bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization and preliminary X‐ray analysis of a domain in the Runx2 transcription factor that interacts with the 1α,25 dihydroxy vitamin D3 receptor
Authors: Bruna Carola , Arriagada Gloria , Lian Jane B. , Stein Gary S. , Bunster Marta , Martinez‐Oyanedel Jose , Montecino Martin 
Published: January 2007

AbstractThe Runx2 transcription factor is a key regulator of osteoblast differentiation. In response to 1α,25 dihydroxy vitamin D3, Runx2 may interact with the 1α,25 dihydroxy vitamin D3 receptor (VDR) in the promoter of target genes, producing a synergic activation of their transcription. Previous studies have suggested that the motifs responsible for the VDR–Runx2 interaction are contained within the 230–361 domain of Runx2. In this work, we confirmed by GST‐pull down that Runx2I(209–361) is sufficient to interact with the VDR. To obtain structural information, GST–Runx2I(209–361) protein was overexpressed in Escherichia coli, purified and crystallized using the hanging‐drop vapor‐diffusion method and polyethyleneglycol as a precipitant. The crystals were found to diffract to a maximum resolution of 2.7 Å and a complete data set to a 3.3 Å resolution was collected and analyzed. The crystals belong to the tetragonal system, with a space group P4 and unit‐cell parameters of a = b = 90.8, and c = 57.2 Å. The presence of a monomer of the recombinant GST–Runx2I(209–361) in the asymmetric unit gives a VM of 2.7 Å3 Da−1 and a solvent content of 54.8%. J. Cell. Biochem. 101: 785–789, 2007. © 2007 Wiley‐Liss, Inc.
Transcriptional regulation of human Oct4 by steroidogenic factor‐1
Authors: Yang Heung‐Mo , Do Hyun‐Jin , Kim Dong‐Ku , Park Jin‐Ki , Chang Won‐Kyong , Chung Hyung‐Min , Choi Sang‐Yun , Kim Jae‐Hwan 
Published: January 2007

AbstractOct4 encodes a transcription factor that is involved in the maintenance of self‐renewal in stem cells. Recently, the molecular mechanisms that regulate Oct4 expression have come under investigation. In this study, we demonstrate that the orphan nuclear receptor steroidogenic factor‐1 (SF‐1) behaves as a transcriptional activator of human Oct4 (hOct4) through direct interaction with a SF‐1 binding element in the hOct4 proximal promoter. We found that Oct4 and SF‐1 were co‐expressed in undifferentiated human embryonal carcinoma NCCIT cells and downregulated during retinoic acid‐mediated differentiation. We examined the functional role played by SF‐1 in regulation of hOct4 transcription using a luciferase reporter assay and Western blot analysis. Overexpression of SF‐1 increased up to about threefold hOct4 promoter activity and endogenous hOct4 protein expression. Sequence analysis of the hOct4 promoter revealed that the transcriptional activity was closely linked to Conserved Regions 1 (CR1) and 2 (CR2), which contain three putative SF‐1‐binding sites (1st, 2nd, and 3rd SF‐1). Binding assays and mutagenesis of binding sites indicated that the 1st and 2nd SF‐1 elements (in CR1 and CR2, respectively) might be important cis‐regulatory elements in hOct4 promoter activity. However, differences in response to SF‐1 overexpression between wild‐type and mutant hOct4 promoters revealed that the 1st SF‐1 element is the key binding site for SF‐1‐mediated transcriptional activation. Thus, our data indicate that SF‐1 plays a crucial role in the regulation of hOct4 transcription through direct binding to the 1st SF‐1 in CR1 of the hOct4 proximal promoter. J. Cell. Biochem. 101:1198–1209, 2007. © 2007 Wiley‐Liss, Inc.
Calculations of frequency‐dependent molecular magnetizabilities with quasi‐relativistic time‐dependent generalized unrestricted Hartree–Fock method
Authors: Yoshizawa Terutaka , Hada Masahiko 
Published: January 2007

