bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of soil microorganisms on the sorption of zinc and lead compounds by goethite
Authors: Perelomov Leonid , Kandeler Ellen 
Published: January 2006

AbstractThe objectives of this study were (1) to determine the effect of microorganisms during in‐vitro incubation on the amount of Zn and Pb from solution retained on goethite precipitated as coatings on a sand matrix and (2) to evaluate accumulation of heavy metals in the biomass of soil microorganisms in the fresh soil samples using an extractive approach. A mixture of colonies of cultivated microorganisms extracted from a Haplic Luvisol (Russia) and an Antropi‐urbic Regosol (Germany) were used to prepare the cell and the microbial‐debris suspensions. The concentrations of Zn and Pb in the studied solutions supplied with microbial suspensions and/or goethite coated sand were 0.1 mM (130.8 and 414 mg kg–1 of sand, respectively). Exchangeable forms of metals were determined by extraction with 10 mL of 1.0 M KNO3. Nonexchangeable forms of Zn and Pb were recovered using 40 mL of 0.3 M NH2OH‐HCl in 1 M HNO3. Concentrations of Pb increased in the solutions and decreased on the surface of the Fe‐mineral due to living microorganisms. In comparison to incubation of heavy‐metal solutions with goethite only, the absolute concentrations of nonexchangeable forms of metal were reduced by microbial suspension to a greater extent than those of the exchangeable forms, whereas the relative content of both fractions decreased by a factor of almost two. Sorption of Pb by goethite was inversely correlated with the concentration of organic C in the solution. Microorganisms clearly influenced the Zn sorption by goethite at concentrations of Corg > 400 mg L–1. The amount of Zn retained was decreased primarily due to decreasing Zn portions in the exchangeable fraction. Microbial debris prepared by autoclaving reduced the Pb sorption by goethite similar to the results for living cells. Living microorganisms accumulated more Zn than did microbial debris. The data of this paper show that a direct determination of heavy‐metal accumulation in soil microorganisms by extraction with 2.0 M KCl as well as by extraction with 1 M CH3COONH4 at the natural pH of the soils after chloroform fumigation of fresh soils samples with different concentrations of organic C was not possible.
Determination of micronutrients and heavy metals in soils using electro–ultrafiltration (EUF) technique by addition of DTPA
Authors: Horn Dietmar 
Published: January 2006

AbstractWith the electro–ultrafiltration (EUF) technique, the plant availability of several plant nutrients in soils can be characterized. The basic principle of EUF is that an electric field is induced using platinum electrodes. Ions in the soil suspension move either to the cathode or to the anode and are filtrated through ultra‐membrane filters. In the standard EUF procedure, two extractions steps are used: 30 min at 20°C and 5 min at 80°C. However, the determination of micronutrients and heavy metals with the standard EUF procedure is not possible, because the solubility of these elements in water is low and most of the watersoluble elements are precipitated when passing the platinum electrodes.The addition of DTPA, a well known complexing agent, during a third EUF fraction (5 min at 80°C) enables extraction of micronutrients and heavy metals. Highest concentrations in the 33 soils of the study were found for iron, followed by zinc, manganese, lead, copper, and nickel. Lower concentrations were obtained for cobalt, chromium, cadmium, and molybdenum. For two soils, the EUF/DTPA procedure was compared to CaCl2/DTPA and EDTA soil extraction methods, showing that higher or comparable amounts were found with CaCl2/DTPA and much higher amounts with the EDTA method.These results reveal that the EUF/DTPA technique in principle can be used for the determination of plant‐available micronutrients and heavy metals. However, in a next step the relationship between EUF/DTPA‐extractable elements and their availability for plants needs to be quantified.
Biodegradability of dissolved organic matter extracted from a chronosequence of forest‐floor materials
Authors: Bourbonniere Richard A. , Creed Irena F. 
Published: January 2006

AbstractDissolved organic matter (DOM) is an important part of the microbially utilizable organic matter in soils. This paper describes an incubation experiment by which the lability and mobility of DOM extracted from forest‐floor materials are related to their age and degree of degradation. DOM extracted from a chronosequence of decomposing leaves (green leaves, fresh fallen leaves, litter [1 y weathering], fibric matter [2–3 y], hemic matter [>3 y], or peat [100+ y]) was applied to intact soil cores, and the CO2 produced over 5 d was measured to determine biodegradability. Biodegradability of DOM varied somewhat along the chronosequence, with the green leaves yielding more CO2 on an equal C basis than the older substrates and equivalent to glucose which was used as a reference substrate. Thus, the DOM extracts of the older substrates contain some refractory components. The humic‐acid content (or that of its precursors) of the extracts from older substrates relates to the lowered lability. The hydrophobic and hydrophilic content of DOM extracted from substrates was not related to CO2 production in the incubation studies conducted.
Microbial biomass and activity under oxic and anoxic conditions as affected by nitrate additions
Authors: Dyckmans Jens , Flessa Heiner , Lipski André , Potthoff Martin , Beese Friedrich 
Published: January 2006

