Artificial Motor Control For Electrically Stimulated Upper Limbs Of Plegic Or Paretic People

Functional Electrical Stimulation (FES) is a technique used in the restoration and generation of movements performed by subjects with neuromuscular disorders such as spinal cord injury (SCI). The purpose of this article is to outline the state of the art and perspectives of the use of FES in artificial motor control of the upper limbs in paretic or plegic people. Methods: The databases used in papers selection were Google Scholar and Capes’ Portals as well as proceedings of the Annual Conference of the International Functional Electrical Stimulation Society (IFESS). Results: Approximately 85% of the reviewed studies showed FES profile with pulse duration ranging from 1 to 300 μs and modulating (burst) frequency between 10 and 40 Hz. Regarding the type of electrodes, 88% of the studies employed transcutaneous electrodes. Conclusion: We concluded that FES with closed-loop feedback and feedforward are the most used and most viable systems for upper limbs motor control, because they perform self-corrections slowing neuromuscular adaptation, allowing different planes and more range of movement and sensory-motor integration. One of the difficulties found in neuroprosthesis systems are electrical wires attached to the user, becoming uninteresting in relation to aesthetics and break. The future perspectives lead to a trend to miniaturization of the stimulation equipment and the availability of wireless networks, which allow the attachment of modules to other components without physical contact, and will become more attractive for daily use. © 2016, Sociedade Brasileira de Engenharia Biomedica. All rights reserved.32219921

Mitochondrial bioenergetics deregulation caused by long-chain 3-hydroxy fatty acids accumulating in LCHAD and MTP deficiencies in rat brain: A possible role of mPTP opening as a pathomechanism in these disorders?

AbstractLong-chain 3-hydroxylated fatty acids (LCHFA) accumulate in long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies. Affected patients usually present severe neonatal symptoms involving cardiac and hepatic functions, although long-term neurological abnormalities are also commonly observed. Since the underlying mechanisms of brain damage are practically unknown and have not been properly investigated, we studied the effects of LCHFA on important parameters of mitochondrial homeostasis in isolated mitochondria from cerebral cortex of developing rats. 3-Hydroxytetradecanoic acid (3 HTA) reduced mitochondrial membrane potential, NAD(P)H levels, Ca2+ retention capacity and ATP content, besides inducing swelling, cytochrome c release and H2O2 production in Ca2+-loaded mitochondrial preparations. We also found that cyclosporine A plus ADP, as well as ruthenium red, a Ca2+ uptake blocker, prevented these effects, suggesting the involvement of the mitochondrial permeability transition pore (mPTP) and an important role for Ca2+, respectively. 3-Hydroxydodecanoic and 3-hydroxypalmitic acids, that also accumulate in LCHAD and MTP deficiencies, similarly induced mitochondrial swelling and decreased ATP content, but to a variable degree pending on the size of their carbon chain. It is proposed that mPTP opening induced by LCHFA disrupts brain bioenergetics and may contribute at least partly to explain the neurologic dysfunction observed in patients affected by LCHAD and MTP deficiencies

Experimental aerothermal characterization of surface air-cooled oil coolers for turbofan engines

