These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Phosphazenes (2010)  

SciTech Connect

A review of the literature published in 2009 shows an increase in the number of publications addressing phosphazene chemistry over 2008, which suggests a continued strong interest in these intriguing materials. Prominently is the emphasis in the bioactive and biocompatible nature of these materials; although many other applications also exist. Phosphazenes are formed from a phosphorus and nitrogen backbone with pendant group attachments at phosphorus. Typically, they are drawn with alternating single and double bonds between the alternating phosphorus and nitrogen atoms. However, unlike the familiar poly(acetylenes) or poly(thiophenes), the phosphazene backbone is not electrically conductive as there are orbital nodes at phosphorus. Thus, electron delocalization occurs between phosphorus atoms, but not through them. The result of this bonding is a highly flexible backbone that can be controlled through adoit pendant group attachment revealing numerous materials and structures. In this review, novel aspects of the chemistry, structure, and applications of phosphazenes will be discussed.

Frederick F. Stewart

2010-12-01

2

Phosphazene additives  

DOEpatents

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.

Harrup, Mason K; Rollins, Harry W

2013-11-26

3

Phosphazene diamines  

NASA Technical Reports Server (NTRS)

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.

Paciorek, K. L.; Harris, D. H.; Ito, T. I.; Kratzer, R. H.

1980-01-01

4

Phosphorus-nitrogen compounds: New spiro-cyclic phosphazene derivatives. Structure of 4',4',6',6'-tetrachloro-3,4-dihydro-3-(3-methylpyridin-2-yl)spiro-[1,3,2-benzoxazaphosphinine-2,2'-(2lambda5,4lambda5,6lambda5-cyclotriphosphazene)]. Part XII  

Microsoft Academic Search

The condensation reactions of {N-[(2-hydroxyphenylmethyl)amino]-methylpyridines (5 8) with trimer, N3P3Cl6, have been afforded partially substituted novel spiro-cyclic phosphazene derivatives (9 12) (). 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 P21\\/n space group with a=10.7906(10)

Dal Hakan; Safran Serap; Süzen Yasemin; Hökelek Tuncer; Zeynel Kiliç

2005-01-01

5

Novel fire-resistant polyphosphazenes and phosphazene-containing polymers  

NASA Astrophysics Data System (ADS)

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.

Taylor, Jonathan Paul

6

Phosphorus-nitrogen compounds: New spiro-cyclic phosphazene derivatives. Structure of 4?,4?,6?,6?-tetrachloro-3,4-dihydro-3-(3-methylpyridin-2-yl) spiro-[1,3,2-benzoxazaphosphinine-2,2?-(2? 5,4? 5,6? 5-cyclotriphosphazene)]. Part XII  

Microsoft Academic Search

The condensation reactions of {N-[(2-hydroxyphenylmethyl)amino]-methylpyridines (5–8) with trimer, N3P3Cl6, 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 P21\\/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)Å3,

Dal Hakan; Safran Serap; Süzen Yasemin; Hökelek Tuncer; Zeynel K?l?ç

2005-01-01

7

Phosphazene polymer containing composites and method for making phosphazene polymer containing composites  

DOEpatents

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.

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

8

Carboranylmethylene-substituted phosphazenes and polymers thereof  

NASA Technical Reports Server (NTRS)

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.

Allcock, H. R.; Scopelianos, A. G. (inventors)

1984-01-01

9

Hybrid phosphazene anodes for energy storage applications  

SciTech Connect

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.

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

10

Auger parameter measurements of phosphorus compounds for characterization of phosphazenes  

SciTech Connect

This paper presents x-ray generated photoelectron and Auger transition data for several phosphorus reference compounds, including PCl/sub 3/, P/sub 3/N/sub 5/, P/sub 2/O/sub 5/, (C/sub 6/H/sub 5/)/sub 3/P(C/sub 5/H/sub 4/), (C/sub 6/H/sub 5/)/sub 4/PBr, KH/sub 2/PO/sub 4/ (KDP), NH/sub 4/H/sub 2/PO/sub 4/ (ADP), and NH/sub 4/PF/sub 6/. This data has been used to determine the relative ionicity and polarizability of phosphorus in the chlorophosphazene trimer ((NPCl/sub 2/)/sub 3/) and polymer ((NPCl/sub 2/)/sub n/). The results support recent molecular orbital calculations that predict a highly polarized backbone bond in the phosphazenes. Furthermore, the chlorophosphazene polymer was observed to have a greater value for the Auger parameter than the chlorotrimer, indicating that the media surrounding the polymer is more polarizable than that surrounding the trimer. 15 refs., 2 figs., 2 tabs.

Dake, L.S.; Baer, D.R.; Friedrich, D.M.

1988-10-01

11

Auger parameter measurements of phosphorus compounds for characterization of phosphazenes  

SciTech Connect

X-ray generated photoelectron and Auger transition data for several phosphorus reference compounds, including PCl/sub 3/, P/sub 3/ N/sub 5/, P/sub 2/ O/sub 5/, (C/sub 6/ H/sub 5/ )/sub 3/ P(C/sub 5/ H/sub 4/ ), (C/sub 6/ H/sub 5/ )/sub 4/ PBr, KH/sub 2/ PO/sub 4/ , NH/sub 4/H/sub 2/PO/sub 4/, and NH/sub 4/ PF/sub 6/ are presented. These data have been used to determine the relative ionicity and polarizability of phosphorus in the chlorophosphazene trimer ((NPCl/sub 2/ )/sub 3/ ) and polymer ((NPCl/sub 2/ )/sub n/ ). The results support recent molecular-orbital calculations that predict a highly polarized backbone bond in the phosphazenes. Furthermore, the chlorophosphazene polymer was observed to have a greater value for the Auger parameter than the chlorotrimer, indicating that the bonding environment surrounding the polymer is more polarizable than that surrounding the trimer.

Dake, L.S.; Baer, D.R.; Friedrich, D.M.

1989-05-01

12

Automated solid-phase radiofluorination using polymer-supported phosphazenes.  

PubMed

The polymer supported phosphazene bases PS-P?(tBu) and the novel PS-P?(PEG) allowed for efficient extraction of [¹?F]F? from proton irradiated [¹?O]H?O and subsequent radiofluorination of a broad range of substrates directly on the resin. The highest radiochemical yields were obtained with aliphatic sulfonates (69%) and bromides (42%); the total radiosynthesis time was 35-45 min. The multivariate analysis showed that the radiochemical yields and purities were controlled by the resin load, reaction temperature, and column packing effects. The resins could be reused several times with the same or different substrates. The fully automated on-column radiofluorination methodology was applied to the radiosynthesis of the important PET radiotracers [¹?F]FLT and [¹?F]FDG. The latter was produced with 40% yield on a 120 GBq scale and passed GMP-regulated quality control required for commercial production of [1¹?F]FDG. The combination of compact form factor, simplicity of [¹?F]F? recovery and processing, and column reusability can make solid phase radiofluorination an attractive radiochemistry platform for the emerging dose-on-demand instruments for bedside production of PET radiotracers. PMID:23999726

Mathiessen, Bente; Zhuravlev, Fedor

2013-01-01

13

Unsaturated Phosphazenes as Co-Solvents for Lithium-Ion Battery Electrolytes  

SciTech Connect

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.

Mason K Harrup; Harry W. Rollins; David K. Jamison; Eric J Dufek; Kevin L Gering; Thomas A Luther

2014-07-01

14

Organocatalytic Stereoselective Ring-Opening Polymerization of Lactide with Dimeric Phosphazene Bases  

SciTech Connect

Highly isotactic polylactide with a high melting temperature was synthesized from rac-lactide through an organocatalytic route using dimeric phosphazene base 1-tert-butyl-2,2,4,4,4-pentakis(dimethylamino)-2 5,4 5-catenadi(phosphazene) (P2-t-Bu) catalyst at low temperature. Microstructural analysis of the prepared polymer using homodecoupled 1H NMR spectroscopy revealed the formation of a stereoblock architecture containing long isotactic sequence of R- and S- blocks in the main chain. A proposed mechanism involving chain-end control and stereoerror explains the stereoselective polymerization.

Zhang, Lei [Almaden Research Center; Nederberg, Fredrik [Almaden Research Center; Messman, Jamie M [ORNL; Pratt, Russel C [Almaden Research Center; Hedrick, James [Almaden Research Center; Wade, Charles G [Almaden Research Center

2007-01-01

15

A Study of Novel Hexavalent Phosphazene Salts as Draw Solutes in Forward Osmosis  

SciTech Connect

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).

Mark L. Stone; Aaron D. Wilson; Mason K. Harrup; Frederick F. Stewart

2013-03-01

16

Antibacterial activity and mutagenicity studies of water-soluble phosphazene high polymers.  

PubMed

Eight water-soluble phosphazene high polymers, [NPR2]n (R, organic, water-solubilizing side-group; n, approx: 15,000) and the small-molecule counterparts of the polymers were examined for antibacterial activity against six different strains of bacteria (Escherichia coli, Salmonella typhimurium (TA 100), Salmonella pullorum, Streptococcus faecalis, Bacillus subtilis and Pseudomonas aeruginosa). Antibacterial testing was carried out by measuring zones of inhibition and changes in solution turbidity over time. In addition, the antibacterial activity of the surfaces of cross-linked poly[di(methoxyethoxyethoxy)phosphazene] (MEEP) hydrogels were investigated. A number of the high polymers, as well as the MEEP hydrogels, impeded bacterial growth. Only E. coli was unaffected by the phosphazenes. A possible explanation for the antibacterial character of the polymers is presented. The same compounds were monitored for potential mutagenic activity using the Salmonella typhimurium tester strains TA 100 and TA 98. None of the high polymers or their small-molecule analogues showed mutagenic activity in either strain of Salmonella at the concentrations tested. The use of these materials as coatings for artificial implants is discussed. PMID:1457679

Allcock, H R; Pucher, S R; Fitzpatrick, R J; Rashid, K

1992-01-01

17

Phosphazene Based Additives for Improvement of Safety and Battery Lifetimes in Lithium-Ion Batteries  

SciTech Connect

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.

Mason K Harrup; Kevin L Gering; Harry W Rollins; Sergiy V Sazhin; Michael T Benson; David K Jamison; Christopher J Michelbacher

2011-10-01

18

Separations of hazardous organics from gas and liquid feedstreams using phosphazene polymer membranes  

SciTech Connect

The liquid-liquid and gas separation properties for the separation of hazardous organic feed streams using pervaporation and gas separation methods with poly[bis(phenoxy)phosphazene] based membranes are reported. Liquid transport behavior was determined using pervaporation techniques. The preliminary gas separations were studied using a mixed gas separation method which the authors have described previously. Using the membrane pervaporation technique, separation factors of 10,000 have been routinely achieved for the separation of methylene chloride from water. Other tests have shown similar results for the removal of hydrocarbon vapors from air. Membranes were prepared using solution casting techniques. Solvent evaporation rates during the casting and subsequent curing processes were controlled to provide a consistent membrane microstructure. These results suggest that polyphosphazene membrane technology could effectively be used in cleaning up air and ground water that has been contaminated with chlorinated hydrocarbons.

Peterson, E.S.; Stone, M.L.; Cummings, D.G.; McCaffrey, R.R. [Idaho National Engineering Lab., Idaho Falls (United States)

1993-01-01

19

Fluorinated Phosphazene Co-solvents for Improved Thermal and Safety Performance in Lithium-Ion Battery Electrolytes  

SciTech Connect

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.

Harry W. Rollins; Mason K. Harrup; Eric J. Dufek; David K. Jamison; Sergiy V. Sazhin; Kevin L. Gering; Dayna L. Daubaras

2014-10-01

20

Ligand and structure effects on the N-P bonds of phosphazenes  

SciTech Connect

The influence of different ligands on the electronic structure of the N-P backbone bond in phosphazene trimers and polymers has been studied using x-ray photoelectron spectroscopy, XPS. This paper extends previously reported work, which showed the highly polarized nature of the N-P bond in the chlorophosphazene polymer and trimer, to include the following ligands: chloride, fluoride, methoxy, trifluoroethoxy and phenoxy. Wagner chemical-state plots constructed for nitrogen and phosphorus demonstrate the ligand effects, and highlight the differences between the polymers and the corresponding cyclic trimers. Phosphorus photoline and x-ray excited Auger line energies were found to shift in a manner consistent with the electronegativity and polarizability of the side groups for both the polymers and trimers. In general, the nitrogen data followed the same trends as the phosphorus, with some exceptions. The value of the phosphorus Auger parameter was consistently higher for the polymers than for the corresponding trimers, suggesting a structural effect on the polarizability of the backbone bond. These experimental results are interpreted using the results of ab initio molecular orbital calculations performed for phosphonitrilic trimers, tetramers and small linear fragments. 15 refs., 5 figs., 5 tabs.

Dake, L.S.; Baer, D.R.; Ferris, K.F.; Friedrich, D.M.

1989-07-01

21

Poly[di(carboxylatophenoxy)phosphazene] is a potent adjuvant for intradermal immunization  

PubMed Central

Intradermal immunization using microfabricated needles represents a potentially powerful technology, which can enhance immune responses and provide antigen sparing. Solid vaccine formulations, which can be coated onto microneedle patches suitable for simple administration, can also potentially offer improved shelf-life. However the approach is not fully compatible with many vaccine adjuvants including alum, the most common adjuvant used in the vaccine market globally. Here, we introduce a polyphosphazene immuno adjuvant as a biologically potent and synergistic constituent of microneedle-based intradermal immunization technology. Poly[di(carboxylatophenoxy)phosphazene], PCPP, functions both as a vaccine adjuvant and as a key microfabrication material. When used as part of an intradermal delivery system for hepatitis B surface antigen, PCPP demonstrates superior activity in pigs compared to intramascular administration and significant antigen sparing potential. It also accelerates the microneedle fabrication process and reduces its dependence on the use of surfactants. In this way, PCPP-coated microneedles may enable effective intradermal vaccination from an adjuvanted patch delivery system. PMID:19864632

Andrianov, Alexander K.; DeCollibus, Daniel P.; Gillis, Helice A.; Kha, Henry H.; Marin, Alexander; Prausnitz, Mark R.; Babiuk, Lorne A.; Townsend, Hugh; Mutwiri, George

2009-01-01

22

Preparation of Coaxial-Electrospun Poly[bis(p-methylphenoxy)]phosphazene Nanofiber Membrane for Enzyme Immobilization  

PubMed Central

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

Wang, Shu-Gen; Jiang, Xin; Chen, Peng-Cheng; Yu, An-Guo; Huang, Xiao-Jun

2012-01-01

23

Synthesis of biodegradable poly(methylparaben\\/glycine ethyl ester) phosphazene and further research of its degradation in vitro  

Microsoft Academic Search

Polydichlorophosphazene (PDCP) was synthesized from PCl5 and NH4Cl via a one-pot approach, and then further reacted with glycine ethyl ester and methylparaben via a two-step nucleophilic\\u000a substitution approach to give poly(methylparaben\\/glycine ethyl ester)phosphazene (PMGP), which was a kind of mix-substituted\\u000a biodegradable polymer. NMR and FT-IR were used to characterize its structure. A series of experiments were conducted to study\\u000a the

XiaoBin Huang; KuiYong Chen; Jing Li; YuanLi Zheng; JinGui Jiang; XiaoZhen Tang

2011-01-01

24

Activity of urea amidohydrolase immobilized within poly[di(methoxyethoxyethoxy)phosphazene] hydrogels.  

PubMed

Urea amidohydrolase (urease) was immobilized within poly[di(methoxyethoxyethoxy)phosphazene] (MEEP) hydrogels. This was accomplished by mixing an aqueous solution (pH 7) of the soluble polymer with the enzyme. Films of the conjugate were cast and the solvent removed to yield an MEEP/enzyme composite. The conjugate films were dried in a vacuum and were then cross-linked by exposure to 0.2 or 0.5 Mrad of 60Co gamma-radiation to give an MEEP network with the enzyme entrapped within its matrix. The cross-linked films were sectioned into strips and were washed with pH 7 buffer to remove enzyme adhering to the surface. The films were then allowed to swell to form a hydrogel in pH 7 buffer to which was added a 1.0 M aqueous urea solution. The increase in pH from the conversion of urea to ammonia was monitored over a 24 h period. The immobilized enzyme could be recycled at least five times without significant loss of activity. Several control experiments were also performed by monitoring the pH of buffer solutions that contained hydrogels devoid of entrapped urease, and by monitoring the pH of solutions of the free, non-irradiated and free, irradiated urease after the addition of the urea solution. The polymer-free, irradiated urease lost little to no activity compared with its non-irradiated counterpart. The MEEP gel-immobilized enzyme retained approximately 80% of the activity of the non-irradiated, polymer-free urease. PMID:7918902

Allcock, H R; Pucher, S R; Visscher, K B

1994-06-01

25

Plasma surface functionalization of poly[bis(2,2,2-trifluoroethoxy)phosphazene] films and nanofibers.  

PubMed

Polyphosphazenes are a class of hybrid organic-inorganic macromolecules with high thermo-oxidative stability and good solubility in many solvents. Fluoroalkoxy phosphazene polymers also have high surface hydrophobicity. A method is described to tune this surface property while maintaining the advantageous bulk materials characteristics. The polyphosphazene single-substituent polymer, poly[bis(2,2,2-trifluoroethoxy)phosphazene], with flat film, fiber mat, or bead mat morphology was surface functionalized using an atmospheric plasma treatment with oxygen, nitrogen, methane, or tetrafluoromethane/hydrogen gases. Surface chemistry changes were detected by static water contact angle (WCA) measurements as well as X-ray photon spectroscopy (XPS). It was found that changes in the WCA of as much as 150 degrees occurred, accompanied by shifts in the ratio of elements on the polymer surface as detected by XPS. Overall this plasma technique provides a convenient method for the generation of specific surface characteristics while maintaining the hydrophobicity of the bulk material. PMID:17590030

Allcock, Harry R; Steely, Lee B; Kim, Seong H; Kim, Jeong H; Kang, Bang-Kwon

2007-07-17

26

Characterization of 2-(2-Methoxyethoxy)ethanol Substituted Phosphazene Polymers Using Pervaporation, Solubility Parameters and Sorption Studies  

SciTech Connect

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.

Orme, Christopher Joseph; Klaehn, John Ray; Harrup, Mason Kurt; Lash, Robert Paul; Stewart, Frederick Forrest

2005-05-01

27

Oxygen gas permeability in water and mechanical properties of poly(n-butylamino)-(di-allylamino)phosphazene membranes cured with irradiation  

SciTech Connect

Poly(n-butylamino)(di-allylamino)phosphazenes were prepared by the reaction of (NPCL{sub 2}){sub n} with n-butylamine and di-allylamine. After the membranes were prepared by casting method, they were irradiated by UV, EB and {sup 60}Co {gamma}-ray. It was found from FTIR data that the CH {double_bond} CH{sub 2}/N-H ratios of the irradiated membranes were decreased with increasing doses. Also, the membrane did not dissolve in THF or other organic solvents. This supported that the CH {double_bond} CH{sub 2} bond was cleaved by the irradiation and the cross-linking occurred between the intermolecular. Oxygen gas permeability values (D{sub k}) of the irradiated membrane were determined with oxygen permeater and mechanical properties were determined with Tensilon. D{sub k} values were decreased with increasing Young`s modulus in the case of low concentration of di-allylamine.

Kajiwara, M.; Kimura, T. [Nagoya Univ. (Japan)

1995-10-01

28

Derivatives  

NSDL National Science Digital Library

Murray Bourne developed the Interactive Mathematics site while working as a mathematics lecturer at Ngee Ann Polytechnic in Singapore. The site contains numerous mathematics tutorials and resources for students and teachers alike. This specific page is focused on differentiation, or finding derivatives. Bourne walks users through an introduction to differentiation and limits, and then moves on to more specific applications like rate of change, derivatives of polynomials, and differentiating powers of a function. Each topic includes graphs and interactive materials designed to aid users in understanding the presented concepts. The information here is presented in a clear, straightforward manner that is appropriate for introductory and advanced calculus students alike.

Bourne, Murray

2008-04-22

29

Derivate  

NSDL National Science Digital Library

In this activity, students input functions in order to calculate the derivative and tangent line of that function. This activity allows students to explore tangent lines of various functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

30

Section IV.D.3 for DOE 2013 Annual Report: Novel Phosphazene-based Compounds to Enhance Safety and Stability of Cell Chemistries for High Voltage Applications (INL)  

SciTech Connect

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.

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

31

A semiempirical scaled force field for simple short-chain phosphazenes Cl 3P?N?(PCl 2?N) n?1 ?P(O)Cl 2 ( n = 1 and 2)  

Microsoft Academic Search

The present paper reports a set of force constants calculated with a MNDO hamiltonian and scaled using a non-linear optimization procedure to reproduce the observed vibrational frequencies of simple short-chain phosphazenes. The results support the presence of a lower energy conformer of O?P(Cl)2?N?P(Cl)3. Normal coordinate analysis of O?P(Cl)2?N?P(Cl)2?N?P(Cl)3 was also carried out. Conformations, bonding and flexibility are discussed in terms

A. Elass; P. Dhamelincourt; R. Becquet; G. Vergoten

1996-01-01

32

Phosphorus nitrogen compounds: Novel fully substituted spiro-cyclophosphazenic lariat (PNP-pivot) ether derivatives. Structures of 4,4,6,6-tetrapyrrolidino-2,2-[3-oxa-1,5-pentane dioxy bis(2-phenylamino)]cyclo-2lambda5,4lambda5,6lambda5-triphosphazene and 4,4,6,6-tetrapyrrolidino-2,2-[1,2-xylylene dioxy bis(2-phenylamino)]cyclo-2lambda5,4lambda5,6lambda5-triphosphazene. Part XI  

Microsoft Academic Search

The condensation reaction of partly substituted spiro-cyclophosphazenic lariat (PNP-pivot) ethers, N3P3[(o-NHPhO)2R]Cl4 (5 8), where R= CH2CH2 , CH2CH2CH2 , CH2CH2OCH2CH2 , and CH2PhCH2 , with pyrrolidine have been afforded fully substituted pyrrolidino phosphazene derivatives (9 12) (Scheme). There are the first examples of the spiro-cyclophosphazenic lariat (PNP-pivot) ether ligands with N2Ox-(x=2, 3) donor type containing 11 14 membered macrocycles. The

Selen Bilge; Bilgehan Özgüç; Serap Safran; Semsay Demiriz; Hikmet Isler; Mustafa Hayvali; Zeynel Kiliç; Tuncer Hökelek

2005-01-01

33

Derivatives Page  

NSDL National Science Digital Library

Derivatives are financial securities whose value is derived from another "underlying" financial security. Options, futures, swaps, swaptions, and structured notes are all examples of derivative securities. Derivatives can be used in hedging, protecting against financial risk, or can be used to speculate on the movement of commodity or security prices, interest rates, or the levels of financial indices. The valuation of derivatives makes use of the statistical mathematics of uncertainty. With links to related articles. See also Derivatives Concepts A-Z, glossary of derivatives-related terminology designed to make the other articles in the Financial Pipeline's Derivatives section easier to understand.

34

Constrained-geometry bisphosphazides derived from 1,8-diazidonaphthalene: synthesis, spectroscopic characteristics, structural features, and theoretical investigations.  

PubMed

Investigations on the Staudinger reaction between 1,8-diazidonaphthalene and phosphorous(III) building blocks, a key step in the synthesis of superbasic bisphosphazene proton sponges, yielded a set of bisphosphazides with a constrained geometry 1,8-disubstituted naphthalene backbone. This compound class has attracted our interest not only due to their surprisingly high stability, but in particular because of their theoretically predicted basicity in the range of their bisphosphazene analogues that can be referred to the constrained geometry interaction of two highly basic nitrogen atoms. Eleven new bisphosphazides bearing simple P-amino groups as well as P-guanidino substituents, azaphosphatrane moieties, P2 building blocks, or chiral P-amino substituents derived from L-proline are presented. They were studied concerning their spectroscopic properties and partly also their chromophoric and structural features. In the case of the pyrrolidino-substituted TPPN(2N2) (TPPN = 1,8-bis(trispyrrolidinophosphazenyl)naphthalene), the stepwise nitrogen elimination is investigated theoretically and experimentally, which led to the isolation and structural characterization of TPPN(1N2) bearing a phosphazide and a phosphazene functionality in one molecule. Attempts to protonate the obtained bisphosphazides and to prove the computationally predicted pKBH(+) values through NMR titration reactions resulted in their decay, which again was rationalized by theoretical calculations. Altogether we present the so far most extensive spectroscopic, structural and theoretical investigation of constrained geometry bisphosphazides and their Brønsted and Lewis basic properties. PMID:24687589

Kögel, Julius F; Abac?lar, Nuri C; Weber, Felicia; Oelkers, Benjamin; Harms, Klaus; Kova?evi?, Borislav; Sundermeyer, Jörg

2014-05-12

35

Complex derivatives  

NASA Astrophysics Data System (ADS)

The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

2013-03-01

36

Glycal Derivatives  

NASA Astrophysics Data System (ADS)

Glycals are unsaturated sugar derivatives in which the double bond engages the anomeric carbon atom. Such cyclic vinyl ethers are characterized by high reactivity, allowing for regio- and stereoselective transformations, directly or indirectly related to glycosylation, as well as to formation of carbon-carbon and carbon-heteroatom bonds at the anomeric center. This review provides a systematic survey of chemical synthetic methods, by which the carbon-carbon double bond is introduced next to the ring oxygen, in an endo- or exocyclic position. Some mechanistic aspects are discussed in relation to traditional methods of glycal preparation, which rely on elimination reactions. Glycal-to-glycal rearrangement and applications of organometallic chemistry and heteroatom-induced transformations for syntheses and activation of glycals are also highlighted.

Priebe, Waldemar; Fokt, Izabela; Grynkiewicz, Grzegorz

37

Auger parameter measurements of phosphorus compounds for characterization of phosphazenes  

Microsoft Academic Search

X-ray generated photoelectron and Auger transition data for several phosphorus reference compounds, including PClâ, Pâ Nâ, Pâ Oâ, (Câ Hâ )â P(Câ Hâ ), (Câ Hâ )â PBr, KHâ POâ , NHâHâPOâ, and NHâ PFâ are presented. These data have been used to determine the relative ionicity and polarizability of phosphorus in the chlorophosphazene trimer ((NPClâ )â ) and polymer

L. S. Dake; D. R. Baer; D. M. Friedrich

1989-01-01

38

Auger parameter measurements of phosphorus compounds for characterization of phosphazenes  

Microsoft Academic Search

This paper presents x-ray generated photoelectron and Auger transition data for several phosphorus reference compounds, including PClâ, PâNâ, PâOâ, (CâHâ)âP(CâHâ), (CâHâ)âPBr, KHâPOâ (KDP), NHâHâPOâ (ADP), and NHâPFâ. This data has been used to determine the relative ionicity and polarizability of phosphorus in the chlorophosphazene trimer ((NPClâ)â) and polymer ((NPClâ)\\/sub n\\/). The results support recent molecular orbital calculations that predict a

L. S. Dake; D. R. Baer; D. M. Friedrich

1988-01-01

39

Thermal degradation chemistry of poly[bis(phenoxy)phosphazene  

E-print Network

the model compound studies and from the degradation of PBPP suggests that phenyl migration occurs at some stage during degradation. Some of these findings are in disagreement with previously reported studies. P solution-state and solid-state NMR... CONCLUSIONS REFERENCES Y ITA Dynamic degradation of PBPP samples ~othermal degradation of model compound samples. P Solution-State NMR characterization of PBPP samples. Isothermal degradation of PBPP samples Solution-State hydrolysis of PBPP samples...

Maynard, Shawn Joseph

1989-01-01

40

Higher order fractional derivatives  

E-print Network

Based on the Liouville-Weyl definition of the fractional derivative, a new direct fractional generalization of higher order derivatives is presented. It is shown, that the Riesz and Feller derivatives are special cases of this approach.

Richard Herrmann

2009-06-12

41

Absolute Time Derivatives  

E-print Network

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.

T. Matolcsi; P. Van

2006-08-31

42

Partial Derivatives: Geometric Visualization  

NSDL National Science Digital Library

This write-pair-share activity presents Calculus III students with a worksheet containing several exercises that require them to find partial derivatives of functions of two variables. Afterwards, a series of Web-based animations are used to illustrate the surface of each function, the path of the indicated partial derivative for a specified value of the variable and the value of the derivative at each point along the path.

Rutledge, James

43

The Dangers of Derivatives.  

ERIC Educational Resources Information Center

Heavy investment in derivatives, whose value derives from the price movement of some underlying security, has meant heavy losses for some colleges and universities despite the fact that institutional investors are required to assure that they understand the risks of such investment. (MSE)

Blumenstyk, Goldie

1994-01-01

44

Partial Derivative Visualization Gallery  

NSDL National Science Digital Library

This resource is a small gallery of demos for illustrating partial derivatives geometrically. These animations can be used by instructors in a classroom setting or by students to aid in acquiring a visualization background for partial derivatives. Two file formats, gif and QuickTime files are used for the animations which can be downloaded.

Roberts, Lila F.

2004-11-11

45

The Partial Derivative Machine  

NSDL National Science Digital Library

Research has shown that students struggle to understand the use of partial derivatives in thermodynamics. We have designed an apparatus, which we have called a Partial Derivative Machine, that serves as a mechanical analogue of a thermodynamic system. Using this device, students have a tangible way to wrestle with issues related to partial derivatives and thermodynamics, such as which variables are held fixed, how many variables are independent, and how energy can be added to a system. In this paper, we present a description of the apparatus, an introduction to the associated activities, and an overview of how this apparatus can be connected to thermodynamic systems.

Sherer, Grant; Kustusch, Mary B.; Manogue, Corinne A.; Roundy, David J.

2014-01-31

46

Derivative Matching Game  

NSDL National Science Digital Library

Once again, the Mathematical Association of America has struck instructional gold with this latest gem from their online collection of resources for mathematics educators. Created by Barbara Margolius, this derivative matching game presents users with a game board showing graphs of functions on cards. Essentially, the goal of the game is to match the functions with their derivatives. Visitors can begin by reading an overview of the game, along with some brief instructions, and then they should dive right in. The game can also be customized to match functions with just first derivatives or both first and second derivatives. Mathematics educators will have a lot of fun with this one, and even the mathematically uncertain can be drawn into the fold with this easy to use resource.

2009-05-29

47

Derivative Matching Game  

NSDL National Science Digital Library

Once again, the Mathematical Association of America has struck instructional gold with this latest gem from their online collection of resources for mathematics educators. Created by Barbara Margolius, this derivative matching game presents users with a game board showing graphs of functions on cards. Essentially, the goal of the game is to match the functions with their derivatives. Visitors can begin by reading an overview of the game, along with some brief instructions, and then they should dive right in. The game can also be customized to match functions with just first derivatives or both first and second derivatives. Mathematics educators will have a lot of fun with this one, and even the mathematically uncertain can be drawn into the fold with this easy to use resource.

48

Credit derivatives in Brazil  

E-print Network

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 ...

Rüther, Henrique

2007-01-01

49

Teaching Cournot without Derivatives.  

ERIC Educational Resources Information Center

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)

Dufwenberg, Martin

2001-01-01

50

Cyclodextrin derivative of hyaluronan  

Microsoft Academic Search

Conversion of hyaluronan (HA) to its ?-cyclodextrin derivative (HA-?-CD) was accomplished by direct coupling of ?-cyclodextrin (?-CD) molecules with carboxylic acid groups of the HA macromolecule. The intermolecular dehydration, yielding the HA-?-CD derivative, was performed by the action of diethyl azodicarboxylate and triphenylphosphine under mild, neutral conditions. The physico-chemical characteristics of the novel (bio)material, determined both in solution and solid

L. Šoltés; R. Mendichi; E. Machovà; B. Steiner; J. Alföldi; V. Sasinkovà; S. Bystrický; K. Balog

1999-01-01

51

Myeloid derived suppressor cells  

PubMed Central

The goal of achieving measurable response with cancer immunotherapy requires counteracting the immunosuppressive characteristics of tumors. One of the mechanisms that tumors utilize to escape immunosurveillance is the activation of myeloid derived suppressor cells (MDSCs). Upon activation by tumor-derived signals, MDSCs inhibit the ability of the host to mount an anti-tumor immune response via their capacity to suppress both the innate and adaptive immune systems. Despite their relatively recent discovery and characterization, anti-MDSC agents have been identified, which may improve immunotherapy efficacy. PMID:23734336

Waldron, Todd J.; Quatromoni, Jon G.; Karakasheva, Tatiana A.; Singhal, Sunil; Rustgi, Anil K.

2013-01-01

52

Derivatives of tetrodecamycin.  

PubMed

The derivatives of tetrodecamycin (1), being introduced acyl, carbamoyl and alkyl groups at 14-hydroxyl group and modified at exo-methylene group, were synthesized and evaluated on their antibacterial activities. Although 14-O-substituted tetrodecamycins (3 approximately 19) showed weak activity against Pasteurella piscicida, they were more active against Gram-positive bacteria than 1. Among them, 15 showed approximately 10-fold higher activity than 1. The derivatives (20 approximately 23) modified at 4 or 5 positions had moderate antibacterial activity. The absolute structure of 4(R),5-dibromotetrodecamycin (23) was determined by X-ray crystallographic analysis. PMID:8557576

Tsuchida, T; Iinuma, H; Nakamura, K T; Nakamura, H; Sawa, T; Hamada, M; Takeuchi, T

1995-11-01

53

Telomeric 30 Overhangs Derive  

E-print Network

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

de Lange, Titia

54

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...

55

Fractional Derivative Cosmology  

E-print Network

The degree by which a function can be differentiated need not be restricted to integer values. Usually most of the field equations of physics are taken to be second order, curiosity asks what happens if this is only approximately the case and the field equations are nearly second order. For Robertson-Walker cosmology there is a simple fractional modification of the Friedman and conservation equations. In general fractional gravitational equations similar to Einstein's are hard to define as this requires fractional derivative geometry. What fractional derivative geometry might entail is briefly looked at and it turns out that even asking very simple questions in two dimensions leads to ambiguous or intractable results. A two dimensional line element which depends on the Gamma-function is looked at.

Mark D. Roberts

2009-09-07

56

Insulin-derived amyloidosis  

PubMed Central

Amyloidosis is the term for diseases caused by the extracellular deposition of insoluble polymeric protein fibrils in tissues and organs. Insulin-derived amyloidosis is a rare, yet significant complication of insulin therapy. Insulin-derived amyloidosis at injection site can cause poor glycemic control and increased insulin dose requirements because of the impairment in insulin absorption, which reverse on change of injection site and/or excision of the mass. This entity should be considered and assessed by histopathology and immunohistochemistry, in patients with firm/hard local site reactions, which do not regress after cessation of insulin injection at the affected site. Search strategy: PubMed was searched with terms “insulin amyloidosis”. Full text of articles available in English was reviewed. Relevant cross references were also reviewed. Last search was made on October 15, 2014.

