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BACKGROUND: Rotational atherectomy (RA) is traditionally administered for patients with heavily calcified lesions and is thereby characterized by a high risk of the performed intervention. However, the prevalence characteristics of cardiac arrest are poorly studied in this group of patients. We aimed to evaluate the frequency and risk factors of cardiac arrest during percutaneous coronary interventions (PCI) performed with RA and preceding coronary angiography (CA). METHODS: Based on the data collected in the Polish Registry of Invasive Cardiology Procedures (ORPKI) from 2014 to 2021, we included 6522 patients who were treated with RA-assisted PCI. We scrutinized patient and procedural characteristics, as well as periprocedural complications, subsequently comparing groups in terms of cardiac arrest incidence with the use of univariable and multivariable analyses. RESULTS: Thirty-five (0.5%) patients suffered from cardiac arrest during RA-PCI or preceding CA. They were characterized by significantly higher rates of prior stroke, acute coronary syndromes (ACS) as indications and higher Killip class (P < 0.001) at the admission time. Among the confirmed independent predictors of in-procedure cardiac arrest, the following can be noted: factors related to patients' clinical characteristics (e.g., older age, female sex, and disease burden), periprocedural characteristics (e.g., PCI within left main coronary artery [LMCA]), and periprocedural complications (e.g., coronary artery perforation and no-reflow phenomenon). CONCLUSIONS: Severe clinical condition at baseline, expressed by ACS presence and Killip class IV, as well as RA-PCI performed within LMCA and other periprocedural complications, were the strongest predictors of cardiac arrest during RA-assisted PCI and CA.
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BACKGROUND: Differences between men and women in prognosis after sudden pre-hospital out-of-hospital cardiac arrest (OHCA) have been described in many studies, but the interplay between gender and pollution have not been characterized in detail. We aimed at appraising the interplay between gender and pollution on the prognosis of OHCA. METHODS: Details on patients with OHCA in whom return of spontaneous circulation was obtained and transferred to a large teaching hospital were obtained from the medical charts of the ambulance service and the Polish National Health Fund. Matching pollutant concentrations (PM 2.5, PM10, As, Ni, Cd, Pb) were obtained from the Polish National Environmental Protection Inspectorate. RESULTS: Details on 948 resuscitated OHCA, 325 (34.3%) of them in women, and occurring between 2018 and 2021, were retrieved. Notably, OHCA in women was associated with significantly higher daily concentrations of PM10 (23.37 [17.09, 37.04] vs. 21.92 [16.32, 29.98] µg/m3, P=0.023) and PM2.5 (16.83 [11.87, 28.24] vs. 15.27 [11.64, 22.72] µg/m3, P=0.026), as well as heightened concentrations of Cd, daily (0.32 [0.19, 0.44] vs. 0.27 [0.17, 0.40] ng/m3, P=0.027) and over 30 days (0.34 [0.20, 0.44] vs. 0.29 [0.18, 0.43] ng/m3, P=0.027). Concurrently, OHCA in females was associated with lower daily temperatures on the day of the incident (8.40 [0.20, 15.40] vs. 9.90 [1.40, 15.90] °C, P=0.042). Despite these differences, survival at 30 days and 12 months was similar in women and men (both P>0.05). CONCLUSIONS: OHCA events with successful resuscitation in women occurred in concomitance with higher daily contaminant levels, yet short-term and long-term prognosis was similar in men and women. The interplay between gender and air pollution on OHCA outcomes requires further population-based studies.
