bluuebunny/crossref_metadata_2025 huggingface dataset:
Agglomeration of biomass fired fluidized bed gasifier and combustor
Authors: Mettanant Vichuda , Basu Prabir , Butler James
Published: September 2009

Agglomeration is a major problem in biomass fired fluidized bed combustors and gasifiers. Mechanism, reduction options and detection techniques of agglomeration are reviewed. Agglomeration may be classified broadly into three types: defluidization induced agglomeration, melt‐induced agglomeration and coating‐induced agglomeration. Sodium and potassium content of the biomass are the major contributors to the agglomeration in biomass fired fluidized beds. Higher temperature, lower fluidizing velocity and coarser bed particles also increase the risk of agglomeration. Alternative bed materials, additives or the co‐combustion of biomass with other fuels can reduce agglomeration potential of a fluidized bed. Two agglomeration detection techniques are discussed: controlled fluidized bed agglomeration and early agglomeration recognition system.
Two‐level cooperative and energy‐efficient tracking algorithm in wireless sensor networks
Authors: Wang Guojun , Bhuiyan Md. Zakirul Alam , Zhang Li
Published: September 2009

Conventional target tracking systems are based on powerful sensor nodes, capable of detecting and locating a target in a large deployment area but most systems require high transmission power levels and a large volume of messages, much time for neighbor discovery operations, and many sensors to detect the target at a given time. We propose a two‐level cooperative and energy‐efficient tracking algorithm (CET) that reduces energy consumption by requiring only a minimum number of sensor nodes to participate in communication, transaction, and perform sensing for target tracking in wireless sensor networks. It is expected that only the nodes adjacent to the target are responsible for observing the target to save the energy consumption and extend the network lifetime as well by using a wakeup mechanism and a face‐aware routing. Through performance analysis and simulation studies, we demonstrate that CET improves target capturing speed and outperforms some existing protocols of target tracking with energy saving under certain ideal situations. Copyright © 2009 John Wiley & Sons, Ltd.
Uniform Mesoporous Silica Hexagon and Its Two‐Dimensional Colloidal Crystal
Authors: Lin Yu‐Shen , Lu Chun‐Yi David , Hung Yann , Mou Chung‐Yuan
Published: September 2009

Well‐ordered mesoporous silica nanoparticles with uniform hexagonal disk shapes are synthesized under dilute alkaline conditions with a two‐step process, separating the nucleation and growth process. The resulting monodisperse hexagons can be arranged in a 2‐dimensional (2D) ordered periodical super‐structure. The hexagonal symmetry is similar in both scales. A statistical mechanical cell model is applied to analyze consequences of the interesting packing structure, including osmotic bulk modulus, phase separation and defects.
Preferred Hydrogen Adsorption Sites in Various MOFs—A Comparative Computational Study
Authors: Fischer Michael , Hoffmann Frank , Fröba Michael
Published: September 2009

Force‐field based grand‐canonical Monte Carlo simulations are employed to predict the hydrogen adsorption properties of seven structurally different MOFs. The performance of different parameter sets is assessed by comparison with experimental data, and the capabilities and limitations of the methodology are critically discussed, with a particular emphasis on systems with unsaturated metal sites. In addition to adsorption isotherms and isosteric heats of adsorption, the preferred adsorption sites are obtained from a detailed analysis of the calculated hydrogen density fields. Where possible, these positions are compared to the results of neutron diffraction experiments. This study highlights the capabilities of computational methods to identify the structural features which are most favourable for hydrogen adsorption, providing valuable implications for the synthesis of novel MOFs.
Effect of Film Thickness on the Columnar Packing Structures of Discotic Supramolecules in Thin Films
Authors: Kim Hyo‐Sik , Choi Sung‐Min , Pate Brian D. , Park Po Gyu
Published: September 2009

The effects of film thickness on the columnar packing structure of discotic supramolecules in a thin supported film have been investigated by grazing‐incidence small‐angle X‐ray scattering technique using magnetically aligned cobalt octa(n‐decylthio)porphyrazine (CoS10) films on octadecyltrichlorosilane (OTS)‐functionalized substrates as model systems. Magnetically aligned CoS10 films with a range of film thicknesses (49–845 nm) form uniaxially oriented ‘edge‐on’ columnar superstructures with their columnar directors perpendicular to the applied magnetic field. However, the orientational ordering of the columnar packing in the plane perpendicular to the applied magnetic field is strongly dependent on the film thickness. While being damped by the elasticity of the side chains of CoS10, the strong interfacial interaction at the film‐substrate interface propagates up to 50–100 nm from the substrate, maintaining the orientation of columnar packing in the plane perpendicular to the applied magnetic field. When the distance from the film‐substrate interface becomes larger than about 100 nm, symmetric tilting of columnar layer orientation, which saturates at 11.5°, occurs due to longitudinal edge dislocations induced by accumulated elastic deformation.
Homolytic versus Heterolytic Dissociation of Alkalimetal Halides: The Effect of Microsolvation
Authors: Osuna Sílvia , Swart Marcel , Baerends Evert Jan , Bickelhaupt F. Matthias , Solà Miquel
Published: September 2009

Herein we report density functional calculations of homolytic and heterolytic dissociation energies of the diatomic alkalimetal halides MX (M=Li, Na, K, Rb, and Cs and X=F, Cl, Br, I, and At) and their corresponding microsolvated structures MX⋅(H2O)n (n=1 to 4). Our results show that the homolytic dissociation energy of the MX⋅(H2O)n species increases with the number of water molecules involved in the microsolvated salts. On the other hand, the heterolytic dissociation energy follows exactly the opposite trend. As a result, while for the isolated diatomic alkalimetal halides, homolytic dissociation is always favored over heterolytic dissociation, the latter is preferred for CsF and CsCl already for n=2, and for n=4 it is the preferential mode of dissociation for more than half of the species studied.
Helical Fibrous Nanostructures Self‐Assembled from Metal‐Free Phthalocyanine with Peripheral Chiral Menthol Units
Authors: Lv Wei , Wu Xingcui , Bian Yongzhong , Jiang Jianzhuang , Zhang Xiaomei
Published: September 2009

