bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Schistosoma mansoni egg‐induced inflammation by IL‐4‐responsive CD4+CD25−CD103+Foxp3− cells is IL‐10‐dependent
Authors: Dewals Benjamin , Hoving Jennifer C. , Horsnell William G. C. , Brombacher Frank 
Published: August 2010

AbstractHost protection to helminth infection requires IL‐4 receptor α chain (IL‐4Rα) signalling and the establishment of finely regulated Th2 responses. In the current study, the role of IL‐4Rα‐responsive T cells in Schistosoma mansoni egg‐induced inflammation was investigated. Egg‐induced inflammation in IL‐4Rα‐responsive BALB/c mice was accompanied with Th2‐biased responses, whereas T‐cell‐specific IL‐4Rα‐deficient BALB/c mice (iLckcreIl4ra−/lox) developed Th1‐biased responses with heightened inflammation. The proportion of Foxp3+ Treg in the draining LN of control mice did not correlate with the control of inflammation and was reduced in comparison to T‐cell‐specific IL‐4Rα‐deficient mice. This was due to IL‐4‐mediated inhibition of CD4+Foxp3+ Treg conversion, demonstrated in adoptively transferred Rag2−/− mice. Interestingly, reduced footpad swelling in Il4ra−/lox mice was associated with the induction of IL‐4 and IL‐10‐secreting CD4+CD25−CD103+Foxp3− cells, confirmed in S. mansoni infection studies. Transfer of IL‐4Rα‐responsive CD4+CD25−CD103+ cells, but not CD4+CD25high or CD4+CD25−CD103− cells, controlled inflammation in iLckcreIl4ra−/lox mice. The control of inflammation depended on IL‐10, as transferred CD4+CD25−CD103+ cells from IL‐10‐deficient mice were not able to effectively downregulate inflammation. Together, these results demonstrate that IL‐4 signalling in T cells inhibits Foxp3+ Treg in vivo and promotes CD4+CD25−CD103+Foxp3− cells that control S. mansoni egg‐induced inflammation via IL‐10.
Routes to Ruthenium–Fluoro Cations of the Type [RuL2(CO)nF]+ (n = 2,3; L = PR3, NHC): A Play‐Off between Solvent, L and Weakly Coordinating Anion
Authors: Coleman Karl S. , Fawcett John , Harding Duncan A. J. , Hope Eric G. , Singh Kuldip , Solan Gregory A. 
Published: August 2010

AbstractInteraction of cis,cis,trans‐[RuF2(CO)2(PPh3)2] (1a) with BF3 in acetonitrile affords the dicationic adduct [Ru(NCMe)2(CO)2(PPh3)2](BF4)(B2F7) (2), which can be readily carbonylated to form [Ru(CO)4(PPh3)2](BF4)2 (3). In contrast, reaction of 1a with BF3 in dichloromethane leads to the neutral ruthenium–fluoro species [RuF(FBF3)(CO)2(PPh3)2] (4); facile displacement of the bound FBF3 ligand in 4 occurs on treatment with CO or PPh3 to afford cationic [RuF(CO)2(L)(PPh3)2](BF4) [L = CO (5a), PPh3 (5b)]. On the other hand, reaction of 1a with PF5 in dichloromethane furnishes the coordinatively unsaturated 16‐electron salt [RuF(CO)2(PPh3)2](PF6) (6). Metathesis of the PF6 anion in 6 with KB(ArF)4 [ArF = 3,5‐(CF3)2C6H3] in dichloromethane results in rapid decomposition, while in the presence of CO solvent exchange (CH2Cl2) takes place to yield chloride‐containing [RuCl(CO)3(PPh3)2][B(ArF)4] (7). Unexpectedly, 1a proved unreactive towards tris(pentafluorophenyl)borane in dichloromethane. However, by substituting the triphenylphosphane ligands in 1a with better donor phosphanes or with an N‐heterocyclic carbene (NHC) [to give cis,cis,trans‐[RuF2(CO)2(L)2] [L = PEt2Ph (1b), P(CCPh)Ph2 (1c), IPr (1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) (1d)], fluoride abstraction could be achieved using B(C6F5)3 to give 16‐electron [RuF(CO)2(L)2][FB(C6F5)3] (L = PEt2Ph (8b), P(CCPh)Ph2 (8c), IPr (8d)]. Carbonylation of 8d proceeds smoothly to generate the coordinatively saturated species [RuF(CO)3(IPr)2][FB(C6F5)3] (9) in high yield. Single crystal X‐ray structures are presented for 2, 3, 5a/3, 7 and 9.
Mechanistic Studies on Fast Ligand‐Substitution Reactions of a Very Labile PdII Complex in Several Ionic Liquids
Authors: Kern Simon , Illner Peter , Begel Svetlana , van Eldik Rudi 
Published: August 2010

