bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitric oxide synthase in critically ischaemic muscle and alterations in isoform expression during revascularization surgery
Authors: Tsui J C S , Baker D M , Shaw S G , Shi-Wen X , Dashwood M R 
Published: September 2007

Abstract

Background
Dysfunction of the nitric oxide pathway is implicated in peripheral arterial disease. Nitric oxide synthase (NOS) isoforms and NOS activity were studied in muscle from patients with critical leg ischaemia (CLI). Alterations in NOS during revascularization surgery were also assessed.

Methods
Muscle biopsies were taken from patients with CLI undergoing amputation and also from patients undergoing femorodistal bypass at the start of surgery, after arterial clamping and following reperfusion. The presence of NOS within muscle sections was confirmed using reduced nicotinamide adenine dinucleotide phosphate diaphorase histochemistry. NOS isoform distribution was studied by immunohistochemistry. NOS mRNA and protein levels were measured using real-time reverse transcriptase–polymerase chain reaction and western blotting. NOS activity was assessed with the citrulline assay.

Results
All three NOS isoforms were found in muscle, associated with muscle fibres and microvessels. NOS I and III protein expression was increased in CLI (P = 0·041). During revascularization, further ischaemia and reperfusion led to a rise in NOS III protein levels (P = 0·008). NOS activity was unchanged.

Conclusion
Alterations in NOS I and III occurred in muscle from patients with CLI and further changes occurred during bypass surgery.
Late gastrointestinal disorders after rectal cancer surgery with and without preoperative radiation therapy
Authors: Birgisson H , Påhlman L , Gunnarsson U , Glimelius B 
Published: September 2007

Abstract

Background
The aim of the study was to analyse late gastrointestinal disorders necessitating hospital admission following rectal cancer surgery and to determine their relationship to preoperative radiation therapy.

Methods
Curatively treated patients participating in the Swedish Rectal Cancer Trial during 1987–1990, randomized to preoperative irradiation (454 patients) or surgery alone (454), were matched against the Swedish Hospital Discharge Registry. Hospital records for patients admitted with gastrointestinal diagnoses were reviewed.

Results
Irradiated patients had an increased relative risk (RR) of late small bowel obstruction (RR 2·49 (95 per cent confidence interval (c.i.) 1·48 to 4·19)) and abdominal pain (RR 2·09 (95 per cent c.i. 1·03 to 4·24)) compared with patients treated by surgery alone. The risk of late small bowel obstruction requiring surgery was greatly increased (RR 7·42 (95 per cent c.i. 2·23 to 24·66)). Irradiated patients with postoperative anastomotic leakage were at increased risk for late small bowel obstruction (RR 2·99 (95 per cent c.i. 1·07 to 8·31)). The risk of small bowel obstruction was also related to the radiation technique and energy used.

Conclusion
Small bowel obstruction is more common in patients with rectal cancer treated with preoperative radiation therapy.
Acoustic chemometrics of complex natural systems: flume test rig feasibility studies for monitoring river bed‐load sediment transportation processes
Authors: Esbensen Kim H. , Ade Premus K. , Zuta John F. , Bogen Jim , Møen Knut 
Published: September 2007

