bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oscillatory behaviour in Galvanostatic Formaldehyde Oxidation on Nanostructured Pt/Glassy Carbon Model Electrodes
Authors: Seidel Yvonne E. , Jusys Zenonas , Lindström Rakel W. , Stenfeldt Marie , Kasemo Bengt , Krischer Katharina 
Published: April 2010

AbstractThe electrocatalytic oxidation of formaldehyde, which results in CO2 and HCOOH formation, was investigated under galvanostatic conditions on nanostructured Pt/glassy carbon (GC) electrodes fabricated by employing colloidal lithography (CL). The measurements were performed on structurally well‐defined model electrodes of different Pt surface coverages under different applied currents (current densities) and at constant electrolyte transport in a thin‐layer flow cell connected to a differential electrochemical mass spectrometry (DEMS) setup to monitor the dynamic response of the reaction selectivity under these conditions. Periodic oscillations of the electrode potential and the CO2 formation rate appear not only for a continuous Pt film, but also for the nanostructured Pt/GC electrodes when a critical current density is exceeded. The critical current density for achieving regular osillation patterns increased with decreasing Pt nanodisk density. Lower oscillation frequencies of the electrode potential and lower CO2 formation rate for nanostructured Pt/GC electrodes compared to continuous Pt film at similar applied current densities suggest that transport processes play an essential role. Moreover, from the simple periodic response of the nanostructured electrodes it follows that all individual Pt disks in the array oscillate in synchrony. This result is discussed in terms of the different modes of spatial coupling present in the system: global coupling, migration coupling and mass transport of the essential chemical species, and the coverage of corresponding adsorbates.
Spectrophotometric and chemometric determination of hydrochlorothiazide and spironolactone in binary mixture in the presence of their impurities and degradants
Authors: Hegazy Maha A. , Metwaly Fadia H. , Abdelkawy M. , Abdelwahab Nada S. 
Published: April 2010

AbstractHydrochlorothiazide (HCT) and spironolactone (SPR) are mostly co‐formulated in antihypertensive formulations. Several methods have been developed and validated for their determination; these methods include spectrophotometric and chemometric‐assisted spectrophotometric methods. The developed spectrophotometric methods were isosbestic point (ISO) and ratio subtraction (RS) methods. The absorbance values at 232.4 (λiso1) and 257.6 nm (λiso2) were used for determination of the total mixture concentration, while HCT could be directly determined at 317.2 nm (λmax) and by subtraction SPR concentration could be obtained. Also SPR concentration could be calculated by RS method using the absorbance at 243.8 nm (λmax). A wavelength selection method based on genetic algorithm (GAs) was developed and compared to the conventional partial least squares method (PLS). In this method, several parameters were adjusted and the optimum parameter settings were determined using experimental design. The developed chemometric methods were successfully applied for the determination of the HCT and SPR, as well as for determination of their impurities and degradation products. The proposed methods were successfully applied for determination of HCT and SPR in commercial tablets and they were statistically compared to each other and to the reported method. No significant difference was found, providing their accuracy and precision. Copyright © 2010 John Wiley & Sons, Ltd.
Development and validation of spectrofluorimetric method for determination of haloperidol in pharmaceutical dosage forms
Authors: Rahman Nafisur , Siddiqui Sana 
Published: April 2010

AbstractA simple, sensitive, and accurate spectrofluorimetric method has been developed for the determination of haloperidol in pharmaceutical preparations. The present method is based on the formation of an ion‐pair complex between haloperidol and alizarin red S at pH 3.4 which is extractable with chloroform. The ion‐pair complex exhibits maximum fluorescence intensity at 564 nm with excitation at 466 nm. The reaction conditions were optimized to obtain maximum fluorescence intensity. The relation between the fluorescence intensity and concentration was found to be linear over the range 0.8–20 µg/mL with detection limit of 0.08 µg/mL. The method was successfully employed for quantitation of the active ingredient haloperidol in pharmaceutical preparations. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference between the methods compared in terms of accuracy and precision. Copyright © 2010 John Wiley & Sons, Ltd.
Early development of medaka Oryzias latipes muscles as revealed by transgenic approaches using embryonic and larval types of myosin heavy chain genes
Authors: Ono Yosuke , Kinoshita Shigeharu , Ikeda Daisuke , Watabe Shugo 
Published: April 2010

