Implantable Thin-film Porous Microelectrode Array (P-MEA) for Electrical Stimulation of Engineered Cardiac Tissues

Hiren V. Trada,Venkat Vendra,Joseph P. Tinney,Fangping Yuan,Douglas J. Jackson,Kevin M. Walsh,Bradley B. Keller 한국바이오칩학회 2015 BioChip Journal Vol.9 No.2

We have designed, fabricated, and validated a novel porous, multielectrode array (P-MEA) device capable of low-voltage electrical stimulation of engineered cardiac tissues (ECTs). The primary advantage of this device is the ability to successfully function at a very low voltage thus minimizing any undesirable oxidative by-products in the culture environment or cell injury. Major features of our P-MEA include dimensions of 10 mm width and 82 mm length, four arms to allow movement of the individual pads within ECTs, each embedded electrode arm incorporates eight 100 μm×200 μm rectangular pores surrounding a 950 μm×340 μm exposed electrode, large pads on either side of the porous embedded device to function as current return electrodes, suture holes to aid in vivo suturing and stabilization, and an eight electrode connector pads. Average thickness of the Ni/Au electrodes was 20 nm of nickel and 400 nm of old, an average electrode film thickness of 0.4 μm, and a double polyimide layer thickness of 16 μm. Electrode resistance ranged from 69.45 Ω to 78.52 Ω. Electrochemical impedance spectroscopy confirmed that the P-MEA operates in the 0.01 V to 1.0 V range with favorable charge transfer characteristics. Proof of principle experiments confirmed the ability of the P-MEA to effectively embed within ECT and electricallystimulate ECT during chronic, in vitro culture. Histology imaging shows that the embedding of the device has no adverse effects on the ECT and the cardiomyocytes are aligned within the tissue. Experiments are ongoing to evaluate the role of electrical stimulation on the maturation and function of ECTs. We have designed, fabricated, and validated a novel porous, multielectrode array (P-MEA) device capable of low-voltage electrical stimulation of engineered cardiac tissues (ECTs). The primary advantage of this device is the ability to successfully function at a very low voltage thus minimizing any undesirable oxidative by-products in the culture environment or cell injury. Major features of our P-MEA include dimensions of 10 mm width and 82 mm length, four arms to allow movement of the individual pads within ECTs, each embedded electrode arm incorporates eight 100 μm×200 μm rectangular pores surrounding a 950 μm×340 μm exposed electrode, large pads on either side of the porous embedded device to function as current return electrodes, suture holes to aid in vivo suturing and stabilization, and an eight electrode connector pads. Average thickness of the Ni/Au electrodes was 20 nm of nickel and 400 nm of gold, an average electrode film thickness of 0.4 μm, and a double polyimide layer thickness of 16 μm. Electrode resistance ranged from 69.45 Ω to 78.52 Ω. Electrochemical impedance spectroscopy confirmed that the P-MEA operates in the 0.01 V to 1.0 V range with favorable charge transfer characteristics. Proof of principle experiments confirmed the ability of the P-MEA to effectively embed within ECT and electrically stimulate ECT during chronic, in vitro culture. Histology imaging shows that the embedding of the device has no adverse effects on the ECT and the cardiomyocytes are aligned within the tissue. Experiments are ongoing to evaluate the role of electrical stimulation on the maturation and function of ECTs.

Separate and Joint Associations of Shift Work and Sleep Quality with Lipids

Charles, Luenda E.,Gu, Ja K.,Tinney-Zara, Cathy A.,Fekedulegn, Desta,Ma, Claudia C.,Baughman, Penelope,Hartley, Tara A.,Andrew, Michael E.,Violanti, John M.,Burchfiel, Cecil M. Occupational Safety and Health Research Institute 2016 Safety and health at work Vol.7 No.2

Background: Shift work and/or sleep quality may affect health. We investigated whether shift work and sleep quality, separately and jointly, were associated with abnormal levels of triglycerides, total cholesterol (TC), and low-and high-density lipoprotein cholesterol in 360 police officers (27.5% women). Methods: Triglycerides, TC, and high-density lipoprotein were analyzed on the Abbott Architect; low-density lipoprotein was calculated. Shift work was assessed using City of Buffalo payroll work history records. Sleep quality (good, ${\leq}5$; intermediate, 6-8; poor, ${\geq}9$) was assessed using the Pittsburgh Sleep Quality Index questionnaire. A shift work + sleep quality variable was created: day plus good sleep; day plus poor sleep; afternoon/night plus good; and poor sleep quality. Mean values of lipid biomarkers were compared across categories of the exposures using analysis of variance/analysis of covariance. Results: Shift work was not significantly associated with lipids. However, as sleep quality worsened, mean levels of triglycerides and TC gradually increased but only among female officers (age- and race-adjusted p = 0.013 and 0.030, respectively). Age significantly modified the association between sleep quality and TC. Among officers ${\geq}40$ years old, those reporting poor sleep quality had a significantly higher mean level of TC ($202.9{\pm}3.7mg/dL$) compared with those reporting good sleep quality ($190.6{\pm}4.0mg/dL$) (gender- and race-adjusted p = 0.010). Female officers who worked the day shift and also reported good sleep quality had the lowest mean level of TC compared with women in the other three categories (p = 0.014). Conclusion: Sleep quality and its combined influence with shift work may play a role in the alteration of some lipid measures.

