406 research outputs found
Prestressed concrete penstock design for water hammer
Thesis (Civ. E.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1953.Includes bibliographical references (leaf 38).by Rajnikant Jayachand Kumbhani.Civ.E
Secrecy of WSN Data Over Nakagami m Fading Channels with Selection Combining Diversity
We consider the security of wireless sensor network (WSN) data over Nakagami – m fading channels at the physical layer. A WSN in which the fusion center performs selection diversity has been considered for better quality reception. The links between the WSN node and fusion center are assumed to follow Nakagami-m fading distribution. Closed-form expressions for secrecy outage probability (SOP) are derived, and it is established that SOP analysis also leads to the analysis of the existence of secrecy as a special case of SOP. The analytical expressions have been validated through results from simulations. The analysis is valid for all positive real values of the fading parameter, m. The limits on the signal-to-noise ratio can be obtained to secure the transmitted data against eavesdropping with the required SOP and secrecy rate using the analysis presented in this paper
Mechanical Thrombectomy for Acute Ischemic Stroke A Meta-Analysis of Randomized Trials
AbstractBackgroundAcute ischemic stroke is a leading cause of serious disability and death worldwide. Individual randomized trials have shown possible benefits of mechanical thrombectomy after usual care compared with usual care alone (i.e., intravenous thrombolysis) in the management of acute ischemic stroke patients.ObjectivesThis study systematically determined if mechanical thrombectomy after usual care would be associated with better outcomes in patients with acute ischemic stroke caused by large artery occlusion.MethodsThe authors included randomized trials that compared mechanical thrombectomy after usual care versus usual care alone for acute ischemic stroke. Random effects summary risk ratios (RR) were constructed using a DerSimonian and Laird model.ResultsNine trials with 2,410 patients were available for analysis. Compared with usual care alone, mechanical thrombectomy was associated with a higher incidence of achieving good functional outcome, defined as a modified Rankin scale (mRS) of 0 to 2 (RR: 1.45; 95% confidence interval [CI]: 1.22 to 1.72; p < 0.0001) and excellent functional outcome defined as mRS 0 to 1 (RR: 1.67; 95% CI: 1.27 to 2.19; p < 0.0001) at 90 days. There was a trend toward reduced all-cause mortality with mechanical thrombectomy (RR: 0.86; 95% CI: 0.72 to 1.02; p = 0.09). The risk of symptomatic intracranial hemorrhage was similar with either treatment modality (RR 1.06: 95% CI: 0.73 to 1.55; p = 0.76).ConclusionsIn acute ischemic stroke due to large artery occlusion, mechanical thrombectomy after usual care was associated with improved functional outcomes compared with usual care alone, and was found to be relatively safe, with no excess in intracranial hemorrhage. There was a trend for reduction in all-cause mortality with mechanical thrombectomy
CRT-710 Associations Of Known Complications With Transcatheter Implantation Of First-generation Self Expandable Corevalve Aortic Valves With Peri-procedural Mortality-an Insight From Reports From The FDA Maude Database
Predictors of Long‐term Adherence to Evidence‐based Cardiovascular Disease Medications in Outpatients With Stable Atherothrombotic Disease: Findings From the REACH Registry
Background Despite overall improvements in cardiovascular‐disease therapies and outcomes, medication nonadherence remains an important barrier to effective secondary prevention of atherothrombotic disease. Hypothesis Long‐term medication adherence in outpatients with stable atherothrombotic disease is impacted by demographic and clinical factors. Methods We examined data from the prospective international Reduction of Atherothrombosis for Continued Health ( REACH ) Registry. Analyses were derived from 25 737 patients with established atherothrombotic disease with complete adherence data at enrollment and at year 4. Adherence was defined as patients' self‐report of taking medications based on class I American College of Cardiology/American Heart Association guidelines for secondary prevention as defined, including antiplatelet agents, statins, and antihypertensive medications. Results Among patients with atherothrombotic disease, 12 500 (48.6%) were deemed adherent to guideline‐recommended medications. Adherent patients were younger, white, and had less polyvascular disease. Hispanic and East Asian patients were less likely to be adherent as compared with white patients (odds ratio [ OR ]: 0.72, 95% confidence interval [ CI ]: 0.59‐0.88; and OR : 0.67, 95% CI : 0.53‐0.83, respectively). Patients who had a nonfatal MI or underwent coronary angioplasty/stenting during follow‐up were more likely to be adherent compared with patients without these events ( OR : 1.73, 95% CI : 1.25‐2.38; and OR : 2.15, 95% CI : 1.72‐2.67, respectively). On the other hand, nonfatal stroke during follow‐up was inversely associated with adherence ( OR : 0.77, 95% CI : 0.61‐0.97). Conclusions Using a large international registry of outpatients with atherothrombotic disease, we found that age, region, race/ethnicity, and incident cardiovascular events were predictive of long‐term guideline adherence for secondary prevention, suggesting that certain patient groups may benefit from targeted interventions to improve adherence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102180/1/clc22217.pd
