bluuebunny/crossref_metadata_2025 huggingface dataset:
The E.S.R. g2-tensors in CuSO4,5H2O
Authors: Figgis BN , Leckie R
Published: September 2010

The angular variation of
the e.s.r. g-value
of single crystals of CuSO4,5H2O has been measured in a number
of crystal planes. With the assumption that the resonances for each of two
independent tensors are symmetrically broadened, the data have been analysed to
obtain all the elements of these two tensors. The low value of X (1.27)
obtained for the fit to the data indicates that the values obtained for the
elements are of worthwhile accuracy. The orientations of the axes of the
tensorsin relationship to the Cu-O
bond vectors confirm assumptions made in previous treatments. The largest axis
of each tensor lies close to one of the Cu-O(SO3) bond directions.
Synthesis of ω-amino acid peptides related to leucine-enkephalin
Authors: Stewart FHC
Published: September 2010

Syntheses are described of
four peptides with modified leucine-enkephalin sequences in which the native
glycylglycyl segment is replaced by an ω-amino acid residue. o-Nitrophenylthio-ω-amino acids
were used as intermediates, and it was found that the derivatives of
4-aminobutyric and 5-amino-valeric acids undergo facile intramolecular
cyclization under the influence of N,N'-dicyclohexylcarbodiimide.
Facile one-pot synthesis of an insecticide intermediate
Authors: Johnson WMP , Holan G
Published: September 2010

A new insecticide,
3-phenoxybenzyl 2,2-dichloro-1-(2,2-dichlorovinyl)cyclopropane-1-carboxylate
(7), has been synthesized in two steps from a readily available acrylate (2).
The first step conveniently accomplished four distinct chemical transformations
in one pot.
Synthesis, resolution and spectral properties of the cobalt(III) complex of the hexadentate ligand 2,2',2'-[(cyclohexane-1,3,5-triyl)trithio]tris(ethanamine)
Authors: Gahan LR , Sargeson AM
Published: September 2010

The synthesis of a potentially hexadentate ligand 2,2',2''-[(cyclohexane-l,3,5-triyl)trithio]tris(ethanamine) (atch) is described. The ligand forms a hexadentate
cobalt(III) complex which has been resolved into its catoptric
forms. The (+)520-[Co(atch)]3+ complex
displays a strikingly large dichroism in the region
of the first ligand field transition in the circular dichroism
spectrum with Δε480+ 11.9 mol-1 1. cm-1
and has been assigned the Λ absolute
configuration by comparisons of the circular dichroism
with those of similar complexes of known absolute configuration. Attempts to
cap the complex by using nitromethane and
formaldehyde under basic conditions are described.
Equilibrium and dynamics of the binding of calcium ion to sorbitol (D-glucitol)
Authors: Beattie JK , Kelso MT
Published: September 2010

Carbon-13 n.m.r, spectra
have been used to estimate the equilibrium constant and ultrasonic relaxation
methods used to observe the rate of calcium binding to sorbitol
(D-glucitol). The interaction is weak, with
equilibrium constants in D2O of approximately 0.61. mol-1
at 36�C and 1.21. mol-1 at 4�C. The concentration dependence of the
relaxation time is consequently small and the formation rate constant only
approximately determined at 40�C as (1-2) × 108 1, mol-1
s-1. The magnitude of the 13C chemical shifts on binding
calcium ion suggests that coordination may not occur at the hydroxy groups of
carbons C2,C3 and C4 as previously observed with lanthanide ions. The site of
lanthanide binding was confirmed in this work by gadolinium ion broadening of
the 13C n.m.r. resonances.
Malabaricane triterpenes from a Great Barrier Reef collection of the sponge Jaspis stellifera
Authors: Ravi BN , Wells RJ
Published: September 2010

Four new malabaricane triterpenes, related
to malabaricane triterpenes
obtained from a Fijian collection of the sponge Jaspis stellifera, have been isolated from a
Great Barrier Reef collection of J. stellifera. The compounds have been identified, by a combination
of spectral evidence and chemical degradations, as (13Z,15E,17E,22E)-3β-hydroxy-12-oxomalabarica-l3,15,17,22,24-pentaen-
28-oic acid (4), (13Z,15E,17E,22E)-3β-acetoxy-12-oxomalabarica-l3,15,17,22,24-pentaen-28-oic acid (5), (13Z,15E,17E)-3β,28-diacetoxy-22-hydroxymalabarica-13,15,17,24-tetraen-12-one
(6) and (13Z)-15E,17E,22E)-3β-hydroxymalabarica-l3,15,17,22,24-pentaen-12-one
(7).
The phase equilibrium diagram of the ternary system strontium iodide-iodine-water
Authors: Thomas R
Published: September 2010

The phase equilibrium
diagram of the ternary system SrI2-I2-H2O has
shown a single polyiodide SrI12,7H2O
and the hydrate SrI2,7H2O to be stable solid phases at 0�C.
Synthesis of deuterated ent-beyeranes. Stereospecific reduction of a 4-axial aldehyde
Authors: Capon RJ , Ghisalberti EL , Jefferies PR
Published: September 2010

Reduction of the 4a-axial
aldehyde group in ent-3,19-dioxobeyer-15-en-17-oic
acid (1) by sodium borohydride is shown to occur by attack on the Si-face of the carbonyl group. The
synthesis of some ent-beyerane
derivatives stereospecifically labelled with deuterium at C19 is described.
The mechanism of the Mitsunobu reaction. A 31P N.M.R. study
Authors: Guthrie RD , Jenkins ID
Published: September 2010

31P n.m.r. studies indicate that in the Mitsunobu
reaction, alcohols react with diethyl azodicarboxylate and triphenylphosphine
in tetrahydrofuran to produce phosphorane intermediates. Diethyl
azodicarboxylate and tributylphosphine, however, result in the formation of
oxyphosphonium salt intermediates.
The preparation, characterization and solution chemistry of some nickel(II) and copper(II) complexes of 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane
Authors: Coates JH , Hadi DA , Lincoln SF
Published: September 2010

