851 research outputs found

    Stress-induced electron emission from nanocomposite amorphous carbon thin films

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    Traditionally, the emission of electrons from materials have been explained using either the Fowler-Nordheim emission mechanism where high electric fields are used to extract electrons from surfaces or using conventional thermal emission where high currents are used to 'boil' off electrons to vacuum. In this letter, we propose an alternative mechanism for electron emission from highly compressive thin films based on stress-induced 'band structure' modification of nano-ordered sp(2) regions in the thin films. Experimental results are recorded which show that the localized compressive stress governs electron emission in the amorphous carbon thin films studied here rather than the surface nanostructures/features or the diamond-like sp(3) hybridized bond component. This analysis is in agreement with the concept of an internal or nongeometric field enhancement from sp(2) nanostructures giving rise to high dielectric inhomogeneity within the carbon thin film. The results presented could be extended to explain the anomalous field emission behavior of carbon nanotubes. (C) 2002 American Institute of Physics.81585385

    Evaluation of students’ attitudes towards pharmacist–physician collaboration in Brazil

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    Objective. To measure undergraduate pharmacy and medical students’ collaborative attitudes regarding Pharmacist–Physician collaboration. Methods. A cross-sectional descriptive study was conducted from September 2016 to February 2017 in Northeast Brazil. Pharmacy and medical students from the first and the last year of courses were invited to complete Portuguese version of Scale of Attitudes Toward Pharmacist-Physician Collaboration (SATP2C). Descriptive and comparative analyses were performed using IBM SPSS (22 version). Differences were considered significant when p<0.05. Results. Three hundred seventy students completed the SATP2C. Overall, the students had positive attitudes towards physician-pharmacist collaboration. There was no significant correlation between age and score (p=0.79). Women showed a more positive collaborative attitude than men (53.1, SD=6.8 vs. 55.1, SD=6.3). Pharmacy students had a higher score than medical students (57.5, SD=4.7, vs. 51.1, SD=6.4). The first-year medical students had a higher score than last-year medical students (52.3, SD=6.0 vs. 49.5, SD=6.6; p<0.007). There was no significant difference in the attitudes between the first and last year pharmacy students (p<0.007). Conclusions. Pharmacy and medical students showed positive attitudes towards physician-pharmacist collaboration. However, pharmacy students presented more collaborative attitudes than medical ones. Additionally, the first-year medical students had more collaborative attitudes than last-year medical students. Studies should be conducted to provide recommendations to improve interprofessional education efforts to further enhance the positive attitudes toward physician-pharmacist collaboration

    Factors associated with the desire for orthodontic treatment among Brazilian adolescents and their parents

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    <p>Abstract</p> <p>Background</p> <p>In the period of adolescence physical appearance takes on significant importance in the construction of personal identity, including one's relationship with one's own body. A variety of social, cultural, psychological and personal factors influences the self-perception of dental appearance and the decision to undergo orthodontic treatment. Adolescents who seek orthodontic treatment are concerned with improving their appearance and social acceptance. The aim of the present study was to determine factors associated to the desire for orthodontic treatment among Brazilian adolescents and their parents.</p> <p>Methods</p> <p>The sample consisted of 403 subjects aged 14 to 18 years, selected randomly from a population of 182,291 schoolchildren in the same age group. The outcome variable "desire for orthodontic treatment" was assessed through a questionnaire. Self-perception of dental aesthetics was assessed using the Oral Aesthetic Subjective Impact Scale (OASIS) and the Dental Aesthetic Index (DAI) was used for clinical assessment. Statistical analysis involved the chi-square test as well as both simple and multiple logistic regression analyses.</p> <p>Results</p> <p>The majority (78%) of the Brazilian adolescents desired orthodontic treatment and 69% of the parents reported that their children were not in orthodontic treatment due to the high costs involved. There was significant association (p ≤ 0.05) between the desire for orthodontic treatment and most types of malocclusion. However, there was no significant association between the desire for orthodontic treatment and the variables gender and age.</p> <p>Conclusions</p> <p>The following were considered factors associated to the desire for treatment: upper anterior crowding ≥ 2 mm and parents' perception of their child's need for treatment.</p

    PAKs supplement improves immune status and body composition but not muscle strength in resistance trained individuals

