bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rhizodeposition of maize: Short‐term carbon budget and composition
Authors: Fischer Holger , Eckhardt Kai‐Uwe , Meyer Axel , Neumann Günter , Leinweber Peter , Fischer Klaus , Kuzyakov Yakov 
Published: December 2009

AbstractThe aim of this study was to assess differences in rhizodeposition quantity and composition from maize cropped on soil or on 1:1 (w/w) soil–sand mixture and distribution of recently assimilated C between roots, shoots, soil, soil solution, and CO2 from root respiration. Maize was labeled in 14CO2 atmosphere followed by subsequent simultaneous leaching and air flushing from soil. 14C was traced after 7.5 h in roots and shoots, soil, soil solution, and soil‐borne CO2. Rhizodeposits in the leachate of the first 2 h after labeling were identified by high‐pressure liquid chromatography (HPLC) and pyrolysis–field ionization mass spectrometry (Py‐FIMS). Leachate from soil–sand contained more 14C than from soil (0.6% vs. 0.4%) and more HPLC‐detectable carboxylates (4.36 vs. 2.69 μM), especially acetate and lactate. This is either because of root response to lower nutrient concentrations in the soil–sand mixture or decreasing structural integrity of the root cells during the leaching process, or because carboxylates were more strongly sorbed to the soil compared to carbohydrates and amino acids. In contrast, Py‐FIMS total ion intensity was more than 2 times higher in leachate from soil than from soil–sand, mainly due to signals from lignin monomers. HPLC‐measured concentrations of total amino acids (1.33 μM [soil] vs. 1.03 μM [soil–sand]) and total carbohydrates (0.73 vs. 0.34 μM) and 14CO2 from soil agreed with this pattern. Higher leachate concentrations from soil than from soil–sand for HPLC‐measured carbohydrates and amino acids and for the sum of substances detected by Py‐FIMS overcompensated the higher sorption in soil than in sand‐soil. A parallel treatment with blow‐out of the soil air but without leaching indicated that nearly all of the rhizodeposits in the treatment with leaching face decomposition to CO2. Simultaneous application of three methods—14C‐labeling and tracing, HPLC, and Py‐FIMS—enabled us to present the budget of rhizodeposition (14C) and to analyze individual carbohydrates, carboxylates, and amino acids (HPLC) and to scan all dissolved organic substances in soil solution (Py‐FIMS) as dependent on nutrient status.
Soil organic‐matter stocks and characteristics along an Alpine elevation gradient
Authors: Djukic Ika , Zehetner Franz , Tatzber Michael , Gerzabek Martin H. 
Published: December 2009

AbstractMountain regions are known to be especially vulnerable to climatic changes; however, information on the climate sensitivity of alpine ecosystems is still scarce to date. In this study, we investigate the impacts of climate and vegetation composition on soil organic‐matter (SOM) stocks and characteristics along an elevation gradient (900 to 1900 m asl) in the Austrian Limestone Alps. The soils classified as Leptic Histosols, i.e., organic soils directly overlying the calcareous bedrock. Soil organic‐carbon stocks (SOC; mean ± standard deviation) to bedrock increased in the low‐elevation forest sites from 19 ± 3 kg m–2 (900 m asl) to 31 ± 3 kg m–2 (1300 m asl), reached a maximum (38 ± 5 kg m–2) in the shrubland at 1500 m asl, but decreased again in the high‐elevation grassland sites (26 ± 3 kg m–2 at 1700 m asl and 13 ± 3 kg m–2 at 1900 m asl). Thermogravimetic measurements and Fourier‐transform infrared spectroscopy (FTIR) suggest that the upper soil layers were dominated by more labile organic compounds, whereas more persistent materials increased with depth. Along the studied climosequence, the aliphatic FTIR band (2920 cm–1) was lower in the low‐elevation forest sites compared to the high‐elevation grassland sites. Most other FTIR bands did not change with altitude, but were related to specific site conditions, such as vegetation composition and associated differences in soil pH. Our results demonstrate that differences in SOM stocks and characteristics are not consistently related to variations in climatic conditions along the studied elevation gradient, but are strongly affected by the vegetation composition, their C input and litter quality. This, in turn, is expected to shift in response to climate change.
Volatile compounds profile and sensory evaluation of Beninese condiments produced by inocula of Bacillus subtilis
Authors: Azokpota Paulin , Hounhouigan Joseph D , Annan Nana T , Odjo Théophile , Nago Mathurin C , Jakobsen Mogens 
Published: December 2009

