Showing papers by "Tunis University published in 2022"

Optoelectronics properties of Janus SnSSe monolayer for solar cells applications

Abstract: Highly demanding efficiency, scaling and cost led the researchers to predict and synthesize two-dimensional transition metal dichalcogenides for advanced technology. Using the first-principles calculations, we study the optoelectronic properties, and device absorption efficiency of Janus SnSSe monolayer. The Janus SnSSe exist in two different phases, 1T and 2H structures. We find the 1T structure dynamically more stable than the 2H structure due lower energy and no-negative frequencies in the phonon spectra. The 1T SnSSe possess semiconductiing nature with an indirect bande-gap of 1.61 eV. The Janus SnSSe possesses a strong absorption having sharp absorption edges, showing the transition of electron to the conduction band from the valence band. We find that the Janus SnSSe strongly absorb light below 4.0 eV, which show its prominent applications for solar cell. A strong absorption from infra-red to the ultra-violet region of light spectrum make it promising in the optical devices. Furthermore, the wider band gap nature having strong device absorption-efficiency could make it suitable for the top cell in the tandem architecture.

Using extended Kalman filter for failure detection and prognostic of degradation process in feedback control system

Abstract: In this article, we study a new approach to predict failures in feedback control system and particularly in actuators. However, we use two-tank control system with a proportional–integral–derivativ...

The synovial fluid fibroblast-like synoviocyte: A long-neglected piece in the puzzle of rheumatoid arthritis pathogenesis

Abstract: Rheumatoid arthritis (RA) is a systemic autoimmune disease during which fibroblast-like synoviocytes (FLS) contribute to both joint inflammation and destruction. FLS represent the core component of the synovial membrane. Following inflammation of this membrane, an effusion of cell-rich synovial fluid (SF) fills the joint cavity. Unlikely, SF has been shown to contain fibroblasts with some shared phenotypic traits with the synovial membrane FLS. These cells are called SF-FLS and their origin is still unclear. They are either brought into the synovium via migration through blood vessels, or they could originate within the synovium and exist in projections of the synovial membrane. SF-FLS function and phenotype are poorly documented compared to recently well-characterized synovial membrane FLS subsets. Furthermore, no study has yet reported a SF-FLS single-cell profiling analysis. This review will discuss the origin and cellular characteristics of SF-FLS in patients with RA. In addition, recent advances on the involvement of SF-FLS in the pathogenesis of RA will be summarized. Current knowledge on possible relationships between SF-FLS and other types of fibroblasts, including synovial membrane FLS, circulating fibrocytes, and pre- inflammatory mesenchymal (PRIME) cells will also be addressed. Finally, recent therapeutic strategies employed to specifically target SF-FLS in RA will be discussed.

Ordinary and Extraordinary Complex Refractive Indices Extraction of a Mylar Film by Transmission Spectrophotometry

Abstract: A new spectrophotometric technique for the determination of both ordinary and extraordinary complex refractive indices (CRIs) of a stretched polyethylene terephthalate (Mylar) film is proposed. The sample was placed between two identical polarizers, and the transmission spectra of two different configurations (incident polarization parallel and perpendicular to the Mylar film optical axis) were recorded. Ordinary and extraordinary complex refractive indices are then extracted by fitting the experimental spectra with a theoretical model that we had elaborated in advance. A new formula for transmittance dispersion, based on the Fresnel's coefficients formalism and using the Cauchy model, was derived to describe n and κ wavelength dependence. The suggested theoretical model succeeded in reproducing the Mylar transmission spectra across the entire visible spectral range (400, 750 nm) for both configurations, and the retrieved dispersion curves of the refractive indices, extinction coefficients, and the birefringence are comparable to results found in the literature. The proposed method is fast, straightforward, easy to set up, and cost-effective. It proved to be an excellent alternative to more conventional methods such as spectroscopic ellipsometry.

Traffic Disturbance Mining and Feedforward Neural Network to Enhance the Immune Network Control Performance

Abstract: Traffic disturbance in urban cities challenges the most advanced traffic signal control systems (TSCS). The challenge is mainly related to the capability of TSCS to ensure a quick detection and to suggest suitable decisions. Neural network has shown great potential in predicting traffic disturbance. In addition, smart clustering could be beneficial to ensure fast disturbance reaction while TSCS are providing control decisions. Moreover, the immune network approach has succeeded in controlling interrupted intersections. Motivated by these assumptions, we propose in this paper a disturbance mining approach based on the occurrence of traffic disturbances to ensure optimal signals control that minimizes traffic delay. Initially, the queue delay is calculated based on mutual information of different traffic scenarios. At that point, within the maximum traffic delay constraint, the feedforward neural network is considered to find the optimal traffic delay and maximize traffic fluidity. As a result, disturbances and related control decisions are clustered based on the calculated traffic delay. Our approach helped the immune network control system (INCS) by prompting it with faster reaction and lower traffic delay compared to its classical version.

