bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioinspired peptide nanotubes: deposition technology, basic physics and nanotechnology applications
Authors: Rosenman G. , Beker P. , Koren I. , Yevnin M. , Bank‐Srour B. , Mishina E. , Semin S. 
Published: December 2010

AbstractSynthetic peptide monomers can self‐assemble into PNM such as nanotubes, nanospheres, hydrogels, etc. which represent a novel class of nanomaterials. Molecular recognition processes lead to the formation of supramolecular PNM ensembles containing crystalline building blocks. Such low‐dimensional highly ordered regions create a new physical situation and provide unique physical properties based on electron‐hole QC phenomena. In the case of asymmetrical crystalline structure, basic physical phenomena such as linear electro‐optic, piezoelectric, and nonlinear optical effects, described by tensors of the odd rank, should be explored. Some of the PNM crystalline structures permit the existence of spontaneous electrical polarization and observation of ferroelectricity. The PNM crystalline arrangement creates highly porous nanotubes when various residues are packed into structural network with specific wettability and electrochemical properties.We report in this review on a wide research of PNM intrinsic physical properties, their electronic and optical properties related to QC effect, unique SHG, piezoelectricity and ferroelectric spontaneous polarization observed in PNT due to their asymmetric structure. We also describe PNM wettability phenomenon based on their nanoporous structure and its influence on electrochemical properties in PNM.The new bottom‐up large scale technology of PNT physical vapor deposition and patterning combined with found physical effects at nanoscale, developed by us, opens the avenue for emerging nanotechnology applications of PNM in novel fields of nanophotonics, nanopiezotronics and energy storage devices. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Photocurrent generation through peptide‐based self‐assembled monolayers on a gold surface: antenna and junction effects
Authors: Gatto Emanuela , Caruso Mario , Porchetta Alessandro , Toniolo Claudio , Formaggio Fernando , Crisma Marco , Venanzi Mariano 
Published: December 2010

AbstractThe photocurrent generation properties of mono‐ and bi‐component peptide‐based self‐assembled monolayers (SAMs) immobilized on a gold surface were studied by electrochemical and spectroscopic techniques. The peptides investigated comprised almost exclusively Cα‐tetrasubstituted α‐amino acids. These non‐coded residues, because of their unique conformational properties, forced the peptide backbone to attain a helical conformation, as confirmed by X‐ray crystal structure and CD determinations in solution. The peptide helical structure promoted the formation of a stable SAM on the gold surface, characterized by an electric macrodipole directed from the C(δ−) to the N(δ+) terminus, that remarkably affected the electron transfer (ET) process through the peptide chain. The peptides investigated were derivatized with chromophores strongly absorbing in the UV region to enhance the efficiency of the photocurrent generation (antenna effect). The influence of the nature of the peptide–gold interface on the ET process (junction effect) was analyzed by comparing the photocurrent generation process in peptide SAMs immobilized on a gold surface through AuS linkages with that in a bi‐component SAM embedding a photoactive peptide into the linked palisade formed by disulfide‐functionalized peptides. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
De novo design of orthogonal peptide pairs forming parallel coiled‐coil heterodimers
Authors: Gradišar Helena , Jerala Roman 
Published: December 2010

AbstractWe used the principles governing the selectivity and stability of coiled‐coil segments to design and experimentally test a set of four pairs of parallel coiled‐coil‐forming peptides composed of four heptad repeats. The design was based on maximizing the difference in stability between desired pairs and the most stable unwanted combinations using N‐terminal helix initiator residues, favorable combinations of the electrostatic and hydrophobic interaction motifs and negative design motif based on burial of asparagine residues. Experimental analysis of all 36 pair combinations among the eight peptides was performed by circular dichroism (CD). On the basis of CD spectra, each peptide formed a high level of α‐helical structure exclusively in combination with its designed peptide partner which demonstrates the orthogonality of the designed peptide pair set. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Synthesis and self‐assembly of a neoglycopeptide: morphological studies and ultrasound‐mediated DNA encapsulation
Authors: Gour Nidhi , Mondal Sudipta , Verma Sandeep 
Published: December 2010

