The thermal degradation pathway studies of a phosphazene derivative on cotton fabric
Technology Transfer Automated Retrieval System (TEKTRAN)
Phosphazene derivatives have been recognized as promising flame retardants for numerous polymeric systems. However, limited studies are available for phosphazene derivatives on cotton fabric. In this study, a phosphazene derivative 1,1,3,3-dihydroxybiphenyl-5,5-diaminoethanephosphazene (dBEP) was ...
Polymer electrolytes based on polymers derived from phosphazenes
V. Chandrasekhar; V. Krishnan; A. Athimoolam; S. Nagendran
Recent developments in the area of phosphazene based polymer electrolytes are summarized. The types of pol y- mers utilized, their synthesis and the ion transport studies carried out on the derived polymer electrolytes are high- lighted. THE phenomenon of ionic conductivity is commonly asso- ciated with liquids. However, as early as in 1834 Faraday demonstrated that PbF2 is highly conducting.
Technology Transfer Automated Retrieval System (TEKTRAN)
Conventional pad-dry-cure (non-scCO2) and supercritical carbon dioxide (scCO2) application methods were investigated to study the effectiveness of a phosphazene derivative as a flame retardant on cotton fabric. 1,1',4,5-tetrahydrotrispiro[1,3,2-diazaphosphole-2,2'-[1,3,5,2,4,6]triazatriphosphinine-4...
Harrup, Mason K; Rollins, Harry W
2013-11-26
An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.
NASA Technical Reports Server (NTRS)
Paciorek, K. L.; Harris, D. H.; Ito, T. I.; Kratzer, R. H.
1980-01-01
The synthesis of a specific phosphazene diamine was optimized, other phosphorus-containing diamines were prepared, and their effect upon certain characteristics of epoxy resins, prepared via reaction with MY 720, in particular, char yield at elevated temperatures was evaluated. The synthesis of the phosphazene diamine resulting from the interaction of methylenedianline with 4,4'-bis(diphenylphosphino)biphenyl was simplified into a one step process giving 77 percent yield of the pure product. Using this procedure, a related diamine containing bis(diphenylphosphino)methane was obtained in a 70 percent yield. Preparation of another class of phosphorus containing amines based upon p-aminophenyldiphenyl-phosphine was unsuccessful; the inability to produce p-aminophenylithlum was responsible for this failure. Seven epoxy resins employing Araldite MY 720, diaminodiphenylsulfone, and two of the phosphorus containing diamines were prepared, characterized, and their char yield capacity at elevated temperatures assessed. Based on these investigations, the resins containing phosphorus appear to exhibit significantly better char formation characteristics than materials hardened using conventional amines, without impairing the other properties measured.
Novel fire-resistant polyphosphazenes and phosphazene-containing polymers
NASA Astrophysics Data System (ADS)
Taylor, Jonathan Paul
A functionalized polyphosphazene, poly[bis(carboxylatophenoxy)phosphazene], was blended with a structural polyurethane via reactive mixing of the polymer with diisocyanate and diol prepolymers. The thermal stabilities of the resultant foams were analyzed by thermogravimetric analysis (TGA). Both qualitative and quantitative flame tests indicated an increase in flame resistance at loadings of 20 wt% and above. Methods for the incorporation of phosphate and phosphonate units into the side groups of phosphazenes are described and evaluated. Halogenated organophosphates were used as the phosphorylating agents and were allowed to react with hydroxyl- or lithio-functionalized phosphazenes. Well defined phosphorylated cyclic trimers were synthesized from the hydroxyl-functionalized precursors, and these were examined as flame retardant additives to polystyrene. The thermal stabilities of the high polymers made by this route were analyzed by TGA. Ring-opening metathesis polymerization (ROMP) of phosphazene-functionalized norbornenes was demonstrated with the use of the Grubbs catalyst. This allowed the incorporation of alkoxy-, fluoroalkoxy-, and aryloxy-derived cyclic phosphazenes as side groups linked to the organic polymer backbone. The polymers were obtained in moderate yields with the properties being dependent on the side groups present and on the molecular weight. In addition, cyclooctenes and norbornenes with cyclic phosphazene side units bearing trifluoroethoxy or phenoxy groups were polymerized via ROMP using a ruthenium based initiator. The same monomers were also copolymerized with 90--99 mole percent of cyclooctene, norbornene, dicyclopentadiene, or exo,exo-5,6-bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]hept-2-ene. The presence of as little as 2 mol% of the cyclic phosphazene in the copolymers dramatically reduced the combustibility. Poly(diphenyl-p-styrylphosphine) and copolymers of diphenyl- p-styrylphosphine with either styrene or methyl methacrylate were functionalized via the Staudinger reaction with phosphazene cyclic trimers bearing an azide side group. The phosphazene rings bore trifluoroethoxy or phenoxy groups as the cosubstituents. All the polymers were characterized by multi-nuclear NMR, GPC, and DSC. The mechanisms of flame retardance were studied with TGA and OI methods. The chemical structures of the polymer backbone and of the phosphazene side groups affected the thermal stability and fire resistance of the final materials.
NASA Astrophysics Data System (ADS)
Hakan, Dal; Serap, Safran; Yasemin, Süzen; Tuncer, Hökelek; K?l?ç, Zeynel
2005-10-01
The condensation reactions of { N-[(2-hydroxyphenylmethyl)amino]-methylpyridines (5-8) with trimer, N 3P 3Cl 6, have been afforded partially substituted novel spiro-cyclic phosphazene derivatives ( 9- 12) ( Scheme 1). Compounds ( 9- 12) have been characterized by elemental analyses, FTIR, 1H-, 13C-, 31P-NMR, HETCOR, and MS. The structure of the spiro-cyclic phosphazene ( 9) has been examined crystallographically. It crystallizes in the P2 1/n space group with a=10.7906(10) Å, b=8.5625(17) Å, c=21.187(5) Å, ?=91.298(12)°, V=1957.1(6) Å 3, Z=4 and Dx=1.660 g cm -3. The structure consists of a non-planar phosphazene ring with a bulky methylpyridinyl and a benzo-fused spiro-cyclic side group. The six-membered spiro-cyclic ring has a twist-boat conformation.
Allen, Charles A. (Idaho Falls, ID); Grey, Alan E. (Idaho Falls, ID); McCaffrey, Robert R. (Milford, MA); Simpson, Brenda M. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID)
1994-01-01
A composite is produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite.
Carboranylmethylene-substituted phosphazenes and polymers thereof
NASA Technical Reports Server (NTRS)
Allcock, H. R.; Scopelianos, A. G. (inventors)
1984-01-01
Carboranylmethylene-substituted cyclophosphazenes are described which can be thermally polymerized into carboranylmethylene-substituted phosphazene polymers. The polymers are useful as thermally stable coatings. Also, due to the characteristics of these polymers in acting as a ligand for transition metals, metalocarboranylmethylene phosphazene polymers are described which can act as immobilized catalyst systems, and are electrically conductive and superconductive.
Allen, C.A.; Grey, A.E.; McCaffrey, R.R.; Simpson, B.M.; Stone, M.L.
1990-12-31
The object of the invention is to provide a composite material comprised of phosphazene polymer. A feature of phosphazene-containing composites is their superior stiffness, thermal stability, and hardness which is lacking in more typical composite constituents. An advantage of using phosphazene composites is a wider range of applications, including uses in harsh environments. Another object of the present invention provides a method for producing phosphazene-containing composite materials through a pultrusion process. In brief, these and other objects are achieved by a composite produced by first coating a reinforcing material with an inorganic phosphazene compound and then polymerizing the phosphazene compound so as to confer superior thermal, physical and chemical resistance qualities to the composite. 2 figs., 6 tabs.
Hybrid phosphazene anodes for energy storage applications
Eric J. Dufek; Mark L. Stone; Kevin L. Gering; Frederick F. Stewart; David Jamison; Aaron D. Wilson; Lucia M. Petkovic; Mason K. Harrup; Harry W. Rollins
2014-12-01
The use of hybrid cyclic phosphazene polymer/graphite anodes, where the phosphazene serves as distributed loci for Li deposition, has been investigated. Capacity within the hybrid system was found to occur reversibly in distinct regions. At the most positive voltages, above 0.06 V vs Li/Li+, the capacity was associated mostly with Li+ intercalation into graphite. In the most negative region, deposition of Li within the polymer was the predominate mechanism. A transitional region is inferred by the data whereby bulk aggregation or clustering of Li atoms occurs in proximity to the phosphazene sites that then serve as a template for more widespread population of Li within the anode at higher voltages, akin to a nucleation process. In full cells with a mixed oxide cathode, controlling the extent of Li deposition by limiting the charging voltage to 4.45 V enabled repeated cycling with no loss in capacity. Capacities as high as 183 mAh g-1 have been achieved for systems containing as little as 10% graphite while retaining coulombic efficiencies of 98% over 50 cycles. This level of cycling equates to the deposition of 7.4 Li per cyclic phosphazene.
Thermal degradation chemistry of poly[bis(phenoxy)phosphazene]
Maynard, Shawn Joseph
1989-01-01
-average molecular weight of poly[bis(4-isopropylphenoxy)phosphazene] (PBIPP) between 100-300 C and calculated the effective energy of activation (30. 5 + 2. 0 kcal) and entropy of activation (-11 cal/deg) for the degradation process, It was shown that P6IPP..., Moore, and Cook monitored the thermal degradation of PBPP with GPC, solution viscosity, and mass spectrometry. Traces of chloro- benzene, phenol, and triphenylphosphate along with trimer, (4), tetramer, (5), and pentamer, (6), shown below, were...
Unsaturated Phosphazenes as Co-Solvents for Lithium-Ion Battery Electrolytes
Mason K Harrup; Harry W. Rollins; David K. Jamison; Eric J Dufek; Kevin L Gering; Thomas A Luther
2014-07-01
This paper covers the synthesis and use of a related family of cyclic phosphazene solvents containing terminal unsaturations. A brief synopsis on the synthesis and purification of these compounds is given. Data will be presented that covers physical and chemical properties of the phosphazenes as well as the properties when blended at various level with representative organic carbonate baseline solvents. Cycling data will be presented using commercially available electrode couples (LRMR/C) as well as studies focusing on cell performance at early lifetime as well as after repeated cycles. Conclusions regarding the effect of the unsaturated phosphazene compounds and their interaction with various alkyl carbonates, and their effect on cell performance will be presented.
Bolink, Henk J; Santamaria, Sonsoles Garcia; Sudhakar, Sundarraj; Zhen, Changgua; Sellinger, Alan
2008-02-01
A novel solution processable phosphorescent dendrimer based on cyclic phosphazene (CP) cores has been prepared and used as emissive layers in simple OLED architectures, providing efficiencies of 24.0 cd A(-1) and 16.7 lm W(-1). PMID:18209808
Water Transport Polymers -- Structure/Property Relationships of a Series of Phosphazene Polymers
Christopher J. Orme; Eric S. Peterson; William F. Bauer; Frederick F. Stewart; Mason K. Harrup; Thomas A. Luther; John R. Klaehn; John E. Wey
2010-01-01
A study was undertaken to explore the water passing properties of a series of phosphazene polymers versus attached pendant group structure. Pendant groups containing different numbers ethyleneoxy groups were synthetically attached to the backbone of phosphazene polymers. Phosphazene polymers facilitate these types of studies because during their synthesis the polymer backbone is formed first and then the desired pendant groups are attached through nucleophilic substitution. For these studies, four polymer series were synthesized and tested for their water passing properties. The polymers contained different amounts of ethyleneoxy units. Two polymer families were synthesized and compared in this work. The critical difference in these two series is that one contained pendant groups with aromatic rings, in addition to the oligioethyleneoxy moieties, while the other does not. Polymers with phenyl group-containing pendant groups exhibited poor water permeability if they possessed fewer than six ethyleneoxy units. Polymers with more than six ethyleneoxy units inserted between the phenyl ring (tail) and the polymeric backbone, exhibited reasonable water permeability. Two additional series of mixed pendant group polymers were synthesized and the water passing properties of the phosphazenes varied in proportion to the hydrophilic to hydrophobic balance induced by each individual pendant group. A final study, polymers with shorter pendant groups, is shown to fully demonstrate the effect of pendant group on water permeability. These studies suggest that the polyphosphazenes may be tailored for specific water passing applications.
A Study of Novel Hexavalent Phosphazene Salts as Draw Solutes in Forward Osmosis
Mark L. Stone; Aaron D. Wilson; Mason K. Harrup; Frederick F. Stewart
2013-03-01
Two novel multi-valent salts based on phosphazene chemistry have been synthesized and characterized as forward osmosis (FO) draw solutes. Commercially obtained hexachlorocyclotriphosphazene was reacted with the sodium salt of 4-ethylhydroxybenzoate to yield hexa(4-ethylcarboxylatophenoxy)phosphazene. Hydrolysis, followed by and neutralization with NaOH or LiOH, of the resulting acidic moieties yielded water soluble sodium and lithium phosphazene salts, respectively. Degrees of dissociation were determined through osmometry over the range of 0.05-0.5 m, giving degrees of 3.08-4.95 per mole, suggesting a high osmotic potential. The Li salt was found to be more ionized in solution than the sodium salt, and this was reflected in FO experiments where the Li salt gave higher initial fluxes (~ 7 L/m2h) as compared to the sodium salt (~6 L/m2h) at identical 0.07 m draw solution concentrations at 30 °C. Longer term experiments revealed no detectable degradation of the salts; however some hydrolysis of the cellulose acetate membrane was observed, presumably due to the pH of the phosphazene salt draw solution (pH = ~8).
Eric S. Peterson; Thomas A. Luther; Mason K. Harrup; John R. Klaehn; Mark L. Stone; Christopher J. Orme; Frederick F. Stewart
2007-06-01
The wide range of applications for the phosphazene compounds has stimulated a major research effort involving several industrial, academic, and national laboratories over the past 40 years. One of Professor Allen’s research areas was to establish fundamental synthetic methods for the commercial preparation of phosphazene polymers, investigate their properties, and develop useful products. In this paper we review some of the materials science aspects of Professor Allen’s research including recent advances on the preparation and polymerization of Cl3PNP(O)Cl2. This work, in particular, has led to a route for the “one-pot” synthesis of stable linear poly(organophosphazenes) as demonstrated through the formation of poly[bis-(2-methoxyethoxyethoxy)phosphazene] (MEEP) and a phosphazene heteropolymer (HPP) containing a balance of hydrophilic and hydrophobic components that allow for control and molecular affinities.
Phosphazene Based Additives for Improvement of Safety and Battery Lifetimes in Lithium-Ion Batteries
Mason K Harrup; Kevin L Gering; Harry W Rollins; Sergiy V Sazhin; Michael T Benson; David K Jamison; Christopher J Michelbacher
2011-10-01
There need to be significant improvements made in lithium-ion battery technology, principally in the areas of safety and useful lifetimes to truly enable widespread adoption of large format batteries for the electrification of the light transportation fleet. In order to effect the transition to lithium ion technology in a timely fashion, one promising next step is through improvements to the electrolyte in the form of novel additives that simultaneously improve safety and useful lifetimes without impairing performance characteristics over wide temperature and cycle duty ranges. Recent efforts in our laboratory have been focused on the development of such additives with all the requisite properties enumerated above. We present the results of the study of novel phosphazene based electrolytes additives.
Chen, Yu-Min; Liao, Yi-Lin; Lin, Jiang-Jen
2010-03-01
Amine substitution of hexachlorocyclophosphazene (HCP) with poly(oxypropylene)diamines (POP) afforded HCP-POP adducts which were subsequently intercalated into a layered silicate clay. The relative thermal stabilities of the epoxies cured with the phosphazene-amines and the intercalated clays were studied. The organoclays, with the confined HCP-POP from 400 and 2000 g/mol M(w) amines, are nongelled products when using 1/6 M ratio of HCP/POP starting materials in tetrahydrofuran solvent. The intercalation of HCP-POP polyamine salts into sodium montmorillonite afforded the HCP-POP-embedded organoclays with an expanded interlayer silicate spacing (2.4-5.1 nm) from the original 1.2 nm spacing (X-ray diffraction). The effect of silicate clays was evaluated by blending the HCP-POP/clay hybrids into a two-component epoxy system (diglycidyl ether of 4,4'-isopropylidenediphenol (BPA) and a diamine) and fully cured to form solid materials. The distribution of the exfoliated silicate platelets in the matrix was analyzed by transmission electronic microscopy (TEM). Thermal gravimetric analysis (TGA) indicated an enhanced thermal stability for the HCP/clay epoxy nanocomposites, with a delayed weight-loss pattern (temperature of weight loss at 10% (T(10 wt.%)) from 360 to 385 degrees C and temperature of weight loss at 85% (T(85 wt.%)) from 598 to 696 degrees C), compared to the pristine epoxies. By comparing these epoxies with different amounts of phosphazene and/or silicates, the TGA revealed a synergistic effect for the presence of both phosphorous and silicate components. Furthermore, the epoxies had improved physical properties such as hardness (from 3H to 5H) and surface adhesion (observed by scanning electron microscope (SEM) on fracture surface). PMID:20003984
Harry W. Rollins; Mason K. Harrup; Eric J. Dufek; David K. Jamison; Sergiy V. Sazhin; Kevin L. Gering; Dayna L. Daubaras
2014-10-01
The safety of lithium-ion batteries is coming under increased scrutiny as they are being adopted for large format applications especially in the vehicle transportation industry and for grid-scale energy storage. The primary short-comings of lithium-ion batteries are the flammability of the liquid electrolyte and sensitivity to high voltage and elevated temperatures. We have synthesized a series of non-flammable fluorinated phosphazene liquids and blended them with conventional carbonate solvents. While the use of these phosphazenes as standalone electrolytes is highly desirable, they simply do not satisfy all of the many requirements that must be met such as high LiPF6 solubility and low viscosity, thus we have used them as additives and co-solvents in blends with typical carbonates. The physical and electrochemical properties of the electrolyte blends were characterized, and then the blends were used to build 2032-type coin cells which were evaluated at constant current cycling rates from C/10 to C/1. We have evaluated the performance of the electrolytes by determining the conductivity, viscosity, flash point, vapor pressure, thermal stability, electrochemical window, cell cycling data, and the ability to form solid electrolyte interphase (SEI) films. This paper presents our results on a series of chemically similar fluorinated cyclic phosphazene trimers, the FM series, which has exhibited numerous beneficial effects on battery performance, lifetimes, and safety aspects.
Wang, Shu-Gen; Jiang, Xin; Chen, Peng-Cheng; Yu, An-Guo; Huang, Xiao-Jun
2012-01-01
A core/sheath nanofiber membrane with poly[bis(p-methylphenoxy)]phosphazene (PMPPh) as the sheath and easily spinnable polyacrylonitrile (PAN) as the core was prepared via a coaxial electrospinning process. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofiber membrane. It was found that the concentration of the PAN spinning solution and the ratio of the core/sheath solution flow rates played a decisive role in the coaxial electrospinning process. In addition, the stabilized core/sheath PMPPh nanofiber membrane was investigated as a support for enzyme immobilization because of its excellent biocompatibility, high surface/volume ratio, and large porosity. Lipase from Candida rugosa was immobilized on the nanofiber membrane by adsorption. The properties of the immobilized lipase on the polyphosphazene nanofiber membrane were studied and compared with those of a PAN nanofiber membrane. The results showed that the adsorption capacity (20.4 ± 2.7 mg/g) and activity retention (63.7%) of the immobilized lipase on the polyphosphazene nanofiber membrane were higher than those on the PAN membrane. PMID:23203055
In vivo tumor transfection mediated by polyplexes based on biodegradable poly(DMAEA)-phosphazene.
de Wolf, Holger K; Luten, Jordy; Snel, Cor J; Oussoren, Christien; Hennink, Wim E; Storm, Gert
2005-12-01
In recent years, increasing interest is being paid to the design of transfectants based on non-toxic and biodegradable polymers for gene therapy purposes. We recently reported on a novel, biodegradable polymer, poly(2-dimethylamino ethylamino)phosphazene (p(DMAEA)-ppz) for use in non-viral gene delivery. In this study, the biodistribution and in vivo transfection efficiency of polyplexes composed of plasmid DNA and p(DMAEA)-ppz were investigated after intravenous administration in tumor bearing mice. Data were compared with those of polyplexes based on the non-biodegradable polyethylenimine (PEI 22kDa). Both polyplex systems were rapidly cleared from the circulation (<7% ID, at 60 min after administration) and showed considerable disposition in the liver and the lung, all in line with earlier work on cationic polyplex systems. The lung disposition is attributed to aggregates formed by interaction of the polyplexes with blood constituents. Redistribution of the polyplexes from the lung was observed for both polyplex formulations. Importantly, both polyplex systems showed a substantial tumor accumulation of 5% and 8% ID/g for p(DMAEA)-ppz and PEI22 polyplexes, respectively, at 240 min after administration. The tumor disposition of the p(DMAEA)-ppz and PEI22 polyplexes was associated with considerable expression levels of the reporter gene. In contrast to PEI22 polyplexes, p(DMAEA)-ppz polyplexes did not display substantial gene expression in the lung or other organs (organ gene expression<1/100 of tumor gene expression). The observed preferential tumor gene expression mediated by the p(DMAEA)-ppz polyplexes enables the application of this polymer to deliver therapeutic genes to tumors. PMID:16039747
An e.s.c.a. study of atomic oxygen interactions with phosphazene-coated polyimide films
NASA Technical Reports Server (NTRS)
Fewell, Larry L.; Finney, Lorie
1991-01-01
Metallic as well as most nonmetallic materials experience oxidation and mass loss via surface erosion in low earth orbit as shown in previous Space Shuttle flights. This study is an evaluation of select polyphosphazene polymers and their resistance to atomic oxygen attack. Electron spectroscopy for chemical analysis examinations of the surfaces of polyphosphazene coatings were monitored for microstructural changes induced during exposures to atomic oxygen. Sample exposures in oxygen plasmas and O(3P) beam were compared as to their effect on surface compositional changes in the polyphosphazene coating. High resolution line scans revealed rearrangements in the polymer backbone and scissioning reactions involving fluorocarbon units of long chain fluoroalkoxy pendant groups. Atom percents and peak areas of all species provided a detailed profile of the microstructural changes induced in phosphazene polymers as a result of exposures to atomic oxygen.
Orme, Christopher Joseph; Klaehn, John Ray; Harrup, Mason Kurt; Lash, Robert Paul; Stewart, Frederick Forrest
2005-05-01
Two linear phosphazene polymers were synthesized with differing amounts of hydrophilic 2-(2-methoxyethoxy)ethanol (MEE) and hydrophobic 4-methoxyphenol (MEOP) substituted on the backbone. These high polymers were cast into membranes and their permeability to water, methanol, ethanol, and 2-propanol was evaluated as a function of temperature. An additional polymer with a low content of MEE was studied for water permeation and was characterized by trace flux. At higher levels of MEE on the backbone, fluxes of all solvents increased. Solubility also was found to increase with increasing MEE content for all solvents except water. Unexpectedly, water was found to be less soluble in the higher MEE polymer, although higher membrane fluxes were observed. Diffusion coefficients showed the following trend: methanol 2-propanol > ethanol water. Finally, the affinity of solvents and polymers was discussed in terms of Hansen solubility parameters.
Shim, Doo-Hee; Ko, Hyun-Jeong; Volker, Gerdts; Potter, Andrew A; Mutwiri, George; Babiuk, Lorne A; Kweon, Mi-Na
2010-03-01
Polyphosphazene polyelectrolyte, a potent new mucosal adjuvant candidate, was tested for its ability to elicit protective immunity against several respiratory diseases. Groups of mice were intranasally (i.n.) vaccinated with poly[di(sodium carboxylatophenoxy)phosphazene] (PCPP) together with several vaccine antigens such as pertussis toxoid, pneumococcal surface protein A, and formalin-inactivated PR8 influenza virus. Results showed predominant levels of antigen-specific IgG and IgA antibodies in serum and bronchial alveolar lavage fluids after vaccination with PCPP plus antigen when compared to antigen alone. In addition, there were significantly higher levels of the secretory form of IgA antibody in the mucosal secretions (i.e., nasal wash, saliva, vaginal wash, and fecal extracts). Moreover, i.n. vaccination with PCPP resulted in brisk numbers of IgG and IgA antibody-forming cells in the nasal passage, lung, and sub-mandibular glands of vaccinated mice. Of note, PCPP administration resulted in mixed Th1 and Th2 type responses (i.e., high levels of IgG2a and IgG1 as well as IFN-gamma and IL-4). Most interestingly, i.n. challenge with vaccine antigens together with PCPP elicited strong protective efficacy against respiratory infection with Bordetella pertussis, Streptococcus pneumoniae, and influenza virus. Taken together, these results suggest that PCPP may be a promising candidate for mucosal adjuvant to elicit protective immunity against respiratory infectious diseases. PMID:20060944
Chen, Chen; Qian, Yue-Cheng; Sun, Chuan-Bin; Huang, Xiao-Jun
2015-07-29
The amphiphilic random copolymer poly(?-d-glucose-co-1-octyl)phosphazene (PGOP) can undergo continuous morphological transitions in DMF-water mixed solvents. In this study, the ratio of glucose moieties to octyl moieties was controlled via a two-step thiol-ene reaction. As a result, polyphosphazenes with glycosyl functionalization degrees of 58.1% (PGOP-1), 74.1% (PGOP-2) and 87.0% (PGOP-3) were obtained. These amphiphilic polyphosphazenes self-assemble in both water and water-DMF mixtures. Several self-assembled morphologies including spheres, rods and vesicles were formed though careful control of the water content (WC) in the DMF solvent as well as of the hydrophilicity or hydrophobicity of the copolymers. We also found that an increase in the hydrophobic proportion led to faster morphological transitions at a constant WC. The thermodynamics of micellization were also studied by Isothermal Titration Calorimetry (ITC), and the strong hydrophobic interactions in PGOP-1 were demonstrated by their highly exothermic nature. These self-assemblies have potential applications in biosensing, lectin adsorption and drug loading with controlled release. PMID:26160257
Kevin L. Gering; Mason K. Harrup; Eric J. Dufek; Sergiy V. Sazhin; Harry W. Rollins; David K. Jamison; Fred F. Stewart; John Burba
2013-09-01
Electrolytes play a central role in performance and aging in most electrochemical systems. As automotive and grid applications place a higher reliance on electrochemical stored energy, it becomes more urgent to have electrolyte components that enable optimal battery performance while promoting battery safety and longevity. Safety remains a foremost concern for widespread utilization of Li-ion technology in electric-drive vehicles, especially as the focus turns to higher voltage systems (5V). This work capitalizes on the long established INL expertise regarding phosphazene chemistry, aimed at battery-viable compounds for electrolytes and electrodes that are highly tolerant to abusive conditions. This report showcases our 2013 work for the DOE applied battery research (ABR) program, wherein testing results are summarized for INL electrolytes and alternative anode materials.
Deng, Meng; Nair, Lakshmi S.; Nukavarapu, Syam P.; Kumbar, Sangamesh G.; Jiang, Tao; Krogman, Nicholas R.; Singh, Anurima; Allcock, Harry R.; Laurencin, Cato T.
2007-01-01
Previously we demonstrated the ability of ethyl glycinato substituted polyphosphazenes to neutralize the acidic degradation products and control the degradation rate of poly(lactic acid-glycolic acid) by blending. In this study, blends of high strength poly[(50% ethyl alanato) (50% p-phenyl phenoxy) phosphazene] (PNEA50PhPh50) and 85:15 poly(lactic acid-glycolic acid) (PLAGA) were prepared using a mutual solvent approach. Three different solvents, methylene chloride (MC), chloroform (CF) and tetrahydrofuran (THF) were studied to investigate solvent effects on blend miscibility. Three different blends were then fabricated at various weight ratios namely 25:75 (BLEND25), 50:50 (BLEND50), and 75:25 (BLEND75) using THF as the mutual solvent. The miscibility of the blends was evaluated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Among these, BLEND25 was miscible while BLEND50 and BLEND75 were partially miscible. Furthermore, BLEND25 formed apatite layers on its surface as evidenced in a biomimetic study performed. These novel blends showed cell adhesion and proliferation comparable to PLAGA. However, the PNEA50PhPh50 component in the blends was able to increase the phenotypic expression and mineralized matrix synthesis of the primary rat osteoblasts (PRO) in vitro. Blends of high strength poly[(50% ethyl alanato) (50% p-phenyl phenoxy) phosphazene] (PNEA50PhPh50) and 85:15 poly(lactic acid-glycolic acid) (PLAGA) are promising biomaterials for a variety of musculoskeletal applications. PMID:17942150
Deng, Meng; Nair, Lakshmi S; Nukavarapu, Syam P; Kumbar, Sangamesh G; Jiang, Tao; Krogman, Nicholas R; Singh, Anurima; Allcock, Harry R; Laurencin, Cato T
2008-01-01
Previously we demonstrated the ability of ethyl glycinato substituted polyphosphazenes to neutralize the acidic degradation products and control the degradation rate of poly(lactic acid-glycolic acid) (PLAGA) by blending. In this study, blends of high strength poly[(50% ethyl alanato) (50% p-phenyl phenoxy) phosphazene] (PNEA(50)PhPh(50)) and 85:15 PLAGA were prepared using a mutual solvent approach. Three different solvents, methylene chloride (MC), chloroform (CF) and tetrahydrofuran (THF) were studied to investigate solvent effects on blend miscibility. Three different blends were then fabricated at various weight ratios namely 25:75 (BLEND25), 50:50 (BLEND50), and 75:25 (BLEND75) using THF as the mutual solvent. The miscibility of the blends was evaluated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Among these, BLEND25 was miscible while BLEND50 and BLEND75 were partially miscible. Furthermore, BLEND25 formed apatite layers on its surface as evidenced in a biomimetic study performed. These novel blends showed cell adhesion and proliferation comparable to PLAGA. However, the PNEA(50)PhPh(50) component in the blends was able to increase the phenotypic expression and mineralized matrix synthesis of the primary rat osteoblasts (PRO) in vitro. Blends of high strength PNEA(50)PhPh(50) and 85:15 PLAGA are promising biomaterials for a variety of musculoskeletal applications. PMID:17942150
Noller, Johannes
2012-07-01
We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field ?, but also of its derivatives via higher order co-ordinate invariants (such as ?{sub ?}??{sup ?}?,??,...). Specifically we consider the first such non-trivial conformal factor A(?,?{sub ?}??{sup ?}?). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for ? ? ?+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type.
Fractional Derivative as Fractional Power of Derivative
Vasily E. Tarasov
2007-11-16
Definitions of fractional derivatives as fractional powers of derivative operators are suggested. The Taylor series and Fourier series are used to define fractional power of self-adjoint derivative operator. The Fourier integrals and Weyl quantization procedure are applied to derive the definition of fractional derivative operator. Fractional generalization of concept of stability is considered.
SPATIAL DERIVATIVES AND PERTURBATION DERIVATIVES OF AMPLITUDE
Cerveny, Vlastislav
SPATIAL DERIVATIVES AND PERTURBATION DERIVATIVES OF AMPLITUDE IN ISOTROPIC AND ANISOTROPIC MEDIA L. The spatial and perturbation derivatives of the logarithm of amplitude can be calculated by numerical quadratures along the rays. The spatial derivatives of amplitude may be useful in calculating the higher
Derived Types What Are Derived Types?
Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C++, Python, etc. are very similar · One is structures -- i.e., composite objects Arbitrary types, statically indexed by name · The other is user-defined types Often called semantic extension This is where
Derived Types What Are Derived Types?
Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C++, Python, etc. are very similar · One is structures -- i.e., composite objects Arbitrary types, statically indexed by name · The other is user-defined types Often called semantic extension This is where object
charles cao
The construction of a financial product from other products; New securities can be ... Exchange-traded derivatives; Over-the-counter traded derivatives: even more! ... XYZ: bid = $49.75, offer = $50, commission = $15; Buy: (100 x $50) + $15 = ...
ERIC Educational Resources Information Center
Dixon, R. M. W.
2008-01-01
Phonological and semantic principles which underlie the derivation of verbs from nouns and adjectives in English are examined. There is intricate phonological conditioning for suffix "-ize" and for suffix "-(i)fy"; a third major process is zero derivation. These derivational processes cover more than a score of semantic relations (some with…
T. Matolcsi; P. Van
2006-10-23
A four dimensional treatment of nonrelativistic space-time gives a natural frame to deal with objective time derivatives. In this framework some well known objective time derivatives of continuum mechanics appear as Lie-derivatives. Their coordinatized forms depends on the tensorial properties of the relevant physical quantities. We calculate the particular forms of objective time derivatives for scalars, vectors, covectors and different second order tensors from the point of view of a rotating observer. The relation of substantial, material and objective time derivatives is treated.
Endohedral Metallofullerene Derivatives
NASA Technical Reports Server (NTRS)
Dorn, Harry C. (Inventor); Iezzi, Erick B. (Inventor); Duchamp, James (Inventor)
2008-01-01
Trimetallic nitride endohedral metallofullerene derivatives and their preparation are described. The trimetallic nitride endohedral metallofullerene derivatives have the general formula A(sub 3-n)X(sub n)@C(sub m)(R) where n ranges from 0 to 3, A and X may be trivalent metals and may be either rare earth metal or group IIIB metals, m is between about 60 and about 200, and R is preferably an organic group. Derivatives where the R group forms cyclized derivatives with the fullerene cage are also described.
Mesomorphic Derivatives Of Ferrocene
Jacques Malthete; Jean Billard
1976-01-01
The first series of ferrocene derivatives exhibiting mesomorphic properties (substituted N-(p-benzoyloxybenzylidene) anilines la and 1b) has been synthesized for application in Mössbauer spectroscopy.
Deriving Common Model Characteristics
NSDL National Science Digital Library
Jennifer Momsen
In this activity, students confront several different models - from the DNA helix Watson and Crick constructed in their laboratory to a map of McDonalds density in the US - and work in small groups to derive their commonalities.
Teaching Cournot without Derivatives.
ERIC Educational Resources Information Center
Dufwenberg, Martin
2001-01-01
Presents a simple technique for teaching the Cournot model to first-year microeconomic students. Involves demonstrating, without the use of derivatives, that out of all rectangles with a common perimeter, the square has the greatest area. (RLH)
Oxygenated Derivatives of Hydrocarbons
Technology Transfer Automated Retrieval System (TEKTRAN)
For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...
Rüther, Henrique
2007-01-01
The amounts outstanding of credit derivatives have grown exponentially over the past years, and these financial intruments that allow market participants to trade credit risk have become very popular in Europe and in the ...
NASA Astrophysics Data System (ADS)
Hodge Markgraf, J.; Choi, Bo Yoon
1998-02-01
In connection with qualitative analysis schemes for organic laboratory experiments, a safe and convenient procedure is described for the small-scale preparation of an aldehyde derivative. Aliphatic and aromatic aldehydes are converted to 3-substituted-1,5-dihydro-2,4-benzodithiepines in high yield when treated with 1,2-benzenedimethanethiol in dichloromethane at room temperature with catalysis by ferric chloride on silica gel. The products are readily recrystallized from ethanol. Melting points for 27 derivatives are tabulated.
Semisynthetic Derivatives of Epothilones
NASA Astrophysics Data System (ADS)
Altmann, Karl-Heinz
Semisynthetic derivatives of natural products traditionally occupy a prominent space in natural-product-based drug discovery (1, 2). As many biologically active natural products exhibit a high degree of structural complexity (3), the chemical derivatization of material isolated from natural sources often represents the only feasible means (or at least the only economically viable approach) to explore structure-activity-relationships (SAR) and to produce analogs with more favorable pharmacokinetic and pharmacological properties than the natural product lead. Examples of clinically important drugs that are semisynthetic derivatives of natural products exist in virtually all disease areas (1, 2); in the treatment of cancer this includes compounds such as etoposide or teniposide (derived from podophyllotoxin) (4-6), irinotecan and topotecan (derived from camptothecin) (7-9), or docetaxel (derived from 10-deacetylbaccatin III) (10, 11). Even for taxol (11), which is a natural product (12), the sustained supply of sufficient quantities of material for widespread clinical use could only be secured through the development of a semisynthetic production process from another natural product, namely, 10-deacetylbaccatin III (13). In light of these facts, it is not surprising that semisynthesis approaches have also featured prominently in the elucidation of the SAR for epothilones and in the discovery of a number of clinical development candidates.
Biotechnology and derived products
Technology Transfer Automated Retrieval System (TEKTRAN)
Microorganisms able to infect and kill insect pests, metabolites from plants and microorganisms, and transgenic crops are biotechnologically derived products that are being promoted for use to control insect pests in lieu of chemical insecticides. Products based on these technologies effectively co...
de Lange, Titia
Telomeric 30 Overhangs Derive from Resection by Exo1 and Apollo and Fill-In by POT1b-Associated CST and main- tenance of mammalian telomeres, but its synthesis must be regulated to avoid excessive resection of the 50 end, which could cause telomere shortening. How this balance is achieved in mammals has not been
Collett Jr., Jeffrey L.
Structures and Derived Types #12;Introduction It's often useful to group related variables or components into a single entity or structure, and these may even be comprised of objects of different types_code area_co number #12;Start with a really simple example. First we need a type definition statement: type
Organometallic Derivatives of Diazoalkanes
NASA Astrophysics Data System (ADS)
Kruglaya, O. A.; Vyazankin, N. S.
1980-04-01
The methods of synthesis and properties of organometallic derivatives of diazo-compounds are examined, attention being concentrated on the influence of the metal or the organometallic fragment on the structure and reactivity of the diazo-compounds. Studies on the use of metal-containing diazoalkanes as precursors of carbynes and ?-metallated carbenes as well as studies on the reactivity of the latter are discussed. The bibliography includes 165 references.
Semisynthetic Derivatives of Epothilones
Karl-Heinz Altmann
2009-01-01
Semisynthetic derivatives of natural products traditionally occupy a prominent space in natural-product-based drug discovery\\u000a (1, 2). As many biologically active natural products exhibit a high degree of structural complexity (3), the chemical derivatization of material isolated from natural sources often represents the only feasible means (or at least\\u000a the only economically viable approach) to explore structure-activity-relationships (SAR) and to produce
Derived enriched uranium market
Rutkowski, E.
1996-12-01
The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market.
NSDL National Science Digital Library
Karen Salvage
This exercise begins with a demonstration of fluid flow through porous sediment using a constant head permeameter, with the students conducting the experiment and collecting the data. The demo is followed by a Think-Pair-Share exercise in which the question is posed to the class: "What could we change in order to increase flow through the system?" The class then works through their brainstormed list of ideas, discussing each and evaluating whether it is correct or a misconception. The students derive Darcy's Law qualitatively, based upon the results of the Think-Pair-Share exercise and discussions.
NASA Technical Reports Server (NTRS)
1983-01-01
COPAMS, Commonwealth of Pennsylvania Air Monitoring System, derives from technology involved in building unmanned spacecraft. The Nimbus spacecraft carried experimental sensors to measure temperature, pressure, ozone, and water vapor, and instruments for studying solar radiation and telemetry. The process which relayed these findings to Earth formed the basis for COPAMS. The COPAMS system consists of data acquisition units which measure and record pollution level, and sense wind speed and direction, etc. The findings are relayed to a central station where the information is computerized. The system is automatic and supplemented by PAQSS, PA Air Quality Surveillance System.
Sulphenamides and their derivatives
NASA Astrophysics Data System (ADS)
Petrov, K. A.; Rudnev, G. V.; Sorokin, V. D.
1990-09-01
Information has been presented systematically on the synthesis of sulphenamides and related compounds by reaction of sulphenyl chlorides and sulphur chlorides with amines and carboxylic acid amides; by reaction of chloramines with mercaptans; by transamination of N-acylsulphenamides; and by reaction of disulphides with amines. The following chemical reactions of sulphenamides have been examined: reaction with hydrogen halides; with acids and derivatives possessing coordinatively unsaturated atoms; and the addition of sulphenamides to the double bond of carbon disulphide, isocyanates, isothiocyanates and olefins. Data are given on the physical state of sulphenamides and on the region characteristic of the S-N bond vibrations. The bibliography includes 190 references.
Acquiring Knowledge of Derived Nominals and Derived Adjectives in Context
ERIC Educational Resources Information Center
Marinellie, Sally A.; Kneile, Lynn A.
2012-01-01
Purpose: This research investigated children's ability to acquire semantic and syntactic knowledge of derived nominals and derived adjectives in the context of short passages. The study also investigated the relation of morphological awareness and the ability to acquire knowledge of derived words in context. Method: A total of 106 children in…
Incorporating topological derivatives into shape derivatives based level set methods
NASA Astrophysics Data System (ADS)
He, Lin; Kao, Chiu-Yen; Osher, Stanley
2007-07-01
Shape derivatives and topological derivatives have been incorporated into level set methods to investigate shape optimization problems. The shape derivative measures the sensitivity of boundary perturbations while the topological derivative measures the sensitivity of creating a small hole in the interior domain. The combination of these two derivatives yields an efficient algorithm which has more flexibility in shape changing and may escape from a local optimal. Examples on finding the optimal shapes for maximal band gaps in photonic crystal and acoustic drum problems are demonstrated.
DRS: Derivational Reasoning System
NASA Technical Reports Server (NTRS)
Bose, Bhaskar
1995-01-01
The high reliability requirements for airborne systems requires fault-tolerant architectures to address failures in the presence of physical faults, and the elimination of design flaws during the specification and validation phase of the design cycle. Although much progress has been made in developing methods to address physical faults, design flaws remain a serious problem. Formal methods provides a mathematical basis for removing design flaws from digital systems. DRS (Derivational Reasoning System) is a formal design tool based on advanced research in mathematical modeling and formal synthesis. The system implements a basic design algebra for synthesizing digital circuit descriptions from high level functional specifications. DRS incorporates an executable specification language, a set of correctness preserving transformations, verification interface, and a logic synthesis interface, making it a powerful tool for realizing hardware from abstract specifications. DRS integrates recent advances in transformational reasoning, automated theorem proving and high-level CAD synthesis systems in order to provide enhanced reliability in designs with reduced time and cost.
Synthesis of some pyridone derivatives.
Dawood, N T; Abdel-Gawad, S M; Soliman, F M
2001-01-01
Chlorination of 6-aryl-3-cyano-2-pyridone-4-carboxylic acid (1) afforded the corresponding acid chloride (2) and the 2-chloro derivative (3). Esterification of (2) gave the corresponding esters (4a; b). Hydrazinolysis of (4a) afforded the respective pyridazinone derivative (5). Treatment of 6-aryl-2-chloro-3-cyano-4-pyridine carboxylic acid (3) with acetyl hydrazine, gave the triazinopyridine derivative (6), while treatment of 3 with sodium azide in DMF afforded the tetrazinopyridine derivative (7). Treatment of the N-acetyl derivative (1b) with thiosemicarbazide and/or hydroxylamine hydrochloride, yielded the correspoding semicarbazone and oxine derivatives (8) and (10), respectively. The reaction of 6-aryl-3-cyano-1,2-dihydro-2-thioxo-4-pyridinecarboxylic acid (1c) with ethylchloro acetate and/or thiourea yielded the mercapto ester derivative (11) and the corresponding pyrido [2,3-d] pyrimidine thione derivative (12). Condensation reaction of (1d) with anthranilic acid, afforded the quinazolone derivative (11). The reactivity of 11 towards hydrazine hydrate was investigated. The structural assignment of the new derivatives were based on IR, 1H NMR and mass data. Some of the new compounds were screened, in vitro, for antimicrobial activity and the results were encouraging. PMID:11486604
Deriving bedform phase diagrams
NSDL National Science Digital Library
Tom Hickson
Students prepare for this activity by working with a unidirectional flume with a sand bed. We adjust water depth, flow velocity, and channel slope to achieve a range of bed states, in an effort for them to understand the controls on bedforms. This portion of the activity could be done in lecture or via another exercise that makes use of digital video of actual experiments. The activity itself is a jigsaw: students form groups of three, each group responsible for plotting depth vs. velocity plots of bedform state for a single sand grain size range (0.10-0.14 mm, 0.5-0.64 mm, and 1.3-1.8 mm). These data are provided to them as Excel files and the data were directly 'stolen' from the original depth vs. velocity plots in Middleton and Southard (1984), Mechanics of Sediment Movement, SEPM Short Course Number 3. Datathief software (available free on the web) was used to steal the data. The data are arranged in columns: depth, velocity, and bedform type. Students must plot each of the different bedform types with a different symbol, then they have to define field boundaries. It is critical that they have never seen the original plots in their textbook. The goal is for them to derive them on their own, not to regurgitate what is in their textbook or elsewhere. After they complete their plots for each grain size range, the groups re-arrange themselves into groups of three with one representative from each of the grain size groups. They then must try to evaluate the effects of changing grain size on bedform state. Finally, after completing the exercise, the bedform analysis is linked to the cross stratification that is produced under conditions of high sediment fallout rates and the given bed state. The activity gives students practice working with realistic datasets, exposure to the role of physical modeling in sedimentary geology, and a chance to plot and interpret real data. Furthermore, it really solidifies the link between cross stratification and its dynamic interpretation from the rock record.