(D)‐ and (L)‐enantiomers of a novel metal‐free 2(3),9(10),16(17),23(24)‐tetrakis(2‐isopropyl‐5‐methylcyclohexoxyl)phthalocyanine (1) with four chiral menthol units attached at the peripheral positions of a phthalocyanine ligand have been synthesized, and characterized. Neither the (D)‐1 nor the (L)‐1 enantiomer display a circular dichroism (CD) signal in the Soret and Q absorption region of the phthalocyanine ligand, indicating the lack of effective chiral information transfer from the chiral menthol tails to the phthalocyanine chromophore at the molecular level. Their self‐assembly properties were systematically studied by CD spectroscopy, transmission electron microscopy, scanning electron microscopy, and atom force microscopy technique. Although four constitutional stereoisomers of each enantiomer were synthesized, because the four chiral menthol substituents are randomly located at peripheral positions of the phthalocyanine ring, cooperation of intermolecular π–π interactions between the phthalocyanine rings with chiral discrimination of the chiral side chains of the (D)‐1 and the (L)‐1 enantiomer induces the formation of one‐dimensional helices with left‐ and right‐handed helical molecular arrangement, respectively, according to the CD spectroscopic results. This reveals the effective chiral information transfer from the chiral menthol tails to the phthalocyanine chromophore at the supermolecular level. The formed one‐dimensional helices twist around each other to maximize the van der Waals interaction, leading to the formation of highly ordered fibrous nanostructures with both right‐ and left‐handed helicity according to the staggering angles between the neighboring phthalocyanine molecules, indicating the hierarchical formation of these fibrous nanostructures. Careful inspection of these nanofibers indicates the majority of nanofibers with right‐ and left‐handed helicity formed from (D)‐1 and (L)‐1 enantiomer, respectively, with the ratio of approximately 1.3–1.4:1 among all the fibrous nanostructures obtained. Electronic absorption spectroscopic and X‐ray diffraction results reveal the H‐aggregate nature of these nanofibers. The present results, showing part of our continuous effort towards preparation of self‐assembled nanostructures with helical morphology through molecular design and synthesis, will be helpful on providing new insight into chiral information transfer and expression for synthetic conjugated systems at the supermolecular level.
Fine needle aspiration of pleomorphic lipoma of the neck: Report of two cases
Authors: Chen Xiaowei , Yu Kathy , Tong Guo‐Xia , Hood Melanie , Storper Ian , Hamele‐Bena Diane
Published: September 2009

Pleomorphic lipoma is a rare lipocytic neoplasm that most commonly occurs in the head and neck region in middle‐aged to elderly men. Clinically, it presents as a slow‐growing, wellcircumscribed subcutaneous mass. Histopathologically and cytogenetically, it has some features overlapping with other benign and malignant tumors, such as benign spindle cell lipoma, atypical lipomatous tumor, liposarcoma, and malignant fibrous histiocytoma. However, cure rates are high when pleomorphic lipoma is treated with complete surgical excision with clear margins. Therefore, an accurate preoperative diagnosis is very important for proper treatment. Due to the rarity of this tumor, few cases diagnosed by cytology have been reported in the English literature. Here, we report two cases of pleomorphic lipoma, the diagnoses of which were suggested on fine needle aspiration biopsies and subsequently confirmed by surgical excisions. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.
Atypical functional lateralization in children with fetal alcohol syndrome
Authors: Domellöf Erik , Rönnqvist Louise , Titran Maurice , Esseily Rana , Fagard Jacqueline
Published: September 2009

In order to explore effects of prenatal alcohol exposure on functional lateralization, item tasks measuring preferences of hand, foot, eye, and ear were administered to a sample of 23 children diagnosed with fetal alcohol syndrome (FAS) compared with typically developing (TD) children. In addition, a dichotic listening task was administered to a subsample of 11 children with FAS and a TD group of comparable age, sex and handedness. The children with FAS were characterized by increased nonright‐handedness compared with TD children. No differences were evident for preferential use of foot, eye, or ear. Moreover, children with FAS displayed more right ear extinctions during dichotic listening relative to TD children, indicating a lack of right ear advantage. The results add to findings of decreased manual asymmetry and less left‐lateralized speech perception in children with developmental disorders, and are further discussed in relation to the high incidence of callosal abnormalities in alcohol‐exposed children. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 696–705, 2009
Involvement of hypoxia‐inducible factor‐1 HiF(1α) in IgE‐mediated primary human basophil responses
Authors: Sumbayev Vadim V. , Nicholas Sally A. , Streatfield Claire L. , Gibbs Bernhard F.
Published: September 2009

Basophils play a pivotal role in regulating chronic allergic inflammation as well as angiogenesis. Here, we show for the first time that IgE‐mediated activation of primary human basophils results in protein accumulation of the α‐subunit of hypoxia‐inducible factor 1α (HIF‐1α), which is differentially regulated compared with signals controlling histamine release. HIF‐1 facilitates cellular adaptation to hypoxic conditions such as inflammation and tumour growth by controlling glycolysis, angiogenesis and cell adhesion. ERK and p38 MAPK, but not reactive oxygen species (ROS), ASK1 or PI 3‐kinase, were critical for IgE‐mediated accumulation of HIF‐1α, although the latter crucially affected degranulation. Abrogating HIF‐1α expression in basophils using siRNA demonstrated that this protein is essential for vascular endothelial growth factor (VEGF) mRNA expression and, consequently, release of VEGF protein. In addition, HIF‐1α protein alters IgE‐induced ATP depletion in basophils, thus also supporting the production of the pro‐allergic cytokine IL‐4.
Novel Neutral and Cationic Aluminium Alkyl Complexes Supported by Potentially Tridentate O,N,L‐Type Aminophenolate Ligands and Their Use in Propylene Oxide Polymerization
Authors: Issenhuth Jean‐Thomas , Pluvinage Julien , Welter Richard , Bellemin‐Laponnaz Stéphane , Dagorne Samuel
Published: September 2009

