bluuebunny/crossref_metadata_2025 huggingface dataset:
A single‐trace dual‐process model of episodic memory: A novel computational account of familiarity and recollection
Authors: Greve Andrea , Donaldson David I. , van Rossum Mark C.W.
Published: April 2009

Dual‐process theories of episodic memory state that retrieval is contingent on two independent processes: familiarity (providing a sense of oldness) and recollection (recovering events and their context). A variety of studies have reported distinct neural signatures for familiarity and recollection, supporting dual‐process theory. One outstanding question is whether these signatures reflect the activation of distinct memory traces or the operation of different retrieval mechanisms on a single memory trace. We present a computational model that uses a single neuronal network to store memory traces, but two distinct and independent retrieval processes access the memory. The model is capable of performing familiarity and recollection‐based discrimination between old and new patterns, demonstrating that dual‐process models need not to rely on multiple independent memory traces, but can use a single trace. Importantly, our putative familiarity and recollection processes exhibit distinct characteristics analogous to those found in empirical data; they diverge in capacity and sensitivity to sparse and correlated patterns, exhibit distinct ROC curves, and account for performance on both item and associative recognition tests. The demonstration that a single‐trace, dual‐process model can account for a range of empirical findings highlights the importance of distinguishing between neuronal processes and the neuronal representations on which they operate. © 2009 Wiley‐Liss, Inc.
Clinical application of measurement of hippocampal atrophy in degenerative dementias
Authors: Barnes Josephine , Ourselin Sebastien , Fox Nick C.
Published: April 2009

Hippocampal atrophy is a characteristic and early feature of Alzheimer's disease. Volumetry of the hippocampus using T1‐weighted magnetic resonance imaging (MRI) has been used not only to assess hippocampal involvement in different neurodegenerative diseases as a potential diagnostic biomarker, but also to understand the natural history of diseases, and to track changes in volume over time. Assessing change in structure circumvents issues surrounding interindividual variability and allows assessment of disease progression. Disease‐modifying effects of putative therapies are important to assess in clinical trials and are difficult using clinical scales. As a result, there is increasing use of serial MRI in trials to detect potential slowing of atrophy rates as an outcome measure. Automated and yet reliable methods of quantifying such change in the hippocampus would therefore be very valuable. Algorithms capable of measuring such changes automatically have been developed and may be applicable to predict decline to a diagnosis of dementia in the future. This article details the progress in using MRI to understand hippocampal changes in the degenerative dementias and also describes attempts to automate hippocampal segmentation in these diseases. © 2009 Wiley‐Liss, Inc.
Forecasting realized volatility: a Bayesian model‐averaging approach
Authors: Liu Chun , Maheu John M.
Published: April 2009

How to measure and model volatility is an important issue in finance. Recent research uses high‐frequency intraday data to constructex postmeasures of daily volatility. This paper uses a Bayesian model‐averaging approach to forecast realized volatility. Candidate models include autoregressive and heterogeneous autoregressive specifications based on the logarithm of realized volatility, realized power variation, realized bipower variation, a jump and an asymmetric term. Applied to equity and exchange rate volatility over several forecast horizons, Bayesian model averaging provides very competitive density forecasts and modest improvements in point forecasts compared to benchmark models. We discuss the reasons for this, including the importance of using realized power variation as a predictor. Bayesian model averaging provides further improvements to density forecasts when we move away from linear models and average over specifications that allow for GARCH effects in the innovations to log‐volatility. Copyright © 2009 John Wiley & Sons, Ltd.
Aggregation is not the solution: the PPP puzzle strikes back
Authors: Gadea M. Dolores , Mayoral Laura
Published: April 2009

Recently, Imbs, Mumtaz, Ravn and Rey (2005, hereinafter IMRR) have argued that much of the purchasing power parity (PPP) puzzle is due to upwardly biased estimates of persistence. According to them, the source of the bias is the existence of heterogeneous price adjustment dynamics at the sectoral level that established time series or panel data methods fail to control for. This paper re‐examines this claim in two steps. Firstly, we demonstrate that IMRR's measures of sectoral persistence are systematically downwardly biased because they are based on an inaccurate definition of the ‘average’ impulse response function (IRF). We then show that standard estimates of shock persistence are recovered after this bias is corrected. Secondly, building on the results in Mayoral (2008), which prove that aggregate and micro models induce the same shock persistence behavior, we show that estimates based on aggregate and sectoral exchange rates are, in fact, highly consistent. Thus, aggregation is not the solution to the PPP puzzle. Copyright © 2009 John Wiley & Sons, Ltd.
Wear and hardness of different core build‐up materials
Authors: Schmage Petra , Nergiz Ibrahim , Sito Fekry , Platzer Ursula , Rosentritt Martin
Published: April 2009

