bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non‐viral gene delivery transfection profiles influence neuronal architecture in an in vitro co‐culture model
Authors: Houchin‐Ray Tiffany , Zelivyanskaya Marina , Huang Alyssa , Shea Lonnie D. 
Published: March 2009

AbstractGene delivery from tissue engineering scaffolds can induce expression of tissue inductive factors to stimulate the cellular processes required for regeneration. Transfected cells secrete diffusible proteins that can create local concentration gradients, depending on the number, distribution, and expression level of transfected cells. These gradients are linked to cellular organization and tissue architecture during embryogenesis. In this report, we investigate neuronal architecture and neurite guidance in response to the concentration gradients achieved by localized secretion of a neurotrophic factor from transfected cells. A co‐culture model was employed to examine neuronal responses to multiple transfection profiles, which affects the local concentration of secreted nerve growth factor (NGF). Neuronal architecture, as defined by number of neurites per neuron and length of neurites, was influenced by the transfection profile. Low levels of NGF production by few transfected cells produced longer primary neurites with less branching relative to the higher expression levels or increased numbers of transfected cells. Furthermore, for low NGF production by few transfected cells, the growth cone of the axons was marked by longer extensions and larger surface area, suggesting the presence of a guidance cue. Control studies with varying NGF concentrations did not substantially alter the neuronal architecture, further supporting an effect of localized concentration gradients, and not simply the concentration. Mathematical modeling of NGF diffusion was employed to predict the concentration gradients produced by the transfection profiles, and the resultant gradients were correlated to the cellular response. This report connects the transfection profile, concentration gradients, and the resulting cellular architecture, suggesting a critical design consideration for the application of gene delivery to regenerative medicine. Biotechnol. Bioeng. 2009;103: 1023–1033. © 2009 Wiley Periodicals, Inc.
Dissection of Two Acyl‐Transfer Reactions Centered on Acyl‐S‐Carrier Protein Intermediates for Incorporating 5‐Chloro‐6‐methyl‐O‐methylsalicyclic Acid into Chlorothricin
Authors: He Qing‐Li , Jia Xin‐Ying , Tang Man‐Cheng , Tian Zhen‐Hua , Tang Gong‐Li , Liu Wen 
Published: March 2009

AbstractMaking the microbes work for us: An acyl‐carrier‐protein‐centered strategy that involves two distinct acyl‐transfer steps for generation and regiospecific attachment of the 5‐chloro‐6‐methyl‐O‐methylsalicyl group onto the C3′ position of D‐olivose was elucidated in the biosynthetic pathway of chlorothricin. Identification of the mutant of the acyltransferase‐associated intermediate validated the critical role of the highly conserved Cys residue, which channels the acyl transfer by using its thiolate side chain as a nucleophile in a two‐step process.magnified image
Cell‐Permeable β‐Peptide Inhibitors of p53/hDM2 Complexation
Authors: Harker Elizabeth A. , Schepartz Alanna 
Published: March 2009

AbstractLook at what the cat(ionic motif) dragged in! We report a general strategy to increase the cell permeability of β3‐peptides. Introduction of a minimal cationic motif within the folded structure of a high‐affinity β3‐peptide ligand for hDM2 led to molecules with high 314‐helical structure, high hDM2 affinity and sufficient cell permeability to upregulate p53‐dependent genes in live mammalian cells. Minimally cationic β3‐peptides represent the critical first step towards a class of protease‐resistant peptidomimetics that might modulate intracellular biological pathways.magnified image
Design of Protein–Protein Interaction Inhibitors Based on Protein Epitope Mimetics
Authors: Robinson John A. 
Published: March 2009

AbstractOn the scaffold: Grafting protein epitopes onto conformationally designed scaffolds represents a very promising approach to protein ligand design, with potential applications in many areas of chemical biology and molecular medicine. The highlighted article describes the design and anticancer activity of novel p53/MDM2 inhibitors built upon a scorpion toxin scaffold. Other approaches to protein epitope mimetics are also briefly discussed.magnified image
Green Medium for the Hydrolysis of 5‐Cyanovaleramide
Authors: Duan P.‐G. , Li S. , Yang Y. , Wang Z.‐Z. , Dai L.‐Y. 
Published: March 2009

