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41.
Nitroglycerin induces the so-called second window of protection (SWOP), which alleviates myocardial damage and stunning after ischaemia/reperfusion. To determine whether myocardial performance during exercise is improved in the second window of protection, we studied the haemodynamic responses of 12 trained and 11 sedentary individuals during a sequence of maximal tests on a cycle ergometer. A baseline test (basal test) was followed by a second effort performed during the second window of protection (exercise-SWOP test). Haemodynamics was also evaluated after pharmacologically induced SWOP 48 h after transdermal administration of 10 mg of nitroglycerin (pharmacologically induced SWOP test). The exercise-SWOP and pharmacologically induced SWOP tests were separated by a 1-week washout period. Endothelial-dependent vasodilatation after nitroglycerin pre-treatment was also assessed in five sedentary individuals to determine whether nitrate donors could affect vascular function. We found that nitroglycerin pre-treatment did not induce any improvement in haemodynamics in either trained or sedentary individuals, since maximum values of workload, heart rate, stroke volume, cardiac output, myocardial contractility, and double product were similar between the exercise-SWOP and pharmacologically induced SWOP tests in both groups. Furthermore, nitroglycerin pre-treatment did not alter flow-mediated dilation during pharmacologically induced SWOP. Although nitroglycerin pre-treatment alleviates post-ischaemic myocardial stunning, our results suggest that it does not affect the myocardial performance of healthy individuals during exercise performed in the second window of protection, independently of the training status of the individuals. Moreover, nitroglycerin pre-treatment does not ameliorate endothelial function.  相似文献   
42.
The present paper reports a new method for converting ettringite and thaumasite in non-expansible and insoluble phases, for its application in the restoration of concrete artefacts subjected to deterioration through sulphate attack. The salts were synthesized by different processes and, after characterization by means of XRD, FT-IR and optical microscopy, were treated with a series of chemicals in order to induce their decomposition. In particular, different solutions containing barium nitrate, barium hydroxide and ammonium oxalate were used to achieve the complete transformation of both phases in barite, witherite, scarbroite and whewellite. Barium hydroxide seemed to be the most appropriate reactant because the others could give rise to efflorescence within the pores of the mortars by leaving free nitrate or sulphate ions inside the materials. The experimental technique was also tested on two concrete samples collected from the bell-tower of St. Nicholas’ Cathedral in Nicosia (Sicily) with encouraging results.  相似文献   
43.
Neuroanatomy has been deemed crucial for clinical neurosciences. It has been one of the most challenging parts of the anatomical curriculum and is one of the causes of “neurophobia,” whose main implication is a negative influence on the choice of neurology in the near future. In the last decades, several educational strategies have been identified to improve the skills of students and to promote a deep learning. The aim of this study was to systematically review the literature to identify the most effective method/s to teach human neuroanatomy. The search was restricted to publications written in English language and to articles describing teaching tools in undergraduate medical courses from January 2006 through December 2017. The primary outcome was the observation of improvement of anatomical knowledge in undergraduate medical students. Secondary outcomes were the amelioration of long-term retention knowledge and the grade of satisfaction of students. Among 18 selected studies, 44.4% have used three-dimensional (3D) teaching tools, 16.6% near peer teaching tool, 5.55% flipped classroom tool, 5.55% applied neuroanatomy elective course, 5.55% equivalence-based instruction-rote learning, 5.55% mobile augmented reality, 5.55% inquiry-based clinical case, 5.55% cadaver dissection, and 5.55% Twitter. The high in-between study heterogeneity was the main issue to identify the most helpful teaching tool to improve neuroanatomical knowledge among medical students. Data from this study suggest that a combination of multiple pedagogical resources seems to be the more advantageous for teaching neuroanatomy.  相似文献   
44.
