The helix to coil transition of poly(L-glutamic acid) was investigated in 0.05 and 0.005 M aqueous potassium chloride solutions by use of potentiometric titration and circular dichroism measurement. Polymer concentration dependence of the transition was observed in the range from 0.006 to 0.04 monomol/e in 0.005 M KG1 solution. The polymer concentration dependence can be interpreted by current theories of the transition of charged polypeptides and of titration curves of linear weak polyelectrolytes taking the effect of polymer concentration into consideration.
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http://dx.doi.org/10.1016/0301-4622(75)80025-1 | DOI Listing |
Langmuir
January 2025
Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, 928 Second Street, Zhejiang, Hangzhou 310018, China.
Molecule-electrode interfaces play a pivotal role in defining the electron transport properties of molecular electronic devices. While extensive research has concentrated on optimizing molecule-electrode coupling (MEC) involving electrode materials and molecular anchoring groups, the role of the molecular backbone structure in modulating MEC is equally vital. Additionally, it is known that the incorporation of heteroatoms into the molecular backbone notably influences factors such as energy levels and conductive characteristics.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Sports Medicine of the Second Affiliated Hospital, and Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou 311113, China.
Joining heterogeneous materials in engineered structures remains a significant challenge due to stress concentration at interfaces, which often leads to unexpected failures. Investigating the complex, multiscale-graded structures found in animal tissue provides valuable insights that can help address this challenge. The human meniscus root-bone interface is an exemplary model, renowned for its exceptional fatigue resistance, toughness, and interfacial adhesion properties throughout its lifespan.
View Article and Find Full Text PDFActa Parasitol
January 2025
Genkök Genome and Stem Cell Center, Erciyes University, Talas, Kayseri, 38039, Türkiye.
Purpose: Encephalitozoon intestinalis is an obligate intracellular microsporidian fungus that causes severe gastrointestinal infections, particularly in immunocompromised individuals. Propolis (PROP), a resinous substance derived from bees, has antimicrobial, anti-inflammatory and antioxidant properties, while royal jelly (RJ) has immunomodulatory, antioxidant and antimicrobial activities. The aim of this study was to investigate the therapeutic potential of PROP and RJ against E.
View Article and Find Full Text PDFToxins (Basel)
January 2025
Multidisciplinary Agroindustry Research Laboratory, Carrera de Ingeniería en Construcción, Instituto de Ciencias Químicas Aplicadas, Universidad Autónoma de Chile, Talca 3460000, Chile.
Significant agro-industrial waste is produced during the winemaking process, including grape stalks, which are a rich source of the valuable biopolymer holocellulose that can be utilized for biotechnological processes. The purpose of this study was to delignify grape stalks in order to extract holocellulose. Then Lactobacillus plantarum (LP) was immobilized in the interstitial spaces of holocellulose and then coated with natural polymers (chitosan, Ch; and alginate, Al) to create the Holo-LP/Ch/Al complex.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Key Laboratory of Organic Integrated Circuit, Tianjin Key Laboratory of Molecular Optoelectronic Sciences & Ministry of Education, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China.
The exploitation of high-performance third-order nonlinear optical (NLO) materials that have a favorable optical limit (OL) threshold is essential due to a rise in the application of ultra-intense lasers. In this study, a Cu-based MOF (denoted as Cu-bpy) was synthesized, and its third-order NLO and OL properties were investigated using the Z-scan technique with the nanosecond laser pulse excitation set at 532 nm. The Cu-bpy exhibits a typical rate of reverse saturable absorption (RSA) with a third-order nonlinear absorption coefficient of 100 cm GW and a favorable OL threshold of 0.
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