A report on a survey among Portuguese Association of Interventional Cardiology associates regarding ionizing radiation protection practices in national interventional cath-labs.

INTRODUCTION AND OBJECTIVES: Concerns surrounding the consequences of ionizing radiation (IR) have increased in interventional cardiology (IC). Despite this, the ever-growing complexity of diseases as well as procedures can lead to greater exposure to radiation. The aim of this survey, led by Portuguese Association of Interventional Cardiology (APIC), was to evaluate the level of awareness and current practices on IR protection among its members. METHODS: An online survey was emailed to all APIC members, between August and November 2021. The questionnaire consisted of 50 questions focusing on knowledge and measures of IR protection in the catheterization laboratory. Results were analyzed using descriptive statistics. RESULTS: From a response rate of 46.9%, the study obtained a total sample of 159 responses (156 selected for analysis). Most survey respondents (66.0%) were unaware of the radiation exposure category, and only 60.4% reported systematically using a dosimeter. A large majority (90.4%) employed techniques to minimize exposure to radiation. All participants used personal protective equipment, despite eyewear protection only being used frequently by 49.2% of main operators. Ceiling suspended shields and table protectors were often used. Only two-thirds were familiar with the legally established limit on radiation doses for workers or the dose that should trigger patient follow-up. Most of the survey respondents had a non-certified training in IR procedures and only 32.0% had attended their yearly occupational health consultation. CONCLUSIONS: Safety methods and protective equipment are largely adopted among interventional cardiologists, who have shown some IR awareness. Despite this, there is room for improvement, especially concerning the use of eyewear protection, monitoring, and certification.

Stent for life initiative in Portugal: Progress through years and Covid-19 impact.

BACKGROUND: During Stent for Life Initiative in Portugal lifetime, positive changes in ST elevation myocardial infarction treatment were observed, by the increase of Primary Angioplasty numbers and improvements in patients' behaviour towards myocardial infarction, with an increase in those who called 112 and the lower proportion attending non primary percutaneous coronary intervention centres. Despite public awareness campaigns and system educational programmes, patient and system delay did not change significantly over this period. The aim of this study was to address the public awareness campaign effectiveness on peoples' behaviour facing STEMI, and how Covid-19 has affected STEMI treatment. METHODS: Data from 1381 STEMI patients were collected during a one-month period each year, from 2011 to 2016, and during one and a half month, matching first lockdown in Portugal 2020. Four groups were constituted: Group A (2011); Group B (2012&2013); Group C (2015&2016) and group D (2020). RESULTS: The proportion of patients who called 112, increased significantly (35.2% Group A; 38.7% Group B; 44.0% Group C and 49.6% Group D, p = 0.005); significant reduction was observed in the proportion of patients who attended healthcare centres without PPCI (54.5% group A; 47.6% Group B; 43.2% Group C and 40.9% Group D, p = 0.016), but there were no differences on groups comparison. Total ischemic time, measured from symptoms onset to reperfusion increased progressively from group A [250.0 (178.0-430.0)] to D [296.0 (201.0-457.5.8)] p = 0.012, with statistically significant difference between group C and D (p = 0.034). CONCLUSIONS: During the term of SFL initiative in Portugal, patients resorted less to primary health centres and called more to 112. These results can be attributed the public awareness campaign. Nevertheless, patient and system delays did not significantly change over this period, mainly in late years of SFL, probably for low efficacy of campaigns and in 2020 due to Covid-19 pandemic.

Understanding Transient Ionic Diode Currents and Impedance Responses for Aquivion-Coated Microholes.

Ionic diode based devices or circuits can be applied, for example, in electroosmotic pumps or in desalination processes. Aquivion ionomer coated asymmetrically over a Teflon film (5 µm thickness) with a laser-drilled microhole (approximately 10 µm diameter) gives a cationic diode with a rectification ratio of typically 10-20 (measured in 0.01 M NaCl with ±0.3 V applied bias). Steady state voltammetry, chronoamperometry, and electrochemical impedance spectroscopy data are employed to characterize the ionic diode performance parameters. Next, a COMSOL 6.0 finite element model is employed to quantitatively assess/compare transient phenomena and to extract mechanistic information by comparison with experimental data. The experimental diode time constant and diode switching process associated with a distorted semicircle (with a typical diode switching frequency of 10 Hz) in the Nyquist plot are reproduced by computer simulation and rationalized in terms of microhole diffusion-migration times. Fundamental understanding and modeling of the ionic diode switching process can be exploited in the rational/optimized design of new improved devices.

