Synthesis of the thymidine building blocks for a nonhydrolyzable DNA analogue

1992 ◽  
Vol 70 (5) ◽  
pp. 1573-1580 ◽  
Author(s):  
Stephen H. Kawai ◽  
Daguang Wang ◽  
George Just
Keyword(s):  
Building Blocks ◽  
The Third ◽  
Branched Chain

The 3′-deoxy-3′-C-(2″-hydroxyethyl)thymidine derivatives 4 and 13 were efficiently synthesized from either thymidine via a known 3′-radical allylation, or from the branched-chain furanose 5 involving the removal of the 2′-hydroxyl after stereospecific nucleosidation. The 5′-deoxy-5′-thiothymidine 20 was prepared via a regiospecific Mitsunobu coupling, providing the third unit required for the synthesis of sulfide-linked DNA analogues.

Enhancing the Portal Experience

2010 ◽  
Vol 2 (2) ◽  
pp. 12-25 ◽  
Author(s):  
Joe Lamantia
Keyword(s):  
Best Practices ◽  
User Experience ◽  
Building Blocks ◽  
Business Practices ◽  
Design Framework ◽  
Enterprise 2.0 ◽  
Social Business ◽  
The Third ◽  
User Value

This article presents strategies for enhancing the long-term business and user value of portals as the third in a series of articles describing a Portal Design Framework. This article identifies essential Enterprise 2.0 functionality for collaboration and dialog—capabilities that support emerging Social Business practices—included in the Building Blocks Design Framework. The author discusses portal management and governance best practices and describes strategies for maintaining and enhancing the user experience of portals designed using the Building Blocks Framework.

Amino acid transportation, sensing and signal transduction in the mammary gland: key molecular signalling pathways in the regulation of milk synthesis

2020 ◽  
Vol 33 (2) ◽  
pp. 287-297
Author(s):  
Zhihui Wu ◽  
Jinghui Heng ◽  
Min Tian ◽  
Hanqing Song ◽  
Fang Chen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mammary Gland ◽  
Milk Protein ◽  
Building Blocks ◽  
Branched Chain Amino Acids ◽  
Signalling Pathways ◽  
Recent Advances ◽  
Branched Chain ◽  
Molecular Signalling Pathways

AbstractThe mammary gland, a unique exocrine organ, is responsible for milk synthesis in mammals. Neonatal growth and health are predominantly determined by quality and quantity of milk production. Amino acids are crucial maternal nutrients that are the building blocks for milk protein and are potential energy sources for neonates. Recent advances made regarding the mammary gland further demonstrate that some functional amino acids also regulate milk protein and fat synthesis through distinct intracellular and extracellular pathways. In the present study, we discuss recent advances in the role of amino acids (especially branched-chain amino acids, methionine, arginine and lysine) in the regulation of milk synthesis. The present review also addresses the crucial questions of how amino acids are transported, sensed and transduced in the mammary gland.

WENO-TVD schemes for hyperbolic conservation laws

Analysis ◽  
2007 ◽  
Vol 27 (1) ◽  
Author(s):  
Yousef Hashem Zahran
Keyword(s):  
Conservation Laws ◽  
Hyperbolic Conservation Laws ◽  
Building Blocks ◽  
Second Order ◽  
Third Order ◽  
Weno Schemes ◽  
Hyperbolic Conservation ◽  
Systematic Assessment ◽  
The Third ◽  
Seventh Order

The purpose of this paper is twofold. Firstly we carry out a modification of the finite volume WENO (weighted essentially non-oscillatory) scheme of Titarev and Toro [14] and [15].This modification is done by using two fluxes as building blocks in spatially fifth order WENO schemes instead of the second order TVD flux proposed by Titarev and Toro [14] and [15]. These fluxes are the second order TVD flux [19] and the third order TVD flux [20].Secondly, we propose to use these fluxes as a building block in spatially seventh order WENO schemes. The numerical solution is advanced in time by the third order TVD Runge–Kutta method. A way to extend these schemes to general systems of nonlinear hyperbolic conservation laws, in one and two dimension is presented. Systematic assessment of the proposed schemes shows substantial gains in accuracy and better resolution of discontinuities, particularly for problems involving long time evolution containing both smooth and non-smooth features.

