bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly versatile confocal microscopy system based on a tunable femtosecond Er:fiber source
Authors: Träutlein D. , Adler F. , Moutzouris K. , Jeromin A. , Leitenstorfer A. , Ferrando‐May E. 
Published: January 2008

AbstractThe performance of a confocal microscopy setup based on a single femtosecond fiber system is explored over a broad range of pump wavelengths for both linear and nonlinear imaging techniques. First, the benefits of a laser source in linear fluorescence excitation that is continuously tunable over most of the visible spectrum are demonstrated. The influences of subpicosecond pulse durations on the bleaching behavior of typical fluorophores are discussed. We then utilize the tunable near‐infrared output of the femtosecond system in connection with a specially designed prism compressor for dispersion control. Pulses as short as 33 fs are measured in the confocal region. As a consequence, 2 mW of average power are sufficient for two‐photon microscopy in an organotypic sample from the mouse brain. This result shows great prospect for deep‐tissue imaging in the optimum transparency window around 1100 nm. In a third experiment, we prove that our compact setup is powerful enough to exploit even higher‐order nonlinearities such as three‐photon absorption that we use to induce spatially localized photodamage in DNA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
pH‐induced conformation changes of adsorbed vitronectin maximize its bovine aortic endothelial cell binding ability
Authors: Bernards Matthew T. , Jiang Shaoyi 
Published: January 2008

AbstractVitronectin (VN) is an important matricellular protein that plays a role in cell adhesion, cell migration, wound healing, and inflammation. VN is present in both serum and plasma and studies have shown that it has significant surface enrichment on implanted biomaterials as compared to other proteins present in plasma. Previously, charged self‐assembled monolayers (SAMs) have been shown to influence the orientation and conformation of adsorbed proteins and their subsequent bioactivity. In addition, numerous studies have shown that the conformation of VN plays a critical role in its bioactive properties. In this study, both the orientation and conformation of adsorbed VN are systematically studied to determine which of these has the greater influence on its cell binding ability. Atomic force microscopy was used to qualitatively asses the adsorbed amount of VN on positively and negatively charged SAMs both before and after conformation changes induced by pH. Cell adhesion assays were then performed to compare the bovine aortic endothelial cell (BAEC) binding ability of VN in three different conformations on positively and negatively charged surfaces. The results indicate that conformation, not orientation, plays the more important role in the BAEC adhesion properties of VN. In addition, the cell binding properties of VN were maximized when the protein is in the conformation imparted to it by acidic conditions. This indicates that the bioactivity of VN is maximized when in its conformation typical of an acidic wound healing environment, emphasizing the biological relevance of this protein for cell binding under these natural biological conditions. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
A mathematical model for predicting drug release from a biodurable drug‐eluting stent coating
Authors: Hossainy Syed , Prabhu Santosh 
Published: January 2008

AbstractDrug‐eluting stents (DESs) are drug–device combination products that have been commercialized and demonstrated to be safe and efficacious in treating coronary artery disease. They have been very effective in reducing the extent of neointimal hyperplasia and therefore in preventing or minimizing the occurrence of in‐stent restenosis. In order to develop a successful DES, it is imperative that the coating be designed so as to deliver, after stent implantation, a therapeutic dose of the drug for the desired time duration at the site of the arterial blockage. Mathematical models are very valuable tools that can be used to study the effect of different coating parameters on drug delivery and can therefore help in coating design. We have developed a bimodal lumped‐parameter mass transport model to describe the release of the drug everolimus from a biodurable fluoropolymer‐based DES coating. We assume that the dispersed drug phase contributes to two discrete modes of drug transport through the coating. These are the fast mode (mode I) which is the release of the drug from a highly percolated structure of drug phase within the polymer, and the slow mode (mode II) which is the release of the drug from a nonpercolated, polymer‐encapsulated phase of the drug within the coating. The three coefficients in the governing equations describing the model, i.e. the two effective diffusivities corresponding to each of the two modes and the fraction of the drug in one of the two modes, were determined by fitting with available DES release data. The predictive power of the model is demonstrated by comparing the release rate from different coating configurations (thickness and drug to polymer ratios) with experimental data. Also, it is demonstrated that if limited experimental data are available at early time points, the model can be used to predict drug release at subsequent time points. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Chemical strengthening of a dental lithium disilicate glass–ceramic material
Authors: Fischer Horst , De Souza Roger A. , Wätjen Anja M. , Richter Silvia , Edelhoff Daniel , Mayer Joachim , Martin Manfred , Telle Rainer 
Published: January 2008