AbstractSelf‐assembly in peptides and proteins is an often encountered concept, where constituent building blocks are recruited and stabilized, via carefully orchestrated hydrophobic interactions, hydrogen bonding and other non‐covalent interactions, to eventually reveal an array of supramolecular aggregates, with defined structural features. This study presents synthesis and self‐assembly of a mannosylated peptide in aqueous medium. Turbidimetric assay with Concanavalin A (Con A), a mannose binding protein, was conducted to confirm the presence of hydrophilic mannose group on the exterior surface of self‐assembled structures. DNA encapsulation in these soft structures was achieved by ultrasonication of soft spherical structures in the presence of plasmid DNA. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Self‐assembly of amphiphilic β‐sheet peptide tapes based on aliphatic side chains
Authors: Davies Robert Philip Wynn , Aggeli Amalia 
Published: December 2010

AbstractAmphiphilic β‐sheet nanotapes based on the self‐assembly of 9mer and 7mer de novo designed β‐strand peptides were studied in the dilute regime. The hydrophobic face of the tapes consisted predominantly of aliphatic (leucine) side chains, while the hydrophilic tape face contained polar side chains (glutamine, arginine and glutamic acid). Both peptides underwent a transition from a monomeric random coil to a self‐assembled β‐sheet tape upon increase of peptide concentration in aqueous solutions. P9‐6 exhibited lower critical concentration (c*) for self‐assembly and thus higher propensity for self‐assembly in water, compared to the shorter P7‐6. At neutral pH where there was little net charge per peptide, self‐assembly was favoured compared to low pH in which there was a net + 1 charge per peptide; the net charge decreased overall intermolecular attraction, manifested as an increase in c* for self‐assembly in low compared to neutral pH aqueous solutions. Propensity for self‐assembly and β‐sheet formation was found to be greatly enhanced in a polar organic solvent (methanol) compared to water. These studies combined with future more extensive comparative studies between amphiphilic tapes based on aliphatic amino acid residues and amphiphilic tapes based on aromatic residues will throw more light on the relative importance of hydrophobic versus aromatic interactions for the stabilisation of peptide assemblies. Systematic studies of this kind may also allow us to throw light on the fundamental principles that drive peptide self‐assembly and β‐sheet formation; they may also lead to a set of refined criteria for the effective design of peptides with prescribed combination of properties appropriate for specific applications. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Sequential methods for random‐effects meta‐analysis
Authors: Higgins Julian P. T. , Whitehead Anne , Simmonds Mark 
Published: December 2010

AbstractAlthough meta‐analyses are typically viewed as retrospective activities, they are increasingly being applied prospectively to provide up‐to‐date evidence on specific research questions. When meta‐analyses are updated account should be taken of the possibility of false‐positive findings due to repeated significance tests. We discuss the use of sequential methods for meta‐analyses that incorporate random effects to allow for heterogeneity across studies. We propose a method that uses an approximate semi‐Bayes procedure to update evidence on the among‐study variance, starting with an informative prior distribution that might be based on findings from previous meta‐analyses. We compare our methods with other approaches, including the traditional method of cumulative meta‐analysis, in a simulation study and observe that it has Type I and Type II error rates close to the nominal level. We illustrate the method using an example in the treatment of bleeding peptic ulcers. Copyright © 2010 John Wiley & Sons, Ltd.
Estimating propensity scores with missing covariate data using general location mixture models
Authors: Mitra Robin , Reiter Jerome P. 
Published: December 2010

AbstractIn many observational studies, analysts estimate causal effects using propensity scores, e.g. by matching, sub‐classifying, or inverse probability weighting based on the scores. Estimation of propensity scores is complicated when some values of the covariates are missing. Analysts can use multiple imputation to create completed data sets from which propensity scores can be estimated. We propose a general location mixture model for imputations that assumes that the control units are a latent mixture of (i) units whose covariates are drawn from the same distributions as the treated units' covariates and (ii) units whose covariates are drawn from different distributions. This formulation reduces the influence of control units outside the treated units' region of the covariate space on the estimation of parameters in the imputation model, which can result in more plausible imputations. In turn, this can result in more reliable estimates of propensity scores and better balance in the true covariate distributions when matching or sub‐classifying. We illustrate the benefits of the latent class modeling approach with simulations and with an observational study of the effect of breast feeding on children's cognitive abilities. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐Photon‐Sensitive and Sugar‐Targeted Nanocarriers from Degradable and Dendritic Amphiphiles
Authors: Sun Lin , Yang Yang , Dong Chang‐Ming , Wei Yen 
Published: December 2010

