bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired Postprandial Blood Flow in Adipose Tissue May Be an Early Marker of Insulin Resistance in Type 2 Diabetes
Authors: Dimitriadis George , Lambadiari Vaia , Mitrou Panayota , Maratou Eirini , Boutati Eleni , Panagiotakos Demosthenes B. , Economopoulos Theofanis , Raptis Sotirios A. 
Published: November 2007

OBJECTIVE—We investigated the changes in subcutaneous adipose tissue blood flow (ATBF) after a meal in the various stages of type 2 diabetes.
RESEARCH DESIGN AND METHODS—Five groups were examined: healthy control subjects, first-degree relatives of subjects with type 2 diabetes, subjects with impaired glucose tolerance (IGT), subjects with type 2 diabetes and postprandial hyperglycemia but normal fasting plasma glucose levels (diabetes group A [DMA]), and subjects with type 2 diabetes with both postprandial and fasting hyperglycemia (diabetes group B [DMB]). ATBF was measured with 133Xe.
RESULTS—ATBF was higher in control subjects (1,507 ± 103 ml/100 cm3 tissue × min) versus relatives and IGT, DMA, and DMB subjects (845 ± 123, 679 ± 69, 765 ± 60, and 757 ± 69 ml/100 cm3 tissue × min, respectively; P &lt; 0.001). Insulin sensitivity index (ISI) in control subjects (82 ± 3 mg × l2/mmol × mU × min) was higher versus that for relatives and IGT, DMA, and DMB subjects (60 ± 3, 45 ± 1, 40 ± 6, and 29 ± 4 mg × l2/mmol × mU × min, respectively; P &lt; 0.0001). ISI was positively associated with peak-baseline ATBF (β coefficient 0.029 ± 0.013, P = 0.03).
CONCLUSIONS—After meal ingestion, insulin-stimulated ATBF was decreased in relatives and and IGT, DMA, and DMB subjects. This defect could be an early marker of insulin resistance that precedes the development of type 2 diabetes.
Intrahepatic Fat Accumulation and Alterations in Lipoprotein Composition in Obese Adolescents
Authors: Cali Anna M.G. , Zern Tosca L. , Taksali Sara E. , de Oliveira Ana Mayra , Dufour Sylvie , Otvos James D. , Caprio Sonia 
Published: November 2007

OBJECTIVE—Among other metabolic consequences, a dyslipidemic profile often accompanies childhood obesity. In adults, type 2 diabetes and hepatic steatosis have been shown to alter lipoprotein subclass distribution and size; however, these alterations have not yet been shown in children or adolescents. Therefore, our objective was to determine the effect of hepatic steatosis on lipoprotein concentration and size in obese adolescents.
RESEARCH DESIGN AND METHODS—Using fast magnetic resonance imaging, we measured intrahepatic fat content in 49 obese adolescents with normal glucose tolerance. The presence or absence of hepatic steatosis was determined by a threshold value for hepatic fat fraction (HFF) of 5.5%; therefore, the cohort was divided into two groups (HFF &gt; or &lt;5.5%). Fasting lipoprotein subclasses were determined using nuclear magnetic resonance spectroscopy.
RESULTS—Overall, the high-HFF group had 88% higher concentrations of large VLDL compared with the low-HFF group (P &lt; 0.001). Likewise, the high-HFF group had significantly higher concentrations of small dense LDL (P &lt; 0.007); however, the low-HFF group had significantly higher concentrations of large HDL (P &lt; 0.001). Stepwise multiple regression analysis revealed that high HFF was the strongest single correlate, accounting for 32.6% of the variance in large VLDL concentrations (P &lt; 0.002).
CONCLUSIONS—The presence of fatty liver was associated with a pronounced dyslipidemic profile characterized by large VLDL, small dense LDL, and decreased large HDL concentrations. This proatherogenic phenotype was strongly related to the intrahepatic lipid content.
Direct Enantioselective Synthesis of Bicyclic Diels–Alder Products
Authors: Sundén Henrik , Rios Ramon , Xu Yongmei , Eriksson Lars , Córdova Armando 
Published: November 2007

AbstractThe direct amine‐catalyzed enantioselective Diels–Alder reaction between α,β‐unsaturated cyclic ketones and nitroolefins is presented. A simple diamine catalyzes the asymmetric Diels–Alder reaction with high stereoselectivity and furnishes the corresponding Diels–Alder adducts in good to high yields with >25:1 dr and up to 86 % ee. The study demonstrates a convenient entry to functionalized bicyclic molecules contaning four stereocenters that are formed with excellent diastreoselectivity and good to high enantioselectivity.
Asymmetric Direct Aldol Reaction of α‐Keto Esters and Acetone Catalyzed by Bifunctional Organocatalysts
Authors: Wang Fei , Xiong Yan , Liu Xiaohua , Feng Xiaoming 
Published: November 2007

