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There is great interest in the development of prosthetic limbs capable of complex activities that are wirelessly connected to the patient's neural system. Although some progress has been achieved in this area, one of the main problems encountered is the selective acquisition of nerve impulses and the closing of the automation loop through the selective stimulation of the sensitive branches of the patient. Large-scale research and development have achieved so-called "cuff electrodes"; however, they present a big disadvantage: they are not selective. In this article, we present the progress made in the development of an implantable system of plug neural microelectrodes that relate to the biological nerve tissue and can be used for the selective acquisition of neuronal signals and for the stimulation of specific nerve fascicles. The developed plug electrodes are also advantageous due to their small thickness, as they do not trigger nerve inflammation. In addition, the results of the conducted tests on a sous scrofa subject are presented.
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Antebraço , Inflamação , Humanos , Eletrodos Implantados , Potenciais de Ação , AutomaçãoRESUMO
BACKGROUND: Scarce data exist on the evolution of device-related thrombus (DRT) after left atrial appendage closure (LAAC). OBJECTIVES: This study sought to assess the incidence, predictors, and clinical impact of persistent and recurrent DRT in LAAC recipients. METHODS: Data were obtained from an international multicenter registry including 237 patients diagnosed with DRT after LAAC. Of these, 214 patients with a subsequent imaging examination after the initial diagnosis of DRT were included. Unfavorable evolution of DRT was defined as either persisting or recurrent DRT. RESULTS: DRT resolved in 153 (71.5%) cases and persisted in 61 (28.5%) cases. Larger DRT size (OR per 1-mm increase: 1.08; 95% CI: 1.02-1.15; P = 0.009) and female (OR: 2.44; 95% CI: 1.12-5.26; P = 0.02) were independently associated with persistent DRT. After DRT resolution, 82 (53.6%) of 153 patients had repeated device imaging, with 14 (17.1%) cases diagnosed with recurrent DRT. Overall, 75 (35.0%) patients had unfavorable evolution of DRT, and the sole predictor was average thrombus size at initial diagnosis (OR per 1-mm increase: 1.09; 95% CI: 1.03-1.16; P = 0.003), with an optimal cutoff size of 7 mm (OR: 2.51; 95% CI: 1.39-4.52; P = 0.002). Unfavorable evolution of DRT was associated with a higher rate of thromboembolic events compared with resolved DRT (26.7% vs 15.1%; HR: 2.13; 95% CI: 1.15-3.94; P = 0.02). CONCLUSIONS: About one-third of DRT events had an unfavorable evolution (either persisting or recurring), with a larger initial thrombus size (particularly >7 mm) portending an increased risk. Unfavorable evolution of DRT was associated with a 2-fold higher risk of thromboembolic events compared with resolved DRT.
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Apêndice Atrial , Fibrilação Atrial , Acidente Vascular Cerebral , Tromboembolia , Trombose , Humanos , Feminino , Incidência , Apêndice Atrial/diagnóstico por imagem , Resultado do Tratamento , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/terapia , Fibrilação Atrial/complicações , Tromboembolia/diagnóstico por imagem , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Trombose/diagnóstico por imagem , Trombose/epidemiologia , Trombose/etiologia , Acidente Vascular Cerebral/etiologiaRESUMO
Healthcare professionals face an ongoing challenge in managing both acute and chronic wounds, given the potential impact on patients' quality of life and the limited availability of expensive treatment options. Hydrogel wound dressings offer a promising solution for effective wound care due to their affordability, ease of use, and ability to incorporate bioactive substances that enhance the wound healing process. Our study aimed to develop and evaluate hybrid hydrogel membranes enriched with bioactive components such as collagen and hyaluronic acid. We utilized both natural and synthetic polymers and employed a scalable, non-toxic, and environmentally friendly production process. We conducted extensive testing, including an in vitro assessment of moisture content, moisture uptake, swelling rate, gel fraction, biodegradation, water vapor transmission rate, protein denaturation, and protein adsorption. We evaluated the biocompatibility of the hydrogel membranes through cellular assays and performed instrumental tests using scanning electron microscopy and rheological analysis. Our findings demonstrate that the biohybrid hydrogel membranes exhibit cumulative properties with a favorable swelling ratio, optimal permeation properties, and good biocompatibility, all achieved with minimal concentrations of bioactive agents.
