bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allosteric properties of hemoglobin and the plasma membrane of the erythrocyte: New insights in gas transport and metabolic modulation
Authors: De Rosa Maria Cristina , Alinovi Cristiana Carelli , Galtieri Antonio , Russo Annamaria , Giardina Bruno 
Published: April 2008

AbstractWithin the red blood cell the hemoglobin molecule is subjected to modulation mechanisms, namely homo‐ and heterotropic interactions, which optimize its functional behavior to the specific physiological requirements. At the cellular level, these modulation mechanisms are utilized to perform a number of other functions that are not minor with respect to the basic function of oxygen transport. Here we report some key examples concerning: (i) the interaction of hemoglobin with band 3 and its influence on glucose metabolism; (ii) the role of the ligand‐linked quaternary transition of hemoglobin in the control of “NO bioactivity” and of gas diffusion; (iii) the interaction of plasma membrane with the various oxidative derivatives of the hemoglobin molecule. © 2008 IUBMB IUBMB Life, 60(2): 87–93, 2008
Stable isotope‐assisted metabolomics in cancer research
Authors: Lane Andrew N. , Fan Teresa W.‐M. , Higashi Richard M. 
Published: April 2008

AbstractStable Isotopes are nontoxic, naturally occurring elemental surrogates that are fully compatible with live organisms, including humans in a clinical setting. The ability to enrich common compounds with rare isotopes such as carbon (13C) and nitrogen (15N) is the only practical means by which metabolic pathways can be traced, performed by following the fate of individual atoms from the source molecules to products via metabolic transformation. Changes in regulation of pathways are therefore captured by this approach, which leads to deeper understanding of fundamental biochemistry of cancer compared with non‐cancerous cells, which can lead to new diagnostic tools. © 2008 IUBMB IUBMB Life, 60(2): 124–129, 2008
From anchorage dependent proliferation to survival: Lessons from redox signalling
Authors: Chiarugi Paola 
Published: April 2008

AbstractAnchorage to extracellular matrix (ECM) is essential for the execution of the mitotic program of nontransformed cells as they need simultaneous signals starting from mitogenic molecules, as growth factors (GFs), and adhesive agents belonging to ECM. Reactive oxygen species play a key function during both GF and integrin receptor signalling and are therefore recognised to have a synergistic function with several others transducers for anchorage‐dependent growth (ADG). Indeed, redox‐regulated proteins include protein tyrosine phosphatases, protein tyrosine kinases, small GTPases, cytoskeleton proteins, as well as several transcription factors. In this review, we focus on the role of reactive oxygen species (ROS) as key second messengers granting a proper executed mitosis for anchorage‐dependent cells through redox regulation of several downstream targets. Besides, redox signals elicited by ECM contact assure a protection from anoikis, a specific apoptosis induced by lack of anchorage. Cancer cells frequently show a deregulation of ROS production and a constitutive oxidative stress has been associated to the achievement of an invasive phenotype. Hence, in cancer cells, the constitutive deregulation of both mitogenic and survival pathways, likely mimicking autocrine/adhesive signals, helps to guide the transformed cells to escape the innate apoptotic response to abolish the signals started by cell/ECM contact, thus sustaining the spreading of anchorage‐independent cancer cells and the metastases growth. © 2008 IUBMB IUBMB Life, 60(5): 301–307, 2008
Structure–function studies of glutamate synthases: A class of self‐regulated iron‐sulfur flavoenzymes essential for nitrogen assimilation
Authors: Vanoni Maria Antonietta , Curti Bruno 
Published: April 2008

