bluuebunny/crossref_metadata_2025 huggingface dataset:
Impartial graphical comparison of multivariate calibration methods and the harmony/parsimony tradeoff
Authors: Stout Forrest , Baines Maurita R. , Kalivas John H.
Published: April 2007

For multivariate calibration with the relationshipy = Xb, it is often necessary to determine the degrees of freedom for parsimony consideration and for the error measure root mean square error of calibration (RMSEC). This paper shows that degrees of freedom can be estimated by an effective rank (ER) measure to estimate the model fitting degrees of freedom and the more parsimonious model has the smallest ER. This paper also shows that when such a measure is used on the X‐axis, simultaneous graphing of model errors and other regression diagnostics is possible for ridge regression (RR), partial least squares (PLS) and principal component regression (PCR) and thus, a fair comparison between all potential models can be accomplished. The ER approach is general and applicable to other multivariate calibration methods. It is often noted that by selecting variables, more parsimonious models are obtained; typically by multiple linear regression (MLR). By using the ER, the more parsimonious model is graphically shown to not always be the MLR model. Additionally, a harmony measure is proposed that expresses the bias/variance tradeoff for a particular model. By plotting this new measure against the ER, the proper harmony/parsimony tradeoff can be graphically assessed for RR, PCR and PLS. Essentially, pluralistic criteria for fairly valuating and characterizing models are better than a dualistic or a single criterion approach which is the usual tactic. Results are presented using spectral, industrial and quantitative structure activity relationship (QSAR) data. Copyright © 2007 John Wiley & Sons, Ltd.
Improving feature extraction in fingerprint of medicinal herbs via wavelet transform and fractal technique
Authors: Du Jianwei , Tang Yuan Yan , Wang Jingrong , Jiang Zhihong
Published: April 2007

In this paper, hybrid features combing both high‐frequency and low‐frequency components of wavelet transform are applied to fingerprint of medicinal herbs. Through the fingerprints of medicinal herbs by wavelet transform and the fractal dimensions, 13 features are obtained, which are called fractal‐wavelet features. In this new approach, the information of each sample can be acquired to the maximum degree. These novel hybrid features have been applied to recognition of the different types of ginseng. Experiments have been conducted, and the result of recognition can match the real situation. Experiments indicate this method is better than the traditional ones. Copyright © 2007 John Wiley & Sons, Ltd.
Degradation of Adsorbed Sarin on Activated Carbons: A 31P‐MAS‐NMR Study
Authors: Kaplan Doron , Shmueli Liora , Nir Ido , Waysbort Daniel , Columbus Ishay
Published: April 2007

The fate of the OP nerve agent isopropyl methylphosphonofluoridate (sarin) on granular activated and metal‐impregnated activated carbons that are used in gas‐mask filters was investigated by means of 31P magic‐angle‐spinning (MAS) NMR spectroscopy. The results show that most of the adsorbed sarin on extensively dried carbons decomposes with a half‐life of 5–12 days. A MAS‐NMR signal of the degradation product isopropyl methylphosphonic acid (IMPA) appears in the spectra of sarin on non‐impregnated carbons. The IMPA signal is not visible in the spectra from metal‐impregnated carbons, probably due to strong binding of the acid molecule to paramagnetic Cr3+ and Cu2+ ions. Exposure of BPL and ASC carbons to air of 53% relative humidity shortens the degradation time by approximately an order of magnitude. Wetting shortens the half‐life of sarin on BPL carbon to approximately 2 hours.
Effective Removal of Microorganisms and Biostimulants of Wastewater by the Application of Various Electrolytes
Authors: Srivastava Jatin , Singh Nandita
Published: April 2007

