Mechanical and Aerospace Engineering, ICMAE2011: Molecular and Electronic Structure of 1-Naphtol : |i|Ab Initio|/i| Molecular Orbital and Density Functional Study
The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated β-substituted-α,β-unsaturated esters catalyzed by a bifunctional iminophosphorane (BIMP) organocatalyst is described. The low acidity of the alkyl thiol pro-nucleophiles is overcome by the high Brønsted basicity of the catalyst ISACS19: Challenges in Organic Chemistry
The direct formation of hydrogen peroxide from H2 and O2 was successfully carried out in a capillary microreactor at room temperature and atmospheric pressure. A key element in sustaining the activity of the catalyst is the incarceration of the palladium nanoparticles in a cross-linkable amphiphilic polystyrene-based polymer, prepared following the protocol of Kobayashi [R. Akiyama, S. Kobayashi, J. Am. Chem. Soc. 125 (2003) 3412-3413]. The immobilization effectively reduced the leaching of palladium under acidic conditions. Applying the catalyst as a coating on the inner walls of a capillary enabled the sustained production of 1.1% hydrogen peroxide over at least 11 days. The highest catalyst utilization in a 2 mm capillary reactor was 0.54 molH2O2/h gPd. When the inner diameter of the reactor capillary was reduced to 530 μm, the rate was enhanced fourfold to 2.28 molH2O2/h gPd corresponding to a turnover frequency of 0.067 s-1. © 2009 Elsevier Inc. All rights reserved ...
Ab initio molecular orbital studies show that bromonium ion intermediate is more stable than the intermediate in reaction 1(structure-(10)).. In the addition of HBr to bromoethene, it follows the convention: "the electrophile attacks the substrate before the nucleophile does". Electrophile need not actually be a positive ion but can be the positive end of a dipole or an induced dipole, with the negative part breaking off either during the first step or shortly after. So, the formation of the carbocation after the attack of the proton is inevitable. But due to the fact that in reaction 1, the electrophile is hydrogen ion, the reaction takes place through the mechanism involving structure (10) and not the one in reaction 2 involving the bromonium ion intermediate(9).. I hope you realize that (2) never forms (4). Your statement saying that (4) forms (3) interconvert among themselves is not correct rather (3) and (4) are separate species formed through different set of mechanisms. None of the ...
Ab initio molecular orbital studies show that bromonium ion intermediate is more stable than the intermediate in reaction 1(structure-(10)).. In the addition of HBr to bromoethene, it follows the convention: "the electrophile attacks the substrate before the nucleophile does". Electrophile need not actually be a positive ion but can be the positive end of a dipole or an induced dipole, with the negative part breaking off either during the first step or shortly after. So, the formation of the carbocation after the attack of the proton is inevitable. But due to the fact that in reaction 1, the electrophile is hydrogen ion, the reaction takes place through the mechanism involving structure (10) and not the one in reaction 2 involving the bromonium ion intermediate(9).. I hope you realize that (2) never forms (4). Your statement saying that (4) forms (3) interconvert among themselves is not correct rather (3) and (4) are separate species formed through different set of mechanisms. None of the ...
Gaussian performs semiempirical and ab initio molecular orbital (MO), density functional, and molecular mechanics calculations. To use this program at MSI, please send a request to [email protected] and ask to be added to the Gaussian group. To use Gaussian 09, you need to be a researcher at the Twin Cities campus. MSI is in the process of deprecating some older, unused versions of Gaussian. Below is a list of modules that are slated for removal, and for each, a corresponding supported module. If you are using one of the deprecated modules, please transition to the listed supported module ...
The equilibrium geometries, binding energies, and electronic structure of neutral FeC n (n≤3) clusters have been calculated self‐consistently using ab initio molecular orbital theory. The exchange and correlation contributions to the total energy were computed using both the density functional method (with and without nonlocal correction) as well as the Hartree-Fock-Möller-Plesset theory. All levels of theory predict the equilibrium geometries to be cyclic. The binding energies, bond lengths, and the Mulliken charges obtained from both methods of calculations are also in agreement. The results are compared with recent mobility and photoelectron spectroscopy experiments.
