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11.
In recent years biodegradable polymers, particularly polyesters such as the poly(lactic acid) (PLA) and polycaprolactone (PCL), have gained high interests for their applicability in the biomedical and pharmaceutical fields where they're used for manufacturing various different resorbable devices, from tissue engineering scaffolds to controlled drug release systems. Despite many positive characteristics, processability of these materials still remains a critical issue as they easily tend to degrade during manufacturing. In this article we aimed to assess microextrusion as a nondegradative process for manufacturing PLA and PCL. The results we experimentally obtained, that are hereby presented, set a new point in the on‐going debate on degradation during processing of resorbable polymers as they allow to affirm that microextrusion leaves unmodified molecular weight distributions without producing any evident reductions in mean molecular weight. Microextrusion thus represents a risk‐free high molecular weight polymer processing solution for obtaining nondegraded products within pharmaceutical and biomedical production lines, such as for scaffolds for tissue engineering applications or drug delivery. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
12.
The effectiveness of a behavioral program to treat chronic aggression in an adult male individual diagnosed with schizophrenia at a public psychiatric hospital was evaluated. A behavioral plan was developed to provide the client with positive social interactions, social skills training, and positive reinforcement for prosocial behavior; no negative consequences were implemented. The number of aggressive acts declined with the introduction of the behavioral plan and ultimately remitted even without ongoing reinforcers. This article demonstrates the value of psychological intervention in treating aggression with a treatment-resistant client in an in-patient setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
A Daniele A Albanese G Gainotti B Gregori P Bartolomeo 《Canadian Metallurgical Quarterly》1997,349(9060):1222-1223
14.
Altschuh Daniele; Tessier Daniel C.; Vernet Thierry 《Protein engineering, design & selection : PEDS》1994,7(6):769-776
The two main catalytic residues Cys25 and Hisl59 of the monomericcysteine protease papain are located on different walls of acleft formed by two domains. This topology suggests a possiblerelationship between relative domain organization and catalyticmechanism. The effect on enzymatic parameters of structuralmodifications at various locations of the twodomain interfaceof papain was examined by individual or double replacementsby Ala of pairs of interacting residues. Most modificationshad no effect on enzyme activity. However, the enzyme's substrateturnover (kcat) decreased following simultaneous alterationof the two most conserved residues, forming an apolar contactlocated 15 Å away from the active site. The pH activityprofile of the double mutant was unchanged, indicating a conservedionization state of the active site thiolate-imidazolium ionpair. This state is strongly dependent on the distance separatingthe two residues, thus suggesting that the active site geometryhas not been significantly altered. Efficient enzymatic activityin papain requires more than a correct active site geometryand is influenced by domain packing properties in a region remotefrom the active site. 相似文献
15.
Grasso Susanna Claps Pierluigi Ganora Daniele Libertino Andrea 《Water Resources Management》2021,35(2):675-687
Water Resources Management - To reduce the impact of droughts and increase the resilience of regional water systems, various competing demands, such as hydropower, supply, irrigation and river... 相似文献
16.
Margaret Ottaviano Emilio Francesco Giunta Marianna Tortora Marcello Curvietto Laura Attademo Davide Bosso Cinzia Cardalesi Mario Rosanova Pietro De Placido Erica Pietroluongo Vittorio Riccio Brigitta Mucci Sara Parola Maria Grazia Vitale Giovannella Palmieri Bruno Daniele Ester Simeone 《International journal of molecular sciences》2021,22(7)
As widely acknowledged, 40–50% of all melanoma patients harbour an activating BRAF mutation (mostly BRAF V600E). The identification of the RAS–RAF–MEK–ERK (MAP kinase) signalling pathway and its targeting has represented a valuable milestone for the advanced and, more recently, for the completely resected stage III and IV melanoma therapy management. However, despite progress in BRAF-mutant melanoma treatment, the two different approaches approved so far for metastatic disease, immunotherapy and BRAF+MEK inhibitors, allow a 5-year survival of no more than 60%, and most patients relapse during treatment due to acquired mechanisms of resistance. Deep insight into BRAF gene biology is fundamental to describe the acquired resistance mechanisms (primary and secondary) and to understand the molecular pathways that are now being investigated in preclinical and clinical studies with the aim of improving outcomes in BRAF-mutant patients. 相似文献
17.
18.
Ethylene/propylene copolymers (EPM) have been prepared by a liquid propylene suspension process, using homogeneous catalysts based on nonbridged zirconocenes and methylaluminoxane (MAO). When bis(η5-cyclopentadienyl)zirconium dichloride (Cp2ZrCl2), bis(η5-cyclopentadienyl) dimethyl zirconium (Cp2ZrMe2) and bis(η5-cyclopentadienyl), dibenzyl zirconium (Cp2ZrBz2) were used as catalyst components, EPM having low average molecular weight (MW) were in general obtained in low yield. On the contrary, a very large improvement of productivity and MW was observed when bis(η5-indenyl)zirconium dichloride (Ind2ZrCl2) and bis(η5-indenyl) dimethyl zirconium (Ind2ZrMe2) as well as bis(η5-tetrahydroindenyl)zirconium dichloride [(IndH4)2ZrCI2] were employed in combination with MAO. In particular, this last catalytic system allowed one to obtain EPM with a narrower distribution of MW in addition to the above characteristics. Better performances, in terms of rheological and elastomeric properties, were also found for the crude and vulcanized samples prepared by (IndH4)2ZrCl2/MAO catalyst. 相似文献
19.
Olga Diamanti Amir Vaxman Daniele Panozzo Olga Sorkine‐Hornung 《Computer Graphics Forum》2014,33(5):1-11
We introduce N‐PolyVector fields, a generalization of N‐RoSy fields for which the vectors are neither necessarily orthogonal nor rotationally symmetric. We formally define a novel representation for N‐PolyVectors as the root sets of complex polynomials and analyze their topological and geometric properties. A smooth N‐PolyVector field can be efficiently generated by solving a sparse linear system without integer variables. We exploit the flexibility of N‐PolyVector fields to design conjugate vector fields, offering an intuitive tool to generate planar quadrilateral meshes. 相似文献
20.
Implementation of the quadrature method of moments in CFD codes for aggregation-breakage problems 总被引:1,自引:0,他引:1
Daniele L. Marchisio R. Dennis Vigil Rodney O. Fox 《Chemical engineering science》2003,58(15):3337-3351
In this work the quadrature method of moments (QMOM) is implemented in a commercial computational fluid dynamics (CFD) code (FLUENT) for modeling simultaneous aggregation and breakage. Turbulent and Brownian aggregation kernels are considered in combination with different breakage kernels (power law and exponential) and various daughter distribution functions (symmetric, erosion, uniform). CFD predictions are compared with experimental data taken from other work in the literature and conclusions about CPU time required for the simulations and the advantages of this approach are drawn. 相似文献