RESUMO
Interest in chiral substances has mainly focused on the substances themselves, but not on the accompanying space, especially regarding the pore alignment. As a method to form both the chiral substance and the accompanying space, cylindrical self-assembly of uniform polystyrene nanoparticles with fructose is carried out in the presence of both carbon and sodium alginate, which is followed by heat treatment in an inert atmosphere. The carbonization generates fructose-derived honeycomb-like carbon walls with helically aligned nanopores left after the polystyrene decomposition. The diffuse reflectance circular dichroism measurements give peaks with opposite signs for the d- and l-fructose-derived cylindrical carbons. Circularly polarized light sensitivity in transient photoconductivity is confirmed apparently in the carbon-based helical structures. This sensitivity as well as straightforward formation of composites with another component to give helicity shows potential applications of the helically aligned pores.
RESUMO
OBJECTIVE: n-3 polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have beneficial effects on atherosclerosis. Although specific salutary actions have been reported, the detailed distribution of n-3 polyunsaturated fatty acids in plaque and their relevance in disease progression are unclear. Our aim was to assess the pharmacodynamics of EPA and DHA and their metabolites in atherosclerotic plaques. Approach and Results: Apolipoprotein E-deficient (Apoe-/-) mice were fed a Western diet supplemented with EPA (1%, w/w) or DHA (1%, w/w) for 3 weeks. Imaging mass spectrometry analyses were performed in the aortic root and arch of the Apoe-/- mice to evaluate the distribution of EPA, DHA, their metabolites and the lipids containing EPA or DHA in the plaques. Liquid chromatography-mass spectrometry and histological analysis were also performed. The intima-media thickness of atherosclerotic plaque decreased in plaques containing free EPA and EPAs attached with several lipids. EPA was distributed more densely in the thin-cap plaques than in the thick-cap plaques, while DHA was more evenly distributed. In the aortic root, the distribution of total EPA level and cholesteryl esters containing EPA followed a concentration gradient from the vascular endothelium to the media. In the aortic arch, free EPA and 12-hydroxy-EPA colocalized with M2 macrophage. CONCLUSIONS: Administered EPA tends to be incorporated from the vascular lumen side and preferentially taken into the thin-cap plaque.
Assuntos
Ácido Eicosapentaenoico/administração & dosagem , Placa Aterosclerótica/tratamento farmacológico , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/metabolismo , Animais , Ésteres do Colesterol/metabolismo , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/metabolismo , Ácido Eicosapentaenoico/farmacologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Placa Aterosclerótica/metabolismo , Túnica Íntima/patologiaRESUMO
The recent growing interest in the applications of gold nanowires (AuNWs) as flexible materials has raised the fundamental issue of how their mechanical properties are related to their morphology. In this work, to address this issue, the systematic synthesis of AuNWs, their structural analysis, and their rheological investigation were demonstrated. The structural analysis of AuNWs was performed based on TEM observations and light-scattering experiments. From these observations, it was found that the length of AuNWs varies from nanometer to micrometer depending on the reaction time while a constant width of 1.6 nm is maintained. On the basis of static light-scattering experiments and a wormlike chain model, the structural parameters of AuNWs during their growth were successfully obtained. When the contour length of AuNWs reached around 5 µm, the AuNW solution showed non-Newtonian behavior and appeared to behave as a gel. Dynamic viscoelasticity measurements indicated that such viscous behavior is responsible for entanglement between AuNWs. It is concluded that AuNWs are analogous with conventional polymers in terms of both their structure and their rheological behavior.
RESUMO
We discovered the unique cell adhesive properties of ultraviolet (UV)-irradiated albumin films. Albumin films prepared using a cross-linking reagent with epoxy groups maintained native albumin properties, such as resistance to cell adhesion. Interestingly, the cell adhesive properties of films varied depending upon the UV irradiation time; specifically, cell adhesiveness increased until 2 h of UV irradiation, when the cell number attached to the film was similar to that of culture dishes, and then cell adhesiveness decreased until 20 h of UV irradiation, after which the surface returned to the initial non-adhesive state. To elucidate the molecular mechanisms underlying this phenomenon, we examined the effect of UV irradiation on albumin film properties. The following changes occurred in response to UV irradiation: decreased α-helical structure, cleavage of albumin peptide bonds, and increased hydrophilicity and oxygen content of the albumin film surface. In addition, we found a positive correlation between the degree of cell adhesion and the amount of fibronectin adsorbed on the film. Taken together, UV-induced changes in films highly affect the amount of cell adhesion proteins adsorbed on the films depending upon the irradiation time, which determines cell adhesion behavior.
