Monitoring changes in edema-associated intracranial pressure that complicates trauma or surgery would lead to improved outcomes. Implantable pressure sensors have been explored, but these sensors ...require post-surgical removal, leading to the risk of injury to brain tissue. The use of biodegradable implantable sensors would help to eliminate this risk. Here, we demonstrate a bioactive glass (BaG)-based hydration sensor. Fluorine (CaF
) containing BaG (BaG-F) was produced by adding 5, 10 or 20 wt.% of CaF
to a BaG matrix using a melting manufacturing technique. The structure, morphology and electrical properties of the resulting constructs were evaluated to understand the physical and electrical behaviors of this BaG-based sensor. Synthesis process for the production of the BaG-F-based sensor was validated by assessing the structural and electrical properties. The structure was observed to be amorphous and dense, the porosity decreased and grain size increased with increasing CaF
content in the BaG matrix. We demonstrated that this BaG-F chemical composition is highly sensitive to hydration, and that the electrical sensitivity (resistive-capacitive) is induced by hydration and reversed by dehydration. These properties make BaG-F suitable for use as a humidity sensor to monitor brain edema and, consequently, provide an alert for increased intracranial pressure.
Bioactive glasses are indicated for use as bone substitutes in orthopedic or dental surgery because of their high reactivity once in contact with the biological medium. Boron is known as a glass ...network former and an activator of the glasses bioactivity. In this work, bioactive glass was doped by 5, 10 and 20 wt% of B
2
O
3
according to the melting process. Adding boron oxide with high content enhances glass materials’ bioactivity. Likewise, thanks to their solubility, borate-containing bioactive glasses were fluently used as orthopedic implants. The aim of our study was to investigate of boron effect on the thermal characteristics of our bioactive glass to better understand their proprieties in order for use as bone biomaterial. The obtained results proved that the more the boron content in the glass network increases, the more the melting temperature decreases and the more the thermal stability increases.
Derived Hench bioactive glass (BaG) containing boron (B) is explored in this work as it plays an important role in bone development and regeneration. B was also found to enhance BaG dissociation. ...However, it is only possible to incorporate a limited amount of B. To increase the amount of B in BaG, bioactive borosilicate glasses (BaG-B
) were fabricated based on the use of the solution-gelation process (sol-gel). In this work, a high B content (20 wt.%) in BaG, respecting the conditions of bioactivity and biodegradability required by Hench, was achieved for the first time. The capability of BaG-B
to form an apatite phase was assessed in vitro by immersion in simulated body fluid (SBF). Then, the chemical structure and the morphological changes in the fabricated BaG-B
(x = 0, 5, 10 and 20) were studied. The formation of hydroxyapatite (HAp) layer was observed with X-ray diffraction (XRD) and infrared (IR) spectroscopy. The presence of HAp layer was confirmed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Enhanced bioactivity and chemical stability of BaG-B
were evaluated with an ion exchange study based on Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and energy dispersive spectroscopy (EDS). Results indicate that by increasing the concentration of B in BaG-Bx, the crystallization rate and the quality of the newly formed HAp layer on BaG-B
surfaces can be improved. The presence of B also leads to enhanced degradation of BaGs in SBF. Accordingly, BAG-B
can be used for bone regeneration, especially in children, because of its faster degradation as compared to B-free glass.
Fluoride (F) is important for enhancing illogical activity of bioceramics. To increase fluoride content of derived Hench bioactive glass (BaG), bioactive fluorosilicate glasses (BaG-Fx) were ...synthesized by using melting method and characterized using different physico-chemical analyses. Fluoride-containing BaGs were synthesized at a temperature of 1350°C. Structural and thermal effect of calcium fluoride (CaF2) insertion into the glass network in the BaG: SiO2–CaO–Na2O–P2O5 quaternary system was studied. Indeed, the incorporated amounts of fluorine (CaF2) (from 5% to 20% by mass) induced significant physico-chemical changes. Through the structural study by X-ray diffraction (XRD), the amorphous character of our fluorosilicate glasses is proven. Infrared (IR) spectroscopy proved the incorporation of fluorine into the glass matrix. In the microstructural framework, we revealed the morphological changes of the glass powders as a function of the CaF2 content. These results were confirmed by Brunauer, Emmett and Teller (BET) measurements. Through Differential Scanning Calorimetry (DSC) thermal analysis we established the impact of fluoride ions on the structural dynamics and thermodynamic properties of these newly developed bioactive glasses. Accordingly, it was possible for the first time to incorporate as much as 20 wt% of CaF2 in BaG respecting the conditions of bioactivity and biodegradability required by Hench. After detailed analyses of the transformation entropies of BG-Fx as a function of the added CaF2 content, it can be stated that the intermolecular movements within the fluorosilicate network are more limited as a function of the added CaF2 amount. This slows down the ion exchange phenomena and subsequently the dissociation of the material in vitro, which can be anticipated to occur after implantation in vivo.
