Notes

Biallelic enhancing in the LOB1 promoter via CRISPR/Cas9 creates canker-resistant 'Duncan' grape fruit.
The energetics of small cationic tantalum clusters and their gas-phase adsorption and dehydrogenation reaction pathways with methane are investigated with ion-trap experiments and spin-density-functional-theory calculations. Tan+ clusters are exposed to methane under multicollision conditions in a cryogenic ring electrode ion-trap. The cluster size affects the reaction efficiency and the number of consecutively dehydrogenated methane molecules. Small clusters (n = 1-4) dehydrogenate CH4 and concurrently eliminate H2, while larger clusters (n > 4) demonstrate only molecular adsorption of methane. Unique behavior is found for the Ta+ cation, which dehydrogenates consecutively up to four CH4 molecules and is predicted theoretically to promote formation of a [Ta(CH2-CH2-CH2)(CH2)]+ product, exhibiting C-C coupled groups. Underlying mechanisms, including reaction-enhancing couplings between potential energy surfaces of different spin-multiplicities, are uncovered.Owing to their biocompatibility and biodegradability, short synthetic peptides that self-assemble into elongated β-sheet fibers (i.e., peptide nanofibers) are widely used to create biomaterials for diverse medical and biotechnology applications. Glycosylation, which is a common protein post-translational modification, is gaining interest for creating peptide nanofibers that can mimic the function of natural carbohydrate-modified proteins. Recent reports have shown that glycosylation can disrupt the fibrillization of natural amyloid-forming peptides. Here, using transmission electron microscopy, fluorescence microscopy, and thioflavin T spectroscopy, we show that glycosylation at a site external to the fibrillization domain can alter the self-assembly pathway of a synthetic fibrillizing peptide, NSGSGQQKFQFQFEQQ (NQ11). Specifically, an NQ11 variant modified with N-linked N-acetylglucosamine, N(GlcNAc)SGSG-Q11 (GQ11), formed β-sheet nanofibers more slowly than NQ11 in deionized water (pH 5.8), which correlated to the tendency of GQ11 to form a combination of short fibrils and nonfibrillar aggregates, whereas NQ11 formed extended nanofibers. Acidic phosphate buffer slowed the rate of GQ11 fibrillization and altered the morphology of the structures formed yet had no effect on NQ11 fibrillization rate or morphology. The buffer ionic strength had no effect on the fibrillization rate of either peptide, while the diphosphate anion had a similar effect on the rate of fibrillization of both peptides. JAK inhibitors in development Collectively, these data demonstrate that a glycan moiety located external to the β-sheet fibrillizing domain can alter the pH-dependent self-assembly pathway of a synthetic peptide, leading to significant changes in the fibril mass and morphology of the structures formed. These observations add to the understanding of the effect of glycosylation on peptide self-assembly and should guide future efforts to develop biomaterials from synthetic β-sheet fibrillizing glycopeptides.Seven novel bismuth(III)-halide phases, Bi2Cl6(terpy)2·0.5(H2O) (1), Bi2Cl4(terpy)2(k2-TC)2(2) (TC = 2-thiophene monocarboxylate), BiCl(terpy)(k2-TC)2 (3A-Cl), BiBr(terpy)(k2-TC)2 (3A-Br), BiCl(terpy)(k2-TC)2 (3B-Cl), [BiCl(terpy)(k2-TC)2][Bi(terpy)(k2-TC)3]·0.55(TCA) (4), [BiBr3(terpy)(MeOH)] (5), and [BiBr2(terpy)(k2-TC)][BiBr1.16(terpy)(k2-TC)1.84] (6), were prepared under mild synthetic conditions from methanolic/aqueous solutions containing BiX3 (X = Cl, Br) and 2,2'6',2″-terpyridine (terpy) and/or 2-thiophene monocarboxylic acid (TCA). A heterometallic series, 3A-Bi1-xEuxCl, with the general formula Bi1-xEuxCl(terpy)(k2-TC)2 (x = 0.001, 0.005, 0.01, 0.05) was also prepared through trace Eu doping of the 3A-Cl phase. The structures were determined through single-crystal X-ray diffraction and are built from a range of molecular units including monomeric and dimeric complexes. The solid-state photoluminescent properties of the compounds were examined through steady-state and time-resolved methods. While the homometallic phases exhibited broad green to yellow emission, the heterometallic phases displayed yellow, orange, and red emission that can be attributed to the simultaneous ligand/Bi-halide and Eu centered emissions. Photoluminescent color tuning was achieved by controlling the relative intensities of these concurrent emissions through compositional modifications including the Eu doping percentage. Notably, all emissive homo- and heterometallic phases exhibited rare visible excitation pathways that based on theoretical quantum mechanical calculations are attributed to halide-metal to ligand charge transfer (XMLCT). Through a combined experimental and computational approach, fundamental insight into the structure-property relationships within these Bi halide organic hybrid materials is provided.Density functional tight binding (DFTB) is an attractive method for accelerated quantum simulations of condensed matter due to its enhanced computational efficiency over standard density functional theory (DFT) approaches. However, DFTB models can be challenging to determine for individual systems of interest, especially for metallic and interfacial systems where different bonding arrangements can lead to significant changes in electronic states. In this regard, we have created a rapid-screening approach for determining systematically improvable DFTB interaction potentials that can yield transferable models for a variety of conditions. Our method leverages a recent reactive molecular dynamics force field where many-body interactions are represented by linear combinations of Chebyshev polynomials. This allows for the efficient creation of multi-center