The preparation of the new
ligand 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane, (-N(Me)-(CH2)2-)4
(= L), and the complexes [NiL] (ClO4)2,
[NiL(OCHNMe2)] (ClO4)2,
[NiLN3] ClO4, [CuL] (ClO4)2,
and [NiY] (ClO4)2, where Y =
(-N(Me)(CH2)2N(Me)(CH2)3-)2,
1,4,8,11-tetra-methyl-1,4,8,11-tetraazacyclotetradecane, are described. The
magnetic moments of the nickel((11) species are reported, and the labile
low-spin/high spin equilibria characterizing the
[NiLI2+ and [NiY]2+ systems
over a range of temperatures and ionic strengths in aqueous solution are
discussed. The spectrophotometric titration of the aqua ligands in [NiLH2O]2+,
[CuLH2O]2+, and [NiYH2O]2+ against
sodium hydroxide yields pKa values of 10.2
� 0.2, 12.0 � 0.3 and 10.7 � 0.2, respectively, and a study, using Job's method
of continuous variations, of the formation of azide
species shows [NiLN3]+ and [NiYN3]+
to be formed predominantly in aqueous solution.
The conversion of some carbohydrate diols into cyclic carbonates and thiocarbonates by means of N-dichloromethylene-N,N-dimethylammonium chloride (Viehe's salt)
Authors: Copeland C , Stick RV
Published: September 2010

Various carbohydrate cis and trans vicinal diols have been treated with N-dichloromethylene-N,N- dimethylammonium chloride (Viehe's
salt), and the resulting cyclic salts quenched with water or sodium hydrogen
sulfide to form, in the main, cyclic carbonates and thiocarbonates.
These results are discussed in light of the 'orbital-assist' proposal by
Deslongchamps.
The reactions of the sulfate radical ion with phenylacetic and 4-phenylbutanoic acids
Authors: McAskill NA
Published: September 2010

The
reactions of the sulfate radical ion (SO4-) were studied
by pulse radiolysis of aqueous solutions of aromatic acid and peroxydisulfate ions. With phenylacetic
acid, the major reaction is decarboxylation;
the
resulting ultra-violet absorption spectrum shows that the main product is the
benzyl radical, Ph-·CH2, and that only minor amounts of
hydroxylation products are formed. However, decarboxylation
is unimportant with 4-phenylbutanoic acid and the spectrum has been assigned to
the benzylic Ph-·CH-CH2-CH2-COO-
radical ion. The same spectrum is obtained if the hydrogen abstraction reaction
of the O-· radical ion is used with 4-phenylbutanoic acid to form the
latter radical.
Photoelectrochemical cells with n-CdTe
Authors: Rakhshani AE , Lyons LE
Published: September 2010

The opto-electrical
behaviour of single crystal n-type CdTe in aqueous
solutions containing several redox couples Sn2+,4+, Fe2+3+
and Fe(CN)63-,4-in the dark and under irradiation is
described. The minority carrier diffusion length was 0.13 μm
from a combination of results on photocurrents and capacitance. The dopant concentration was 1.4 × 1017 cm-3
from Mott-Schottky plots. In the cdTe-Sn2+,4+
system the photovoltaic properties of the junction depended on the state of
charge injection into the interface region. We distinguished between a 'high
state' and a 'low state' where in the 'high state' both the open circuit photovoltage and the fill factor were approximately twice
as large as in the 'low state'. Possibilities for a difference in the value of
the built-in potential obtained from the photocurrent method and from a Mott-Schottky plot are described. The built-in potential (or the
flat-band potential) was independent of the redox potential, an effect which is
analogous to Fermi-level pinning. The empirical relationship between barrier height
and band gap in a Fermi-level pinned junction held for our system.
Dipole moments, Kerr constants and solution-state conformations of 1- and 2-pivaloylnaphthalene
Authors: Mirarchi D , Ritchie GLD
Published: September 2010

Infinite-dilution dipole
moments (1030p/Cm) and molar Kerr constants (1027mK/m5
V-2 mol-1) for 1-pivaloylnaphthalene (8.83,-490) and
2-pivaloylnaphthalene (9.24, 218) as solutes in carbon tetrachloride at 25�C
are reported and analysed to yield the dihedral angles between the Car-CO-C
and naphthyl planes as 90 � 10� and 53 � 8�,
respectively.
The reactions of [F----HOMe] and [MeCO2----HF] negative ions with acetaldehyde and acetone. An Ion Cyclotron Resonance and ab initio Study
Authors: Sheldon JC , Bowie JH
Published: September 2010

The ion [F-- - -HOMe] may be produced by the reaction of CF3O-
with methyl formate, a reaction of a type widely used
for the production of 'solvated' negative ions. The possible reaction mechanism
for the model system F-/HCO2H has been explored by ab initio
calculations. The reactions of acetaldehyde and acetone with [F-- -
-HOMe] yield stable [M + F-] ions which are
thought to correspond to 'solvated' enolate negative ions. Their formation in
terms of a mechanistic pathway, recently proposed to account for the formation
of [M + RO-] ions from [RO-- - -HOR]/ > CH-CO- systems, is
supported by ab initio
calculations.
The mechanism of the Mitsunobu reaction. II. Dialkoxytriphenylphosphoranes
Authors: von Itzstein M , Jenkins ID
Published: September 2010

31P n.m.r. studies indicate that, in the Mitsunobu
reaction, alcohols (ROH) react with triphenyl- phosphine (Ph3P) and
dialkyl azodicarboxylates to produce phosphoranes of the type Ph3P(OR)2.
Mixtures of alcohols produce, in addition, mixed phosphoranes, Ph3P(OR)(OR').
Phosphoranes of the type Ph3P(OR)N(CO2R?)NHCO2R'
are probably intermediates in these reactions but are not observed by 31P
n.m.r.
Unfused heterobicycles as amplifiers of phleomycin. VII. Some triazolyl-, thiadiazolyl- and oxadiazolyl-pyridines and related pyrimidines
Authors: Brown DJ , Cowden WB
Published: September 2010

