bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of decreasing soil water content on seminal lateral roots of young maize plants
Authors: Kuchenbuch Rolf O. , Ingram Keith T. , Buczko Uwe
Published: December 2006

Soil micropores that contain water at or below field capacity cannot be invaded by seminal or first‐order lateral roots of maize plants because their root diameters are larger than 10 μm. Hence, at soil‐water levels below field capacity plant roots must establish a new pore system by displacement of soil particles in order to access soil water. We investigated how decreasing soil water content (SWC) influences growth and morphology of the root system of young maize plants. Plants were grown in rhizotrons 40 cm wide, 50 cm high, and approximately 0.7 cm thick. Five SWC treatments were established by addition of increasing amounts of water to soil and thorough mixing before filling the rhizotrons. No water was added to treatments 1–4 throughout the experiment. Treatment 5 was watered frequently throughout the experiment to serve as a control. Seminal‐root length and SWC in soil layers 0–10, 10–20, 20–30, 30–40, and 40–50 cm were measured at intervals of 2–3 d on scanner images by image analysis. At 15 d after planting, for treatments 1–4 shoot dry weight and total root length were directly related to the amount of water added to the soil, and for treatments 4 and 5, total root length and shoot dry weights were similar. Length of seminal roots visible at the transparent surface of the rhizotron for all treatments was highest in the uppermost soil layer and decreased with distance from the soil surface. For all layers, seminal‐root elongation rate was at maximum above a SWC of 0.17 cm3 cm–3, corresponding to a matric potential of –30 kPa. With decreasing SWC, elongation rate decreased, and 20% of maximum seminal root elongation rate was observed below SWC of 0.05 cm3 cm–3. After destructive harvest for treatment 1–4, number of (root‐) tips per unit length of seminal root was found uninfluenced over the range of initial SWC from 0.10 to 0.26 cm3 cm–3. However, initial SWC close to the permanent wilting point strongly increased number of tips. Average root length of first‐order lateral (FOL) roots increased as initial SWC increased, and the highest length was found for the frequently watered treatment 5. The results of the study suggest that the ability to produce new FOL roots across a wide range of SWC may give maize an adaptive advantage, because FOL root growth can rapidly adapt to changing soil moisture conditions.
Effects of cadmium on growth parameters of endophyte‐infected endophyte‐free ryegrass
Authors: Ren Anzhi , Gao Yubao , Zhang Liang , Xie Fengxing
Published: December 2006

A greenhouse hydroponic experiment was conducted to study the effects of cadmium (Cd) on growth parameters of endophyte‐infected (EI) and endophyte‐free (EF) perennial ryegrass. The results showed that Cd stress (0.18 mM Cd) affected all measured plant parameters, regardless of whether they were endophyte‐infected or endophyte‐free. Endophyte infection enhanced tillering ability and reduced leaf elongation under conditions of Cd stress. Endophyte infection tended to reduce leaf and leaf‐sheath biomass of control plants (0 Cd), but tended to alleviate the detrimental effects of Cd regarding shoot biomass. As far as net–photosynthetic rate and maximal photochemical efficiency of photosystem II (Fv/Fm ratio) were concerned, no difference was observed between EI and EF leaves. Like other grasses, perennial ryegrass can accumulate Cd, and Cd concentrations in different organs were in the following order: root > sheath > leaf. Endophyte‐infected ryegrass accumulated more Cd than EF ryegrass, especially in the shoots.
Genotypic variation for phosphorus uptake dinitrogen fixation in cowpea on low‐phosphorus soils of southern Cameroon
Authors: Jemo Martin , Abaidoo Robert C. , Nolte Christian , Horst Walter J.
Published: December 2006

In cowpea, efficient N2‐fixing genotypes are being selected to promote sustainable cropping systems in southern Cameroon (SC). However, N2 fixation and growth of these genotypes are largely hampered by low levels of soil plant‐available P. To evaluate the genotypic variation in N2 fixation and P uptake among cowpea (Vigna unguiculata L.) genotypes, field experiments were conducted over two years on two acid soils low in available P. The experiments were laid out in a split‐block design with four replications on typic (TK) and rhodic (RK) Kandiudult soils with seven cowpea genotypes. Phosphorus (P) fertilizers were applied on the main plots with 0 kg P, 30 kg P ha–1 as triple superphosphate (TSP) and 90 kg P ha–1 as Togo phosphate rock (PR). Nodule dry matter (DM), shoot DM, grain yield, and P uptake of cowpea significantly varied with site, P application, and genotype (p < 0.05). The N2 fixation of the cowpea genotypes ranged from 29 to 51 kg N ha–1 on both TK and RK soils and was significantly increased with P application. Significant genotypic variations in N2 fixation were observed with superior ability of the genotypes IT89KD‐391 and IT90K‐59 to fix N2. The harvest index (HI) did not significantly differ between soils and P application levels (p > 0.05). Four genotypes were selected to investigate root mechanisms responsible for efficient P acquisition in pot experiments. The results suggest that a better root infection by arbuscular mycorrhizal fungi (AMF) in genotype IT90K‐59 and root morphological and physiological characteristics in IT89KD‐391 were the most important factors for increasing P uptake.
Influence of N form on growth photosynthesis of Phaseolus vulgaris L. plants
Authors: Brück Holger , Guo Shiwei
Published: December 2006

