bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permeability changes induced by 130 GHz pulsed radiation on cationic liposomes loaded with carbonic anhydrase
Authors: Ramundo‐Orlando Alfonsina , Gallerano Gian Piero , Stano Pasquale , Doria Andrea , Giovenale Emilio , Messina Giovanni , Cappelli Mauro , D'Arienzo Marco , Spassovsky Ivan 
Published: July 2007

AbstractThe effects of pulsed 130 GHz radiations on lipid membrane permeability were investigated by using cationic liposomes containing dipalmitoyl phosphatidylcholine (DPPC), cholesterol, and stearylamine. Carbonic anhydrase (CA) was loaded inside the liposomes and the substrate p‐nitrophenyl acetate (p‐NPA) added in the bulk aqueous phase. Upon permeation across the lipid bilayer, the trapped CA catalyzes the conversion of the p‐NPA molecules into products. Because the self‐diffusion rate of p‐NPA across intact liposomes is very low the CA reaction rate, expressed as ΔA/min, is used to track membrane permeability changes. The effect of 130 GHz radiation pulse‐modulated at low frequencies of 5, 7, or 10 Hz, and at time‐averaged incident intensity (IAV) up to 17 mW/cm2 was studied at room temperature (22 °C), below the phase transition temperature of DPPC liposomes. At all the tested values of IAV a significant enhancement of the enzyme reaction rate in CA‐loaded liposomes occurred when the pulse repetition rate was 7 Hz. Typically, an increase from ΔA/min = 0.0026 ± 0.0010 (n = 11) to ΔA/min = 0.0045 ± 0.0013 (n = 12) (P < 0.0005) resulted at IAV = 7.7 mW/cm2. The effect of 130 GHz pulse‐modulated at 7 Hz was also observed on cationic liposomes formed with palmitoyloleoyl phosphatidylcholine (POPC), at room temperature (22 °C), above the phase transition temperature of POPC liposomes. Bioelectromagnetics 28:587–598, 2007. © 2007 Wiley‐Liss, Inc.
The evolving concept of tumor microenvironments
Authors: Laconi Ezio 
Published: July 2007

AbstractThe role of the microenvironment in cancer development is being increasingly appreciated. This paper will review data that highlight an emerging distinction between two different entities: the microenvironment that altered/preneoplastic/neoplastic cells find in the tissue where they reside, and the peculiar microenvironment inside the focal lesion (tumor) that these cells contribute to create. While alteration in the tissue environment can contribute to the selective clonal expansion of altered cells to form focal proliferative lesions, the atypical, non‐integrated growth pattern that defines such focal lesions leads to the appearance of what is correctly referred to as the tumor microenvironment. The latter represents a new and unique biological milieu, characterized by hypoxia, acidosis and other biochemical and metabolic alterations, including genetic instability, that can set the stage for tumor progression to occur. Thus, the two microenvironments act in sequence and play complementary roles in the development of overt neoplasia. This distinction has important implications for the understanding of disease pathogenesis and for the management of preneoplastic/neoplastic lesions at various stages of cancer development. BioEssays 29:738–744, 2007. © 2007 Wiley Periodicals, Inc.
Deconstructing digit chondrogenesis
Authors: Montero Juan A. , Hurlé Juan M. 
Published: July 2007

AbstractChondrogenesis is a key process in skeletogenesis since endochondral ossification requires the formation of a cartilaginous template. Knowledge of molecular mechanisms regulating chondrogenesis is extremely valuable not only to understand many human disorders but also in regenerative medicine. Embryonic skeletogenesis is an excellent model to study this mechanism. Most cartilages share the cellular basis underlying chondrogenesis but the high heterogeneity in morphologies of the different skeletal elements appears to be generated by differential participation of a variety of chondrogenic signals. Here we overview the regulatory factors responsible for chondrogenesis concluding that early chondrogenic signals for the digit cartilages differ from those implicated in the formation of other axial and appendicular skeletal components. BioEssays 29:725–737, 2007. © 2007 Wiley Periodicals, Inc.
Eclipsed distribution: A phenomenon of dual targeting of protein and its significance
Authors: Regev‐Rudzki Neta , Pines Ophry 
Published: July 2007

