Willardhuffman8864

We use a variety of computational methods to characterize and compare the hydrogen atom transfer (HAT) and epoxidation reaction pathways for oxidation of cyclohexene by an iron(iv)-oxo complex. Previous B3LYP calculations have led to predictions that both alcohol (from the HAT route) and epoxide should be formed in similar amounts, which was not in agreement with experiment where only the HAT product was observed. We show here that ab initio calculations which can take both static and dynamic correlation into account are needed to explain the experimentally observed dominance of the HAT process. Since these systems do not have very strong multireference character we have also tested different flavours of local coupled cluster methods. We suggest that further improvements are necessary before they can provide highly accurate results for these systems.In organic synthesis, transition-metal and photoredox-catalysis-based reaction systems are emerging trends for the construction of C-S bonds. Many review articles have recently appeared in this field; however, we present herein an overview of metal-free C-S coupling reactions using thiols or disulfides as sulfur surrogates. The oxidants we have considered include peroxides, tert-butyl nitrite (TBN), DDQ, iodine reagents, and molecular oxygen. In addition, selective electrochemical oxidative transformations are also covered with mechanistic details.An efficient and concise catalyst-free one-pot synthetic protocol for obtaining dihydroisoquinoline derivatives has been developed via the three-component condensation of isoquinolines with β-keto acids and sulfonyl chlorides. This transformation involving decarboxylative dearomatization worked well under mild and water-mediated conditions. The protocol tolerates diverse functional groups, furnishing the dihydroisoquinoline products in good to excellent yields.Communication is one of the most remarkable behaviors in the living world. It is an important prerequisite for building an artificial cell which can be considered as alive. Achieving complex communicative behaviors leveraging synthetic particles will likely fill the gap between artificial vesicles and natural counterpart of cells and allow for the discovery of new therapies in medicine. In this review, we highlight recent endeavors for constructing communication with synthetic particles by revealing the principles underlying the communicative behaviors. Emergent progress using active particles to achieve communication is also discussed, which resembles the dynamic and out-of-equilibrium properties of communication in nature.An original approach never tackled so far allowed correlating the basicity and hydrophilic character of clay catalysts to surface interaction with 17α-Ethinylestradiol (EE2) during ozonation in water. The clay catalysts were found to behave specifically according to their silica/alumina ratio like soils in natural oxidative processes. Acid-activated bentonites (HMt) and ion-exchanged montmorillonite (NaMt and Fe(ii)Mt) showed catalytic activity in the ozonation of 17α-ethinylestradiol (EE2) in aqueous media. In the absence of catalysts, the degradation of (EE2) reached 72% after one minute of ozonation and 99.5% after 60 minutes. In the presence of Fe(ii)Mt, EE2 degradation (96%) was achieved after only one minute of ozonation. Under similar conditions, almost total degradation to 99.99% was registered in 15 minutes of ozonation but without total mineralization of the intermediates. Moderately acid-activated bentonites exhibited higher activity affording total mineralization within a short period of ozonation. The catalytic activity of clay catalysts was found to correlate with their surface basicity and hydrophilic character. The results obtained herein allow understanding soil behavior in natural oxidative degradation of organic molecules and envisaging effective soil-based catalysts with surface properties judiciously tailored according to the nature of organic pollutants in solvent free media.Noble metal nanoparticles dispersed in semiconductors, mainly in ZnO, have been intensively investigated. Au dispersion and possible precipitation as well as damage growth were studied in ZnO of various orientations, a-plane (112[combining macron]0) and c-plane (0001), using 1 MeV Au+-ion implantation with an ion fluence of 1.5 × 1016 cm-2 and subsequently annealed at 600 °C in an ambient atmosphere for one hour. Afterwards, irradiation with 10 MeV O3+ at a fluence of 5 × 1014 cm-2 was used to modify Au distribution and internal morphology as well as to follow the structural modification of ZnO under high-energy light-ion irradiation. Rutherford backscattering spectrometry in the channelling mode (RBS-C) and Raman spectroscopy show that O irradiation with high electronic energy transfer distinctly modifies the implanted Au layer in various ZnO facets; it introduces additional displacement and disorder in the O sublattice mainly in the a-plane while not creating an additional strain in this facet. This has been confirmed by XRD analysis, identifying the appearance of an additional phase (nanocrystallites) after Au implantation, which diminishes after O irradiation, and RBS-C has identified decreased disorder in the Zn-sublattice. Unlike in c-plane ZnO, it has been possible to observe a local compressive deformation around spherical defects, which is more pronounced after O irradiation simultaneously with the vertical strain introduced in the Au-implanted and annealed layer. Transmission electron microscopy (TEM) with energy dispersive spectroscopy (EDS) was employed to investigate the interior morphology, showing the occurrence of Au-hcp clusters of the small sizes of about 4-10 nm; neither the cluster sizes nor their shapes are significantly affected by the O irradiation.Retraction of 'A facile cation exchange-based aqueous synthesis of highly stable and biocompatible Ag2S quantum dots emitting in the second near-infrared biological window' by Rijun Gui et al., Dalton Trans., 2014, 43, 16690-16697, DOI 10.1039/C4DT00699B.In situ spatial