Many plant species are characterized by pronounced sensitivity to sole ammonium supply and exhibit growth depression and particularly reduced leaf growth rates. Stress symptoms under sole ammonium supply may be related to perturbation of photosynthetic processes, e.g., low rates of net CO2 assimilation, low quantum yield, reduced stomatal conductance, and carboxylation capacity. The results of three experiments with French bean plants supplied with an N concentration of 5 mM illustrate significantly lower dry mass and specific leaf area, reduced leaf expansion, and higher chlorophyll and N content of ammonium‐ compared to nitrate‐supplied plants. Light‐saturated rates of CO2 assimilation (Amax) per unit leaf area were higher under ammonium compared to nitrate supply while no significant effects of N form on quantum yield and Amax per unit leaf weight and chlorophyll were found. Maximal carboxylation (Vcmax) and electron‐transport (JMax) rates were significantly higher under ammonium supply only in one of three experiments. Vcmax was linearly related to total leaf N, the slope of the regression was similar with both N forms, the x‐axis intercept was significantly higher for ammonium‐ compared to nitrate‐supplied plants. The ratio Vcmax : JMax was not affected by N form. It is concluded that ammonium supply had no negative effects on the operation of photosynthetic protein‐enzyme complexes.
Montezuma pine nutrient status as affected by alder densities nitrogen fertilization
Authors: López‐López Miguel A. , Aguirre‐Bravo Celedonio , Reich Robin
Published: December 2006

Literature reports both positive and negative effects of N‐fixing alders on conifer growth in alder‐conifer stands. Such divergent effects probably result from poorly understood species interactions. The aim of this work was to examine how varying alder‐to‐pine ratios (APRs) and N fertilization affect pine nutrient status. A pseudo‐experiment was installed in each of two areas of regeneration (AR) with different amounts of radiation reaching alder. The experimental approach consisted of a series of pseudoreplicated plots with five APRs within each AR. Half of each plot received 200 kg N ha–1. Data were interpreted by vector analysis. Alders in the AR 1987 induced needle‐biomass reductions, K deficiency, and P accumulation in pine needles. However, nutrient availability increased with the proportion of alders in the AR 1989, where alders received high sunlight due to a less dense pine stand. Nitrogen fertilization increased needle biomass and N in three out of five alder proportions where alders were sunlight‐limited. In the other stand, with the exception of the no‐alder and A4 plots, positive effects of N fertilization increased with decreasing alder density. We conclude that sunlight‐limited alders may not positively affect associated‐species growth even in N‐limited sites.
Vergleichende Untersuchungen zur Pflanzenverfügbarkeit von Phosphat aus verschiedenen P‐Recycling‐Produkten im Keimpflanzenversuch
Authors: Römer Wilhelm
Published: December 2006

Die Weltreserven an Rohphosphaten hoher Qualität und moderater Abbaukosten reichen noch für ca. 90 Jahre. Daraus leitet sich die Notwendigkeit des Phosphat (P)‐Recyclings aus P‐haltigen Abfällen ab. In Deutschland fallen jährlich 2,4 × 106 t Trockenmasse Klärschlamm und über 600.000 t Abfälle tierischen Ursprungs an. Mit dem daraus recycelten P könnte der größte Teil der bisherigen P‐Mineraldünger ersetzt werden. Verlässliche Daten über die Pflanzenverfügbarkeit des P liegen für viele Produkte des P‐Recyclings jedoch noch nicht vor. In einem 21‐tägigen Keimpflanzenversuch (Applikation von 20 mg P (300 g Quarzsand)–1 in 10 cm × 10 cm × 6 cm großen Plastikgefäßen; Aussaat von 100 Roggenkörnern; Einstellung auf 65% der max. Wasserkapazität) wurden daher 26 P‐Verbindungen überprüft (u. a. verschiedene Calcium‐, Magnesium, Eisen‐, Aluminium‐, Ammonium‐ bzw. Magnesium‐Ammonium‐Phosphate, Thomasphosphate). Als Kontrolle wurde eine Variante ohne P‐Gabe eingesetzt. Die Netto‐P‐Aufnahme (P‐Menge in Sprossen und Wurzeln minus P‐Menge in den Kontrollpflanzen) ergab Auskunft über die P‐Verfügbarkeit für die Pflanzen. Die P‐Aufnahme aus den Ca‐Phosphaten sank erwartungsgemäß vom primären Ca‐Phosphat (als Referenz gleich 100 % gesetzt) bis zum Ca‐Apatit auf 10 %. Aus primärem, sekundärem und tertiärem Mg‐Phosphat wurden P‐Mengen ähnlich denen aus dem primären Ca‐Phosphat aufgenommen. Das gleiche galt für die P‐Aufnahme aus Ammonium‐Phosphat und Magnesium‐Ammonium‐Phosphat (Struvit). Thomasphosphate und Sinterphosphate zeigten nur etwa 42 bis 65 % der P‐Verfügbarkeit von primärem Ca‐Phosphat. Insbesondere Fe‐Phosphat versagte völlig als P‐Quelle. Als agronomisch interessante P‐Recyclingprodukte erwiesen sich die Magnesium‐ sowie die Magnesium‐Ammonium‐Phosphate. Zur weiteren Absicherung dieser Ergebnisse müssen diese Produkte in verschiedenen Böden sowohl in Gefäß‐ als auch Feldversuchen überprüft werden.
A semi‐analytical model for solute transport in layered dual‐porosity media
Authors: Ilsemann Jan , van der Ploeg Rienk R. , Horton Robert , Hermsmeyer Dirk
Published: December 2006

The vulnerability of groundwater from chemical leaching through soil is a concern at some locations. Because measurements are laborious, time‐consuming, and expensive, simulation models are frequently used to assess leaching risks. But the significance of simulated solute movement through a layered soil is questionable if vertical homogeneity of physical soil properties has been assumed.

In the present study, a semi‐analytical model for solute leaching in soils is presented. The model is relatively simple, but it does account for soil layers having different physical properties. The model includes the mobile‐immobile model (MIM) to describe one‐dimensional (1‐D) nonequilibrium, transient solute transport under steady‐state flow conditions. The MIM is rewritten as a second‐order differential equation and solved by a numerical scheme. Differing from fully analytical or fully numerical solutions, the new approach solves the differential equation numerically with respect to time and analytically with respect to distance.