A variety of electrolytes FeCl3, CaCl2, CuSO4, Al2(SO4)3, and LaCl3 was investigated for their efficiency in removing biostimulants (phosphorous and nitrogen) to improve the water quality. Results show that the removal of PO43– was achieved below the detection limit (BDL) by two electrolytes, CuSO4 and Al2(SO4)3, and up to 1.0 ± 0.0 mg/L by LaCl3 from a value of 15.0 mg/L, of the concentration of PO43– in amended water. The turbidity was found to be removed significantly by FeCl3, CuSO4, and Al2(SO4)3 by about 5.8 ± 2.6, 9.7 ± 1.0, and 5.4 ± 1.1 nephalometric turbidity unit (NTU), respectively. The removal of the members of Enterobacteriaceae viz., Escherichia coli, Enterobacter spp. Pseudomonas fluorescence, and Pseudomonas spp. was found almost in all the chemical precipitants but their removal was more significant in the water samples treated with CuSO4, Al2(SO4)3, and LaCl3. To achieve a complete removal and to sustain the after effects of precipitation, such as recurrence of algal growth, the combination of CuSO4 and Al2(SO4)3 was investigated. Reduction in the turbidity from 30.83 to <2 NTU, phosphate ion from a value of 1.28 mg/L to BDL and ammonia ion from a value of 44.71 to 36.48 mg/L of natural pond water were observed after the treatment with CuSO4 and Al2(SO4)3 in combination.
Cryptosporidium Oocysts in Drinking Water Supply of Chennai City, Southern India
Authors: Anbazhagi Muthukumar , Loganathan Dhanraj , Tamilselvan Subramani , Jayabalou Raj , Kamatchiammal Senthilkumar , Kumar Rakesh
Published: April 2007

Cryptosporidium is an enteric parasitic protozoan capable of causing chronic diarrhea. One of the most common modes of transmission is through faeces‐contaminated water. This study determines the distribution of Cryptosporidium oocysts for the first time in Chennai City's drinking water supply. 199 drinking water samples were collected from ten zones of the city. In the water samples Cryptosporidium, a common pathogenic protozoan of the gastrointestinal tract, has been analyzed physico chemically as well as microbiologically for heterotrophic organisms and total coliforms (TC). The studies revealed that three zones of the city were highly contaminated with coliforms and parasitic protozoa. A statistical analysis was done to find any correlation between heterotrophic organisms, total coliforms, and oocysts. Even though a positive correlation exists between oocysts and bacteriological parameters, a regression equation shows that heterotrophic plate count (HPC) and total coliforms were only 20% responsible for the presence of oocysts. The level of Cryptosporidium oocysts isolated from the water samples may present a public health hazard although no major outbreaks have so far been reported in Chennai City. Routine surveillance of water quality throughout the city is needed to curb the pollutants.
Further Study on the Kinetics of Bioremediation of Soils Contaminated with the Herbicide 2,4‐Dichlorophenoxy Acetic Acid
Authors: Sohrabi Morteza , Parvizi Azadeh
Published: April 2007

The bioremediation of soil contaminated with the herbicide 2,4‐dichlorophenoxy acetic acid has been studied applying the bacterium Ralstonia eutropha. The effects of temperature, pH, and moisture content of soils on the rate of degradation of this herbicide have been investigated. The Taguchi experimental design method was applied to determine the relative impacts of the pertinent system variables. According to this approach, four series of experiments were performed under various operating conditions. In all four series the herbicide was degraded efficiently, however, the highest rate was observed at a temperature of 35°C, pH 6, and at 80% moisture content of the soil. A kinetic model for the biodegradation of the herbicide was developed for this particular conditions based on the Monod type growth equation and autocatalytic behavior of the decomposition reaction. A close correlation has been observed between the experimental data and those predicted from the model. The degree of agreement was between 85–95%.
Modeling Aeration Efficiency of Stepped Cascades by Using ANFIS
Authors: Baylar Ahmet , Hanbay Davut , Ozpolat Emrah
Published: April 2007

The physical process of oxygen transfer or oxygen absorption from the atmosphere acts to replenish the used oxygen, a process termed re‐aeration or aeration. Aeration enhancement by macro‐roughness is well‐known in water treatment and one form is the aeration cascade. The macro‐roughness of the steps significantly reduces the flow velocities and leads to flow aeration along the stepped cascade. In this paper, the aeration efficiency in stepped cascade aerators was modeled by using the Adaptive Network Based Fuzzy Inference System (ANFIS). The obtained model was tested with experimental data. Test results showed that ANFIS can be used to estimate the aeration efficiency in stepped cascade aerators.
Prognostic relevance of the mTOR pathway in renal cell carcinoma
Authors: Pantuck Allan J. , Seligson David B. , Klatte Tobias , Yu Hong , Leppert John T. , Moore Laurence , O'Toole Timothy , Gibbons Jay , Belldegrun Arie S. , Figlin Robert A.
Published: April 2007

BACKGROUND.

