461 research outputs found

    Numerical Solutions of Monic Chebyshev Polynomials on Large Scale Differentiation

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    Abstract In this paper, a new formula of the spectral differentiation matrices is presented. Therefore, the numerical solutions for higher-orde

    Dyed Grafted Poly(tetra fluoro ethylene-perfluoro vinyl ether) copolymer Film with Acrylic Acid for High-Dose Radiation Dosimetry

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    The grafted films of poly(tetra fluoro ethylene-perfluoro vinyl ether) copolymer film with acrylic acid ( PFA-g-PAAc) were prepared by ?-radiation. The films were allowed to react with an ionic dye, namely Brilliant Green (BG). The investigations show that these new dosimeter films of PFABG may be useful for high dose gamma radiation applications. The useful absorbed dose range of the dyed film extends up to about 400 kGy. The radiation-induced colour bleaching has been analyzed with visible spectrophotometery, either at the maximum of absorption band at 633 nm. The effects of relative humidity during irradiation, shelf-life and post-irradiation storage in dark and indirect daylight conditions on dosimeters performance are discussed. Key word: Brilliant Green/ Poly(tetra fluoro ethylene-perfluoro vinyl ether) copolymer/ Acrylic Acid/ Radiation Dosimetr

    Preparation of Low Molecular Weight Natural Polymers by gamma-Radiation and Their Growth Promoting Effect on Zea Maize Plants

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    Preparation of oligosaccharides from chitosan and Na-alginate were done using ?-rays and H2O2 as oxidizing agent. Structural and molecular weight changes of such oligosaccharides were determined by GPC, FT-IR and UV-Vis. spectroscopy. FT-IR and UV-Vis. studies revealed that during radiation degradation process, the main polysaccharide chain structure was almost remained. The effects of spraying 100 ppm of oligochitosan or oligoalginate or both of them with different ratios on the growth of zea maize plants showed an enhancement of plant growth performance and the productivity at the same time suggesting their possible use in agriculture purposes as growth promoters for plants

    Pre-harvest foliar application of mineral nutrients to retard chlorophyll degradation and preserve bio-active compounds in broccoli

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    Foliar application of micronutrients has become a common farm management practice to increase the overall yield of various crops. However, the effects of foliar fertilization on shelf life and postharvest quality of the crops are rather under-researched. The aim of this field experiment was to evaluate the effect of foliar application of individual mineral nutrients (calcium (Ca), zinc (Zn), manganese (Mn), and iron (Fe) on pre and postharvest quality of broccoli. The broccoli plants were subjected to single foliar sprays of either Ca, Fe, Zn, or Mn, which was repeated four times during plant growth at a 1 g/kg concentration. Once harvested, the broccoli heads were refrigerated at 4 °C for 28 days. Our results indicated that foliar application of Ca, Zn, Mn, and Fe did not have a significant effect on plant growth parameters, apart from enhancing Soil Plant Analysis Development (SPAD) chlorophyll meter values. However, during postharvest, foliar application treatment showed a positive response on weight loss during storage and reduction in yellowing of the broccoli heads. Foliar treatments increased the concentration of Nitrogen (N), Phosphorus (P), Ca, Zn, Mn and Fe significantly in the broccoli head tissue. Total chlorophyll content, total phenolic compound, ascorbic acid, peroxidase activity, glucoraphanin and glucobrassicin and flavonoids were significantly increased by all foliar treatments. Crude protein content and sulforaphane were enhanced by Ca and Mn treatments. Overall, foliar application of the investigated mineral nutrients may prove beneficial in improving the shelf-life and nutrient content of broccoli during postharvest handling and storage