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BACKGROUND: A paravalvular leak (PVL) is a complication following valve replacement, which may lead to heart failure and hemolysis. The aim of this study is to investigate whether the clinical outcome after transcatheter PVL closure differs according to the prominent indication of the procedure (symptoms of heart failure or hemolysis). METHODS: The data of consecutive patients who had transcatheter treatment for PVL between July 2011 and September 2022 in five Greek centers were analyzed. The primary endpoint was the technical, and clinical success rates with regards to the prominent indication of paravalvular leak closure. The secondary endpoints included the evaluation and comparison of the clinical and technical success in relation to the type of valve that was treated (aortic or mitral) as well as the survival analysis in relation to the closure indication and type of valve that was treated. RESULTS: In total, 60 patients were retrospectively studied (39% men, mean age 69.5 ± 11 years). Regarding the primary outcomes, the technical success in patients mainly suffering from hemolysis was 86.1%, while in those presenting heart failure it was 95.8%, p = 0.387. Furthermore, the clinical success was 72.2% and 87.5% among hemolysis and heart failure patients, respectively, p = 0.210. During the follow-up period, the two-year survival rates were significantly better for patients treated for the aortic valve (78.94%) compared to those in the mitral position (48.78%), p = 0.014. In total, 25 patients died (41.7%) during 24 months of follow-up. CONCLUSIONS: Transcatheter paravalvular leak closure can be performed with high technical and clinical success rates without any difference according to the prominent indication of closure.
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Detection of greenhouse gases is essential because harmful gases in the air diffuse rapidly over large areas in a short period of time, causing air pollution that will induce climate change with catastrophic consequences over time. Among the materials with favorable morphologies for gas detection (nanofibers, nanorods, nanosheets), large specific surfaces, high sensitivity and low production costs, we chose nanostructured porous films of In2O3 obtained by the sol-gel method, deposited on alumina transducers, with gold (Au) interdigitated electrodes (IDE) and platinum (Pt) heating circuits. Sensitive films contained 10 deposited layers, involving intermediate and final thermal treatments to stabilize the sensitive film. The fabricated sensor was characterized using AFM, SEM, EDX and XRD. The film morphology is complex, containing fibrillar formations and some quasi-spherical conglomerates. The deposited sensitive films are rough, thus favoring gas adsorption. Ozone sensing tests were performed at different temperatures. The highest response of the ozone sensor was recorded at room temperature, considered to be the working temperature for this specific sensor.
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Undoped and Zn-doped ITO (ITO:Zn) multifunctional thin films were successfully synthesized using the sol-gel and dipping method on three different types of substrates (glass, SiO2/glass, and Si). The effect of Zn doping on the optoelectronic, microstructural, and gas-sensing properties of the films was investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), spectroscopic ellipsometry (SE), Raman spectroscopy, Hall effect measurements (HE), and gas testing. The results showed that the optical constants, the transmission, and the carrier numbers were correlated with the substrate type and with the microstructure and the thickness of the films. The Raman study showed the formation of ITO films and the incorporation of Zn in the doped film (ITO:Zn), which was confirmed by EDX analysis. The potential use of the multifunctional sol-gel ITO and ITO:Zn thin films was proven for TCO applications or gas-sensing experiments toward CO2. The Nyquist plots and equivalent circuit for fitting the experimental data were provided. The best electrical response of the sensor in CO2 atmosphere was found at 150 °C, with activation energy of around 0.31 eV.