AbstractChemical strengthening of dental ceramics by ion exchange has hitherto only been confirmed for feldspathic porcelains. The objective of this study was to examine whether the strength of lithium disilicate glass–ceramics can be increased by ion exchange as well. A lithium disilicate glass–ceramic material was treated in different molten salts. The concentration gradients of the relevant ions in the surface layer were investigated by means of electron probe microanalysis and secondary ion mass spectroscopy. Characteristic strength and Weibull modulus data were determined. An increase in strength of 25% was achieved by treatment in potassium nitrate. The chemical analyses revealed that the increase in strength resulted from an exchange of potassium for lithium ions. We conclude that ion‐exchange treatments can increase the strength of lithium disilicate glass–ceramics. The improved material could be used for highly stressed applications, such as posterior crowns or inlay‐retained bridges, with higher mechanical reliability. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
High concentration of residual aluminum oxide on titanium surface inhibits extracellular matrix mineralization
Authors: Canabarro A. , Diniz M. G. , Paciornik S. , Carvalho L. , Sampaio E. M. , Beloti M. M. , Rosa A. L. , Fischer R. G. 
Published: January 2008

AbstractIn the present study we characterized titanium (Ti) surfaces submitted to different treatments and evaluated the response of osteoblasts derived from human alveolar bone to these surfaces. Five different surfaces were evaluated: ground (G), ground and chemical etched (G1‐HF for 60 s), sand blasted (SB‐Al2O3 particles 65 μm), sand blasted and chemical etched (SLA1‐HF for 60 s and SLA2‐HF for 13 s). Surface morphology was evaluated under SEM and roughness parameters by contact scanning instrument. The presence of Al2O3 was detected by EDS and the amount calculated by digital analyses. Osteoblasts were cultured on these surfaces and it was evaluated: cell adhesion, proliferation, and viability, alkaline phosphatase activity, total protein content, and matrix mineralization formation. Physical and chemical treatments produced very different surface morphologies. Al2O3 residues were detected on SB and SLA2 surfaces. Only matrix mineralization formation was affected by different surface treatments, being increased on rough surface (SLA1) and reduced on surface with high amount of Al2O3 residues (SB). On the basis of these findings, it is possible to conclude that high concentration of residual Al2O3 negatively interfere with the process of matrix mineralization formation in contact with Ti implant surfaces. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Repositioning of ETO gene in cells treated with VP‐16, an inhibitor of DNA‐Topoisomerase II
Authors: Rubtsov Mikhail A. , Terekhov Sergey M. , Razin Sergey V. , Iarovaia Olga V. 
Published: January 2008

AbstractThe translocation t(8;21)(q22;q22) affecting AML1 and ETO genes is known to be one of the frequent chromosome translocations in acute myeloid leukemia. But no data have been available up to date concerning mutual positioning of these particular genes in the nucleus of a living cell as well as the mechanism of their rapprochement and realignment. Here we show that there is no proximity between these two genes in the primary nuclei of normal human male fibroblasts and moreover that these genes are located in different nuclear layers. But we further show that treatment of cells with VP‐16 (etoposide), an inhibitor of DNA topoisomerase II widely used in anticancer chemotherapy, causes the ETO gene repositioning which allows AML1 and ETO genes to be localized in the same nuclear layer. Inhibitor studies demonstrate that such an effect is likely to be connected with the formation of stalled cleavable complexes on DNA. Finally, inhibition of ETO gene repositioning by 2,3‐butanedione monoxime (BDM) suggests that this process depends on nuclear myosin. Together, our data corroborate the so called “breakage first” model of the origins of recurrent reciprocal translocation. J. Cell. Biochem. 104: 692–699, 2008. © 2008 Wiley‐Liss, Inc.
Accuracy of T1 measurement with 3‐D Look‐Locker technique for dGEMRIC
Authors: Li Wei , Scheidegger Rachel , Wu Ying , Vu Anthony , Prasad Pottumarthi V. 
Published: January 2008