Syntheses are described for
several 4-(1',2',4'-triazol-3'yl)pyridines,
3-and 4-(1',3',4'-thiadiazol-2'-yl)-pyridines,
3- and 4-(1',3',4'-oxadiazol-2'-yl)pyridines, 5-(1',3',4'-thiadiazol-2'-yl)pyrimidines
and 5-(1',3',4'-oxadiazol-2'-yl)pyrimidines,
all provided
with a β-dimethylaminoethylthio side chain at the
5-position of the five-membered ring. The activities of these compounds as
amplifiers of phleomycin-G against an in vitro culture of Escherichia coli B are tabulated and discussed.
Nitrones and oxaziridines. XXXI. Synthesis of some bicyclic 1-pyrroline 1-oxides
Authors: Black DSC , Johnstone LM
Published: September 2010

The bicyclic 1-pyrroline
1-oxides (10), (11) and (13) have been prepared by reductive cyclization of the
respective γ-nitro ketones (3),(4) and (6). Reduction of nitro ketone (2a)
gave the unstable nitrone (7), which underwent dimerization
to compound (8). Nitro ketones (2b,c,d) and (5) were also prepared. The
pyrroline (14) was also a product of the reduction of nitro ketone (6) and was
characterized as the enamide (15).
Synthesis of 5-Aryl- 1,4-benzoxazepine and 6-phenyl-2H-1,5-benzoxazocine derivatives
Authors: Bremner JB , Browne EJ , Gunawardana IWK
Published: September 2010

Four
5-aryl-2,3-dihydro-1,4-benzoxazepines (5a-d), with electron-releasing
substituents, were prepared by a Bischler-Napieralski-type reaction of
N-(2-aryloxyethyl)benzamides with phosphorus oxychloride in butanenitrile or
ethanenitrile. Analogous 2,3-dihydro-1,4-benzoxazepines (12a, b), with hydrogen
only or a chlorine substituent in the fused aromatic ring, were prepared by C-N
ring-closure reactions. Cyclization of a dilute solution of
N-[3-(3-methoxyphenoxy)propyl]benzamide (21) with phosphorus oxychloride in
ethanenitrile gave a 40% yield of 9-methoxy-6-phenyl-3,4-dihydro-
2H-1,5-benzoxazocine (22). The seven- and eight-membered cyclic imines were
converted into their methiodide salts (6a-d), (15a,b) and (24). These were
reduced with sodium tetrahydroborate to yield the
5-aryl-4-methyl-2,3,4,5-tetrahydro-1,4-benzoxazepines (7a-d) and (l6a,b), and
the 9-methoxy- 5-methyl-6-phenyl-3,4,5,6-tetrahydro-2H-1,5-benzoxazocine (25).
These products were prepared for use as starting materials in ring-expansion
reactions through the Meisenheimer rearrangement.
Molten potassium pyrosulfate: the reactions of 12 alkali-metal halides
Authors: Mineely PJ , Tariq SA
Published: September 2010

The oxidation-reduction
reactions of 12 alkali-metal halides with molten potassium pyrosulfate were
studied. Chlorides, bromides and iodides of sodium, potassium, rubidium and
caesium were found to be oxidized to produce chlorine, bromine and iodine respectively.
Sulfur dioxide was found to be the main reduction product. The reactions
between chlorides and pyrosulfate were slow and incomplete, whereas reactions
of bromides and iodides were fast and complete. The order of the oxidizability
(reducing power) of the halides by pyrosulfate, the temperatures, and
stoichiometries of the reactions have been determined.
Micellar properties of disodium 4-alkyl 3-sulfonatosuccinates, two-headed anionic surfactants
Authors: Jobe DJ , Reinsborough VC
Published: September 2010

Density, viscosity,
conductance, dye solubility, and carbon-13 n.m.r. studies were performed in aqueous
solution of three disodium 4-alkyl
3-sulfonatosuccinate surfactants at 25.0�C. The CMC values were 0.33 mol dm-3
for the hexyl homologue (dhss),
0.14 mol dm-3 for the octyl homologue(doss), and 0.041 mol dm-3
for the decyl homologue (ddss).
The aggregation numbers determined viscometrically
and conductimetrically were 15 for dhss, 29 for doss, and 50 for ddss.
The volume changes upon micellization were 7.0 cm3
mol-1 for dhss, 8.8 cm-3 mol-1
for doss, and 9.1 cm3 mol-1for ddss.
Binding constants for the dye pada to the micelle and
the fractions of unbound counter-ion were also obtained. The two polar heads
with their carbon linkage were likely in an aqueous environment in the doss
micelles with the micelles themselves being spherical.
Conformational preferences of the benzenedicarbaldehydes: an ab initio molecular-orbital, dipole-moment and Kerr-effect study
Authors: Mirarchi D , Phillips L , Lumbroso H , Ritchie GLD
Published: September 2010

Ab initio molecular orbital theory at the STO-3G level is used
to elucidate the structures and relative abundances of stable conformations of
the three benzenedicarbaldehydes. In addition, new
measurements of the infinite-dilution dipole moments and molar Kerr constants
of these molecules as solutes in dioxan at 25�C are
reported and analysed. The previously recognized inability of the simple group-
additivity model to reliably predict the anisotropy in the polarizability of
benzene-1,4-dicarbaldehyde is shown to be due to a redistribution of the polarizability in the molecular plane.
A novel biphenyl from the lichen Psoroma contortum
Authors: Elix JA , Jayanthi VK , Jones AJ , Lennard CJ
Published: September 2010

The isolation, structural
elucidation and synthesis of 1,1'-(2,2'-dihydroxy-4,4',6,6'-tetramethoxy-5,5'-
dimethylbiphenyl-3,3'-diyl)bisethanone (contortin) (7), an unusual lichen
metabolite probably derived biogenetically by C-C phenolic coupling of two units
of C-methylphloroacetophenone, is reported.
Spectroscopic data on contortin allowed the structure
to be limited to two possibilities, and these were distinguished by total
synthesis.
Heterocyclic amplifiers of phleomycin. IV. Pyrimidinylpurines, phenylpyrimidines and related systems with basic side chains
Authors: Brown DJ , Lan S , Mori K
Published: September 2010

