462 research outputs found

    Visit-to-Visit Blood Pressure Variability and Sleep Architecture

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    Visitā€toā€visit blood pressure (BP) variability (BPV) is an independent risk factor of cardiovascular disease (CVD). Sleep architecture characterizes the distribution of different stages of sleep and may be important in CVD development. We examined the association between visitā€toā€visit BPV and sleep architecture using inā€lab polysomnographic data from 3,565 patients referred to an academic sleep center. BPV was calculated using the intraā€individual coefficient of variation of BP measures collected 12 months before the sleep study. We conducted multiple linear regression analyses to assess the association of systolic and diastolic BPV with sleep architectureā€”rapid eye movement (REM) and nonā€rapid eye movement (NREM) sleep duration. Our results show that systolic BPV was inversely associated with REM sleep duration (p = .058). When patients were divided into tertile groups based on their BPV, those in the third tertile (highest variability) spent 2.7 fewer minutes in REM sleep than those in the first tertile (lowest variability, p = .032), after adjusting for covariates. We did not find an association of systolic BPV with other measures of sleep architecture. Diastolic BPV was not associated with sleep architecture either. In summary, our study showed that greater systolic BPV was associated with lower REM sleep duration. Future investigation is warranted to clarify the directionality, mechanism, and therapeutic implications

    Reflection phase microscopy using spatio-temporal coherence of light

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    Many disease states are associated with cellular biomechanical changes as markers. Label-free phase microscopes are used to quantify thermally driven interface fluctuations, which allow the deduction of important cellular rheological properties. Here, the spatio-temporal coherence of light was used to implement a high-speed reflection phase microscope with superior depth selectivity and higher phase sensitivity. Nanometric scale motion of cytoplasmic structures can be visualized with fine details and three-dimensional resolution. Specifically, the spontaneous fluctuation occurring on the nuclear membrane of a living cell was observed at video rate. By converting the reflection phase into displacement, the sensitivity in quantifying nuclear membrane fluctuation was found to be about one nanometer. A reflection phase microscope can potentially elucidate biomechanical mechanisms of pathological and physiological processes.Korea Health Industry Development Institute. Korea Health Technology R&D Project (H114C3477)National Research Foundation of Korea (1R01HL121386-01A1)National Research Foundation of Korea (4R44EB012415)National Research Foundation of Korea (5R01NS051320)National Research Foundation of Korea (9P41EB015871-26A1)National Science Foundation (U.S.) (CBET-0939511)Hamamatsu CorporationSingapore-MIT Alliance. BioSystems and Micromechanics (BioSyM) Inter-Disciplinary Research GroupKorea University (Future Research Grant

    Pengaruh Tingkat Inflasi, Tingkat Suku Bunga SBI, Nilai Tukar Rupiah, Indeks Dow Jones, Dan Indeks Klse Terhadap Indeks Harga Saham Gabungan (Ihsg) Studi Pada Bursa Efek Indonesia Periode Januari 2010 ā€“ Desember 2013

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    This research aimed to know the effect of inflation rate, SBI rate, Rupiah exchange rate, Dow Jones index, KLSE index towards Composite Stock Price Index (CSPI). Types of research used in explanatory research with quantitative approach. The sample was based on monthly time series data from January 2010 - December 2013, used full sampling method which consist of 48 samples. This research used multiple linear regression method. The value coefficient of determination (R2) 0,84, means the independent variables inflation rate, SBI rate, Rupiah exchange rate, Dow Jones index, KLSE index, explain the dependent variable Composite Stock Price Index (CSPI) up to 84% and the remaining 16% explained by the other that had not been examined. Simultaneous test result (F test), indicating that inflation rate, SBI rate, Rupiah exchange rate, Dow Jones index, KLSE index has significant effect on the Composite Stock Price Index (CSPI) simultaneously. Partial test result (t test), indicates that inflation rate showed a insignificant influence on CSPI, while SBI rate and Rupiah exchange rate had a negative effect and significant to CSPI, Dow Jones index and KLSE index had a positive and significant to CSPI. The most dominant influential variable in this research is Dow Jones Index

