145 research outputs found
DĂ©couverte d'un Ă©crit mathĂ©matique d'al-HÌasÌsÌÄr (XIIe S.): Le livre I du KÄmil
RĂ©sumĂ©L'article prĂ©sente des Ă©lĂ©ments nouveaux sur l'oeuvre du mathĂ©maticien de l'occident musulman mĂ©diĂ©val-al-HÌasÌsÌÄr-en se basant sur le contenu de son traitĂ© de calcul-le KitÄb al-KÄmil- dont le premier volume vient d'ĂȘtre identifiĂ©, ainsi que sur des informations puisĂ©es dans la tradition mathĂ©matique arabe du Maghreb.AbstractThe paper gives some new elements of the work of HÌasÌsÌÄr, a mathematician of the medieval West muslim. It is based on the contents of the KitÄb al-KÄmil, his mathematics book, the first volume of which has just been identified, and on information drawn from the Arabic mathematical tradition of the Maghrib
Hydrothermal complex of the Souk Ahras Basin: geological and hydrogeochemical approaches (north east of Algeria)
North- East of Algeria, in The Souk Ahras region, the Triassic evaporates are in the form of important intrusive masses. Thermal and cold water emerge from various training. These sources present are taking their pathways along the faulting system. A complex multilayered reservoir has significant potential water. The karstic aquifer consists mainly on fresh water. Thermal water characterized by high salinity is carbo-gaseous. Collection and chemical analysis of major water elements in addition to nonionic mineral compounds (SiO2) and trace elements (Sr2+, F-, Br-) have determined a deep saline fluid circulation. The tectonic effect would be responsible for the current water flow. Cartography of fracturing system has identified a NNW-SSE hot spring distribution. Similar alignment can match the faulting system direction affecting the concerned study area.Keywords: Triassic evaporate; thermal waters; tectonic; deep fluid circulatio
Short-term effect of sawdust biochar and bovine manure on the physiological behavior of turnip (Brassica rapa L.) grown in open fields in the Algiers region
ArticleThis study was designed to determine the effect of different doses of biochar (B) 5.10, 20tha-1alone and mixed with manure (F) 10tha-1on turnips. The results showed that the OM (organic matter) rate had a maximum of 93.7% for (B20*F) and a minimum of 14.5% for (F); the CEC (cation exchange capacity) showed a maximum of 32.2% for (B10*F) and a minimum of 0.2% with (B5*F) compared to the control (T) and finally the pH to be increased with a maximum value of 11.2% for (B20*F) and a minimum value of 1.7% for (F) compared to (T) (â€0.01).For the chemical parameters of the turnip, the maximum nitrogen rate was 93.8% with (B10) and 2% for (B20). The highest value for phosphorus was recorded in (F) and a minimal value in (B5) (â€0.01).The potassium level was high 4.2% for the treatment (B20*F) with the lowest value of 4.4% for (B5) and (B10) compared to (T) (0.05).For the yield components, thefresh weight of the most important bulb was obtained with (F) with the value of 116.8% and minimum weight of 0.4% in the treatment (B5). The highest bulb length value was 36.8% in (F) and the lowest was 0.5% obtained with (B20*F). The bulb diameter was the largest in the treatment (F) and the smallest was 4.8% in (B20). Finally, the fresh weight of the leaves showed a maximum of 106.9% in (F) and an increase of 6% in (B20) compared to (T) (â€0.01)
Impact of bonding defect on the tensile response of a composite patch-repaired structure: Effect of the defect position and size
Adhesive bonding has seen rapid development in recent years, with emphasis to composite patch repairing processes of geometric defects in aeronautical structures. However, its use is still limited given its low resistance to climatic conditions and requirement of specialized labor to avoid fabrication induced defects, such as air bubbles, cracks, and cavities. This work aims to numerically analyze, by the finite element method, the failure behavior of a damaged plate, in the form of a bonding defect, and repaired by an adhesively bonded composite patch. The position and size of the defect were studied. The results of the numerical analysis clearly showed that the position of the defect in the adhesive layer has a large effect on the value of J-Integral. The reduction in the value of J-Integral is also related to the composite stacking sequence which, according to the mechanical properties of the ply, provides better load transfer from the plate to the repair piece through the adhesive. In addition, the increase in the applied load significantly affects the value of the J-Integral at the crack tip in the presence of a bonding defect, even for small dimensions, by reducing the load transfer.info:eu-repo/semantics/publishedVersio
