Background: The contribution of the sarcomere's thin filament to the contractile dysfunction of human cardiomyopathy is not well understood.
Methods And Results: We have developed techniques to isolate and functionally characterize intact (native) thin filaments obtained from failing and nonfailing human ventricular tissue. By use of in vitro motility and force assays, native thin filaments from failing ventricular tissue exhibited a 19% increase in maximal velocity but a 27% decrease in maximal contractile force compared with nonfailing myocardium. Native thin filaments isolated from human myocardium after left ventricular assist device support demonstrated a 37% increase in contractile force. Dephosphorylation of failing native thin filaments resulted in a near-normalization of thin-filament function, implying a phosphorylation-mediated mechanism. Tissue expression of the protein kinase C isoforms alpha, beta1, and beta2 was increased in failing human myocardium and reduced after left ventricular assist device support.
Conclusions: These novel findings demonstrate that (1) the thin filament is a key modulator of contractile performance in the failing human heart, (2) thin-filament function is restored to near normal levels after LVAD support, and (3) the alteration of thin-filament function in failing human myocardium is mediated through phosphorylation, most likely through activation of protein kinase C.
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http://dx.doi.org/10.1161/01.CIR.0000139334.43109.F9 | DOI Listing |
J Phys Chem Lett
December 2024
School of Electronic Science and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.
NiO is a wide-bandgap p-type metal oxide that has extensive applications in optoelectronics and photocatalysts. Understanding the carrier dynamics in p-type NiO is pivotal for optimizing device performance, yet they remain largely unexplored. In this study, we employed femtosecond transient absorption spectroscopy to delve into the dynamics of photogenerated carriers in NiO films containing distinct prominent native defects: undoped NiO with oxygen vacancies () and O-rich NiO (denoted as NiO) with nickel vacancies ().
View Article and Find Full Text PDFJ Nat Prod
December 2024
Dipartimento di Scienze del Farmaco, Largo Donegani 2, 28100 Novara, Italy.
The optical purity of cannabichromene (CBC, ) is affected by the matrix in which it is generated by thermolysis from its native carboxylated form (cannabichromenic acid, CBCA, ). Thus, thermolysis at 130 °C caused a marked decrease of the enantiomeric excess (ee), while, under the same conditions, only a modest decrease of optical purity was observed when thermolysis was carried out . To rationalize these puzzling observations, the kinetics of thermal (100 °C) racemization of enantiopure cannabichromene () was evaluated by enantioselective ultrahigh performance liquid chromatography in solvents (decalin and isopropyl alcohol, neat and acidified with TFA) and surfaces (native and silanized borosilicate glass) of complementary polarity.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
November 2024
Graduate School of Chemical Engineering, Dongguk University, Seoul 04620, Republic of Korea; Department of Chemical and Biochemical Engineering, Dongguk University, Seoul 04620, Republic of Korea. Electronic address:
The bioinspired synthesis of virus-like silica nanoparticles in biomedical applications makes it possible to utilize the cellular delivery capabilities of viruses while minimizing the cytotoxicity of inorganic silica. In this study, we developed a diatom-inspired method for synthesizing silica-layered nanocages utilizing R5 peptide-functionalized virus-like particles (VLPs). R5 peptides were genetically inserted into the F-G loop of human papillomavirus 16 L1 proteins (HPV16 L1-R5).
View Article and Find Full Text PDFAnal Bioanal Chem
November 2024
Swiss Centre for Applied Ecotoxicology, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Many chemicals in food packaging can leach as complex mixtures to food, potentially including substances hazardous to consumer health. Detecting and identifying all of the leachable chemicals are impractical with current analytical instrumentation and data processing methods. Therefore, our work aims to expand the analytical toolset for prioritizing and identifying chemical hazards in food packaging.
View Article and Find Full Text PDFMetallomics
December 2024
The SR Center, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
The shell color of Corbicula clams, which are globally distributed, is roughly divided into yellowish and blackish depending on the environmental conditions of the sediment. The formation of an iron-L-3,4-dihydroxyphenylalanine (DOPA) complex in a thin organic layer, called the periostracum, on a calcareous layer causes the blackening of the clamshell. However, the iron-DOPA complex formation mechanism is unclear.
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