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In this article, we present our research achievements regarding the development of a remote sensing system for motor pulse acquisition, as a first step towards a complete neuroprosthetic arm. We present the fabrication process of an implantable electrode for nerve impulse acquisition, together with an innovative wirelessly controlled system. In our study, these were combined into an implantable device for attachment to peripheral nerves. Mechanical and biocompatibility tests were performed, as well as in vivo testing on pigs using the developed system. This testing and the experimental results are presented in a comprehensive manner, demonstrating that the system is capable of accomplishing the requirements of its designed application. Most significantly, neural electrical signals were acquired and transmitted out of the body during animal experiments, which were conducted according to ethical regulations in the field.
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Sistema Nervoso Periférico , Tecnologia de Sensoriamento Remoto , Potenciais de Ação , Animais , Eletrodos Implantados , Nervos Periféricos/fisiologia , SuínosRESUMO
Nanocomposite materials have seen increased adoption in a wide range of applications, with toxic gas detection, such as carbon monoxide (CO), being of particular interest for this review. Such sensors are usually characterized by the presence of CO absorption sites in their structures, with the Langmuir reaction model offering a good description of the reaction mechanism involved in capturing the gas. Among the reviewed sensors, those that combined polymers with carbonaceous materials showed improvements in their analytical parameters such as increased sensitivities, wider dynamic ranges, and faster response times. Moreover, it was observed that the CO reaction mechanism can differ when measured in mixtures with other gases as opposed to when it is detected in isolation, which leads to lower sensitivities to the target gas. To better understand such changes, we offer a complete description of carbon nanostructure-based chemosensors for the detection of CO from the sensing mechanism of each material to the water solution strategies for the composite nanomaterials and the choice of morphology for enhancing a layers' conductivity. Then, a series of state-of-the-art resistive chemosensors that make use of nanocomposite materials is analyzed, with performance being assessed based on their detection range and sensitivity.
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Green chemistry is a pharmaceutical industry tool, which, when implemented correctly, can lead to a minimization in resource consumption and waste. An aqueous extract of Salix alba L. was employed for the efficient and rapid synthesis of silver/gold particle nanostructures via an inexpensive, nontoxic and eco-friendly procedure. The nanoparticles were physicochemically characterized using ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), X-ray diffraction (XRD) and scanning electron microscopy (SEM), with the best stability of up to one year in the solution obtained for silver nanoparticles without any chemical additives. A comparison of the antimicrobial effect of silver/gold nanoparticles and their formulations (hydrogels, ointments, aqueous solutions) showed that both metallic nanoparticles have antibacterial and antibiofilm effects, with silver-based hydrogels having particularly high antibiofilm efficiency. The highest antibacterial and antibiofilm efficacies were obtained against Pseudomonas aeruginosa when using silver nanoparticle hydrogels, with antibiofilm efficacies of over 75% registered. The hydrogels incorporating green nanoparticles displayed a 200% increased bacterial efficiency when compared to the controls and their components. All silver nanoparticle formulations were ecologically obtained by "green synthesis" and were shown to have an antimicrobial effect or potential as keratinocyte-acting pharmaceutical substances for ameliorating infectious psoriasis wounds.
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Recently the emissions of volatile organic compounds (VOCs) in the atmosphere have increased dramatically with rapid development of urbanization and industry. This led to a large decline in air quality around the world, which resulted in a heavy impact on human health. Therefore, new/cheap detection devices for VOCs are of high interest. Formaldehyde (FA) is a very toxic VOC, which damages the respiratory system even in the smallest doses and short exposure time. Zinc oxide (ZnO)/nickel oxide (NiO) heterostructures were synthesized using an economical route: firstly, NiO was prepared by liquid exfoliation technique and deposited by dip-coating on alumina ceramic transducers with two interdigital gold (Au) electrodes, followed by low-temperature hydrothermal growth of ZnO. The as-prepared sensors were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM-EDAX), and X-Ray fluorescence (XRF). The response/recovery of ZnO/NiO heterostructure-based microsensors for formaldehyde was investigated at room temperature, in agreement with modern sensing requirements. The sensor operating voltage was varied between 1.5 and 5.0 V direct current (DC), to achieve the best sensor performance.