AbstractDetailed kinetic studies on the ligand‐substitution reactions of the very labile [Pd(terpy)Cl]+ (terpy = 2,2′:6′,2″‐terpyridine) complex have been performed for neutral and anionic nucleophiles in several imidazolium‐based ionic liquids. The detailed substitution mechanisms derived from the obtained rate and activation parameters differ from those expected on the basis of data aquired in aqueous medium, since the selected ionic liquids significantly affect the nucleophilic attack of the entering ligand on the complex. The rate constant for the substitution reaction with thiourea as entering nucleophile is much larger in water, viz. (7.8 ± 0.2) × 105 M–1 s–1, than in the ionic liquids [emim][NTf2] and [emim][EtOSO3], viz. (2.5 ± 0.1) × 104 and (1.8 ± 0.1) × 103 M–1 s–1 at 25 °C, respectively, which can be accounted for in terms of the protective interaction of the anionic components of the ionic liquids with the electrophilic metal centre.
Terahertz Time Domain Spectroscopy to Detect Low‐Frequency Vibrations of Double‐Walled Carbon Nanotubes
Authors: Kumar Sunil , Kamaraju Natrajan , Moravsky Alexander , Loutfy R. O. , Tondusson Marc , Freysz Eric , Sood Ajay Kumar 
Published: August 2010

AbstractWe have measured the frequency‐dependent real index of refraction and extinction coefficient (and hence the complex dielectric function) of a free‐standing double‐walled carbon nanotube film of thickness 200 nm by using terahertz time domain spectroscopy in the frequency range 0.1 to 2.5 THz. The real index of refraction and extinction coefficient have very high values of approximately 52 and 35, respectively, at 0.1 THz, which decrease at higher frequencies. Two low‐frequency phonon modes of the carbon nanotubes at 0.45 and 0.75 THz were clearly observed for the first time in the real and imaginary parts of the complex dielectric function along with a broad resonance centred at around 1.45 THz, the latter being similar to that in single‐walled carbon nanotubes assigned to electronic excitations. Our experiments bring out a possible application of double‐walled carbon nanotube films as a neutral density filter in the THz range.
Investigation of Steric and Electronic Factors of (Arylsulfonyl)phosphane‐Palladium Catalysts in Ethene Polymerization
Authors: Piche Laurence , Daigle Jean‐Christophe , Poli Rinaldo , Claverie Jerome P. 
Published: August 2010

Abstract(Arylsulfonyl)phosphane ligands, o‐Ar2PC6H4SO3H in which Ar is phenyl (Ph), naphthyl (Np), phenanthryl (Pa), or anthracenyl (An) were prepared. These bulky phosphanes were used to generate phosphanepalladium complexes [(o‐Ar2‐PC6H4SO3)PdMe(pyridine)]. These complexes catalyze ethene polymerization and yield linear polyethene. The catalytic activity of these compounds and the molecular weight of the polymer decreases in the following order: Ph > Np > Pa > An, which corresponds to increasing cone angles and decreasing basicity.
1‐Alkoxyamino‐2‐nitroalkanes as Key Building Blocks for a Chemo‐ and Diastereoselective Synthesis of a New Type of Polyfunctionalized N‐Alkoxypiperidine
Authors: López‐García M. Ángeles , Maya Inés , Fernández‐Bolaños José G. , Bosica Giovanna , Ballini Roberto 
Published: August 2010

