bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Rare Earth Doping on the Catalytic Activity of Copper‐Containing Hydrotalcites in Phenol Hydroxylation
Authors: Chen Chunxia , Xu Chenghua , Feng Liangrong , Li Zijian , Suo Jishuan , Qiu Fali , Yang Yingchun 
Published: November 2005

AbstractThe copper‐containing hydrotalcites (Cu‐HTLcs) are synthesized under microwave irradiation, the effect of rare earth elements (RE) on the synthesis of Cu‐HTLcs, wherein RE stands for rare earth elements, e.g., La, Y, Sm and Ce, is also investigated in the present work. The hydrotalcite structure of the synthesized samples is verified by XRD and FT‐IR. The results of their catalytic performances in phenol hydroxylation show that the doped rare earth elements can promote the catalytic activity of Cu‐HTLcs, exhibiting a good trend as follows: La>Y>Sm>Ce. XPS results show that the Cu+ species are produced after the interaction of La‐Cu‐HTLcs with H2O2. Combining with the catalytic test results, we propose a new mechanism about the generation of HO. radicals in phenol hydroxylation, it is assumed that HO‐Cu+‐OH species are first formed by the reduction of HO‐Cu2+‐OH located in hydrotalcites in the presence of H2O2, and then react with H2O2 to give rise to HO. radicals.
Non‐Racemic Halohydrins via Biocatalytic Hydrogen‐Transfer Reduction of Halo‐Ketones and One‐Pot Cascade Reaction to Enantiopure Epoxides
Authors: Poessl Tina M. , Kosjek Birgit , Ellmer Ursula , Gruber Christian C. , Edegger Klaus , Faber Kurt , Hildebrandt Petra , Bornscheuer Uwe T. , Kroutil Wolfgang 
Published: November 2005

AbstractBiocatalytic hydrogen‐transfer reduction of α‐chloro‐ketones furnished non‐racemic chlorohydrins by employing either Rhodococcus ruber as lyophilized cell catalyst or an alcohol dehydrogenase preparation from Pseudomonas fluorescens DSM 50106 (PF‐ADH). For all substrates investigated, Rhodococcus ruber gave strictly the “Prelog” product, whereas PF‐ADH showed scattered stereopreference. One possibility for a follow‐up reaction of halohydrins is the ring closure to the corresponding epoxide. A novel “one pot‐one step strategy” was employed to obtain the enantiopure epoxide from the α‐chloro‐ketone in a cascade like fashion at pH>12 involving biocatalytic hydrogen transfer reduction and in situ chemo‐catalyzed ring closure.
Stereoselective Hydrogenation of Folic Acid Dimethyl Ester Benzenesulfonate: A New Access to Optically Pure L‐Tetrahydrofolic Acid
Authors: Groehn Viola , Moser Rudolf , Pugin Benoît 
Published: November 2005

AbstractFolic acid was converted to the corresponding dimethyl ester benzenesulfonate and stereoselectively hydrogenated in organic solvents. An extended screening with rhodium‐ and iridium‐diphosphine catalysts was performed. Under optimized conditions the asymmetric hydrogenation provided a solution of tetrahydrofolic acid dimethyl ester with up to 44% de. The de could be increased to 98% by fractional crystallization of L‐tetrahydrofolic acid dimethyl ester benzenesulfonate from the hydrogenation mixture. Hydrolysis of the ester afforded optically pure L‐tetrahydrofolic acid, which can be isolated or converted into its 5‐ or 10‐ or 5,10‐substituted derivatives.
Rhodium‐BisbenzodioxanPhos Complex‐Catalyzed Homogeneous Enantioselective Pauson–Khand‐Type Cyclization in Alcoholic Solvents
Authors: Kwong Fuk Yee , Lee Hang Wai , Qiu Liqin , Lam Wai Har , Li Yue‐Ming , Kwong Hoi Lun , Chan Albert S. C. 
Published: November 2005