Limiting mutual diffusion coefficients of aromatic compounds in acetone have been measured at 298.2 K by using the chromatographic peak-broadening method. The data of the polar and nonpolar pseudoplanar solutes are compared, and the effects of molecular association on diffusion as well as the solvation numbers are determined. It is found that the effects of hydrogen bonding are such that â€"OH>â€"NH2>â€"SH, and that the solvation numbers are approximately equal for solutes containing the same polar group. Using ab initio molecular orbital theory, molecular soluteâ€"acetone interaction energies have been calculated. There exists a nearly linear relationship between the interaction energy and the effect of soluteâ€"solvent association on diffusion. The applicability of the rough-hard-sphere theory to the diffusion of associated molecules is discussed. © 1997 American Institute of Physics ...
|p|The Wittig reaction of carbaldehydes with alkoxycarbonylhalomethylidenetriphenylphosphoranes can be performed with ease in solventless systems. The analogous reaction of carbaldehydes with acylhalomethylidenetriphenylphosphoranes requires a small amount of solvent, such as chloroform, in order for the reaction to proceed. The products of the reaction are versatile precursors for further transformations, such as the Suzuki-Miyaura cross-coupling reaction.|/p|
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database ...
Polymerases uses a two-metal ion mechanism to carry out the addition of a new NTP to a growing RNA strand. Two Mg2+ ions are used in this process; metal ion A is involved in the formation of the nucleophile (O-) for the SN2 reaction to occur and metal ion B is involved in the stabilization of the transition state in the reaction. For the addition of a NTP to a RNA strand to occur, an activated 3 hydroxyl group (O-) acts a nucleophile and attacks the alpha phosphate of the incoming NTP. The reaction is initiated by a deprotonation event. Metal ion A aids with this deprotonation as it reduces the pKa of the hydroxyl (so it is more acidic), making it easier to deprotonate and form the nucleophile, the proton is accepted by a nearby aspartate residue (not water) - doi: 10.1021/ja403842j. After the hydroxyl attack, the mechanism proceeds through a pentacovalent transition state like in a standard Sn2 reaction and the pyrophosphate group (PPi) is kicked out. The image is not mine but comes from this ...
The iminophosphorane Ph2MePdouble bond; length as m-dashNPh (1) reacts with Pd(OAc)2 to give the orthopalladated [Pd(μ-Cl){C6H4(PPh(Me)double bond; length as m-dashNPh-κ-C,N)-2}]2 (2) as the racemic mixture, which reacts with Tl(acac) to give [Pd(acac){C6H4(PPh(Me)double bond; length as m-dashNPh-κ-C,N)-2}] (3). The X-ray structure of (3) has been determined by diffraction methods. The phosphorus ylide Ph2MePdouble bond; length as m-dashCHC(O)Ph (5) reacts with Pd(OAc)2 to give the dinuclear [Pd(μ-Cl){C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}]2 (6) as a mixture of isomers. Complex (6) reacts with Tl(acac), PPh3 or AgClO4/dppe giving the mononuclear derivatives [Pd(acac){C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}] (7), [PdCl{C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}PPh3] (8) and [Pd{C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}(dppe-P,P′)](ClO4) (9), as mixtures of stereoisomers with high diastereomeric excess ...
A synergistic combination of copper and chiral amine catalysis enables an enantioselective α-alkenylation of aldehydes using boronic acids. The merger of two highly utilized and robust catalytic systems has allowed for the development of a mild and operationally trivial protocol for the direct formation of α-formyl olefins employing common building blocks for organic synthesis ...
A novel strategy is presented for sensitive detection of alfa-fetoprotein (AFP), using a horseradish peroxidase (HRP)-functionalized Envision antibody complex (EVC) as the label. The Envision-AFP signal antibody copolymer (EVC-AFP Ab2) was composed of a dextran amine skeleton anchoring more than 100 molecules of HRP and 15 molecules of secondary antibody, and acted as a signal tag in the immunosensor. The sensor was constructed using the following steps: First, gold electrode (GE) was modified with nano-gold (AuNPs) by electro-deposition in HAuCl4 solution. The high affinity of the AuNPs surface facilitates direct formation of a self-assembled thiolated protein G layer. Next, the coated GE was incubated in a solution of AFP capture antibody (AFP Ab1); these antibodies attach to the thiolated protein G layer through their non-antigenic regions, leaving the antigen binding sites for binding of target analyte. Following a sandwich immunoreaction, an EVC-AFP Ab2-AFP-AFP Ab1 immunocomplex was formed on the
TY - JOUR. T1 - Characterization of hydrogen-terminated CVD diamond surfaces and their contact properties. AU - Kawarada, Hiroshi. AU - Aoki, M.. AU - Sasaki, H.. AU - Tsugawa, K.. PY - 1994. Y1 - 1994. N2 - Metal-diamond contact properties have been investigated on diamond (001) 2 × 1 surfaces. The 2 × 1 reconstruction has been examined by atomic-scale scanning tunnelling microscopy. From ab initio molecular orbital calculations, the stablest structure of the 2 × 1 unit is a monohydride carbon dimer. On the surfaces the highest quality Schottky diodes have been fabricated using metals with lower electronegativities. The Schottky barrier heights depend on the metal electronegativity. Moreover ohmic contacts have been obtained in metals with higher electronegativities. These results indicate that the surface states are effectively reduced by the 2 × 1 surface reconstruction.. AB - Metal-diamond contact properties have been investigated on diamond (001) 2 × 1 surfaces. The 2 × 1 ...