Before crown preparation, teeth with extensive coronal destructions are built up with core materials. Sometimes, these build ups are exposed to the oral environment without the protection of crowns. Therefore, this in vitro investigation was aimed at evaluating the wear, surface roughness, Vickers hardness, and surface structure of 10 core composites, two glass ionomer cements (GICs), and four posterior restoration composites. The three‐body wear was tested after water storage and 2,00,000 cycles. We measured both surface roughness and Vickers hardness (DIN 50133) and evaluated the surface structures by scanning electron microscopy. Results were statistically analyzed by use of the Mann‐Whitney U test (α = 0.05). Lowest wear was found for the restorative composites (20 μm Grandio; others about 40 μm). A comparison of the composites Build‐It, Chroma Core, Rebilda LC, and Rebilda DC to Quixfil showed similar wear values for each material (43–50 μm). Wear values of GICs and all others core composites ranged between 58 and 75 μm. Only Ti‐Core showed significantly higher wear than all other materials (p < 0.05). All core materials except Ti‐Core (35 HV) showed Vickers hardness values between 42 and 61 HV. Most core composites, particularly Build‐It, Multicore Flow, Rebilda LC, Ecusit, and Tetric Evo Ceram, showed more homogenous surface structures compared to GICs and restorative composites. Therefore, wear values of core build‐up materials not only differed widely but were higher than those of conventional restorative materials; yet, core build‐up materials showed advantageous surface structures. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009
Membrane autopsy to investigate CaCO3 scale formation in pilot‐scale, submerged membrane bioreactor treating calcium‐rich wastewater
Authors: Lee Mooseok , Kim Jeonghwan
Published: April 2009

BACKGROUND: Membrane scaling is an area of research interest because it can deteriorate membrane performance. The extent to which membrane scaling is produced varies depending upon the concentration of scale‐forming species such as calcium on the membrane surface. Bench‐scale tests have been conducted to better understand membrane scaling in submerged membrane reactors (MBR). However, relatively few studies of membrane scaling in pilot‐scale, submerged MBR have been reported. The objective of this study was to perform membrane autopsy work to analyze membrane scaling in a submerged MBR treating calcium‐rich wastewater.

RESULTS: Membrane autopsy work provided evidence that deposition of calcium carbonate (CaCO3) scale occurred on the membrane surface at the completion of pilot‐scale, submerged MBR operation. The CaCO3 scaling resulted in significant external fouling on the surface of the membrane. The membrane scaling increased the rejection of calcium with MF membranes. However, the level of CaCO3 scaling as internal fouling (in the pores) was almost negligible. This autopsy work also showed that aeration did not play a major role in controlling CaCO3 scaling at the membrane surface in a submerged MBR. Chemical cleaning using citric acid solution efficiently removed CaCO3 scale from the membrane. Combining citric acid with sodium hypochlorite pretreatment provided synergistic effects, further reducing CaCO3 scale formation.

CONCLUSION: The carbonate salt of calcium leads to precipitation resulting in surface fouling of membranes, and this cannot be removed physically by aeration in a submerged MBR treating calcium‐rich wastewater. It is necessary to combine properly‐selected cleaning strategies with submerged MBR treating wastewater containing a high potential for inorganic chemical precipitates. Copyright © 2009 Society of Chemical Industry
Production of vanillin from wheat bran hydrolyzates via microbial bioconversion
Authors: Di Gioia Diana , Sciubba Luigi , Ruzzi Maurizio , Setti Leonardo , Fava Fabio
Published: April 2009

BACKGROUND: Wheat bran contains a large amount of ferulic acid, which can be released through enzymatic hydrolysis and bioconverted into vanillin. A previous study has shown that ferulic acid purification from bran carbohydrates with the Amberlite® IRA 95 resin allowed an increased vanillin molar yield. In this work, alternative ferulic acid recovery methods were proposed and the possibility of exploiting the residual carbohydrate‐rich water phase was explored.

RESULTS: Ferulic acid was recovered from crude wheat bran hydrolyzate by: (i) a hydrophobic sorbent cartridge (ISOLUTE ENV+®): (ii) ethyl acetate extraction; and (iii) the resin previously employed. The highest recovery percentage (95%) was obtained with ISOLUTE ENV+®, which also allowed an interesting vanillin molar yield from ferulic acid bioconversion (75% from 0.5 mmol L−1 ferulic acid). The residual water phase was a good growth substrate for the microorganism operating the bioconversion. Cells grown on this matrix could efficiently bioconvert the recovered ferulic acid to vanillin

CONCLUSION: The possibility of efficiently recovering ferulic acid from wheat bran hydrolyzates, bioconverting it into vanillin, and valorizing the sugar‐rich exhausted water fraction was demonstrated in this work. The approach allowed the production of a value‐added fine‐chemical from a food‐industry by‐product. Copyright © 2009 Society of Chemical Industry
Effects of current density and electrode material on the dewaterability of the thickened activated sludge by electro‐flotation
Authors: Choi Young Gyun , Kim Seong Hong , Kim Hee Jun , Kim Yun Jung , Chung Tai Hak
Published: April 2009

BACKGROUND: Electro‐flotation (EF) could improve thickening and subsequent dewatering characteristics of activated sludge although the settling characteristics of the sludge were very poor. The objectives of this study were to evaluate the performance of EF in the thickening and dewatering of activated sludge and the effects of current density and electrode material on the dewaterability of the sludge.

RESULTS: The specific resistance to filtration (SRF) of the sludges thickened by EF was much lower than that by gravity sedimentation. The SRF of the thickened sludge decreased exponentially with increase of gas generation rate of the EF system. Gas generation rate could be controlled by varying the current density of the electrode. Degassing of the microbubbles by moderate mixing of the thickened sludge layer deteriorated the dewaterability of the sludge. Therefore, it is obvious that the gas bubbles entrapped in the thickened sludge play a key role in the observed dewaterability improvement. The effect of electrode material on the thickening and dewatering efficiency was trivial compared with the effect of current density of the electrode.

