Evolution in prostheses for sprinters with lower-limb amputation

Depuis une quinzaine d'années, les progrès techniques en appareillage ont été le facteur déterminant de la progression des performances des sportifs amputés de membre inférieur. Pour l'amputé tibial, la prothèse de course comprend un manchon gel et une emboîture solidarisés par un accrochage distal ou un vide virtuel. Par ses qualités dynamiques, le pied en fibre de carbone, garni de pointes, assure des performances remarquables. Pour l'amputé fémoral, équipé des mêmes pieds prothétiques, le genou est à biellettes et à contrôle des phases d'appui et pendulaire. Par rapport au coureur valide, le temps d'appui sur le membre appareillé est raccourci tandis que celui sur le membre sain est allongé. L'asymétrie du sprint de l'amputé tibial est discrète. C'est le travail des extenseurs de hanche qui est la principale compensation au déficit de propulsion dû à l'amputation. Chez l'amputé fémoral, l'absence de genou aggrave l'asymétrie. L'extension totale du genou prothétique, précoce en fin de phase oscillante et persistant pendant toute la phase d'appui, impose une compensation par une augmentation d'extension de la hanche controlatérale. Les transferts de charge de travail entre côté amputé et sain, par l'intermédiaire d'une hyperlordose lombaire, mettent en jeu le bassin, le tronc et les épaules. Les amputés sportifs font progresser la recherche en appareillage. Leurs orthoprothésistes acquièrent avec eux un savoir-faire dont bénéficient leurs patients non-sportifs.For about 15 years, technical advances in prosthetic treatment have been the main factor in the increased performance of athletes with lower-limb amputation. For trans-tibial amputation, the prosthesis for sprinting is composed of a gel liner and a socket joined by a locking or virtual vacuum liner. Because of these dynamic properties, the carbon prosthetic foot equipped with tacks ensures outstanding performance. For trans-femoral amputation, a hydraulic swing and a stance control unit are added to the same prosthesis. In comparison with the able-bodied runner, athletes with amputation have smaller loading times in the prosthetic limb and larger ones in the sound limb. The length of the energy-storing prosthetic foot is determined by the “up-on-the-toes” running gait. The sprinting gait with trans-tibial amputation is almost symmetrical. The hip extensor effort is the main compensation of propulsion reduction with lower-limb amputation. With trans-femoral amputation, the lack of knee increases the asymmetry. The total prosthetic knee extension (early in late-swing phase and lasting during total stance phase) compensates with extension of both hips, especially the opposite one. The amputation and sound limb load transfer with lumbar hyperlordosis concern the pelvis, trunk and shoulders. Because of athletes with amputation, research in prosthetic treatment has progressed. The development of orthotics and prostheses for such athletes has benefited non-athletes with amputation

Caffeine Encapsulation in Metal Organic Framework MIL-53(Al) at Pilot Plant Scale for Preparation of Polyamide Textile Fibers with Cosmetic Properties

Currently in the marketplace, we can find clothing items able to release skin-friendly ingredients while wearing them. These innovative products with high-added value are based on microencapsulation technology. In this work, due to its lightness, flexibility, porosity, chemical affinity and adsorption capacity, metal-organic framework (MOF) MIL-53(Al) was the selected microcapsule to be synthesized at a large scale and subsequent caffeine encapsulation. The synthesis conditions (molar ratio of reactants, solvents used, reaction time, temperature, pressure reached in the reactor and activation treatment to enhance the encapsulation capacity) were optimized by screening various scaling-up reactor volumes (from lab-scale of 40 mL to pilot plant production of 3.75 L). Two types of Al salts (Al(NO3)3·9H2O from the original recipe and Al2(SO4)3 as commercial SUFAL 8.2) were employed. The liporeductor cosmetic caffeine was selected as the active molecule for encapsulation. Caffeine (38 wt %) was incorporated in CAF@MIL-53(Al) microcapsules, as analyzed by TGA and corroborated by GC/MS and UV-vis after additive extraction. CAF@MIL-53(Al) microcapsules showed a controlled release of caffeine during 6 days at 25 °C (up to 22% of the initial caffeine). These capsules were incorporated through an industrial spinning process (with temperatures up to 260 °C) to manufacture PA-6 fibers with cosmetic properties. Up to 0.7 wt % of capsules were successfully incorporated into the fibers hosting 1700 ppm of caffeine. Fabrics were submitted to scouring, staining, and washing processes, detecting the presence of caffeine in the cosmetic fiber. © 2022 The Authors. Published by American Chemical Society

Defects in synapse structure and function precede motor neuron degeneration in Drosophila models of FUS-related ALS.