The mammalian target of rapamycin (mTOR) pathway is up‐regulated in many human cancers, and agents targeting the mTOR pathway are in various stages of clinical development. The goal of the study was to evaluate the potential and limitations of targeting the mTOR pathway in renal cell carcinoma (RCC).

METHODS.

Immunohistochemical analysis using antibodies against pAkt, PTEN, p27, and pS6 was performed on a tissue microarray constructed from paraffin‐embedded specimens from 375 patients treated by nephrectomy for RCC. The expression was associated with pathological parameters and survival.

RESULTS.

The mTOR pathway was more significantly altered in clear‐cell RCC, high‐grade tumors, and tumors with poor prognostic features. PS6 and PTEN showed the strongest associations with pathological parameters. Survival tree analysis regarding expression of cytoplasmic pAkt, nuclear pAkt, PTEN, cytoplasmic p27, and pS6 identified staining percentages of 40%, 10%, 75%, 7%, and 70%, respectively, as ideal cutoff values for stratification, with corresponding P‐values of .03, .001, .02, .005, and <.0001, respectively. Interestingly, high nuclear pAkt expression was associated with a favorable prognosis, whereas high cytoplasmic pAkt expression was associated with a poor prognosis. In multivariate Cox regression analysis, ECOG PS, T classification, N classification, M classification, cytoplasmic Akt, nuclear pAkt, PTEN, and pS6 were independent prognostic factors of DSS.

CONCLUSIONS.

Components of the mTOR pathway are significantly associated with pathological features and survival. Not all RCC tumor types seem to be equally amenable to mTOR targeted therapy. PTEN, pAkt, p27, and pS6 may serve as surrogate parameters for patient selection and predicting prognosis. Patients with a highly activated mTOR pathway should benefit most from this therapy. External validation of our results is recommended. Cancer 2007. © 2007 American Cancer Society.
Instability of periodic BGK equilibria
Authors: Guo Yan , Strauss Walter A.
Published: April 2007

A collisionless plasma is described by the Vlasov‐Poisson equations. The BGK equilibria were proposed in 1957 as the simplest spatially‐dependent equilibria. Since that time the question of their instability has been an important open problem. We prove that certain periodic BGK equilibria are unstable. ©1995 John Wiley & Sons, Inc.
Evolutionary conservation and divergence of the segmentation process in arthropods
Authors: Damen Wim G. M.
Published: April 2007

A fundamental characteristic of the arthropod body plan is its organization in metameric units along the anterior–posterior axis. The segmental organization is laid down during early embryogenesis. Our view on arthropod segmentation is still strongly influenced by the huge amount of data available from the fruit fly Drosophila melanogaster (the Drosophila paradigm). However, the simultaneous formation of the segments in Drosophila is a derived mode of segmentation. Successive terminal addition of segments from a posteriorly localized presegmental zone is the ancestral mode of arthropod segmentation. This review focuses on the evolutionary conservation and divergence of the genetic mechanisms of segmentation within arthropods. The more downstream levels of the segmentation gene network (e.g., segment polarity genes) appear to be more conserved than the more upstream levels (gap genes, Notch/Delta signaling). Surprisingly, the basally branched arthropod groups also show similarities to mechanisms used in vertebrate somitogenesis. Furthermore, it has become clear that the activation of pair rule gene orthologs is a key step in the segmentation of all arthropods. Important findings of conserved and diverged aspects of segmentation from the last few years now allow us to draw an evolutionary scenario on how the mechanisms of segmentation could have evolved and led to the present mechanisms seen in various insect groups including dipterans like Drosophila. Developmental Dynamics 236:1379–1391, 2007. © 2007 Wiley‐Liss, Inc.
Developmental potential of Gcn5−/− embryonic stem cells in vivo and in vitro
Authors: Lin Wenchu , Srajer Geraldine , Evrard Yvonne A. , Phan Huy M. , Furuta Yas , Dent Sharon Y.R.
Published: April 2007

