bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebral protection during open retrograde angioplasty/stenting of common carotid and innominate artery stenoses
Authors: Payne D A , Hayes P D , Bolia A , Fishwick G , Bell P R F , Naylor A R
Published: January 2006

Background

This was a retrospective study of the effectiveness of open, retrograde angioplasty/stenting of supra-aortic arterial stenoses combined with transcranial Doppler-directed dextran therapy in preventing perioperative embolization.

Methods

Eight patients underwent angioplasty/stenting of the proximal common carotid (synchronous carotid endarterectomy (CEA) in six), while four underwent angioplasty/stenting of the innominate artery (synchronous CEA in one). Open exposure of the carotid bifurcation enabled temporary carotid clamping to protect the brain from procedural embolization. Dextran was administered to patients with a high rate of embolization on transcranial Doppler after the operation.

Results

No emboli were recorded in the cerebral circulation during the actual angioplasty procedure when the internal carotid artery was clamped. After operation three patients developed high-rate embolization and received dextran. No strokes or deaths occurred within 30 days of treatment. One patient developed symptoms and a recurrent stenosis greater than 50 per cent during follow-up and was treated by redo angioplasty.

Conclusion

Retrograde angioplasty/stenting with or without synchronous CEA offers an alternative approach to treating patients with supra-aortic inflow disease.
Differences in the fatty acid composition of KB‐cells and gingival keratinocytes is culture medium additive dependent
Authors: Pelz K , Hopfener K , Wiedmann‐Al‐Ahmad M , Jahnke H , Wittmer A , Otten J‐E
Published: January 2006

The influence of culture medium additives foetal bovine serum (FBS), serum effective substitutes (SES) and human autologous serum on the fatty acid profile of KB‐cells and human gingival keratinocytes was examined. The KB‐cells were cultivated in RPMI medium added with FBS or SES and the gingival keratinocytes in D‐MEM added with FBS or human autologous serum. Two days before the cells were prepared for gas chromatography (GC), the media were changed to serum‐ and antibiotic‐free media. Whole fatty acids of the cells were analysed using GC and the fatty acid profiles were compared. KB‐cells as well as gingival keratinocytes changed their fatty acid composition, according to the medium additive used. Significant differences were observed. In the case of KB‐cells cultivated with SES the fatty acid changes suggest an increase of the membrane fluidity. Corresponding and significant differences were observed with gingival keratinocytes cultivated in medium added with human autologous serum: the membrane fluidity of the gingival keratinocytes was increased. It is supposed that an increased membrane fluidity caused by a different fatty acid spectrum of the host cell may relate to mechanisms of bacterial adhesion. Consequentely, in vitro studies on invasion and adhesion of bacteria or virus are dependent on the medium used. Further analyses are necessary of the functional effects caused by differences in the content of specific FAs, especially with regard to the application of cultivated cells in the field of tissue engineering. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of rosuvastatin in rat plasma by HPLC: validation and its application to pharmacokinetic studies
Authors: Kumar Thammera Ranjith , Shitut Nikhil R. , Kumar Pasikanti Kishore , Vinu Menon C.A. , Kumar Venkata V. Pavan , Mullangi Ramesh , Srinivas Nuggehally R.
Published: January 2006

A specific, accurate, precise and reproducible high‐performance liquid chromatography (HPLC) method was developed for the estimation of rosuvastatin (RST), a novel, synthetic and potent HMG‐CoA inhibitor in rat plasma. The assay procedure involved simple liquid–liquid extraction of RST and internal standard (IS, ketoprofen) from a small plasma volume directly into acetonitrile. The organic layer was separated and evaporated under a gentle stream of nitrogen at 40°C. The residue was reconstituted in the mobile phase and injected onto a Kromasil KR 100‐5C18 column (4.6 × 250 mm, 5 µm). Mobile phase consisting of 0.05 m formic acid and acetonitrile (55:45, v/v) was used at a flow rate of 1.0 mL/min for the effective separation of RST and IS. The detection of the analyte peak was achieved by monitoring the eluate using a UV detector set at 240 nm. The ratio of peak area of analyte to IS was used for quantification of plasma samples. Nominal retention times of RST and IS were 8.6 and 12.5 min, respectively. The standard curve for RST was linear (r2 > 0.999) in the concentration range 0.02–10 µg/mL. Absolute recoveries of RST and IS were 85–110 and >100%, respectively, from rat plasma. The lower limit of quantification (LLOQ) of RST was 0.02 µg/mL. The inter‐ and intra‐day precisions in the measurement of quality control (QC) samples, 0.02, 0.06, 1.6 and 8.0 µg/mL, were in the range 7.24–12.43% relative standard deviation (RSD) and 2.28–10.23% RSD, respectively. Accuracy in the measurement of QC samples was in the range 93.05–112.17% of the spiked nominal values. Both analyte and IS were stable in the battery of stability studies, viz. benchtop, autosampler and freeze–thaw cycles. RST was found to be stable for a period of 30 days on storage at −80°C. The application of the assay to determine the pharmacokinetic disposition after a single oral dose to rats is described. Copyright © 2006 John Wiley & Sons, Ltd.
Quantification of granisetron in human plasma by liquid chromatography coupled to electrospray tandem mass spectrometry
Authors: Nirogi Ramakrishna V. S. , Kandikere Vishwottam N. , Shukla Manoj , Mudigonda Koteshwara , Maurya Santosh , Boosi Ravikumar
Published: January 2006