Numerical experiments for a single layered soil profile show that the semi‐analytical solution (SA‐MIM) is numerically stable for a wide range of parameter values. The accuracy of SA‐MIM predictions is comparable to that of analytical solutions. Numerical experiments for a multilayered profile indicate that the model correctly predicts effluent curves from finite layered soil profiles under steady‐state flow conditions.

The SA‐MIM simulations with typical parameter values suggest that neglecting vertical heterogeneity of flow paths in a layered soil can lead to inaccurate prediction of soil‐solute leaching. The quality of predictions is generally improved if parameter estimates for the different soil layers are considered. However, the mobile‐immobile‐parameter estimates obtained in a number of previous studies may not be transferable to a field situation that is characterized by a slow and steady flow of water. Further field experiments to determine mobile‐immobile parameters under such conditions are desirable.
Measurement modeling of soil‐water dynamics evapotranspiration of drained peatland soils
Authors: Schwärzel Kai , Šimůnek Jirka , van Genuchten Martinus Th. , Wessolek Gerd
Published: December 2006

Natural peat soils serve as important sinks for nutrients, organic components, and water. Peat soils can pose major environmental problems when they are drained for agricultural production, which may change their role in the landscape from a sink to a source. To successfully restore and conserve peat soils, it is important to understand the soil‐moisture dynamics and water demand of drained peat soils for different climate and groundwater conditions. For this purpose, we conducted a series of lysimeter experiments with peat soils subject to different groundwater levels. Evapotranspiration (ET) rates and upward capillary fluxes in peat soils under grass were measured, while TDR probes and tensiometers were used to monitor the soil‐water dynamics in the lysimeter during the growing season. The lysimeter data were simulated using an extended version of HYDRUS‐1D to enable ET calculations using the Penman‐Monteith equation. A physically based approach was tested to predict the canopy resistance as a function of the average pressure head of the soil root zone. The numerical simulations closely followed the observed soil‐moisture dynamics in the lysimeter and were consistent with measured differences in ET rates for different groundwater levels. Besides average climate conditions, the effects of extreme dry and wet weather conditions on ET and groundwater recharge during the growing season were evaluated using the calibrated numerical model for different groundwater levels. Evapotranspiration rates during dry years depended very much on upward capillary flow from the water table and hence on the soil hydraulic properties. During wet years, however, ET was controlled mostly by the evaporative demand of the atmosphere, and much less by the soil hydraulic properties.
Microbial biomass activities in urban soils in two consecutive years
Authors: Lorenz Klaus , Kandeler Ellen
Published: December 2006

Ecological soil functions are protected in Germany. Thus, for the sustainable use of urban soil resources data on the function of soils to serve as a habitat are required. Soil microbial biomass and activities were studied in two surface horizons in two consecutive years at nine sites in Stuttgart, Germany, differing in land use. Microbial biomass (chloroform‐fumigation extraction, substrate‐induced respiration) and microbial activities (potential N mineralization, potential ammonium oxidation, and enzyme activities of dehydrogenase, urease, arylsulfatase, and phosphatase) were determined in 2001 and 2002. DIN/ISO standard methods were applied as far as they were available. Furthermore, soil chemical properties were determined in the 2001‐samples. Large differences in chemical and microbiological properties among surface horizons were found. Concentrations of microbial biomass and microbial activities were, however, often comparable to agricultural or forest surface soils. The lowest microbial biomass and activities were observed at a highly disturbed railway area where vegetation was missing and total organic C (TOC) had been altered by anthropogenic organic particles. In contrast, microorganisms were promoted at vegetated sites and where organic impurities were negligible. As TOC was altered by obscure organic matter, total N (TN) and not TOC closely correlated with soil microbiological properties. Biomass and activity generally decreased with depth, but mixing of organic matter resulted in more uniform depth distribution of microbial properties in one garden soil. In 2002, microbial biomass and activity were often lower compared to 2001, but interpretation of this difference hampered as the number of samples taken was probably not sufficient to address the spatial variability in soil properties. Additional studies are needed to develop simple and cost‐effective procedures for the evaluation of ecological quality of urban soils by combined efforts of city planners and soil scientists.
Performance differences across strategic groups: an examination of financial market‐based performance measures
Authors: Pandian J. Rajendran , Thomas Howard , Furrer Olivier , Bogner William C.
Published: December 2006

One of the more interesting issues in the strategic management field is the question of whether intra‐industry performance differences exist, particularly across strategic groups. Most of the existing studies have used accounting measures of performance despite the documented weaknesses of such measures. This paper examines whether financial market‐based measures of performance are superior to accounting‐based measures in identifying performance differences across strategic groups.

Hypotheses are tested on data from an existing sample of firms in the US pharmaceutical industry. The empirical results indicate that performance differences are more likely to exist across strategic groups when financial market performance measures are used. Suggestions for further refinements are made and limitations of the study are discussed.

Copyright © 2006 John Wiley & Sons, Ltd.
Business scope and competitive differentiation: a study of strategy consistency
Authors: Pehrsson Anders
Published: December 2006

Obstacles to strategy implementation and change are often due to limited consistency between the choices that a firm has to make regarding business scope and differentiation.

The purpose of this paper is to identify relationships between business scope and competitive differentiation in industrial firms. It reports on managerial perceptions within a sample of business units of Swedish manufacturing firms in Germany, the United Kingdom and the United States.

The study found that standardized products offered to just a few market segments are associated with an emphasis on product differentiation but that this strategy causes negative performance effects. In contrast, penetration of many segments is associated with customer flexibility attributes, yielding positive results.

