Article
Physics, Fluids & Plasmas
Alessandro Loppini, Alessandro Barone, Alessio Gizzi, Christian Cherubini, Flavio H. Fenton, Simonetta Filippi
Summary: Alternans of cardiac action potential duration is a critical precursor for life-threatening arrhythmias and sudden cardiac death, influenced by the system's thermal state. Lowering temperature results in a decrease in characteristic length, confirming the impact of thermal instabilities on cardiac dynamics. The extracted characteristic length may serve as a potential predictive index for cardiac alternans onset and evolution across various system states.
Article
Physics, Fluids & Plasmas
Chunli Huang, Zhen Song, Zhilin Qu
Summary: This paper investigates the complex dynamics of action potential and calcium cycling in the heart, resulting from the bidirectional coupling of membrane voltage and calcium. The results show that when the calcium subsystem is stable, the calcium dynamics always follow the dynamics of the action potential, leading to synchronization. When the calcium subsystem is unstable, the synchronization of the two subsystems depends on their stabilities, coupling strengths, and the spatial scales of the initial calcium patterns. The synchronized patterns can exhibit different phase relationships.
Article
Physiology
Juan Ignacio Elio Mariangelo, Gabriel Dario Di Marzio, Luis Alberto Gonano, Matilde Said, Cecilia Mundina-Weilenmann
Summary: This study investigates the effects of hypertrophy and hypertension on cardiac alternans, finding that rats with hypertrophic myocardium are more prone to high-frequency mechanical and Ca2+ alternans. Subcellular Ca2+ alternans is also observed. It is suggested that tuning the refractoriness of SR Ca2+ release may prevent cardiac alternans in hypertrophic myocardium with adverse T-tubule remodeling.
Article
Computer Science, Information Systems
Massimo W. Rivolta, Juan Pablo Martinez, Roberto Sassi, Pablo Laguna
Summary: Using a biophysical model of the ECG, this study demonstrates that T-wave alternans (TWA) is significantly driven by the spatial covariance between myocytes' repolarization time and alternans, rather than global alternans. This finding provides new insights into the mechanisms underlying TWA.
IEEE JOURNAL OF BIOMEDICAL AND HEALTH INFORMATICS
(2022)
Article
Physics, Fluids & Plasmas
Niels F. Otani, Eileen Figueroa, James Garrison, Michelle Hewson, Laura Munoz, Flavio H. Fenton, Alain Karma, Seth H. Weinberg
Summary: Discordant alternans, the spatially out-of-phase alternation of action potentials durations in the heart, is linked to the onset of fibrillation. Computer models have struggled to reproduce the small domain sizes and rapid action potential propagation speeds seen in experiments. This study shows that a more detailed model of intercellular coupling that accounts for ephaptic effects can achieve rapid wave speeds and small domain sizes.
Article
Optics
Yongjin Sung, Weizhong Wang
Summary: We present the implementation of hyperspectral confocal microscopy in the short-wave infrared (SWIR) range using a wavelength-scanning laser combined with laser scanning confocal microscopy. The SWIR confocal microscopy enables high-resolution inspection of an IC chip, and the combination of hyperspectral imaging and chemometric analysis allows for identification of functional circuit block groups in the acquired image. The developed instrument has the potential for inline inspection and non-invasive failure analysis of IC chips.
Article
Physics, Multidisciplinary
Niels F. Otani, Eileen Figueroa, James Garrison, Michelle Hewson, Laura Munoz, Flavio H. Fenton, Alain Karma, Seth H. Weinberg
Summary: Previous computer simulations have shown that existing models of action potential wave propagation in the heart do not match observed wave propagation behavior. However, we have found that this discrepancy can be resolved by introducing ephaptic coupling as a primary factor in wave front propagation. This not only provides support for the importance of ephaptic coupling in normal wave propagation, but also helps to explain the discordant alternans patterns observed in experiments.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Noemi Toth, Jozefina Szlovak, Zsofia Kohajda, Gergo Bitay, Roland Veress, Balazs Horvath, Julius Gy. Papp, Andras Varro, Norbert Nagy
Summary: Recent studies have shown that action potential restitution slope is not a sufficient predictor for the development of cardiac alternans, and membrane potential may play a role in this mechanism. The contribution of I-CaL to shaping the fast phase of the restitution curve was found to be minor, suggesting that it may affect the reliability of APD restitution slope in predicting alternans.