AbstractOne of the surprises from genome sequencing projects is the apparently small number of predicted genes in different eukaryotic cells, particularly human. One possible reason for this ‘shortage’ of genes is multiple distribution of proteins; a single protein is targeted to more than one subcellular compartment and consequently participates in different biochemical pathways and might have completely different functions. Indeed, in recent years, there have been reports on proteins that were found to be localized in cellular compartments other than those initially attributed to them. Furthermore, the phenomenon of highly uneven isoprotein distribution was recently observed and termed ‘eclipsed distribution’. In these cases, the amount of one of the isoproteins, in one of the locations, is significantly minute and its detection by standard biochemical and visualization methods is masked by the presence of the dominant isoprotein. In fact, the minute amounts of eclipsed proteins can be essential. Since detecting eclipsed distribution is difficult, we assume that this phenomenon is probably more common than currently recorded. Hence, developing methods for localization and functional detection of eclipsed proteins is a challenge in cell biology research. Finally, eclipsed distribution may lead to cellular pathologies as has been suggested to occur in human disorders such as Prion diseases and Alzheimer. This review provides a short description of the eclipsed distribution phenomenon followed by an overview of protein distribution mechanisms, examples of eclipsed distribution and experimental approaches for revealing these elusive proteins. BioEssays 29:772–782, 2007. © 2007 Wiley Periodicals, Inc..
Proteoglycans: key partners in bone cell biology
Authors: Lamoureux François , Baud'huin Marc , Duplomb Laurence , Heymann Dominique , Rédini Françoise 
Published: July 2007

AbstractThe diversity of bone proteoglycan (PG) structure and localisation (pericellular, extracellular in the organic bone matrix) reflects a broad spectrum of biological functions within a unique tissue. PGs play important roles in organizing the bone extracellular matrix, taking part in the structuring of the tissue itself as active regulators of collagen fibrillogenesis. PGs also display selective patterns of reactivity with several constituents including cytokines and growth factors, such as transforming growth factor‐β or osteoprotegerin thereby modulating their bio‐availability and biological activity in the bone tissue. In this review, the complex PG composition in bone will be addressed together with the specific role played by PGs (or their GAGs chains) in bone biology, as regulatory molecules for bone resorption and their involvement in bone tumor development. These roles have been determined after modulation of PG expression or mutations in their corresponding genes, which revealed specific roles for these compounds in bone pathologies (e.g. perlecan or glypican‐3 mutations observed respectively in chondrodysplasia or dysmorphic syndrome). Finally, the potential therapeutic interest of PGs is discussed based on recent data, more particularly on bone tumor‐associated osteolysis as these molecules are involved both in bone resorption and tumor development. BioEssays 29:758–771, 2007. © 2007 Wiley Periodicals, Inc.
Putting numbers on the network connections
Authors: Stormo Gary D. , Zhao Yue 
Published: July 2007

AbstractDNA–protein interactions are fundamental to many biological processes, including the regulation of gene expression. Determining the binding affinities of transcription factors (TFs) to different DNA sequences allows the quantitative modeling of transcriptional regulatory networks and has been a significant technical challenge in molecular biology for many years. A recent paper by Maerkl and Quake1 demonstrated the use of microfluidic technology for the analysis of DNA–protein interactions. An array of short DNA sequences was spotted onto a glass slide, which was then covered with a microfluidic device allowing each spot to be within a chamber into which the flow of materials was controlled by valves. By trapping the DNA–protein complexes on the surface and measuring their concentrations microscopically, they could determine the binding affinity to a large number of DNA sequences that were varied systematically. They studied four TFs from the basic helix–loop–helix family of proteins, all of which bind to E‐box sites with the consensus CAnnTG (where “n” can be any base), and showed that variations in affinity for different sites allows each TF to regulate different genes. BioEssays 29:717–721, 2007. © 2007 Wiley Periodicals, Inc.
D‐Mannitol production by resting state whole cell biotransformation of D‐fructose by heterologous mannitol and formate dehydrogenase gene expression in Bacillus megaterium
Authors: Bäumchen Carsten , Roth Andreas H. F. J. , Biedendieck Rebekka , Malten Marco , Follmann Martin , Sahm Hermann , Bringer‐Meyer Stephanie , Jahn Dieter 
Published: July 2007