AbstractSoil microbial activity, biomass, and community structure were examined during the transition from oxic to anoxic conditions after the addition of glucose and with or without nitrate addition. In two sets of treatments, samples were incubated for up to 35 d in closed ampoules either aerobically until oxygen was depleted or anoxically throughout the experiment. Heat‐flow rate was monitored to indicate microbial activity. Microbial biomass and community structure were measured by adenylate and phospholipid fatty acid (PFLA) content, and adenylate energy charge (AEC) was used to monitor the physiological status of the microbial biomass.Microbial activity was highest under oxic conditions and abruptly decreased under anoxic conditions. Activity peaks were observed after about 9 d of anoxic conditions probably triggered by increased nutrient availability from dying microbial biomass, but these peaks were smaller after initial oxic incubation or nitrate addition. Microbial biomass was unchanged under oxic conditions but decreased under anoxic conditions. Most surviving microbes switched into dormancy. Changes in the microbial‐population structure were small and occurred only after 9 d of anoxic incubation. The results show that the nutrient status and the availability of electron acceptors such as nitrate were important factors ruling the direction and the extent of shifts in the microbial activity and community structures due to anoxic conditions.
Response of the sorption behavior of Cu, Cd, and Zn to different soil management
Authors: Lair Georg J. , Gerzabek Martin H. , Haberhauer Georg , Jakusch Michael , Kirchmann Holger 
Published: January 2006

AbstractThis study investigated the effect of different farming practices over long time periods on the sorption‐desorption behavior of Cu, Cd, and Zn in soils. Various amendments in a long‐term field experiment over 44 y altered the chemical and physical properties of the soil. Adsorption isotherms obtained from batch sorption experiments with Cu, Cd, and Zn were well described by Freundlich equations for adsorption and desorption. The data showed that Cu was adsorbed in high amounts, followed by Zn and Cd. In most treatments, Cd ions were more weakly sorbed than Cu or Zn. Generally, adsorption coefficients KF increased among the investigated farming practices in the following order: sewage sludge ≤ fallow < inorganic fertilizer without N ≈ green manure < peat < Ca(NO3)2 < animal manure ≤ grassland/extensive pasture. The impact of different soil management on the sorption properties of agricultural soils for trace metals was quantified. Results demonstrated that the soil pH was the main factor controlling the behavior of heavy metals in soil altered through management. Furthermore, the constants KF and n of isotherms obtained from the experiments significantly correlated with the amount of solid and water‐soluble organic carbon (WSOC) in the soils. Higher soil pH and higher contents of soil organic carbon led to higher adsorption. Carboxyl and carbonyl groups as well as WSOC significantly influenced the sorption behavior of heavy metals in soils with similar mineral soil constituents.
Phosphorus‐31–nuclear magnetic–resonance spectroscopy to trace organic dung phosphorus in a temperate grassland soil
Authors: Bol Roland , Amelung Wulf , Haumaier Ludwig 
Published: January 2006

