148 research outputs found

    БСлСкция ΠΈ компСнсация сигналов спуфинга Π² граТданской Π°ΠΏΠΏΠ°Ρ€Π°Ρ‚ΡƒΡ€Π΅ потрСбитСля глобальной Π½Π°Π²ΠΈΠ³Π°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΉ спутниковой систСмы с многоканальной ΠΏΡ€ΠΈΠ΅ΠΌΠ½ΠΎΠΉ систСмой

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    A method for selecting spoofing signals in consumer equipment with a multichannel antenna system is proposed. The method provides for consistent filtering of the received signals at the outputs of all antenna system elements and by ranging codes of all navigation satellites, detection and measurement of the time delay of the true and false navigation signals in each code channel by the output signal of one of the antenna system elements, measurement of the phase difference of the signals at the outputs of the antenna system elements and the selected reference element for the estimated time delay in each channel by code. Compensation of spoofing signals is carried out in the spatial domain by estimating the correlation matrix of processes at the outputs of the antenna system channels by the corresponding countdown of code channel signals after matched filtering and forming of a weight vector while minimizing the output power of spoofing signals by directly inverting the estimate of the correlation matrix and carrying out weight processing of the adopted implementation. The simulation results are presented, confirming the efficiency of the method.ΠŸΡ€Π΅Π΄Π»ΠΎΠΆΠ΅Π½ ΠΌΠ΅Ρ‚ΠΎΠ΄ сСлСкции сигналов спуфинга (ΠΎΡ‚ Π°Π½Π³Π». spoofing – ΠΏΠΎΠ΄ΠΌΠ΅Π½Π°) Π² граТданской Π°ΠΏΠΏΠ°Ρ€Π°Ρ‚ΡƒΡ€Π΅ потрСбитСля с многоканальной Π°Π½Ρ‚Π΅Π½Π½ΠΎΠΉ систСмой. ΠœΠ΅Ρ‚ΠΎΠ΄ ΠΏΡ€Π΅Π΄ΠΏΠΎΠ»Π°Π³Π°Π΅Ρ‚ ΡΠΎΠ³Π»Π°ΡΠΎΠ²Π°Π½Π½ΡƒΡŽ Ρ„ΠΈΠ»ΡŒΡ‚Ρ€Π°Ρ†ΠΈΡŽ ΠΏΡ€ΠΈΠ½ΠΈΠΌΠ°Π΅ΠΌΡ‹Ρ… сигналов Π½Π° Π²Ρ‹Ρ…ΠΎΠ΄Π°Ρ… всСх элСмСнтов Π°Π½Ρ‚Π΅Π½Π½ΠΎΠΉ систСмы ΠΈ ΠΏΠΎ Π΄Π°Π»ΡŒΠ½ΠΎΠΌΠ΅Ρ€Π½Ρ‹ΠΌ ΠΊΠΎΠ΄Π°ΠΌ всСх Π½Π°Π²ΠΈΠ³Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… спутников, ΠΎΠ±Π½Π°Ρ€ΡƒΠΆΠ΅Π½ΠΈΠ΅ ΠΈ ΠΈΠ·ΠΌΠ΅Ρ€Π΅Π½ΠΈΠ΅ Π²Ρ€Π΅ΠΌΠ΅Π½ Π·Π°Π΄Π΅Ρ€ΠΆΠΊΠΈ истинных ΠΈ Π»ΠΎΠΆΠ½Ρ‹Ρ… Π½Π°Π²ΠΈΠ³Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… сигналов Π² ΠΊΠ°ΠΆΠ΄ΠΎΠΌ ΠΊΠΎΠ΄ΠΎΠ²ΠΎΠΌ ΠΊΠ°Π½Π°Π»Π΅ ΠΏΠΎ Π²Ρ‹Ρ…ΠΎΠ΄Π½ΠΎΠΌΡƒ сигналу ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈΠ· элСмСнтов Π°Π½Ρ‚Π΅Π½Π½ΠΎΠΉ систСмы, ΠΈΠ·ΠΌΠ΅Ρ€Π΅Π½ΠΈΠ΅ разности Ρ„Π°Π· сигналов Π½Π° Π²Ρ‹Ρ…ΠΎΠ΄Π°Ρ… элСмСнтов Π°Π½Ρ‚Π΅Π½Π½ΠΎΠΉ систСмы ΠΈ Π²Ρ‹Π±Ρ€Π°Π½Π½ΠΎΠ³ΠΎ ΠΎΠΏΠΎΡ€Π½ΠΎΠ³ΠΎ элСмСнта ΠΏΠΎ расчСтным Π²Ρ€Π΅ΠΌΠ΅Π½Π°ΠΌ Π·Π°Π΄Π΅Ρ€ΠΆΠΊΠΈ Π² ΠΊΠ°ΠΆΠ΄ΠΎΠΌ ΠΊΠ°Π½Π°Π»Π΅ ΠΏΠΎ ΠΊΠΎΠ΄Ρƒ. ΠšΠΎΠΌΠΏΠ΅Π½ΡΠ°Ρ†ΠΈΡ сигналов спуфинга осущСствляСтся Π² пространствСнной области ΠΏΡƒΡ‚Π΅ΠΌ оцСнивания коррСляционной ΠΌΠ°Ρ‚Ρ€ΠΈΡ†Ρ‹ процСссов Π½Π° Π²Ρ‹Ρ…ΠΎΠ΄Π°Ρ… ΠΊΠ°Π½Π°Π»ΠΎΠ² Π°Π½Ρ‚Π΅Π½Π½ΠΎΠΉ систСмы ΠΏΠΎ ΡΠΎΠΎΡ‚Π²Π΅Ρ‚ΡΡ‚Π²ΡƒΡŽΡ‰ΠΈΠΌ отсчСтам сигналов ΠΊΠΎΠ΄ΠΎΠ²Ρ‹Ρ… ΠΊΠ°Π½Π°Π»ΠΎΠ² послС согласованной Ρ„ΠΈΠ»ΡŒΡ‚Ρ€Π°Ρ†ΠΈΠΈ, формирования вСсового Π²Π΅ΠΊΡ‚ΠΎΡ€Π° ΠΏΡ€ΠΈ ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ Π²Ρ‹Ρ…ΠΎΠ΄Π½ΠΎΠΉ мощности сигналов спуфинга ΠΏΡƒΡ‚Π΅ΠΌ нСпосрСдствСнного обращСния ΠΎΡ†Π΅Π½ΠΊΠΈ коррСляционной ΠΌΠ°Ρ‚Ρ€ΠΈΡ†Ρ‹ ΠΈ провСдСния вСсовой ΠΎΠ±Ρ€Π°Π±ΠΎΡ‚ΠΊΠΈ принятой Ρ€Π΅Π°Π»ΠΈΠ·Π°Ρ†ΠΈΠΈ. ΠŸΡ€Π΅Π΄ΡΡ‚Π°Π²Π»Π΅Π½Ρ‹ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ модСлирования, ΠΏΠΎΠ΄Ρ‚Π²Π΅Ρ€ΠΆΠ΄Π°ΡŽΡ‰ΠΈΠ΅ ΡΡ„Ρ„Π΅ΠΊΡ‚ΠΈΠ²Π½ΠΎΡΡ‚ΡŒ ΠΌΠ΅Ρ‚ΠΎΠ΄Π°

