bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil properties affecting the toxicity of CuCl2 and NiCl2 for soil microbial processes in freshly spiked soils
Authors: Oorts Koen , Ghesquiere Uldeen , Swinnen Koen , Smolders Erik 
Published: February 2006

AbstractIt generally is unknown to what extent the toxicity of Cu and Ni for soil microbial processes varies among different soils. A comparative study was made using three different microbial assays (nitrification potential, glucose-induced respiration, and C-mineralization of a plant residue) in 19 (for Cu) or 16 (for Ni) soils with contrasting soil properties. Each soil was spiked with CuCl2 or NiCl2 at seven different concentrations, and the bioassays were started after a 7-d equilibration period. The Cu and Ni toxicity thresholds varied 19- to 90-fold among soils. The differences in both Cu and Ni toxicity among soils were neither explained by soil solution metal concentrations nor by free ion activities calculated from soil solution composition. Copper toxicity thresholds (total concentrations) increased with increasing organic matter content or cation exchange capacity (CEC) and, surprisingly, decreased with increasing pH depending on the assay. Nickel toxicity thresholds consistently increased with increasing CEC, background Ni, and clay content for all three assays. Thresholds expressed as soil solution free ion activities all significantly decreased with increasing soil solution pH (r2 = 0.57–0.93), consistent with a decreased H+:M2+ competition at the biological membrane. That competition largely counteracts the H+:M2+ competition for sorption, effectively explaining the insignificant or weak effect of pH on total Ni or Cu toxicity thresholds. It is concluded that free metal-ion activity alone does not explain variation in metal toxicity among soils.
Transfer of Cd, Cu, Ni, Pb, and Zn in a soil-plant-invertebrate food chain: A microcosm study
Authors: Scheifler Renaud , de Vaufleury Annette , Cœurdassier Michaël , Crini Nadia , Badot Pierre-Marie 
Published: February 2006

Abstract
The transfer of Cd, Cu, Ni, Pb, and Zn was evaluated in a soil-plant (lettuce, Lactuca sativa)–invertebrate (snail, Helix aspersa) food chain during a microcosm experiment. Two agricultural soils, polluted and unpolluted, were studied. Lettuce was cultivated for eight weeks before introduction of snails into the microcosms (M-snails). In a parallel experiment, snails were exposed to lettuce only (i.e., without soil) in simpler exposure devices called containers (C-snails). Snail exposure duration was eight weeks for both M- and C-snails. No effects on snail survival were found. Both M- and C-snails exposed to polluted soil showed a growth reduction, but only after two weeks of exposure. Time-dependent accumulation in M-snails exposed to the polluted environment showed a regular increase of Cd and Zn concentrations over time and a rapid increase of Pb concentrations within the first two weeks, which then remained stable. Copper and Ni concentrations did not increase during any of the experiments. Concentrations in M- and C-snails were compared to estimate the relative contribution of soil and plant to the total bioaccumulation. The results suggest that the soil contribution may be higher than 80% for Pb, from 30 to 60% for Zn, and from 2 to 40% for Cd.
Effect of pH on metal speciation and resulting metal uptake and toxicity for earthworms
Authors: Spurgeon David J. , Lofts Stephen , Hankard Peter K. , Toal Mark , McLellan Donna , Fishwick Samantha , Svendsen Claus 
Published: February 2006

