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Terms modified by TOF Selected AbstractsVery Fast Suzuki,Miyaura Reaction Catalyzed by Pd(OAc)2 under Aerobic Conditions at Room Temperature in EGME/H2OEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 1 2009Alessandro Del Zotto Abstract The results of a ligand-free Pd(OAc)2 -catalyzed Suzuki,Miyaura C,C coupling performed at room temperature under aerobic conditions are presented. It was found that the use of an ethylene glycol monomethyl ether/H2O mixture as the solvent resulted in very rapid reactions of aryl bromides with arylboronic acids. As a matter of fact, under optimized conditions, some substrates were converted quantitatively in less than 1 min with exceptionally high TOF values. For example, the reaction between 4-methoxyphenylboronic acid and bromobenzene afforded 4-methoxybiphenyl in 30 s with TOF = 180000 h,1. Furthermore, the reaction tolerates a wide range of functional groups and can be successfully applied to heteroaryl bromides such as 2-bromopyridine and 5-bromopyrimidine. Interestingly, also an activated aryl chloride such as 1-chloro-4-nitrobenzene reacted quantitatively with phenylboronic acid at 373 K. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Efficient, Stable Bulk Charge Transport in Crystalline/Crystalline Semiconductor,Insulator BlendsADVANCED MATERIALS, Issue 44 2009Avinesh Kumar Efficient and stable ambipolar charge transport in the bulk of crystalline/crystalline P3HT/HDPE systems, as evidenced by time-of-flight (TOF) photoconductivity measurements, is found. Interestingly, certain blend compositions displayed significantly enhanced bulk charge-transport properties compared to neat P3HT, with ,TOF measured for 80:20,wt% P3HT:PE blends being up to one order of magnitude higher than those found in neat P3HT. [source] A novel mutation in the GATA4 gene in patients with Tetralogy of Fallot,,HUMAN MUTATION, Issue 3 2006Georges Nemer Abstract In vertebrates, heart formation which integrates different structures and cell types is a complex process that involves a network of genes regulated by transcription factors. Proper spatiotemporal expression of these factors ensure the highly needed tight control of each step in organogenesis. A mistake at any step from cell-commitment to valve formation will have a major impact on heart morphogenesis and function leading to congenital heart disease (CHD). Cardiac abnormalities occur with an incidence of one per 100 live births and represent 25% of all congenital malformations. As an alternative approach to linkage-analysis of familial cases of CHD, we started screening familial and sporadic cases of CHDs in a highly consanguineous population for mutations in genes encoding cardiac-enriched transcription factors. The evolutionarily conserved role of these proteins in cardiac development suggested a role in CHD. In this study, we report a mutation in the gene encoding GATA4, one of the earliest markers of heart development. This mutation was found in two out of 26 patients with Tetralogy of Fallot (TOF), and in none of the 94 patients with different phenotypes included in the study, nor in 223 healthy individuals. The heterozygous mutation results in an amino acid substitution in the first zinc finger of GATA4 that reduced its transcriptional activation of downstream target genes, without affecting GATA4 ability to bind DNA, nor its interaction with ZFPM2. © 2006 Wiley-Liss, Inc. [source] Identification of four low molecular and water-soluble proteins from grape (Vitis vinifera L.) seedsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2010Ting Zhou Summary Profiles of soluble proteins isolated from mature seeds of grape (Vitis vinifera L.) pomace were studied using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) coupled with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI,TOF,MS). Two-dimensional gels stained with Coomassie brilliant blue revealed more than fifty protein spots. Four abundant protein spots showing low molecular weight (Mr) and wide isoelectric point (pI) were analysed by MALDI,TOF,MS, resulting in their identification. Taken together, these results suggest that identified proteins may be linked to seed development and metabolism, but more instructive is that they have some potential functions for future food application. These results provide some insights into conversion of grape processing wastes into useful products or even as raw material for other industries. [source] Grafting of Molecularly Ordered Mesoporous Phenylene-Silica with Molybdenum Carbonyl Complexes: Efficient Heterogeneous Catalysts for the Epoxidation of OlefinsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010Abstract Arenetricarbonyl complexes, or the general formula C6H4Mo(CO)3, were incorporated into crystal-like mesoporous phenylene-silica by liquid-phase deposition of molybdenum hexacarbonyl [Mo(CO)6]. By adjusting the reaction conditions, different molybdenum loadings of 1.5 and 5.9,wt% were obtained, which correspond to 3% and 14% of the phenylene contents. The texture properties of the materials as well as the nature of the surface-fixed complexes were characterized by powder X-ray