Finite investigations of transfinite derivations
G. E. Mints
1978-01-01
?-derivations of arithmetic formulas are analyzed. A primitive recursive normalization operator E is constructed in the first part. It cut-eliminates not only recursively described derivations (i.e., well-founded proof-figures) but also arbitrary (not necessarily well-founded) proof-figures constructed from an axiom by derivation rules. This permits us to apply E in the theory of models, Its application in the theory of proofs
Derivation of the effective potential
R. Fukuda; E. Kyriakopoulos
1975-01-01
A simple derivation of the effective potential for single and composite operators is given. Green functions under general constraints are considered and compact expressions for derivatives of the effective potential are given. On leave of absence from Nuclear Research Center ``Democritos'', Aghia Paraskevi Attikis, Greece.
What is a fractional derivative?
NASA Astrophysics Data System (ADS)
Ortigueira, Manuel D.; Tenreiro Machado, J. A.
2015-07-01
This paper discusses the concepts underlying the formulation of operators capable of being interpreted as fractional derivatives or fractional integrals. Two criteria for required by a fractional operator are formulated. The Grünwald-Letnikov, Riemann-Liouville and Caputo fractional derivatives and the Riesz potential are accessed in the light of the proposed criteria. A Leibniz rule is also obtained for the Riesz potential.
Quinazoline derivatives: synthesis and bioactivities
2013-01-01
Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reaction, Ultrasound-promoted reaction and Phase-transfer catalysis reaction. The biological activities of the synthesized quinazoline derivatives also are discussed. PMID:23731671
Complex higher order derivative theories
Margalli, Carlos A.; Vergara, J. David [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico 04510 DF (Mexico)
2012-08-24
In this work is considered a complex scalar field theory with higher order derivative terms and interactions. A procedure is developed to quantize consistently this system avoiding the presence of negative norm states. In order to achieve this goal the original real scalar high order field theory is extended to a complex space attaching a complex total derivative to the theory. Next, by imposing reality conditions the complex theory is mapped to a pair of interacting real scalar field theories without the presence of higher derivative terms.
Rational design of pyrrolobenzodiazepine derivatives
Kaliszczak, Maciej
2009-11-25
Pyrrolobenzodiazepine (PBD) derivatives interact with the minor-groove of DNA to form mono-adducts (monomers) or cross-links (dimers). They show remarkable activity in vitro and in vivo in a wide range of tumour types ...
DALI: Derivative Approximation for LIkelihoods
NASA Astrophysics Data System (ADS)
Sellentin, Elena
2015-07-01
DALI (Derivative Approximation for LIkelihoods) is a fast approximation of non-Gaussian likelihoods. It extends the Fisher Matrix in a straightforward way and allows for a wider range of posterior shapes. The code is written in C/C++.
Wang, Shu-Gen; Jiang, Xin; Chen, Peng-Cheng; Yu, An-Guo; Huang, Xiao-Jun
2012-01-01
A core/sheath nanofiber membrane with poly[bis(p-methylphenoxy)]phospha-zene (PMPPh) as the sheath and easily spinnable polyacrylonitrile (PAN) as the core was prepared via a coaxial electrospinning process. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofiber membrane. It was found that the concentration of the PAN spinning solution and the ratio of the core/sheath solution flow rates played a decisive role in the coaxial electrospinning process. In addition, the stabilized core/sheath PMPPh nanofiber membrane was investigated as a support for enzyme immobilization because of its excellent biocompatibility, high surface/volume ratio, and large porosity. Lipase from Candida rugosa was immobilized on the nanofiber membrane by adsorption. The properties of the immobilized lipase on the polyphosphazene nanofiber membrane were studied and compared with those of a PAN nanofiber membrane. The results showed that the adsorption capacity (20.4 ± 2.7 mg/g) and activity retention (63.7%) of the immobilized lipase on the polyphosphazene nanofiber membrane were higher than those on the PAN membrane. PMID:23203055
Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal Point Methods Yves Lucet & Warren Hare July 24, 2013 1 / 26 #12;Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Outline 1
Drugs derived from phage display
Nixon, Andrew E; Sexton, Daniel J; Ladner, Robert C
2014-01-01
Phage display, one of today’s fundamental drug discovery technologies, allows identification of a broad range of biological drugs, including peptides, antibodies and other proteins, with the ability to tailor critical characteristics such as potency, specificity and cross-species binding. Further, unlike in vivo technologies, generating phage display-derived antibodies is not restricted by immunological tolerance. Although more than 20 phage display-derived antibody and peptides are currently in late-stage clinical trials or approved, there is little literature addressing the specific challenges and successes in the clinical development of phage-derived drugs. This review uses case studies, from candidate identification through clinical development, to illustrate the utility of phage display as a drug discovery tool, and offers a perspective for future developments of phage display technology. PMID:24262785
Sigman, Michael E.; Dindal, Amy B.
2003-11-11
Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.
Polymyxins and their novel derivatives.
Vaara, Martti
2010-10-01
The emerging very multiresistant Gram-negative bacteria cause remarkable therapeutic challenges. There are no novel classes of agents in clinical development for the treatment of Gram-negative infections. Polymyxins (polymyxin B and colistin) were abandoned in the seventies but are now back in the therapy as the last resort. Their nephrotoxicity may complicate the therapy or even necessitate its discontinuation. Less toxic polymyxin derivatives would be highly welcome. Novel derivatives lack in strategic positions two of the five cationic charges of polymyxins, differ from polymyxins in their renal handling and affinity to kidney brush-border membrane, and are in preclinical studies. Less characterized other recent derivatives, also reviewed here, have increased the collective knowledge on the structure-function relationships in polymyxins. Acquired resistance to polymyxins has been encountered. However, the resistance mechanism compromises the function of the bacterial outer membrane as a permeability barrier to other noxious agents. PMID:20869908
Fractional derivatives in Dengue epidemics
Pooseh, Shakoor; Torres, Delfim F M
2011-01-01
We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.
Magnetic cellulose-derivative structures
Walsh, M.A.; Morris, R.S.
1986-09-16
Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorption agents can be incorporated during the manufacture of the structure. 3 figs.
Canonical derivation of effective potentials
Martin Bojowald; Suddhasattwa Brahma
2014-11-13
A canonical formulation of effective equations describes quantum corrections by the back-reaction of moments on the dynamics of expectation values of a state. As a first step toward an extension to quantum-field theory, these methods are applied here to the derivation of effective potentials around a homogeneous vacuum expectation value of scalar fields. A comparison with the standard Coleman-Weinberg potential shows that the new methods correctly include all relevant quantum corrections. At the same time, the effective potential is shown to be correct also for non-Fock and mixed states. Several explicit results are derived in models of interacting scalars and fermions.
Informational derivation of Quantum Theory
G. Chiribella; G. M. D'Ariano; P. Perinotti
2011-07-15
Quantum theory can be derived from purely informational principles. Five elementary axioms-causality, perfect distinguishability, ideal compression, local distinguishability, and pure conditioning-define a broad class of theories of information-processing that can be regarded as a standard. One postulate-purification-singles out quantum theory within this class. The main structures of quantum theory, such as the representation of mixed states as convex combinations of perfectly distinguishable pure states, are derived directly from the principles without using the Hilbert space framework.
Magnetic cellulose-derivative structures
Walsh, Myles A. (Falmouth, MA); Morris, Robert S. (Fairhaven, MA)
1986-09-16
Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorbtion agents can be incorporated during the manufacture of the structure.
Quaternion Derivatives: The GHR Calculus
Dongpo Xu; Cyrus Jahanchahi; Clive C. Took; Danilo P. Mandic
2014-09-25
Quaternion derivatives in the mathematical literature are typically defined only for analytic (regular) functions. However, in engineering problems, functions of interest are often real-valued and thus not analytic, such as the standard cost function. The HR calculus is a convenient way to calculate formal derivatives of both analytic and non-analytic functions of quaternion variables, however, both the HR and other functional calculus in quaternion analysis have encountered an essential technical obstacle, that is, the traditional product rule is invalid due to the non- commutativity of the quaternion algebra. To address this issue, a generalized form of the HR derivative is proposed based on a general orthogonal system. The so introduced generalization, called the generalized HR (GHR) calculus, encompasses not just the left- and right-hand versions of quaternion derivative, but also enables solutions to some long standing problems, such as the novel product rule, the chain rule, the mean-valued theorem and Taylor's theorem. At the core of the proposed approach is the quaternion rotation, which can naturally be applied to other functional calculi in non-commutative settings. Examples on using the GHR calculus in adaptive signal processing support the analysis.
Derivation Trees and Regular Languages
Goddard, Wayne
pieces, one can write S A | B; and if the concatenation of two pieces, one can write S CD. If overall language is the star of a piece, say generated by E, then one can write S ES | . Goddard 6b: 10 #12 of is the sequence of steps that gets to . A leftmost derivation is where at each stage one replaces the leftmost
Informational derivation of quantum theory
Chiribella, Giulio; D'Ariano, Giacomo Mauro; Perinotti, Paolo
2011-07-15
We derive quantum theory from purely informational principles. Five elementary axioms - causality, perfect distinguishability, ideal compression, local distinguishability, and pure conditioning - define a broad class of theories of information processing that can be regarded as standard. One postulate - purification - singles out quantum theory within this class.
Flüssigkristalline aromatische Cholesterin-Derivate
NASA Astrophysics Data System (ADS)
Vill, V.; Thiem, J.; Rollin, P.
1992-03-01
Liquid Crystalline Aromatic Cholesterol Derivates A series of aromatic cholesteryl ethers, esters, phenylcarbonates and benzylcarbonates were prepared and their liquid crystalline properties studied. The occurence of ferroelectric phases as well as properties of cholesteric and blue phases alternate with the number of linking atomes between steroid and atomatic system
Alchemical derivatives of reaction energetics
NASA Astrophysics Data System (ADS)
Sheppard, Daniel; Henkelman, Graeme; von Lilienfeld, O. Anatole
2010-08-01
Based on molecular grand canonical ensemble density functional theory, we present a theoretical description of how reaction barriers and enthalpies change as atoms in the system are subjected to alchemical transformations, from one element into another. The change in the energy barrier for the umbrella inversion of ammonia is calculated along an alchemical path in which the molecule is transformed into water, and the change in the enthalpy of protonation for methane is calculated as the molecule is transformed into a neon atom via ammonia, water, and hydrogen fluoride. Alchemical derivatives are calculated analytically from the electrostatic potential in the unperturbed system, and compared to numerical derivatives calculated with finite difference interpolation of the pseudopotentials for the atoms being transformed. Good agreement is found between the analytical and numerical derivatives. Alchemical derivatives are also shown to be predictive for integer changes in atomic numbers for oxygen binding to a 79 atom palladium nanoparticle, illustrating their potential use in gradient-based optimization algorithms for the rational design of catalysts.
Quinuclidine Derivatives as Potential Antiparasitics
Simon B. Cammerer; Carmen Jimenez; Simon Jones; Ludovic Gros; Silvia Orenes Lorente; Carlos Rodrigues; Juliany C. F. Rodrigues; Aura Caldera; Luis Miguel Ruiz Perez; Wanderley da Souza; Marcel Kaiser; Reto Brun; Julio A. Urbina; Dolores Gonzalez Pacanowska; Ian H. Gilbert
2007-01-01
There is an urgent need for the development of new drugs for the treatment of tropical parasitic diseases such as Chagas' disease and leishmaniasis. One potential drug target in the organisms that cause these diseases is sterol biosynthesis. This paper describes the design and synthesis of quinuclidine derivatives as potential inhibitors of a key enzyme in sterol biosynthesis, squalene synthase
40 CFR 721.1820 - Bisphenol derivative.
Code of Federal Regulations, 2013 CFR
2013-07-01
...2013-07-01 2013-07-01 false Bisphenol derivative. 721.1820 Section 721...Chemical Substances § 721.1820 Bisphenol derivative. (a) Chemical substance...chemical substance identified generically as bisphenol derivative (PMN No....
40 CFR 721.1820 - Bisphenol derivative.
Code of Federal Regulations, 2014 CFR
2014-07-01
...2014-07-01 2014-07-01 false Bisphenol derivative. 721.1820 Section 721...Chemical Substances § 721.1820 Bisphenol derivative. (a) Chemical substance...chemical substance identified generically as bisphenol derivative (PMN No....
Edge Detection Discrete approx. of a derivative
Vaswani, Namrata
Edge Detection #12;· Discrete approx. of a derivative · Threshold the derivative image · Second derivative, zero crossing detect Weak edges (gradual variation) detected better, less chance of multiple variance) · Compass: directional edge detection #12;· Spatial convolution · Edge localization · Canny edge
12 CFR 403.4 - Derivative classification.
Code of Federal Regulations, 2011 CFR
2011-01-01
...2011-01-01 false Derivative classification. 403.4 Section 403.4 Banks...EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING...INFORMATION § 403.4 Derivative classification. (a) Use of derivative...
HEAT EQUATION DERIVATIVE FORMULAS FOR VECTOR BUNDLES
Driver, Bruce
HEAT EQUATION DERIVATIVE FORMULAS FOR VECTOR BUNDLES results improve the formula in Driver [* *19] for logarithmic derivatives of the heat kernel derivative formu- las for differentials and co-differentials of heat semigroups on forms, * *and more
12 CFR 403.4 - Derivative classification.
Code of Federal Regulations, 2012 CFR
2012-01-01
...2012-01-01 false Derivative classification. 403.4 Section 403.4 Banks...EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING...INFORMATION § 403.4 Derivative classification. (a) Use of derivative...
12 CFR 403.4 - Derivative classification.
Code of Federal Regulations, 2013 CFR
2013-01-01
...2013-01-01 false Derivative classification. 403.4 Section 403.4 Banks...EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING...INFORMATION § 403.4 Derivative classification. (a) Use of derivative...
12 CFR 403.4 - Derivative classification.
Code of Federal Regulations, 2014 CFR
2014-01-01
...2014-01-01 false Derivative classification. 403.4 Section 403.4 Banks...EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING...INFORMATION § 403.4 Derivative classification. (a) Use of derivative...
Derivation of aerodynamic kernel functions
NASA Technical Reports Server (NTRS)
Dowell, E. H.; Ventres, C. S.
1973-01-01
The method of Fourier transforms is used to determine the kernel function which relates the pressure on a lifting surface to the prescribed downwash within the framework of Dowell's (1971) shear flow model. This model is intended to improve upon the potential flow aerodynamic model by allowing for the aerodynamic boundary layer effects neglected in the potential flow model. For simplicity, incompressible, steady flow is considered. The proposed method is illustrated by deriving known results from potential flow theory.
Partial derivative of love numbers
Shuhei Okubo; Masanori Saito
1983-01-01
We present a simple formula for the partial derivatives of Love numbers with respect to density, bulk modulus and rigidity\\u000a without urging the Adams-Williamson condition in the liquid core. Partials of the second degree Love numbers are computed\\u000a for model 1066 A. Love numbers prove to be either completely or virtually independent of the elastic profile within the whole\\u000a core.
Position Estimation Using Image Derivative
NASA Technical Reports Server (NTRS)
Mortari, Daniele; deDilectis, Francesco; Zanetti, Renato
2015-01-01
This paper describes an image processing algorithm to process Moon and/or Earth images. The theory presented is based on the fact that Moon hard edge points are characterized by the highest values of the image derivative. Outliers are eliminated by two sequential filters. Moon center and radius are then estimated by nonlinear least-squares using circular sigmoid functions. The proposed image processing has been applied and validated using real and synthetic Moon images.
Deriving confinement via RG decimations
E. T. Tomboulis
2007-10-10
We present the general framework and building blocks of a recent derivation of the fact that the SU(2) LGT is in a confining phase for all values of the coupling $0 < \\beta < \\infty$, for space-time dimension $d \\leq 4$. The method employs approximate but explicitly computable RG decimations that are shown to constrain the exact partition function and order parameters from above and below, and flow from the weak to the strong coupling regime without encountering a fixed point.
Weather Forecasting for Weather Derivatives
Sean D. Campbell; Francis X. Diebold
2003-01-01
We take a simple time-series approach to modeling and forecasting daily average temperature in U.S. cities, and we inquire systematically as to whether it may prove useful from the vantage point of participants in the weather derivatives market. The answer is, perhaps surprisingly, yes. Time-series modeling reveals both strong conditional mean dynamics and conditional variance dynamics in daily average temperature,
Weather Forecasting for Weather Derivatives
Sean D. Campbell; Francis X. Diebold
2004-01-01
We take a simple time-series approach to modeling and forecasting daily average temperature in U.S. cities, and we inquire systematically as to whether it may prove useful from the vantage point of participants in the weather derivatives market. The answer is, perhaps surprisingly, yes. Time-series modeling reveals conditional mean dynamics, and crucially, strong conditional variance dynamics, in daily average temperature,
Weather Forecasting for Weather Derivatives
Sean D. Campbell; Francis X. Diebold
2005-01-01
Abstract: We take a nonstructural time-series approach to modeling and forecasting daily average temperature in ten U.S. cities, and we inquire systematically as to whether it may prove useful from the vantage point of participants in the weather derivatives market. The answer is, perhaps surprisingly, yes. Time series modeling reveals both strong conditional mean dynamics,and conditional variance dynamics in daily
The Fermi derivative in the hypersurfaces
NASA Astrophysics Data System (ADS)
Karaku?, Fatma; Yayli, Yusuf
2015-10-01
In this study, Fermi derivative and according to the derivative Fermi parallelism and non-rotating frame concepts are given on any hypersurface in En+1. Initially, Fermi derivative and non-rotating concepts are analyzed on any hypersurface in E4. As an example, S3 is taken instead of the hypersurface in E4. Fermi derivative and non-rotating concepts are examined for S3. Then a correlation is found between Fermi derivative and Levi-Civita derivative of any vector field in E4. And then the concepts of Fermi derivative are generalized for n > 4 in En+1.
Derivation of orifice equations reevaluated
Hall, K.R.; Eubank, P.T.; Holste, J.C.
1983-07-01
Orifice meters are in widespread use as economical flow measurement devices. The gas industry uses them routinely for custody transfer of billions of dollars worth of gas and liquefied products. Yet, some confusion exists in application and interpretation of the orifice equations to calculate flowrates. Current (and future) product values provide a driving force to remove this confusion. The purpose in this article is to present the results of a derivation which retains a maximum of rigor and clearly labels each assumption. The most significant conclusions relate to use of the supercompressibility factor, the gas gravity, and the expression for mass flowrate.
Antimycobacterial activity of nitrogen heterocycles derivatives: bipyridine derivatives. Part III.
Danac, Ramona; Mangalagiu, Ionel I
2014-03-01
Three classes of fused bipyridine heterocycles were designed, synthesized and evaluated for their antimycobacterial activities. The method for preparation of fused bipyridine derivatives is straight and efficient. The primary antimycobacterial screening reveals that mono-indolizine mono-salts are displaying potency superior to the second-line antitubercular drugs Cycloserine and Pyrimethamine and, equal as the first line anti-TB Ethambutol. The data from Cycle-2 screening assay (MIC, MBC, LORA, intracellular (macrophage) drug screening, and MTT cell proliferation) confirm the promising anti-TB results from Cycle-1 for mono-indolizine mono-salts. These data indicate that mono-indolizine mono-salt 6d is a potent compound against both replicating and non-replicating Mycobacterium tuberculosis, is active against both extracellular and intracellular organisms, has a bacteriostatic mechanism of action and has basically no toxicity. We see no influence concerning the anti-TB activity of the fused-pyridine substituents. PMID:24268596
Fourth order spatial derivative gravity
Bemfica, F. S.; Gomes, M. [Instituto de Fisica, Universidade de Sao Paulo Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil)
2011-10-15
In this work, we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Horava-Lifshitz gravity. The propagator is evaluated and, as a result, one extra pole is obtained, corresponding to a spin-2 nonrelativistic massless particle, an extra term which jeopardizes renormalizability, besides the unexpected general relativity unmodified propagator. Then unitarity is proved at the tree level, where the general relativity pole has been shown to have no dynamics, remaining only the 2 degrees of freedom of the new pole. Next, the nonrelativistic effective potential is determined from a scattering process of two identical massive gravitationally interacting bosons. In this limit, Newton's potential is obtained, together with a Darwin-like term that comes from the extra nonpole term in the propagator. Regarding renormalizability, this extra term may be harmful by power counting, but it can be eliminated by adjusting the free parameters of the model. This adjustment is in accord with the detailed balance condition suggested in the literature and shows that the way in which extra spatial derivative terms are added is of fundamental importance.
Fourth order spatial derivative gravity
NASA Astrophysics Data System (ADS)
Bemfica, F. S.; Gomes, M.
2011-10-01
In this work, we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Ho?ava-Lifshitz gravity. The propagator is evaluated and, as a result, one extra pole is obtained, corresponding to a spin-2 nonrelativistic massless particle, an extra term which jeopardizes renormalizability, besides the unexpected general relativity unmodified propagator. Then unitarity is proved at the tree level, where the general relativity pole has been shown to have no dynamics, remaining only the 2 degrees of freedom of the new pole. Next, the nonrelativistic effective potential is determined from a scattering process of two identical massive gravitationally interacting bosons. In this limit, Newton’s potential is obtained, together with a Darwin-like term that comes from the extra nonpole term in the propagator. Regarding renormalizability, this extra term may be harmful by power counting, but it can be eliminated by adjusting the free parameters of the model. This adjustment is in accord with the detailed balance condition suggested in the literature and shows that the way in which extra spatial derivative terms are added is of fundamental importance.
Deriving Laws from Ordering Relations
NASA Technical Reports Server (NTRS)
Knuth, Kevin H.
2004-01-01
The effect of Richard T. Cox's contribution to probability theory was to generalize Boolean implication among logical statements to degrees of implication, which are manipulated using rules derived from consistency with Boolean algebra. These rules are known as the sum rule, the product rule and Bayes Theorem, and the measure resulting from this generalization is probability. In this paper, I will describe how Cox s technique can be further generalized to include other algebras and hence other problems in science and mathematics. The result is a methodology that can be used to generalize an algebra to a calculus by relying on consistency with order theory to derive the laws of the calculus. My goals are to clear up the mysteries as to why the same basic structure found in probability theory appears in other contexts, to better understand the foundations of probability theory, and to extend these ideas to other areas by developing new mathematics and new physics. The relevance of this methodology will be demonstrated using examples from probability theory, number theory, geometry, information theory, and quantum mechanics.
Shuttle derived unmanned launch vehicle
NASA Astrophysics Data System (ADS)
Buell, D. N.; Tewell, J. R.
1985-04-01
An unmanned launch vehicle derived using existing Space Transportation System (STS) components was studied. The vehicle incorporates a standard STS external tank and solid rocket boosters, a new payload module and a recoverable propulsion/avionics module housing the high cost avionics and propulsion systems. The main propulsion system is a cluster of three STS space shuttle main engines compatible with the STS launch pad. The orbital maneuvering system utilizes components and the reaction control system incorporates modified STS primary and vernier thrusters. A solid rocket propulsion system made up of six motors having a two second burn time is incorporated for decelerating the recoverable propulsion/avionics module to a soft landing. The sidemount shuttle derived launch vehicle can carry 147,000 pounds to a 150 nautical mile circular orbit from the Eastern Test Range of 104,000 pounds from the Western Test Range. With Centaur G-prime the payload capability to geosynchronous earth orbit is 24,500 pounds. Performance with an optimized upper stage and a stretched external tank was also investigated.
NASA Astrophysics Data System (ADS)
Boynton, R. J.; Balikhin, M. A.; Billings, S. A.; Sharma, A. S.; Amariutei, O. A.
2011-06-01
The NARMAX OLS-ERR methodology is applied to identify a mathematical model for the dynamics of the Dst index. The NARMAX OLS-ERR algorithm, which is widely used in the field of system identification, is able to identify a mathematical model for a wide class of nonlinear systems using input and output data. Solar wind-magnetosphere coupling functions, derived from analytical or data based methods, are employed as the inputs to such models and the outputs are geomagnetic indices. The newly deduced coupling function, p1/2V4/3BTsin6(?/2), has been implemented as an input to model the Dst dynamics. It was shown that the identified model has a very good forecasting ability, especially with the geomagnetic storms.
Derivation of orifice equations evaluated
Hall, K.R.; Eubank, P.T.; Holste, J.C.
1983-07-11
A derivation of the orifice equations starting with the First Law of Thermodynamics calculates mass flow rates with exactly the same information required for volumetric flow rates. The working equations - empirical correlations based upon data for real fluids - provide results that are essentially correct for fluids similar to the original test gases. However, these equations cannot be extended to new composition, pressure, and temperature ranges because of the oversimplified forms given. Although the uncertainties in the flow rates are small (a few tenths of a percent), they are magnified by the greatly increased market values of the fluids of interests. Analysts recommend revising the working equations for custody transfer of natural gas based upon orifice meters to reflect a more realistic model of the physical situation. More accurate data correlations could then be made and the resulting multiplying factors would represent specific physical phenomena.
Deriving Laws from Ordering Relations
NASA Technical Reports Server (NTRS)
Knuth, Kevin H.
2003-01-01
It took much effort in the early days of non-Euclidean geometry to break away from the mindset that all spaces are flat and that two distinct parallel lines do not cross. Up to that point, all that was known was Euclidean geometry, and it was difficult to imagine anything else. We have suffered a similar handicap brought on by the enormous relevance of Boolean algebra to the problems of our age-logic and set theory. Previously, I demonstrated that the algebra of questions is not Boolean, but rather is described by the free distributive algebra. To get to this stage took much effort, as many obstacles-most self-placed-had to be overcome. As Boolean algebras were all I had ever known, it was almost impossible for me to imagine working with an algebra where elements do not have complements. With this realization, it became very clear that the sum and product rules of probability theory at the most basic level had absolutely nothing to do with the Boolean algebra of logical statements. Instead, a measure of degree of inclusion can be invented for many different partially ordered sets, and the sum and product rules fall out of the associativity and distributivity of the algebra. To reinforce this very important idea, this paper will go over how these constructions are made, while focusing on the underlying assumptions. I will derive the sum and product rules for a distributive lattice in general and demonstrate how this leads to probability theory on the Boolean lattice and is related to the calculus of quantum mechanical amplitudes on the partially ordered set of experimental setups. I will also discuss the rules that can be derived from modular lattices and their relevance to the cross-ratio of projective geometry.
Derivative Sign Patterns in Two Dimensions
ERIC Educational Resources Information Center
Schilling, Kenneth
2013-01-01
Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.
A study on real estate derivatives
Lim, Jong Yoon, S.M. Massachusetts Institute of Technology
2006-01-01
All major asset classes including stocks and bonds have a well developed derivative market. Derivatives enable counterparties to reflect a view on a particular market, without having to trade the underlying asset. This ...
17 CFR 200.506 - Derivative classification.
Code of Federal Regulations, 2012 CFR
2012-04-01
...2012-04-01 false Derivative classification. 200.506 Section 200.506...ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National...Material § 200.506 Derivative classification. Any document that...
17 CFR 200.506 - Derivative classification.
Code of Federal Regulations, 2013 CFR
2013-04-01
...2013-04-01 false Derivative classification. 200.506 Section 200.506...ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National...Material § 200.506 Derivative classification. Any document that...
17 CFR 200.506 - Derivative classification.
Code of Federal Regulations, 2014 CFR
2014-04-01
...2014-04-01 false Derivative classification. 200.506 Section 200.506...ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National...Material § 200.506 Derivative classification. Any document that...
Code of Federal Regulations, 2014 CFR
2014-07-01
...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...
Code of Federal Regulations, 2013 CFR
2013-07-01
...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...
Code of Federal Regulations, 2011 CFR
2011-07-01
...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...
Bioactive Terpenes from Marine-Derived Fungi
Elissawy, Ahmed M.; El-Shazly, Mohamed; Ebada, Sherif S.; Singab, AbdelNasser B.; Proksch, Peter
2015-01-01
Marine-derived fungi continue to be a prolific source of secondary metabolites showing diverse bioactivities. Terpenoids from marine-derived fungi exhibit wide structural diversity including numerous compounds with pronounced biological activities. In this review, we survey the last five years’ reports on terpenoidal metabolites from marine-derived fungi with particular attention on those showing marked biological activities. PMID:25854644
Postgraduate Scholarship Pricing temperature derivatives and modelling
Banaji,. Murad
the volumetric risk of the energy units sold, rather than the price risk of each unit. Weather derivativesPostgraduate Scholarship Pricing temperature derivatives and modelling the market price of risk: Pricing temperature derivatives and modelling the market price of risk. Main Supervisor: A. Alexandridis
Development of the beta-pressure derivative
Hosseinpour-Zoonozi, Nima
2007-04-25
The proposed work provides a new definition of the pressure derivative function [that is the Ã?Â²-derivative function, Ã?Â?p Ã?Â²d(t)], which is defined as the derivative of the logarithm of pressure drop data with respect to the logarithm of time...
DERIVATIVE-FREE OPTIMIZATION Algorithms, software and
Grossmann, Ignacio E.
1 DERIVATIVE-FREE OPTIMIZATION Algorithms, software and applications Nick Sahinidis National Energy) With: global optimality, provided search is "dense" #12;12 DERIVATIVE-FREE OPTIMIZATION SOFTWARE LOCAL@cmu.edu Acknowledgments: Luis Miguel Rios NIH and DOE/NETL #12;2 DERIVATIVE-FREE OPTIMIZATION · Optimization of a function
Technical Report The Derivational Complexity Induced
Middeldorp, Aart
Technical Report The Derivational Complexity Induced by the Dependency Pair Method Georg Moser the derivational complexity induced by the (basic) dependency pair method based on reasonably strong base orders. Suppose the derivational complexity induced by a (direct) termination method is closed under elemen- tary
?-Nitro Derivatives of Iron Corrolates
Nardis, Sara; Stefanelli, Manuela; Mohite, Pruthviraj; Pomarico, Giuseppe; Tortora, Luca; Manowong, Machima; Chen, Ping; Fronczek, Frank R.; McCandless, Gregory T.
2012-01-01
Two different methods for the regioselective nitration of different meso-triarylcorroles leading to the corresponding ?-substituted nitrocorrole iron complexes have been developed. A two-step procedure affords three Fe(III) nitrosyl products - the unsubstituted corrole, the 3-nitrocorrole and the 3,17-dinitrocorrole. In contrast, a one-pot synthetic approach drives the reaction almost exclusively to formation of the iron nitrosyl 3,17-dinitrocorrole. Electron-releasing substituents on the meso-aryl groups of the triarylcorroles induce higher yields and longer reaction times than what is observed for the synthesis of similar triarylcorroles with electron-withdrawing functionalities, and these results can be confidently attributed to the facile formation and stabilization of an intermediate iron corrole ?-cation radical. Electron-withdrawing substituents on the meso-aryl groups of triarylcorrole also seem to labilize the axial nitrosyl group which, in the case of the pentafluorophenylcorrole derivative, results in the direct formation of a disubstituted iron ?-oxo dimer complex. The influence of meso-aryl substituents on the progress and products of the nitration reaction was investigated. In addition, to elucidate the most important factors which influence the redox reactivity of these different iron nitrosyl complexes, selected compounds were examined by cyclic voltammetry and thin-layer UV-visible or FTIR spectroelectrochemistry in CH2Cl2. PMID:22394192
Clinical status of benzoporphyrin derivative
NASA Astrophysics Data System (ADS)
Levy, Julia G.; Chan, Agnes H.; Strong, H. Andrew
1996-01-01
Benzoporphyrin derivative monoacid ring A (BPD) is currently in Phase II clinical trials for the treatment of cutaneous malignancies (basal cell carcinoma and cutaneous metastases) and psoriasis. Results to date suggest that this photosensitizer has potential in both of these areas. Recently, a clinical trial with BPD was initiated for the treatment of age related macular degeneration, a neovascular condition in the eye which leads to blindness. BPD is a lipophilic photosensitizer which is rapidly taken up by activated cells and the vascular endothelium of neovasculature. The PDT effects seen with BPD appear to be a combination of vascular occlusion and direct killing of target cells. Since many diseases involve either activated cells and/or neovasculature, PDT with photosensitizer with characteristics like those of BPD, has applications far wider than oncology. A new area of interest involving photosensitizers is that of immune modulation. A number of photosensitizers have been shown to effect immune modulation in animal models of immune dysfunction including autoimmunity (rheumatoid arthritis, lupus), cutaneous hypersensitivity and allografts. BPD and PHOTOFRINR have both been shown to be effective in ameliorating arthritic symptoms in a number of animal models. The mechanisms by which immune modulation is affected in these studies still remains to be resolved.
NASA Technical Reports Server (NTRS)
1982-01-01
The QuadraScan Longterm Flow Monitoring System is a second generation sewer monitor developed by American Digital Systems, Inc.'s founder Peter Petroff. Petroff, a former spacecraft instrumentation designer at Marshall Space Flight Center, used expertise based on principles acquired in Apollo and other NASA programs. QuadraScan borrows even more heavily from space technology, for example in its data acquisition and memory system derived from NASA satellites. "One-time" measurements are often plagued with substantial errors due to the flow of groundwater absorbed into the system. These system sizing errors stem from a basic informational deficiency: accurate, reliable data on how much water flows through a sewer system over a long period of time is very difficult to obtain. City officials are turning to "permanent," or long-term sewer monitoring systems. QuadraScan offers many advantages to city officials such as the early warning capability to effectively plan for city growth in order to avoid the crippling economic impact of bans on new sewer connections in effect in many cities today.
STS Derived Exploration Launch Operations
NASA Technical Reports Server (NTRS)
Best, Joel; Sorge, L.; Siders, J.; Sias, Dave
2004-01-01
A key aspect of the new space exploration programs will be the approach to optimize launch operations. A STS Derived Launch Vehicle (SDLV) Program can provide a cost effective, low risk, and logical step to launch all of the elements of the exploration program. Many benefits can be gained by utilizing the synergy of a common launch site as an exploration spaceport as well as evolving the resources of the current Space Shuttle Program (SSP) to meet the challenges of the Vision for Space Exploration. In particular, the launch operation resources of the SSP can be transitioned to the exploration program and combined with the operations efficiencies of unmanned EELVs to obtain the best of both worlds, resulting in lean launch operations for crew and cargo missions of the exploration program. The SDLV Program would then not only capture the extensive human space flight launch operations knowledge, but also provide for the safe fly-out of the SSP through continuity of system critical skills, manufacturing infrastructure, and ability to maintain and attract critical skill personnel. Thus, a SDLV Program can smoothly transition resources from the SSP and meet the transportation needs to continue the voyage of discovery of the space exploration program.
Representations of partial derivatives in thermodynamics
NASA Astrophysics Data System (ADS)
Thompson, John R.; Manogue, Corinne A.; Roundy, David J.; Mountcastle, Donald B.
2012-02-01
One of the mathematical objects that students become familiar with in thermodynamics, often for the first time, is the partial derivative of a multivariable function. The symbolic representation of a partial derivative and related quantities present difficulties for students in both mathematical and physical contexts, most notably what it means to keep one or more variables fixed while taking the derivative with respect to a different variable. Material properties are themselves written as partial derivatives of various state functions (e.g., compressibility is a partial derivative of volume with respect to pressure). Research in courses at the University of Maine and Oregon State University yields findings related to the many ways that partial derivatives can be represented and interpreted in thermodynamics. Research has informed curricular development that elicits many of the difficulties using different representations (e.g., geometric) and different contexts (e.g., connecting partial derivatives to specific experiments).
Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives
Moribe, Kunikazu; Limwikrant, Waree; Higashi, Kenjirou; Yamamoto, Keiji
2011-01-01
Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs or carrier components. Ascorbyl n-alkyl fatty acid derivatives have been formulated as antioxidants or anticancer drugs for nanoparticle formulations such as micelles, microemulsions, and liposomes. ASC-P vesicles called aspasomes are submicron-sized particles that can encapsulate hydrophilic drugs. Several transdermal and injectable formulations of ascorbyl n-alkyl fatty acid derivatives were used, including ascorbyl palmitate. PMID:21603195
Ophthalmic use of blood-derived products.
Nugent, Ryan B; Lee, Graham A
2015-01-01
There is a wide spectrum of blood-derived products that have been used in many different medical and surgical specialties with success. Blood-derived products for clinical use can be extracted from autologous or allogeneic specimens of blood, but recombinant products are also commonly used. A number of blood derivatives have been used for a wide range of ocular conditions, from the ocular surface to the retina. With stringent preparation guidelines, the potential risk of transmission of blood-borne diseases is minimized. We review blood-derived products and how they are improving the management of ocular disease. PMID:26077627
ALTERNATIVE DERIVATION OF EM CLOAKS AND CONCENTRATORS
Maryland at College Park, University of
ALTERNATIVE DERIVATION OF EM CLOAKS AND CONCENTRATORS Arthur D. Yaghjian AFRL (Consultant), Hanscom;ALTERNATIVE DERIVATION OF EM CLOAKS AND CONCENTRATORS (r), (r) V r Je inc, Jm inc O and are continuous al. 2007-08 #12;GOOD NEWS · Perfect cloaks and nonscatterers, such as concentrators
A MECHANISTIC DERIVATION OF THE LOGISTIC MODEL
Yang Kuang
The purpose of this note is to mechanistically derive the logistic population growth models from the well tested and received Droop equation. 1. A mechanistic derivation of the logistic equation. Population growth involves and often is determined by the birth and death processes. Most of the existing studies focus on birth process on the combined birth and death processes (the
[Biological activity of the isothiazole derivatives].
Miedzybrodzki, Ryszard
2003-01-01
The isothiazole ring was first synthesized in 1956 by Adams and Slack. It was known earlier in condensed structures such as benzisothiazole (saccharin for example). The first found natural origin isothiazole derivative was brassilexin--a phytoalexin from Brassica juncea. In this review diverse biological activity of isothiazole derivatives and their application has been presented. PMID:15002160
Derive Workshop Matrix Algebra and Linear Algebra.
ERIC Educational Resources Information Center
Townsley Kulich, Lisa; Victor, Barbara
This document presents the course content for a workshop that integrates the use of the computer algebra system Derive with topics in matrix and linear algebra. The first section is a guide to using Derive that provides information on how to write algebraic expressions, make graphs, save files, edit, define functions, differentiate expressions,…
Derivational Morphology and Base Morpheme Frequency
ERIC Educational Resources Information Center
Ford, M. A.; Davis, M. H.; Marslen-Wilson, W. D.
2010-01-01
Morpheme frequency effects for derived words (e.g. an influence of the frequency of the base "dark" on responses to "darkness") have been interpreted as evidence of morphemic representation. However, it has been suggested that most derived words would not show these effects if family size (a type frequency count claimed to reflect semantic…
Some Results From Utilizing Doppler Derivatives
Levanon, Nadav
, and the angle between them, as functions of a radar Doppler shift and its first two derivatives are given. I. Analysis The Doppler shift as a function of time of a static radar return from a moving target (or viceSome Results From Utilizing Doppler Derivatives Abstract Explicit expressions of range, velocity
Deriving the Area of a Circle.
ERIC Educational Resources Information Center
Austin, Joe Dan
1992-01-01
Argues that the derivation of the area of a circle using integral calculus is invalid. Describes the derivation of the area of a circle when the formula is not known by inscribing and circumscribing the circle with regular polygons whose areas converge to the same number. (MDH)
Can material time derivative be objective?
T. Matolcsi; P. Van
2005-10-10
The concept of objectivity in classical field theories is traditionally based on time dependent Euclidean transformations. In this paper we treat objectivity in a four-dimensional setting, calculate Christoffel symbols of the spacetime transformations, and give covariant and material time derivatives. The usual objective time derivatives are investigated.
Integrating weather derivatives for managing risks
Bilski, B.
1999-11-01
As deregulation and customer choice loom on the horizon, many energy utilities and other energy suppliers are scrambling to find new services that add value for consumers. Many are also seeking opportunities for increasing efficiency to ensure that costs remain competitive. Integrating weather derivatives with marketing programs and financial management can produce attractive new services and increase efficiency. Weather derivatives can be used to create innovative consumer services, such as a guaranteed annual energy bill which is unaffected by weather and energy price changes. They can also be used to protect the earnings of energy suppliers from one of their most significant financial risks, unpredictable weather. There are three basic types of weather derivatives available today. Option or insurance based derivatives (options), swaps or hedge based derivatives (swaps) and packages where other services are combined with one or both of the above.
Pharmacokinetics of 4-aminopyridine derivatives in dogs.
Olby, N J; Smith, D T; Humphrey, J; Spinapolice, K; Parke, N; Mehta, P M; Dise, D; Papich, M
2009-10-01
Blockade of potassium channels with 4-aminopryidine (4-AP) restores conduction to demyelinated axons and improves function. Unfortunately, 4-AP causes adverse effects and its clinical effects are unpredictable and limited. Derivatives of 4-AP have been tested in models of spinal cord injury in guinea pigs; three derivatives (methyl-, ethyl- and t-butyl carbamate derivatives) showed promise. This study investigates the safety and pharmacokinetics of these derivatives in dogs. Each derivative was administered orally to dogs starting at doses below effective doses in guinea pigs, and increasing the dose on sequential days. Routine blood work was performed prior to and 24 h after drug administration, blood samples were collected at intervals over 24 h after drug administration, and dogs were monitored for side effects. Derivative plasma levels were determined using high-pressure liquid chromatography. Cerebrospinal fluid (CSF) samples were taken to determine CSF levels. No adverse effects were seen even when using doses higher than those that improved conduction in spinal cord injured guinea pigs. Peak plasma levels occurred at 36.6 (ethyl), 87 (t-butyl) and 175 (methyl) min and plasma level was related to drug dose. Penetration of the central nervous system (CNS) was good, with CSF levels higher than plasma levels for the t-butyl derivative. PMID:19754916
Risk management, derivatives and shariah compliance
NASA Astrophysics Data System (ADS)
Bacha, Obiyathulla Ismath
2013-04-01
Despite the impressive growth of Islamic Banking and Finance (IBF), a number of weaknesses remain. The most important of this is perhaps the lack of shariah compliant risk management tools. While the risk sharing philosophy of Islamic Finance requires the acceptance of risk to justify returns, the shariah also requires adherents to avoid unnecessary risk-maysir. The requirement to avoid maysir is in essence a call for the prudent management of risk. Contemporary risk management revolves around financial engineering, the building blocks of which are financial derivatives. Despite the proven efficacy of derivatives in the management of risk in the conventional space, shariah scholars appear to be suspicious and uneasy with their use in IBF. Some have imposed outright prohibition of their use. This paper re-examines the issue of contemporary derivative instruments and shariah compliance. The shariah compatibility of derivatives is shown in a number of ways. First, by way of qualitative evaluation of whether derivatives can be made to comply with the key prohibitions of the sharia. Second, by way of comparing the payoff profiles of derivatives with risk sharing finance and Bai Salam contracts. Finally, the equivalence between shariah compliant derivatives like the IPRS and Islamic FX Currency Forwards with conventional ones is presented.
The Boltzmann factor: a simplified derivation
NASA Astrophysics Data System (ADS)
Müller, Rainer
2014-09-01
We give a simple derivation of the Boltzmann factor from a microcanonical point of view. The derivation is similar to Boltzmann's own approach but avoids the use of Lagrangian multipliers. In the Boltzmann-Einstein model, we consider an assembly of n+1 boxes. One of the boxes represents the system under consideration, the others act as a thermal reservoir. Energy is distributed over the combined system in discrete portions, not necessarily of quantum character. We derive the probability for the system to have a certain number of energy portions by counting the number of compatible states, thus arriving at the Boltzmann factor.
Complex networks derived from cellular automata
Yoshihiko Kayama
2010-09-23
We propose a method for deriving networks from one-dimensional binary cellular automata. The derived networks are usually directed and have structural properties corresponding to the dynamical behaviors of their cellular automata. Network parameters, particularly the efficiency and the degree distribution, show that the dependence of efficiency on the grid size is characteristic and can be used to classify cellular automata and that derived networks exhibit various degree distributions. In particular, a class IV rule of Wolfram's classification produces a network having a scale-free distribution.
The Theory of Quaternion Matrix Derivatives
NASA Astrophysics Data System (ADS)
Xu, Dongpo; Mandic, Danilo P.
2015-03-01
A systematic theory is introduced for calculating the derivatives of quaternion matrix function with respect to quaternion matrix variables. The proposed methodology is equipped with the matrix product rule and chain rule and it is able to handle both analytic and nonanalytic functions. This corrects a flaw in the existing methods, that is, the incorrect use of the traditional product rule. In the framework introduced, the derivatives of quaternion matrix functions can be calculated directly without the differential of this function. Key results are summarized in tables. Several examples show how the quaternion matrix derivatives can be used as an important tool for solving problems related to signal processing.
The Theory of Quaternion Matrix Derivatives
Dongpo Xu; Danilo P. Mandic
2014-10-01
A systematic theory is introduced for calculating the derivatives of quaternion matrix function with respect to quaternion matrix variables. The proposed methodology is equipped with the matrix product rule and chain rule and it is able to handle both analytic and nonanalytic functions. This corrects a flaw in the existing methods, that is, the incorrect use of the traditional product rule. In the framework introduced, the derivatives of quaternion matrix functions can be calculated directly without the differential of this function. Key results are summarized in tables. Several examples show how the quaternion matrix derivatives can be used as an important tool for solving problems related to signal processing.
Pressure deriving port of internal combustion engine
Mitani, T.
1989-04-25
A structure of a pressure deriving port is described for an internal combustion engine having an intake manifold in which at least one of an exhaust gas recirculating port and a blow-by gas discharge port and an opening of the pressure deriving port are formed. It consists of opening the pressure deriving port positioned on an upstream side of at least one of the exhaust gas recirculating port formed in a stepped-up portion of an inner wall of the intake manifold.
