Biphenyl-bridged 6-(1-aryliminoethyl)-2-iminopyridyl-cobalt complexes: synthesis, characterization and ethylene polymerization behavior

A series of biphenyl-bridged 6-(1-aryliminoethyl)-2-iminopyridine derivatives reacted with cobalt dichloride in dichloromethane/ethanol to afford the corresponding binuclear cobalt complexes. The cobalt complexes were characterized by FT-IR spectroscopy and elemental analysis, and the structure of a representative complex was confirmed by single-crystal X-ray diffraction. Upon activation with either MAO or MMAO, these cobalt complexes performed with high activities of up to 1.2 × 10⁷ g (mol of Co)⁻¹ h⁻¹ in ethylene polymerization, which represents one of the most active cobalt-based catalytic systems in ethylene reactivity. These biphenyl-bridged bis(imino)pyridylcobalt precatalysts exhibited higher activities than did their mononuclear bis(imino)pyridylcobalt precatalyst counterparts, and more importantly, the binuclear precatalysts revealed a better thermal stability and longer lifetimes. The polyethylenes obtained were characterized by GPC, DSC, and high-temperature NMR spectroscopy and mostly possessed unimodal and highly linear features

1,3-Bis[(4-nitro­benzyl­idene)amino­oxy]propane

The complete molecule of title compound, C17H16N4O6, is generated by a crystallographic twofold axis. Within the mol­ecule, the two benzene units are approximately perpen­dicular, making a dihedral angle of 85.91 (4)°. In the crystal, mol­ecules are linked into a three-dimensional network by C—H⋯O hydrogen bonds and short O⋯O and N⋯O inter­actions, with distances of 2.998 (2) and 2.968 (3) Å, respectively

A review of combined phacoemulsification and endoscopic cyclophotocoagulation: efficacy and safety

As cataract occurs frequently in patients with glaucoma, combining phacoemulsification and endoscopic cyclophotocoagulation has been gaining attention recently due to its minimally invasive nature. A variety of studies had evaluated the efficacy and safety of this procedure and had shown extremely promising results. This review article has shown here that combined phacoemulsification and endoscopic cyclophotocoagulation procedure could effectively reduce intraocular pressure in medically uncontrolled glaucoma patients while avoiding serious complications associated with traditional cyclophotocoagulation procedure and adverse effects related to filtering surgery such as trabeculectomy

Anti-tat Hutat2:Fc mediated protection against tat-induced neurotoxicity and HIV-1 replication in human monocyte-derived macrophages

Background: HIV-1 Tat is essential for HIV replication and is also a well-known neurotoxic factor causing HIV-associated neurocognitive disorder (HAND). Currently, combined antiretroviral therapy targeting HIV reverse transcriptase or protease cannot prevent the production of early viral proteins, especially Tat, once HIV infection has been established. HIV-infected macrophages and glial cells in the brain still release Tat into the extracellular space where it can exert direct and indirect neurotoxicity. Therefore, stable production of anti-Tat antibodies in the brain would neutralize HIV-1 Tat and thus provide an effective approach to protect neurons. Methods: We constructed a humanized anti-Tat Hutat2:Fc fusion protein with the goal of antagonizing HIV-1 Tat and delivered the gene into cell lines and primary human monocyte-derived macrophages (hMDM) by an HIV-based lentiviral vector. The function of the anti-Tat Hutat2:Fc fusion protein and the potential side effects of lentiviral vector-mediated gene transfer were evaluated in vitro. Results: Our study demonstrated that HIV-1-based lentiviral vector-mediated gene transduction resulted in a high-level, stable expression of anti-HIV-1 Tat Hutat2:Fc in human neuronal and monocytic cell lines, as well as in primary hMDM. Hutat2:Fc was detectable in both cells and supernatants and continued to accumulate to high levels within the supernatant. Hutat2:Fc protected mouse cortical neurons against HIV-1 Tat86-induced neurotoxicity. In addition, both secreted Hutat2:Fc and transduced hMDM led to reducing HIV-1BaL viral replication in human macrophages. Moreover, lentiviral vector-based gene introduction did not result in any significant changes in cytomorphology and cell viability. Although the expression of IL8, STAT1, and IDO1 genes was up-regulated in transduced hMDM, such alternation in gene expression did not affect the neuroprotective effect of Hutat2:Fc. Conclusions: Our study demonstrated that lentivirus-mediated gene transfer could efficiently deliver the Hutat2:Fc gene into primary hMDM and does not lead to any significant changes in hMDM immune-activation. The neuroprotective and HIV-1 suppressive effects produced by Hutat2:Fc were comparable to that of a full-length anti-Tat antibody. This study provides the foundation and insights for future research on the potential use of Hutat2:Fc as a novel gene therapy approach for HAND through utilizing monocytes/macrophages, which naturally cross the blood-brain barrier, for gene delivery. Electronic supplementary material The online version of this article (doi:10.1186/s12974-014-0195-2) contains supplementary material, which is available to authorized users

5,5′-Dimeth­oxy-2,2′-[(pentane-1,5-diyl­dioxy)bis­(nitrilo­methyl­idyne)]diphenol

The mol­ecule of the title compound, C21H26N2O6, which lies across a crystallographic inversion centre, crystallizes with two unique half-molecules in the symmetric unit and adopts a linear configuration and the imino group is coplanar with the aromatic ring, making a dihedral angle of 3.26 (3)°. Strong intra­molecular O—H⋯N and weak inter­molecular O—H⋯O and C—H⋯O hydrogen bonds and weak inter­molecular π–π stacking inter­actions [centroid–centroid distance = 4.419 (2) Å]establish an infinite three-dimensional supra­molecular structure

Interference theory of metamaterial perfect absorbers

The impedance matching in metamaterial perfect absorbers has been believed to involve and rely on magnetic resonant response, with a direct evidence from the anti-parallel directions of surface currents in the metal structures. Here we present a different theoretical interpretation based on interferences, which shows that the two layers of metal structure in metamaterial absorbers are linked only by multiple reflections with negligible near-field interactions or magnetic resonances. This is further supported by the out-of-phase surface currents derived at the interfaces of resonator array and ground plane through multiple reflections and superpositions. The theory developed here explains all features observed in narrowband metamaterial absorbers and therefore provides a profound understanding of the underlying physics.Comment: 8 pages, 4 figures, submitted to Optics Expres

2,2′-{1,1′-[Butane-1,4-diyl­bis(oxy­nitrilo)]di­ethylidyne}di-1-naphthol

The title compound, C28H28N2O4, was synthesized by the reaction of 2-acetyl-1-naphthol with 1,4-bis­(amino­oxy)butane in ethanol. The molecule, which lies about an inversion centre, adopts a linear structure, in which the oxime groups and naphthalene ring systems assume an anti conformation. The intra­molecular inter­planar distance between parallel naphthalene rings is 1.054 (3) Å. Intra­molecular O—H⋯N hydrogen bonds are formed between the oxime nitro­gen and hydr­oxy groups

{2,2′-[1,1′-(Ethyl­enedioxy­dinitrilo)diethyl­idyne]di-1-naphtholato}copper(II)

The title complex, [Cu(C26H22N2O4)], is isostructural with its Ni analogue. All intramolecular distances and angles are very similar for the two structures, whereas the packing of the molecules, including C—H⋯O and C—H⋯π interactions, are slightly different