[EN] Thermal management is a major challenge for new generation turbofan aero-engines. One of the most promising heat exchangers are the so-called surface air-cooled oil coolers (SACOCs). In this study, an experimental methodology is proposed and implemented in order to characterize SACOCs mounted in turbofan bypass ducts. Three different SACOC geometries have been characterized under the same nominal operating point, while the actual velocity profile in the bypass was reproduced by means of a distortion screen upstream the test section. The heat exchangers were mounted in counterflow configuration and feature the same fin geometry in the oil side. The three prototypes varied only in the air side, being the first a baseline flat plate, the second a SACOC with standard trapezoidal fins and the third featuring optimized fins designed to reduce the pressure drop. Aerothermal results demonstrated that the effect of the SACOC on the bypass flow was confined to a region about the same height and width of the finned area, avoiding the need of reproducing the whole bypass duct. However, for this reduced-height experimental approach to be valid, we show that the velocity profile needs to be rearranged to match the specific section of the whole bypass. We also demonstrate how the optimized fin geometry achieved a 10% lower friction factor than the standard one at nominal flow conditions while increasing the overall heat transfer coefficient by 5.2%.This project has received funding from the Clean Sky 2 Joint Undertaking under the European Union's Horizon 2020 research and innovation programme under grant agreement n° 831977: Aerodynamic upgrade of Surface Air-Cooled Oil Coolers (SACOC). A. Felgueroso is supported through the Programa de Apoyo para la Investigación y Desarrollo of the Universitat Politècnica de València under grant PAID-01-20 n° 21589. The authors also wish to thank Safran Aircraft Engines for their kind permission to share the data presented in this publication. Special thanks are also given to Mr. Adolfo Guzmán for his inestimable support during the experimental campaign.Broatch, A.; Olmeda, P.; Garcia Tiscar, J.; Felgueroso-Rodríguez, A.; Chávez-Modena, M.; González, LM.; Gelain, M.... (2022). Experimental aerothermal characterization of surface air-cooled oil coolers for turbofan engines. International Journal of Heat and Mass Transfer. 190:1-13. https://doi.org/10.1016/j.ijheatmasstransfer.2022.12277511319

Experimental aerothermal characterization of surface air-cooled oil coolers for turbofan engines

[EN] Thermal management is a major challenge for new generation turbofan aero-engines. One of the most promising heat exchangers are the so-called surface air-cooled oil coolers (SACOCs). In this study, an experimental methodology is proposed and implemented in order to characterize SACOCs mounted in turbofan bypass ducts. Three different SACOC geometries have been characterized under the same nominal operating point, while the actual velocity profile in the bypass was reproduced by means of a distortion screen upstream the test section. The heat exchangers were mounted in counterflow configuration and feature the same fin geometry in the oil side. The three prototypes varied only in the air side, being the first a baseline flat plate, the second a SACOC with standard trapezoidal fins and the third featuring optimized fins designed to reduce the pressure drop. Aerothermal results demonstrated that the effect of the SACOC on the bypass flow was confined to a region about the same height and width of the finned area, avoiding the need of reproducing the whole bypass duct. However, for this reduced-height experimental approach to be valid, we show that the velocity profile needs to be rearranged to match the specific section of the whole bypass. We also demonstrate how the optimized fin geometry achieved a 10% lower friction factor than the standard one at nominal flow conditions while increasing the overall heat transfer coefficient by 5.2%.This project has received funding from the Clean Sky 2 Joint Undertaking under the European Union's Horizon 2020 research and innovation programme under grant agreement n° 831977: Aerodynamic upgrade of Surface Air-Cooled Oil Coolers (SACOC). A. Felgueroso is supported through the Programa de Apoyo para la Investigación y Desarrollo of the Universitat Politècnica de València under grant PAID-01-20 n° 21589. The authors also wish to thank Safran Aircraft Engines for their kind permission to share the data presented in this publication. Special thanks are also given to Mr. Adolfo Guzmán for his inestimable support during the experimental campaign.Broatch, A.; Olmeda, P.; Garcia Tiscar, J.; Felgueroso-Rodríguez, A.; Chávez-Modena, M.; González, LM.; Gelain, M.... (2022). Experimental aerothermal characterization of surface air-cooled oil coolers for turbofan engines. International Journal of Heat and Mass Transfer. 190:1-13. https://doi.org/10.1016/j.ijheatmasstransfer.2022.12277511319

