bluuebunny/crossref_metadata_2025 huggingface dataset:
Dinuclear Zinc‐Catalyzed Asymmetric Desymmetrization of Acyclic 2‐Substituted‐1,3‐Propanediols: A Powerful Entry into Chiral Building Blocks
Authors: Trost Barry M. , Malhotra Sushant , Mino Takashi , Rajapaksa Naomi S.
Published: July 2008

The asymmetric acylation of meso‐2‐substituted‐1,3‐propanediols by using an amphoteric chiral dinuclear zinc catalyst is described. It is has been demonstrated that both 2‐alkyl‐ and 2‐aryl‐1,3‐propanediols can be desymmetrized in high yields and enantioselectivities by using the same family of ligands. Given that both antipodes of the chiral catalyst are available, both enantiomers of the desymmetrized product can be obtained from the same starting material. The synthetic utility of the desymmetrized products has been demonstrated by the synthesis of several chiral building blocks with high enantiomeric purities.
Synthesis and Reactivity of [Penta(4‐halogenophenyl)cyclopentadienyl][hydrotris(indazolyl)borato]ruthenium(II) Complexes: Rotation‐Induced Fosbury Flop in an Organometallic Molecular Turnstile
Authors: Carella Alexandre , Launay Jean‐Pierre , Poteau Romuald , Rapenne Gwénaël
Published: July 2008

The preparation of ruthenium(II) complexes coordinated to a penta(4‐halogeno)phenylcyclopentadienyl ligand and to the hydrotris(indazolyl)borate ligand are detailed. Our strategy involves first the coordination of the penta(4‐bromo)phenylcyclopentadienyl ligand by reaction with the ruthenium–carbonyl cluster followed by the coordination of the tripodal ligand. The pentabrominated precursor was successfully converted to the pentaiodinated derivative by using the Klapars–Buchwald methodology, applied for the first time on organometallic substrates. Cross‐coupling reactions were performed on both pentabromo and pentaiodo complexes to introduce in a single step the five peripheric ferrocenyl fragments required to obtain a potential molecular motor. The two ligands present in the ruthenium complexes undergo a correlated rotation that was established both experimentally by NMR experiments and an X‐ray diffraction study, and theoretically by DFT calculations. The potential‐energy curve obtained by DFT revealed the energy barrier of the gearing mechanism to be only 4.5 kcal mol−1. These sterically highly constrained complexes can be regarded as organometallic molecular turnstiles.
Total Synthesis and Determination of the Absolute Configuration of Guadinomines B and C2
Authors: Hirose Tomoyasu , Sunazuka Toshiaki , Tsuchiya Satoshi , Tanaka Toshiaki , Kojima Yasuhiro , Mori Ryuma , Iwatsuki Masato , Ōmura Satoshi
Published: July 2008

This article describes the determination of the absolute configurations of the guadinomines, which are novel cyclic guanidyl natural products that are inhibitors of the type III secretion system (TTSS) of bacteria. Any compound that interrupts the TTSS of bacteria is potentially an ideal anti‐infectious drug. The reliable asymmetric synthesis of guadinomines has revealed their absolute configurations, which could not have been defined without this synthetic approach. Our report not only describes the asymmetric total synthesis of the title compounds, but also demonstrates the novel concise synthesis of tri‐substituted piperazinone cores as optically pure forms. The novel feature of our method is an intramolecular SN2 cyclization that uses PPh3 and I2 to construct the unique 5‐membered cyclic guanidine substructure.
Aldol reaction catalyzed by a hydrophilic catalyst in aqueous micelle as an enzyme mimic system
Authors: Zhang Hefeng , Zhao Wenshan , Zou Jun , Liu Yi , Li Runtao , Cui Yuanchen
Published: July 2008

Chitosan‐supported L‐proline complex was synthesized and applied as a catalyst for the direct asymmetric aldol reaction in various organic solvents and water as well. It was found that the novel synthesized catalyst was able to efficiently catalyze the aldol reaction in various media. The catalytic capacity and stereoselectivity of the catalyst were obviously improved with the introduction of aqueous micelle, possibly because the micelle functioned as a hydrophobic pocket, like the hydrophobic portion in enzymes. Moreover, the present synthetic catalyst showed performance similar to that of enzymes and could be used as a model of enzyme catalysis to help better understand the mystic mechanism of enzymes. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Enantioselective separation and degradation of the herbicide dichlorprop methyl in sediment
Authors: Ma Yun , Xu Chao , Wen Yuezhong , Liu Weiping
Published: July 2008

Chiral pesticides currently constitute about 50% of all pesticides dosage used in China, and this ratio is increasing as more complex structures are introduced. Dichlorprop methyl (DCPPM) is a chiral herbicide consisting of a pair of enantiomers. In this study, the enantiomeric separation of DCPPM was investigated by gas chromatography (GC) and high‐performance liquid chromatography (HPLC) using chiral stationary phases (CSPs), and its enantiomeric degradation was characterized using a DCPPM‐degrading bacterial strain isolated from an activated sludge from a textile‐printing wastewater treatment plant. Baseline separation by both GC and HPLC was achieved. Incubation with DCPPM‐degrading bacteria in different pH solutions showed that the R enantiomer was preferentially degraded over the S enantiomer of DCPPM. The degradation rate constant decreased with increasing pH in the order of kpH5 ≈ kpH7 >kpH9. In comparison, the enantioselectivity as indicated by EF followed the order of pH 7 > pH 9–pH 5. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Microscale chiral HPLC in support of pharmaceutical process research
Authors: Welch Christopher J.
Published: July 2008

