bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetric Organocatalytic Cyclopropanation – Highly Stereocontrolled Synthesis of Chiral Cyclopropanes with Quaternary Stereocenters
Authors: Companyó Xavier , Alba Andrea‐Nekane , Cárdenas Francisco , Moyano Albert , Rios Ramon 
Published: May 2009

AbstractA convenient and novel domino reaction for the synthesis of highly functionalized cyclopropanes is reported. The addition of 2‐bromoketo esters to a variety of α,β‐unsaturated aldehydes catalyzed by secondary amines leads to chiral cyclopropanes with three stereogenic carbon atoms, including one quaternary stereocenter, in a highly stereocontrolled fashion.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Reductive‐Cyclization‐Mediated Synthesis of Fused Polycyclic Quinolines from Baylis–Hillman Adducts of Acrylonitrile: Scope and Limitations
Authors: Singh Virender , Hutait Samiran , Batra Sanjay 
Published: May 2009

AbstractThe synthesis of a variety of polycyclic quinolines is described. The target molecules were obtained in two steps by an initial reductive cyclization followed by another intramolecular cyclization in the allylamines afforded from either the acetates or allyl bromides of Baylis–Hillman adducts of 2‐nitrobenzaldehydes and acrylonitrile. The two steps proceeded in one‐pot for those substrates in which a formyl or hydroxy group reacted with the amino group of the 2‐aminoquinoline in the second intramolecular cyclization. In contrast, a basic medium was necessary for the second intramolecular cyclization reaction in substrates in which an alkoxycarbonyl group and the amino group participated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Reinvestigation of Supramolecular Complexes with Cyclophanes of the Stetter and Koga Type: Agreement and Disagreement with Solid‐State Structures
Authors: Wald Peter , Schneider Hans‐Jörg 
Published: May 2009

AbstractIn this paper we reinvestigate the historically oldest complexations with cyclophanes of the Stetter and Koga type (1 and 2), and new macrocycle 3, which is a hybrid of the two former. NMR titrations in aqueous solution reveal that benzene forms, as known, strong complexes with Koga‐type host 2, but also weaker ones with Stetter cyclophane 1, in contrast to earlier observations with the corresponding crystals. Tosylate forms weak complexes with 1, but stronger ones with 2 and 3. The binding free energy difference (ΔG = 7 kJ mol–1) between tosylate and benzene as guest and 2 or 3 as host agrees well with the salt bridge increment found earlier with many supramolecular complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of a β‐Ketophosphonate Bioisostere of UDP‐N‐acetylglucosamine
Authors: Auberger Nicolas , Gravier‐Pelletier Christine , Le Merrer Yves 
Published: May 2009

AbstractA concise route to a new β‐ketophosphonate analog of glycosyl nucleotides is described. Such a diphosphate bioisostere is a stable mimic of enzyme substrates involved in peptidoglycan biosynthesis and will be the starting point for the development of new potential antibiotics. The synthesis is carried out by condensing a lithiomethylenephosphonate derivative on a methyl N‐acetylglucosaminylacetate followed by esterification with a uridine derivative. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Minority report: Social identity, cognitions of rejection and intergroup anxiety predicting prejudice from one racially marginalized group towards another
Authors: Barlow Fiona Kate , Louis Winnifred R. , Terry Deborah J. 
Published: May 2009

AbstractThe present study investigated the attitudes of one disadvantaged minority group in Australia, Asian Australians (N = 87), towards another more severely disadvantaged minority group, Aboriginal Australians. Asian Australian attitudes were compared to European Australian attitudes (N = 273). Cognitions of outgroup rejection, identification and intergroup anxiety were assessed in relation modern racism, desire for intergroup avoidance and support for a national apology. Both Asian and European participants who perceived Aboriginal Australians as rejecting were more likely to express intergroup anxiety. Anxiety mediated the relationship between cognitions of rejection and the dependent variables. Whilst there was a direct positive relationship between European Australian identification and prejudice, for Asian Australian participants, identification moderated the relationship between cognitions of rejection and the dependent variables. Highly identified Asian Australian participants were particularly sensitive to cognitions of rejection, which increased modern racism and avoidance and lowered political support. The pattern was reversed for low identifiers, who were more likely to endorse a national apology to Aboriginal Australians when they perceived Aboriginal Australians as rejecting. The role of perceived rejection in predicting prejudice and avoidance, and the moderating role of Asian Australian identification, are both discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Magnetic forces and moving body induced voltages: applications to velocity sensing and DC–AC conversion
Authors: Faria J. A. Brandão 
Published: May 2009

