bluuebunny/crossref_metadata_2025 huggingface dataset:
Vampire Venom: Vasodilatory Mechanisms of Vampire Bat (Desmodus rotundus) Blood Feeding
Authors: Kakumanu Rahini , Hodgson Wayne C. , Ravi Ravina , Alagon Alejandro , Harris Richard J. , Brust Andreas , Alewood Paul F. , Kemp-Harper Barbara K. , Fry Bryan G.
Published: January 2019

Animals that specialise in blood feeding have particular challenges in obtaining their meal, whereby they impair blood hemostasis by promoting anticoagulation and vasodilation in order to facilitate feeding. These convergent selection pressures have been studied in a number of lineages, ranging from fleas to leeches. However, the vampire bat (Desmondus rotundus) is unstudied in regards to potential vasodilatory mechanisms of their feeding secretions (which are a type of venom). This is despite the intense investigations of their anticoagulant properties which have demonstrated that D. rotundus venom contains strong anticoagulant and proteolytic activities which delay the formation of blood clots and interfere with the blood coagulation cascade. In this study, we identified and tested a compound from D. rotundus venom that is similar in size and amino acid sequence to human calcitonin gene-related peptide (CGRP) which has potent vasodilatory properties. We found that the vampire bat-derived form of CGRP (i.e., vCGRP) selectively caused endothelium-independent relaxation of pre-contracted rat small mesenteric arteries. The vasorelaxant efficacy and potency of vCGRP were similar to that of CGRP, in activating CGRP receptors and Kv channels to relax arteriole smooth muscle, which would facilitate blood meal feeding by promoting continual blood flow. Our results provide, for the first time, a detailed investigation into the identification and function of a vasodilatory peptide found in D. rotundus venom, which provides a basis in understanding the convergent pathways and selectivity of hematophagous venoms. These unique peptides also show excellent drug design and development potential, thus highlighting the social and economic value of venomous animals.
The Role of Routine Culture in the Treatment of Chronic Suppurative Otitis Media: Implications for the Standard of Care in Rural Areas of South Africa
Authors: Toman Julia , Moll Anthony , Barnes Melynda , Shenoi Sheela , Porterfield J. Zachary
Published: January 2019

Chronic Suppurative Otitis Media (CSOM) is a widely prevalent disease, which is a leading cause of acquired deafness worldwide, and is associated with complications with significant mortality and morbidity. It often responds poorly to standard of care therapy and places a disproportionate burden on at-risk populations. The microbiology and antibiotic resistance of CSOM varies based on local factors, including health care access, comorbidities, and antibiotic prescribing practices. We evaluated the role and feasibility of using routine culture for the treatment of CSOM in rural areas as a means of improving treatment of CSOM. More than 400 patients were screened in a rural clinic in South Africa over six weeks, and 14 met study criteria and consented for participation. Gram-negative organisms predominated overall, although Staphylococcus aureus was the most commonly isolated single species. A majority of the pathogens were relatively sensitive to commonly prescribed antibiotics, but two cases of methicillin resistant Staphylococcus aureus were cultured, and one patient grew a Scedosporium species. Treatment on follow-up was able to be directed by culture results, suggesting routine culture at the initial point of contact with the health care system may play a pivotal role in addressing this widely prevalent and devastating disease.
Overview of HCV Life Cycle with a Special Focus on Current and Possible Future Antiviral Targets
Authors: Alazard-Dany Nathalie , Denolly Solène , Boson Bertrand , Cosset François-Loïc
Published: January 2019

Hepatitis C infection is the leading cause of liver diseases worldwide and a major health concern that affects an estimated 3% of the global population. Novel therapies available since 2014 and 2017 are very efficient and the WHO considers HCV eradication possible by the year 2030. These treatments are based on the so-called direct acting antivirals (DAAs) that have been developed through research efforts by academia and industry since the 1990s. After a brief overview of the HCV life cycle, we describe here the functions of the different targets of current DAAs, the mode of action of these DAAs and potential future inhibitors.
Experimental Evaluation of the Role of Ecologically-Relevant Hosts and Vectors in Japanese Encephalitis Virus Genotype Displacement
Authors: Karna Ajit K. , Bowen Richard A.
Published: January 2019

Japanese encephalitis virus (JEV) is a flavivirus that is maintained via transmission between Culex spp. mosquitoes and water birds across a large swath of southern Asia and northern Australia. Currently JEV is the leading cause of vaccine-preventable encephalitis in humans in Asia. Five genotypes of JEV (G-I–G-V) have been responsible for historical and current outbreaks in endemic regions, and G-I and G-III co-circulate throughout Southern Asia. While G-III has historically been the dominant genotype worldwide, G-I has gradually but steadily displaced G-III. The objective of this study was to better understand the phenomenon of genotype displacement for JEV by evaluating both avian host and mosquito vector susceptibilities to infection with representatives from both G-I and G-III. Since ducks and Culex quinquefasciatus mosquitoes are prevalent avian hosts and vectors perpetuating JEV transmission in JE endemic areas, experimental evaluation of virus replication in these species was considered to approximate the natural conditions necessary for studying the role of host, vectors and viral fitness in the JEV genotype displacement context. We evaluated viremia in ducklings infected with G-I and G-III, and did not detect differences in magnitude or duration of viremia. Testing the same viruses in mosquitoes revealed that the rates of infection, dissemination and transmission were higher in virus strains belonging to G-I than G-III, and that the extrinsic incubation period was shorter for the G-I strains. These data suggest that the characteristics of JEV infection of mosquitoes but not of ducklings, may have play a role in genotype displacement.
A Comprehensive RNA-seq Analysis of Human Bocavirus 1 Transcripts in Infected Human Airway Epithelium
Authors: Zou Wei , Xiong Min , Deng Xuefeng , Engelhardt John , Yan Ziying , Qiu Jianming
Published: January 2019