Potentially tridentate O,N,L‐type aminophenol proligands of the type 2‐{CH2N(C4H8L)}‐6‐R‐C6H3OH (1a: R = Ph, L = O; 1b: R = Ph, L = NMe; 1c: R = tBu, L = O; 1d: R = tBu, L′ = NMe) and 6‐{CH2L}‐2‐CPh3‐4‐Me‐C6H2OH (1e: R = CPh3, L = O; 1f: R = CPh3, L′ = NMe) readily react with AlMe3 through an alkane elimination reaction to afford the corresponding aminophenolate aluminium dimethyl complexes η2‐N,O‐[2‐{CH2N(C4H8L)}‐6‐R‐C6H3O]AlMe2 (2a: R = Ph, L = O; 2b: R = Ph, L = NMe; 2c: R = tBu, L = O; 2d: R = tBu, L′ = NMe) and η2‐N,O‐[6‐{CH2(C4H8L)}‐2‐CPh3‐4‐Me‐C6H2O]AlMe2 (2e: R = CPh3, L = O; 2f: R = CPh3, L′ = NMe), respectively, as determined by X‐ray crystallography in the case of compounds 2b–e. These neutral Al dimethyl complexes all feature a (η2‐O,N)Al chelate, whether in solution or in the solid state, and complexes 2a, 2b, 2d and 2f may be readily ionized by B(C6F5)3 to yield Al cations of the type (η3‐O,N, L)AlMe+ (3a, 3b+, 3d+ and 3f+) as dissociated MeB(C6F5)3– salts in solution. The stability of these Al cations appears to be greatly dependent on the steric crowding around the Al centre. Despite ring strain associated with the coordination of the extra L ligand, the solution behaviour of such Al cations are consistent with the effective coordination of the extra L ligand to the Al metal centre under the studied conditions. Some of these cations were found to be highly active in propylene oxide (PO) polymerization under mild conditions to yield atactic PPO with a moderate polydispersity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Conformational Control in Metallofoldamers: Design, Synthesis and Structural Properties
Authors: Maayan Galia
Published: September 2009

Metallofoldamers are sequence‐specific oligomers, which are designed to fold into three‐dimensional architectures upon metal coordination. Their folding can involve additional noncovalent interactions and results in new chiral secondary structures, enhanced stabilization of existing secondary structures, or unique materials for specific applications. This microreview highlights recent advances in the field.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Post‐Modification Strategy for the Synthesis of Uniform, Hydrophilic/Hydrophobic Patterned α‐Hydroxy Acid Oligomers
Authors: Franz Nadja , Menin Laure , Klok Harm‐Anton
Published: September 2009

Hydrophilic/hydrophobic patterning is a well‐established design strategy to guide secondary structure formation of both natural as well as non‐natural oligomers and polymers. This contribution explores the feasibility of a new approach for the synthesis of uniform, sequence‐defined, hydrophilic/hydrophobic patterned oligo(α‐hydroxy acid)s. The proposed strategy is based on post‐modification of a reactive oligoester scaffold composed of an alternating sequence of hydrophobic [(2S)‐2‐hydroxy‐4‐methylpentanoic acid] and masked hydrophilic [(2S)‐2‐hydroxypent‐4‐enoic acid] α‐hydroxy acids. The use of (2S)‐2‐hydroxypent‐4‐enoic acid instead of a complex side‐chain‐protected hydrophilic building block obviates the need for additional protective group chemistry during chain extension. In a subsequent post‐modification step, the allyl side chains can be quantitatively modified via free‐radical addition of different ω‐functional thiols to afford hydrophilic/hydrophobic patterned oligoesters. The proposed synthetic strategy provides an interesting alternative to rapidly generate libraries of foldamers with identical chain length and monomer sequence but different side‐chain functionalities.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Copper(I)‐Catalyzed Cascade Synthesis of 2‐Substituted 1,3‐Benzothiazoles: Direct Access to Benzothiazolones
Authors: Murru Siva , Mondal Pravat , Yella Ramesh , Patel Bhisma K.
Published: September 2009

An efficient cascade process for the preparation of 2‐substituted 1,3‐benzothiazoles directly from 2‐haloaryl isothiocyanates and O or S nucleophiles by a Cu‐catalyzed, intramolecular, C–S bond formation has been developed. This cascade method is viable for the efficient syntheses of both O‐ and S‐substituted 1,3‐benzothiazoles. Furthermore, 1,3‐benzothiazol‐2(3H)‐ones having an alkyl group allow easy access to 1,3‐benzothiazolones. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Towards the Preparation of Electrochromic Materials with Strong Absorption in the Near‐Infrared Region: Synthesis and Redox Behavior of Azulene‐Substituted Enediyne Scaffolds Connected by a 9,10‐Anthracenediyl Spacer
Authors: Ito Shunji , Iida Takahiro , Kawakami Jun , Okujima Tetsuo , Morita Noboru
Published: September 2009

