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Jero SE, Ramakrishnan S. Analysis of Muscle Fatigue Conditions in Surface EMG Signal with A Novel Hilbert Marginal Spectrum Entropy Method. Annu Int Conf IEEE Eng Med Biol Soc 2019; 2019:2675-2678. [PMID: 31946446 DOI: 10.1109/embc.2019.8857077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Surface Electromyogram is the superposition of action potentials generated during muscle contraction that provides useful indices for biomechanics. Such signals are nonstationary and the measure of its time varying components are essentially needed to identify the progression of fatigue. In this work, an attempt has been made to identify the muscle fatigue condition using Hilbert-Huang Marginal Spectrum. The novelty of the proposed framework is that the Marginal Spectrum is computed by ordering the instantaneous frequency of an Intrinsic Mode Function obtained for a signal to be analyzed. For this purpose, signals are recorded from the biceps brachii muscles of 50 healthy volunteers using isometric and dynamic contraction exercise protocols. Initially, each signal is equally partitioned into 10 segments, where the 1st, 5th and 10th segments are analyzed. Further, metrics estimated from marginal spectrum such as area under the curve, skewness and kurtosis are calculated for the considered three segments. The preliminary results show that the estimated metrics are able to distinguish the fatiguing conditions. The recorded signals show low amplitude and high frequencies in nonfatigue region and vice-versa. The obtained results are statistically significant with p <; 0.005. It appears that the instantaneous frequency based marginal spectrum estimator is able to measure the fatigue index. Therefore, the proposed method can be useful in analyzing fatigue condition of skeletal muscles.
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de Haydu C, Ramakrishnan V, Ban Y, Schlumbrecht M, Roy S, Ramakrishnan S. How does microbiome change with chemotherapy? Using an in vivo model of uterine cancer to assess changes in gut microbiome. Gynecol Oncol 2019. [DOI: 10.1016/j.ygyno.2019.03.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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53
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de Haydu C, Ramakrishnan V, Ban Y, Zhang L, Schlumbrecht M, Roy S, Ramakrishnan S. How does microbiome change with chemotherapy? Using an i model of uterine cancer to assess changes in gut microbiome. Gynecol Oncol 2019. [DOI: 10.1016/j.ygyno.2019.04.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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54
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Rohini P, Sundar S, Ramakrishnan S. Characterization of Alzheimer conditions in MR images using volumetric and sagittal brainstem texture features. Comput Methods Programs Biomed 2019; 173:147-155. [PMID: 31046989 DOI: 10.1016/j.cmpb.2019.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 02/17/2019] [Accepted: 03/06/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND OBJECTIVE Brainstem analysis in Magnetic Resonance Images is essential to detect Alzheimer's condition in the preclinical stages. In this work, an attempt has been made to segment the brainstem in sagittal (2D) and volumetric (3D) images and evaluate texture changes to differentiate Alzheimer's disease (AD) stages. METHOD The images obtained from a public access database are spatial normalized, skull stripped and contrast enhanced. Morphological Reconstruction based Fast and Robust Fuzzy 'C' Means technique is used to cluster the brain tissue in preprocessed images into three groups namely cerebrospinal fluid, grey matter and white matter. Brainstem is segmented from the white matter tissue using connected component labelling. Texture features from volumetric and sagittal brainstem slices are extracted and its statistical significance is evaluated. RESULTS Results show that the proposed approach is able to segment the brainstem from all the considered images. Variation in texture is observed to be less than 2% among sagittal brainstem slices. Additionally, midsagittal and volumetric features are correlated, suggesting that midsagittal brainstem structure gives an estimate of brainstem volume. Texture features extracted from midsagittal slice shows significant variation (p < 0.05) and is able to differentiate AD classes. CONCLUSION Midsagittal brainstem texture features are able to capture the changes occurring in the early stages of disease condition. As the distinction of AD in preclinical stage is complex and clinically significant, this approach could be useful for early diagnosis of the disease.
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Affiliation(s)
- P Rohini
- Non-Invasive Imaging and Diagnostic Laboratory, Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, 600036, India.
| | - S Sundar
- Department of Mathematics, Indian Institute of Technology Madras, 600036, India.
| | - S Ramakrishnan
- Non-Invasive Imaging and Diagnostic Laboratory, Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, 600036, India.
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Ferrarelli F, Kaskie R, Laxminarayan S, Ramakrishnan S, Reifman J, Germain A. An increase in sleep slow waves predicts better working memory performance in healthy individuals. Neuroimage 2019; 191:1-9. [DOI: 10.1016/j.neuroimage.2019.02.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 01/14/2019] [Accepted: 02/07/2019] [Indexed: 11/16/2022] Open
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Vital-Lopez F, Ramakrishnan S, Doty TJ, Balkin TJ, Reifman J. 0206 Personalized Caffeine Recommendations To Maintain Alertness: You And I Need Different Doses. Sleep 2019. [DOI: 10.1093/sleep/zsz067.205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Francisco Vital-Lopez
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Sridhar Ramakrishnan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Tracy J Doty
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Thomas J Balkin
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Jaques Reifman
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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57
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Wang C, Ramakrishnan S, Laxminarayan S, Dovzhenok A, Germain A, Reifman J. 0074 Can We Identify Reproducible Brain-activity Markers Of PTSD During Sleep? Sleep 2019. [DOI: 10.1093/sleep/zsz067.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chao Wang
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Sridhar Ramakrishnan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Srinivas Laxminarayan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Andrey Dovzhenok
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Anne Germain
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jaques Reifman
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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58
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Khan H, Wallace MJ, Laxminarayan S, Ramakrishnan S, Reifman J, Germain A. 0172 Effects of Daytime Sleepiness on Working Memory Performance in Veterans With and Without PTSD. Sleep 2019. [DOI: 10.1093/sleep/zsz067.171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hassen Khan
- University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | | | - Srinivas Laxminarayan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD, USA
| | - Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD, USA
| | - Anne Germain
- Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
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LaGoy AD, Sphar M, Connaboy C, Dretsch M, Laxminarayan S, Ramakrishnan S, Reifman J, Germain A. 0184 Predicting Daytime Sleepiness from Nighttime Sleep in Veterans With and Without PTSD. Sleep 2019. [DOI: 10.1093/sleep/zsz067.183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Margaret Sphar
- University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | | | - Michael Dretsch
- US Army Medical Research Directorate-West, JB Lewis-McChord, WA, USA
| | - Srinivas Laxminarayan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD, USA
| | - Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD, USA
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Laxminarayan S, Ramakrishnan S, Wang C, Germain A, Reifman J. 0883 EEG Connectivity Markers In Combat-exposed Veterans With PTSD. Sleep 2019. [DOI: 10.1093/sleep/zsz067.881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Srinivas Laxminarayan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Sridhar Ramakrishnan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Chao Wang
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Anne Germain
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jaques Reifman
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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61
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Kumar K, Vital-Lopez F, Ramakrishnan S, Doty TJ, Balkin TJ, Reifman J. 0324 2B-Alert Web 2.0: An Open-access Tool to Determine Caffeine Doses That Optimize Alertness. Sleep 2019. [DOI: 10.1093/sleep/zsz067.323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Kamal Kumar
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Francisco Vital-Lopez
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Sridhar Ramakrishnan
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
| | - Tracy J Doty
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Thomas J Balkin
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Jaques Reifman
- DoD Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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Ramakrishnan S, Karuppannan M, Vinothkannan M, Ramachandran K, Kwon OJ, Yoo DJ. Ultrafine Pt Nanoparticles Stabilized by MoS 2/N-Doped Reduced Graphene Oxide as a Durable Electrocatalyst for Alcohol Oxidation and Oxygen Reduction Reactions. ACS Appl Mater Interfaces 2019; 11:12504-12515. [PMID: 30848889 DOI: 10.1021/acsami.9b00192] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Direct alcohol fuel cells play a pivotal role in the synthesis of catalysts because of their low cost, high catalytic activity, and long durability in half-cell reactions, which include anode (alcohol oxidation) and cathode (oxygen reduction) reactions. However, platinum catalysts suffer from CO tolerance, which affects their stability. The present study focuses on ultrafine Pt nanoparticles stabilized by flowerlike MoS2/N-doped reduced graphene oxide (Pt@MoS2/NrGO) architecture, developed via a facile and cost-competitive approach that was performed through the hydrothermal method followed by the wet-reflux strategy. Fourier transform infrared spectra, X-ray diffraction patterns, Raman spectra, X-ray photoelectron spectra, field-emission scanning electron microscopy, and transmission electron microscopy verified the conversion to Pt@MoS2/NrGO. Pt@MoS2/NrGO was applied as a potential electrocatalyst toward the anode reaction (liquid fuel oxidation) and the cathode reaction (oxygen reduction). In the anode reaction, Pt@MoS2/NrGO showed superior activity toward electro-oxidation of methanol, ethylene glycol, and glycerol with mass activities of 448.0, 158.0, and 147.0 mA/mgPt, respectively, approximately 4.14, 2.82, and 3.34 times that of a commercial Pt-C (20%) catalyst. The durability of the Pt@MoS2/NrGO catalyst was tested via 500 potential cycles, demonstrating less than 20% of catalytic activity loss for alcohol fuels. In the cathode reaction, oxygen reduction reaction results showed excellent catalytic activity with higher half-wave potential at 0.895 V versus a reversible hydrogen electrode for Pt@MoS2/NrGO. The durability of the Pt@MoS2/NrGO catalyst was tested via 30 000 potential cycles and showed only 15 mV reduction in the half-wave potential, whereas the Pt@NrGO and Pt-C catalysts experienced a much greater shift (Pt@NrGO, ∼23 mV; Pt-C, ∼20 mV).