Human bocavirus 1 (HBoV1) infects well-differentiated (polarized) human airway epithelium (HAE) cultured at an air-liquid interface (ALI). In the present study, we applied next-generation RNA sequencing to investigate the genome-wide transcription profile of HBoV1, including viral mRNA and small RNA transcripts, in HBoV1-infected HAE cells. We identified novel transcription start and termination sites and confirmed the previously identified splicing events. Importantly, an additional proximal polyadenylation site (pA)p2 and a new distal polyadenylation site (pA)dREH lying on the right-hand hairpin (REH) of the HBoV1 genome were identified in processing viral pre-mRNA. Of note, all viral nonstructural proteins-encoding mRNA transcripts use both the proximal polyadenylation sites [(pA)p1 and (pA)p2] and distal polyadenylation sites [(pA)d1 and (pA)dREH] for termination. However, capsid proteins-encoding transcripts only use the distal polyadenylation sites. While the (pA)p1 and (pA)p2 sites were utilized at roughly equal efficiency for proximal polyadenylation of HBoV1 mRNA transcripts, the (pA)d1 site was more preferred for distal polyadenylation. Additionally, small RNA-seq analysis confirmed there is only one viral noncoding RNA (BocaSR) transcribed from nt 5199–5340 of the HBoV1 genome. Thus, our study provides a systematic and unbiased transcription profile, including both mRNA and small RNA transcripts, of HBoV1 in HBoV1-infected HAE-ALI cultures.
A Spatial and Temporal Study of the Green and Blue Water Flow Distribution in Typical Ecosystems and its Ecosystem Services Function in an Arid Basin
Authors: Zang Chuanfu , Mao Ganquan
Published: January 2019

Research on relationship between green and blue water flow and ecosystem service functions has great significance for improving water resources management and for ecological protection. In this study, the distribution patterns and service functions of green and blue water flow in different ecosystems were analysed by Soil and Water Assessment Tool (SWAT) model simulation and Correlational Analysis. In the entire basin, the amount of green and blue water flow in the grassland was greater than that in the cropland, and that in the cropland was larger than that in the forest. The corn yield per hectare of cropland was highest in the Heihe River Basin, followed by wheat, and the lowest yield was the oil yield from 2000 to 2010. The mutton yield in the grassland ecosystem was greater than the beef yield from 2000 to 2010, which shows that the beef production would consume more water flow. Results show an obvious positive correlation between green or blue water flow and wheat and corn yields. Beef and mutton had a significant correlation with blue water flow, whereas mutton had a stronger correlation with green water flow.
A consultation-level intervention to improve care of frequently attending patients: a cluster randomised controlled feasibility trial
Authors: Barnes Rebecca K , Cramer Helen , Thomas Clare , Sanderson Emily , Hollinghurst Sandra , Metcalfe Chris , Jackson Sue , Record Charlie , Thorley Helen , Kessler David
Published: January 2019

Background

Frequent attenders (FAs) to primary care receive considerable NHS resources without necessarily gaining benefit, and may even be harmed.

Aim

To assess the feasibility of a consultation-level intervention to improve care and address service use of FAs.

Design & setting

A cluster randomised controlled feasibility trial was undertaken. The study used a mixed-methods process evaluation and took place in six practices in England.

Method

All practices screened the top 3% of all attending patients over the previous 12 months for eligibility. Following randomisation, intervention patients were matched with named GPs, trained to use the Background, Affect, Trouble, Handling, Empathy (BATHE) technique during consultations. Telephone consultations were encouraged. Feasibility outcomes assessed were recruitment, retention, data collection and completeness, implementation fidelity, and acceptability

Results

A total of 599/1328 (45.1%) FAs were eligible. Four practices were randomised to the intervention (n = 451) and two to usual care (n = 148). A total of 96 (23.7%) patients were recruited to complete questionnaires. Retention and completeness of data were good; for example, 76% of those agreeing to complete questionnaires did so at the 12-month assessment point. Thirty-four GPs were trained and delivered BATHE ≥1 times to 50.1% of patients (n = 577 consultations). There were minimal increases in continuity and telephone consultations. Patients were positive about the intervention, but noticed little change in their care. Despite valuing BATHE, low adherence to training was indicated and GPs used it less than anticipated.

Conclusion

It was feasible to identify FAs and collect trial data. GPs were keen to engage and there was evidence that the BATHE technique was taken into practice. Optimising training is likely to improve fidelity. The intervention was low cost and low risk.
Most Lensed Quasars at z > 6 are Missed by Current Surveys
Authors: Pacucci Fabio , Loeb Abraham
Published: January 2019

The discovery of the first strongly lensed (μ ≈ 50) quasar at z > 6 (J0439+1634) represents a breakthrough in our understanding of the early universe. We derive the theoretical consequences of the new discovery. We predict that the observed population of z > 6 quasars should contain many sources with magnifications μ ≲ 10 and with image separations below the resolution threshold. Additionally, current selection criteria could have missed a substantial population of lensed z > 6 quasars, due to the contamination of the drop-out photometric bands by lens galaxies. We argue that this predicted population of lensed z > 6 quasars would be misclassified and mixed up with low-z galaxies. We quantify the fraction of undetected quasars as a function of the slope of the bright end of the quasar luminosity function, β. For β ≲ 3.6, we predict that the undetected lensed quasars could reach half of the population, whereas for β ≳ 4.5 the vast majority of the z > 6 quasar population is lensed and still undetected. This would significantly affect the z > 6 quasar luminosity function and inferred black hole mass distributions, with profound implications for the ultraviolet, X-ray, and infrared cosmic backgrounds and the growth of early quasars.
Un monde habitable par tous
Authors: Pranchère Jean-Yves
Published: January 2019