AbstractThis research and tutorial paper illustrates two interlinked phenomena of the greatest importance for power and energy systems engineers, i.e., magnetic forces and moving body induced voltages. A two‐solenoid system with driving and sensing parts is analyzed taking into account that a moving ferromagnetic core can freely move along the system axial coordinate. At first‐order approximation the frequency of the oscillating core movement is shown to be linearly controllable by the direct‐current intensity injected in the driving solenoid. On the other hand the induced voltage on the sensing solenoid is shown to be a sinusoidal voltage with a frequency twice the one of the moving core. Copyright © 2009 John Wiley & Sons, Ltd.
Evolutionary trace of human odorant receptors of chromosome 17
Authors: Knape Kirsten , Beyer Anton , Stary Anna , Buchbauer Gerhard , Wolschann Peter 
Published: May 2009

AbstractStudies on the odorant receptor cluster located on human chromosome 17, which contains 18 odorant receptor genes, are presented. After an extended search for orthologues of those odorant receptor genes in chimpanzee, rat and mouse genomes, comparisons subject to genomic location, similarities and function were made. Different ways of evolutionary propagation can be observed. This leads to conversion into pseudogenes, but also duplication of some genes occurs. Copyright © 2009 John Wiley & Sons, Ltd.
A novel method for haplotype clustering and visualization
Authors: Teo Yik Y. , Small Kerrin S. 
Published: May 2009

AbstractIn population genetics, it is common to represent the haplotype diversity at a genomic region between multiple populations using well‐constructed visual representations. This typically requires the chromosomes from these populations to be grouped according to some definition of haplotypic similarity. Here, we introduce a novel algorithm for clustering haplotypes with the specific aim of addressing haplotype diversity within or between populations. The algorithm allows for missing data in the haplotypes and appropriately downweighs single nucleotide polymorphisms with higher extent of missingness. By identifying the canonical haplotypes in a genomic region, defined as the haplotype forms, which most chromosomes are similar to, the algorithm maps each chromosome to either a unique canonical haplotype or as a mosaic of the identified canonical haplotypes. This mapping can subsequently be utilized for producing graphical visualizations of the haplotype clustering for understanding the extent of haplotype diversity in the region. The clustering application has been implemented in R for distribution as haplosim, and we also provide a visualization script hapvisual for graphical display of the clustering results. The outcome of such analysis can be informative in understanding the extent of haplotype diversity between populations, in addressing the reproducibility of established association signals across multiple populations, and also in the investigation of positive selection in the human genome. Genet. Epidemiol. 34:34–41, 2010. © 2009 Wiley‐Liss, Inc.
Facial expressions of pain modulate observer's long‐latency responses in superior temporal sulcus
Authors: Kujala Miiamaaria V. , Tanskanen Topi , Parkkonen Lauri , Hari Riitta 
Published: May 2009

AbstractThe strength of brain responses to others' pain has been shown to depend on the intensity of the observed pain. To investigate the temporal profile of such modulation, we recorded neuromagnetic brain responses of healthy subjects to facial expressions of pain. The subjects observed grayscale photos of the faces of genuine chronic pain patients when the patients were suffering from their ordinary pain (Chronic) and when the patients' pain was transiently intensified (Provoked). The cortical activation sequence during observation of the facial expressions of pain advanced from occipital to temporo‐occipital areas, and it differed between Provoked and Chronic pain expressions in the right middle superior temporal sulcus (STS) at 300–500 ms: the responses were about a third stronger for Provoked than Chronic pain faces. Furthermore, the responses to Provoked pain faces were about 40% stronger in the right than the left STS, and they decreased from the first to the second measurement session by one‐fourth, whereas no similar decrease in responses was found for Chronic pain faces. Thus, the STS responses to the pain expressions were modulated by the intensity of the observed pain and by stimulus repetition; the location and latency of the responses suggest close similarities between processing of pain and other affective facial expressions. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Functional integration within the human pain system as revealed by Granger causality
Authors: Ploner Markus , Schoffelen Jan‐Mathijs , Schnitzler Alfons , Gross Joachim 
Published: May 2009