AbstractA feasibility study has been carried out on a meso‐scale experimental flume rig with the objective of developing a robust acoustic chemometrics facility of bed‐load mass flux quantification for deployment in rivers and hydroelectric power plant inlet canal systems. The test rig is equipped with an acoustic sensor attached to a steel plate flush with the flume bottom, reproducing natural sedimentary river bed‐load transportation characteristics. Sensor signals were preprocessed by the Fast Fourier Transform (FFT) and subjected to multivariate calibration (PLS1 regression), enabling prediction of sediment bed‐load transport interacting with varying sedimentary characteristics. Based on a comprehensive experimental design on two major factors (F1: mass flux; F2: grain‐size distribution), it is concluded that reliable, test set validated PLS‐prediction models can be established for bed‐load mass fluxes with effective compensation for widely varying sediment size. The main models developed display average relative prediction errors (RMSEP) spanning 4.8–13.2%; the highest errors reflect scenarios modelling for seven non‐overlapping size fraction ranges simultaneously. All real‐world river implementations will experience significantly less varied sediment variability than this worst case scenario, thus realistic models will be characterised by relative RMSEP of some 10% or lower, highly satisfactory for such complex natural systems. All results, interpretations and conclusions reached in the present study are based on the most stringent test set validation protocol. The specific acoustic impact on the sensor plate by sediments characterised by different grain‐size distributions must be expected to lead to significant interaction with the mass flux signals. The experimental design was therefore deployed as a full two‐factor design (7 and 8 levels, respectively), totaling 2 × 56 runs (calibration and test set). Because of a very high sensitivity to the specific time‐varying transportation regimen over the river bottom (successfully duplicated on the flume rig bottom), conventional cross‐validation of a single training set model predicting sediment mass flux runs a high risk of being over‐optimistic, unable to produce a realistic prediction performance assessment. Only true test set validation—an independent second set of all runs in the design covering the same experimental space as the training data—can substantiate a realiable, scientifically acceptable prediction performance validation. This setup allows practical evaluation of the relative merits of cross‐validation versus test set validation in situations in which there is a significant complement of sampling, analysis and measurement errors in both [X,Y] data. Copyright © 2007 John Wiley & Sons, Ltd.
Unusual Coexistence of Magnetic and Nonmagnetic Mo6 Octahedral Clusters in a Chalcohalide Solid Solution: Synthesis, X‐ray Diffraction, EPR, and DFT Investigations of Cs3Mo6Ii6Ii2−xSeixIa6
Authors: Kirakci Kaplan , Cordier Stéphane , Shames Alex , Fontaine Bruno , Hernandez Olivier , Furet Eric , Halet Jean‐François , Gautier Régis , Perrin Christiane 
Published: September 2007

AbstractThe Cs3Mo6Ii6Ii2−xSeixIa6 series has been obtained by a solid‐state route. There is evidence for a solid solution between the compositions Cs3Mo6Ii6Ii0.8Sei1.2Ia6 and Cs3Mo6Ii6Ii0.4Sei1.6Ia6 (space group: R$\bar 3$c, Z=6; a=16.7065(4), c=20.5523(4) Å, V=4967.8(2) Å3 and a=16.6354(3), c=20.5444(4) Å, V=4923.7(2) Å3, respectively). The structure of this new series is based on magnetic [Mo6Ii6Sei2Ia6]3− and diamagnetic [Mo6Ii7SeiIa6]3− units with 23 and 24 valence electrons per Mo6 cluster, respectively. For a particular x, the structure of Cs3Mo6Ii6Ii2−xSexIa6 is based on a mixture of (x−1) [Mo6Ii6Sei2Ia6]3− with (2−x) [Mo6Ii7SeiIa6]3−. This leads to an average [Mo6Ii6Ii2−xSexIa6]3− ionic unit deduced from single‐crystal X‐ray diffraction investigations. The two inner positions of the average face‐capped [Mo6Ii8−xSeixIa6]3− ionic units (located on the threefold axis of the unit) are randomly occupied by iodine and selenium, whereas the other ligand positions are fully occupied by iodine. Low‐temperature electron paramagnetic resonance (EPR) studies reveal a signal split into two components with g∥>g⊥. The reciprocal double integration intensity of the EPR signal versus T graph reveals a typical Curie law behavior. A density functional theory (DFT) study indicates that occupation of the inner position on the threefold axis by selenium atoms is preferred energetically among the three possible distributions of selenium atoms. The comparison of experimental and theoretical g values confirms the crystallographic analysis and agrees with the axial elongation of the Mo6 cluster within the crystal structure.
Bis[bis‐(4‐alkoxyphenyl)amino] Derivatives of Dithienylethene, Bithiophene, Dithienothiophene and Dithienopyrrole: Palladium‐Catalysed Synthesis and Highly Delocalised Radical Cations
Authors: Odom Susan A. , Lancaster Kelly , Beverina Luca , Lefler Kelly M. , Thompson Natalie J. , Coropceanu Veaceslav , Brédas Jean‐Luc , Marder Seth R. , Barlow Stephen 
Published: September 2007

