bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical outcomes of ileorectal anastomosis for ulcerative colitis
Authors: da Luz Moreira A , Kiran R P , Lavery I 
Published: December 2009

Abstract

Background
The aim of this study was to determine the fate of the rectum, functional results and quality of life after ileorectal anastomosis (IRA) in ulcerative colitis.

Methods
Patients with ulcerative colitis and indeterminate colitis who underwent IRA from 1971 to 2006 were evaluated retrospectively. Twenty-two patients with an IRA were matched by age, sex and follow-up duration with 66 patients with an ileal pouch–anal anastomosis (IPAA) and compared for functional outcomes and quality of life.

Results
Eighty-six patients with an IRA were included. Median follow-up was 9 (range 1–36) years. Rectal dysplasia and cancer rates were 17 and 8 per cent respectively. The rectum was resected in 46 patients (53 per cent) because of refractory proctitis in 24, rectal dysplasia in 15 and rectal cancer in seven. The cumulative probability of having a functioning IRA at 10 and 20 years was 74 and 46 per cent respectively. Patients with an IRA had fewer bowel movements (P = 0·020) and less night-time seepage (P = 0·020) but increased urgency (P &lt; 0·001) compared with patients with an IPAA, whereas quality of life was similar.

Conclusion
In selected patients with ulcerative colitis IRA gives an acceptable quality of life and functional outcome that are comparable to those in patients with an IPAA. Owing to the risk of cancer, surveillance of the rectum is mandatory.
Biomimetic Formation of 2‐Tropolones by Dioxygenase‐Catalysed Ring Expansion of Substituted 2,4‐Cyclohexadienones
Authors: Xin Meite , Bugg Timothy D. H. 
Published: December 2009

AbstractSubstituted 2‐tropolone natural products are found in plants and fungi. Their biosynthesis is thought to occur by ring expansion from a cyclohexadienone precursor, but this reaction has not previously been demonstrated experimentally. Treatment of 6‐hydroxy‐6‐hydroxymethylcyclohexa‐2,4‐dienone with the non‐haem iron(II)‐dependent extradiol catechol dioxygenase MhpB from Escherichia coli results in the formation of the 2‐tropolone ring‐expansion product through a pinacol‐type rearrangement. Three further substituted cyclohexa‐2,4‐dienone analogues were prepared, and treatment of each analogue was found to give the substituted 2‐tropolone ring‐expansion product. This ring expansion could also be effected nonenzymatically by treatment with 1,4,7‐triazacyclononane and FeCl2. This is a novel transformation for non‐haem iron‐dependent enzymes, and this is the first experimental demonstration of the proposed ring‐expansion reaction in tropolone biosynthesis.
Efficient Aerobic Wacker Oxidation of Styrenes Using Palladium Bis(isonitrile) Catalysts
Authors: Naik Anu , Meina Liu , Zabel Manfred , Reiser Oliver 
Published: December 2009

AbstractThe palladium‐catalyzed aerobic oxidation of alkenes and especially styrenes (Wacker oxidation) by using chiral pseudo C2‐symmetrical bis(isonitrile) ligands in the absence of further cocatalysts gives rise to methyl ketones in a highly chemoselective manner. The palladium bis(isonitrile) catalyst was characterized by NMR spectroscopy and X‐ray structure analysis, revealing a dissymmetric coordination of palladium by the two isonitrile moieties.
Highly Enantioselective Synthesis of β‐Heteroaryl‐Substituted Dihydrochalcones Through Friedel–Crafts Alkylation of Indoles and Pyrrole
Authors: Wang Wentao , Liu Xiaohua , Cao Weidi , Wang Jun , Lin Lili , Feng Xiaoming 
Published: December 2009

AbstractA highly enantioselective Friedel–Crafts (F–C) alkylation of indoles and pyrrole with chalcone derivatives catalyzed by a chiral N,N′‐dioxide–Sc(OTf)3 complex has been developed that tolerates a wide range of substrates. The reaction proceeds in moderate to excellent yields and high enantioselectivities (85–92 % enantiomeric excess) using 2 mol % (for indole) or 0.5 mol % (for pyrrole) catalyst loading, which showed the potential value of the catalyst system. Meanwhile, a strong positive nonlinear effect was observed. On the basis of the experimental results and previous reports, a possible working model is proposed to explain the origin of the activation and asymmetric induction.
Axially chiral N‐(o‐aryl)‐4‐hydroxy‐2‐oxazolidinone derivatives from diastereoselective reduction of N‐(o‐aryl)‐2,4‐oxazolidinediones: Thermally interconvertible atropisomers via ring‐chain‐ring tautomerization
Authors: Demir‐Ordu Öznur , Doǧan İlknur 
Published: December 2009

