bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photodissociation of Dibromobenzenes at 266 nm by the Velocity Imaging Technique
Authors: Zhang Xiao‐Peng , Wei Zheng‐Rong , Lee Wei‐Bin , Chao Ting‐Jung , Lin King‐Chuen 
Published: July 2008

AbstractA velocity imaging technique combined with (2+1) resonance‐enhanced multiphoton ionization (REMPI) is used to detect the primary Br(2P3/2) fragment in the photodissociation of o‐, m‐, and p‐dibromobenzene at 266 nm. The obtained translational energy distributions suggest that the Br fragments are produced via two dissociation channels. For o‐ and m‐dibromobenzene, the slow channel that yields an anisotropy parameter close to zero is proposed to stem from excitation of the lowest excited singlet (π,π*) state followed by predissociation along a repulsive triplet (n,σ*) state localized on the CBr bond. The fast channel that gives rise to an anisotropy parameter of 0.53–0.73 is attributed to a bound triplet state with smaller dissociation barrier. For p‐dibromobenzene, the dissociation rates are reversed, because the barrier for the bound triplet state becomes higher than the singlet–triplet crossing energy. The fractions of translational energy release are determined to be 6–8 and 29–40 % for the slow and fast channels, respectively; the quantum yields are 0.2 and 0.8, and are insensitive to the position of the substituent. The Br fragmentation from bromobenzene and bromofluorobenzenes at the same photolyzing wavelength is also compared to understand the effect of the number of halogen atoms on the phenyl ring.
Heparan sulfate proteoglycans: A GAGgle of skeletal‐hematopoietic regulators
Authors: Rodgers Kathryn D. , San Antonio James D. , Jacenko Olena 
Published: July 2008

AbstractThis review summarizes our current understanding of the presence and function of heparan sulfate proteoglycans (HSPGs) in skeletal development and hematopoiesis. Although proteoglycans (PGs) comprise a large and diverse group of cell surface and matrix molecules, we chose to focus on HSPGs owing to their many proposed functions in skeletogenesis and hematopoiesis. Specifically, we discuss how HSPGs play predominant roles in establishing and regulating niches during skeleto‐hematopoietic development by participating in distinct developmental processes such as patterning, compartmentalization, growth, differentiation, and maintenance of tissues. Special emphasis is placed on our novel hypothesis that mechanistically links endochondral skeletogenesis to the establishment of the hematopoietic stem cell (HSC) niche in the marrow. HSPGs may contribute to these developmental processes through their unique abilities to establish and mediate morphogen, growth factor, and cytokine gradients; facilitate signaling; provide structural stability to tissues; and act as molecular filters and barriers. Developmental Dynamics 237:2622–2642, 2008. © 2008 Wiley‐Liss, Inc.
Altered endochondral ossification in collagen X mouse models leads to impaired immune responses
Authors: Sweeney E. , Campbell M. , Watkins K. , Hunter C.A. , Jacenko O. 
Published: July 2008

AbstractDisruption of collagen X function in hypertrophic cartilage undergoing endochondral ossification was previously linked to altered hematopoiesis in collagen X transgenic (Tg) and null (KO) mice (Jacenko et al., [2002] Am J Pathol 160:2019–2034). Mice displayed altered growth plates, diminished trabecular bone, and marrow hypoplasia with an aberrant lymphocyte profile throughout life. This study identifies altered B220+, CD4+, and CD8+ lymphocyte numbers, as well as CD4+/fox3P+ T regulatory cells in the collagen X mice. Additionally, diminished in vitro splenocyte responses to mitogens and an inability of mice to survive a challenge with Toxoplasma gondii, confirm impaired immune responses. In concert, ELISA and protein arrays identify aberrant levels of inflammatory, chemo‐attractant, and matrix binding cytokines in collagen X mouse sera. These data link the disruption of collagen X function in the chondro‐osseous junction to an altered hematopoietic stem cell niche in the marrow, resulting in impaired immune function. Developmental Dynamics 237:2693–2704, 2008. © 2008 Wiley‐Liss, Inc.
Human primary corneal fibroblasts synthesize and deposit proteoglycans in long‐term 3‐D cultures
Authors: Ren R. , Hutcheon A.E.K. , Guo X.Q. , Saeidi N. , Melotti S.A. , Ruberti J.W. , Zieske J.D. , Trinkaus‐Randall V. 
Published: July 2008

