bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic and phenotypic analysis of B‐cell post‐transplant lymphoproliferative disorders provides insights into disease biology
Authors: Vakiani Efsevia , Basso Katia , Klein Ulf , Mansukhani Mahesh M. , Narayan Gopeshwar , Smith Paula M. , Murty Vundavalli V. , Dalla‐Favera Riccardo , Pasqualucci Laura , Bhagat Govind 
Published: May 2008

AbstractB‐cell post‐transplant lymphoproliferative disorders (PTLD) are classified as early lesions, polymorphic lymphomas (P‐PTLD) and monomorphic lymphomas (M‐PTLD). These morphologic categories are thought to reflect a biologic continuum, although supporting genetic data are lacking. To gain better insights into PTLD pathogenesis, we characterized the phenotypes, immunoglobulin (Ig) gene alterations and non‐Ig gene (BCL6, RhoH/TTF, c‐MYC, PAX5, CIITA, BCL7A, PIM1) mutations of 21 PTLD, including an IM‐like lesion, 8 P‐PTLD and 12 M‐PTLD. Gene expression profile analysis was also performed in 12 cases. All PTLD with clonal Ig rearrangements showed evidence of germinal centre (GC) transit based on the analysis of Ig and BCL6 gene mutations, and 74% had a non‐GC phenotype (BCL6 ± MUM1+). Although surface Ig abnormalities were seen in 6/19 (32%) PTLD, only three showed ‘crippling’ Ig mutations indicating other etiologies for loss of the B‐cell receptor. Aberrant somatic hypermutation (ASHM) was almost exclusively observed in M‐PTLD (8/12 vs. 1/8 P‐PTLD) and all three recurrent cases analysed showed additional mutations in genes targeted by ASHM. Gene expression analysis showed distinct clustering of PTLD compared to B‐cell non‐Hodgkin lymphomas (B‐NHL) without segregation of P‐PTLD from non‐GC M‐PTLD or EBV+ from EBV− PTLD. The gene expression pattern of PTLD appeared more related to that of memory and activated B‐cells. Together, our results suggest that PTLD represent a distinct type of B‐NHL deriving from an antigen experienced B‐cell, whose evolution is associated with accrual of genetic lesions. Copyright © 2008 John Wiley & Sons, Ltd.
Prostaglandin F2α induces the normoxic activation of the hypoxia‐inducible factor‐1 transcription factor in differentiating 3T3‐L1 preadipocytes: Potential role in the regulation of adipogenesis
Authors: Liu Li , Clipstone Neil A. 
Published: May 2008

AbstractProstaglandin F2α (PGF2α) is a potent paracrine inhibitor of adipocyte differentiation. Here we show that treatment of differentiating 3T3‐L1 preadipocytes with PGF2α induces the expression of DEC1, a transcriptional repressor that has previously been implicated in the inhibition of adipogenesis in response to hypoxia as a downstream effector of the hypoxia‐inducible factor‐1 (HIF‐1) transcription factor. Surprisingly, despite performing our experiments under normal ambient oxygen conditions, we find that treatment of differentiating 3T3‐L1 preadipocytes with PGF2α also results in the marked activation of HIF‐1, as measured by an increase in the accumulation of the HIF‐1α regulatory subunit. However, unlike the effects of hypoxia, this PGF2α‐induced normoxic increase in HIF‐1α is not mediated by an increase in the stability of the HIF‐1α polypeptide, rather we find that PGF2α selectively increases the expression of the alternatively spliced HIF‐1α I.1 mRNA isoform. Significantly, we demonstrate that the shRNA‐mediated knockdown of endogenous HIF‐1α expression attenuates the PGF2α‐induced expression of DEC1, overcomes the inhibitory effects of PGF2α on the expression of proadipogenic transcription factors C/EBPα and PPARγ and partially rescues the PGF2α‐induced inhibition of adipogenesis. Taken together, these results indicate that PGF2α promotes the activation of the HIF‐1 transcription factor pathway under normal oxygen conditions, and highlight a potential role for the normoxic activation of the HIF‐1/DEC1‐pathway in mediating the inhibitory effects of PGF2α on adipocyte differentiation. J. Cell. Biochem. 105: 89–98, 2008. © 2008 Wiley‐Liss, Inc.
C‐type natriuretic peptide regulation of limb mesenchymal chondrogenesis is accompanied by altered N‐cadherin and collagen type X‐related functions
Authors: Alan Tulay , Tufan A. Cevik 
Published: May 2008

