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排序方式: 共有2047条查询结果,搜索用时 15 毫秒
71.
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
72.
Francesca Soglia Massimiliano Petracci Samer Mudalal Lucia Vannini Giorgia Gozzi Lucia Camprini Claudio Cavani 《International Journal of Food Science & Technology》2014,49(10):2184-2191
This study was aimed at evaluating the consequences of sodium chloride reduction by potassium chloride up to 50% on technological, sensorial and microbiological traits of marinated rabbit meat. In total, 226 rabbit loin meat samples were obtained and subjected to vacuum tumbling using solutions with different NaCl/KCl ratios. Replacing of sodium chloride up to 30% by potassium chloride did not change microbiological traits (total aerobic mesophilic and lactic acid bacteria maximum cell loads), sensorial acceptability (perceived saltiness and overall liking) and technological traits (pH, colour, texture, cooking loss and yield). Otherwise, reduction in sodium chloride to 50% significantly decreased perceived saltiness (4.15 vs. 4.73; P < 0.05) and reduced microbial shelf life by 1 day when compared to control, even if there was still no effect on technological traits. In conclusion, it is feasible imparting an added value for processed rabbit meat products by reduction in sodium content that could increase market interest. 相似文献
73.
The vision of Organic Computing addresses challenges that arise in the design of future information systems that are comprised of numerous, heterogeneous, resource-constrained and error-prone components. The notion organic highlights the idea that, in order to be manageable, such systems should exhibit self-organization, self-adaptation and self-healing characteristics similar to those of biological systems. In recent years, the principles underlying these characteristics are increasingly being investigated from the perspective of complex systems science, particularly using the conceptual framework of statistical physics and statistical mechanics. In this article, we review some of the interesting relations between statistical physics and networked systems and discuss applications in the engineering of organic overlay networks with predictable macroscopic properties. 相似文献
74.
Luca Giorleo Claudio Giardini Elisabetta Ceretti 《International Journal of Material Forming》2013,6(1):145-152
Ring rolling is a hot forming process used in the production of railway tyres, anti friction bearing races and different ring shaped work pieces for automotive energy production and aerospace applications. The advantages of ring rolling process include short production time, uniform quality, closed tolerances, good material quality and considerable saving in material cost. Despite the benefits some problems still exist according to a correct selection of the process parameters. Due to the nature of the process different rolling mills (driving, idle and axial rolls) are involved and the correct selection of the process parameters is not so feasible. Moreover an experimental approach to solve this problem risks to be more expensive. Actually FE codes are available to simulate the non linear problem that characterizes a ring rolling process. In this work a FE model, based on Deform 3D software, was tested versus experimental results acquired from an industrial plant. The accuracy of the FE model was analyzed through a dual comparison: by geometrical and by physical aspects. A good agreement was found between experimental and numerical results for both comparisons and, as a consequence, this code could be used in order to investigate and optimize the process parameters that characterize the ring rolling process in a virtual not expensive environment. The validated model will allow the studies of more environment-friend process configurations. 相似文献
75.
Hemodialysis treatment is biased by complications during its operative phases. One of these potential accidents consists in intradialytic hypotension, that causes discomfort to the patient and may even increase the risk of death. Therefore, it is very important to predict these events in routine clinical procedures. A cause of hypotension may be thermal energy/heat exchanges between extracorporeal system and the surrounding environment. A model to evaluate these heat losses is proposed and improved in order to maintain constant patient blood temperature. A convenient procedure is defined to improve and optimize clinical treatment. Although most hemodialysis machines automatically control the dialysate solution temperature starting from peripheral body temperature measurements, the proposed method is based on the control of the pre-dialysis core temperature of the patient, and the temperature of the blood entering the artery from the extracorporeal circuit after the treatment in the dialyzer. Measurements of arterial and venous blood temperatures are obtained in a non invasive way by a suitable estimate of the thermal energy exchanges between the blood and the environment during the extracorporeal recirculation. The suggested model guarantees a constant core temperature of the patient, improving prevention from intradialytic hypotension. 相似文献
76.
The domain of cancer treatment is a promising field for the implementation and evaluation of a protocol-based clinical decision support system, because of the algorithmic nature of treatment recommendations. However, many factors can limit such systems’ potential to support the decision of clinicians: technical challenges related to the interoperability with existing electronic patient records and clinical challenges related to the inherent complexity of the decisions, often collectively taken by panels of different specialists. In this paper, we evaluate the performances of an Asbru-based decision support system implementing treatment protocols for breast cancer, which accesses data from an oncological electronic patient record. Focusing on the decision on the adjuvant pharmaceutical treatment for patients affected by early invasive breast cancer, we evaluate the matching of the system's recommendations with those issued by the multidisciplinary panel held weekly in a hospital. 相似文献
77.
