67 research outputs found

    Investigation and Design of Different Antennas in Solar Cells' Environments with Their Needed Tools

    Get PDF
    With the spread use of solar cells as a renewable energy source and the wide use of wireless communications, it is interesting to use the solar cell panels as an energy source for rural wireless communications for security and safety. For compactness, it is proposed to embed antennas in the solar cell panels. Therefore, it is proposed to investigate the antenna characteristics within this environment. As such, the characteristics of the solar cells in the radio frequency region should be studied for proper design of the antennas in such an environment. Therefore, a rigorous design approach for antennas in the solar cells' environment is proposed through this work. A practical model of the solar cells in the microwave frequency range is presented using anisotropic surface impedance boundaries. Two different surface impedance measurement setups are exploited to accurately model solar cells. Moreover, measurements of antennas' radiation efficiency are invoked in this work using the Wheeler cap concept in a contactless fashion to perform measurements within solar cells' environments. A novel measurement technique has been proposed extending conventional Wheeler cap capabilities to measure wide band antennas. The technique promotes a straightforward processing procedure and convenient measurement setup. In addition, a simple, fast, and efficient numerical solution for the electromagnetic scattering arbitrary problems is proposed. Based on the uniqueness theorem and the use of novel equivalent problems with Random Auxiliary Sources (\emph{RAS}), more degrees of freedom are added resulting in significantly faster solutions. The proposed technique is expected to provide a significant reduction in the execution time and memory requirements compared to the surface equivalent based Method of Moments (MoM) as the inherent properties of this procedure are used. Various verification and result cases are presented to assess the introduced technique, which is incorporated into different analysis and design problems in this work. Moreover, the RAS method is extended to model antennas in their radiating and scattering modes, which, in turns, is adopted in the reflectarray antenna analysis and design procedures. The introduced solar cells models along with the developed computations and measurement tools are used to develop a design procedure for antennas suited for the solar cells environment. An optically transparent reflectarray antenna integrated with solar cells is proposed as an application of interest that suits satellite communication purposes. Material choice, feed antenna tailored design and rigorous design procedures are presented to enhance the achievable performance of the antenna/solar cells integrated device

    In Vivo Positional Analysis of Implantable Collamer Lens Using Ultrasound Biomicroscopy

    Get PDF
    Purpose. To evaluate the anterior segment, the anatomical position of the implantable collamer lenses (ICL), and its relationship to adjacent ocular structures using Ultrasound Biomicroscopy (UBM). Methods. In a prospective study, 142 myopic eyes of 93 patients implanted with Visian ICL were subjected to UBM examination between March 2010 and January 2015. The relative position of ICL to the adjacent structure and the overall iris configuration were evaluated. The machine calibers were used to measure the minimum central distance between the ICL and anterior lens capsule (vault) and the vertical central distance between the corneal endothelium and the ICL (E-ICL). Results. The mean ICL vault was 376±105 μm. The mean E-ICL was 2826±331 μm. Contact between ICL and the posterior epithelium of the iris was present in all eyes. The overall iris configuration was flat in 89 eyes. Central anterior convexity was present in 41 eyes and mild peripheral iris bombe in 12 eyes. The haptics could be imaged in the ciliary sulcus in 112 eyes and at least one haptic resting on the lens periphery and zonules in 30 eyes. Conclusion. UBM can provide valuable anatomical information that allows detailed postoperative in vivo assessment of ICL

    Genetic relationships and isozyme profile of dermatophytes and Candida strains from Egypt and Libya