Theory of Financial Risk and Derivative Pricing
NASA Astrophysics Data System (ADS)
Bouchaud, Jean-Philippe; Potters, Marc
2004-02-01
Summarizing market data developments, some inspired by statistical physics, this book explains how to better predict the actual behavior of financial markets with respect to asset allocation, derivative pricing and hedging, and risk control. Risk control and derivative pricing are major concerns to financial institutions. The need for adequate statistical tools to measure and anticipate amplitude of potential moves of financial markets is clearly expressed, in particular for derivative markets. Classical theories, however, are based on assumptions leading to systematic (sometimes dramatic) underestimation of risks. First edition Hb (2000): 0-521-78232-5
[Mechanism of Platinum Derivatives Induced Kidney Injury].
Yan, Feifei; Duan, Jianchun; Wang, Jie
2015-09-20
Platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors, lung cancer, and colorectal cancer. Two major problems exist, however, in the clinic use of platinum derivatives. One is the development of tumor resistance to the drug during therapy, leading to treatment failure. The other is the drug's toxicity such as the cisplatin's nephrotoxicity, which limits the dose that can be administered. This paper describes the mechanism of platinum derivatives induced kidney injury. PMID:26383983
Cellulose Derivatives for Water Repellent Properties
Technology Transfer Automated Retrieval System (TEKTRAN)
Synthesis and structural characterizations of nitro-benzyl cellulose, amino-benzyl cellulose and pentafluoro –benzyl cellulose were carried out. Cellulose derivatives were synthesized by etherification process in lithium chloride/N,N-dimethylacetamide homogeneous solution. Nitrobenzylation was effec...
Phytol-Derived Novel Isoprenoid Immunostimulants
Chowdhury, Roshni Roy; Ghosh, Swapan K.
2012-01-01
This review describes the adjuvanticity of novel diterpenoids (synthetic phytol derivatives) compared to some commercially available adjuvants. The efficacy of the phytol-derived immunostimulants was evaluated in terms of their ability to activate innate immunity, amplify various antigen-specific immune responses, and engender immunological memory with no discernible adverse effects in both competent and immune-deficient mice. The profile that emerges out of these studies reveals that the phytol derivatives are excellent immunostimulants, superior to a number of commercial adjuvants in terms of long-term memory induction and activation of both innate and acquired immunity. Additionally, the phytol-derived compounds have no cumulative inflammatory or toxic effects even in immuno-compromised mice. PMID:22566931
SCM Forcing Data Derived from NWP Analyses
Jakob, Christian
Forcing data, suitable for use with single column models (SCMs) and cloud resolving models (CRMs), have been derived from NWP analyses for the ARM (Atmospheric Radiation Measurement) Tropical Western Pacific (TWP) sites of Manus Island and Nauru.
SCM Forcing Data Derived from NWP Analyses
Jakob, Christian
2008-01-15
Forcing data, suitable for use with single column models (SCMs) and cloud resolving models (CRMs), have been derived from NWP analyses for the ARM (Atmospheric Radiation Measurement) Tropical Western Pacific (TWP) sites of Manus Island and Nauru.
MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS
Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...
Polyimides Derived from Novel Asymmetric Benzophenone Dianhydrides
NASA Technical Reports Server (NTRS)
Chuang, Chun-Hua (Inventor)
2015-01-01
This invention relates to the composition and processes for preparing thermoset polyimides derived from an asymmetric dianhydride, namely 2,3,3',4'-benzophenone dianhydride (a-BTDA) with at least one diamine, and a monofunctional terminal endcaps. The monofunctional terminating groups include 4-phenylethynylphthalic anhydride ester-acid derivatives, phenylethyl trimellitic anhydride (PETA) and its ester derivatives as well as 3-phenylethynylaniline. The process of polyimide composite comprises impregnating monomer reactants of dianhydride or its ester-acid derivatives, diamine and with monofunctional reactive endcaps into glass, carbon, quartz or synthetic fibers and fabrics, and then stack up into laminates and subsequently heated to between 150-375.degree. C. either at atmosphere or under pressure to promote the curing and crosslinking of the reactive endcaps to form a network of thermoset polyimides.
45 CFR 601.5 - Derivative classification.
Code of Federal Regulations, 2010 CFR
2010-10-01
...Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION...DECLASSIFICATION OF NATIONAL SECURITY INFORMATION § 601.5 Derivative...is the determination that information is in substance the same as information currently...
45 CFR 601.5 - Derivative classification.
Code of Federal Regulations, 2011 CFR
2011-10-01
...Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION...DECLASSIFICATION OF NATIONAL SECURITY INFORMATION § 601.5 Derivative...is the determination that information is in substance the same as information currently...
Perspectives on Biologically Active Camptothecin Derivatives.
Liu, Ying-Qian; Li, Wen-Qun; Morris-Natschke, Susan L; Qian, Keduo; Yang, Liu; Zhu, Gao-Xiang; Wu, Xiao-Bing; Chen, An-Liang; Zhang, Shao-Yong; Nan, Xiang; Lee, Kuo-Hsiung
2015-07-01
Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small-molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects. PMID:25808858
A naphthoquinone derivative from Tectona grandis (Linn.).
Gupta, Pradeep K; Singh, Pahup
2004-09-01
A new naphthoquinone derivative has been isolated, along with a number of prenylnaphthoquinone congeners, from the heartwood of Tectona grandis (Linn.). It was characterized as dehydro-alpha-isodunnione (1) by careful analysis of its spectral data. PMID:15224424
RPA Pathwise Derivative Estimation of Ruin Probabilities
VÃ¡zquez-Abad, Felisa J.
RPA Pathwise Derivative Estimation of Ruin Probabilities Felisa J. V'azquezÂAbad \\Lambda Department important information in establishing premiums and evaluating sensitivities to risk. In V'azquezÂAbad
5 CFR 1312.7 - Derivative classification.
Code of Federal Regulations, 2010 CFR
2010-01-01
...2010-01-01 false Derivative classification. 1312.7 Section 1312.7 ...MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION, DOWNGRADING, DECLASSIFICATION...OF NATIONAL SECURITY INFORMATION Classification and Declassification of National...
5 CFR 1312.7 - Derivative classification.
Code of Federal Regulations, 2011 CFR
2011-01-01
...2011-01-01 false Derivative classification. 1312.7 Section 1312.7 ...MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION, DOWNGRADING, DECLASSIFICATION...OF NATIONAL SECURITY INFORMATION Classification and Declassification of National...
17 CFR 200.506 - Derivative classification.
Code of Federal Regulations, 2010 CFR
2010-04-01
...Security Information and Material § 200.506 Derivative classification. Any document that includes paraphrases, restatements, or summaries of, or incorporates in new form, information that is already classified shall be assigned...
Research Article Quinoline Ring Derivatives Protect
Rubel, Edwin
compounds quinoline, isoquinoline, naphthalene, and indole for protective effects. Of these compounds, indole demonstrated a small but significant amount of protection against neomycin, while quinoline activity of this group of compounds was related to known targets of the quinoline derivatives
Entanglement entropy in higher derivative holography
NASA Astrophysics Data System (ADS)
Bhattacharyya, Arpan; Kaviraj, Apratim; Sinha, Aninda
2013-08-01
We consider holographic entanglement entropy in higher derivative gravity theories. Recently Lewkowycz and Maldacena [1] have provided a method to derive the equations for the entangling surface from first principles. We use this method to compute the entangling surface in four derivative gravity. Certain interesting differences compared to the two derivative case are pointed out. For Gauss-Bonnet gravity, we show that in the regime where this method is applicable, the resulting equations coincide with proposals in the literature as well as with what follows from considerations of the stress tensor on the entangling surface. Finally we demonstrate that the area functional in Gauss-Bonnet holography arises as a counterterm needed to make the Euclidean action free of power law divergences.
Casimir Energy Associated With Fractional Derivative Field
Lim, S. C. [Faculty of Engineering, Multimedia University, Cyberjaya 63100, Selangor (Malaysia)
2007-04-28
Casimir energy associated with fractional derivative scalar massless field at zero and positive temperature can be obtained using the regularization based on generalized Riemann zeta function of Epstein-Hurwitz type.
32 CFR 2001.22 - Derivative classification.
Code of Federal Regulations, 2011 CFR
2011-07-01
...Jones, Lead Analyst, Research and Analysis Division or Classified By: ID # IMN01...Imagery Acquired by Space-Based National Intelligence Reconnaissance Systems,” the derivative...prescribed by the Director of National Intelligence. (4) When determining the...
32 CFR 2001.22 - Derivative classification.
Code of Federal Regulations, 2010 CFR
2010-07-01
...Jones, Lead Analyst, Research and Analysis Division or Classified By: ID # IMN01...Imagery Acquired by Space-Based National Intelligence Reconnaissance Systems,” the derivative...prescribed by the Director of National Intelligence. (4) When determining the...
Confidence Measures Derived from an Acceptor HMM
Williams, Gethin; Renals, Steve
In this paper we define a number of confidence measures derived from an acceptor HMM and evaluate their performance for the task of utterance verification using the North American Business News (NAB) and Broadcast News ...
Analysis and the Derivation of Valid Objectives
ERIC Educational Resources Information Center
Tiemann, Philip W.
1973-01-01
Author states that "to the extent that behavioral objectives are derived from an analysis of relatively broad objectives, they can serve as valid criteria which enable our students to avoid trivia." (Author)
5 CFR 1312.7 - Derivative classification.
Code of Federal Regulations, 2012 CFR
2012-01-01
...2012-01-01 false Derivative classification. 1312.7 Section 1312.7 ...MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION, DOWNGRADING, DECLASSIFICATION...OF NATIONAL SECURITY INFORMATION Classification and Declassification of National...
5 CFR 1312.7 - Derivative classification.
Code of Federal Regulations, 2014 CFR
2014-01-01
...2014-01-01 false Derivative classification. 1312.7 Section 1312.7 ...MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION, DOWNGRADING, DECLASSIFICATION...OF NATIONAL SECURITY INFORMATION Classification and Declassification of National...
5 CFR 1312.7 - Derivative classification.
Code of Federal Regulations, 2013 CFR
2013-01-01
...2013-01-01 false Derivative classification. 1312.7 Section 1312.7 ...MANAGEMENT AND BUDGET OMB DIRECTIVES CLASSIFICATION, DOWNGRADING, DECLASSIFICATION...OF NATIONAL SECURITY INFORMATION Classification and Declassification of National...
Entropic-gravity derivation of MOND
F. R. Klinkhamer
2012-04-04
A heuristic entropic-gravity derivation has previously been given of the gravitational two-body force of modified Newtonian dynamics (MOND). Here, it is shown that also another characteristic of MOND can be recovered, namely, the external field effect (implying a violation of the Strong Equivalence Principle). In fact, the derivation gives precisely the modified Poisson equation which Bekenstein and Milgrom proposed as a consistent nonrelativistic theory of MOND.
Generalized entropy and higher derivative gravity
NASA Astrophysics Data System (ADS)
Camps, Joan
2014-03-01
We derive an extension of the Ryu-Takayanagi prescription for curvature squared theories of gravity in the bulk, and comment on a prescription for more general theories. This results in a new entangling functional, that contains a correction to Wald's entropy. The new term is quadratic in the extrinsic curvature. The coefficient of this correction is a second derivative of the lagrangian with respect to the Riemann tensor. For Gauss-Bonnet gravity, the new functional reduces to Jacobson-Myers'.
Asymptotic safety in higher-derivative gravity
Dario Benedetti; Pedro F. Machado; Frank Saueressig
2009-07-07
We study the non-perturbative renormalization group flow of higher-derivative gravity employing functional renormalization group techniques. The non-perturbative contributions to the $\\beta$-functions shift the known perturbative ultraviolet fixed point into a non-trivial fixed point with three UV-attractive and one UV-repulsive eigendirections, consistent with the asymptotic safety conjecture of gravity. The implication of this transition on the unitarity problem, typically haunting higher-derivative gravity theories, is discussed.
Special cycles and derivatives of Eisenstein series
Stephen S. Kudla
2003-01-01
This article sketches relations among algebraic cycles for the Shimura varieties defined by arithmetic quotients of symmetric domains for O(n,2), theta functions, values and derivatives of Eisenstein series and values and derivatives of certain L-functions. In the geometric case, results of joint work with John Millson imply that the generating functions for the classes in cohomology of certain algebraic cycles
Resolution enhancement in second-derivative spectra.
Czarnecki, Miros?aw A
2015-01-01
Derivative spectroscopy is a powerful tool for the resolution enhancement in infrared, near-infrared, Raman, ultraviolet-visible, nuclear magnetic resonance, electron paramagnetic resonance, and fluorescence spectroscopy. Despite its great significance in analytical chemistry, not all aspects of the applications of this method have been explored as yet. This is the first systematic study of the parameters that influence the resolution enhancement in the second derivative spectra. The derivative spectra were calculated with the Savitzky-Golay method with different window size (5, 15, 25) and polynomial order (2, 4). The results obtained in this work show that the resolution enhancement in the second derivative spectra strongly depends on the data spacing in the original spectra, window size, polynomial order, and peak profile. As shown, the resolution enhancement is related to variations in the width of the peaks upon the differentiation. The present study reveals that in order to maximize the separation of the peaks in the second derivative spectra, the original spectra should be recorded at high resolution and differentiated using a small window size and high polynomial order. However, working with the real spectra one has to compromise between the noise reduction and optimization of the resolution enhancement in the second derivative spectra. PMID:25499557
Derived Transformation of Children's Pregambling Game Playing
Dymond, Simon; Bateman, Helena; Dixon, Mark R
2010-01-01
Contemporary behavior-analytic perspectives on gambling emphasize the impact of verbal relations, or derived relational responding and the transformation of stimulus functions, on the initiation and maintenance of gambling. Approached in this way, it is possible to undertake experimental analysis of the role of verbal/mediational variables in gambling behavior. The present study therefore sought to demonstrate the ways new stimuli could come to have functions relevant to gambling without those functions being trained directly. Following a successful derived-equivalence-relations test, a simulated board game established high- and low-roll functions for two concurrently presented dice labelled with members of the derived relations. During the test for derived transformation, children were reexposed to the board game with dice labelled with indirectly related stimuli. All participants except 1 who passed the equivalence relations test selected the die that was indirectly related to the trained high-roll die more often than the die that was indirectly related to low-roll die, despite the absence of differential outcomes. All participants except 3 also gave the derived high-roll die higher liking ratings than the derived low-roll die. The implications of the findings for behavior-analytic research on gambling and the development of verbally-based interventions for disordered gambling are discussed. PMID:21541176
Influence of Different Iodide Salts on the Performance of Dye-Sensitized Solar Cells Containing studied as components of dye- sensitized solar cells (DSSCs). Electrolytes based on hexa. Introduction Dye-sensitized solar cells (DSSCs) are promising solar conversion devices that can achieve >10
Simón, Luis; Paton, Robert S
2015-03-01
We report a hybrid density functional theory-molecular mechanics study of the mechanism of the addition of nitroalkanes and phosphonates to benzaldehyde catalyzed by a chiral phosphacene catalyst developed by Ooi and co-workers. Our results are consistent with a reaction mechanism in which a catalyst molecule simultaneously interacts by hydrogen bonds with the nucleophile and the electrophile, transferring a proton to the aldehyde in concert with carbon-carbon bond formation. Despite the C2 symmetry of this class of organocatalyst, substrate recognition, and asymmetric induction in both reaction classes studied relies on interactions with nonequivalent N-H bonds that break symmetry. The origin of the stereo and diastereoselectivity is discussed in terms of steric effects and of the conformations adopted by the reactants, and the most favorable transition structure results from minimal geometric distortion energies. A rational model for predicting the major stereoisomer of reactions catalyzed by this chiral phosphacene, based on the qualitative assessment of steric interactions, is given. PMID:25658042
Development of thermally stable phosphonitrile elastomers for advanced aerospace structures
NASA Technical Reports Server (NTRS)
Reynard, K. A.; Gerber, A. H.; Peterson, T.; Rose, S. H.
1973-01-01
Both high and low molecular weight, curable poly(fluoroalkoxy phosphazene) terpolymers were prepared. These terpolymers resulted from reaction of (Cl2PNn) polymer with alkoxides derived from CF3CH2OH and C3F7CH2OH, and an alkoxide derived from CH3CH(OH)C2H4OH. The terpolymers were crosslinked with polyisocyanates at room temperature. High molecular weight materials were converted into isocyanate prepolymers which as films underwent moisture cures at room temperature. Prepolymer solutions were stable for several days, and showed good adhesion. Also the effects of polymerization of (Cl2PN)3 were studied. Purified octachlorophosphazene, thiocyanate salts, or hydrogen chloride were employed in attempts to decrease molecular weight. Hydrogen chloride was found to be a good agent for preparation of low molecular weight poly(dichloro phosphazene).
Deriving Framework Usages Based on Behavioral Models
NASA Astrophysics Data System (ADS)
Zenmyo, Teruyoshi; Kobayashi, Takashi; Saeki, Motoshi
One of the critical issue in framework-based software development is a huge introduction cost caused by technical gap between developers and users of frameworks. This paper proposes a technique for deriving framework usages to implement a given requirements specification. By using the derived usages, the users can use the frameworks without understanding the framework in detail. Requirements specifications which describe definite behavioral requirements cannot be related to frameworks in as-is since the frameworks do not have definite control structure so that the users can customize them to suit given requirements specifications. To cope with this issue, a new technique based on satisfiability problems (SAT) is employed to derive the control structures of the framework model. In the proposed technique, requirements specifications and frameworks are modeled based on Labeled Transition Systems (LTSs) with branch conditions represented by predicates. Truth assignments of the branch conditions in the framework models are not given initially for representing the customizable control structure. The derivation of truth assignments of the branch conditions is regarded as the SAT by assuming relations between termination states of the requirements specification model and ones of the framework model. This derivation technique is incorporated into a technique we have proposed previously for relating actions of requirements specifications to ones of frameworks. Furthermore, this paper discuss a case study of typical use cases in e-commerce systems.
Structure Activity Relationship of Brevenal Hydrazide Derivatives
Goodman, Allan; McCall, Jennifer R.; Jacocks, Henry M.; Thompson, Alysha; Baden, Daniel; Abraham, William M.; Bourdelais, Andrea
2014-01-01
Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model. PMID:24686558
New steroid derivative with hypoglycemic activity
Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Lenin, Hau-Heredia; Elodia, García-Cervera; Eduardo, Pool-Gómez; Marcela, Rosas-Nexticapa; Bety, Sarabia-Alcocer
2014-01-01
Data indicates that some steroid derivatives may induce changes on glucose levels; nevertheless, data are very confusing. Therefore, more pharmacological data are needed to characterize the activity induced by the steroid derivatives on glucose levels. The aim of this study was to synthesize a new steroid derivative for evaluate its hypoglycemic activity. The effects of steroid derivative on glucose concentration were evaluated in a diabetic animal model using glibenclamide and metformin as controls. In addition, the pregnenolone-dihydrotestosterone conjugate was bound to Tc-99m using radioimmunoassay methods, to evaluate the pharmacokinetics of the steroid derivative over time. The results showed that the pregnenolone-dihydrotestosterone conjugate induces changes on the glucose levels in similar form than glibenclamide. Other data showed that the biodistribution of Tc-99m-steroid derivativein brain was higher in comparison with spleen, stomach, intestine liver and kidney. In conclusion, the pregnenolone-dihydrotestosterone conjugate exerts hypoglycemic activity and this phenomenon could depend of its physicochemical properties which could be related to the degree of lipophilicity of the steroidderivative. PMID:25550906
Another derivation of generalized Langevin equations
Dengler, R
2015-01-01
The formal derivation of Langevin equations (and, equivalently Fokker-Planck equations) with projection operator techniques of Mori, Zwanzig, Kawasaki and others can well be called a pearl of theoretical physics. The derivation relies on classical mechanics, and encompasses everything an omnipotent engineer can construct from point particles and potentials: solids, liquids, liquid crystals, conductors, polymers, systems with spin-like degrees of freedom ... Einstein relations and Onsager reciprocity theorem come for free. It apparently not has widely found its way into textbooks, but has been reproduced dozens of times on the fly with many references to the literature and without adding much substantially new. Here we follow the tradition, but strive to produce a self-contained text. Furthermore, we address questions that naturally arise in the derivation. Among other things the meaning of the divergence of the Poisson brackets is explained, and the role of nonlinear damping coefficients is clarified.
Another derivation of generalized Langevin equations
R. Dengler
2015-06-08
The formal derivation of Langevin equations (and, equivalently Fokker-Planck equations) with projection operator techniques of Mori, Zwanzig, Kawasaki and others can well be called a pearl of theoretical physics. The derivation relies on classical mechanics, and encompasses everything an omnipotent engineer can construct from point particles and potentials: solids, liquids, liquid crystals, conductors, polymers, systems with spin-like degrees of freedom ... Einstein relations and Onsager reciprocity theorem come for free. It apparently not has widely found its way into textbooks, but has been reproduced dozens of times on the fly with many references to the literature and without adding much substantially new. Here we follow the tradition, but strive to produce a self-contained text. Furthermore, we address questions that naturally arise in the derivation. Among other things the meaning of the divergence of the Poisson brackets is explained, and the role of nonlinear damping coefficients is clarified.
Simple derivation of basic quadrature formulas
Talvila, Erik
2012-01-01
Simple proofs of the midpoint, trapezoidal and Simpson's rules are proved for numerical integration on a compact interval. The integrand is assumed to be twice continuously differentiable for the midpoint and trapezoidal rules, and to be four times continuously differentiable for Simpson's rule. Errors are estimated in terms of the uniform norm of second or fourth derivatives of the integrand. The proof uses only integration by parts, applied to the second or fourth derivative of the integrand, multiplied by an appropriate polynomial or piecewise polynomial function. A corrected trapezoidal rule that includes the first derivative of the integrand at the endpoints of the integration interval is also proved in this manner, the coefficient in the error estimate being smaller than for the midpoint and trapezoidal rules. The proofs are suitable for presentation in a calculus or elementary numerical analysis class. Several student projects are suggested.
Derivative expansion of the effective action
Cheyette, O.
1987-04-01
This paper describes some methods for calculating derivative terms in the one loop effective action for a quantum field theory. The functional approach and background field method are first used to derive the general form of the one loop determinant. Then the determinant is expanded in powers of derivatives of the background fields. The form of this expansion is described for the simple case of an interacting scalar field, and then for the more complicated problem of a non-abelian gauge field. Finally, the expansion is applied to the task of calculating Higgs mass dependent effects in the Glashow-Weinberg-Salam model, and all terms which grow with the Higgs mass M/sub H/ are found in the one loop approximation. The result of this calculation is used to find the dependence of the gauge boson mass ratio rho on M/sub H/, and also to estimate the size of corrections to W and Z scattering theorems.
A rigorous derivation of multicomponent diffusion laws
Zaibao Yang; Wen-An Yong; Yi Zhu
2015-02-12
This article is concerned with the dynamics of a mixture of gases. Under the assumption that all the gases are isothermal and inviscid, we show that the governing equations have an elegant conservation-dissipation structure. With the help of this structure, a multicomponent diffusion law is derived mathematically rigorously. This clarifies a long-standing non-uniqueness issue in the field for the first time. The multicomponent diffusion law derived here takes the spatial gradient of an entropic variable as the thermodynamic forces and satisfies a nonlinear version of the Onsager reciprocal relations.
High ethanol producing derivatives of Thermoanaerobacter ethanolicus
Ljungdahl, Lars G. (Athens, GA); Carriera, Laura H. (Athens, GA)
1983-01-01
Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).
Hydrogermylation of itaconic and sorbic derivatives
Gar, T.K.; Viktorov, N.A.; Nosova, V.M.; Kisin, A.V.; Ivashchenko, D.A.; Popkov, M.K.; Mironov, V.F.
1987-10-10
We have investigated the reactions of trichlorogermane with itaconic acid and its derivatives and also with derivatives of sorbic acid. It was shown that the acid chlorides and the anhydride of itaconic acid readily undergo addition with the trichlorogermane ether complex. The structures of the compounds obtained were determined by means of /sup 1/H and /sup 13/C NMR spectroscopy with the use of model compounds: 3-butenoyl chloride, methyl 3-butenoate, crotonoyl chloride, methyl crotonate, and products of the addition of trichlorogermane ether complex to the latter.
High ethanol producing derivatives of Thermoanaerobacter ethanolicus
Ljungdahl, L.G.; Carriera, L.H.
1983-05-24
Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).
Cyclodextrin derivatives as anti-infectives
Karginov, Vladimir A.
2013-01-01
Cyclodextrin derivatives can be utilized as anti-infectives with pore-forming proteins as the targets. The highly efficient selection of potent inhibitors was achieved because per-substituted cyclodextrins have the same symmetry as the target pores. Inhibitors of several bacterial toxins produced by B. anthracis, S. aureus, C. perfringens, C. botulinum and C. difficile were identified from a library of ~200 CD derivatives. It was demonstrated that multi-targeted inhibitors can be found using this approach and could be utilized for the development of broad-spectrum drugs against various pathogens. PMID:24011515
Structural studies of 4-aminoantipyrine derivatives
NASA Astrophysics Data System (ADS)
Cunha, Silvio; Oliveira, Shana M.; Rodrigues, Manoel T.; Bastos, Rodrigo M.; Ferrari, Jailton; de Oliveira, Cecília M. A.; Kato, Lucília; Napolitano, Hamilton B.; Vencato, Ivo; Lariucci, Carlito
2005-10-01
Reaction of 4-aminoantipyrine with acetylacetone, ethyl acetoacetate, benzoyl isothiocyanate, phenyl isothiocyanate, maleic anhydride and methoxymethylene Meldrum's acid afforded a series of new antipyrine derivatives. The antibacterial activity of the synthesized compounds against Micrococcus luteus ATCC 9341, Staphilococcus aureus ATCC 29737, and Escherichia coli ATCC 8739 was evaluated and the minimal inhibitory concentration determined. Modest activity was found only to the maleamic acid obtained from the reaction of 4-aminoantipyrine and maleic anhydride. 1H NMR investigation of this maleamic acid showed that it is slowly converted to the corresponding toxic maleimide. The structures of three derivatives were determined by X-ray diffraction analysis.
Some halogen derivatives of p - toluidine
Stoudt, William E.
1919-01-01
In Chemical Engineering. By William E. Stoudt June 5,1919. Approved R0Q055 3530^ i Preface. The purpose of this research was to prepare three halogen derivatives of p-toluidine,i. e.,(1) 1 amino- 2 c hi or—4 methyl "benzene, (2) 1 amino-2 brom—4... methyl benzene, (3) 1 amino-2 iodo-4 methyl benzene,and then,by preparing various reaction products of these three compounds,to deter mine the difference in reactivity of the three halogen derivatives. By this means a general idea of the effect upon...
The derivative of a continued fraction
Bowman, Kimiko o
2009-01-01
The paper considers second order continued fractions associated with (I) the Psi function {psi}(z), (II) the continued fraction component in ln {Gamma}(z) due to Stieltjes. The second order sequences k*{sub s}/k{sub s} provide approximants, some of which are remarkably close. In addition a series form for the convergent {chi}{sub s}={omega}{sub s} associated with a continued fraction provides an expression for the derivatives of a continued fraction. The implementation uses a Maple code for derivatives.
Special relativity derived from spacetime magma.
Greensite, Fred
2014-01-01
We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid) existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally. PMID:24959889
Maternally derived transferrin in pigeon squabs.
Frelinger, J A
1971-03-26
With the use of genetically marked transferrin, a major portion of circulating transferrin from a newly hatched squab was found to be derived from the mother through the egg. The transfer is not through the parental crop milk. The squab does not accumulate enough transferrin of its own making to be detectable until it is about 8 days old. The maternally derived protein remains detectable until 14 days after hatching. The squab actively synthesizes a portion its own transferrin from hatching onward. PMID:5545207
Terpenes from Marine-Derived Fungi
Ebel, Rainer
2010-01-01
Terpenes from marine-derived fungi show a pronounced degree of structural diversity, and due to their interesting biological and pharmacological properties many of them have aroused interest from synthetic chemists and the pharmaceutical industry alike. The aim of this paper is to give an overview of the structural diversity of terpenes from marine-derived fungi, highlighting individual examples of chemical structures and placing them in a context of other terpenes of fungal origin. Wherever possible, information regarding the biological activity is presented. PMID:20948911
Technology Transfer Automated Retrieval System (TEKTRAN)
Vegetable oils, their derivatives, and glycerin represent renewable raw materials that are firmly established components in many industrial products. Their use continues to be of interest to many researchers and the development of approaches to functionalize these compounds to derive oleochemicals ...
Financial Derivatives and Partial Differential Equations
Almgren, Robert F.
, loan contracts with various interest rates, energy in many forms, agricultural products, precious AND DERIVATIVES. Assets of all sorts are traded in financial markets: stocks and stock indices, foreign currencies provide a rich means for mar- ket participants to exchange risk and thereby achieve their preferred
Antifungal activity of ajoene derived from garlic.
Yoshida, S; Kasuga, S; Hayashi, N; Ushiroguchi, T; Matsuura, H; Nakagawa, S
1987-01-01
The antifungal activity of six fractions derived from garlic was investigated in an in vitro system. Ajoene had the strongest activity in these fractions. The growth of both Aspergillus niger and Candida albicans was inhibited by ajoene at less than 20 micrograms/ml. Images PMID:3555334
Simple Derivation of the Lindblad Equation
ERIC Educational Resources Information Center
Pearle, Philip
2012-01-01
The Lindblad equation is an evolution equation for the density matrix in quantum theory. It is the general linear, Markovian, form which ensures that the density matrix is Hermitian, trace 1, positive and completely positive. Some elementary examples of the Lindblad equation are given. The derivation of the Lindblad equation presented here is…
Edge Localization by Second Derivative Filters
van Vliet, Lucas J.
stacks of pillboxes to form Gaussian or Tepee filters. We refer to Chapter 2 (section 2 filter. Other filter shapes such as the Gaussian filter are constructed using a stack of pillboxes. We41 Chapter 3 Edge Localization by Second Derivative Filters In our research we study the location
Derived Transformation of Children's Pregambling Game Playing
ERIC Educational Resources Information Center
Dymond, Simon; Bateman, Helena; Dixon, Mark R.
2010-01-01
Contemporary behavior-analytic perspectives on gambling emphasize the impact of verbal relations, or derived relational responding and the transformation of stimulus functions, on the initiation and maintenance of gambling. Approached in this way, it is possible to undertake experimental analysis of the role of verbal/mediational variables in…
Enabling quaternion derivatives: the generalized HR calculus.
Xu, Dongpo; Jahanchahi, Cyrus; Took, Clive C; Mandic, Danilo P
2015-08-01
Quaternion derivatives exist only for a very restricted class of analytic (regular) functions; however, in many applications, functions of interest are real-valued and hence not analytic, a typical case being the standard real mean square error objective function. The recent HR calculus is a step forward and provides a way to calculate derivatives and gradients of both analytic and non-analytic functions of quaternion variables; however, the HR calculus can become cumbersome in complex optimization problems due to the lack of rigorous product and chain rules, a consequence of the non-commutativity of quaternion algebra. To address this issue, we introduce the generalized HR (GHR) derivatives which employ quaternion rotations in a general orthogonal system and provide the left- and right-hand versions of the quaternion derivative of general functions. The GHR calculus also solves the long-standing problems of product and chain rules, mean-value theorem and Taylor's theorem in the quaternion field. At the core of the proposed GHR calculus is quaternion rotation, which makes it possible to extend the principle to other functional calculi in non-commutative settings. Examples in statistical learning theory and adaptive signal processing support the analysis. PMID:26361555
Sol-Gel Derived Hafnia Coatings
NASA Technical Reports Server (NTRS)
Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)
2002-01-01
Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.
Kipukasins: Nucleoside derivatives from Aspergillus versicolor.
Technology Transfer Automated Retrieval System (TEKTRAN)
Seven new aroyl uridine derivatives (kipukasins A-G; 1-7) were isolated from solid-substrate fermentation cultures of two different Hawaiian isolates of Aspergillus versicolor. The structures of compounds 1-7 were determined by analysis of NMR and MS data. The nucleoside portion of lead compound 1...
Derivative expansions for affinely quantized field theories
Carl M. Bender; R. J. Rivers; C. C. Wong
1990-01-01
We examine the existence of an affinely (noncanonically) quantized free scalar theory via an expansion in powers of derivatives of the field. We show that with the simplest choice of measure affine quantization does not provide a useful basis for a nontrivial, well-defined theory.
Notes derived from Stallings book Interesting news
Klappenecker, Andreas
IPSEC Notes derived from Stallings book #12;Interesting news · BGP attack with no authentication period · Dampening leads to longer outages #12;IPSEC · Provides authentication, integrity, confidentiality at IP/network layer Transparent to Transport layer & application · SSL at Transport layer (TCP
Tectonic plate motions derived from Lageos
R. Biancale; A. Cazenave; K. Dominh
1991-01-01
Five years of laser data (1984-88) between the Lageos satellite and the ground station network based on precise monthly computations of the Lageos satellite are analyzed to recover tectonic motions affecting the stations. A global inversion over this period provides solutions for absolute velocities in latitude and longitude of a selected subset of 14 stations. Relative horizontal velocities are derived
Chromomoric acid derivatives from Tectona philippinensis.
Ragasa, Consolacion Y; Tepora, Myrna M; Espinelli, Dinah H; Mandia, Emelina H; Rideout, John A
2008-04-01
The air-dried leaves of Tectona philippinensis, an endemic and endangered Philippine medicinal tree, afforded four new chromomoric acid derivatives ( 1, 2, 3a, and 3b). Their structures were elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial testing was carried out on 1- 3 against a panel of bacteria and fungi. PMID:18278870
Speaker Recognition Using Acoustically Derived Units
1 Speaker Recognition Using Acoustically Derived Units Brett R. Wildermoth & Kuldip K. Paliwal Abstract-- The field of speaker recognition has been primarily based around text-independent systems based. INTRODUCTION THE topic of speaker recognition encompasses both speaker identification and speaker verification
Chemiluminescence of indole and its derivatives
NASA Astrophysics Data System (ADS)
Vasil'ev, Rostislav F.; Trofimov, A. V.; Tsaplev, Yuri B.
2010-02-01
The results of studies on chemiluminescence of indole and its derivatives are critically analyzed. It is shown that chemical transformations of indoles lead, depending on the structure and experimental conditions, to various electronically excited products and emission of light. Many reactions considered are used as a basis for highly sensitive methods for detection of indoles in biology, medicine, ecology and forensics.
Singlet exciton fission in a hexacene derivative.
Lee, Jiye; Bruzek, Matthew J; Thompson, Nicholas J; Sfeir, Matthew Y; Anthony, John E; Baldo, Marc A
2013-03-13
Hexacene, an acene with six benzene rings, is notable for its exceptionally small triplet energy, around one third of the singlet energy. Herein, singlet fission, i.e., conversion of a singlet exciton into two triplets, is demonstrated in a thin film of hexacene derivative, employing both transient absorption spectroscopy and magnetic field effects on photocurrent. PMID:23293054
Enabling quaternion derivatives: the generalized HR calculus
Xu, Dongpo; Jahanchahi, Cyrus; Took, Clive C.; Mandic, Danilo P.
2015-01-01
Quaternion derivatives exist only for a very restricted class of analytic (regular) functions; however, in many applications, functions of interest are real-valued and hence not analytic, a typical case being the standard real mean square error objective function. The recent HR calculus is a step forward and provides a way to calculate derivatives and gradients of both analytic and non-analytic functions of quaternion variables; however, the HR calculus can become cumbersome in complex optimization problems due to the lack of rigorous product and chain rules, a consequence of the non-commutativity of quaternion algebra. To address this issue, we introduce the generalized HR (GHR) derivatives which employ quaternion rotations in a general orthogonal system and provide the left- and right-hand versions of the quaternion derivative of general functions. The GHR calculus also solves the long-standing problems of product and chain rules, mean-value theorem and Taylor's theorem in the quaternion field. At the core of the proposed GHR calculus is quaternion rotation, which makes it possible to extend the principle to other functional calculi in non-commutative settings. Examples in statistical learning theory and adaptive signal processing support the analysis. PMID:26361555
Derivative Free Gradient Projection Algorithms for Rotation
ERIC Educational Resources Information Center
Jennrich, Robert I.
2004-01-01
A simple modification substantially simplifies the use of the gradient projection (GP) rotation algorithms of Jennrich (2001, 2002). These algorithms require subroutines to compute the value and gradient of any specific rotation criterion of interest. The gradient can be difficult to derive and program. It is shown that using numerical gradients…
Cellulose Derivatives for Water Repellent Properties
Technology Transfer Automated Retrieval System (TEKTRAN)
In this poster presentation, we will discuss the synthesis and structural characterizations of nitro-benzyl cellulose (1), amino-benzyl cellulose (2) and pentafluoro –benzyl cellulose (3). All cellulose derivatives are synthesized by etherification process in lithium chloride/N,N-dimethylacetamide h...
New coumarin derivative from Euphorbia wallichii.
Xu, Wen-Hui; Shen, Yun-Heng; Liang, Qian; Zhao, Ping
2015-10-01
One new coumarin derivative (1) and two known compounds, quercetin (2) and glyceraldehyde (3) have been isolated from the whole plants of Euphorbia wallichii. Their structures were elucidated by means of extensive spectroscopic analysis (NMR and ESI-MS) and by comparison with data reported in the literature. This is the first isolation of dihydrocoumarin (1) from the genus of Euphorbia. PMID:25613835
High speed point derivative microseismic detector
Uhl, J.E.; Warpinski, N.R.; Whetten, E.B.
1998-06-30
A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves. 9 figs.
High speed point derivative microseismic detector
Uhl, James Eugene (Albuquerque, NM); Warpinski, Norman Raymond (Albuquerque, NM); Whetten, Ernest Blayne (Albuquerque, NM)
1998-01-01
A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves.
Azulene Derivatives as Plant Growth Regulators
Robert M. Muir
1961-01-01
AMONG the many hundreds of compounds examined for effects in promoting cell elongation, very few having activity do not have a ring structure possessing aromatic character1. Thus it is logical to look for activity in compounds having `non-classical' aromatic rings such as derivatives of azulene and ferrocene. The azulene compounds are of particular significance since this ring system occurs frequently
Ecosystem Services Derived from Headwater Catchments
We used data from the USEPA’s wadeable streams assessment (WSA), US Forest Service’s forest inventory and analysis (FIA), and select USFS experimental forests (EF) to investigate potential ecosystems services derived from headwater catchments. C, N, and P inputs to these catchmen...
Modelling and Simulating of Rain Derivatives
Modelling and Simulating of Rain Derivatives Master thesis Cathrin van Emmerich Supervisor of a European put . . . . . . . . . . . . . . . . 3 2.1 Rain, Schleswig, 1947-2003, 7-days-intervals . . . . . . . . . . 8 2.2 Rain, Schleswig, 1980-2003, 28-days-intervals . . . . . . . . . . 9 2.3 Rain, Schleswig, 1992
CORD BLOOD EXPANSION Pyrimidoindole derivatives are
Zandstra, Peter W.
CORD BLOOD EXPANSION Pyrimidoindole derivatives are agonists of human hematopoietic stem cell self number of hematopoietic stem and progenitor cells in cord blood units limits their widespread use the expansion ex vivo of human cord blood cells capable of reconstituting human hematopoiesis for at least 6
Alternative Derivations for the Poisson Integral Formula
ERIC Educational Resources Information Center
Chen, J. T.; Wu, C. S.
2006-01-01
Poisson integral formula is revisited. The kernel in the Poisson integral formula can be derived in a series form through the direct BEM free of the concept of image point by using the null-field integral equation in conjunction with the degenerate kernels. The degenerate kernels for the closed-form Green's function and the series form of Poisson…
An accelerated subspace iteration for eigenvector derivatives
NASA Technical Reports Server (NTRS)
Ting, Tienko
1991-01-01
An accelerated subspace iteration method for calculating eigenvector derivatives has been developed. Factors affecting the effectiveness and the reliability of the subspace iteration are identified, and effective strategies concerning these factors are presented. The method has been implemented, and the results of a demonstration problem are presented.
Curcumin derivatives as HIV-1 protease inhibitors
Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)
1993-12-31
Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.
Derivative of Map of Banach algebra
Aleks Kleyn
2015-05-14
Let $A$ be Banach algebra over commutative ring $D$. The map $f:A\\rightarrow A\\ $ is called differentiable in the Gateaux sense, if $$f(x+a)-f(x)=\\partial f(x)\\circ a+o(a)$$ where the Gateaux derivative $\\partial f(x)$ of map $f$ is linear map of increment $a$ and $o$ is such continuous map that $$ \\lim_{a\\rightarrow 0}\\frac{|o(a)|}{|a|}=0 $$ Assuming that we defined the Gateaux derivative $\\partial^{n-1} f(x)$ of order $n-1$, we define $$ \\partial^n f(x)\\circ(a_1\\otimes...\\otimes a_n) =\\partial(\\partial^{n-1} f(x)\\circ(a_1\\otimes...\\otimes a_{n-1}))\\circ a_n $$ the Gateaux derivative of order $n$ of map $f$. Since the map $f(x)$ has all derivatives, then the map $f(x)$ has Taylor series expansion $$ f(x)=\\sum_{n=0}^{\\infty}(n!)^{-1}\\partial^n f(x_0)\\circ(x-x_0)^n $$
Two-point derivative dispersion relations
NASA Astrophysics Data System (ADS)
Ferreira, Erasmo; Sesma, Javier
2013-03-01
A new derivation is given for the representation, under certain conditions, of the integral dispersion relations of scattering theory through local forms. The resulting expressions have been obtained through an independent procedure to construct the real part and consist of new mathematical structures of double infinite summations of derivatives. In this new form the derivatives are calculated at the generic value of the energy E and separately at the reference point E = m that is the lower limit of the integration. This new form may be more interesting in certain circumstances and directly shows the origin of the difficulties in convergence that were present in the old truncated forms called standard-derivative dispersion relations (DDR). For all cases in which the reductions of the double to single sums were obtained in our previous work, leading to explicit demonstration of convergence, these new expressions are seen to be identical to the previous ones. We present, as a glossary, the most simplified explicit results for the DDR's in the cases of imaginary amplitudes of forms (E/m)?[ln (E/m)]n that cover the cases of practical interest in particle physics phenomenology at high energies. We explicitly study the expressions for the cases with ? negative odd integers, that require identification of cancelation of singularities, and provide the corresponding final results.
Biodegradable polymers derived from amino acids.
Khan, Wahid; Muthupandian, Saravanan; Farah, Shady; Kumar, Neeraj; Domb, Abraham J
2011-12-01
In the past three decades, the use of polymeric materials has increased dramatically for biomedical applications. Many ?-amino acids derived biodegradable polymers have also been intensely developed with the main goal to obtain bio-mimicking functional biomaterials. Polymers derived from ?-amino acids may offer many advantages, as these polymers: (a) can be modified further to introduce new functions such as imaging, molecular targeting and drugs can be conjugated chemically to these polymers, (b) can improve on better biological properties like cell migration, adhesion and biodegradability, (c) can improve on mechanical and thermal properties and (d) their degradation products are expected to be non-toxic and readily metabolized/excreted from the body. This manuscript focuses on biodegradable polymers derived from natural amino acids, their synthesis, biocompatibility and biomedical applications. It is observed that polymers derived from ?-amino acids constitute a promising family of biodegradable materials. These provide innovative multifunctional polymers possessing amino acid side groups with biological activity and with innumerous potential applications. PMID:22052719
Deriving competencies from the SWEBOK ontology
Elena Men; María Pareja; Miguel-Angel Sicilia; Elena García-Barriocanal
Competencies can be used as a modeling paradigm for observable professional behavior. Competencies relate different kinds of human knowledge to practical work situations, and thus the knowledge captured in representations as ontologies can be used as a source for deriving competencies. However, this requires some specific support and the definition of knowledge representations for the different kinds of human capabilities.
Robust Derivation of Risk Reduction Strategies
NASA Technical Reports Server (NTRS)
Richardson, Julian; Port, Daniel; Feather, Martin
2007-01-01
Effective risk reduction strategies can be derived mechanically given sufficient characterization of the risks present in the system and the effectiveness of available risk reduction techniques. In this paper, we address an important question: can we reliably expect mechanically derived risk reduction strategies to be better than fixed or hand-selected risk reduction strategies, given that the quantitative assessment of risks and risk reduction techniques upon which mechanical derivation is based is difficult and likely to be inaccurate? We consider this question relative to two methods for deriving effective risk reduction strategies: the strategic method defined by Kazman, Port et al [Port et al, 2005], and the Defect Detection and Prevention (DDP) tool [Feather & Cornford, 2003]. We performed a number of sensitivity experiments to evaluate how inaccurate knowledge of risk and risk reduction techniques affect the performance of the strategies computed by the Strategic Method compared to a variety of alternative strategies. The experimental results indicate that strategies computed by the Strategic Method were significantly more effective than the alternative risk reduction strategies, even when knowledge of risk and risk reduction techniques was very inaccurate. The robustness of the Strategic Method suggests that its use should be considered in a wide range of projects.
