723 research outputs found
Editorial: Selected Papers from the 10th UK-Europe-China Workshop on Millimetre-waves and Terahertz Technologies (UCMMT) 2019
Study on Wideband THz Backward Wave Oscillator Driven by Pseudospark-Sourced Sheet Electron Beam
A backward wave oscillator (BWO) based on a double-staggered grating (DSG) slow wave structure (SWS) is investigated as a high-power wideband terahertz (THz) source, driven by a sheet electron beam emitting from a pseudospark plasma cathode. First, the DSG SWS is optimized in simulation to have a suitable dispersion characteristic. Then, the BWO with a wideband output structure consisting of a tapered section of DSG and an L-shaped connector is modeled under an operating voltage of 24-38 kV and a current density of 2- 5\times 10 {{7}} A/m 2 (beam current of 1.5-3.8 A). A maximum power of 3.9 kW is obtained, and a wide bandwidth of over 38 GHz (343-381 GHz) is achieved. The impact of fabricating errors of the SWS on the performance of the BWO is analyzed in simulation. The effects of the plasma in the interaction space on the BWO performance are also analyzed, showing that the plasma causes an increase in the oscillation frequency by 1.0-1.2
Experimental results from backward wave oscillators driven by a pseudospark-generated electron beam
The University of Strathclyde has investigated the applications of electron beams emitted by pseudospark (PS) discharges with an emphasis on their use in the production of radiation in the low terahertz range. To this end, backward wave oscillators (BWO), a form of vacuum tube which utilises the interaction between an axial electron beam and a slow-wave structure, have been designed and modelled using the particle-in-cell code MAGIC before construction of experiments. Successful millimetre radiation generated from BWOs at W-band (75GHz to 110GHz) driven by a 14-gap pseudospark discharge and G-band (140GHz to 220GHz) driven by a 4-gap pseudospark discharge will be presented
Quality of life among symptomatic compared to PSA-detected prostate cancer survivors - results from a UK wide patient-reported outcomes study
Background:
Quality of life among prostate cancer survivors varies by socio-demographic factors and treatment type received; however, less in known about differences in functional outcomes by method of presentation. We investigate differences in reported urinary, bowel, sexual and hormone-related problems between symptomatic and PSA-detected prostate cancer survivors.
Methods:
A UK wide cross-sectional postal survey of prostate cancer survivors conducted 18-42 months post-diagnosis. Questions were included on presentation method and treatment. Functional outcome was determined using the EPIC-26 questionnaire. Reported outcomes were compared for symptomatic and PSA-detected survivors using ANOVA and multivariable log-linear regression.
Results:
Thirty-five thousand eight hundred twenty-three men responded (response rate: 60.8%). Of these, 31.3% reported presenting via PSA test and 59.7% symptomatically. In multivariable analysis, symptomatic men reported more difficulty with urinary incontinence (Adjusted mean ratio (AMR): 0.96, 95% CI: 0.96-0.97), urinary irritation (AMR: 0.95, 95% CI: 0.95-0.96), bowel function (AMR: 0.97, 95% CI: 0.97-0.98), sexual function (AMR: 0.90, 95% CI: 0.88-0.92), and vitality/hormonal function (AMR: 0.96, 95% CI: 0.96-0.96) than PSA-detected men. Differences were consistent across respondents of differing age, stage, Gleason score and treatment type.