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Antiphospholipid syndrome (APS), also known as Hughes syndrome, is an acquired autoimmune and procoagulant condition that predisposes individuals to recurrent thrombotic events and obstetric complications. Central is the role of three types of antiphospholipid antibodies that target phospholipid-binding proteins: lupus anticoagulant (LAC), anti-ß2-glycoprotein I (ß2-GPI-Ab), and anti-cardiolipin (aCL). Together with clinical data, these antibodies are the diagnostic standard. However, the diagnosis of APS in older adults may be challenging and, in the diagnostic workup of thromboembolic complications, it is an underestimated etiology. The therapeutic management of APS requires distinguishing two groups with differential risks of thromboembolic complications. The standard therapy is based on low-dose aspirin in the low-risk group and vitamin K antagonists in the high-risk group. The value of direct oral anticoagulants is currently controversial. The potential role of monoclonal antibodies is investigated. For example, rituximab is currently recommended in catastrophic antiphospholipid antibody syndrome. Research is ongoing on other monoclonal antibodies, such as daratumumab and obinutuzumab. This narrative review illustrates the pathophysiological mechanisms of APS, with a particular emphasis on cardiovascular complications and their impact in older adults. This article also highlights advancements in the diagnosis, risk stratification, and management of APS.
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Polylactic acid (PLA), a polymer derived from renewable resources, is gaining increasing attention in the development of biomedical devices due to its cost-effectiveness, low immunogenicity, and biodegradability. However, its inherent hydrophobicity remains a problem, leading to poor cell adhesion features. On this basis, the aim of this work was to develop a method for functionalizing the surface of PLA films with a biopolymer, chitosan (CH), which was proved to be a material with intrinsic cell adhesive properties, but whose mechanical properties are insufficient to be used alone. The combination of the two polymers, PLA as a bulk scaffold and CH as a coating, could be a promising combination to develop a scaffold for cell growth. The modification of PLA films involved several steps: aminolysis followed by bromination to graft amino and then bromide groups, poly(glycidyl methacrylate) (PGMA) grafting by surface-initiated supplemental activator and reducing agent atom transfer radical polymerization (SI-SARA ATRP) and finally the CH grafting. To prove the effective adhesive properties, conjugated and non-conjugated films were tested in vitro as substrates for neuronal cell growth using differentiated neurons from human induced pluripotent stem cells. The results demonstrated enhanced cell growth in the presence of CH.
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Proliferação de Células , Quitosana , Neurônios , Poliésteres , Alicerces Teciduais , Quitosana/química , Poliésteres/química , Humanos , Alicerces Teciduais/química , Neurônios/citologia , Neurônios/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Polimerização , Adesão Celular/efeitos dos fármacos , Materiais Biocompatíveis/químicaRESUMO
An effective synthesis of conductive polymer brushes, i.e., self-templating surface-initiated copolymerization (ST-SICP), is developed. It proceeds through copolymerization of pendant thiophene groups in the precursor multimonomer poly(3-methylthienyl methacrylate) (PMTM) brushes with free 3-methylthiophene (3MT) monomers leading to PMTM-co-P3MT brushes. This approach leads to improved conformational freedom of generated conjugated poly(thiophene)-based chains and their higher share in the brushes with respect to conjugation of pendant thiophene groups only. As a result, best performing conjugated PMTM-co-P3MT brushes demonstrate high ohmic conductivity in both out-of-plane and in-plane direction. Furthermore, thanks to the covalent anchoring as well as intra- and intermolecular connections, highly stable and mechanically robust nanocoatings are produced which can survive mechanical cleaning and long-term storage under ambient conditions. Grafting of ionic poly(sodium 4-styrenesulfonate) (PSSNa) in between PMTM-co-P3MT chains brings new properties to such binary mixed brushes that can operate as thin-film memristive coating with switchable conductance. It is worth mentioning that the crucial synthetic steps, i.e., grafting of precursor PMTM brushes by surface-initiated organocatalyzed atom transfer radical polymerization (SI-O-ATRP) and PSSNa chains by surface-initiated photoiniferter-mediated polymerization (SI-PIMP) are conducted under ambient conditions using only microliter volumes of reagents providing methodology that can be considered for use beyond the laboratory scale.
