bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cost-effectiveness of using recombinant human TSH prior to radioiodine ablation for thyroid cancer, compared with treating patients in a hypothyroid state: the German perspective
Authors: Mernagh P , Campbell S , Dietlein M , Luster M , Mazzaferri E , Weston A R 
Published: August 2006

Objective: This investigation evaluated the cost-effectiveness of radioiodine remnant ablation following preparation with recombinant human TSH (rhTSH), compared with the standard preparation, whereby patients are rendered hypothyroid.
Design: The economic evaluation relates to patients with well differentiated thyroid cancer who have undergone thyroidectomy, but have no metastases. The evaluation takes a societal perspective, considering costs and benefits to all parties. The benefits were expressed in units of quality-adjusted life years (QALY), so differences in life expectancy were captured with consideration of quality of life.
Methods: A lifetime Markov model with Monte Carlo simulation of 100 000 patients was used to assess cost per QALY gained. The clinical inputs were sourced from a multi-centre, randomised controlled trial comparing remnant ablation success after rhTSH-preparation with hypothyroid preparation. The model applied German unit costs, however, the structure is generalisable to other jurisdictions. The additional cost of rhTSH procurement and administration is considered relative to the clinical benefits and cost offsets. These included avoidance of hypothyroidism, increased work productivity, earlier discharge from radioprotection and a theoretical reduction in the risk of secondary malignancy. The latter two benefits relate to faster radioiodine clearance after rhTSH preparation.
Results: The additional benefits of rhTSH (0.0495 QALY) are obtained with an incremental societal cost of €47, equating to an incremental cost per QALYof €958. Sensitivity analyses had only a modest impact upon cost-effectiveness, with all one-way sensitivity results remaining under €15 000/QALY.
Conclusions: The use of rhTSH prior to radioiodine ablation represents good value-for-money with the benefits to patient and society obtained at modest net cost.
The effects of tumour necrosis factor-α and interleukin1 on an in vitro model of thyroid-associated ophthalmopathy; contrasting effects on adipogenesis
Authors: Cawood T J , Moriarty P , O’Farrelly C , O’Shea D 
Published: August 2006

Objective: Cytokines are likely to play a key pathogenic role in thyroid-associated ophthalmopathy (TAO). Anti-cytokine therapy has been proposed to be a possible treatment for active TAO. We aimed to establish the effects of selected cytokines on intercellular adhesion molecule 1 (ICAM1) expression, glycosaminoglycan (GAG) production and adipogenesis in orbital fibroblasts (OFs) from patients with TAO.
Methods: Orbital tissue was taken during surgery from eight patients with TAO and five control subjects. OFs were cultured and ICAM1 expression measured by flow cytometry. GAG production was measured by hyaluronic acid ELISA. OFs were grown in adipogenic media and the degree of adipogenesis quantified.
Results: Responses were similar in OFs from patients with and without TAO. Tumour necrosis factor-α (TNFα) and interleukin1 (IL1) (0.1 ng/ml) stimulated ICAM1 expression by eight- to ten-fold. Anti-cytokine agents inhibited the cytokine-upregulated ICAM1 expression by 90–99% (P<0.01). TNFα and IL1 (0.1 ng/ml) increased hyaluronic acid production by 44 and 95% (P<0.01) respectively. Anti-cytokine agents inhibited these responses by 79–138% (P<0.04). TNFα (0.1 ng/ml) inhibited adipogenesis (−0.013 AU and −1.0; P<0.03) whilst IL1 (0.1 ng/ml) stimulated adipogenesis (+0.05 AU and +5.7; P<0.02) measured by oil-red-O extraction and visual assessment respectively. The anti-IL1 agent inhibited IL1-mediated adipogenesis by 69–106% (P<0.04).
Conclusion: TNFα and IL1 stimulate ICAM1 expression and GAG production, but have opposite effects on adipogenesis in OFs in vitro. IL1 promotes adipogenesis and its effects can be blocked by anti-IL1 agents in vitro. These agents may be the anti-cytokine treatment of choice for clinical trials in active TAO.
On schemes for congruence distributivity
Authors: Chajda I. , Halaš R. 
Published: August 2006