Gcn5 is a prototypical histone acetyltransferase (HAT) that serves as a coactivator for multiple DNA‐bound transcription factors. We previously determined that deletion of Gcn512 (hereafter referred to as Gcn5) causes embryonic lethality in mice. Gcn5 null embryos undergo gastrulation but exhibit high levels of apoptosis, leading to loss of mesodermal lineages. To further define the functions of Gcn5 during development, we created Gcn5−/− mouse embryonic stem (ES) cells. These cells survived in vitro and formed embryoid bodies (EBs) that expressed markers for ectodermal, mesodermal, and endodermal lineages. Gcn5−/− EBs were misshapen and smaller than wild‐type EBs by day 6, with an increased proportion of cells in G2/M. Expression of Oct 4 and Nodal was prematurely curtailed in Gcn5−/− EBs, indicating early loss of pluripotent ES cells. Gcn5−/− EBs differentiated efficiently into skeletal and cardiac muscle, which derive from mesoderm. High percentage Gcn5−/− chimeric embryos created by injection of Gcn5−/− ES cells into wild‐type blastocysts were delayed in development and died early. Interestingly, elevated levels of apoptosis were observed specifically in Gcn5 null cells within the chimeric embryos. Collectively, these data indicate that Gcn5 may be required to maintain pluripotent states and that loss of Gcn5 invokes a cell‐autonomous pathway of cell death in vivo. Developmental Dynamics 236:1547–1557, 2007. © 2007 Wiley‐Liss, Inc.
Shape‐Persistent Macrocycles: A Synthetic Strategy that Combines Easy and Site‐Specific Decorations with Improved Cyclization Efficiency
Authors: Sakamoto Junji , Schlüter A. Dieter
Published: April 2007

A flexible route to shape‐persistent macrocycles based on a collection of building blocks has been devised that allows the easy introduction of several different functional units at predetermined positions and the obtainment of cycles as analytically pure materials in high isolated yields of 22–45 % in the final cyclization process. Each step of the assembly process is based on high‐yielding and robust Suzuki‐ and Sonogashira‐type cross‐coupling reactions. In the latter, the best results were obtained in the absence of CuI iodide and with relatively large amounts of a palladium catalyst precursor. This holds true specifically for the cyclization reaction itself with these factors considered the key to the rather successful synthesis of the shape‐persistent macrocycles described herein. Each growth step is followed by a rather simple work up based on preparative gel‐permeation chromatography that allows the separation of 1 g and 300 mg of crude material at a time depending on whether an open column set up or a recycling GPC apparatus, respectively, is used. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Tertiary Amide Rotation in a Nanoscale Host
Authors: Salvio Riccardo , Moisan Lionel , Ajami Dariush , Rebek Julius
Published: April 2007

A 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

Measurements 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

Batch 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

The 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

Genomic 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

The 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

Recent 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

Objective

The 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 Methods

A 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.

Results

A 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.

Conclusions

The 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

Um 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

Noch 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.
Macromol. Rapid Commun. 8/2007
Authors: Yu Haifeng , Shishido Atsushi , Iyoda Tomokazu , Ikeda Tomiki
Published: April 2007

Cover: The cover picture shows the self‐assembled wormlike nanostructures in bulk films of an azobenzene‐containing diblock liquid‐crystalline copolymer. Eliminating the scattering of visible light by confining mesogenic segments in nanoscale microphase‐separated domains, the copolymer films showed highly transparent and stable under room light. Further details can be found in the article by H. Yu, A. Shishido, T. Iyoda, and T. Ikeda* on page 927.
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

The 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

Integrin 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

The 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

A 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

Objective

To explore the effect of maternal systemic lupus erythematosus (SLE) on first‐trimester screening markers for Down syndrome.

Methods

A 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).