The study contributes to our understanding of strategy consistency by establishing associations between business scope and competitive differentiation. Management advice is presented.

Copyright © 2006 John Wiley & Sons, Ltd.
Two‐sided surface roughness and hydrodynamic pressure distribution in lubricating films
Authors: Burstein Leonid
Published: December 2006

A spatial one‐dimensional time‐dependent mathematical model of roughened sliding surfaces with a sinusoidal profile was developed and applied in the context of their fluid lubrication. The opposing surfaces have identical average roughness and wavelength characteristics. The hydrodynamic pressure distribution equation is derived for different peak‐hollow numbers and roughness depths. Matlab (the Mathworks, Inc., Natick, MA, USA) calculations show a significant effect of roughness with a small number of peak‐hollow waves on the above parameter. The effect becomes less significant as the number of waves increases, and practically vanishes between the 1000–40000 level at all roughnesses from 0.1 to 0.4. Copyright © 2006 John Wiley and Sons, Ltd.
Gradient Density Grafted Polymers on Ground Tire Rubber Particles by Atom Transfer Radical Polymerization
Authors: Coiai Serena , Passaglia Elisa , Ciardelli Francesco
Published: December 2006

Summary: The graft polymerization of styrene and (meth)acrylic monomers via ATRP from cross‐linked rubber particles, produced by recycled tires (“ground tire rubber”, GTR), is reported. GTR particles, obtained by cryogenic grinding process, still contain CC unsaturations on the surface, which were first oxidized to hydroxyl groups and then modified by reaction with 2‐bromoisobutyryl bromide to serve as ATRP macroinitiators. Graft polymerizations were carried out using CuBr/CuBr2/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as catalytic system in bulk or in anisole at high temperature. The grafted particles were analyzed by ATR‐IR (spectra were recorded on particles surface and cross‐sectional slices), TGA, SEM and X‐ray microanalysis.

Arrangement of surface‐grafted polymer assemblies along the particles section.

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Arrangement of surface‐grafted polymer assemblies along the particles section.
Functionalization and Linking Chemistry of Poly(styryl)lithium with 1,3‐Butadiene Diepoxide
Authors: Quirk Roderic P. , Contractor Asfiya , Polce Michael J. , Wesdemiotis Chrys
Published: December 2006

Summary: The reaction of excess poly(styryl)lithium ($\overline M _{\rm n}$ = 1 400 g · mol−1) with 1,3‐butene diepoxide proceeds efficiently to produce a coupled product with two in‐chain hydroxyl groups. The pure coupled, functionalization product was isolated in quantitative yield by silica gel column chromatography. This product was characterized by 1H and 13C NMR spectroscopic analyses, as well as MALDI‐TOF mass spectrometry. The DEPT 13C NMR spectrum showed that a disecondary 1,2‐diol unit was present, consistent with attack of PSLi on the least‐substituted, methylene carbons of 1,3‐butadiene diepoxide. The MALDI‐TOF mass spectrum of the purified product exhibited only one distribution with monoisotopic peaks corresponding to the coupled, dihydroxy‐functionalized polystyrene.

MALDI‐TOF mass spectrum of the purified, in‐chain, hydroxyl‐functionalized polystyrene and the reaction of PSLi with 1,3‐butadiene diepoxide.

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MALDI‐TOF mass spectrum of the purified, in‐chain, hydroxyl‐functionalized polystyrene and the reaction of PSLi with 1,3‐butadiene diepoxide.
Kerbgrundkonzepte für die schwingfeste Auslegung von Aluminiumschweißverbindungen am Beispiel der naturharten Legierung AlMg4,5Mn (AW‐5083) und der warmausgehärteten Legierung AlMgSi1 T6 (AW‐6082 T6)
Authors: Morgenstern C. , Hanselka H.
Published: December 2006

Örtliche Kerbspannungskonzepte auf Basis von werkstoff‐ und gefügespezifischen Kennwerten, wie das Mikrostützwirkungskonzept, weisen Schwächen in der praktischen Anwendbarkeit auf. Anhand von Schwingfestigkeitsergebnissen mit verschiedenen MIG‐Aluminiumschweißverbindungen der Legierungen AlMg4,5Mn (AW‐5083) und AlMgSi1 T6 (AW‐6082 T6) unter wechselnder und schwellender Beanspruchung wird das Mikrostützwirkungskonzept dem Kerbspannungskonzept mit einem fiktiven Ersatzradius gegenübergestellt. Die Auswertung der Ergebnisse zeigt, dass das örtliche Kerbspannungskonzept mit einem fiktiven Ersatzradius von rf = 1,0 mm auf Aluminiumschweißverbindungen mit Dicken von t ≥ 5 bis 25 mm angewendet werden kann, wobei es unabhängig von der Legierung und der Schweißnahtgeometrie (Stumpfstoß mit und ohne Wurzelspalt, Quersteife) ist. Es werden Master‐Wöhlerlinien für verschiedene Spannungsverhältnisse, R = ‐1, 0 und 0,5, vorgeschlagen, die eine Berücksichtigung sowohl von Eigenspannungen als auch belastungsinduzierten Mittelspannungen zulassen. Darüberhinaus wird aus den Ergebnissen der Vorschlag von Δσ = 70 MPa als FAT‐Klasse für das IIW‐Regelwerk abgeleitet.
Conformational and tautomeric eccentricities of 2‐acetyl‐1,8‐dihydroxynaphthalenes
Authors: Hansen Poul Erik , Kamounah Fadhil S. , Hansen Bjarke K. V. , Spanget‐Larsen Jens
Published: December 2006