Oligosiloxanediols as building blocks for supramolecular chemistry: hydrogen-bonded adducts with amines form supramolecular structures in zero, one and two dimensions

2000 ◽  
Vol 56 (2) ◽  
pp. 273-286 ◽  
Author(s):  
Brian O'Leary ◽  
Trevor R. Spalding ◽  
George Ferguson ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonds ◽  
Supramolecular Chemistry ◽  
Building Blocks ◽  
Two Dimensions ◽  
Supramolecular Structures ◽  
Structural Motif ◽  
Two Dimensional ◽  
The Third ◽  
A Chain ◽  
Hydrogen Bonded

The structure of 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol–pyrazine (4/1), (C36H32O4Si3)4·C4H4N2 (1), contains finite centrosymmetric aggregates; the diol units form dimers, by means of O—H...O hydrogen bonds, and pairs of such dimers are linked to the pyrazine by means of O—H...N hydrogen bonds. In 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol–pyridine (2/3), (C36H32O4Si3)2·(C5H5N)3 (2), the diol units are linked into centrosymmetric pairs by means of disordered O—H...O hydrogen bonds: two of the three pyridine molecules are linked to the diol dimer by means of ordered O—H...N hydrogen bonds, while the third pyridine unit, which is disordered across a centre of inversion, links the diol dimers into a C 3 3(9) chain by means of O—H...N and C—H...O hydrogen bonds. In 1,1,3,3-tetraphenyldisiloxane-1,3-diol–hexamethylenetetramine (1/1), (C24H22O3Si2)·C6H12N4 (3), the diol acts as a double donor and the hexamethylenetetramine acts as a double acceptor in ordered O—H...N hydrogen bonds and the structure consists of C 2 2(10) chains of alternating diol and amine units. In 1,1,3,3-tetraphenyldisiloxane-1,3-diol–2,2′-bipyridyl (1/1), C24H22O3Si2·C10H8N2 (4), there are two independent diol molecules, both lying across centres of inversion and therefore both containing linear Si—O—Si groups: each diol acts as a double donor of hydrogen bonds and the unique 2,2′-bipyridyl molecule acts as a double acceptor, thus forming C 2 2(11) chains of alternating diol and amine units. The structural motif in 1,1,3,3-tetraphenyldisiloxane-1,3-diol–pyrazine (2/1), (C24H22O3Si2)2·C4H4N2 (5), is a chain-of-rings: pairs of diol molecules are linked by O—H...O hydrogen bonds into centrosymmetric R 2 2(12) dimers and these dimers are linked into C 2 2(13) chains by means of O—H...N hydrogen bonds to the pyrazine units. 1,1,3,3-Tetraphenyldisiloxane-1,3-diol–pyridine (1/1), C24H22O3Si2·C5H5N (6), and 1,1,3,3-tetraphenyldisiloxane-1,3-diol–pyrimidine (1/1), C24H22O3Si2·C4H4N2 (7), are isomorphous: in each compound the amine unit is disordered across a centre of inversion. The diol molecules form C(6) chains, by means of disordered O—H...O hydrogen bonds, and these chains are linked into two-dimensional nets built from R 6 6(26) rings, by a combination of O—H...N and C—H...O hydrogen bonds.

scholarly journals The Needlet CMB Trispectrum

2014 ◽  
Vol 10 (S306) ◽  
pp. 48-50 ◽  
Author(s):  
Antonino Troja ◽  
Simona Donzelli ◽  
Davide Maino ◽  
Domenico Marinucci
Keyword(s):  
Correction Term ◽  
Building Blocks ◽  
Statistical Properties ◽  
Efficient Estimation ◽  
Third Order ◽  
Instrumental Noise ◽  
The Third ◽  
Natural Building

AbstractWe propose a computationally feasible estimator for the needlet trispectrum, which develops earlier work on the bispectrum by Donzelli et al. (2012). Our proposal seems to enjoy a number of useful properties, in particular a) the construction exploits the localization properties of the needlet system, and hence it automatically handles masked regions; b) the procedure incorporates a quadratic correction term to correct for the presence of instrumental noise and sky-cuts; c) it is possible to provide analytic results on its statistical properties, which can serve as a guidance for simulations. The needlet trispectrum we present here provides the natural building blocks for the efficient estimation of nonlinearity parameters on CMB data, and in particular for the third order constants gNL and τNL.

ChemInform Abstract: Synthesis of Branched Chain Cyclitols: Preparation of Some Useful Chiral Building Blocks.

ChemInform ◽  
2010 ◽  
Vol 23 (43) ◽  
pp. no-no
Author(s):  
J. MARCO-CONTELLES ◽  
B. SANCHEZ ◽  
C. POZUELO
Keyword(s):  
Building Blocks ◽  
Branched Chain

Synthesis of branched chain cyclitols: preparation of some useful chiral building blocks

1992 ◽  
Vol 3 (6) ◽  
pp. 689-692 ◽  
Author(s):  
José Marco-Contelles ◽  
Belén Sánchez ◽  
Carmen Pozuelo
Keyword(s):  
Building Blocks ◽  
Branched Chain

scholarly journals Chemical and Biochemical Approaches for the Synthesis of Substituted Dihydroxybutanones and Di-, and Tri-Hydroxypentanones

2019 ◽  
Author(s):  
Mikael Widersten ◽  
Derar Al-Smadi ◽  
Thilak Reddy Enugala ◽  
Vadim Kessler ◽  
Anil Ranu Mhashal ◽  
...  
Keyword(s):  
Natural Products ◽  
Aldol Reaction ◽  
Cross Coupling ◽  
Building Blocks ◽  
The Third ◽  
Direct Aldol Reaction ◽  
Metal Organic ◽  
Organic Catalysts

