Publications by authors named "Rafael Ramírez"

159 Publications

Eccentric hypertrophy in an animal model of mid- and long-term premature ventricular contraction-induced cardiomyopathy.

Heart Rhythm O2 2021 Feb 8;2(1):80-88. Epub 2021 Jan 8.

Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia.

Background: Tachycardia and heart rate irregularity are proposed triggers of premature ventricular contraction-induced cardiomyopathy (PVC-cardiomyopathy). Bigeminal premature atrial and ventricular contractions (PACs and PVCs) increase heart rate and result in rhythm irregularities but differ in their effects on ventricular synchrony. Comparing chronic bigeminal PACs with PVCs would provide insights into mechanisms of PVC-cardiomyopathy.

Objective: To compare the impact of chronic PACs and PVCs on ventricular hemodynamics, structure, and function.

Methods: Pacemakers were implanted in 27 canines to reproduce atrial (PACs, n = 7) or ventricular bigeminy (PVCs, n = 11) for 12 weeks, and compared to sham-operated animals (n = 9). Four additional animals were exposed to long-term bigeminal PVCs (48 weeks). Hemodynamic changes were assessed using a pressure-transducing catheter at baseline and 12 weeks. Cardiac remodeling was monitored by transthoracic echocardiography throughout the 12- and 48-week protocols in the respective groups.

Results: PVC group demonstrated a significant decrease in left ventricular (LV) ejection fraction and contractility (max dP/dt), impaired LV lusitropy (min dP/dt), and increase in LV dimensions and LV mass at 12 weeks without further deterioration beyond 16 weeks. Despite increased LV mass, relative wall thickness decreased, consistent with eccentric hypertrophy. No significant cardiac remodeling was noted in either sham or PAC groups at 12 weeks.

Conclusion: In contrast to bigeminal PACs, PVCs result in a cardiomyopathy characterized by reduced LV ejection fraction, LV dilation, and eccentric hypertrophy that plateaus between 12 and 16 weeks. The lack of remodeling in chronic PACs suggests that tachycardia and heart rate irregularity do not play a significant role on the development of PVC-cardiomyopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.hroo.2020.12.021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8183810PMC
February 2021

Geographic Heterogeneity in Influenza and Pneumonia Mortality in Hispanic Americans.

Int J Environ Res Public Health 2021 May 5;18(9). Epub 2021 May 5.

Department of Medicine, Howard University College of Medicine, Washington, DC 20059, USA.

(1) : Influenza and pneumonia (IP) is a leading cause of death in the US. The hypothesis was tested that the mortality rate differential between Hispanic whites (HW) and non-Hispanic whites (NHW) from IP varied by geographic region in the US. (2) : The CDC database for multiple causes of death between 1999-2018 was used for this study. For ages 25-84, age-adjusted mortality rates per 100,000 (AAMR) for IP were computed by Hispanic ethnicity in whites for 10 Health & Human Services (HHS) regions and for urbanization levels in HHS Region 2. (3) : AAMR for IP was 13.76 (13.62-13.9) in HW and 14.91 (14.86-14.95) in NHW (rate ratio 1.08). Among HHS regions, rates were generally lower in HW than in NHW with the major exception of HHS Region 2. The rate there was 21.78 (21.24-22.33) in HW, 36.5% greater ( < 0.05) than that in NHW of 15.71 (15.56-15.86). In large central metro areas of Region 2, the rate was 27.10 (26.36-27.83) in HW compared to 19.78 (19.47-20.09) in NHW. (4) : The difference in AAMR from IP between HW and NHW varied by region and urbanization with much higher rates for HW than NHW only in metropolitan areas of New York and New Jersey.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18094917DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8125250PMC
May 2021

Real-Time Sound and Motion Feedback for Violin Bow Technique Learning: A Controlled, Randomized Trial.

Front Psychol 2021 26;12:648479. Epub 2021 Apr 26.

Music and Machine Learning Lab, Department of Information and Communications Technologies, Universitat Pompeu Fabra, Barcelona, Spain.

The production of good sound generation in the violin is a complex task that requires coordination and spatiotemporal control of bowing gestures. The use of motion-capture technologies to improve performance or reduce injury risks in the area of kinesiology is becoming widespread. The combination of motion accuracy and sound quality feedback has the potential of becoming an important aid in violin learning. In this study, we evaluate motion-capture and sound-quality analysis technologies developed inside the context of the TELMI, a technology-enhanced music learning project. We analyzed the sound and bow motion of 50 participants with no prior violin experience while learning to produce a stable sound in the violin. Participants were divided into two groups: the experimental group ( = 24) received real-time visual feedback both on kinematics and sound quality, while participants in the control group ( = 26) practiced without any type of external help. An additional third group of violin experts performed the same task for comparative purposes ( = 15). After the practice session, all groups were evaluated in a transfer phase without feedback. At the practice phase, the experimental group improved their bowing kinematics in comparison to the control group, but this was at the expense of impairing the sound quality of their performance. At the retention phase, the experimental group showed better results in sound quality, especially concerning control of sound dynamics. Besides, we found that the expert group improved the stability of their sound while using the technology. All in all, these results emphasize the importance of feedback technologies in learning complex tasks, such as musical instrument learning.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2021.648479DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8107276PMC
April 2021

A high magnesium concentration in citrate dialysate prevents oxidative stress and damage in human monocytes .

Clin Kidney J 2021 May 30;14(5):1403-1411. Epub 2020 Aug 30.

Dpto de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.