Some recent developments in the use of microscale chiral HPLC for supporting pharmaceutical process research are reviewed, including multiparallel high throughput analysis to support high throughput experimentation studies, rapid multiparallel chromatographic method development, and on‐line reaction monitoring. Green chemistry advantages of the approach include greatly reduced solvent consumption, waste generation, and stationary phase requirement relative to conventional chiral HPLC. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Molecular and supramolecular chirality: R2PI spectroscopy as a tool for the gas‐phase recognition of chiral systems of biological interest
Authors: Speranza Maurizio , Rondino Flaminia , Satta Mauro , Paladini Alessandra , Giardini Anna , Catone Daniele , Piccirillo Susanna
Published: July 2008

In life sciences, diastereomeric chiral molecule/chiral receptor complexes are held together by a different combination of intermolecular forces and are therefore endowed with different stability and reactivity. Determination of these forces, which are normally affected in the condensed phase by solvent and supramolecular interactions, can be accomplished through the generation of diastereomeric complexes in the isolated state and their spectroscopic investigation. This review presents a detailed discussion of the mass resolved Resonant Two Photon Ionization (R2PI‐TOF) technique in supersonic beams and introduces an overview of various other technologies currently available for the spectroscopic study of gas phase chiral molecules and supramolecular systems. It reports case studies primarily from our recent work using R2PI‐TOF methodology for chiral recognition in clusters containing molecules of biological interest. The measurement of absorption spectra, ionization and fragmentation thresholds of diastereomeric clusters by this technique allow the determination of the nature of the intrinsic interactions, which control their formation and which affect their stability and reactivity. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
An operative approach to correct CD spectra distortions due to absorption flattening
Authors: Castiglioni Ettore , Lebon France , Longhi Giovanna , Gangemi Roberto , Abbate Sergio
Published: July 2008

We discuss the influence of absorption flattening (AF) on CD spectra, aiming at finding a simple way to compensate the induced distortions. A simple algebraic formalism is proposed based on an unconventional measuring approach, which makes use of a commercial unit. Validation of the proposed compensation method for AF is conducted not only on the already studied CD Vis spectral region of a Co chiral complex with the use of an AF emulator, but also on the far UV CD spectra of poly‐L‐glutamic acid suspensions with different turbidity levels. Comparison with some correction factors proposed in the literature is presented. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Discrete Arrays of Liquid‐Crystal‐Supported Proteolipid Monolayers as Phantom Cell Surfaces
Authors: Wise Amber R. , Nye Jeffrey A. , Groves Jay T.
Published: July 2008

The phospholipid bilayers of living cell membranes exist almost universally in a liquid state. This enables motion and spatial reorganization of membrane components on multiple length scales, which is an essential feature of many biological processes. There is great interest in the development of molecularly defined interfaces between synthetic materials and living cells. To this end, there is a need for solid substrate materials that can be derivatized with fluid, membrane‐like interfaces. Herein, we describe array fabrication of discrete liquid‐crystal areas supporting phospholipid monolayer membranes, and characterize the interactions with several different membrane surface proteins [avidin series, cholera toxin, green fluorescent protein (GFP), intercellular adhesion molecule (ICAM) and major histocompatibility complex (MHC)]. Three different linkage strategies (biotin, nickel chelating lipids complexing with histidine, and the choleratoxin binding unit (CTB) associating with GM1 are evaluated. Additionally, experiments with live immunological T cells forming active synapses at the interface exhibit the specific nature of the surface.
Space‐time considerations for hematopoietic stem cell transplantation
Authors: Bhattacharya Deepta , Ehrlich Lauren I. Richie , Weissman Irving L.
Published: July 2008

The mammalian blood system contains a multitude of distinct mature cell lineages adapted to serving diverse functional roles. Mutations that abrogate the development or function of one or more of these lineages can lead to profound adverse consequences, such as immunodeficiency, autoimmunity, or anemia. Replacement of hematopoietic stem cells (HSC) that carry such mutations with HSC from a healthy donor can reverse such disorders, but because the risks associated with the procedure are often more serious than the blood disorders themselves, bone marrow transplantation is generally not used to treat a number of relatively common inherited blood diseases. Aside from a number of other problems, risks associated with cytoreductive treatments that create “space” for donor HSC, and the slow kinetics with which immune competence is restored following transplantation hamper progress. This review will focus on how recent studies using experimental model systems may direct future efforts to implement routine use of HSC transplantation to cure inherited blood disorders.
Cover Picture: Distinct molecular composition of blood and lymphatic vascular endothelial cell junctions establishes specific functional barriers within the peripheral lymph node – Eur. J. Immunol. 8/2008
Authors: Pfeiffer Friederike , Kumar Varsha , Butz Stefan , Vestweber Dietmar , Imhof Beat A. , Stein Jens V. , Engelhardt Britta
Published: July 2008

The cover shows a double immunofluorescence staining of ESAM‐1 and PECAM‐1 in the T cell zone of the peripheral lymph node of the mouse. Red immunofluorescence of ESAM‐1 colocalizes with the bright green immunofluorescence of PECAM‐1, resulting in the observed yellow immunofluorescence. Lymphatic endothelial cells express PECAM‐1 but lack ESAM‐1 and hence are manifested as dim green immunofluorescence. The image was taken from the article by Pfeiffer et al. ( pp.

