bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐term after‐effects of fertilisation on the restoration of calcareous grasslands
Authors: Smits N.A.C. , Willems J.H. , Bobbink R. 
Published: February 2008

Question: What are the long‐term implications of former fertilisation for the ecological restoration of calcareous grasslands?Location: Gerendal, Limburg, The Netherlands.Methods: In 1970, ten permanent plots were established in just abandoned agricultural calcareous grassland under a regime of annual mowing in August. From 1971 to 1979, two different fertiliser treatments were applied twice a year to a subset of the plots (artificial fertiliser with different proportions of nitrogen and phosphorus). The vegetation of the plots was recorded yearly and vegetation biomass samples were taken for peak standing crop and total amounts of nitrogen, phosphorus and potassium. Species composition and floristic diversity were analysed over the research period (1970–2006) and between the treatments, including the use of multivariate techniques (Detrended Correspondence Analysis).Results: In terms of species number, there is a clear optimum 10 to 20 years after fertilisation has been terminated. Afterwards, there is a slow decrease; no new species appear and species of more nutrient‐rich conditions gradually disappear. For the fertilised plots that received a relatively high proportion of N, effects are found only in the first years, whereas, for the plots that received a relatively high proportion of P, long‐term after‐effects are found in species composition, peak standing crop, total amounts of phosphorus in biomass, and in soil phosphorus data.Conclusions: The effect of artificial fertiliser with a large amount of nitrogen disappears in less than ten years when mown in August, including removal of the hay. This is a promising result for restoration of N‐enriched calcareous grasslands, as the applied dose of nitrogen in this experiment largely exceeds the extra input of nitrogen via atmospheric deposition. Application of fertiliser with a large amount of phosphorus, however, has effects even more than 25 years after the last addition. There are no prospects that this effect will become reduced in the near future under the current mowing management.
A Finite Element Formulation for Atrial Tissue Monolayer
Authors: Richter H. E. , Plank G. , Pfeifer B. , Tilg B. , Nowak C. N. , Fischer G. , Wieser L. 
Published: February 2008

Summary

Objectives:
Using computer models for the study of complex atrial arrhythmias such as atrial fibrillation is computationally demanding as long observation periods in the order of tens of seconds are required. A well established approach for reducing computational workload is to approximate the thin atrial walls by curved monolayers. On the other hand, the finite element method (FEM) is a well established approach to solve the underlying partial differential equations.

Methods:
A generalized 2D finite element method (FEM) is presented which computes the corresponding stiffness and coupling matrix for arbitrarily shaped monolayers (ML). Compared to standard 2D FEM, only one additional coordinate transformation is required. This allows the use of existing FEM software with minor modifications. The algorithm was tested to simulate wave propagation in benchmark geometries and in a model of atrial anatomy.

Results:
The ML model was able to simulate electric activation in curved tissue with anisotropic conductivity. Simulations in branching tissue yielded slightly different patterns when compared to a volumetric model with finite thickness. In the model of atrial anatomy the computed activation times for five different pacing protocols displayed a correlation of 0.88 compared to clinical data.

Conclusions:
The presented method provides a useful and easily implemented approach to model wave propagation in MLs with a few restrictions to volumetric models.
Estimating Morbidity Ratesfrom Electronic Medical Records in General Practice
Authors: Verheij R. A. , de Bakker D. H. , Zielhuis G. A. , de Vries Robbé P. F. , Biermans M. C. J. 
Published: February 2008

Summary

Objectives:
In this study, we evaluated the internal validity of EPICON, an application for grouping ICPCcoded diagnoses from electronic medical records into episodes of care. These episodes are used to estimate morbidity rates in general practice.

Methods:
Morbidity rates based on EPICON were compared to a gold standard; i.e. the rates from the second Dutch National Survey of General Practice. We calculated the deviation from the gold standard for 677 prevalence and 681 incidence rates, based on the full dataset. Additionally, we examined the effect of casebased reasoning within EPICON using a comparison to a simple, not case-based method (EPI-0). Finally, we used a split sample procedure to evaluate the performance of EPICON.

Results:
Morbidity rates that are based on EPICON deviate only slightly from the gold standard and show no systematic bias. The effect of case-based reasoning within EPICON is evident. The addition of case-based reasoning to the grouping system reduced both systematic and random error. Although the morbidity rates that are based on the split sample procedure show no systematic bias, they do deviate more from the gold standard than morbidity rates for the full dataset.