AbstractBACKGROUND: Three Beninese food condiments (ABS124h, IBS248h and SBS348h) were produced by controlled fermentation of African locust beans using inocula of pure cultures of Bacillus subtilis, BS1, BS2 and BS3, respectively. Quantitative and qualitative assessments of the volatile compounds in the condiments produced have been performed using the Likens–Nickerson simultaneous distillation–extraction method and GC–MS analysis, followed by a sensory evaluation in comparison with the spontaneously fermented condiments.RESULTS: A total of 94 volatile compounds have been found including 53 compounds identified in relatively high concentrations and were subdivided into seven main groups with the predominance of four major groups: pyrazines, aldehydes, ketones and alcohols. Compared to the spontaneously fermented condiments, volatile compounds identified in controlled fermented condiments have been found in high number and in concentrations which varied according to the inoculum of B. subtilis used. The condiments produced with starter cultures scored significantly (P < 0.05) higher for odour than the spontaneously fermented condiments. But the overall acceptability (7/10) of the two types of condiments was similar.CONCLUSION: The investigated B. subtilis, BS1, BS2 and BS3 can be considered as potential starter cultures for the fermentation of African locust beans to produce good quality of Beninese food condiments. Copyright © 2009 Society of Chemical Industry
Effect of different high pressure treatments on shucking, biochemical, physical and sensory characteristics of oysters to elaborate a traditional Taiwanese oyster omelette
Authors: Hsu Kuo‐Chiang , Hwang Jyh‐Sheng , Chi Hsin‐Yi , Lai Kung‐Ming 
Published: December 2009

AbstractBACKGROUND: Whole oysters (Crassostrea gigas) were processed using high‐pressure (HP) treatment (150–300 MPa) to determine their shucking and biochemical properties. Subsequently, HP‐treated oysters were cooked at 160 °C for 90 s, as when preparing the oyster omelette dish, to evaluate their physical and sensory characteristics as compared to raw oysters.RESULTS: The treatments of 250 and 300 MPa for 2 min and 0 min, respectively, resulted in 100% release. The pH of HP‐treated oysters increased slightly from 6.50 to 6.82, and the moisture contents of the HP‐treated oysters with or without further cooking were all higher than those of the control. The brightness, yellowness and cutting strength of HP‐treated oysters with further cooking changed insignificantly, while the redness decreased compared to the control. Sensory evaluation showed that oysters treated at 250 and 300 MPa oysters after cooking received higher quality scores than the control.CONCLUSIONS: HP processing at 250 and 300 MPa proved to be a good method for oyster shucking. The HP‐treated oysters cooked in the oyster omelette are acceptable to consumers. Overall, the application of HP as a processing method to improve the quality and acceptability of oysters and their related products would be possible. Copyright © 2009 Society of Chemical Industry
Polyaniline Morphology and Detectable Intermediate Aggregates
Authors: Ding Zhongfen , Yang Dali , Currier Robert P. , Obrey Stephen J. , Zhao Yusheng 
Published: December 2009

AbstractFormation of detectable intermediate aggregates is found to affect the morphologies of PANI nanomaterials, leading to either tubular or rod structures with striated growth and rough surfaces. By simply varying the ratio of initial proton and aniline concentration, a wide range of product morphologies can be synthesized. The intermediates form visible aggregates that can be separated by centrifugation or filtration. In addition to UV‐Vis monitoring of the intermediate aggregates, OCP and pH measurements are used to monitor the reaction process. GPC measurements show that the corresponding final products formed typically are not homogeneous. The correlation of intermediates formation and aggregation with product morphology suggests a route to controlled synthesis of PANI nanomaterials.magnified image
Chain Dynamics in Solid Polymers and Polymerizing Systems as Revealed by Broadband Dielectric Spectroscopy
Authors: Williams Graham 
Published: December 2009

AbstractBroadband Dielectric Spectroscopy (BDS) provides a direct, powerful means of studying the chain dynamics of solid polymers. The present work discusses experimental data, phenomenological theories, molecular theories and recent molecular dynamics simulations of the relaxation functions and average relaxation times for the multiple dielectric relaxations observed for amorphous polymers. Examples of current applications of BDS are given, including studies of the dynamics of ultra‐thin polymer films and real‐time studies of (i) the crystallization behaviour of bulk polymers and (ii) thermo‐polymerizing systems.
The Dynamic Impact Experiments Under Active Confining Pressure and the Constitutive Equation of PP/PA Blends at Multi‐Axial Compressive Stress State
Authors: Shaoqiu Shi , Bing Yu , Lili Wang 
Published: December 2009

