bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Resolution Requirements for Accurate Identification of Drivers of Atrial Fibrillation
Authors: Roney Caroline H. , Cantwell Chris D. , Bayer Jason D. , Qureshi Norman A. , Lim Phang Boon , Tweedy Jennifer H. , Kanagaratnam Prapa , Peters Nicholas S. , Vigmond Edward J. , Ng Fu Siong 
Published: May 2017

Background—
Recent studies have demonstrated conflicting mechanisms underlying atrial fibrillation (AF), with the spatial resolution of data often cited as a potential reason for the disagreement. The purpose of this study was to investigate whether the variation in spatial resolution of mapping may lead to misinterpretation of the underlying mechanism in persistent AF.

Methods and Results—
Simulations of rotors and focal sources were performed to estimate the minimum number of recording points required to correctly identify the underlying AF mechanism. The effects of different data types (action potentials and unipolar or bipolar electrograms) and rotor stability on resolution requirements were investigated. We also determined the ability of clinically used endocardial catheters to identify AF mechanisms using clinically recorded and simulated data. The spatial resolution required for correct identification of rotors and focal sources is a linear function of spatial wavelength (the distance between wavefronts) of the arrhythmia. Rotor localization errors are larger for electrogram data than for action potential data. Stationary rotors are more reliably identified compared with meandering trajectories, for any given spatial resolution. All clinical high-resolution multipolar catheters are of sufficient resolution to accurately detect and track rotors when placed over the rotor core although the low-resolution basket catheter is prone to false detections and may incorrectly identify rotors that are not present.

Conclusions—
The spatial resolution of AF data can significantly affect the interpretation of the underlying AF mechanism. Therefore, the interpretation of human AF data must be taken in the context of the spatial resolution of the recordings.
Electrical Substrate Elimination in 135 Consecutive Patients With Brugada Syndrome
Authors: Pappone Carlo , Brugada Josep , Vicedomini Gabriele , Ciconte Giuseppe , Manguso Francesco , Saviano Massimo , Vitale Raffaele , Cuko Amarild , Giannelli Luigi , Calovic Zarko , Conti Manuel , Pozzi Paolo , Natalizia Andrea , Crisà Simonetta , Borrelli Valeria , Brugada Ramon , Sarquella-Brugada Georgia , Guazzi Marco , Frigiola Alessandro , Menicanti Lorenzo , Santinelli Vincenzo 
Published: May 2017

Background—
There is emerging evidence that localization and elimination of abnormal electric activity in the epicardial right ventricular outflow tract may be beneficial in patients with Brugada syndrome.

Methods and Results—

A total of 135 symptomatic Brugada syndrome patients having implantable cardiac defibrillator were enrolled: 63 (group 1) having documented ventricular tachycardia (VT)/ventricular fibrillation (VF) and Brugada syndrome–related symptoms, and 72 (group 2) having inducible VT/VF without ECG documentation at the time of symptoms. About 27 patients of group 1 experienced multiple implantable cardiac defibrillator shocks for recurrent VT/VF episodes. Three-dimensional maps before and after ajmaline determined the arrhythmogenic electrophysiological substrate (AES) as characterized by prolonged fragmented ventricular potentials. Primary end point was identification and elimination of AES leading to ECG pattern normalization and VT/VF noninducibility. Extensive areas of AES were found in the right ventricle epicardium, which were wider in group 1 (
P
=0.007). AES increased after ajmaline in both groups (
P
<0.001) and was larger in men (
P
=0.008). The increase of type-1 ST-segment elevation correlated with AES expansion (
r
=0.682,
P
<0.001). Radiofrequency ablation eliminated AES leading to ECG normalization and VT/VF noninducibility in all patients. During a median follow-up of 10 months, the ECG remained normal even after ajmaline in all except 2 patients who underwent a repeated effective procedure for recurrent VF.

Conclusions—
In Brugada syndrome, AES is commonly located in the right ventricle epicardium and ajmaline exposes its extent and distribution, which is correlated with the degree of coved ST-elevation. AES elimination by radiofrequency ablation results in ECG normalization and VT/VF noninducibility. Substrate-based ablation is effective in potentially eliminating the arrhythmic consequences of this genetic disease.