2142–2155)

in which the authors demonstrate that molecularly distinct cellular junctions of blood and lymphatic endothelial cells establish different functional barriers controlling the distribution antigens and immune cells in the peripheral lymph node.
Reactions of Halogens/Interhalogens with Polypyridyl Substrates: The Case of 2,4,6‐Tris(2‐pyridyl)‐1,3,5‐triazine
Authors: Aragoni M. Carla , Arca Massimiliano , Devillanova Francesco A. , Hursthouse Michael B. , Huth Susanne L. , Isaia Francesco , Lippolis Vito , Mancini Annalisa , Verani Gaetano
Published: July 2008

The reactions between 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine (tptz) and halogens (Br2, I2) or interhalogens (ICl, IBr) yielded different products isolated in the solid state. (Htptz+)(Br3–), (Htptz+)(IBr2–), (H3tptz3+)(I3Br4–)(IBr2–)2, and (H3tptz3+)(ICl2–)3, obtained from the reactions between tptz and Br2, IBr, and ICl, were characterized by single‐crystal X‐ray diffraction and FT‐Raman spectroscopy. All compounds are salts containing the protonated donor counterbalanced by polyhalide anions of various complexity. In particular, in (H3tptz3+)(I3Br4–)(IBr2–)2 the first example of a planar I3Br4– moiety can be observed. In the case of the reaction between tptz and I2, the elemental analysis of the product indicates a 1:1 molar ratio between tptz and I2, but the FT‐Raman spectrum is not consistent with the formation of a simple adduct, clearly indicating the simultaneous presence of diiodine and symmetric triiodide. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Copper‐Catalyzed Asymmetric Allylic Alkylation (Eur. J. Org. Chem. 22/2008)
Authors: Falciola Caroline A. , Alexakis Alexandre
Published: July 2008

The cover picture shows a figurative illustration of the copper‐catalytic cycle for the asymmetric allylic alkylation and its powerful stereoselective control over the regio‐, chemo‐ and enantioselective allylic ring opening of oxiranes or SN2′ displacement of leaving groups. This Microreview by C. A. Falciola and A. Alexakis on p. 3765 ff. covers the field from the early stages of diastereoselective procedures to the more recent highly efficient catalytic protocols.
Antibody development to testosterone and its application in capillary electrophoresis‐based immunoassay
Authors: Chen Hong‐Xu , Zhang Xin‐Xiang
Published: July 2008

The present report describes a rapid, simple, and highly selective approach to perform testosterone competitive immunoassay by CE and LIF detection. The method involves using synthesized fluorescence‐labeled testosterone as a tracer to compete with testosterone. Two polyclonal antibodies (antibody (Ab) arised from T‐3‐BSA (Ab3) and Ab arised from T‐17‐BSA (Ab17)) and their respective tracers have been optimized and Ab3 system is used for the quantification of testosterone by CE‐based immunoassay. The method is developed with a wide working range of 3.70–2000 ng/mL and an LOD at 1.11 ng/mL. Tests for normal and positive urine samples show that this method has the potential to be applied in testosterone doping control.
Drug–liposome distribution phenomena studied by capillary electrophoresis‐frontal analysis
Authors: Østergaard Jesper , Jorgensen Lene , Engelbrecht Thomsen Anne , Weng Larsen Susan , Larsen Claus , Jensen Henrik
Published: July 2008

The potential of using CE frontal analysis (CE‐FA) for the study of low‐molecular‐weight drug–liposome interactions was assessed. The interaction of bupivacaine, brompheniramine, chlorpromazine, imipramine, and ropivacaine with net negatively charged 80/20 mol% 1‐oleoyl‐2‐palmitoyl‐sn‐glycero‐3‐phosphocholine/egg yolk phosphatidic acid liposome suspensions in HEPES buffer at pH 7.4 was investigated. The fraction of free drug as a function of lipid concentration was measured and apparent liposome – buffer distribution coefficients were determined for the basic drug substances. The distribution coefficients increased in the order ropivacaine, bupivacaine, brompheniramine, imipramine, and chlorpromazine. The developed CE method was relatively fast allowing estimates of drug–liposome affinity to be obtained within 15 min. CE‐FA may have the potential to become a valuable tool for the characterization of drug–liposome interactions in relation to estimation of drug lipophilicity and for the evaluation of drug distribution in liposomal drug delivery systems.
Development of a temperature gradient focusing method for in situ extraterrestrial biomarker analysis
Authors: Danger Grégoire , Ross David
Published: July 2008

