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Mesoporous silica Si-MCM-41 was prepared by hydrothermal method using TEOS and CTAB as the source of silica and structuring agent, respectively. The surface of the as-synthesized material was treated using HCl/ETOH solvent to remove the CTA surfactant instead of using the calcination. Characterization of the catalysts was performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen sorption at 77 K, scanning and transmission electronic microscopy (SEM, TEM), and thermogravimetric analysis TGA. The catalytic properties of the prepared materials in the condensation of acetophenone with ethyl cyanoacetate were studied. The effects of the catalyst type, Si/Al ratio, reaction kinetics, and reaction temperature were also investigated to find an optimal parameter. The results show that an interesting yield was obtained (about 96%) in a short reaction time; it is found that the yields of products depend not only on the amount of surfactant inside the mesopores but also on the Si/Al ratio. The catalyst reuse shows that this catalyst can be used up to five cycles, and at temperatures higher than 50 °C, the yield of products decreases due to the slight destruction of the catalyst as confirmed by the XRD analysis. Based on the results obtained, a possible mechanism of the condensation reaction of acetophenone was proposed.

ABSTRACTThis work is focused on the selectivity of the elimination of cadmium (II) and lead (II) by novel hybrid material which has been synthesized and characterized previously (Zn/Al-DDPA). This study has obliged us to highlight the effect of equilibrium time, effect of concentration of pollutants, effect of the amount of the adsorbent and the effect of adding salts. Thermodynamic study confirms that the adsorption process is exothermic and spontaneous process with a disorder between the two phases and that the adsorbent is reusable after three steps of desorption. The best extraction yield for this study is more than 70% for cadmium (II).

Polymer springs that twist under irradiation with light, in a manner that mimics how plant tendrils twist and turn under the effect of differential expansion in different sections of the plant, show potential for soft robotics and the development of artificial muscles. The soft springs prepared using this protocol are typically 1 mm wide, 50 μm thick and up to 10 cm long. They are made from liquid crystal polymer networks in which an azobenzene derivative is introduced covalently as a molecular photo-switch. The polymer network is prepared by irradiation of a twist cell filled with a mixture of shape-persistent liquid crystals, liquid crystals having reactive end groups, molecular photo-switches, some chiral dopant and a small amount of photoinitiator. After postcuring, the soft polymer film is removed and cut into springs, the geometry of which is determined by the angle of cut. The material composing the springs is characterized by optical microscopy, scanning electron microscopy and tensile strength measurements. The springs operate at ambient temperature, by mimicking the orthogonal contraction mechanism that is at the origin of plant coiling. They shape-shift under irradiation with UV light and can be pre-programmed to either wind or unwind, as encoded in their geometry. Once illumination is stopped, the springs return to their initial shape. Irradiation with visible light accelerates the shape reversion.

ABSTRACTIn this work, the adsorption of basic fuchsine largely used in industries was studied by Zn/Al-HDL intercalated with diamino-dodecylphosphonic acid (DDPA). The physicochemical characteristics of Zn/Al-DDPA were evaluated by Brunauer–Emmett–Teller method, Fourier transform infrared spectroscopy, X-ray diffraction, and the elementary analysis to determine the rate of grafting. The effect of concentration of fuchsine, reaction times, ionic strength effect and the effect of the temperature were studied. The thermodynamic and kinetic studies were carried out and the results confirmed that all adsorption processes were spontaneous and thermodynamically favorable and that the adsorbent is reusable after three steps of desorption. The best uptake in this study was 90%.

