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1.
Mouna Hamouda Insaf Handous Nasr Ben Dhia Samia Ayachi Ahmed Letaief Sabra Aloui Ammeur Frih Habib Skhiri Habib Khochtali Mezri Elmay 《Hemodialysis international. International Symposium on Home Hemodialysis》2012,16(4):497-503
Brown tumors (BTs) are relatively uncommon but they are serious complications of renal osteodystrophy. The objective of this study was to analyze the clinical, biological, and radiological characteristics of 16 patients with BTs provoked by secondary hyperparathyroidism (sHPT) and its response to the decrease in parathyroid hormone levels after parathyroidectomy (PTX). The management of that uncommon condition was also reviewed. We conducted a retrospective study including 16 end‐stage renal disease patients who underwent subtotal PTX between 1997 and 2007 for severe sHPT with BTs. Our study included 10 men and 6 women, whose average age was 34 years. All patients were on dialysis. Ten of them were on dialysis for more than 5 years. The median duration on dialysis was 84 months. Patients included suffered from swellings associated with functional limitations. BTs had multiple locations in 7 patients. Jaw was the most frequent location (62%). Radiography and tomodensitometry demonstrated a mixed radio lucent and radio‐opaque lesions with an expansion of the cortical bone. Bone scan demonstrated an increased uptake of lesions. Chirurgical treatment was indicated in all cases because of severe refractory sHPT with functional limitations and/or disfiguring deformities. In all cases, BTs stopped its progression and even decreased in size. However, it was insufficient in four cases, which required a surgical resection. PTX remains an efficacious approach in resistant cases of sHPT with persistent BTs. 相似文献
2.
Alexandre Vivet Bessem Ben Doudou Christophe Poilâne Jun Chen M’Hamed Ayachi 《Journal of Materials Science》2011,46(5):1322-1327
This article proposes an alternative way to use carbon nanotubes to improve the performance of carbon fibre-reinforced composites.
A chemical process, based on esterification of surface groups, is used to anchor nanotubes onto carbon fibre surface. Anchored
nanotubes form a network surrounding the carbon fibres. After CNT anchoring, the tow is impregnated with an epoxy resin and
tensile tests are performed on this minicomposite sample. By enhancing matrix properties and fibre/matrix interface, the CNT
network has a significant influence on the composite strength. 相似文献
3.
Hernandez Gustavo Castillo Yasseri Mohammad Ayachi Sahar de Boor Johannes Müller Eckhard 《Semiconductors》2019,53(13):1831-1837
Semiconductors - Thermoelectric material development typically aims at maximizing produced electrical power and efficiency of energy conversion, even though sometimes, this means adding expensive... 相似文献
4.
Ayachi Mohsen 《Analog Integrated Circuits and Signal Processing》2003,36(3):199-206
This paper describes a new transimpedance amplifier for fast current pulses delivered by high energy particle detectors. The choice of a bipolar technology allowed a 100 low input impedance and a rise time down to 1 nS. The fully differential current mode architecture provides an excellent linearity and a large versatility as for its transimpedance, bandwidth and power consumption. 相似文献
5.
Ahmed Chabane Fatiha Bouchal Mohamed Hentabli Nabila Ayachi Houssam Eddine Slama Farouk Rezgui Lydia Hammoumraoui 《加拿大化工杂志》2023,101(8):4446-4459
Candesartan is an angiotensin receptor blocker (ARB) used to treat hypertension. However, its poor aqueous solubility and oral bioavailability have limited its therapeutic applications. In order to increase bioavailability and control the release of candesartan condensation, microspheres containing biodegradable polymers (polyvinylpyrrolidone [PVP K30] and polylactic acid [PLA]) in different ratios were prepared by the o/o solvent evaporation method using Span 80 as a surfactant. In addition, the impact of encapsulation parameters (i.e., PVP K30 and PLA concentrations) on the encapsulation ratio and release percentage was investigated by the mixed factorial design method. The release kinetics of the microspheres was simulated by combining two methods, the Dragonfly algorithm and a support vector machine (DA-SVM). The experimental data were in good agreement with the predicted data, with a coefficient of determination close to unity and a mean square error close to zero. Fourier-transfer infrared spectrometry (FTIR) analysis revealed the presence of condensation in all formulations without reporting distortion in the spectra. Scanning electron microscopy (SEM) confirmed the successful synthesis of microspheres, whose sizes were between 12 and 26 μm. Formulations with a PLA-drug ratio of 6:1 (N15, N17, and N18) showed the highest encapsulation efficiency (68%, 71%, and 70%, respectively), while formulations that do contain PVP K30, such as N5, N4, and N3, showed a higher release (83%, 84%, and 89%, respectively), indicating that the agent (PVP K30) enhanced the bioavailability and release of candesartan. Overall, N3 showed a higher drug release rate at 12 h and important encapsulation efficiency, making it the optimal formulation obtained in this study. 相似文献
6.