Tautomerism in aromatic systems with oxygen substitutents is rare. This is investigated in 2‐acetyl‐1,8‐dihydroxy‐3,6‐dimethylnaphthalene (1) and in 2,7‐diacetyl‐1,8‐dihydroxy‐3,6‐dimethylnaphthalene (2). The tautomeric nature of 2‐acetyl‐1,8‐dihydroxy‐3,6‐dimethylnaphthalene is supported by long‐range hydrogen–hydrogen coupling between the OH‐1 and the OH‐8 and by the isotope effects on 13C caused by deuteration at the CH3CO methyl group. Compound 2 participates in a degenerate equilibrium between two equivalent nonsymmetrical rotamers (2A and 2B), each having two intramolecular O···HO hydrogen bonds: one involving an acetyl oxygen and the neighboring hydroxyl group, and the other between the oxygen centers at positions 1 and 8. In addition, each rotamer is involved in a tautomeric equilibrium, with a structure having an OH‐substituted exocyclic double bond (2AT or 2BT).

DFT calculations for a large set of compounds highlight the factors controlling the unusual rotational and tautomeric behaviors. A very important factor seems to be the repulsive interaction between the O‐1 and O‐8 centers, which is modulated by formation of an OH‐1···O‐8 or OH‐8···O1 hydrogen bond. Steric interactions, mesomeric release of electrons from the oxygen at position 8, and a strong OH···O···C hydrogen bond are other factors.

Solid‐state 13C NMR spectra of 2,7‐diacetyl‐1,8‐dihydroxy‐3,6‐dimethylnaphthalene at different temperatures demonstrated no averaging in the solid, whereas partially deuterated 2‐acetyl‐1,8‐dihydroxy‐3,6‐dimethylnaphthalene showed an isotope effect at C‐1 of 1.5 ppm, indicating tautomerism in the solid state. Copyright © 2006 John Wiley & Sons, Ltd.
15N NMR study of substituted 2‐(phenylamino)‐5‐phenyl‐1,3,4‐oxadiazoles
Authors: Gierczyk Błażej , Nowak‐Wydra Barbara , Grajewski Jakub , Zalas Maciej
Published: December 2006

Substituted 2‐(phenylamino)‐5‐phenyl‐1,3,4‐oxadiazoles were studied by 15N NMR spectroscopy. All signals were assigned on the basis of HMQC and HMBC experiments. Chemical shifts values were correlated with empirical Hammett parameters as well as with calculated electron densities and chemical shieldings. Copyright © 2006 John Wiley & Sons, Ltd.
1H and 13C NMR studies of 2‐functionalized 5‐(methylsulfonyl)‐1‐phenyl‐1H‐indoles
Authors: Cruz‐López Olga , Gallo Miguel A. , Espinosa Antonio , Campos Joaquín M.
Published: December 2006

The 1H and 13C NMR resonances of thirty 2‐functionalized 5‐(methylsulfonyl)‐1‐phenyl‐1H‐indoles were assigned completely and unequivocally using the concerted application of one‐ and two‐dimensional experiments (DEPT, gs‐HMQC and gs‐HMBC). Finally, the influence of the 2‐substituent of 5‐(methylsufonyl)‐1‐phenyl‐1H‐indoles on the carbon atoms of the indole moiety was estimated. Copyright © 2006 John Wiley & Sons, Ltd.
Is spinal cord isolation a good model of muscle disuse?
Authors: Roy R. R. , Zhong H. , Khalili N. , Kim S. J. , Higuchi N. , Monti R. J. , Grossman E. , Hodgson J. A. , Edgerton V. R.
Published: December 2006

The patterns of normal daily activity that are required to maintain normal skeletal muscle properties remain unknown. The present study was designed to determine whether spinal cord isolation can be used as a reliable experimental model of neuromuscular inactivity, that is, as a baseline for the absence of activity. Electromyograms (EMGs) were recorded from selected hindlimb muscles of unanesthetized rats over 24‐hour periods before and 7, 30, 60, and 90 days after surgical isolation of the lumbar spinal cord. Our data indicate that some rat slow muscle fibers pre‐surgery were activated for less than 3 hours per day. Spinal cord isolation (SI) reduced the mean daily integrated EMG (IEMG) and daily EMG duration in the primary slow extensor muscle (soleus) to <1% of control, and in the primary fast extensor muscles [medial gastrocnemius (MG) and vastus lateralis (VL)] to <2% of control. These parameters were decreased to <8% and 3% of control, respectively, in a primary fast flexor muscle, the tibialis anterior (TA). From 30 to 90 days post‐SI, the mean amplitudes of the spontaneous EMG bursts were relatively normal in the soleus, increased ∼2‐fold in the MG and VL, and increased ∼4‐fold in the TA. Some evidence of the normal antagonistic flexor–extensor relationship was apparent in the brief periods of recorded activity post‐SI. These results indicate that SI eliminates nearly all of the normal EMG activity in the hindlimb muscles in the presence of relatively normal muscle innervation and functional intraspinal neural circuitry. Muscle Nerve, 2006
Improvement in fetal DNA extraction from maternal plasma. Evaluation of the NucliSens Magnetic Extraction system and the QIAamp DSP Virus Kit in comparison with the QIAamp DNA Blood Mini Kit
Authors: Clausen Frederik Banch , Krog Grethe Risum , Rieneck Klaus , Dziegiel Morten Hanefeld
Published: December 2006

Objective

Prenatal diagnostic assays have been developed using free fetal DNA circulating in the maternal blood of pregnant women. Efficient DNA extraction is crucial for a robust analysis. To improve fetal DNA yield, we tested two manual extraction methods—the NucliSens Magnetic Extraction (NMAG) system and the QIAamp DSP Virus Kit (QDSP)—against our current standard method, the widely used QIAamp DNA Blood Mini Kit (QDNA).

