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EN
The civilization diseases of the 21st century are non-infectious disorders, affecting a large part of modern society. They are associated with the significant development of industry and technology, and hence with environmental pollution and an unhealthy lifestyle. These factors have led to the development of many civilization diseases, which currently include: cardiovascular diseases, respiratory diseases, diabetes, obesity, malignant tumors, gastrointestinal diseases, mental disorders and allergic diseases. The development of technologies, including modern therapies and new drugs, resulted in increase in life expectancy. This creates a global problem of an aging population with an increasing number of diseases of the old age, i.e. dementias. In addition, sedentary lifestyles and changing diets are the reasons why more and more people develop metabolic diseases, as well as neurological and cognitive disorders characterized by progressive damage to nerve cells and dementia. Currently, problem on a global scale is also the growing resistance to existing antimicrobial drugs. Therefore, the scientists face many challenges related to searching for the causes of these diseases, their diagnosis and treatment. Scientific research conducted at the Department of Biomedical Chemistry at the Faculty of Chemistry of the University of Gdańsk is part of this research trend. In this publication, we discuss various research topics with the long-term aim of solving the problems associated with the diseases mentioned above. The following chapters are dedicated to (i) looking for new effective fluorophores with diagnostic and anti-cancer activity; (ii) designing of new compounds with antibacterial and antiviral activity and their synthesis; (iii) investigating the mechanisms of amyloid deposit formation by human cystatin C and possibilities of inhibition of this process; (iv) designing and studies of compounds activating the proteasome with the potential to suppress the development of neurodegenerative diseases; (v) designing peptide fibrils and hydrogels as drug carriers; (vi) searching for peptide inhibitors of immune checkpoint as potential drugs for immunotherapy; (vii) studying the mechanism of action of selected herpesviruses by determining the structure of viral proteins and (viii) studying the composition of natural glycans and glycoconjugates in order to better understand the mechanisms of interaction of bacteria with the environment or with the host.
EN
Frying is a popular method of cooking (meals preparation). Heating and deep-fat frying cause a series of chemical reactions, such as oxidation of polyunsaturated fatty acids and vitamin E, as well as formation of trans isomers and products of peroxidation. These chemical reactions cause organoleptic and nutritional changes in the product, which may have a negative effect on health. For this reason, the usefulness of many methods for evaluation of refined oils quality is investigated. The fluorescence spectroscopy is increasingly used for this purpose. The aim of the study was to monitor the changes in emission and excitation spectra of refined rapeseed oil and sunflower oil after processes of heating and frying frozen French fries. The obtained results show the differences between the shapes of fluorescence excitation and emission spectra of both oils due to the two processes and these changes depend on duration of both processes. This study indicates that fluorescence spectroscopy is a promising method for evaluation of changes in oils during heating or frying.
EN
Lipid-protein systems paly curtail roles in living systems [49]. Hence, a determination of their structure at different levels of organization is still one of the most important tasks in many research projects. A study of lipid-protein systems is based on many physicochemical techniques, such as spectroscopy of FTIR, Raman, fluorescence, NMR, EPR, as well as DLS, DSC and TEM methods. In the presented paper tow of the most frequently used methods, that is FTIR and fluorescence spectroscopy, will be discussed in details. They are characterized by a relatively low cost of sample preparation, a short measuring time, and they give a huge number of structural and physicochemical information about lipid-protein systems. In the FTIR-ATR spectroscopy many of vibrational bands are commonly used as very precise vibrational indicators of structural changes in lipids and proteins (Fig. 1) [1–6]. They allows to characterize lipid and protein components separately in mixed systems. Additionally, structural changes in lipid membranes can be monitored in one FTIR-ATR experiment simultaneously in a region of hydrophilic lipid head-groups (Fig. 5) [17, 18], in a hydrophobic part composed of hydrocarbon lipid chains (see Figures 2 and 3) [7–9], and in a lipid membrane interface represented by ester lipid groups (Fig. 4) [4, 6, 11, 12]. A secondary structure of proteins and peptides in different experimental conditions can be defined in the FTIR-ATR spectroscopy on the base of amide I bands (Fig. 6 and Tabs 1, 2 and 3) [20–22]. A fluorescence spectroscopy is a complementary methods to FTIR spectroscopy in a study of lipid-protein systems. It competes information about time-dependent and very fast (in a scale of femtoseconds) structural processes in both lipids [41–45] and proteins [23, 27, 48]. The folding, denaturation, and aggregation of proteins and lipid membranes accompanied by changes in an order, packing and hydration of the system under study [23, 27, 41–45, 48].
