bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ab initio parametrized MM3 force field for the metal‐organic framework MOF‐5
Authors: Tafipolsky Maxim , Amirjalayer Saeed , Schmid Rochus 
Published: February 2007

AbstractA new valence force field has been developed and validated for a particular class of coordination polymers known as nanoporous metal‐organic frameworks (MOFs), introduced recently by the group of Yaghi. The experimental, structural, and spectroscopic data in combination with density functional theory calculations on several model systems were used to parametrize the bonded terms of the force field, which explicitly treats the metal–oxygen interactions as partially covalent as well as distinguishes different types of oxygens in the framework. Both the experimental crystal structure of MOF‐5 and vibrational infrared spectrum are reproduced reasonably well. The proposed force field is believed to be useful in atomistic simulations of adsorption/diffusion of guest molecules inside the flexible pores of this important class of MOF materials. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Hic‐5 contributes to epithelial‐mesenchymal transformation through a RhoA/ROCK‐dependent pathway
Authors: Tumbarello David A. , Turner Christopher E. 
Published: February 2007

AbstractEpithelial‐mesenchymal transformation (EMT) in response to TGFβ1 is a coordinated process of tissue morphogenesis that occurs during embryonic development as well as during certain pathologic events including kidney tubulointerstitial fibrosis. It is characterized by the disassembly of cell–cell junctions and dramatic alterations in the actin cytoskeleton that facilitates cell–matrix adhesion and stimulates migration. The focal adhesion adapter protein, Hic‐5, has previously been reported to be upregulated during TGFβ1‐induced EMT in mouse mammary epithelial cells and the current study recapitulates this result in both mouse kidney proximal tubule epithelial, MCT, cells and human mammary epithelial, MCF10A, cells. To evaluate a causative role for Hic‐5 in EMT, Hic‐5 RNA interference (siRNA) was used to prevent Hic‐5 expression in response to TGFβ1 stimulation and was shown to suppress cell migration and actin stress fiber formation. It also resulted in the retention of a robust epithelial cell morphology characterized by elevated E‐cadherin protein expression and well‐organized adherens junctions. In addition, Hic‐5 siRNA treatment led to the suppression of TGFβ1 induction of RhoA activation. In contrast, forced expression of Hic‐5 led to the formation of ROCK‐dependent actin stress fibers. Furthermore, the induction of Hic‐5 expression in response to TGFβ1 was shown to be a RhoA/ROCK I‐dependent process. Together, these data implicate Hic‐5 as a key regulator of EMT and suggest that RhoA stimulated Hic‐5 expression in response to TGFβ1 may be functioning in a feed forward mechanism whereby Hic‐5 maintains the mesenchymal phenotype through sustained RhoA activation and signaling. J. Cell. Physiol. 211: 736–747, 2007. © 2007 Wiley‐Liss, Inc.
Deterioration of iron archaeological artefacts: micro‐Raman investigation on Cl‐containing corrosion products
Authors: Réguer Solenn , Neff Delphine , Bellot‐Gurlet Ludovic , Dillmann Philippe 
Published: February 2007

AbstractDeterioration after excavation of archaeological iron artefacts buried in soil is often associated with the presence of chlorinated phases in corrosion products, leading to serious problems for conservation of metallic objects of cultural heritage. Therefore, in order to better understand the corrosion process related to the presence of chlorine, some high‐resolution techniques of material characterisation are implemented. The analyses are realised on cross sections of corroded iron objects excavated from archaeological sites dated from the 12th to the 16th century A.D. Cl‐containing phases appear even when the Cl level in the water is low. In addition to the common oxy‐hydroxide‐containing chloride, akaganeite (β–FeOOH) often mentioned in the literature, a ferrous hydroxychloride β–Fe2(OH)3Cl was also found in the corrosion layers. Moreover, part of the study is based on the preparation and desalinisation of pure akaganeite powder in order to characterise the influence of the chloride content on its crystalline structure as characterised by Raman spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes
Authors: Graupner R. 
Published: February 2007