AbstractThe time‐dependent generalized unrestricted Hartree–Fock (TDGUHF) method combined with a two‐component quasi‐relativistic Hamiltonian generated from the Douglas–Kroll–Hess (DKH) transformation was developed to calculate frequency‐dependent molecular magnetizabilities, which are the linear response quantity of a molecule to an external magnetic field. By calculating the magnetizabilities of H2X (X = O, S, Se, and Te), the noble gases (He, Ne, Ar, Kr, and Xe) and small open shell molecules (CH2, CH3, and O2), we found that scalar relativistic terms affect mainly the diamagnetic magnetizability and spin‐orbit (SO) interaction affects the paramagnetic magnetizability. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 740–747, 2007
Protein kinase D2 potentiates MEK/ERK/RSK signaling, c‐Fos accumulation and DNA synthesis induced by bombesin in Swiss 3T3 cells
Authors: Sinnett‐Smith James , Zhukova Elena , Rey Osvaldo , Rozengurt Enrique 
Published: January 2007

AbstractProtein kinase D (PKD) plays an important role in mediating cellular DNA synthesis in response to G protein‐coupled receptor (GPCR) agonists but the function of other isoforms of the PKD family has been much less explored. Here, we examined whether PKD2 overexpression in Swiss 3T3 cells facilitates DNA synthesis and the activation of the extracellular regulated protein kinase (ERK) pathway in response to the mitogenic GPCR agonist bombesin. We show that PKD2 overexpression markedly potentiated the ability of this agonist to induce DNA synthesis. Addition of bombesin to Swiss 3T3 cells overexpressing PKD2 also induced a striking increase in the duration of MEK/ERK/RSK activation as compared with cultures of control cells. In contrast, neither DNA synthesis nor the duration of ERK activation in response to epidermal growth factor, which acts via protein kinase C/PKD2‐independent pathways, was increased. Furthermore, bombesin promoted a striking accumulation of c‐Fos protein in cells overexpressing PKD2. Our study demonstrates that PKD2, like PKD, facilitates mitogenesis and supports the hypothesis that an increase in the duration of the ERK signaling leading to accumulation of immediate gene products is one of the mechanisms by which isoforms of the PKD family enhance re‐initiation of DNA synthesis by Gq‐coupled receptor activation. J. Cell. Physiol. 211: 781–790, 2007. © 2007 Wiley‐Liss, Inc.
Expression of Gadd45a and p53 proteins in human pancreatic cancer: Potential effects on clinical outcomes
Authors: Dong Ming , Dong Qi , Zhang Hao , Zhou Jianping , Tian Yulin , Dong Yuting 
Published: January 2007

AbstractBackground and Objectivesp53 gene has a dual role as a trigger of apoptosis and as an initiator of DNA repair. Gadd45a gene assumes the function to maintain the stability of genome. The present study was designed to assess the significance of Gadd45a and p53 protein expression on pancreatic cancer.MethodsThe expression of p53 and Gadd45a was immunohistochemically studied in 59 patients with pancreatic cancer.ResultsThe positive expression rate of p53 and Gadd45a was 67.8% and 42.4%, respectively. p53 expression in the patients <65 years was significantly higher than that in the patients ≥65 years (P = 0.030). Gadd 45a expression showed no correlation to the patients' age. There was no relation for p53 expression to differentiation and TNM stages. Gadd 45a expression showed significant difference in histological differentiation (P = 0.007). The median survival time of p53(+) and Gadd45a(+) group was shorter than that of p53(−) and Gadd45a(−) group (P > 0.05), respectively. Meanwhile, the median survival time of p53 (+)Gadd45a(+) group was also shorter than that of p53(−)Gadd45a(−) group (P > 0.05).Conclusionsp53 and Gadd45a proteins are both highly expressed in pancreatic cancer. The overexpression of p53 and Gadd45a may have connection with the malignant biologic behavior of pancreatic cancer. J. Surg. Oncol.. © 2007 Wiley‐Liss, Inc.
Anti‐friction, anti‐wear and load‐carrying characteristics of environment friendly additive formulation
Authors: Anand O. N. , Kumar Vijay , Singh A. K. , Bisht R. P. S. 
Published: January 2007