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Affiliation(s)
| | - Mohanraju Karuppannan
- Department of Energy and Chemical Engineering , Incheon National University , 119 Academy-ro , Yeonsu-Gu, Incheon 22012 , Republic of Korea
| | | | | | - Oh Joong Kwon
- Department of Energy and Chemical Engineering , Incheon National University , 119 Academy-ro , Yeonsu-Gu, Incheon 22012 , Republic of Korea
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Senthilkumar R, Raj SM, Ramakrishnan S, Kumaresan D, Kothurkar NK. Thermally Reduced Graphene Oxide as a Counter Electrode Material for Dye-Sensitized Solar Cells. J Nanosci Nanotechnol 2019; 19:2158-2165. [PMID: 30486960 DOI: 10.1166/jnn.2019.16360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this present study, a highly conductive thermally reduced graphene oxide (TRGO) was synthesized by a low temperature thermal reduction method using RF heating, under an argon-hydrogen atmosphere. The crystallinity and morphology were examined by X-ray diffraction, Raman spectroscopy and TEM analysis. The chemical structure including the functional groups present on TRGO was studied using X-ray photoelectron spectroscopy and FTIR analysis. The studies reveal that thermal reduction of graphene oxide was successful under the experimental conditions and that the TRGO had high crystallinity. Further, the performance of the as-prepared TRGO was tested as a counter electrode (CE) in a dye-sensitized solar cell (DSSC). The maximum power conversion efficiency (PCE) obtained was 4.86% for TRGO under one sun illumination, which is comparable to that of a platinum CE-based DSSC (5.24%). The electrocatalytic activity and electron transfer kinetics were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel measurements. The series resistance (Rs) and charge transfer resistance (Rct) values were found to be 35.4 Ωcm-2 and 56.40 Ωcm-2 for TRGO. The results reveal that the TRGO had an electrocatalytic performance similar to that of Pt, making TRGO-CEs promising alternatives to the conventional Pt-CEs in DSSCs.
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Affiliation(s)
- R Senthilkumar
- Center of Excellence in Advanced Materials and Green Technologies (CoE-AMGT), Amrita School of Engineering, Coimbatore 641112, Amrita Vishwa Vidyapeetham, India
| | - S Mohan Raj
- Center of Excellence in Advanced Materials and Green Technologies (CoE-AMGT), Amrita School of Engineering, Coimbatore 641112, Amrita Vishwa Vidyapeetham, India
| | - S Ramakrishnan
- Center of Excellence in Advanced Materials and Green Technologies (CoE-AMGT), Amrita School of Engineering, Coimbatore 641112, Amrita Vishwa Vidyapeetham, India
| | - Duraisamy Kumaresan
- Center of Excellence in Advanced Materials and Green Technologies (CoE-AMGT), Amrita School of Engineering, Coimbatore 641112, Amrita Vishwa Vidyapeetham, India
| | - Nikhil K Kothurkar
- Center of Excellence in Advanced Materials and Green Technologies (CoE-AMGT), Amrita School of Engineering, Coimbatore 641112, Amrita Vishwa Vidyapeetham, India
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64
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Hansen DA, Ramakrishnan S, Satterfield BC, Wesensten NJ, Layton ME, Reifman J, Van Dongen HPA. Randomized, double-blind, placebo-controlled, crossover study of the effects of repeated-dose caffeine on neurobehavioral performance during 48 h of total sleep deprivation. Psychopharmacology (Berl) 2019; 236:1313-1322. [PMID: 30539266 PMCID: PMC7571542 DOI: 10.1007/s00213-018-5140-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/29/2018] [Indexed: 12/11/2022]
Abstract
RATIONALE Caffeine is widely used as a countermeasure against neurobehavioral impairment during sleep deprivation. However, little is known about the pharmacodynamic profile of caffeine administered repeatedly during total sleep deprivation. OBJECTIVES To investigate the effects of repeated caffeine dosing on neurobehavioral performance during sleep deprivation, we conducted a laboratory-based, randomized, double-blind, placebo-controlled, crossover, multi-dose study of repeated caffeine administration during 48 h of sleep deprivation. Twelve healthy adults (mean age 27.4 years, six women) completed an 18-consecutive-day in-laboratory study consisting of three 48 h total sleep deprivation periods separated by 3-day recovery periods. During each sleep deprivation period, subjects were awakened at 07:00 and administered caffeine gum (0, 200, or 300 mg) at 6, 18, 30, and 42 h of wakefulness. The Psychomotor Vigilance Test and Karolinska Sleepiness Scale were administered every 2 h. RESULTS The 200 and 300 mg doses of caffeine mitigated neurobehavioral impairment across the sleep deprivation period, approaching two-fold performance improvements relative to placebo immediately after the nighttime gum administrations. No substantive differences were noted between the 200 mg and 300 mg caffeine doses, and adverse effects were minimal. CONCLUSIONS The neurobehavioral effects of repeated caffeine dosing during sleep deprivation were most evident during the circadian alertness trough (i.e., at night). The difference between the 200 mg and 300 mg doses, in terms of the mitigation of performance impairment, was small. Neither caffeine dose fully restored performance to well-rested levels. These findings inform the development of biomathematical models that more accurately account for the time of day and sleep pressure-dependent effects of caffeine on neurobehavioral performance during sleep loss.
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Affiliation(s)
- Devon A Hansen
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA.
| | - Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research, US Army Medical Research and Materiel Command, Fort Detrick, Frederick, MD, USA
| | - Brieann C Satterfield
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Nancy J Wesensten
- Air Traffic Organization, Federal Aviation Administration, Washington, DC, USA
| | - Matthew E Layton
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research, US Army Medical Research and Materiel Command, Fort Detrick, Frederick, MD, USA
| | - Hans P A Van Dongen
- Sleep and Performance Research Center and Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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Abstract
In this study, an attempt has been made to identify the origin of multifractality in uterine electromyography signals and to differentiate term (gestational age > 37 weeks) and preterm (gestational age ≤ 37 weeks) conditions by multifractal detrended moving average technique. The signals obtained from a publicly available database, recorded from the abdominal surface during the second trimester, are used in this study. The signals are preprocessed and converted to shuffle and surrogate series to examine the source of multifractality. Multifractal detrended moving average algorithm is applied on all the signals. The presence of multifractality is verified using scaling exponents, and multifractal spectral features are extracted from the spectrum. The variation of multifractal features in term and preterm conditions is analyzed statistically using Student's t-test. The results of scaling exponents show that the uterine electromyography or electrohysterography signals reveal multifractal characteristics in term and preterm conditions. Further investigation indicates the existence of long-range correlation as the primary source of multifractality. Among all extracted features, strength of multifractality, exponent index, and maximum and peak singularity exponents are statistically significant ( p < 0.05) in differentiating term and preterm conditions. The coefficient of variation is found to be lower for strength of multifractality and peak singularity exponent, which reveal that these features exhibit less inter-subject variance. Hence, it appears that multifractal analysis can aid in the diagnosis of preterm or term delivery of pregnant women.
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Affiliation(s)
- N Punitha
- Non-Invasive Imaging and Diagnostic (NIID) Laboratory, Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - S Ramakrishnan
- Non-Invasive Imaging and Diagnostic (NIID) Laboratory, Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
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Dadsena R, P R, Ramakrishnan S. Proposal of a Machine Learning Approach to Differentiate Mild and Alzheimer's Condition in MR Images Using Shape Changes in Corpus Callosum. Stud Health Technol Inform 2019; 258:243-244. [PMID: 30942758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The brain ventricles are surrounded by periventricular structures that are affected by dementia which results in neurodegenerative disorder such as Alzheimer's Disease (AD). The change in morphology of these structures must effect the shape and volume of Corpus Callosum (CC). These alterations in morphology of CC are considered to be a significant image biomarker for the early diagnosis of Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) subjects. Shape descriptors provide useful information about change in morphology of various brain structures during disease progression. In this work, Lattice Boltzmann criterion based hybrid level set method (LSM) is used to segment CC. Geometric and pseudo-Zernike moment measures are extracted from the segmented area of CC and are statistically analyzed using Statistical Package for Social Science (SPSS). The performance metric of significant moments is validated using machine learning algorithms. Results demonstrate that, hybrid level set is able to delineate CC and the segmented images are in high correlation with ground truth images. High accuracy value of 85.0% has been achieved using Multilayer Perceptron (MLP) classifier for Healthy Control (HC) versus AD subjects. Thus, moments are able to classify MCI from HC and AD subjects with high accuracy and hence the results are found to be clinically significant.
