Enhancing Intramolecular Ferromagnetic Coupling in Tetrathiafulvalene-Nitronyl Nitroxide-Based Compounds through Spin Polarization Mechanism.

Spin-polarized donor radicals based on tetrathiafulvalene (TTF) derivatives and nitronyl nitroxide (NN) radicals in which one-electron oxidation involves the HOMO instead of the SOMO are well known for exhibiting magnetoresistance. In particular, BTBN consists of one dibromo-TTF and one NN radical, which are linked by a phenyl coupler group. One of the key factors driving magnetoresistance is the presence of intramolecular ferromagnetic (FM) coupling between the oxidized π-donor (TTF+⋅, D unit) and NN (R unit). Here, a theoretical study is carried out to assess suitable candidates with enhanced FM coupling with respect BTBN, which is thus used as a reference. The study is conducted via in silico chemical modification of the substituents of the BTBN basic functional units (D and R radicals, C coupler) to benefit from the spin polarization mechanism to boost the intramolecular FM coupling, aiming to distort the BTBN radical arrangement within the molecular crystal as little as possible, in the event the material can be synthesized. NICSiso(1) and Wiberg's Bond Order are analyzed to further assist in identifying promising potential candidates, since the decrease in aromaticity is expected to enhance the diradical character and give rise to a larger magnetic coupling value. The most favorable diradical building block to replace the BTBN moiety results from using a hydroxyl-ethylene (-(H)C=C(OH)-) as a coupler preserving BTBN original radicals, namely, NN and TTF+⋅ units. This study aims at illustrating the feasibility of improving the intramolecular FM interaction between radical moieties, which is fully realized, as a first step towards the synthesis of new materials with (possibly) enhanced magnetoresistance properties.

Learning techniques that medical students use for long-term retention: A cross-sectional analysis.

BACKGROUND: Reviews and meta-analysis conclude that distributed practice and practice testing are deemed the most effective learning techniques among undergraduate students, while rereading, underlining, and summarisation are the most known and less effective ones. However, this evidence is gathered from short-term retention studies prior to 2014, and there are other techniques with promising effect (metacognition, retrieval, concept mapping, setting learning goals) that were not included. Also, there is little real-settings evidence regarding what works best for long-term retention in medical students. METHODS: A cross-sectional analysis was carried out in a sample of 155 of second and third-year students of the Degree in Medicine at Universidad de Navarra in September 2020. The aim was to evaluate the impact the use of different learning techniques had on academic performance of undergraduate medical students, assessing up to three months of retention. A subgroup analysis was performed based on learning approach, spacing of the learning sessions, and academic results. RESULTS: Rereading, highlighting, and summarisation were the most known and used techniques among medical students, with detrimental effects on academic outcomes. Metacognition was the most effective technique, but up to 92% of the students didn't know what it was. No single learning technique seemed to improve results in below-average students. CONCLUSIONS: University curricula should promote the use of more efficient techniques, particularly metacognition, to help students become lifelong learners. More studies are needed to confirm these findings. Below-average students remain a challenging population.

"What medical students with better academic results do: a cross-sectional analysis".

BACKGROUND: With university material doubling over time, medical students need to learn how to become successful life-long learners. Overall a Deep Approach (DA) to learning, and Self-Regulation (SR) skills are among the elements with a potential to accelerate learning, and Student Engagement (SE) has been associated with better university outcomes. However, specific recommendations concerning what students should do are lacking. The aim of this study was to identify above-average students' specific attitudes and strategies toward learning. METHODS: A cross-sectional analysis of the answers to the validated questionnaires Revised Study Process Questionnaire (R-SPQ-2F), SE, and Motivated Strategies for Learning Questionnaire (MSLQ) of 155 s and third-year students included in a prospective interventional study in the University of Navarre in September 2020 was performed. Students were stratified according to their standardized average mean in above-average (mean > 0) and below-average (mean ≤ 0). RESULTS: Overall, 67.1% of students scored higher in DA than in Surface Approach (SA) and had very high Intrinsic Value (IV, median 5.9). A higher proportion of above-average students had DA > SA score (72.7% vs 57.1%, p = 0.05), and showed higher scores in SR (median 4.9 vs 4.3, p = 0.007) compared to below-average, while the latter scored higher in SA (median 24.5 vs 23, p = 0.04), and surface motive (median 11 vs 9, p = 0.007). No differences were found in SE, and both groups had average scores in the cooperative dimension. Differences were rooted to hard work, interest over material and prioritizing understanding over rote-learning motives and aligned strategies. CONCLUSIONS: Curricula design and assessment should be aligned to promote DA and SR skills among learners. Furthermore, it is paramount that teachers help instill students with interest over material and encourage understanding and hard work, since are traits associated with better results. More studies concerning metacognition and other promising traits for becoming life-long learners and prepared professionals should be made.