Assuntos
Albuminas/química , Raios Ultravioleta , Adesividade , Membranas ArtificiaisRESUMO
The asymmetric unit of the title compound is composed of two independent ion pairs of 4-(di-methyl-amino)-pyridin-1-ium 8-hy-droxy-quinoline-5-sulfonate (HDMAP+·HqSA-, C7H11N2 +·C9H6NO4S-) and neutral N,N-di-methyl-pyridin-4-amine mol-ecules (DMAP, C7H10N2), co-crystallized as a 1:1:1 HDMAP+:HqSA-:DMAP adduct in the monoclinic system, space group Pc. The compound has a layered structure, including cation layers of HDMAP+ with DMAP and anion layers of HqSA- in the crystal. In the cation layer, there are inter-molecular N-Hâ¯N hydrogen bonds between the protonated HDMAP+ mol-ecule and the neutral DMAP mol-ecule. In the anion layer, each HqSA- is surrounded by other six HqSA-, where the planar network structure is formed by inter-molecular O-Hâ¯O and C-Hâ¯O hydrogen bonds. The cation and anion layers are linked by inter-molecular C-Hâ¯O hydrogen bonds and C-Hâ¯π inter-actions.
RESUMO
The title copper(II) complex, [Cu(C18H19N3O3)(C3H4N2)], consists of a tridentate ligand synthesized from l-leucine and azo-benzene-salicyl-aldehyde. One imidazole mol-ecule is additionally coordinated to the copper(II) ion in the equatorial plane. The crystal structure features N-Hâ¯O hydrogen bonds. A Hirshfeld surface analysis indicates that the most important contributions to the packing are from Hâ¯H (52.0%) and Câ¯H/Hâ¯C (17.9%) contacts.
RESUMO
In the title compound, [Na(C22H19N4O4S)(CH3CN)]n, the NaI atom adopts a distorted square-pyramidal coordination geometry, formed by one N and one O atom of the qunolinol moiety in the ligand, two O atoms of sulfonate moieties of two adjacent ligands and the N atom of the coordinated aceto-nitrile solvent. The NaI atom is located well above the mean basal plane of the square-based pyramid. The apical position is occupied by a sulfonate O atom of a neighboring ligand. Three N atoms of the bis-(pyridin-2-ylmeth-yl)amine moiety in the ligand are not coordinated by the sodium atom. The mol-ecule forms an intra-molecular bifurcated O-Hâ¯[N(tertiary amine),N(pyridine)] hydrogen bond, generating S(6) and S(5) rings. In the crystal, four mol-ecules are linked by four Na-O(sulfonato) bridged coordination bonds, forming a supra-molecular centrosymmetric tetra-mer unit comprising an eight-membered ring, and generating a two-dimensional network sheet. The mol-ecules of different sheets form inter-molecular C-Hâ¯O hydrogen bonds, and thereby a three-dimensional network structure.
RESUMO
In the title compound, [ZnBr2(C22H19ClN4O)], the ZnII atom adopts a distorted square-pyramidal coordination geometry, formed by two bromido ligands and three N atoms of the bis-(pyridin-2-ylmeth-yl)amine moiety in the penta-dentate ligand containing quinolinol. The ZnII atom is located well above the mean basal plane of the square-based pyramid. The apical position is occupied by a Br atom. The O and N atoms of the quinolinol moiety in the ligand are not coordinated to the ZnII atom. An intra-molecular O-Hâ¯N hydrogen bond, generating an S(5) ring motif, stabilizes the mol-ecular structure. In the crystal, the mol-ecules are linked by inter-molecular C-Hâ¯Br hydrogen bonds, generating ribbon structures containing alternating R 2 2(22) and R 2 2(14) rings. These ribbons are linked through an inter-molecular C-Hâ¯Br hydrogen bond, forming a two-dimensional network sheet.
