Procaryotic microorganisms accumulate several polymers in the form of intracellular inclusions as a strategy to increase survival in a changing environment. Such inclusions avoid osmotic pressure increases by tightly packaging certain macromolecules into the inclusion. In the present paper, a model describing changes in volume and density of the microbial cell as a function of the weight of the macromolecule forming the inclusion is derived from simple theoretical principles. The model is then tested by linear regression with experimental data from glycogen accumulation in Escherichia coli, poly-beta-hydroxybutyrate accumulation in Alcaligenes eutrophus, and sulfur accumulation in Chromatium spp. The model predicts a certain degree of hydration of the polymer in the inclusion and explains both the linear relationship between volume of the cell and weight of the polymer and the hyperbolic relationship between density of the cell and weight of the polymer. Other implications of the model are also discussed.
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http://dx.doi.org/10.1128/jb.164.2.749-756.1985 | DOI Listing |
J Mol Model
January 2025
Escuela Superior de Física y Matemáticas, IPN S/N, Edificio 9 de la Unidad Profesional "Adolfo López Mateos", Col. Lindavista, Alc. Gustavo A. Madero, 07738, Mexico City, Mexico.
Context: "Nanostructure of graphene-reinforced with polymethyl methacrylate" (PMMA-G), and vice versa, is investigated using its molecular structure, in the present work. The PMMA-G nanostructure was constructed by bonding PMMA with graphene nanosheet in a sense to get three different configurations. Each configuration consisted of polymeric structures with three degrees of polymerization (such as monomers, dimers, and trimers polymers, respectively).
View Article and Find Full Text PDFJ Anat
January 2025
Hannover Medical School, Institute of Functional and Applied Anatomy, Hannover, Germany.
Obesity, along with hypoxia, is known to be a risk factor for pulmonary hypertension (PH), which can lead to right ventricular hypertrophy and eventually heart failure. Both obesity and PH influence the autonomic nervous system (ANS), potentially aggravating changes in the right ventricle (RV). This study investigates the combined effects of obesity and hypoxia on the autonomic innervation of the RV in a mouse model.
View Article and Find Full Text PDFInt J Cardiovasc Imaging
January 2025
Cardiology Division, Montefiore Medical Center, Albert Einstein College of Medicine, 111 E 210st, Bronx, NY, USA.
Computed tomography (CT)-derived Epicardial Adipose Tissue (EAT) is linked to cardiovascular disease outcomes. However, its role in patients undergoing Transcatheter Aortic Valve Replacement (TAVR) and the interplay with aortic stenosis (AS) cardiac damage (CD) remains unexplored. We aim to investigate the relationship between EAT characteristics, AS CD, and all-cause mortality.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, China; College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China. Electronic address:
Mussel foot proteins (mfps) play important roles in surface interaction and underwater adhesion. However, limited production and the lack of adhesion of recombinant mfps have restricted their widespread use. Here, we present a general strategy for enhancing both the expression and function of mfps by connecting multiple protein fragments.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
January 2025
Department of Mechanical Engineering, Boston University, Boston, MA 02215, USA; Center for Multiscale and Translational Mechanobiology, Boston University, Boston, MA 02215, USA; Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
Despite the broad agreement that bone stiffness is heavily dependent on the underlying bone density, there is no consensus on a unified relationship that applies to both cancellous and cortical compartments. Bone from the two compartments is generally assessed separately, and few mechanical test data are available for samples from the transitional regions between them. In this study, we present a data-driven framework integrating experimental testing and numerical modeling of the human lumbar vertebra through an energy balance criterion, to develop a unified density-modulus relationship across the entire vertebral body, without the necessity of differentiation between trabecular and cortical regions.
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