bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stabilization and Destabilization of the Ru−CO Bond During the 2,2′‐Bipyridin‐6‐onato (bpyO)‐Localized Redox Reaction of [Ru(terpy)(bpyO)(CO)](PF6)
Authors: Tomon Takashi , Koizumi Take‐aki , Tanaka Koji 
Published: December 2004

AbstractTwo stereoisomers of [Ru(terpy)(bpyO)(CO)](PF6) ([1]+ and [2]+; terpy = 2,2′:6′,2′′‐terpyridine, bpyO = 2,2′‐bipyridin‐6‐onato) were prepared. The pyridonato moiety in the bpyO ligand of [1]+ and [2]+ is located trans and cis, respectively, to CO. Treatment of [1]+ and [2]+ with HPF6 produced [1H]2+ and [2H]2+, both of which contain bpyOH (bpyOH = 6‐hydroxy‐2,2′‐bipyridine). The difference in the pKa values of [1H]2+ (3.5) and [2H]2+ (3.9) reflects the stronger electronic interaction between CO and the pyridonato moiety in the bpyO ligand in the trans position compared with that in the cis position. The molecular structures of [1](PF6), [2](PF6)·H2O and [2H](PF6)2·2H2O were determined by X‐ray structure analyses. [1]+ and [2]+ undergo one, reversible reduction at E1/2 = −1.65 V and −1.51 V, respectively, and one irreversible reduction at Ep,c = −2.07 and Ep,c = −2.13 V, respectively. Both reductions are assigned to redox reactions localized at the terpy and bpyO ligands. Irreversible reduction of [1]0 results from reductive cleavage of the Ru−CO bond of [1]−. On the other hand, a two‐electron oxidation of [2]− almost regenerates [2]+ because of the depression of the reductive Ru−CO bond cleavage of [2]− due to cyclometalation formed by an attack of oxygen of bpyO to the carbon of the Ru−CO bond. An unusually large shift of the ν(C≡O) band on going from [2]0 (1950 cm−1) to [2]− (1587 cm−1) also supports a reversible cyclometalation driven by the bpyO‐localized redox reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
In Search of exo‐Selective Catalysts for Enantioselective 1,3‐Dipolar Cycloaddition between Acryloyloxazolidinone and Diphenylnitrone
Authors: Desimoni Giovanni , Faita Giuseppe , Mella Mariella , Boiocchi Massimo 
Published: December 2004

Abstract1,3‐Dipolar cycloaddition (1,3‐DC) between acryloyloxazolidone 1 and diphenylnitrone 2 was catalysed by complexes of three (4R)‐phenylbis(oxazolines) [box = bis(oxazolines)] − either 5‐unsubstituted (8a), or 4,5‐cis‐ and ‐trans‐diphenyl‐substituted (8b, 8c) − with several perchlorates of divalent cations. Normal endo selectivity was obtained with MgII‐ and NiII‐8a catalysts, and the formation of the endo enantiomers (3′R,4′S)‐ or (3′S,4′R)‐3 depended upon the presence of 4‐Å molecular sieves (MS). Different results were observed with the catalysts derived from this ligand and CoII or ZnII, which gave good levels of exo enantioselectivity, with 84% ee of (3′S,4′S)‐4. When 8c was used as ligand, MgII, CoII and NiII give exo‐selective catalysts, and the enantiomer (3′R,4′R)‐4 was obtained with good dr and excellent ee. The unknown absolute configuration of the exo enantiomers 4 was established by structure correlation with one exo diastereoisomer obtained from the 1,3‐DC between 2 and (S)‐3‐acryloyl‐4‐benzyl‐2‐oxazolidinone (10). The flexibility of the catalysts derived from box 8a and 8c, all with 4R configuration, is remarkable since a change in the cation allows the endo‐3 or the exo‐4 enantiomers to be obtained enantioselectively with ees in the 84−99% range. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Case‐control single‐marker and haplotypic association analysis of pedigree data
Authors: Browning Sharon R. , Briley J. David , Briley Linda P. , Chandra Gyan , Charnecki Jonathan H. , Ehm Margaret G. , Johansson Kelley A. , Jones Brendan J. , Karter Andrew J. , Yarnall David P. , Wagner Michael J. 
Published: December 2004