PL
Wiedza o zawartości sumy naturalnych substancji organicznych nie jest obecnie wystarczająca zarówno przy planowaniu, jak i eksploatacji instalacji do oczyszczania wody. Pogłębiona charakterystyka zawartych w ujmowanych wodach naturalnych związków organicznych pozwala na lepsze zrozumienie ich przemian w procesach oczyszczania wody, a także odgrywa bardzo ważną rolę podczas optymalizacji pracy poszczególnych etapów układu technologicznego. Powszechnie stosowanym wskaźnikiem do analizy związków organicznych w wodzie jest absorbancja w nadfiolecie, która umożliwia zarówno ocenę jakościową, jak i ilościową tych związków. Absorbancja właściwa w UV (SUVA), jako odniesienie wartości absorbancji w 254 nm do zawartości w wodzie rozpuszczonego węgla organicznego, umożliwia natomiast kontrolę procesów oczyszczania wody, zwłaszcza w zakresie dawkowania koagulantów oraz utleniaczy. Inne metody charakterystyki naturalnych substancji organicznych stanowią domenę prac badawczych i nie są szerzej wykorzystywane w praktyce funkcjonowania przedsiębiorstw wodociągowych. Wśród nich na uwagę zasługują techniki spektroskopii fluorescencyjnej, które pozwalają na monitorowanie jakości wody w czasie rzeczywistym i cechują się zwiększoną selektywnością oraz czułością w zestawieniu z absorbancją w nadfiolecie. Analiza fluorescencyjna, umożliwiająca identyfikację frakcji biodegradowalnej związków organicznych, pozwala na wybór właściwych metod ich usuwania. Bardzo duże możliwości analityczne zapewnia chromatografia, zwłaszcza w połączeniu z szeroką gamą dostępnych detektorów. Umożliwia ona badanie takich cech substancji organicznych, jak masa cząsteczkowa, polarność, aromatyczność czy podatność na tworzenie ubocznych produktów dezynfekcji wody. Daje to szerokie możliwości interpretacyjne w odniesieniu do optymalizacji pracy układu technologicznego oczyszczania wody. Bardzo pomocne do charakteryzowania składu wody pod względem obecnych w niej związków organicznych są także metody frakcjonowania z wykorzystaniem membran lub żywic selektywnych. Separacja cząsteczek substancji organicznych według takich cech, jak wielkość, hydrofilowość czy kwasowość, pozwala na otrzymanie wyselekcjonowanych próbek, które mogą być poddane dalszym badaniom.
EN
Today’s knowledge on total Natural Organic Matter (NOM) content proves not sufficient both at planning and operation of water treatment installations. Detailed characteristics of NOM present in raw and treated water enables better understanding of its changes during water treatment processes as well as substantially contributes towards operation optimization of subsequent stages of a technological set-up. UV absorbance, a common indicator used for NOM analysis in water, allows for both its qualitative and quantitative assessment. Specific UV absorbance (SUVA), being the UV absorbance of a water sample at 254 nm normalized for dissolved organic carbon (DOC), allows monitoring of water treatment processes, especially in terms of coagulant and oxidizing agent dosing. Other NOM characterization methods are a domain for research and are not widely employed in daily practice of water supply corporations. Among those techniques, fluorescence spectroscopy methods are worth noticing as they enable water quality monitoring in real time and are characterized by higher selectivity and sensitivity compared to UV absorbance. Fluorescence analysis that allows identification of biodegradable organic fractions, enables selection of adequate methods of their removal. Chromatography offers a number of analytical capabilities, especially when combined with a wide range of available detectors. It allows examination of NOM characteristics such as molecular weight, polarity, aromaticity or susceptibility to water disinfection by-product formation. Thus multiple possibilities of interpretation arise in regard to optimization of technological system operation in water treatment. In terms of NOM presence, fractionation methods employing membranes and selective resins are particularly helpful in water composition characterization. NOM particle separation according to its size, hydrophilicity, acidity and others enables monitoring its removal susceptibility in particular treatment processes and predicting the technological effects based on NOM characteristics.