    RESPONSE OF STRAWBERRY PLANTS TO SHORTENING DAY LENGTH , SHADING AND COLD STORAGE UNDER EGYPTIAN CONDITIONS

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    This experiment was performed in 2004/2005 and 2005/2006 seasons at El-Bosaly Protected Cultivation Experimental Site, of the Central Laboratory for Agricultural Climate (CLAC), 15 Km west of Rosetta. The current study was conducted in open field to investigate the growth and productivity of strawberry plants under the shading and cold storage methods. Two strawberry cultivars were used, i.e., Camarosa (cv.) and Yael (cv.). Transplants were set up on 15 of March to 15 of September in both two seasons of 2004-2005 and 2005-2006, respectively under El-Bosaly conditions. Seven treatments were used i.e., short day, 40% shading, 73% shading, three periods cold storage at 5Co, i.e., (24h, 48h and 73h) and control. Results indicated that the application of 73% shading treatment was the most effective in reducing maximum and minimum of air temperature and radiation, followed by 40% shading, whereas, the highest value of maximum and minimum air temperature, radiation were observed in control treatment throughout the two growing seasons. In addition, 73% shading treatment produced the tallest plants and the highest number of leaves per plant and leaf area per plant. Moreover, flowering and chlorophyll in leaves were increased by application of short day treatment. Also, fruit characters such as average weight and number of fruits per plant were the highest values with 40% shading. Chemical components of fruits, i.e., T.S.S were increased with 73% shading treatment. When plants were grown under 40% shading treatment, followed by 73% shading, while cold storage for 72 h treatment gave the lowest values. Neither cultivars nor the interaction between cultivars and tested factors had any significant effects on many studied characters

    SYNTHESIS, ANTICANCER ACTIVITY AND MOLECULAR DOCKING STUDY OF NOVEL 1, 3-DIHETEROCYCLES INDOLE DERIVATIVES

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    Objective: The present work aimed to synthesize some new 1, 3-diheterocyles indolyl derivatives and study their cytotoxic activity. In addition, explore the probability of the most promising antiproliferative compounds to inhibit TopoI enzyme theoretically via molecular docking study.Methods: Reaction of ethyl 2-(3-formyl-1H-indol-1-yl)acetate (1) with 2-cyanoacetic acid hydrazide, 3-amino-5-pyrazolone and 2'-acetyl-2-cyanoacetohydrazide in an equal molar ratio led to the formation of compounds 2, 6, 8 and 10, respectively, which in turn reacted with another molecule of 2-cyanoacetic acid hydrazide and/or 3-amino-5-pyrazolone (1:1 molar ratio) to give novel series of 1,3-dipyrazole indole derivatives 3, 7, 9 and 11, respectively. On the other hand, Knoevenagel condensation of 1 with malononitrile gave ethyl 2-(3-(2, 2-dicyanovinyl)-1H-indol-1-yl) acetate (11). Reaction of 11 with 2-cyanoacetic acid hydrazide, 3-amino-5-pyrazolone, hydrazine hydrate, urea, thiourea and/or guanidine yielded 1, 6-diaminopyridine 12, pyrano(2,3-c)pyrazole 14, pyrazole 16 and pyrimidine derivatives 18a-c, respectively. Reaction of the latter compounds with 3-amino-5-pyrazolone furnished a novel series of 1, 3-diheterocycle indole derivatives 13, 15, 17 and 19a-c, respectively. Ten new target compounds 3, 6, 8, 10, 13, 15, 17 and 19a-c were tested for in vitro antiproliferative activity against A-549, MCF7, HCT-116 and HEPG2 cancer cell lines. In addition, molecular docking study of the most promising antiproliferative compounds against human DNA Topoisomerase I (PDB ID: 1T8I) theoretically is discussed.Results: Compounds 3, 6, 8 and 17 showed potent in vitro antiproliferative activity. Docking scores of the latter compounds were observed better than co-crystalline ligand.Conclusion: Further work is recommended to confirm the inhibition of TopoI in a specific bioassay