AbstractPurposeTo validate the accuracy of T1 measurement by three‐dimensional Look‐Locker method (3D LL) for delayed gadolinium‐enhanced MRI of cartilage (dGEMRIC) of human subjects with and without osteoarthritis (OA), as compared with two‐dimensional inversion recovery fast spin‐echo (2D IR‐FSE) technique.Materials and MethodsMR sagittal images of the knees were acquired for T1 mapping in 29 subjects with standard 2D IR‐FSE and 3D LL sequences 90–135 min following administration of 0.2 mmol/kg Gd‐DTPA2−. T1 maps of femoral and tibial cartilage were generated using custom software. Comparisons in T1 values between the two techniques were performed using regression analysis.ResultsGood agreement in T1 values between 2D IR‐FSE and 3D LL was observed (R values of 0.90, and 0.85, and 0.86 for all, OA, and control subjects, respectively) when acquired within 15 min.ConclusionThe 3D LL sequence provides accurate T1 estimates of articular cartilage with advantages of entire joint coverage, shorter acquisition time, and a wide range of inversion times sampled within a single acquisition. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.
Akt activation is involved in P2Y12 receptor‐mediated chemotaxis of microglia
Authors: Irino Yasuhiro , Nakamura Yasuko , Inoue Kazuhide , Kohsaka Shinichi , Ohsawa Keiko 
Published: January 2008

AbstractMicroglia play a variety of significant roles in the central nervous system (CNS), and in one of those roles they undergo morphological change in response to neural injury and migrate to the injured region. We previously reported that ATP/ADP promotes microglial chemotaxis via the Gi/o‐coupled P2Y12 receptor; however, the intracellular signaling underlying P2Y12‐receptor‐mediated microglial chemotaxis is not fully understood. In this study, we examined the role of phospholipase C (PLC) and calcium signaling in ADP‐induced microglial chemotaxis. A PLC inhibitor, U73122, significantly suppressed the chemotaxis and completely blocked the ADP‐evoked intracellular calcium response, and a calcium chelator, BAPTA‐AM, inhibited the chemotaxis. These results indicate that ADP‐induced microglial chemotaxis is regulated by a PLC‐mediated calcium pathway. ADP stimulation induced Akt phosphorylation in microglia, and the phosphorylation was inhibited by a P2Y12 receptor antagonist, AR‐C69931MX. The Akt phosphorylation was blocked by U73122 and BAPTA‐AM as well as by a phosphatidylinositol 3‐kinase (PI3K) inhibitor, wortmannin, and inhibition of the Akt activation resulted in failure of chemotaxis. These results indicate that Akt activation is dependent on the PI3K pathway and a PLC‐mediated increase in intracellular calcium and suggest that Akt activation is involved in ADP‐induced microglial chemotaxis. © 2008 Wiley‐Liss, Inc.
El Niño and Indian Ocean influences on Indonesian drought: implications for forecasting rainfall and crop productivity
Authors: D'Arrigo Rosanne , Wilson Rob 
Published: January 2008

AbstractIndonesia is impacted by severe droughts that cause major food shortages over much of the country, and have long been linked with El Niño events in the tropical Pacific Ocean. Despite seasonal forecasts based on relatively complex climate models, the 1997–1998 ‘El Niño of the century’ was still followed by huge shortfalls in crop production (e.g. a loss of 3 million tons of rice in Java alone), reflecting the large gap that can exist between these forecasts and their actual utilization in agricultural planning. Alternatively, simple predictive models of rainfall and crop yields for Indonesia and other Indian Ocean rim countries have utilized an index of equatorial Pacific sea surface temperatures (Niño‐3.4 SST), and related this index directly to indices of rainfall and crop productivity. However, these latter models have not included climatic information from the Indian Ocean, also implicated as a likely cause of drought in western Indonesia. Here we show that an index of Indian Ocean SSTs, when combined with the previously utilized Niño‐3.4 SSTs, provides a significantly more accurate model of Sept‐Dec drought (PDSI) over Java, Indonesia, than Niño‐3.4 SSTs alone (ar2 64.5% vs 37.9%). Based solely on data for the month of August, this model provides the best tradeoff between model skill and adequate lead time for the Sept‐Dec rice planting season. Such simple models can be used to generate readily usable early warning forecasts of drought and crop failure risk in Indonesia, particularly in the western part of the country that is most influenced by Indian Ocean climate variability. Copyright © 2008 Royal Meteorological Society
GM food and neophobia: connecting with the gatekeepers of consumer choice
Authors: Knight John G , Holdsworth David K , Mather Damien W 
Published: January 2008