diffraction, transmission electron microscopy (TEM), N2 adsorption, FT-IR, UV-vis and MAS (13C, 29Si) NMR spectroscopy. The derivatized organosilicas were examined as catalyst precursors for the liquid-phase epoxidation of cis -cyclooctene, 1-octene, trans -2-octene and (R)-(+)-limonene at 55,°C, using tert -butyl hydroperoxide as the oxidant. For each olefin the corresponding epoxide was the only product detected. In the case of cyclooctene, the intrinsic reaction rates per surface molybdenum atom were similar for both Mo loadings (TOF,1150 mol,molMo,1,h,1), suggesting that the resultant materials act as single site epoxidation catalysts. Leaching tests and metal analyses of reaction solutions showed that the catalytic activity stemmed from the immobilized species and not from the leaching of active species into solution. The oxidation of limonene gave limonene oxide as the only product in 95% yield at 3,h, which reveals an outstanding regioselectivity to the epoxidation of the endocyclic double bond. [source] Highly Enantioselective Hydrogenation of Quinoline and Pyridine Derivatives with Iridium-(P-Phos) CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Wei-Jun Tang Abstract The use of a chiral iridium catalyst generated in situ from the (cyclooctadiene)iridium chloride dimer, [Ir(COD)Cl]2, the P-Phos ligand [4,4,-bis(diphenylphosphino)-2,2,,6,6,-tetramethoxy-3,3,-bipyridine] and iodine (I2) for the asymmetric hydrogenation of 2,6-substituted quinolines and trisubstituted pyridines [2-substituted 7,8-dihydroquinolin-5(6H)-one derivatives] is reported. The catalyst worked efficiently to hydrogenate a series of quinoline derivatives to provide chiral 1,2,3,4-tetrahydroquinolines in high yields and up to 96% ee. The hydrogenation was carried out at high S/C (substrate to catalyst) ratios of 2000,50000, reaching up to 4000,h,1 TOF (turnover frequency) and up to 43000 TON (turnover number). The catalytic activity is found to be additive-controlled. At low catalyst loadings, decreasing the amount of additive I2 was necessary to maintain the good conversion. The same catalyst system could also enantioselectively hydrogenate trisubstituted pyridines, affording the chiral hexahydroquinolinone derivatives in nearly quantitative yields and up to 99% ee. Interestingly, increasing the amount of I2 favored high reactivity and enantioselectivity in this case. The high efficacy and enantioselectivity enable the present catalyst system of high practical potential. [source] Continuous Hydrogen Generation from Formic Acid: Highly Active and Stable Ruthenium CatalystsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Albert Boddien Abstract The ruthenium-catalyzed decomposition of formic acid was investigated with respect to continuous hydrogen generation and long-term stability of the catalytic systems. A highly active and stable system is presented, which was studied in batch and continuous modes for up to two months. The optimized catalyst system containing N,N -dimethyl- n -hexylamine with an in situ generated catalyst from (benzene)ruthenium dichloride dimer [RuCl2(benzene)]2 and 6 equivalents of 1,2-bis(diphenylphosphino)ethane (dppe) reached at room temperature a total turnover number (TON) of approximatly 260,000 with average turnover frequency (TOF) of about 900,h,1. Only hydrogen and carbon dioxide were detected in the produced gas mixture which makes this system applicable for direct use in fuel cells. [source] Efficient Aerobic Oxidation of Alcohols using a Hydrotalcite-Supported Gold Nanoparticle CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Takato Mitsudome Abstract Hydrotalcite-supported gold nanoparticles (Au/HT) were found to be a highly efficient heterogeneous catalyst for the aerobic oxidation of alcohols under mild reaction conditions (40,°C, in air). This catalyst system does not require any additives and is applicable to a wide range of alcohols, including less reactive cyclohexanol derivatives. This Au/HT catalyst could also function in the oxidation of 1-phenylethanol under neat conditions; the turnover number (TON) and turnover frequency (TOF) reached 200,000 and 8,300,h,1, respectively. These values are among the highest values compared to those of other reported catalyst systems at high conversion. Moreover, the Au/HT can be recovered by simple filtration and reused without any loss of its activity and selectivity. [source] An Efficient Solvent-Free Route to Silyl Esters and Silyl EthersADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Yuko Ojima Abstract Dinuclear metal complexes, especially (p -cymene)ruthenium dichloride dimer {[RuCl2(p -cymene)]2}, have been found to exhibit high catalytic performance for the dehydrosilylation of various kinds of carboxylic acids and alcohols. The dehydrosilylation with [RuCl2(p -cymene)]2 proceeded efficiently with only one equivalent of silane with respect to substrate (carboxylic acids or alcohols) under solvent-free conditions to give the corresponding silyl esters and ethers in excellent yields with a high turnover number (TON) and frequency (TOF). The 1H,NMR spectrum of a toluene- d8 solution of [RuCl2(p -cymene)]2 and a silane showed a signal assignable