bluuebunny/crossref_metadata_2025_split huggingface dataset:
FoxO3a preferentially induces p27Kip1 expression while impairing muscle precursor cell‐cycle progression
Authors: Rathbone Christopher R. , Booth Frank W. , Lees Simon J. 
Published: September 2007

AbstractPrevious work has demonstrated that forkhead transcription factors, which include the FoxO subfamily, play a critical role in muscle atrophy by inducing expression of the atrophy‐related ubiquitin ligases. The proliferation of muscle precursor cells (MPC) is also essential for skeletal muscle mass. The hypothesis was tested that the FoxO forkhead transcription factor FoxO3a hinders MPC proliferation. The present studies were designed to determine the effects of overexpression of FoxO3a on in vitro proliferation of MPCs. MPCs infected with an adenovirus for wild‐type FoxO3a had decreased DNA synthesis as detected by the incorporation of 5‐bromo‐2′ deoxyuridine. In general, cyclin‐dependent kinase inhibitors, including p27Kip1and p21Waf/Cip1, inhibit cell proliferation. Associated with the impaired MPC proliferation, we found an increase in the promoter activity and protein levels of the cyclin‐dependent kinase inhibitor p27Kip1, whereas there was no effect and a decrease in the promoter activity and protein levels of p21Waf/Cip1. FoxO3a overexpression had no effect on either the phosphorylation of retinoblastoma protein (ser780) or cyclin D1 protein levels, suggesting that FoxO3a does not effect the early phase of the G1–S transition. In addition to its ability to induce muscle atrophy, these studies identify FoxO3a as a negative regulator of MPC proliferation. Our findings suggest that attenuating increased FoxO3a may restore MPC proliferation to prevent atrophy and improve the regenerative capacity of skeletal muscle. Muscle Nerve, 2007
Intrathecal baclofen for spasticity‐related pain in amyotrophic lateral sclerosis: Efficacy and factors associated with pain relief
Authors: McClelland Shearwood , Bethoux Francois A. , Boulis Nicholas M. , Sutliff Matthew H. , Stough Darlene K. , Schwetz Kathleen M. , Gogol Danuta M. , Harrison Michelle , Pioro Erik P. 
Published: September 2007

AbstractClinical signs and symptoms of spasticity include hypertonia, involuntary movements (spasms, clonus), decreased range of motion, contractures, and often spasm‐related pain. When spasticity is refractory to medical management, patients may be referred for intrathecal baclofen (ITB) pump placement. We reviewed a cohort of amyotrophic lateral sclerosis (ALS) patients with intractable spasticity requiring ITB to further define the impact of ITB on pain relief in this patient population. From 2003 to 2005, eight patients (mean age 43.8 years; 5 men, 3 women) with ALS received ITB for pain associated with intractable spasticity at our institution. Mean disease duration preoperatively was 47.4 months, mean follow‐up was 9.8 months, and pain was evaluated using a 0–10 scoring system. All patients experienced spasticity relief in response to a preoperative bolus test injection of ITB (25–50 μg) via lumbar puncture. Following ITB pump placement, the average reduction of pain was 54% (P = 0.0082). Six patients (75%) experienced pain score reduction, three of whom had complete pain relief. Postoperative pain reduction was predicted by the degree of pain reduction following preoperative ITB test injection. These results support ITB as a treatment modality for pain associated with spasticity in ALS. Muscle Nerve, 2007
Development and validation of the pelvic floor inventories Leiden (PelFIs)
Authors: Zalm Petra J. Voorham‐van der , Stiggelbout Anne M. , Aardoom Ilona , Deckers Stella , Greve Inge G. , Nijeholt Guus A.B. Lycklama à , Pelger Rob C.M. 
Published: September 2007