AbstractAMDM, a form of osteochondrodysplasia, is due to the loss‐of‐function mutations in NPR‐B gene. This study investigated the functional involvement of CNP‐3, chick homolog of human CNP, and its receptor NPR‐B in chondrogenesis utilizing the micromass culture of the chick limb mesenchymal cells. Results revealed CNP‐3 and NPR‐B expression in the chick limb bud making stage‐specific peak levels first at Hamburger‐Hamilton stage 23–24, and second at stage 30–31, corresponding to pre‐chondrogenic mesenchymal condensation and initiation of chondrogenic maturation‐hypertrophy in vivo, respectively. CNP‐3 and NPR‐B expression in vitro increased parallel to collagen type X expression, but not to that of collagen type II. Treatment of cultures with CNP significantly increased N‐cadherin, and collagen type X expression, glycosaminoglycan synthesis and chondrogenesis. Collagen type II expression was not significantly affected. Thus, results implicated CNP‐3/NPR‐B signaling in pre‐chondrogenic mesenchymal condensation, glycosaminoglycan synthesis and late differentiation of chondrocytes in the process of endochondral ossification. J. Cell. Biochem. 105: 227–235, 2008. © 2008 Wiley‐Liss, Inc.
A tandem MS precursor‐ion scan approach to identify variable covalent modification of albumin Cys34: a new tool for studying vascular carbonylation
Authors: Aldini Giancarlo , Regazzoni Luca , Orioli Marica , Rimoldi Isabella , Facino Roberto Maffei , Carini Marina 
Published: May 2008

AbstractWe developed a liquid chromatography electrospray ionisation multi‐stage mass spectrometry (LC‐ESI‐MS/MS) approach based on precursor‐ion scanning and evaluated it to characterize the covalent modifications of Cys34 human serum albumin (HSA) caused by oxidative stress and reactive carbonyl species (RCS) adduction. HSA was isolated and digested enzymatically to generate a suitable‐length peptide (LQQCPF) containing the modified tag residue. The resulting LQQCPF peptides were identified by LC‐ESI‐MS/MS in precursor‐ion scan mode and further characterized in product‐ion scan mode. The product ions for precursor‐ion scanning were selected by studying the MS/MS fragmentation of a series of LQQCPF derivatives containing Cys34 modified with different α,β‐unsaturated aldehydes and di and ketoaldehydes. We used a Boolean logic to enhance the specificity of the method: this reconstitutes a virtual current trace (vCT) showing the peaks in the three precursor‐ion scans, marked by the same parent ion. The method was first evaluated to identify and characterize the Cys34 covalent adducts of HSA incubated with 4‐hydroxy‐hexenal, 4‐hydroxy‐trans‐2‐nonenal (HNE) and acrolein (ACR). Then we studied the Cys34 modification of human plasma incubated with mildly oxidized low‐density lipoproteins (LDL), and the method easily identified the LQQCPF adducts with HNE and ACR. In other experiments, plasma was oxidized by 2,2'‐azobis(2‐amidinopropane) HCl (AAPH) or by Fe2+/H2O2. In both conditions, the sulfinic derivative of LQQCPF was identified and characterized, indicating that the method is suitable not only for studying RCS‐modified albumin, but also to check the oxidative state of Cys34 as a marker of oxidative damage. Copyright © 2008 John Wiley & Sons, Ltd.
Study of synthetic complex esters as automotive gear lubricants
Authors: Nagendramma Ponnekanti , Kaul Savita 
Published: May 2008

AbstractA number of di‐ and triol‐centered polyols such as 2, 2‐dimethyl‐1, 3‐propane diol, 2, 2‐diethyl‐1, 3‐propane diol and 1, 1, 1‐tris hydroxy methyl propane complex esters have been synthesized using di‐carboxylic acids like adipic and sebacic acids (C6–C10) and 2‐ethyl 1‐hexanol with indigenous ion‐exchange resin (Indion‐130) catalyst. The applicability of these esters as automotive gear lubricants has been evaluated. The products were found to be compatible with extreme pressure additives. In addition, the products are readily biodegradable. Copyright © 2008 John Wiley & Sons, Ltd.
Hydrophilic interaction and reversed‐phase ultra‐performance liquid chromatography TOF‐MS for metabonomic analysis of Zucker rat urine
Authors: Gika Helen G. , Theodoridis Georgios A. , Wilson Ian D. 
Published: May 2008