to the ruthenium hydride species. In contrast, no new signals were detected in the 1H,NMR spectrum of a toluene- d8 solution of [RuCl2(p -cymene)]2 and a carboxylic acid or an alcohol. Therefore, the ruthenium metal in [RuCl2(p -cymene)]2 activates a silane to afford the hydride intermediate, possibly a silylmetal hydride species. Then, the nucleophilic attack of a substrate (carboxylic acid or alcohol) to the hydride intermediate proceeds to give the corresponding silylated product. The present dehydrosilylation with an optically active silane proceeded exclusively under inversion of stereochemistry at the chiral silicon center, suggesting that the nucleophilic attack of a substrate to the hydride intermediate occurs from the backside of the ruthenium-silicon bond. [source] Time course of rocuronium-induced neuromuscular block after pre-treatment with magnesium sulphate: a randomised studyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2010C. CZARNETZKI Background: A previously published study suggested that pre-treatment with magnesium sulphate (MgSO4) had no impact on the speed of onset of rocuronium-induced neuromuscular block. We set out to verify this assumption. Methods: Eighty patients (18,60 years) were randomly allocated to MgSO4 60 mg/kg or placebo (saline). Study drugs were given intravenously for 15 min before induction of anaesthesia with propofol, sufentanil and rocuronium 0.6 mg/kg. Anaesthesia was maintained with a target-controlled propofol infusion. Neuromuscular transmission was measured using train-of-four (TOF)-Watch SX® acceleromyography. Results: Onset was analysed in 37 MgSO4 and 38 saline patients, and recovery in 35 MgSO4 and 37 saline patients. Onset time (to 95% depression of T1) was on average 77 [SD=18] s with MgSO4 and 120 [48] s with saline (P<0.001). The total recovery time (DurTOF0.9) was on average 73.2 [22] min with MgSO4 and 57.8 [14.2] min with saline (P<0.003). The clinical duration (Dur25%) was on average 44.7 [14] min with MgSO4 and 33.2 [8.1] min with saline (P<0.0002). The recovery index (Dur25,75%) was on average 14.0 [6] min with MgSO4 and 11.2 [5.2] min with saline (P<0.02). The recovery time (Dur25%TOF0.9) was on average 28.5 [11.7] min with MgSO4 and 24.7 [8.4] min with saline (P=0.28). Conclusion: Magnesium sulphate given 15 min before propofol anaesthesia reduces the onset time of rocuronium by about 35% and prolongs the total recovery time by about 25%. Trial Registration: Clinicaltrials.gov identifier: NCT00405977. [source] Knowledge of residual curarization: an Italian surveyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2010P. DI MARCO Background: The use of neuromuscular blocking agents (NMBAs) is widespread in anesthetic practice; little is known about the current use of these drugs in Italy. This survey was conducted to obtain information about the most commonly used clinical tests and the train-of-four (TOF) ratios that are considered as being reliable for assessing recovery from neuromuscular blockade at the end of anesthesia and the estimated occurrence rates of post-operative paralysis in Italian hospitals. Methods: The questionnaire was given to Italian anesthesiologists attending the 62nd National Congress of the Italian Society of Anesthesia, Analgesia and Intensive Therapy. Collected data were stratified by age and the total number of surgical procedures performed in the hospitals concerned. Results: Seven hundred and fifty-four correctly compiled questionnaires were collected (response rate 88.7%). Seventy three percent of the respondents only used clinical tests for monitoring the level of neuromuscular blockade. The main clinical tests cited for the evaluation of residual paralysis were keeping the head lifted up for 5 s, protruding the tongue and opening the eyes. TOF was used by 35% of the respondents on a routine basis. Only 24% of the interviewed anesthesiologists reported that before extubation, a TOF ratio of at least 0.9 should be reached. Conclusions: Most Italian anesthetists assess the recovery from neuromuscular blockade only by clinical signs. There is poor awareness about the inability of such techniques to indicate even a significant amount of residual neuromuscular block. A more extensive use of quantitative instrumental monitoring is required for the more rational use of NMBAs. [source] Photooxidation of Benzyl Alcohols with Immobilized FlavinsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2009Harald Schmaderer Abstract Benzyl alcohols are oxidized cleanly and efficiently to the corresponding aldehydes under irradiation using flavin photocatalysts and aerial oxygen as the terminal oxidant in homogeneous aqueous solution. Turnover frequencies (TOF) of more than 800,h,1 and turnover numbers (TON) of up to 68 were obtained. Several flavin photocatalysts with fluorinated or hydrophobic aliphatic chains were immobilized on solid supports like fluorous silica gel, reversed phase silica gel or entrapped in polyethylene pellets. The catalytic efficiency of the heterogeneous photocatalysts was studied for the oxidation of different benzyl alcohols in water and compared to the analogous homogeneous reactions. Removal of the