    SYNTHESIS AND ANTIVIRAL ACTIVITY OF NOVEL ETHYL 2-(3-HETEROCYCLE-1H-INDOL-1-YL) ACETATE DERIVATIVES

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    Objective: Marek's disease (MD) is a widespread, herpesvirus-induced neoplastic disease in the domestic chicken that is caused by Marek's disease virus (MDV). Marek’s disease virus (MDV) belongs to the alphaherpesvirus family such as Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2). Recently Bag and co-workers 2014 reported that, 7-methoxy-1-methyl-4, 9-dihydro-3H-pyrido [3, 4-b]indole (Harmaline) showed potent anti-HSV-1 activity against both wild type and clinical isolates of HSV-1. The present work aimed to synthesize some new heterocyclic systems incorporated to indole moiety starting from ethyl 2-(3-acetyl-1H-indol-1-yl)acetate (1) in order to evaluate their antiviral activity in a trail to explore potential antiviral agents against MDV to limit the disease course and losses. Methods: Reaction of ethyl 2-(3-acetyl-1H-indol-1-yl) acetate (1) with semicarbazide hydrochloride yielded semicarbazone derivative 2. The oxidative cyclization of 2 using thionyl chloride and selenium dioxide afforded 1, 2, 3-thia and 1, 2, 3-selenadiazole derivatives 3 and 4, respectively. On the other hand, reaction of 1 with 4-chloro and 4-nitrobenzaldehydes under Claisen-Schmidt conditions gave α, β-unsaturated keto derivatives 5a, b. Cyclization of 5a, b using hydrazine hydrate, phenyl hydrazine, urea, thiourea or guanidine led to the formation of pyrazoles 6a, b, 7a, b, and pyrimidines derivatives 8a, b-10a, b; respectively. Condensation of 1 with phenyl hydrazine followed by Vilsmeier Haack formylation gave pyrazole-4-carboxaldehyde derivative 12. Reaction of aldehydic function group of 12 with different reagents led to the formation of pyrazol-5-ones 14-16, thiazolidinone 18, aziditine 19, 1, 6-diaminopyridine 21, triazolo(1, 5-a)pyridine 22 and pyrano(2, 3-c) pyrazole derivatives 23. The in vitro antiviral activity of the selected compounds 6a, b 7a, b 8a, b 9a, b and 10a, b was studied against Marek's disease virus (MDV). Results: Chicken embryo experiment showed that compounds 7b, 8b, 9b and 10a possessed significant antiviral activity with IC50 ranged between 5 and 6 µg/ml and substantial therapeutic indices (TI) of 80 and 83 were recorded. Cytotoxicity assay indicated that CC50 of 7b, 8b, 9b and 10 were greater than 400 and 500 mg/ml. Conclusion: Compounds 7b, 8b, 9b and 10a showed promising effect as anti-MDV infectivity application

    Efficacy of plant extracts in controlling wheat leaf rust disease caused by Puccinia triticina

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    AbstractThe efficacy of eight plant extracts (garlic, clove, garden quinine, Brazilian pepper, anthi mandhaari, black cumin, white cedar and neem) in controlling leaf rust disease of wheat was investigated in vitro and in vivo. In vitro, all treatments inhibited spore germination by more than 93%. Neem extract recorded 98.99% inhibition of spore germination with no significant difference from the fungicide Sumi-8 (100%). Under greenhouse conditions, seed soaking application in neem extract (at concentration of 2ml/L) resulted in 36.82% reduction in the number of pustules/leaf compared with the untreated control. Foliar spraying of plant extracts on wheat seedlings decreased the number of pustules/leaf. Foliar spraying of plant extracts four days after inoculation led to the highest resistance response of wheat plants against leaf rust pathogen. Spray application of wheat seedlings with neem, clove and garden quinine extracts, four days after inoculation with leaf rust pathogen completely prevented rust development (100% disease control) and was comparable with the fungicide Sumi-8. Foliar spray application of wheat plants at mature stage with all plant extracts has significantly reduced the leaf rust infection (average coefficient of infection, ACI) compared with the untreated control and neem was the most effective treatment. This was reflected on grain yield components, whereas the 1000-kernel weight and the test weight were improved whether under one- or two-spray applications, with two-spray application being more effective in this regard. Thus, it could be concluded that plant extracts may be useful to control leaf rust disease in Egypt as a safe alternative option to chemical fungicides

    Early administration of oral oseltamivir increases the benefits of influenza treatment

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    Our objective was to evaluate the benefit of early treatment of influenza illness using oral oseltamivir. This open-label, multicentre international study investigated the relationship between the interval from illness onset to first dose (time-to-treatment) and illness duration in the intent-to-treat infected population using accelerated failure time (AFT) modelling. A total of 1426 patients (12-70 years) presenting within 48 h of the onset of influenza symptoms were treated with oseltamivir 75 mg twice a day for 5 days during the 1999-2000 influenza season; 958 (67%) had laboratory-confirmed influenza virus infection. Earlier intervention was associated with shorter illness duration (P < 0.0001). Initiation of therapy within the first 12 h after fever onset reduced the total median illness duration by 74.6 h (3.1 days; 41%) more than intervention at 48 h. Intermediate interventions reduced the illness proportionately compared with 48 h. In addition, the earlier administration of oseltamivir further reduced the duration of fever, severity of symptoms and the times to return to baseline activity and health scores. Oseltamivir was well tolerated. The most common adverse events were nausea and vomiting, which were transient and generally occurred only with first dosing. When oseltamivir was taken with food, the tolerability was enhanced. The overall discontinuation rate was low (1.8%). In conclusion, the IMPACT study demonstrated that earlier initiation of oral oseltamivir therapy increased its therapeutic effects, which were seen at every time point of intervention and were progressive. Thus, early presentation, diagnosis and treatment of patients with influenza maximized the benefits of oseltamivir therap

    Hydroxamic acid surface active agents

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