Kualitas Semen Kambing Sapera yang Dibekukan dalam Pengencer Tris Kuning Telur dengan Imbuhan Pentoxifylline (QUALITY OF SAPERA BUCK SEMEN FROZEN IN TRIS EGG YOLK EXTENDER ADDED WITH PENTOXIFYLLINE)

The aim of this study was to determine the effective dose of pentoxyfilline (PTX) to improve the quality of sapera buck frozen semen in Tris Egg Yolk (TEY) extender. Two sexually mature sapera bucks aged 1.5 years old was used as semen source. Semen collected with artificial vagina. Fresh semen were evaluated macro and microscopically. Only ejaculates showing > 70% sperm motility were selected. Semen were divided into four aliquots tubes containing TEY extender with 0 mM, 3.5 mM, 5 mM and 6.5 mM PTX each tube. After dilution, semen were packed into mini straw (0.25 ml) and equilibrated at 5 oC for 4 hours, then frozen above liquid nitrogen vapors for 10 minutes before plunged into liquid nitrogen (-196 oC). Results of this study showed that 6.5 mM PTX addition to the TEY extender improve post-thaw semen motility (P<0.05) but not viability and plasma membrane integrity. It concluded that 6.5 mM PTX addition to TEY extender improved post-thaw sperm motility of sapera buck

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

Size dependence of biexciton binding energy in single InAs/GaAs quantum dots

This paper studies the size dependence of biexciton binding energy in single quantum dots (QDs) by using atomic force microscopy and micro-photoluminescence measurements. It finds that the biexciton binding energies in the QDs show "binding" and "antibinding" properties which correspond to the large and small sizes of QDs, respectively. The experimental results can be well interpreted by the biexciton potential curve, calculated from the exciton molecular model and the Heitler-London method