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BACKGROUND: This study aims to investigate the effect of arsenic (As), cadmium (Cd), nickel (Ni) and lead (Pb) suspended on particulate matters (PM) 2.5 and PM 10 taking into account clinical factors on 30-day and one-year survival after out-of-hospital cardiac arrest (OHCA). METHODS: A retrospective 4-year study that involved patients hospitalized after OHCA. Patients' data were obtained from Emergency Medical Services dispatch cards and the National Health Fund. The concentration of air pollutants was measured by the Environmental Protection Inspectorate in Poland. RESULTS: Among the 948 patients after OHCA, only 225 (23.7%) survived for 30 days, and 153 (16.1%) survived for 1 year. Survivors were more commonly affected by OHCA in urban areas (85 [55.6%] vs. 355 [44.7%]; P=0.013) and had slightly higher one-year mean concentration of As (0.78 vs. 0.77; P=0.01), Cd (0.34 vs. 0.34; P=0.012), and Pb (11.13 vs. 10.20; P=0.015) with no differences in daily mean concentration. Significant differences in mean concentrations of heavy metals and PM 2.5 and PM 10 were observed among different quarters. However, survival analysis revealed no differences in long-term survival between quarters. Heavy metals, PM 2.5, and PM 10 did not affect short-term and long-term survival in multivariable logistic regression. CONCLUSIONS: The group of survivors showed slightly higher mean one-year concentrations of As, Cd and Pb, but they also experienced a higher incidence of OHCA in urban areas. There were no differences in long-term survival between patients who suffer OHCA in different quarters. Heavy metals did not independently affect survival.
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Metais Pesados , Parada Cardíaca Extra-Hospitalar , Humanos , Material Particulado/efeitos adversos , Parada Cardíaca Extra-Hospitalar/epidemiologia , Estudos Retrospectivos , Cádmio , Chumbo , Metais Pesados/análise , Sistema de RegistrosRESUMO
Views on the etiopathogenesis of atherosclerosis are subject to evolution. In addition to the classic well-known risk factors, new ones related to mental state, social life and environment are being discovered. Both acute and chronic stress stimulate inflammatory processes. Due to the change in lifestyle and eating habits, the accumulation of risk factors in childhood is an increasing problem. Knowledge of risk factors allows for effective primary prevention of cardiovascular diseases. The effectiveness of prevention increases when the activities cover the largest possible part of the society, and access to a doctor is easy. Therefore, government programs are being implemented offering patients easier access to diagnostics of cardiovascular diseases at the level of primary health care, which enables faster identification of people at the greatest cardiovascular risk. Easier access to primary care and a good doctor-patient relationship improve patient compliance. In this situation, the importance of the family doctor as a key link in the diagnosis, prevention and treatment of cardiovascular diseases is increasing.
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INTRODUCTION: Many factors related to the switch to summer/winter time interfere with biological rhythms. OBJECTIVES: This study aimed to analyze the impact of time change on clinical outcomes of patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). PATIENTS AND METHODS: Electronic data of 874,031 patients with ACS who underwent invasive procedures were collected from the Polish National Register of Interventional Cardiology Procedures (ORPKI) between 2014 and 2021. We determined the number of patients undergoing PCI and periprocedural mortality during the day of spring or autumn time change and within the first 3 and 7 days after the time change. RESULTS: We demonstrated the impact of time changes on the periprocedural mortality of ACS patients within 1 day and the period of 3 and 7 days from the time change. We observed that the occurrence of all ACS and NSTEMI on the first day was lower for both time changes and higher in the case of UA and spring time change. The autumn time change significantly reduced the occurrence of all types of ACS. A significant decrease in the number of invasive procedures was found after autumn transition in the period from the first day to 7 days for ACS, NSTEMI, and UA. CONCLUSIONS: The occurrence of ACS and the number of invasive procedures were lower for both changes over time. Autumn time change is associated with increased periprocedural mortality in ACS and a less frequent occurrence of UA and NSTEMI within 7 days.
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This article aimed to evaluate the visual and functional characteristics of intensively used football turf over 10 years, depending on the different areas of the game. The research was conducted on the football turf of the AZS Environmental Club in Wroclaw (N: 51° 7' 31'' E:17° 4' 14''). High variability of the evaluated parameters was observed regarding seasonality, year of observation, and the area of play. It has been shown that the goal area and penalty box areas have the lowest functional value, which are vital areas of the game from the point of view of gaining an advantage in the game. Also, these places are more susceptible to creating sites without plants (requiring additional overseeding) due to the potential of hollowing and goalkeeper interventions ending with the body landing on the ground. The middle area was characterized by the highest overall aspect, color, and turf density values. In the vast majority of cases, there was a downward trend in the turfs' functional value with the turf's age, which is an essential finding in the context of the use of intensively used, athletic natural grass surfaces.