AbstractThe chiral atropisomeric diphosphane ligand (S)‐BisbenzodioxanPhos was found to be highly effective in the co‐operative processeses of aldehyde decarbonylation and cascaded enantioselective Pauson–Khand‐type reactions. Various 1,6‐enynes were transformed to the corresponding bicyclic cyclopentenones in good yields and enantiomeric excesses (up to 96% ee). The attractive feature of this new Rh‐catalyzed homogeneous dual catalysis system is that the reaction can be performed in alcoholic solution.
Highly Enantioselective Iridium‐Catalyzed Hydrogenation of Quinoline Derivatives Using Chiral Phosphinite H8‐BINAPO
Authors: Lam Kim Hung , Xu Lijin , Feng Lichun , Fan Qing‐Hua , Lam Fuk Loi , Lo Wai‐hung , Chan Albert S. C. 
Published: November 2005

AbstractThe chiral diphosphinite H8‐BINAPO derived from H8‐BINOL has been used in the Ir‐catalyzed asymmetric hydrogenation of quinolines, and high enantioselectivity (up to 97% ee) was obtained. Immobilization of the iridium catalyst in poly(ethylene glycol) dimethyl ether (DMPEG) is also discussed. With DMPEG/hexane biphasic system, better enantioselectivities were obtained as compared to those observed in aprotic organic solvents.
A Na2WO4/H2WO4‐Based Highly Efficient Biphasic Catalyst towards Alkene Epoxidation, using Dihydrogen Peroxide as Oxidant
Authors: Maheswari Palanisamy Uma , de Hoog Paul , Hage Ronald , Gamez Patrick , Reedijk Jan 
Published: November 2005

AbstractThe tungsten‐containing biphasic catalytic system [Na2WO4/H2WO4/PTR/chloroacetic acid] effectively epoxidizes alkenes with 50% H2O2 as terminal oxidant, under organic solvent‐free conditions. The catalytic process is proposed to proceed via a dinuclear tungsten peroxo species with coordinated chloroacetic acid, as suggested by ESI‐MS measurements. The catalytic system is suggested to involve tungsten‐peroxo and/or peracetic acid type of epoxidation catalyzed by the tungsten(VI) in the presence of an organic acid and H2O2. The reaction conditions employed for various alkenes for epoxidation are mild compared to the earlier studies and result in high product selectivity and conversion rate.
Convenient Modular Syntheses of Fluorous Secondary Phosphines and Selected Derivatives
Authors: Emnet Charlotte , Tuba Róbert , Gladysz J. A. 
Published: November 2005

AbstractReactions of the fluorous primary phosphines Rfn(CH2)2PH2 [Rfn=(CF2)n−1CF3; n=6, 8, 10] and Rfn′CHCH2 [(n′=6, 8, 10) (1 : 1; THF, reflux) in the presence of AIBN give the title compounds [Rfn(CH2)2][Rfn′(CH2)2]PH [n/n′=6/6 (4, 55%), 8/8 (5, 58%), 10/10 (6, 53%), 8/6 (7, 52%), 10/8 (8, 51%)] as low‐melting white solids on up to 10‐g scales. The chiral tertiary phosphine [Rf6(CH2)2][Rf8(CH2)2][Rf10(CH2)2]P (9) is similarly prepared from 7 and Rf10CHCH2 in the presence of VAZO (neat, 100 °C; 67%). The reaction of 5 and THF⋅BH3 yields the phosphine borane 5⋅BH3 (95%). Additions of triphosgene [(CCl3O)2CO] to 5 or Rf8(CH2)2PH2 give [Rf8(CH2)2]2PCl or Rf8(CH2)2PCl2, which are characterized in situ. The CF3C6F11/toluene partition coefficients of 4–9 increase with the number and lengths of the Rfn segments.
Synthesis of GDP‐Fucose on a Soluble Support: A Donor Substrate for the Fucosyltransferases
Authors: Daniellou Richard , Le Narvor Christine 
Published: November 2005