Background: The use of dialysis fluids (DFs) during haemodialysis has been associated with increased oxidative stress and reduced serum magnesium (Mg) levels, contributing to chronic inflammation. Since the role of Mg in modulating immune function and reducing oxidative stress has been demonstrated, the aim of this study was to characterize whether increasing the Mg concentration in DFs could protect immune cells from oxidative stress and damage.

Methods: The effect of citrate [citrate dialysis fluid (CDF), 1 mM] or acetate [acetate dialysis fluid (ADF), 3 mM] dialysates with low (0.5 mM; routinely used) or high (1 mM, 1.25 mM and 2 mM) Mg concentrations was assessed in THP-1 human monocytes. The levels of reactive oxygen species (ROS), malondialdehyde (MDA) and oxidized/reduced (GSSG/GSH) glutathione were quantified under basal and inflammatory conditions (stimulation with lipopolysaccharide, LPS).

Results: The increase of Mg in CDF resulted in a significant reduction of ROS production under basal and inflammatory conditions (extremely marked in 2 mM Mg; P 0.001). These effects were not observed in ADF. Interestingly, in a dose-dependent manner, high Mg doses in CDF reduced oxidative stress in monocytes under both basal and inflammatory conditions. In fact, 2 mM Mg significantly decreased the levels of GSH, GSSG and MDA and the GSSG/GSH ratio in relation to 0.5 mM Mg.

Conclusions: CDF produces lower oxidative stress than ADF. The increase of Mg content in DFs, especially in CDF, could have a positive and protective effect in reducing oxidative stress and damage in immune cells, especially under inflammatory conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ckj/sfaa131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087128PMC
May 2021

Applying Deep Learning Techniques to Estimate Patterns of Musical Gesture.

Front Psychol 2020 5;11:575971. Epub 2021 Jan 5.

Music Technology Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain.

Repetitive practice is one of the most important factors in improving the performance of motor skills. This paper focuses on the analysis and classification of forearm gestures in the context of violin playing. We recorded five experts and three students performing eight traditional classical violin bow-strokes: , and . To record inertial motion information, we utilized the sensor, which reports a multidimensional time-series signal. We synchronized inertial motion recordings with audio data to extract the spatiotemporal dynamics of each gesture. Applying state-of-the-art deep neural networks, we implemented and compared different architectures where convolutional neural networks (CNN) models demonstrated recognition rates of 97.147%, 3DMultiHeaded_CNN models showed rates of 98.553%, and rates of 99.234% were demonstrated by CNN_LSTM models. The collected data (quaternion of the bowing arm of a violinist) contained sufficient information to distinguish the bowing techniques studied, and deep learning methods were capable of learning the movement patterns that distinguish these techniques. Each of the learning algorithms investigated (CNN, 3DMultiHeaded_CNN, and CNN_LSTM) produced high classification accuracies which supported the feasibility of training classifiers. The resulting classifiers may provide the foundation of a digital assistant to enhance musicians' time spent practicing alone, providing real-time feedback on the accuracy and consistency of their musical gestures in performance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2020.575971DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813937PMC
January 2021

Electroanalytical study of five carbosilane dendrimers at the interface between two immiscible electrolyte solutions.

Analyst 2021 Feb 6;146(4):1376-1385. Epub 2021 Jan 6.

Department of Inorganic and Analytical Chemistry, Electroanalysis and Electrochemistry Group, Faculty of Chemistry, University of Lodz, Tamka 12, 91-403 Lodz, Poland.

This work is focused on the electroanalytical study of a family of five imidazolium-terminated carbosilane dendrimers (from generation G1 to G3) at the polarized liquid-liquid interface formed between water and 1,2-dichloroethane solutions. All dendrimers with permanently and positively charged imidazolium groups located at the periphery within the branched carbosilane core were found to be electrochemically active. Based on the concentration and scan rate dependencies we have concluded that these molecules undergo interfacial ion transfer processes accompanied by interfacial adsorption/desorption rather than the electrochemically induced interfacial formation of the macromolecule-anion (tetrakis(4-chlorophenyl)borate) from the organic phase complex. Also, we report several physicochemical and electroanalytical parameters (e.g. diffusion coefficients, LODs, and detection sensitivities) for the studied family of dendrimers. Our work aims to contribute to the understating of the interaction between branched macromolecules and biomimetic interfaces.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0an02101fDOI Listing
February 2021

Transcriptome and proteome mapping in the sheep atria reveal molecular features of atrial fibrillation progression.

Cardiovasc Res 2020 Oct 29. Epub 2020 Oct 29.

Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain.

Aims: Atrial fibrillation (AF) is a progressive cardiac arrhythmia that increases the risk of hospitalization and adverse cardiovascular events. There is a clear demand for more inclusive and large-scale approaches to understand the molecular drivers responsible for AF, as well as the fundamental mechanisms governing the transition from paroxysmal to persistent and permanent forms. In this study, we aimed to create a molecular map of AF and find the distinct molecular programs underlying cell type-specific atrial remodelling and AF progression.

Methods And Results: We used a sheep model of long-standing, tachypacing-induced AF, sampled right and left atrial tissue and isolated cardiomyocytes from control, intermediate (transition) and late time points during AF progression, and performed transcriptomic and proteome profiling. We have merged all these layers of information into a meaningful 3-component space in which we explored the genes and proteins detected and their common patterns of expression. Our data-driven analysis points at extracellular matrix remodelling, inflammation, ion channel, myofibril structure, mitochondrial complexes, chromatin remodelling, and genes related to neural function, as well as critical regulators of cell proliferation as hallmarks of AF progression. Most important, we prove that these changes occur at early transitional stages of the disease, but not at later stages, and that the left atrium undergoes significantly more profound changes than the right atrium in its expression program. The pattern of dynamic changes in gene and protein expression replicate the electrical and structural remodelling demonstrated previously in the sheep and in humans, and uncover novel mechanisms potentially relevant for disease treatment.

