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Effective Route (effective + route)
Selected AbstractsChemInform Abstract: An Efficient One-Pot Synthesis of Tethered Cyclohexadiene Enaminonitriles from Methyl-Ketones: An Effective Route to Quinazolines.CHEMINFORM, Issue 42 2008Bennie J. Bench Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Inter- and Intramolecular Crotyltitanation of Acetals: A Novel and Effective Route to Three- to Five-Membered Vinylcycloalkanes and Bicyclic Fused Compounds.CHEMINFORM, Issue 1 2001Nadine Thery Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Pseudomonas fluorescens orchestrates a fine metabolic-balancing act to counter aluminium toxicityENVIRONMENTAL MICROBIOLOGY, Issue 6 2010Joseph Lemire Summary Aluminium (Al), an environmental toxin, is known to disrupt cellular functions by perturbing iron (Fe) homeostasis. However, Fe is essential for such metabolic processes as the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, the two pivotal networks that mediate ATP production during aerobiosis. To counter the Fe conundrum induced by Al toxicity, Pseudomonas fluorescens utilizes isocitrate lyase and isocitrate dehydrogenase-NADP dependent to metabolize citrate when confronted with an ineffective aconitase provoked by Al stress. By invoking fumarase C, a hydratase devoid of Fe, this microbe is able to generate essential metabolites. To compensate for the severely diminished enzymes like Complex I, Complex II and Complex IV, the upregulation of a H2O-generating NADH oxidase enables the metabolism of citrate, the sole carbon source via a modified TCA cycle. The overexpression of succinyl-CoA synthetase affords an effective route to ATP production by substrate-level phosphorylation in the absence of O2. This fine metabolic balance enables P. fluorescens to survive the dearth of bioavailable Fe triggered by an Al environment, a feature that may have potential applications in bioremediation technologies. [source] Template Deformation-Tailored ZnO Nanorod/Nanowire Arrays: Full Growth Control and Optimization of Field-EmissionADVANCED FUNCTIONAL MATERIALS, Issue 19 2009Haibo Zeng Abstract Here, a facile and effective route toward full control of vertical ZnO nanorod (NR)/nanowire (NW) arrays in centimeter-scale areas and considerable improvement of field-emission (FE) performance is reported. Controlled deformation of colloidal crystal monolayer templates is introduced by heating near glass-transition temperature. The NR/NW density, uniformity, and tapering were all adjusted through selection of template size and deformation, and electrolyte composition. In line with the adjustments, the field-emission performance of the arrays is significantly improved. A low turn-on electric field of 1.8,V µm,1, a field-enhancement factor of up to 5,750, and an emitting current density of up to 2.5,mA cm,2 were obtained. These improved parameters would benefit their potential application in cold-cathode-based electronics. [source] Aqueous-Processable Noncovalent Chemically Converted Graphene,Quantum Dot Composites for Flexible and Transparent Optoelectronic FilmsADVANCED MATERIALS, Issue 5 2010Xiumei Geng The preparation and optoelectronic response of flexible composites via noncovalent coupling of quantum dots to chemically converted graphene is presented. The photoinduced charge transfer is confirmed by photoconductivity measurements and the photosensitivity is improved with increasing loadings of quantum dots. This opens up a new effective route to form composites for future large-area flexible and transparent optoelectronic devices. [source] Self-Assembly of Ordered Patterns: Stressed Triangular Tessellations and Fibonacci Parastichous Spirals on Ag Core/SiO2 Shell Microstructures (Adv. Mater.ADVANCED MATERIALS, Issue 45 200945/2009) Stress engineering offers an effective route for self-assembly of ordered patterns. By stressing Ag core/SiO2 shell microstructures, spontaneous occurrence of triangular tessellations and Fibonacci parastichous spirals can be observed on the spherical and conical cores and shells, respectively. On p. 4652, Ze-Xian Cao and co-workers demonstrate that the stressed patterns are an immediate response to the geometry of the shrinking core/shells. The reproduction of Fibonacci spirals, ubiquitous in the world of plants, on the surface of totally inorganic microstructures provides strong confirmation of the mechanical principle of phyllotaxis. [source] Retention, Distribution, and Effects of Intraosseously Administered Ibandronate in the Infarcted Femoral Head,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2007James Aya-ay Abstract The local distribution, retention, and effects of intraosseous administration of ibandronate in the infarcted femoral heads were studied. Intraosseous administration effectively delivered and distributed ibandronate in the infarcted