The effects of a type I AFP on the bulk melting of frozen AFP solutions and frozen AFP+solute solutions were studied through an NMR microimaging experiment. The solutes studied include sodium chloride and glucose and the amino acids alanine, threonine, arginine, and aspartic acid. We found that the AFP is able to induce the bulk melting of the frozen AFP solutions at temperatures lower than 0 °C and can also keep the ice melted at higher temperatures in the AFP+solute solutions than those in the corresponding solute solutions. The latter shows that the ice phases were in super-heated states in the frozen AFP+solute solutions. We have tried to understand the first experimental phenomenon via the recent theoretical prediction that type I AFP can induce the local melting of ice upon adsorption to ice surfaces. The latter experimental phenomenon was explained with the hypothesis that the adsorption of AFP to ice surfaces introduces a less hydrophilic water-AFP-ice interfacial region, which repels the ionic/hydrophilic solutes. Thus, this interfacial region formed an intermediate chemical potential layer between the water phase and the ice phase, which prevented the transfer of water from the ice phase to the water phase. We have also attempted to understand the significance of the observed melting phenomena to the survival of organisms that express AFPs over cold winters.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3532670 | PMC |
http://dx.doi.org/10.1007/s10867-012-9291-7 | DOI Listing |
BMC Genomics
January 2025
College of Forestry and Grassland, Nanjing Forestry University, Nanjing, 210037, China.
Cold stress in winter is one of the most severe abiotic stresses on plant growth and flourishing, and the selection of cold tolerant genotypes is an important strategy to ensure the safety of plant growth and development. Cyclocarya paliurus, a diclinous and versatile tree species originally in subtropical regions, has been introduced and cultivated in the warm temperate zone of China to meet the increasing market demand for its leaf yield. However, information regarding its cold tolerance remains limited.
View Article and Find Full Text PDFSci Rep
January 2025
School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, USA.
Cryoprotective agent (CPA) toxicity is the most limiting factor impeding cryopreservation of critically needed tissues and organs for transplantation and medical research. This limitation is in part due to the challenge of rapidly screening compounds to identify candidate molecules that are highly membrane permeable and non-toxic at high concentrations. Such a combination would facilitate rapid CPA permeation throughout the sample, enabling ice-free cryopreservation with minimal toxicity.
View Article and Find Full Text PDFSci Rep
January 2025
The Fourth Engineering Co., LTD, China Railway Fourth Bureau, Hefei, 230012, People's Republic of China.
Research investigating the complex mechanical properties and energy evolution mechanisms of frozen calcareous clay under the influence of multiple factors is crucial for optimizing the artificial ground freezing method in shaft sinking, thereby enhancing construction quality and safety. In this study, a four-factor, four-level orthogonal test was devised, taking into account temperature, confining pressure, dry density, and water content. The complex nonlinear curvilinear relationship between deviatoric stress, volume strain, and axial strain of frozen calcareous clay under different interaction levels was analyzed.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mining and Geological Engineering, University of Arizona, Tucson, AZ, 85721, USA.
The thermodynamic properties of frozen soil depend on its temperature state and ice content. Additionally, the permeability coefficient significantly affects both the temperature distribution and water movement. In this study, the dynamic variation of soil permeability coefficient with temperature is considered, the permeability coefficient is defined as a piecewise function with temperature as independent variable, and the hydrothermal coupling equation is established.
View Article and Find Full Text PDFEur J Pharm Sci
January 2025
Ludwig-Maximilians-Universität München, Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, 81377 Munich, Germany. Electronic address:
The frozen storage of biopharmaceuticals brings new challenges to the primary packaging material. Due to an increasing demand and the downsides of standard type I glass vials, such as vial breakage, novel vial types for special applications of parenteral drug products have been introduced to the market in the past years. Mechanical stresses due to dimensional changes experienced during freezing and thawing could change the material properties, hence affecting the interaction with the drug product stored in the vial or functionality such as overall integrity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!