The essential role of thoracic duct embolization in management of traumatic iatrogenic chylothorax.

This study aims to describe a case series of patients who underwent thoracic duct embolization (TDE) to treat traumatic iatrogenic chylothorax (TIC). Three patients were included: Case #1, a 49-year-old woman with follicular lymphoma developed a TIC following video-assisted thoracoscopic surgery to resect a solid right paravertebral mass and was treated with TDE using microcoils and N-butyl cyanoacrylate (NBCA) glue. Case #2, a 68-year-old man with cardiac amyloidosis developed a TIC following heart transplantation and was treated with TDE using microcoils and ethylene vinyl alcohol copolymer. Case#3: A 6-year-old patient with congenital heart disease developed a TIC following a Fontan procedure and was treated with TDE using NBCA glue. All lesions were identified during lymphangiography and TDE was successfully performed in all cases. TDE is a safe and valuable technique that provides minimally invasive treatment for TCI.

Este estudo objetiva descrever uma série de casos de pacientes submetidos a embolização do ducto torácico (EDT) para tratamento de quilotórax iatrogênico (QI). Três pacientes foram incluídos. Caso 1: um homem de 49 anos com linfoma folicular apresentou QI após ressecção de uma massa paravertebral por toracoscopia vídeo-assistida e foi submetido a EDT com micromolas e n-butil-cianoacrilato (NBCA). Caso 2: um homem de 68 anos com amiloidose cardíaca apresentou QI após ser submetido a transplante cardíaco e foi submetido a EDT com micromolas e copolímero de etileno e álcool vinílico. Caso 3: um paciente de 6 anos com malformação cardíaca congênita apresentou QI após cirurgia de Fontan e foi submetido a EDT com NBCA. Todas as lesões foram identificadas durante a linfangiografia, e a EDT foi realizada com sucesso. A EDT é uma técnica segura e valiosa, que pode oferecer um tratamento minimamente invasivo em casos de QI.

Twistable dipolar aryl rings as electric field actuated conformational molecular switches.

The ability to control the chemical conformation of a system via external stimuli is a promising route for developing molecular switches. For eventual deployment as viable sub-nanoscale components that are compatible with current electronic device technology, conformational switching should be controllable by a local electric field (i.e. E-field gateable) and accompanied by a rapid and significant change in conductivity. In organic chemical systems the degree of π-conjugation is linked to the degree of electronic delocalisation, and thus largely determines the conductivity. Here, by means of accurate first principles calculations, we study the prototypical biphenyl based molecular system in which the dihedral angle between the two rings determines the degree of conjugation. In order to make this an E-field gateable system we create a net dipole by asymmetrically functionalising one ring with: (i) electron withdrawing (F, Br and CN), (ii) electron donating (NH2), and (iii) mixed (NH2/NO2) substituents. In this way, the application of an E-field interacts with the dipolar system to influence the dihedral angle, thus controlling the conjugation. For all considered substituents we consider a range of E-fields, and in each case extract conformational energy profiles. Using this data we obtain the minimum E-field required to induce a barrierless switching event for each system. We further extract the estimated switching speeds, the conformational probabilities at finite temperatures, and the effect of applied E-field on electronic structure. Consideration of these data allow us to assess which factors are most important in the design of efficient gateable electrical molecular switches.

Electronic, Structural and Functional Versatility in Tetrathiafulvalene-Lanthanide Metal-Organic Frameworks.

