Search

Merge, Mix, Split and Transport, these are the main manipulation steps used for on-chip droplet-based DNA purification (see figure). The system is able to extract genomic material from dilute cell samples by using the actuation of magnetic microparticles within the droplets through a matrix of coils.

Many polyphenols bind proteins, therefore our researchwas focused on the potential of protein binding to polyphenols of investigated fruits and their health-related effects. The contents of polyphenols and related antioxidant activities of traditional, citrus and exotic fruits were compared. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples and their interaction with human serum albumin (HSA) was studied by HPLC, Fourier Transform Infrared (FT-IR) and three dimensional fluorescence spectroscopy (3D-FL). The highest levels of polyphenols, antioxidant and binding capacities were found in red and blond grapefruits (citrus group), followed by strawberries and apples (traditional group) and mangosteen and kiwi fruit (exotic fruit), which also contained the highest levels of protocatechuic, p-coumaric, ferulic acids and quercetin. In conclusion, for the first time, the interaction of the polyphenols with human serum albumin was evaluated by fluorometry/ FTIR. The obtained binding profiles allowed the comparison of three different groups of fruits. A mixture of these fruits can be recommended for consumption.

Human serum albumin has been used as a model protein for protein folding and ligand binding studies over many decades. Due to its long life period and high concentration in plasma, HSA is highly sensitive to glycation. It is reported that 175 mg/dL glucose concentration is a threshold of kidney activity for the beginning of excretion of glucose. pH denaturation of HSA in absence and presence of different concentrations of glucose is studied and based on the Pace two-state model, the findings are analyzed. In addition, florescence emission data of albumin range in the period of 300-500 nm was depicted. The amounts of free energy change and [D]1/2 parameters of unfolding in correspond to florescence date indicate that glucose induces fine structural change in human serum albumin. Results showed that 175 mg/dL glucose concentration is a critical point for albumin structural and functional alteration.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013, Floresans özellik gösteren boyalar uzun yıllardır çeşitli araştırma grupları tarafından incelenmektedirler. Bodipy boyaları ve bodipy ailesinin göstermiş olduğu enteresan fotoelektirik özellikler grubumuzu bu tarz boyaların çalışmasına yöneltmiştir. Bor içeren bu grup boyaların göstermiş olduğu enteresan optoelektrik özellikler sayesinde sensörleme, güneş pilleri, fotodinamik terapi gibi uygulama alanlarında araştırma konusu olmuşlardır. Bodipy ailesinden olan boranil türevlerini elde etmek için imin ( anil ) yapısı gerekmektedir. Salisil aldehit ve çeşitli aromatik primer aminlerle anil türevleri elde edilmiştir. Aynı zamanda salisil aldehitin türevlendirilmesiyle farklı anil türevlerinin sentezi gerçekleştirilmiştir. Bunun yanı sıra simetrik ikili imin ( anil ) türevleri benzidin, 4,4’-diaminometilen, o-fenilendiamin kullanılarak sentezlenmiştir. Boranil türevleri imin türevleriyle sentezlenmiştir. Bu reaksiyonlarda imin türevi çıkış maddesi olarak kullanılmıştır. Sentez sırasında farklı yöntemler kullanılmıştır. Anil bileşiklerinin ikili olması sonucunda ikili boranil bileşikleri sentezlenmiştir. Bu tez çalışmasında salisil aldehitin p-toluidin, o-anisidin, 2,4-dikloroanilin, benzidin, α-naftilamin ile pH: 3-4 olan ortamda olan reaksiyonundan çeşitli imin türevleri elde edilmiştir. Reaksiyon verimleri çok yüksek olup ikili imin türevlerinin verimlerinin çözücüye bağlı olduğu görülmüştür. Salisil aldehitle aromatik primer aminlerin reaksiyonu sonucu tek ürün elde edilmiştir ve ürünler katıdır. Ürünün katı olması saflaştırmasının kolay olmasını ve zaman tasarrufunu sağlamıştır. Anil bileşiklerinin çeşitli spektrumlarla desteklenmesinin ardından sentezlenen imin (anil) bileşiklerinin bor komplekleri ( boranil ) elde edilmek istenmiştir. Boranil bileşiklerini elde etmek için imin bileşiğinin bortriflorür dietileterat ile (BF3.OEt2) bazik ortamdaki reaksiyonu gerçekleştirilmiştir. Ortamın