Scanning temperature gradient focusing (TGF) is a recently described technique for the simultaneous concentration and separation of charged analytes. It allows for high analyte peak capacities and low LODs in microcolumn electrophoretic separations. In this paper, we present the application of scanning TGF for chiral separations of amino acids. Using a mixture of seven carboxyfluorescein succinimidyl ester‐labeled amino acids (including five chiral amino acids) which constitute the Mars7 standard, we show that scanning TGF is a very simple and efficient method for chiral separations. The modulation of TGF separation parameters (temperature window, pressure scan rate, temperature range, and chiral selector concentration) allows optimization of peak efficiencies and analyte resolutions. The use of hydroxypropyl‐β‐CD at low concentration (1–5 mmol/L) as a chiral selector, with an appropriate pressure scan rate ( −0.25 Pa/s) and with a low temperature range (3–25°C over 1 cm) provided high resolution between enantiomers (Rs >1.5 for each pair of enantiomers) using a short, 4 cm long capillary. With these new results, the scanning TGF method appears to be a viable method for in situ trace biomarker analysis for future missions to Mars or other solar system bodies.
A chip‐based immunoaffinity capillary electrophoresis assay for assessing hormones in human biological fluids
Authors: Wellner Edward F. , Kalish Heather
Published: July 2008

A chip‐based capillary electrophoresis system has been designed for assessing the concentrations of four hormones in whole human blood, saliva, and urine. The desired analytes were isolated by immunoextraction using a panel of four analyte‐specific antibodies immobilized onto a glass fiber insert within the injection port of the chip. Following extraction, the captured analytes were labeled prior to electro‐elution into the chip separation channel, where they were resolved into four individual peaks in circa 2 min. Quantification of each peak was achieved by on‐line LIF detection and integration of the area under each peak. Comparison to commercial high‐sensitivity immunoassays demonstrated that the chip‐based assay provided fast, accurate, and precise measurements for the analytes under investigation. As the availability of commercially available antibodies rapidly expands, the application of this system will greatly increase. Chip‐based CE separations of multiple analytes from a single sample also provide a significant advantage in the analysis of small samples.
Microchip‐based multiplex electro‐immunosensing system for the detection of cancer biomarkers
Authors: Ko Yong‐Jun , Maeng Joon‐Ho , Ahn Yoomin , Hwang Seung Yong , Cho Nahm‐Gyoo , Lee Seoung‐Hwan
Published: July 2008

Microfluidic‐based microchips have become the focus of research interest for immunoassays and biomarker diagnostics. This is due to their aptitude for high‐throughput processing, small sample volume, and short analysis times. In this paper, we describe the development of a microchip‐based multiplex electro‐immunosensing system for simultaneous detection of cancer biomarkers using gold nanoparticles and silver enhancer. Our microchip is composed of biocompatible poly(PDMS) and glass substrates. To fix the antibody‐immobilized microbeads, we used pillar‐type microfilters within a reaction chamber. An immunogold silver staining (IGSS) method was used to amplify the electrical signal that corresponded to the immunecomplex. To demonstrate this approach, we simultaneously assayed three cancer biomarkers, alpha‐fetoprotein (AFP), carcinoembryonic antigen (CEA), and prostate‐specific antigen (PSA) on the microchip. The electrical signal generated from the result of the immunoreaction was measured and monitored by a PC‐based system. The overall assay time was reduced from 3–8 h to about 55 min when compared to conventional immunoassays. The working range of the proposed microchip was from 10−3 to 10−1 μg/mL of the target antigen.
Simultaneous removal of SO2 and NO by highly reactive absorbent containing calcium hypochlorite
Authors: Zhao Yi , Xu Peiyao , Wang Lidong
Published: July 2008

Fly ash, industrial lime, and an additive [calcium hypochlorite (C)] were used to prepare a highly reactive absorbent. Simultaneous desulfurization and denitrification were carried out in a flue gas circulating fluidized bed (CFB). The effects of influencing factors on the removal efficiencies of SO2 and NO were also investigated. Removal efficiencies of 94.5% for SO2 and 65.5% for NO were obtained under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods. The results indicated that more nitrogen than sulfur species appeared in the spent absorbent. A scanning electron microscope (SEM) and an accessory X‐ray energy spectrometer (EDS) were used to observe the microproperties of the samples, including fly ash, highly reactive absorbent, and spent absorbent. The removal products of spent absorbent were analyzed using ion chromatography and chemical analysis. The simultaneous removal mechanism of SO2 and NO based on this absorbent was proposed according to the experimental results. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
A particle swarm optimization approach for hexahedral mesh smoothing
Authors: Yilmaz A. Egemen , Kuzuoglu Mustafa
Published: July 2008

There are some approaches for all‐hexahedral mesh quality improvement by means of node‐movement while preserving the connectivity. Among these methods, the most easily implemented and well known one is the Laplacian smoothing method; however, for this method mesh quality improvement is not guaranteed in all cases, and this approach might cause inverted elements especially in concave regions. In this work, a method for the improvement of hexahedral mesh shape‐quality without causing inverted elements is proposed; which is based on optimization of an objective function calculated by means of the individual qualities of hexahedral elements in the mesh. The shape‐quality for each hexahedral element is defined via the condition number of the relevant element. The numerical optimization scheme is the particle swarm optimization method, which originated from observations related to the social behaviors of bird, insect, or fish colonies. The purpose of this paper is to discuss the applicability of this approach to mesh smoothing. Some examples are given in order to demonstrate the applicability. Copyright © 2008 John Wiley & Sons, Ltd.
Study of Internal and External Leaks in Tests of Anode‐Supported SOFCs
Authors: Rasmussen J. F. B. , Hendriksen P. V. , Hagen A.
Published: July 2008

