Effect of Europium and Gadolinium Alloying Elements on the Tribological Response of Low Hydrogen Content Amorphous Carbon.

Dopants and alloying elements are commonly introduced in amorphous carbon (a-C) materials to tailor their mechanical and tribological properties. While most published studies have focused on doping and alloying a-C coatings with metals or metalloids, doping a-C films with rare-earth elements has only recently been explored. Notably, our understanding of the shear-induced structural changes occurring in rare-earth-element-containing a-C films is still elusive, even in the absence of any liquid lubricants. Here, the friction response of Eu- and Gd-containing a-C films with low hydrogen content deposited by HiPIMS on silicon was evaluated in open air and at room temperature. The load-dependent friction measurements indicated that the introduction of Gd ((2.3 ± 0.1) at.%) and Eu ((2.4 ± 0.1) at.%) into the a-C matrix results in a significant reduction of the shear strength of the sliding interfaces ((41 ± 2) MPa for a-C, (16 ± 1) MPa for a-C:Gd2.3 at.%, and (11 ± 2) MPa for a-C:Eu2.4 at.%). NEXAFS spectromicroscopy experiments provided evidence that no stress-assisted sp3-to-sp2 rehybridization of carbon atoms was induced by the sliding process in the near-surface region of undoped a-C, while the amount of sp2-bonded carbon progressively increased in a-C:Gd2.3 at.% and a-C:Eu2.4 at.% upon increasing the applied normal load in tribological tests. The formation of an sp2-bonded carbon-rich surface layer in a-C:Gd2.3 at.% and a-C:Eu2.4 at.% films was not only proposed to be the origin for the reduced duration of the running-in period in tribological test, but was also postulated to induce shear localization within the sp2-carbon-rich layer and transfer film formation on the countersurface, thus decreasing the interfacial shear strength. These findings open the path for the use of Gd- and Eu-containing a-C even under critical conditions for nearly hydrogen-free a-C films (i.e., humid air).

The Potential of Using Cochayuyo (Durvillaea incurvata) Extract Obtained by Ultrasound-Assisted Extraction to Fight against Aging-Related Diseases.

The world's population is in a demographical transition, with an increase in the number of older adults and prevalence of diseases related to aging. This study evaluated in vitro the potential of using Durvillaea incurvata extract (extracted using ultrasound-assisted extraction) to inhibit key enzymes associated with the development of age-related diseases. Our results show that an extract extracted via ultrasound-assisted extracted, as well as an extract conventional extracted from Durvillaea incurvata, presented antidiabetes potential by exhibiting inhibitory activity against α-glucosidase (91.8 ± 1.0% and 93.8 ± 0.3%, respectively, at 500 µg/mL) and α-amylase (42.2 ± 1.4% and 61.9 ± 0.9%, respectively, at 1500 µg/mL) enzymes related to starch digestion and postprandial glycemic response. Also, the extracts showed inhibitory activity against the enzymes acetylcholinesterase (51.5% and 50.8%, respectively, at 500 µg/mL) and butyrylcholinesterase (32.8% and 34.4%, respectively, at 0.5 mg/mL), the biomarkers associated with Alzheimer's disease, and angiotensin-converting enzyme (98.7 ± 7.4% and 93.0 ± 3.4%, respectively, at 2.0 mg/mL), which is key in the regulation of vascular tone and blood pressure and helps to prevent the development of hypertension. In conclusion, the extract of Durvillaea incurvata obtained from ultrasound-assisted extraction has the potential to prevent the development of age-related pathologies such as diabetes, Alzheimer's disease, and hypertension.

Spectroscopic Evaluation of Surface Chemical Processes Occurring in MoS2 upon Aging.

Molybdenum disulfide (MoS2) coatings have attracted widespread industrial interest owing to their excellent lubricating properties under vacuum and inert conditions. Unfortunately, the increase in MoS2 interfacial shear strength following prolonged exposure to ambient conditions (a process referred to as "aging") has resulted in reliability issues when MoS2 is employed as solid lubricant. While aging of MoS2 is generally attributed to physical and chemical changes caused by adsorbed water and/or oxygen, a mechanistic understanding of the relative role of these two gaseous species in the evolution of the surface chemistry of MoS2 is still elusive. Additionally, remarkably little is known about the effect of thermally- and tribologically-induced microstructural variations in MoS2 on the aging processes occurring in the near-surface region of the coating. Here, we employed three analytical techniques, namely, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and grazing-incidence X-ray diffraction (GIXRD), to gain insights into the aging phenomena occurring in sputtered MoS2 coatings before and after tribological testing, while also evaluating the impact of thermally-induced variations in the coating structure on aging. The outcomes of XPS analyses provide evidence that a substantial surface oxidation of MoS2 only takes place under humid conditions. Furthermore, the correlation of XPS, ToF-SIMS, and GIXRD results allowed for the development of a qualitative model for the impact of shear-induced microstructural variations in MoS2 on the transport of water in the near-surface region of this material and on the extent of surface oxidation. These results add significantly to our understanding of the aging mechanisms of MoS2 coatings used in tribological applications and their dependence on environmental conditions.