AbstractHydrophilic interaction chromatography (HILIC) provides a complementary technique to RP methods for the retention of polar analytes for LC‐MS‐based metabonomic studies. Combining the advantages of both RP and HILIC separations with the efficient and rapid separations obtained using sub‐2 μm particles via the recently introduced ultra‐performance LC (UPLC) enables increased coverage of the metabolites present in biological samples to be achieved. Here an HILIC‐UPLC‐MS method was developed to provide metabolite profiles for urine samples obtained from male Zucker rats. The resulting data were compared with results obtained for the same samples by RP‐UPLC‐MS and demonstrated the complementary nature of the two separations with both methods enabling discrimination between the different sample types. Interestingly sample type differentiation was based on different markers.
Adsorption of plasmid DNA on anion exchange chromatography media
Authors: Tarmann Christina , Jungbauer Alois 
Published: May 2008

AbstractAnion exchange chromatography (AEC) is a useful and effective tool for DNA purification, but due to average pore sizes between 40 and 100 nm most AEC resins lack truly useful binding capacities for plasmid DNA (pDNA). Equilibrium binding capacities and uptake kinetics of AEC media including conventional media (Source 30 Q, Q Sepharose HP), a polymer grafted medium (Fractogel EMD DEAE (M)), media with large pores (Celbeads DEAE, PL SAX 4000 Å 30 μm) and a monolithic medium (CIM‐DEAE) were investigated by batch uptake or shallow bed experiments at two salt concentrations. Theoretical and experimental binding capacities suggest that the shape of the pDNA molecule can be described by a rod with a length to diameter ratio of 20:1 and that the molecule binds in upright position. The arrangement of DNA like a brush at the surface can be considered as entropy driven, kind of self‐assembly process which is inherent to highly and uniformly charged DNA molecules. The initial phase of adsorption is very fast and levels off, associated with a change in mass transfer mechanism. Feed concentrations higher than 0.1 mg/mL pDNA pronounce this effect. Monolithic media showed the fastest adsorption rate and highest binding capacity with 13 mg pDNA per mL.
Simultaneous separation of hydrophilic and hydrophobic compounds by using an online HILIC‐RPLC system with two detectors
Authors: Wang Yuan , Lu Xin , Xu Guowang 
Published: May 2008

AbstractIn the present study, we developed a novel online hydrophilic interaction chromatography (HILIC)‐RPLC separation system for simultaneous separation of both hydrophilic and hydrophobic solutes in a complex sample with one injection. A HILIC Si column and a C18 column were hyphenated with an interface including two electronic 2‐position valves, a solvent pump, and a solute transfer column. By using column‐switching technique, the nonretained hydrophobic solutes were eluted out of the HILIC column and transferred into the C18 column to perform further separation. The hydrophilic solutes were separated on the HILIC column at the same time. One detector was equipped for each column to record the individual chromatograms. By separating a standard mixture and a traditional Chinese medicine (TCM) extract, the developed HILIC‐RPLC system demonstrates its potential for “entire‐components” separation of complex samples with improved peak capacity and throughput compared with the common single‐column LC.
Conducting Poly(anilineboronic acid) Nanostructures: Controlled Synthesis and Characterization
Authors: Deore Bhavana A. , Yu Insun , Woodmass Jarret , Freund Michael S. 
Published: May 2008

AbstractSelf‐doped poly(anilineboronic acid) (PABA) nanostructures have been prepared by chemical polymerization in an aqueous acid solution and aliphatic alcohols. In aliphatic alcohols, PABA is soluble under the polymerization conditions. According to 11B NMR studies, the formation of anionic tetrahedral boronate ester in aliphatic alcohols in the presence of fluoride forms the basis of self‐doped, soluble PABA. Transmission electron microscope images show the formation of nanostructures with different shapes and forms in different solvents after precipitation of the polymer as a result of ion exchange in the presence of 0.5 M HCl. The spectroscopic and cyclic voltammetric results confirm the formation of conducting PABA nanostructures in high yield. The conductivity of PABA thin films made from the nanostructures prepared in aqueous acid, methanol, ethanol and 1‐propanol is approximately 15 and 3.0, 2.1 and 1.9 S · cm−1, respectively. The conducting PABA nanostructures are processable since they are easily re‐dispersed in the various solvents up to approximately 5 mg · mL−1. UV‐vis kinetic measurements, XPS and 11B NMR results suggest that the formation of various nanostructures is influenced by the polymerization rate, the degree of self‐doping versus external doping, and the polarity of the solvents used. The PABA nanostructured films produced from these structures exhibit enhanced redox stability in a wider potential window in non‐aqueous media compared to polyaniline due to formation of six‐member heterocyclic complexes containing a boron‐imine dative bond resulting in a self‐doped self‐cross‐linked polymer. The degree of crosslinking depends on the nature of nanostructures. In non‐aqueous media, the self‐doped, self‐cross‐linked PABA nanostructured films are much less susceptible to cathodic and anodic degradation at extreme potentials, overcoming a major limitation of more common conducting polymers.magnified image
Weakly representable atom structures that are not strongly representable, with an application to first order logic
Authors: Ahmed Tarek Sayed 
Published: May 2008