AbstractThe reduction of the axially chiral N‐(o‐aryl)‐5,5‐dimethyl‐2,4‐oxazolidinediones by NaBH4 yielded axially chiral N‐(o‐aryl)‐4‐hydroxy‐5,5‐dimethyl‐2‐oxazolidinone enantiomers having a chiral center at C‐4, with 100% diastereoselectivity as has been shown by their 1H and 13C NMR spectra and by enantioselective HPLC analysis. The resolved enantiomeric isomers were found to interconvert thermally through an aldehyde intermediate formed upon ring cleavage via a latent ring‐chain‐ring tautomerization. It was found that the rate of enantiomerization depended on the size and the electronic effect of the ortho substituent present on the aryl ring bonded to the nitrogen of the heterocycle. Chirality 2010. © 2009 Wiley‐Liss, Inc.
Alignment of Carbon Nanotubes in Thermotropic and Lyotropic Liquid Crystals
Authors: Scalia Giusy 
Published: December 2009

AbstractThe organization of carbon nanotubes is an important but challenging issue. This Minireview focuses on a novel approach based on the use of liquid crystals as host for nanotube dispersion and ordering. With these self‐organizing fluids it is possible to control the nanotube orientation on a macroscopic scale, as the orientational order of the liquid crystal, the direction of which can easily be selected and dynamically modulated, is transferred onto embedded carbon nanotubes. Both main classes of liquid crystals, thermotropics and lyotropics, have been used successfully. This reveals an aligning mechanism resulting from the liquid crystallinity per se, independent of specific molecular structures, although these can affect the degree of order and the quality of the tube dispersion. The enormous variety of systems that form liquid crystalline phases provides additional strength and potentialities to the liquid‐crystal‐based route towards nanotube alignment. The exploration of this new use of liquid crystals has just started, hence we can expect exciting developments in the years to come.
Neuroanatomical basis for therapeutic applications of cannabinoid receptor 1 antagonists
Authors: Thomas Brian F. 
Published: December 2009

AbstractThe CB1 receptor is a Class A G‐protein coupled receptor that has a high density and widespread distribution within the central nervous system. Because of its neuroanatomical distribution, the endocannabinoid system can modulate a wide variety of psychological and physiological functions. For example, CB1 receptors are found in brain regions regulating motor activity, cognitive processes, pain, satiety, appetitive behaviors and reward. In correspondence with this distribution, modulation of the endocannabinoid system has been shown to produce changes in coordination, executive function, memory, mood, perception, wakefulness, nociception and appetite. Administration of cannabinoid agonists has also been therapeutically used to reduce nausea, and is also known to decrease body temperature and neuronal excitability, pointing to additional roles for endocannabinoids in these and other physiological/neurological processes. The ongoing elucidation and characterization of the neuroanatomical circuitry within which the CB1 cannabinoid receptor and endocannabinoids are localized to modulate these psychological and physiological processes continues to suggest therapeutic applications for cannabinoid antagonists and inverse agonists. Drug Dev Res 70:527–554, 2009. © 2009 Wiley‐Liss, Inc.
Construction of simulation model for spray flash desalination system
Authors: Goto Satoru , Yamamoto Yuji , Sugi Takenao , Yasunaga Takeshi , Ikegami Yasuyuki , Nakamura Masatoshi 
Published: December 2009

AbstractThis paper describes a simulation model for a spray flash desalination system which makes fresh water from sea water by using the temperature difference between warm surface sea water and cool deep sea water. The spray flash desalination system can be modeled by using the energy conservation law and the mass conservation law. Simulation results of the model are compared with the experimental results and show the accuracy of the proposed simulation model. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 9–17, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20975
1‐D‐Tin(II) Phenylchalcogenolato Complexes ∞1[Sn(EPh)2] (E = S, Se, Te) – Synthesis, Structures, Quantum Chemical Studies and Thermal Behaviour
Authors: Eichhöfer Andreas , Jiang Ji‐Jun , Sommer Heino , Weigend Florian , Fuhr Olaf , Fenske Dieter , Su Cheng‐Yong , Buth Gernot 
Published: December 2009