Conclusions:
Results from this study indicate that the internal validity of EPICON is adequate. Assuming that the standard is gold, EPICON provides valid outcomes for this study population. EPICON seems useful for registries in general practice for the purpose of estimating morbidity rates.
Size‐Dependent Catalytic Activity of Supported Palladium Nanoparticles for Aerobic Oxidation of Alcohols
Authors: Chen Jing , Zhang Qinghong , Wang Ye , Wan Huilin 
Published: February 2008

AbstractSilica‐alumina (SiO2‐Al2O3)‐supported palladium catalysts prepared by adsorption of the tetrachloropalladate anion (PdCl42−) followed by calcination and reduction with either hexanol or hydrogen were studied for the aerobic oxidation of alcohols. The mean size of the Pd particles over the SiO2‐Al2O3 support was found to depend on the Si/Al ratio, and a decrease in the Si/Al ratio resulted in a decrease in the mean size of the Pd nanoparticles. By changing the Si/Al ratio, we obtained supported Pd nanoparticles with mean sizes ranging from 2.2 to 10 nm. The interaction between the Pd precursor and the support was proposed to play a key role in tuning the mean size of the Pd nanoparticles. The Pd/SiO2‐Al2O3 catalyst with an appropriate mean size of Pd particles could catalyze the aerobic oxidation of various alcohols to the corresponding carbonyl compounds, and this catalyst was particularly efficient for the solvent‐free conversion of benzyl alcohol. The intrinsic turnover frequency per surface Pd atom depended significantly on the mean size of Pd particles and showed a maximum at a medium mean size (3.6–4.3 nm), revealing that the aerobic oxidation of benzyl alcohol catalyzed by the supported Pd nanoparticles was structure‐sensitive.
Highly Active Polymer‐Supported (Salen)Al Catalysts for the Enantioselective Addition of Cyanide to α,β‐Unsaturated Imides
Authors: Madhavan Nandita , Weck Marcus 
Published: February 2008

AbstractIn this contribution, we describe polymer‐supported (R,R)‐(salen)AlCl complexes that were immobilized on poly(norbornene)s and display excellent activities and enantioselectivies as catalysts for the 1,4‐conjugate addition of cyanide to α,β‐unsaturated imides. These supported catalysts could be recycled up to 5 times without compromising catalyst activities or selectivities. Furthermore, the catalyst loadings could be reduced from 10–15 mol%, the common catalyst loadings for non‐supported (salen)Al catalysts, to 5 mol%, a decrease of metal content by 50–66%, without lowering product yields or enantioselectivities. Kinetic studies indicated that the polymer‐supported catalysts are significantly more active than their corresponding unsupported analogues, which makes this catalyst system key to a successful implementation of this catalytic transformation into the fine chemical and pharmaceutical industries.
A labor theoretic approach to information retrieval
Authors: Warner Julian 
Published: February 2008

AbstractThis article synthesizes the labor theoretic approach to information retrieval. Selection power is taken as the fundamental value for information retrieval and is regarded as produced by selection labor. Selection power remains relatively constant while selection labor modulates across oral, written, and computational modes. A dynamic, stemming principally from the costs of direct human mental labor and effectively compelling the transfer of aspects of human labor to computational technology, is identified. The decision practices of major information system producers are shown to conform with the motivating forces identified in the dynamic. An enhancement of human capacities, from the increased scope of description processes, is revealed. Decision variation and decision considerations are identified. The value of the labor theoretic approach is considered in relation to preexisting theories, real‐world practice, and future possibilities. Finally, the continuing intractability of information retrieval is suggested.
Digital preparedness versus the digital divide: A confusion of means and ends
Authors: James Jeffrey 
Published: February 2008

AbstractComposite indexes of digital preparedness, such as the Networked Readiness Index (NRI) and the Digital Opportunity Index (DOI), have caused a great deal of confusion in the more general literature on the digital divide. For whereas one would expect preparedness to be an input into the utilization of information technologies (the digital divide), the recent indicators add inputs and outputs, or means and ends. I suggest instead two separate indexes for means and ends, which can be more usefully related to one another in terms of productivity (one index divided by the other), or as dependent and independent variables (one index in a functional relationship to the other).
Lipase catalyzed synthesis of ester‐based surfactants from biomass derivatives
Authors: Karmee Sanjib Kumar 
Published: February 2008

