587 research outputs found

    A time-domain control signal detection technique for OFDM

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    Transmission of system-critical control information plays a key role in efficient management of limited wireless network resources and successful reception of payload data information. This paper uses an orthogonal frequency division multiplexing (OFDM) architecture to investigate the detection performance of a time-domain approach used to detect deterministic control signalling information. It considers a type of control information chosen from a finite set of information, which is known at both transmitting and receiving wireless terminals. Unlike the maximum likelihood (ML) estimation method, which is often used, the time-domain detection technique requires no channel estimation and no pilots as it uses a form of time-domain correlation as the means of detection. Results show that when compared with the ML method, the time-domain approach improves detection performance even in the presence of synchronisation error caused by carrier frequency offset

    Anti-CTLA4 monoclonal antibodies: the past and the future in clinical application

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    Recently, two studies using ipilimumab, an anti-CTLA-4 monoclonal antibody (mab) demonstrated improvements in overall survival in the treatment of advanced melanoma. These studies utilized two different schedules of treatment in different patient categories (first and second line of treatment). However, the results were quite similar despite of different dosage used and the combination with dacarbazine in the first line treatment. We reviewed the result of randomized phase II-III clinical studies testing anti-CTLA-4 antibodies (ipilimumab and tremelimumab) for the treatment of melanoma to focus on practical or scientific questions related to the broad utilization of these products in the clinics. These analyses raised some considerations about the future of these compounds, their potential application, dosage, the importance of the schedule (induction/manteinance compared to induction alone) and their role as adjuvants. Anti-CTLA-4 antibody therapy represents the start of a new era in the treatment of advanced melanoma but we are on the steep slope of the learning curve toward the optimization of their utilization either a single agents or in combination

    Glatiramer Acetate Treatment Normalizes Deregulated microRNA Expression in Relapsing Remitting Multiple Sclerosis

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    The expression of selected microRNAs (miRNAs) known to be involved in the regulation of immune responses was analyzed in 74 patients with relapsing remitting multiple sclerosis (RRMS) and 32 healthy controls. Four miRNAs (miR-326, miR-155, miR-146a, miR-142-3p) were aberrantly expressed in peripheral blood mononuclear cells from RRMS patients compared to controls. Although expression of these selected miRNAs did not differ between treatment-naïve (n = 36) and interferon-beta treated RRMS patients (n = 18), expression of miR-146a and miR-142-3p was significantly lower in glatiramer acetate (GA) treated RRMS patients (n = 20) suggesting that GA, at least in part, restores the expression of deregulated miRNAs in MS

    Influence of halloysite nanotubes on physical and mechanical properties of cellulose fibres reinforced vinyl ester composites

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    Natural fibres are generally added to polymer matrix composites to produce materials with the desirable mechanical properties of higher specific strength and higher specific modulus while at the same time to maintain a low density and low cost. The physical and mechanical properties of polymer composites can be enhanced through the addition of nanofillers such as halloysite nanotubes. This article describes the fabrication of vinyl ester eco-composites and eco-nanocomposites and characterizes these samples in terms of water absorption, mechanical and thermal properties. Weight gain test and Fourier transform infrared analysis indicated that 5% halloysite nanotube addition gave favourable reduction in the water absorption and increased the fibre–matrix adhesion leading to improved strength properties in the eco-nanocomposites. However, halloysite nanotube addition resulted in reduced toughness but improved thermal stability

    Objectively assessed physical activity and subsequent health service use of UK adults aged 70 and over: A four to five year follow up study

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    Objectives: To examine the associations between volume and intensity of older peoples' physical activity, with their subsequent health service usage over the following four to five years. Study Design: A prospective cohort design using baseline participant characteristics, objectively assessed physical activity and lower limb function provided by Project OPAL (Older People and Active Living). OPAL-PLUS provided data on numbers of primary care consultations, prescriptions, unplanned hospital admissions, and secondary care referrals, extracted from medical records for up to five years following the baseline OPAL data collection. Participants and Data Collection: OPAL participants were a diverse sample of 240 older adults with a mean age of 78 years. They were recruited from 12 General Practitioner surgeries from low, middle, and high areas of deprivation in a city in the West of England. Primary care consultations, secondary care referrals, unplanned hospital admissions, number of prescriptions and new disease diagnoses were assessed for 213 (104 females) of the original 240 OPAL participants who had either consented to participate in OPAL-PLUS or already died during the follow-up period. Results: In regression modelling, adjusted for socio-economic variables, existing disease, weight status, minutes of moderate-to-vigorous physical activity (MVPA) per day predicted subsequent numbers of prescriptions. Steps taken per day and MVPA also predicted unplanned hospital admissions, although the strength of the effect was reduced when further adjustment was made for lower limb function. Conclusions: Community-based programs are needed which are successful in engaging older adults in their late 70s and 80s in more walking, MVPA and activity that helps them avoid loss of physical function. There is a potential for cost savings to health services through reduced reliance on prescriptions and fewer unplanned hospital admissions. © 2014 Simmonds et al

