The metal–organic framework (MOF) HKUST‐1 was employed as an interaction matrix for fundamental loading studies of anthraquinone dyes. Chosen dyes were alizarin (A), alizarin S (AS), disperse blue 1 ...(B1), disperse blue 3 (B3), disperse blue 56 (B56) and purpurin (P). All materials were characterized by XRD, FTIR, TGA and SEM. Hence the interaction of dyes with the framework was characterized by theoretical–experimental differential analysis. One‐pot loading strategy resulted in more efficient scavenging of dyes, and reached 100 % for B56 using 50 mg L−1. SEM revealed important microstructural changes, the smaller crystals ranged 0.8–3 μm in size and almost all composite sizes were from this to higher values, reaching 70 μm, with varying shapes. Two composites were larger in size range (about 2500–1000 μm), and were shaped as rods, octahedrons and coffin lids. Indeed, the microstructure could be modulated depending on preparation conditions and type of loaded dye. For the higher loading series, N2 adsorption and XPS experiments were carried on to further evidence dye–MOF interactions. Ab initio prediction of structural properties for A@HKUST‐1 and P@HKUST‐1 were obtained by means of solid‐state CRYSTAL14 code at the PBE0 level of theory. Computed findings evidenced two O→Cu coordinative bonds, one from O‐ketone and the other from O‐phenolate moiety as main interactions towards CuNET centers.
The dye is cast: The metal–organic framework (MOF) HKUST‐1 was employed as an interaction matrix for fundamental loading studies of anthraquinone dyes (e.g., alizarin in the picture). The interaction of dyes with the framework was characterized by theoretical–experimental differential analysis. A microstructural changes were encountered.
The H2O@HKUST‐1 and DMF@HKUST‐1 systems were experimental and computationally assessed, employing XRD/TGA/FT‐IR/DFT‐calculations, evidencing that H2O or DMF coordinated to Cu, modulating HKUST‐1 ...photocatalytic properties. DMF@HKUST‐1 has narrower bandgap promoting higher‐crystallinity and light‐harvesting. H2O@HKUST‐1 showed smaller particle sizing and sharp morphology. Theoretical models, (H2O)1@HKUST‐1 and (DMF)1@HKUST‐1, containing one coordinated molecule, elucidated bandgap modulation associated with infiltration. H2O@HKUST‐1/DMF@HKUST‐1 presented bandgaps eV of 3.6/3.4, by Tauc plots, and 3.55/3.26, by theoretical calculations, narrowing bandgap, compared with non‐solvated HKUST‐1(HKUST‐1NS). Both composites raised the valence band (VB) and lowered the conduction band (CB), but DMF@HKUST‐1 most raised VB. Topological analysis revealed that guests i) with higher electronic density, raised VB, and ii) induced π‐backbonding, lowering CB. DMF@HKUST‐1 presented a higher photocatalytic hydrogen evolution (μmol), 26.45, in the first 30 min of the reaction, nevertheless, H2O@HKUST‐1 presented a competitive activity, of 17.32. In large periods, H2O@HKUST‐1/DMF@HKUST‐1 showed practically the same hydrogen evolution, 45.50/49.03.
H2O@HKUST‐1 and DMF@HKUST‐1 composites are characterized by XRD/TGA/FT‐IR/DFT‐calculations, evidencing that H2O/DMF coordinating to Cu, present bandgaps eV of 3.6/3.4, and 3.55/3.26 (theoretical/experimental), raising valence‐band and lowering conduction‐band, DMF@HKUST‐1 most raise valence‐band, comparative with HKUST‐1. Composites develop photocatalytic hydrogen evolution (μmol) of 26.45 (DMF@HKUST‐1), and 17.32 (H2O@HKUST‐1) in short periods, in large periods result in 45.50/49.03, due to CuBTC ⋅ H2O phase formation.