AbstractGlutamate synthases play with glutamine synthetase an essential role in nitrogen assimilation processes in microorganisms, plants, and lower animals by catalyzing the net synthesis of one molecule of L‐glutamate from L‐glutamine and 2‐oxoglutarate. They exhibit a modular architecture with a common subunit or region, which is responsible for the L‐glutamine‐dependent glutamate synthesis from 2‐oxoglutarate. Here, a PurF‐ (Type II‐ or Ntn‐) type amidotransferase domain is coupled to the synthase domain, a (β/α)8 barrel containing FMN and one [3Fe‐4S]0,+1 cluster, through a ∼30 Å‐long intramolecular tunnel for the transfer of ammonia between the sites. In bacterial and eukaryotic GltS, reducing equivalents are provided by reduced pyridine nucleotides thanks to the stable association with a second subunit or region, which acts as a FAD‐dependent NAD(P)H oxidoreductase and is responsible for the formation of the two low potential [4Fe‐4S]+1,+2 clusters of the enzyme. In photosynthetic cells, reduced ferredoxin is the physiological reductant. This review focus on the mechanism of cross‐activation of the synthase and glutaminase reactions in response to the bound substrates and the redox state of the enzyme cofactors, as well as on recent information on the structure of the αβ protomer of the NADPH‐dependent enzyme, which sheds light on the intramolecular electron transfer pathway between the flavin cofactors. © 2008 IUBMB IUBMB Life, 60(5): 287–300, 2008
Cooperativity and allostery in haemoglobin function
Authors: Ciaccio Chiara , Coletta Andrea , De Sanctis Giampiero , Marini Stefano , Coletta Massimo 
Published: April 2008

AbstractTetrameric haemoglobins display a cooperative ligand binding behaviour, which has been attributed to the functional interrelationship between multiple ligand binding sites. The quantitative description of this feature was initially carried out with a phenomenological approach, which was limited to the functional effect of the occupancy by a ligand molecule of a binding site on further binding steps. However, subsequent development of structural–functional models for the description of the cooperativity in haemoglobin brought about a much deeper information on the interrelationships between ligand binding at the heme and structural variations occurring in the surrounding free subunits. This approach opened the way to the evolution of the concept of allostery, which is intended as the structural–functional effect exerted by the presence of a ligand in a binding site on other binding sites present in the same molecule. This concept can be applied to either sites for the same ligand (homotropic allostery) and for sites of different ligands (heterotropic allostery). Several models trying to take into account the continuous building up of structural and functional information on the physicochemical properties of haemoglobin have been developed along this line. © 2008 IUBMB IUBMB Life, 60(2): 112–123, 2008
Adsorption of human immunoglobulin to implantable alginate‐poly‐L‐lysine microcapsules: Effect of microcapsule composition
Authors: Tam Susan K. , de Haan Bart J. , Faas Marijke M. , Hallé Jean‐Pierre , Yahia L'Hocine , de Vos Paul 
Published: April 2008

AbstractAlginate‐poly‐L‐lysine‐alginate (APA) microcapsules continue to be the most widely studied device for the immuno‐protection of transplanted therapeutic cells. Producing APA microcapsules having a reproducible and high level of biocompatibility requires an understanding of the mechanisms of the immune response towards the implants. Here, we investigate the adsorption of immunoglobulins (IgG, IgM, and IgA) onto the surface of APA microcapsules in vitro after their exposure to human serum and peritoneal fluid. Immunoglobulins (Ig) are considered to be opsonizing proteins, thus they tend to mediate inflammation when adsorbed to foreign surfaces. Ig adsorption was monitored using direct immunofluorescence. The amount of Ig adsorbed to the microcapsule surface was not significantly influenced by the guluronic acid content nor the purity level of the alginate, although microcapsules of intermediate‐G purified alginate corresponded with the lowest adsorption levels. Ig adsorption was negligible when the poly‐L‐lysine membrane was omitted, suggesting that positive charges at the microcapsule surface are responsible for binding Ig. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Ni(II) ions dysregulate cytokine secretion from human monocytes
Authors: Lewis Jill B. , Messer Regina L. W. , Pitts Leslie , Hsu Stephen D. , Hansen Jason M. , Wataha John C. 
Published: April 2008