A simple, sensitive and rapid high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry method was developed and validated for the assay of granisetron in human plasma. Following liquid–liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase C18 column and analyzed by MS in the multiple reaction monitoring mode using the respective [M+H]+ ions, m/z 313/138 for granisetron and m/z 409/228 for the IS. The assay exhibited a linear dynamic range of 0.1–20 ng/mL for granisetron in human plasma. The lower limit of quantification was 100 pg/mL with a relative standard deviation of less than 5%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.0 min for each sample made it possible to analyze more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. Copyright © 2006 John Wiley & Sons, Ltd.
Development and validation of a rapid reversed‐phase HPLC method for the determination of insulin from nanoparticulate systems
Authors: Sarmento Bruno , Ribeiro António , Veiga Francisco , Ferreira Domingos
Published: January 2006

A reversed‐phase high‐performance liquid chromatographic (HPLC) method has been developed and validated for the determination of insulin in nanoparticulate dosage forms. Its application for the development and characterization of insulin‐loaded nanoparticulates composed of polyelectrolytes has also been carried out. A reversed‐phase (RP) C18 column and gradient elution with a mobile phase composed of acetonitrile (ACN) and 0.1% aqueous trifluoroacetic acid (TFA) solution at a flow rate of 1 mL/min was used. Protein identification was made by UV detection at 214 nm. The gradient changed from 30:70 (ACN:TFA, v/v) to 40:60 (v/v) in 5 min followed by isocratic elution at 40:60 (v/v) for a further five minutes. The method was linear in the range of 1–100 µg/mL (R2 = 0.9996), specific with a good inter‐day and intra‐day precision based on relative standard deviation values (less than 3.80%). The recovery was between 98.86 and 100.88% and the detection and quantitation limits were 0.24 and 0.72 µg/mL, respectively. The method was further tested for the determination of the association efficiency of insulin to nanoparticulate carriers composed of alginate and chitosan, as well as its loading capacity for this protein. Encapsulant release under simulated gastrointestinal fluids was evaluated. The method can be used for development and characterization of insulin‐loaded nanoparticles made from cross‐linked chitosan‐alginate. Copyright © 2006 John Wiley & Sons, Ltd.
Determination, purity assessment and chiral separation of levodopa methyl ester in bulk and formulation pharmaceuticals
Authors: Wang Jie , Fang Yuzhi
Published: January 2006

A sensitive, reliable and reproducible HPLC method with electrochemical detection (HPLC‐ECD) has been developed for the separation and quantification of levodopa methyl ester (LDME) and its impurities such as levodopa (l‐DOPA), 3‐methoxytyrosine (MTS) and l‐tyrosine (TS) in bulk drug and pharmaceutical dosage form. The separation was performed on an LC18 column by isocratic elution with methanol–acetonitrile–50 mm potassium dihydrogen phosphate (8:2:90, v/v/v) containing 5 mm sodium 1‐hexanesulfonate, 5 mm EDTA and 5 mm sodium chloride, adjusted with phosphoric acid to a pH of 3.2 as mobile phase. The correlation coefficients of linear regression for LDME, l‐DOPA, MTS and TS were more than 0.999. The detection limits for l‐DOPA, MTS and TS were 3.15, 2.04 and 2.88 ng/mL, respectively. The precision was checked in terms of F‐test variance ratio using potentiometric titration as reference. The separation of dopa methyl ester enantiomers by chiral chromatography is also described. This method is capable of separating the two enantiomers with a selection of 1.4 and a resolution of 8.4. Both methods were found to be stable and useful in the quality control of the bulk material and formulations. Copyright © 2006 John Wiley & Sons, Ltd.
An automated blood sampling system to measure lovastatin level in plasma and faeces
Authors: Wang Shau‐Chun , Ho Li‐Kai , Yen Jiin‐Cherng , Tsai Tung‐Hu
Published: January 2006

The aim of this study was to develop an automated sampling method to measure lovastatin in a conscious and freely moving rat. The blood samples were collected by means of the automated blood sampling system DR‐II and the faecal samples were collected using a metabolic cage. The concentration of lovastatin was determined by a reversed‐phase liquid chromatographic system with a UV absorbance detector. The mobile phase contained acetonitrile and 10 mm NaH2PO4 in the proportions 60:40 (v/v) with a flow‐rate of 1 mL/min. The calibration curve was linear in concentration ranges of 0.05–100 and 0.1–100 µg/mL for lovastatin in blood and faecal samples, respectively. Following pharmacokinetic analysis, we identified that the maximum plasma concentration was around 1.18 ± 0.08 µg/mL at concentration peak time 120 min and almost 78% of loading dose was accumulated in the faeces within 48 h after lovastatin administration (500 mg/kg, p.o.). Copyright © 2006 John Wiley & Sons, Ltd.
The use of hypnosis in the treatment of driving phobia
Authors: Hill Robert , Bannon‐Ryder Glynn
Published: January 2006

The client was a 37‐year‐old married woman with two young daughters working as a community psychiatric nurse who requested assistance with driving difficulties following a number of accidents, and maintained by avoidance behaviour. Assessment indicated that she was currently avoiding driving on any unfamiliar routes and avoiding motorway travel altogether. This avoidance was affecting her professional and personal life and she was keen to see whether the use of hypnotic procedures in conjunction with a behavioural driving programme could help her. Four sessions were undertaken and, although she retained some anxiety, sufficient progress was established for her to make a long distance trip that she has been avoiding for a number of years. Reviewing progress a year later, she reported that residual anxiety had diminished and that progress had continued. Copyright © 2005 British Society of Experimental and Clinical Hypnosis
Continua of Interactions between Pairs of Atoms in Molecular Crystals
Authors: Dominiak Paulina M. , Makal Anna , Mallinson Paul R. , Trzcinska Kinga , Eilmes Julita , Grech Eugeniusz , Chruszcz Maksymilian , Minor Władek , Woźniak Krzysztof
Published: January 2006

