3,165 research outputs found
No electromagnetic interference exists between the new remote monitoring system and implantable devices
INTRODUCTION: The BodyGuardian® is a novel remote monitoring platform comprised of a rechargeable module that attaches to an adhesive patch with attached electrodes. ECG, respiration, activity level and other clinical parameters are transmitted via Bluetooth to a smartphone and then to the central cloud platform via cellular or Wi-Fi connection for clinical review (Figure). Although approved for clinical use, potential electromagnetic interference (EMI) precludes its use among patients with implantable ...postprin
Irradiation of Materials with Short, Intense Ion pulses at NDCX-II
We present an overview of the performance of the Neutralized Drift
Compression Experiment-II (NDCX-II) accelerator at Berkeley Lab, and report on
recent target experiments on beam driven melting and transmission ion energy
loss measurements with nanosecond and millimeter-scale ion beam pulses and thin
tin foils. Bunches with around 10^11 ions, 1-mm radius, and 2-30 ns FWHM
duration have been created with corresponding fluences in the range of 0.1 to
0.7 J/cm^2. To achieve these short pulse durations and mm-scale focal spot
radii, the 1.1 MeV He+ ion beam is neutralized in a drift compression section,
which removes the space charge defocusing effect during final compression and
focusing. The beam space charge and drift compression techniques resemble
necessary beam conditions and manipulations in heavy ion inertial fusion
accelerators. Quantitative comparison of detailed particle-in-cell simulations
with the experiment play an important role in optimizing accelerator
performance.Comment: 15 pages, 7 figures. revised manuscript submitted to Laser and
Particle Beam
Canonical and noncanonical sites determine NPT2A binding selectivity to NHERF1 PDZ1
Na+/H+ Exchanger Regulatory Factor-1 (NHERF1) is a scaffolding protein containing 2 PDZ domains that coordinates the assembly and trafficking of transmembrane receptors and ion channels. Most target proteins harboring a C-terminus recognition motif bind more-or-less equivalently to the either PDZ domain, which contain identical core-binding motifs. However some substrates such as the type II sodium-dependent phosphate co-transporter (NPT2A), uniquely bind only one PDZ domain. We sought to define the structural determinants responsible for the specificity of interaction between NHERF1 PDZ domains and NPT2A. By performing all-atom/explicit-solvent molecular dynamics (MD) simulations in combination with biological mutagenesis, fluorescent polarization (FP) binding assays, and isothermal titration calorimetry (ITC), we found that in addition to canonical interactions of residues at 0 and -2 positions, Arg at the -1 position of NPT2A plays a critical role in association with Glu43 and His27 of PDZ1 that are absent in PDZ2. Experimentally introduced mutation in PDZ1 (Glu43Asp and His27Asn) decreased binding to NPT2A. Conversely, introduction of Asp183Glu and Asn167His mutations in PDZ2 promoted the formation of favorable interactions yielding micromolar KDs. The results describe novel determinants within both the PDZ domain and outside the canonical PDZ-recognition motif that are responsible for discrimination of NPT2A between two PDZ domains. The results challenge general paradigms for PDZ recognition and suggest new targets for drug development
Does self-monitoring reduce blood pressure? Meta-analysis with meta-regression of randomized controlled trials
Introduction. Self-monitoring of blood pressure (BP) is an increasingly common part of hypertension management. The objectives of this systematic review were to evaluate the systolic and diastolic BP reduction, and achievement of target BP, associated with self-monitoring.
Methods. MEDLINE, Embase, Cochrane database of systematic reviews, database of abstracts of clinical effectiveness, the health technology assessment database, the NHS economic evaluation database, and the TRIP database were searched for studies where the intervention included self-monitoring of BP and the outcome was change in office/ambulatory BP or proportion with controlled BP. Two reviewers independently extracted data. Meta-analysis using a random effects model was combined with meta-regression to investigate heterogeneity in effect sizes.