AbstractThe extreme pressure (EP), anti‐wear and friction‐reducing characteristics of some of the commercial additive formulation and individual components on which these formulations are based have been studied and compared to characteristics of the components synthesised from naturally available non‐traditional vegetable oils and cashew nut shell liquid that have been refined and partially hydrogenated to improve stability. It has been shown that individual components from sulphurised and phosphosulphurised vegetable oils, esters and hydrogenated cardanol (derived from cashews) have better anti‐wear and friction‐reducing characteristics than the sulphurised olefins and alkylaryl phosphorothioates normally used as EP and anti‐wear additives, while the load‐carrying characteristics of a number of the combination of these derivatives are comparable. It has been shown that all these formulations are rapidly biodegradable and non‐toxic in nature as compared to traditional EP, anti‐wear and friction‐reducing additives, which fill in the category of slightly toxic to harmful.It is possible to formulate energy‐efficient EP gear oils that are fully biodegradable and non‐toxic by a combination of vegetable oil‐based additives of sulphurised vegetable oils, phosphosulphurised methyl recinoleate and phosphosulphurised hydrogenated cardanol amine borate, which meet all the performance characteristics of US steel 224 eg 52100, M‐50 AISI 1010 requirements. Copyright © 2007 John Wiley & Sons, Ltd.
Copolymers of 3,4‐Ethylenedioxythiophene and 3‐Methylthiophene: Properties, Applications and Morphologies
Authors: Ocampo Cintia , Armelin Elaine , Estrany Francesc , del Valle Luis J. , Oliver Ramón , Sepulcre Francesc , Alemán Carlos 
Published: January 2007

AbstractCopolymers of 3,4‐ethylenedioxythiophene and 3‐methylthiophene have been prepared by recurrent potential pulses using monomer mixtures with various concentration ratios, their properties being compared with those of the corresponding homopolymers. In addition, different technological applications have been tested for the generated copolymers. Results indicate that the properties of the copolymers are closer to those of poly(3,4‐ethylenedioxythiophene) than to those poly(3‐methylthiophene). Furthermore, the ability of the copolymers to store charge and to interact with plasmid DNA suggest that they are very promising materials.magnified image
Preparation of the Ultra‐Low Dielectric Constant Polyimide Fiber Membranes Enabled by Electrospinning
Authors: Liu Jieyu , Min Yong , Chen Jingyu , Zhou Hongwei , Wang Ce 
Published: January 2007

AbstractIn this article, electrospinning technique has been demonstrated for the synthesis of ultra‐low dielectric constant polyimide fiber membranes. Poly(amic acid) fiber membranes have been prepared as precursor. After the treatment of thermal imidization, ultra‐low dielectric constant polyimide fibers membranes can be obtained. The morphologies and structures of precursors and products are characterized by scanning electron microscopy (SEM), Fourier transmission infrared (FTIR) spectra, and a radio frequency (RF) impedance/capacitance material analyzer. The DK of the as‐prepared polyimide membrane ranges from 1.53 to 1.56, which could be applied in the electronic packaging industry.magnified image
Chemical and microphysical characterization of ambient aerosols with the aerodyne aerosol mass spectrometer
Authors: Canagaratna M.R. , Jayne J.T. , Jimenez J.L. , Allan J.D. , Alfarra M.R. , Zhang Q. , Onasch T.B. , Drewnick F. , Coe H. , Middlebrook A. , Delia A. , Williams L.R. , Trimborn A.M. , Northway M.J. , DeCarlo P.F. , Kolb C.E. , Davidovits P. , Worsnop D.R. 
Published: January 2007

AbstractThe application of mass spectrometric techniques to the real‐time measurement and characterization of aerosols represents a significant advance in the field of atmospheric science. This review focuses on the aerosol mass spectrometer (AMS), an instrument designed and developed at Aerodyne Research, Inc. (ARI) that is the most widely used thermal vaporization AMS. The AMS uses aerodynamic lens inlet technology together with thermal vaporization and electron‐impact mass spectrometry to measure the real‐time non‐refractory (NR) chemical speciation and mass loading as a function of particle size of fine aerosol particles with aerodynamic diameters between ∼50 and 1,000 nm. The original AMS utilizes a quadrupole mass spectrometer (Q) with electron impact (EI) ionization and produces ensemble average data of particle properties. Later versions employ time‐of‐flight (ToF) mass spectrometers and can produce full mass spectral data for single particles. This manuscript presents a detailed discussion of the strengths and limitations of the AMS measurement approach and reviews how the measurements are used to characterize particle properties. Results from selected laboratory experiments and field measurement campaigns are also presented to highlight the different applications of this instrument. Recent instrumental developments, such as the incorporation of softer ionization techniques (vacuum ultraviolet (VUV) photo‐ionization, Li+ ion, and electron attachment) and high‐resolution ToF mass spectrometers, that yield more detailed information about the organic aerosol component are also described. © 2007 Wiley Periodicals, Inc., Mass Spec Rev 26:185–222, 2007
Tensile Testing of Single Regenerated Cellulose Fibres
Authors: Adusumalli Ramesh‐Babu , Müller Ulrich , Weber Hedda , Roeder Thomas , Sixta Herbert , Gindl Wolfgang 
Published: January 2007