Syntheses of
4,5,6-triamino-2,4'-bipyrimidines and subsequent conversions into
6-amino-2-pyrimidinylpurine-8-thiones, and their S-dimethylaminoethyl
derivatives, are described; routes to a series of cyclohexyl- and
piperidino-pyrimidines bearing a sulfur-linked side chain, as well as to
phenyl- and methyl-pyrimidines bearing two such side chains, are also
described. As amplifiers of phleomycin in a bacterial screen, the above purines
proved poor, the cyclohexyl- and piperidinopyrimidines showed medium activities,
and the phenylpyrimidines with two side chains (but not the analogous
methylpyrimidines) exhibited very high activities.
The Barrier to Rotation in 9,10-Bis(2,3-dimethylphenyl)phenanthrene: Conformational Interconversion Observed at High Temperatures by Means of Gas Chromatography
Authors: Lai Y , Marriott PJ , Tan B
Published: September 2010

A mixture of the syn and anti conformers of 9,10-bis(2,3- dimethylphenyl ) phenanthrene was prepared. The unexpectedly high energy barrier for the free rotation of the two aryl rings is described. Variable temperature 1H n.m.r . studies failed to provide thermodynamic data for the conformational inter-conversion due to limitations in practicably measurable temperature range. The energies of activation for both interconversion processes were, however, determined by gas chromatographic studies in the temperature range of 225-300°C.
Polyphenol Interactions with Aluminium(III) and Iron(III): their Possible Involvement int he Podzolization Process
Authors: Kennedy JA , Powell HKJ
Published: September 2010

The stability and solubility of complexes formed between AlIII , FeIII and an epicatechin dimer (B2) and an epicatechin polymer or tannin (T) have been studied. Polyphenols such as these could be active in mobilizing iron and aluminium in organic soils; they have the potential to act as bis-catecholate ligands toward these metal ions at neutral pH. However, it is established that the dimer functions only as a mono- catecholate , and its pH dependent stability constants (for aluminium) are no greater than those of catechol . Aqueous solutions of the ligands do not solubilize amorphous Fe(OH)3 significantly under aerobic conditions and the complexes of T are insoluble except at very low metal (Al, Fe) : donor site ratios. These observations are discussed in relation to the soil-forming process of podzolization.
Some Studies on the Reversibility of the Association Step in SRN 1 Reactions
Authors: Norris RK , Wright TA
Published: September 2010

The association step in SRN1 reactions, in which p- nitrobenzylic radicals are trapped by acinitronate ions or the anions from β- keto esters, is demonstrated to be effectively irreversible under the normal conditions of the SRN1 reaction. The dissociation [i.e. fragmentation of the C(α)-C(β) bond] of C- alkylates [e.g. (2) or (3)] formed from aci - nitronates and p- nitrobenzylic substrates appears to take place in a process involving transfer of two electrons and not through dissociation of radical anions.
The Bromination in Aqueous-Solution of Imidazole Coordinated to Co(NH3)5(3+)
Authors: Blackman AG , Buckingham DA , Clark CR , Kulkarni S
Published: September 2010

Bromination of imidazole coordinated to (NH3)5Co3+ (abbreviated Co) has been studied in aqueous Br- media, I = 0.1, 0.5 mol dm-3, 25.0°C; Co(4,5- Br2ImH)3+ and Co(2,4,5-Br3ImH)3+ result from treatment with Br2(aq). Co(4-BrImH )3+ has also been prepared and characterized. Rate data correspond to reaction of the conjugate base of the imidazole complex, Co(BrxIm)2+ (x = 0, 1, 2), with Br2, with successive bimolecular rate constants 6×109, 3×108 and 3.5×103 mol-1 dm3 s-1. Possible mechanisms are discussed.
The Cross-Reaction Between 1-Methoxycarbonyl-1-Methylethyl and 1-Butoxycarbonyl-1-Methylethyl: Simultaneous Generation of Unlike Radicals From an Unsymmetrical Azo Precursor
Authors: Kelly DP , Serelis AK , Solomon DH , Thompson PE
Published: September 2010

The title radicals (1a) and (1b) were generated simultaneously by thermolysis of the unsymmetrical diazene, butyl methyl azoisobutyrate (2d). In the presence of the radical scavenger 2,2,6,6- tetramethylpiperidin-1-yloxyl (4) the products of the geminate cross-reaction show that 45% of radical pairs react by combination and 55% by disproportionation. The disproportionation reaction shows a slight preference for hydrogen transfer from the butyl ester (lb) to the methyl ester (la) radical. In the absence of scavenger (4), the encounter reactions of the two radicals show a slight preference for the cross-reaction over the two self-reactions which is most likely largely due to the imbalance in radical concentrations caused by the greater reactivity toward addition to olefins of the methyl ester radical.
Metal Template Reactions. XXV. N-Acyl Isatin Precursors for the Synthesis of Malonamido Macrocyclic Metal Complexes
Authors: Black DS , Chaichit N , Gatehouse BM , Moss GI
Published: September 2010

Reaction of sodium isatide with dimethylmalonyl dichloride yielded the oxazinoindole (6) rather than the expected product (4). The glyoxylamide (8), which served as a precursor to the macrocyclic complex (15), was therefore prepared by a sequence involving compounds (9), (10) and (7). Such a route makes use of the reactivity of N-acyl isatins and the protecting capacity of the benzyloxycarbonyl group. The structure of compound (6) was established by X-ray crystallography.
Preparation and Structure of Bis-μ-(Benzene-1,2-Dithiolato)-bis[(benzene-1,2-dithiolato)-technetium( IV)]-Chloroform (1:1)
Authors: Colmanet SF , Mackay MF
Published: September 2010