Conclusions: Transcriptomic and proteomic analysis of AF progression in a large animal model shows that significant changes occur at early stages, and that among others involve previously undescribed increase in mitochondria, changes to the chromatin of atrial cardiomyocytes, and genes related to neural function and cell proliferation.

Translational Perspective: We have generated a detailed molecular map of AF progression in a clinically relevant large-animal model. Such data would be very difficult if not impossible to obtain from patients. Our results provide a framework for a comprehensive molecular analysis of the disease, pointing to novel avenues of research toward identifying early events that can lead to therapeutically targets to prevent AF-induced atrial remodelling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cvr/cvaa307DOI Listing
October 2020

Mitigating the Impact of the Novel Coronavirus Pandemic on Neuroscience and Music Research Protocols in Clinical Populations.

Front Psychol 2020 28;11:2160. Epub 2020 Aug 28.

The Louis Armstrong Center for Music and Medicine, Mount Sinai Beth Israel, Icahn School of Medicine, New York, NY, United States.

The COVID-19 disease and the systemic responses to it has impacted lives, routines and procedures at an unprecedented level. While medical care and emergency response present immediate needs, the implications of this pandemic will likely be far-reaching. Most practices that the clinical research within neuroscience and music field rely on, take place in hospitals or closely connected clinical settings which have been hit hard by the contamination. So too have its preventive and treatment measures. This means that clinical research protocols may have been altered, postponed or put in complete jeopardy. In this context, we would like to present and discuss the problems arising under the current crisis. We do so by critically approaching an online discussion facilitated by an expert panel in the field of music and neuroscience. This effort is hoped to provide an efficient basis to orient ourselves as we begin to map the needs and elements in this field of research as we further propose ideas and solutions on how to overcome, or at least ease the problems and questions we encounter or will encounter, with foresight. Among others, we hope to answer questions on technical or social problems that can be expected, possible solutions and preparatory steps to take in order to improve or ease research implementation, ethical implications and funding considerations. Finally, we further hope to facilitate the process of creating new protocols in order to minimize the impact of this crisis on essential research which may have the potential to relieve health systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2020.02160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7484479PMC
August 2020

Measuring the Impacts of Extra-Musical Elements in Guitar Music Playing: A Pilot Study.

Front Psychol 2020 14;11:1964. Epub 2020 Aug 14.

Department of Music, Faculty of Art, University of Quebec in Montreal, Montreal, QC, Canada.

Philosophers, composers, and musicians have long argued whether instrumental music finds meaning in its formal structure and musical content (Hanslick, 1986) or through reference to extra-musical elements, like narratives, emotions, or memories (Meyer, 1956). While the use of extra-musical elements appears grounded in individual musicians' priorities for performance and teaching (Héroux, 2018), the impact of emotional indications on expressivity has not previously been studied in a large-scale experiment. The aim of this pilot study was to construct the methodology for a larger project to study the impact of the use of extra-musical elements on the sound results of guitarists. We asked guitar students to record one short newly composed piece, Evocation 1, according to the following conditions: (A) in a non-expressive manner, (B) according to the notated musical indications, and (C) with the addition of suggested contextual and emotional extra-musical elements to the musical instructions. We asked two expert guitarists to evaluate the level of expressiveness for conditions B and C and conducted interviews with participants to collect data on the experimental process to refine protocol. To more objectively measure manifestations of objectivity from the recorded performances, we extracted data from each recording about pitch, dynamics, and timing, as well as expressive dynamic deviations. The impact of both recording conditions and the expertise level of performers on the quality of this audio data led us to change the analysis design from a comparative design (with other participants) to a self-comparative design (each participant with himself) for the larger study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2020.01964DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7457134PMC
August 2020

Microvesicles from indoxyl sulfate-treated endothelial cells induce vascular calcification .

Comput Struct Biotechnol J 2020 9;18:953-966. Epub 2020 Apr 9.

Departamento de Biología de Sistemas, Universidad de Alcalá (IRYCIS), Alcalá de Henares, Madrid, Spain.

Vascular calcification (VC), an unpredictable pathophysiological process and critical event in patients with cardiovascular diseases (CVDs), is the leading cause of morbi-mortality and disability in chronic kidney disease (CKD) patients worldwide. Currently, no diagnostic method is available for identifying patients at risk of VC development; the pathology is detected when the process is irreversible. Extracellular vesicles (EVs) from endothelial cells might promote VC. Therefore, their evaluation and characterization could be useful for designing new diagnostic tools. The aim of the present study is to investigate whether microvesicles (MVs) from endothelial cells damaged by uremic toxin and indoxyl sulfate (IS) could induce calcification in human vascular smooth muscle cells (VMSCs). Besides, we have also analyzed the molecular mechanisms by which these endothelial MVs can promote VC development. Endothelial damage has been evaluated according to the percentage of senescence in endothelial cells, differential microRNAs in endothelial cells, and the amount of MVs released per cell. To identify the role of MVs in VC, VSMCs were treated with MVs from IS-treated endothelial cells. Calcium, inflammatory gene expression, and procalcification mediator levels in VSMCs were determined. IS-treated endothelial cells underwent senescence and exhibited modulated microRNA expression and an increase in the release of MVs. VSMCs exposed to these MVs modulated the expression of pro-inflammatory genes and some mediators involved in calcification progression. MVs produced by IS-treated endothelial cells promoted calcification in VSMCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.csbj.2020.04.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7184105PMC
April 2020

Presumptive asymptomatic COVID-19 carriers' estimation and expected person-to-person spreading among repatriated passengers returning from China.

