bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bromelain inhibits nuclear factor kappa‐B translocation, driving human epidermoid carcinoma A431 and melanoma A375 cells through G2/M arrest to apoptosis
Authors: Bhui Kulpreet , Tyagi Shilpa , Srivastava Amit Kumar , Singh Madhulika , Roy Preeti , Singh Richa , Shukla Yogeshwer 
Published: March 2011

AbstractBromelain, obtained from pineapple, is already in use clinically as adjunct in chemotherapy. Our objective was to test its ability to act as a sole anti‐cancer agent. Therefore, we describe its anti‐proliferative, anti‐inflammatory and subsequent anti‐cancer effects in vitro, against human epidermoid carcinoma‐A431 and melanoma‐A375 cells. Bromelain exhibited reduction in proliferation of both these cell‐lines and suppressed their potential for anchorage‐independent growth. Further, suppression of inflammatory signaling by bromelain was evident by inhibition of Akt regulated‐nuclear factor‐kappaB activation via suppression of inhibitory‐kappaBα phosphorylation and concomitant reduction in cyclooxygenase‐2. Since, the inflammatory cascade is well‐known to be closely allied to cancer; we studied the effect of bromelain on events/molecules central to it. Bromelain caused depletion of intracellular glutathione and generation of reactive oxygen‐species followed by mitochondrial membrane depolarization. This led to bromelain‐induced cell‐cycle arrest at G2/M phase which was mediated by modulation of cyclin B1, phospho‐cdc25C, Plk1, phospho‐cdc2, and myt1. This was subsequently followed by induction of apoptosis, indicated by membrane‐blebbing, modulation of Bax‐Bcl‐2 ratio, Apaf‐1, caspase‐9, and caspase‐3; chromatin‐condensation, increase in caspase‐activity and DNA‐fragmentation. Bromelain afforded substantial anti‐cancer potential in these settings; hence we suggest it as a potential prospect for anti‐cancer agent besides only an additive in chemotherapy. © 2011 Wiley Periodicals, Inc.
Toward the Description and Prediction of Solvent Induced Variations in Methacrylate Propagation Rate Coefficients on the Basis of Solvatochromic Parameters
Authors: Jeličić Aleksandra , Yasin Muttaqin , Beuermann Sabine 
Published: March 2011

AbstractBenzyl methacrylate (BzMA) propagation rate coefficients, kp, were determined in ionic liquids and common organic solvents via pulsed‐laser polymerizations with subsequent polymer analysis by size‐exclusion chromatography (PLP‐SEC). The aim of the work is to gain a deeper understanding of the solvent influence on kp and to develop a general correlation between solvent‐induced variations in kp and solvent properties. Applying a linear solvation energy relationship (LSER), which correlates kp to solvent solvatochromic parameters, suggests that dipolarity/polarizability determines the solvent influence on kp. To compare the solvent influence on BzMA kp with data for methyl methacrylate, hydroxypropyl methacrylate, and 2‐ethoxyethyl methacrylate normalized kp data were treated by a single LSER, providing a universal treatment of the solvent influence on the propagation kinetics of the four monomers. Further, the predictive capabilities of this universal correlation were tested with additional monomers from the methacrylate family. magnified image
Real‐time optical motion correction for diffusion tensor imaging
Authors: Aksoy Murat , Forman Christoph , Straka Matus , Skare Stefan , Holdsworth Samantha , Hornegger Joachim , Bammer Roland 
Published: March 2011

AbstractHead motion is a fundamental problem in brain MRI. The problem is further compounded in diffusion tensor imaging because of long acquisition times, and the sensitivity of the tensor computation to even small misregistration. To combat motion artifacts in diffusion tensor imaging, a novel real‐time prospective motion correction method was introduced using an in‐bore monovision system. The system consists of a camera mounted on the head coil and a self‐encoded checkerboard marker that is attached to the patient's forehead. Our experiments showed that optical prospective motion correction is more effective at removing motion artifacts compared to image‐based retrospective motion correction. Statistical analysis revealed a significant improvement in similarity between diffusion data acquired at different time points when prospective correction was used compared to retrospective correction (P < 0.001). Magn Reson Med, 2010. © 2011 Wiley‐Liss, Inc.
Perfusion imaging with a freely diffusible hyperpolarized contrast agent
Authors: Grant Aaron K. , Vinogradov Elena , Wang Xiaoen , Lenkinski Robert E. , Alsop David C. 
Published: March 2011

AbstractContrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2‐methylpropan‐2‐ol (also known as dimethylethanol, tertiary butyl alcohol and tert‐butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady‐state free precession sequence following administration of hyperpolarized 2‐methylpropan‐2‐ol show that this agent can be imaged with 2–4s temporal resolution, 2 mm slice thickness, and 700 μm in‐plane resolution while retaining adequate signal‐to‐noise ratio. 13C relaxation measurements on 2‐methylpropan‐2‐ol in blood at 9.4T yield T1 = 46 ± 4s and T2 = 0.55 ± 0.03s. In the rat brain at 4.7T, analysis of the temporal dynamics of the balanced steady‐state free precession image intensity in tissue and venous blood indicate that 2‐methylpropan‐2‐ol has a T2 of roughly 2–4s and a T1 of 43 ± 24s. In addition, the images indicate that 2‐methylpropan‐2‐ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2‐methylpropan‐2‐ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Development of chemical exchange saturation transfer at 7T
Authors: Dula Adrienne N. , Asche Elizabeth M. , Landman Bennett A. , Welch E. Brian , Pawate Siddharama , Sriram Subramaniam , Gore John C. , Smith Seth A. 
Published: March 2011

AbstractChemical exchange saturation transfer (CEST) MRI is a molecular imaging method that has previously been successful at reporting variations in tissue protein and glycogen contents and pH. We have implemented amide proton transfer (APT), a specific form of chemical exchange saturation transfer imaging, at high field (7T) and used it to study healthy human subjects and patients with multiple sclerosis. The effects of static field inhomogeneities were mitigated using a water saturation shift referencing method to center each z‐spectrum on a voxel‐by‐voxel basis. Contrary to results obtained at lower fields, APT imaging at 7T revealed significant contrast between white and gray matters, with a higher APT signal apparent within the white matter. Preliminary studies of multiple sclerosis showed that the APT asymmetry varied with the type of lesion examined. An increase in APT asymmetry relative to healthy tissue was found in some lesions. These results indicate the potential utility of APT at high field as a noninvasive biomarker of white matter pathology, providing complementary information to other MRI methods in current clinical use. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Uniqueness and existence theorems of solutions of the boundary value problems of the theory of consolidation with double porosity
Authors: Bitsadze Lamara , Basheleishvili Mikheil 
Published: March 2011

AbstractIn this paper we consider the Aifantis' theory of consolidation with double porosity and we prove the uniqueness and existence theorems of solutions of basic boundary value problems (BVPs) of statics for the two‐dimensional finite and infinite domains. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Various Feedforward Schemes and a Passivity Based Backstepping Feedback Control of an Elastic Robot
Authors: Staufer Peter , Gattringer Hubert , Höbarth Wolfgang , Bremer Hartmut 
Published: March 2011

AbstractLightweight constructions in industry plants lead to elastic deflections causing vibrations and a loss in tracking precision. In order to keep the tracking error for these elastic multibody systems low, the proposed control strategies are combinations of feedforward and feedback schemes. In this work various implemented strategies for computing a feedforward control are proposed and compared, which can be calculated with some simplifications from the mathematical model of the elastic multibody system. Some of these are considering the elastic deflections. The stabilization of the error dynamics is achieved by a simple PD‐joint control or passivity based backstepping. In this algorithm the system is split into subsystems and for these subsystems simple control concepts can be applied. The feedback control law of the total system is obtained by means of backstepping theory, considering the internal energy flows in the system. Experimental results are presented to verify the control strategies. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mathematical Evaluation of EBSD Data
Authors: Melcher Andreas , Phan Van Tung , Schendel Simone , Böhlke Thomas 
Published: March 2011