Valentina Aina Gianluca Malavasi Claudio Magistris Giuseppina Cerrato Gianmario Martra Guido Viscardi Ledi Menabue Gigliola Lusvardi 《Journal of materials science. Materials in medicine》2014,25(10):2243-2253
Bioceramics, such as silica-based glasses, are widely used in bone and teeth restoration. Nowadays, the association between nanotechnology and pharmacology is one of the most promising research fields in cancer therapy. The advanced processing methods and new chemical strategies allow the incorporation of drugs within them or on their functionalized surfaces. Bioceramics can act as local drug delivery systems to treat bone and teeth diseases. The present paper reports data related to the development of a pH-stimuli responsive bioactive glass. The glass conjugation with 5-aminofluorescein (5-AF), through a pH-sensitive organic spacer, allows to produce a pH-responsive bioactive biomaterial: when it is exposed to specific pH changes, it can favour the release of 5-AF directly at the target site. 5-AF has been chosen as a simple, low cost, non toxic model to simulate doxorubicin, an anticancer drug. As doxorubicin, 5-AF contains an amino group in its structure in order to form an amide bond with the carboxylic functionalities of the glass. Raman spectroscopy and thermal analysis confirm the glass conjugation of 5-AF by means of an amide bond; the amount of 5-AF loaded was very high (≈65 and 44 wt%). The release tests at two different pH (4.2 and 7.4) show that the amount of released 5-AF is higher at acid pH with respect to physiological one. This preliminary datum evidenced that a pH-sensitive drug delivery system has been developed. The low amount of 5-AF released (<1 wt% of the total 5-AF) is due to the very low solubility of 5-AF in aqueous medium. This disadvantage, may be overcome in a dynamic environment (physiological conditions), where it is possible to obtain a drug release system ensuring an effective therapeutic dose for long times and, at the same time, avoiding the drug toxicity. 相似文献
78.
Sorption of propylene and propane in polyurethane membranes containing silver nanoparticles 下载免费PDF全文
Carolina Guedes Fioravante Rezende Cristiano Piacsek Borges Alberto Claudio Habert 《应用聚合物科学杂志》2016,133(4)
The preparation of a facilitated transport membrane of polyurethane (PU) containing silver nanoparticles is reported. The propylene and propane sorption was investigated aiming at the selective separation from C3s mixtures. The silver particles were photogenerated in situ into the polyurethane matrix using UV light radiation and silver triflate (AgCF3SO3) as precursor. The morphological properties of these membranes (PUAg) reveled great dispersion of silver particles, which size was smaller than 110 nm. The propylene solubility in PUAg resulted more than four times superior to the one for the pure PU membrane, revealing the high affinity between silver and propylene. Flory–Huggins theory was more accurate to describe the propylene sorption behavior in PUAg than Henry's model. The ideal solubility selectivity of PUAg membrane resulted 24.4, indicating that there is a good potential for an industrial application aiming at the separation of propylene/propane. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42916. 相似文献
79.
Romina Fernández Varela Dr. Ana Laura Valino Dr. Eman Abdelraheem Dr. Rosario Médici Dr. Melisa Sayé Dr. Claudio A. Pereira Dr. Peter-Leon Hagedoorn Prof. Ulf Hanefeld Prof. Adolfo Iribarren Prof. Elizabeth Lewkowicz 《Chembiochem : a European journal of chemical biology》2022,23(13):e202200147
In nature 2-deoxy-D-ribose-5-phosphate aldolase (DERA) catalyses the reversible formation of 2-deoxyribose 5-phosphate from D-glyceraldehyde 3-phosphate and acetaldehyde. In addition, this enzyme can use acetaldehyde as the sole substrate, resulting in a tandem aldol reaction, yielding 2,4,6-trideoxy-D-erythro-hexapyranose, which spontaneously cyclizes. This reaction is very useful for the synthesis of the side chain of statin-type drugs used to decrease cholesterol levels in blood. One of the main challenges in the use of DERA in industrial processes, where high substrate loads are needed to achieve the desired productivity, is its inactivation by high acetaldehyde concentration. In this work, the utility of different variants of Pectobacterium atrosepticum DERA (PaDERA) as whole cell biocatalysts to synthesize 2-deoxyribose 5-phosphate and 2,4,6-trideoxy-D-erythro-hexapyranose was analysed. Under optimized conditions, E. coli BL21 (PaDERA C-His AA C49M) whole cells yields 99 % of both products. Furthermore, this enzyme is able to tolerate 500 mM acetaldehyde in a whole-cell experiment which makes it suitable for industrial applications. 相似文献
80.
Chayene G. Anchieta Daniela Sallet Edson L. Foletto Syllos S. da Silva Osvaldo Chiavone-Filho Claudio A.O. do Nascimento 《Ceramics International》2014
Ternary zinc spinel oxides such as Zn2SnO4, ZnAl2O4 and ZnFe2O4 were synthesized and characterized, and their activities in the photodegradation of phenol molecules were investigated. Zn2SnO4, ZnAl2O4 and ZnFe2O4 powders were synthesized by hydrothermal, metal–chitosan complexation and solvothermal routes, respectively. The face-centered cubic spinel structure of each material was confirmed by powder X-ray diffractometry (XRD) and its porous structure by N2 adsorption–desorption isotherms. The characterization of spinels was complemented with Fourier transform infrared spectroscopy (FTIR) and X-rays fluorescence (XRF), revealing the formation of spinel structures with high purity. The photocatalytic activity in the degradation of phenol was observed only with Zn2SnO4 oxide. Mineralization degree of phenol molecules by Zn2SnO4 photocatalyst determined by total organic carbon analysis (TOC) reached 80% at 360 min under sunlight. 相似文献