Enediyne scaffolds connected by a 9,10‐anthracenediyl spacer as a redox‐active substructure with 6‐azulenyl groups as π‐electron‐accepting groups in their periphery (3a and 3b) have been prepared by a one‐pot reaction involving repeated Pd‐catalyzed alkynylation of 6‐haloazulenes 7b and 7c with bis(enediyne) derivative 6. The azulene‐substituted bis(enediyne)s 3a and 3b exhibited two reversible one‐step, two‐electron reduction properties upon cyclic voltammetry (CV) attributable to the formation of dianionic and tetraanionic species. The electrochemical reduction of 3a and 3b led a strong absorption in the near‐IR region corresponding to the formation of the stabilized dianionic species 3aRED2– and 3bRED2–. An electrochromic analysis revealed the lower stability of the tetraanionic species 3aRED4–·· and 3bRED4–··, although the CV exhibited good reversibility. The mono(enediyne) systems 11a and 11b were also prepared for comparison. The electrochemical reduction of 11a and 11b did not exhibit good electrochemical reversibility by CV, but the electrochemical reduction led to a strong absorption in the near‐IR region, similar to the formation of the stabilized dianionic species 3aRED2– and 3bRED2– in the bis(enediyne) systems. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Efficient recovery of electrophoretic profiles of nucleoside metabolites from urine samples by multivariate curve resolution
Authors: Szymańska Ewa , Markuszewski Michał J. , Vander Heyden Yvan , Kaliszan Roman
Published: September 2009

Chemometric techniques usually employed in purity assessment and resolution of multicomponent peaks have been applied to analytical data from complex biological samples obtained with CE‐DAD. In the assessment of the purity of the electrophoretic peaks, the orthogonal projection approach, the orthogonal projection approach with Durbin–Watson criterion, and the simple‐to‐use interactive self‐modeling mixture analysis method have been employed. Multivariate curve resolution with alternating least squares has been successfully implemented to resolve co‐migrating peaks of metabolites in CE‐DAD and to recover qualitative and quantitative information about co‐migrating components of urine extract. The main challenge consisted of developing high‐quality multivariate curve resolution with alternating least squares models of multicomponent peaks acquired during the CE analysis of nucleoside patterns in 18 urine samples. The recovered ultraviolet visible (UV–Vis) spectra have been employed to identify additional nucleosides, such as 1‐methylinosine, 2‐methylguanosine, and 1‐methylguanosine, whose presence in the metabolic profile produced by the applied CE‐DAD method has not yet been recognized. Concentration profiles of these compounds can be used in metabonomic studies.
Improvement of gel‐separated protein identification by DMF‐assisted digestion and peptide recovery after electroblotting
Authors: Lin Yong , Li Yan , Liu Yi , Han Wenjun , He Quanze , Li Jianglin , Chen Ping , Wang Xianchun , Liang Songping
Published: September 2009

In‐gel digestion of gel‐separated proteins is a major route to assist in proteomics‐based biological discovery, which, however, is often embarrassed by its inherent limitations such as the low digestion efficiency and the low recovery of proteolytic peptides. For overcoming these limitations, many efforts have been directed at developing alternative methods to avoid the in‐digestion. Here, we present a new method for efficient protein digestion and tryptic peptide recovery, which involved electroblotting gel‐separated proteins onto a PVDF membrane, excising the PVDF bands containing protein of interest, and dissolving the bands with pure DMF (≥99.8%). Before tryptic digestion, NH4HCO3 buffer was added to moderately adjust the DMF concentration (to 40%) in order for trypsin to exert its activity. Experimental results using protein standards showed that, due to actions of DMF in dissolving PVDF membrane and the membrane‐bound substances, the proteins were virtually in‐solution digested in DMF‐containing buffer. This protocol allowed more efficient digestion and peptide recovery, thereby increasing the sequence coverage and the confidence of protein identification. The comparative study using rat hippocampal membrane‐enriched sample showed that the method was superior to the reported on‐membrane tryptic digestion for further protein identification, including low abundant and/or highly hydrophobic membrane proteins.
Analyzing and monitoring of phage–bacteria interaction using CE
Authors: Soykut Esra Acar , Boyacι İsmail Hakkι
Published: September 2009

The utilization of CE for monitoring bacteria–phage interaction was investigated in this study. Streptococcus thermophilus and Lactobacillus bulgaricus strains and their phages were used as model bacteria and phages for the purpose of validation in this study. CE with heterogeneous polymer polyethylene oxide was utilized for the separation of intact bacteria and investigation of phage–bacteria interaction. An intact phage detection was carried out with CZE by adding SDS in the running buffer. Calibration graphs of bacteria and phages were obtained with R2 values of 0.963 and 0.937, respectively. S. thermophilus strain was infected with its virulent phage B3‐X18 for investigation of phage–bacteria interaction. It was observed in capillary electropherogram that the culture was lysed depending on the multiplicity of infection value and it showed to be completely lysed when the multiplicity of infection value was 10. The interaction of S. thermophilus strain with L. bulgaricus phage was also investigated by using a CE and a microbiological method and it was observed that the L. bulgaricus phage attached itself to the cell wall of S. thermophilus strain without damaging the cell.
Dynamic light‐scattering measurement of sieving polymer solutions for protein separation on SDS CE
Authors: Sumitomo Keiko , Mayumi Koichi , Yokoyama Hideaki , Sakai Yasuhiro , Minamikawa Hiroyuki , Masuda Mitsutoshi , Shimizu Toshimi , Ito Kohzo , Yamaguchi Yoshinori
Published: September 2009

