bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Highly Stereoselective Hydrogenation of the Statin Precursor Ethyl (5S)‐5,6‐Isopropylidenedioxy‐3‐oxohexanoate
Authors: Tararov Vitali I. , König Gerd , Börner Armin 
Published: November 2006

AbstractA search for the large‐scale preparation of (5S)‐5,6‐(isopropylidenedioxy)‐3‐oxohexanoates (2) – a key intermediate in the synthesis of pharmacologially important statins – starting from (S)‐malic acid is described. The synthesis of the required initial compound methyl (3S)‐3,4‐(isopropylidenedioxy)butanoate (1) by Moriwake’s reduction of dimethyl (S)‐malate (3) has been improved. Direct 2‐C chain elongation of ester 1 using the lithium enolate of tert‐butyl acetate has been shown to be successful at a 3‐ to 5‐fold excess of the enolate. Unfortunately, the product, tert‐butyl (5S)‐5,6‐(isopropylidenedioxy)‐3‐oxohexanoate (2a) is unstable during distillation. Ethyl (5S)‐5,6‐(isopropylidenedioxy)‐3‐oxohexanoate (2b) was prepared alternatively on a multigram scale from (3S)‐3,4‐(isopropylidenedioxy)butanoic acid (7) by activation with N,N′‐carbonyldiimidazole and subsequent reaction with Mg(OOCCH2COOEt)2. A convenient pathway for the in situ preparation of the latter is also described. Ethyl ester (2b) can be advantageously purified by distillation. The stereochemistry of the catalytic hydrogenation of β‐keto ester (2b) to ethyl (5S)‐5,6‐(isopropylidenedioxy)‐3‐hydrohyhexanoate (syn‐6 and anti‐6) has been studied using a number of homogeneous achiral and chiral Rh(I) and Ru(II) complexes with phosphine ligands. A comparison of Rh(I) and Ru(II) catalysts with (S)‐ and (R)‐BINAP as chiral ligands revealed opposite activity in dependence on the polarity of the solvent. No influence of the chiral backbone of substrate 2b on the enantioselectivity was noted. A ratio of syn‐6/anti‐6=2.3 was observed with an achiral (Ph3P)3RuCl2 catalyst. Ru[(R)‐Tol‐BINAP]Cl2 neutralized with one equivalent of AcONa afforded the most efficient catalytic system for the production of optically pure syn‐(5S)‐5,6‐isopropylidenedioxy‐3‐hydroxyhexanoate (syn‐6) at a preparative substrate/catalyst ratio of 1000:1.
Enantioselective 1,3‐Dipolar Cycloaddition of Nitrile Imines to α‐Substituted and α,β‐Disubstituted α,β‐Unsaturated Carbonyl Substrates: A Method for Synthesizing Dihydropyrazoles Bearing a Chiral Quaternary Center
Authors: Sibi Mukund P. , Stanley Levi M. , Soeta Takahiro 
Published: November 2006

AbstractDihydropyrazoles bearing a chiral quaternary center at the 5‐position have been prepared by enantioselective 1,3‐dipolar cycloaddition of nitrile imines to α‐substituted‐ and α,β‐disubstituted‐α,β‐unsaturated carbonyl substrates. Use of α,β‐unsaturated carbonyl substrates with a 1‐benzyl‐5,5‐dimethylpyrazolidin‐3‐one auxiliary in conjunction with MgI2 and a bisoxazoline ligand derived from (1R,2S)‐(+)‐cis‐1‐amino‐2‐indanol 6 proved optimal to obtain chiral dihydropyrazoles with high enantioselectivity (up to 99 % ee).
Acquired von Willebrand syndrome: An update
Authors: Franchini Massimo , Lippi Giuseppe 
Published: November 2006

AbstractAcquired von Willebrand syndrome (aVWS) is a rare bleeding disorder with laboratory findings similar to those for congenital von Willebrand disease (VWD). However, unlike congenital VWD, it arises in individuals with no personal or family history of bleeding. aVWS occurs in association with a variety of underlying disorders, most frequently in lymphoproliferative disorders, myeloproliferative disorders, and cardiovascular diseases. Through an analysis of the more recent literature data, the pathophysiology and the clinical, laboratory, and therapeutic aspects of this syndrome are concisely reported in this review. Am. J. Hematol., 2007. © 2006 Wiley‐Liss, Inc.
Clearance of the Janus kinase 2 (JAK2) V617F mutation after allogeneic stem cell transplantation in a patient with myelofibrosis with myeloid metaplasia
Authors: Ruiz‐Argüelles Guillermo J. , Garcés‐Eisele Javier , Reyes‐Núñez Virginia , Ruiz‐Delgado Guillermo J. , Rosillo Carlos , Camoriano John K. 
Published: November 2006