EN
Reliability of the ship propulsion system depends, inter alia, on the quality of lubricate oils. Research indicates that exploitive features of oil are reduced with it runtime in the ship engine circuit. At the present the basic parameters representing exploitive features of oil are: water content, total acid number and total base number or viscosity vs. temperature, anti-wear performance, further: content of additives and their concentrations, reaction products, and other contaminating substances, also magnetically separated large ferromagnetic particles, the size, the shape, the composition and concentration of the abnormal wear particles. Additional properties of oil are described based on atomic emission spectroscopy, granulometry of separated from the lubricant sample by magnets and gravity, permeability changes, as well as rheometric and tribometric characteristics. Complexity of composition of lubricate oil raises the idea to use changes of relative content of any compounds for characterization of oil exploitive features. Fluorescence method is possible to use for oil properties characterisation due to the presence mono and polycyclic compounds in oil that induces fluorescence phenomenon. Therefore identification the fluorescence spectra when exploitation time of oil increases could be novel indicator to monitor of lubricate oil exploitive quality. In this study we present changes of oil fluorescence expressed by synchronous spectra, taking into account working time of exemplary lubricate oil in the ship engine.
EN
In the work the fluorescence spectroscopy based on fluorescence spectra for single excitation wavelength and excitation spectra for single emission wavelength were applied to expand the knowledge about the specific signatures of lubricate oil typically used in ship engine as a tool to oil quality assessment. The fluorescence properties of oil are considered based on an exemplary lubricate-engine oil in two forms: fresh and used oil – exploited an adequate time. Based on the fluorescence spectra for single excitation wavelength and excitation spectra for single emission wavelength the changes of the spectra for both forms of oil are discussed and the peaks typical for both forms of oil were determined. Moreover the specified fluorescence signatures described by selected fluorescence spectrum for excitation wavelength 220 nm as a tool to distinguish the two forms of oil were determined. Additionally, there is discussed the use of total excitation spectrum as a tool to identification two forms of oil.
PL
W pracy przedstawiono metodę spektroskopii fluorescencyjnej jako narzędzia do śledzenia jakości oleju silnikowego, które pozwoli na poszerzenie wiedzy odnośnie do typowych wskaźników różnicujących oleje. Analizę właściwości fluorescencyjnych silnikowego oleju smarnego przeprowadzono, wykorzystując dwa rodzaje widm: widma fluorescencji dla pojedynczej długości fali wzbudzenia oraz widma wzbudzenia dla pojedynczej długości fali emisji. Fluorescencyjne właściwości oleju dyskutowane są w odniesieniu do przykładowego silnikowego oleju smarnego w dwóch formach, odpowiednio, oryginalnej oraz zużytej podczas pracy w silniku okrętowym w odpowiednim czasie pracy. Na podstawie widm fluorescencji, jak również widm wzbudzenia, dyskutowane są zmiany w kształcie widm w odniesieniu do obu form oleju oraz wyznaczone specyficzne piki dla obu form oleju. Ponadto wyznaczono charakterystyczne wskaźniki fluorescencyjne dla rozważanego rodzaju oleju z wykorzystaniem zarówno wyselekcjonowanego widma fluorescencji dla długości fali wzbudzenia 220 nm, jak i wyznaczonego całkowitego widma wzbudzenia jako narzędzia do rozróżniania obu form oleju.