AbstractIn the present study, relationships between changes in the solubility and speciation of metals in contaminated soils under different pH regimes and their toxicity to earthworms were investigated. Earthworms (Lumbricus rubellus) were exposed in a laboratory bioassay to metalliferous soils under three pH regimes: Unamended pH, pH lowered by one unit (pH — 1), and pH increased by one unit (pH +1). In each soil, total (hot nitric acid-extractable) and 0.01 M CaCl2–extractable metal concentrations were measured and soil pore-water chemistry analyzed to allow metal speciation to be modeled using the Windermere Humic Aqueous Model. Earthworm metal accumulation was determined and toxicity assessed by measuring survival and reproduction and at the molecular level by recording expression of the gene encoding metallothionein-2 (MT-2) using quantitative reverse transcriptase-polymerase chain reaction. Both metal solubility and speciation were found to be highly pH dependent. Metal accumulation in earthworms was influenced by soil concentration and, in some cases (e.g., Cd), by pH. Reproduction was affected (reduced up to 90%) by soil metal level, pH, and their interaction. Relationships between analyzed and calculated Zn concentrations and toxicity and between analyzed and calculated Cd concentrations and tissue accumulation and MT-2 expression were compared by fitting dose-response models and assessing the fit of the data. This analysis indicated that values based on a pH-adjusted free ion concentration best explained toxicity (r2 = 0.82) and accumulation (r2 = 0.54). Expression of MT-2 was, however, poorly correlated (p &gt; 0.05) with all analyzed and modeled soil metal concentrations.
Kinetics of metal fixation in soils: Measurement and modeling by isotopic dilution
Authors: Crout Neil M. J. , Tye Andy M. , Zhang Hao , McGrath Steve P. , Young Scott D. 
Published: February 2006

Abstract
The bioavailability of metal contaminants in soils varies widely, depending on soil characteristics and the source of the contaminant. As a consequence, site-specific risk assessment requires accurate prediction of the bioavailable (or labile) fraction of soil metal. Moreover, metals in soil are subject to time-dependent processes, which affect their bioavailability and thereby complicate the prediction of future risk. The aim of the present study was to describe the development of simple, readily applicable models for the time-dependent changes in lability of Cd and Zn in soils. We present data showing the time-dependent behavior of radiolabile and soil solution concentrations of Cd and Zn during an incubation study over a period of 813 d in 23 diverse soils. The data are used to parameterize candidate models of metal fixation in soils designed to be readily applicable and therefore relevant to risk assessment. We conclude that the final extent of metal fixation increases with pH and generally is greater for Zn than for Cd; however, the rate of fixation is independent of pH and equivalent to a half-time to equilibrium of 29 and 89 d for Cd and Zn, respectively. It is possible that longer-term processes occur, especially for Zn, but these could not be detected in the present study.
Biological significance of metals partitioned to subcellular fractions within earthworms (Aporrectodea caliginosa)
Authors: Vijver Martina G. , van Gestel Cornelis A. M. , van Straalen Nico M. , Lanno Roman P. , Peijnenburg Willie J. G. M. 
Published: February 2006

Abstract
Metal ions in excess of metabolic requirements are potentially toxic and must be removed from the vicinity of important biological molecules to protect organisms from adverse effects. Correspondingly, metals are sequestrated in various forms, defining the accumulation pattern and the magnitude of steady-state levels reached. To investigate the subcellular fractions over which Ca, Mg, Fe, Cu, Zn, Cd, Pb, Ni, and As are distributed, earthworms (Aporrectodea caliginosa) collected from the field were analyzed by isolating metal-rich granules and tissue fragments from intracellular microsomal and cytosolic fractions (i.e., heat-stable proteins and heat-denatured proteins). The fractions showed metal-specific binding capacity. Cadmium was mainly retrieved from the protein fractions. Copper was equally distributed over the protein fraction and the fraction comprising tissue fragments, cell membranes, and intact cells. Zinc, Ca, Mg, and As were mainly found in this fraction as well. Lead, Fe, and Ni were mainly isolated from the granular fraction. To study accumulation kinetics in the different fractions, three experiments were conducted in which earthworms were exposed to metal-spiked soil and a soil contaminated by anthropogenic inputs and, indigenous earthworms were exposed to field soils. Although kinetics showed variation, linear uptake and steady-state types of accumulation patterns could be understood according to subcellular compartmentalization. For risk assessment purposes, subcellular distribution of metals might allow for a more precise estimate of effects than total body burden. Identification of subcellular partitioning appears useful in determining the biological significance of steady-state levels reached in animals.
Synthesis and Potent Antimicrobial Activities of Some Novel Retinoidal Monocationic Benzimidazoles
Authors: Ates‐Alagöz Zeynep , Alp Mehmet , Kus Canan , Yildiz Sulhiye , Buyukbingöl Erdem , Göker Hakan 
Published: February 2006