Clinical Trial Registration—

URL:
https://clinicaltrials.gov
. Unique identifier: NCT02641431.
Antidepressants, Depression, and Venous Thromboembolism Risk: Large Prospective Study of UK Women
Authors: Parkin Lianne , Balkwill Angela , Sweetland Siân , Reeves Gillian K. , Green Jane , Beral Valerie , Abbiss Hayley , Abbott Simon , Alison Rupert , Armstrong Miranda , Baker Krys , Barnes Isobel , Black Judith , Blanks Roger , Bradbury Kathryn , Brown Anna , Cairns Benjamin , Canoy Dexter , Chadwick Andrew , Ewart Dave , Ewart Sarah , Fletcher Lee , Floud Sarah , Gathani Toral , Gerrard Laura , Goodill Adrian , Guiver Lynden , Heath Alicia , Hogg Darren , Hozak Michal , Lingard Isobel , Kan Sau Wan , Langston Nicky , Moser Kath , Pirie Kirstin , Price Alison , Reeves Gillian , Shaw Keith , Sherman Emma , Simpson Rachel , Strange Helena , Tipper Sarah , Travis Ruth , Trickett Lyndsey , Webster Anthony , Wotton Clare , Wright Lucy , Yang Owen , Young Heather , Carpenter Lucy , Dezateux Carol , Patnick Julietta , Peto Richard , Sudlow Cathie 
Published: May 2017

Background

Some investigators have reported an excess risk of venous thromboembolism (
VTE
) associated with depression and with use of antidepressant drugs. We explored these associations in a large prospective study of
UK
women.

Methods and Results

The Million Women Study recruited 1.3 million women through the National Health Service Breast Screening Programme in England and Scotland. Three years after recruitment, women were sent a second questionnaire that enquired about depression and regular use of medications in the previous 4 weeks. The present analysis included those who responded and did not have prior
VTE
, cancer, or recent surgery. Follow‐up for
VTE
was through linkage to routinely collected National Health Service statistics. Cox regression analyses yielded adjusted hazard ratios and 95%
CI
s. A total of 734 092 women (mean age 59.9 years) were included in the analysis; 6.9% reported use of antidepressants, 2.7% reported use of other psychotropic drugs, and 1.8% reported being treated for depression or anxiety but not use of psychotropic drugs. During follow‐up for an average of 7.3 years
,
3922 women were hospitalized for and/or died from
VTE
. Women who reported antidepressant use had a significantly higher risk of
VTE
than women who reported neither depression nor use of psychotropic drugs (hazard ratio, 1.39; 95%
CI
, 1.23–1.56).
VTE
risk was not significantly increased in women who reported being treated for depression or anxiety but no use of antidepressants or other psychotropic drugs (hazard ratio, 1.19; 95% CI, 0.95–1.49).

Conclusions

Use of antidepressants is common in
UK
women and is associated with an increased risk of
VTE
.
Impact of the Metabolic Syndrome on Mortality is Modified by Objective Short Sleep Duration
Authors: Fernandez‐Mendoza Julio , He Fan , LaGrotte Caitlin , Vgontzas Alexandros N. , Liao Duanping , Bixler Edward O. 
Published: May 2017

Background
To examine whether objective sleep duration is an effect modifier of the impact of metabolic syndrome (MetS) on all‐cause and cardiovascular disease/cerebrovascular mortality.

Methods and Results

We addressed this question in the Penn State Adult Cohort, a random, general population sample of 1344 men and women (48.8±14.2 years) who were studied in the sleep laboratory and followed up for 16.6±4.2 years. MetS was defined by the presence of 3 or more of obesity (≥30 kg/m
2
), elevated total cholesterol (≥200 mg/dL), triglycerides (≥150 mg/dL), fasting glucose (≥100 mg/dL), and blood pressure (≥130/85 mm Hg). Polysomnographic sleep duration was classified into clinically meaningful categories. Among the 1344 participants, 22.0% of them died during the follow‐up. We tested the interaction between MetS and polysomnographic sleep duration on mortality using Cox proportional hazard models controlling for multiple potential confounders (
P
<0.05). The hazard ratios (95%
CI
) of all‐cause and cardiovascular disease/cerebrovascular mortality associated with MetS were 1.29 (0.89–1.87) and 1.49 (0.75–2.97) for individuals who slept ≥6 hours and 1.99 (1.53–2.59) and 2.10 (1.39–3.16) for individuals who slept <6 hours. Interestingly, this effect modification was primarily driven by the elevated blood pressure and glucose dysregulation components of MetS.

