Publications by authors named "Clarac"

Introduction: Microcephalic osteodysplastic primordial dwarfism (MOPD) syndrome type 2, caused by a mutation in the PCNT gene (21q22.3), is a rare autosomal recessive disorder. Patients present with bone dysplasia, insulin resistance, kidney diseases, and cardiac malformations, making them prone to vascular diseases.

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  • - Li(NiCoAl)O is a long-time lithium-ion battery cathode known for its high energy capacity and density but moderate power, making it a reliable choice for energy storage.
  • - Atomic layer fluorination (ALF) with XeF is used to enhance the battery's cyclability by creating a protective fluorinated layer with minimal fluorine content (only 1.4 wt%).
  • - Various characterization techniques show that adding fluorine improves the electrochemical performance of Li(NiCoAl)O, enhancing its cyclability, polarization, and rate capability, with further insights into these benefits obtained from infrared spectroscopy and gas chromatography.
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Background: Lateropulsion is a deficit in body orientation with respect to gravity, frequent after stroke. Although it is a primary factor affecting mobility, the impact of its attenuation on balance and gait recovery has never been investigated. Moreover, most studies on the lateropulsion time-course focus on severe forms suspected to have a poor recovery, which is not proven.

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Objective: To test the hypothesis that lateropulsion is an entity expressing an impaired body orientation with respect to gravity in relation to a biased graviception and spatial neglect.

Methods: Data from the DOBRAS cohort (ClinicalTrials.gov: NCT03203109) were collected 30 days after a first hemisphere stroke.

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Objective: To test the hypothesis that impaired body orientation with respect to gravity (lateropulsion) would play a key role in poststroke balance and gait disorders.

Methods: Cohort study of 220 individuals consecutively admitted to a neurorehabilitation ward after a first hemisphere stroke (DOBRAS cohort [Determinants of Balance Recovery After Stroke] 2012-2018, ClinicalTrials.gov: NCT03203109), with clinical data systematically collected at 1 month, then at discharge.

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  • An unusual 24% prevalence of Klebsiella pneumoniae was found in 25 adults with community-acquired bacterial meningitis in ICU units of two University Hospitals in the French West Indies.
  • The isolated strains displayed characteristics typical of hypervirulent bacteria, such as the presence of rmpa and iuc genes.
  • Most of the isolates also belonged to capsular serotypes K1 or K2, which are known to be more virulent.
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Background: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak is spreading worldwide. To date, no specific treatment has convincingly demonstrated its efficacy. Hydroxychloroquine and lopinavir/ritonavir have potential interest, but virological and clinical data are scarce, especially in critically ill patients.

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Studies on living turtles have demonstrated that shells are involved in the resistance to hypoxia during apnea via bone acidosis buffering; a process which is complemented with cutaneous respiration, transpharyngeal and cloacal gas exchanges in the soft-shell turtles. Bone acidosis buffering during apnea has also been identified in crocodylian osteoderms, which are also known to employ heat transfer when basking. Although diverse, many of these functions rely on one common trait: the vascularization of the dermal shield.

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The crocodylians are ectothermic semi-aquatic vertebrates which are assessed to have evolved from endothermic terrestrial forms during the Mesozoic. Such a physiological transition should have involved modifications in their cardio-vascular system allowing to increase the heat transfers with the surrounding environment by growing a peripheral vascularization which would be mainly located in the dermal skeleton: the dermatocranium and the osteoderms. In order to assess the implication of these anatomical regions in thermal exchanges, we have recorded the temperature above a set of representative skin areas in order to draw comparisons between the skull, the osteoderms, and the rest of the body parts which present either none or residual dermal ossification.

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In order to assess the implication of the crocodylomorph ornamented osteoderms on the skin conduction during basking, we have performed three dimensional modeling and finite element analyses on a sample which includes both extant dry bones and well-preserved fossils tracing back to the Early Jurassic. In purpose to reveal the possible implication of the superficial ornamentation on the osteoderm heat conduction, we repeated the simulation on an equivalent set of smoothed 3D-modeled osteoderms. The comparison of the results evidenced that the presence of the apical sculpture has no significant impact on the osteoderm global conduction.

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Vascularization in the core of crocodylian osteoderms, and in their superficial pits has been hypothesized to be a key feature involved in physiological thermoregulation and/or acidosis buffering during anoxia (apnea). However, up to now, there have been no quantitative data showing that the inner, or superficial, blood supply of the osteoderms is greater than that occurring in neighboring dermal tissues. We provide such data: our results clearly indicate that the vascular networks in both the osteoderms and the pits forming their superficial ornamentation are denser than in the overlying dermis.

