Perchloratobis[1-(1,10-phenanthrolin-2-yl)-2-pyridone]zinc(II) perchlorate

In the title mononuclear complex, [Zn(ClO4)(C17H11N3O)2]ClO4, the ZnII ion is coordinated in a distorted octa­hedral geometry. The dihedral angles between the pyridine rings and the mean planes of the 1,10-phenanthroline ring system in each of the 1-(1,10-phenanthrolin-2-yl)-2-pyridone (PP) ligands is 24.51 (10)° for the tridendate PP ligand and 73.55 (6)° for the bidentate PP ligand. Within the mol­ecule there is a weak π–π inter­action between the pyridine ring of the bidentate ligand and the 1,10-phenanthroline ring system of the tridendate ligand with a centroid–centroid distance of 3.6383 (19) Å

Diaqua­(1,10-phenanthrolin-2-ol)nickel(II) dinitrate

In the mononuclear title complex, [Ni(C12H8N2O)2(H2O)2](NO3)2, the NiII ion is coordinated in a distorted octa­hedral geometry. The dihedral angle between the two mean planes defined by the phenanthroline ligands is 88.26 (6)°. Intra- and intermolecular O—H⋯O hydrogen bonds between the cation and the anions lead to the formation of a layered arrangement parallel to (010)

Spin Correlations in top quark pair production near threshold at the e−e+ e^- e^+ Linear Collider

We investigate the spin correlations in top quark pair production near threshold at the $e^- e^+$ linear collider. Comparing with the results above the threshold region, we find that near the threshold region the off-diagonal basis, the optimized decomposition of the top quark spins above the threshold region, does not exist, and the beamline basis is the optimal basis, in which there are the dominant spin components: the up-down (UD) component for $e_L^- e^+$ scattering and the down-up (DU) component for $e_R^- e^+$ scattering can make up more than 50% of the total cross section, respectively.Comment: 12 pages, 3 figures, minor modification

Robust Training under Label Noise by Over-parameterization

Recently, over-parameterized deep networks, with increasingly more network parameters than training samples, have dominated the performances of modern machine learning. However, when the training data is corrupted, it has been well-known that over-parameterized networks tend to overfit and do not generalize. In this work, we propose a principled approach for robust training of over-parameterized deep networks in classification tasks where a proportion of training labels are corrupted. The main idea is yet very simple: label noise is sparse and incoherent with the network learned from clean data, so we model the noise and learn to separate it from the data. Specifically, we model the label noise via another sparse over-parameterization term, and exploit implicit algorithmic regularizations to recover and separate the underlying corruptions. Remarkably, when trained using such a simple method in practice, we demonstrate state-of-the-art test accuracy against label noise on a variety of real datasets. Furthermore, our experimental results are corroborated by theory on simplified linear models, showing that exact separation between sparse noise and low-rank data can be achieved under incoherent conditions. The work opens many interesting directions for improving over-parameterized models by using sparse over-parameterization and implicit regularization.Comment: 25 pages, 4 figures and 6 tables. Code is available at https://github.com/shengliu66/SO

Mees Line of Nails, Osler Nodes, Janeway Lesions as evidence of disseminated intravascular coagulation

Podeu consultar la versió en català a: http://hdl.handle.net/11703/8944

Systematic review on the treatment of pentoxifylline in patients with non-alcoholic fatty liver disease

<p>Abstract</p> <p>Background</p> <p>As an anti-TNF agent that targets inflammatory process directly, Pentoxifylline has been investigated for treatment of NASH in individual studies and pilot trials for years. We summarized the available information and generating hypotheses for future research.</p> <p>Data Sources</p> <p>Google, Cochrane, MEDLINE, and EMBASE and the <it>Chinese Biomedical </it>data bases for studies restricted to pentoxifylline treatment in humans with NAFLD in all languages until June 2010. Six studies (2 randomized, double-blind, placebo-controlled trials; 4 prospective cohort studies) extracted from 11604 references.</p> <p>Results</p> <p>Pentoxifylline-treated patients showed a significant decrease AST (n = 37, <it>P </it>= 0.01) and ALT (n = 50, <it>P </it>= 0.03), but no significant effect on IL-6 (n = 36, <it>P </it>= 0.33) and TNF-α (n = 68, <it>P </it>= 0.26) compared with Placebo or UDCA-controlled groups. Improvement in one or more histological variables was reported in two trails, only 1 study showed a reduction in of one or two points in fibrosis stage.</p> <p>Limitations</p> <p>The trails did not consistently report all of the outcomes of interest. Sample sizes (117 patients totally) were small and only 2 out of 6 studies had a randomized, controlled design.</p> <p>Conclusion</p> <p>Pentoxifylline reduce AST and ALT levels and may improve liver histological scores in patients with NALFD/NASH, but did not appear to affect cytokines. Large, prospective, and well-designed randomized, controlled studies are needed to address this issue. Novel therapeutic targets for activation of inflammatory signaling pathways by fat also merit investigation.</p

(22E,24R)-5α-Ergosta-2,22-dien-6-one

In the title mol­ecule, C28H44O, two six-membered rings have regular chair conformations, while the six-membered ring containing the C=C double bond exhibits a distorted chair conformation. The five-membered ring adopts an envelope conformation. In the crystal, weak inter­molecular C—H⋯O inter­actions link mol­ecules into chains along the b axis. The absolute configuration was assigned to correspond with that of the known chiral centres in a precursor mol­ecule

(22E,24R)-3α,5-Cyclo-5α-ergosta-22-en-6-one

In the title mol­ecule, C28H44O, the two six-membered rings have a chair conformation and the two five-membered rings haveenvelope conformations. The crystal packing exhibits no short inter­molecular contacts. The absolute configuration was assigned to correspond with that of the known chiral centres in a precursor molecule, which remained unchanged during the synthesis of the title compound

The normal-auxeticity mechanical phase transition in graphene

When a solid object is stretched, in general, it shrinks transversely. However, the abnormal ones are auxetic, which exhibit lateral expansion, or negative Poisson ratio. While graphene is a paradigm 2D material, surprisingly, graphene converts from normal to auxetic at certain strains. Here, we show via molecular dynamics simulations that the normal-auxeticity mechanical phase transition only occurs in uniaxial tension along the armchair direction or the nearest neighbor direction. Such a characteristic persists at temperatures up to 2400 K. Besides monolayer, bilayer and multi-layer graphene also possess such a normal-auxeticity transition. This unique property could extend the applications of graphene to new horizons