AbstractThe synthesis of GDP‐fucose on a poly(ethylene glycol)‐based soluble support is described. Our strategy relies on the attachment of the 6‐deoxy‐6‐thio‐L‐galactose onto the polymer via a thioether linkage , and its conversion to GDP‐fucose using established methods. We thus obtained GDP‐fucose bound to the polymer that was tested as an acceptor for the recombinant fucosyltranferase FucT‐III.
Reaction rates in ultrasonic emulsions of dense carbon dioxide and water
Authors: Timko Michael T. , Smith Kenneth A. , Danheiser Rick L. , Steinfeld Jeffrey I. , Tester Jefferson W. 
Published: November 2005

AbstractPower ultrasound provides a surfactant‐free means of emulsifying dense near‐critical carbon dioxide and water. Droplet size distributions and volume fractions of the dispersed phases have been measured for acoustically formed emulsions. Hydrolysis rates were measured for a series of 7 benzoyl halides under both silent, phase‐separated conditions and for sonicated, emulsified conditions (30°C, 80 bar, 0.6 W/cm3, 20 kHz). Sonication always accelerated the overall hydrolysis rate, sometimes by as much as 200‐fold. Two physical models were developed to describe global kinetics: one for silent and one for sonicated conditions. The model for silent conditions agreed well with the available data set and suggested conditions under which reaction in the carbon dioxide phase (rather than the water phase) might become important. The model for sonicated conditions properly captured the trends in the data set and predicted the experimental results to within a factor of 2 in the worst case. Our analysis strongly suggests that ultrasound accelerates phase‐transfer reactions by increasing the water/carbon dioxide interfacial area. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Unusual cerebrotendinous xanthomatosis with fronto‐temporal dementia phenotype
Authors: Guyant‐Maréchal Lucie , Verrips Aad , Girard Carole , Wevers Ron A. , Zijlstra Fokje , Sistermans Erik , Vera Pierre , Campion Dominique , Hannequin Didier 
Published: November 2005

AbstractCerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disease caused by a deficiency of the mitochondrial enzyme 27‐sterol hydroxylase (CYP27). We report a 53‐year‐old man, with an unusual phenotype of CTX. He had xanthomas since adolescence. He had no mental retardation and developed at 44 years a progressive neuropsychiatric phenotype, suggestive of fronto‐temporal dementia according to clinical Neary criteria. Cataract and ataxia were absent. Cerebral MRI revealed diffuse hyperintense T2 abnormalities in the supratentorial white matter without cerebellar atrophy or lesions, while Technetium‐99m‐ECD brain SPECT revealed a severe cerebellar hypoperfusion. Serum cholestanol level was elevated with excessive urinary bile alcohols excretion. Mutation analysis revealed that he was compound heterozygous for two mutations in the CYP27A1 gene: 1016 C > T (exon 5) on one allele and a novel mutation, 1435C > G (exon 8) on the other allele. A follow‐up study was conducted to evaluate the effects of chenodeoxycholic acid (CDCA) and simvastatin treatment during 3 years. In spite of this treatment, cognitive functions declined but no other signs of neurological deterioration appeared. © 2005 Wiley‐Liss, Inc.
A family with Duane anomaly and distal limb abnormalities: A further family with the arthrogryposis‐ophthalmoplegia syndrome
Authors: McCann Emma , Fryer Alan E. , Newman William , Appleton Richard E. , Kohlhase Jürgen 
Published: November 2005