    Get PDF
    Three molecular techniques random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and restriction fragment length polymorphism (RFLP) were employed for identification and to study the genetic relationship among six species of dermatophytes and three species of yeasts isolated from Egyptian and Libyan patients with skin mycosis. Each species was represented by two isolates, one from Egyptian patients and the second from Libyan. RAPD in which four random 10-mer primers and two ISSR primers were used to amplify the DNA fragments of target fungi and RFLP in which two universal primers (ITS1 and ITS4) were used to amplify the internal transcribed spacer (ITS) regions of the ribosomal (rRNA) gene in fungal isolates followed by digestion with HinfI and HaeIII endonucleases was carried out. Three molecular marker techniques showed considerable potential for identifying and discriminating dermatophytes and Candida species and the achieved results confirmed identification based on conventional morphological methods. Results of RAPD and ISSR markers revealed 78.7% genetic similarity (GS) between Microsporum canis and other tested fungi reflecting a relatively longer genetic distance from other isolates of dermatophytes and yeasts. Candida krusei and Candida tropicalis were closely related showing 93.3% GS. C. albicans showed 90.9% similarity with other species of Candida. Epidermophyton floccosum was easily separated from all Trichophyton species showing 87.3% similarity. Unique bands were displayed by certain fungi and can be taken as a positive marker for isolate identification and discrimination. RFLP technique revealed differences in the number (1 to 5) and size (8 to 378 base pairs) of DNA fragments depending on the fungal isolate and restriction enzyme used. Within each fungal species, different isolates of dermatophytes and Candida from Egypt and Libya showed close relationship. Seven isozyme systems namely esterase, peroxidase, malate dehydrogenase, acid phosphatase, glutamate-oxalo-acetate transaminase, Urease and protease were studied to detect the gene expression and genetic variability among the different isolates of dermatophytes and Candida.Keywords: Random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR), restriction fragment length polymorphism (RFLP), dermatophytes, Candida, isozymesAfrican Journal of Biotechnology Vol. 12(29), pp. 4554-456

    Modeling and Design Empirical Formulas of Microstrip Ridge Gap Waveguide

    Get PDF

    Hybrid thermosensitive-mucoadhesive 'in situ' forming gels for enhanced corneal wound healing effect of L-carnosine

    Get PDF
    PURPOSE: Thermosensitive in situ gels have been around for decades but only a few have been translated into ophthalmic pharmaceuticals. The aim of this study was to combine the thermo-gelling polymer poloxamer 407 and mucoadhesive polymers chitosan (CS) and methyl cellulose (MC) for developing effective and long-acting ophthalmic delivery systems for L-carnosine (a natural dipeptide drug) for corneal wound healing. METHODS: The effect of different polymer combinations on parameters like gelation time and temperature, rheological properties, texture, spreading coefficients, mucoadhesion, conjunctival irritation potential, in vitro release, and ex vivo permeation were studied. Healing of corneal epithelium ulcers was investigated in a rabbit’s eye model. RESULTS: Both gelation time and temperature were significantly dependent on the concentrations of poloxamer 407 and additive polymers (chitosan and methyl cellulose), where it ranged from <10 s to several minutes. Mechanical properties investigated through texture analysis (hardness, adhesiveness, and cohesiveness) were dependent on composition. Promising spreading-ability, mucoadhesion, transcorneal permeation of L-carnosine, high ocular tolerability, and enhanced corneal epithelium wound healing were recorded for poloxamer 407/chitosan systems. CONCLUSION: In situ gelling systems comprising combinations of poloxamer-chitosan exhibited superior gelation time and temperature, mucoadhesion, and rheological characteristics suitable for effective long-acting drug delivery systems for corneal wounds

