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91.
92.
Claudio Sedivy Rafal Piskorski Andreas Müller Silvia Dorn 《Journal of chemical ecology》2012,38(8):996-1002
Growing evidence suggests that the freely accessible pollen of some plants is chemically protected against pollen-feeding flower visitors. For example, a diet of pollen from buttercup plants (Ranunculus) recently was shown to have a deleterious effect on developing larvae of several bee species not specialized on Ranunculus. Numerous Ranunculus species contain ranunculin, the glucosyl hydrate form of the highly reactive and toxic lactone protoanemonin, that causes the toxicity of these plants. We tested whether the presence of ranunculin is responsible for the lethal effects of R. acris pollen on the larvae of two bee species that are not Ranunculus specialists. To investigate the effect on bee larval development, we added ranunculin to the pollen provisions of the Campanula specialist bee Chelostoma rapunculi and the Asteraceae specialist bee Heriades truncorum, and allowed the larvae to feed on these provisions. We quantified ranunculin in pollen of R. acris and in brood cell provisions collected by the Ranunculus specialist bee Chelostoma florisomne. We demonstrated that although ranunculin was lethal to both tested bee species in high concentrations, the concentration in the pollen of R. acris was at least fourfold lower than that tolerated by the larvae of C. rapunculi and H. truncorum in the feeding experiments. Ranunculin concentration in the brood cells of C. florisomne was on average even twentyfold lower than that in Ranunculus pollen, suggesting that a mechanism different from ranunculin intoxication accounts for the larval mortality reported for bees not specialized on Ranunculus pollen. 相似文献
93.
Living Labs have received limited attention in the literature despite their diffusion throughout Europe and recent interest from policy makers. This limited attention is linked to the newness of the phenomenon, the high heterogeneity of cases and the consequent lack of definitions and acknowledged frameworks for scholarly analyses. In this work, we argue that the originality of the Living Lab phenomenon resides in the introduction of a new methodology. Using an analysis of the literature and case studies, we propose a new definition, position this methodology among other design methodologies and highlight its peculiarities. We underline the co‐creative potentialities, the awareness of users and the real‐life settings. Furthermore, our case‐based research allows us to identify four different specifications for this methodology, and therefore four different types of Living Labs, based on the openness of the user involvement and the adopted platform technology. 相似文献
94.
Roberta Bongiovanni Andrea Medici Alberto Zompatori Silvia Garavaglia Claudio Tonelli 《Polymer International》2012,61(1):65-73
Perfluoropolyether (PFPE) structures can be functionalized with acrylic groups using appropriate hydrogenated acrylic monomers: the macromers obtained are highly reactive under UV irradiation, and fluorinated polymers can be obtained. In the first part of this work is described the synthesis of new PFPE (meth)acrylic oligomers by extending OH‐terminated fluorinated chains with urethane groups and reactive acrylic functions. The photopolymerization reaction of each product is then reported followed by the characterisation of the main thermal, mechanical and surface properties of UV‐cured coatings. The polymers have good thermal resistance and fair mechanical and chemical resistance. More interestingly they show very low refractive index and low surface tension. For these latter properties the products can be advantageously used in highly demanding applications such as photonic devices and nano‐patterning. Copyright © 2011 Society of Chemical Industry 相似文献
95.