AbstractA type of C2‐symmetrical bisprolinamide has been developed for the asymmetric aldol reaction between acetone and α‐keto esters, which furnishes the chiral tertiary alcohols in high yields (up to 99 %) with high enantioselectivities (up to 94 % ee). Aliphatic, heteroaromatic and aromatic α‐keto esters including those with electron‐donating or electron‐withdrawing group substituents were found to be suitable substrates in the presence of bisprolinamide 2a (15 mol %) and AcOH (150 mol %) with reaction times of no more than 16 h. This process is easily manipulated with readily available reagents. The geometry of catalyst 2a was fully optimized at the B3LYP/6‐31G(d) level with all electron calculations. Based on the experimental investigations and DFT calculations of catalyst 2a, a possible transition state A has been proposed to explain the origin of the activation and asymmetric inductivity.
Comparative study of the hydrolytic degradation of glycolide/L‐lactide/ε‐caprolactone terpolymers initiated by zirconium(IV) acetylacetonate or stannous octoate
Authors: Kasperczyk Janusz , Hu Yanfei , Jaworskam Joanna , Dobrzynski Piotr , Wei Jia , Li Suming 
Published: November 2007

AbstractA series of copolymers have been synthesized by the ring‐opening polymerization of glycolide, L‐lactide, and ϵ‐caprolactone with zirconium(IV) acetylacetonate [Zr(Acac)4] or stannous octoate [Sn(Oct)2] as the catalyst. The resulting terpolymers have been characterized by analytical techniques such as proton nuclear magnetic resonance, size exclusion chromatography, and differential scanning calorimetry. Data have confirmed that Sn(Oct)2 leads to less transesterification of polymer chains than Zr(Acac)4 under similar conditions. The various copolymers have been compression‐molded and allowed to degrade in a pH 7.4 phosphate buffer at 37°C. The results show that the degradation rate depends not only on the copolymer composition but also on the chain microstructure, the Sn(Oct)2‐initiated copolymers degrading less rapidly than Zr(Acac)4‐initiated ones with more random chain structures. The caproyl component appears the most resistant to degradation as its content increases in almost all cases. Moreover, caproyl units exhibit a protecting effect on neighboring lactyl or glycolyl units. The glycolyl content exhibits different features: it decreases because of faster degradation of glycolyl units, which are more hydrophilic than caproyl and lactyl ones, remains stable in the case of abundant CGC sequences, which are very resistant to degradation, or even increases because of the formation of polyglycolide crystallites. Terpolymers can crystallize during degradation if the block length of one of the components is sufficiently long, even though they are amorphous initially. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ring opening polymerization of aliphatic cyclic carbonates in the presence of natural amino acids
Authors: Liu Jiyan , Zhang Chao , Liu Lijian 
Published: November 2007

AbstractPoly(dimethyl trimethylene carbonate) (PDTC) and poly(trimethylene carbonate) (PTMC) were synthesized by ring‐opening polymerization (ROP) of dimethly trimethylene carbonate (DTC) and trimethylene carbonate (TMC) in the presence of five kinds of natural amino acids (L‐alanine, L‐valine, L‐leucine, L‐proline, and L‐phenylalanine). PDTCs with number‐average molecular weight (Mn) from 6700 to 18,900 g/mol and PTMCs with Mn from 7200 to 17,800 g/mol were obtained at a feed ratio of [monomer]/[L‐phenylalanine] ranging from 50 to 200. The results of 1H nuclear magnetic resonance and titration proved amino acid connecting onto the polymer backbone. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Zeta potential of Nafion molecules in isopropanol‐water mixture solvent
Authors: Zhang Haining , Pan Jingjing , He Xiuchong , Pan Mu 
Published: November 2007

AbstractStructure of Nafion in isopropanol/water mixture solvent has been investigated using zeta potential. It was found that zeta potential of Nafion strongly depends on the concentration. When the concentration of Nafion varied from 0.5 to 1 wt %, zeta potential increased significantly from about 0 to −12 mV, corresponding to the change of structure of Nafion molecules from true solution to dispersion of aggregates. While the concentration is above 5 wt %, micelle‐like structure of Nafion aggregates was proposed. The dependence of zeta potential of Nafion on pH value at concentration of 5 wt % shows a nonmonotonic function and isoelectric point of Nafion‐Na of 8.0 was observed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Recombinant therapeutic proteins: Production platforms and challenges
Authors: Dingermann Theo 
Published: November 2007