AbstractPain is a complex experience subserved by an extended network of brain areas. However, the functional integration among these brain areas, i.e., how they interact and communicate to generate a coherent pain percept and an adequate behavioral response is largely unknown. Here, we used magnetoencephalography to investigate functional integration among pain‐related cortical activations in terms of Granger causality and compared it with tactile‐related activations. The results show causal influences of primary somatosensory cortex on secondary somatosensory cortex for tactile‐related but not for pain‐related activations, which supports the proposition of a partially parallel organization of pain processing in the human brain. Furthermore, during a simple reaction time task, the strength of causal influences between somatosensory areas but not the latencies between activations correlated significantly with the speed of reaction times. These findings show how the analysis of functional integration complements traditional analyses of electrophysiological data and provides novel and behaviorally relevant information about the organization of the human pain system. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Dysfunctional very-low-density lipoprotein synthesis and release is a key factor in nonalcoholic steatohepatitis pathogenesis # †
Authors: Fujita Koji , Nozaki Yuichi , Wada Koichiro , Yoneda Masato , Fujimoto Yoko , Fujitake Mihoyo , Endo Hiroki , Takahashi Hirokazu , Inamori Masahiko , Kobayashi Noritoshi , Kirikoshi Hiroyuki , Kubota Kensuke , Saito Satoru , Nakajima Atsushi 
Published: May 2009

Abstract
The specific mechanisms of nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) pathogenesis remain unknown. In the present study we investigated the differences between NAFL and NASH in terms of liver lipid metabolites and serum lipoprotein. In all, 104 Japanese subjects (50 men and 54 postmenopausal women) with histologically verified NAFL disease (NAFLD) (51 with NAFL, 53 with NASH) were evaluated; all diagnoses were based on liver biopsy findings and the proposed diagnostic criteria. To investigate the differences between NAFL and NASH in humans, we carefully examined (1) lipid inflow in the liver, (2) lipid outflow from the liver, (3) very-low-density lipoprotein (VLDL) synthesis in the liver, (4) triglyceride (TG) metabolites in the liver, and (5) lipid changes and oxidative DNA damage. Most of the hepatic lipid metabolite profiles were similar in the NAFL and NASH groups. However, VLDL synthesis and lipid outflow from the liver were impaired, and surplus TGs might have been produced as a result of lipid oxidation and oxidative DNA damage in the NASH group. Conclusion: A growing body of literature suggests that a deterioration in fatty acid oxidation and VLDL secretion from the liver, caused by the impediment of VLDL synthesis, might induce serious lipid oxidation and DNA oxidative damage, impacting the degree of liver injury and thereby contributing to the progression of NASH. Therefore, dysfunctional VLDL synthesis and release may be a key factor in progression to NASH. (Hepatology 2009.)
Expression of Organic Cation Transporters OCT1 (SLC22A1) and OCT3 (SLC22A3) Is Affected by Genetic Factors and Cholestasis in Human Liver†
Authors: Nies Anne T. , Koepsell Hermann , Winter Stefan , Burk Oliver , Klein Kathrin , Kerb Reinhold , Zanger Ulrich M. , Keppler Dietrich , Schwab Matthias , Schaeffeler Elke 
Published: May 2009

An important function of hepatocytes is the biotransformation and elimination of various drugs, many of which are organic cations and are taken up by organic cation transporters (OCTs) of the solute carrier family 22 (SLC22). Because interindividual variability of OCT expression may affect response to cationic drugs such as metformin, we systematically investigated genetic and nongenetic factors of OCT1/SLC22A1 and OCT3/SLC22A3 expression in human liver. OCT1 and OCT3 expression (messenger RNA [mRNA], protein) was analyzed in liver tissue samples from 150 Caucasian subjects. Hepatic OCTs were localized by way of immunofluorescence microscopy. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and genome-wide single-nucleotide polymorphism microarray technology served to genotype 92 variants in theSLC22A1-A3/OCT1-3gene cluster. Transport of metformin by recombinant human OCT1 and OCT3 was compared using transfected cells. OCT1 mRNA and protein expression varied 113- and 83-fold, respectively; OCT3 mRNA expression varied 27-fold. OCT1 transcript levels were on average 15-fold higher compared with OCT3. We localized the OCT3 protein to the basolateral hepatocyte membrane and identified metformin as an OCT3 substrate. OCT1 and OCT3 expression are independent of age and sex but were significantly reduced in liver donors diagnosed as cholestatic (P≤ 0.01). Several haplotypes for OCT1 and OCT3 were identified. Multivariate analysis adjusted for multiple testing showed that only the OCT1-Arg61Cys variant (rs12208357) strongly correlated with decreased OCT1 protein expression (P< 0.0001), and four variants inOCT3(rs2292334, rs2048327, rs1810126, rs3088442) were associated with reduced OCT3 mRNA levels (P= 0.03).Conclusion:We identified cholestasis and genetic variants as critical determinants for considerable interindividual variability of hepatic OCT1 and OCT3 expression. This indicates consequences for hepatic elimination of and response to OCT substrates such as metformin. (Hepatology 2009.)
Angiotensin-converting-enzyme 2 inhibits liver fibrosis in mice #
Authors: Österreicher Christoph H. , Taura Kojiro , De Minicis Samuele , Seki Ekihiro , Penz-Österreicher Melitta , Kodama Yuzo , Kluwe Johannes , Schuster Manfred , Oudit Gavin Y. , Penninger Josef M. , Brenner David A. 
Published: May 2009

