Highly stable olefin-Cu(I) coordination oligomers and polymers

Highly stable Cu(I)-olefin coordination oligomers and polymers have been successfully prepared and applied to construct metal-organic frameworks (MOFs) with interesting physical and chemical functions in recent years. In this review, we present the olefin-Cu(I) coordination oligomers and polymers and their novel physical properties. From structure to functions, particular emphasis is placed on the coordination and organometallic chemistry of olefin-Cu(I) coordination oligomers and polymers, their structures and potential applications as solids possessing unusual physical functional properties such as electrochemical, chiral separation, fluorescent sensing and ferroelectricity.     

The first metal (Nd3+, Mn2+, and Pb2+) coordination compounds of 3,5-dinitrotyrosine and their nonlinear optical properties

The reactions of 3,5-dinitrotyrosine (H2DNTY) with Nd(NO3)3.6H2O, Mn(ClO4)2.6H2O, and Pb(OAc)2 afforded three homochiral compounds: discrete [Nd(Hdnty)2(NO3)(H2O)5].3H2O (1) and two- and three-dimensional coordination polymers, [Mn(Hdnty)2] (2) and [Pb(dnty)(0.5 H2O)] (3), respectively. The Nd atom in 1 displays a tricapped trigonal prism and supramolecular weak interactions, such as pi-pi stacking and H-bonds, between amino and nitro groups result in the formation of a three-dimensional network through these interactions. 2 has a two-dimensional square-grid topological net while 3 has the first three-dimensional homochiral ThSi2 net. To the best of our knowledge, these are the first metal coordination compounds with 3,5-dinitrotyrosine. Preliminary second harmonic generation (SHG) investigations indicated that 1 and 2 are SHG active with estimated responses 5 and 6 times larger than that of urea, respectively, while 3 is SHG non-active (obeying the Klainman symmetry requirement). Strong enhancement of their SHG efficiency, compared with H2DNTY, may be due to 1) the addition of a good donor-pi-acceptor organic chromophore into the compound resulting in superior qualities of both inorganic and organic materials and 2) the H-bonds that persist in them. Crystal data: 1: C18H32N7O25Nd, Mr = 890.75 g mol(-1), monoclinic, P2(1), a=7.0179(7), b=27.060(3), c=8.3097(8) A, alpha=gamma=90.00, beta=95.646(2) degrees , V=1570.4(3) A(3), Z=2, rho(calcd)=1.884 Mg m(-3), R(1)=0.0489, wR(2)=0.1223, mu=17.67 mm(-1), S=0.811, Flack value=0.003(13); 2: C(18)H(16)N(6)O(14)Mn, M(r)=595.31 g mol(-1), orthorhombic, P2(1)2(1)2, a=8.4381(14), b=13.639(2), c=19.697(3) A, alpha=beta=gamma=90.00 degrees , V=2266.9(6) A(3), Z=4, rho(calcd)=1.744 Mg m(-3), R(1)=0.0866, wR(2)=0.2030, mu=6.72 mm(-1), S=1.095, Flack value=0.02(6); 3: C(9)H(8)N(3)O(7.5)Pb, M(r)=485.37 g mol(-1), tetragonal, P4(1)2(1)2, a=12.8136(12), b=12.8136(12), c=14.931(2), alpha=beta=gamma=90.00 degrees , V=2451.5(5) A(3), Z=8, rho(calcd)=1.885 Mg m(-3), R(1)=0.0564, wR(2)=0.1323, mu=6.942 mm(-1), S=0.878, Flack value=0.03(2). For space group P4(3)2(1)2: R(1)=0.0672, wR(2)=0.1656, S=1.034, Flack value=1.02(3); this suggests the chosen space group P4(1)2(1)2 is correct.     

