bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microtubules: A dynamic target in cancer therapy
Authors: Pasquier Eddy , Kavallaris Maria 
Published: April 2008

AbstractThe tubulin/microtubule system is an important target for anticancer therapy. Two of the most clinically valuable groups of these agents are the vinca alkaloids and taxanes. In recent years, new tubulin‐binding agents have been under preclinical or clinical development. One of these classes of agents, epothilones, has shown great promise in phase III clinical trials. What all these agents share in common, is that they bind to β‐tubulin and disrupt microtubule function during mitosis which in turn leads to mitotic arrest and cell death. In addition, these agents can inhibit angiogenesis. Not withstanding their effectiveness, drug resistance can pose a major clinical problem. This review provides an overview of the mechanisms mediating resistance to tubulin‐binding agents related to the cellular target and discusses strategies to overcome this important clinical problem. © 2008 IUBMB IUBMB Life, 60(3): 165–170, 2008
The role of PAS kinase in regulating energy metabolism
Authors: Hao Huai‐Xiang , Rutter Jared 
Published: April 2008

AbstractMetabolic disorders, such as diabetes and obesity, are fundamentally caused by cellular energy imbalance and dysregulation. Therefore, understanding the regulation of cellular fuel and energy metabolism is of great importance to develop effective therapies for metabolic disease. The cellular nutrient and energy sensors, AMPK and TOR, play a key role in maintaining cellular energy homeostasis. Like AMPK and TOR, PAS kinase (PASK) is also a nutrient responsive protein kinase. In yeast, PAS kinase phosphorylates the enzyme Ugp1 and thereby shifts glucose partitioning toward cell wall glucan synthesis at the expense of glycogen synthesis. Consistent with this function, yeast PAS kinase is activated by both cell integrity stress and growth in non‐fermentative carbon sources. PASK is also important for proper regulation of glucose metabolism in mammals at both the hormonal and cellular level. In cultured pancreatic β‐cells, PASK is activated by elevated glucose concentrations and is required for glucose‐stimulated transcription of the insulin gene. PASK knockdown in cultured myoblasts causes increased glucose oxidation and elevated cellular ATP levels. Mice lacking PASK exhibit increased metabolic rate and resistance to diet‐induced obesity. Interestingly, PGC‐1 expression and AMPK and TOR activity were not affected in PASK deficient mice, suggesting PASK may exert its metabolic effects through a new mechanism. We propose that PASK plays a significant role in nutrient sensing, metabolic regulation, and energy homeostasis, and is a potential therapeutic target for metabolic disease. © 2008 IUBMB IUBMB Life, 60(4): 204–209, 2008
SWAP‐70 is important for invasive phenotypes of mouse embryo fibroblasts transformed by v‐Src
Authors: Murugan Avaniyapuram Kannan , Ihara Sayoko , Tokuda Emi , Uematsu Kimio , Tsuchida Nobuo , Fukui Yasuhisa 
Published: April 2008

AbstractSWAP‐70 is a protein involved in actin rearrangement, especially in membrane ruffling. Mouse embryo fibroblasts (MEFs) deficient in SWAP‐70 show impaired membrane ruffling and fail to grow in soft agar after transformation by v‐Src. Here, we show that v‐Src transformed MEFs expressing SWAP‐70 are highly invasive. MEFs expressing SWAP‐70 or v‐Src alone were far less invasive, suggesting that both proteins were required for the cells to be invasive. Expression of both SWAP‐70 and v‐Src induced constant membrane ruffling, which may cause vigorous cell movement, probably required for invasiveness of the cells. Expression of v‐Src alone morphologically transformed MEFs but formed lamellipodia rather than membrane ruffles, suggesting less aggressive nature of the cells compared with those expressing both SWAP‐70 and v‐Src. These results suggest that v‐Src and SWAP‐70 act synergistically in the invasion activity of MEFs. © 2008 IUBMB IUBMB Life, 60(4): 236–240, 2008
Steroid and thyroid hormone receptors in mitochondria
Authors: Psarra Anna‐Maria G. , Sekeris Constantine E. 
Published: April 2008