AbstractNon‐ionic surfactants find a unique place in pharmaceutical, detergent, food, and cosmetic industries because of their ready availability from biomass, low cost, and renewability. Generally these surfactants are esters obtained from the reaction of glycerol, L‐ascorbic acid, and sugar, with long or medium chain fatty acids. Problems encountered during the synthesis of these surfactants are the immiscibility of highly polar substrates in organic solvents and non‐regioselective reaction. Therefore, lipases as a catalyst and t‐butanol or acetone, a mixture of solvent and ionic liquid as solvents, have been used for the synthesis of ester‐based surfactants. This review focuses on the uses of lipases for the synthesis of surfactants obtained from biomass derivatives viz. fats and oils, sugar and vitamin‐C. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
Rotating versus perfusion bioreactor for the culture of engineered vascular constructs based on hyaluronic acid
Authors: Arrigoni Chiara , Chittò Annalisa , Mantero Sara , Remuzzi Andrea 
Published: February 2008

AbstractIt is generally accepted that dynamic culture conditions are required for vascular tissue engineering. We compared the effects of two dynamic culture systems, a perfusion and a rotating bioreactor, using tubular constructs based on hyaluronic acid seeded with porcine aortic smooth muscle cells (SMC), that we recently showed to be adequate for the generation of vascular tissue. In perfused constructs mechanical stimulation importantly affected cell morphology, increased the incidence of cell proliferation and reduced apoptosis. However, extracellular matrix deposition, cytoskeletal organization and mechanical properties were poor. In rotated constructs cell proliferation was also higher and apoptosis lower than in static controls. Rotated constructs showed the highest ultimate stress and the lowest elastic modulus. Our data indicate that the rotating bioreactor is more efficient than the perfusion bioreactor and we then suggest that this method can be considered a valid alternative to complex bioreactor systems described in the literature. Biotechnol. Bioeng. 2008;100: 988–997. © 2008 Wiley Periodicals, Inc.
Metabolic capacity estimation of Escherichia coli as a platform for redox biocatalysis: constraint‐based modeling and experimental verification
Authors: Blank Lars M. , Ebert Birgitta E. , Bühler Bruno , Schmid Andreas 
Published: February 2008

AbstractWhole‐cell redox biocatalysis relies on redox cofactor regeneration by the microbial host. Here, we applied flux balance analysis based on the Escherichia coli metabolic network to estimate maximal NADH regeneration rates. With this optimization criterion, simulations showed exclusive use of the pentose phosphate pathway at high rates of glucose catabolism, a flux distribution usually not found in wild‐type cells. In silico, genetic perturbations indicated a strong dependency of NADH yield and formation rate on the underlying metabolic network structure. The linear dependency of measured epoxidation activities of recombinant central carbon metabolism mutants on glucose uptake rates and the linear correlation between measured activities and simulated NADH regeneration rates imply intracellular NADH shortage. Quantitative comparison of computationally predicted NADH regeneration and experimental epoxidation rates indicated that the achievable biocatalytic activity is determined by metabolic and enzymatic limitations including non‐optimal flux distributions, high maintenance energy demands, energy spilling, byproduct formation, and uncoupling. The results are discussed in the context of cellular optimization of biotransformation processes and may guide a priori design of microbial cells as redox biocatalysts. Biotechnol. Bioeng. 2008;100: 1050–1065. © 2008 Wiley Periodicals, Inc.
Azotobacter vinelandii Metal Storage Protein: “Classical” Inorganic Chemistry Involved in Mo/W Uptake and Release Processes
Authors: Schemberg Jörg , Schneider Klaus , Fenske Dirk , Müller Achim 
Published: February 2008

