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121.
Metacognition, or ′thinking about thinking′, can improve scientific literacy and practices. It involves knowledge of cognition, i. e., being cognisant of one‘s knowledge, and regulation of cognition, i. e., consciously controlling the process of knowledge acquisition. A self‐regulated learner can assimilate new knowledge, conduct inquiry, solve problems and plan ahead his or her learning. While studies have been conducted on metacognition in chemistry education, none have included detailed assignments covering a range of metacognitive strategies. Our review of studies on metacognition in chemistry secondary and higher education also includes also several exemplary assignments on the energy topic for facilitating and assessing metacognition in high school classrooms. We use metacognitive prompts and the construct of chemistry understanding levels, macroscopic, microscopic, symbol, and process, as an approach for metacognitive intervention. Finally, we provide recommendations for educators and a rubric for researchers.  相似文献   
122.
The antiradical activity of water soluble components in six vegetables belonging to the Cichorium genus, i.e., three cultivars of red intybus species var. silvestre (Treviso, Chioggia, Verona red chicories), a white intybus species var. foliosum (Belgian chicory), and two vegetables of the endivia species var. latifolium (escarole chicory) and var. crispum (“crispa” chicory), were studied using two biological systems consisting of: (1) microsome membrane rat hepatocyties in which oxidative damage was induced by CCl4; (2) gram-positive bacterium, Staphylococcus aureus cultures, subjected to damage with cumene hydroperoxyde. The obtained results show that in both systems the red vegetables possess the strongest antioxidant properties and contain different antioxidant compounds whether at a low or high molecular weight, but only those of high molecular-weight (MW > 3500 Da) are able to act as antioxidants in all the used systems. The lower MW fraction (MW < 3500 Da) showed itself to be pro-oxidant in the microsome system. The effects of thermal treatments such as boiling, freezing and freeze-drying were also investigated.  相似文献   
123.
124.
Bacteria-hemocyte interactions and phagocytosis in marine bivalves   总被引:7,自引:0,他引:7  
Marine bivalves (such as mussels, oysters, and clams) are widespread mollusks in coastal waters at different latitudes; due to their filter-feeding habits, they accumulate large numbers of bacteria from the harvesting waters and may act as passive carriers of human pathogens. To cope with this challenge, bivalves possess both humoral and cellular defense mechanisms with remarkably effective capabilities. The circulating cells, or hemocytes, are primarily responsible for defense against parasites and pathogens; microbial killing results from the combined action of the phagocytic process with humoral defense factors such as agglutinins (e.g., lectins), lysosomal enzymes (e.g., acid phosphatase, lysozyme), toxic oxygen intermediates, and various antimicrobial peptides. In this work, current knowledge of the mechanisms underlying the interactions between bacteria and the hemolymph components of marine bivalves is summarized. Bacterial susceptibility to hemolymph killing in different bivalve species may be a consequence of the different ability of bacterial products to attract phagocytes, the presence or absence of specific opsonizing molecules, the hemocyte capability to bind and engulf different bacteria, and the different bacterial sensitivity to intracellular killing. The role of soluble (e.g., agglutinins and opsonins) and surface-bound factors in bacterial phagocytosis by hemocytes of the most common marine bivalve species is described and the possibility that environmental temperatures and other seasonal factors may influence this process is considered. Moreover, the potential strategies used by bacteria to evade phagocytic killing by hemocytes are discussed. From the available data it is clear that several questions need further investigation; the elucidation of the factors influencing phagocytosis in bivalves and the fundamental strategies used by bacteria to escape hemolymph killing are important not only to understand bivalve immune defenses but also to explain the persistence of pathogenic bacteria in bivalve tissues and to predict the consequent impact on human health.  相似文献   
125.
In the last decades, an increasing number of employers and job seekers have been relying on Web resources to get in touch and to find a job. If appropriately retrieved and analyzed, the huge number of job vacancies available today on on-line job portals can provide detailed and valuable information about the Web Labor Market dynamics and trends. In particular, this information can be useful to all actors, public and private, who play a role in the European Labor Market. This paper presents WoLMIS, a system aimed at collecting and automatically classifying multilingual Web job vacancies with respect to a standard taxonomy of occupations. The proposed system has been developed for the Cedefop European agency, which supports the development of European Vocational Education and Training (VET) policies and contributes to their implementation. In particular, WoLMIS allows analysts and Labor Market specialists to make sense of Labor Market dynamics and trends of several countries in Europe, by overcoming linguistic boundaries across national borders. A detailed experimental evaluation analysis is also provided for a set of about 2 million job vacancies, collected from a set of UK and Irish Web job sites from June to September 2015.  相似文献   
126.