RESUMO
The title compound, C33H33N3, is a carbazolophane, which is a cyclo-phane composed of two carbazole fragments. It has a planar chirality but crystallizes as a racemate in the space group P . The mol-ecule adopts an anti-configuration, in which two carbazole fragments are partially overlapped. Both carbazole ring systems are slightly bent, with the C atoms at 3-positions showing the largest deviations from the mean planes. The dihedral angle between two carbazole fragments is 5.19â (3)°, allowing an intra-molecular slipped π-π inter-action [Cgâ¯Cg = 3.2514â (8)â Å]. In the crystal, the mol-ecules are linked via inter-molecular C-Hâ¯N hydrogen bonds and C-Hâ¯π inter-actions into a network sheet parallel to the ab plane. The mol-ecules of different sheets form other C-Hâ¯π inter-actions, thus forming a three-dimensional network.
RESUMO
The mol-ecule of the title compound, C16H14N2O, contains an essentially planar indole ring system and a phenyl ring. In the crystal, the mol-ecules are linked by a weak inter-molecular C-Hâ¯O hydrogen bond and C-Hâ¯π inter-actions, forming a one-dimensional column structure along the b-axis direction. These columns are linked by other C-Hâ¯π inter-actions, forming a two-dimensional network structure.
RESUMO
While the functions of carbon materials with precisely controlled nanostructures have been reported in many studies, their chiral discriminating abilities have not been reported yet. Herein, chiral discrimination is achieved using helical carbon materials devoid of chiral attachments. A Fe3O4 nanoparticle template with ethyl cellulose (carbon source) is self-assembled on dispersed multiwalled carbon nanotubes (MWCNTs) fixed in a lamellar structure, with helical nanoparticle alignment induced by the addition of a binaphthyl derivative. Carbonization followed by template removal produces helically aligned fused carbon hollow nanospheres (CHNSs) with no chiral molecules left. Helicity is confirmed using vacuum-ultraviolet circular dichroism spectroscopy. Chiral discrimination, as revealed by the electrochemical reactions of binaphthol and a chiral ferrocene derivative in aqueous and nonaqueous electrolytes, respectively, is attributable to the chiral space formed between the CHNS and MWCNT surfaces.
RESUMO
In the title compound, C24H15Cl2N3O2, one quinoline ring system is essentially planar and the other is slightly bent. An intra-molecular O-Hâ¯N hydrogen bond involving the hy-droxy group and a pyridine N atom forms an S(5) ring motif. In the crystal, two mol-ecules are associated into an inversion dimer with two R 2 2(7) ring motifs through inter-molecular O-Hâ¯N and O-Hâ¯O hydrogen bonds. The dimers are further linked by an inter-molecular C-Hâ¯O hydrogen bond and four C-Hâ¯π inter-actions, forming a two-dimensional network parallel to (001).
RESUMO
The title crystalline compound, [Cu2(NCS)2(C9H16N2)2], was obtained from the reaction of copper(I) thio-cyanate (CuSCN) with (N-prop-2-en-1-yl)piperidine-1-carbo-thio-amide as a chelating and bridging thio-urea ligand in chloro-benzene. The Cu2S2 core of the dimeric mol-ecule is situated on a crystallographic inversion centre. The copper atom is coordinated by a thio-cyanate nitro-gen atom, each sulfur atom of the two thio-urea ligands, and the C=C double bond of the ligand in a distorted tetra-hedral geometry. The dimers are linked by N-Hâ¯S hydrogen bonds, forming a network extending in two dimensions parallel to (100).
RESUMO
In the title mol-ecule, C48H33N, the central N atom shows no pyramidalization, so that the N atom and the three C atoms bound to the N atom lie almost in the same plane. The three para-phenyl-ene rings bonded to the N atom are in a propeller form. All of the naphthalene ring systems are slightly bent. In the crystal, mol-ecules form an inversion dimer, through two pairs of C-Hâ¯π inter-actions, which further inter-acts with the adjacent dimer via another two pairs of C-Hâ¯π inter-actions, forming a column structure along the a axis. There are no significant inter-actions between these column structures.
