Browse
Submit Data
Databases
API
Help

Dataset Information

13 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Coexistence of vitreous and crystalline phases of H₂O at ambient temperature.

ABSTRACT: Formation of vitreous ice during rapid compression of water at room temperature is important for biology and the study of biological systems. Here, we show that Raman spectra of rapidly compressed water at greater than 1 GPa at room temperature exhibits the signature of high-density amorphous ice, whereas the X-ray diffraction (XRD) pattern is dominated by crystalline ice VI. To resolve this apparent contradiction, we used molecular dynamics simulations to calculate full vibrational spectra and diffraction patterns of mixtures of vitreous ice and ice VI, including embedded interfaces between the two phases. We show quantitatively that Raman spectra, which probe the local polarizability with respect to atomic displacements, are dominated by the vitreous phase, whereas a small amount of the crystalline component is readily apparent by XRD. The results of our combined experimental and theoretical studies have implications for detecting vitreous phases of water, survival of biological systems under extreme conditions, and biological imaging. The results provide additional insight into the stable and metastable phases of H₂O as a function of pressure and temperature, as well as of other materials undergoing pressure-induced amorphization and other metastable transitions.

SUBMITTER: Shargh AK

PROVIDER: S-EPMC9271169 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Coexistence of fluid and crystalline phases of proteins in photosynthetic membranes.

Project description:Photosystem II (PSII) and its associated light-harvesting complex II (LHCII) are highly concentrated in the stacked grana regions of photosynthetic thylakoid membranes. PSII-LHCII supercomplexes can be arranged in disordered packings, ordered arrays, or mixtures thereof. The physical driving forces underlying array formation are unknown, complicating attempts to determine a possible functional role for arrays in regulating light harvesting or energy conversion efficiency. Here, we introduce a coarse-grained model of protein interactions in coupled photosynthetic membranes, focusing on just two particle types that feature simple shapes and potential energies motivated by structural studies. Reporting on computer simulations of the model's equilibrium fluctuations, we demonstrate its success in reproducing diverse structural features observed in experiments, including extended PSII-LHCII arrays. Free energy calculations reveal that the appearance of arrays marks a phase transition from the disordered fluid state to a system-spanning crystal. The predicted region of fluid-crystal coexistence is broad, encompassing much of the physiologically relevant parameter regime; we propose experiments that could test this prediction. Our results suggest that grana membranes lie at or near phase coexistence, conferring significant structural and functional flexibility to this densely packed membrane protein system.

| S-EPMC3762348 | biostudies-literature

Coexistence of structural and magnetic phases in van der Waals magnet CrI3.

Project description:CrI3 has raised as an important system to the emergent field of two-dimensional van der Waals magnetic materials. However, it is still unclear why CrI3 which has a ferromagnetic rhombohedral structure in bulk, changed to anti-ferromagnetic monoclinic at thin layers. Here we show that this behaviour is due to the coexistence of both monoclinic and rhombohedral crystal phases followed by three magnetic transitions at TC1 = 61 K, TC2 = 50 K and TC3 = 25 K. Each transition corresponds to a certain fraction of the magnetically ordered volume as well as monoclinic and rhombohedral proportion. The different phases are continuously accessed as a function of the temperature over a broad range of magnitudes. Our findings suggest that the challenge of understanding the magnetic properties of thin layers CrI3 is in general a coexisting structural-phase problem mediated by the volume-wise competition between magnetic phases already present in bulk.

| S-EPMC8560937 | biostudies-literature

Coexistence of phases in a protein heterodimer.

Project description:A heterodimer consisting of two or more different kinds of proteins can display an enormous number of distinct molecular architectures. The conformational entropy is an essential ingredient in the Helmholtz free energy and, consequently, these heterodimers can have a very complex phase structure. Here, it is proposed that there is a state of proteins, in which the different components of a heterodimer exist in different phases. For this purpose, the structures in the protein data bank (PDB) have been analyzed, with radius of gyration as the order parameter. Two major classes of heterodimers with their protein components coexisting in different phases have been identified. An example is the PDB structure 3DXC. This is a transcriptionally active dimer. One of the components is an isoform of the intra-cellular domain of the Alzheimer-disease related amyloid precursor protein (AICD), and the other is a nuclear multidomain adaptor protein in the Fe65 family. It is concluded from the radius of gyration that neither of the two components in this dimer is in its own collapsed phase, corresponding to a biologically active protein. The UNRES energy function has been utilized to confirm that, if the two components are separated from each other, each of them collapses. The results presented in this work show that heterodimers whose protein components coexist in different phases, can have intriguing physical properties with potentially important biological consequences.

| S-EPMC3411598 | biostudies-literature

Distinct skyrmion phases at room temperature in two-dimensional ferromagnet Fe3GaTe2.