AbstractA highly efficient conversion of β‐nitrostyrenes into a new kind of functionalized N‐alkoxy‐2‐hydroxypiperidine in two steps was developed, giving excellent yields and diastereoselectivity. The prepared compounds are the first examples of N‐alkoxy‐2‐hydroxypiperidines. The synthetic approach involved the conjugate addition of alkoxyamines to β‐nitrostyrenes, followed by Michael addition of the isolated nitroalkoxyamines to α,β‐unsaturated carbonyl compounds, and intramolecular addition of the alkoxyamino group to the carbonyl functionality of the (non‐isolated) adducts. Although three stereogenic centers are formed, only one diastereoisomer was detected. This unprecedented sequence of reactions can also be performed in a one‐pot fashion.
Copper‐Catalyzed Double N‐Vinylation of Aromatic Amines: An Efficient Synthesis of Various Substituted N‐Arylpyrroles
Authors: Liao Qian , Zhang Liyun , Wang Fei , Li Shutao , Xi Chanjuan 
Published: August 2010

AbstractA simple and efficient approach to various substitutedN‐arylpyrroles has been developed. The method is based on the copper‐catalyzed sequential inter‐ and intramolecular N‐vinylation of aromatic amines. The reactions proceed to afford substituted N‐arylpyrroles in good‐to‐excellent yields using CuI as the precatalyst, tBuONa as the base, and N1,N2‐dimethylethane‐1,2‐diamine (DMEDA) as the ligand. Anilines with electron‐donating and ‐withdrawing substituents as well as a heteroaromatic amine performed very well under the conditions used. Tri‐ and tetrasubstituted dienyl diiodides also performed well under the reaction conditions and afforded the corresponding substituted N‐arylpyrroles in good yields. Products were also obtained in high yields with CuBr or CuCl as precatalyst.
Trichlorosilane‐Mediated Stereoselective Reduction of C=N Bonds
Authors: Guizzetti Stefania , Benaglia Maurizio 
Published: August 2010

AbstractThe reduction of C=N bonds represents a powerful and widely used transformation allowing new nitrogen‐containing stereocenters to be generated. Chiral amino groups are ubiquitous in a variety of bioactive molecules such as alkaloids, natural products, drugs, and medical agents, so the development of a catalytic stereoselective process for the preparation of enantiomerically enriched amines through ketoimine reduction is attracting increasing interest, especially in view of future industrial applications. Great efforts to develop efficient organocatalytic methods to perform enantioselective imine reductions and reductive amination processes have recently been made. In the last few years, trichlorosilane‐mediated reductions have received constantly increasing attention because the potential to generate chiral catalysts for imine reduction simply by coordination of HSiCl3 with a chiral Lewis base has allowed the development of several efficient organocatalytic systems. Here we offer a complete overview of different chiral promoters of stereoselective reductions with trichlorosilane, classified as N‐formyl derivatives, which may be considered historically the first class of compounds developed as chiral activators of trichlorosilane, picolinamide derivatives, and miscellaneous compounds presented in that order.
Acute‐phase proteins investigation based on lectins affinity capture prior to 2‐DE separation: Application to serum from multiple sclerosis patients
Authors: Robotti Andrea , Natale Massimo , Albo Alessandra Giuliano , Lis Katarzyna , Perga Simona , Marnetto Fabiana , Gilli Francesca , Bertolotto Antonio 
Published: August 2010

