High Data Rate Narrowband PLC Communication based on OFDM

Tato bakalářská práce se zabývá úzkopásmovou PLC komunikací. V práci je popisována historie, princip úzkopásmové komunikace a popis čtyř dostupných úzkopásmových standardů (PRIME, G3-PLC, G.hnem, IEEE P1901.2) s jejich porovnáním. V další části jsou popisována experimentální měření, která jsou prováděna v domácím prostředí za použití dostupných modemů TMDSPLCKIT od firmy Texas Instruments, MT39-L1-ver.R modemů od firmy ModemTec a EVALKITST7580-1 od firmy STMicroelectronics.This bachelor project is about narrowband PLC communication. In this project is described history, principle of narrowband communication and description of four available narrowband standards (PRIME, G3-PLC, G.hnem, IEEE P1901.2) with their comparisons. In the next part are described the experimental measurements, that are performed in home environment with use of the TMDSPLCKIT modems from the Texas Instruments company, MT39-L1-ver.R modems from the ModemTec company and EVALKITST7580-1 modems from the STMicroelectronics company.

Power line grid model

Tato diplomová práce se zabývá analýzou PLC komunikací při různých scénářích. V první části je představen princip úzkopásmové a širokopásmové komunikace a analýza elektrického vedení. V další části je popisován NS-3 framework, simulační scénáře pro zjištění vlivu odboček a dalších parametrů na přenosovou rychlost. V poslední části je zjišťován minimální počet opakovačů a určení jejich umístění na rozšířené topologii.This diploma thesis analyzes the PLC communications in various scenarios. The first part of the thesis describes the principle of narrowband and broadband communication and the analysis of electrical lines. The next part describes the NS-3 framework, simulation scenarios for establishment the effect of branches and other parameters on the baud rate. The last part determines the minimum number of repeaters and their location on the extended topology.

Prediction of early recurrent thromboembolic event and major bleeding in patients with acute stroke and atrial fibrillation by a risk stratification schema: the ALESSA score study

Background and Purposes—This study was designed to derive and validate a score to predict early ischemic events and major bleedings after an acute ischemic stroke in patients with atrial fibrillation. Methods—The derivation cohort consisted of 854 patients with acute ischemic stroke and atrial fibrillation included in prospective series between January 2012 and March 2014. Older age (hazard ratio 1.06 for each additional year; 95% confidence interval, 1.00–1.11) and severe atrial enlargement (hazard ratio, 2.05; 95% confidence interval, 1.08–2.87) were predictors for ischemic outcome events (stroke, transient ischemic attack, and systemic embolism) at 90 days from acute stroke. Small lesions (≤1.5 cm) were inversely correlated with both major bleeding (hazard ratio, 0.39; P=0.03) and ischemic outcome events (hazard ratio, 0.55; 95% confidence interval, 0.30–1.00). We assigned to age ≥80 years 2 points and between 70 and 79 years 1 point; ischemic index lesion >1.5 cm, 1 point; severe atrial enlargement, 1 point (ALESSA score). A logistic regression with the receiver-operating characteristic graph procedure (C statistic) showed an area under the curve of 0.697 (0.632–0.763; P=0.0001) for ischemic outcome events and 0.585 (0.493–0.678; P=0.10) for major bleedings. Results—The validation cohort consisted of 994 patients included in prospective series between April 2014 and June 2016. Logistic regression with the receiver-operating characteristic graph procedure showed an area under the curve of 0.646 (0.529–0.763; P=0.009) for ischemic outcome events and 0.407 (0.275–0.540; P=0.14) for hemorrhagic outcome events. Conclusions—In acute stroke patients with atrial fibrillation, high ALESSA scores were associated with a high risk of ischemic events but not of major bleedings

Sex-related differences in risk factors, type of treatment received and outcomes in patients with atrial fibrillation and acute stroke: Results from the RAF-study (Early Recurrence and Cerebral Bleeding in Patients with Acute Ischemic Stroke and Atrial Fibrillation)