AbstractThe release of Mo (as molybdate) from the Mo storage protein (MoSto), which is unique among all existing metalloproteins, is strongly influenced by temperature and pH value; other factors (incubation time, protein concentration, degree of purity) have minor, though significant effects. A detailed pH titration at 12 °C revealed that three different steps can be distinguished for the Mo‐release process. A proportion of ∼15 % at pH 6.8–7.0, an additional 25 % at pH 7.2–7.5 and ca. 50 % (up to 90 % in total) at pH 7.6–7.8. This triphasic process supports the assumption of the presence of different types of molybdenum‐oxide‐based clusters that exhibit different pH lability. The complete release of Mo was achieved by increasing the temperature to 30 °C and the pH value to >7.5. The Mo‐release process does not require ATP; on the contrary, ATP prevents, or at least reduces the degree of metal release, depending on the concentration of the nucleotide. From this point of view, the intracellular ATP concentration is suggested to play—in addition to the pH value—an indirect but crucial role in controlling the extent of Mo release in the cell. The binding of molybdenum to the apoprotein (reconstitution process) was confirmed to be directly dependent on the presence of a nucleotide (preferably ATP) and MgCl2. Maximal reincorporation of Mo required 1 mM ATP, which could partly be replaced by GTP. When the storage protein was purified in the presence of ATP and MgCl2 (1 mM each), the final preparation contained 80 Mo atoms per protein molecule. Maximal metal loading (110–115 atoms/MoSto molecule) was only achieved, if Mo was first completely released from the native protein and subsequently (re‐) bound under optimal reconstitution conditions: 1 h incubation at pH 6.5 and 12 °C in the presence of ATP, MgCl2 and excess molybdate. A corresponding tungsten‐containing storage protein (“WSto”) could not only be synthesized in vivo by growing cells, but could also be constructed in vitro by a metalate–ion exchange procedure by using the isolated MoSto protein. The high W content of the isolated cell‐made WSto (∼110 atoms/protein molecule) and the relatively low amount of tungstate that was released from the protein under optimal “release conditions”, demonstrates that the W‐oxide‐based clusters are more stable inside the protein cavity than the Mo‐oxide analogues, as expected from the corresponding findings in polyoxometalate chemistry. The optimized isolation of the W‐loaded protein form allowed us to get single crystals, and to determine the crystal X‐ray structure. This proved that the protein contains remarkably different types of polyoxotungstates, the formation of which is templated in an unprecedented process by the different protein pockets. (Angew. Chem. Int. Ed. 2007, 46, 2408–2413).
ChemInform Abstract: A Facile Synthetic Method of α‐Quaternary‐β,γ‐unsaturated Aldehydes via the Stereoselective 1,4‐Elimination and α‐Regioselective Ferrier Reaction.
Authors: Tayama Eiji , Hashimoto Ryo 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Highly Enantioselective and cis‐Diastereoselective Cyclopropanation of Olefins Catalyzed by Ruthenium Complexes of (Iminophosphoranyl)ferrocenes.
Authors: Hoang Vo D. M. , Reddy Pattubala A. N. , Kim Tae‐Jeong 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Novel Approach for Ligand Promoted Palladium (II)‐Catalyzed Suzuki Coupling of Aryl Iodides and Bromides with Arylboronic Acid in Aqueous Media.
Authors: Pawar Shivaji S. , Shingare Murlidhar S. , Thore Shivaji N. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Bismuth Aluminate: A New High‐Tc Lead‐Free Piezo‐/ferroelectric.
Authors: Zylberberg Joel , Belik Alexei A. , Takayama‐Muromachi Eiji , Ye Zuo‐Guang 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetic Structure Study of Antiferromagnet NpPtGa5 by Neutron Diffraction.
Authors: Jonen S. , Metoki N. , Yamamoto E. , Homma Y. , Aoki D. , Shiokawa Y. , Onuki Y. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetization and Specific Heat Measurement of the Shastry—Sutherland Lattice Compounds: Ln2BaPdO5 (Ln: La, Pr, Nd, Sm, Eu, Gd, Dy, Ho).
Authors: Ozawa T. C. , Taniguchi T. , Kawaji Y. , Mizusaki S. , Nagata Y. , Noro Y. , Samata H. , Mitamura H. , Takayanagi S. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The Al—B—Nb—Ti System. Part 1. Re‐Assessment of the Constituent Binary Systems B—Nb and B—Ti on the Basis of New Experimental Data.
Authors: Witusiewicz V. T. , Bondar A. A. , Hecht U. , Rex S. , Velikanova T. Ya. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Direct Atomic Scale Observation of Linkage Isomerization of As4S4 Clusters During the Photoinduced Transition of Realgar to Pararealgar.
Authors: Naumov Pance , Makreski Petre , Jovanovski Gligor 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Honeycomb Layer of Cobalt(II) Azide Hydrazine Showing Weak Ferromagnetism.
Authors: Wang Xiu‐Teng , Wang Zhe‐Ming , Gao Song 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Highly Diastereoselective and Enantioselective Direct Organocatalytic anti‐Selective Mannich Reactions Employing N‐Tosylimines.
Authors: Cheng Lili , Han Xiao , Huang Huiming , Wong Ming Wah , Lu Yixin 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Exceptionally Active Yttrium—Salen Complexes for the Catalyzed Ring Opening of Epoxides by TMSCN and TMSN3.
Authors: Saha Biswajit , Lin Mei‐Huey , RajanBabu T. V. 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Efficient Aerobic Oxidation of Phosphines, Phosphites, and Sulfides by Using Trialkylborane.
Authors: Motoshima Kosuke , Sato Akinori , Yorimitsu Hideki , Oshima Koichiro 
Published: February 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.