Abstract
We present diagrammatic schemes characterizing congruence 3-permutable and distributive algebras. We show that a congruence 3-permutable algebra is congruence meetsemidistributive if and only if it is distributive. We characterize varieties of algebras satisfying the so-called triangular scheme by means of a Maltsev-type condition.
Modulating the Activity and Selectivity of an Immobilized Ruthenium‐Porphyrin Catalyst using a Fluorous Solvent
Authors: Burri Estelle , Leeder Shannon M. , Severin Kay , Gagné Michel R. 
Published: August 2006

AbstractA ruthenium porphyrin catalyst with styrene side chains was incorporated into a highly cross‐linked polymer by co‐polymerization with ethylene glycol dimethacrylate in the presence of a chloroform porogen. Oxidation reactions catalyzed by the resulting polymer were accelerated when perfluoromethylcyclohexane (PFMC) was used as a co‐solvent. Moreover, the PFMC co‐solvent was found to change the substrate selectivity of the catalytic reactions. Both effects could be explained by a PFMC‐induced partitioning of substrates and oxidant into the polymeric, catalyst containing matrix.
Enantioselective Catalysis on the Solid Phase: Synthesis of Natural Product‐Derived Tetrahydropyrans Employing the Enantioselective Oxa‐Diels–Alder Reaction
Authors: Sanz Miguel A. , Voigt Tobias , Waldmann Herbert 
Published: August 2006

AbstractAliphatic aldehydes were synthesized on a solid support and subjected to an enantioselectively catalyzed oxa‐Diels–Alder reaction with Danishefsky’s diene. Employing 5 mol % of a Cr(III)‐salen catalyst enantiomeric ratios up to>99 % and yields up to 40 % over five steps were achieved. Further elaboration of the polymer‐bound dihydropyrones was performed by subsequent conjugate cuprate addition, reduction of the ketone and transformation of the resulting alcohol to a carbamate yielding 2,4,6‐trisubstituted tetrahydropyrans after cleavage from the solid support.
Polymer‐Supported Chiral Schrock Catalysts Immobilized via the Arylimido Ligand
Authors: Wang Dongren , Kröll Roswitha , Mayr Monika , Wurst Klaus , Buchmeiser Michael R. 
Published: August 2006

