bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tertiary Amide Rotation in a Nanoscale Host
Authors: Salvio Riccardo , Moisan Lionel , Ajami Dariush , Rebek Julius 
Published: April 2007

AbstractA self‐assembled cylindrical capsule provides a nanoscale environment that affects the rotational barriers of tertiary amides. Measurements of the activation energies for the rotations and behaviors of the amides inside the capsule were determined by using 1H NMR spectroscopic methods in deuterated mesitylene solution. For amides 3–8, rotation rates can decrease or increase in the capsule by up to an order of magnitude from those of the free amides in solution depending on the structure of the amides. The acceleration/deceleration of the rotation results from selective destabilization/stabilization of the ground state or the transition state. In the case of compound 10, the rotation generates two isomers that are equimolar in solution but inside the capsule only one of them is observed. Accordingly, the rotation rate is slowed by several orders of magnitude inside the capsule. In the case of amide 8, a competition experiment indicates that the acceleration of the rotation inside the capsule is due to destabilization of the ground state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The influence of riparian vegetation on near‐bank turbulence: a flume experiment
Authors: McBride Maeve , Hession W. Cully , Rizzo Donna M. , Thompson Douglas M. 
Published: April 2007

AbstractMeasurements from a fixed‐bed, Froude‐scaled hydraulic model of a stream in northeastern Vermont demonstrate the importance of forested riparian vegetation effects on near‐bank turbulence during overbank flows. Sections of the prototype stream, a tributary to Sleepers River, have increased in channel width within the last 40 years in response to passive reforestation of its riparian zone. Previous research found that reaches of small streams with forested riparian zones are commonly wider than adjacent reaches with non‐forested, or grassy, vegetation; however, driving mechanisms for this morphologic difference are not fully explained. Flume experiments were performed with a 1:5 scale, simplified model of half a channel and its floodplain, mimicking the typical non‐forested channel size. Two types of riparian vegetation were placed on the constructed floodplain: non‐forested, with synthetic grass carpeting; and forested, where rigid, randomly distributed, wooden dowels were added. Three‐dimensional velocities were measured with an acoustic Doppler velocimeter at 41 locations within the channel and floodplain at near‐bed and 0·6‐depth elevations. Observations of velocity components and calculations of turbulent kinetic energy (TKE), Reynolds shear stress and boundary shear stress showed significant differences between forested and non‐forested runs. Generally, forested runs exhibited a narrow band of high turbulence between the floodplain and main channel, where TKE was roughly two times greater than TKE in non‐forested runs. Compared to non‐forested runs, the hydraulic characteristics of forested runs appear to create an environment with higher erosion potential. Given that sediment entrainment and transport can be amplified in flows with high turbulence intensity and given that mature forested stream reaches are wider than comparable non‐forested reaches, our results demonstrated a possible driving mechanism for channel widening during overbank flow events in stream reaches with recently reforested riparian zones. Copyright © 2007 John Wiley & Sons, Ltd.
Instabilities during batch sedimentation in geometries containing obstacles: A numerical and experimental study
Authors: Rao Rekha R. , Mondy Lisa A. , Altobelli Stephen A. 
Published: April 2007

AbstractBatch sedimentation of non‐colloidal particle suspensions is studied with nuclear magnetic resonance flow visualization and continuum‐level numerical modelling of particle migration. The experimental method gives particle volume fraction as a function of time and position, which then provides validation data for the numerical model. A finite element method is used to discretize the equations of motion, including an evolution equation for the particle volume fraction and a generalized Newtonian viscosity dependent on local particle concentration. The diffusive‐flux equation is based on the Phillips model (Phys. Fluids A 1992; 4:30–40) and includes sedimentation terms described by Zhang and Acrivos (Int. J. Multiphase Flow 1994; 20:579–591). The model and experiments are utilized in three distinct geometries with particles that are heavier and lighter than the suspending fluid, depending on the experiment: (1) sedimentation in a cylinder with a contraction; (2) particle flotation in a horizontal cylinder with a horizontal rod; and (3) flotation around a rectangular inclusion. Secondary flows appear in both the experiments and the simulations when a region of higher density fluid is above a lower density fluid. The secondary flows result in particle inhomogeneities, Rayleigh–Taylor‐like instabilities, and remixing, though the effect in the simulations is more pronounced than in the experiments. Published in 2007 by John Wiley & Sons, Ltd.
A Direct Ammonia Fuel Cell Using Barium Cerate Proton Conducting Electrolyte Doped With Gadolinium and Praseodymium
Authors: Maffei N. , Pelletier L. , Charland J. P. , McFarlan A. 
Published: April 2007