AbstractFive diamines with thiophene‐based bridges—(E)‐1,2‐bis{5‐[bis(4‐butoxyphenyl)amino]‐2‐thienyl}ethylene (1), 5,5′‐bis[bis(4‐methoxyphenyl)amino]‐2,2′‐bithiophene (2), 2,6‐bis[bis(4‐butoxyphenyl)amino]dithieno[3,2‐b:2′,3′‐d]thiophene (3), N‐(4‐tert‐butylphenyl)‐2,6‐bis[bis(4‐methoxyphenyl)amino]dithieno[3,2‐b:2′,3′‐d]pyrrole (4 a) and N‐tert‐butyl‐2,6‐bis[bis(4‐methoxyphenyl)amino]dithieno[3,2‐b:2′,3′‐d]pyrrole (4 b)—have been synthesised. The syntheses make use of the palladium(0)‐catalysed coupling of brominated thiophene species with diarylamines, in some cases accelerated by microwave irradiation. The molecules all undergo facile oxidation, 4 b being the most readily oxidised at about −0.4 V versus ferrocenium/ferrocene, and solutions of the corresponding radical cations were generated by addition of tris(4‐bromophenyl)aminium hexachloroantimonate to the neutral species. The near‐IR spectra of the radical cations show absorptions characteristic of symmetrical delocalised species (that is, class III mixed‐valence species); analysis of these absorptions in the framework of Hush theory indicates strong coupling between the two amine redox centres, stronger than that observed in species with phenylene‐based bridging groups of comparable length. The strong coupling can be attributed to high‐lying orbitals of the thiophene‐based bridging units. ESR spectroscopy indicates that the coupling constant to the amino nitrogen atoms is somewhat reduced relative to that in a stilbene‐bridged analogue. The neutral species and the corresponding radical cations have been studied with the aid of density functional theory and time‐dependent density functional theory. The DFT‐calculated ESR parameters are in good agreement with experiment, while calculated spin densities suggest increased bridge character to the oxidation in these species relative to that in comparable species with phenylene‐based bridges.
Vesicles of a New Salt‐Free Cat‐anionic Fluoro/Hydrocarbon Surfactant System
Authors: Li Xin , Dong Shuli , Jia Xiangfeng , Song Aixin , Hao Jingcheng 
Published: September 2007

AbstractWeakly basic tetradecyldimethylaminoxide (C14DMAO) molecules can be protonated to form a cationic surfactant, C14DMAOH+, by an acidic fluorocarbon surfactant, an 8‐2‐fluorotelomer unsaturated acid (C7F15CFCHCOOH), to form a salt‐free cationic and anionic (cat‐anionic) fluoro/hydrocarbon surfactant system in aqueous solution. The high Krafft point of C7F15CFCHCOOH was largely reduced as a result of being mixed with a C14DMAO micelle solution. A study of the phase behavior of the new salt‐free cat‐anionic fluoro/hydrocarbon surfactant system clearly indicates the existence of a birefringent Lα‐phase region at (25.0±0.1) °C. The birefringent Lα phase consists of vesicles, which include uni‐ and multilamellar vesicles with one to dozens of shells, and oligovesicular vesicles, as demonstrated by freeze‐fracture and cryo‐transmission electron microscopy (FF‐ and cryo‐TEM) images. The size distribution and structural transitions in the salt‐free cat‐anionic fluoro/hydrocarbon surfactant system were studied by dynamic light scattering (DLS) and 1H and 19F NMR spectroscopy. The formation of a salt‐free cat‐anionic vesicle phase could be induced by the strong electrostatic interaction between the cationic hydrocarbon C14DMAOH+ and the anionic fluorocarbon C7F15CFCHCOO−, which provided evidence that the electrostatic interaction between the cationic and anionic surfactants is larger than the nonsynergistic interaction between the stiff fluorocarbon and the soft hydrocarbon chains of the surfactants.
A Convergent Pd‐Catalyzed Asymmetric Allylic Alkylation of dl‐ and meso‐Divinylethylene Carbonate: Enantioselective Synthesis of (+)‐Australine Hydrochloride and Formal Synthesis of Isoaltholactone
Authors: Trost Barry M. , Aponick Aaron , Stanzl Benjamin N. 
Published: September 2007

