bluuebunny/crossref_metadata_2025_split huggingface dataset:
Agricultural nitrogen, phosphorus and potassium balances in Germany —Methodology and trends 1970 to 1995
Authors: Bach Martin , Frede Hans‐Georg 
Published: December 2011

AbstractThe nitrogen, phosphorus and potassium balances for agriculture in Germany during the period 1970 to 1995 (western states) and 1990 to 1995 (entire Germany including the states of the former German Democratic Republic), respectivly, are calculated according to the PARCOM guidelines. The surplus of the basic national mineral balance is subdivided into the crop production surplus and the livestock production balance surplus. In the former West German states, P and K basic surpluses have declined about 60% since 1980, while the N‐surplus has dropped 23% since 1987. The efficiency of agricultural nutrient use has improved correspondingly. A sensitivity analysis and an error estimation reveal the accuracy of the results. The relevance and limits of interpreting nutrient balances on a national scale are clarified by a critical appraisal of the balance surplus values.
Prediction of mineralizable nitrogen in soils on the basis of an analysis of extractable organic N
Authors: Appel Thomas , Mengel Konrad 
Published: December 2011

AbstractMost of the nitrogen (N) in agricultural soils is organically bound, while the N uptake by plants and also the N losses from the soil‐plant system into the environment are as inorganic N. The electro‐ultrafiltration (EUF) method and the extraction by a CaCl2 solution extract an organic N fraction (Norg) that is thought to provide information about the amount of rapidly mineralizable N in soils. This paper aims to illustrate various aspects regarding the biological meaning of the Norgfractions extracted by these two extraction methods and also the opportunities and limitations for predicting the mineralizable N based on an Norg analysis.From an evaluation of numerous data on EUF and CaCl2 extract‐able Norg fractions we concluded that these methods extract N compounds which can be used as indices for easily mineralizable soil N. However, both methods extract only some of the rapidly mineralizable N in soils, and some of the Norg ecxtracted appears to be from the more recalcitrant soil organic N. This was particularly true for the EUF‐method. It may therefore be desirable to improve both the extractability and the selectivity of the extraction methods. This may be achieved by measuring extractable amino‐N compounds instead of the total extractable Norg.Evaluating the numerous field experiments done during the last decade shows that the calibration factors obtained for extractable Norg were not the same for different growing seasons, geographical regions and management practices. Theoretically, for each combination of these factors separate calibrations would be necessary. It is this inflexibility which appears to be the most serious drawback for the use of extractable Norg fractions in practice.A possible solution may be to combine the flexibility of a simulation model with additional information obtained by the analysis of extract‐able soil organic N. Further work in this direction may be desirable.
Use of a coupled equilibrium model to describe the buffering of protons and hydroxyl ions in some acid soils
Authors: Ludwig Bernard , Khanna Partap , Prenzel Jürgen 
Published: December 2011

AbstractThe buffering of protons and hydroxyl ions in acid soils was studied by the addition of small amounts of HCl, H2SO4, and NaOH in consecutive batch experiments using surface soils and subsoils from two Cambisols and one Podzol. A chemical equilibrium model was used to study the main buffer processes. The model included inorganic complexation and multiple cation exchange, and also the solubility of jurbanite and Al(OH)3 for the subsoils.Buffering of protons was predicted quite well by the model for the surface soil of the Spodi‐Dystric and Spodic Cambisols, suggesting that multiple cation exchange was the main buffer process. For the Podzol surface soil, however, the model overestimated proton buffering by cation exchange considerably. Hydroxyl buffering in acid surface soils could be described well by the model for the Podzol soil only. For the Cambisols, hydroxyl buffer reactions included not only cation exchange, but also solubilization of large amounts of organic matter and presumably deprotonation of dissolved organic carbon (DOC).Modelling proton and hydroxyl buffering in subsoils suggested that equilibrium with AJ(OH)3 was not maintained for the Podzol and spodic Cambisol. Sulphate sorption had to be considered to describe titration experiments in all three soils. The assumption of jurbanite being in equilibrium with soil extracts was useful only for the Spodi‐Dystric Cambisol.
Abbau von Huminstoffen durch Bodenmikroorganismen — eine Übersicht
Authors: Filip Zdenek , Claus Harald , Dippell Gerald 
Published: December 2011

