33 research outputs found
Penta-Band Dielectric Loaded Folded Loop Antenna for Mobile Handset
A compact internal penta-band folded loop antenna for LTE1600/2600/WIMAX3. 5/WLAN2. 4/5.2 multiple mobile operations is proposed and investigated. The whole antenna structure is formed of a single folded meander loop pattern mount on the surfaces of a dielectric carrier with L-shape have a volume of 20 mm× 17mm× 5 mm, and ground plane of length 110mm is used. The size of the total structure is 110× 50× 5mm3. The compact structure makes it very suitable for today’s mobile phones applications. With 6 dB return loss, five operating frequency bands covering LTE/WLAN/WiMAX MHz can be achieved with our design. Also, the resonant characteristics of the antenna can be tuned by using various strip dimensions and also the dielectric material of the carrier. Moreover, simulated results exhibit that the proposed folded loop antenna features nearly good omnidirectional radiation patterns with proper gain. The design and optimizing of the performance of the proposed antenna are performed by using a high frequency structure simulator HFSS. Details of the various antenna parameters are presented and discussed in this paper
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Understanding the Effect of Introducing Micro- and Nanoparticle Bismuth Oxide (Bi2O3) on the Gamma Ray Shielding Performance of Novel Concrete
The aim of this study is to investigate the radiation shielding properties of novel concrete samples with bulk Bi2O3 and Bi2O3 nanoparticles (Bi2O3 NP) incorporated into its composition. The mass attenuation coefficient of the concrete samples without Bi2O3 and with 5 and 7 wt% bulk Bi2O3 were experimentally determined and were compared against values obtained using the XCOM and Geant4 simulations. Both methods greatly agree with the experimental values. The linear attenuation coefficients (LAC) of blank concrete (C-0), concrete with 5% bulk Bi2O3 (C-B5), and concrete with 5% nanoparticle Bi2O3 (C-N5) were determined and compared at a wide energy range. We found that the LAC follows the trend of C-0 < C-B5 < C-N5 at all the tested energies. Since both C-B5 and C-N5 have a greater LAC than C-0, these results indicate that the addition of Bi2O3 improves the shielding ability of the concretes. In addition, we investigated the influence of nanoparticle Bi2O3 on the LAC of the concretes. The half-value layer (HVL) for the concretes with bulk Bi2O3 and Bi2O3 nanoparticles is also investigated. At all energies, the C-0 has the greatest HVL, while C-N15 has the least. Thus, C-N15 concrete is the most space efficient, while C-0 is the least space efficient. The radiation protection efficiency (RPE) of the prepared concretes was found to decrease with increasing energy for all five samples. For C-0, the RPE decreased from 63.3% at 0.060 MeV to 13.48% at 1.408 MeV, while for C-N15, the RPE decreased from 87.9 to 15.09% for the same respective energies. Additionally, C-N5 had a greater RPE than C-B5, this result demonstrates that Bi2O3 NP are more efficient at shielding radiation than bulk Bi2O3
Utilization of Waste Marble and Bi<sub>2</sub>O<sub>3</sub>-NPs as a Sustainable Replacement for Lead Materials for Radiation Shielding Applications
In an attempt to reutilize marble waste, a new approach is presented in the current study to promote its use in the field of shielding against ionizing radiation. In this study, we aimed to develop a novel and sustainable/eco-friendly lead-free radiation shielding material by improving artificial marble (AM) produced from marble waste combined with polyester by reinforcing it with bismuth oxide (Bi2O3) nanoparticles. Six samples of AM samples doped with different concentrations (0%, 5%, 10%, 15%, 20%, and 25%) of Bi2O3 nanoparticles were prepared. The linear attenuation coefficient (LAC) values were measured experimentally through the narrow beam method at different energies (0.0595 MeV, 0.6617 MeV, 1.1730 MeV, and 1.330 MeV) for all samples with various concentrations of Bi2O3. Radiological shielding parameters such as half value layer (HVL), tenth-value layer (TVL), and radiation shielding efficiency (RSE) were estimated and compared for all the different samples. The results prove that increasing the concentration of Bi2O3 leads to the enhancement of the radiation shielding properties of the AM as a shielding material. It was observed that as the energy increases, the efficiency of the samples falls. High energy dependence was found when calculating the HVL and TVL values of the samples, which increased with increases in the energy of the incident photons. A comparison between the sample with the most efficient gamma radiation attenuation capability (AM-25%), concrete, and lead was conducted, and a discussion regarding their radiation shielding properties is presented herein. The results show that the AM-25% sample is superior to the ordinary concrete over all the studied energy ranges, as evidenced by its significantly lower HVLs. On the contrary, lead is superior to the AM-25% sample over all the studied energy ranges owing to its unbeatable density as a shielding material. Overall, this new type of artificial marble has the potential to be used as a radiation shielding material at low- to medium-gamma energy regions, specifically in medical imaging and radiation therapy