heterogeneous photocatalyst stops the reaction conversion immediately, which shows that the immobilized flavin is the catalytically active species. The immobilized catalysts are stable, retain their reactivity if compared to the corresponding homogeneous systems and are easily removed from the reaction mixture and reused. TOF of up to 26,h,1, TON of 280 and up to 3 reaction cycles without loss of activity are possible with the heterogeneous flavin photocatalysts. [source] Asymmetric Synthesis of the Roche Ester and its Derivatives by Rhodium-INDOLPHOS-Catalyzed HydrogenationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2008Jeroen Wassenaar Abstract (S)-3-Hydroxy-2-methylpropionate, known as the Roche ester, and several of its derivatives were successfully synthesized through asymmetric rhodium-catalyzed hydrogenation, using INDOLPHOS (diisopropyl{1-[(S)-3,5-dioxa-4-phosphacyclohepta[2,1- a;3,4- a,]dinaphthalen-4-yl]-3-methyl-2-indolyl}phosphine) as the chiral ligand, in excellent yield and the highest ee reported up to now (TOF over 5500,h,1 at 25,°C; up to 98% ee at ,40,°C). [source] Discrete versus In Situ -Generated Aluminum-Salen Catalysts in Enantioselective Cyanosilylation of Ketones: Role of Achiral LigandsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2008Ali Alaaeddine Abstract The monometallic species {Salen}AlX (X=Me, 2a,b; X=Cl, 4a,b; O- i- Pr, 5a,b) and open bimetallic species {Salen}[AlMe2]2 (3a,b) that result from binary combinations between an aluminum precursor [trimethylaluminum, dimethylaluminum chloride, aluminum tris(isopropoxide)] and a diprotio {Salen}H2 pro-ligand 1a,b (a=1R,2R -cyclohexyl-salen; b=1R,2R -diphenylethylene-salen) have been isolated. The crystal structures of 3b, 4b and of ,-oxo species [{diphenylethylene-salen}Al]2O (6b) are reported. The discrete species 2,5a,b have been individually evaluated in the asymmetric cyanosilylation of acetophenone. It is shown that, in several cases, these discrete catalysts display dramatically different performances than the catalyst systems in situ -generated from the binary combinations. The influence of the achiral ligand X on both the enantioselectivity and activity of the cyanosilylation reaction has been investigated, resulting in the definition of a highly active and productive hexafluoro-2-propoxide-based catalyst for a variety of aryl alkyl ketones (TON up to 470, TOF up to 140,h,1 at ,20,°C for acetophenone). [source] The Immobilization of Rhodium-4-(diphenylphosphino)-2- (diphenylphosphinomethyl)-pyrrolidine (Rh-PPM) Complexes: A Systematic StudyADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12-13 2006Benoît Pugin Abstract A modular toolbox for the immobilization of homogeneous catalysts to various supports is described. It consists of functionalized chiral diphosphines and three different linkers based on isocyanate chemistry and it is used to attach the 4-(diphenylphosphino)-2-(diphenylphosphinomethyl)-pyrrolidine (PPM) ligand to a large variety of soluble, swellable and non-swellable solid organic polymers and to silica gels. As model reaction the hydrogenation of acetamidocinnamic acid derivatives, catalyzed with high enantioselectivity was chosen. Besides information on the usefulness of a particular type of support for synthetic applications, the experiments were also designed to address the question how parameters such as solubility, swellability, cage or pore size and solvent affect the rate and enantioselectivity of an immobilized catalyst. Rhodium complexes of ligands attached to soluble polymers and inorganic supports achieved ees up to 95,% and turnover frequencies between 700 and 1400,h,1, very close to the values of the homogeneous Rh catalyst (ee 95,%, TOF 1320,h,1). Insoluble or strongly cross-linked organic polymers led to catalysts with lower enantioselectivity and activity. PPM ligands attached to water soluble dendrimer fragments allowed hydrogenation in water solution with ees up to 94,%, albeit with much lower activity compared to reactions in methanol with the homogeneous catalyst. [source] Improved Turnover Numbers in Palladium-Catalyzed Bisdiene Cyclization-Trapping using N-Heterocyclic Carbene LigandsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 15 2005James Abstract An optimized palladium-N-heterocyclic carbene catalyst system effects the palladium-catalyzed bisdiene cyclization-trapping with phenol at the 0.01% catalyst loading level with a TON of 7.6×103 and TOF of 280,h,1, values much higher than typically found for this and related carbocyclizations. The reaction scales well and the trans -substituted six-membered ring product is obtained in excellent yield on a 10-mmole scale without further optimization of the catalyst system or reaction conditions. [source] Alternating Copolymerization of Cyclohexene Oxide and CO2 Catalyzed by Zinc Complexes with New 3-Amino-2-cyanoimidoacrylate LigandsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2005Mario Kröger Abstract New 3-amino-2-cyanoimidoacrylate ligands with varying steric demands have been synthesized. Zinc acetate complexes of these ligands catalyze the copolymerisation of CO2 and cyclohexene oxide, showing high activities (TOF up to