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Affiliation(s)
- Ravi Dadsena
- Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Rohini P
- Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - S Ramakrishnan
- Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
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67
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Sarkar R, Gowd EB, Ramakrishnan S. De-symmetrizing periodically grafted amphiphilic copolymers: design, synthesis and generation of Janus folded chains. Polym Chem 2019. [DOI: 10.1039/c9py00047j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The mutual immiscibility between the three segments, namely backbone HC, and pendant PEG and FC segments, causes zigzag folding of the polymer such that FC segments lie on one side and PEG on the other, thereby generating Janus-type folded chains.
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Affiliation(s)
- Ramkrishna Sarkar
- Department of Inorganic and Physical Chemistry
- Indian Institute of Science
- Bangalore – 560012
- India
| | - E. Bhoje Gowd
- Material Sciences and Technology Division
- CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST)
- Thiruvananthapuram – 695019
- India
| | - S. Ramakrishnan
- Department of Inorganic and Physical Chemistry
- Indian Institute of Science
- Bangalore – 560012
- India
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68
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Perala SK, Ramakrishnan S. Orthogonally clickable hyperbranched polymers: effect of reactant size and polarity on core-functionalization of peripherally jacketed HBPs. Polym Chem 2019. [DOI: 10.1039/c8py01499j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Using an orthogonally clickable strategy, the accessibility of internal allyl groups in jacketed HBPs, bearing either PEG or docosyl peripheral segments, was shown to depend both on the size and relative polarity of the reactant thiol.
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Affiliation(s)
- Suresh Kumar Perala
- Department of Inorganic and Physical Chemistry
- Indian Institute of Science
- Bangalore 560012
- India
| | - S. Ramakrishnan
- Department of Inorganic and Physical Chemistry
- Indian Institute of Science
- Bangalore 560012
- India
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69
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Saxena A, Ramakrishnan S, Roy A. PO610 The Natural History of Subclinical Rheumatic Heart Disease: Experience From North India. Glob Heart 2018. [DOI: 10.1016/j.gheart.2018.09.471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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70
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Saxena A, Ramakrishnan S, Gupta S. PO609 Mid-term Prognosis of Acute Rheumatic Carditis In Children Presenting to a Tertiary Cardiac Centre In India. Glob Heart 2018. [DOI: 10.1016/j.gheart.2018.09.470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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71
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Punitha N, Ramakrishnan S. Analysis of uterine electromyography signals in preterm condition using multifractal algorithm. Annu Int Conf IEEE Eng Med Biol Soc 2018; 2018:1-4. [PMID: 30440273 DOI: 10.1109/embc.2018.8512891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this work, an attempt has been made to analyze the preterm (gestation period $\leq 37$ weeks) condition using uterine electromyography (EMG) signals and multifractal detrended fluctuation analysis (MFDFA). The signals recorded from the electrodes placed on the surface of abdomen are used for this study and these are obtained from a publically available online database. These signals are preprocessed using 4-pole digital Butterworth filter. The preprocessed signals are subjected to MFDFA to extract multifractal features namely maximum singularity exponent, peak singularity exponent, strength of multifractality and exponent index. Generalized Hurst exponent extracted from the signals indicate that uterine EMG signals show multifractal behavior in preterm condition. Among the extracted features the coefficient of variation is found to be lower for peak singularity exponent. This indicates that this feature have lower inter-subject variability. Hence, it appears that the multifractal features can help in the assessment of uterine EMG signals for preterm detection.
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72
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Guha S, Harikrishnan S, Ray S, Sethi R, Ramakrishnan S, Banerjee S, Bahl VK, Goswami KC, Banerjee AK, Shanmugasundaram S, Kerkar PG, Seth S, Yadav R, Kapoor A, Mahajan AU, Mohanan PP, Mishra S, Deb PK, Narasimhan C, Pancholia AK, Sinha A, Pradhan A, Alagesan R, Roy A, Vora A, Saxena A, Dasbiswas A, Srinivas BC, Chattopadhyay BP, Singh BP, Balachandar J, Balakrishnan KR, Pinto B, Manjunath CN, Lanjewar CP, Jain D, Sarma D, Paul GJ, Zachariah GA, Chopra HK, Vijayalakshmi IB, Tharakan JA, Dalal JJ, Sawhney JPS, Saha J, Christopher J, Talwar KK, Chandra KS, Venugopal K, Ganguly K, Hiremath MS, Hot M, Das MK, Bardolui N, Deshpande NV, Yadava OP, Bhardwaj P, Vishwakarma P, Rajput RK, Gupta R, Somasundaram S, Routray SN, Iyengar SS, Sanjay G, Tewari S, Sengottuvelu G, Kumar S, Mookerjee S, Nair T, Mishra T, Samal UC, Kaul U, Chopra VK, Narain VS, Raj V, Lokhandwala Y. Corrigendum to "Cardiological Society of India position statement on management of heart failure in India" [Indian Heart J 70 (S1) (2018) S1-S72]. Indian Heart J 2018; 70:952-953. [PMID: 30580876 PMCID: PMC6306345 DOI: 10.1016/j.ihj.2018.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Santanu Guha
- Chairman, CSI Guidelines Committee; Medical College Kolkata, India
| | - S Harikrishnan
- Chief Coordinator, CSI HF Position Statement; Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India.
| | - Saumitra Ray
- Convenor, CSI Guidelines Committee; Vivekananda Institute of Medical Sciences, Kolkata, India
| | - Rishi Sethi
- Joint Coordinator, CSI HF Position Statement; KG Medical University, Lucknow, India
| | - S Ramakrishnan
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Suvro Banerjee
- Joint Convenor, CSI Guidelines Committee; Apollo Hospitals, Kolkata, India
| | - V K Bahl
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - K C Goswami
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Amal Kumar Banerjee
- Institute of Post Graduate Medical Education & Research, Kolkata, West Bengal, India
| | - S Shanmugasundaram
- Department of Cardiology, Tamil Nadu Medical University, Billroth Hospital, Chennai, Tamil Nadu, India
| | | | - Sandeep Seth
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Rakesh Yadav
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Aditya Kapoor
- Department of Cardiology, Sanjay Gandhi PGIMS, Lucknow, Uttar Pradesh, India
| | - Ajaykumar U Mahajan
- Department of Cardiology, Lokmanya Tilak Municipal Medical College and General Hospital, Mumbai, Maharashtra, India
| | - P P Mohanan
- Department of Cardiology, Westfort Hi Tech Hospital, Thrissur, Kerala, India
| | - Sundeep Mishra
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - P K Deb
- Daffodil Hospitals, Kolkata, West Bengal, India
| | - C Narasimhan
- Department of Cardiology & Chief of Electro Physiology Department, Care Hospitals, Hyderabad, Telangana, India
| | - A K Pancholia
- Clinical & Preventive Cardiology, Arihant Hospital & Research Centre, Indore, Madhya Pradesh, India
| | | | - Akshyaya Pradhan
- Department of Cardiology, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - R Alagesan
- The Tamil Nadu Dr.M.G.R. Medical University, Tamil Nadu, India
| | - Ambuj Roy
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Amit Vora
- Arrhythmia Associates, Mumbai, Maharashtra, India
| | - Anita Saxena
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | | | | | | | - B P Singh
- Department of Cardiology, IGIMS, Patna, Bihar, India
| | | | - K R Balakrishnan
- Cardiac Sciences, Fortis Malar Hospital, Adyar, Chennai, Tamil Nadu, India
| | - Brian Pinto
- Holy Family Hospitals, Mumbai, Maharashtra, India
| | - C N Manjunath
- Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, India
| | | | - Dharmendra Jain
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Dipak Sarma
- Cardiology & Critical Care, Jorhat Christian Medical Centre Hospital, Jorhat, Assam, India
| | - G Justin Paul
- Department of Cardiology, Madras Medical College, Chennai, Tamil Nadu, India
| | | | | | - I B Vijayalakshmi
- Bengaluru Medical College and Research Institute, Bengaluru, Karnataka, India
| | - J A Tharakan
- Department of Cardiology, P.K. Das Institute of Medical Sciences, Vaniamkulam, Palakkad, Kerala, India
| | - J J Dalal
- Kokilaben Hospital, Mumbai, Maharashtra, India
| | - J P S Sawhney
- Department of Cardiology, Dharma Vira Heart Center, Sir Ganga Ram Hospital, New Delhi, India
| | - Jayanta Saha
- Chairman, CSI Guidelines Committee; Medical College Kolkata, India
| | | | - K K Talwar
- Max Healthcare, Max Super Speciality Hospital, Saket, New Delhi, India
| | - K Sarat Chandra
- Indo-US Super Speciality Hospital & Virinchi Hospital, Hyderabad, Telangana, India
| | - K Venugopal
- Pushpagiri Institute of Medical Sciences, Tiruvalla, Kerala, India
| | - Kajal Ganguly
- Department of Cardiology, N.R.S. Medical College, Kolkata, West Bengal, India
| | | | - Milind Hot