AbstractIn this work, a short overview is given, how data resulting from Electron Backscatter Diffraction (EBSD) measurements can be used to obtain a discrete version of the Orientation Distribution Function (ODF). Discrete ODFs are necessary, e.g. for micromechanically based simulations of metal forming operations based on the finite element method. To use EBSD data for simulations several processing steps are necessary as conversion and segmentation of the EBSD measurement data [1], definition of a fundamental zone in Euler space and a procedure for the tesselation of this zone [2]. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computation of the Coupled Dynamics of Fibers in a Spray
Authors: Diffo Patrick , Wulf Peter , Breuer Michael 
Published: March 2011

AbstractThe PUR‐fiber‐spray molding technology is a manufacturing process which produces polyurethane‐based (PUR) composites by spraying the matrix together with reinforcing fibers in a tool form or on a substrate. Thereby chopped fibers are laterally (sidewise) injected in the polyurethane‐air spray cone for wetting before the entire composite is spread on the substrate, where it starts curing. To investigate and compute the fiber orientation and density distribution in the final composites manufactured by this process, a new approach simplifying the multiply coupled interaction of the three phases is presented in this paper. Hereby it is presumed that the final position and orientation of a fiber on a substrate results from its dynamics and coupled interactions with air, PUR‐droplets and other fibers within the spray cone. Thus, a model of the process is built, that computes the transient behavior of the air‐liquid droplets mixture by the CFD code ANSYS Fluent and its influence on the dynamics of the fibers by an extra code called FIDYST. For this multiphase problem two approaches are presented for the droplet‐fiber coupling using a concept called “homogenization” of the liquid phase (droplets in the continuous phase). (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MBS/FEM Co‐Simulation Approach for Lubrication Problems
Authors: Busch Martin , Schweizer Bernhard 
Published: March 2011

AbstractHydrodynamic bearings are used in many technical systems, e.g., in combustion engines, in gear boxes or in rotor systems. To model such bearings, different methods are available. Often, reduced bearing models are applied which can be incorporated into the multibody systems by analytical formulas or pre‐computed look‐up tables [1]. Such approaches are very time‐efficient but suffer from limited physical correctness. In order to improve the physical bearing model, the fluid flow and temperature field in the bearing gap have to be computed with partial differential equations which have to be solved simultaneously with the multibody system. These equations are nonlinear and have to be discretized with finite elements, for instance. In the current work, we consider a fully coupled simulation of a multibody rotor system with a finite element model for the hydrodynamic bearings. A co‐simulation interface between two commercial simulation tools is presented. For the synchronization of the solvers, three numerical coupling approaches (an explicit, an implicit and a semi‐implicit approach) are analyzed and compared. For the examined rotor/bearing system, it is shown that semi‐implicit coupling techniques may remarkably stabilize the solver coupling compared to well‐established explicit co‐simulation techniques [2]. Furthermore, a reduction method is introduced and applied in connection with the semi‐implicit coupling approach which can significantly decrease the computation time compared with the classical full‐implicit coupling approach [3]. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stabilization of sliding motion by partial stiction
Authors: Stamm Wolfgang 
Published: March 2011

AbstractRotating friction disks are utilized in many drivetrain components such as dry clutches and their actuator systems. Even the simplest pin‐on‐disk or disk‐on‐disk mechanical systems with Coulomb friction reveal a rich dynamical behavior with different types of motions.Examining the radial dynamics of minimal friction disk models, it is a prevalent assumption to have pure sliding frictional contacts. Governed by the systems' design parameters and initial conditions, stable large amplitude motions at higher rotation speeds are possible. Using a Coulomb friction model with sticking and sliding instead, gives similar motions with alternating phases of sticking and sliding. However, the amplitude can be decreased significantly by these intermittent phases of stick and slip. It is suggested to exploit such motions with partial stiction in order to reduce amplitudes and thus stabilize the systems.Similar effects can be observed in 3D‐multibody simulations and measurements of double clutch actuator systems. However, for these systems analytical treatment is not feasible any more due to the number of involved degrees of freedom. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metabolic Alterations of Withania somnifera (L.) Dunal Fruits at Different Developmental Stages by NMR Spectroscopy
Authors: Sidhu O. P. , Annarao Sanjay , Chatterjee Sandipan , Tuli Rakesh , Roy Raja , Khetrapal C. L. 
Published: March 2011