AbstractReceptors for glucocorticoids, estrogens, androgens, and thyroid hormones have been detected in mitochondria of various cell types by Western blotting, immunofluorescence labeling, confocal microscopy, and immunogold electron microscopy. A role of these receptors in mitochondrial transcription, OXPHOS biosynthesis, and apoptosis is now being revealed. Steroid and thyroid hormones regulate energy production, inducing nuclear and mitochondrial OXPHOS genes by way of cognate receptors. In addition to the action of the nuclearly localized receptors on nuclear OXPHOS gene transcription, a parallel direct action of the mitochondrially localized receptors on mitochondrial transcription has been demonstrated. The coordination of transcription activation in nuclei and mitochondria by the respective receptors is in part realized by their binding to common trans acting elements in the two genomes. Recent evidence points to a role of the mitochondrial receptors in cell survival and apoptosis, exerted by genomic and nongenomic mechanisms. The identification of additional receptors of the superfamily of nuclear receptors and of other nuclear transcription factors in mitochondria increases their arsenal of regulatory molecules and further underlines the central role of these organelles in the integration of growth, metabolic, and cell survival signals. © 2008 IUBMB IUBMB Life, 60(4): 210–223, 2008
The Poisson‐Boltzmann model for tRNA: Assessment of the calculation set‐up and ionic concentration cutoff
Authors: Gruziel Magdalena , Grochowski Pawel , Trylska Joanna 
Published: April 2008

AbstractUsing tRNA molecule as an example, we evaluate the applicability of the Poisson‐Boltzmann model to highly charged systems such as nucleic acids. Particularly, we describe the effect of explicit crystallographic divalent ions and water molecules, ionic strength of the solvent, and the linear approximation to the Poisson‐Boltzmann equation on the electrostatic potential and electrostatic free energy. We calculate and compare typical similarity indices and measures, such as Hodgkin index and root mean square deviation. Finally, we introduce a modification to the nonlinear Poisson‐Boltzmann equation, which accounts in a simple way for the finite size of mobile ions, by applying a cutoff in the concentration formula for ionic distribution at regions of high electrostatic potentials. We test the influence of this ionic concentration cutoff on the electrostatic properties of tRNA. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
Inclusion of the quadrupole moment when describing polarization. The effect of the dipole‐quadrupole polarizability
Authors: Holt Asbjørn , Karlström Gunnar 
Published: April 2008

AbstractA method to compute distributed dipole–quadrupole polarizabilities is suggested. The method is based on numerical differentiation of distributed quadrupole moments, using finite field perturbation calculations. It is tested using two different multicenter multipole expansions, and compared with results using polarizabilities obtained via the uncoupled Hartree–Fock approximation. The accuracy of these dipole–quadrupole polarizabilities are tested for different molecules and basis sets, by comparing the induced electrostatic potential of the Hartree–Fock density with the induced electrostatic potential of the polarization models. This is done by perturbing the molecules with an external homogeneous field and with an external dipole. It is found that inclusion of the dipole–quadrupole polarizability significantly improves the accuracy of the response of the molecule to these external perturbations. This suggests that inclusion of higher‐order induced moments can be of importance when improving the description of intermolecular interactions using force fields. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Treatment of methanol vapours in biofilters packed with inert materials
Authors: Avalos Ramirez Antonio , Bénard Sandrine , Giroir‐Fendler Anne , Jones J Peter , Heitz Michèle 
Published: April 2008

AbstractBACKGROUND: Methanol is a major pollutant emitted in Canada. Methanol is toxic to humans and it is associated with environmental problems such as smog generation. Biofiltration is a treatment method of considerable interest for controlling methanol emissions, because of its characteristics: no production of hazardous wastes, low energy consumption and low operating costs. The present study analyzed the effects of porous and non‐porous packing materials, the nitrogen concentration in nutrient solution and the methanol inlet load on biofilter performance and biofilm characteristics.RESULTS: The biofilter packed with porous material presented a removal efficiency up to 95%, which was higher than the 35% removal efficiency with the non‐porous material. Inlet load (IL) influenced the biomass and carbon dioxide production rates. The critical inlet load (ILcrit) occurred at 80 g m−3 h−1. The cellular densities of methylotrophs and non‐methylotrophs were affected by all operating variables examined.CONCLUSION: Biofiltration can be applied for controlling methanol emissions with high removal efficiency. The cellular density of methylotrophs is correlated with the performance of the biofilter. Copyright © 2008 Society of Chemical Industry
Larval morphology of the brooding clam Lasaea adansonii (Gmelin, 1791) (Bivalvia, Heterodonta, Galeommatoidea)
Authors: Altnöder Andreas , Haszprunar Gerhard 
Published: April 2008