Trifluridine (FTD), known as main component of TAS-102, is beginning to be applied as anti-tumor agent due to the highly efficacious antitumor potency although there is little to distinguish FTD structure from thymidine structure. TAS-102 has first been used in Japan in clinical therapy as an oral agent. Some experimental results hypothesized that FTD pharmacological antitumor effect can be arisen by inhibition of thymidylate synthase and incorporation of FTD itself into DNA. One of them is the thermal denaturation experiments for DNA duplexes of containing some FTD or not, performed by J. C. Markley et al. Their experiments have shown that the DNA duplexes containing FTD are slightly less stable, with a melting temperature about three degrees lower than not containing duplexes. However, the change of thermodynamic structure and inter-nucleobase interaction changes are not yet known.. In this presentation, we have performed molecular dynamics (MD) simulations and ab initio molecular orbital (MO) ...
Organogold chemistry is the study of compounds containing gold-carbon bonds. They are studied in academic research, but have not received widespread use otherwise. The dominant oxidation states for organogold compounds are I with coordination number 2 and a linear molecular geometry and III with CN = 4 and a square planar molecular geometry. The first organogold compound discovered was gold(I) carbide Au2C2, which was first prepared in 1900. Gold(I) complexes are 2-coordinate, linear, diamagnetic, 14 electron species. They typically exist as adducts LAuR with as ligand L for instance a triphenylphosphine or an isocyanide. The ligand prevents reduction of Au(I) to metallic Au(0) with dimerization of the organic residue. Gold(I) can also exist as the aurate M[AuR2] (the ate complex) whereby the cation is usually fitted with a complexing agent to improve stability. The AuR2− anion is also linear just as other M(d10) species such as Hg(Me)2 and Pd(Me)22+. Gold is known to form acetylides (capable ...
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database ...
Sewald, N. (1996). Stereoselective Synthesis of beta-Amino Acids via Conjugate Addition of Nitrogen Nucleophiles to alpha,beta-Unsaturated Esters - Recent Advances. Amino Acids, 11(3), 397-408. doi:10.1007/ ...
Triphosphorus pentanitride is an inorganic compound with the chemical formula P3N5. Containing only phosphorus and nitrogen, this material is classified as a binary nitride. No applications have been developed for this material, which remains a topic of research. It is a white solid, although samples often appear colored owing to impurities. Triphosphorus pentanitride can be produced by reactions between various phosphorus(V) and nitrogen compounds (such as ammonia and sodium azide); including a reaction between the elements. 3 PCl5 + 5 NH3 → P3N5 + 15 HCl 3 PCl5 + 15 NaN3 → P3N5 + 15 NaCl + 5 N2 Similar methods are used to prepared boron nitride (BN) and silicon nitride (Si3N4); however the products are generally impure and amorphous. Crystalline samples have been produced by the reaction of ammonium chloride and hexachlorocyclotriphosphazene: or phosphorus pentachloride. (NPCl2)3 + 2 NH4Cl → P3N5 + 8 HCl 3 PCl5 + 5 NH4Cl → P3N5 + 20 HCl P3N5 has also been prepared at room temperature, ...
TY - JOUR. T1 - Bonding in the syn and anti isomers of di-μ-sulfido-bis(sulfido(1,2-dimercaptoethanato)molybdate(V)) anions. AU - Chandler, Travis. AU - Lichtenberger, Dennis L. AU - Enemark, John H.. PY - 1981. Y1 - 1981. N2 - The electronic structure and bonding interactions in the syn, anti, and closed isomers of [Mo2S4(S2C2H4) 2]2- are examined and compared through extended Hückel and Fenske-Hall molecular orbital calculations. A molybdenum-molybdenum bonding interaction is found to account for the diamagnetism of the complexes and to be important in determining the relative stability of the isomers. The predicted stabilities are syn , closed , anti.. AB - The electronic structure and bonding interactions in the syn, anti, and closed isomers of [Mo2S4(S2C2H4) 2]2- are examined and compared through extended Hückel and Fenske-Hall molecular orbital calculations. A molybdenum-molybdenum bonding interaction is found to account for the diamagnetism of the complexes and to be important in ...
