Video Pulse Width Modulation for Optical Fiber Transmission

This thesis describes theoretically the feasibility of two pulse width modulation (PWM) systems for transmission through an optical fiber. The first part of this work is devoted to the electronics of the two PWM systems. A comparison of the performance of each system is carried out. This comparison takes into account spectra, harmonic distortion, bandwidth requirement, system complexity and output signal to noise ratio (SNR). A comparison of PWM SNR and PCM SNR in the presence of intersymbol interference (ISI) is made. The second part is devoted to the optical system. The choice of optoelectronic devices, link losses, power budget, signal to noise ratio, and rise time budget are discussed

Impacto da dieta na redução do risco de cárie dentária: revisão narrativa

Uma dieta desequilibrada combinada com um estilo de vida mais sedentário, estão associados a muitas patologias, em particular à cárie dentária. No entanto, outros alimentos podem ter um efeito preventivo e curativo benéfico contra a desmineralização do esmalte e ao aparecimento de lesões cariosas, graças aos minerais, vitaminas e probióticos que contêm na sua composição. O médico dentista deve ter a capacidade de integrar a prevenção nutricional na prática da sua profissão. Para elaboração deste trabalho, foi realizada uma pesquisa bibliográfica nas bases de dados Pubmed, Google Scholar, Healthline, WHO Global Index Medicus no período compreendido entre Janeiro de 2007 e Dezembro de 2022, recorrendo às seguintes palavras chave: caries, demineralization, remineralization, micronutrients, macronutrients, vitamins, proteins, minerals, probiotics. Foram usados os operadores booleanos AND/OR, fazendo diferentes combinações com as palavras. Foram estabelecidos critérios de inclusão e de exclusão para a seleção dos artigos. Qual é o impacto da dieta na redução do risco de cárie dentária? A fim de responder a esta questão, esta revisão narrativa teve como objetivos, explicar o processo de aparecimento de cáries, assim como, estudar a importância da dieta, quais os principais alimentos e a sua composição em nutrientes que ajudam na redução do risco de aparecimento de lesões de cárie.An unbalanced diet combined with a more sedentary lifestyle are associated with many pathologies, in particular dental caries. However, other foods can have a beneficial preventive and curative effect against demineralisation of the enamel and the appearance of carious lesions, thanks to the minerals, vitamins, and probiotics they contain in their composition. The dentist must have the ability to integrate nutritional prevention in the practice of his profession. For the preparation of this work, a bibliographical search was conducted in the Pubmed, Google Scholar, Healthline, WHO Global Index Medicus databases in the period between November 2022 and February 2023, using the following keywords: caries, demineralization, remineralization, micronutrients, macronutrients, vitamins, proteins, minerals, probiotics. The Boolean operators AND/OR were used, making different combinations with the words. Inclusion and exclusion criteria were established for the selection of articles. What is the impact of diet on reducing the risk of dental caries? In order to answer this question, the objectives of this narrative review were to explain the process of appearance of caries, as well as to study the importance of diet, which are the main foods and their composition in nutrients that help to reduce the risk of appearance of caries lesions

Boolean Algebras of Projections on Banach Spaces

The object of this thesis is the study of the Boolean algebras of projections on Banach spaces and their properties. Chapter one is devoted to the study of the integration theory needed in the other chapters. The main characteristic features of the theory of normed KOthe spaces are introduced first. Next, we investigate the conditions on p which ensure that every function 0 6 L1(mu) can be factorized as &phis; = f.g, with f ∈ Lp and g ∈ Lp'. In chapter two, which is the main part of the thesis, we introduce the concept of Boolean algebras of projections. We prove that a Boolean algebra of projections is a-complete if and only if it is the range of a countably additive regular spectral measure. We show that a bounded Boolean algebra of projections on a weakly complete Banach space X can be embedded in a alpha-complete Boolean algebra of projections on X. Next, the main structure theorem for a cyclic Banach space X is proved. It is shown that the weakly closed algebra generated by a a-complete Boolean algebra of projections on a Banach space X is reflexive. A representation theorem for a complete Boolean algebra of projections is included. In chapter three, we consider the necessary and sufficient conditions for the restrictions of normal operators on Hilbert space to be normal operators, and the restrictions of scalar-type spectral operators on Banach spaces to be of scalar-type. The results of chapter one are due to T.A. Gillespie [13] and [14]. The majority of the results in chapter two are due to W.G. Bade [1] and [9], but we show how Gillespie's results can be used to obtain stronger results and give more satisfactory proofs of these results. The results of Chapter three are due to Wermer [18] and Dawson [5]