Grímsvötn Volcano is the most active volcano in Iceland, and its last three eruptions were in 1998, 2004, and 2011. Here we analyze the displacement around Grímsvötn during these last three eruptive cycles using 10 GPS stations. The observed displacements in this region generally contain a linear component of tectonic and glacio‐isostatic origin, in agreement with the previously estimated values of plate motions and vertical rebound. Larger amplitude deformation observed close to Grímsvötn at the GFUM continuous GPS station clearly reflects a major volcanic contribution superimposed on a tectonic component. We estimate and subtract the tectonic trend at this station using regional observed displacement. The direction and pattern of the residual volcanic displacement (for coeruptive and intereruptive periods) are consistent for all three of these eruptive cycles. The posteruptive inflation is characterized by an exponential trend, followed by a linear trend. In this study, we explain this temporal behavior using a new analytic model that has two connected magma chambers surrounded by an elastic medium and fed by a constant basal magma inflow. During the early posteruptive phase, pressure readjustment occurs between the two reservoirs, with replenishment of the shallow chamber from the deep chamber. Afterward, due to the constant inflow of magma into the deep reservoir, the pressurization of the system produces linear uplift. A large deep reservoir favors magma storage rather than surface emission. Based on displacement measured at GFUM station, we estimate an upper limit for the radius of the deep reservoir of ∼10 km. GPS time series for the last three intereruptive cycles of Grimsvotn are analyzedWe propose a model with two connected magmatic chambers, with basal magma inflowThe vertical deformation limits the lateral extension of the deep reservoir

AbstractIn the present paper, extraction procedure for copper (II) present in an aqueous sulphate media using a supported liquid membrane by chloride tri-N-octylmethylammonium (Aliquat 336) and Tri-n-butylphosphate from molar ratio 1:1, with polytetrafluoroethylene as a membrane support was studied. The effects of various parameters such as initial pH, potassium thiocyanate concentration and ammonium acetate concentration on the extraction yield, were carried out. By a calculation programme using Chemical Equilibrium in Aquatic System V. L20.1, the determination of the percentages of the present species before and after extraction were given in aqueous medium and on the membrane to be able to determine the relation between the nature of the extracted species and the extraction yield. The optimization process was carried out using 23factorial designs. Initial pH (pHi) of feed solution, the concentration of potassium thiocyanate and the concentration of ammonium acetate were regarded as factors in the optimization. Student’s t-test on the results of the 23factorial design with eight runs for copper (II) extraction demonstrated that the factor concentration of potassium thiocyanate in the levels studied are statistically significant. Under the optimum conditions the percentage of extracted copper (II) was 93.6% in one step.

We herein describe the synthesis and antibacterial activity of cyclic sulfamide linked to tetrathiafulvalene (TTF). This approach exploits the inherent chemistry of biomolecules and π-donors compounds to generate symmetric bis-trimethyltetrathiafulvalenyl-2-thiophenyl cyclic sulfamides. Two strategies are revealed, one centres on the Ringclosing olefin metathesis using the Grubbs catalyst a second strategy based on the direct alkylation of dibromoalkane derivatives with symmetric sulfamide under basic conditions. All the newly synthesized compounds were screened for their antimicrobial activities and some of them were found to possess good or moderate antimicrobial activity.

An on‐column solvent‐free oxidative cleavage reaction of vicinal diols by paraperiodic acid supported on silica gel at room temperature is described. The resulting pure carbonyl compounds are prepared in good to excellent yields with short reaction times. The cleavage reactions proceed under mild conditions, which avoids further cyclization reactions of the product dialdehydes. This method is also used for sequential oxidation and Knoevenagel reactions to prepare condensation products in good yields by using paraperiodic acid on a mixed bed of alumina and silica gel.

A classification structure-activity relationship study has been carried out using topological indices, physicochemical and steric parameters on a series of 1-[2-hydroxyethoxy-methyl]-6-(phenylthio) thymine for their HIV reverse transcriptase inhibitory activity. The predictive classification performance of support vector machines method is investigated and compared with those of other classifiers such as artificial neural networks, linear discriminant analysis, k-nearest neighbours and decision trees. This paper discusses several validation strategies including randomization test, internal and external validations. The quality of the models was evaluated by the number of right classified compounds. The results obtained show that all methods used except k-nearest neighbours were good classifiers. The percentage of right classified compounds ranges from 87.7 to 95.4 and from 64.3 to 92.9 for the training and test sets, respectively. The relevant factors controlling the anti-HIV activity have been identified. The descriptors related to both steric characters (6Xvch, 4XNP and 1/S) and hydrophobic parameter (logP) seem to be very relevant in the establishment of structure-anti- HIV activity relationship.