    Coupling of CFD and semiempirical methods for designing three-phase condensate separator: case study and experimental validation

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    This study presents an approach to determine the dimensions of three-phase separators. First, we designed different vessel configurations based on the fluid properties of an Iranian gas condensate field. We then used a comprehensive computational fluid dynamic (CFD) method for analyzing the three-phase separation phenomena. For simulation purposes, the combined volume of fluid–discrete particle method (DPM) approach was used. The discrete random walk (DRW) model was used to include the effect of arbitrary particle movement due to variations caused by turbulence. In addition, the comparison of experimental and simulated results was generated using different turbulence models, i.e., standard k–ε, standard k–ω, and Reynolds stress model. The results of numerical calculations in terms of fluid profiles, separation performance and DPM particle behavior were used to choose the optimum vessel configuration. No difference between the dimensions of the optimum vessel and the existing separator was found. Also, simulation data were compared with experimental data pertaining to a similar existing separator. A reasonable agreement between the results of numerical calculation and experimental data was observed. These results showed that the used CFD model is well capable of investigating the performance of a three-phase separator

    Persistence of tumor-infiltrating CD8 T cells is tumor-dependent but antigen-independent

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    How tumor-infiltrating lymphocytes (TILs) that are tumor-specific but functionally tolerant persist in the antigen-expressing tumor tissue is largely unknown. We have previously developed a modified TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model where prostate cancer cells express the T-cell epitope SIYRYYGL (SIY) recognized by CD8 T cells expressing the 2C T-cell receptor (TCR) (referred to as TRP-SIY mice). In TRP-SIY mice, activated 2C T cells rapidly become tolerant following infiltration into the prostate tumor. In this study, we show that tolerant 2C T cells persist in the prostate tumor of TRP-SIY mice by proliferating slowly in a tumor-dependent, but antigen-, interleukin (IL)-7- and IL-15-independent manner. We also show that disappearance of 2C T cells from the lymphoid organs of TRP-SIY mice are due to antigen-induced T-cell contraction rather than altered trafficking or generalized T-cell depletion in the mice. Finally, we show that clonal T cells unreactive to SIY are equally capable of persisting in the prostate tumor. These findings suggest that while functional tolerance of TILs is induced by antigen, persistence of tolerant TILs in the tumor tissue is mediated by a novel mechanism: slow proliferation independent of antigen and homeostatic cytokines. These results also allow CD8 T-cell survival in the tumor environment to be compared with T-cell survival in chronic infection

    Sexual knowledge, attitudes and activity of men conscripted into the military

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    <p>Abstract</p> <p>Background</p> <p>Military conscripts may experience a change in their attitude towards sex at times when sexual urges are at their peak during their physical growth. This study examines the experience, understanding, knowledge and attitudes regarding sexual activity of the military conscripts.</p> <p>Methods</p> <p>Data was obtained from a cross-sectional survey of 1127 young adult military conscripts, and were evaluated in Southern Taiwan from January to July 2009, their demographic data, sexual knowledge, attitudes and activities were assessed.</p> <p>Results</p> <p>Nearly 43% of the participants had performed penetrative vaginal intercourse at least once; 34% of the participants performed heterosexual oral sex at least once; almost 7% of participants had had homosexual intercourse, and 7.5% of participants had experienced homosexual oral sex in the past year. The mean sexual knowledge score based on 30 questions was 23.2 ± 4.0. The higher the educational level of the participants, the greater sexual knowledge they had obtained.</p> <p>Conclusion</p> <p>This study found that 43% of unmarried young recruits had experienced premarital sexual activity. However, their sexual knowledge was insufficient and should be strengthened by sex education from an earlier age. College aged and adult learners also have sex education needs, especially with regard to integrating sexuality and life, being able to relate responsibly as sexual beings to others, the use of contraception, and about sexually transmitted disease.</p> <p>Keywords</p> <p>Young recruits, Sexual behavior, Sexual knowledge, Sex education</p
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