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Khan S, Vasudevan S. Biomedical instrumentation of photoacoustic imaging and quantitative sensing for clinical applications. Rev Sci Instrum 2023; 94:091502. [PMID: 37747328 DOI: 10.1063/5.0151882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 09/02/2023] [Indexed: 09/26/2023]
Abstract
Photoacoustic (PA) imaging has been well researched over the last couple of decades and has found many applications in biomedical engineering. This has evinced interest among many scientists in developing this as a compact instrument for biomedical diagnosis. This review discusses various instrumentation developments for PA experimental setups and their applications in the biomedical diagnostic field. It also covers the PA spectral response or PA sensing technique, which uses the spectral information of the PA signal and performs sensing to deliver a fast, cost-effective, and compact screening tool instead of imaging. Primarily, this review provides an overview of PA imaging concepts and the development of hardware instrumentation systems in both the excitation and acquisition stages of this technique. Later, the paper discusses PA sensing, the quantitative spectral parameter extraction from the PA spectrum, and the correlation study of the spectral parameters with the physical parameters of the tissue. This PA sensing technique was used to diagnose various diseases, such as thyroid nodules, breast cancer, renal disorders, and zoonotic diseases, based on the mechanical and biological characteristics of the tissues. The paper culminates with a discussion section that provides future developments that are necessary to take this technique into clinical applications as a quantitative PA imaging technique.
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Affiliation(s)
- S Khan
- Department of Electrical Engineering, Indian Institute of Technology, Indore 453552, India
| | - S Vasudevan
- Department of Electrical Engineering, Indian Institute of Technology, Indore 453552, India
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Monroy GL, Erfanzadeh M, Tao M, DePaoli DT, Saytashev I, Nam SA, Rafi H, Kwong KC, Shea K, Vakoc BJ, Vasudevan S, Hammer DX. Development of polarization-sensitive optical coherence tomography imaging platform and metrics to quantify electrostimulation-induced peripheral nerve injury in vivo in a small animal model. Neurophotonics 2023; 10:025004. [PMID: 37077218 PMCID: PMC10109528 DOI: 10.1117/1.nph.10.2.025004] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Abstract
Significance Neuromodulation devices are rapidly evolving for the treatment of neurological diseases and conditions. Injury from implantation or long-term use without obvious functional losses is often only detectable through terminal histology. New technologies are needed that assess the peripheral nervous system (PNS) under normal and diseased or injured conditions. Aim We aim to demonstrate an imaging and stimulation platform that can elucidate the biological mechanisms and impacts of neurostimulation in the PNS and apply it to the sciatic nerve to extract imaging metrics indicating electrical overstimulation. Approach A sciatic nerve injury model in a 15-rat cohort was observed using a newly developed imaging and stimulation platform that can detect electrical overstimulation effects with polarization-sensitive optical coherence tomography. The sciatic nerve was electrically stimulated using a custom-developed nerve holder with embedded electrodes for 1 h, followed by a 1-h recovery period, delivered at above-threshold Shannon model k -values in experimental groups: sham control (SC, n = 5 , 0.0 mA / 0 Hz ), stimulation level 1 (SL1, n = 5 , 3.4 mA / 50 Hz , and k = 2.57 ), and stimulation level 2 (SL2, n = 5 , 6.8 mA / 100 Hz , and k = 3.17 ). Results The stimulation and imaging system successfully captured study data across the cohort. When compared to a SC after a 1-week recovery, the fascicle closest to the stimulation lead showed an average change of + 4 % / - 309 % (SL1/SL2) in phase retardation and - 79 % / - 148 % in optical attenuation relative to SC. Analysis of immunohistochemistry (IHC) shows a + 1 % / - 36 % difference in myelin pixel counts and - 13 % / + 29 % difference in axon pixel counts, and an overall increase in cell nuclei pixel count of + 20 % / + 35 % . These metrics were consistent with IHC and hematoxylin/eosin tissue section analysis. Conclusions The poststimulation changes observed in our study are manifestations of nerve injury and repair, specifically degeneration and angiogenesis. Optical imaging metrics quantify these processes and may help evaluate the safety and efficacy of neuromodulation devices.
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Affiliation(s)
- Guillermo L. Monroy
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Mohsen Erfanzadeh
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Michael Tao
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Damon T. DePaoli
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Ilyas Saytashev
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Stephanie A. Nam
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Harmain Rafi
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
| | - Kasey C. Kwong
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Katherine Shea
- U. S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of Clinical Pharmacology, Office of Translational Science, Division of Applied Regulatory Science, Silver Spring, Maryland, United States
| | - Benjamin J. Vakoc
- Massachusetts General Hospital, Harvard Medical School, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
- Massachusetts Institute of Technology, Division of Health Science and Technology, Cambridge, Massachusetts, United States
| | - Srikanth Vasudevan
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
- Address all correspondence to Srikanth Vasudevan, ; Daniel X. Hammer,
| | - Daniel X. Hammer
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Division of Biomedical Physics, Silver Spring, Maryland, United States
- Address all correspondence to Srikanth Vasudevan, ; Daniel X. Hammer,
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Saytashev I, Yoon YC, Vakoc BJ, Vasudevan S, Hammer DX. Improved in vivo optical coherence tomography imaging of animal peripheral nerves using a prism nerve holder. J Biomed Opt 2023; 28:026002. [PMID: 36785561 PMCID: PMC9921515 DOI: 10.1117/1.jbo.28.2.026002] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/20/2023] [Indexed: 06/01/2023]
Abstract
Significance Modern optical volumetric imaging modalities, such as optical coherence tomography (OCT), provide enormous information about the structure, function, and physiology of living tissue. Although optical imaging achieves lateral resolution on the order of the wavelength of light used, and OCT achieves axial resolution on a similar micron scale, tissue optical properties, particularly high scattering and absorption, limit light penetration to only a few millimeters. In addition, in vivo imaging modalities are susceptible to significant motion artifacts due to cardiac and respiratory function. These effects limit access to artifact-free optical measurements during peripheral neurosurgery to only a portion of the exposed nerve without further modification to the procedure. Aim We aim to improve in vivo OCT imaging during peripheral neurosurgery in small and large animals by increasing the amount of visualized nerve volume as well as suppressing motion of the imaged area. Approach We designed a nerve holder with embedded mirror prisms for peripheral nerve volumetric imaging as well as a specific beam steering strategy to acquire prism and direct view volumes in one session with minimal motion artifacts. Results The axially imaged volumes from mirror prisms increased the OCT signal intensity by > 22 dB over a 1.25-mm imaging depth in tissue-mimicking phantoms. We then demonstrated the new imaging capabilities in visualizing peripheral nerves from direct and side views in living rats and minipigs using a polarization-sensitive OCT system. Prism views have shown nerve fascicles and vasculature from the bottom half of the imaged nerve which was not visible in direct view. Conclusions We demonstrated improved OCT imaging during neurosurgery in small and large animals by combining the use of a prism nerve holder with a specifically designed beam scanning protocol. Our strategy can be applied to existing OCT imaging systems with minimal hardware modification, increasing the nerve tissue volume visualized. Enhanced imaging depth techniques may lead to a greater adoption of structural and functional optical biomarkers in preclinical and clinical medicine.
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Affiliation(s)
- Ilyas Saytashev
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Silver Spring, Maryland, United States
| | - Yong-Chul Yoon
- Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
| | - Benjamin J. Vakoc
- Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
| | - Srikanth Vasudevan
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Silver Spring, Maryland, United States
| | - Daniel X. Hammer
- U. S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Silver Spring, Maryland, United States
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Kamath KA, Vasudevan S, Pandey H. Duplicated inferior vena cava in live-related renal transplant donor nephrectomy. Indian J Transplant 2023. [DOI: 10.4103/ijot.ijot_51_22] [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: 04/03/2023] Open
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Arulmoorthy MP, Vijayan R, Sinduja K, Suresh E, Vasudevan S. Infection with Decapod iridescent virus 1: an emerging disease in shrimp culture. Arch Microbiol 2022; 204:685. [DOI: 10.1007/s00203-022-03289-8] [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] [Received: 05/20/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022]
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Vasudevan S, Kabilan HK, Jagadish K, Anantheswar YN, Chandrappa AB, Sreekumar D, Marwah A. The Role of Dermal Regeneration Template in Anterior Abdominal Wall Defect after Burst Abdomen: A Case Report in Acute Graft Versus Host Disease of the Gastrointestinal Tract in Aplastic Anemia. J Indian Assoc Pediatr Surg 2022; 27:760-763. [PMID: 36714496 PMCID: PMC9878513 DOI: 10.4103/jiaps.jiaps_20_22] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/08/2022] [Accepted: 08/27/2022] [Indexed: 11/12/2022] Open
Abstract
Acute graft-versus-host disease of the gastrointestinal tract (GI-aGVHD) is a rare condition, often requiring multiple laparotomies, ultimately leading to a burst abdomen. We report the successful use of a dermal regeneration template (DRT), combined with negative pressure wound therapy (NPWT) and skin grafts, to reconstruct the abdominal skin in an 11-year-old boy. The patient was a case of aplastic anemia, who underwent bone marrow transfers, the first of which failed and the second one was successful. He eventually developed gastrointestinal GVHD. Repeated laparotomies were done for recurrent intestinal obstruction. He also underwent resection anastomosis and end ileostomy, after which he developed an anterior abdominal wall defect due to a burst abdomen. After 12 months of management with multiple dressings, NPWT, and DRT, a stable coverage was achieved, without skin retraction. We report our experience in anterior abdominal wall reconstruction in a case of GI-aGVHD using DRT.