An unprecedented simple on‐column solvent‐free oxidative cleavage of vicinal diols in the solid phase using alumina/potassium metaperiodate is described herein. It permits preparation of the corresponding carbonyl compounds with high purity and good to excellent yields requiring only short reaction times. This methodology is then employed in on‐column sequential oxidation/Horner–Emmons reactions for the preparation of selected stilbenes in good yields where both reaction and purification are integrated in a single unit or occur simultaneously permitting the rapid and easy preparation of small samples of pure stilbenes.

A new methodology named solidphase reactive chromatography SPRC, which combines reaction, separation, and purification into a single unit for the preparation of small samples, is described. This method was illustrated in the synthesis of some natural bioactive compounds, namely, methoxylated analogues of resveratrol, alkylresorcinols, and 5aryl2,4pentadienoates, over a column of aluminaKF under microwave irradiation by using the Wittig and Horner–Emmons reactions. This approach permitted the preparation of the target olefins with high purity and good to excellent yields in short reaction times.

Human Immunodeficiency Virus type 1 reverse transcriptase is an important target for chemotherapeutic agents against the AIDS disease. 12Hydroxyethoxymethyl6phenylthio thymine derivatives are potent nonnucleoside reverse transcriptase inhibitors. In the present work, quantitative structureactivity relationship analysis for a set of 79 HEPT derivatives has been investigated by means of support vector machines. The relationships between structure and activity were examined quantitatively using descriptors encoding the steric, hydrophobic, electronic and structural features of 12hydroxyethoxymethyl6phenylthio thymine derivatives. The performance and predictive capability of support vector machines method are investigated and compared with other methods such as artificial neural network and multiple linear regression methods. The obtained results indicate that the support vector machines model with the kernel radial basis function can be employed as a forceful tool for quantitative structureactivity relationship studies. The contribution of each descriptor to the structureactivity relationships was evaluated.

Background: Vascular endothelial growth factor (VEGF) and histamine induce von Willebrand factor (VWF) release from vascular endothelial cells. Protein kinase C (PKC) is involved in the control of exocytosis in many secretory cell types. Objectives: We investigated the role of PKC and the interactions between PKC and Ca2+signaling in both VEGF-induced and histamine-induced VWF secretion from human umbilical vein endothelial cells (HUVECs). Results: Several PKC inhibitors (staurosporine, Ro31-8220, myristoylated PKC peptide inhibitor and Go6983) block VEGF-induced but not histamine-induced VWF secretion. PKC-α and novel PKCs (PKC-δ, PKC-ε, and PKC-η), but not PKC-β, are expressed in HUVECs. Both VEGF and histamine activate PKC-δ. However, gene inactivation experiments using small interfering RNA indicate that PKC-δ (but not PKC-α) is involved in the regulation of VEGF-induced but not histamine-induced secretion. Both VEGF and histamine induce a rise in cytosolic free Ca2+([Ca2+]c), but the response to VEGF is weaker and even absent in a significant subset of cells. Furthermore, VEGF-induced secretion is largely preserved when the rise in [Ca2+]cis prevented by BAPTA-AM. Conclusions: Our study identifies striking agonist specificities in signal–secretion coupling. Histamine-induced secretion is dependent on [Ca2+]cbut not PKC, whereas VEGF-induced secretion is largely dependent on PKC-δ and significantly less on [Ca2+]c. Our data firmly establish the key role of PKC-δ in VEGF-induced VWF release, but suggest that a third, VEGF-specific, signaling intermediate is required as a PKC-δ coactivator.

A convergent approach to functionalise aromatic compounds with a linker terminated by a phosphonate group is reported. The starting point of this strategy is the synthesis of five new ω-alkyne-phosphonates. The linker between the phosphonate group and the alkyne part is either an alkyl or an ether chain. This strategy is based on the use of the phosphonate group as the anchoring point for the attachment of organic compounds onto alumina and the alkyne group, which is used to functionalise aryl halide compounds by a Sonogashira cross-coupling. The use of 1,10-phenanthroline as substrate illustrates the application of this strategy to an aromatic ligand. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