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry studies of low molecular weight dendrimers

We report the application of matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry, with delayed extraction in the reflectron mode, for the characterization of low molecular weight dendrimers. 20 dendrimer samples were measured and 4 typical dendrimers, as examples, are discussed in detail. Several factors that affect the analysis including the matrices used, the concentrations of sample, the solvents and cationization reagent used, were investigated in detail. Experimental results indicate that the type of solvent can greatly influence exact mass measurement. However, sample preparation is generally not very critical for dendrimer analysis using MALDI-ToF since many kinds of matrices and a wide range of sample concentrations can be used efficiently. In addition, the Cs(+) ion can be used to enhance the efficiency of cationization. Some reasons for this behavior are discussed on the basis of results of calculations using Gaussian94 software (a connected system of programs for performing a variety of semi-empirical and ab initio molecular orbital (MO) calculations).     

SET8 suppression mediates high glucose-induced vascular endothelial inflammation via the upregulation of PTEN

Hyperglycemia-mediated endothelial inflammation participates in the pathogenesis of cardiovascular complications in subjects with diabetes. Previous studies reported that phosphatase and tensin homolog deleted on chromosome ten (PTEN) and SET8 participate in high glucose-mediated endothelial inflammation. In this study, we hypothesize that SET8 regulates PTEN expression, thus contributing to high glucose-mediated vascular endothelial inflammation. Our data indicated that plasma soluble intercellular adhesion molecule-1 (sICAM-1) and endothelial selectin (e-selectin) were increased in patients with diabetes and diabetic rats. PTEN expression was augmented in the peripheral blood mononuclear cells of patients with diabetes and in the aortic tissues of diabetic rats. Our in vitro study indicated that high glucose increased monocyte/endothelial adhesion, endothelial adhesion molecule expression and p65 phosphorylation in human umbilical vein endothelial cells (HUVECs). Moreover, high glucose led to endothelial inflammation via upregulation of PTEN. Furthermore, high glucose inhibited SET8 expression and histone H4 lysine 20 methylation (H4K20me1), a downstream target of SET8. SET8 overexpression reversed the effects of high-glucose treatment. shSET8-mediated endothelial inflammation was counteracted by siPTEN. Furthermore, SET8 was found to interact with FOXO1. siFOXO1 attenuated high glucose-mediated endothelial inflammation. FOXO1 overexpression-mediated endothelial inflammation was counteracted by siPTEN. H4K20me1 and FOXO1 were enriched in the PTEN promoter region. shSET8 increased PTEN promoter activity and augmented the positive effect of FOXO1 overexpression on PTEN promoter activity. Our in vivo study indicated that SET8 was downregulated and FOXO1 was upregulated in the peripheral blood mononuclear cells of patients with diabetes and the aortic tissues of diabetic rats. In conclusion, SET8 interacted with FOXO1 to modulate PTEN expression in vascular endothelial cells, thus contributing to hyperglycemia-mediated endothelial inflammation.Subject terms: Diabetes complications, Vascular diseases     

Molecular modeling on recognition of sheared and normal DNA by novel metal complex Λ- and Δ-[Co(phen)2hpip]

Recognition of sheared and normal DNA by a novel metal complex [Co(phen)₂hpip]³⁺ (phen=1,10-phenanthroline, HPIP=2-(2-hydroxyphenyl)imidazole[4,5-f][1,10]phenanethroline) is studied by molecular modeling. Calculating results indicate that, this complex can specifically recognize DNA segment of sequence –MMNNMM– (M means mismatch base pairs and N means normal base pairs). Intercalating from minor groove between the middle normal duplex into the sheared DNA with the depth of 1.2 nm is of preference and enantioselectivity is observed. Comparison on the two DNA structures of optimal conformation and analysis on the interaction between DNA and the two tail ligands of the complex show that, the effect of the two neighboring mismatch duplexes on the structure of the middle normal base pairs and the steric interaction between the mismatch duplexes and the two tail ligands of the complex are the essential reason to the segment specificity. Investigation on the detailed energy terms indicate that, in effecting enantioselectivity, the electrostatic distribution of the complex is in the majority and steric interaction is at the next place. But, steric interaction is surely the only factor determining the intercalating from minor groove.     

