1,448 research outputs found

    Echocardiographic characterization of heart failure

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    Heart failure is a highly prevalent disease. In failure, the pump function of the heart is insufficient, leading to symptoms such as shortness of breath and fluid retention. Echocardiography is commonly used to diagnose heart failure. Echocardiography can be used to determine the ejection fraction. Every beat, the heart is filled with blood. The percentage of blood that gets ejected every beat is called the ejection fraction. Ejection fraction is around 60% in healthy people. From literature, we know that patients with an ejection fraction below 40% will benefit from medical therapy, and sometimes device therapy of the heart. However, some patients with symptoms of heart failure have an ejection fraction above 40%. So far, no treatments have been shown effective in this group of patients. The aims of this thesis were to further characterize patients with an ejection fraction above 40%, especially those with a ‘mildly reduced’ or ‘mid-range’ ejection fraction of 40-50%. In addition, we examined the value of additional echocardiographic parameters for the diagnosis of heart failure. We found that evidence is starting to accumulate that patients with a mildly reduced ejection fraction benefit from medical therapy as well. Even after comprehensive echocardiographic examination, the diagnosis of heart failure with a preserved ejection fraction often remains uncertain. Finally, we found that in patients with a reduced ejection fraction, those with dilated left ventricles seem to benefit most from medical therapy

    A 1.2V 10μW NPN-Based Temperature Sensor in 65nm CMOS with an inaccuracy of ±0.2°C (3s) from −70°C to 125°C

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    This paper describes a temperature sensor realized in a 65nm CMOS process with a batch-calibrated inaccuracy of ±0.5°C (3σ) and a trimmed inaccuracy of ±0.2°C (3σ) from –70°C to 125°C. This represents a 10-fold improvement in accuracy compared to other deep-submicron temperature sensors [1,2], and is comparable with that of state-of-the-art sensors implemented in larger-featuresize processes [3,4]. The sensor draws 8.3μA from a 1.2V supply and occupies an area of 0.1mm2, which is 45 times less than that of sensors with comparable accuracy [3,4]. These advances are enabled by the use of NPN transistors as sensing elements, the use of dynamic techniques i.e. correlated double sampling (CDS) and dynamic element matching (DEM), and a single room-temperature trim

    A 2.4GHz 830pJ/bit duty-cycled wake-up receiver with −82dBm sensitivity for crystal-less wireless sensor nodes

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    A 65 nm CMOS 2.4 GHz wake-up receiver operating with low-accuracy frequency references has been realized. Robustness to frequency inaccuracy is achieved by employing non-coherent energy detection, broadband-IF heterodyne architecture and impulse-radio modulation. The radio dissipates 415 ¿W at 500 kb/s and achieves a sensitivity of -82 dBm with an energy efficiency of 830 pJ/bit.\u

    Guided Act and Feel Indonesia (GAF-ID) – Internet-based behavioral activation intervention for depression in Indonesia: study protocol for a randomized controlled trial

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    Background: Depression is a leading cause of disease burden across the world. However, in low-middle income countries (LMICs), access to mental health services is severely limited because of the insufficient number of mental health professionals available. The WHO initiated the Mental Health Gap Action Program (mhGAP) aiming to provide a coherent strategy for closing the gap between what is urgently needed and what is available in LMICs. Internet-based treatment is a promising strategy that can be made available to a large number of people now that Internet access is increasing rapidly throughout the world. The present study will investigate whether such an Internet-based treatment for depression is effective in Indonesia.  Methods: An Internet-based behavioral activation treatment, with support by lay counselors who will provide online feedback on the assignments and supportive phone contact to encourage participants to work in the program (Guided Act and Feel Indonesia/GAF-ID), is compared to an online-delivered minimal psychoeducation without any support (psychoeducation/PE). Initial assessment for inclusion is based on a Patient Health Questionnaire-9 (PHQ-9) score of at least 10 and meeting criteria for major depressive disorder or persistent depressive disorder as assessed using the Structured Clinical Interview for DSM-5 (SCID-5). Participants with depression (N=312) will be recruited and randomly assigned to GAF-ID or PE. Overall assessments will be done at baseline, post intervention (10 weeks from baseline) and follow-ups (3 months and 6 months from baseline). The primary outcome is the reduction of depression symptoms as measured by the PHQ-9 after 10 weeks from baseline.  Discussion: To our knowledge, this is the first study in Indonesia that examines the effectiveness of an Internet-based intervention for depression in a randomized controlled trial. The hope is that it can serve as a starting point for bridging the mental health gap in Indonesia and other LMICs. Trial registration: Nederlands Trial Register ( www.trialregister.nl ): NTR5920 , registered on 1 July 2016