L’accumulation des déchets organiques, d’origine végétale ou animale, constitue actuellement un réel problème environnemental. Le compostage est aujourd’hui une des voies privilégiées du recyclage de ces déchets. Ces composts servent à réhabiliter les sols ou à reconstituer leur stock organique. La caractérisation des composts impose aujourd’hui le développement de méthodes analytiques performantes. Dans cet article, nous présentons une nouvelle méthode analytique de ces produits, basée sur la caractérisation morphologique et analytique des microstructures des matières organiques en microscopie électronique à transmission. Par un échantillonnage spécifique, cette méthodologie tient compte de l’hétérogénéité de ces produits, tant en ce qui concerne leur nature que leur granulométrie. Cette méthodologie s’appuie sur une banque de données en imagerie et micro-analyses EDX et EELS, effectuées à cette échelle et obtenues sur un grand nombre de matières premières utilisées dans les composts et sur des produits finis. Sont présentés et discutés ici, à titre d’exemple, les résultats concernant l’analyse de matières premières : déchets verts, écorces, boues de station d’épuration, et de composts fabriqués à partir de ces matières premières co-compostées. Les principaux points forts de cette méthode sont :la reconnaissance des entrants,la précision de leur niveau d’humification,l’évaluation du potentiel bactérien,la détection et la localisation des éléments fertilisants (C,N…) ou polluants (éléments traces métalliques).Cette expertise constitue un véritable outil de traçabilité et d’évaluation de la qualité des composts et permet de préconiser une meilleure utilisation de ces produits.

Objective:von Willebrand factor (VWF) is acutely released from endothelial cells in response to numerous calcium‐raising agents (e.g. thrombin, histamine) and cAMP‐raising agents (e.g. epinephrine, adenosine, vasopressin). In contrast, very few inhibitors of endothelial VWF secretion have been described. The neurotransmitter dopamine is a modulator of exocytosis in several endocrine cells, and is possibly involved in the regulation of several endothelial cell functions. We therefore investigated the effect of dopamine on endothelial VWF secretion. Results:Dopamine, D2/D3‐ and D4‐specific agonists inhibited histamine‐ but not thrombin‐induced VWF secretion. Expression of dopamine D2, D3 and D4 receptors was demonstrated by reverse transcription polymerase chain reaction (RT‐PCR) in both human aortic (HAEC) and umbilical vein (HUVEC) endothelial cells. D2–D4 agonists did not inhibit histamine‐induced rise in [Ca2+]i: they inhibited histamine‐induced secretion even in the absence of extracellular calcium. Thus, the dopamine effects are not mediated by [Ca2+]i‐dependent signalling. D2/D3‐ and D4‐specific agonists inhibited neither the rise in cAMP nor VWF secretion in response to epinephrine and adenosine, arguing against an effect on cAMP‐mediated signalling. D1 and D5 receptors were not detected in HAEC or HUVEC by RT‐PCR, and the D1/D5‐specific agonist SKF 38 393 failed to modulate VWF secretion, arguing against a role for these receptors in endothelial exocytosis. Conclusions:Dopamine inhibits histamine‐induced endothelial exocytosis by activating D2–D4 receptor, via a mechanism distinct from [Ca2+]i‐or cAMP‐mediated signaling. In contrast, D1 and D5 receptors are not functionally expressed in cultured endothelial cells. Dopamine agonists may be useful as inhibitors of endothelial activation in inflammation and cardiovascular disease.

From 1975 to 1984 the northern Icelandic rift underwent a rifting crisis. Large widening, rapid and local subsiding and uplifting occurred on the Krafla fracture swarm with several fissure eruptions. Since 1992 the area has been regularly covered by the two ERS radar satellites, allowing us to form 110 INSAR interferograms with 22 SAR scenes for mapping crustal deformation. At the regional scale, the signal is characterised by a series of parallel fringes oriented N15°W. The polarity of these fringes is constant throughout the mapped area. The measurement represents an increase of 1.7 cm/y in ground to satellite distance for the Western bloc. This signal is estimated to correspond to the combination of a horizontal opening movement and a vertical movement. In addition, the local signal at Krafla is marked by a series of concentric circular fringes forming a circle centred on the volcano and two U shaped structures, respectively upright to the South and upside down to the North of the volcano. The signal geometry indicates that the main component of movement affecting Krafla is vertical. The measured signal corresponds to a 2.2 cm/y increase in the ground to satellite distance, representing a maximum 2.4 cm/y ground subsidence. The large number of interferograms on which the deformation signal affecting Krafla is visible allows us to ascertain that the deformation rate remains constant since 1992.