AbstractSince the approval of insulin in 1982, more than 120 recombinant drug substances have been approved and become available as extremely valuable therapeutic options. Exact copying of the most common human form is no longer a value per se, as challenges, primarily related to the pharmacokinetics of artificial recombinant drugs, can be overcome by diverging from the original. However, relatively minor changes in manufacturing or packaging may impact safety of therapeutic proteins. A major achievement is the development of recombinant proteins capable of entering a cell. Such drugs open up completely new opportunities by targeting intracellular mechanisms or by substituting intracellularly operating enzymes. Concerns that protein variants would cause an intolerable immune response turned out to be exaggerated. Although most recombinant drugs provoke some immune response, they are still well tolerated. This knowledge might result in a change in attitude towards antibody formation, i.e., neutralizing antibody activity (in vitro) may be overcome by dosing consistently on the basis of antibody titers and not only on body weight. As with other drugs, efficacy and safety of therapeutic proteins have to be demonstrated in clinical studies, and superiority over available products has to be proven instead of just claimed.
Semaphorins 3A, 3C, and 3F in mesencephalic dopaminergic axon pathfinding
Authors: Hernández‐Montiel Hebert L. , Tamariz Elisa , Sandoval‐Minero M. Teresa , Varela‐Echavarría Alfredo 
Published: November 2007

AbstractBy analyzing the mechanisms that govern dopaminergic axon pathfinding from the midbrain to the striatum in embryonic rat brains, we identified neuroepithelial regions that exert chemotropic effects on mesencephalic dopaminergic axons. Explants from the pretectum and the striatum showed an attractive effect, whereas those from the midhindbrain boundary, the dorsal thalamus, and the ventral thalamus had no effect. Expression of semaphorin (Sema) 3C and Sema3F in the pretectum and of Sema3A in the striatum suggested a role for these axon guidance molecules in dopaminergic axon pathfinding. When expressed in HEK293 cell aggregates, Sema3C had an attractive effect and enhanced axon growth, Sema3A enhanced axon growth, and Sema3F had a repulsive effect on dopaminergic axons. Antineuropilin‐1 and antineuropilin‐2 antibodies reduced attraction by the pretectum, whereas attraction by the striatum was not affected by the presence of antineuropilin‐1 antibodies. Moreover, neuropilin‐1‐ and neuropilin‐2‐soluble Fc chimeras reduced the attraction by the pretectum. These results suggest that semaphorins may help to establish the dopaminergic projection from the midbrain to the striatum during embryonic development. J. Comp. Neurol. 506:387–397, 2008. © 2007 Wiley‐Liss, Inc.
Emergence of cellular markers and functional ionotropic glutamate receptors on tangentially dispersed cells in the developing mouse retina
Authors: Acosta Monica L. , Bumsted O'Brien Keely M. , Tan Seong‐Seng , Kalloniatis Michael 
Published: November 2007

AbstractTangential cell dispersion in the retina is a spacing mechanism that establishes a regular mosaic organization among cell types and contributes to their final positioning. The present study has used the X‐inactivation transgenic mouse expressing the lacZ reporter gene on one X chromosome. Due to X chromosome inactivation, 50% of early progenitor cells express β‐galactosidase (β‐Gal); therefore, all cells derived from a particular β‐Gal‐expressing progenitor cell can be identified in labeled columns. The radial segregation of clonally related β‐Gal‐positive and β‐Gal‐negative cells can be used to determine whether single cells transgress a clonal boundary in the retina. We investigated the extent to which particular cell classes tangentially disperse by analyzing the placement of labeled cells expressing particular markers at several ages and quantifying their tangential displacement. Retinal neurons expressing cell markers at postnatal day (P) 1 have a greater degree of tangential dispersion compared with amacrine and bipolar cells at P5–6. We also studied whether there is a functional correlation with these dispersion patterns by investigating the emergence of functional ionotropic glutamate receptors. To determine the degree of functional glutamate receptor activation, agmatine (AGB) was used in combination with cell‐specific labeling. AGB permeates functional glutamate receptor channels following activation with α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA), kainate or N‐methyl‐D‐aspartate (NMDA). Within these receptor groups, high concentrations of AMPA, kainate, and NMDA are associated with a high degree of tangential dispersion in the adult. Developmentally, functional kainate and AMPA receptors were detected by P1 and were associated with tangentially dispersed cells. Functional NMDA receptors were not detected as early as kainate and AMPA receptors. These results indicate that cells generated early during development are more likely to disperse tangentially compared with those generated later in development. Therefore, functional AMPA and kainate receptors may play a critical role in tangentially displacing cell types. J. Comp. Neurol. 506:506–523, 2008. © 2007 Wiley‐Liss, Inc.
Developmental expression of glutamic acid decarboxylase and of γ‐aminobutyric acid type B receptors in the ascidian Ciona intestinalis
Authors: Zega Giuliana , Biggiogero Maira , Groppelli Silvia , Candiani Simona , Oliveri Diana , Parodi Manuela , Pestarino Mario , De Bernardi Fiorenza , Pennati Roberta 
Published: November 2007

