Smart and Multifunctional Materials Based on Electroactive Poly(vinylidene fluoride): Recent Advances and Opportunities in Sensors, Actuators, Energy, Environmental, and Biomedical Applications.

From scientific and technological points of view, poly(vinylidene fluoride), PVDF, is one of the most exciting polymers due to its overall physicochemical characteristics. This polymer can crystalize into five crystalline phases and can be processed in the form of films, fibers, membranes, and specific microstructures, being the physical properties controllable over a wide range through appropriate chemical modifications. Moreover, PVDF-based materials are characterized by excellent chemical, mechanical, thermal, and radiation resistance, and for their outstanding electroactive properties, including high dielectric, piezoelectric, pyroelectric, and ferroelectric response, being the best among polymer systems and thus noteworthy for an increasing number of technologies. This review summarizes and critically discusses the latest advances in PVDF and its copolymers, composites, and blends, including their main characteristics and processability, together with their tailorability and implementation in areas including sensors, actuators, energy harvesting and storage devices, environmental membranes, microfluidic, tissue engineering, and antimicrobial applications. The main conclusions, challenges and future trends concerning materials and application areas are also presented.

Endoscopic sleeve gastroplasty: early results of a minimally invasive procedure in patients with obesity.

OBJECTIVES: We aimed to analyze the efficacy and safety of endoscopic sleeve gastroplasty at 3 months as well as to determine factors influencing post-procedural weight loss. METHODS: Seventy-three patients with obesity classes I, II and III (BMI 31.1-46.6 kg/m2) underwent ESG between September 2021 and April 2022 at a tertiary care hospital using Overstitch (Apollo Endosurgery, Austin, TX). ESG's efficacy and safety was evaluated at 1 and 3 months post-procedure with regard to excess weight loss (EWL) and total weight loss (TWL). Categorical variables were expressed as percentages and compared with chi-square test while continuous variables were expressed as mean ± standard deviation and compared with paired t test and analysis of variance (ANOVA) as applicable. Pearson's correlation was used to determine association between factors at baseline and weight loss. RESULTS: Mean age was 49.2 ± 9.7 years with 61 (83.6%) patients being female. Mean initial weight was 105.7 ± 15.7 kg, and mean BMI was 38.6 ± 3.5 kg/m2. Median hospitalization was 2.0 ± 1.8 days with 62 (84.9%) patients discharged after 24 h. One patient had accidental suturing of the stomach to the abdominal wall and diaphragm which was managed laparoscopically. Mean %EWL was 25.4 ± 7.1 and 36.3 ± 11.4, and %TBWL was 11.2 ± 2.6 and 15.8 ± 4.2 at 1 and 3 months, respectively. Significant excess weight loss at 3 months was only observed in patients with BMI < 40 kg/m2 (p = 0.001). CONCLUSIONS: ESG is safe and effective to manage obesity. Significant weight loss at 3 months was only observed in patients with obesity class I and class II.

Magnetic Bioreactor for Magneto-, Mechano- and Electroactive Tissue Engineering Strategies.

Biomimetic bioreactor systems are increasingly being developed for tissue engineering applications, due to their ability to recreate the native cell/tissue microenvironment. Regarding bone-related diseases and considering the piezoelectric nature of bone, piezoelectric scaffolds electromechanically stimulated by a bioreactor, providing the stimuli to the cells, allows a biomimetic approach and thus, mimicking the required microenvironment for effective growth and differentiation of bone cells. In this work, a bioreactor has been designed and built allowing to magnetically stimulate magnetoelectric scaffolds and therefore provide mechanical and electrical stimuli to the cells through magnetomechanical or magnetoelectrical effects, depending on the piezoelectric nature of the scaffold. While mechanical bioreactors need direct application of the stimuli on the scaffolds, the herein proposed magnetic bioreactors allow for a remote stimulation without direct contact with the material. Thus, the stimuli application (23 mT at a frequency of 0.3 Hz) to cells seeded on the magnetoelectric, leads to an increase in cell viability of almost 30% with respect to cell culture under static conditions. This could be valuable to mimic what occurs in the human body and for application in immobilized patients. Thus, special emphasis has been placed on the control, design and modeling parameters governing the bioreactor as well as its functional mechanism.