AbstractA series of three 1‐D‐tin(II) phenylchalcogenolato complexes ∞1[Sn(EPh)2] (E = S, Se, Te) were synthesized in yields > 80 % by reaction of SnCl2 with two equivalents of PhESiMe3 in organic solvents. In the crystal the molecules form two different types of one‐dimensional chains. In ∞1[Sn(SPh)2] the tin atoms are distorted trigonal pyramidal coordinated by sulfur atoms (two bonds within a monomer and one longer bond between neighbored monomers), while in ∞1[Sn(EPh)2] (E = Se, Te) the tin atoms show contacts to two neighbored monomers leading to a fourfold coordination of the tin atoms by either selenium or tellurium atoms. The bond situation is discussed on the basis of density functional calculations. Thermal treatment mostly leads to the formation of the corresponding phase pure tin(II) chalcogenides however sublimation plays an increasing role ongoing from the tellurolato to the thiolato complex especially for the use of vacuum conditions. The investigation of the volatile cleavage products reveals the occurence of more complex reactions in the gas phase than the formal stoichiometric cleavage of EPh2 (E = S, Se, Te) with formation of SnE.
Hydrogen and Halogen Bonding in the Crystal Structure of a 1,3,5‐Substituted 2,4,6‐Triethylbenzene Consisting of Three Phenanthroline Units
Authors: Mazik Monika , Hartmann Andrè , Jones Peter G. 
Published: December 2009

Abstract1,3,5‐Tris‐[N‐(1,10‐phenanthrolin‐2‐yl‐carbonyl)aminomethyl]‐2,4,6‐triethylbenzene (1) was synthesized and its crystal structure was examined. X‐ray structural analysis revealed the presence of hydrogen‐bonded water molecules as well as hydrogen‐ and halogen‐bonded chloroform molecules in the crystal structure of 1. The 1·H2O·CHCl3 associate is stabilized by N–H···O, O–H···N, O–H···O, C–H···O, and C–H···Cl hydrogen bonds as well as C–Cl···O, C–Cl···π, and C–Cl···Cl interactions. Particularly short C–H···O hydrogen bonds with H···O and C···O distances of 1.89 and 2.94 Å, respectively, are observed in the crystal structure. The H···O distance is approximately 30 % shorter than the sum of the van der Waals radii of involved atoms.
New Colours for Carotenoids – Synthesis of Pyran Polyenes
Authors: Øpstad Christer L. , Sliwka Hans‐Richard , Partali Vassilia 
Published: December 2009

AbstractA new type of carotenoid has been synthesized with a 2H‐pyran ring placed in the polyene chain. This compound was successively elongated by Wittig reactions. The pyran‐carotenoids obtained show a significant increased λmax compared with carotenoids lacking the pyran ring. A further remarkable bathochromic shift was observed upon protonation to pyranium‐carotenoids. The pyranium ring is the distinctive feature of anthocyanidin dyes and has now become an internal part of carotenoids.
Graft linker immobilization for spatial control of protein immobilization inside fused microchips
Authors: Shirai Kentaro , Renberg Björn , Sato Kae , Mawatari Kazuma , Konno Tomohiro , Ishihara Kazuhiko , Kitamori Takehiko 
Published: December 2009

AbstractFused silica glass microchips have several attractive features for lab‐on‐a‐chip applications; they can be machined with excellent precision down to nanospace; are stable; transparent and can be modified with a range of silanization agents to change channel surface properties. For immobilization, however, ligands must be added after bonding, since the harsh bonding conditions using heat or hydrofluoric acid would remove all prior immobilized ligands. For spatial control over immobilization, UV‐mediated immobilization offers several advantages; spots can be created in parallel, the feature size can be made small, and spatial control over patterns and positions is excellent. However, UV sensitive groups are often based on hydrophobic chemical moieties, which unfortunately result in greater non‐specific binding of biomolecules, especially proteins. Here, we present techniques in which any –CHx (x=1,2,3) containing surface coating can be used as foundation for grafting a hydrophilic linker with a chemical anchor, a carboxyl group, to which proteins and amine containing molecules can be covalently coupled. Hence, the attractive features of many well‐known protein and biomolecule repelling polymer coatings can be utilized while achieving site‐specific immobilization only to pre‐determined areas within the bonded microchips.
Dry film microchips for miniaturised separations
Authors: Guijt Rosanne M. , Candish Esme , Breadmore Michael C. 
Published: December 2009