femoral heads and decreased the femoral head deformity in a large animal model of Legg-Calve-Perthes disease. Introduction: Bisphosphonate therapy has gained significant attention for the treatment of ischemic osteonecrosis of the femoral head (IOFH) because of its ability to inhibit osteoclastic bone resorption, which has been shown to contribute to the pathogenesis of femoral head deformity. Because IOFH is a localized condition, there is a need to explore the therapeutic potential of local, intraosseous administration of bisphosphonate to prevent the femoral head deformity. The purpose of this study was to investigate the distribution, retention, and effects of intraosseous administration of ibandronate in the infarcted head. Materials and Methods: IOFH was surgically induced in the right femoral head of 27 piglets. One week later, a second operation was performed to inject 14C-labeled or unlabeled ibandronate directly into the infarcted head. 14C-ibandronate injected heads were assessed after 48 h, 3 weeks, or 7 weeks later to determine the distribution and retention of the drug using autoradiography and liquid scintillation analysis. Femoral heads injected with unlabeled ibandronate were assessed at 7 weeks to determine the degree of deformity using radiography and histomorphometry. Results: Autoradiography showed that 14C-Ibandronate was widely distributed in three of the four heads examined at 48 h after the injection. Liquid scintillation analysis showed that most of the drug was retained in the injected head, and almost negligible amount of radioactivity was present in the bone and organs elsewhere at 48 h. At 3 and 7 weeks, 50% and 30% of the 14C-drug were found to be retained in the infarcted heads, respectively. Radiographic and histomorphometric assessments showed significantly better preservation of the infarcted heads treated with intraosseous administration of ibandronate compared with saline (p < 0.001). Conclusions: This study provides for the first time the evidence that local intraosseous administration is an effective route to deliver and distribute ibandronate in the infarcted femoral head to preserve the femoral head structure after ischemic osteonecrosis. In a localized ischemic condition such as IOFH, local administration of bisphosphonate may be preferable to oral or systemic administration because it minimizes the distribution of the drug to the rest of the skeleton and bypasses the need for having a restored blood flow to the infarcted head for the delivery of the drug. [source] Vehicles for oligonucleotide delivery to tumoursJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 1 2002Crispin R. Dass The vasculature of a tumour provides the most effective route by which neoplastic cells may be reached and eradicated by drugs. The fact that a tumour's vasculature is relatively more permeable than healthy host tissue should enable selective delivery of drugs to tumour tissue. Such delivery is relevant to carrier-mediated delivery of genetic medicine to tumours. This review discusses the potential of delivering therapeutic oligonucleotides (ONs) to tumours using cationic liposomes and cyclodextrins (CyDs), and the major hindrances posed by the tumour itself on such delivery. Cationic liposomes are generally 100,200 nm in diameter, whereas CyDs typically span 1.5 nm across. Cationic liposomes have been used for the introduction of nucleic acids into mammalian cells for more than a decade. CyD molecules are routinely used as agents that engender cholesterol efflux from lipid-laden cells, thus having an efficacious potential in the management of atherosclerosis. A recent trend is to employ these oligosaccharide molecules for delivering nucleic acids in cells both in-vitro and in-vivo. Comparisons are made with other ON delivery agents, such as porphyrin derivatives (< 1 nm), branched chain dendrimers (, 10 nm), polyethylenimine polymers (, 10 nm), nanoparticles (20,1000 nm) and microspheres (> 1 ,m), in the context of delivery to solid tumours. A discourse on how the chemical and physical properties of these carriers may affect the uptake of ONs into cells, particularly in-vivo, forms a major basis of this review. [source] Dispersion polymerization of vinyl monomers in supercritical carbon dioxide in the presence of drug molecules: A one-pot route for the preparation of controlled delivery systemsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2008Alessandro Galia Abstract The polymerization of 1-vinyl-2-pyrrolidone in supercritical carbon dioxide in the presence of ibuprofen as a model drug was investigated as a new one-pot process for the preparation of polymer-based drug delivery systems (DDSs). The composites were prepared at 65 °C and P = 31,42 MPa by changing the initial concentration of the drug and the concentration of a crosslinking agent and that of a hydrophobic comonomer. The effects of these parameters on the performances of the polymerization and on the in vitro release kinetics of ibuprofen were studied. In all the experiments, part of the drug was entrapped inside the polymer particles and dissolved more slowly with respect to the pure compound. Copolymerization with methyl methacrylate was the most effective route to obtain a DDS with sustained temporal release of the drug molecule. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7429,7446, 2008 [source] Synthesis of new amphiphilic diblock copolymers containing poly(ethylene oxide) and poly(,-olefin)JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2002Yingying Lu Abstract This article discusses an effective route to prepare amphiphilic diblock copolymers containing a poly(ethylene oxide) block and a polyolefin block that includes semicrystalline thermoplastics, such as polyethylene and syndiotactic polystyrene (s-PS), and elastomers, such as poly(ethylene- co -1-octene) and poly(ethylene- co -styrene) random copolymers. The broad choice of polyolefin blocks provides the amphiphilic copolymers with a wide range of thermal properties from high melting temperature ,270 °C to low glass-transition temperature ,,60 °C. The chemistry involves two reaction steps, including the preparation of a borane group-terminated polyolefin by the combination of a metallocene catalyst and a borane chain-transfer agent as well as the interconversion of a borane terminal group to an anionic (O,K+) terminal group for the subsequent ring-opening polymerization of ethylene oxide. The overall reaction process resembles a transformation from the metallocene polymerization of ,-olefins to the ring-opening polymerization of ethylene oxide. The well-defined reaction mechanisms in both steps provide the diblock copolymer with controlled molecular structure in terms of composition, molecular weight, moderate molecular weight distribution (Mw/Mn < 2.5), and absence of homopolymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3416,3425, 2002 [source] Cu[Al(ORF)4] Starting Materials and their Application in the Preparation of [Cu(Sn)]+ (n=12, 8) ComplexesCHEMISTRY - A EUROPEAN JOURNAL, Issue 27 2009Gustavo Santiso-Quiñones Dr. Abstract Naked copper,? A newly developed simple two-step route to weakly coordinated CuI starting materials that were used to prepare novel copper,cyclosulfur adducts, including the first M+,S12 complex (see figure, RF= C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2). Reactions with the [Al{OC(CF3)3}4], counterion mimic gas-phase chemistry inside a mass spectrometer (to form [Cu(S12)]+). An effective route to stable, almost-"naked" CuI salts of weakly coordinating anions (WCAs) of the type [Al(ORF)4], has been developed. Born,Fajans,Haber cycles and theoretical calculations suggest that this methodology is useful for the generation of CuI salts regardless of the larger WCA used. The first homoleptic CuI,arene complex [Cu(1,2-F2C6H4)2]+[Al{OC(CF3)3}4], (1), the first CuI,methylenechloride complex [Cu(CH2Cl2)Al{OC(CH3)(CF3)2}4] (2), and the donor-free dimer [CuAl{OCH(CF3)2}4]2 (3) were synthesized in quantitative yields by sonicating Li[Al(ORF)4] (RF=C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2), AgF, and a three-fold excess of CuI in 1,2-F2C6H4 (1) or CH2Cl2 (2, 3). Substances 1,3 are good starting materials for further CuI chemistry, and the reaction of 1,3 with the weak Lewis base cyclooctasulfur gave the first CuI,sulfur complexes of type [Cu(S12)(S8)]+[Al{OC(CF3)3}4], (4), [Cu(CH2Cl2)(S12)]+[Al{OC(CF3)3}4], (5), [A1Cu(1,5-,1,,1 -S8)CuA1] (6; A1=[Al{OC(CH3)(CF3)2}4],), and a CuI,S8 1D coordination polymer with [Cu2(S8)2A22] (7; A2=[Al{OCH(CF3)2}4],), as a monomeric repeat unit. Complexes 4 and 5 are the first example of any metal coordinated to cyclo-S12 and 4 is the first example of a complex having an element in two allotropic modifications as a ligand. [source] Study on Synthesis and Electrochemical Properties of Nanophase Li-Mn-spinelCHINESE JOURNAL OF CHEMISTRY, Issue 3 2003Feng Chuan-Qi Abstract Li-Mn-spinel was synthesized using the rheological phase reaction method. First, the precursor was prepared by rheological phase reaction. Then it was decomposed to form Li-Mn-spinel, which was characterized by X-ray diffraction analysis and IR spectra. The particle size of Li-Mn-spinel was determined by the method of the transmission electron microscopy. The synthesized materials are of nanometer size with 30,100 nm in the average diameter. The electrochemical properties of the Li-Mn-spinel were also studied. It proved that this method not only provided a simple practicable and effective route for the synthesis of Li-Mn-spinel, but also had many advantages such as lower sintering temperature, shorter sintering time, fine particles and particularly excellent electrochemical performances. [source] | ||||||||||||||||