AbstractRaman spectroscopy is one of the most extensively employed methods for the characterization of carbon nanotubes. In this review article, an overview about Raman spectroscopy as a tool for the characterization of functionalized single‐walled carbon nanotubes (SWCNTs) is given. First, the relevant Raman modes in SWCNTs are introduced. Then, in a phenomenological approach, the effects that are observed for the individual modes in the Raman spectra are compiled and discussed. It is shown that special care has to be taken in order to separate the effects of functionalization, which are specific to a subset of the SWCNTs (metallic/semiconducting or diameter dependent), from changes in sample morphology or doping effects. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of common bean enrichment on nutritional quality of tortillas produced from nixtamalized regular and quality protein maize flours
Authors: Mora‐Avilés Alejandra , Lemus‐Flores Bibiana , Miranda‐López Rita , Hernández‐López David , Pons‐Hernández José L , Acosta‐Gallegos Jorge A , Guzmán‐Maldonado Salvador H 
Published: February 2007

AbstractIn Mexico the tortilla is most commonly eaten in the form of ‘taco’; this is normally accompanied with other food, in particular the common bean. Tortillas made of quality protein maize (QPM) fortified with common bean might be a strategy to improve their protein quality. In this study, amino acids and mineral changes that occur during nixtamalization and the chemical and nutritional characteristics of regular, commercial and QPM tortilla–bean combination were assessed. After nixtamalization, protein from QPM nixtamalized maize flour was reduced from 8.1% to 7.2% (w/w). Tryptophan was also reduced from 12.1 to 11.1 g kg−1 protein. QPM maize retained a higher amount (P < 0.05) of calcium (3180 mg kg−1) compared to regular maize (1820 mg kg−1). When nixtamalized maize flour of regular maize and commercial tortilla were combined with beans, protein content increased. The tryptophan and lysine contents in these tortillas were increased (P > 0.05) also, but were significantly lower (P > 0.05) than in tortilla made with QPM maize fortified with bean (22.7 and 69.9 g kg−1 protein, respectively). Mineral contents increased in tortilla–bean combination. The QPM and tortilla fortified with bean gave an improvement in protein quality and could contribute significantly towards human nutrition, especially in countries like Mexico where maize and beans are important components of the diet. Copyright © 2007 Society of Chemical Industry
Visible‐spectroscopy study of the low dimensional (C2H5NH3)2CuCl4 compound in the region of its low temperature phase transitions
Authors: Kapustianyk V. , Rudyk V. , Partyka M. 
Published: February 2007

AbstractOn the basis of absorption spectroscopy data the temperature evolution of Cu2+ ion environment in the layered compound (C2H5NH3)2CuCl4 was studied within the temperature range of 4.5–310 K. For the detailed analysis of the experimental data the specially created program package Crys Tool 1.0 based on the quantum mechanical models first of all on the model of normalised spherical harmonics (NSH) was used. It has been found that the crystal structure in the low temperature phases contains tetragonally distorted octahedral metal–halogen complexes. The parameters of crystal field, normalised spherical harmonics, angular overlap model as well as the metal–halogen distances show anomalous behaviour at the points of phase transitions: Tc = 10 K and T4 = 232 K (for heating). The changes of these parameters observed around T5 = 65 K also may be related to previously unknown phase transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ka‐band link optimization with rate adaptation for Mars and lunar communications
Authors: Sun Jun , Gao Jay , Shambayati Shervin , Modiano Eytan 
Published: February 2007

AbstractOn‐going development of Ka‐band capability for the Deep Space Networks (DSN) will radically increase the bandwidth available to support advanced mission concepts envisioned for future robotic as well as human exploration of Mars and beyond. While Ka‐band links can operate at much higher data rate than X‐band, they are much more susceptible to fluctuating weather conditions and manifest a significant trade‐off between throughput and availability. If the operating point is fixed, the maximum average throughput for deep space Ka‐band link is achieved at about 80% availability, i.e. weather‐related outages will occur about 20% of the time. Low availability increases the complexity of space mission operation, while higher availability would require additional link margins that lowers the overall throughput. To improve this fundamental throughput‐availability trade‐off, data rate adaptation based on real‐time observation of the channel condition is necessary.In this paper, we model the Ka‐band channel using a Markov process to capture the impact of the temporal correlation in weather conditions. We then develop a rate adaptation algorithm to optimize the data rate based on real time feedback on the measured channel conditions. Our algorithm achieves both higher throughput and link availability as compared to the constant rate scheme presently in use. Copyright © 2007 John Wiley & Sons, Ltd.
Network layer performance of a satellite network with dynamic link‐layer resource allocation
Authors: Pandya Julee , Narula‐Tam Aradhana , Yao Huan , Wysocarski Jeff 
Published: February 2007