The present research addressed the size-controlled synthesis of ZnO nanocrystals at different temperatures. In order to study systematically the dependence of crystal size with synthesis conditions in ethanol, stable suspensions of these nanocrystals were produced at various temperatures, ranging from 0 0C to 60 0C. XRD characterization of produced materials verified the fast and direct formation of ZnO nanocrystals. In XRD pattern the absence of peaks other than those corresponding to ZnO, suggests well and fast formation of the oxide structure even without aging. Moreover, the XRD patterns show a significant shift in the peaks position, which is evidence of a progressive increment in their lattice parameters. The FT-IR spectra of ZnO crystals synthesized at 00C and aged for different times, show bands at 525cm,1 which is attributed to stretching vibrations of the Zn-O bonds. The bands at 1339, 1404, and 1575 cm-1, are due to the stretching vibration of C=O, C=C and C-H bonds, respectively. The high
2-Methyl-3-[(2-phenyl-1H-indol-3-yl)methyl]quinazolin-4-one/ACM88514481 can be provided in Alfa Chemistry. We are dedicated to provide our customers the best products and services.
2-(5,6-Dihydro-benzimidazo[1,2-c]quinazolin-6-yl)phenol.: The asymmetric unit of the title compound, C(20)H(15)N(3)O, contains two independent mol-ecules, each
3-(2-(pyrrolidin-1-yl)ethoxy)-1,10b-dihydro-(1,2,4)triazolo(1,5-c)quinazolin-5(6H)-one: putative antineoplastic agent that activates p53-mediated transcriptional activity
85736-43-2 - Amines, N-C12-18-alkylhexamethylenedi-, acetates - Searchable synonyms, formulas, resource links, and other chemical information.
Applies To: SQL Server 2016 Preview. To create a data mining model, you must first use the Data Mining Wizard to create a new mining structure based on the new data source view. In this task you will use the wizard to create a mining structure, and at the same time create an associated mining model that is based on the Microsoft Neural Network algorithm.. Because neural networks are extremely flexible and can analyze many combinations of inputs and outputs, you should experiment with several ways of processing the data to get the best results. For example, you might want to customize the way that the numerical target for service quality is binned, or grouped, to target specific business requirements. To do this, you will add a new column to the mining structure that groups numerical data in a different way, and then create a model that uses the new column. You will use these mining models to do some exploration.. Finally, when you have learned from the neural network model which factors have the ...
Fujitsu Laboratories today announced, as a world first, the development of a novel technology for forming graphene transistors directly on the entire surface of large-scale insulating substrates at low temperatures while ...
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TY - JOUR. T1 - The wacker process. T2 - Inner- Or outer-sphere nucleophilic addition? New insights from Ab initio molecular dynamics. AU - Comas-Vives, Aleix. AU - Stirling, András. AU - Lledós, Agustí. AU - Ujaque, Gregori. PY - 2010/8/2. Y1 - 2010/8/2. N2 - The Wacker process consists of the oxidation of ethylene catalyzed by a PdII complex. The reaction mechanism has been largely debated in the literature; two modes for the nucleophilic addition of water to a Pd-coordinated alkene have been proposed: syninner- and anti-outer-sphere mechanisms. These reaction steps have been theoretically evaluated by means of ab initio molecular dynamics combined with metadynamics by placing the [Pd-(C2H 4)Cl2(H2O)] complex in a box of water molecules, thereby resembling experimental conditions at low [Cl-]. The nucleophilic addition has also been evaluated for the [Pd(C 2H4)Cl3]- complex, thus revealing that the water by chloride ligand substitution trans to ethene is kinetically favored over the ...
Towards more realistic molecular modeling of catalysis with density functional theory: Combined QM/MM and ab initio molecular dynamics ...
The activation, hydrogenation, and covalent coupling of polycyclic aromatic hydrocarbons (PAHs) are processes of great importance in fields like chemistry, energy, biology, or health, among others. So far, they are based on the use of catalysts which drive and increase the efficiency of the thermally- or light-induced reaction. Here, we report on the catalyst-free covalent coupling of nonfunctionalized PAHs adsorbed on a relatively inert surface in the presence of atomic hydrogen. The underlying mechanism has been characterized by high-resolution scanning tunnelling microscopy and rationalized by density functional theory calculations. It is based on the formation of intermediate radical-like species upon hydrogen-induced molecular superhydrogenation which favors the covalent binding of PAHs in a thermally activated process, resulting in large coupled molecular nanostructures. The mechanism proposed in this work opens a door toward the direct formation of covalent, PAH-based, bottom-up ...
