Zobrazení zdroje stránky Galbraithlambertsen5956

Altogether, we conclude that, in bulk, Cp is shown to exhibit a broad peak around 225 K for the SPC and TIP4P models, and around 250 K for the TIP4P/2005 model, in qualitative agreement with the experimentally observed features in Cp measurements. For interfacial water, in all cases, the broad Cp peak disappears. This result, at odds with experimental observations, suggests that disorder and hydrogen bonding at the interface (not yet taken into account) have a fundamental role in confined water transitions.Cs2Au2I6, a lead-free photovoltaic material, has been synthesized via controlled and systematic addition of hydroiodic acid (HI) to CsAuCl4. X-ray diffraction studies suggest the formation of Cs2Au2I6 when a threshold concentration of HI is added to CsAuCl4. The final compound shows good stability against light, oxygen and moisture and at temperatures up to 140 °C without any phase degradation. The stability of Cs2Au2I6 is also confirmed by its high negative formation energy and the convex hull diagram constructed using Density Functional Theory (DFT). Absorption studies suggest an abrupt band shift from 2.31 eV to 1.06 eV when HI concentration reaches the threshold limit (∼100 μl). A sharp absorption edge was found for Cs2Au2I6 with an Urbach energy of 59 meV, indicating lower structural disorder and higher crystallinity.The efficacy of ongoing anticancer treatment is often compromised by some barriers, such as low drug content, nonspecific release of drug delivery system, and multidrug resistance (MDR) effect of tumors. Herein, in the research a novel functionalized PEG-based polymer cystine-(polyethylene glycol)2-b-(poly(2-methacryloyloxyethyl ferrocenecarboxylate)2) (Cys-(PEG45)2-b-(PMAOEFC)2) with multi-stimuli sensitive mechanism was constructed, in which doxorubicin (DOX) was chemical bonded through Schiff base structure to provide acid labile DOX prodrug (DOX)2-Cys-(PEG45)2-b-(PMAOEFC)2. Afterwards, paclitaxel (PTX) and its diselenide bond linked PTX dimer were encapsulated into the prodrug through physical loading, to achieve pH and triple redox responsive (DOX)2-Cys-(PEG45)2-b-(PMAOEFC)2@PTX and (DOX)2-Cys-(PEG45)2-b-(PMAOEFC)2@PTX dimer with ultrahigh drugs content. The obtained nanovehicles could self-assemble into globular micelles with good stability based on fluorescence spectra and TEM observation. Moreover, there was a remarkable "reassembly-disassembly" behavior caused by phase transition of micelles under the mimic cancerous physiological environment. DOX and PTX could be on-demand released in acid and redox stress mode, respectively. Meanwhile, in vivo anticancer studies revealed the significant tumor inhibition of nanoformulas. This work offered facile strategies to fabricate drug nanaovehicles with tunable drug content and types, it has a profound significance in overcoming MDR effect, which provided more options for sustainable cancer treatment according to the desired drug dosage and the stage of tumor growth.We firstly describe a silver-catalyzed direct C-H functionalization of cyclic aldimines with cyclopropanols and cyclobutanols via a radical-mediated C-C bond cleavage strategy. The desired products were generated in decent yields with wide substrate scope under mild reaction conditions. In addition, a gram-scale reaction and synthetic transformation of the product were performed.Herein, we reported a RuCo alloy with nitrogen-doped porous carbon (RuCo/NPC) as efficient trifunctional electrocatalysts for Zn-air batteries and water splitting. The versatility and catalytic activity of this catalyst is achieved by adjusting the Ru/Co ratio. The as-assembled Zn-air battery and overall water splitting with RuCo/NPC present outstanding catalytic performances.The detection of telomerase is of great significance for monitoring cell canceration. The conventional methods depend on the extension of telomerase towards its primer to conduct signal transduction. [https://www.selleckchem.com/products/GSK690693.html GSK690693 inhibitor] Herein, a specific and reliable detection strategy based on stepwise recognition was developed for tandem detection of metal ions and enzymes. We first synthesized an electrically active metal-organic framework (MIL-101(Fe)), which can act directly as a signal reporter in phosphate buffered saline after being modified with capture DNA (cDNA). When the zinc ion is added as a coenzyme factor, the modified hairpin DNA on the electrode is cleaved by DNAzyme to yield the activated primer. After the addition of telomerase, the cleaved DNA strand would be extended, and the resulting sequence will be hybridized with the signal label of MIL-101(Fe)-cDNA. Therefore, a signal-on strategy for the detection of telomerase was achieved based on the direct electrochemical analysis of MIL-101(Fe). Moreover, this electrochemical biosensor can discriminate telomerase activity among different cell lines. The stepwise recognition ensured the advantages of an electrochemical biosensor such as high sensitivity and specificity during the detection process, providing a novel method for monitoring and diagnosis of diseases.For prevention of the coronavirus disease 2019 caused by the novel coronavirus SARS-CoV-2, an effective vaccine is critical. Herein, several potential peptide epitopes from the spike protein of SARS-CoV-2 have been synthesized and covalently linked with the cross-reactive material (CRM197). Immunization of mice with the resulting conjugates induced high titers of IgG antibodies against the spike protein. Importantly, the post-immune sera effectively neutralized SARS-CoV-2 pseudovirus, suggesting the epitopes identified are protective, and these conjugates are promising leads for anti-SARS-CoV-2 