Methods

The fetal DNA yield of the two extraction systems was evaluated using the RHD exon 7 as target in DNA extracts of 75 plasma samples from pregnant RhD‐negative women, known to have given birth to RhD‐positive infanto. The total DNA yield was evaluated in 23 samples, targeting GAPDH.

Results

The fetal DNA yield was improved by a mean factor of 1.7 using the NMAG system, and improved by a mean factor of 1.5 using the QDSP.

The total DNA yield was improved by a mean factor of 2.3 using the NMAG system, and by a mean factor of 1.3 using the QDSP.

Conclusion

Both extraction systems tested were superior to our standard with regard to DNA yield. This improvement may have a great impact on the success of genotyping in early pregnancy. Copyright © 2007 John Wiley & Sons, Ltd.
Fetal anomaly scan potentially will replace routine AFAFP assays for the detection of neural tube defects
Authors: Kooper Angelique J. A. , de Bruijn Dagmar , van Ravenwaaij‐Arts Conny M. A. , Faas Brigitte H. W. , Creemers Johan W. T. , Thomas Chris M. G. , Smits Arie P. T.
Published: December 2006

Objectives

Introduction of the second‐trimester fetal anomaly scan and the decision to offer this scan to every woman in the 18th–22nd week of pregnancy necessitates a re‐evaluation of the diagnostic value of the measurement of α‐fetoprotein (AFP) concentrations in the amniotic fluid (AF) for the detection of neural tube defects (NTDs).

Methods

In this study of 6501 women who underwent amniocentesis, amniotic fluid AFP (AFAFP) concentrations were measured. The women were divided into three categories: group I, without any increased risk of fetal NTD (N = 6188); group II, with an increased risk of fetal NTD (N = 258); and group III, with a clinically diagnosed fetal NTD with known AFAFP concentrations (N = 55).

Results

In 27 women of group I (0.4%), the MoM (multiple of the median) level was > 2.5 times the median AFP concentration for the corresponding gestational age, and in two fetuses this was related to NTD. In two pregnancies of group II (0.8%), an increased AFAFP was related to NTD. In group III, 44 of the 55 (80%) samples had an increased AFAFP.

Conclusion

In the near future, it is likely that imaging will replace AFAFP assays for the detection of fetal NTDs because high quality ultrasound imaging will detect NTDs accurately. Copyright © 2007 John Wiley & Sons, Ltd.
Ultrasound findings before amniocentesis in selecting the method of analysing the sample
Authors: Kagan Karl O. , Chitty Lyn S. , Cicero Simona , Eleftheriades Makarios , Nicolaides Kypros H.
Published: December 2006

Objective

To determine if the primary method of cytogenetic analysis in pregnant women undergoing amniocentesis should be quantitative fluorescent polymerase chain reaction (qf‐PCR), with karyotyping being performed only on those with abnormal ultrasound findings.

Methods

Amniocentesis was performed in 3854 cases. The median maternal age was 36 years and median gestational age was 18 weeks. The indication for karyotyping was an increased risk for aneuploidy in the absence or presence of sonographic abnormalities detected at the scan before amniocentesis. All samples were analysed by qf‐PCR and full karyotyping. For each detectable fetal defect, the positive or negative likelihood ratio for aneuploidy was determined.

Outcome Measure

Detection rate of clinically significant chromosomal abnormalities.

Results

The karyotype was normal in 3617 (93.9%) cases. In 237 (6.1%) cases, the karyotype was abnormal and the detection rate by qf‐PCR was 92.4%. A policy of performing qf‐PCR in all cases and karyotyping in only those with combined likelihood ratios of > 1, > 3, and > 5 would detect 98.3, 96.6, and 95.4% of all chromosomal abnormalities and would require karyotyping in 16.1, 8.0, and 5.4% of the cases, respectively.

Conclusions

More than 95% of the aneuploidies can be detected if karyotyping is performed in addition to qf‐PCR in about 15% of the cases selected on the basis of ultrasound findings before amniocentesis. Copyright © 2007 John Wiley & Sons, Ltd.
Fetus‐in‐fetu: confirmation of prenatal diagnosis with MRI
Authors: Coolen Jillian , Bradshaw Barbra , Bhargava Ravi , Lees Gordon , Demianczuk Nestor
Published: December 2006

Fetus‐in‐fetu is a rare form of monozygotic diamniotic twin pregnancy in which one fetus is enclosed within its twin (Khadarooet al., 2000). This case report highlights the use of prenatal MRI to confirm prenatal diagnosis of an intra‐abdominal FIF to aid obstetricians, neonatologists, and pediatric general surgeons in perinatal and surgical management. Copyright © 2007 John Wiley & Sons, Ltd.
Organic base‐catalyzed sol–gel route to prepare PMMA–silica hybrid materials
Authors: Yeh Jui‐Ming , Hsieh Chi‐Fa , Yeh Chia‐Wen , Wu Mei‐Jyun , Yang Hsing‐Chung
Published: December 2006