AbstractIncreasing efforts are being put into the light‐sensitive polymeric micelles that hold great potential for drug/gene/small interfering RNA delivery. However, these polymeric micelles lack highly efficient tumor‐targeting properties and near‐infrared light sensitivity, and often exhibit an uncontrollable drug‐release profile. To address these problems, a new strategy is introduced that combines sugar‐triggered targeting (active targeting) and two‐photon sensitivity to afford a degradable and dendritic micellar nanocarrier, in which the desired sugar residues and light‐responsive groups can be modularly conjugated and/or altered. A clinical anticancer drug, doxorubicin, can be released in a controlled manner by changing the light irradiation time, which is induced by the gradual disruption of micelles in aqueous solution. The glucose‐ and lactose‐coated micelles further demonstrate specific binding with the lectins Concanavalin A and Ricinus communis agglutinin, respectively, which makes them useful as targeted drug‐delivery vesicles.
Sensitivity of kinetic macro parameters to changes in dopamine synthesis, storage, and metabolism: A simulation study for [18F]FDOPA PET by a model with detailed dopamine pathway
Authors: Matsubara Keisuke , Watabe Hiroshi , Kumakura Yoshitaka , Hayashi Takuya , Endres Christopher J. , Minato Kotaro , Iida Hidehiro 
Published: December 2010

AbstractQuantitative interpretation of brain [18F]FDOPA PET data has been made possible by several kinetic modeling approaches, which are based on different assumptions about complex [18F]FDOPA metabolic pathways in brain tissue. Simple kinetic macro parameters are often utilized to quantitatively evaluate metabolic and physiological processes of interest, which may include DDC activity, vesicular storage, and catabolism from 18F‐labeled dopamine to DOPAC and HVA. A macro parameter most sensitive to the changes of these processes would be potentially beneficial to identify impaired processes in a neurodegenerative disorder such as Parkinson's disease. The purpose of this study is a systematic comparison of several [18F]FDOPA macro parameters in terms of sensitivities to process‐specific changes in simulated time‐activity curve (TAC) data of [18F]FDOPA PET. We introduced a multiple‐compartment kinetic model to simulate PET TACs with physiological changes in the dopamine pathway. TACs in the alteration of dopamine synthesis, storage, and metabolism were simulated with a plasma input function obtained by a non‐human primate [18F]FDOPA PET study. Kinetic macro parameters were calculated using three conventional linear approaches (Gjedde‐Patlak, Logan, and Kumakura methods). For simulated changes in dopamine storage and metabolism, the slow clearance rate (kloss) as calculated by the Kumakura method showed the highest sensitivity to these changes. Although kloss performed well at typical ROI noise levels, there was large bias at high noise level. In contrast, for simulated changes in DDC activity it was found that Ki and VT, estimated by Gjedde‐Patlak and Logan method respectively, have better performance than kloss. Synapse 2011. © 2011 Wiley‐Liss, Inc.
Chronic corticosterone exposure alters postsynaptic protein levels of PSD‐95, NR1, and synaptopodin in the mouse brain
Authors: Cohen Julia W. , Louneva Natalia , Han Li‐Ying , Hodes Georgia E. , Wilson Robert S. , Bennett David A. , Lucki Irwin , Arnold Steven E. 
Published: December 2010