Hirshfeld-I charges were implemented in the
Crystal
code, for periodic calculations with localized atomic basis sets. Some particular features of the present periodic implementation are detailed and ...discussed by means of selected illustrating examples. In these examples, the Hirshfeld-I charges are somewhere between the Bader and the Mulliken values and closer to the former. The implementation exploits heavily symmetry aspects and is shown to scale linearly with the unit cell dimension.
A series of novel 1-N-α-d-glucopyranosyl-1H-1,2,3-triazole xanthines was synthesized from azido sugars (glucose, galactose, and lactose) and propargyl xanthines (theophylline and theobromine) using a ...typical copper (I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition. The corrosion inhibition activities of these new carbohydrate-xanthine compounds were evaluated by studying the corrosion of API 5 L X70 steel in a 1 M HCl medium. The results showed that, at 10 ppm, a 90% inhibition efficiency was reached by electrochemical impedance spectroscopy. The inhibitory efficiency of these molecules is explained by means of quantum chemical calculations of the protonated species with the solvent effect, which seems to better represent the actual situation of the experimental conditions. Some quantum chemical parameters were analyzed to characterize the inhibition performance of the tested molecules.
In low-middle income countries (LMIC), wastewater treatment using native microalgal-bacterial consortia has emerged as a cost-effective and technologically-accessible remediation strategy. This study ...evaluated the effectiveness of six microalgal-bacterial consortia (MBC) from the Ecuadorian Amazon in removing organic matter and nutrients from non-sterilized domestic wastewater (NSWW) and sterilized domestic wastewater (SWW) samples. Microalgal-bacterial consortia growth, in NSWW was, on average, six times higher than in SWW. Removal rates (RR) for NH
- N and PO
-P were also higher in NSWW, averaging 8.04 ± 1.07 and 6.27 ± 0.66 mg L
d
, respectively. However, the RR for NO
-N did not significantly differ between SWW and NSWW, and the RR for soluble COD slightly decreased under non-sterilized conditions (NSWW). Our results also show that NSWW and SWW samples were statistically different with respect to their nutrient concentration (NH
-N and PO
-P), organic matter content (total and soluble COD and BOD
), and physical-chemical parameters (pH, T, and EC). The enhanced growth performance of MBC in NSWW can be plausibly attributed to differences in nutrient and organic matter composition between NSWW and SWW. Additionally, a potential synergy between the autochthonous consortia present in NSWW and the native microalgal-bacterial consortia may contribute to this efficiency, contrasting with SWW where no active autochthonous consortia were observed. Finally, we also show that MBC from different localities exhibit clear differences in their ability to remove organic matter and nutrients from NSWW and SWW. Future research should focus on elucidating the taxonomic and functional profiles of microbial communities within the consortia, paving the way for a more comprehensive understanding of their potential applications in sustainable wastewater management.
Summary
The concept that anatomical variations in the coronary artery tree might be influenced by genes is relatively old. However, empirical evidence on the effect of genotype on the coronary ...morphology is still scarce. In the Syrian hamster, there is a septal coronary artery which arises from the left or from the right coronary artery and supplies most of the interventricular septum. The aim was to decide whether the anatomical origin of the septal artery is subject to inheritance factors. Overall, 483 internal casts of the heart and coronary arteries were examined. All the hamsters included in this study had normal coronary arteries. The results of 74 crosses were compared statistically to seek for any significant difference between the phenotypes of the offspring and the phenotypes of the parents. The left septal artery was over‐represented in the offspring of crosses between parents having both a left septal artery (p < .01), while the right septal artery was over‐represented in the offspring of crosses between parents, one with a right and the other with a left septal artery (p < .001), and, more markedly, in the offspring of crosses between parents both with a right septal artery (p < .001). These results are the first to reveal that the coronary artery pattern is influenced by genetic factors, at least in its proximal portion with regard to the aorta.
•Trace metal toxicity in beaches of Miri, Malaysia (Borneo Island).•Presence of metals above permissible limit.•Anthropogenic input of metals in industrial and natural beaches.