Travel Med Infect Dis 2020 Sep - Oct;37:101688. Epub 2020 Apr 21.

Grupo de Investigaciones Microbiológicas-UR (GIMUR), Departamento de Biología, Facultad de Ciencias Naturales, Universidad del Rosario, Colombia. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tmaid.2020.101688DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7194508PMC
October 2020

Increasing the Magnesium Concentration in Various Dialysate Solutions Differentially Modulates Oxidative Stress in a Human Monocyte Cell Line.

Antioxidants (Basel) 2020 Apr 15;9(4). Epub 2020 Apr 15.

Departamento de Biología de Sistemas, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain.

Oxidative stress is exacerbated in hemodialysis patients by several factors, including the uremic environment and the use of dialysis fluids (DFs) Since magnesium (Mg) plays a key role in modulating immune function and in reducing oxidative stress, we aimed to evaluate whether increasing the Mg concentration in different DFs could protect against oxidative stress in immunocompetent cells in vitro. Effect of ADF (acetate 3 mM), CDF (citrate 1 mM), and ACDF (citrate 0.8 mM + acetate 0.3 mM) dialysates with Mg at standard (0.5 mM) or higher (1, 1.25, and 2 mM) concentrations were assessed in THP-1 monocyte cultures. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels were quantified under basal and uremic conditions (indoxyl sulfate (IS) treatment). Under uremic conditions, the three DFs with 0.5 mM Mg promoted higher ROS production and lipid damage than the control solution. However, CDF and ACDF induced lower levels of ROS and MDA, compared to that induced by ADF. High Mg concentration (1.25 and/or 2 mM) in CDF and ACDF protected against oxidative stress, indicated by reduced ROS and MDA levels compared to respective DFs with standard concentration of Mg. Increasing Mg concentrations in ADF promoted high ROS production and MDA content. Thus, an increase in Mg content in DFs has differential effects on the oxidative stress in IS-treated THP-1 cells depending on the dialysate used.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/antiox9040319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7222382PMC
April 2020

Mechanisms of Cardiovascular Disorders in Patients With Chronic Kidney Disease: A Process Related to Accelerated Senescence.

Front Cell Dev Biol 2020 20;8:185. Epub 2020 Mar 20.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.

Cardiovascular diseases (CVDs), especially those involving a systemic inflammatory process such as atherosclerosis, remain the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD). CKD is a systemic condition affecting approximately 10% of the general population. The prevalence of CKD has increased over the past decades because of the aging of the population worldwide. Indeed, CVDs in patients with CKD constitute a premature form of CVD observed in the general population. Multiple studies indicate that patients with renal disease undergo accelerated aging, which precipitates the appearance of pathologies, including CVDs, usually associated with advanced age. In this review, we discuss several aspects that characterize CKD-associated CVDs, such as etiopathogenic elements that CKD patients share with the general population, changes in the cellular balance of reactive oxygen species (ROS), and the associated process of cellular senescence. Uremia-associated aging is linked with numerous changes at the cellular and molecular level. These changes are similar to those observed in the normal process of physiologic aging. We also discuss new perspectives in the study of CKD-associated CVDs and epigenetic alterations in intercellular signaling, mediated by microRNAs and/or extracellular vesicles (EVs), which promote vascular damage and subsequent development of CVD. Understanding the processes and factors involved in accelerated senescence and other abnormal intercellular signaling will identify new therapeutic targets and lead to improved methods of diagnosis and monitoring for patients with CKD-associated CVDs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcell.2020.00185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7099607PMC
March 2020

Data supporting the evaluation of the energy recovery potential of thermoelectric generators in diesel engines.

Data Brief 2020 Feb 30;28:105075. Epub 2019 Dec 30.

Universidad del Atlántico, Department of Mechanical Engineering, Carrera 30 Número 8 - 49, Puerto Colombia, Área Metropolitana de Barranquilla, Colombia.

Power generation with thermoelectric devices in internal combustion engines is an alternative to recover some of the energy loss with the exhausts. This data article supports a study that assesses the potentialities of energy recovery with thermoelectric generators in diesel engines and its influence on gaseous emissions. To this end, a set of experiments was developed with a thermoelectric generator and a waffle heat exchanger. The experimental design included nine operation points of the engine to characterize the energy recovery of the thermoelectric generator under different exploitation conditions. Three different fuels (i.e., diesel, B5, and B10) were used. The experiments were developed in a test bench with three data acquisition systems to measure the operational variables (e.g., electric power generation, pressure drop, temperature, etc.). Moreover, a gas analyzer (BrainBee AGS-688), Bacharach gas analyzer (PCA 400), and a smoke meter (BrainBee OPA-100) were used to measure exhaust emissions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.dib.2019.105075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7096681PMC
February 2020

Post-extrasystolic potentiation as a predictor of premature ventricular contraction-cardiomyopathy in an animal model.

Europace 2020 05;22(5):813-820

Pauley Heart Center, Virginia Commonwealth University, Richmond, Ste. 4A-100, Richmond, VA 23249, USA.

Aims: High premature ventricular contractions (PVCs) burden does not always predict the development of PVC-cardiomyopathy (CM). We sought to evaluate post-extrasystolic potentiation (PESP) of left ventricular ejection fraction (LVEF) to predict the severity of PVC-CM in an animal model.