Ce travail de thèse porte sur le développement des nouveaux verres bioactifs de comblement osseux. Ils sont élaborés par fusion dans le système quaternaire : SiO2-CaO-Na2O-P2O5. Deux éléments ...chimiques (bore et fluor), ont été incorporés au sein du réseau vitreux. L’effet de la quantité des éléments ajoutés dans le verre, sur le comportement physico-chimique, mécanique et physiologique a été mené par plusieurs techniques originales. L’intégration du bore ou du fluor au sein de la matrice vitreuse, influe sur les caractéristiques thermiques des verres synthétisés. Les performances mécaniques en termes de résistance mécanique, module de Young, module de cisaillement, rigidité et dureté ont été développé par l’incorporation du fluor dans la structure vitreuse. L’effet inverse a été manifesté pour les verres à base du bore. Des essais ''in vitro'' ont prouvé que la présence du bore accélère la dissolution de la matrice vitreuse, la cinétique et la cristallisation de la couche d’hydroxyapatite. Tandis que l’ajout du fluor retarde ces phénomènes physiologiques.
This thesis focuses on the development of new bioactive glasses for use as bone filling. They are synthetized by the melting method in the quaternary system CaO-SiO2-Na2O-P2O5. Two chemical elements (boron and fluor), have been incorporated in the glass network. The amount added effect, of elements, in the glass, on the physico-chemical, mechanical and physiological behaviour was led by several original techniques. The boron or fluor integration in the glass matrix, affect the thermal characteristics of the synthesized glasses. The mechanical performance in terms of: mechanical strength, Young's modulus, shear modulus, rigidity and hardness, have been developed by the fluor incorporation into the glass structure. The opposite effect was manifested for boron based glasses. In vitro tests have showed that the boron presence accelerates the vitreous matrix dissolution, the kinetics and the crystallization of the hydroxyapatite layer. While the fluor addition retards these physiological phenomena.
Repellent efficacy of 10% EBAAP (3-N-butyl-N-acetyl-aminopropionic acid, ethyl ester) and 10% Icaridin ((2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester)) were evaluated against ...20% DEET (N,N-diethyl-3-methylbenzamide) in human subject trials against ticks. Responses of host-seeking nymphs of the European castor bean tick (Ixodes ricinus L.; Acari: Ixodidae) and the North American blacklegged tick (I. scapularis Say; Acari: Ixodidae) were compared. Tests were carried out according to the US-EPA standard protocol with ethanolic solutions of the active ingredients of repellents being applied to the forearm of 10 volunteers. The upward movement of ticks was monitored until repellent failure taking up to 12.5 h. Application of 20% DEET resulted in median complete protection times (CPT; Kaplan-Meier median) between 4 and 4.5 h, while 10% EBAAP yielded CPTs of 3.5-4h. No significant differences were found between the efficacies of two repellents nor between the two species tested. The median of the CPT of a 10% Icaridin solution was 5h in nymphs of I. scapularis, but 8h in those of I. ricinus (P<0.01). Based on these studies, EBAAP and Icaridin are efficacious alternatives to DEET in their repellent activity against nymphs of the two Ixodes ticks with Icaridin demonstrating particularly promising results against I. ricinus. Future research should investigate whether similar results occur when adult Ixodes ticks or other tick species are tested.
Classically, cognitive impairment (CI) was not considered as a paramount feature of multiple system atrophy(MSA) in both parkinsonian(MSA-P) and cerebellar(MSA-C) motor-subtypes. Yet, growing ...evidence indicates currently the commonness of such deficits among MSA patients in different populations. Our aim was to evaluate the cognitive profile of MSA Tunisian patients and to analyze the underlying clinical and genetic determinants.
In a retrospective cross-sectional study, clinically-diagnosed MSA patients were included. All subjects underwent clinical and neuropsychological assessments to characterize their cognitive profile. The associations with their APOE genotype status were analyzed. Determinant of CI were specified.