We evaluated the mesh size and homogeneity of polymer network by dynamic light scattering and discussed the relationship between the physical properties of polymer network and the protein separation behavior by capillary polymer electrophoresis. We compared three kinds of sieving polymers in solutions with a wide range of molecular weights and concentrations: polyacrylamide and polyethylene oxide as flexible polymers, and hydroxyethyl cellulose as a semiflexible polymer. We found that the mobility of protein was dominated primarily by the mesh size ξ, irrespective of the type of sieving polymers, and the peak spacing between protein peaks increased drastically in the range of ξ<10 nm, where the mobility also decreased. And the peak widths were dependent on the molecular species of sieving polymers and their homogeneity of polymer network. We proposed that a polymer network with a homogenous mesh size of less than 10 nm is the best sieving medium for separation of the proteins in the molecular weight range 14 300–97 200 Da from the view point of the resolution in protein separation.
Proteomic characterization of plasma‐derived clotting factor VIII–von Willebrand factor concentrates
Authors: Clifton James G. , Huang Feilei , Kovac Spomenka , Yang Xinli , Hixson Douglas C. , Josic Djuro
Published: September 2009

Proteomic methods were used to identify the levels of impurities in three commercial plasma‐derived clotting factor VIII‐von Willebrand factor (FVIII/VWF) concentrates. In all three concentrates, significant amounts of other plasma proteins were found. In Octanate and Haemoctin, two concentrates developed in the 1990s, the major impurities identified were inter‐α inhibitor proteins, fibrinogen and fibronectin. These two concentrates were also found to contain additional components such as clotting factor II (prothrombin) that are known activators of FVIII. In Wilate, a recently developed FVIII/VWF concentrate, the amount of these impurities was significantly reduced. Batch‐to‐batch variations and differences between three investigated products were detected using iTRAQ, an isotope labeling technique for comparative MS, demonstrating the potential value of this technique for quality control analysis. The importance of thorough proteomic investigations of therapeutic FVIII/VWF preparations from human plasma is also discussed.
Three New Triterpene Saponins from Hemsleya chinensis
Authors: Li Zhen‐Jie , Chen Jian‐Chao , Sun Yun , Song Na‐Li , Cheng Bao‐Hui , Lu Lu , Ma Wei‐Guang , Zhou Lin , Zhang Xian‐Min , Li Zhong‐Rong , Qiu Ming‐Hua
Published: September 2009

Three new triterpenoid saponins, xuedanglycosides A–C (1–3, resp.), along with six known ones, were isolated from the rhizomes of Hemsleya chinensis. By detailed analysis of the NMR spectra, by chemical methods, and by comparison with spectral data of known compounds, the structures of new compounds were determined to be 16α,23α‐epoxy‐2β,3α,20β‐trihydroxy‐10α,23α‐cucurbita‐5,24‐dien‐11‐on‐2‐yl β‐D‐glucopyranoside (1), 2β,3α,16α,20β‐tetrahydroxycucurbita‐5,25‐diene‐11,22‐dion‐2‐yl β‐D‐glucopyranoside (2), and oleanolic acid 28‐O‐β‐xylopyranosyl‐(1→6)‐O‐β‐glucopyranoside (3). In addition, hemslecin A 2‐O‐β‐D‐glucopyranoside (6), hemsamabilinin B (7), and hemslonin A (9) were obtained for the first time from this plant.
Prenylated Phenols from Sabia japonica
Authors: Yu Juan , Zhang Hao‐Hao , Yu Qiang , Xuan Li‐Jiang
Published: September 2009

Six prenylated phenols, sabphenols A and B (1 and 2, resp.), and sabphenosides A–D (3–6, resp.), along with eight known constituents, were isolated from the rhizomes of Sabia japonica Max. Their structures were established on the basis of 1D‐ and 2D‐NMR spectral analysis.
Chemoselectivity of the Reactions of Diazomethanes with 5‐Benzylidene‐3‐phenylrhodanine
Authors: Seyfried Martin S. , Linden Anthony , Mlostoń Grzegorz , Heimgartner Heinz
Published: September 2009

The reactions of 5‐benzylidene‐3‐phenylrhodanine (2; rhodanine=2‐thioxo‐1,3‐thiazolidin‐4‐one) with diazomethane (7a) and phenyldiazomethane (7b) occurred chemoselectively at the exocyclic CC bond to give the spirocyclopropane derivatives 9 and, in the case of 7a, also the C‐methylated products 8 (Scheme 1). In contrast, diphenyldiazomethane (7c) reacted exclusively with the CS group leading to the 2‐(diphenylmethylidene)‐1,3‐thiazolidine 11 via [2+3] cycloaddition and a ‘two‐fold extrusion reaction’. Treatment of 8 or 9b with an excess of 7a in refluxing CH2Cl2 and in THF at room temperature in the presence of [Rh2(OAc)4], respectively, led to the 1,3‐thiazolidine‐2,4‐diones 15 and 20, respectively, i.e., the products of the hydrolysis of the intermediate thiocarbonyl ylide. On the other hand, the reactions with 7b and 7c in boiling toluene yielded the corresponding 2‐methylidene derivatives 16, 21a, and 21b. Finally, the reaction of 11 with 7a occurred exclusively at the electron‐poor CC bond, which is conjugated with the CO group. In addition to the spirocyclopropane 23, the C‐methylated 22 was formed as a minor product. The structures of the products (Z)‐8, 9a, 9b, 11, and 23 were established by X‐ray crystallography.
Clofarabine in the treatment of poor risk acute myeloid leukaemia
Authors: Krawczyk Janusz , Ansar Naeem , Swords Ronan , Murphy Tracy , MacDonagh Barry , Meenaghan Teresa , Hayden Patrick , Hayad Amjad , Murray Margaret , O'Dwyer Michael
Published: September 2009