CONCLUSION: The EF system was quite promising as an alternative to gravity sedimentation for thickening of activated sludge and the dewaterability was also improved by microbubbles generated in the system. Copyright © 2009 Society of Chemical Industry
γH2AX marks the main events of the spermatogenic process
Authors: Blanco‐Rodríguez Josefa
Published: April 2009

Recent findings reveal that chromatin reorganization requires formation and repair of DNA double strand breaks (DSBs). Therefore, dynamic changes in chromatin structure taking place along the mitotic and the meiotic processes should be accompanied by histone H2AX phosphorylation and formation of γH2AX, a prominent event occurring at DSB sites. Accordingly, γH2AX has been detected at multiple developmental steps in adult germ cells. Nevertheless, no comprehensive study focusing on the main biological events occurring in the seminiferous epithelium has been carried out in mammals. Here I analyze H2AX phosphorylation in immunostained testis sections comparing PAS/cresyl violet counterstained, noncounterstained, and immuno‐fluorescence preparations and show several waves of H2AX phosphorylation/dephosphorylation coupled to various developmental phases of spermatogonia and spermatocytes as well as to spermatid differentiation. The combined detection of DNA replication or free 3′‐OH DNA ends highlight the possible significance of γH2AX at these locations. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
A novel inducible tyrosine kinase receptor to regulate signal transduction and neurite outgrowth
Authors: Alfa Ronald W. , Tuszynski Mark H. , Blesch Armin
Published: April 2009

Nervous system growth factor gene delivery can promote axonal growth and prevent cell death in animal models of CNS trauma and neurodegenerative diseases. The ability to regulate growth factor expression or signaling pathways downstream from growth factor receptors remains a desirable goal for in vivo gene transfer. To achieve precise pharmacological modulation of neurotrophin activity, we have generated a chimeric trkA receptor (ItrkA) by fusing the entire intracellular domain of the trkA high‐affinity NGF receptor to two intracellular, modified FK506 binding domains for the synthetic small molecule dimerization ligand AP20187. Rat PC12 cells were transduced with lentiviral vectors containing ItrkA and green fluorescent protein (GFP; via an internal ribosome entry site). Treatment of ItrkA‐expressing PC12 cells with AP20187 induced neurite outgrowth and differentiation in a time‐ and dose‐dependent fashion, with a half‐maximal response at a concentration of 1 nM AP20187. Seventy percent of cells responded to AP20187 by day 3. Western blots demonstrated that AP20187 treatment resulted in phosphorylation of Erk1/2 and Akt in ItrkA‐transduced PC12 cells but not in nontransduced, naïve cells. Phosphorylation levels were comparable to levels obtained with 50 ng/ml nerve growth factor (NGF). In addition, ItrkA lentiviral transduction of primary E15 dorsal root ganglion neurons significantly increased neurite growth three‐ to fourfold in the presence of AP20187 compared with control GFP transduced and naïve neurons. These results demonstrate that small ligand‐induced dimerization of the intracellular domain of trkA can efficiently simulate the biological activity of NGF and provide a means to regulate intracellular neurotrophin receptor signaling. © 2009 Wiley‐Liss, Inc.
The two‐hydrophobic domain tertiary structure of reticulon proteins is critical for modulation of β‐secretase BACE1
Authors: Kume Hideaki , Murayama Kiyoko S. , Araki Wataru
Published: April 2009

β‐Site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is a membrane‐bound protease that is essential for the production of β‐amyloid protein (Aβ). Given the crucial role of Aβ accumulation in Alzheimer's disease (AD), inhibition of BACE1 activity may represent a feasible therapeutic strategy in the treatment of AD. Recently, we and others identified reticulon 3 (RTN3) and reticulon 4‐B/C (RTN4‐B/C or Nogo‐B/C) as membrane proteins that interact with BACE1 and inhibit its ability to produce Aβ. In this study, we employed various mutants of RTN3 and RTN4‐C and C. elegans RTN to investigate the molecular mechanisms by which RTNs regulate BACE1. We found that RTN3 mutants lacking the N‐terminal or C‐terminal or loop domain as well as a RTN4‐C mutant lacking the C‐terminal domain bound to BACE1 comparably to wild‐type RTN3 and RTN4‐C. Furthermore, overexpression of wild‐type RTN3, RTN4‐C, and these RTN mutants similarly reduced Aβ40 and Aβ42 secretion by cells expressing Swedish mutant APP. C. elegans RTN, which has low homology to human RTNs, also interacted with BACE1 and inhibited Aβ secretion. In contrast, two RTN3 mutants containing deletions of the first or second potential transmembrane domains and an RTN3 swap mutant of the second transmembrane domain bound BACE1 but failed to inhibit Aβ secretion. Collectively, these results suggest that the two‐transmembrane‐domain tertiary structure of RTN proteins is critical for the ability of RTNs to modulate BACE1 activity, whereas N‐terminal, C‐terminal and loop regions are not essential for this function. © 2009 Wiley‐Liss, Inc.
Identification of major S‐nitrosylated proteins in murine experimental autoimmune encephalomyelitis
Authors: Bizzozero Oscar A. , Zheng Jianzheng
Published: April 2009