Gupta, Yashdeep; Singla, Gaurav; Singla, Rajiv

2015-01-01

57

[Synthesis of porphyrin derivatives].  

PubMed

This paper presents the preparation of eleven 2, 4 or 6, 7-substituted porphyrine derivatives II-XII from I or diethyl ether of IV. The effects of these compounds, with irradiation, on DNA synthesis in L1210 cells were studied. The results showed that (1) all of these compounds were effective while (2) Va or Vb, VI and VII were more effective. PMID:1839589

Lu, Y H; Liu, F C

1991-01-01

58

Computation of Mie derivatives.  

PubMed

Analytical expressions are obtained for the derivatives of Mie scattering coefficients with respect to the electrical radius of the spherical scattering particle, and to the relative permittivity and permeability of both the particle and the surrounding medium. Their corresponding approximate expressions are developed to avoid numerical overflow based on the logarithmic derivative of Riccati-Bessel functions. The analytical expressions have been verified by comparing their results with those calculated by analytical expressions developed by Mathematica. Compared with the numerical derivative, the analytical expressions and approximate expressions show a higher accuracy and are 2.0 and 2.8 times, respectively, faster in the case of a single magnetodielectric sphere. Generally, for spheres with an electrical radius in a large range, the approximate expressions can yield acceptable accuracy and computation time up to a high order. This work can be used in the design of nonmetallic metamaterials, and in the retrieval of aerosol properties from remote sensing data. An example calculation is given for the design of an optical, all-dielectric, mu-negative metamaterial consisting of a simple cubic array of tellurium nanoparticles. PMID:23852216

Li, Yang; Bowler, Nicola

2013-07-10

59

Synthesis of tetrahydrobenzimidazole derivatives  

Microsoft Academic Search

O! l| 3,5,5-Trimethyl- 7-ketotetrahydro benzimidazole (III) was similarly obtained from 5,5-dimethylcycl ohexane-l,2,3-tri one monophenylhydraz one. Treatment of the sodium derivative of III with bromoacetophenone and then with ammonium acetate in acetic acid gave the previously unknown 2,8,8-trimethyl- 5-phenyl7,8-dihydro-9H-p yrazino [3,2,1-h,i]benzimidazole (IV), which was isolated as the picrate. H3C\\\\ ~.~ tlaC CH 3

V. I. Shvedov; L. B. Altukhova; A. N. Grinev

1972-01-01

60

Acquiring Knowledge of Derived Nominals and Derived Adjectives in Context  

ERIC Educational Resources Information Center

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…

Marinellie, Sally A.; Kneile, Lynn A.

2012-01-01

61

Radioactively labelled porphyrin derivatives  

NASA Astrophysics Data System (ADS)

Radioactive labelling of guanidine-bearing tetraphenylporphyrin and Dy—texaphyrin with selected radionuclides (166Ho and 90Y) is described. A basic characterisation of studied porphyrin and texaphyrin, including their behaviour in a wide range of pH values and data on holmium and yttrium complexation with these compounds was probed using UV-VIS absorption spectrometry. The labelling yield of these macrocyclic molecules depends on the pH of the reaction mixture, metal: ligand ratio and time of incubation. Optimal reaction conditions for formation of porphyrin and texaphyrin radioactive complexes were determined by thin layer chromatography with the detection of ?- activity. The ability of porphyrin derivatives to bind anions was examined as well. Our experiments were focused on perrhenate ion (ReO4 -) because radiopharmaceuticals labelled with isotopes 186Re and 188Re play an important role in therapy of numerous tumour diseases. The possibility of applying ReO4 - anion directly for labelling purposes, without the necessity of its reduction to lower oxidation state, was not proved.

Koní?ová, R.; Ernestová, M.; Jedináková-K?ížová, V.; Král, V.

2003-01-01

62

Vaccine-derived polioviruses.  

PubMed

The attenuated oral poliovirus vaccine (OPV) has many properties favoring its use in polio eradication: ease of administration, efficient induction of intestinal immunity, induction of durable humoral immunity, and low cost. Despite these advantages, OPV has the disadvantage of genetic instability, resulting in rare and sporadic cases of vaccine-associated paralytic poliomyelitis (VAPP) and the emergence of genetically divergent vaccine-derived polioviruses (VDPVs). Whereas VAPP is an adverse event following exposure to OPV, VDPVs are polioviruses whose genetic properties indicate prolonged replication or transmission. Three categories of VDPVs are recognized: (1) circulating VDPVs (cVDPVs) from outbreaks in settings of low OPV coverage, (2) immunodeficiency-associated VDPVs (iVDPVs) from individuals with primary immunodeficiencies, and (3) ambiguous VDPVs (aVDPVs), which cannot be definitively assigned to either of the first 2 categories. Because most VDPVs are type 2, the World Health Organization's plans call for coordinated worldwide replacement of trivalent OPV with bivalent OPV containing poliovirus types 1 and 3. PMID:25316847

Burns, Cara C; Diop, Ousmane M; Sutter, Roland W; Kew, Olen M

2014-11-01

63

Phosphorus-nitrogen compounds: part 30. Syntheses and structural investigations, antimicrobial and cytotoxic activities and DNA interactions of vanillinato-substituted NN or NO spirocyclic monoferrocenyl cyclotriphosphazenes.  

PubMed

The gradual Cl replacement reactions of NN (1-3) or NO spirocyclic monoferrocenyl cyclotriphosphazenes (4 and 5) with the potassium salt of 4-hydroxy-3-methoxybenzaldehyde (potassium vanillinate) resulted in the mono (1a-5a), geminal (gem-1b-5b), non-geminal (cis-5b and trans -1b-4b), tri (1c, 3c-5c) and tetra-vanillinato-substituted phosphazenes (1d-5d). All the phosphazene derivatives have stereogenic P-center(s), except tetra-substituted ones. The vanillinatophosphazenes have reversible voltammograms with one-electron anodic and cathodic peaks which are attributed to ferrocenyl redox probe. The structures of the new phosphazene compounds were determined by FTIR, MS, (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectral data. The solid-state structure of cis -5b was examined by single-crystal X-ray diffraction techniques. In addition, the compounds were tested in HeLa cancer cell lines using MTT assay. The 12 phosphazene derivatives were screened for antimicrobial activity, and 3c was very effective against S. aureus even at 4.88 µM concentration, taking into account the MIC values. Besides, interactions between the phosphazenes and pBR322 plasmid DNA were also investigated. PMID:25491284

Tümer, Yasemin; Koç, L Yasemin; Asmafiliz, Nuran; K?l?ç, Zeynel; Hökelek, Tuncer; Soltanzade, Hossien; Aç?k, Leyla; Yola, Mehmet Lütfi; Solak, Ali Osman

2015-01-01

64

Deriving bedform phase diagrams  

NSDL National Science Digital Library

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.

Tom Hickson

65

CHITOSAN DERIVATIVES FOR TISSUE ENGINEERING.  

E-print Network

??Chitosan, a naturally occurring polysaccharide, and its derivatives have been widely explored for biomedical applications due to their biocompatibility and biodegradability. In our studies, we… (more)

Qiu, Yongzhi

2008-01-01

66

Limits and Derivatives: The Derivative as a Function  

NSDL National Science Digital Library

Sketch the graph of the derivative of a geometrically represented function;Explain the correspondence between the sign of the derivative on an interval and the monotonicity of the function on that interval. Classify the basic ways in which a function may fail to be differentiable.

Freeze, Michael

2003-01-22

67

Cellulose Derivatives Derived From Pulp and Paper Mill Sludge  

Microsoft Academic Search

Cellulose derivatives were produced from the cellulose fraction of pulp and paper mill sludge. The raw primary sludge was reacted under conventional cellulose derivatization conditions and the modified cellulose was isolated, in most cases, by dissolution in a suitable solvent. The cellulose derivatives produced were cellulose nitrate, cellulose acetate, carboxymethylcellulose, hydroxyethylcellulose, and methylcellulose. These compounds were characterized by Fourier transform

David G. Barkalow; Raymond A. Young

1985-01-01

68

Alternative algebras admitting derivations with invertible values and invertible derivations  

NASA Astrophysics Data System (ADS)

We prove an analogue of the Bergen-Herstein-Lanski theorem for alternative algebras: describe all alternative algebras that admit derivations with invertible values. We also prove an analogue of Moens' theorem for alternative algebras (a finite-dimensional alternative algebra over a field of characteristic zero is nilpotent if and only if it admits an invertible Leibniz derivation).

Kaygorodov, I. B.; Popov, Yu S.

2014-10-01

69

Elementary derivation of Kepler's laws  

Microsoft Academic Search

A simple derivation of all three so-called Kepler laws is presented in which the orbits, bound and unbound, follow directly and immediately from conservation of energy and angular momentum. The intent is to make this crowning achievement of Newtonian mechanics easily accessible to students in introductory physics courses. The method is also extended to simplify the derivation of the Rutherford

Erich Vogt

1996-01-01

70

Inflation Derivatives L. P. Hughston  

E-print Network

Inflation Derivatives L. P. Hughston Department of Mathematics King's College London The Strand (0)207 848 2855 Abstract. A general theory for the pricing and hedging of inflation The purpose of this note is to outline briefly a general model of inflation and inflation-linked derivatives

Macrina, Andrea

71

12 CFR 563.172 - Financial derivatives.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Financial derivatives. 563.172 Section 563.172 Banks...Management Policies § 563.172 Financial derivatives. (a) What is a financial derivative? A financial derivative is a...

2010-01-01

72

Elevation Derivatives for National Applications  

USGS Publications Warehouse

The Elevation Derivatives for National Applications (EDNA) project is a multi-agency effort to develop standard topographically derived layers for use in hydrologic and environmental modeling. The EDNA takes advantage of the seamless and filtered characteristics for the National Elevation Dataset (NED) to create a hydrologically conditioned Digital Elevation Model (DEM) useful for modeling applications. The goals of the project are to create a hydrologically conditioned DEM and systematically extract a set of standard derivatives that can be used to facilitate data integration with other U.S. Geological Survey (USGS) framework data sets such as the National Hydrography Dataset (NHD) and the Watershed Boundaries Dataset (WBD).

U.S. Geological Survey

2005-01-01

73

Quinazoline derivatives: synthesis and bioactivities  

PubMed Central

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

2013-01-01

74

Radioactive stilbene derivatives in radioimmunoassay  

SciTech Connect

Novel radioactive stilbene derivatives marked with iodine 125 or 131 possessing an iodine acceptor group and marked with iodine 125 or 131 and their preparation and antigens obtained therefrom and a process for preparing said antigens.

Jouquey, A.; Touyer, G.

1985-07-16

75

On Derivation of Goldman Bracket  

E-print Network

In this paper, we derive Goldman-type bracket for traces of monodromy matrices of flat connections on a compact Riemann surface for $G_{2}$ gauge group. As a by-product, we give an alternative derivation of known Goldman bracket for classical gauge groups $GL(n,\\mathbb{R})$, $SL(n,\\mathbb{R})$, $U(n)$, $SU(n)$, $Sp(2n,\\mathbb{R})$ and $SO(n)$.

S. Hasibul Hassan Chowdhury

2013-10-16

76

Organic derivatives of zirconium phosphate  

E-print Network

ORGANIC DERIVATIVES OF ZIRCONIUM PHOSPHATE A Thesis by STEVEN BERYL FINE Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1980 Major Subject...: Chemistry ORGANIC DERIVATIVES OF ZIRCONIUM PHOSPHATE A Thesis by STEVEN BERYL FINE Approved as to style and content by: Dr. A raham Clearfield (c irman) Dr. Kurt Irgolic (member) 4~~@4 Dr. Martha Scott (member) Dr. C. S. Giam (department head...

Fine, Steven Beryl

2012-06-07

77

Ionone derivatives from Alternanthera sessilis.  

PubMed

The chloroform extract of the air-dried leaves of Alternanthera sessilis afforded a mixture of diastereomers of a new ionone derivative 1 whose structures were elucidated by extensive 1D and 2D NMR spectroscopy and mass spectrometry. Oxidative cleavage of 1 to aldehyde 3 with manganese dioxide confirmed diastereoisomerism arose from a racemic side chain chiral centre. Antimicrobial tests on the mixture of diastereomers and the derivative indicated that they have low activities against Pseudomonas aeruginosa and Trichophyton mentagrophytes. PMID:12067155

Ragasa, Consolacion Y; Tremor, Noemi; Rideout, John A

2002-06-01

78

Derivative-Free Optimization Proximal Point Methods Derivative-Free Proximal Point Conclusion Derivative-Free Optimization via Proximal  

E-print Network

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

79

Drugs derived from phage display  

PubMed Central

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

Nixon, Andrew E; Sexton, Daniel J; Ladner, Robert C

2014-01-01

80

Pregnane derivatives from Potentilla evestita.  

PubMed

A new pregnane derivative, 2,6beta,7beta-trihydroxy-4-methyl-19-norpregna-1,3,5(10)-trien-17-one, has been isolated from the ethyl acetate soluble fraction of Potentilla evestita along with a pregnane derivative, 11alpha,17alpha,21-trihydroxypregna-4,16(22)-diene-3,20-dione, that is reported for the first time as a natural product. Their structures were elucidated with the aid of 1H and 13C NMR spectra and by COSY, HMQC, HMBC and NOESY experiments. PMID:21922903

Khan, Rehan; Siddiq, Farah; Fatima, Itrat; Yasmeen, Shazia; Karim, Aman; Malik, Abdul; Afza, Nighat; Hameed, Saira

2011-08-01

81

Canonical derivation of effective potentials  

E-print Network

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.

Martin Bojowald; Suddhasattwa Brahma

2014-11-13

82

Canonical derivation of effective potentials  

E-print Network

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.

Bojowald, Martin

2014-01-01

83

Fractional Derivatives in Dengue Epidemics  

NASA Astrophysics Data System (ADS)

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.

Pooseh, Shakoor; Rodrigues, Helena Sofia; Torres, Delfim F. M.

2011-09-01

84

40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721...721.10039 Diethoxybenzenamine derivative, diazotized, coupled with...

2010-07-01

85

On derivations of low dimensional associative dialgebras  

NASA Astrophysics Data System (ADS)

This study introduces a new algorithm for finding derivation of associative dialgebras. The algorithm applied to compute the derivations of low dimensional associative dialgebras. Some simple properties of derivation in terms of left multiplication operators also are provided.

Abubakar, Mohamed; Rakhimov, I. S.; Rikhsiboev, I. M.

2014-06-01

86

28 CFR 17.26 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Derivative classification. 17.26 Section...Classified Information § 17.26 Derivative classification. (a) Persons...classification guides. (b) Persons who apply derivative classification markings shall...

2010-07-01

87

40 CFR 721.1820 - Bisphenol derivative.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Bisphenol derivative. 721.1820 Section 721.1820...Substances § 721.1820 Bisphenol derivative. (a) Chemical substance and significant...substance identified generically as bisphenol derivative (PMN No. P-92-509) is...

2010-07-01

88

40 CFR 721.5913 - Phenothiazine derivative.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Phenothiazine derivative. 721.5913 Section 721.5913...Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant...identified generically as a phenothiazine derivative (PMN P-96-813) is subject...

2010-07-01

89

32 CFR 2001.22 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Derivative classification. 2001.22 Section...Identification and Markings § 2001.22 Derivative classification. (a) General... (b) Identity of persons who apply derivative classification markings....

2010-07-01

90

40 CFR 721.9658 - Thiadiazole derivative.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Thiadiazole derivative. 721.9658 Section 721.9658...Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant...substance identified as a thiadiazole derivative (PMN P-94-1631) is subject...

2010-07-01

91

46 CFR 503.55 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Derivative classification. 503.55 Section...Information Security Program § 503.55 Derivative classification. (a) In...apply to the source information, is derivative classification. (1)...

2010-10-01

92

Quantum White Noise Derivatives and Implementation Problem  

E-print Network

. . Quantum White Noise Derivatives and Implementation Problem On the occasion of thier 60th, 2009 Nobuaki Obata (GSIS, Tohoku University) Quantum White Noise Derivatives and Implementation Problem (GSIS, Tohoku University) Quantum White Noise Derivatives and Implementation Problem Fukuoka, November

Obata, Nobuaki

93

Informational derivation of quantum theory  

SciTech Connect

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.

Chiribella, Giulio; D'Ariano, Giacomo Mauro; Perinotti, Paolo [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Ontario, N2L 2Y5 (Canada); QUIT Group, Dipartimento di Fisica ''A. Volta'' and INFN Sezione di Pavia, via Bassi 6, I-27100 Pavia (Italy)

2011-07-15

94

Deriving Laws from Ordering Relations  

Microsoft Academic Search

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

Kevin H. Knuth; Moffett Field CA

2004-01-01

95

Quaternion Derivatives: The GHR Calculus  

E-print Network

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.

Dongpo Xu; Cyrus Jahanchahi; Clive C. Took; Danilo P. Mandic

2014-09-25

96

On Derivations Of Genetic Algebras  

NASA Astrophysics Data System (ADS)

A genetic algebra is a (possibly non-associative) algebra used to model inheritance in genetics. In application of genetics this algebra often has a basis corresponding to genetically different gametes, and the structure constant of the algebra encode the probabilities of producing offspring of various types. In this paper, we find the connection between the genetic algebras and evolution algebras. Moreover, we prove the existence of nontrivial derivations of genetic algebras in dimension two.

Mukhamedov, Farrukh; Qaralleh, Izzat

2014-11-01

97

Electrofugality index for benzhydryl derivatives  

NASA Astrophysics Data System (ADS)

We propose and test an empirical electrofugality index to rank the leaving group ability of a series of 21 benzhydryl derivatives. The empirical model defines the electrofugality as the negative of the global electrophilicity of the carbocation intermediate in the hydrolysis reaction. The results are in good agreement with the experimental electrofugality scale proposed for the title compounds by Mayr and coworkers [B. Denegri, A. Streiter, S. Júric, A.R. Ofial, O. Kronja, H. Mayr, Chem. Eur. J. 12 (2006) 1648].

Campodónico, Paola R.; Pérez, Claudio; Aliaga, Margarita; Gazitúa, Marcela; Contreras, Renato

2007-10-01

98

Derivation of Hamiltonians for accelerators  

SciTech Connect

In this report various forms of the Hamiltonian for particle motion in an accelerator will be derived. Except where noted, the treatment will apply generally to linear and circular accelerators, storage rings, and beamlines. The generic term accelerator will be used to refer to any of these devices. The author will use the usual accelerator coordinate system, which will be introduced first, along with a list of handy formulas. He then starts from the general Hamiltonian for a particle in an electromagnetic field, using the accelerator coordinate system, with time t as independent variable. He switches to a form more convenient for most purposes using the distance s along the reference orbit as independent variable. In section 2, formulas will be derived for the vector potentials that describe the various lattice components. In sections 3, 4, and 5, special forms of the Hamiltonian will be derived for transverse horizontal and vertical motion, for longitudinal motion, and for synchrobetatron coupling of horizontal and longitudinal motions. Hamiltonians will be expanded to fourth order in the variables.

Symon, K.R.

1997-09-12

99

An assessment of derived flood frequency distributions  

E-print Network

Flood Frequency Curve - Turtle Creek. . . FIG. 9. Statistical Flood Frequency Curve - Halls Bayou . . . . . . 51 . . . 51 FIG. 10. Derived Flood Frequency Curves ? South Rocky Creek. . . . . . 53 FIG. 11. Derived Flood Frequency Curves - Briar Creek... . . FIG. 12, Derived Flood Frequency Curves - Turtle Creek. . . FIG. 13. Derived Flood Frequency Curves - Halls Bayou. . . . . . . . . . . . . . FIG. 14. Simulation Flood Frequency Curve ? South Rocky Creek. . . . . . 54 . . . 56 FIG. 15. Simulation...

Raines, Timothy Howard

1991-01-01

100

Binder enhanced refuse derived fuel  

DOEpatents

A refuse derived fuel (RDF) pellet having about 11% or more particulate calcium hydroxide which is utilized in a combustionable mixture. The pellets are used in a particulate fuel bring a mixture of 10% or more, on a heat equivalent basis, of the RDF pellet which contains calcium hydroxide as a binder, with 50% or more, on a heat equivalent basis, of a sulphur containing coal. Combustion of the mixture is effective to produce an effluent gas from the combustion zone having a reduced SO.sub.2 and polycyclic aromatic hydrocarbon content of effluent gas from similar combustion materials not containing the calcium hydroxide.

Daugherty, Kenneth E. (Lewisville, TX); Venables, Barney J. (Denton, TX); Ohlsson, Oscar O. (Naperville, IL)

1996-01-01

101

Deriving Ontologies from XML Schema  

E-print Network

In this paper, we present a method and a tool for deriving a skeleton of an ontology from XML schema files. We first recall what an is ontology and its relationships with XML schemas. Next, we focus on ontology building methodology and associated tool requirements. Then, we introduce Janus, a tool for building an ontology from various XML schemas in a given domain. We summarize the main features of Janus and illustrate its functionalities through a simple example. Finally, we compare our approach to other existing ontology building tools.

Bedini, Ivan; Nguyen, Benjamin

2010-01-01

102

Generalized derivatives and generalized convexities  

SciTech Connect

We give a survey of the contributions of the speaker and of his co-authors in the use of nonsmooth analysis for the study of generalized convexities such as quasiconvexity, pseudoconvexity, invexity. One line of though corresponds to the use of generalized directional derivatives, as in S. Komlosi. Another track consists in using a subdifferential. This could be done in an axiomatic way, but we use essentially three classical instances; the Clarke subdifferential, the contingent subdifferential and the Frechet subdifferential. For algorithmic purposes, variants of Plastra`s subdifferential can be use.

Penot, J.P.; Quang, P.H.; Sach, P.H.

1994-12-31

103

Diagrammatic Derivation of Lovelock Densities  

E-print Network

We discuss a method of calculating the various scalar densities encountered in Lovelock theory which relies on diagrammatic, instead of algebraic manipulations. Taking advantage of the known symmetric and antisymmetric properties of the Riemann tensor which appears in the Lovelock densities, we map every quadratic or higher contraction into a corresponding permutation diagram. The derivation of the explicit form of each density is then reduced to identifying the distinct diagrams, from which we can also read off the overall combinatoric factors. The method is applied to the first Lovelock densities, of order two (Gauss-Bonnet term) and three.

C. Bogdanos

2009-04-19

104

Diagrammatic derivation of Lovelock densities  

SciTech Connect

We discuss a method of calculating the various scalar densities encountered in Lovelock theory, which relies on diagrammatic, instead of algebraic manipulations. Taking advantage of the known symmetric and antisymmetric properties of the Riemann tensor that appears in the Lovelock densities, we map every quadratic or higher contraction into a corresponding permutation diagram. The derivation of the explicit form of each density is then reduced to identifying the distinct diagrams, from which we can also read off the overall combinatoric factors. The method is applied to the first Lovelock densities, of order two (Gauss-Bonnet term) and three.

Bogdanos, C. [Laboratoire de Physique Theorique, Universite de Paris-Sud 11, Batiment 210, 91405 Orsay CEDEX (France)

2009-05-15

105

Diagrammatic derivation of Lovelock densities  

NASA Astrophysics Data System (ADS)

We discuss a method of calculating the various scalar densities encountered in Lovelock theory, which relies on diagrammatic, instead of algebraic manipulations. Taking advantage of the known symmetric and antisymmetric properties of the Riemann tensor that appears in the Lovelock densities, we map every quadratic or higher contraction into a corresponding permutation diagram. The derivation of the explicit form of each density is then reduced to identifying the distinct diagrams, from which we can also read off the overall combinatoric factors. The method is applied to the first Lovelock densities, of order two (Gauss-Bonnet term) and three.

Bogdanos, C.

2009-05-01

106

Fourth order spatial derivative gravity  

SciTech Connect

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.

Bemfica, F. S.; Gomes, M. [Instituto de Fisica, Universidade de Sao Paulo Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil)

2011-10-15

107

Paleovirology and virally derived immunity.  

PubMed

Paleovirology, the study of viruses on evolutionary timescales, can exploit information from endogenous viral elements (EVEs), which are the result of heritable horizontal gene transfer (HGT) from viruses to hosts. The availability of genomic data has increased opportunities to study EVEs, and bioinformatics techniques have been crucial in cataloguing EVE diversity and taxonomic coverage. Recent advances show that some EVEs have been co-opted as cellular genes, often as inhibitors of viral infection. These genes are an intriguing strategy in virus-host evolutionary battles in that genetic material is transferred from virus to host, and then used by the host against the virus. In this review, we consider the genes and processes involved in EVE-derived immunity (EDI), assess factors leading to its emergence, and outline how future work will benefit from incorporating evolutionary approaches. PMID:22901901

Aswad, Amr; Katzourakis, Aris

2012-11-01

108

Optical nonlinearities of perylene derivatives  

NASA Astrophysics Data System (ADS)

Nonlinear optical properties of perylene derivatives were studied by femtosecond Z-scan technique. 3,4,9,10-Perylenetetracarboxylic dianhydride (PTCDA), 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), and perylene-66 (dibenzthiophenoperylene-N,N'-dicyclohexylimide), were studied. Tetrahydrofuran was used as a solvent for perylene- 66. The solubility of PTCDA and PTCDI is very poor. Their colloidal solution was prepared by the irradiation of the third harmonics of a pulsed YAG laser to opaque suspension of PTCDA and PTCDI. Transparent colloidal solution was obtained within 50 minutes of UV irradiation. Colloidal solution of quinacridone was also studied. Two-photon absorption cross sections of these dyes were measured by open aperture Z-scan method using a femtosecond laser. The dependence of two-photon cross section on laser wavelength was measured in the wavelength range of 780-820 nm.

Sasaki, Yoshihiko; Takamo, Hiroyuki; Kasatani, Kazuo

2008-01-01

109

Deriving Laws from Ordering Relations  

NASA Technical Reports Server (NTRS)

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.

Knuth, Kevin H.

2003-01-01

110

Deriving Ephemeral Authentication Using Channel Axioms  

E-print Network

Deriving Ephemeral Authentication Using Channel Axioms Dusko Pavlovic1 and Catherine Meadows2 1 of Mathematics/ISG. #12;Deriving Ephemeral Authentication Using Channel Axioms 239 of the information sent along

Sheldon, Nathan D.

111

5 CFR 2500.5 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative...PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves...

2010-01-01

112

17 CFR 200.506 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...Exchanges 2 2010-04-01 2010-04-01 false Derivative classification. 200.506 Section 200.506 Commodity...National Security Information and Material § 200.506 Derivative classification. Any document that includes...

2010-04-01

113

12 CFR 563.172 - Financial derivatives.  

Code of Federal Regulations, 2012 CFR

... SAVINGS ASSOCIATIONS-OPERATIONS Financial Management Policies § 563.172 Financial derivatives...responsible for daily oversight and management of financial derivatives activities. Management must implement the policies and...

2012-01-01

114

12 CFR 563.172 - Financial derivatives.  

Code of Federal Regulations, 2011 CFR

... SAVINGS ASSOCIATIONS-OPERATIONS Financial Management Policies § 563.172 Financial derivatives...responsible for daily oversight and management of financial derivatives activities. Management must implement the policies and...

2011-01-01

115

12 CFR 563.172 - Financial derivatives.  

... SAVINGS ASSOCIATIONS-OPERATIONS Financial Management Policies § 563.172 Financial derivatives...responsible for daily oversight and management of financial derivatives activities. Management must implement the policies and...

2014-01-01

116

12 CFR 163.172 - Financial derivatives.  

Code of Federal Regulations, 2013 CFR

... SAVINGS ASSOCIATIONS-OPERATIONS Financial Management Policies § 163.172 Financial derivatives...responsible for daily oversight and management of financial derivatives activities. Management must implement the policies and...

2013-01-01

117

12 CFR 563.172 - Financial derivatives.  

Code of Federal Regulations, 2013 CFR

... SAVINGS ASSOCIATIONS-OPERATIONS Financial Management Policies § 563.172 Financial derivatives...responsible for daily oversight and management of financial derivatives activities. Management must implement the policies and...

2013-01-01

118

12 CFR 163.172 - Financial derivatives.  

... SAVINGS ASSOCIATIONS-OPERATIONS Financial Management Policies § 163.172 Financial derivatives...responsible for daily oversight and management of financial derivatives activities. Management must implement the policies and...

2014-01-01

119

A study on real estate derivatives  

E-print Network

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 ...

Lim, Jong Yoon, S.M. Massachusetts Institute of Technology

2006-01-01

120

40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...  

Code of Federal Regulations, 2011 CFR

...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...

2011-07-01

121

40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...  

...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...

2014-07-01

122

40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

123

Stability derivatives of cones at supersonic speeds  

NASA Technical Reports Server (NTRS)

The aerodynamic stability derivatives due to pitching velocity and vertical acceleration are derived for circular cones traveling at supersonic speeds. Both first-order and a combination of first and second order potential solutions are obtained, and in calculations for the forces, no approximations are made to the tangency condition or the isentropic pressure relation. In addition, expressions for the forces, moments, and stability derivatives of arbitrary bodies of revolution are derived from Newtonian impact theory.

Tobak, Murry; Wehrend, William R

1956-01-01

124

Derived data for decision support systems  

Microsoft Academic Search

In decision-making situations requiring “what-if” analysis, in statistical databases, and in distributed databases, it is desirable to explicitly store derived data without losing consistency with the original data. We introduce independently-updated views (IUVs) for storage and use of derived data for decision-support systems. IUVs support multiple versions, provide derivation transparency, maintain data consistency, and afford control over time of derivation.

Richard G. Ramirez; Uday R. Kulkarni; Kathleen A. Moser

1996-01-01

125

Improved Second Derivative Test for Relative Extrema  

ERIC Educational Resources Information Center

In this note, a modified Second Derivative Test is introduced for the relative extrema of a single variable function. This improved test overcomes the difficulty of the second derivative vanishing at the critical point, while in contrast the traditional test fails for this case. A proof for this improved Second Derivative Test is presented,…

Wu, Yan

2007-01-01

126

Structural design utilizing updated, approximate sensitivity derivatives  

NASA Technical Reports Server (NTRS)

A method to improve the computational efficiency of structural optimization algorithms is investigated. In this method, the calculations of 'exact' sensitivity derivatives of constraint functions are performed only at selected iterations during the optimization process. The sensitivity derivatives utilized within other iterations are approximate derivatives which are calculated using an inexpensive derivative update formula. Optimization results are presented for an analytic optimization problem (i.e., one having simple polynomial expressions for the objective and constraint functions) and for two structural optimization problems. The structural optimization results indicate that up to a factor of three improvement in computation time is possible when using the updated sensitivity derivatives.

Scotti, Stephen J.

1993-01-01

127

Unconventional fuel: Tire derived fuel  

SciTech Connect

Material recovery of scrap tires for their fuel value has moved from a pioneering concept in the early 1980`s to a proven and continuous use in the United States` pulp and paper, utility, industrial, and cement industry. Pulp and paper`s use of tire derived fuel (TDF) is currently consuming tires at the rate of 35 million passenger tire equivalents (PTEs) per year. Twenty mills are known to be burning TDF on a continuous basis. The utility industry is currently consuming tires at the rate of 48 million PTEs per year. Thirteen utilities are known to be burning TDF on a continuous basis. The cement industry is currently consuming tires at the rate of 28 million PTEs per year. Twenty two cement plants are known to be burning TDF on a continuous basis. Other industrial boilers are currently consuming tires at the rate of 6.5 million PTEs per year. Four industrial boilers are known to be burning TDF on a continuous basis. In total, 59 facilities are currently burning over 117 million PTEs per year. Although 93% of these facilities were not engineered to burn TDF, it has become clear that TDF has found acceptance as a supplemental fuel when blending with conventional fuels in existing combustion devices designed for normal operating conditions. The issues of TDF as a supplemental fuel and its proper specifications are critical to the successful development of this fuel alternative. This paper will focus primarily on TDF`s use in a boiler type unit.

Hope, M.W. [Waste Recovery, Inc., Portland, OR (United States)

1995-09-01

128

Clinical status of benzoporphyrin derivative  

NASA Astrophysics Data System (ADS)

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.

Levy, Julia G.; Chan, Agnes H.; Strong, H. Andrew

1996-01-01

129

Chromatography of urinary indole derivatives.  

PubMed

Latest strategies are discussed for the routine chromatographic analysis of clinically important indole derivatives in urine. Analysis of 5-hydroxyindoleacetic acid and, perhaps more importantly, serotonin and 5-hydroxytryptophan remains attractive in the screening for carcinoid tumours and their differentiation. Analyses of two precursors of the skin pigment eumelanin seem to be promising in the monitoring of treatment of malignant melanoma and screening for pigmentation disorders and gallstone formation. Studies on the clinical relevance of the determination of tetrahydro-beta-carbolines and melatonin-related indoles await routine application of chromatographic methods designed to take into consideration the relative instability of these compounds. Application of GC-MS, although confined to larger and/or governmental laboratories remains attractive as a way of improving the specificity of analyses and in establishing reference methods. As for HPLC, the recent development of chromatographic and detection methods for the concurrent determination of different clinically important and metabolically related compounds from the same sample, preferably by direct injection techniques, seems to be fruitful and should be continued. PMID:3062030

van Haard, P M

1988-07-29

130

Representations of partial derivatives in thermodynamics  

NSDL National Science Digital Library

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).

Thompson, John R.; Manogue, Corinne A.; Roundy, David J.; Mountcastle, Donald B.

2012-05-15

131

Satellite-Derived Management Zones  

NASA Technical Reports Server (NTRS)

The term "satellite-derived management zones" (SAMZ) denotes agricultural management zones that are subdivisions of large fields and that are derived from images of the fields acquired by instruments aboard Earth-orbiting satellites during approximately the past 15 years. "SAMZ" also denotes the methodology and the software that implements the methodology for creating such zones. The SAMZ approach is one of several products of continuing efforts to realize a concept of precision agriculture, which involves optimal variations in seeding, in application of chemicals, and in irrigation, plus decisions to farm or not to farm certain portions of fields, all in an effort to maximize profitability in view of spatial and temporal variations in the growth and health of crops, and in the chemical and physical conditions of soils. As used here, "management zone" signifies, more precisely, a subdivision of a field within which the crop-production behavior is regarded as homogeneous. From the perspective of precision agriculture, management zones are the smallest subdivisions between which the seeding, application of chemicals, and other management parameters are to be varied. In the SAMZ approach, the main sources of data are the archives of satellite imagery that have been collected over the years for diverse purposes. One of the main advantages afforded by the SAMZ approach is that the data in these archives can be reused for purposes of precision agriculture at low cost. De facto, these archives contain information on all sources of variability within a field, including weather, crop types, crop management, soil types, and water drainage patterns. The SAMZ methodology involves the establishment of a Web-based interface based on an algorithm that generates management zones automatically and quickly from archival satellite image data in response to requests from farmers. A farmer can make a request by either uploading data describing a field boundary to the Web site or else drawing the boundary on a reference image. Hence, a farmer can start to engage in precision farming shortly after gaining access to the Web site, without the need for incurring the high costs of conventional precision-agriculture data-collection practices that include collecting soil samples, mapping electrical conductivity of soil, and compiling multiyear crop-yield data. Given the boundary of a field, a SAMZ server computes the zones within the field in a three-stage process. In the first stage, a vector-valued image of the field is constructed by assembling, from the archives, the equivalent of a stack of the available images of the field (see figure). In the second stage, the vector-valued image is analyzed by use of a wavelet transform that detects spatial variations considered significant for precision farming while suppressing small-scale heterogeneities that are regarded as insignificant. In the third stage, a segmentation algorithm assembles the zones from smaller regions that have been identified in the wavelet analysis.