Results. A total of 25 eligible randomized controlled trials (RCTs) (27 comparisons) were identified. Office systolic BP (20 RCTs, 21 comparisons, 5,898 patients) and diastolic BP (23 RCTs, 25 comparisons, 6,038 patients) were significantly reduced in those who self-monitored compared to usual care (weighted mean difference (WMD) systolic −3.82 mmHg (95% confidence interval −5.61 to −2.03), diastolic −1.45 mmHg (−1.95 to −0.94)). Self-monitoring increased the chance of meeting office BP targets (12 RCTs, 13 comparisons, 2,260 patients, relative risk = 1.09 (1.02 to 1.16)). There was significant heterogeneity between studies for all three comparisons, which could be partially accounted for by the use of additional co-interventions.
Conclusion. Self-monitoring reduces blood pressure by a small but significant amount. Meta-regression could only account for part of the observed heterogeneity
Studying accelerated cardiovascular ageing in Russian adults through a novel deep-learning ECG biomarker [version 1; peer review: awaiting peer review]
Background: A non-invasive, easy-to-access marker of accelerated cardiac ageing would provide novel insights into the mechanisms and aetiology of cardiovascular disease (CVD) as well as contribute to risk stratification of those who have not had a heart or circulatory event. Our hypothesis is that differences between an ECG-predicted and chronologic age of participants (δage) would reflect accelerated or decelerated cardiovascular ageing.
Methods: A convolutional neural network model trained on over 700,000 ECGs from the Mayo Clinic in the U.S.A was used to predict the age of 4,542 participants in the Know Your Heart study conducted in two cities in Russia (2015-2018). Thereafter, δage was used in linear regression models to assess associations with known CVD risk factors and markers of cardiac abnormalities. /
Results: The biomarker δage (mean: +5.32 years) was strongly and positively associated with established risk factors for CVD: blood pressure, body mass index (BMI), total cholesterol and smoking. Additionally, δage had strong independent positive associations with markers of structural cardiac abnormalities: N-terminal pro b-type natriuretic peptide (NT-proBNP), high sensitivity cardiac troponin T (hs-cTnT) and pulse wave velocity, a valid marker of vascular ageing. /
Conclusion: The difference between the ECG-age obtained from a convolutional neural network and chronologic age (δage) contains information about the level of exposure of an individual to established CVD risk factors and to markers of cardiac damage in a way that is consistent with it being a biomarker of accelerated cardiovascular (vascular) ageing. Further research is needed to explore whether these associations are seen in populations with different risks of CVD events, and to better understand the underlying mechanisms involved
Arrhythmogenic substrates ablated at the aortomitral continuity - potential involvement of the conduction system
Core 4. Heart Rhythm Disorders and Resuscitation Science - Session Title: Ablation Therapy for Ventricular TachycardiaOpen Access JournalBACKGROUND: Although successful ablation of ventricular arrhythmias (VA) at the aortomitral continuity (AMC) has been described, arrhythmogenic substrates at this fibrous region remain undefined. We sought to characterize the electrophysiological properties of arrhythmogenic substrates involved in these arrhythmias ...postprin
Effect of Cyclooxygenase(COX)-1 and COX-2 inhibition on furosemide-induced renal responses and isoform immunolocalization in the healthy cat kidney
BACKGROUND: The role of cyclooxygenase(COX)-1 and COX-2 in the saluretic and renin-angiotensin responses to loop diuretics in the cat is unknown. We propose in vivo characterisation of isoform roles in a furosemide model by administering non-steroidal anti-inflammatory drugs (NSAIDs) with differing selectivity profiles: robenacoxib (COX-2 selective) and ketoprofen (COX-1 selective). RESULTS: In this four period crossover study, we compared the effect of four treatments: placebo, robenacoxib once or twice daily and ketoprofen once daily concomitantly with furosemide in seven healthy cats. For each period, urine and blood samples were collected at baseline and within 48 h of treatment starting. Plasma renin activity (PRA), plasma and urinary aldosterone concentrations, glomerular filtration rate (GFR) and 24 h urinary volumes, electrolytes and eicosanoids (PGE(2), 