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排序方式: 共有1062条查询结果,搜索用时 15 毫秒
81.
Karin Pichler Stefan Fischerauer Peter Ferlic Elisabeth Martinelli Hans-Peter Brezinsek Peter J. Uggowitzer Jörg F. Löffler Annelie-Martina Weinberg 《JOM Journal of the Minerals, Metals and Materials Society》2014,66(4):573-579
The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients. 相似文献
82.
Angel Kirchev Florence Mattera Elisabeth Lemaire Kien Dong 《Journal of power sources》2009,191(1):82-90
The paper discusses the influence of the state of charge and pulse charge frequency on the mechanism of the lead-acid battery recharge with pulse current. The data from the pulse charge transients of the negative plate potential at various frequencies show that a decrease of the pulse charge frequency keeping constant average pulse current can impede the charge reaction leading to earlier start of the hydrogen evolution reaction. The dependence of the electrochemical double layer (EDL) capacitance on the state of charge was estimated both during the charge and the discharge using electrochemical impedance spectroscopy measurements at open circuit, followed by equivalent circuit modelling. These data were used to derive the dependence of the average double layer current on SOC and pulse charge frequency. The results show that in the end of the charge almost all of the charge proceeds with the participation of EDL in a certain pulse frequency domain. Using the data from the impedance measurements the optimal pulse charge frequencies were predicted, considering the existence of “electrochemical resonance”. The latter appears when the pulse charge frequency approaches the characteristic frequency of the Pb electrodeposition process, given by the product between EDL capacitance and the charge transfer resistance. 相似文献
83.
Elisabeth Van Hecke Phong‐Uyen Nguyen Danièle Clausse Jean‐Louis Lanoisellé 《International Journal of Food Science & Technology》2012,47(1):177-185
Rheological properties of carrot puree were investigated in the 1–1000 s?1 shear rate range with the objective of modelling the influence of time, temperature and addition of potato flakes on the flow behaviour. Carrot puree exhibited a shear‐thinning behaviour that was well described by the Ostwald‐de Waele (Power Law) model with a flow behaviour index of 0.34 (±0.02) at 20 °C. The time‐dependent behaviour was characterised by a second‐order Structural Kinetic Model. The decay of the structural parameter with time was found to be independent of shear rate. The Arrhenius model was used to explain the effect of temperature in the range from 4 to 60 °C. The dry matter was increased by adding potato flakes (0–5%). A power law model (for the concentration) and the Arrhenius relationship (for the temperature) were combined to simultaneously describe the effects of temperature and concentration. This study provides essential data for equipment and process design. 相似文献
84.
Optimum conditions for scaling up the synthesis of furyl-2 oxyrane from furfural have been determined. A continuous stirred tank reactor proved the most efficient configuration for the production of the oxirane. The kinetic model makes it possible to predict the yields of epoxide per unit volume and unit time. 相似文献
85.
Elisabeth Hochschorner Joakim Hgvall Gran Finnveden Evan Griffing Michael Overcash 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(3):461-475
Organisations today face increasing environmental constraints, e.g. in the form of legal and customer requirements; the defence sector is no exception. There is a need to evaluate and limit environmental effects of defence activities and materiel. In this study we used quantitative Life Cycle Assessment (LCA) and a method for simplified LCA (the Material, Energy, Chemicals and Others (MECO) method) to assess the environmental impacts of a grenade. The aims of the study are to identify aspects in the grenade's life‐cycle that have the largest environmental impact, suggest improvement possibilities, make a comparison between different approaches for waste management of munitions, and to perform a demonstrative case for the application of LCA to munitions. Significant environmental aspects of the grenade's life‐cycle include use of metals, use of fossil fuels, and detonation outdoors. The study shows that an LCA can be used to analyse environmental impacts from munitions. The simplified LCA gave information that is complementary to the quantitative LCA. Copyright © 2005 Society of Chemical Industry 相似文献
86.
EPDM elastomers have been synthesized by the Ziegler-Natta oatalytic system VOCl3/Al2Et3Cl3 with the objetive of verifying the influence of termonomers on terpolymer synthesis and on the properties of peroxide-vulcanized terpolymer compositions. Two groups of termonomers have been studied. Dienes, i.e., dicyclopentadiene (DCP), 5-ethylidene-2-norbornene (ENB) and limonene, and aromatic compounds, i.e., indene (IND) and styrene (ST). The influence on the synthesis has been verified by yield, termonomer incorporation, and molecular weight distri bution. The vulcanizate properties have included mechanical and electrical properties. 相似文献
87.
RAin Elisabeth Wiesner 《Datenschutz und Datensicherheit - DuD》2007,31(8):604-607
Zusammenfassung Das Interesse der Unternehmen, an personenbezogene Daten zu gelangen und diese für Werbezwecke zu verwerten, ist gro?. An
die Einholung von Einwilligungen zur Verarbeitung solcher Daten stellte die Rechtsprechung daher hohe Anforderungen. Die herrschende
Meinung ging bislang davon aus, dass Einwilligungen in Werbema?nahmen, die mittels Opt-out-Verfahren erlangt wurden, unwirksam
sind. Bereits im vergangenen Jahr hatte das Oberlandesgericht München erneut darüber zu entscheiden, ob eine Opt-out-Klausel
den datenschutzrechtlichen Anforderungen nach § 4a BDSG entspricht — und bejahte überraschenderweise die Wirksamkeit der Einwilligung. 相似文献
88.
89.
Marx Elisabeth M.; Williams J. Mark; Claridge Gordon C. 《Canadian Metallurgical Quarterly》1992,101(1):78
20 depressed patients with major depressive disorder, 20 nondepressed matched control Ss, and 17 patients with anxiety disorders were compared in different measures of social problem solving. Problem solving was assessed with the Means-Ends Problem-Solving Test (Study 1), the solution of personal problems, and a problem-solving questionnaire (Study 2). Results showed that, as predicted, depressed Ss suffered from a deficit in problem solving in all 3 measures. The majority of these deficits were also displayed by the clinical control group rather than being specific to a diagnosis of depression. However, depressed Ss produced less effective solutions than did normal and clinical control Ss. The results suggest that depressed and anxious patients may have difficulties at different stages of the problem-solving process. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
90.