Determination of 238U and 40K Radionuclide Concentrations in Some Granite Rocks by Gamma Spectroscopy and Energy Dispersive X-ray Analysis
Uranium-238 (238U) and potassium-40 (40K) are important naturally occurring radionuclides. Gamma spectroscopy is a direct, non-destructive method used to determine radionuclide concentrations, but it suffers from the interference of gamma lines. 40K gamma spectroscopy is affected by background interference, which leads to a reduction in the minimum detectable activity. The energy dispersive X-ray analytical technique is quick, with fewer interference problems or background effects. However, it is an indirect method for calculating and deducing the concentrations of isotopes. The aim of the present study was to compare and evaluate both techniques so that they can be utilized efficiently. The results of 238U and 40K were measured by well-calibrated gamma spectroscopy and energy dispersive X-ray techniques. the results indicated that Halayeb White granite is the most environmentally safe compared to the other two types because it contains a very low concentration of uranium 238 and potassium 40
Shielding Properties of Some Marble Types: A Comprehensive Study of Experimental and XCOM Results
In this work, some marble types were collected from Egypt, and their shielding characteristics were estimated. Their rigidity, in addition to their elegant shape, led us to consider their use as a protective shield, in addition to making the workplace more beautiful. The mass attenuation coefficient (μ/ρ) was calculated for three types of marble (Breshia, Galala, and Trista) experimentally, using a narrow gamma ray source and high pure germanium (HPGe). The results obtained were compared with the XCOM program and indicated a very good agreement between the two methods. The linear attenuation coefficient (μ) was evaluated to calculate the half and tenth value layers. The maximum μ value of 1.055, 1.041, and 1.024 cm−1 was obtained for Breshia, Galala, and Trista, respectively, at 0.06 MeV. The mean free path for studying the materials was compared with other shielding materials and showed good results at different energy scales. The energy absorption (EABF) and exposure buildup factors (EBF) were determined at different mean free paths. The fast neutron removal cross section ΣR was calculated and expresses the ability of the marbles to slow down fast neutrons through multiple scattering. This is the ability of the marbles to shield fast neutrons
The Potentials of Egyptian and Indian Granites for Protection of Ionizing Radiation
This paper aims to study the radiation shielding characteristics and buildup factor of some types of granite in Egypt. The mass attenuation coefficient (MAC) for three types of granite (gandola, white halayeb, and red aswani) was experimentally determined, and the experimental results were validated by XCOM software. The relative deviation between the two methods does not exceed 3% in all discussed granite samples, which means that MAC calculated through the experimental and XCOM are in suitable agreement. The effective atomic number (Zeff) varies from 13.64 to 10.69, 13.68 to 10.59, and 13.45 and 10.66 for gandola, white halayeb, and red aswani, respectively. As well as the equivalent atomic number (Zeq) was calculated in a wide range of energy to deduce the exposure (EBF) and energy absorption (EABF) buildup factors for the studied granite materials. The linear attenuation coefficient (LAC), half-value layer (HVL), mean free path (MFP) were calculated at each investigated energy and showed that the most effective shielding ability at high energy was red aswani, while at low energy, the shielding ability was nearly constant for studied granites. The present study forms the first endeavor to obtain the radiation shielding properties of the studied materials to be used in practical applications
Sex differences in oncogenic mutational processes
Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research.Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research.Peer reviewe