The relationship of 3′UTR <i>HLA‐G14‐bp insertion/deletion</i> and <i>+3142 C/G</i> polymorphisms and soluble HLA‐G expression with gynecological cancers: An updated meta‐analysis

Abstract: Human leukocyte antigen-G (HLA-G) is implicated in several cancers and is considered to be an immune checkpoint regulator. We determined the association between polymorphisms in the 3' untranslated region of HLA-G and soluble HLA-G (sHLA-G) expression with gynecological cancers (GCs).A meta-analysis was conducted to examine the association between HLA-G14-bp insertion (I)/deletion (D) and +3142C/G polymorphism in GC and to evaluate sHLA-G expression RESULTS: We revealed a significant association between the +3142C/G polymorphism and invasive cervical cancer (ICC) based on the allelic model G versus C (odds ratio [OR] = 0.738, 95% confidence interval [CI] = 0.563-0.966, p = 0.027), dominant GG+GC versus CC (OR = 0.584, 95% CI = 0.395-0.862, p = 0.007), and codominant GG versus CC (OR = 0.527, 95% CI = 0.312-0.891, p = 0.017) models, suggesting that the G allele and GG genotype are protective against ICC. In gynecological precancerous patients with human papillomavirus (HPV) infection, we found that the 14-bp I/D under the codominant DD versus DI model (OR = 0.492, 95% CI = 0.241-1.004, p = 0.051) was of borderline significance. Soluble HLA-G levels were significantly higher in patients compared with healthy controls (standardized mean differences [SMD] = 1.434, 95% CI = 0.442-2.526, p = 0.005). Stratification by cancer type revealed that the sHLA-G levels were significantly increased in cervical cancer (SMD = 4.889, 95% CI = 0.468-9.310, p = 0.030) and in subjects of Asian ethnicity (SMD = 4.889, 95% CI = 0.467-9.309, p = 0.030).HLA-G14-bp I/D and +3142 C/G polymorphisms are associated with GC and HPV-associated cervical cancer. In addition, we found significantly increased sHLA-G levels in cancer patients. These results provide a basis for further studies in diagnostics and immunotherapy of GC.

Antimicrobial activity and safety features assessment of <i>Weissella</i> spp. from environmental sources

Abstract: Weissella strains have been reported to be useful in biotechnological and probiotic determinations, and some of them are considered opportunistic pathogens. Given the widespread interest about antimicrobial susceptibilities, transmission of resistances, and virulence factors, there is little research available on such topics for Weissella. The aim of this study was to assess the safety aspects and antimicrobial potential of 54 Weissella spp. strains from different environmental sources. Antibiotic susceptibility, hemolytic activity, horizontal transfer, and antibacterial activity were studied, as well as the detection of biogenic amine BA production on decarboxylase medium and PCR was performed. All the strains were nonhemolytic and sensitive to chloramphenicol and ampicillin. Several strains were classified as resistant to fusidic acid, and very low resistance rates were detected to ciprofloxacin, tetracycline, streptomycin, lincomycin, erythromycin, and rifampicin, although all strains had intrinsic resistance to vancomycin, nalidixic acid, kanamycin, and teicoplanin. Two BA-producing strains (W. halotolerans FAS30 and FAS29) exhibited tyrosine decarboxylase activity, and just one W. confusa FS077 produced both tyramine and histamine, and their genetic determinants were identified. Ornithine decarboxylase/odc gene was found in 16 of the Weissella strains, although 3 of them synthesize putrescine. Interestingly, eight strains with good properties displayed antibacterial activity. Conjugation frequencies of erythromycin from Bacillus to Weissella spp. varied in the average of 3 × 10-9 transconjugants/recipient. However, no tetracycline-resistant transconjugant was obtained with Enterococcus faecalis JH2-2 as recipient. The obtained results support the safe status of Weissella strains, derived from environmental sources, when used as probiotics in animal feed.

Role of Apolipoprotein E in the Clinical Profile of Atypical Parkinsonian Syndromes

Abstract: Atypical Parkinsonian syndromes (APS) encompass a spectrum of neurodegenerative diseases including dementia with Lewy bodies (DLB), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal syndrome (CBS). The effects of the Apolipoprotein E (APOE) gene on APS clinical features are controversial and understudied in several populations. We aimed to explore the influence of APOE genotype on clinical features in an APS Tunisian cohort.We included clinically diagnosed APS patients genotyped for APOE, and analyzed the clinical and APOE genotype associations.A total of 328 APS patients were included, comprising 184 DLB, 58 PSP, 49 MSA, and 37 CBS. Significant differences in initial Mini-Mental State Examination and Frontal Assessment Battery scores according to APOE genotypes (P=0.05 and 0.0048) were found. Executive dysfunction (P=0.026) disorientation (P=0.025), and hallucinations (P<0.001) were more pronounced among APOE-ɛ4 carriers particularly in DLB. Memory disorders were also correlated to APOE-ɛ4 allele (P=0.048) and were more frequent among DLB and PSP carriers. Depression was associated to APOE-ε4 (P=0.042), more markedly in APOE-ε4-CBS and MSA carriers.Our findings suggested a role of APOE-ε4 in defining a more altered cognitive phenotype with variable degrees across subgroups in APS patients, especially in DLB carriers. This effect mainly concerned executive, memory and orientation functions as well as hallucinations.