AbstractCattle dung contributes to hot‐spot inputs of nutrients to grassland systems, but not much is known about its organic P (Po) composition and fate in the grassland soils. We used 31Phosphorus (P)–Nuclear Magnetic–Resonance (NMR) spectroscopy of alkaline soil extracts to examine potentials for tracing of different functional Po forms into a temperate grassland soil amended with dung. The proportion of monoester, DNA‐diester, and phospholipid+teichoic acid P were comparable in dung extracts, but the soil was dominated by monoester P. The temporal trends in the DNA‐diester P–to–monoester P (DDNAM) and diester P–to–monoester P (DM) ratio of dung, native soil, and soil amended with dung were monitored in the 70 d field experiment. The DDNAM and DM ratio in the dung‐amended soil (0–1 and 1–5 cm depth) were always intermediate between the dung and (unamended) control soil. Clearly, extracted soil P was a mixture of incorporated dung‐derived P and native soil P. The dung‐P contribution in the 0–1 cm samples peaked at 47% of the total extracted P at day 70 and at 15% after 42 d in the 1–5 cm soil depth (based on the DM ratio). The proportions of dung‐derived P and C in the soil were positively correlated with: 1) topsoil, using the DDNAM ratio (r2 = 0.975), and 2) top‐ and subsoil, using the DM ratio (r2 = 0.656). We concluded that our DDNAM and DM‐P ratios approach (obtained from solution‐31P NMR) did trace successfully the short‐term dynamics and fate of dung Po in soil. It indicated that dung‐derived Po varied as rapidly in soil as the dung‐derived C.
Mitochondrial organization in prepubertal goat oocytes during in vitro maturation and fertilization
Authors: Velilla Esther , RodrÍguez‐Gonzalez Elisabet , Vidal Francesca , Izquierdo Dolors , Paramio Maria‐Teresa 
Published: January 2006

AbstractThe aim of this study was to evaluate mitochondrial distribution during in vitro maturation (at 0, 15, 20, and 27 hr of IVM) and fertilization of prepubertal goat oocytes compared to mitochondrial distribution of ovulated and in vitro fertilized oocytes from adult goats. Oocytes from prepubertal goats were recovered from a slaughterhouse and were matured in M199 with hormones and serum for 27 hr. Ovulated oocytes were collected from gonadotrophin‐treated Murciana goats. Frozen‐thawed spermatozoa were selected by centrifugation in Percoll gradient and were capacitated in DMH with 20% steer serum for 1 hr. Ovulated and IVM‐oocytes were inseminated in DMH medium with steer serum and calcium lactate for 20 hr. Oocytes and presumptive zygotes were stained with Mitotraker Green FM and observed under a confocal laser scanning microscope. Ultrastructural morphology of oocytes and presumptive zygotes were analyzed by transmission electron microscopy (TEM). Prepubertal goat oocytes at germinal vesicle stage (GV) presented mitochondria localized in the cortical and perinuclear region. IVM‐oocytes at metaphase II presented mitochondria peripheral polarized to the region opposite were the metaphase spindle is positioned and within the polar body. Ovulated oocytes presented peripheral mitochondria distribution and mitochondrial aggregation around the MII spindle. At 20 hr post‐insemination, mitochondria were distributed around the two synchronous pronuclei (2PN rpar; in zygotes ovulated oocytes whereas in prepubertal 2PN‐zygotes mitochondria presented a peripheral polarized distribution. Images by TEM detected that immature prepubertal goat oocytes that are less electrodense and present fewer cristae than in vitro matured prepubertal goat oocytes; these are characterized by being associated to swollen vesicles. Mol. Reprod. Dev. 73: 617–626, 2006 © 2006 Wiley‐Liss, Inc.
Multinuclear NMR and MRI studies of the maturation of pig articular cartilage
Authors: Keinan‐Adamsky Keren , Shinar Hadassah , Navon Gil 
Published: January 2006

AbstractThe maturation of pig articular cartilage was followed by 2H in‐phase double quantum filtered (IP‐DQF) spectroscopic MRI, 1H T2 MRI, and 23Na DQF and triple quantum filtered MRS. The results all lead to the conclusion that the order and density of the collagen fibers in articular cartilage increase from birth to maturity. At birth, both 2H IP‐DQF signal and 1H T2 were homogeneous throughout the cartilage and their values independent of the orientation of the plug relative to the magnetic field. At maturation, the 2H IP‐DQF spectrum near the bone is composed of two pairs of quadrupolar split satellites and the 1H T2 relaxation is biexponential, indicating the presence of two groups of collagen fibers. The 2H satellites are orientation dependent, indicating that the two groups of fibers are well ordered at maturation. The fast component of 1H T2 is also orientation dependent and thus we have concluded that this component results from residual dipolar interaction, while the slow T2 component in mature cartilage, as well as the T2 relaxation in immature cartilage, is governed by other mechanisms. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Echoplanar diffusion tensor imaging of the lower leg musculature using eddy current nulled stimulated echo preparation
Authors: Steidle G. , Schick F. 
Published: January 2006

