2,040 research outputs found

    Support and power plant documentation for the gas turbine powered bus demonstration program

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    The operational experience obtained for the GT404-4 gas turbine engines in the intercity and intracity Bus Demonstration Programs is described for the period January 1980 through September 1981. Support for the engines and automatic transmissions involved in this program provided engineering and field service, spare parts and tools, training, and factory overhauls. the Greyhound (intercity) coaches accumulated 183,054 mi (294,595 km) and 5154 hr of total operation. The Baltimore Transit (intracity) coaches accumulated 40,567 mi (65,285 km) and 1840 hr of total operation. In service, the turbine powered Greyhound and Transit coaches achieved approximately 25% and 40% lower fuel mileage, respectively, than did the production diesel powered coaches. The gas turbine engine will require the advanced ceramic development currently being sponsored by the DOE and NASA to achieve fuel economy equivalent not only to that of today's diesel engines but also to the projected fuel economy of the advanced diesel engines of the 1990s. Sufficient experience was not achieved with the coaches prior to the start of service to identify and eliminate many of the problems associated with the startup of new equipment. Because of these problems, the mean miles between incident were unacceptably low. The future gas turbine system should be developed sufficiently to establish satisfactory durability prior to evaluation in revenue service. Commercialization of the gas turbine bus engine remains a viable goal for the future

    On the Integrable Structure of the Ising Model

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    Starting from the lattice A3A_3 realization of the Ising model defined on a strip with integrable boundary conditions, the exact spectrum (including excited states) of all the local integrals of motion is derived in the continuum limit by means of TBA techniques. It is also possible to follow the massive flow of this spectrum between the UV c=1/2c=1/2 conformal fixed point and the massive IR theory. The UV expression of the eigenstates of such integrals of motion in terms of Virasoro modes is found to have only rational coefficients and their fermionic representation turns out to be simply related to the quantum numbers describing the spectrum.Comment: 18 pages, no figure

    Bose-Einstein Condensation in Gap-Confined Exciton-Polariton States

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    The development of patterned multi-quantum well heterostructures in GaAs/AlGaAs waveguides has recently allowed to achieve exciton-polariton condensation in a topologically protected bound state in the continuum (BIC). Remarkably, condensation occurred above a saddle point of the polariton dispersion. A rigorous analysis of the condensation phenomenon in these systems, as well as the role of the BIC, is still missing. In the present Letter we theoretically and experimentally fill this gap, by showing that polariton confinement resulting from the negative effective mass and the photonic energy gap in the dispersion play a key role in enhancing the relaxation towards the condensed state. In fact, our results show that low-threshold polariton condensation is achieved within the effective trap created by the exciting laser spot regardless of whether the resulting confined mode is long-lived (polariton BIC) or short-lived (lossy mode). In both cases, the spatial quantization of the polariton condensate and the threshold differences associated to the corresponding state lifetime are measured and characterized. For a given negative mass, a slightly lower condensation threshold from the polariton BIC mode is found and associated to its suppressed radiative losses as compared to the lossy one

    BAP1 and YY1 regulate expression of death receptors in malignant pleural mesothelioma

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    Malignant pleural mesothelioma (MPM) is a rare, aggressive, and incurable cancer arising from the mesothelial lining of the pleura, with few available treatment options. We recently reported loss of function of the nuclear deubiquitinase BRCA1-associated protein 1 (BAP1), a frequent event in MPM, is associated with sensitivity to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. As a potential underlying mechanism, here we report that BAP1 negatively regulates the expression of TRAIL receptors: death receptors 4 (DR4) and 5 (DR5). Using tissue microarrays (TMAs) of tumour samples from MPM patients, we found a strong inverse correlation between BAP1 and TRAIL receptor expression. BAP1 knockdown increased DR4 and DR5 expression, whereas overexpression of BAP1 had the opposite effect. Reporter assays confirmed wild-type BAP1, but not catalytically-inactive mutant BAP1, reduced promoter activities of DR4 and DR5, suggesting deubiquitinase activity is required for the regulation of gene expression. Co-IP studies demonstrated direct binding of BAP1 to the transcription factor Ying Yang 1 (YY1), and ChIP assays revealed BAP1 and YY1 to be enriched in the promoter regions of DR4 and DR5. Knockdown of YY1 also increased DR4 and DR5 expression and sensitivity to TRAIL. These results suggest that BAP1 and YY1 cooperatively repress transcription of TRAIL receptors. Our finding that BAP1 directly regulates the extrinsic apoptotic pathway will provide new insights into the role of BAP1 in the development of MPM and other cancers with frequent BAP1 mutations