The electron density distributions in crystals of five previously studied DMAN complexes and five Schiff bases (two new ones) have been analysed in terms of various properties of bond critical points (BCPs) found in the pair‐wise interactions in their lattices. We analysed the continua of interactions including covalent/ionic bonds as well as hydrogen bonds and all other types of weak interactions for all pairs of interacting atoms. The charge density at BCPs and local kinetic and potential energy densities vary exponentially with internuclear distance (or other measures of separation). The parameters of the dependences appear to be characteristics of particular pairs of atom types. The Laplacian and the total (sum of kinetic and potential) energy density at BCPs show similar behaviour with the dependence being of the Morse type. The componentsλ1,λ2,λ3of the Laplacian at BCPs vary systematically with internuclear distance according to the type of atom pair. Forλ1andλ2the distribution is of the exponential type, whereasλ3does not seem to follow any simple functional form, consistent with previous theoretical findings. Analytical nonlinear dependences of Laplacian on charge density have been found. They agree reasonably well with those obtained by least square fit of the Laplacian to charge density data. There are four distinct regions of the ∇2ρBCP/ρBCPspace, generated byEBCP=0 andGBCP/ρBCP=1 conditions. Two regions clearly correspond to the shared‐shell and closed‐shell interactions and the other two to some intermediate situation.
Co/CNF Catalysts Tailored by Controlling the Deposition of Metal Colloids onto CNFs: Preparation and Catalytic Properties
Authors: Qiu Jieshan , Zhang Hongzhe , Liang Changhai , Li Jiawei , Zhao Zongbin
Published: January 2006

Carbon nanofiber‐supported Co nanocomposites were prepared by means of a modified ethylene glycol (EG) process, in which the Co salts are reduced in EG and are subsequently deposited onto carbon nanofibers (CNFs). It has been found that the deposition of cobalt colloids onto CNFs can be tailored by simply adjusting the pH of the EG and by heating the mixture of CNFs and colloidal solution at 100 °C for some time. The pH value (<7) and the temperature (at least 100 °C) for heating the mixture of CNFs and colloidal solution are found to be the key factors for depositing Co particles onto CNFs. The obtained Co/CNFs have a high and homogeneous dispersion of spherical Co metal particles with a narrow size distribution of 10–15 nm with a peak around 13.5 nm; this result is consistent, to a certain degree, with the value of 12.8 nm obtained from the XRD study. The different states of the stabilizer including carboxylates (pH>7) and carboxylic acids (pH<7) as well as the decomposition of carboxylic acids during heat treatment were monitored by using FTIR and UV‐visible spectroscopy. On the basis of experimental results, the mechanism of depositing cobalt colloids onto CNFs is also addressed. The as‐synthesized Co/CNF catalysts show excellent activity and regioselectivity for the 1‐octene hydroformylation.
Biomolecule‐Assisted Synthesis and Electrochemical Hydrogen Storage of Porous Spongelike Ni3S2 Nanostructures Grown Directly on Nickel Foils
Authors: Zhang Bin , Ye Xingchen , Dai Wei , Hou Weiyi , Xie Yi
Published: January 2006

Nanothread‐based porous spongelike Ni3S2 nanostructures were synthesized directly on Ni foil by using a simple biomolecule‐assisted method. By varying the experimental parameters, other novel Ni3S2 nanostructures could also be fabricated on the nickel substrate. The electrochemical hydrogen‐storage behavior of these novel porous Ni3S2 nanostructures was investigated as an example of the potential properties of such porous materials. The thread‐based porous spongelike Ni3S2 could electrochemically charge and discharge with the high capacity of 380 mAh g−1 (corresponding to 1.4 wt % hydrogen in single‐walled nanotubes (SWNT)). A novel two‐charging‐plateaux phenomenon was observed in the synthesized porous spongelike Ni3S2 nanostructures, suggesting two independent steps in the charging process. We have demonstrated that the morphology of the synthesized Ni3S2 nanostructures had a noticeable influence on their electrochemical hydrogen‐storage capacity. This is probably due to the size and density of the pores as well as the microcosmic morphology of different nickel sulfide nanostructures. These novel porous Ni3S2 nanostructures should find wide applications in hydrogen storage, high‐energy batteries, luminescence, and catalytic fields. This facile, environmentally benign, and solution‐phase biomolecule‐assisted method can be potentially extended to the preparation of other metal sulfide nanostructures on metal substrates, such as Cu, Fe, Sn, and Pb foils.
Phototransformation of Stilbene in van der Waals Nanocapsules
Authors: Ananchenko Gennady S. , Udachin Konstantin A. , Ripmeester John A. , Perrier Thomas , Coleman Anthony W.
Published: January 2006

We have utilized para‐hexanoylcalix[4]arene nanocapsules as hosts to carry out phototransformations of cis‐ and trans‐stilbene. Single‐crystal X‐ray diffraction studies were performed to define precisely the location of encapsulated stilbenes inside the capsule and to analyze possible pathways of phototransformation. cis‐Stilbene stacks as a π–π dimer located at the center of the capsule, whereas trans‐stilbene does not form such a dimer. Irradiation of the crystalline inclusion complexes of each isomer of stilbene in the solid state leads to the appearance of the second isomer, and after prolonged photolysis, photodimerization also occurs. syn‐Tetraphenylcyclobutane is formed as the major product of dimerization and its yield depends on the time and intensity of irradiation. In most cases, the single crystals of the complexes remain intact during irradiation; hence, the nanocapsules have the potential to serve as robust nanoreactors in the solid state. The confinement in the nanocapsules is sufficient to keep the reacting molecules together, although this is less restrictive than for trans‐stilbene crystals, in which the molecules cannot achieve a favorable orientation for dimerization.
Tunable Fluorene‐Based Dynamers through Constitutional Dynamic Chemistry
Authors: Giuseppone Nicolas , Fuks Gad , Lehn Jean‐Marie
Published: January 2006

