Hasil untuk "Inorganic chemistry"

T. Baikie, Yanan Fang, Jeannette M. Kadro et al.

N. Connelly, W. Geiger

J. Lee

Evangelia Tarazi, Dimitra Statha, Christina Barda et al.

Second-degree burns are common dermal injuries requiring effective interventions to promote timely and complete skin regeneration. This study evaluated the wound-healing efficacy of topical hydrogels containing powdered licorice root (<i>Glycyrrhiza glabra</i> L.) extract at concentrations of 5%, 10%, and 20% <i>w</i>/<i>w</i> in a standardized murine model. Female SKH-hrHR2 hairless mice (<i>n</i> = 8 per group) were subjected to second-degree thermal burns, and treatment hydrogel formulations were applied once daily under occlusive dressings. Wound healing was assessed by planimetric area measurements, transepidermal water loss (TEWL), and histopathology. By Day 19, complete wound closure was achieved in 87.5% of animals in the 5% group, compared with 50.0% in the 10% group, 37.5% in the 20% group, and 25.0% in the sodium alginate control (Fisher’s exact test, <i>p</i> = 0.008). TEWL remained unchanged in the 5% group (baseline vs. Day 19: 8.4 ± 1.2 vs. 8.6 ± 1.3 g/m²/h; <i>p</i> > 0.05) but increased significantly in all other groups (e.g., sodium alginate: 8.2 ± 1.1 to 13.5 ± 2.0 g/m²/h; <i>p</i> = 0.0001). Histologically, the 5% formulation showed near-normal epidermal architecture and minimal inflammation (mean total score 2.0) compared with higher concentrations (6.0 for 10% and 7.3 for 20%) and sodium alginate (8.3). These findings demonstrate that a 5% <i>Glycyrrhiza glabra</i> hydrogel provides, among the concentrations studied here, the most favorable balance of wound closure, barrier restoration, and histological recovery, supporting its further development as a topical therapy for second-degree burns.

Xue Chen, Li-Li Yu, Shu-Ying Chen et al.

In this study, on the basis of a previous report, a pyrene-anchored nickel complex was designed and synthesized via five steps. The NMR spectra of the synthesized complex were found to exhibit significant proton and carbon chemical shift anisotropy. Cyclic voltammetry spectra showed that the introduction of pyrene slightly influenced the onset potential of CO₂ reduction. Lastly, controlled-potential electrolysis experiments disclosed that a pyrene-anchored nickel carbene–isoquinoline (<b>Ni</b>−<b>2</b>) complex selectively converted CO₂ into CH₄ with a TON value of 2.3 h⁻¹.

E. Fluck, Leopold Gmelin, R. Meyer et al.

Márcia G. A. da Cruz, Joy N. Onwumere, Jianhong Chen et al.

ABSTRACTPhotoluminescent carbon nanoparticles (CNPs), such as carbon dots (CDs), have attracted much attention owing to a unique set of properties, like high and tunable fluorescence. In this way, the use of carbon-rich lignin has been demonstrated to be a sustainable approach to producing a broad range of photoluminescent CNPs. However, the valorization of this complex polyphenol is limited when it comes to green and efficient ways of conversion. In addition, the existing solvothermal approaches using lignin often result in CDs with low photoluminescence, while flammable and/or toxic solvents are employed. Here, we depolymerized technical lignins, i.e. kraft and soda, through electroreductive cleavage in two different sustainable media: deep eutectic solvent and levulinic acid. After depolymerization, lignin-derived monomers were generated, with a predominance of aryl ether and phenolic groups, which were further combined with 1,2-Phenylenediamine to produce N-doped CNPs in a solvent-free approach. Photoluminescent CNPs with varied sizes were generated (5–50 nm), which presented a wide photoluminescence emission, from blue to red, depending on solvent polarity. These results demonstrate a feasible and sustainable route for the solvent-free synthesis of photoluminescent CNPs using lignin-derived monomers as carbon source, which may find applications in a wide range of fields.

Gabriel J. Mattos, Nikolai Yu. Tiuftiakov, Eric Bakker

This study successfully demonstrates the use of a lipophilic derivative of TEMPO, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl stearate, as a redox mediator for ion transfer processes at the interface between two immiscible electrolyte solutions. The results prove that TEMPO exhibits outstanding performance for mediating anion and cation transfer across polymeric ion-selective membranes doped with lipophilic ion-exchangers. The redox reaction at the inner interface of the electrode was controlled by cyclic voltammetry and allowed to modulate the flux of different ions according to the Hofmeister selectivity series. The behavior of this system was shown to agree well with the theory combining redox and phase-boundary potentials by comparing experimental and calculated cyclic voltammograms. Model ions were used to show the ideal Nernstian shift of the peak position while changing the phase-boundary potential at the outer interface when ion activity is varied in the aqueous phase. We also showcase that limitations from electrochemical instabilities in anion transfer observed using other redox probes are now overcome.

Mónica Fernández-Mafé, Andrea Armengol-Olivares, Lucía Miralles-Jordá et al.

Silver diamine fluoride (SDF) has demonstrated its clinical success for years in the arrest of caries lesions; however, the influence it could have on the success of restorations after its application still remains unknown. The purpose of this research was to study the relationship between the use of SDF and the adhesive strength of the materials used in restorations made with glass ionomers and composite resin, as well as with different adhesive systems. A sample consisting of 240 teeth divided into eight groups with 30 teeth in each of them (n = 30) was used. In these groups, the use of restoration with composite resin and glass ionomer was compared using different adhesive systems, with and without prior application of SDF. Notable differences in adherence were observed among the different groups depending on the filling material. There is also a significant effect of tooth type on adhesion. We can conclude that there is a relationship between the use of SDF and the adhesion between the tooth and the restorative materials analyzed.

Tahseen Kamal, Mazhar Ul-Islam, Sher Bahadar Khan et al.

The current study was aimed at developing BC-Cactus (BCC) composite hydrogels with impressive mechanical features for their potential applications in medical and environmental sectors. BCC composites hydrogels were developed through cactus gel coating on a never dried BC matrix. The FE-SEM micrographs confirmed the saturation of BC fibrils with cactus gel. Additionally, the presence of various functional groups and alteration in crystalline behavior was confirmed through FTIR and XRD analysis. Mechanical testing illustrated a three-times increase in the strain failure and an increase of 1.6 times in the tensile strength of BCC composite. Absorption capabilities of BCC were much higher than pure BC and it retained water for a longer period of time. Additionally, the rewetting and absorption potentials of composites were also higher than pure BC. The composite efficiently adsorbed Pb, Zn, Cu, and Co metals. Biocompatibility studies against human HaCat cell line indicated much better cell adhesion and proliferation of BCC compared to BC. These findings advocate that the BCC composite could find applications in medical, pharmaceutical and environmental fields.

Markus Laube, Jonas König, Martin Köckerling et al.

1-(4-Fluorobenzoyl)-9<i>H</i>-carbazole (<b>1</b>) was synthesized, starting from 9<i>H</i>-carbazole and 4-fluorobenzonitrile, by Friedel–Crafts acylation, using boron trichloride to direct the substitution in 1-position. Single-crystal X-ray diffraction analysis unambiguously revealed the molecular structure of <b>1</b>.