This study investigated the unique and common contributions of four sets of predictor variables: (1) background, (2) mental ability, (3) program, and (4) parental involvement, to the variance in reading achievement scores—vocabulary and comprehension—for Title I students enrolled in Rhode Island remedial reading programs. The vocabulary analysis indicated that the four sets accounted uniquely for 7, 13, 9, and 9% of the variance, respectively. The comprehension analysis indicated that the four sets accounted for 7, 25, 5, and 4% of the variance, respectively. Joint contributions are also presented.  相似文献   
45.
This paper explores the organisation and codification of knowledge in software firms. It analyses various economic incentives to codification, including the need to improve the productivity and quality of software production and the networks of inter-firm alliances.The paper examines the experience of five Italian software firms specialising in software packages and services. It compares their capabilities, main sources of tacit knowledge, specific incentives to invest in knowledge codification and the formal development methodologies and quality control systems adopted. Finally, the paper analyses two distinct technological collaborations that two of these firms have recently established.  相似文献   
46.
This study investigates how much the racial composition of communities influences the private school enrollment rates of members of different racial groups. Some scholars argue that private school enrollment contributes to racial segregation in public schools because White families attempt to enhance the social status of their children by leaving public schools serving communities with higher percentages of children who are Black. A second group of scholars argue that private school enrollment is primarily based on nonracial factors. A third, related perspective argues that race is of diminishing importance in driving behaviors such as school choice. This study explores these perspectives using 1990 and 2000 Public Use Micro Data Samples to estimate private school enrollment rates by student race and community racial composition. Findings indicate that private school enrollment rates among Asian, Black, and Hispanic students do not fluctuate much with community racial composition. By contrast, private school enrollment rates among White families are strongly and positively correlated with the percentage of children in their communities who are Black—even after holding constant a series of individual and community-level factors that may account for this trend. Moreover, the association between race and choice has changed little between 1990 and 2000.  相似文献   
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48.
The utilization of laser light to produce fine and selective cleaning of superficial deposits and encrustation from stones was originally proposed more than 20 years ago by John Asmus who performed pioneering trials of laser cleaning on stone façades in Venice, Cremona and Padua. The opportunity to collect stone samples from these sites allowed us to carry out an original study aimed at evaluating the conservation state of stone surfaces cleaned 10–20 years ago by means of three different techniques: Nd:YAG laser radiation, micron sandblasting and chemical pads. Samples of various stone types, as Istria limestone, Botticino limestone and Nanto sandstone were collected and examined by means of optical and SEM microscopy, FT/IR, and EDAX analyses. The results provided preliminary indications that the state of conservation of stone surfaces previously subjected to laser cleaning is generally better in comparison with those which concurrently underwent mechanical and chemical cleaning.  相似文献   
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50.
Collaborative and co-located information access is becoming increasingly common. However, fairly little attention has been devoted to the design of ubiquitous computing approaches for spontaneous exploration of large information spaces enabling co-located collaboration. We investigate whether an entity-based user interface provides a solution to support co-located search on heterogeneous devices. We present the design and implementation of QueryTogether, a multi-device collaborative search tool through which entities such as people, documents, and keywords can be used to compose queries that can be shared to a public screen or specific users with easy touch enabled interaction. We conducted mixed-methods user experiments with twenty seven participants (nine groups of three people), to compare the collaborative search with QueryTogether to a baseline adopting established search and collaboration interfaces. Results show that QueryTogether led to more balanced contribution and search engagement. While the overall s-recall in search was similar, in the QueryTogether condition participants found most of the relevant results earlier in the tasks, and for more than half of the queries avoided text entry by manipulating recommended entities. The video analysis demonstrated a more consistent common ground through increased attention to the common screen, and more transitions between collaboration styles. Therefore, this provided a better fit for the spontaneity of ubiquitous scenarios. QueryTogether and the corresponding study demonstrate the importance of entity based interfaces to improve collaboration by facilitating balanced participation, flexibility of collaboration styles and social processing of search entities across conversation and devices. The findings promote a vision of collaborative search support in spontaneous and ubiquitous multi-device settings, and better linking of conversation objects to searchable entities.  相似文献   
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