Conclusions
The risk of mortality associated with MetS is increased in those with short sleep duration. Short sleep in individuals with MetS may be linked to greater central autonomic and metabolic dysfunction. Future clinical trials should examine whether lengthening sleep improves the prognosis of individuals with MetS.
Impact of Antihypertensive Treatment on Maternal and Perinatal Outcomes in Pregnancy Complicated by Chronic Hypertension: A Systematic Review and Meta‐Analysis
Authors: Webster Louise M. , Conti‐Ramsden Frances , Seed Paul T. , Webb Andrew J. , Nelson‐Piercy Catherine , Chappell Lucy C. 
Published: May 2017

Background
Chronic hypertension complicates around 3% of all pregnancies. There is evidence that treating severe hypertension reduces maternal morbidity. This study aimed to systematically review randomized controlled trials of antihypertensive agents treating chronic hypertension in pregnancy to determine the effect of this intervention.

Methods and Results

Medline (via
OVID
), Embase (via
OVID
) and the Cochrane Trials Register were searched from their earliest entries until November 30, 2016. All randomized controlled trials evaluating antihypertensive treatments for chronic hypertension in pregnancy were included. Data were extracted and analyzed in Stata (version 14.1). Fifteen randomized controlled trials (1166 women) were identified for meta‐analysis. A clinically important reduction in the incidence of severe hypertension was seen with antihypertensive treatment versus no antihypertensive treatment/placebo (5 studies, 446 women; risk ratio 0.33, 95%
CI
0.19‐0.56; I
2
0.0%). There was no difference in the incidence of superimposed pre‐eclampsia (7 studies, 727 women; risk ratio 0.74, 95%
CI
0.49‐1.11; I
2
28.1%), stillbirth/neonatal death (4 studies, 667 women; risk ratio 0.37, 95%
CI
0.11‐1.26; I
2
0.0%), birth weight (7 studies, 802 women; weighted mean difference −60 g, 95%
CI
−200 to 80 g; I
2
0.0%), or small for gestational age (4 studies, 369 women; risk ratio 1.01, 95%
CI
0.53‐1.94; I
2
0.0%) with antihypertensive treatment versus no treatment/placebo.

Conclusions
Antihypertensive treatment reduces the risk of severe hypertension in pregnant women with chronic hypertension. A considerable paucity of data exists to guide choice of antihypertensive agent. Adequately powered head‐to‐head randomized controlled trials of commonly used antihypertensive agents are required to inform prescribing.
Evolution of the Distribution of Upper-Tropospheric Humidity over the Indian Ocean: Connection with Large-Scale Advection and Local Cloudiness
Authors: Garot Thomas , Brogniez Hélène , Fallourd Renaud , Viltard Nicolas 
Published: May 2017

AbstractThe spatial and temporal distribution of upper-tropospheric humidity (UTH) observed by the Sounder for Atmospheric Profiling of Humidity in the Intertropics by Radiometry (SAPHIR)/Megha-Tropiques radiometer is analyzed over two subregions of the Indian Ocean during October–December over 2011–14. The properties of the distribution of UTH were studied with regard to the phase of the Madden–Julian oscillation (active or suppressed) and large-scale advection versus local production of moisture. To address these topics, first, a Lagrangian back-trajectory transport model was used to assess the role of the large-scale transport of air masses in the intraseasonal variability of UTH. Second, the temporal evolution of the distribution of UTH is analyzed using the computation of the higher moments of its probability distribution function (PDF) defined for each time step over the domain. The results highlight significant differences in the PDF of UTH depending on the phase of the MJO. The modeled trajectories ending in the considered domain originate from an area that strongly varies depending on the phases of the MJO: during the active phases, the air masses are spatially constrained within the tropical Indian Ocean domain, whereas a distinct upper-tropospheric (200–150 hPa) westerly flow guides the intraseasonal variability of UTH during the suppressed phases. Statistical relationships between the cloud fractions and the UTH PDF moments of are found to be very similar regardless of the convective activity. However, the occurrence of thin cirrus clouds is associated with a drying of the upper troposphere (enhanced during suppressed phases), whereas the occurrence of thick cirrus anvil clouds appears to be significantly related to a moistening of the upper troposphere.
On the Equilibration of Numerical Simulation of Internal Tide: A Case Study around the Hawaiian Ridge
Authors: Jin Guang-Zhen , Cao An-Zhou , Lv Xian-Qing 
Published: May 2017