AbstractRelated individuals collected for use in linkage studies may be used in case‐control linkage disequilibrium analysis, provided one takes into account correlations between individuals due to identity‐by‐descent (IBD) sharing. We account for these correlations by calculating a weight for each individual. The weights are used in constructing a composite likelihood, which is maximized iteratively to form likelihood ratio tests for single‐marker and haplotypic associations. The method scales well with increasing pedigree size and complexity, and is applicable to both autosomal and X chromosomes. We apply the approach to an analysis of association between type 2 diabetes and single‐nucleotide polymorphism markers in the PPAR‐γ gene. Simulated data are used to check validity of the test and examine power. Analysis of related cases has better power than analysis of population‐based cases because of the increased frequencies of disease‐susceptibility alleles in pedigrees with multiple cases compared to the frequencies of these alleles in population‐based cases. Also, utilizing all cases in a pedigree rather than just one per pedigree improves power by increasing the effective sample size. We demonstrate that our method has power at least as great as that of several competing methods, while offering advantages in the ability to handle missing data and perform haplotypic analysis. Genet. Epidemiol. 28:110–122, 2005. © 2004 Wiley‐Liss, Inc.
Head structures of males of Strepsiptera (Hexapoda) with emphasis on basal splitting events within the order
Authors: Beutel Rolf Georg , Pohl Hans 
Published: December 2004

AbstractInternal and external head structures of males of Strepsiptera were examined and the head of a species of Mengenilla is described in detail. The results suggest a reinterpretation of some structures. The head of basal extant strepsipterans is subprognathous, whereas it is strictly orthognathous in the groundplan of Strepsiptera s.l. The labrum and hypopharynx are not part of the mouthfield sclerite. The labial palps are absent in all strepsipterans. A very slightly modified mandibular articulation is preserved in Eoxenos, whereas it is distinctly reduced in other extant groups. A salivary duct, salivary glands, and a cephalic aorta are absent. The cladistic analysis of 44 characters of the head results in the following branching pattern: (Protoxenos + (Mengea + (Eoxenos + (Mengenilla [Austr.] + Mengenilla) + (Elenchus + Dundoxenos + Xenos + Stylops)))). Most apomorphies of males are associated with the necessity of finding females within a short time span and with a reduced necessity to consume food: large “raspberry” eyes, flabellate antennae with numerous dome‐shaped chemoreceptors, Hofeneder's organ, an ovoid sensillum of the maxillary palp, and the simplified condition of the maxilla and the labium. Strepsiptera excl. Protoxenos are supported by the dorsomedian frontal impression, the dorsally shifted antennal insertions, a reduced number of antennal segments, absence of the galea, and probably by the presence of the mouthfield sclerite, which is a unique apomorphic feature. The balloon‐gut combined with an unusual air‐uptake apparatus is another possible autapomorphy of this clade. It is likely that the last common ancestor of Strepsiptera excl. Protoxenos did not process food. Strepsiptera s.str. are characterized by the strongly reduced condition of the labrum and the absence of the epistomal suture. Eoxenos is the sister group of the remaining Strepsiptera s.str. Synapomorphies of Mengenilla + Stylopidia are the advanced reduction of the mandibular articulation and the secondary absence of the ovoid sensillum. The monophyly of Mengenilla is confirmed, even though a small free labrum is present in Australian species. Derived features of Stylopidia are the absence of the coronal suture and the reduced condition of the frontal suture. Apomorphies that have evolved within Stylopidia are the membranization of parts of the head, the fusion of antennal segments, the increase or decrease of the number of flabellate flagellomeres, reductions and modifications of the mandibles, and modifications of the mouthfield sclerite. The monophyly of Stylopiformia is not unambiguously supported. A position of the mandibles posterior to the mouthfield sclerite (when adducted) is a possible synapomorphy shared by Xenos, Stylops, and other “higher Stylopidia.” The blade‐like distal part of the mandibles suggests a closer relationship of Elenchus with these taxa. © 2004 Wiley‐Liss, Inc.
Monocarboxylate transporter expression in the spontaneous hypertensive rat: Effect of stroke
Authors: Zhang Feng , Vannucci Susan J. , Philp Nancy J. , Simpson Ian A. 
Published: December 2004