    Anti-prostate cancer metabolites from the soil-derived Aspergillus neoniveus

    Get PDF
    Prostate cancer (PCa) ranks as one of the most commonly diagnosed malignancies worldwide. Toxicity, lack of clinical efficacy, and development of resistance phenotypes are the main challenges in the control of prostate malignancies. Notably, castration-resistance prostate cancer (CRPCa) is a highly aggressive and metastatic phenotype of the disease with a poor prognosis and very limited therapeutic options. Herein, we report the isolation and genotypic identification of a soil-derived fungus Aspergillus neoniveus using the PCR-based internal transcribed spacer (ITS) region amplification approach. HPLC/MS investigation of the metabolic profile of the ethyl acetate extract from the fungal biomass revealed tentative identification of forty-five compounds belonging to various chemical classes including γ-butyrolactones, alkaloids, phenolics, and quinoids. Furthermore, the chromatographic purification of microbial extract enabled the identification of nervonic acid methyl ester (1) for the first time from endophytic fungi, as well as acetyl aszonalenin (2), and butyrolactone II (3) for the first time from A. neoniveus. The chemical frameworks of the isolated compounds were identified via extensive spectral analysis including 1 and 2D NMR and MS. The X-ray crystal structure and absolute configuration of acetyl aszonalenin (2) were also determined. Additionally, screening of in vitro anticancer activity of the fungal extract revealed its potential antiproliferative and anti-migratory activities against five different prostate cancer cells (PC3, PC-3M, DU-145, CWR-R1ca, and 22Rv1), including different cells with the castration-resistance phenotype. Moreover, the isolated metabolites significantly inhibited the proliferation, migration, and colonization of human prostate cancer cells at low micromolar levels, thus providing credence for future investigation of these metabolites in relevant anti-prostate cancer animal models. Furthermore, computational target prediction tools identified the cannabinoid G-protein coupled receptors type 1 (CB1) as a potential biological target mediating, at least in part, the anticancer effects of acetylaszonalenin (2). Moreover, molecular modeling and docking studies revealed a favorable binding pose at the CB1 receptor orthosteric ligand pocket aided by multiple polar and hydrophobic interactions with critical amino acids. In conclusion, the Aspergillus neoniveus-derived prenylated indole alkaloid acetylaszonalenin has promising anticancer activity and is amenable to further hit-to-lead optimization for the control of prostate malignancies via modulating CB1 receptor

    Appraisal on the Wound Healing Potential of Deverra tortuosa DC. and Deverra triradiata Hochst Essential Oil Nanoemulsion Topical Preparation

    Get PDF
    Deverra tortuosa (Desf.) DC. and Deverra. triradiata Hochst. ex Bioss are perennial desert shrubs widely used traditionally for many purposes and they are characteristic for their essential oil. The objective of the present study was to investigate the in vivo wound healing activity of the essential oil (EO) of D. tortuosa and D. triradiata through their encapsulation into nanoemulsion. EO nanoemulsion was prepared using an aqueous phase titration method, and nanoemulsion zones were identified through the construction of phase diagrams. The EO was prepared by hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and supercritical fluid extraction (SFE) and analyzed using GC/MS. D. tortuosa oil is rich in the non-oxygenated compound, representing 74.54, 73.02, and 41.19% in HD, MADH, and SFE, respectively, and sabinene represents the major monoterpene hydrocarbons. Moreover, D. triradiata is rich in oxygenated compounds being 69.77, 52.87, and 61.69% in HD, MADH, and SFE, respectively, with elemicin and myristicin as major phenylpropanoids. Topical application of the nanoemulsion of D. tortuosa and D. triradiata (1% or 2%) exhibited nearly 100% wound contraction and complete healing at day 16. Moreover, they exhibit significant antioxidant and anti-inflammatory effects and a significant increase in growth factors and hydroxyproline levels. Histopathological examination exhibited complete re-epithelialization accompanied by activated hair follicles and abundant collagen fibers, especially at a concentration of 2%. Therefore, the incorporation of the two Deverra species into nanoemulsion could professionally endorse different stages of wound healing

    K-variant BCHE and pesticide exposure: Gene-environment interactions in a case-control study of Parkinson's disease in Egypt

    Get PDF
    Pesticide exposure is associated with increased risk of Parkinson's disease (PD). We investigated in Egypt whether common variants in genes involved in pesticide detoxification or transport might modify the risk of PD evoked by pesticide exposure. We recruited 416 PD patients and 445 controls. Information on environmental factors was collected by questionnaire-based structured interviews. Candidate single-nucleotide polymorphisms (SNPs) in 15 pesticide-related genes were genotyped. We analyzed the influence of environmental factors and SNPs as well as the interaction of pesticide exposure and SNPs on the risk of PD. The risk of PD was reduced by coffee consumption [OR = 0.63, 95% CI: 0.43-0.90, P = 0.013] and increased by pesticide exposure [OR = 7.09, 95% CI: 1.12-44.01, P = 0.036]. The SNP rs1126680 in the butyrylcholinesterase gene BCHE reduced the risk of PD irrespective of pesticide exposure [OR = 0.38, 95% CI: 0.20-0.70, P = 0.002]. The SNP rs1803274, defining K-variant BCHE, interacted significantly with pesticide exposure (P = 0.007) and increased the risk of PD only in pesticide-exposed individuals [OR = 2.49, 95% CI: 1.50-4.19, P = 0.0005]. The K-variant BCHE reduces serum activity of butyrylcholinesterase, a known bioscavenger for pesticides. Individuals with K-variant BCHE appear to have an increased risk for PD when exposed to pesticides

