bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clonally expanded plasma cells in the cerebrospinal fluid of MS patients produce myelin‐specific antibodies
Authors: von Büdingen Hans‐Christian , Harrer Melanie D. , Kuenzle Sandra , Meier Mirjam , Goebels Norbert 
Published: June 2008

AbstractClonally expanded plasma cells (cePC) and their presumed products, oligoclonal immunoglobulin G bands (OCB), are characteristic findings in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS). While cePC and OCB strongly suggest an involvement of B cell‐dependent immune mechanisms in the pathogenesis of MS, their actual pathological relevance and target antigens remain unknown. To further understand the potential role played by cePC, we generated a panel of monoclonal antibodies (MS‐mAb) from CSF‐derived cePC from four patients with early or definite MS. Single‐cell RT‐PCR of correctly paired heavy and light chain immunoglobulin genes from individual cePC ensured the subsequent resurrection of their original antigen specificity. Immunofluorescence stainings of MS lesion tissue with MS‐mAb revealed myelin reactivity in the cePC repertoire of all four patients and intracellular filament reactivity in one patient. While myelin staining by MS‐mAb was only rarely detectable in non‐MS CNS white matter tissue, it was greatly enhanced at the edge of demyelinating lesions in MS brain tissue. Our findings provide conclusive evidence for the presence of an antigen‐driven B cell response in the CSF of MS patients directed against epitopes present in areas of myelin degradation.
Yaa autoimmune phenotypes are conferred by overexpression of TLR7
Authors: Fairhurst Anna‐Marie , Hwang Sun‐hee , Wang Andrew , Tian Xiang‐Hong , Boudreaux Christopher , Zhou Xin J. , Casco Jose , Li Quan‐Zhen , Connolly John E. , Wakeland Edward K. 
Published: June 2008

AbstractThe Y‐linked autoimmune accelerating (Yaa) locus drives the transition to fatal lupus nephritis when combined with B6.Sle1 in our C57BL/6J (B6)‐congenic model of systemic autoimmunity. We and others recently demonstrated that the translocation of a cluster of X‐linked genes onto the Y chromosome is the genetic lesion underlying Yaa (Subramanian, S. et al., Proc. Natl. Acad. Sci. USA 2006. 103: 9970–9975; Pisitkun, P. et al., Science 2006. 312: 1669–1672). In male mice carrying Yaa, the transcription of several genes within the translocated segment is increased roughly twofold. Although the translocated X chromosome segment in Yaa may contain as many as 16 genes, the major candidate gene for causation of the Yaa‐associated autoimmune phenotypes has been TLR7. To confirm the role of TLR7 in Yaa‐mediated autoimmune phenotypes, we introgressed a targeted disruption of TLR7 (TLR7–) onto B6.Sle1Yaa to produce B6.Sle1YaaTLR7– and examined evidence of disease at 6 and 9 months of age. Our results demonstrate that the up‐regulation of TLR7 in the B6.Sle1Yaa strain is responsible for splenomegaly, glomerular nephritis and the majority of the cellular abnormalities of B, T and myeloid cells. The up‐regulation of TLR7 was also responsible for driving the infiltration and activation of leukocytes in the kidney, in which activated T cells were a primary component. However, the resolution of TLR7 up‐regulation did not eliminate the enhanced humoral autoimmunity observed in B6.SleYaa, suggesting that additional elements in the translocation may contribute to the disease phenotype.See accompanying commentary http://dx.doi.org/10.1002/eji.200838478
Interaction with XIAP prevents full caspase‐3/‐7 activation in proliferating human T lymphocytes
Authors: Paulsen Maren , Ussat Sandra , Jakob Marten , Scherer Gudrun , Lepenies Inga , Schütze Stefan , Kabelitz Dieter , Adam‐Klages Sabine 
Published: June 2008