AbstractA sequence for echoplanar diffusion tensor imaging of musculature was developed using a stimulated echo preparation. The strategy was optimized in order to obtain reliable diffusion tensor data in a short measuring time. Image distortion problems due to eddy currents arising from long‐lasting diffusion sensitizing gradients could be overcome by insertion of additional gradient pulses in the TM interval of the stimulated echo preparation. In contrast to former approaches with similar intention, the proposed strategy does not influence the stimulated echo signal itself and does not lead to prolonged echo time as in the case of spin echo methods. Phantom measurements were performed to compare eddy current induced distortion effects in diffusion weighted images. The diffusion tensor in the musculature of the lower leg was investigated in four healthy subjects and maps of the trace and the three eigenvalues of the diffusion tensor, fractional anisotropy maps, and angle maps were calculated. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Design and analysis of a practical 3D cones trajectory
Authors: Gurney Paul T. , Hargreaves Brian A. , Nishimura Dwight G. 
Published: January 2006

AbstractThe 3D Cones k‐space trajectory has many desirable properties for rapid and ultra‐short echo time magnetic resonance imaging. An algorithm is presented that generates the 3D Cones gradient waveforms given a desired field of view and resolution. The algorithm enables a favorable trade‐off between increases in readout time and decreases in the total number of required readouts. The resulting trajectory is very signal‐to‐noise ratio (SNR) efficient and has excellent aliasing properties. A rapid high‐resolution ultra‐short echo time imaging sequence is used to compare the 3D Cones trajectory to 3D projection reconstruction (3DPR) sampling schemes. For equivalent scan times, the 3D Cones trajectory has better SNR performance and fewer aliasing artifacts as compared to the 3DPR trajectory. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Dynamics of electrically charged transient evaporating sprays
Authors: Shrimpton John S. , Laoonual Yossapong 
Published: January 2006

AbstractThe evolution of an evaporating spray plume typical of those under consideration for use in direct injection spark ignition (DISI) engines, for early and late fuel injection strategies is investigated. Here the effect of electric charge, present on individual drops, upon the spray dispersal and evaporation rate is investigated with the aim of optimizing these parameters with respect to typical engine timescales and injection strategy. The predictions suggest that applying electric charge to drops in sprays injected early into the intake stroke does not have a beneficial effect. The spray evaporation rate is not significantly enhanced, and the long time interval between fuel injection and ignition actually promotes spray wall deposition. Conversely, applying electric charge to sprays injected late encourages secondary atomization and the increase in surface area greatly improves the evaporation rate. This is also true at higher engine speeds, corresponding to a much reduced time between fuel injection and ignition. Therefore it is suggested that the selective use of electric charge is viable way of tuning the spray character without effecting fuel metering when moving from an early to a late injection strategy in DISI engines when variable loads are required. Copyright © 2006 John Wiley & Sons, Ltd.
Thermal stability and degradation kinetics of poly(methyl methacrylate)/layered copper hydroxy methacrylate composites
Authors: Kandare Everson , Deng Hongmei , Wang Dongyan , Hossenlopp Jeanne M. 
Published: January 2006

AbstractPoly(methyl methacrylate) (PMMA)/copper hydroxy methacrylate (CHM) composites were prepared via solution blending and bulk polymerization. Addition of 3% by weight of the CHM additive using solution blending resulted in a significant increment (∼45°C) in thermogravimetric analysis (TGA) T50, the temperature at which 50% of the original polymeric mass is lost. The value T50 increased by 30°C for a PMMA composite with 4% CHM, synthesized via bulk polymerization. Activation energies, Ea, were calculated as a function of conversion fractions (TGA decomposition profile) for the polymeric materials. Analysis of multiple heating rate data using the Flynn–Wall–Ozawa method resulted in Ea values that were 50 kJ mol−1 higher for conversions above 0.5 in the solution blended composite compared to a reference sample of pure PMMA recrystallized from the same solvent. Similar results were obtained for bulk polymerization process with differences in Ea values > 30 kJ mol−1 relative to pure PMMA. However, in contrast to previous studies of bulk polymerized samples, the solution‐blended composite exhibited no improvement in cone calorimetry determination of total heat release as compared with the reference PMMA sample. Copyright © 2006 John Wiley & Sons, Ltd.
De novo monosomy 9p24.3‐pter and trisomy 17q24.3‐qter characterised by microarray comparative genomic hybridisation in a fetus with an increased nuchal translucency
Authors: Brisset Sophie , Kasakyan Serdar , L'Herminé Aurore Coulomb , Mairovitz Valérie , Gautier Evelyne , Aubry Marie‐Cécile , Benkhalifa Moncef , Tachdjian Gérard 
Published: January 2006