Sorted-pareto dominance and qualitative notions of optimality

Pareto dominance is often used in decision making to compare decisions that have multiple preference values – however it can produce an unmanageably large number of Pareto optimal decisions. When preference value scales can be made commensurate, then the Sorted-Pareto relation produces a smaller, more manageable set of decisions that are still Pareto optimal. Sorted-Pareto relies only on qualitative or ordinal preference information, which can be easier to obtain than quantitative information. This leads to a partial order on the decisions, and in such partially-ordered settings, there can be many different natural notions of optimality. In this paper, we look at these natural notions of optimality, applied to the Sorted-Pareto and min-sum of weights case; the Sorted-Pareto ordering has a semantics in decision making under uncertainty, being consistent with any possible order-preserving function that maps an ordinal scale to a numerical one. We show that these optimality classes and the relationships between them provide a meaningful way to categorise optimal decisions for presenting to a decision maker

Systemic Inflammation Changes the Site of RAGE Expression from Endothelial Cells to Neurons in Different Brain Areas

The receptor for advanced glycation endproducts (RAGE) is a transmembrane, immunoglobulin-like receptor that interacts with a broad repertoire of extracellular ligands. RAGE belongs to a family of cell adhesion molecules and is considered a key receptor in the inflammation axis and a potential contributor to the neurodegeneration. The present study aimed to investigate the content and cell localization of RAGE in the brain of Wistar rats subjected to systemic inflammation induced by a single dose of lipopolysaccharide (LPS, 5 mg/kg, i.p.). Fifteen days after LPS administration, the content of RAGE was analyzed in the prefrontal cortex (PFC), hippocampus (HIPP), cerebellum (CB), and substantia nigra (SN) were investigated. RAGE levels increased in all structures, except HIPP; however, immunohistochemistry analysis demonstrated that the cell site of RAGE expression changed from blood vessel-like structures to neuronal cells in all brain areas. Besides, the highest level of RAGE expression was found in SN. Immunofluorescence analysis in SN confirmed that RAGE expression was mainly co-localized in endothelial cells (RAGE/PECAM-1 co-staining) in untreated animals, while LPS-treated animals had RAGE expression predominantly in dopaminergic neurons (RAGE/TH co-staining). Decreased TH levels, as well as increased pro-inflammatory markers (TNF-α, IL-1β, Iba-1, GFAP, and phosphorylated ERK1/2) in SN, occurred concomitantly to RAGE stimulation in the same site. These results suggest a role for RAGE in the establishment of a neuroinflammation-neurodegeneration axis that develops as a long-term response to systemic inflammation by LPS

Splenic marginal zone lymphoma in 5 dogs (2001-2008)

Background: Splenic marginal zone lymphomas (MZL) in dogs arise from the marginal zone of B-cell follicles and can progress slowly.Objectives: To describe clinical features, treatment, and outcome of dogs with splenic MZL.Animals: Five dogs with naturally occurring MZL.Methods: Clinical, laboratory, and follow-up data were retrospectively reviewed. Diagnosis was based on clinical, histopathological, and immunophenotypic features.Results: All dogs had stage IV disease; among them, 2 were symptomatic (substage "b") because of splenic rupture. Four dogs underwent splenectomy and adjuvant doxorubicin, and 1 dog underwent surgery only. Three out of the 4 dogs treated with surgery and chemotherapy died of causes unrelated to lymphoma, after 760, 939, and 1,825 days, whereas the remaining dog was alive and in complete remission after 445 days. The dog not receiving any adjuvant treatment had recurrence of the tumor after 180 days.Conclusions and Clinical Importance: Splenic MZL appears indolent and can benefit from splenectomy, with or without systemic chemotherapy

Screening of candidate G-quadruplex ligands for the human c-KIT promotorial region and their effects in multiple in-vitro models