AbstractAimsTo evaluate the validity and reliability in Dutch of the Pelvic Floor Inventories Leiden (PelFIs) for men and women, an administered questionnaire, developed to create a condition‐specific pelvic floor questionnaire addressing all symptoms of micturition, defecation and sexual dysfunction related to pelvic floor dysfunction.MethodsThe PelFIs is an 83‐item instrument for women and 76‐item instrument for men measuring the degree of pelvic floor dysfunction, containing nine different domains. Questions have been selected which, from a clinical point of view, should configure a domain. The PelFIs was administered to healthy volunteers (N = 120), and to patients (N = 100). Reliability of the PelFIs was assessed by internal consistency and test‐retest reliability. Construct validity was established comparing healthy volunteers and patients by intercorrelating the domains.ResultsA total of 220 questionnaires were completed; by 147 women and 73 men. Some domains in the men's questionnaire had a low alpha (α) although the overall α was good. The overall of the domains for men ranged from 0.53 to 0.90. The internal consistency for the total scale of men's questionnaire was 0.84. The overall of the domains in women ranged from 0.60 to 0.85. The internal consistency of the women's questionnaire was 0.88 for the total scale. Intraclass correlation ranged from 0.65 to 0.88. Differences between healthy volunteers and patients were statistically significant for all domains.ConclusionThe PelFIs is a new, practical and conceptually clear questionnaire, which focus on micturition, defecation and/or sexual dysfunction related to pelvic floor dysfunction. Neurourol. Urodynam. 27:301–305, 2008. © 2007 Wiley‐Liss, Inc.
Spiral artery blood volume in normal pregnancies and those compromised by pre‐eclampsia
Authors: Moore Rachel J. , Ong Stephen S. , Tyler Damian J. , Duckett Rachel , Baker Philip N. , Dunn William R. , Johnson Ian R. , Gowland Penny A. 
Published: September 2007

AbstractThe aim of this work was to use intravoxel incoherent motion (IVIM) to provide a non‐invasive in vivo assessment of the function of the maternal spiral arteries that feed the placenta in normal pregnancy and in pre‐eclampsia. Eleven normal pregnant women were scanned at 16, 22, 29 and 35 weeks gestation in a longitudinal study. Nine normal pregnant women and six women with pre‐eclampsia were scanned in a cross‐sectional study, within 10 days of delivery. The MRI IVIM technique was used to measure the moving blood fraction (f%) at the basal plate. There was no evidence that f% changed with gestational age (P = 0.84), but considering the cross‐sectional groups, f% in women with pre‐eclampsia was reduced compared with normal pregnancy (mean ± SD: 36 ± 5% and 27 ± 5%; P < 0.005). In conclusion, pregnancies complicated by pre‐eclampsia exhibit a reduced fraction of moving blood within the region of the spiral arteries. IVIM performed in the mid‐trimester may provide an early means of predicting those pregnancies with an increased likelihood of being complicated by pre‐eclampsia. Copyright © 2007 John Wiley & Sons, Ltd.
On the modelling of incompressibility in linear and non‐linear elasticity with the master–slave approach
Authors: Muñoz J. J. 
Published: September 2007

AbstractThe master–slave approach is adapted to model the kinematic constraints encountered in incompressibility. The method presented here allows us to obtain discrete displacement and pressure fields for arbitrary finite element formulations that have discontinuous pressure interpolations. The resulting displacements satisfy exactly the incompressibility constraints in a weak sense, and are obtained by solving a system of equations with the minimum (independent) degrees of freedom. In linear analysis, the method reproduces the well‐known stability results for inf–sup compliant elements, and permits to compute the pressure modes (physical or spurious) when they exist. By rewriting the equilibrium equations of a hyperelastic material, the method is extended to non‐linear elasticity, while retaining the exact fulfilment of the incompressibility constraints in a weak sense. Problems with analytical solution in two and three dimensions are tested and compared with other solution methods. Copyright © 2007 John Wiley & Sons, Ltd.
Discrete gradient method in solid mechanics
Authors: Lu Jia , Qian Jing , Han Weimin 
Published: September 2007