Spectrometric Analyses, Structure and Voltammetric Study of Nickel(II) with N[(1E) Phenylmethylene N2[2(2Hydroxyphenylmethylene]Amino ethyl) Imidazolidin-1-yl Ethylamine
The reaction of N[(1E) phenylmethylene N2[2(2hydroxyphenylmethylene]amino ethyl) imidazolidin -1-yl ethylamine ligand (H 3 L) with nickel(II) salt, by heating at 40°C and addition of NaOH in excess, was made by eliminating of the phenol substituted imidazolidine ring, giving the mononuclear nickel(II) complex of the deprotonated bis-salicylaldehyde-triethylenetetramine (L â2 ). UV-Vis, FTIR and structural resolution show an octahedral geometry for [NiL]·6H 2 O complex. This compound has been characterized by single crystal X-ray diffraction study. This technique reveals that Ni-H 2 L involves a high-spin nickel(II) ion within a pseudo-octahedral geometry. The Ni(II) complex has NiN 4 O 2 coordination sphere as established from a crystal structure determination. The crystals of Ni(II) complex are tetragonal, space group P4/ncc, a = b = 19.348 A; c = 13.201 A. R(F) value (0.0528) found shows a very good precision of the determined geometrical parameters. Cyclic voltammetry of nickel complex is indicative of electronic communication between the nickel center via Schiff base ligand. The results obtained confirm the imidazolidine ring-cleavage reaction and the elimination of the substituted phenol on this ring and show that the presence of H 3 L ligand around the metallic center stabilizes the oxidation of the Ni(II) to Ni(III)
The fate and behavior of selected endocrine disrupting chemicals in full scale wastewater and sludge treatment unit processes
Endocrine disrupting chemicals are discharged into the environment
mainly through wastewater treatment processes. There is a need for
better understanding of the fate of these compounds in the unit
processes of treatment plant to optimize their removal. The fate of
oestrone, 17ÎČ-estradiol, 17α-ethinyestradiol and nonylphenol
in the unit processes of full scale wastewater treatment plants in the
UK, including activated sludge plant, oxidation ditch, biofilter and
rotating biological contractor were investigated. The overall removal
efficiencies of all the compounds ranged from 41 % to 100 %. The
removals were predominantly during the secondary biological treatment
with the rates of removal related to the nitrification rates and the
sludge age. The removal efficiency of the treatment processes were in
the order activated sludge > oxidation ditch > biofilter >
rotating biological contractors. Activated sludge plant configured for
biological nutrient removal showed better removal of the endocrine
disrupting chemicals compared to conventional activated sludge plant
effluents. Tertiary treatment was also significant in the removal
process through solids removal. Overall mechanisms of removal were
biodegradation and sorption unto sludge biomass. Phytoremediation was
also significant in the removal processes. The endocrine disrupting
chemicals persisted in the anaerobic sludge digestion process with
percentage removals ranging fro 10-48 %. Sorption of the endocrine
disrupting chemicals onto the sludge increased with increasing values
for the partitioning coefficients and the organic carbon contents of
the sludge
Numerical study of effect of elastomeric stress absorbers on stress reduction in bone-dental implant interface
Aqueous Cinnamon Extract (ACE-c) from the bark of Cinnamomum cassia causes apoptosis in human cervical cancer cell line (SiHa) through loss of mitochondrial membrane potential