After reaction of benzene-1,2-dithiol (bdtH2) with ammonium [99Tc] pertechnetate in aqueous alcohol, extraction of the reaction mixture with chloroform yielded wine-red crystals of the title compound, C24H16S8Tc2.CHCl3. The crystal structure of the binuclear complex has been determined by X-ray diffraction. Crystals are triclinic and belong to the space group Pī with a 8.534(1), b 8.842(2), c 11.192(3)Ǻ, α 107.02(2), β 98.13(1), γ 100.60(2)° with Z 1. Refinement on 1524 data measured with Cu Kα radiation converged at R 0.082. The complex has exact Ci point symmetry and pseudo-C2 symmetry. Each technetium atom is coordinated to a trigonal -prismatic array of six sulfur ligand atoms. These arrays are fused through a quadrilateral face defined by the four bridging sulfur atoms of two benzene-1,2- dithiolato ligands to give a Tc2S8 core of D2h pseudo-symmetry. As a Tc - Tc bond [bond length 2.591(3)Ǻ] passes through the mid point of the quadrilateral face, this novel geometry can be described in terms of capped trigonal prisms. The chloroform is disordered.
A Mechanism for Anomalous Ozonolysis
Authors: Everest DJ , Grant PK , Slim GC , Yeo IKL
Published: September 2010

Following the ozonolysis of a series of allylic hydroxy olefins derived from manool (6) we propose a mechanism which accounts for the anomalous ozonolysis products of allylic hydroxyl compounds in nucleophilic and non- nucleophilic solvents. It involves intramolecular participation by the allylic hydroxyl to form a hydroperoxy epoxide rather than the 1,2- nucleophilic migration from carbon to oxygen as proposed in the Criegee rearrangement mechanism.
Tropical Marine Algae. II. The Structure Determination of New Halogenated Monoterpenes From Plocamium hamatum (Rhodophyta, Gigartinales, Plocamiaceae)
Authors: Coll JC , Skelton BW , White AH , Wright AD
Published: September 2010

The structure determinations of new halogenated monoterpenes, isolated from collections of Plocamium hamatum J. Agardh , are reported. One collection of P. hamatum afforded (1R*,2R*,4S*,5R*,1′E)-1,2,4- trichloro-5-(2′-chloroethenyl)-1,5-dimethylcyclohexane (1) whose relative stereochemistry was determined by X-ray crystallography. Extensive use of two-dimensional carbon-hydrogen correlation experiments enabled unambiguous assignments of proton and carbon resonances to be made for this new compound. Complete carbon assignments for the related metabolite mertensene (2) are reported. A second collection of P. hamatum afforded three new halogenated monoterpenes. The relative and absolute stereochemistry of (2S,3E,5S,6S,7S)-1,5,7-tribromo-2,6,8-trichloro-2,6-dimethyloct-3-ene (3) was determined by n.m.r . and X-ray crystallography, while for (3R*,4S*,5E)-4,8-dibromo-3,7-dichloro-3,7-dimethylocta-1,5-diene (4) and (2R*,4S*,5R*,1*E)-4-bromo-2-chloro-5-(2′-chloroethenyl)-5-methyl-1-methylenecyclohexane (5), the structures and relative configurations were determined by n.m.r . spectroscopy.
Structural, Magnetic and Spectral Properties of Iron(II) and Nickel(II) Complexes of N1-(Pyridin-2-yl)-3,5-dimethylpyrazole
Authors: Baker AT , Ferguson NJ , Goodwin HA , Rae AD
Published: September 2010

Iron(II) and nickel(II) complexes of N1-(pyridin-2-yl)-3,5-dimethylpyrazole (L) are described. Salts of [FeL3]2+ undergo a reversible temperature-induced singlet (1A1) ↔ quintet (5T2) transition, both in the solid state and in solution. The singlet- quintet change in acetone solution is characterized by ΔH = 25 � 2 kJ mol-1 and ΔS = 95 � 5 J K-1 mol-1. Mossbauer spectral data for solid [FeL3] [BF4]2 confirm a change in ground state for the metal atom with change in temperature and indicate two low-spin species at low temperatures and two high-spin species at elevated temperatures. The average M-N bond length changes accompanying the spin change have been estimated as 0.19 � from data obtained by determination of the structures of [FeL3][ClO4]2 at 135 K and 294 K and of [NiL3][BF4]2 at 294 K by single-crystal X-ray diffractometry. The crystals were all refined as disordered structures in space group P3c1 with Z = 2. Crystal data: [FeL3] [ClO4]2 at 294 K, a = b 10.489(2), 17.521(5) � ;[FeL3][ClO4]2 at 135 K, a = b 10.355(3), c 17.464(5) � ; [NiL3] [BF4]2 at 294 K, a = b 10.404(3), c 17.618(8) � .
Synthesis, Crystal Structure and Magnetism of a Macrocyclic Binuclear Dicopper(II) Amino Alcohol Complex From a Metal Directed Reaction Involving Formaldehyde and Nitroethane
Authors: Comba P , Lawrance GA , Manning TM , Markiewicz A , Murray KS , Oleary MA , Skelton BW , White AH
Published: September 2010

Condensation of the bis (1,5-diaminopentan-3-ol) dicopper (II) ion with formaldehyde and nitroethane in basic methanol yields the macromonocyclic ligand 3,13-dimethyl-3,13-dinitro-1,5,11,15-tetraazaeicosane-8,18-diol as the dicopper (II) complex. The perchlorate salt of the binuclear complex is very strongly antiferromagnetically coupled, with the magnetic properties measured from 10-300 K identifying a singlet-triplet energy gap of -860 cm-1 and a magnetic moment at room temperature of 0.48 BM. The discrete, binuclear nature of the complex was confirmed by a crystal structure analysis of the nitrite salt, which
crystallizes in the monoclinic space group C2/c, a 14.789(6), b 14.560(6), c 12.759(9)Ǻ, β 99.65(4)°, and consists of the centrosymmetric macrocycle containing two copper ions each coordinated by two secondary nitrogen donors and two (shared) RO- groups, with water and nitrite oxygens occupying axial sites. The macrocycle donors and the copper ions are essentially coplanar. The Cu…Cu distance is 3.031(1)Ǻ, with the Cu-O--Cu angle 103.6(2)°. The nitro (and methyl) groups at extremities of the macrocycle are in anti dispositions.
Macrocycle Formation From Copper(II)Directed Condensation of Linear Tetraamines With Formaldehyde Alone and With Added 2-Aminoethanol
Authors: Lawrance GA , Maeder M , Oleary MA , Skelton BW , White AH
Published: September 2010