Marked Object Recognition Multitouch Screen Printed Touchpad for Interactive Applications.

The market for interactive platforms is rapidly growing, and touchscreens have been incorporated in an increasing number of devices. Thus, the area of smart objects and devices is strongly increasing by adding interactive touch and multimedia content, leading to new uses and capabilities. In this work, a flexible screen printed sensor matrix is fabricated based on silver ink in a polyethylene terephthalate (PET) substrate. Diamond shaped capacitive electrodes coupled with conventional capacitive reading electronics enables fabrication of a highly functional capacitive touchpad, and also allows for the identification of marked objects. For the latter, the capacitive signatures are identified by intersecting points and distances between them. Thus, this work demonstrates the applicability of a low cost method using royalty-free geometries and technologies for the development of flexible multitouch touchpads for the implementation of interactive and object recognition applications.

Improving Definition of Screen-Printed Functional Materials for Sensing Application.

Screen printing is one of the most used techniques for developing printed electronics. It stands out for its simplicity, scalability, and effectivity. Specifically, the manufacturing of hybrid integrated circuits has promoted the development of the technique, and the photovoltaic industry has enhanced the printing process by developing high-performance metallization pastes and high-end screens. In recent years, fine lines of 50 µm or smaller are about to be adopted in mass production, and screen printing has to compete with digital printing techniques such as inkjet printing, which can reach narrower lines. In this sense, this work is focused on testing the printing resolution of a high-performance stainless-steel screen with commercial conductive inks and functional lab-made inks based on reduced graphene oxide using an interdigitated structure. We achieved electrically conductive functional patterns with a minimum printing resolution of 40 µm for all inks.

Piezoelectric and Magnetically Responsive Biodegradable Composites with Tailored Porous Morphology for Biotechnological Applications.

The biomedical area in the scope of tissue regeneration pursues the development of advanced materials that can target biomimetic approaches and, ideally, have an active role in the environment they are placed in. This active role can be related to or driven by morphological, mechanical, electrical, or magnetic stimuli, among others. This work reports on the development of active biomaterials based on poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid), PHBV, a piezoelectric and biodegradable polymer, for tissue regeneration application by tailoring its morphology and functional response. PHBV films with different porosities were obtained using the solvent casting method, resorting to high-boiling-point solvents, as N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO), and the combination of chloroform (CF) and DMF for polymer dissolution. Furthermore, magnetoelectric biomaterials were obtained through the combination of the piezoelectric PHBV with magnetostrictive iron oxide (Fe3O4) nanoparticles. Independently of the morphology or filler content, all biomaterials proved to be suitable for biomedical applications.

Validation of an Artificial Intelligence Algorithm for Diagnostic Prediction of Coronary Disease: Comparison with a Traditional Statistical Model. / Validação de um Algoritmo de Inteligência Artificial para a Predição Diagnóstica de Doença Coronariana: Comparação com um Modelo Estatístico Tradicional.

BACKGROUND: Multivariate prognostic analysis has been traditionally performed by regression models. However, many algorithms capable of translating an infinity of patterns into probabilities have emerged. The comparative accuracy of artificial intelligence and traditional statistical models has not been established in the medical field. OBJECTIVE: To test the artificial intelligence as an accurate algorithm for predicting coronary disease in the scenario of acute chest pain and evaluate whether its performance is superior to traditional statistical model. METHODS: A consecutive sample of 962 patients admitted with chest pain was analyzed. Two probabilistic models of coronary disease were built using the first two-thirds of patients: a machine learning algorithm and a traditional logistic model. The performance of these two predictive strategies were evaluated in the remaining third of patients. The final logistic regression model had significant variables only, at the 5% significance level. RESULTS: The training sample had an average age of 59 ± 15 years, 58% males, and a 52% prevalence of coronary disease. The logistic model was composed of nine independent predictors. The machine learning algorithm was composed of all candidates for predictors. In the test sample, the area under the ROC curve for prediction of coronary disease was 0.81 (95% CI = 0.77 - 0.86) for the machine learning algorithm, similar to that obtained in logistic model (0.82; 95% CI = 0.77 - 0.87), p = 0.68. CONCLUSION: The present study suggests that an accurate machine learning prediction tool did not prove to be superior to the statistical model of logistic regression.