AbstractSeveral 2‐(5,5,8,8‐tetramethyl‐5,6,7,8‐tetrahydronaphthalen‐2‐yl)‐1H‐benzimidazole‐5‐carboxamidine analogues were synthesized for their antibacterial and antifungal activities against S. aureus, Methicillin‐resistant S. aureus (MRSA), C. albicans, and C. krusei. MIC values of the targeted compounds 43‐58 are comparable to those of Fluconazole and Sultamicillin. The most potent compounds, 51 and 53, showed MIC values as 0.78 and 1.56 μg/mL against S. aureus and C. albicans, respectively.
Synthesis and Characterization of Thiol Containing Furoxan Derivatives as Coligands for the Preparation of Potential Bioreductive Radiopharmaceuticals
Authors: Cerecetto Hugo , González Mercedes , Onetto Silvia , Risso Mariela , Rey Ana , Giglio Javier , León Elsa , León Alba , Pilatti Pierina , Fernández Marcelo 
Published: February 2006

AbstractThe synthesis and characterization of thiol‐containing 1,2,5‐oxadiazole N‐oxide (TONO) derivatives and their use as monodentate coligands for the preparation of 99mTc complexes is presented. 3‐Mercaptomethyl‐4‐phenyl‐1,2,5‐oxadiazol N2‐oxide and 3‐(4‐mercaptophenylmethylidenhydrazinocarbonyloxymethyl)‐4‐phenyl‐1,2,5‐oxadiazol N2‐oxide were successfully synthesized and combined with the tridentate ligand N,N‐bis(2‐mercaptoethyl)‐N′,N′‐diethylethylenediamine (BMEDA) to prepare “3+1 mixed ligand” technetium complexes. The 99mTc complexes were obtained in high yield and radiochemical purity using low concentration of ligand and coligand. An alternative procedure using a xantate and a disulphide precursor of 3‐mercaptomethyl‐4‐phenyl‐1,2,5‐oxadiazol N2‐oxide yielded the same complex. Biological evaluation of the potentiality of the 99mTc complexes as bioreductive radiopharmaceuticals was performed in normal CD1 mice and in mice bearing induced sarcoma. Tumour uptake was moderate but tumour/soft tissue ratio was favourable. Although these results are encouraging, further development is still necessary in order to achieve higher tumour uptake and lower gastrointestinal activity.
Synthesis and Biological Evaluation of Some Hydroxypyrazole Derivatives as Anti‐inflammatory‐Antimicrobial Agents
Authors: Bekhit Adnan A. , Abdel‐Rahman Hamdy M. , Guemei Aida A. 
Published: February 2006

AbstractSome hydroxypyrazole derivatives 2–7 were synthesized by cyclocondensation of the keto‐ester 1 with hydrazines hydrate or substituted hydrazines followed by reduction and acylation with acetic anhydride or trifluoroacetic anhydride. The newly synthesized compounds were evaluated for their anti‐inflammatory, antimicrobial activities. In addition, the ulcerogenic and acute toxicity profiles were determined. Compounds N‐(4‐(5‐hydroxy‐1‐trifluoroacetyl‐1H‐pyrazol‐3‐yl)phenyl) trifluoroacetamide 4b, 3‐(4‐nitrophenyl)‐1‐(4‐methoxyphenyl)‐1H‐pyrazol‐5‐ol 5b, and N‐(4‐(5‐hydroxy‐1‐methyl‐1H‐pyrazol‐3‐yl)phenyl)trifluoroacetamide 7b were proved to be the most active anti‐inflammatory, antimicrobial agents in the present study with a good safety margin and minimal or no ulcerogenic effect.
Planung für das Schiffshebewerk am Drei‐Schluchten‐Staudamm in China
Authors: Krebs Dorothea , Runte Thomas , Strack Gerhard 
Published: February 2006