Clofarabine is a second generation nucleoside analogue. It inhibits DNA repair and activates the mitochondrial apoptotic pathway leading to cell death. In vitro clofarabine has demonstrated synergy with daunorubicin and Ara‐C and in phase II clinical trials has shown promising activity in poor risk Acute myeloid leukaemia (AML) patients. In our institution over a 24 month period 22 AML patients (11 M, 11 F) with poor risk features, deemed unsuitable for standard therapy, were treated with clofarabine, alone (eight patients) or in combination (14 patients) for up to three cycles of treatment. The median age was 67.5 years (24–76) with 16 patients > 60 years. At the time of treatment 18 patients had active AML. Four patients intolerant of standard induction received clofarabine as consolidation. The overall response rate (ORR) for the 18 patients with active AML was 61%, nine patients (50%) achieving a complete response (CR). Induction and consolidation were well tolerated with no unexpected toxicities. Predictably, all patients developed grade 4 neutropenia but the median duration was only 20 days (17–120). Induction mortality was acceptable at 17%. In conclusion, clofarabine (alone or in combination) is active in poor risk AML with an acceptable safety profile and should be considered a potential option in poor risk AML patients. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of FGF2 and PEG hydrogel matrix properties on hMSC viability and spreading
Authors: King William J. , Jongpaiboonkit Leenaporn , Murphy William L.
Published: September 2009

In this study, three‐dimensional (3‐D) poly(ethylene glycol) (PEG) hydrogel arrays were used to screen for the effects of fibroblast growth factor‐2 (FGF2), combined with multiple hydrogel matrix parameters, on human mesenchymal stem cell (hMSC) viability and spreading. In particular, we examined the effects of FGF2 while co‐varying hydrogel matrix degradability, cell adhesion ligand type, and cell adhesion ligand density. FGF2 significantly improved viability of hMSCs in a dose‐dependent manner in both nondegrading and degrading PEG hydrogels in the absence of extracellular matrix‐derived cell adhesion ligands. The presence of a small molecule that inhibits autophosphorylation of the FGF2 receptor blocked the effects of FGF2 on hMSC viability in PEG hydrogels, both in the presence and absence of the Arg‐Gly‐Asp‐Ser‐Pro (RGDSP) ligand. FGF2 effects on hMSC viability were less pronounced when FGF2 was presented in combination with the RGDSP cell adhesion ligand or the IKVAV cell adhesion ligand in nondegrading PEG hydrogels. Importantly, spread hMSC morphologies were observed and quantified in a select subset of hydrogel networks, which were degradable and included both FGF2 and RGDSP. These results indicate that the hydrogel arrays described here can be used to efficiently study the influence of soluble and insoluble hydrogel matrix parameters on stem cell behavior, and to identify synthetic, 3‐D environments that promote specific hMSC behaviors. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Porous hollow membrane sheet for tissue engineering applications
Authors: Hadjizadeh Afra , Mohebbi‐Kalhori Davod
Published: September 2009

In spite of the present advances in the scaffolds fabrication and bioreactor systems, the ability to create functional thick tissue masses in vitro is still a great tissue engineering challenge. To overcome this problem, the fabrication of a capillary bed, for nutrient supply to and waste product removal from the tissue engineering construct as it grows, is essential. However, the technical construction of a capillary‐like architecture is complex and challenging. This study reports, for the very first time, a simple method to design and fabricate a porous hollow membrane sheet (PHMsh) to provide both a capillary bed and a scaffold to support tissue growth. The PHMsh composed of a flexible porous sheet involving parallel porous channels and can be used as flat‐, rolled‐, or sandwiched‐shape scaffold. The PHMsh was fabricated from poly(ϵ‐caprolactone) polymer solution using solvent casting methods (i.e., immersion precipitation and air casting). Optical microscopy and scanning electron microscopy were used for the morphological analyses. The PHMsh was surface treated using n‐hepthylamine plasma polymer (HApp) and X‐ray photoelectron spectroscopy confirmed successful surface coating. Human umbilical vein endothelial cells (HUVECs) and fibroblast cells were used to evaluate the capability of PHMsh toward cell adhesion. The HApp coating enhanced both HUVEC and fibroblast cells adhesion. The obtained preliminary results demonstrated the successful fabrication of the PHMsh, with potential application for tissue engineering scaffolds, particularly in large tissue mass generation under perfusion systems in vitro, which is our future research direction. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Generation of reactive oxygen species from porous silicon microparticles in cell culture medium
Authors: Low Suet Peng , Williams Keryn A. , Canham Leigh T. , Voelcker Nicolas H.
Published: September 2009

Nanostructured (porous) silicon is a promising biodegradable biomaterial, which is being intensively researched as a tissue engineering scaffold and drug‐delivery vehicle. Here, we tested the biocompatibility of non‐treated and thermally‐oxidized porous silicon particles using an indirect cell viability assay. Initial direct cell culture on porous silicon determined that human lens epithelial cells only poorly adhered to non‐treated porous silicon. Using an indirect cell culture assay, we found that non‐treated microparticles caused complete cell death, indicating that these particles generated a toxic product in cell culture medium. In contrast, thermally‐oxidized microparticles did not reduce cell viability significantly. We found evidence for the generation of reactive oxygen species (ROS) by means of the fluorescent probe 2′,7′‐dichlorofluorescin. Our results suggest that non‐treated porous silicon microparticles produced ROS, which interacted with the components of the cell culture medium, leading to the formation of cytotoxic species. Oxidation of porous silicon microparticles not only mitigated, but also abolished the toxic effects. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
PEGylation of interleukin‐10 for the mitigation of enhanced pain states
Authors: Soderquist Ryan G. , Milligan Erin D. , Harrison Jacqueline A. , Chavez Raymond A. , Johnson Kirk W. , Watkins Linda R. , Mahoney Melissa J.
Published: September 2009