<p>Abstract</p> <p>Background</p> <p>Chemoprevention, which includes the use of synthetic or natural agents (alone or in combination) to block the development of cancer in human beings, is an extremely promising strategy for cancer prevention. Cinnamon is one of the most widely used herbal medicines with diverse biological activities including anti-tumor activity. In the present study, we have reported the anti-neoplastic activity of cinnamon in cervical cancer cell line, SiHa.</p> <p>Methods</p> <p>The aqueous cinnamon extract (ACE-<it>c</it>) was analyzed for its cinnamaldehyde content by HPTLC analysis. The polyphenol content of ACE-<it>c </it>was measured by Folin-Ciocalteau method. Cytotoxicity analysis was performed by MTT assay. We studied the effect of cinnamon on growth kinetics by performing growth curve, colony formation and soft agar assays. The cells treated with ACE-<it>c </it>were analyzed for wound healing assay as well as for matrix metalloproteinase-2 (MMP-2) expression at mRNA and protein level by RT-PCR and zymography, respectively. Her-2 protein expression was analyzed in the control and ACE-<it>c </it>treated samples by immunoblotting as well as confocal microscopy. Apoptosis studies and calcium signaling assays were analyzed by FACS. Loss of mitochondrial membrane potential (ÎÏ<sub>m</sub>) in cinnamon treated cells was studied by JC-1 staining and analyzed by confocal microscopy as well as FACS.</p> <p>Results</p> <p>Cinnamon alters the growth kinetics of SiHa cells in a dose-dependent manner. Cells treated with ACE-<it>c </it>exhibited reduced number of colonies compared to the control cells. The treated cells exhibited reduced migration potential that could be explained due to downregulation of MMP-2 expression. Interestingly, the expression of Her-2 oncoprotein was significantly reduced in the presence of ACE-<it>c</it>. Cinnamon extract induced apoptosis in the cervical cancer cells through increase in intracellular calcium signaling as well as loss of mitochondrial membrane potential.</p> <p>Conclusion</p> <p>Cinnamon could be used as a potent chemopreventive drug in cervical cancer.</p
Acetonic Extract of Buxus sempervirens Induces Cell Cycle Arrest, Apoptosis and Autophagy in Breast Cancer Cells
Plants are an invaluable source of potential new anti-cancer drugs. Here, we investigated the cytotoxic activity of the acetonic extract of Buxus sempervirens on five breast cancer cell lines, MCF7, MCF10CA1a and T47D, three aggressive triple positive breast cancer cell lines, and BT-20 and MDA-MB-435, which are triple negative breast cancer cell lines. As a control, MCF10A, a spontaneously immortalized but non-tumoral cell line has been used. The acetonic extract of Buxus sempervirens showed cytotoxic activity towards all the five studied breast cancer cell lines with an IC50 ranging from 7.74 ”g/ml to 12.5 ”g/ml. Most importantly, the plant extract was less toxic towards MCF10A with an IC50 of 19.24 ”g/ml. Fluorescence-activated cell sorting (FACS) analysis showed that the plant extract induced cell death and cell cycle arrest in G0/G1 phase in MCF7, T47D, MCF10CA1a and BT-20 cell lines, concomitant to cyclin D1 downregulation. Application of MCF7 and MCF10CA1a respective IC50 did not show such effects on the control cell line MCF10A. Propidium iodide/Annexin V double staining revealed a pre-apoptotic cell population with extract-treated MCF10CA1a, T47D and BT-20 cells. Transmission electron microscopy analyses indicated the occurrence of autophagy in MCF7 and MCF10CA1a cell lines. Immunofluorescence and Western blot assays confirmed the processing of microtubule-associated protein LC3 in the treated cancer cells. Moreover, we have demonstrated the upregulation of Beclin-1 in these cell lines and downregulation of Survivin and p21. Also, Caspase-3 detection in treated BT-20 and T47D confirmed the occurrence of apoptosis in these cells. Our findings indicate that Buxus sempervirens extract exhibit promising anti-cancer activity by triggering both autophagic cell death and apoptosis, suggesting that this plant may contain potential anti-cancer agents for single or combinatory cancer therapy against breast cancer
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