A planar anode‐supported solid oxide fuel cell (SOFC) has been tested to investigate gas tightness of the electrolyte and the applied seals. Gas leaks reduce the efficiency of the SOFC and it is thus important to determine and minimise them. Probe gases (He and Ar) and a Quadrupole Mass Spectrometer were used to detect both internal (through electrolyte) and external (through seals) gas leaks. The internal gas leak through the electrolyte was quantified under different conditions, as was the external leak from the surroundings to the anode. The internal gas leak did not depend on the pressure difference between the anode and the cathode gas compartment, and can thus be described as diffusion driven. External leaks between the surroundings and the anode, but not the cathode gas compartment was observed. They were influenced by the pressure difference and are thus driven by both concentration and pressure gradients. The measured gas leaks deduced from the probe gas experiments and the total leak calculated from the deviation between the Emf defined by the gases and the cell OCV (which contains all gas leaks as well as effects of electronic leaks) were compared. Good agreement between the two measures was observed.
Barium Non‐Stoichiometry Role on the Properties of Ba1+xCe0.65Zr0.20Y0.15O3–δ Proton Conductors for IT‐SOFCs
Authors: Barison S. , Battagliarin M. , Cavallin T. , Daolio S. , Doubova L. , Fabrizio M. , Mortalò C. , Boldrini S. , Gerbasi R.
Published: July 2008

Proton conducting perovskite oxides have been widely investigated because of their potential as electrolytes for intermediate temperature solid oxide fuel cells. Among them, BaCeO3‐ based materials exhibit good proton conductivity under a humidified hydrogen‐containing atmosphere, but rather poor chemical stability in CO2 atmosphere. The substitution with Zr for Ce improves the chemical stability but reduces proton conductivity due to difficulties in fabricating dense materials. In the present work, single phase nanostructured powders of Ba1+xCe0.65Zr0.20Y0.15O3–δ (x = 0, 0.05, 0.10) solid solutions have been prepared by a modified sol–gel Pechini method with the final aim of evaluating the role of barium on their chemical and electrical properties. A significant influence of barium excess on the preparation and on properties of these materials has been demonstrated. In fact, density measurements evidenced that a 5 or 10 mol% nominal barium excess sensibly favoured the sintering process. Impedance analyses of sintered pellets confirmed the necessity of barium excess in order to avoid the lowering of proton conductivity, which has been evidenced for samples having stoichiometric barium content. Moreover, an unforeseen increase in chemical stability in CO2‐containing atmosphere with the growth of the barium excess was detected by thermogravimetric analyses.
A predictive depression pattern in mild cognitive impairment
Authors: Houde Michèle , Bergman Howard , Whitehead Victor , Chertkow Howard
Published: July 2008

Objective

To evaluate the prognostic utility of the presence, persistence, and patterns of depression in subjects with amnestic Mild Cognitive Impairment (MCI).

Method

Sixty amnestic MCI patients were assessed cognitively and for presence of depression using the 30 item Geriatric Depression Scale (GDS). They were followed annually for an average period of 4.3 years.

Results

Simple presence or absence of depression at referral did not predict progression of MCI to AD. Positive answers to specific GDS questions referring to “melancholic” affect as well as the persistence of depression over two to three years significantly predicted cognitive deterioration leading to AD.

Conclusion

The affective characteristics of depression at referral and the persistence of depression were better predictors of conversion to AD than the simple presence or absence of depression measured at referral time. Copyright © 2008 John Wiley & Sons, Ltd.
Hepatitis B virus X protein affects S phase progression leading to chromosome segregation defects by binding to damaged DNA binding protein 1
Authors: Martin-Lluesma Silvia , Schaeffer Céline , Robert Eva Isabelle , van Breugel Pieter Cornelis , Leupin Olivier , Hantz Olivier , Strubin Michel
Published: July 2008

Chronic hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma (HCC), but its role in the transformation process remains unclear. HBV encodes a small protein, known as HBx, which is required for infection and has been implicated in hepatocarcinogenesis. Here we show that HBx induces lagging chromosomes during mitosis, which in turn leads to formation of aberrant mitotic spindles and multinucleated cells. These effects require the binding of HBx to UV-damaged DNA binding protein 1 (DDB1), a protein involved in DNA repair and cell cycle regulation, and are unexpectedly attributable to HBx interfering with S-phase progression and not directly with mitotic events. HBx also affects S-phase and induces lagging chromosomes when expressed from its natural viral context and, consequently, exhibits deleterious activities in dividing, but not quiescent, hepatoma cells.