    БСлСкция ΠΈ компСнсация сигналов спуфинга Π² граТданской Π°ΠΏΠΏΠ°Ρ€Π°Ρ‚ΡƒΡ€Π΅ потрСбитСля глобальной Π½Π°Π²ΠΈΠ³Π°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΉ спутниковой систСмы с многоканальной ΠΏΡ€ΠΈΠ΅ΠΌΠ½ΠΎΠΉ систСмой

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    A method for selecting spoofing signals in consumer equipment with a multichannel antenna system is proposed. The method provides for consistent filtering of the received signals at the outputs of all antenna system elements and by ranging codes of all navigation satellites, detection and measurement of the time delay of the true and false navigation signals in each code channel by the output signal of one of the antenna system elements, measurement of the phase difference of the signals at the outputs of the antenna system elements and the selected reference element for the estimated time delay in each channel by code. Compensation of spoofing signals is carried out in the spatial domain by estimating the correlation matrix of processes at the outputs of the antenna system channels by the corresponding countdown of code channel signals after matched filtering and forming of a weight vector while minimizing the output power of spoofing signals by directly inverting the estimate of the correlation matrix and carrying out weight processing of the adopted implementation. The simulation results are presented, confirming the efficiency of the method

    Autologous stem cell transplantation with low-dose cyclophosphamide to improve mucosal healing in adults with refractory Crohn's disease: the ASTIClite RCT

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    Some text in this abstract has been reproduced from Lindsay J, Din S, Hawkey C, Hind D, Irving P, Lobo A, et al. OFR-9 An RCT of autologous stem-cell transplantation in treatment refractory Crohn’s disease (low-intensity therapy evaluation): ASTIClite. Gut 2021;70(Suppl. 4):A4. Background Treatment-refractory Crohn’s disease is characterised by chronic symptoms, poor quality of life and high costs to the NHS, and through days of work lost by patients. A previous trial of autologous haematopoietic stem cell transplant (HSCT) failed its end point of medication-free clinical remission for 3 months with no evidence of disease activity, and reported high toxicity. Subsequent studies suggest that HSCT achieves complete mucosal healing in 50% of patients, and that toxicity likely relates to the cyclophosphamide dose. Objectives The primary objective was to assess the efficacy of HSCTlite (HSCT with low-dose cyclophosphamide) compared with standard care for inducing regression of intestinal ulceration in patients with refractory Crohn’s disease at week 48. Secondary objectives included the assessment of disease activity, quality of life and regimen safety. Mechanistic objectives included immune reconstitution after HSCTlite. Design Two-arm, parallel-group randomised controlled trial with a 2 : 1 (intervention : control) allocation ratio. Setting Nine NHS trusts (eight trusts were recruitment sites; one trust was a treatment-only site). Participants Adults with treatment-refractory Crohn’s disease, for whom surgery was inappropriate or who had declined surgery. Interventions The intervention treatment was HSCTlite using cyclophosphamide, and the control was any current available treatment for Crohn’s disease, apart from stem cell transplantation. Main outcomes The primary outcome was treatment success at week 48 [mucosal healing (Simple Endoscopic Score for Crohn’s Disease ulcer subscore of 0) without surgery or death], assessed by central readers blinded to allocation and timing of assessment. Key secondary outcomes were clinical remission, Simple Endoscopic Score for Crohn’s Disease scores at week 48, change in Crohn’s Disease Activity Index scores and safety. Results The trial was halted owing to Suspected unexpected serious adverse events that took place after randomising 23 patients (HSCTlite arm, n = 13; usual-care arm, n = 10). Ten out of the 13 patients randomised to the HSCTlite arm received the intervention and nine (one death) reached the 48-week follow-up. In the usual-care arm 9 out of the 10 patients randomised reached the 48-week follow-up (one ineligible). The primary outcome was available for 7 out of 10 HSCTlite patients (including the patient who died) and six out of nine usual-care patients. Absence of endoscopic ulceration without surgery or death was reported in three out of seven (43%) HSCTlite patients, compared with zero out of six (0%) usual-care patients. Centrally read Simple Endoscopic Score for Crohn’s Disease scores [mean (standard deviation)] were 10.8 (6.3) and 10.0 (6.1) at baseline, compared with 2.8 (2.9) and 18.7 (9.1) at week 48, in the HSCT and usual-care arms, respectively. Clinical remission (Crohn’s Disease Activity Index scores of < 150) occurred in 57% and 17% of patients in the HSCTlite and usual-care arms, respectively, at week 48. Serious adverse events were more frequent in the HSCTlite arm [38 in 13 (100%) patients] than in the usual-care arm [16 in 4 (40%) patients]. Nine suspected unexpected serious adverse reactions were reported in six HSCTlite patients, including three cases of delayed renal failure due to proven thrombotic microangiopathy. Two HSCTlite patients died. Conclusions Within the limitations of reduced patient recruitment and numbers of patients assessed, HSCTlite meaningfully reduced endoscopic disease activity, with three patients experiencing resolution of ulceration. Suspected unexpected serious adverse reactions, particularly relating to thrombotic microangiopathy, make this regimen unsuitable for future clinical use. Limitations The early trial closure prevented complete recruitment, and the impact of the coronavirus pandemic prevented completion of some study investigations. Small participant numbers meant analysis could only be descriptive. Future work Owing to undetermined aetiology of thrombotic microangiopathy, further trials of HSCTlite in this population are not considered appropriate. Priorities should be to determine optimal treatment strategies for patients with refractory Crohn’s disease, including those with a stoma or multiple previous resections

