50 research outputs found

    Phase Space Topology and Bifurcation of Liouville Torii in the Goryatchev-Tchaplygin Top

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    The classical problem of a rigid body with a fixed point is considered in the case of Goryatchev-Tchaplygin. We give a complete description of its real phase space topology. All generic bifurcation of Liouville Torii is determined theoretically and numerically. We give also explicit periodic solutions of the problem.The classical problem of a rigid body with a fixed point is considered in the case of Goryatchev-Tchaplygin. We give a complete description of its real phase space topology. All generic bifurcation of Liouville Torii is determined theoretically and numerically. We give also explicit periodic solutions of the problem

    CANCER DU COL, DYSPLASIE, DYSPLASIE SEVERE, MICRO INVASION : CARACTERISTIQUE DE LA PRISE EN CHARGE PENDANT la grossesse ?

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    Approximately 30% of cervical cancers occur in women of childbearing age. In early pregnancy , it is now recommended that a new cervical cytology if the previous rise to 2 years or more , or in the absence of regular monitoring. The methods of conventional cytology smears or said liquid medium are easily achievable. Pregnancy makes available the junction area and changes of pregnancy do not reduce the diagnostic value of smears after informing the cytologist. During pregnancy colposcopy examination remains essential to assess the cytological abnormalities . If the smear shows a high-grade lesion , an ASC- H, or low - grade and ASC-US or glandular atypia (AGC) colposcopy and directed biopsy is performed. Rates dysplasia found is of course variable but to behave similarly. The aim of our work is referred to the particularities of the association of cervical cancer and pregnancy in different diagnostic and therapeutic steps.Environ 30 % des cancers du col surviennent chez des femmes en âge de procréer. En début de grossesse, il est actuellement recommandé de réaliser une nouvelle cytologie cervicale si la précédente remonte à 2 ans ou plus, ou en l’absence de suivi régulier. Les méthodes de cytologie conventionnelle dite de Papanicolaou ou en milieu liquide sont facilement réalisables. La grossesse rend accessible la zone de jonction et les modifications gravidiques ne diminuent pas la valeur diagnostique du frottis après information du cytologiste. Pendant la grossesse la colposcopie demeure l’examen indispensable pour évaluer les anomalies cytologiques. Si le frottis montre une lésion de haut grade, une ASC-H, ou de bas-grade et ASC-US ou une atypie glandulaire (AGC) on réalise une colposcopie et biopsie dirigée .Le taux de dysplasie retrouvé est bien sûr variable mais la conduite à tenir est similaire. Le but de notre travail est d’évoqué les particularités liées à l’association cancer du col et grossesse aux différentes étapes diagnostiques et thérapeutiques

    Quantification of ciprofloxacin in pharmaceutical products from various brands using FT-NIR: A comparative investigation of PLS and MCR-ALS.

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    peer reviewedThis study aims to quantify ciprofloxacin in commercial tablets with varying excipient compositions using Fourier Transform Near-Infrared Spectroscopy (FT-NIR) and chemometric models: Partial Least Squares (PLS) and Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS). Matrix variation, arising from differences in excipient compositions among the tablets, can impact quantification accuracy. We discuss this phenomenon, emphasizing potential issues introduced by varying certain excipients and its importance in reliable ciprofloxacin quantification. We evaluated the performance of PLS and MCR-ALS models independently on two sets of tablets, each containing the same drug substance but different excipients. The statistical results revealed promising results with PLS prediction error of 0.38% w/w of the first set and 0.47% w/w of the second set, while MCR-ALS achieved prediction errors of 0.67% w/w of the first set and 1.76% w/w of the second set. To address the challenge of matrix variation, we developed single models for PLS and MCR-ALS using a dataset combining both first and second sets. The PLS single model demonstrated a prediction error of 4.3% w/w and a relative error of 6.41% w/w, while the MCR-ALS single model showed a prediction error of 1.88% w/w and a relative error of 1.29% w/w. We then assessed the performance of the single PLS and MCR-ALS models developed based on the combination of the first and the second set in quantifying ciprofloxacin in various commercial tablet brands containing new excipients. The PLS model achieved a prediction error ranging between 6.2% w/w and 8.39% w/w, with relative errors varied between 8.53% w/w and 12.82% w/w. On the other hand, the MCR-ALS model had a prediction error between 1.11% w/w and 2.66% w/w, and the relative errors ranging from 0.8% to 1.74% w/w

    Prise en charge du couple mère enfant de la varicelle pendant la grossesse

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    La varicelle est une maladie généralement bénigne chez l’enfant, cependant l’atteinte de l’adulte est potentiellement grave et son association à la grossesse expose la mère et le nouveau né à des risques de complications plus redoutables.La prise en charge multidisciplinaire associant obstétricien, biologiste et pédiatre est indispensable pour limiter les effets délétères de l’infection par la varicelle pendant la grossesse.Nous rapportons dans cet article les approches thérapeutiques actuellement proposées pour la prise en charge anté et péripartum du couple mère-enfant en cas d’infection par la varicelle pendant la grossesse et nous proposons des conduites visant à atténuer les complications maternelles