representations with relative ease, requiring only a small investment in initial DFT calculations. We have focused our workflow on TiH2 as a model system and show that a relatively small training set based on unit-cell-sized calculations yields a model accurate for both bulk and surface properties. Our approach is easy to implement and can yield reliable DFTB models over a broad range of thermodynamic conditions, where physical and chemical properties can be difficult to interrogate directly and there is historically a significant reliance on theoretical approaches for interpretation and validation of experimental results.The surface functionalization of nanoparticles (NPs) is of great interest for improving the use of NPs in, for example, therapeutic and diagnostic applications. The conjugation of specific molecules with NPs through the formation of covalent linkages is often sought to provide a high degree of colloidal stability and biocompatibility, as well as to provide functional groups for further surface modification. NPs of lithium niobate (LiNbO3) have been explored for use in second-harmonic-generation (SHG)-based bioimaging, expanding the applications of SHG-based microscopy techniques. The efficient use of SHG-active LiNbO3 NPs as probes will, however, require the functionalization of their surfaces with molecular reagents such as polyethylene glycol and fluorescent molecules to enhance their colloidal and chemical stability and to enable a correlative imaging platform. Herein, we demonstrate the surface functionalization of LiNbO3 NPs through the covalent attachment of alcohol-based reagents through a silanol-alco extended to other types of nanoprobes for use in bioimaging, biosensing, and photodynamic therapies.Here we report the use of pulse radiolysis and spectroelectrochemistry to generate low-valent nickel intermediates relevant to synthetically important Ni-catalyzed cross-coupling reactions and interrogate their reactivities toward comproportionation and oxidative addition processes. Pulse radiolysis provided a direct means to generate singly reduced [(dtbbpy)NiBr], enabling the identification of a rapid Ni(0)/Ni(II) comproportionation process taking place under synthetically relevant electrolysis conditions. This approach also permitted the direct measurement of Ni(I) oxidative addition rates with electronically differentiated aryl iodide electrophiles (kOA = 1.3 × 104-2.4 × 105 M-1 s-1), an elementary organometallic step often proposed in nickel-catalyzed cross-coupling reactions. Together, these results hold implications for a number of Ni-catalyzed cross-coupling processes.In the current study, we present nonadiabatic (NAMD) and adiabatic molecular dynamics simulations of the transition-state dynamics of photoexcited cyclooctatetraene (COT). The equilibrium-state structure and absorption spectra are analyzed using the semiempirical Austin Model 1 potential. The NAMD simulations are obtained by a surface-hopping algorithm. We analyzed in detail an active excited to ground state relaxation pathway accompanied by an S2/S3(D2d) → S1(D8h) → S0(D4h) → S0(D2d) double-bond shifting mechanism. The simulated excitation lifetime is in good agreement with experiment. The first excited singlet state S1 plays a crucial role in the photochemistry. The obtained critical molecular conformations, energy barrier, and transition-state lifetime results will provide a basis for further investigations of the bond-order inversion and photoswitching process of COT.Hepatocellular carcinoma (HCC) has high associated morbidity and mortality rates. Although chemical medication represents a primary HCC treatment strategy, low response rates and therapeutic resistance serve to reduce its efficacy. Hence, identifying novel effective drugs is urgently needed, and many researchers have sought to identify new anti-cancer drugs from marine organisms. The marine population is considered a "blue drug bank" of unique anti-cancer compounds with diverse groups of chemical structures. Here, we discuss marine-derived compounds, including PM060184 and bryostatin-1, with demonstrated anti-cancer activity in vitro or in vivo. Based on the marine source (sponges, algae, coral, bacteria, and fungi), we introduce pharmacological parameters, compound-induced cytotoxicity, effects on apoptosis and metastasis, and potential molecular mechanisms. Cumulatively, this review provides insights into anti-HCC research conducted to date in the field of marine natural products and marine-derived compounds, as well as the potential pharmacological mechanisms of these compounds and their status in drug development.Solution structure in liquid-liquid extraction affects the efficacy of separation; however, even for simplified organic phases, structural characterization and attribution of aggregation to intermolecular interactions are fundamental challenges. We investigate water uptake into organic phases for two malonamides commonly applied to actinide and lanthanide separations. Extracted water induces reorganization of the amphiphilic extractant molecules, although we find this rearrangement is not strongly manifested in small-angle X-ray scattering making it challenging to probe without methods such as atomistic simulation. Using a graph theoretic approach to define hydrogen bonded water/malonamide aggregates from molecular dynamics simulations, we find evidence of a characteristic aggregate size by water number that results from geometric accommodation of the surrounding malonamide molecules. This implies a degree of size selectivity inherent to these water-in-oil aggregates. Conversely, we find no evidence of a characteristic size of the aggregates with respect to their malonamide number.
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