Reaction of several tetraaminecopper(II) complexes with paraformaldehyde in acetonitrile or dioxan yields oxatetraazacycloalkanecopper(II) complexes, with a new -NH-CH2-O-CH2-NH-link completing the cyclization. The complexes are stable in aqueous acid for appreciable lengths of time, but eventually decompose, with the precursor tetraaminecopper(II) the major product. In alcohol with aqueous formaldehyde, the products are not detected. However, aqueous formaldehyde reacts with a methanolic solution of the copper(II) complex of 4,7- diazadecane-1,10-diamine in the presence of added 2-aminoethanol to produce the polycyclic polyamino ether complex (3-oxa-1,6,8,12,15-pentaazatricyclo[13.3.1.1.8,12]icosane)copper(II) perchlorate. This complex crystallized in the monoclinic space group C2/c, a 32.777(8), b 9.395(2), c 14.914(6)Ǻ, β 111.97(2)°. The structure identifies three -NH-CH2-NH- links, two as parts of new diazacyclohexane rings, and a single -O-CH2-NH- link, all arising from condensation of the polyamine and/or the amino alcohol with formaldehyde. The copper ion lies in a plane of three nitrogens [Cu-N 1.976(4), 2.012(4) and 2.020(3)Ǻ] and the ether oxygen [Cu-O 2.008(3)Ǻ].
Intramolecular Oxidative Coupling of Aromatic Compounds. III. Monophenolic Substrates
Authors: Krauss AS , Taylor WC
Published: September 2010

The synthesis of (2RS,3SR)-4-(4-hydroxy-3,5-dimethoxyphenyl)-2,3-dimethyl-1-(3,4,5-trimethoxypheny1)butan-1-one (9) is described. Monophenolic oxidative coupling of (9) did not give any useful result. Oxidation of the derived acetoxy compound (18) by chemical and electrochemical methods gave aryltetralin derivatives through aryl-benzyl coupling.
H2-O, a MHC class II-like protein, sets a threshold for B-cell entry into germinal centers
Authors: Draghi Nicole A. , Denzin Lisa K.
Published: September 2010

Upon antigen (Ag) encounter, B cells require T-cell help to enter the germinal center (GC). They obtain this help by presenting Ag-derived peptides on MHC class II (MHCII) for recognition by the T-cell receptor (TCR) of CD4
+
T cells. Peptides are loaded onto MHCII in endosomal compartments in a process catalyzed by the MHCII-like protein H2-M (HLA-DM in humans). This process is modulated by another MHCII-like protein, H2-O (HLA-DO in humans). H2-O is a biochemical inhibitor of peptide loading onto MHCII; however, on the cellular level, it has been shown to have varying effects on Ag presentation. Thus, the function of H2-O in the adaptive immune response remains unclear. Here, we examine the effect of H2-O expression on the ability of Ag-specific B cells to enter the GC. We show that when Ag specific WT and H2-O
−/−
B cells are placed in direct competition, H2-O
−/−
B cells preferentially populate the GC. This advantage is confined to Ag-specific B cells and is due to their superior ability to obtain Ag-specific T-cell help when T-cell help is limiting. Overall, our work shows that H2-O expression reduces the ability of B cells to gain T-cell help and participate in the GC reaction.
Vocal cues to male androgen levels in giant pandas
Authors: Charlton Benjamin D. , Keating Jennifer L. , Kersey David , Rengui Li , Huang Yan , Swaisgood Ronald R.
Published: September 2010

Little is known about the potential of non-human mammal vocalizations to signal information on the hormonal status of the caller. In the current study, we used endocrine data and acoustic analyses to determine whether male giant panda bleats provide reliable information about the caller's current androgen levels. Our results revealed significant relationships between acoustic features of male giant panda bleats and the caller's faecal androgen metabolite concentrations. To our knowledge, this constitutes the first demonstration that the acoustic structure of a non-human mammal call has the potential to yield information about the caller's current androgen levels. We go on to discuss the anatomical basis for our findings and the potential functional relevance of signalling information on male androgen levels in giant panda sexual communication.
A genetic screen identifies the Triple T complex required for DNA damage signaling and ATM and ATR stability
Authors: Hurov Kristen E. , Cotta-Ramusino Cecilia , Elledge Stephen J.
Published: September 2010

In response to DNA damage, cells activate a complex signal transduction network called the DNA damage response (DDR). To enhance our current understanding of the DDR network, we performed a genome-wide RNAi screen to identify genes required for resistance to ionizing radiation (IR). Along with a number of known DDR genes, we discovered a large set of novel genes whose depletion leads to cellular sensitivity to IR. Here we describe TTI1 (Tel two-interacting protein 1) and TTI2 as highly conserved regulators of the DDR in mammals. TTI1 and TTI2 protect cells from spontaneous DNA damage, and are required for the establishment of the intra-S and G2/M checkpoints. TTI1 and TTI2 exist in multiple complexes, including a 2-MDa complex with TEL2 (telomere maintenance 2), called the Triple T complex, and phosphoinositide-3-kinase-related protein kinases (PIKKs) such as ataxia telangiectasia-mutated (ATM). The components of the TTT complex are mutually dependent on each other, and act as critical regulators of PIKK abundance and checkpoint signaling.
Classic and contemporary approaches to modeling biochemical reactions
Authors: Chen William W. , Niepel Mario , Sorger Peter K.
Published: September 2010

Recent interest in modeling biochemical networks raises questions about the relationship between often complex mathematical models and familiar arithmetic concepts from classical enzymology, and also about connections between modeling and experimental data. This review addresses both topics by familiarizing readers with key concepts (and terminology) in the construction, validation, and application of deterministic biochemical models, with particular emphasis on a simple enzyme-catalyzed reaction. Networks of coupled ordinary differential equations (ODEs) are the natural language for describing enzyme kinetics in a mass action approximation. We illustrate this point by showing how the familiar Briggs-Haldane formulation of Michaelis-Menten kinetics derives from the outer (or quasi-steady-state) solution of a dynamical system of ODEs describing a simple reaction under special conditions. We discuss how parameters in the Michaelis-Menten approximation and in the underlying ODE network can be estimated from experimental data, with a special emphasis on the origins of uncertainty. Finally, we extrapolate from a simple reaction to complex models of multiprotein biochemical networks. The concepts described in this review, hitherto of interest primarily to practitioners, are likely to become important for a much broader community of cellular and molecular biologists attempting to understand the promise and challenges of “systems biology” as applied to biochemical mechanisms.
The cytoplasmic fate of an mRNP is determined cotranscriptionally: exception or rule?: Figure 1.
Authors: Trcek Tatjana , Singer Robert H.
Published: September 2010