A series of sol–gel‐derived organic–inorganic hybrid materials that comprise organic poly(methyl methacrylate) (PMMA) and inorganic silica (SiO2) was successfully prepared using aniline as an organic base catalyst to catalyze the sol–gel reactions of tetraethylorthosilicate (TEOS). Aniline was adopted not only as a catalyst but also as a dispersing agent during the preparation of the hybrid materials. The as‐prepared hybrid materials were then characterized using transmission electron microscopy, SEM/energy dispersive X‐ray spectroscopy and Fourier transform infrared spectroscopy. The characteristic temperatures (including Td and Tg) of the hybrid materials slightly exceeded those of neat PMMA, as revealed from thermogravimetric analysis and differential scanning calorimetry evaluations. Studies of the protection against corrosion demonstrated that the hybrid coatings all improved the protection performance on cold‐rolled steel coupons relative to that of neat PMMA coatings, according to measurements of electrochemical corrosion parameters. Additionally, incorporating silica particles into the polymer may effectively reduce the gas permeability of the polymer membrane. Reducing the size of silica particles (at the same silica feeding) further improved the gas barrier property. Optical clarity studies indicated that introducing silica particles into the PMMA matrix may slightly reduce the optical clarity of the films/membranes, as determined by UV‐visible transmission spectroscopy. The contact angle of H2O of the hybrid films increased with the amount of aniline. Copyright © 2006 Society of Chemical Industry Society of Chemical Industry
Proteomic analysis of human very low‐density lipoprotein by two‐dimensional gel electrophoresis and MALDI‐TOF/TOF
Authors: Mancone Carmine , Amicone Laura , Fimia Gian Maria , Bravo Elena , Piacentini Mauro , Tripodi Marco , Alonzi Tonino
Published: December 2006

Biochemical studies of lipoproteins have shed light on their composition, highly contributing to the comprehension of their function. Due to the complexity of their structure, however, an in‐depth structural analysis, in terms of components and PTMs, may still unravel important players in physiological and pathological processes of lipid metabolism. In this study, we performed a protein map of very low‐density lipoprotein (VLDL) using a 2‐DE MALDI‐TOF/TOF proteomic approach. Several VLDL‐associated apolipoproteins were identified, including five isoforms of apoE, three isoforms of apoC‐IV, and one isoform each of apoC‐III, apoM, apoA‐I, and apoA‐IV. Notably, we also identified seven isoforms of apoL‐I and two isoforms of prenylcysteine lyase as new VLDL‐associated proteins. Furthermore, we were able to identify PTM of apoE, which was found to be differently O‐glycosylated at Thr212 residue, and PTM of apoL‐I which we described, for the first time, to be phosphorylated at Ser296. While the physiological relevance of our finding remains to be assessed, we believe that our results will be useful as reference for future studies of VLDL structure in specific physiopathological conditions.
AFM fishing nanotechnology is the way to reverse the Avogadro number in proteomics
Authors: Archakov Alexander Ivanovich , Ivanov Yurii Dmitrievich , Lisitsa Andrey Valerevich , Zgoda Victor Gavrilovich
Published: December 2006

Future development of proteomics may be hindered by limitations in the concentration sensitivity of widespread technological approaches. The concentration sensitivity limit (CSL) of currently used approaches, like 2‐DE/LC separation coupled with MS detection, etc., varies from 10−9 to 10−12 M. Therefore, proteomic technologies enable detection of up to 20% of the protein species present in the plasma. New technologies, like atomic force microscopy (AFM molecular detector), enable the counting of single molecules, whereas biospecific fishing can be used to capture these molecules from the biomaterial. At the same time, fishing also has thermodynamic limitations due to the reversibility of the binding. In cases where the fishing becomes irreversible, its combination with an AFM detector enables the registration of single protein molecules, and that opens up a way to lower the CSL down to the reverse Avogadro number.
Synthesis and characterization of a main‐chain‐type conjugated copolymer containing rare earth with photocrosslinkable group
Authors: Wen Gui‐An , Zhu Xing‐Rong , Wang Lian‐Hui , Feng Jia‐Chun , Zhu Rui , Wei Wei , PEng Bo , Pei Qi‐Bing , Huang Wei
Published: December 2006

In this article, we report the design, synthesis, and characterization of a new main‐chain‐type rare earth‐containing conjugated polymer with photocrosslinkable group. The polymer is crosslinked photochemically by the addition of a photoinitiator to yield an absolute insoluble network. The optical properties of the resulting conjugated polymer were characterized in solution, film state, and after photocrosslinking. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 388–394, 2007.
Synthesis and characterization of diphenylaminodiphenyl stryl based alternating copolymers
Authors: Zhao Qinghua , Kim Yun‐Hi , Dang Thi Tuyet Mai , Shin Dong‐Cheol , You Hong , Kwon Soon‐Ki
Published: December 2006

Diphenylaminobiphenylated stryl based alternating copolymers with phenyl or fluorene, which were expected to have a terphenylene vinylene backbone containing an (N,N‐diphenylamino)biphenyl pendant and a phenyl/fluorene/phenylene vinylene backbone containing an (N,N‐diphenylamino)biphenyl pendant, were synthesized by a Suzuki coupling reaction. The obtained copolymers were confirmed with various types of spectroscopy. The alternating copolymers showed good hole‐injection properties because of their low oxidation potential and good solubility and high thermal stability with a high glass‐transition temperature. The alternating copolymers showed blue emissions because of the adjusted conjugation lengths; the maximum wavelength was 460 nm for poly{4,4′‐biphenylene‐α‐[4″‐(N,N′‐diphenylamino)diphenyl]vinylene‐alt‐5‐(2′‐ethylhexyloxy)‐2‐methoxybenzene} and 487 nm for poly{4,4′‐biphenylene‐α‐[4″‐(N,N′‐diphenylamino)diphenyl] vinylene‐alt‐9,9‐dihexylfluorene}. The maximum brightness of indium tin oxide/poly(3,4‐ethylene dioxythiophene)/polymer/LiF/Al devices with poly{4,4′‐biphenylene‐α‐[4″‐(N,N′‐diphenylamino)diphenyl]vinylene‐alt‐5‐(2′‐ethylhexyloxy)‐2‐methoxybenzene} or poly{4,4′‐biphenylene‐α‐[4″‐(N,N′‐diphenylamino)diphenyl]vinylene‐alt‐9,9‐dihexylfluorene} as the emitting layer was 250 or 1000 cd/m2, respectively. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 341–347, 2007
Comparison of wind tunnel and field experiments to measure potential deposition of fenpropimorph following volatilisation from treated crops
Authors: Hassink Jan , Platz Klaus , Stadler Reinhold , Zangmeister Werner , Fent Gunnar , Möndel Martin , Kubiak Roland
Published: December 2006