ABSTRACTIntroductionWithania somnifera (Ashwagandha) is a high‐value Ayurvedic medicinal plant and an important constituent of several dietary supplements. In order to substantiate the health claims, the herb has drawn considerable scientific attention.ObjectiveThe objective of the study was to investigate the alterations in primary and secondary metabolites of W. somnifera fruits during its maturity using NMR spectroscopy.MethodologyFruits at different stages of development from one week after fertilisation until maturity, classified in seven developmental stages, were analysed by a combined use of one‐ and two‐dimensional NMR experiments.ResultsSeventeen metabolites were characterised and quantified from non‐polar and polar extracts of different fruit development stages of W. somnifera. The principal component analysis of polar metabolites at different stages could be grossly classified into three metabolic phases, viz. initial phase, developmental phase and maturation phase.ConclusionQualitative and quantitative analysis of metabolites in W. somnifera fruits indicated specific stages when fruits can be harvested for obtaining substantial bioactive ingredients for desirable pharmacological activity. This study potentially provides a complementary tool for quality control of herbal medicinal products when W. somnifera fruits are used. Copyright © 2011 John Wiley & Sons, Ltd.
Quality Evaluation of Potentilla discolor by High‐performance Liquid Chromatography Coupled with Diode Array Detection and Electrospray Ionisation Tandem Mass Spectrometry
Authors: Yang Jie , Wen Xiao‐dong , Jia Bei‐xi , Mao Qian , Wang Qiang , Lai Mao‐xiang 
Published: March 2011

ABSTRACTIntroductionThe whole herb of Potentilla discolor has long been used for treatment of diarrhoea, malaria, haemoptysis and haematemesis in clinical applications. However, until now, there has been no literature regarding to the quality control of it.ObjectiveTo develop a simple and accurate HPLC‐DAD (diode array detection)–ESI/MSn (electrospray ionisation multistage mass spectrometry) method for the identification of constituents in P. discolor and simultaneous quantification of its marker compounds.MethodologySeparations were performed on a Shimpack C18 column by gradient elution using acetonitrile:0.1% formic acid. The identification of constituents in P. discolor were achieved by HPLC‐DAD‐ESI/MSn while six flavonoids and five triterpenoids were determined by HPLC‐DAD at 360 and 210 nm, repectively.ResultsA total of 23 compounds including 13 flavonoids and 10 triterpenoids were identified or tentatively characterised. A quantitative HPLC‐DAD method allowing the simultaneously quantification of 11 marker compounds was optimised and validated for linearity, precision, accuracy, and limits of detection and quantification. The method was successfully applied to the quantification of 11 marker compounds in 10 samples of P. discolor collected from different provinces of China.ConclusionThis developed method was validated as simple, precise and accurate, and could be used for effectively and comprehensibly evaluating the quality of P. discolor. Copyright © 2011 John Wiley & Sons, Ltd.
First trimester fetal head and trunk volume predict growth disturbance in twin pregnancy
Authors: Fajardo‐Expósito M. A. , Hervías B. , Bugatto González F. , Melero‐Jiménez V. , Quintero‐Prado R. , Facio‐Fernández M. C. , Bartha J. L. 
Published: March 2011

AbstractObjectiveTo evaluate the usefulness of first trimester fetal head and trunk volume (FHTV) in predicting growth disturbance in twin pregnancy.MethodsWe studied 46 twin pairs from 11 and 14 weeks to delivery. There were 35 dichorionic (76%) and 11 monochorionic (24%) pregnancies. FHTV was assessed by VOCALTM. An inter‐twin discrepancy in FHTV, crown–rump length (CRL) and birthweight (BW) were defined by an inter‐twin difference greater than 15%. Growth retardation was defined as BW of at least one twin below the 10th percentile.ResultsThere were 17 cases (37%) of FHTV discrepancy. BW discrepancy and growth retardation were more significantly frequent in cases with FHTV discrepancy than without [11/17 (64.7%) vs 4/29 (13.8%), P = 0.0004 and 7/17 (41.2%) vs 3/29 (10.3%), P = 0.02, respectively].The detection of BW discordance and growth retardation were significantly higher when using FHTV discordance than CRL discrepancy in the first trimester [11/15 (73%) vs 2/15 (13.3%), P = 0.00001 and 7/10 (70%) vs 1/10 (10%), P = 0.0001, respectively].ConclusionFHTV discrepancy is a predictor for growth disturbance in twins. Copyright © 2011 John Wiley & Sons, Ltd.
T2 quantifications of fetal lungs at MRI‐normal ranges
Authors: Cannie M. , Jani J. , De Keyzer F. , Roebben I. , Breysem L. , Deprest J. 
Published: March 2011