Results

The 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.

Conclusions

Patients 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

This 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.
Brother versus brother: competitive stabilization of carbocationic centers by flanking cyclopropanes and π‐systems
Authors: Siebert Matthew R. , Tantillo Dean J.
Published: April 2007

B3LYP and MP2 quantum chemical calculations on cyclopropylcarbinyl cations fused to various cyclic and polycyclic architectures are described. ‘Competition’ for delocalization between the cyclopropane and other cyclopropanes and/or π‐systems incorporated into the (poly)cyclic framework to which it is fused was assessed, primarily through the use of characteristic geometric perturbations to the cyclopropane substructure. For example, a linear correlation between the orientation of the ‘empty p‐orbital’ at the carbocationic center, which is affected by the nature of the (poly)cyclic framework, and the magnitude of bond elongation in the cyclopropane was observed. Possible bis‐ and trishomoaromaticity of some systems was also evaluated using nucleus independent chemical shift (NICS) and magnetic susceptibility exaltation calculations. Copyright © 2007 John Wiley & Sons, Ltd.
Physical image vs structure relation: part 12 – structure of 2,2,5,5‐tetramethyl‐dihydro‐furan‐3‐one oxime and its protonated forms through isomerization and NMR spectra
Authors: Nazarski Ryszard B.
Published: April 2007

The study of an isomeric A/B mixture of the title oxime 1, by photolytic or thermal E,Z‐isomerization and NMR measurement including 1H{1H}‐NOE difference spectra, led to assignment of the E configuration to its predominating form A. The 1H/13C data were interpreted in terms of steric overcrowding of both forms, especially of the thermolabile photoproduct B. Four classical (empirical) NMR methods of elucidating the oxime geometry were critically tested on these results. Unexpected vapor‐phase photoconversion A→B in the window glass‐filtered solar UV and spectroscopic findings on their protonated states were discussed, as well. The kinetically controlled formation of the N‐protonated species (Z)‐5+ was proved experimentally. In addition, some 1H NMR assignments reported for structurally similar systems were rationalized (3 and 4) or revised (1 and 7–9) with the GIAO‐DFT(B3LYP) and/or GIAO‐HF calculational results. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and photochromism of 1,2‐dicyano[2.n]metacyclophan‐1‐enes
Authors: Takeshita Michinori , Inoue Masako , Hisasue Hideki , Maekawa Syun , Nakamura Takeshi
Published: April 2007

Syntheses and photochromic properties of 1,2‐dicyano[2.n]metacyclophan‐1‐enes are described. Dicyanometacyclophan‐1‐enes have been prepared by novel intramolecular coupling reaction of 1,n‐bis[(cyanomethyl)phenyl]alkanes in the presence of phase transfer catalyst. The photocyclization reaction of the prepared metacyclophan‐1‐enes took place upon irradiation with UV light and the pale yellow solution turned to violet due to the formation of the closed forms. The spectra and the color of the solutions returned to the initial states by the visible irradiation. The lifetimes of the closed forms were dependent on the chain length (n). As the chain length is shorter, the lifetime becomes longer. This is due to the steric energy of metacyclophan‐1‐ene. Hence, it becomes possible to control the thermal stability of the photoisomer by the change of chain length (n). The quantum yield for photocyclization reaction is the highest among 1,2‐dicyanodiarylethene family, since the conformation of the metacyclophan‐1‐ene is fixed to the photoactive form. Synthesis and photochromic properties of 1,2‐ dicyano[2.n]metacyclophan‐1‐enes bearing various kinds of substituents are also described. Copyright © 2007 John Wiley & Sons, Ltd.
ABA‐type amphiphilic triblock copolymers containing p‐ethoxy azobenzene via atom transfer radical polymerization: Synthesis, characterization, and properties
Authors: Tang Xinde , Gao Longcheng , Fan Xinghe , Zhou Qifeng
Published: April 2007