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BACKGROUND: Device-related thrombus (DRT) has been considered an Achilles' heel of left atrial appendage occlusion (LAAO). However, data on DRT prediction remain limited. OBJECTIVES: This study constructed a DRT registry via a multicenter collaboration aimed to assess outcomes and predictors of DRT. METHODS: Thirty-seven international centers contributed LAAO cases with and without DRT (device-matched and temporally related to the DRT cases). This study described the management patterns and mid-term outcomes of DRT and assessed patient and procedural predictors of DRT. RESULTS: A total of 711 patients (237 with and 474 without DRT) were included. Follow-up duration was similar in the DRT and no-DRT groups, median 1.8 years (interquartile range: 0.9-3.0 years) versus 1.6 years (interquartile range: 1.0-2.9 years), respectively (P = 0.76). DRTs were detected between days 0 to 45, 45 to 180, 180 to 365, and >365 in 24.9%, 38.8%, 16.0%, and 20.3% of patients. DRT presence was associated with a higher risk of the composite endpoint of death, ischemic stroke, or systemic embolization (HR: 2.37; 95% CI, 1.58-3.56; P < 0.001) driven by ischemic stroke (HR: 3.49; 95% CI: 1.35-9.00; P = 0.01). At last known follow-up, 25.3% of patients had DRT. Discharge medications after LAAO did not have an impact on DRT. Multivariable analysis identified 5 DRT risk factors: hypercoagulability disorder (odds ratio [OR]: 17.50; 95% CI: 3.39-90.45), pericardial effusion (OR: 13.45; 95% CI: 1.46-123.52), renal insufficiency (OR: 4.02; 95% CI: 1.22-13.25), implantation depth >10 mm from the pulmonary vein limbus (OR: 2.41; 95% CI: 1.57-3.69), and non-paroxysmal atrial fibrillation (OR: 1.90; 95% CI: 1.22-2.97). Following conversion to risk factor points, patients with ≥2 risk points for DRT had a 2.1-fold increased risk of DRT compared with those without any risk factors. CONCLUSIONS: DRT after LAAO is associated with ischemic events. Patient- and procedure-specific factors are associated with the risk of DRT and may aid in risk stratification of patients referred for LAAO.
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Apêndice Atrial/cirurgia , Fibrilação Atrial/cirurgia , Cateterismo Cardíaco/efeitos adversos , Complicações Pós-Operatórias/etiologia , Sistema de Registros , Dispositivo para Oclusão Septal/efeitos adversos , Trombose/etiologia , Idoso , Apêndice Atrial/diagnóstico por imagem , Ecocardiografia Transesofagiana , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Cardiopatias/diagnóstico , Cardiopatias/epidemiologia , Cardiopatias/etiologia , Humanos , Incidência , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Fatores de Risco , Taxa de Sobrevida/tendências , Trombose/diagnóstico , Trombose/epidemiologia , Fatores de Tempo , Resultado do TratamentoRESUMO
The impact of the antiplatelet regimen and the extent of associated platelet inhibition on cerebrovascular microembolic events during transcatheter aortic valve implantation (TAVI) are unknown. Our aim was to evaluate the effects of ticagrelor versus clopidogrel and of platelet inhibition on the number of cerebrovascular microembolic events in patients undergoing TAVI. Patients scheduled for TAVI were randomized previous to the procedure to either aspirin and ticagrelor or to aspirin and clopidogrel. Platelet inhibition was expressed in P2Y12 reaction units (PRU) and percentage of inhibition. High intensity transient signals (HITS) were assessed with transcranial Doppler (TCD). Safety outcomes were recorded according to the VARC-2 definitions. Among 90 patients randomized, 6 had an inadequate TCD signal. The total number of procedural HITS was lower in the ticagrelor group (416.5 [324.8, 484.2]) (42 patients) than in the clopidogrel group (723.5 [471.5, 875.0]) (42 patients), p <0.001. After adjusting for the duration of the procedure, diabetes, extra-cardiac arteriopathy, BMI, hypertension, aortic valve calcium content, procedural ACT, and pre-implantation balloon valvuloplasty, patients on ticagrelor had on average 256.8 (95% CI: [-335.7, -176.5]) fewer total procedural HITS than patients on clopidogrel. Platelet inhibition was greater with ticagrelor 26 [10, 74.5] PRU than with clopidogrel 207.5 (120 to 236.2) PRU, p <0.001, and correlated significantly with procedural HITS (r = 0.5, p <0.05). In conclusion, ticagrelor resulted in fewer procedural HITS, compared with clopidogrel, in patients undergoing TAVI, while achieving greater platelet inhibition.