AbstractA discrete method to boundary value problems in solid mechanics is presented. In this method, the unknown variable and its derivative are defined only at nodes. A discrete gradient operator is constructed with the aid of a tensorial identity on the Voronoi diagram. This operator is utilized in a weak form to derive a discrete Galerkin formulation for the boundary value problem. The theoretical underpins of the methodology are discussed, and the details of computational implementation in two‐dimensional elasticity, both small strain and finite strain, are provided. Several benchmark tests are presented to demonstrate the accuracy, convergence, and other properties of the method. Copyright © 2007 John Wiley & Sons, Ltd.
Substituent effects on the formation of sulfonyl cations from sulfonyl chlorides: comparisons of solvolysis kinetic data with calculated gas phase energies
Authors: Bentley T. William , Jones Robert O. 
Published: September 2007

AbstractSuitable theoretical methods are validated for organosulfur compounds using experimental data for gas phase enthalpies of formation, proton affinities (PA) and heterolytic bond dissociation enthalpies (HBDEs). From enthalpies of chloride anion transfers from neutral chlorides to acyl, sulfonyl or cumyl cations in the gas phase, it is calculated that (i) similar aromatic substituent effects are expected for heterolyses of acyl, sulfonyl and cumyl chlorides; (ii) HBDEs for loss of chloride increase by over 70 kcal mol−1 from 4‐MeOC6H4COCl to SO2Cl2. Rate constants for solvolyses of 4‐Z‐substituted arenesulfonyl chlorides (Z = OMe, Me, H, Cl, NO2) in 97% w/w 2,2,2‐trifluoroethanol (TFE)–water are reported. Substituent effects are smaller than observed for identical solvolyses of acyl and cumyl chlorides, and are much smaller than those predicted theoretically for gas phase unimolecular heterolysis (explained by variable amounts of nucleophilic solvent assistance). Copyright © 2007 John Wiley & Sons, Ltd.
Transport Phenomena in an Atmospheric‐Pressure Townsend Discharge Fed by N2/N2O/HMDSO Mixtures
Authors: Enache Ionut , Caquineau Hubert , Gherardi Nicolas , Paulmier Thierry , Maechler Louison , Massines Francoise 
Published: September 2007

AbstractThis paper focuses on the understanding of the main mechanisms that participate in the growth process of an SiO2‐like film in an atmospheric pressure Townsend discharge in N2 with small ad‐mixtures of HMDSO and N2O. The approach consists of analyzing the influence of operating parameters on the growth rate profile through a fluid dynamics model. The suggested chemical mechanism is constituted by one volume reaction and one surface reaction. This simple model enables us to assume which phenomena control the film growth process among the following mechanisms: HMDSO dissociation by N2(A3Σ) in Si‐containing radicals, radicals transport to the surface, and surface activation process by plasma.magnified image
Nitrogen‐Rich Plasma‐Polymer Films for Biomedical Applications
Authors: Truica‐Marasescu Florina , Wertheimer Michael R. 
Published: September 2007

AbstractLow‐pressure plasma co‐polymerisation of binary gas mixtures of ethylene and ammonia was investigated in order to deposit N‐rich plasma polymer coatings for biomedical applications. Deposition kinetics and relevant surface characteristics were investigated as a function of r.f. power, gas pressure, and NH3/C2H4 ratio. Physico‐chemical properties of the coatings were determined by surface‐sensitive techniques: for example, total nitrogen concentrations up to 40 at.‐% were measured by XPS, while those of primary amines were determined by chemical derivatisation followed by XPS analysis. L‐PPE:N films were further characterised by UV‐vis and IR spectroscopic ellipsometry and by CAG.magnified image
Efficient comprehensive scoring of docked protein complexes using probabilistic support vector machines
Authors: Martin Oliver , Schomburg Dietmar 
Published: September 2007

