Notes

Protective connection between rosmarinic acidity in opposition to azoxymethane-induced digestive tract most cancers throughout subjects.
We report a new scheme for chiral recognition using coordination polymers of Ag+ with a chiral thiol ligand that contains a binding group. N-Benzoyl-l-cysteine ethyl ester equipped with a boronic acid group at the para position of the phenyl ring forms coordination polymers with Ag+ in alkaline aqueous solutions that exhibit excellent selectivity toward a d-glucose enantiomer over l-glucose, while the coordination polymers from the d-cysteine-based thiol ligand are specific for l-glucose. It is assumed that a conformation change occurs upon interaction of a saccharide molecule with the polymeric chain receptor, for which the next binding is promoted, leading to the highly effective chiral recognition, despite the flexible nature of the polymeric receptor.Over the past two decades, antibody drug conjugates (ADCs) and small molecule drug conjugates (SMDCs) have widely employed valine-citruline and related cathepsin-cleavable linkers due to their stability in plasma and their rapid cleavage by lysosomal cathepsins. However, a number of recent studies have illustrated that these linkers are subject to cleavage by exogenous enzymes such as Ces1C and neutrophil elastase, thus resulting in off-target release of drug. As such, there is a need to diversify the portfolio of ADC linkers in order to overcome nonspecific drug release. Rather than targeting cathepsins, we began with an "enzyme agnostic" screen in which a panel of 75 peptide FRET pairs were screened for cleavage in lysosomal extracts and in plasma. Unexpectedly, a series of Asn-containing peptides emerged from this screen as being cleaved far more quickly than traditional ValCit-type linkers while retaining excellent stability in plasma. Catabolism studies demonstrated that these linkers were cleaved by legumain, an asparaginyl endopeptidase that is overexpressed in a variety of cancers and is known to be present in the lysosome. MMAE-containing ADCs that incorporated these new linkers were shown to exhibit highly potent and selective cytotoxicity, comparable to analogous ValCit ADCs. Importantly, the Asn-containing linkers were shown to be completely stable to human neutrophil elastase, an enzyme thought to be responsible for the neutropenia and thrombocytopenia associated with ValCitPABC-MMAE ADCs. The legumain-cleavable ADCs were shown to have excellent stability in both mouse and human serum, retaining >85% of the drug after 1 week of incubation. Moreover, the corresponding small molecule FRET pairs exhibited less then 10% cleavage after 18 h in mouse and human serum. On the basis of these results, we believe that these new linkers (AsnAsn in particular) have significant potential in both ADC and SMDC drug delivery applications.ConspectusMetal nanoparticles have been utilized for a vast amount of plasmon enhanced spectroscopies and energy conversion devices. Their unique optical properties allow them to be used across the UV-vis-NIR spectrum tuned by their size, shape, and material. In addition to utility in enhanced spectroscopy and energy/charge transfer, the plasmon resonance of metal nanoparticles is sensitive to its surrounding environment in several ways. EPZ004777 mouse determines the resonance wavelength, but plasmon damping, as indicated by the homogeneous line width, also depends on the surface properties of the metal nanoparticles. Plasmon oscillations can decay through interband, intraband, radiation, and surface damping. While the first three damping mechanisms can be modeled based on bulk dielectric data using electromagnetic simulations, surface damping does not depend on the material properties of the nanoparticle alone but rather on the interface composition between the nanoparticle and its surrounding enise from an enhanced absorption, although charge transfer cannot be ruled out. From this body of research, we conclude that chemical interface damping is a major component of the total damping rate of the plasmon resonance and critically depends on the chemical interface of the metallic nanoparticles. Plasmon damping occurs through distinct mechanisms that are important to differentiate when considering the purpose of the plasmonic nanoparticle enhanced spectroscopy, energy conversion, or catalysis. It must also be noted that many of the mechanisms are currently indifferentiable, and thus, new single-particle spectroscopic methods are needed to further characterize the mechanisms underlying chemical interface damping.Since the advent of the first computers, chemists have been at the forefront of using computers to understand and solve complex chemical problems. As the hardware and software have evolved, so have the theoretical and computational chemistry methods and algorithms. Parallel computers clearly changed the common computing paradigm in the late 1970s and 80s, and the field has again seen a paradigm shift with the advent of graphical processing units. This review explores the challenges and some of the solutions in transforming software from the terascale to the petascale and now to the upcoming exascale computers. #link# While discussing the field in general, NWChem and its redesign, NWChemEx, will be highlighted as one of the early codesign projects to take advantage of massively parallel computers and emerging software standards to enable large scientific challenges to be tackled.The AMnO2 delafossites (A = Na, Cu) are model frustrated antiferromagnets, with triangular layers of Mn3+ spins. At low temperatures (TN = 65 K), a C2/m → P1̅ transition is found in CuMnO2, which breaks frustration and establishes magnetic order. In contrast to this clean transition, A = Na only shows short-range distortions at TN. Here, we report a systematic crystallographic, spectroscopic, and theoretical investigation of CuMnO2. We show that, even in stoichiometric samples, nonzero anisotropic Cu displacements coexist with magnetic order. Using X-ray/neutron diffraction and Raman scattering, we show that high pressures act to decouple these degrees of freedom. This manifests as an isostuctural phase transition at ∼10 GPa, with a reversible collapse of the c-axis. This is shown to be the high-pressure analogue of the c-axis negative thermal expansion seen at ambient pressure. Density functional theory (DFT) simulations confirm that dynamical instabilities of the Cu+ cations and edge-shared MnO6 layers are intertwined at ambient pressure.
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