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Affiliation(s)
- Srikanth Vasudevan
- Department of Plastic Surgery, Manipal Hospitals, Bengaluru, Karnataka, India
| | | | - Krithika Jagadish
- Department of Plastic Surgery, Manipal Hospitals, Bengaluru, Karnataka, India
| | - Y N Anantheswar
- Department of Plastic Surgery, Manipal Hospitals, Bengaluru, Karnataka, India
| | | | - Dinkar Sreekumar
- Department of Plastic Surgery, Manipal Hospitals, Bengaluru, Karnataka, India
| | - Annika Marwah
- Department of Plastic Surgery, Manipal Hospitals, Bengaluru, Karnataka, India
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Vasudevan S, Saha A, Tarver ME, Patel B. Digital biomarkers: Convergence of digital health technologies and biomarkers. NPJ Digit Med 2022; 5:36. [PMID: 35338234 PMCID: PMC8956713 DOI: 10.1038/s41746-022-00583-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/24/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Srikanth Vasudevan
- Division of All Hazards Response, Science, and Strategic Partnerships, Office of Strategic Partnerships and Technology Innovation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Anindita Saha
- Digital Health Center of Excellence, Office of Strategic Partnerships and Technology Innovation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Michelle E Tarver
- Office of Strategic Partnerships and Technology Innovation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Bakul Patel
- Digital Health Center of Excellence, Office of Strategic Partnerships and Technology Innovation, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, USA.
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Vasudevan S, Vaidya S, S RB, C AB, N AY, Nagireddy SR. Temporary Extrathoracic Vacuum Therapy Splint in Chest Wall Reconstruction. Indian J Plast Surg 2021; 54:211-214. [PMID: 34239247 PMCID: PMC8257296 DOI: 10.1055/s-0041-1729502] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background
Paradoxical respiration is a sinister consequence of bony chest cage defects which can persist even post chest wall reconstruction. It leads to prolonged dependence on mechanical ventilation postoperatively, thereby delaying recovery.
Methods
Negative pressure wound therapy (NPWT) was applied in early postoperative period to a patient with chest wall defect reconstructed with folded prolene mesh and free anterolateral thigh flap. Arterial blood gas (ABG), fraction of inspired oxygen (FiO
2
), peak end expiratory pressure (PEEP), oxygen saturation (SpO
2
), and blood pressure (BP) readings pre and post NPWT application were compared.
Results
There was marked improvement in the breathing mechanics and related parameters post NPWT application over the flap.
Conclusions
Negative extrathoracic pressure in the form of a temporary splint can enable early weaning off the ventilator and a smoother postoperative recovery in reconstructed chest wall defects.
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Affiliation(s)
- Srikanth Vasudevan
- Department of Plastic and Reconstructive Surgery, Manipal Hospital, Bangalore, India
| | - Shriram Vaidya
- Department of Critical Care Medicine, Manipal Hospital, Bangalore, India
| | - Ritu Baath S
- Department of Plastic and Reconstructive Surgery, Manipal Hospital, Bangalore, India
| | - Ashok Basur C
- Department of Plastic and Reconstructive Surgery, Manipal Hospital, Bangalore, India
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Vasudevan S, Flashner-Abramson E, Alkhatib H, Roy Chowdhury S, Adejumobi IA, Vilenski D, Stefansky S, Rubinstein AM, Kravchenko-Balasha N. Overcoming resistance to BRAF V600E inhibition in melanoma by deciphering and targeting personalized protein network alterations. NPJ Precis Oncol 2021; 5:50. [PMID: 34112933 PMCID: PMC8192524 DOI: 10.1038/s41698-021-00190-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 05/13/2021] [Indexed: 12/11/2022] Open
Abstract
BRAFV600E melanoma patients, despite initially responding to the clinically prescribed anti-BRAFV600E therapy, often relapse, and their tumors develop drug resistance. While it is widely accepted that these tumors are originally driven by the BRAFV600E mutation, they often eventually diverge and become supported by various signaling networks. Therefore, patient-specific altered signaling signatures should be deciphered and treated individually. In this study, we design individualized melanoma combination treatments based on personalized network alterations. Using an information-theoretic approach, we compute high-resolution patient-specific altered signaling signatures. These altered signaling signatures each consist of several co-expressed subnetworks, which should all be targeted to optimally inhibit the entire altered signaling flux. Based on these data, we design smart, personalized drug combinations, often consisting of FDA-approved drugs. We validate our approach in vitro and in vivo showing that individualized drug combinations that are rationally based on patient-specific altered signaling signatures are more efficient than the clinically used anti-BRAFV600E or BRAFV600E/MEK targeted therapy. Furthermore, these drug combinations are highly selective, as a drug combination efficient for one BRAFV600E tumor is significantly less efficient for another, and vice versa. The approach presented herein can be broadly applicable to aid clinicians to rationally design patient-specific anti-melanoma drug combinations.
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Affiliation(s)
- S Vasudevan
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - E Flashner-Abramson
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Heba Alkhatib
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sangita Roy Chowdhury
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - I A Adejumobi
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - D Vilenski
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - S Stefansky
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - A M Rubinstein
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - N Kravchenko-Balasha
- The Institute of Biomedical and Oral Research, Hebrew University of Jerusalem, Jerusalem, Israel.
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Ring T, Witte C, Vasudevan S, Das S, Ranecky ST, Lee H, Ladda N, Senftleben A, Braun H, Baumert T. Self-referencing circular dichroism ion yield measurements for improved statistics using femtosecond laser pulses. Rev Sci Instrum 2021; 92:033001. [PMID: 33820110 DOI: 10.1063/5.0036344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak. The method presented in this contribution reduces the measurement error significantly. A common path optical setup generates a pair of counter-rotating laser foci in the interaction region of a time-of-flight spectrometer. As the space focus condition is fulfilled for both foci individually, this becomes a twin-peak ion source with well separated and sufficiently resolved mass peaks. The individual control of polarization allows for in situ correction of experimental fluctuations measuring circular dichroism. Our robust optical setup produces reliable and reproducible results and is applicable for dispersion sensitive femtosecond laser pulses. In this contribution, we use 3-methyl-cyclopentanone as a prototype molecule to illustrate the evaluation procedure and the measurement principle.
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Affiliation(s)
- T Ring
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - C Witte
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - S Vasudevan
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - S Das
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - S T Ranecky
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - H Lee
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - N Ladda
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - A Senftleben
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - H Braun
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - T Baumert
- Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
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Abstract
Background
Indocyanine green (ICG) lymphangiography is being increasingly employed to assess the severity of lymphedema, locate the areas of patent linear lymphatics and dermal backflow and plan treatment. This study suggests a novel method of reporting ICG findings in extremities to enable easy understanding among surgeons and physiotherapists and avoid repeat testing when a patient visits a disparate lymphedema center or clinician.
Methods
A reporting protocol was developed in the lymphedema clinic of the plastic surgery department, and patients were asked to bring along the report in every subsequent review. The ICG findings were recorded on the fluorescence imaging system as well. The report was prepared by one and analyzed by two different clinicians without repeating the test on 10 consecutive patients.
Results
The interrater reliability of findings in the report was found to be 98.7% among the three clinicians.