Nitrosative stress has been implicated in the pathophysiology of several CNS disorders, including multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). We have recently shown that protein nitrosothiols (PrSNOs) accumulate in the brain of MS patients, and there is indirect evidence that PrSNO levels are also increased in EAE. In this study we sought to identify the major PrSNOs in the spinal cord of EAE animals prepared by active immunization of C57/BL6 mice with MOG35–55 peptide. For this purpose, PrSNOs from control and EAE mice at various disease stages were derivatized with HPDP‐biotin, and the biotinylated proteins were isolated with streptavidin‐agarose. Proteins from total and streptavidin‐bound fractions were then analyzed by Western blotting using antibodies against the major S‐nitrosylated substrates of CNS tissue. With this approach we found that the proportion of S‐nitrosylated neurofilament proteins, NMDA receptors, α/β‐tubulin, β‐actin, and GAPDH is increased in EAE. Other potential substrates either were not S‐nitrosylated in vivo (HCN3, HSP‐72, CRMP‐2, γ‐actin, calbindin) or their S‐nitrosylation levels were unaltered in EAE (Na/K ATPase, hexokinase, glycogen phosphorylase). We also discovered that neuronal specific enolase is the major S‐nitrosylated protein in acute EAE. Given that S‐nitrosylation affects protein function, it is likely that the observed changes are significant to the pathophysiology of inflammatory demyelination. © 2009 Wiley‐Liss, Inc.
Specificity of the second messenger pathways involved in basic fibroblast growth factor‐induced survival and neurite growth in chick ciliary ganglion neurons
Authors: Gilardino Alessandra , Farcito Silvia , Zamburlin Pollyanna , Audisio Chiara , Lovisolo Davide
Published: April 2009

Basic fibroblast growth factor (bFGF) exerts multiple neurotrophic actions on cultured neurons from the ciliary ganglion of chick embryo, among them promotion of neuronal survival and of neurite outgrowth. To understand the specificity of the signal transduction cascades involved in the control of these processes, we used pharmacological inhibitors of the three main effectors known to act downstream of the bFGF receptor (FGFR): phospholipase Cγ (PLCγ), mitogen‐activated protein kinase (MAPK), and phosphatidylinositol 3‐kinase (PI3‐K). Neuronal survival was assessed at 24 and 48 hr; neurite growth was analyzed both on dissociated neurons and on explants of whole ganglia. Our data show that only the PI3‐K pathway is involved in the survival‐promoting effect of bFGF; on the other hand, all three effectors converge on the enhancement of neurite outgrowth, both on isolated neurons and in whole ganglia. © 2009 Wiley‐Liss, Inc.
Air temperature changes in the arctic from 1801 to 1920
Authors: Przybylak Rajmund , Vízi Zsuzsanna , Wyszyński Przemysław
Published: April 2009

In this paper, the results of an investigation into the thermal conditions in the Arctic in the period from 1801 to 1920 are presented. For this ‘early instrumental’ period limited meteorological data exist. Generally, the first meteorological stations in the Arctic were established in the second half of the 19th century and almost all of them were located in the coastal parts of Greenland. In order to get at least a rough idea of thermal conditions in the Arctic in the study period, data from different land and marine expeditions were collected. A total of 118 temperature series of monthly means have been gathered. Although the area and time periods covered by the data are variable, it is still possible to describe the general character of the temperature conditions.

The results show that the areally averaged Arctic temperature in the early instrumental period was 0.8 °C lower than the next 60‐year period (1861–1920). In comparison to present‐day conditions, winter and autumn were significantly colder (winter by 1.6 °C and autumn by 0.9 °C) than were summer (colder by 0.4 °C) and spring (colder by only 0.2 °C). The air temperature in the real Arctic during the first International Polar Year (IPY) was, on average, colder than today by 1.0–1.5 °C. Winter was exceptionally cold with the average temperature being lower by more than 3 °C in all months except February. On the other hand, spring (March–May) was slightly warmer than today, and April was exceptionally warm (1.1 °C above present norm).

The temperature differences calculated between historical and modern mean monthly temperatures show that majority of them lie within one standard deviation (SD) from present long‐term mean. Thus, it means that the climate in the early instrumental period was not as cold as some proxy data suggest. Copyright © 2009 Royal Meteorological Society
Downscaling hydroclimatic changes over the Western US based on CAM subgrid scheme and WRF regional climate simulations
Authors: Qian Yun , Ghan Steven J. , Leung L. Ruby
Published: April 2009

This study examines two dynamical downscaling methods, a subgrid parameterization and a regional climate model, to compare their impacts on simulating orographic precipitation and surface hydrology in mountain regions. A global climate model was first applied at 1° × 1.25° grid resolution with a subgrid orographic precipitation scheme. The global simulations were then used to drive a regional climate model at 15‐km grid resolution over the Western United States. By comparing the global and regional simulations for two 10‐year periods, 1993–2003 and 2039–2049, this study assesses the two downscaling methods in the context of simulating both the present climate and climate change signals, and the implications of the relatively short simulation length to investigate differences in current and future climate simulated by the models are discussed.

The model results show that improving the representation of surface topography through higher spatial resolution or a subgrid method has a large impact on the simulations. Both the subgrid scheme and the regional model significantly improved the simulation of snowpack in the mountains. The spatial distributions of precipitation and snowpack are generally consistent between the subgrid and regional simulations, since they were driven by the same large‐scale circulation from the global simulations. However, because rain‐shadow effects are not represented in the subgrid scheme, the regional simulations produced much more realistic spatial variability in precipitation and snowpack than the subgrid simulations in narrow mountain ranges.