Abstract
The renin-angiotensin system (RAS) plays a major role in liver fibrosis. Recently, a homolog of angiotensin-converting-enzyme 1 (ACE1), termed ACE2, has been identified that appears to be a negative regulator of the RAS by degrading Ang II to Ang1-7. The aim of this study was to characterize the long-term effects of gene deletion of ACE2 in the liver, to define the role of ACE2 in acute and chronic liver disease, and to characterize the role of Ang1-7 in hepatic stellate cell (HSC) activation. Ace2 knockout (KO) mice and wild-type (wt) littermates underwent different models of acute and chronic liver injury. Liver pathology was analyzed by histology, immunohistochemistry, alpha smooth muscle actin (α-SMA) immunoblotting, and quantitative polymerase chain reaction (qPCR). Murine HSCs were isolated by collagenase-pronase-perfusion, and density gradient centrifugation. One-year-old ace2 KO mice spontaneously developed an inflammatory cell infiltration and mild hepatic fibrosis that was prevented by treatment with irbesartan. Ace2 KO mice showed increased liver fibrosis following bile duct ligation for 21 days or chronic carbon tetrachloride (CCl4) treatment. In contrast, ace2 KO mice subjected to acute liver injury models did not differ from wt littermates. Treatment with recombinant ACE2 attenuated experimental fibrosis in the course of cholestatic and toxic liver injury. HSCs express the Ang1-7 receptor Mas and Ang1-7 inhibited Ang II-induced phosphorylation of extracellular signal-regulated kinase (ERK)-1/2 in cultured HSCs. Conclusion: ACE2 is a key negative regulator of the RAS and functions to limit fibrosis through the degradation of Ang II and the formation of Ang1-7. Whereas loss of ACE2 activity worsens liver fibrosis in chronic liver injury models, administration of recombinant ACE2 shows therapeutic potential. (Hepatology 2009.)
Fornix transection selectively impairs fast learning of conditional visuospatial discriminations
Authors: Kwok Sze Chai , Buckley Mark J. 
Published: May 2009

AbstractAs the fornix has previously been implicated in the rapid learning of associations, we hypothesized that fornix transection in macaques would selectively impair the acquisition of rapidly learned conditional visuospatial discrimination problems. Macaque monkeys learned, postoperatively, three sets of concurrent problems of increasing sizes containing 8, 32, and 64 problems, respectively. Each problem consisted of four identical visual stimuli and animals had to learn which stimulus position was rewarded. The lesioned animals made significantly more errors‐to‐criterion on the smallest set of problems, consistent with the idea that the most rapidly acquired sets would be more vulnerable to fornical damage. Moreover, during the early stages of acquisition across all three sets, fornix transection selectively impeded monkeys' abilities to eliminate nonperseverative errors in correction trials, consistent with an inability to monitor or correct erroneous spatial responses made further back in time than the last trial. Both one‐trial learning and an errorless learning (facilitation of performance) were observed in control and fornix lesioned animals but neither were fornix‐dependent and overcoming the deleterious effect upon subsequent learning of having made prior errors was also unaffected by fornix transection. The data indicate that the fornix is not important for all forms of new learning; rather it is selectively concerned with the relatively rapid acquisition of spatial and temporal relationships between stimuli and responses. © 2009 Wiley‐Liss, Inc.This article was published online on 27 May 2009. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 11 June 2009.
Light deprivation improves melatonin related suppression of hippocampal plasticity
Authors: Talaei Sayyed Alireza , Sheibani Vahid , Salami Mahmoud 
Published: May 2009