AbstractA two‐generation family is reported in which three members have Duane anomaly and distal limb abnormalities. All three affected have photopic electroretinogram responses that are abnormal or at the lower limit of the normal range with normal scotopic responses. Two affected family members also have hearing loss. The likeliest diagnosis is the syndrome listed as “arthrogryposis‐ophthalmoplegia syndrome” on the London Dysmorphology Database or as “arthrogryposis with oculomotor limitation and electroretinal abnormalities” or “oculomelic aplasia” in OMIM [MIM 108145]. In view of the similarities with Okihiro syndrome, a search for mutations within the SALL4 gene was undertaken, but none were identified. © 2005 Wiley‐Liss, Inc.
An Xq22.3 duplication detected by comparative genomic hybridization microarray (Array‐CGH) defines a new locus (FGS5) for FG syndrome
Authors: Jehee Fernanda Sarquis , Rosenberg Carla , Krepischi‐Santos Ana Cristina , Kok Fernando , Knijnenburg Jeroen , Froyen Guy , Vianna‐Morgante Angela M. , Opitz John M. , Passos‐Bueno Maria Rita 
Published: November 2005

AbstractFG syndrome is an X‐linked multiple congenital anomalies (MCA) syndrome. It has been mapped to four distinct loci FGS1‐4, through linkage analysis (Xq13, Xp22.3, and Xp11.4‐p11.3) and based on the breakpoints of an X chromosome inversion (Xq11:Xq28), but so far no gene has been identified. We describe a boy with FG syndrome who has an inherited duplication at band Xq22.3 detected by comparative genomic hybridization microarray (Array‐CGH). These duplication maps outside all four loci described so far for FG syndrome, representing therefore a new locus, which we propose to be called FGS5. MID2, a gene closely related to MID1, which is known to be mutated in Opitz G/BBB syndrome, maps within the duplicated segment of our patient. Since FG and Opitz G/BBB syndromes share many manifestations we considered MID2 a candidate gene for FG syndrome. We also discuss the involvement of other potential genes within the duplicated segment and its relationship with clinical symptoms of our patient, as well as the laboratory abnormalities found in his mother, a carrier of the duplication. © 2005 Wiley‐Liss, Inc.
Array‐based comparative genomic hybridization analysis of recurrent chromosome 15q rearrangements
Authors: Sahoo Trilochan , Shaw Chad A. , Young Andrew S. , Whitehouse Nathan L. , Schroer Richard J. , Stevenson Roger E. , Beaudet Arthur L. 
Published: November 2005

AbstractGenomic rearrangements of chromosome 15q11‐q13 cause diverse phenotypes including autism, Prader–Willi syndrome (PWS), and Angelman syndrome (AS). This region is subject to genomic imprinting and characterized by complex combinations of low copy repeat elements. Prader–Willi and Angelman syndrome are caused primarily by 15q11‐13 deletions of paternal and maternal origin, respectively. Autism is seen with maternal, but not paternal, interstitial duplications. Isodicentric 15q, most often of maternal origin, is associated with a complex phenotype often including autistic features. Limitations of conventional cytogenetic tests preclude a detailed analysis in most patients with 15q rearrangements. We have developed a microarray for comparative genomic hybridization utilizing 106 genomic clones from chromosome 15q to characterize this region. The array accurately localized all breakpoints associated with gains or losses on 15q. The results confirmed the location of the common breakpoints associated with interstitial deletions and duplications. The majority of idic(15q) chromosomes are comprised of symmetrical arms with four copies of the breakpoint 1 to breakpoint 5 region. Patients with less common breakpoints that are not distinguished by routine cytogenetic methods were more accurately characterized by array analysis. This microarray provides a detailed characterization for chromosomal abnormalities involving 15q11‐q14 and is useful for more precise genotype–phenotype correlations for autism, PWS, AS, and idic(15) syndrome. © 2005 Wiley‐Liss, Inc.
Changes in hair morphology of mucopolysaccharidosis I patients treated with recombinant human α‐L‐iduronidase (laronidase, Aldurazyme)
Authors: Kloska Anna , Bohdanowicz Jerzy , Konopa Grażyna , Tylki‐Szymńska Anna , Jakóbkiewicz‐Banecka Joanna , Czartoryska Barbara , Liberek Anna , Węgrzyn Alicja , Węgrzyn Grzegorz 
Published: November 2005