Forty-three sediment ...samples were collected from the beaches of Miri City, Sarawak, Malaysia to identify the enrichment of partially leached trace metals (PLTMs) from six different tourist beaches. The samples were analyzed for PLTMs Fe, Mn, Cr, Co, Cu, Ni, Pb, Sr and Zn. The concentration pattern suggest that the southern side of the study area is enriched with Fe (1821–6097μgg−1), Mn (11.57–90.22μgg−1), Cr (51.50–311μgg−1), Ni (18–51μgg−1), Pb (8.81–84.05μgg−1), Sr (25.95–140.49μgg−1) and Zn (12.46–35.04μgg−1). Compared to the eco-toxicological values, Cr>Effects range low (ERL), Lowest effect level (LEL), Severe effect level (SEL); Cu>Unpolluted sediments, ERL, LEL; Pb>Unpolluted sediments and Ni>ERL and LEL. Comparative results with other regions indicate that Co, Cr, Cu, Ni and Zn are higher, indicating an external input rather than natural process.
Fibromyalgia is a prevalent disease of unknown aetiology and is difficult to diagnose. Despite the availability of the American College of Rheumatology criteria for diagnosis, it continues to be a ...challenge in the field of primary health care in terms of identifying individuals with susceptibility to developing the disease. The aim of this study is to design and validate a predictive model of fibromyalgia in subjects with a history of chronic pain.
This multicentre observational retrospective cohort study was performed on patients aged >18 years, who visited four primary health centres between 2017 and 2020, with a diagnosis of fibromyalgia or arthritis. The Bootstrapping resampling method was used for the validation of the model.
A total of 198 subjects with fibromyalgia (93 with osteoarthritis, 20 with other types of arthritis, 4 with rheumatoid arthritis) and 120 without fibromyalgia (116 with osteoarthritis, 23 with other types of arthritis, 7 with rheumatoid arthritis) participated in the study. The predictive factors of the final model were self-reported age at onset of symptoms, first-line family history of neurological diseases, exposure to levels of stress, history of post-traumatic acute emotional stress, and personal history of chronic widespread pain prior to diagnosis, comorbidity, and pharmacological prescription during the year of diagnostic confirmation. The predictive capacity adjusted by Bootstrapping was 0.972 (95% CI: 0.955-0.986).
The proposed model showed an excellent predictive capacity. The risk calculator designed from the predictive model allows health professionals to have a useful tool to identify subjects at risk of developing fibromyalgia.
Hydrolysis of TiCl4: Initial Steps in the Production of TiO2 Wang, Tsang-Hsiu; Navarrete-López, Alejandra M; Li, Shenggang ...
The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory,
07/2010, Letnik:
114, Številka:
28
Journal Article
Recenzirano
The hydrolysis of titanium tetrachloride (TiCl4) to produce titanium dioxide (TiO2) nanoparticles has been studied to provide insight into the mechanism for forming these nanoparticles. We provide ...calculations of the potential energy surfaces, the thermochemistry of the intermediates, and the reaction paths for the initial steps in the hydrolysis of TiCl4. We assess the role of the titanium oxychlorides (Ti x O y Cl z ; x = 2−4, y = 1, 3−6, and z = 2, 4, 6) and their viable reaction paths. Using transition-state theory and RRKM theory, we predicted rate constants including the effect of tunneling. Heats of formation at 0 and 298 K are predicted for TiCl4, TiCl3OH, TiOCl2, TiOClOH, TiCl2(OH)2, TiCl(OH)3, Ti(OH)4, and TiO2 using the CCSD(T) method with correlation consistent basis sets extrapolated to the complete basis set limit and compared with the available experimental data. Clustering energies and heats of formation are calculated for neutral clusters. The calculated heats of formation were used to study condensation reactions that eliminate HCl or H2O. The reaction energy is substantially endothermic if more than two HCl molecules are eliminated. The results show that the mechanisms leading to formation of TiO2 nanoparticles and larger ones are complicated and will have a strong dependence on the experimental conditions.
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