AbstractSummary: A tensile testing set‐up was developed for the determination of the elastic modulus, tensile strength, and failure strain of single regenerated cellulose fibres. Since the accuracy of strain measurement is crucial for the measured elastic modulus and failure strain, strain measurements were performed mechanically and with a non‐contacting optical method in parallel. The optical validation of mechanical strain measurement showed an agreement of measured strain >99%, confirming the accuracy and usefulness of the set‐up and sample geometry developed for the test series.
Cellulose‐Nanocomposites: Towards High Performance Composite Materials
Authors: Kohler Robert , Nebel Kai 
Published: January 2007

AbstractSummary: Strong cellulose fibres, e.g. flax and hemp, are increasingly used for composites. Despite substantial advantages, the tensile strength of these fibres is limited due to their complex structure and the unavoidable imperfections of the cell wall, inherent from growth or induced by processing. Essential improvements are possible by using highly crystalline cellulose fibrils (“whiskers”) which can be isolated from the cell wall, thus eliminating the influence of adhesion and defects. Instead of complete fibrillation, which demands special time consuming processing, a partly fibrillation has been achieved by adapted textile finishing procedures which have the potential for mass production. By combining chemical and mechanical/hydro‐mechanical treatments it is possible to produce finest fibrils with diameters from below 1 µm down to the nanometer range. The problem of fibril agglomeration during drying has been avoided by forming homogenous fibrous sheets in a wet‐laid non‐woven process. These sheets can be impregnated with thermosetting resins. Alternatively thermoplastic polymers can be directly integrated to form hybrid materials ready for moulding. The resulting composites show greatly enhanced mechanical properties.
Functional and Comfort Properties of Textiles from TENCEL® Fibres Resulting from the Fibres' Water‐Absorbing Nanostructure: A Review
Authors: Schuster K. Christian , Suchomel Friedrich , Männer Johann , Abu‐Rous Mohammad , Firgo Heinrich 
Published: January 2007

AbstractSummary: The comfort in wear of textiles has been studied extensively on the level of textile construction. The influence of the fibre material is present in the experience of textile consumers, but objective assessment is rather difficult. Some recent works are reviewed here. TENCEL® is a man‐made cellulosic fibre of the generic fibre type lyocell. The background of the special comfort in wear of textiles made from TENCEL® fibres is explained as a consequence of the fibres' water‐absorbing nanostructure. The basis for these properties are found in the high absorption of water and water vapour, which leads to high heat capacity and heat balancing effect for thermoregulation, comparable with the action of phase change materials. The thermal wear properties resulting are the cool and dry touch, the active cooling effect in sports wear, and the warming properties when used as an insulation layer. These effects are to a certain extent adaptive to the environment, providing comfort in a wide range of climatic conditions. Moreover, neutral electric properties, retarded bacterial growth and good skin sensory perception add to the overall skin friendly properties, which were also shown in wear studies with patients suffering from skin diseases.
Synthesis and Properties of Novel Hydrogels from Cross‐linked Starch Phosphates
Authors: Passauer Lars , Liebner Falk , Fischer Klaus 
Published: January 2007

AbstractSummary: Starch based stable hydrogels providing high swelling and water storing capacity are not only of certain interest for the cosmetics and hygiene industry but also have the potential to become an effective tool in combating desertification and supporting cultivation in many regions of the world. It has been found that strong water adsorbing covalent networks with free swelling capacity (FSC) of up to 190 g water/g hydrogel can be obtained by cross‐linking low‐substituted mono‐starch phosphates (MSP) in a semi‐dry process with di‐ and tricarboxylic acids such as succinic acid (SA), adipic acid (AA) or citric acid (CA). The linear behaviour over a wide frequency range of the rheological parameters G′ and G″ which were determined by using a shearing disc viscosimeter clearly reveal that the cross‐linked starch phosphates are stable hydrogels having stronger elastic than viscous properties.
Determination of the Mode of Free Radical Termination from Pulsed Laser Polymerization Experiments
Authors: Nikitin Anatoly N. , Hutchinson Robin A. 
Published: January 2007

