Recent developments in conducting polymers: applications for electrochemistry

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal. Because of their multifunctional characteristics, e.g., simplistic synthesis, acceptable environmental stability, beneficial optical, electronic, and mechanical features, researchers have largely considered them for diverse applications. Therefore, their capability of catalyzing several electrode reactions has been introduced as one of their significant features. A thin layer of the conducting polymer deposited on the substrate electrode surface can augment the electrode process kinetics of several solution species. Such electrocatalytic procedures with modified conducting polymer electrodes can create beneficial utilization in diverse fields of applied electrochemistry. This review article explores typical recent applications of conductive polymers (2016–2020) as active electrode materials for energy storage applications, electrochemical sensing, and conversion fields such as electrochemical supercapacitors, lithium-ion batteries, fuel cells, and solar cells.

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal.     

Alterações Precoces nas Interleucinas Circulantes e no Risco Inflamatório Residual após Infarto Agudo do Miocárdio

BackgroundPatients with acute myocardial infarction may have a large infarcted area and ventricular dysfunction despite early thrombolysis and revascularization.ObjectiveTo investigate the behavior of circulating cytokines in patients with ST-segment elevation myocardial infarction (STEMI) and their relationship with ventricular function.MethodsIn the BATTLE-AMI (B and T Types of Lymphocytes Evaluation in Acute Myocardial Infarction) trial, patients with STEMI were treated with a pharmacoinvasive strategy. The plasma levels of cytokines (IL-1 β , IL-4, IL-6, IL-10, and IL-18) were tested using enzyme-linked immunosorbent assay (ELISA) at baseline and after 30 days. Infarcted mass and left ventricular ejection fraction (LVEF) were examined by 3-T cardiac magnetic resonance imaging. All p-values < 0.05 were considered statistically significant.ResultsCompared to baseline, lower levels were detected for IL-1 β (p = 0.028) and IL-18 (p < 0.0001) 30 days after STEMI, whereas higher levels were observed for IL-4 (p = 0.001) and IL-10 (p < 0.0001) at that time point. Conversely, no changes were detected for IL-6 levels (p = 0.63). The levels of high-sensitivity C-reactive protein and IL-6 correlated at baseline (rho = 0.45, p < 0.0001) and 30 days after STEMI (rho = 0.29, p = 0.009). At baseline, correlation between IL-6 levels and LVEF was also observed (rho = -0.50, p = 0.004).ConclusionsDuring the first month post-MI, we observed a marked improvement in the balance of pro- and anti-inflammatory cytokines, except for IL-6. These findings suggest residual inflammatory risk. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)     

Diastolic Function Study with Conventional and Pulsed Tissue Doppler Echocardiography Imaging in Acromegalic Patients

Acromegaly is associated with myocardial hypertrophy and it can progress to diastolic and systolic dysfunction. Purpose: To evaluate diastolic function in acromegalic patients through conventional echocardiography (CD) and tissue Doppler imaging (TDI). Methods: Seventeen acromegalic patients were submitted to CD and TDI, and early (E) and atriogenic (A) transmitral flow were evaluated in mitral, septal, and tricuspid regions. Results: In comparison with controls the means of conventional (1.06), septal (1.01), and tricuspid (0.98) E/A ratio were significantly lower in acromegalic patients. E/A ratio <1.0 was demonstrated in 41% and 49% of acromegalics by DC and TDI, respectively, with no statistical difference among the two methods. An inverse linear correlation was shown between mitral E/A ratio and acromegalic age (r =−0.7). Conclusion: In this study, DC and TDI were equally effective in demonstrating diastolic dysfunction, a common finding in acromegalic patients.     

The effect of carvacrol on muscarinic receptors of guinea‐pig tracheal chains

The effects of three concentrations of carvacrol, the constituent of Zataria multiflora Boiss (a monoterpenoid phenol, C₁₀H₁₄O) and 10 nm atropine on muscarinic receptors were tested on: non‐incubated (n = 7), incubated tracheal chains with propranolol and chlorpheniramine (n = 6) and incubated with propranolol (n = 5). The EC₅₀ of all three concentrations of carvacrol in incubated tissues with propranolol and chlorpheniramine was significantly greater than those of incubated tissues with propranolol and non‐incubated trachea (p < 0.05 to p < 0.001). The EC₅₀ of two higher concentrations of carvacrol (0.2 and 0.4 µg/mL) in incubated tissues with propranolol was also significantly greater than those of non‐incubated trachea (p < 0.01 to p < 0.001). The maximum response in the presence of all concentrations of carvacrol in non‐incubated and incubated tissues with propranolol and chlorpheniramine and those of its two higher concentrations (0.2 and 0.4 µg/mL) in incubated tissues with propranolol were lower than saline (p < 0.05 to p < 0.001). There were parallel rightward shifts in the concentration–response curves in the presence of all concentrations of carvacrol in non‐incubated and incubated tissues with propranolol and its lower concentration in incubated tissues with propranolol and chlorpheniramine. These results indicated an inhibitory effect of carvacrol on muscarinic receptors. A β‐adrenoceptor stimulatory effect was also suggested for carvacrol. Copyright © 2010 John Wiley & Sons, Ltd.     

The effects of peripheral deafferentation on spontaneously bursting neurons in the somatosensory cortex of waking cats

Single neurons (n=356) were studied in the forelimb representation of awake, quietly resting cats. Thirty-five spontaneously bursting neurons in a sample of 206 cells recorded before forelimb deafferentation were compared to 39 spontaneously bursting neurons in a sample of 127 neurons studied 1–3 weeks after deafferentation. The probability of encountering bursting neurons increased significantly following deafferentation from 17% to 31% of the sample (P<0.005). The same 5 classes of bursting cells were observed after deafferentation but there were significant changes in the duration of interspike intervals in some classes, in the probability of observing certain classes, and in the proportion of spikes found in bursts. The probability of encountering class III cells, a class thought to consist primarily of non-inactivating pyramidal burst neurons, nearly doubled and the average interspike interval length within the burst increased from 1.9 to 3.0 ms. The burst structure in the other classes did not change but they were found less frequently. These other classes may include inhibitory interneurons which receive less excitatory drive after deafferentation and therefore provide less inhibition to class III cells. The differential behavior of the different classes of bursting cells may be one reason why the overall level of spontaneous activity does not change after deafferentation and it suggests that there are homeostatic mechanisms in primary somatosensory cortex that maintain a certain level of neural activity.