She2p is an RNA-binding protein that recognizes a zipcode on specific mRNAs necessary for the assembly of a protein complex that localizes them to the yeast bud tip. In this issue of Genes & Development, Shen and colleagues (pp. 1914–1926) demonstrate that She2p associates with RNAPII globally, but then recognizes the nascent chain only if it contains a zipcode. This demonstrates yet another case where the mRNA's cytoplasmic fate is determined by the RNAPII complex.
In vitroexposure of human fibroblasts to local anaesthetics impairs cell growth
Authors: Fedder C , Beck-Schimmer B , Aguirre J , Hasler M , Roth-Z'graggen B , Urner M , Kalberer S , Schlicker A , Votta-Velis G , Bonvini J M , Graetz K , Borgeat A
Published: September 2010

Lidocaine, bupivacaine or ropivacaine are used routinely to manage perioperative pain. Sparse data exist evaluating the effects of local anaesthetics (LA) on fibroblasts, which are involved actively in wound healing. Therefore, we investigated the effects of the three LA to assess the survival, viability and proliferation rate of fibroblasts. Human fibroblasts were exposed to 0·3 mg/ml and 0·6 mg/ml of each LA for 2 days, followed by incubation with normal medium for another 1, 4 or 7 days (group 1). Alternatively, cells were incubated permanently with LA for 3, 6 or 9 days (group 2). Live cell count was assessed using trypan blue staining. Viability was measured by the tetrazolium bromide assay. Proliferation tests were performed with the help of the colorimetric bromodeoxyuridine assay. Production of reactive oxygen species (ROS) was determined, measuring the oxidation of non-fluorescent-2,7′-dichlorofluorescin. Treatment of cells with the three LA showed a concentration-dependent decrease of live cells, mitochondrial activity and proliferation rate. Group arrangement played a significant role for cell count and proliferation, while exposure time influenced viability. Among the analysed LA, bupivacaine showed the most severe cytotoxic effects. Increased production of ROS correlated with decreased viability of fibroblasts in lidocaine- and bupivacaine-exposed cells, but not upon stimulation with ropivacaine. This study shows a concentration-dependent cytotoxic effect of lidocaine, bupivacaine and ropivacaine on fibroblasts in vitro, with more pronounced effects after continuous incubation. A possible mechanism of cell impairment could be triggered by production of ROS upon stimulation with lidocaine and bupivacaine.
Historical dynamics of a native cerambycid,Enaphalodes rufulus, in relation to climate in the Ozark and Ouachita Mountains of Arkansas
Authors: HAAVIK LAUREL J. , STEPHEN FREDERICK M.
Published: September 2010

1. Tree‐ring techniques were used to date larval gallery scars of a native wood borer,Enaphalodes rufulus(Haldeman), in hostQuercus rubraL. from eight sites within the Ozark and Ouachita National Forests of Arkansas.

2. Borer densities were quantified throughout the past century as indicated by scars within host tree boles and per capita rate of increase was calculated from one generation to the next. Both of these variables were extrapolated to the regional level.

3. Scar data from 78Q. rubrarevealed that at the regional level borer population growth increased from 1976 to 2000, or 11 generations prior to a recent outbreak. Duration and intensity of eruptive behaviour were variable geographically.

4. Sites with higher outbreak densities also sustained incipient (i.e. growing) populations for a longer time period than sites with lower outbreak densities, which indicates that a greater potential for exponential increase existed at these sites because more borers were present when conditions became favourable for an outbreak.

5. An index of summer soil moisture availability explained almost half of the variation inE. rufuluspopulation growth, which suggests that drought may have been an important causal factor in the recent outbreak.
Management of menorrhagia in women with inherited bleeding disorders: general principles and use of desmopressin
Authors: RODEGHIERO F.
Published: September 2010

Summary.  The haemostatic system has a central role in controlling the amount and the duration of menstrual bleeding, thus abnormally prolonged or profuse bleeding does occur in most women affected by inherited bleeding disorders. Whereas irregular, premenarchal or postmenopausal uterine bleeding is unusual in inherited or acquired heamorrhagic disorders, severe acute bleeding and menorrhagia at menarche and chronic menorrhagia during the entire reproductive life are common manifestations. Prevalence and morbidity of menorrhagia in inherited bleeding disorders have been poorly investigated. It can be estimated that 40% to 60% of currently menstruating women with type 1 or 2 and more than 60% of women with type 3 VWD complain of menorrhagia with a significant impact on their quality of life. Menorrhagia may be particularly distressing in adolescents because of their delicate emotional equilibrium. Similar epidermiology has been described in other inherited disorders like factor XI deficiency, platelet functional defects and in carriers of haemophilia A and B. Women presenting with ‘‘isolated’’ menorrhagia, that is without significant additional bleeding symptoms, a situation reported by up to 15% of healthy women, do not demand investigation to exclude an occult bleeding disorder.

A multidisciplinary approach is required for diagnosis and treatment. Gynaecological supervision is always required to exclude organic causes unmasked by the bleeding disorder. Treatment options are similar to those for menorrhagia in general with the addition of desmopressin and replacement therapy and the exclusion of non‐steroidal anti‐inflammatory drugs. The therapeutic plan should take into consideration the patient's preferences, age and severity of bleeding. Iron supplementation is of paramount importance. Remedies used in clinical practice for menorrhagia in general (tranexamic acid, combined oral contraceptives [COC], levonorgestrel intrauterine system [LNG‐IUS]) are first tried. In case of failure or contraIindication (COC and LNG‐IUS are best avoided in adolescents), before considering surgical options, treatment with desmopressin becomes the preferred choice in patients known to be responsive. The availability of desmopressin preparations for self‐administration makes home treatment feasible in well selected cases. The treatment is efficacious and safe provided that patients are instructed to self‐administer the agent only during the first two or three more heavy days of menstrual period, for a maximum of three to four doses and no more than two consecutive administrations at a 12‐h interval.
Beitrag zur Erweiterung experimenteller Untersuchungs‐methoden beim Schwein
Authors: Hill H. , Prinz W. , Cloos E.
Published: September 2010

Es werden neuere eigene Methoden zur Gewinnung von Harn, peripherem und Pfortaderblut sowie von Darminhalt zur Prüfung von Fragen der Verdauung, der Resorption und des Stoffwechsels beim Schwein beschrieben.