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that leads invariably to fatal paralysis associated with motor neuron degeneration and muscular atrophy. One gene associated with ALS encodes the DNA/RNA-binding protein Fused in Sarcoma (FUS). There now exist two Drosophila models of ALS. In one, human FUS with ALS-causing mutations is expressed in fly motor neurons; in the other, the gene cabeza (caz), the fly homolog of FUS, is ablated. These FUS-ALS flies exhibit larval locomotor defects indicative of neuromuscular dysfunction and early death. The locus and site of initiation of this neuromuscular dysfunction remain unclear. We show here that in FUS-ALS flies, motor neuron cell bodies fire action potentials that propagate along the axon and voltage-dependent inward and outward currents in the cell bodies are indistinguishable in wild-type and FUS-ALS motor neurons. In marked contrast, the amplitude of synaptic currents evoked in the postsynaptic muscle cell is decreased by \u3e80% in FUS-ALS larvae. Furthermore, the frequency but not unitary amplitude of spontaneous miniature synaptic currents is decreased dramatically in FUS-ALS flies, consistent with a change in quantal content but not quantal size. Although standard confocal microscopic analysis of the larval neuromuscular junction reveals no gross abnormalities, superresolution stimulated emission depletion (STED) microscopy demonstrates that the presynaptic active zone protein bruchpilot is aberrantly organized in FUS-ALS larvae. The results are consistent with the idea that defects in presynaptic terminal structure and function precede, and may contribute to, the later motor neuron degeneration that is characteristic of ALS

On Convergence Properties of Shannon Entropy

Convergence properties of Shannon Entropy are studied. In the differential setting, it is shown that weak convergence of probability measures, or convergence in distribution, is not enough for convergence of the associated differential entropies. A general result for the desired differential entropy convergence is provided, taking into account both compactly and uncompactly supported densities. Convergence of differential entropy is also characterized in terms of the Kullback-Liebler discriminant for densities with fairly general supports, and it is shown that convergence in variation of probability measures guarantees such convergence under an appropriate boundedness condition on the densities involved. Results for the discrete setting are also provided, allowing for infinitely supported probability measures, by taking advantage of the equivalence between weak convergence and convergence in variation in this setting.Comment: Submitted to IEEE Transactions on Information Theor

Defining principles for mobile apps and platforms development in citizen science

Apps for mobile devices and web-based platforms are increasingly used in citizen science projects. While extensive research has been done in multiple areas of studies, from Human-Computer Interaction to public engagement in science, we are not aware of a collection of recommendations specific for citizen science that provides support and advice for planning, design and data management of mobile apps and platforms that will assist learning from best practice and successful implementations. In two workshops, citizen science practitioners with experience in mobile application and web-platform development and implementation came together to analyse, discuss and define recommendations for the initiators of technology based citizen science projects. Many of the recommendations produced during the two workshops are applicable to citizen science project that do not use mobile devices to collect data. Therefore, we propose to closely connect the results presented here with ECSA’s Ten Principles of Citizen Science

Equity, barriers and cancer disparities: study of the Spanish Society of Medical Oncology on the access to oncologic drugs in the Spanish Regions

The Spanish Society of Medical Oncology (SEOM) has conducted a study on the access to oncologic drugs across the 17 Spanish Regions with the aim of identifying potential heterogeneities and making proposals for eliminating the barriers identified at the different levels. An Expert Panel made up of medical oncologists designed a survey on certain indications approved for 11 drugs in the approach of breast cancer, melanoma, lung cancer, prostate cancer and support treatment. This survey was sent to 144 National Health System (NHS) hospitals. 77 hospitals answered the survey. The information modules analysed were: scope of the Commission that establishes binding decisions related to drug access; conditions, stages and periods of drug application, approval and administration processes; barriers to accessing drugs. The study shows variability in drug access. The SEOM makes proposals addressed to reducing the differences identified and homogenizing drug access conditions

Equity, barriers and cancer disparities: study of the Spanish Society of Medical Oncology on the access to oncologic drugs in the Spanish Regions