FUNDAMENTO: A análise prognóstica multivariada tem sido realizada tradicionalmente por modelos de regressão. No entanto, muitos algoritmos surgiram, capazes de traduzir uma infinidade de padrões em probabilidades. A acurácia dos modelos de inteligência artificial em comparação à de modelos estatísticos tradicionais não foi estabelecida na área médica. OBJETIVO: Testar a inteligência artificial como um algoritmo preciso na predição de doença coronariana no cenário de dor torácica aguda, e avaliar se seu desempenho é superior a do modelo estatístico tradicional. MÉTODOS: Foi analisada uma amostra consecutiva de 962 pacientes admitidos com dor torácica. Dois modelos probabilísticos de doença coronariana foram construídos com os primeiros 2/3 dos pacientes: um algoritmo machine learning e um modelo logístico tradicional. O desempenho dessas duas estratégias preditivas foi avaliado no último terço de pacientes. O modelo final de regressão logística foi construído somente com variáveis significativas a um nível de significância de 5%. RESULTADOS: A amostra de treinamento tinha idade média de 59 ± 15 anos, 58% do sexo masculino, e uma prevalência de doença coronariana de 52%. O modelo logístico foi composto de nove preditores independentes. O algoritmo machine learning foi composto por todos os candidatos a preditores. Na amostra teste, a área sob a curva ROC para predição de doença coronariana foi de 0,81 (IC95% = 0,77 ­ 0,86) para o algoritmo machine learning, similar à obtida no modelo logístico (0,82; IC95% = 0,77 ­ 0,87), p = 0,68. CONCLUSÃO: O presente estudo sugere que um modelo machine learning acurado não garante superioridade à um modelo estatístico tradicional.

Does Advanced Age Reduce the Typicality of Clinical Presentation in Patients with Acute Chest Pain Related to Coronary Artery Disease? / Idade Avançada Reduz a Tipicidade da Apresentação Clínica em Pacientes Com Dor Torácica Aguda Relacionada a Doença Coronária Obstrutiva?

BACKGROUND: According to traditional diagnosis thinking, very elderly individuals are more predisposed to develop atypical symptoms in acute coronary syndromes. OBJECTIVE: To test the hypothesis that very elderly individuals are more predisposed to atypical chest pain manifestations due to obstructive coronary artery disease (CAD). METHODS: The Registry of Thoracic Pain includes patients admitted with acute chest pain. Firstly, the typicality index of this clinical manifestation was constructed: the sum of 12 symptom characteristics (8 typical and 4 atypical symptoms). In the subgroup of patients with coronary etiology, the typicality index was compared between octogenarian and non-octogenarian individuals. Statistical significance was defined by p<0.05. RESULTS: 958 patients were included in the registry, and 486 (51%) had a supposedly coronary etiology. In this group, 59 (12%) octogenarians (age 84±3.5, 50% men) were compared to 427 patients aged <80 (60±12 years, 71% men). The typicality index in octogenarians was 3.42±1.92, which is similar to that of non-octogenarians (3.44±1.74; p=0.92 in univariate analysis and p=0.80 after adjustment for sex by analysis of variance - ANOVA). There was also no statistically significant difference when the sample was divided into median age (62 years; 3.41±1.77 vs. 3.49 ± 1.77; p=0.61). There was no statistically significant linear association between age and typicality index (r=- 0.05; p=0.24). Logistic regression analysis for prediction of CAD in the general sample of 958 patients showed no interaction of typicality index with numeric age (p=0.94), octogenarians (p=0.22) or age above median (p=0.74). CONCLUSION: In patients with acute chest pain of coronary etiology, advanced age does not influence the typical clinical presentation.