AbstractZur Beförderung von Passagierschiffen am Drei‐Schluchten‐Staudamm am Yangtze ist in der Nähe der Stadt Yichang ein Senkrecht‐Schiffshebewerk nach dem Gegengewichtsprinzip vorgesehen, das derzeit durch die China Yangtze Three Gorges Project Corporation, Bauherr und Betreiber des Drei‐Schluchten‐Staudamms, geplant wird. Mit der Ausschreibungsplanung ist die “German Design Group”, ein deutsches Joint Venture, bestehend aus Krebs und Kiefer International und Lahmeyer International, beauftragt. Berater des Bauherrn im Sinne eines “Panel of Experts” ist die Bundesanstalt für Wasserbau.
Der Viadukt über das Tarntal bei Millau – Von den ersten Entwurfsgedanken bis zur Fertigstellung
Authors: Virlogeux Michel 
Published: February 2006

AbstractDer Bau des Viadukts über das Tarntal bei Millau in Mittelfrankreich begann im Oktober 2001 und war im Dezember 2004 vollendet. Der Viadukt mit einer Gesamtlänge von 2460 m umfaßt sechs 342 m lange Hauptfelder, die an sieben Pylonen verankert sind und stellt einen bedeutenden Fortschritt im Entwurf von Schrägseilbrücken dar. Die Autobahn verläuft 270 m über dem Fluß, zwei ihrer Pfeiler sind höher als 230 m. Mit den 87 m hohen Pylonen über der Fahrbahn überragen sie den Eiffelturm. Ausgearbeitet wurden zwei Lösungen, eine in Spannbeton und eine in Stahlbauweise.
Kriechen von Ultrahochfestem Beton (UHFB)
Authors: Tue Nguyen , Ma Jianxin , Orgass Marko 
Published: February 2006

AbstractDer Aufsatz behandelt das Kriechverhalten von ultrahochfestem Beton (UHFB) mit einer Druckfestigkeit von 150 N/mm2 und höher. Durch Variation der Beanspruchungen im Bereich zwischen 28% und 85% der Betonfestigkeit zum Belastungszeitpunkt konnte der Übergang vom linearen zum nichtlinearen Kriechen ermittelt werden. Ein Vergleich der Versuchergebnisse mit dem Ansatz der neuen DIN 1045‐1 verdeutlicht die Notwendigkeit weiterer Untersuchungen des Kriechverhaltens von UHFB, insbesondere bei Belastung im jungen Betonalter und bezüglich der zeitlichen Entwicklung des Kriechens.
Zum Tragverhalten von Mauerwerksbauten unter Erdbebenbelastung
Authors: Ötes Atilla , Löring Stephan 
Published: February 2006

AbstractDas Bemessungsziel bei der Erdbebenauslegung eines Bauwerks ist das Sicherstellen einer ausreichenden Tragfähigkeit unter Berücksichtigung der Duktilität der Konstruktion. Mit experimentellen Untersuchungen an geschoßhohen Wänden wurde an der Universität Dortmund das Widerstands‐ und Verformungsverhalten von aussteifenden Mauerwerkswänden unter simulierten Erdbebenbelastungen bis zum Versagen identifiziert. Das nichtlineare Tragverhalten der Wände wurde in bezug auf Tragfähigkeit und Duktilitätspotential ausgewertet. In Abhängigkeit der Art des erreichten Grenzzustands zeigten die Mauerwerkswände unterschiedliche Werte für Duktilität. Mit rechnerischen Betrachtungen konnte gezeigt werden, daß innerhalb bestimmter Grenzen durch die Abstimmung der Konstruktionsparameter duktile Grenzmechanismen erreicht werden können. Ausgehend von repräsentativen Konfigurationen für aussteifende Wände wurden für Reihen‐ und Mehrfamilienhäuser die Tragwerksduktilität und der damit korrespondierende Verhaltensbeiwert für den Erdbebennachweis (vgl. EC 8 und DIN 4149) abgeschätzt.
Johann August Röbling (1806–1869) – Vom preußischen Bauconducteur zum amerikanischen Brückenbauer und Industriellen
Authors: Patzschke Fritz 
Published: February 2006