AbstractCaspases are essential mediators of cytokine release and apoptosis. Additionally, caspase activity is required for the proliferation of naive T lymphocytes. It remained unclear how proliferating cells are able to cope with the pro‐apoptotic activity especially of effector caspases‐3 and ‐7. Possible reasons might include limited subcellular localization of active caspases or inhibition by endogenous caspase inhibitors. Here, we compared the activation of various caspases in proliferating human T cells with that in apoptotic cells. We show that cleaved caspases‐3/‐7 appear to be widely distributed in apoptotic cells while they are largely confined to the cytoplasm in proliferating cells. Additionally, in proliferating T cells caspase‐3 remains incompletely cleaved, while in apoptotic cells fully mature caspase‐3 is generated. We provide evidence that during T cell proliferation the intracellular caspase inhibitor X‐linked inhibitor‐of‐apoptosis protein (XIAP) interacts with caspases‐3/‐7, thereby blocking their full activation, substrate cleavage, and cell death. The lack of substrate cleavage might also lead to the observed limited subcellular distribution of caspases‐3/‐7. After induction of apoptosis, second mitochondria‐derived activator of caspases/direct inhibitor of apoptosis‐binding protein with low isoelectric point (Smac/DIABLO) is released from mitochondria, resulting in the abrogation of the inhibitory effect of XIAP, full activation of caspases‐3/‐7, and apoptosis.
Facile Gram‐Scale Growth of Single‐Crystalline Nanotetrapod‐Assembled ZnO Through a Rapid Process
Authors: Li Jianye , Peng Hongying , Liu Jie , Everitt Henry O. 
Published: June 2008

AbstractFrom a rapid combustion and catalyst‐free method, puresingle‐crystalline nanotetrapod‐assembled bulk nano‐ZnO was grown on a gram‐scale for the first time. The gram‐scale bulk nano‐ZnO is synthesized from ZnO powder with great reliability and repeatability, and also a high conversion efficiency. All four arms of the nanotetrapods are cone shaped and grow in the [001] direction. The photoluminescence properties of the nanotetrapod‐assembled ZnO were studied and a mechanism was suggested for the growth of the bulk nanotetrapod‐assembled ZnO. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis and Characterisation of Some New Zinc Carbamate Complexes Formed by CO2 Fixation and Their Use as Precursors for ZnO Particles under Mild Conditions
Authors: Domide Dan , Kaifer Elisabeth , Mautz Jürgen , Walter Olaf , Behrens Silke , Himmel Hans‐Jörg 
Published: June 2008

AbstractHerein we report on CO2 fixation by insertion into the Zn–N bonds of the two molecular compounds EtZnN(iPr)2 and EtZnN(iBu)2. The tetrameric carbamate complexes [EtZn(O2CNR2)]4 (R = iPr and iBu) were found to be the products of these reactions. The structures of the complexes were established by single‐crystal X‐ray diffraction. Thermal decomposition of the carbamate complexes was studied by applying a variety of different analytical techniques. These studies show that the compounds are suitable precursors for nanosized ZnO particles of ca. 10 nm diameter synthesised under mild conditions (< 200 °C) with the oxygen atoms originating from the reactant CO2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Structural Chemistry of Borazines
Authors: Anand Benadir , Nöth Heinrich , Schwenk‐Kircher Holger , Troll Alexander 
Published: June 2008

AbstractThe solid‐state structure of (HN=BF)3 has been redetermined. It is characterised by a stacking of the molecules, similar to hexagonal boron nitride. In contrast, (F3CH2N=BF)3 shows no intermolecular interactions between the planar borazine rings. In (Cl2BN=BCl)3, the Cl2B groups are almost perpendicularly oriented to the planar borazine ring and its B–Cl bonds are shorter than the Cl–B bonds to the ring boron atoms. Reactions of (Cl2BN=BCl)3 with Me3SiNMe2 allows a successive Cl/Me2N exchange. Depending on the molar ratio, the compounds [Cl(Me2N)BN=BCl]3, [(Me2N)2BN=BCl]3 and [(Me2N)2BN=BNMe2]3 are obtained. The latter two react with CH2Cl2 by B–N bond cleavage of one ring boron bonded Me2N group with formation of an N–H bond. These molecules not only possess a strongly distorted BN hexagon with short B–NH bonds but also a nonplanar borazine ring. The nonplanarity of the borazine ring is even more pronounced in [Me3SiN=BCl]3. A planar borazine ring is observed for (MeN=BBr)3. Its molecules are ordered into stacks by translation with borazine planes 4.2 Å apart from each other. Characteristic of the structure are close contacts between neighbouring bromine atoms. Due to the steric demand of pentafluorophenyl groups, the borazine ring of (F5C6N=BBr)3 forms no stacks because one of the three F5C6 rings stands almost perpendicular to the borazine plane while the other two are twisted by 70°. Aminolysis of (F5C6N=BBr)3 yields (F5C6N=BNH2)3 with NH2 groups that are coplanar with the borazine ring. The phenyl groups of (HN=BPh)3 are twisted by only 30–40° relative to the borazine ring. A threefold crystallographic axis stands perpendicular to the ring plane. The sixfold crystallographic axis of the unit cell generates a channel structure with an internal diameter of 4.5 Å. The two isomeric borazines, (iPrN=BMe)3 and (MeN=BiPr)3 are structurally rather similar although the first of these has longer B–N bonds due to the shorter N–C bonds. Moreover, the B–N–B and N–B–N bond angles are slightly different.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
β‐Diketonate, β‐Ketoiminate, and β‐Diiminate Complexes of Difluoroboron
Authors: Macedo Felipe P. , Gwengo Chengeto , Lindeman Sergey V. , Smith Mark D. , Gardinier James R. 
Published: June 2008