Lepoutre, Damien; Layrol, Laurent

2005-01-01

132

Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives  

PubMed Central

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

Moribe, Kunikazu; Limwikrant, Waree; Higashi, Kenjirou; Yamamoto, Keiji

2011-01-01

133

Mantle derived economic sulfide mineralization?  

NASA Astrophysics Data System (ADS)

Sulfide ores of the unique Pt-Cu-Ni Noril'sk deposits are characterized by heavy sulfur isotopic composition (d34S = 6-18 ‰ ; Grinenko, 1985). These data are traditionally explained by the crustal contamination of the mantle melts by Devonian sedimentary rocks with anhydrites at certain depths or in a chamber of crystallization (Naldrett, 1992; Li et al., 2009). However, data on the distribution of major and trace elements and isotopic composition (their eNd, 87Sr/86Sr, d34S) in the contact zones of the intrusions with the host rocks are at variance with any significant in-situ contamination. Moreover , the mechanism of the "digestion" of this high-temperature material (Tm = 1430ºC) by the lower temperature magma (1250ºC) has never been analyzed and questioned. Our pioneering data on the sulfur radiogenic isotopes in the anhydrite are in conflict with the hypothesis that this mineral could serve as a sulfur source for the Noril'sk ores. The fact that the average composition of the intrusions is independent on the stratigraphic setting of these intrusions, which can be hosted by limestone, sandstone, and/or basalt, provides further support for the idea that no assimilation took place at the depths of the chambers in which the melts crystallized.The reason for the heavy sulfur isotopic composition of ores in the Noril'sk district is still uncertain. Last data obtained on the sulfur isotopic composition of basalts and ores from some intrusions in the Taimyr Peninsula likely provide a clue to this problem. The highest d34S values in rocks of all of the trap formations were detected in the Gudchikhinsky picrites (d34S = +8,7; Ripley et al., 2003) formed from a primitive mantle magma. They are geochemically similar to the rocks from the Dyumtaleysky Massif (d34S = 12.2; Krivolutskaya and Gongalsky, 2013) which crystallized from a primitive mantle-derived magma (with no Ta-Nb and Pb anomalies and high Gd/Yb ratio) too. This intrusion comprises economic important sulfide ores with geochemical and mineralogical characteristics similar to unique Noril'sk deposits - Talnakh, Okty'abr sky and Norilsk 1. The features of the Dyumtaleysky massif can be explained by its origin from an unusual sulfide-bearing mantle source that had sulfides through earlier crustal-mantle interaction. These data support that the mantle source of magmas in the Noril'sk district was enriched in the heavy sulfur isotope. It is the age difference that could be responsible for the unusual composition of the Noril'sk ores, because the mantle source in the Early Mesozoic was remarkably different from that in the Proterozoic one, when practically all Cu-Ni deposits worldwide were produced.

Krivolutskaya, Nadezda; Gongalskiy, Bronislav; Svirskaya, Natalia

2014-05-01

134

75 FR 63113 - Financial Resources Requirements for Derivatives Clearing Organizations  

Federal Register 2010, 2011, 2012, 2013

...Financial Resources Requirements for Derivatives Clearing Organizations AGENCY: Commodity...financial resources requirements for derivatives clearing organizations (DCOs) for...execution requirements on standardized derivative products; (3) creating...

2010-10-14

135

Design and synthesis of new vancomycin derivatives.  

PubMed

A set of vancomycin derivatives with lipid chain attached via a glyceric acid linker was designed and synthesized. A concise synthesis towards these derivatives was developed and the IC50s of these new lipoglycopeptides were tested. Some of them showed very potent activity against both vancomycin sensitive and resistant strains. PMID:24751442

Gu, Wen; Chen, Bei; Ge, Min

2014-05-15

136

Auto-oxidative coupling of glycine derivatives.  

PubMed

The unprecedented title reaction between glycine derivatives and indoles, as well as the auto-oxidative Povarov/aromatization tandem reaction of glycine derivatives with olefins are described. The reactions were performed in the absence of redox-active catalysts and chemical oxidants under mild reaction conditions. Only simple organic solvents and air (or O2 ) were required. PMID:25288283

Huo, Congde; Yuan, Yong; Wu, Mingxia; Jia, Xiaodong; Wang, Xicun; Chen, Fengjuan; Tang, Jing

2014-12-01

137

Tilt/Integral/Derivative Compensators For Controllers  

NASA Technical Reports Server (NTRS)

Tilt/integral/derivative (TID) compensators for tunable feedback control systems offer advantages over proportional/integral/derivative compensators. Designed and adjusted more easily, and made to reject disturbances more strongly and less sensitive to variations in parameters of controlled system.

Lurie, Boris J.

1995-01-01

138

Few Fractional Order Derivatives and Their Computations  

ERIC Educational Resources Information Center

This work presents an introductory development of fractional order derivatives and their computations. Historical development of fractional calculus is discussed. This paper presents how to obtain computational results of fractional order derivatives for some elementary functions. Computational results are illustrated in tabular and graphical…

Bhatta, D. D.

2007-01-01

139

Understanding the Derivative through the Calculus Triangle  

ERIC Educational Resources Information Center

Typical treatments of the derivative do not clearly convey the idea that the derivative function represents the original function's rate of change. Revealing the relationship between a function and its rate-of-change function for static values of "x" does not facilitate productive ways of thinking about generating the rate-of-change function or…

Weber, Eric; Tallman, Michael; Byerley, Cameron; Thompson, Patrick W.

2012-01-01

140

Genetic Optimization Using Derivatives Jasjeet S. Sekhon  

E-print Network

entirely on derivatives can be unreliable and often are virtually unusable. Newton-Raphson and quasi-Newton that combines evolutionary algorithm methods with a derivative-based, quasi-Newton method to solve difficult of GENOUD to that of the Gauss-Newton algorithm in SAS's PROC MODEL. #12;Introduction We report

Sekhon, Jasjeet S.

141

On the stability of J?-derivations  

NASA Astrophysics Data System (ADS)

In this paper, we establish the stability and superstability of J?-derivations in J?-algebras for the generalized Jensen-type functional equation rf({x+y}/{r})+rf({x-y}/{r})=2f(x). Finally, we investigate the stability of J?-derivations by using the fixed point alternative.

Eshaghi Gordji, M.; Ghaemi, M. B.; Kaboli Gharetapeh, S.; Shams, S.; Ebadian, A.

2010-03-01

142

ADIFOR --- Generating Derivative Codes from Fortran Programs  

Microsoft Academic Search

. The numerical methods employed in the solution of many scientific computing problems require the computationof derivatives of a function f : Rn!Rm. Both the accuracy and the computationalrequirements of the derivative computationare usually of critical importance for the robustness and speed of the numerical solution. ADIFOR (Automatic DifferentiationIn FORtran) is a source transformation tool that accepts Fortran 77 code

1991-01-01

143

Derivation of Refraction Formulas Paul S. Heckbert  

E-print Network

Derivation of Refraction Formulas Paul S. Heckbert ABSTRACT We derive three alternative formulas for the refracted ray direction in ray tracing in order to prove their equivalence and to demonstrate the process refract when they strike an interface between two different transpar­ ent media, such as air­water, air

Treuille, Adrien

144

17 CFR 200.507 - Declassification dates on derivative documents.  

Code of Federal Regulations, 2010 CFR

... false Declassification dates on derivative documents. 200.507 Section 200...200.507 Declassification dates on derivative documents. (a) A document...need for classification. (b) A derivative document that derives its...

2010-04-01

145

ADIFOR: Fortran source translation for efficient derivatives  

SciTech Connect

The numerical methods employed in the solution of many scientific computing problems require the computation of derivatives of a function f: R{sup n} {yields} R{sup m}. Both the accuracy and the computational requirements of the derivative computation are usually of critical importance for the robustness and speed of the numerical method. ADIFOR (Automatic Differentiation In FORtran) is a source translation tool implemented using the data abstractions and program analysis capabilities of the ParaScope Parallel Programming Environment. ADIFOR accepts arbitrary Fortran-77 code defining the computation of a function and writes portable Fortran-77 code for the computation of its derivatives. In contrast to previous approaches, ADIFOR views automatic differentiation as a process of source translation that exploits computational context to reduce the cost of derivative computations. Experimental results show that ADIFOR can handle real-life codes, providing exact derivatives with a running time that is competitive with the standard divided-difference approximations of derivatives and which may perform orders of magnitude faster than divided-differences in cases. The computational scientist using ADIFOR is freed from worrying about the accurate and efficient computation of derivatives, even for complicated functions,'' and hence, is able to concentrate on the more important issues of algorithm design or system modeling. 35 refs.

Bischof, C.; Corliss, G.; Griewank, A.; Hovland, P. (Argonne National Lab., IL (United States)); Carle, A. (Rice Univ., Houston, TX (United States). Center for Research on Parallel Computation)

1992-01-01

146

Risk management, derivatives and shariah compliance  

NASA Astrophysics Data System (ADS)

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.

Bacha, Obiyathulla Ismath

2013-04-01

147

Synthesis of new polysialic acid derivatives.  

PubMed

In this paper we report the first synthesis of novel polysialic acid derivatives which is initiated by treatment of polysialic acid with EDC-HCl to yield the inter-residual delta-lactone. Subsequent reaction with amines or hydrazine gives the corresponding polysialic acid amides and hydrazide. Alkylation of the tetrabutylammonium salt of polysialic acid yields polysialic acid esters. In contrast a variety of N-derivatives of polysialic acid can be prepared starting from deacetylated polysialic acid. The N-derivatives prepared in this communication can be used for the Cu-catalyzed as well as Cu-free "click" chemistry. PMID:20602419

Su, Yi; Kasper, Cornelia; Kirschning, Andreas; Dräger, Gerald; Berski, Silke

2010-09-01

148

The Theory of Quaternion Matrix Derivatives  

E-print Network

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.

Dongpo Xu; Danilo P. Mandic

2014-10-01

149

New fluorescent cytidine 5'-phosphate derivatives.  

PubMed Central

Interaction of cytidine 5'-phosphate with chloroacetone or p-tosyloxyacetone leads to 2-methyl-5,6-dihydro-5-oxo-6-(5-0-phospho-beta-D-ribofuranosyl)-imidazo/1,2-c/pyrimidine (2-methylethenocytidine 5'-phosphate) whereas analogous reaction with phenacyl bromide produces similar 2-phenyl-derivative. The bicyclic nucleotides obtained showed significant UV absorption at long wavelength where common nucleotides and proteins exhibited no absorption. These derivatives are highly fluorescent when heterocyclic ring is protonated. The absorption and fluorescent properties of the substituted ethenocytidine 5'-phosphoate derivatives seem to be suitable for their use as fluorescent probes or labels in biochemical studies. PMID:7772

Kochetkov, N K; Shibaev, V N; Kost, A A; Razjivin, A P; Borisov AYu

1976-01-01

150

Analysis and the Derivation of Valid Objectives  

ERIC Educational Resources Information Center

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)

Tiemann, Philip W.

1973-01-01

151

Tri and tetrahydroxycoumarin derivatives from Tetraphis pellucida  

Microsoft Academic Search

From gametophytes of Tetraphis pellucida have been isolated eight different tri- and tetrahydroxycoumarin derivatives; three of them are new natural products, the structures of which were elucidated spectroscopically. The taxonomic relevance of the results is discussed.

Marion Jung; Hans Geiger; Hans Dietmar Zinsmeister

1995-01-01

152

SCM Forcing Data Derived from NWP Analyses  

DOE Data Explorer

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.

Jakob, Christian

153

MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS  

EPA Science Inventory

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...

154

Phytol-Derived Novel Isoprenoid Immunostimulants  

PubMed Central

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

Chowdhury, Roshni Roy; Ghosh, Swapan K.

2012-01-01

155

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...

156

Superconformal Symmetry and Higher-Derivative Lagrangians  

NASA Astrophysics Data System (ADS)

Superconformal methods are useful to build invariant actions in supergravity. We have a good insight in the possibilities of actions that are at most quadratic in spacetime derivatives, but insight in general higher-derivative actions is missing. Recently higher-derivative actions got more attention for several applications. One of these is the understanding of finiteness of loop computations in supergravities. Divergences can only occur if invariant counterterms or anomalies exist. One can wonder whether conformal symmetry might also play a role in this context. In order to construct higher-derivative supergravities with the conformal methods, one should first get more insight in such rigid supersymmetric actions with extra fermionic symmetries. We show how Dirac-Born-Infeld actions with Volkov-Akulov supersymmetries can be constructed in all orders.

Van Proeyen, Antoine

157

45 CFR 601.5 - Derivative classification.  

Code of Federal Regulations, 2013 CFR

...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

2013-10-01

158

45 CFR 601.5 - Derivative classification.  

...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

2014-10-01

159

45 CFR 601.5 - Derivative classification.  

Code of Federal Regulations, 2012 CFR

...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

2012-10-01

160

45 CFR 601.5 - Derivative classification.  

Code of Federal Regulations, 2011 CFR

...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

2011-10-01

161

Concise Derivation of the Rotational Partition Function.  

ERIC Educational Resources Information Center

Derived is the classical partition function for the rotation of a rigid asymmetric molecule, by a transformation of variables in the phase integral circumventing the cumbersome manipulation of the canonical prescription. (Author/GA)

Hynne, F.; Andersen, Knud

1979-01-01

162

Real estate derivatives : products and prospects  

E-print Network

The paper reviews the development, structure and trade of past real estate equity hedging instruments. The reviewed products represent a wide array of real estate derivatives, covering multiple property types, index ...

Eisenberg, Oriel

2013-01-01

163

Direct synthesis of pyridine and pyrimidine derivatives  

E-print Network

I. Synthesis of Substituted Pyridine Derivatives via the Ruthenium-Catalyzed Cycloisomerization of 3-Azadienynes. The two-step conversion of various N-vinyl and N-aryl amides to the corresponding substituted pyridines and ...

Hill, Matthew D. (Matthew Dennis)

2008-01-01

164

45 CFR 601.5 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION...classified, and marking the newly developed material consistent with the marking of the...classification markings derived from source material or as directed by a classification...

2010-10-01

165

Conflicts of Interest in Derivatives Clearing  

Microsoft Academic Search

[Excerpt] The financial crisis implicated the over-the-counter (OTC) derivatives market as a source of systemic risk. In the wake of the crisis, lawmakers sought to reduce systemic risk to the financial system by regulating this market. One of the reforms that Congress introduced in the Dodd-Frank Act (P.L. 111-203) was mandatory clearing of OTC derivatives through clearinghouses, in an effort

Rena S Miller

2011-01-01

166

Synthesis and fungitoxicity of some pyrimidine derivatives  

Microsoft Academic Search

A series of 12 pyrimidine derivatives were prepared and tested in vitro against growth, sporulation and nucleic acids ofFusarium oxysporum f. sp.lycopersici andHelminthosporium oryzae. Introduction of thiazole ring together with two aryl groups to 2-aminopyrimidine induced drastic toxicity for both fungi.\\u000a Pyrimidine derivatives with aryl groups were less toxic. Nitro groups were found to enhance the toxicity of the pyrimidine

Salama A. Ouf; Sherif M. Sherif

1993-01-01

167

Synthesis and fungitoxicity of some pyrimidine derivatives  

Microsoft Academic Search

A series of 12 pyrimidine derivatives were prepared and testedin vitro against growth, sporulation and nucleic acid content ofFusarium oxysporum f. sp.lycopersici andHelminthosporium oryzae. Introduction of a thiazole ring together with two aryl groups into 2-aminopyrimidine brought about drastic toxicity for\\u000a both fungi. Pyrimidine derivatives with aryl groups alone were less toxic. Nitro groups were found to enhance the toxicity

S. A. Ouf; S. M. Sherif

1993-01-01

168

Derived categories and stacks in physics  

E-print Network

In this note we review how both derived categories and stacks enter physics. The physical realization of each has many formal similarities. For example, in both cases, equivalences are realized via renormalization group flow: in the case of derived categories, (boundary) renormalization group flow realizes the mathematical procedure of localization on quasi-isomorphisms, and in the case of stacks, worldsheet renormalization group flow realizes presentation-independence. For both, we outline current technical issues and applications.

E. Sharpe

2006-09-13

169

Siderophore production by marine-derived fungi  

Microsoft Academic Search

Siderophore production by marine-derived fungi has not been extensively explored. Three studies have investigated the ability\\u000a of marine-derived fungi to produce siderophores in response to iron limitation [(Vala et al. in Indian J Mar Sci 29:339–340,\\u000a 2000; Can J Microbiol 52:603–607, 2006); Baakza et al. in J Exp Mar Biol Ecol 311:1–9, 2004]. In all, 24 of 28 marine fungal

Brian Holinsworth; Jessica D. Martin

2009-01-01

170

Synthesis and antimycobacterial activity of calpinactam derivatives.  

PubMed

Synthesis of calpinactam 1, a fungal antimycobacterial metabolite, utilizing solid-phase peptide synthesis is described. To explore the structure-activity relationships of 1, its derivatives with different amino acids were also synthesized on the basis of the same synthetic strategy. These derivatives were examined for antimycobacterial activity against Mycobacterium smegmatis. Among them, only peptide 6d having d-Ala in place of d-Glu showed moderate activity. PMID:23116887

Nagai, Kenichiro; Koyama, Nobuhiro; Sato, Noriko; Yanagisawa, Chisato; Tomoda, Hiroshi

2012-12-15

171

Deriving Mathisson - Papapetrou equations from relativistic pseudomechanics  

E-print Network

It is shown that the equations of motion of a test point particle with spin in a given gravitational field, so called Mathisson - Papapetrou equations, can be derived from Euler - Lagrange equations of the relativistic pseudomechanics -- relativistic mechanics, which side by side uses the conventional (commuting) and Grassmannian (anticommuting) variables. In this approach the known difficulties of the Mathisson - Papapetrou equations, namely, the problem of the choice of supplementary conditions and the problem of higher derivatives are not appear.

R. R. Lompay

2005-03-12

172

New stilbene derivatives from Calligonum leucocladum.  

PubMed

Two new stilbene derivatives, (E)-resveratrol 3-(6' '-galloyl)-O-beta-D-glucopyranoside (1) and (E)-resveratrol 3-(4' '-acetyl)-O-beta-D-xylopyranoside (2), and five known stilbene derivatives (3-7) were isolated from the dried aerial parts of Calligonum leucocladum. Their structures were established on the basis of spectroscopic evidence. Compound 1 showed antioxidant activity and a restorative effect of the inhibition of oxacillin to oxacillin/methicillin-resistant Staphylococcus aureus. PMID:15217293

Okasaka, Mamoru; Takaishi, Yoshihisa; Kogure, Kentarou; Fukuzawa, Kenji; Shibata, Hirohumi; Higuti, Tomihiko; Honda, Gisho; Ito, Michiho; Kodzhimatov, Olimjon K; Ashurmetov, Ozodbek

2004-06-01

173

Iron coordination by catechol derivative antioxidants.  

PubMed

Iron complexes of nitrocatechols with different substituent groups [1: -CH = CR2; 2: -CH2-CHR2; 3: -CH = CR'(R")] were synthesized and their effects on iron-induced free radical reactions of biological importance investigated. Catechol and nitrocatechol derivatives effectively inhibited iron-induced lipid peroxide-dependent lipid peroxidation. In the Fenton-like reaction, iron-catechol generated hydroxyl radicals more strongly than did iron citrate, and iron-nitrocatechol derivative 2 generated a small amount of hydroxyl radicals. The iron complexes of derivatives 1 and 3 did not generate hydroxyl radicals. Iron-catechol had the highest ratio of reduction to oxidation rate constants and the second was iron-nitrocatechol 2, suggesting that iron chelated by nitrocatechols 1 and 3 may be most difficult to reduce. To elucidate the structure and physical properties of the iron complexes, UV/vis absorption spectroscopic, ESR and 1H NMR studies were performed in aqueous and DMSO solutions. In aqueous solution at pH 7.4, iron complexes of the nitrocatechol derivatives were high-spin tris(nitrocatecholato)ferrate(III) with a characteristic ligand-to-metal charge transfer absorbance (pi -> d pi). The lambda max of iron-nitrocatechol derivative 2 was shorter than those of iron-nitrocatechol derivatives 1 and 3, suggesting that the reduction potential of iron-nitrocatechol 2 is higher than that of iron-nitrocatechols 1 and 3. Nitrocatechol derivatives with a conjugation structure can sequester the chelated iron more effectively than catechol and the derivative without the conjugation against free radical generation by keeping the iron in the ferric state, probably because of the reduction potentials. PMID:8630099

Kawabata, T; Schepkin, V; Haramaki, N; Phadke, R S; Packer, L

1996-06-14

174

Crystallisation and crystal forms of carbohydrate derivatives  

NASA Astrophysics Data System (ADS)

This thesis is focused on the synthesis and solid state analysis of carbohydrate derivatives, including many novel compounds. Although the synthetic chemistry surrounding carbohydrates is well established in the literature, the crystal chemistry of carbohydrates is less well studied. Therefore this research aims to improve understanding of the solid state properties of carbohydrate derivatives through gaining more information on their supramolecular bonding. Chapter One focuses on an introduction to the solid state of organic compounds, with a background to crystallisation, including issues that can arise during crystal growth. Chapter Two is based on glucopyranuronate derivatives which are understudied in terms of their solid state forms. This chapter reports on the formation of novel glucuronamides and utilising the functionality of the amide bond for crystallisation. TEMPO oxidation was completed to form glucopyranuronates by oxidation of the primary alcohol groups of glucosides to the carboxylic acid derivatives, to increase functionality for enhanced crystal growth. Chapter Three reports on the synthesis of glucopyranoside derivatives by O-glycosylation reactions and displays crystal structures, including a number of previously unsolved acetate protected and deprotected crystal structures. More complex glycoside derivatives were also researched in an aim to study the resultant supramolecular motifs. Chapter Four contains the synthesis of aryl cellobioside derivatives including the novel crystal structures that were solved for the acetate protected and deprotected compounds. Research was carried out to determine if 1-deoxycellodextrins could act as putative isostructures for cellulose. Our research displays the presence of isostructural references with 1-deoxycellotriose shown to be similar to cellulose III11, 1-deoxycellotetraose correlates with cellulose IV11 and 1-deoxycellopentose shows isostructurality similar to that of cellulose II. Chapter Five contains the full experimental details and spectral characterisation of all novel compounds synthesised in this project and relevant crystallographic information.

Lennon, Lorna

175

Novel benzimidazole derivatives as expected anticancer agents.  

PubMed

A series of 1-(1H-benzimidazol-2-yl)-3-(substituted)-2-propen-1-one and its 1-methyl analogues 2c-h were synthesized and cyclized with different reagents such as ethyl cyanoacetate, thiourea, hydroxylamine hydrochloride, guanidinium sulfate, methylhydrazine, phenylhydrazine and/or hydrogen peroxide in different reactions to produce pyridones 3a,b, pyrimidinethione 4a,b, isoxazole 5a,b, aminopyrimidine 6a,b, pyrazoline 7i-k and epoxy derivative 8, respectively. Acetohydrazide 10 reacted with formic acid, acetic anhydride, carbon disulfide and/or thiosemicarbazide to yield compounds 11-19. Also compound 21a,b was condensed with different monosaccharides to yield the corresponding N-glycoside Schiff's bases derivatives 22a-h, which upon treatment with acetic anhydride afforded 23a-h derivatives. The anticancer activity of some of the newly synthesized compounds was evaluated against HEPG2 (human liver carcinoma cell line) and PC12 (pheochromocytoma of the rat adrenal medulla) cells. Benzimidazole-2-isoxazole 5a derivative exhibited high potency against HEPG2 and PC12 cells. Benzimidazole chalcones 2c,e, benzimidazole mercaptoacetohydrazide 14 and benzimidazole thiosemicarbazide 15a,b derivatives gave high potency against PC12 cells. PMID:21796934

Nofal, Zienab M; Soliman, Elsyed A; Abd El-Karim, Somaia S; El Zahar, Magdy I; Srour, Aladdin M; Sethumadhavan, Shalini; Maher, Timothy J

2011-01-01

176

Deriving Framework Usages Based on Behavioral Models  

NASA Astrophysics Data System (ADS)

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.

Zenmyo, Teruyoshi; Kobayashi, Takashi; Saeki, Motoshi

177

Structure activity relationship of brevenal hydrazide derivatives.  

PubMed

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

Goodman, Allan; McCall, Jennifer R; Jacocks, Henry M; Thompson, Alysha; Baden, Daniel; Abraham, William M; Bourdelais, Andrea

2014-04-01

178

New steroid derivative with hypoglycemic activity  

PubMed Central

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.

Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Lenin, Hau-Heredia; Elodia, García-Cervera; Eduardo, Pool-Gómez; Marcela, Rosas-Nexticapa; Bety, Sarabia-Alcocer

2014-01-01

179

Derivation of Completely Cell Culture-Derived Mice from Early-Passage Embryonic Stem Cells  

Microsoft Academic Search

Several newly generated mouse embryonic stem (ES) cell lines were tested for their ability to produce completely ES cell-derived mice at early passage numbers by ES cell leftrightarrow tetraploid embryo aggregation. One line, designated R1, produced live offspring which were completely ES cell-derived as judged by isoenzyme analysis and coat color. These cell culture-derived animals were normal, viable, and fertile.

Andras Nagy; Janet Rossant; Reka Nagy; Wanda Abramow-Newerly; John C. Roder

1993-01-01

180

Annihilation-Derivative, Creation-Derivative and Representation of Quantum Martingales  

Microsoft Academic Search

On the basis of the quantum white noise theory we introduce the notion of creation- and annihilation-derivatives of Fock space\\u000a operators and study the differentiability of white noise operators. We define the Hitsuda–Skorohod quantum stochastic integrals\\u000a by the adjoint actions of quantum stochastic gradients and show explicit formulas for their creation- and annihilation-derivatives.\\u000a As an application, we derive direct formulas

Un Cig Ji; Nobuaki Obata

2009-01-01

181

Second derivatives for approximate spin projection methods.  

PubMed

The use of broken-symmetry electronic structure methods is required in order to obtain correct behavior of electronically strained open-shell systems, such as transition states, biradicals, and transition metals. This approach often has issues with spin contamination, which can lead to significant errors in predicted energies, geometries, and properties. Approximate projection schemes are able to correct for spin contamination and can often yield improved results. To fully make use of these methods and to carry out exploration of the potential energy surface, it is desirable to develop an efficient second energy derivative theory. In this paper, we formulate the analytical second derivatives for the Yamaguchi approximate projection scheme, building on recent work that has yielded an efficient implementation of the analytical first derivatives. PMID:25662635

Thompson, Lee M; Hratchian, Hrant P

2015-02-01

182

Synthesis and properties of novel psoralen derivatives  

SciTech Connect

The authors have synthesized a set of new trimethylpsoralen derivatives that are characterized by a chain extending from the 4'-position of the furan ring and linked to this ring by an aminomethylene group. The nature of the side chain can be varied widely. In these derivatives, the chains contain either amino or ethylene oxide units for enhanced water solubility and allow the introduction of a thiol or amine group to nucleic acids. These compounds represent the first set of thiolated psoralen derivatives, and their usefulness is demonstrated in several nucleic acid cross-linking experiments. The reagents can be used to create both intraduplex reversible cross-links between the two single-strand partners in a DNA double helix and interduplex reversible cross-links between two DNA double helices.

Goldenberg, M.; Welsh, J.; Haas, R.; Rideout, D.C.; Cantor, C.R.

1988-09-06

183

Gateaux and Frechet Derivative in Intuitionistic Fuzzy Normed Linear spaces  

E-print Network

Intuitionistic Fuzzy derivative, Intuitionistic Fuzzy Gateaux derivative, Intuitionistic Fuzzy Fr\\'{e}chet derivative are defined and a few of their properties are studied. The relation between Intuitionistic Fuzzy Gateaux derivative and Intuitionistic Fuzzy Fr\\'{e}chet derivative are emphasized.

B. Dinda; T. K. Samanta; U. K. Bera

2010-09-11

184

Talbot interferometer for radial and lateral derivatives.  

PubMed

The theory and experimental evidence of a shearing interferometer based on the Talbot effect are presented. Multiple-shearing interferences are obtained that can be reduced to triple-shearing or doubleshearing interferences by the addition of simple spatial filtering. When the shear is less than the width of the details in the object, these interferences become either the second or first derivative of the object under test, respectively. Either lateral or constant radial shear can be introduced by choosing Ronchi rulings or circular gratings. Thus both lateral and radial derivatives are easily obtained. If white light is used as a source, color fringes of high contrast are observed. PMID:20119380

Silva, D E

1972-11-01

185

Special Relativity Derived from Spacetime Magma  

PubMed Central

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 and Euclidean 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 -algebras more generally. PMID:24959889

Greensite, Fred

2014-01-01

186

Geometric derivation of the quantum speed limit  

SciTech Connect

The Mandelstam-Tamm and Margolus-Levitin inequalities play an important role in the study of quantum-mechanical processes in nature since they provide general limits on the speed of dynamical evolution. However, to date there has been only one derivation of the Margolus-Levitin inequality. In this paper, alternative geometric derivations for both inequalities are obtained from the statistical distance between quantum states. The inequalities are shown to hold for unitary evolution of pure and mixed states, and a counterexample to the inequalities is given for evolution described by completely positive trace-preserving maps. The counterexample shows that there is no quantum speed limit for nonunitary evolution.

Jones, Philip J.; Kok, Pieter [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2010-08-15

187

Monoterpene citral derivatives as potential antimalarials.  

PubMed

Conjugated acid derivatives containing nitrogen have been synthesized from the simple acyclic monoterpene citral, using various reactions, including Wittig, Baylis Hillman, amide and ester condensations. Similarly, amine peroxides were synthesized by subjecting citral to Mannich type reaction with amines and t-butyl hydroperoxide. Molecules 3-10 were evaluated for antimalarial activity against erythrocytic stages of chloroquine sensitive P. falciparum strain 3D7. Four derivatives displayed interesting activity with an IC50< 2.5 microM, and warrant further investigations. PMID:24689199

Singh, Soni; Khandare, Reena P; Sharma, Manish; Bhasin, Virendra K; Bhat, Sujata V

2014-03-01

188

High ethanol producing derivatives of Thermoanaerobacter ethanolicus  

DOEpatents

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).

Ljungdahl, L.G.; Carriera, L.H.

1983-05-24

189

Elevation Derivatives for Mojave Desert Tortoise Habitat  

USGS Publications Warehouse

This report describes the methods used to derive various elevation-derivative grids that were inputted to the Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness and topographic characteristics, are a subset of the environmental datasets evaluated for the tortoise habitat model. This habitat model is of major importance to the U.S. Fish and Wildlife Service, which is charged with management of this threatened population, including relocating displaced tortoises to areas identified as suitable habitat.

Wallace, Cynthia S.A.; Gass, Leila

2008-01-01

190

Special relativity derived from spacetime magma.  

PubMed

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

Greensite, Fred

2014-01-01

191

Vitamin B12 derivatives for orthogonal functionalization.  

PubMed

The synthesis of vitamin B12 derivatives for selective orthogonal conjugation at both the Co center and 5'-OH is reported. Newly developed, reduction-free, direct alkynylation of vitamin B12 at the central cobalt ion proved to be versatile, with the formed acetylides, unlike other metalloorganic derivatives, showing remarkable heat and light stability, thus making them promising candidates as a drug carrier. Subsequently, high-yielding functionalization can be achieved via a sequence of selective [1,3] dipolar azide-alkyne cycloadditions (AACs) or carbamate formation followed by AAC. PMID:25046078

Chromi?ski, Miko?aj; Lewalska, Agnieszka; Karczewski, Maksymilian; Gryko, Dorota

2014-08-15

192

SYNTHESIS AND CHARACTERIZATION OF SOME ORGANIC CARBONATES DERIVED FROM VEGETABLE OILS AND THEIR DERIVATIVES  

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 ...

193

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2013-07-01

194

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2011-07-01

195

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

...2014-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2014-07-01

196

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2012-07-01

197

Barriers to growth in the US real estate derivatives market  

E-print Network

Commercial real estate is an important asset class but it does not yet have a well-developed derivatives market in the United States. A derivative is a contract that derives its value from an underlying index or asset. ...

Venter, Jani

2007-01-01

198

75 FR 78185 - Information Management Requirements for Derivatives Clearing Organizations  

Federal Register 2010, 2011, 2012, 2013

...Information Management Requirements for Derivatives Clearing Organizations AGENCY: Commodity...implement certain core principles for derivatives clearing organizations (DCOs) as amended...execution requirements on standardized derivative products; (3) creating...

2010-12-15

199

78 FR 66639 - Modifications of Certain Derivative Contracts  

Federal Register 2010, 2011, 2012, 2013

...1545-BK13 Modifications of Certain Derivative Contracts AGENCY: Internal Revenue...the transfer or assignment of certain derivative contracts. The final regulations provide...to the nonassigning counterparty to a derivative contract and an assignee on...

2013-11-06

200

76 FR 51878 - Modifications of Certain Derivative Contracts; Correction  

Federal Register 2010, 2011, 2012, 2013

...1545-BK14 Modifications of Certain Derivative Contracts; Correction AGENCY: Internal...a transfer or assignment of certain derivative contracts does not result in an exchange...1001-4T Modifications of certain derivative contracts...

2011-08-19

201

40 CFR 721.1760 - Substituted benzotriazole derivatives.  

Code of Federal Regulations, 2010 CFR

... false Substituted benzotriazole derivatives. 721.1760 Section 721.1760...721.1760 Substituted benzotriazole derivatives. (a) Chemical substances and significant...generically as substituted benzotriazole derivatives (PMNs P-93-374 and...

2010-07-01

202

17 CFR 229.1115 - (Item 1115) Certain derivatives instruments.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false (Item 1115) Certain derivatives instruments. 229.1115 Section 229... § 229.1115 (Item 1115) Certain derivatives instruments. This item relates to derivative instruments, such as interest...

2010-04-01

203

14 CFR 1203.501 - Applying derivative classification markings.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Applying derivative classification markings. 1203.501...ADMINISTRATION INFORMATION SECURITY PROGRAM Derivative Classification § 1203.501 Applying derivative classification markings. Persons...