AbstractLetn > 2. A weakly representable relation algebra that is not strongly representable is constructed. It is proved that the set of all n by n basic matrices forms a cylindric basis that is also a weakly but not a strongly representable atom structure. This gives an example of a binary generated atomic representable cylindric algebra with no complete representation. An application to first order logic is given. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on the axiomatisation of real numbers
Authors: Coquand Thierry , Lombardi L. Henri 
Published: May 2008

AbstractIs it possible to give an abstract characterisation of constructive real numbers? A condition should be that all axioms are valid for Dedekind reals in any topos, or for constructive reals in Bishop mathematics. We present here a possible first‐order axiomatisation of real numbers, which becomes complete if one adds the law of excluded middle. As an application of the forcing relation defined in [3, 2], we give a proof that the formula which specifies the maximum function is not provable in this theory. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On Keisler singular‐like models
Authors: Mohsenipour Shahram 
Published: May 2008

AbstractKeisler in [7] proved that for a strong limit cardinal κ and a singular cardinal λ, the transfer relation κ → λ holds. We analyze the λ ‐like models produced in the proof of Keisler's transfer theorem when κ is further assumed to be regular. Our main result shows that with this extra assumption, Keisler's proof can be modified to produce a λ ‐like model M with built‐in Skolem functions that satisfies the following two properties:(1) M is generated by a subset C of order‐type λ.(2) M can be written as union of an elementary end extension chain 〈Ni: i < δ 〉 such that for each i < δ, there is an initial segment Ci of C with Ci ⊆ Ni, and Ni ∩ (C \Ci) = ∅︁. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two‐weight norm inequalities for multilinear potential type integral operators
Authors: Li Wenming 
Published: May 2008

AbstractWe give a condition which is sufficient for the two‐weight (p, q) inequalities for multilinear potential type integral operators, where 1 < p ≤ q < ∞. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Global solutions with shock waves to the generalized Riemann problem for a class of quasilinear hyperbolic systems of balance laws II
Authors: Shao Zhi‐Qiang 
Published: May 2008

AbstractThis work is a continuation of our previous work. In the present paper, we study the existence and uniqueness of global piecewise C1 solutions with shock waves to the generalized Riemann problem for general quasilinear hyperbolic systems of conservation laws with linear damping in the presence of a boundary. It is shown that the generalized Riemann problem for general quasilinear hyperbolic systems of conservation laws with linear damping with nonlinear boundary conditions in the half space {(t, x) | t ≥ 0, x ≥ 0} admits a unique global piecewise C1 solution u = u (t, x) containing only shock waves with small amplitude and this solution possesses a global structure similar to that of a self‐similar solution u = U (x /t) of the corresponding homogeneous Riemann problem, if each characteristic field with positive velocity is genuinely nonlinear and the corresponding homogeneous Riemann problem has only shock waves but no rarefaction waves and contact discontinuities. This result is also applied to shock reflection for the flow equations of a model class of fluids with viscosity induced by fading memory. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Discrete inertial manifolds
Authors: Pötzsche Christian 
Published: May 2008

AbstractThis work is devoted to attractive invariant manifolds for nonautonomous difference equations, occurring in the discretization theory for evolution equations. Such invariant sets provide a discrete counterpart to inertial manifolds of dissipative FDEs and evolutionary PDEs. We discuss their essential properties, like smoothness, the existence of an asymptotic phase, normal hyperbolicity and attractivity in a nonautonomous framework of pullback attraction.As application we show that inertial manifolds of the Allen–Cahn and complex Ginzburg–Landau equation persist under discretization. For the Ginzburg–Landau equation we can also estimate the dimension of the inertial manifold. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extension of Fréchet valued real analytic functions from subvarieties of ℝd
Authors: Vogt Dietmar 
Published: May 2008