AbstractSummary: A special active hydraulic confining pressure installation matched with Φ14.5 mm SHPB apparatus was developed. A series of active confining pressure impact experiments for PP/PA blends are performed in this special SHPB system under two kinds of axial strain rate: 8.0*102, 1.4*103 s−1 and the active confining pressure of 0 MPa, 4 MPa, 8 MPa, 12 MPa, 15 MPa, 20 MPa. The axial strain‐time profile, the axial stress‐time profile and the hoop strain‐time profile of the specimen are recorded online respectively. According to the equilibrium equation, the complete state of principal stress and principal strain of PP/PA blends under multi‐axial stress state is analyzed.The experimental results reveal that the axial stress‐strain curves all are related to the confining pressure and the strain rate. It can also be seen that under a constant effective strain rate the effective stress‐ effective strain curves at different confining pressures are coincident basically. This manifests that under a certain effective strain rate there is only one unique effective stress‐ effective strain curve. The multi‐axial constitutive equation for PP/PA blends is suggested finally as:

where σconf is the confining pressure value.

For 113 PP/PA blends, E = 2.98 GPa, α = −31.15 GPa, β = 93.31 GPa, θ2 = 8.54 µS, E2 = 0.82 GPa.
Characterization of Carbon Based Nanoparticles Dispersion in Aqueous Solution Using Dynamic Light Scattering Technique
Authors: Miglietta Maria Lucia , Rametta Gabriella , Di Francia Girolamo 
Published: December 2009

AbstractCharacterization of physicochemical properties of nanoparticles in aqueous environment prior to conducting hazard studies is strongly recommended by many scientific organizations. In this work we studied the dissolution behaviour and physicochemical properties of carbon based nanoparticles in aqueous solution. The time evolution of the size distribution and the state of dispersion of carbon black and carbon nanotubes in physiological solution have been investigated by means of Dynamic Light Scattering technique. The influence of mechanical agitation such as sonication and stirring on the agglomeration state and particle size distribution has been investigated. However, such processes seem to have little or no effect as far as agglomeration is concerned.
Electroless Copper Sulfide Deposition on the Polyacrylonitrile Films with Chelating Agents and its EMI Shielding Effectiveness
Authors: Roan Ming‐Lih , Chen Yen‐Hung , Liao Hao‐Hsiang , Huang Chi‐Yuan , Chen Kan‐Nan , Yeh Jen‐Taut 
Published: December 2009

AbstractIn this study, an effective deposition of copper sulfide (Cux(x = 1,2)S) on the PAN film was proposed by an electroless deposition method with the reduction agents NaHSO3 and Na2S2O3 · 5H2O and chelating agents (ethylenediaminetetraacetic acid, EDTA and triethanolamine, TEA). The mechanism of the Cux(x = 1,2)S growth and the electromagnetic interference shielding effectiveness (EMI SE) of the Cux(x = 1,2)S/PAN films were studied. It was found that the vinyl acetate monomer residue in the PAN substrate would be purged due to the swelling effect by EDTA and TEA solution. And then, the anchoring effect occurred due to the hydrogen bonding between the pits of the PAN substrate and the chelating agent. The swelling degree (Sd) was proposed and evaluated from the FT‐IR spectra. The relationship between swelling degree of the PAN films and EDTA concentration(C) is expressed as: Sd = 0.13 + 0.90 × eˆ(−15.15CEDTA). And TEA series is expressed as: Sd = 0.07 + 1.00 × eˆ(−15.15CTEA). On the other hand, the FESEM micrograph showed that the average thickness of copper sulfide increased from 76 nm to 383 nm when the concentration of EDTA increased from 0.00 M to 0.20 M. Consequently, the EMI SE of the Cux(x = 1,2)S/PAN films increased from 10∼12 dB to 25∼27 dB. The GIA‐XRD analyzer indicated that the deposited layer consisted of CuS and Cu2S.
Processing and Dynamic‐Mechanical Properties of Poly(butylen terephthalate) Based Nanocomposites
Authors: Russo P. , Acierno D. , Gallo E. 
Published: December 2009