2010-01-01

204

76 FR 51878 - Modifications of Certain Derivative Contracts; Correction  

Federal Register 2010, 2011, 2012, 2013

...1545-BK14 Modifications of Certain Derivative Contracts; Correction AGENCY: Internal...a transfer or assignment of certain derivative contracts does not result in an exchange...clearinghouse transfers or assigns a derivative contract to another dealer in...

2011-08-19

205

76 FR 43957 - Modifications of Certain Derivative Contracts  

Federal Register 2010, 2011, 2012, 2013

...1545-BK13 Modifications of Certain Derivative Contracts AGENCY: Internal Revenue...when there is an assignment of certain derivative contracts. The text of those regulations...that the transfer or assignment of a derivative contract in certain situations is...

2011-07-22

206

40 CFR 721.646 - Aminofluoran derivative (generic name).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Aminofluoran derivative (generic name). 721.646 Section...Substances § 721.646 Aminofluoran derivative (generic name). (a) Chemical...identified generically as aminofluoran derivative (PMN P-95-512) is subject...

2010-07-01

207

40 CFR 721.9740 - Brominated triazine derivative.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Brominated triazine derivative. 721.9740 Section 721.9740... § 721.9740 Brominated triazine derivative. (a) Chemical substance and significant...generically as a brominated triazine derivative (PMN P-91-403) is subject...

2010-07-01

208

14 CFR 1203.500 - Use of derivative classification.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Use of derivative classification. 1203.500 Section...ADMINISTRATION INFORMATION SECURITY PROGRAM Derivative Classification § 1203.500 Use of derivative classification. The...

2010-01-01

209

18 CFR 367.1750 - Account 175, Derivative instrument assets.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Account 175, Derivative instrument assets. 367.1750...Assets § 367.1750 Account 175, Derivative instrument assets. This account must include the amounts paid for derivative instruments, and the change...

2010-04-01

210

76 FR 43892 - Modifications of Certain Derivative Contracts  

Federal Register 2010, 2011, 2012, 2013

...1545-BK14 Modifications of Certain Derivative Contracts AGENCY: Internal Revenue...a transfer or assignment of certain derivative contracts does not result in an exchange...necessitate the movement of entire books of derivative contracts. In particular, there...

2011-07-22

211

40 CFR 721.10172 - Alkylamide derivative (generic).  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Alkylamide derivative (generic). 721.10172 Section...Substances § 721.10172 Alkylamide derivative (generic). (a) Chemical substance...identified generically as alkylamide derivative (PMN P-03-633) is subject...

2010-07-01

212

17 CFR 240.16a-4 - Derivative securities.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Derivative securities. 240.16a-4 ...Securities Dealers § 240.16a-4 Derivative securities. (a) For purposes of section 16 of the Act, both derivative securities and the...

2010-04-01

213

40 CFR 721.9079 - Dihydro quinacridone derivative (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dihydro quinacridone derivative (generic). 721.9079 Section... § 721.9079 Dihydro quinacridone derivative (generic). (a) Chemical substance...identified generically as dihydro quinacridone derivative (PMN P-01-397) is subject...

2010-07-01

214

40 CFR 721.5925 - Bis heterocyclic phenylene derivative (generic).  

Code of Federal Regulations, 2010 CFR

... false Bis heterocyclic phenylene derivative (generic). 721.5925 Section...5925 Bis heterocyclic phenylene derivative (generic). (a) Chemical substance...generically as bis heterocyclic phenylene derivative (PMN P-01-0432) is subject...

2010-07-01

215

18 CFR 367.2440 - Account 244, Derivative instrument liabilities.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Account 244, Derivative instrument liabilities. 367.2440...Liabilities § 367.2440 Account 244, Derivative instrument liabilities. This account...the change in the fair value of all derivative instrument liabilities not...

2010-04-01

216

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2010 CFR

... Substituted phenylimino carbamate derivative. 721.2025 Section 721.2025... Substituted phenylimino carbamate derivative. (a) Chemical substance and significant...as a substituted phenylimino carbamate derivative (PMN P-91-487) is subject...

2010-07-01

217

Two-sided discrete fractional derivatives and systems  

NASA Astrophysics Data System (ADS)

Starting from the discrete-time nabla (forward) and delta (backward) derivatives we introduce a two-sided derivative valid for any order. Its eigenfunction is the normal discrete exponential. This derivative leads to discrete non causal linear systems.

Ortigueira, Manuel D.

2012-09-01

218

Nonlinear Frechet derivative and its De Wolf approximation  

E-print Network

We introduce and derive the nonlinear Frechet derivative for the acoustic wave equation. It turns out that the high order Frechet derivatives can be realized by consecutive applications of the scattering operator and a ...

Wu, Ru-Shan

2012-01-01

219

Tectonic plate motions derived from Lageos  

Microsoft Academic Search

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

R. Biancale; A. Cazenave; K. Dominh

1991-01-01

220

Deriving Production Rules for Incremental View Maintenance  

Microsoft Academic Search

. It is widely recognized that production rules indatabase systems can be used to automatically maintain deriveddata such as views. However, writing a correct set ofrules for efficiently maintaining a given view can be a difficultand ad-hoc process. We provide a facility whereby a userdefines a view as an SQL select expression, from which thesystem automatically derives set-oriented production rulesthat

Stefano Ceri; Jennifer Widom

1991-01-01

221

Derivation of physically motivated wind speed scales  

Microsoft Academic Search

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

Nikolai Dotzek

2009-01-01

222

CORRESPONDENCE Brain-Derived Neurotrophic Factor, Serotonin  

E-print Network

on Kaufman et al. To the Editor: Brain-derived neurotrophic factor (BDNF) and serotonin transporter (SERT-like behavior in animals (Berton et al. 2006). A recent study has examined BDNF/SERT genes interactions in depressed children, reporting that a combination of met-BDNF allele with two short SERT alleles

Kalueff, Allan V.

223

Curcumin derivatives as HIV-1 protease inhibitors  

SciTech Connect

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.

Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

1993-12-31

224

Emulating Multivariate Output with Derivative Information  

E-print Network

Emulating Multivariate Output with Derivative Information Gemma Stephenson, James Gattiker with a computationally expensive model. Hence an emulator, which is a statistical approximator to the simulator, can model and the emulator is built based on data collected from running the simulator at a specified, small

Oakley, Jeremy

225

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...

226

DAMTP 9269 Grassmann Mechanics, Multivector Derivatives and  

E-print Network

DAMTP 92­69 Grassmann Mechanics, Multivector Derivatives and Geometric Algebra \\Lambda Chris Doran of incorporating the results of Grassmann calculus within the framework of geometric algebra is presented symmetry groups, can be expressed purely in terms of the real geometric algebras of space and spacetime

Cambridge, University of

227

Deriving Safety Requirements Using Scenarios Karen Allenby  

E-print Network

Deriving Safety Requirements Using Scenarios Karen Allenby University of York Department.kelly@cs.york.ac.uk Abstract Elicitation of requirements for safety critical aero- engine control systems is dependent deviations from that intent. Deriva- tion of these requirements is inextricably linked to the safety

Kelly, Tim

228

Derivatives and the Graphs of Functions Microworld  

NSDL National Science Digital Library

The purpose of this Microworld is to experiment with some of the general applications of the derivative to the study of the behavior of functions. This includes their critical behavior, their local extrema, regions of monotonicity (increasing or decreasing), and their inflection points.

White, James

2004-11-01

229

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...

230

High speed point derivative microseismic detector  

DOEpatents

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.

Uhl, James Eugene (Albuquerque, NM); Warpinski, Norman Raymond (Albuquerque, NM); Whetten, Ernest Blayne (Albuquerque, NM)

1998-01-01

231

High speed point derivative microseismic detector  

DOEpatents

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.

Uhl, J.E.; Warpinski, N.R.; Whetten, E.B.

1998-06-30

232

78 FR 76787 - Position Limits for Derivatives  

Federal Register 2010, 2011, 2012, 2013

...FUTURES TRADING COMMISSION 17 CFR Parts 1, 15, 17, 19, 32, 37, 38, 140 and 150 RIN 3038-AD99 Position Limits for Derivatives Correction In proposed rule document 2013-27200 appearing on pages 75679 through 75842 in the issue of Thursday,...

2013-12-19

233

Enhancing Knowledge Mapping Using Automatically Derived Concepts  

E-print Network

to obtain a cor- rectly spelled word. Compound contraction. The orthography of new, domain specific compound.g. "domain name", whereas Dutch and German contract constituent words "domainname". Compounds are easy all possible word orders of compound terms in the ontol- ogy and derive a pattern by inserting a near

Anjewierden, Anjo

234

Geometric Derivation of Radial Acceleration Magnitude.  

ERIC Educational Resources Information Center

Standard treatments of uniform circular motion generally employ a combination of geometric and kinematic arguments to obtain the magnitude of radial acceleration. Presents a novel approach to the geometric portion of the derivation that uses the property that vectors can be translated parallel to themselves. (JRH)

Kraft, David W.; Motz, Lloyd

1995-01-01

235

Deriving a Pedagogy of Educational Foundations  

ERIC Educational Resources Information Center

This sixth and last paper in the series describes four elements believed to be crucial to a high quality pedagogy for educational foundations. These four elements are derived from a close reading of the previous papers. The work of Osguthorpe, Sanger, Haniford, and Mucher, four of the authors in this series, is cited as both a source for these…

Fenstermacher, Gary D.

2007-01-01

236

Derived Transformation of Children's Pregambling Game Playing  

ERIC Educational Resources Information Center

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…

Dymond, Simon; Bateman, Helena; Dixon, Mark R.

2010-01-01

237

Leading Edge Democracy Derived? New Trajectories  

E-print Network

Leading Edge Commentary Democracy Derived? New Trajectories in Pluripotent Stem Cell Research of stem cell research? Here, coauthorship networks of stem cell research articles and analysis of cell lines used in stem cell research indicate that hiPSCs are not replacing human embryonic stem cells

238

Four new hemiterpenoid derivatives from Taxillus chinensis.  

PubMed

Four new hemiterpenoid derivatives, taxilluside A-D (1-4), were isolated from the branches and leaves of Taxillus chinensis (DC.) Danser. Their structures were determined on the basis of spectroscopic analysis. Of these compounds, compounds 3 and 4 showed inhibition activity on Calcium concentration in myocardial cells evaluated by measuring the changes of fluorescence signal using Laser scanning confocal microscope. PMID:23376411

Ding, Bo; Dai, Yi; Hou, Yun-Long; Wu, Xiao-Meng; Chen, Xue; Yao, Xin-Sheng

2013-04-01

239

Radon-Nikodym Derivatives of Gaussian Measures  

Microsoft Academic Search

We give simple necessary and sufficient conditions on the mean and covariance for a Gaussian measure to be equivalent to Wiener measure. This was formerly an unsolved problem [26]. An unsolved problem is to obtain the Radom-Nikodym derivative $d\\\\mu\\/d\\\

L. A. Shepp

1966-01-01

240

Singlet exciton fission in a hexacene derivative.  

PubMed

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

Lee, Jiye; Bruzek, Matthew J; Thompson, Nicholas J; Sfeir, Matthew Y; Anthony, John E; Baldo, Marc A

2013-03-13

241

New sulphide derivative from Ferula rutabensis  

Microsoft Academic Search

Reinvestigation of CH2Cl2 extract of roots and rhizomes of Ferula rutabensis led to the isolation of a new trisulphide (1) and phthalic acid derivative (2). Their characterisation was based on their spectral data, including MS, 1D- and 2D-NMR.

Essam Abdel-Sattar; Sahar El-Mekkawy

2009-01-01

242

Sol-Gel Derived Hafnia Coatings  

NASA Technical Reports Server (NTRS)

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.

Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

2002-01-01

243

Communication The monitoring of bovine pregnancies derived  

E-print Network

/ embryo transfer / in vitro fertilization / nuclear transfer Reprod. Nutr. Dev. 42 (2002) 613­624 613Communication The monitoring of bovine pregnancies derived from transfer of in vitro produced are associated with bovine pregnancies obtained from in vitro produced embryos. This thus requires for a more

Paris-Sud XI, Université de

244

Biofuels and bio-products derived from  

E-print Network

NEED Biofuels and bio- products derived from lignocellulosic biomass (plant materials) are part improve the energy and carbon efficiencies of biofuels production from a barrel of biomass using chemical and thermal catalytic mechanisms. The Center for Direct Catalytic Conversion of Biomass to Biofuels IMPACT

Ginzel, Matthew

245

Alternative Derivations for the Poisson Integral Formula  

ERIC Educational Resources Information Center

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…

Chen, J. T.; Wu, C. S.

2006-01-01

246

On the logarithm of the derivative operator  

E-print Network

We study the properties of the logarithm of the derivative operator and show that its action on a constant is not zero, but yields the sum of the logarithmic function and the Euler-Mascheroni constant. We discuss more general aspects concerning the logarithm of an operator for the study of the properties of the Bessel functions.

Babusci, D

2011-01-01

247

On the logarithm of the derivative operator  

E-print Network

We study the properties of the logarithm of the derivative operator and show that its action on a constant is not zero, but yields the sum of the logarithmic function and the Euler-Mascheroni constant. We discuss more general aspects concerning the logarithm of an operator for the study of the properties of the Bessel functions.

D. Babusci; G. Dattoli

2011-05-30

248

ERRATUM: Frechet derivatives in inverse obstacle scattering  

Microsoft Academic Search

There is an error in theorem 2.1 of this paper, which shows a representation of the Frchet derivative with respect to the boundary of the far field operator from scattering by obstacles with Robin boundary conditions. The boundary condition in equation (2.4) has to be replaced by where H denotes the mean curvature of the boundary. The error occurs in

Frank Hettlich

1998-01-01

249

Root coverage with enamel matrix derivatives.  

PubMed

Different root coverage procedures have been used to treat cases of gingival recession defects involving single or multiple exposed root surfaces. A therapeutic advantage may be gained if periodontal regeneration is obtained in addition to coverage of the root with gingiva. This article describes the treatment of gingival recession by combining a surgical technique with an enamel matrix derivative. PMID:12365135

Chen, Leon; Cha, Jennifer; Guiha, Rami; Bouwsma, Otis J

2002-09-01

250

Higher and derived stacks: a global overview  

Microsoft Academic Search

These are expended notes of my talk at the summer institute in algebraic geometry (Seattle, July-August 2005), whose main purpose is to present a global overview on the theory of higher and derived stacks. This text is far from being exhaustive but is intended to cover a rather large part of the subject, starting from the motivations and the foundational

Bertrand Toen

2006-01-01

251

Two-point derivative dispersion relations  

NASA Astrophysics Data System (ADS)

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.

Ferreira, Erasmo; Sesma, Javier

2013-03-01

252

Synthesis of hydroxy derivatives of limonene  

NASA Astrophysics Data System (ADS)

Synthetic routes to mono-, di- and trihydroxy derivatives of limonene are presented. Emphasis is given to the problems of regio- and stereoselectivity of transformations. Data on the isolation from natural sources and on the biological activities of the title compounds are given. The bibliography includes 107 references.

Ardashov, O. V.; Volcho, K. P.; Salakhutdinov, N. F.

2014-04-01

253

Study on resist performance of chemically amplified molecular resist based on noria derivative and calixarene derivative  

NASA Astrophysics Data System (ADS)

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.

Yamamoto, Hiroki; Kudo, Hiroto; Kozawa, Takahiro

2014-03-01

254

Familial Follicular Cell-Derived Thyroid Carcinoma  

PubMed Central

Follicular cell-derived well-differentiated thyroid cancer, papillary (PTC) and follicular thyroid carcinomas comprise 95% of all thyroid malignancies. Familial follicular cell-derived well-differentiated thyroid cancers contribute 5% of cases. Such familial follicular cell-derived carcinomas or non-medullary thyroid carcinomas (NMTC) are divided into two clinical–pathological groups. The syndromic-associated group is composed of predominately non-thyroidal tumors and includes Pendred syndrome, Warner syndrome, Carney complex (CNC) type 1, PTEN-hamartoma tumor syndrome (PHTS; Cowden disease), and familial adenomatous polyposis (FAP)/Gardner syndrome. Other conditions with less established links to the development of follicular cell-derived tumors include ataxia–telangiectasia syndrome, McCune Albright syndrome, and Peutz–Jeghers syndrome. The final group encompasses syndromes typified by NMTC, as well as pure familial (f) PTC with or without oxyphilia, fPTC with multinodular goiter, and fPTC with papillary renal cell carcinoma. This heterogeneous group of diseases does not have the established genotype–phenotype correlations known as in the familial C-cell-derived tumors or medullary thyroid carcinomas (MTC). Clinicians should have the knowledge to identify the likelihood of a patient presenting with thyroid cancer having an additional underlying familial syndrome stemming from characteristics by examining morphological findings that would alert pathologists to recommend that patients undergo molecular genetic evaluation. This review discusses the clinical and pathological findings of patients with familial PTC, such as FAP, CNC, Werner syndrome, and Pendred syndrome, and the heterogeneous group of familial PTC. PMID:22654876

Son, Eun Ju; Nosé, Vânia

2012-01-01

255

Neuroprotective Properties of Chitosan and Its Derivatives  

PubMed Central

Neuronal cells are extremely vulnerable and have a limited capacity for self-repair in response to injury. For those reasons, there is obvious interest in limiting neuronal damage. Mechanisms and strategies used in order to protect against neuronal injury, apoptosis, dysfunction, and degeneration in the central nervous system are recognized as neuroprotection. Neuroprotection could be achieved through several classes of natural and synthetic neuroprotective agents. However, considering the side effects of synthetic neuroprotective agents, the search for natural neuroprotective agents has received great attention. Recently, an increasing number of studies have identified neuroprotective properties of chitosan and its derivatives; however, there are some significant challenges that must be overcome for the success of this approach. Hence, the objective of this review is to discuss neuroprotective properties of chitosan and its derivatives. PMID:20714426

Pangestuti, Ratih; Kim, Se-Kwon

2010-01-01

256

Antitumor Activity of Bis-Indole Derivatives  

PubMed Central

This paper reports the synthesis of compounds formed by two indole systems separated by a heterocycle (pyridine or piperazine). As a primary screening, the new compounds were submitted to the National Cancer Institute for evaluation of antitumor activity in the human cell line screen. The pyridine derivatives were far more active than the piperazine derivatives. For the study of the mechanism of action, the most active compounds were subjected to COMPARE analysis and to further biological tests including proteasome inhibition and inhibition of plasma membrane electron transport. The compound bearing the 5-methoxy-2-indolinone moiety was subjected to the first in vivo experiment (hollow fiber assay) and was active. It was therefore selected for the second in vivo experiment (human tumor xenograft in mice). In conclusion we demonstrated that this approach was successful since some of the compounds described are much more active than the numerous, so far prepared and tested 3-indolylmethylene-2-indolinones. PMID:18598018

Andreani, Aldo; Burnelli, Silvia; Granaiola, Massimiliano; Leoni, Alberto; Locatelli, Alessandra; Morigi, Rita; Rambaldi, Mirella; Varoli, Lucilla; Landi, Laura; Prata, Cecilia; Berridge, Michael V.; Grasso, Carole; Fiebig, Heinz-Herbert; Kelter, Gerhard; Burger, Angelika M.; Kunkel, Mark W.

2009-01-01

257

Mechanical properties of titania-derived nanoribbons  

NASA Astrophysics Data System (ADS)

The mechanical properties of TiO2-derived nanoribbons were investigated by using a three-point bending method. Thin nanoribbons (cross-section dimension ~30 nm) have an average Young's modulus of 260 ± 55 GPa. For thicker nanoribbons, which are composed of several thinner nanostrips, the bending modulus rapidly decreases with increasing cross-section. In analogy with carbon nanotube ropes we argue that shear deformations become important and the shear modulus is G = 0.07-0.4 GPa. The present results together with our previous work suggest that TiO2-derived nanoribbons and nanotubes may undertake a dual function in polymer composites: they could reinforce the polymer matrix while at the same time they could provide a large active surface area.

Humar, M.; Arcon, D.; Umek, P.; Skarabot, M.; Musevic, I.; Bregar, G.

2006-08-01

258

Bacterial degradation of chlorophenols and their derivatives  

PubMed Central

Chlorophenols (CPs) and their derivatives are persistent environmental pollutants which are used in the manufacture of dyes, drugs, pesticides and other industrial products. CPs, which include monochlorophenols, polychlorophenols, chloronitrophenols, chloroaminophenols and chloromethylphenols, are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Several physico-chemical and biological methods have been used for removal of CPs from the environment. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing CPs from the environment. Several bacteria that use CPs as their sole carbon and energy sources have been isolated and characterized. Additionally, the metabolic pathways for degradation of CPs have been studied in bacteria and the genes and enzymes involved in the degradation of various CPs have been identified and characterized. This review describes the biochemical and genetic basis of the degradation of CPs and their derivatives. PMID:24589366

2014-01-01

259

Fatty acid-derived signals in plants.  

PubMed

Plants synthesize many fatty acid derivatives, several of which play important regulatory roles. Jasmonates are the best characterized examples. Jasmonate-insensitive mutants and mutants with a constitutive jasmonate response have given us new insights into jasmonate signalling. The jasmonate biosynthesis mutant opr3 allowed the dissection of cyclopentanone and cyclopentenone signalling, thus defining specific roles for these molecules. Jasmonate signalling is a complex network of individual signals and recent findings on specific activities of methyl jasmonate and (Z)-jasmone add to this picture. In addition, there are keto, hydroxy and hydroperoxy fatty acids that might be involved in cell death and the expression of stress-related genes. Finally, there are bruchins and volicitin, signal molecules from insects that are perceived by plants in the picomole to femtomole range. They highlight the importance of fatty acid-derived molecules in interspecies communication and in plant defence. PMID:11992827

Weber, Hans

2002-05-01

260

Inequalities for a polynomial and its derivative  

NASA Astrophysics Data System (ADS)

Let , 1[less-than-or-equals, slant][mu][less-than-or-equals, slant]n, be a polynomial of degree n such that p(z)[not equal to]0 in z0, then for 0derivative, Math. Inequal. Appl. 2 (2) (1999) 203-205] proved Equality holds for the polynomial where n is a multiple of [mu]E In this paper, we obtain an improvement of the above inequality by involving some of the coefficients. As an application of our result, we further improve upon a result recently proved by Aziz and Shah [A. Aziz, W.M. Shah, Inequalities for a polynomial and its derivative, Math. Inequal. Appl. 7 (3) (2004) 379-391].

Chanam, Barchand; Dewan, K. K.

2007-12-01

261

Tooth-derived bone graft material  

PubMed Central

With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth. PMID:24471027

Kim, Young-Kyun; Lee, Junho; Kim, Kyung-Wook; Murata, Masaru; Akazawa, Toshiyuki; Mitsugi, Masaharu

2013-01-01

262

Dimeric cinnamoylamide derivatives as inhibitors of melanogenesis.  

PubMed

Dimeric cinnamoylamide derivatives were synthetized and tested as inhibitors of tyrosinase activity and melanin formation. The most active dimeric cinnamoylamide derivatives was dimeric compound of p-coumaric acid (compound 1) that inhibited tyrosinase activity more efficiently than p-coumaric acid. It also inhibited melanin production by B16 melanoma cell line and normal human melanocytes more efficiently than kojic acid. We next investigated the potential mutagenic and skin sensitization effect of compound 1. Compound 1 was found to induce no mutagenic activity, no irritation and no delayed contact hypersensitivity at the maximum concentration of 10%. In vitro percutaneous absorption studies exhibited that compound 1 could diffuse across the skin till its site of action. All these results lead us to propose that compound 1 may be a safe and effective candidate for treating skin hyperpigmentation related disorders. PMID:21372395

Criton, Marc; Le Mellay-Hamon, Véronique

2011-01-01

263

Scalar wormholes with nonminimal derivative coupling  

NASA Astrophysics Data System (ADS)

We consider static spherically symmetric wormhole configurations in a gravitational theory of a scalar field with a potential V(?) and nonminimal derivative coupling to the curvature described by the term (?g?? + ?G??)?, ??, ? in the action. We show that the flare-out conditions providing the geometry of a wormhole throat could be fulfilled both if ? = -1 (phantom scalar) and ? = +1 (ordinary scalar). Supposing additionally a traversability, we construct numerical solutions describing traversable wormholes in the model with arbitrary ?, ? = -1 and V(?) = 0 (no potential). The traversability assumes that the wormhole possesses two asymptotically flat regions with corresponding Schwarzschild masses. We find that asymptotical masses of a wormhole with nonminimal derivative coupling could be positive and/or negative depending on ?. In particular, both masses are positive only provided ? < ?1 ? 0; otherwise, one or both wormhole masses are negative. In conclusion, we give qualitative arguments that a wormhole configuration with positive masses could be stable.

Sushkov, Sergey V.; Korolev, Roman

2012-04-01

264

Synthesis and pharmacological activity of diterpenylnaphthoquinone derivatives.  

PubMed

New diterpenylquinones, combining a diterpene diacid and a naphthoquinone, were prepared from junicedric acid and lapachol. The new derivatives were assessed as gastroprotective agents by the HCl-EtOH-induced gastric lesions model in mice as well as for basal cytotoxicity on the following human cell lines: Normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), and hepatocellular carcinoma (Hep G2). Several of the new compounds were significantly active as antiulcer agents and showed selective cytotoxicity against AGS cells. PMID:21996716

Pertino, Mariano Walter; Theoduloz, Cristina; Palenzuela, Jose Antonio; Afonso, Maria del Mar; Yesilada, Erdem; Monsalve, Francisco; González, Paulo; Droguett, Daniel; Schmeda-Hirschmann, Guillermo

2011-01-01

265

Chemically Derived, Ultrasmooth Graphene Nanoribbon Semiconductors  

Microsoft Academic Search

We developed a chemical route to produce graphene nanoribbons (GNR) with width below 10 nanometers, as well as single ribbons with varying widths along their lengths or containing lattice-defined graphene junctions for potential molecular electronics. The GNRs were solution-phase derived, stably suspended in solvents with noncovalent polymer functionalization, and exhibited ultrasmooth edges with possibly well-defined zigzag or armchair-edge structures. Electrical

Xiaolin Li; Xinran Wang; Li Zhang; Sangwon Lee; Hongjie Dai

2008-01-01

266

Canonical structure of higher derivative theories  

NASA Astrophysics Data System (ADS)

The canonical structure of theories whose Lagrangian contains higher powers of time derivatives is often obscured by the nonlinear relationship between the velocities and momenta. We use the Dirac formalism and define a generalized Legendre transform to overcome some of the difficulties associated with inverting the relation between velocities and momenta. We are then able to define a standard single valued symplectic structure on phase space and a compatible single valued Hamiltonian. We demonstrate the application of our formalism in several examples.

Avraham, Eran; Brustein, Ram

2014-07-01

267

Eosinophil Secretion of Granule-Derived Cytokines  

PubMed Central

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

Spencer, Lisa A.; Bonjour, Kennedy; Melo, Rossana C. N.; Weller, Peter F.

2014-01-01

268

Synthesis of Silicon Derivatives with Ruthenium Catalysts  

Microsoft Academic Search

Methods for synthesis of saturated and unsaturated organosilicon compounds as well as other silicon derivatives based on ruthenium-catalyzed reactions have been reviewed. All the catalytic processes discussed lead to formation of either novel carbon–silicon bonds or novel carbon–carbon bonds affected by a substituted silyl group at carbon. Saturated organosilicon products can be prepared via hydrosilylation of alkenes and activation of

Bogdan Marciniec; Cezary Pietraszuk

269

Synthesis and cytotoxicity study of alkannin derivatives  

Microsoft Academic Search

Alkannin derivatives (3–19) were prepared through the reaction of ?,?-dimethylacrylalkannin (1), the most abundant isohexenylnaphthazarin isolated from the roots of Arnebia euchroma, with different types of nucleophiles such as amines and thiols in the absence or presence of a reducing agent. The cytotoxicities of 1–8, 10–14 and 19 against four human carcinoma cell line (GLC-82, CNE2, Bel-7402, K-562) were found

Zhi-Shu Huang; Hai-Qiang Wu; Zhi-Fang Duan; Bing-Fen Xie; Zong-Chao Liu; Gong-Kan Feng; Lian-Quan Gu; Albert S. C. Chan; Yue-Ming Li

2004-01-01

270

Blue photoluminescence from chemically derived graphene oxide  

Microsoft Academic Search

Fluorescent organic compounds are of significant importance to the development of low-cost opto-electronic devices. Blue fluorescence from aromatic or olefinic molecules and their derivatives is particularly important for display and lighting applications. Thin film deposition of low-molecular-weight fluorescent organic compounds typically requires costly vacuum evaporation systems. On the other hand, solution-processable polymeric counterparts generally luminesce at longer wavelengths due to

Goki Eda; Yun-Yue Lin; Cecilia Mattevi; Hisato Yamaguchi; Hsin-An Chen; I-Sheng Chen; Chun-Wei Chen; Manish Chhowalla

2009-01-01

271

Acetylene-Terminated Aspartimides And Derived Resins  

NASA Technical Reports Server (NTRS)

New polymers and derived blends exhibit improved processability and properties. New toughened epoxies exhibit excellent properties, but use temperatures limited. Bismaleimide resins are some base materials formulated to develop materials having moderate use temperatures. Work conducted on use of acetylenic (ethynyl) group to cross-link and extend chains of oligomers and polymers to obtain materials to perform at higher temperatures. Extended to include acetylene-terminated aspartimides (ATA's).

Hergenrother, Paul M.; Connell, John W.; Havens, Stephen J.

1989-01-01

272

Triamine chelants, their derivatives, complexes and conjugates  

DOEpatents

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.

Troutner, David E. (Phoenixville, PA); John, Christy S. (Gaithersburg, MD); Pillai, Maroor R. A. (Vashi, IN)

1995-01-01

273

Triamine chelants, their derivatives, complexes and conjugates  

DOEpatents

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.

Troutner, D.E.; John, C.S.; Pillai, M.R.A.

1995-03-07

274

The Fréchet Derivatives of Electromagnetic Induction  

Microsoft Academic Search

netic induction are examined in detail. The response functions for both modes are shown to be Fr6chet differentiable in an L 2 norm for general conductivity structures and arbitrary source frequency-wavenumber morphology. Perturbation forms of the modal Green functions are derived and used to examine the Fr6chet kernels for a seafloor controlled source and a Kelvin wave model. In both

Alan D. Chave

1984-01-01

275

Joint moments of derivatives of characteristic polynomials  

E-print Network

We investigate the joint moments of the 2k-th power of the characteristic polynomial of random unitary matrices with the 2h-th power of the derivative of this same polynomial. We prove that for a fixed h, the moments are given by rational functions of k, up to a well-known factor that already arises when h=0. We fully describe the denominator in those rational functions (this had already been done by Hughes experimentally), and define the numerators through various formulas, mostly sums over partitions. We also use this to formulate conjectures on joint moments of the zeta function and its derivatives, or even the same questions for the Hardy function, if we use a ``real'' version of characteristic polynomials. Our methods should easily be applicable to other similar problems, for instance with higher derivatives of characteristic polynomials. NOTE: More data is available on the author's website or attached to the LaTeX source of this arXiv submission.

Paul-Olivier Dehaye

2007-03-15

276

Derivation of naïve human embryonic stem cells  

PubMed Central

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

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

277

Neutrophil-Derived Cytokines: Facts Beyond Expression  

PubMed Central

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

Tecchio, Cristina; Micheletti, Alessandra; Cassatella, Marco A.

2014-01-01

278

Derivation of naive human embryonic stem cells.  

PubMed

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

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

2014-03-25

279

Affinity of guanosine derivatives for polycytidylate revisited  

NASA Technical Reports Server (NTRS)

Evidence is presented for complexation of guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) with polycytidylate (poly(C)) at pH 8.0 and 23 degrees C in the presence of 1.0 M NaCl2 and 0.2 M MgCl2 in water. The association of 2-MeImpG with poly(C) was investigated using UV-vis spectroscopy as well as by monitoring the kinetics of the nucleophilic substitution reaction of the imidazole moiety by amines. The results of both methods are consistent with moderately strong poly(C) 2-MeImpG complexation and the spectrophotometric measurements allowed the construction of a binding isotherm with a concentration of 2-MeImpG equal to 5.55 +/- 0.15 mM at half occupancy. UV spectroscopy was employed to establish the binding of other guanosine derivatives on poly(C). These derivatives are guanosine 5'-monophosphate (5'GMP), guanosine 5'-monophosphate imidazolide (ImpG), and guanosine 5'-monophosphate morpholidate (morpG). Within experimental error these guanosine derivatives exhibit the same affinity for poly(C) as 2-MeImpG.

Kanavarioti, A.; Hurley, T. B.; Baird, E. E.

1995-01-01

280

Two-point derivative dispersion relations  

E-print Network

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-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 $(E/m)^\\lambda[\\ln (E/m)]^n$, that cover the cases of practical interest in particle physics phenomenology at high energies. We explicitly study the expressions for the cases with $\\lambda$ negative odd integers, that require identification of cancelation of singularities, and provide the corresponding final results.

Erasmo Ferreira; Javier Sesma

2014-03-24

281

Long-memory volatility in derivative hedging  

NASA Astrophysics Data System (ADS)

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.

Tan, Abby

2006-10-01

282

Hypersensitivity reactions to anthranilic acid derivatives.  