In the climate change experiments, both downscaling procedures preserved the large‐scale patterns of temperature and precipitation changes in the global simulations. However, the regional simulations show larger changes in precipitation and snowpack along the coastal mountains than the subgrid simulations. This is attributed to the fact that the regional model explicitly simulates the interactions of atmospheric circulation and the underlying topography, so changes in wind directions with respect to the orientations of the mountains may lead to changes in orographic precipitation that cannot be explained by changes in atmospheric temperature and moisture alone. Hence differences between the precipitation changes simulated by the regional model and the subgrid method are larger in narrow mountains such as the Cascades and the Sierra Nevada because the subgrid method does not account for the influence of mountain orientations at the subgrid scale. As precipitation is an important driver of surface hydrological processes, differences between the precipitation changes simulated by the two methods lead to important differences in the surface hydrological processes under climate change. Copyright © 2009 Royal Meteorological Society
Additive effects of hyperbaric oxygen and platelet‐derived growth factor‐BB in chondrocyte transplantation via up‐regulation expression of platelet‐derived growth factor‐β receptor
Authors: Yuan Li‐Jen , Niu Chi‐Chien , Lin Song‐Shu , Chan Yi‐Sheng , Yang Chuen‐Yung , Chen Wen‐Jer , Ueng Steve W.N.
Published: April 2009

The present study investigated the effects of hyperbaric oxygen (HBO) and platelet‐derived growth factor‐BB (PDGF‐BB) in chondrocyte transplantation. In vitro, chondrocytes were treated with HBO, PDGF‐BB, and HBO combined with PDGF‐BB (H+P). Cell growth was analyzed using cell counting, MTT assay, and FACS analysis. mRNA expression of the PDGF‐α receptor (PDGFR‐α) and β receptor (PDGFR‐β) was detected by RT‐PCR. Protein expression of PDGFR‐β was detected by Western blotting. In vivo, chondrocytes and PDGF‐BB were suspended in alginate as a transplantation system. Cartilage defects were grafted with this system and with or without HBO treatment. Released PDGF‐BB concentration was quantified by ELISA. After 8 weeks, animals were sacrificed and the repaired tissues were examined. In vitro data suggested that each treatment increased cell growth via the up‐regulated mRNA expression of PDGFR‐α and increased cell accumulation in the S‐phase. The H+P treatment was more additive in cell growth and in mRNA and protein expression of PDGFR‐β than HBO or PDGF‐BB. In vivo results suggested that PDGF‐BB delivery lasted for more than 5 weeks. Scoring results showed that each treatment significantly increased the cartilage repair. Safranin‐O and type II collagen staining confirmed the hyaline‐like cartilage regeneration in the repaired tissues. In situ up‐regulation of PDGFR‐β expression partially explains the additive effect of H+P treatment in cartilage repair. Accordingly, H+P offers a potential treatment method for cartilage repair. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1439–1446, 2009
Drilling and microfracture lead to different bone structure and necrosis during bone‐marrow stimulation for cartilage repair
Authors: Chen Hongmei , Sun Jun , Hoemann Caroline D. , Lascau‐Coman Viorica , Ouyang Wei , McKee Marc D. , Shive Matthew S. , Buschmann Michael D.
Published: April 2009

Bone marrow stimulation is performed using several surgical techniques that have not been systematically compared or optimized for a desired cartilage repair outcome. In this study, we investigated acute osteochondral characteristics following microfracture and comparing to drilling in a mature rabbit model of cartilage repair. Microfracture holes were made to a depth of 2 mm and drill holes to either 2 mm or 6 mm under cooled irrigation. Animals were sacrificed 1 day postoperatively and subchondral bone assessed by histology and micro‐CT. We confirmed one hypothesis that microfracture produces fractured and compacted bone around holes, essentially sealing them off from viable bone marrow and potentially impeding repair. In contrast, drilling cleanly removed bone from the holes to provide access channels to marrow stroma. Our second hypothesis that drilling would cause greater osteocyte death than microfracture due to heat necrosis was not substantiated, because more empty osteocyte lacunae were associated with microfracture than drilling, probably due to shearing and crushing of adjacent bone. Drilling deeper to 6 mm versus 2 mm penetrated the epiphyseal scar in this model and led to greater subchondral hematoma. Our study revealed distinct differences between microfracture and drilling for acute subchondral bone structure and osteocyte necrosis. Additional ongoing studies suggest these differences significantly affect long‐term cartilage repair outcome. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1432–1438, 2009
Adsorbed states of substituted α‐aminophosphinic acids on a silver electrode surface: comparison with a colloidal silver substrate
Authors: Podstawka Edyta , Kudelski Andrzej , Dra̧g M. , Oleksyszyn J. , Proniewicz Leonard M.
Published: April 2009

We investigated the interfacial structures of various aromatic (each compound contains one or two phenyls) di‐α‐amino (L1–L3) and α‐amino‐α‐hydroxyphosphinic (L4–L6) acids immobilized onto an electrochemically roughened silver electrode surface in an aqueous solution using surface‐enhanced Raman scattering (SERS). These structures were compared to those on a colloidal silver surface to determine the relationship between adsorption strength and geometry. The presence of an enhanced ν19a ring band in the SERS spectra of L6, L2, and L3 on the electrode indicated that the benzene rings of those molecules interact with the electrode surface through localized CC bond(s). We observed significant band broadening of the benzene ring modes for all α‐hydroxyphosphinic acids on both substrates, except for L1 deposited onto the electrode surface. This suggests the possibility of direct interaction between the ring and Ag, although the benzene ring–surface π overlap is weaker for the colloidal silver than for the Ag electrode. The downward shift in wavenumber and alternations in the enhancement of a ν12 ring band indicate a general increase of tilt angle on both silver substrates in the order L3 < L4 < L5 < L6. The altered enhancement of the bands due to the vibrations of the NH2 and OPO fragments, a finding observed on both silver substrates, strongly suggests that the groups interact with different strength and geometry with these substrates. Copyright © 2009 John Wiley & Sons, Ltd.
Pathological analysis after neoadjuvant chemoradiotherapy for esophageal carcinoma: The rotterdam experience
Authors: van Meerten E. , van der Gaast A. , Tilanus H.W. , Poley J.W. , Muller K. , van Dekken H.
Published: April 2009