AbstractBiological systems and processes rely on a complex network of molecular interactions. While the association of biological macromolecules is a fundamental biochemical phenomenon crucial for the understanding of complex living systems, protein‐protein docking methods aim for the computational prediction of protein complexes from individual subunits. Docking algorithms generally produce large numbers of putative protein complexes with only few of these conformations resembling the native complex structure within an acceptable degree of structural similarity. A major challenge in the field of docking is to extract near‐native structure(s) out of the large pool of solutions, the so called scoring or ranking problem. A series of structural, chemical, biological and physical properties are used in this work to classify docked protein‐protein complexes. These properties include specialized energy functions, evolutionary relationship, class specific residue interface propensities, gap volume, buried surface area, empiric pair potentials on residue and atom level as well as measures for the tightness of fit. Efficient comprehensive scoring functions have been developed using probabilistic Support Vector Machines in combination with this array of properties on the largest currently available protein‐protein docking benchmark. The established classifiers are shown to be specific for certain types of protein‐protein complexes and are able to detect near‐native complex conformations from large sets of decoys with high sensitivity. Using classification probabilities the ranking of near‐native structures was drastically improved, leading to a significant enrichment of near‐native complex conformations within the top ranks. It could be shown that the developed schemes outperform five other previously published scoring functions. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Crystal structures of Salmonella typhimurium propionate kinase and its complex with Ap4A: Evidence for a novel Ap4A synthetic activity
Authors: Simanshu Dhirendra K. , Savithri H. S. , Murthy M. R. N. 
Published: September 2007

AbstractPropionate kinase catalyses the last step in the anaerobic breakdown of L‐threonine to propionate in which propionyl phosphate and ADP are converted to propionate and ATP. Here we report the structures of propionate kinase (TdcD) in the native form as well as in complex with diadenosine 5′,5′′′‐P1,P4‐tetraphosphate (Ap4A) by X‐ray crystallography. Structure of TdcD obtained after cocrystallization with ATP showed Ap4A bound to the active site pocket suggesting the presence of Ap4A synthetic activity in TdcD. Binding of Ap4A to the enzyme was confirmed by the structure determination of a TdcD‐Ap4A complex obtained after cocrystallization of TdcD with commercially available Ap4A. Mass spectroscopic studies provided further evidence for the formation of Ap4A by propionate kinase in the presence of ATP. In the TdcD‐Ap4A complex structure, Ap4A is present in an extended conformation with one adenosine moiety present in the nucleotide binding site and other in the proposed propionate binding site. These observations tend to support direct in‐line transfer of phosphoryl group during the kinase reaction. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Evaluating protein:protein complex formation using synchrotron radiation circular dichroism spectroscopy
Authors: Cowieson Nathan P. , Miles Andrew J. , Robin Gautier , Forwood Jade K. , Kobe Bostjan , Martin Jennifer L. , Wallace B. A. 
Published: September 2007

AbstractCircular dichroism (CD) spectroscopy beamlines at synchrotrons produce dramatically higher light flux than conventional CD instruments. This property of synchrotron radiation circular dichroism (SRCD) results in improved signal‐to‐noise ratios and allows data collection to lower wavelengths, characteristics that have led to the development of novel SRCD applications. Here we describe the use of SRCD to study protein complex formation, specifically evaluating the complex formed between carboxypeptidase A and its protein inhibitor latexin. Crystal structure analyses of this complex and the individual proteins reveal only minor changes in secondary structure of either protein upon complex formation (i.e., it involves only rigid body interactions). Conventional CD spectroscopy reports on changes in secondary structure and would therefore not be expected to be sensitive to such interactions. However, in this study we have shown that SRCD can identify differences in the vacuum ultraviolet CD spectra that are significant and attributable to complex formation. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Mechanistic insights into the inhibition of prostate specific antigen by β‐lactam class compounds
Authors: Singh Pratap , Williams Simon A. , Shah Meha H. , Lectka Thomas , Pritchard Gareth J. , Isaacs John T. , Denmeade Samuel R. 
Published: September 2007