AbstractResistance to importation of genetically modified (GM) foods in rich countries has deterred governments in many food‐exporting countries from approving the planting of GM food crops for fear of damaging export markets for conventional food. Apart from governments that have actively imposed barriers to entry, another level of resistance can arise from food distribution channel members deciding not to import foods which they believe consumers in their markets will not want. GM foods fall in this category in some markets, particularly in Europe. In China and India, the two most populous consumer markets, pragmatic considerations appear likely to overcome neophobia regarding this technology, provided that benefits are adequately communicated to consumers. Choice‐modelling experiments show that the same may well be true in Europe. Copyright © 2008 Society of Chemical Industry
Strategic inventory in capacitated supply chain procurement
Authors: Keskinocak Pınar , Chivatxaranukul Kasarin , Griffin Paul M. 
Published: January 2008

AbstractWe study the strategic role of inventory in a sequential two‐period procurement setting, where the supplier's capacity in the first period is limited and the retailer has the option to hold inventory. We compare the equilibrium under a dynamic contract, where the decisions are made at the beginning of each period, and a commitment contract, where the decisions for both periods are made at the beginning of the first period. We show that there is a critical capacity level below which the outcomes under both types of contracts are identical. When the first period capacity is above the critical level, the retailer holds inventory in equilibrium and the inventory is carried due to purely strategic reasons; as capacity increases, so does the strategic role of inventory. The supplier always prefers lower capacity than the retailer, and the difference between supplier‐optimal and supply‐chain optimal capacities, and the corresponding profits, can be significant. Finally, we find that the retailer's flexibility to hold inventory is not always good for the participants or for the channel. Copyright © 2008 John Wiley & Sons, Ltd.
Modeling and optimization of look‐locker spin labeling for measuring perfusion and transit time changes in activation studies taking into account arterial blood volume
Authors: Francis S.T. , Bowtell R. , Gowland P.A. 
Published: January 2008

AbstractThis work describes a new compartmental model with step‐wise temporal analysis for a Look‐Locker (LL)‐flow‐sensitive alternating inversion‐recovery (FAIR) sequence, which combines the FAIR arterial spin labeling (ASL) scheme with a LL echo planar imaging (EPI) measurement, using a multireadout EPI sequence for simultaneous perfusion and T measurements. The new model highlights the importance of accounting for the transit time of blood through the arteriolar compartment, δ, in the quantification of perfusion. The signal expected is calculated in a step‐wise manner to avoid discontinuities between different compartments. The optimal LL‐FAIR pulse sequence timings for the measurement of perfusion with high signal‐to‐noise ratio (SNR), and high temporal resolution at 1.5, 3, and 7T are presented. LL‐FAIR is shown to provide better SNR per unit time compared to standard FAIR. The sequence has been used experimentally for simultaneous monitoring of perfusion, transit time, and T changes in response to a visual stimulus in four subjects. It was found that perfusion increased by 83 ± 4% on brain activation from a resting state value of 94 ± 13 ml/100 g/min, while T increased by 3.5 ± 0.5%. Magn Reson Med 2007. © 2007 Wiley‐Liss, Inc.
New phosphorylated derivatives of carboxymethylcellulose with osteogenic activity
Authors: Leone Gemma , Torricelli Paola , Giardino Roberto , Barbucci Rolando 
Published: January 2008