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Poaceae , FutebolRESUMO
Introduction: Coronavirus disease 2019 (COVID-19) exacerbates intravascular thrombosis that occurs in the coronary artery in ST-elevation myocardial infarction (STEMI). Aim: To analyze the impact of COVID-19 on the application and effect of thrombectomy in STEMI patients. Material and methods: 29915 STEMI patients were analyzed, of whom 3139 (10.5%) underwent thrombectomy. COVID-19 (+) was reported in 311 (10.8%). The clinical characteristics and management of STEMI in COVID-19 (+) and COVID-19 (-) patients were compared. A multivariable logistic regression analysis was performed in search of factors influencing thrombectomy. Results: COVID-19 (+) patients had higher Killip class (IV class; n = 33 (12.31%) vs. n = 138 (5.84%); p < 0.0001) and cardiac arrest at baseline was more frequent in this group (n = 25 (8.04%) vs. n = 137 (4.84%); p = 0.016). Thrombolysis in myocardial infarction (TIMI) 3 after percutaneous coronary intervention was less frequent (n = 248 (80.52%) vs. n = 2388 (87.19%); p = 0.001) in the COVID-19 (-) group. Periprocedural mortality was similar in both groups (n = 28 (0.99%) vs. n = 4 (1.29%); p = 0.622). In multivariable regression analysis COVID-19 increased the risk of thrombectomy (OR = 1.23; 97.5% CI: 1.05-1.43; p = 0.001). Conclusions: STEMI patients undergoing aspiration thrombectomy who were COVID-19 (+) were more likely to be in a severe clinical condition (higher Killip class, more frequent cardiac arrest before the procedure) than COVID-19 (-) patients. Despite more intensive antiplatelet and anticoagulant treatment, PCI procedures were less likely to result in an optimal TIMI 3 effect. COVID-19 is an independent strong predictor of patient qualification for aspiration thrombectomy in STEMI.
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Controlling cellular adhesion is a critical step in the development of biomaterials, and in cell- based biosensing assays. Usually, the adhesivity of cells is tuned by an appropriate biocompatible layer. Here, synthetic poly(diallyldimethylammonium chloride) (PDADMAC), natural chitosan, and heparin (existing in an extracellular matrix) were selected to assembly PDADMAC/heparin and chitosan/heparin films. The physicochemical properties of macroion multilayers were determined by streaming potential measurements (SPM), quartz crystal microbalance (QCM-D), and optical waveguide lightmode spectroscopy (OWLS). The topography of the wet films was imaged using atomic force microscopy (AFM). The adhesion of preosteoblastic cell line MC3T3-E1 on those well-characterized polysaccharide-based multilayers was evaluated using a resonant waveguide grating (RWG) based optical biosensor and digital holographic microscopy. The latter method was engaged to investigate long-term cellular behavior on the fabricated multilayers. (PDADMAC/heparin) films were proved to be the most effective in inducing cellular adhesion. The cell attachment to chitosan/heparin-based multilayers was negligible. It was found that efficient adhesion of the cells occurs onto homogeneous and rigid multilayers (PDADMAC/heparin), whereas the macroion films forming "sponge-like" structures (chitosan/heparin) are less effective, and could be employed when reduced adhesion is needed. Polysaccharide-based multilayers can be considered versatile systems for medical applications. One can postulate that the presented results are relevant not only for modeling studies but also for applied research.