AbstractHydrolysis of 5‐cyanovaleramide (5‐CVAM) in near‐critical water without the addition of any catalyst has been demonstrated. The results demonstrated that the cyano group at one end of the carbon of 5‐CVAM is more reactive than the amide group at the other end, under the same experimental conditions. The relations between 5‐CVAM concentration and residence time revealed that hydrolysis of 5‐CVAM shows second‐order reaction kinetics in the investigated temperature range. The rate constants, average apparent activation energy and pre‐exponential factor were evaluated according to the Arrhenius equation. Based on the experimental results, a carbon balance was calculated, and a hydrolysis reaction scheme of 5‐CVAM was proposed.
Tuning of Electronic Properties of Single‐Walled Carbon Nanotubes under Homogenous Conditions
Authors: Maeda Yutaka , Sagara Akiko , Hashimoto Masahiro , Hirashima Yuya , Sode Katsuya , Hasegawa Tadashi , Kanda Makoto , Ishitsuka Midori O. , Tsuchiya Takahiro , Akasaka Takeshi , Okazaki Toshiya , Kataura Hiromichi , Lu Jing , Nagase Shigeru , Takeuchi Seiji 
Published: March 2009

AbstractReversible and non‐bonding interaction between SWNTs and ODCB is observed from the analyses of visible near‐infrared absorption data and Raman spectroscopies (see spectra). The solvent effect on SWNTs effectively controls the electronic structure of SWNTs under homogeneous conditions.magnified imageThe dispersion of single‐walled carbon nanotubes (SWNTs) in o‐dichlorobenzene (ODCB) is studied. Reversible and non‐bonding interaction between SWNTs and ODCB is observed from the analyses of visible near‐infrared (Vis‐NIR) absorption data and Raman spectroscopy. This interaction should be one of the important factors for stable dispersion of SWNTs in ODCB. The solvent effect on SWNTs effectively controls the electronic structure of SWNTs under homogeneous conditions.
Dynamics of gonococcal type IV pili during infection
Authors: Opitz Dirk , Clausen Martin , Maier Berenike 
Published: March 2009

AbstractKeep that motor running: Type IV pili are among the strongest molecular motors characterized to date. Herein it is reported that pilus motors of the human pathogen Neisseria gonorrhoeae are very active for at least one day post‐infection of epithelial cells. They generate force in the range on 70 pN and retract at a higher velocity as compared to abiotic environments (see picture).magnified imageType IV pili are important bacterial virulence factors that mediate attachment to mammalian host cells and elicit downstream signals. When adhered to abiotic surfaces, the human pathogen Neisseria gonorrhoeae generates force by retracting these polymeric cell appendages. We recently found that single pili generate stalling forces that exceed 100 pN, but it is unclear whether bacteria generate force once they adhere to their human host cells. Here, we report that pili retract very actively during infection of human epithelial cells. The retraction velocity is bimodal and the high velocity mode persisted at higher forces in contrast to an abiotic environment. Bacteria generate considerable force during infection, but the maximum force is reduced from 120±40 pN on abiotic surfaces to 70±20 pN on epithelial cells, most likely due to elastic effects. Velocity and maximum force of pilus retraction are largely independent of the infection period within 1 h and 24 h post‐infection. Thus, the force generated by type IV pili during infection is high enough to induce cytoskeletal rearrangements in the host cell.
Electron‐Capture‐Induced Dissociation of Microsolvated Di‐ and Tripeptide Monocations: Elucidation of Fragmentation Channels from Measurements of Negative Ions
Authors: Zettergren Henning , Adoui Lamri , Bernigaud Virgile , Cederquist Henrik , Haag Nicole , Holm Anne I. S. , Huber Bernd A. , Hvelplund Preben , Johansson Henrik , Kadhane Umesh , Koefoed Larsen Mikkel , Liu Bo , Manil Bruno , Brøndsted Nielsen Steen , Panja Subhasis , Rangama Jimmy , Reinhed Peter , Schmidt Henning T. , Støchkel Kristian 
Published: March 2009

