Notes

Geomorphic effects of persistent outburst superfloods within the Yigong River on the south eastern border of Tibet.
The molecular dynamics calculations proposed that the intrinsic interaction with N-acetylglucosamine at the cell wall and the high-efficiency synergistic effect of sulfur-doped graphene and MoO x played the key role in inhibiting the viability of bacteria. This work provides new insights for a novel structure design and opens up a potential route to construct antibacterial agents with high efficiency for clinical application.Molecular motors, such as myosin, kinesin, and dynein, convert the energy released by the hydrolysis of ATP into mechanical work, thus allowing them to undergo directional motion on cytoskeletal tracks. A pivotal step in the chemomechanical transduction in myosin motors occurs after they bind to the actin filament, which triggers the release of phosphate (Pi, product of ATP hydrolysis) and the rotation of the lever arm. Here, we investigate the mechanism of phosphate release in myosin VI using extensive molecular dynamics simulations involving multiple trajectories of several μs. Because the escape of phosphate is expected to occur on time-scales on the order of milliseconds or more in myosin VI, we observed Pi release only if the trajectories were initiated with a rotated phosphate inside the nucleotide binding pocket. We discovered that although Pi populates the traditional "back door" route, phosphate exits through various other gateways, thus establishing the heterogeneity in the escape routes. Remarkably, we observed that the release of phosphate is preceded by a stepwise hydration of the ADP-bound magnesium ion. The release of the anion occurred only after four water molecules hydrated the cation (Mg2+). By performing comparative structural analyses, we show that hydration of magnesium is the key step in the phosphate release in a number of ATPases and GTPases. Nature may have evolved hydration of Mg2+ as a general molecular switch for Pi release, which is a universal step in the catalytic cycle of many machines that share little sequence or structural similarity.The final phase of the total synthesis of (-)-spirochensilide A is described. A tungsten-mediated cyclopropene-based Pauson-Khand reaction was developed to form the spiral CD ring system with desired stereochemistry at the C13 quaternary center. Other important steps enabling completion of this synthesis included an intermolecular aldol condensation to link the ABCD core with the EF fragment and a Cu-mediated 1,4-addition to stereoselectively install the C21 stereogenic center. The chemistry developed for this total synthesis of (-)-spirochensilide A (1) will aid the synthesis of polycyclic natural products bearing this unique spiral ring system.Sclerotinia sclerotiorum is a ubiquitous necrotrophic pathogenic fungus causing significant losses in a broad range of plant species. Sclerotia formed by S. sclerotiorum play important roles in both the fungal life cycle and the disease development cycle. Sclerotial exudation during sclerotial development is a characteristic feature of this fungus. In this study, a proteome-level investigation of proteins present in sclerotial exudates was conducted by high-throughput LC-MS/MS analysis. A total of 258 proteins were identified, in which 193 were annotated by GO annotation and 54 were classified by KEGG analysis. Four proteins related to plant cell wall degradation were further validated by measuring the corresponding enzymatic activity of the sclerotial exudates and/or by assessing the gene expression during sclerotial development. AZ32 Results indicated that the proteins identified in sclerotial exudates help in the development of sclerotia and contribute to host cell necrosis caused by S. sclerotiorum. Furthermore, we proposed that sclerotial exudates can degrade plant cell walls to release carbohydrates that provide nutrition for fungal growth and possibly facilitate fungal cell wall assembly in developing sclerotia. This study also provides new insights on the morphogenesis and pathogenicity of other sclerotia-forming fungi.A regiodivergent C-H arylation of triphenylene derivatives with diaryliodonium salts was developed. The regiodivergence was controlled by electronic effects of diaryliodonium salts. When the aryl(mesityl)iodonium salts bearing strong electron-donating groups at the para-position of aryl groups were used, the arylation reactions occurred ortho to amide groups. However, if the aryl(mesityl)iodonium salts bearing electron-withdrawing groups or weak electron-donating groups at the para-position of aryl groups were utilized, the arylation reactions occurred meta to amide groups.The occurrence of anthocyanin (ACN) and metal (Me) complexes has been widely supported by many research works while the possibility that ACNs bind to metalloids (Mds) is yet to be proven. Here, metalloids (H3BO3 for B; GeO2 for Ge) were added to cyanidin-based solutions at pH 5, 6, and 7 and ACN-Md stoichiometric ratios of 11, 110, 1100, and 1500, and UV-vis transmittance spectroscopy as well as density functional theory (DFT) calculations were performed to test this hypothesis. Ge and B addition caused bathochromic and hyperchromic shifts on ACN UV-vis spectra, particularly pronounced at pH 5 and a 1500 (ACNMd) ratio. ACN-Me complexation reactions have been evaluated where Ge showed a higher capability to bind to ACNs than B. Among the complexes envisioned, those labeled as b1, b2, and b3 feature UV-vis spectra compatible with experiments. The combination of experimental and computational data offers for the first time evidence of the formation of ACN-Md complexes.Fuzhuan brick tea (FBT), one of the unique dark teas, has various health-promoting functions. In