AbstractNickel‐containing alloys are used in dentistry because of their low cost, but poor corrosion behavior increases their risk of causing adverse biological responses. Intraorally, nickel‐containing alloys accumulate bacterial plaque that triggers periodontal inflammation via toxins such as lipopolysaccharide (LPS). Recent evidence suggests that in monocytes, Ni(II) amplifies LPS‐induced secretion of several cytokines that mediate periodontal destruction. Thus, we investigated the effects of Ni(II), with or without LPS, on the secretion of a broader array of cytokines from monocytes. We then measured monocytic expression of two proteins, Nrf2 and thioredoxin‐1 (Trx1), that influence the regulation of cytokine secretion. Cytokine arrays were used to measure the effects of 0–50 μM Ni(II) on cytokine secretion from human THP1 monocytes, with or without LPS activation. Immunoblots were used to estimate Nrf2 and Trx1 levels. Our results indicate that both Ni(II) alone and Ni(II) with LPS have broad‐based effects on cytokine secretion. Ni(II) increased Nrf2 levels by threefold, and LPS amplified the effects of Ni(II) by 10‐fold. Trx1 levels did not change under any condition tested. Our results suggest that Ni(II)‐induced changes in cytokine secretion by monocytes are diverse and may be influenced by Nrf2 but are not likely influenced by changes in whole‐cell Trx1 levels. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Bacterial transmission from lens storage cases to contact lenses—Effects of lens care solutions and silver impregnation of cases
Authors: Vermeltfoort Pit B. J. , Hooymans Johanna M. M. , Busscher Henk J. , van der Mei Henny C. 
Published: April 2008

AbstractThe killing efficacies of multipurpose lens care solutions on planktonic and biofilm bacteria grown in polypropylene contact lens storage cases with and without silver impregnation and effects on bacterial transmission from storage cases to silicone hydrogel contact lenses were investigated. For transmission studies, biofilms of Staphylococcus aureus 835 or Pseudomonas aeruginosa no. 3 were grown on lens storage cases and incubated with a contact lens in different multipurpose lens care solutions (Opti‐Free®Express®, ReNu® MultiPlus®, and SoloCare Aqua™) or 0.9% NaCl. In addition, planktonic bacteria were directly suspended in multipurpose solutions and their killing efficacies were determined. The numbers of transmitted live and dead bacteria on the lenses were measured using a combination of plate counting and fluorescence microscopy. The highest killing efficacies were shown by Opti‐Free® Express® for planktonic as well as for biofilm bacteria. Silver impregnation of lens cases in combination with the prescribed solution increased the killing efficacy for P. aeruginosa in biofilms, whereas effects for S. aureus were minor. Lowest numbers of live and dead bacteria were transmitted to a lens in Opti‐Free® Express® multipurpose solution, with no significant differences between lens types and no effects of silver impregnation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Self‐setting properties and in vitro bioactivity of Ca2SiO4/CaSO4·1/2H2O composite bone cement
Authors: Huan Zhiguang , Chang Jiang , Huang Xiang‐Hui 
Published: April 2008

AbstractIn this study, a biphasic injectable bone substitute based on β‐dicalcium silicate (Ca2SiO4) and plaster of Paris (CaSO4·1/2H2O) is presented, and its behavior as cement was studied and compared to that of pure Ca2SiO4 paste. The results demonstrated that the setting time of the workable Ca2SiO4/CaSO4·1/2H2O pastes was only 15 min, which was significantly reduced as compared to that of the Ca2SiO4 paste (100 min), and the composite showed higher short‐ and long‐term mechanical strength (3.25 and 37.2 MPa, respectively) than those of the Ca2SiO4 paste (0.2 and 24.6 MPa). Similar to the pure Ca2SiO4 paste, the composite paste could induce apatite formation in simulated body fluid within a short period and degrade in Ringer's solution. Moreover, the degradation rate could be adjusted by modifying the content of the plaster within the composite cement. These results suggested that the addition of the plaster significantly improved the self‐setting properties of the Ca2SiO4 paste, and the bioactive composite cement could be a prospective candidate for further investigation as self‐setting tissue‐repairing substitute. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Effects of electron attachment on C5′O5′ and C1′N1 bond cleavages of pyrimidine nucleotides: A theoretical study
Authors: Xie Hujun , Wu Ruibo , Xia Fei , Cao Zexing 
Published: April 2008