PubMed

Anthranilic acid derivatives are a group of nonsteroidal antiinflammatory drugs that include glafenine and fenamates. We report a woman who had immediate adverse reactions to glafenine and meclofenamate sodium. Skin prick and intradermal tests were performed with solutions of glafenine and meclofenamate in phosphate-buffered saline (PBS) and with the drugs bound to human serum albumin (HSA). Prick and intradermal tests with PBS solutions were negative for both drugs as were prick tests with HSA solutions. Intradermal tests with HSA-glafenine, however, were positive at 20 minutes, and at 6 and 24 hours. Intradermal tests with HSA-meclofenamate elicited a positive response at 6 and 24 hours. These tests were negative when performed in control subjects. A leukocyte histamine release test and a RAST assay were negative for both drugs. The patient was challenged following a double-blind placebo-controlled oral procedure and tolerated therapeutic doses of aspirin, indomethacin, ibuprofen, dipyrone, diclofenac, piroxicam, and acetaminophen. The oral challenge with glafenine and meclofenamate reproduced the reactions (eliciting doses: 50 mg and 15 mg, respectively), and the patient also reacted to 30 mg of mefenamic acid, an anthranilic acid derivative she had never previously received. This is an exceptional case of selective adverse reactions to glafenine and fenamates, anthranilic acid derivatives, in a patient tolerating aspirin and other cyclooxygenase inhibitors. Our study implicates an immunologic mechanism, and the existence of cross-reactivity between the drugs (or some active metabolite generated in vivo). PMID:7903514

Fernandez-Rivas, M; de la Hoz, B; Cuevas, M; Davila, I; Quirce, S; Losada, E

1993-12-01

283

Exosomes Derived from Mesenchymal Stem Cells  

PubMed Central

The functional mechanisms of mesenchymal stem cells (MSCs) have become a research focus in recent years. Accumulating evidence supports the notion that MSCs act in a paracrine manner. Therefore, the biological factors in conditioned medium, including exosomes and soluble factors, derived from MSC cultures are being explored extensively. The results from most investigations show that MSC-conditioned medium or its components mediate some biological functions of MSCs. Several studies have reported that MSC-derived exosomes have functions similar to those of MSCs, such as repairing tissue damage, suppressing inflammatory responses, and modulating the immune system. However, the mechanisms are still not fully understood and the results remain controversial. Compared with cells, exosomes are more stable and reservable, have no risk of aneuploidy, a lower possibility of immune rejection following in vivo allogeneic administration, and may provide an alternative therapy for various diseases. In this review, we summarize the properties and biological functions of MSC-derived exosomes and discuss the related mechanisms. PMID:24608926

Yu, Bo; Zhang, Xiaomin; Li, Xiaorong

2014-01-01

284

Fluid dynamic derivatives: Marine and wind engineering approaches  

Microsoft Academic Search

An alternative formulation, applied in marine and air craft fluid dynamics, of the traditional aerodynamic derivatives model, is presented. The relationship between the derivatives of the two models is derived, from which the exact interdependencies of the derivatives of the traditional model can be found. A forced motion model testing device, termed a planar motion mechanism (PMM), applicable for the

Andreas G. Jensen

1997-01-01

285

Transformation of spatial and perturbation derivatives of travel time  

E-print Network

Transformation of spatial and perturbation derivatives of travel time at a general interface and perturbation parameters. We derive the explicit equations for transforming these travel­time derivatives Hamiltonian function and are applicable to the transformation of travel­time derivatives in both isotropic

Cerveny, Vlastislav

286

Rough Derivatives in Rough Function Model and Their Application  

Microsoft Academic Search

On the theory and application of rough derivatives in rough function model, the notion of generalized rough functions is defined to improve the definition of higher order rough derivatives Pawlak proposed, and analyze the functional features of roughly derived functions and higher order roughly derived functions. The rough extremum definition of discrete functions is given, Fermat theorem and Rolle theorem

Yun Wang; Yanyong Guan; Hongkai Wang

2007-01-01

287

Stem cell-derived neurons functionally integrate in  

E-print Network

Stem cell-derived neurons functionally integrate in living mice Neurons derived from stem cells that, after transplantation into living animals, human stem cell-derived neurons can receive neuronal human embryonic stem cell (hESC)-derived neurons engineered to be specifically activated by light

Fortuna, Miguel A.

288

Hydrogen From Bio-Derived LiquidsHydrogen From BioHydrogen From Bio--Derived LiquidsDerived Liquids Dave King, Yong Wang, PNNL  

E-print Network

production Ethanol is rapidly becoming an infrastructure fuel and is a logical feedstock APR provides H2 product 63.173448 120010.91 140353.17 Fuel ethanol 418.8445 26817.293 29487.8 Steam Molar Flow CoHydrogen From Bio-Derived LiquidsHydrogen From BioHydrogen From Bio--Derived LiquidsDerived Liquids

289

Biologic Rhythms Derived from Siberian Mammoths' Hairs  

PubMed Central

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

Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

2011-01-01

290

Nonclassical biological activities of quinolone derivatives.  

PubMed

Quinolones are considered as a big family of multi-faceted drugs; their chemical synthesis is flexible and can be easily adapted to prepare new congeners with rationally devised structures. This is shown by the description of many thousands of derivatives in the literature. Scientists could accurately describe their QSAR, which is essential for effective drug design. This also gave them the chance to discover new and unprecedented activities, which makes quinolones an endless source of hope and enables further development of new clinically useful drugs. Quinolones are among the most common frameworks present in the bioactive molecules that have dominated the market for more than four decades. Since 1962, 4(1H)-quinolone-3-carboxylic acid derivatives are widely used as antibacterial agents. Quinolones have a broad and potent spectrum of activity and are also used as second-line drugs to treat tuberculosis (TB). Recently, quinolones have been reported to display "nonclassical" biological activities, such as antitumor, anti-HIV-1 integrase, anti-HCV-NS3 helicase and -NS5B-polymerase activities. The present review focuses on the structural modifications responsible for the transformation of an antibacterial into an anticancer agent and/or an antiviral agent. Indeed, quinolones' antimicrobial action is distinguishable among antibacterial agents, because they target different type II topoisomerase enzymes. Many derivatives of this family show high activity against bacterial topoisomerases and eukaryotic topoisomerases, and are also toxic to cultured mammalian cells and in vivo tumor models. Moreover, quinolones have shown antiviral activity against HIV and HCV viruses. In this context the quinolones family of drugs seem to link three different biological activities (antibacterial, anticancer, and the antiviral profiles) and the review will also provide an insight into the different mechanisms responsible for these activities among different species. PMID:22365088

Ahmed, Abeer; Daneshtalab, Mohsen

2012-01-01

291

Biologic Rhythms Derived from Siberian Mammoths Hairs  

SciTech Connect

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.

M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

2011-12-31

292

A geometrical derivation of the Dirac equation  

E-print Network

We give a geometrical derivation of the Dirac equation by considering a spin-1/2 particle travelling with the speed of light in a cubic spacetime lattice. The mass of the particle acts to flip the multi-component wavefunction at the lattice sites. Starting with a difference equation for the case of one spatial and one time dimensions, we generalize the approach to higher dimensions. Interactions with external electromagnetic and gravitational fields are also considered. One logical interpretation is that only at the lattice sites is the spin-1/2 particle aware of its mass and the presence of external fields.

Y. Jack Ng; H. van Dam

2003-02-04

293

Proca equations derived from first principles  

E-print Network

Gersten has shown how Maxwell equations can be derived from first principles, similar to those which have been used to obtain the Dirac relativistic electron equation. We show how Proca equations can be also deduced from first principles, similar to those which have been used to find Dirac and Maxwell equations. Contrary to Maxwell equations, it is necessary to introduce a potential in order to transform a second order differential equation, as the Klein-Gordon equation, into a first order differential equation, like Proca equations.

Michel Gondran

2009-01-21

294

Orientation of perylene derivatives on semiconductor surfaces  

Microsoft Academic Search

The orientation of the perylene derivatives 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and N,N?-dimethyl-3,4,9,10-perylenetetracarboxylic diimide (DiMe-PTCDI) on sulphur passivated GaAs(100) surfaces and its impact on the optical properties were studied by means of near-edge X-ray absorption fine structure spectroscopy (NEXAFS), Raman spectroscopy, and variable angle spectroscopic ellipsometry (VASE). NEXAFS shows that PTCDA molecules lie flat on the substrate with their molecular plane parallel

T. U. Kampen; G. Salvan; A. Paraian; C. Himcinschi; A. Yu. Kobitski; M. Friedrich; D. R. T. Zahn

2003-01-01

295

Paracyclophane derivatives in frustrated Lewis pair chemistry.  

PubMed

The metal-free activation of hydrogen was achieved using [2.2]paracyclophane-derived bisphosphines as Lewis base in frustrated Lewis pair chemistry. The rigid scaffold allows the orientation of functional groups so that steric aspects can be studied without altering the electronic nature. Depending on the geometry, structurally different phosphonium hydridoborates were generated when the frustrated Lewis pairs were exposed to hydrogen. The bisphosphines were applied in the 1,4-hydrosilylation-hydrogenation domino reaction providing access to secondary silyl-protected alcohols from enones in one step. Additionally, the planar-chiral scaffold was applied for the synthesis of novel enantiopure Lewis acids and Lewis bases. PMID:23111727

Greb, Lutz; Paradies, Jan

2013-01-01

296

NASP derived vehicles - Not just to space  

NASA Astrophysics Data System (ADS)

NASP-derived vehicles (NDVs) are presently noted to include not only exoatmospheric launch vehicles but also hypersonic cruisers. A conceptual development status evaluation is presented for such hypersonic aircraft, with a view to their likely military and civilian missions and the technical issues that remain to be solved for their implementation. Attention is given to plausible NDV configurations, propulsion systems, and performance goals for Mach 4.0 fighter-bomber, Mach 5.0 commercial/military transport, Mach 10.0 long-range cruiser, and SSTO launch vehicle.

Johnson, Donald B.; Espinosa, Angel M.; Althuis, Jeffrey S.

1992-12-01

297

Validation of an Experimentally Derived Uncertainty Model  

NASA Technical Reports Server (NTRS)

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.

Lim, K. B.; Cox, D. E.; Balas, G. J.; Juang, J.-N.

1996-01-01

298

Black Holes in Higher-Derivative Gravity  

E-print Network

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.

Lu, H; Pope, C N; Stelle, K S

2015-01-01

299

Synthesis and cytotoxicity study of alkannin derivatives.  

PubMed

Alkannin derivatives (3-19) were prepared through the reaction of beta,beta-dimethylacrylalkannin (1), the most abundant isohexenylnaphthazarin isolated from the roots of Arnebia euchroma, with different types of nucleophiles such as amines and thiols in the absence or presence of a reducing agent. The cytotoxicities of 1-8, 10-14 and 19 against four human carcinoma cell line (GLC-82, CNE2, Bel-7402, K-562) were found to be markedly higher than that of the naturally occurring beta,beta-dimethylacrylalkannin (1) and acetylalkannin (2). This study also shed light on the understanding of the biological activities in terms of the chemical reactivity of alkannins. PMID:15337288

Huang, Zhi-Shu; Wu, Hai-Qiang; Duan, Zhi-Fang; Xie, Bing-Fen; Liu, Zong-Chao; Feng, Gong-Kan; Gu, Lian-Quan; Chan, Albert S C; Li, Yue-Ming

2004-09-01

300

Geometric derivation of the chronometric redshift.  

PubMed Central

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

Segal, I E

1993-01-01

301

[Synthesis of potential CCK antagonist quinazolone derivatives].  

PubMed

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

Szabó, M; Kökösi, J; Orfi, L

1995-07-01

302

Derivation of an Applied Nonlinear Schroedinger Equation.  

SciTech Connect

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

Pitts, Todd Alan; Laine, Mark Richard; Schwarz, Jens; Rambo, Patrick K.; Karelitz, David B.

2015-01-01

303

24-norhopene derivatives from Diatenopteryx sorbifolia.  

PubMed

Two new hopene derivatives, 3 beta,6 beta-dihydroxy-21 alpha H-24-norhopa-4(23),22(29)-diene (1) and 3 beta,5 beta-dihydroxy-6 beta-[(4-hydroxybenzoyl)oxy]-21 alpha H-24-norhopa-4(23),22(29)-diene (2), together with cleomiscosin B (3) and 5,6-dimethoxy-7-hydroxycoumarin (umckalin), were isolated from the timber of Diatenopteryx sorbifolia. This is the first isolation of the norhopene skeleton from nature. The structures of the isolates were established by spectroscopic analysis. PMID:9322363

Chávez, J P; David, J M; Yang, S W; Cordell, G A

1997-09-01

304

Diphenylurea Derivatives Induce Somatic Embryogenesis in Citrus  

Microsoft Academic Search

The present research investigates the possibility that three diphenylurea (DPU) derivatives, N-phenyl-N?-benzothiazol-6-ylurea (PBU), N,N?-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU) and N,N?-bis-(3,4-methilendioxyphenyl)urea (3,4-MDPU), stimulate the induction of somatic embryogenesis in three Citrus species. The hypothetical embryogenic activity was assessed using stigma and styles of Citrus myrtifolia Raf., Citrus madurensis Lour. and Citrus limon (L.) Burm. The three compounds influenced the production of somatic embryos differently

Angela Carra; Fabio De Pasquale; Ada Ricci; Francesco Carimi

2006-01-01

305

Dietary derived compounds in cancer chemoprevention  

PubMed Central

Cancer chemoprevention is defined as the application of natural or synthetic agents to suppress or reverse cancer development and progression. In this field especially diet derived compounds have recently attracted researchers’ attention as potential therapeutics generally exerting low toxicity compared with regular drugs. This review presents a survey of recent findings concerning the most promising dietary chemopreventive agents such as green tea polyphenols (i.e. catechins), long-chain polyunsaturated fatty acids, carotenoids, glucosinolates/isothiocyanates, vitamins (i.e. vitamin D and folate) and minerals (i.e. calcium and selenium). Molecular targets involved in intrinsic pathways affected by these natural compounds are also shortly discussed. PMID:23788916

Rzeski, Wojciech

2012-01-01

306

Developing market for waste-derived fuel  

SciTech Connect

Markets are developing for products such as closely specified fuel, graded compost and clean ferrous metal and the company in question is aiming to produce these from waste treatment projects. The plant used for the waste derived fuel consists of equipment such as plant feeders, a vertical hammer mill, a ballistic classifier, magnetic separators, shredders, dryers a densifying unit and the final product are dense pellets with good handling properties. The compost, which is produced from the undersize waste material is mixed with water or sewage sludge and processed by the Siloda biological system. It then goes to a maturation pile for 60 days from where it can be distributed.

Wilson, D.

1984-08-17

307

Anionic derivatives of uracil: fragmentation and reactivity.  

PubMed

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

Cole, Callie A; Wang, Zhe-Chen; Snow, Theodore P; Bierbaum, Veronica M

2014-09-01

308

Derive capillary pressure from well logs  

SciTech Connect

A new approach has been developed to estimate in-situ capillary pressure and relative permeability characteristics in the transition zone. The technique is based on incorporating petrophysical data measured on core samples with well log analysis. Relative permeability can be determined for both drainage and inhibition conditions using the matched capillary pressure data. A technique has been developed to extrapolate petro-physical data where core data is absent or not representative of in-situ conditions. It is based on using log data to derive a water saturation vs. depth profile in the transition zone of the formation of interest. The log-derived water saturation distribution is then correlated to generalized capillary pressure curves typical of the formation studied. The capillary pressure type curves are generated from available core data and other petrophysical information. Relative permeability curves are then generated using correlations based on Purcell's model. The technique can be used in multi-layered and homogeneous reservoirs provided that one homogeneous layer is at least 20 ft thick.

Ibrahim, A. (Suez Canal Univ. (Egypt)); Desbrandes, R.; Bassiouni, Z. (Louisiana State Univ., Baton Rouge, LA (United States))

1994-07-01

309

Tulczyjew Triples in Higher Derivative Field Theory  

E-print Network

The geometrical structure known as Tulczyjew triple has been used with success in analytical mechanics and first order field theory to describe a wide range of physical systems including Lagrangian/Hamiltonian systems with constraints and/or sources, or with singular Lagrangian. Starting from the first principles of the variational calculus we derive Tulczyjew triples for classical field theories of arbitrary high order, i.e.~depending on arbitrary high derivatives of the fields. A first triple appears as the result of considering higher order theories as first order ones with configurations being constrained to be holonomic jets. A second triple is obtained after a reduction procedure aimed at getting rid of nonphysical degrees of freedom. This picture we present is fully covariant and complete: it contains both Lagrangian and Hamiltonian formalisms, in particular the Euler-Lagrange equations. Notice that, the required Geometry of jet bundles is affine (as opposed to the linear Geometry of the tangent bundle). Accordinlgy, the notions of affine duality and affine phase space play a distinguished role in our picture. In particular the Tulczyjew triples in this paper consist of morphisms of double affine-vector bundles which, moreover, preserve suitable presymplectic structures.

Katarzyna Grabowska; Luca Vitagliano

2014-06-25

310

Thermal electron heating rate: A derivation  

NASA Technical Reports Server (NTRS)

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.

Hoegy, W. R.

1983-01-01

311

Primer on electricity futures and other derivatives  

SciTech Connect

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.

Stoft, S.; Belden, T.; Goldman, C.; Pickle, S.

1998-01-01

312

Antistaphylococcal activity of novel salicylanilide derivatives.  

PubMed

This study examined the antibacterial properties of nineteen benzoxazole, isoniazid, ethionamide and salicylanilide derivatives against Staphylococcus aureus (S. aureus). It was found that three salicylanilide-derived compounds demonstrated antistaphylococcal activity: 5-Chloro-2-hydroxy-N-(4-(trifluoromethyl)phenyl)benzamide (5-Cl-4'-CF3- SAL), 4-chloro-2-(3-chlorophenylcarbamyoyl)phenyl)-2-(benzyloxycarbonylamino)propanoate (AIM31) and 4-chloro-2- (4-(trifluoromethyl)phenylcarbamoyl)phenyl acetate (AIM33). Investigation of the chemical structures of these three compounds and comparison with a non-inhibitory salicylanilide compound (i.e. 5,3'-diCl-SAL) illustrated that different combinations of chemical groups at defined positions on the salicylanilide core structure had a marked influence on antistaphylococcal activity. The most effective compound was AIM33 which inhibited staphylococcal growth and displayed an initial MIC value of 3.12 ?g ml(-1) and subsequent investigation revealed that an MIC as low as of 0.5 ?g ml(-1) was achievable. In this case, the dual presence of a trifluoromethyl group and an acetylated phenolic hydroxyl to the salicylanilide core structure led to greatly enhanced activity. PMID:21644919

Mollaghan, Annmarie; Vinsova, Jarmila; Imramovsky, Ales; Cotter, Lesley; Lucey, Brigid; O'Mahony, Jim; Costelloe, Aisling; Coffey, Aidan

2012-03-01

313

Kalman-predictive-proportional-integral-derivative (KPPID)  

SciTech Connect

With third generation synchrotron X-ray sources, it is possible to acquire detailed structural information about the system under study with time resolution orders of magnitude faster than was possible a few years ago. These advances have generated many new challenges for changing and controlling the state of the system on very short time scales, in a uniform and controlled manner. For our particular X-ray experiments on crystallization or order-disorder phase transitions in metallic alloys, we need to change the sample temperature by hundreds of degrees as fast as possible while avoiding over or under shooting. To achieve this, we designed and implemented a computer-controlled temperature tracking system which combines standard Proportional-Integral-Derivative (PID) feedback, thermal modeling and finite difference thermal calculations (feedforward), and Kalman filtering of the temperature readings in order to reduce the noise. The resulting Kalman-Predictive-Proportional-Integral-Derivative (KPPID) algorithm allows us to obtain accurate control, to minimize the response time and to avoid over/under shooting, even in systems with inherently noisy temperature readings and time delays. The KPPID temperature controller was successfully implemented at the Advanced Photon Source at Argonne National Laboratories and was used to perform coherent and time-resolved X-ray diffraction experiments.

Fluerasu, A.; Sutton, M. (McGill)

2004-12-17

314

Antimicrobial activity of basic cholane derivatives, VIII.  

PubMed

Two series of new compounds derived from deoxycholic acid have been synthesized: 3,12-dioxo-5 beta-cholan-24-N-substituted amides and their 3 beta-amino and 3 beta-N-alkylamino derivatives. The first series of five compounds 1-5 carries at C-24 the residue of benzylamine, morpholine, diethanolamine, N,N-diethyl-ethylenediamine, and N-methylpiperazine. The second series of twenty compounds 1A-D - 5A-D was prepared by means of reductive amination starting from the compounds of the first series. This reaction proved to be regioselective and stereospecific: it attacks only C-3 of the steroid moiety and introduces the following axial beta-oriented substituents: amino, methylamino, ethylamino, and benzylamino. The compounds of the first series showed moderate scattered antimicrobial activity; while introduction of the 3 beta-amino and 3 beta-N-alkylamino residue greatly increased activity towards Gram (+) strains; even yeast and fungi appear to be sensitive towards this last series of compounds. The results have been discussed with respect to the nature of the substituents both at C-3 and C-24, the highest activity being associated to the hydrophobicity of these residues. PMID:2619517

Bellini, A M; Quaglio, M P; Mencini, E; Guarneri, M; Cavazzini, G; Fini, A

1989-12-01

315

Isocoumarin derivatives and benzofurans from a sponge-derived Penicillium sp. fungus.  

PubMed

Ten new fungal metabolites, including three hydroisocoumarins, penicimarins A-C (1-3), three isocoumarins, penicimarins D-F (6-8), and four benzofurans, penicifurans A-D (11-14), together with four known isocoumarin derivatives (4, 5, 9, 10), were obtained from the sponge-derived fungus Penicillium sp. MWZ14-4, collected from the South China Sea. Their planar structures and relative configurations were elucidated by detailed analysis of spectroscopic data and by comparison with related known compounds. The absolute configurations of 1-4 were assigned by the modified Mosher's method and TDDFT ECD calculations together with comparison of their CD spectra. Compound 1 represents a rare naturally occurring isocoumarin derivative with 4-substitution, but no substituent at the 3-position. These compounds were evaluated for antibacterial activities and cytotoxic activities in vitro. Among them, penicifuran A (11) exhibited inhibitory activity against Staphylococcus albus with an MIC value of 3.13 ?M. PMID:23477451

Qi, Jun; Shao, Chang-Lun; Li, Zhi-Yong; Gan, Li-She; Fu, Xiu-Mei; Bian, Wen-Tao; Zhao, Hong-Ying; Wang, Chang-Yun

2013-04-26

316

Numerical approach to the Caputo derivative of the unknown function  

NASA Astrophysics Data System (ADS)

If a function can be explicitly expressed, then one can easily compute its Caputo derivative by the known methods. If a function cannot be explicitly expressed but it satisfies a differential equation, how to seek Caputo derivative of such a function has not yet been investigated. In this paper, we propose a numerical algorithm for computing the Caputo derivative of a function defined by a classical (integer-order) differential equation. By the properties of Caputo derivative derived in this paper, we can change the original typical differential system into an equivalent Caputo-type differential system. Numerical examples are given to support the derived numerical method.

Zeng, Fanhai; Li, Changpin

2013-10-01

317

Genetic instability in calamondin ( Citrus madurensis Lour.) plants derived from somatic embryogenesis induced by diphenylurea derivatives  

Microsoft Academic Search

Somatic embryos were regenerated in vitro from calamondin style–stigma explants cultured in the presence of N\\u000a 6-benzylaminopurine (BAP) cytokinin and three synthetic phenylurea derivatives, N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), N-phenyl-N?-benzothiazol-6-ylurea (PBU) and N,N?-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU). The phenylurea derivative compounds tested at micromolar level (12 ?M) were\\u000a able to induce a percentage of responsive explants significantly higher from that obtained with BAP and hormone-free (HF)\\u000a conditions.

Mirko Siragusa; Angela Carra; Lidia Salvia; Anna Maria Puglia; Fabio De Pasquale; Francesco Carimi

2007-01-01

318

Antimalarial Activities of Dermaseptin S4 Derivatives  

PubMed Central

The hemolytic antimicrobial peptide dermaseptin S4 was recently shown to exert antimalarial activity. In this study, we attempted to understand the underlying mechanism(s) and identify derivatives with improved antimalarial activity. A number of dermaseptin S4 derivatives inhibited parasite growth with a 50% inhibitory concentration (IC50) in the micromolar range. Among these, the substituted S4 analog K4K20-S4 was the most potent (IC50 = 0.2 ?M), while its shorter version, K4-S4(1–13)a, retained a considerable potency (IC50 = 6 ?M). Both K4K20-S4 and K4-S4(1–13)a inhibited growth of the parasites more at the trophozoite stage than at the ring stage. Significant growth inhibition was observed after as little as 1 min of exposure to peptides and proceeded with nearly linear kinetics. The peptides selectively lysed infected red blood cells (RBC) while having a weaker effect on noninfected RBC. Thus, K4K20-S4 lysed trophozoites at concentrations similar to those that inhibited their proliferation, but trophozoites were >30-fold more susceptible than normal RBC to the lytic effect of K4K20-S4, the most hemolytic dermaseptin. The same trend was observed with K4-S4(1–13)a. The d isomers of K4K20-S4 or K4-S4(1–13)a were as active as the l counterparts, indicating that antimalarial activity of these peptides, like their membrane-lytic activity, is not mediated by specific interactions with a chiral center. Moreover, dissipation of transmembrane potential experiments with infected cells indicated that the peptides induce damage in the parasite's plasma membrane. Fluorescence confocal microscopy analysis of treated infected cells also indicated that the peptide is able to find its way through the complex series of membranes and interact directly with the intracellular parasite. Overall, the data showed that dermaseptins exert antimalarial activity by lysis of infected cells. Dermaseptin derivatives are also able to disrupt the parasite plasma membrane without harming that of the host RBC. PMID:10952593

Krugliak, Miriam; Feder, Rina; Zolotarev, Vadim Y.; Gaidukov, Leonid; Dagan, Arie; Ginsburg, Hagai; Mor, Amram

2000-01-01

319

Equilibrium dialysis using chromophoric sugar derivatives.  

PubMed

Equilibrium dialysis has been used to examine the binding affinity of ligands to proteins. It is a simple and reliable method, which requires only inexpensive equipment. For analysis of lectin-sugar interactions, the lectin and sugar are placed in the individual chambers separated by the membrane to allow the sugar to diffuse into the lectin chamber. After equilibrium has been reached, the concentrations of the sugar in both chambers are determined to evaluate the sugar-binding affinity of lectin. In this chapter, an example of the equilibrium dialysis experiment using the chromophoric derivatives of galactose and N-acetylgalactosamine is demonstrated, which reveals the difference in the affinity as well as specificities of two different carbohydrate-binding sites present in the B-chains of the plant lectin ricin. PMID:25117234

Hatakeyama, Tomomitsu

2014-01-01

320

Modular synthesis of oxazolines and their derivatives.  

PubMed

A class of modular oxazolines and their derivatives 1-5 were synthesized with moderate to excellent yields using a simple one-pot method; 4 x 3 bis-oxazolines were obtained, as expected, from each of the three reactions of 1,4-dicyanobenzene, 1,3-dicyanobenzene, and 1,2-dicyanobenzene with optically active amino alcohols in chlorobenzene under dry, anaerobic conditions. ZnCl(2) was used as a Lewis acid catalyst. Direct condensation of 1, 2-bis(cyanomethyl) benzene or 2-cyanophenylacetonitrile did not yield the target products, but two series of novel compounds (4 and 5) were isolated and their structures were confirmed by X-Ray analysis. All products (1-5) were characterized by NMR, IR, and MS. PMID:19138088

Mei, Luo; Hai, Zhang Jia; Jie, Sun; Ming, Zhou Shi; Hao, Yin; Liang, Hu Ke

2009-03-01

321

Overview of medically important antifungal azole derivatives.  

PubMed Central

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

Fromtling, R A

1988-01-01

322

Calixradialenes: calixarene derivatives with exocyclic double bonds.  

PubMed

Reaction of dioxocalix[4]arene 7 with MeLi followed by 2-fold elimination of water yielded calixarene 8 possessing exocyclic double bonds at two adjacent bridges. Calixarene 8 exists in tetrachloroethane-d2 solution at rt, as a 2.3:1 mixture of the 1,3-alternate and partial cone conformers. Keto[n]calixarenes (n = 5, 6) were prepared via hydrolysis of the bromocalixarenes 11 and 12, followed by CrO3 oxidation of the respective hydroxymethylene derivatives. Addition of MeLi to the ketocalix[n]arenes (n = 4, 5 and 6) followed by elimination of water yielded the corresponding calix[n]radialenes. Calix[5]- and calix[6]radialenes adopt in the crystal irregular alternate (i.e., noncone) conformations. PMID:24364562

Poms, David; Itzhak, Norbert; Kuno, Lev; Biali, Silvio E

2014-01-17

323

Derivation of Quantum Theory from Feynman's Rules  

E-print Network

Feynman's formulation of quantum theory is remarkable in its combination of formal simplicity and computational power. However, as a formulation of the abstract structure of quantum theory, it is incomplete as it does not account for most of the fundamental mathematical structure of the standard von Neumann-Dirac formalism such as the unitary evolution of quantum states. In this paper, we show how to reconstruct the entirety of the finite-dimensional quantum formalism starting from Feynman's rules with the aid of a single new physical postulate, the no-disturbance postulate. This postulate states that a particular class of measurements have no effect on the outcome probabilities of subsequent measurements performed. We also show how it is possible to derive both the amplitude rule for composite systems of distinguishable subsystems and Dirac's amplitude-action rule, each from a single elementary and natural assumption, by making use of the fact that these assumptions must be consistent with Feynman's rules.

Philip Goyal

2014-03-14

324

Scrap tire derived fuel: Markets and issues  

SciTech Connect

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.

Serumgard, J. [Scrap Tire Management Council, Washington, DC (United States)

1997-12-01

325

Thiazolidone derivatives as inhibitors of chikungunya virus.  

PubMed

A series of arylalkylidene derivatives of 1,3-thiazolidin-4-one (1-20) were synthesized and tested for their antiviral activity against chikungunya virus (LR2006_OPY1) in Vero cell culture by CPE reduction assay. Five compounds (7-9, 16 and 19) were identified to have anti-ChikV activity at lower micro molar concentration. The compounds 7, 8, 9, 16 and 19 inhibited the virus at 0.42, 4.2, 3.6, 40.1 and 6.8 ?M concentrations respectively. Molecular docking simulation has been carried out using the available X-ray crystal structure of the ChikV nsp2 protease, in order to elucidate the possible mechanism of action. Interaction of ligands with ChikV nsp2 protease (PDB Code: 3TRK) suggested the possible mechanism of protease inhibition to act as potent anti-ChikV agents. PMID:25462237

Jadav, Surender Singh; Sinha, Barij Nayan; Hilgenfeld, Rolf; Pastorino, Boris; de Lamballerie, Xavier; Jayaprakash, Venkatesan

2015-01-01

326

Caffeic acid derivatives from Bupleurum chinense  

PubMed Central

In this study, caffeic acid (CA) and its three derivatives including 3-caffeoylquinic acid (3-CQA, neochlorogenic acid), 4-caffeoylquinic acid (4-CQA, cryptochlorogenic acid), and 5-caffeoylquinic acid (5-CQA, chlorogenic acid) were identified in Bupleurum chinense aerial parts using reverse-phase high-performance liquid chromatography (RP-HPLC) with photodiode array (PDA) detector, reference compounds and chemical reactions. Separation was performed on a C18 column using gradient elution with 4% (v/v) aqueous acetic acid and acetonitrile as mobile phase at ambient temperature. In addition, the flavonoid aglycones were characterized and quantified after acid hydrolysis of the plant material. The flavonols profile showed quercetin (0.36 g per 100 g), kaempferol (1.11 g per 100 g) and isorhamnetin (0.16 g per 100 g). Total phenolic and total flavonoid contents ranged from 7.3 to 18.7% and 0.58 to 2.72% in dry plant material, respectively.

Haghi, G.; Hatami, A.; Mehran, M.; Hosseini, H.

2014-01-01

327

Synthesis and conformational analysis of naphthylnaphthoxazine derivatives  

NASA Astrophysics Data System (ADS)

Four new primary aminonaphthols ( 4, 5, 9 and 10) were synthesized from 1- or 2-naphthol and 1- or 2-naphthaldehyde via naphthoxazines in modified Mannich condensations. Simple ring-closure reactions of these aminonaphthols with paraformaldehyde, 4-nitrobenzaldehyde, phosgene or 4-chlorophenyl isothiocyanate led to new heterocyclic derivatives. In these transformations, either an sp 2 or an sp 3 carbon was inserted between the hydroxy and amino groups. The effects of substituents and the naphthyl ring on the conformation were investigated by means of NMR measurements, employing both dipolar and scalar couplings. The structures were confirmed by DFT quantum chemical calculations involving computed coupling constants, intramolecular distances between nuclei and the relative energies of the preferred conformers.

Tóth, Diána; Szatmári, István; Heydenreich, Matthias; Koch, Andreas; Kleinpeter, Erich; Fülöp, Ferenc

2009-07-01

328

Towards Tartaric-Acid-Derived Asymmetric Organocatalysts  

PubMed Central

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

Gratzer, Katharina; Gururaja, Guddeangadi N; Waser, Mario

2013-01-01

329

Cationically polymerizable monomers derived from renewable sources  

SciTech Connect

The objective of this project is to make use of products obtained from renewable plant sources as monomers for the direct production of polymers which can be used for a wide range of plastic applications. In this report is described progress in the synthesis and polymerization of cationically polymerizable monomers and oligomers derived from botanical oils, terpenes, natural rubber, and lignin. Nine different botanical oils were obtained from various sources, characterized and then epoxidized. Their photopolymerization was carried out using cationic photoinitiators and the mechanical properties of the resulting polymers characterized. Preliminary biodegradation studies are being conducted on the photopolymerized films from several of these oils. Limonene was cationically polymerized to give dimers and the dimers epoxidized to yield highly reactive monomers suitable for coatings, inks and adhesives. The direct phase transfer epoxidation of squalene and natural rubber was carried out. The modified rubbers undergo facile photocrosslinking in the presence of onium salts to give crosslinked elastomers. 12 refs., 3 figs., 10 tabs.

Crivello, J.V.

1991-10-01

330

Chaotic inflation in higher derivative gravity theories  

E-print Network

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.

Myrzakul, Shynaray; Sebastiani, Lorenzo

2015-01-01

331

Chaotic inflation in higher derivative gravity theories  

E-print Network

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.

Shynaray Myrzakul; Ratbay Myrzakulov; Lorenzo Sebastiani

2015-01-08

332

Fluorescein Derivatives in Intravital Fluorescence Imaging  

PubMed Central

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

Robertson, Thomas A.; Bunel, Florestan; Roberts, Michael S.

2013-01-01

333

Radiation Protection Using Carbon Nanotube Derivatives  

NASA Technical Reports Server (NTRS)

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.

Conyers, Jodie L., Jr.; Moore, Valerie C.; Casscells, S. Ward

2010-01-01

334

Derived relational responding as generalized operant behavior.  

PubMed Central

The major aim of the present study was to demonstrate that derived relational responding may be viewed as a form of generalized operant behavior. In Experiment 1, 4 subjects were divided into two conditions (2 in each condition). Using a two-comparison matching-to-sample procedure, all subjects were trained and tested for the formation of two combinatorially entailed relations. Subjects were trained and tested across multiple stimulus sets. Each set was composed of novel stimuli. Both Conditions 1 and 2 involved explicit performance-contingent feedback presented at the end of each block of test trials (i.e., delayed feedback). In Condition 1, feedback was accurate (consistent with the experimenter-designated relations) following exposure to the initial stimulus sets. When subjects' responding reached a predefined mastery criterion, the feedback then switched to inaccurate (not consistent with the experimenter-designated relations) until responding once again reached a predefined criterion. Condition 2 was similar to Condition 1, except that exposure to the initial stimulus sets was followed by inaccurate feedback and once the criterion was reached feedback switched to accurate. Once relational responding emerged and stabilized, response patterns on novel stimulus sets were controlled by the feedback delivered for previous stimulus sets. Experiment 2 replicated Experiment 1, except that during Conditions 3 and 4 four comparison stimuli were employed during training and testing. Experiment 3 was similar to Condition 1 of Experiment 1, except that after the mastery criterion was reached for class-consistent responding, feedback alternated from accurate to inaccurate across each successive stimulus set. Experiment 4 involved two types of feedback, one type following tests for mutual entailment and the other type following tests for combinatorial entailment. Results from this experiment demonstrated that mutual and combinatorial entailment may be controlled independently by accurate and inaccurate feedback. Overall, the data support the suggestion, made by relational frame theory, that derived relational responding is a form of generalized operant behavior. PMID:11029023

Healy, O; Barnes-Holmes, D; Smeets, P M

2000-01-01

335

Fluoride removal performance of glass derived hydroxyapatite  

SciTech Connect

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).