EN
The natural seawater contains both dissolved and suspended organic substances originating from natural sources and human activities – like the marine transport fleet among other. To specify the type and quantity of vitally valid as well as dangerous for properly functioning marine ecosystems substances complicated and sophisticated chemical instrumentation and methodologies must be used. Only a small number of seawater components it is possible easily to determine their concentrations – for example, the salt content is determined directly in the bulk of water through simultaneous measurement of electrolytic conductivity and temperature of water. It is worth to search similarly quick method for oil substances directly in the seawater. Taking into account seawater organic pollutants originating from natural sources inter alia crude oils, the presence of refinery petroleum substances due to their fluorescence in ultra-violet light can be determined based on fluorescence spectroscopy. The aim of this paper is to search fluorescence features of oil substances dissolved in natural seawater based on excitation-emission spectroscopy. In the paper fresh and oily contaminated seawater taken from the coastal area of the Baltic Sea were used. As an oil pollution ‘Petro-baltic’ oil were applied. The natural seawater, at first was laboratory exposed to low extremely amount of oil and then it was examined by fluorescence under UV light. The seawater from vicinity of Gdynia (Poland) were tested as fresh and after artificially contaminated by different amount of oil (from 0.5 to 500 ppm). Spectrofluorometer Hitachi F-7000 FL was applied to measure excitation-emission spectra (EEMs). Low amounts of oil (up to several ppm) cause increasing of main peak in excitation-emission spectra (EEMs). Addition of larger amounts of oil results in appearance new peaks, which originate from fluorescence of soluble fractions of oil artificially added to examined water. These specific features of oil describe the spectroscopic signatures of oil, which is the basis to development operational method of the source of oil pollution identification.
EN
The significant part of petroleum substances is transferred to the marine environment after technical activities (inevitable exploitive spills, illegal discharges). However a certain part of petroleum in seawater coming from the natural sources. Therefore, to develop the safety of natural marine environment it is necessary to track not only the anthropogenic pollutants but also the natural sources of petroleum. To distinguish both source of oil the fluorescence properties of oil can be used as the tools to oil identification. The aim of the study is to describe the optical properties of crude oil after it contact with aquatic environment based on fluorescence spectroscopy. For the study, crude oil ‘Petrobaltic’ type potentially found in marine environment due to coming from natural source was applied. To dissolve oil, two different solvent – hexane and Baltic seawater form the Gdynia coast were used. To measure the excitation-emission spectra (EEMs) of oil spectrofluorometer Hitachi F-7000 FL was applied. In the paper, we discuss the changes of oil EEMs in two cases for oil dissolved in n-hexane and for oil dissolved in seawater for various oil concentration. Obtained EEMs for oil dissolved in seawater indicate that EEMs spectrum contain the main peak – describing by the wavelength – independent fluorescence maximum, which was detected for oil dissolved in n-hexane (typical for this kind of oil). However, the intensity of oil fluorescence decreases after oil contact with seawater. This approach could allow expanding the description of complex mixtures of oils as a possible tool proposed for identification the type and origin of oil found in marine environment.
EN
Exploitive features of lubricate oils are externalised by various physical and chemical parameters (for example temperature dependencies of density and viscosity, ignition point or water content). On the other hand it is well-known that fluorescence spectra of various types of crude oils and their derivatives are strongly differ from each other. It is reasonable thesis, that exploitive features of oil may be related to transformations of light inside the oil. Therefore, despite of that fact light transformations strongly depend on chemical composition of oil (especially from the content of cyclic and polycyclic molecules). No one can exclude, that physical conditions are for fluorescence processes closely related to changes of physical and chemical properties of oil (and consequently to exploitive features) as well as to newly arising compounds and intrusions (for example metals, caused by contact with various engine elements). The paper presents spectra of fluorescence of exemplary lubricate oil (Marinol) in various configurations, namely: emission spectrum for individual excitation wavelength, excitation spectrum for single emission wavelength, excitation-emission spectrum, synchronous fluorescence spectroscopy and total synchronous fluorescence spectroscopy. Dynamic structures of those spectra gives reason to conclude that shapes of fluorescence spectra may be controlled by exploitive features of oils.