On Flat Polyhedra deriving from Alexandrov's Theorem
O'Rourke, Joseph
, there can be at most four fold-points [DO07, Lem. 25.3.1], because the Gauss-Bonnet Theorem limits the totalOn Flat Polyhedra deriving from Alexandrov's Theorem Joseph O'Rourke July 14, 2010 Abstract We show that there is a straightforward algorithm to determine if the polyhedron guaranteed to exist by Alexandrov's gluing theorem
Derived brackets Yvette Kosmann-Schwarzbach
Kosmann-Schwarzbach, Yvette
, and their properties. We recall and compare the constructions of Buttin and of Vinogradov, and we prove that the Vinogradov bracket is the skew-symmetrization of a derived bracket. Odd (resp., even) Poisson brackets. Vinogradov [55] who introduced a very powerful tool under the unfortunate term of "lievization
Comprehension by Derivation Douglas R. Smith
Comprehension by Derivation Douglas R. Smith Kestrel Institute 3260 Hillview Avenue Palo Alto, California 94304 USA smith@kestrel.edu Abstract We argue that to comprehend a software system is to have, and evolution. Our work at Kestrel Institute has focused on ways to mecha- nize the development and evolution
Deriving Efficient Parallel Programs for Complex Recurrences
Teo, Yong-Meng
Deriving Efficient Parallel Programs for Complex Recurrences W.N. CHIN* S.H. TAN and Y.M. TEO, it is quite easy to apply a data type transformation to change the sum function to use the array type (or the above form of pattern-matching as syntactic sugar for the array-type, where xr++xs would de- note
Deriving Efficient Parallel Programs for Complex Recurrences
Chin, Wei Ngan
Deriving Efficient Parallel Programs for Complex Recurrences W.N. CHIN \\Lambda Hitachi Advanced type transformation to change the sum function to use the array type (or binary tree typematching as syntactic sugar for the arraytype, where xr++xs would denote the splitting of an nitem array into two subarrays
Maternally Derived Transferrin in Pigeon Squabs
Jeffrey A. Frelinger
1971-01-01
With the use of genetically marked transferrin, a major portion of circulating transferrin from a newly hatched squab was found to be derived from the mother through the egg. The transfer is not through the parental crop milk. The squab does not accumulate enough transferrin of its own making to be detectable until it is about 8 days old. The
Leading Edge Democracy Derived? New Trajectories
, United States policy pro- hibits research on human embryos and restricts federal funding to hESC linesLeading Edge Commentary Democracy Derived? New Trajectories in Pluripotent Stem Cell Research University Center for Biomedical Ethics Program on Stem Cells and Society, Stanford University, Stanford, CA
Deriving User Interfaces from Task Models
Andreas Wolff; Peter Forbrig
This position paper presents our view on model driven user interface development and relates it to other approaches. Our methodology is based on task models that are attributed and merged with a navigational model to derive user interface models. A toolset to support this development approach is introduced which is well-integrated and itself based on the eclipse modeling framework EMF.
Computing Airplane Stopping Distance: Applications of Derivatives.
ERIC Educational Resources Information Center
Tylee, J. Louis
1997-01-01
Presents two real world applications that use derivatives and are related to computing the distance required to stop an airplane. Examines the curve-fitting techniques used to develop an equation for braking force and develops equations for the deceleration and speed. (DDR)
DERIVING TECHNOLOGY ROADMAPS WITH TECH MINING TECHNIQUES
Fu-ren Lin; Chih-ping Wei; Yu-kai Lin; Yu-liang Shyu
2008-01-01
Technology monitoring has been a knowledge intensive and time-consuming task for IT managers or domain experts. Tech mining techniques can be used to mitigate these efforts. This paper proposes a technology monitoring framework based on tech mining techniques to facilitate the derivative of information and communication technology (ICT) roadmaps. With this framework, a tech mining engine is able to allocate
Macrobiotic Vertical Transport of Litter Derived Carbon
Post, Wilfred M.
Macrobiotic Vertical Transport of Litter Derived Carbon (Earthworm Phase) Mac Callaham Corey Babb Paul Hanson Don Todd USDA Forest Service and ORNL #12;Why Earthworms? · Large biomass in temperate Epigeic - Feed on fresh litter, rarely enter mineral soil layers Anecic - Build deep permanent burrows
Activated Boron Nitride Derived from Activated Carbon
Zettl, Alex
Activated Boron Nitride Derived from Activated Carbon Wei-Qiang Han,, R. Brutchey,§ T. D. Tilley substitution reaction has been used to synthesize activated boron nitride (BN). The resulting material Hexagonal boron nitride (BN), a material structurally closely related to graphite, has an attractive
Derivative luminescence spectra in lanthanide analysis
Bel'tyukova, S.V.; Poluektov, N.S.; Tochidlovskaya, T.L.; Kucher, A.A.
1987-06-01
This communication presents the results of derivative spectroscopic study of luminescence of complex compounds of europium and terbium. Solutions of complexes of europium with ethylenediaminetetraacetate, thenoyltrifluoroacetone, dibenzoylmethane, salicylate and 1,10-phenanthroline, and of terbium with phenyl ester of salicyclic acid and nalidixic acid were investigated.
NASA Astrophysics Data System (ADS)
Yamamoto, Hiroki; Kudo, Hiroto; Kozawa, Takahiro
2014-03-01
Novel resist materials are required for lithographic processing with ionization radiation such as extreme ultraviolet (EUV) and electron beam (EB) exposure tool. In this study, we developed positive-tone chemically amplified molecular resists based on noria derivatives and calixarene derivatives and evaluated the lithographic performance using EUV and EB. We make clear that a small change in modification of noria resists can cause a significant change of sensitivity. Especially, it is useful for the improvement of resist sensitivities to use protecting groups such as 2-acetyloxy-2-methyladamantyl ester (AD) groups and ethoxy groups. Also, novel calixarene derivative such as pillar[5]arene protected by AD showed a semi-isolated pattern with the line width of 40 nm (pitch: 100nm). Noria derivatives and calixarene derivative resists were promising candidates because of high sensitivity, high resolution and etch durability similar to conventional resist such as ZEP 520A and UVIII.
Zhao, Dong-Lin; Shao, Chang-Lun; Zhang, Qiang; Wang, Kai-Ling; Guan, Fei-Fei; Shi, Ting; Wang, Chang-Yun
2015-09-25
Three new azaphilone derivatives, pinophilins D-F (1-3), and one new diphenyl ether derivative, hydroxypenicillide (10), together with nine known compounds (4-9, 11-13), were isolated from the gorgonian-derived fungus Penicillium pinophilum XS-20090E18. Their structures including absolute configurations were determined by spectroscopic data, chemical conversions, the ECD exciton chirality method, and ECD calculations. Compounds 10-13 exhibited inhibitory activity against the larval settlement of the barnacle Balanus amphitrite at nontoxic concentrations. Compounds 10 and 11 showed cytotoxicity against Hep-2, RD, and HeLa cell lines. PMID:26291474
Synthesis and Antidiabetic Evaluation of Benzenesulfonamide Derivatives
Hosseinzadeh, Nouraddin; Seraj, Soodeh; Bakhshi-Dezffoli, Mohamad Ebrahim; Hasani, Mohammad; Khoshneviszadeh, Mehdi; Fallah-Bonekohal, Saeed; Abdollahi, Mohammad; Foroumadi, Alireza; Shafiee, Abbas
2013-01-01
The complex metabolic syndrome, diabetes mellitus, is a major human health concern in the world and is estimated to affect 300 million people by the year 2025. Several drugs such as sulfonylureas and biguanides are presently available to reduce hyperglycemia in diabetes mellitus. These drugs have side effects and thus searching for a new class of compounds is essential to overcome this problems. A series of seven novel N-(4-phenylthiazol-2-yl)benzenesulfonamides derivatives were synthesized and assayed in-vivo to investigate their antidiabetic activities by streptozotocin-induced model in rat. These derivatives showed considerable biological efficacy when compared to glibenclamide, a potent and well-known antidiabetic agent, as a reference drug. Four of the compounds were effective, amongst which 13 show more prominent activity at 100 mg/Kg p.o. The experimental results are statistically significant at p < 0.05 level. PMID:24250607
Symbolic derivation of potential based constitutive equations
NASA Astrophysics Data System (ADS)
Arnold, S. M.; Tan, H. Q.
1990-05-01
Structural alloys used in high temperature applications exhibit complex thermomechanical behavior that is inherently time dependent and hereditary, as the current behavior depends not only on current conditions but on the thermomechanical history. Derivation of mathematical expressions (constitutive equations) which describe this high temperature material behavior can be quite time consuming, involved, and error-prone, thus intelligent application of symbolic systems to facilitate this tedious processes can be of significant benefit. Here a computerized package, running under MACSYMA, capable of efficiently deriving potential based constitutive models, in analytical form (involving tensors, partial differentiation, invariants, and the like) is presented. Special purpose utility algorithms are designed and implemented to perform partial differentiation (chain rule), tensor manipulation, case distinction and simplification. Four constitutive theories reported in the literature are utilized to verify implementation accuracy. It is expected that this symbolic package can and will provide a significant incentive to the development of new constitutive theories.
A derivative standard for polarimeter calibration
Mulhollan, G.; Clendenin, J.; Saez, P. [and others
1996-10-01
A long-standing problem in polarized electron physics is the lack of a traceable standard for calibrating electron spin polarimeters. While several polarimeters are absolutely calibrated to better than 2%, the typical instrument has an inherent accuracy no better than 10%. This variability among polarimeters makes it difficult to compare advances in polarized electron sources between laboratories. The authors have undertaken an effort to establish 100 nm thick molecular beam epitaxy grown GaAs(110) as a material which may be used as a derivative standard for calibrating systems possessing a solid state polarized electron source. The near-bandgap spin polarization of photoelectrons emitted from this material has been characterized for a variety of conditions and several laboratories which possess well calibrated polarimeters have measured the photoelectron polarization of cathodes cut from a common wafer. Despite instrumentation differences, the spread in the measurements is sufficiently small that this material may be used as a derivative calibration standard.
Microscopic derivation of open quantum walks
NASA Astrophysics Data System (ADS)
Sinayskiy, Ilya; Petruccione, Francesco
2015-09-01
Open quantum walks (OQWs) are exclusively driven by dissipation and are formulated as completely positive trace-preserving (CPTP) maps on underlying graphs. The microscopic derivation of discrete and continuous-in-time OQWs is presented. It is assumed that connected nodes are weakly interacting via a common bath. The resulting reduced master equation of the quantum walker on the lattice is in the generalized master equation form. The time discretization of the generalized master equation leads to the OQW formalism. The explicit form of the transition operators establishes a connection between dynamical properties of the OQWs and thermodynamical characteristics of the environment. The derivation is demonstrated for the examples of the OQW on a circle of nodes and on a finite chain of nodes. For both examples, a transition between diffusive and ballistic quantum trajectories is observed and found to be related to the temperature of the bath.
Hydrocarbon and nonhydrocarbon derivatives of cyclopropane
NASA Technical Reports Server (NTRS)
Slabey, Vernon A; Wise, Paul H; Gibbons, Louis C
1953-01-01
The methods used to prepare and purify 19 hydrocarbon derivatives of cyclopropane are discussed. Of these hydrocarbons, 13 were synthesized for the first time. In addition to the hydrocarbons, six cyclopropylcarbinols, five alkyl cyclopropyl ketones, three cyclopropyl chlorides, and one cyclopropanedicarboxylate were prepared as synthesis intermediates. The melting points, boiling points, refractive indices, densities, and, in some instances, heats of combustion of both the hydrocarbon and nonhydrocarbon derivatives of cyclopropane were determined. These data and the infrared spectrum of each of the 34 cyclopropane compounds are presented in this report. The infrared absorption bands characteristic of the cyclopropyl ring are discussed, and some observations are made on the contribution of the cyclopropyl ring to the molecular refractions of cyclopropane compounds.
Photophysics and photochemistry of naphthoxazinone derivatives.
Nonell, Santi; Ferreras, Lourdes R; Cañete, Alvaro; Lemp, Else; Günther, German; Pizarro, Nancy; Zanocco, Antonio L
2008-07-18
The photophysics and photochemistry of a series of naphthoxazinones have been studied using a combination of methods ranging from steady-state and time-resolved spectroscopic techniques to product analysis. The photophysics of naphthoxazinone derivatives is very dependent on the structure: phenanthrene-like compounds exhibit higher fluorescence quantum yield than the less aromatic anthracene-like homologous. The latter, exhibit a substantial degree of charge transfer in the excited singlet state. These compounds are fairly photostable in the absence of additives, yielding a single photoproduct arising from the triplet state. The presence of electron donors such as amines increases the photoconsumption quantum yield and changes the product distribution, the primary photoproduct being a dihydronaphthoxazinone that photoreacts further yielding ultimately an oxazoline derivative. PMID:18553978
Efficient synthesis of highly substituted tetrahydroindazolone derivatives.
Scala, Angela; Piperno, Anna; Risitano, Francesco; Cirmi, Santa; Navarra, Michele; Grassi, Giovanni
2015-08-01
A straightforward and efficient method for the synthesis of novel highly substituted and diversely functionalized indazolone derivatives has been developed. The transformation consists of a cyclocondensation of selected 1,3,3'-tricarbonyls with monosubstituted hydrazines. The starting ?-triketones were prepared by an efficient chemo- and regioselective method under MW irradiation, exploiting the oxazolone chemistry. The reaction is easily accomplished under mild conditions and appears versatile, providing a synthetic diversification method with potential for drug-like compounds preparation. PMID:25784276
Antiaggregant activity of a new benzimidazole derivative.
Kucheryavenko, A F; Spasov, A A; Petrov, V I; Anisimova, V A
2014-04-01
Antiaggregant activity of a new tricyclic benzimidazole derivative, RU-891 compound, was studied on the model of ADP-induced platelet aggregation in vitro and intravascular platelet aggregation in vivo. We evaluated the effect of this substance on blood coagulation potential. Antiaggregant agent acetylsalicylic acid was used as the reference drug. RU-891 produced a dose-dependent antiaggregant effect in vivo and in vitro that exceeded the effect of the reference drug. This compound did not modulate blood coagulation potential. PMID:24824700
Fullerene derivatives with increased dielectric constants.
Jahani, Fatemeh; Torabi, Solmaz; Chiechi, Ryan C; Koster, L Jan Anton; Hummelen, Jan C
2014-09-21
The invention of new organic materials with high dielectric constants is of extreme importance for the development of organic-based devices such as organic solar cells. We report on a synthetic way to increase the dielectric constant of fullerene derivatives. It is demonstrated that introducing triethylene glycol monoethyl ether (teg) side chains into fulleropyrrolidines increases the dielectric constant by ~46 percent without devaluation of optical properties, electron mobility and the energy level of the compound. PMID:25075465
Silazane derived ceramics and related materials
Edwin Kroke; Ya-Li Li; Christoph Konetschny; Emmanuel Lecomte; Claudia Fasel; Ralf Riedel
2000-01-01
This review highlights the synthesis, processing and properties of non-oxide silicon-based ceramic materials derived from silazanes and polysilazanes. A comprehensive summary of the preparation of precursor compounds containing Si–N–Si units, including commercially available materials, is followed by the discussion of various processing techniques. The fabrication of dense bulk ceramics in the Si\\/E\\/C\\/N systems is reported which involves cross-linking of the
Triamine chelants, their derivatives, complexes and conjugates
Troutner, D.E.; John, C.S.; Pillai, M.R.A.
1995-03-07
A group of functionalized triamine chelants and their derivatives that form complexes with radioactive metal ions are disclosed. The complexes can be covalently attached to a protein or an antibody or antibody fragment and used for therapeutic and/or diagnostic purposes. The chelants are of the formula, as shown in the accompanying diagrams, wherein n, m, R, R{sup 1}, R{sup 2} and L are defined in the specification.
REDUCTION OF DERIVED HOCHSCHILD FUNCTORS OVER ...
2012-01-09
Jan 9, 2012 ... phisms after localization at every n ? Spec P. Fix one, then set T = Pm, R = Pe ...... functor Rf? : Dqc(X) ? Dqc(Y ) and its left adjoint, the left-derived ..... this just means that for a multiplicative system M in a ring B, and a BM -ideal J ..... and E . Via the above sequence of isomorphisms, the source and target ...
Higher Derivative BLG: Lagrangian and Supersymmetry Transformations
Paul Richmond
2012-07-05
Working to lowest non-trivial order in fermions, we consider the four-derivative order corrected Lagrangian and supersymmetry transformations of the Euclidean Bagger-Lambert-Gustavsson theory. By demonstrating supersymmetric invariance of the Lagrangian we determine all numerical coefficients in the system. In addition, the supersymmetry algebra is shown to close on the scalar and gauge fields. We also comment on the extension to Lorentzian and other non-Euclidean $\\mathcal{N}=8$ 3-algebra theories.
Higher Derivative BLG: Lagrangian and Supersymmetry Transformations
Richmond, Paul
2012-01-01
Working to lowest non-trivial order in fermions, we consider the four-derivative order corrected Lagrangian and supersymmetry transformations of the Euclidean Bagger-Lambert-Gustavsson theory. By demonstrating supersymmetric invariance of the Lagrangian we determine all numerical coefficients in the system. In addition, the supersymmetry algebra is shown to close on the scalar and gauge fields. We also comment on the extension to Lorentzian and other non-Euclidean $\\mathcal{N}=8$ 3-algebra theories.
Derivation of plutonium-239 materials disposition categories
Brough, W.G.
1995-04-27
At this time, the Office of Fissile Materials Disposition within the DOE, is assessing alternatives for the disposition of excess fissile materials. To facilitate the assessment, the Plutonium-Bearing Materials Feed Report for the DOE Fissile Materials Disposition Program Alternatives report was written. The development of the material categories and the derivation of the inventory quantities associated with those categories is documented in this report.
Lectures on Derived Categories Dragan Milicic
Milicic, Dragan
.1.1. Theorem. There exist a category A[S-1 ] and a functor Q : A - A[S-1 ] such that (i) Q(s) is an isomorphismC . Therefore, H and G are isomorphisms of categories. It remains to establish the existence of A[S-1 ]. We putLectures on Derived Categories Dragan MiliciÂ´c #12;#12;Contents Chapter 1. Localization
Coal-derived humus: plant growth effects
P. G. Freeman; W. W. Fowkes
1968-01-01
The growth-promoting properties of coal-derived humus were tested by a variety of bioassay methods. Humate materials used included leonardite, a form of naturally oxidized lignite, and humic acids extracted from leonardite. It was found that the greatest effects were evident when water-soluble humic acid was applied to excised root tips. No significant short-term effect was noted when water-soluble humic acid
Benzoic acid derivatives from Stocksia brahuica
Zulfiqar Ali; Viqar Uddin Ahmad; Muhammad Zahid; Rasool Bakhsh Tareen
1998-01-01
Two new benzoic acid derivatives, ethyl 3,5-dihydroxy-4-methoxybenzoate and 2-hydroxy-3-methylbenzoic acid, have been isolated from the aerial parts of Stocksia brahuica. They have been identified by mass and NMR spectroscopy. 3,4,5-Trihydroxybenzoic acid, 3,4,5-trimethoxybenzoic acid, methyl 4-hydroxybenzoate and n-propyl 4-hydroxybenzoate have also been isolated for the first time from this source.
New Eucalyptus tar-derived polyurethane coatings
Renata Costa Silva Araújo; Vânya Márcia Duarte Pasa
2004-01-01
Varying proportions of Eucalyptus tar derivatives (biopitch and heavy oil), along with castor oil, have been used to synthesize polyurethane coatings. Two-compound polyurethanes have been obtained using MDI (4,4?-methane diphenyl diisocyanate) and DBTDL (dibutyl tin dilaurate) as catalyst, and an NCO\\/OH ratio of 1.0. Two coatings systems have been obtained – a varnish based on tar oil and a black
KPZ formula derived from Liouville heat kernel
Nathanaël Berestycki; Christophe Garban; Rémi Rhodes; Vincent Vargas
2014-06-27
In this paper, we establish the Knizhnik--Polyakov--Zamolodchikov (KPZ) formula of Liouville quantum gravity, using the heat kernel of Liouville Brownian motion. This derivation of the KPZ formula was first suggested by F. David and M. Bauer in order to get a geometrically more intrinsic way of measuring the dimension of sets in Liouville quantum gravity. We also provide a careful study of the (no)-doubling behaviour of the Liouville measures in the appendix, which is of independent interest.
Eosinophil Secretion of Granule-Derived Cytokines
Spencer, Lisa A.; Bonjour, Kennedy; Melo, Rossana C. N.; Weller, Peter F.
2014-01-01
Eosinophils are tissue-dwelling leukocytes, present in the thymus, and gastrointestinal and genitourinary tracts of healthy individuals at baseline, and recruited, often in large numbers, to allergic inflammatory foci and sites of active tissue repair. The biological significance of eosinophils is vast and varied. In health, eosinophils support uterine and mammary gland development, and maintain bone marrow plasma cells and adipose tissue alternatively activated macrophages, while in response to tissue insult eosinophils function as inflammatory effector cells, and, in the wake of an inflammatory response, promote tissue regeneration, and wound healing. One common mechanism driving many of the diverse eosinophil functions is the regulated and differential secretion of a vast array of eosinophil-derived cytokines. Eosinophils are distinguished from most other leukocytes in that many, if not all, of the over three dozen eosinophil-derived cytokines are pre-synthesized and stored within intracellular granules, poised for very rapid, stimulus-induced secretion. Eosinophils engaged in cytokine secretion in situ utilize distinct pathways of cytokine release that include classical exocytosis, whereby granules themselves fuse with the plasma membrane and release their entire contents extracellularly; piecemeal degranulation, whereby granule-derived cytokines are selectively mobilized into vesicles that emerge from granules, traverse the cytoplasm and fuse with the plasma membrane to release discrete packets of cytokines; and eosinophil cytolysis, whereby intact granules are extruded from eosinophils, and deposited within tissues. In this latter scenario, extracellular granules can themselves function as stimulus-responsive secretory-competent organelles within the tissue. Here, we review the distinctive processes of differential secretion of eosinophil granule-derived cytokines. PMID:25386174
Evaluation of systematically derived neutron kinetics models
A. F. V. Dias; A. F. Henry
1987-01-01
The point kinetics model for nuclear reactors can be derived in a formally exact way by defining an amplitude function T\\/sub t\\/ (a weighted sum of all the neutrons present in the reactor at time t) and a shape function (the time-dependent, space-energy distribution of neutron flux divided by T\\/sub t\\/). For many transients the shape function remains fairly constant
Triamine chelants, their derivatives, complexes and conjugates
Troutner, David E. (Phoenixville, PA); John, Christy S. (Gaithersburg, MD); Pillai, Maroor R. A. (Vashi, IN)
1995-01-01
A group of functionalized triamine chelants and their derivatives that form complexes with radioactive metal ions are disclosed. The complexes can be covalently attached to a protein or an antibody or antibody fragment and used for therapeutic and/or diagnostic purposes. The chelants are of the formula: ##STR1## wherein n, m, R, R.sup.1, R.sup.2 and L are defined in the specification.
Stilbene derivatives from Gnetum gnemon Linn.
Iliya, Ibrahim; Ali, Zulfiqar; Tanaka, Toshiyuki; Iinuma, Munekazu; Furusawa, Miyuki; Nakaya, Ken-ichi; Murata, Jin; Darnaedi, Dedy; Matsuura, Nobuyasu; Ubukata, Makoto
2003-02-01
Four stilbene derivatives, gnemonols K and L (resveratrol trimers), M (isorhapontigenin dimer), and gnemonoside K (glucoside of resveratrol trimer) together with eleven known stilbenoids and a lignan were isolated from the acetone, methanol and 70% methanol soluble parts of the root of Gnetum gnemon (Gnetaceae). The structures of the isolates were determined by spectral analysis. The antioxidant activity of the stilbenoids on lipid peroxide inhibition and super oxide scavenging activity were also investigated. PMID:12560033
Derivation of the null energy condition
NASA Astrophysics Data System (ADS)
Parikh, Maulik; van der Schaar, Jan Pieter
2015-04-01
We derive the null energy condition, understood as a constraint on the Einstein-frame Ricci tensor, from world sheet string theory. For a closed bosonic string propagating in a curved geometry, the spacetime interpretation of the Virasoro constraint condition is precisely the null energy condition, to leading nontrivial order in the ?' expansion. Thus the deepest origin of the null energy condition lies in world sheet diffeomorphism invariance.
Uncertainty estimates for derivatives and intercepts
Clark, E.L.
1994-09-01
Straight line least squares fits of experimental data are widely used in the analysis of test results to provide derivatives and intercepts. A method for evaluating the uncertainty in these parameters is described. The method utilizes conventional least squares results and is applicable to experiments where the independent variable is controlled, but not necessarily free of error. A Monte Carlo verification of the method is given.
Small RNAs derived from snoRNAs.
Taft, Ryan J; Glazov, Evgeny A; Lassmann, Timo; Hayashizaki, Yoshihide; Carninci, Piero; Mattick, John S
2009-07-01
Small nucleolar RNAs (snoRNAs) guide RNA modification and are localized in nucleoli and Cajal bodies in eukaryotic cells. Components of the RNA silencing pathway associate with these structures, and two recent reports have revealed that a human and a protozoan snoRNA can be processed into miRNA-like RNAs. Here we show that small RNAs with evolutionary conservation of size and position are derived from the vast majority of snoRNA loci in animals (human, mouse, chicken, fruit fly), Arabidopsis, and fission yeast. In animals, sno-derived RNAs (sdRNAs) from H/ACA snoRNAs are predominantly 20-24 nucleotides (nt) in length and originate from the 3' end. Those derived from C/D snoRNAs show a bimodal size distribution at approximately 17-19 nt and >27 nt and predominantly originate from the 5' end. SdRNAs are associated with AGO7 in Arabidopsis and Ago1 in fission yeast with characteristic 5' nucleotide biases and show altered expression patterns in fly loquacious and Dicer-2 and mouse Dicer1 and Dgcr8 mutants. These findings indicate that there is interplay between the RNA silencing and snoRNA-mediated RNA processing systems, and that sdRNAs comprise a novel and ancient class of small RNAs in eukaryotes. PMID:19474147
Hydrodynamic Nambu brackets derived by geometric constraints
NASA Astrophysics Data System (ADS)
Blender, Richard; Badin, Gualtiero
2015-03-01
A geometric approach to derive the Nambu brackets for ideal two-dimensional (2D) hydrodynamics is suggested. The derivation is based on two-forms with vanishing integrals in a periodic domain, and with resulting dynamics constrained by an orthogonality condition. As a result, 2D hydrodynamics with vorticity as dynamic variable emerges as a generic model, with conservation laws which can be interpreted as enstrophy and energy functionals. Generalized forms like surface quasi-geostrophy and fractional Poisson equations for the stream-function are also included as results from the derivation. The formalism is extended to a hydrodynamic system coupled to a second degree of freedom, with the Rayleigh–Bénard convection as an example. This system is reformulated in terms of constitutive conservation laws with two additive brackets which represent individual processes: a first representing inviscid 2D hydrodynamics, and a second representing the coupling between hydrodynamics and thermodynamics. The results can be used for the formulation of conservative numerical algorithms that can be employed, for example, for the study of fronts and singularities.
Antithyroid effects of coal-derived pollutants
Lindsay, R.H.; Hill, J.B. ); Gaitan, E.; Cooksey, R.C. ); Jolley, R.L. )
1992-12-01
Endemic goiter in iodide-sufficient areas of the United States and Colombia has been linked to watersheds rich in coal and shale, which several reports suggest are the source of water-borne goitrogens. In this report the potential antithyroid activities of aqueous coal and shale extracts and of compounds identified in aqueous effluents from coal conversion processes were assayed in thyroid peroxidase (TPO) and thyroid slice systems. Aqueous extracts of coal and black shale were potent inhibitors of TPO or [sup 125]I organification by thyroid slices. The most abundant water-soluble compounds derived from coal are dihydroxyphenols, thiocyanate, disulfides, and hydroxypyridines. The dihydroxyphenols resorcinol, 2-methylresorcinol, and 5-methylresorcinol (orcinol) were 26.7, 22.5, and 7.2 times more potent, respectively, than the antithyroid drug 6-propylthiouracil (PTU). Other dihydroxyphenols and thiocyanate were less potent but comparable in activity to PTU. All dihydroxypridines and 3-hydroxypridine produced inhibitory effects comparable to PTU. None of the disulfides inhibited TPO. The antiperoxidase effects of combinations of two dihydroxyphenols or one dihydroxyphenol and SCN were additive, whereas the effects of a combination of four dihydroxyphenols at threshold inhibitory concentrations were synergistic. Thus, antithyroid effects may be greatly amplified by exposure to multiple coal-derived goitrogens and could be many times that produced by any one of the contributing pollutants. These results demonstrate that potent water-borne goitrogens are derived from coal and shale and that their contamination of water supplies could pose a serious threat of thyroid disorders.
Neutrophil-Derived Cytokines: Facts Beyond Expression
Tecchio, Cristina; Micheletti, Alessandra; Cassatella, Marco A.
2014-01-01
Polymorphonuclear neutrophils, besides their involvement in primary defense against infections – mainly through phagocytosis, generation of toxic molecules, release of enzymes, and formation of extracellular traps – are also becoming increasingly important for their contribution to the fine regulation in development of inflammatory and immune responses. These latter functions of neutrophils occur, in part, via their de novo production and release of a large variety of cytokines, including chemotactic cytokines (chemokines). Accordingly, the improvement in technologies for molecular and functional cell analysis, along with concomitant advances in cell purification techniques, have allowed the identification of a continuously growing list of neutrophil-derived cytokines, as well as the characterization of their biological implications in vitro and/or in vivo. This short review summarizes crucial concepts regarding the modalities of expression, release, and regulation of neutrophil-derived cytokines. It also highlights examples illustrating the potential implications of neutrophil-derived cytokines according to recent observations made in humans and/or in experimental animal models. PMID:25374568
Long-memory volatility in derivative hedging
NASA Astrophysics Data System (ADS)
Tan, Abby
2006-10-01
The aim of this work is to take into account the effects of long memory in volatility on derivative hedging. This idea is an extension of the work by Fedotov and Tan [Stochastic long memory process in option pricing, Int. J. Theor. Appl. Finance 8 (2005) 381-392] where they incorporate long-memory stochastic volatility in option pricing and derive pricing bands for option values. The starting point is the stochastic Black-Scholes hedging strategy which involves volatility with a long-range dependence. The stochastic hedging strategy is the sum of its deterministic term that is classical Black-Scholes hedging strategy with a constant volatility and a random deviation term which describes the risk arising from the random volatility. Using the fact that stock price and volatility fluctuate on different time scales, we derive an asymptotic equation for this deviation in terms of the Green's function and the fractional Brownian motion. The solution to this equation allows us to find hedging confidence intervals.
Derivation of naïve human embryonic stem cells
Ware, Carol B.; Nelson, Angelique M.; Mecham, Brigham; Hesson, Jennifer; Zhou, Wenyu; Jonlin, Erica C.; Jimenez-Caliani, Antonio J.; Deng, Xinxian; Cavanaugh, Christopher; Cook, Savannah; Tesar, Paul J.; Okada, Jeffrey; Margaretha, Lilyana; Sperber, Henrik; Choi, Michael; Blau, C. Anthony; Treuting, Piper M.; Hawkins, R. David; Cirulli, Vincenzo; Ruohola-Baker, Hannele
2014-01-01
The naïve pluripotent state has been shown in mice to lead to broad and more robust developmental potential relative to primed mouse epiblast cells. The human naïve ES cell state has eluded derivation without the use of transgenes, and forced expression of OCT4, KLF4, and KLF2 allows maintenance of human cells in a naïve state [Hanna J, et al. (2010) Proc Natl Acad Sci USA 107(20):9222–9227]. We describe two routes to generate nontransgenic naïve human ES cells (hESCs). The first is by reverse toggling of preexisting primed hESC lines by preculture in the histone deacetylase inhibitors butyrate and suberoylanilide hydroxamic acid, followed by culture in MEK/ERK and GSK3 inhibitors (2i) with FGF2. The second route is by direct derivation from a human embryo in 2i with FGF2. We show that human naïve cells meet mouse criteria for the naïve state by growth characteristics, antibody labeling profile, gene expression, X-inactivation profile, mitochondrial morphology, microRNA profile and development in the context of teratomas. hESCs can exist in a naïve state without the need for transgenes. Direct derivation is an elusive, but attainable, process, leading to cells at the earliest stage of in vitro pluripotency described for humans. Reverse toggling of primed cells to naïve is efficient and reproducible. PMID:24623855
Faisal, Saqib; Ullah, Farman; Maity, Pradip K; Rolfe, Alan; Samarakoon, Thiwanka B; Porubsky, Patrick; Neuenswander, Benjamin; Lushington, Gerald H; Basha, Fatima Z; Organ, Michael G; Hanson, Paul R
2012-04-01
A combination of MACOS scale-out and ROMP-derived oligomeric triazole phosphates (OTP(n)) have been successfully utilized for the preparation of a 106-member library of triazole containing benzothiaoxazepine-1,1-dioxides. This report demonstrates the utilization of a suite of soluble OTP(n) reagents for facile (triazolyl)methylation of 10 MACOS-derived sultam scaffolds in purification-free process for parallel synthesis of small molecule collections for HTS. PMID:22384820
Recollements of Derived Functor Categories and Zhaoyong Huang
Huang, Zhaoyong
Â781]. Then we provide a criterion for the existence of recollement of derived categories of functor categoriesRecollements of Derived Functor Categories Peng Yu and Zhaoyong HuangÂ§ Department of Mathematics the derived category of a locally finitely presented category and the derived category of contravariant
Transformation of spatial and perturbation derivatives of travel time
Cerveny, Vlastislav
Transformation of spatial and perturbation derivatives of travel time at a general interface We consider the partial derivatives of travel time with respect to both spatial coordinates and perturbation parameters. We derive the explicit equations for transforming these travelÂtime derivatives
Non-Derivable Item Set and Non-Derivable Literal Set Representations of Patterns Admitting Negation
NASA Astrophysics Data System (ADS)
Kryszkiewicz, Marzena
The discovery of frequent patterns has attracted a lot of attention of the data mining community. While an extensive research has been carried out for discovering positive patterns, little has been offered for discovering patterns with negation. The main hindrance to the progress of such research is huge amount of frequent patterns with negation, which exceeds the number of frequent positive patterns by orders of magnitude. In this paper, we examine properties of derivable and non-derivable patterns, including those with negated items. In particular, we establish important relationships among patterns admitting negation that have the same canonical variant. By analogy to frequent non-derivable itemsets, which constitute a concise lossless representation NDR of frequent positive patterns, we introduce frequent non-derivable literal sets lossless representation NDRL of frequent positive patterns admitting negation. Then we use the derived properties of literal sets to offer a concise representation NDIR of frequent patterns admitting negation that is built only from positive non-derivable itemsets. The relationships between the three representations are identified. The transformation of the new representations into not less concise lossless closure representations is discussed.
Biologic Rhythms Derived from Siberian Mammoths' Hairs
Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto
2011-01-01
Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ?31 cms/year and ?16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna. PMID:21747920
Antithyroid effects of coal-derived pollutants.
Lindsay, R H; Hill, J B; Gaitan, E; Cooksey, R C; Jolley, R L
1992-12-01
Endemic goiter in iodide-sufficient areas of the United States and Colombia has been linked to watersheds rich in coal and shale, which several reports suggest are the source of water-borne goitrogens. In this report the potential antithyroid activities of aqueous coal and shale extracts and of compounds identified in aqueous effluents from coal conversion processes were assayed in thyroid peroxidase (TPO) and thyroid slice systems. Aqueous extracts of coal and black shale were potent inhibitors of TPO or 125I organification by thyroid slices. The most abundant water-soluble compounds derived from coal are dihydroxy-phenols, thiocyanate, disulfides, and hydroxypyridines. The dihydroxyphenols resorcinol, 2-methylresorcinol, and 5-methylresorcinol (orcinol) were 26.7, 22.5, and 7.2 times more potent, respectively, than the antithyroid drug 6-propylthiouracil (PTU). Other dihydroxyphenols and thiocyanate were less potent but comparable in activity to PTU. All dihydroxypyridines and 3-hydroxypyridine produced inhibitory effects comparable to PTU. None of the disulfides inhibited TPO. The antiperoxidase effects of combinations of two dihydroxyphenols or one dihydroxyphenol and SCN were additive, whereas the effects of a combination of four dihydroxyphenols at threshold inhibitory concentrations were synergistic, resulting in net effects equivalent to or greater than the sum of the individual effects. Thus, antithyroid effects may be greatly amplified by exposure to multiple coal-derived goitrogens and could be many times that produced by any one of the contributing pollutants. These results demonstrate that potent water-borne goitrogens are derived from coal and shale and that their contamination of water supplies could pose a serious threat of thyroid disorders. PMID:1281508
Biologic Rhythms Derived from Siberian Mammoths Hairs
M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller
2011-12-31
Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.
Biologic rhythms derived from Siberian mammoths' hairs.
Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto
2011-01-01
Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ?31 cms/year and ?16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna. PMID:21747920
Triazolyl tryptoline derivatives as ?-secretase inhibitors
Jiaranaikulwanitch, Jutamas; Boonyarat, Chantana; Fokin, Valery V.; Vajragupta, Opa
2011-01-01
Tryptoline, a core structure of ochrolifuanine E, which is a hit compound from virtual screening of the Thai herbal database against BACE1 was used as a scaffold for the design of BACE1 inhibitors. The tryptoline was linked with different side chains by 1,2,3-triazole ring readily synthesized by catalytic azide-alkyne cycloaddition reactions. Twenty two triazolyl tryptoline derivatives were synthesized and screened for the inhibitory action against BACE1. JJCA-140 was the most potent inhibitor (IC50 = 1.49 ?M) and was 100 times more selective for BACE1 than for Cat-D. PMID:20943389
Time-derivative preconditioning for viscous flows
NASA Technical Reports Server (NTRS)
Choi, Yunho; Merkle, Charles L.
1991-01-01
A time-derivative preconditioning algorithm that is effective over a wide range of flow conditions from inviscid to very diffusive flows and from low speed to supersonic flows was developed. This algorithm uses a viscous set of primary dependent variables to introduce well-conditioned eigenvalues and to avoid having a nonphysical time reversal for viscous flow. The resulting algorithm also provides a mechanism for controlling the inviscid and viscous time step parameters to be of order one for very diffusive flows, thereby ensuring rapid convergence at very viscous flows as well as for inviscid flows. Convergence capabilities are demonstrated through computation of a wide variety of problems.
Black Holes in Higher-Derivative Gravity
Lu, H; Pope, C N; Stelle, K S
2015-01-01
Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this paper we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics.
Validation of an Experimentally Derived Uncertainty Model
NASA Technical Reports Server (NTRS)
Lim, K. B.; Cox, D. E.; Balas, G. J.; Juang, J.-N.
1996-01-01
The results show that uncertainty models can be obtained directly from system identification data by using a minimum norm model validation approach. The error between the test data and an analytical nominal model is modeled as a combination of unstructured additive and structured input multiplicative uncertainty. Robust controllers which use the experimentally derived uncertainty model show significant stability and performance improvements over controllers designed with assumed ad hoc uncertainty levels. Use of the identified uncertainty model also allowed a strong correlation between design predictions and experimental results.
Derivation of an Applied Nonlinear Schroedinger Equation.
Pitts, Todd Alan; Laine, Mark Richard; Schwarz, Jens; Rambo, Patrick K.; Karelitz, David B.
2015-01-01
We derive from first principles a mathematical physics model useful for understanding nonlinear optical propagation (including filamentation). All assumptions necessary for the development are clearly explained. We include the Kerr effect, Raman scattering, and ionization (as well as linear and nonlinear shock, diffraction and dispersion). We explain the phenomenological sub-models and each assumption required to arrive at a complete and consistent theoretical description. The development includes the relationship between shock and ionization and demonstrates why inclusion of Drude model impedance effects alters the nature of the shock operator. Unclassified Unlimited Release
Adipose derived stem cells and nerve regeneration
Faroni, Alessandro; Smith, Richard JP; Reid, Adam J
2014-01-01
Injuries to peripheral nerves are common and cause life-changing problems for patients alongside high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacrificing a section of nerve from elsewhere in the body to provide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacrifice of a functional nerve. Stem cells are prime candidates as accelerators of regeneration in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts. PMID:25221589
[Synthesis of potential CCK antagonist quinazolone derivatives].
Szabó, M; Kökösi, J; Orfi, L
1995-07-01
An original route has been found for the synthesis of [1,4]diazepino-quinazolones, a new ring system of heterocondensed quinazolones. These anthranilicacid-alanin-beta-alanin cyclopeptide derivatives constitute a structural moiety of asperlicin, the first natural cholecystokinin antagonist alkaloid. These compounds are therefore potential CCK antagonists. The new compounds were prepared via condensation of 2-amino-alkyl-quinazolones, obtained from 2-alkyl-quinazolones by side-chain substitution, with 1,3-bifunctional-reagents. We studied the cyclisation process under basic, acidic and phase-transfer catalyzed conditions. The structures of the synthesized compounds were characterized by IR, UV and NMR spectroscopy. PMID:7572196
Derivative Operators in Metric and Geometric Structures
V. V. Fernadez; A. M. Moya; W. A. Rodrigues Jr
2006-08-30
This paper (the seventh paper in a series of eight) continues the development of our theory of multivector and extensor calculus on smooth manifolds. Here we deal first with the concepts of ordinary Hodge coderivatives, duality identities, and Hodge coderivative identities. Then, we recall the concept of a Levi-Civita geometric structure and the concepts of Levi-Civita and gauge derivatives. New formulas that are important in the Lagrangian theory of multivector adn extensor fields are obtained. We introduce also he concept of covariant Hodge coderivative. We detail how all these concepts are related.
Black holes in higher derivative gravity.
Lü, H; Perkins, A; Pope, C N; Stelle, K S
2015-05-01
Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this Letter we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics. PMID:25978224
Amidinobenzisothiazole derivatives with antidegenerative activity on cartilage.
Panico, Annamaria; Vicini, Paola; Incerti, Matteo; Cardile, Venera; Gentile, Barbara; Ronsisvalle, Giuseppe
2002-08-01
N-(Benzo[d]isothiazol-3-yl)amidines were synthesised and evaluated for their antiinflammatory activity. Encouraging results led us to evaluate these derivatives on the prevention of cartilage destruction in articular disease. Antidegenerative activity was assayed on culture of porcine nasal cartilage and diarthroidal joint human cartilage in the presence of interleukin-1beta (IL-1beta). The amount of glycosaminoglycans (GAGs) and the production of nitric oxide (NO) in the culture medium were determined. The obtained results showed that all the compounds, in the presence of IL-beta, blocked the cartilage breakdown, with different behaviour. The antidegenerative activity is more evident in human cartilage. PMID:12361235
Black Holes in Higher-Derivative Gravity
H. Lu; A. Perkins; C. N. Pope; K. S. Stelle
2015-04-14
Extensions of Einstein gravity with higher-order derivative terms arise in string theory and other effective theories, as well as being of interest in their own right. In this paper we study static black-hole solutions in the example of Einstein gravity with additional quadratic curvature terms. A Lichnerowicz-type theorem simplifies the analysis by establishing that they must have vanishing Ricci scalar curvature. By numerical methods we then demonstrate the existence of further black-hole solutions over and above the Schwarzschild solution. We discuss some of their thermodynamic properties, and show that they obey the first law of thermodynamics.
Cationically polymerizable monomers derived from renewable sources
Crivello, J.V.
1992-10-01
The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.
New ligase-derived RNA polymerase ribozymes
LAWRENCE, MICHAEL S.; BARTEL, DAVID P.
2005-01-01
The search is underway for a catalytic RNA molecule capable of self-replication. Finding such a ribozyme would lend crucial support to the RNA World hypothesis, which holds that very early life-forms relied on RNA for both replicating and storing genetic information. We previously reported an RNA polymerase isolated from a pool of variants of an existing RNA ligase ribozyme. Here we report eight additional ligase-derived polymerase ribozymes isolated from this pool. Because each of them is a new potential starting point for further in vitro evolution and engineering, together they substantially enrich the set of candidates from which an RNA replicase ribozyme might eventually emerge. PMID:15987804
Exact cosmological solutions with nonminimal derivative coupling
Sushkov, Sergey V.
2009-11-15
We consider a gravitational theory of a scalar field {phi} with nonminimal derivative coupling to curvature. The coupling terms have the form {kappa}{sub 1}R{phi}{sub ,{mu}}{phi}{sup ,{mu}} and {kappa}{sub 2}R{sub {mu}}{sub {nu}}{phi}{sup ,{mu}}{phi}{sup ,{nu}}, where {kappa}{sub 1} and {kappa}{sub 2} are coupling parameters with dimensions of length squared. In general, field equations of the theory contain third derivatives of g{sub {mu}}{sub {nu}} and {phi}. However, in the case -2{kappa}{sub 1}={kappa}{sub 2}{identical_to}{kappa}, the derivative coupling term reads {kappa}G{sub {mu}}{sub {nu}}{phi}{sup ,{mu}}{phi}{sup ,{nu}} and the order of corresponding field equations is reduced up to second one. Assuming -2{kappa}{sub 1}={kappa}{sub 2}, we study the spatially-flat Friedman-Robertson-Walker model with a scale factor a(t) and find new exact cosmological solutions. It is shown that properties of the model at early stages crucially depend on the sign of {kappa}. For negative {kappa}, the model has an initial cosmological singularity, i.e., a(t){approx}(t-t{sub i}){sup 2/3} in the limit t{yields}t{sub i}; and for positive {kappa}, the Universe at early stages has the quasi-de Sitter behavior, i.e., a(t){approx}e{sup Ht} in the limit t{yields}-{infinity}, where H=(3{radical}({kappa})){sup -1}. The corresponding scalar field {phi} is exponentially growing at t{yields}-{infinity}, i.e., {phi}(t){approx}e{sup -t/{radical}}{sup ({kappa})}. At late stages, the Universe evolution does not depend on {kappa} at all; namely, for any {kappa} one has a(t){approx}t{sup 1/3} at t{yields}{infinity}. Summarizing, we conclude that a cosmological model with nonminimal derivative coupling of the form {kappa}G{sub {mu}}{sub {nu}}{phi}{sup ,{mu}}{phi}{sup ,{nu}} is able to explain in a unique manner both a quasi-de Sitter phase and an exit from it without any fine-tuned potential.