over 200,h,1). [source] Diphosphines of dppf-Type Incorporating Electron-Withdrawing Furyl Moieties Substantially Improve the Palladium-Catalysed Amination of Allyl AcetatesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Aziz Fihri Abstract Highly active Pd/diphosphine catalytic systems incorporating new, air-stable ferrocenyl-furylphosphines allow nucleophilic allylic amination at room temperature with unprecedented turnover frequencies. For instance, in the presence of 0.01,mol,% catalyst the coupling of aniline to allyl acetate occurs at a TOF of more than 10,000,h,1; even the addition of the less nucleophile morpholine to allyl acetate is observed with a TOF of 4250,h,1. The amination of the sterically demanding geranyl acetate, a monoterpene derivative of interest in the flavour industry, at low catalyst loadings demonstrates the scope of this methodology, which provides in addition noticeable advantages in terms of economical (resource- and energy-saving) and sustainable chemistry (high selectivity, no additive, low metal content, and thus easier purification). [source] A single-crystal time-of-flight neutron diffractometer at a spallation neutron sourceJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2007Miwako Takahashi A single-crystal diffractometer using the time-of-flight (TOF) Laue technique had been operated for studies of structural and magnetic disorder and phase transitions in alloys and magnetic materials at the pulsed spallation neutron source facility of the KEK Neutron Science Laboratory (KENS). In various sample environments, the diffractometer has demonstrated its usefulness in measurements of diffuse scattering for studying local structures, and in surveys of reciprocal space for studying phase transitions and incommensurate structures under the conditions of varying temperature and magnetic field. Particular emphasis is placed on the fact that though the instrument did not receive high-flux neutrons for long wavelengths suitable for the studies of magnetic scattering, it gave good results on the observations of magnetic diffuse scattering and superlattice reflections. Remarks and future tasks of the TOF Laue technique are discussed in relation to the asymmetric pulse shape, separation of the inelastic scattering, and dependence of data correction on the sample quality. [source] Infusion requirements and reversibility of rocuronium at the corrugator supercilii and adductor pollicis musclesACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2009T. SUZUKI Background: The aim of this study is to compare the infusion rates required to maintain a constant neuromuscular block and the reversibility of rocuronium at the corrugator supercilii muscle (CSM) and the adductor pollicis muscle (APM). Methods: We randomly allocated 30 female patients into two groups of 15 patients each to monitor neuromuscular block at either the CSM or the APM. After induction of anaesthesia and laryngeal mask insertion, contraction of the CSM to the facial nerve stimulation or that of the APM to the ulnar nerve stimulation was quantified using an acceleromyograph during 1.0,1.5% end-tidal sevoflurane anaesthesia. All the patients received a bolus of 1 mg/kg rocuronium. When the first twitch (T1) of train-of-four (TOF) recovered to 10% of the control, rocuronium infusion was commenced and maintained at T1 of 10% of the control at the CSM or APM for 120 min. Immediately after rocuronium infusion was discontinued, the time required for 0.04 mg/kg neostigmine-facilitated recovery to a TOF ratio of 0.9 was recorded. Results: Rocuronium infusion dose after a lapse of 120 min was significantly larger in the CSM than in the APM [7.1 (2.3) vs. 4.7 (2.6) ,g/kg/min; P=0.001]. The time for facilitated recovery was shorter in the CSM than in the APM [11.4 (3.8) vs. 16.2 (6.0) min; P=0.016]. Conclusion: A larger rocuronium infusion dose was required to maintain a constant neuromuscular block at the CSM. Neostigmine-mediated reversal was faster at the CSM. [source] Current Strategy of Repair of Tetralogy of Fallot in Children and Adults: Emphasis on a New Technique to Create a Monocusp-Patch for Reconstruction of the Right Ventricular Outflow TractJOURNAL OF CARDIAC SURGERY, Issue 6 2008D.Sc., Guo-Wei He M.D., Ph.D. Methods: From 2001 through 2005, 74 patients (50 male, 24 female; mean age of 13.6 ± 0.8 years, ranging from four to 34 years) with TOF (67) or double outlet RV (DORV)-type-TOF (seven) underwent complete repair. The resection of RVOT stenosis ± pulmonary valvotomy was principally through RA. A new two-patch technique to create a folded mono-cusp valve by using autologous pericardium was applied since August 2004. Results: The repair was through RA in 52 patients and through RA + RVOT/PA in 22 patients (18/4). TAPR was performed in 17 patients (23%, eight non-valved and nine valved). The aortic cross-clamp time was 130.1 ± 6.8 min in TAPR group and 85.8 ± 4.6 min in non-TAPR group (p < 0.0001). The operative mortality was 4.0% (3/74) in all and 2.9% (2/67) in TOF patients (due to low output, uncontrollable bleeding, and repeated bleeding from the pulmonary collateral vessels late) and was similar in TAPR or non-TAPR. The valved