62 research outputs found
Liposarcomas in young patients: a study of 82 cases occurring in patients younger than 22 years of age.
No full textLiposarcomas typically occur in middle aged to older adults. Altogether, approximately 50 bona fide liposarcomas have been reported in children and adolescents, most of which have represented myxoid liposarcomas, with a good prognosis. We undertook a retrospective study of 82 liposarcomas occurring in patients below 22 years of age. Clinicopathologic and follow-up information was obtained. Fluorescence in situ hybridization for FUS, EWSR1, CHOP (DDIT3), and MDM2 was performed in 30 cases. The tumors occurred in 28 males and 54 females (5 to 22 y of age) and involved many locations. Fifty-six cases were typical myxoid liposarcomas, including 2 with round cell areas. The tumors were grade 1 (56 cases) and grade 3 (2 cases). Thirty-seven of 38 patients with follow-up are alive without disease and 1 is alive with disease (median 59 mo follow-up duration, range: 8 to 108 mo). Six cases showed myxoid liposarcoma with spindled growth ("spindle cell myxoid liposarcoma"); these arose in 5 females and 1 male (median age 14 y) and involved the thigh in 40% of cases. All were grade 1. Follow-up (4 of 6 patients) showed local recurrences in 2 cases and metastases in 1 case. Twelve tumors consisted of conventional myxoid liposarcoma and pleomorphic liposarcoma ("pleomorphic myxoid liposarcoma"); these arose in 4 males and 8 females (10 to 22 y of age) and often involved the mediastinum. Tumor grades were 2 (4 cases) and 3 (8 cases). Follow-up (10 patients) showed 7 dead of disease, 1 alive with disease, and 2 disease free. Four atypical lipomatous tumors were seen including 2 with low-grade dedifferentiation. Two local recurrences were seen; all patients are disease free. Two conventional pleomorphic liposarcomas were seen; 1 patient with follow-up is disease free. FUS-CHOP and EWSR1-CHOP rearrangements were identified by fluorescence in situ hybridization in 15/23 and 2/23 conventional myxoid liposarcomas, respectively, and in no other tumors. Amplification for MDM2 was absent in all cases. We conclude that conventional myxoid liposarcoma is by far the most common subtype of liposarcoma in young patients, with an excellent prognosis. Two apparently novel subtypes of liposarcoma, termed pleomorphic myxoid liposarcoma and spindle cell myxoid liposarcoma comprise considerable percentages of liposarcomas in this age group and should be distinguished from conventional myxoid liposarcoma and conventional pleomorphic liposarcoma. Pleomorphic myxoid liposarcoma and spindle cell myxoid liposarcoma most likely represent high-grade and low-grade variants of myxoid liposarcoma, respectively. Additional study of such cases will be necessary for definitive classification
Breast Cancer Imaging using a 24 GHz Ultra-Wideband MIMO FMCW Radar: System Considerations and First Imaging Results
No full textMicrowave imaging for breast cancer detection has been widely studied as an alternative technique to the conventional X-ray mammography. The systems developed until now operate at frequencies of a few gigahertz. This limits the achievable image quality. Higher operational frequencies are advantageous for achieving a better resolution, at the expense of a lower penetration depth. The downscaling of components together with an integrated radar transceiver would lead to the development of a compact and cost-effective radar imaging system. This paper investigates the possibility of using an integrated ultra-wideband frequency-modulated continuous-wave (FMCW) radar system operating at a center frequency of 20 GHz and bandwidth of 8 GHz for breast cancer imaging. System considerations are developed to assess the tumor detectability based on the signal attenuation within the breast and the radar sensitivity. A numerical simulation is conducted and first imaging results are presented
HIGHER EDUCATION EXPERIENCES IN KYRGYZSTAN: CASE OF OSH STATE UNIVERSITY
No full textIn this article, author describe some key aspects of higher education reforms and what have been the Osh State University's experiences in relation to these reforms
Managing Equipment for Emergency Obstetric Care in Rural Hospitals
No full textIn resource poor countries substantial sums of money, from governments and international donors, are used to purchase equipment for health facilities. WHO estimates that 50-80% of such equipment remains non-functional. This article is based on the experiences from various projects in developing countries in Asia and Africa. The key issues in the purchase, distribution, installation, management and maintenance of equipment for emergency obstetric care (EmOC) services are identified and discussed. Some positive examples are described to show how common equipment management problems are solved.
Design a novel methodology for the goal-directed control of epitaxial graphene fabrication
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The elusive 2D carbon poly-type was argued more than 70 years ago. Meanwhile, the recent discovery of graphene has proved that such materials can indeed be obtained and are thermodynamically stable. Graphene has demonstrated the unique properties that lead to many innovations in laboratory conditions. However, the current approaches available for the industrial fabrication yield the low graphene quality against the theoretical predictions. Furthermore, any graphene combination with the supporting units causes a newly-induced quality for adaptation to the other condensed matters. Therefore, the unusual ability for sensitive alteration in the external world has turned into a regulation for intended graphene engineering. The submitted investigation has been undertaken to elaborate a novel methodology for the goal-directed control of epitaxial graphene fabrication by using interaction design. This is the most perspective pathway to scale-up production of intended quality subjected to the manufacturing of novel carbide derived carbon (CDC) patterns via interaction with specific substrates under hydrogen halides impact. The graphene layers and structural arrangement of the composite systems, as well as their electronic properties depend on the particular substrate, coherent commensuration of the adjacent units, interaction between them and the physical environment of fabrication. It is crucial to understand the interaction processes leading to stable construction. Density Functional Theory (DFT) implemented in the CASTEP system has been employed in this research in order to develop this knowledge and also to determine how to tune and engineer the band gaps of such composite assemblies. The substrate alternating reconstructions, polarity of surface terminations, commensuration and number of layers, their stacking order and distances between constituting units are taken into consideration for intended simulation. The (3x3) and (√3x√3) reconstructions of 4H-SiC poly-type are the starting points for epitaxial growth (EG) on the Si-face and C-face unit cells. The results of the substrate induced interaction are interpreted via the versatility of band states gradually traced from the dehydrogenated SiC framework to CDC bi-layer. The distinctive feature resulted from the substrate influence is kept as the transitional band for different arrangements and locations in vicinity of the Fermi level. The first buffering C-plane reinforces substrate distinctions between the initial configurations and polarities. The n-type of gap state is the characteristic of the Si-face termination, whereas, the p-type is found for the C-face case. Both structures are devoid of the freestanding graphene signs. The appropriate indications of dominant graphene identity are found for the (0001) - (√3x√3) substrate only, at a close distance between two upper C-planes acceptable for covalent bonds.
As for graphene EG the chemical conversion by using fluorination is employed to avoid the possible damage inspired by initial substrate roughness. The few layered CDC assemblage on the (0001) - (√3x√3) support is trailed via gradual Si – F interaction and SiFx groups penetrating through the bulk. Regular control over potential energy surfaces, minimal energy pathways, transition states and activation barriers enable the indicative indexes for reaction credibility and progress. By means of the Arrhenius equation using the activation energy values the average temperature of 1500 - 2000 C are predicted for the real conversion events. Under these conditions the wet surface etching for the topmost Si-atoms and release of oxidised CDC are accompanied with a complementary promotion mechanism which resulted in a highly ordered graphene structure.Brunel University’s EPSRC Doctoral Training Account and UK Engineering and Physical Sciences Research Council (EPSRC
Experimental Study on Crosstalk Reduction between Integrated Inductors up to Millimeter-Wave Regime
No full textHighly-Integrated Low-Power 60 GHz Multichannel Transceiver for Radar Applications in 28 nm CMOS
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