Les droits de l’homme sont essentiellement solidaires de la révolution démocratique. Et cette dernière est d’abord un mouvement social, qui ouvre un espace dans lequel la société peut se rapporter à ses conditions matérielles, ses projections imaginaires et son ordre symbolique. La vague néolibérale, qui accroît les inégalités et induit la perte du symbolique, requiert donc une reprise de la question sociale au nom de la démocratie.
L’énigme de la démocratie sauvage
Authors: Chollet Antoine
Published: January 2019

La démocratie sauvage dessine une troisième voie entre totalitarisme et conservatisme : celle de la revendication de droits nouveaux. Sans cette fragile puissance de désordre, la démocratie institutionnelle peut dériver vers le totalitarisme.
Sorties de conflit : toutes les vérités sont-elles bonnes à dire ?
Authors: Hubrecht Joël
Published: January 2019

A partir des années 1970, notamment dans les pays d’Amérique latine qui ont connu la dictature militaire, puis en Afrique du Sud après l’apartheid, émerge un droit à la vérité. Ce droit est fragile tant la notion de vérité est équivoque et tant les obstacles politiques sont nombreux, mais il est fondateur pour les pratiques de justice transitionnelle.
Le rêve chinois de religion civile
Authors: Vermander Benoît
Published: January 2019

Depuis 2012, l’équipe dirigeante de la Chine construit une nouvelle religion civile, par laquelle l’Etat reprend sa fonction de pourvoyeur de sacralité, contrôle strictement les cultes locaux et organise la vénération de la terre chinoise éternelle. On peut se demander si un tel rêve chinois peut accrocher sur les nouvelles réalités urbaines du pays.
Enjeux migratoires et nouvelle géopolitique à l’interface Amérique latine-États-Unis
Authors: Faret Laurent
Published: January 2019

À partir d’une mise en perspective des dynamiques de migration internationale dans l’espace nord- et centraméricain, l’article vise à éclairer les enjeux géopolitiques actuels des questions de mobilité humaine dans la région. Dans un contexte où l’externalisation des frontières et les positionnements sécuritaires sont de plus en plus prégnants, la persistance des mobilités et leur imbrication avec d’autres enjeux contemporains ont placé comme rarement auparavant les questions migratoires au centre des relations internationales. Au-delà de la rhétorique de l’hypothétique mur à la frontière États-Unis-Mexique, l’article s’intéresse aux recompositions récentes des logiques migratoires et des politiques de contention tout au long du couloir migratoire centraméricain. La frontière sud du Mexique est aujourd’hui au cœur des enjeux migratoires, dans un jeu de miroirs inédit avec la frontière nord. Les vulnérabilités des populations en mouvement dans des environnements de plus en plus violents apparaissent comme l’enjeu principal du traitement politique des migrations.
Le basculement religieux latino-américain
Authors: Rodríguez Cuadros José Darío
Published: January 2019

Cet article analyse le récent basculement religieux latino-américain marqué par une baisse de la pratique catholique, une montée en force des Églises évangéliques et une sécularisation croissante au cours des trente dernières années. Trois approches sont proposées pour examiner le phénomène : la prise de distance de l’ensemble du continent vis-à-vis du religieux, les crises internes à l’Église catholique du fait des débats autour du concile Vatican II et de la théologie de la libération, et le monde des Églises évangéliques. Selon l’analyse proposée, cet article montre la complexité du monde religieux latino-américain d’aujourd’hui. Un continent où la religion est toujours un élément clé pour mieux comprendre ses dynamiques et évolutions.
Civilisation écologique chinoise et croyances développementalistes : une analyse critique et comparée des projections idéologiques sur les liens entre environnement, économie et culture
Authors: Heurtebise Jean-Yves
Published: January 2019

La Chine, ce n’est pas seulement un territoire, un pays, un empire, une langue, une culture, un parti mais aussi et d’abord une image. Une image de « l’Autre », source de rêveries, fantasmes et des nombreuses projections d’un Occident qui peut s’estimer ainsi lui-même à la fois unique, spécifique et à part. Récemment, la Chine a été à la fois émettrice et réceptacle d’une quadruple projection idéologique : développementaliste (miracle chinois), libérale (théorie de la modernisation), pacifiste (« émergence pacifique ») et écologiste (« civilisation écologique »). Ce que nous voudrions étudier dans cet article, ce sont les rapports existants entre « l’illusion libérale » émise par les « Occidentaux » concernant la Chine et « l’illusion écologiste » produite par la Chine à travers la notion de « civilisation écologique chinoise ». Nous commencerons par présenter les quatre « illusions » (développementaliste, libérale, pacifiste et écologiste) pour analyser ensuite les relations entre la seconde et la quatrième de celles-ci en évoquant leur intrication avec la notion de « courbe de Kuznets environnementale ».
Gloires et déboires de l’économie nord-coréenne
Authors: Lévi Nicolas
Published: January 2019