    Flexor Injury Rehabilitation Splint Trial (FIRST): protocol for a pragmatic randomised controlled trial comparing three splints for finger flexor tendon repairs

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    Background Without surgical repair, flexor tendon injuries do not heal and patients’ ability to bend fingers and grip objects is impaired. However, flexor tendon repair surgery also requires optimal rehabilitation. There are currently three custom-made splints used in the rehabilitation of zone I/II flexor tendon repairs, each with different assumed harm/benefit profiles: the dorsal forearm and hand-based splint (long), the Manchester short splint (short), and the relative motion flexion splint (mini). There is, however, no robust evidence as to which splint, if any, is most clinical or cost effective. The Flexor Injury Rehabilitation Splint Trial (FIRST) was designed to address this evidence gap. Methods FIRST is a parallel group, superiority, analyst-blind, multi-centre, individual participant-randomised controlled trial. Participants will be assigned 1:1:1 to receive either the long, short, or mini splint. We aim to recruit 429 participants undergoing rehabilitation following zone I/II flexor tendon repair surgery. Potential participants will initially be identified prior to surgery, in NHS hand clinics across the UK, and consented and randomised at their splint fitting appointment post-surgery. The primary outcome will be the mean post-randomisation score on the patient-reported wrist and hand evaluation measure (PRWHE), assessed at 6, 12, 26, and 52 weeks post randomisation. Secondary outcome measures include blinded grip strength and active range of movement (AROM) assessments, adverse events, adherence to the splinting protocol (measured via temperature sensors inserted into the splints), quality of life assessment, and further patient-reported outcomes. An economic evaluation will assess the cost-effectiveness of each splint, and a qualitative sub-study will evaluate participants’ preferences for, and experiences of wearing, the splints. Furthermore, a mediation analysis will determine the relationship between patient preferences, splint adherence, and splint effectiveness. Discussion FIRST will compare the three splints with respect to clinical efficacy, complications, quality of life and cost-effectiveness. FIRST is a pragmatic trial which will recruit from 26 NHS sites to allow findings to be generalisable to current clinical practice in the UK. It will also provide significant insights into patient experiences of splint wear and how adherence to splinting may impact outcomes. Trial registration ISRCTN: 1023601

    β€˜Fish out of water’: a cross-sectional study on the interaction between social and neighbourhood effects on weight management behaviours

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    Objective: To analyse whether an individual’s neighbourhood influences the uptake of weight management strategies and whether there is an interaction between individual socio-economic status and neighbourhood deprivation. Methodology: Data were collected from the Yorkshire Health Study (2010–2012) for 27 806 individuals on the use of the following weight management strategies: β€˜slimming clubs’, β€˜healthy eating’, β€˜increasing exercise’ and β€˜controlling portion size’. A multi-level logistic regression was fit to analyse the use of these strategies, controlling for age, sex, body mass index, education, neighbourhood deprivation and neighbourhood population turnover (a proxy for neighbourhood social capital). A cross-level interaction term was included for education and neighbourhood deprivation. Lower Super Output Area was used as the geographical scale for the areal unit of analysis. Results: Significant neighbourhood effects were observed for use of β€˜slimming clubs’, β€˜healthy eating’ and β€˜increasing exercise’ as weight management strategies, independent of individual- and area-level covariates. A significant interaction between education and neighbourhood deprivation was observed across all strategies, suggesting that as an area becomes more deprived, individuals of the lowest education are more likely not to use any strategy compared with those of the highest education. Conclusions: Neighbourhoods modify/amplify individual disadvantage and social inequalities, with individuals of low education disproportionally affected by deprivation. It is important to include neighbourhood-based explanations in the development of community-based policy interventions to help tackle obesit

    The MAGIC trial: a pragmatic, multicentre, parallel, noninferiority, randomised trial of melatonin versus midazolam in the premedication of anxious children attending for elective surgery under general anaesthesia