AbstractFuture packet switched military satellite communication networks are being designed with dynamic resource allocation on the up‐ and down‐links in order to efficiently utilize the limited Radio Frequency (RF) resources. The resource allocation algorithms must be designed to achieve good system efficiency and user performance in addition to optimizing link‐layer efficiency. An OPNET simulation environment is used to model and evaluate system performance for a satellite network with dynamically provisioned up‐ and down‐links under dynamic traffic and channel variations. Link‐layer resource allocation algorithms are developed and performance is evaluated in terms of application layer throughput, loss, delay, and jitter as well as system resource utilization. Copyright © 2007 John Wiley & Sons, Ltd.
RCP‐Planet: a rate control protocol for InterPlaNetary Internet
Authors: Fang Jian , Akyildiz Ian F. 
Published: February 2007

AbstractUDP traffic is a part of the aggregate traffic over InterPlaNetary Internet backbone links, which includes planet images and multimedia data from some scientific observations. Existing rate control schemes cannot solve the rate control problem in InterPlaNetary Internet which is characterized byextremely long propagation delays,high link errors,asymmetrical bandwidth, andblackouts. In this paper, a rate control protocol, RCP‐Planet, is proposed to address all the above challenges. RCP‐Planet consists of two novel algorithms, i.e.Begin StateandOperational State. The protocol is based on a novel rate probing mechanism, i.e. sending probing sequences to capture the available bandwidth. A new rate control scheme is designed to update the transmission rate based on the observed rate for the probing sequence. Tornado codes are used for packet‐level FEC because of their fast encoding and decoding speed. Bandwidth asymmetry problem is addressed by FEC block‐level ACKs. Moreover, RCP‐Planet incorporates Blackout State into the protocol to improve performance in blackout conditions. Simulation results show that RCP‐Planet achieves high throughput performance, fairness, and is delay tolerant. Copyright © 2007 John Wiley & Sons, Ltd.
Water‐Soluble Germanium(0) Nanocrystals: Cell Recognition and Near‐Infrared Photothermal Conversion Properties
Authors: Lambert Timothy N. , Andrews Nicholas L. , Gerung Henry , Boyle Timothy J. , Oliver Janet M. , Wilson Bridget S. , Han Sang M. 
Published: February 2007

AbstractSurfactant‐passivated germanium nanocrystals (Ge(0) NCs) 3–5 nm in diameter were synthesized and encapsulated with functionalized phospholipids to yield water‐soluble Ge(0) NCs. Upon encapsulation, the NCs retained their cubic crystalline phase and displayed good resistance to oxidation, as determined by transmission electron microscopy and X‐ray photoelectron spectroscopy. As a test of their cell compatibility, the ability of carboxyfluorescein (CF)‐labeled dinitrophenyl (DNP)‐functionalized Ge(0) NCs to crosslink dinitrophenol‐specific immunoglobulin E antibodies on the surface of mast cells (RBL‐2H3) was examined in vitro. Treatment with a multivalent DNP antigen (i.e., DNP‐Ge(0) NCs or CF‐DNP‐Ge(0) NCs) caused crosslinking of FcεRI receptors and cellular responses, which were evaluated with morphological and colorimetric assays and live‐cell fluorescence microscopy. Incubation of RBL‐2H3 cells with Ge(0) NCs for ≈24 h gave less than a 2 % increase in cell death as compared to DNP‐functionalized bovine serum albumin. When irradiated with near‐infrared (NIR) radiation (λexc=770 nm, 1.1 W cm−2) from a continuous‐wave Ti:sapphire laser, the bulk‐solution temperature of a toluene solution containing 20 mg mL−1 Ge(0) NCs increased by ≈35 °C within 5 min. Phospholipid‐encapsulated water‐soluble Ge(0) NCs at concentrations of 1.0 mg mL−1 also displayed stable photothermal behavior under repetitive and prolonged NIR laser exposures in water, to yield a temperature increase of ≈20 °C within 5 min (λexc=770 nm, 0.9 W cm−2). The photothermal efficiency of water‐soluble Ge(0) NCs compares favorably with a recent report for Au nanoshells.
Critically identifying stakeholders
Authors: Achterkamp Marjolein C. , Vos Janita F. J. 
Published: February 2007