- Department of CTVS, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Mrinal Kanti Das
- B.M. Birla Heart Research Centre & CMRI, Kolkata, West Bengal, India
| | - Neil Bardolui
- Department of Cardiology, Excelcare Hospitals, Guwahati, Assam, India
| | - Niteen V Deshpande
- Cardiac Cath Lab, Spandan Heart Institute and Research Center, Nagpur, Maharashtra, India
| | - O P Yadava
- National Heart Institute, New Delhi, India
| | - Prashant Bhardwaj
- Department of Cardiology, Military Hospital (Cardio Thoracic Centre), Pune, Maharashtra, India
| | - Pravesh Vishwakarma
- Joint Coordinator, CSI HF Position Statement; KG Medical University, Lucknow, India
| | | | - Rakesh Gupta
- JROP Institute of Echocardiography, New Delhi, India
| | | | - S N Routray
- Department of Cardiology, SCB Medical College, Cuttack, Odisha, India
| | - S S Iyengar
- Manipal Hospitals, Bangalore, Karnataka, India
| | - G Sanjay
- Chief Coordinator, CSI HF Position Statement; Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India
| | - Satyendra Tewari
- Department of Cardiology, Sanjay Gandhi PGIMS, Lucknow, Uttar Pradesh, India
| | | | - Soumitra Kumar
- Convenor, CSI Guidelines Committee; Vivekananda Institute of Medical Sciences, Kolkata, India
| | - Soura Mookerjee
- Chairman, CSI Guidelines Committee; Medical College Kolkata, India
| | - Tiny Nair
- Department of Cardiology, P.R.S. Hospital, Trivandrum, Kerala, India
| | - Trinath Mishra
- Department of Cardiology, M.K.C.G. Medical College, Behrampur, Odisha, India
| | | | - U Kaul
- Batra Heart Center & Batra Hospital and Medical Research Center, New Delhi, India
| | - V K Chopra
- Heart Failure Programme, Department of Cardiology, Medanta Medicity, Gurugram, Haryana, India
| | - V S Narain
- Joint Coordinator, CSI HF Position Statement; KG Medical University, Lucknow, India
| | - Vimal Raj
- Narayana Hrudayalaya Hospital, Bangalore, Karnataka, India
| | - Yash Lokhandwala
- Mumbai & Visiting Faculty, Sion Hospital, Mumbai, Maharashtra, India
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Abstract
Itaconic acid was readily transformed to a series of amphiphilic diesters via stepwise esterification of itaconic anhydride; the diesters carry one alkyl (cetyl or octyl) group and either a PEG, glyceryl, or dopamine segment. These diesters were used as surfmers for the preparation of polystyrene (PS) emulsions, with the expectation that the surface of the emulsion particles would carry PEG, glyceryl or dopamine units. NMR spectroscopic studies revealed that the surfmers were covalently incorporated into the polystyrene chains; furthermore, NMR tube polymerization experiments also confirmed that when the PEG surfmer was used, the PEG segments are indeed present on the surface of the emulsion particles. The size of the PEGlyated PS emulsions was readily varied from 35 to 140 nm by changing the mole fraction of surfmer used. In the case of the glyceryl and dopamine carrying surfmers, an octyl unit was used as the hydrophobic segment to ensure appropriate hydrophobic-hydrophilic balance; it was noticed that significantly larger mole fractions of the surfmers were required (15-20 mol %) to generate stable emulsions with particle sizes of about 150 nm. The PS emulsions carrying dopamine units on the surface were found to adhere to glass surfaces; thus suggesting that such "sticky" emulsion particles could be used to functionalize different types of surfaces. Finally, itaconate diesters bearing cetyl and perfluorooctyl segments were also prepared and shown to copolymerize with styrene to generate fluoroalkyl-enriched PS copolymers; these were used to generate hydrophobic coatings, with water contact angles of over 120°. Thus, itaconate-based surfmers are readily accessible alternatives for the preparation of emulsions with tailored size and surface functionality.
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Affiliation(s)
- Saheli Chakraborty
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 , India
| | - S Ramakrishnan
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 , India
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Abstract
A hyperbranched (HB) polyester carrying peripheral allyl groups was prepared by melt-condensation of a suitably designed AB2 monomer bearing two allyl ester groups and one hydroxyl group. The periphery of the hyperbranched polymer was co-clicked with two different organic thiols, namely, hexadecane thiol and 3-mercaptopropionic acid, using the thiol-ene reaction. Three different samples with varying mole fractions of the hydrophilic carboxylic acid groups were prepared; the conformational adaptability of the hyperbranched polymer backbone permitted these amphiphilic systems to form Janus structures that exhibit surfactant-like properties and, therefore, we have termed them hybrasurfs. These polymers behave like clusters of surfactants that have been stitched at the waist by the HB polymer backbone; the Langmuir isotherms revealed the formation of a monolayer, and in two of the samples having higher mole fractions of hexadecyl segments a weak inflection in the isotherm is seen. This suggests a densification, typically implying the crystallization of the alkyl segment at the air-water interface. The monolayers were transferred onto a substrate, and their heights were estimated using atomic force microscopy; the values thus obtained were in reasonable agreement with the expected value. The water contact angles of the substrates bearing the transferred monolayers of the three different samples (transferred at two different points along the isotherm) were measured; it was seen that the sample carrying the highest mole fraction of hexadecyl chains exhibited a significantly larger contact angle when compared to that of the other two samples. Interestingly, these hybrasurfs also formed vesicles in water and were shown to encapsulate water-soluble dyes, such as Eosin Y. Thus, this class of readily accessible amphiphilic HB polymers that behave as a cluster of surfactants opens some interesting possibilities for further exploration.
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Affiliation(s)
- N S Shree Varaprasad
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 , India
| | - S Ramakrishnan
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 , India
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75
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Gupta SK, Kothari SS, Ramakrishnan S, Saxena A. Large ventricular septal defect and coexisting chronic constrictive pericarditis: "reversible Eisenmenger syndrome"-5 years after corrective surgery. Catheter Cardiovasc Interv 2018; 92:E210-E211. [PMID: 28303664 DOI: 10.1002/ccd.27028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 02/17/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Saurabh Kumar Gupta
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
| | - Shyam S Kothari
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
| | - S Ramakrishnan
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
| | - Anita Saxena
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, India
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Reifman J, Ramakrishnan S, Liu J, Kapela A, Doty TJ, Balkin TJ, Kumar K, Khitrov MY. 2B-Alert App: A mobile application for real-time individualized prediction of alertness. J Sleep Res 2018; 28:e12725. [PMID: 30033688 PMCID: PMC7378949 DOI: 10.1111/jsr.12725] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/29/2018] [Accepted: 05/29/2018] [Indexed: 11/27/2022]
Abstract
Knowing how an individual responds to sleep deprivation is a requirement for developing personalized fatigue management strategies. Here we describe and validate the 2B‐Alert App, the first mobile application that progressively learns an individual’s trait‐like response to sleep deprivation in real time, to generate increasingly more accurate individualized predictions of alertness. We incorporated a Bayesian learning algorithm within the validated Unified Model of Performance to automatically and gradually adapt the model parameters to an individual after each psychomotor vigilance test. We implemented the resulting model and the psychomotor vigilance test as a smartphone application (2B‐Alert App), and prospectively validated its performance in a 62‐hr total sleep deprivation study in which 21 participants used the app to perform psychomotor vigilance tests every 3 hr and obtain real‐time individualized predictions after each test. The temporal profiles of reaction times on the app‐conducted psychomotor vigilance tests were well correlated with and as sensitive as those obtained with a previously characterized psychomotor vigilance test device. The app progressively learned each individual’s trait‐like response to sleep deprivation throughout the study, yielding increasingly more accurate predictions of alertness for the last 24 hr of total sleep deprivation as the number of psychomotor vigilance tests increased. After only 12 psychomotor vigilance tests, the accuracy of the model predictions was comparable to the peak accuracy obtained using all psychomotor vigilance tests. With the ability to make real‐time individualized predictions of the effects of sleep deprivation on future alertness, the 2B‐Alert App can be used to tailor personalized fatigue management strategies, facilitating self‐management of alertness and safety in operational and non‐operational settings.
