Browse
Submit Data
Databases
API
Help

Dataset Information

18 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The Role of the Surface Acid-Base Nature of Nanocrystalline Hydroxyapatite Catalysts in the 1,6-Hexanediol Conversion.

ABSTRACT: Hydroxyapatite is known to have excellent catalytic properties for ethanol conversion and lactic acid conversion, and their properties are influenced by the elemental composition, such as Ca/P ratio and sodium content. However, few reports have been examined for the surface acid-base nature of hydroxyapatites containing sodium ions. We prepared nanocrystalline hydroxyapatite (Ca-HAP) catalysts with various Ca/P ratios and sodium contents by the hydrothermal method. The adsorption and desorption experiments using NH₃ and CO₂ molecules and the catalytic reactions for 2-propenol conversion revealed that the surface acid-base natures changed continuously with the bulk Ca/P ratios. Furthermore, the new catalytic properties of hydroxyapatite were exhibited for 1,6-hexanediol conversion. The non-stoichiometric Ca-HAP(1.54) catalyst with sodium ions of 2.3 wt% and a Ca/P molar ratio of 1.54 gave a high 5-hexen-1-ol yield of 68%. In contrast, the Ca-HAP(1.72) catalyst, with a Ca/P molar ratio of 1.72, gave a high cyclopentanemethanol yield of 42%. Both yields were the highest ever reported in the relevant literature. It was shown that hydroxyapatite also has excellent catalytic properties for alkanediol conversion because the surface acid-base properties can be continuously controlled by the elemental compositions, such as bulk Ca/P ratios and sodium contents.

SUBMITTER: Nakagiri A

PROVIDER: S-EPMC8000547 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

RNA-seq Mouse 2-cell 1,6-Hexanediol

Project description:The majority of our genome is composed of repeated DNA sequences, which assemble into heterochromatin, a highly compacted structure that constrains their mutational potential. How heterochromatin forms during development and how its structure is maintained is not fully understood. Here, we show that mouse heterochromatin phase separates after fertilization, during the earliest stages of mammalian embryogenesis. Using high resolution, quantitative imaging and molecular biology approaches we show that pericentromeric heterochromatin displays liquid-like properties at the 2-cell stage, but it transitions into a more solid-like or gel-like state at the 4-cell stage, when chromocenters mature and heterochromatin becomes silent. Disrupting the condensates results in altered transcript levels of pericentromeric heterochromatin, suggesting a functional role for phase separation in heterochromatin function. Thus, our work shows that mouse heterochromatin forms membrane-less compartments with biophysical properties that change during development and provides new insights into the self-organization of chromatin domains during mammalian embryogenesis.

2023-08-23 | GSE211872 | GEO

Time-dependent effect of 1,6-hexanediol on biomolecular condensates and 3D chromatin organization.

Project description:BackgroundBiomolecular condensates have been implicated in multiple cellular processes. However, the global role played by condensates in 3D chromatin organization remains unclear. At present, 1,6-hexanediol (1,6-HD) is the only available tool to globally disrupt condensates, yet the conditions of 1,6-HD vary considerably between studies and may even trigger apoptosis.ResultsIn this study, we first analyzed the effects of different concentrations and treatment durations of 1,6-HD and found that short-term exposure to 1.5% 1,6-HD dissolved biomolecular condensates whereas long-term exposure caused aberrant aggregation without affecting cell viability. Based on this condition, we drew a time-resolved map of 3D chromatin organization and found that short-term treatment with 1.5% 1,6-HD resulted in reduced long-range interactions, strengthened compartmentalization, homogenized A-A interactions, B-to-A compartment switch and TAD reorganization, whereas longer exposure had the opposite effects. Furthermore, the long-range interactions between condensate-component-enriched regions were markedly weakened following 1,6-HD treatment.ConclusionsIn conclusion, our study finds a proper 1,6-HD condition and provides a resource for exploring the role of biomolecular condensates in 3D chromatin organization.

| S-EPMC8369800 | biostudies-literature

Comprehensive Understanding of the Kinetics and Mechanism of Fluoride Removal over a Potent Nanocrystalline Hydroxyapatite Surface.