AbstractIn this work microfluidic devices were made from the dry film photoresist Ordyl SY330, characterised by optical and electron microscopy and used for electrophoretic separations. A simple and fast microfabrication process was developed for the fabrication of channels that are 50 μm wide and 30 μm in height, requiring only the use of an office laminator, a hot plate, an exposure source and mask and an electric drill to make four microdevices in less than 1 h. The optical properties of the photoresist were studied and the resist showed significant absorbance below 370 nm and 570–630 nm, and had an optical transmission of 80% between 400 and 550 nm. Fluorescence emission over the region of maximum transmission was low allowing these devices to be used for fluorescence detection at 488/512 nm. Electrophoretic separation of APTS and three derivatised sugars was performed in 20 mM phosphate buffer, pH 2.5 with efficiencies of the three sugars of 40 000 plates (2 100 000 plates/m) within 30 s at a field strength of 500 V/cm. The simple fabrication process also allowed microchannels to be easily filled with chromatography particles before sealing, avoiding the challenging task of slurry packing, and the potential of these devices for liquid chromatography was demonstrated by the extraction of fluorescein onto anion exchange particles.
Evaluation of microchip material and surface treatment options for IEF of allergenic milk proteins on microchips
Authors: Poitevin Martine , Shakalisava Yuliya , Miserere Sandrine , Peltre Gabriel , Viovy Jean‐Louis , Descroix Stephanie 
Published: December 2009

AbstractThe use of glass and PDMS microchips has been investigated to perform rapid and efficient separation of allergenic whey proteins by IEF. To decrease EOF and to limit protein adsorption, two coating procedures have been compared. The first one consists in immobilizing hydroxypropyl cellulose (HPC) and the second one poly(dimethylacrylamide‐co‐allyl glycidyl ether) (PDMA‐AGE). EOF limitation has been evaluated using frontal electrophoresis of a fluorescent marker of known effective mobility. EOF velocity was decreased by a factor about 100 and 30, respectively. pH gradient formation has been evaluated for each microchip using fluorescent pI markers. It was demonstrated that as expected a coating was essential to avoid pH gradient drift. Both coatings were efficient on glass microchips, but only PDMA‐AGE allowed satisfying focusing of pI markers on PDMS microchips. Fluorescent covalent and noncovalent labelings of milk proteins have been compared by IEF on slab‐gels. IEF separation of three major allergenic whey proteins [β‐lactoglobulin A (pI 5.25) and B (pI 5.35) and α‐lactalbumin (pI 4.2–4.5)] was performed in both microchips. Milk proteins were separated with better resolution and shorter analysis time than by classical CIEF. Finally, better resolutions for milk allergens separation were obtained on glass microchips.
A microfluidic device for characterizing the invasion of cancer cells in 3‐D matrix
Authors: Liu Tingjiao , Li Chunyu , Li Hongjing , Zeng Shaojiang , Qin Jianhua , Lin Bingcheng 
Published: December 2009

AbstractA microfluidic device was developed for the study of directed invasion of cancer cells in 3‐D matrix with concentration gradient. This device consists of two parallel perfusion channels connected by two cell culture chambers. To mimic extracellular matrix (ECM), gelled basement membrane extract (BME) was used to support 3‐D distribution of breast cancer cells (MCF7) in cell culture chambers. A stable linear concentration gradient of epidermal growth factor (EGF) was generated across the chambers by continuous perfusion. Using the device, we investigated MCF7 cell invasion induced by different concentrations of EGF in 3‐D matrix. It was found that cancer cells responded to EGF stimulation with forming cellular protrusions and migrating towards high EGF concentration. We further investigated the anti‐invasion effect of GM 6001, a matrix metalloproteinase inhibitor. We identified that matrix metalloproteinase inhibition repressed both cellular protrusion formation and cell migration in 3‐D matrix. These findings suggest that EGF is able to induce MCF7 cell invasion in 3‐D extracellular matrix and this effect is dependent on proteolytic activity. This device is relatively simple to construct and operate. It should be a useful platform for elucidating the mechanism of cancer invasion and screening anti‐invasion drugs for cancer therapy.
Microchip CGE linked to immunoprecipitation as an alternative to Western blotting
Authors: Wenz Christian , Rüfer Andreas 
Published: December 2009