AbstractAn in vivo system was developed for the biotransformation of D‐fructose into D‐mannitol by the expression of the gene mdh encoding mannitol dehydrogenase (MDH) from Leuconostoc pseudomesenteroides ATCC12291 in Bacillus megaterium. The NADH reduction equivalents necessary for MDH activity were regenerated via the oxidation of formate to carbon dioxide by coexpression of the gene fdh encoding Mycobacterium vaccae N10 formate dehydrogenase (FDH). High‐level protein production of MDH in B. megaterium required the adaptation of the corresponding ribosome binding site. The fdh gene was adapted to B. megaterium codon usage via complete chemical gene synthesis. Recombinant B. megaterium produced up to 10.60 g/L D‐mannitol at the shaking flask scale. Whole cell biotransformation in a fed‐batch bioreactor increased D‐mannitol concentration to 22.00 g/L at a specific productivity of 0.32 g D‐mannitol (gram cell dry weight)–1 h–1 and a Dmannitol yield of 0.91 mol/mol. The nicotinamide adenine dinucleotide (NAD(H)) pool of the B. megaterium producing D‐mannitol remained stable during biotransformation. Intra‐ and extracellular pH adjusted itself to a value of 6.5 and remained constant during the process. Data integration revealed that substrate uptake was the limiting factor of the overall biotransformation. The information obtained identified B. megaterium as a useful production host for D‐mannitol using a resting cell biotransformation approach.
Glucosylation of phenols and phenylalkyl alcohols using cultured plant cells
Authors: Shimoda Kei , Sato Noriaki , Nakajima Nobuyoshi , Hamada Hatsuyuki , Ishihara Kohji , Hamada Hiroki 
Published: July 2007

AbstractCultured plant cells of Eucalyptus perriniana can convert phenol and phenylalkyl alcohols [C6H5(CH2)nOH, n=0–3] into the corresponding β‐D‐glucopyranosides in a good yield. The cells preferentially glucosylated phenylmethanol (n=1, 59% yield) rather than phenol (n=0, 49%), 2‐phenylethanol (n=2, 38%), and 3‐phenylpropan‐1‐ol (n=3, 20%). On the other hand, 2‐, 3‐, and 4‐hydroxyphenylmethanols were also glucosylated to (hydroxymethyl)phenyl β‐D‐glucopyranosides and (hydroxyphenyl)methyl β‐D‐glucopyranosides by cultured E. perriniana cells.
Megan's law and its impact on community re‐entry for sex offenders
Authors: Levenson Jill S. , D'Amora David A. , Hern Andrea L. 
Published: July 2007

AbstractCommunity notification, known as “Megan's Law,” provides the public with information about known sex offenders in an effort to assist parents and potential victims to protect themselves from dangerous predators. The purpose of this study was to explore the impact of community notification on the lives of registered sex offenders. Two hundred and thirty‐nine sex offenders in Connecticut and Indiana were surveyed. The negative consequences that occurred with the greatest frequency included job loss, threats and harassment, property damage, and suffering of household members. A minority of sex offenders reported housing disruption or physical violence following community notification. The majority experienced psychosocial distress such as depression, shame, and hopelessness. Recommendations are made for community notification policies that rely on empirically derived risk assessment classification systems in order to better inform the public about sex offenders' danger while minimizing the obstacles that interfere with successful community reintegration. Copyright © 2007 John Wiley & Sons, Ltd.
Power in community psychology research and practice
Authors: Fisher Adrian T. , Sonn Christopher C. 
Published: July 2007

AbstractWhile power underpins so much of community psychology, it is not usually the focus of research or practice. Even empowerment approaches lack clear definition of the power against which they are operating. This article introduces a model developed at Peabody College, Vanderbilt University, to understand various power dimensions and levels at which it can have impacts. Such a multifaceted model has facilitated the series of articles that follow – re‐analysing the authors' work with power as the core element in the analyses, and understanding the different levels of analysis, sources of power, and ways in which power imbalances can be redressed. Copyright © 2007 John Wiley & Sons, Ltd.
Interrogating power: the case of arts and mental health in community projects
Authors: Lawthom Rebecca , Sixsmith Judith , Kagan Carolyn 
Published: July 2007