AbstractPlasma acute‐phase proteins (APPs) glyco‐isoforms are important biomarkers of inflammatory processes such as those occurring in multiple sclerosis (MS). Specific analysis of these proteins is often hampered by sample biochemical complexity. The aim of our study was to set up a method to accurately visualize, identify and quantify APPs glyco‐isoforms in human serum. An enrichment strategy based on affinity chromatography using the carbohydrate‐binding proteins concanavalin A (ConA) and erythrina cristagalli lectin (ECL) was applied to pooled serum samples from 15 patients and 9 healthy individuals. Image analysis of 2‐DE detected 30 spots with a fold change higher than 1.5. A total of 14 were statistically significant (p value<0.05): 7 up‐regulated and 7 down‐regulated in MS samples. ESI LC‐Nanospray IT mass spectrometry analysis confirmed that all of them were APPs isoforms supporting the idea that the accurate analysis of differential glycosylation profiles in these biomarkers is instrumental to distinguish between MS patients and healthy subjects. Additionally, overlaps in ConA/ECL maps protein patterns suggest how the used lectins are able to bind sugars harbored by the same oligosaccharide structure. Among identified proteins, the presence of complex and/or hybrid type N‐linked sugar structures is well known. Performing galectin‐3 binding and Western blotting, we were able to demonstrate a correlation between hybrid type glyco‐isoforms of β‐haptoglobin and MS. In conclusion, although the patho‐physiological role of the identified species still remains unclear and further validations are needed, these findings may have a relevant impact on disease‐specific marker identification approaches.
Systematische Einheiten in der Botanik
Authors: Rothmaler Werner 
Published: August 2010

AbstractAlle sich fortpflanzende Unterschiede, welche die Natur liefert, müssen dem Naturforscher heilig seyn, nicht nur um des Systems willen, sondern auch deshalb, weil die geringen Abweichungen zuweilen über die Gesetze, nach welchen sich die Vegetation richtet, so wie über die Verbreitung der Pflanzen, und selbst über manche geognostische Verhältnisse mehr Licht zu verbreiten versprechen, als weit wichtigere Unterschiede.
Strategic resource allocation in the human brain supports cognitive coordination of object and spatial working memory
Authors: Jackson Margaret C. , Morgan Helen M. , Shapiro Kimron L. , Mohr Harald , Linden David E.J. 
Published: August 2010

AbstractThe ability to integrate different types of information (e.g., object identity and spatial orientation) and maintain or manipulate them concurrently in working memory (WM) facilitates the flow of ongoing tasks and is essential for normal human cognition. Research shows that object and spatial information is maintained and manipulated in WM via separate pathways in the brain (object/ventral versus spatial/dorsal). How does the human brain coordinate the activity of different specialized systems to conjoin different types of information? Here we used functional magnetic resonance imaging to investigate conjunction‐ versus single‐task manipulation of object (compute average color blend) and spatial (compute intermediate angle) information in WM. Object WM was associated with ventral (inferior frontal gyrus, occipital cortex), and spatial WM with dorsal (parietal cortex, superior frontal, and temporal sulci) regions. Conjoined object/spatial WM resulted in intermediate activity in these specialized areas, but greater activity in different prefrontal and parietal areas. Unique to our study, we found lower temporo‐occipital activity and greater deactivation in temporal and medial prefrontal cortices for conjunction‐ versus single‐tasks. Using structural equation modeling, we derived a conjunction‐task connectivity model that comprises a frontoparietal network with a bidirectional DLPFC‐VLPFC connection, and a direct parietal‐extrastriate pathway. We suggest that these activation/deactivation patterns reflect efficient resource allocation throughout the brain and propose a new extended version of the biased competition model of WM. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
The effects of physical activity, education, and body mass index on the aging brain
Authors: Ho April J. , Raji Cyrus A. , Becker James T. , Lopez Oscar L. , Kuller Lewis H. , Hua Xue , Dinov Ivo D. , Stein Jason L. , Rosano Caterina , Toga Arthur W. , Thompson Paul M. 
Published: August 2010