AbstractHuminstoffe als die unterschiedlich extrahierbaren Fraktionen der organischen Bodensubstanz beeinflussen auf vielseitige Weise die Qualität des Bodens als Pflanzenstandort und Bestandteil der Umwelt. Insbesondere Huminsäuren und Fulvosäuren können biologischen Umsetzungen durch die Bodenmikroorganismen unterliegen. Von vielen Autoren wurde die Beteiligung unterschiedlicher Spezies von Pilzen und Aktinomyceten sowie von nichtmyzelartigen aeroben und anaeroben Bakterien am Ab‐ und Umbau von Huminstoffen unter Laborbedingungen nachgewiesen. Es gibt mehrere Hinweise auf einen strukturspezifischen Huminstoffabbau, der auf Zelloberflächen unter Beteiligung von Exoenzymen stattfindet. Die herausragende Rolle phenoloxidierender Enzyme bei diesen Prozessen konnte bestätigt werden. Der Abbau der Huminstoffe wird optisch, gravimetrisch, chemoanalytisch, biochemisch (CO2−Freisetzung) oder biologisch anhand des Mikrobenwachstums bzw. der Biomassebildung verfolgt. Seine quantitative Erfassung kann durch die Adsorption der Huminstoffe an der Mikrobenbiomasse einerseits und durch die Neubildung huminstoffähnlicher Stoffwechselprodukte andererseits erschwert werden. Es ist daher notwendig, den Abbau‐ und Umbauprozeß mehrfaktoriell zu verfolgen und gleichermaßen quantitative wie auch qualitative Parameter zu berücksichtigen. Um den natürlichen Standortbedingungen näher zu kommen, sollen Mischpopulationen von Mikroorganismen in die Untersuchungen des Huminstoffabbaus verstärkt einbezogen werden.
Magnesium‐ und Calcium‐Ernährung von Hochlagenfichten —Vergilbungszustand und Reaktion auf unterschiedliche Düngung
Authors: Gülpen Martin , Feger Karl‐Heinz 
Published: December 2011

AbstractAuf den ARINUS‐Versuchsflächen im Schwarzwald wurden seit 198V Untersuchungen zum Mincralstoffhuushult der aufstockenden Fichtenbestände mit unterschiedlicher experimenteller Düngung durchgeführt. Hierbei stand das Nährelement Mg im Vordergrund, da auf den Flächen zu Beginn der Untersuchungen Symptome der “montanen Vergilbung der Fichte” (akuter Mg‐Mangel) zu beobachten waren. Die erfolgten Behandlungen mit Ammonsulfat, Kieserit und Dolomit hatten eine experimentelle Beeinflussung der Mg‐Ernährung zum Ziel. Im Rahmen dieser Arbeit werden Ergebnisse zum Vergilbungszustand, zur langfristigen Entwicklung der nadelanalytisch belegten Bestandesernährung, sowie zu den Bindungsformen von Ca und Mg in Nadeln und im Holz vorgestellt. Durch Gaben Mg‐haltiger Düngemittel wurde die Mg‐Versorgung der Fichten deutlich verbessert und eine Wiederergrünung der vergilbten Bestände erreicht. Die Kieseritgabe erbrachte hierbei die schnellste Verbesserung der Mg‐Versorgung. Im Gegensatz zu Mg konnte bei Ca kein Mangel festgestellt werden. Die Ergebnisse der (NH4)2SO4−Gaben zeigen, daß hohe N‐Einträge latente Mineralstoffmängel, z.B. von Mg, verstärken können. Durch die depositionsbedingt verbesserte N‐Verfügbarkeit ist gegenwärtig auf vielen Standorten ein erhöhtes Risiko von Ernährungsungleichgewichten gegeben. Um dem wirkungsvoll zu begegnen, sollten Kalkungcn bzw. Düngungen nährelemenl‐ und standortspezifische Aspekte stärker berücksichtigen. Zur langfristigen Sicherstellung der Bestandesernährung sind die tieferwurzelnden Baumarten Buche und Tanne waldbaulieh stark zu fördern.
Parameterization and regionalization of Cd sorption characteristics of sandy soils. II. Regionalization: Freundlich k estimates by pedotransfer functions
Authors: Springob Günther , Böttcher Jürgen 
Published: December 2011