Identification of coronaviruses in bats and rodents in northern and central Argentina.

Due to the present pandemic situation and the many animal species that are epidemiologically involved, there has been a surge of renewed interest in investigating the coronavirus (CoV) population circulating in wildlife, especially bats and rodents, which are potential reservoirs of new human pathogens. In Argentina, information about the viruses present in these mammals is very limited. To investigate the presence of coronaviruses in this country, we obtained 457 samples from hematophagous, insectivorous, and frugivorous bats and rodents from two regions of Argentina. We report here the detection of alphacoronavirus sequences in three groups of bats as well as in rodents. Phylogenetic analysis showed the closest relationships to alphacoronaviruses from Brazil.

Enhancing Multimodal Patterns in Neuroimaging by Siamese Neural Networks with Self-Attention Mechanism.

The combination of different sources of information is currently one of the most relevant aspects in the diagnostic process of several diseases. In the field of neurological disorders, different imaging modalities providing structural and functional information are frequently available. Those modalities are usually analyzed separately, although a joint of the features extracted from both sources can improve the classification performance of Computer-Aided Diagnosis (CAD) tools. Previous studies have computed independent models from each individual modality and combined them in a subsequent stage, which is not an optimum solution. In this work, we propose a method based on the principles of siamese neural networks to fuse information from Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET). This framework quantifies the similarities between both modalities and relates them with the diagnostic label during the training process. The resulting latent space at the output of this network is then entered into an attention module in order to evaluate the relevance of each brain region at different stages of the development of Alzheimer's disease. The excellent results obtained and the high flexibility of the method proposed allow fusing more than two modalities, leading to a scalable methodology that can be used in a wide range of contexts.

Endometrial injury and rFSH before frozen-thawed embryo transfer: a case report.

Hormonal treatment as endometrial preparation for frozen-thawed embryo transfer (FET) is routinely carried out with oral, transdermal or combined estradiol supplementation; however, in some cases, there is no optimal endometrial development with this type of stimulation. In this case report, our patient failed to respond to conventional endometrial preparation techniques. For this reason, two unconventional techniques were combined to improve endometrial receptivity; endometrial injury, followed by rFSH administration. As a result of this combination, we achieved endometrium thickness, reaching 8.9 mm on day 15 of the cycle, carrying out the embryo transfer of two blastocysts on day-17 of the cycle, achieving clinical pregnancy and carrying it to completion with the birth of a baby.

Assessing Functional Brain Network Dynamics in Dyslexia from fNIRS Data.

Developmental dyslexia is characterized by a deficit of phonological awareness whose origin is related to atypical neural processing of speech streams. This can lead to differences in the neural networks that encode audio information for dyslexics. In this work, we investigate whether such differences exist using functional near-infrared spectroscopy (fNIRS) and complex network analysis. We have explored functional brain networks derived from low-level auditory processing of nonspeech stimuli related to speech units such as stress, syllables or phonemes of skilled and dyslexic seven-year-old readers. A complex network analysis was performed to examine the properties of functional brain networks and their temporal evolution. We characterized aspects of brain connectivity such as functional segregation, functional integration or small-worldness. These properties are used as features to extract differential patterns in controls and dyslexic subjects. The results corroborate the presence of discrepancies in the topological organizations of functional brain networks and their dynamics that differentiate between control and dyslexic subjects, reaching an Area Under ROC Curve (AUC) up to 0.89 in classification experiments.

Realce tardío con gadolinio en resonancia magnética cardiaca de 3 T para la evaluación de la anatomía venosa coronaria: factibilidad y hallazgos / Tridimensional late gadolinium enhancement at 3 T cardiac magnetic resonance for the evaluation of coronary venous anatomy: feasibility and findings

Objetivo:El conocimiento de la anatomía venosa coronaria (AVC) tiene importancia crítica para planificar y realizar procedimientos electrofisiológicos como la terapia de resincronización cardiaca (TRC), la terapia de ablación del ventrículo izquierdo y la aurícula derecha y el mapeo de arritmias por catéter. El objetivo es evaluar la viabilidad y las aplicaciones de la resonancia magnética (RM) cardiaca realizada en 3T para la representación no invasiva de la AVC empleando una secuencia tridimensional de realce tardío con gadolinio (RTG-3D). Metodología:Se evaluaron 138 pacientes consecutivos que se sometieron a RM cardiaca 3 T mediante una secuencia RTG-3D durante un año, entre 2016 y 2017. Se identificaron diferentes estructuras venosas coronarias, así como su relación con la fibrosis miocárdica, y otras variables clínicas relevantes. La evaluación de la calidad se realizó mediante tres grupos (óptimos, buenos, malos) de acuerdo con la evaluación visual de cada estudio individual. Se realizaron pruebas de asociación (Chi-cuadrado y Kruskall-Wallis). Resultados:El estudio incluyó 62 mujeres y 76 hombres con una edad promedio de 48 (29-61) años. La secuencia RTG-3D arrojó una calidad diagnóstica (óptima-buena) para la evaluación del AVC en el 76 % de los pacientes (p < 0,001). Se identificaron las siguientes estructuras (pacientes, %): vena interventricular anterior: 110 (79,7 %), gran vena cardiaca: 109 (79 %), vena interventricular posterior: 106 (76,8 %), vena marginal: 53 pacientes (38,4 %) y vena posterolateral: 74 (53,6 %). Se identificó fibrosis miocárdica en 42 pacientes y se registró afectación fibrótica epicárdica de al menos un trayecto en una de las venas coronarias en el 12 % de los pacientes de este subgrupo. Los periodos de adquisición más cortos (p < 0,02) y la realización del estudio bajo anestesia general (p < 0,03) dieron como resultado una calidad del estudio significativamente mejor. Conclusiones:La evaluación no invasiva de la AVC es factible con la secuencia RTG-3D obtenida en 3T RM cardiaca. Este enfoque puede ofrecer una valiosa herramienta clínica para la planificación de procedimientos electrofisiológicos.