The anti‐inflammatory cytokine interleukin‐10 (IL‐10) shows promise for the treatment of neuropathic pain, but for IL‐10 to be clinically useful as a short‐term therapeutic its duration needs to be improved. In this study, IL‐10 was covalently modified with polyethylene glycol (PEG) with the goal of stabilizing and increasing protein levels in the CSF to improve the efficacy of IL‐10 for treating neuropathic pain. Two different PEGylation methods were explored in vitro to identify suitable PEGylated IL‐10 products for subsequent in vivo testing. PEGylation of IL‐10 by acylation yielded a highly PEGylated product with a 35‐fold in vitro biological activity reduction. PEGylation of IL‐10 by reductive amination yielded products with a minimal number of PEG molecules attached and in vitro biological activity reductions of ∼3‐fold. In vivo collections of cerebrospinal fluid after intrathecal administration demonstrated that 20 kDa PEG attachment to IL‐10 increased the concentration of IL‐10 in the cerebrospinal fluid over time. Relative to unmodified IL‐10, the 20 kDa PEG‐IL‐10 product exhibited an increased therapeutic duration and magnitude in an animal model of neuropathic pain. This suggests that PEGylation is a viable strategy for the short‐term treatment or, in conjunction with other approaches, the long‐term treatment of enhanced pain states. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Imperfect hybrid layers created by an aggressive one‐step self‐etch adhesive in primary dentin are amendable to biomimetic remineralization in vitro
Authors: Kim Jongryul , Vaughn Ryan M. , Gu Lisha , Rockman Roy A. , Arola Dwayne D. , Schafer Tara E. , Choi Kyoung Kyu , Pashley David H. , Tay Franklin R.
Published: September 2009

Degradation of hybrid layers created in primary dentin occurs as early as 6 months in vivo. Biomimetic remineralization utilizes “bottom‐up” nanotechnology principles for interfibrillar and intrafibrillar remineralization of collagen matrices. This study examined whether imperfect hybrid layers created in primary dentin can be remineralized. Coronal dentin surfaces were prepared from extracted primary molars and bonded using Adper Prompt L‐Pop and a composite. One‐millimeter‐thick specimen slabs of the resin‐dentin interface were immersed in a Portland cement‐based remineralization medium that contained two biomimetic analogs to mimic the sequestration and templating functions of dentin noncollagenous proteins. Specimens were retrieved after 1–6 months. Confocal laser scanning microscopy was used for evaluating the permeability of hybrid layers to Rhodamine B. Transmission electron microscopy was used to examine the status of remineralization within hybrid layers. Remineralization at different locations of the hybrid layers corresponded with quenching of fluorescence within similar locations of those hybrid layers. Remineralization was predominantly intrafibrillar in nature as interfibrillar spaces were filled with adhesive resin. Biomimetic remineralization of imperfect hybrid layers in primary human dentin is a potential means for preserving bond integrity. The success of the current proof‐of‐concept, laterally diffusing remineralization protocol warrants development of a clinically applicable biomimetic remineralization delivery system. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Decrease in as‐needed sedative use by limiting nighttime sleep disruptions from hospital staff
Authors: Bartick Melissa C. , Thai Xia , Schmidt Timothy , Altaye Amsalework , Solet Jo M.
Published: September 2009

BACKGROUND:

Hospital routines frequently interrupt nighttime sleep. Sedatives promote sleep, but increase the risk of delirium and falls. Few interventional trials have studied sleep promotion in medical‐surgical units and little is known about its impact on sedative use.

OBJECTIVE:

To determine causes of sleep disruption, and assess whether decreasing sleep disruptions lowers sedative use in medical‐surgical patients.

DESIGN AND SETTING:

Interventional trial with historical controls on a medical‐surgical unit of a community teaching hospital. Nurses, physicians, and patients were blinded to the measurement of as‐needed sedative use.

PATIENTS:

Consecutive eligible adults (n = 161 preintervention patients, n = 106 intervention patients).

INTERVENTION:

We developed the “Somerville Protocol,” which included the establishment of an 8‐hour “Quiet Time” that began with automated lights‐off and lullaby; staff‐monitored noise; and avoidance of waking of patients for routine vital signs and medications.

MEASUREMENTS:

As‐needed sedative use, responses to a patient questionnaire, and responses to a modified Verran Snyder‐Halpern (VSH) sleep scale.

RESULTS:

Preintervention, “hospital staff “ was the disturbance most likely to keep patients awake. The intervention decreased the proportion of patients reporting it from 42% to 26%, a 38% reduction (P = 0.009; 95% confidence interval [CI]: 0.0452‐0.2765). Preintervention, 32% of patients received as‐needed sedatives, compared to 16% with the intervention, a 49% reduction (P = 0.0041; 95% CI: 0.056‐0.26), with a 62% decrease in patients over age 64 years (P = 0.005). VSH scores were unchanged.

CONCLUSIONS:

Small modifications in hospital routines, especially in the timing of vital signs and routine medication administration, can significantly reduce sedative use in unselected hospital patients. Journal of Hospital Medicine 2010. © 2010 Society of Hospital Medicine.
Statistical modelling in the investigation of stranger rape
Authors: ter Beek Mirjam , van den Eshof Paul , Mali Bas
Published: September 2009