Conclusion
The reporting system was found to be illustratable and reproducible
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Affiliation(s)
| | - Ritu Batth
- Department of Plastic and Reconstructive Surgery, Manipal Hospital, Bangalore, India
| | - Srikanth Vasudevan
- Department of Plastic and Reconstructive Surgery, Manipal Hospital, Bangalore, India
| | | | - Dinkar Sreekumar
- Department of Plastic and Reconstructive Surgery, Manipal Hospital, Bangalore, India
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Yaghouby F, Jang K, Hoang U, Asgari S, Vasudevan S. Sex Differences in Vagus Nerve Stimulation Effects on Rat Cardiovascular and Immune Systems. Front Neurosci 2020; 14:560668. [PMID: 33240036 PMCID: PMC7677457 DOI: 10.3389/fnins.2020.560668] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 05/09/2020] [Accepted: 09/22/2020] [Indexed: 01/09/2023] Open
Abstract
Background Investigations into the benefits of vagus nerve stimulation (VNS) through pre-clinical and clinical research have led to promising findings for treating several disorders. Despite proven effectiveness of VNS on conditions such as epilepsy and depression, understanding of off-target effects and contributing factors such as sex differences can be beneficial to optimize therapy design. New Methods In this article, we assessed longitudinal effects of VNS on cardiovascular and immune systems, and studied potential sex differences using a rat model of long-term VNS. Rats were implanted with cuff electrodes around the left cervical vagus nerve for VNS, and wireless physiological monitoring devices for continuous monitoring of cardiovascular system using electrocardiogram (ECG) signals. ECG morphology and heart rate variability (HRV) features were extracted to assess cardiovascular changes resulting from VNS in short-term and long-term timescales. We also assessed VNS effects on expression of inflammatory cytokines in blood during the course of the experiment. Statistical analysis was performed to compare results between Treatment and Sham groups, and between male and female animals from Treatment and Sham groups. Results Considerable differences between male and female rats in cardiovascular effects of VNS were observed in multiple cardiovascular features. However, the effects seemed to be transient with approximately 1-h recovery after VNS. While short-term cardiovascular effects were mainly observed in male rats, females in general showed more significant long-term effects even after VNS stopped. We did not observe notable changes or sex differences in systemic cytokine levels resulting from VNS. Comparison With Existing Methods Compared to existing methods, our study design incorporated wireless physiological monitoring and systemic blood cytokine level analysis, along with long-term VNS experiments in unanesthetized rats to study sex differences. Conclusion The contribution of sex differences for long-term VNS off-target effects on cardiovascular and immune systems was assessed using awake behaving rats. Although VNS did not change the concentration of inflammatory biomarkers in systemic circulation for male and female rats, we observed significant differences in cardiovascular effects of VNS characterized using ECG morphology and HRV analyses.
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Affiliation(s)
- Farid Yaghouby
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Kee Jang
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Uyen Hoang
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Sepideh Asgari
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Srikanth Vasudevan
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
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Groff J, Vasudevan S, Yaghouby F. Vagus Nerve Stimulation Unequally Disturbs Circadian Variation of Cardiac Rhythms in Male and Female Rats. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2020:3384-3387. [PMID: 33018730 DOI: 10.1109/embc44109.2020.9176140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vagus nerve stimulation (VNS) is a neurostimulation therapy for epilepsy and severe depression and has been recently shown to be effective for other conditions. Despite its demonstrated safety and efficacy, long-term and off-target effects of VNS remain to be fully determined. One of the complications reported in epilepsy is stimulation-induced sleep abnormalities. As epilepsy itself can impact sleep quality, contribution of VNS alone in such off-target effects remain mainly unknown. In this study, we analyzed data from long-term VNS experiments in rats to characterize effects of VNS on circadian rhythms derived from heart rate and heart rate variability (HRV). We have also explored possible sex differences in long-term effects of VNS on intrinsic biological rhythms. Compared with control animals, significant VNS-induced changes in circadian rhythms were observed particularly in female rats over 24h and 6h light cycles (1PM-7PM). These findings enhance our understanding of VNS contribution and biological sex role on sleep difficulties reported by using VNS therapy.
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Rao AYN, Reddy SN, Chandrappa AB, Vasudevan S, Batth R. A Study of Aesthetic and Functional Outcome Following Structural Fat Grafting for Facial Scars and Contour Deformity. Craniomaxillofac Trauma Reconstr 2020; 13:305-312. [PMID: 33456702 DOI: 10.1177/1943387520948709] [Citation(s) in RCA: 1] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Study Design This is a prospective observational study of 60 consecutive cases with facial scars and contour deformity who underwent structural fat grafting. Objectives The aim of the present article is to highlight how fat grafting helps to improve aesthetic and functional outcome in facial scars and contour deformities. It also highlights the factors that need to be considered while planning autologous fat grafting to get better aesthetic results. Methods This is a prospective observational study of 60 consecutive cases with facial scars and contour deformity. The study was conducted from May 2014 to April 2019 in a tertiary care hospital. All the patients were followed up for a minimum period of 1 year from the date of surgery. Assessment of post-operative aesthetic outcome, in terms of satisfaction, was done using the Visual Analogue Scale (VAS), which ranges from 1 to 10 by the patient and operative surgeon. Results The mean age was 30.8 9.8 years. Out of 60 patients, 20 patients underwent additional procedure like dermabrasion and collagen dressing to improve aesthetic outcome. Among 60 patients, 24 patients had transient edema and 10 patients had bruising at the recipient site. There were no major donor site complications except pain which was managed conservatively. Mean patient satisfaction score is 7 and mean surgeon satisfaction score is 7.25. Conclusion Despite the ongoing concerns about survival and longevity of fat grafts and also unpredictability of long-term outcomes, fat grafting has become a very useful surgical tool to improve the quality of facial scars and correct contour deformity. Our series shows excellent outcome both clinically as well as from the patient satisfaction. Future research is warranted in the fields of the adipocyte derived stem cells and to expand the clinical application of fat grafting.
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Affiliation(s)
- Anantheswar Y N Rao
- Plastic, Micro & Craniofacial Surgery, Manipal Education and Medical Group International India Pvt Ltd, Bangalore, Karnataka, India
| | - Sudarshan Nagireddy Reddy
- Plastic, Micro & Craniofacial Surgery, Manipal Education and Medical Group International India Pvt Ltd, Bangalore, Karnataka, India
| | - Ashok Basroor Chandrappa
- Plastic, Micro & Craniofacial Surgery, Manipal Education and Medical Group International India Pvt Ltd, Bangalore, Karnataka, India
| | - Srikanth Vasudevan
- Plastic, Micro & Craniofacial Surgery, Manipal Education and Medical Group International India Pvt Ltd, Bangalore, Karnataka, India
| | - Rittu Batth
- Plastic, Micro & Craniofacial Surgery, Manipal Education and Medical Group International India Pvt Ltd, Bangalore, Karnataka, India
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15
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Izmailova ES, Wagner JA, Ammour N, Amondikar N, Bell‐Vlasov A, Berman S, Bloomfield D, Brady LS, Cai X, Calle RA, Campbell M, Cerreta F, Clay I, Foschini L, Furlong P, Goldel R, Goldsack JS, Groenen PM, Folarin A, Heemskerk J, Honig P, Hotopf M, Kamphaus T, Karlin DR, Leptak C, Liu Q, Manji H, Mather RJ, Menetski JP, Narayan VA, Papadopoulos E, Patel B, Patrick‐Lake B, Podichetty JT, Pratap A, Servais L, Stephenson D, Tenaerts P, Tromberg BJ, Usdin S, Vasudevan S, Zipunnikov V, Hoffmann SC. Remote Digital Monitoring for Medical Product Development. Clin Transl Sci 2020. [PMCID: PMC7877824 DOI: 10.1111/cts.12851] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The use of digital health products has gained considerable interest as a new way to improve therapeutic research and development. Although these products are being adopted by various industries and stakeholders, their incorporation in clinical trials has been slow due to a disconnect between the promises of digital products and potential risks in using these new technologies in the absence of regulatory support. The Foundation for the National Institutes of Health (FNIH) Biomarkers Consortium hosted a public workshop to address challenges and opportunities in this field. Important characteristics of tool development were addressed in a series of presentations, case studies, and open panel sessions. The workshop participants endorsed the usefulness of an evidentiary criteria framework, highlighted the importance of early patient engagement, and emphasized the potential impact of digital monitoring tools and precompetitive collaborations. Concerns were expressed about the lack of real‐life validation examples and the limitations of legacy standards used as a benchmark for novel tool development and validation. Participants recognized the need for novel analytical and statistical approaches to accommodate analyses of these novel data types. Future directions are to harmonize definitions to build common methodologies and foster multidisciplinary collaborations; to develop approaches toward integrating digital monitoring data with the totality of the data in clinical trials, and to continue an open dialog in the community. There was a consensus that all these efforts combined may create a paradigm shift of how clinical trials are planned, conducted, and results brought to regulatory reviews.