AbstractIt is shown that for an algebraic subvariety X of ℝd every Fréchet valued real analytic function on X can be extended to a real analytic function on ℝd if and only if X is of type (PL), i.e. all of its singularities are of a certain type. Necessity of this condition is shown for any real analytic variety. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Influence of Pendant Carboxylic Acid Loading on Surfaces of Statistical Poly[(4‐hydroxystyrene)‐co‐styrene]s
Authors: Daugaard Anders Egede , Hvilsted Søren 
Published: May 2008

AbstractCopolymers of 4‐tert‐butoxystyrene (tBS) and styrene (S) have been prepared by free radical copolymerization and the copolymer ratios of rtBS = 0.97 and rS = 1.12 have been determined by the Kelen‐Tüdös method. After deprotection to 4‐hydroxystyrene, alkynes were introduced by a Williamson ether synthesis with propargyl bromide and the copolymers were functionalized with pendant aliphatic or aromatic carboxylic acids by click chemistry. Differential scanning calorimetry of the copolymers demonstrates the large influence on Tg of the different functional groups and the backbone composition. In particular, aliphatic and aromatic pendant groups differ by 92 °C in Tg. Contact angle measurements on spin coated films have shown a maximum effect of the functional groups in the advancing contact angle at a 75/100 copolymer loading. In addition to this, X‐ray photoelectron spectroscopy shows the presence of acid groups on the surface.magnified image
A Mathematical Model of the Bulk Copolymerization of Styrene and Acrylonitrile in the Presence of Polystyrene‐block‐Polybutadiene
Authors: Elizarrarás Daniel , Morales Graciela , de León Ramón Díaz , Luciani Carla , Estenoz Diana 
Published: May 2008

AbstractThe bulk copolymerization of styrene and acrylonitrile in the presence of SB using BPO as initiator was investigated. Reactions were carried out at 80 °C with different initial SB concentrations. Global variables, such as conversion and cumulative grafting efficiency of SAN, were determined during the prepolymerization. The isolated non‐grafted SAN was also analyzed to determine its average molar masses and composition. A mathematical model was developed, and theoretical predictions were compared with experimental data. A good agreement between measurements and simulations was obtained from a heterogeneous model when BPO was evenly distributed between phases.magnified image
Construction of different supramolecular polymer systems by combining the host–guest and hydrogen‐bonding interactions
Authors: Wang Yanping , Zhou Li , Sun Guoming , Xue Jie , Jia Zhifeng , Zhu Xinyuan , Yan Deyue 
Published: May 2008

AbstractPoly(ethylene glycol) (PEG) can form either the inclusion complex with α‐cyclodextrins (α‐CDs) through host–guest interactions or the interpolymer complex with poly(acrylic acid) (PAA) through hydrogen‐bonding interaction. Mixing α‐CD, PEG, and PAA ternary components in an aqueous solution, the competition between host–guest and hydrogen‐bonding interactions occurs. Increasing feed ratio of α‐CD:EG:AA from 0:1:1 to 0.2:1:1 (molar ratio), various interesting supramolecular polymer systems, such as hydrogen‐bonding complex, dynamic polyrotaxane, crystalline inclusion complex, and thermoresponsive hydrogel, are successively obtained. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1114–1120, 2008
Enhancing the electrochromic characteristics of conjugated polymer with TiO2 nano‐rods
Authors: Wu Chun‐Guey , Lu Ming‐I , Jhong Min‐Fong 
Published: May 2008

AbstractOrganic soluble, oleic acid capped TiO2 nano‐rod was well‐mixed with the electrochromic polymer: Poly‐(4,4‐dioctylcyclopenta[2,1‐b:3,4‐b′]‐dithiophene (PDOCPDT) to form TiO2/PDOCPDT nanocompsoite. TiO2/PDOCPDT film showed high electrochemical stability and its coloration efficiency is 1.5 times of that for pure PDOCPDT. The function of TiO2 nano‐rods can be regarded as a dispersion agent. PDOCPDT chains in TiO2/PDOCPDT may have a less aggregated structure and more open morphology, therefore has higher coloration efficiency. TiO2 may also act as electron transport or temporary electron storage centers, electrons can be transferred reversibly between PDOCPDT and TiO2 nano‐rods. TiO2/PDOCPDT is well‐soluble in CHCl3, large area thin films can be fabricated reproducibly simply by spin coating. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1121–1130, 2008