Methods And Results: Right ventricular apical bigeminal PVCs were introduced for 12 weeks in 11 canines to induce PVC-CM. Echocardiograms were performed to obtain LVEF without ectopy (Echo-1) and during PVCs (200 and 350 ms coupling intervals, Echo-2, and Echo-3, respectively), and premature atrial contractions (PACs) (Echo-4) at baseline and after 12 weeks of bigeminal PVCs. PESP was calculated as delta-LVEF between the sinus beat post-ectopy LVEF (Echo-2, -3, and -4, respectively) and LVEF without PVC (Echo-1) at baseline and 12 weeks of high PVC burden. A hyperdynamic LV function (LVEF > 70%) was noted in all animals only with early-coupled PVCs (LVEF at 200 ms: 74.4 ± 6%) at baseline. While PVC PESP at 200 ms had a strong significant correlation with the final 12-week LVEF (R = 0.8, P = 0.003), PVC PESP at 350 ms and PAC PESP had a positive but non-significant correlation (R = 0.53, P = 0.09, and R = 0.29, P = 0.34, respectively). Premature ventricular contraction PESP at 350 ms was significantly higher after PVC-CM had developed (delta-LVEF baseline 2.7 ± 2.9% vs. 12 weeks 18.6 ± 12.3% P < 0.001).

Conclusion: Bigeminal early-coupled PVCs cause hyperdynamic left ventricular function in the structurally normal canine heart due to PESP. The degree of PESP at baseline is inversely proportional to the PVC-CM severity at 12 weeks and maybe a predictor of PVC-CM as it may assess the myocardial adaptation reserve to PVCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/europace/euaa025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7828467PMC
May 2020

Hypoxia-Inducible Factor-1α: The Master Regulator of Endothelial Cell Senescence in Vascular Aging.

Cells 2020 01 13;9(1). Epub 2020 Jan 13.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud (IRYCIS), Universidad de Alcalá, Alcalá de Henares, 28805 Madrid, Spain.

Aging is one of the hottest topics in biomedical research. Advances in research and medicine have helped to preserve human health, leading to an extension of life expectancy. However, the extension of life is an irreversible process that is accompanied by the development of aging-related conditions such as weakness, slower metabolism, and stiffness of vessels. It also debated that aging can be considered an actual disease with aging-derived comorbidities, including cancer or cardiovascular disease. Currently, cardiovascular disorders, including atherosclerosis, are considered as premature aging and represent the first causes of death in developed countries, accounting for 31% of annual deaths globally. Emerging evidence has identified hypoxia-inducible factor-1α as a critical transcription factor with an essential role in aging-related pathology, in particular, regulating cellular senescence associated with cardiovascular aging. In this review, we will focus on the regulation of senescence mediated by hypoxia-inducible factor-1α in age-related pathologies, with particular emphasis on the crosstalk between endothelial and vascular cells in age-associated atherosclerotic lesions. More specifically, we will focus on the characteristics and mechanisms by which cells within the vascular wall, including endothelial and vascular cells, achieve a senescent phenotype.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cells9010195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016968PMC
January 2020

Mechanisms by Which Ranolazine Terminates Paroxysmal but Not Persistent Atrial Fibrillation.

Circ Arrhythm Electrophysiol 2019 10 9;12(10):e005557. Epub 2019 Oct 9.

Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.).

Background: Ranolazine inhibits Na current (I), but whether it can convert atrial fibrillation (AF) to sinus rhythm remains unclear. We investigated antiarrhythmic mechanisms of ranolazine in sheep models of paroxysmal (PxAF) and persistent AF (PsAF).

Methods: PxAF was maintained during acute stretch (N=8), and PsAF was induced by long-term atrial tachypacing (N=9). Isolated, Langendorff-perfused sheep hearts were optically mapped.

Results: In PxAF ranolazine (10 μmol/L) reduced dominant frequency from 8.3±0.4 to 6.2±0.5 Hz (<0.01) before converting to sinus rhythm, decreased singularity point density from 0.070±0.007 to 0.039±0.005 cm s (<0.001) in left atrial epicardium (LA), and prolonged AF cycle length (AFCL); rotor duration, tip trajectory, and variance of AFCL were unaltered. In PsAF, ranolazine reduced dominant frequency (8.3±0.5 to 6.5±0.4 Hz; <0.01), prolonged AFCL, increased the variance of AFCL, had no effect on singularity point density (0.048±0.011 to 0.042±0.016 cm s; =ns) and failed to convert AF to sinus rhythm. Doubling the ranolazine concentration (20 μmol/L) or supplementing with dofetilide (1 μmol/L) failed to convert PsAF to sinus rhythm. In computer simulations of rotors, reducing I decreased dominant frequency, increased tip meandering and produced vortex shedding on wave interaction with unexcitable regions.

Conclusions: PxAF and PsAF respond differently to ranolazine. Cardioversion in the former can be attributed partly to decreased dominant frequency and singularity point density, and prolongation of AFCL. In the latter, increased dispersion of AFCL and likely vortex shedding contributes to rotor formation, compensating for any rotor loss, and may underlie the inefficacy of ranolazine to terminate PsAF.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/CIRCEP.117.005557DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6788778PMC
October 2019

Variability in triage practices for critically ill cancer patients: A randomized controlled trial.

J Crit Care 2019 10 29;53:18-24. Epub 2019 May 29.