SCIENTIFIC REPORTS
(2021)
Review
Physiology
Tingting You, Cunjin Luo, Kevin Zhang, Henggui Zhang
Summary: T-wave alternans (TWA) reflects alternating changes in the morphology of the electrocardiogram ST segment or T wave every other beat in the setting of a constant heart rate, and is used as a non-invasive marker for predicting the risk of malignant cardiac arrhythmias and sudden cardiac death. This review aims to elucidate possible mechanisms underlying the genesis of TWA at the cellular level, as well as the transition to cardiac arrhythmia, and discuss progress and future perspectives in antiarrhythmic therapies associated with TWA.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Physics, Fluids & Plasmas
Tuhin Subhra Das, Dan Wilson
Summary: Phase-isostable reduction is an emerging model reduction strategy that accurately replicates nonlinear behaviors, especially in systems where standard phase reduction techniques fail. By deriving relationships between reduced isostable coordinates' variance and proposing a data-driven technique, the study successfully infers nonlinear terms in the phase-isostable coordinate reduction framework, applying this strategy to solve the issue of cardiac alternans.
Article
Mathematics, Applied
Marko Sterk, Jurij Dolensek, Lidija Krizancic Bombek, Rene Markovic, Darko Zakelsek, Matjaz Perc, Viljem Pohorec, Andraz Stozer, Marko Gosak
Summary: The functionality of pancreatic islets can be characterized by the position of wave initiator regions and the velocity of spreading calcium waves. Mathematical modeling can help improve the determination of these parameters and reveal that calcium waves are primarily triggered by specific regions, with a velocity of around 80 μm/s.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Engineering, Biomedical
Ilaria Marcantoni, Agnese Sbrollini, Micaela Morettini, Cees A. Swenne, Laura Burattini
Summary: The EAMF method can accurately identify and measure all types of simulated alternans, as well as different alternans types present simultaneously in experimental data. It is able to distinguish TWA as the prevalent type and may aid in determining the incremental clinical utility of PWA and QRSA with respect to TWA.
BIOMEDICAL SIGNAL PROCESSING AND CONTROL
(2021)
Article
Medicine, Research & Experimental
Alvaro Teijeira, Itziar Migueliz, Saray Garasa, Vaios Karanikas, Carlos Luri, Asunta Cirella, Irene Olivera, Marta Canamero, Maite Alvarez, Maria C. Ochoa, Ana Rouzaut, Maria E. Rodriguez-Ruiz, Miguel F. Sanmamed, Christian Klein, Pablo Umana, Mariano Ponz, Marina Bacac, Ignacio Melero
Summary: In this study, the performance of the CEA-CD3 T cell bispecific antibody cibisatamab in three-dimensional tumor organoids cocultured with T cells was investigated using time-lapse confocal microscopy. The results showed that the killing of tumor cells was dependent on the levels of surface CEA expression, and the higher affinity CEACAM5-CD3 bispecific antibody remained active on low CEA expressing organoids. Additionally, the coculture of tumor organoids, autologous fibroblasts, and T cells demonstrated a costimulatory effect of anti-FAP-4-1BBL antibody, leading to enhanced tumor cell killing.
Article
Chemistry, Physical
Mateusz Kotkowiak, Adam Piasecki
Summary: Nickel composites doped with chromium and calcium fluoride were synthesized using powder metallurgy. The friction coefficient of samples with 20% CaF2 was lower at high temperatures (600 degrees C) compared to a Ni-50%NiCr(80/20) composite. Analysis of the sample surfaces revealed the formation of a tribofilm, and wear tests showed that the presence of the tribofilm reduced wear in the frictional pair.
Article
Cardiac & Cardiovascular Systems
Datun Qi, Wei Li, Xiao-Qing Quan, Yuan Gao, Jianyong Wang, Lily Guo, Wenping Zhao, Tong Liu, Chuanyu Gao, Gan-Xin Yan
Summary: This study found that left ventricular hypertrophy increases the density of late sodium current, leading to early afterdepolarizations in the left ventricular endocardium and resulting in macroscopic T wave alternans and mechanical alternans. INa-L blockers can eliminate macroscopic T wave alternans, mechanical alternans, early afterdepolarization-induced R-T extrasystoles, and Torsades de Pointes.
CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY
(2023)
Article
Clinical Neurology
Sen Sheng, Rohan Sharma, Rohan Samant, Junliang Yuan, Krishna Nalleballe, Nidhi Kapoor
Summary: Isolated neurolymphomatosis of cranial multineuritis is a rare condition with lymphomatous invasion of cranial nerves only. A 63-year-old female patient presented with a wide range of syndromes and was found to have large atypical B cells in CSF cytology suspicious for non-Hodgkin lymphoma. Treatment with methotrexate-based chemotherapy led to symptom resolution and complete radiographic response without the need for whole-brain radiation or transplantation.
NEUROLOGICAL SCIENCES
(2021)
Editorial Material
Cardiac & Cardiovascular Systems
Alan Kadish, Jason Jacobson
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
(2021)
Article
Clinical Neurology
Hisham Elkhider, Rohan Sharma, Nidhi Kapoor, Surjith Vattoth, Bashir Shihabuddin
Summary: Antibody-mediated encephalitides are a group of inflammatory brain diseases characterized by prominent neuropsychiatric symptoms and associated with antibodies against neuronal cell-surface proteins. Diagnosis involves evaluating clinical presentation, brain imaging, cerebrospinal fluid findings, antibody detection, and EEG results. Early diagnosis is crucial to avoid delays in treatment.
NEUROLOGICAL SCIENCES
(2022)
Article
Urology & Nephrology
Abhijit Patil, Rohan Sharma, Darshit Shah, Ankit Gupta, Abhishek Singh, Arvind Ganpule, Ravindra Sabnis, Mahesh Desai
Summary: The study compared the efficiency and outcomes of Trilogy (TM) and Thulium fibre laser (TFL) in mini-percutaneous nephrolithotomy (mini-PCNL), showing that Trilogy had significantly better stone fragmentation rate than TFL, but stone-free rates and complications were comparable between the two techniques.
WORLD JOURNAL OF UROLOGY
(2022)
Review
Medicine, General & Internal
Rohan Sharma, Krishna Nalleballe, Vishank Shah, Shilpa Haldal, Thomas Spradley, Lana Hasan, Krishna Mylavarapu, Keyur Vyas, Manoj Kumar, Sanjeeva Onteddu, Murat Gokden, Nidhi Kapoor
Summary: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global pandemic that has caused millions of deaths worldwide. Hemorrhagic encephalitis is a serious complication of COVID-19, with a multifactorial etiology and varied clinical manifestations. Some patients have self-limiting conditions, while others experience more severe systemic illnesses and multiple infections.
Article
Cardiac & Cardiovascular Systems
Danon Kaewkes, Vivek Patel, Tomoki Ochiai, Nir Flint, Keita Koseki, Ofir Koren, Rohan Sharma, Jeffrey Tyler, Yeunjung Kim, Siddharth Singh, Moody Makar, Tarun Chakravarty, Mamoo Nakamura, Raj Makkar
Summary: In patients with secondary mitral regurgitation undergoing the MitraClip procedure, preprocedural MDCT parameters, specifically the MVOA/MAA ratio and MLC, can be useful predictors of postprocedural residual MR.
JOURNAL OF CARDIOLOGY
(2022)
Article
Biochemical Research Methods
Timothy R. Blake, Ole A. W. Haabeth, Adrienne Sallets, Rebecca L. McClellan, Trevor J. Del Castillo, Jose G. Vilches-Moure, Wilson C. Ho, Paul A. Wender, Ronald Levy, Robert M. Waymouth
Summary: Targeted delivery of nucleic acid therapeutics to the lungs shows promise for treating pulmonary diseases. New lysine-derived CART-mRNA complexes (K-CARTs/mRNA) demonstrate selective protein expression in the lungs without additives or targeting ligands. The ability to direct protein expression selectively in the spleen or lungs by simple changes to the CART structure opens new opportunities in research and gene therapy.