AbstractThe molecular‐weight distribution (MWD), obtained by pulsed laser polymerization (PLP) at the high termination rate limit has been considered for investigating termination kinetics. The proposed methodology takes into account both the composite model for termination and the chain‐length dependencies of propagation for short‐chain and long‐chain radicals. Power‐law expressions are used to represent propagation $[k_{\rm p}^L = k_{\rm p}^0 (L)^{ - \alpha } ]$ and termination $[k_{\rm t}^{L,L} = k_{\rm t}^0 (L)^{ - \beta } ]$ of long‐chain radicals (where k and k represent the maximum “virtual” rate coefficients for monomeric radicals, and α and β capture the chain‐length dependencies for propagation and termination), with the combined value of (β − α) evaluated from the MWD, after correcting for the influence of the kinetics of short‐chain radicals. A novel method is also developed for determining the mode of termination, δ, from MWDs produced by PLP at the high termination rate limit. Simulations for methyl methacrylate (MMA) polymerization at 25 °C confirm that the method can be applied robustly in the presence of complicating factors such as chain transfer to monomer and SEC broadening. The analysis of an experimental MWD obtained for MMA polymerization at 25 °C results in estimates of 0.14 ± 0.03 for (β − α) and 0.75 ± 0.04 for δ.magnified image
Impaired motor imagery in patients with essential tremor: A case control study
Authors: Lo Yew‐Long , Louis Elan D. , Fook‐Chong Stephanie , Tan Eng‐King 
Published: January 2007

AbstractMotor imagery (MI), which refers to the process of mental representation of movements, has not been studied in patients with essential tremor (ET). We investigated the presence of impaired MI in ET patients compared with healthy controls. A group of drug‐naive and nondemented ET patients and age‐matched controls were studied using transcranial magnetic stimulation, while they were specifically instructed to try and imagine themselves performing two motor tasks. The various clinical and electrophysiological variables were evaluated and compared. Repeated measures ANOVA demonstrated a significant difference between ET patients and controls with respect to mean motor‐evoked potential (MEP) amplitudes (F(1,38) = 31.92, P < 0.005) during MI. The process of MI effectively facilitated MEP amplitude in controls but not in ET patients, regardless of side of stimulation or motor tasks. We provide evidence to demonstrate impairment of MI in a group of ET patients compared with healthy controls. The basis for this novel finding is unclear, and further studies are warranted to determine whether it is related to cerebellar or motor cortical dysfunction. © 2007 Movement Disorder Society
An Adaptive Finite Element Approach for Brittle Fracture
Authors: Geißler Gordon , Kaliske Michael 
Published: January 2007

AbstractThe extension of the finite element method to take discrete fracture and failure modes into account is a current field of research. In recent times, first results in terms of cohesive element formulations have been introduced into commercial applications. Such element formulations are able to cover the discrete behaviour of interfaces between different materials or the mechanical processes of thin layers. These approaches are not suitable for simulations with unknown crack paths in homogeneous materials, due to the initial elastic phase of the material formulation and the necessity to define potential crack paths a priori. The presented strategy starts with an unextended model and modifies the structure during the computations in terms of an adaptive procedure. The idea is to generate additional elements, based on the cohesive element formulation, to approximate arbitrary crack paths. For this purpose, a failure criterion is introduced. For nodes where the limiting value is reached, cohesive elements are introduced between the volume element boundaries of accordingly facets and corresponding nodes are duplicated. Necessary modifications for this application on system level as well as the element and the material formulation are introduced. By means of some numerical examples, the functionality of the presented procedure is demonstrated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of configurational forces in the context of a kinked crack
Authors: Horst Thomas , Lauke Bernd , Heinrich Gert 
Published: January 2007

AbstractThe application of the configurational force approach in crack problems is often used in order to establish fracture criteria that are adapted to a specific material behaviour. The tangential component of the calculated vectorial quantity that acts at the crack tip is a generalisation of the conventional J‐integral and can be interpreted as the energy release rate when the crack extends in this direction. However, the interpretation of nontangential components in the same way, and hence the interpretation of this vectorial quantity as the crack driving force, is not consistent with established kink criteria in the special case of linear elastic fracture mechanics.As a classical example, an in‐plane loaded crack in a homogeneous isotropic linear elastic material is considered under the small strain assumption. Using the expansion of stress intensity factors at the extended crack tip, nontangential components of the configurational force can be interpreted as sensitivities to crack deflection. This perspective has the potential of generalisation which can be applied to more complex situations in order to study the interplay between mechanical fields in the vicinity of the crack tip and the microstructural influence within the process zone. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)