AbstractThe expression of the monocarboxylate transporters (MCT) 1, 2, and 4 have been studied in the brains of spontaneous hypertensive (SH) rats after an ischemic insult induced by a permanent occlusion of the left middle cerebral artery (MCAO). Profound temporal changes in MCT1 expression were observed in various regions of the ipsilateral hemisphere over the period of 1 hr to 5 days after MCAO. Initially, a very rapid and transient increase in MCT1 mRNA was observed in neurons in the second layer of the cortex and in the piriform cortex at 1–3 hr. A slower but sustained increase in MCT1 mRNA expression was observed in astrocytes in the peri‐infarct region beginning at 6 hr after MCAO and persisting over a period of 120 hr coinciding with their activation, migration, and involvement in scar formation. An increase in MCT1 expression in endothelial cells was seen over the same period. These increases in MCT1 expression in astrocytes and endothelial cells were accompanied by a corresponding increase in MCT1 protein. Finally at 120 hr post‐MCAO, increases in MCT1, MCT2, and MCT4 expression were observed in cells within the infarct and bordering the scar, the identity of which remains to be determined. Consistent with cell death, the levels of MCT1, MCT2, and MCT4 mRNA decreased with cell death within the infarcted area but unlike MCT1, no increases in either MCT2 or 4 were observed within the remaining ipsilateral hemisphere. These studies reveal that the pattern of regulation of MCT1 expression after MCAO is similar to that observed previously for glucose transporter 1 (GLUT1) and suggest that the regulation of MCT1 mRNA expression is mediated by the hypoxia‐inducible transcription factor HIF1. © 2004 Wiley‐Liss, Inc.
Brain iron uptake in hypotransferrinemic mice: Influence of systemic iron status
Authors: Beard John L. , Wiesinger Jason A. , Li Nan , Connor James R. 
Published: December 2004

AbstractThe relationship of the heterogeneity of iron concentrations in the brain with the regulation of iron uptake into specific brain regions remains unresolved. We used hypotransferrinemic mice and an iron‐deficient or control diet to explore whether plasma transferrin (Tf), transferrin saturation, and plasma iron levels influence the uptake of 59Fe and whether there was brain region specificity. Weaning wild‐type (+/+) and heterozygotic mice (+/hpx), were sorted randomly to either a iron‐deficient diet or a control iron diet for 8 weeks, whereas homozygous mice (hpx/hpx) ate the control diet for 8 weeks before 59Fe uptake studies. Iron‐deficient heterozygous and wild‐type mice both had significantly greater plasma Tf levels (37.5 and 42.5 μM) than control mice had (heterozygous and wild‐type controls were 20 and 32.5 μM) and far more than homozygous mice (<0.2 μM) had, thus providing five distinct levels of plasma Tf concentrations. After intravenous injection of 59Fe, brains of iron‐deficient wild‐type mice took up significantly more 59Fe (0.15% dose) compared to control wild‐type mice (0.056%) at 2 hr, a treatment effect that persisted through 24 hr. In contrast, diet had no effect in heterozygous mice. Importantly, homozygous mice had equivalent uptake to other groups (0.089% dose) by 24 hr. Early brain radioactivity varied by regions (hypothalamus and prefrontal cortex ∼10–18% brain uptake > cerebellum, pons, thalamus, and striatum ∼7–12% > cortex, hippocampus, and substantia nigra ∼6–8%). This distribution of radioactivity changed over 24 hr in the hypothalamus of heterozygous mice, homozygous mice, and iron‐deficient wild‐type mice. Homozygous mice also showed higher uptake (13–15%) in some regions (hypothalamus and cerebellum) than in other regions. In wild‐type and heterozygous mice, 59Fe uptake was inversely related to brain Tf and was independent of regional brain iron concentrations and plasma Tf levels or saturation. These experimental data suggest that brain iron uptake may be constitutive and independent of plasma Tf, transferrin saturation, or regional brain iron concentration. The proteins and mechanisms responsible for additional iron uptake into specific regions, or perhaps the redistribution are unclear though the data are supportive of a non‐transferrin‐bound iron uptake pathway. © 2004 Wiley‐Liss, Inc.
Vitamin C uptake and recycling among normal and tumor cells from the central nervous system
Authors: Astuya Allisson , Caprile Teresa , Castro Maite , Salazar Katterine , García María de los Angeles , Reinicke Karin , Rodríguez Federico , Vera Juan Carlos , Millán Carola , Ulloa Viviana , Low Marcela , Martínez Fernando , Nualart Francisco 
Published: December 2004