AbstractThe immobilization of both chiral and non‐chiral versions of the Schrock catalyst via the arylimido ligand was accomplished for the first time. For this purpose, four different 4‐(6‐halogenohexyl)‐2,6‐R2‐anilines, i.e., {4‐[6‐X‐(CH2)6]‐2,6‐R2‐C6H2‐NH2} (7: R=Me, X=Br; 8: R=Me, X=Cl, 9: R=2‐Pr, X=Cl, 10: R=2‐Pr, X=Br) were prepared and used for the synthesis of the corresponding Mo‐bis(imido)dichloro complexes Mo{N‐2,6‐R2‐4‐[6‐X‐(CH2)6]‐C6H2}2Cl2⋅DME (11: R=Me, X=Br; 12: R=Me, X=Cl; 13: R=2‐Pr, X=Cl; 14: R=2‐Pr, X=Br). Compounds 11–14 were transformed into the corresponding Mo‐bis(imido)dialkyl complexes Mo{N‐2,6‐R2‐4‐[6‐X‐(CH2)6]‐C6H2}2(CH2CMe2Ph)2 (15: R=Me, X=Br; 16: R=Me, X=Cl, 17: R=2‐Pr, X=Cl; 18: R=2‐Pr, X=Br). These were used for the synthesis of the Mo‐imidoalkylidene triflates Mo{N‐2,6‐R2‐4‐[6‐X‐(CH2)6]‐C6H2}(CHCMe2Ph)(OTf)2⋅DME (19: R=Me, X=Br; 20: R=2‐Pr, X=Br, 21: R=2‐Pr, X=Cl). Compounds 19‐‐21 were used in the synthesis of the Schrock type catalysts Mo{N‐2,6‐Me2‐4‐[6‐Br‐(CH2)6]‐C6H2}(CHCMe2Ph)[OC(CH3)(CF3)2]2 (22) and Mo{N‐2,6‐(2‐Pr)2‐4‐[6‐Cl‐(CH2)6]‐C6H2}(CHCMe2Ph)[OC(CH3)(CF3)2] (23), Mo{N‐2,6‐Me2‐4‐[6‐Br‐(CH2)6]‐C6H2}(CHCMe2Ph)[(R)‐BIPHEN] (24) and Mo{N‐2,6‐(2‐Pr)2‐4‐[6‐Br‐(CH2)6]‐C6H2}(CHCMe2Ph)[(R)‐BIPHEN] (25). Compounds 22, 24 and 25 were immobilized on Ag‐perfluoroalkylsulfonate‐modified PS‐ and PS‐DVB materials to yield the corresponding immobilized catalysts Mo{N‐2,6‐Me2‐4‐[PS‐CH2‐O‐CF2‐CF(CF3)‐SO3‐(CH2)6]‐C6H2}(CHCMe2Ph)[OCMe(CF3)2]2 (26), Mo{N‐2,6‐Me2‐4‐[PS‐DVB‐CH2‐O‐CF2‐CF(CF3)‐SO3‐(CH2)6]‐C6H2}(CHCMe2Ph)[(R)‐BIPHEN] (27) Mo{N‐2,6‐(2‐Pr)2‐4‐[PS‐DVB‐CH2‐O‐CF2‐CF(CF3)‐SO3‐(CH2)6]‐C6H2}(CHCMe2Ph)[(R)‐BIPHEN] (28). These were used in a series of ring‐closing metathesis (RCM), ring‐opening cross metathesis, asymmetric RCM and desymmetrization reactions. The use of 27 and 28 resulted in values for enantiomeric excess (ee) virtually identical to those obtained with the corresponding homogeneous chiral catalysts.
Ionic‐Liquid‐Supported Organocatalyst: Efficient and Recyclable Ionic‐Liquid‐Anchored Proline for Asymmetric Aldol Reaction
Authors: Miao Weishi , Chan Tak Hang 
Published: August 2006

AbstractIonic‐liquid‐anchored (2S,4R)‐4‐hydroxyproline 12 catalyzes direct asymmetric aldol reactions with comparable enantioselectivities in DMSO, and with superior enantioselectivities in neat acetone or 2‐butanone, than (S)‐proline (8) (up to 28 % ee difference) itself. Furthermore, the supported catalyst 12 can be easily recycled and reused for at least four times without significant loss of yields and enantioselectivity.
Asymmetric Synthesis of α‐Acyl‐γ‐butyrolactones Possessing All‐Carbon Quaternary Stereocenters by Phase‐Transfer‐Catalyzed Alkylation
Authors: Ooi Takashi , Miki Takashi , Fukumoto Kazuhiro , Maruoka Keiji 
Published: August 2006

AbstractThe enantioselective construction of all‐carbon quaternary stereocenters on α‐acyl‐γ‐butyrolactones has been achieved by the N‐spiro chiral quaternary ammonium bromide 1‐catalyzed alkylation under mild phase‐transfer conditions. The resulting α‐alkylated keto lactones serve as valuable chiral building blocks in organic synthesis as clearly demonstrated by the facile conversion to optically active α,α‐dialkyl‐α‐amino acid derivatives via Schmidt rearrangement.
Preparation, Characterization and Catalytic Properties of Polyaniline‐Supported Metal Complexes
Authors: Choudary Boyapati M. , Roy Moumita , Roy Sarabindu , Kantam M. Lakshmi , Sreedhar Bojja , Kumar Karasala Vijay 
Published: August 2006