AbstractProstate Specific Antigen (PSA) is a biomarker used in the diagnosis of prostate cancer and to monitor therapeutic response. However, its precise role in prostate carcinogenesis and metastasis remains largely unknown. A number of studies arguing in the favor of an active role of PSA in prostate cancer development and progression have implicated this serine protease in the release and activation of growth factors such as insulin‐like growth factor 1 (IGF1) through cleavage of insulin like growth factor binding protein 3 and Transforming Growth Factor β (TGF‐β) through cleavage of Latent TGF‐β. In contrast, other studies suggest that PSA activity might hinder tumor development and progression. In light of these contradictory findings, efficient inhibitors of PSA are needed for exploring its biological role in tumor development and metastasis. Towards the goal of developing potent inhibitors of PSA, we have explored the molecular mechanism of a series of β‐lactam based compounds on binding to PSA using activity assays, matrix assisted laser desorption ionization with a time‐of‐flight mass spectrometry, and GOLD docking methodology. The mass spectrometry experiments and the activity assays confirmed the time‐dependent and covalent nature of β‐lactam binding. To gain insights on the reaction intermediates at the molecular level, we docked β‐lactam inhibitors to a homology modeled PSA using the GOLD docking program in noncovalent and covalent binding modes. The docking studies elucidated the molecular details of the early noncovalent Michaelis complex, the acyl‐enzyme covalent complex, and the nature of conformational reorganization required for the long term stability of the covalent complex. Additionally, the molecular basis for the effect of stereochemistry of the lactam ring on the inhibitory potency was elucidated through docking of β‐lactam enantiomers. As a validation of our docking methodology, two novel enantiomers were synthesized and evaluated for their inhibitory potency using fluorogenic substrate based activity assays. Additionally, cis enantiomers of eight β‐lactam compounds reported in a previous study were docked and their GOLD scores and binding modes were analyzed in order to assess the general applicability of our docking results. The close agreement of our docking results with the experimental data validates the mechanistic insights revealed through the docking studies and paves the way for the design and development of potent and specific inhibitors of PSA. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Characterization and structural modeling of a novel thermostable glycine oxidase from Geobacillus kaustophilus HTA426
Authors: Martínez‐Martínez Irene , Navarro‐Fernández José , García‐Carmona Francisco , Takami Hideto , Sánchez‐Ferrer Álvaro 
Published: September 2007

AbstractGlycine oxidase from Geobacillus kaustophilus HTA426 (GOXK) is a 43 kDa monomer flavoenzyme containing noncovalently bound FAD. The induction of the enzyme resulted in the expression of a fully soluble protein with higher specific activity than those previously reported for GOX from B. subtilis (GOXB). A study of the kinetic properties of this novel GOXK revealed the lowest KM values for most of the substrates analyzed, with the exception of D‐proline which kept a similar value and had the highest Vmax value reported. The Vmax/KM ratio maintained a substrate preference of GOXK for amines of small size, like glycine, sarcosine, N‐ethyl‐glycine, and glycine‐ethyl‐ester. GOXK presented good stability at 60–70°C and in alkaline media (pH 6–9.5). The putative tridimensional structure was modeled by sequence alignment and by comparing the changes between GOXK and GOXB, and the residues that could be responsible for the substrate specificity as well as those essential for the catalytic activity were found. The comparison between the possible topology of GOXK with that of GOXB showed changes at the putative interactions between monomers for the building of the tetrameric oligomerization. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Reliability as an added‐value factor in an automotive clutch system
Authors: Teixeira Carlos Adriano Rigo , Cavalca Kátia Lucchesi 
Published: September 2007

AbstractIn the present competitive scenario, companies face the challenge of developing new products in a short time period, with superior technology in relation to prior developments and reduced costs to guarantee the survival of their business. Success is directly coupled with client requirements where quality and reliability should be the highest feasible, whereas deadlines and price have to be the lowest possible. This paper discusses tools and methods applied to planning and assurance of quality, which have to be taken into account at the product conception project, which concerns the phase in which quality, reliability and the final price of a product are technically defined. A methodology is presented for this purpose, and it can be extended to any product or system with few adaptations concerning quality, reliability and cost models. The product selected for the case‐study analysis in this work is an automotive clutch. The methodology proposed for the analysis is a combination of the KANO method, target cost and value analysis with respect to the assessment of client requirement compliance levels and the determination of the choice of functions—whose relative costs are above relative needs, therefore offering optimization or elimination potential. Thus, the reliability concepts of statistical distributions and fault tree analysis are employed to locate critical components and quantify design temporary performance. To provide life tests results to the highest failure risk in the system, the planning and deployment of accelerated tests are carried out. The final goal of this paper is the reliability assessment based on critical levels for the analysis of components to be improved or optimized and, mainly, to create a methodology for the development of optimized products. Copyright © 2007 John Wiley & Sons, Ltd.