    Analog Self-Interference Cancellation With Practical RF Components for Full-Duplex Radios

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    One of the main obstacles in full-duplex radios is analog-to-digital converter (ADC) saturation on a receiver due to the strong self-interference (SI). To solve this issue, researchers have proposed two different types of analog self-interference cancellation (SIC) methodsā€”i) passive suppression and ii) regeneration-and-subtraction of SI. For the latter case, the tunable RF component, such as a multi-tap circuit, reproduces and subtracts the SI. The resolutions of such RF components constitute the key factor of the analog SIC. Indeed, they are directly related to how well the SI is imitated. Another major issue in analog SIC is the inaccurate estimation of the SI channel due to the nonlinear distortions, which mainly come from the power amplifier (PA). In this paper, we derive a closed-form expression for the SIC performance of the multi-tap circuit; we consider how the RF components must overcome such practical impairments as digitally-controlled attenuators, phase shifters, and PA. For a realistic performance analysis, we exploit the measured PA characteristics and carry out a 3D ray-tracing-based, system-level throughput analysis. Our results confirm that the non-idealities of the RF components significantly affect the analog SIC performance. We believe our study provides insight into the design of the practical full-duplex system

    Stress-induced Cardiomyopathy during Pulmonary Resection (Takotsubo Syndrome) - A case report -

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    Stress-induced cardiomyopathy is caused by emotional or physical stressors and mimics acute myocardial infarction, though Stress-induced cardiomyopathy is characterized by reversible left ventricular (LV) apical ballooning in the absence of significant coronary artery disease. We describe a 51-year-old male who underwent left upper lobectomy for non-small cell lung cancer, and during which cardiogenic arrest occurred due to stress-induced cardiomyopathy, successfully managed by intra-aortic balloon pumping and extracorporeal membrane oxygenation

    An Isolated True Aneurysm of the Superficial Femoral Artery in a Young Woman - A case report -

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    A 39-year-old woman was admitted to the hospital due to a pulsatile mass on her right inner thigh that was evident for two months. She did not exhibit any risk factors of atherosclerosis, no evidence of vasculitis, or any signs of previous trauma history. Ultrasound and computed tomography revealed an adult fist-sized aneurysm on the distal superficial femoral artery. The aneurysm was resected and peripheral circulation was restored with the interposition of a saphenous vein graft. The resected aneurysm had three layers that showed atherosclerosis on histological examination

    Clinical implementation of whole-genome array CGH as a first-tier test in 5080 pre and postnatal cases

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    <p>Abstract</p> <p>Background</p> <p>Array comparative genomic hybridization (CGH) is currently the most powerful method for detecting chromosomal alterations in pre and postnatal clinical cases. In this study, we developed a BAC based array CGH analysis platform for detecting whole genome DNA copy number changes including specific micro deletion and duplication chromosomal disorders. Additionally, we report our experience with the clinical implementation of our array CGH analysis platform. Array CGH was performed on 5080 pre and postnatal clinical samples from patients referred with a variety of clinical phenotypes.</p> <p>Results</p> <p>A total of 4073 prenatal cases (4033 amniotic fluid and 40 chorionic villi specimens) and 1007 postnatal cases (407 peripheral blood and 600 cord blood) were studied with complete concordance between array CGH, karyotype and fluorescence <it>in situ </it>hybridization results. Among 75 positive prenatal cases with DNA copy number variations, 60 had an aneuploidy, seven had a deletion, and eight had a duplication. Among 39 positive postnatal cases samples, five had an aneuploidy, 23 had a deletion, and 11 had a duplication.</p> <p>Conclusions</p> <p>This study demonstrates the utility of using our newly developed whole-genome array CGH as first-tier test in 5080 pre and postnatal cases. Array CGH has increased the ability to detect segmental deletion and duplication in patients with variable clinical features and is becoming a more powerful tool in pre and postnatal diagnostics.</p
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