FUNDAMENTO: De acordo com o pensamento diagnóstico tradicional, indivíduos muito idosos estão mais predispostos a desenvolver sintomas atípicos em síndromes coronarianas agudas. OBJETIVO: Testar a hipótese de que indivíduos muito idosos estão mais predispostos a manifestações de dor torácica atípica devido à doença arterial coronariana obstrutiva (DAC). MÉTODOS: O Registro de dor torácica inclui pacientes internados com dor torácica aguda. Primeiramente, foi construído o índice de tipicidade dessa manifestação clínica: a soma de 12 características de sintomas (8 sintomas típicos e 4 sintomas atípicos). No subgrupo de pacientes com etiologia coronariana, o índice de tipicidade foi comparado entre octogenários e não octogenários. A significância estatística foi definida por p<0,05. RESULTADOS: 958 pacientes foram incluídos no registro, sendo que 486 (51%) tinham etiologia supostamente coronariana. Nesse grupo, 59 (12%) octogenários (idade 84±3,5; 50% homens) foram comparados a 427 pacientes com idade <80 (60±12 anos; 71% homens). O índice de tipicidade em octogenários foi 3,42±1,92, que é semelhante ao de não octogenários (3,44±1,74; p=0,092 na análise univariada e p=0,80 após ajuste para sexo pela análise de variância ­ ANOVA). Também não houve diferença estatisticamente significativa quando a amostra foi dividida em idade mediana (62 anos; 3,41±1,77 vs. 3,49 ± 1,77; p=0,61). Não houve associação linear estatisticamente significativa entre idade e índice de tipicidade (r=- 0,05; p=0,24). A análise de regressão logística para predição de DAC na amostra geral de 958 pacientes não mostrou interação do índice de tipicidade com a idade numérica (p=0,94), octogenários (p=0,22) ou idade acima da mediana (p=0,74). CONCLUSÃO: Em pacientes com dor torácica aguda de etiologia coronariana, a idade avançada não influencia o quadro clínico típico.

Triboelectric Energy Harvesting Response of Different Polymer-Based Materials.

Energy harvesting systems for low-power devices are increasingly being a requirement within the context of the Internet of Things and, in particular, for self-powered sensors in remote or inaccessible locations. Triboelectric nanogenerators are a suitable approach for harvesting environmental mechanical energy otherwise wasted in nature. This work reports on the evaluation of the output power of different polymer and polymer composites, by using the triboelectric contact-separation systems (10 N of force followed by 5 cm of separation per cycle). Different materials were used as positive (Mica, polyamide (PA66) and styrene/ethylene-butadiene/styrene (SEBS)) and negative (polyvinylidene fluoride (PVDF), polyurethane (PU), polypropylene (PP) and Kapton) charge materials. The obtained output power ranges from 0.2 to 5.9 mW, depending on the pair of materials, for an active area of 46.4 cm2. The highest response was obtained for Mica with PVDF composites with 30 wt.% of barium titanate (BT) and PA66 with PU pairs. A simple application has been developed based on vertical contact-separation mode, able to power up light emission diodes (LEDs) with around 30 cycles to charge a capacitor. Further, the capacitor can be charged in one triboelectric cycle if an area of 0.14 m2 is used.

Magnetic Proximity Sensor Based on Magnetoelectric Composites and Printed Coils.

Magnetic sensors are mandatory in a broad range of applications nowadays, being the increasing interest on such sensors mainly driven by the growing demand of materials required by Industry 4.0 and the Internet of Things concept. Optimized power consumption, reliability, flexibility, versatility, lightweight and low-temperature fabrication are some of the technological requirements in which the scientific community is focusing efforts. Aiming to positively respond to those challenges, this work reports magnetic proximity sensors based on magnetoelectric (ME) polyvinylidene fluoride (PVDF)/Metglas composites and an excitation-printed coil. The proposed magnetic proximity sensor shows a maximum resonant ME coefficient (α) of 50.2 Vcm-1 Oe-1, an AC linear response (R2 = 0.997) and a maximum voltage output of 362 mV, which suggests suitability for proximity-sensing applications in the areas of aerospace, automotive, positioning, machine safety, recreation and advertising panels, among others.