AbstractMucopolysaccharidoses (MPS) are heritable, metabolic diseases caused by accumulation of mucopolysaccharides (glycosaminoglycans, GAGs) in lysosomes. This accumulation is due to a deficiency in one of several specific enzymes involved in the degradation of GAGs. MPS type I (MPS I) is caused by low or undetectable activity of α‐L‐iduronidase, an enzyme involved in removing the terminal iduronic acid residues from heparan and dermatan sulfate. Recently, an enzyme replacement therapy (ERT) for MPS I, based on administration of recombinant human α‐L‐iduronidase (laronidase, Aldurazyme), became available. The assessment of efficacy of ERT is especially important because MPS I is a highly variable and very rare disease, and the clinical trials involved relatively low number of patients. Among various significant clinical improvements during ERT, remarkable changes in hair morphology were noted. Detailed studies of hair samples from one patient, who did not have a hair cut from the beginning of ERT to the end of this study, and supported by results obtained for two other patients, revealed hair shaft structural abnormalities in MPS I hair. These hair abnormalities disappeared upon treatment with Aldurazyme. Although hair morphology is of limited clinical importance, the data suggest that changes in this parameter could be a useful, additional tool for a rapid, non‐invasive, preliminary assessment of ERT efficacy. © 2005 Wiley‐Liss, Inc.
Analysis of polymorphisms in AT‐rich domains of neuregulin 1 gene in schizophrenia
Authors: Lachman Herbert M. , Pedrosa Erika , Nolan Karen A. , Glass Max , Ye Kenny , Saito Takuya 
Published: November 2005

AbstractLinkage analysis and association studies have pointed to neuregulin 1 (NRG1) as the prime candidate for 8p‐linked schizophrenia (SZ). However, so far, no specific functional alleles in the gene's exons, intron–exon junctions and promoters have been identified that are unequivocally associated with SZ. In this study, we analyzed several NRG1 polymorphisms that affect ATTT motifs and AT‐rich regions of the gene. We have previously identified a number of such polymorphisms in the promoters of other SZ and bipolar disorder (BD) candidate genes and found positive associations to several of them. In addition, allele specific differences in the binding of brain proteins have been found for many of the polymorphisms. A case control design was used to compare allele frequencies in Caucasian and African American patients with SZ and controls. In the African American group, a significant difference was found in the allele and genotype distribution for several of the markers and haplotype blocks located in the 5′‐ and 3′‐ends of the gene. The most significant result was obtained for rs6150532, an insertion/deletion variant in a conserved region of an intron that separates two small, alternatively spliced exons. Allele‐specific and developmental differences were detected in the binding of a brain protein using newborn rat pups when probes containing the two rs6150532 alleles were used in electromobility gel shift assays. There were no significant differences in allele or genotype distribution found for any of the markers in the Caucasian sample. Although the samples size is relatively small, the findings support a role for NRG1 in SZ in African Americans and suggest that polymorphic differences in regions of the gene that recognize AT‐binding proteins may be a factor in disease pathogenesis. © 2005 Wiley‐Liss, Inc.
Genetic etiology of stability of attention problems in young adulthood
Authors: van den Berg Stéphanie M. , Willemsen Gonneke , de Geus Eco J.C. , Boomsma Dorret I. 
Published: November 2005