    Role of diffusion weighted magnetic resonance imaging DW-MRI in choice of the surgical approach for pituitary macroadenoma resection

    No full text
    Background and purpose: Consistency of pituitary macroadenoma is a crucial information for neurosurgeons. We aimed to assess the role of DW-MRI as non invasive imaging modality in predicting the tumour consistency of pituitary macroadenoma. Materials and methods: Twenty patients with pituitary macroadenoma underwent conventional MR imaging sequences, pre contrast, post contrast MRI and diffusion weighted MRI with ADC map. The tumour consistency was determined both macroscopic by neurosurgeons and microscopic by histopathologists. Results: Our study included 12 soft, 4 intermediate and 4 hard tumours. The tumour consistency and the collagen contents were correlated with diffusion and ADC values. The mean ADC value of patients with soft tumours was 0.54 × 10−3 mm2/s while for intermediate tumour was 0.82 × 10−3 mm2/s and for hard tumours was 1.11 × 10−3 mm2/s. Soft and intermediate consistency tumours were successfully managed by endoscopic transsphenoidal approach; suction and curettage. While, hard tumours could not be managed by the transsphenoidal approach and needed further transcranial procedure with sensitivity 95% and specificity 95%. Conclusion: DWI-MRI is a useful tool to predict the pituitary macroadenoma consistency and the suitable surgical approach for resection

    Model-Driven Engineering Tools and Languages for Cyber-Physical Systems-A Systematic Literature Review

    No full text
    Kardas, Geylani/0000-0001-6975-305XWOS:000637166600001The development of Cyber-physical Systems (CPS) draws more interest from both researchers and industrial practitioners considering the opportunities they offer in almost all areas of industry. However, the engineering and management of CPS are challenging tasks due to their inherent heterogeneity and complexity characteristics. Regarding the development of CPS, there currently exists no standard methodology owing to the complexity of the domain. One of the key approaches to reduce the development complexity for CPS is Model-driven Engineering (MDE), which is frequently used in many industrial domains for software development to increase the level of platform abstraction. Nevertheless, it is always almost challenging, especially for the new researchers in this field, to determine the appropriate tools and languages to perform a particular MDE activity during CPS development. To the best of our knowledge, there is no guideline that demonstrates which language(s)/tool(s) to use for the various MDE techniques/phases for the development of CPS. This paper presents a Systematic Literature Review (SLR) study that focuses on identifying and classifying the recent research practices pertaining to CPS development by applying MDE approaches. With the objective of providing a general overview of the field, the study evaluates 140 research papers published during 2010-2018. Accordingly, a precise view of the various MDE tools and languages used in the development life-cycle of CPS, addressed MDE techniques/activities, and targeted CPS components is presented. We believe that the conducted study will guide researchers and practitioners to identify appropriate tools and languages according to the system requirements. It may also help in getting an overall understanding of the research trends for further research and development on the MDE of CPS.Turkish Government for Turkiye Scholarships (YTB) Program; COST Action: Multi-Paradigm Modeling for Cyber-Physical Systems (MPM4CPS) [IC1404]; EU Framework Programme Horizon 2020Mustafa Abshir Mohamed would like to thank Turkish Government for Turkiye Scholarships (YTB) Program. Moharram Challenger and Geylani Kardas would also like to thank the European Cooperation in Science & Technology COST Action networking mechanisms and support of COST Action IC1404: Multi-Paradigm Modeling for Cyber-Physical Systems (MPM4CPS). COST was supported by the EU Framework Programme Horizon 2020
    • …
    corecore