AbstractSugar‐base C1′N1 and phosphate‐sugar C5′O5′ bond breakings of 2′‐deoxycytidine‐5′‐monophosphates (dCMP) and 2′‐deoxythymidine‐5′‐ monophosphates (dTMP) and their radical anions have been explored theoretically at the B3LYP/DZP++ level of theory. Calculations show that the low‐energy electrons attachment to the pyrimidine nucleotides results in remarkable structural and chemical bonding changes. Predicted Gibbs free energies of reaction ΔG for the C5′O5′ bond dissociation process of the radical anions are −14.6 and −11.5 kcal mol−1, respectively, and such dissociation processes may be intrinsically spontaneous in the gas phase. Furthermore, the C5′O5′ bond cleavage processes of the anionic dCMP and dTMP were predicted to have activation energies of 6.9 and 8.0 kcal mol−1 in the gas phase, respectively, much lower than the barriers for the C1′N1 bond breaking process, showing that the CO bond dissociation in DNA single strand breaks is a dominant process as observed experimentally. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Electron localizability for hexagonal element structures
Authors: Baranov A. I. , Kohout M. 
Published: April 2008

AbstractFor 21 elements crystallizing in hexagonal structure density functional calculations were performed. The topology of the electron localizability indicator (ELI) allows classifying the elements as appertaining to one of six patterns. The bifurcation diagrams as well as the electron populations in ELI basins for each pattern are discussed. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Sensitivity study of the urban heat island intensity to urban characteristics
Authors: Hamdi R. , Schayes G. 
Published: April 2008

AbstractA detailed urban surface exchange parameterization, implemented in a meso‐scale atmospheric model, has been used to study the urban heat island (UHI) intensity during a summer period in the city of Basel, Switzerland. In this urban parameterization, the city is represented as a combination of three urban classes (road, roof and wall), characterized by the size of the street canyon and the building and is thus able to take into account the momentum sink over the entire height of the building, as well as the shadowing and the radiation trapping effects. A control experiment including all the urban parameters describing the city centre of Basel produced a canyon air temperature that compared well with observations. A series of experiments was then conducted in which successively each of the urban parameters characterizing the city centre was changed providing the basis for an assessment of its effect on UHI mitigation. Copyright © 2007 Royal Meteorological Society
Unsaturated fatty acids liberated from VLDL cause apoptosis in endothelial cells
Authors: Reinbold Michael , Hufnagel Birgit , Kewitz Tobias , Klumpp Susanne , Krieglstein Josef 
Published: April 2008

AbstractCertain unsaturated fatty acids (UFAs), cleaved from lipoproteins, are known to activate the serine/threonine protein phosphatase type 2C (PP2C) α‐ and β‐isoforms. To investigate the role of UFAs in apoptosis of endothelial cells, we cocultured human umbilical vein endothelial cells (HUVECs) with THP‐1 monocytes. Phorbol‐12‐myristic‐13‐acetate (PMA)‐treated THP‐1 monocytes differentiated into macrophages and synthesized lipoprotein lipase (LPL), the major enzyme for hydrolysis of triglycerides. We demonstrated that LPL from THP‐1 macrophages released UFAs from VLDL, which were capable of inducing apoptosis in HUVECs. Physiological concentrations of VLDL did not cause apoptosis in HUVECs, whereas the combination of VLDL with LPL‐rich cell medium of THP‐1 macrophages did. THP‐1 macrophages and HUVECs in cocultivation did not interfere with each other. However, addition of VLDL to this coculture caused apoptosis in HUVECs. Furthermore, inhibition of LPL by adding orlistat to the culture medium and down‐regulation of LPL by small interfering RNA (siRNA) reduced the extent of apoptosis of HUVECs. In conclusion, our results show that the amounts of UFAs liberated from lipoproteins are high enough to induce apoptosis in endothelial cells. This underlines the proatherogenic role of UFAs in hyperlipoproteinemias.
A novel differential bandpass filter based on double‐sided parallel‐strip line dual‐mode resonator
Authors: Shi Jin , Chen Jian‐Xin , Xue Quan 
Published: April 2008

AbstractA differential bandpass filter based on double‐sided parallel‐strip line (DSPSL) dual‐mode resonator is proposed in this article. This differential bandpass filter makes use of the inherent differential feature of DSPSL to construct feeding ports and resonating unit. This filter has the advantages of low‐profile structure, low‐insertion loss for differential‐mode signal, and high suppression for common‐mode signal. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1733–1735, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23493
A wide stopband and low loss bandpass filter using multiorder harmonic suppressedI/Olines
Authors: Ramírez Vargas Steve , Weng Min‐Hang , Liauh Chihng‐Tsung , Wu Hung‐Wei , Yang Ru‐Yuan 
Published: April 2008