AbstractIn this paper, we use the multi‐dimensional model of power to interrogate arts and mental health community based projects. Using data retrospectively gathered during a series of participative evaluations, we re‐analyse the data focusing on the ways in which power is located and negotiated across levels of analysis and multiple ecological domains. Evidence from the evaluations is richly presented illustrating power at the micro, meso and macro level. Whilst the model offers a rich reading of power, it is difficult to operationalize historically. Moreover, the static nature of the model fails to adequately capture the multiplicity of sometimes polar positions adopted. Engaging in a particular framework of community psychology, we argue that this project may be seen as part of a wider prefigurative action research agenda. Copyright © 2007 John Wiley & Sons, Ltd.
Child poverty and government policy: the contesting of symbolic power in newspaper constructions of families in need
Authors: Barnett Alison , Hodgetts Darrin , Nikora Linda , Chamberlain Kerry , Karapu Rolinda 
Published: July 2007

AbstractNews media play a central role in processes of symbolic power through which social issues are defined and solutions legitimized. This paper explores the role of newspaper coverage in the public construction of the New Zealand Government'sWorking for Familiespackage designed to address child poverty. This package was criticized publicly by the Child Poverty Action Group (CPAG) for targeting financial support to working families and neglecting families who derive their income from state benefits. We document the resulting news controversy through analyses of press releases from Government and CPAG, the accounts of journalists and representatives of CPAG, news reports and four focus group discussions with beneficiary parents. We propose that psychologists engage more fully with processes of symbolic power currently shaping public constructions of poverty and policy responses. Copyright © 2007 John Wiley & Sons, Ltd.
Macroscopic thrombus formation on angioplasty equipment following antithrombin therapy with enoxaparin
Authors: Dana A. , Nguyen C.M. , Cloutier S. , Barbeau G.R. 
Published: July 2007

AbstractIncreasing evidence suggests that treatment with the low molecular weight heparin enoxaparin during percutaneous coronary intervention (PCI) is safe and effective. We evaluated the incidence and consequences of periprocedural macroscopic thrombus formation on PCI equipment following antithrombin therapy with enoxaparin. Between April 2003 and December 2004, all patients undergoing cardiac catheterization following antithrombin therapy with enoxaparin were evaluated. All patients had blood sampled at the onset of procedure for subsequent measurement of anti‐factor‐Xa levels. Of the 4,504 patients who underwent PCI during this period, in 122 (3%) the procedure was performed within 8 hr of treatment with subcutaneous enoxaparin and no additional unfractionated heparin (UFH) was used periprocedurally. Of these, macroscopic thrombus was observed on PCI equipment in 6 patients (5%) necessitating withdrawal of all catheters and wires. All patients had therapeutic anti‐factor‐Xa levels at the time of PCI, and had been treated with double antiplatelet therapy with aspirin and clopidogrel. No periprocedural thrombus was observed in 356 patients who were ≫12 hr of the last dose of enoxaparin and received UFH at the time of PCI. Following observation of thrombus, additional anticoagulation with UFH resulted in significant epistaxis in one patient. In another patient, the procedure was complicated by distal coronary embolization. Percutaneous coronary intervention following antithrombin therapy with enoxaparin is associated with a 5% incidence of macroscopic thrombus formation on PCI equipment. The necessity for subsequent exchange of all equipment and/or the need for additional anticoagulation may have disastrous consequences for the patient. Our findings suggest that the safety of antithrombin therapy with low molecular weight heparin during PCI requires further evaluation. © 2007 Wiley‐Liss, Inc.
Percutaneous closure of an iatrogenic ventricular septal defect following mechanical aortic valve replacement using the transseptal technique
Authors: Klein Andrew J. , Garcia Joel A. , Carroll John D. 
Published: July 2007

AbstractIatrogenic ventricular septal defects (VSDs) following aortic valve replacement are relatively uncommon and are challenging to close percutaneously given their typical proximity to the prosthetic valve. We describe the successful percutaneous closure of an iatrogenic VSD in a patient with a recent mechanical AVR using the transseptal approach. © 2007 Wiley‐Liss, Inc.
The sphere in a uniform RF field—Revisited
Authors: Bidinosti C.P. , Chapple E.M. , Hayden M.E. 
Published: July 2007

