Analysis of co-aggregation of cancer based on registry data

OBJECTIVE: An exploratory analysis of co-aggregation of cancers using registry-based data. METHODS: We utilized sibships from over 18,000 families who had been recruited to the NCI-sponsored multi-institutional Cancer Genetics Network. The analysis assesses co-aggregation at the individual and family level and adjusts for ascertainment. RESULTS: We found statistically significant familial co-aggregation of lung cancer with pancreatic (adjusted p < 0.001), prostate (adjusted p < 0.003), and colorectal cancers (adjusted p = 0.004). In addition, we found significant familial co-aggregation of pancreatic and colorectal cancers (adjusted p = 0.018), and co-aggregation of hematopoietic and (non-ovarian) gynecologic cancers (adjusted p = 0.01). CONCLUSION: This analysis identified familial aggregation of cancers for which a genetic component has yet to be established.     

Magnetic properties of strongly frustrated and correlated systems

While consequences of frustration of magnetic interactions are much studied in localized spin systems, much less studies have been performed on frustrated metallic systems. However, several effects of strong geometrical frustration in metallic correlated system have also been experimentally observed in rare-earth or transition metal compounds: coexistence of magnetic and non-magnetic sites in ordered magnetic structure, heavy fermion behaviour and anomalous Hall effect due to spin chirality are consequences of frustration. An overview of the experimental observations and of the proposed models is given. Other interesting effects due to magnetic frustration in metallic systems, which have been predicted theoretically, are also reviewed.     

Using polarity for engineering oxide nanostructures: structural phase diagram in free and supported MgO(111) ultrathin films

Using an ab initio total energy approach, we study the stability of free and Ag(111)-supported MgO(111) ultrathin films. We unravel a novel microscopic mechanism of stabilization of polar oxide orientations, based on a strong modification of the MgO structural phase diagram with respect to the bulk material. We predict that, at low thickness, films which are either unsupported or deposited on Ag(111) display a graphitelike Bk structure rather than the expected rocksalt one. Our results provide a consistent interpretation of recent experimental findings, exemplify the efficiency of this novel stabilization mechanism, and suggest new methods to engineer oxide nanostructures.     

High charge-carrier mobility in pi-deficient discotic mesogens: design and structure-property relationship

Hexaazatrinaphthylene (HATNA) derivatives with six alkylsulfanyl chains of different length (hexyl, octyl, decyl and dodecyl) have been designed to obtain new potential electron-carrier materials. The electron-deficient nature of these compounds has been demonstrated by cyclic voltammetry. Their thermotropic behaviour has been studied by means of differential scanning calorimetry and polarised optical microscopy. The supramolecular organisation of these discotic molecules has been explored by temperature-dependent X-ray diffraction on powders and oriented samples. In addition to various liquid crystalline columnar phases (Col(hd), Col(rd)), an anisotropic plastic crystal phase is demonstrated to exist. The charge-carrier mobilities have been measured with the pulse-radiolysis time-resolved microwave-conductivity technique. They are found to be higher in the crystalline than in the liquid crystalline phases, with maximum values of approximately 0.9 and 0.3 cm(2) V(-1) s(-1), respectively, for the decylsulfanyl derivative. Mobilities strongly depend on the nature of the side chains.     

Deuterated analogues of the free radical trap DEPMPO: synthesis and EPR studies

Three analogues of 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO, 1) labelled with two (1-d2), five (1-d5) or seven (1-d7)2H were synthesized and used to trap the tert-butylperoxyl radical. The EPR spectra of 1-d2-OOBu(t) and 1-d7-OOBu(t) spin adducts exhibited more straightforward patterns and better signal to noise ratio than those obtained with 1 or 1-d5. The use of the easily available 1-d2 as spin trap could help significantly the analysis of the EPR signals when the signal of either superoxide or alkylperoxyl spin adduct is superimposed with the signals of other spin adducts.     

Structural Studies of Crystalline Pentacalent Organobismuth Compounds

The syntheses and X-Ray analyses of three pentavalent organobismuth compounds are described; one of these compounds has a novel diphenylbis(trifluoroacetato)-bismuthate anion with trigonal bipyramidal geometry and a stereochemically active lone pair. Analysis of these structures together with other data from the literature allows a mapping of the reaction coordinate for bismuth polyhedra.     

Variétés des courbes projectives planes de degré et lieu singulier donnés

Sans résumé