AbstractWe cloned three full‐length cDNAs encoding myosin heavy chains (MYHs) previously found to be expressed in embryos or larvae of medaka Oryzias latipes. Based on cDNA sequence information, the three medaka MYH genes, mMYHemb1, mMYHL1 and mMYHL2, were localized on the chromosomes. In vivo promoter assay using the gene encoding green or red fluorescent protein and linked to the 5′‐flanking region of mMYH demonstrated that the transcripts of fast‐type mMYHemb1, first expressed in embryos but belonging to the adult type in phylogenetic analysis, were located in the horizontal myoseptum. On the other hand, embryonic fast‐type mMYHL1 and mMYHL2 were expressed in the whole myotomes. Interestingly, cells expressing mMYHemb1 were localized together with engrailed, and cyclopamine, which blocks hedgehog signaling, inhibited mMYHemb1 expression as well as the formation of the horizontal myoseptum, suggesting that muscle pioneer cells express mMYHemb1 as a key protein in the formation of the horizontal myoseptum. Developmental Dynamics 239:1807–1817, 2010. © 2010 Wiley‐Liss, Inc.
Gli2 activator function in preosteoblasts is sufficient to mediate ihh‐dependent osteoblast differentiation, whereas the repressor function of Gli2 is dispensable for endochondral ossification
Authors: Kesper Dörthe Andrea , Didt‐Koziel Lydia , Vortkamp Andrea 
Published: April 2010

AbstractSignaling of Indian hedgehog (Ihh), one of the key regulators of endochondral ossification is mediated by transcription factors of the Gli family, Gli1, Gli2, and Gli3. Gli3 and to a lesser extent Gli2 can be proteolytically processed into short repressor proteins. Upon Ihh signaling, processing is inhibited and the full‐length proteins function as activators of transcription. Gli3 has been shown to mainly act as a repressor of Ihh target genes in chondrocytes, but the role of other Gli isoforms is less clear. Analyzing mouse mutants deficient forIhh;Gli2orGli3;Gli2, we show here that the Gli2 repressor has no detectable function in chondrocyte or osteoblast differentiation. Instead, Gli2 seems to act as an activator to fully induce the expression of Ihh target genes in skeletal tissues. Furthermore, we show that, in the absence of Gli3, the activator function of Gli2 is sufficient to induce Ihh‐dependent osteoblast differentiation. Developmental Dynamics 239:1818–1826, 2010. © 2010 Wiley‐Liss, Inc.
Dynamic expression pattern of Sonic hedgehog in developing cochlear spiral ganglion neurons
Authors: Liu Zhiyong , Owen Thomas , Zhang Lingli , Zuo Jian 
Published: April 2010

AbstractSonic hedgehog (Shh) signaling plays important roles in the formation of the auditory epithelium. However, little is known about the detailed expression pattern of Shh and the cell sources from which Shh is secreted. By analyzing ShhCreEGFP/+ mice, we found that Shh was first expressed in all cochlear spiral ganglion neurons by embryonic day 13.5, after which its expression gradually decreased from base to apex. By postnatal day 0, it was not detected in any spiral ganglion neurons. Genetic cell fate mapping results also confirmed that Shh was exclusively expressed in all spiral ganglion neurons and not in surrounding glia cells. The basal‐to‐apical wave of Shh decline strongly resembles that of hair cell differentiation, supporting the idea that Shh signaling inhibits hair cell differentiation. Furthermore, this ShhCreEGFP/+ mouse is a useful Cre line in which to delete floxed genes specifically in spiral ganglion neurons of the developing cochlea. Developmental Dynamics 239:1674–1683, 2010. © 2010 Wiley‐Liss, Inc.
Identification of germ plasm‐associated transcripts by microarray analysis of Xenopus vegetal cortex RNA
Authors: Cuykendall Tawny N. , Houston Douglas W. 
Published: April 2010