AbstractSpecialized cells transport vitamin C in its reduced form using sodium‐dependent cotransporters (SVCT1 and SVCT2). Additionally, different cells transport the oxidized form of vitamin C, dehydroascorbic acid, through glucose transporters (GLUTs). We have proposed recently a model for vitamin C uptake that resolves the apparent contradiction that although only ascorbic acid is detectable in vivo, there are cells that transport only dehydroascorbic acid. We carried out a detailed kinetic analysis to compare the mechanisms of vitamin C uptake in normal human melanocytes, neurons isolated from brain cortex, hypothalamic ependymal‐glial cells, and astrocytes. Uptake of ascorbic acid was also analyzed in the human oligodendroglioma cell line TC620, in human choroid plexus papilloma cells (HCPPC‐1), and in the neuroblastoma cell line Neuro‐2a. Melanocytes were used to carry out a detailed analysis of vitamin C uptake. Analysis of the transport data by the Lineweaver‐Burk plot revealed the presence of one functional component (Km 20 μM) involved in ascorbic acid transport by melanocytes. Vitamin C sodium‐dependent saturable uptake was also observed in neurons and hypothalamic tanycytes. We confirmed SVCT2 expression in neurons by in situ hybridization; however, SVCT2 expression was not detected in astrocytes in situ. Functional data indicate that astrocytes transport mainly dehydroascorbic acid, using the glucose transporter GLUT1. Our functional uptake analyses support the hypothesis that astrocytes are involved in vitamin C recycling in the nervous system. This recycling model may work as an efficient system for the salvage of vitamin C by avoiding the hydrolysis of dehydroascorbic acid produced by antioxidative protection. © 2004 Wiley‐Liss, Inc.
Synthesis of polydimethylsiloxane‐block‐polystyrene‐block‐polydimethylsiloxane via polysiloxane‐based macroinitiator in supercritical CO2
Authors: Akgün Mesut , Deniz Sennur , Baran Nil , Uzun Nimet I , Akgün Nalan A , Dinçer Salih 
Published: December 2004

AbstractPolydimethylsiloxane‐block‐polystyrene‐block‐polydimethylsiloxane (PDMS‐b‐PS‐b‐PDMS) was synthesized by the radical polymerization of styrene using a polydimethylsiloxane‐based macroazoinitiator (PDMS MAI) in supercritical CO2. PDMS MAI was synthesized by reacting hydroxy‐terminated PDMS and 4,4′‐azobis(4‐cyanopentanoyl chloride) (ACPC) having a thermodegradable azo‐linkage at room temperature. The polymerization of styrene initiated by PDMS MAI was investigated in a batch system using supercritical CO2 as the reaction medium. PDMS MAI was found to behave as a polyazoinitiator for radical block copolymerization of styrene, but not as a surfactant. The response surface methodology was used to design the experiments. The parameters used were pressure, temperature, PDMS MAI concentration and reaction time. These parameters were investigated at three levels (−1, 0 and 1). The dependent variable was taken as the polymerization yield of styrene. PDMS MAI and PDMS‐b‐PS‐b‐PDMS copolymers obtained were characterized by proton nuclear magnetic resonance and infrared spectroscopy. The number‐ and weight‐average molecular weights of block copolymers were determined by gel permeation chromatography. Copyright © 2004 Society of Chemical Industry
Optical resolution of racemic amino acid derivatives with molecularly imprinted membranes bearing oligopeptide tweezers
Authors: Yoshikawa Masakazu , Koso Katsunori , Yonetani Kyoichi , Kitamura Satoshi , Kimura Satoshi 
Published: December 2004

AbstractMolecularly imprinted polymeric membranes were prepared from various oligopeptide tweezers by the adoption of N‐α‐tert‐butoxycarbonyl‐D‐tryptophan (Boc‐D‐Trp) or N‐α‐tert‐butoxycarbonyl‐L‐tryptophan (Boc‐L‐Trp) as a print molecule. The chiral recognition ability of the formed molecular recognition sites was dependent on the absolute configuration of the print molecule adopted in the membrane preparation (molecular imprinting) process, whereas the candidate oligopeptide tweezers consisted of the L‐amino acid residues. In other words, the membranes imprinted by the D‐isomer recognized the D‐isomer in preference to the corresponding L‐isomer, and vice versa. The affinity constant between the target molecule and the chiral recognition site from the oligopeptide tweezers was higher than that from a single‐strand oligopeptide derivative. Those membranes selectively transported the enantiomer, which was preferentially incorporated into the membrane by dialysis. The permselectivities for these membranes exceeded their adsorption selectivities. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 385–396, 2005
Efficacy and medical cost offset of psychosocial interventions in cancer care: Making the case for economic analyses
Authors: Carlson Linda E. , Bultz Barry D. 
Published: December 2004