    Molecular diagnosis of SARS-CoV-2 in seminal fluid

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    Purpose Due to relevant repercussions on reproductive medicine, we aimed to evaluate feasibility of RT-PCR as a detection method of SARS-CoV-2 RNA in seminal fluid. Methods A qualitative determination of the RT-PCR assays in semen was performed through different approaches: (1) efficiency of RNA extraction from sperm and seminal plasma was determined using PRM1 and PRM2 mRNA and a heterologous system as control; (2) samples obtained by diluting viral preparation from a SARS-CoV-2 panel (virus cultured in Vero E6 cell lines) were tested; (3) viral presence in different fractions of seminal fluid (whole sample, seminal plasma and post-centrifugation pellet) was evaluated. Semen samples from mild and recovered COVID-19 subjects were collected by patients referring to the Infectious Disease Department of the Policlinico Umberto I Hospital - "Sapienza" University of Rome. Control subjects were recruited at the Laboratory of Seminology-Sperm Bank "Loredana Gandini'' of the same hospital. Results The control panel using viral preparations diluted in saline and seminal fluid showed the capability to detect viral RNA presence with C-t values depending on the initial viral concentration. All tested semen samples were negative for SARS-CoV-2, regardless of the nasopharyngeal swab result or seminal fluid fraction. Conclusion These preliminary data show that RT-PCR for SARS-CoV-2 RNA testing appears to be a feasible method for the molecular diagnosis of SARS-CoV-2 in seminal fluid, supported by results of the control panel. The ability to detect SARS-CoV-2 in semen is extremely important for reproductive medicine, especially in assisted reproductive technology and sperm cryopreservation

    Disease Rescue and Increased Lifespan in a Model of Cardiomyopathy and Muscular Dystrophy by Combined AAV Treatments

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    The BIO14.6 hamster is an excellent animal model for inherited cardiomyopathy, because of its lethal and well-documented course, due to a spontaneous deletion of delta-sarcoglycan gene promoter and first exon. The muscle disease is progressive and average lifespan is 11 months, because heart slowly dilates towards heart failure.Based on the ability of adeno-associated viral (AAV) vectors to transduce heart together with skeletal muscle following systemic administration, we delivered human delta-sarcoglycan cDNA into male BIO14.6 hamsters by testing different ages of injection, routes of administration and AAV serotypes. Body-wide restoration of delta-SG expression was associated with functional reconstitution of the sarcoglycan complex and with significant lowering of centralized nuclei and fibrosis in skeletal muscle. Motor ability and cardiac functions were completely rescued. However, BIO14.6 hamsters having less than 70% of fibers recovering sarcoglycan developed cardiomyopathy, even if the total rescued protein was normal. When we used serotype 2/8 in combination with serotype 2/1, lifespan was extended up to 22 months with sustained heart function improvement.Our data support multiple systemic administrations of AAV as a general therapeutic strategy for clinical trials in cardiomyopathies and muscle disorders

    DMSO and Temperature Contributions to Synthesis of Silver Nano-Particles by the Bacterium Shewanella oneidensis

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    Nanomaterial are widely used in different areas such as optical device, drug delivery, chemicals, mechanics, magnetics, catalysis, energy science, Nano therapeutics and space industries depend on the special physical properties. However, most methods to produce nanoparticles are expensive or environmental unfriendly which can involve in toxic chemical. Another reason is that the nanoparticles from bio-based protocols are hydrophilic which is compatible with biological materials. In this project, we chose Shewanella oneidensis which is Gram-negative bacterium as the organism to produce sliver nanoparticles from sliver nitrate solution. The mechanism of bacterial of ion metal ion reduction to stable metal nanoparticles is unclear, but the NADH-dependent reeducates, quinines, and soluble electron-shuttles are thought to play an important role in metal reduction. This research focused on the temperature and DMSO affects the synthesis of silver nanoparticles by Shewanella Oneidensis. At various temperatures, the bio-activity of bacterium is different which can affect the silver nanoparticles reducing rate and the spherical size and nanoparticle geometry. DMSO is an aprotic, polar solvent which can penetrate skin and other membranes without damaging the cells. Due to this property of DMSO, DMSO was utilized as a co-solvent, which may change biosynthesis of silver nanoparticles. The synthesis processes were carried out at different temperatures and DMSO concentration and the nanoparticle formation monitored by using UV-vis spectrometer scans of the aqueous layer of reaction at 0 hr, 24 hr and 48 hr.https://ecommons.udayton.edu/stander_posters/1429/thumbnail.jp