AbstractRNA localization is a common mechanism for regulating cell structure and function. Localized RNAs in Xenopus oocytes are critical for early development, including germline specification by the germ plasm. Despite the importance of these localized RNAs, only approximately 25 have been identified and fewer are functionally characterized. Using microarrays, we identified a large set of localized RNAs from the vegetal cortex. Overall, our results indicate a minimum of 275 localized RNAs in oocytes, or 2–3% of maternal transcripts, which are in general agreement with previous findings. We further validated vegetal localization for 24 candidates and further characterized three genes expressed in the germ plasm. We identified novel germ plasm expression for reticulon 3.1, exd2 (a novel exonuclease‐domain encoding gene), and a putative noncoding RNA. Further analysis of these and other localized RNAs will likely identify new functions of germ plasm and facilitate the identification of cis‐acting RNA localization elements. Developmental Dynamics 239:1838–1848, 2010. © 2010 Wiley‐Liss, Inc.
Effect of Pore Structure on the Nitridation of Mesoporous Silica with Ammonia
Authors: Hayashi Fumitaka , Ishizu Ken‐ichi , Iwamoto Masakazu 
Published: April 2010

AbstractVarious mesoporous silicas [MCM‐41(M41), SBA‐15(SBA15), MCM‐48(M48)] and silica gel were nitrided with ammonia in a plug‐flow reactor at 1273 K. The nitrogen contents of various (oxy)nitrides obtained were increased with the amount of ammonia supplied per sample weight. The nitridation rates of silica samples were not changed with the pore sizes of the samples but with the pore structures. They were dependent on the surface areas of the parent silicas. The maximum contents of nitrogen in nitrided M41s, SBA15, M48, and silica gel were ca. 38, 35, 39, and 21 wt.‐%, respectively, which indicates the great difference between the reactivity of the mesoporous silicas and silica gel. 29Si NMR and X‐ray photoelectron spectroscopy also supported the progress in almost complete nitridation of the former samples. The XRD and the FE‐SEM measurements revealed that the mesoporous (oxy)nitrides maintained the original 2D hexagonal or 3D cubic mesopore structures and particle morphology. Nitrogen sorption analysis showed that the pore diameters, the surface areas, and the primary mesopore volumes were varied with the nitridation degrees and the types of pore structures but there occurred no destruction of pore structures. Finally, the stabilities of the silicon (oxy)nitrides prepared were studied. The pore structures and nitrogen contents remained essentially unchanged upon storage under a nitrogen atmosphere, immersion in 1‐buthanol or toluene, or by heating under H2 flow at 1073 K. Heating samples under O2 flow at 1073 K resulted in the collapse of the pore structures and a decrease in nitrogen content.
Fused Silacarbacycles Containing a Silole Unit: 1,2‐Hydroboration and 1,1‐Organoboration of Alkynyl(vinyl)silanes
Authors: Wrackmeyer Bernd , Tok Oleg L. , Klimkina Elena V. , Milius Wolfgang 
Published: April 2010

AbstractThe reaction of various alkynyl(vinyl)silanes containing two alkynyl groups with 9‐borabicyclo[3.3.1]nonane (9‐BBN) proceeds by regioselective 1,2‐hydroboration of the vinyl group in the first step, followed by two intramolecular 1,1‐organoboration reactions to afford 1,6‐disilapentalene derivatives, fused silacarbacycles with a silole unit. Similarly, the analogous reaction of an alkynyl(allyl)silane gives a 1,7‐disilaindene derivative. The products were characterized by multinuclear magnetic resonance (1H, 11B, 13C and 29Si NMR) in solution and in two cases by X‐ray structural analysis in the solid state.
Synthesis of (+)‐ and (–)‐Gossonorol and Cyclisation to Boivinianin B
Authors: Abecassis Keren , Gibson Susan E. 
Published: April 2010