Herein we report an efficient one pot synthesis of new chiral 4,5dihydro4arylspiro1,3,4thiadiazole5,2′camphane2carboxylic acid ethyl esters 5–7and 4,5dihydro3arylspiro1,4,2oxathiazole5,2′camphane 11–13, using 1,3dipolar cycloaddition of nitrilimines 2–4 and nitrile oxides 8–10to 1Rthiocamphor 1respectively. The structure of the newly prepared 1,3,4thiadiazoles 5–7obtained as pure diastereoisomers were fully established viaspectroscopic analysis and Xray structural analysis which proved the absolute configuration of the C5 spiranic carbon to be R. NMR spectral analysis were also very useful to show the new 1,4,2oxathiazoles 11–13are mixtures of two 5R5S diastereoisomers with the ratio 6:4,7:3 and 6:4 respectively.

The co-crystallisation of benzene-1,3,5-trismethylenephosphonic acid C9H15O9P31with guanidinium chloride CH6N3Cl, yields compound 2that possesses the following composition CH6N33C9H13O9P3 C9H14O9P3. The crystal structure of this supramolecular material, which possesses six crystallographically inequivalent phosphorus atoms, is reported. The packing of this 3D-supramolecular arrangement reveals the presence of 33 hydrogen bonds engaging the couples phosphonic acid-guanidinium and phosphonic acid-phosphonic acid. Solid-State MAS NMR of the sensitive 31P nucleus in this supramolecular arrangement is used in order to develop alternative analytical method to get information on supra-molecular assemblies. 31P through-space single quantum – double quantum correlation experiments have been performed leading to two possible assignments of the 6 crystallographic P sites to the corresponding resonances in the 1D 31P MAS NMR spectrum.

The co-crystallisation of benzene-1,3,5-tris(methylenephosphonic acid) [C₉H₁₅O₉P₃] 1 with guanidinium chloride [CH₆N₃]Cl, yields compound 2 that possesses the following composition [CH₆N₃]₃ [C₉H₁₃O₉P₃] [C₉H₁₄O₉P₃]. The crystal structure of this supramolecular material, which possesses six crystallographically inequivalent phosphorus atoms, is reported. The packing of this 3D-supramolecular arrangement reveals the presence of 33 hydrogen bonds engaging the couples phosphonic acid-guanidinium and phosphonic acid-phosphonic acid. Solid-State MAS NMR of the sensitive 31P nucleus in this supramolecular arrangement is used in order to develop alternative analytical method to get information on supra-molecular assemblies. 31P through-space single quantum – double quantum correlation experiments have been performed leading to two possible assignments of the 6 crystallographic P sites to the corresponding resonances in the 1D 31P MAS NMR spectrum.

Among the non-nucleoside reverse transcriptase inhibitors, 1-[2-hydroxyethoxy-methyl]-6-(phenylthio) thymine (HEPT) derivatives have proved to be potent and selective inhibitors of human immunodeficiency virus (HIV-1). They are able to completely suppress virus replication in cell cultures. The quantitative structure-activity relationships (QSAR) try to describe the association between biological activities of a group of congeners and their molecular descriptors. In this paper, recent works on the application of neural networks (NN) and multiple regression analyses to quantitative structure-anti-HIV activity of HEPT derivatives are reviewed. NN have their origins in efforts to reproduce computer models of the information processing that takes place in the brain. They have found application in a wide variety of fields, such as image analysis of facial features, stock market predictions, etc. Application of the NN methods to problems in chemistry and biochemistry has rapidly gained popularity in recent years. We briefly describe a methodology for designing NN for QSAR and estimating their performances, and apply this approach to the prediction of anti-HIV activity of HEPT. The predictive power of the NN used is compared with that of other statistical methods.

A nonlinear quantitative structure−anti-HIV-1-activity relationship (QSAR) study was investigated in a series of 1-2-hydroxyethoxy-methyl-6-(phenylthio) thymine (HEPT) derivatives acting as nonnucleoside reverse transcriptase inhibitors (NNRTIs). This QSAR study has been undertaken by a three-layered neural network (NN) using molecular descriptors known to be responsible for the anti-HIV-1 activity. The usefulness of the model and the nonlinearity of the relationship between molecular descriptors and anti-HIV-1 activity have been clearly demonstrated. The obtained model outperforms those given in the literature in both the fitting and predictive stages. NN analysis yielded predicted activities in excellent agreement with the experimentally obtained values (R2 0.977, predictive r2 0.862). The effect of each molecular feature on the anti-HIV-1 activity variation has been clearly elucidated.