Prevalence and predictors of chronic thromboembolic pulmonary hypertension following severe forms of acute pulmonary embolism.

INTRODUCTION AND OBJECTIVES: The true prevalence of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) in the Portuguese population remains unknown. We aimed to assess the prevalence and predictors of CTEPH two years after a symptomatic high- (HR) or intermediate-high risk (IHR) PE. METHODS: We conducted a retrospective cohort study of patients admitted with PE between 2014 and 2019 to a Portuguese referral center for pulmonary hypertension. RESULTS: In this single-center registry of 969 patients admitted with PE (annual incidence of 46/100000 population), 194 had HR (5.4%) and IHR (14.7%) PE. After excluding patients who died or had no follow-up in the first three months, 129 patients were included in the analysis. The overall prevalence of suspected CTEPH by clinical assessment, Doppler echocardiography and V/Q lung scan was 6.2% (eight patients). CTEPH was confirmed by right heart catheterization in four of these (3.1%). Increased pulmonary artery systolic pressure (PASP) at admission (OR 1.12; 95% CI 1.04-1.22; p=0.005) and the presence of varicose veins in the lower limbs (OR 7.47; 95% CI 1.53-36.41; p=0.013) were predictors of CTEPH. PASP >60 mmHg at admission identified patients with CTEPH at follow-up with sensitivity and specificity of 83.3% and 76.3%, respectively. All patients diagnosed with CTEPH had at least two radiological findings suggestive of CTEPH at the index event. CONCLUSIONS: In our cohort, the prevalence of CTEPH in survivors of severe forms of acute PE was 6.2%. PASP above 60 mmHg and supporting radiological findings on the index computed tomography scan are highly suggestive of acute-on-chronic CTEPH.

Caenorhabditis elegans as a Prediction Platform for Nanotechnology-Based Strategies: Insights on Analytical Challenges.

Nanotechnology-based strategies have played a pivotal role in innovative products in different technological fields, including medicine, agriculture, and engineering. The redesign of the nanometric scale has improved drug targeting and delivery, diagnosis, water treatment, and analytical methods. Although efficiency brings benefits, toxicity in organisms and the environment is a concern, particularly in light of global climate change and plastic disposal in the environment. Therefore, to measure such effects, alternative models enable the assessment of impacts on both functional properties and toxicity. Caenorhabditis elegans is a nematode model that poses valuable advantages such as transparency, sensibility in responding to exogenous compounds, fast response to perturbations besides the possibility to replicate human disease through transgenics. Herein, we discuss the applications of C. elegans to nanomaterial safety and efficacy evaluations from one health perspective. We also highlight the directions for developing appropriate techniques to safely adopt magnetic and organic nanoparticles, and carbon nanosystems. A description was given of the specifics of targeting and treatment, especially for health purposes. Finally, we discuss C. elegans potential for studying the impacts caused by nanopesticides and nanoplastics as emerging contaminants, pointing out gaps in environmental studies related to toxicity, analytical methods, and future directions.

Evaluation of a graphitic porous carbon modified with iron oxides for atrazine environmental remediation in water by adsorption.

In the last decades, the growth of world agricultural activity has significantly contributed to the increased presence of emerging pollutants such as atrazine (ATZ) in aquatic ecosystems. Due to its high stability to the natural or artificial degradation processes, the ATZ environmental remediation by adsorption has been investigated. In this study, a graphitic-porous-carbon- (GPC) based material with magnetic domains was applied to remove ATZ from aqueous solution. ATZ high adsorption efficiency in a reduced time was achieved in the presence of the GPC adsorbent, leading to a detailed investigation of the mechanisms involved in the adsorption processes. Pseudo-first-order (PFO), pseudo-second-order (PSO), Ritchie, Elovich, and Weber-Morris models were applied to calculate the kinetic process efficiency. Likewise, adsorption isotherms based on Langmuir, Freundlich, Temkin, and Redlich-Peterson models were applied for a detailed understanding of the adsorption mechanisms. GPC was successfully applied for ATZ remediation in natural waters, confirming its high potential for treating natural waters contaminated by ATZ using adsorption process. The material can also be recovered and reused for up to 4 application cycles due to its magnetic properties, showing that in addition to ATZ adsorption efficiency, its sustainable use can be achieved.

Continuous Aspiration Mechanical Thrombectomy for the management of intermediate- and high-risk pulmonary embolism: Data from the first cohort in Portugal.