AbstractNormal human aging is accompanied by progressive brain tissue loss and cognitive decline; however, several factors are thought to influence brain aging. We applied tensor‐based morphometry to high‐resolution brain MRI scans to determine whether educational level or physical activity was associated with brain tissue volumes in the elderly, particularly in regions susceptible to age‐related atrophy. We mapped the 3D profile of brain volume differences in 226 healthy elderly subjects (130F/96M; 77.9 ± 3.6 SD years) from the Cardiovascular Health Study‐Cognition Study. Statistical maps revealed the 3D profile of brain regions whose volumes were associated with educational level and physical activity (based on leisure‐time energy expenditure). After controlling for age, sex, and physical activity, higher educational levels were associated with ∼2–3% greater tissue volumes, on average, in the temporal lobe gray matter. After controlling for age, sex, and education, greater physical activity was associated with ∼2–2.5% greater average tissue volumes in the white matter of the corona radiata extending into the parietal‐occipital junction. Body mass index (BMI) was highly correlated with both education and physical activity, so we examined BMI as a contributing factor by including physical activity, education, and BMI in the same model; only BMI effects remained significant. This is one of the largest MRI studies of factors influencing structural brain aging, and BMI may be a key factor explaining the observed relationship between education, physical activity, and brain structure. Independent contributions to brain structure could not be teased apart as all these factors were highly correlated with one another. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Specific infiltration of langerin‐positive dendritic cells in EBV‐infected tonsil, Hodgkin lymphoma and nasopharyngeal carcinoma
Authors: Braz‐Silva Paulo Henrique , Vitale Sébastien , Butori Catherine , Guevara Nicolas , Santini José , Magalhães Marina , Hofman Paul , Doglio Alain 
Published: August 2010

AbstractWe report here the existence of a novel subset of langerin (CD207)‐positive, immature dendritic cells (DCs) (CD83neg) abundantly infiltrating Epstein Barr virus (EBV)‐infected areas in tonsil, Hodgkin lymphoma and nasopharyngeal carcinoma. These CD207+ DCs differ from conventional epidermal Langerhans cells in their lack of CD1a and CCR6 and their unusual tissue localization. CD207+ DC infiltration strongly correlates with EBV infection because it was neither detected in EBV negative specimens nor in tissues infected with other human viruses. These immature DCs might represent good candidates for induction of the EBV‐specific immune response.
Butyrate elicits a metabolic switch in human colon cancer cells by targeting the pyruvate dehydrogenase complex
Authors: Blouin Jean‐Marc , Penot Graziella , Collinet Martine , Nacfer Magali , Forest Claude , Laurent‐Puig Pierre , Coumoul Xavier , Barouki Robert , Benelli Chantal , Bortoli Sylvie 
Published: August 2010

AbstractButyrate, a short‐chain fatty acid produced by the colonic bacterial fermentation is able to induce cell growth inhibition and differentiation in colon cancer cells at least partially through its capacity to inhibit histone deacetylases. Since butyrate is expected to impact cellular metabolic pathways in colon cancer cells, we hypothesize that it could exert its antiproliferative properties by altering cellular metabolism. We show that although Caco2 colon cancer cells oxidized both butyrate and glucose into CO2, they displayed a higher oxidation rate with butyrate as substrate than with glucose. Furthermore, butyrate pretreatment led to an increase cell capacity to oxidize butyrate and a decreased capacity to oxidize glucose, suggesting that colon cancer cells, which are initially highly glycolytic, can switch to a butyrate utilizing phenotype, and preferentially oxidize butyrate instead of glucose as energy source to produce acetyl coA. Butyrate pretreated cells displayed a modulation of glutamine metabolism characterized by an increased incorporation of carbons derived from glutamine into lipids and a reduced lactate production. The butyrate‐stimulated glutamine utilization is linked to pyruvate dehydrogenase complex since dichloroacetate reverses this effect. Furthermore, butyrate positively regulates gene expression of pyruvate dehydrogenase kinases and this effect involves a hyperacetylation of histones at PDK4 gene promoter level. Our data suggest that butyrate exerts two distinct effects to ensure the regulation of glutamine metabolism: it provides acetyl coA needed for fatty acid synthesis, and it also plays a role in the control of the expression of genes involved in glucose utilization leading to the inactivation of PDC.
VEGF stimulates PKD‐mediated CREB‐dependent orphan nuclear receptor Nurr1 expression: Role in VEGF‐induced angiogenesis
Authors: Zhao Dezheng , Desai Sachin , Zeng Huiyan 
Published: August 2010