Introduction: Atrial fibrillation is an independent risk factor of thromboembolism. Women with atrial fibrillation are at a higher overall risk for stroke compared to men with atrial fibrillation. The aim of this study was to evaluate for sex differences in patients with acute stroke and atrial fibrillation, regarding risk factors, treatments received and outcomes. Methods Data were analyzed from the “Recurrence and Cerebral Bleeding in Patients with Acute Ischemic Stroke and Atrial Fibrillation” (RAF-study), a prospective, multicenter, international study including only patients with acute stroke and atrial fibrillation. Patients were followed up for 90 days. Disability was measured by the modified Rankin Scale (0–2 favorable outcome, 3–6 unfavorable outcome). Results: Of the 1029 patients enrolled, 561 were women (54.5%) (p < 0.001) and younger (p < 0.001) compared to men. In patients with known atrial fibrillation, women were less likely to receive oral anticoagulants before index stroke (p = 0.026) and were less likely to receive anticoagulants after stroke (71.3% versus 78.4%, p = 0.01). There was no observed sex difference regarding the time of starting anticoagulant therapy between the two groups (6.4 ± 11.7 days for men versus 6.5 ± 12.4 days for women, p = 0.902). Men presented with more severe strokes at onset (mean NIHSS 9.2 ± 6.9 versus 8.1 ± 7.5, p < 0.001). Within 90 days, 46 (8.2%) recurrent ischemic events (stroke/TIA/systemic embolism) and 19 (3.4%) symptomatic cerebral bleedings were found in women compared to 30 (6.4%) and 18 (3.8%) in men (p = 0.28 and p = 0.74). At 90 days, 57.7% of women were disabled or deceased, compared to 41.1% of the men (p < 0.001). Multivariate analysis did not confirm this significance. Conclusions: Women with atrial fibrillation were less likely to receive oral anticoagulants prior to and after stroke compared to men with atrial fibrillation, and when stroke occurred, regardless of the fact that in our study women were younger and with less severe stroke, outcomes did not differ between the sexes

Timing of initiation of oral anticoagulants in patients with acute ischemic stroke and atrial fibrillation comparing posterior and anterior circulation strokes

Background: The aim of this study in patients with acute posterior ischemic stroke (PS) and atrial fibrillation (AF) were to evaluate the risks of recurrent ischemic event and severe bleeding and these risks in relation with oral anticoagulant therapy (OAT) and its timing. Methods: Patients with PS were prospectively included; the outcome events of these patients were compared with those of patients with anterior stroke (AS) which were taken from previous registries. The primary outcome was the composite of: stroke recurrence, TIA, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding occurring within 90 days from acute stroke. Results: A total of 2,470 patients were available for the analysis: 473 (19.1%) with PS and 1,997 (80.9%) AS. Over 90 days, 213 (8.6%) primary outcome events were recorded: 175 (8.7%) in patients with AS and 38 (8.0%) in those with PS. In patients who initiated OAT within 2 days, the primary outcome occurred in 5 out of 95 patients (5.3%) with PS compared to 21 out of 373 patients (4.3%) with AS (OR 1.07; 95% CI 0.39-2.94). In patients who initiated OAT between days 3 and 7, the primary outcome occurred in 3 out of 103 patients (2.9%) with PS compared to 26 out of 490 patients (5.3%) with AS (OR 0.54; 95% CI 0.16-1.80). Conclusions: Patients with posterior or anterior stroke and AF appear to have similar risks of ischemic or hemorrhagic events at 90 days with no difference concerning the timing of initiation of OAT

Hemorrhagic transformation in acute ischemic stroke patients and atrial fibrillation: time to initiation of anticoagulants and outcome