AbstractAlthough (the relevance of) stakeholder management receives considerable attention in literature, the problem of actual stakeholder identification is yet unresolved. This article analyses the potential contributions of critical systems thinking to solving this problem. Especially Ulrich's notion of boundary critique, by which he focuses on stakeholder roles and particularly the role of ‘the affected’, seems a fruitful contribution. By adapting the role definitions towards a project context, including project dynamics, and adding operating instructions, a method has been developed that can be used for actual stakeholder identification in organizational projects. This method is demonstrated on two projects. The results show that this adapted version of boundary critique, which in its original form mainly is used in the context of civil society, is also relevant in an organizational profit‐based context. Copyright © 2007 John Wiley & Sons, Ltd.
A critical systems perspective on the design of organizational space
Authors: Mobach Mark P. 
Published: February 2007

AbstractThis paper is the first to introduce critical systems thinking into a new emerging research strand: the design of organizational space. The study revealed two things. First, critical systems thinking provides a thorough framework to understand the possibilities to connect organization and building; both in a conceptual understanding of the mutual relations and with regard to the practical implications that such connections have. Second, an application of critical systems thinking in an immersive virtual environment resulted in an inspiring debate around all sorts of facts and values of the current and expected future states of organizational space. It raised the awareness about a true interdisciplinary design in organization and architecture and allowed significant improvements to be made. This paper may be also regarded as an introduction to an application of critical systems thinking in other design processes where human and technical systems designs are interwoven. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of phylloquinone supplementation on biochemical markers of vitamin K status and bone turnover in postmenopausal women
Authors: Bügel Susanne , Sørensen A. Dorthe , Hels Ole , Kristensen Mette , Vermeer Cees , Jakobsen Jette , Flynn Albert , Mølgaard Christian , Cashman Kevin D. 
Published: February 2007

While current intakes of phylloquinone (vitamin K1) in many populations are believed to be sufficient to maintain normal blood coagulation, these may be insufficient to cover the requirements for optimal bone metabolism. Therefore, the objective of the present study was to investigate the effect of increasing phylloquinone intakes above the usual dietary intake for 6 weeks on biochemical markers of vitamin K status and bone turnover in postmenopausal women. Thirty-one postmenopausal women completed this 3 × 6-week randomised cross-over study, in which volunteers were supplemented with 0 (placebo), 200, and 500 μg phylloquinone/d. In addition, the volunteers were given 10 μg vitamin D3/d throughout the study period. With increasing phylloquinone intake, the concentration of serum γ-carboxylated and under-γ-carboxylated osteocalcin was significantly increased and decreased, respectively, in a dose-dependent manner (P < 0·001). Mean serum phylloquinone concentration was significantly (P < 0·001) higher with daily supplementation with 500 μg phylloquinone/d compared with that during either of the placebo or 200 μg phylloquinone/d supplementation periods, which did not differ (P = 0·15). Serum total osteocalcin was significantly (P < 0·001) increased in response to daily supplementation with 500 (but not 200) μg phylloquinone compared with placebo. Serum bone-specific alkaline phosphatase as well as the urinary markers of bone resorption (N-telopeptide cross-links of collagen, pyridinoline and deoxypyridinoline) and urinary γ-carboxyglutamate were unaffected by phylloquinone supplementation. In conclusion, while daily supplementation with 200 and 500 μg phylloquinone/d for 6 weeks increased vitamin K status in postmenopausal women, it had no effect on bone turnover.
Vitamin A deficiency modifies lipid metabolism in rat liver
Authors: Oliveros Liliana B. , Domeniconi María A. , Vega Verónica A. , Gatica Laura V. , Brigada Ana M. , Gimenez María S. 
Published: February 2007