Formal Derivation of Concurrent Garbage Collectors
Pavlovic, Dusko; Smith, Douglas R
2010-01-01
Concurrent garbage collectors are notoriously difficult to implement correctly. Previous approaches to the issue of producing correct collectors have mainly been based on posit-and-prove verification or on the application of domain-specific templates and transformations. We show how to derive the upper reaches of a family of concurrent garbage collectors by refinement from a formal specification, emphasizing the application of domain-independent design theories and transformations. A key contribution is an extension to the classical lattice-theoretic fixpoint theorems to account for the dynamics of concurrent mutation and collection.
Pricing financial derivatives with neural networks
NASA Astrophysics Data System (ADS)
Morelli, Marco J.; Montagna, Guido; Nicrosini, Oreste; Treccani, Michele; Farina, Marco; Amato, Paolo
2004-07-01
Neural network algorithms are applied to the problem of option pricing and adopted to simulate the nonlinear behavior of such financial derivatives. Two different kinds of neural networks, i.e. multi-layer perceptrons and radial basis functions, are used and their performances compared in detail. The analysis is carried out both for standard European options and American ones, including evaluation of the Greek letters, necessary for hedging purposes. Detailed numerical investigation show that, after a careful phase of training, neural networks are able to predict the value of options and Greek letters with high accuracy and competitive computational time.
Biogenesis of endosome-derived transport carriers.
Chi, Richard J; Harrison, Megan S; Burd, Christopher G
2015-09-01
Sorting of macromolecules within the endosomal system is vital for physiological control of nutrient homeostasis, cell motility, and proteostasis. Trafficking routes that export macromolecules from the endosome via vesicle and tubule transport carriers constitute plasma membrane recycling and retrograde endosome-to-Golgi pathways. Proteins of the sorting nexin family have been discovered to function at nearly every step of endosomal transport carrier biogenesis and it is becoming increasingly clear that they form the core machineries of cargo-specific transport pathways that are closely integrated with cellular physiology. Here, we summarize recent progress in elucidating the pathways that mediate the biogenesis of endosome-derived transport carriers. PMID:26022064
Synthetic applications of hypophosphite derivatives in reduction.
Guyon, Carole; Métay, Estelle; Popowycz, Florence; Lemaire, Marc
2015-08-01
The development of new tools for the reduction of organic functions to reach high chemo- and stereo-selectivity is an important research domain. Although, aluminum and boron hydrides are commonly used, they suffer from environmentally and safety issues. In particular, at industrial scale, the search for more specific and efficient reagents with a lower ecological impact remains one of the main objectives of organic chemists. This review captures highlights from literature concerning phosphonic and phosphinic acid derivatives as reducing agents and evaluates their potential as alternatives, in particular to boron and aluminum hydrides. PMID:26083977
Geometric derivation of the chronometric redshift.
Segal, I E
1993-01-01
The chronometric redshift-distance relation z = tan 2(1/2rho), where rho is the distance in radians in the Einstein metric, is derived by an elementary geometric analysis comparable to that in traditional analysis of the expanding universe model. The differential dTt of Einstein time evolution Tt through time t, as applied to the local Minkowski coordinates x, takes the form sec2(1/2t). At the point of observation t = rho, implying that for a sufficiently localized source, observed wave lengths are a factor of sec2(1/2rho) greater than the corresponding emitted wave lengths. PMID:11607440
Gamma Ray Spectrum Unfolding Using Derivative Kernels
D. S. Vlachos; O. T. Kosmas
2009-05-04
The unfolding of a gamma ray spectrum experience many difficulties due to noise in the recorded data, that is based mainly on the change of photon energy due to scattering mechanisms (either in the detector or the medium), the accumulation of recorded counts in a fixed energy interval (the channel width of the detector) and finally the statistical fluctuation inside the detector. In order to deal with these problems, a new method is developed which interpolates the ideal spectrum with the use of special designed derivative kernels. Preliminary simulation results are presented and show that this approach is very effective even in spectra with low statistics.
Meshram, Jyotsna
2014-01-01
The present work deals with the synthesis and evaluation of biological activities of 4-aminoantipyrine derivatives derived from a three-component Betti reaction. The synthesis was initiated by the condensation of aromatic aldehyde, 4-aminoantipyrine, and 8-hydroxyquinoline in presence of fluorite as catalyst in a simple one-step protocol. The reactions were stirred at room temperature for 10–15?min achieving 92–95% yield. The structures of synthesized derivatives were established on the basis of spectroscopic and elemental analysis. All derivatives 4(a–h) were screened in vivo and in vitro for anti-inflammatory and anthelmintic activity against a reference drug, Diclofenac and Albendazole, respectively. The screening results show that compounds 4c, 4d, 4f, and 4h were found to possess potential anti-inflammatory activity while compounds 4a, 4b, 4e, and 4g are potent anthelmintic agents when compared with reference drugs, respectively. The bioactivity of these derivatives has also been evaluated with respect to Lipinski's rule of five using molinspiration cheminformatics software. PMID:24955256
Determination of benzotrifluoride derivative compounds in groundwater.
Lava, Roberto; Aimo, Emilia; Menegus, Luciana; Pojana, Giulio; Marcomini, Antonio
2013-12-01
Two simple analytical methods for the simultaneous determination and quantification of benzotrifluoride and eight chlorinated, amino and nitro benzotrifluoride derivatives in groundwater are proposed. Benzotrifluoride, 4-chlorobenzotrifluoride, 2,4-dichlorobenzotrifluoride and 3,4-dichlorobenzotrifluoride, were extracted by Purge-and-Trap on the basis of their volatile properties, while 3-aminobenzotrifluoride, 4-nitrobenzotrifluoride, 3-amino-4-chlorobenzotrifluoride, 3-nitro-4-chlorobenzotrifluoride and 4-chloro-3,5-dinitrobenzotrifluoride extractions were done with an automated SPE system. The analytical separations and detections were performed with two different GC systems, both equipped with single quadrupole mass spectrometer as detector. The LOD ranges for the two methods were 0.002-0.005 ?g L(-1) and 0.01-0.07 ?g L(-1), respectively. Both extraction methods were developed using spiked Milli-Q water and were then demonstrated with groundwater samples collected during autumn 2008. The areas of groundwater collection were polluted due to an episode of improper industrial soil disposal and consequent leakage of aliphatic and aromatic, fluorinated chemicals into the groundwater. This work eventually revealed the presence of several benzotrifluoride compounds most of them, like dichloro- and amino-derivatives, never been reported as environmental contaminants. PMID:24267073
N,N-dimethylcarbamyl derivatives of oxazepam.
Yang, S K; Lu, X L
1991-01-01
Three N,N-dimethylcarbamyl derivatives of oxazepam (1-(N,N-dimethylcarbamyl)oxazepam, 3-O-(N,N-dimethylcarbamyl)oxazepam, and 1,3-O-bis(N,N-dimethylcarbamyl) oxazepam) and a 3-O-acyl-1-(N,N-dimethylcarbamyl)-oxazepam were synthesized from either oxazepam or demoxepam. Enantiomeric pairs of these derivatives and of camazepam were resolved by high-performance liquid chromatography on at least two of three commercially available chiral stationary phase columns employed. Absolute configurations of resolved enantiomers were established by comparing their circular dichroism spectra to those of enantiomeric oxazepams with known absolute stereochemistry. Similar to those of oxazepam, enantiomers of 1-(N,N-dimethylcarbamyl)oxazepam undergo rapid racemization (t1/2 1.9 min at 23 degrees C and 0.9 min at 37 degrees C) in an aqueous solution at pH 7.5. The (R)-enantiomer of rac-3-O-acyl-1-(N,N-dimethylcarbamyl)oxazepam was hydrolyzed approximately 4.6-fold faster than the (S)-enantiomer by esterases in rat liver microsomes, whereas the (S)-enantiomer was hydrolyzed approximately 43-fold faster than the (R)-enantiomer by esterases in rat brain S9 fraction. PMID:1911050
Derivation and synthesis of renewable surfactants.
Foley, Patrick; Kermanshahi pour, Azadeh; Beach, Evan S; Zimmerman, Julie B
2012-02-21
This critical review focuses on the origins and preparation of bio-based surfactants, defined here as non-soap, amphiphilic molecules in which the carbon atoms are derived from annually renewable feedstocks. Environmental concerns and market pressures have led to greater relevance of these chemicals in commercial applications in recent years and extensive research has gone into exploring new classes of surfactants. Highlighted here are examples of bio-based surfactants that are produced on an industrial scale and/or are based on abundant starting materials. The trend of increasing use of renewable resources as starting materials for surfactants is introduced, followed by extensive discussion of the major classes of bio-derived hydrophobes and hydrophiles. Also discussed is the status of research and development with regard to biosynthetically produced surfactants. Finally, concluding remarks address the potential for new surfactant molecular structures as a result of ongoing development in the chemistry of biorefineries, i.e., that the transformation of lignocellulose into fuels is likely to support the manufacturing of new bio-based coproducts (238 references). PMID:22006024
Molecular structures of new ciprofloxacin derivatives
NASA Astrophysics Data System (ADS)
Tomiši?, Zrinka Bani?; Kujundži?, Nedjeljko; Kraja?i?, Mirjana Bukvi?; Višnjevac, Aleksandar; Koji?-Prodi?, Biserka
2002-06-01
Two new derivatives from the ciprofloxacin fluoroquinoline family, 7-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-quinoline-3-methylcarbamate and 1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-(3-oxopyrazolo)[4,3-c]quinoline, were synthesised, tested for antibacterial activity and crystallised. Their molecular and crystal structures were determined. Tests in vitro reveal lower activities than for ciprofloxacin. Characteristic structural features of these compounds are comparable to data for other known fluoroquinolines. The bicyclic quinoline ring is planar in both compounds; the carbamate side chain and five-membered pyrazolo ring are almost coplanar with it. A piperazinyl ring exhibits a chair conformation. In the crystal packing of the carbamate analogue, two C-H⋯O interactions form a dimer. The pyrazolo derivative crystallises as solvate with 1.5 water molecules per quinoline molecule. In its crystal structure donor and acceptor functionalities form dimers, via hydrogen bonds, which are connected into an infinite pattern through hydrogen bonded water molecules.
Hyperspectral derivatives analysis for intertidal habitat mapping
NASA Astrophysics Data System (ADS)
Oppelt, N.; Schulze, F.; Bartsch, I.
2012-09-01
Analysis of coastal marine algae communities enables an estimation of the state of coastal marine environments and provides evidence for environmental changes. Hyperspectral remote sensing provides a tool for mapping macroalgal habitats if the algal communities are spectrally resolvable. We tested the performance of a new approach for determining the distribution of macroalgae communities in the rocky intertidal zone of Helgoland (Germany) using airborne hyperspectral (AISAeagle) data. This new approach calculates the slopes in wavelength regions between specific pigment absorption features and does not rely on absolute reflectance values. The first order derivatives of these wavelength regions form slope bands, which are then classified using a k-Means approach. The new derivatives approach proved to be a time effective possibility for identifying the dominating macroalgae species with sufficient accuracy (Cohan's kappa = 0.70). The method was tested on another AISA data set and turned out to be as a robust (Cohan's kappa = 0.77) and easy-to-use approach for delineating dominant algae communities or habitats, which can be adapted easily to different data sets.
Jupiter's Rotation Period Derived From its Winds
NASA Astrophysics Data System (ADS)
Schubert, G.; Helled, R.; Anderson, J. D.
2008-12-01
Anderson and Schubert (2007, Science, 317, 1384) proposed that Saturn's rotation period might be ascertained by minimizing the dynamic heights of the 100 mbar isosurface with respect to the geoid; they derived a rotation period of 10h 32m 35s. We investigate the same approach for Jupiter to see if the Jovian rotation period is predicted by minimizing the dynamical heights of its isobaric (1 bar pressure level) surface. The shape of the Jovian pressure isosurface is derived from zonal wind data (García-Melendo and Sanchez-Lavega, 2001, Icarus, 316) and the Jovian geoid. Then, by regarding the Jovian geoid as undetermined in terms of Jupiter's rotation rate, we vary the rotation rate and the geoid and search for the geoid that minimizes the dynamical heights of the pressure isosurface in an rms sense. A rotation period of 9h 54m 29.7s is found to minimize the dynamical heights of the pressure isosurface. This rotation period is only one minute shorter than the measured period of Jupiter. The successful application of the method to Jupiter lends support to its relevance for Saturn. Application of the approach to Neptune and Uranus will also be discussed.
Spatiotemporal hemodynamic response functions derived from physiology.
Aquino, K M; Robinson, P A; Drysdale, P M
2014-04-21
Probing neural activity with functional magnetic resonance imaging (fMRI) relies upon understanding the hemodynamic response to changes in neural activity. Although existing studies have extensively characterized the temporal hemodynamic response, less is understood about the spatial and spatiotemporal hemodynamic responses. This study systematically characterizes the spatiotemporal response by deriving the hemodynamic response due to a short localized neural drive, i.e., the spatiotemporal hemodynamic response function (stHRF) from a physiological model of hemodynamics based on a poroelastic model of cortical tissue. In this study, the model's boundary conditions are clarified and a resulting nonlinear hemodynamic wave equation is derived. From this wave equation, damped linear hemodynamic waves are predicted from the stHRF. The main features of these waves depend on two physiological parameters: wave propagation speed, which depends on mean cortical stiffness, and damping which depends on effective viscosity. Some of these predictions were applied and validated in a companion study (Aquino et al., 2012). The advantages of having such a theory for the stHRF include improving the interpretation of spatiotemporal dynamics in fMRI data; improving estimates of neural activity with fMRI spatiotemporal deconvolution; and enabling wave interactions between hemodynamic waves to be predicted and exploited to improve the signal to noise ratio of fMRI. PMID:24398024
Fluoroalkane thioheterocyclic derivatives and their antitumor activity.
Li, Guangxiao; Sun, Qian; Wang, Dongling; Xu, Ying; Zhuang, Jingjing; Zhang, Qian; Sun, Dequn
2015-03-26
Two series of novel trifluorobutenyl derivatives of heterocyclic with convenient and efficient synthesis methods and their antitumor activity on three cell lines have been reported for the first time. The derivatives were synthesized by the nucleophilic substitution between 4-bromo-1,1,2-trifluorobutene-1-ene and commercially available nitrogen-containing heterocycles with sulfydryl or monosubstituted malononitrile. The twenty-four new compounds were characterized by (1)HNMR, (13)CNMR and HR-MS. Totally, thirty-seven compounds were evaluated for the antitumor activity on three cancer cell lines (SH-SY5Y, MCF-7 and HepG2) using conventional MTT assay. The pharmacological results indicated that the compounds 3c, 3h, 4c, 8, 9, 10 and 11 showed potent to moderate antitumor activity against three cancer cell lines, with IC50 values ranging between 0.4 ?M and 41.5 ?M. Even though they had less active than the reference compound taxol against MCF-7 and HepG2 lines, but they were better than the reference compound noscapine against SH-SY5Y cells, especially the compound 3h with a IC50 value of 0.4 ?M. PMID:25728023
Active acoustic metamaterial with fractional derivative controller
NASA Astrophysics Data System (ADS)
Althamer, S.; Baz, A.
2014-03-01
A class of active acoustic metamaterial (AAM) is presented. The proposed AAM consists of an acoustic transmission line connected in parallel to an array of Helmholtz resonators that are provided with actively controlled boundaries. In this manner, the AAM is in effect an assembly of periodic cells, each of which consists of a Helmholtz resonator connected in parallel to two sections of the transmission line. The two sections meet the Helmholtz resonator at its neck. The local control action at each Helmholtz resonator of a unit cell is generated by using a Fractional Derivative (FD) controller that relies in its operation on the measurement of the flow resulting from the deflection of the resonator boundary and the flow rates inside the two transmission line sections before and after the resonator. Such a single local control action is shown to be capable of controlling the local effective density and elasticity of each unit cell. A lumped-parameter model is developed to model the dynamics and control characteristics of the AAM under different gains and exponents of the FD controller. The model is exercised to demonstrate the ability of the FD controller in generating metamaterials with double negative effective density and elasticity over broad frequency ranges as compared to conventional Proportional and Derivative (PD) controllers. With such capabilities, the development of AAM with FD control action may provide viable means for generating desirable spatial distributions of density and elasticity over broad frequency band using a small number of control actuators.
The relativistic Sagnac Effect: two derivations
Rizzi, G; Ruggiero, Matteo Luca
2003-01-01
The phase shift due to the Sagnac Effect, for relativistic matter and electromagnetic beams, counter-propagating in a rotating interferometer, is deduced using two different approaches. From one hand, we show that the relativistic law of velocity addition leads to the well known Sagnac time difference, which is the same independently of the nature of the interfering beams, evidencing in this way the universality of the effect. Another derivation is based on a formal analogy with the phase shift, induced by the magnetic potential, for charged particles travelling in a region where a constant vector potential is present: this is the so called Aharonov-Bohm effect. Both derivations, are carried out in a fully relativistic context, using a suitable 1+3 splitting that allows us to recognize and define the space where electromagnetic and matter waves propagate: this is an extended 3-space, which we call the "relative space". It is recognized as the only space having an actual physical meaning from an operational po...
The relativistic Sagnac Effect: two derivations
Guido Rizzi; Matteo Luca Ruggiero
2003-09-26
The phase shift due to the Sagnac Effect, for relativistic matter and electromagnetic beams, counter-propagating in a rotating interferometer, is deduced using two different approaches. From one hand, we show that the relativistic law of velocity addition leads to the well known Sagnac time difference, which is the same independently of the physical nature of the interfering beams, evidencing in this way the universality of the effect. Another derivation is based on a formal analogy with the phase shift induced by the magnetic potential for charged particles travelling in a region where a constant vector potential is present: this is the so called Aharonov-Bohm effect. Both derivations are carried out in a fully relativistic context, using a suitable 1+3 splitting that allows us to recognize and define the space where electromagnetic and matter waves propagate: this is an extended 3-space, which we call "relative space". It is recognized as the only space having an actual physical meaning from an operational point of view, and it is identified as the 'physical space of the rotating platform': the geometry of this space turns out to be non Euclidean, according to Einstein's early intuition.
Anionic derivatives of uracil: fragmentation and reactivity.
Cole, Callie A; Wang, Zhe-Chen; Snow, Theodore P; Bierbaum, Veronica M
2014-09-01
Uracil is an essential biomolecule for terrestrial life, yet its prebiotic formation mechanisms have proven elusive for decades. Meteorites have been shown to contain uracil and the interstellar abundance of aromatic species and nitrogen-containing molecules is well established, providing support for uracil's presence in the interstellar medium (ISM). The ion chemistry of uracil may provide clues to its prebiotic synthesis and role in the origin of life. The fragmentation of biomolecules provides valuable insights into their formation. Previous research focused primarily on the fragmentation and reactivity of cations derived from uracil. In this study, we explore deprotonated uracil-5-carboxylic acid and its anionic fragments to elucidate novel reagents of uracil formation and to characterize the reactivity of uracil's anionic derivatives. The structures of these fragments are identified through theoretical calculations, further fragmentation, experimental acidity bracketing, and reactivity with several detected and potential interstellar species (SO2, OCS, CS2, NO, N2O, CO, NH3, O2, and C2H4). Fragmentation is achieved through collision induced dissociation (CID) in a commercial ion trap mass spectrometer, and all reaction rate constants are measured using a modification of this instrument. Experimental data are supported by theoretical calculations at the B3LYP/6-311++G(d,p) level of theory. Lastly, the astrochemical implications of the observed fragmentation and reaction processes are discussed. PMID:25036757
Thermal electron heating rate: A derivation
NASA Technical Reports Server (NTRS)
Hoegy, W. R.
1983-01-01
The thermal electron heating rate is an important heat source term in the ionospheric electron energy balance equation, representing heating by photoelectrons or by precipitating higher energy electrons. A formula for the thermal electron heating rate is derived from the kinetic equation using the electron-electron collision operator as given by the unified theory of Kihara and Aono. This collision operator includes collective interactions to produce a finite collision operator with an exact Coulomb logarithm term. The derived heating rate O(e) is the sum of three terms, O(e) = O(p) + S + O(int), which are respectively: (1) primary electron production term giving the heating from newly created electrons that have not yet suffered collisions with the ambient electrons; (2) a heating term evaluated on the energy surface m(e)/2 = E(T) at the transition between Maxwellian and tail electrons at E(T); and (3) the integral term representing heating of Maxwellian electrons by energetic tail electrons at energies ET. Published ionospheric electron temperature studies used only the integral term O(int) with differing lower integration limits. Use of the incomplete heating rate could lead to erroneous conclusions regarding electron heat balance, since O(e) is greater than O(int) by as much as a factor of two.
Biodegradation of hyaluronic acid derivatives by hyaluronidase.
Zhong, S P; Campoccia, D; Doherty, P J; Williams, R L; Benedetti, L; Williams, D F
1994-04-01
Hyaluronic acid (salt) (HA) has been chemically modified as a biomaterial for medical applications such as controlled drug release matrices, nerve guides and wound dressings. A series of HA derivatives, which include different ester types and different degrees of esterification, have been used to investigate the stability of these materials in testicular hyaluronidase. Gel permeation chromatography and capillary viscometer have been employed to determine the size of the molecules, the former used for the water insoluble derivatives that dissolve in dimethyl sulphoxide, the latter for the water soluble samples. The preliminary experimental results indicated that the molecular weight of fully esterified hyaluronic acid (both ethyl and benzyl esters) did not decrease after treatment in the enzyme for 7 and 14 days while the water soluble partially esterified HA were degraded by the enzyme producing a sharp reduction of viscosity within minutes. These observations tend to suggest that the carboxylic groups in the beta-glucoronic acid unit are the activation centre of this enzyme and the total blockage of these groups can restrict the cleavage of beta (1-->4) glycoside bonds by this enzyme. PMID:8061127
Renewable polyethylene mimics derived from castor oil.
Türünç, O?uz; Montero de Espinosa, Lucas; Meier, Michael A R
2011-09-01
An increasing number of reports on the syntheses of carbohydrate- and plant oil-based polymers has been published in ongoing efforts to produce plastic materials from renewable resources. Although many of these polymers are biodegradable and this is a desirable property for certain applications, in some cases non-degradable polymers are needed for long-term use purposes. Polyolefins are one of the most important classes of materials that have already taken their places in our daily life. On the other hand, their production relies on fossil resources. Therefore, within this contribution, we discuss synthetic routes toward a number of polyethylene mimics derived from fatty acids via thiol-ene and ADMET polymerization reactions in order to establish more sustainable routes toward this important class of polymers. Two different diene monomers were thus prepared from castor oil derived platform chemicals, their polymerization via the two mentioned routes was optimized and compared to each other, and their thermal properties were investigated. PMID:21710532
Feature Detection in Linked Derived Spaces
NASA Technical Reports Server (NTRS)
Henze, Chris; Gearld-Yamasaki, Michael (Technical Monitor)
1998-01-01
This paper describes by example a strategy for plotting and interacting with data in multiple metric spaces. The example system was designed for use with time-varying computational fluid dynamics (CFD) datasets, but the methodology is directly applicable to other types of field data. The central objects embodied by the tool are {\\em portraits}, which show the data in various coordinate systems, while preserving their spatial connectivity and temporal variability. The coordinates are derived in various ways from the field data, and an important feature is that new and derived portraits can be created interactively. The primary operations supported by the tool are brushing and linking: the user can select a subset of a given portrait, and this subset is highlighted in all portraits. The user can combine highlighted subsets from an arbitrary number of portraits with the usual logical operators, thereby indicating where an arbitrarily complex set of conditions holds. The system is useful for exploratory visualization and feature detection in multivariate data.
[Antioxidant activity of hydroxy derivatives of coumarin].
Potapovich, M V; Metelitsa, D I; Shadyro, O I
2012-01-01
The inhibition efficiency (antioxidant activity) of hydroxy derivatives of coumarin, such as esculetin, dicumarol, and fraxetin, was studied in the methemalbumin-H2O2-tetramethylbenzidine (TMB) pseudoperoxidase system at 20 degrees C in a buffered physiological solution (pH 7.4) containing 6% DMF and 0.25% DMSO. The inhibitor's efficiency was quantitatively characterized by the inhibition constants (K(i), microM) and the inhibition degree (%). The K(i) values for esculetin, dicumarol, and fraxetin were 9.5, 15, and 26 microM, respectively. Esculetin and fraxetin inhibited pseudoperoxidase oxidation of TMB in a noncompetitive manner; dicumarol, in a mixed manner. The inhibiting activity ofesculetin in peroxidase-catalyzed TMB oxidation at pH 6.4 is characterized by a K(i) value equal to 1.15 microM, and the inhibition process is competitive. Esculetin was found to be the most effective antioxidant of plant origin among all derivatives previously studied in model biochemical systems. PMID:22834298
Primer on electricity futures and other derivatives
Stoft, S.; Belden, T.; Goldman, C.; Pickle, S.
1998-01-01
Increased competition in bulk power and retail electricity markets is likely to lower electricity prices, but will also result in greater price volatility as the industry moves away from administratively determined, cost-based rates and encourages market-driven prices. Price volatility introduces new risks for generators, consumers, and marketers. Electricity futures and other derivatives can help each of these market participants manage, or hedge, price risks in a competitive electricity market. Futures contracts are legally binding and negotiable contracts that call for the future delivery of a commodity. In most cases, physical delivery does not take place, and the futures contract is closed by buying or selling a futures contract on or near the delivery date. Other electric rate derivatives include options, price swaps, basis swaps, and forward contracts. This report is intended as a primer for public utility commissioners and their staff on futures and other financial instruments used to manage price risks. The report also explores some of the difficult choices facing regulators as they attempt to develop policies in this area.
3-Nitroasterric Acid Derivatives from an Antarctic Sponge-Derived Pseudogymnoascus sp. Fungus.
Figueroa, Luis; Jiménez, Carlos; Rodríguez, Jaime; Areche, Carlos; Chávez, Renato; Henríquez, Marlene; de la Cruz, Mercedes; Díaz, Caridad; Segade, Yuri; Vaca, Inmaculada
2015-04-24
Four new nitroasterric acid derivatives, pseudogymnoascins A-C (1-3) and 3-nitroasterric acid (4), along with the two known compounds questin and pyriculamide, were obtained from the cultures of a Pseudogymnoascus sp. fungus isolated from an Antarctic marine sponge belonging to the genus Hymeniacidon. The structures of the new compounds were determined by extensive NMR and MS analyses. These compounds are the first nitro derivatives of the known fungal metabolite asterric acid. Several asterric acid derivatives isolated from other fungal strains have shown antibacterial and antifungal activities. However, the new compounds described in this work were inactive against a panel of bacteria and fungi (MIC > 64 ?g/mL). PMID:25732560
Li, Chun-Shun; Li, Xiao-Ming; Gao, Shu-Shan; Lu, Yan-Hua; Wang, Bin-Gui
2013-01-01
Five new anthranilic acid derivatives, penipacids A–E (1–5), together with one known analogue (6), which was previously synthesized, were characterized from the ethyl acetate extract of the marine sediment-derived fungus Penicillium paneum SD-44. Their structures were elucidated mainly by extensive NMR spectroscopic and mass spectrometric analysis. The cytotoxicity and antimicrobial activity of the isolated compounds were evaluated. Compounds 1, and 5 exhibited inhibitory activity against human colon cancer RKO cell line, while compound 6 displayed cytotoxic activity against Hela cell line. PMID:23966037
Thiasporines A-C, thiazine and thiazole derivatives from a marine-derived Actinomycetospora chlora.
Fu, Peng; MacMillan, John B
2015-03-27
Thiasporine A (1), the first natural product with a 5-hydroxy-4H-1,3-thiazin-4-one moiety, along with two new thiazole derivatives, thiasporines B and C (2 and 3), were isolated from the marine-derived Actinomycetospora chlora SNC-032. The structures of 1-3 were established on the basis of comprehensive spectroscopic analysis and chemical methods. Thiasporine A showed cytotoxicity against the non-small-cell lung cancer cell line H2122 with an IC50 value of 5.4 ?M. PMID:25584783
Osteogenesis of Adipose-Derived Stem Cells
Grottkau, Brian E.; Lin, Yunfeng
2013-01-01
Current treatment options for skeletal repair, including immobilization, rigid fixation, alloplastic materials and bone grafts, have significant limitations. Bone tissue engineering offers a promising method for the repair of bone deficieny caused by fractures, bone loss and tumors. The use of adipose derived stem cells (ASCs) has received attention because of the self-renewal ability, high proliferative capacity and potential of osteogenic differentiation in vitro and in vivo studies of bone regeneration. Although cell therapies using ASCs are widely promising in various clinical fields, no large human clinical trials exist for bone tissue engineering. The aim of this review is to introduce how they are harvested, examine the characterization of ASCs, to review the mechanisms of osteogenic differentiation, to analyze the effect of mechanical and chemical stimuli on ASC osteodifferentiation, to summarize the current knowledge about usage of ASC in vivo studies and clinical trials, and finally to conclude with a general summary of the field and comments on its future direction.
Uncertainties in derived temperature-height profiles
NASA Technical Reports Server (NTRS)
Minzner, R. A.
1974-01-01
Nomographs were developed for relating uncertainty in temperature T to uncertainty in the observed height profiles of both pressure p and density rho. The relative uncertainty delta T/T is seen to depend not only upon the relative uncertainties delta P/P or delta rho/rho, and to a small extent upon the value of T or H, but primarily upon the sampling-height increment Delta h, the height increment between successive observations of p or delta. For a fixed value of delta p/p, the value of delta T/T varies inversely with Delta h. No limit exists in the fineness of usable height resolution of T which may be derived from densities, while a fine height resolution in pressure-height data leads to temperatures with unacceptably large uncertainties.
Synthesis and cytotoxic properties of tryptamine derivatives.
Salikov, Rinat F; Belyy, Aleksandr Yu; Khusnutdinova, Nailya S; Vakhitova, Yulia V; Tomilov, Yury V
2015-09-01
The cyclopropyliminium and subsequent Grandberg rearrangements of cyclopropylketone hydrozones lead to the formation of tryptamines, which were additionally substituted at either the aromatic ring atoms or the amino group. The products were tested for their cytotoxic properties against HepG2, Jurkat and HEK293 cell lines using MTT assay. The highest activity as well as the highest selectivity was found amongst the compounds derived with one benzyl substituent at the amino group. The flow cytometry technique revealed cell-type specificity in terms of the mechanism of viability inhibition. Thus, the compounds were found to induce mainly apoptosis in HEK293 and HepG2 cells, while Jurkat cells displayed late apoptotic and necrotic responses. The apoptosis pathway is most likely to include mitochondrial damage. PMID:26174553
Fluorescein Derivatives in Intravital Fluorescence Imaging
Robertson, Thomas A.; Bunel, Florestan; Roberts, Michael S.
2013-01-01
Intravital fluorescence microscopy enables the direct imaging of fluorophores in vivo and advanced techniques such as fluorescence lifetime imaging (FLIM) enable the simultaneous detection of multiple fluorophores. Consequently, it is now possible to record distribution and metabolism of a chemical in vivo and to optimise the delivery of fluorophores in vivo. Recent clinical applications with fluorescein and other intravital fluorescent stains have occurred in neurosurgery, dermatology [including photodynamic therapy (PDT)] and endomicroscopy. Potential uses have been identified in periodontal disease, skin graft and cancer surgery. Animal studies have demonstrated that diseased tissue can be specifically stained with fluorophore conjugates. This review focuses on the fluorescein derived fluorophores in common clinical use and provides examples of novel applications from studies in tissue samples. PMID:24709799
Synthesis and antifungal activity of chalcone derivatives.
Zheng, Yuanyuan; Wang, Xuesong; Gao, Sumei; Ma, Min; Ren, Guiming; Liu, Huabing; Chen, Xiaohong
2015-10-01
In the present study, using chalcone as a lead compound, a series of its derivatives (compounds 1-30) were designed and synthesised. Their activity of anti-pathogenic fungi of plants has been evaluated. It is found that these compounds have good antifungal activity against Sclerotinia sclerotiorum, Helminthosprium maydis, Botrytis cinerea, Rhizoctonia solani and Gibberella zeae. Among them, the inhibition of growth for compound 30 against S. sclerotiorum showed 89.9%, with the median effective concentrations (EC50) of 15.4 ?g mL(- 1). The inhibition of growth for compounds 28, 29 and 30 at a concentration of 100 ?g mL(- 1) against H. maydis is 90.3%, 90.7% and 91.1%, with EC50 of 15.1, 18.3 and 18.1?g mL(- 1), respectively. PMID:25675372
Twelve benzene derivatives from Clausena excavata.
Peng, Wen-Wen; Song, Wei-Wu; Huang, Mao-Bo; Zeng, Guang-Zhi; Tan, Ning-Hua
2014-12-01
A new phenethanol, (2'R)-4-(2', 3'-dihydroxy-3'-methyl-butanoxy)-phenethanol (1), along with other eleven known benzene derivatives (2-12) were isolated from the roots, stems and leaves of Clausena excavata (Rutaceae). Compounds 3 and 4 are new natural products, and compounds 5-8, 10-12 were isolated from C. excavata for the first time. Their structures were elucidated on the basis of MS, 1D and 2D NMR spectroscopic analyses including HSQC, COSY and HMBC experiments. 1 was tested for its cytotoxicities against A549, HeLa and BGC-823 cancer cell lines, and antimicrobial activities against Candida albicans and Staphylococcus aureus. The results showed that 1 did not exhibit cytotoxic and antimicrobial activities. PMID:25920198
Satellite derived cirrus particle size - Tropical clouds
NASA Technical Reports Server (NTRS)
Wielicki, Bruce A.; Suttles, John T.; Parker, Lindsay; Arduini, Robert F.
1990-01-01
The present study extends the earlier work of Wielicki et al. (1990) to examine several cases of tropical cirrus clouds. Particle effective radius is estimated and compared to other studies of cirrus clouds. Particle size and phase are estimated by comparing reflectance observations by the Landsat satellite with theoretical calculations for a range of possible water and ice particle sizes. An examination of effective particle radius for six cases of tropical cirrus clouds over the eastern Pacific Ocean found typical radii of 60 microns. This value is similar to that derived for a case of midlatitude cirrus during the FIRE experiment in October 1986. Particle size is found to increase with decreasing cloud optical depth.
Overview of medically important antifungal azole derivatives.
Fromtling, R A
1988-01-01
Fungal infections are a major burden to the health and welfare of modern humans. They range from simply cosmetic, non-life-threatening skin infections to severe, systemic infections that may lead to significant debilitation or death. The selection of chemotherapeutic agents useful for the treatment of fungal infections is small. In this overview, a major chemical group with antifungal activity, the azole derivatives, is examined. Included are historical and state of the art information on the in vitro activity, experimental in vivo activity, mode of action, pharmacokinetics, clinical studies, and uses and adverse reactions of imidazoles currently marketed (clotrimazole, miconazole, econazole, ketoconazole, bifonazole, butoconazole, croconazole, fenticonazole, isoconazole, oxiconazole, sulconazole, and tioconazole) and under development (aliconazole and omoconazole), as well as triazoles currently marketed (terconazole) and under development (fluconazole, itraconazole, vibunazole, alteconazole, and ICI 195,739). PMID:3069196
Platelet-Derived Serotonin Mediates Liver Regeneration
NASA Astrophysics Data System (ADS)
Lesurtel, Mickael; Graf, Rolf; Aleil, Boris; Walther, Diego J.; Tian, Yinghua; Jochum, Wolfram; Gachet, Christian; Bader, Michael; Clavien, Pierre-Alain
2006-04-01
The liver can regenerate its volume after major tissue loss. In a mouse model of liver regeneration, thrombocytopenia, or impaired platelet activity resulted in the failure to initiate cellular proliferation in the liver. Platelets are major carriers of serotonin in the blood. In thrombocytopenic mice, a serotonin agonist reconstituted liver proliferation. The expression of 5-HT2A and 2B subtype serotonin receptors in the liver increased after hepatectomy. Antagonists of 5-HT2A and 2B receptors inhibited liver regeneration. Liver regeneration was also blunted in mice lacking tryptophan hydroxylase 1, which is the rate-limiting enzyme for the synthesis of peripheral serotonin. This failure of regeneration was rescued by reloading serotonin-free platelets with a serotonin precursor molecule. These results suggest that platelet-derived serotonin is involved in the initiation of liver regeneration.
Quinol derivatives as potential trypanocidal agents.
Capes, Amy; Patterson, Stephen; Wyllie, Susan; Hallyburton, Irene; Collie, Iain T; McCarroll, Andrew J; Stevens, Malcolm F G; Frearson, Julie A; Wyatt, Paul G; Fairlamb, Alan H; Gilbert, Ian H
2012-02-15
Quinols have been developed as a class of potential anti-cancer compounds. They are thought to act as double Michael acceptors, forming two covalent bonds to their target protein(s). Quinols have also been shown to have activity against the parasite Trypanosoma brucei, the causative organism of human African trypanosomiasis, but they demonstrated little selectivity over mammalian MRC5 cells in a counter-screen. In this paper, we report screening of further examples of quinols against T. brucei. We were able to derive an SAR, but the compounds demonstrated little selectivity over MRC5 cells. In an approach to increase selectivity, we attached melamine and benzamidine motifs to the quinols, because these moieties are known to be selectively concentrated in the parasite by transporter proteins. In general these transporter motif-containing analogues showed increased selectivity; however they also showed reduced levels of potency against T. brucei. PMID:22264753
Anticonvulsant activity of four oxygenated cannabidiol derivatives.
Carlini, E A; Mechoulam, R; Lander, N
1975-09-01
A pharmacological comparison between cannabidiol (CBD) and four CBD derivatives, namely CBD-aldehyde-diacetate (I), 6-oxo-CBD-diacetate (II), 6-hydroxy-CBD-tri-acetate (III), and 9-hydroxy-CBD-triacetate (IV) was carried out in mice. Protection against maximal electroshock convulsions, potentiation of pentobarbital sleeping-time and reduction of spontaneous motor activity were the effects measured. All 5 compounds were equally potent in potentiating barbiturate sleeping time at doses ranging from 6.25 to 100 mg/kg. At 12.5 and 25 mg/kg only CBD and IV were able to decrease significantly the spontaneous motor activity. CBD, II, III and IV were also active in protecting mice against electroconvulsive shock at doses of 100-200 mg/kg, although at the larger dose CBD and compound II were the most efficient. Compound I was toxic, killing about half of the animals within 24 h after injection. PMID:1188178
Functionalized carbon nanomaterials derived from carbohydrates.
Jagadeesan, Dinesh; Eswaramoorthy, Muthusamy
2010-02-01
A tremendous growth in the field of carbon nanomaterials has led to the emergence of carbon nanotubes, fullerenes, mesoporous carbon and more recently graphene. Some of these materials have found applications in electronics, sensors, catalysis, drug delivery, composites, and so forth. The high temperatures and hydrocarbon precursors involved in their synthesis usually yield highly inert graphitic surfaces. As some of the applications require functionalization of their inert graphitic surface with groups like -COOH, -OH, and -NH(2), treatment of these materials in oxidizing agents and concentrated acids become inevitable. More recent works have involved using precursors like carbohydrates to produce carbon nanostructures rich in functional groups in a single-step under hydrothermal conditions. These carbon nanostructures have already found many applications in composites, drug delivery, materials synthesis, and Li ion batteries. The review aims to highlight some of the recent developments in the application of carbohydrate derived carbon nanostructures and also provide an outlook of their future prospects. PMID:20029888
Quinol derivatives as potential trypanocidal agents
Capes, Amy; Patterson, Stephen; Wyllie, Susan; Hallyburton, Irene; Collie, Iain T.; McCarroll, Andrew J.; Stevens, Malcolm F.G.; Frearson, Julie A.; Wyatt, Paul G.; Fairlamb, Alan H.; Gilbert, Ian H.
2012-01-01
Quinols have been developed as a class of potential anti-cancer compounds. They are thought to act as double Michael acceptors, forming two covalent bonds to their target protein(s). Quinols have also been shown to have activity against the parasite Trypanosoma brucei, the causative organism of human African trypanosomiasis, but they demonstrated little selectivity over mammalian MRC5 cells in a counter-screen. In this paper, we report screening of further examples of quinols against T. brucei. We were able to derive an SAR, but the compounds demonstrated little selectivity over MRC5 cells. In an approach to increase selectivity, we attached melamine and benzamidine motifs to the quinols, because these moieties are known to be selectively concentrated in the parasite by transporter proteins. In general these transporter motif-containing analogues showed increased selectivity; however they also showed reduced levels of potency against T. brucei. PMID:22264753
Non-Covalent Derivatives: Cocrystals and Eutectics.
Stoler, Emily; Warner, John C
2015-01-01
Non-covalent derivatives (NCDs) are formed by incorporating one (or more) coformer molecule(s) into the matrix of a parent molecule via non-covalent forces. These forces can include ionic forces, Van der Waals forces, hydrogen bonding, lipophilic-lipophilic interactions and pi-pi interactions. NCDs, in both cocrystal and eutectic forms, possess properties that are unique to their supramolecular matrix. These properties include critical product performance factors such as solubility, stability and bioavailability. NCDs have been used to tailor materials for a variety of applications and have the potential to be used in an even broader range of materials and processes. NCDs can be prepared using little or no solvent and none of the reagents typical to synthetic modifications. Thus, NCDs represent a powerfully versatile, environmentally-friendly and cost-effective opportunity. PMID:26287141
Towards Tartaric-Acid-Derived Asymmetric Organocatalysts
Gratzer, Katharina; Gururaja, Guddeangadi N; Waser, Mario
2013-01-01
Tartaric acid is one of the most prominent naturally occurring chiral compounds. Whereas its application in the production of chiral ligands for metal-catalysed reactions has been exhaustively investigated, its potential to provide new organocatalysts has been less extensively explored. Nevertheless, some impressive results, such as the use of TADDOLs as chiral H-bonding catalysts or of tartrate-derived asymmetric quaternary ammonium salt catalysts, have been reported over the last decade. The goal of this article is to provide a representative overview of the potential and the limitations of tartaric acid or TADDOLs in the creation of new organocatalysts and to highlight some of the most spectacular applications of these catalysts, as well as to summarize case studies in which other classes of chiral backbones were better suited. PMID:24194674
Chaotic inflation in higher derivative gravity theories
Shynaray Myrzakul; Ratbay Myrzakulov; Lorenzo Sebastiani
2015-02-25
In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar $R^2$, the contraction of the Ricci tensor $P$, and the contraction of the Riemann tensor $Q$. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the $e$-folds number, and the spectral indexes. Several explicit examples are furnished, namely we will consider the cases of massive scalar field and scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. Viable inflation according with observations is analyzed.
Scrap tire derived fuel: Markets and issues
Serumgard, J. [Scrap Tire Management Council, Washington, DC (United States)
1997-12-01
More than 250 million scrap tires are generated annually in the United States and their proper management continues to be a solid waste management concern. Sound markets for scrap tires are growing and are consuming an ever increasing percentage of annual generation, with market capacity reaching more than 75% of annual generation in 1996. Of the three major markets - fuel, civil engineering applications, and ground rubber markets - the use of tires as a fuel is by far the largest market. The major fuel users include cement kilns, pulp and paper mills, electrical generation facilities, and some industrial facilities. Current issues that may impact the tire fuel market include continued public concern over the use of tires as fuels, the new EPA PM 2.5 standard, possible additional Clean Air emissions standards, access to adequate supplies of scrap tires, quality of processed tire derived fuel, and the possibility of creating a commodity market through the development of ASTM TDF standards.
Fluoride removal performance of glass derived hydroxyapatite
Liang, Wen; Zhan, Lei; Piao, Longhua; Russel, Christian
2011-02-15
Research highlights: {yields} Novel sodium calcium borate glass derived hydroxyapatite (G-HAP) is prepared. {yields} Micro-G-HAP adsorbs F{sup -} ions in solutions more effectively than commercial nano-HAP. {yields} The adsorption kinetics and isotherms are well fitted by a second order kinetic model and Freundlich isotherm model. -- Abstract: A novel sodium calcium borate glass derived hydroxyapatite (G-HAP) with different ranges of particle size was prepared by immersion sodium calcium borate glass in 0.1 M K{sub 2}HPO{sub 4} solution by the ratio of 50 g L{sup -1} for 7 days. The unique advantage of G-HAP for the adsorption of fluoride ions in solutions was studied. The effects of size and quantity of particles, pH value and adsorption time on adsorption performance were investigated. The maximum adsorption capacity was 17.34 mg g{sup -1} if 5 g L{sup -1}, <100 {mu}m G-HAP was added to a solution with an initial pH value of 6.72 and the adsorption time was 12 h. The results showed that the micro-G-HAP could immobilize F{sup -} in solution more effectively than commercial nano-HAP, which makes potential application of the G-HAP in removing the fluoride ions from wastewater. The adsorption kinetics and isotherms for F{sup -} could be well fitted by a second order kinetic model and Freundlich isotherm model respectively, which could be used to describe the adsorption behavior. The mechanism of G-HAP in immobilizing F{sup -} from aqueous solutions was investigated by the X-ray diffraction (XRD), infrared spectra (IR) and scanning electron microscopy (SEM).