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Affiliation(s)
- Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Jianbo Liu
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Adam Kapela
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Tracy J Doty
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Thomas J Balkin
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Kamal Kumar
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Maxim Y Khitrov
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, US Army Medical Research and Materiel Command, Fort Detrick, Maryland
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77
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Guha S, Harikrishnan S, Ray S, Sethi R, Ramakrishnan S, Banerjee S, Bahl VK, Goswami KC, Banerjee AK, Shanmugasundaram S, Kerkar PG, Seth S, Yadav R, Kapoor A, Mahajan AU, Mohanan PP, Mishra S, Deb PK, Narasimhan C, Pancholia AK, Sinha A, Pradhan A, Alagesan R, Roy A, Vora A, Saxena A, Dasbiswas A, Srinivas BC, Chattopadhyay BP, Singh BP, Balachandar J, Balakrishnan KR, Pinto B, Manjunath CN, Lanjewar CP, Jain D, Sarma D, Paul GJ, Zachariah GA, Chopra HK, Vijayalakshmi IB, Tharakan JA, Dalal JJ, Sawhney JPS, Saha J, Christopher J, Talwar KK, Chandra KS, Venugopal K, Ganguly K, Hiremath MS, Hot M, Das MK, Bardolui N, Deshpande NV, Yadava OP, Bhardwaj P, Vishwakarma P, Rajput RK, Gupta R, Somasundaram S, Routray SN, Iyengar SS, Sanjay G, Tewari S, G S, Kumar S, Mookerjee S, Nair T, Mishra T, Samal UC, Kaul U, Chopra VK, Narain VS, Raj V, Lokhandwala Y. CSI position statement on management of heart failure in India. Indian Heart J 2018; 70 Suppl 1:S1-S72. [PMID: 30122238 PMCID: PMC6097178 DOI: 10.1016/j.ihj.2018.05.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Affiliation(s)
- Santanu Guha
- Chairman, CSI Guidelines Committee; Medical College Kolkata, India
| | - S Harikrishnan
- Chief Coordinator, CSI HF Position Statement; Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India.
| | - Saumitra Ray
- Convenor, CSI Guidelines Committee; Vivekananda Institute of Medical Sciences, Kolkata
| | - Rishi Sethi
- Joint Coordinator, CSI HF Position Statement; KG Medical University, Lucknow
| | - S Ramakrishnan
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Suvro Banerjee
- Joint Convenor, CSI Guidelines Committee; Apollo Hospitals, Kolkata
| | - V K Bahl
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - K C Goswami
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Amal Kumar Banerjee
- Institute of Post Graduate Medical Education & Research, Kolkata, West Bengal, India
| | - S Shanmugasundaram
- Department of Cardiology, Tamil Nadu Medical University, Billroth Hospital, Chennai, Tamil Nadu, India
| | | | - Sandeep Seth
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Rakesh Yadav
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Aditya Kapoor
- Department of Cardiology, Sanjay Gandhi PGIMS, Lucknow, Uttar Pradesh, India
| | - Ajaykumar U Mahajan
- Department of Cardiology, LokmanyaTilak Municipal Medical College and General Hospital, Mumbai, Maharashtra, India
| | - P P Mohanan
- Department of Cardiology, Westfort Hi Tech Hospital, Thrissur, Kerala, India
| | - Sundeep Mishra
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - P K Deb
- Daffodil Hospitals, Kolkata, West Bengal, India
| | - C Narasimhan
- Department of Cardiology & Chief of Electro Physiology Department, Care Hospitals, Hyderabad, Telangana, India
| | - A K Pancholia
- Clinical & Preventive Cardiology, Arihant Hospital & Research Centre, Indore, Madhya Pradesh, India
| | | | - Akshyaya Pradhan
- Department of Cardiology, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - R Alagesan
- The Tamil Nadu Dr.M.G.R. Medical University, Tamil Nadu, India
| | - Ambuj Roy
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | - Amit Vora
- Arrhythmia Associates, Mumbai, Maharashtra, India
| | - Anita Saxena
- Joint Coordinator, CSI HF Position Statement; All India Institute of Medical Sciences, New Delhi, India
| | | | | | | | - B P Singh
- Department of Cardiology, IGIMS, Patna, Bihar, India
| | | | - K R Balakrishnan
- Cardiac Sciences, Fortis Malar Hospital, Adyar, Chennai, Tamil Nadu, India
| | - Brian Pinto
- Holy Family Hospitals, Mumbai, Maharashtra, India
| | - C N Manjunath
- Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, India
| | | | - Dharmendra Jain
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Dipak Sarma
- Cardiology & Critical Care, Jorhat Christian Medical Centre Hospital, Jorhat, Assam, India
| | - G Justin Paul
- Department of Cardiology, Madras Medical College, Chennai, Tamil Nadu, India
| | | | | | - I B Vijayalakshmi
- Bengaluru Medical College and Research Institute, Bengaluru, Karnataka, India
| | - J A Tharakan
- Department of Cardiology, P.K. Das Institute of Medical Sciences, Vaniamkulam, Palakkad, Kerala, India
| | - J J Dalal
- Kokilaben Hospital, Mumbai, Maharshtra, India
| | - J P S Sawhney
- Department of Cardiology, Dharma Vira Heart Center, Sir Ganga Ram Hospital, New Delhi, India
| | - Jayanta Saha
- Chairman, CSI Guidelines Committee; Medical College Kolkata, India
| | | | - K K Talwar
- Max Healthcare, Max Super Speciality Hospital, Saket, New Delhi, India
| | - K Sarat Chandra
- Indo-US Super Speciality Hospital & Virinchi Hospital, Hyderabad, Telangana, India
| | - K Venugopal
- Pushpagiri Institute of Medical Sciences, Tiruvalla, Kerala, India
| | - Kajal Ganguly
- Department of Cardiology, N.R.S. Medical College, Kolkata, West Bengal, India
| | | | - Milind Hot
- Department of CTVS, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Mrinal Kanti Das
- B.M. Birla Heart Research Centre & CMRI, Kolkata, West Bengal, India
| | - Neil Bardolui
- Department of Cardiology, Excelcare Hospitals, Guwahati, Assam, India
| | - Niteen V Deshpande
- Cardiac Cath Lab, Spandan Heart Institute and Research Center, Nagpur, Maharashtra, India
| | - O P Yadava
- National Heart Institute, New Delhi, India
| | - Prashant Bhardwaj
- Department of Cardiology, Military Hospital (Cardio Thoracic Centre), Pune, Maharashtra, India
| | - Pravesh Vishwakarma
- Joint Coordinator, CSI HF Position Statement; KG Medical University, Lucknow
| | | | - Rakesh Gupta
- JROP Institute of Echocardiography, New Delhi, India
| | | | - S N Routray
- Department of Cardiology, SCB Medical College, Cuttack, Odisha, India
| | - S S Iyengar
- Manipal Hospitals, Bangalore, Karnataka, India
| | - G Sanjay
- Chief Coordinator, CSI HF Position Statement; Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India
| | - Satyendra Tewari
- Department of Cardiology, Sanjay Gandhi PGIMS, Lucknow, Uttar Pradesh, India
| | | | - Soumitra Kumar
- Convenor, CSI Guidelines Committee; Vivekananda Institute of Medical Sciences, Kolkata
| | - Soura Mookerjee
- Chairman, CSI Guidelines Committee; Medical College Kolkata, India
| | - Tiny Nair
- Department of Cardiology, P.R.S. Hospital, Trivandrum, Kerala, India
| | - Trinath Mishra
- Department of Cardiology, M.K.C.G. Medical College, Behrampur, Odisha, India
| | | | - U Kaul
- Batra Heart Center & Batra Hospital and Medical Research Center, New Delhi, India
| | - V K Chopra
- Heart Failure Programme, Department of Cardiology, Medanta Medicity, Gurugram, Haryana, India
| | - V S Narain
- Joint Coordinator, CSI HF Position Statement; KG Medical University, Lucknow
| | - Vimal Raj
- Narayana Hrudayalaya Hospital, Bangalore, Karnataka, India
| | - Yash Lokhandwala
- Mumbai & Visiting Faculty, Sion Hospital, Mumbai, Maharashtra, India
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Reifman J, Kumar K, Khitrov MY, Liu J, Ramakrishnan S. PC-PVT 2.0: An updated platform for psychomotor vigilance task testing, analysis, prediction, and visualization. J Neurosci Methods 2018; 304:39-45. [DOI: 10.1016/j.jneumeth.2018.04.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/26/2018] [Accepted: 04/13/2018] [Indexed: 01/19/2023]
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de Haydu C, Ramakrishnan V, Oleas J, Kamath P, Slomovitz B, Ramakrishnan S. New use of triptolide for endometrial cancers and evaluating effectiveness in platinum resistance in vitro. Gynecol Oncol 2018. [DOI: 10.1016/j.ygyno.2018.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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80
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Arunkumar C, Ramakrishnan S. Attribute selection using fuzzy roughset based customized similarity measure for lung cancer microarray gene expression data. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.fcij.2018.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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81
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Vital‐Lopez FG, Ramakrishnan S, Doty TJ, Balkin TJ, Reifman J. Caffeine dosing strategies to optimize alertness during sleep loss. J Sleep Res 2018; 27:e12711. [DOI: 10.1111/jsr.12711] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/11/2018] [Accepted: 04/16/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Francisco G. Vital‐Lopez
- Department of Defense Biotechnology High Performance Computing Software Applications Institute Telemedicine and Advanced Technology Research Center U.S. Army Medical Research and Materiel Command Fort Detrick Maryland
| | - Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute Telemedicine and Advanced Technology Research Center U.S. Army Medical Research and Materiel Command Fort Detrick Maryland
| | - Tracy J. Doty
- Behavioral Biology Branch Walter Reed Army Institute of Research Silver Spring Maryland
| | - Thomas J. Balkin