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Affiliation(s)
| | | | - Nadir Ammour
- Sanofi Research & Development Chilly‐Mazarin France
| | - Ninad Amondikar
- The Michael J. Fox Foundation for Parkinson's Research New York New York USA
| | - Andrea Bell‐Vlasov
- Center for Devices and Radiological Health, US Food and Drug Administration Silver Spring Maryland USA
| | - Steven Berman
- Center for Drug Evaluation and Research, US Food and Drug Administration Silver Spring Maryland USA
| | | | - Linda S. Brady
- National Institute of Mental Health National Institutes of Health Bethesda Maryland USA
| | | | | | - Michelle Campbell
- Center for Drug Evaluation and Research, US Food and Drug Administration Silver Spring Maryland USA
| | | | - Ieuan Clay
- Evidation Health San Mateo California USA
| | | | - Pat Furlong
- Parent Project Muscular Dystrophy Hackensack New Jersey USA
| | - Rob Goldel
- Center for Devices and Radiological Health, US Food and Drug Administration Silver Spring Maryland USA
| | | | | | | | - Jill Heemskerk
- National Institute of Biomedical Imaging and Bioengineering National Institutes of Health Bethesda Maryland USA
| | | | | | - Tania Kamphaus
- Foundation for the National Institutes of Health North Bethesda Maryland USA
| | | | - Christopher Leptak
- Center for Drug Evaluation and Research, US Food and Drug Administration Silver Spring Maryland USA
| | - Qi Liu
- Center for Drug Evaluation and Research, US Food and Drug Administration Silver Spring Maryland USA
| | - Husseini Manji
- Janssen Research and Development LLC Titusville New Jersey USA
| | | | - Joseph P. Menetski
- Foundation for the National Institutes of Health North Bethesda Maryland USA
| | | | - Elektra Papadopoulos
- Center for Drug Evaluation and Research, US Food and Drug Administration Silver Spring Maryland USA
| | - Bakul Patel
- Center for Devices and Radiological Health, US Food and Drug Administration Silver Spring Maryland USA
| | | | | | | | - Laurent Servais
- University of Liège Neuromuscular Reference Center Disease Liege Belgium
- MDUK Neuromuscular Center University of Oxford Oxford UK
| | | | - Pam Tenaerts
- Clinical Trials Transformation Initiative Durham North Carolina USA
| | - Bruce J. Tromberg
- National Institute of Biomedical Imaging and Bioengineering National Institutes of Health Bethesda Maryland USA
| | - Steve Usdin
- BioCentury Publications Washington District of Columbia USA
| | - Srikanth Vasudevan
- Center for Devices and Radiological Health, US Food and Drug Administration Silver Spring Maryland USA
| | - Vadim Zipunnikov
- Johns Hopkins Bloomberg School of Public Health Baltimore Maryland USA
| | - Steven C. Hoffmann
- Foundation for the National Institutes of Health North Bethesda Maryland USA
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16
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Balasubramanian AR, Vasudevan S, Shanmugam K, Lévesque CM, Solomon AP, Neelakantan P. Combinatorial effects of trans-cinnamaldehyde with fluoride and chlorhexidine on Streptococcus mutans. J Appl Microbiol 2020; 130:382-393. [PMID: 32707601 DOI: 10.1111/jam.14794] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/06/2020] [Accepted: 07/18/2020] [Indexed: 01/03/2023]
Abstract
AIMS The aim of this study was to investigate the effects of trans-cinnamaldehyde (TC) and its synergistic activity with chlorhexidine (CHX) and fluoride against Streptococcus mutans. METHODS AND RESULTS Streptococcus mutans UA159 was treated with TC alone and in combination with CHX or sodium fluoride. The synergy profile was analysed using the Zero Interaction Potency model. TC showed strong synergism (synergy score of 21·697) with CHX, but additive effect (synergy score of 5·298) with fluoride. TC and the combinations were tested for acid production (glycolytic pH drop) and biofilm formation by S. mutans, and nitric oxide production in macrophages. TC significantly inhibited sucrose-dependent biofilm formation and acid production by S. mutans. Mechanistic studies were carried out by qRT-PCR-based transcriptomic studies which showed that TC acts by impairing genes related to metabolism, quorum sensing, bacteriocin expression, stress tolerance and biofilm formation. CONCLUSIONS trans-Cinnamaldehyde potentiates CHX and sodium fluoride in inhibiting S. mutans biofilms and virulence through multiple mechanisms. This study sheds significant new light on the potential to develop TC as an anti-caries treatment. SIGNIFICANCE AND IMPACT OF THE STUDY Oral diseases were classified as a 'silent epidemic' in the US Surgeon General's Report on Oral Health. Two decades later, >4 billion people are still affected worldwide by caries, having significant effects on the quality of life. There is an urgent need to develop novel compounds and strategies to combat dental caries. Here, we prove that TC downregulates multiple pathways and potentiates the CHX and fluoride to prevent S. mutans biofilms and virulence. This study sheds significant new light on the potential to develop TC in combination with CHX or fluoride as novel treatments to arrest dental caries.
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Affiliation(s)
- A R Balasubramanian
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - S Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - K Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - C M Lévesque
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - A P Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - P Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR
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Tao M, Monroy G, Erfanzadeh M, Rafi H, Vakoc B, Vasudevan S, Hammer D. Characterization of New Optical Imaging Biomarkers of Peripheral Nerve Overstimulation. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.09815] [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: 11/11/2022]
Affiliation(s)
| | | | | | | | - Benjamin Vakoc
- Massachusetts General Hospital
- Harvard Medical School
- Massachusetts Institute of Technology
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18
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Chandrappa AB, Batth RS, Vasudevan S, Yellambalase ANR, Kumar PN, Reddy S, Seles JN. Assessment of Functional Recovery and Subjective Donor-Site Morbidity Following Radial Forearm Flap Reconstruction in Small- to Moderate-Sized Palatal Defects. Craniomaxillofac Trauma Reconstr 2020; 13:71-77. [PMID: 32642035 DOI: 10.1177/1943387520904879] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Context Palatal defects are encountered following tumor extirpation, trauma, or congenitally. Among the known alternatives, radial artery free forearm flap (RAFF) is a versatile flap that confers good results in head and neck reconstruction, but donor-site morbidity has been an issue of discontent among the plastic surgeons. This limitation needs to be studied further and addressed considering the unmatched quality of this tissue. Aims This study aims to weigh the impact of the functional edge of this flap against the unpopular donor-site morbidity on a group of patients. Settings and Design This is a retrospective analysis of recuperation of palatal function and patient concerns with the donor-site function and cosmesis on 7 consecutive patients with small-to-moderate palatal defects reconstructed with RAFF. Methods and Materials Postoperative recovery of speech, palatal movement, and restoration of oromaxillary interface was assessed using objective tests, such as speech intelligibility testing and articulation studies. Simultaneously, subjective donor-site function and cosmesis were assessed using Patient Scar Assessment Scale (PSAS), Upper Extremity Functional Index (UEFI), and donor limb sensory testing. Results and Conclusion Mean PSAS score was 8.28/60, and UEFI score reported was 77/80, which reflect high patient satisfaction with the donor site. Nasoendoscopy shows remarkable restoration of palate anatomy. Intelligibility testing depicts near-normal speech understandability, whereas articulation studies revealed distortions post-palatal reconstruction with RAFF. Radial artery free forearm flap should be considered as the forerunner of reconstruction in palatal defects involving less than 50%.
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Affiliation(s)
- Ashok B Chandrappa
- Department of Plastic and Reconstructive surgery, Manipal Hospital, Bangalore, Karnataka, India
| | - Ritu S Batth
- Department of Plastic and Reconstructive surgery, Manipal Hospital, Bangalore, Karnataka, India
| | - Srikanth Vasudevan
- Department of Plastic and Reconstructive surgery, Manipal Hospital, Bangalore, Karnataka, India
| | | | - Pradeep N Kumar
- Department of Plastic and Reconstructive surgery, Manipal Hospital, Bangalore, Karnataka, India
| | - Sudarshan Reddy
- Department of Plastic and Reconstructive surgery, Manipal Hospital, Bangalore, Karnataka, India
| | - J Nidya Seles
- Department of Speech and Language Pathology, Manipal Hospital, Bangalore, Karnataka, India
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19
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Radhakrishna V, Radhakrishnan CN, Kabilan HK, Chandrappa AB, Vasudevan S. Limb Salvage in an Extensive, Complicated Vascular Lesion of the Arm in an Infant. J Indian Assoc Pediatr Surg 2020; 25:121-125. [PMID: 32139995 PMCID: PMC7020671 DOI: 10.4103/jiaps.jiaps_16_19] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 04/26/2019] [Accepted: 05/25/2019] [Indexed: 11/04/2022] Open
Abstract
When a vascular lesion involving a limb poses a hazard to the life, treatment options are excision or amputation of the limb. Although excision can be hazardous, limb salvage with vascular control is the best treatment option. We report limb salvage in an infant with an extensive infected congenital hemangioma complicated with consumptive coagulopathy.