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Técnicas Biossensoriais , Quitosana , Quitosana/química , Polissacarídeos/farmacologia , Heparina/farmacologia , Heparina/química , Adesão Celular , Propriedades de SuperfícieRESUMO
BACKGROUND: Intravascular ultrasound (IVUS) and fractional flow reserve (FFR) are invasive procedures increasingly used in treating acute coronary syndrome (ACS). AIMS: This study aimed to evaluate the frequency of IVUS and FFR use in patients with ACS in Poland and to assess the safety of these procedures as well as their impact on short- and long-term survival. METHODS AND RESULTS: This retrospective study included 103849 patients enrolled in the Polish Registry of Acute Coronary Syndromes in 2017-2020. IVUS was performed in 1727 patients, FFR in 1537 patients, and both procedures in 37 patients. The frequency of performing FFR in ACS patients increased over the years from 1.3% to 1.8% (P <0.0001) and IVUS from 1.7% to 2.3% (P <0.0001). In the FFR and/or IVUS group, a similar incidence of stroke, reinfarction, target vessel revascularization, and major bleeding was observed while in-hospital mortality was lower (0% for IVUS + FFR vs. 0.9% for FFR vs. 2.3% for IVUS vs. 3.7 for no procedure; P <0.0001). FFR and IVUS did not affect the 30-day and one-year prognosis. CONCLUSION: In recent years, the number of FFR and IVUS procedures performed in patients with ACS in Poland has increased. There was lower in-hospital mortality in the FFR and/or IVUS group in ACS patients, and no differences in the incidence of stroke, reinfarction, target vessel revascularization, and major bleeding were observed. Performing FFR and IVUS in ACS patients does not significantly affect 30-day or one-year mortality.
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Síndrome Coronariana Aguda , Estenose Coronária , Reserva Fracionada de Fluxo Miocárdico , Humanos , Síndrome Coronariana Aguda/diagnóstico por imagem , Síndrome Coronariana Aguda/terapia , Polônia , Estudos Retrospectivos , Ultrassonografia de Intervenção/métodos , Sistema de Registros , Angiografia Coronária , Estenose Coronária/terapiaRESUMO
HYPOTHESIS: Mixed polymer brushes (MPBs) could be synthesized by surface dilution of homopolymer brushes and subsequent grafting of other type of chains in the formed voids. Nanophase separation and dynamics of surface-grafted chains could be tailored by modification of their molecular architecture. Mixed polyelectrolyte and conjugated chains contribute synergistically to tailor properties of the coating. EXPERIMENTS: A new synthetic strategy that allowed spatially controlled grafting of poly(sodium 4-styrenesulfonate) chains (PSSNa) in close neighborhood of poly(3-methylthienyl methacrylate) (PMTM) brushes (precursors of the conjugated chains) using surface-initiated polymerizations was developed. The final mixed conjugated/polyelectrolyte brushes were prepared by template polymerization of pendant thiophene groups in PMTM chains. Surface dynamics and nanophase separation of MPBs were studied by nanoscale resolution IR imaging, SIMS profiling and AFM mapping in selective solvents. FINDINGS: Unconjugated MPBs were shown to undergo vertical, and horizontal nanophase separation, while the size and shape of the nanodomains were dependent on molar ratio of the mixed chains and their relative lengths. Generation of the conjugated chains led to diminishing of nanophase separation thanks to stronger mutual interactions of conjugated PMTM and PSSNa (macromolecular mixing). The obtained systems demonstrated tunable interfacial structure and resistance switching phenomenon desired in construction of smart surfaces or memristive devices.
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Metacrilatos , Polímeros , Polieletrólitos , Propriedades de Superfície , Polímeros/química , Metacrilatos/químicaRESUMO
Air pollution and COVID-19 infection affect the pathogenesis of cardiovascular disease. The impact of these factors on the course of ACS treatment is not well defined. The purpose of this study was to evaluate the effects of air pollution, COVID-19 infection, and selected clinical factors on the occurrence of perioperative death in patients with acute coronary syndrome (ACS) by developing a neural network model. This retrospective study included 53,076 patients with ACS from the ORPKI registry (National Registry of Invasive Cardiology Procedures) including 2395 COVID-19 (+) patients and 34,547 COVID-19 (-) patients. The neural network model developed included 57 variables, had high performance in predicting perioperative patient death, and had an error risk of 0.03%. Based on the analysis of the effect of permutation on the variable, the variables with the greatest impact on the prediction of perioperative death were identified to be vascular access, critical stenosis of the left main coronary artery (LMCA) or left anterior descending coronary artery (LAD). Air pollutants and COVID-19 had weaker effects on end-point prediction. The neural network model developed has high performance in predicting the occurrence of perioperative death. Although COVID-19 and air pollutants affect the prediction of perioperative death, the key predictors remain vascular access and critical LMCA or LAD stenosis.