The mechanisms involved in radiation-induced cellular injury and death remain incompletely understood. In addition to the direct formation of highly reactive hydroxyl radicals (HO.) by radiolysis of water, oxidative stress events in the cytoplasm due to formation of H2O2 may also be important. Since the major pool of low-mass redox-active intracellular iron seems to reside within lysosomes, arising from the continuous intralysosomal autophagocytotic degradation of ferruginous materials, formation of H2O2 inside and outside these organelles may cause lysosomal labilization with release to the cytosol of lytic enzymes and low-mass iron. If of limited magnitude, such release may induce reparative autophagocytosis, causing additional accumulation of redox-active iron within the lysosomal compartment. We have used radio-resistant histiocytic lymphoma (J774) cells to assess the importance of intralysosomal iron and lysosomal rupture in radiation-induced cellular injury. We found that a 40 Gy ...
A new silver-mediated 5-exo-dig cyclization of 2-alkynylbenzonitriles with disubstituted phosphine oxide and H2O has been developed. The reaction enables multiple bond-forming events including C-P, C-C and C-O bonds under atmospheric conditions, leading to the concise and direct formation of 28 examples of p
With more than 35 years of experience, most recently as founder of the literary management agency D.C. Jacobson and Associates, Don Jacobson has been named senior v-p and books group publisher for HarperCollins Christian Publishing and its affiliate, HarperCollins Focus.
Synthesis of 2-[2-(2,6-dichlorophenyl)amino]phenylmethyl-3-[4-(2-substitutedphenyl-4-oxo-thiazolidinyl)aryl]-6-bromo quinazolin-4(3H)ones VIa-j have been achieved from the starting material 2-[(2,6-dichlorophenyl)amino] phenylacetic acid I to benzoxazine III, Further reaction with p-phenylindiamine and substituted aromatic aldehyde gave 2-[2-(2,6-dichlorophenyl)amino]phenyl methyl-3-(4-aminoaryl)-6-bromo quinazolin-4(3H)-ones IV and 2-[2-(2,6-dichlorophenyl)amino]phenylmethyl-3-[4-(2-substituted arylidene)aryl]-6-bromo quinazolin-4(3H)ones Va-j respectively. Va-j on cyclization with thioglycolic acid gave VIa-j. All the synthesized compounds have been characterized on the basis of elemental analysis, IR and 1H-NMR spectral data. They were screened for antibacterial and antifungal activity at two concentrations and compared with the standard drugs penicillin-G, ampicillin, and amoxicillin. The compounds containing 4-OCH3 and 3, 4, 5-(OCH3)3 showed good activity, compared with the standard drugs.
0054]In accordance with the foregoing the present invention further provides: [0055]a pharmaceutical composition comprising the crystal of the invention, e.g. 3-(1.H.-indol-3-yl)-4-[2-(4-methyl-piperazin-1-yl)-quinazolin-4-yl]-pyrro- le-2,5-dione acetate in amorphous form, crystalline form, e.g. Form A or Form B, or pseudocrystalline form, e.g. Form SA together with at least one pharmaceutically acceptable carrier or diluent; [0056]the crystals of the invention, e.g. 3-(1.H.-indol-3-yl)-4-[2-(4-methyl-piperazin-1-yl)-quinazolin-4-yl]-pyrro- le-2,5-dione acetate in amorphous, crystalline or pseudocrystalline form, e.g. Form A, B, C, D or SA, preferably Form A, B or mixture thereof for use as a pharmaceutical; [0057]the crystals of the invention, e.g. 3-(1.H.-indol-3-yl)-4-[2-(4-methyl-piperazin-1-yl)-quinazolin-4-yl]-pyrro- le-2,5-dione acetate in amorphous, crystalline or pseudocrystalline form, e.g. Form A, B, C, D or SA, preferably Form A, B or mixture thereof, for use in the preparation of a ...
In contrast to molecular chaperones that couple protein folding to ATP hydrolysis, protein disulfide-isomerase (PDI) catalyzes protein folding coupled to formation of disulfide bonds (oxidative folding). However, we do not know how PDI distinguishes folded, partly-folded and unfolded protein substrates. As a model intermediate in an oxidative folding pathway, we prepared a two-disulfide mutant of basic pancreatic trypsin inhibitor (BPTI) and showed by NMR that it is partly-folded and highly dynamic. NMR studies show that it binds to PDI at the same site that binds peptide ligands, with rapid binding and dissociation kinetics; surface plasmon resonance shows its interaction with PDI has a Kd of ca. 10−5 M. For comparison, we characterized the interactions of PDI with native BPTI and fully-unfolded BPTI. Interestingly, PDI does bind native BPTI, but binding is quantitatively weaker than with partly-folded and unfolded BPTI. Hence PDI recognizes and binds substrates via permanently or transiently
2-(2H-1,4-Diazepin-5-yl)-N-(2-methylsulfinylethyl)quinazolin-4-amine | C16H17N5OS | CID 54174020 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.