AbstractIn this article, a new wide stopband and low loss patch bandpass filter (BPF) using multiorder harmonic suppression is proposed. Two kinds of suppressed structures located under the I/O lines have been utilized to generate a wide harmonic suppression without affecting the performances at central frequency (f0). Design procedure of the proposed filter is described in detail in this article. The BPF designed at 2.4 GHz (f0) has the suppression up to −60, −43, and −31 dB measured at 2f0, 3f0, and 4f0, respectively. Additionally, a size reduction of the proposed filter is up to 31.2%, compared with the conventional structure. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1893–1897, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23515
One‐step hot embossing of optical rib waveguides in chalcogenide glasses
Authors: Pan W. J. , Rowe H. , Zhang D. , Zhang Y. , Loni A. , Furniss D. , Sewell P. , Benson T. M. , Seddon A. B. 
Published: April 2008

AbstractA new technique is presented for fabricating optical rib waveguides in chalcogenide glasses. As40Se60/Ge17As18Se65 (at. %) rib waveguides were fabricated in a one‐step process by hot pressing two As40Se60 fibers sandwiched between a silicon mold and a planar Ge17As18Se65 glass substrate, resulting in a series of replicated thin‐film rib structures on glass. Optical characterization at λ = 1.55 μm reveals single‐mode waveguide propagation, in agreement with numerical modeling. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1961–1963, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23534
Simulating temporal evolution of PMD‐related variables in optical fibers and emulators
Authors: Ferreira J. , Vilela de Faria G. , von der Weid J. P. 
Published: April 2008

AbstractA simulation tool for the calculation of the statistics and correlations of PMD‐related variables is presented. Calculations are performed in time domain, allowing the simulation of the temporal evolution of differential group delay (DGD); principal states of polarization (PSP); output polarization state (SOP) and received signal level, among others. Results are in good agreement with predictions from spectral calculations and experimental results. Simulations are used to compare predictions of the hinge model and to evaluate PMD outage times in optical transmissions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1950–1954, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23548
Delivery‐date and capacity management in a decentralized internal market
Authors: Erkoc Murat , Wu S. David , Gurnani Haresh 
Published: April 2008

AbstractWe study competitive due‐date and capacity management between the marketing and engineering divisions within an engineer‐to‐order (ETO) firm. Marketing interacts directly with the customers and quotes due‐dates for their orders. Engineering is primarily concerned with the efficient utilization of resources and is willing to increase capacity if the cost is compensated. The two divisions share the responsibility for timely delivery of the jobs. We model the interaction between marketing and engineering as a Nash game and investigate the effect of internal competition on the equilibrium decisions. We observe that the internal competition not only degrades the firm's overall profitability but also the serviceability. Finally, we extend our analysis to multiple‐job settings that consider both flexible and inflexible capacity. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Life on horseback: palaeopathology of two Scythian skeletons from Alexandropol, Ukraine
Authors: Wentz R. K. , de Grummond N. T. 
Published: April 2008

AbstractIn 2006, two skeletons were analysed that were previously excavated from the periphery of a Scythian burial mound, near the village of Alexandropol in southern Ukraine. Dated to ca. 325 BC, both remains are male. The first is that of a youth in his late teens who exhibits indications of biological stress and degenerative changes to the spine in the form of a Schmorl's node. The second is a middle‐aged individual with extensive healed lesions due to trauma to the right humerus and clavicle with associated bony changes of the elbow and spine. Stable isotope analyses indicate a diet based on C3 plants. Their skeletons suggest a rigorous life on horseback. Both may have served as sacrificial victims. Historical records document the strangulation of attendants and their placement around the periphery of royal burial mounds. Grave goods suggest that both were warriors, although the youth lacks the traumatic injuries exhibited by the older male. The individuals from Alexandropol may have served a Scythian king in life and in death. Copyright © 2008 John Wiley & Sons, Ltd.