Cloning of the Vanilloid-like Receptor VR-L and investigation of its interaction with members of the transient receptor potential family of receptors

Early pharmacological studies (Szolcsanyi and Jancso-Gabor, 1975, Wood, 1988) showed that capsaicin, the pungent ingredient of chilli peppers and other vanilloids, can specifically stimulate the C unmyelinated fibres which transmit nociceptive information i.e. information about noxious thermal, chemical and mechanical stimuli. The specific action of capsaicin on this subset of sensory neurons led researchers to postulate the existence of a capsaicin receptor. Caterina et al (1997) cloned Vanilloid Receptor 1 (VR1) from dorsal root ganglia, where the somata of C fibres reside. VR1 responds to capsaicin, heat, protons and to the cannabinoid ligand, anandamide (Zygmunt et al., 1999). Discrepancies between the pharmacological profile of VR1 and native vanilloid responses fuelled research for the identification of other vanilloid receptors. In this thesis, the cloning of a new member of the vanilloid receptor family is described using bioinformatics tools. The novel receptor was named Vanilloid Receptor-like (VR-L) and was found to share 49% identity with VR1 and 20% with members of the Transient Receptor Potential (TRP) family. VR-L transcripts were identified in a wide range of tissues including the capsaicin insensitive dorsal root ganglia neurons. The expression of the channel in these neurons can be upregulated by Nerve Growth Factor, as it was established with semi-quantitative RT- PCR. Co-immunoprecipitation studies were carried out to investigate the possibility that VR-L interacts with VR1 and other members of the TRP family to regulate indirectly vanilloid and other responses. VR1 and VR-L were found to form homomultimers and also to interact with each other and with members of the TRP family. A VR-L stable cell line was generated to study the functional significance of the interactions identified

Changes in nasal resonance following septoplasty in adults: Acoustic and perceptual characteristics

<p><i>Objectives</i>. Patients undergoing surgery for a deviated nasal septum (septoplasty) often report that their voice sounds different or less hyponasal. However, such a relationship between septoplasty and vocal resonance remains without scientific evidence. The purpose of this work is to investigate whether nasal septal surgery has any effect on nasal resonance, both in terms of objective measurements and patient perception. <i>Methods</i>. The research carried out was a prospective case–control study. We recruited patients who underwent septoplasty (study group) and healthy volunteers (control group). We obtained voice recordings of the nasal consonant /m/ pre- and four weeks postoperatively and twice at similar time intervals in the control group. We investigated objective changes by means of acoustic analysis of the voice recordings and calculated the total amount of acoustic energy in different bandwidths on a wide-band spectrogram. We also utilized a questionnaire to explore patient perception. <i>Results</i>. A total of 34 participants entered the study. ANOVA testing revealed significant changes in average total acoustic energy, phlegm, and throat dryness postoperatively. Regarding patient perception, a considerable number of our patients felt that their voice had changed for the better upon direct questioning. However, statistical analysis of the questionnaire items related to nasality of voice did not show a significant change. <i>Conclusions</i>. In this study it has been demonstrated that surgical correction of septal deviation causes significant spectrographic changes. In particular it causes changes in the average total acoustic energy during the production of a nasal consonant. A considerable number of our patients reported change in their vocal resonance for the better. We recommend that patients be advised that their voice may sound different after surgery, or less hyponasal.</p

Investigating the Sensitivity of Fiber Bragg Grating to a Process Induced Gap during Vacuum Bag Consolidation in Thermoplastic Composite Laminates

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In-situ monitoring of the vacuum-bag-only consolidation process of CF/LM-PAEK composites with an embedded Fibre Bragg Grating sensor

International audienceWe present a novel method for in-situ monitoring of the vacuum-bag-only (VBO) consolidation process of CF/LM-PAEK thermoplastic composites using an embedded Fibre Bragg Grating (FBG) sensor. An FBG sensor is first employed to monitor transverse strain in the plane during composite manufacturing. The data obtained from the embedded sensor demonstrate its sensitivity to thermal transitions of the thermoplastic matrix, including glass transition, crystallisation and melting. The coefficient of thermal expansion (CTE) of the composite material is also estimated using the FBG, with results validated by dilatometric measurements. Second, the sensitivity of the embedded FBG to consolidation phenomena, particularly the establishment of intimate contact between adjacent layers is also investigated. FBG-based monitoring of two different laminate configurations, one with raw prepreg plies and the other with pre-crystallised prepreg plies, confirms the sensor’s effectiveness in detecting the onset of intimate contact at the glass transition temperature. These findings highlight the potential of FBG-based monitoring for optimising composites manufacturing and improving quality control of high-performance thermoplastic composites

Investigating the sensitivity of fiber bragg grating to process-induced gap in thermoplastic composite laminates

