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Kim D, Kim W, Kim J, Lee HK, Joo J, Kim B, Allen MG, Lu D, Venkatesh V, Huang Y, Yu KJ, Park YJ, Kim MK, Han S, Won SM. Optimal bilayer composites for temperature-tracking wireless electronics. NANOSCALE 2024. [PMID: 38412042 DOI: 10.1039/d3nr05784d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Modern silicone-based epidermal electronics engineered for body temperature sensing represent a pivotal development in the quest for advancing preventive medicine and enhancing post-surgical monitoring. While these compact and highly flexible electronics empower real-time monitoring in dynamic environments, a noteworthy limitation is the challenge in regulating the infiltration or obstruction of heat from the external environment into the surface layers of these electronics. The study presents a cost-effective temperature sensing solution by embedding wireless electronics in a multi-layered elastomeric composite to meet the dual needs of enhanced thermal insulation for encapsulation in contact with air and improved thermal conductivity for the substrate in contact with the skin. The encapsulating composite benefits from the inclusion of hollow silica microspheres, which reduce the thermal conductivity by 40%, while non-spherical aluminum nitride enhances the thermal conductivity of the substrate by 370%. The addition of particles to the respective composites inevitably leads to an increase in modulus. Two composite elements are engineered to coexist while maintaining a matching low modulus of 3.4 MPa and a stretchability exceeding 30%, all without compromising the optimized thermal properties. Consecutive thermal, electrical, and mechanical characterization confirms the sensor's capacity for precise body temperature monitoring during a single day's lifespan, while also assessing the influence of behavioral factors on body temperature.
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Affiliation(s)
- Doyoung Kim
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
| | - Wooseok Kim
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
| | - Jihwan Kim
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
| | - Hee Kyu Lee
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
| | - Janghoon Joo
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
| | - Bogeun Kim
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
| | - Mark G Allen
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dengyang Lu
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Vishal Venkatesh
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yanghang Huang
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ki Jun Yu
- Functional Bio-integrated Electronics and Energy Management Lab, School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Young-Jin Park
- KERI (Korea Electrotechnology Research Institute), 111, Hanggaul-ro, Sangrok-gu, Ansan, 15588, Republic of Korea
| | - Mu Kyung Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea
| | - Seungyong Han
- Multiscale Bioinspired Technology Lab, Department of Mechanical Engineering, Ajou University, 206, World cup-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16499 Republic of Korea
| | - Sang Min Won
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Korea.
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Sajjadi E, Seven YB, Ehrbar JG, Wymer JP, Mitchell GS, Smith BK. Acute intermittent hypoxia and respiratory muscle recruitment in people with amyotrophic lateral sclerosis: A preliminary study. Exp Neurol 2022; 347:113890. [PMID: 34624328 PMCID: PMC9488543 DOI: 10.1016/j.expneurol.2021.113890] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/28/2021] [Accepted: 10/03/2021] [Indexed: 01/03/2023]
Abstract
Respiratory failure is the main cause of death in amyotrophic lateral sclerosis (ALS). Since no effective treatments to preserve independent breathing are available, there is a critical need for new therapies to preserve or restore breathing ability. Since acute intermittent hypoxia (AIH) elicits spinal respiratory motor plasticity in rodent ALS models, and may restore breathing ability in people with ALS, we performed a proof-of-principle study to investigate this possibility in ALS patients. Quiet breathing, sniff nasal inspiratory pressure (SNIP) and maximal inspiratory pressure (MIP) were tested in 13 persons with ALS and 10 age-matched controls, before and 60 min post-AIH (15, 1 min episodes of 10% O2, 2 min normoxic intervals) or sham AIH (continuous normoxia). The root mean square (RMS) of the right and left diaphragm, 2nd parasternal, scalene and sternocleidomastoid muscles were monitored. A vector analysis was used to calculate summated vector magnitude (Mag) and similarity index (SI) of collective EMG activity during quiet breathing, SNIP and MIP maneuvers. AIH facilitated tidal volume and minute ventilation (treatment main effects: p < 0.05), and Mag (ie. collective respiratory muscle activity; p < 0.001) during quiet breathing in ALS and control subjects, but there was no effect on SI during quiet breathing. SNIP SI decreased in both groups post-AIH (p < 0.005), whereas Mag was unchanged (p = 0.09). No differences were observed in SNIP or MIP post AIH in either group. Discomfort was not reported during AIH by any subject, nor were adverse events observed. Thus, AIH may be a safe way to increase collective inspiratory muscle activity during quiet breathing in ALS patients, although a single AIH presentation was not sufficient to significantly increase peak inspiratory pressure generation. These preliminary results provide evidence that AIH may improve breathing function in people with ALS, and that future studies of prolonged, repetitive AIH protocols are warranted.