Conclusion:

In addition to its reported role in promoting HBV replication, the binding of HBx to DDB1 may induce genetic instability in regenerating hepatocytes and thereby contribute to HCC development, thus making this HBV–host protein interaction an attractive target for new therapeutic intervention. (Hepatology 2008.)
Reducing risk of shortages due to drought in water supply systems using genetic algorithms
Authors: Nicolosi V. , Cancelliere A. , Rossi G.
Published: July 2008

The evaluation of risk of shortages due to drought in water supply systems is a necessary step both in the planning and in the operation stage. A methodology for unconditional (planning) and conditional (operation) risk evaluation is presented in this study. The risk evaluation is carried out by means of an optimisation model based on genetic algorithms aimed to define thresholds for the implementation of mitigation measures tested through Monte Carlo simulation that makes use of a stochastic generation of streamflows. The GA enables the optimisation of reservoir storages which identify monthly thresholds for shifting three states of the system (normal, alert and alarm) to which correspond different mitigation measures such as water demand rationing, additional supplies from alternative sources or reduction of release for ecological use. For unconditional risk evaluation a long time horizon has been considered (40 years), while the conditional risk evaluation is performed on a short time horizon (2–3 months). Results of simulations have been studied by means of consolidated indices of performance and frequency analysis of shortages of a given entity corresponding to different planning/management policies. A multi‐use water system has been used as a case study including competing irrigation and industrial demands. Copyright © 2008 John Wiley & Sons, Ltd.
Simplified procedure for hydraulic design of small‐diameter plastic pipes
Authors: Yildirim Gürol
Published: July 2008

A simple, direct and efficient semi‐theoretical approach was developed to solve the hydraulic design problem of a horizontal or uphill sloping, single‐diameter multi‐outlet pipe. The proposed simplified model is essentially a design concept ensuring the hydraulic criteria for desired level of water application uniformity and allowable pressure head variation along with the limitation for economical pipe design. In the present technique, one can directly determine the smallest pipe size, pipe length, operating inlet pressure head and corresponding design parameters (pressure head variation, downstream end pressure head, total or friction losses and alternate uniformity expressions) for a desired level of water application uniformity with known design variables. For practical purposes, the design charts were also prepared to quickly determine the required design parameters. A comprehensive comparison test was applied for various design combinations. The examination results reveal that the proposed design technique is sufficiently accurate in comparison with the previous analytical and numerical procedures. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of inhaled monoethanolamine on bronchoconstriction
Authors: Kamijo Y. , Hayashi I. , Ide A. , Yoshimura K. , Soma K. , Majima M.
Published: July 2008

We previously reported a 65‐year‐old man who aspirated an alkaline detergent containing 3.3% w/v (weight of solute per volume of solution) monoethanolamine (MEA) into his lungs, causing asthma‐like symptoms. We presently describe the mechanism of MEA‐induced bronchoconstriction according to findings in guinea pigs. In anesthetized, artificially ventilated animals, changes in airway opening pressure (Pao) were measured as an index of bronchoconstriction. An aerosol of 3.3% MEA solution (0.1 ml kg−1) inhaled through a tracheal cannula induced significantly stronger bronchoconstriction than an aerosol of potassium hydroxide (KOH) solution (0.1 ml kg−1) at the same pH. MEA‐induced bronchoconstriction was significantly suppressed by premedication with intravenously injected atropine sulfate (3 mg kg−1), a muscarinic receptor antagonist, or diphenhydramine hydrochloride (10 mg kg−1), a histamine‐H1receptor antagonist. MEA‐induced bronchoconstriction was not enhanced by premedication with an intravenous injection of neostigmine (0.1 mg kg−1), an acetylcholinesterase inhibitor. When bronchoconstriction was induced by MEA, histamine concentrations in bronchoalveolar lavage fluid (BALF) were not significantly greater than in BALF after KOH‐induced bronchoconstriction or in BALF after inhalation of physiologic saline.In vitro, contraction of trachea denuded of epithelium during superfusion with MEA (10 mm) was suppressed by premedication with pyrilamine maleate, a histamine‐H1receptor antagonist, at 10 and 100 µm. Contraction of trachea denuded of epithelium during superfusion with MEA (10 mm) was suppressed by premedication with atropine sulfate at 10 and 100 µm. These results suggest that asthma‐like symptoms may result partly from agonistic MEA effects at histamine‐H1receptors and muscarinic receptors. Copyright © 2008 John Wiley & Sons, Ltd.
Tracking bio‐molecules in live cells using quantum dots
Authors: Chang Yun‐Pei , Pinaud Fabien , Antelman Joshua , Weiss Shimon
Published: July 2008

Single particle tracking (SPT) techniques were developed to explore bio‐molecules dynamics in live cells at single molecule sensitivity and nanometer spatial resolution. Recent developments in quantum dots (Qdots) surface coating and bio‐conjugation schemes have made them most suitable probes for live cell applications. Here we review recent advancements in using quantum dots as SPT probes for live cell experiments. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhanced bone morphogenetic protein‐2 performance on hydroxyapatite ceramic surfaces
Authors: Schuessele A. , Mayr H. , Tessmar J. , Goepferich A.
Published: July 2008

The immobilization of biomolecules on biomaterial surfaces allows for the control of their localization and retention. In numerous studies, proteins have been simply adsorbed to enhance the biological performance of various materials in vivo. We investigated the potential of surface modification techniques on hydroxyapatite (HA) ceramic discs in an in vitro approach. A novel method for protein immobilization was evaluated using the aminobisphosphonates pamidronate and alendronate, which are strong Ca chelating agents, and was compared with the established silanization technique. Lysozyme and bone morphogenetic protein‐2 (BMP‐2) were used to assess the suitability of the two surface modification methods with regard to the enzymatic activity of lysozyme and to the capacity of BMP‐2 to stimulate the osteoblastic differentiation of C2C12 mouse myoblasts. After immobilization, a 2.5‐fold increase in enzymatic activity of lysozyme wasobserved compared with the control. The alkaline phosphatase activity per cell stimulated by immobilized BMP‐2 was 2.5‐fold higher [9 × 10−6 I.U.] than the growth factor on unmodified surfaces [2–4 × 10−6 I.U.]. With regard to the increase in protein activity, both procedures lead to equivalent results. Thus, the bisphosphonate‐based surface modification represents a safe and easy alternative for the attachment of proteins to HA surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Development of biodegradable and injectable macromers based on poly(ethylene glycol) and diacid monomers
Authors: Kim Jinku , Yaszemski Michael J. , Lu Lichun
Published: July 2008