AbstractEffects related to the simultaneous presence of an Al‐phosphinate based fire retardant and of relatively low amounts of nanosized metal oxide particles on processability and mechanical performances of a commercial polyester resin have been investigated. In more details, ternary poly(buthylene terephtalate) based compounds, obtained by melt processing and first of all validated in terms of flammability, were analysed to verify the relative extrudability and ultimate dynamic mechanical performances of compression moulded samples. Preliminary rheological tests confirmed both a minimum of matrix degradation as a result of the process while applying an appropriate protocol drying of raw materials and a marked reduction of the apparent shear viscosity of the three‐phase melts with respect to the neat matrix processed under the same conditions. Regarding the evaluation of dynamic‐mechanical parameters such as storage modulus, loss modulus and the ratio tan δ, besides the expected stiffening of the matrix by inclusion of a rigid inorganic phase, a slight reduction of damping behaviour without no significant variation of the glass transition temperature of the polyester matrix have been observed.
Effect of a Nanodispersed Clay Fillers on Glass Transition of Thermosetting Polyurethane
Authors: Corcione C. Esposito , Maffezzoli A. , Cannoletta D. 
Published: December 2009

AbstractIn this work polyurethane (PU) matrix nanocomposite, obtained using an organically modified montmorillonite (OMM), was synthesized and characterized. An amount of organoclay ranging from 2% up to 6% by volume was added to the polyol component of the resin before mixing with isocyanate. The microstructure of the composites was investigated by X‐ray diffraction. The glass transition temperature (Tg) of PU nanocomposites, measured using differential scanning calorimeter, increases with increasing the volume fraction of OMM. On the other hand, the heat capacity increment, ΔCp, decreases from that the unfilled PU to that of the sample with 5.7% vol of OMM. Therefore a corresponding increase of the rigid amorphous fraction of PU nanocomposites with nanoclay was observed. Finally, the definition of molecular cooperativity was discussed for this system and the characteristic length of the cooperative region was determined, using the approach proposed by Donth.
A Study of the Swelling Properties of Polymer Nanocomposites through Electrical and Optical Characterization
Authors: del Mauro Anna de Girolamo , La Ferrara Vera , Massera Ettore , Miglietta Maria Lucia , Polichetti Tiziana , Rametta Gabriella , Di Francia Girolamo 
Published: December 2009

AbstractIn the present study, polymer nanocomposite layers for sensing applications are characterized by means of an optical method based on white light interferometry. The study focuses on poly (hydroxy ethyl methacrylate) (PHEMA) and on nanocomposite Carbon black (CB)/PHEMA layers commonly used in chemical sensor technology for volatile organic compounds (VOCs) detection. The interferometric spectra of these two different materials, recorded during analyte exposure, are analyzed in terms of film expansion. Comparison between PHEMA and PHEMA/CB layer shows that the nanocomposite undergoes a more pronounced swelling process. In order to achieve a better comprehension of the sensing mechanism and to improve the sensor performances, the variations of the electrical signal of a nanocomposite‐based chemiresistor in presence of VOCs are examined and compared to the optical behaviour.
Oleuropein and hydroxytyrosol inhibit MCF‐7 breast cancer cell proliferation interfering with ERK1/2 activation
Authors: Sirianni Rosa , Chimento Adele , De Luca Arianna , Casaburi Ivan , Rizza Pietro , Onofrio Arianna , Iacopetta Domenico , Puoci Francesco , Andò Sebastiano , Maggiolini Marcello , Pezzi Vincenzo 
Published: December 2009

AbstractThe growth of many breast tumors is stimulated by estradiol (E2), which activates a classic mechanism of regulation of gene expression and signal transduction pathways inducing cell proliferation. Polyphenols of natural origin with chemical similarity to estrogen have been shown to interfere with tumor cell proliferation. The aim of this study was to investigate whether hydroxytyrosol (HT) and oleuropein (OL), two polyphenols contained in extra‐virgin olive oil, can affect breast cancer cell proliferation interfering with E2‐induced molecular mechanisms. Both HT and OL inhibited proliferation of MCF‐7 breast cancer cells. Luciferase gene reporter experiments, using a construct containing estrogen responsive elements able to bind estrogen receptor alpha (ERα) and the study of the effects of HT or OL on ERα expression, demonstrated that HT and OL are not involved in ERα‐mediated regulation of gene expression. However, further experiments pointed out that both OL and HT determined a clear inhibition of E2‐dependent activation of extracellular regulated kinase1/2 belonging to the mitogen activating protein kinase family. Our study demonstrated that HT and OL can have a chemo‐preventive role in breast cancer cell proliferation through the inhibition of estrogen‐dependent rapid signals involved in uncontrolled tumor cell growth.
Lupine, a source of new as well as hidden food allergens
Authors: Jappe Uta , Vieths Stefan 
Published: December 2009