AbstractThe performance characteristics of fuel cells based on proton conducting BaCeO3 solid electrolyte doubly doped with gadolinium and praseodymium are reported. The amount of praseodymium doping is systematically varied in order to optimize the fuel cell performance. Fuel cells incorporating the optimum amount of praseodymium exhibit power density levels enhanced by a factor of three, compared to those incorporating undoped BaCeO3. The performance of the fuel cell is essentially the same irrespective of the fuel used. However, the performance of the fuel cell is slightly better in hydrogen than in ammonia. Nevertheless, fuel cells operated in ammonia show a greater decrease in peak power density with decreasing temperature than those operated in hydrogen. This behaviour suggests that alternative anode materials need to be utilized at lower operating temperatures.
Chromosome 8 BAC array comparative genomic hybridization and expression analysis identify amplification and overexpression of TRMT12 in breast cancer
Authors: Rodriguez Virginia , Chen Yidong , Elkahloun Abdel , Dutra Amalia , Pak Evgenia , Chandrasekharappa Settara 
Published: April 2007

AbstractGenomic changes in chromosome 8 are commonly observed in breast cancer cell lines and tumors. To fine map such genomic changes by comparative genomic hybridization (CGH), a high resolution (100 kb) chromosome 8 array that can detect single copy changes was developed using Phi29 DNA polymerase amplified BAC (bacterial artificial chromosome) DNA. The BAC array CGH resolved the two known amplified regions (8q21 and 8q24) of a breast cancer cell line (SKBR3) into nine separate regions including six amplicons and three deleted regions, all of which were verified by Fluorescence in situ hybridization. The extent of the gain/loss for each region was validated by qPCR. CGH was performed with a total of 8 breast cancer cell lines, and common regions of genomic amplification/deletion were identified by segmentation analysis. A 1.2‐Mb region (125.3–126.5 Mb) and a 1.0‐Mb region (128.1–129.1 Mb) in 8q24 were amplified in 7/8 cell lines. A global expression analysis was performed to evaluate expression changes associated with genomic amplification/deletion: a novel gene, TRMT12 (at 125.5 Mb), amplified in 7/8 cell lines, showed highest expression in these cell lines. Further analysis by RT‐qPCR using RNA from 30 breast tumors showed that TRMT12 was overexpressed >2 fold in 87% (26/30) of the tumors. TRMT12 is a homologue of a yeast gene encoding a tRNA methyltransferase involved in the posttranscriptional modification of tRNAPhe, and exploring the biological consequence of its altered expression, may reveal novel pathways in tumorigenesis. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat. Published 2007 Wiley‐Liss, Inc.
Alcohol consumption and risk of bladder cancer in Los Angeles County
Authors: Jiang Xuejuan , Castelao J. Esteban , Groshen Susan , Cortessis Victoria K. , Ross Ronald K. , Conti David V. , Gago‐Dominguez Manuela 
Published: April 2007

AbstractThe role of alcoholic beverages in bladder carcinogenesis is still unclear, with conflicting evidence from different studies. We investigated the relationship between alcohol consumption and bladder cancer, and the potential interaction between alcohol consumption and other exposures. In a population‐based case–control study conducted in Los Angeles County, 1,586 pairs of cases and their matched neighborhood controls were interviewed. Data were analyzed to determine whether bladder cancer risk differs by alcohol consumption, and whether different alcoholic beverages have different effects. The risk of bladder cancer decreased with increasing frequency (p for trend = 0.003) and duration of alcohol consumption (p for trend = 0.017). Subjects who drank more than 4 drinks per day had a 32% lower (odds ratio, 0.68; 95% confidence interval, 0.52–0.90) risk of bladder cancer than those who never drank any alcoholic beverage. Beer (p for trend = 0.002) and wine (p for trend = 0.054) consumption were associated with reduced risk of bladder cancer, while hard liquor was not. The reduction in risk was mostly seen among shorter‐term smokers who urinated frequently. Alcohol consumption was strongly associated with a reduced risk of bladder cancer. The effect was modified by the type of alcoholic beverage, cigarette smoking and frequency of urination. © 2007 Wiley‐Liss, Inc.
Social capital, barriers to production and capital shares: implications for the importance of parameter heterogeneity from a nonstationary panel approach
Authors: Pedroni Peter 
Published: April 2007