[Purpose] The Spanish Society of Medical Oncology (SEOM) has conducted a study on the access to oncologic drugs across the 17 Spanish Regions with the aim of identifying potential heterogeneities and making proposals for eliminating the barriers identified at the different levels.[Methods] An Expert Panel made up of medical oncologists designed a survey on certain indications approved for 11 drugs in the approach of breast cancer, melanoma, lung cancer, prostate cancer and support treatment. This survey was sent to 144 National Health System (NHS) hospitals. [Results] 77 hospitals answered the survey. The information modules analysed were: scope of the Commission that establishes binding decisions related to drug access; conditions, stages and periods of drug application, approval and administration processes; barriers to accessing drugs. [Conclusions] The study shows variability in drug access. The SEOM makes proposals addressed to reducing the differences identified and homogenizing drug access conditions.This study was funded by SEOM

Ex-vivo changes in amino acid concentrations from blood stored at room temperature or on ice: implications for arginine and taurine measurements

Background: Determination of the plasma concentrations of arginine and other amino acids is important for understanding pathophysiology, immunopathology and nutritional supplementation in human disease. Delays in processing of blood samples cause a change in amino acid concentrations, but this has not been precisely quantified. We aimed to describe the concentration time profile of twenty-two amino acids in blood from healthy volunteers, stored at room temperature or on ice.Methods: Venous blood was taken from six healthy volunteers and stored at room temperature or in an ice slurry. Plasma was separated at six time points over 24 hours and amino acid levels were determined by high-performance liquid chromatography.Results: Median plasma arginine concentrations decreased rapidly at room temperature, with a 6% decrease at 30 minutes, 25% decrease at 2 hours and 43% decrease at 24 hours. Plasma ornithine increased exponentially over the same period. Plasma arginine was stable in blood stored on ice, with a < 10% change over 24 hours. Plasma taurine increased by 100% over 24 hours, and this change was not prevented by ice. Most other amino acids increased over time at room temperature but not on ice.Conclusion: Plasma arginine concentrations in stored blood fall rapidly at room temperature, but remain stable on ice for at least 24 hours. Blood samples taken for the determination of plasma amino acid concentrations either should be placed immediately on ice or processed within 30 minutes of collection

Role of cellular senescence and NOX4-mediated oxidative stress in systemic sclerosis pathogenesis.

Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by progressive fibrosis of skin and numerous internal organs and a severe fibroproliferative vasculopathy resulting frequently in severe disability and high mortality. Although the etiology of SSc is unknown and the detailed mechanisms responsible for the fibrotic process have not been fully elucidated, one important observation from a large US population study was the demonstration of a late onset of SSc with a peak incidence between 45 and 54 years of age in African-American females and between 65 and 74 years of age in white females. Although it is not appropriate to consider SSc as a disease of aging, the possibility that senescence changes in the cellular elements involved in its pathogenesis may play a role has not been thoroughly examined. The process of cellular senescence is extremely complex, and the mechanisms, molecular events, and signaling pathways involved have not been fully elucidated; however, there is strong evidence to support the concept that oxidative stress caused by the excessive generation of reactive oxygen species may be one important mechanism involved. On the other hand, numerous studies have implicated oxidative stress in SSc pathogenesis, thus, suggesting a plausible mechanism in which excessive oxidative stress induces cellular senescence and that the molecular events associated with this complex process play an important role in the fibrotic and fibroproliferative vasculopathy characteristic of SSc. Here, recent studies examining the role of cellular senescence and of oxidative stress in SSc pathogenesis will be reviewed

Citizen science in environmental and ecological sciences

Citizen science is an increasingly acknowledged approach applied in many scientific domains, and particularly within the environmental and ecological sciences, in which non-professional participants contribute to data collection to advance scientific research. We present contributory citizen science as a valuable method to scientists and practitioners within the environmental and ecological sciences, focusing on the full life cycle of citizen science practice, from design to implementation, evaluation and data management. We highlight key issues in citizen science and how to address them, such as participant engagement and retention, data quality assurance and bias correction, as well as ethical considerations regarding data sharing. We also provide a range of examples to illustrate the diversity of applications, from biodiversity research and land cover assessment to forest health monitoring and marine pollution. The aspects of reproducibility and data sharing are considered, placing citizen science within an encompassing open science perspective. Finally, we discuss its limitations and challenges and present an outlook for the application of citizen science in multiple science domains