INTRODUCTION: This study describes the experience of a reference center using continuous aspiration mechanical thrombectomy for acute high- and intermediate-high-risk pulmonary embolism (PE). METHODS: Twenty-nine consecutive patients with acute central PE (48.3% high-risk PE; 82.8% in class >III from the original Pulmonary Embolism Severity Index score; median Charlson Comorbidity Index of 4) were treated with the Indigo® Mechanical Thrombectomy System between March 2018 and March 2020. Technical success was defined as successful placement of the device and initiation of aspiration thrombectomy. Clinical success was defined as any improvement in hemodynamic and/or oxygenation parameters, pulmonary hypertension or right heart strain at 48 hours, and survival to hospital discharge. Safety was defined as freedom from severe adverse events potentially related to the procedure. Three-month follow-up results were collected. RESULTS: Technical success was 96.6%. Miller index and systolic pulmonary arterial pressure were significantly reduced after the procedure (-5.5±3.0, and -10.2±11.5 mmHg, respectively, both p<0.001). There was a significant improvement in mean paO2/FiO2 ratio (+77.1±103.2; p=0.001), shock index (-0.4±0.4; p<0.001), need for aminergic support at 48 h after the procedure (-75.0%, p=0.006) and improvement in right ventricular function in 66.6% (p=0.008). Clinical success was 75.9%. Severe adverse event rate was 10.3%: two deaths during the procedure and one pulmonary macroembolization during device progression. In-hospital and three-month survival rates were 82.8% and 72.4%, respectively. CONCLUSIONS: Aspiration thrombectomy for acute high- and intermediate-high-risk PE is feasible with a high technical and clinical success rate. Nevertheless, all-cause mortality is still high, probably related to the baseline high-risk features of the studied population and associated comorbidities.

Polarization-sensitive optoionic membranes from chiral plasmonic nanoparticles.

Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for their direct photocurrent observation. Chiral metasurfaces increase the electronic sensitivity to circular polarization, but their out-of-plane architecture entails manufacturing and performance trade-offs. Here, we show that nanoporous thin films of chiral nanoparticles enable high sensitivity to circular polarization due to light-induced polarization-dependent ion accumulation at nanoparticle interfaces. Self-assembled multilayers of gold nanoparticles modified with L-phenylalanine generate a photocurrent under right-handed circularly polarized light as high as 2.41 times higher than under left-handed circularly polarized light. The strong plasmonic coupling between the multiple nanoparticles producing planar chiroplasmonic modes facilitates the ejection of electrons, whose entrapment at the membrane-electrolyte interface is promoted by a thick layer of enantiopure phenylalanine. Demonstrated detection of light ellipticity with equal sensitivity at all incident angles mimics phenomenological aspects of polarization vision in marine animals. The simplicity of self-assembly and sensitivity of polarization detection found in optoionic membranes opens the door to a family of miniaturized fluidic devices for chiral photonics.

UV-Vis spectrophotometry coupled to chemometric analysis for the performance evaluation of atrazine photolysis and photocatalysis.

In this study, a spectrophotometric-chemometric (Spec-Chem) approach was applied as an alternative to chromatography to monitor ATZ and by-products after photolytic and photocatalytic oxidation aiming to unveil the ATZ degradation mechanism. Spec-Chem is an accessible, easy-to-operate, low-cost analytical approach to monitor atrazine (ATZ) and by-products, and its applicability was validated by HPLC, the reference technique for the evaluation of pollutant degradation mechanisms. The chromatographic (DChro) and spectrophotometric (DSpec) data found 95% and 57% ATZ removal after 30 min, respectively, proving that the DSpec erroneously induces a 38% loss in removal efficiency. When DSpec was treated by multivariate curve resolution (MCR) analysis for providing chemometric data (DChem), it found ATZ removal and hydroxyatrazine (HAT) formation statistically equal to DChro (t-test, p = 0.05). After unraveling the ATZ degradation mechanism using Spec-Chem, a new hypothesis for the kinetic calculation of ATZ degradation was presented, where the concentrations of ATZ and HAT were used to find k and R2 values representative for the ATZ degradation mechanism. The values found for k were compatible with the literature under similar conditions of ATZ degradation, and the linear correlation coefficients (R2 = 0.99) showed an optimal fit for the proposed hypothesis. Thus, Spec-Chem was successfully applied to unravel the mechanism of photocatalytic degradation of ATZ in the presence of TiO2, while k was obtained by the new hypothesis proposed that considered ATZ and HAT concentration as parameters of kinetic interest. Therefore, the importance of monitoring quantitatively ATZ and HAT were provided in this study, providing new information for the scientific community.