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Simple Integer Risk Score to Determine Prognosis of Patients With Hypertension and Chronic Stable Coronary Artery Disease
Background: It is difficult to accurately determine prognosis of patients with hypertension and chronic stable coronary artery disease (CAD). Our aim was to construct a risk score for predicting important adverse events in this population. Methods and Results: Patients with hypertension and chronic stable CAD enrolled in the INternational VErapamil‐SR/Trandolapril STudy (INVEST) comprised the study cohort. Candidate predictor variables were obtained from patients with at least 1 postbaseline visit. Patients were divided into development (n=18 484) and validation cohorts (n=2054). Cox regression model identified predictors of the primary outcome: all‐cause mortality, myocardial infarction, or stroke at a mean follow‐up of 2.3 years. The hazard ratio of each variable was rounded to the nearest integer to construct score weights. A score 0 to 4 defined low‐risk, 5 to 6 intermediate‐risk and ≥7 high‐risk. The following variables were retained in the final model: age, residence, body mass index, on‐treatment heart rate and BP, prior myocardial infarction, heart failure, stroke/transient ischemic attack, smoking, diabetes, peripheral arterial disease, and chronic kidney disease. The primary outcome occurred in 2.9% of the low‐risk group, 6.5% of the intermediate‐risk group, and 18.0% of the high‐risk group (P for trend <0.0001). The model was good at discriminating those who had an event versus those who did not (C‐statistic=0.75). The model performed well in a validation cohort (C‐statistic=0.77). Conclusion: Readily available clinical variables can rapidly stratify patients with hypertension and chronic stable CAD into useful risk categories
Benefit of Early Invasive Therapy in Acute Coronary Syndromes A Meta-Analysis of Contemporary Randomized Clinical Trials
ObjectivesThis study sought to systematically determine whether early invasive therapy improves survival and reduces adverse cardiovascular events in the management of non–ST-segment elevation acute coronary syndromes.BackgroundAlthough early invasive therapy reduces recurrent unstable angina, the magnitude of benefit on other important adverse outcomes is unknown.MethodsClinical trials that randomized non–ST-segment elevation acute coronary syndrome patients to early invasive therapy versus a more conservative approach were included for analysis.ResultsIn all there were 7 trials with 8,375 patients available for analysis. At a mean follow-up of 2 years, the incidence of all-cause mortality was 4.9% in the early invasive group, compared with 6.5% in the conservative group (risk ratio [RR] = 0.75, 95% confidence interval [CI] 0.63 to 0.90, p = 0.001), and at 1 month (RR = 0.82, 95% CI 0.50 to 1.34, p = 0.43). At 2 years of follow-up, the incidence of nonfatal myocardial infarction was 7.6% in the invasive group, versus 9.1% in the conservative group (RR = 0.83, 95% CI 0.72 to 0.96, p = 0.012), and at 1 month (RR = 0.93, 95% CI 0.73 to 1.19, p = 0.57). At a mean of 13 months of follow-up, there was a reduction in rehospitalization for unstable angina (RR = 0.69, 95% CI 0.65 to 0.74, p < 0.0001).ConclusionsManaging non–ST-segment elevation acute coronary syndromes by early invasive therapy improves long-term survival and reduces late myocardial infarction and rehospitalization for unstable angina
The information transmitted by spike patterns in single neurons
Spike patterns have been reported to encode sensory information in several
brain areas. Here we assess the role of specific patterns in the neural code,
by comparing the amount of information transmitted with different choices of
the readout neural alphabet. This allows us to rank several alternative
alphabets depending on the amount of information that can be extracted from
them. One can thereby identify the specific patterns that constitute the most
prominent ingredients of the code. We finally discuss the interplay of
categorical and temporal information in the amount of synergy or redundancy in
the neural code.Comment: To be published in Journal of Physiology Paris 200
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