Multimodality treatment is increasingly used in the treatment for esophageal cancer. We determined the tumor regression grade after preoperative chemoradiation and correlated the effect of specific pathologic and clinical findings to overall survival. For this purpose esophageal biopsies and surgical specimens of 67 patients treated with neoadjuvant paclitaxel and carboplatin concurrent with radiotherapy were reviewed. Neoadjuvant chemoradiotherapy led to a significant downstaging. Complete tumor regression was found in 24% of the patients resulting in a trend towards better survival. It was found more frequently in poorly differentiated tumors. Patients with pre‐treatment nodal involvement, assessed by endoscopic ultrasound, had a significantly worse survival compared to patients without. Contrastingly, this was not found for post‐treatment nodal involvement, as determined by pathological examination, speculating that survival is more determined by (submicroscopic) distant disease, than by locoregional tumor cells. J. Surg. Oncol. 2009;100:32–37. © 2009 Wiley‐Liss, Inc.
Expression of extracellular matrix molecules in brain metastasis
Authors: Yoshida Seiichi , Takahashi Hideaki
Published: April 2009

Background and Objectives

The objectives of this study were to investigate the role of growth factors and matrix metalloproteinases in the brain metastasis.

Methods

Tumors from 40 patients with brain metastasis (30 lung cancer, 10 breast cancer) were studied to investigate the expression‐patterns of EGFR, MT1‐MMP, MMP7, and CD44 using the immunostaining and RT ‐PCR analysis.

Results

EGFR immunostaining was detected in 92% (23/25) and 70% (7/10) of brain metastasis from lung adenocarcinoma and breast cancer, respectively. MT1‐MMP immunostaining was also detected in 80% (20/25) and 50% (5/10) of brain metastasis from lung adenocarcinoma and breast cancer, respectively. EGFR mRNA was detected in 83.3% (25/30) and 70% (7/10) of brain metastasis from lung cancer and breast cancer, respectively. MT1‐MMP mRNA was detected in 73.3% (22/30) specimens of brain metastasis from lung cancer, and only 13.3% (4/30) specimens of these patients expressed MMP7 mRNA.

Conclusions

The high expression of EGFR and MT1‐MMP indicates that a extracellular matrix remodeling may be playing an important role in brain metastasis. J. Surg. Oncol. 2009;100:65–68. © 2009 Wiley‐Liss, Inc.
Medicinal chemistry and therapeutic potential of muscarinic M3 antagonists
Authors: Peretto Ilaria , Petrillo Paola , Imbimbo Bruno P.
Published: April 2009

Muscarinic acetylcholine receptors belong to the G‐protein‐coupled receptors family. Currently five different receptor subtypes have been identified and cloned. M3 receptor subtypes are coupled to Gqfamily proteins and increase phosphatidyl inositol hydrolysis and calcium release from internal stores. They are widely distributed both in the central nervous system and in the periphery. At the central level, M3 receptor subtypes are involved in modulation of neurotransmitter release, temperature homeostasis, and food intake, while in the periphery they induce smooth muscle contraction, gland secretion, indirect relaxation of vascular smooth muscle, and miosis. The main therapeutic applications of M3 antagonists include overactive bladder (OAB), chronic obstructive pulmonary disease (COPD), and pain‐predominant irritable bowel syndrome (IBS). The introduction of selective M3 antagonists has not improved clinical efficacy compared with the old non‐selective antimuscarinics but has reduced the rate of adverse events mediated by the blockade of cardiac M2 receptors (tachycardia) and central M1 receptors (cognitive impairment). Improved tolerability has been obtained also with controlled release or with inhaled formulations. However, there is still a need for safer M3 antagonists for the treatment of COPD and better‐tolerated and more effective compounds for the therapy of OAB. New selective muscarinic M3 antagonists currently in early discovery and under development have been designed to address these issues. However, as M3 receptors are widely located in various tissues including salivary glands, gut smooth muscles, iris, and ciliary muscles, further clinical improvements may derive from the discovery and the development of new compounds with tissue rather than muscarinic receptor subtype selectivity. © 2009 Wiley Periodicals, Inc. Med Res Rev, 29, No. 6, 867–902, 2009
Supermicrosurgical lymphaticovenular anastomosis and lymphaticovenous implantation for treatment of unilateral lower extremity lymphedema
Authors: Demirtas Yener , Ozturk Nuray , Yapici Oktay , Topalan Murat
Published: April 2009