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Síndrome Coronariana Aguda , Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Estenose Coronária , Humanos , Estenose Coronária/patologia , Estenose Coronária/terapia , Síndrome Coronariana Aguda/epidemiologia , Constrição Patológica , Estudos Retrospectivos , Angiografia Coronária , Poluição do Ar/efeitos adversosRESUMO
An impaired fibrinolytic process has been demonstrated in patients infected with SARS-CoV-2, including those in severe or critical condition. Disruption of fibrinolysis leads to fibrin deposition, which exacerbates inflammation and fibrosis and damages the pulmonary surfactant. Numerous authors point out the different course of coagulopathy in patients with COVID-19. It is reported that they may have a state of secondary hyperfibrinolysis, which may explain, at least in part, the increased incidence of venous thromboembolism, even among those patients already receiving appropriate anticoagulant treatment. This raises the question of whether current guidelines for the prevention and treatment of embolic-thrombotic complications, among patients with severe COVID-19, are sufficient. Some studies show evidence of clinical improvement in patients who have received fibrinolytic therapy, beyond the current indications for its implementation. However, when considering the inclusion of systemic fibrinolytic therapy, the benefits of such treatment should always be weighed over the risk of adverse effects. Thromboelastography and rotational thromboelastometry can be helpful in making such decisions. The purpose of this study was to review the current knowledge regarding fibrinolysis and its role in the treatment of patients with severe COVID-19, including those with thromboembolic complications.
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COVID-19 causes thromboembolic complications that affect the patient's prognosis. COVID-19 vaccines significantly improve the prognosis for the course of the infection. The aim of this study was to evaluate the impacts of patient characteristics, including COVID-19 vaccinations, on perioperative mortality in acute coronary syndrome in Poland during the pandemic. We analyzed the data of 243,515 patients from the National Registry of Invasive Cardiology Procedures (Ogólnopolski Rejestr Procedur Kardiologii Inwazyjnej [ORPKI]). In this group, 7407 patients (21.74%) had COVID-19. The statistical analysis was based on a neural network that was verified by the random forest method. In 2020, the most significant impact on prognosis came from a diagnosis of unstable angina, a short period (<2 h) from pain occurrence to first medical contact, and a history of stroke. In 2021, the most significant factors were pre-hospital cardiac arrest, female sex, and a short period (<2 h) from first medical contact to coronary angiography. After adjusting for a six-week lag, a diagnosis of unstable angina and psoriasis were found to be relevant in the data from 2020, while in 2021, it was the time from the pain occurrence to the first medical contact (2−12 h) in non-ST segment elevation myocardial infarction and the time from first contact to balloon inflation (2−12 h) in ST-segment elevation myocardial infarction. The number of vaccinations was one of the least significant factors. COVID-19 vaccination does not directly affect perioperative prognosis in patients with acute coronary syndrome.
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The preparation of composite materials is a promising methodology for concurrent optimization of electrical and thermal transport properties for improved thermoelectric (TE) performance. This study demonstrates how the acoustic impedance mismatch (AIM) and the work function of components decouple the TE parameters to achieve enhanced TE performance of the (1-z)Ge0.87Mn0.05Sb0.08Te-(z)WC composite. The simultaneous increase in the electrical conductivity (σ) and Seebeck coefficient (α) with WC (tungsten carbide) volume fraction (z) results in an enhanced power factor (α2σ) in the composite. The rise in σ is attributed to the creation of favorable current paths through the WC phase located between grains of Ge0.87Mn0.05Sb0.08Te, which leads to increased carrier mobility in the composite. Detailed analysis of the obtained electrical properties was performed via Kelvin probe force microscopy (work function measurement) and atomic force microscopy techniques (spatial current distribution map and current-voltage (I-V) characteristics), which are further supported by density functional theory (DFT) calculations. Furthermore, the difference in elastic properties (i.e., sound velocity) between Ge0.87Mn0.05Sb0.08Te and WC results in a high AIM, and hence, a large interface thermal resistance (Rint) between the phases is achieved. The correlation between Rint and the Kapitza radius depicts a reduced phonon thermal conductivity (κph) of the composite, which is explained using the Bruggeman asymmetrical model. Moreover, the decrease in κph is further validated by phonon dispersion calculations that indicate the decrease in phonon group velocity in the composite. The simultaneous effect of enhanced α2σ and reduced κph results in a maximum figure of merit (zT) of 1.93 at 773 K for (1-z)Ge0.87Mn0.05Sb0.08Te-(z)WC composite for z = 0.010. It results in an average thermoelectric figure of merit (zTav) of 1.02 for a temperature difference (ΔT) of 473 K. This study shows promise to achieve higher zTav across a wide range of composite materials.
