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排序方式: 共有82条查询结果,搜索用时 15 毫秒
1.
Danila Gasperini Lorenzo Maggi Stphanie Dupuy Richard M. P. Veenboer David B. Cordes Alexandra M. Z. Slawin Steven P. Nolan 《Advanced Synthesis \u0026amp; Catalysis》2016,358(23):3857-3862
The improved synthesis of γ‐, δ‐ and ϵ‐lactones using a dinuclear N‐heterocyclic carbene (NHC)‐gold(I) catalyst is reported. This solvent‐free process provides access to γ‐ and δ‐lactones in high regio‐ and stereoselectivity. Reactions were performed at low catalyst loadings and without the need for any additives. The use of a digold pre‐catalyst provides a new synthetic route to functionalised ϵ‐lactones, poorly accessible using previous methodologies.
2.
Giuseppe Espa Danila Filipponi Diego Giuliani Davide Piacentino 《Papers in Regional Science》2014,93(Z1):S113-S135
In this paper, spatial shift‐share decomposition is analysed when applied to Italian data on regional business change at plant level, over the period 2004–2009. A new type of spatial decomposition, which looks more effectively at neighbourhood influence, is introduced here. Notable results emerge from the empirical investigation. First, it can be seen that the spatial level of aggregation greatly affects results. Second, evidence of neighbourhood advantage in the Southern NUTS 3 regions is found, together with opposite results for the Central‐Northern NUTS 3 regions. Finally, evidence of positive industrial mix effects is only found in Central‐Northern Italy. 相似文献
3.
S. Viscuso S. Pittaccio M. Caimmi G. Gasperini S. Pirovano E. Villa S. Besseghini F. Molteni 《Journal of Materials Engineering and Performance》2009,18(5-6):805-813
A compliant brace (EDGES) promoting spastic elbow relaxation was designed to investigate the potentialities of pseudoelastic NiTi in orthotics. By exploiting its peculiar characteristics, EDGES could improve elbow posture without constraining movements and thus avoiding any pain to the patient. A commercial Ni50.7-Ti49.3 alloy heat treated at 400 °C 1 h + WQ was selected for this application. A prototype of EDGES was assembled with two thermoplastic shells connected by polycentric hinges. Four 2-mm-diameter NiTi bars were encastred in the upper-arm shell and let slide along tubular fixtures on the forearm. Specially designed bending tests demonstrated suitable moment-angle characteristics. Two post-stroke subjects (aged 62 and 64, mild elbow flexors spasticity) wore EDGES for 1 week, at least 10 h a day. No additional treatment was applied during this period or the following week. A great improvement (20° ± 5°) of the resting position was observed in both patients as early as 3 h after starting the treatment. Acceptability was very good. A slight decrease in spasticity was also observed in both subjects. All the effects disappeared 1 week after discontinuation. EDGES appears to be a good alternative to traditional orthoses in terms of acceptability and effectiveness in improving posture, especially whenever short-term splinting is planned. 相似文献
4.
Gianmaria Gasperini Elena Fusari Laura Della Bella Paolo Bondioli 《European Journal of Lipid Science and Technology》2007,109(7):673-681
In this paper, a technique useful for the classification of different food oil co‐ and by‐products of potential use for feed preparation is shown. The proposal is based upon a Fourier transform infrared evaluation of different classes of compounds, and its elaboration was carried out starting from the knowledge of the chemical composition of each feedstock category. Using this technique, a sure classification of fatty acid calcium soaps, fully hydrogenated fatty acids, lecithins, acid oils from chemical refining, acid oils from physical refining and fish oils can be easily done. The remaining categories of animal fats, fried oils and oils recovered from exhausted bleaching earth can be differentiated by using one or two additional chemical tests. The scope of this paper is to provide a quick, easy and non‐expensive tool for a correct classification of feedstock, in order to allow the choice of correct and applicable analytical tests for the evaluation of the quality and of the composition of each sample. 相似文献
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6.