The mechanisms seem to be sequential, but the identity of the individual steps is still being investigated.. DOUBLE PHOTOIONISATION AND SPECTRA OF DOUBLY CHARGED IONS. Molecular dications, such as CO22+, are components of planetary atmospheres and of astrophysical plasmas; they are much less well understood than neutral or singly ionised molecules. We work on how they are formed, their spectra and how they react. A new instrument, being built in the year 2000, will allow us to take the first complete spectra of the two photoelectrons ejected in double photoionistion. As with normal photoelectron spectroscopy, interpretation of the electron energy spectra will allow us to locate the energy levels of the doubly charged ions. These will then be interpreted with the aid of molecular orbital calculations of the electronic structure of these elusive species.. TECHNIQUES AND DEVELOPMENT OF NEW INSTRUMENTS. A major part of the work of the group is development of new instruments to carry out the ...
A fundamental quantum mechanical modelling approach is used for calculating liquid diffusion parameters in cemented carbides. Up to now, no detailed description of diffusion for alloying elements in a liquid Co matrix is available. Neither are experimental measurements found in the literature for the self- or impurity diffusion in the liquid Co system. State of the art application is the description of gradient formation in cemented carbide systems using DICTRA. In this work it is assumed that diffusion during sintering of cemented carbides takes place mainly in the liquid Co binder phase. With this assumption one can calculate the diffusion coefficient for different alloying elements like W, Ti, N and C in a liquid Co matrix phase. The mean square displacement (MSD) of the diffusing atoms is used to obtain the diffusion coefficients which could be simulated by Ab initio Molecular Dynamics (AIMD). By fitting the computed temperature dependence with the Arrhenius relation one can determine the ...
Mitochondrial dysfunction plays a role in a wide range of diseases resulting in an enormous public health burden. The goal of this thesis is to identify metabolic pathways that are disrupted in response to mitochondrial insults. A large proportion of this work is based on the generation of stable isotope labelled metabolites to allow for the rigorous quantification of intracellular metabolites by liquid chromatography-mass spectrometry. Once developed, this methodology was employed in cell culture models initially to characterize an unidentified acyl-CoA thioester induced by propionate metabolism. This novel pathway was identified as the direct formation of 2-methyl-2-pentenoyl-CoA, and using isotopic labeling by metabolic precursors served as a critical component to this pathway elucidation. These same techniques were then applied to studying rotenone, a mitochondrial complex I inhibitor associated with Parkinsonâ??s disease. Previous work by our group has shown that rotenone inhibits components of
Abstract The study of properties of low-dimensional materials is currently one domain of aberration-corrected high-resolution transmission electron microscopy at lower accelerating voltages of 80keV. The susceptibility to radiation damage both challenges the interpretation of the structure at the atomic level and allows at the same time the study of the dynamics of transformations. We report atom-by-atom on the direct formation of structures such as fullerenes, nanoribbons, nanotubes and 2D-layers, which are stimulated by the electron beam and/ or by heat. Moreover, under the influence of the e-beam during its imaging process, the creation and motion of point defects, dislocations, grain boundaries and phase transitions can be observed and allow an unprecedented view into their atomic nature and properties, if combined by atomistic simulations. Imaging the pristine structure of beam-sensitive materials, however, still remains a challenging task. We show that fullerenes inside carbon nanotubes at 20kV
see article for more reactions. Abstract. Molecular iodine catalyzes a metal-free oxidative coupling of 2-aminobenzamides with aryl methyl ketones to yield 2-aryl quinazolin-4(3H)-ones. The selectivity of the reaction strongly depends on the quantity of iodine.. ...
First-principles full-potential linear muffin-tin orbital calculations have been used to study the 4d-transition-metal cal bides ZrC, NbC, and MoC. The experimental phase diagrams at T = 0 of the refractory compounds ZrC, NbC, and MoC have been reproduced with great accuracy from first principles theory. The energy of for marion for these compounds has been calculated for several phases and stoichiometries in order to understand the differences in phase stabilities and the changes in homogeneity ranges found between these systems is explained. The results can be regarded as theoretical zero-temperature phase stability diagrams for the three compounds containing not only the experimentally verified but also hypothetical phases and many of the experimental properties and trends are reproduced and explained. A study of the changes and differences in electronic structure and bonding of the studied compounds, phases and stoichiometries is also presented. As a part of this study the hexagonal Me2C (Me ...