Liang, Wen, E-mail: wliang@ecust.edu.cn [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China)] [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China); Zhan, Lei; Piao, Longhua [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China)] [Research Institute of Biomaterials, School of Materials Science and Engineering, East China University of Science and Technology (China); Russel, Christian [Otto-Schott-Institut, Universitaet Jena, Jena (Germany)] [Otto-Schott-Institut, Universitaet Jena, Jena (Germany)

2011-02-15

336

76 FR 51922 - Modifications of Certain Derivative Contracts; Correction  

Federal Register 2010, 2011, 2012, 2013

...REG-109006-11] RIN 1545-BK13 Modifications of Certain Derivative Contracts; Correction AGENCY: Internal Revenue Service...nonassigning counterparty when there is an assignment of certain derivative contracts. It was published in the Federal Register on...

2011-08-19

337

76 FR 16587 - Risk Management Requirements for Derivatives Clearing Organizations  

Federal Register 2010, 2011, 2012, 2013

...Part 39 RIN 3038-AC98 Risk Management Requirements for Derivatives Clearing Organizations AGENCY: Commodity Futures Trading...the comment period for a proposed rule that would require derivatives clearing organizations (DCOs) to report...

2011-03-24

338

76 FR 66011 - Modifications of Certain Derivative Contracts; Hearing Cancellation  

Federal Register 2010, 2011, 2012, 2013

...REG-109006-11] RIN 1545-BK13 Modifications of Certain Derivative Contracts; Hearing Cancellation AGENCY: Internal Revenue...nonassigning counterparty when there is an assignment of certain derivative contracts. DATES: The public hearing, originally...

2011-10-25

339

40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).  

Code of Federal Regulations, 2012 CFR

...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...

2012-07-01

340

40 CFR 721.10328 - Salt of polyalkylenepolyamine derivative (generic).  

Code of Federal Regulations, 2013 CFR

...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...

2013-07-01

341

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

342

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.  

...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...

2014-04-01

343

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.  

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

344

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.  

Code of Federal Regulations, 2011 CFR

...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...

2011-04-01

345

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.  

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

346

Characterization of Transport Proteins for Aromatic Compounds Derived from Lignin: Benzoate Derivative Binding Proteins  

PubMed Central

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 sequencebased 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

Michalska, Karolina; Chang, Changsoo; Mack, Jamey C.; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R.

2013-01-01

347

Alternative derivation of the response of interferometric gravitational wave detectors  

SciTech Connect

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.

Cornish, Neil J. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States)

2009-10-15

348

Thermodynamic Derivation of the Equilibrium Distribution Functions of Statistical Mechanics.  

ERIC Educational Resources Information Center

Presents a simplified derivation of the equilibrium distribution functions. The derivation proceeds from the change in the Helmholtz free energy when a particle is added to a system of fixed temperature, volume, and chemical potential. The derivations show the relationship between statistical mechanics and macroscopic thermodynamics. (Author/GA)

Stoeckly, Beth

1979-01-01

349

Derivation of the Freundlich Adsorption Isotherm from Kinetics  

ERIC Educational Resources Information Center

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…

Skopp, Joseph

2009-01-01

350

17 CFR 240.16b-6 - Derivative securities.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Derivative securities. 240.16b-6 Section...Section 16(b) § 240.16b-6 Derivative securities. (a) The establishment...is fixed. (b) The closing of a derivative security position as a result...

2010-04-01

351

8 CFR 207.7 - Derivatives of refugees.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Derivatives of refugees. 207.7 Section 207... ADMISSION OF REFUGEES § 207.7 Derivatives of refugees. (a) Eligibility...the principal alien. An accompanying derivative is a spouse or child of a...

2010-01-01

352

Characterizing Thematized Derivative Schema by the Underlying Emergent Structures  

ERIC Educational Resources Information Center

This paper reports on different underlying structures of the derivative schema of three undergraduate students that were considered to be at the trans level of development of the derivative schema (action-process-object-schema). The derivative schema is characterized in terms of the students' ability to explicitly transfer the relationship between…

Garcia, Mercedes; Llinares, Salvador; Sanchez-Matamoros, Gloria

2011-01-01

353

21 CFR 184.1317 - Garlic and its derivatives.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Garlic and its derivatives. 184.1317 Section 184.1317...GRAS § 184.1317 Garlic and its derivatives. (a) Garlic is the fresh or dehydrated... a genus of the lily family. Its derivatives include essential oils,...

2010-04-01

354

Generalized Second-Order Partial Derivatives of 1/r  

ERIC Educational Resources Information Center

The generalized second-order partial derivatives of 1/r, where r is the radial distance in three dimensions (3D), are obtained using a result of the potential theory of classical analysis. Some non-spherical-regularization alternatives to the standard spherical-regularization expression for the derivatives are derived. The utility of a…

Hnizdo, V.

2011-01-01

355

21 CFR 184.1282 - Dill and its derivatives.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Dill and its derivatives. 184.1282 Section 184.1282...as GRAS § 184.1282 Dill and its derivatives. (a) Dill (American or European...seeds from Anethum sowa, D.C. Its derivatives include essential oils,...

2010-04-01

356

21 CFR 184.1257 - Clove and its derivatives.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Clove and its derivatives. 184.1257 Section 184.1257...GRAS § 184.1257 Clove and its derivatives. (a) Cloves are the dried unopened...Thunberg, native to tropical Asia. Their derivatives include essential oils...

2010-04-01

357

40 CFR 721.6097 - Phosphoric acid derivative (generic name).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Phosphoric acid derivative (generic name). 721.6097 Section...Substances § 721.6097 Phosphoric acid derivative (generic name). (a) Chemical...identified generically as a phosphoric acid derivative (PMN P-95-284) is subject...

2010-07-01

358

AUTOMATIC CONTINUITY OF DERIVATIONS ON -ALGEBRAS AND JB  

E-print Network

AUTOMATIC CONTINUITY OF DERIVATIONS ON C -ALGEBRAS AND JB -TRIPLES ANTONIO M. PERALTA AND BERNARD conditions under which every derivation from a JB-triple E into a Banach (Jordan) triple E-module is continuous. In particular, every derivation from a real or complex JB-triple into its dual space is automati

Russo, Bernard

359

Exact Multisoliton Solutions of General Nonlinear Schrödinger Equation with Derivative  

PubMed Central

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

Li, Qi; Duan, Qiu-yuan; Zhang, Jian-bing

2014-01-01

360

Pricing Derivatives on Financial Securities Subject to Credit Risk  

Microsoft Academic Search

This article provides a new methodology for pricing and hedging derivative securities involving credit risk. Two types of credit risks are considered. The first is where the asset underlying the derivative security may default. The second is where the writer of the derivative security may default. The authors apply the foreign currency analogy of R. Jarrow and S. Turnbull (1991)

Robert A. Jarrow; Stuart M. Turnbull

1995-01-01

361

Derivation of microscopic unified Bohr–Mottelson rotational model  

Microsoft Academic Search

In a previous article, we derived a microscopic version of the phenomenological Bohr–Mottelson unified rotational model for rotation about a single axis. In this article, we generalize the derivation to that for rotation about all the three axes. As in the previous derivation, we apply the nuclear Hamiltonian directly to the rotational-model wavefunction instead of using the usual canonical transformation.

P. Gulshani

2011-01-01

362

Recurrence relations for the Cartesian derivatives of the Zernike polynomials.  

PubMed

A recurrence relation for the first-order Cartesian derivatives of the Zernike polynomials is derived. This relation is used with the Clenshaw method to determine an efficient method for calculating the derivatives of any linear series of Zernike polynomials. PMID:24695132

Stephenson, Philip C L

2014-04-01

363

Original article Stability of milk-derived calcium  

E-print Network

Original article Stability of milk-derived calcium phosphate suspensions Skelte G. ANEMA* Fonterra January 2009 Abstract ­ Milk-derived calcium phosphate (MDCP) can be isolated from whey derived from acid casein or cottage cheese manufacture as a precipitated calcium phosphate material. However

Paris-Sud XI, Université de

364

An Empirical Study of Derivatives use in the REIT Industry  

Microsoft Academic Search

We examine the use of derivatives in the real estate investment trust (REIT) industry. Tax considerations and speculative motives should not be important factors here, as REITs pay no corporate income tax and their speculative activities are limited by regulations. We find that 41 % of REITs use interest-rate derivatives, although the amount of derivatives on average is not high.

Yuh-Sheng Horng; Peihwang Wei

1999-01-01

365

Derivatives Do Affect Mutual Funds Returns : How and When?  

Microsoft Academic Search

This paper is the first to present evidence on the magnitude of derivative use by mutual funds. Using a unique data set of detailed balance sheet information on open-end mutual funds, we characterize the nature of derivative use by these funds. Most mutual funds using derivatives do so to a very limited extent that has little discernable impact on returns.

Charles Cao; Eric Ghysels; Frank Hatheway

2001-01-01

366

Kinetic Theory Derivation of the Adiabatic Law for Ideal Gases.  

ERIC Educational Resources Information Center

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)

Sobel, Michael I.

1980-01-01

367

Automation of Nested Matrix and Derivative Operations Robert Kalaba  

E-print Network

Automation of Nested Matrix and Derivative Operations Robert Kalaba Departments of Electrical the automatic differentiation of hmctions expressed in terms of the derivatives d other fimctions. Building is introduced for the systematic exact evaluation of higher-order partial derivatives. Building on a key idea

Tesfatsion, Leigh

368

Biomass-Derived Energy Products and Co-Products Market  

E-print Network

Biomass-Derived Energy Products and Co-Products Market This report identifies the bio-fuels and co & Earth Science & Technology ­ University of Hawai`i at Manoa #12;Biomass-Derived Energy Products and Co agency thereof. #12;Biomass Derived Energy Products and Co- Products Market and Off-take Study Hawaii

369

Theaflavin derivatives in black tea and catechin derivatives in green tea inhibit HIV1 entry by targeting gp41  

Microsoft Academic Search

Theaflavin derivatives and catechin derivatives are the major polyphenols in black tea and green tea, respectively. Several tea polyphenols, especially those with galloyl moiety, can inhibit HIV-1 replication with multiple mechanisms of action. Here we showed that the theaflavin derivatives had more potent anti-HIV-1 activity than catechin derivatives. These tea polyphenols could inhibit HIV-1 entry into target cells by blocking

Shuwen Liu; Hong Lu; Qian Zhao; Yuxian He; Jinkui Niu; Asim K. Debnath; Shuguang Wu; Shibo Jiang

2005-01-01

370

Polyketides from a Marine-Derived Fungus Xylariaceae sp.  

PubMed Central

Eighteen polyketides (1–18) including six citrinin derivatives, two phenol derivatives, one cyclopentenone, two naphthol derivatives, and seven tetralone derivatives were isolated from the culture broth of a marine-derived fungal strain Xylariaceae sp. SCSGAF0086. Five of these compounds (1, 2, 8, 9, and 10) were new, and their structures were determined by spectroscopic methods. Compounds 4, 6, 7, and 17 showed enzyme-inhibitory activities towards several tested enzymes, and 6 and 7 showed strong antifouling activity against Bugula neritina larvae settlement. This is the first time that the antifouling and enzyme-inhibitory activities of these compounds has been reported. PMID:23697953

Nong, Xu-Hua; Zheng, Zhi-Hui; Zhang, Xiao-Yong; Lu, Xin-Hua; Qi, Shu-Hua

2013-01-01

371

Urease inhibitory activities of ?-boswellic acid derivatives  

PubMed Central

Background and the purpose of the study Boswellia carterii have been used in traditional medicine for many years for management different gastrointestinal disorders. In this study, we wish to report urease inhibitory activity of four isolated compound of boswellic acid derivative. Methods 4 pentacyclic triterpenoid acids were isolated from Boswellia carterii and identified by NMR and Mass spectroscopic analysis (compounds 1, 3-O-acetyl-9,11-dehydro-?-boswellic acid; 2, 3-O-acetyl-11-hydroxy-?-boswellic acid; 3. 3-O- acetyl-11-keto-?-boswellic acid and 4, 11-keto-?-boswellic acid. Their inhibitory activity on Jack bean urease were evaluated. Docking and pharmacophore analysis using AutoDock 4.2 and Ligandscout 3.03 programs were also performed to explain possible mechanism of interaction between isolated compounds and urease enzyme. Results It was found that compound 1 has the strongest inhibitory activity against Jack bean urease (IC50?=?6.27?±?0.03 ?M), compared with thiourea as a standard inhibitor (IC50?=?21.1?±?0.3 ?M). Conclusion The inhibition potency is probably due to the formation of appropriate hydrogen bonds and hydrophobic interactions between the investigated compounds and urease enzyme active site and confirms its traditional usage. PMID:23351363

2013-01-01

372

Gnotobiotic pigs-derivation and rearing.  

PubMed

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

Miniats, O P; Jol, D

1978-10-01

373

Zinc oxide nanostructures: morphology derivation and evolution.  

PubMed

Zinc oxide nanostructures of various types, including nanobelts, nanoplatelets, nanowires, and nanorods, have been synthesized via well-developed routes by many research groups. However, so far, the underlying mechanism for the morphology derivation and evolution of the nanostructures has not been elucidated in depth. In this article, we report the systematic investigation of the morphology evolution characteristics of ZnO nanostructures from dense rods to dense nanoplatelets, nanoplatelet flowers, dense nanobelt flowers, and nanowire flowers in an evaporation-physical transport-condensation approach. Through the use of crystal growth theory, the determining factors for the formation of different nanostructural morphologies were found to be gas-phase supersaturation and the surface energy of the growing surface planes. Other experimental parameters such as the temperature at the source and the substrate, the temperature difference and the distance between the source and the substrate, the heating rate of the furnace, the gas flow rate, the ceramic tube diameter, and the starting material are all correlated with supersaturation and impose an effect on the morphology evolution. This finding may have an important impact on the qualitative understanding of the morphology evolution of nanostructures and the achieving of desired nanostructures controllably. PMID:16853555

Ye, Changhui; Fang, Xiaosheng; Hao, Yufeng; Teng, Xuemei; Zhang, Lide

2005-10-27

374

Antioxidant activities of licorice-derived prenylflavonoids  

PubMed Central

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

Kim, Hyo Jung; Seo, Ji-Yeon; Suh, Hwa-Jin; Lim, Soon Sung

2012-01-01

375

Synthesis and bioactivity of novel coumarin derivatives.  

PubMed

A series of coumarin derivatives (6-8) containing (E)-methyl 2-(methoxyimino)-2-phenylacetate, (E)-2-(methoxyimino)-N-methyl-2-phenylacetamide and methyl methoxy(phenyl)carbamate were synthesized from substituted resorcinols (1) and substituted beta-keto esters (2) as starting material via cyclization and condensation reactions. The test results indicated that (E)-methyl 2-{2-[(3-hexyl-4-methyl-coumarin-7-yloxy)methyl]phenyl}-2-(methoxyimino)acetate (6f) was the optimal structure with good fungicidal activity against cucumber grey mold (CGM) giving 100% control at 100 mg L(-1) concentration, much higher than that of coumoxystrobin. Methyl 2-[(3,4-dimethyl-coumarin -7-yloxy)methyl]phenyl(methoxy)carbamate (8a) was another optimal structure with good fungicidal activity against wheat powdery mildew (WPM) showing 100% control at 50 mg L(-1) concentration, at the same level as that of the commercial kresoxim-methyl, and very significantly higher than that of coumoxystrobin (no control against WPM at 400 mg L(-1)). PMID:22312739

Guan, Ai-Ying; Liu, Chang-Ling; Li, Miao; Li, Zhi-Nian; Zhang, Ming-Xing; Zhang, Hong

2011-12-01

376

Jet flames of a refuse derived fuel  

SciTech Connect

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)

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

377

Occupationally derived chemicals in breast milk  

SciTech Connect

Exogenously derived chemicals have been widely reported in breast milk. Chemicals typically found in occupational exposures, including trace metals, solvents, and halogenated hydrocarbons, are reviewed, in terms of milk partition factors, potential infant exposures, and possible infant health effects. In addition to ingestion of a chemical from breast milk, an infant incurs a neonatal body burden of a chemical due to transplacental migration from maternal blood. For trace metals, neonatal blood levels are similar to maternal blood levels. Partition of metals to milk is less efficient, but nevertheless can contribute significantly to an infant's body burden. For lipid-soluble pesticide residues and halogenated biphenyls, neonatal body burden is much less than that of the mother, but transfer to milk is efficient, due to the high proportion of milk fat. It is suggested that potential organic mercury toxicity can be estimated from concentration in maternal blood or milk. For other chemicals, available data are not sufficient to evaluate short- or long-term health effects. However, for many halogenated hydrocarbons, concentrations in normal human milk would permit infant exposure above guidelines for allowable daily intake set by the World Health organization.

Wolff, M.S.

1983-01-01

378

Polyimides Derived from Novel Asymmetric Dianhydrides  

NASA Technical Reports Server (NTRS)

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.

Chuang, Chun-Hua (Inventor)

2012-01-01

379

Malignant melanoma derived from cerebriform intradermal naevus.  

PubMed

We report a case of malignant melanoma (MM) derived from cerebriform intradermal naevus (CIN) in a 66-year-old Japanese man. The patient had cutis verticis gyrata (CVG) on the posterior area of the scalp at birth. He noticed a dome-shaped nodule at the centre of the CVG at 66 years of age. Histopathological examination found a nodule of MM arising within an extensive area of intradermal naevus. There was no metastasis to lymph nodes or other organs. To our knowledge, only two cases of CIN in which MM had later developed have been reported. We estimated that the incidence of melanoma from CIN including our case is 4.5% (3 of 67 reported cases), which seems to be comparable to the frequency of malignant alteration of giant pigmented naevi. This suggests that pathological examination is recommended for CVG, and once pathological diagnosis of CIN is confirmed, long clinical follow-ups are necessary for detecting development of MM. PMID:19793094

Hayashi, Y; Tanioka, M; Taki, R; Sawabe, K; Kore-eda, S; Utani, A; Miyachi, Y

2009-12-01

380

Curdlan ester derivatives: synthesis, structure, and properties.  

PubMed

A series of ester derivatives of curdlan, which is a ?-(1 ? 3)-D-glucan extracellularly produced by microorganism, with varying alkyl chain lengths (C2-C12) were synthesized by the heterogeneous reaction using trifluoroacetic anhydride. As a result, high-molecular-weight (Mw ? 6 × 10(5)) and fully-acylated curdlan was obtained with relatively high yield (>70%). Thermal stability of curdlan was greatly improved by esterification. Crystallization was observed for curdlan esters with C2-C6 side chains. Both Tg (170 ? 50 °C) and Tm (290 ? 170 °C) of curdlan esters decreased with increasing the side-chain length. By the increase in the side-chain carbon number, curdlan esters showed lower Young's modulus and tensile strength, and larger elongation at break. Thus, material properties of curdlan esters can be controlled by changing the side-chain length. It was found that the increase of the side-chain length resulted in the decrease of crystallinity and the change of crystal structures. PMID:24528750

Marubayashi, Hironori; Yukinaka, Kazuyori; Enomoto-Rogers, Yukiko; Takemura, Akio; Iwata, Tadahisa

2014-03-15

381

Myeloid-Derived Suppressor Cells in Sepsis  

PubMed Central

Sepsis is a systemic, deleterious host response to widespread infection. Patients with sepsis will have documented or suspected infection which can progress to a state of septic shock or acute organ dysfunction. Since sepsis is responsible for nearly 3 million cases per year in China and severe sepsis is a common, expensive fatal condition in America, developing new therapies becomes a significant and worthwhile challenge. Clinical research has shown that sepsis-associated immunosuppression plays a central role in patient mortality, and targeted immune-enhancing therapy may be an effective treatment approach in these patients. As part of the inflammatory response during sepsis, there are elevations in the number of myeloid-derived suppressor cells (MDSCs). MDSCs are a heterogeneous population of immature myeloid cells that possess immunosuppressive activities via suppressing T-cell proliferation and activation. The role of MDSCs in sepsis remains uncertain. Some believe activated MDSCs are beneficial to the sepsis host by increasing innate immune responses and antimicrobial activities, while others think expansion of MDSCs leads to adaptive immune suppression and secondary infection. Herein, we discuss the complex role of MDSCs in immune regulation during sepsis, as well as the potential to target these cells for therapeutic benefit. PMID:24995313

Qin, Chaojin; Shu, Qiang

2014-01-01

382

Prediction of thermodynamic properties of coal derivatives  

SciTech Connect

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.

Donohue, M.D.

1990-09-01

383

Deriving Chesapeake Bay Water Quality Standards  

USGS Publications Warehouse

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.

Tango, Peter J.; Batiuk, Richard A.

2013-01-01

384

Derived Representation Schemes and Noncommutative Geometry.  

E-print Network

Some 15 years ago M. Kontsevich and A. Rosenberg [KR] proposed a heuristic principle according to which the family of schemes ${Rep_n(A)}$ parametrizing the finite-dimensional represen- tations of a noncommutative algebra A should be thought of as a substitute or "approximation" for Spec(A). The idea is that every property or noncommutative geometric structure on A should induce a corresponding geometric property or structure on $Rep_n(A)$ for all n. In recent years, many interesting structures in noncommutative geometry have originated from this idea. In practice, however, if an associative algebra A possesses a property of geometric nature (e.g., A is a NC complete intersection, Cohen-Macaulay, Calabi-Yau, etc.), it often happens that, for some n, the scheme $Rep_n(A)$ fails to have the corresponding property in the usual algebro-geometric sense. The reason for this seems to be that the representation functor $Rep_n$ is not "exact" and should be replaced by its derived functor $DRep_n$ (in the sense of non-abelian homological algebra). The higher homology of $DRep_n(A)$, which we call representation homology, obstructs $Rep_n(A)$ from having the desired property and thus measures the failure of the Kontsevich-Rosenberg "approximation." In this paper, which is mostly a survey, we prove several results confirming this intuition. We also give a number of examples and explicit computations illustrating the theory developed in [BKR] and [BR].

Yuri Berest; Giovanni Felder; Ajay Ramadoss

385

Myeloid derived suppressor cells in human diseases.  

PubMed

Myeloid derived suppressor cells (MDSC) have been described as a heterogeneous cell population with potent immune suppressor function in mice. Limited data are available on MDSC in human diseases. Interpretation of these data is complicated by the fact that different markers have been used to analyze human MDSC subtypes in various clinical settings. Human MDSC are CD11b+, CD33+, HLA-DR(neg/low) and can be divided into granulocytic CD14? and monocytic CD14+ subtypes. Interleukin 4R?, VEGFR, CD15 and CD66b have been suggested to be more specific markers for human MDSC, however these markers can only be found on some MDSC subsets. Until today the best marker for human MDSC remains their suppressor function, which can be either direct or indirect through the induction of regulatory T cells. Immune suppressor activity has been associated with high arginase 1 and iNOS activity as well as ROS production by MDSC. Not only in murine models, but even more importantly in patients with cancer, different drugs have been shown to either reverse the immune suppressor function of MDSC or directly target these cells. Systemic treatment with all-trans-retinoic acid has been shown to mature human MDSC and reverse their immune suppressor function. Alternatively, MDSC can be targeted by treatment with the multi-targeted receptor tyrosine kinase inhibitor sunitinib. This review will provide a comprehensive summary of the recent literature on human MDSC. PMID:21237299

Greten, Tim F; Manns, Michael P; Korangy, Firouzeh

2011-07-01

386

capture by carbide-derived carbons  

NASA Astrophysics Data System (ADS)

A series of carbide-derived carbons (CDCs) with different surface oxygen contents were prepared from TiC powder by chlorination and followed by HNO3 oxidation. The CDCs were characterized systematically by a variety of means such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultimate analysis, energy dispersive spectroscopy, N2 adsorption, and transmission electron microscopy. CO2 adsorption measurements showed that the oxidation process led to an increase in CO2 adsorption capacity of the porous carbons. Structural characterizations indicated that the adsorbability of the CDCs is not directly associated with its microporosity and specific surface area. As evidenced by elemental analysis, X-ray photoelectron spectroscopy, and energy dispersive spectroscopy, the adsorbability of the CDCs has a linear correlation with their surface oxygen content. The adsorption mechanism was studied using quantum chemical calculation. It is found that the introduction of O atoms into the carbon surface facilitates the hydrogen bonding interactions between the carbon surface and CO2 molecules. This new finding demonstrated that not only the basic N-containing groups but also the acidic O-containing groups can enhance the CO2 adsorbability of porous carbon, thus providing a new approach to design porous materials with superior CO2 adsorption capacity.

Xing, Wei; Liu, Chao; Zhou, Ziyan; Zhou, Jin; Wang, Guiqiang; Zhuo, Shuping; Xue, Qingzhong; Song, Linhua; Yan, Zifeng

2014-04-01

387

Metalloprotease Dependent Release of Placenta Derived Fractalkine  

PubMed Central

The chemokine fractalkine is considered as unique since it exists both as membrane-bound adhesion molecule and as shed soluble chemoattractant. Here the hypothesis was tested whether placental fractalkine can be shed and released into the maternal circulation. Immunohistochemical staining of human first trimester and term placenta sections localized fractalkine at the apical microvillous plasma membrane of the syncytiotrophoblast. Gene expression analysis revealed abundant upregulation in placental fractalkine at term, compared to first trimester. Fractalkine expression and release were detected in the trophoblast cell line BeWo, in primary term trophoblasts and placental explants. Incubation of BeWo cells and placental explants with metalloprotease inhibitor Batimastat inhibited the release of soluble fractalkine and at the same time increased the membrane-bound form. These results demonstrate that human placenta is a source for fractalkine, which is expressed in the syncytiotrophoblast and can be released into the maternal circulation by constitutive metalloprotease dependent shedding. Increased expression and release of placental fractalkine may contribute to low grade systemic inflammatory responses in third trimester of normal pregnancy. Aberrant placental metalloprotease activity may not only affect the release of placenta derived fractalkine but may at the same time affect the abundance of the membrane-bound form of the chemokine. PMID:24771984

Siwetz, Monika; Blaschitz, Astrid; Kremshofer, Julia; Bilic, Jelena; Desoye, Gernot; Huppertz, Berthold; Gauster, Martin

2014-01-01

388

Viable transgenic goats derived from skin cells.  

PubMed

The current study was undertaken to evaluate the possibility of expanding transgenic goat herds by means of somatic cell nuclear transfer (NT) using transgenic goat cells as nucleus donors. Skin cells from adult, transgenic goats were first synchronized at quiescent stage (G0) by serum starvation and then induced to exit G0 and proceed into G1. Oocytes collected from superovulated donors were enucleated, karyoplast-cytoplast couplets were constructed, and then fused and activated simultaneously by a single electrical pulse. Fused couplets were either co-cultured with oviductal cells in TCM-199 medium (in vitro culture) or transferred to intermediate recipient goat oviducts (in vivo culture) until final transfer. The resulting morulae and blastocysts were transferred to the final recipients. Pregnancies were confirmed by ultrasonography 25-30 days after embryo transfer. In vitro cultured NT embryos developed to morulae and blastocyst stages but did not produce any pregnancies while 30% (6/20) of the in vivo derived morulae and blastocysts produced pregnancies. Two of these pregnancies were resorbed early in gestation. Of the four recipients that maintained pregnancies to term, two delivered dead fetuses 2-3 days after their due dates, and two recipients gave birth to healthy kids at term. Fluorescence in situ hybridization (FISH) analysis confirmed that both kids were transgenic and had integration sites consistent with those observed in the adult cell line. PMID:15359599

Behboodi, Esmail; Memili, Erdogan; Melican, David T; Destrempes, Margaret M; Overton, Susan A; Williams, Jennifer L; Flanagan, Peter A; Butler, Robin E; Liem, Hetty; Chen, Li How; Meade, Harry M; Gavin, William G; Echelard, Yann

2004-06-01

389

Lophine derivatives as activators in peroxyoxalate chemiluminescence.  

PubMed

Lophine and four of its derivatives were used as activators (ACTs) of the chemiluminescent peroxyoxalate (PO) reaction of bis(2,4,6-trichlorophenyl)oxalate with H2O2, catalysed by imidazole. Kinetic emission assays have shown that with the tested compounds the reaction mechanism, regarding the formation of the high energy intermediate (HEI) of the PO reaction, occurs as previously seen for commonly used ACTs. A bimolecular interaction of the compounds with the HEI leads to chemiexcitation through the chemically initiated electron exchange luminescence (CIEEL) mechanism, as confirmed by a linear free-energy correlation between the relative catalytic rate constants and the oxidation potentials of the compounds. The yields of excited state formation and light emission, in the range of 10(-2)-10(-3) E mol(-1), are comparable to the ones seen with commonly used ACTs. A Hammett plot with ? = -0.90 indicates the buildup of a partial positive charge on the transition step of the catalytic process, consistent with the formation of a radical cation of the ACT, being an additional validation of the CIEEL mechanism in this system. PMID:25373732

Alves, J; Boaro, A; da Silva, J S; Ferreira, T L; Keslarek, V B; Cabral, C A; Orfão, R B; Ciscato, L F M L; Bartoloni, F H

2015-02-01

390

Derivation of dose conversion factors for tritium  

SciTech Connect

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.

Killough, G. G.

1982-03-01

391

Latent Heating Structures Derived from TRMM  

NASA Technical Reports Server (NTRS)

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

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

392

Effects of sulfate chitosan derivatives on nonalcoholic fatty liver disease  

NASA Astrophysics Data System (ADS)

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.

Yu, Mingming; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

2014-06-01

393

Indole derivatives from a marine sponge-derived yeast as DPPH radical scavengers.  

PubMed

Two new indole derivatives (3, 4) and three known compounds (1, 2, 5) were isolated as radical scavengers from the culture filtrate of a marine sponge-derived yeast. Their structures were determined to be tyrosol (1), tryptophol (2), 2-(1H-indol-3-yl)ethyl 2-hydroxypropanoate (3), 2-(1H-indol-3-yl)ethyl 5-hydroxypentanoate (4), and cyclo(L-Pro-L-Tyr) (5) on the basis of their spectroscopic data. The absolute configurations of compounds 3 and 5 were determined by chiral HPLC analysis combined with synthesis and Marfey's method, respectively. Each obtained compound was evaluated for DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, and all compounds exhibited weak activities. PMID:19943625

Sugiyama, Yasumasa; Ito, Yuki; Suzuki, Motofumi; Hirota, Akira

2009-11-01

394

Bioactive anthraquinone derivatives from the mangrove-derived fungus Stemphylium sp. 33231.  

PubMed

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

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

395

Enhancement of ventricular-subventricular zone-derived neurogenesis and oligodendrogenesis by erythropoietin and its derivatives.  

PubMed

In the postnatal mammalian brain, stem cells in the ventricular-subventricular zone (V-SVZ) continuously generate neuronal and glial cells throughout life. Genetic labeling of cells of specific lineages have demonstrated that the V-SVZ is an important source of the neuroblasts and/or oligodendrocyte progenitor cells (OPCs) that migrate toward injured brain areas in response to several types of insult, including ischemia and demyelinating diseases. However, this spontaneous regeneration is insufficient for complete structural and functional restoration of the injured brain, so interventions to enhance these processes are sought for clinical applications. Erythropoietin (EPO), a clinically applied erythropoietic factor, is reported to have cytoprotective effects in various kinds of insult in the central nervous system. Moreover, recent studies suggest that EPO promotes the V-SVZ-derived neurogenesis and oligodendrogenesis. EPO increases the proliferation of progenitors in the V-SVZ and/or the migration and differentiation of their progenies in and around injured areas, depending on the dosage, timing, and duration of treatment, as well as the type of animal model used. On the other hand, EPO has undesirable side effects, including thrombotic complications. We recently demonstrated that a 2-week treatment with the EPO derivative asialo-EPO promotes the differentiation of V-SVZ-derived OPCs into myelin-forming mature oligodendrocytes in the injured white matter of neonatal mice without causing erythropoiesis. Here we present an overview of the multifaceted effects of EPO and its derivatives in the V-SVZ and discuss the possible applications of these molecules in regenerative medicine. PMID:24348331

Kaneko, Naoko; Kako, Eisuke; Sawamoto, Kazunobu

2013-01-01

396

Specific Receptors for Platelet-Derived Growth Factor on Cells Derived from Connective Tissue and Glia  

Microsoft Academic Search

A cellular receptor for platelet-derived growth factor (PDGF) was demonstrated by incubation of 125I-labeled PDGF with human foreskin fibroblast cultures followed by liberation of cell-bound radioactivity with Triton X-100. The cellular binding of labeled PDGF in the presence of increasing amounts of unlabeled PDGF showed saturation; Scatchard analysis of binding data indicated a single class of receptors having kd=1× 10-9

Carl-Henrik Heldin; Bengt Westermark; Ake Wasteson

1981-01-01

397

Enhancement of ventricular-subventricular zone-derived neurogenesis and oligodendrogenesis by erythropoietin and its derivatives  

PubMed Central

In the postnatal mammalian brain, stem cells in the ventricular-subventricular zone (V-SVZ) continuously generate neuronal and glial cells throughout life. Genetic labeling of cells of specific lineages have demonstrated that the V-SVZ is an important source of the neuroblasts and/or oligodendrocyte progenitor cells (OPCs) that migrate toward injured brain areas in response to several types of insult, including ischemia and demyelinating diseases. However, this spontaneous regeneration is insufficient for complete structural and functional restoration of the injured brain, so interventions to enhance these processes are sought for clinical applications. Erythropoietin (EPO), a clinically applied erythropoietic factor, is reported to have cytoprotective effects in various kinds of insult in the central nervous system. Moreover, recent studies suggest that EPO promotes the V-SVZ-derived neurogenesis and oligodendrogenesis. EPO increases the proliferation of progenitors in the V-SVZ and/or the migration and differentiation of their progenies in and around injured areas, depending on the dosage, timing, and duration of treatment, as well as the type of animal model used. On the other hand, EPO has undesirable side effects, including thrombotic complications. We recently demonstrated that a 2-week treatment with the EPO derivative asialo-EPO promotes the differentiation of V-SVZ-derived OPCs into myelin-forming mature oligodendrocytes in the injured white matter of neonatal mice without causing erythropoiesis. Here we present an overview of the multifaceted effects of EPO and its derivatives in the V-SVZ and discuss the possible applications of these molecules in regenerative medicine. PMID:24348331

Kaneko, Naoko; Kako, Eisuke; Sawamoto, Kazunobu

2013-01-01

398

Territrem and Butyrolactone Derivatives from a Marine-Derived Fungus Aspergillus Terreus  

PubMed Central

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

Nong, Xu-Hua; Wang, Yi-Fei; Zhang, Xiao-Yong; Zhou, Mu-Ping; Xu, Xin-Ya; Qi, Shu-Hua

2014-01-01

399

Territrem and butyrolactone derivatives from a marine-derived fungus Aspergillus terreus.  