Dynamic covalent iminofluorene‐based oligomers and polymers have been generated. They undergo constitutional recomposition under the effect of two parameters, acidity and ZnII metal ions. As a result, marked changes in physical properties take place. The results illustrate the response of such a dynamic system to chemical effectors (H+ and ZnII), thus demonstrating the adaptive behavior of the system under the pressure of external factors. They also point to the possibility of modulating optical properties (UV‐visible absorption and fluorescence) by constitutional recomposition in response to a specific trigger. Such features allow the development of dynamic materials, the functional properties of which may respond to external stimuli.
Chemistry of Anthracene–Acetylene Oligomers: Synthesis and Enantiomeric Resolution of a Chiral 1,8‐Anthrylene–Ethynylene Cyclic Tetramer
Authors: Toyota Shinji , Suzuki Shinya , Goichi Michio
Published: January 2006

To construct a new type of chiral π‐conjugated system, the title anthracene–acetylene oligomer containing two octyl groups at position 10 of 1,2‐alternating anthracene groups was synthesized. Each anthracene unit was connected by Sonogashira coupling, and the tetrameric precursor was cyclized by a cross‐coupling reaction to form the desired C2‐symmetric compound. Its enantiomers were resolved by chiral HPLC with a Chiralcel OD column, and the chiroptical properties were investigated by optical rotation ([α]${{{23\hfill \atop {\rm D}\hfill}}}$=−95 and +91) and circular dichroism (CD) measurements. The structural and spectroscopic features of this oligomer were discussed in terms of the molecular symmetry and the dynamic behavior of the macrocyclic framework.
Total Synthesis and NMR Investigations of Cylindramide
Authors: Cramer Nicolai , Buchweitz Maria , Laschat Sabine , Frey Wolfgang , Baro Angelika , Mathieu Daniel , Richter Christian , Schwalbe Harald
Published: January 2006

Cylindramide (1) was built up from three components: a hydroxyornithine derivative 7, a tetrazolylsulfone 8, and a substituted pentalene subunit 9. Derivative 7 was prepared in a six‐step reaction sequence involving the Wittig reaction and a Sharpless asymmetric dihydroxylation starting from N‐Boc‐3‐aminopropanal (12). Tetrazolylsulfone 8 was accessible in four steps from dioxinone 22. The synthesis of the pentalene fragment 9 started from cycloocta‐1,5‐diene 26, that was converted into enantiopure bicyclo[3.3.0]octanedione 29. The latter was functionalized to give derivative 9. The total synthesis was accomplished by inducing CC bond formation by Sonogashira coupling of derivatives 9 and 7 followed by olefination with tetrazolylsulfone 8 under Julia–Kocienski conditions, macrocyclization, and subsequent Lacey–Dieckmann condensation to form the tetramic acid unit. As indicated by extensive 1H and 13C NMR spectroscopic investigations (DQF‐COSY, ROESY spectra), the stereochemistry of synthetic cylindramide (1) corresponds with that of the naturally occurring product. ROE data were used for molecular modeling of the lowest‐energy structures for cylindramide.
Rigidity and gamma convergence for solid‐solid phase transitions with SO(2) invariance
Authors: Conti Sergio , Schweizer Ben
Published: January 2006

The singularly perturbed two‐well problem in the theory of solid‐solid phase transitions takes the formwhereu: Ω ⊂ ℝn→ ℝnis the deformation, andWvanishes for all matrices inK= SO(n)A∪ SO(n)B. We focus on the casen= 2 and derive, by means of Gamma convergence, a sharp‐interface limit forIε. The proof is based on a rigidity estimate for low‐energy functions. Our rigidity argument also gives an optimal two‐well Liouville estimate: if ∇uhas a small BV norm (compared to the diameter of the domain), then, in theL1sense, either the distance of ∇ufrom SO(2)Aor the one from SO(2)Bis controlled by the distance of ∇ufromK. This implies that the oscillation of ∇uin weakL1is controlled by theL1norm of the distance of ∇utoK. © 2006 Wiley Periodicals, Inc.
Decay of correlations and the central limit theorem for meromorphic maps
Authors: Dinh Tien‐Cuong , Sibony Nessim
Published: January 2006

Let f be a dominant meromorphic self‐map of large topological degree on a compact Kähler manifold. We give a new construction of the equilibrium measure μ of f and prove that μ is exponentially mixing. As a consequence, we get the central limit theorem in particular for Hölder‐continuous observables, but also for noncontinuous observables. © 2005 Wiley Periodicals, Inc.
Long‐time dynamics of KdV solitary waves over a variable bottom
Authors: Dejak Steven I. , Sigal Israel Michael
Published: January 2006

We study the variable‐bottom, generalized Korteweg—de Vries (bKdV) equation ∂tu = −∂x(∂u + f(u) − b(t,x)u), where f is a nonlinearity and b is a small, bounded, and slowly varying function related to the varying depth of a channel of water. Many variable‐coefficient KdV‐type equations, including the variable‐coefficient, variable‐bottom KdV equation, can be rescaled into the bKdV. We study the long‐time behavior of solutions with initial conditions close to a stable, b = 0 solitary wave. We prove that for long time intervals, such solutions have the form of the solitary wave whose center and scale evolve according to a certain dynamical law involving the function b(t,x) plus an H1(ℝ)‐small fluctuation. © 2005 Wiley Periodicals, Inc.
Form boundedness of the general second‐order differential Operator
Authors: Maz′ya Vladimir G. , Verbitsky Igor E.
Published: January 2006

We give explicit necessary and sufficient conditions for the boundedness of the general second‐order differential operatorwith real‐ or complex‐valued distributional coefficientsaij,bj, andc, acting from the Sobolev spaceW1, 2(ℝn) to its dualW−1, 2(ℝn). This enables us to obtain analytic criteria for the fundamental notions of relative form boundedness, compactness, and infinitesimal form boundedness of ℒ︁ with respect to the Laplacian onL2(ℝn).