Tetrathiafulvalene-lanthanide (TTF-Ln) metal-organic frameworks (MOFs) are an interesting class of multifunctional materials in which porosity can be combined with electronic properties such as electrical conductivity, redox activity, luminescence and magnetism. Herein a new family of isostructural TTF-Ln MOFs is reported, denoted as MUV-5(Ln) (Ln=Gd, Tb, Dy, Ho, Er), exhibiting semiconducting properties as a consequence of the short intermolecular S⋅⋅⋅S contacts established along the chain direction between partially oxidised TTF moieties. In addition, this family shows photoluminescence properties and single-molecule magnetic behaviour, finding near-infrared (NIR) photoluminescence in the Yb/Er derivative and slow relaxation of the magnetisation in the Dy and Er derivatives. As such properties are dependent on the electronic structure of the lanthanide ion, the immense structural, electronic and functional versatility of this class of materials is emphasised.

High prevalence and poor control of hypertension in five venezuelan populations: the VEMSOLS study.

The prevalence of hypertension in multiple regions of Venezuela is unknown. The objective of this study was to estimate the prevalence of hypertension in five populations from three regions. During 2006 to 2010, 1392 subjects aged 20 or older were selected by multistage stratified random sampling from all households in five municipalities from: Lara State (Western region), Merida State (Andean region), and Capital District (Capital region). Anthropometric measurements, blood pressure, and biochemical analysis were obtained from each participant. Mean age was 45.2 ± 0.4 years and 68% were females. The overall prevalence of hypertension was 31.3% (CI 95% 28.9 ­ 33.8), it was higher in men than women (38.1% [33.5 ­ 42.8] vs. 28.2% [25.4 ­ 31.2], respectively; p <0.001). The hypertensive participants were older, with higher body mass index (BMI), glucose, total cholesterol, LDL-c, and triglycerides; and lower values of HDL-c, than pre-hypertensive and normotensive participants (p < 0.05). In women, hypertension prevalence increased linearly for every decade of life and by category of BMI; whereas in men it increased until the fifth decade of life, and was similar in patients with overweight and obesity. The risk of hypertension increased with age, the presence of obesity, diabetes, overweight and family history of hypertension. Only 17.7% of the hypertensive subjects were both treated and controlled. In conclusion, about one third of the subjects evaluated had hypertension and about one fifth of them had their hypertension under control. In Venezuela, hypertension is a serious public health problem exacerbated by age and overweight.

[Psychological resistance to use insulin in type 2 diabetes mellitus patients from Venezuela]. / Resistencia psicológica al uso de insulina en pacientes con diabetes mellitus tipo 2 en una población venezolana.

The psychological resistance to use insulin (PIR) is a condition where the patient with type 2 diabetes mellitus (T2DM) refuses to use insulin. Our objective was to determine the frequency of PIR in a Venezuelan population and their beliefs regarding insulin and current medication. In several states of Venezuela, from January to March 2013, 254 patients with T2DM, over 18 years old and naive to insulin treatment were interviewed. We applied an interview to evaluate the disposition of the patients to use insulin if their doctor prescribes it and to determine their beliefs about insulin and their current medication. The patients were categorized in: not willing (PIR group), ambivalent and willing to use insulin. The beliefs about insulin and their current medication were grouped into positive or negative. The mean age was 56.2 years, with 7.1 years of duration of the T2DM; 58.6% were females. One third (32.7%) had PIR, 20.9% were ambivalent and 46.4% were willing to use insulin. PIR patients showed lower frequency of positive beliefs and more frequency of negative beliefs to insulin and to their current treatment (p < 0.0001). Negative beliefs to insulin increased 14 times the risk of PIR, and people without university studies had a four times increase in the risk of PIR compared to the willing group. In conclusion, a high frequency of PIR in patients with T2DM (32.7%) was found in Venezuela; they showed low frequency of positive beliefs and high frequency of negative beliefs about insulin use. It is necessary to improve T2DM patient education on this issue.

Wireless vital signs from a life-supporting medical device exposed to electromagnetic disturbance.