Recent supermicrosurgical techniques have developed the possibility for vascular anastomosis of smaller vessels and it is now safe and sound to perform precise anastomoses between lymphatics and venules. Reported here is the 2 years experience on supermicrosurgical lymphaticovenular anastomosis and/or lymphaticovenous implantation combined with a nonoperative physical therapy for treatment of lower extremity lymphedema. Microlymphatic surgery was performed in 42 patients with unilateral lower extremity lymphedema. Thirty patients were women and 12 were men with a mean age of 34. Lymphaticovenular anastomoses were performed in 37 patients with an average of 2.5 anastomoses per patient, and lymphaticovenous implantations were made in 36 patients with an average of 2.4 implantations per patient. The lymphatics that were larger than 0.3 mm were anastomosed to venules with supermicrosurgical technique. Lymphaticovenous implantation technique was used for thinner lymphatics in a particular incision. Postoperatively, 18 patients used continuous compressive garments, 9 patients used garments but discontinued after 6 months, and no compression was used in 9 patients. The results of surgery were assessed both clinically with volume measurements and by lymphoscintigraphy and were classified as good, moderate, or ineffective. The mean decrease in the volume of the edema was 59.3% at an average follow‐up of 11.8 months. Six outcomes were classified as ineffective, eight outcomes as moderate, and 28 outcomes as good. Supermicrosurgical lymphaticovenular anastomosis and/or lymphaticovenous implantation seems to be highly beneficial, especially in the early stages of peripheral lymphedema and may be offered as the treatment of choice in selected patients. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.
Transient solution for multilayered poroviscoelastic media obtained by an exact stiffness matrix formulation
Authors: Mesgouez A. , Lefeuve‐Mesgouez G.
Published: April 2009

The authors propose a semi‐analytical approach to studying wave propagation in multilayered poroviscoelastic grounds due to transient loads. The theoretical development is based on the exact stiffness matrix method for the Biot theory coupled with a matrix conditioning technique. It is developed in the wavenumber frequency domain after a Fourier transform on the surface space variables and the time variable. The usual methods yield a poorly conditioned numerical system. This is due in particular to the presence of mismatched exponential terms. In this article, increasing exponential terms are eliminated and only decreasing exponential terms remain. Consequently, the method can be applied to a large field of configurations without restriction concerning high frequencies, large Fourier transform parameters or large layer thicknesses. Validation and efficiency of the method are discussed. Effects of layering show that the layer impedance influence on solid and fluid displacements. Moreover, this approach can be of interest for the validation of numerical tools. Copyright © 2009 John Wiley & Sons, Ltd.
An adaptive species conservation genetic algorithm for multimodal optimization
Authors: Li Jian‐Ping , Wood Alastair S.
Published: April 2009

This paper introduces an adaptive species conservation genetic algorithm (ASCGA) by defining a species with three parameters: species seed, species radius and species boundary fitness. A species is defined as a group of individuals that have similar characteristics and that are dominated by the best individual in the species, called the species seed. Species radius defines the species' upper boundary and the species boundary fitness is the lowest value of fitness in the boundary. Some heuristic algorithms have been developed to adjust these parameters and an ASCGA has been proposed to solve multimodal optimization problems. With heuristic techniques, ASCGA can automatically adjust species parameters and allow the species to adapt to an optimization problem. Experimental results presented demonstrate that the proposed algorithm is capable of finding the global and local optima of test multimodal optimization problems with a higher efficiency than the methods from the literature. ASCGA has also successfully found a significantly different solution of a 25‐bar space truss design and identified 761 local solutions of the 2‐D Shubert function. Copyright © 2009 John Wiley & Sons, Ltd.
Factorial design of nanosized polyisoprene synthesis via differential microemulsion polymerization
Authors: Suppaibulsuk Bunthita , Prasassarakich Pattarapan , Rempel Garry L.
Published: April 2009

The synthesis of nanosized polyisoprene latex was carried out by differential microemulsion polymerization using 2, 2′‐Azoisobutyronitrile (AIBN) initiator system under various reaction conditions. A $2_V^{5 - 1} $ fractional factorial experimental design was applied to study the effects of reaction variables: amount of initiator and surfactant, monomer‐to‐water ratio, reaction temperature, and stirring speed on rubber particle size and monomer conversion. The analysis of the results from the design showed the main effects on the observed response and the amount of initiator, reaction temperature and stirring speed in the range of the test had significant effects on polyisoprene particle size. The significant effects on monomer conversion were reaction temperature, stirring speed, and interaction between reaction temperature and stirring speed in the range of the test. The optimum conditions gave highest monomer conversion of 90% and average particle size of polyisoprene of 27 nm. The nanosized polyisoprene was also characterized by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Copyright © 2009 John Wiley & Sons, Ltd.
Polyimide/polyoxometalate copolymer thin films: synthesis, thermal and dielectric properties
Authors: Tan Lin , Liu Shumei , Zeng Fang , Ling Zhiyuan , Zhao Jianqing
Published: April 2009