AbstractA patient with myelofibrosis with myeloid metaplasia displaying the V617F mutation of the JAK2 gene was given an allogeneic stem cell transplantation using a reduced‐intensity conditioning regimen. The patient engrafted, and as he became a chimera, the expression of the V617F mutation of the JAK2 gene decreased progressively until its disappearance. Accordingly, the concept of “molecular remission” of the myelofibrosis with myeloid metaplasia could be entertained and added to the categories of response to treatment which have been recently described. Am. J. Hematol., 2007. © 2006 Wiley‐Liss, Inc.
The study of sequence configuration and functional impact of the (AC)n(AT)xTy motif in human β‐globin gene promoter
Authors: Chan P.K. , Ma E.S.K. , Philipsen S. , Tan‐Un K.C. 
Published: November 2006

AbstractIn this report we examine the (AC)n(AT)xTy motif residing −530 bp 5′ upstream of the β‐globin gene in Chinese thalassaemic patients. This motif is a putative binding site for a repressor protein, termed beta protein 1 (BP1) (Berg et al., Nucleic Acids Res 1989;17:8833–8852). Variations in the (AC)n(AT)xTy repeats affect the binding affinity of BP1, thereby altering the expression of the β‐globin gene. Eight different configurations of this repeat motif are identified in our population of Chinese β‐thalassaemia patients. A (AC)3(AT)7T5 motif was identified among these thalassaemia patients and its influence in β‐globin gene expression was studied using stable transfection assay in murine erythroleukemia (MEL) cells. Our data demonstrated that the (AC)3(AT)7T5 motif has a moderately strong repressor effect on the expression of the cis‐linked β‐globin gene. The high affinity of BP1 for this motif may result in the suppression of the transcription of the β‐globin gene (Berg et al., Am J Hematol 1991;36:42–47). We postulate that silencer elements in the β‐globin promoter play an important role in modifying the clinical presentation of the disease. Am. J. Hematol., 2007. © 2006 Wiley‐Liss, Inc.
The high incidence of varicella herpes zoster with the use of bortezomib in 10 patients
Authors: Tong Yin , Qian Jie , Li Ying , Meng Hai , Jin Jie 
Published: November 2006

AbstractBortezomib, a proteasome inhibitor, has been used for patients with refractory and relapsed multiple myeloma, lymphoma and leukemia. We used bortezomib in ten refractory or relapsed patients (seven of multiple myeloma, two of lymphoma and one of acute myeloblastic leukemia). Six out of ten (60%) patients developed varicella herpes zoster after the complete of one cycle of bortezomib. The incidence of varicella herpes zoster was higher than reported in the literature. It may be due to immunosuppression caused by the combination of high‐dose dexamethasone or other drugs. We considered that prophylactic antiviral medication could be used in predisposed patients to reduce the incidence of varicella herpes zoster. Am. J. Hematol., 2007. © 2006 Wiley‐Liss, Inc.
Morphometric estimation of torsional stiffness and strength in primate mandibles
Authors: Daegling David J. 
Published: November 2006

AbstractIn comparative studies of masticatory function and mandibular biomechanics, the mediolateral dimension of the postcanine corpus (corpus breadth) is commonly utilized as a measure of torsional stiffness from which relative torsional strength is inferred. The use of this dimension entails certain assumptions about corpus shape and cortical bone distribution that are invalid. When corpus breadth is related to an appropriate, empirically supported measure of torsional strength, it is revealed that this dimension has limited utility for inference of biomechanical competence under torsion. The use of linear dimensions to infer structural adaptations to specific loading regimes is problematic given that bone tissue is not optimally deployed to minimize strain levels arising from isolated loads. For the inference of the masticatory biomechanical environment, the more reasonable approach is to consider overall size of the corpus (i.e., cross‐sectional area) for inference of intra‐ and inter‐specific differences in masticatory forces. Am J Phys Anthropol, 2007 © 2006 Wiley‐Liss, Inc.
No signature of Y chromosomal resemblance between possible descendants of the Cimbri in Denmark and Northern Italy
Authors: Børglum Anders D. , Vernesi Cristiano , Jensen Peter K.A. , Madsen Bo , Haagerup Annette , Barbujani Guido 
Published: November 2006