vaccine development.The synthesis of the pyridazine-bridged expanded rosarin 1 and a reduced precursor, semi-rosarinogen 2, is reported. A single crystal X-ray diffraction analysis of 1 and theoretical calculations show that both 1 and 2 have distorted structures. Expanded rosarin 1 and its precursor 2 can differentiate various thiols in organic solvents by means of species-specific colour changes and reaction times.Magnetically guided self-assembly of nanoparticles is a promising bottom-up method to fabricate novel materials and superstructures, such as, for example, magnetic nanoparticle clusters for biomedical applications. The existence of assembled structures has been verified by numerous experiments, yet a comprehensive theoretical framework to explore design possibilities and predict emerging properties is missing. Here we present a model of magnetic nanoparticle interactions built upon a Langevin dynamics algorithm to simulate the time evolution and aggregation of colloidal suspensions. We recognise three main aggregation regimes non-aggregated, linear and clustered. Through systematic simulations we have revealed the link between single particle parameters and which aggregates are formed, both in terms of the three regimes and the chance of finding specific aggregates, which we characterise by nanoparticle arrangement and net magnetic moment. Our findings are shown to agree with past experiments and may serve as a stepping stone to guide the design and interpretation of future studies.Genipin is a naturally occurring nontoxic cross-linker, which has been widely used for drug delivery due to its excellent biocompatibility, admirable biodegradability and stable cross-linked attributes. These advantages led to its extensive application in the fabrication of hydrogels for drug delivery. This review describes the physicochemical characteristics and pharmacological activities of genipin and attempts to elucidate the detailed mechanisms of the cross-linking reaction between genipin and biomaterials. The current article entails a general review of the different biomaterials cross-linked by genipin chitosan and its derivatives, collagen, gelatin, etc. The genipin-cross-linked hydrogels for various pharmaceutical applications, including ocular drug delivery, buccal drug delivery, oral drug delivery, anti-inflammatory drug delivery, and antibiotic and antifungal drug delivery, are reported. Finally, the future research directions and challenges of genipin-cross-linked hydrogels for pharmaceutical applications are also discussed in this review.Magnetic biochar was successfully synthesized via a one-step method through simultaneous activation and magnetization with alkali-acid modified citrus peel as the raw material, which could effectively penetrate interfering substances. The characterization analysis showed that the magnetic biochar exhibited high graphitic degree, higher specific surface area and smaller pore diameter, which resulted in superior adsorption performance. The magnetic biochar was used as an adsorbent for the cleanup and extraction of 22 pesticides (consisting of insecticides, fungicides and herbicides) from vegetables and the quantitative detection was completed by gas chromatography-mass spectrometry (GC-MS). The Plackett-Burman experimental design (PBD), central composite design (CCD) and response surface methodology (RSM) were employed to identify significant factors and optimal experimental conditions. Under optimal conditions, the methodological linearity was in the range of 1-100 μg kg-1 with the coefficients of determination ranging from 0.9969-0.9999, while the limits of detection (LODs) and limits of quantification (LOQs) were 0.31-0.91 μg kg-1 and 1.03-3.05 μg kg-1, respectively. The recoveries of the analytes from spiked samples were in the range of 78.1-112.5%. It was confirmed that the method established by using magnetic graphitic biochar as the adsorbent is an efficient pretreatment procedure and could be successfully applied for analysis of food safety.Rare earth equiatomic quaternary Heusler (EQH) compounds with chemical formula RXVZ (R = Yb, Lu; X = Fe, Co, Ni; Z = Al, Si) have recently attracted much attention since these materials are easily prepared and they also provide interesting properties for future spintronic applications. In this work, rare Earth-based EQH compounds in three types of structures are theoretically investigated through first-principles calculations based on density functional theory. We find that most of the studied rare Earth EQH compounds exhibit magnetic ground states including ferro-, antiferro-, and ferri-magnetic phases. Owing to the nearly closed shell f orbital in Lu and Yb, the spin magnetic moments mainly come from the 3d transition metal elements. In particular, in the type I structure, a large portion (7 out of 12) of EQH compounds are ferromagnetic half-metals (HMs) with integer magnetic moments ranging from 1 to 3 μB. In the type II structure, YbFeVAl is found to be a rare case of antiferro-magnetic (AFM) half-metal with zero total magnetic moments. Surprisingly, we also discover an unusual magnetic semiconductor LuCoVSi in the type III structure with a total spin magnetic moment of 3.0 μB and an indirect band gap of 0.2 eV. The structural and magnetic stabilities such as formation energy, magnetization energy as well as the mechanical stabilities such as the bulk, shear, and Young's moduli, and Poisson's, and Pugh's ratios of these EQH compounds are also investigated. Most of the studied compounds exhibit mechanical stability under the mechanical stability criteria and show elastic anisotropy. Our work provides guidelines for experimental researchers to synthesize useful materials in future spintronic applications.