We included 71 MSA patients. Female gender(sex-ratio = 0.65) and MSA-P subtype(73%) were predominant. Mean age of disease onset was 59.1years. CI was found in 85.7% of patients(dementia in 12.7% and Mild cognitive impairment(MCI) in 73% of patients mainly of multiple-domain amnestic type(37.3%)). Mean MMSE score was lower among MSA-P compared to MSA-C(23.52 vs. 26.47;p = 0.027). Higher postural instability gait disorder(PIGD) and MDS-UPDRS-III scores were noted in demented MSA patients(p = 0.019;p = 0.015 respectively). The main altered cognitive domain was attention(64.8%). Executive functions and mood disorders were more affected in MSA-P(p = 0.029,p = 0.035 respectively). Clinical and neurophysiological study of dysautonomia revealed no differences across cognitive subtypes. APOE genotyping was performed in 51 MSA patients with available blood samples. Those carrying APOEε4 had 1.32 fold higher risk to develop CI, with lower MMSE score(p = 0.0001). Attention and language were significantly altered by adjusting the p value to APOEɛ4 carriers(p = 0.046 and p = 0.044 respectively). Executive dysfunction was more pronounced among MSA-PAPOEε4 carriers(p = 0.010).
In this study, the main determinants of CI in Tunisian MSA patients were MSA-P motor-subtype, mainly of PIGD-phenotype, disease duration and APOEε4 carrying status, defining a more altered cognitive phenotype. This effect mainly concerned executive, attention and language functions, all found to be more impaired in APOEε4 carriers with variable degrees across MSA motor-subtypes.
With the spectacular development of pervasive computing and the widespread use of mobile technologies, the user usually resorts to a wide variety of user platforms. Moreover, the applications ...deployed on such platforms usually lack specific support for people suffering from disabilities. This is especially valid in the Tunisian context where the current status of digital accessibility is far from being perfect since the developer's community still ignores accessibility-related programming techniques. Consequently, further efforts are still required to resolve the issues related to the growing variety of available devices and of accessibility difficulties met by different categories of users.
Therefore, in this paper we are introducing a model driven approach that aims to assist local and worldwide communities of developers throughout the development process of accessible user interfaces (UIs) targeting several emerging platforms. Based on a set of models from different abstraction levels followed by transformations, this approach provides a generic framework that integrates accessibility concerns starting from the design time. It allows the generation of accessible interfaces with a focus on the graphical and adaptation aspects on various platforms regardless of the developer expertise in UI accessibility.1
•Improving the development of accessible applications for developers worldwide.•Metamodels of accessible user interface, interaction platforms, execution platforms.•Transformations from abstract accessible UI models to executable UIs.•Development of model editors to assist users create required models.•Evaluation of the framework to show the usability and efficiency of the approach.
Background
A wide range of neurological manifestations has been described in COVID-19.
Methods
In this nationwide retrospective observational study, patients in Tunisia diagnosed with COVID-19 ...between the 2nd of March and the 16th of May 2020 were contacted by telephone. We collected demographic and clinical data and specified characteristics and evolution of main neurological symptoms.
Results
Of 1034 confirmed COVID-19 patients, 646 were included (mean age 42.17 years old) and 466 (72.1%) had neurological symptoms. Neurological symptoms were isolated 22.7% (
n
= 106). Headache was the most frequent neurological symptom (
n
= 279, 41.1%): mainly frontotemporal (
n
= 143, 51.1%) and mild or moderate (
n
= 165, 59.1%). When associated with fever (
n
= 143, 51.3%), headache was more likely to be severe and present at onset. Recovery was reported in 83.2%. Smell and taste impairment were found in 37.9% (
n
= 245) and 36.8% (
n
= 238) respectively. Among them, 65.3% (156/239) were anosmic and 63.2% (146/231) were ageusic. A complete improvement was found in 72.1% (174/240) of smell impairment and in 76.8% (179/233) of taste impairment. Myalgia (
n
= 241, 37.3%) and sleep disturbances (
n
= 241, 37.3%) were also frequent. Imported cases had more neurological symptoms (
p
= 0.001). In 14.5%, neurological symptoms preceded the respiratory signs (RS). RS were associated with more frequent (
p
= 0.006) and numerous (
p
< 0.001) neurological symptoms.
Conclusions
Neurological symptoms in COVID-19 are frequent, can be isolated and present at onset. A total recovery is the most recorded outcome. RS are predictive of neurological symptoms. Studies in to virus and host genetics should be considered to understand the different phenotypes.
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