AbstractThe branching ratio between ammonia loss and NCα bond cleavage of singly charged microsolvated peptides after electron capture from cesium depends on the solvent molecule attached. Density functional calculations reveal that for [GA+H]+(CE) (G=glycine, A=alanine, CE=crown ether), the singly occupied molecular orbital of the neutral radical is located mainly on the amide group (see picture).magnified imageThe results from an experimental study of bare and microsolvated peptide monocations in high‐energy collisions with cesium vapor are reported. Neutral radicals form after electron capture from cesium, which decay by H loss, NH3 loss, or NCα bond cleavage into characteristic z. and c fragments. The neutral fragments are converted into negatively charged species in a second collision with cesium and are identified by means of mass spectrometry. For protonated GA (G=glycine, A=alanine), the branching ratio between NH3 loss and NCα bond cleavage is found to strongly depend on the molecule attached (H2O, CH3CN, CH3OH, and 18‐crown‐6 ether (CE)). Addition of H2O and CH3OH increases this ratio whereas CH3CN and CE decrease it. For protonated AAA ([AAA+H]+), a similar effect is observed with methanol, while the ratio between the z1 and z2 fragment peaks remains unchanged for the bare and microsolvated species. Density functional theory calculations reveal that in the case of [GA+H]+(CE), the singly occupied molecular orbital is located mainly on the amide group in accordance with the experimental results.
On the Origin of the “Giant” Electroclinic Effect in a “De Vries”‐Type Ferroelectric Liquid Crystal Material for Chirality Sensing Applications
Authors: Kapernaum Nadia , Walba David M. , Korblova Eva , Zhu Chenhui , Jones Chris , Shen Yongqian , Clark Noel A. , Giesselmann Frank 
Published: March 2009

AbstractW415 is a chiral smectic compound with a remarkably weak temperature dependence of its giant electroclinic effect in the liquid crystalline smectic A* phase. Furthermore it possesses a high spontaneous polarization in the smectic C* phase. The origin of this striking electroclinic effect is the co‐occurrence of a de Vries‐type ordering with a weak first‐order tilting transition (see the synchroton X‐ray scattering profiles).magnified image
Sustainability evaluation of biodiesel production using multicriteria decision‐making
Authors: Dinh Linh T.T. , Guo Yuyan , Mannan M. Sam 
Published: March 2009

AbstractHigher crude‐oil prices, increases in energy imports, concerns about petroleum supplies, and greater recognition of environmental consequences of fossil fuels have spurred a search for alternative sources of fuel. In the aspect of choosing an appropriate source for a long‐term development, it is necessary to decide which is the most sustainable. This article describes a systematic method based on Analytical Hierarchical Process technique to compare biodiesel feedstock alternatives on technical, economical, and sustainable aspects throughout life cycles of biodiesel production. Five biodiesel feedstocks which are jatropha, algae, palm oil, rapeseed, and soybean are taken into consideration in a quantified evaluation. Among these alternatives and with a recommended scoring structure, biodiesel from algae is shown in the calculation results to be the highest ranking substitute for diesel fuel due to its overall better performance in the aspects of environment, economical, safety, raw material performance, and fuel performance. © 2009 American Institute of Chemical Engineers Environ Prog, 2009
Toward developing competent evaluation managing
Authors: Baizerman Michael , Compton Donald W. 
Published: March 2009

AbstractHere the essentials of the expertise of managing are presented as orientation toward (ethos, stance, and gaze), knowledge about, and knowledge how‐to (“know‐how”). These are grounded to specific content, summarized, and then connected to a typology of managing evaluation. The orienting questions for the field are reviewed to reveal what it means to prepare expert evaluation managers and expertise in managing evaluation. This includes very brief introductions to curricula, pedagogy, and learning styles. A short discussion presents a proposed managing career path for evaluators and nonevaluators. The chapter ends with two answers to focal questions of the text and a stance for the profession on the practice and preparation for managing evaluation. © Wiley Periodicals, Inc.
Kinematics of level terrestrial and underwater walking in the California newt, Taricha torosa
Authors: Ashley‐Ross Miriam A. , Lundin Rebecca , Johnson Kristy L. 
Published: March 2009

