158 research outputs found
DNA Interactions with Ruthenium(ll) Polypyridine Complexes Containing Asymmetric Ligands
In an attempt to probe nucleic acid structures, numerous Ru(II) complexes with different ligands have been synthesized and investigated. In this contribution we focus on the DNA-binding properties of
ruthenium(II) complexes containing asymmetric ligands that have attracted little attention in the past decades.
The influences of the shape and size of the ligand on the binding modes, affinity, enantioselectivities and photocleavage of the complexes to DNA are described
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Global quark spin correlations in relativistic heavy ion collisions
The observation of the vector meson's global spin alignment by the STAR Collaboration reveals that strong spin correlations may exist for quarks and antiquarks in relativistic heavy-ion collisions in the normal direction of the reaction plane. We propose a systematic method to describe such correlations in the quark matter. We classify them as local and long range quark spin correlations in the system. We show in particular that the effective quark spin correlations contain the genuine spin correlations originated directly from the dynamical process as well as those induced by averaging over other degrees of freedom. We also show that such correlations can be studied by measuring the vector meson's spin density matrix and hyperon-hyperon and hyperon-anti-hyperon spin correlations. We present the relationships between these measurable quantities and spin correlations of quarks and antiquarks
1,2-Bis[aminoÂ(pyrimidin-2-yl)methylÂene]hydrazine dihydrate
The centrosymmetric organic molecule in the title compound, C10H10N8·2H2O, is essentially flat and has a trans configuration. The molÂecules are linked by interÂmolecular OâHâŻN, NâHâŻO and NâHâŻN hydrogen bonds to form a linear chain structure
Synthesis, Characterization and Antitumor Activity of a Series of Polypyridyl Complexes
A series of polypyridyl complexes have been synthesized. All polypyridyl complexes and some of the soluble ligands have been assayed for antitumor activity in vitro against the HL-60 (the human leucocytoma) cells, BEL-7402 (the human liver carcinoma) cells, KB (the human nasopharyngeal carcinoma) cells and HELA (the human adenocarcinoma of cervix) cells. The results indicate that several complexes have relative activity against different cell lines. Especially, the complexes [Co(bpy)2(pip)]3+, [Co(phen)2(pip)]3+, [Ru(bpy)2(pztp)]2+ and [Ru(pztp)2(bpy)]2+ show relative high activity against four tumor cell lines. Moreover, they are slightly more effective than cisplatin. At the concentration of 100 ÎŒg/mL, the complexes show inhibitory rate of 72âŒ86% for the cancer cells and have no toxicity for MDCK and Vero cells. It is indicated that these complexes can inhibit cancer cells selectively
Multiple parton scattering in nuclei: gauge invariance
Within the framework of a generalized collinear factorization for multiple
parton scattering in nuclear medium, twist-4 contributions to DIS off a large
nucleus can be factorized as a convolution of hard parts and two-parton
correlation functions. The hard parts for the quark scattering in the
light-cone gauge correspond to interaction with a transverse (physical) gluon
in the target, while they are given by the second derivative of the cross
section with a longitudinal gluon in the covariant gauge. We provide a general
proof of the equivalence of the hard parts in the light-cone and covariant
gauge. We further demonstrate the equivalence in calculations of twist-4
contributions to semi-inclusive cross section of DIS in both lowest order and
next leading order. Calculations of the nuclear transverse momentum broadening
of the struck quark in the light-cone and covariant gauge are also discussed.Comment: 23 pages with 4 figure
SIRT1 deacetylates SATB1 to facilitate MARHS2-MARΔ interaction and promote Δ-globin expression