N-compounds speciation analysis in environmental samples using ultrasound-assisted solid-liquid extraction and non-chromatographic techniques.

A fast, efficient, and non-chromatographic method was presented in this study for nitrite, nitrate, and p-nitrophenol (N-compounds) extraction and speciation analysis of environmental samples. By applying ultrasound-assisted solid-liquid extraction (USLE), analytes were efficiently extracted from water, soil, or sediment collected in areas of environmental disaster. These analytes were selectively converted to NO(g) through UV photolysis (NO3-), H2O2/UV photocatalysis (PNP), and direct conversion (NO2-). Following conversion, NO(g) was separated from the liquid phase and determined by high-resolution continuum source molecular absorption spectrometry (HR-CS MAS). The LODs obtained were 0.097 ± 0.004 mg L-1 for nitrite, 0.119 ± 0.004 mg L-1 for nitrate, and 0.090 ± 0.006 mg L-1 for p-nitrophenol. On applying this speciation method to environmental samples, concentrations were found to be up to 0.99 ± 0.03 mg L-1 (NO2-), 49.80 ± 2.5 mg L-1 (NO3-), and 0.10 ± 0.02 mg L-1 (PNP). Finally, addition/recovery study of real water, soil, and sediment samples showed 101 ± 2% recovery for NO2-, 100 ± 1% for NO3-, and 96 ± 5% for PNP.

Five years of Stent for Life in Portugal.

OBJECTIVE: To analyze changes in performance indicators five years after Portugal joined the Stent for Life (SFL) initiative. METHODS: National surveys were carried out annually over one-month periods designated as study Time Points between 2011 (Time Zero) and 2016 (Time Five). In this study, 1340 consecutive patients with suspected ST-elevation myocardial infarction (STEMI) who underwent coronary angiography, admitted to 18 24/7 primary percutaneous coronary intervention (PCI) centers, were enrolled. RESULTS: There was a significant reduction in the proportion of patients who attended primary healthcare centers (20.3% vs. 4.8%, p<0.001) and non-PCI-capable centers (54.5% vs. 42.5%, p=0.013). The proportions of patients who called 112, the national emergency medical services (EMS) number (35.2% vs. 46.6%, p=0.022) and of those transported via the EMS to a PCI-capable center (13.1% vs. 30.5%, p<0.001) increased. The main improvement observed in timings for revascularization was a trend toward a reduction in patient delay (114 min in 2011 vs. 100 min in 2016, p=0.050). System delay and door-to-balloon time remained constant, at a median of 134 and 57 min in 2016, respectively. CONCLUSION: During the lifetime of the SFL initiative in Portugal, there was a positive change in patient delay indicators, especially the lower proportion of patients who attended non-PCI centers, along with an increase in those who called 112. System delay did not change significantly over this period. These results should be taken into consideration in the current Stent - Save a Life initiative.

Numerical Resolving of Net Faradaic Current in Fast-Scan Cyclic Voltammetry Considering Induced Charging Currents.

In this paper, we study theoretically and experimentally the effect of induced charging currents on the fast-scan cyclic voltammetry. As explained in this paper, the phenomenon originates from the coupling between faradaic and capacitive currents in the presence of uncompensated resistance. Due to the existence of induced charging currents, the capacitive contribution to the total current is different from the capacitive current measured in the absence of electroactive species. In this paper, we show that this effect is particularly important when the ratio of the capacitive current and the total current is close to unity, even for a relatively low cell time constant. Consequently, the conventional background subtraction method may be inaccurate in these situations. In this work, we develop a method that separates the faradaic and capacitive currents, combining simulation and experimental data. The method is applicable even in the presence of potential-dependent capacitance. The theoretical results are compared with some previously reported results and with experiments carried out on the potassium ferrocyanide/ferricyanide redox couple. Platinum disk electrodes of different diameters and NaClO4 support electrolyte of different concentrations were used to obtain different cell time constants. The proposed method allowed us to separate the real capacitive current even in the situations where the conventional background subtraction used in many published papers is clearly inappropriate.

Systematic investment in the delivery of guideline-coherent therapy reduces mortality and overall costs in patients with ST-elevation myocardial infarction: Results from the Stent for Life economic model for Romania, Portugal, Basque Country and Kemerovo region.