Background: In patients with acute ischemic stroke and atrial fibrillation, early anticoagulation prevents ischemic recurrence but with the risk of hemorrhagic transformation (HT). The aims of this study were to evaluate in consecutive patients with acute stroke and atrial fibrillation (1) the incidence of early HT, (2) the time to initiation of anticoagulation in patients with HT, (3) the association of HT with ischemic recurrences, and (4) the association of HT with clinical outcome at 90 days. Methods and Results: HT was diagnosed by a second brain computed tomographic scan performed 24 to 72 hours after stroke onset. The incidence of ischemic recurrences as well as mortality or disability (modified Rankin Scale scores >2) were evaluated at 90 days. Ischemic recurrences were the composite of ischemic stroke, transient ischemic attack, or systemic embolism. Among the 2183 patients included in the study, 241 (11.0%) had HT. Patients with and without HT initiated anticoagulant therapy after a mean 23.3 and 11.6 days, respectively, from index stroke. At 90 days, 4.6% (95% confidence interval, 2.3–8.0) of the patients with HT had ischemic recurrences compared with 4.9% (95% confidence interval, 4.0–6.0) of those without HT; 53.1% of patients with HT were deceased or disabled compared with 35.8% of those without HT. On multivariable analysis, HT was associated with mortality or disability (odds ratio, 1.71; 95% confidence interval, 1.24–2.35). Conclusions: In patients with HT, anticoagulation was initiated about 12 days later than patients without HT. This delay was not associated with increased detection of ischemic recurrence. HT was associated with increased mortality or disability

Anticoagulation After Stroke in Patients With Atrial Fibrillation : To Bridge or Not With Low-Molecular-Weight Heparin?

Background and Purpose- Bridging therapy with low-molecular-weight heparin reportedly leads to a worse outcome for acute cardioembolic stroke patients because of a higher incidence of intracerebral bleeding. However, this practice is common in clinical settings. This observational study aimed to compare (1) the clinical profiles of patients receiving and not receiving bridging therapy, (2) overall group outcomes, and (3) outcomes according to the type of anticoagulant prescribed. Methods- We analyzed data of patients from the prospective RAF and RAF-NOACs studies. The primary outcome was defined as the composite of ischemic stroke, transient ischemic attack, systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding observed at 90 days after the acute stroke. Results- Of 1810 patients who initiated oral anticoagulant therapy, 371 (20%) underwent bridging therapy with full-dose low-molecular-weight heparin. Older age and the presence of leukoaraiosis were inversely correlated with the use of bridging therapy. Forty-two bridged patients (11.3%) reached the combined outcome versus 72 (5.0%) of the nonbridged patients (P=0.0001). At multivariable analysis, bridging therapy was associated with the composite end point (odds ratio, 2.3; 95% CI, 1.4-3.7; P Conclusions- Our findings suggest that patients receiving low-molecular-weight heparin have a higher risk of early ischemic recurrence and hemorrhagic transformation compared with nonbridged patients.Peer reviewe

Prestroke CHA(2)DS(2)-VASc Score and Severity of Acute Stroke in Patients with Atrial Fibrillation : Findings from RAF Study

Background and Purpose: The aim of this study was to investigate for a possible association between both prestroke CHA(2)DS(2)-VASc score and the severity of stroke at presentation, as well as disability and mortality at 90 days, in patients with acute stroke and atrial fibrillation (AF). Methods: This prospective study enrolled consecutive patients with acute ischemic stroke, AF, and assessment of prestroke CHA2DS2-VASc score. Severity of stroke was assessed on admission using the National Institutes of Health Stroke Scale (NIHSS) score (severe stroke: NIHSS >= 10). Disability and mortality at 90 days were assessed by the modified Rankin Scale (mRS = 3). Multiple logistic regression was used to correlate prestroke CHA(2)DS(2)-VASc and severity of stroke, as well as disability and mortality at 90 days. Results: Of the 1020 patients included in the analysis, 606 patients had an admission NIHSS score lower and 414 patients higher than 10. At 90 days, 510 patients had mRS >= 3. A linear correlation was found between the prestroke CHA(2)DS(2)-VASc score and severity of stroke (P = .001). On multivariate analysis, CHA(2)DS(2)-VASc score correlated with severity of stroke (P = .041) and adverse functional outcome (mRS = 3) (P = .001). A logistic regression with the receiver operating characteristic graph procedure (C-statistics) evidenced an area under the curve of .60 (P = .0001) for severe stroke. Furthermore, a correlation was found between prestroke CHA(2)DS(2)-VASc score and lesion size. Conclusions: In patients with AF, in addition to the risk of stroke, a high CHA(2)DS(2)-VASc score was independently associated with both stroke severity at onset and disability and mortality at 90 days.Peer reviewe

The age and genomic integrity of neurons after cortical stroke in humans

L