In particular, we establish a complete characterization of the form boundedness of the Schrödinger operator$(i \nabla + \vec{a})^2 + q$with magnetic vector potential$\vec{a} \in L^2_{{\rm loc}} (R^{n})^{n}$andq∈D′(ℝn). © 2005 Wiley Periodicals, Inc.
Study of the Pm$\bar 3$n Space Group of Cubic Mesoporous Silica
Authors: Han Shuhua , Hou Wanguo , Xu Jun , Huang Xirong , Zheng Liqiang
Published: January 2006

By using a Gemini surfactant, [C14H25N+(CH3)2(CH2)2N+(CH3)2C14H25]⋅2 Br−(C14‐2‐14), with a short spacer group (s=2) as structure‐directing agent and sodium silicate as precursor, high‐quality, ordered cubic mesoporous silica with space group Pm$\bar 3$n was prepared by the S+I−route (S=surfactants, I=precursor). The samples were characterized by small‐angle X‐ray diffraction, transmission electron microscopy, and N2 adsorption–desorption. The results showed that the pore structure of the resulting mesoporous silica belonged to the cubic system (space group Pm$\bar 3$n). The unit‐cell parameter of the cubic system was in the range of 8.81–9.14 nm. The high‐quality cubic mesoporous structure was formed at molar ratios of C14‐2‐14to sodium silicate of 0.33:1 to 0.16:1 and a molar ratio of ethyl acetate to sodium silicate of 2:1. N2 adsorption–desorption curves revealed type IV isotherms and H1 hysteresis loops. The primary pore volume, and the most probable pore size according to the Barrett–Joyner–Halenda (BJH) model, increased with increasing molar ratio of C14‐2‐14to sodium silicate.
Asbestos Mineral Analysis by UV Raman and Energy‐Dispersive X‐ray Spectroscopy
Authors: Petry Renate , Mastalerz Remigius , Zahn Stefan , Mayerhöfer Thomas G. , Völksch Günther , Viereck‐Götte Lothar , Kreher‐Hartmann Birgit , Holz Lothar , Lankers Markus , Popp Jürgen
Published: January 2006

The applicability of a UV micro‐Raman setup was assessed for the rapid identification of fibrous asbestos minerals using 257 and 244 nm laser light for excitation. Raman spectra were obtained from six asbestos reference standards belonging to two basic structural groups: the serpentines (chrysotile) and the amphiboles (crocidolite, tremolite, amosite, anthophyllite, and actinolite). The UV Raman spectra reported here for the first time are free from fluorescence, which is especially helpful in assessing the hydroxyl‐stretching vibrations. The spectra exhibit sharp bands characteristic of each asbestos species, which can be used for the unambiguous identification of known and unknown asbestos fibres. Evident changes of the relative band intensities sensitively reflect the chemical substitutions that typically occur in asbestos minerals. The elemental composition of the asbestos reference samples was analysed by using a scanning electron microscope equipped with an energy‐dispersive X‐ray (EDX) spectrometer. The discussion of the experimental results in terms of EDX analysis sheds new light on the structural and vibrational consequences of cation distribution in asbestos minerals.
Synthesis and Photoluminescence of Titania Nanoparticle Arrays Templated by Block‐Copolymer Thin Films
Authors: Sun Zaicheng , Kim Dong Ha , Wolkenhauer Markus , Bumbu Gabriela Gina , Knoll Wolfgang , Gutmann Jochen S.
Published: January 2006

High‐density arrays of titania nanoparticles were prepared using a polystyrene‐b‐poly(ethylene oxide) block copolymer (PS‐b‐PEO) as a template and a titanium tetraisopropoxide based sol–gel precursor as titania source via a spin‐coating method. The hydrophilic titania sol–gel precursor was selectively incorporated into hydrophilic PEO domains of PS‐b‐PEO and form titania nanoparticle arrays, due to a microphase separation between the PS block and the sol–gel/PEO phase. Field emission scanning electron microscopy (FESEM) and scanning probe microscopy (SPM) images showed that the uniformity and long‐range order of the titania/PEO domains improved with increasing sol–gel precursor amount. Grazing incidence small‐angle X‐ray scattering (GISAXS) results indicate that the ordered structures exist over large length scales. Titania nanocrystal arrays of anatase modification were obtained by calcination at 600 °C for 4 h. After calcination, separated particles were observed for low and medium amounts of sol–gel precursors. Films with higher precursor amounts showed wormlike structures due to the aggregation between neighboring particles. Removal of the polymer matrix via UV treatment leads to highly ordered arrays of amorphous titania while retaining the domain size and interparticle distance initially present in the hybrid films. Photoluminescence (PL) properties were investigated for samples before and after calcination. The PL intensity increases with the increasing amount of sol–gel precursor. Bands at 412 nm were ascribed to self‐trapped exitons and bands at 461 and 502 nm to oxygen vacancies, respectively. Uncalcined or UV‐treated samples also showed PL properties similar to calcined samples, indicating that the local environment of the titanium atoms is similar to the environment of the crystalline anatase modification.
The multi‐faceted cross‐talk between the insulin and angiotensin II signaling systems
Authors: Velloso Licio A. , Folli Franco , Perego Lucia , Saad Mario J. A.
Published: January 2006