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Affiliation(s)
- Veerabhadra Radhakrishna
- Department of Paediatric Surgery, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
| | | | | | | | - Srikanth Vasudevan
- Department of Plastic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
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20
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DILEEP K, Yousif Ali Salem H, Khalifa AlHadari A, Mohammad AlQedrah D, sam A, Vasudevan S, Jose D, Varghese S. SAT-239 VASCULAR ACESS OUTCOME-MULTIDISCIPLINARY APPROACH IN THE VASCULAR ACESS CARE CLINIC. Kidney Int Rep 2020. [DOI: 10.1016/j.ekir.2020.02.254] [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: 10/24/2022] Open
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21
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Vo J, Chang TC, Shea KI, Myers M, Arbabian A, Vasudevan S. Assessment of miniaturized ultrasound-powered implants: an in vivo study. J Neural Eng 2020; 17:016072. [DOI: 10.1088/1741-2552/ab6fc2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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22
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Newsome P, Schattenberg J, Serfaty L, Aghemo A, Augustin S, Tsochatzis E, Canbay A, Ledinghen V, Bugianesi E, Romero-Gomez M, Ryder S, Bantel H, Boursier J, Petta S, Crespo J, Castera L, Leroy V, Le Pen C, Fricke F, Elliott R, Atella V, Mestre-Ferrandiz J, Floros L, Torbica A, Morgan A, Hartmanis S, Trylesinki A, Cure S, Stirzaker E, Vasudevan S, Pezzulo L, Ratziu V. The economic cost and health burden of non-alcoholic steatohepatitis in the EU5 countries. Dig Liver Dis 2020. [DOI: 10.1016/j.dld.2019.12.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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23
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Vasudevan S, Nagireddy S, Chandrappa A, Anantheshwar YN, Batth R, Kablian H, Sreekumar D. A prospective study on efficacy of topical bupivacaine in split skin grafting donor site in immediate postoperative pain relief. Indian J Burns 2020. [DOI: 10.4103/ijb.ijb_2_20] [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: 11/04/2022] Open
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24
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Shafer B, Welle C, Vasudevan S. A rat model for assessing the long-term safety and performance of peripheral nerve electrode arrays. J Neurosci Methods 2019; 328:108437. [PMID: 31526764 DOI: 10.1016/j.jneumeth.2019.108437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 08/05/2019] [Accepted: 09/13/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND High-resolution peripheral nerve interfaces (PNIs) can provide amputees with intuitive motor control and sensory feedback. Current PNIs are limited by early device failure and suboptimal long-term stability. The present study aims to incorporate functional assessment into an in vivo test platform to assess the long-term safety and performance of PNIs for recording and stimulation. NEW METHODS Utah electrode arrays (EA) were implanted in the rat sciatic nerve along with electromyography wires in the gastrocnemius and tibialis anterior. Cranial EEG screws were implanted in the somatosensory cortex for 12 weeks. Spontaneous neural activity was recorded using the implanted EA and stimulation-induced activity was monitored throughout the experiment. The impedance of each electrode was measured, and nerve function tests were conducted throughout the EA lifetime. Post-hoc safety assessments included scanning electron microscopy (SEM) of the EA and nerve histomorphometric analysis. RESULTS EA recordings were stable, and stimulation with EA elicited somatosensory evoked potentials and muscle contractions. Motor and sensory function tests indicated minimal deficits. Histomorphometric analysis indicated changes in nerve microstructure. SEM indicated EA-tip fracture, while lead wire breakage primarily caused device failure. COMPARISON WITH EXISTING METHODS We improved our prior platform with the addition of functional assessments of sensory pathways, a robust EMG array design to increase device longevity, and quantitative analysis of nerve microstructure. CONCLUSION We present a test platform for long-term assessment of peripheral nerve interfaces for stimulation and recording. Using this platform, we demonstrate recording and stimulation with minimal impact on nerve function, while EA lead wire breakage and tip fracture could limit long-term device use.
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Affiliation(s)
- Benjamin Shafer
- U. S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, USA
| | - Cristin Welle
- University of Colorado, Anschutz Medical Campus, Departments of Neurosurgery and Bioengineering, Aurora, CO, 80045, USA
| | - Srikanth Vasudevan
- U. S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, USA.
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25
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Ashok BC, Nagaraj PK, Vasudevan S, Rao AYN, Nagireddy SR, Batth RS. Extended adipofascial wrap around radial forearm flap for hard palate reconstruction. Indian J Plast Surg 2019; 51:306-308. [PMID: 30983731 PMCID: PMC6440351 DOI: 10.4103/ijps.ijps_81_18] [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] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background While using radial forearm free flap in palate reconstruction, the pedicle lies in the nasal floor, constantly exposed to the nasal secretions and turbulent air current. To overcome this problem, we have designed a procedure which utilises the adipofascial extension to wrap the pedicle and nasal side of the flap. Materials and Methods The study was done during 2017 and 2018, 2 years' period. Totally 13 consecutive patients with defect in the palate status post-oncological resection and those in whom local flaps were not enough to cover the defect were included into the study. These patients were divided into two groups. First group in whom adipofascial extension was not used to cover the pedicle and second group in whom adipofascial extension was used to cover the pedicle. The incidence of nasal crusting, secondary haemorrage, blow out and flap necrosis were analysed and compared. Results In Group 1, we had 2 among 6 (33%) patients with secondary haemorrage. One patient had partial flap loss. On exploring, we noticed thrombosis of cephalic vein. We did not had any incidence of blow out of the pedicle. In Group 2, none of the patients had any secondary haemorrage. All flaps healed well. On doing nasal endoscopy at 6 months of follow-up, all flaps showed complete mucosalisation at the nasal side. Conclusion Use of adipofascial extension while planning a radial forearm free flap to cover the nasal side of the flap and pedicle in the nasal floor helps to reduce the nasal crusting and secondary haemorrhage.
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Affiliation(s)
- B C Ashok
- Department of Plastic and Cosmetic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
| | - Pradeep Kumar Nagaraj
- Department of Plastic and Cosmetic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
| | - Srikanth Vasudevan
- Department of Plastic and Cosmetic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
| | - Anantheshwar Y N Rao
- Department of Plastic and Cosmetic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
| | | | - Ritu Singh Batth
- Department of Plastic and Cosmetic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
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26
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Chandrappa AB, Nagaraj PK, Vasudevan S, Nagaraj AY, Jagadish K, Shah A. Use of selfie sticks and iPhones to record operative photos and videos in plastic surgery. Indian J Plast Surg 2019; 50:82-84. [PMID: 28615816 PMCID: PMC5469242 DOI: 10.4103/ijps.ijps_26_17] [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] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Use of smartphone has become ubiquitous. With smartphone cameras becoming powerful, they are replacing digital cameras and digital SLRs as primary instruments to take photos and record videos. It is natural even for plastic surgeons that smartphones are handy to take still photographs and even record high-definition or 4K videos. Another invention which has become popular with smartphone photography is a selfie stick. We explain the possibility and methodology of using an iPhone and selfie stick to take operative photographs and high-quality videos.
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Affiliation(s)
| | | | - Srikanth Vasudevan
- Department of Plastic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
| | | | - Krithika Jagadish
- Department of Plastic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
| | - Ankit Shah
- Department of Plastic Surgery, Manipal Hospital, Bengaluru, Karnataka, India
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27
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Abstract
Aim: Investigations into the benefits of vagus nerve stimulation (VNS) using rodents have led to promising findings for treating clinical disorders. However, the majority of research has been limited to acute timelines. We developed a rodent model for longitudinal assessment of VNS and validated it with a long-term experiment incorporating continuous physiological monitoring. While the primary aim was not to investigate the effects of VNS on the cardiovascular system, we analyzed cardiovascular parameters to demonstrate the model's capabilities in a long-term stimulation-and-recording setup. Materials & methods: Rats were implanted with a cuff electrode around the cervical vagus nerve and electrocardiogram monitoring devices were implanted in the peritoneal cavity. We also designed a connector mount for seamless access to the cuff electrode for VNS in awake-behaving rats. Results & conclusion: Results signified easy-to-interface VNS system, electrode robustness and discernible physiological signals in a long-term setup. Analysis of the cardiovascular parameters revealed some transient effects during VNS. Our proposed model enables long-term VNS experiments along with physiological monitoring in unanesthetized rats.