AbstractThe first enantioselective synthesis of gossonorol has been achieved in good overall yield and excellent enantioselectivity, demonstrating the utility of a novel approach to enantiopure tertiary benzylic alcohols. Epoxidation of enantiopure gossonorol followed by acid‐catalysed cyclisation gave a diastereoisomeric mixture of boivinianin B,typical of the diastereoisomeric mixtures of this compound found in nature. Separation of the diastereoisomers and determination of their enantiopurity revealed that the stereochemical integrity of the benzylic alcohol of gossonorol had been preserved during the epoxidation/cyclisation reaction.
The inter‐ and intra‐operator variability in manual spot segmentation and its effect on spot quantitation in two‐dimensional electrophoresis analysis
Authors: Millioni Renato , Sbrignadello Stefano , Tura Andrea , Iori Elisabetta , Murphy Ellen , Tessari Paolo 
Published: April 2010

AbstractSeparation of complex mixtures of proteins by 2‐DE is a fundamental component of current proteomic technology. Quantitative analysis of the images generated by digitization of such gels is critical for identifying alterations in protein expression within a given biological system. Software packages are designed for this purpose. The accurate definition of protein spot boundaries, using a suitable method of image segmentation, is a key requirement for image analysis. It is often necessary for operators to intervene manually to correct mistakes in spot segmentation; therefore operator subjectivity and differences in ability can weaken the analysis. We estimated the error in spot quantification after manual spot segmentation, which was performed by different operators, using two different software packages. Our results clearly show that this operation was associated with significant inter‐ and intra‐variability and an overestimation of subsequent spot intensity, especially when spots were weak. For comparative studies, we suggest separately analysing spots which have been manually segmented by imposing a requirement for at least a threefold difference in spot intensity in addition to use of statistical tests.
Climate change and sediment flux from the Roof of the World
Authors: Lu X.X. , Zhang Shurong , Xu Jianchu 
Published: April 2010

AbstractPotential rises in global temperature are likely to have major impacts on high altitude environments, including glacier recession and permafrost degradation. In turn, these could have far‐reaching impacts on riverine sediment flux. Such impacts are emerging in the Himalayas and Tibet Plateau region, one of the world's largest and most environmentally‐sensitive cold regions. Closer monitoring is urgently required to track changing trends of sediment load from the interactions of glacial recession treat, rainfall changes and human interventions, and to study the implications of such changes for the large Asian river systems of the region. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical modelling of climate change impacts on Saint‐Lawrence River tributaries
Authors: Verhaar P. M. , Biron P. M. , Ferguson R. I. , Hoey T. B. 
Published: April 2010

AbstractThe impacts of climate‐induced changes in discharge and base level in three tributaries of the Saint‐Lawrence River, Québec, Canada, are modelled for the period 2010–2099 using a one‐dimensional morphodynamic model. Changes in channel stability and bed‐material delivery to the Saint‐Lawrence River over this period are simulated for all combinations of seven tributary hydrological regimes (present‐day and those predicted using three global climate models and two greenhouse gas emission scenarios) and three scenarios of how the base level provided by the Saint‐Lawrence River will alter (no change, gradual fall, step fall). Even with no change in base level the projected discharge scenarios lead to an increase in average bed material delivery for most combinations of river and global climate model, although the magnitude of simulated change depends on the choice of global climate model and the trend over time seems related to whether the river is currently aggrading, degrading or in equilibrium. The choice of greenhouse gas emission scenario makes much less difference than the choice of global climate model. As expected, a fall in base level leads to degradation in the rivers currently aggrading or in equilibrium, and amplifies the effects of climate change on sediment delivery to the Saint‐Lawrence River. These differences highlight the importance of investigating several rivers using several climate models in order to determine trends in climate change impacts. Copyright © 2010 John Wiley & Sons, Ltd.
Large scale landslides triggered by Quaternary tectonics in the Acambay graben, Mexico
Authors: Norini G. , Capra L. , Borselli L. , Zuniga F. R. , Solari L. , Sarocchi D. 
Published: April 2010