AbstractThe strongly modified mode of development of the small and brooding galeommatoid bivalve Lasaea adansonii (Gmelin, 1791) [syn. Lasaea rubra (Montagu, 1803)] has been studied by means of transmission and scanning electron microscopy and by fluorescent staining of the muscular system and of two neurotracers, FMRFamide and serotonin. In addition, two developmental stages were visualized using computer‐aided 3D‐reconstruction. All larval stages of L. adansonii lack ciliary rings. The apical organ appears invaginated: the base of the duct contacts the cerebral ganglia and opens on the preoral region. Larval protonephridia are lacking. The adult kidneys develop independently of the pericardial cavity and contain a protonephridial part that enables excretory function until the pericardium is formed. The larval muscular system is composed of smooth muscle fibers; striated fibers are lacking. Posteriorly and immediately below the ligament, a paired cell of unknown function is present that contains serotonin and FMRFamide. In summary, L. adansonii exhibits the direct mode of development. Only few truly larval structures (e.g., the modified apical organ) are elaborated. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Surface topology and structural integrity of the Theromyzon tessulatum (Annelida: Hirudinea: Glossiphoniidae) cocoon
Authors: Coleman Jon'elle , Marotta Roberto , Shain Daniel H. 
Published: April 2008

AbstractCocoons secreted by the aquatic leech Theromyzon tessulatum comprise a tubular, membranous ovoid, sealed at each end by a glue‐like substance, called an operculum. Scanning electron microscopy showed surface features of the T. tessulatum cocoon that included a circuitous bulge, cups that conformed to the shape of embryos, relief folds that radiated from opercula, and asymmetric distributions of protuberances on the upper aspect of the cocoon surface. The structural integrity of the T. tessulatum cocoon was assessed after exposure to a variety of denaturing conditions (e.g., extreme heat, detergents, acids). Although both the fibrous cocoon membrane and opercula were strikingly resilient, the membrane/operculum boundary appeared to be the weakest structural component of the cocoon, consistent with its functional role as an escape hatch for juvenile leeches. The operculum itself was more sensitive to denaturation than the cocoon membrane, and thus was probably the source of a major protein component isolated from the T. tessulatum cocoon (i.e., Tcp; Theromyzon cocoon protein). J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Effects of estrogen on basal forebrain cholinergic neurons and spatial learning
Authors: Ping Sophie E. , Trieu Jennifer , Wlodek Mary E. , Barrett Graham L. 
Published: April 2008

AbstractEstrogen receptors are expressed in several areas of the brain associated with cognition, including the basal forebrain cholinergic nuclei, and numerous reports have described improvements in memory in response to estrogen supplementation. The relationship between estrogen's effects on the basal cholinergic system and improvements in cognitive function, however, are obscure. We therefore undertook a study to determine the effects of estrogen on several parameters of the cholinergic system in ovariectomized rats and measured the concomitant effects on performance in the Barnes maze, a test of spatial memory. Six weeks of estradiol treatment caused an increase in choline acetyltransferase activity throughout the projection fields of the basal forebrain, including the hippocampal formation (14%), olfactory bulb (30%), and cerebral cortex (35%). Estrogen treatment also caused an increase in cell soma size of cholinergic neurons in the horizontal diagonal limb of the band of Broca and in the basal nucleus of Meynert. There was no change in the number of neurons positive for p75NTR, nor in the level of p75NTR expression per neuron. Barnes maze performance was markedly improved after estradiol treatment, reinforcing the view that estrogen has beneficial cognitive effects, particularly on spatial memory. The beneficial cognitive effect was likely mediated in part by stimulation of the basal forebrain cholinergic system, especially in its neocortical projection, but was not associated with changes in the level of p75NTR expression. © 2008 Wiley‐Liss, Inc.
Basis for the new challenges of growing broccoli for health in hydroponics
Authors: Moreno Diego A , López‐Berenguer Carmen , Martínez‐Ballesta M. Carmen , Carvajal Micaela , García‐Viguera Cristina 
Published: April 2008