AbstractThe present review summarizes current knowledge about lupine allergy, potential sensitization routes, cross‐reactions between lupine and other legumes, and the respective IgE‐binding proteins. Since the 1990s, lupine flour is used as a substitute for or additive to other flours, mostly wheat flour, in several countries of the EU. In 1994, the first case of an immediate‐type allergy after ingestion of lupine flour‐containing pasta was reported. Since then, the number of published incidents following ingestion or inhalation of lupine flour is rising. So far, the Lupinus angustifolius β‐conglutin has been designated as the allergen Lup an 1 by the International Union of Immunological Societies Allergen Nomenclature Subcommittee. Initially, publications focussed on the fact that peanut‐allergic patients were at risk to develop anaphylaxis to lupine due to cross‐reactivity between peanut and lupine. At present, however, the ratio between cases of pre‐existing legume allergy (mostly peanut allergy) to de novo sensitization to lupine seed is nearly 1:1. Although in December 2006, lupine and products thereof were included in the EU foodstuff allergen list according to the Commission Directive 2006/142/EC amending Annex IIIA of Directive 2000/13/EC in order to prevent severe reactions caused by “hidden food allergens”, the majority of patients and medical personnel are still not aware of raw lupine seed as potentially dangerous food allergen.
Pyrrolizidine alkaloids (PAs) in honey and pollen‐legal regulation of PA levels in food and animal feed required
Authors: Kempf Michael , Reinhard Annika , Beuerle Till 
Published: December 2009

AbstractPyrrolizidine alkaloids (PAs) are secondary plant constituents that comprise about 400 different structures and occur in two major forms, a tertiary form and the corresponding N‐oxide. PAs containing a 1,2‐double bond are pre‐toxins and metabolically activated by the action of hepatic P‐450 enzymes to toxic pyrroles. Besides the acute toxic effects, the genotoxic and tumorigenicity potential of PAs was demonstrated in some eukaryotic model systems. Recently, the potential PA contamination of food and feeding stuff attracted recurrent great deals of attention. Humans are exposed to these toxins by consumption of herbal medicine, herbal teas, dietary supplements or food containing PA plant material. In numerous studies the potential threat to human health by PAs is stated. In pharmaceuticals, the use of these plants is regulated. Considering the PA concentrations observed especially in authentic honey from PA producing plants and pollen products, the results provoke an international regulation of PAs in food.
Das Prinzip Katalyse
Authors: Quadbeck‐Seeger Hans‐Jürgen 
Published: December 2009

AbstractHans‐Jürgen Quadbeck‐SeegerDie Katalyse zählt zu den geheimnisvollsten Phänomenen der Natur, dennoch wird ihre fundamentale Bedeutung meist unterschätzt. Dabei steht fest: Das Leben wäre ohne die Katalyse und die darauf aufbauende Selbstorganisation der Materie nicht möglich.
Improving algebraic multigrid interpolation operators for linear elasticity problems
Authors: Baker A. H. , Kolev Tz. V. , Yang U. M. 
Published: December 2009

AbstractLinear systems arising from discretizations of systems of partial differential equations can be challenging for algebraic multigrid (AMG), as the design of AMG relies on assumptions based on the near‐nullspace properties of scalar diffusion problems. For elasticity applications, the near‐nullspace of the operator includes the so‐called rigid body modes (RBMs), which are not adequately represented by the classical AMG interpolation operators. In this paper we investigate several approaches for improving AMG convergence on linear elasticity problems by explicitly incorporating the near‐nullspace modes in the range of the interpolation. In particular, we propose two new methods for extending any initial AMG interpolation operator to exactly fit the RBMs based on the introduction of additional coarse degrees of freedom at each node. Though the methodology is general and can be used to fit any set of near‐nullspace vectors, we focus on the RBMs of linear elasticity in this paper. The new methods can be incorporated easily into existing AMG codes, do not require matrix inversions, and do not assume an aggregation approach or a finite element framework. We demonstrate the effectiveness of the new interpolation operators on several 2D and 3D elasticity problems. Copyright © 2009 John Wiley & Sons, Ltd.