AbstractSalamanders are acknowledged to be the closest postural model of early tetrapods and are capable of walking both in a terrestrial environment and while submerged under water. Nonetheless, locomotion in this group is poorly understood, as is underwater pedestrian locomotion in general. We, therefore, quantified the movements of the body axis and limbs of the California newt, Taricha torosa, during steady‐speed walking in two environments, both of which presented a level surface: a treadmill and a trackway that was submerged in an aquarium. For treadmill walking at a relative speed of 0.63 snout–vent lengths (SVL)/sec, newts used a diagonal couplets lateral sequence walk with a duty factor of 77%. In contrast, submerged speeds were nearly twice as fast, with a mean of 1.19 SVL/sec. The submerged gait pattern was closer to a trot, with a duty factor of only 41%, including periods of suspension. Environment appears to play a critical role in determining gait differences, with reduction of drag being one of the most important determinants in increasing duration of the swing phase. Quantitative analysis of limb kinematics showed that underwater strides were more variable than terrestrial ones, but overall were strikingly similar between the two environments, with joint movement reversals occurring at similar points in the step cycle. It is suggested that the fundamental walking pattern appears to function well under multiple conditions, with only minor changes in motor control necessary. J. Exp. Zool. 311A:240–257, 2009. © 2009 Wiley‐Liss, Inc.
Molecularly imprinted polymer for solid‐phase extraction of ephedrine and analogs from human plasma
Authors: Lasáková Martina , Thiébaut Didier , Jandera Pavel , Pichon Valérie 
Published: March 2009

AbstractA molecularly imprinted polymer (MIP) was synthesized and evaluated to selectively extract ephedrine from human plasma. The MIP synthesis was performed in chloroform with methacrylic acid as a functional monomer and the target alkaloid as a template molecule. The resulting MIP was applied to the selective extraction of ephedrine from a pure aqueous medium. A recovery about 74% was obtained using the MIP with only 7% on the nonimprinted polymer (NIP). A very straightforward selective SPE procedure was then successfully applied to the direct extraction of ephedrine from spiked human plasma with a high extraction recovery (68%) on the MIP with no recovery on the NIP. Moreover, the MIP was used for the selective extraction of catecholamine neurotransmitters, i.e. adrenaline and noradrenaline.
Structure determination of Aervins A‐D, new coumaronochromone analogues from Aerva persica, by 1D and 2D NMR spectroscopy
Authors: Imran Muhammad , Ibrahim Muhammad , Riaz Naheed , Malik Abdul 
Published: March 2009

AbstractAervins A‐D (1‐4), four new coumaronochromone analogues have been isolated from the CHCl3‐soluble fraction of the MeOH extract of the whole plant of Aerva persica. Their structures were assigned based on 1H NMR, 13C NMR spectra, DEPT, and by 2DNMR experiments. Copyright © 2009 John Wiley & Sons, Ltd.
Simulation of brittle crack growth in functionally graded materials
Authors: Mahnken Rolf 
Published: March 2009

AbstractWe consider a thermodynamic consistent framework for crack propagation by applying a dissipation inequality to a time dependent migrating control volume. The direction of crack growth is obtained in terms of material forces as a result of the principle of maximum dissipation. In the numerical implementation a staggered algorithm – deformation update for fixed geometry followed by geometry update for fixed deformation – is employed within each time increment. The corresponding mesh is generated by combining Delaunay triangulation with local mesh refinement. A numerical example with inhomogeneous material properties illustrates the capability of the resulting algorithm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Perturbation Sensitivity and Limit Loads of Shells
Authors: Pontow J. , Dinkler D. 
Published: March 2009

AbstractThe perturbation sensitivity and its influence on the limit loads of shells are widely discussed phenomena. Both phenomena may be classified with respect to the type of perturbation. As perturbations influence the stability of shells, the identification of unfavourable perturbations is essential. The perturbation energy concept enables to identify unfavourable non–initial perturbation loads and to evaluate the perturbation sensitivity of fundamental states by the perturbation energy. This measure is also the basis for a load–level–specific optimisation of the perturbation sensitivity. Hence, the present paper discusses primarily the perturbation sensitivity of axially loaded cylindrical shells with different boundary conditions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Longitudinal track‐bridge interaction due to loading sequences
Authors: Widarda D.R. , Ruge P. , Birk C. 
Published: March 2009

