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The study was to evaluate the effect of different storage methods on the ruminal degradation of nutrients and nutrients in purple prairie clover. Three Angus heifers fitted with permanent ruminal fistulas were used to determine the ruminal nutrient degradation characteristics of purple prairie clover stored in the forms of fresh grass (group F), hay (group H), silage (group S) and silage + polyethylene glycol (group SP) by ruminal nylon bag method. The results showed that silage significantly reduced the content of condensed tannins in purple prairie clover (P<0.05). The rumen degradation rate of crude protein (CP) ranked as group SP > group S > group F > group H at 2~24 h. The effective rumen degradation rate of dry matter (DM) was ranked as group SP > group F > group S > group H. The effective rumen degradation rate of CP was ranked as group SP > group S > group F > group H. The study indicates that purple prairie clover can better preserve the biological activity of condensed tannin (CT) when stored in the form of hay, reduce the ruminal degradation rate of CP, and have the potential to improve the utilization rate of protein in ruminant animals. [ABSTRACT FROM AUTHOR]

Under topological guidance, the self‐assembly process based on a tetratopic porphyrin synthon results in a hydrogen‐bonded organic framework (HOF) with the predicted square layers topology (sql) but unsatisfied stability. Strikingly, simply introducing a transition metal in the porphyrin center does not change the network topology but drastically causes noticeable change on noncovalent interaction, orbital overlap, and molecular geometry, therefore ultimately giving rise to a series of metalloporphyrinic HOFs with high surface area, and excellent stability (intact after being soaked in boiling water, concentrated HCl, and heated to 270 °C). On integrating both photosensitizers and catalytic sites into robust backbones, this series of HOFs can effectively catalyze the photoreduction of CO2 to CO, and their catalytic performances greatly depend on the chelated metal species in the porphyrin centers. This work enriches the library of stable functional HOFs and expands their applications in photocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]

A novel mononuclear copper(II)-flavonolate complex [Cu II L(fla)] (LH: 2-{[bis(pyridine-2-ylmethyl)-amino]methyl}-4-methoxy benzoic acid, flaH: flavonol) was prepared as a structural and functional model of the ES (enzyme-substrate) complex of Cu II -containing flavonol 2,4-dioxygenase. Its structure, properties and reactivity towards molecular dioxygen have been investigated in details. The complex shows the best reactivity in the copper(II)-flavonolate ES model system, may it could be contributed to the approximately monodentate coordination of the substrate flavonolate. [ABSTRACT FROM AUTHOR]

In order to get insights into the metal ion effects and the carboxylate effects on enzymatic activity, a series of the carboxylate ligand supported transition metal complexes [MIIL(OAc)] (M = Mn (1), Fe (2), Co (3), Ni (4), Cu (5) and Zn (6); LH = 2-{[bis-(pyridin-2-ylmethyl)amino]methyl}-4-methoxy benzoic acid) were synthesized and characterized as structural and functional models for the active sites of various MII-substituted resting quercetin 2,3-dioxygenases (2,3-QD). Their structures, spectroscopic features, redox properties, as well as the catalytic reactivity toward the substrate flavonol and O2 have been investigated in detail. The model complexes show higher enzymatic reactivities in the catalytic dioxygenation (oxidative ring opening) of the substrate flavonol at lower temperatures (55–100 °C), presumably caused by the carboxylate group in the supporting model ligand, which could lower the redox potential of the bound substrate flavonolate by electron donation. The catalytic reactivity of [MIIL(OAc)] exhibits notable differences and it is in a metal ion dependent order of Co (3) ＞ Ni (4) ＞ Zn (6) ＞ Fe (2) ＞ Mn (1) ＞ Cu (5). The differences in the reactivities among them could be ascribed to the redox potential of the bound substrate flavonolate, which was drastically influenced by the metal ions via tuning the electron density of flavonolate, providing important insights into the metal ion effects and the carboxylate effects on the enzymatic activity of various MII-substituted 2,3-QD. Our model complexes [MIIL(OAc)] are the first examples of a series of structural and functional models of various MII-substituted resting 2,3-QD. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to analyze the initial displacement of the maxillary first molar by tip back bend in Tip-Edge force system and to explore the relationships between the displacement and the degree or position of tip back bend. Methods The Tip-Edge three-dimensional finite element model was constructed by CT scan of a dry skull with all teeth. The conditions of five types of degree (20°, 30°, 40°, 50°, 60°) and four types of position (2, 4, 6, 8 mm) of tip back bend were added to the three-dimensional finite element model and the initial displacements of the maxillary first molar were calculated. Results Under the effect of tip back bend, distal and ex-trusive displacement of the maxillary first molar occurred. The distal and extrusive movement increased as the degree of tip back bend increased or the position of tip back bend moved distally. Conclusion The initial displacement of the maxillary first molar could be controlled by the precise control of the degree and position of tip back bend. [ABSTRACT FROM AUTHOR]

A two-dimensional metal-organic framework, FICN-12, was constructed from tris[4-(1 H -pyrazole-4-yl)phenyl]amine (H 3 TPPA) ligands and Ni 2 secondary building units. The triphenylamine moiety in the H 3 TPPA ligand readily absorbs UV-visible photons and sensitizes the Ni center to drive photocatalytic CO 2 reduction. FICN-12 can be exfoliated into monolayer and few-layer nanosheets with a "top-down" approach, which exposes more catalytic sites and increases its catalytic activity. As a result, the nanosheets (FICN-12-MONs) showed photocatalytic CO and CH 4 production rates of 121.15 and 12.17 μmol/g/h, respectively, nearly 1.4 times higher than those of bulk FICN-12.