L’économie nord-coréenne a connu de nombreuses difficultés dans les années 1980 et 1990. Malgré son modèle idéologique, qui prône l’autosuffisance, elle est basée sur la coopération économique avec les pays voisins tels que la Chine et la Corée du Sud. Pour le moment, le modèle de développement économique de la Corée du Nord appliqué depuis une vingtaine d’années rappelle singulièrement les stratégies économiques des pays voisins. Kim Jong-un fait face à un défi inédit : tourner définitivement la page et renier le modèle économique en vigueur, ou continuer d’enfoncer le pays dans la crise.
La péninsule coréenne, entre autonomie et dépendance
Authors: Bondaz Antoine
Published: January 2019

Cet article, après avoir procédé à de brefs rappels historiques indispensables pour comprendre l’influence des puissances étrangères dans la péninsule, vise à dresser un panorama non exhaustif des grands enjeux liés à la recherche d’une autonomie par les deux Corées, quand bien même ceux-ci demeurent profondément dépendants de leurs soutiens respectifs. Nous verrons que l’appel à une autonomisation des relations intercoréennes n’est pas nouveau, tant à Séoul qu’à Pyongyang, puis reviendrons sur le rôle joué par la Chine et les États-Unis, les alliés indispensables, mais aussi par le Japon et la Russie, les voisins utiles.
Incidence des événements indésirables associés au cathéter veineux périphérique dans un service de cardiologie, Tunisie
Authors: Ghali Héla , Rejeb Oussama Ben , Bouafia Nabiha , Ernez Samia , Mahjoub Mohamed , Njah Mansour , Mahdhaoui Abdallah , Gouider Jridi
Published: January 2019

Objectif : Déterminer l’incidence des événements indésirables (EI) associés aux cathéters veineux périphériques (CVP). Méthodes : Une étude prospective d’incidence a été menée dans un service de cardiologie sur une période de trois mois. Tous les patients hospitalisés et ayant bénéficié de la pose d’un CVP durant la période de l’étude ont été inclus. La détection des EI associés au CVP a été assurée grâce à un suivi régulier (toutes les 12 heures) durant toute la période de maintien du CVP et poursuivie jusqu’à 48 heures après son ablation. Résultats : Ont été colligés 148 patients d’âge moyen 63,37 ± 12,26 ans, avec une légère prédominance masculine ( n  = 76 ; 51,4 %). Les antécédents médicaux les plus fréquents étaient l’hypertension artérielle (56,1 %) et l’obésité (39,2 %). Une prise d’antibiothérapie à l’admission a été notée dans 16,2 % des cas, pour lesquels l’amoxicilline/acide clavulanique était la molécule la plus prescrite (4,1 %). Au total, 210 CVP (soit 794 jours de cathétérisme) ont été étudiés. La durée moyenne de maintien était de 5,36 ± 3,95 jours. Il en est ressorti que 38 CVP étaient à l’origine de 70 EI. L’incidence était de 33,33 % et sa densité s’élevait à 8,81 EI pour 1 000 journées de CVP. La complication la plus fréquente était la douleur ( n  = 35 ; 50 %), suivie par les complications mécaniques ( n  = 22 ; 31,42 %). Conclusion : Ces résultats montrent que l’incidence des EI associés au CVP est élevée. L’analyse des principaux facteurs de risque de survenue de ces EI permettrait de mieux identifier les actions de prévention à entreprendre.
Population et pathologies dépistées au Centre de dépistage départemental de la Seine-Saint-Denis
Authors: Sulli Laura , Mangin Floréale , Lassau François , Nicoulet Isabelle , Marmier Mathilde
Published: January 2019

Contexte : Depuis 2016, le département de la Seine-Saint-Denis est habilité « Centre gratuit d’information, de dépistage et diagnostic » (CeGIDD), avec un nouveau site principal à Bobigny et quatre antennes. Méthodes : Un recueil de données anonyme à visée « santé publique et activité » a été mis en place sur le site principal dès 2016, pour tous les usagers. L’étude présente une description des patients et des pathologies dépistées lors de la première année d’activité. Résultats : Le public était pour 59,6 % de sexe masculin, l’âge médian s’élevait à 26 ans et près de 30 % étaient nés à l’étranger. La part de public prioritaire consultant au CeGIDD a pu être comptabilisée ; elle atteint 70,6 %. Ainsi, 8,3 % étaient un public de type LGBT (lesbiennes, gays, bisexuels et transgenres), 6,3 % des patients étaient des usagers de drogues, 2,4 % se prostituaient et 2,3 % avaient été incarcérés. Conclusion : Le CeGIDD départemental est une structure à fort potentiel. Les taux de positivité (virus de l’immunodéficience humaine [VIH], chlamydiae) sont supérieurs aux taux retrouvés dans les références nationales et départementales. Après une première année, l’activité devrait encore se développer et toucher davantage les populations les plus éloignées des dispositifs. Le recueil de données généralisé depuis 2017 aux antennes et aux actions hors les murs enrichira la connaissance des usagers.
Représentations sociales de l’épilepsie et itinéraires thérapeutiques des parents d’enfants à Abidjan
Authors: Kouassi Ettié Silvie , Bissouma Anna-Corinne , Adon Kouadio Patrick , Moke Botthy Lambert
Published: January 2019