patch-repaired patients had mild PI and good RV function postoperatively up to eight to 12 months. Conclusions: Repair of TOF in older children/adults should include low rate of TAPR of RVOT. If indicated, the new folded monocusp-patch technique is recommended. It is an effective and simple way to markedly reduce postoperative PI with no additional cost. [source] Repair of Complete Atrioventricular Septal Defect with Tetralogy of Fallot:JOURNAL OF CARDIAC SURGERY, Issue 2 2004Literature Review, Our Experience Materials and Methods: Between January 1990 and January 2002, 17 consecutive children with CAVSD-TOF underwent complete correction. Nine patients (53%) underwent previous palliation. Mean age at repair was 2.9 ± 1.9 years. Mean gradient across the right ventricular outflow tract was 63 ± 16 mmHg. All children underwent closure of septal defect with a one-patch technique, employing autologous pericardial patch. Maximal tissue was preserved for LAVV reconstruction by making these incisions along the RV aspect of the ventricular septal crest. LAVV annuloplasty was performed in 10 (59%) patients. Six patients (35%) required a transannular patch. Results: Three (17.6%) hospital deaths occurred in this series. Causes of death included progressive heart failure in two patients and multiple organ failure in the other patient. Two patients required mediastinal exploration due to significant bleeding. Dysrhythmias were identified in 4 of 11 patients undergoing a right ventriculotomy versus none of the patients undergoing a transatrial transpulmonary approach (p = ns). The mean intensive care unit stay was 3.2 ± 2.4 days. Two patients required late reoperation due to severe LAVV regurgitation at 8.5 and 21 months, respectively, after the intracardiac complete repair. The mean follow-up time was 36 ± 34 months. All patients survived and are in NYHA functional class I or II. The LAVV regurgitation grade at follow-up was significantly lower than soon after operation, 1.1 ± 0.4 versus 1.7 ± 0.5 (p = 0.002). At follow-up, the mean gradient across the right ventricular outflow tract was 17 ± 6 mmHg, significantly lower than preoperatively (p < 0.001). Conclusions: Complete repair in patients with CAVSD-TOF seems to offer acceptable early and mid-term outcome in terms of mortality, morbidity, and reoperation rate. Palliation prior to complete repair may be reserved in specific cases presenting small pulmonary arteries or severely cyanotic neonates. The RVOT should be managed in the same fashion as for isolated TOF; however, a transatrial transpulmonary approach is our approach of choice. (J Card Surg 2004;19:175-183) [source] The Results of Probe Technique for Transatrial Repair of Tetralogy of FallotJOURNAL OF CARDIAC SURGERY, Issue 6 2002Ahmet Turan Yilmaz M.D. The most critical point in transatrial repair of TOF is infundibular dissection. Right atrial approach provides better surgical exposure for parietal extension of the infundibular septum when compared to a right ventricular approach. However, it is not always easy to determine the localization and amount of muscle bundles to be resected and this surgical maneuver requires experience. Methods: Nineteen patients were reviewed who had repair of isolated TOF by this technique from 1993 to 2001. The mean age of patients was 5 ± 2 years . Transatrial-transpulmonary approach was performed for all patients. To make the infundibular muscle-bundle resection easier and to determine the localization and amount of muscle bundle to be resected, we placed a Hegar dilator into the right ventricle through pulmonary arteriotomy. The muscle bundles between the dilator and the anterior leaflet annulus of the tricuspid valve were totally excised until the intraventricular part of the dilator and pulmonary annulus became completely visible. The area between the Hegar dilator and the margins of the ventricular septal defect (VSD) was left untouched. None of the patients had transannular patch. Tricuspid valve detachment in order to improve the exposure was done in 11 patients. All patients were followed up in our clinic at regular six-month intervals by echocardiography. Results: There was no early or late mortality nor reoperation for residual VSD or residual right ventricle (RV) outflow obstruction. All patients were in NYHA class I. RV on the echocardiography was spared late dilatation and had a good late functional status. Eighteen patients had no or mild pulmonary regurgitation. One patient who had undergone tricuspid anterior leaflet detachment showed mild tricuspid insufficiency. Conclusions: On the basis of hemodynamic outcomes, this procedure for elective repair of TOF in selected cases gives excellent early and mid-term results.