Department of Critical Care, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Unit 112, Houston, TX 77030, United States of America. Electronic address:

Purpose: Intensive care triage practices and end-user interpretation of triage guidelines have rarely been assessed. We evaluated agreement between providers on the prioritization of patients for ICU admission using different triage guidelines.

Materials And Methods: A multi-centered randomized study on providers from 18 different countries was conducted using clinical vignettes of oncological patients. The level of agreement between providers was measured using two different guidelines, with one being cancer specific.

Results: Amongst 257 providers, 52.5% randomly received the Society of Critical Care Prioritization Model, and 47.5% received a cancer specific flowchart as a guide. In the Prioritization Model arm the average entropy was 1.193, versus 1.153 in the flowchart arm (P = .095) indicating similarly poor agreement. The Fleiss' kappa coefficients were estimated to be 0.2136 for the SCCMPM arm and 0.2457 for the flowchart arm, also similarly implying poor agreement.

Conclusions: The low agreement amongst practitioners on the prioritization of cancer patient cases for ICU admission existed using both general triage guidelines and guidelines tailored only to cancer patients. The lack of consensus on intensive care unit triage practices in the oncological population exposes a potential barrier to appropriate resource allocation that needs to be addressed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcrc.2019.05.012DOI Listing
October 2019

Nuclear quantum effects in graphene bilayers.

J Chem Phys 2019 May;150(20):204707

Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain.

Graphene bilayers display peculiar electronic and mechanical characteristics associated with their two-dimensional character and relative disposition of the sheets. Here, we study nuclear quantum effects in graphene bilayers by using path-integral molecular dynamics simulations, which allow us to consider quantization of vibrational modes and study the effect of anharmonicity on physical variables. Finite-temperature properties are analyzed in the range from 12 to 2000 K. Our results for graphene bilayers are compared with those found for graphene monolayers and graphite. Nuclear quantum effects turn out to be appreciable in the layer area and interlayer distance at finite temperatures. Differences in the behavior of in-plane and real areas of the graphene sheets are discussed. The interlayer spacing has a zero-point expansion of 1.5 × 10 Å with respect to the classical minimum. The compressibility of graphene bilayers in the out-of-plane direction is found to be similar to that of graphite at low temperatures and increases faster as the temperature is raised. The low-temperature compressibility increases by 6% due to zero-point motion. Special emphasis is placed on atomic vibrations in the out-of-plane direction. Quantum effects are present in these vibrational modes, but classical thermal motion becomes dominant over quantum delocalization for large system size. The significance of anharmonicities in this atomic motion is estimated by comparing with a harmonic approximation for the vibrational modes in graphene bilayers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.5096602DOI Listing
May 2019

MicroRNA-126 regulates Hypoxia-Inducible Factor-1α which inhibited migration, proliferation, and angiogenesis in replicative endothelial senescence.

Sci Rep 2019 05 14;9(1):7381. Epub 2019 May 14.

Departamento Biología de Sistemas, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá (IRYCIS), Alcalá de Henares, Madrid, Spain.

Whereas a healthy endothelium maintains physiological vascular functions, endothelial damage contributes to the development of cardiovascular diseases. Endothelial senescence is the main determinant of endothelial dysfunction and thus of age-related cardiovascular disease. The objective of this study is to test the involvement of microRNA-126 and HIF-1α in a model of replicative endothelial senescence and the interrelationship between both molecules in this in vitro model. We demonstrated that senescent endothelial cells experience impaired tube formation and delayed wound healing. Senescent endothelial cells failed to express HIF-1α, and the microvesicles released by these cells failed to carry HIF-1α. Of note, HIF-1α protein levels were restored in HIF-1α stabilizer-treated senescent endothelial cells. Finally, we show that microRNA-126 was downregulated in senescent endothelial cells and microvesicles. With regard to the interplay between microRNA-126 and HIF-1α, transfection with a microRNA-126 inhibitor downregulated HIF-1α expression in early passage endothelial cells. Moreover, while HIF-1α inhibition reduced tube formation and wound healing closure, microRNA-126 levels remained unchanged. These data indicate that HIF-1α is a target of miRNA-126 in protective and reparative functions, and suggest that their therapeutic modulation could benefit age-related vascular disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-43689-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6517399PMC
May 2019

Phrase-Level Modeling of Expression in Violin Performances.

Front Psychol 2019 11;10:776. Epub 2019 Apr 11.

Music Technology Group, Machine Learning and Music Lab, Department of Communication and Information Technology, Pompeu Fabra University, Barcelona, Spain.

Expression is a key skill in music performance, and one that is difficult to address in music lessons. Computational models that learn from expert performances can help providing suggestions and feedback to students. We propose and analyze an approach to modeling variations in dynamics and note onset timing for solo violin pieces with the purpose of facilitating expressive performance learning in new pieces, for which no reference performance is available. The method generates phrase-level predictions based on musical score information on the assumption that expressiveness is idiomatic, and thus influenced by similar-sounding melodies. Predictions were evaluated numerically using three different datasets and against note-level machine-learning models, and also perceptually by listeners, who were presented to synthesized versions of musical excerpts, and asked to choose the most human-sounding one. Some of the presented excerpts were synthesized to reflect the variations in dynamics and timing predicted by the model, whereas others were shaped to reflect the dynamics and timing of an actual expert performance, and a third group was presented with no expressive variations. surprisingly, none of the three synthesized versions was consistently selected as human-like nor preferred with statistical significance by listeners. Possible interpretations of these results include the fact that the melodies might have been impossible to interpret outside their musical context, or that expressive features that were left out of the modeling such as note articulation and vibrato are, in fact, essential to the perception of expression in violin performance. Positive feedback by some listeners toward the modeled melodies in a blind setting indicate that the modeling approach was capable of generating appropriate renditions at least for a subset of the data. Numerically, performance in phrase-level suffers a small degradation if compared to note-level, but produces predictions easier to interpret visually, thus more useful in a pedagogical setting.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.00776DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6470278PMC
April 2019

Automatic Assessment of Tone Quality in Violin Music Performance.