Magnetically Activated Electroactive Microenvironments for Skeletal Muscle Tissue Regeneration.

This work reports on magnetoelectric biomaterials suitable for effective proliferation and differentiation of myoblast in a biomimetic microenvironment providing the electromechanical stimuli associated with this tissue in the human body. Magnetoelectric films are obtained by solvent casting through the combination of a piezoelectric polymer, poly(vinylidene fluoride-trifluoro-ethylene), and magnetostrictive particles (CoFe2O4). The nonpoled and poled (with negative and positive surface charge) magnetoelectric composites are used to investigate their influence on C2C12 myoblast adhesion, proliferation, and differentiation. It is demonstrated that the proliferation and differentiation of the cells are enhanced by the application of mechanical and/or electrical stimulation, with higher values of maturation index under mechanoelectrical stimuli. These results show that magnetoelectric cell stimulation is a full potential approach for skeletal muscle tissue engineering applications.

Prognostic Contrast between Anatomical and Clinical Models Regarding Fatal and Non-Fatal Outcomes in Acute Coronary Syndromes. / Competência Prognóstica Distinta entre Modelo Clínico e Anatômico em Síndromes Coronarianas Agudas: Comparação por Tipo de Desfecho.

BACKGROUND: Recurrent ischemic events are mediated by atherosclerotic plaque instability, whereas death after an ischemic event results from gravity of insult and ability of the organism to adapt. The distinct nature of those types of events may respond for different prediction properties of clinical and anatomical information regarding type of outcome. OBJECTIVE: To identify prognostic properties of clinical and anatomical data in respect of fatal and non-fatal outcomes of patients hospitalized with acute coronary syndromes (ACS). METHODS: Patients consecutively admitted with ACS who underwent coronary angiography were recruited. The SYNTAX score was utilized as an anatomic model and the GRACE score as a clinical model. The predictive capacity of those scores was separately evaluated for prediction of non-fatal ischemic outcomes (infarction and refractory angina) and cardiovascular death during hospitalization. It was considered as significant a p-value <0,05. RESULTS: EAmong 365 people, cardiovascular death was observed in 4,4% and incidence of non-fatal ischemic outcomes in 11%. For cardiovascular death, SYNTAX and GRACE score presented similar C-statistic of 0,80 (95% IC: 0,70 - 0,92) and 0,89 (95% IC 0,81 - 0,96), respectively - p = 0,19. As for non-fatal ischemic outcomes, the SYNTAX score presented a moderate predictive value (C-statistic = 0,64; 95%IC 0,55 - 0,73), whereas the GRACE score did not presented association with this type of outcome (C-statistic = 0,50; 95%IC 0,40-0,61) - p = 0,027. CONCLUSION: Clinical and anatomic models similarly predict cardiovascular death in ACS. However, recurrence of coronary instability is better predicted by anatomic variables than clinical data. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0).

FUNDAMENTO: Eventos isquêmicos recorrentes decorrem de instabilidade de placa aterosclerótica, enquanto morte após um evento isquêmico decorre da gravidade do insulto. A natureza diversa desses tipos de eventos pode fazer com que dados clínicos e anatômicos tenham diferentes capacidades prognósticas a depender do tipo de desfecho. OBJETIVO: Identificar as predileções prognósticas de dados clínicos e dados anatômicos em relação a desfechos coronários fatais e não fatais durante hospitalização de pacientes com síndromes coronarianas agudas (SCA). MÉTODOS: Pacientes consecutivamente admitidos por SCA que realizaram coronariografia foram recrutados. O escore SYNTAX foi utilizado como modelo anatômico e o escore GRACE como modelo clínico. A capacidade preditora desses escores foi comparada quando à predição de desfechos isquêmicos não fatais (infarto ou angina refratária) e de morte cardiovascular durante hospitalização. Significância estatística foi definida por p < 0,05. RESULTADOS: Entre 365 indivíduos, 4,4% foi a incidência de óbito hospitalar e 11% de desfechos isquêmicos não fatais. Para morte cardiovascular, ambos os escores ­ SYNTAX e GRACE ­ apresentaram capacidade discriminatória, com estatísticas-C similares: 0,80 (95%IC: 0,70­0,92) e 0,89 (95%IC 0,81­0,96), respectivamente ­ p=0,19. Quantos aos desfechos isquêmicos não fatais, o escore SYNTAX apresentou valor preditor (estatística-C = 0,64; 95%IC 0,55­0,73), porém o escore GRACE não mostrou associação com esse tipo de desfecho (estatística-C = 0,50; 95%IC: 0,40­0,61) ­ p=0,027. CONCLUSÃO: Os modelos clínico e anatômico predizem satisfatoriamente morte cardiovascular em SCA, enquanto a recorrência de instabilidade coronária é melhor prevista por características anatômicas do que por dados clínicos. (Arq Bras Cardiol. 2020; 115(2):219-225).

