koskien Akseli Gallen-Kallelan käyttämiä väriaineita. Tutkimusaineisto on läpileikkaus taiteilijan taiteellisesta tuotannosta vuosilta 1880–1929. Se koostuu 265:stä maalauksesta ja 83:sta öljy- ja temperavärituubista. Tutkimuksessa käytetyt analyysimentelmät ovat ainetta tuhoamattomia luonnontieteellisiä analyysimenetelmiä: energiadispersiivinen röntgenfluoresenssi spektroskopia (EDXRF) ja polarisaatiomikroskopia (PLM).
 
 Avainsanat: Akseli Gallen-Kallela, taiteilijatarvike, väriaine, pigmentti, taiteen materiaalitutkimus, EDXRF, polarisaatiomikroskopia.
Observations on the Painting Technique and Materials Used in the Painting of Lake View, by Akseli Gallen-Kallela
2021
Development of functionalized SYBR green II related cyanine dyes for viral RNA detection
2020
Fluorescent probes for sensing nucleic acids have found widespread use in the field of cell and molecular biology. However, probes combined with potential for post-synthetic conjugation, e.g. for intra-endosomal measurements of RNA, are unavailable. Herein we developed cyanine dyes that can be conjugated to viral capsid or other targets. First, we solved the crystal structure of SYBR Green II. The structural elucidation of this commonly used RNA probe provided the basis for synthesizing similar molecules with much desired function for post-synthetic conjugation. To address this need, cyanine dyes were prepared using an alternative synthesis protocol. All studied compounds showed considerabl…
Interaction between surface plasmon polaritons and molecules in strong coupling limit
2016
Miniaturization of optical elements and their integration to electronic circuits is limited by diffraction limit. It was realized that light being coupled to surface plasmons (SP) can overcome this limit. Employing also optically active molecules in combination with SPs can drive optical circuits to nm-scale and add functionalities. For efficient performance of plasmonic elements involving fluorescent dye molecules investigation of physics behind their interaction is of high priority. In this thesis interaction between surface plasmon polaritons (SPPs) and different dye molecules has been studied, especially within strong coupling limit, which brings in totally new physical properties in th…
H&E Multi-Laboratory Staining Variance Exploration with Machine Learning
2022
In diagnostic histopathology, hematoxylin and eosin (H&E) staining is a critical process that highlights salient histological features. Staining results vary between laboratories regardless of the histopathological task, although the method does not change. This variance can impair the accuracy of algorithms and histopathologists’ time-to-insight. Investigating this variance can help calibrate stain normalization tasks to reverse this negative potential. With machine learning, this study evaluated the staining variance between different laboratories on three tissue types. We received H&E-stained slides from 66 different laboratories. Each slide contained kidney, skin, and colon tissue sampl…