Contribution to perfecting experimental methods in the pig

Original methods are described and illustrated for collecting urine, peripheral and portal blood, and intestinal contents for a study of digestion, absorption and metabolism in the pig.

Contribution au perfectionnement des méthodes expérimentales d'examen chez le porc

Les auteurs décrivent des méthodes personnelles nouvelles permettant de recueillir l'urine, le sang de la veine porte périphérique ainsi que le contenu intestinal pour étudier certains problèmes de la disgestion, de la résorption et du métabolisme chez le porc.

Contribución al estudio de la técnica de análisis clínico experimental en el cerdo

Se describen nuevas técnicas originales para la obtención de orina, sangre periférica de la vena porta, así como de contenido intestinal para estudiar problemas digestivos, de la reabsorción y del metabolismo del cerdo.
Zur Anatomie der Lunge des Sumpfbibers (Myocastor s. Myopotamus coypus)
Authors: Koch Tankred
Published: September 2010

Nach der Beschreibung der Pleurahöhlen, der Trachea und des Bronchalbaums, der Lungenlappung und der Topographie des Mediastinum werden die für den Sumpfbiber charakteristischen Merkmale besonders zusammengefaßt. Diese sind: Weit kranial verschobene Lage des Herzens und Aortenbogens, hingegen verhältnismäßig starke Kaudalverlagerung der Bifurkation und damit der gesamten Lunge, starke Zwerchfellwölbung und tiefer, aber schimaler Sinus phrenicocostalis. Daraus ergibt sich, daß die gegenseitige Beeinflussung des Kreislauf‐ und Respirationssystems bei diesem Tier auf ein Minimum herabgesetzt ist, was offenbar mit dem ethologisch bedingten Tauchien in funktionellem Zusammenhang stent.

The anatomy of the lung of the beaver (Myocastor s. Myopotamus coypus)

After describing the pleural cavities, trachea and bronchial tree, lung lobes, and the topography of the mediastinum, the author deals with the features which are characteristic of this species. These are: the extremely cranial situation of the heart and aortic arch, whereas the bifurcation of the bronchi and the lungs occupy a markedly caudal situation; the marked convexity of the diaphragm and a deep but narrow phrenicocostal sinus. These features indicate that the reciprocal effects of the circulatory and respiratory systems are reduced to a minimum, a fact which seems to be related functionally to the animal's diving habits.

L'anatomie du poumon chez le myocastor

Après avoir décrit les cavités pleurales, la trachée, les ramifications des branches, les lobes pulmonaires et la topographie du médiastin, l'auteur résume spécialement les particularités observées chez le castor. Ce sont: la position très craniale du coeur et de l'aorte, tandis que la bifurcation des branches, et par suite tout le poumon, se trouvent ainsi déplacés caudalement; une forte convexité du diaphragme et un sinus phrenicocostalis profond mais étroit. Il en résulte que les systèmes circulatoires et respiratoires ont chez cet animal une influence réciproque réduite au minimum, ce qui est semble‐t‐il en rapport fonctionnel avec les plongeons fréquents déterminés par des facteurs éthologiques.

Sobre la anatomía del pulmón del miopótamo

Tras la descripción de las cavidades pleurales, de la tráquea y del árbol bronquial, de la lobulación pulmonar y de la topografía del mediastino, se resumen las características especiales para el miopótamo. Estas son: situación del corazón y del cayado de la aorta muy desplazada en sentido craneal, en cambio se registra un desplazamiento caudal relativamente considerable de la bifurcación y con ello de todo el pulmón; fuerte bóveda diafragmática y seno costofrénico profundo, aunque estrecho. De aquí resulta que la mutua influencia de los sistemas circulatorio y respiratorio en este animal está reducida a un mínimo, lo que evidentemente está en relación funcional con la inmersión etológicamente condicionada.
Development and validation of a photonumeric grading scale for assessing lip volume and thickness
Authors: Rossi AB , Nkengne A , Stamatas G , Bertin C
Published: September 2010

Background  Currently, there is the need of a validated grading scale for assessing lip volume/thickness.

Objective  The aim of this study was to assist clinicians in managing individuals seeking lip rejuvenation and to provide an objective method for evaluating the efficacy and longevity of such treatments.

Methods  Using accepted criteria for the development of dermatological grading scales, we have developed and validated a photographic grading scale for assessing lip volume and thickness based on digital parallel‐polarized light imaging.

Results  The photographic grading scale was shown to be a valid and reliable instrument for assessing lip volume and thickness, with good inter‐ and intra‐grader consistency. The validity of the scale was demonstrated by its correlation with clinical evaluation and 3‐dimensional measurements.

Conclusions  This validated lip‐volume/thickness grading scale should prove helpful in clinical trial settings to standardize clinical evaluations and to quantify results and measure the longevity of dermal fillers and other procedures for lip rejuvenation.
When a Company Becomes a Brand: An Interview with Haworth, Inc.‘s John C. Berrett
Authors: Robbins Bob , McCuen Anne
Published: September 2010

THIS IS A CONVERSATION about durability, flexibility and branding. Haworth produces office and institutional furniture in North America and Europe. As the company has expanded its market through acquisitions, it has developed an identity strategy that absorbs subsidiaries into the Haworth brand. The exchange among John Berrett, Bob Robbins, and Anne McCuen reveals, however, that Haworth applies this approach carefully because, sometimes, there is more to be lost than gained when it comes to implementing a master brand strategy.