(J Card Surg 2002;17:490-494) [source] MRA of intracranial aneurysms embolized with platinum coils: A vascular phantom study at 1.5T and 3TJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2008Shingo Kakeda Abstract Purpose To analyze the influence of matrix and echo time (TE) of three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) on the depiction of residual flow in aneurysms embolized with platinum coils at 1.5T and 3T. Materials and Methods A simulated intracranial aneurysm of the vascular phantom was loosely packed to maintain the patency of some residual aneurysmal lumen with platinum coils and connected to an electromagnetic flow pump with pulsatile flow. MRAs were obtained altering the matrix and TE of 3D TOF sequences at 1.5T and 3T. Results The increased spatial resolution and the shorter TE offered better image quality at 3T. For the depiction of an aneurysm remnant, the high-spatial-resolution 3T MRA (matrix size of 384 × 224 and 512 × 256) with a short TE of ,3.3 msec were superior to the 1.5T MRA obtained with any sequences. Conclusion 3T MRA is superior to 1.5T MRA for the assessment of aneurysms embolized with platinum coils; the combination of the 512 × 256 matrix and short TE (3.3 msec or less) seems feasible at 3T. J. Magn. Reson. Imaging 2008;28:13,20. © 2008 Wiley-Liss, Inc. [source] In vivo MR imaging of pulmonary arteries of normal and experimental emboli in small animalsJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2006Mathieu Lederlin MD Abstract Purpose To demonstrate the feasibility of pulmonary MRA in living rodents. Materials and Methods A three-dimensional (3D) gradient echo sequence was adapted to perform a time-of-flight (TOF) angiography of rat lung. Angiogram with a spatial resolution of 195 × 228 × 228 ,m3 was acquired in around 33 minutes. The method was then applied in animals before and after pulmonary embolism (PE) induction. Section of the proximal right pulmonary artery was measured and compared between the two populations. Results Good quality images were obtained with a contrast-to-noise ratio (CNR) of 9 ± 3 in the proximal part of the pulmonary artery. Cross-section areas of the right main artery are statistically different before (3.45 ± 0.69 mm2) and after induction of PE (4.3 ± 0.86 mm2). Conclusion This noninvasive tool permits angiogram acquisition at around 200 ,m spatial resolution and objective distinction between healthy and embolized arteries. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] MR angiography fusion technique for treatment planning of intracranial arteriovenous malformationsJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2006Kiaran P. McGee PhD Abstract Purpose To develop an image fusion technique using elliptical centric contrast-enhanced (CE) MR angiography (MRA) and three-dimensional (3D) time-of-flight (TOF) acquisitions for radiosurgery treatment planning of arteriovenous malformations (AVMs). Materials and Methods CE and 3D-TOF MR angiograms with disparate in-plane fields of view (FOVs) were acquired, followed by k-space reformatting to provide equal voxel dimensions. Spatial domain addition was performed to provide a third, fused data volume. Spatial distortion was evaluated on an MRA phantom and provided slice-dependent and global distortion along the three physical dimensions of the MR scanner. In vivo validation was performed on 10 patients with intracranial AVMs prior to their conventional angiogram on the day of gamma knife radiosurgery. Results Spatial distortion in the phantom within a volume of 14 × 14 × 3.2 cm3 was less than ±1 mm (±1 standard deviation (SD)) for CE and 3D-TOF data sets. Fused data volumes were successfully generated for all 10 patients. Conclusion Image fusion can be used to obtain high-resolution CE-MRA images of intracranial AVMs while keeping the fiducial markers needed for gamma knife radiosurgery planning. The spatial fidelity of these data is within the tolerance acceptable for daily quality control (QC) purposes and gamma knife treatment planning. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Metal ion attachment to the matrix meso-tetrakis(pentafluorophenyl)porphyrin, related matrices and analytes: an experimental and theoretical study,JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 11 2009Jeroen J. A. van Kampen Abstract In a previous study [van Kampen et al.Analytical Chemistry 2006; 78: 5403], we found that meso-tetrakis (pentafluorophenyl)porphyrin (F20TPP), in combination with lithium salts, provides an efficient matrix to cationize small molecules by Li+ attachment and that this combination can be successfully applied to the quantitative analysis of drugs, such as antiretroviral compounds using matrix-assisted laser desorption ionization in conjunction with a time-of-flight analyzer (MALDI,TOF). In the present study, we further explore the mechanism of metal ion attachment to F20TPP and analytes by MALDI,FTMS(/MS). To this end, we have studied the interaction of F20TPP and analytes with various mono-, di- and trivalent metal ions (Li+, Na+, K+, Rb+, Cs+, Co2+, Cu2+, Zn2+, Fe2+, Fe3+ and Ga3+). For the alkali cations, we find that F20TPP forms complexes only with Li+ and Na+; in addition, model analyte molecules such as poly(ethyleneglycol)s, mixed with F20TPP and the alkali cations, also only form Li+ and Na+ adducts. This contrasts sharply with the commonly used matrix 2,5-dihydroxybenzoic acid, where analytes are most efficiently cationized by Na+ or K+. Reasons for this difference are delineated. Ab initio calculations on porphyrin itself reveal that even the smallest alkali cation, Li+, does not fit in the porphyrin cavity, but