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Estenose da Valva Aórtica/cirurgia , Aspirina/uso terapêutico , Clopidogrel/uso terapêutico , Embolia Intracraniana/prevenção & controle , Complicações Intraoperatórias/prevenção & controle , Inibidores da Agregação Plaquetária/uso terapêutico , Ticagrelor/uso terapêutico , Substituição da Valva Aórtica Transcateter/métodos , Idoso , Idoso de 80 Anos ou mais , Terapia Antiplaquetária Dupla/métodos , Feminino , Humanos , Embolia Intracraniana/diagnóstico por imagem , Embolia Intracraniana/epidemiologia , Complicações Intraoperatórias/diagnóstico por imagem , Complicações Intraoperatórias/epidemiologia , Masculino , Ultrassonografia Doppler TranscranianaRESUMO
Developing a sensing layer with high electroactive properties is an important aspect for proper functionality of a wearable sensor. The polymeric nanocomposite material obtained by a simple electropolymerization on gold interdigitated electrodes (IDEs) can be optimized to have suitable conductive properties to be used with direct current (DC) measurements. A new layer based on polyaniline:poly(4-styrenesulfonate) (PANI:PSS)/single-walled carbon nanotubes (SWCNT)/ferrocene (Fc) was electrosynthesized and deposed on interdigital transducers (IDT) and was characterized in detail using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoemission spectroscopy (XPS), and X-ray diffraction (XRD). The sensor characteristics of the material towards carbon monoxide (CO) in the concentration range of 10-300 ppm were examined, showing a minimal relative humidity interference of only 1% and an increase of sensitivity with the increase of CO concentration. Humidity interference could be controlled by the number of CV cycles when a compact layer was formed and the addition of Fc played an important role in the decrease of humidity. The results for CO detection can be substantially improved by optimizing the number of deposition cycles and enhancing the Fc concentration. The material was developed for selective detection of CO in real environmental conditions and shows good potential for use in a wearable sensor.
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Nanotubos de Carbono , Dispositivos Eletrônicos Vestíveis , Eletrodos , Ouro , MetalocenosRESUMO
The low-power sensing platform proposed by the Convergence project is foreseen as a wireless, low-power and multifunctional wearable system empowered by energy-efficient technologies. This will allow meeting the strict demands of life-style and healthcare applications in terms of autonomy for quasi-continuous collection of data for early-detection strategies. The system is compatible with different kinds of sensors, able to monitor not only health indicators of individual person (physical activity, core body temperature and biomarkers) but also the environment with chemical composition of the ambient air (NOx, COx, NHx particles) returning meaningful information on his/her exposure to dangerous (safety) or pollutant agents. In this article, we introduce the specifications and the design of the low-power sensing platform and the different sensors developed in the project, with a particular focus on pollutant sensing capabilities and specifically on NO2 sensor based on graphene and CO sensor based on polyaniline ink.
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Grafite , Dispositivos Eletrônicos Vestíveis , Feminino , Humanos , Masculino , Monitorização FisiológicaRESUMO
In recent years, research into the field of materials for flexible sensors and fabrication techniques directed towards wearable devices has helped to raise awareness of the need for new sensors with healthcare applicability. Our goal was to create a wearable flexible pressure sensor that could be integrated into a clinically approved blood pressure monitoring device. The sensor is built from a microfluidic channel encapsulated between two polymer layers, one layer being covered by metal transducers and the other being a flexible membrane containing the microfluidic channel, which also acts as a sealant for the structure. The applied external pressure deforms the channel, causing changes in resistance to the microfluidic layer. Electrical characterization has been performed in 5 different configurations, using alternating current (AC) and (DC) direct current measurements. The AC measurements for the fabricated pressure sensor resulted in impedance values at tens of hundreds of kOhm. Our sensor proved to have a high sensitivity for pressure values between 0 and 150 mm Hg, being subjected to repeatable external forces. The novelty presented in our work consists in the unique technological flow for the fabrication of the flexible wearable pressure sensor. The proposed miniaturized pressure sensor will ensure flexibility, low production cost and ease of use. It is made of very sensitive microfluidic elements and biocompatible materials and can be integrated into a wearable cuffless device for continuous blood pressure monitoring.