BIOCONJUGATE CHEMISTRY
(2023)
Article
Microbiology
Edward G. Barrett, David Revelli, Chandra Shekhar Bakshi, Alan Kadish, Salomon Amar
Summary: The COVID-19 pandemic has caused over 6.7 million deaths worldwide. Vaccines administered via injection have reduced the severity of infections and mortality rates. However, there is interest in developing mucosally delivered vaccines for improved vaccination. This study compared immune responses in hamsters immunized with live SARS-CoV-2 via injection or intranasal delivery and found that intranasal immunization induced a stronger immune response and better protection against respiratory infection.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Medicine, General & Internal
Rohan Sharma, Akilandeswari Aravindhan, Clara Puente, Aravindhan Veerapandiyan
Summary: Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a genetic neurological disorder characterized by progressive cerebellar ataxia, spasticity, and peripheral neuropathy. Diagnosis can be challenging due to atypical presentations and the presence of various symptoms. Genetic analysis and clinical evaluation are important tools for accurate diagnosis.
JOURNAL OF INVESTIGATIVE MEDICINE HIGH IMPACT CASE REPORTS
(2022)
Meeting Abstract
Clinical Neurology
Rohan Sharma, Nidhi Kapoor, Krishna Nalleballe, Vishank Shah, Shilpa Haldal, Sanjeeva Onteddu, Krishna Mylavarapu, Thomas Spradley, Lana Hasan, Murat Gokden, Manoj Kumar
Article
Engineering, Aerospace
Rohan Sharma, Kishan Patel, Sanyami Shah, Michal Aibin
Summary: This paper proposes a method using computer vision algorithms to improve railway maintenance, specifically by using aerial footage and the YOLO algorithm to identify points of interest. The results show a high accuracy in detecting missing ties, vegetation, and water pooling.
Article
Medicine, General & Internal
Rohan Sharma, Christian Ponder, Mudassar Kamran, Joseph Chacko, Nidhi Kapoor, Krishna Mylavarapu, Sanjeeva Onteddu, Krishna Nalleballe
Summary: Carotid-cavernous fistula (CCF) is an abnormal connection between the carotid artery and the cavernous sinus. Most cases are caused by head trauma, but this report presents a case of bilateral CCF without history of trauma, suggesting a spontaneous form. Diagnosis was challenging due to its rarity, but clinical features such as headache, signs of increased intracranial pressure, and eye-related symptoms led to suspicion of CCF. The gold standard diagnostic tool, 4-vessel angiography, confirmed the diagnosis and successful treatment was achieved with endovascular coil embolization.
JOURNAL OF INVESTIGATIVE MEDICINE HIGH IMPACT CASE REPORTS
(2022)
Article
Health Care Sciences & Services
Hisham Elkhider, Rohan Sharma, Sen Sheng, Jeff Thostenson, Nidhi Kapoor, Poornachand Veerapaneni, Suman Siddamreddy, Faisal Ibrahim, Sisira Yadala, Sanjeeva Onteddu, Krishna Nalleballe
Summary: This study aims to identify predictors of patients who miss appointments in neurology clinics. The results show that younger age, female gender, Black/African American race, longer lead time to appointments, Medicaid/Medicare insurance, and certain subspecialties (resident and stroke clinics) are associated with higher odds of no show. The suggested interventions include better communication, flexible appointments, and telemedicine.
Meeting Abstract
Rheumatology
Eric Yen, Snehin Rajkumar, Rohan Sharma, Ram Singh
ARTHRITIS & RHEUMATOLOGY
(2021)
Article
Cardiac & Cardiovascular Systems
Ramkumar V. Venkateswaran, M. V. Moorthy, Neal A. Chatterjee, Julie Pester, Alan H. Kadish, Daniel C. Lee, Nancy R. Cook, Christine M. Albert
Summary: In patients with coronary artery disease and left ventricular ejection fraction of >30% to 35%, those with diabetes mellitus and/or elevated HbA1c are at a much higher absolute risk of non-sudden/arrhythmic death compared to sudden/arrhythmic death. Clinical risk markers, rather than HbA1c, are associated with sudden/arrhythmic death risk in patients with diabetes mellitus.
JACC-CLINICAL ELECTROPHYSIOLOGY
(2021)