Novel biodegradable injectable poly(ethylene glycol)‐(PEG) based macromers were synthesized by reacting low‐molecular weight PEG (MW: 200) and dicarboxylic acids such as sebacic acid or terephthalic acid. Chemical structures of the resulting polymers were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy characterizations. Differential scanning calorimetry (DSC) showed that these polymers were completely amorphous above room temperature. After photopolymerization, dynamic elastic shear modulus of the crosslinked polymers was up to 1.5 MPa and compressive modulus was up to 2.2 MPa depending on the polymer composition. The in vitro degradation study showed that mass losses of these polymers were gradually decreased over 23 weeks of period in simulated body fluid. By incorporating up to 30 wt % of 2‐hydroxyethyl methylmethacrylate (HEMA) into the crosslinking network, the dynamic elastic modulus and compressive modulus was significantly increased up to 7.2 and 3.2 MPa, respectively. HEMA incorporation also accelerated the degradation as indicated by substantially higher mass loss of up to 27% after 20 weeks of incubation. Cytocompatability studies using osteoblasts and neural cells revealed that cell metabolic activity on these polymers with or without HEMA was close to the control tissue culture polystyrene. The PEG‐based macromers developed in this study may be useful as scaffolds or cell carriers for tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Differential adhesion of Streptococcus gordonii to anatase and rutile titanium dioxide surfaces with and without functionalization with chlorhexidine
Authors: Barbour Michele E. , Gandhi Nikhil , el‐Turki Adel , O'Sullivan Dominic J. , Jagger Daryll C
Published: July 2008

The majority of dental implants are composed primarily of titanium and have an outer layer of titanium dioxide. Crystalline titanium dioxide most commonly exists in one of the two structures, anatase and rutile, and both of these have been observed on commercially available dental implants. Early implant failure can be associated with postoperative infection due to implant contamination during or immediately after surgery. The impetus of this study was to investigate whether functionalization of anatase and rutile titanium dioxide surfaces with chlorhexidine‐reduced subsequent colonization of the surface by Streptococcus gordonii. Exposure to 100 mg·L−1 chlorhexidine for 60 s resulted in a fivefold reduction in S. gordonii coverage on anatase and a twofold reduction on rutile. This may be related to a preferential adsorption of chlorhexidine to anatase compared with rutile. The reduction in bacterial coverage was not due to desorption of chlorhexidine into solution. More bacteria were observed on anatase than rutile surfaces without chlorhexidine functionalization, indicating that crystal structure may have a significant effect on bacterial colonization. In conclusion, functionalization with chlorhexidine reduced bacterial coverage on titanium dioxide surfaces, and anatase surfaces may be more amenable to such treatment than rutile. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
BASP1 in the lens
Authors: Bagchi M. , Kousis S. , Maisel H.
Published: July 2008

BASP1 was detected in the embryonic and adult chicken lens, using immunological methods and by peptide sequence analysis. The protein was predominantly expressed in fiber cells and only faintly detected in annular pad cells. Localization of the protein was along the plasma membrane of fiber cells often in discrete areas. The role of BASP1 in the lens requires further study. J. Cell. Biochem. 105: 699–702, 2008. © 2008 Wiley‐Liss, Inc.
O‐acetylation of GD3 prevents its apoptotic effect and promotes survival of lymphoblasts in childhood acute lymphoblastic leukaemia
Authors: Mukherjee Kankana , Chava Anil Kumar , Mandal Chandan , Dey Sailendra Nath , Kniep Bernhard , Chandra Sarmila , Mandal Chitra
Published: July 2008