- Behavioral Biology Branch Walter Reed Army Institute of Research Silver Spring Maryland
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute Telemedicine and Advanced Technology Research Center U.S. Army Medical Research and Materiel Command Fort Detrick Maryland
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Vital-Lopez F, Ramakrishnan S, Doty TJ, Balkin TJ, Reifman J. 0215 Caffeine Dosage Strategies that Efficiently Enhance Alertness during Sleep Loss. Sleep 2018. [DOI: 10.1093/sleep/zsy061.214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- F Vital-Lopez
- DoD Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD
| | - S Ramakrishnan
- DoD Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD
| | - T J Doty
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD
| | - T J Balkin
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD
| | - J Reifman
- DoD Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD
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Ramakrishnan S, Doty TJ, Balkin TJ, Reifman J. 0313 2B-Alert App: A Tool to Predict Individual Trait-like Responses to Sleep Loss in Real Time. Sleep 2018. [DOI: 10.1093/sleep/zsy061.312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- S Ramakrishnan
- DoD Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD
| | - T J Doty
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD
| | - T J Balkin
- Behavioral Biology Branch, Walter Reed Army Institute of Research, Silver Spring, MD
| | - J Reifman
- DoD Biotechnology High Performance Computing Software Applications Institute, Fort Detrick, MD
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Gupta A, Verma SK, Sharma R, Parakh N, Ramakrishnan S, Roy A, Singh S, Sharma G, Karthikeyan G, Naik N, Yadav R, Mishra S, Seth S, Narang R, Goswami KC, Bhargava B, Bahl VK. Clinical and angiographic profiles and six months outcomes of smokers with acute ST segment elevation myocardial infarction undergoing primary percutaneous coronary angioplasty. Indian Heart J 2018; 70:680-684. [PMID: 30392506 PMCID: PMC6205248 DOI: 10.1016/j.ihj.2018.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 01/15/2018] [Accepted: 02/28/2018] [Indexed: 12/05/2022] Open
Abstract
Background Outcomes of primary percutaneous coronary intervention (PCI) for acute STEMI (ST-segment elevation myocardial infarction) in smokers are expected to be better than non-smokers as for patients of acute STEMI with or without fibrinolytic therapy. Objectives This comparative study was designed to evaluate the outcomes of primary PCI in patients with acute STEMI in smokers and non-smokers. Clinical and angiographic profile of the two groups was also compared. Methods Over duration of two year, a total of 150 consecutive patients of acute STEMI eligible for primary PCI were enrolled and constituted the two groups [Smokers (n = 90), Non-smokers (n = 60)] of the study population. There was no difference in procedure in two groups. Results In the present study of acute STEMI, current smokers were about a decade younger than non-smokers (p value = 0.0002), majority were male (98.9% vs 56.6%) were male with a higher prevalence of hypertension and diabetes mellitus (61.67% vs 32.28% and 46.67% vs 14.44%, p = 0.001) respectively. Smokers tended to have higher thrombus burden (p = 0.06) but less multi vessel disease (p = 0.028). Thirty day and six month mortality was non-significantly higher in smokers 4.66% vs 1.33% (p = 0.261) and 5.33% vs 2.66% (p = NS) respectively. Rate of quitting smoking among smokers was 80.90% at 6 months. Conclusion The study documents that smokers with acute STEMI have similar outcomes as compared to non smokers with higher thrombus burden and lesser non culprit artery involvement. Smokers present at much younger age emphasizing the role of smoking cessation for prevention of myocardial infarction.
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Affiliation(s)
- A Gupta
- Senior Resident, Department of cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - S K Verma
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India.
| | - R Sharma
- Senior Resident, Department of cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - N Parakh
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - S Ramakrishnan
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - A Roy
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - S Singh
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - G Sharma
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - G Karthikeyan
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - N Naik
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - R Yadav
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - S Mishra
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - S Seth
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - R Narang
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - K C Goswami
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - B Bhargava
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - V K Bahl
- 7th Floor, Department of Cardiology, CTC, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
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85
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Ramakrishnan S, Brodeur G, Telotte JC. Analysis of the Long Time Behavior of Enzymatic Cellulose Hydrolysis Kinetics. International Journal of Chemical Reactor Engineering 2018. [DOI: 10.1515/ijcre-2017-0087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractEnzymatic hydrolysis of biomass to produce sugars that can be converted to fuels and other valuable chemicals, is viewed as the prime technology for utilization of this renewable resource. To accelerate technology development, models are needed that are able to accurately predict the hydrolysis rate so that reactors can be tailored to the multitude of processing conditions and substrates that can be used. Of particular interest is the ability to predict the long time conversion in the hydrolysis reaction which dictates the maximum possible sugar concentration. It is our aim in this article to develop a simple model which is able to predict the long-term conversion of cellulose to soluble sugars. Drawing on the analogy from the theory of reactions in continuous mixtures, it is shown that analysis of the long time kinetics of hydrolysis by examining the behavior of the “lump” of the reacting material results in a simple expression which is capable of predicting the kinetics. Many features of actual enzyme systems can be included in the development of the hydrolysis model, such as the large size of the enzyme molecules, adsorption onto substrate, inhibition by different factors (solvent, glucose etc.), but, when the analysis is carried out to calculate the total sugar concentration, it is shown that the equations reduce to a simple expression. Analysis of this model is given with comparison to other models and experimental data available in the literature. In addition to predicting the long-term kinetics, it is shown that the model does a surprising job of predicting the initial hydrolysis rates as well.
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86
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Karthick PA, Ghosh DM, Ramakrishnan S. Surface electromyography based muscle fatigue detection using high-resolution time-frequency methods and machine learning algorithms. Comput Methods Programs Biomed 2018; 154:45-56. [PMID: 29249346 DOI: 10.1016/j.cmpb.2017.10.024] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 09/22/2017] [Accepted: 10/29/2017] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND OBJECTIVE Surface electromyography (sEMG) based muscle fatigue research is widely preferred in sports science and occupational/rehabilitation studies due to its noninvasiveness. However, these signals are complex, multicomponent and highly nonstationary with large inter-subject variations, particularly during dynamic contractions. Hence, time-frequency based machine learning methodologies can improve the design of automated system for these signals. METHODS In this work, the analysis based on high-resolution time-frequency methods, namely, Stockwell transform (S-transform), B-distribution (BD) and extended modified B-distribution (EMBD) are proposed to differentiate the dynamic muscle nonfatigue and fatigue conditions. The nonfatigue and fatigue segments of sEMG signals recorded from the biceps brachii of 52 healthy volunteers are preprocessed and subjected to S-transform, BD and EMBD. Twelve features are extracted from each method and prominent features are selected using genetic algorithm (GA) and binary particle swarm optimization (BPSO). Five machine learning algorithms, namely, naïve Bayes, support vector machine (SVM) of polynomial and radial basis kernel, random forest and rotation forests are used for the classification. RESULTS The results show that all the proposed time-frequency distributions (TFDs) are able to show the nonstationary variations of sEMG signals. Most of the features exhibit statistically significant difference in the muscle fatigue and nonfatigue conditions. The maximum number of features (66%) is reduced by GA and BPSO for EMBD and BD-TFD respectively. The combination of EMBD- polynomial kernel based SVM is found to be most accurate (91% accuracy) in classifying the conditions with the features selected using GA. CONCLUSIONS The proposed methods are found to be capable of handling the nonstationary and multicomponent variations of sEMG signals recorded in dynamic fatiguing contractions. Particularly, the combination of EMBD- polynomial kernel based SVM could be used to detect the dynamic muscle fatigue conditions.