AbstractBACKGROUND: Variations in the contents of phytochemicals with biological activity in broccoli could originate as a result of genetic and environmental factors. An understanding of the effects of growth conditions on the bioactive compounds in broccoli is essential for improving its quality and nutritive value. Using salinity (40 mmol L−1 NaCl), and foliar sprayed compounds (methionine, tryptophan and chitosan) as different stress conditions, broccoli developed in soilless culture in the greenhouse was analysed for biologically active phytochemicals (glucosinolates, caffeoyl‐quinic, ferulic and sinapic derivatives and vitamin C).RESULTS: The application of elicitors during head formation could be beneficial for the enrichment in phytochemicals in broccoli. Management practices for increasing a given phytochemical (e.g., glucoraphanin or glucobrassicin) may be related to a decreased level of natural antioxidants (hydroxycinnamic acids). Growing broccoli hydroponically in the greenhouse in winter (Mediterranean climate) needs the supporting treatment of abiotic stress during development (i.e., NaCl, elicitors).CONCLUSION: The use of hydroponic growth conditions for broccoli and the application of stress factors (elicitors) at head induction and during development may serve the purpose of enhancing its nutritional quality to deliver a health‐promoting food. Copyright © 2008 Society of Chemical Industry
Local perceptions and regional climate trends on the Central Plateau of Burkina Faso
Authors: West C. T. , Roncoli C. , Ouattara F. 
Published: April 2008

AbstractDue to devastating droughts in the 1970s and 1980s, climatic and environmental change in the West African Sahel has attracted a great deal of scientific research. While many of these studies documented a long‐term trend of declining rainfall, analyses conducted in the last few years suggest that a ‘recovery’ is underway. Drawing on ethnographic interviews, focus groups, and participant observation in two Provinces of the Central Plateau of Burkina Faso, we elicited local perspectives on these rainfall trends from the people who are most directly affected, namely local farmers. Fieldwork revealed that farmers in the research sites perceive that both overall seasonal rainfall and the number of ‘big rains’ during the rainy season have decreased over the last 30 years. We then tested these perceptions against rainfall records from nearby meteorological stations and found them to be corroborated. This paper illustrates how farmers of the Central Plateau now view drought as ‘normal’, having incorporated drought‐mitigation adaptations into their agricultural systems. Our case study highlights the need for ground truthing scientific analyses and assessing livelihood implications at the local level. It also advocates for sustained institutional support for rural communities, to increase their ability to adapt to climate change. Copyright © 2008 John Wiley & Sons, Ltd.
Genipin‐Modified Silk‐Fibroin Nanometric Nets
Authors: Silva Simone S. , Maniglio Devid , Motta Antonella , Mano João F. , Reis Rui L. , Migliaresi Claudio 
Published: April 2008

AbstractNanometric silk‐fibroin nets were fabricated by electrospinning from regenerated Bombyx mori silk‐fibroin (SF)/formic acid solutions with the addition of genipin (GE), 2, 15 and 24 h after the solution preparation. After spinning, the pure fibroin nanofibers were water soluble and needed a further stabilization process, whereas the reaction of fibroin with genipin resulted in water‐insoluble fibroin nets due to conformational changes induced in the fibroin by the genipin. SFGE nanofibers presented diameters ranging from 140 to 590 nm and were generally thinner than pure SF nanofibers. The secondary structure of SF into SFGE nanofibers showed the presence of a β‐sheet conformation together with β‐turn intermediates (turns and bends). The approach described in this paper provides an alternative method of designing SF nanofibers that are already water insoluble, without any stability post‐treatment needed.magnified image
Tri‐band compact antenna array for MIMO user mobile terminals at GSM 1800 and WLAN bands
Authors: Gómez‐Calero Carlos , González Luis , Martínez Ramón 
Published: April 2008