AbstractDetailed analysis was conducted on large‐scale gravitational‐tectonic deformations and landslides in the Acambay graben, an intra‐arc basin in the trans‐Mexican volcanic belt (TMVB). Field mapping and remote sensing revealed the slope instability of the northern graben boundary induced by the Acambay‐Tixmadejé fault. Two major landslides of 0·1 km3 and 0·05 km3 in volume were identified and their characteristics were analyzed according to the role of tectonics, mechanism of slope failure, and possible triggering factors. Quaternary faulting played a major role in increasing the local relief, and the activity of the Acambay‐Tixmadejé fault represents the main geomorphic factor conditioning the gravitational movements. Moreover, displacements along this fault generated sliding surfaces and reduced the strength of the rock mass. The two landslides are classified as large‐scale rotational slides involving volcanic rocks of late Miocene‐Pleistocene age. Since the Acambay graben is a seismogenic area with a known maximum horizontal ground acceleration of 0·5 g, a strong earthquake could be ascribed as the possible triggering mechanism of the landslides. Our work represents the first analysis of large gravitational slope movements in tectonically active regions in Mexico, a process that can be common in the intra‐arc basins of the TMVB, where active tectonic, seismicity, weak altered volcanic rocks, and heavy rains affect the slope stability. Copyright © 2010 John Wiley & Sons, Ltd.
Long-term trends in liver neoplasms in brown bullhead in the Buffalo River, New York, USA
Authors: Lauren Darrel J. , Hinton David , Law Mac , Sorensen Mary , Lyndall Jennifer , Magar Victor , Nielsen Mark 
Published: April 2010

Abstract
The Buffalo River area of concern (AOC) was assigned an impaired status for the fish tumors and other deformities beneficial use impairment category by the New York State Department of Environmental Protection in 1989. This was initially based on an inadequately documented brown bullhead (Ameiurus nebulosus) feeding study using river sediment extracts. The presence of liver tumors was subsequently supported by reports of a 19 to 27% prevalence in wild brown bullhead between 1983 and 1988 and a 4.8% prevalence in 1998. However, neither fish size (or age) nor sample locations were given, and histopathological definitions were inconsistent in these previous studies. Therefore, in 2008, we re-evaluated the prevalence of hepatocellular and chloangiocellular tumors (as well as other gross indicators of fish health) in brown bullhead averaging 25 cm in length collected from three reaches of the Buffalo River and recorded our collection sites by global positioning system. Among the 37 fish of appropriate size collected, only three exhibited liver tumors (8%). The tumors were evenly distributed within the three reaches, and only hepatocellular tumors were found. There were no differences in the prevalence of hepatic foci of alteration, body weight, length, or hepatosomatic index among the three reaches, but the conditions factor was significantly lower in fish from reach 2. Natural attenuation of water and sediment quality are the most likely causes for the decrease in liver tumors. The prevalence of liver tumors between 1998 and 2008 in the Buffalo River is similar to that found in recovery-stage AOCs and some Great Lakes reference areas. Environ. Toxicol. Chem. 2010; 29:1748–1754. © 2010 SETAC
Embryo malposition as a potential mechanism for mercury-induced hatching failure in bird eggs
Authors: Herring Garth , Ackerman Joshua T. , Eagles-Smith Collin A. 
Published: April 2010

Abstract
We examined the prevalence of embryo malpositions and deformities in relation to total mercury (THg) and selenium (Se) concentrations in American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), and Forster's tern (Sterna forsteri) eggs in San Francisco Bay (CA, USA) during 2005 to 2007. Overall, 11% of embryos were malpositioned in eggs ≥18 d of age (n = 282) and 2% of embryos were deformed in eggs ≥13 d of age (n = 470). Considering only those eggs that failed to hatch (n = 62), malpositions occurred in 24% of eggs ≥18 d of age and deformities occurred in 7% of eggs ≥13 d of age. The probability of an embryo being malpositioned increased with egg THg concentrations in Forster's terns, but not in avocets or stilts. The probability of embryo deformity was not related to egg THg concentrations in any species. Using a reduced dataset with both Se and THg concentrations measured in eggs (n = 87), we found no interaction between Se and THg on the probability of an embryo being malpositioned or deformed. Results of the present study indicate that embryo malpositions were prevalent in waterbird eggs that failed to hatch and the likelihood of an embryo being malpositioned increased with egg THg concentrations in Forster's terns. We hypothesize that malpositioning of avian embryos may be one reason for mercury-related hatching failure that occurs late in incubation, but further research is needed to elucidate this potential mechanism. Environ. Toxicol. Chem. 2010; 29:1788–1794. © 2010 SETAC