AbstractTwo European populations are believed to be related to the ancient Germanic tribe Cimbri: one living in Northern Italy, the other living in Jutland, Denmark. The people called Cimbri are documented in the ancient Roman historical record. Arriving from the far north their movements can be tracked from successive battles with the Romans. The Cimbri finally entered Italy from the northeast and were defeated at Vercellae (present day Vercelli) in 101 BC by Gaius Marius and his professional legions. Classical sources from the first centuries AD relate the homeland of the Cimbri to the coasts around the Elb estuary (northern Germany) or specifically towards the north (Himmerland in northern Jutland). In the alpine parts of Veneto, northeast of the historical battlefield, local traditions dating back to late medieval time, identify a local population as Cimbri living in Terra dei Cimbri. They are considered the descendents of the Germanic combatants that fled the battlefield at Vercelli. As the defeated Cimbri that possibly fled to the mountains of Northern Italy most likely would have been male (warriors), the present study investigated the possible Y chromosomal diversity of the two present populations using microsatellite markers and single nucleotide polymorphisms. While Cimbri from Himmerland resembled their geographical neighbors from Denmark for the Y‐chromosome markers, Cimbri from Italy were significantly differentiated both from Cimbri from Himmerland and from Danes. Therefore, we were not able to show any biological relationship for uniparentally transmitted markers. Am J Phys Anthropol, 2007 © 2006 Wiley‐Liss, Inc.
Demographic and evolutionary trajectories of the Guarani and Kaingang natives of Brazil
Authors: Marrero Andrea R. , Silva‐Junior Wilson A. , Bravi Cláudio M. , Hutz Mara H. , Petzl‐Erler Maria L. , Ruiz‐Linares Andres , Salzano Francisco M. , Bortolini Maria C. 
Published: November 2006

AbstractA total of 278 individuals from two Brazilian Indian tribes (Guarani and Kaingang) living in five different localities had their mitochondrial DNA sequenced for the first hypervariable segment (HVS‐I), and a fraction of them was also studied for seven biallelic Y‐chromosome polymorphisms. Nineteen HVS‐I lineages were detected, which showed distinct distributions in the two tribes. The GST value obtained with the mtDNA data is about 5 times higher for the Guarani as compared to the Kaingang, suggesting a higher level of differentiation between the three Guarani partialities than between the two Kaingang villages. Non‐Amerindian admixture varied with sex and in the Guarani was only observed through the paternal line. Using these data and those of other Tupian and Jêan tribes, it was possible to make inferences about past migratory movements and the genetic differentiation of these populations. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.
Genetic studies in French Guiana populations: Synthesis
Authors: Mazières Stéphane , Sevin André , Bonnet Françoise , Crubézy Eric , Salzano Francisco M. , Larrouy Georges 
Published: November 2006

AbstractTwelve blood group and protein systems from a total of 819 individuals from six tribal groups (Apalaí‐Wayana, Emerillon, Kaliña, Palikur Wayampi, and Wayana) living in French Guiana and Brazil were compared with each other and integrated with previous results from 17 other South Amerindian populations studied for the same genetic markers. Using correspondence analysis, map methodologies, and maximum linkage cluster analysis developed with the UPGMA method, we attempted to establish the genetic position of these tribes among South American Indians. Peripheral positions for the Emerillon and the Palikur were observed. Ethnohistorical data in French Guiana suggest that a strong founder effect for the former and endogamy for the latter could have generated the genetic differentiation of these two ethnic groups. However, when considered in a wider context, all French Guiana Natives cluster together in an intermediate position as compared with 17 other Amerindian groups studied for the comparison. Am J Phys Anthropol, 2007. © 2006 Wiley‐Liss, Inc.
Gold Catalysis
Authors: Hashmi A. Stephen K. , Hutchings Graham J. 
Published: November 2006

AbstractCatalysis by gold has rapidly become a hot topic in chemistry, with a new discovery being made almost every week. Gold is equally effective as a heterogeneous or a homogeneous catalyst and in this Review we attempt to marry these two facets to demonstrate this new found and general efficacy of gold. The latest discoveries are placed within a historical context, but the main thrust is to highlight the new catalytic possibilities that gold‐catalyzed reactions currently offer the synthetic chemist, in particular in redox reactions and nucleophilic additions to π systems. Indeed gold has proved to be an effective catalyst for many reactions for which a catalyst had not been previously identified, and many new discoveries are still expected.
Binary biopolymeric beads of alginate and gelatin as potential adsorbent for removal of toxic Ni2+ ions: A dynamic and equilibrium study
Authors: Bajpai Jaya , Shrivastava Ruma , Bajpai A. K. 
Published: November 2006