Per-O-acetylated beta-D-glucopyranosyl azide was transformed into an intermediate iminophosphorane by PMe(3) which was then acylated to N-acyl-beta-D-glucopyranosylamines. The same azide and substituted acetylenes gave 1-(beta-D-glucopyranosyl)-4-substituted-1,2,3-triazoles in Cu(I)-catalyzed azide-alkyne cycloadditions. Deprotection of these products by the Zemplen method furnished beta-D-Glc(p)-NHCO-R derivatives as well as 1-(beta-D-Glc(p))-4-R-1,2,3-triazoles which were evaluated as inhibitors of rabbit muscle glycogen phosphorylase b. Pairs of amides versus triazoles with the same R group displayed similar inhibition constants. X-ray crystallographic studies on the enzyme-inhibitor complexes revealed high similarities in the binding of pairs with R = 2-naphthyl and hydroxymethyl, while for the R = Ph and 1-naphthyl compounds a different orientation of the aromatic part and changes in the conformation of the 280s loop were observed. By this study new examples of amide-1,2,3-triazole ...
in Physical Review Letters (2005), 95(26), 2678011-26780142678014. The density anomaly of liquid Ge 0.15Te 0.85 measured between 633 and 733 K is investigated with ab initio molecular dynamics calculations at four temperatures and at the corresponding experimental ... [more ▼]. The density anomaly of liquid Ge 0.15Te 0.85 measured between 633 and 733 K is investigated with ab initio molecular dynamics calculations at four temperatures and at the corresponding experimental densities. For box sizes ranging from 56 to 112 atoms, an 8 k-points sampling of the Brillouin zone is necessary to obtain reliable results. Contrary to other Ge chalcogenides, no sp 3 hybridization of the Ge bonding is observed. As a consequence, the negative thermal expansion of the liquid is not related to a tetrahedral bonding as in the case of water or silica. We show that it results from the symmetry recovery of the local environment of Ge atoms that is distorted at low temperature by a Peierls-like mechanism acting in ...
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Looking for online definition of nucleotidyl in the Medical Dictionary? nucleotidyl explanation free. What is nucleotidyl? Meaning of nucleotidyl medical term. What does nucleotidyl mean?
Research Interests: Research in Progress 1) We have an ongoing research project underway with PhotoKinetics, Inc. (PKI) dealing with the development of products related to the effect of light on the intrinsically photosensitive retinal ganglion cells (ipRGC) of the eye. This work is involving the Hector Olvera of the College of Nursing at UTEP, and discussions have begun with Dr. Kristin Gosselink of the Department of Biology at UTEP. This work also involves entities outside of UTEP, which, for reasons of nondisclosure protection cannot be disclosed at this time. 2) We have a recent incipient research project involving the calculation of the photochemical and radical reaction stability of some small fluorocarbon molecules which may be contaminants in the atmosphere. This project is really the main interest of a student, Jaime Valencia, whom I am assisting by training him how to undertake and interpret the molecular orbital calculations. 3) Ongoing theoretical chemical project in singlet oxygen ...
Make no contact with the spilled material. Fully encapsulating, vapor protective clothing should be worn for spills and leaks with no fire. ELIMINATE all ignition sources and ground all equipment. Stop leak if you can do it without risk. A vapor suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean non-sparking tools to collect absorbed material ...
Using density functional theory and Ab Initio Molecular Dynamics with Electronic Friction (AIMDEF), we study the adsorption and dissipative vibrational dynamics of hydrogen atoms chemisorbed on free-standing lead films of increasing thickness. Lead films are known for their oscillatory behaviour of certain properties with increasing thickness, e.g., energy and electron spillout change in discontinuous manner, due to quantum size effects [G. Materzanini, P. Saalfrank, and P. J. D. Lindan, Phys. Rev. B 63, 235405 (2001)]. Here, we demonstrate that oscillatory features arise also for hydrogen when chemisorbed on lead films. Besides stationary properties of the adsorbate, we concentrate on finite vibrational lifetimes of H-surface vibrations. As shown by AIMDEF, the damping via vibration-electron hole pair coupling dominates clearly over the vibration-phonon channel, in particular for high-frequency modes. Vibrational relaxation times are a characteristic function of layer thickness due to the ...
