27 research outputs found
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
Differential transcriptomic profiles effected by oil palm phenolics indicate novel health outcomes
Abstract Background Plant phenolics are important nutritional antioxidants which could aid in overcoming chronic diseases such as cardiovascular disease and cancer, two leading causes of death in the world. The oil palm (Elaeis guineensis) is a rich source of water-soluble phenolics which have high antioxidant activities. This study aimed to identify the in vivo effects and molecular mechanisms involved in the biological activities of oil palm phenolics (OPP) during healthy states via microarray gene expression profiling, using mice supplemented with a normal diet as biological models. Results Having confirmed via histology, haematology and clinical biochemistry analyses that OPP is not toxic to mice, we further explored the gene expression changes caused by OPP through statistical and functional analyses using Illumina microarrays. OPP showed numerous biological activities in three major organs of mice, the liver, spleen and heart. In livers of mice given OPP, four lipid catabolism genes were up-regulated while five cholesterol biosynthesis genes were down-regulated, suggesting that OPP may play a role in reducing cardiovascular disease. OPP also up-regulated eighteen blood coagulation genes in spleens of mice. OPP elicited gene expression changes similar to the effects of caloric restriction in the hearts of mice supplemented with OPP. Microarray gene expression fold changes for six target genes in the three major organs tested were validated with real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and the correlation of fold changes obtained with these two techniques was high (R2 = 0.9653). Conclusions OPP showed non-toxicity and various pleiotropic effects in mice. This study implies the potential application of OPP as a valuable source of wellness nutraceuticals, and further suggests the molecular mechanisms as to how dietary phenolics work in vivo.</p
Novel Common Genetic Susceptibility Loci for Colorectal Cancer
BACKGROUND: Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10-8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. METHODS: We conducted a GWAS in European descent CRC cases and control subjects using a discovery-replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10-8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. RESULTS: The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10-8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. CONCLUSIONS: This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screenin
Survival of patients with salivary gland malignancies depending on the molecular profile of the tumor
Introduction. Standard methods of drug or radiation therapy administration for salivary gland cancer is the least successful for now. Therefore, the identification of new markers with morphological features is extremely necessary to improve the effectiveness of treatment and increase the survival rates of patients with this pathology.The study objective is to assess the prevalence of expression of HER2/neu, PD-L1, and RET mRNA in salivary gland malignancies and assess their impact on overall and disease-free survival.Materials and methods. Fifty-nine patients with a confirmed diagnosis of salivary gland cancer (stages II–IVA) were examined in the period from 2012 to 2014 at Saint Petersburg City Clinical Oncology Dispensary. All materials were subjected to immunohistochemical research to determine the expression of HER2, PD-L1 in tumor and immune cells, the CPS index was calculated, and the frequency of the mRNA gene RET expression using a real-time polymerase chain reaction was detected.Results. The overall survival of patients with mild and high HER2 expression was 41 months (95 % confidence interval (CI) 4.50–72.00), which is more than 4 time less than in patients with low or no expression (p = 0.00715). Significant differences were also received in the progression-free survival in the group of patients with negative or insignificant expression of HER2 receptors. The overall survival of patients with CPS >1 was 72 months (95 % CI 19.5–72.00) and significantly differed from the group of patients with CPS <1, where it was not yet achieved (p = 0.0124). mRNA expression of the RET gene was detected in 13 out of 48 cases, which was 27.08 %. The expression level ranged from 0 to 0.205. The progression-free survival in the group of patients with mRNA expression was 168 months (95 % CI 16.00–168.00) and tended to increase in the group of patients who did not have this expression.Conclusion. When analyzing the obtained data, it was proved that knowledge of the salivary glands malignant tumors receptor status become one of the factors in determining the prognosis of the disease, as well as a predictive factor of targeted drugs effectiveness (after сonducting prospective randomized studies)
Electrical characterization of true Silicon-On-Nothing MOSFETs fabricated by Si layer transfer over a pre-etched cavity
In this paper, "true" Silicon-On-Nothing (SON) MOSFETs fabricated by a new technique, consisting in Si layer transfer over a preetched cavity, are investigated. The process has no potential limitation with regards to the device dimensions as well as to the thicknesses of Si film and so-called "nothing" layers. Comparing to single-gate (SG) fully-depleted (FD) SOI MOSFETs fabricated on the same wafer, improved electrical characteristics of SON MOSFETs are demonstrated. Self-heating effect, which can be considered as the main drawback of SON devices, is experimentally addressed for the first time. Finally, the source-to-drain coupling through the substrate is demonstrated to be practically suppressed in such device architecture. (c) 2007 Elsevier Ltd. All rights reserved