AbstractMultiple‐Input Multiple‐Output (MIMO) systems have been widely studied in recent years as a solution to improve the radio link reliability. To introduce MIMO in mobile communications, it is necessary to design antennas with differential features to introduce multiple elements in the space reserved for the antenna, such as the type of element or array configuration. In this article, a 2 × 2 MIMO system has been considered according to the next‐generation WLAN (802.11n) frequencies band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1914–1918, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23472
A novel compact microstrip bandpass filter using folded stepped impedance resonators
Authors: Yang Tao , Xu Ruimin , Xia Lei , Guo Yunchuan 
Published: April 2008

AbstractA folded quarter‐wavelength stepped impedance resonator (SIR) is proposed with a largely reduced size. A bandpass filter with center frequency of 1.85 GHz using the SIRs is designed, fabricated, and measured. This compact filter covers an area less than 10 mm × 10 mm, which makes it suitable for compact and high‐performance microwave circuit applications. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1864–1867, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23476
The effect of FET soft turn‐on on a Doherty amplifier
Authors: Smith Karla J. I. , Eccleston Kimberley W. , Gough Peter T. , Mann Stephen I. 
Published: April 2008

AbstractA Doherty amplifier's theoretical gain and efficiency characteristics significantly exceed those achieved by practical simulations and implementations. Analysis and simulation demonstrates that the FET gate voltage to drain current transfer characteristic has a significant detrimental effect on these characteristics, indicating it is the major factor in the difference between ideal and practical results. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1861–1864, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23477
ADI‐FDTD method perturbed by the second order cross derivative terms
Authors: Kong Ki‐Bok , Kim Jong‐Sung , Park Seong‐Ook 
Published: April 2008

AbstractA two‐step FDTD method as a compromise of conditional stability and reduced splitting error is formulated and its numerical stability is investigated. It is the perturbed form to the ADI‐FDTD method by the addition of second order cross derivative term. It is validated from the comparison of numerical anisotropy and numerical error over the ADI‐FDTD that numerical performances can be improved by controlling the perturbed term within the stable region of the cross derivative term. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1822–1826, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23479
New perturbation technique to generate split modes in electromagnetically coupled notch filters using different ring resonators
Authors: Hari Krishna J. V. S , Karekar R. N , Aiyer R. C 
Published: April 2008

AbstractA new method for generating split modes in ring resonators, used as notch filters with three geometries (square, triangular, and circular), is introduced by varying the feed position of electromagnetically coupled feed line. The resonators are fabricated (all at 2.4 GHz nominally) on TMM4 (εr = 4.5, h = 0.762 mm) substrates and coupled electromagnetically to a 50 Ω microstrip feed line on separate TMM4 substrate. Only the latter has ground plane under it. The offset distance between the center of feed line and center of resonator is varied and changes in the resonant (notch) frequency, rejection (S21) of single and split modes are recorded at each offset position for all resonators. Experimental results are found to agree with simulated results to a greater degree for square and lesser for other two geometries. Frequency variations have much more disagreements. The angle of crossing between feed line and ring edges appears to be a critical factor. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1747–1752, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23483
Design of ultra wideband microstrip 180 degree phase shifter
Authors: Eldek Abdelnasser A. 
Published: April 2008

AbstractA Ultra Wideband microstrip 180 degree phase shifter is presented. It is obtained by a novel design of Microstrip‐to‐Coplanar Waveguide (CPW)‐to‐Microstrip transition. Via holes are used to transfer the current from the top to the bottom substrate layer and vice versa. The presented phase shifter is operating in a wide bandwidth between 5.5 and 17.2 GHz, with low insertion loss and reflection coefficients. This phase shifter can be used in phased arrays and power combiners. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1841–1844, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23487
Criteria for negative refraction in active and passive media
Authors: Kinsler P. , McCall M. W. 
Published: April 2008

AbstractWe review three commonly used conditions that characterize negative refraction in isotropic dielectric‐magnetic materials. We show that while all the different conditions are equivalent for passive media, they are distinct for different types of active media. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1804–1807, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23489