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[en] The prognostic value of p53 and p21 expression in colorectal cancer is still under debate. We hypothesize that the prognostic impact of p53 expression is dependent on p21 status. The expression of p53 and p21 was immunohistochemically investigated in a prospective cohort of 116 patients with UICC stage II and III sporadic colorectal cancer. The results were correlated with overall and recurrence-free survival. The mean observation period was 51.8 ± 2.5 months. Expression of p53 was observed in 72 tumors (63%). Overall survival was significantly better in patients with p53-positive carcinomas than in those without p53 expression (p = 0.048). No differences were found in recurrence-free survival (p = 0.161). The p53+/p21− combination was seen in 68% (n = 49), the p53+/p21+ combination in 32% (n = 23). Patients with p53+/p21− carcinomas had significantly better overall and recurrence-free survival than those with p53+/p21+ (p < 0.0001 resp. p = 0.003). Our data suggest that the prognostic impact of p53 expression on sporadic colorectal cancer is dependent on p21 status
[en] Temperature dependence of the capacity of pressed powers of a number of metal phthalocyanines has been investigated. The sharp decrease in the capacity of samples of monoclinic modification of lead phthalocyanines at 3000C is accounted by dipole's orientation polarization and respective high values of the permittivity (ε300=150 at ν=20 · 103 Hz). Alternative possible mechanisms are considered as well. 15 refs
[en] Highlights: • SrAl2O4:Dy3+ phosphors were crystallized into monoclinic structure. • Upon 350 nm excitation, the SrAl2O4:Dy3+ phosphors exhibit intense luminescence. • The dipole-dipole interaction mechanism is responsible for luminescence quenching. • The SrAl2O4:1.0 mol% Dy3+ phosphor is the best choice to design white LEDs.
[en] A refined crystal structure determination of (NH4)2 [Mo3S13]. H2O including H-atom positions of the NH4+ ions is reported. The formation of the cluster anion [Mo3S13] 2- from amorphous MoS3, suspended in O2-free aqueous ammonia solution at room temperature, is described. This observation is discussed in terms of triangular sulfide and disulfide bridged Mo3 units regarded as structural features in the amorphous educt
[en] The structure of compound has also been examined cyrstallographically. It crystallizes in the monoclinic space group P21/c with a = 7.673(1), b = 16.251(2), c = 10.874(1) Å, β = 110.42(1)°, V = 1270.7(3) Å3, Dx = 1.418 g cm−3, R1 = 0.0349 and wR2 = 0.0935 [I > 2σ(I)], respectively. The title compound has been synthesized from the reaction of isonicotinohydrazide with 2-hydroxy-3-methoxybenzaldehyde. It has been characterized by using elemental analysis, MS, IR, 1H NMR, 13C NMR and UV-Visible spectroscopic techniques.
[en] Lanthanide oxysulfides normally have the composition M202S (with M = La - Lu). The composition, M20S2, remained unknown for a long time. With Tb20S2 the first example accessible at ambient pressure has now been obtained through the oxidation of Na0.25TbClH0.75 with sulfur and apparently ubiquitous oxygen impurities as a by-product. The crystal structure is built up from 02- centered [Tb3+]4 tetrahedra that are connected through a common edge to form dimers [Tb602]14+. A more convenient route to Tb20S2 is the crystallization from a NaCl melt starting with appropriate mixtures of Tb203 and Tb2S3
[en] AsS2 single crystals have been obtained for the first time from an As2S3 melt at pressures above 6 GPa and temperatures above 800 K in the As2S3 → AsS + AsS2 reaction. The monoclinic structure of the new high-pressure phase is solved by X-ray diffraction analysis and compared to the structure of high-pressure AsS phase, which was studied previously.
[en] The issues of the composition-structure relationship of boron carbide are discussed. A new hypothesis based on the presence of channels with a diameter of 2.7–2.9 Å in crystals, into which C or B atoms can be intruded, has been proposed. The intrusion has been confirmed by the data of quantum-chemical simulation using VASP program. It has been shown that the introduction of atoms into the channels changes the cell parameters and deforms the structural fragments. The latter may cause the formation of monoclinic crystals of boron carbide. According to the quantum chemical simulattions, the cell parameters of boron carbide crystals of the same composition depend on the site of intrusion of the C atoms into the channels.
[en] Differentiation of myocytes is impaired in patients with myotonic dystrophy type 1, DM1. CUG repeat binding protein, CUGBP1, is a key regulator of translation of proteins that are involved in muscle development and differentiation. In this paper, we present evidence that RNA-binding activity of CUGBP1 and its interactions with initiation translation complex eIF2 are differentially regulated during myogenesis by specific phosphorylation and that this regulation is altered in DM1. In normal myoblasts, Akt kinase phosphorylates CUGBP1 at Ser28 and increases interactions of CUGBP1 with cyclin D1 mRNA. During differentiation, CUGBP1 is phosphorylated by cyclinD3-cdk4/6 at Ser302, which increases CUGBP1 binding with p21 and C/EBPβ mRNAs. While cyclin D3 and cdk4 are elevated in normal myotubes; DM1 differentiating cells do not increase these proteins. In normal myotubes, CUGBP1 interacts with cyclin D3/cdk4/6 and eIF2; however, interactions of CUGBP1 with eIF2 are reduced in DM1 differentiating cells and correlate with impaired muscle differentiation in DM1. Ectopic expression of cyclin D3 in DM1 cells increases the CUGBP1-eIF2 complex, corrects expression of differentiation markers, myogenin and desmin, and enhances fusion of DM1 myoblasts. Thus, normalization of cyclin D3 might be a therapeutic approach to correct differentiation of skeletal muscle in DM1 patients