Formulation and characterization of self compacting concrete with silica fume

Self-compacting concrete (SCC) was elaborated using local materials and silica fume (SF) as admixture in 15% of cement quantity, two different Portland cements (PC) and two different superplasticizer that the chemical nature is polycarboxylate and plynaphtalene, the aggregates used are (AG 3/8 mm, AG 8/15 mm), coarse and fine sand (SC, SF) witch fineness modulus 3.2 and 1 in the order. The dosage of the different superplasticizer used is chosen after experimental spreading tests of each self compacting concrete formulation. Results of fresh concrete tests executed, as L-box and segregation resistance are on concordance whit values recommended by the French association of civil engendering. Also the mechanical characterization was conducted by compressive strength and splitting compression testing procedure, results values are in the range higher than 20 Mpa at the seven day by the compressive test for the all compositions, and the highest value was 40.93 MPa at the 28 day bay compressive test of the fourth’s formulation specimens, the values of splitting compressive tests of al formulation specimens at 7, 14 and 28 days, was situated between 2.01 and 4.40 MPa. In order to determine the superplasticizer saturation assay in of cement pasts used in self compacting concrete, the stady was completed by a rheological stady with a variable velocity gradient, so as to estimate the quantity of saturation assay of superplasticizer and the formulation, also the flow models of cement past

Chemical composition, antioxidant, and anticancer effect of Ruta chalepensis's extracts against human leukemic cells

Ruta chalepensis is a native herb of the Mediterranean region used in the traditional medicine of many countries. Phytochemical screening has shown the presence of bioactive molecules that are responsible for its pharmacological properties. The present study aimed at investigating the in vitro antioxidant and cytotoxic effect of volatile, ethanol and aqueous extracts of R. chalepensis collected from Bejaia, a region in Algeria. The phenolic compounds composition of the extracts was analyzed by HPLC-UV (High Performance Liquid Chromatography with UV detector) and the essential oil composition was analyzed by GC-MS (Hewlett Packard 5973-6890 GC-MS system) analysis. The antioxidant activity was assessed by the scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazyl) and the cytotoxic effect of MTT assay against cancerous cells (T-leukemic cells and B lymphoblasts) and normal blood cells (PBLs: stimuled peripheral blood cells by PHA/IL2). Ethanol extract of R. chalepensis presented the highest amount of total phenolics (72. 08 ± 1.94 mg GAE/g DW (Milligrammes of Galic Acid per Grammes of Dry Weight), flavonoids (31.90 ± 2.12 mg QE/g DW (Milligrammes of Quercetin Equivalent per Grammes of DryWeight), and flavonols (13.22 ± 0.86 mg QE/g DW) compared to the aqueous extract, which presented a total phenolics of 39.71 ± 0.22 mg GAE/g DW, flavonoids of 1.96 ± 0.12 mg QE/g DW, and flavonols of 3.00 ± 0.2586 mg QE/g DW. Ethanol extract also showed a potent antioxidant activity (IC50= 51.18 ± 1, 14 μg/ml) and a high reducing power (IC50 = 660 ± 8, 3 μg/ml). Moreover, we establish herein that ethanol extract exerts a strong cytotoxicity against T-leukemic cells (CEM, H9, Jurkat, and CEM-IRCs) and B lymphoblast cells (SKW 6.4) without affecting normal blood cells (PBL and PBLs).This study showed that Ruta chalepensis can be used as promising source of natural antioxidant and anticancer agents. The encouraging results obtained on anticancer activity suggest further investigations can be undertaken to isolate the bioactive phenolic compounds and to understand their mechanism of cytotoxicity. © Lavoisier SAS 2017