We have previously demonstrated induction of O‐acetylated sialoglycoproteins on lymphoblasts of childhood acute lymphoblastic leukaemia (ALL). These molecules promote survival of lymphoblasts by preventing apoptosis. Although O‐acetylated sialoglycoproteins are over expressed, the status of O‐acetylation of gangliosides and their role in lymphoblasts survival remains to be explored in ALL patients. Here, we have observed enhanced levels of 9‐O‐acetylated GD3 (9‐O‐AcGD3) in the lymphoblasts of patients and leukaemic cell line versus disialoganglioside GD3 in comparison to the normal cells. Localization of GD3 and 9‐O‐AcGD3 on mitochondria of patient's lymphoblasts has been demonstrated by immuno‐electron microscopy. The exogenous administration of GD3‐induced apoptosis in lymphoblasts as evident from the nuclear fragmentation and sub G0/G1 apoptotic peak. In contrast, 9‐O‐AcGD3 failed to induce such apoptosis. We further explored the mitochondria‐dependent pathway triggered during GD3‐induced apoptosis in lymphoblasts. GD3 caused a time‐dependent depolarization of mitochondrial membrane potential, release of cytochrome c and 7.4‐ and 8‐fold increased in caspase 9 and caspase 3 activity respectively. However, under identical conditions, an equimolar concentration of 9‐O‐AcGD3 failed to induce similar effects. Interestingly, 9‐O‐AcGD3 protected the lymphoblasts from GD3‐induced apoptosis when administered in equimolar concentrations simultaneously. In situ de‐O‐acetylation of 9‐O‐AcGD3 with sodium salicylate restores the GD3‐responsiveness to apoptotic signals. Although both GD3 and 9‐O‐acetyl GD3 localize to mitochondria, these two structurally related molecules may play different roles in ALL‐disease biology. Taken together, our results suggest that O‐acetylation of GD3, like that of O‐acetylated sialoglycoproteins, might be a general strategy adopted by leukaemic blasts towards survival in ALL. J. Cell. Biochem. 105: 724–734, 2008. © 2008 Wiley‐Liss, Inc.
Theoretical understanding on the v1‐SO band perturbed by the formation of magnesium sulfate ion pairs
Authors: Zhang Hao , Zhang Yun‐Hong , Wang Feng
Published: July 2008

The factors determining the spectroscopic characteristics of the v1‐SO42− band of the MgSO4 ion pairs are discussed via ab initio calculation, including coupling effect, hydrogen bonding effect, and direct contact effect of Mg2+ with SO42−. With the calculation of the heavy water hydrated contact ion pairs (CIP), the overlap between the librations of water and the v1‐SO42− band can be separated, and thus the coupling effect is abstracted, and this coupling effect leads to a blue shift for the v1‐SO42− band of 5.6 cm−1 in the monodentate CIP and 3.6 cm−1 in the bidentate CIP. The hydrogen bonding between each water molecule without relation to Mg2+ and the sulfate ion makes the v1‐SO42− band blue shift of 3.7 cm−1. When the outer‐sphere water around Mg2+ are hydrogen bonded between SO42− and Mg2+, it will make the largest disturbance to the v1‐SO42− band. Moreover, the inner‐sphere water can affect the v1‐SO42− band conjunct with the direct contact of Mg2+ with SO42−, showing a blue shift of 14.4 cm−1 in the solvent‐shared ion pair, 22.6 cm−1 in the monodentate CIP, 4.3 cm−1 in the bidentate CIP, and 21.4 cm−1 in the tridentate CIP. At last, the Raman spectral evolution in the efflorescence production process is tried to be rationalized. The shoulder at 995 cm−1 is attributed to the monodentate CIP with 2–3 outer‐sphere water molecules, whereas the new peak at 1021 cm−1 at high concentration is assigned to the formation of aqueous triple ion. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Contribution to the study of the vasculature of submandibular and sublingual glands and lymph nodes of rats by corrosion cast technique combined with scanning electron microscopy
Authors: Rossi‐Schneider Tíssiana Rachel , Verli Flaviana Dornela , Yurgel Liliane Soares , De Souza Maria Antonieta Lopes , Cherubini Karen
Published: July 2008

The study of anatomical structures in their normal state allows the identification of pathological changes that can occur in them. Angiogenesis and the vasculature have been widely studied, mainly because of their association with the development of neoplasms. One of the methods applied for such purposes is the corrosion cast technique, which provides a copy of the vessels with normal as well as pathological structures. The replica of the vasculature provided by this technique allows the three‐dimensional analysis of vessels by means of scanning electron microscopy. The aim of the present study was to demonstrate, by means of corrosion casts, the angioarchitecture of the submandibular and sublingual glands and lymph nodes. Scanning electron microscopy showed that the three structures have distinct vascular patterns. The corrosion cast technique can be employed in the study of the angioarchitecture of the submandibular and sublingual glands and lymph nodes, but requires specific precautions. The removal of the structures en bloc and the handling of the replicas with the aid of a stereoscopic magnifier reduce the risk of fractures. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Occurrence of antennal glands in ants
Authors: Renthal Robert , Velasquez Daniel , Olmos David , Vinson S. Bradleigh
Published: July 2008

A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non‐Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Characterization of multimodal hydrophobic interaction chromatography media useful for isolation of green fluorescent proteins with small structural differences
Authors: Becker Kristian , Hallgren Elisabeth , Carredano Enrique , Palmgren Ronnie , Bülow Leif
Published: July 2008

Hydrophobic interaction chromatography (HIC) has been developed as a powerful technique for separating and purifying proteins. In this study, we have characterized the ability of new multimodal pH‐HIC media to resolve proteins with only small differences in their primary structures. This was done by determining the retention times of different green fluorescent protein (GFP) mutants prepared from Escherichia coli extracts. The mutants, modified with single or double hydrophobic amino acid substitutions in two positions, N212 and T230, could be resolved successfully, up to 2.1 column volumes in retention difference for single substitutions and 2.6 column volumes for double substitutions, at two pH and on two media with varying ligand density. The retention times also correlated well with calculated theoretical retentions (R2 = 0.91) using a hydrophobic descriptor. This medium can therefore be very useful in a final polishing step during purification and the protein library prepared represents a good screening set in validating and characterizing new future media due to the accessible, but yet, extremely small differences in protein structure. Copyright © 2008 John Wiley & Sons, Ltd.