Insulin and angiotensin II are hormones that play pivotal roles in the control of two vital and closely related systems, the metabolic and the circulatory systems, respectively. A failure in the proper action of each of these hormones results, to a variable degree, in the development of two highly prevalent and commonly overlapping diseases—diabetes mellitus and hypertension. In recent years, a series of studies has revealed a tight connection between the signal transduction pathways that mediate insulin and angiotensin II actions in target tissues. This molecular cross‐talk occurs at multiple levels and plays an important role in phenomena that range from the action of anti‐hypertensive drugs to cardiac hypertrophy and energy acquisition by the heart. At the extracellular level, the angiotensin‐converting enzyme controls angiotensin II synthesis but also interferes with insulin signaling through the proper regulation of angiotensin II and through the accumulation of bradykinin. At an early intracellular level, angiotensin II, acting through JAK‐2/IRS‐1/PI3‐kinase, JNK and ERK, may induce the serine phosphorylation and inhibition of key elements of the insulin‐signaling pathway. Finally, by inducing the expression of the regulatory protein SOCS‐3, angiotensin II may impose a late control on the insulin signal. This review will focus on the main advances obtained in this field and will discuss the implications of this molecular cross‐talk in the common clinical association between diabetes mellitus and hypertension. Copyright © 2006 John Wiley & Sons, Ltd.
Determinants of glycaemic control in type 1 diabetes during intensified therapy with multiple daily insulin injections or continuous subcutaneous insulin infusion: importance of blood glucose variability
Authors: Pickup John C. , Kidd Julia , Burmiston Sheila , Yemane Nardos
Published: January 2006

Background and methods

We investigated the factors that determine the best glycaemic control on multiple daily insulin (MDI) injections and continuous subcutaneous insulin infusion (CSII), and the hypothesis that blood glucose variability is a major determinant of control and that the resultant HbA1c on MDI correlates with the improvement achieved by CSII. We studied 30 type 1 diabetic subjects already receiving MDI. Renewed attempts to improve control on MDI were made for a median of five months, and then the subjects were switched to CSII. The variability of within‐day and between‐day blood glucose concentrations was calculated from blood glucose self‐monitoring data.

Results

HbA1c during MDI varied from 5.7 to 11.7% (mean ± SD, 8.5 ± 1.4%). Within‐ and between‐day blood glucose variability correlated with HbA1c on MDI (r = 0.59, p < 0.001; r = 0.48, p < 0.03). Within‐day variability remained an independent predictor of HbA1c on MDI. Mean HbA1c improved with CSII (to 7.3 ± 0.9%, p < 0.001), but reduction in HbA1c was variable and was related to the HbA1c on MDI (r = 0.79, p < 0.001) and within‐day variability (r = 0.56, p < 0.01). Similar results were observed for subjects treated only with glargine‐based MDI.

Conclusions

The best glycaemic control achievable on MDI is related to blood glucose variability—those with the largest swings in blood glucose retaining the highest HbA1c. The improvement in control achieved by CSII is related to HbA1c and blood glucose variability on MDI. Pump therapy is most effective in those worst controlled on MDI. Copyright © 2006 John Wiley & Sons, Ltd.
Chiral, Enantiopure Aluminum(III) and Titanium(IV) Azatranes
Authors: Forcato Massimiliano , Lake Fredrik , Mba Blazquez Myriam , Renner Patrick , Crisma Marco , Gade Lutz H. , Licini Giulia , Moberg Christina
Published: January 2006

AlIII and TiIV complexes of C3‐symmetric tetradentate trisamidoamine ligands with trigonal bipyramidal coordination geometry, containing chlorine or dialkylamido groups, or with a free coordination site in the apical position, have been synthesised by salt metathesis and amine elimination. Products with threefold symmetry were generally obtained for tetravalent titanium, whereas for the aluminium complexes either asymmetric structures with two of the three podand arms taking part in coordination to the metal or symmetric arrangements possessing the full threefold symmetry were formed depending on the steric properties of the ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Molecular Structures and Magnetism of Mn12 Nanomagnets Containing the 3‐Thiophenecarboxylate Ligand
Authors: Lim Jin Mook , Do Youngkyu , Kim Jinkwon
Published: January 2006

The new Mn12 single‐molecule magnets containing thiophenyl ligands, [Mn12O12(O2CC4H3S)16(HO2CC4H3S)(H2O)2]·5CH2Cl2(1) and [Mn12O12(O2CC4H3S)16(H2O)4]·6CH2Cl2·2H2O (2), have been synthesized by ligand‐substitution reactions of 3‐thiophenecarboxylic acid and [Mn12O12(O2CCH3)16(H2O)4] and investigated by magnetic measurements with a SQUID magnetometer. The X‐ray analysis of 1 shows five‐coordination geometry around the MnIII ion due to the unusual coordination of 3‐thiophenecarboxylic acid to the MnIII ion. Compound 1 displays two different rates of magnetization relaxation, which are faster than that of compound 2 because of structural distortion in the Mn12 complex of 1. Magnetic susceptibility measurements on 1 and 2 give the following parameters: Ueff (the faster relaxation form of 1) = 51.81 K, 1/τ0 = 1.90·108 s–1; Ueff (the slower relaxation form of 1) = 66.44 K, 1/τ0 = 1.50·108 s–1; Ueff(2) = 67.09 K, 1/τ0 = 1.32·108 s–1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
New Ligands for Rh‐Catalysed Hydroformylation of 1‐Octene in Supercritical Carbon Dioxide – X‐ray Structure of [Rh{PPh2(OC9H19)}4]PF6
Authors: Giménez‐Pedrós Marta , Aghmiz Ali , Ruiz Núria , Masdeu‐Bultó Anna M.
Published: January 2006