AbstractTo investigate the equilibration of numerical simulation (ENS) of internal tide, a three-dimensional isopycnic coordinate internal tide model is applied to simulate the M2 internal tide on idealized topography and around the Hawaiian Ridge. An idealized experiment is carried out on a Gaussian topography, and the temporal variations of the baroclinic velocity and the baroclinic energy flux are analyzed, then ENS is studied, and two criteria are presented. Moreover, the impacts of four parameters [horizontal and vertical eddy viscosity coefficients, bottom friction coefficient, and damping coefficient (to parameterize the nonhydrostatic processes in the model)] on ENS during numerical simulations, the baroclinic velocity, the baroclinic tidal energy, and the baroclinic energy flux are investigated. It appears that ENS for the M2 internal tide is more sensitive to the horizontal eddy viscosity coefficient and the damping coefficient. To further examine the criteria of ENS, a numerical experiment is carried out to simulate the M2 internal tidal constituent near the Hawaiian Ridge. The simulated surface tide shows good agreement with results from the Oregon State University tidal model and TOPEX/Poseidon (T/P) observations. The simulation results indicate that a 50 M2 tidal period (25.88 days) run is capable of ensuring ENS for the M2 internal tide in this case. In short, this paper presents a method and two criteria for examining ENS for internal tides for modelers.
Real-time MRI-guided percutaneous sclerotherapy treatment of venous low-flow malformations in the head and neck
Authors: Partovi Sasan , Lu Ziang , Vidal Lorenna , Nakamoto Dean A , Buethe Ji , Coffey Michael , Patel Indravadan J 
Published: May 2017

Purpose This manuscript describes the technique of real-time MRI-guided sclerotherapy for low-flow venous malformations in the head and neck based on our institutional experience. Materials and methods Ethanolamine oleate is used as the sclerosant and is mixed with gadolinium for visualization during the procedure. The five procedural steps include: (I) an initial tri-plane T2-weighted sequence to visualize the lesion; (II) a T1 FSE or trueFISP sequence to assess needle placement and advancement within the lesion; (III) a tri-plane T1 FLASH sequence to monitor sclerosant injection; (IV) a T1 FSE or VIBE sequence to assess sclerosant coverage of the malformation before needle removal; (V) a post-procedural tri-plane T1 fat-saturated sequence to confirm sclerosant coverage of the lesion. Periprocedural medications typically include steroids, antibiotic prophylaxis, and non-steroidal anti-inflammatory medication. Patients are typically admitted for overnight observation. Conclusion Real-time MRI-guided sclerotherapy for low-flow venous malformations in the head and neck is effective and safe.
Seeing is believing – healthcare professionals’ perceptions of a complex intervention to improve care towards the end of life: A qualitative interview study
Authors: Bristowe Katherine , Carey Irene , Hopper Adrian , Shouls Susanna , Prentice Wendy , Higginson Irene J , Koffman Jonathan 
Published: May 2017

Background: Methods to improve care, trust and communication are important in acute hospitals. Complex interventions aimed at improving care of patients approaching the end of life are increasingly common. While evaluating outcomes of complex interventions is essential, exploring healthcare professionals’ perceptions is also required to understand how they are interpreted; this can inform training, education and implementation strategies to ensure fidelity and consistency in use. Aim: To explore healthcare professionals’ perceptions of using a complex intervention (AMBER care bundle) to improve care for people approaching the end of life and their understandings of its purpose within clinical practice. Design: Qualitative study of healthcare professionals. Analysis informed by Medical Research Council guidance for process evaluations. Setting/participants: A total of 20 healthcare professionals (12 nursing and 8 medical) interviewed from three London tertiary National Health Service hospitals. Healthcare professionals recruited from palliative care, oncology, stroke, health and ageing, medicine, neurology and renal/endocrine services. Results: Three views emerged regarding the purpose of a complex intervention towards the end of life: labelling/categorising patients, tool to change care delivery and serving symbolic purpose indirectly affecting behaviours of individuals and teams. All impact upon potential utility of the intervention. Participants described the importance of training and education alongside implementation of the intervention. However, adequate exposure to the intervention was essential to witness its potential added value or embed it into practice. Conclusion: Understanding differing interpretations of complex interventions is essential. Consideration of ward composition, casemix and potential exposure to the intervention is critical for their successful implementation.
Injectable chelate-setting hydroxyapatite cement prepared by using chitosan solution: Fabrication, material properties, biocompatibility, and osteoconductivity
Authors: Konishi Toshiisa , Honda Michiyo , Nagaya Masaki , Nagashima Hiroshi , Thian Eng San , Aizawa Mamoru 
Published: May 2017