The higher order chromatin structure has recently been revealed as a critical new layer of gene transcriptional control. Changes in higher order chromatin structures were shown to correlate with the availability of transcriptional factors and/or MAR (matrix attachment region) binding proteins, which tether genomic DNA to the nuclear matrix. How posttranslational modification to these protein organizers may affect higher order chromatin structure still pending experimental investigation. The type III histone deacetylase silent mating type information regulator 2, S. cerevisiae, homolog 1 (SIRT1) participates in many physiological processes through targeting both histone and transcriptional factors. We show that MAR binding protein SATB1, which mediates chromatin looping in cytokine, MHC-I and ÎČ-globin gene loci, as a new type of SIRT1 substrate. SIRT1 expression increased accompanying erythroid differentiation and the strengthening of ÎČ-globin cluster higher order chromatin structure, while knockdown of SIRT1 in erythroid k562 cells weakened the long-range interaction between two SATB1 binding sites in the ÎČ-globin locus, MARHS2 and MARΔ. We also show that SIRT1 activity significantly affects Δ-globin gene expression in a SATB1-dependent manner and that knockdown of SIRT1 largely blocks Δ-globin gene activation during erythroid differentiation. Our work proposes that SIRT1 orchestrates changes in higher order chromatin structure during erythropoiesis, and reveals the dynamic higher order chromatin structure regulation at posttranslational modification level
l-Tetrahydropalmatine, an Active Component of Corydalis yanhusuo W.T. Wang, Protects against Myocardial Ischaemia-Reperfusion Injury in Rats
l-Tetrahydropalmatine (l-THP) is an active ingredients of Corydalis yanhusuo W.T. Wang, which protects against acute global cerebral ischaemia-reperfusion injury. In this study, we show that l-THP is cardioprotective in myocardial ischaemia-reperfusion injury and examined the mechanism. Rats were treated with l-THP (0, 10, 20, 40 mg/kg b.w.) for 20 min before occlusion of the left anterior descending coronary artery and subjected to myocardial ischaemia-reperfusion (30 min/6 h). Compared with vehicle-treated animals, the infarct area/risk area (IA/RA) of l-THP (20, 40 mg/kg b.w.) treated rats was reduced, whilst l-THP (10 mg/kg b.w.) had no significant effect. Cardiac function was improved in l-THP-treated rats whilst plasma creatine kinase activity declined. Following treatment with l-THP (20 mg/kg b.w.), subunit of phosphatidylinositol 3-kinase p85, serine473 phosphorylation of Akt and serine1177 phosphorylation of endothelial NO synthase (eNOS) increased in myocardium, whilst expression of inducible NO synthase (iNOS) decreased. However, the expression of HIF-1α and VEGF were increased in I30 minR6 h, but decreased to normal level in I30 minR24 h, while treatment with l-THP (20 mg/kg b.w.) enhanced the levels of these two genes in I30 minR24 h. Production of NO in myocardium and plasma, activity of myeloperoxidase (MPO) in plasma and the expression of tumour necrosis factor-α (TNF-α) in myocardium were decreased by l-THP. TUNEL assay revealed that l-THP (20 mg/kg b.w.) reduced apoptosis in myocardium. Thus, we show that l-THP activates the PI3K/Akt/eNOS/NO pathway and increases expression of HIF-1α and VEGF, whilst depressing iNOS-derived NO production in myocardium. This effect may decrease the accumulation of inflammatory factors, including TNF-α and MPO, and lessen the extent of apoptosis, therefore contributing to the cardioprotective effects of l-THP in myocardial ischaemia-reperfusion injury
Evasion of anti-growth signaling: a key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds
The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and KrĂŒppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally-occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally-occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting
Risk to human health related to the presence of perfluoroalkyl substances in food
Acknowledgements: The Panel wishes to thank the following for their support provided to this scientific output as Hearing experts: Klaus Abraham, Esben Budtz-JĂžrgensen, Tony Fletcher, Philippe Grandjean, Hans Mielke and Hans Rumke and EFSA staff members: Davide Arcella, Marco Binaglia, Petra Gergelova, Elena Rovesti and Marijke Schutte. The Panel wishes to acknowledge all European competent institutions, Member State bodies and other organisations that provided data for this scientific output. The Panel would also like to thank the following authors and co-authors for providing additional information in relation to their respective studies: Berit Granum, Margie M Peden-Adams, Thomas Webster.Peer reviewedPublisher PD
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