AbstractPolyaniline‐supported Sc, In, Pd, Os and Re catalysts were prepared by using a simple protocol and the thus prepared catalysts were well characterized using FTIR, XPS, UV‐Vis/DRS, TGA‐DTA. All the catalysts were successfully employed in a wide range of organic transformations such as cyanation and allylation of carbonyl compound, Suzuki coupling of aryl halides and boronic acids, and, most importantly, in asymmetric dihydroxylation of olefins to afford optically active vicinal diols. All the catalysts were separated from the reaction mixture by simple filtration and reused with consistent activity for five cycles without noticeable leaching of metal from the support.
Maximise Equilibrium Conversion in Biphasic Catalysed Reactions: Mathematical Description and Practical Guideline
Authors: Eckstein Marrit F. , Peters Martina , Lembrecht Julia , Spiess Antje C. , Greiner Lasse 
Published: August 2006

AbstractWhat is the best solvent combination for a catalytic biphasic reaction system to maximise equilibrium conversion? And which phase volume ratio and reaction stoichiometry maximises the conversion? Which product yield can be obtained using a distinct biphasic reaction mixture? These questions are essential, as optimisation can only be carried out within the thermodynamically imposed boundaries. Within this paper we introduce a mathematical expression to calculate and predict equilibrium conversion and product yield in biphasic reaction mixtures with only one reactive phase. This mathematical expression allows a time‐saving design of biphasic experiments with respect to maximum conversion and product yield. The calculations were verified by experimental data obtained from a substrate‐coupled alcohol dehydrogenase‐catalysed reduction under different biphasic reaction conditions.
Thermoregulated Liquid/Liquid Catalyst Separation and Recycling
Authors: Behr Arno , Henze Guido , Schomäcker Reinhard 
Published: August 2006

AbstractConsiderable effort has been done to overcome the loss of catalyst in homogeneously catalysed processes. In this contribution we describe five recycling concepts for thermoregulated catalyst separation and recycling: fluorous biphasic systems (FBS), thermoregulated phase transfer catalysis (TRPTC), soluble polymer‐based catalysis, thermoregulated microemulsions and temperature‐dependent multicomponent solvent systems (TMS). Each of these concepts has its own special advantages like low catalyst leaching or simple process engineering but also drawbacks like usage of expensive special solvents or complex and expensive catalysts. In this context, TMS systems exhibit most advantages of the other concepts combined with the possibility to use common and cheap solvents as well as numerous classical molecular catalysts. Therefore, TMS systems are expected to be one of the most promising thermomorphic recycling concepts for industrial scale.
Immobilization of Organic Catalysts: When, Why, and How
Authors: Cozzi Franco 
Published: August 2006

AbstractThis review article is divided in two parts. In the first part (Sections 2 and 3) selected examples of the publications that appeared in the literature in the period 2003–2005 in the field of immobilized organic catalysis are presented. When appropriate, the results of these publications are compared to those reported earlier and already discussed in a previous review article (see ref. 4). On the basis of this survey, in Section 4 some general considerations about when and why a supported version of an organic catalyst is worth developing are proposed. In Section 4 a list of suggestions about how the process of immobilization should be carried out is also included, taking into account several factors such as the properties of the catalyst, the nature of the support, and the mode of connection of the catalyst to the support.
Synthesis of C‐Glycosides and C‐Disaccharides using Mukaiyama Aldol Reaction in Aqueous Media
Authors: Zeitouni Jennifer , Norsikian Stéphanie , Merlet Denis , Lubineau André 
Published: August 2006

AbstractWe describe here a new strategy for the preparation of C‐glycosides and C‐disaccharides in the aqueous phase using the Mukaiyama aldol reaction. We first studied the reaction between formyl‐2,3,4,6‐tetra‐O‐benzyl‐β‐D‐glucopyranoside 1 and the trimethylsilyl enol ether 2 derived from acetophenone. Using Yb(OTf)3 (10 mol %) as catalyst in a mixture of THF/water at room temperature, the enol adducts were isolated in a high (90 %) yield but with a moderate diastereoselectivity. The reaction can also be performed in pure THF leading to a single diastereoisomer but in a much lower yield (56 %). The aldol reaction was then applied to the synthesis of C‐disaccharides using the trimethylsilyl enol ether 10 derived from the functionalized ketone 9. In both the aqueous phase and in anhydrous THF, the reaction can be achieved in high yields giving in each case only two aldol products out of the four possible diastereoisomers.
Structural Modification of Polymer‐Supported Ionic Liquids as Catalysts for Nucleophilic Substitution Reactions Including Fluorination
Authors: Kim Dong Wook , Hong Dong Jin , Jang Keun Sam , Chi Dae Yoon 
Published: August 2006