AbstractOur goal was to develop a 3‐D multi‐cellular construct using primary human corneal fibroblasts cultured on a disorganized collagen substrate in a scaffold‐free environment and to use it to determine the regulation of proteoglycans over an extended period of time (11 weeks). Electron micrographs revealed multi‐layered constructs with cells present in between alternating parallel and perpendicular arrays of fibrils. Type I collagen increased 2–4‐fold. Stromal proteoglycans including lumican, syndecan4, decorin, biglycan, mimecan, and perlecan were expressed. The presence of glycosaminoglycan chains was demonstrated for a subset of the core proteins (lumican, biglycan, and decorin) using lyase digestion. Cuprolinic blue–stained cultures showed that sulfated proteoglycans were present throughout the construct and most prominent in its mid‐region. The size of the Cuprolinic‐positive filaments resembled those previously reported in a human corneal stroma. Under the current culture conditions, the cells mimic a development or nonfibrotic repair phenotype. Developmental Dynamics 237:2705–2715, 2008. © 2008 Wiley‐Liss, Inc.
Maintenance of undifferentiated mouse embryonic stem cells in suspension by the serum‐ and feeder‐free defined culture condition
Authors: Tsuji Yukiiko , Yoshimura Naoko , Aoki Hitomi , Sharov Alexei A. , Ko Minoru S.H. , Motohashi Tsutomu , Kunisada Takahiro 
Published: July 2008

AbstractThe proven pluripotency of ES cells is expected to allow their therapeutic use for regenerative medicine. We present here a novel suspension culture method that facilitates the proliferation of pluripotent ES cells without feeder cells. The culture medium contains polyvinyl alcohol (PVA), free of either animal‐derived or synthetic serum, and contains very low amounts of peptidic or proteinaceous materials, which are favorable for therapeutic use. ES cells showed sustained proliferation in the suspension culture, and their undifferentiated state and pluripotency were experimentally verified. DNA microarray analyses showed a close relationship between the elevated expression of genes related to cell adhesions. We suggest that this suspension culture condition provides a better alternative to the conventional attached cell culture condition, especially for possible therapeutic use, by limiting the exposure of ES cells to feeder cells and animal products. Developmental Dynamics 237:2129–2138, 2008. © 2008 Wiley‐Liss, Inc.
Notch‐regulated oligodendrocyte specification from radial glia in the spinal cord of zebrafish embryos
Authors: Kim Ho , Shin Jimann , Kim Suhyun , Poling Justin , Park Hae‐Chul , Appel Bruce 
Published: July 2008

AbstractDuring vertebrate neural development, many dividing neuroepithelial precursors adopt features of radial glia, which are now known to also serve as neural precursors. In mammals, most radial glia do not persist past early postnatal stages, whereas zebrafish maintain large numbers of radial glia into adulthood. The mechanisms that maintain and specify radial glia for different fates are still poorly understood. We investigated formation of radial glia in the spinal cord of zebrafish and the role of Notch signaling in their maintenance and specification. We found that spinal cord precursors begin to express gfap+, a marker of radial glia, during neurogenesis and that gfap cells give rise to both neurons and oligodendrocytes. We also determined that Notch signaling is continuously required during embryogenesis to maintain radial glia, limit motor neuron formation and permit oligodendrocyte development, but that radial glia seem to be refractory to changes in Notch activity in postembryonic animals. Developmental Dynamics 237:2081–2089, 2008. © 2008 Wiley‐Liss, Inc.
Endogenous presentation of a nuclear antigen on MHC class II by autophagy in the absence of CRM1‐mediated nuclear export
Authors: Riedel Alexander , Nimmerjahn Falk , Burdach Stefan , Behrends Uta , Bornkamm Georg W. , Mautner Josef 
Published: July 2008

AbstractAccumulating evidence suggests that intracellular antigens are endogenously presented on MHC class II, but it is still unknown whether antigens within different subcellular compartments are presented with similar efficiency, and via the same or different pathways. We have previously shown that endogenous MHC class II presentation of the cytosolic bacterial antigen neomycin phosphotransferase II (NeoR) is mediated by autophagy. Here, we addressed whether secluding NeoR from this cytoplasmic pathway by directing the protein into the cell nucleus (NucNeoR) would affect antigen presentation. Unexpectedly, NucNeoR was presented at least as efficiently as the cytosolic version of the antigen. Furthermore, presentation of NucNeoR was also dependent on autophagocytosis and lysosomal processing, indicating that both antigens were presented via the same pathway. Inhibition of CRM1‐mediated nuclear export did not impede antigen presentation, indicating that NucNeoR gained access to this autophagy‐dependent MHC class II presentation pathway by a CRM1‐independent route. Thus, this endogenous presentation pathway broadens the spectrum of intracellular antigens surveyed by CD4+ T cells by efficiently sampling cytoplasmic as well as nuclear antigens.
SIGLEC16 encodes a DAP12‐associated receptor expressed in macrophages that evolved from its inhibitory counterpart SIGLEC11 and has functional and non‐functional alleles in humans
Authors: Cao Huan , Lakner Ursula , de Bono Bernard , Traherne James A. , Trowsdale John , Barrow Alexander D. 
Published: July 2008