Radiation Protection Using Carbon Nanotube Derivatives
NASA Technical Reports Server (NTRS)
Conyers, Jodie L., Jr.; Moore, Valerie C.; Casscells, S. Ward
2010-01-01
BHA and BHT are well-known food preservatives that are excellent radical scavengers. These compounds, attached to single-walled carbon nanotubes (SWNTs), could serve as excellent radical traps. The amino-BHT groups can be associated with SWNTs that have carbolyxic acid groups via acid-base association or via covalent association. The material can be used as a means of radiation protection or cellular stress mitigation via a sequence of quenching radical species using nano-engineered scaffolds of SWNTs and their derivatives. It works by reducing the number of free radicals within or nearby a cell, tissue, organ, or living organism. This reduces the risk of damage to DNA and other cellular components that can lead to chronic and/or acute pathologies, including (but not limited to) cancer, cardiovascular disease, immuno-suppression, and disorders of the central nervous system. These derivatives can show an unusually high scavenging ability, which could prove efficacious in protecting living systems from radical-induced decay. This technique could be used to protect healthy cells in a living biological system from the effects of radiation therapy. It could also be used as a prophylactic or antidote for radiation exposure due to accidental, terrorist, or wartime use of radiation- containing weapons; high-altitude or space travel (where radiation exposure is generally higher than desired); or in any scenario where exposure to radiation is expected or anticipated. This invention s ultimate use will be dependent on the utility in an overall biological system where many levels of toxicity have to be evaluated. This can only be assessed at a later stage. In vitro toxicity will first be assessed, followed by in vivo non-mammalian screening in zebra fish for toxicity and therapeutic efficacy.
Revisiting satellite derived tropospheric NO2 trends
NASA Astrophysics Data System (ADS)
Richter, Andreas; Hilboll, Andreas; Burrows, John P.
2015-04-01
Nitrogen dioxide levels can be used as tracer of anthropogenic pollution as NOx, the sum of NO and NO2, is released during fossil fuel combustion. With its short atmospheric lifetime, atmospheric NO2 can be easily linked to its sources. Using its structured absorption cross section in the blue spectral region, NO2 amounts can be derived from measurements of backscattered solar radiation with the help of Differential Optical Absorption Spectroscopy measurements. Satellite retrievals of tropospheric NO2 became possible with the launch of the GOME instrument in 1995, and since then a series of instruments including SCIAMACHY, GOME-2 and OMI provide spectral data which can be used to quantify NO2 columns in the troposphere. Using these observations, spatial distributions of NO2, its sources and transport pathways as well as temporal changes have been investigated over the last years. In particular the latter have shown remarkable atmospheric developments with large reductions of NO2 levels in many industrialised countries and dramatic increases in regions with growing economies, most notably in China but also in many other countries. In this study, recent trends of satellite derived NO2 columns are evaluated using data from all available instruments with a focus on the last years. Combination of data taken from the two GOME-2 instruments and OMI improves coverage and sensitivity, and also provides important constraints on the reliability of the satellite data set. As in previous studies, large changes in NO2 columns are found in many regions, in particular over China where after two years of stagnating NO2 levels an unexpected substantial reduction is observed for 2014.
Cardiovascular activity of the chiral xanthone derivatives.
Szkaradek, Natalia; Rapacz, Anna; Pytka, Karolina; Filipek, Barbara; ?elaszczyk, Dorota; Szafra?ski, Przemys?aw; S?oczy?ska, Karolina; Marona, Henryk
2015-10-15
A series of 6 derivatives of xanthone were synthesized and evaluated for cardiovascular activity. The following pharmacological experiments were conducted: the binding affinity for adrenoceptors, the influence on the normal electrocardiogram, the effect on the arterial blood pressure, the effect on blood pressor response and prophylactic antiarrhythmic activity in adrenaline induced model of arrhythmia (rats, iv). Two compounds revealed nanomolar affinity for ?1-adrenoceptor which was correlated with the strongest cardiovascular (antiarrhythmic and hypotensive) activity in animals' models. They were enantiomers of previously described (R,S)-4-(2-hydroxy-3-(4-(2-methoxyphenyl)piperazin-1-yl)propoxy)-9H-xanthen-9-one hydrochloride and revealed similar antiarrhythmic potential in adrenaline induced model of arrhythmia in rats after intravenous injection (ED50=0.53mg/kg and 0.81mg/kg, respectively). These values were lower than values obtained for reference drug urapidil. These compounds were more active in this experiment than urapidil (ED50=1.26mg/kg). The compound 5 administered iv at doses of 0.62-2.5mg/kg at the peak of arrhythmia prevented and/or reduced the number of premature ventricular beats in a statistically significant manner. The ED50 value was 1.20mg/kg. The S-enantiomer (6) given at the same doses did not show therapeutic antiarrhythmic activity in this model. These compounds significantly decreased the systolic and diastolic blood pressure throughout the whole observation period in anesthetized, normotensive rats. The studied enantiomers showed higher toxicity than urapidil, but imperceptibly higher that another cardiovascular drugs, that is, carvedilol or propranolol. They were also evaluated for mutagenic potential in the Ames (Salmonella) test. It was found that at the concentrations tested the compounds were non mutagenic when compared to solvent control. Results were quite promising and suggested that in the group of xanthone derivatives new potential antiarrhythmics and hypotensives might be found. PMID:26386822
21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.
Code of Federal Regulations, 2010 CFR
2010-04-01
...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...
77 FR 56067 - Changes To Implement Derivation Proceedings
Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-11
...proceeding and an opportunity for discovery. One comment suggested expanded discovery for derivations, since...allegation of derivation. Discovery prior to institution is...the respondent acquired knowledge of the claimed...
40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).
Code of Federal Regulations, 2013 CFR
2013-07-01
...2013-07-01 2013-07-01 false Salt of polyalkylenepolyamine derivative (generic...Specific Chemical Substances § 721.10328 Salt of polyalkylenepolyamine derivative (generic...chemical substance identified generically as salt of polyalkylenepolyamine...
40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).
Code of Federal Regulations, 2012 CFR
2012-07-01
...2012-07-01 2012-07-01 false Salt of polyalkylenepolyamine derivative (generic...Specific Chemical Substances § 721.10328 Salt of polyalkylenepolyamine derivative (generic...chemical substance identified generically as salt of polyalkylenepolyamine...
21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.
Code of Federal Regulations, 2014 CFR
2014-04-01
...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...
21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.
Code of Federal Regulations, 2012 CFR
2012-04-01
...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...
21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.
Code of Federal Regulations, 2011 CFR
2011-04-01
...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...
21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.
Code of Federal Regulations, 2013 CFR
2013-04-01
...ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110...derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus niveus, and...
21 CFR 184.1282 - Dill and its derivatives.
Code of Federal Regulations, 2012 CFR
2012-04-01
...184.1282 Dill and its derivatives. (a) Dill (American or European) is the herb and seeds from Anethum graveolens L., and dill (Indian) is the herb and seeds from Anethum sowa, D.C. Its derivatives include essential oils,...
21 CFR 184.1282 - Dill and its derivatives.
Code of Federal Regulations, 2011 CFR
2011-04-01
...184.1282 Dill and its derivatives. (a) Dill (American or European) is the herb and seeds from Anethum graveolens L., and dill (Indian) is the herb and seeds from Anethum sowa, D.C. Its derivatives include essential oils,...
21 CFR 184.1282 - Dill and its derivatives.
Code of Federal Regulations, 2014 CFR
2014-04-01
...184.1282 Dill and its derivatives. (a) Dill (American or European) is the herb and seeds from Anethum graveolens L., and dill (Indian) is the herb and seeds from Anethum sowa, D.C. Its derivatives include essential oils,...
21 CFR 184.1282 - Dill and its derivatives.
Code of Federal Regulations, 2013 CFR
2013-04-01
...184.1282 Dill and its derivatives. (a) Dill (American or European) is the herb and seeds from Anethum graveolens L., and dill (Indian) is the herb and seeds from Anethum sowa, D.C. Its derivatives include essential oils,...
A general entry to C7-borono indole derivatives
Fenton, Owen S. (Owen Shea)
2012-01-01
The development of a methodology to access C7 pinacolatoboron substituted indole derivatives is described. It has been applied to indole, tryptophan, and tryptamine derivatives. Further functionalization to a C7 phenolic ...
21 CFR 184.1317 - Garlic and its derivatives.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 3 2010-04-01 2009-04-01 true Garlic and its derivatives. 184.1317 Section...Substances Affirmed as GRAS § 184.1317 Garlic and its derivatives. (a) Garlic is the fresh or dehydrated bulb or cloves...
40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).
Code of Federal Regulations, 2014 CFR
2014-07-01
...2014-07-01 2014-07-01 false Salt of polyalkylenepolyamine derivative...Substances § 721.10328 Salt of polyalkylenepolyamine derivative...substance identified generically as salt of polyalkylenepolyamine...uses are: (i) Release to water. Requirements as...
[The synthesis of galactopyranosyl-substituted derivatives of pheophorbide].
Aksenova, A A; Sebiakin, Iu L; Mironov, A F
2000-02-01
New pheophorbide and pyropheophorbide derivatives containing carbohydrate fragments, derivatives of galactopyranose, were synthesized. Galactopyranosylpheophorbide and galactopyranosylpyropheophorbide with free hydroxyl groups were found to be water-soluble and useful as sensitizers in photodynamic therapy of cancer. PMID:10808408
Automation of Nested Matrix and Derivative Operations Robert Kalaba
Tesfatsion, Leigh
Automation of Nested Matrix and Derivative Operations Robert Kalaba Departments of Electrical of special functions a=x, b=y, c = ab, (4) a=log(c), z=a+d. #12;Automation of Matrix Derivative Operations
Michalska, Karolina; Chang, Changsoo; Mack, Jamey C; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R
2012-11-01
In vitro growth experiments have demonstrated that aromatic compounds derived from lignin can be metabolized and represent a major carbon resource for many soil bacteria. However, the proteins that mediate the movement of these metabolites across the cell membrane have not been thoroughly characterized. To address this deficiency, we used a library representative of lignin degradation products and a thermal stability screen to determine ligand specificity for a set of solute-binding proteins (SBPs) from ATP-binding cassette (ABC) transporters. The ligand mapping process identified a set of proteins from Alphaproteobacteria that recognize various benzoate derivatives. Seven high-resolution crystal structures of these proteins in complex with four different aromatic compounds were obtained. The protein-ligand complexes provide details of molecular recognition that can be used to infer binding specificity. This structure-function characterization provides new insight for the biological roles of these ABC transporters and their SBPs, which had been previously annotated as branched-chain amino-acid-binding proteins. The knowledge derived from the crystal structures provides a foundation for development of sequence-based methods to predict the ligand specificity of other uncharacterized transporters. These results also demonstrate that Alphaproteobacteria possess a diverse set of transport capabilities for lignin-derived compounds. Characterization of this new class of transporters improves genomic annotation projects and provides insight into the metabolic potential of soil bacteria. PMID:22925578
Wei, Wei; Wu, Song; Wang, Xiaolin; Sun, Chris Kin-Wai; Yang, Xiaoyang; Yan, Xinrui; Chua, Mei-Sze; So, Samuel
2014-07-30
The molecular co-chaperone CDC37 is over-expressed in hepatocellular carcinoma (HCC) cells, where it functions with HSP90 to regulate the activity of protein kinases in multiple oncogenic signaling pathways that contribute towards hepatocarcinogenesis. Disruption of these signaling pathways via inhibition of HSP90/CDC37 interaction is therefore a rational therapeutic approach. We evaluated the anti-tumor effects of celastrol, pristimerin, and two novel derivatives (cel-D2, and cel-D7) on HCC cell lines in vitro and on orthotopic HCC patient-derived xenografts in vivo. All four compounds preferentially inhibited viability of HCC cells in vitro,and significantly inhibited the growth of three orthotopic HCC patient-derived xenografts in vivo; with the novel derivatives cel-D2 and cel-D7 exhibiting lower toxicity. All four compounds also induced cell apoptosis; and promoted degradation and inhibited phosphorylation of protein kinases in the Raf/MEK/ERK and PI3K/AKT/mTOR signaling pathways. We demonstrated that HSP90/CDC37 antagonists are potentially broad spectrum agents that might be beneficial for treating the heterogeneous subtypes of HCC, either as monotherapy, or in combination with other chemotherapeutic agents. PMID:25051375
Alternative derivation of the response of interferometric gravitational wave detectors
Cornish, Neil J.
2009-10-15
It has recently been pointed out by Finn that the long-standing derivation of the response of an interferometric gravitational wave detector contains several errors. Here I point out that a contemporaneous derivation of the gravitational wave response for spacecraft doppler tracking and pulsar timing avoids these pitfalls, and when adapted to describe interferometers, recovers a simplified version of Finn's derivation. This simplified derivation may be useful for pedagogical purposes.
Kinetic Theory Derivation of the Adiabatic Law for Ideal Gases.
ERIC Educational Resources Information Center
Sobel, Michael I.
1980-01-01
Discusses how the adiabatic law for ideal gases can be derived from the assumption of a Maxwell-Boltzmann (or any other) distribution of velocities--in contrast to the usual derivations from thermodynamics alone, and the higher-order effect that leads to one-body viscosity. An elementary derivation of the adiabatic law is given. (Author/DS)
How Are Derivatives Used? Evidence from the Mutual Fund Industry
Jennifer Lynch Koski; Jeffrey Pontiff
1999-01-01
We investigate investment managers' use of derivatives by comparing return distributions for equity mutual funds that use and do not use derivatives. In contrast to public perception, derivative users have risk exposure and return performance that are similar to nonusers. We also analyze changes in fund risk in response to prior fund performance. Changes in risk are substantially less severe
Derivation and definition of a linear aircraft model
NASA Technical Reports Server (NTRS)
Duke, Eugene L.; Antoniewicz, Robert F.; Krambeer, Keith D.
1988-01-01
A linear aircraft model for a rigid aircraft of constant mass flying over a flat, nonrotating earth is derived and defined. The derivation makes no assumptions of reference trajectory or vehicle symmetry. The linear system equations are derived and evaluated along a general trajectory and include both aircraft dynamics and observation variables.
NIST Special Publication 800-108 Recommendation for Key Derivation
NIST Special Publication 800-108 Recommendation for Key Derivation Using Pseudorandom Functions and Technology Patrick Gallagher, Deputy Director #12;SP 800-108 Recommendation for Key Derivation Using 2 #12;SP 800-108 Recommendation for Key Derivation Using Pseudorandom Functions Acknowledgements
Inhibition of Mammary Carcinoma Growth by Retinoidal Benzoic Acid Derivatives
Joseph A. Fontana; Peter D. Hobbs; Marcia I. Dawson
1988-01-01
The growth of many breast carcinoma cell lines is inhibited by vitamin A, and derivatives as well as synthetic retinoids. New retinoidal derivatives have recently been synthesized. These retinoidal benzoic acid derivatives displayed enhanced potency in their ability to reverse hamster tracheal keratinization and inhibit ornithine decarboxylase induction in mouse epidermis. We therefore screened a series of analogues of these
Partial Derivates of Regular Expressions and Finite Automata Constructions
Valentin M. Antimirov
1995-01-01
. We introduce a notion of a partial derivative of a regular expression.It is a generalization to the non-deterministic case of the knownnotion of a derivative invented by Brzozowski. We give a constructive definitionof partial derivatives, study their properties, and employ them todevelop a new algorithm for turning regular expressions into relativelysmall NFA and to provide certain improvements to Brzozowski's
Satellite Products and Services Review Board ATBD: Satellite-Derived
Miami, University of
Satellite Products and Services Review Board ATBD: Satellite-Derived Ocean Heat Content Version 1.0 July 2012 ___________________________________ #12;NOAA /RSMAS ATBD : Satellite-Derived Ocean Heat/STAR) #12;NOAA /RSMAS ATBD : Satellite-Derived Ocean Heat Content Product Page 3 of 32 TABLE OF CONTENTS
Derivation of low flow distribution functions using copulas
NASA Astrophysics Data System (ADS)
Yu, Kun-xia; Xiong, Lihua; Gottschalk, Lars
2014-01-01
The method of deriving copula-based low flow distributions is proposed.Statistical dependence is detected among the characteristics of low flow event.Copula-based derived distributions can perform well against observations.Choice of marginal distributions is important in copula-based derived distribution.It is useful to study the impacts of climate change/human activities on low flows.
Exact Multisoliton Solutions of General Nonlinear Schrödinger Equation with Derivative
Li, Qi; Duan, Qiu-yuan; Zhang, Jian-bing
2014-01-01
Multisoliton solutions are derived for a general nonlinear Schrödinger equation with derivative by using Hirota's approach. The dynamics of one-soliton solution and two-soliton interactions are also illustrated. The considered equation can reduce to nonlinear Schrödinger equation with derivative as well as the solutions. PMID:25013858
Simplified Derivation of the Fokker-Planck Equation.
ERIC Educational Resources Information Center
Siegman, A. E.
1979-01-01
Presents an alternative derivation of the Fokker-Planck equation for the probability density of a random noise process, starting from the Langevin equation. The derivation makes use of the first two derivatives of the Dirac delta function. (Author/GA)
Derivation of the Freundlich Adsorption Isotherm from Kinetics
ERIC Educational Resources Information Center
Skopp, Joseph
2009-01-01
The Freundlich adsorption isotherm is a useful description of adsorption phenomena. It is frequently presented as an empirical equation with little theoretical basis. In fact, a variety of derivations exist. Here a new derivation is presented using the concepts of fractal reaction kinetics. This derivation provides an alternative basis for…
Pressure derivatives of the bulk modulus
NASA Astrophysics Data System (ADS)
Hofmeister, A. M.
1991-12-01
Simple relations between the first (or second) pressure derivative of the bulk modulus and first (or second) thermal Grüneisen parameter ?Th (or qTh) are derived from equations that relate KT(P) to vibrational frequencies Vi as a function of pressure for cubic structures or those that have only one nearest neighbor distance, by assuming that the mode Grüneisen parameters, ?i = -? ln vi/? ln V, are approximately equal. The free volume equation results, which holds within experimental uncertainties for about 70% for solids meeting the symmetry requirements. Agreement is poor for compounds with the rutile structure, which have the largest range of ?i observed. Another result is a three-parameter equation of state, KoK?o = (5/3 - K'o)2 - (5/3 - K'o)qTh(0) - (K'o - 1)2. All available experimental determinations of K?o are bracketed by the spectroscopic limits for qTh. Use of the average value of zero for qTh (or qTh calculated from other thermodynamic parameters) gives the proper sign for K?o and nearly the same values as experiment, suggesting that this approximate equation can be used predictively. The equations involving K?o and K'o are probably valid for any structure, if the ?i are roughly equal, although this most likely occurs for solids that compress nearly isotropically. The new formula, with qTh of zero, give values similar to that obtained from the Vinet-Ferrante-Rose-Smith equation at low K'o gives the same values as the Birch-Murnaghan (third-order finite strain) equation near K'o of 4, and gives nearly equal values as the Grover-Getting-Kennedy equation of state at high K'o. Physically reasonable positive values of K?o as K'o approaches zero are obtained only from the new equation of state and that of Vinet et al. Comparison of the new equation of state with third-order finite strain suggests that the latter is also likely to be incorrect at high K'o and thus should be cautiously applied to V(P) for liquids.
NASA Technical Reports Server (NTRS)
Nguyen, L. T.
1974-01-01
A theoretical investigation was conducted to determine the importance of the lateral acceleration (beta) derivatives in the extraction of lateral-directional stability derivatives for swept wing airplanes at high angles of attack. Representative values of lateral acceleration derivatives in yaw and roll (Cn beta and Cl beta) were used in a computer program to generate representative flight motions at several angles of attack and altitudes. The computer-generated motions were then subjected to a parameter identification process based on a modified Newton-Raphson method. Two identification techniques were evaluated, one which included the beta derivatives and one which neglected them. The results of the study indicate that omission of the beta derivatives from mathematical models used in the derivative-extraction techniques can produce erroneous values for the lateral-directional stability derivatives particularly at high angles of attack, where the beta derivatives are large. The largest errors occur in the dynamic derivatives, but large errors may also occur in the static derivatives for cases in which the beta derivatives have large effects on the flight motions of the airplane. In addition, the resulting identified mathematical models provide poor motion prediction as well as erroneous predictions of dynamic modal characteristics. These results strongly indicate that the effects of beta derivatives should be considered in any attempt to extract lateral-directional aerodynamic parameters at high angles of attack.
Amino acid derivatives as transdermal permeation enhancers.
Jan?šová, Barbora; Skolová, Barbora; Tükörová, Katarína; Wojnarová, Lea; Sim?nek, Tomáš; Mlad?nka, P?emysl; Filipský, Tomáš; Ríha, Michal; Roh, Jaroslav; Palát, Karel; Hrabálek, Alexandr; Vávrová, Kate?ina
2013-01-28
Transdermal permeation enhancers are compounds that temporarily decrease skin barrier properties to promote drug flux. In this study, we investigated enhancers with amino acids (proline, sarcosine, alanine, ?-alanine, and glycine) attached to hydrophobic chain(s) via a biodegradable ester link. The double-chain lipid-like substances displayed no enhancing effect, whereas single-chain substances significantly increased skin permeability. The proline derivative l-Pro2 reached enhancement ratios of up to 40 at 1% concentration, which is higher than that of the well-established and standard enhancers Azone, DDAIP, DDAK, and Transkarbam 12. No stereoselectivity was observed. l-Pro2 acted synergistically with propylene glycol. Infrared studies revealed that l-Pro2 forms a separate liquid ordered phase in the stratum corneum lipids and has no significant effect on proteins. l-Pro2 action was at least partially reversible as measured by skin electrical impedance. Toxicity in keratinocyte (HaCaT) and fibroblast (3T3) cell lines showed IC(50) values ranging from tens to hundreds of ?M, which is comparable with standard enhancers. Furthermore, l-Pro2 was rapidly decomposed in plasma. In vivo transdermal absorption studies in rats confirmed the enhancing activity of l-Pro2 and suggested its negligible skin toxicity and minimal effect on transepidermal water loss. These properties make l-Pro2 a promising candidate for potential clinical use. PMID:23154194
Surface Emissivity Derived From Multispectral Satellite Data
NASA Technical Reports Server (NTRS)
Minnis, P.; Smith, W. L., Jr.; Young, D. F.
1998-01-01
Surface emissivity is critical for remote sensing of surface skin temperature and infrared cloud properties when the observed radiance is influenced by the surface radiation. It is also necessary to correctly compute the longwave flux from a surface at a given skin temperature. Surface emissivity is difficult to determine because skin temperature is an ill-defined parameter. The surface-emitted radiation may arise from a range of surface depths depending on many factors including soil moisture, vegetation, surface porosity, and heat capacity. Emissivity can be measured in the laboratory for pure surfaces. Transfer of laboratory measurements to actual Earth surfaces, however, is fraught with uncertainties because of their complex nature. This paper describes a new empirical approach for estimating surface skin temperature from a combination of brightness temperatures measured at different infrared wavelengths with satellite imagers. The method uses data from the new Geostationary Operational Environmental Satellite (GOES) imager to determine multispectral emissivities from the skin temperatures derived over the ARM Southern Great Plains domain.
Polyimides Derived from Novel Asymmetric Dianhydrides
NASA Technical Reports Server (NTRS)
Chuang, Chun-Hua (Inventor)
2012-01-01
This invention relates to the compositions and processes for preparing thermoset and thermoplastic polyimides derived from novel asymmetrical dianhydrides: specifically 2,3,3',4' benzophenone dianhydride (a-BTDA), and 3,4'-(hexafluoroisopropylidene)diphthalic anhydride (a-6FDA). The a-BTDA anhydride is prepared by Suzuki coupling with catalysts from a mixed anhydride of 3,4-dimethylbenzoic acid or 2,3-dimethylbenzoic acid with 2,3-dimethylphenylboronic acid or 3,4-dimethylphenylboronic acid respectively, to form 2,3,3',4'-tetramethylbenzophenone which is oxidized to form 2,3,3',4'-benzophenonetetracarboxylic acid followed by cyclodehydration to obtain a-BTDA. The a-6FDA is prepared by nucleophilic triflouoromethylation of 2,3,3',4'-tetramethylbenzophenone with trifluoromethyltrimethylsilane to form 3,4'-(trifluoromethylmethanol)-bis(o-xylene) which is converted to 3,4'-(hexafluoroisopropylidene-bis(o-xylene). The 3,4'-(hexafluoroisopropylidene)-bis(o-xylene) is oxidized to the corresponding tetraacid followed by cyclodehydration to yield a-6FDA.
4-Aminoquinoline Derivatives as Potential Antileishmanial Agents.
Antinarelli, Luciana M R; Dias, Rafael M P; Souza, Isabela O; Lima, Wallace P; Gameiro, Jacy; da Silva, Adilson D; Coimbra, Elaine S
2015-10-01
The leishmanicidal activity of a series of 4-aminoquinoline (AMQ) derivatives was assayed against Leishmania amazonensis. This activity against the intracellular parasite was found stronger than for L. amazonensis promastigotes. Neither compound was cytotoxic against macrophages. The compound AMQ-j, which exhibited a strong activity against promastigotes and amastigotes of L. amazonensis (IC50 values of 5.9 and 2.4 ?g/mL, respectively) and similar leishmanicidal activity to reference drugs, was chosen for studies regarding its possible mechanism of action toward parasite death. The results showed that the compound AMQ-j induced depolarization of the mitochondrial membrane potential in promastigotes and in L. amazonensis-infected macrophages, but not in uninfected macrophages. Furthermore, the depolarization of the mitochondrial membrane potential was dose dependent in infected macrophages. We have established that promastigotes and L. amazonensis-infected macrophages treated with AMQ-j were submitted to oxidative stress. This is in line with the increase in the level of reactive oxygen species (ROS). Leishmania amazonensis-infected macrophages treated with AMQ-j did not show a significant increase in the production of nitric oxide. Our results indicate the effective and selective action of AMQ-j against L. amazonensis, and its mechanism of action appears to be mediated by mitochondrial dysfunction associated with ROS production. PMID:25682728
Plant-derived biomolecules in fermented cabbage.
Tolonen, Marja; Taipale, Marianne; Viander, Britta; Pihlava, Juha-Matti; Korhonen, Hannu; Ryhänen, Eeva-Liisa
2002-11-01
The formation of plant-derived biomolecules during sauerkraut fermentation was studied. Cabbage was fermented with a starter culture, and the results were compared to the results of spontaneous fermentation. The concentration of flavonoids and glucosinolates was analyzed by HPLC, and that of the glucosinolate breakdown products, by GC-MS. Of the 20 different flavonoids tested, only kaempferol was found (0.9 mg/ kg FW, fresh weight). The content of kaempferol remained constant in the cabbage fiber matrix over the fermentation process. The nitrite concentration was below the detection limit in both fermentations. The total glucosinolate content in the raw material was 3.71 micro mol/g DW, dry weight. Glucosinolates were totally decomposed in both fermentations during two weeks, and different types of breakdown products were formed. Isothiocyanates, indole-3-carbinol, goitrin, allyl cyanide, and nitriles were determined in the fermented cabbage. Isothiocyanates and allyl cyanide were the predominant breakdown products in both fermentations. Sulforaphane nitrile and goitrin were found only in small quantities in the end products. PMID:12405778
Biopharmaceutical profiling of new antitumor pyrazole derivatives.
Anuta, Valentina; Nitulescu, George Mihai; Dinu-Pîrvu, Cristina Elena; Olaru, Octavian Tudorel
2014-01-01
Several new pyrazole derivatives have demonstrated promising antiproliferative and cytotoxic effects, but their poor solubility raised concerns over possible biopharmaceutical limitations. In order to improve their pharmaceutical potential we performed the biopharmaceutical profiling for nine pyrazole compounds using in vitro and computational methods. The experimental solubility was determined in five different media using a validated HPLC method. Although the experimental solubility was lower than the predicted one, a good linear relationship was observed. The results also indicated a minimal impact of endogenous tensioactives on solubility, suggesting dissolution rate limited absorption. The in silico experiments were focused on identification of molecular determinants of solubility, evaluation of drug-likeness, prediction of in vivo absorption based on mechanistic models, as well as identification of the main factors that could impact on the oral bioavailability. The results suggested that dose, solubility and particle size are the main determinants of absorption, whereas permeability has little effect, confirming the BCS Class II behavior of the compounds. The present investigation was able to rank the tested compounds in terms of biopharmaceutical behavior, and indicated the B3 series compounds as having a more favorable absorption profile making them the main candidates for advance to the pre-clinical in vivo studies. PMID:25314601
Derivation of dose conversion factors for tritium
Killough, G. G.
1982-03-01
For a given intake mode (ingestion, inhalation, absorption through the skin), a dose conversion factor (DCF) is the committed dose equivalent to a specified organ of an individual per unit intake of a radionuclide. One also may consider the effective dose commitment per unit intake, which is a weighted average of organ-specific DCFs, with weights proportional to risks associated with stochastic radiation-induced fatal health effects, as defined by Publication 26 of the International Commission on Radiological Protection (ICRP). This report derives and tabulates organ-specific dose conversion factors and the effective dose commitment per unit intake of tritium. These factors are based on a steady-state model of hydrogen in the tissues of ICRP's Reference Man (ICRP Publication 23) and equilibrium of specific activities between body water and other tissues. The results differ by 27 to 33% from the estimate on which ICRP Publication 30 recommendations are based. The report also examines a dynamic model of tritium retention in body water, mineral bone, and two compartments representing organically-bound hydrogen. This model is compared with data from human subjects who were observed for extended periods. The manner of combining the dose conversion factors with measured or model-predicted levels of contamination in man's exposure media (air, drinking water, soil moisture) to estimate dose rate to an individual is briefly discussed.
Antimicrobial activity of resin acid derivatives.
Savluchinske-Feio, Sonia; Curto, Maria João Marcelo; Gigante, Bárbara; Roseiro, J Carlos
2006-09-01
The wide potential of resin acids as bioactive agents gave rise to a growing effort in the search for new applications of the natural forms and their derivatives. In some of these compounds, the antimicrobial activity is associated to the presence in the molecules of functional groups such as the hydroxyl, aldehyde, and ketone or to their cis or trans configurations. The resin acid family covers a spectrum of antimicrobial activities against several microorganisms, from bacteria to fungi, in which the mode of action was studied by electron microscopy. The morphological alterations are consistent with an unspecific mode of action causing inhibition of the fungal growth or damaging the fungal cells in parallel with a mechanism of resistance based on the retention of the compound by the lipid accumulation. The sterol composition of phytopathogenic fungi Botrytis cinerea and Lophodermium seditiosum treated with methyl cis-7-oxo-deisopropyldehydroabietate revealed the presence of ergosterol (M+ 396) and dihydroergosterol (M+ 398) in both cultures showing that this compound did not interfere with the ergosterol metabolic pathway of both fungi. PMID:16896605
Light olefins from coal derived syngas
Sardesai, A.; Tartamella, T.; Lee, S. [Univ. of Akron, OH (United States). Dept. of Chemical Engineering
1996-12-31
Synthesis of methanol from coal-derived synthesis gas is a well established technology, and methanol has been used as a feedstock for the synthesis of gasoline range hydrocarbons and olefins commercially. However, an efficient hydrocarbon synthesis process, based on a single-stage dimethyl ether synthesis from syngas, has been developed at the University of Akron. This UA/EPRI`s DTH (Dimethyl Ether to Hydrocarbons) process has significant advantages over its counterpart methanol conversion process in the areas of heat duties, hydrocarbon selectivities, product yield, and reactor size. Lower olefins are the intermediate products in the conversion of dimethyl ether to aromatic hydrocarbons. C{sub 2}-C{sub 4} olefins can be selectively produced by varying the operating parameters of the process, viz., temperature, pressure, DME concentration in the feed, space time, acidity of the catalyst, etc. The present work focuses on the effect of key process variables on the dimethyl ether conversion to lower olefins in a fixed bed microreactor system over ZSM-5 type zeolite catalyst. Experimental results with respect to gaseous hydrocarbon product yields and selectivities have been examined in this study.
Bioactive quinic acid derivatives from Ageratina adenophora.
Zhang, Mei; Liu, Wan-Xue; Zheng, Meng-Fei; Xu, Qiao-Lin; Wan, Fang-Hao; Wang, Jing; Lei, Ting; Zhou, Zhong-Yu; Tan, Jian-Wen
2013-01-01
A novel quinic acid derivative, 5-O-trans-o-coumaroylquinic acid methyl ester (1), together with three known ones, chlorogenic acid methyl ester (2), macranthoin F (3) and macranthoin G (4), were isolated from the aerial parts of the invasive plant Ageratina adenophora (Spreng.). The structure of new compound 1 was elucidated on the basis of extensive spectroscopic analysis, including 1D- and 2D-NMR techniques. Compounds 2-4 were isolated from plant A. adenophora for the first time. All the compounds showed in vitro antibacterial activity toward five assayed bacterial strains, especially 3 and 4, which showed in vitro antibacterial activity against Salmonella enterica with MIC values of 7.4 and 14.7 ?M, respectively. Compound 1 was further found to display in vitro anti-fungal activity against spore germination of Magnaporthe grisea with an IC?? value 542.3 µM. These four compounds were also tested for their antioxidant activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radical. PMID:24241153
Avidin binding of radiolabeled biotin derivatives.
Garlick, R K; Giese, R W
1988-01-01
Three N-acyl derivatives of biotinylethylenediamine were prepared: I, biotinylamidoethyl-3-(3-[125I]iodo-4-hydroxyphenyl)propionamide; II, biotinylamidoethyl-[3H]acetamide; and III, biotinylamidoethyl-3-(3,5-[125I]diiodo-4-hydroxyphenyl)propionamid e. Each compound was combined with a large excess of avidin, yielding 1:1 molar complexes. Aside from a small fraction of each complex that dissociated more rapidly, the dissociation half-lives of these complexes were: I, 41 days; II, 4.4 days; and III, 148 days. The iodo- (mono or di) hydroxyphenylpropionyl moieties of I and III, therefore, contribute significantly to the binding strength of these compounds toward avidin. We also formed 4:1 complexes of I, II, and III with avidin (compound in excess), each of which exhibited biphasic dissociation, with initial half-lives of 4, 3.2, and 24 days, respectively. Thus, I or especially III potentially can be used as a sensitive tracer in quantitative studies with avidin. PMID:3275639
Magnetic characterization of ferrocene derived carbon nanotubes
NASA Astrophysics Data System (ADS)
Malone, Johnathan
Carbon nanotubes (CNTs) functionalized/embedded with ferromagnetic particles have several important advantages as materials for magnetic applications. The presence of ferromagnetic particles in a carbon matrix can substantially change the magnetic properties of CNT-based composites. For example, iron filled CNTs have been used as probes in magnetic force microscopy (MFM), and have potential in magnetic data storage applications. In addition, encapsulation in nanotubes provides iron nanoparticles with resistance to oxidation and mechanical damage. Chemical vapor deposition (CVD) is one of the most common single-step processes for the fabrication of high quality carbon nanotubes containing varying amounts of embedded ferromagnetic particles. This process results in the effective magnetic functionalization of CNTs and opens the door to numerous new applications. However, in order to optimize these materials for any application, their properties need to be understood. This study explores the ferromagnetic properties of carbon nanotubes containing nano-scaled iron particles which were derived from thermal decomposition of ferrocene. Both room temperature as well as low-temperature magnetic measurements will be presented and the results analyzed in the light of available theory.
The excretion of pethidine and its derivatives
Asatoor, A. M.; London, D. R.; Milne, M. D.; Simenhoff, M. L.
1963-01-01
The excretion of pethidine and its metabolite norpethidine is increased in acid urine and decreased in alkaline urine. Excretion of these two bases is the main route of removal of pethidine from the body if the urine is highly acid. If the urine is alkaline, excretion of the hydrolysis products meperidinic and normeperidinic acids, both as free acids and as conjugates, is the more important means of elimination of the drug. Acidification of the urine with ammonium chloride is indicated in the therapy of cases of pethidine poisoning in patients with reduced metabolic breakdown of the drug by the microsomal enzyme systems within liver cells. Reversed-phase chromatography of the dinitrophenyl derivative of norpethidine may prove to be of forensic importance in the diagnosis of pethidine poisoning or of pethidine addiction. Norpethidine can be detected in the urine by this method for at least 3 days after the last dose of pethidine. Analytical sensitivity is increased by acidification of the urine which produces a temporary rise of the excretion rate. ImagesFig. 7Fig. 6 PMID:13965101
Electrocardiogram derived respiration from QRS slopes.
Lazaro, Jesús Lázaro; Alcaine, Alejandro; Gil, Eduardo; Laguna, Pablo; Bailón, Raquel
2013-01-01
A method for estimation of respiratory rate from electrocardiogram (ECG) signals, based on variations in slopes of QRS complexes, is presented. 12 standard leads, 3 leads from vectorcardiogram (VCG), and 2 additional non-standard leads derived from VCG loops were analysed. A total of 34 slope series were studied, 2 for each analysed lead: slopes between the peak of Q and R waves, and between the peak of R and S waves. Information of QRS slopes series was combined in order to increase the robustness of estimation. Evaluation is performed over a database containing ECG and respiratory signals simultaneously recorded in 17 subjects spontaneously breathing during a tilt table test. Respiratory rate estimation is performed with information of 4 different combinations of QRS slope series. The best results in respiratory rate estimation error terms are 0.72 ± 4.34%(0.46 ± 7.59 mHz). These results outperform those obtained with other known methods, motivating the use of QRS slopes to obtain reliable respiratory rate estimates. PMID:24110587
Gnotobiotic pigs-derivation and rearing.
Miniats, O P; Jol, D
1978-10-01
The procurement, rearing, nutrition and microbiological monitoring of gnotobiotic pigs and a method for conditioning of primary, colostrum-deprived, specific pathogen free pigs is described. As compared to the established hysterectomy and closed hysterotomy methods for the derivation of gnotobiotic piglets an alternative approach, open caesarian section with the sow maintained under general halothane-nitrous oxide anaesthesia and the introduction of each fetus into the sterile isolator via a liquid germicidal trap, was found to be more efficient and equally successful in providing viable and microbiologically sterile piglets. Two sterile commercially available milk diets, a special formula for orphan animals and condensed cow's milk, when the latter was supplemented with injectable vitamin E, selenium and iron, proved adequate for satisfactory health of the animals. Two types of pelleted starter rations, sterilized by 4.5 megarads of gamma irradiation, provided adequately for the nutritional needs of older gnotobiotic pigs. Results of microbiological monitoring indicated that the surgical and rearing methods employed were capable of preventing contamination of the animals with bacteria, mycoplasma, yeasts, molds, protozoa and helminths but probably could not exclude occasional vertically transmitted viral infections. Exposure of the animals for four weeks to selected strains of lactobacilli, fecal streptococci and Escherichia coli did not result in visible disease while they were maintained in isolators and conditioned them for transfer into a conventional microbial environment. PMID:154359
Latent Heating Structures Derived from TRMM
NASA Technical Reports Server (NTRS)
Tao, W.-K.; Smith, E. A.; Adler, R.; Hou, A.; Kakar, R.; Krishnamurti, T.; Kummerow, C.; Lang, S.; Olson, W.; Satoh, S.
2004-01-01
Rainfall is the fundamental variable within the Earth's hydrological cycle because it is both the main forcing term leading to variations in continental and oceanic surface water budgets. The vertical distribution of latent heat release, which is accompanied with rain, modulates large-scale meridional and zonal circulations within the tropics as well as modifying the energetic efficiency of mid-latitude weather systems. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water.This paper focuses on the retrieval of latent heat release from satellite measurements generated by the Tropical Rainfall Measuring Mission 0. The TRMM observatory, whose development was a joint US-Japan space endeavor, was launched in November 1997. TRMM measurements provide an accurate account of rainfall over the global tropics, information which can be .used to estimate the four-dimensional structure of latent heating across the entire tropical and sub-tropical regions. Various algorithm methodologies for estimating latent heating based on rain rate measurements from TRMM observations are described. The strengths and weaknesses of these algorithms, as well as the latent heating products generated by these algorithms, are also discussed along with validation analyses of the products. The investigation paper provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, and concludes with remarks designed to stimulate further research on latent heating retrieval
Deriving Chesapeake Bay Water Quality Standards
Tango, Peter J.; Batiuk, Richard A.
2013-01-01
Achieving and maintaining the water quality conditions necessary to protect the aquatic living resources of the Chesapeake Bay and its tidal tributaries has required a foundation of quantifiable water quality criteria. Quantitative criteria serve as a critical basis for assessing the attainment of designated uses and measuring progress toward meeting water quality goals of the Chesapeake Bay Program partnership. In 1987, the Chesapeake Bay Program partnership committed to defining the water quality conditions necessary to protect aquatic living resources. Under section 303(c) of the Clean Water Act, States and authorized tribes have the primary responsibility for adopting water quality standards into law or regulation. The Chesapeake Bay Program partnership worked with U.S. Environmental Protection Agency to develop and publish a guidance framework of ambient water quality criteria with designated uses and assessment procedures for dissolved oxygen, water clarity, and chlorophyll a for Chesapeake Bay and its tidal tributaries in 2003. This article reviews the derivation of the water quality criteria, criteria assessment protocols, designated use boundaries, and their refinements published in six addendum documents since 2003 and successfully adopted into each jurisdiction's water quality standards used in developing the Chesapeake Bay Total Maximum Daily Load.
Some furfural derivatives as nitrification inhibitors.
Datta, A; Walia, S; Parmar, B S
2001-10-01
Three series of furfural derivatives, namely N-O-furfural oxime ethers, furfural Schiff bases (furfurylidene anilines), and furfural chalcones, have been synthesized and evaluated for nitrification inhibition activity in laboratory incubation studies in typic Ustocrept soil. Furfural oxime ethers and furfural Schiff bases showed potential activity, but furfural chalcones were only mildly active. N-O-ethyl furfural oxime among the oxime ethers, and furfurylidine-4-chloroaniline among the furfural Schiff bases, performed the best. These two compounds showed more than 50% nitrification inhibition on the 45th day at 5% dose as compared to 73% inhibition by nitrapyrin. Activity of furfural oxime ethers decreased with an increase in carbon atoms in the N-O-alkyl side chain. Introduction of a chlorine atom in the phenyl ring of furfurylidene anilines increased the persistence of their activity. N-O-Ethyl furfural oxime and furfurylidine-4-chloroaniline coated urea performed at par with their application in solution form. Ethyl and N-O-isopropyl oxime, as well as chloro- and nitro- substituted Schiff bases, did not reveal any phytotoxicity (adverse effect on germination) on chickpea seeds (Cicer arietinum) even at the highest dose (40 ppm, soil basis). PMID:11600014
Jet flames of a refuse derived fuel
Weber, Roman; Kupka, Tomasz; Zajac, Krzysztof [Institute of Energy Process Engineering and Fuel Technology, Clausthal University of Technology, Agicolastrasse 4, 38 678 Clausthal-Zellerfeld (Germany)
2009-04-15
This paper is concerned with combustion of a refuse derived fuel in a small-scale flame. The objective is to provide a direct comparison of the RDF flame properties with properties of pulverized coal flames fired under similar boundary conditions. Measurements of temperature, gas composition (O{sub 2}, CO{sub 2}, CO, NO) and burnout have demonstrated fundamental differences between the coal flames and the RDF flames. The pulverized coals ignite in the close vicinity of the burner and most of the combustion is completed within the first 300 ms. Despite the high volatile content of the RDF, its combustion extends far into the furnace and after 1.8 s residence time only a 94% burnout has been achieved. This effect has been attributed not only to the larger particle size of fluffy RDF particles but also to differences in RDF volatiles if compared to coal volatiles. Substantial amounts of oily tars have been observed in the RDF flames even though the flame temperatures exceeded 1300 C. The presence of these tars has enhanced the slagging propensity of RDF flames and rapidly growing deposits of high carbon content have been observed. (author)
Locus equations derived from compensatory articulation.
Sussman, H M; Fruchter, D; Cable, A
1995-05-01
Locus equations are linear regressions of the onset of F2 transitions on their offsets. These functions vowel-normalize the F2 transitions such that they are able to characterize consonantal place categories. The purpose of this research was to determine if compensatory articulation due to bite blocks would alter the normally linear relationship between F2 transition onset and offset frequencies or alter the differential slopes and y intercepts of locus equations as a function of stop place. Six speakers, three male and three female, each produced /bVt/, /dVt/, and /gVt/ tokens for ten vowel contexts under normal and bite block conditions. Extremely linear and practically identical scatterplots were obtained in the two speaking conditions. No adaptation to the bite blocks was found when comparing locus equations derived from the initial versus the final bite block trial. Results are discussed in relation to the "orderly output constraint," which postulates a perceptual function for linearly related F2 transition end points within consonantal place categories. PMID:7759651
Avidin binding of radiolabeled biotin derivatives
Garlick, R.K.; Giese, R.W.