The new P‐donor ligands PPh3–n(OC9H19)n (n = 3, 2, 1) containing branched alkyl chains were synthesised and their coordination to RhI and PdII studied. The X‐ray structure of [Rh{PPh2(OC9H19)}4]PF6 was determined. Reaction of the [Rh(acac)(CO)2]/PPh3–n(OC9H19)n systems with CO/H2 at 5 atm and 80 °C in toluene led to the formation of [RhH(CO){PPh3–n(OC9H19)n}3] as the main species. The Rh‐catalysed hydroformylation of 1‐octene with these ligands was investigated in supercritical carbon dioxide (scCO2) and toluene as solvents. Although the catalytic systems are not soluble in scCO2, they are active. The activities are higher in toluene than in scCO2 but the selectivities for aldehydes in the case of the phosphonite derivative are higher in the supercritical medium than in toluene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Strained Dehydrobenzoannulenes
Authors: Hisaki Ichiro , Sonoda Motohiro , Tobe Yoshito
Published: January 2006

Dehydrobenzoannulenes (DBAs) have been attracting a great deal of interest as a result of their potential applications as optoelectronic materials, precursors of new forms of carbon materials, and as building blocks for hitherto‐unknown 2D carbon networks consisting of sp and sp2 carbon atoms. Among the DBAs, those with substantial strain due to bond‐angle deformation at the triple bonds exhibit greater potential as electronic communication units and precursors of new polycyclic, conjugated ring systems owing to their high reactivity towards carbon–carbon bond‐forming reactions. It is also of interest to see how the deformation of triple bonds affects the cyclic conjugation of π systems, that is, the aromaticity/antiaromaticity of DBAs. This article reviews these characteristic aspects of strained DBAs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Selective and Rapid Access to Six‐ or Seven‐Membered Ring Iminosugars via 6,8‐Diazabicyclo[3.2.1]oct‐6‐ene Intermediates
Authors: Tite Tony , Tsimilaza Andriamihamina , Lallemand Marie‐Christine , Tillequin François , Leproux Pascale , Libot Francine , Husson Henri‐Phillipe
Published: January 2006

A selective and rapid access to six‐ or seven‐membered ring iminosugars is reported. The key step of the strategy involves the highly regio‐ and stereoselective reduction of 6,8‐diazabicyclo[3.2.1]oct‐6‐ene intermediates, depending on the nature of imine substituents. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Solvent‐Free Carbon–Oxygen Bond Formation Catalysed by CeCl3·7 H2O/NaI: Tetrahydropyranylation of Hydroxy Groups
Authors: Bartoli Giuseppe , Giovannini Riccardo , Giuliani Arianna , Marcantoni Enrico , Massaccesi Massimo , Melchiorre Paolo , Paoletti Melissa , Sambri Letizia
Published: January 2006

An efficient and highly chemoselective method fo the protection of free hydroxy compounds with 3,4‐dihydro‐2H‐pyran is reported. Since the deprotection of THP‐ethers occurs very readily at room temperature, the successful use of this type of protecting group depends only upon how readily it can be introduced. For this we have examined the tetrahydropyranylation of alcohols and phenols catalysed by the CeCl3·7 H2O/NaI system surface under solvent‐free conditions. The reaction presents the advantage of being performable under extremely mild conditions by use of catalytic amounts of an interesting Lewis acidic system consisting of the CeCl3·7 H2O/NaI catalyst combination, which can be easily separated from the reaction mixture. The advantages of this procedure, which utilizes cheap and “friendly” reagents, over the previously reported ones are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Ring‐Closing Metathesis Pathway to Fluorovinyl‐Containing Nitrogen Heterocyles
Authors: De Matteis Valeria , van Delft Floris L. , Tiebes Jörg , Rutjes Floris P. J. T.
Published: January 2006

The synthesis of highly functionalized fluorinated piperidines is described. The key step in this synthesis is a ring‐closing metathesis reaction involving fluoride‐substituted olefins, which leads to the corresponding cyclic vinyl fluorides. Several sequences to arrive at differently substituted piperidines have been evaluated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Fluorous Capping Strategy for Fmoc‐Based Automated and Manual Solid‐Phase Peptide Synthesis
Authors: Montanari Vittorio , Kumar Krishna
Published: January 2006

Just add water: Peptides synthesized by the use of standardized Fmoc protocols with commercial automated synthesizers can be purified from deletion products by simple centrifugation of aqueous solutions. The deletion products are capped with fluorous trivalent iodonium salts. At the end of the synthesis, the crude peptide is dissolved in water and centrifuged, and the deletion products precipitate leaving only the full length peptide in solution. Protocols for generalized use of this strategy are reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Signal Generation at an Electrochemical Immunosensor via the Direct Oxidation of an Electroactive Label
Authors: Akram Mohammad , Stuart Margaret C. , Wong Danny K. Y.
Published: January 2006

In this paper, we report the development of an electrochemical immunosensor with a direct signal generation scheme. To achieve this, ferrocenecarboxylic acid was conjugated as an electroactive label to an immunocomplex immobilized on an electrochemically pretreated glassy carbon electrode. The pregnancy hormone and tumor marker, human chorionic gonadotrophin (hCG), was employed as a model analyte. Direct oxidation of ferrocenecarboxylic acid facilitated a signal generation scheme for the quantification of hCG at the immunosensor. Evaluation of the immunosensor performance has yielded statistically acceptable agreement in hCG levels present in several human serum samples compared to those reported by a Sydney hospital.
Rapid extraction and analysis of volatile organic compounds of Iranian feverfew (Tanacetum parthenium) using headspace solvent microextraction (HSME), and gas chromatography/mass spectrometry
Authors: Besharati‐Seidani A. , Jabbari A. , Yamini Y. , Saharkhiz M. J.
Published: January 2006