Objectif : La présente étude examine l’influence des représentations des épilepsies infantiles dans leur forme généralisée sur les itinéraires thérapeutiques des parents en quête de soins pour leurs enfants épileptiques. Méthodes : L’approche utilisée est rétrospective, quantitative et qualitative. Le recueil des données a été fait au moyen de l’analyse des dossiers médicaux de 81 enfants diagnostiqués épileptiques et pris en charge au CGI d’Abidjan (Côte d’Ivoire) sur une période de 18 mois (de janvier 2015 à juin 2016), et d’un entretien semi-directif adressé à leurs parents venus les ­accompagner pour leur suivi médical. Résultats : Les données recueillies ont été traitées par le Khi 2 de Pearson. Les résultats obtenus, interprétés à la lumière de la théorie des représentations sociales, confirment que les représentations des épilepsies infantiles influencent le recours aux soins des parents d’enfants épileptiques. Conclusion : La prise en charge des enfants épileptiques exige : l’adhésion de leurs parents au projet de soins en tenant compte de leur parcours de soins, la formation des agents de santé communautaire ainsi que des études de recherches pluridisciplinaires sur les épilepsies infantiles.
Prévalence et déterminants sociaux de l’anémie chez les femmes enceintes dans la Province d’Essaouira, Maroc
Authors: Ouzennou Nadia , Tikert Kabira , Belkedim Ghizlane , Jarhmouti Fatim Ezzahra
Published: January 2019

Objectifs : Cette étude a pour objectif de déterminer la prévalence de l’anémie chez les femmes enceintes et les facteurs qui lui sont associés au Maroc, plus particulièrement dans la province d’Essaouira. Méthode : Afin de déterminer la prévalence de l’anémie, ont été analysés, entre février 2015 et janvier 2016, 3 806 dossiers obstétricaux des femmes enceintes, parmi lesquelles 1 558 étaient anémiques. Le taux d’hémoglobine a permis de définir, classer et calculer la sévérité de l’anémie. Afin d’étudier les facteurs associés à l’anémie, une enquête transversale a été réalisée par questionnaire auprès de 725 femmes enceintes choisies selon un échantillonnage simple aléatoire. Ont été récoltées des informations relatives aux caractéristiques biodémographiques, socio-économiques et socioculturelles, puis une régression logistique binaire a été réalisée afin d’apprécier l’association entre ces facteurs et l’anémie. Des données sur le régime alimentaire des femmes anémiques ont été également recueillies. Résultats : La prévalence de l’anémie chez les femmes enceintes de la province d’Essaouira s’élevait à 41 %. Les résultats de la régression logistique binaire ont montré que l’anémie était associée statistiquement à la gestité, la provenance et l’instruction de la femme. Le régime alimentaire des femmes anémiques pauvres en fer serait également un facteur qui favoriserait le développement de l’anémie dans cette province. Conclusion : Au Maroc, l’ampleur des problèmes nutritionnels entraverait le développement humain et l’amélioration de l’état de santé. La connaissance de la sévérité des carences est nécessaire pour développer des interventions adaptées au contexte national.
Les réseaux sociaux numériques et le développement controversé de savoirs d’expérience sur les transidentités
Authors: Lallet Mélanie , Delias Lucie
Published: January 2019

Cet article étudie la façon dont les outils mis à disposition sur l’internet, et en particulier les réseaux sociaux numériques, ont permis aux personnes trans de créer des communautés virtuelles d’apprentissage ayant pour but d’opérer une remédiation des savoirs d’expériences concernant aussi bien les aspects techniques de la transition que les définitions des identités de genre. Ce processus est abordé d’un point de vue historique, en montrant une évolution concomitante des plateformes d’échanges en ligne et des revendications des mouvements militants trans qui deviennent de plus en plus hybrides et inclusives.
Evaluating a Web-based Graduate Level Nursing Ethics Course: Thumbs Up or Thumbs Down?
Authors: McAlpine Heather , Lockerbie Linda , Ramsay Deyanne , Beaman Sue
Published: January 2019

ABSTRACT

Background: This article discusses the course design, experiential findings, and evaluation of a Web-based course for graduate nurses examining professional health care practice and ethical issues.

Method: Using course input and evaluative data, the article addresses student and teacher perceptions of use of a Web-based delivery mode for graduate level courses and the appropriateness of this ethics course for graduate level students.

Results: Evaluative data supported existing knowledge concerning pros and cons of Webbased education. New insights concerning the Web's ability to foster critical thinking skills and supports for continuing ethics education for nurses are reported. All students assessed this ethics course as being of considerable value to their professional practice.

Conclusion: Students evaluated the pros of Web use for the course as far outweighing the cons. The students' substantial interest in and critical thinking about appropriate knowledge bases to underpin effective ethical decision-making strongly supports the need for continuing ethics education for practicing nurses.
Affective Experience of Music: Emotional and Color Perception of Folk and Other Musical Genres
Authors: Strle Gregor , Pesek Matevž , Marolt Matija
Published: January 2019

The article presents an experimental study of the emotional and color perception of music, focusing on folk music in comparison with other musical genres. The analysis showed that some musical emotions are conveyed differently between different genres. Overall, Folk genre had the most balanced distribution of the emotions used in the ratings, along with Pop and Rock. On the other hand, Punk and Metal had over 40% of their ratings represented by only two emotions, liveliness and anger. This is further reflected in the emotioncolor associations. The presented findings point to the genre specificity of musical emotions.
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Prispevek predstavlja eksperimentalno raziskavo čustvenega in barvnega zaznavanja glasbe, s poudarkom na primerjavi med ljudsko glasbo in drugimi glasbenimi zvrstmi (žanri). Analiza rezultatov je pokazala, da so ob poslušanju glasbe različnih glasbenih zvrsti čustvene zaznave pogosto različne. Najbolj uravnotežena in raznovrstna je porazdelitev čustev pri popu, rocku in ljudski glasbi, najmanj pa pri panku in metalu, pri katerih več kakor 40 % glasbenih primerov prevzemata le dve čustvi, to sta živahnost in jeza. Ugotovitve se izražajo tudi v čustveno-barvnih asociacijah. Rezultati kažejo na žanrsko specifičnost »glasbenih« čustev.
Impact of sound stimulation during different sleep stages in patients with tinnitus
Authors: Pedemonte Marisa , Díaz Marcela , Medina-Ferret Eduardo , Testa Martín
Published: January 2019