The “antioxidant power” of a food is an expression of its capability both to defend the human organism from the action of the free radicals and to prevent degenerative disorders deriving from persistent oxidative stress. Purpose of this study is to analyse the antioxidant capacity (measured by means of the crocin bleaching method) of several samples of Sicilian red wines and to evaluate their dependency on the vintage and on the grape variety. Finally, the correlation between the single flavonoids compounds and the antioxidant capacity has been investigated. The analyses show that the antioxidant properties of red wine appear to be unequally influenced by the vintages for the different cultivars and that the correlation between antioxidant capacity and the total phenolic contents is weak. The latter can be explained by the fact that the wine’s antioxidant properties are influenced differently by each polyphenolic molecule. 相似文献
7.
Elisa Tripoli Maurizio La GuardiaSanto Giammanco Danila Di MajoMarco Giammanco 《Food chemistry》2007,104(2):466-479
Epidemiological studies have shown an inverse relationship between dietary flavonoid intakes and cardiovascular diseases. Citrus fruits are the main winter fruits consumed in the Mediterranean diet, so they are the main source of dietary flavonoids. The possible beneficial effects are due, not only to the high amounts of vitamins and minerals, but also to the antioxidant properties of their flavonoids. Dietary flavonoids may help to supplement the body antioxidant defences against free radicals. These compounds’ possible beneficial effects are due to their antioxidant activity, which is related to the development of atherosclerosis and cancer, and to anti-inflammatory and antimicrobial activity. The present review summarizes the existing bibliography on biological and pharmacological studies of Citrus flavonoids, both in vitro and in vivo. 相似文献
8.
Vanessa Arato Maria Michelina Raso Gianmarco Gasperini Francesco Berlanda Scorza Francesca Micoli 《International journal of molecular sciences》2021,22(8)
Klebsiella pneumoniae (Kp) is an opportunistic pathogen and the leading cause of healthcare-associated infections, mostly affecting subjects with compromised immune systems or suffering from concurrent bacterial infections. However, the dramatic increase in hypervirulent strains and the emergence of new multidrug-resistant clones resulted in Kp occurrence among previously healthy people and in increased morbidity and mortality, including neonatal sepsis and death across low- and middle-income countries. As a consequence, carbapenem-resistant and extended spectrum β-lactamase-producing Kp have been prioritized as a critical anti-microbial resistance threat by the World Health Organization and this has renewed the interest of the scientific community in developing a vaccine as well as treatments alternative to the now ineffective antibiotics. Capsule polysaccharide is the most important virulence factor of Kp and plays major roles in the pathogenesis but its high variability (more than 100 different types have been reported) makes the identification of a universal treatment or prevention strategy very challenging. However, less variable virulence factors such as the O-Antigen, outer membrane proteins as fimbriae and siderophores might also be key players in the fight against Kp infections. Here, we review elements of the current status of the epidemiology and the molecular pathogenesis of Kp and explore specific bacterial antigens as potential targets for both prophylactic and therapeutic solutions. 相似文献
9.
10.
Sulfolobus solfataricus protein disulphide oxidoreductase: insight into the roles of its redox sites
Limauro D Saviano M Galdi I Rossi M Bartolucci S Pedone E 《Protein engineering, design & selection : PEDS》2009,22(1):19-26
Sulfolobus solfataricus protein disulphide oxidoreductase (SsPDO)contains three disulphide bridges linking residues C41XXC44,C155XXC158, C173XXXXC178. To get information on the role playedby these cross-links in determining the structural and functionalproperties of the protein, we performed site-directed mutagenesison Cys residues and investigated the changes in folding, stabilityand functional features of the mutants and analysed the resultswith computational analysis. The reductase activity of SsPDOand its mutants was evaluated by insulin and thioredoxin reductaseassays also coupled with peroxiredoxin Bcp1 of S. solfataricus.The three-dimensional model of SsPDO was constructed and correlatedwith circular dichroism data and functional results. Biochemicalanalysis indicated a key function for the redox site constitutedby Cys155 and Cys158. To discriminate between the role of thetwo cysteine residues, each cysteine was mutagenised and thebehaviour of the single mutants was investigated elucidatingthe basis of the electron-shuffling mechanism for SsPDO. Finally,cysteine pK values were calculated and the accessible surfacefor the cysteine side chains in the reduced form was measured,showing higher reactivity and solvent exposure for Cys155. 相似文献