In the present study, we have utilized headspace solvent microextraction (HSME) as a modern and rapid sample preparation method for the isolation and preconcentration of the volatile organic compounds (VOCs) from the headspace of a plant into a microdrop. The extraction was done by suspending a microliter drop of the solvent from the tip of a microsyringe to the headspace of dried and powdered feverfew flowers (Tanacetum parthenium) in a sealed vial for a preset extraction time. Then, the microdrop was retracted back into the microsyringe and injected directly into a GC injection port. In this study, the identification of the VOCs extracted by HSME was confirmed according to their retention indices and mass spectra (EI, 70 eV) and quantitative analysis was performed by GC‐FID. Parameters such as the nature of the extracting solvent, particle size of the sample, temperatures of the microdrop and sample, volumes of the microdrop and sample and the extraction time were studied and optimized and the method performance was evaluated. The optimized conditions were: sample particle size, 0.65 mm; sample volume, 8 ml (in a 15 ml vial); sample temperature, 50 °C; microsyringe needle temperature, 25 °C (room temperature); microdrop volume, 3 µl and extraction time, 8 min. Finally, under optimum working conditions, the percentage of the VOCs extracted from the headspace and the relative standard deviation of the extraction for each compound based on seven replicated analyses were evaluated. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical composition of the volatile oil of aerial parts of Valeriana sisymbriifolia Vahl. grown in Iran
Authors: Javidnia K. , Miri R. , Kamalinejad M. , Khazraii H.
Published: January 2006

The essential oil of Valeriana sisymbriifolia growing wild in Iran was obtained by hydrodistallation and analyzed by GC‐MS technique. Forty‐one components representing 90.2% of the total oil were identified. The main components of the oil were β‐atlantone and 14‐hydroxy‐9‐epi‐(E)‐caryophyllene (16.3%), viridiflorol (11.4%), isovaleric acid (7.3%), (Z)‐α‐bisabolene (5.9%), allo‐aromadendrene‐epoxide (5.5%) and borneol (5.2%). Copyright © 2006 John Wiley & Sons, Ltd.
Geranium (Pelargonium sp. ‘hybrid’) essential oil in subtropical and temperate regions of Jammu and Kashmir
Authors: Bhan M. K. , Dhar A. K. , Choudhary D. K. , Rekha Kanti , Balyan S. S. , Khan S. , Agarwal S. G. , Shawl A. S.
Published: January 2006

Six accessions of geranium (Pelargonium sp. ‘hybrid’) were introduced in temperate and subtropical regions of Jammu and Kashmir. The herbaceous parts in the commercial distillation gave 0.09–0.13% oil on fresh weight basis. The calculated herbage yield (tonnes/ha) and oil yield (litre/ha) varied from 31.5 ± 1.87 to 49.1 ± 2.73 and 32.40 to 57.12, respectively. The geranium oil produced in different regions of Jammu and Kashmir was comparable to that produced in other geranium‐growing areas in India in terms of its major constituents, citronellol (22.5–34.5%) and geraniol (13.9–24.7%), respectively. This suggests that geranium can be successfully grown in the state of Jammu and Kashmir. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical composition of the essential oils of Rubia tinctorum L. aerial parts from Iran
Authors: Navaei Mehrdokht Najafpour , Mirza Mehdi , Dini Mohammad
Published: January 2006

Hydro‐distilled volatile oil from the aerial parts of Rubia tinctorum L. was obtained at yield of 0.1% w/w based on dry weight. The oil was analyzed by a combination of GC and GC‐MS. Thirty‐four components were identified, constituting 96.4% of the oil. The major constituents in the oil were pentadecanal (20.2%), tridecanal (16.7%) and globulol (7.8%). Copyright © 2006 John Wiley & Sons, Ltd.
The essential oil composition of Acroptilon repens (L.) DC. of Turkish origin
Authors: Tunalier Zeynep , Candan Nurcan T. , Demirci Betul , K. Husnu Can Baser
Published: January 2006

The composition of essential oil obtained from the aerial parts of Russian knapweed [Acroptilon repens (L.) DC.] (Asteraceae) was analyzed by GC and GC‐MS. Seventy‐two components were identified in the essential oil of Acroptilon repens (L.) DC. Major constituents of the essential oil were α‐copaene (22.8%), β‐caryophyllene (9.5%), germacrene D (9.0%), β‐cubebene (7.9%) and caryophyllene oxide (6.4%). Copyright © 2006 John Wiley & Sons, Ltd.
How common is the ‘prominence effect’? Additional evidence to Whynes et al.
Authors: Covey Judith , Smith Richard D.
Published: January 2006

In a recent issue of Health Economics Letters, Whynes et al. report an observation not previously reported in the willingness‐to‐pay (WTP) literature; that when people are asked to provide an estimate using payment scales they tend to disproportionately select prominent values (that is, 1, 2, 5, 10, 20, 50, 100, etc.). However, it remains an open question just how common this prominence effect actually is. Here we present data from several additional contingent valuation (CV) studies, which suggest that although prominence occurs, it does not reach statistical significance, as found by Whynes et al. A number of reasons are outlined to explain this. Copyright © 2005 John Wiley & Sons, Ltd.
In defence of societal sovereignty: a comment on Nyman ‘the inclusion of survivor consumption in CUA’
Authors: Richardson Jeffrey R. J. , Olsen Jan Abel
Published: January 2006

Whether to include or exclude consumption costs and costs of unrelated illnesses in economic evaluation is not a technical issue which may be answered by reference to individuals alone and the consistency of the treatment of individual costs and benefits. In the context of a publicly funded health service the relevant costs and benefits may differ from those normally included in evaluation studies. Specifically, the social welfare function is likely to exclude benefits which would result in preferential care for wealthier members of society. But this conclusion must be established by analysis of social, not individual, values. Copyright © 2005 John Wiley & Sons, Ltd.