Liver fatty acid metabolism of male rats fed on a vitamin A-deficient diet for 3 months from 21 d of age was evaluated. Vitamin A restriction produced subclinical plasma and negligible liver retinol concentrations, compared with the control group receiving the same diet with 4000 IU vitamin A (8 mg retinol as retinyl palmitate)/kg diet. Vitamin A deficiency induced a hypolipidaemic effect by decreasing serum triacylglycerol, cholesterol and HDL-cholesterol levels. The decrease of liver total phospholipid was associated with low phosphatidylcholine synthesis observed by lower [14C]choline incorporation into phosphatidylcholine, compared with control. Also, liver fatty acid synthesis decreased, as was indicated by activity and mRNA expression of acetyl-CoA carboxylase (ACC), and incorporation of [14C]acetate into saponified lipids. A decrease of the PPARα mRNA expression was observed. Liver mitochondria of vitamin A-deficient rats showed a lower total phospholipid concentration coinciding with a decrease of the cardiolipin proportion, without changes in the other phospholipid fractions determined. The mitochondria fatty acid oxidation increased by 30 % of the control value and it was attributed to a high activity and mRNA expression of carnitine palmitoyltransferase-I (CPT-I). An increase in serum β-hydroxybutyrate levels was observed in vitamin A-deficient rats. Vitamin A deficiency alters the mitochondria lipid composition and also enhances fatty acid oxidation by modifiying the production of malonyl-CoA, the endogenous inhibitor of CPT-I, due to decreased activity of liver ACC. The incorporation of vitamin A into the diet of vitamin A-deficient rats reverted all the changes observed.
Daily intake of conjugated linoleic acid-enriched yoghurts: effects on energy metabolism and adipose tissue gene expression in healthy subjects
Authors: Nazare Julie-Anne , Perrière Aude Brac de la , Bonnet Fabrice , Desage Michel , Peyrat Jocelyne , Maitrepierre Christine , Louche-Pelissier Corinne , Bruzeau Joëlle , Goudable Joëlle , Lassel Taous , Vidal Hubert , Laville Martine 
Published: February 2007

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid. The present study was designed to determine whether 14-week CLA supplementation as triacylglycerols (3·76 g) with a 50 : 50 combination of the two main isomers (35 %cis-9,trans-11 and 35 %trans-10,cis-12) added to flavoured yoghurt-like products was able to alter body composition in healthy subjects and to alter the expression of several key adipose tissue genes (PPAR γ, lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and uncoupling protein 2 (UCP-2)). Forty-four healthy subjects were randomly assigned to consume daily either a CLA-supplemented yoghurt-like product or a placebo yoghurt for 98 d. There were no significant effects of CLA supplementation on body weight, fat mass or free fat mass. Basal energy expenditure expressed as kg free fat mass increased significantly in the CLA group (123·3 (sem2·5) kJ/kg free fat mass per d on day 98v.118·7 (sem2·3) kJ/kg free fat mass per d on day 0,P = 0·03). PPAR γ mRNA gene expression increased significantly with CLA supplementation (53 (sem20) %,P < 0·01) and a significant reduction in mRNA levels of HSL was observed ( − 42 (sem7) %,P = 0·01). The levels of UCP-2 and LPL mRNA were not affected. The present results suggest that a 98 d supplementation diet with a 50 : 50 mixture of the two CLA isomerscis-9,trans-11 andtrans-10,cis-12 in a dairy product was unable to alter body composition, although a significant increase in the RMR has been induced. Moreover, changes in mRNA PPAR γ and HSL in adipose tissue were recorded.
The effect of marine oil-derivedn-3 fatty acids on transepithelial calcium transport in Caco-2 cell models of healthy and inflamed intestines
Authors: Gilman Jennifer , Cashman Kevin D. 
Published: February 2007

Marine oil-derivedn-3 fatty acids have been shown to stimulate intestinal Ca absorption in animal studies, but the effects of such fatty acids on Ca absorption in human subjects are relatively unknown. In particular,n-3 fatty acids may be of therapeutic value for some Crohn's disease patients who experience Ca malabsorption. Therefore, the aim of the present study was to investigate the effect of 20 : 5n-3 and 22 : 6n-3 on transepithelial Ca transport across monolayers of healthy Caco-2 cells as well as of TNF-α-treated Caco-2 cells (anin vitromodel of Crohn's disease). Caco-2 cells were seeded onto permeable filter supports and allowed to differentiate into monolayers, which were treated with 80 μm-20 : 5n-3, 80 μm-22 : 6n-3, or 40 μm-20 : 5n-3+40 μm-22 : 6n-3 for 6 or 8 d, with or without co-treatment with TNF-α (10 ng/ml) (n11–15 monolayers per treatment). On day 16, transepithelial and transcellular transport of45Ca and fluorescein transport (a marker of paracellular diffusion) were measured. Treatment of healthy and inflamed Caco-2 cells with 20 : 5n-3, 22 : 6n-3 and both fatty acids combined for 8 d significantly (P < 0·005–0·01) increased total transepithelial Ca transport compared with that in control, effects which were mediated by an enhanced rate of transcellular Ca transport. The effects ofn-3 fatty acids on Ca absorption after 6 d were less clear-cut. In conclusion, the presentin vitrofindings highlight the need to investigate the effect of marine oil-basedn-3 fatty acids on Ca absorptionin vivoin studies of healthy human subjects as well as of Crohn's disease patients.