AbstractNew phosphorylated derivatives of carboxymethylcellulose (CMC) and amidic CMC were realized using trisodium trimetaphosphate (STMP) as the phosphating agent. The new polysaccharides were characterized by infrared spectroscopy and elemental analysis. The characterized polysaccharides were then crosslinked and their rheological and swelling properties determined. The presence of phosphate groups made the three‐dimensional structures more compact and harder than the corresponding non‐phosphated hydrogels. Evaluation of the bioactivity of phosphorylated hydrogels toward osteoblast‐like cells (MG63) showed a significant increase in the osteocalcin production. Copyright © 2008 John Wiley & Sons, Ltd.
Maternal characteristics associated with pregnancy exposure to FDA category C, D, and X drugs in a Canadian population
Authors: Yang Tubao , Walker Mark C. , Krewski Daniel , Yang Qiuying , Nimrod Carl , Garner Peter , Fraser William , Olatunbosun Olufemi , Wen Shi Wu 
Published: January 2008

AbstractPurposeTo estimate the frequency of exposure to prescription Food and Drug Administration (FDA) category C, D, and X drugs in pregnant women, and to analyze the maternal characteristics associated with such an exposure.MethodsA 50% random sample of women who gave a birth in Saskatchewan between January 1, 1997 and December 31, 2000 was chosen for the study. The rate of exposure to FDA category C, D, or X drugs recorded in the pharmacist database was estimated. Associations of exposure to FDA category C, D, and X drugs with maternal characteristics were evaluated using multiple logistical regression, with adjusted odds ratios (ORs) and its 95% confidence intervals (CIs) as the association measures.ResultsA total of 18 575 women were included in this study. Among them, 3604 (19.4%) had exposure to one or more FDA category C, D, and X drugs during pregnancy. Category C drugs were the most frequently used drugs (15.8%), followed by D drugs (5.2%), and X drugs (3.9%). Women with chronic health conditions had fourfold at increased risk of exposure than women without. Regardless of health status, women who were <20 years of age, who had a parity ≥3, and who were on social assistance plan were at increased risk of pregnancy exposure to these drugs.ConclusionsAbout 19.4% pregnant women are exposed to FDA C, D or X drugs during pregnancy. Women with chronic diseases, younger age, increased parity, and under social assistance are at increased risk of exposure to FDA C, D, or X drugs. Copyright © 2008 John Wiley & Sons, Ltd.
Proteomic analysis of human osteoarthritic chondrocytes reveals protein changes in stress and glycolysis
Authors: Ruiz‐Romero Cristina , Carreira Vanessa , Rego Ignacio , Remeseiro Silvia , López‐Armada María J. , Blanco Francisco J. 
Published: January 2008

AbstractOsteoarthritis (OA) is characterized by cartilage degradation. The chondrocyte is the only cell type present in mature cartilage, and it is important in the control of cartilage integrity. The aim of this study was to analyze, by a proteomic approach, the changes that are characteristic of OA chondrocytes, and to identify new OA‐related proteins. Chondrocytes were isolated from the cartilage of ten OA patients undergoing joint replacement and ten donors with no history of joint disease. Whole‐cell proteins were resolved by 2‐DE and stained with SYPRO Ruby. Protein expression patterns of 2‐DE gels from OA and normal chondrocyte proteins were analyzed with PDQuest 7.3.1 software. OA‐related proteins were identified by MALDI‐TOF or MALDI‐TOF/TOF MS. The results were validated for ANXA1, GSTO1, GRP78, and HSP90β in cells by Western blotting and in tissue cartilage by immunohistochemistry. Results showed an average of 700 protein spots that were present in the 2‐DE gels. Compared to normal chondrocytes, 19 protein spots were found to be significantly increased in OA cells (ratio OA:N≥2.0, p<0.05), whereas nine were decreased in OA chondrocytes (ratio OA:N≤0.5, p<0.05). Three stress response proteins were increased (HSP90β, GRP78, and GRP94) and three proteins involved in glycolysis were decreased (enolase, glyceraldehyde 3‐phosphate dehydrogenase, and fructose biphosphate aldolase). Functionally, almost all proteins could be classified as proteins involved in cellular metabolism (33%), structure (21%), or protein targeting (21%).