AbstractA polymer‐supported ionic liquid (PSIL) system was reported to be a highly efficient catalyst in nucleophilic fluorination and other nucleophilic substitution reactions using metal salts. In this study we have prepared structurally modified PSIL systems and examined their catalytic activity in nucleophilic fluorination and other substitution reactions in dependence on the length of the alkyl chain linker, counteranion, and the ionic liquid loading in the resin. The PSIL system with a longer alkyl linker had better catalytic activity, and the PSIL system with tetrafluoroborate (BF4‐) as the counteranion showed the best catalytic activity among the other counteranions. The nucleophilic fluorination of 2‐(3‐methanesulfonyloxypropyl)naphthalene (2), as a model compound, with cesium fluoride in the presence of a 0.5 equivs. of an ionic liquid portion of PS[domim][BF4] (polymer‐supported 1‐n‐dodecyl‐3‐methylimidazolium tetrafluoroborate) was completed within 2.5 h, affording the fluoroalkane 3 (96 %). The PSIL system with a higher ionic loading as a catalyst produced a better fluorination, while the PSIL system with a lower loading produced a better bromination. In addition, these PSIL systems had good swelling properties in polar aprotic solvents such as DMF (7.2 mL/g), DMSO (6.5 mL/g) and acetonitrile (5.2 mL/g). Based on the swelling of PSIL, nucleophilic acetoxylation and fluorination reactions were carried out in four different solvents. It was found that the PSIL with a longer alkyl linker had superior catalytic activity due to the longer distance between the polystyrene backbone and ionic liquid portion. The PSIL system with tetrafluoroborate (BF4−) as the counteranion shows the best catalytic activity compared with PSIL systems with other counteranions. These PSIL systems absorb polar aprotic solvents and swell considerably, which is a favorable characteristic in new types of resins for other applications.
Multipurpose box‐ and azabox‐Based Immobilized Chiral Catalysts
Authors: Fraile José M. , Pérez Ignacio , Mayoral José A. , Reiser Oliver 
Published: August 2006

AbstractAzabis(oxazolines) can be used as chiral ligands in the copper‐catalyzed enantioselective Mukaiyama aldol reaction. When supported on solids, azabis(oxazoline)‐copper complexes are more easily deactivated than their analogous bis(oxazoline)‐copper complexes, and are not compatible with the use of coordinating solvents in the method of preparation. The performance of the immobilized catalysts (up to 86 % ee) depends on the support and the reaction solvent, with some positive effect on enantioselectivity due to surface effects. The deactivation is not irreversible and the deactivated catalysts show excellent performance in the cyclopropanation reaction, providing added value to the supported multipurpose catalysts.
An Immobilized Organocatalyst for Cyanosilylation and Epoxidation
Authors: Yamaguchi Kazuya , Imago Toru , Ogasawara Yoshiyuki , Kasai Jun , Kotani Miyuki , Mizuno Noritaka 
Published: August 2006