AbstractWe describe Ciona intestinalis γ‐aminobutyric acid (GABA)‐ergic neurons during development, studying the expression pattern of Ci‐GAD (glutamic acid decarboxylase: GABA synthesizing enzyme) by in situ hybridization. Moreover, we cloned two GABAB receptor subunits (Ci‐GABABRs), and a phylogenetic analysis (neighbor‐joining method) suggested that they clustered with their vertebrate counterparts. We compared Ci‐GAD and Ci‐GABABRs expression patterns in C. intestinalis embryos and larvae. At the tailbud stage, Ci‐GAD expression was widely detected in central and peripheral nervous system (CNS/PNS) precursors, whereas Ci‐GABABRs expression was evident at the level of the precursors of the visceral ganglion. GABA was localized by immunohistochemistry at the same developmental stage. In the larva, Ci‐GAD transcripts and GABA immunofluorescence were also detected throughout the CNS and in some neurons of the PNS, whereas transcripts of both GABAB receptor subunits were found mainly in the CNS. The expression pattern of Ci‐GABABRs appeared restricted to Ci‐GAD‐positive territories in the sensory vesicle, whereas, in the visceral ganglion, Ci‐GABABRs transcripts were found in ventral motoneurons that did not express Ci‐GAD. Insofar as GABAergic neurons are widely distributed also in the CNS and PNS of vertebrates and other invertebrate chordates, it seems likely that GABA signaling was extensively present in the protochordate nervous system. Results from this work show that GABA is the most widespread inhibitory neurotransmitter in C. intestinalis nervous system and that it can signal through GABAB receptors both pre‐ and postsynaptically to modulate different sensory inputs and subsequent swimming activity. J. Comp. Neurol. 506:489–505, 2008. © 2007 Wiley‐Liss, Inc.
Aminopyrimidine‐Based Donor–Acceptor Chromophores: Push–Pull versus Aromatic Behaviour
Authors: Ortíz Alejandro , Insuasty Braulio , Torres M. Rosario , Herranz M. Ángeles , Martín Nazario , Viruela Rafael , Ortí Enrique 
Published: November 2007

AbstractNovel 2‐aminopyrimidines substituted with two electron‐donor dialkylamino groups and either one dicyanovinyl (4a–d) or one tricyanovinyl (7a–d) electron‐acceptor group have been synthesized, and the balance between their push–pull character and their aromatic behaviour has been studied by experimental (spectroscopic, electrochemical and X‐ray analysis) and theoretical (DFT/B3LYP/6‐31G**) methods. Calculations reveal that the push–pull character is energetically favoured with respect to the preservation of the aromaticity of the pyrimidine ring. X‐ray analysis of 7a confirms the theoretical predictions and reveals a strong distortion from planarity due to the steric interaction between the tricyanovinyl group and the adjacent dialkylamino moieties. In contrast with what would normally be expected for push–pull compounds, the visible‐region absorption bands of 4a–d and 7a–d are associated with π–π* electronic transitions and not with intramolecular charge‐transfer absorptions. In each compound, both the HOMO and the LUMO are spread over the whole molecule and are not located on the donor and acceptor moieties, respectively, as is the case for typical push–pull chromophores.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
4‐Cyano‐6,7‐dimethoxycarbostyrils with Solvent‐ and pH‐Independent High Fluorescence Quantum Yields and Emission Maxima
Authors: Ahvale Appasaheb B. , Prokopcová Hana , Šefčovičová Jana , Steinschifter Waltraud , Täubl Anna E. , Uray Georg , Stadlbauer Wolfgang 
Published: November 2007