<div>Polyhydroxylated compounds are building blocks for the synthesis of carbohydrates and other natural products. Their synthesis is mainly achieved by different synthetic versions of aldolcoupling reactions, catalyzed either by organocatalysts, enzymes or metal-organic catalysts. We have investigated the formation of 1,4-substituted 2,3-dihydroxybutan-1-one derivatives from para- and meta-substituted phenylacetaldehydes by three distinctly different strategies. The first involved a direct aldol reaction with hydroxyacetone, dihydroxyacetone or 2-hydroxyacetophenone, catalyzed by the cinchona derivative cinchonine. The second was reductive cross-coupling with methyl or phenyl glyoxal promoted by SmI2 resulting in either 5-substituted 3,4-dihydroxypentan-2-ones or 1,4 bis-phenyl substituted butanones, respectively.</div><div>Finally, in the third case, aldolase catalysis was employed for synthesis of the corresponding 1,3,4-trihydroxylated pentan-2-one derivatives. The organocatalytic route with cinchonine generated distereomerically enriched syn products (de = 60−99 %), with moderate enantiomeric excesses (ee = 43−56%), but did not produce aldols with either hydroxyacetone or dihydroxyacetone as donor ketones. The SmI2-promoted reductive cross-coupling generated product mixtures with diastereomeric and enantiomeric ratios close to unity. This route allowed for the production of both 1-methyl- and 1-phenylsubstituted 2,3-dihydroxybutanones, at yields between 40−60%. Finally, the biocatalytic approach resulted in enantiopure syn (3R,4S) 1,3,4-trihydroxypentan-2-ones.</div>

The Oxford Handbook of Inflection

2015 ◽  
Keyword(s):  
Final Section ◽  
Characteristic Property ◽  
Building Blocks ◽  
The Third ◽  
The Pacific ◽  
Word Forms ◽  
Practical Standpoint ◽  
Important Object ◽  
Paradigmatic Structure ◽  
High Degree

Inflection is the expression of grammatical information through changes in word forms. This confrontation between general principles of syntactic organization and the often idiosyncratic properties of words has brought about systems whose properties—among them an often high degree of complexity—are an important object of investigation in their own right. Because it is something that many languages happily do without, inflection has a curious and often contentious status within linguistics. But even so, there is a fascinating and well-delimited set of facts out there to be explored, for which this handbook will be a guide. The volume is made up of twenty-four chapters, which together take a theoretically ecumenical approach, with particular attention paid to draw the examples from a wide variety of languages. The first section covers the fundamental building blocks of inflectional form and content: morphemes, features, and means of exponence. The second section focuses on what is probably the most characteristic property of inflectional systems, paradigmatic structure, and the non-trivial nature of the mapping between function and form. The third section covers change and variation over time, and the fourth section covers computational issues from a theoretical and practical standpoint. Section five addresses psycholinguistic questions. The final section is devoted to sketches of individual inflectional systems, illustrating a range of typological possibilities across a genetically diverse set of languages from Africa, Asia and the Pacific, Australia, Europe, and South America.

Gas Chromatography of Unsaponifiable Matter. III. Identification of Hydrocarbons, Aliphatic Alcohols, Tocopherols, Triterpenoid Alcohols, and Sterols Present in Olive Oils

1965 ◽  
Vol 48 (2) ◽  
pp. 417-433 ◽  
Author(s):  
Jerome Eisner ◽  
John L Iverson ◽  
Alfred K Mozingo ◽  
David Firestone
Keyword(s):  
Gas Chromatography ◽  
Unsaponifiable Matter ◽  
Homologous Series ◽  
Aliphatic Alcohols ◽  
The Third ◽  
Kernel Oil ◽  
Olive Oils ◽  
Olive Kernel ◽  
Branched Chain ◽  
Major Hydrocarbon

Abstract Olive oils, both foreign and domestic, were saponified, and the unsaponifiable matter was fractionated on a Florisil column. Gas chromatography of the first two hydrocarbon fractions confirmed that squalene was the major component of pressed and solvent-extracted pomace oils. However, iso-and/or anteiso- tctratriacontane was the major hydrocarbon in olive kernel oil. Hydrogenation and temperature programming indicated that there were several homologous series present, consisting of normal, iso-and/or anteiso-, and multiple branched chain hydrocarbons. Gas chromatography of the third Florisil fraction (tocopherols, high molecular weight aliphatic alcohols, and triterpenoid alcohol components) indicated the presence of three homologous series of normal, iso- and/or anteiso-, and multiple branched chain alcohols. The triterpenoid alcohols were used to distinguish between pressed and solvent-extracted pomace oils. As little as 5% of pomace oil could be detected in laboratory-prepared mixtures. Campesterol and beta-sitosterol were the two sterols present in olive oils. The Fitelson test detected olive oils consisting entirely or largely of pomace oils.

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