A mono‐lancunary keggin‐type decatungstosilicate (SiW11) polyoxometalate (POM) modified by γ‐aminopropyltriethoxysilane (KH550) was incorporated into polyimide (PI) through copolymerization. Nuclear magnetic resonance (NMR), fourier transition infrared spectroscopy (FTIR), and wide angle X‐ray diffraction (WAXD) were used to characterize the structure and composition of the polyoxometalate–organosilane hybrid (SiW11KH550) and PI/SiW11KH550 copolymers. The differential scanning calorimetry (DSC) studies indicate that the glass transition temperature (Tg) of PI/SiW11KH550 copolymers increases from 330°C (for neat PI) to 409°C (for the copolymer sample with 10 wt% of SiW11KH550). Dielectric measurement showed that both the dielectric constant and the dielectric loss for the copolymer thin films decreased with the increase in SiW11KH550 content, and the dielectric constant and dielectric loss values decreased to 2.1 and 3.54 × 10−3, respectively, for the copolymer sample with 10 wt% of SiW11KH550. The incorporation of SiW11KH550 into polymer matrices is a promising approach to prepare PI films with a low dielectric constant and low dielectric loss. Copyright © 2009 John Wiley & Sons, Ltd.
Progressive neurocognitive impairment in young adult survivors of childhood acute lymphoblastic leukemia
Authors: Harila Marika J. , Winqvist Satu , Lanning Marjatta , Bloigu Risto , Harila‐Saari Arja H.
Published: April 2009

Background

Despite the extensive literature on neuropsychological sequelae after treatment of childhood acute lymphoblastic leukemia (ALL), the very‐long‐term neurocognitive outcome of the survivors is poorly studied. We assessed neuropsychological functioning in a population‐based cohort of young adult childhood ALL survivors.

Procedure

Neuropsychological testing was performed on 64 survivors an average of 20 years after the diagnosis. The test battery included verbal intelligence quotient (VIQ) and performance intelligence quotient (PIQ), memory function, orientation and attention as well as motor performance. Cranial irradiation had been administered to 44 survivors as part of ALL treatment, whereas 20 survivors had been treated solely with chemotherapy. A control group consisted of 45 healthy young adults. Earlier neuropsychological test results of 45 of the survivors were available for comparison.

Results

The ALL survivors attained significantly lower test scores than the controls in all the neuropsychological function areas. The mean VIQ test scores were 91, 100, and 109 (P < 0.001), and the mean PIQ test scores 100, 111, and 118 (P < 0.001) for the irradiated survivors, non‐irradiated survivors and controls, respectively. Memory and motor functions were impaired among the irradiated survivor group compared with the controls. A significant decline in PIQ and VIQ test scores was observed in the irradiated survivor group during the follow‐up period, but only in VIQ in the non‐irradiated group.

Conclusions

Survivors of childhood ALL suffer from long‐lasting progressive neuropsychological impairment, especially when treatment includes cranial irradiation. Pediatr Blood Cancer 2009;53:156–161. © 2009 Wiley‐Liss, Inc.
Lactic acidosis and hypoglycemia with ALL relapse following engrafted bone marrow transplant
Authors: Luscri Nathan , Mauer Michael , Sarafoglou Kyriakie , Moran Antoinette , Tolar Jakub
Published: April 2009

Lactic acidosis together with hypoglycemia in the face of hematologic malignancy is a grave development. A 7‐year‐old male with pre‐B‐cell ALL following hematopoietic cell transplant was admitted to our hospital in his second relapse. On hospital days 4 and 5, he developed refractory hypoglycemia, lactic acidosis, central respiratory failure, and acute renal failure. Bicarbonate infusion, B vitamins, and hemodialysis were not effective. Care was withdrawn on hospital day 9. Further understanding of the mechanisms that cause the combined onset of lactic acidosis and hypoglycemia will help clinicians in implementing timely therapies that may reduce mortality. Pediatr Blood Cancer 2009;53:223–225. © 2009 Wiley‐Liss, Inc.
A simple isocratic HPLC method for the simultaneous determination of curcuminoids in commercial turmeric extracts
Authors: Wichitnithad Wisut , Jongaroonngamsang Nutthapon , Pummangura Sunibhond , Rojsitthisak Pornchai
Published: April 2009

Introduction

Turmeric (Curcuma longa) extracts contain three curcuminoids (curcumin, desmethoxycurcumin and bisdesmethoxycurcumin) as major bioactive substances. Previously reported HPLC‐UV methods for the determination of curcuminoids have several disadvantages, including unsatisfactory separation times, poor resolution and/or complicated solvent mixtures with gradient elution.

Objective

To develop a simple isocratic HPLC‐UV method for the simultaneous determination of individual curcuminoids for the quality control of turmeric extracts.

Methodology

The sample was prepared by dissolving the extract in acetonitrile and subsequently diluting with 50% acetonitrile. This solution was analysed by reverse‐phase chromatography on an Alltima C18column with isocratic elution of acetonitrile and 2% v/v acetic acid (40:60, v/v) at a flow rate of 2.0 mL/min, a column temperature of 33°C, and UV detection at 425 nm. The method was validated and applied for quantification of individual curcuminoids in commercial turmeric extracts.

Results

The method allowed simultaneous determination of curcumin, desmethoxycurcumin and bisdesmethoxycurcumin in the concentration ranges of 10–60, 4–24 and 0.5–3.0 µg/mL, respectively. The limits of detection and quantification were, respectively, 0.90 and 2.73 µg/mL for curcumin, 0.84 and 2.53 µg/mL for desmethoxycurcumin and 0.08 and 0.23 µg/mL for bisdesmethoxycurcumin, and the percentage recoveries were, respectively, 99.16–101.75 (%RSD ≤ 1.11%), 99.50–101.01 (%RSD ≤ 1.74%) and 99.67–101.92 (RSD ≤ 1.31%).

Conclusion

The method was found to be simple, accurate and precise and is recommended for routine quality control analysis of turmeric extracts containing the three curcuminoid compounds as the main principles in the herb. Copyright © 2009 John Wiley & Sons, Ltd.