    Pharmacological and chemical properties of some marine echinoderms

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    Echinoderms have attracted the attention of scientists over the past few years after identifying a variety of unique structures endowed by interesting biological properties. However, the Moroccan coast biodiversity is still uninvestigated. In our ongoing attempts to valorize the rich Moroccan marine environment, this study aimed at assessing the antimicrobial activity of extracts obtained from three echinoderms Astropecten irregularis, Luidia sarsi and Ophiura albida against the human pathogens: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Bacillus subtilis. Moreover, their antioxidant activities were tested using standard methods in addition to the antidiabetic activity which has been evaluated in vitro against α-amylase and α-glucosidase enzymes. HPLC-DAD-QTOF-MS analysis revealed a significant content of some phenolic compounds such as pyrogallol, gallic, sinapic, ferulic, p-hydroxybenzoic and salicylic acids whose existence can be related to the endophytic fungi and/or dietary intake whereas GC-MS analysis exhibited diverse chemical structures such as cholesterol, oleic acid and glycerol 1-palmitate

    Current application of advancing spectroscopy techniques in food analysis:data handling with chemometric approaches

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    Abstract In today’s era of increased food consumption, consumers have become more demanding in terms of safety and the quality of products they consume. As a result, food authorities are closely monitoring the food industry to ensure that products meet the required standards of quality. The analysis of food properties encompasses various aspects, including chemical and physical descriptions, sensory assessments, authenticity, traceability, processing, crop production, storage conditions, and microbial and contaminant levels. Traditionally, the analysis of food properties has relied on conventional analytical techniques. However, these methods often involve destructive processes, which are laborious, time-consuming, expensive, and environmentally harmful. In contrast, advanced spectroscopic techniques offer a promising alternative. Spectroscopic methods such as hyperspectral and multispectral imaging, NMR, Raman, IR, UV, visible, fluorescence, and X-ray-based methods provide rapid, non-destructive, cost-effective, and environmentally friendly means of food analysis. Nevertheless, interpreting spectroscopy data, whether in the form of signals (fingerprints) or images, can be complex without the assistance of statistical and innovative chemometric approaches. These approaches involve various steps such as pre-processing, exploratory analysis, variable selection, regression, classification, and data integration. They are essential for extracting relevant information and effectively handling the complexity of spectroscopic data. This review aims to address, discuss, and examine recent studies on advanced spectroscopic techniques and chemometric tools in the context of food product applications and analysis trends. Furthermore, it focuses on the practical aspects of spectral data handling, model construction, data interpretation, and the general utilization of statistical and chemometric methods for both qualitative and quantitative analysis. By exploring the advancements in spectroscopic techniques and their integration with chemometric tools, this review provides valuable insights into the potential applications and future directions of these analytical approaches in the food industry. It emphasizes the importance of efficient data handling, model development, and practical implementation of statistical and chemometric methods in the field of food analysis

    Biochar promotes nitrogen transformation and tomato yield by regulating nitrogen-related microorganisms in tomato cultivation soil

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    Abstract Nitrogen (N) transformation in soil directly determines the effectiveness of N for plant growth. Biochar has received evermore attention because of its significant ability to improve soil. However, the effects of biochar on N-related microorganisms (Lycopersicon esculentum Mill.) in tomato cultivation soil, N transformation, utilisation of water and N fertiliser, and tomato yield remain unclear. The objective of this study was to investigate the responses of N-related microorganisms to biochar and N fertilisation in soil, along with the implications of biochar for altering N transformation, N uptake by tomatoes, and utilisation of water and N fertiliser. A two-year greenhouse experiment containing six biochar levels under drip irrigation (0, 10, 30, 50, 70, and 90 t ha⁻¹) and two N fertiliser application rates (190 and 250 kg ha⁻¹) was conducted in the northwest of China. The results showed that adding biochar significantly promoted urease activity, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and the number of amoA-type nitrifiers in the soil. The MBC:N ratio and the number of nirS-type denitrifiers were significantly inhibited when the added amount of biochar was greater than or equal to 30 t ha⁻¹. Moreover, biochar can increase the water content in the soil and can reduce the N lost to leaching. The inorganic N (NO₃⁻ and NH₄⁺) in the soil could be better maintained in the rootzone and better absorbed by tomato plants when adding 30, 50, and 70 t ha⁻¹ of biochar. The amount of N fertiliser could be reduced by 24% without a significant loss of tomato yield when the amount of biochar added was over 30 t ha⁻¹. It was indicated that the yield of tomatoes and the net profits were quadratically related to the application rate of biochar. In the test area, 53 t ha⁻¹ of biochar with 190 kg ha⁻¹ of N and 44.6 t ha⁻¹ of biochar with 190 kg ha⁻¹ of N were calculated to be the best amounts from the perspectives of tomato yield and net profit, respectively. Thus, biochar promotes N transformation by regulating N-related microorganisms; hence, it increases the inorganic N in the roots of the plants, reduces N lost to leaching, and significantly promotes the N absorption of tomatoes. The results in this research are of great significance for the development of management strategies for tomato maintenance, environmental protection, and resource conservation

    Multi-way analysis coupled with near-infrared spectroscopy in food industry:models and applications

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    Abstract Near-infrared spectroscopy (NIRS) is a fast and powerful analytical tool in the food industry. As an advanced chemometrics tool, multi-way analysis shows great potential for solving a wide range of food problems and analyzing complex spectroscopic data. This paper describes the representative multi-way models which were used for analyzing NIRS data, as well as the advances, advantages and limitations of different multi-way models. The applications of multi-way analysis in NIRS for the food industry in terms of food process control, quality evaluation and fraud, identification and classification, prediction and quantification, and image analysis are also reviewed. It is evident from this report that multi-way analysis is presently an attractive tool for modeling complex NIRS data in the food industry while its full potential is far from reached. The combination of multi-way analysis with NIRS will be a promising practice for turning food data information into operational knowledge, conducting reliable food analyses and improving our understanding about food systems and food processes. To the best of our knowledge, this is the first paper that systematically reports the advances on models and applications of multi-way analysis in NIRS for the food industry
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