Two cobalt phosphonates containing trifunctional phosphonate anions have been synthesised and their structures solved by single crystal diffraction. Co₃(O₃PCH₂NH₂CH₂PO₃)₂ (3) was formed as blue crystals. The material has three channel systems in the [001] direction formed by the cross-linking of chains of tetrahedrally co-ordinated Co atoms. Co₃(O₃PCH₂-NC₄H₇-CO₂)₂·5H₂O (4), which contains anions derived from proline, was formed as purple crystals. (4) is composed of layers that contain holes. The layers stack in the [001] direction such that channels are formed in the same direction, in which the water molecules are located.

In this paper, we are interested in finding the optimal shape of a magnet. The criterion to maximize is the jump of the electromagnetic field between two different configurations. We prove existence of an optimal shape into a natural class of domains. We introduce a quasi-Newton type algorithm which moves the boundary. This method is very efficient to improve an initial shape. We give some numerical results.

The synthesis and the solid-state structure of benzene-tris-(methylene-phosphonic acid) is reported in the following article. Surprisingly the three methylenephosphonic acid groups are located on the same side of the benzene ring leading to the formation of an octopus shaped molecule. Furthermore the number of proton per phosphonic acid function is different from the expected value of two per phosphophonic acid function. The single crystal X-ray diffraction reveals that this interesting behaviour arises from the formation of a dimer in the solid-state. Interestingly both charge-assisted hydrogen bonds and hydrogen bonds are observed in this dimer.

Extension in an oceanic rift domain is accommodated by fissuring and faulting processes. The fissuring, including dike injection, involves extension and an increase in crustal volume, consistent with magma supply, as in oceanic ridge and hot spot contexts. The faulting mainly involves thinning and extension. The relationship between these two deformation modes is analysed in the northern rift of Iceland. In the active rift zone, deformation and volcanism occur within 2–3-km-wide fissure swarms separated by 10-km-wide zones where deformation is minor. Based on topographic and geological mapping, the local structure in a major fissure swarm was analysed. The fracture density increases near the faults, but also beyond their tips. The geometrical analysis of structures revealed that for the last 10,000years, block faulting and tilting accommodated about one half of the extension, the other half resulting from fissuring. This distribution shows that even in an active volcanic zone with widespread magmatism, the stretching resulting from normal shear can play an important role. As estimated from the ages of eroded surfaces and lava flows, the deformation rates range between 1.5 and 15cm/year. These values are compared with other rates estimated for different time intervals in the same area.

Apomine (SR-45023A) is a new antineoplastic compound which is currently in clinical trials and representative of the family of cholesterol synthesis inhibitors 1,1-bisphosphonate esters. Apomine inhibits growth of a wide variety of tumor cell lines with IC50 values ranging from 5 to 14 μM. The antiproliferative activity of apomine was studied in comparison with that of other inhibitors of the mevalonate/isoprenoid pathway of cholesterol synthesis, simvastatin, farnesol, and 25-hydroxycholesterol. All these compounds inhibit 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity. Apomine (IC50 = 14 μM), simvastatin (IC50 = 3 μM), farnesol (IC50 = 60 μM), and 25-hydroxycholesterol (IC50 = 2 μM) inhibited HL60 cell growth. Growth inhibition due to simvastatin was reverted by mevalonate, whereas the antiproliferative activity of apomine, farnesol, and 25-hydroxycholesterol was not. Apomine triggered apoptosis in HL60 cells in less than 2 h. Apomine and farnesol induced caspase-3 activity at concentrations similar to their IC50 values for cell proliferation, whereas a 10-fold excess of simvastatin was necessary to trigger apoptosis compared to its potency on proliferation. Caspase-3 activity was not induced by 25-hydroxycholesterol. The overall similar profile on mevalonate synthesis inhibition, cell growth inhibition, and apoptosis suggests that apomine acts as a synthetic mimetic of farnesol.