    Low-Frequency Noise Phenomena in Switched MOSFETs

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    In small-area MOSFETs widely used in analog and RF circuit design, low-frequency (LF) noise behavior is increasingly dominated by single-electron effects. In this paper, the authors review the limitations of current compact noise models which do not model such single-electron effects. The authors present measurement results that illustrate typical LF noise behavior in small-area MOSFETs, and a model based on Shockley-Read-Hall statistics to explain the behavior. Finally, the authors treat practical examples that illustrate the relevance of these effects to analog circuit design. To the analog circuit designer, awareness of these single-electron noise phenomena is crucial if optimal circuits are to be designed, especially since the effects can aid in low-noise circuit design if used properly, while they may be detrimental to performance if inadvertently applie

    A 65nm CMOS 1-to-10GHz tunable continuous-time low-pass filter for high-data-rate communications

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    In this work the Gm-C topology is adopted for its merits at high frequencies. In this technique, two critical parameters should be accounted for: the accuracy of the Q factors of the pole pairs (for correct transfer function) and parasitic capacitances (for maximal cut-off frequency). The former point is influenced by the phase shift of the integrators compounding the filter in the neighborhood of the filter's edge frequency. This phase error is due to two antagonistic effects which are the integrator's finite DC gain and its high-frequency poles/zeros

    A superfluid hydrodynamic model for the enhanced moments of inertia of molecules in liquid 4He

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    We present a superfluid hydrodynamic model for the increase in moment of inertia, ΔI\Delta I, of molecules rotating in liquid 4^4He. The static inhomogeneous He density around each molecule (calculated using the Orsay-Paris liquid 4^4He density functional) is assumed to adiabatically follow the rotation of the molecule. We find that the ΔI\Delta I values created by the viscousless and irrotational flow are in good agreement with the observed increases for several molecules [ OCS, (HCN)2_2, HCCCN, and HCCCH3_3 ]. For HCN and HCCH, our model substantially overestimates ΔI\Delta I. This is likely to result from a (partial) breakdown of the adiabatic following approximation.Comment: 4 pages, 1 eps figure, corrected version of published paper. Erratum has been submitted for change

    Glucose Exposure in Peritoneal Dialysis Is a Significant Factor Predicting Peritonitis

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    INTRODUCTION: Loss of residual renal function (RRF) as well as high peritoneal glucose exposure are associated with increased peritonitis frequency in peritoneal dialysis (PD) patients. Our objective was to investigate the contribution of RRF and peritoneal glucose exposure to peritonitis in PD patients. METHODS: In this prospective longitudinal cohort study, 105 incident end-stage renal disease patients that started PD between January 2006 and 2015 were studied. Follow-up was 5 years with censoring at death or switch to another treatment modality. Cox regression models were used to calculate the association between glucose exposure, RRF, and peritonitis. Kaplan-Meier analysis was used to examine the difference in occurrence of peritonitis between patients with high and low glucose exposure and between those with and without residual diuresis. RESULTS: One hundred and five patients were followed for a mean of 23 months. Fifty-one patients developed a peritonitis. Cox regression models at 6 months showed that glucose exposure and not residual diuresis significantly predicted PD peritonitis. Kaplan-Meier analysis after 6 months of follow-up showed that time to first PD peritonitis was significantly longer in the low glucose exposure group. Similarly, patients with RRF had a significantly longer interval to first peritonitis compared to patients without RRF. CONCLUSION: A higher exposure to glucose rather than loss of RRF is associated with an increased risk of peritonitis. This confirms the detrimental effects of glycemic harm to the peritoneal host defense on invading microorganisms and argues for the use of the lowest PD glucose concentrations possible
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