AbstractThe burden of cancer in the worldwide context continues to grow, as incidence and mortality increase each year. Regardless of where they live, a significant proportion of cancer patients at all stages of the disease trajectory will suffer social, emotional and psychological morbidity as a result of their diagnosis and treatment. Psychosocial interventions have proven efficacious in helping patients and families overcome many of the challenges that arise consequent to a cancer diagnosis. Addressing psychosocial needs is an essential aspect of any model of adequate cancer care, however it may also prove to be a cornerstone in efforts to extend the reach of cost‐effective cancer treatment to meet the growing global need. In order to set the stage for discussion of economic issues, this paper first briefly reviews the literature detailing the extent of distress and the efficacy of psychosocial treatments for cancer patients. This is followed by a summary of terminology and costing concepts in the economic evaluation of psychosocial treatments, and a review of the literature on medical cost offset in mental health, other medical populations, and in cancer patients. The literature clearly supports the notion that psychosocial interventions are not only effective, but also economical. Conclusions support adding costing data into evaluations of the efficacy of psychosocial treatments in order to detail the often present but usually overlooked long‐term cost savings that may be accrued to overburdened health‐care systems. Copyright © 2004 John Wiley & Sons, Ltd.
Einsatz von Schrauben‐Pumpen zur Förderung von Wasserstoff‐/Sauerstoff‐Gemischen. The use of skrewpumps to compress mixtures of Hydrogen and Oxygen
Authors: v.d. Waydbrink H. , Oswald D. , Gutte F. 
Published: December 2004

AbstractDer Artikel zeigt, wie Vakuumsysteme ausgeführt werden können, in denen zündfähige Gemische vorhanden sein können, eine Absicherung mit herkömmlichen Flammendurchschlagsicherungen jedoch nicht möglich ist. Dafür ist es jedoch notwendig, die Prozesszustände des Vakuumsystems genau zu analysieren und Betriebsbedingungen entsprechend zu definieren. Die Zoneneinteilung für den Ex‐Schutz gemäß ATEX wurde nicht behandelt.
La Mesure des Variations Climatiques Continentales Application à la Période Comprise entre 130.000 et 90.000 Ans B. P.
Authors: Duplessy J.C. , Labeyrie J. , Lalou C. , Nguyen H.V. 
Published: December 2004

Les mesures du rapport isotopique 18O/16O le long de l'axe de stalagmites soigneusement choisies donnent u̇n enregistrement climatique continental qui peut être comparé aux données de la paléoclimatologie océanique. Les âges des différentes couches de la stalagmite sont établis soit par la méthode du carbone 14 pour la période de 0 à 35.000 ans b.p., soit par le rapport 230Th/234U jusqu'à 300.000 ans b.p.La validité de cette méthode est discutée et une application en est donée pour la période allant de 130.000 à 90.000 ans b.p.Measurements of the isotopic ratio 18O/16O along the axis of carefully chosen stalagmites give a continental climatic record which can be compared to oceanic paleoclimatological data. Ages of stalagmite layers are established either by carbon 14 for the period 0 to 35,000 years b.p. or by 230Th/234U ratio until 300,000 years b.p.The validity of this method is discussed and an application is given for the period 130,000 to 90,000 years b.p.
A Contribution to Pleistocene Chronology in Southeast Essex, England
Authors: Gruhn Ruth , Bryan Alan Lyle , Moss A.J. 
Published: December 2004

Parallel to the Essex coast north of the mouth of the Thames, a series of gravel spreads ranging in altitude from near sea level westward to more than 200 ft O.D. (mean sea level) proved to be the remnants of an abandoned Thames/Medway terrace system, rather than a series of “raised” beaches, as their location had suggested. The seaward side of the ancient river valley has subsequently been “captured” by subsidence.Evidence is given for five terraces, with surface levels between 5 and 75 ft O.D. Because of subsidence of the Essex coast, the terrace levels are not easily correlatable with either the Thames or Medway terrace levels. Temporal placement is attempted on the basis of one site in the 25 ft Barling terrace, which yielded a Middle Acheulian archaeological assemblage associated with a cool temperate fauna including an early form of mammoth. An ice wedge cast in the Barling terrace was filled with floodloam which weathered to a parabraunerde soil during an interglacial climate warmer than now. For these reasons man is thought to have lived on the floodplain of the Barling terrace either at the onset of the Wolstonian (Riss) glacial or during an interstadial of that stage. The question of possible linkages between Swanscombe and Clacton terraces is discussed.