AbstractThe aim was to describe Cd sorption in spatially variable sandy soils of the ‘Fuhrberger Feld’ catchment area as a prerequisite for prognosis of Cd transport in soil and of the threat of groundwater pollution. Thus, the possibility is evaluated to derive a generalized Freundlich equation based on multiple regressions relating the retention parameters k and M (from isotherm data of part 1 of this study) to basic soil properties (pedotransfer functions). For the parameter M (exponent), the correlation ‘measured vs estimated’ was weak (r2 < 0.5) whereas k was well predictable by pedotransfer functions. The best regression was obtained if organic carbon (OC). clay content and H+ activity were combined as independent variables (r2 up to 0.96). The obtained k values were much higher than those from comparable literature models, probably due to lower ionic strength and different composition of our background solutions used for the isotherms. As a critical evaluation, the estimates for k were used to derive solute Cd concentrations (Cest) which then were compared to measured data (range 0.1–3 μg L−1). The best but still unsatisfactory r2 was 0.77, obtained if Gest was compared to Cd in 0.01 Mc Ca(NO3)2 equilibria (Cd0). Cd in fresh soil solution (Cdz) showed no significant correlation with Cest, except for one relationship where OC had been excluded from the preceding multiple regression of k. Generally, the role of the variable OC remained unclear. Direct multiple regressions of measured solute Cd vs soil properties (bypassing k, no sorbed fraction) yielded much closer correlations, with r2 = 0.9 for Cd0 vs OC, H+ activity, clay (log data, OC decreases C) and r2 = 0.7 for Cd2 vs OC, H+ activity, clay (log data, OC enhances C).
Hierarchical, Plasma Nanotextured, Robust Superamphiphobic Polymeric Surfaces Structurally Stabilized Through a Wetting–drying Cycle
Authors: Gnanappa Arun Kumar , Papageorgiou Dimitrios P. , Gogolides Evangelos , Tserepi Angeliki , Papathanasiou Athanasios G. , Boudouvis Andreas G. 
Published: December 2011

AbstractPlasma etched and simultaneously randomly roughened (nanotextured) polymethylmethacrylate (PMMA) substrates show hierarchical roughness and complex high‐aspect‐ratio morphology. Here, they are investigated as superamphiphobic surfaces, after plasma deposition of a thin fluorocarbon film. Inspired by the need to allow their “real world” use, we explore two major stability issues of such superamphiphobic surfaces: (i) the structural stability of the nanotexture against capillary and adhesion forces during successive wetting–drying cycles, and (ii) the thermodynamic stability (robustness) of these surfaces related to the maximum sustainable pressure of the Cassie–Baxter inhomogeneous wetting state. We show that surfaces etched in oxygen plasma up to 4 min (with texture height ≈600 nm) are stable against successive wetting–drying cycles, while surfaces treated for longer time show highly porous nanofibrous morphology which is coalesced and stabilized upon wetting, allowing their potential long‐term use. Robust superhydrophobic and superoleophobic behavior is observed in drop compression tests with water (on 2, 4, 10 min plasma etched surfaces) and diiodomethane (on 4 and 10 min plasma etched surfaces), respectively, and no wetting transition is observed for these two liquids even at maximum drop compression possible (1.5 kPa). Robust oleophobic behavior with sticky surfaces is observed for 1 and 2 min etching and with diiodomethane without transition to wetted states even upon maximum compression. On the contrary, wetting transition is observed for soya oil upon repeated compression.magnified image
Glycine insertion at protease cleavage site of SNAP25 resists cleavage but enhances affinity for botulinum neurotoxin serotype A
Authors: Ho Mengfei , Goh Cheong‐Hian , Brothers Michael C. , Wang Shihua , Young Ryan L. , Ou Yuxiang , Lui Juliana Nga‐Man , Kalafatis Marinos , Lan Xiuwan , Wolf Abigail E. , Rienstra Chad M. , Wilson Brenda A. 
Published: December 2011

AbstractThe light chain of botulinum neurotoxin A (BoNT/A‐LC) is a Zn‐dependent protease that specifically cleaves SNAP25 of the SNARE complex, thereby impairing vesicle fusion and neurotransmitter release at neuromuscular junctions. The C‐terminus of SNAP25 (residues 141–206) retains full activity for BoNT/A‐LC‐catalyzed cleavage at P1‐P1' (Gln197‐Arg198). Using the structure of a complex between the C‐terminus of SNAP25 and BoNT/A‐LC as a model to design SNAP25‐derived pseudosubstrate inhibitors (SNAPIs) that prevent presentation of the scissile bond to the active site, we introduced multiple His residues to replace Ala‐Asn‐Gln‐Arg (residues 195–198) at the substrate cleavage site, with the intent to identify possible side‐chain interactions with the active site Zn. We also introduced multiple Gly residues between the P1‐P1' residues to explore the spatial tolerance within the active‐site cleft. Using a FRET substrate YsCsY, we compared a series of SNAPIs for inhibition of BoNT/A‐LC. Among the SNAPIs tested, several known cleavage‐resistant, single‐point mutants of SNAP25 were poor inhibitors, with most of the mutants losing binding affinity. Replacement with His at the active site did not improve inhibition over wildtype substrate. In contrast, Gly‐insertion mutants were not only resistant to cleavage, but also surprisingly showed enhanced affinity for BoNT/A‐LC. Two of the Gly‐insertion mutants exhibited 10‐fold lower IC50 values than the wildtype 66‐mer SNAP25 peptide. Our findings illustrate a scenario, where the induced fit between enzyme and bound pseudosubstrate fails to produce the strain and distortion required for catalysis to proceed.
Green/yellow luminescence from highly strained BeZnCdSe quantum wells grown by molecular beam epitaxy
Authors: Kasai J. , Akimoto R. , Hasama T. , Ishikawa H. , Fujisaki S. , Tanaka S. , Tsuji S. 
Published: December 2011