AbstractBinary biopolymeric beads of alginate and gelatin were prepared and characterized by IR spectral and scanning electron micrograph techniques. On to the surfaces of the prepared beads were performed static and dynamic adsorption studies of Ni2+ ions at fixed pH and ionic strength of the aqueous metal ion solutions. The adsorption data were applied to Langmuir and Freundlich isotherm equations and various static parameters were calculated. The dynamic nature of adsorption was quantified in terms of several kinetic constants such as rate constants for adsorption (k1), Lagergreen rate constant (kad), interparticle diffusion rate constant (kp), and pore diffusion coefficient (D). The influence of various experimental parameters such as solid to liquid ratio, pH, temperature, presence of salts, and chemical composition of biopolymeric beads on the adsorption of nickel ions was investigated. Various thermodynamic parameters were also calculated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2581–2590, 2007
Preparation of porous chitosan/agarose microsphere and its R‐phycoerythrin release properties
Authors: Xue Zhi‐Xin , Yang Gui‐Peng , Wang Guang‐Ce , Niu Jian‐Feng , Cao Xiao‐Yan 
Published: November 2006

AbstractThe chitosan microspheres (CS‐CL) were prepared by suspension crosslinking method and used as carriers of R‐phycoerythrin (R‐PE). In this study, R‐PE was loaded in the microspheres and released in vitro. The effects of pH value, temperature, ionic strength, and R‐PE concentration on loading efficiency and release behavior were discussed. A novel microsphere that contained agarose (CS‐AR MP) was prepared and the basic loading and releasing behavior for R‐PE of this kind of new microspheres were also investigated. The results showed that all these chitosan microspheres have the ability to control‐release R‐PE. The addition of agarose may somewhat accelerate the release rate of R‐PE from microspheres and reduce the capacity of adsorption for R‐PE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2759–2766, 2007
Influence of the cross‐sectional shape on the structure and properties of polyester fibers
Authors: Karaca Esra , Ozcelik Feryal 
Published: November 2006

AbstractThe effects of the fiber cross‐sectional shape on the structure and properties of polyester fibers were investigated. Fully drawn yarn (FDY) polyester fibers (167 dtex and 48 filaments) were produced under the same spinning conditions used in a spinning plant. The only difference between the fibers was their cross‐sectional shapes. Four different cross‐sectional shapes were chosen for the experimental work: round, hollow‐round, trilobal, and hollow‐trilobal. The crystallinity and values of the maximum stress, maximum strain, modulus, yield stress, shrinkage in boiling water, and unevenness of the fibers were determined. The difference in the cross‐sectional shapes influenced the modulus, maximum strain, yield stress, and shrinkage in boiling water. No effects on the crystallinity and maximum stress were observed. The results suggested that the hollow fibers had higher amorphous orientation than the full fibers. The hollow‐round fiber had the highest unevenness value. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2615–2621, 2007
Physical and electrochemical properties of low molecular weight poly(ethylene glycol)‐bridged polysilsesquioxane organic–inorganic composite electrolytes via sol–gel process
Authors: Yuan C. Y. , Chen S. Y. , Tang J. C. , Yang H. C. , Chen‐Yang Y. W. 
Published: November 2006

AbstractA new class of ionic conducting organic/inorganic hybrid composite electrolyte with high conductivity, better electrochemical stability and mechanical behavior was prepared through the sol–gel processing between ethylene‐bridged polysilsesquioxane and poly(ethylene glycol) (PEG). The composite electrolyte with 0.05 LiClO4 per PEG repeat unit has the best conductivity up to 10−4 S/cm at room temperature with the transference number up to 0.48 and an electrochemical stability window as high as 5.5 V versus Li/Li+. Moreover, the effect of the PEG chain length on the properties of the composite electrolyte has also been studied. The interactions between ions and polymer have also been investigated for the composite electrolyte in the presence of LiClO4 by means of FTIR, DSC, and TGA. The results indicated the interaction of Li+ ions with the ether oxygen of the PEG, and the formation of transient crosslinking with LiClO4, resulting in an increase of the Tg of the composite electrolyte. The VTF‐type behavior of the ionic conductivity implied that the diffusion of the charge carriers was assisted by the segmental motions of the polymer chains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2752–2758, 2007
Thermal and mechanical properties of poly(ε‐caprolactone) crosslinked with γ radiation in the presence of triallyl isocyanurate
Authors: Han Changyu , Ran Xianghai , Zhang Kunyu , Zhuang Yugang , Dong Lisong 
Published: November 2006