AbstractVariation in attention problems in children and adolescents from non‐clinical samples is highly heritable. It is unknown how attention problems develop later in life and whether the heritability in the general adult population is the same as in children and adolescents. We assessed the heritability and stability of individual differences in attention problems in the general young adult population and explored to what extent the stability can be attributed to genetic or environmental factors. On one or more occasions, young adult twins (age range, 18–30 years, N = 4,245) from the Netherlands Twin Registry filled out the attention problems (AP) subscale of the Young Adult Self‐Report [Achenbach, 1997]: in 1991, N = 1,755 (of which 842 complete pairs), in 1995, N = 2,428 (1156 complete pairs) and in 1997, N = 2,344 (958 pairs). There was only a slight decrease in the average level of attention problems during young adulthood. The heritability at each occasion was around 40%. The correlation of attention problems across a period of 6 years was 0.42, and 77% of this correlation could be ascribed to genetic influences. Thus, individual differences in attention problems in young adulthood are heritable, and stability in individual differences over time can largely be ascribed to genetic influences. Genetic correlations across time were high, suggesting that the genes that influence variability in attention problems in late adolescence are largely the same as those that influence variability in early adulthood. © 2005 Wiley‐Liss, Inc.
Recent progress towards a molecular understanding of Marfan syndrome
Authors: Dietz Harry C. , Loeys Bart , Carta Luca , Ramirez Francesco 
Published: November 2005

AbstractMarfan syndrome (MFS) is a systemic disorder of the connective tissue that is inherited as an autosomal dominant trait and which displays variable manifestations in the ocular, skeletal, and cardiovascular systems. These pleiotropic manifestations are accounted for by mutations in fibrillin‐1, the building block of extracellular microfibrils. During the past 10 years, we have witnessed significant progress in delineating the pathological events responsible for the manifestations of MFS. Much of this progress has been based on the creation and analysis of fibrillin‐1 mutant mouse lines that faithfully recapitulate the spectrum of clinical severity of MFS. These studies have established the critical contribution of fibrillin‐1 deficiency to disease progression through altered cell–matrix interactions and dysregulated TGF‐β signaling. As a result, our definition of MFS as the prototypical structural disorder of the connective tissue has changed to that of a developmental abnormality with broad and complex effects on the morphogenesis and function of multiple organ systems. Importantly, new biological targets have emerged that may yield exciting new opportunities for the development of productive treatment strategies in MFS. © 2005 Wiley‐Liss, Inc.
Interleukin‐6 involvement in brain arteriovenous malformations
Authors: Chen Yongmei , Pawlikowska Ludmila , Yao Jianhua S. , Shen Fanxia , Zhai Wenwu , Achrol Achal S. , Lawton Michael T. , Kwok Pui‐Yan , Yang Guo‐Yuan , Young William L. 
Published: November 2005

AbstractWe recently reported that the GG genotype of the interleukin‐6 (IL‐6)–174G>C promoter polymorphism is associated with clinical presentation of intracranial hemorrhage in brain arteriovenous malformation (AVM) patients. In this study, we investigated whether tissue IL‐6 expression was associated with IL‐6–174G>C genotype, and whether IL‐6 was linked to downstream targets involved in angiogenesis and vascular instability. Our results showed that the highest IL‐6 protein levels in brain AVM tissue were associated with IL‐6–174GG genotype (GG: 57.7 ± 20.2; GC: 35.6 ± 26.6; CC: 13.9 ± 10.2pg/mg; p = 0.001). IL‐6 protein levels were increased in AVM tissue from patients with hemorrhagic presentation compared with patients without hemorrhage (55 ± 22 vs 40 ± 27pg/mg; p = 0.038). IL‐6 messenger RNA expression strongly correlated with messenger RNA levels of IL‐1β, tumor necrosis factor‐α, IL‐8, matrix metalloproteinase‐3 (MMP‐3), MMP‐9, and MMP‐12. We further investigated the plausibility of IL‐6 being an upstream cytokine responsible for initiating the angiogenic cascade by cell culture and animal experiments. IL‐6 induced MMP‐3 and MMP‐9 expression and activity in mouse brain and increased proliferation and migration of cerebral endothelial cells. Together, our results suggest that the IL‐6 genotype associated with intracranial hemorrhage modulates IL‐6 expression in brain AVM tissue, which is consistent with the hypothesis that inflammatory processes induce angiogenic activity possibly contributory to brain AVM intracranial hemorrhage. Ann Neurol 2005