AIMS: The Stent for Life initiative aims at the reduction of mortality in patients with ST-elevation myocardial infarction by enhancing timely access to primary percutaneous coronary intervention. To assess the associated health and socioeconomic impact, the Stent for Life economic project was launched and applied to four model regions: Romania, Portugal, the Basque Country in Spain, and the Kemerovo region in the Russian Federation. METHODS AND RESULTS: The Stent for Life economic model is based on a decision tree that incorporates primary percutaneous coronary intervention rates and mortality. Healthcare costs and indirect costs caused by loss of productivity were estimated. A baseline scenario simulating the status quo was compared to the Stent for Life scenario which integrated changes initiated by the Stent for Life programme. In the four model regions, primary percutaneous coronary intervention numbers rose substantially between 29-303%, while ST-elevation myocardial infarction mortality was reduced between 3-10%. Healthcare costs increased by 8% to 70%. Indirect cost savings ranged from 2-7%. Net societal costs were reduced in all model regions by 2-4%. CONCLUSION: The joint effort of the Stent for Life initiative and their local partners successfully saves lives. Moreover, the increase in healthcare costs was outweighed by indirect cost savings, leading to a net cost reduction in all four model regions. These findings demonstrate that systematic investments to improve the access of ST-elevation myocardial infarction patients to guideline-coherent therapy is beneficial, not only for the individual, but also for the society at large.

Plasma electrolytic titanium oxide applied for pathogenic bacteria inactivation.

Photocatalysis over TiO2 substrates is widely used in effluent treatment specially for organic compounds and for inactivation of pathogenic microorganisms. In the present work, TiO2 coatings were synthesized by plasma electrolytic oxidation (PEO) and its pathogenic bacteria inhibitory photoactivity was investigated. The photocatalytic activity of TiO2 coatings was investigated for the inactivation of Staphylococcus aureus and Salmonella bongori and the results were correlated with pore diameter and crystallite size. It was observed that both morphology and microstructure have an important role in the antibacterial photoactivity. The results show the larger the crystallite size and pore diameter the greater the photoactivity of the material. Porous materials that have a smaller pore diameter than the microorganism to be inactivated have low photoactivity. On the other hand, films that have pores with a diameter of the order or larger than the size of the microorganism to be inactivated present greater photocatalytic activity, once its pores allow the entrance and internal adsorption of the microorganisms, leading to the rupture of the cell membrane. Thus, in order to not sub-utilize the photocatalysts surface area, TiO2 coatings for using in microorganism inactivation must be synthesized with pore diameter bigger than the size of the microorganism.

Time to reperfusion in high-risk patients with myocardial infarction undergoing primary percutaneous coronary intervention.

INTRODUCTION: Timely reperfusion with primary percutaneous coronary intervention (PPCI) in ST-segment elevation myocardial infarction (STEMI) improves patient outcomes. In recent years, the Stent for Life (SFL) initiative in Portugal developed an action plan to improve timely access to PPCI. This study aims to evaluate performance indicators in high-risk populations (elderly, female, and diabetic patients). METHODS: Data on 1340 patients with suspected STEMI who were admitted to 18 Portuguese interventional cardiology centers were collected during a one-month period every year from 2011 to 2016. The risk of longer patient and system delay in elderly, female, and diabetic patients was assessed by logistic regression analysis. RESULTS: Patient and system delays were longer in elderly patients (incremental median 32 and 40 min; p=0.001 and p<0.001, respectively). Median system delay was also longer in women (incremental median 25 min; p<0.001). Consequently, times to revascularization were longer in elderly patients (incremental median 92 min; p<0.001) and women (incremental median 67 min; p<0.001). There was no significant difference in reperfusion delay in diabetic patients. After adjustment for gender and diabetes, elderly age was an independent predictor of patient delay longer than the median (OR 1.64; 95% CI 1.22-2.20; p=0.001) and system delay >90 min (OR 2.95; 95% CI 1.84-4.72; p<0.001). CONCLUSION: Elderly patients showed longer patient and system delays, regardless of gender and presence of diabetes. These data suggest that the elderly subgroup should be the target of a new action by the SFL initiative.

Self-Assembled Gold Arrays That Allow Rectification by Nanoscale Selectivity.