Separate and Joint Associations of Shift Work and Sleep Quality with Lipids

Luenda E Charles,Ja K. Gu,Cathy A. Tinney-Zara,Desta Fekedulegn,Claudia C. Ma,Penelope Baughman,Tara A. Hartley,Michael E. Andrew,John M. Violanti,Cecil M. Burchfiel 한국산업안전보건공단 산업안전보건연구원 2016 Safety and health at work Vol.7 No.2

Background: Shift work and/or sleep quality may affect health. We investigated whether shift work and sleep quality, separately and jointly, were associated with abnormal levels of triglycerides, total cholesterol (TC), and low-and high-density lipoprotein cholesterol in 360 police officers (27.5% women). Methods: Triglycerides, TC, and high-density lipoprotein were analyzed on the Abbott Architect; lowdensity lipoprotein was calculated. Shift work was assessed using City of Buffalo payroll work history records. Sleep quality (good, < 5; intermediate, 6e8; poor, > 9) was assessed using the Pittsburgh Sleep Quality Index questionnaire. A shift work þ sleep quality variable was created: day plus good sleep; day plus poor sleep; afternoon/night plus good; and poor sleep quality. Mean values of lipid biomarkers were compared across categories of the exposures using analysis of variance/analysis of covariance. Results: Shift work was not significantly associated with lipids. However, as sleep quality worsened, mean levels of triglycerides and TC gradually increased but only among female officers (age- and raceadjusted p = 0.013 and 0.030, respectively). Age significantly modified the association between sleep quality and TC. Among officers > 40 years old, those reporting poor sleep quality had a significantly higher mean level of TC (202.9 ± 3.7 mg/dL) compared with those reporting good sleep quality (190.6 ± 4.0 mg/dL) (gender- and race-adjusted p = 0.010). Female officers who worked the day shift and also reported good sleep quality had the lowest mean level of TC compared with women in the other three categories (p = 0.014). Conclusion: Sleep quality and its combined influence with shift work may play a role in the alteration of some lipid measures.

A detailed dynamical investigation of the proposed QS Virginis planetary system

Horner, J.,Wittenmyer, R. A.,Hinse, T. C.,Marshall, J. P.,Mustill, A. J.,Tinney, C. G. Oxford University Press 2013 Monthly notices of the Royal Astronomical Society Vol.435 No.3

Influence of Work Characteristics on the Association Between Police Stress and Sleep Quality

Claudia C. Ma,Tara A. Hartley,Khachatur Sarkisian,Desta Fekedulegn,Anna Mnatsakanova,Sherry Owens,Ja Kook Gu,Cathy Tinney-Zara,John M. Violanti,Michael E. Andrew 한국산업안전보건공단 산업안전보건연구원 2019 Safety and health at work Vol.10 No.1

Background: Police officers’ stress perception, frequency of stressful events (stressors), and police work characteristics may contribute to poor sleep quality through different mechanisms. Methods: We investigated associations of stress severity (measured by stress rating score) and frequency of stressors with sleep quality and examined the influence of police work characteristics including workload, police rank, prior military experience, and shift work on the associations. Participants were 356 police officers (256 men and 100 women) enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress Study from 2004 to 2009. A mean stress rating score and mean frequency of stressors occurring in the past month were computed for each participant from the Spielberger Police Stress Survey data. Sleep quality was assessed using the global score derived from the Pittsburgh Sleep Quality Index survey. Linear associations of the stress rating score and frequency of stressors with sleep quality (Pittsburgh Sleep Quality Index global score) were tested. Age, sex, race/ethnicity, and smoking status were selected as potential confounders. Results: The stress rating score was positively and independently associated with poor sleep quality (b ¼ 0.17, p ¼ 0.002). Only workload significantly modified this association (b ¼ 0.23, p ¼ 0.001 for high workload group; p-interaction ¼ 0.109). The frequency of stressors was positively and independently associated with poor sleep quality (b ¼ 0.13, p ¼ 0.025). Only police rank significantly modified the association (b ¼ 0.007, p ¼ 0.004 for detectives/other executives; p-interaction ¼ 0.076). Conclusion: Both police officers’ perception of stress severity and the frequency of stressors are associated with poor sleep quality. Stress coping or sleep promotion regimens may be more beneficial among police officers reporting high workloads.

Influence of Work Characteristics on the Association Between Police Stress and Sleep Quality

Ma, Claudia C.,Hartley, Tara A.,Sarkisian, Khachatur,Fekedulegn, Desta,Mnatsakanova, Anna,Owens, Sherry,Gu, Ja Kook,Tinney-Zara, Cathy,Violanti, John M.,Andrew, Michael E. Occupational Safety and Health Research Institute 2019 Safety and health at work Vol.10 No.1

Background: Police officers' stress perception, frequency of stressful events (stressors), and police work characteristics may contribute to poor sleep quality through different mechanisms. Methods: We investigated associations of stress severity (measured by stress rating score) and frequency of stressors with sleep quality and examined the influence of police work characteristics including workload, police rank, prior military experience, and shift work on the associations. Participants were 356 police officers (256 men and 100 women) enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress Study from 2004 to 2009. A mean stress rating score and mean frequency of stressors occurring in the past month were computed for each participant from the Spielberger Police Stress Survey data. Sleep quality was assessed using the global score derived from the Pittsburgh Sleep Quality Index survey. Linear associations of the stress rating score and frequency of stressors with sleep quality (Pittsburgh Sleep Quality Index global score) were tested. Age, sex, race/ethnicity, and smoking status were selected as potential confounders. Results: The stress rating score was positively and independently associated with poor sleep quality (${\beta}=0.17$, p = 0.002). Only workload significantly modified this association (${\beta}=0.23$, p = 0.001 for high workload group; p-interaction = 0.109). The frequency of stressors was positively and independently associated with poor sleep quality (${\beta}=0.13$, p = 0.025). Only police rank significantly modified the association (${\beta}=0.007$, p = 0.004 for detectives/other executives; p-interaction = 0.076). Conclusion: Both police officers' perception of stress severity and the frequency of stressors are associated with poor sleep quality. Stress coping or sleep promotion regimens may be more beneficial among police officers reporting high workloads.