AbstractSialic acid binding immunoglobulin‐like lectins (Siglec) are important components of immune recognition. The organization of Siglec genes in different species is consistent with rapid selection imposed by pathogens. We studied SIGLEC11 genes in human, rodent, dog, cow and non‐human primates. The lineages of SIGLEC11 genes in these species have undergone dynamic gene duplication and conversion, forming a potential inhibitory (SIGLEC11)/activating (SIGLEC16) receptor pair in chimpanzee and humans. A cDNA encoding human Siglec‐16, currently classed as a pseudogene in the databases (SIGLECP16), is expressed in various cell lines and tissues. A polymorphism screen for the two alleles (wild type and four‐base pair deletion, 4bpΔ) of SIGLEC16 found their frequencies to be 50% amongst the UK population. A search for donor sequences for SIGLEC16 revealed a subfamily of activating Siglec with charged transmembrane domains predicted to associate with ITAM‐encoding adaptor proteins. In support of this, Siglec‐16 was expressed at the cell surface in the presence of DAP12, but not the FcRγ chain. Using antisera specific to the cytoplasmic tail of Siglec‐16, we identified Siglec‐16 expression in CD14+ tissue macrophages and in normal human brain, cancerous oesophagus and lung. This is the first activating human Siglec receptor found to have functional and non‐functional alleles within the population.Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/38078_s.pdf
Distinct molecular composition of blood and lymphatic vascular endothelial cell junctions establishes specific functional barriers within the peripheral lymph node
Authors: Pfeiffer Friederike , Kumar Varsha , Butz Stefan , Vestweber Dietmar , Imhof Beat A. , Stein Jens V. , Engelhardt Britta 
Published: July 2008

AbstractLymph nodes are strategically localized at the interfaces between the blood and lymphatic vascular system, delivering immune cells and antigens to the lymph node. As cellular junctions of endothelial cells actively regulate vascular permeability and cell traffic, we have investigated their molecular composition by performing an extensive immunofluorescence study for adherens and tight junction molecules, including vascular endothelium (VE)‐cadherin, the vascular claudins 1, 3, 5 and 12, occludin, members of the junctional adhesion molecule family plus endothelial cell‐selective adhesion molecule (ESAM)‐1, platelet endothelial cell adhesion molecule‐1, ZO‐1 and ZO‐2. We found that junctions of high endothelial venules (HEV), which serve as entry site for naive lymphocytes, are unique due to their lack of the endothelial cell‐specific claudin‐5. LYVE‐1+ sinus‐lining endothelial cells form a diffusion barrier for soluble molecules that arrive at the afferent lymph and use claudin‐5 and ESAM‐1 to establish characteristic tight junctions. Analysis of the spatial relationship between the different vascular compartments revealed that HEV extend beyond the paracortex into the medullary sinuses, where they are protected from direct contact with the lymph by sinus‐lining endothelial cells. The specific molecular architecture of cellular junctions present in blood and lymphatic vessel endothelium in peripheral lymph nodes establishes distinct barriers controlling the distribution of antigens and immune cells within this tissue.Supporting Information for this article can be found at http//www.wiley‐vch.de/contents/jc_2040/2008/38140_s.pdf
Co‐inhibitory roles for glucocorticoid‐induced TNF receptor in CD1d‐dependent natural killer T cells
Authors: Chen Shuming , Ndhlovu Lishomwa C. , Takahashi Takeshi , Takeda Kazuyoshi , Ikarashi Yoshinori , Kikuchi Toshiaki , Murata Kazuko , Pandolfi Pier Paolo , Riccardi Carlo , Ono Masao , Sugamura Kazuo , Ishii Naoto 
Published: July 2008