Project description:Distinct skyrmion phases at room temperature hosted by one material offer additional degree of freedom for the design of topology-based compact and energetically-efficient spintronic devices. The field has been extended to low-dimensional magnets with the discovery of magnetism in two-dimensional van der Waals magnets. However, creating multiple skyrmion phases in 2D magnets, especially above room temperature, remains a major challenge. Here, we report the experimental observation of mixed-type skyrmions, exhibiting both Bloch and hybrid characteristics, in a room-temperature ferromagnet Fe3GaTe2. Analysis of the magnetic intensities under varied imaging conditions coupled with complementary simulations reveal that spontaneous Bloch skyrmions exist as the magnetic ground state with the coexistence of hybrid stripes domain, on account of the interplay between the dipolar interaction and the Dzyaloshinskii-Moriya interaction. Moreover, hybrid skyrmions are created and their coexisting phases with Bloch skyrmions exhibit considerably high thermostability, enduring up to 328 K. The findings open perspectives for 2D spintronic devices incorporating distinct skyrmion phases at room temperature.

| S-EPMC11021542 | biostudies-literature

Post-natal development of brown adipocytes in white fat: Phases independent and dependent of the ambient temperature

Project description:Decreased ambient temperature, from birth to weaning, significantly reduced fat mass (FM) and adiposity in developing mice. Changes in FM content in 10 day-old mice raised at 17°C were not accompanied by precocious induction of brown adipocytes in inguinal white adipose tissue (WAT). Brown phenotype was induced in 21 day-old mice independently of ambient temperature (17°C or 29°C) however the expression of Ucp1 and other brown fat biomarker genes was greater in animals raised at 17°C suggesting increased adaptive thermogenesis. Accordingly, we predict that the induction of brown adipocytes in WAT follows a strict developmental program and the number of potential brown adipocytes in WAT is determined genetically.

2015-05-03 | GSE62350 | GEO

EARLY FLOWERING3 sub-nuclear localization responds to changes in ambient temperature.

Project description: Not available

| S-EPMC8644450 | biostudies-literature

Coexistence of strongly buckled germanene phases on Al(111).

Project description:We report a study of structural and electronic properties of a germanium layer on Al(111) using scanning tunneling microscopy (STM), low energy electron diffraction and core-level photoelectron spectroscopy. Experimental results show that a germanium layer can be formed at a relatively high substrate temperature showing either (3×3) or (√7×√7)R±19.1° reconstructions. First-principles calculations based on density functional theory suggest an atomic model consisting of a strongly buckled (2×2) germanene layer, which is stable in two different orientations on Al(111). Simulated STM of both orientations fit nicely with experimental STM images and the Ge 3d core-level data decomposed into four components is consistent with the suggested model.

| S-EPMC5629377 | biostudies-literature

Crystalline-SiO2-Component-Induced Cracking in Coal Ash Deposits Exposed to Temperature Changes.

Project description:Frequent load changes or daily shut down and restarting have been imposed on thermal power plants in many areas to fill the gap between the demand for electric power and the variable outputs from renewable energy sources. These operations result in temperature changes in boiler furnaces, and the temperature changes may induce cracks in problematic coal ash deposits, which would contribute to their spontaneous shedding from heat-transfer surfaces. In this work, we microscopically investigated the origin of temperature-change-induced cracks in ash deposits. Analyses of the coal ash clinker generated in a utility boiler indicated that many cracks were generated close to the crystalline SiO2 components, such as quartz or cristobalite. To elucidate the impact of crystalline SiO2 components on the generation of cracks, we conducted temperature cycle tests for coal ash clinkers in an electric furnace. The results suggested that cracking was promoted by temperature changes that cover the transition temperature of crystalline SiO2 components. Moreover, we successfully demonstrated that the addition of quartz additives could promote the generation of cracks significantly in coal ash clinkers. The findings in this work will advance the cracking behavior in ash deposits during temperature changes. Factors for the propagation of cracks or other factors for the shedding should be discussed in further studies, which will contribute to developing a method for promoting the shedding of ash deposits during temperature changes caused by load changes or daily shut down and restarting of thermal power plants.

| S-EPMC9202278 | biostudies-literature

Dislocation "Bubble-Like-Effect" and the Ambient Temperature Super-plastic Elongation of Body-centred Cubic Single Crystalline Molybdenum.

Project description:With our recently developed deformation device, the in situ tensile tests of single crystal molybdenum nanowires with various size and aspect ratio were conducted inside a transmission electron microscope (TEM). We report an unusual ambient temperature (close to room temperature) super-plastic elongation above 127% on single crystal body-centred cubic (bcc) molybdenum nanowires with an optimized aspect ratio and size. A novel dislocation "bubble-like-effect" was uncovered for leading to the homogeneous, large and super-plastic elongation strain in the bcc Mo nanowires. The dislocation bubble-like-effect refers to the process of dislocation nucleation and annihilation, which likes the nucleation and annihilation process of the water bubbles. A significant plastic deformation dependence on the sample's aspect ratio and size was revealed. The atomic scale TEM observations also demonstrated that a single crystal to poly-crystal transition and a bcc to face-centred cubic phase transformation took place, which assisted the plastic deformation of Mo in small scale.

| S-EPMC4783708 | biostudies-literature

Perhydroazulene-based liquid-crystalline materials with smectic phases.

Project description:New liquid-crystalline materials with a perhydroazulene core were synthesized and the stereochemistry of these compounds was investigated. The mesomorphic properties of the new LC compounds were investigated by differential scanning colorimetry, polarizing optical microscopy and X-ray diffraction. We report here on the LC properties of nonchiral materials, which predominantly exhibit smectic phases and display nematic phases only within narrow temperature ranges. The dependence of the mesogenic behavior of the new materials on the stereochemistry of the core system was also investigated. All newly synthesized compounds were fully characterized by the usual spectroscopic and analytical methods.

| S-EPMC3326617 | biostudies-literature