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Affiliation(s)
- Elaheh Sajjadi
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA, 32610,McKnight Brain Institute, University of Florida, Gainesville, FL, USA, 32610,Department of Physical Therapy, University of Florida, Gainesville, FL, USA, 32610
| | - Yasin B. Seven
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA, 32610,McKnight Brain Institute, University of Florida, Gainesville, FL, USA, 32610,Department of Physical Therapy, University of Florida, Gainesville, FL, USA, 32610
| | - Jessica G Ehrbar
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA, 32610
| | - James P. Wymer
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA, 32610,McKnight Brain Institute, University of Florida, Gainesville, FL, USA, 32610,Neurology, University of Florida, Gainesville, FL, USA, 32610
| | - Gordon S. Mitchell
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA, 32610,McKnight Brain Institute, University of Florida, Gainesville, FL, USA, 32610,Department of Physical Therapy, University of Florida, Gainesville, FL, USA, 32610
| | - Barbara K. Smith
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA, 32610,Department of Physical Therapy, University of Florida, Gainesville, FL, USA, 32610,Pediatrics, University of Florida, Gainesville, FL, USA, 32610
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Effects of Casein Hydrolysate Ingestion on Thermoregulatory Responses in Healthy Adults during Exercise in Heated Conditions: A Randomized Crossover Trial. Nutrients 2020; 12:nu12030867. [PMID: 32213899 PMCID: PMC7146450 DOI: 10.3390/nu12030867] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/19/2020] [Accepted: 03/22/2020] [Indexed: 11/17/2022] Open
Abstract
Food ingestion has been shown to affect thermoregulation during exercise, while the impact of protein degradant consumption remains unclear. We investigated the effects of casein hydrolysate ingestion on thermoregulatory responses during exercise in the heat. In a randomized, placebo-controlled, double-blind, crossover trial, five men and five women consumed either 5 g of casein hydrolysate or placebo. Thirty minutes after ingestion, participants cycled at 60% VO2max until voluntary exhaustion wearing a hot-water (43 °C) circulation suit. Exercise time to exhaustion, body core temperature, forearm sweat rate, and forearm cutaneous vascular conductance did not differ different between the conditions. However, chest sweat rate and mean skin temperature increased upon casein hydrolysate ingestion compared with placebo during exercise. Increased chest sweat rate upon casein hydrolysate ingestion was associated with elevated sudomotor sensitivity to increasing body core temperature, but not the temperature threshold for initiating sweating. A positive correlation was found between chest sweat rate and plasma total amino acid concentration during exercise. These results suggest that casein hydrolysate ingestion enhances sweating heterogeneously by increasing peripheral sensitivity of the chest's sweating mechanism and elevating skin temperature during exercise in the heat. However, the physiological link between plasma amino acid concentration and sweat rate remains unclear.
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Hayashi K, Suekuni M, Sugiyama K. Effect of food intake on respiratory chemosensitivity to CO2 in young adults. J Physiol Anthropol 2019; 38:8. [PMID: 31287028 PMCID: PMC6615250 DOI: 10.1186/s40101-019-0200-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/01/2019] [Indexed: 11/13/2022] Open
Abstract
Background Food intake augments CO2 production; however, minute ventilation is not augmented during exercise after food intake. Respiratory chemoreceptors respond to CO2 and influence respiration. We examined the effect of food intake on respiratory chemosensitivity to CO2 in young adults. Methods The hypercapnic ventilatory response was measured in eleven healthy individuals before and after food intake. To evaluate the respiratory chemoreflex response to CO2, minute ventilation was plotted against end-tidal PCO2 using data obtained with the rebreathing method. Results Sublingual temperature, CO2 output, minute ventilation, and end-tidal PCO2 were all significantly higher at baseline in the session after food intake than in the session before food intake. On the other hand, there was no significant difference in chemosensitivity to CO2 between the sessions before and after food intake (1.60 ± 0.62 vs. 1.53 ± 0.62 l min−1 mmHg−1). Conclusions Food intake does not influence respiratory chemosensitivity to CO2 in young adults, which is different from infants. This suggests that control of respiration differs between young adults and infants and that the elevated minute ventilation after food intake in young adults is not caused by a change in respiratory chemosensitivity.
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