AbstractWe have investigated the luminescent properties of highly strained BeZnCdSe quantum wells (QWs). Single‐QW structures were grown on (001) n‐GaAs substrates by molecular beam epitaxy with various Cd beam pressures. High‐resolution X‐ray diffraction measurements revealed that the lattice mismatch between the BeZnCdSe QW and the GaAs substrate changed from 2.1% to 3.0% as the Cd beam pressure was increased. The photoluminescence (PL) spectra showed that the peak wavelength was nearly proportional to the lattice mismatch for each sample. Fluorescence microscopy measurements revealed that the PL images of all the samples showed a similar luminescence distribution, but the images of samples having the lattice mismatch of 2.8% and 3.0% showed some dark lines. These results suggest that flat QW layers were formed in all the samples, but the lattice relaxation of the QW layer occurred in highly strained samples with lattice mismatches greater than 2.8%. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of AlN material properties through vibration analysis of thin membranes
Authors: Lebedev Vadim , Knöbber Fabian , Heidrich Nicola , Sah Ram Ekwal , Pletschen Wilfried , Cimalla Volker , Ambacher Oliver 
Published: December 2011

AbstractIn this work, the mechanical properties of thin piezoelectric AlN films along with the methods and instruments to obtain this information with sufficient accuracy via dynamic (vibration) and static analyses of thin membranes are reported. In addition, the impact of different damping mechanisms on the amplitude of forced oscillations have been considered in order to obtain the analytical expression relating the resonant amplitude of membrane to the ambient gas pressure. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
InGaAs HEMTs with T‐gate electrodes fabricated using HMDS SiN mold
Authors: Yoshida Tomohiro , Akagawa Keisuke , Otsuji Taiichi , Suemitsu Tetsuya 
Published: December 2011

AbstractWe report a method using SiN molds to controlling the shape of T‐gate electrodes. The SiN molds were constructed of multilayer SiN films with different etching properties. The SiN was deposited by plasma‐enhanced chemical vapor deposition using hexamethyldisilazane (HMDS) vapor. The SiN molds were used to fabricate T‐gate electrodes for InGaAs high electron mobility transistors (HEMTs). Two types of HEMTs were fabricated using the molds with different SiN layer structures. The gate delay analysis of the HEMTs showed that the difference in the parasitic gate delay reflects the shape of the T‐gate electrodes. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Halide based MBE of crystalline metals and oxides
Authors: Greenlee Jordan D. , Calley W. Laws , Henderson Walter , Doolittle W. Alan 
Published: December 2011

AbstractA halide based growth chemistry has been demonstrated which can deliver a range of transition metals using low to moderate effusion cell temperatures (30‐700 °C) even for high melting point metals. Previously, growth with transition metal species required difficult to control electron beam or impurity inducing metal organic sources. Both crystalline oxide and metal films exhibiting excellent crystal quality are grown using this halide‐based growth chemistry. Films are grown using a plasma assisted Molecular Beam Epitaxy (MBE) system with metal‐chloride precursors. Crystalline niobium, cobalt, iron, and nickel were grown using this chemistry but the technology can be generalized to almost any metal for which a chloride precursor is available. Additionally, the oxides LiNbO3 and LiNbO2 were grown with films exhibiting X‐ray diffraction (XRD) rocking curve full‐widths at half maximum of 150 and 190 arcseconds respectively. LiNbO2 films demonstrate a memristive response due to the rapid movement of lithium in the layered crystal structure. The rapid movement of lithium ions in LiNbO2 memristors is characterized using impedance spectroscopy measurements. The impedance spectroscopy measurements suggest an ionic current of.1 mA for a small drive voltage of 5 mV AC or equivalently an ionic current density of ∼87 A/cm2. This high ionic current density coupled with low charge transfer resistance of ∼16.5 Ω and a high relaxation frequency (6.6 MHz) makes this single crystal material appealing for battery applications in addition to memristors. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stabilization and regulator design for a one‐dimensional unstable wave equation with input harmonic disturbance
Authors: Guo Wei , Guo Bao‐Zhu 
Published: December 2011