ABA‐type amphiphilic triblock copolymers composed of poly(ethylene glycol)s (PEGs) with different number‐average molecular weights as the hydrophilic blocks (B) and poly{6‐[4‐(4‐ethoxyphenylazo)phenoxy]hexyl methacrylate} (PA6C) as the hydrophobic blocks (A) were prepared via atom transfer radical polymerization. These copolymers were prepared from bromo‐terminated macroinitiators based on PEG6000, PEG2000, and PEG600, with CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as the catalytic system, at 85 °C in anisole. The block copolymers were characterized with 1H NMR spectroscopy and gel permeation chromatography. Differential scanning calorimetry measurements were performed to reveal the phase segregation. In contrast to those polymers with similar compositions and structures in previous reports, these amphiphilic copolymers exhibited unusual liquid‐crystalline properties over a wide temperature range, being stable even at room temperature. These copolymers showed photoresponsive isomerization under the irradiation of UV–vis light both in THF solutions and in solid films. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2225–2234, 2007
Kinetics and mechanism of the formation of poly[(1,1,3,3‐tetramethyldisiloxanyl)ethylene] and poly(methyldecylsiloxane) by hydrosilylation
Authors: AntiĆ V. V. , AntiĆ M. P. , Govedarica M. N. , DvorniĆ P. R.
Published: April 2007

The kinetics of the formation of poly(carbosiloxane), as well as of alkyl‐substituted poly(siloxane), by Karstedt's catalyst catalyzed hydrosilylation were investigated. Linear poly(carbosiloxane), poly[(1,1,3,3‐tetramethyldisiloxanyl)ethylene], (PTMDSE), was obtained by hydrosilylation of 1,3‐divinyltetramethyldisiloxane (DVTMDS) and 1,1,3,3‐tetramethyldisiloxane (TMDS), while alkyl‐substituted poly(siloxane), poly(methyldecylsiloxane), (PMDS), was synthesized by hydrosilylation of poly(methylhydrosiloxane) (PMHS) and 1‐decene. To investigate the kinetics of PTMDSE formation, two series of experiments were performed at reaction temperatures ranging from 25 to 56 °C and with catalyst concentrations ranging from 7.0 × 10−6 to 3.1 × 10−5 mol Pt/mol CHCH2. A series of experiments was performed at reaction temperatures ranging from 28 to 48 °C, with catalyst concentrations of 7.0 ×10−6 mol of Pt per mol of CHCH2, when kinetics of PMDS formation was investigated. All reactions were carried out in bulk, with equimolar amounts of the reacting SiH and CHCH2 groups. The course of the reactions was monitored by following the disappearance of the SiH bands using quantitative infrared spectroscopy. The results obtained showed typical first order kinetics for the PTMDSE formation, consistent with the proposed reaction mechanism. In the case of PMDS an induction period occurred at lower reaction temperatures, but disappeared at 44 °C and the rate of SiH conversion also started to follow the first‐order kinetics. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2246–2258, 2007
Molecular PCA3 diagnostics on prostatic fluid
Authors: van Gils Martijn P.M.Q. , Cornel Erik B. , Hessels Daphne , Peelen W. Pim , Witjes J. Alfred , Mulders Peter F.A. , Rittenhouse Harry G. , Schalken Jack A.
Published: April 2007

BACKGROUND

The PCA3 test on urine can improve specificity in prostate cancer (PCa) diagnosis and could prevent unnecessary prostate biopsies. In this study, we evaluated the PCA3 test on prostatic fluid and compared this with the PCA3 test on urine in a clinical research setting.

METHODS

Prostatic fluid and urine samples from 67 men were collected following digital rectal examination (DRE). The sediments were analyzed using the quantitative APTIMA® PCA3 test. The results were compared with prostate biopsy results.

RESULTS

Using a PCA3 score of 66 as a cut‐off value, the test on prostatic fluid had 65% sensitivity for the detection of PCa, 82% specificity and a negative predictive value of 82%. At a cut‐off value of 43, the test on urine had 61% sensitivity, 80% specificity and a negative predictive value of 80%.

CONCLUSIONS

The PCA3 test can be performed on both urine and prostatic fluid in the diagnosis of PCa with comparable results. Prostate 67: 881–887, 2007. © 2007 Wiley‐Liss, Inc.