A Novel Catalyst for Liquid Phase Hydrogenation of m-Dinitrobenzene to m-Phenylenediamine

A novel lanthana-promoted nickel catalyst supported on silica for the liquid phase hydrogenation of m-dinitrobenzene to m-phenylenediamine was prepared by an incipient wetness sequential impregnation method. It was found that Ni-La/SiO2 catalyst exhibited high activity and stability for m-dinitrobenzene hydrogenation. Over this catalyst, the conversion of m-dinitrobenzene and the yield of m-phenylenediamine were up to 97.1% and 93.5%, respectively,at 373 K and 2.6 MPa hydrogen pressure after reaction for 1 h.     

Furostanol saponins with inhibitory action against COX-2 production from Tupistra chinensis rhizomes

Two furostanol saponins were obtained from the n-butanol fraction of methanol extract from Tupistra chinensis rhizomes,a folk medicine of Shennongjia Forest District of Hubei Province.Their structures were determined as (25S)-26-O-(β-D-glucopyranosyl)- furost-1β,3β,22α,26-tetrol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (1) and (25R)- 26-O-(β-D-glucopyranosyl)-furost-1β,3β22α,26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glu- copyranoside (2),on basis of chemical and spectroscopic evidences.1 and 2 displayed marked inhibitory action towards COX-2 production in macrophages of the rat abdomen induced by LPS at 20μg/mL.     

An Improved Human-Body-Segmentation Algorithm with Attention-Based Feature Fusion and a Refined Stereo-Matching Scheme Working at the Sub-Pixel Level for the Anthropometric System

This paper proposes an improved human-body-segmentation algorithm with attention-based feature fusion and a refined corner-based feature-point design with sub-pixel stereo matching for the anthropometric system. In the human-body-segmentation algorithm, four CBAMs are embedded in the four middle convolution layers of the backbone network (ResNet101) of PSPNet to achieve better feature fusion in space and channels, so as to improve accuracy. The common convolution in the residual blocks of ResNet101 is substituted by group convolution to reduce model parameters and computational cost, thereby optimizing efficiency. For the stereo-matching scheme, a corner-based feature point is designed to obtain the feature-point coordinates at sub-pixel level, so that precision is refined. A regional constraint is applied according to the characteristic of the checkerboard corner points, thereby reducing complexity. Experimental results demonstrated that the anthropometric system with the proposed CBAM-based human-body-segmentation algorithm and corner-based stereo-matching scheme can significantly outperform the state-of-the-art system in accuracy. It can also meet the national standards GB/T 2664-2017, GA 258-2009 and GB/T 2665-2017; and the textile industry standards FZ/T 73029-2019, FZ/T 73017-2014, FZ/T 73059-2017 and FZ/T 73022-2019.     

Mitochondrial citrate accumulation drives alveolar epithelial cell necroptosis in lipopolysaccharide-induced acute lung injury

Necroptosis is the major cause of death in alveolar epithelial cells (AECs) during acute lung injury (ALI). Here, we report a previously unrecognized mechanism for necroptosis. We found an accumulation of mitochondrial citrate (citrate^mt) in lipopolysaccharide (LPS)-treated AECs because of the downregulation of Idh3α and citrate carrier (CIC, also known as Slc25a1). shRNA- or inhibitor–mediated inhibition of Idh3α and Slc25a1 induced citrate^mt accumulation and necroptosis in vitro. Mice with AEC-specific Idh3α and Slc25a1 deficiency exhibited exacerbated lung injury and AEC necroptosis. Interestingly, the overexpression of Idh3α and Slc25a1 decreased citrate^mt levels and rescued AECs from necroptosis. Mechanistically, citrate^mt accumulation induced mitochondrial fission and excessive mitophagy in AECs. Furthermore, citrate^mt directly interacted with FUN14 domain-containing protein 1 (FUNDC1) and promoted the interaction of FUNDC1 with dynamin-related protein 1 (DRP1), leading to excessive mitophagy-mediated necroptosis and thereby initiating and promoting ALI. Importantly, necroptosis induced by citrate^mt accumulation was inhibited in FUNDC1-knockout AECs. We show that citrate^mt accumulation is a novel target for protection against ALI involving necroptosis.Subject terms: Infection, Respiratory tract diseases