Giordana Feriotto Federico Tagliati Riccardo Giriolo Fabio Casciano Claudio Tabolacci Simone Beninati Mahmud Tareq Hassan Khan Carlo Mischiati 《International journal of molecular sciences》2021,22(4)
Among the phenolic acids tested on the K562 cell line, a model of chronic myeloid leukemia (CML), caffeic acid (CA) was biologically active on sensitive and imatinib (IM)-resistant cells at micro-molar concentration, either in terms of reduction of cell proliferation or triggering of apoptosis. The CA treatment provoked mitochondrial membrane depolarization, genomic DNA fragmentation and phosphatidylserine exposure, hallmarks of apoptosis. Cell cycle analysis following the treatment with comparable cytotoxic concentrations of IM or CA showed marked differences in the distribution profiles. The reduction of cell proliferation by CA administration was associated with increased expression of two cell cycle repressor genes, CDKN1A and CHES1, while IM at a cytotoxic concentration increased the CHES1 but not the CDKN1A expression. In addition, CA treatment affected the proliferation and triggered the apoptosis in IM-resistant cells. Taken together, these data suggested that CA induced the anti-proliferative effect and triggered apoptosis of CML cells by a different mechanism than IM. Finally, the combined administration of IM and CA at suboptimal concentrations evidenced a synergy of action in determining the anti-proliferative effect and triggering apoptosis. The ability of CA to potentiate the anti-leukemic effect of IM highlighted the nutraceutical potential of CA in CML. 相似文献
96.
Matías Pacheco Diego Celentano Claudio García-Herrera Julio Méndez Fernando Flores 《International Journal of Material Forming》2017,10(1):15-27
This paper presents the numerical simulation of an industrial multi-step deep drawing process. A large strain finite element formulation including a hyperelastic elastoplastic constitutive model and a contact-friction law is used to this end where the steel sheet material parameters considered in the analysis are previously derived through a characterization procedure of its mechanical response. The numerical predictions of the final shape and thickness distribution of the blank are compared and discussed with available experimental values measured at the end of three successive drawing steps. In addition, a plastic work-based damage index is used to assess failure occurrence during the process. The damage values computed at the end of the drawing process are found to be lower than that corresponding to rupture in the tensile test, considered here as the threshold of failure, confirming, as observed experimentally, that neither fracture nor necking is developed in the blank during the whole drawing process. Finally, the possibility to carry out a reduced two-step drawing process, obtained by merging the second and third steps of the three-step process, is precluded since the damage criterion predicts in this case excessively large values that indicate that failure may occur in specific zones of the sheet. 相似文献
97.
98.
Assessment of intradialysis calcium mass balance by a single pool variable‐volume calcium kinetic model
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Salvatore di Filippo Fabio Carfagna Vincenzo la Milia Antonio Bellasi Giustina Casagrande Camilla Bianchi Domenico Vito Maria Laura Costantino Giuseppe Rombolà Claudio Minoretti Carlo Schönholzer Giuseppe Pontoriero Francesco Locatelli 《Hemodialysis international. International Symposium on Home Hemodialysis》2018,22(1):126-135
Introduction: A reliable method of intradialysis calcium mass balance quantification is far from been established. We herein investigated the use of a single‐pool variable‐volume Calcium kinetic model to assess calcium mass balance in chronic and stable dialysis patients. Methods: Thirty‐four patients on thrice‐weekly HD were studied during 240 dialysis sessions. All patients were dialyzed with a nominal total calcium concentration of 1.50 mmol/L. The main assumption of the model is that the calcium distribution volume is equal to the extracellular volume during dialysis. This hypothesis is assumed valid if measured and predicted end dialysis plasma water ionized calcium concentrations are equal. A difference between predicted and measured end‐dialysis ionized plasma water calcium concentration is a deviation on our main hypothesis, meaning that a substantial amount of calcium is exchanged between the extracellular volume and a nonmodeled compartment. Findings: The difference between predicted and measured values was 0.02 mmol/L (range ?0.08:0.16 mmol/L). With a mean ionized dialysate calcium concentration of 1.25 mmol/L, calcium mass balance was on average negative (mean ± SD ?0.84 ± 1.33 mmol, range ?5.42:2.75). Predialysis ionized plasma water concentration and total ultrafiltrate were the most important predictors of calcium mass balance. A significant mobilization of calcium from the extracellular pool to a nonmodeled pool was calculated in a group of patients. Discussion: The proposed single pool variable‐volume Calcium kinetic model is adequate for prediction and quantification of intradialysis calcium mass balance, it can evaluate the eventual calcium transfer outside the extracellular pool in clinical practice. 相似文献
99.