PubMed

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

Nong, Xu-Hua; Wang, Yi-Fei; Zhang, Xiao-Yong; Zhou, Mu-Ping; Xu, Xin-Ya; Qi, Shu-Hua

2014-01-01

400

Genetic instability in calamondin (Citrus madurensis Lour.) plants derived from somatic embryogenesis induced by diphenylurea derivatives.  

PubMed

Somatic embryos were regenerated in vitro from calamondin style-stigma explants cultured in the presence of N (6)-benzylaminopurine (BAP) cytokinin and three synthetic phenylurea derivatives, N-(2-chloro-4-pyridyl)-N-phenylurea (4-CPPU), N-phenyl-N'-benzothiazol-6-ylurea (PBU) and N,N'-bis-(2,3-methilendioxyphenyl)urea (2,3-MDPU). The phenylurea derivative compounds tested at micromolar level (12 muM) were able to induce a percentage of responsive explants significantly higher from that obtained with BAP and hormone-free (HF) conditions. In order to verify the genetic stability of the regenerants, 27 plants coming from different embryogenic events were randomly selected from each different culture condition and evaluated for somaclonal variations using inter-simple sequence repeat and random amplified polymorphic DNA analyses. We observed that 2,3-MDPU and PBU gave 3.7% of somaclonal mutants, whereas 4-CPPU gave 7.4% of mutants. No somaclonal variability was observed when plantlets were regenerated in BAP or HF medium. Although diphenylurea derivatives show a higher embryogenic potential as compared to BAP, they induce higher levels of somaclonal variability. This finding should be taken in consideration when new protocols for clonal propagation are being developed. PMID:17333016

Siragusa, Mirko; Carra, Angela; Salvia, Lidia; Puglia, Anna Maria; De Pasquale, Fabio; Carimi, Francesco

2007-08-01

401

Environmental applications of chitosan and its derivatives.  

PubMed

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).

Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi

2015-01-01

402

SAMZ: Satellite-Derived Management Zones  

NASA Technical Reports Server (NTRS)

The term "satellite-derived management zones" (SAMZ) denotes agricultural management zones that are subdivisions of large fields and that are derived from images of the fields acquired by instruments aboard Earth orbiting satellites during approximately the past 15 years. "SAMZ" also denotes the methodology and the software that implements the methodology for creating such zones. The SAMZ approach is one of several products of continuing efforts to realize a concept of precision agriculture, which involves optimal variations in seeding, in application of chemicals, and in irrigation, plus decisions to farm or not to farm certain portions of fields, all in an effort to maximize profitability in view of spatial and temporal variations in the growth and health of crops and in the chemical and physical conditions of soils. As used here, "management zone" signifies, more precisely, a subdivision of a field within which the crop production behavior is regarded as homogeneous. From the perspective of precision agriculture, management zones are the smallest subdivisions between which the seeding, application of chemicals, and other management parameters are to be varied. In the SAMZ approach, the main sources of data are the archives of satellite imagery that have been collected over the years for diverse purposes. One of the main advantages afforded by the SAMZ approach is that the data in these archives can be reused for purposes of precision agriculture at low cost. De facto, these archives contain information on all sources of variability within a field, including weather, crop types, crop management, soil types, and water drainage patterns. The SAMZ methodology involves the establishment of a Web-based interface based on an algorithm that generates management zones automatically and quickly from archival satellite image data in response to requests from farmers. A farmer can make a request by either uploading data describing a field boundary to the Web site or else drawing the boundary on a reference image. Hence, a farmer can start to engage in precision farming shortly after gaining access to the Web site, without need for incurring the high costs of conventional precision-agriculture data-collection practices that include collecting soil samples, mapping electrical conductivity of soil, and compiling multi-year crop-yield data. Given the boundary of a field, a SAMZ server computes the zones within the field in a three-stage process. In the first stage, a vector-valued image of the field is constructed by assembling, from the archives, the equivalent of a stack of the available images of the field (see figure). In the second stage, the vector-valued image is analyzed by use of a wavelet transform that detects spatial variations considered significant for precision farming while suppressing small-scale heterogeneities that are regarded as insignificant. In the third stage, a segmentation algorithm assembles the zones from smaller regions that have been identified in the wavelet analysis.

2004-01-01

403

Synthesis and electronic aspects of tetrahydrobenzothienopyrimidine derivatives  

NASA Astrophysics Data System (ADS)

The chemistry of thiophenes, pyrimidines, triazolopyrimidines and benzothiophenes has drawn much attention because of their biological activities. Their interesting properties are connected with their complex ?-electron delocalisation effects. Herein the synthesis, crystal and molecular structures at 100 K and DFT calculated structures of three tetrahydrobenzothienopyrimidine derivatives are reported i.e. 4-hydrazino-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine which was a substrate for 2-phenyl-8,9,10,11-tetrahydro[1]benzothieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine and 3-methyl-9,10,11,12-tetrahydro-2H-[1]benzothieno[2?,3?:4,5]pyrimido[1,6-b][1,2,4]triazin-2-one. Moreover the influence of the substituents, polycyclic structure and crystal packing and on the aromaticity of the fused heterocyclic rings have been also discussed. The 4-hydrazino-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine is a promising substrate for a number of different reactions and discovering novel biologically active heterocycles. All three molecules are planar except of the tetrahydrobenzene part, which shows normal conformation. In crystals the molecules are connected to each other by C-H⋯N, N-H⋯N, C-H⋯S and S⋯? contacts. The geometry of common core in all structures is similar and typical for this class of compounds. The aromaticity of the fused heteroaromatic systems has been investigated by means of the HOMA indices. The discrepancy between values of HOMA for isolated monocyclic compounds and studied molecules from crystal structure shows destabilization of aromaticity when the rings are fused in a larger heterocyclic systems. The thiophene part of the molecule is far more sensitive on the influence of both mesomeric effects in polycyclic system and molecular environment in solid-state than pyrimidine ring. The presence of intermolecular interactions was confirmed by Hirshfeld area analysis.

Gajda, Katarzyna; Astakhina, Valeriia; Ejsmont, Krzysztof; Kolomeitsev, Dmytro; Kovalenko, Sergiy; Zarychta, Bartosz

2015-03-01

404

Deriving Motor Primitives Through Action Segmentation  

PubMed Central

The purpose of the present experiment is to further understand the effect of levels of processing (top-down vs. bottom-up) on the perception of movement kinematics and primitives for grasping actions in order to gain insight into possible primitives used by the mirror system. In the present study, we investigated the potential of identifying such primitives using an action segmentation task. Specifically, we investigated whether or not segmentation was driven primarily by the kinematics of the action, as opposed to high-level top-down information about the action and the object used in the action. Participants in the experiment were shown 12 point-light movies of object-centered hand/arm actions that were either presented in their canonical orientation together with the object in question (top-down condition) or upside down (inverted) without information about the object (bottom-up condition). The results show that (1) despite impaired high-level action recognition for the inverted actions participants were able to reliably segment the actions according to lower-level kinematic variables, (2) segmentation behavior in both groups was significantly related to the kinematic variables of change in direction, velocity, and acceleration of the wrist (thumb and finger tips) for most of the included actions. This indicates that top-down activation of an action representation leads to similar segmentation behavior for hand/arm actions compared to bottom-up, or local, visual processing when performing a fairly unconstrained segmentation task. Motor primitives as parts of more complex actions may therefore be reliably derived through visual segmentation based on movement kinematics. PMID:21833296

Hemeren, Paul E.; Thill, Serge

2011-01-01

405

Routine development of objectively derived search strategies  

PubMed Central

Background Over the past few years, information retrieval has become more and more professionalized, and information specialists are considered full members of a research team conducting systematic reviews. Research groups preparing systematic reviews and clinical practice guidelines have been the driving force in the development of search strategies, but open questions remain regarding the transparency of the development process and the available resources. An empirically guided approach to the development of a search strategy provides a way to increase transparency and efficiency. Methods Our aim in this paper is to describe the empirically guided development process for search strategies as applied by the German Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, or "IQWiG"). This strategy consists of the following steps: generation of a test set, as well as the development, validation and standardized documentation of the search strategy. Results We illustrate our approach by means of an example, that is, a search for literature on brachytherapy in patients with prostate cancer. For this purpose, a test set was generated, including a total of 38 references from 3 systematic reviews. The development set for the generation of the strategy included 25 references. After application of textual analytic procedures, a strategy was developed that included all references in the development set. To test the search strategy on an independent set of references, the remaining 13 references in the test set (the validation set) were used. The validation set was also completely identified. Discussion Our conclusion is that an objectively derived approach similar to that used in search filter development is a feasible way to develop and validate reliable search strategies. Besides creating high-quality strategies, the widespread application of this approach will result in a substantial increase in the transparency of the development process of search strategies. PMID:22587829

2012-01-01

406

Local detailed balance: a microscopic derivation  

NASA Astrophysics Data System (ADS)

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.

Bauer, M.; Cornu, F.

2015-01-01

407

Slab Derived Fluids from the Kamchatka Arc  

NASA Astrophysics Data System (ADS)

Studying trace element and volatile gas characteristics of mantle xenoliths provides an inside look at the mechanisms behind geochemical transport between the slab and the mantle wedge. A total of seventeen mantle xenoliths from three Late-Pleistocene volcanoes, Avanchinsky, Shiveluch, and Kharchinsky south of the Aleutian-Kamchatka Arc have been collected and analyzed in this study. The mantle xenoliths range in composition from dunites to harzburgites. Micro-structural analysis has concluded that fluid inclusions are present in these samples along grain boundaries, as well as in kink banding in the olivine, ortho- and clinopyroxenes. Plastic deformation is evident in these grains and is linked to the shear stress associated with tectonism that caused slab to descend. The fluid inclusions are tentatively linked to the slab's descent rather than trapped during crystal formation. Trace element (Nd, Sr, Pb, REE,) and volatile gas (He, Ar, CO2) concentrations have been measured from the xenoliths and from gases trapped in the fluid inclusions. Initial results have shown that the fluids display the following volatile characteristics: [CO2/3He (2x109 - 3x1010)], [^13C (-16 - -36)] and [(3He/4He (0.6 - 7.3 times the air ratio)], as well as the following trace element characteristics: [87Sr/86Sr (0.703 - 0.7041)]. Also, elevated CO2/3He, low 3He/4He, and light ^13C all correlate with fluids found in the descending slab. The source of CO2 is dominated by organic or ophi- carbonate, not sedimentary carbonate. These results indicate an alteration of the mantle wedge by slab-derived fluids from altered oceanic crust.

Yurchyk, S.; Poreda, R.; Basu, A.; Darrah, T.

2006-12-01

408

Derivation of physically motivated wind speed scales  

NASA Astrophysics Data System (ADS)

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.

Dotzek, Nikolai

409

Tachometers Derived From a Brushless DC Motor  

NASA Technical Reports Server (NTRS)

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.

Howard, David E.; Smith, Dennis A.

2007-01-01

410

Derivative encoding for parallel magnetic resonance imaging a  

PubMed Central

Purpose: To introduce a linear shift-invariant relationship between the partial derivatives of k space signals acquired using multichannel receive coils and to demonstrate that k space derivatives can be used for image unwrapping.Methods: Fourier transform of k space derivatives contains information on the spatial origins of aliased pixels; therefore, images can be reconstructed by k space derivatives. Fully sampled phantom and brain images acquired at 3 T using a standard eight channel receive coil were used to validate the k space derivatives theorem by unwrapping aliased images.Results: Derivative encoding leads to new methods for parallel imaging reconstruction in both k space and image domains. Noise amplification in sensitivity encoding image reconstruction, which is considered to produce the optimal SNR, can be further reduced using k space derivative encoding without making any assumptions on the characteristics of the images to be reconstructed.Conclusions: This work demonstrated that the partial derivative of the k space signal acquired from one coil with respect to one direction can be expressed as a sum of partial derivatives of signals from multiple coils with respect to the perpendicular k space direction(s). This relationship between the partial derivatives of k space signals is linear and shift-invariant in the Cartesian coordinate system. PMID:21992376

Shen, Jun

2011-01-01

411

Rigorous derivation of electromagnetic self-force  

SciTech Connect

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.

Gralla, Samuel E.; Harte, Abraham I.; Wald, Robert M. [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States)

2009-07-15

412

Asteroid Thermal Properties Derived from Meteorite Data  

NASA Astrophysics Data System (ADS)

The thermal inertia of an asteroid’s surface determines its response to the various Yarkovsky effects, while its internal thermal diffusivity controls its thermal evolution. Each quantity is a function of the material’s thermal conductivity, heat capacity, and density. Over the past ten years we have conducted a detailed survey measuring density in meteorites and are currently in the early stages of similar surveys for thermal conductivity and heat capacity. While various meteorite types differ in small but significant ways, for asteroid studies typical average values of these quantities can be estimated to within about 10%. (Metallic asteroids would have significantly different behavior.) The most important variable controlling density and thermal conductivity is porosity, P, while heat capacity is a strong function of temperature, T. Most stony meteorite densities are within 10% of 3500*(1-P) (SI units); basaltic and volatile rich meteorites are 10% to 30% less dense. Thermal conductivity in the temperature range of interest in the asteroid belt is nearly constant with temperature but varies strongly with porosity; assuming the trend seen for meteorite porosities up to 25% can be extrapolated to higher porosities, with zero conductivity at 100% porosity, a typical conductivity (for porosities greater than 2%) can be approximated by k = 0.11/P - 0.11 (SI units). Heat capacity ranges from under 250 J/kgK at 100 K to over 600 J/kgK at 250 K; over these temperatures this variation can be fitted by a quadratic in T. From these formulae we can derive representative values for thermal inertia and diffusivity and see how they vary as a function of porosity and temperature values appropriate for most asteroids. The greatest variation is with porosity. Thermal diffusivity drops by nearly two orders of magnitude from 0 to 20% porosity, more slowly at higher porosities. Thermal inertia (at 200K) varies from 3000 (SI units) near zero porosity down to 3 as porosity approaches 100%; 10% porosity has a thermal inertia near 1000 while 90% porous is about 60. Literature asteroid thermal inertias range from as high as 1000 to below 30; asteroid thermal inertias below 100 demand an extremely porous (>80%) surface.

Consolmagno, Guy; Macke, R. J.; Britt, D. T.

2013-10-01

413

Preparations of anthraquinone and naphthoquinone derivatives and their cytotoxic effects.  

PubMed

Chrysophanol and 1,8-di-O-hexylchrysophanol derivatives having nucleic acid bases at position 5 were synthesized. Furthermore, derivatives of menadione substituted at position 11 (type A naphthoquinone derivatives) or methylmenadione substituted at position 7 (type B naphthoquinone derivatives) modified with nucleic acid bases, amines and thiocyano, selenocyano or thioacetyl groups were synthesized. The cytotoxic effects of these derivatives on HCT 116 cells, which poorly express P-glycoprotein (P-gp), and Hep G2 cells, which stably express P-gp, were evaluated by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results were compared with those obtained using 5-fluorouracil (5-FU), which has been used clinically. Several of these derivatives exhibited markedly higher potent cytotoxic effects not only on HCT cancer cells but also Hep G2 cancer cells as compared with 5-FU. PMID:21372410

Cui, Xing-Ri; Saito, Ryota; Kubo, Takatsugu; Kon, Daijiro; Hirano, Yuich; Saito, Setsuo

2011-01-01

414

Thermodynamic properties of materials derived from coal liquefaction  

SciTech Connect

Few measurements of the thermodynamic properties of materials obtained from the liquefaction of coal have been reported. Because several sets of well-defined fractions of coal-derived materials existed that had been separated and characterized by the Characterization Branch of the Division of Processing and Thermodynamics of this Center, the expertise of the Thermodynamics Research Branch was utilized to measure enthalpies of combustion and heat capacities of these materials. The sets of fractions came from five sources: a synthetic crude oil derived from western Kentucky coal by the char-oil-energy development (COED) process, a synthetic crude oil derived from Utah A-seam coal by the COED process, material derived from West Virginia Pittsburgh seam coal by the Synthoil process, material derived from Illinois No. 6 coal by the H-Coal process and materials derived from subbituminous coal by the Conoco Colstrip zinc chloride hydrocracking process.

Smith, N.K.; Lee-Bechtold, S.H.; Good, W.D.

1980-01-01

415

Massive Gravity from Higher Derivative Gravity with Boundary Conditions  

E-print Network

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.

Minjoon Park; Lorenzo Sorbo

2012-10-29

416

Structure and antiinflammatory activity relationships of wogonin derivatives  

Microsoft Academic Search

A number of wogonin derivatives have been synthesized as congeners of wogonin and evaluated for their inhibitory activities\\u000a of PGE2 production. Wogonin derivatives modified at the B ring of wogonin were obtained from 2,4-Dihydroxy-3,6-dimethoxyacetophenone\\u000a (1)via several steps. Most wogonin derivatives exhibited much reduced inhibitory activities against COX-2 catalyzed PGE2 production compared to that of wogonin. Alkylation of 5,7-phenol groups and

Jinhee Jang; Hyun Pyo Kim

2005-01-01

417

A Continuous Derivative for Real-Valued Functions  

Microsoft Academic Search

We develop a notion of derivative of a real-valued function on a Banach space, called the L-derivative, which is constructed by int roducing a gener- alization of Lipschitz constant of a map. As with the Clarke gradient, the values of the L-derivative of a function are non-empty weak* compact and convex subsets of the dual of the Banach space. The

Abbas Edalat

2007-01-01

418

A Continuous Derivative for Real-Valued Functions  

Microsoft Academic Search

Summary. We develop a notion of derivative of a real-valued function on a Banach space, called the L-derivative, which is constructed by introducing a generalization of Lipschitz constant of a map. As with the Clarke gradient, the values of the L-derivative of a function are nonempty, weak,* compact, and convex subsets of the dual of the Banach space. The Lderivative,

Abbas Edalat

419

Automatic Derivation of Formal Software Specifications From Informal Descriptions  

Microsoft Academic Search

SPECIFIER, an interactive system which derives formal specifications of data types and programs from their informal descriptions, is described. The process of deriving formal specifications is viewed as a problem-solving process. The system uses common problem-solving techniques such as schemas, analogy, and difference-based reasoning to derive formal specifications. If an informal description is a commonly occurring operation for which the

Kanth Miriyala; Mehdi T. Harandi

1991-01-01

420

Synthesis of novel steroid derivatives derived from dehydroepiandrosterone as potential anticancer agents.  

PubMed

A series of dehydroepiandrosterone derivatives containing dihydrazone unit was synthesized via a convenient condensation procedure, and which were evaluated for their potential anticancer activities. The preliminary assays indicated that some of the newly synthesized compounds exhibited good antitumor activities against human hepatocellular liver carcinoma (HepG2), heptoma (Huh-7), gastric cancer (BGC-823) and breast adenocarcinoma (MCF-7) cell lines compared with 5-fluorouracil (5-FU), which might be considered as promising lead scaffold for further design and synthesis of potential anticancer agents. PMID:23547874

Ke, Shaoyong; Wei, Yanhong; Shi, Liqiao; Yang, Qingyu; Yang, Ziwen

2013-10-01

421

Napyradiomycin Derivatives, Produced by a Marine-Derived Actinomycete, Illustrate Cytotoxicity by Induction of Apoptosis  

PubMed Central

The microbial production, isolation and structure elucidation of four new napyradiomycin congeners (1–4) is reported. The structures of these compounds, which are new additions to the marine-derived meroterpenoids, were defined by comprehensive spectroscopic analysis and by X-ray crystallography. Using fluorescence-activated cell sorting (FACS) analysis, napyradiomycins 1–4 were observed to induce apoptosis in the colon adenocarcinoma cell line, HCT-116, indicating the possibility of a specific biochemical target for this class of cytotoxins. PMID:24328269

Farnaes, Lauge; Coufal, Nicole G.; Kauffman, Christopher A.; Rheingold, Arnold L.; DiPasquale, Antonio G.; Jensen, Paul R.; Fenical, William

2014-01-01

422

Generalized Fractional Order Derivatives, Its Properties and Applications  

E-print Network

The concept of fractional order derivative can be found in extensive range of many different subject areas. For this reason, the concept of fractional order derivative should be examined. After giving different methods mostly used in engineering and scientific applications, the omissions or errors of these methods will be discussed in this study. The mostly used methods are Euler, Riemann-Liouville and Caputo which are fractional order derivatives. The applications of these methods to constant and identity functions will be given in this study. Obtained results demonstrated that all of three methods have errors and deficiencies. In fact, the obtained results demonstrated that the methods given as fractional order derivatives are curve fitting methods or curve approximation methods. In this paper, we redefined fractional order derivative (FOD) by using classical derivative definition and L Hospital method, since classical derivative definition concluded in indefinite limit such as 0/0. The obtained definition is same as classical derivative definition in case of fractional order is equal to 1. This implies that definitions and theorems in this paper sound and complete. After defining the FOD concept, the applications of FOD for polynomial, exponential, trigonometric and logarithmic functions were handled in this study. The properties of FOD for positive monotonic increasing/decreasing functions were demonstrated in this paper. Another important point is that the relation between derivatives and complex functions were also verified in this paper.

Ali Karci

2013-06-20

423

Renormalization and unitarity in higher derivative and nonlocal gravity theories  

NASA Astrophysics Data System (ADS)

We review and discuss higher derivative and nonlocal theories of quantum gravity focusing on their UV and unitarity properties. We first consider the general fourth-order gravitational action, then actions containing derivatives up to any given fixed order, and discuss their UV divergences, fixed points and concomitant unitarity issues. This leads to a more general discussion of "asymptotic safety" and unitarity, which motivates the introduction of nonlocal theories containing derivatives to all orders arising from the expansion of entire functions. For such theories good UV behavior is visible at any finite truncation, but unitarity emerges only when derivatives to all orders are included.

Tomboulis, E. T.

2015-01-01

424

Production of Chemical Derivatives from Renewables  

SciTech Connect

The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corp., (LMER), Argonne National Laboratory (ANL), National Renewable Energy Laboratory (NREL), and Battelle Memorial Institute, operator of Pacific Northwest National Laboratory (PNNL), (collectively referred to as the 'Contractor'), and Applied Carbochemicals, Inc. (Participant) was to scale-up from bench results an economically promising and competitive process for the production of chemical derivatives from biologically produced succinic acid. The products that were under consideration for production from the succinic acid platform included 1,4-butanediol, {gamma}y-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Preliminary economic analyses indicated that this platform was competitive with the most recent petrochemical routes. The Contractors and participant are hereinafter jointly referred to as the 'Parties.' Research to date in succinic acid fermentation, separation and genetic engineering resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on preliminary laboratory findings and predicted catalytic parameters. At the time, the current need was to provide the necessary laboratory follow-up information to properly optimize, design and operate a pilot scale process. The purpose of the pilot work was to validate the integrated process, assure 'robustness' of the process, define operating conditions, and provide samples for potential customer evaluation. The data from the pilot scale process was used in design and development of a full scale production facility. A new strain, AFP111 (patented), discovered at ANL was tested and developed for process use at the Oak Ridge National Laboratory (ORNL) and ANL. The operability and product formation are attractive for this strain and effort was being directed at process development and optimization. Key to the transition from the fermentative production unit operation to the chemical catalysis is the 'clean-up' of fermentation broth, succinic acid formation from the salt, and succinic acid concentration. These steps are accomplished by a two-stage membrane ED separation process developed at AWL. Although the current process is well developed, possible modifications and optimization may be called for as development work continues in both the fermentation and catalysis areas. Research to date performed at PNNL has demonstrated that succinic acid can be converted to value added chemicals such as 1,4-butanediol, {gamma}-butyrolactone, N-methyl pyrrolidinone, and 2 pyrrolidinone with high conversion and selectivities. Continued research will be performed in catalyst development and reaction condition optimization to move this work from the bench scale to the pilot scale. All development of the process was guided by the NREL technoeconomic model. The model showed that direct aqueous phase catalysis of succinic acid to 1,4-butanediol, {gamma}-butyrolactone, and N-methyl pyrrolidinone provided significant economical advantages in the market, the margin, and the return on capital investment over existing petrochemical processes for production of these compounds. The model also provided the baseline for evaluating current laboratory research. As data from the bench and pilot work were made available the model was modified and appropriate sensitivities ran to determine impact of the process changes and optimization. The report will present the planned CRADA tasks followed by the results. The results section has an overall project summary follwed by more detailed reports from the participants. This is a nonproprietary report; additional proprietary information may be made available subject to acceptance of the appropriate proprietary information agreements.

Davison, Brian; Nghiem, John; Donnelly, Mark; Tsai, Shih-Perng; Frye, John; Landucci, Ron; Griffin, Michael

1996-06-01

425

Bioactive Phenylalanine Derivatives and Cytochalasins from the Soft Coral-Derived Fungus, Aspergillus elegans  

PubMed Central

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

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

426

Intra- and intermolecular hydrogen bonding in acetylacetone and benzoylacetone derived enaminone derivatives  

NASA Astrophysics Data System (ADS)

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.

Lazi?, Vedrana; Jurkovi?, Mihaela; Jedna?ak, Tomislav; Hrenar, Tomica; Vukovi?, Jelena Parlov; Novak, Predrag

2015-01-01

427

Enzymatic production and degradation of cheese-derived non-proteolytic aminoacyl derivatives.  

PubMed

Gamma-glutamyl-amino acids, lactoyl-amino acids and pyroglutamyl-amino acids, collectively named Non-Proteolytic Aminoacyl Derivatives (NPADs) are unusual aminoacyl derivatives of non-proteolytic origins found in consistent amount in several cheeses. Although their enzymatic origin arising from lactic acid bacteria has been demonstrated, the exact enzymes originating them, the ones eventually degrading them and also their resistance to digestive enzymes in the human gastrointestinal tract and in the blood serum after eventual absorption are still unknown. In this paper, pure enzymes and biological media were tested on NPAD and their aminoacidic precursors, for identifying the conditions favoring bioproduction and biodegradation of these compounds. Pure gamma-glutamyl-phenylalanine and its precursor (glutamic acid and phenylalanine), also in the isotopically labeled forms, were tested with Parmigiano-Reggiano extracts, blood serum and different pure enzymes, including typical digestion enzymes (pepsin, trypsin and chymotrypsin), gamma-glutamyl transpeptidase and carboxypeptidase. The data suggested that their production in cheese, and also their partial degradation, might be due to the action of peptidases and gamma-glutamyl transpeptidase. Anyway, under simulated gastrointestinal digestion and in blood serum these compounds turned out to be perfectly stable, suggesting a potential to be absorbed as such and possibly being transported to the body tissues. PMID:24337832

Bottesini, Chiara; Tedeschi, Tullia; Dossena, Arnaldo; Sforza, Stefano

2014-02-01

428

Derivatives of molecular electromagnetic properties using nonlocal susceptibility densities  

NASA Astrophysics Data System (ADS)

This thesis presents three analytic derivative relationships. The underlying concept of these three relationships is connecting the change of a molecular property to other well-defined molecular properties. The foundation of this work lies in nonlocal polarizability density theory. The nonlocal polarizability density characterizes the polarization at one point in a molecule due to its reaction with an electric field at another point in the molecule. In the first part, the derivative of the electronic hyperpolarizability with respect to a Cartesian nuclear coordinate is related to the nonlocal second hyperpolarizability density, the nuclear charge and the dipole propagator. The derivation uses the derivatives of the wavefunctions and operators that comprise the six- term hyperpolarizability. These derivatives, which are also derived, are substituted into the hyperpolarizability to yield a sixty-term expression. The initial result is manipulated algebraically in a nontrivial way to yield the equality. A brief review of hyper-Raman scattering theory is given. Recent applications of hyper-Raman scattering are considered. In the second part a new expression for the derivative of the polarization propagator with respect to an arbitrary coordinate is derived in terms of the quadratic polarization propagator and a sum of polarization propagators. The derivation involves calculating the derivative of a creation and annihilation operator pair with respect to an arbitrary parameter. Then the propagator derivative is calculated via the derivatives of many-electron wavefunctions. Past work calculating the derivatives of molecular properties using polarization propagator techniques is briefly reviewed. The third part concerns finding an expression for the derivative of the electronic magnetic moment with respect to nuclear momentum and its relationship to a nonlocal magnetizability density. The magnetizability density has a structure similar to the chemical shift. The relationship is found by considering the magnetic field produced by a moving nucleus as a perturbation on the electronic structure. The ground state wavefunctions are corrected to first order in perturbation theory using the nuclear magnetic field as the perturbation. The corrected wavefunctions are used to calculate the expectation value of the magnetic moment. When the derivative of this expectation value is taken with respect to nuclear momentum, its relationship with the nonlocal chemical shift density is uncovered. The result is correct when adiabatic wavefunctions that go beyond the Born- Oppenheimer approximation are used. The physical content of the equation is interpreted as a description of intramolecular magnetic response. Other possible paths to a complete susceptibility theory are considered. One path involves substitution of 4- currents into the definition of the nonlocal polarizability density. Other paths arise from an initial consideration of the relativistic Dirac equation and subsequent analysis using the Gordon decomposition and the Foldy-Wouthuysen transformation.

Tisko, Edmund Leo

429

17 CFR 39.5 - Information relating to derivatives clearing organization operations.  

Code of Federal Regulations, 2010 CFR

... false Information relating to derivatives clearing organization operations...COMMODITY FUTURES TRADING COMMISSION DERIVATIVES CLEARING ORGANIZATIONS § 39.5 Information relating to derivatives clearing organization...

2010-04-01

430

17 CFR 39.4 - Procedures for implementing derivatives clearing organization rules and clearing new products.  

Code of Federal Regulations, 2010 CFR

...false Procedures for implementing derivatives clearing organization rules and...COMMODITY FUTURES TRADING COMMISSION DERIVATIVES CLEARING ORGANIZATIONS § 39.4 Procedures for implementing derivatives clearing organization rules...

2010-04-01

431

17 CFR 37.8 - Information relating to transactions on derivatives transaction execution facilities.  

Code of Federal Regulations, 2010 CFR

...Information relating to transactions on derivatives transaction execution facilities...COMMODITY FUTURES TRADING COMMISSION DERIVATIVES TRANSACTION EXECUTION FACILITIES ...Information relating to transactions on derivatives transaction execution...

2010-04-01

432

Nanostructural and Transcriptomic Analyses of Human Saliva Derived Exosomes  

E-print Network

Nanostructural and Transcriptomic Analyses of Human Saliva Derived Exosomes Viswanathan Palanisamy1 Background: Exosomes, derived from endocytic membrane vesicles are thought to participate in cell, exosomes secreted in human saliva contain proteins and nucleic acids that could be exploited for diagnostic

Gimzewski, James

433

A Methodology for the Derivation of Parallel Programs  

E-print Network

A Methodology for the Derivation of Parallel Programs Joy Goodman Department of Computer Science, University of Glasgow Abstract. I am currently developing a methodology for deriving paral­ lel programs from am developing a methodology to address and help over­ come these problems. 2 The Methodology

Goodman, Joy

434

Advertising in Google Search Deriving a bidding strategy  

E-print Network

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

Boucherie, Richard J.

435

Diffraction behavior of photorefractive molecular materials containing phenothiazine derivatives  

Microsoft Academic Search

We report the diffraction behavior of the photorefractive (PR) molecular materials that contain the phenothiazine derivatives. Diphenylhydrazine and malononitrile were reacted with N-alkyl substituted phenothiazinyl aldehyde to provide charge transporting and nonlinear optical (NLO) molecules, respectively. In the molecular materials prepared with phenothiazine derivatives, we observed very unusual complementary gratings formed by the space charge fields of two types of

Dong Hoon Choi; Kwang Yong Oh; Woong Gi Jun; Jae Hong Kim; Suk-Ho Choi

2002-01-01

436

Soybean-Derived Biofuels and Home Heating Fuels  

Microsoft Academic Search

It is environmentally enticing to consider replacing or blending petroleum derived heating fuels with biofuels for many reasons. Major considerations include the soaring worldwide price of petroleum products, especially home heating oil, the toxicity of the petroleum-derived fuels and the environmental damage that leaking petroleum tanks afford. For these reasons, it has been suggested that domestic renewable energy sources be

GEORGE W. MUSHRUSH; JAMES H. WYNNE; HEATHER D. WILLAUER; CHRISTOPHER L. LLOYD

2006-01-01

437

Derivation Rules as Anti-Axioms in Modal Logic  

Microsoft Academic Search

We discuss a `negative' way of defining frame classes in (multi)modal logic, and address the question of whether these classes can be axiomatized by derivation rules, the `non-$\\\\xi$ rules', styled after Gabbay's Irreflexivity Rule. The main result of this paper is a metatheorem on completeness, of the following kind: If $\\\\Lambda$ is a derivation system having a set of axioms

Yde Venema

1993-01-01

438

Fractional Hamiltonian analysis of higher order derivatives systems  

E-print Network

The fractional Hamiltonian analysis of 1+1 dimensional field theory is investigated and the fractional Ostrogradski's formulation is obtained. The fractional path integral of both simple harmonic oscillator with an acceleration-squares part and a damped oscillator are analyzed. The classical results are obtained when fractional derivatives are replaced with the integer order derivatives.

Dumitru Baleanu; Sami I. Muslih; Kenan Tas

2006-12-07

439

Fractional Hamiltonian analysis of higher order derivatives systems  

SciTech Connect

The fractional Hamiltonian analysis of 1+1 dimensional field theory is investigated and the fractional Ostrogradski's formulation is obtained. The fractional path integral of both simple harmonic oscillator with an acceleration-squares part and a damped oscillator are analyzed. The classical results are obtained when fractional derivatives are replaced with the integer order derivatives.

Baleanu, Dumitru; Muslih, Sami I.; Tas, Kenan [Department of Mathematics and Computer Sciences, Faculty of Arts and Sciences, Cankaya University-06530, Ankara, Turkey and Institute of Space Sciences, P.O. Box, MG-23, R 76900, Magurele-Bucharest (Romania); Department of Physics, Al-Azhar University, Gaza, Palestine Israel and International Center for Theoretical Physics, Trieste (Italy); Department of Mathematics and Computer Sciences, Faculty of Arts and Sciences, Cankaya University-06530, Ankara (Turkey)

2006-10-15

440

An alternative derivation of Einstein's Doppler shift and aberration formulae  

E-print Network

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.

Jean Reignier

2009-02-06

441

On the second derivative of a Gaussian process envelope  

Microsoft Academic Search

In this paper we explore some dynamic characteristics of the envelope of a bandpass Gaussian process, which are of interest in wireless fading channels. Specifically, we show that unlike the first derivative, the second derivative of the envelope, which appears in a number of applications, does not exist in the traditional mean square sense. However, we prove that the envelope

Ali Abdi

2002-01-01

442

Highly Efficient Synthesis of Chiral -Amino Acid Derivatives via  

E-print Network

Highly Efficient Synthesis of Chiral -Amino Acid Derivatives via Asymmetric Hydrogenation Wenjun-TangPhos complex is an efficient hydrogenation catalyst for making chiral -amino acid derivatives. With the Rh -amino acids has drawn a great deal of attention due to its importance in biomedical research

Zhang, Xumu

443

On the evaluation of derivatives of Gaussian integrals  

NASA Technical Reports Server (NTRS)

We show that by a suitable change of variables, the derivatives of molecular integrals over Gaussian-type functions required for analytic energy derivatives can be evaluated with significantly less computational effort than current formulations. The reduction in effort increases with the order of differentiation.

