2,563 research outputs found
2,2′-(p-Phenylenedithio)diacetic acid
The complete molecule of the title compound, C10H10O4S2, is generated by a crystallographic inversion centre. In the crystal, molecules are linked into a one-dimensional chain by intermolecular O—H⋯O hydrogen bonds
A closer look at interacting dark energy with statefinder hierarchy and growth rate of structure
We investigate the interacting dark energy models by using the diagnostics of
statefinder hierarchy and growth rate of structure. We wish to explore the
deviations from CDM and to differentiate possible degeneracies in the
interacting dark energy models with the geometrical and structure growth
diagnostics. We consider two interacting forms for the models, i.e., and , with being the dimensionless
coupling parameter. Our focus is the ICDM model that is a
one-parameter extension to CDM by considering a direct coupling
between the vacuum energy () and cold dark matter (CDM), with the only
additional parameter . But we begin with a more general case by
considering the ICDM model in which dark energy has a constant
(equation-of-state parameter). For calculating the growth rate of structure, we
employ the "parametrized post-Friedmann" theoretical framework for interacting
dark energy to numerically obtain the values for the models. We
show that in both geometrical and structural diagnostics the impact of is
much stronger than that of in the ICDM model. We thus wish to have a
closer look at the ICDM model by combining the geometrical and
structural diagnostics. We find that the evolutionary trajectories in the
-- plane exhibit distinctive features and the departures
from CDM could be well evaluated, theoretically, indicating that the
composite null diagnostic is a promising tool for
investigating the interacting dark energy models.Comment: 17 pages, 4 figures; accepted for publication in JCA
Aquachlorido{1-[1-(4-hydroxyphenyl)-1H-tetrazol-5-ylsulfanyl]acetato}(methanol)(1,10-phenanthroline)manganese(II)
The title complex, [Mn(C9H7N4O3S)Cl(C12H8N2)(CH4O)(H2O)], contains an MnII ion six-coordinated by one O atom from the 2-[1-(4-hydroxyphenyl)-1H-tetrazol-5-ylsulfanyl]acetate ligand, two N atoms from a chelating 1,10-phenanthroline ligand, one O atom from a methanol molecule, one Cl atom and one water molecule in a distorted octahedral coordination geometry. The existence of O—H⋯Cl, O—H⋯N and O—H⋯O hydrogen bonds further produces a two-dimensional structure
Poly[[(2,2′-bipyridine)(μ 3-7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylato)cadmium] monohydrate]
The title compound, {[Cd(C8H8O5)(C10H8N2)]·H2O}n, was obtained by the reaction of cadmium acetate with 2,2′-bipyridine and 7-oxabicyclo(2.2.1)heptane-2,3-dicarboxylic anhydride. The CdII atom is seven-coordinated in a distorted pentagonal–bipyramidal configuration, defined by five O atoms from the carboxylate groups of three 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylato ligands and two N atoms from the 2,2′-bipyridine ligand. Two O atoms link two CdII atoms, forming a dinuclear center: the Cd—O—Cd bridging angle is 110.19 (6)°. The polymeric structure extends along [100] and is linked by intermolecular O—H⋯O hydrogen bonds involving the solvent water molecule. Extensive π–π stacking exists between 2,2-bypiridine ligands along [010] with centroid-centroid distance of 3.650 (2)
(Z)-1,3-Bis(4-chlorophenyl)-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-one
In the title molecule, C17H11Cl2N3O, the C=C bond connecting the triazole and 4-chlorophenyl groups adopts a Z geometry. The dihedral angles formed by the triazole ring and the 4-chloro substituted benzene rings are 67.3 (1) and 59.1 (1)°. The dihedral angle between the two benzene rings is 73.5 (1)°
Bis{1-[4-(benzyloxy)phenyl]-4,4,4-trifluorobutane-1,3-dionato(1−)}dipyridinecobalt(II)
In the title compound, [Co(C17H12F3O3)2(C5H5N)2], the CoII ion is situated on a twofold rotation axis, coordinated by four O atoms from two 1-[4-(benzyloxy)phenyl]-4,4,4-trifluorobutane-1,3-dionate(1−) (L) ligands and two N atoms from two pyridine ligands in a distorted octahedral geometry. The two pyridine rings form a dihedral angle of 84.63 (7)°. The two benzene rings in L are twisted at 58.83 (5)°. Weak intermolecular C—H⋯F hydrogen bonds consolidate the crystal packing
Atherosclerosis and Helminths Infection
Atherosclerosis is a chronic disease that causes various cardiovascular complications. Plaque formation in atherosclerosis is considered similar to the pathogenesis of other autoimmune diseases; thus, immunomodulation and immunosuppression may present strategies for the treatment and prevention of these diseases. Interestingly helminth infection was found to inhibit T helper 1-mediated autoimmune diseases and T helper 2-mediated allergy and asthma, indicating significant potential for clinical application. Some study even found that therapeutic efficacy of the viable tapeworm was superior to dexamethasone treatment. Recently, some studies have shown an inverse association between helminth infections and inflammatory diseases, including diabetes mellitus, lipid abnormality, and atherosclerosis. Will the underlying mechanism bring us a new idea on the treatment for these diseases? We tried to find an answer by reviewing recent articles
Effects of polymer molecular weight on relative oral bioavailability of curcumin
Yin-Meng Tsai,1 Wan-Ling Chang-Liao,1 Chao-Feng Chien,1 Lie-Chwen Lin,1,2 Tung-Hu Tsai,1,31Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, 2National Research Institute of Chinese Medicine, 3Department of Education and Research, Taipei City Hospital, Taipei, TaiwanBackground: Polylactic-co-glycolic acid (PLGA) nanoparticles have been used to increase the relative oral bioavailability of hydrophobic compounds and polyphenols in recent years, but the effects of the molecular weight of PLGA on bioavailability are still unknown. This study investigated the influence of polymer molecular weight on the relative oral bioavailability of curcumin, and explored the possible mechanism accounting for the outcome.Methods: Curcumin encapsulated in low (5000–15,000) and high (40,000–75,000) molecular weight PLGA (LMw-NPC and HMw-NPC, respectively) were prepared using an emulsification-solvent evaporation method. Curcumin alone and in the nanoformulations was administered orally to freely mobile rats, and blood samples were collected to evaluate the bioavailability of curcumin, LMw-NPC, and HMw-NPC. An ex vivo experimental gut absorption model was used to investigate the effects of different molecular weights of PLGA formulation on absorption of curcumin. High-performance liquid chromatography with diode array detection was used for quantification of curcumin in biosamples.Results: There were no significant differences in particle properties between LMw-NPC and HMw-NPC, but the relative bioavailability of HMw-NPC was 1.67-fold and 40-fold higher than that of LMw-NPC and conventional curcumin, respectively. In addition, the mean peak concentration (Cmax) of conventional curcumin, LMw-NPC, and HMw-NPC was 0.028, 0.042, and 0.057 µg/mL, respectively. The gut absorption study further revealed that the HMw-PLGA formulation markedly increased the absorption rate of curcumin in the duodenum and resulted in excellent bioavailability compared with conventional curcumin and LMw-NPC.Conclusion: Our findings demonstrate that different molecular weights of PLGA have varying bioavailability, contributing to changes in the absorption rate at the duodenum. The results of this study provide the rationale for design of a nanomedicine delivery system to enhance the bioavailability of water-insoluble pharmaceutical compounds and functional foods.Keywords: absorption, duodenum, molecular weight, poly(lactic-co-glycolic acid), PLGA, relative oral bioavailabilit
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