10
EN
Contribution of marine carriage in the global transport is in permanent developing. It leads to increase the unintentional oil spills, which may induce serious disturbances in functioning of the natural marine ecosystem, especially when it interferes with other technical activities in the marine space. That fact contributes to increase the interest in searching of new research techniques to protect the natural ecosystem. Therefore, the main task of marine international organisations concentrates on the effective and rapid detection of oil spill and on the possibility of identifying oil pollutants as well as on origin of pollution. The purpose of the study is to characterise the oil belonging to the vessel engine lubricate oils. We analyse the stage results of investigations based on one of types of fluorescence spectroscopy, namely: synchronous spectra. To characterise the oil, the Aqualog Horiba spectrofluorometer was applied, which allows performing precise measurement in a short time. Based on the measured excitation-emission spectra, total synchronous fluorescence spectra for oil were obtained using various wavelength intervals. Total synchronous fluorescence spectra of petroleum substances allow finding wavelength interval typical for particular type of oil. This approach could allow obtaining of complex mixtures, such as oils, more efficient description. We discuss the total synchronous fluorescence spectra for engine oil (Marinol type) dissolved in n-hexane in various concentrations of oil as a possible tool proposed to oil type identification. We present changes and variation of the total synchronous fluorescence spectra for oil with various oil concentrations.
EN
The main task for natural marine environment protection is to prevent the inflow of various contaminants including oil substances and the real challenge is the ability to rapidly detect these pollutants. Moreover important is to find the source or the maker of the oil spill. In this paper, we consider fundamental physical aspects in the area of possibility of monitoring the natural marine ecosystem based on fluorescence spectroscopy. We utilize the fluorescence ability of numerous oil components – mainly polycyclic hydrocarbons. The paper concerns the spectrofluorimetric characterization of oils have been in use during exploitation of the marine fleet, i.e. lubricate oil, fuels, transformer and hydraulic oils as well as crude oils or their residues. Every kind of oil has a chance to enter the marine environment, especially in a case of ship emergency or after collision with other vessel ore shoreline structure as well as when ship enters the stranding. After discharge of oil, some of oil components are dissolved in the water, bacteria or photochemical reactions, which results in transformation of composition of oil, degrade some. Fluorescence spectrometer Perkin Elmer LS55 was applied to obtain the fluorescence spectra using different excitation wavelength in the range from 240 nm to 500 nm. We discuss the changes of the shapes of excitationemission spectra (EEMs) of various types of oil and the EEMs spectra after contact of oil with seawater as an oil-inwater emulsion, which is the most frequent form of oil in the water column. Significant changes in the shape of spectra and displacement of the peaks are observed.
EN
Porous carbons obtained from poly(ethylene terephtalate) contained in a mixture with either MgCO3 or Mg(OH)2 were examined as adsorbents for removal of humic acid from water. Adsorption of the model contaminants is discussed in relation to the textural parameters of the obtained carbon materials. Pore structure parameters of the carbonaceous materials were strongly influenced by preparation conditions including temperature and relative amounts of the inorganics used during preparations as template. Porous carbons prepared revealed a potential to purify water from the model contaminant of high molecular weight. The results presented confirmed a key role of mesoporosity in the adsorption of humic acid. Fluorescence spectroscopy was confirmed to be an useful method to evaluate concentration of humic acid in water.
PL
Badania dotyczyły analizy właściwości substancji humusowych (SH) oraz kształtowania struktury kwasów huminowych (KH) gleb po wprowadzeniu preparatu wytworzonego na bazie (85%) odpadowego węgla brunatnego. Do badań wykorzystano materiał glebowy z wieloletnich statycznych doświadczeń polowych i mikropoletkowych, a jako źródło materii organicznej Rekulter preparat wyprodukowany na bazie węgla brunatnego odpadowego i węgla brunatnego typu ziemistego z Zagłębia Konińskiego (KWB Konin). Niższe wartości intensywności fluorescencji na widmach 3-D EEM dla KH z gleby rdzawej (piaszczystej) wskazują na większy wpływ materii organicznej z węgla brunatnego na gleby bardzo lekkie piaszczyste w porównaniu do gleb cięższych (brunatna kwaśna, płowa). Wyniki ponad 20-letnich doświadczeń polowych na glebie rdzawej potwierdziły korzystne, długotrwałe oddziaływanie węgla brunatnego na właściwości gleby oraz na stan materii organicznej z tego źródła.