Conclusion:
Prostate cancer survivors presenting symptomatically report poorer functional outcomes than PSA-detected survivors. Differences were not explained by socio-demographic or clinical factors. Clinicians should be aware that men presenting with symptoms are more likely to report functional difficulties after prostate cancer treatment and may need additional aftercare if these difficulties persist. Method of presentation should be considered as a covariate in patient-reported outcome studies of prostate cancer
A review and meta-analysis of prospective studies of red and processed meat intake and prostate cancer
Over the past decade, several large epidemiologic investigations of meat intake and prostate cancer have been published. Therefore, a meta-analysis of prospective studies was conducted to estimate potential associations between red or processed meat intake and prostate cancer. Fifteen studies of red meat and 11 studies of processed meat were included in the analyses. High vs. low intake and dose-response analyses were conducted using random effects models to generate summary relative risk estimates (SRRE). No association between high vs. low red meat consumption (SRRE = 1.00, 95% CI: 0.96-1.05) or each 100 g increment of red meat (SRRE = 1.00, 95% CI: 0.95-1.05) and total prostate cancer was observed. Similarly, no association with red meat was observed for advanced prostate cancer (SRRE = 1.01, 95% CI: 0.94-1.09). A weakly elevated summary association between processed meat and total prostate cancer was found (SRRE = 1.05, 95% CI: 0.99-1.12), although heterogeneity was present, the association was attenuated in a sub-group analysis of studies that adjusted for multiple potential confounding factors, and publication bias likely affected the summary effect. In conclusion, the results of this meta-analysis are not supportive of an independent positive association between red or processed meat intake and prostate cancer
Contorted and ordinary body postures in the human brain
Social interaction and comprehension of non-verbal behaviour requires a representation of people’s bodies. Research into the neural underpinnings of body representation implicates several brain regions including extrastriate and fusiform body areas (EBA and FBA), superior temporal sulcus (STS), inferior frontal gyrus (IFG) and inferior parietal lobule (IPL). The different roles played by these regions in parsing familiar and unfamiliar body postures remain unclear. We examined the responses of this body observation network to static images of ordinary and contorted postures by using a repetition suppression design in functional neuroimaging. Participants were scanned whilst observing static images of a contortionist or a group of objects in either ordinary or unusual configurations, presented from different viewpoints. Greater activity emerged in EBA and FBA when participants viewed contorted compared to ordinary body postures. Repeated presentation of the same posture from different viewpoints lead to suppressed responses in the fusiform gyrus as well as three regions that are characteristically activated by observing moving bodies, namely STS, IFG and IPL. These four regions did not distinguish the image viewpoint or the plausibility of the posture. Together, these data define a broad cortical network for processing static body postures, including regions classically associated with action observation
Life after prostate cancer diagnosis: protocol for a UK-wide patient-reported outcomes study
Background: Prostate cancer and its treatment may impact physically, psychologically and socially; affecting the health-related quality of life of men and their partners/spouses. The Life After Prostate Cancer Diagnosis (LAPCD) study is a UK-wide patient-reported outcomes study which will generate information to improve the health and well-being of men with prostate cancer. Methods and analysis: Postal surveys will be sent to prostate cancer survivors (18–42 months postdiagnosis) in all 4 UK countries (n=∼70 000). Eligible men will be identified and/or verified through cancer registration systems. Men will be surveyed twice, 12 months apart, to explore changes in outcomes over time. Second, separate cohorts will be surveyed once and the design will include evaluation of the acceptability of online survey tools. A comprehensive patient-reported outcome measure has been developed using generic and specific instruments with proven psychometric properties and relevance in national and international studies. The outcome data will be linked with administrative health data (eg, treatment information from hospital data). To ensure detailed understanding of issues of importance, qualitative interviews will be undertaken with a sample of men who complete the survey across the UK (n=∼150) along with a small number of partners/spouses (n=∼30). Ethics and dissemination: The study has received the following approvals: Newcastle and North Tyneside 1 Research Ethics Committee (15/NE/0036), Health Research Authority Confidentiality Advisory Group (15/CAG/0110), NHS Scotland Public Benefit and Privacy Panel (0516-0364), Office of Research Ethics Northern Ireland (16/NI/0073) and NHS R&D approval from Wales, Scotland and Northern Ireland. Using traditional and innovative methods, the results will be made available to men and their partners/spouses, the funders, the NHS, social care, voluntary sector organisations and other researchers
The endogenous proteoglycan-degrading enzyme ADAMTS-4 promotes functional recovery after spinal cord injury
<p>Abstract</p> <p>Background</p> <p>Chondroitin sulfate proteoglycans are major inhibitory molecules for neural plasticity under both physiological and pathological conditions. The chondroitin sulfate degrading enzyme chondroitinase ABC promotes functional recovery after spinal cord injury, and restores experience-dependent plasticity, such as ocular dominance plasticity and fear erasure plasticity, in adult rodents. These data suggest that the sugar chain in a proteoglycan moiety is essential for the inhibitory activity of proteoglycans. However, the significance of the core protein has not been studied extensively. Furthermore, considering that chondroitinase ABC is derived from bacteria, a mammalian endogenous enzyme which can inactivate the proteoglycans' activity is desirable for clinical use.</p> <p>Methods</p> <p>The degradation activity of ADAMTS-4 was estimated for the core proteins of chondroitin sulfate proteoglycans, that is, brevican, neurocan and phosphacan. To evaluate the biological significance of ADMATS-4 activity, an <it>in vitro </it>neurite growth assay and an <it>in vivo </it>neuronal injury model, spinal cord contusion injury, were employed.</p> <p>Results</p> <p>ADAMTS-4 digested proteoglycans, and reversed their inhibition of neurite outgrowth. Local administration of ADAMTS-4 significantly promoted motor function recovery after spinal cord injury. Supporting these findings, the ADAMTS-4-treated spinal cord exhibited enhanced axonal regeneration/sprouting after spinal cord injury.</p> <p>Conclusions</p> <p>Our data suggest that the core protein in a proteoglycan moiety is also important for the inhibition of neural plasticity, and provides a potentially safer tool for the treatment of neuronal injuries.</p
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