AbstractIn early postnatal life, sensory inputs deeply influence development as well as function of the brain. Plasticity of synaptic transmission including its experimentally induced form, long‐term potentiation (LTP), is affected by sensory deprivation in neocortex. This study is devoted to assess if dark rearing and a dark phase synthesized hormone melatonin influence LTP in the hippocampus, an area of brain involved in learning and memory. In vivo experiments were carried out on two groups of 45‐days‐old male Wistar rats kept in standard 12‐h light/dark condition [light reared (LR) tested during the light phase] or in complete darkness [dark reared (DR)] since birth to testing. Each group, in turn, was divided to two, vehicle‐ and melatonin‐treated, groups. Stimulating the Schaffer collaterals of CA3 area of hippocampus extracellular postsynaptic potentials (EPSPs) were recorded in the CA1 area. Having the stable baseline responses to the test pulses, the hippocampus was perfused by either vehicle or 2 μg melatonin and EPSPs were recorded for 30 min. Then, for induction of LTP, the tetanus was applied to the Schaffer collaterals and the field potentials were pooled for 120‐min post‐tetanus. The light deprivation resulted in a significant augmentation in the amplitude of baseline responses. Also, we observed a melatonin‐induced increase in amplitude of the baseline recordings in either LR or DR animals. Tetanic stimulation elicited LTP of EPSPs in both LR and DR groups, robustly in the former where it lasted for about 90 min. Generally, melatonin inhibited the production of LTP in the two groups especially in the LR animals leading to a noticeable depression. We concluded that higher level of neuronal activity in the DR rats gives rise to a lower level of LTP. Weaker effect of melatonin on blocking the potentiation of post‐tetanus EPSPs in the DR rats may be the result of a desensitization of melatonin receptors due to chronically increased levels of this hormone in the visually deprived rats. © 2009 Wiley‐Liss, Inc.
Secocycloartane Triterpenoidal Saponins from the Leaves of Astragalus membranaceusBunge
Authors: Kuang Haixue , Okada Yoshihito , Yang Bingyou , Tian Zhenkun , Okuyama Tohru 
Published: May 2009

Abstractmagnified imageTwo new 9,10‐secocycloartane triterpenoidal saponins, named huangqiyenins E (1) and F (2) were isolated from the leaves of Astragalus membranaceus Bunge. Enzymatic hydrolysis of 1 and 2 afforded the aglycones huangqiyegenins III (3) and IV (4), resp. Further alkaline hydrolysis of 3 provided trideacetylhuangqiyegenin III (5). Their structures were established by detailed spectroscopic analysis as (3S,5R,6S,10R,12β,16β,24E)‐26‐(β‐D‐glucopyranosyloxy)‐10,16‐dihydroxy‐4,4,14‐trimethyl‐9,19‐cyclo‐9,10‐secocholesta‐9(11),24‐diene‐3,6,12‐triyl triacetate (1), (3S,5R,6S,10R, 16β,24E)‐26‐(β‐D‐glucopyranosyloxy)‐10,16‐dihydroxy‐4,4,14‐trimethyl‐9,19‐cyclo‐9,10‐secocholesta‐9(11), 24‐diene‐3,6‐diyl diacetate (2), (3S,5R,6S,10R,12β,16β,24E)‐10,16,26‐trihydroxy‐4,4,14‐trimethyl‐9,19‐cyclo‐9,10‐secocholesta‐9(11),24‐diene‐3,6,12‐triyl triacetate (3), (3S,5R,6S,10R,16β,24E)‐10,16,26‐trihydroxy‐4,4,14‐trimethyl‐9,19‐cyclo‐9,10‐secocholesta‐9(11),24‐diene‐3,6‐diyl diacetate (4), and (3S,5R, 6S,10R,12β,16β,24E)‐4,4,14‐trimethyl‐9,19‐cyclo‐9,10‐secocholesta‐9(11),24‐diene‐3,6,10,12,16,26‐hexol (5), resp.
Synthesis of Substituted 1,8‐Naphthyridine‐3‐carboxylates from Baylis–Hillman Adducts of Substituted 2‐Chloronicotinaldehydes
Authors: Narender Puli , Ravinder Mettu , Sadhu Partha Sarathi , China Raju Bhimapaka , Ramesh Chilukuri , Jayathirtha Rao Vaidya 
Published: May 2009

Abstractmagnified imageA series of substituted 1,8‐naphthyridine‐3‐carboxylates were synthesized for the first time from the Baylis–Hillman adducts obtained from 2‐chloronicotinaldehyde derivatives. Three methods were adopted to synthesize 1,8‐naphthyridine‐3‐carboxylates, of which the azide‐reduction route (Scheme 5) gave the best yields compared to the other attempted methods (Schemes 2 and 3).