AbstractObjectiveTo prospectively determine the pattern of lung intensities and T2 values in fetuses with normally developing lungs as obtained with T2‐weighted single‐shot turbo spin echo magnetic resonance (TSE MR) imaging. This should serve as a reference to which images from fetuses with lung development disorders are compared.MethodsIn 105 fetuses with normal lung development who were assessed at 19 to 40 weeks of gestation, MR delineation of left and right lung organs was performed on the T2‐weighted images with TE of 31 ms and extrapolated to the images with echo time (TE) of 267 ms. T2 values were calculated based on the images with these two different TE. Linear regression analysis was used to assess the relationship between gestational age (GA) and T2. We compared T2 values in 11 left‐sided congenital diaphragmatic hernia (CDH) to the normative ranges using the Mann‐Whitney U test.ResultsIn fetuses with normal lungs and in CDH, there was a positive correlation between GA and T2 values in both lungs. T2 values, corrected for gestation, were lower in CDH fetuses for ipsilateral lungs as compared to normal lungs. Contralateral lungs showed no difference.ConclusionsIn normally developing lungs there is a significant relation between T2 values with gestation. Ipsilateral lungs in CDH have a significant difference in intensity. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of novel proton‐conducting highly sulfonated polybenzimidazoles for PEMFC and the effect of the type of bisphenyl bridge on polymer and membrane properties
Authors: Ng Feifei , Péron Jennifer , Jones Deborah J. , Rozière Jacques 
Published: March 2011

AbstractSix series of novel highly sulfonated polybenzimidazoles (sPBIs) with high molecular weight were prepared by direct polycondensation between 3,3′‐diaminobenzidine and original multisulfonated dinuclear dicarboxylic acids containing bridging ether, sulfone, and hexafluoroisopropylidene moieties. All reactions were carried out in polyphosphoric acid, which acts as both solvent and catalyst. The degree of sulfonation was modulated in the final products by varying the proportion of sulfonated to nonsulfonated dicarboxylic acids used in the synthesis. The high purity of the disulfonated and tetrasulfonated monomers allows wholly sulfonated homopolymers to be obtained. Confirmation of the chemical structure and the degree of sulfonation were derived from 1H nuclear magnetic resonance spectroscopy. Inherent viscosity was estimated as between 0.70 and 5.33 dL g−1 for sPBIs with ion exchange capacity in the range 0.87–4.68 mequiv g−1. Dynamic thermogravimetric analysis in air showed no weight loss below 350 °C (heating rate 5 °C min−1). The nature of the bisphenyl bridge has clear influence on the water uptake and proton conduction properties of the resulting sPBI membranes, with hexafluoroisopropylidene links providing materials of highest conductivity as well as favoring film‐forming characteristics. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and characterization of radiopaque poly(ether urethane) with iodine‐Containing diol as chain extender
Authors: Qu Weiqiang , Xia Weijuan , Feng Chao , Tuo Xinlin , Qiu Teng 
Published: March 2011

AbstractNovel radiopaque iodinated poly(ether urethane) (IPEU) was prepared by using iodine‐containing diol as chain extender in a normal two‐step condensation polymerization process. This new iodine‐containing diol was synthesized by iodination of terephthalic acid and then reaction with 3‐aminopropanol. The chemical structure of the diol chain extender and IPEU was characterized, and the basic properties of IPEU were measured and compared with PEU. X‐ray images showed that 15 wt % iodine‐containing IPEUs were highly radiopaque, and radiopacity did not decrease after 6‐week oxidative degradation treatment. Experimental results showed that IPEUs possessed good thermal stability, favorable mechanical properties, and noncytotoxicity. These results reveal that it is an effective route for the synthesis of biological polyurethane with radiopacity by using iodine‐containing diol as chain extender. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011