OBJECTIVES: To evaluate the level of agreement of simulated wired and Wi-Fi vital signs output from an intra-aortic balloon pump during exposure to electromagnetic interference from frequency overlapping ZigBee sensors. MATERIAL AND METHODS: A series of experiments with interference from single and multiple ZigBee sensors were benchmarked with wired and Wi-Fi output. Tests included single ZigBee sensor adjacent and co-channel interference, and multiple ZigBee interferences towards the Wi-Fi receiver and transmitter. RESULTS: Interference-free differences between wired and wireless aortic blood pressure and electrocardiogram were very small, verified by time domain and Bland - Altman plots. Bland - Altman plots comparing level of agreement in wired and wireless aortic blood pressure and ECG output during interference experiments showed a difference from 0.2 to 0.3 mmHg for blood pressure, and from 0.001 to 0.004 mV for electrocardiogram. CONCLUSIONS: Level of agreement in wired and wireless (Wi-Fi) arterial blood pressure and electrocardiogram during single or multiple sensor interference was high. No clinically relevant degradation of Wi-Fi transmission of aortic blood pressure or ECG signals was observed.

Case Report: The Challenge for Diagnosis of Myocarditis and Transplant Rejection After COVID Infection in a Heart-Transplanted Adolescent.

Patients who have undergone organ transplantation are immunosuppressed hosts, leaving them at a higher risk of infections. SARS-COV-2 has been shown to affect heart-transplanted patients. In this case report, we present the case of a 14-year-old heart transplant recipient who developed signs and symptoms of heart failure, along with fatigue, after a COVID-19 infection. An endomyocardial biopsy was performed to diagnose rejection and to evaluate whether this was myocarditis due to SARS-COV-2. The biopsy showed intense acute cellular rejection (3R) and antibody rejection PAMR1 H+ but was negative for the SARS-CoV-2 virus. The patient received organ rejection therapy with high-dose methylprednisolone and human immunoglobulin. After treatment, her heart function recovered, with biopsy investigations showing a lower level of cellular rejection (1R).

Controlling pairing of π-conjugated electrons in 2D covalent organic radical frameworks via in-plane strain.

Controlling the electronic states of molecules is a fundamental challenge for future sub-nanoscale device technologies. π-conjugated bi-radicals are very attractive systems in this respect as they possess two energetically close, but optically and magnetically distinct, electronic states: the open-shell antiferromagnetic/paramagnetic and the closed-shell quinoidal diamagnetic states. While it has been shown that it is possible to statically induce one electronic ground state or the other by chemical design, the external dynamical control of these states in a rapid and reproducible manner still awaits experimental realization. Here, via quantum chemical calculations, we demonstrate that in-plane uniaxial strain of 2D covalently linked arrays of radical units leads to smooth and reversible conformational changes at the molecular scale that, in turn, induce robust transitions between the two kinds of electronic distributions. Our results pave a general route towards the external control, and thus technological exploitation, of molecular-scale electronic states in organic 2D materials.

Coarctation of the aorta treated with the Advanta V12 large diameter stent: acute results.

OBJECTIVES: To report on the early results of treatment of coarctation of the aorta by dilation with a new polytetrafluoroethylene covered stent. BACKGROUND: Transcatheter dilation of aortic coarctation carries the risk of aneurysm or rupture. Covered stent implantation reduces this risk but requires a large delivery system. The Advanta V12 LD covered stent is premounted and requires a 9-11 Fr delivery system. METHODS: Covered stents on balloons of a diameter sufficient to anchor the stent in the coarctation were implanted using the smallest available delivery system. Secondary dilation with larger diameter balloons was performed until the pressure gradient was <20 mm Hg and the stent was opposed to the aortic wall. RESULTS: Twenty-five patients with aortic coarctation underwent stent implantation. Coarctation diameter increased from (6.3 + or - 3.5) mm to (14.4 + or - 2.3) mm (P < 0.0001). Peak pressure gradient decreased from (25.3 + or - 11.6) mm Hg to (2.5 + or - 3.0) mm Hg (P < 0.0001). The stent achieved the desired diameter in all cases. There were no complications. At short-term median follow-up of 4.9 months, all patients are alive and well with no evidence of recoarctation or aneurysm. CONCLUSIONS: These initial results show that the covered Advanta V12LD stent is safe and effective in the immediate treatment of coarctation of the aorta through a low profile delivery system of 8-11 Fr. Long term follow up is required.

Interaction modes between nanosized graphene flakes and liposomes: Adsorption, insertion and membrane fusion.