temporal measurement of monomer conversion during adhesive bondline curing remains a challenging area. The aim of this work was to demonstrate the effectiveness of using confocal Raman microscopy in a specially configured experimental set-up, as a versatile tool for measuring monomer concentration changes as a function of both time and adhesive bond depth during ethyl cyanoacrylate polymerisation. This also allowed monitoring of the extent of polymerisation at the adhesive substrate interface independently of the bulk bondline polymerisation region. Key kinetic parameters such as inhibition time tlag, rate of reaction Rmax and extent of reaction [αt]max were obtained by fitting the experimental data to sigmoidal growth curves using simple piecewise regression models. A systematic characterisation of a polymerisation reaction was conducted using different sample substrate types (copper alloy (red brass), aluminium, aluminium alloy, stainless steel and borosilicate glass) and at various reactionsitu using confocal Raman microscopy which is a powerful technique for investigating such surface-confined and bulk polymerisation reactions.The development of high-entropy alloys (HEAs) focuses on exploring compositional regions in multi-component systems with all alloy elements in equal or near-equal atomic concentrations. Initially it was based on the main idea that high mixing configurational entropy contributions to the alloy free energy could promote the formation of a single solid solution phase. By using the ab-initio based Cluster Expansion (CE) Hamiltonian model constructed for the quinary bcc Cr-Ta-Ti-V-W system in combination with Monte Carlo (MC) simulations, we show that the phase stability and chemical short-range order (SRO) of the equiatomic quinary and five sub-quaternary systems, as well as their derivative alloys, can dramatically change the order-disorder transition temperatures (ODTT) as a function of alloy compositions. In particular, it has been found, that the equiatomic quaternary Ta-Ti-V-W and Cr-Ta-Ti-W alloys had the lowest order-disorder transition temperature (500 K) among all the analysed equiatomic compositions. In all investigated alloy systems, the strongest chemical ordering has been observed between Cr and V, which led to the conclusion that decreasing the concentration of either Cr or V might be beneficial in terms of decreasing the ODTT. It also predicts that increasing concentration of Ti significantly decreases the ODTT. Our analysis of chemical SRO as a function of alloy composition allows to understand the microstructure evolution of HEAs as a function of temperature in excellent agreement with available experimental observations. Importantly, our free energy of mixing and SRO calculations predict that the origin of precipitates formed by Cr- and V-rich in the sub-quaternary Cr-Ta-V-W system is driven by the thermodynamics. The modelling results are in an excellent agreement with experimental observation of Cr and V segregation in the W0.38Ta0.36Cr0.15V0.11 alloy which in turns shows an exceptional radiation resistance.Dramatically increased CO2 concentration from several point sources is perceived to cause severe greenhouse effect towards the serious ongoing global warming with associated climate destabilization, inducing undesirable natural calamities, melting of glaciers, and extreme weather patterns. CO2 capture and utilization (CCU) has received tremendous attention due to its significant role in intensifying global warming. SN 52 cell line Considering the lack of a timely review on the state-of-the-art progress of promising CCU techniques, developing an appropriate and prompt summary of such advanced techniques with a comprehensive understanding is necessary. Thus, it is imperative to provide a timely review, given the fast growth of sophisticated CO2 capture and utilization materials and their implementation. In this work, we critically summarized and comprehensively reviewed the characteristics and performance of both liquid and solid CO2 adsorbents with possible schemes for the improvement of their CO2 capture ability and advances in CO2 utilization. Their industrial applications in pre- and post-combustion CO2 capture as well as utilization were systematically discussed and compared. With our great effort, this review would be of significant importance for academic researchers for obtaining an overall understanding of the current developments and future trends of CCU. This work is bound to benefit researchers in fields relating to CCU and facilitate the progress of significant breakthroughs in both fundamental research and commercial applications to deliver perspective views for future scientific and industrial advances in CCU.Idiopathic pulmonary fibrosis (IPF) is a debilitating chronic progressive and fibrosing lung disease that culminates in the destruction of alveolar integrity and dismal prognosis. Its etiology is unknown and pathophysiology remains unclear. While great advances have been made in elucidating the pathogenesis mechanism, considerable gaps related to information on pathogenetic pathways and key protein targets involved in the clinical course of the disease exist. These issues need to be addressed for better clinical management of this highly challenging disease. Omics approach has revolutionized the entire area of disease understanding and holds promise in its translation to clinical biomarker discovery. This review outlines the contribution of proteomics towards identification of important biomarkers in IPF in terms of their clinical utility, i.e. prognosis, differential diagnosis, disease progression and treatment monitoring. The major dysregulated pathways associated with IPF are also discussed. Based on numerous proteomics studies on human and animal models, it is proposed that IPF pathogenesis involves complex interactions of several pathways such as oxidative stress, endoplasmic reticulum stress, unfolded protein response, coagulation system, inflammation, abnormal wounding, fibroblast proliferation, fibrogenesis and deposition of extracellular matrix.