AbstractThe use of a mixture of dl‐ and meso‐divinylethylene carbonate as an electrophile in palladium‐catalyzed asymmetric allylic alkylation reactions is reported. From the diastereomeric mixture of meso and chiral racemic starting materials, a single product is obtained in high optical purity employing either oxygen or nitrogen nucleophiles. The resulting dienes have proven to be versatile synthetic intermediates as each carbon is functionalized for further transformation and differentiated by virtue of the reaction. A mechanism for this intriguing transformation is proposed and a concise enantioselective total synthesis of (+)‐australine hydrochloride is reported as well as a formal synthesis of isoaltholactone.
Electronic Structures of Five‐Coordinate Complexes of Iron Containing Zero, One, or Two π‐Radical Ligands: A Broken‐Symmetry Density Functional Theoretical Study
Authors: Chłopek Krzysztof , Muresan Nicoleta , Neese Frank , Wieghardt Karl 
Published: September 2007

AbstractThe electronic structures of a series of five‐coordinate complexes of iron containing zero, one, or two bidentate, organic π‐radical ligands and a monodentate ligand (pyridine, iodide) have been studied by broken‐symmetry (BS) density functional theoretical (DFT) methods. By analyzing the set of corresponding orbitals5 (CO) a convenient division of the spin‐up and spin‐down orbitals into 1) essentially doubly‐occupied molecular orbitals (MO), 2) exactly singly‐occupied MOs, 3) spin‐coupled pairs, and 4) virtual orbitals can be achieved and a clear picture of the spin coupling between the ligands (non‐innocence vs. innocence) and the central metal ion (dN configuration) can be generated. We have identified three classes of complexes which all contain a ferric ion (d5) with an intrinsic intermediate spin (SFe= 3/2) that yield 1) an St=3/2 ground spin state if the two bidentate ligands are closed‐shell species (innocent ligands); 2) if one π‐radical ligand is present, an St=1 ground state is obtained through intramolecular antiferromagnetic coupling; 3) if two such radicals are present, an St=1/2 ground state is obtained. We show unambiguously for the first time that the pentane‐2,4‐dione‐bis(S‐alkylisothiosemicarbazonato) ligand can bind as π‐radical dianion (L.TSC)2− in [FeIII(L.TSC)I] (St=1) (6); the description as [FeIV(LTSC3−)I] is incorrect. Similarly, the diamagnetic monoanion in 14 must be described as [FeIII(CN)2(L.TSC)]− (St=0) with a low‐spin ferric ion (d5, SFe=1/2) coupled antiferromagnetically to a π‐radical ligand; [FeII(CN)2(LTSC−)]− is an incorrect description.
Intermediates in the Destruction of Chlorinated C1 Hydrocarbons on La‐Based Materials: Mechanistic Implications
Authors: van der Heijden Alwies W. A. M. , Garcia Ramos Maria , Weckhuysen Bert M. 
Published: September 2007

AbstractActivity experiments using GC analysis of reactor effluent have been combined with in situ IR spectroscopy to elucidate the reaction steps in the destructive adsorption of CHCl3, CH2Cl2, and CH3Cl over LaOCl. The IR results show that during reaction, LaOCl is covered with carbonate, formate, and methoxy groups. The relative amount of each of these surface intermediates depends on the Cl/H ratio of the reactant. The decomposition of the surface species leads to formation of the reaction products, and is influenced by the temperature and the relative amount of Cl present on the surface. The GC results show that the activity for the destructive adsorption of H‐containing chlorinated C1 compounds decreases with increasing hydrogen content of the reactant. The acquired insight into the mechanism of destructive adsorption is crucial to the design of new catalyst materials for the efficient conversion of chlorinated hydrocarbons into nonhazardous products or reusable chemicals.
Contrasting pKa of Protonated Bis(3‐aminopropyl)‐Terminated Polyethylene Glycol “Jeffamine” and the Associated Thermodynamic Parameters in Solution and Covalently Attached to Graphite Surfaces
Authors: Abiman Poobalasingam , Wildgoose Gregory G. , Crossley Alison , Jones John H. , Compton Richard G. 
Published: September 2007