AbstractA novel approach for protein identification is presented, which combines the specificity of an immunoprecipitation approach with the sensitivity of protein detection in microchip CGE. This method involves derivatization of the sample proteins with a fluorescent dye, target protein isolation with specific antibodies and Protein A coated magnetic beads, and automated sizing and quantification of the eluted samples on microchips. The performance of the new technique was demonstrated with glutathion‐S‐transferase‐ and polyHistidine‐tagged target proteins in an Escherichia coli background. A specific detection of target proteins was possible down to 0.001% or 1 ng target protein in a background of 100 μg E. coli protein. With this approach, proteins ranging from 10 to 220 kDa could be identified with a panel of different target‐specific antibodies. The reproducibility of the method was very similar to standard microchip CGE methods. In a direct comparison to Western blotting, a similar sensitivity and specificity of both techniques was observed. However, the new approach compares favorably to Western blotting in terms of time‐to‐result, usability and labor intensity, antibody consumption and access to quantitative data.
DNA manipulation by means of insulator‐based dielectrophoresis employing direct current electric fields
Authors: Gallo‐Villanueva Roberto C. , Rodríguez‐López Carlos E. , Díaz‐de‐la‐Garza Rocío I. , Reyes‐Betanzo Claudia , Lapizco‐Encinas Blanca H. 
Published: December 2009

AbstractElectrokinetic techniques offer a great potential for biological particle manipulation. Among these, dielectrophoresis (DEP) has been successfully utilized for the concentration of bioparticles. Traditionally, DEP is performed employing microelectrodes, an approach with attractive characteristics but expensive due to microelectrode fabrication costs. An alternative is insulator‐based DEP, a method where non‐uniform electric fields are created with arrays of insulating structures. This study presents the concentration of linear DNA particles (pET28b) employing a microchannel, with an array of cylindrical insulating structures and direct current electric fields. Results showed manipulation of DNA particles with a combination of electroosmotic, electrophoretic, and dielectrophoretic forces. Employing suspending media with conductivity of 104 μS/cm and pH of 11.15, under applied fields between 500 and 1500 V/cm, DNA particles were observed to be immobilized due to negative dielectrophoretic trapping. The observation of DNA aggregates that occurred at higher applied fields, and dispersed once the field was removed is also included. Finally, concentration factors varying from 8 to 24 times the feed concentration were measured at 2000 V/cm after concentration time‐periods of 20–40 s. The results presented here demonstrate the potential of insulator‐based DEP for DNA concentration, and open the possibility for fast DNA manipulation for laboratory and large‐scale applications.
Temperature gradient focusing in miniaturized free‐flow electrophoresis devices
Authors: Becker Marco , Mansouri Abraham , Beilein Cornelia , Janasek Dirk 
Published: December 2009

AbstractTemperature gradient focusing is a method to separate and focus any charged analytes even without accessible isoelectric point, and has been already widely used in CE. In this paper, we demonstrate the application of temperature gradient focusing to free‐flow electrophoresis. Besides focusing and separation experiments of proteins, the stability of the temperature gradient under flow conditions and the temperature dependence of fluorescence dyes have also been investigated.
Comparing polyelectrolyte multilayer‐coated PMMA microfluidic devices and glass microchips for electrophoretic separations
Authors: Currie Christa A. , Shim Joon Sub , Lee Se Hwan , Ahn Chong , Limbach Patrick A. , Halsall H. Brian , Heineman William R. 
Published: December 2009

AbstractThere is a continuing drive in microfluidics to transfer microchip systems from the more expensive glass microchips to cheaper polymer microchips. Here, we investigate using polyelectrolyte multilayers (PEM) as a coating system for PMMA microchips to improve their functionality. The multilayer system was prepared by layer‐to‐layer deposition of poly(diallyldimethylammonium) chloride and polystyrene sulfonate. Practical aspects of coating PMMA microchips were explored. The multilayer buildup process was monitored using EOF measurements, and the stability of the PEM was investigated. The performance of the PEM‐PMMA microchip was compared with those of a standard glass microchip and a PEM‐glass microchip in terms of EOF and separating two fluorescent dyes. Several key findings in the development of the multilayer coating procedure for PMMA chips are also presented. It was found that, with careful preparation, a PEM‐PMMA microchip can be prepared that has properties comparable – and in some cases superior – to those of a standard glass microchip.