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Affiliation(s)
- P A Karthick
- Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India; Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
| | - Diptasree Maitra Ghosh
- Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - S Ramakrishnan
- Biomedical Engineering Group, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
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Ramakrishnan S, Jelmy EJ, Senthilkumar R, Rangarajan M, Kothurkar NK. One-Step RF-CVD Method for the Synthesis of Graphene Decorated with Metal and Metal Oxide Nanoparticles. J Nanosci Nanotechnol 2018; 18:1089-1096. [PMID: 29448538 DOI: 10.1166/jnn.2018.13961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bilayer and few layer-graphene (Gr) with noble metal (Ag and Au) and TiO2 nanoparticles were synthesized using atmospheric pressure radio frequency chemical vapor deposition (APRF-CVD). The precursors for the formation of the respective nanoparticles were dissolved in ethanol and injected into the APRF-CVD containing a Cu foil catalyst at 1000 °C. The graphene obtained had a blistered morphology similar to bubble-wrap. The bubble-like protrusions on the graphene sheet were caused by large nanoparticle clusters (~220 nm) formed below the graphene sheets. Smaller nanoparticles (10-80 nm) were also observed on top of the graphene sheets. Encapsulation of the nanoparticles with graphene, to yield core-shell particles was observed. Similarly, secondary growth of carbon nanotubes (CNTs) from the Au nanoparticles was observed. The average full width half maxima (FWHM) of 2D bands in the Raman spectra indicate that the graphene formed was predominantly bilayer graphene for Gr-TiO2 (55 ± 1.72 cm-1), and few-layer graphene for Gr-Ag (76 ± 22 cm-1) and Gr-Au (88 ± 4.7 cm-1). Raman spectroscopy also showed evidence for the doping of graphene and surface-enhanced Raman sensitivity (SERS) in the materials. These electronic properties of graphene with nanoparticles are relevant to various applications such as optoelectronics, catalysis, chemical and biological sensing.
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Affiliation(s)
- S Ramakrishnan
- Centre of Excellence in Advanced Materials and Green Technologies, Amrita School of Engineering, Amrita Vishwa Vidyapeetham University, Amrita Nagar, Ettimadai, Coimbatore 641112, Tamil Nadu, India
| | - E J Jelmy
- Centre of Excellence in Advanced Materials and Green Technologies, Amrita School of Engineering, Amrita Vishwa Vidyapeetham University, Amrita Nagar, Ettimadai, Coimbatore 641112, Tamil Nadu, India
| | - R Senthilkumar
- Centre of Excellence in Advanced Materials and Green Technologies, Amrita School of Engineering, Amrita Vishwa Vidyapeetham University, Amrita Nagar, Ettimadai, Coimbatore 641112, Tamil Nadu, India
| | - Murali Rangarajan
- Centre of Excellence in Advanced Materials and Green Technologies, Amrita School of Engineering, Amrita Vishwa Vidyapeetham University, Amrita Nagar, Ettimadai, Coimbatore 641112, Tamil Nadu, India
| | - Nikhil K Kothurkar
- Centre of Excellence in Advanced Materials and Green Technologies, Amrita School of Engineering, Amrita Vishwa Vidyapeetham University, Amrita Nagar, Ettimadai, Coimbatore 641112, Tamil Nadu, India
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Patro K, Ramakrishnan S, Kumar S, Roopa J, Dilip R. Comparison of patient and graft survival in tacrolimus versus cyclosporine-based immunosuppressive regimes in renal transplant recipients – single-center experience from South India. Indian J Transplant 2018. [DOI: 10.4103/ijot.ijot_6_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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89
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Mishra S, Mohan JC, Nair T, Chopra VK, Harikrishnan S, Guha S, Ramakrishnan S, Ray S, Sethi R, Samal UC, Sarat Chandra K, Hiremath MS, Banerjee AK, Kumar S, Das MK, Deb PK, Bahl VK. Management protocols for chronic heart failure in India. Indian Heart J 2018; 70:105-127. [PMID: 29455764 PMCID: PMC5903070 DOI: 10.1016/j.ihj.2017.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Heart failure is a common clinical syndrome and a global health priority. The burden of heart failure is increasing at an alarming rate worldwide as well as in India. Heart failure not only increases the risk of mortality, morbidity and worsens the patient's quality of life, but also puts a huge burden on the overall healthcare system. The management of heart failure has evolved over the years with the advent of new drugs and devices. This document has been developed with an objective to provide standard management guidance and simple heart failure algorithms to aid Indian clinicians in their daily practice. It would also inform the clinicians on the latest evidence in heart failure and provide guidance to recognize and diagnose chronic heart failure early and optimize management.
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Affiliation(s)
- S Mishra
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - J C Mohan
- Department of Cardiology, Fortis Hospital, Shalimar Bagh, New Delhi, 110088, India
| | - Tiny Nair
- Department of Cardiology, PRS Hospital, Thiruvananthapuram, 695002, India
| | - V K Chopra
- Department of Clinical and Preventive Cardiology, Medanta - The Medicity, Gurugram, Haryana, 122001, India
| | - S Harikrishnan
- Department of Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, India
| | - S Guha
- Department of Cardiology, Medical College, Kolkata, 700073, India
| | - S Ramakrishnan
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - S Ray
- Department of Cardiology, Vivekananda Institute of Medical Sciences, Kolkata, 70026, India
| | - R Sethi
- Department of Cardiology, King George's Medical University, Ludhiana, Uttar Pradesh, 226003, India
| | - U C Samal
- Heart Failure Subspecialty, Cardiological Society of India, Kolkata, India
| | - K Sarat Chandra
- Department of Cardiology, Institute of Post Graduate Medical Education & Research and Memorial Hospital, Kolkata, 700020, India
| | - M S Hiremath
- Department of Cardiology, Ruby Hall Clinic, Pune, 411001, India
| | - A K Banerjee
- Department of Cardiology, Institute of Post Graduate Medical Education & Research and Memorial Hospital, Kolkata, 700020, India
| | - S Kumar
- Cardiological Society of India, Kolkata, India
| | - M K Das
- Cardiological Society of India, Kolkata, India
| | - P K Deb
- Cardiological Society of India, Kolkata, India
| | - V K Bahl
- Department of Cardiology, All India Institute of Medical Sciences, New Delhi, 110029, India
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Gopichandran L, Usha P, Pathak P, Parakh N, Ramakrishnan S, Singh S. A study to evaluate the feasibility of a nurse-led follow-up clinic among postmyocardial infarction patients attending the Cardiology Outpatient Department at CN Centre, AIIMS, New Delhi. J Pract Cardiovasc Sci 2018. [DOI: 10.4103/jpcs.jpcs_52_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Ola RK, Meena CB, Ramakrishnan S, Agarwal A, Bhargava S. Detection of Left Ventricular Remodeling in Acute ST Elevation Myocardial Infarction after Primary Percutaneous Coronary Intervention by Two Dimensional and Three Dimensional Echocardiography. J Cardiovasc Echogr 2018; 28:39-44. [PMID: 29629258 PMCID: PMC5875134 DOI: 10.4103/jcecho.jcecho_32_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background Left ventricular remodeling (LVR) after ST-elevation myocardial infarction (STEMI) harbingers poor prognosis. Three-dimensional echocardiography (3DE) is more accurate than 2 D echo for the assessment of left ventricle (LV) shape. We assessed LV geometry with 3D ECHO 6 months after STEMI in patients who had primary angioplasty. Materials and Methods In this prospective study, morphological and functional analysis of LV with 3D ECHO (volumes, LVEF, 3D sphericity index [SI]) was assessed up to 7 days and 6 months in 42 STEMI patients. The LVR was considered for increase >15% of the end diastolic volume of the LV (LVEDV) 6 months after the STEMI, compared to the LVEDV up to 7 days of it. Results Sixteen (38%) patients had LVR. 3D Echocardiographic measurements up to 7 days after the acute myocardial infarction (AMI) 1-LVEDV in ventricular remodeling group was 99.8 ± 19.1 ml and in no ventricular remodeling group was 87 ± 18.2 mL (P = 0.037); 2-LVEF was 0.48 ± 0.01 and 51 ± 0.02 (P <.001); 3D-SI was 0.41 ± 0.05 and 31 ± 0.05 (P < 0.001) II-after 6 months: 1-LVEDV in remodeling group was 114.2 ± 19.5 mL and no remodeling group was 94.2 ± 18.6 (P = 0.002); 2-LVEF was 0.58 ± 0.01 and 59 ± .01 (P = 0.003); 3D-sphericity was 0.35 ± 0.05 and 28 ± .05 (P < 0.001). Conclusion LVR was observed in 38% of the patients 6 months after AMI. The 3D SI has been associated with occurrence of LVR and can differentiate patients with and without subsequent development of LVR accurately and early on its basis.
