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Tytuł:
Wzmocnienie sygnału magnetycznego rezonansu jądrowego metodami hiperpolaryzacji jądrowej ze szczególnym uwzględnieniem hiperpolaryzacji indukowanej parawodorem
Nuclear magnetic resonance signal enhancement by hyperpolarization methods with particular focus on parahydrogen induced polarization
Autorzy:
Jopa, Sylwia
Mames, Adam
Ratajczyk, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/2200435.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
NMR
NMR sensitivity
hyperpolarization
parahydrogen
czułość NMR
hiperpolaryzacja
parawodów
Opis:
Nuclear Magnetic Resonance based methods are currently being widely utilized in many fields of science, medicine, and industry. The impressive amount of success that has been made with NMR has been possible because an enormous effort has been expended to improve the low level of NMR sensitivity. However, the issue of low NMR sensitivity is still a serious problem, and NMR still cannot be utilized in many important cases where the concentrations of NMR active species are low-this is why the boosting of the NMR signal is currently one of the most important research fields in the NMR area. Here, the problem of low NMR sensitivity is discussed through the presentation of methodologies aimed at increasing NMR sensitivity and their novel applications. First, a short general overview of the NMR and its sensitivity problem will be presented. Having clearly identified the problem, the main technologies that will be utilized for the improvement of NMR sensitivity will be introduced. First, we will concisely, and with appropriate references, present methodologies that can increase NMR sensitivity via the design of novel superconducting magnets, the application of cryotechnology for the design of noiseless probe heads, and other hardware and software approaches. Next, the most promising and powerful method for NMR signal enhancement which is known as hyperpolarization will be discussed. First, noble gas hyperpolarization and CIDNP will be briefly presented. We will describe the basic mechanism and applications of these methods. Next, our attention will be paid to the DNP approach, and the origin and applications of the DNP effect will be presented, in particular from the point of view of its utilization in medical diagnostics and material sciences. The most extensive part of our discussion will be devoted to the parahydrogen-based methods, which include hydrogenable Parahydrogen Induced Polarization and Signal Amplification by Reversible Exchange. In the introduction to these methods, the properties of hydrogen molecules, which are the main driving forces of PHIP, will be presented. The mechanism of the boosting of NMR signals will be presented for hPHIP and SABRE. The application of these methods will be presented, with the central focus being on their applications in catalysis and medical diagnostics. In the context of medical applications, the hyperpolarization of biorelevant molecules will be presented. Finally, a summary and future prospects for the development of methods of NMR signal enhancement, particularly in the context of hyperpolarization, will be discussed.
Źródło:
Wiadomości Chemiczne; 2022, 76, 11-12; 912--942
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromatograficzna analiza związków budujących kwasy nukleinowe
Chromatographic analysis of nucleic acids constituents
Autorzy:
Studzińska, S.
Rola, R.
Łobodziński, F.
Krzemińska, K.
Powiązania:
https://bibliotekanauki.pl/articles/172180.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
nukleozydy
nukleotydy
oligonukleotydy
chromatografia cieczowa
czułość
selektywność
nucleosides
nucleotides
oligonucleotides
liquid chromatography
sensitivity
selectivity
Opis:
Understanding the characteristics, role and structure of nucleic acids allowed to answer questions about the disease processes. Today, nucleic acids and their constituents are tools, which are used by molecular biology in medicine and biotechnology. Antisense and gene therapy are intensively developing methods for possible treating or preventing disease. They use short fragments of DNA or RNA - oligonucleotides to silence the genes expression. They are not the only ones that allow analytical chemists to obtain information about the state of our body. Determination of modified nucleoside allows detection of cancer, while analysis of nucleotides allows the estimation of strengthening the immune system. There is a great need of sensitive, selective and precise methods of separation of nucleosides, nucleotides and oligonucleotides and their qualitative and quantitative analysis. Consequently liquid chromatography (LC) is the most commonly used for analysis of nucleic acid constituents. The most widely used modes of LC include Ion Exchange Chromatography (IEC) and Reversed Phase High Performance Liquid Chromatography (RP HPLC). Both techniques have their advantages and disadvantages in the analysis of nucleosides, nucleotides and oligonucleotides. In the case of IEC it is necessary to use high concentrations of the salt in the mobile phase or concentration gradients, which considerably limits the possibility of using MS detection. RP HPLC can be coupled with MS detection but only when volatile salts are mobile phase components. On the other hand there is a significant problem is the lack of sufficient selectivity for the most polar nucleosides and nucleotides. RP HPLC MS is still most often used in the determination of nucleosides and nucleotides, due to its high sensitivity and a comprehensive qualitative analysis. Another system used for the HPLC analysis of oligonucleotides is Ion Pair Reversed Phase High Performance Liquid Chromatography (IP RP HPLC). These compounds can not be analyzed by RP HPLC due to their high polarity. The advantage of IP RP HPLC is selectivity, achieved by a suitable choice of mobile phase composition and the possibility of using MS. A disadvantage of IP RP HPLC in the analysis of oligonucleotides is however lower sensitivity compared to RP HPLC. During the last few years Hydrophilic Interaction Liquid Chromatography (HILIC) was applied for the separation of mixtures of nucleosides, nucleotides, oligonucleotides extracted from a biological or food samples. The presented results demonstrate the usefulness of this method, however, the resolving power is limited due to the asymmetric peak shape. On the other hand proper selection of the mobile and stationary phase can lead to a high selectivity in the analysis of the most polar nucleosides, nucleotides and oligonucleotides, which can not be separated by RP HPLC.
Źródło:
Wiadomości Chemiczne; 2016, 70, 9-10; 633-656
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
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