PHYTOCHEMICAL PROFILES, ANTIOXIDANT CAPACITY AND PROTECTIVE EFFECT AGAINST AAPH-INDUCED MOUSE ERYTHROCYTE DAMAGE BY DAPHNE GNIDIUM L. SHOOTS EXTRACTS

Objective: Various biological activities have been reported for Daphne gnidium, the aim of the present study was to determine polyphenols and some biological activities of extracts from the shoots of this plants.Methods: Phenolic and flavonoids contents of D. gnidium extracts (DGE) were determined by Folin-Ciocalteau and identified by HPLC–DAD/MS. Free radical scavenging and antioxidant potential of the crude (CE), chloroform (CHE) and ethyl acetate (EAE) extracts of D. gnidium shoots were investigated using several in vitro and ex vivo assays, including 2, 2-diphenyl-picrylhydrazyl radical scavenging, superoxide anion scavenging (by both enzymatic and nonenzymatic methods) and hydroxyl radical scavenging capacity methods. The antioxidant activity of the extracts was measured using the xanthine oxidase (XO) inhibitory activity, reducing power and ß-carotene-linoleic bleaching assays. Inhibition of lipid peroxidation and oxidative hemolysis were also performed to confirm the protective effect of these extracts.Results: It was found that values of phenolics varied between 130.84±5.99 and 137±7.66 mg gallic acid equivalent/g dry extract. HPLC analysis revealed the presence of cinnamic acid derivatives and other metabolites from the flavonoids family. All extracts exhibited a superoxide scavenging capacity. The EAE had the highest antioxidant activity as measured by DPPH radical and hydroxyl radical scavenging activity. The extracts showed an inhibitory effect on xanthine oxidase, the IC50 rangesfrom 0.021±0.001 to 0.061±0.001 mg/ml. The EAE showed also potent reducing power ability. CHE possess an inhibition ratio of (92.11%) in the linoleic acid oxidation assay close to that of BHT (96.77%). All extracts exhibited antioxidant activity in the linoleic acid emulsion system (3.87-61.11 %). Under the oxidative action of AAPH, EAE and CE showed higher protective effect against erythrocytes hemolysis than the CHE. The percentage of hemolysis (H%) determined for EAE and CE after 1 h of incubation were 0% and 1.9%, respectively.Conclusion: This study indicates that DGE contains relevant antioxidant compounds responsible, at least in part, for its antioxidant and radicals scavenging activity. Flavone derivatives were determined as the main active component of the shoots part and the CHE was the most active extract.Â

Intérêt de la gastrostomie percutanée endoscopique chez la personne âgée (à propos d'une étude rétrospective monocentrique de 68 cas)

MONTPELLIER-BU Médecine UPM (341722108) / SudocMONTPELLIER-BU Médecine (341722104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Phenolics Contents, Xanthine Oxidoreductase Inhibitory Potential, Antibacterial and Antioxidant Activities of Cachrys libanotis L. Root Extracts

To date, no studies have investigated the phytochemical screening and biological activities of Cachrys libanotis L. traditionally used for the treatment of gout and rheumatism. Therefore, we aimed to investigate, for the first time, the phytochemical contents, the xanthine oxidoreductase inhibition, antibacterial, and antioxidant activities of extracts derived from the roots of C. libanotis L. Roots were submitted to extraction and fractionation using three different solvents sequentially, in the ascending order of polarity. Subsequently, XOR was purified from bovine milk and its inhibition was evaluated using xanthine/XOR system. The antioxidant activities were assessed employed superoxide scavenging, β- carotene bleaching, DPPH scavenging, ferrous iron chelation and FRAP assays). The antibacterial activity was tested by disc diffusion assay against 11 ATCC strains. Extraction and fractionation gave crude extract (CrE), hexane extract (HxE), chloroform extract (ChE), ethyle acetate extract (EAE) and aqueous extract (AqE).  EAE exhibited the highest XOR inhibitory effect. CrE exhibited the highest effect as DPPH scavenger. All fractions exhibited a good activity against linoleate oxidation. Both CrE and AqE had an excellent chelating activity. Extracts showed a medium reducing power with greatest value exhibited by EAE. The plant extracts exhibited moderate to good antibacterial activity where the HxE extract had the strongest antimicrobial activity. From the obtained results, C. libanotis roots might be helpful in preventing or slowing the progress of gout, and it could be used as an additive in the food industry providing good protection against oxidative damage. Keywords: Cachrys libanotis, polyphenols, oxidative stress, xanthine-oxidoreductase (XOR), antimicrobial