AbstractA series of β‐diketonate, keto(aryl)iminato, and β‐bis(aryl)iminato complexes of difluoroboron, twenty in total, have been prepared to assess the impact of chelate ring and aniline substitution on the structural, electrochemical, and photophysical properties of these ubiquitous chelates. DFT (B3LYP/6‐31G*) calculations supplemented the experimental results and both demonstrated that replacing oxygen with the more electron‐donating aniline groups serves to only fine‐tune the electronic properties because both the HOMO and LUMO energies are affected by such substitution. The electronic properties of all compounds are most greatly influenced by the nature of the substituents bound to the carbon portion of the chelate ring. Each difluoroboron complex undergoes two ligand‐based, one‐electron reductions where the first reduction potential becomes less favorable with increasing aniline substitution. Similarly, replacing oxygen with the more electron‐donating aniline groups gives rise to slightly red‐shifted absorption and emission processes. Substitution on the aniline ring has little, if any, influence on the electronic properties of the resultant complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Advances in Polynuclear Iron(II), Iron(III) and Cobalt(II) Spin‐Crossover Compounds
Authors: Murray Keith S. 
Published: June 2008

AbstractThis review describes the recent advances made in the syntheses, structures (including the use of synchrotron sources and variable‐temperature crystal structures and PXRD determinations of unit cell axes), magnetism, and photomagnetism of dinuclear and 1‐D chain spin‐crossover compounds of (primarily) iron(II), iron(III) and cobalt(II). It focuses on the work of the author's group and also includes a discussion of related work by other groups. In particular, the early and ongoing work by Kahn, Real, Gütlich and co‐workers on bipyrimidine‐bridged FeII dinuclear materials has been extended by us and others to include many other new bridging and capping ligands. This had led to a fuller understanding of the spin transitions that involve HS‐HS, HS‐LS and LS‐LS pair states. The same is being achieved for new 1‐D chain materials, and notable advances include structural observation of ordered and disordered metal centres and corresponding spin states. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Biocatalytic Cleavage of Alkenes with O2 and Trametes hirsuta G FCC 047
Authors: Lara Miguel , Mutti Francesco G. , Glueck Silvia M. , Kroutil Wolfgang 
Published: June 2008

AbstractAlkenes possessing a C=C double bond adjacent to an aromatic ring were cleaved to yield the corresponding carbonyl compounds by use of molecular oxygen as the sole oxidant and a cell‐free extract of the wood‐degrading fungus Trametes hirsuta FCC 047 as catalyst. The oxygen pressure required was optimized. Special adapted equipment allowed 96 reactions to be performed in parallel under controlled oxygen pressure. A broad spectrum of aryl‐alkenes was successfully converted into the corresponding ketones/aldehydes with excellent chemoselectivity under a controlled oxygen atmosphere (2 bar).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Intra‐ and Intermolecular C(sp2)–H···O Hydrogen Bonds in a Series of Isobenzofuranone Derivatives: Manifestation and Energetics
Authors: Niebel Claude , Lokshin Vladimir , Sigalov Mark , Krief Pnina , Khodorkovsky Vladimir 
Published: June 2008