The Social Web is characterized by a massive diffusion of unfiltered content, directly generated by users via the spread of different social media platforms. In this context, a challenging issue is to assess the veracity of the information generated within the sites of online reviews. To address this issue, a common practice in the literature is to select and analyze some veracity features associated with users and their reviews, by mostly applying machine learning techniques, to provide a classification in genuine and deceptive reviews. In this paper, we do not focus on the feature selection and user behavior analysis issues, but we concentrate on the aggregation process with respect to each single veracity feature. In most of the approaches based on machine learning techniques, the contribution of each feature in the classification process is not measurable by the user. For this reason, we propose a multicriteria decision making approach based both on the assessment of multiple criteria and the use of aggregation operators with the aim of obtaining a veracity score associated with each review. Based on this score, it is possible to detect fake reviews. The proposed model is evaluated on a Yelp data set by applying different aggregation schemes, and it is compared with well‐known supervised machine learning techniques.  相似文献   
127.
Ocular drug delivery formulations must meet anatomical, biopharmaceutical, patient-driven and regulatory requirements. Mucoadhesive polymers can serve as a better alternative to currently available ophthalmic formulations by providing improved bioavailability. If all requirements are addressed, a polymeric formulation resembling the tear film of the eye might be the best solution. The optimum formulation must not have high osmotic activity, should provide appropriate surface tension, pH and refractive index, must be non-toxic and should be transparent and mucoadhesive. We would like to highlight the importance of in vitro polymer testing from a pharmaceutical aspect. We, therefore, carried out physical–chemical investigations to verify the suitability of certain systems for ophthalmic formulations. In this work, in situ gelling, mucoadhesive thiolated poly(aspartic acid)s were tested from ophthalmic formulation aspects. The results of preformulation measurements indicate that these polymers can be used as potential carriers in ophthalmic drug delivery.  相似文献   
128.
In this paper we study AGM contraction and revision of rules using input/output logical theories. We replace propositional formulas in the AGM framework of theory change by pairs of propositional formulas, representing the rule based character of theories, and we replace the classical consequence operator Cn by an input/output logic. The results in this paper suggest that, in general, results from belief base dynamics can be transferred to rule base dynamics, but that a similar transfer of AGM theory change to rule change is much more problematic. First, we generalise belief base contraction to rule base contraction, and show that two representation results of Hansson still hold for rule base contraction. Second, we show that the six so-called basic postulates of AGM contraction are consistent only for some input/output logics, but not for others. In particular, we show that the notorious recovery postulate can be satisfied only by basic output, but not by simple-minded output. Third, we show how AGM rule revision can be defined in terms of AGM rule contraction using the Levi identity. We highlight various topics for further research.  相似文献   
129.
Amine-oxide surfactants have emerged as highly stable, nontoxic, and cost-effective constituents of detergent formulations, specifically as wetting agents and foam boosters. With the aim of enhancing their functional behavior, a new member of this family, N,N-dimethyl-2-propylheptan-1-amine oxide, bearing a branched alkyl tail (C10DAO-branched) was synthesized and purified using a simple and easily scalable strategy starting from 2-propylheptan-1-ol. 2D-nuclear magnetic resonance (NMR) and mass spectrometry confirm the obtainment of the desired product in high yield and purity. The protonation behavior of the branched surfactant is not affected by alkyl tail branching, as shown by potentiometric titrations. In contrast, surface activity and aggregation behavior of C10DAO-branched is dramatically different from that of the linear analog N,N-dimethyldecyl-1-amine oxide (C10DAO-linear), in that it occupies a higher area at the solution interface and aggregates at much higher concentration, forming larger aggregates, as detected using tensiometry and dynamic light scattering (DLS), respectively. Aggregation behavior of C10DAO-branched is less sensitive to pH variations. Foaming tests show that C10DAO-branched is a more effective foam booster than its linear analog, in both acidic and basic solutions. The experimental results indicate that the branched surfactant can be used in applications that require enhanced and pH-independent surface activity and foamability.  相似文献   
130.
A synthetic poly(amino acid), poly(aspartic acid) modified with thioethyl side groups, was studied as an in situ gelling and mucoadhesive dosage form. The chemical structure and the controllable, large thiol content of the polymer were confirmed using 1H NMR spectroscopy and Ellman's assay. In situ gelation of aqueous polymer solutions was induced by oxidation and monitored using oscillation rheometry. The strength of mucoadhesion towards excised mucosa was characterised by tensile tests in ex vivo experiments. Release kinetics of ophthalmic antibiotic ofloxacin was studied from an in situ crosslinked hydrogel and a liquid formulation to prove the sustained release of the former. © 2017 Society of Chemical Industry  相似文献   
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