EN
Soil is non-renewable and a very complex natural resource which performs many vital functions: food (99%) and other biomass production, storage, filtration and transformation of many substances including water, carbon, nitrogen. Soil as a top layer of the earth's crust is the first receiver of anthropogenic contaminants, and may or may not serve as a natural barrier to protect groundwater against contamination from the surface. One of the most important indicators of soil quality is soil organic matter (SOM), which is an important building block for the soil structure, formation of stable aggregates, and is able to improve the infiltration rates and the storage capacity of water. SOM presents a major pool carbon in the biosphere and can act both as a source and sink for carbon dioxide and other greenhouse gases. Agricultural intensification and cultivation in general results in a serious decrease in SOM as compared to that in the natural vegetation. Presently, the protection of SOM is one of the main tasks in EU, because SOM in addition to its soil fertilizing function can act in the elimination of the soil contamination and carbon sequestration. In this context, humic substances (especially humic and fulvic acids) and cohesive fractions (clay, silt, silt clay, etc.) present in soil are favourable components. It is because of their high sorption capacity with respect to many contaminants, including heavy metals, which may results in their immobilisation and, consequently protect groundwater against contamination. Antropogenically transformed soils often do not contain humic substances (HS), thus their role as a natural barrier is decreased. Therefore, re-generation of HS through humification of organic matter from diverse sources added to soils, may be the way to re-built the protective character of soil barrier, and consequently to reduce environmental and/or health risks at areas under anthropopression. Transformation processes of brown coal applied to soil were described to evaluate the use of this material as an effective source of organic matter and HS generation in degraded soils. The goal of this study was to discuss fine brown coal derived preparation as effective sources of organic matter (and humic substances) especially in soils that are anthropogenically transformed. The research concerned the analysis of properties of HS as well as formations of humic acids (HAs) in soils after addition brown coal. Soil materials used in the research was collected from the long term field experiments and microplots, as the source of organic matter the Rekulter that is based (85%) on brown coal (soft smudge type) obtained from the Konin Basin deposits preparation was used. For qualitative characteristic of SOM, particularly, in HAs, modern analytical technique such as fluorescence intensity (FI) for 3-D EEM spectra was used. The lowest fluorescence intensity (FI) for 3-D EEM spectra were observed in the case of HAs extracted from rusty soil. The 20-years research results carried out on rusty soil (sandy) confirmed long-term effect of brown coal on soil properties as well as on organic matter that originated from this source.
PL
W pracy przedstawiono możliwości klasyfikacji paliw płynnych za pomocą spektroskopii ptycznej. Paliwa analizowano za pomocą trzech technik. Spektroskopia FTIR umożliwiła rozróżnianie pomiędzy typami paliw oraz oznaczenie ich składu. Benzyny 95 i 98 pochodzące z rafinerii Orlen wyraźnie różnią się od swoich odpowiedników z innych wytwórni. Mapy wzbudzeniowo-emisyjne wykazały różnice pomiędzy typami paliw lecz nie umożliwiała rozróżniania pomiędzy Pb 95 i 98. Fluorescencja czasowo-rozdzielcza, przy wzbudzeniu promieniowaniem o długości fali 28O nm pozwoliła na wyraźne odróżnienie pomiędzy różnymi typami paliw.
EN
The manuscript presents application of optical spectroscopy for classification of liquid fuels. Three analytical techniques were used for analysis of fuels. FTIR spectroscopy allows determination of chemical composition and discrimination between different kinds of fuels. Biofuels, diesel, petrol 95 and 98 Orlen were grouped separately on the background of other Pb95 and Pb98. Excitation-emission maps of steady-state fluorescence showed differences between spectra. but petrol 95 and 98 were similar. Time-resolved fluorescence, with excitation wavelength at 280 nm allowed sharp discrimination between different kinds of fuels Chosen optical methods may allow identify and classify liquid fuels.