BACKGROUND: Understanding the effects of graphene-based nanomaterials on lipid membranes is critical to determine their environmental impact and their efficiency in the biomedical context. Graphene has been reported to favourably interact with biological and model lipid membranes. METHODS: We report on a systematic coarse-grained molecular dynamics study of the interaction modes of graphene nanometric flakes with POPC/cholesterol liposome membranes. We have simulated graphene layers with a variety of sizes and oxidation degrees, and we have analyzed the trajectories, the interaction modes, and the energetics of the observed phenomena. RESULTS: Three interaction modes are reported. Graphene can be transiently adsorbed onto the liposome membrane and/or inserted in its hydrophobic region. Inserted nanosheets prefer a perpendicular orientation, and tilt in order to maximize the contact with phospholipid tails while avoiding the contact with cholesterol molecules. When placed between two liposomes, graphene facilitates their fusion in a single vesicle. CONCLUSIONS: Graphene can be temporary adsorbed on the liposome before insertion. Bilayer curvature has an influence on the orientation of inserted graphene particles. Cholesterol molecules are depleted from the surrounding of graphene particles. Graphene layers may catalyse membrane fusion by bypassing the energy barrier required in stalk formation. GENERAL SIGNIFICANCE: Nanometric graphene layers can be adsorbed/inserted in lipid-based membranes in different manners and affect the cholesterol distribution in the membrane, implying important consequences on the structure and functionality of biological cell membranes, and on the bioaccumulation of graphene in living organisms. The graphene-mediated mechanism opens new possibilities for vesicle fusion in the experimental context.

The essential role of thoracic duct embolization in management of traumatic iatrogenic chylothorax / O papel fundamental da embolização do ducto torácico no manejo de quilotórax traumático iatrogênico

Abstract This study aims to describe a case series of patients who underwent thoracic duct embolization (TDE) to treat traumatic iatrogenic chylothorax (TIC). Three patients were included: Case #1, a 49-year-old woman with follicular lymphoma developed a TIC following video-assisted thoracoscopic surgery to resect a solid right paravertebral mass and was treated with TDE using microcoils and N-butyl cyanoacrylate (NBCA) glue. Case #2, a 68-year-old man with cardiac amyloidosis developed a TIC following heart transplantation and was treated with TDE using microcoils and ethylene vinyl alcohol copolymer. Case#3: A 6-year-old patient with congenital heart disease developed a TIC following a Fontan procedure and was treated with TDE using NBCA glue. All lesions were identified during lymphangiography and TDE was successfully performed in all cases. TDE is a safe and valuable technique that provides minimally invasive treatment for TCI.

Resumo Este estudo objetiva descrever uma série de casos de pacientes submetidos a embolização do ducto torácico (EDT) para tratamento de quilotórax iatrogênico (QI). Três pacientes foram incluídos. Caso 1: um homem de 49 anos com linfoma folicular apresentou QI após ressecção de uma massa paravertebral por toracoscopia vídeo-assistida e foi submetido a EDT com micromolas e n-butil-cianoacrilato (NBCA). Caso 2: um homem de 68 anos com amiloidose cardíaca apresentou QI após ser submetido a transplante cardíaco e foi submetido a EDT com micromolas e copolímero de etileno e álcool vinílico. Caso 3: um paciente de 6 anos com malformação cardíaca congênita apresentou QI após cirurgia de Fontan e foi submetido a EDT com NBCA. Todas as lesões foram identificadas durante a linfangiografia, e a EDT foi realizada com sucesso. A EDT é uma técnica segura e valiosa, que pode oferecer um tratamento minimamente invasivo em casos de QI.

Non-Hodgkin's lymphoma presenting as ulcerative colitis.

High-grade Non-Hodgkin's lymphomas are very aggressive type of malignancies. We report a high grade small B-cell (Burkitt's like) Non-Hodgkin's lymphoma that initially was considered and treated as ulcerative colitis without improvement or resolution of symptoms for nine months. The clinical presentation of 30 lb weight loss, diarrhea and dyspaurenia as complications of the developing and rapid growth of the mass were highly suggestive of malignancy. Acute lesions of ulcerative colitis begin at the anal verge and involve only the mucosa and submucosa. When induration of the perirectal areas develop a different pathology should be suspected.

Management of Dabigatran-Associated Bleeding with Two Doses of Idarucizumab Plus Hemodialysis.