It is known that auditory information is continuously processed both during wakefulness and sleep. Consistently, it has been shown that sound stimulation mimicking tinnitus during sleep decreases the intensity of tinnitus and improves the patients’ quality of life. The mechanisms underlying this effect are not known. To begin to address this question, eleven patients suffering from tinnitus were stimulated with sound mimicking tinnitus at different sleep stages; 4 were stimulated in N2, 4 in stage N3 (slow waves sleep) and 3 in REM sleep (stage with Rapid Eyes Movements). Patients’ sleep stage was monitored through polysomnography, for sound stimulation application. Tinnitus level reported by subjects were compared the days before and after stimulation and statistically analyzed (paired Student t test). All patients stimulated at stage N2 reported significantly lower tinnitus intensity the day after stimulation, while none stimulated during stage N3 and only one out of three stimulated during REM sleep showed changes. These results are consistent with studies showing that sound stimulation during N2 (sleep stage with spindles) changes power spectrum and coherence of electroencephalographic signals, and suggest that the N2 sleep stage is a critical period for reducing tinnitus intensity using this therapeutic strategy, during which auditory processing networks are more malleable by sound stimulation.
Adsorption of H2S Gas by Modified Diatomite and Leonardite
Authors: Chomkitichai Weerasak , Sujit Panjaporn , Ketwaraporn Jiraporn , Pookmanee Pusit , Phanichphant Sukon , Jansanthea Pongthep
Published: January 2019

This research aimed to modify of diatomite and leonardite for adsorption of hydrogen sulfide (H2S) gas. The effect of chemical loading on surface modification was studied. Natural diatomite and leonardite were obtained through the natural deposits in Lampang Province, Thailand. Diatomite and leonardite were modified using chemical methods with calcination at 450 °C. The chemical composition and phase structure of adsorbents were characterized by X–Ray fluorescence spectroscopy (XRF) and X–ray diffraction (XRD), respectively. The morphology and disperse energy of the elements were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional group was identified by Fourier transform infrared spectroscopy (FT–IR). The efficiency of adsorption of H2S gas was studied. H2S gas in this study was synthesized by the chemical reaction between sodium sulfide (Na2S) and sulfuric acid (H2SO4). The concentration of hydrogen sulfide was measured by an H2S gas detector. The performance of the modified diatomite and leonardite for adsorption of H2S was compared. It was found that modified diatomite has better efficiency than modified leonardite for the adsorption of H2S gas. After modification process, the adsorption efficiency increased while the adsorption time decreased.
Effect of Filler Types on Properties of the Natural Rubber Closed Cell Foam
Authors: Phumnok Ekaroek , Boonphang Jakkrit , Bourkaew Orrachorn
Published: January 2019

In this research, effects of filler types and their loading on properties of the natural rubber closed cell foam were investigated. The azodicarbonamide was used as a blowing agent in 4 phr loading. The filler types that are the N-330 grade of carbon black, precipitated calcium carbonate and rubber grade china clay, their loading was varied from 0 to 50 phr (part per hundred dried rubber). The physical properties of the rubber foam that are the difference torque from the oscillating disk rheometer, hardness, tear strength, 300% modulus, tensile strength, elongation at break and compression set were analyzed. The results were found that the carbon black was yielded the highest of all properties in every loading. In conclusion, the suitable filler for closed cell rubber foam is the carbon black.
Preparation of Semi-Solid A390 Aluminum Alloy Slurry through a Serpentine Pouring Channel
Authors: Mao Wei Min , Yan Peng Yu , Zheng Z.K.
Published: January 2019

In order to study the possibility of refining the primary silicon grains in the microstructure of hypereutectic Al-Si alloy through a serpentine pouring channel, the semi-solid slurry of A390 aluminum alloy was prepared through a water-cooled copper serpentine pouring channel, which is a new method proposed recently for semi-solid forming process, and the effect of pouring temperature on the slurry microstructure was investigated. The results show that the slurry of A390 aluminum alloy with refined primary silicon grains can be prepared under given conditions and especially when the pouring temperatures is 690°C, the primary silicon grains can be refined obviously, the equivalent silicon grain size is 19.7mm and the average shape factor is about 0.7. The analysis shows that the chilling effect of the inner channel wall precipitates a large number of primary silicon nuclei, and so the primary silicon grains are refined greatly. Meanwhile, the subsequent alloy melt washing also promotes the separation of primary silicon grains from the inner wall and the primary silicon grains are further refined. The work undertaken demonstrates eventually that the serpentine pouring channel process is a good method for refining the primary silicon grains in hypereutectic A390 alloy rather than using chemical fining agent phosphorus as in traditional process, and provides an alternative process choice.
Experimental Study on CF/Al Composite Plate with Complex Curved Surface Fabricated by Liquid-Solid Infiltration Extrusion
Authors: Qi Le Hua , Han Li Jun , Zhou Ji Ming , Meng Hai Ming , Yu Xin , Ma Wen Jing
Published: January 2019