PL
Od wielu lat z postępem w dziedzinie fizyki związany jest postęp w naukach przyrodniczych. Jednym ze zjawisk, które odgrywa coraz większą rolę w naukach przyrodniczych, jest zjawisko generacji drugiej harmonicznej w ośrodkach anizotropowych. Możliwość uzyskania fali o podwojonej częstotliwości w stosunku do fali podstawowej pozwoliło na prowadzenie badań, wcześniej trudnych bądź niemożliwych do przeprowadzenia. Dzięki wyższej jakości obrazu badania ultrasonograficzne stały się bardziej czułe i są powszechnie wykorzystywane, m.in. w kardiologii, radiologii, chirurgii, reumatologii czy diagnostyce onkologicznej. Ultrasonografia staje się niezwykle cenioną metodą obrazowania obok rezonansu magnetycznego czy tomografii komputerowej. Ze względu na jej dostępność wiązane są z nią duże nadzieje na przyszłość.
EN
The progress in physics results in life sciences advancement. One of the phenomena, which plays more and more important role in life sciences, is the second harmonic generation in anisotropic materials. The possibility of achieving the wave, characterized by double frequency – with relation to the initial wave, allowed to conduct examinations, which were previously very difficult or impossible to perform. Thanks to higher quality of image, ultrasound examination has become more sensitive and is widely used, even in cardiology, radiology, surgery, rheumatology and oncology diagnostics. Ultrasonography with the use of tissue harmonic imaging is very valued method, so as magnetic resonance imaging or CT scan and due to its availability, high expectations are associated with it for the future.
EN
The interaction between buckminsterfullerene C60 and humic acids (HA) of different origins was compared using fluorescence spectroscopy as a function of pH, humic acid concentration, ionic strength. Binding constants between fullerene and humic acids were calculated. It can be suggested that the complexation was driven by hydrophobic interactions depending on the properties of the interacting compounds. Hydrophobic interaction model as indicated by linear Stern-Volmer plots and high Kd values is characterizing the interaction between buckminsterfullerene C60 and humic acids The results of this study support the development of understanding of the fate of nanomaterials in the environment as well as the development of analytical methods for nanomaterials in waters and wastewater treatment approaches.
PL
Porównywano oddziaływania między buckminsterfulerenami C60 i kwasami huminowymi (HA) różnego pochodzenia w zależności od pH, stęzenia kwasów huminowych i siły jonowej. Do badań stosowano spektroskopię fluorescencyjną. Obliczono stałe trwałości związków kwasów huminowymi i fulerenów. Można przypuszczać, że kompleksowanie jest powodowane oddziaływaniami hydrofobowmi, zależnymi od właściwości związków. Model interakcji hydrofobowych wskazanych przez liniowe zależności Sterna-Volmera i duże wartości Kd charakteryzują interakcje między buckminsterfulerenami C60 i kwasami huminowymi. Wyniki opisanych badań są ważne dla poznania losu nanomateriałów w środowisku, a także dla rozwoju metod analizy zawartości nanomateriałów w wodach oraz metod oczyszczania ścieków.
EN
Meso-substituted unsymmetrical porphyrin liquid crystal, 5-(p-palmitoyloxy phenyl)phenyl-10,15,20-triphenyl porphyrin (PPTPPH2) and relative transition metal complexes (PPTPPM, M = Zn, Co, Mn, Cu, FeCl) were synthesized and characterized by means of elemental analysis, UV-Vis, IR, MS and 1H NMR spectroscopies. Further more, the thermal stabilities and fluorescence spectroscopy of these complexes were investigated. The liquid crystal properties were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The results reveal that the PPTPPH2 shows liquid crystalline behavior with more than one mesophase and it has a low-lying phase transition temperature, which changes from 3.9 to 73.5°C.
EN
The binding of cytidine-5’-monophosphate (CMP) to human serum albumin (HSA) was investigated by fluorescence spectroscopy in combination with molecular modeling under simulation of physiological conditions. The quenching mechanism was suggested to be static according to the fluorescence measurement. The thermodynamic parameters: enthalpy change (DeltaH) and entropy change (DeltaS) were calculated to be –5.09 kJ/mol and 73.00 J mol–1 K–1 according to the Vant’Hoff equation. These data suggest that hydrophobic inter actions are the predominant intermolecular forces stabilizing the complex. Experimental results are in agreement with the results obtained by molecular modeling study. In addition, the effects of commonions on the binding constants were also studied at room temperature.