Prognostic Value of NT-proBNP versus Killip Classification in Patients with Acute Coronary Syndromes.

BACKGROUND: Plasma levels of brain natriuretic peptides have better diagnostic accuracy compared to clinical-radiologic judgment for acute heart failure. In acute coronary syndromes (ACS), the prognostic value of acute heart failure is incorporated into predictive models through Killip classification. It is not established whether NT-proBNP could increment prognostic prediction. OBJECTIVE: To evaluate whether NT-proBNP, as a measure of left ventricular dysfunction, improves the in-hospital prognostic value of the GRACE score in ACS. METHODS: Patients admitted due to acute chest pain, with electrocardiogram and/or troponin criteria for ACS were included in the study. The plasma level of NT-proBNP was measured at hospital admission and the primary endpoint was defined as cardiovascular death during hospitalization. P-value < 0.05 was considered as significant. RESULTS: Among 352 patients studied, cardiovascular mortality was 4.8%. The predictive value of NT-proBNP for cardiovascular death was shown by a C-statistic of 0.78 (95% CI = 0.65-0.90). After adjustment for the GRACE model subtracted by Killip variable, NT-proBNP remained independently associated with cardiovascular death (p = 0.015). However, discrimination by the GRACE-BNP logistic model (C-statistics = 0.83; 95%CI = 0.69-0.97) was not superior to the traditional GRACE Score with Killip (C-statistic = 0.82; 95%CI = 0.68-0.97). The GRACE-BNP model did not provide improvement in the classification of patients to high risk by the GRACE Score (net reclassification index = - 0.15; p = 0.14). CONCLUSION: Despite the statistical association with cardiovascular death, there was no evidence that NT-proBNP increments the prognostic value of GRACE score in ACS.

Survival after out-of-hospital cardiac arrest in Europe - Results of the EuReCa TWO study.

BACKGROUND: The epidemiology and outcome after out-of-hospital cardiac arrest (OHCA) varies across Europe. Following on from EuReCa ONE, the aim of this study was to further explore the incidence of and outcomes from OHCA in Europe and to improve understanding of the role of the bystander. METHODS: This prospective, multicentre study involved the collection of registry-based data over a three-month period (1st October 2017 to 31st December 2017). The core study dataset complied with the Utstein-style. Primary outcomes were return of spontaneous circulation (ROSC) and survival to hospital admission. Secondary outcome was survival to hospital discharge. RESULTS: All 28 countries provided data, covering a total population of 178,879,118. A total of 37,054 OHCA were confirmed, with CPR being started in 25,171 cases. The bystander cardiopulmonary resuscitation (CPR) rate ranged from 13% to 82% between countries (average: 58%). In one third of cases (33%) ROSC was achieved and 8% of patients were discharged from hospital alive. Survival to hospital discharge was higher in patients when a bystander performed CPR with ventilations, compared to compression-only CPR (14% vs. 8% respectively). CONCLUSION: In addition to increasing our understanding of the role of bystander CPR within Europe, EuReCa TWO has confirmed large variation in OHCA incidence, characteristics and outcome, and highlighted the extent to which OHCA is a public health burden across Europe. Unexplained variation remains and the EuReCa network has a continuing role to play in improving the quality management of resuscitation.

Bioinspired Three-Dimensional Magnetoactive Scaffolds for Bone Tissue Engineering.

