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الملخص: اهداف البحث: يدرس هذه البحث مضادات الأكسدة، ونشاط مضادات الميكروبات والتركيب الكيميائي للزيت الأساسي الذي تم عزله من الأجزاء الهوائية لحمض أورانتيفوليا. طرق البحث: تم جمع الأوراق الطازجة لحمض أورانتيفوليا من مزارع محلية في مدينة صور (المنطقة الشرقية) لسلطنة عمان خلال الفترة من يونيو- يوليو، ٢٠١٥. استخدمت طريقة التقطير المائي لعزل الزيت الأساسي. واستخدم الغاز اللوني- قياس الطيف الكتلي للتعرف ولتحديد كمية المكونات الكيمائية في الزيت. استخدمت طريقة الجرف الحرة للجذور في – المختبر لتحديد نشاط مضادات الأكسدة للزيت الذي تم عزله من أوراق الليمون، بينما تم تقييم النشاط المضاد للجراثيم ضد البكتيريا إيجابية الغرام والبكتيريا سلبية الغرام بطريقة انتشار القرص. النتائج: تم تحديد ما مجموعة ثلاثة وثلاثين مركبا كيميائيا وتم العثور على د- ليمونين (٦٣.٣٥٪) ليكون المكون الأساسي. تم تحديد مكونات رئيسة أخرى بنسب مختلفة. كما أظهر الزيت الأساسي لحمض أورانتيفوليا نشاطا ممتازا مضادا للجراثيم ضد المكورات العنقودية الذهبية ونشاط متوسطا ضد السلالات الإشريكية القولونية. وأظهر الزيت كذلك نشاطا واعدا لمضادات الأكسدة في المختبر ولكنه أظهر نشاطا مضادا للجراثيم متوسطا. الاستنتاجات: يتميز الزيت الأساسي لأوراق الليمون العماني بمحتوى عالي من د- ليمونين الذي يجعله مفيدا في الغذاء، والصناعات الدوائية والعطور. Abstract: Objectives: This study investigated the chemical composition and the antioxidant and antimicrobial activities of the essential oil isolated from the aerial parts of Citrus aurantifolia L. Methods: Fresh Citrus aurantifolia L. leaves were collected from farms in Sur city, located in the Al-Sharqia (Eastern) region of the Sultanate of Oman, during June–July of 2015. The essential oil was isolated using hydrodistillation. Gas chromatography–mass spectrometry (GC–MS) was used to identify and quantify the chemical constituents of the oil. An in-vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method was used to determine the antioxidant activity of the isolated oil from the lime leaves while a disc diffusion method was used to evaluate the antibacterial activity against Gram-negative and Gram-positive bacteria. Results: Thirty-three chemical compounds were identified, with d-limonene (63.35%) forming the major constituent. Other prominent constituents include 3,7-dimethyl-2,6-octadien-1-ol (7.07%), geraniol (6.23%), E-citral (4.35%), Z-citral (3.29%), and β-ocimene (2.25%). The essential oil of Citrus aurantifolia L. leaves showed excellent antibacterial activity against Staphylococcus aureus and moderate activity against pathogenic Escherichia coli strains. The oil exhibited promising in-vitro antioxidant activity (IC50 value = 21.57 μg/mL) but showed moderate antibacterial activities. Conclusions: The essential oil from Omani lime leaves is characterized by a high d-limonene content, making it useful for food, pharmaceutical, and perfumery industries. الكلمات المفتاحية: النشاط المضاد للجراثيم, حمض أورانتيفوليا, الزيت الأساسي, د- ليمونين, Keywords: Antibacterial activity, Citrus aurantifolia, d-limonene, Essential oil, GC–MS

Induction of regulatory intestinal responses to oral antigens prevents the subsequent development of systemic T-helper type-1 ([T.sub.H]1) responses to those antigens, a phenomenon referred to as oral tolerance (2). An [...], Under physiological conditions the gut-associated lymphoid tissues not only prevent the induction of a local inflammatory immune response, but also induce systemic tolerance to fed antigens (1,2). A notable exception is coeliac disease, where genetically susceptible individuals expressing human leukocyte antigen (HLA) HLA-DQ2 or HLA-DQ8 molecules develop inflammatory T-cell and antibody responses against dietary gluten, a protein present in wheat (3). The mechanisms underlying this dysregulated mucosal immune response to a soluble antigen have not been identified. Retinoic acid, a metabolite of vitamin A, has been shown to have a critical role in the induction of intestinal regulatory responses (4-6). Here we find in mice that in conjunction with IL-15, a cytokine greatly upregulated in the gut of coeliac disease patients (3,7), retinoic acid rapidly activates dendritic cells to induce JNK (also known as MAPK8) phosphorylation and release the proinflammatory cytokines IL-12p70 and IL-23. As a result, in a stressed intestinal environment, retinoic acid acted as an adjuvant that promoted rather than prevented inflammatory cellular and humoral responses to fed antigen. Altogether, these findings reveal an unexpected role for retinoic acid and IL-15 in the abrogation of tolerance to dietary antigens.

This work focusing on the collection and preparation of necessary data for hydrological modeling of High Sebou watershedupstream of the dam Allal El Fassi. It describes a methodology for combining space technologies, including geographical information systems (GIS), remote sensing and digital terrain models (DTM), with hydrological models with a view to prepare for a spatial hydrologic modeling whose used for flood forecasting. The methodology for conducting this study comes in several parts: The collection and processing of geographic data constituted the first part of this project. This approach is, in the beginning, to automatic extraction of sub-basins and drainage network, then the formatting of data for the mapping of the basin and finally, the preparation of the land use and soil for the development of a map of Curve Number (CN).

Background: Adult refractory sprue is a poorly defined disorder. We did a multicentre national study of patients with refractory sprue to characterise their clinical and pathological profile and outcome, and to assess the frequency and prognostic significance of phenotypic and molecular abnormalities in the intraepithelial T-cell population.Methods: Patients with severe symptomatic villous atrophy mimicking coeliac disease but refractory to a strict gluten-free diet, and with no initial evidence of overt lymphoma, were diagnosed at gastrointestinal referral centres between 1974 and 1998. Fixed and/or frozen duodenojejunal biopsy samples were reanalysed and immunostained with CD3 and CD8 monoclonal antibodies to find out the phenotype of intraepithelial lymphocytes (IEL). TCRgamma gene rearrangements were assessed on frozen biopsy samples by multiplex fluorescent PCR.Findings: There were 21 patients with refractory sprue and 20 controls with coeliacs disease. 16 (84%) of 19 assessed patients had an aberrant intraepithelial lymphoid intestinal population expressing intracytoplasmic CD3 but not surface CD8. Clonal intestinal TCRgamma gene rearrangements were found in 13 (76%) of 17 patients assessed; four (out of 12 assessed) had clonal dissemination to the blood. The 16 patients with an aberrant phenotype all had uncontrolled malabsorption; three subsequently developed overt T-cell lymphoma, and eight died. The three (16%) patients without aberrant clonal IEL made a complete clinical and histological recovery with steroid therapy plus a gluten-free diet.Interpretation: An immunophenotypically aberrant clonal intraepithelial T-cell population (similar to that of most cases of enteropathy-associated T-cell lymphoma) can be found in up to 75% of patients with refractory coeliac sprue; its identification by simple diagnostic techniques represents a marker of poor outcome (including occurrence of overt T-cell lymphoma). We suggest that refractory sprue associated with an aberrant clonal IEL may be the missing link between coeliac disease and T-cell lymphoma and may be classified as cryptic enteropathy-associated T-cell lymphoma. [ABSTRACT FROM AUTHOR]