bazikliğini sağlamak için tri etil amin ( N(Et)3 ) yada tri etanol amin ( N(CH2CH2OH)3 ) kullanılmıştır. Reaksiyonlar 80-90oC sıcaklıkları arasında gerçekleştirilip, reaksiyon süresinin değişkenliğinin eklenen bor triflorür dietileteratın ekivalentine bağlı olduğu görülmüştür. Kullanılan çözücününde reaksiyon üzerinde önemli etkisi olduğu görülmüştür. Özellikle ikili imin bileşiklerinin reaksiyonları tek imin bileşiklerine oranla daha yüksek sıcaklıklar gerektirdiğinden, reaksiyonlarında kaynama noktası yüksek olan 1,2-dikloroetan, kloroform gibi klorlu çözücüler kullanılmıştır. Sentezlenen boranil bileşiklerin karakterizasyonu 1H-NMR ve 13C-NMR spektrometreleriyle gerçekleştirilmiştir. Boranil bileşiklerinin sahip olduğu optik ve elektirik özellikler UV-Vis ve Floresans spektroskopisiyle ölçülmüştür. Elde edilen veriler ışığında sentezlenen çıkış maddelerinin ve bor komplekslerinin uygulama alanları hakkında araştırılma yapılmıştır., Dyes having flourescence properties have been studied for many years by different research labs. BODIPY dyes and their family show interesting optical, electrical behavior that channel us to study on them. Thanks to their properties that have been mentioned above, these dyes have been research subject at many applications. Such as; sensoring, DSSC, PDT. Imine structure is essential to synthesize boranil derivatives which are family of BODIPY. Imine derivatives have been obtained by reaction between salicyl aldehyde and different primer amines. Also, symmetrical bis-imine derivatives have been synthesized by reaction between salicyl aldehyde and 4,4’-diaminomethylene, o-phenlyenediamine. In this thesis, imine derivatives have been synthesized by reaction between salicyl aldehyde and o-phenylenediamine, benzidine, 2,4-dichloroaniline, 3-nitroaniline, α-naphtylamine under acidic conditions. ( pH: 3-4 ) The yields of reactions are high and we realize that yields of bis-derivatives strictly dependent on solvent. Only one product is obtained and products are solid so that purification is easy and time-saving. We have wanted to synthesize boron complexes ( Boranils ), as all imine derivatives have been supported by different spectral analysis. To synthesize Boranil complexes, imine derivatives have been reacted with BF3.OEt2 under basic conditions. N(Et)3 and N(CH2CH2OH)3 have been used to provide basicity of reaction media. All reactions carried at 80-90oC , and we have seen that variability of reaction times depend on quantity of BF3.OEt2, and solvent has important effect on reaction process. Especially, the reaction of bis-imine compounds need high temperature when compare with mono-imine compounds. Therefore, in the reaction of bis-imine compound, we have used 1,2-dichloroethane and chloroform as a solvent because of their high boiling points. Characterization of synthesized boranil complexes have been supported by 1H-NMR, 13C-NMR and FTIR spectroscopies, and optic properties of boranil complexes have been measured via UV-Vis and Spectrofluorometer spectroscopies. On the basis of spectroscopic analysis, boranil complexes may be use in many application fields. The nature of fluorophore provide us some different properties explaining by PET and ICT. These two phenomena mostly have been act in sensoring and switching. PET ( Photoinduced Electron Transfer ) is an electron transfer which occurs when certain photo-active materials, in this case boranil complexes, interact with light. There are two type of PET processes. One is oxidative PET, the other is reductive PET. If the excited state of fluorescent group can accept electron from donating group, then the reductive PET occurs. However, if the excited state of fluorescent group can donate electrons to acceptor, then the oxidative PET occurs. Not being directly, solvent polarity has an effect on this process. When PET processes occur both ways, then the fluorescent is diminished. ICT ( Intramoleculer Charge Transfer ) is an association of two or more molecules, or of different parts of one very large molecule, in which a fraction of electronic charge is transferred between the molecular entities. In principle, ICT has been used to recognition of ions. If the molecule has electron donating group to fluorescent group, then molecule is not emissive. To alter