Vitamin K antagonists have been a mainstay of treatment for patients requiring anticoagulation for atrial fibrillation, but direct oral anticoagulants, such as dabigatran, have become increasingly prescribed. Compared with warfarin, dabigatran has a significantly lower risk of life-threatening bleeding; however, bleeding events can still occur, supporting the need for effective reversal strategies. Idarucizumab was recently approved by the U.S. Food and Drug Administration to reverse the anticoagulant effects of dabigatran when life-threatening bleeding occurs or an urgent need for an invasive medical procedure exists. Before idarucizumab's approval, reversal strategies included hemodialysis, coagulation factor replacement, and, in the setting of acute ingestion, activated charcoal. We describe the case of a 58-year-old, obese woman with a history of atrial fibrillation who developed acute kidney injury while taking dabigatran 150 mg twice/day, resulting in coagulopathy. Despite receiving idarucizumab 5 g and hemodialysis, there was a rebound increase in prothrombin time (PT) and activated partial thromboplastin time (aPTT) values, prompting administration of an additional 5-g dose of idarucizumab and continued hemodialysis, with subsequent PT and aPTT values remaining within their appropriate ranges. To our knowledge, this is the first case report to describe the successful use of repeat dosing of idarucizumab with hemodialysis to reverse the anticoagulant effects of dabigatran. Although two doses of idarucizumab were given to our patient, this dosing regimen is not the current standard of practice. Administration of idarucizumab and the use of additional reversal strategies should involve an assessment of each individual patient's severity of bleeding and subsequent risk of thrombosis. Due to the recent availability of idarucizumab and varying success with alternative reversal strategies, additional knowledge is needed for the optimal reversal of anticoagulation from dabigatran.

Los mediadores textuales como alternativa de apoyo a la docencia / Os mediadores textuais como alternativa de apoio pedagógico / Textual mediators as an alternative to teaching learning and learning

Resumen El trabajo contiene el resultado de la aplicación de un objeto de aprendizaje, conformado por una unidad didáctica sobre los fundamentos y normas del Derecho Internacional Humanitario, en estudiantes de cuarto año de la carrera de licenciatura, en Cultura Física, de la Universidad de Pinar del Río "Hermanos Saíz Montes de Oca". Se propuso en la investigación como objetivo: elaborar un objeto de aprendizaje que contribuyera a mejorar el conocimiento sobre los fundamentos y normas del Derecho Internacional Humanitario de los estudiantes de cuarto año de la carrera de Cultura Física de la Universidad de Pinar del Río "Hermanos Saíz Montes de Oca". En su elaboración, se emplearon métodos teóricos como histórico-lógico, análisis y síntesis, inductivo-deductivo; además, métodos empíricos como la observación, entrevista grupal, análisis documental, encuesta a los estudiantes y técnicas estadísticas como el análisis porcentual. Entre los principales hallazgos, la bibliografía impresa sobre el tema, para realizar las consultas necesarias y el trabajo independiente o de autopreparación por los estudiantes, era insuficiente. El libro de texto está carente de imágenes que refuercen los conocimientos. Se pudo concluir que el objeto de aprendizaje constituyó una herramienta didáctica que permitió a los estudiantes de la Facultad de Cultura Física de Pinar del Río y otras instituciones tener acceso, de manera digital, a la temática de los fundamentos y normas del Derecho Internacional Humanitario; se fortalecieron los valores en los estudiantes, en especial el humanismo; se contribuyó al aprendizaje, utilización de las técnicas informática y telecomunicaciones por los estudiantes de la Facultad de Cultura Física de Pinar del Río y otras instituciones.