AbstractRecent advances in the growth literature have proposed that difficult‐to‐quantify concepts such as social capital may play an important role in explaining the degree of persistent income disparity that is observed among countries. Other recently explored possibilities include institutional mechanisms which generate barriers to aggregate production. An important limitation for empirical work in this area stems from the fact that it is difficult to distinguish sources of heterogeneity when direct observations are not available. In this study, we show how developments in the analysis of nonstationary panels can aid in this endeavor. In contrast to traditional dynamic panel data analysis, this approach focuses explicitly on low‐frequency behavior. Under relatively mild assumptions, the approach can be used to infer properties of aggregate production which are robust to the presence of large classes of unobserved features. In this framework we are able to estimate and test the distribution of production function parameters that would be required in order to generate conditional forecast convergence of per capita incomes even when some of the key factors required to explain growth are unobserved. The results indicate that in order to fully explain the observed persistence in the disparity of per capita incomes, the manner in which unobserved mechanisms influence production must go beyond merely accounting for differences in the trending behavior of aggregate productivity. Specifically, if such mechanisms are to be successful empirically, they must also be able to account for cross‐country heterogeneity in steady‐state capital shares. This adds to a growing literature that provides support for models with multiple production regimes. Copyright © 2007 John Wiley & Sons, Ltd.
Dichlorodiphenyldichloroethylene concentrations in umbilical cord of newborns and determinant maternal factors
Authors: Barraza‐Vázquez Antonio , Borja‐Aburto Víctor Hugo , Bassol‐Mayagoitia Susana , Monrroy Antonio , Recio‐Vega Rogelio 
Published: April 2007

AbstractObjectiveThe aim was to identify exposure levels to dichlorodiphenyltrichloroethane (DDT) and to assess maternal factors as determinants of the serum dichlorodiphenyldichloroethylene (DDE) concentration in umbilical cord in newborns from the Mexican Pacific coastal area of Oaxaca State.Materials and MethodsA cross‐sectional study was conducted of 86 paired mothers and newborns from the Oaxaca community of Pochutla. Blood and umbilical cord blood samples were collected to determine DDT and DDE by GC. Information concerning possible determinant factors with regard to pesticide concentration was obtained by means of a questionnaire.ResultsA positive correlation between maternal and umbilical cord serum DDE concentration was observed (geometric mean of 7.69 µg g−1 and 7.29, respectively). Multiple analyses showed that significant maternal factors related to umbilical cord serum DDE concentrations were: always having lived in the same community; low to high socioeconomic strata; accumulated breast‐feeding time.ConclusionsThe determinant factors observed in this study must be considered in future studies for the quantification of organochlorine concentration. In addition, these factors must be taken into account when preventive actions to minimize in utero exposure to these pesticides are carried out. Copyright © 2007 John Wiley & Sons, Ltd.
Laser beflügelt die Solartechnik – Lasereinsatz in der Photovoltaik
Authors: Wallenta Petra , Kluge Michael 
Published: April 2007

AbstractUm Solartechnik noch stärker in den Markt zu bringen muss die Produktion günstiger werden. Unterschiedliche Ansätze und Vorgehensweisen kommen hierbei zum Tragen. Eine Schlüsseltechnologie für mehr Effizienz ist dabei sicherlich die Lasertechnik. Sie ermöglicht den Einsatz neuer Verfahren und den sparsameren Einsatz von Ressourcen.
Optische Gitter: Die Abbildung der Realität – 75 Jahre berührungslose dynamische Meßtechnik auf der Basis optischer Gitter
Authors: Haus Jörg , Lauinger Norbert 
Published: April 2007

AbstractNoch vor dem Beginn der modernen Optik, sogar vor Erfindung der Halbleiterelektronik erblickte ein optoelektronisches Sensorprinzip das Licht der Welt, das die Detektion von Bewegungen durch die Abbildung auf ein Gitter ermöglichte. Aber erst in den 1960er Jahren führte ein tieferes Verständnis der Signaltheorie hinter dem optischen Aufbau zu einer weiten Verbreitung dieser Technologie für die berührungslose, schlupffreie Messung dynamischer Vorgänge. Der vorliegende Artikel beschreibt Vergangenheit, Gegenwart und Zukunft eines Meßprinzips, auf das sich zwei Schwesterfirmen in der Tradition der ehemaligen Ernst Leitz Wetzlar GmbH spezialisiert haben.
Nicotine alters bovine oocyte meiosis and affects subsequent embryonic development
Authors: Liu Ying , Li Guang‐Peng , White Kenneth L. , Rickords Lee F. , Sessions Benjamin R. , Aston Kenneth I. , Bunch Thomas D. 
Published: April 2007