AbstractAn immobilized organocatalyst has been synthesized by covalently anchoring an N‐octyldihydroimidazolium hydroxide fragment onto SiO2 (denoted as 1‐OH/SiO2). This catalyst exhibits high catalytic performance for the cyanosilylation of various carbonyl compounds with trimethylsilyl cyanide (Me3SiCN). The effectiveness of the system is evidenced by the high to excellent yields of the corresponding trimethylsilyl ethers under mild reaction conditions, which are superior to those obtained with commercially available MgO and anion exchange resins. This catalyst also acts as a heterogeneous catalyst for the epoxidation of electron‐deficient olefins with hydrogen peroxide. Further, the catalyst/product(s) separation can be easily carried out by the simple filtration (or centrifugation) and the reaction is immediately stopped by the removal of the solid catalyst, suggesting that the nature of the observed catalysis is truly heterogeneous.
New Recoverable Poly(ethylene glycol)‐Supported C1‐Diamino‐oligothiophene Ligands for Palladium‐Promoted Asymmetric Allylic Alkylation (AAA) Reactions
Authors: Bandini Marco , Benaglia Maurizio , Quinto Tommaso , Tommasi Simona , Umani‐Ronchi Achille 
Published: August 2006

AbstractA new class of chiral C1‐symmetrical diamino‐oligothiophene ligands easy‐grafted on a soluble polymeric support (MeOPEG5000) is described. The diamines were found to be effective promoting agents for the [Pd(0)]‐catalysed asymmetric allylic alkylation (AAA) of dimethyl malonate in high yields and excellent enantioselectivity (ee up to 99 %). The supported chiral ligand was readily recovered by precipitation and filtration was recycled up to three times without an appreciable loss in activity. The recycle of the organometallic catalytic system was also investigated.
Electroreductive Palladium‐Catalysed Ullmann Reactions in Ionic Liquids: Scope and Mechanism
Authors: Pachón Laura Durán , Elsevier Cornelis J. , Rothenberg Gadi 
Published: August 2006

AbstractA room‐temperature catalytic alternative to the Ullmann reaction is presented, based on electroreductive homocoupling of haloarenes catalysed by palladium nanoparticles. The particles are generated in situ in an electrochemical cell, and electrons are used to close the catalytic cycle and provide the motivating force for the reaction. This system gives good yields using iodo‐ and bromoarenes, and requires only electric current and water as reagents. Using an ionic liquid solvent combines the advantages of excellent conductivity and cluster stabilising. The solvent is reusable at least five times. Kinetic experiments at different electrode potentials show that the two‐electron oxidation of water closes the catalytic cycle by regenerating the Pd(0). A mechanism involving radical anion formation is proposed. The advantages and limitations of this new system for carbon‐carbon homocoupling and cross‐coupling are discussed.
In situ Synthesis of Gold Nanoparticles inside the Pores of MCM‐48 in Supercritical Carbon Dioxide and its Catalytic Application
Authors: Chatterjee M. , Ikushima Y. , Hakuta Y. , Kawanami H. 
Published: August 2006

AbstractGold nanoparticles are deposited into the channels of MCM‐48 through a simple H2‐assisted reduction of HAuCl4 (aqueous solution) in supercritical carbon dioxide medium at 70 °C within 2–4 h. The nanoparticles were characterized by powder X‐ray diffraction (PXRD), N2 adsorption‐desorption, transmission electron microscopy (TEM), and UV‐Vis spectroscopy. The particle size of the synthesized material is tunable with the pressure (density) of the supercritical carbon dioxide medium. At the fixed temperature (70 °C) and hydrogen pressure [P(H2)=2 MPa], the Au particle size varies from ca. 25 nm to ca. 2 nm with the change in CO2 pressure from 7 MPa to 17 MPa. At the low solvent density conditions, larger particles of ∼25 nm were obtained. On the contrary, a high solvent density of CO2 slows down particle aggregation, resulting in the small particle size within the range of 2–5 nm. This change in particle size with CO2 pressure and the interaction of the particles with the silica support were correlated well with long‐range van der Waals interactions and consequently the Hamaker constant for the gold nanoparticle‐CO2 (A131) and silica‐gold core‐CO2 (A132), respectively. Supercritical carbon dioxide alone can provide a unique environment for stabilizing gold nanoparticles in the channels of the cubic mesoporous MCM‐48 support and exquisite control of the particle size without perturbing the support structure. The synthesized material is highly stable, recyclable and no metal nanoparticle leaching was observed. The selective hydrogenation of crotonaldehyde with the synthesized material provides convincing evidence that the particles are inside the pores and available to the reactant molecules.