Antioxidant and radical scavenging properties of Carthamus caeruleus L extracts grow wild in Algeria flora

Four sub-fractions of Carthamus caeruleus L (whichbelongs to the family Asteraceae) root extracts, i.e., methanol (CE), chloroform (CHE), ethyl acetate (EAE) and aqueous (AE) extracts were screened for their total phenolics, flavonoids and possible antioxidant activities, using DPPH free radical-scavenging and β-carotene/linoleic acid assays. The results indicated that total polyphenols were highest in EAE followed by CHE. However, the free radical scavenging activity of CHE was higher than the other extracts with an IC50 value of 53.26 µg/mL. Determination of quercetin, gallic acid and rutin showed antioxidant activity as positive controls in parallel experiments. Moreover, oxidation of linoleic acid was effectively inhibited by AE, EAE and CE which were too close to each other. Also, the CHE was more effective compared to the synthetic antioxidant BHT. It could be concluded that Carthamus caeruleus L growing wild in the Mediterranean regions and especially in Algeria has a potent antioxidant activity and could be evaluated as a starting point for further investigations.Four sub-fractions of Carthamus caeruleus L (which belongs to the family Asteraceae) root extracts,i.e., methanol (CE), chloroform (CHE), ethyl acetate (EAE) and aqueous (AE) extracts were screenedfor their total phenolics, flavonoids and possible antioxidant activities, using DPPH free radicalscavengingand β-carotene/linoleic acid assays. The results indicated that total polyphenols werehighest in EAE followed by CHE. However, the free radical scavenging activity of CHE was higherthan the other extracts with an IC50 value of 53.26 μg/mL. Determination of quercetin, gallic acid andrutin showed antioxidant activity as positive controls in parallel experiments. Moreover, oxidation oflinoleic acid was effectively inhibited by AE, EAE and CE which were too close to each other. Also,the CHE was more effective compared to the synthetic antioxidant BHT. It could be concluded thatCarthamus caeruleus L growing wild in the Mediterranean regions and especially in Algeria has apotent antioxidant activity and could be evaluated as a starting point for further investigations. Propriedades dos radicais antioxidantes extraídos de Carthamus caeruleus L nativosda flora da ArgéliaQuarto sub-frações extraídas da raiz de Carthamus caeruleus L (que pertencem à famíliaAsteraceae), i.e., metanol (CE), clorofórmio (CHE), acetato de etil (EAE) e extratos aquosos foramexaminados minuciosamente quanto aos seus fenólicos, flanóides e suas atividades antioxidantespossíveis, usando DPPH extração de radicais livres e B-caroteno/ácido linoléico. Os resultadosindicaram que os polifenóis totais foram maiores em EAE seguido de CHE. Entretanto, a atividadede extração de radicais livres em CHE foi maior que de outros extratos com um valor de IC50 de of5326 μg/mL. A determinação de quercetina ácido gálico e rutina demonstrou que a atividade deantioxidante funciona como controle positive em experimentos paralelos. Além disso, a oxidaçãode ácido lenoico foi efetivamente inibida por AE, EAE e CE que estavam muito próximos uns aosoutros. Também, o CHE foi mais eficaz se comparado ao antioxidante sintético BHT. Foi possívelconcluir que Carthamus caeruleus L nativos das nas regiões do Mediterrâneo, e, especialmente naArgélia, tem uma potente atividade antioxidante e poderia ser avaliada como o ponto de partidapara investigações futuras