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Affiliation(s)
- Rakesh Kumar Ola
- Department of Cardiology, SMS Medical College, Jaipur, Rajasthan, India
| | | | | | - Ashish Agarwal
- Department of Cardiology, SMS Medical College, Jaipur, Rajasthan, India
| | - Smriti Bhargava
- Department of Cardiology, SMS Medical College, Jaipur, Rajasthan, India
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Abstract
The pain that patients recollect having experienced at colonoscopy is likely to influence uptake of the procedure. We used visual analogue scales to assess recollected pain shortly before discharge, and compared these scores with assessments by the endoscopist and the attending nurse. Data were complete for 426 procedures (90%). The mean perceived pain score for patients was 3.2, for endoscopists 2.8 and for nurses 3.1. On multivariate analysis, the endoscopists' assessments of pain had little predictive value over and above those of nurses, whereas nurses' assessments remained significant when adjusted for endoscopists' assessments. Nurses were more accurate than endoscopists in gauging the pain of colonoscopy. This may be because endoscopists are focused on the video monitor while nurses are focused on the patient. More active use of nurses' assessments might help keep pain to a minimum.
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Affiliation(s)
- S Ramakrishnan
- Department of Gastroenterology, University Hospital of North Durham, Durham DH1 5TW, UK.
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Affiliation(s)
- Suresh Kumar Perala
- Department of Inorganic and
Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - S. Ramakrishnan
- Department of Inorganic and
Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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94
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Ramakrishnan S, van Smaalen S. Unusual ground states in [Formula: see text] (R = rare earth; T = Rh, Ir; and X = Si, Ge, Sn): a review. Rep Prog Phys 2017; 80:116501. [PMID: 28675142 DOI: 10.1088/1361-6633/aa7d5f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Rare earth compounds of the type [Formula: see text] (R = rare earth; T = Rh, Ir, and X = Si, Ge, Sn) display a variety of phase transitions towards exotic states, including charge density waves (CDW), local moment magnetism, antiferromagnetism in the heavy fermion state, superconductivity and giant positive magnetoresistance. They support strongly correlated electron systems. In particular, R 5Ir4 [Formula: see text] (R = Dy-Lu) exhibit strong coupling CDWs with high transition temperatures, and superconductivity or magnetic ordering at lower temperatures. [Formula: see text] [Formula: see text] (R = Gd-Tm; T = Co, Rh, Ir) show multiple magnetic transitions with large magnetoresistance below the magnetic transitions. Finally, the light rare earth series [Formula: see text] [Formula: see text] (R = Ce, Pr, Nd; T = Rh, Ir) display heavy fermion behaviour (for Ce and Pr) or possess giant positive magnetoresistance (for Nd) at low temperatures. This review provides a comprehensive overview of compounds, crystal structures and phase transitions. This is followed by an in-depth discussion of the mechanisms of the phase transitions and the properties of the ordered states.
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Affiliation(s)
- S Ramakrishnan
- Tata Institute Of Fundamental Research, Bombay-400005, India
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95
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Venugopal G, Deepak P, Ghosh DM, Ramakrishnan S. Generation of synthetic surface electromyography signals under fatigue conditions for varying force inputs using feedback control algorithm. Proc Inst Mech Eng H 2017; 231:1025-1033. [PMID: 28830284 DOI: 10.1177/0954411917727307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Surface electromyography is a non-invasive technique used for recording the electrical activity of neuromuscular systems. These signals are random, complex and multi-component. There are several techniques to extract information about the force exerted by muscles during any activity. This work attempts to generate surface electromyography signals for various magnitudes of force under isometric non-fatigue and fatigue conditions using a feedback model. The model is based on existing current distribution, volume conductor relations, the feedback control algorithm for rate coding and generation of firing pattern. The result shows that synthetic surface electromyography signals are highly complex in both non-fatigue and fatigue conditions. Furthermore, surface electromyography signals have higher amplitude and lower frequency under fatigue condition. This model can be used to study the influence of various signal parameters under fatigue and non-fatigue conditions.
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Affiliation(s)
- G Venugopal
- 1 Non-Invasive Imaging and Diagnostics Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India.,2 Department of Instrumentation and Control Engineering, N. S. S. College of Engineering, Palakkad, Kerala, India
| | - P Deepak
- 2 Department of Instrumentation and Control Engineering, N. S. S. College of Engineering, Palakkad, Kerala, India
| | - Diptasree M Ghosh
- 1 Non-Invasive Imaging and Diagnostics Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - S Ramakrishnan
- 1 Non-Invasive Imaging and Diagnostics Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
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96
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Vankalakunti M, Nada R, Kumar A, Patro K, Ramakrishnan S, Rangarajan D. Circulating Monoclonal IgG1-kappa Antibodies Causing Anti-glomerular Basement Membrane Nephritis. Indian J Nephrol 2017; 27:327-329. [PMID: 28761240 PMCID: PMC5514834 DOI: 10.4103/ijn.ijn_113_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Anti-glomerular basement membrane (GBM) antibody disease is a rare but well-characterized cause of glomerulonephritis. Patients present with rapidly progressive renal failure with hemoptysis. Early diagnosis is crucial in salvaging the renal damage and life-threatening pulmonary hemorrhage. Plasmapheresis and immunosuppression is the mode of therapy. Anti-GBM antibodies are polyclonal in nature. However, rare monoclonal antibodies can cause similar destruction of glomerular capillary walls. We describe distinct combination of circulating monoclonal and anti-GBM nephritis.
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Affiliation(s)
- M Vankalakunti
- Department of Nephropathology, Manipal Hospital, Bengaluru, Karnataka, India
| | - R Nada
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - A Kumar
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - K Patro
- Department of Nephrology, NU Hospitals, Bengaluru, Karnataka, India
| | - S Ramakrishnan
- Department of Nephrology, NU Hospitals, Bengaluru, Karnataka, India
| | - D Rangarajan
- Department of Nephrology, NU Hospitals, Bengaluru, Karnataka, India
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97
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Liu J, Ramakrishnan S, Laxminarayan S, Neal M, Cashmere DJ, Germain A, Reifman J. Effects of signal artefacts on electroencephalography spectral power during sleep: quantifying the effectiveness of automated artefact-rejection algorithms. J Sleep Res 2017; 27:98-102. [DOI: 10.1111/jsr.12576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/21/2017] [Indexed: 01/23/2023]
Affiliation(s)
- Jianbo Liu
- Department of Defense Biotechnology High Performance Computing Software Applications Institute; Telemedicine and Advanced Technology Research Center; US Army Medical Research and Materiel Command; Fort Detrick MD USA
| | - Sridhar Ramakrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute; Telemedicine and Advanced Technology Research Center; US Army Medical Research and Materiel Command; Fort Detrick MD USA
| | - Srinivas Laxminarayan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute; Telemedicine and Advanced Technology Research Center; US Army Medical Research and Materiel Command; Fort Detrick MD USA
| | - Maxwell Neal
- Department of Defense Biotechnology High Performance Computing Software Applications Institute; Telemedicine and Advanced Technology Research Center; US Army Medical Research and Materiel Command; Fort Detrick MD USA
| | | | - Anne Germain
- Department of Psychiatry; University of Pittsburgh School of Medicine; Pittsburgh PA USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute; Telemedicine and Advanced Technology Research Center; US Army Medical Research and Materiel Command; Fort Detrick MD USA
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98
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Affiliation(s)
- Saheli Chakraborty
- Department of Inorganic and
Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - S. G. Ramkumar
- Department of Inorganic and
Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - S. Ramakrishnan
- Department of Inorganic and
Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
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99
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100
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Mishra S, Ray S, Dalal JJ, Sawhney JPS, Ramakrishnan S, Nair T, Iyengar SS, Bahl VK. Management Protocols of stable coronary artery disease in India: Executive summary. Indian Heart J 2017; 68:868-873. [PMID: 27931562 PMCID: PMC5143826 DOI: 10.1016/j.ihj.2016.11.318] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Sundeep Mishra
- Department of Cardiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
| | | | | | - J P S Sawhney
- Department of Cardiology, Sir Ganga Ram Hospital, New Delhi, India
| | - S Ramakrishnan
- Department of Cardiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | | | - S S Iyengar
- Consultant Cardiologist, Manipal Hospital, Bangalore, India
| | - Vinay K Bahl
- Department of Cardiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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