AbstractWe consider eddy current generation in weakly conducting spheres as a means to characterize RF power dissipation over the frequency range 0.1–1.2 MHz, which is relevant to MRI in very low magnetic fields. We provide a complete, yet simple, theoretical analysis of the homogeneous sphere in a uniform RF field and summarize expressions for the current density, power dissipation, and magnetic field for the limiting case of the nonmagnetic conducting sphere. Experiments are performed on spherical saline phantoms using a whole‐body B1‐coil as the RF field source. Changes in the quality factor and magnetic field profile of the coil are measured and used to extract a value for conductivity of the saline solution. This conductivity is known independently from the NaCl concentration in the phantom. Excellent agreement between the two values confirms the theoretical analysis. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 191–202, 2007
Comparison of three algorithms for solving linearized systems of parallel excitation RF waveform design equations: Experiments on an eight‐channel system at 3 Tesla
Authors: Zelinski Adam C. , Wald Lawrence L. , Setsompop Kawin , Alagappan Vijayanand , Gagoski Borjan A. , Goyal Vivek K , Hebrank Franz , Fontius Ulrich , Schmitt Franz , Adalsteinsson Elfar 
Published: July 2007

AbstractThree algorithms for solving linearized systems of RF waveform design equations for calculating accelerated spatially‐tailored excitations on parallel excitation MRI systems are presented. Their artifact levels, computational speed, and RF peak and root‐mean‐square (RMS) voltages are analyzed. An SVD‐based inversion method is compared with conjugate gradient least squares (CGLS) and least squares QR (LSQR), two iterative algorithms designed to solve large linear systems. The excitation pulses calculated using these methods are used in both Bloch simulations and imaging experiments on an actual eight‐channel parallel excitation coil array implemented on a 3T human scanner. Specifically, RF waveforms are designed for accelerated 2D spiral k‐space trajectories to produce a variety of 2D target excitations and for a 3D spokes trajectory to produce a uniform thin‐slice excitation. Overall, these experiments show that waveforms designed using LSQR and CGLS have significantly lower peak and RMS waveform voltages and produce excitations with fewer artifacts than those generated by the SVD‐based method. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 176–190, 2007
SAR simulation and the effect of mode coupling in a birdcage resonator
Authors: Reza S. , Vijayakumar S. , Limkeman M. , Huang F. , Saylor C. 
Published: July 2007

AbstractThe issues related to the simulation of specific absorption rate (SAR) in a high frequency magnetic resonance coil are discussed in this work. Using simulation results, it is shown that the effect of the nonimaging modes on SAR can be substantial and thus must be taken into account. Also a technique for the estimation of SAR for coils with complicated geometry is presented. The presented technique will be useful in cases where the conventional finite difference time domain simulation is not practical because of large memory requirement and/or excessively long computation time. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 133–139, 2007
Task‐performing dynamics in irregular, biomimetic networks
Authors: Messinger Susanna M. , Mott Keith A. , Peak David 
Published: July 2007

AbstractUnderstanding self‐organized collective dynamics—especially in sparsely connected, noisy, and imperfect networks—has important implications for designing and optimizing task‐performing technological systems as well as for deciphering biological structures and functions. We note that stomatal arrays on plant leaves might provide an ideal example of task‐performance in this context. Guided by observations of stomatal networks, we examined a simple model of task‐performing, collective dynamics that included state noise, spatial rule heterogeneity, dynamic modules, and network rewiring. Our results indicate that task‐performance in such networks can actually be enhanced by various kinds of spatial and temporal irregularity. © 2007 Wiley Periodicals, Inc. Complexity 12: 14–21, 2007
What is the complexity of a distributed computing system?
Authors: Ranganathan Anand , Campbell Roy H. 
Published: July 2007

AbstractDistributed computing systems are becoming bigger and more complex. Although the complexity of large‐scale distributed systems has been acknowledged to be an important challenge, there has not been much work in defining or measuring system complexity. Thus, today, it is difficult to compare the complexities of different systems, or to state that one system is easier to program, to manage, or to use than another. In this article, we try to understand the factors that cause computing systems to appear very complex to people. We define different aspects of system complexity and propose metrics for measuring these aspects. We also show how these aspects affect different kinds of people—viz. developers, administrators, and end‐users. On the basis of the aspects and metrics of complexity that we identify, we propose general guidelines that can help reduce the complexity of systems. © 2007 Wiley Periodicals, Inc. Complexity 12: 37–45, 2007