An injectable chelate-setting hydroxyapatite cement (IP6-HAp), formed by chelate-bonding capability of inositol phosphate (IP6), was developed. The effects of ball-milling duration of starting HAp powder and IP6 concentration on the material properties such as injectability and mechanical strength of the cement were examined. The cement powder was prepared by ball-milling the as-synthesized HAp powder for 5 min using ZrO2 beads with a diameter of 10 mm, followed by another 60 min with ZrO2 beads with a diameter of 2 mm, and thereafter surface-modified with 5000 ppm of IP6 solution. Injectable cement was then fabricated with this HAp powder and 2.5 mass% chitosan as a mixing solution, with a setting time of 36.3 ± 4.7 min and a compressive strength of 19.0 ± 2.1 MPa. The IP6-HAp cements prepared with chitosan showed favorable biocompatibility in vitro using an osteoblast cell model, and osteoconductivity in vivo using a pig tibia model.
The Influence of Heating on Toe pressure in Patients with Peripheral Arterial Disease
Authors: Settembre N. , Kagayama T. , Kauhanen P. , Vikatmaa P. , Inoue Y. , Venermo M. 
Published: May 2017

Background and Aim: The toe skin temperature in vascular patients can be low, making reliable toe pressure measurements difficult to obtain. The aim of this study was to evaluate the effect of heating on the toe pressure measurements. Materials and Methods: A total of 86 legs were examined. Brachial pressure and toe pressure were measured at rest in a supine position using a laser Doppler device that also measured skin temperature. After heating the toes for 5 min with a heating pad, we re-measured the toe pressure. Furthermore, after heating the skin to 40° with the probe, toe pressures were measured a third time. Results: The mean toe skin temperature at the baseline measurement was 24.0 °C (standard deviation: 2.8). After heating the toes for 5 min with a warm heating pad, the skin temperature rose to a mean 27.8 °C (standard deviation: 2.8; p = 0.000). The mean toe pressure rose from 58.5 (standard deviation: 32) to 62 (standard deviation: 32) mmHg (p = 0.029). Furthermore, after the skin was heated up to 40 °C with the probe, the mean toe pressure in the third measurement was 71 (standard deviation: 34) mmHg (p = 0.000). The response to the heating varied greatly between the patients after the first heating—from −34 mmHg (toe pressure decreased from 74 to 40 mmHg) to +91 mmHg. When the toes were heated to 40 °C, the change in to toe pressure from the baseline varied between −28 and +103 mmHg. Conclusion: Our data indicate that there is a different response to the heating in different clinical situations and in patients with a different comorbidity.
A composite measure to explore visual disability in primary progressive multiple sclerosis
Authors: Poretto Valentina , Petracca Maria , Saiote Catarina , Mormina Enricomaria , Howard Jonathan , Miller Aaron , Lublin Fred D , Inglese Matilde 
Published: May 2017

Background Optical coherence tomography (OCT) and magnetic resonance imaging (MRI) can provide complementary information on visual system damage in multiple sclerosis (MS). Objectives The objective of this paper is to determine whether a composite OCT/MRI score, reflecting cumulative damage along the entire visual pathway, can predict visual deficits in primary progressive multiple sclerosis (PPMS). Methods Twenty-five PPMS patients and 20 age-matched controls underwent neuro-ophthalmologic evaluation, spectral-domain OCT, and 3T brain MRI. Differences between groups were assessed by univariate general linear model and principal component analysis (PCA) grouped instrumental variables into main components. Linear regression analysis was used to assess the relationship between low-contrast visual acuity (LCVA), OCT/MRI-derived metrics and PCA-derived composite scores. Results PCA identified four main components explaining 80.69% of data variance. Considering each variable independently, LCVA 1.25% was significantly predicted by ganglion cell-inner plexiform layer (GCIPL) thickness, thalamic volume and optic radiation (OR) lesion volume (adjusted R2 0.328, p = 0.00004; adjusted R2 0.187, p = 0.002 and adjusted R2 0.180, p = 0.002). The PCA composite score of global visual pathway damage independently predicted both LCVA 1.25% (adjusted R2 value 0.361, p = 0.00001) and LCVA 2.50% (adjusted R2 value 0.323, p = 0.00003). Conclusion A multiparametric score represents a more comprehensive and effective tool to explain visual disability than a single instrumental metric in PPMS.