AbstractThe effects of nicotine on nuclear maturation and meiotic spindle dynamics of bovine oocytes and subsequent embryonic development were investigated. Maturation rates (85%–94%) derived from nicotine treatments at 0.01 to 1.0 mM were similar to the control (86%), but significantly decreased at 2.0 to 6.0 mM. Haploid complements of metaphase II oocytes in 0.01 to 1.0 mM nicotine (approximately 90%) were similar to the control, while lower (ranged from 63% to 76%, P < 0.05 or P < 0.01) haploid oocytes were observed in the 2.0 to 6.0 mM nicotine groups. The majority of the PB1‐free oocytes derived from 3.0 to 6.0 mM nicotine treatments were diploidy (2n = 60). Spindle microtubules changed from characteristically being asymmetrical in the controls to being equally distributed into two separate chromosome groups in the nicotine treatments. Nicotine disorganized the microfilament organization and inhibited the movement of anaphase or telophase chromosomes to the cortical area. The inhibited two chromosome groups became two spindles that either moved close in proximity or merged entirely together resulting in diploidy within the affected oocyte. Nicotine treatment significantly reduced the rate of cleavage and blastocyst development after parthenogenetic activation. Diploidy and cell number were drastically reduced in the resultant blastocysts. In conclusion, nicotine can alter the normal process of bovine oocyte meiosis and affects subsequent embryonic development. Mol. Reprod. Dev. 74: 1473–1482, 2007. © 2007 Wiley‐Liss, Inc.
Expression of αV and β3 integrin subunits during implantation in pig
Authors: Lin Haichao , Wang Xin , Liu Guifen , Fu Jinlian , Wang Aiguo 
Published: April 2007

AbstractIntegrin are adhesion molecules involved in uterine–conceptus interactions during the perimplantation period. In this study, the expression of αV and β3 integrin subunits in endometrium during implantation in pigs was investigated. The immunohistochemical location was performed on paraformaldehyde‐fixed, paraffin‐embedded tissue sections, and the mRNA expression of αV was detected in endometrium. In addition, serum levels of estradiol, progesterone, follicle‐stimulating hormone, and luteinizing hormone were measured on Days 0, 12, 18, and 25 of pregnancy. The results indicate that endometrium expressed integrin αV and β3 in all stages examined. The most intensive staining for integrin αV and β3 was observed in endometrial stroma in porcine pregnancy on Day 18. The mRNA of αV integrin strongly expressed on Day 18, and moderately expressed on Days 12 and 25. The correlation between serum hormone level and the mRNA expression of αV integrin was not significant. The expression patterns of integrin αV and β3 during implantation provide insights into the important physiological function of αVβ3 integrin in pig, and the strong expression of integrin αV and β3 in mid‐implantation may indicate its crucial role in successful implantation and embryo survival. Mol. Reprod. Dev. 74: 1379–1385, 2007. © 2007 Wiley‐Liss, Inc.
Factors affecting the in vitro action of cumulus cells on the maturing mouse oocytes
Authors: Ge Li , Han Dong , Lan Guo‐Cheng , Zhou Ping , Liu Yong , Zhang Xia , Sui Hong‐Shu , Tan Jing‐He 
Published: April 2007

AbstractThe removal of cumulus cells (CCs) from oocytes at the germinal vesicle (GV) stage still represents a major limitation in such embryo techniques as GV transfer, somatic cell haploidization, and oocyte cryopreservation. However, no efficient in vitro maturation (IVM) system for CC‐denuded oocytes (DOs) has been established in mammalian species. Although follicular cells are considered to play an important role in oocyte maturation, the specific role and mechanisms of action of different cell types are poorly understood. Reports on whether junctional association between CCs and the oocyte is essential for the beneficial effect of CC co‐culture on oocyte maturation are in conflict. Our objective was to try to address these issues using the mouse oocyte model. The results indicated that while co‐culture with the CC monolayer could only partially restore the developmental potential of DOs without corona cells, it restored the competence of corona‐enclosed DOs completely. Culture in medium conditioned with CC monolayer also promoted maturation of DOs. However, co‐culture with the monolayer of mural granulosa cells had no effect. The efficiency of CC co‐culture was affected by various factors such as density and age of the CCs, the presence of gonadotropin in the maturation medium and the duration for in vivo (IVO) gonadotropin priming. It is concluded that mouse CCs produce a diffusible factor(s) that support DO maturation in a CC‐oocyte junctional communication dependent manner. The data will contribute to our understanding the mechanisms by which CCs promote oocyte maturation and to the establishment of an efficient DO IVM system. Mol. Reprod. Dev. 75: 136–142, 2008. © 2007 Wiley‐Liss, Inc.
Analysis of polyphenolic compounds and radical scavenging activity of four American Actaea species
Authors: Nuntanakorn Paiboon , Jiang Bei , Yang Hui , Cervantes‐Cervantes Miguel , Kronenberg Fredi , Kennelly Edward J. 
Published: April 2007