1988-01-05
Three N-acyl derivatives of biotinylethylenediamine were prepared: I, biotinylamidoethyl-3-(3-(/sup 125/I)iodo-4-hydroxyphenyl)propionamide; II, biotinylamidoethyl-(/sup 3/H)acetamide; and III, biotinylamidoethyl-3-(3,5-(/sup 125/I)diiodo-4-hydroxyphenyl)propionamid e. Each compound was combined with a large excess of avidin, yielding 1:1 molar complexes. Aside from a small fraction of each complex that dissociated more rapidly, the dissociation half-lives of these complexes were: I, 41 days; II, 4.4 days; and III, 148 days. The iodo- (mono or di) hydroxyphenylpropionyl moieties of I and III, therefore, contribute significantly to the binding strength of these compounds toward avidin. We also formed 4:1 complexes of I, II, and III with avidin (compound in excess), each of which exhibited biphasic dissociation, with initial half-lives of 4, 3.2, and 24 days, respectively. Thus, I or especially III potentially can be used as a sensitive tracer in quantitative studies with avidin.
Establishing data-derived emissions limitations
Rigo, H.G. [Rigo & Rigo Associates, Inc., Berea, OH (United States); Liberson, G. [Environmental Risk Sciences, Inc., Washington, DC (United States)
1997-12-01
The emissions limitations found in regulations and permits have traditionally been set using engineering judgement, commercial considerations and public perception of potential harm and achievability. Given the restricted list of pollutants in Section 129 of the Clean Air Act (CAA) and EPA`s decision to base municipal waste combustor (MWC) Maximum Achievable Control Technology (MACT) Floor determinations on limitations in enforceable permits, the need for determining these values from test data seems to be past. However, this does not stop local jurisdictions from imposing additional requirements. Local regulatory bodies and concerned citizens frequently want to regulate pollutants that are not addressable using EPA`s permit limit procedure; too few permits include limitations on specific emissions. The need to correctly calculate achievable emissions remains. At the very least, it is imperative that correctly calculated limitations be placed in the administrative record supporting a permit so that if a problem occurs, a facility retains the ability to defend itself. Fortunately, emissions limitations can be calculated using statistical techniques that consider both regulatory constraints and source variability. These procedures provide a deterministic, objective link between test results and a lower limit that bounds achievable, data-derived regulatory and permit restrictions.
Antioxidant activities of licorice-derived prenylflavonoids
Kim, Hyo Jung; Seo, Ji-Yeon; Suh, Hwa-Jin; Lim, Soon Sung
2012-01-01
Glycyrrhiza uralensis (or licorice) is a widely used Oriental herbal medicine from which the phenylflavonoids dehydroglyasperin C (DGC), dehydroglyasperin D (DGD), and isoangustone A (IsoA) are derived. The purpose of the present study was to evaluate the antioxidant properties of DGC, DGD, and IsoA. The three compounds showed strong ferric reducing activities and effectively scavenged DPPH, ABTS+, and singlet oxygen radicals. Among the three compounds tested, DGC showed the highest free radical scavenging capacity in human hepatoma HepG2 cells as assessed by oxidant-sensitive fluorescent dyes dichlorofluorescein diacetate and dihydroethidium bromide. In addition, all three compounds effectively suppressed lipid peroxidation in rat tissues as well as H2O2-induced ROS production in hepatoma cells. This study demonstrates that among the three phenylflavonoids isolated from licorice, DGC possesses the most potent antioxidant activity, suggesting it has protective effects against chronic diseases caused by reactive oxygen species as well as potential as an antioxidant food additive. PMID:23346298
Cytotoxicity of a mitochondriotropic quercetin derivative: mechanisms.
Sassi, Nicola; Biasutto, Lucia; Mattarei, Andrea; Carraro, Massimo; Giorgio, Valentina; Citta, Anna; Bernardi, Paolo; Garbisa, Spiridione; Szabò, Ildikò; Paradisi, Cristina; Zoratti, Mario
2012-07-01
The mitochondriotropic compound 7-O-(4-triphenylphosphoniumbutyl)quercetin iodide (Q-7BTPI) in the ?M concentration range caused necrotic death of cultured cells by acting as a prooxidant, with generation of superoxide anion in the mitochondria. Externally added membrane-permeating superoxide dismutase or catalase largely prevented death. Rescue by permeant catalase indicates that the toxicant is H(2)O(2), or reactive species derived from it. Rescue by permeant dismutase suggests the possibility of a chain mechanism of H(2)O(2) production, in which dismutation of superoxide constitutes a termination step. Oxidative stress was due to the presence of free phenolic hydroxyls and to accumulation in mitochondria, since the analogous mitochondriotropic per-O-methylated compound -3,3',4',5-tetra-O-methyl,7-O-(4-triphenylphosphoniumbutyl) quercetin iodide (QTM-7BTPI)-or Quercetin itself induced no or little superoxide production and cell death. Q-7BTPI did not cause a significant perturbation of the mitochondrial transmembrane potential or of respiration in cells. On the other hand its presence led to inhibition of glutathione peroxidase, an effect expected to accentuate oxidative stress by interfering with the elimination of H(2)O(2). An exogenous permeable glutathione precursor determined a strong increase of cellular glutathione levels but did not rescue the cells. Death induction was selective for fast-growing C-26 tumoral cells and mouse embryonic fibroblasts (MEFs) while sparing slow-growing MEFs. This suggests a possible use of Q-7BTPI as a chemotherapeutic agent. PMID:22433608
Amino acids derived from Titan tholins.
Khare, B N; Sagan, C; Ogino, H; Nagy, B; Er, C; Schram, K H; Arakawa, E T
1986-10-01
An organic heteropolymer (Titan tholin) was produced by continuous dc discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mbar pressure, roughly simulating the cloudtop atmosphere of Titan. Treatment of this tholin with 6N HCl yielded 16 amino acids by gas chromatography after derivatization of N-trifluroacetyl isopropyl esters on two different capillary columns. Identifications were confirmed by GC/MS. Glycine, aspartic acid, and alpha- and beta-alanine were produced in greatest abundance; the total yield of amino acids was approximately 10(-2), approximately equal to the yield of urea. The presence of "nonbiological" amino acids, the absence of serine, and the fact that the amino acids are racemic within experimental error together indicate that these molecules are not due to microbial or other contamination, but are derived from the tholin. In addition to the HCN, HC2CN, and (CN)2 found by Voyager, nitriles and aminonitriles should be sought in the Titanian atmosphere and, eventually, amino acids on the surface. These results suggest that episodes of liquid water in the past or future of Titan might lead to major further steps in prebiological organic chemistry on that body. PMID:11542046
Prediction of thermodynamic properties of coal derivatives
Donohue, M.D.
1990-09-01
The purpose of this research program is to understand the relationship between macroscopic thermodynamic properties and the various types of intermolecular forces. Since coal-derived liquids contain a wide variety of compounds, a theory capable of successfully predicting the thermophysical properties for coal processes must take into account the molecular shapes and all significant intermolecular forces: dispersion forces, anisotropic forces due to dipoles and quadrupoles, as well as Lewis acid-base interactions. We have developed the Acid-Base-Perturbed-Anisotropic-Chain Theory (ABPACT), a comprehensive theory that is capable of predicting the thermophysical properties for many systems where these different intermolecular forces are present. The ABPACT can treat non-polar compounds, polar compounds and compounds that associate through Lewis acid-base interactions. In addition to our theoretical work, we have used computer simulations to evaluate (and in some cases correct) the assumptions made in this theory. We also have conducted experiments to help us better understand the interplay of different kinds of interactions in multicomponent mixtures.
Derivatives and credit contagion in interconnected networks
NASA Astrophysics Data System (ADS)
Heise, S.; Kühn, R.
2012-04-01
The importance of adequately modeling credit risk has once again been highlighted in the recent financial crisis. Defaults tend to cluster around times of economic stress due to poor macro-economic conditions, but also by directly triggering each other through contagion. Although credit default swaps have radically altered the dynamics of contagion for more than a decade, models quantifying their impact on systemic risk are still missing. Here, we examine contagion through credit default swaps in a stylized economic network of corporates and financial institutions. We analyse such a system using a stochastic setting, which allows us to exploit limit theorems to exactly solve the contagion dynamics for the entire system. Our analysis shows that, by creating additional contagion channels, CDS can actually lead to greater instability of the entire network in times of economic stress. This is particularly pronounced when CDS are used by banks to expand their loan books (arguing that CDS would offload the additional risks from their balance sheets). Thus, even with complete hedging through CDS, a significant loan book expansion can lead to considerably enhanced probabilities for the occurrence of very large losses and very high default rates in the system. Our approach adds a new dimension to research on credit contagion, and could feed into a rational underpinning of an improved regulatory framework for credit derivatives.
Borane derivatives: A New Class of Superhalogens
NASA Astrophysics Data System (ADS)
Samanta, Devleena; Pathak, Biswarup; Ahuja, Rajeev; Jena, Purusottam
2012-02-01
Halogens have the largest electron affinities of all elements in the periodic table, that of Cl being the highest, namely 3.6 eV. Superhalogens have electron affinities that far exceed that of halogens. Based on density functional theory calculations, we show that the Wade-Mingo's rule, well known for describing the stability of closo-boranes (BnHn^2-), can be used to design a new class of superhalogens by tailoring the size and composition of borane derivatives. These superhalogens do not have to have either a metal or a halogen atom unlike conventional superhalogens. We show this by taking B12H13 and CB11H12 as examples. Also, these superhalogens can be used as building blocks of hyperhalogens of the form M(B12H13)2 and M(CB11H12)2 (M=Li, Na, K, Rb, Cs). This finding opens the door to an untapped source of superhalogens and weakly coordinating anions with potential applications.
Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease
NASA Astrophysics Data System (ADS)
Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua
2014-06-01
Sulfate chitosan derivatives have good solubility and therapeutic effect on the cell model of NAFLD. The aim of this study was to examine the therapeutic effect of sulfate chitosan derivatives on NAFLD. The male Wistar rats were orally fed high fat emulsion and received sulfate chitosan derivatives for 5 weeks to determine the pre-treatment effect of sulfate chitosan derivatives on NAFLD. To evaluate the therapeutic effect of sulfate chitosan derivatives on NAFLD, the rats were orally fed with high concentration emulsion for 5 weeks, followed by sulfate chitosan derivatives for 3 weeks. Histological analysis and biomedical assays showed that sulfate chitosan derivatives can dramatically prevent the development of hepatic steatosis in hepatocyte cells. In animal studies, pre-treatment and treatment with sulfate chitosan derivatives significantly protected against hepatic steatohepatitis induced by high fat diet according to histological analysis. Furthermore, increased TC, ALT, MDA, and LEP in NAFLD were significantly ameliorated by pre-treatment and treatment with sulfate chitosan derivatives. Furthermore, increased TG, AST, and TNF-? in NAFLD were significantly ameliorated by treatment with sulfate chitosan derivatives. Sulfate chitosan derivatives have good pre-treatment and therapeutic effect on NAFLD.
Sung, Li-Ying; Chang, Ching-Chien; Amano, Tomokazu; Lin, Chih-Jen; Amano, Misa; Treaster, Stephen B; Xu, Jie; Chang, Wei-Fang; Nagy, Zsolt Peter; Yang, Xiangzhong; Tian, X Cindy
2010-04-01
Deriving histocompatible embryonic stem (ES) cells by somatic cell nuclear transfer (SCNT) and parthenogenetic activation (PA) requires fresh oocytes, which prevents their applications in humans. Here, we evaluated the efficiency of deriving ES cells from mature metaphase II (MII) and immature metaphase I (MI) vitrified oocytes, by PA or SCNT, in a mouse model. We successfully generated ES cell lines from PA (MII and MI) and SCNT (MII and MI) blastocysts. These cell lines expressed genes and antigens characteristic of pluripotent ES cells and produced full-term pups upon tetraploid embryo complementation. This study established an animal model for efficient generation of patient-specific ES cell lines using cryopreserved oocytes. This is a major step forward in the application of therapeutic cloning and parthenogenetic technology in human regenerative medicine and will serve as an important alternative to the iPS cell technology in countries/regions where these technologies are permitted. PMID:20677934
Bioactive anthraquinone derivatives from the mangrove-derived fungus Stemphylium sp. 33231.
Zhou, Xue-Ming; Zheng, Cai-Juan; Chen, Guang-Ying; Song, Xiao-Ping; Han, Chang-Ri; Li, Gao-Nan; Fu, Yan-Hui; Chen, Wen-Hao; Niu, Zhi-Gang
2014-09-26
Four new anthraquinone derivatives (1-4) and four new alterporriol-type anthranoid dimers (14-17), along with 17 analogues, were isolated from the solid rice fermentation of the fungus Stemphylium sp. 33231 obtained from the mangrove Bruguiera sexangula var. rhynchopetala collected from the South China Sea. Their structures were elucidated using comprehensive spectroscopic methods. The absolute configurations of 1, 3, and 4 were determined by single-crystal X-ray diffraction of their derivatives (1a, 3b, and 4a). The absolute configurations of the chiral 17-19 were determined by comparing their CD spectra with 21. The inhibitory activities of most of the compounds against seven terrestrial pathogenic bacteria and two cancer cell lines were evaluated. PMID:25136754
Acute toxicity of selected crude and refined shale oil derived and petroleum-derived substances
Smith, L.H.; Haschek, W.M.; Witschi, H.
1980-01-01
General information was obtained on the toxicity of selected samples of crude Paraho shale oil and some of its derivatives, some crude petroleums, and 3 refined petroleum products. Five tests were used to determine the acute toxicity of these substances: acute lethality in mice following oral or intraperitoneal administration of a single dose; acute dermal toxicity of a single dose in rats; delayed-type allergic contact hypersensitivity in guinea pigs; primary eye irritation and primary skin irritation of a single dose in rabbits. Histopathologic changes induced in mice following intraperitoneal injection of a single large dose of crude shale oil and two of its hydrotreated derivatives were examined. Studies also have been initiated to examine the tumor inducing potential of selected samples. The test system used was the mouse lung adenoma bioassay. The present report describes our findings and shows that all compounds tested have very low or no acute toxic effects in laboratory animals.
Comparisons between satellite-derived gradient winds and radar-derived winds from the CIRA-86
NASA Technical Reports Server (NTRS)
Manson, A. H.; Meek, C. E.; Fleming, E.; Chandra, S.; Vincent, R. A.
1991-01-01
The zonal and meridional wind contours in the 60-120 km region obtained from satellite radiance data were compared with radar-derived contours of winds obtained from the CIRA-1986 reference atmosphere. It was found that the agreement between the directly observed zonal winds and the zonal mean gradient winds from the reference atmosphere wind model was good, especially below 80 km. However, differences were found in both the Southern and the Northern Hemispheres.
Cognitive effects of cell-derived and synthetically derived A? oligomers.
Reed, Miranda N; Hofmeister, Jacki J; Jungbauer, Lisa; Welzel, Alfred T; Yu, Chunjiang; Sherman, Mathew A; Lesné, Sylvain; LaDu, Mary Jo; Walsh, Dominic M; Ashe, Karen H; Cleary, James P
2011-10-01
Soluble forms of amyloid-? peptide (A?) are a molecular focus in Alzheimer's disease research. Soluble A? dimers (?8 kDa), trimers (?12 kDa), tetramers (?16 kDa) and A?*56 (?56 kDa) have shown biological activity. These A? molecules have been derived from diverse sources, including chemical synthesis, transfected cells, and mouse and human brain, leading to uncertainty about toxicity and potency. Herein, synthetic A? peptide-derived oligomers, cell- and brain-derived low-n oligomers, and A?*56, were injected intracerebroventricularly (icv) into rats assayed under the Alternating Lever Cyclic Ratio (ALCR) cognitive assay. Cognitive deficits were detected at 1.3 ?M of synthetic A? oligomers and at low nanomolar concentrations of cell-secreted A? oligomers. Trimers, from transgenic mouse brain (Tg2576), did not cause cognitive impairment at any dose tested, whereas A?*56 induced concentration-dependent cognitive impairment at 0.9 and 1.3?M. Thus, while multiple forms of A? have cognition impairing activity, there are significant differences in effective concentration and potency. PMID:20031278
Derivation of return stroke parameters from the electric and magnetic field derivatives
Cooray, V. )
1989-01-01
Recently, the transmission line model of the return stroke (Uman and McLain, 1970) has been used by several researchers to infer the characteristics of lightning return strokes. Equations are based on three assumptions: (a) the fields are pure radiation, (b) the maximum return stroke height at time t is much less than the distance to the point of observation, and (c) the ground is perfectly conducting. Any deviation from these assumptions will lead to an error in the inferred properties of the return stroke such as return stroke velocity and return stroke peak current derivative. In this paper the author calculates the electric and magnetic field derivatives from lightning return strokes at different distances over both perfectly conducting and finitely conducting ground, by using the transmission line model. The results will then be compared with those obtained from equations to investigate how far the electric and magnetic field peak derivatives deviate from those given by these equations in the presence of near field components and when the fields have propagated over finitely conducting earth.
Territrem and butyrolactone derivatives from a marine-derived fungus Aspergillus terreus.
Nong, Xu-Hua; Wang, Yi-Fei; Zhang, Xiao-Yong; Zhou, Mu-Ping; Xu, Xin-Ya; Qi, Shu-Hua
2014-12-01
Seventeen lactones including eight territrem derivatives (1-8) and nine butyrolactone derivatives (9-17) were isolated from a marine-derived fungus Aspergillus terreus SCSGAF0162 under solid-state fermentation of rice. Compounds 1-3 and 9-10 were new, and their structures were elucidated by spectroscopic analysis. The acetylcholinesterase inhibitory activity and antiviral activity of compounds 1-17 were evaluated. Among them, compounds 1 and 2 showed strong inhibitory activity against acetylcholinesterase with IC50 values of 4.2 ± 0.6, 4.5 ± 0.6 nM, respectively. This is the first time it has been reported that 3, 6, 10, 12 had evident antiviral activity towards HSV-1 with IC50 values of 16.4 ± 0.6, 6.34 ± 0.4, 21.8 ± 0.8 and 28.9 ± 0.8 ?g·mL-1, respectively. Antifouling bioassay tests showed that compounds 1, 11, 12, 15 had potent antifouling activity with EC50 values of 12.9 ± 0.5, 22.1 ± 0.8, 7.4 ± 0.6, 16.1 ± 0.6 ?g·mL-1 toward barnacle Balanus amphitrite larvae, respectively. PMID:25522319
Environmental applications of chitosan and its derivatives.
Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi
2015-01-01
Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity, hydraulic conductivity, permeability, surface area and sorption capacity. Crosslinked chitosan is an excellent sorbent for trace metals especially because of the high flexibility of its structural stability. Sorption of trace metals by chitosan is selective and independent of the size and hardness of metal ions, or the physical form of chitosan (e.g., film, powder and solution). Both -OH and -NH2 groups in chitosan provide vital binding sites for complexing metal cations. At low pH, -NH3 + groups attract and coagulate negatively charged contaminants such as metal oxyanions, humic acids and dye molecules. Grafting certain functional molecules into the chitin structure improves sorption capacity and selectivity for remediating specific metal ions. For example, introducing sulfur and nitrogen donor ligands to chitosan alters the sorption preference for metals. Low molecular weight chitosan derivatives have been used to remediate metal contaminated soil and sediments. They have also been applied in permeable reactive barriers to remediate metals in soil and groundwater. Both chitosan and modified chitosan have been used to phytoremediate metals; however, the mechanisms by which they assist in mobilizing metals are not yet well understood. In addition, microbes have been used in combination with chitosan to remediate metals (e.g., Cu and Zn) in contaminated soils. Chitosan has also been used to remediate organic contaminants, such as oil-based wastewater, dyes, tannins, humic acids, phenols, bisphenoi-A, p-benzoquinone, organo-phosphorus insecticides, among others. Chitosan has also been utilized to develop optical and electrochemical sensors for in-situ detection of trace contaminants. In sensor technology, naturally-derived chitosan is used primarily as an immobilizing agent that results from its enzyme compatibility, and stabilizing effect on nanoparticles. Contaminant-sensing agents, such as enzymes, microbes and nanoparticles, have been homogeneously immobilized in chitosan gels by using coagulating (e.g., alginate, phosphate) or crosslinking agents (e.g., GA, ECH).
Radiation effects in corundum structure derivatives
NASA Astrophysics Data System (ADS)
Mitchell, J. N.; Devanathan, R.; Yu, N.; Sickafus, K. E.; Wetteland, C. J.; Gopalan, V.; Nastasi, M. A.; McClellan, K. J.
1998-05-01
The radiation response of ?-Al 2O 3 (R3¯c), FeTiO 3 ( Roverline3), MgTiO 3 ( Roverline3), and LiTaO 3 (R3c) was investigated using 200 keV Ar 2+ and 1 MeV Kr + and a combination of Rutherford backscattering spectrometry and transmission electron microscopy. All of these materials have the corundum or a corundum-derivative crystal structure. This family of oxides is of interest due to the simple but significant differences in the structure of the cation sublattices in the different space groups. These materials are also of interest because of their range of melting temperatures, the range of melting temperatures of their oxide components, differences in bonding characteristics, and the complete solid solution between FeTiO 3 and MgTiO 3. Our results show that ?-Al 2O 3 and MgTiO 3 are consistently more radiation tolerant than FeTiO 3 and that LiTaO 3 amorphizes substantially easier than the other three oxides. The greater stability of MgTiO 3 than FeTiO 3 appears to be analogous to the response of Mg-Fe silicates to ion irradiation and high pressure. A characteristic consistent with the radiation tolerance trend of the four oxides studied is a decreasing melting temperature of the component oxides. Thus, the lower stability of Fe-O octahedra in FeTiO 3 and Li-O octahedra in LiTaO 3 may adversely affect the radiation tolerance of these oxides.
Derivation of physically motivated wind speed scales
NASA Astrophysics Data System (ADS)
Dotzek, Nikolai
A class of new wind speed scales is proposed in which the relevant scaling factors are derived from physical quantities like mass flux density, energy density (pressure), or energy flux density. Hence, they are called Energy- or E-scales, and can be applied to wind speeds of any intensity. It is shown that the Mach scale is a special case of an E-scale. Aside from its foundation in physical quantities which allow for a calibration of the scales, the E-scale concept can help to overcome the present plethora of scales for winds in the range from gale to hurricane intensity. A procedure to convert existing data based on the Fujita-scale or other scales (Saffir-Simpson, TORRO, Beaufort) to their corresponding E-scales is outlined. Even for the large US tornado record, the workload of conversion in case of an adoption of the E-scale would in principle remain manageable (if the necessary metadata to do so were available), as primarily the F5 events would have to be re-rated. Compared to damage scales like the "Enhanced Fujita" or EF-scale concept recently implemented in the USA, the E-scales are based on first principles. They can consistently be applied all over the world for the purpose of climatological homogeneity. To account for international variations in building characteristics, one should not adapt wind speed scale thresholds to certain national building characteristics. Instead, one worldwide applicable wind speed scale based on physical principles should rather be complemented by nationally-adapted damage descriptions. The E-scale concept can provide the basis for such a standardised wind speed scale.
Indirubin derivative 6BIO suppresses metastasis.
Braig, Simone; Kressirer, Christine A; Liebl, Johanna; Bischoff, Fabian; Zahler, Stefan; Meijer, Laurent; Vollmar, Angelika M
2013-10-01
While metastasis is the chief cause of cancer mortality, there nonetheless remains a lack of antimetastatic therapies that are clinically available. In this study, we present the indirubin derivative 6-bromo-indirubin-3'-oxime (6BIO) as a promising antimetastatic agent. 6BIO strongly reduced formation of lung metastasis in the well-established 4T1 mouse model of aggressive breast cancer. Several major hallmarks of the metastatic process were affected by subtoxic concentrations of 6BIO, which inhibited adhesion, migration, and invasion of a variety of metastatic cell types in vitro. Mechanistic analyses focused on known targets of 6BIO, which were silenced by this compound. Unexpectedly, RNAi-mediated silencing of glycogen synthase kinase 3? (GSK3?) and phosphoinositide-dependent protein kinase 1 (PDK1), both modulators of cellular metastasis targeted by 6BIO, were not found to affect invasive migration in this study. Instead, the Jak/STAT3 signaling pathway appeared to play a major role through modulation of its downstream migration regulators C-terminal tensin-like protein and matrix metalloproteinase 2. However, PDK1 and GSK3? contributed to the overall response to 6BIO, as silencing of all three pathways resulted in almost complete inhibition of migration, phenocopying the 6BIO response. Taken together, our findings illustrate the antimetastatic activity of 6BIO on the basis of its ability to simultaneously inhibit several kinase cascades involved in metastasis of cancer cells, supporting the concept of "polypharmacology" in developing drugs to attack metastasis, the most deadly aspect of cancer. PMID:23946383
Activated platelet-derived microparticles in thalassaemia.
Pattanapanyasat, Kovit; Gonwong, Siriphan; Chaichompoo, Porntip; Noulsri, Egarit; Lerdwana, Surada; Sukapirom, Kasama; Siritanaratkul, Noppadol; Fucharoen, Suthat
2007-02-01
Thromboembolic complications have been documented in thalassaemia patients. The aggregability of abnormal red blood cells and the high level of membrane-derived microparticles (MPs) stemming from blood cells are thought to be responsible for the associated thrombotic risk. We investigated the number of MPs, their cellular origin and their procoagulant properties in beta-thalassaemia. Fresh whole blood was simultaneously stained for annexin V, cellular antigens and the known density beads. The procoagulant properties of these phosphatidylserine (PS)-bearing MPs were also measured by assessing the platelet factor-3-like activity in the blood. Flow cytometric results showed that splenectomised beta-thalassaemia/HbE patients had significantly higher levels of PS-bearing MPs than non-splenectomised beta-thalassaemia/HbE patients and normal individuals (P < 0.0001). There was a good correlation between PS-bearing MPs and PS-bearing platelets, reflecting the existence of chronic platelet activation in beta-thalassaemia/HbE patients (r(s) = 0.511, P < 0.001). The cellular origin of PS-bearing MPs showed mostly activated-platelet origin with adhesion (CD41a/CD62P/CD36). Moreover, the platelet procoagulant activity was higher in splenectomised beta-thalassaemia/HbE patients when compared with non-splenectomised (P < 0.05) and normal individuals (P < 0.01), and the amount correlated with PS-bearing MPs (rs = 0.560, P < 0.001). These findings suggest that MPs originate from activated platelets with a potential to aggravate thrombotic events when the numbers are excessive, as is commonly seen in splenectomised beta-thalassaemia/HbE patients. PMID:17278261
Supramolecular assemblies of a naturally derived sophorolipid.
Zhou, Shuiqin; Xu, Chang; Wang, Jun; Gao, Wei; Akhverdiyeva, Rena; Shah, Vishal; Gross, Richard
2004-09-14
Acidic sophorolipid (SL) molecules derived from yeasts represent a novel type of asymmetrical bolaamphiphiles due to their unique structural features that include an asymmetrical polar head size (disaccharide vs COOH), a kinked hydrophobic core (cis-9-octadecenoic chain), and a non-amide polar-nonpolar linkage. Light microscopy, small- and wide-angle X-ray scattering, FT-IR spectroscopy, and dynamic laser light scattering were used to investigate the supramolecular structures of the self-assembled aggregates of SL molecules at different pH values. In acidic conditions (pH < 5.5), giant twisted and helical ribbons of 5-11 microm width and several hundreds of micrometers length were observed for the first time. Increase in solution pH values slowed ribbon formation, decreased ribbon yield, and increased the helicity and entanglements of the giant ribbons. An interdigitated lamellar packing model of acidic SL-COOH molecules with a long period of 2.78 nm, stabilized by both the strong hydrophobic association between the cis-9-octadecenoic chains and strong disaccharide-disaccharide hydrogen bonding, is proposed. The neutralization of SL-COOH in water to SL-COONa produced clear solutions with the formation of short-range ordered aggregates. At concentrations below 1.0 mg/mL, the size of self-assembled aggregates increased as the concentration increased. At concentrations above 1.0 mg/mL, narrowly distributed micellar aggregates with a constant hydrodynamic radius (R(h)) of about 100 nm are formed. The large micelles show strong angular dependence with the fast mode appearing at scattering angle theta >/= 60 degrees. PMID:15350054
Fucoxanthin Derivatives: Synthesis and their Chemical Properties.
Komba, Shiro; Kotake-Nara, Eiichi; Machida, Sachiko
2015-09-01
Novel fucoxanthin derivatives that could change the size of mixed micelles were synthesized. The mixed micelles under consideration consist of a bile acid and some additives. To change the affinity against a bile acid, we designed the synthesis of a fucoxanthin-lithocholic acid complex. Lithocholic acid is one of the bile acids. The 3-OH on lithocholic acid was protected by a levulinyl group, and the protected lithocholic acid was selectively coupled via an ester linkage to the 3-OH on fucoxanthin to obtain levulinyl-protected lithocholyl fucoxanthin (LevLF). The levulinyl group was then selectively deprotected using hydrazine to obtain a lithocholyl fucoxanthin (LF). The average sizes of the micelles that contained these compounds (fucoxanthin, LevLF, and LF) with a bile acid (sodium taurocholate) were measured. The LevLF induced larger micelles than fucoxanthin or LF. Interestingly, the addition of 1-oleoyl-rac-glycerol induced a more efficient change in the micelle size. The large micelles grew larger, and the small micelles became smaller. Triple-mixed micelles with LevLF, sodium taurocholate, and 1-oleoyl-rac-glycerol formed the largest micelle with a diameter of 68 nm. On the other hand, triple-mixed micelles using LF, sodium taurocholate, and 1-oleoyl-rac-glycerol made the smallest micelles with diameters as low as 12 nm. We also investigated the hydrolysis of these compounds with enzymes (esterase from porcine liver, lipase from porcine pancreas, and cholesterol esterase from Pseudomonas sp.). The ester linkage between the lithocholic acid and fucoxanthin of LevLF was hydrolyzed with cholesterol esterase. In addition, the intestinal absorption was examined with Caco-2 cells, and no advantageous change in absorption efficiency was observed by chemically modifying the fucoxanthin unless different micelles sizes and increasing hydrophobicity are induced. PMID:26250423
Role of maternally derived immunity in fish.
Swain, P; Nayak, S K
2009-08-01
Maternal immunity is of paramount importance for protection of young ones at early stage of life since the immune factors of an immunocompetent female are transferred transplacentally or through colostrum, milk or yolk to an immunologically naive neonate. Both innate and adaptive type of immunity are transferred of from mother to offspring in fishes. These factors include immunoglobulin (Ig)/antibody, complement factors, lysozymes, protease inhibitors like alpha macroglobulin, different types of lectins and serine proteases like molecules. Among different types of Ig viz. IgM, IgD, IgT/IgZ and IgM-IgZ chimera types, IgM is present in most of the teleostean fishes. In teleosts, IgM either as a reduced/breakdown product or monomeric form is usually transferred to the offsprings. The maternally derived IgM usually persists for a limited duration, exhausts within the completion of yolk absorption process, and completely disappears thereafter during larval stages. Maternal transfer of immunity which provides defense to embryo and larvae depends upon the health as well as the immune status of brood fish. The overall health status of brood fish can affect breeding performances, quality seed production and protection of offsprings. However, factors such as age, maturation, reproductive behaviour and nutrition (micro and macro-nutrients) may affect the immunity in brood fishes. Besides these, seasonal changes such as photoperiods, temperature, adverse environmental conditions, and stress conditions like handling, crowding, and water pollution/contamination can also affect the immunity of brood fishes. The maintenance of the brood stock immunity at high level during vitellogenesis and oogenesis, is utmost important for reducing mortalities at larval/post larval stages through maximum/optimum transfer of maternal immunity. Brood stock immunization prior to breeding as well as selective breeding among the disease resistant families might be the ideal criteria for producing quality seed. PMID:19442742
Tachometers Derived From a Brushless DC Motor
NASA Technical Reports Server (NTRS)
Howard, David E.; Smith, Dennis A.
2007-01-01
The upper part of the figure illustrates the major functional blocks of a direction-sensitive analog tachometer circuit based on the use of an unexcited two-phase brushless dc motor as a rotation transducer. The primary advantages of this circuit over many older tachometer circuits include the following: Its output inherently varies linearly with the rate of rotation of the shaft. Unlike some tachometer circuits that rely on differentiation of voltages with respect to time, this circuit relies on integration, which results in signals that are less noisy. There is no need for an additional shaft-angle sensor, nor is there any need to supply electrical excitation to a shaft-angle sensor. There is no need for mechanical brushes (which tend to act as sources of electrical noise). The underlying concept and electrical design are relatively simple. This circuit processes the back-electromagnetic force (back-emf) outputs of the two motor phases into a voltage directly proportional to the instantaneous rate (sign magnitude) of rotation of the shaft. The processing in this circuit effects a straightforward combination of mathematical operations leading to a final operation based on the well-known trigonometric identity (sin x)2 + (cos x)2 = 1 for any value of x. The principle of operation of this circuit is closely related to that of the tachometer circuit described in Tachometer Derived From Brushless Shaft-Angle Resolver (MFS-28845), NASA Tech Briefs, Vol. 19, No. 3 (March 1995), page 39. However, the present circuit is simpler in some respects because there is no need for sinusoidal excitation of shaftangle- resolver windings.
Functionalized bacterial cellulose derivatives and nanocomposites.
Hu, Weili; Chen, Shiyan; Yang, Jingxuan; Li, Zhe; Wang, Huaping
2014-01-30
Bacterial cellulose (BC) is a fascinating and renewable natural nanomaterial characterized by favorable properties such as remarkable mechanical properties, porosity, water absorbency, moldability, biodegradability and excellent biological affinity. Intensive research and exploration in the past few decades on BC nanomaterials mainly focused on their biosynthetic process to achieve the low-cost preparation and application in medical, food, advanced acoustic diaphragms, and other fields. These investigations have led to the emergence of more diverse potential applications exploiting the functionality of BC nanomaterials. This review gives a summary of construction strategies including biosynthetic modification, chemical modification, and different in situ and ex situ patterns of functionalization for the preparation of advanced BC-based functional nanomaterials. The major studies being directed toward elaborate designs of highly functionalized material systems for many-faceted prospective applications. Simple biosynthetic or chemical modification on BC surface can improve its compatibility with different matrix and expand its utilization in nano-related applications. Moreover, based on the construction strategies of functional nanomaterial system, different guest substrates including small molecules, inorganic nanoparticles or nanowires, and polymers can be incorporated onto the surfaces of BC nanofibers to prepare various functional nanocomposites with outstanding properties, or significantly improved physicochemical, catalytic, optoelectronic, as well as magnetic properties. We focus on the preparation methods, formation mechanisms, and unique performances of the different BC derivatives or BC-based nanocomposites. The special applications of the advanced BC-based functional nanomaterials, such as sensors, photocatalytic nanomaterials, optoelectronic devices, and magnetically responsive membranes are also critically and comprehensively reviewed. PMID:24299873
Local detailed balance: a microscopic derivation
NASA Astrophysics Data System (ADS)
Bauer, M.; Cornu, F.
2015-01-01
Thermal contact is the archetype of non-equilibrium processes driven by constant non-equilibrium constraints when the latter are enforced by reservoirs exchanging conserved microscopic quantities. At a mesoscopic scale only the energies of the macroscopic bodies are accessible together with the configurations of the contact system. We consider a class of models where the contact system, as well as macroscopic bodies, have a finite number of possible configurations. The global system, with only discrete degrees of freedom, has no microscopic Hamiltonian dynamics, but it is shown that, if the microscopic dynamics is assumed to be deterministic and ergodic and to conserve energy according to some specific pattern, and if the mesoscopic evolution of the global system is approximated by a Markov process as closely as possible, then the mesoscopic transition rates obey three constraints. In the limit where macroscopic bodies can be considered as reservoirs at thermodynamic equilibrium (but with different intensive parameters), the mesoscopic transition rates turn into transition rates for the contact system and the third constraint becomes local detailed balance; the latter is generically expressed in terms of the microscopic exchange entropy variation, namely the opposite of the variation of the thermodynamic entropy of the reservoir involved in a given microscopic jump of the contact system configuration. For a finite-time evolution after contact has been switched on, we derive a fluctuation relation for the joint probability of the heat amounts received from the various reservoirs. The generalization to systems exchanging energy, volume and matter with several reservoirs, with a possible conservative external force acting on the contact system, is given explicitly.
Nanoscale Reinforced, Polymer Derived Ceramic Matrix Coatings
Rajendra Bordia
2009-07-31
The goal of this project was to explore and develop a novel class of nanoscale reinforced ceramic coatings for high temperature (600-1000 C) corrosion protection of metallic components in a coal-fired environment. It was focused on developing coatings that are easy to process and low cost. The approach was to use high-yield preceramic polymers loaded with nano-size fillers. The complex interplay of the particles in the polymer, their role in controlling shrinkage and phase evolution during thermal treatment, resulting densification and microstructural evolution, mechanical properties and effectiveness as corrosion protection coatings were investigated. Fe-and Ni-based alloys currently used in coal-fired environments do not possess the requisite corrosion and oxidation resistance for next generation of advanced power systems. One example of this is the power plants that use ultra supercritical steam as the working fluid. The increase in thermal efficiency of the plant and decrease in pollutant emissions are only possible by changing the properties of steam from supercritical to ultra supercritical. However, the conditions, 650 C and 34.5 MPa, are too severe and result in higher rate of corrosion due to higher metal temperatures. Coating the metallic components with ceramics that are resistant to corrosion, oxidation and erosion, is an economical and immediate solution to this problem. Good high temperature corrosion protection ceramic coatings for metallic structures must have a set of properties that are difficult to achieve using established processing techniques. The required properties include ease of coating complex shapes, low processing temperatures, thermal expansion match with metallic structures and good mechanical and chemical properties. Nanoscale reinforced composite coatings in which the matrix is derived from preceramic polymers have the potential to meet these requirements. The research was focused on developing suitable material systems and processing techniques for these coatings. In addition, we investigated the effect of microstructure on the mechanical properties and oxidation protection ability of the coatings. Coatings were developed to provide oxidation protection to both ferritic and austentic alloys and Ni-based alloys. The coatings that we developed are based on low viscosity pre-ceramic polymers. Thus they can be easily applied to any shape by using a variety of techniques including dip-coating, spray-coating and painting. The polymers are loaded with a variety of nanoparticles. The nanoparticles have two primary roles: control of the final composition and phases (and hence the properties); and control of the shrinkage during thermal decomposition of the polymer. Thus the selection of the nanoparticles was the most critical aspect of this project. Based on the results of the processing studies, the performance of selected coatings in oxidizing conditions (both static and cyclic) was investigated.
Rigorous derivation of electromagnetic self-force
Gralla, Samuel E.; Harte, Abraham I.; Wald, Robert M.
2009-07-15
During the past century, there has been considerable discussion and analysis of the motion of a point charge in an external electromagnetic field in special relativity, taking into account 'self-force' effects due to the particle's own electromagnetic field. We analyze the issue of 'particle motion' in classical electromagnetism in a rigorous and systematic way by considering a one-parameter family of solutions to the coupled Maxwell and matter equations corresponding to having a body whose charge-current density J{sup a}({lambda}) and stress-energy tensor T{sub ab}({lambda}) scale to zero size in an asymptotically self-similar manner about a worldline {gamma} as {lambda}{yields}0. In this limit, the charge, q, and total mass, m, of the body go to zero, and q/m goes to a well-defined limit. The Maxwell field F{sub ab}({lambda}) is assumed to be the retarded solution associated with J{sup a}({lambda}) plus a homogeneous solution (the 'external field') that varies smoothly with {lambda}. We prove that the worldline {gamma} must be a solution to the Lorentz force equations of motion in the external field F{sub ab}({lambda}=0). We then obtain self-force, dipole forces, and spin force as first-order perturbative corrections to the center-of-mass motion of the body. We believe that this is the first rigorous derivation of the complete first-order correction to Lorentz force motion. We also address the issue of obtaining a self-consistent perturbative equation of motion associated with our perturbative result, and argue that the self-force equations of motion that have previously been written down in conjunction with the 'reduction of order' procedure should provide accurate equations of motion for a sufficiently small charged body with negligible dipole moments and spin. (There is no corresponding justification for the non-reduced-order equations.) We restrict consideration in this paper to classical electrodynamics in flat spacetime, but there should be no difficulty in extending our results to the motion of a charged body in an arbitrary globally hyperbolic curved spacetime.
Rigorous derivation of electromagnetic self-force
NASA Astrophysics Data System (ADS)
Gralla, Samuel E.; Harte, Abraham I.; Wald, Robert M.
2009-07-01
During the past century, there has been considerable discussion and analysis of the motion of a point charge in an external electromagnetic field in special relativity, taking into account “self-force” effects due to the particle’s own electromagnetic field. We analyze the issue of “particle motion” in classical electromagnetism in a rigorous and systematic way by considering a one-parameter family of solutions to the coupled Maxwell and matter equations corresponding to having a body whose charge-current density Ja(?) and stress-energy tensor Tab(?) scale to zero size in an asymptotically self-similar manner about a worldline ? as ??0. In this limit, the charge, q, and total mass, m, of the body go to zero, and q/m goes to a well-defined limit. The Maxwell field Fab(?) is assumed to be the retarded solution associated with Ja(?) plus a homogeneous solution (the “external field”) that varies smoothly with ?. We prove that the worldline ? must be a solution to the Lorentz force equations of motion in the external field Fab(?=0). We then obtain self-force, dipole forces, and spin force as first-order perturbative corrections to the center-of-mass motion of the body. We believe that this is the first rigorous derivation of the complete first-order correction to Lorentz force motion. We also address the issue of obtaining a self-consistent perturbative equation of motion associated with our perturbative result, and argue that the self-force equations of motion that have previously been written down in conjunction with the “reduction of order” procedure should provide accurate equations of motion for a sufficiently small charged body with negligible dipole moments and spin. (There is no corresponding justification for the non-reduced-order equations.) We restrict consideration in this paper to classical electrodynamics in flat spacetime, but there should be no difficulty in extending our results to the motion of a charged body in an arbitrary globally hyperbolic curved spacetime.
The thiazole derivative CPTH6 impairs autophagy
Ragazzoni, Y; Desideri, M; Gabellini, C; De Luca, T; Carradori, S; Secci, D; Nescatelli, R; Candiloro, A; Condello, M; Meschini, S; Del Bufalo, D; Trisciuoglio, D
2013-01-01
We have previously demonstrated that the thiazole derivative 3-methylcyclopentylidene-[4-(4?-chlorophenyl)thiazol-2-yl]hydrazone (CPTH6) induces apoptosis and cell cycle arrest in human leukemia cells. The aim of this study was to evaluate whether CPTH6 is able to affect autophagy. By using several human tumor cell lines with different origins we demonstrated that CPTH6 treatment induced, in a dose-dependent manner, a significant increase in autophagic features, as imaged by electron microscopy, immunoblotting analysis of membrane-bound form of microtubule-associated protein 1 light chain 3 (LC3B-II) levels and by appearance of typical LC3B-II-associated autophagosomal puncta. To gain insights into the molecular mechanisms of elevated markers of autophagy induced by CPTH6 treatment, we silenced the expression of several proteins acting at different steps of autophagy. We found that the effect of CPTH6 on autophagy developed through a noncanonical mechanism that did not require beclin-1-dependent nucleation, but involved Atg-7-mediated elongation of autophagosomal membranes. Strikingly, a combined treatment of CPTH6 with late-stage autophagy inhibitors, such as chloroquine and bafilomycin A1, demonstrates that under basal condition CPTH6 reduces autophagosome turnover through an impairment of their degradation pathway, rather than enhancing autophagosome formation, as confirmed by immunofluorescence experiments. According to these results, CPTH6-induced enhancement of autophagy substrate p62 and NBR1 protein levels confirms a blockage of autophagic cargo degradation. In addition, CPTH6 inhibited autophagosome maturation and compounds having high structural similarities with CPTH6 produced similar effects on the autophagic pathway. Finally, the evidence that CPTH6 treatment decreased ?-tubulin acetylation and failed to increase autophagic markers in cells in which acetyltransferase ATAT1 expression was silenced indicates a possible role of ?-tubulin acetylation in CPTH6-induced alteration in autophagy. Overall, CPTH6 could be a valuable agent for the treatment of cancer and should be further studied as a possible antineoplastic agent. PMID:23470531
Derivation of Practical Kedem - Katchalsky Equations for Membrane Substance Transport
NASA Astrophysics Data System (ADS)
Jarzy?ska, M.; Pietruszka, M.
2008-09-01
The following paper includes a derivation of practical Kedem-Katchalsky (K-K) equations for the volume flow J? and the solute flow Js for non-electrolytes. This derivation makes the equations clearer and consequently their interpretation also becomes easier. The equations have been derived on the basis of the analysis of the membrane transport generated by simultaneous action of two thermodynamic stimuli: the hydrostatic pressure difference ?p and the osmotic pressure difference ??. Furthermore, the derivation of the solute permeability coefficient ?, which results from K-K equations, is also presented in this paper. The formulas for coefficients characterizing membrane permeability, ?d and ?k, as well as their derivation and physical interpretation are also presented below. Finally, a formula for the membrane coefficient LD, which represents a diffusional mobility, is derived.
Biological activities of water-soluble fullerene derivatives
NASA Astrophysics Data System (ADS)
Nakamura, S.; Mashino, T.