Project description:Hydroxyapatite (HAp) was successfully synthesized from egg shells, a low cost and easily available biodegradable waste, by the precipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy, Fourier transform infrared, and Brunauer-Emmett-Teller (BET) surface area analysis. The surface area of HAp was found to be 144 m2/g with a crystalline size of 9-99 nm from the BET and XRD data. The maximum fluoride removal efficiency within 1 h using 0.3 g of the synthesized adsorbent at pH 6 was 95%. The adsorption of fluoride followed second-order kinetics, indicating that chemisorptions are the rate-limiting step. The experimental data were well fitted with Langmuir and Freundlich isotherms, validating both monolayer and multilayer sorption during the fluoride adsorption onto the porous HAp. The positive adsorption of F- ions at the HAp interface can be attributed to ion exchange/ion pairing and H-bonding below the pHpzc of HAp (pHpzc = 8), and the negative adsorption can be attributed to the electrostatic repulsion between O- and F- ions at alkaline pH. Both physical and chemical adsorption phenomena were also evidenced from the molecular parking area data. The results of a batch experiment show that the HAp synthesized from egg shells can be used as an effective, low-cost adsorbent for fluoride removal from a contaminated aqueous solution as well as groundwater compared to other adsorbents.

| S-EPMC6645433 | biostudies-literature

N-Heterocyclic carbenes as chiral Bronsted base catalysts: a highly diastereo- and enantioselective 1,6-addition reaction.

Project description:Highly diastereo- and enantioselective 1,6-addition of 1,3-ketoamides to p-quinone methides (p-QMs) using chiral NHCs as Brønsted base catalysts is developed. The reaction is based on the utilization of a 1,3-ketoamide having acidic N-H that forms a chiral ion-pair consisting of the enolate and the azolium ion. Different ?-ketoamides and functionalized p-QMs are applicable to the reaction. Synthetic application of the method is demonstrated via the preparation of highly enantioenriched ? and ?-lactam derivatives.

| S-EPMC6144034 | biostudies-literature

Concerted Functions of Surface Acid-Base Pairs and Supported Copper Catalysts for Dehydrogenative Synthesis of Esters from Primary Alcohols.

Project description:Dehydrogenative synthesis of esters from primary alcohols proceeded efficiently over a ZrO2-supported copper catalyst. A variety of esters were obtained from primary alcohols as well as diols in good to high yields. The key to the dehydrogenative synthesis of esters is the concerted effect of the acid-base pairs on ZrO2 and metallic copper.

| S-EPMC6644381 | biostudies-literature

Catalytic Conversion of Biomass-Derived 1,2-Propanediol to Propylene Oxide over Supported Solid-Base Catalysts.

Project description:A series of supported alkali metal salts were investigated as catalysts to produce propylene oxide (PO) from biomass-derived 1,2-propanediol via dehydrative epoxidation in a solid-gas reaction system. The effects of supports, cations, and anions in the alkali metal salts and calcination temperature were investigated by X-ray diffraction and CO2-temperature-programmed desorption. The results indicate the catalysts with relative mild basicity having higher yields of PO. The highest yield of PO is 58.2% from reactions at 400 °C at an atmospheric pressure over KNO3/SiO2. In addition, the catalyst could be reused after calcination in air at 550 °C.

| S-EPMC6644628 | biostudies-literature

Quantifying the phase separation property of chromatin-associated proteins under physiological conditions using an anti-1,6-hexanediol index.