Resumo O trabalho contém o resultado da aplicação de um objeto de aprendizagem constituído por uma unidade didática sobre os fundamentos e normas do Direito Internacional Humanitário, em alunos do quarto ano do curso de licenciatura em Cultura Física da Universidade de Pinar del Río "Hermanos Saíz Montes de Oca". O objetivo da pesquisa foi desenvolver um objeto de aprendizagem que contribuísse para melhorar o conhecimento dos fundamentos e normas do Direito Internacional Humanitário dos estudantes do quarto ano da carreira de Cultura Física da Universidade de Pinar del Río "Hermanos Saíz Montes de Oca". Na sua elaboração, foram utilizados métodos teóricos como histórico-lógico, análise e síntese, indutivo-dedutivo; também métodos empíricos como observação, entrevista em grupo, análise documental, levantamento estudantil e técnicas estatísticas como a análise percentual. Entre as achados principais estava que a bibliografia impressa sobre o assunto para fazer as consultas necessárias e o trabalho independente ou auto preparado dos alunos era insuficiente. Faltam ao livro didático imagens que reforcem o conhecimento. Pode-se concluir que o objeto de aprendizagem foi uma ferramenta didática que permitiu aos alunos da Faculdade de Cultura Física de Pinar del Río e outras instituições ter acesso digital ao tema dos fundamentos e normas do Direito Internacional Humanitário; que fortaleceu os valores dos alunos, especialmente o humanismo, contribuiu para a aprendizagem, uso de técnicas de informática e telecomunicação pelos alunos da Faculdade de Cultura Física de Pinar del Río e outras instituições.

Abstract The work contains the result of the application of a learning object composed by a didactic unit on the foundations and norms of International Humanitarian Law, in fourth year students of the degree course in Physical Culture of Pinar del Río University "Hermanos Saíz Montes de Oca". The objective of the research was to develop a learning object that would contribute to improve the knowledge of the foundations and norms of International Humanitarian Law of the fourth year students of the degree course in Physical Culture of Pinar del Río University "Hermanos Saíz Montes de Oca". In its elaboration, theoretical methods were used such as historical-logical, analysis and synthesis, inductive-deductive; also empirical methods such as observation, group interview, documentary analysis, student survey and statistical techniques such as percentage analysis. Among the main findings were that the printed bibliography on the subject to carry out the necessary consultations and the independent or self-prepared work by the students was insufficient. The textbook lacks images to reinforce knowledge It could be concluded that the learning object was a didactic tool that allowed the students of the Faculty of Physical Culture of Pinar del Río and other institutions to have digital access to the subject of the foundations and norms of International Humanitarian Law; that it strengthened the values in the students, especially humanism, contributed to the learning, use of computer and telecommunication techniques by the students of the Faculty of Physical Culture of Pinar del Río and other institutions.

Experimental UWB frequency analysis for implant communications.

Implantable biomedical sensors with the ability to transmit wirelessly real-time physiological data to an external unit can enable better management of chronic diseases. The IEEE Standard 802.15.6-2012 specifies the implementation of implant communications within 402-405 MHz, which unfortunately allows low data transmission rates only. Ultra wideband (UWB) interfaces within 3.1-10.6 GHz offer a number of advantages at the expense of higher path losses. Efforts to characterize the implant UWB channel have been undertaken via computer simulations, but these may not capture completely the effects on the implant radio channel of multiple physiological functions. To overcome these limitations we provide insight into the frequency-domain behavior of the UWB implant channel within 3.1-8.5 GHz based on propagation measurements in a liquid phantom and a living swine. A thorough comparison of the relative received power in phantom-based and in vivo measurements for the in-body to on-body (IB2OB) and in-body to off-body (IB2OFF) channel scenarios are presented.

Radio-frequency energy harvesting for wearable sensors.

The use of wearable biomedical sensors for the continuous monitoring of physiological signals will facilitate the involvement of the patients in the prevention and management of chronic diseases. The fabrication of small biomedical sensors transmitting physiological data wirelessly is possible as a result of the tremendous advances in ultra-low power electronics and radio communications. However, the widespread adoption of these devices depends very much on their ability to operate for long periods of time without the need to frequently change, recharge or even use batteries. In this context, energy harvesting (EH) is the disruptive technology that can pave the road towards the massive utilisation of wireless wearable sensors for patient self-monitoring and daily healthcare. Radio-frequency (RF) transmissions from commercial telecommunication networks represent reliable ambient energy that can be harvested as they are ubiquitous in urban and suburban areas. The state-of-the-art in RF EH for wearable biomedical sensors specifically targeting the global system of mobile 900/1800 cellular and 700 MHz digital terrestrial television networks as ambient RF energy sources are showcased. Furthermore, guidelines for the choice of the number of stages for the RF energy harvester are presented, depending on the requirements from the embedded system to power supply, which is useful for other researchers that work in the same area. The present authors' recent advances towards the development of an efficient RF energy harvester and storing system are presented and thoroughly discussed too.