Helgaker, Trygve; Taylor, Peter R.

1992-01-01

444

21 CFR 189.110 - Calamus and its derivatives.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2009-04-01 true Calamus and its derivatives. 189.110 Section 189.110 Food and Drugs FOOD...Addition or Use as Human Food § 189.110 Calamus and its derivatives. (a) Calamus is the dried rhizome of Acorus...

2010-04-01

445

21 CFR 189.135 - Cyclamate and its derivatives.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Cyclamate and its derivatives. 189.135 Section 189.135 Food and Drugs FOOD...Addition or Use as Human Food § 189.135 Cyclamate and its derivatives. (a) Calcium, sodium, magnesium and potassium...

2010-04-01

446

17 CFR 240.16c-4 - Derivative securities.  

Code of Federal Regulations, 2010 CFR

...Exchanges 3 2010-04-01 2010-04-01 false Derivative securities. 240.16c-4 Section 240.16c-4 Commodity...Certain Transactions from Section 16(c) § 240.16c-4 Derivative securities. Establishing or increasing a put...

2010-04-01

447

The Erroneous Derivative Examples of Eleventh Grade Students  

ERIC Educational Resources Information Center

The derivative is not only an important subject for mathematics but also is an important subject for engineering, physics, economy, chemistry, and statistics. Especially, mathematics depends on strongly preceding learning and the subject of derivative will be used in university education by all students. Therefore, it is one of the most important…

Gur, Hulya; Barak, Basak

2007-01-01

448

Calculation of Sensitivity Derivatives in an MDAO Framework  

NASA Technical Reports Server (NTRS)

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.

Moore, Kenneth T.

2012-01-01

449

DERIVATION OF FLUOROMETRIC CHLOROPHYLL AND PHEOPHYTIN EQUATIONS (JOURNAL VERSION)  

EPA Science Inventory

Equations for calculation of chlorophyll a and pheophytin a by fluorometry have been cited in a number of publications. None of them, however, includes the derivation of the equations to substantiate their validity. The derivation is given here to let the user apply the equations...

450

Frechet derivatives for shallow water ocean acoustic inverse problems  

NASA Astrophysics Data System (ADS)

For any inverse problem, finding a model fitting the data is only half the problem. Most inverse problems of interest in ocean acoustics yield nonunique model solutions, and involve inevitable trade-offs between model and data resolution and variance. Problems of uniqueness and resolution and variance trade-offs can be addressed by examining the Frechet derivatives of the model-data functional with respect to the model variables. Tarantola [Inverse Problem Theory (Elsevier, Amsterdam, 1987), p. 613] published analytical formulas for the basic derivatives, e.g., derivatives of pressure with respect to elastic moduli and density. Other derivatives of interest, such as the derivative of transmission loss with respect to attenuation, can be easily constructed using the chain rule. For a range independent medium the analytical formulas involve only the Green's function and the vertical derivative of the Green's function for the medium. A crucial advantage of the analytical formulas for the Frechet derivatives over numerical differencing is that they can be computed with a single pass of any program which supplies the Green's function. Various derivatives of interest in shallow water ocean acoustics are presented and illustrated by an application to the sensitivity of measured pressure to shallow water sediment properties. [Work supported by ONR.

Odom, Robert I.

2003-04-01

451

Potential of Novel EPO Derivatives in Limb Ischemia  

PubMed Central

Erythropoietin (EPO) has tissue-protective properties, but it increases the risk of thromboembolism by raising the haemoglobin concentration. New generation of EPO derivatives is tissue protective without the haematopoietic side effects. Preclinical studies have demonstrated their effectiveness and safety. This paper summarizes the development in EPO derivatives with emphasis on their potential use in critical limb ischaemia. PMID:22462027

Joshi, Dhiraj; Tsui, Janice; Yu, Rebekah; Shiwen, Xu; Selvakumar, Sadasivam; Abraham, David J.; Baker, Daryll M.

2012-01-01

452

Regioselective Enzymatic Carboxylation of Phenols and Hydroxystyrene Derivatives  

PubMed Central

The enzymatic carboxylation of phenol and styrene derivatives using (de)carboxylases in carbonate buffer proceeded in a highly regioselective fashion: Benzoic acid (de)carboxylases selectively formed o-hydroxybenzoic acid derivatives, phenolic acid (de)carboxylases selectively acted at the ?-carbon atom of styrenes forming (E)-cinnamic acids. PMID:22471935

2012-01-01

453

Derivation of phase statistics from the Mueller matrix  

Microsoft Academic Search

Experimental observations show a strong dependence of phase differences of scattering matrix elements on the physical parameters of random media. Here, the statistical behavior of the phase differences is studied for distributed targets. The pdfs of the phase differences are derived from the Mueller matrix of the target. In deriving the density functions, it is assumed that the real and

K. Sarabandi

1992-01-01

454

76 FR 3697 - Risk Management Requirements for Derivatives Clearing Organizations  

Federal Register 2010, 2011, 2012, 2013

...17 CFR Part 39 Risk Management Requirements for Derivatives...Part 39 RIN 3038-AC98 Risk Management Requirements for Derivatives...eligibility. 39.13 Risk management. 39.14 Settlement procedures...Reserved] 39.24 Governance fitness standards. 39.25...

2011-01-20

455

On explicit two-derivative Runge-Kutta methods  

NASA Astrophysics Data System (ADS)

The theory of Runge-Kutta methods for problems of the form y' = f(y) is extended to include the second derivative y'' = g(y): = f'(y)f(y). We present an approach to the order conditions based on Butcher's algebraic theory of trees (Butcher, Math Comp 26:79-106, 1972), and derive methods that take advantage of cheap computations of the second derivatives. Only explicit methods are considered here where attention is given to the construction of methods that involve one evaluation of f and many evaluations of g per step. Methods with stages up to five and of order up to seven including some embedded pairs are presented. The first part of the paper discusses a theoretical formulation used for the derivation of these methods which are also of wider applicability. The second part presents experimental results for non-stiff and mildly stiff problems. The methods include those with the computation of one second derivative (plus many first derivatives) per step, and embedded methods for changing stepsize as well as those involving one first derivative (plus many second derivatives) per step. The experiments have been performed on standard problems and comparisons made with some standard explicit Runge-Kutta methods.

Chan, Robert; Tsai, Angela

2010-03-01

456

Could It Be Possible to Replace DERIVE with MAXIMA?  

ERIC Educational Resources Information Center

In recent years, a considerable number of teachers in Spain have been using DERIVE to teach math subjects in High Schools and Universities. This software has been used by the authors of this work as a support tool in Mathematics courses for Engineering. Since Texas Instruments does not support DERIVE, we were faced with finding an alternative…

Garcia, Alfonsa; Garcia, Francisco; Rodriguez, Gerardo; de la Villa, Agustin

2011-01-01

457

21 CFR 189.120 - Cobaltous salts and its derivatives.  

...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 ,...

2014-04-01

458

21 CFR 189.120 - Cobaltous salts and its derivatives.  

Code of Federal Regulations, 2011 CFR

...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 ,...

2011-04-01

459

21 CFR 189.120 - Cobaltous salts and its derivatives.  

Code of Federal Regulations, 2013 CFR

...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 ,...

2013-04-01

460

21 CFR 189.120 - Cobaltous salts and its derivatives.  

Code of Federal Regulations, 2012 CFR

...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 ,...

2012-04-01

461

21 CFR 189.120 - Cobaltous salts and its derivatives.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true 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 ,...

2010-04-01

462

Cyclopentenone and furan derivative from the mycelia of Cordyceps cicadae.  

PubMed

A new cyclopentenone derivative, named as 2-(3-carboxy-2-hydroxypropyl)-3-methyl-2-cyclopentenone, and a new furan derivative, named as 5-(2-hydroxyethyl)-2-furanacetic acid, were isolated from the cultivated Cordyceps cicadae mycelia. Their structures were determined by spectroscopic methods, including 2D NMR analyses. PMID:18305360

Zhang, Shu-Wei; Xuan, Li-Jiang

2008-01-01

463

Instantaneous phase and frequency derived without user-defined parameters  

NASA Astrophysics Data System (ADS)

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.

Poggiagliolmi, E.; Vesnaver, A.

2014-12-01

464

Functional Characterization of Embryonic Stem Cell-Derived Endothelial Cells  

Microsoft Academic Search

Endothelial cells (EC) derived from embryonic stem cells (ESC) require additional functional characterization before they are used as a cell therapy in order to enhance their potential for engraftment and proliferation. We explore several physiologically relevant functions of ESC-derived EC (ESC-EC), such as its capacity to produce nitric oxide (NO), regulate permeability, activate and express surface molecules for the recruitment

Drew E. Glaser; Robert M. Gower; Nicholas E. Lauer; Kayan Tam; Alicia A. Blancas; Albert J. Shih; Scott I. Simon; Kara E. McCloskey

2011-01-01

465

A Radon-Nikodym derivative for almost subadditive set functions  

E-print Network

EA 4272 A Radon-Nikodym derivative for almost subadditive set functions Yann REBILLE (*) 2009,version1-17Dec2009 #12;A Radon-Nikodym derivative for almost subadditive set functions Yann R Nantes Cedex 3, France. Abstract In classical measure theory, the Radon-Nikodym theorem states

Paris-Sud XI, Université de

466

Biological activities of carbohydrate-branched chitosan derivatives.  

PubMed

Two types of biological activities of the carbohydrate-branched chitosan derivatives were investigated. One is the specific interaction with lectins and bacterium. The other is activation of canine polymorphonuclear leukocyte (PMN) cells. The specific bindings of the L-fucose-branched chitosan derivative with Ulex europaeus agglutinin I (UEA-I) and the N-acetyl-D-glucosamine-branched chitosan derivative with Concanavalin A (Con A) were confirmed by a surface plasmon resonance technique. The specific aggregation of the fluorescence-labeled L-fucose-branched chitosan derivative with Pseudomonas aeruginosa was observed by fluorescent microscopic observation. The aggregation would be attributed to the specific binding between the L-fucose-branched chitosan derivative and PA-II receptor on the cell surface of P. aeruginosa. The influence of the chitosan derivatives on the active oxygen species generation from canine PMN cells was also investigated by the luminol-aided chemiluminescence method. The chemiluminescence responses depended on the degree of substitution and water solubility of the chitosan derivatives. The water-insoluble chitosan derivatives would stimulate the PMN cells by a phagocytosis mechanism, and the water-soluble ones would sensitize the PMN cells by a priming mechanism. PMID:11777384

Morimoto, M; Saimoto, H; Usui, H; Okamoto, Y; Minami, S; Shigemasa, Y

2001-01-01

467

Derivative of Area Equals Perimeter--Coincidence or Rule?  

ERIC Educational Resources Information Center

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:…

Zazkis, Rina; Sinitsky, Ilya; Leikin, Roza

2013-01-01

468

Extracting Information from the Market to Price the Weather Derivatives  

E-print Network

Extracting Information from the Market to Price the Weather Derivatives Hélène Hamisultane. Because their underlying is not a traded asset, they cannot be priced by using the Black and Scholes formula. The market is said to be incomplete for the weather derivatives. Other pricing methods were

Paris-Sud XI, Université de

469

A Climatology of Surface Radiation Budget Derived from Satellite Data  

Microsoft Academic Search

Climatological averages of surface radiation budget parameters, namely, the shortwave and longwave surface radiative fluxes, have been derived for each month of the year on a global scale. These climatological averages were derived from an 8-yr (96 month) time series of monthly average fluxes. The monthly averages were computed using fast radiation parameterizations and satellite data from the International Satellite

Shashi K. Gupta; Nancy A. Ritchey; Anne C. Wilber; Charles H. Whitlock; Gary G. Gibson; Paul W. Stackhouse Jr.

1999-01-01

470

PRICING PRECIPITATION BASED DERIVATIVES RENE CARMONA AND PAVEL DIKO  

E-print Network

PRICING PRECIPITATION BASED DERIVATIVES REN´E CARMONA AND PAVEL DIKO ABSTRACT. We consider the problem of pricing a derivative contract written on the precipitation at a specific location during of the underlying precipitation. Our model is based on pulse Poisson process models widely used in hydrology. We

Carmona, Rene

471

Shear Viscosity to Entropy Density Ratio in Six Derivative Gravity  

E-print Network

We calculate shear viscosity to entropy density ratio in presence of four derivative (with coefficient $\\alpha'$) and six derivative (with coefficient $\\alpha'^2$) terms in bulk action. In general, there can be three possible four derivative terms and ten possible six derivative terms in the Lagrangian. Among them two four derivative and eight six derivative terms are ambiguous, i.e., these terms can be removed from the action by suitable field redefinitions. Rest are unambiguous. According to the AdS/CFT correspondence all the unambiguous coefficients (coefficients of unambiguous terms) can be fixed in terms of field theory parameters. Therefore, any measurable quantities of boundary theory, for example shear viscosity to entropy density ratio, when calculated holographically can be expressed in terms of unambiguous coefficients in the bulk theory (or equivalently in terms of boundary parameters). We calculate $\\eta/s$ for generic six derivative gravity and find that apparently it depends on few ambiguous coefficients at order $\\alpha'^2$. We calculate six derivative corrections to central charges $a$ and $c$ and express $\\eta/s$ in terms of these central charges and unambiguous coefficients in the bulk theory.

Nabamita Banerjee; Suvankar Dutta

2009-04-01

472

Synthesis and characterization of styrylchromone derivatives as ?-amyloid imaging agents  

Microsoft Academic Search

Several promising agents have been synthesized and evaluated for in vivo imaging probes of ?-amyloid plaques in Alzheimer’s disease (AD) brain. Recently, we have developed flavone derivatives, which possess the basic structure of the 2-phenylchromone, as useful candidates for amyloid imaging agents. In an attempt to further develop novel tracers, we synthesized and evaluated a series of 2-styrylchromone derivatives, which

Masahiro Ono; Yoshifumi Maya; Mamoru Haratake; Morio Nakayama

2007-01-01

473

The impact of energy derivatives on the crude oil market  

Microsoft Academic Search

We examine the effects of energy derivatives trading on the crude oil market. There is a common public and regulatory perception that derivative securities increase volatility and can have a destabilizing effect on the underlying market. Consistent with this view, we find an abnormal increase in volatility for three consecutive weeks following the introduction of NYMEX crude oil futures. While

Jeff Fleming; Barbara Ostdiek

1999-01-01

474

Derivation, propagation and differentiation of human embryonic stem cells  

Microsoft Academic Search

Embryonic stem (ES) cells are in vitro cultivated pluripotent cells derived from the inner cell mass (ICM) of the embryonic blastocyst. Attesting to their pluripotency, ES cells can be differentiated into representative derivatives of all three embryonic germ layers (endoderm, ectoderm and mesoderm) both in vitro and in vivo. Although mouse ES cells have been studied for many years, human

Brock J. Conley; Julia C. Young; Alan O. Trounson; Richard Mollard

2004-01-01

475

Metal complexation by chitosan and its derivatives: a review  

Microsoft Academic Search

One of the major applications of chitosan and its many derivatives is based on its ability to bind strongly heavy and toxic metal ions. This article reviews the various classes of chitosan derivatives and compares their ion binding abilities under varying conditions, as well as the analytical methods to analyze them, the sorption mechanism, and structural analysis of the metal

A. J Varma; S. V Deshpande; J. F Kennedy

2004-01-01

476

Atomic Force Mechanobiology of Pluripotent Stem Cell-Derived Cardiomyocytes  

Microsoft Academic Search

We describe a method using atomic force microscopy (AFM) to quantify the mechanobiological properties of pluripotent, stem cell-derived cardiomyocytes, including contraction force, rate, duration, and cellular elasticity. We measured beats from cardiomyocytes derived from induced pluripotent stem cells of healthy subjects and those with dilated cardiomyopathy, and from embryonic stem cell lines. We found that our AFM method could quantitate

Jianwei Liu; Ning Sun; Marc A. Bruce; Joseph C. Wu; Manish J. Butte

2012-01-01

477

Pricing temperature-based weather derivatives in China  

Microsoft Academic Search

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

Ahmet Göncü

2012-01-01

478

Quantum Hydrodynamic models derived from the entropy principle  

E-print Network

Quantum Hydrodynamic models derived from the entropy principle Pierre Degond(1) , Florian M´ehats(1 In this work, we give an overview of recently derived quantum hydrody- namic and diffusion models. A quantum local equilibrium is defined as a minimizer of the quantum entropy subject to local moment constraints

Méhats, Florian

479

Quantum Hydrodynamic models derived from the entropy principle  

E-print Network

Quantum Hydrodynamic models derived from the entropy principle Pierre Degond, Florian M´ehats, and Christian Ringhofer Abstract. In this work, we give an overview of recently derived quantum hydrodynamic and diffusion models. A quantum local equilibrium is defined as a minimizer of the quantum entropy subject

Ringhofer, Christian

480

Fréchet Derivatives For Curved Interfaces In the Ray Approximation  

Microsoft Academic Search

SUMMARY The sensitivity of ray and beam theoretical seismograms to changes in velocity models and curved interfaces is discussed in this paper. Previous results from Nowack & Lutter (1988) give the derivatives of travel-time and ray amplitude with respect to changes of smoothly varying velocities. These derivatives are required to perform linearized maximum likelihood inversions for structure. In the ray

Robert L. Nowack; Jeff A. Lyslo

1989-01-01

481

Silole derivatives: relationships between molecular arrangement and OLED efficiency  

E-print Network

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

Paris-Sud XI, Université de

482

Transformation relations for second derivatives of travel time  

E-print Network

Transformation relations for second derivatives of travel time in anisotropic media Vlastislav In the computation of paraxial travel times and Gaussian beams, the basic role is played by second derivatives of the travel-time field at the reference ray . These deriva- tives can be determined by dynamic ray tracing

Cerveny, Vlastislav

483

Synthesis of osteotropic hydroxybisphosphonate derivatives of fluoroquinolone antibacterials.  

PubMed

1-Hydroxybisphosphonate derivatives of ciprofloxacin, gatifloxacin and moxifloxacin have been synthesized using Cu(I) catalyzed azide-alkyne 1,3-dipolar cycloaddition reaction. The 1,2,3-triazol linked hydroxybisphosphonate derivative of ciprofloxacin exhibited antibacterial activity comparable to the parent antibiotic and all fluoroquinolone-bisphosphonates displayed osteotropic properties in a bone model. PMID:22093760

McPherson, James C; Runner, Royce; Buxton, Thomas B; Hartmann, John F; Farcasiu, Dan; Bereczki, Ilona; Roth, Erzsébet; Tollas, Szilvia; Ostorházi, Eszter; Rozgonyi, Ferenc; Herczegh, Pál

2012-01-01

484

BPS states in supersymmetric chiral models with higher derivative terms  

NASA Astrophysics Data System (ADS)

We study the higher derivative chiral models with four supercharges and Bogomol'nyi-Prasad-Sommerfield (BPS) states in these models. The off-shell Lagrangian generically includes higher powers of the auxiliary fields F , which causes distinct on-shell branches associated with the solutions to the auxiliary fields equation. We point out that the model admits a supersymmetric completion of arbitrary higher derivative bosonic models of a single complex scalar field, and an arbitrary scalar potential can be introduced even without superpotentials. As an example, we present a supersymmetric extension of the Faddeev-Skyrme model without four time derivatives, in contrast to the previously proposed supersymmetric Faddeev-Skyrme-like model containing four time derivatives. In general, higher derivative terms together with a superpotential result in deformed scalar potentials. We find that higher derivative corrections to 1 /2 BPS domain walls and 1 /2 BPS lumps are exactly canceled out, while the 1 /4 BPS lumps (as compact baby Skyrmions) depend on a characteristic feature of the higher derivative models. We also find a new 1 /4 BPS condition for domain wall junctions, which generically receives higher derivative corrections.

Nitta, Muneto; Sasaki, Shin

2014-11-01

485

Bulk modulus of semiconductors and its pressure derivatives  

Microsoft Academic Search

Expressions for the bulk modulus and its first and second pressure derivatives for group I–VII, II–VI, III–V and IV–IV semiconductor binary compounds are derived using an ab initio pseudopotential approach to the total crystal energy within the framework of local density functional formalism. The computed results are very close to the available experimental data.

G. Misra; P. Tripathi; S. C. Goyal

2007-01-01

486

Derivatives of rational Bezier curves M. S. Floater  

E-print Network

Derivatives of rational B´ezier curves M. S. Floater Centre for Industrial Research Forskningsveien are presented which express the derivative of a rational B´ezier curve in terms of its control points and weights. These equations are natural generali- sations of the non-rational case and various properties

Floater, Michael S.

487

Synthesis of (-)-arctigenin derivatives and their anticancer activity.  

PubMed

The natural dibenzylbutyrolactone type lignanolide (-)-arctigenin, which was prepared from fructus arctii, showed obvious anticancer activity. The synthesis of four new (-)-arctigenin derivatives and their anticancer bioactivities were examined. The structures of the four new synthetic derivatives were elucidated. PMID:21867457

Gui-Rong, Chen; Li-Ping, Cai; De-Qiang, Dou; Ting-Guo, Kang; Hong-Fu, Li; Fu-Rui, Li; Ning, Jiang

2012-01-01

488

NOVEL SLURRY PHASE DIESEL CATALYSTS FOR COAL-DERIVED SYNGAS  

SciTech Connect

This report describes research conducted to support the DOE program in novel slurry phase catalysts for converting coal-derived synthesis gas to diesel fuels. The primary objective of this research program is to develop attrition resistant catalysts that exhibit high activities for conversion of coal-derived syngas.

Dr. Dragomir B. Bukur; Dr. Ketil Hanssen; Alec Klinghoffer; Dr. Lech Nowicki; Patricia O'Dowd; Dr. Hien Pham; Jian Xu

2001-01-07

489

Pharmacology of endothelium-derived nitric oxide and nitrovasodilators.  

PubMed Central

Nitric oxide is the active chemical species responsible for the vasodilator action of nitroglycerin, nitroprusside, and related nitrovasodilators. The most potent vasodilator and inhibitor of platelet aggregation known, nitric oxide was recently discovered to occur endogenously as the endothelium-derived relaxing factor. The pharmacology of endothelium-derived nitric oxide is virtually identical to that of the clinically used nitrovasodilators. Although endothelium-derived relaxing factor or endothelium-derived nitric oxide seems to be important in animals, its significance in humans still needs to be shown. We review the recent discoveries in the identification, biosynthesis, metabolism, and biologic actions of endothelium-derived nitric oxide, its significance in humans, and its relation to the clinically used nitrovasodilators. PMID:1902612

Ignarro, L. J.; Ross, G.; Tillisch, J.

1991-01-01

490

Synthesis and antiproliferative assay of norcantharidin derivatives in cancer cells.  

PubMed

Diels-Alder reaction between furan and maleic anhydride resulted in 5,6-dehydro norcantharidin, then norcantharidin was obtained by reduction. The substituted-carboxylic acid was condensed with N-aminothiourea in presence of phosphorus oxychloride, yielding 2-amino-1,3,4-thiadiazole derivatives. Novel norcantharidin derivatives were synthesized with acylation, then intramolecular condensation using norcantharidin (or 5,6-dehydro norcantharidin) and 2-amino- 1,3,4-thiadiazole derivatives. All the target compounds were confirmed by IR, (1)HNMR, ESI-MS and were reported for the first time. Norcantharidin derivatives antiproliferative assay was tested by MTT method against A549 and PC-3 cell lines. The results showed that all the norcantharidin derivatives displayed moderate inhibitory activities. PMID:23909288

Tu, Guo Gang; Zhan, Jian Feng; Lv, Qiao Li; Wang, Jia Qi; Kuang, Bin Hai; Li, Shao Hua

2014-06-01

491

Ion-exchange derivatives of Spheron. V. Sulphate and sulpho derivatives.  

PubMed

Using various reactions, strongly acidic derivatives of Spheron of the sulphate and sulpho types were prepared with nominal capacities between 0.37 and 2.0 mequiv./g. They were characterized by their capacities for small ions, by their static and dynamic capacities for proteins, by elemental analysis, by their working volumes and specific internal surface areas. The differences between the nominal capacities calculated theoretically from the sulphur contents and the measured values are discussed, as are the relationships between the nominal capacities for small ions and the static and dynamic capacities for proteins. The chromatographic properties of the cation exchangers are illustrated by the separation of an artificial mixture of proteins (serum albumin, chymotrypsinogen and lysozyme) at various pH values, and of a natural mixture of egg-white proteins. The separation of active enzymes is also reported. Sulphobutyl-Spheron was tested also as a catalyst for the esterification of alcohols. PMID:6548758

Mikes, O; Strop, P; Hostomská, Z; Smrz, M; Slováková, S; Coupek, J

1984-09-28

492

Synthesis and antibacterial activity evaluation of two androgen derivatives.  

PubMed

In this study two androgen derivatives were synthesized using several strategies; the first stage an aza-steroid derivative (3) was developed by the reaction of a testosterone derivative (1) with thiourea (2) in presence of hydrogen chloride. The second step, involves the synthesis of an amino-steroid derivative (4) by the reaction of 1 with 2 using boric acid as catalyst. The third stage was achieved by the preparation of an aminoaza-androgen derivative (6) by the reaction of 3 with ethylenediamine using boric acid as catalyst. In addition, the compound 6 was made reacting with dihydrotestosterone to form a new androgen derivative (7) in presence of boric acid. The following step was achieved by the reaction of 7 with chloroacetyl chloride to synthesize an azetidinone-androgen derivative (8) using triethylamine as catalyst. Additionally, a thiourea-androgen derivative (9) was synthetized by the reaction of 4 with dihydrotestosterone using boric acid as catalyst. Finally, the compound 9 was made reacting with chloroacetyl chloride in presence of triethylamine to synthesize a new azetidinone-androgen derivative (10). On the other hand, antibacterial activity of compounds synthesized was evaluated on Gram negative (Escherichia coli and Vibrio cholerae) and Gram positive (Staphylococos aureus) bacteria. The results indicate that only the compound 3 and 8 decrease the growth bacterial of E. coli and V. cholerae. Nevertheless, growth bacterial of S. aureus was not inhibited by these compounds. These data indicate that antibacterial activity exerted by the compounds 3 and 8 depend of their structure chemical in comparison with the controls and other androgen derivatives that are involved in this study. PMID:25448363

Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Elodia, García-Cervera; Eduardo, Pool-Gómez; Maria, López-Ramos; Marcela, Rosas-Nexticapa; Lenin, Hau-Heredia; Bety, Sarabia-Alcocer

2015-01-01

493

Preparation and Characterization of Fluorescent Derivatives of Lysozyme  

NASA Technical Reports Server (NTRS)

Fluorescence is one of the most versatile and powerful tools for the study of macromolecules. However, its use in macromolecular crystal growth studies is hampered by the necessity of preparing fluorescent derivatives where the probe does not markedly affect the crystal packing. Alternatively, one can prepare derivatives of limited utility if it is known that they will not affect the specific goals of a given study. We have prepared a number of fluorescent derivatives of chicken egg white lysozyme, covalently attaching fluorescent probes to two different sites on the protein molecule. The first site is the side chain carboxyl group of ASP 101. Amine containing probes such as lucifer yellow, cascade blue, and 5- (2-aminoethyl) aminonapthalene-l-sulfonic acid (EDANS) have been attached using a carbodiimide coupling procedure. ASP 101 lies within the active site cleft, and it is believed that the probes are "buried" within that cleft. This is supported by the fact that all such derivatives have been found to crystallize, with the crystals being fluorescent. Tetragonal crystals of the lucifer yellow derivative have been found to diffract to at least 1.9 A resolution. X-ray diffraction data has been acquired and we are now working on the structure of this derivative. The second group of derivatives is to the N-terminal amine group. The derivatization reaction is performed by using a succinimidyl ester of the probe to be attached. Fluorescent probes such as pyrene acetic acid, 5-carboxyfluorescein, and Oregon green have been attached to this site. We have had little success in crystallizing these derivatives, probably because this site is part of the contact region between the 43 helix chains. However, these sites do not interfere with formation of the 43 helices and the derivatives are suitable for study of their formation in solution. The derivatives are being characterized by steady state and lifetime fluorescence methods, and the presentation will discuss these results.

Smith, Lori; Pusey, Marc

1998-01-01

494

Diketopiperazine Derivatives from the Marine-Derived Actinomycete Streptomyces sp. FXJ7.328  

PubMed Central

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

Wang, Pei; Xi, Lijun; Liu, Peipei; Wang, Yi; Wang, Wei; Huang, Ying; Zhu, Weiming

2013-01-01

495

Christiana Honsberg Derivation of the ideal diode equation for solar cells Derivation of the Ideal Diode Equation for Photovoltaics  

E-print Network

Christiana Honsberg Derivation of the ideal diode equation for solar cells Derivation of the Ideal of the ideal diode equation for solar cells General Procedure using the depletion approximation: Divide is confined to a particular region. (2) No free carriers (n(x), p(x) = 0 ) in depletion region. We can assume

Honsberg, Christiana

496

Consistent thermodynamic derivative estimates for tabular equations of state.  

PubMed

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce the consistency condition and its derivatives. The consistency condition is important for the computation of various dimensionless parameters of an EOS that may involve derivatives of up to second order which are important for the development of more sensitive artificial viscosities and Riemann solvers that accurately model shock structure in regions near phase transitions. We describe a table interface based on the tuned regression method, which is derived from a constrained local least-squares regression technique. It is applied to several SESAME EOS showing how the consistency and stability conditions can be satisfied to round-off while computing first and second derivatives with demonstrated second-order convergence. An improvement of 14 orders of magnitude over conventional derivatives is demonstrated, although the method is apparently two orders of magnitude slower, due to the fact that every evaluation requires solving an 11-dimensional nonlinear system. Application is made to the computation of the fundamental derivative. PMID:16907020

Dilts, Gary A

2006-06-01

497

Extraction of stability and control derivatives from orbiter flight data  

NASA Technical Reports Server (NTRS)

The Space Shuttle Orbiter has provided unique and important information on aircraft flight dynamics. This information has provided the opportunity to assess the flight-derived stability and control derivatives for maneuvering flight in the hypersonic regime. In the case of the Space Shuttle Orbiter, these derivatives are required to determine if certain configuration placards (limitations on the flight envelope) can be modified. These placards were determined on the basis of preflight predictions and the associated uncertainties. As flight-determined derivatives are obtained, the placards are reassessed, and some of them are removed or modified. Extraction of the stability and control derivatives was justified by operational considerations and not by research considerations. Using flight results to update the predicted database of the orbiter is one of the most completely documented processes for a flight vehicle. This process followed from the requirement for analysis of flight data for control system updates and for expansion of the operational flight envelope. These results show significant changes in many important stability and control derivatives from the preflight database. This paper presents some of the stability and control derivative results obtained from Space Shuttle flights. Some of the limitations of this information are also examined.

Iliff, Kenneth W.; Shafer, Mary F.

1993-01-01

498

Synthesis and antifungal properties of sulfanilamide derivatives of chitosan.  

PubMed

Sulfanilamide derivatives of chitosan (2-(4-acetamido-2-sulfanimide)-chitosan (HSACS, LSACS), 2-(4-acetamido-2-sulfanimide)-6-sulfo-chitosan (HSACSS, LSACSS) and 2-(4-acetamido-2-sulfanimide)-6-carboxymethyl-chitosan (HSACMCS, LSACMCS)) were prepared using different molecular weights of chitosan (CS), carboxymethyl chitosan (CMCS) and chitosan sulfates (CSS) reacted with 4-acetamidobenzene sulfonyl chloride in dimethylsulfoxide solution. The structures of the derivatives were characterized by FT-IR spectroscopy and elemental analysis, which showed that the substitution degree of sulfanilamide group of HSACS, HSACSS, HSACMCS, LSACS, LSACSS and LSACMCS were 0.623, 0.492, 0.515, 0.576, 0.463 and 0.477, respectively. The solubility of the derivatives (pH<7.5) was higher than that of chitosan (pH<6.5). The antifungal activities of the derivatives against Aiternaria solani and Phomopsis asparagi were evaluated based on the method of Jasso et al. in the experiment. The results indicated that all the prepared sulfanilamide derivatives had a significant inhibiting effect on the investigated fungi in the polymer concentration range from 50 to 500 microg mL(-1). The antifungal activities of the derivatives increased with increasing the molecular weight, concentration or the substitution degree. The sulfanilamide derivatives of CS, CMCS and CSS show stronger antifungal activities than CS, CMCS and CSS. PMID:17765881

Zhong, Zhimei; Chen, Rong; Xing, Ronge; Chen, Xiaolin; Liu, Song; Guo, Zhanyong; Ji, Xia; Wang, Lin; Li, Pengcheng

2007-11-26

499

Learning course adjustments during arm movements with reversed sensitivity derivatives  

PubMed Central

Background To learn, a motor system needs to know its sensitivity derivatives, which quantify how its neural commands affect motor error. But are these derivatives themselves learned, or are they known solely innately? Here we test a recent theory that the brain's estimates of sensitivity derivatives are revisable based on sensory feedback. In its simplest form, the theory says that each control system has a single, adjustable estimate of its sensitivity derivatives which affects all aspects of its task, e.g. if you learn to reach to mirror-reversed targets then your revised estimate should reverse not only your initial aiming but also your online course adjustments when the target jumps in mid-movement. Methods Human subjects bent a joystick to move a cursor to a target on a computer screen, but the cursor's motion was reversed relative to the joystick's. The target jumped once during each movement. Subjects had up to 4000 trials to practice aiming and responding to target jumps. Results All subjects learned to reverse both initial aiming and course adjustments. Conclusions Our study confirms that sensitivity derivatives can be relearned. It is consistent with the idea of a single, all-purpose estimate of those derivatives; and it suggests that the estimate is a function of context, as one would expect given that the true sensitivity derivatives may vary with the state of the controlled system, the target, and the motor commands. PMID:21110876

2010-01-01

500

Galerkin boundary integral method for evaluating surface derivatives  

NASA Astrophysics Data System (ADS)

A Galerkin boundary integral procedure for evaluating the complete derivative, e.g., potential gradient or stress tensor, is presented. The expressions for these boundary derivatives involve hypersingular kernels, and the advantage of the Galerkin approach is that the integrals exist when a continuous surface interpolation is employed. As a consequence, nodal derivative values, at smooth surface points or at corners, can be obtained directly. This method is applied to the problem of electromigration-driven void dynamics in thin film aluminum interconnects. In this application, the tangential component of the electric field on the boundary is required to compute the flux of atoms at the void surface.

Gray, L. J.; Maroudas, D.; Enmark, M. N.