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    \ua9 2023 The Author(s)Background: Child anxiety before general anaesthesia and surgery is common. Midazolam is a commonly used premedication to address this. Melatonin is an alternative anxiolytic, however trials evaluating its efficacy in children have delivered conflicting results. Methods: This multicentre, double-blind randomised trial was performed in 20 UK NHS Trusts. A sample size of 624 was required to declare noninferiority of melatonin. Anxious children, awaiting day case elective surgery under general anaesthesia, were randomly assigned 1:1 to midazolam or melatonin premedication (0.5 mg kgβˆ’1, maximum 20 mg) 30 min before transfer to the operating room. The primary outcome was the modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF). Secondary outcomes included safety. Results are presented as n (%) and adjusted mean differences with 95% confidence intervals. Results: The trial was stopped prematurely (n=110; 55 per group) because of recruitment futility. Participants had a median age of 7 (6–10) yr, and 57 (52%) were female. Intention-to-treat and per-protocol modified Yale Preoperative Anxiety Scale-Short Form analyses showed adjusted mean differences of 13.1 (3.7–22.4) and 12.9 (3.1–22.6), respectively, in favour of midazolam. The upper 95% confidence interval limits exceeded the predefined margin of 4.3 in both cases, whereas the lower 95% confidence interval excluded zero, indicating that melatonin was inferior to midazolam, with a difference considered to be clinically relevant. No serious adverse events were seen in either arm. Conclusion: Melatonin was less effective than midazolam at reducing preoperative anxiety in children, although the early termination of the trial increases the likelihood of bias. Clinical trial registration: ISRCTN registry: ISRCTN18296119

    Albumin and multiple sclerosis

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    A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Leakage of the blood–brain barrier (BBB) is a common pathological feature in multiple sclerosis (MS). Following a breach of the BBB, albumin, the most abundant protein in plasma, gains access to CNS tissue where it is exposed to an inflammatory milieu and tissue damage, e.g., demyelination. Once in the CNS, albumin can participate in protective mechanisms. For example, due to its high concentration and molecular properties, albumin becomes a target for oxidation and nitration reactions. Furthermore, albumin binds metals and heme thereby limiting their ability to produce reactive oxygen and reactive nitrogen species. Albumin also has the potential to worsen disease. Similar to pathogenic processes that occur during epilepsy, extravasated albumin could induce the expression of proinflammatory cytokines and affect the ability of astrocytes to maintain potassium homeostasis thereby possibly making neurons more vulnerable to glutamate exicitotoxicity, which is thought to be a pathogenic mechanism in MS. The albumin quotient, albumin in cerebrospinal fluid (CSF)/albumin in serum, is used as a measure of blood-CSF barrier dysfunction in MS, but it may be inaccurate since albumin levels in the CSF can be influenced by multiple factors including: 1) albumin becomes proteolytically cleaved during disease, 2) extravasated albumin is taken up by macrophages, microglia, and astrocytes, and 3) the location of BBB damage affects the entry of extravasated albumin into ventricular CSF. A discussion of the roles that albumin performs during MS is put forth

    The MAGIC trial: a pragmatic, multicentre, parallel, noninferiority, randomised trial of melatonin versus midazolam in the premedication of anxious children attending for elective surgery under general anaesthesia

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    BACKGROUND: Child anxiety before general anaesthesia and surgery is common. Midazolam is a commonly used premedication to address this. Melatonin is an alternative anxiolytic, however trials evaluating its efficacy in children have delivered conflicting results. METHODS: This multicentre, double-blind randomised trial was performed in 20 UK NHS Trusts. A sample size of 624 was required to declare noninferiority of melatonin. Anxious children, awaiting day case elective surgery under general anaesthesia, were randomly assigned 1:1 to midazolam or melatonin premedication (0.5 mg kg-1, maximum 20 mg) 30 min before transfer to the operating room. The primary outcome was the modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF). Secondary outcomes included safety. Results are presented as n (%) and adjusted mean differences with 95% confidence intervals. RESULTS: The trial was stopped prematurely (n=110; 55 per group) because of recruitment futility. Participants had a median age of 7 (6-10) yr, and 57 (52%) were female. Intention-to-treat and per-protocol modified Yale Preoperative Anxiety Scale-Short Form analyses showed adjusted mean differences of 13.1 (3.7-22.4) and 12.9 (3.1-22.6), respectively, in favour of midazolam. The upper 95% confidence interval limits exceeded the predefined margin of 4.3 in both cases, whereas the lower 95% confidence interval excluded zero, indicating that melatonin was inferior to midazolam, with a difference considered to be clinically relevant. No serious adverse events were seen in either arm. CONCLUSION: Melatonin was less effective than midazolam at reducing preoperative anxiety in children, although the early termination of the trial increases the likelihood of bias. CLINICAL TRIAL REGISTRATION: ISRCTN registry: ISRCTN18296119
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