Objetivo:El conocimiento de la anatomía venosa coronaria (AVC) tiene importancia crítica para planificar y realizar procedimientos electrofisiológicos como la terapia de resincronización cardiaca (TRC), la terapia de ablación del ventrículo izquierdo y la aurícula derecha y el mapeo de arritmias por catéter. El objetivo es evaluar la viabilidad y las aplicaciones de la resonancia magnética (RM) cardiaca realizada en 3T para la representación no invasiva de la AVC empleando una secuencia tridimensional de realce tardío con gadolinio (RTG-3D). Metodología:Se evaluaron 138 pacientes consecutivos que se sometieron a RM cardiaca 3 T mediante una secuencia RTG-3D durante un año, entre 2016 y 2017. Se identificaron diferentes estructuras venosas coronarias, así como su relación con la fibrosis miocárdica, y otras variables clínicas relevantes. La evaluación de la calidad se realizó mediante tres grupos (óptimos, buenos, malos) de acuerdo con la evaluación visual de cada estudio individual. Se realizaron pruebas de asociación (Chi-cuadrado y Kruskall-Wallis). Resultados:El estudio incluyó 62 mujeres y 76 hombres con una edad promedio de 48 (29-61) años. La secuencia RTG-3D arrojó una calidad diagnóstica (óptima-buena) para la evaluación del AVC en el 76 % de los pacientes (p < 0,001). Se identificaron las siguientes estructuras (pacientes, %): vena interventricular anterior: 110 (79,7 %), gran vena cardiaca: 109 (79 %), vena interventricular posterior: 106 (76,8 %), vena marginal: 53 pacientes (38,4 %) y vena posterolateral: 74 (53,6 %).

Resonancia magnética cardiaca: utilidad de la secuencia de realce tardío 3D (RT-3D) en electrofisiología / Cardiac magnetic resonance: usefulness of the 3D late enhancement sequence (RT-3D) in electrophysiology

Resumen La resonancia magnética cardiaca permite una evaluación integral del corazón, provee información de funcionalidad, anatómica y de caracterización tisular, y permite la valoración de la perfusión miocárdica. Entre las secuencias de caracterización tisular se encuentra el realce tardío, el cual ocurre en corazones con fibrosis, trastornos infiltrativos o procesos agudos como miocarditis o infarto agudo de miocardio. Para el área de la electrofisiología, la resonancia magnética cardiaca aporta una gran ayuda en el abordaje diagnóstico de las miocardiopatías isquémicas y no isquémicas, y apoyo para definir el pronóstico de los pacientes con miocardiopatías de acuerdo con la presencia o no de fibrosis miocárdica; además, como parámetro adicional ha demostrado utilidad para la adecuada toma de decisiones en el implante de cardiodesfibriladores en prevención primaria y el implante de terapia de resincronización cardiaca. También ha probado ser de utilidad como guía en la terapia de ablación de la aurícula y el ventrículo izquierdos, y el seguimiento posablación de venas pulmonares para detectar líneas discontinuas de ablación.

Abstract Cardiac magnetic resonance imaging allows a comprehensive evaluation of the heart, provides information on functionality, anatomy, tissue characterization and allows the evaluation of myocardial perfusion. Tissue characterization sequences include late enhancement, which occurs in hearts with fibrosis, infiltrative disorders, or in acute processes such as myocarditis or acute myocardial infarction. In the area of electrophysiology, cardiac magnetic resonance imaging is of great assistance in the diagnostic approach of ischemic and non-ischemic cardiomyopathies, supports in defining the prognosis of patients with cardiomyopathies according to the presence or absence of myocardial fibrosis, and also as an additional parameter that has been shown to be useful for taking adequate decisions in the implantation of cardioverter defibrillators in primary prevention and the implantation of cardiac resynchronization therapy. It has also proven to be useful as a guide in ablation therapy for the left atrium and left ventricle and its post-ablation monitoring of pulmonary veins to detect discontinuous lines of ablation.