Front Psychol 2019 14;10:334. Epub 2019 Mar 14.

Music Technology Group, Music and Machine Learning Lab, Department of Communications and Technology, Pompeu Fabra University, Barcelona, Spain.

The automatic assessment of music performance has become an area of increasing interest due to the growing number of technology-enhanced music learning systems. In most of these systems, the assessment of musical performance is based on pitch and onset accuracy, but very few pay attention to other important aspects of performance, such as sound quality or timbre. This is particularly true in violin education, where the quality of timbre plays a significant role in the assessment of musical performances. However, obtaining quantifiable criteria for the assessment of timbre quality is challenging, as it relies on consensus among the subjective interpretations of experts. We present an approach to assess the quality of timbre in violin performances using machine learning techniques. We collected audio recordings of several tone qualities and performed perceptual tests to find correlations among different timbre dimensions. We processed the audio recordings to extract acoustic features for training tone-quality models. Correlations among the extracted features were analyzed and feature information for discriminating different timbre qualities were investigated. A real-time feedback system designed for pedagogical use was implemented in which users can train their own timbre models to assess and receive feedback on their performances.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.00334DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6427949PMC
March 2019

Bowing Gestures Classification in Violin Performance: A Machine Learning Approach.

Front Psychol 2019 4;10:344. Epub 2019 Mar 4.

Music Technology Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain.

Gestures in music are of paramount importance partly because they are directly linked to musicians' sound and expressiveness. At the same time, current motion capture technologies are capable of detecting body motion/gestures details very accurately. We present a machine learning approach to automatic violin bow gesture classification based on Hierarchical Hidden Markov Models (HHMM) and motion data. We recorded motion and audio data corresponding to seven representative bow techniques (, and ) performed by a professional violin player. We used the commercial device for recording inertial motion information from the right forearm and synchronized it with audio recordings. Data was uploaded into an online public repository. After extracting features from both the motion and audio data, we trained an HHMM to identify the different bowing techniques automatically. Our model can determine the studied bowing techniques with over 94% accuracy. The results make feasible the application of this work in a practical learning scenario, where violin students can benefit from the real-time feedback provided by the system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.00344DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6409498PMC
March 2019

Evaluation of a Sound Quality Visual Feedback System for Bow Learning Technique in Violin Beginners: An EEG Study.

Front Psychol 2019 12;10:165. Epub 2019 Feb 12.

Music and Machine Learning Lab, Universitat Pompeu Fabra, Barcelona, Spain.

Current music technologies can assist in the process of learning to play a musical instrument and provide objective measures for evaluating the improvement of music students in concrete music tasks. In this paper, we investigated the effects of a sound quality visual feedback system (SQVFS) in violin learning. In particular, we studied the EEG activity of a group of participants with no previous violin playing experience while they learned to produce a stable sound (regarding pitch, dynamics, and timbre) in order to find motor learning biomarkers in a music task. Eighteen subjects with no prior experience in violin playing were divided into two groups: participants in the first group (experimental group, = 9) practiced with instructional videos and offline feedback from the SQVFS provided in alternation with their performance, while participants in a second group (control group, = 9) practiced with the instructional videos only. A third group of violin experts (players with more than 6 years of experience) performed the same task for comparative purposes ( = 7). All participants were asked to perform 20 trials (4 blocks of 5 trials) consisting of a violin bowing exercise while their EEG activity and their produced sound was recorded. Significant sound quality improvements along the session were found in all participants with the exception of participants in the expert group. In addition, participants in the experimental group showed increased interest in the learning process and significant improvement after the second block not present in the control group. A significant correlation between the levels of frontal gamma band power and the sound improvement along the task was found in both the experimental and control group. This result is consistent with the temporal binding model which associates gamma band power with the role of integrating (binding) information processed in distributed cortical areas. Task complexity demands more cognitive resources, more binding and thus, gamma band power enhancement, which may be reduced as the demanded task begins to be automated as it is likely to be the case in both beginners groups.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2019.00165DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379259PMC
February 2019

Description and distribution of sp. nov. and in the Transmexican Volcanic Belt.

MycoKeys 2018 11(41):17-27. Epub 2018 Oct 11.

Instituto Tecnológico de Ciudad Victoria. Av. Portes Gil 1301 Poniente, 87010 Ciudad Victoria, Tamaulipas, México.

The genus is a lineage of diverse ectomycorrhizal, hypogeous, sequestrate ascomycete fungi that are native to temperate forests in the Northern Hemisphere. Recently, many new species of have been described in North America and Asia, based on morphological characteristics and molecular data. Here we describe and illustrate a new species, , based upon phylogenetic analysis and morphological description. We also present a new record for in México. These two species are distributed in the Transmexican Volcanic Belt in the states of México, Michoacán, Guanajuato, Querétaro and Tlaxcala at altitudes between 2,000 and 3,200 meters. These species are associated with () and forests ().
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3897/mycokeys.41.28130DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6194138PMC
October 2018

Endothelial Extracellular Vesicles Produced by Senescent Cells: Pathophysiological Role in the Cardiovascular Disease Associated with all Types of Diabetes Mellitus.