2009-04-01
Three types of water-soluble fullerene derivatives were synthesized and their biological activities were investigated. C60-dimalonic acid, an anionic fullerene derivative, showed antioxidant activity such as quenching of superoxide and relief from growth inhibition of E. coli by paraquat. C60-bis(7V,7V-dimethylpyrrolidinium iodide), a cationic fullerene derivative, has antibacterial activity and antiproliferative effect on cancer cell lines. The mechanism is suggested to be respiratory chain inhibition by reactive oxygen species produced by the cationic fullerene derivative. Proline-type fullerene derivatives showed strong inhibition activities on HIV-reverse transcriptase. The IC50 values were remarkably lower than nevirapine, a clinically used anti-HIV drug. Fullerene derivatives have a big potential for a new type of lead compound to be used as medicine.
Derivation of Formulations 1 and 1A of Farassat
NASA Technical Reports Server (NTRS)
Farassat, F.
2007-01-01
Formulations 1 and 1A are the solutions of the Ffowcs Williams-Hawkings (FW-H) equation with surface sources only when the surface moves at subsonic speed. Both formulations have been successfully used for helicopter rotor and propeller noise prediction for many years although we now recommend using Formulation 1A for this purpose. Formulation 1 has an observer time derivative that is taken numerically, and thus, increasing execution time on a computer and reducing the accuracy of the results. After some discussion of the Green's function of the wave equation, we derive Formulation 1 which is the basis of deriving Formulation 1A. We will then show how to take this observer time derivative analytically to get Formulation 1A. We give here the most detailed derivation of these formulations. Once you see the whole derivation, you will ask yourself why you did not do it yourself!
Synthesis and biological evaluation of caracasine acid derivatives.
Chávez, Katiuska; Compagnone, Reinaldo S; Álvarez, Annamil; Figarella, Katherine; Galindo-Castro, Iván; Marsiccobetre, Sabrina; Triviño, Jennifer; Arocha, Irina; Taddei, Antonieta; Orsini, Giovannina; Tillett, Stephen; Suárez, Alírica I
2015-07-01
A series of caracasine acid (1) derivatives were synthesized and evaluated for their in vitro cytotoxicity on human cancer-derived cell lines MCF-7 and PC-3, as well as for other activities such as antibacterial, antileishmanial and antitrypanosomal activity. Compound 1 was more effective than any of its derivatives against tested human cancer cell lines. PC-3 cells were more sensitive than MCF-7 to all compounds, particularly the methyl ester (2), the amide (9) and the epoxide (10). The evaluation of antiparasitic activity revealed that ester derivatives (2-8) and the amide derivative (9) were the most effective antileishmanial and antitrypanosomal compounds, even though their effect on Trypanosoma cruzi was modest. Finally, compound 1 and the derivatives evidenced a broad spectrum of antibacterial activity, as assayed against Gram-positive and Gram-negative bacteria. PMID:25891984
Deriving the tropospheric integrated water vapor from tipping curve-derived opacity near 22 GHz
NASA Astrophysics Data System (ADS)
Deuber, Beat; Morland, June; Martin, Lorenz; KäMpfer, Niklaus
2005-10-01
In this study we present a simple relation between the tropospheric opacity ? near 22.235 GHz and the integrated water vapor (IWV) content of the troposphere. The opacity is measured at Bern, Switzerland, by the radiometer Middle Atmospheric Water Vapour Radiometer (MIAWARA), designed for middle atmospheric water vapor profile measurements. In contrast to typical radiometers for tropospheric monitoring, this middle atmospheric water vapor radiometer only measures in the vicinity of the 22.235 GHz water vapor line with a bandwidth of 1 GHz. With this study we show that it is even possible to derive the integrated tropospheric water vapor (IWV) content of the atmosphere using this limited frequency range if the liquid water content of the atmosphere is negligible. IWV measurements of the tropospheric monitoring instruments Tropospheric Water Vapour Radiometer (TROWARA, two-channel radiometer), All-Sky Multi Wavelength Radiometer (ASMUWARA, multichannel radiometer), and GPS, which are operated next to MIAWARA, are used to derive a linear relation between the opacity and the water vapor content of the troposphere. In a second step, the mean tropospheric temperature is taken into account and a slight improvement of the linear relation is achieved. All instruments involved in this study are contributing to the Studies in Atmospheric Radiative Transfer and Water Vapour Effects (STARTWAVE) project of the Climate program of the National Competence Center in Research. The MIAWARA measurements in the subarctic winter in northern Finland during the Lapbiat Upper Tropospheric Lower Stratospheric Water Vapor Validation Project (LAUTLOS/WAVVAP) campaign in 2004 are compared to radiosonde measurements by the Finnish Meteorological Institute using the same algorithm that was derived for Bern. The agreement of MIAWARA IWV and radiosonde IWV is of the same order as for Bern. Finally, Payerne radiosonde measurements and model simulation using the Atmospheric Radiative Transfer Simulator (ARTS) software and the continuum absorption models of Rosenkranz (1998) and Liebe (MPM87/MPM93) confirm the derived opacity-IWV relation. This study shows that the integrated water vapor content of the troposphere can be measured by a radiometer operating near the 22.235 GHz water vapor line using a bandwidth of 1 GHz, if the liquid water content of the atmosphere is negligible.
Status report on the NCSL Intrinsic/Derived Standards Committee
Pettit, R.B.
1994-05-01
The history and present status of the NCSL intrinsic/Derived Standards Committee is presented, including a review of the current published Recommended Intrinsic/Derived Standard Practices (RISPs) and the four Working Groups that are in the process of developing new RISPs. One of the documents under development is a Reference Catalogue that documents important information associated with over forty intrinsic/derived standards. The generic information on each standard in the Catalogue, as well as its Table of contents, are presented.
Massive Gravity from Higher Derivative Gravity with Boundary Conditions
Minjoon Park; Lorenzo Sorbo
2012-10-29
With an appropriate choice of parameters, a higher derivative theory of gravity can describe a normal massive sector and a ghost massless sector. We show that, when defined on an asymptotically de Sitter spacetime with Dirichlet boundary conditions, such a higher derivative gravity can provide a framework for a unitary theory of massive gravity in four spacetime dimensions. The resulting theory is free not only of higher derivative ghosts but also of the Boulware-Deser mode.
A Systematic Derivation of the Riemannian Barrett-Crane Intertwiner
Suresh K Maran
2006-04-18
The Barrett-Crane intertwiner for the Riemannian general relativity is systematically derived by solving the quantum Barrett-Crane constraints corresponding to a tetrahedron (except for the non-degeneracy condition). It was shown by Reisenberger that the Barrett-Crane intertwiner is the unique solution. The systematic derivation can be considered as an alternative proof of the uniqueness. The new element in the derivation is the rigorous imposition of the cross-simplicity constraint.
Criticality safety benchmark experiments derived from ANL ZPR assemblies.
Schaefer, R. W.; Lell, R. M.; McKnight, R. D.
2003-09-01
Numerous criticality safety benchmarks have been, and continue to be, developed from experiments performed on Argonne National Laboratory's plate-type fast critical assemblies. The nature and scope of assemblies suitable for deriving these benchmarks are discussed. The benchmark derivation process, including full treatment of all significant uncertainties, is explained. Calculational results are presented that support the small uncertainty assigned to the key derivation step in which complex geometric detail is removed.
Holographic entanglement entropy for the most general higher derivative gravity
NASA Astrophysics Data System (ADS)
Miao, Rong-Xin; Guo, Wu-zhong
2015-08-01
The holographic entanglement entropy for the most general higher derivative gravity is investigated. We find a new type of Wald entropy, which appears on entangling surface without the rotational symmetry and reduces to usual Wald entropy on Killing horizon. Furthermore, we obtain a formal formula of HEE for the most general higher derivative gravity and work it out exactly for some squashed cones. As an important application, we derive HEE for gravitational action with one derivative of the curvature when the extrinsic curvature vanishes. We also study some toy models with non-zero extrinsic curvature. We prove that our formula yields the correct universal term of entanglement entropy for 4d CFTs. Furthermore, we solve the puzzle raised by Hung, Myers and Smolkin that the logarithmic term of entanglement entropy derived from Weyl anomaly of CFTs does not match the holographic result even if the extrinsic curvature vanishes. We find that such mismatch comes from the `anomaly of entropy' of the derivative of curvature. After considering such contributions carefully, we resolve the puzzle successfully. In general, we need to fix the splitting problem for the conical metrics in order to derive the holographic entanglement entropy. We find that, at least for Einstein gravity, the splitting problem can be fixed by using equations of motion. How to derive the splittings for higher derivative gravity is a non-trivial and open question. For simplicity, we ignore the splitting problem in this paper and find that it does not affect our main results.
Regulatory considerations for biotechnology-derived animals in Canada.
Kochhar, H P S; Adlakha-Hutcheon, G; Evans, B R
2005-04-01
Regulatory initiatives relating to biotechnology-derived livestock have focused on animal health, environmental impact, and the general concept of the safety of the food and by-products derived from such animals. Existing regulatory frameworks have been stretched to accommodate these emerging concerns. Public concerns and the expectations of society mean that the regulatory infrastructure is subject to a high level of scrutiny and that regulations are expected to maintain a clear level of confidence, transparency and effectiveness. A sound regulatory regime should be 'neutral', neither 'facilitating' nor 'restricting' the approval of products or by-products derived from biotechnology-derived animals. PMID:16110882
Synthesis and Antimicrobial Activities of 3-Methyl-?-Carboline Derivatives.
Zhang, Jiwen; Li, Longbo; Dan, Wenjia; Li, Jian; Zhang, Qianliang; Bai, Hongjin; Wang, Junru
2015-06-01
The ?-carboline alkaloids possess a diverse range of important biochemical effects and pharmacological properties. Sixteen 3-methyl-?-carboline derivatives were synthesized from indole formaldehyde and nitroethane via the Henry reaction, LAH/THF reduction, the Pictet-Spengler reaction and Pd/C/xylene oxidation, including four 1-substituted and twelve 9-substituted 3-methyl- ?-carboline derivatives. The structures of all the derivatives were confirmed by 1H NMR, 13C NMR and ESI-MS. Most of these 3-methyl-?-carboline derivatives showed some antibacterial activity. PMID:26197512
Chalcone derivatives as potential antifungal agents: Synthesis, and antifungal activity
Gupta, Deepa; Jain, D. K.
2015-01-01
Much research has been carried out with the aim to discover the therapeutic values of chalcone derivatives. Chalcones possess wide range of pharmacological activity such as antibacterial, antimalarial, antiprotozoal, antitubercular, anticancer, and antifungal agents etc. The presence of reactive ?,?-unsaturated keto group in chalcones is found to be responsible for their biological activity. The rapid developments of resistance to antifungal agents, led to design, and synthesize the new antifungal agents. The derivatives of chalcones were prepared using Claisen–Schmidt condensation scheme with appropriate tetralone and aldehyde derivatives. Ten derivatives were synthesized and were biologically screened for antifungal activity. The newly synthesized derivatives of chalcone showed antifungal activity against fungal species, Microsporum gypseum. The results so obtained were superior or comparable to ketoconazole. It was observed that none of the compounds tested showed positive results for fungi Candida albicans nor against fungi Aspergillus niger. Chalcone derivatives showed inhibitory effect against M. gypseum species of fungus. It was found that among the chalcone derivatives so synthesized, two of them, that is, 4-chloro derivative, and unsubstituted derivative of chalcone showed antifungal activity superior to ketoconazole. Thus, these can be the potential new molecule as antifungal agent.
Ferroquine and its derivatives: New generation of antimalarial agents.
Wani, Waseem A; Jameel, Ehtesham; Baig, Umair; Mumtazuddin, Syed; Hun, Lee Ting
2015-08-28
Malaria has been teasing human populations from a long time. Presently, several classes of antimalarial drugs are available in market, but the issues of toxicity, lower efficacy and the resistance by malarial parasites have decreased their overall therapeutic indices. Thus, the search for new promising antimalarials continues, however, the battle against malaria is far from over. Ferroquine is a derivative of chloroquine with antimalarial properties. It is the most successful of the chloroquine derivatives. Not only ferroquine, but also its derivatives have shown promising potential as antimalarials of clinical interest. Presently, much research is dedicated to the development of ferroquine derivatives as safe alternatives to antimalarial chemotherapy. The present article describes the structural, chemical and biological features of ferroquine. Several classes of ferroquine derivatives including hydroxyferroquines, trioxaferroquines, chloroquine-bridged ferrocenophanes, thiosemicarbazone derivatives, ferrocene dual conjugates, 4-N-substituted derivatives, and others have been discussed. Besides, the mechanism of action of ferroquine has been discussed. A careful observation has been made into pharmacologically significant ferroquine derivatives with better or equal therapeutic effects to that of chloroquine and ferroquine. A brief discussion of the toxicities of ferroquine derivatives has been made. Finally, efforts have been made to discuss the current challenges and future perspectives of ferroquine-based antimalarial drug development. PMID:26188909
Single Molecule Conductance of Oligothiophene Derivatives
NASA Astrophysics Data System (ADS)
Dell, Emma J.
This thesis studies the electronic properties of small organic molecules based on the thiophene motif. If we are to build next-generation devices, advanced materials must be designed which possess requisite electronic functionality. Molecules present attractive candidates for these ad- vanced materials since nanoscale devices are particularly sought after. However, selecting a molecule that is suited to a certain electronic function remains a challenge, and characterization of electronic behavior is therefore critical. Single molecule conductance measurements are a powerful tool to determine properties on the nanoscale and, as such, can be used to investigate novel building blocks that may fulfill the design requirements of next-generation devices. Combining these conductance results with strategic chemical synthesis allows for the development of new families of molecules that show attractive properties for future electronic devices. Since thiophene rings are the fruitflies of organic semiconductors on the bulk scale, they present an intriguing starting point for building functional materials on the nanoscale, and therefore form the structural basis of all molecules studied herein. First, the single-molecule conductance of a family of bithiophene derivatives was measured. A broad distribution in the single-molecule conductance of bithiophene was found compared with that of a biphenyl. This increased breadth in the conductance distribution was shown to be explained by the difference in 5-fold symmetry of thiophene rings as compared to the 6-fold symmetry of benzene rings. The reduced symmetry of thiophene rings results in a restriction on the torsion angle space available to these molecules when bound between two metal electrodes in a junction, causing each molecular junction to sample a different set of conformers in the conductance measurements. By contrast, the rotations of biphenyl are essentially unimpeded by junction binding, allowing each molecular junction to sample similar conformers. This work demonstrates that the conductance of bithiophene displays a strong dependence on the conformational fluctuations accessible within a given junction configuration, and that the symmetry of such small molecules can significantly influence their conductance behavior. Next, the single-molecule conductance of a family of oligothiophenes comprising one to six thiophene units was measured. An anomalous behavior was found: the peak of the conductance histogram distribution did not follow a clear exponential decay with increasing number of thiophene units in the chain. The electronic properties of the materials were characterized by optical spectroscopy and electrochemistry to gain an understanding of the factors affecting the conductance of these molecules. Different conformers in the junction were postulated to be a contributing factor to the anomalous trend in the observed conductance as a function of molecule length. Then, the electronic properties of the thiophene-1,1-dioxide unit were investigated. These motifs have become synthetically accessible in the last decade, due to Rozen's unprecedentedly potent oxidizing reagent - HOF?CH 3CN - which has been shown to be powerful yet selective enough to oxidize thiophenes in various environments. The resulting thiophene-1,1-dioxides show great promise for electronic devices. The oxidation chemistry of thiophenes was expanded and tuning of the frontier energy levels was demonstrated through combining electron poor and electron rich units. Finally, charge carriers in single-molecule junctions were shown to be tunable within a family of molecules containing these thiophene-1,1-dioxide (TDO) building blocks. Oligomers of TDO were designed in order to increase electron affinity, maintain delocalized frontier orbitals, while significantly decreasing the transport gap. Through thermopower measurements, the dominant charge carriers were shown to change from holes to electrons as the number of TDO units was increased. This resulted in a unique system in which the charge carrier depends on ba
Wang, Jun-Feng; Qin, Xiaochu; Xu, Fu-Quan; Zhang, Tianyu; Liao, Shengrong; Lin, Xiuping; Yang, Bin; Liu, Juan; Wang, Lishu; Tu, Zhengchao; Liu, Yonghong
2015-09-01
Fifteen compounds, including two tetramic acid derivatives, penicillenol A1 (1) and penicillenol A2 (2), six polyphenols containing both phenolic bisabolane sesquiterpenoid and diphenyl ether units, expansols A-F (3-8), together with six phenolic bisabolane sesquiterpenoids (9-14) and diorcinol (15), were isolated from the fermentation broth of the marine-derived fungus ZSDS1-F11 isolated from the sponge Phakellia fusca Thiele collected in the Yongxing island of Xisha. Their structures were elucidated mainly by using extensive NMR spectroscopic and mass spectrometric analyses. Compounds 3-5, 7 and 8 showed potent COX-1 inhibitory activity with IC50 values of 5.3, 16.2, 30.2, 41.0 and 56.8 ?M, respectively. Meanwhile, compounds 3-8 showed potent COX-2 inhibitory activity with IC50 values of 3.1, 5.6, 3.0, 5.1, 3.2 and 3.7 ?M, respectively. In addition, compound 1 exhibited antituberculosis activity with 96.1% inhibition at concentration of 10 ?M. PMID:25573692
NASA Astrophysics Data System (ADS)
Lazi?, Vedrana; Jurkovi?, Mihaela; Jedna?ak, Tomislav; Hrenar, Tomica; Vukovi?, Jelena Parlov; Novak, Predrag
2015-01-01
The structure and hydrogen bonding in solution of acetylacetone and benzoylacetone derived enaminone derivatives, 1a-1d and 2a-2d, have been studied by a combination of experimental (NMR and UV spectroscopies) and theoretical (PM6 and DFT) methods. It has been shown that all studied compounds predominantly existed in the localised keto-amine tautomeric form in solution as found also in the solid state. Significant line-broadening and down-field chemical shifts of NH and OH protons have strongly indicated that both groups formed hydrogen bonds, which has further been supported by quantum chemical calculations. Temperature and concentration dependent NMR measurements have pointed towards the fact that NH protons are engaged in strong intramolecular hydrogen bonds of the NH⋯Odbnd C type in both solvents. On the other hand, OH protons are involved in weaker intermolecular hydrogen bonding with solvent molecules in DMSO, while in chloroform intermolecular interactions between two molecules dominate. The results presented in this paper can be used for better understanding and further exploiting properties these ligands possess, especially their bioactivity.
Zengerle, Michael; Brandhuber, Florian; Schneider, Christian; Worek, Franz; Reiter, Georg
2011-01-01
Summary The potential of appropriately substituted cyclodextrins to act as scavengers for neurotoxic organophosphonates under physiological conditions was evaluated. To this end, a series of derivatives containing substituents with an aldoxime or a ketoxime moiety along the narrow opening of the ?-cyclodextrin cavity was synthesized, and the ability of these compounds to reduce the inhibitory effect of the neurotoxic organophosphonate cyclosarin on its key target, acetylcholinesterase, was assessed in vitro. All compounds exhibited a larger effect than native ?-cyclodextrin, and characteristic differences were noted. These differences in activity were correlated with the structural and electronic parameters of the substituents. In addition, the relatively strong effect of the cyclodextrin derivatives on cyclosarin degradation and, in particular, the observed enantioselectivity are good indications that noncovalent interactions between the cyclodextrin ring and the substrate, presumably involving the inclusion of the cyclohexyl moiety of cyclosarin into the cyclodextrin cavity, contribute to the mode of action. Among the nine compounds investigated, one exhibited remarkable activity, completely preventing acetylcholinesterase inhibition by the (?)-enantiomer of cyclosarin within seconds under the conditions of the assay. Thus, these investigations demonstrate that decoration of cyclodextrins with appropriate substituents represents a promising approach for the development of scavengers able to detoxify highly toxic nerve agents. PMID:22238531
Diketopiperazine derivatives from the marine-derived actinomycete Streptomyces sp. FXJ7.328.
Wang, Pei; Xi, Lijun; Liu, Peipei; Wang, Yi; Wang, Wei; Huang, Ying; Zhu, Weiming
2013-04-01
Five new diketopiperazine derivatives, (3Z,6E)-1-N-methyl-3-benzylidene-6-(2S-methyl-3-hydroxypropylidene)piperazine-2,5-dione (1), (3Z,6E)-1-N-methyl-3-benzylidene-6-(2R-methyl-3-hydroxypropylidene)piperazine-2,5-dione (2), (3Z,6Z)-3- (4-hydroxybenzylidene)-6-isobutylidenepiperazine-2,5-dione (3), (3Z,6Z)-3-((1H-imidazol-5-yl)-methylene)-6-isobutylidenepiperazine-2,5-dione (4), and (3Z,6S)-3-benzylidene-6-(2S-but-2-yl)piperazine-2,5-dione (5), were isolated from the marine-derived actinomycete Streptomyces sp. FXJ7.328. The structures of 1-5 were determined by spectroscopic analysis, CD exciton chirality, the modified Mosher's, Marfey's and the C3 Marfey's methods. Compound 3 showed modest antivirus activity against influenza A (H1N1) virus with an IC50 value of 41.5 ± 4.5 ?M. In addition, compound 6 and 7 displayed potent anti-H1N1 activity with IC50 value of 28.9 ± 2.2 and 6.8 ± 1.5 ?M, respectively. Due to the lack of corresponding data in the literature, the 13C NMR data of (3Z,6S)-3-benzylidene-6-isobutylpiperazine-2,5-dione (6) were also reported here for the first time. PMID:23538868
Zheng, Cai-Juan; Shao, Chang-Lun; Wu, Lu-Yong; Chen, Min; Wang, Kai-Ling; Zhao, Dong-Lin; Sun, Xue-Ping; Chen, Guang-Ying; Wang, Chang-Yun
2013-01-01
One new phenylalanine derivative 4?-OMe-asperphenamate (1), along with one known phenylalanine derivative (2) and two new cytochalasins, aspochalasin A1 (3) and cytochalasin Z24 (4), as well as eight known cytochalasin analogues (5–12) were isolated from the fermentation broth of Aspergillus elegans ZJ-2008010, a fungus obtained from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods. The absolute configuration of 1 was determined by chemical synthesis and Marfey’s method. All isolated metabolites (1–12) were evaluated for their antifouling and antibacterial activities. Cytochalasins 5, 6, 8 and 9 showed strong antifouling activity against the larval settlement of the barnacle Balanus amphitrite, with the EC50 values ranging from 6.2 to 37 ?M. This is the first report of antifouling activity for this class of metabolites. Additionally, 8 exhibited a broad spectrum of antibacterial activity, especially against four pathogenic bacteria Staphylococcus albus, S. aureus, Escherichia coli and Bacillus cereus. PMID:23752358
Artemisinin derivatives and malaria: useful, in combination with other antimalarials.
2008-08-01
(1) Plasmodium falciparum malaria can be fatal, especially in young children and non-immune persons. Several drugs are effective but emergence of parasite resistance limits the choice in various parts of the world. Resistance to mefloquine and even to quinine has been reported in Southeast Asia; (2) What is the role of artemisinin derivatives (mainly artesunate and artemether) in the treatment of uncomplicated P. falciparum malaria? To answer this question we conducted a review of the literature, based on Prescrire's standard methodology; (3) Trials of single-agent therapy with artemisinin derivatives showed rapid clinical and parasitological effects, but relapses were frequent during the weeks following treatment. Artemisinin derivatives are therefore used in combination with other antimalarials; (4) In 2006, no parasite resistance to artemisinin derivatives has been detected in Southeast Asia after about 10 years of use; (5) In Southeast Asia, parasitological failure at 28 days was less frequent after treatment with artesunate (for 3 days) plus mefloquine than with mefloquine alone. The artemether + lumefantrine combination has similar efficacy to the artesunate + mefloquine combination. In Africa, several trials have shown that combinations based on artemisinin derivatives are more consistently effective than combinations not including artemisinin derivatives. In regions with high-level resistance to amodiaquine, one trial showed that artemether + lumefantrine was more effective than artesunate + amodiaquine; (6) The main adverse effects of artemisinin derivatives are gastrointestinal and neurological disorders, but less are rarely severe. Combinations based on artemisinin derivatives have different adverse effects, depending on the drugs used; (7) Artesunate is the artemisinin derivative most widely studied in pregnant women: in a series of more than 400 pregnancies, abnormalities were no more frequent than in the general population; (8) In practice, in regions where P. falciparum malaria is endemic, early combination therapy based on artemisinin derivatives is often recommended. For uncomplicated malaria in travellers, combination therapy based on artemisinin derivatives is one option, along with atovaquone + proguanil, quinine (less convenient) and mefloquine (frequent neuropsychological effects). PMID:19492494
17 CFR 39.5 - Information relating to derivatives clearing organization operations.
Code of Federal Regulations, 2010 CFR
2010-04-01
...relating to derivatives clearing organization operations. 39.5 Section...COMMISSION DERIVATIVES CLEARING ORGANIZATIONS § 39.5 Information relating to derivatives clearing organization operations. (a) Upon...
Atomistic simulation of gas transport in polyphosphazenes
NASA Astrophysics Data System (ADS)
Ren, Pengyu
A molecular mechanics study of gas transport in polyphosphazenes is presented in this dissertation. First, a molecular mechanics force field, COMPASS, has been developed for phosphazenes, based on ab initio calculations and molecular dynamics simulations of condensed-phase properties. The force field has been extensively validated by simulation of a number of phosphazenes, in the gas, liquid and crystalline phase. Next, the resulting force field has been successfully applied in the MD simulation of the glass transitions of polyphosphazenes. It is demonstrated that different simulation methods will result in different equilibration states of the amorphous polymers. By building amorphous cells directly at different temperatures using RIS-based approach, better "equilibrated" structures and Tg are obtained. After the force field validation, self-diffusivities and solubilities of a number of gases in two polybutoxyphosphazene isomers---poly[bis( n-butoxy)phosphazene] (PnBuP) and poly[bis(sec-butoxy)phosphazene] (PsBuP) have been calculated from molecular dynamics and Monte Carlo simulations. The diffusion mechanism is studied by gas displacement analysis based on a unique approach that utilizes the digital signal filter to reduce the rattling motions while retaining the characteristic jumps of gas molecules. Finally the structure-property relationships for gas diffusion in rubbery polymers have been investigated by means of accessible free volume distribution and polymer chain dynamics. The polymers selected for this study are three polyphosphazenes isomers---PnBuP, PiBuP (poly[bis(iso-butoxy)phosphazene]), and PsBuP, and two other rubbery polymers---polydimethylsiloxane (PDMS) and polyisobutylene (PIB). Based on the Cohen and Turnbull free volume model for liquids, a statistical model for accessible free volume distribution in rubbery polymers has been derived and validated for above five polymers by simulations using the Transition State approach of Gusev and Suter. It has been shown that gas diffusivity has a linear dependence on the accessible free volume of the polymer. The simulation results indicate that the total free volume is related to the polymer backbone mobility while gas diffusivity is determined not only by the static accessible free volume but also by the dynamics of free volume redistribution that is dominated by the overall mobility of polymer backbone and side chain.
Hesitation Patterns in Third Grade Children's Derived Word Productions
ERIC Educational Resources Information Center
Edrington, Jamie L.; Buder, Eugene H.; Jarmulowicz, Linda
2009-01-01
Hesitations have been considered to serve both cognitive and linguistic functions. This study presents analyses of children's hesitations while producing English derived words with the suffix -"ity". Two questions were considered: Do children's linguistic skills influence their use and frequency of hesitations when producing derived words, and do…
MONOTONICITY, FUZZY EXTREMA, FUZZY CONDITIONAL DERIVATIVES OF REAL
Ferguson, Thomas S.
are obtained as direct corollaries of propositions for fuzzy derivatives, which are proved in this paper. Some derivatives, which are proved in this paper. Such results as the Fuzzy Intermediate Value theorem, Fuzzy logic, fuzzy numbers, fuzzy topologies and so on were introduced and studied. The second direction takes
Robust Replication of Volatility Derivatives and Roger Lee
Lee, Roger
Robust Replication of Volatility Derivatives Peter Carr and Roger Lee This version: May 31, 2009 Abstract In a nonparametric setting, we develop trading strategies to replicate volatility derivatives contracts which pay functions of the realized variance of an underlying asset's returns. The replicating
Effective Ice Particle Densities Derived from Aircraft Data
Andrew J. Heymsfield; Aaron Bansemer; Carl Schmitt; Cynthia Twohy; Michael R. Poellot
2004-01-01
In this study, aircraft data are used to derive effective ice particle densities. This density is defined as the ice particle mass divided by the volume of an equivalent diameter sphere. Measured ice particle size distributions and total ice water contents are used to derive effective ice densities for ice particle populations (rho) as a function of particle size [rhoe(D)].
An alternative derivation of Einstein's Doppler shift and aberration formulae
Jean Reignier
2009-02-06
I propose an alternative, purely kinematical, derivation of Einstein's Doppler formula. It is valid for periodic signals of any shape that propagate with the velocity of light. The formula is asymptotic in a parameter proportional to the relative variation of the distance source-receiver during one period. As a by-product, I also derive an alternative proof of Einstein's aberration formulae.
Hydrodeoxygenation of phenolic components of wood-derived oil
1983-01-01
Hydrotreatment of wood-derived oil to remove phenolic oxygen is a potential upgrading step by which such materials can be rendered compatible with current petroleum refining technology and converted to a diesel equivalent. Accordingly, the hydrodeoxygenation of model phenols and wood derived oil was studied in a batch reactor. Using phenol, a number of commercial catalysts were evaluated for performance and
Advertising in Google Search Deriving a bidding strategy
Boucherie, Richard J.
Advertising in Google Search Deriving a bidding strategy in the biggest auction on earth. Anne This research aims to derive an optimal bidding strategy for keyword auctions in Google Search from;1 Preface We have conducted this research on Google auctions for our bachelor thesis of Applied Mathematics
Novel protein kinase C inhibitors: alpha-terthiophene derivatives.
Kim, D S; Ashendel, C L; Zhou, Q; Chang, C T; Lee, E S; Chang, C J
1998-10-01
A series of alpha-terthiophene derivatives were prepared and their protein kinase C inhibitory activity were evaluated. The aldehyde derivatives were most potent inhibitors (IC50 < 1 microM). alpha-Terthiophene monoaldehyde was inactive in the inhibitions of protein kinase A, mitogen activated protein kinase and protein tyrosine kinase. PMID:9873605
Silole derivatives: relationships between molecular arrangement and OLED efficiency
Paris-Sud XI, UniversitÃ© de
Silole derivatives: relationships between molecular arrangement and OLED efficiency Philippe films and the OLED efficiency. For this purpose, we have synthesized three new silole derivatives to possess both electron- and hole-transporting properties in order to be used in single-layer OLEDs
Asymmetric Hydrogenation of Itaconic Acid and Enol Acetate Derivatives with
Zhang, Xumu
Asymmetric Hydrogenation of Itaconic Acid and Enol Acetate Derivatives with the Rh-TangPhos catalyst has been used for asymmetric hydrogenation of itaconic acid and enol acetate derivatives)- acrylates.3b Herein we report the applications of TangPhos in asymmetric hydrogenation of itaconic acid
Stem CellDerived Cardiomyocytes Demonstrate Arrhythmic Potential
Stem CellDerived Cardiomyocytes Demonstrate Arrhythmic Potential Ying Ming Zhang, MD, PhD; Criss Hartzell, PhD; Michael Narlow, BSc; Samuel C. Dudley, Jr, MD, PhD Background--Cardiomyocytes (CMs) derived, differentiate into cardiomyocytes (CMs), form intercalated disks, and improve cardiac function.2
21 CFR 189.120 - Cobaltous salts and its derivatives.
Code of Federal Regulations, 2013 CFR
2013-04-01
...2013-04-01 2013-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...
21 CFR 189.120 - Cobaltous salts and its derivatives.
Code of Federal Regulations, 2011 CFR
2011-04-01
...2011-04-01 2011-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...
21 CFR 189.120 - Cobaltous salts and its derivatives.
Code of Federal Regulations, 2014 CFR
2014-04-01
...2014-04-01 2014-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...
21 CFR 189.120 - Cobaltous salts and its derivatives.
Code of Federal Regulations, 2012 CFR
2012-04-01
...2012-04-01 2012-04-01 false Cobaltous salts and its derivatives. 189.120 Section...Use as Human Food § 189.120 Cobaltous salts and its derivatives. (a) Cobaltous salts are the chemicals, CoC4 H6 O4 ,...
ORNL/TM-2008/107 The Enterprise Derivative Application
Pennycook, Steve
i ORNL/TM-2008/107 The Enterprise Derivative Application: Flexible Software for Optimizing/107 The Enterprise Derivative Application: Flexible Software for Optimizing Manufacturing Processes Glenn O. Allgood of Energy Efficiency and Renewable Energy, Office of Industrial Technologies, Value Chain Analysis Program
GENERALIZED NEWTON'S METHOD BASED ON GRAPHICAL DERIVATIVES1
Kanzow, Christian
GENERALIZED NEWTON'S METHOD BASED ON GRAPHICAL DERIVATIVES1 Tim Hoheisel1, Christian Kanzow1, Boris of the Newton type to solve systems of nonlinear equations described by nonsmooth continuous functions. We propose and justify a new generalized Newton algorithm based on graphical derivatives, which have never
Lunar surface roughness derived from LRO Diviner Radiometer observations
Bandfield, Joshua L.
Lunar surface roughness derived from LRO Diviner Radiometer observations Joshua L. Bandfield1 wavelength. Thermal infrared measurements from the Lunar Reconnaissance Orbiter Diviner Radiometer were used to derive lunar surface roughness via two observation types: 1) Nadir multispectral observations with full
Justifying Differential Derivations when Setting Up Definite Integrals
ERIC Educational Resources Information Center
Tarvainen, K.
2008-01-01
This paper addresses the forming of integral expressions such as [integral][superscript b][subscript a]f(x)dx by differential or infinitesimal derivations. A rigorous justification of these handy informal derivations is a major pedagogical problem in calculus. In this paper, checks are presented by which one can usually verify--with clear…
Derivative of Area Equals Perimeter--Coincidence or Rule?
ERIC Educational Resources Information Center
Zazkis, Rina; Sinitsky, Ilya; Leikin, Roza
2013-01-01
Why is the derivative of the area of a circle equal to its circumference? Why is the derivative of the volume of a sphere equal to its surface area? And why does a similar relationship not hold for a square or a cube? Or does it? In their work in teacher education, these authors have heard at times undesirable responses to these questions:…
A Methodology to Derive SPDY's Initial Dictionary for Zlib Compression
Delaware, University of
A Methodology to Derive SPDY's Initial Dictionary for Zlib Compression Fan Yang1 , Paul Amer1 a methodology to derive an appropriate initial dictionary for SPDY to compress HTTP headers using the dictionary dictionary, an additional 8% compression of the first HTTP request header and an additional 15% compression
Dairy-Manure Derived Biochar Effectively Sorbs Lead and Atrazine
Ma, Lena
Dairy-Manure Derived Biochar Effectively Sorbs Lead and Atrazine X I N D E C A O , * , , L E N November 13, 2008. Revised manuscript received January 30, 2009. Accepted March 3, 2009. Biochar (BC evaluated the ability of dairy-manure derived biochar to sorb heavy metal Pb and organic contaminant
Dynamics with Infinitely Many Time Derivatives and Rolling Tachyons
Nicolas Moeller; Barton Zwiebach
2002-01-01
Both in string field theory and in p-adic string theory the equations of motion involve infinite number of time derivatives. We argue that the initial value problem is qualitatively different from that obtained in the limit of many time derivatives in that the space of initial conditions becomes strongly constrained. We calculate the energy-momentum tensor and study in detail time
Vitamin B12 Derivatives as Activators of Soluble Guanylyl Cyclase
Proinsias, Keith ó; Gryko, Daniel T.; Hisaeda, Yoshio; Martin, Emil; Sessler, Jonathan L.; Gryko, Dorota
2013-01-01
Various newly prepared and previously known vitamin B12 derivatives have been studied as potential soluble guanylyl cyclase (sGC) activators. All compounds tested were found to activate the sGC enzyme, although to differing extents. The best results were obtained with the derivatives synthesized from c-lactone and possessing aliphatic amides in the c- and d-positions. PMID:22991977
Synthesis and structure characterization of novel luteolin derivatives
Jing Fen Li; Li Sheng Wang; Hai Qiang Bai; Bin Yang; Zhi Gang Chen
2010-01-01
A series of novel luteolin derivatives was synthesized employing the Vilsmeier-Haak-Arnold reaction from the intermediate\\u000a compound 3?,4?,7-trichloro-5-hydroxyflavone, which was obtained from luteolin. These derivatives may be used to improve the\\u000a pharmacological activities of luteolin.
Structural Laws of the Mammalian Kidney, with a Theoretical Derivation
Edward J. Conway
1937-01-01
THE structural laws to be described, though independent of theory, may be derived from certain general principles arising out of a `diffusion-pressure' theory of the kidney. This theory has already been developed to some extent1. The principles of derivation are as follows : (a) The renal secretory cells are equivalent in action throughout the Mammalia, and their function is to
Synthesis and antimicrobial activity of novel quinazolone derivatives.
Habib, N S; Khalil, M A
1984-07-01
Three novel series of 4-oxoquinazoline derivatives were prepared and evaluated as potential antimicrobial agents. Evaluation of the antimicrobial activity of a variety of 4-substituted-1-thiosemicarbazides, 3,4-disubstituted thiazolines, and 3-substituted-5-thiazolidones reveals that the majority possess significant in vitro activity against Gram-positive organisms. Some derivatives also exhibited antifungal activity. PMID:6381690
Concatenable Graph Processes: Relating Processes and Derivation Traces
Baldan, Paolo
Concatenable Graph Processes: Relating Processes and Derivation Traces Paolo Baldan, Andrea proposed for graph rewriting, a powerful formalism for the specification of concurrent and distributed for the algebraic double- pushout approach to graph rewriting, namely the derivation trace and the graph process
Convertible bonds: nancial derivatives of game type Jan Kallsen y
Kallsen, Jan
the holder to convert it immediately. Therefore, the pricing problem has also a game-theoretic aspect. When a mathematically rigorous concept of no-arbitrage price processes for this kind of derivatives, which explicitly this dynamic conception to price derivatives with the static one by Karatzas and Kou [18]. Keywords
Degradation of benzoic acid and its derivatives in subcritical water
Edward Lindquist; Yu Yang
2011-01-01
In this research, the stability of benzoic acid and three of its derivatives (anthranilic acid, salicylic acid, and syringic acid) under subcritical water conditions was investigated. The stability studies were carried out at temperatures ranging from 50 to 350°C with heating times of 10–630min. The degradation of the benzoic acid derivatives increased with rising temperature and the acids became less
Instantaneous phase and frequency derived without user-defined parameters
NASA Astrophysics Data System (ADS)
Poggiagliolmi, E.; Vesnaver, A.
2014-12-01
We define an algorithm in the time domain for computing the unwrapped instantaneous phase and its derivative, the instantaneous frequency, using only derivatives and integrals. It does not require user-defined parameters, like most algorithms proposed so far. We validate and compare its performance with respect to open-source and commercial software by synthetic and real data examples.
Andrographolide: A New Plant-Derived Antineoplastic Entity on Horizon
Astha Varma; Harish Padh; Neeta Shrivastava
2009-01-01
Plant-derived natural products occupy an important position in the area of cancer chemo- therapy. Molecules such as vincristine, vinblastine, paclitaxel, camptothecin derivatives, epipo- dophyllotoxin, etc. are invaluable contributions of nature to modern medicine. However, the quest to find out novel therapeutic compounds for cancer treatment and management is a never-ending venture; and diverse plant species are persistently being studied for
Homotopy bases and finite derivation type for subgroups of monoids
Robert Gray; António Malheiro
2009-01-01
Given a monoid defined by a presentation, and a homotopy base for the derivation graph associated to the presentation, and given an arbitrary subgroup of the monoid, we give a homotopy base (and presentation) for the subgroup. If the monoid has finite derivation type (FDT), and if under the action of the monoid on its subsets by right multiplication the
Pricing temperature-based weather derivatives in China
Ahmet Göncü
2012-01-01
Purpose – The purpose of this paper is to propose a feasible model for the daily average temperatures of Beijing, Shanghai and Shenzhen, in order to price temperature-based weather derivatives; also to derive analytical approximation formulas for the sensitivities of these contracts. Design\\/methodology\\/approach – This study proposes a seasonal volatility model that estimates daily average temperatures of Beijing, Shanghai and
Calculation of Sensitivity Derivatives in an MDAO Framework
NASA Technical Reports Server (NTRS)
Moore, Kenneth T.
2012-01-01
During gradient-based optimization of a system, it is necessary to generate the derivatives of each objective and constraint with respect to each design parameter. If the system is multidisciplinary, it may consist of a set of smaller "components" with some arbitrary data interconnection and process work ow. Analytical derivatives in these components can be used to improve the speed and accuracy of the derivative calculation over a purely numerical calculation; however, a multidisciplinary system may include both components for which derivatives are available and components for which they are not. Three methods to calculate the sensitivity of a mixed multidisciplinary system are presented: the finite difference method, where the derivatives are calculated numerically; the chain rule method, where the derivatives are successively cascaded along the system's network graph; and the analytic method, where the derivatives come from the solution of a linear system of equations. Some improvements to these methods, to accommodate mixed multidisciplinary systems, are also presented; in particular, a new method is introduced to allow existing derivatives to be used inside of finite difference. All three methods are implemented and demonstrated in the open-source MDAO framework OpenMDAO. It was found that there are advantages to each of them depending on the system being solved.
Deriving a Bilingual Lexicon for Cross Language Information Retrieval
Hiemstra, Djoerd
Deriving a Bilingual Lexicon for Cross Language Information Retrieval D. Hiemstra Department@cs.utwente.nl Abstract In this paper we describe a systematic approach to derive a bilingual lexicon automatically from, a bilingual retrieval environment was build. Recall and precision of monolingual (Dutch) retrieval
Risk-neutral hedging of interest rate derivatives
Privault, Nicolas
-neutral measure, and we compute self-financing hedging strategies for various derivatives using the Clark technique, the computation of hedging strategies for such derivatives presents several difficulties] in the jump case. In [6], self-financing hedging strategies have been computed for swap- tions in a geometric
New bactericide derived from Isatin for treating oilfield reinjection water
2012-01-01
Isatin, an extract from Strobilanthes cusia (Nees) Kuntze, was the base for synthesizing derivatives that were screened for antibacterial activity against oilfield water-borne bacteria. The bacterial groups are sulfate reducing, iron and total. The derivatives were characterized by spectrums and they showed good to moderate activity against sulfate reducing bacteria. PMID:22929650
Electrophilic amination of fluoroalkyl groups on azodicarboxylate derivatives.
Mamone, Marius; Morvan, Estelle; Milcent, Thierry; Ongeri, Sandrine; Crousse, Benoit
2015-02-01
The formation of an NCF3 bond or an NCF2R bond still remains scarce. An efficient direct electrophilic amination of fluoroalkyl groups was developed. Difluoroenoxysilanes reacted easily on azodicarboxylate derivatives. These results led to a novel family of NCF3 and NCF2 hydrazine derivatives. PMID:25565083
A Highlevel Derivation of Global Search Algorithms (with Constraint Propagation)
Smith, Douglas R.
propagation and was originally derived using Kids (Kestrel Interactive Development System). The emphasis of global search and constraint propagation and has been derived using KIDS (Kestrel Interactive Development version of several schedulers developed by Kestrel for various organizations (e.g. [3]). KIDS has been
Polyurethane Dispersions Derived from Polycarbonatediols and a Carboxylic Polycaprolactonediol
2005-01-01
Aqueous polyurethane dispersions derived from various polycarbonatediols, a carboxylic polycaprolactonediol, PLACCEL205BA, and isophorone diisocyanate (IPDI) were prepared. The effect of dispersing procedure on the molecular weight was investigated. It was found that a modified dispersing procedure gave polyurethane dispersions with higher molecular weight and better tensile strength. Comparing with polyurethane dispersions derived from dimethylolpropionic acid (DMPA), PLACCEL205BA gave polyurethane dispersions
Induction is not derivable in second order dependent type theory
Geuvers, Herman
Induction is not derivable in second order dependent type theory Herman Geuvers ? Department-derivability of induction in second order dependent type theory (#21;P 2). This is done by providing a model construction extensional combinatory algebra. We give counter-models in which the induction principle over natural num
Induction on Failing Derivations Technical Report PL-Sep13
Ligatti, Jay
Induction on Failing Derivations Technical Report PL-Sep13 Jay Ligatti Department of Computer called induction on failing derivations. We wish to prove properties of judgments in deductive systems for proving such properties on invalid (under- ivable) judgments. The Technique Standard induction
An unusual sesquiterpene derivative from the Caribbean gorgonian Pseudopterogorgia rigida.
D'Armas, H T; Mootoo, B S; Reynolds, W F
2000-11-01
A new sesquiterpene derivative named mochiquinone (1) was isolated from the Caribbean gorgonian coral Pseudopterogorgia rigida collected off northeastern Venezuela, along with the known compounds, alpha-curcumene, (-)-curcuphenol, (-)-curcuquinone, and (-)-curcuhydroquinone. The structure of the new compound was determined by spectroscopic analysis of its acetylated derivative and comparison with known compounds. PMID:11087620
Daytime ionospheric D region sharpness derived from VLF radio atmospherics
Cummer, Steven A.
mode interference pattern in the spectra of radio atmospherics (or sferics for short), which in time domain, researchers derived the D region reflection height of radio waves from the arrival timeDaytime ionospheric D region sharpness derived from VLF radio atmospherics Feng Han,1 Steven A