AbstractDerivatives2–6were prepared as models for studying intra‐ and intermolecular C(sp2)–H···O hydrogen bonding. Their X‐ray structures confirm the presence of intramolecular hydrogen bonds in derivatives of the “a” series: the corresponding C···O distances vary between 2.91 and 2.97 Å. The corresponding13C–1H coupling constants are increased by about 7.5 Hz, and the1H chemical shifts in CDCl3are 9.1–10.7 ppm. No intramolecular hydrogen bonds can form in derivatives of the isomeric “b” series. In this series, the chemical shifts of the corresponding aromatic protons exhibit strong solvent dependency; in particular, they are as sensitive as the proton in chloroform to the presence of DMSO. The vinylic protons activated by the electron‐accepting COOR groups behave similarly. Quantum mechanical calculations in the gas phase and in DMSO reproduce the experimental observations. Energies of the intramolecular hydrogen bonds evaluated by two independent approaches vary between 3.7 and 4.4 kcal mol–1in the gas phase and still amount to at least 2.5 kcal mol–1in2ain DMSO. These estimates are practically independent of the computational method (HF, MP2, and DFT B3LYP were employed for derivatives2). We conclude that the behavior of both activated aromatic and vinylic C(sp2)–H atoms in the studied derivatives is qualitatively and quantitatively similar to the behavior of the C(sp3)–H atom in chloroform. The existence of hydrogen bonds involving these atoms can easily be detected by NMR spectroscopy.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
An analysis of three multiple access techniques for the uplink of future cellular mobile systems
Authors: Ciochina Cristina , Mottier David , Sari Hikmet 
Published: June 2008

AbstractOrthogonal frequency division multiple access (OFDMA) is today a part of many standard specifications. Despite its attractive features, it has two main drawbacks when employed in the uplink: the high peak‐to‐average power ratio (PAPR) inherited from orthogonal frequency division multiplexing (OFDM) and the inherent frequency diversity loss. The loss of frequency diversity can be alleviated by precoding. Variants of precoded OFDMA include spread spectrum multi‐carrier multiple access (SS‐MC‐MA) and the frequency‐domain implementation of single‐carrier (SC) FDMA. The latter transforms OFDMA into a SC transmission system, avoiding the PAPR problem. This paper analyses OFDMA, several variants of precoded OFDMA and SC‐FDMA in its frequency‐domain implementations and compares them for uplink transmission. Copyright © 2008 John Wiley & Sons, Ltd.
OFDM‐CDM with spatial pre‐coding in fading channels
Authors: Kaiser Stefan 
Published: June 2008

AbstractThis paper investigates the potential of orthogonal frequency division multiplexing‐code division multiplexing (OFDM‐CDM) for its application in future broadband mobile radio systems. The focus is on the performance analysis of OFDM‐CDM with spatial pre‐coding and its comparison with OFDM. Code division multiplexing (CDM) is an efficient coding scheme without rate loss. The investigations take into account the spatial diversity and pre‐coding schemes cyclic delay diversity (CDD), spatial phase coding (SPC), equal gain transmission (EGT) and maximum ratio transmission (MRT). SPC can closely approach the performance of optimum pre‐coding schemes, whereas SPC requires less complexity and overhead with respect to channel estimation and feedback information. Imperfections due to channel estimation are taken into account in the analysis. It can be shown that OFDM‐CDM with spatial pre‐coding applying single symbol detection as well as multi‐symbol detection outperforms OFDM with spatial pre‐coding. Copyright © 2008 John Wiley & Sons, Ltd.
Dual‐mode multi‐modulus algorithms for blind equalisation of QAM signals
Authors: Feng Liu , Lin‐dong Ge , Ye‐jin Wu 
Published: June 2008

AbstractA dual‐mode multi‐modulus algorithm (DM‐MMA) and a stop‐and‐go dual‐mode multi‐modulus algorithm (SAG‐DMMMA) for blind equalisation of high‐order quadrature amplitude modulation (QAM) signals are proposed. Simulation results show the proposed blind equalisation algorithms have faster convergence speed and smaller steady‐state mean square error, compared with the recently introduced multi‐modulus algorithm. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of alginate on innate immune activation of macrophages
Authors: Yang Dong , Jones Kim S. 
Published: June 2008

AbstractAlginate, a natural polysaccharide, has been widely used in tissue engineering and drug delivery, butlike other biomaterials, it causes inflammation by unknown mechanisms. We hypothesized that alginate would stimulate innate immune responses through macrophage receptors. In this study, we showed that sodium alginate induced activation of macrophage‐like cells (RAW264.7) through the NF‐κB pathway. Production of proinflammatory cytokines, such as IL‐1β, IL‐6, IL‐12, and TNF‐α was time and dose‐dependent. Treatment with alginate solution caused responses that closely paralleled stimulation by lipopolysaccharide in timing and magnitude. These data suggest that sodium alginate causes innate immune responses through NF‐κB activation and likely activates the same pathways as pathogen recognition. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
In vitro and in vivo studies of alkali‐ and heat‐treated Ti‐6Al‐7Nb and Ti‐5Al‐2Nb‐1Ta alloys for orthopedic implants
Authors: Tamilselvi S. , Raghavendran H. Balaji , Srinivasan P. , Rajendran N. 
Published: June 2008