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The high stability and conductivity of 3,4-disubstituted polythiophenes such as poly(3,4-ethylenedioxythiophene) (PEDOT) make them attractive candidates for commercial applications. However, next-generation nanoelectronic devices require novel macromolecular strategies for the precise synthesis of advanced polymer structures as well as their arrangement. In this report, we present a synthetic route to make ladder-like polymer brushes with poly(3,4-propylenedioxythiophene) (PProDOT)-conjugated chains. The brushes were prepared via a self-templating surface-initiated technique (ST-SIP) that combines the surface-initiated atom transfer radical polymerization (SI-ATRP) of bifunctional ProDOT-based monomers and subsequent oxidative polymerization of the pendant ProDOT groups in the parent brushes. The brushes prepared in this way were characterized by grazing-angle FTIR, XPS spectroscopy, and AFM. Steady-state and time-resolved photoluminescence measurements were used to extract the information about the structure and effective conjugation length of PProDOT-based chains. Stability tests performed in ambient conditions and under exposure to standardized solar light revealed the remarkable stability of the obtained materials.
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Polímeros , Polimerização , Polímeros/química , Propriedades de SuperfícieRESUMO
DNA origami is a widely used DNA nanotechnology that allows construction of two-dimensional and three-dimensional nanometric shapes. The designability and rigidity of DNA origami make it an ideal material for construction of topologically linked molecules such as catenanes, which are attractive for their potential as motors and molecular machines. However, a general method for production of topologically linked DNA origami has been lacking. Here, we show that catenated single-stranded DNA circles can be produced and used as a universal scaffold for the production of topologically linked (catenated) DNA origami structures where the individual linked structures can be of any arbitrary design. Assembly of these topologically linked DNA origami structures is achieved via a simple one-pot annealing protocol.
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The article presents the modification of ash wood via surface initiated activators regenerated by electron transfer atom transfer radical polymerization mediated by elemental silver (Ag0 SI-ARGET ATRP) at a diminished catalyst concentration. Ash wood is functionalized with poly(methyl methacrylate) (PMMA) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) to yield wood grafted with PMMA-b-PDMAEMA-Br copolymers with hydrophobic and antibacterial properties. Fourier transform infrared (FT-IR) spectroscopy confirmed the covalent incorporation of functional ATRP initiation sites and polymer chains into the wood structure. The polymerization kinetics was followed by the analysis of the polymer grown in solution from the sacrificial initiator by proton nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The polymer layer covalently attached to the wood surface was observed by scanning electron microscopy (SEM). The hydrophobic properties of hybrid materials were confirmed by water contact angle measurements. Water and sodium chloride salt aqueous solution uptake tests confirmed a significant improvement in resistance to the absorption of wood samples after modification with polymers. Antibacterial tests revealed that wood-QPDMAEMA-Br, as well as wood-PMMA-b-QPDMAEMA-Br, exhibited higher antibacterial activity against Gram-positive bacteria (Staphylococcus aureus) in comparison with Gram-negative bacteria (Escherichia coli). The paper presents an economic concept with ecological aspects of improving wood properties, which gives great opportunities to use the proposed approach in the production of functional hybrid materials for industry and high quality sports equipment, and in furniture production.