In this paper, continuous carbon fiber reinforced aluminum matrix (Cf/Al) composite plate with complex curved surface is fabricated by liquid-solid infiltration extrusion. The influence of fabrication parameters, such as the melting temperature, extrusion temperature and extrusion pressure on the Cf/Al composite plate is studied. The experimental results show that the liquid-solid infiltration extrusion process can be used to fabricate the Cf/Al composite with curved surface. The Cf/Al composite exhibits good infiltration and well-formed quality when the extrusion pressure is 50MPa, the extrusion temperature is 670°C and the melting temperature is 690°C. According to the microstructure observation, the carbon fiber uniformly distributes in the aluminum alloy matrix without damage and obvious defects. The density of the composite is decreased by 17.9%, from 2.71g/cm3 to 2.29g/cm3, which is lower than that of the matrix alloy, and the ultimate tensile strength is increased by 120% compared with the matrix alloy, from 127MPa to 279MPa.
Thixoforming of Wrought Aluminum Alloy 1973
Authors: Ngo Thanh Binh , Semenov A.B. , Semenov B.I.
Published: January 2019

In this paper, the microstructure and mechanical properties of thixoformed 1973 (AlZn5.5Mg2.4Cu1.7Zr) wrought aluminium alloy were investigated. A cooling slope was used to produce non-dendritic billets. Thixoforming process parameters were determined as follows: die temperature of 250 °C, feedstock temperature of 600 - 605 °C, punch velocity of 7 mm/s. Mechanical properties of thixoformed with ultimate strength of 461 MPa and elongation of 3,1 % in the T2 condition. The lower properties of the thixoformed material are mainly associated with porosity.
Thixoforming of Semisolid Slurry with High Fraction Solid Fabricated by Partial Melting of Commerical Wrought Aluminum Alloys
Authors: Jiang Ju Fu , Liu Ying Zhe , Xiao Guan Fei , Wang Ying
Published: January 2019

Semisolid slurries of four wrought alloys were fabricated via partial melting of commerical wrought aluminum alloy. Thixoforming experiments of four typical parts were performed. The results showed that a large amount of equiaxed grains before soaking in semisolid state were created due to recrystallization occurred in the continuous heating from room temperature to a given temperature above recrystallization temperature. It provides a desirable microstructure to form spheroidal grains during the next soaking process in semisolid state. The microstructure of the 2A12,7A04 and 7075 semisolid slurry consisted of fine and spheroidal grains. The elongation of the thixoformed parts were higher those of the hot-rolled plate. The UTS of the thixoformed parts were close or ever higher than those of the hot-rolled plate. Although the grain size and roundness of the 5A06 semisolid slurry are not very desirable, the mechanical properties of the thixoformed part are close or ever than those of the hot-rolled plate. The high mechanical properties of the thixoformed parts further confirmed the feasibility of short-process thixoforming route
Effects of Annular Electromagnetic Stirring Melt Treatment on Microstructure and Mechanical Properties of 7050 Rheo-Casting
Authors: Guan Tian Yang , Zhang Zhi Feng , He Min , Bai Yue Long , Wang Ping
Published: January 2019

The microstructure and mechanical properties of 7050 alloy rheo-castings after treated by Annular Electromagnetic Stirring (A-EMS) melt treatment were investigated. The results revealed that, under A-EMS, the refinement and homogeneity of the solidification structure could be improved greatly and the slurry was suitable for the following rheo-casting; and also the hot-cracking defects in the casting process were significantly alleviated, meanwhile, the strength and ductility of the alloy casting were found to be comparable to those of conventionally forged 7000 series alloys.
Microstructure and Properties of Semi-Solid CuSn10P1 Alloy under Different Filling Velocity by Squeeze Casting
Authors: Li Yong Kun , Zhou Rong Feng , Li Lu , Xiao Han , Jiang Ye Hua
Published: January 2019

Semi-solid CuSn10P1 alloy slurry was fabricated by a novel enclosed cooling slope channel (for short ECSC). The effect of filling velocity on microstructure and properties by squeeze casting was studied. The results showed that primary α-Cu phase gradually formed from dendrites evolved into worm-like or equiaxed crystals by ECSC. As the filling velocity increases, the ultimate tensile strengths and elongations of the shaft sleeve increase first and then decrease. The ultimate tensile strength and elongation of semi-solid squeeze casting CuSn10P1 alloy reached a maximum of 417.6MPa and 12.6% when the forming pressure is 100MPa and filling velocity is 21mm/s, which were improved by 22% and 93%, respectively, as compared to that of liquid squeeze casting.
Numerical Simulation of Slurry Making Process of 7075 Aluminum Alloy under Electromagnetic Field in Rheocasting Process
Authors: Li Gan , Lu Hong Xing , Hu Xiao Gang , Zhu Qiang
Published: January 2019

Rheocasting processes have several technological advantages, such as shorter processing and lower cost than thixocasting processed, while better product quality than conventional die casting. At present, the common alloys used in rheocasting processes are mainly Al-Si alloys which have limited strength. There is a strong demand for higher strength aluminum alloys in industries, for instance the 7075 aluminum alloy. However, the solid fraction of the 7075 aluminum alloy varies significantly with the temperature change in the medium solid fraction range from 0.4 to 0.6, which poses a great challenge to the slurry preparation. The enthalpy compensation process, in which the core was electromagnetic heating in the outside of the metallic crucible containing aluminum alloy melt, has been proposed to reduce the temperature difference within semi-solid slurry in this work. This study used simulation method to analyze the effects of key process parameters on the temperature difference within the 7075 aluminum alloy slurry. The simulation results indicated that semi-solid slurry with medium solid fraction may be obtained and temperature difference may be reduced to less than 4°C.
Viscoelastic Properties of Thixotropic Semisolid Alloy Relating the Microstructure
Authors: Sanjuan-Sanjuan Gerardo , Chavez-Castellanos Ángel Enrique
Published: January 2019