AbstractAnläßlich der 200. Wiederkehr seines Geburtstages wird an das Wirken und Werden des deutschstämmigen Amerikaners und Absolventen der preußischen Bauakademie, Johann August Röbling aus Mühlhausen in Thüringen, erinnert. Mit dem Wissen des alten Europa hat er großartige Brücken und ein industrielles Imperium, die Drahtseilproduktion, im Amerika des 19. Jahrhunderts geschaffen.
Separation of catechin compounds from different teas
Authors: Jin Yinzhe , Jin Chun Hua , Ho Row Kyung 
Published: February 2006

AbstractCatechin compounds from Korean and Chinese green tea, and pu‐erh, Indian black, Longjing, Tieguanyin, Bamboo, Jasmine, Oolong, Flower, Red teas, as potential anticancer and antioxidant components, were target material in this work. After extracting the green tea with water at 50°C for 4 h, the extract was partitioned with water/chloroform, which was best suited to remove caffeine impurity from the extract. Further, the resulting extract was partitioned with water/ethyl acetate to deeply purify the five catechin compounds epigallocatechin, (+) catechin, epicatechin, epigallocatechin gallate and epicatechin gallate. The extracted samples were analyzed by reversed‐phase high performance liquid chromatography. The mobile phase applied was the binary system of A (water/acetic acid, 100/0.1 vol%) and B (acetonitrile/acetic acid 100/0.1 vol%) from 90:10 to 70:30 (A:B vol%) in a linear gradient over 30 min time. The amount of catechin compounds extracted from Chinese green tea was 114.65% higher than from the Korean green tea. Comparing various tea sorts, the green teas contained more than 1.7 times of the five catechin compounds contained in other teas.
Cancer immunotherapy
Authors: Schuster Manfred , Nechansky Andreas , Kircheis Ralf 
Published: February 2006

AbstractCancer is the second leading cause of death in the industrialized world. Most cancer patients are treated by a combination of surgery, radiation and/or chemotherapy. Whereas the primary tumor can, in most cases, be efficiently treated by a combination of these standard therapies, preventing the metastatic spread of the disease through disseminated tumor cells is often not effective. The eradication of disseminated tumor cells present in the blood circulation and micro‐metastases in distant organs therefore represents another promising approach in cancer immunotherapy. Main strategies of cancer immunotherapy aim at exploiting the therapeutic potential of tumor‐specific antibodies and cellular immune effector mechanisms. Whereas passive antibody therapy relies on the repeated application of large quantities of tumor antigen‐specific antibodies, active immunotherapy aims at the generation of a tumor‐specific immune response combining both humoral and cytotoxic T cell effector mechanisms by the host's immune system following vaccination. In the first part of this review, concurrent developments in active and passive cancer immunotherapy are discussed. In the second part, the various approaches for the production of optimized monoclonal antibodies used for anti‐cancer vaccination are summarized.
Effect of Vitreoscilla hemoglobin on production of a chemotherapeutic enzyme, L‐asparaginase, by Pseudomonas aeruginosa
Authors: Geckil Hikmet , Gencer Salih , Ates Burhan , Ozer Ufuk , Uckun Mirac , Yilmaz Ismet 
Published: February 2006