AbstractAnimal models provide compelling evidence that chronic stress is associated with biochemical and morphological changes in the brain, many of which are mediated by corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex and secreted in response to stress. To better characterize the effects of chronic corticosterone at the synaptic and subsynaptic level, we implanted three‐month‐old male C57B/6 mice with 2 × 5 mg corticosterone pellets (CORT group,n= 14), 21 day release formulation (20 mg/kg/day dose) or placebo pellets (Placebo group,n= 14), 21‐day release formulation. After 20 days, brains were removed. One hemisphere was frozen for biochemical analysis by synaptosomal fractionation with Western blotting, and the other hemisphere was fixed for immunohistochemistry. Localization and expression levels for PSD‐95, NR1, and synaptopodin proteins were assessed. Biochemical analysis revealed lower protein levels of PSD‐95 (32% decrease,P< 0.001), NR1 (47%,P= 0.01), and synaptopodin (65%,P< 0.001) in the postsynaptic density subsynaptic fraction of the CORT group. Optical densitometry in immunohistochemically labeled sections also found lower levels of PSD‐95 in synaptic fields of the dentate gyrus (PSD‐95, 33% decrease,P< 0.001; NR1, 31%,P< 0.001; synaptopodin, 40%,P< 0.001) and the CA3 stratum lucidum (36%,P< 0.001, 40%,P< 0.001, and 35%,P< 0.001) of the CORT group. While mechanistic relationships for these changes are not yet known, we speculate that synaptopodin, which is involved in regulation of spine calcium kinetics and posttranslational modification and transport of locally synthesized proteins, may play an important role in the changes of PSD‐95 and NR1 protein levels and other synaptic alterations. Synapse 2011. © 2011 Wiley‐Liss, Inc.
Differential long‐term depression in CA3 but not in dentate gyrus following low‐frequency stimulation of the medial perforant path
Authors: Fung Thomas K. , Peloquin Pascal , Wu Kun , Leung L. Stan 
Published: December 2010

AbstractSynaptic plasticity may depend not only on the afferent fibers but also on the recipient structure. The medial perforant path (MPP) from the entorhinalcortex projects to both the dentate gyrus (DG) and CA3, resulting in excitatory postsynaptic potentials (EPSPs) in both areas. In this study, we showed that long‐term depression (LTD) following low‐frequency stimulation of MPP was found only in CA3a, a CA3 subfield, but not in DG. Field potentials were recorded and current source density (CSD) analyzed in CA3a and DG following stimulation of MPP in urethane‐anesthetized rats. MPP evoked a short‐latency population spike (PS) and EPSP in CA3a, <2.5 ms delayed from the respective events in DG. A small electrolytic lesion of CA3a abolished the locally recorded PS in CA3a but did not affect the responses in the DG. Low‐frequency stimulation of the MPP for 600 pulses at 5 Hz, but not at 1 Hz, resulted in LTD of up to 2 h in CA3a but not in DG. High‐frequency stimulation (400 Hz bursts) of the MPP resulted in long‐term potentiation (LTP) in both CA3a and DG. LTD at CA3a was blocked by a prior intracerebroventricular administration of an N‐methyl‐D‐aspartate receptor (NMDAR) antagonist DL‐2‐amino‐5‐phosphonovaleric acid or a nonselective group I/II metabotropic glutamate receptor (mGluR) antagonist (RS)‐α‐methyl‐4‐carboxyphenylglycine. We conclude that an NMDAR and mGluR sensitive LTD is induced in CA3 but not in the DG following low‐frequency MPP stimulation in vivo, and the bi‐directional synaptic plasticity in CA3 may be responsible for its behavioral functions. Synapse, 2011. © 2011 Wiley‐Liss, Inc.
Methamphetamine treatment during development attenuates the dopaminergic deficits caused by subsequent high‐dose methamphetamine administration
Authors: Mcfadden Lisa M. , Hoonakker Amanda J. , Vieira‐Brock Paula L. , Stout Kristen A. , Sawada Nicole M. , Ellis Jonathan D. , Allen Scott C. , Walters Elliot T. , Nielsen Shannon M. , Gibb James W. , Alburges Mario E. , Wilkins Diana G. , Hanson Glen R. , Fleckenstein Annette E. 
Published: December 2010