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Two successive mechanisms have been described in perichondral ossification: (1) in static osteogenesis, mesenchymal cells differentiate into stationary osteoblasts oriented randomly, which differentiate into osteocytes in the same site; (2) in dynamic osteogenesis, mesenchymal cells differentiate into osteoblasts that are all oriented in the same direction and move back as they secrete collagen fibers. This study is aimed at testing the hypothesis that the ontogenetic sequence static then dynamic osteogenesis observed in the chicken and in the rabbit is homologous and was acquired by the last common ancestor of amniotes or at a more inclusive node. For this we analyze the developmental patterns of Pleurodeles (Caudata, Amphibia) and those of the lizard Pogona (Squamata, Lepidosauria).

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Previous quantitative assessments of the crocodylians' dermal bone ornamentation (this ornamentation consists of pits and ridges) has shown that bone sculpture results in a gain in area that differs between anatomical regions: it tends to be higher on the skull table than on the snout. Therefore, a comparative phylogenetic analysis within 17 adult crocodylian specimens representative of the morphological diversity of the 24 extant species has been performed, in order to test if the gain in area due to ornamentation depends on the skull morphology, i.e.

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Article Synopsis
  • Bone ornamentation, characterized by pits and ridges, is common among various gnathostome taxa, but the processes behind its development are debated.
  • Different mechanisms, including simple differential growth and more complex remodeling cycles, vary across taxa in how these features form.
  • Some clades show consistency in their ornamentation development methods, while others, like Actinopterygii, exhibit diverse mechanisms; this suggests that bone ornamentation is often an unreliable evolutionary trait due to convergence from similar environmental pressures.
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Bone ornamentation, in the form of highly repetitive motives created by pits and ridges, is a frequent feature on vertebrate skull roofs and osteoderms. The functional significance of this character remains a matter of controversy and speculation. The many diverging hypotheses proposed to explain it all share a common logical prerequisite: bone ornamentation should increase significantly the surface area of the bones that bear it.

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Bone ornamentation, that is, hollow (pits and grooves) or protruding (ridges) repetitive reliefs on the surface of dermal bones, is a frequent, though poorly studied and understood, feature in vertebrates. One of the most typical examples of this characteristic is given by the Crurotarsi, a taxon formed by the crocodilians and their closest allies, which generally display deep ornamentation on skull roof and osteoderms. However, the ontogenetic process responsible for the differentiation and development of this character remains controversial.

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We present a short historical review on the major institutions and figures who contributed to make Paris a renowned centre of physiology and neurology during the XIXth and the first half of the XXth century. We purposely chose to focus on the period 1800-1950, as 1800 corresponds to the actual beginning of neurosciences, and as 1950 marks their exponential rise. Our presentation is divided into four chapters, matching the main disciplines that have progressed and contributed most to the knowledge we have of the brain sciences: anatomy, physiology, neurology, and psychiatry-psychology.

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We present a short historical review of the major figures, their administrative functions and their works that contributed to make Paris a renowned centre of physiology and neurology during the xixth and the first half of the xxth century. We purposely chose to focus on the period 1800-1950, as 1800 corresponds to the actual beginning of neurosciences, and 1950 marks their exponential rise. Our presentation is divided into four chapters, matching the main disciplines which have progressed and contributed the most to the knowledge we have of the brain sciences: anatomy, physiology, neurology, and psychiatry-psychology.

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We present a short historical review of the major figures and institutions that contributed to make Paris a renowned centre of physiology and neurology during the xixth and the first half of the xxth century. We purposely chose to focus on the period 1800-1950, as 1800 corresponds to the actual beginning of experimental physiology of the nervous system - what is here referred to as "neuroscience"-and 1950 marks its exponential rise. Our presentation is divided into four chapters, matching the main disciplines which have progressed and contributed the most to the knowledge we have of the brain sciences: anatomy, physiology, neurology, and psychiatry-psychology.

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We present a short historical review on the major institutions and figures that contributed to make Paris a renowned centre of physiology and neurology during the xixth and the first half of the xxth centuries. We purposely chose to focus on the period 1800-1950, as 1800 corresponds to the development of brain science and 1950 marks the true beginning of neuroscience. Our presentation is divided into four chapters, matching the main disciplines which have progressed and contributed the most to the knowledge we have of the brain sciences: anatomy, physiology, neurology, and psychiatry-psychology.

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This review addresses the history since antiquity of studies on the anatomical and functional relations between nerves and muscles, and the progressive use of newer approaches to this topic. By the Hippocratic era (almost 2500 years ago) the digestive, circulatory and nervous systems were thought to participate in the production of animal spirits. This concept had strong support for nervous conduction, even after the dawn of electrophysiology in the late 18th C.

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This article addresses the emergence of the "motoneuron concept," i.e., the idea that this cell had properties of particular advantage for its control of muscle activation.

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Article Synopsis
  • Important concepts around breathing, walking, and chewing were developed in the 19th century, laying the groundwork for biomechanics.
  • Major studies by experts focused on measuring movement and understanding the physiology of locomotion and respiration, revealing crucial motor structures through the analysis of motor pathologies.
  • Research into reflexes highlighted key pathways between sensory receptors and motor outputs, demonstrating how early pioneers tackled significant issues in controlling these rhythmic motor behaviors using basic investigative methods.
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