AbstractObjectivesIncreased nuchal translucency (NT) during the first trimester of pregnancy is a useful marker to detect chromosomal abnormalities. Here, we report a prenatal case with molecular cytogenetic characterisation of an abnormal derivative chromosome 9 identified through NT.MethodsAmniocentesis was performed because of an increased NT (4.4 mm) and showed an abnormal de novo 46,XX,add(9)(p24.3) karyotype. To characterise the origin of the small additional material on 9p, we performed a microarray comparative genomic hybridisation (microarray CGH) using a genomic DNA array providing an average of 1 Mb resolution.ResultsMicroarray CGH showed a deletion of distal 9p and a trisomy of distal 17q. These results were confirmed by FISH analyses. Microarray CGH provided accurate information on the breakpoint regions and the size of both distal 9p deletion and distal 17q trisomy. The fetus was therefore a carrier of a de novo derivative chromosome 9 arising from a t(9;17)(p24.3;q24.3) translocation and generating a monosomy 9p24.3‐pter and a trisomy 17q24.3‐qter.ConclusionThis case illustrates that microarray CGH is a rapid, powerful and sensitive technology to identify small de novo unbalanced chromosomal abnormalities and can be applied in prenatal diagnosis. Copyright © 2006 John Wiley & Sons, Ltd.
Nuchal translucency measurements are highly correlated in both mono‐ and dichorionic twin pairs
Authors: Wøjdemann Karen R. , Larsen Severin Olesen , Shalmi Anne‐Cathrine , Sundberg Karin , Tabor Ann , Christiansen Michael 
Published: January 2006

AbstractObjectivesTo establish the distribution of serological and ultrasound first‐trimester Down syndrome markers in twins and identify correlations of significance for risk calculation.MethodsNuchal translucency (NT), PAPP‐A and βhCG data were extracted from 181 twin pregnancies (31 mono‐ and 150 dichorionic) with a normal outcome. All pregnancies were consecutively and prospectively included and examined in the Copenhagen First‐Trimester Study. The variance of the sum and the difference of log MoM NT values in twin pairs was used to calculate the correlation.ResultsThe serological markers did not correlate and were nearly twice the value seen in singleton pregnancies with a median PAPP‐A MoM of 2.14 and a median free βhCG MoM of 2.06. Chorionicity was not found to influence the level of biochemical markers. In all twin pairs (r = 0.343, p < 0.001, F‐test), as well as mono‐ (r = 0.404, p = 0.011, F‐test) and dichorionic twins (r = 0.316, p < 0.001, F‐test) there was a significant correlation between log MoM NT in each pair.ConclusionAs the NT values of fetuses in subsequent pregnancies from the same woman do not correlate, the correlation between NTs in twins reflects that the NT is influenced by placental and maternal factors specific for the particular pregnancy, for example, nutrient supply or vascularisation. The correlation may be useful to improve the precision of the prenatal risk assessment for Down syndrome in first‐trimester twin pregnancies. The serological markers were elevated in the examined twins as previously described. Copyright © 2006 John Wiley & Sons, Ltd.
The OEIS complex: two case reports that illustrate the spectrum of abnormalities and a review of the literature
Authors: Vasudevan Pradeep C. , Cohen Marta C. , Whitby Elspeth H. , Anumba Dilly O. C. , Quarrell Oliver W. J. 
Published: January 2006

AbstractWe present two cases of OEIS (omphalocele, exstrophy, imperforate anus, spinal defects) complex ‐MIM 258040 and a review of the literature. Case 1 was a 14‐year‐old girl who presented at 30 weeks' gestation. An ultrasound examination showed an omphalocele and spina bifida; the bladder was not visualised. She went into spontaneous labour two weeks later and the baby died shortly after birth. A full post‐mortem examination was refused, but the mother did agree to an external examination, skin biopsy for fibroblast culture, X rays and MR imaging. The MR imaging showed a pelvic kidney, a large omphalocele containing the other kidney, liver, bowel and a fluid filled structure thought to represent an exstrophy of the bladder (EB). Case 2 was a 30‐year‐old woman who had an ultrasound examination at 20 weeks' gestation; this showed an omphalocele, but the bladder was not visualised. The pregnancy was subsequently terminated and a post‐mortem examination showed a low set umbilical cord associated with a small omphalocele; there was an imperforate anus; a blind ending rectum terminated in the omphalocele. We conclude that these two cases illustrate the variability of the OEIS complex. Copyright © 2006 John Wiley & Sons, Ltd.