emission properties, donation blocker is introduced to molecule. Such as, if molecule has dimethylamino group close to fluorescent group, donation of dimethylamino can be blocked by introducing acid or complexation with metal ion. Therefore, nitrogen atom in dimethylamino group is charged, so electron donation can be blocked. When electron donation is blocked, positive charge on nitrogen atom can be transferred within the molecule causes increase of emission. In some cases this process occurs reverse. There are many examples of ICT and PET processes involved. Such as Hg+2 sensoring, Cu+2 sensoring, Zn+2 sensoring, CN- sensoring, F- sensoring, nitric oxide recognition and amine recognition. As a benefit of fluorophore, besides of recogniton and of sensoring, boranil complexes can be used as a light harvesting molecules and energy transfer cassettes. In many occasions, energy transfer cassettes are used as biolabelling and monitoring. Energy transfer cassettes are supramolecular compounds having donor and acceptor sites that makes them tunable sensoring tool for labelling. Light harvesting molecules can be simply explained as a molecule having energy transfer between donor and acceptor unit. Energy transfer can be taught as radiationless transition between two localized electronically states. If there is no energy transfer, dye molecule absorbs the light and give some emission. However, if there is a another dye which can be capable of absorbing first dye`s emissions. Then energy transfer occurs and acceptor dye ( unit ) make emission as fluorescence. In light harvesting molecules, energy transfer efficiency is dependent on many factors. Such as, strenght of donor and acceptor unit, spectral overlap between energy donor and energy acceptor, distance between donor and acceptor unit. Energy transfer is accrued by two ways. First one is through bond ( Dexter Type Energy Transfer. ), second one is through space (FRET: Förster Resonance Energy Transfer.). Dexter type energy transfer requires orbital overlap between donor and acceptor by a bridge and the decay is exponantially depend on the distance. Förster type energy transfer follows trough-space and does not require physical contact between donor and acceptor. The rate of energy transfer inversely depends on distance between donor and aceptor. The important conditions for efficient resonance energy transfer are a good overlap between fluorescence spectrum of donor with absorption spectrum of acceptor. In this thesis, our group is aimed to synthesize efficient tiny fluorophore which can be used in sensoring devices, energy transfer cassettes, light harvesting molecules., Yüksek Lisans, M.Sc.

This thesis is supported by a European project called "microfluiD" for the detection of organic pollutants by microfluidic devices (mycotoxins in animal feed, bacteria and heavy metals). Because of hazards Pb2+, Hg2+ and Cd2+ ions in the environment, it is important to increase the number of assays in tap water. The use of fluorescence or microlaser has many advantages: in addition to their low cost, sensitivity and selectivity, it is possible to design portable devices based on these systems in the field. Two approaches are mainly developed in this work: The first one is based on fluorescence. Two fluorescent sensors were synthesized: CalixDANS-3-OH for Pb2+ detection and DPPS-PEG for Hg2+ detection. Complexation of Hg2+and Pb2+ was at first performed in solution. The complexation of Cd2+ in microfluidic device from the commercial compound Rhod-5N is studied and very promising results of Hg2+ sensing by DPPS-PEG are obtained. We also studied the possibility to detect Pb2+ by CalixDANS-3-OH grafted onto the walls of the microfluidic device. Despite a degradation of the probe, we were able to detect low concentrations of Pb2+. A very good selectivity towards several interfering cations was obtained. The second approach is based on the use of microlasers. We synthesized two porous block polymers for Pb2+ and Hg2+ detection. Because of a bad solubility of the copolymers, we didn't succeed to fabricate microcavities from these polymers. A second strategy which consists in grafting the specific ligands of Pb2+ and Hg2+ on the PMMA microcavity is very promising. Proof of principle of the detection of Hg2+ is obtained