4,915 research outputs found
Molecular Basis of Inhibitory Activities of Berberine against Pathogenic Enzymes in Alzheimer's Disease
The natural isoquinoline alkaloid berberine possesses potential to treat Alzheimer's disease (AD) by targeting multiple pathogenic factors. In the present study, docking simulations were performed to gain deeper insights into the molecular basis of berberine's inhibitory effects against the important pathogenic enzymes of AD, that is, acetylcholinesterase, butyrylcholinesterase, and two isoforms of monoamine oxidase. It was found that the theoretical binding affinities of berberine to the four enzymes are very close to the experimental values, which verify the methodology. Further inspection to the binding modes found that hydrophobic interactions between the hydrophobic surface of berberine and neighboring hydrophobic residues are the principal forces contributing to the ligand-receptor interactions. Although berberine cation also has potential to form electrostatic interaction with neighboring residues, it is interesting to find that electrostatic force is excluded in the four cases unexpectedly. These results have important implications for the berberine-based anti-AD drug design
Alzheimer's Disease and Risk of Hip Fracture: A Meta-Analysis Study
Background. Alzheimer's disease (AD) is the most common cause of dementia in the elderly population. Growing evidence supports that AD patients are at high risk for hip fracture, but the issue remains questionable. The purpose of the present study is to perform a meta-analysis to explore the association between AD and risk of hip fracture. Considering that bone mineral density (BMD) acts as a strong predictor of bone fracture, we also studied the hip BMD in AD patients. Methods. We searched all publications in Medline, SciVerse Scopus, and Cochrane Library published up to January 2012 about the association between AD and hip fracture or hip BMD. Results. There are 9 studies included in the meta-analysis. The results indicate that AD patients are at higher risk for hip fracture (OR and 95% CI fixed: ES = 2.58, 95% CI = [2.03, 3.14]; dichotomous data: summary OR = 1.80, 95% CI = [1.54, 2.11]) than healthy controls. Further meta-analysis showed that AD patients have a lower hip BMD (summary SMD = −1.12, 95% CI = [−1.34, −0.90]) than healthy controls. Conclusions. It was found that in comparison with healthy controls AD patients are at higher risk for hip fracture and have lower hip BMD
4,4′-Bipyridinium bis(oxalato-κ2 O 1,O 2)cuprate(II): an ion-pair complex
The title compound, (C10H10N2)[Cu(C2O4)2] or (4,4′-H2bpy)[Cu(ox)2] (bpy is 4,4′-bipyridine and ox is oxalate), is an ion-pair complex comprising a protonated 4,4′-bipyridinium dication and a square-planar dioxalatocopper(II) dianion. In the centrosymmetric dianion, the CuII centre is coordinated by four O atoms from the two dicrete oxalate ligands [Cu—O = 1.9245 (19) and 1.9252 (17) Å], while the planar dications are also centrosymmetric. Inter-species N—H⋯O hydrogen bonds link the cations and anions into one-dimensional chains and, together with weak intra-ion C—H⋯O interactions, give a two-dimensional sheet structure
Bis(2-amino-4-methyl-1,3-thiazole-κN 3)dichloridocadmium(II)
In the title compound, [CdCl2(C4H6N2S)2], the CdII atom is coordinated by two chlorido ligands and two N atoms of the 2-amino-5-methyl-1,3-thiazole (amtz) ligands in a slightly distorted tetrahedral coordination geometry. Intra- and intermolecular N—H⋯Cl hydrogen bonding stabilizes the crystal structure. A weak S⋯Cl interaction [3.533 (2) Å] is observed between neighboring molecules
Nucleon pole contributions in , , and decays
Nucleon pole contributions in , , and decays are re-studied. Different
contributions due to PS-PS and PS-PV couplings in the -N interaction and
the effects of form factors are investigated in the decay channel. It is found that when the ratio of takes
small value, without considering the form factor, the difference
between PS-PS and PS-PV couplings are negligible. However, when the
form factor is included, this difference is greatly enlarged. The resultant
decay widths are sensitive to the form factors. As a conclusion, the
nucleon-pole contribution as a background is important in the decay and must be accounted. In the and
decays, its contribution is less than 0.1% of the data. In the
decay, it provides rather important contribution
without considering form factors. But the contribution is suppressed greatly
when adding the off-shell form factors. Comparing these results with data would
help us to select a proper form factor for such kind of decay.Comment: 29 pages, 13 figure
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