AbstractA reversed‐phase high‐performance liquid chromatography (RP‐HPLC) method with diode array detection has been developed for analysis of the major polyphenols in the roots and rhizomes of black cohosh (Actaea racemosa), an important botanical dietary supplement for women's health, and three closely related American Actaea species, A. rubra, A. pachypoda and A. podocarpa. The method was validated with respect to sensitivity, linearity, precision, accuracy and recovery. The total content of eight major polyphenols in the dried root and rhizome of the four species was determined to be from 0.36 to 2.92% (w/w). The antioxidant activities of Actaea extracts and polyphenolic compounds isolated from A. racemosa were evaluated on 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radicals scavenging assay. The radical scavenging activity of the Actaea extracts correlates to their polyphenolic composition. This validated HPLC method can be used to distinguish A. racemosa from the other major American Actaea species based on this study. Copyright © 2007 John Wiley & Sons, Ltd.
Influence of maternal systemic lupus erythematosus on first‐trimester combined screening for chromosomal abnormalities
Authors: Heinig J. , Steinhard J. , Schmitz R. , Nofer J.‐R. , Kiesel L. , Klockenbusch W. 
Published: April 2007

AbstractObjectiveTo explore the effect of maternal systemic lupus erythematosus (SLE) on first‐trimester screening markers for Down syndrome.MethodsA retrospective study was conducted on 1150 normal singleton fetuses that underwent first‐trimester combined screening for Down syndrome. Fetal delta nuchal translucency (NT), maternal serum PAPP‐A and free β‐hCG were compared between pregnancies with SLE (n = 10) and without preexisting maternal disease (n = 1140).ResultsThe medians ± SD for delta NT, log10 MoM of PAPP‐A and free β‐hCG ± SD in pregnancies with SLE and without maternal disease were − 0.18 ± 0.29 versus − 0.18 ± 0.33, 0.005 ± 0.32 versus 0.02 ± 0.26, and 0.22 ± 0.19 versus − 0.014 ± 0.28, with a p value of 0.7, 0.98 and 0.03, respectively.ConclusionsPatients with preexisting SLE have increased maternal serum‐free β‐hCG levels in the first‐trimester. But, because of the multimodal procedure of risk calculation there is no significant difference in the screen‐positive rate after the combined first‐trimester screening for trisomy 21. Copyright © 2007 John Wiley & Sons, Ltd.
Prenatal diagnosis of complete trisomy 19q
Authors: Babić Ivana , Brajenović‐Milić Bojana , Petrović Oleg , Mustać Elvira , Kapović Miljenko 
Published: April 2007

AbstractThis communication presents the first case of complete trisomy 19q, prenatally detected by ultrasound investigation.Real‐time high‐resolution ultrasound examination was performed at 19 weeks of gestation. After termination of the pregnancy, autopsy investigation was done. GTG‐banding, fluorescence in situ hybridization m‐(FISH) analysis, and FISH analysis with a 19q subtelomeric specific probe were used for identification of the fetal karyotype. Sonographic examination revealed an enlarged cisterna magna, cerebellar hypoplasia and aplasia of the inferior part of the vermis, combined and bilateral kidney malformations, significant nuchal fold, absence of fetal nasal bones, and intracardial calcifications. Autopsy confirmed ultrasound findings, but also revealed situs viscerum inversus of the lungs. Fetal karyotype was defined as: 46,XY,der(21)t(19;21)(q11;p13)mat. Our ultrasound and autopsy findings will certainly contribute to better knowledge of phenotype characterization of this rare chromosomal disorder. Copyright © 2007 John Wiley & Sons, Ltd.