    DiagnĂłstico molecular de toxoplasmosis en pacientes con VIH-SIDA

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    Introducción: La toxoplasmosis en pacientes con Síndrome de Inmunodeficiencia Adquirida (SIDA) constituye un problema de salud pública en el mundo. El diagnóstico tardío de infección por el Virus de la Inmunodeficiencia Humana (VIH), pobre adherencia al tratamiento antirretroviral y falta de profilaxis contribuyen a esta situación.Objetivos: Proponemos una nueva estrategia basada en la utilización de un marcador molecular que contribuya al diagnóstico de toxoplasmosis en pacientes con VIH-SIDA.Materiales y Métodos: Se incorporaron en este estudio pacientes adultos con VIH-SIDA que reunían los siguientes criterios de inclusión: manifestaciones clínicas de toxoplasmosis (compromiso neurológico, ocular, respiratorio, en piel y forma latente) y resultado positivo mediante la reacción de cadena de polimerasa (PCR) utilizando el gen B1 en muestras de sangre. A cada paciente se le realizó la historia clínica, recuento de células CD4, y cuando fuera indicado estudios por imágenes identificando lesiones ocupantes de cerebro (LOC) o no, punción de líquido cefalorraquídeo (LCR) tomografía de tórax y lavado broncoalveolar (BAL). A muestras de LCR y BAL se les efectuó microscopia óptica y PCR.Resultados: Con esta metodología se estudiaron 24 pacientes, sexo masculino, con edades comprendidas entre 22 y 63 años (promedio 43 años). Se identificaron 2/24 casos con formas latentes y 22/24 (91%) casos con síntomas. Presentaron cuadros neurológicos 15/24 casos (62%), siendo LOC 6/15 con uno de ellos en confección con Trypanosoma cruzi, y no LOC 9/15. Clínica respiratoria se presentó en 7/24 (29%) casos: no coinfectados 4/7 casos, 2 con patrón radiológico intersticial y 2 con focal; coinfectados 3/7 casos. Un caso mostró compromiso ocular y uno con lesiones dermatológicas. El recuento de CD4 promedio fue 60 células/mm3. Se obtuvieron muestras de LCR en 15 casos y de BAL en 7. La PCR en LCR fue positiva en 2/15 casos y en BAL en 7/7 casos. La serología se realizó en 12/24 casos con títulos positivos en 9 casos.Conclusiones: Estos hallazgos demuestran el valor clínico que tiene el uso de la técnica de PCR para el diagnóstico de toxoplasmosis cerebral y más importante aún para la identificación de las otras formas clínicas que habitualmente son subdiagnosticadas.Fil: Velásquez, J. N.. No especifíca;Fil: Ledesma, B. A.. No especifíca;Fil: Nigro, M. G.. No especifíca;Fil: Vittar, N.. No especifíca;Fil: Figueiras, O.. No especifíca;Fil: Ricart, J.. No especifíca;Fil: della Paolera, D.. No especifíca;Fil: Carnevale, Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Corti, M.. No especifíca;VI Congreso de Enfermedades Endemoepidémicas del Hospital de Infecciosas Francisco J. MuñizCiudad Autónoma de Buenos AiresArgentinaHospital de Infecciosas "Francisco J. Muñiz

    Measurement of neutral current e+/-p cross sections at high Bjorken x with the ZEUS detector

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    The neutral current e+/-p cross section has been measured up to values of Bjorken x of approximately 1 with the ZEUS detector at HERA using an integrated luminosity of 187 inv. pb of e-p and 142 inv. pb of e+p collisions at sqrt(s) = 318GeV. Differential cross sections in x and Q2, the exchanged boson virtuality, are presented for Q2 geq 725GeV2. An improved reconstruction method and greatly increased amount of data allows a finer binning in the high-x region of the neutral current cross section and leads to a measurement with much improved precision compared to a similar earlier analysis. The measurements are compared to Standard Model expectations based on a variety of recent parton distribution functions.Comment: 39 pages, 9 figure
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