AbstractInvariant natural killer T (iNKT) cells are a special subset of αβ T cells with invariant TCR, which recognize α‐galactosylceramide (α‐GalCer) presented by CD1d. In addition to signals through the invariant TCR upon stimulation with α‐GalCer, costimulatory signals, such as signals through CD28 and OX40, are indispensable for full activation of iNKT cells. In this study, we investigated the functions of a well‐known costimulatory molecule, glucocorticoid‐induced TNF receptor (GITR), on Ag‐induced iNKT cell activation. Unexpectedly, engagement of GITR by agonistic mAb DTA‐1 suppressed proliferation and cytokine production of iNKT cells upon α‐GalCer stimulation. In addition, GITR signals in iNKT cells during only the Ag‐priming phase was sufficient to inhibit the iNKT cell activation. Consistent with these results, the GITR‐deficient iNKT cells showed enhanced proliferation and increased cytokine production upon α‐GalCer stimulation both in vitro and in vivo. Furthermore, the in vivo administration of α‐GalCer suppressed tumor metastasis more efficiently in GITR‐deficient mice than in wild‐type mice. Collectively, GITR plays a co‐inhibitory role in Ag‐induced iNKT cell activation.
A subset of IL‐10‐producing γδ T cells protect the liver from Listeria‐elicited, CD8+ T cell‐mediated injury
Authors: Rhodes Katherine A. , Andrew Elizabeth M. , Newton Darren J. , Tramonti Daniela , Carding Simon R. 
Published: July 2008

AbstractAlthough γδ T cells play a role in protecting tissues from pathogen‐elicited damage to bacterial, viral and parasitic pathogens, the mechanisms involved in the damage and in the protection have not been clearly elucidated. This has been addressed using a murine model of listeriosis, which in mice lacking γδ T cells (TCRδ–/–) is characterised by severe and extensive immune‐mediated hepatic necrosis. We show that these hepatic lesions are caused by Listeria‐elicited CD8+ T cells secreting high levels of TNF‐α that accumulate in the liver of Listeria‐infected TCRδ–/– mice. Using isolated populations of γδ T cells from wild‐type and cytokine‐deficient strains of mice to reconstitute TCRδ–/– mice, the TCR variable gene 4 (Vγ4)+ subset of γδ T cells was shown to protect against liver injury. Hepatoprotection was dependent upon their ability to produce IL‐10 after TCR‐mediated interactions with Listeria‐elicited macrophages and CD8+ T cells. IL‐10‐producing Vγ4+ T cells also contribute to controlling CD8+ T cell expansion and to regulating and reducing TNF‐α secretion by activated CD8+ T cells. This effect on TNF‐α production was directly attributed to IL‐10. These findings identify a novel mechanism by which pathogen‐elicited CD8+ T cells are regulated via interactions with, and activation of, IL‐10‐producing hepatoprotective γδ T cells.
Synthesis of Single‐Crystal Gold Nano‐ and Microprisms Using a Solvent‐Reductant‐Template Ionic Liquid
Authors: Gao Yanan , Voigt Andreas , Zhou Min , Sundmacher Kai 
Published: July 2008

AbstractA single‐step procedure to obtain variable‐sized nano‐ and microprisms of gold in ionic liquids is presented. Using an ionic liquid, 1‐butyl‐3‐methylimidazolium hexafluorophosphate (bmimPF6), as a solvent for the Au precursor as well as the reducing reagent for the reaction, one can control the size of the produced gold nanostructures. By varying the reaction time, prismatic particles with a very broad size range of 3–20 μm in diameter and 10–400 nm in thickness were obtained. Using an alternative ionic liquid, 1‐butyl‐3‐methylimidazolium bis(trifluoromethanesulfonimide) (bmimTf2N), uniform, single‐crystal nano‐ and microprisms with an even larger size of about 100 μm in diameter were prepared. Large gold prisms of this type could be useful as a support for adsorbed species, as functional thin films, or as a conducting support for molecular electronics.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Analytical evaluation of six monovarietal virgin olive oils from Northern Tunisia
Authors: Haddada Faouzia M. , Krichène Dhouha , Manai Hédia , Oueslati Imen , Daoud Douja , Zarrouk Mokhtar 
Published: July 2008