AbstractIn vitro studies of Ti‐6Al‐7Nb and Ti‐5Al‐2Nb‐1Ta alloys were carried out by treating the specimens with 10M NaOH at 60°C for 24 h and subsequently heat‐treated at 600°C for 1 h. After the alkali and heat treatments, and on subsequent soaking in simulated body fluid (SBF), the morphological and compositional changes on the surface of the specimens were examined using scanning electron microscope attached with an energy‐dispersive electron probe X‐ray analyzer. The results revealed a dense and uniform bonelike apatite layer on the surface of treated substrates immersed in SBF solution. In vivo studies were carried out in rats to evaluate osteoconduction of Ti‐6Al‐7Nb and Ti‐5Al‐2Nb‐1Ta alloys surface after alkali and heat treatments compared with untreated titanium alloys as the control. The following titanium implants were prepared from these species: (1) control without implant; (2) untreated titanium implant; (3) alkali‐ and heat‐treated implant—the implants were immersed in 10M NaOH solution at 60°C for 24 h and subsequently heated at 600°C for 1 h. The specimens were inserted into the medial side of each tibia of rats. Histologically, direct bone contact with the implant surface was significantly higher in the alkali heat‐treated implants than the untreated titanium implants. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Cell growth as a sheet on three‐dimensional sharp‐tip nanostructures
Authors: Choi Chang‐Hwan , Heydarkhan‐Hagvall Sepideh , Wu Benjamin M. , Dunn James C. Y. , Beygui Ramin E. , Kim Chang‐Jin “CJ” 
Published: June 2008

AbstractCells in vivo encounter with and react to the extracellular matrix materials on a nanometer scale. Recent advances in nanofabrication technologies allowing the precise control of a nanostructure's pattern, periodicity, shape, and height have enabled a systematic study of cell interactions with three‐dimensional nanotopographies. In this report, we examined the behavior of human foreskin fibroblasts on well‐ordered dense arrays (post and grate patterns with a 230‐nm pitch) of sharp‐tip nanostructures with varying three‐dimensionalities (from 50 to 600 nm in structural height) over time—until a cell sheet was formed. Although cells started out smaller and proliferated slower on tall nanostructures (both posts and grates) than on smooth surfaces, they became confluent to form a sheet in 3 weeks. On grate patterns, significant cell elongation in alignment with the underlying pattern was observed and maintained over time. On tall nanostructures, cells grew while raised on sharp tips, resulting in a weak total adherence to the solid surface. A sheet of cells was easily peeled off from such surfaces, suggesting that nanoscale topographies can be used as the basis for cell‐sheet tissue engineering. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Bone growth is enhanced by novel bioceramic coatings on Ti alloy implants
Authors: Wang Chaoyuan , Karlis Gross A. , Anderson Gail I. , Dunstan Colin R. , Carbone Angelo , Berger Goerg , Ploska Ute , Zreiqat Hala 
Published: June 2008

AbstractCalcium phosphate ceramics are widely used as coating materials to orthopedic implants and are found to enhance initial bony ingrowth by stimulating osseous apposition to the implant surface. In this study, two novel calcium orthophosphate materials were selected for coating onto the commonly used orthopedic implant material Ti‐6Al‐ 4V. One was calcium alkali orthophosphate with the crystalline phase Ca10[K/Na](PO4)7 with a small addition of SiO2 (AW‐Si) and the other was calcium orthophosphate composed of 70 mol % fluorapatite, Ca10(PO4)6F2 and 30 mol % CaZr4(PO4)6 (FA7Z). The coated implants were placed in cortical and cortico‐cancellous bone of sheep femur for six weeks. Retrieved samples were tested for osseointegration and mechanical strength. It was found that both coatings produced enhanced bone/implant contact rate compared to the control when implanted in cortico‐cancellous bone. This study demonstrates that the two coatings have the capability of encouraging bone growth, and hence the potential for being used as coating materials on Ti implants. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009