Stabilization of G-quadruplex (G4) structures in promoters is a novel promising strategy to regulate gene expression at transcriptional and translational levels. c-KIT proto-oncogene encodes for a tyrosine kinase receptor. It is involved in several physiological processes, but it is also dysregulated in many diseases, including cancer. Two G-rich sequences able to fold into G4, have been identified in c-KIT proximal promoter, thus representing suitable targets for anticancer intervention. Herein, we screened an \u201cin house\u201d library of compounds for the recognition of these G4 elements and we identified three promising ligands. Their G4-binding properties were analyzed and related to their antiproliferative, transcriptional and post-transcriptional effects in MCF7 and HGC27 cell lines. Besides c-KIT, the transcriptional analysis covered a panel of oncogenes known to possess G4 in their promoters. From these studies, an anthraquinone derivative (AQ1) was found to efficiently downregulate c-KIT mRNA and protein in both cell lines. The targeted activity of AQ1 was confirmed using c-KIT\u2013dependent cell lines that present either c-KIT mutations or promoter engineered (i.e., \u3b1155, HMC1.2 and ROSA cells). Present results indicate AQ1 as a promising compound for the target therapy of c-KIT-dependent tumors, worth of further and in depth molecular investigations

Characterization of Blood Oxidative Stress in Type 2 Diabetes Mellitus Patients: Increase in Lipid Peroxidation and SOD Activity

This study evaluated the oxidative stress through enzymatic and nonenzymatic biomarkers in diabetic patients with and without hypertension and prediabetics. The SOD and CAT (in erythrocytes) and GPx (in plasma) enzymatic activities, plasma levels of lipid peroxidation, and total thiols were measured in the blood of 55 subjects with type 2 diabetes and 38 subjects without diabetes (9 pre-diabetics and 29 controls) aged 40–86 years. The total SOD activity and the lipid peroxidation were higher in diabetics compared to nondiabetics. In stratified groups, the total SOD activity was different for the hypertensive diabetics compared to the prediabetics and normotensive controls. Lipid peroxidation was significantly higher in both groups of diabetics (hypertensive and normotensive) compared to prediabetic groups and hypertensive and normotensive controls. There was no significant difference in the CAT and GPx activities, as well as in the concentration of total thiols in the groups studied. Present data strongly suggest the involvement of oxidative stress in the pathophysiology of diabetes, revealing that the increased lipid peroxidation has a close relationship with high glucose levels, as observed by the fasting glucose and HbA1c levels. The results evidence the correlation between lipid peroxidation and DM, irrespective of the presence of hypertension

Biological Designer Self-Assembling Peptide Nanofiber Scaffolds Significantly Enhance Osteoblast Proliferation, Differentiation and 3-D Migration

A class of self-assembling peptide nanofiber scaffolds has been shown to be an excellent biological material for 3-dimension cell culture and stimulating cell migration into the scaffold, as well as for repairing tissue defects in animals. We report here the development of several peptide nanofiber scaffolds designed specifically for osteoblasts. We designed one of the pure self-assembling peptide scaffolds RADA16-I through direct coupling to short biologically active motifs. The motifs included osteogenic growth peptide ALK (ALKRQGRTLYGF) bone-cell secreted-signal peptide, osteopontin cell adhesion motif DGR (DGRGDSVAYG) and 2-unit RGD binding sequence PGR (PRGDSGYRGDS). We made the new peptide scaffolds by mixing the pure RAD16 and designer-peptide solutions, and we examined the molecular integration of the mixed nanofiber scaffolds using AFM. Compared to pure RAD16 scaffold, we found that these designer peptide scaffolds significantly promoted mouse pre-osteoblast MC3T3-E1 cell proliferation. Moreover, alkaline phosphatase (ALP) activity and osteocalcin secretion, which are early and late markers for osteoblastic differentiation, were also significantly increased. We demonstrated that the designer, self-assembling peptide scaffolds promoted the proliferation and osteogenic differentiation of MC3T3-E1. Under the identical culture medium condition, confocal images unequivocally demonstrated that the designer PRG peptide scaffold stimulated cell migration into the 3-D scaffold. Our results suggest that these designer peptide scaffolds may be very useful for promoting bone tissue regeneration