AbstractThe pKa value of protonated Jeffamine (bis(3‐aminopropyl) terminated polyethylene glycol) in solution and attached as a monolayer to graphite surfaces has been determined using potentiometric titration. The protonated Jeffamine was found to have a pKa value of 9.7 in solution at 25 °C, whereas this value decreases to 7.1 when it is attached to a graphite surface. Potentiometric titrations from 25 to 40 °C allowed us to determine the surface pKa of the protonated Jeffamine at each temperature studied and hence to determine the enthalpy, entropy and Gibbs energy changes associated with the deprotonation of the amino‐terminated surface bound Jeffamine groups. It was found that the enthalpic contribution is negligibly small and the evaluation of these thermodynamic parameters controlling the shift in surface pKa value indicates that this process is controlled by entropic contribution arising from the ordering/disordering of solvent molecules at the carbon–water interface. This suggests that the long chain Jeffamine molecules are oriented on the carbon surface rather than existing in the bulk solution.
Copper‐Catalyzed Asymmetric Conjugate Addition of Trialkylaluminium Reagents to Trisubstituted Enones: Construction of Chiral Quaternary Centers
Authors: Vuagnoux‐d'Augustin Magali , Alexakis Alexandre 
Published: September 2007

AbstractMe3Al, Et3Al, and vinylalane species undergo enantioselective conjugate addition to a wide range of 2‐ or 3‐substituted enones (cyclopent‐2‐enones, cyclohex‐2‐enones, 3‐methyl cyclohept‐2‐enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3CN)4]BF4 or [CuOTf]2⋅C6H6) and tropos‐phosphoramidite‐based ligand. Thus, chiral quaternary centers can be built, with up to 98 % ee after rigorous optimization of experimental conditions. It was shown that the main important parameter was the order of the introduction of the reagents. Then, the generated enantioenriched aluminium enolates and the chiral conjugate adducts were functionalized and used for subsequent reactions.
Halogen—Magnesium Exchange on Unprotected Aromatic and Heteroaromatic Carboxylic Acids.
Authors: Kopp Felix , Wunderlich Stefan , Knochel Paul 
Published: September 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of Dolastatin 10 Through Ruthenium‐Catalyzed Asymmetric Hydrogenations.
Authors: Mordant Celine , Reymond Sebastien , Tone Hitoshi , Lavergne Damien , Touati Ridha , Ben Hassine Bechir , Ratovelomanana‐Vidal Virginie , Genet Jean‐Pierre 
Published: September 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New α‐Pyrone Derivative, 6‐[(E)‐Hept‐1‐enyl]‐α‐pyrone, with Tyrosinase Inhibitor Activity from a Marine Isolate of the Fungus Botrytis.
Authors: Zhang Dahai , Li Xianguo , Kang Jung Sook , Choi Hong Dae , Son Byeng Wha 
Published: September 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Comparison of Topological, Shape, and Docking Methods in Virtual Screening.
Authors: McGaughey Georgia B. , Sheridan Robert P. , Bayly Christopher I. , Culberson J. Chris , Kreatsoulas Constantine , Lindsley Stacey , Maiorov Vladimir , Truchon Jean‐Francois , Cornell Wendy D. 
Published: September 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Dendrimer‐Encapsulated Bimetallic Nanoparticles — Synthesis, Characterization, and Applications to Homogeneous and Heterogeneous Catalysis
Authors: Chandler Bert D. , Gilbertson John D. 
Published: September 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Dystonin/Bpag1—A link to what?
Authors: Young Kevin G. , Kothary Rashmi 
Published: September 2007

AbstractThe dystonin/Bpag1 cytoskeletal interacting proteins play important roles in maintaining cytoarchitecture integrity in skin and in the neuromuscular system. The most profound phenotype observed in the dystonin mutant dystonia musculorum (dt) mice is a severe movement disorder, attributed in large part to sensory neuron degeneration. The molecular basis for this phenotype is currently not clear, despite several studies indicating possible causes for the pathology in dt mice. Complicating the picture of what essential dystonin functions are lost in dt mice is the fact that our understanding of the very nature of what dystonin is has evolved greatly over the past decade. Elucidating the roles of dystonin most relevant to neuronal function and survival should help to shed light on some of the common mechanisms underlying neurodegeneration. Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.