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Dispositivos Eletrônicos Vestíveis , Pressão Sanguínea , Impedância Elétrica , Microfluídica , Monitorização FisiológicaRESUMO
BACKGROUND: Paravalvular leak (PVL) is a common complication following valve replacement, which leads to heart failure and hemolysis. Transcatheter PVL closure has emerged as a reliable alternative with promising results. We quote the combined three-center experience of PVL patients treated percutaneously. METHODS: Consecutive patients treated percutaneously for PVL were retrospectively studied. Procedural characteristics, inhospital, and long-term clinical outcomes were assessed. Technical (successful deployment) and clinical (NYHA and/or hemolysis improvement) success were evaluated. RESULTS: In total, 39 patients treated for PVL in either the aortic (12 patients) or the mitral (27 patients) position were studied. Amplatzer Vascular Plug III was the most commonly used device among the 45 devices totally implanted. Postprocedurally, the rates of at least moderate PVL (87.5% preprocedurally vs 10.5% at discharge) and functional status (mean NYHA class 2.8 ± 0.7 on admission vs 1.5 ± 0.8 at follow-up) were statistically significantly improved. Total population technical success rate was 89.7%, being comparable between patients treated for mitral or aortic valve PVLs (92.6% vs 83.3%, respectively). Clinical success was achieved in 82.1% of patient cohort without statistical difference among those with isolated aortic or mitral PVL or among those with PVL closure an indication of heart failure or hemolysis. During a mean follow-up of 33.5 months, five patients died, including one periprocedural death. CONCLUSIONS: This multicenter recorded experience confirms that percutaneous PVL closure can be performed with high technical and clinical success rates and limited complications that lead to significant PVL reduction and functional status improvement.
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Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Cateterismo Cardíaco , Seguimentos , Próteses Valvulares Cardíacas/efeitos adversos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Falha de Prótese , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Two new biomimetic sensors for the detection of adiponectin (A) and leptin (L) through molecularly imprinted polymers (MIPs) onto gold working electrodes (GWEs) were fabricated. Based on electrochemical impedance spectroscopy (EIS) results and cyclic voltammetry (CV) characteristics recorded in the development stages of the fabricated sensors, the sensors were electrochemically optimized and used in an integrated microfluidic platform to detect adiponectin/leptin via conductance signals and non-imprinted electrodes were used as references. To overcome the limitation of the low response signals after template binding non-conductive polyphenol (PP) and poliscopoletin (PS) were used for templates formation. Under optimized experimental conditions the conductance and resistance signals were obtained in the linear range of 0-50 µg ml-1 for A and 1-32 ngâml-1 for L with low limits of detection (0.25 µg ml-1 for A and 0.110 ng ml-1 for L). The dedicated platform exhibited an excellent response with great selectivity and stability. Finally, the proposed biomimetic sensors were successfully applied to enable the determination of A and L in human patient's serum with very high accuracy when compared to enzyme-linked immunosorbent assay ELISA reference methods.