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    Mixed formula supplements are very popular among recreational and professional weightlifters. They are usually known as PAKs and they are supposed to have a synergistic effect of their different nutrients. The purpose of this study was to determine the effects of chronic (4 weeks) PAKS supplementation in combination with strength training on body composition, immune status and performance measures in recreationally trained individuals with or without PAKs supplementation. Methods: Twelve male subjects (Placebo n = 6 and PAKs supplement n = 6) were recruited for this study. The body composition, one maximum strength repetition tests and immune status were assessed before and after 4 week supplementation. Our data showed that, 4 week PAK supplementation associated with strength exercise not was effective in change strength than compared with placebo group. However, we observed that, PAK supplement was able to improve immune status and reduced body composition when compared with placebo group. These results indicate that, a mixed formula supplement is able to improve immune status and body composition but not maximum strength in recreational strength trained subjects in a 4 weeks period

    The Role of Individual Variables, Organizational Variables and Moral Intensity Dimensions in Libyan Management Accountants’ Ethical Decision Making

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    This study investigates the association of a broad set of variables with the ethical decision making of management accountants in Libya. Adopting a cross-sectional methodology, a questionnaire including four different ethical scenarios was used to gather data from 229 participants. For each scenario, ethical decision making was examined in terms of the recognition, judgment and intention stages of Rest’s model. A significant relationship was found between ethical recognition and ethical judgment and also between ethical judgment and ethical intention, but ethical recognition did not significantly predict ethical intention—thus providing support for Rest’s model. Organizational variables, age and educational level yielded few significant results. The lack of significance for codes of ethics might reflect their relative lack of development in Libya, in which case Libyan companies should pay attention to their content and how they are supported, especially in the light of the under-development of the accounting profession in Libya. Few significant results were also found for gender, but where they were found, males showed more ethical characteristics than females. This unusual result reinforces the dangers of gender stereotyping in business. Personal moral philosophy and moral intensity dimensions were generally found to be significant predictors of the three stages of ethical decision making studied. One implication of this is to give more attention to ethics in accounting education, making the connections between accounting practice and (in Libya) Islam. Overall, this study not only adds to the available empirical evidence on factors affecting ethical decision making, notably examining three stages of Rest’s model, but also offers rare insights into the ethical views of practising management accountants and provides a benchmark for future studies of ethical decision making in Muslim majority countries and other parts of the developing world

    Identification and Behavioral Evaluation of Sex Pheromone Components of the Chinese Pine Caterpillar Moth, Dendrolimus tabulaeformis

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    Background: The Chinese pine caterpillar moth, Dendrolimus tabulaeformis Tsai and Liu (Lepidoptera: Lasiocampidae) is the most important defoliator of coniferous trees in northern China. Outbreaks occur over enormous areas and often lead to the death of forests during 2–3 successive years of defoliation. The sex pheromone of D. tabulaeformis was investigated to define its chemistry and behavioral activity. Methodology/Principal Findings: Sex pheromone was collected from calling female D. tabulaeformis by headspace solid phase microextraction (SPME) and by solvent extraction of pheromone glands. Extracts were analyzed by coupled gas chromatography/mass spectrometry (GC-MS) and coupled GC-electroantennographic detection (GC-EAD), using antennae from male moths. Five components from the extracts elicited antennal responses. These compounds were identified by a combination of retention indices, electron impact mass spectral matches, and derivatization as (Z)-5-dodecenyl acetate (Z5-12:OAc), (Z)-5-dodecenyl alcohol (Z5-12:OH), (5Z,7E)-5,7-dodecadien-1-yl acetate (Z5,E7-12:OAc), (5Z,7E)-5,7-dodecadien-1-yl propionate (Z5,E7-12:OPr), and (5Z,7E)-5,7-dodecadien-1-ol (Z5,E7-12:OH). Behavioral assays showed that male D. tabulaeformis strongly discriminated against incomplete and aberrant blend ratios. The correct ratio of Z5,E7-12:OAc, Z5,E7-12:OH, and Z5,E7-12:OPr was essential for optimal upwind flight and source contact. The two monoenes, Z5-12:OAc and Z5-12:OH, alone or binary mixtures, had no effect on behavioral responses when added to the optimal threecomponen
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