RESUMO
The reaction of bis-(3-oxo-1,3-di-phenyl-prop-1-enolato-κ2 O,O')zinc(II), [Zn(dbm)2], with tris-[4-(pyridin-3-yl)phen-yl]amine (T3PyA) in tetra-hydro-furan (THF) afforded the title crystalline coordination polymer, {[Zn(C15H11O2)2(C33H24N4)]·C4H8O} n . The asymmetric unit contains two independent halves of Zn(dbm)2, one T3PyA and one THF. Each ZnII atom is located on an inversion centre and adopts an elongated octa-hedral coordination geometry, ligated by four O atoms of two dbm ligands in equatorial positions and by two N atoms of pyridine moieties from two different bridging T3PyA ligands in axial positions. The crystal packing shows a one-dimensional polymer chain in which the two pyridyl groups of the T3PyA ligand bridge two independent Zn atoms of Zn(dbm)2. In the crystal, the coordination polymer chains are linked via C-Hâ¯π inter-actions into a sheet structure parallel to (010). The sheets are cross-linked via further C-Hâ¯π inter-actions into a three-dimensional network. The solvate THF mol-ecule shows disorder over two sets of atomic sites having occupancies of 0.631â (7) and 0.369â (7).
RESUMO
Controlled thermolysis of silver alkylcarboxylates with primary alkylamines was investigated as a facile synthetic method of silver nanoparticles. A series of silver alkylcarboxylates, C(7)H(15)COOAg, C(13)H(27)COOAg, and C(17)H(35)COOAg, have been prepared and the thermolysis of those silver alkylcarboxylates in the presence of various alkylamines, C(8)H(17)NH(2), C(12)H(25)NH(2), and C(18)H(37)NH(2), with no use of solvent was conducted at 120 or 180 degrees C for 5 h, providing spherical silver nanoparticles stabilized by alkylcarboxylates and alkylamines. The size and dispersibility of nanoparticles depend on the alkyl chain length of the precursors, alkylcarboxylates and alkylamines.
RESUMO
In the title compound, C15H18N2O3, the coumarin ring is essentially planar, with an r.m.s. deviation of 0.012â Å. An intra-molecular O-Hâ¯N hydrogen bond forms an S(6) ring motif. The piperazine ring adopts a chair conformation. In the crystal, a C-Hâ¯O hydrogen bond generates a C(4) chain motif running along the c axis. The chain structure is stabilized by a C-Hâ¯π inter-action. The chains are linked by π-π inter-actions [centroid-centroid distance of 3.5745â (11)â Å], forming a sheet structure parallel to the bc plane.
RESUMO
In the title compound, C22H19ClN4O, the quinolinol moiety is almost planar [r.m.s. deviation = 0.012â Å]. There is an intra-molecular O-Hâ¯N hydrogen bond involving the hy-droxy group and a pyridine N atom forming an S(9) ring motif. The dihedral angles between the planes of the quinolinol moiety and the pyridine rings are 44.15â (9) and 36.85â (9)°. In the crystal, mol-ecules are linked via C-Hâ¯O hydrogen bonds forming inversion dimers with an R 4 (4)(10) ring motif. The dimers are linked by C-Hâ¯N hydrogen bonds, forming ribbons along [01-1]. The ribbons are linked by C-Hâ¯π and π-π inter-actions [inter-centroid distance = 3.7109â (11)â Å], forming layers parallel to (01-1).
RESUMO
[reaction: see text] Photoexcitation of a zinc imidazoporphyrin-fullerene dyad with a short linkage results in formation of the charge-separated state by photoinduced electron transfer. The charge-separated state has a lifetime of 310 micros in benzonitrile at 278 K, which is the longest lifetime in solution ever reported for electron donor-acceptor-linked dyads.
RESUMO
A triarylamine-functionalized terpyridine ligand formed a highly coordinated complex with europium tris(ß-diketonate), which displayed reversible ''ON-OFF'' luminescence switching coupled with a ligand redox process of triarylamine/triarylaminium cations.