19
Content available remote Aktywność katalityczna pojedynczych cząsteczek enzymów
EN
As early as in 1961, it has been demonstrated that turnovers of individual enzyme molecules can be detected [1]. In the nineties, advances in single-molecule methods, in particular in confocal microscopy (Fig. 1), made it possible to monitor more closely enzymatic turnovers at a single-molecule level [2-5]. This led to the discoveries of static disorder and dynamic disorder, and closely related memory effects in enzymatic turnovers [6-8]. Differences in activity of individual molecules of the same enzyme are called static disorder. Time-dependent fluctuations of enzymatic activity are called dynamic disorder. One manifestation of dynamic disorder is the fact that consecutive enzymatic turnovers are not statistically independent, which is called "memory effect". It is believed that static dis-order and dynamic disorder are related to conformational dynamics of enzyme molecules. In this review we discuss current issues of single-molecule enzymology, in particular kinetic effects that are specific to single-enzyme measurements. First we review the conceptual basis of single-enzyme kinetics and the initial work on single enzymes. We focus on the ping-pong mechanism of bisubstrate enzyme reactions (Eqs. (1) and (2)), and consider fluorescence trajectories (Figs. 2 and 3) associated with enzymatic turnovers. Two cases are distinguished. In the first, fluorescence comes from an enzyme molecule and fluorescence intensity jumps called blinking carry information on enzymatic activity. Jumps between a fluorescent (on) and non-fluorescent (off) states (Eqs. (4), (5), and Fig. 2) indicate the moments when the photophysical state of an enzyme changes during enzymatic turnovers. In the second case, fluorescence comes from product molecules whereas enzyme and substrate are non-fluorescent. Fluorescence bursts on a trajectory indicate the moments when non-fluorescent substrate molecules are converted into fluorescent product molecules that subsequently diffuse away from the detection volume (Eqs. (8), (9) and Fig. 3). In Section 1 we present selected experiments implying the effect of conformational dynamics on enzymatic kinetics. In Section 1.1, we discuss cholesterol oxydase and dihydroorotate dihydrogenase as examples of enzymes whose on-off fluorescence blinking is caused by chemical reactions at the enzyme active site. In Section 1.2 we discuss ?-lactosidase and lipase B as enzymes which turnovers can generate fluorescent products from suitably chosen non-fluorescent substrates. In Section 2, we review modeling and simulations of single-enzyme data. The aim of data modeling is to gain insight into single-enzyme activity through analysis of models of increasing complexity. Phenomenological models attempt to capture the essence of single-enzyme kinetics without going into molecular details. If a model is simple enough it may allow analytical solutions. For instance, a simple model of on-off blinking is given in Scheme (25). This scheme is capable of reproducing memory effect that can be visualized by a two-dimensional histogram of consecutive on and off times (Figs. 5a and 5b). Finally, in the last section we present an outlook for single-molecule enzymology.
EN
Single particle fluorescence spectroscopy coupled with AFM observation is reported for perylene nanocrystals. Fluorescence spectral measurement for individual nanocrystals with the size from 100 nm to 500 nm and fluorescence anisotropy analysis demonstrate that the size dependence in fluorescence is in the intrinsic nature of nanometer-sized crystal of perylene. Single nanoparticle fluorescence shows the enhanced monomer (M-) emission compared to the bulk crystal and a blue-shift of excimer (E-) emission peak wave length by decreasing the nanoparticle size. It is found for the first time that the size dependence is correlated well to the surface-to-volume ratio of nanocrystal. The size-dependent fluorescence is not attributed to a quantum confinement effect of exciton, but to a change in the elastic properties of nanocrystal with size, which in turn affects excimer formation. We discuss the decrease in elastic constant of crystal-line lattice due to large surface-to-volume ratio, and propose an empirical formula on the size-dependence of E-emission peak in the framework of the strong coupling model of exciton-phonon interaction.
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