Home  About us  Contact
 

Melting Curve (melting + curve)

Distribution by Scientific Domains
Chemistry83%

Terms modified by Melting Curve

  • melting curve analysis
    		•

    Selected Abstracts

    Photocleavage of Peptides and Oligodeoxynucleotides Carrying 2-Nitrobenzyl Groups

    HELVETICA CHIMICA ACTA, Issue 4 2009
    Roger Ramos
    Abstract Peptides and oligodeoxynucleotides containing photolabile 2-nitrobenzyl groups as mid-sequences were prepared. Photocleavage of aqueous solutions of these compounds neared completion within 30,min to a few hours depending on the photolabile group used. A photolabile group was introduced in the loop of an intramolecular oligodeoxynucleotide hairpin. Melting curves of the hairpin with and without the complementary oligodeoxynucleotide showed a preference for the intramolecular hairpin form, but an intermolecular duplex was observed after photolysis. These results open the possibility of using photolabile DNA hairpins for the fabrication of patterned surfaces. [source]

    Real Time Electrochemical Monitoring of DNA/PNA Dissociation by Melting Curve Analysis

    ELECTROANALYSIS, Issue 14 2009
    Xiaoteng Luo
    Abstract An immobilization-free electrochemical method is reported for real-time monitoring of the DNA hybrid dissociation between a ferrocene labeled peptide nucleic acid (PNA) and a fully-complementary or single-base-mismatched DNA. This method takes advantages of electrostatic charge characteristics and interactions among the neutrally charged PNA, the negatively charged DNA and the negatively charged electrode surface made of indium tin oxide (ITO). When a ferrocene labeled PNA (Fc-PNA) sequence is hybridized to a complementary DNA strand, electrostatic repulsion between the negatively charged PNA/DNA hybrid and the negative ITO surface retards the diffusion of the electroactive Fc to the electrode, resulting in a much reduced electrochemical signal. On the other hand, when the Fc-PNA is dissociated from the hybrid at elevated temperatures, the neutrally charged Fc-PNA easily diffuses to the electrode with an enhanced electrochemical signal. Therefore, an electrochemical melting curve of the Fc-PNA/DNA hybrid can be obtained by measuring the Fc signal with the increasing temperature. This strategy allows monitoring of the dissociation of the DNA hybrid in real time, which might lead to a simple detection method for single nucleotide polymorphism (SNP) analysis. [source]

    Quantum statistics of charged particles and fingerprints of wigner crystallization in D dimensions

    INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 15 2006
    N. H. March
    Abstract After a brief summary of the physical arguments underlying Wigner's original concept in 1934 of a quantal electron crystal, theoretical interpretation of a number of experimental findings are presented. These include (i) low-density carriers in semiconductors in applied magnetic fields in both three, and recently two, dimensions; and (ii) low-temperature phase diagram of underdoped high Tc cuprates; fullerides with relatively low Tc are also referred to in a related context. Interpretation of areas (i) and (ii) focuses on the relevance of both Fermi,Dirac and anyonic (fractional) statistics, the latter in relation to the proposed melting curve of the two-dimensional (2D) magnetically induced Wigner solid into the Laughlin liquid phase, which is the seat of the fractional quantum Hall effect. A brief discussion follows of crystalline phases additional to the Wigner solid, namely Skyrmion and Hall crystals. Bose,Einstein statistics is then referred to, but now in relation to finite-size confined quantal assemblies, with fingerprints of Wigner molecules the focus. Finally, quasi-1D lattices are considered, both in Bechgaard salts and in the very recent single-electron counting experiment of Bylander et al. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source]

    Liquid,liquid miscibility gaps and hydrate formation in drug,water binary systems: Pressure,temperature phase diagram of lidocaine and pressure,temperature,composition phase diagram of the lidocaine,water system

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2010
    René Ceolin
    Abstract The pressure,temperature (P,T) melting curve of lidocaine was determined (dP/dT,=,3.56,MPa,K,1), and the lidocaine,water system was investigated as a function of temperature and pressure. The lidocaine,water system exhibits a monotectic equilibrium at 321,K (ordinary pressure) whose temperature increases as the pressure increases until the two liquids become miscible. A hydrate, unstable at ordinary pressure, was shown to form, on increasing the pressure, from about 70,MPa at low temperatures (200,300,K). The thermodynamic conditions of its stability were inferred from the location of the three-phase equilibria involving the hydrate in the lidocaine,water pressure,temperature,mole fraction (P,T,x) diagram. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2756,2765, 2010 [source]

    Isofagomine Induced Stabilization of Glucocerebrosidase

    CHEMBIOCHEM, Issue 16 2008
    Gregory J. Kornhaber Dr.
    Abstract Structurally destabilizing mutations in acid ,-glucosidase (GCase) can result in Gaucher disease (GD). The iminosugar isofagomine (IFG), a competitive inhibitor and a potential pharmacological chaperone of GCase, is currently undergoing clinical evaluation for the treatment of GD. An X-ray crystallographic study of the GCase-IFG complex revealed a hydrogen bonding network between IFG and certain active site residues. It was suggested that this network may translate into greater global stability. Here it is demonstrated that IFG does increase the global stability of wild-type GCase, shifting its melting curve by ,15,°C and that it enhances mutant GCase activity in pre-treated N370S/N370S and F213I/L444P patient fibroblasts. Additionally, amide hydrogen/deuterium exchange mass spectroscopy (H/D-Ex) was employed to identify regions within GCase that undergo stabilization upon IFG-binding. H/D-Ex data indicate that the binding of IFG not only restricts the local protein dynamics of the active site, but also propagates this effect into surrounding regions. [source]

    Quantitative RT-PCR for the enumeration of noroviruses (Norwalk-like viruses) in water and sewage

    LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2004
    M.A. Laverick
    Abstract Aims:, Aims of investigation: (i) develop a quantitative RT-PCR for noroviruses and (ii) evaluate it on environmental samples. Methods and Results:, Noroviruses in environmental water samples were concentrated by adsorption/elution/flocculation. Sewage was processed by clarification and protein flocculation. Norovirus-specific cDNA produced by primer-directed reverse transcription of extracted RNA was amplified by LightCycler® and accumulation of product monitored by observation of fluorescence induced by the incorporation of SYBR Green. Absolute quantitation of product was achieved by construction of standard curves using quantitative standards produced by cloning a modified sequence of the 3,-region of the forward norovirus primer. Reaction specificity was confirmed by analysis of product melting curves. Conclusions:, Sewage was found to contain up to 1·8 × 106 norovirus cDNA copies per 100 ml and effluent contained up to 1·7 × 106 copies per 10 l. Marine bathing water and recreational river waters also contained noroviruses. Sample inhibition was detected to varying degrees in most sample types. Significance and Impact of the Study:, The study will enable quantitative comparisons be made of samples from different locations and treatment processes, and inform the debate on the revision of the EU Bathing Water Directive; it will have important implications for the analysis of samples derived from different aquatic matrices, and from foods. [source]