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Affiliation(s)
- Farid Yaghouby
- US Food & Drug Administration, Center for Devices & Radiological Health (CDRH), Office of Science & Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA
| | - Benjamin Shafer
- US Food & Drug Administration, Center for Devices & Radiological Health (CDRH), Office of Science & Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA
| | - Srikanth Vasudevan
- US Food & Drug Administration, Center for Devices & Radiological Health (CDRH), Office of Science & Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA
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28
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Vasudevan S, Vo J, Shafer B, Nam AS, Vakoc BJ, Hammer DX. Toward optical coherence tomography angiography-based biomarkers to assess the safety of peripheral nerve electrostimulation. J Neural Eng 2019; 16:036024. [PMID: 30917357 PMCID: PMC6583899 DOI: 10.1088/1741-2552/ab1405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Peripheral nerves serve as a link between the central nervous system and its targets. Altering peripheral nerve activity through targeted electrical stimulation is being investigated as a therapy for modulating end organ function. To support rapid advancement in the field, novel approaches to predict and prevent nerve injury resulting from electrical stimulation must be developed to overcome the limitations of traditional histological methods. The present study aims to develop an optical imaging-based approach for real-time assessment of peripheral nerve injury associated with electrical stimulation. APPROACH We developed an optical coherence tomography (OCT) angiography system and a 3D printed stimulating nerve stabilizer (sNS) to assess the real-time microvascular and blood flow changes associated with electrical stimulation of peripheral nerves. We then compared the microvascular changes with established nerve function analysis and immunohistochemistry to correlate changes with nerve injury. MAIN RESULTS Electrical stimulation of peripheral nerves has a direct influence on vessel diameter and capillary flow. The stimulation used in this study did not alter motor function significantly, but a delayed onset of mechanical allodynia at lower thresholds was observed using a sensory function test. Immunohistochemical analysis pointed to an increased number of macrophages within nerve fascicles and axon sprouting potentially related to nerve injury. SIGNIFICANCE This study is the first to demonstrate the ability to image peripheral nerve microvasculature changes during electrical stimulation. This expands the knowledge in the field and can be used to develop potential biomarkers to predict nerve injury resulting from electrical stimulation.
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Affiliation(s)
- Srikanth Vasudevan
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States of America
| | - Jesse Vo
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States of America
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States of America
| | - Benjamin Shafer
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States of America
| | - Ahhyun S Nam
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA, United States of America
| | - Benjamin J Vakoc
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA, United States of America
| | - Daniel X Hammer
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States of America
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Shafer B, Yaghouby F, Vasudevan S. Short-Time Fourier Transform Based Spike Detection of Spontaneous Peripheral Nerve Activity. Annu Int Conf IEEE Eng Med Biol Soc 2018; 2018:2418-2421. [PMID: 30440895 DOI: 10.1109/embc.2018.8512803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Peripheral nerve interfaces are designed to record neural activity from residual nerves in amputees. Reliable detection of neural events from these recordings dictate the performance of neuroprosthetic device control. Extraction of neural events from peripheral nerve recordings is challenging because of low signal to noise ratio (SNR), sparse spiking pattern and the presence of electromyographic signal contamination from the surrounding muscles. In this study, we developed a spike detection algorithm based on Short-time Fourier Transform (STFT) and compared its performance to simple thresholding technique using synthesized nerve recordings. To mimic peripheral nerve recordings and produce ground-truth for validation, a quasi-simulation framework is proposed to incrementally synthesize signals from physiological recordings. A detection threshold was optimized on the spectral features of simulated signals and performance evaluation was done using an independent simulated data set. Results show that the STFT based technique, compared to the simple thresholding, reduces the false detection rate even in recordings with moderately low SNR.
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Straka MM, Shafer B, Vasudevan S, Welle C, Rieth L. Characterizing Longitudinal Changes in the Impedance Spectra of In-Vivo Peripheral Nerve Electrodes. Micromachines (Basel) 2018; 9:mi9110587. [PMID: 30424513 PMCID: PMC6266965 DOI: 10.3390/mi9110587] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 12/18/2022]
Abstract
Characterizing the aging processes of electrodes in vivo is essential in order to elucidate the changes of the electrode–tissue interface and the device. However, commonly used impedance measurements at 1 kHz are insufficient for determining electrode viability, with measurements being prone to false positives. We implanted cohorts of five iridium oxide (IrOx) and six platinum (Pt) Utah arrays into the sciatic nerve of rats, and collected the electrochemical impedance spectroscopy (EIS) up to 12 weeks or until array failure. We developed a method to classify the shapes of the magnitude and phase spectra, and correlated the classifications to circuit models and electrochemical processes at the interface likely responsible. We found categories of EIS characteristic of iridium oxide tip metallization, platinum tip metallization, tip metal degradation, encapsulation degradation, and wire breakage in the lead. We also fitted the impedance spectra as features to a fine-Gaussian support vector machine (SVM) algorithm for both IrOx and Pt tipped arrays, with a prediction accuracy for categories of 95% and 99%, respectively. Together, this suggests that these simple and computationally efficient algorithms are sufficient to explain the majority of variance across a wide range of EIS data describing Utah arrays. These categories were assessed over time, providing insights into the degradation and failure mechanisms for both the electrode–tissue interface and wire bundle. Methods developed in this study will allow for a better understanding of how EIS can characterize the physical changes to electrodes in vivo.
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Affiliation(s)
- Malgorzata M Straka
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA.
| | - Benjamin Shafer
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA.
| | - Srikanth Vasudevan
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD 20993, USA.
| | - Cristin Welle
- Departments of Neurosurgery and Bioengineering, University of Colorado, Aurora, CO 80045, USA.
| | - Loren Rieth
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY 11030, USA.
- Departments of Electrical Engineering and Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
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Srikanth V, Pillai D, Vasudevan S. Utility of neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and mean platelet volume as predective and prognostic markers in patients with liver abscess in a tertiary care center in India. Int J Infect Dis 2018. [DOI: 10.1016/j.ijid.2018.04.3551] [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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Kang C, Chang TC, Vo J, Charthad J, Weber M, Arbabian A, Vasudevan S. Long-term in vivo performance of novel ultrasound powered implantable devices. Annu Int Conf IEEE Eng Med Biol Soc 2018; 2018:2985-2988. [PMID: 30441025 DOI: 10.1109/embc.2018.8512978] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Neuromodulation devices have been approved for the treatment of epilepsy and seizures, with many other applications currently under research investigation. These devices rely on implanted battery powered pulse generators, that require replacement over time. Miniaturized ultrasound powered implantable devices have the potential to eliminate the need for batteries in neuromodulation devices. While these devices have been assessed in vitro, long-term in vivo assessment is required to determine device safety and performance. In this study, we developed a multi-stage long-term test platform to assess the performance of miniaturized ultrasound powered implantable devices.
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Anand S, Desai V, Alsmadi N, Kanneganti A, Nguyen DHT, Tran M, Patil L, Vasudevan S, Xu C, Hong Y, Cheng J, Keefer E, Romero-Ortega MI. Asymmetric Sensory-Motor Regeneration of Transected Peripheral Nerves Using Molecular Guidance Cues. Sci Rep 2017; 7:14323. [PMID: 29085079 PMCID: PMC5662603 DOI: 10.1038/s41598-017-14331-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/06/2017] [Indexed: 11/22/2022] Open
Abstract
Neural interfaces are designed to decode motor intent and evoke sensory precepts in amputees. In peripheral nerves, recording movement intent is challenging because motor axons are only a small fraction compared to sensory fibers and are heterogeneously mixed particularly at proximal levels. We previously reported that pain and myelinated axons regenerating through a Y-shaped nerve guide with sealed ends, can be modulated by luminar release of nerve growth factor (NGF) and neurotrophin-3 (NT-3), respectively. Here, we evaluate the differential potency of NGF, glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), pleiotrophin (PTN), and NT-3 in asymmetrically guiding the regeneration of sensory and motor neurons. We report that, in the absence of distal target organs, molecular guidance cues can mediate the growth of electrically conductive fascicles with normal microanatomy. Compared to Y-tube compartments with bovine serum albumin (BSA), GDNF and NGF increased the motor and sensory axon content, respectively. In addition, the sensory to motor ratio was significantly increased by PTN (12.7:1) when compared to a BDNF + GDNF choice. The differential content of motor and sensory axons modulated by selective guidance cues may provide a strategy to better define axon types in peripheral nerve interfaces.