AbstractFor continuously welded rails the longitudinal track–bridge interaction plays an important role. The coupling between track and bridge consists of a ballasted interface or a slab track with rail–pads.European codes describe this coupling by means of a bilinear force–displacement relation with making a difference wether the track is loaded or not.This contribution is focussed on an incremental treatment of the long–term loading from seasonal temperature–change followed by several cycles unloaded–loaded–unloaded due to passing trains. As one cycle happens in a rather short time, the mass accelerations are involved, too. The load–character of the coupling–variation will be explained and a comparison between a statical and a dynamical treatment will be presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Overexpression of Akt/PKB modulates N‐myristoyltransferase activity in cancer cells
Authors: Shrivastav Anuraag , Varma Shailly , Senger Arnie , Khandelwal Ramji L , Carlsen Svein , Sharma Rajendra K 
Published: March 2009

AbstractN‐myristoyltransferase (NMT) catalyses the myristoylation reaction. Since NMT activity is elevated in various cancers and activated Akt/PKB leads to cell survival, we were interested in studying if activation of Akt/PKB has any effect on NMT. Overexpression of constitutively active Akt/PKB in HepG2 cells (HepG2‐CA‐Akt/PKB) led to an approximately 50% reduction of NMT compared with parental HepG2 cells. Reduced NMT activity in HepG2‐CA‐Akt/PKB was found to be due to the NMT1 phosphorylation. We determined NMT activity in various human breast cancer cell lines with differing metastatic potentials and pseudo‐normal breast cells (HBL‐100). Tumourigenic or metastatic breast cancer cell lines such as MDA‐MB‐231, MDA‐MB‐435, and Hs 578T displayed reduced NMT activity. Western blot analysis revealed that NMT1 is phosphorylated in these breast cancer cells. Furthermore, patients' breast cancer tissue array revealed strong positivity and high intensity for NMT in malignant breast tissues compared with normal breast cells. A gradation in the NMT staining was observed for grade I, II, and III infiltrating ductal carcinoma breast tissues. These studies demonstrate that overexpression of Akt/PKB results in NMT1 phosphorylation and that NMT1 is phosphorylated in breast cancer cells. Immunohistochemical analysis suggests that NMT may prove to be an added diagnostic biomarker for breast cancer. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
New genetic opportunities from legume intercrops for controlling Striga spp. parasitic weeds
Authors: Hooper Antony M , Hassanali Ahmed , Chamberlain Keith , Khan Zeyaur , Pickett John A 
Published: March 2009

AbstractIn smallholder farming in East Africa, intercropping of maize with the cattle forage legume, Desmodium uncinatum Jacq., prevents parasitism by Striga hermonthica (Del.) Benth. (witchweed) through an allelopathic mechanism. Isoschaftoside, a di‐C‐glycosylflavone, isolated from the root extract and root exudate of Desmodium, interferes with in vitro radicle development of germinated Striga. The biosynthetic pathway of this class of compound is already mostly present in edible legumes and in cereals, so characterisation of the enzyme and genes that control C‐glycosylflavone biosynthesis has the potential to create this protection mechanism in other agriculturally important plants. Copyright © 2009 Society of Chemical Industry
Interconnection between ground state and excited state gain in InAs/GaAs quantum dot semiconductor optical amplifiers
Authors: Crowley M. T. , Andreev A. D. , Piwonski T. , Houlihan J. , O'Reilly E. P. , Huyet G. 
Published: March 2009

AbstractDifferent energy levels are generally assumed to be associated with ground state (GS) and excited state (ES) gain in semiconductor quantum dot lasers and amplifiers. We present calculations based on an 8 band k ·P Hamiltonian which show that this is not the case. Two distinct absorption bands are calculated due to transitions between the GS electrons and all dot hole states. In addition to the peak due to transitions between GS electron and GS hole levels, a higher energy band is also calculated due to transitions between GS electrons and highly excited dot hole states. We demonstrate that the removal of electron–hole pairs through stimulated emission at the ES gain maximum can result in an amplitude reduction for a probe pulse tuned to the GS gain maximum, due to the existence of these higher energy transitions, and also due to the effects of two photon absorption. We also find that the instantaneous phase change at the ES gain maximum due to dot to dot interband transitions is small compared to the measured value. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)