Biopolymers are easily denatured by heating, a change in pH or chemical substances when they are immobilized on a substrate. To prevent denaturation of biopolymers, we developed a method to trap a polynucleotide on a substrate by hydrogen bonding using silica particles with surfaces modified by aminoalkyl chains ([A-AM silane]/SiO2). [A-AM silane]/SiO2 was synthesized by silane coupling reaction of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (A-AM silane) with SiO2 particles with a diameter of 5 μm at 100 °C for 20 min. The surface chemical structure of [A-AM silane]/SiO2 was characterized by Fourier transform infrared spectroscopy and molecular orbital calculations. The surface of the silica particles was modified with A-AM silane and primary amine groups were formed. [A-AM silane]/SiO2 was trapped with single-stranded nucleic acids [(Poly-X; X = A (adenine), G (guanine) and C (cytosine)] in PBS solution at 37 °C for 1 h. The single-stranded nucleic acids were trapped on the surface of the [A-AM
Directory of patents invented by Charles A Blum (56 patents): Substituted quinazolin-4-ylamine analogues; Substituted (7-pyridyl-4-phenylamino-quinazolin-2-yl)-methanol analogues; Substituted quinazolin-4-ylamine analogues; Biaryl piperazinyl-pyridine analogues; Spiro[isobenzofuran-1,4′-piperidin]-3-ones and 3H-spiroisobenzofuran-1,4′-piperidines
Microscopic processes leading to ultrafast laser-induced melting of silicon are investigated by large-scale ab initio molecular dynamics simulations. Before becoming a liquid, the atoms are shown to be fractionally diffusive, which is a property that has so far been observed in crowded fluids consisting of large molecules. Here, it is found to occur in an elemental semiconductor. ...
The public activities coordination tool (PACT) provides an overview of the substance-specific activities that authorities are working on under REACH and the CLP Regulation. These activities are being carried out in line with ECHAs Integrated Regulatory Strategy.. PACT provides up-to-date information on the activities planned, ongoing or completed by ECHA and/or MSCAs for a given substance in the following areas:. ...
TY - JOUR. T1 - Influence of the Nature of Boron-Doped Diamond Anodes on the Dehydrogenative Phenol-Phenol Cross-Coupling. AU - Gleede, Barbara. AU - Yamamoto, Takashi. AU - Nakahara, Kenshin. AU - Botz, Alexander. AU - Graßl, Tobias. AU - Neuber, Rieke. AU - Matthée, Thorsten. AU - Einaga, Yasuaki. AU - Schuhmann, Wolfgang. AU - Waldvogel, Siegfried R.. PY - 2019/5/15. Y1 - 2019/5/15. N2 - Boron-doped diamond (BDD) represents a powerful and innovative electrode material. In particular, in combination with fluorinated solvents such as 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), the system exhibits the largest known electrochemical window of approximately 5 V in protic media. Furthermore, the anodic treatment allows the direct formation of oxyl radicals, which are known to exhibit specific reactivity. The electrochemical dehydrogenative phenol-phenol cross-coupling is a versatile and useful transformation to non-symmetric biphenols. This electro-organic conversion can be divided into two regimes: ...
0183]As such a curing catalyst, a known catalyst may suitably be used as a component to accelerate the reaction of reactive silicon groups. Specifically, it may, for example, be an organic tin carboxylate such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, (n-C4H9)2Sn(OCOCH═CHCOOCH3)2, (n-C4H9)2Sn(OCOCH═CHCOO(n-C4H9))2, (n-C8H17)2Sn(OCOCH═CHCOOCH3)2, (n-C8H17)2Sn(OCOCH═CHCOO(n-C4H9))2 or (n-C8H17)2Sn(OCOCH═CHCOO(iso-C8H17))2; a sulfur-containing organic tin compound such as (n-C4H9)2Sn(SCH2COO), (n-C8H17)2Sn(SCH2COO), (n-C8H17)2Sn(SCH2CH2COO), (n-C8H17)2Sn(SCH2COOCH2CH2OCOCH2S), (n-C4H9)2Sn(SCH2COO(iso-C8H17))2, (n-C8H17)2Sn(SCH2COO(iso-C8H17))2, (n-C8H17)2Sn(SCH2COO(n-C8H17))2 or (n-C4H9)2SnS; an organic tin oxide such as (n-C4H9)2SnO or (n-C8H17)2SnO; a reaction product of an ester compound selected from the group consisting of ethyl silicate, dimethyl maleate, diethyl maleate, dioctyl maleate, dimethyl phthalate, diethyl phthalate and dioctyl phthalate, with ...
3-5 DNA helicase involved in error-free bypass of DNA lesions; binds to flap DNA in an error-free bypass pathway and stimulates the activity of Rad27p and Dna2p; also involved in interstrand cross-link repair mutations confer a mutator phenotype; similarity to FANCM, a human Fanconi anemia complementation group protein that along with the MHF complex is involved in stabilizing and remodeling blocked replication forks; member of the SF2 DExD/H superfamily of helicases ...