The potential for short‐range transport via air, i.e. volatilisation from the area of application and subsequent deposition on adjacent non‐target areas, was investigated for the fungicide fenpropimorph in a wind tunnel system and under outdoor conditions in a higher‐tier field study. Fenpropimorph 750 g L−1 EC was applied post‐emergence to cereal along with a reference standard lindane EC. Stainless steel containers of water were placed at different distances downwind of the application area to trap volatile residues during a study period of 24 h following application. Meteorological conditions in the wind tunnel as well as on the field were constantly monitored during the study period. The wind tunnel system was a partly standardised system on a semi‐field scale, i.e. wind direction and wind speed (2 m s−1) were constant, but temperature and humidity varied according to the conditions outside. In the field experiment, the average wind speed over the 24 h study period was 3 m s−1 and no rainfall occurred. Three different measuring lines were installed on the non‐target area beside the treated field to cover potential variations in the wind direction. However, no significant differences were observed since the wind direction was generally constant. Fenpropimorph was detected in minor amounts of 0.01–0.05% of the applied material in the wind tunnel experiment. Even at a distance of 1 m beside the treated field, no significant deposition occurred (0.04% of applied material after 24 h). In the field, less than 0.1% of the applied fenpropimorph was detected at 0 m directly beside the treated field. At 5 m distance the deposition values were below 0.04%, and at 20 m distance about 0.01%. In general, the amounts of deposited fenpropimorph detected in the partly standardised wind tunnel system and the higher‐tier field study were in good agreement. Copyright © 2006 Society of Chemical Industry
Symmetry of trion states in modulation‐doped CdTe/CdMgTe nanostructures under a high magnetic field
Authors: Tronc P. , Andronikov D. , Kochereshko V. , Crooker S. A. , Karczewski G.
Published: December 2006

Photoluminescence (PL) spectra of modulation‐doped CdTe/CdMgTe quantum‐well structures containing two dimensional electron gases with electron concentrations around 1010 cm–2 have been recorded under a high magnetic field up to 45 T. Radiative recombination lines of dark and bright triplet trion states were found in the spectra at magnetic field strengths larger than 20 T. A model that takes into account the full symmetry of the structure under the magnetic field fits all the experimental results. Recording reflectivity spectra confirms the proposed model and the results from PL experiments. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antiinflammatory and antiulcer properties of tannins from Myracrodruon urundeuva Allemão (Anacardiaceae) in Rodents
Authors: Souza S. M. C. , Aquino L. C. M. , Jr A. C. Milach , Bandeira M. A. M. , Nobre M. E. P. , Viana G. S. B.
Published: December 2006

Myracrodruon urundeuva Allemão is a plant utilized in Northeast Brazil as an antiinflammatory, wound healing and in gynecological illnesses. The objectives of the present study were to evaluate the antiinflammatory and antiulcer properties of the tannin‐enriched fraction (TEF) isolated from the stem bark of M. urundeuva, in the formalin test, in mice, and in carrageenan‐induced paw edema and gastric ulcer models, in rats. The results showed that TEF dose‐dependently inhibited both phases of the formalin test. However, the effect was predominant in the 2nd phase of the response where inhibitions of 47%, 76% and 85% were observed, with doses of 5, 10 and 50 mg/kg, i.p. In the carrageenan‐induced paw edema, significant inhibitions were observed at 3 h (44%) and 4 h (28%), with a dose of 10 mg/kg, i.p. TEF also significantly decreased by 37%, 43% and 57% gastric ulceration induced by indomethacin, at doses of 10, 20 and 50 mg/kg p.o. In the ethanol‐induced gastric ulcer model, TEF was less effective, and significant inhibitions (42% to 46%) were observed only with doses of 100 and 200 mg/kg, p.o., respectively. In conclusion, it was shown that TEF presents antiinflammatory and antiulcer effects, partly due to its antioxidant action, known to be present in polyphenols, including tannins. Copyright © 2006 John Wiley & Sons, Ltd.
Ginkgo biloba extract protects against alcohol‐induced liver injury in rats
Authors: Yuan Guangjin , Gong Zuojiong , Li Junhua , Li Xi
Published: December 2006

Ginkgo biloba extract has been shown to be hepatoprotective. However, its benefits when used in alcoholic liver injury have not been demonstrated. This study investigated the effects of Ginkgo biloba extract on alcohol‐induced liver injury in a chronic alcohol plus fish oil gavage model in rats.

Liver injury was evaluated histologically and by serum alanine aminotransferase (ALT). Liver tumor necrosis factor‐alpha (TNF‐alpha) protein levels, malondialdehyde (MDA) and glutathione (GSH) contents were determined. TNF‐alpha mRNA expression in the liver was analysed by reverse transcriptase‐polymerase chain reaction (RT‐PCR).

Rats given fish oil plus alcohol developed macrovesicular and microvesicular steatosis, spotty necrosis and mild inflammation in the liver and elevated serum ALT levels, which were accompanied by increased MDA contents, reduced GSH contents and elevated TNF‐alpha protein and mRNA expressions in the liver. Supplementation with Ginkgo biloba extract (200 mg/kg, orally) improved the liver injury, blunted the rises of MDA contents and TNF‐alpha expression, and restored the GSH content in the liver.

Ginkgo biloba extract protects against alcohol‐induced liver injury, and the mechanism may involve a reduction of lipid peroxidation, prevention of GSH depletion and inhibition of TNF‐alpha expression in the liver. Copyright © 2006 John Wiley & Sons, Ltd.