Bone tissue repair strategies are gaining increasing relevance due to the growing incidence of bone disorders worldwide. Biochemical stimulation is the most commonly used strategy for cell regeneration, while the application of physical cues, including magnetic, mechanical, or electrical fields, is a promising, however, scarcely investigated field. This work reports on novel magnetoactive three-dimensional (3D) porous scaffolds suitable for effective proliferation of osteoblasts in a biomimetic microenvironment. This physically active microenvironment is developed through the bone-mimicking structure of the scaffold combined with the physical stimuli provided by a magnetic custom-made bioreactor on a magnetoresponsive scaffold. Scaffolds are obtained through the development of nanocomposites comprised of a piezoelectric polymer, poly(vinylidene fluoride) (PVDF), and magnetostrictive particles of CoFe2O4, using a solvent casting method guided by the overlapping of nylon template structures with three different fiber diameter sizes (60, 80, and 120 µm), thus generating 3D scaffolds with different pore sizes. The magnetoactive composites show a structure very similar to trabecular bone with pore sizes that range from 5 to 20 µm, owing to the inherent process of crystallization of PVDF with the nanoparticles (NPs), interconnected with bigger pores, formed after removing the nylon templates. It is found that the materials crystallize in the electroactive ß-phase of PVDF and promote the proliferation of preosteoblasts through the application of magnetic stimuli. This phenomenon is attributed to both local magnetomechanical and magnetoelectric response of the scaffolds, which induce a proper cellular mechano- and electro-transduction process.

Behavioral Influence of Known Prognostic Markers on the Cardiologist's Decision following Acute Coronary Syndrome: the GRACE Score Paradox.

BACKGROUND: Behavioral scientists consistently point out that knowledge does not influence decisions as expected. GRACE Score is a well validated risk model for predicting death of patients with acute coronary syndromes (ACS). However, whether prognostic assessment by this Score modulates medical decision is not known. OBJECTIVE: To test the hypothesis that the use of a validated risk score rationalizes the choice of invasive strategies for higher risk patients with non-ST-elevation ACS. METHODS: ACS patients were consecutively included in this prospective registry. GRACE Score was routinely used by cardiologists as the prognostic risk model. An invasive strategy was defined as an immediate decision of the coronary angiography, which in the selective strategy was only indicated in case of positive non-invasive test or unstable course. Firstly, we evaluated the association between GRACE and invasiviness; secondly, in order to find out the actual determinants of the invasive strategy, we built a propensity model for invasive decision. For this analysis, a p-value < 0.05 was considered as significant. RESULTS: In a sample of 570 patients, an invasive strategy was adopted for 394 (69%). GRACE Score was 118 ± 38 for the invasive group, similar to 116 ± 38 for the selective group (p = 0.64). A propensity score for the invasive strategy was derived from logistic regression: positive troponin and ST-deviation (positive associations) and hemoglobin (negative association). This score predicted an invasive strategy with c-statistics of 0.68 (95%CI: 0.63-0.73), opposed to GRACE Score (AUC 0.51; 95%CI: 0.47-0.57). CONCLUSION: The dissociation between GRACE Score and invasive decision in ACS suggests that the knowledge of prognostic probabilities might not determine medical decision.

Indirect X-ray Detectors Based on Inkjet-Printed Photodetectors with a Screen-Printed Scintillator Layer.

Organic photodetectors (PDs) based on printing technologies will allow to expand the current field of PD applications toward large-area and flexible applications in areas such as medical imaging, security, and quality control, among others. Inkjet printing is a powerful digital tool for the deposition of smart and functional materials on various substrates, allowing the development of electronic devices such as PDs on various substrates. In this work, inkjet-printed PD arrays, based on the organic thin-film transistor architecture, have been developed and applied for the indirect detection of X-ray radiation using a scintillator ink as an X-ray absorber. The >90% increase of the photocurrent of the PDs under X-ray radiation, from about 53 nA without the scintillator film to about 102 nA with the scintillator located on top of the PD, proves the suitability of the developed printed device for X-ray detection applications.

