Equilibrium melting curves were obtained for triplexes, formed by single stranded DNA containing an A10 target with bis-PNA consisting of two T10 decamers. Thermodynamic parameters of melting were determined for Na(+) concentrations 50, 200 and 600mM by two methods. The melting enthalpy Delta H degrees was evaluated from the width of the differential melting curves and from the concentration dependence of the melting temperature. The latter method allowed also evaluating the melting entropy Delta S degrees. The following results were obtained: Delta H degrees = - 137 kcal/M, Delta S degrees = - 368 cal/M.K, Delta G degrees (298)= - 27 kcal/M. No dependence of Delta H degrees, Delta S degrees and Delta G degrees (298) was observed upon ionic strength within the accuracy of the experiment (+/- 10%). The absolute values of Delta H degrees, Delta S degrees and Delta G degrees(298) are 2 to 3 times higher than the published values of corresponding melting parameters for decameric PNA/DNA duplexes of various nucleic base sequences. The origin of the extremely high stability of the triplexes is discussed.
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http://dx.doi.org/10.1080/07391102.2001.10506761 | DOI Listing |
J Fish Biol
January 2025
Chair of Hydrobiology and Fisheries, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia.
The annual flood pulse is a defining feature of Amazonian floodplain lakes, creating a highly variable environment that influences resource availability, such as food and habitat. These cyclical changes necessitate a high degree of adaptability among fish species, many of which have evolved specialized strategies to cope with the fluctuating conditions. In 2023, the Amazon basin experienced a record-breaking drought event, leading to mass mortality of Amazonian fish and other wildlife.
View Article and Find Full Text PDFFood Sci Technol Int
January 2025
College of Food Science and Engineering, Shandong Agricultural University, Tai'an, China.
The objective of this study was to investigate the water-holding capacity (WHC) and quality changes of beef during heating at specific temperatures (including 40 °C, 60 °C, 80 °C, and 100 °C), as well as the degradation of proteins and the distribution of water within the muscle at different heating temperatures. The experiment utilized the sirloin section from eight crossbred cattle of and breeds, with four sampling sessions, two cattle per session. Each cattle were divided into 30 beef sirloin samples, each weighing 150 ± 10 g, and each session was completed within 3 days with the following tests.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Engineering Research Center of Membrane and Water Treatment of MOE, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
Polyamide (PA) membranes are widely utilized in desalination and water treatment applications, yet the mechanisms underlying water transport within these amorphous polymer materials remain insufficiently understood. To gain more insight into these problems on a microscopic scale, we employ molecular dynamics (MD) simulations to analyze the relationship between the structural properties and the water permeation behavior of PA membranes. Two distinct atomistic models of PA membranes are developed by controlling their degrees of cross-linking (DC).
View Article and Find Full Text PDFJ Cogn Neurosci
January 2025
National Central University, Taoyuan City, Taiwan.
Pitch variation of the fundamental frequency (F0) is critical to speech understanding, especially in noisy environments. Degrading the F0 contour reduces behaviorally measured speech intelligibility, posing greater challenges for tonal languages like Mandarin Chinese where the F0 pattern determines semantic meaning. However, neural tracking of Mandarin speech with degraded F0 information in noisy environments remains unclear.
View Article and Find Full Text PDFInfect Dis Now
January 2025
Department of Infectious Diseases, University Hospital of Angers, 4 rueLarrey, 49933 Angers, Cedex 9, France.
Background: Computed tomography (CT) is a critical tool for the diagnosis of pneumonia caused by SARS-CoV-2. The Delta and Omicron variants show distinct clinical features, but the radiological differences between pneumonia caused by these variants have not been extensively studied in patients with oxygen-dependent pneumonia.
Objective: To compare the radiological and clinical features of pneumonia in patients hospitalized with oxygen-dependent SARS-CoV-2 infection caused by the Delta and Omicron variants.
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