AbstractAdministration of high doses of methamphetamine (METH) causes persistent dopaminergic deficits in both nonhuman preclinical models and METH‐dependent persons. Noteworthy, adolescent [i.e., postnatal day (PND) 40] rats are less susceptible to this damage than young adult (PND90) rats. In addition, biweekly treatment with METH, beginning at PND40 and continuing throughout development, prevents the persistent dopaminergic deficits caused by a “challenge” high‐dose METH regimen when administered at PND90. Mechanisms underlying this “resistance” were thus investigated. Results revealed that biweekly METH treatment throughout development attenuated both the acute and persistent deficits in VMAT2 function, as well as the acute hyperthermia, caused by a challenge METH treatment. Pharmacokinetic alterations did not appear to contribute to the protection afforded by the biweekly treatment. Maintenance of METH‐induced hyperthermia abolished the protection against both the acute and persistent VMAT2‐associated deficits suggesting that alterations in thermoregulation were caused by exposure of rats to METH duringdevelopment. These findings suggest METH during development prevents METH‐induced hyperthermia and the consequent METH‐related neurotoxicity. Synapse 2011. © 2011 Wiley‐Liss, Inc.
Using orthogonal pairs of rollers on concave beds (OPRCB) as a base isolation system—part II: application to multi‐story and tall buildings
Authors: Hosseini Mahmood , Soroor Amirhossein 
Published: December 2010

SUMMARYApplication of orthogonal pairs of rollers on concave beds (OPRCB) isolating system to short‐ and mid‐rise buildings is presented in this paper. At first, the analytical formulation of the set of equations, governing the motion of Multi Degree of Freedom (MDOF) systems, isolated by OPRCB isolators, has been developed. Then, some multi‐story regular buildings of shear type have been considered, once on fixed bases and once installed on the OPRCB isolators. Next, some horizontal and vertical accelerograms of both far‐ and near‐fault earthquakes with low‐ to high‐frequency content, particularly those with remarkable peak ground displacement values, have been selected and normalized to three peak ground acceleration levels of 0.15  g, 0.35  g and 0.7  g, and their stronger horizontal component simultaneous with their vertical component have been used for response analysis of the considered buildings. Story drifts and absolute acceleration response histories of isolated buildings have been calculated by using a program, developed in MATLAB environment by using the fourth‐order Runge–Kutta method, considering the geometrically nonlinear behavior of isolators. Maximum relative displacement and story drifts as well as absolute acceleration responses of considered isolated buildings for various earthquakes have been compared with those of corresponding fixed‐base buildings to show the high efficiency of using OPRCB isolators in multi‐story and tall regular buildings. Copyright © 2010 John Wiley & Sons, Ltd.
Electronic musical instrument shoe in consideration of universal design
Authors: Sugaya Satoshi , Kina Robin M. , Matoba Yasushi , Koumura Makoto , Vichai Saechout , Hirai Seiji 
Published: December 2010

AbstractWe developed a new electronic musical instrument shoe called ‘Otokutsu’. It is a shoe to play music with a foot. It can be easily played by anyone in consideration of universal design. It not only flashes but also makes sounds. It is fun and easy for everyone. Furthermore, we developed the special score for Otokutsu. It can be easily played even by beginners or the persons who do not read a score, and it enables the rehabilitation exercises for foot enjoyable. We evaluated it at some elder day‐care centers and elementary schools. We achieved to realize enjoyable and continuable rehabilitation exercises by Otokutsu. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A MAC protocol for cognitive wireless sensor body area networking
Authors: Ali Khaled A. , Sarker Jahangir H. , Mouftah Hussein T. 
Published: December 2010

AbstractIn this paper, a Cognitive Radio Based Medium Access Control (CR‐MAC) protocol for Wireless Sensor Body Area Networks (WSBAN) that utilizes cognitive radio transmission is proposed. In this proposal, the sensor nodes are classified into nodes of life‐critical health information and nodes of non‐critical health information. The CR‐MAC protocol prioritizes the critical packets access to the transmission medium by transmitting them with higher power while transmitting lower priority packets using lower transmission power. At the receiver, a higher priority packet experiences collision only when there are more than one critical packet transmission at the same transmission slot while non critical packets experience collision when there are more than one transmission at the same transmission slot. This protocol is evaluated analytically and through simulation. The obtained results demonstrate a differentiated service system which prioritizes critical traffic access to the transmission medium and increases the critical traffic throughput. Copyright © 2010 John Wiley & Sons, Ltd.