AbstractHighly fluorescent and stable 6,7‐dimethoxy‐2‐oxoquinoline‐4‐carbonitriles (11) were synthesized starting from appropriate 4‐hydroxyquinolones 3 via reactive 4‐chloroquinolones 8 by using toluenesulfinates as catalysts. In contrast to the well‐described 4‐trifluoromethyl‐substituted analogues 18, N‐substituted derivatives 11 fluoresce in water, polar, and apolar solvents in a narrow 430–440‐nm window with almost constant quantum yield of 0.5. Equal excitation is possible in the broad double maximum between 385 and 410 nm yielding identical data between pH 1 and 11. These properties could lead to a broadly usable fluorescence standard. N‐Alkylation with bromoacetate yields ester 13 in good yields. Reactive succinimidoyl (OSu) ester 15 was prepared by saponification to acid 14. With amino acids or peptides, linking to labeled derivatives 17 was achieved under mild conditions in slightly basic aqueous media. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Stimulus‐contrast‐induced biases in activation order reveal interaction between V1/V2 and human MT+
Authors: Maruyama Masaki , Palomo Daniel D. , Ioannides Andreas A. 
Published: November 2007

AbstractThe luminance contrast of a visual stimulus is known to modulate the response properties of areas V1 and the human MT complex (hMT+), but has not been shown to modulate interactions between these two areas. We examined the direction of information transfer between V1/V2 and hMT+ at different stimulus contrasts by measuring magnetoencephalographic (MEG) responses to moving and stationary stimuli presented centrally or peripherally. To determine the direction of information flow, the different response latencies among stimuli and hemispheres in V1/V2 was compared with those of hMT+. At high contrast, responses to stimulus motion and position began in V1/V2, and were followed in hMT+ with a delay between 34 and 55 ms. However, at low contrast, lateralized responses in hMT+ came first, with those in V1/V2 lagging with a delay of 27 ms. Also, at high contrast, stationary stimuli produced greater responses than motion stimuli in V1/V2, while the reverse was true in hMT+, whose response lagged behind the initial response in V1/V2. The same activation order was found using Mutual Information Analysis of the response variances for each condition. Here, the response variances in hMT+ mimicked and trailed those of V1/V2 at high contrast, whereas the reverse was true at low contrast. Such consistent interactions found using two different methodologies strongly supports a processing link between these two areas. The results also suggest that feedback from hMT+ for low‐contrast stimuli compensates for unresolved processing in V1/V2 when the input of a visual image is weak. Hum Brain Mapp, 2009. © 2007 Wiley‐Liss, Inc.
Understanding second careers: Lessons from a study of U.S. navy admirals
Authors: Baruch Yehuda , Quick James Campbell 
Published: November 2007

AbstractWe examined the career transition of senior executives from a strong bureaucratic organization into a dynamic business environment. In surveying retired, flag‐rank admirals characterized by the need to start a second career, we found significant support for a career transition model. The retired admirals in this study largely enjoyed a smooth transition into civilian careers. Their traditional career was associated primarily with external success, the contemporary protean career with internal success. The role of the organization proved instrumental for a successful transition. © 2007 Wiley Periodicals, Inc.
Career success after stigmatizing organizational events
Authors: Hamori Monika 
Published: November 2007

AbstractThis article examines the effect of six types of stigmatizing organizational events on employees' career moves to another employer: criticism of the organization in the media; resignation of key individuals from the organization; downsizing; a drop in net income; lawsuits launched by the Securities and Exchange Commission, competitors, or customers; and lawsuits launched by employees. Stigmatizing events that signal the decline of corporate performance are the most devastating for professional career success. Outsiders, on the other hand, are less sensitive to an organization's involvement in lawsuits launched by public authorities or employees. Stigmatizing events affect the career success of every professional in the organization, irrespective of his or her hierarchical level. © 2007 Wiley Periodicals, Inc.
How groups learn, continuously
Authors: London Manuel , Sessa Valerie I. 
Published: November 2007

AbstractThis article examines how groups learn, conditions that affect learning, and interventions to improve the learning process. Adaptive group learning is reacting almost automatically to stimuli to make minor changes in process and outcome. Generative group learning is proactive learning for mastery. Transformative group learning is reconstructing meaning and fundamentally changing the way the group operates. Pressures and opportunities in the environment and group readiness stimulate and support these different types of learning. Group leaders, members, and human resource professionals who facilitate, coach, and provide resources for development can apply this knowledge to diagnose group conditions and encourage continuous learning. © 2007 Wiley Periodicals, Inc.