AbstractPoly(ϵ‐caprolactone) was crosslinked by γ radiation in the presence of triallyl isocyanurate. The influence of γ‐radiation crosslinking on the thermal and mechanical properties of poly(ϵ‐caprolactone)/triallyl isocyanurate was investigated. Differential scanning calorimetry analyses showed differences between the first and second scans. Dynamic mechanical analysis showed an increase in the glass‐transition temperature as a result of the radiation crosslinking of poly(ϵ‐caprolactone). Thermogravimetric analysis showed that γ‐radiation crosslinking slightly improved the thermal stability of poly(ϵ‐caprolactone). The γ radiation also strongly influenced the mechanical properties. At room temperature, crosslinking by radiation did not have a significant influence on the Young's modulus and yield stress of poly(ϵ‐caprolactone). However, the tensile strength at break and the elongation at break generally decreased with an increase in the crosslinking level. When the temperature was increased above the melting point, the tensile strength at break, elongation at break, and Young's modulus of poly(ϵ‐caprolactone) were also reduced with an increase in the crosslinking level. The yield stress disappeared as a result of the disappearance of the crystallites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2676–2681, 2007
Dielectric behavior of natural rubber composites in microwave fields
Authors: John Honey , Joseph Rani , Mathew K. T. 
Published: November 2006

AbstractIn this article, we report the preparation of conducting natural rubber (NR) with polyaniline (Pani). NR was made into a conductive material by the compounding of NR with Pani in powder form. NR latex was made into a conductive material by the in situ polymerization of aniline in the presence of NR latex. Different compositions of Pani–NR semi‐interpenetrating networks were prepared, and the dielectric properties of all of the samples were determined in microwave frequencies. The cavity perturbation technique was used for this study. A HP8510 vector network analyzer with a rectangular cavity resonator was used for this study. S bands 2–4 GHz in frequency were used. Thermal studies were also carried out with thermogravimetric analysis and differential scanning calorimetry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2682–2686, 2007
Fabrication, structures, and properties of acrylonitrile/methyl acrylate copolymers and copolymers containing microencapsulated phase change materials
Authors: Han Na , Zhang Xing‐Xiang , Wang Xue‐Chen 
Published: November 2006

AbstractThe polyacrylonitrile‐methyl acrylate (AN/MA mole ratio 100/0–70/30) copolymers and copolymers (AN/MA mole ratio 85/15) containing up to 40 wt % of microencapsulated n‐octadecane (MicroPCMs) are synthesized in water. The MicroPCMs were incorporated at the step of polymerization. The effect of the MA mole ratio and MicroPCMs content on structures and properties of the copolymers were studied by using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR), scanning electronic microscope (SEM), differential scanning calorimetry (DSC), thermogravimetry analysis (TG), gel permeation chromatography (GPC), and X‐ray diffraction (XRD). The feeding ratio agreed well with the composition of the AN/MA copolymers. The copolymers are synthesized in the presence of MicroPCMs. The melting point moves to lower temperature (206°C), while the decomposition temperature moves to higher temperature (309°C) with increasing of the MA mole ratio and microcapsules content. The number–average molecular weight of the copolymer is ∼30,000. The crystallinity of the copolymer decreases with increasing of the MA mole ratio and microcapsules content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2776–2781, 2007
Ion‐exchange membrane based on poly(styrene sulfonic acid‐co‐n‐(2‐hydroxyethyl) acrylamide)
Authors: Tanigami Tetsuya , Iwata Hiroshi , Mori Takamasa 
Published: November 2006

AbstractA new ion‐exchange membrane was prepared by blending a copolymer of poly(styrene sulfonic acid‐co‐N‐(2‐hydroxyethyl) acrylamide) with poly(vinylidene fluoride). The dissolution of the copolymer into water was prevented by the crosslinked network formed by condensation reaction between N‐(2‐hydoroxyethyl) acrylamide (HEAA) units. The reaction was caused after film‐forming the blend. Swellability in water, ion‐exchange capacity, ion conductivity, and mechanical properties of the membrane were investigated and compared with those of a well‐known ion‐exchange membrane, Nafion 117. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2788–2796, 2007