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Affiliation(s)
- Sanjay Anand
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA
| | - Vidhi Desai
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76010, USA
| | - Nesreen Alsmadi
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA
| | - Aswini Kanneganti
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA
| | - Dianna Huyen-Tram Nguyen
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76010, USA
| | - Martin Tran
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76010, USA
| | - Lokesh Patil
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA
| | - Srikanth Vasudevan
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Cancan Xu
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76010, USA
| | - Yi Hong
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76010, USA
| | - Jonathan Cheng
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Edward Keefer
- Nerves Incorporated, P.O. Box 141295, Dallas, TX 75214, USA
| | - Mario I Romero-Ortega
- Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA.
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Abstract
OBJECTIVE In the US alone, there are approximately 185 000 cases of limb amputation annually, which can reduce the quality of life for those individuals. Current prosthesis technology could be improved by access to signals from the nervous system for intuitive prosthesis control. After amputation, residual peripheral nerves continue to convey motor signals and electrical stimulation of these nerves can elicit sensory percepts. However, current technology for extracting information directly from peripheral nerves has limited chronic reliability, and novel approaches must be vetted to ensure safe long-term use. The present study aims to optimize methods to establish a test platform using rodent model to assess the long term safety and performance of electrode interfaces implanted in the peripheral nerves. APPROACH Floating Microelectrode Arrays (FMA, Microprobes for Life Sciences) were implanted into the rodent sciatic nerve. Weekly in vivo recordings and impedance measurements were performed in animals to assess performance and physical integrity of electrodes. Motor (walking track analysis) and sensory (Von Frey) function tests were used to assess change in nerve function due to the implant. Following the terminal recording session, the nerve was explanted and the health of axons, myelin and surrounding tissues were assessed using immunohistochemistry (IHC). The explanted electrodes were visualized under high magnification using scanning electrode microscopy (SEM) to observe any physical damage. MAIN RESULTS Recordings of axonal action potentials demonstrated notable session-to-session variability. Impedance of the electrodes increased upon implantation and displayed relative stability until electrode failure. Initial deficits in motor function recovered by 2 weeks, while sensory deficits persisted through 6 weeks of assessment. The primary cause of failure was identified as lead wire breakage in all of animals. IHC indicated myelinated and unmyelinated axons near the implanted electrode shanks, along with dense cellular accumulations near the implant site. Scanning electron microscopy (SEM) showed alterations of the electrode insulation and deformation of electrode shanks. SIGNIFICANCE We describe a comprehensive testing platform with applicability to electrodes that record from the peripheral nerves. This study assesses the long term safety and performance of electrodes in the peripheral nerves using a rodent model. Under this animal test platform, FMA electrodes record single unit action potentials but have limited chronic reliability due to structural weaknesses. Future work will apply these methods to other commercially-available and novel peripheral electrode technologies.
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Affiliation(s)
- Srikanth Vasudevan
- Division of Biomedical Physics, Office of Science and Engineering Laboratory, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USA
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Desai VH, Anand S, Tran M, Kanneganti A, Vasudevan S, Seifert JL, Cheng J, Keefer EW, Romero-Ortega MI. Chronic sensory-motor activity in behaving animals using regenerative multi-electrode interfaces. Annu Int Conf IEEE Eng Med Biol Soc 2016; 2014:1973-6. [PMID: 25570368 DOI: 10.1109/embc.2014.6944000] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control and feel of robotic prosthetic limbs. We have developed a Regenerative Multi-electrode Interface (REMI) that guides re-growing axons through an electrode array deployed in the lumen of a nerve guide. While acute studies have shown the use of the REMI in the rat sciatic nerve, the quality of chronic signal recording has not been reported. Here we show that implantation of this interface in the sciatic nerve is stable with high quality recordings up to 120 days and failures mainly attributable to abiotic factors related to pedestal detachment and wire breakage. We further tested the interfacing of REMI with fascicles of the sciatic nerve that primarily innervate muscles (tibial) and skin (sural). When implanted into the tibial nerve, bursting activity was observed synchronous to stepping. However, implantation of REMI into the sural nerve failed due to its small size. While fascicles smaller than 300 μm are a challenge for regenerative interfacing, we show that a modified REMI can be used in an insertion mode to record sensory signals from skin. In summary, the REMI represents an effective tool for recording firing patterns of specific axon types during voluntary movement, which may be used to improve the motor control and sensory feedback in closed loop control systems for robotic prosthesis.
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Le Tonqueze O, Kollu S, Lee S, Al-Salah M, Truesdell SS, Vasudevan S. Regulation of monocyte induced cell migration by the RNA binding protein, FXR1. Cell Cycle 2016; 15:1874-82. [PMID: 27229378 DOI: 10.1080/15384101.2016.1189040] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [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: 01/05/2023] Open
Abstract
FXR1 belongs to a family of RNA-binding proteins that play critical roles in post-transcriptional regulation of gene expression in immunity, development and cancer. FXR1 is associated with regulation of specific mRNAs in myocytes and macrophages. In quiescent cells (> 24 h of extended serum-starvation, ∼30-48 h or more), a spliced isoform of FXR1, FXR1a, promotes translation of the cytokine TNFα, independent of the effects of RNA levels. Here we examined the role of FXR1 in THP1 human monocytic leukemic cells that were grown in serum, as well as in early (24 h) serum-starvation conditions that demonstrates differences in gene expression mechanisms and is distinct from quiescent (> 24 h extended serum-starvation) cells. Global RNA profiling, conducted to investigate the role of FXR1 on mRNA levels, revealed that FXR1 affects levels of specific mRNAs in serum-grown and in early 24 h serum-starvation conditions. FXR1 decreases levels of several mRNAs, including as previously identified, CDKN1A (p21CIP1 or p21) mRNA in serum-grown cells. Interestingly, we find that FXR1 positively regulates mRNA levels of specific cytokines and chemokines in serum-grown and in early 24 h serum-starvation conditions. These include IL1β and CCL2 that control cell migration. Accordingly, depletion and overexpression of FXR1 decreased and increased levels of CCL2 mRNA. Consistent with the reduced levels of IL1β, CCL2 and other chemokines upon FXR1 depletion, our data reveal that depletion of FXR1 decreases the ability of these cells to induce cell migration of neighboring monocytic cells. These data reveal a new role of FXR1 in controlling induction of monocyte migration.
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Affiliation(s)
- O Le Tonqueze
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - S Kollu
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - S Lee
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - M Al-Salah
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - S S Truesdell
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - S Vasudevan
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
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Bowsher K, Civillico EF, Coburn J, Collinger J, Contreras-Vidal JL, Denison T, Donoghue J, French J, Getzoff N, Hochberg LR, Hoffmann M, Judy J, Kleitman N, Knaack G, Krauthamer V, Ludwig K, Moynahan M, Pancrazio JJ, Peckham PH, Pena C, Pinto V, Ryan T, Saha D, Scharen H, Shermer S, Skodacek K, Takmakov P, Tyler D, Vasudevan S, Wachrathit K, Weber D, Welle CG, Ye M. Brain–computer interface devices for patients with paralysis and amputation: a meeting report. J Neural Eng 2016; 13:023001. [DOI: 10.1088/1741-2560/13/2/023001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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38
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Santhanasabapathy R, Vasudevan S, Anupriya K, Pabitha R, Sudhandiran G. Farnesol quells oxidative stress, reactive gliosis and inflammation during acrylamide-induced neurotoxicity: Behavioral and biochemical evidence. Neuroscience 2015; 308:212-27. [PMID: 26341906 DOI: 10.1016/j.neuroscience.2015.08.067] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/26/2015] [Accepted: 08/27/2015] [Indexed: 01/05/2023]
Abstract
Acrylamide (ACR) is an industrial pollutant, to which humans are exposed through chemicals associated with day to day human life and contributes to neurological disorders. The role of reactive gliosis upon toxic insults remains paradoxical, and the immunomodulatory events during ACR intoxication remain obscure. In view of this, the present study investigated ACR-induced (20mg/kgb.wt for 4weeks) neurodegeneration in the context of oxidative stress and associated inflammatory events and the ability of farnesol, a sesquiterpene, to mitigate reactive gliosis in the brain of Swiss albino mice. Farnesol supplementation (100mg/kgb.wt.) showed a marked improvement in gait performance, neuromuscular function and fine motor coordination and attenuated ACR-induced diminution in glutathione (GSH) with parallel reduction in lipid peroxidation (LPO), protein carbonyls, hydroxide, hydroperoxide and nitrite levels. Farnesol treatment significantly ameliorated ACR-mediated histological aberrations and reactive gliosis by downregulating Glial fibrillary acidic protein (GFAP) and Ionizsed calcium-binding adapter molecule-1 (Iba-1) in the cortex, hippocampus and striatum. Further, ACR stimulated increase in levels of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and inducible form of nitric oxide synthase (iNOS) were considerably decreased by farnesol. In conclusion, our findings indicate that farnesol exerts neuroprotective efficacy during ACR-induced neuropathology by suppressing reactive gliosis and associated inflammatory events.