lies on top of it, pushing the 21H and 23 H hydrogen atoms out of and below the plane with concomitant bending of the porphyrin skeleton in the opposite direction, i.e. toward the cation. Thus, the Li+ ion is not effectively sequestered and is in fact exposed and thus accessible for donation to analyte molecules. Interaction of F20TPP with di- and trivalent metal ions leads to protoporphyrin,metal ions, where the metal ion is captured within the protoporphyrin dianion cavity. The most intense signal is obtained when F20TPP is reacted with CuCl2 and then subjected to laser ablation. This method presents an easy general route to study the metal containing protoporphyrin molecules, which could all act as potential MALDI matrices. Copyright © 2009 John Wiley & Sons, Ltd. [source] From large analogical instruments to small digital black boxes: 40 years of progress in mass spectrometry and its role in proteomics.JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 8 2009Part II 198 Abstract This is the continuation of a personal retrospective on the developments that since 1965 have given shape to Mass Spectrometry (MS) and taken it from a position of simply playing a role in Protein Chemistry to becoming an indispensable tool in Proteomics, all within a 40-year span. Part I covered the period from 1965 to 1984. This second part reviews the Mass Spectrometry timeline of events from 1985 to 2000, stopping at various time points where MS made significant contributions to protein chemistry or where the development of new instrumentation for MS represented a major advance for peptide and protein work. Major highlights in the field and their significance for peptide and protein characterization such as the advent and practical consequences of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) are covered, including work done with triple quads, the development of time-of-flight (TOF) instruments and new ion traps and going on to the more recent work on the full characterization of the Proteome with ion traps, TOF instruments and new ionization and tagging techniques for protein sequencing. Copyright © 2009 John Wiley & Sons, Ltd. [source] Modern MALDI time-of-flight mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 3 2009Marvin L. Vestal Abstract This paper focuses on development of time-of-flight (TOF) mass spectrometry in response to the invention of matrix-assisted laser desorption/ionization (MALDI). Before this breakthrough ionization technique for nonvolatile molecules, TOF was generally considered as a useful tool for exotic studies of ion properties but was not widely applied to analytical problems. Improved TOF instruments and software that allow the full potential power of MALDI to be applied to difficult biological applications are described. A theoretical approach to the design and optimization of MALDI-TOF instruments for particular applications is presented. Experimental data are provided that are in excellent agreement with theoretical predictions of resolving power and mass accuracy. Data on sensitivity and dynamic range using kilohertz laser rates are also summarized. These results indicate that combinations of high-performance MALDI-TOF and TOF-TOF with off-line high-capacity separations may ultimately provide throughput and dynamic range several orders of magnitude greater than those currently available with electrospray LC-MS and MS-MS. Copyright © 2009 John Wiley & Sons, Ltd. [source] In situ diagnostics of the decomposition of silacyclobutane on a hot filament by vacuum ultraviolet laser ionization mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 5 2007Y. J. Shi Abstract The gas-phase reaction products of silacyclobutane (SCB) and 1, 1-dideuterio-silacyclobutane (SCB- d2) from a hot-wire chemical vapor deposition (HWCVD) chamber were diagnosed in situ using vacuum ultraviolet (VUV) laser single-photon ionization (SPI) coupled with time-of-flight (TOF) mass spectrometry. The SCB molecule was found to decompose at a filament temperature as low as 900 °C. Both Si- (silylene, methylsilylene, and silene) and C-containing (ethene and propene) species were produced from the SCB decomposition on the filament. Ethene and propene were detected by the mass spectrometer. It is demonstrated that the formation of ethene is favored over that of propene. The experimental study of hot-wire decomposition of SCB- d2 shows that propene is most likely produced by a process that is initiated by a 1,2-H(D) migration to form n -propylsilylene, followed by an equilibration with silacyclopropane, which then decomposes to propene. The detection of ethene in our experiment indicates that a competitive route of fragmentation exists for SCB decomposition on the filament. It has been shown that this competitive route occurs without H/D scrambling. The highly reactive silylene, silene, and methylsilylene species produced from SCB decomposition underwent either insertion reactions into the SiH bonds of the parent molecule or ,-type addition reaction across the double and triple CC bonds. The dimerization product of silene, 1,3-disilacyclobutane, at m/z = 88 was also observed. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||