6-keto-PGF1(α,) TxB(2)), renal injury biomarker excretions [N-acetyl-beta-D-glucosaminidase (NAG) and Gamma-Glutamyltransferase] were measured. Urine volume (24 h) and urinary sodium, chloride and calcium excretions increased from baseline with all treatments. Plasma creatinine increased with all treatments except placebo, whereas GFR was significantly decreased from baseline only with ketoprofen. PRA increased significantly with placebo and once daily robenacoxib and the increase was significantly higher with placebo compared to ketoprofen (10.5 ± 4.4 vs 4.9 ± 5.0 ng ml(−1) h(−1)). Urinary aldosterone excretion increased with all treatments but this increase was inhibited by 75 % with ketoprofen and 65 % with once daily robenacoxib compared to placebo. Urinary PGE(2) excretion decreased with all treatments and excretion was significantly lower with ketoprofen compared to placebo. Urinary TxB(2) excretion was significantly increased from baseline only with placebo. NAG increased from baseline with all treatments. Immunohistochemistry on post-mortem renal specimens, obtained from a different group of cats that died naturally of non-renal causes, suggested constitutive COX-1 and COX-2 co-localization in many renal structures including the macula densa (MD). CONCLUSIONS: These data suggest that both COX-1 and COX-2 could generate the signal from the MD to the renin secreting cells in cats exposed to furosemide. Co-localization of COX isoenzymes in MD cells supports the functional data reported here. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0598-z) contains supplementary material, which is available to authorized users
Multilevel Deconstruction of the In Vivo Behavior of Looped DNA-Protein Complexes
Protein-DNA complexes with loops play a fundamental role in a wide variety of
cellular processes, ranging from the regulation of DNA transcription to
telomere maintenance. As ubiquitous as they are, their precise in vivo
properties and their integration into the cellular function still remain
largely unexplored. Here, we present a multilevel approach that efficiently
connects in both directions molecular properties with cell physiology and use
it to characterize the molecular properties of the looped DNA-lac repressor
complex while functioning in vivo. The properties we uncover include the
presence of two representative conformations of the complex, the stabilization
of one conformation by DNA architectural proteins, and precise values of the
underlying twisting elastic constants and bending free energies. Incorporation
of all this molecular information into gene-regulation models reveals an
unprecedented versatility of looped DNA-protein complexes at shaping the
properties of gene expression.Comment: Open Access article available at
http://www.plosone.org/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1371%2Fjournal.pone.000035
The SNAPSHOT study protocol : SNAcking, Physical activity, Self-regulation, and Heart rate Over Time
Peer reviewedPublisher PD
Maximal Spontaneous Photon Emission and Energy Loss from Free Electrons
Free electron radiation such as Cerenkov, Smith--Purcell, and transition
radiation can be greatly affected by structured optical environments, as has
been demonstrated in a variety of polaritonic, photonic-crystal, and
metamaterial systems. However, the amount of radiation that can ultimately be
extracted from free electrons near an arbitrary material structure has remained
elusive. Here we derive a fundamental upper limit to the spontaneous photon
emission and energy loss of free electrons, regardless of geometry, which
illuminates the effects of material properties and electron velocities. We
obtain experimental evidence for our theory with quantitative measurements of
Smith--Purcell radiation. Our framework allows us to make two predictions. One
is a new regime of radiation operation---at subwavelength separations, slower
(nonrelativistic) electrons can achieve stronger radiation than fast
(relativistic) electrons. The second is a divergence of the emission
probability in the limit of lossless materials. We further reveal that such
divergences can be approached by coupling free electrons to photonic bound
states in the continuum (BICs). Our findings suggest that compact and efficient
free-electron radiation sources from microwaves to the soft X-ray regime may be
achievable without requiring ultrahigh accelerating voltages.Comment: 7 pages, 4 figure
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