I. Tarchoun N. Nasri H. Mahmoudi M. Zaghdoudi H. Ghaith B. Marzouk Mouhiba Ben Nasri‐Ayachi M. Lachaâl 《Journal of food science》2012,77(10):C1047-C1054
Abstract: Variation in the composition of Origanum majorana L. essential oil (EO) and fatty acids were studied under salt treatment. Plant material has been harvested at 2 phenological stages: early vegetative stage (EVS) and late vegetative stage (LVS) or prefloral. Our results showed that the application of 75 mM NaCl increased total lipid contents in marjoram shoots and caused great qualitative changes in the fatty acids profiles. NaCl treatment reduced and stimulated the EO yields, respectively, at EVS and LVS and induced quantitative changes in the chemical EO composition in shoots. Phenolic contents were higher during the LVS than EVS in the absence and the presence of salt. Under control conditions, RP‐HPLC analysis of the methanolic extract of marjoram dried shoots showed a predominance of flavonoid during the EVS whereas phenolic acids predominated during the LVS. However, under 75 mM NaCl, we noted a predominance of flavonoid at LVS and constant levels of phenolic and flavonoid classes at the EVS. For control treatment and at both EVS and LVS, the main components identified were respectively rosmarinic acid gallic as phenolic acids and amentoflavone as flavonoid. In the presence of salt and at the EVS, we observed a significant increase in trans‐2 hydrocinnamic, gallic acid and quercetin‐3‐galactoside contents. However, for the LVS, salt induced a stimulation of gallic acid, apigenin, and amentoflavone. Our results showed that LVS had the highest contents of bioactive compounds, and could be considered as the best stage for harvesting marjoram plants. Practical Application: In this study, the fatty acid composition, essential oil, and phenolic content of Origanum majorana were investigated. This is important for potential application of marjoram as functional food at the late vegetative stage. The richness of O. majorana in volatile and phenolic active compounds known for their antioxidant, antimicrobial, and insecticidal activities could support the utilization of this plant in a large field of application including cosmetic, pharmaceutical, agro alimentary, and biological defense. 相似文献
7.
M. Chemek F. Massuyeau J. Wéry A. Hlel S. Ayachi E. Faulques S. Lefrant K. Alimi 《应用聚合物科学杂志》2012,125(1):126-132
Steady-state and time-resolved photoluminescence (TRPL) measurements are used in order to investigate the emission properties of new graft copolymer involving poly(N-vinylcarbazole) (PVK) and poly(3-methylthiophene) (PMeT) named PVK-3MeT. The photo-generated species in PVK-3MeT are identified as singlet intrachain excitons. Furthermore, radiative and nonradiative lifetimes have been calculated. The observed changes in the photo-physical properties of the different condensed phases could be directly related to the nanostructure of the material. The use of PVK in the chemical synthesis allows the obtaining of a new organic material with better emission and slowly radiative recombination compared to those of polythiophenes indicating that the radiative channel is more enhanced. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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9.
Mourad Chemek Sahbi Ayachi Abdelkader Hlel Jany Wéry Serge Lefrant Kamel Alimi 《应用聚合物科学杂志》2011,122(4):2391-2402
In this article, we present quantum chemical calculations, based on density functional theory (DFT), performed to investigate the geometries and the opto‐electronic properties of a new synthesized graft copolymer based on poly(N‐vinylcarbazole) (PVK) and poly(3‐methylthiophene) (PMeT) named PVK‐3MeT. First, we have theoretically computed and compared the structural, optical, and vibrational parameters of both neutral and doped states. In addition, the excited state was theoretically obtained by the ab initio RCIS/STO‐3G method. To assign the absorption and emission peaks observed experimentally, we computed the energies of the lowest singlet excited state with the time‐dependent density functional theory (TD‐DFT) method. Electronic parameters such as the HOMO‐LUMO band gap, the ionization potential (IP), and electron affinity (EA) are extracted. Calculations show that the PVK‐3MeT copolymer is nonplanar in its ground neutral state. Meanwhile, upon doping or photoexcitation, an enhancement of the planarity is observed, resulting on a decrease of the inter‐ring torsion angle between 3‐methylthiophene units. Such modifications in the geometric parameters induce a dramatic change on the HOMO and LUMO orbitals in the doped or excited states. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011. 相似文献
10.
Mohsen Ayachi Jean-Philippe Blondé Lingchuan Zhou Francis Braun 《Analog Integrated Circuits and Signal Processing》2007,52(1-2):37-46
This paper describes two novel fully integrated circuits implemented in standard 0.35 μm CMOS technology dedicated to ECG signal measurement. Many specific problems related to this kind of signal are discussed. Pertinent solutions, such as high pass filtering, offset cancellation, common mode rejection, low pass filtering and capacitive coupling between different stages are proposed. 相似文献