Curr Vasc Pharmacol 2019 ;17(5):447-454

Biology Systems Department, Physiology, Alcala University, Alcala de Henares, Madrid, Spain.

Endothelial senescence-associated with aging or induced prematurely in pathological situations, such as diabetes, is a first step in the development of Cardiovascular Disease (CVDs) and particularly inflammatory cardiovascular diseases. The main mechanism that links endothelial senescence and the progression of CVDs is the production of altered Extracellular Vesicles (EVs) by senescent endothelial cells among them, Microvesicles (MVs). MVs are recognized as intercellular signaling elements that play a key role in regulating tissue homeostasis. However, MVs produced by damage cell conveyed epigenetic signals, mainly involving microRNAs, which induce many of the injured responses in other vascular cells leading to the development of CVDs. Many studies strongly support that the quantification and characterization of the MVs released by senescent endothelial cells may be useful diagnostic tools in patients with CVDs, as well as a future therapeutic target for these diseases. In this review, we summarize the current knowledge linking senescence-associated MVs to the development of CVDs and discuss the roles of these MVs, in particular, in diabetic-associated increases the risk of CVDs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2174/1570161116666180820115726DOI Listing
May 2020

Senescent Microvesicles: A Novel Advance in Molecular Mechanisms of Atherosclerotic Calcification.

Int J Mol Sci 2018 Jul 9;19(7). Epub 2018 Jul 9.

Biology Systems Department, Physiology, Alcala University, Alcala de Henares, 28805 Madrid, Spain.

Atherosclerosis, a chronic inflammatory disease that causes the most heart attacks and strokes in humans, is the leading cause of death in the developing world; its principal clinical manifestation is coronary artery disease. The development of atherosclerosis is attributed to the aging process itself (biological aging) and is also associated with the development of chronic diseases (premature aging). Both aging processes produce an increase in risk factors such as oxidative stress, endothelial dysfunction and proinflammatory cytokines (oxi-inflamm-aging) that might generate endothelial senescence associated with damage in the vascular system. Cellular senescence increases microvesicle release as carriers of molecular information, which contributes to the development and calcification of atherosclerotic plaque, as a final step in advanced atherosclerotic plaque formation. Consequently, this review aims to summarize the information gleaned to date from studies investigating how the senescent extracellular vesicles, by delivering biological signalling, contribute to atherosclerotic calcification.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms19072003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073566PMC
July 2018

Nanotechnology Applied to Preserve Extracelular Matrix as Teranostic Tool in Acute Myocardial Infarction.

Rev Esp Cardiol (Engl Ed) 2019 Feb 9;72(2):171-174. Epub 2018 Apr 9.

Servicio de Cardiología, Unidad de Investigación del Hospital Ramón y Cajal (IRYCIS)-Universidad Francisco de Vitoria, Madrid, Spain. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rec.2017.12.023DOI Listing
February 2019

EEG-Based Analysis of the Emotional Effect of Music Therapy on Palliative Care Cancer Patients.

Front Psychol 2018 2;9:254. Epub 2018 Mar 2.

Palliative Care Unit, Oncology Service, Parc de Salut Mar, Instituto Mar de Investigaciones Médicas, Barcelona, Spain.

Music is known to have the power to induce strong emotions. The present study assessed, based on Electroencephalography (EEG) data, the emotional response of terminally ill cancer patients to a music therapy intervention in a randomized controlled trial. A sample of 40 participants from the palliative care unit in the Hospital del Mar in Barcelona was randomly assigned to two groups of 20. The first group [experimental group (EG)] participated in a session of music therapy (MT), and the second group [control group (CG)] was provided with company. Based on our previous work on EEG-based emotion detection, instantaneous emotional indicators in the form of a coordinate in the arousal-valence plane were extracted from the participants' EEG data. The emotional indicators were analyzed in order to quantify (1) the overall emotional effect of MT on the patients compared to controls, and (2) the relative effect of the different MT techniques applied during each session. During each MT session, five conditions were considered: (initial patient's state before MT starts), (passive listening), (active listening), (relaxation), and (final patient's state). EEG data analysis showed a significant increase in valence ( = 0.0004) and arousal ( = 0.003) between and in the EG. No significant changes were found in the CG. This results can be interpreted as a positive emotional effect of MT in advanced cancer patients. In addition, according to pre- and post-intervention questionnaire responses, participants in the EG also showed a significant decrease in tiredness, anxiety and breathing difficulties, as well as an increase in levels of well-being. No equivalent changes were observed in the CG.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2018.00254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5840261PMC
March 2018

Thermal properties of graphene from path-integral simulations.

J Chem Phys 2018 Mar;148(10):102302

Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain.

Thermal properties of graphene monolayers are studied by path-integral molecular dynamics simulations, which take into account the quantization of vibrational modes in the crystalline membrane and allow one to consider anharmonic effects in these properties. This system was studied at temperatures in the range from 12 to 2000 K and zero external stress, by describing the interatomic interactions through the LCBOPII effective potential. We analyze the internal energy and specific heat and compare the results derived from the simulations with those yielded by a harmonic approximation for the vibrational modes. This approximation turns out to be rather precise up to temperatures of about 400 K. At higher temperatures, we observe an influence of the elastic energy due to the thermal expansion of the graphene sheet. Zero-point and thermal effects on the in-plane and "real" surface of graphene are discussed. The thermal expansion coefficient α of the real area is found to be positive at all temperatures, in contrast to the expansion coefficient α of the in-plane area, which is negative at low temperatures and becomes positive for T ≳ 1000 K.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4997178DOI Listing
March 2018