Inconsistency prevents the valuable synergism of explanatory and pragmatic trails.

OBJECTIVE: To assess review articles on pragmatic trials in order to describe how authors define the aim of this type of study, how comprehensive methodological topics are covered, and which topics are most valued by authors. METHODS: Review articles were selected from Medline Database, based on the expression "pragmatic trial" in the titles. Five trained medical students evaluated the articles, based on a list of 15 self-explanatory methodological topics. Each article was evaluated regarding topics covered. Baseline statements on the aim of pragmatic trials were derived. RESULTS: Among 22 articles identified, there was general agreement that the aim of a pragmatic trial is to evaluate if the intervention works under real-world conditions. The mean number of methodological topics addressed by each article was 7.6 ± 3.1. Only one article covered all 15 topics, three articles (14%) responded to at least 75% of topics and 13 articles (59%) mentioned at least 50% of the topics. The relative frequency each of the 15 topics was cited by articles had a mean of 50% ± 25%. No topic was addressed by all articles, only three (20%) were addressed by more than 75% of articles. CONCLUSIONS: There is agreement on the different aims of explanatory and pragmatic trials. But there is a large variation on methodological topics used to define a pragmatic trial, which led to inconsistency in defining the typical methodology of a pragmatic trial.

Prognostic Accuracy of the GRACE Score in Octogenarians and Nonagenarians with Acute Coronary Syndromes.

BACKGROUND: The GRACE Score was derived and validated from a cohort in which octogenarians and nonagenarians were poorly represented. OBJECTIVE: To test the accuracy of the GRACE score in predicting in-hospital mortality of very elderly individuals with acute coronary syndromes (ACS). METHODS: Prospective observational study conducted in the intensive coronary care unit of a tertiary center from September 2011 to August 2016. Patients consecutively admitted due to ACS were selected, and the very elderly group was defined by age ≥ 80 years. The GRACE Score was based on admission data and its accuracy was tested regarding prediction of in-hospital death. Statistical significance was defined by p value < 0,05. RESULTS: A total of 994 individuals was studied, 57% male, 77% with non-ST elevation myocardial infarction and 173 (17%) very elderly patients. The mean age of the sample was 65 ± 13 years, and the mean age of very elderly patients subgroup was 85 ± 3.7 years. The C-statistics of the GRACE Score in very elderly patients was 0.86 (95% CI = 0.78 - 0.93), with no difference when compared to the value for younger individuals 0.83 (95% CI = 0.75 - 0.91), with p = 0.69. The calibration of the score in very elderly patients was described by χ2 test of Hosmer-Lemeshow = 2.2 (p = 0.98), while the remaining patients presented χ2 = 9.0 (p = 0.35). Logistic regression analysis for death prediction did not show interaction between GRACE Score and variable of very elderly patients (p = 0.25). CONCLUSION: The GRACE Score in very elderly patients is accurate in predicting in-hospital ACS mortality, similarly to younger patients.

Real-Time Energy Management System for Microgrids

Abstract: Microgrids (MD) is a new technology to improve efficiency, resilience, and reliability in the electricity sector. MD are most likely to have a clean energy generation, but the increase of microgrids with this kind of generation brings new challenges for energy management (EMS), especially concerning load uncertainties and variation of energy generation. In this context, this study has the main objective to propose a method of how to attend this matter, verifying the difference between the day before and real-time. The EMS proposed analyses the MD in real-time, calculating the deviation between dispatched and what was predicted to happen in the operation point in a three-dimensional analysis approach, considering renewable energy generation, battery State of Charge (SOC) and load curve. The system categorized the deviation in three possible quantities (small, medium, or high) and it acts accordingly. For the Next Operation Point predictor are used an artificial neural network (ANN) methodology. For the Decision Support System, it's used a fuzzy logic system to adjust the next operation point, and it uses a mixed-integer linear programming (MILP) approach when the deviation is too high, and the dispatched operation is unfeasible. Simulations with real data and information of a pilot project of MD are carried out to test and validate the proposed method. Results show that the methodology used to attend the matters of uncertainties and variation of energy generation. A reduction of operational cost is observed in the simulations.