Project description:BackgroundLiquid-liquid phase separation (LLPS) is an important organizing principle for biomolecular condensation and chromosome compartmentalization. However, while many proteins have been reported to undergo LLPS, quantitative and global analysis of chromatin LLPS property remains absent.ResultsHere, by combining chromatin-associated protein pull-down, quantitative proteomics and 1,6-hexanediol (1,6-HD) treatment, we develop Hi-MS and define an anti-1,6-HD index of chromatin-associated proteins (AICAP) to quantify 1,6-HD sensitivity of chromatin-associated proteins under physiological conditions. Compared with known physicochemical properties involved in phase separation, we find that proteins with lower AICAP are associated with higher content of disordered regions, higher hydrophobic residue preference, higher mobility and higher predicted LLPS potential. We also construct BL-Hi-C libraries following 1,6-HD treatment to study the sensitivity of chromatin conformation to 1,6-HD treatment. We find that the active chromatin and high-order structures, as well as the proteins enriched in corresponding regions, are more sensitive to 1,6-HD treatment.ConclusionsOur work provides a global quantitative measurement of LLPS properties of chromatin-associated proteins and higher-order chromatin structure. Hi-MS and AICAP data provide an experimental tool and quantitative resources valuable for future studies of biomolecular condensates.

| S-EPMC8369651 | biostudies-literature

Suppression of liquid-liquid phase separation by 1,6-hexanediol partially compromises the 3D genome organization in living cells.

Project description:Liquid-liquid phase separation (LLPS) contributes to the spatial and functional segregation of molecular processes within the cell nucleus. However, the role played by LLPS in chromatin folding in living cells remains unclear. Here, using stochastic optical reconstruction microscopy (STORM) and Hi-C techniques, we studied the effects of 1,6-hexanediol (1,6-HD)-mediated LLPS disruption/modulation on higher-order chromatin organization in living cells. We found that 1,6-HD treatment caused the enlargement of nucleosome clutches and their more uniform distribution in the nuclear space. At a megabase-scale, chromatin underwent moderate but irreversible perturbations that resulted in the partial mixing of A and B compartments. The removal of 1,6-HD from the culture medium did not allow chromatin to acquire initial configurations, and resulted in more compact repressed chromatin than in untreated cells. 1,6-HD treatment also weakened enhancer-promoter interactions and TAD insulation but did not considerably affect CTCF-dependent loops. Our results suggest that 1,6-HD-sensitive LLPS plays a limited role in chromatin spatial organization by constraining its folding patterns and facilitating compartmentalization at different levels.

| S-EPMC8501969 | biostudies-literature

Bifunctional organic polymeric catalysts with a tunable acid-base distance and framework flexibility.

Project description:Acid-base bifunctional organic polymeric catalysts were synthesized with tunable structures. we demonstrated two synthesis approaches for structural fine-tune. In the first case, the framework flexibility was tuned by changing the ratio of rigid blocks to flexible blocks within the polymer framework. In the second case, we precisely adjusted the acid-base distance by distributing basic monomers to be adjacent to acidic monomers, and by changing the chain length of acidic monomers. In a standard test reaction for the aldol condensation of 4-nitrobenzaldehyde with acetone, the catalysts showed good reusability upon recycling and maintained relatively high conversion percentage.

| S-EPMC5377424 | biostudies-literature

Discerning the Location and Nature of Coke Deposition from Surface to Bulk of Spent Zeolite Catalysts.

Project description:The formation of carbonaceous deposits (coke) in zeolite pores during catalysis leads to temporary deactivation of catalyst, necessitating regeneration steps, affecting throughput, and resulting in partial permanent loss of catalytic efficiency. Yet, even to date, the coke molecule distribution is quite challenging to study with high spatial resolution from surface to bulk of the catalyst particles at a single particle level. To address this challenge we investigated the coke molecules in HZSM-5 catalyst after ethanol conversion treatment by a combination of C K-edge X-ray absorption spectroscopy (XAS), 13C Cross polarization-magic angle spinning nuclear magnetic resonance (CP-MAS NMR) spectroscopy, and atom probe tomography (APT). XAS and NMR highlighted the aromatic character of coke molecules. APT permitted the imaging of the spatial distribution of hydrocarbon molecules located within the pores of spent HZSM-5 catalyst from surface to bulk at a single particle level. 27Al NMR results and APT results indicated association of coke molecules with Al enriched regions within the spent HZSM-5 catalyst particles. The experimental results were additionally validated by a level-set-based APT field evaporation model. These results provide a new approach to investigate catalytic deactivation due to hydrocarbon coking or poisoning of zeolites at an unprecedented spatial resolution.

| S-EPMC5120296 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data