Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Thermal Decomposition of Ammonium Perchlorate containing a polymeric additive

Thermal decomposition of ammonium perchlorate (AP) containing different concentrations of a polymeric additive such as polyvinyl pyrrolidone (PVP) has been studied by the technique of differential thermal analysis (DTA). The decomposition products have been identified by means of a mass spectrometer. The results of these two experiments suggest strong interaction between AP and PVP in the solid state

Binding of Gold(III) with DNA

Metal $ions^{1..10}$ are known to bind to DNA. A number of metal ions have been studied and their binding established. $Cu(II)^{8,9,10}$ and $Ag(I)^4$ have been widely studied and ample literature exists on these two metals. On the other hand, the interaction of DNA with gold(III) (which does not occur as $Au^{3+}$ in solution, but rather exists in square planar $complexes^{11}$) has seldom been considered. During the course of our work on this phenomenon Gibson and $co-workers^{12}$ have published a paper recently reporting the results on binding of gold(III) with adenine nucleotides

Effect of Molecular Weight on the Thermal and Impact Sensitivity of Polymers in Propellants

Abstract is not available

Thermal Degradation of Polystyrene in Air

The degradation of polystyrene has been a subject of many investigations and a large volume of literature exists on the subject. More recently Cascaval et al.(1) have reported that the weight loss of polystyrene containing end groups derived from azobisisobutyronitrile (AIBN) seems to be different from that of anionically polymerized samples. We have been working for some time with polystyrene having different end groups, and in this communication we would like to report some interesting observations related to the decomposition of some of these polymers

Thermal decomposition of ethylene diamine diperchlorate

Thermal decomposition of ethylene diamine diperchlorate (EDDP) has been studied by differential-thermal analysis (DTA), thermogravimetric analysis (TGA), isothermal weight-loss measurements and mass-spectrometric analysis of the decomposition products. It has been observed that EDDP decomposes in two temperature regions. The low-temperature decomposition stops at about 35 to 40 percent weight loss below 250°C. The reason for the low-temperature cessation may be the adsorption of excess ethylene diamine on the crystal surface of EDDP. An overall activation energy of 54 kcal per mole has been calculated for the thermal decomposition of EDDP. Mass-spectrometric analysis shows that the decomposition products are mainly CO2, H2O, HCl and N2. The following stoichiometry has been proposed for the thermal decomposition of EDDP: (−CH2NH3CIO4)2→2CO2O+2HCl+N

Metal chelates in vinyl polymerization. I. Ferric dipivaloylmethide as an initiator

The behavior of the chelate, ferric dipivaloylmethide, Fe(DPM)3, in vinyl polymerization systems was investigated. The polymerization was found to be of free-radical nature. The rate of polymerization was proportional to the square root of the concentration of the chelate. The monomer exponent was close to 1.5 for the Fe(DPM)3-initiated polymerization of styrene and methyl methacrylate. The kinetic and transfer constants and activation energies for these systems have been evaluated. Spectral studies revealed the possibility of a complex formation between the chelate and the monomer. A kinetic scheme for the Fe(DPM)3-initiated polymerization is derived based on this initial complex formation