The subject of this work is to investigate viscoelastic properties such as loss modulus (G ́ ́), storage modulus (G ́), complex shear modulus (G*), complex viscosity (η*) and loss angle () at different temperatures by means of a small-amplitude oscillatory test. These properties allow to provide information about materials structure. For this purpose, we employed a tin-lead alloy (Sn-15%Pb) which exhibits a similar microstructure to aluminum alloys and is the classic alloy for semisolid thixotropic studies. It is interesting to note that the Sn-15%Pb alloy exhibits a slightly decrease in storage modulus (G ́) over the entire frequency (0.01-10Hz) at high temperatures, showing its viscoelastic behavior. In addition, a detailed analysis of master curves (oscillatory tests) was made to relate the semisolid microstructure (solid fraction) with the plateau modulus (GN0) which is directly related with both molecular weight or percolation threshold in polymer and gels science respectively.
Semisolid Forging of 250 Automotive Spindles of S48C Steel
Authors: Lozares Jokin , Plata Gorka , Hurtado Iñaki , Azpilgain Zigor , Loizaga Iñigo
Published: January 2019

Nowadays, globalisation enables a rapid uptake of the classical manufacturing technologies. In order to remain competitive and fulfil the global trend of reduction of emissions, innovative production processes that reduce the energy and raw material consumption should arise. Semisolid forging (SSF) is one of those techniques with great potential to fulfil those requirements maintaining the high quality of the components. Thus, the objective of this work is twofold: to produce a complex geometry part saving material and energy using the off-the-shelf S48C steel grade, and to demonstrate the capability of the process to produce a pre-series of 250 components without excessive tooling damage.
Thixoforming of Hypereutectic AlSi12Cu2NiMg Automotive Pistons
Authors: Semenov A.B. , Ngo Thanh Binh , Semenov B.I.
Published: January 2019

The microstructure and mechanical properties of thixoformed AlSi12Cu2NiMg (AЛ25) aluminium alloy were investigated. Cooling slope method was employed in order to produce non-dendritic billets. Thixoforming process parameters were determined as follows: die temperature of 250 °C, billet temperature of 555 - 560 °C, punch velocity of 7 mm/s. Mechanical properties of automotive piston with ultimate strength of 309 MPa, yield strength of 274 MPa and elongation of 6.8 % in the T6 condition were obtained successfully, implying success of advantages of cooling slope method.
GISS Technology: Principle and Applications in Die Casting
Authors: Wannasin Jessada , Fuchs Marc , Lee Ji Yong , Lee CU , Narasimha Rao T.V.L. , Flemings Merton C.
Published: January 2019

In the past, there have been a lot of effort to solve gas and shrinkage porosity defects in die casting. The common solutions are vacuum technology, jet cooling technology, and application of squeeze pins. However, these solutions often increase the die casting production costs. A new solution that has recently been introduced worldwide is GISS Technology. This technology applies the superheated slurry casting process. Gas and shrinkage porosity defects can be reduced. Furthermore, the production costs are lowered due to die life extension, cycle time reduction, melting energy reduction, and lubrication usage reduction. This paper describes the principle of GISS Technology, and selected applications and case studies are also be presented.
Structural Characteristics of Metal-Ceramic Interpenetrating Phase Composites Manufactured by Using Semi-Solid Forming Technology
Authors: Schomer Laura , Liewald Mathias
Published: January 2019

Interpenetrating Phase Composites (IPC) belong to a special subcategory of composite materials and reveal enhanced properties compared to the more common particle or fibre reinforced composite materials. However, as the use of conventional manufacturing processes creates structural deficits, these IPC are not able to exploit their complete potential. In this respect, infiltration of open-pore bodies from alumina with an aluminium alloy in the semi-solid state offers great perspectives for manufacturing of IPC. In this context, this paper is focusing on significant structural characteristics of metal-ceramic IPC produced in this way by using a tool with an open die cavity. Thereby, the macroscopic mould filling, possible damage of the ceramic body, the residual porosity, the filling of microporosity of the cell walls and possible interface reactions depending on the thermal parameters of the manufacturing process were investigated in this paper.
Effects of High Pressure on Fe-Rich Phases and Mechanical Properties of Al-14Si Alloys with Rheo-Squeeze Casting
Authors: Lin Chong , Wu Shu Sen , Lü Shu Lin
Published: January 2019

The influence of high pressure and manganese on Fe-rich phases (FRPs) and mechanical properties of Al-14Si-2Fe alloy with rheo-squeeze casting (RSC) were investigated. The semi-solid alloy melt was prepared using ultrasonic vibration (UV), then formed by squeeze casting (SC). Results shows that the FRPs in as-cast Al-14Si-2Fe-(0.4,0.8)Mn alloys with SC are composed of coarse plate-shaped δ-Al4(Fe,Mn)Si2, long needle-shaped β-Al5(Fe,Mn)Si and bone-shaped α-Al15(Fe,Mn)3Si2 phases when the pressure is 0 MPa. During the solidification of the alloys with RSC, the FRPs are first refined by UV, then furtherly refined as the pressure increases. With RSC, the FRPs in Al-14Si-2Fe-0.8Mn alloy are finer and rounder than that of the Al-14Si-2Fe-0.4Mn alloy under the same pressure. The FRPs in RSC Al-14Si-2Fe-0.8Mn alloy are mainly granular particles with an average diameter of about 12 μm under 300 MPa. For the alloy with the same composition, the ultimate tensile strength (UTS) of RSC sample is higher than that of the SC sample. Under the same forming process, the UTS of Al-14Si-2Fe-0.8Mn alloy is higher than that of the Al-14Si-2Fe-0.4Mn alloy.