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Affiliation(s)
- R Santhanasabapathy
- Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil nadu, India
| | - S Vasudevan
- Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil nadu, India
| | - K Anupriya
- Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil nadu, India
| | - R Pabitha
- Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil nadu, India
| | - G Sudhandiran
- Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil nadu, India.
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Venkatkarthick R, Davidson DJ, Ravichandran S, Vengatesan S, Sozhan G, Vasudevan S. Eco-friendly and facilely prepared silica modified amorphous titania (TiO2–SiO2) electrocatalyst for the O2 and H2 evolution reactions. Catal Sci Technol 2015. [DOI: 10.1039/c5cy00805k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A silica modified amorphous titania (TiO2–SiO2) electrocatalyst was prepared by a simple, cheap, and scalable preparation procedure. The catalyst is active in the oxygen and hydrogen evolution reactions, leading to a promising bifunctional electrocatalyst.
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Affiliation(s)
- R. Venkatkarthick
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - D. J. Davidson
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - S. Ravichandran
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - S. Vengatesan
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - G. Sozhan
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - S. Vasudevan
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006
- India
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40
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Kamaraj R, Davidson DJ, Sozhan G, Vasudevan S. Adsorption of herbicide 2-(2,4-dichlorophenoxy)propanoic acid by electrochemically generated aluminum hydroxides: an alternative to chemical dosing. RSC Adv 2015. [DOI: 10.1039/c5ra03339j] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Flow diagram of pilot plant scale studies for the removal of 2,4-DP.
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Affiliation(s)
- R. Kamaraj
- CSIR-Central Electrochemical Research Institute
- Karaikudi-630 006
- India
| | - D. J. Davidson
- CSIR-Central Electrochemical Research Institute
- Karaikudi-630 006
- India
| | - G. Sozhan
- CSIR-Central Electrochemical Research Institute
- Karaikudi-630 006
- India
| | - S. Vasudevan
- CSIR-Central Electrochemical Research Institute
- Karaikudi-630 006
- India
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Jayamurthy M, Vasudevan S. Temperature Programmed Surface Reaction Studies of the Methanol to Gasoline (MTG) Conversion over ZSM-5. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/bbpc.199500118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ware T, Simon D, Liu C, Musa T, Vasudevan S, Sloan A, Keefer EW, Rennaker RL, Voit W. Thiol-ene/acrylate substrates for softening intracortical electrodes. J Biomed Mater Res B Appl Biomater 2013; 102:1-11. [DOI: 10.1002/jbmb.32946] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 02/20/2013] [Accepted: 03/06/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Taylor Ware
- The University of Texas at Dallas; Department of Materials Science and Engineering; Richardson Texas
| | - Dustin Simon
- The University of Texas at Dallas; Department of Materials Science and Engineering; Richardson Texas
| | - Clive Liu
- The University of Texas at Dallas; Department of Mechanical Engineering; Richardson Texas
| | | | - Srikanth Vasudevan
- The University of Texas at Arlington; Department of Bioengineering; Arlington Texas
| | - Andrew Sloan
- The University of Texas at Dallas, School of Behavioral and Brain Sciences; Richardson Texas
| | | | - Robert L. Rennaker
- The University of Texas at Dallas, School of Behavioral and Brain Sciences; Richardson Texas
| | - Walter Voit
- The University of Texas at Dallas; Department of Materials Science and Engineering; Richardson Texas
- The University of Texas at Dallas; Department of Mechanical Engineering; Richardson Texas
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Venkatkarthick R, Elamathi S, Sangeetha D, Balaji R, Suresh Kannan B, Vasudevan S, Jonas Davidson D, Sozhan G, Ravichandran S. Studies on polymer modified metal oxide anode for oxygen evolution reaction in saline water. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2013.02.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Comer D, Singh P, Vasudevan S. Effective border gateway protocol protection that does not require universal adoption of a public key infrastructure. IET Networks 2012. [DOI: 10.1049/iet-net.2012.0145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
MicroRNAs are small, non-coding RNA regulators of gene expression with important outcomes in cell state, proliferation, metabolism, immunity and development; their deregulation leads to significant clinical consequences. MicroRNAs and their associated target RNAs can be identified by genetic, bioinformatic and biochemical methods. MicroRNAs can recognize target mRNAs via direct base-pairing and recruit effector complexes to modulate their gene expression in a sequence-specific manner. MicroRNA interactions with target RNAs produce their roles in gene expression. The following are some of the validation methods employed to confirm functionally relevant microRNA interactions with their target mRNAs. Each method involves interference with the microRNA or the target mRNA to disable their interaction, which should lead to loss of microRNA-mediated gene expression if the interaction is functionally consequential. Subsequent alleviation of the interference and restoration of productive base-pairing interactions between the microRNA and target should rescue microRNA-mediated gene expression and confirm the functional requirement for direct microRNA-target mRNA interaction. Characterization of functional microRNA interactions with their target mRNAs will provide significant insights into their gene expression regulatory mechanism and lead to the development of potential therapeutic approaches to manipulate these interactions and their consequent gene expression outcomes.
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Affiliation(s)
- S Vasudevan
- Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, United States.
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Vasudevan S, Lakshmi J. Effect of alternating and direct current in an electrocoagulation process on the removal of cadmium from water. Water Sci Technol 2012; 65:353-360. [PMID: 22233915 DOI: 10.2166/wst.2012.859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The main objective of this study was to investigate the effects of AC and DC on the removal of cadmium from water using iron as anode and cathode. The various operating parameters on the removal efficiency of cadmium were investigated. The results showed that the optimum removal efficiency of 98.1 and 97.3% with the energy consumption of 0.734 and 1.413 kWh/kL was achieved at a current density of 0.2 A/dm(2), at pH of 7.0 using AC and DC respectively. The adsorption process follows second order kinetics and the temperature studies showed that adsorption was endothermic and spontaneous in nature.
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Affiliation(s)
- S Vasudevan
- Central Electrochemical Research Institute, Karaikudi, India.
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Seetharaman S, Sozhan G, Ravichandran S, Vasudevan S, Davidson J. Sulfonated Poly (Ether Ether Ketone)-Based Composite Proton-Exchange Membrane for Energy Production. INT J POLYM MATER PO 2011. [DOI: 10.1080/00914037.2010.551359] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Caroline ML, Prakash M, Geetha D, Vasudevan S. Growth, structural, vibrational, optical, laser and dielectric aspects of L-alanine alaninium nitrate single crystal. Spectrochim Acta A Mol Biomol Spectrosc 2011; 79:1936-1940. [PMID: 21700493 DOI: 10.1016/j.saa.2011.05.094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/22/2011] [Accepted: 05/25/2011] [Indexed: 05/31/2023]
Abstract
Bulk single crystals of l-alanine alaninium nitrate [abbreviated as LAAN], an intriguing material for frequency conversion has been grown from its aqueous solution by both slow solvent evaporation and by slow cooling techniques. The optimized pH value to grow good quality LAAN single crystal was found to be 2.5. The grown crystals were subjected to single crystal X-ray diffraction studies to determine the unit cell dimensions and morphology. Vibrational frequencies of the grown crystals by Fourier transform infrared spectroscopic technique were investigated. Also, the presence of hydrogen and carbon atoms in the grown sample was confirmed using proton and carbon NMR analyses. The dielectric constant and dielectric loss measurements of the as grown crystal at different temperatures and frequencies of the applied field are measured and reported. LAAN has good optical transmission in the entire visible region with cutoff wavelength within the UV region confirms its suitability for device fabrications. The existence of second harmonic generation signals was observed using Nd:YAG laser with fundamental wavelength of 1064 nm. Its Laser Damage Threshold (LDT) was measured and also tested by using a Q-switched Nd:YAG laser and the value of LDT of LAAN is 17.76GW/cm2 respectively, is found to be better than certain organic and semiorganic materials.
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Affiliation(s)
- M Lydia Caroline
- Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604407, Tamil Nadu, India.
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Vasudevan S. CS6.3 The status of antiviral development for dengue. Int J Infect Dis 2011. [DOI: 10.1016/s1201-9712(11)60022-2] [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: 10/17/2022] Open
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