International audienceIn this paper, an experimental method is proposed to evaluate the sensitivity of an embedded FBG sensor to an artificially-induced gap during the consolidation process of a carbon fiber reinforced thermoplastic composite. In-situ monitoring during manufacturing cycle demonstrated that the presence of such defect does not affect the sensor's ability to capture the consolidation phenomena. The response of the FBG during the heating phase is characterized by a significant increase of its spectrum intensity, strongly linked to the bending of the sensor caused by the induced gap. These preliminary results tend to validate the use of an embedded FBG for the in-situ detection of a process-induced gap, similar to defects that commonly occur during Automated Fiber Placement manufacturing process

Suivi in-situ du processus de consolidation de composite thermoplastique hautes performances par fibre à réseau de Bragg

International audienceIn the present paper, a process monitoring by an embedded FBG sensor for the in-situ consolidation of a high-performance carbon/thermoplastic composite (LM-PAEK) was investigated. First, the distribution of thermoplastic matrix and carbon fibre in the prepreg was observed using an optical microscope and a profilometer. The main thermophysical properties of the thermoplastic matrix such as its glass transition, crystallisation and melting point temperatures were obtained by DSC measurements. Second, a temperature calibration of the FBG sensor close to 400 °C was carried out. A specific protocol for the integration of the FBG in the laminate and for the in-situ process monitoring up to 400 °C was then designed and set up. The analysis of the FBG response during and after manufacturing of the laminate provided information on the different phenomena occurring during the process such as matrix crystallisation as well as the Coefficient of Linear Thermal Expansion of the carbon/thermoplastic composite. The consolidation phenomena of the thermoplastic matrix were detected and information on melting and glass transition temperatures was provided and found similar to data collected during DSC testing. These preliminary results tend to validate the use of optical fibres for the manufacturing process monitoring of a high-performance carbon/thermoplastic composite.Dans le présent article, un processus suivi in-situ de consolidation par un capteur FBG intégré dans un composite carbone/thermoplastique haute performance (LM-PAEK) a été étudié. Tout d'abord, la distribution de la matrice thermoplastique et de la fibre de carbone dans le préimprégné a été observée à l'aide d'un microscope optique et d'un profilomètre. Les principales propriétés thermophysiques de la matrice thermoplastique telles que ses températures de transition vitreuse, de cristallisation et de point de fusion ont été obtenues par des mesures DSC. Dans un second temps,une calibration en température du capteur FBG proche de 400 °C a été effectuée. Un protocole spécifique pour l'intégration du FBG dans le stratifié et pour le suivi du procédé in-situ jusqu'à 400 °C a ensuite été conçu et mis en place. L'analyse de la réponse FBG pendant et après la fabrication du stratifié a fourni des informations sur les différents phénomènes se produisant au cours du processus tels que la cristallisation de la matrice ainsi que le coefficient de dilatation thermique linéaire du composite carbone/thermoplastique. Les phénomènes de consolidation de la matrice thermoplastique ont été détectés et des informations sur les températures de fusion et de transition vitreuse ont été fournies et trouvées similaires aux données recueillies lors des tests DSC. Ces résultats préliminaires tendent à valider l'utilisation des fibres optiques pour le suivi du processus de fabrication d'un composite carbone/thermoplastique hautes performances

Effects of experimentally-induced maternal hypothyroidism on crucial offspring rat brain enzyme activities

Hypothyroidism is known to exert significant structural and functional changes to the developing central nervous system, and can lead to the establishment of serious mental retardation and neurological problems. The aim of the present study was to shed more light on the effects of gestational and/or lactational maternal exposure to propylthiouracil-induced experimental hypothyroidism on crucial brain enzyme activities of Wistar rat offspring, at two time-points of their lives: at birth (day-1) and at 21 days of age (end of lactation). Under all studied experimental conditions, offspring brain acetylcholinesterase (AChE) activity was found to be significantly decreased due to maternal hypothyroidism, in contrast to the two studied adenosinetriphosphatase (Na(+),K(+)-ATPase and Mg(2+)-ATPase) activities that were only found to be significantly altered right after birth (increased and decreased, respectively, following an exposure to gestational maternal hypothyroidism) and were restored to control levels by the end of lactation. As our findings regarding the pattern of effects that maternal hypothyroidism has on the above-mentioned crucial offspring brain enzyme activities are compared to those reported in the literature, several differences are revealed that could be attributed to both the mode of the experimental simulation approach followed as well as to the time-frames examined. These findings could provide the basis for a debate on the need of a more consistent experimental approach to hypothyroidism during neurodevelopment as well as for a further evaluation of the herein presented and discussed neurochemical (and, ultimately, neurodevelopmental) effects of experimentally-induced maternal hypothyroidism, in a brain region-specific manner