AbstractThe production of L‐asparaginase, an enzyme widely used in cancer chemotherapy, is mainly regulated by carbon catabolite repression and oxygen. This study was carried out to understand how different carbon sources and Vitreoscilla hemoglobin (VHb) affect the production of this enzyme in Pseudomonas aeruginosa and its VHb‐expressing recombinant strain (PaJC). Both strains grown with various carbon sources showed a distinct profile of the enzyme activity. Compared to no carbohydrate supplemented medium, glucose caused a slight repression of L‐asparaginase in P. aeruginosa, while it stimulated it in the PaJC strain. Glucose, regarded as one of the inhibitory sugars for the production L‐asparaginase by other bacteria, was determined to be the favorite carbon source compared to lactose, glycerol and mannitol. Furthermore, contrary to common knowledge of oxygen repression of L‐asparaginase in other bacteria, oxygen uptake provided by VHb was determined to even stimulate the L‐asparaginase synthesis by P. aeruginosa. This study, for the first time, shows that in P. aeruginosa utilizing a recombinant oxygen uptake system, VHb, L‐asparaginase synthesis is stimulated by glucose and other carbohydrate sources compared to the host strain. It is concluded that carbon catabolite and oxygen repression of L‐asparaginase in fermentative bacteria is not the case for a respiratory non‐fermentative bacterium like P. aeruginosa.
Manufacturing of recombinant therapeutic proteins in microbial systems
Authors: Graumann Klaus , Premstaller Andreas 
Published: February 2006

AbstractRecombinant therapeutic proteins have gained enormous importance for clinical applications. The first recombinant products have been produced in E. coli more than 20 years ago. Although with the advent of antibody‐based therapeutics mammalian expression systems have experienced a major boost, microbial expression systems continue to be widely used in industry. Their intrinsic advantages, such as rapid growth, high yields and ease of manipulation, make them the premier choice for expression of non‐glycosylated peptides and proteins. Innovative product classes such as antibody fragments or alternative binding molecules will further expand the use of microbial systems. Even more, novel, engineered production hosts and integrated technology platforms hold enormous potential for future applications. This review summarizes current applications and trends for development, production and analytical characterization of recombinant therapeutic proteins in microbial systems.
Molecular Structures and Magnetism of Mn12 Nanomagnets Containing the 3‐Thiophenecarboxylate Ligand (Eur. J. Inorg. Chem. 4/2006)
Authors: Lim Jin Mook , Do Youngkyu , Kim Jinkwon 
Published: February 2006

AbstractThe cover picture shows the Mn12 single‐molecule magnet (SMM), which has a 3‐thiophenecarboxylate ligand and is formed by the ligand substitution reaction of Mn12‐ac with 16 equiv. of 3‐thiophenecarboxylic acid in toluene. The reaction of Mn12‐ac with 17 equiv. of 3‐thiophenecarboxylic acid affords a different Mn12 SMM that shows a more distorted structure and has a faster relaxation rate. The Mn12 SMM is strongly anchored on the gold surface through the sulfur atoms of the thiophenyl group. The Mn12 molecular film on Au(111) was characterized by XPS, STM, and AFM. Further details are discussed in the article by J. Kim et al. on p. 711 ff.
Hydrodynamic flow and electroosmotic flow in zirconia‐packed capillaries
Authors: Crosnier de Bellaistre Myriam , Randon Jérôme , Rocca Jean‐Louis 
Published: February 2006

AbstractFused‐silica capillaries were packed with Zirchrom®‐PBD stationary phase for application in CEC, nanoLC and pseudoelectrochromatography (PEC). Acido‐basic properties of zirconia can be used to control the EOF even if the zirconia particles were coated by polybutadiene. As for native zirconia, the EOF is pH‐dependent and the pI is close to pH 5. The mixed‐mode pressure–voltage technique induced a modulation of the mobile‐phase velocity as well as an electrophoretic migration of the solutes in order to improve the resolution of the separation. A significant increase of the flow appeared when both hydrodynamic and EOFs were in the same direction. But an important reduction of the electroosmotic velocity was observed when the hydrodynamic flow and EOF were opposed in Zirchrom‐PBD columns. This behaviour has been observed at high or low pH on several columns. Separations of neutral and charged compounds have been performed with these columns in PEC mode.