AbstractThe characterization of virgin olive oils from six Tunisian cultivars, namely Chétoui, Ain Jarboua, Jarboui, Regregui, Rekhami and Neb Jmel, grown in Nebeur (a region of the Kef) was carried out. These cultivars dominate their natural habitats, but with the exception of the Chétoui cultivar they are only scattered throughout the nation. Several analytical parameters were evaluated; these include quality index, fatty acid composition, chlorophylls, carotenoids, sterols, α‐tocopherol and phenolic compounds. Their relationship with oxidative stability was also tested. The main phenols found were tyrosol, hydroxytyrosol, the dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol, oleuropein aglycon and pinoresinol. These phenolic compounds, the colorimetric total phenol content and o‐diphenols showed significant correlations with oxidative stability. Furthermore, most of the analytical parameters of the oils that were determined in this study were greatly influenced by genetic factors (cultivar).
The concentration of tocols from rice bran oil deodorizer distillate using solvent
Authors: Ko Soon‐Nam , Lee Sun‐Mi , Kim In‐Hwan 
Published: July 2008

AbstractTocols (tocopherols + tocotrienols) have been concentrated efficiently from rice bran oil (RBO) deodorizer distillate using solvent at low temperature. The levels of total tocols, total tocopherols, and total tocotrienols in RBO deodorizer distillate (starting material) were 31.5, 14.9, and 16.6 mg/g, respectively. Nine different solvents were tested, and acetonitrile was selected as the optimal solvent for concentrating tocols from the RBO deodorizer distillate. There was a significant (p <0.05) increase in the tocol level of the liquid fractions with decreasing temperature, for incubation temperatures up to –20 °C. In addition, significant differences (p <0.05) were observed in the relative percentages of α‐tocopherol, γ‐tocopherol, α‐tocotrienol, and γ‐tocotrienol between the raw sample and liquid fractions obtained at different temperatures using acetonitrile as the solvent. The concentration of the tocols from the RBO deodorizer distillate was temperature dependent, and a maximum of 89.9 mg/g was attained in the liquid fraction at – 40 °C. The relative percentage of tocotrienol homologs in the liquid fraction obtained at – 40 °C was approximately 80%. With acetonitrile as the solvent, the optimal temperature for concentrating the tocols from RBO deodorizer distillate was –20 °C when yield was considered.
Oxidation of unsaturated fatty acid derivatives and vegetable oils
Authors: Köckritz Angela , Martin Andreas 
Published: July 2008

AbstractThe present review reports the current literature of the last 10 years on selective oxidation reactions of fatty acid derivatives and vegetable oils. The work is structured in divisions including epoxidation, radical oxidations, Wacker‐type oxidation, dihydroxylation and C=C double bond cleavage.
Factors affecting the separation of the reaction mixture after transesterification of rapeseed oil
Authors: Hájek Martin , Skopal František 
Published: July 2008

AbstractThe most used method of biodiesel production is the transesterification of vegetable oils by a basic homogeneous catalyst. A heterogeneous reaction mixture is formed by this process which contains two phases: an ester phase and a glycerol phase. From this mixture, biodiesel is gained by sedimentation. The quality and quantity of both phases are affected by the conditions of the sedimentation process. It was studied how the conditions (independent variables: temperature of separation, amount of added water, time of sedimentation, etc.) affect the quantity and the quality of both phases (dependent variables). The Plackett–Burman statistic system was used for experiment planning. The relationship between independent and dependent variables was found and described by multidimensional linear regression. The created model allows the calculation of the optimum conditions of biodiesel production so that the quality of the biodiesel fulfills the EN 14214.
Enzymatic biodiesel production: Technical and economical considerations
Authors: Nielsen Per Munk , Brask Jesper , Fjerbaek Lene 
Published: July 2008

AbstractIt is well documented in the literature that enzymatic processing of oils and fats for biodiesel is technically feasible. However, with very few exceptions, enzyme technology is not currently used in commercial‐scale biodiesel production. This is mainly due to non‐optimized process design and a lack of available cost‐effective enzymes. The technology to re‐use enzymes has typically proven insufficient for the processes to be competitive. However, literature data documenting the productivity of enzymatic biodiesel together with the development of new immobilization technology indicates that enzyme catalysts can become cost effective compared to chemical processing. This work reviews the enzymatic processing of oils and fats into biodiesel with focus on process design and economy.
TBD‐Catalyzed Direct 5‐ and 6‐enolexo Aldolization of Ketoaldehydes
Authors: Ghobril Cynthia , Sabot Cyrille , Mioskowski Charles , Baati Rachid 
Published: July 2008

AbstractTreatment of unfunctionalized acyclic ketoaldehydes with a catalytic amount of 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene induces a direct intramolecular 5‐ and 6‐enolexo aldolization, furnishing 2‐ketocyclopentanols and 2‐ketocyclohexanols in good‐to‐excellent yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)