by functionalizing mercaptopropyltriethoxysilane on the surface of PMMA. This work also led us to synthesize Bodipy laser dyes for the manufacturing of microcavities by two-photon polymerization (2PP)., Ce travail de thèse s'inscrit dans le cas d'un projet européen nommé " microfluiD ". Ce projet vise principalement la détection des polluants organiques par voie microfluidique (les micotoxines dans les aliments de bétail, les bactéries et les métaux lourds). Devant les dangers écologiques des ions Pb2+, Hg2+ et Cd2+ dans l'environnement, il est important de multiplier le nombre d'analyses dans les eaux du robinet. L'utilisation de la fluorescence et des microlasers organiques présente de nombreux avantages. Outre leur faible coût, leur sensibilité ainsi que leur sélectivité, il est possible de concevoir à partir de ces techniques des dispositifs transportables sur le terrain. Deux approches sont principalement développées : Une première est basée sur la fluorescence ; elle a consisté à synthétiser des ligands fluorescents de type DPPS-PEG et CalixDANS-3-OH pour la détection du mercure et du plomb. Les études de la complexation des ions Hg2+, Pb2+ ont d'abord été effectuées en solution. La complexation de Cd2+ en circuit microfluidique à partir du composé commercial Rhod-5N a aussi été étudiée. Des résultats très prometteurs ont été obtenus pour la détection de Hg2+ par DPPS-PEG. Nous avons aussi étudié la possibilité de détecter Pb2+ à partir du CalixDANS-3-OH greffé sur les parois du circuit microfluidique. Malgré une dégradation de la sonde, nous avons réussi à détecter une faible concentration de plomb. Une très bonne sélectivité vis-à-vis des cations interférents testés a été obtenue. La seconde approche est basée sur la détection par microlasers. Nous avons synthétisé deux copolymères blocs pour la détection du plomb et du mercure. Des problèmes de solubilité nous empêchant de fabriquer des microcavités organiques à partir de ces polymères, une deuxième stratégie consistant à greffer les ligands spécifiques de Pb2+ et de Hg2+ sur les microcavités laser PMMA a été développée. Cette dernière nous a permis d'apporter une preuve de principe pour de la détection du mercure en fonctionnalisant le mercaptopropyltriéthoxysilane à la surface du PMMA. Ce travail nous a aussi amené à synthétiser des colorants laser à base de Bodipy pour la fabrication des microcavités lasers par polymérisation à deux photons (2PP).

The effect of pruning on length of the fruiting branches, distribution of male and female florescence as well as yield of three hazelnut cultivars (Istrian long, Roman and Tonda Gentile delle Langhe) have been studied. The experiment has been carried out at the experimental field 'Radmilovac', premises of the Faculty of Agriculture, Zemun. Pruning exhibited considerable effect on all evaluated parameters. Acquaintance with the zones of formation of male and female flowers is of major importance for adequate application of pruning. Zones in which both male and female flowers mostly occur largely coincide in the fruiting branches of the same length. Fruiting branches up to 10 cm length should never be cut, as by the removal of the terminal and the initial nodus 85% of the fully formed female flowers on respective branch would be eliminated. Differences in fruit weight between pruned and unpruned bushes ranged from 4.35% to 10.99%, whereas yield differences were about 20%. Primenom agrotehničkih mera kao što su obrada, đubrenje i navodnjavanje obezbeđuje se uspevanje leske, ali se pun uspeh u toj proizvodnji može ostvariti tek onda ako se sa ovim merama kombinuju i raznovrsne mere kojima se uglavnom regulišu vegetativno rastenje i generativni razvitak. U nizu tih mera najveći značaj ima rezidba, kojom se usklađuje vegetativni i generativni potencijal. U ovom radu ispitivan je uticaj rezidbe na produktivnost rodnih grančica tri sorte leske: Istarski dugi, Rimski i Tonda Gentile delle Langhe. Dobijeni rezultati ukazuju na postojanje značajnih razlika između ispitivanih obeležja, kao što su dužina rodnih grančica, broj i raspored muških i ženskih cvasti na grančici, morfometrija ploda, randman i prinos. Ispitivanja su imale za cilj da utvrde da li i u kojoj meri rezidba utiče na rast i rodnost u cilju intenziviranja proizvodnje lešnika.