the present study, one polysaccharide fraction, namely FBTPS-2-1, was extracted and purified from FBT, and its structure and potential immunostimulatory activity were investigated. The results showed that FBTPS-2-1,one of typical heteropolysaccharides, was mainly composed of Gal, Ara, and Glc with little molar content of Man, Rha, GalA, and GlcA in molar ratio of 46.5922.1313.578.206.022.121.38 and molecular weight of 748 kDa. The backbone of FBTPS-2-1 contained →4)-β-d-Galp-(1→4)-β-d-Galp-(1→, →4)-β-d-Galp-(1→4)-α-d-Glcp-(1→, →4)-α-d-Glcp-(1→4)-α-d-Glcp-(1→, →4)-α-d-Glcp-(1→4)-β-d-Galp-(1→, →3)-β-d-Galp-(1→4)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→3)-β-d-Galp-(1→ and →3,6)-β-d-Galp-(1→3,6)-β-d-Galp-(1→. The linkages of branches in FBTPS-2-1 were mainly composed of α-l-Araf-(1→3,6)-β-d-Galp-(1→, →5)-α-l-Araf-(1→3,6)-β-d-Galp-(1→, →6)-β-d-Galp-(1→3,6)-β-d-Galp-(1→, α-l-Araf-(1→3,5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→5)-α-l-Araf-(1→, α-d-Galp-(1→3,5)-α-l-Araf-(1→ and →5)-α-l-Araf-(1→6)-β-d-Galp-(1→. Furthermore, FBTPS-2-1 could increase the phagocytosis of macrophages and promote the secretion of NO and a variety of inflammatory cytokines, including TNF-α, IL-1β, and IL-6, indicating noticeable immune enhancement activity. Thus, FBTPS-2-1 could serve as a potentially functional food to improve human health by modulating the host immunoreaction.Engineering antibodies to improve target specificity, reduce detection limits, or introduce novel functionality is an important research area for biosensor development. While various affinity biosensors have been developed to generate an output signal upon varying analyte concentrations, reversible and continuous protein monitoring in complex biological samples remains challenging. Herein, we explore the concept of directed evolution to modulate dissociation kinetics of a high affinity anti-epidermal growth factor receptor (EGFR) single-chain variable antibody fragment (scFv) to enable continuous protein sensing in a label-free binding assay. A mutant scFv library was generated from the wild type (WT) fragment via targeted permutation of four residues in the antibody-antigen-binding interface. A single round of phage display biopanning complemented with high-throughput screening methods then permitted isolation of a specific binder with fast reaction kinetics. We were able to obtain ∼30 times faster dissociation rates when compared to the WT without appreciably affecting overall affinity and specificity by targeting a single paratope that is known to contribute to the binding interaction. Suitability of a resulting mutant fragment to sense varying antigen concentrations in continuous mode was demonstrated in a modified label-free binding assay, achieving low nanomolar detection limits (KD = 8.39 nM). We also confirmed these results using an independent detection mechanism developed previously by our group, incorporating a polarity-dependent fluorescent dye into the scFv and reading out EGFR binding based on fluorescence wavelength shifts. In future, this generic approach could be employed to generate improved or novel binders for proteins of interest, ready for deployment in a broad range of assay platforms.Starch biosynthesis in cereal crops is a complex pathway regulated by multiple starch synthetic enzymes. Starch synthase IIa (SSIIa) is well-known to be one of the major starch synthases and is very important in amylopectin biosynthesis. It has significant effects on grain composition and kernel traits. However, there are few reports on the association of natural variation of SSIIa in barley and grain composition and characteristics. In this work, two SSIIa isoforms were first identified as SSIIaH and SSIIaL by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, mass spectrometry, and Western blotting. Sequence analysis of the SSIIa gene demonstrated that a 33 bp insertion coding a peptide of APPSSVVPAKK caused different SSIIa, e.g., SSIIaH and SSIIaL. Based on this molecular difference, a polymerase chain reaction marker was developed, which could be used to screen different SSIIa genotypes easily. Kernel hardness of SSIIaL genotypes was significantly higher than that of SSIIaH Chinese barley cultivars. The proportion of SSIIaL genotypes was extremely low in Australian barley cultivars (5/24) and much higher in Tibetan hull-less barley cultivars (46/74), consistent with the end-use requirements of barley grain. This study provided new information in barley endosperm starch synthesis and indicated that it is valuable for choosing the preferred SSIIa genotype according to the end-use requirements.Determining local concentrations of the analytes in state-of-the-art microreactors is essential for the development of optimized and safe processes. However, the selective, parallel monitoring of all relevant reactants and products in a multianalyte environment is challenging. Electrochemical microsensors can provide unique information on the reaction kinetics and overall performance of the hydrogen peroxide synthesis process in microreactors, thanks to their high spatial and temporal resolution and their ability to measure in situ, in contrast to other techniques. We present a chronoamperometric approach which allows the selective detection of the dissolved gases hydrogen and oxygen and their reaction product hydrogen peroxide on the same platinum microelectrode in an aqueous electrolyte. The method enables us to obtain the concentration of each analyte using three specific potentials and to subtract interfering currents from the mixed signal. While hydrogen can be detected independently, no potentials can be found for a direct, selective measurement of oxygen and hydrogen peroxide.
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