SUMMARYThis paper considers the parameter estimation and stabilization of a one‐dimensional wave equation with instability suffered at one end and uncertainty of harmonic disturbance at the controlled end. The backstepping method for infinite‐dimensional system is adopted in the design of the adaptive regulator. It is shown that the resulting closed‐loop system is asymptotically stable. Meanwhile, the estimated parameter is shown to be convergent to the unknown parameter as time goes to infinity. Copyright © 2011 John Wiley & Sons, Ltd.
Nanoscale Localization Sampling Based on Nanoantenna Arrays for Super‐resolution Imaging of Fluorescent Monomers on Sliding Microtubules
Authors: Kim Kyujung , Yajima Junichiro , Oh Youngjin , Lee Wonju , Oowada Shinsuke , Nishizaka Takayuki , Kim Donghyun 
Published: December 2011

AbstractSub‐diffraction‐limited imaging of fluorescent monomers on sliding microtubules in vitro by nanoscale localization sampling (NLS) is reported. NLS is based on periodic nanohole antenna arrays that create locally amplified electromagnetic hot spots through surface plasmon localization. The localized near‐field hot spot temporally samples microtubular movement for enhanced spatial resolution. A fourfold improvement in spatial resolution compared to conventional wide‐field microscopy is demonstrated. The resolution enhancement is achieved by imaging rhodamine‐labeled microtubules that are sampled by the hot spots to provide sub‐diffraction‐limited images at 76 nm resolution in the direction of movement and 135 nm orthogonally. The intensity distribution produced by the NLS is measured to be broader than that of conventional imaging, which is consistent with the improvement of imaging resolution. Correlation studies between neighboring nanoantennas are also performed. This confirms the possibility of measuring microtubular transport dynamics. NLS can be useful for moving objects that have a high labeling density or for performing fluctuation spectroscopy in small volumes, and may allow “super‐resolution on demand” by customizing nanoantenna structures for specific resolution needs.
Regenerative nanomedicine and the treatment of degenerative retinal diseases
Authors: Zarbin Marco A. , Montemagno Carlo , Leary James F. , Ritch Robert 
Published: December 2011

AbstractRegenerative medicine deals with the repair or the replacement of tissues and organs using advanced materials and methodologies. Regenerative nanomedicine uses nanoparticles containing gene transcription factors and other modulating molecules that allow reprogramming of cells in vivo as well as nanomaterials to induce selective differentiation of neural progenitor cells and to create neural‐mechanical interfaces. In this article, we consider some applications of nanotechnology that may be useful for the treatment of degenerative retinal diseases, for example, use of nanoparticles for drug and gene therapy, use of nanomaterials for neural interfaces and extracellular matrix construction for cell‐based therapy and neural prosthetics, and the use of bionanotechnology to re‐engineer proteins and cell behavior for regenerative medicine. WIREs Nanomed Nanobiotechnol 2012, 4:113–137. doi: 10.1002/wnan.167This article is categorized under:

Implantable Materials and Surgical Technologies > Nanomaterials and Implants
Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease
Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement
Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery
Mechanistic Studies of Particulate Soil Detergency: I. Hydrophobic Soil Removal
Authors: Rojvoranun Sureeporn , Chadavipoo Chairat , Pengjun Wikanda , Chavadej Sumaeth , Scamehorn John F. , Sabatini David A. 
Published: December 2011

AbstractThe mechanism of particulate soil detergency using aqueous surfactant systems is not well understood. In this research, carbon black (model hydrophobic soil) removal from a hydrophilic (cotton) and hydrophobic (polyester) fabric is studied using anionic, nonionic, and cationic surfactants. The zeta potential, solid/liquid spreading pressure, contact angle and surfactant adsorption of both soil and fabric are correlated to detergency over a range of surfactant concentrations and pH levels. Electrostatic repulsion between fabric and soil is generally found to be the dominant mechanism responsible for soil removal for all surfactants and fabrics. Steric effects due to surfactant adsorption are also important for nonionic surfactants for soil detachment and antiredeposition. Solid/liquid interfacial tension reduction due to surfactant adsorption also aids in detergency in cationic surfactant systems. Wettability is not seen as being an important factor and SEM photos show that entrapment of soil in the fabric weave is not significant; the particles are only attached to the fabric surface. Anionic surfactants perform best, then nonionic surfactants. Cationic surfactants exhibit poor detergency which is attributed to low surfactant rinseability.