A sample of stranger rape offences (n = 271) registered in the Dutch Violence Crime Linkage Analysis System database in the Netherlands between 1997 and 2007 was studied with the objective of developing statistical models, which give an indication of the probability of basic offender characteristics. Observable crime characteristics concerning the modus operandi, interaction between the offender and the victim, violence, precautionary measures, and sexual behaviours were selected in the dataset. Offender characteristics were selected based on their usefulness for the police organisation in narrowing the scope of a criminal investigation. Spatial behaviour, criminal history, and living situation of the offender were selected. From the predictive models, four out of five achieved a correct rate of over 70%, and all models predicted better than the best guess method. The proposed models for distance and prior convictions for violence seem particularly promising. Both these models show an improvement of correctly predicted offender characteristics of more than 20 percentile points compared with that which could have been estimated based on the average in the total sample. The predictive value of the models needs to be tested further with ‘new offences’, which were not used to construct the model. In general, the current study supports the finding that crime characteristics can be used to get an indication of the probability of certain offender characteristics. Nevertheless, for an understanding of the relationship between the crime characteristics and offender characteristics, a further development of a theoretical framework is urgently necessary. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and elucidation of deuterated vanillylamine hydrochloride and capsaicin
Authors: Kim Sang Wook , Park Jeong Hoon , Jung Soon Jae , Choi Tae Bum , Hur Min Goo , Yang Seung Dae , Yu Kook Hyun
Published: September 2009

Capsaicin is the major pungent component of hot peppers, which belong to the plant genus Capsicum. Although the biosynthesis of capsaicin is known to involve the condensation of vanillylamine and 8‐methylnonenoic acid by capsaicin synthase, the mechanism of biosynthesis is still not fully understood. In this study, deuterium labelled versions of capsaicin and the precursor vanillylamine were synthesized in order to investigate the biosynthesis of capsaicin in hot peppers. Copyright © 2009 John Wiley & Sons, Ltd.
Functional analysis of polyomavirus BK non‐coding control region quasispecies from kidney transplant recipients
Authors: Olsen Gunn‐Hege , Hirsch Hans H. , Rinaldo Christine Hanssen
Published: September 2009

Replication of the human polyomavirus BK (BKV) in renal tubular epithelial cells causes viruria and BKV‐nephropathy in kidney transplant recipients. Following prolonged high‐level BKV replication, rearrangement of the archetype non‐coding control region (NCCR) leads to a mixture of BKV variants. The aim of this study was to compare potential functional differences of 12 rearranged (rr)‐NCCR variants with the archetype (ww)‐NCCR (WWT) found in allograft biopsies or urine from three kidney transplant recipients including two with BKV‐nephropathy. Twelve different rr‐NCCRs and one archetype ww‐NCCR were inserted between the early and late protein coding region of BKV(Dunlop) to make recombinant BKV genomes for transfection into Vero cells. Immunoblotting, immunofluorescence staining, and quantitative PCR demonstrated that viral protein expression and extracellular BKV loads of 10 rr‐NCCR variants were similar or higher than observed for the ww‐NCCR BKV. Two rr‐NCCR variants (RH‐2 and RH‐19) were non‐functional. The functional rr‐NCCRs produced infectious progeny successfully infecting primary renal proximal tubular epithelial cells. The number of infected cells and extracellular BKV loads corresponded to the activity seen in Vero cells. Three rr‐NCCR variants (RH‐1, RH‐10, RH‐13) only gave rise to a few infected cells similar to ww‐NCCR, whereas seven variants had intermediate activity (RH‐5, RH‐6, RH‐8, RH‐9, RH‐11) or high replication activity (RH‐7 and RH‐18) with several hundred infected cells per well. The results indicate that both functional and non‐functional BKV rr‐NCCR variants arise during BKV replication in kidney transplant recipients and that most functional rr‐NCCR variants confer a higher replication capacity than archetype ww‐NCCR. J. Med. Virol. 81:1959–1967, 2009. © 2009 Wiley‐Liss, Inc.
Tracheal transplant with a prefabricated microsurgical flap
Authors: Icibaci Alexan , de Mello‐Filho Francisco Veríssimo
Published: September 2009

Objective:

To test the viability of a tracheal autotransplant, with an original technique using a prefabricated flap from a complete tracheal neovascularized segment (CTNVS) of the sternohyoid muscle anastomosed by a microsurgical technique.

Study Design:

An experimental study using dogs as an animal model.

Methods:

Ten mongrel dogs weighing 23 to 40 kg were divided into two groups: group I (control), five animals submitted to autotransplant of the CTNVS without a microsurgical vascular anastomosis; and group II, five dogs submitted to autotransplant of the CTNVS with a microsurgical vascular anastomosis.

Results:

All group I dogs developed respiratory insufficiency and died because of necrosis and stenosis of the autotransplanted CTNVS, whereas all group II dogs completed a minimum period of 90 days of observation without any clinical changes. Macro‐ and microscopic analysis revealed intact tracheal structures.

Conclusions:

The present clinical and morphological findings demonstrate that the CTNVS autotransplant is viable, when a microsurgical vascular anastomosis is used. Laryngoscope, 2009
Poly[ethylene‐co‐(vinyl alcohol)]‐graft‐poly(ε‐caprolactone) Synthesis by Reactive Extrusion, 1 ‐ Structural and Kinetic Study
Authors: Becquart Frédéric , Chalamet Yvan , Chen Jianding , Zhao Yanchao , Taha Mohamed
Published: September 2009

Chemical modification of EVOH in the molten state at 185 °C by a grafting from process of poly(ε‐caprolactone) in batch was studied. 1H NMR was used to characterize the structure evolutions of PCL grafts. In addition to grafting reactions, dynamic covalent transesterification reactions between EVOH residual alcohols and the polyester grafts led to a redistribution of the PCL grafts length. $\mathop {\overline {Dp} }\nolimits_n $ up to 27 and SR up to 80% were obtained. Experiments made in a corotating mini twin‐screw extruder also confirmed these results. The effect of the alcohol to caprolactone ratio and catalyst concentration (SnOct2) on kinetic evolution showed that few minutes were necessary to complete the polymerization. A kinetic model was proposed and adequate conditions for the synthesis by reactive extrusion were defined.

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