The deposition of a monolayer nanoarray on the surface of a micrometer-thick substrate is demonstrated, producing rectification characteristics at the nanoscale. The experimental results show that the heterogeneity of the structure and the charge density are the two key factors affecting rectification, which was confirmed with molecular dynamic (MD) and finite element simulations. Moreover, by altering the asymmetric electrolyte environment, the fabricated heterogeneous membrane can be used in energy conversion. This study provides insights into the mechanism underlying the generation of rectification and related factors, providing a theoretical basis for the characteristics of rectification.

The Stent for Life initiative: Factors predicting system delay in patients with ST-segment elevation myocardial infarction.

INTRODUCTION AND AIMS: System delay (time between first medical contact and reperfusion therapy) is an indicator of quality of primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) patients. This study aimed to assess changes in system delay between 2011 and 2015, and to identify its predictors. METHODS: The study included 838 patients admitted to 18 Portuguese interventional cardiology centers suspected of having STEMI with less than 12 hours' duration who were referred for primary percutaneous coronary intervention. Data were collected for a one-month period every year from 2011 to 2015. Univariate and multivariate logistic regression models were used to determine predictors of system delay. RESULTS: No significant changes in system delay were observed during the study. Only 27% of patients had a system delay of ≤90 min. Multivariate analysis identified four predictors of system delay: age ≥75 years (OR 2.57; 95% CI 1.50-4.59; p=0.001), attending a center without pPCI (OR 4.08; 95% CI 2.75-6.10; p<0.001), not calling the national medical emergency number (112) (OR 0.47; 95% CI 0.32-0.68; p<0.001), and Central region (OR 3.43; 95% CI 1.60-8.31; p=0.003). CONCLUSIONS: The factors age ≥75 years, attending a center without pPCI, not calling 112, and Central region were identified as predicting longer system delay. This knowledge may help in planning interventions to reduce system delay and to improve the clinical outcomes of patients with STEMI.

Factors influencing patient delay before primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: The Stent for life initiative in Portugal.

INTRODUCTION AND AIMS: Shorter patient delays are associated with a better prognosis for patients diagnosed with ST-segment elevation myocardial infarction (STEMI). This study aimed to identify predictors of patient delay in the Portuguese population. METHODS: Data on 994 patients with suspected STEMI of less than 12 hours' duration and referred for primary percutaneous coronary intervention (pPCI) and admitted to 18 Portuguese interventional cardiology centers were collected for a one-month period every year from 2011 to 2015. Univariate and multivariate linear regression models were used to identify predictors of patient delay. RESULTS: No significant differences were observed in patient delay over the course of the survey. The multivariate analysis identified five predictors of patient delay: age ≥75 years (exp[beta] 1.28; 95% CI 1.10-1.50; p=0.001), symptom onset between 0:00 and 8:00 a.m. (exp[beta] 1.26; 95% CI 1.10-1.45; p=0.001), and attending a primary care unit before first medical contact (exp[beta] 1.75; 95% CI 1.41-2.16; p<0.001) predicted longer patient delay, while calling the national medical emergency number (112) (exp[beta] 0.84; 95% CI 0.71-1.00; p=0.045) and transport by the emergency medical services to the pPCI facility (exp[beta] 0.71; 95% CI 0.59-0.84; p<0.001) predicted shorter patient delay. CONCLUSIONS: We identified five factors predicting patient delay, which will help in planning interventions to reduce patient delays and to improve the outcome of patients with STEMI.

Pristine carbon nitride as active material for high-performance metal-free supercapacitors: simple, easy and cheap.

Understanding the basic properties of pristine carbon nitride electrodes is of great importance for their further applications as supercapacitor materials. To this end, a comparative study of unmodified carbon nitride is crucial to understand the difference between the bare material and its composite counterparts described in the literature. Therefore, the aim of this paper is to explore the electrochemical behaviour of casting-produced C3N4 electrodes using cyclic voltammetry, charge/discharge curves and impedance spectroscopy. The results from this study show a capacitance value of 113.7 F g-1 at 0.2 A g-1 with an impressive retention of 89.2% after 5000 charge and discharge cycles at 3.0 A g-1. In addition, this material shows a large amount of specific energy (76.5 W h kg-1) at an operation power of 11.9 W kg-1, decreasing only 10.7% due to the electrochemical aging process. Hence, C3N4 constitutes a long-life pristine material with a large amount of energy and a moderate operation power with better performance than other C3N4-based composites found in the literature. These results are important to gain a better understanding of the inherent properties of carbon nitride - to further design composites with higher specific capacitance, longer lifetime, and specific energy.