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Adiponectina/sangue , Materiais Biocompatíveis/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Leptina/sangue , Técnicas Biossensoriais/instrumentação , Impedância Elétrica , Técnicas Eletroquímicas/instrumentação , HumanosRESUMO
The environmental monitoring of Ni is targeted at a threshold limit value of 0.34 µM, as set by the World Health Organization. This sensitivity target can usually only be met by time-consuming and expensive laboratory measurements. There is a need for inexpensive, field-applicable methods, even if they are only used for signaling the necessity of a more accurate laboratory investigation. In this work, bioengineered, protein-based sensing layers were developed for Ni detection in water. Two bacterial Ni-binding flagellin variants were fabricated using genetic engineering, and their applicability as Ni-sensitive biochip coatings was tested. Nanotubes of mutant flagellins were built by in vitro polymerization. A large surface density of the nanotubes on the sensor surface was achieved by covalent immobilization chemistry based on a dithiobis(succimidyl propionate) cross-linking method. The formation and density of the sensing layer was monitored and verified by spectroscopic ellipsometry and atomic force microscopy. Cyclic voltammetry (CV) measurements revealed a Ni sensitivity below 1 µM. It was also shown that, even after two months of storage, the used sensors can be regenerated and reused by rinsing in a 10 mM solution of ethylenediaminetetraacetic acid at room temperature.
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Ouro , Nanotubos , Engenharia Biomédica , Microscopia de Força Atômica , ÁguaRESUMO
Atherosclerosis of the internal carotid artery is an important cause of disabling ischemic stroke and therefore constitutes a major medical, social, and economic issue. Although advances in vascular imaging modalities during the last decades allow to risk stratify patients not solely on the degree of carotid artery stenosis but also based on 'high risk' features, there still remains a controversy over patient selection for carotid artery revascularization. Among other features of plaque vulnerability, there is an increasing body of evidence that inflammation is a key factor in the initiation, progression and destabilization of atherosclerotic plaques. Microwave radiometry (MWR) is a new imaging method that is based on the ability to detect noninvasively, with high accuracy, the relative changes of temperature in human tissues reflecting inflammatory activation. This review article aims to: (1) give an overview of current clinical experience with MWR in carotid arteries and (2) present its potential role for risk stratification.
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Doenças das Artérias Carótidas/diagnóstico , Micro-Ondas , Placa Aterosclerótica/diagnóstico , Doenças das Artérias Carótidas/patologia , Humanos , Inflamação/diagnóstico , Inflamação/patologia , Placa Aterosclerótica/patologia , Radiometria , TermografiaRESUMO
BACKGROUND: Patients treated with antithrombotic therapy that require abdominal surgical procedures have progressively increased over time. The management of antithrombotics during both the peri- and postoperative period is of crucial importance. METHODS: The goal of this review is to present current data concerning the management of antiplatelets in patients with coronary artery disease and of anticoagulants in patients with atrial fibrillation who had to undergo abdominal surgical operations. For this purpose, the incidence of major adverse cardiovascular events (MACE) and risk of antithrombotic use during surgical procedures, as well as the recommendations based on recent guidelines were reported. A thorough search of PubMed, Scopus and the Cochrane Databases was conducted to identify randomized controlled trials, observational studies, novel current reviews, as well as ESC and ACC/AHA guidelines on the subject. RESULTS: Antithrombotic use in daily clinical practice leads to two different pathways: reduction of thromboembolic risk, but a simultaneous increase of bleeding risk. This may cause a therapeutic dilemma during the perioperative period. Nevertheless, careless cessation of antithrombotics can increase MACE and thromboembolic events. However, maintenance of antithrombotic therapy may increase bleeding complications. Studies and current guidelines can help clinicians in making decisions for the treatment of patients that undergo abdominal surgical operations while on antithrombotic therapy. Aspirin should not be stopped perioperatively in the majority of surgical operations. Determining whether to discontinue the use of anticoagulants before surgery depends on the surgical procedure. In surgical operations with a low risk for bleeding, oral anticoagulants should not be discontinued. Bridging therapy should only be considered in patients with a high risk of thromboembolism. Finally, in patients with an intermediate risk for thromboembolism, management should be individualized according to patient's thrombotic and bleeding risk. CONCLUSION: Management of antithrombotics therapy during the perioperative period in patients undergoing abdominal surgery should follow a patient-centered approach according to a patient's medical history and thrombotic risk weighted for bleeding risk.