AbstractNew vessel formation is critical for solid tumor growth and it is primarily stimulated by the most potent angiogenic factor vascular endothelial growth factor (VEGF or VEGF‐A165). VEGF promotes endothelial cell proliferation by initiating signaling cascades to increase gene transcription. Recent works showed that VEGF potently and rapidly induces expression of orphan nuclear receptor Nurr1 in endothelial cells. However, the signaling pathway for VEGF‐induced Nurr1 expression and its role in VEGF‐induced endothelial cell proliferation and angiogenic response have not been examined. In our study, we first show that VEGF significantly induces expression of Nurr1 mRNA, protein and its promoter activity in cultured endothelial cells. Furthermore, the promoter analysis shows that deletion of the putative cAMP‐responsive element binding protein (CREB) site in the proximal region of the promoter markedly reduces VEGF‐induced promoter activity whereas deletion of the upstream NF‐κB site has moderate effect. Transfection of a dominant negative CREB mutant (K‐CREB) or mutation of this putative CREB site in the Nurr1 promoter attenuates VEGF‐induced Nurr1 expression. VEGF also stimulates the binding of nuclear CREB protein to its site in the Nurr1 promoter in vitro and in vivo. Moreover, using pharmacological inhibitors and molecular approaches, we show that VEGF‐induced CREB activation is largely mediated by protein kinase C‐dependent protein kinase D activation. Finally, our data indicate that knockdown of endogenous Nurr1 expression attenuates VEGF‐induced endothelial cell proliferation, migration and in vivo matrigel angiogenesis, suggesting its potential importance in mediating VEGF‐induced tumor angiogenesis.
Ethanol‐mediated carcinogenesis in the human esophagus implicates CYP2E1 induction and the generation of carcinogenic DNA‐lesions
Authors: Millonig Gunda , Wang Ying , Homann Nils , Bernhardt Friederike , Qin Hua , Mueller Sebastian , Bartsch Helmut , Seitz Helmut K. 
Published: August 2010

AbstractChronic alcohol consumption is a major risk factor for esophageal cancer. Various mechanisms may mediate carcinogenesis including the genotoxic effect of acetaldehyde and oxidative stress. Ethanol exerts its carcinogenic effect in the liver among othersviathe induction of cytochrome P450 2E1 (CYP2E1) and the generation of carcinogenic etheno‐DNA adducts. Here we investigated if such effects can also be observed in the human esophagus. We studied nontumorous esophageal biopsies of 37 patients with upper aerodigestive tract cancer and alcohol consumption of 102.3 ± 131.4 g/day (range: 15–600 g) as well as 16 controls without tumors (12 teetotalers and 4 subjects with a maximum of 25 g ethanol/day). CYP2E1, etheno‐DNA adducts and Ki67 as a marker for cell proliferation were determined immunohistologically. Chronic alcohol ingestion resulted in a significant induction of CYP2E1 (p= 0.015) which correlated with the amount of alcohol consumed (r= 0.6,p< 0.001). Furthermore, a significant correlation between CYP2E1 and the generation of the carcinogenic exocyclic etheno‐DNA adducts 1,N6‐ethenodeoxyadenosine (r= 0.93,p< 0.001) and 3,N4‐ethenodeoxycytidine (r= 0.92,p< 0.001) was observed. Etheno‐DNA adducts also correlated significantly with cell proliferation (p< 0.01), which was especially enhanced in patients who both drank and smoked (p< 0.001). Nonsmokers and nondrinkers had the lowest rate of cell proliferation, CYP2E1 expression and DNA lesions. Our data demonstrate for the first time an induction of CYP2E1 in the esophageal mucosa by ethanol in a dose dependent manner in man and may explain, at least in part, the generation of carcinogenic DNA lesions in this target organ.