4,255 research outputs found

    Prediction of overwash in alongshore variable barrier islands [Previsão da ocorrência de galgamentos em ilhas barreira com variabilidade longilitoral]

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    Overwash prediction is very important for coastal zone management. This work intends to identify alongshore variations in storm impact and evaluate the role of sub-aerial and submerged morphologies in overwash occurrence. For this study, 24 cross-shore topo-bathymetric profiles were set on Barreta Island (Ria Formosa barrier island system, Portugal). Pre- and post-overwash surveys were made between August 2012 and April 2013. During overwash events, tidal levels and wave parameters at breaking were obtained. Overwash occurred under storm and non-storm conditions, the latter coincident with spring high-tide. Beach morphology was spatially variable, and changeable from one overwash episode to the next. Predictions of overwash occurrence were made using the Overwash Potential, defined as the difference between runup and barrier elevation. Several runup equations were tested, and the results compared to the actual observations. The selected predictor provided an accuracy of 88% for the identification of the locations where overwash occurred. This study proves that nearshore and foreshore morphologies have a major impact on the longshore distribution of overwash.info:eu-repo/semantics/publishedVersio

    Immediate effects of acupuncture on biceps brachii muscle function in healthy and post-stroke subjects

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    <p>Abstract</p> <p>Background</p> <p>The effects of acupuncture on muscle function in healthy subjects are contradictory and cannot be extrapolated to post-stroke patients. This study evaluated the immediate effects of manual acupuncture on myoelectric activity and isometric force in healthy and post-stroke patients.</p> <p>Methods</p> <p>A randomized clinical trial, with parallel groups, single-blinded study design, was conducted with 32 healthy subjects and 15 post-stroke patients with chronic hemiparesis. Surface electromyography from biceps brachii during maximal isometric voluntary tests was performed before and after 20-min intermittent, and manual stimulation of acupoints <it>Quchi </it>(LI11) or <it>Tianquan </it>(PC2). Pattern differentiation was performed by an automated method based on logistic regression equations.</p> <p>Results</p> <p>Healthy subjects showed a decrease in the root mean-squared (RMS) values after the stimulation of LI11 (pre: 1.392 ± 0.826 V; post: 0.612 ± 0.0.320 V; <it>P </it>= 0.002) and PC2 (pre: 1.494 ± 0.826 V; post: 0.623 ± 0.320 V; <it>P </it>= 0.001). Elbow flexion maximal isometric voluntary contraction (MIVC) was not significantly different after acupuncture stimulation of LI11 (pre: 22.2 ± 10.7 kg; post: 21.7 ± 9.5 kg; <it>P </it>= 0.288) or PC2 (pre: 18.8 ± 4.6 kg; post: 18.7 ± 6.0 kg; <it>P </it>= 0.468). Post-stroke patients did not exhibit any significant decrease in the RMS values after the stimulation of LI11 (pre: 0.627 ± 0.335 V; post: 0.530 ± 0.272 V; <it>P </it>= 0.187) and PC2 (pre: 0.601 ± 0.258 V; post: 0.591 ± 0.326 V; <it>P </it>= 0.398). Also, no significant decrease in the MIVC value was observed after the stimulation of LI11 (pre: 9.6 ± 3.9 kg; post: 9.6 ± 4.7 kg; <it>P </it>= 0.499) or PC2 (pre: 10.7 ± 5.6 kg; post: 10.2 ± 5.3 kg; <it>P </it>= 0.251). Different frequency of patterns was observed among healthy subjects and post-stroke patients groups (<it>χ</it><sup>2 </sup>= 9.759; <it>P </it>= 0.021).</p> <p>Conclusion</p> <p>Manual acupuncture provides sufficient neuromuscular stimuli to promote immediate changes in motor unit gross recruitment without repercussion in maximal force output in healthy subjects. Post-stroke patients did not exhibit significant reduction on the myoelectric activity and maximal force output after manual acupuncture and needs further evaluation with a larger sample.</p> <p>Trial registration</p> <p>Brazilian Clinical Trials Registry RBR-5g7xqh.</p

    Chitosan and polyethylene glycol based membranes with antibacterial properties for tissue regeneration

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    The prevention of microbial infections associated with implantable medical devices and superficial wounds represents one of the main research strategies in the field of biomaterials. The present study reports on the development of composite membranes of Chitosan (CS)-Polyethylene glycol (PEG) matrix, incorporating particles of biphasic calcium phosphate (BCP), zinc oxide (ZnO) and copper oxide (CuO). The properties that are relevant for intended applications in tissue regeneration and antibacterial coatings of implants were assessed. It was found that the addition of 1% (w/w - relative to the mass of CS) of each metal oxide promoted satisfactory bacteriostatic activity and exhibited no cytotoxic effects towards the Vero cell line. The formation of bonds between the CS/PEG matrix and ionic species from the powders enhanced the cross-linking degree and mechanical properties of composite membranes in comparison to the non-doped membrane with the same polymer matrix (CS/PEG = 70/30%). A gradual degradation of the composite membranes over the immersion time in simulated body fluid (SBF) was accompanied by a continuous surface deposition of uniform apatite layer.publishe

    Rice quality profiling to classify germplasm in breeding programs

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    The objective of this work was to define a quality space for assessing rice varieties. Eleven long grain varieties, seven commercial and four new advanced lines were assessed to obtain complete quality profile considering appearance, physicochemical parameters, water absorption behaviour, pasting profile and textural attributes. Commercial varieties were chosen to provide the widest variation in properties, applying the variability analysis concepts of the Taguchi method, including Japonicas, Indicas, hybrids and aromatics. Quality parameters were measured in five different dimensions of quality space (totalling 50). Variable reduction techniques were applied to chose 3 parameters in each dimension (totalling 15 quality indicators) that would describe the whole space with greatest orthogonality, accuracy and yet explaining a significant proportion of the whole variance of data. The analysis of the quality space thus defined and similarities between varieties is illustrated with the conclusion of how the 4 new advanced lines perform in terms of quality behaviour, where it is concluded that one of them is very promising as an improvement over European (Indica) towards the behaviour of a pure Guyana (Indica), whereas 3 others have significant shortcomings in various aspects of the quality space compared to all others, albeit their greater closeness to Japonicas

    Propofol administration in the induction phase of general anesthesia in Portugal

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    Introdução: A administração adequada de propofol por via intravenosa durante a indução da anestesia geral implica um bom conhecimento da farmacocinética e da farmacodinâmica, um bom entendimento de como a anestesia altera a consciência e a habilidade de interpretar corretamente a monitorização dos sinais vitais. Este trabalho pretende avaliar a prática usual dos anestesiologistas em Portugal no que diz respeito à administração de propofol por via intravenosa durante a indução da anestesia geral. Material e Métodos: Estudo observacional transversal, descritivo e analítico realizado através de um questionário enviado por correio eletrónico a todos os médicos internos e especialistas em Anestesiologia de vários hospitais portugueses. O questionário apresentava um cenário convencional (Sujeito do sexo masculino, 50 anos, 60 kg, 160 cm, ASA I, submetido a anestesia geral com propofol a 1%) e incluía 10 questões relacionadas com a administração de propofol durante a indução. Foi realizada análise descritiva dos dados obtidos através do programa SPSS 23.0®. Resultados: Responderam ao inquérito 118 médicos, sendo que, a maioria eram especialistas há mais de 5 anos (56,9%). Baseados no cenário apresentado, a maioria dos anestesiologistas administraria uma dose de 60 mg de propofol na indução, a uma velocidade superior a 1200 mL/horas, avaliariam a perda de consciência através da perda do reflexo palpebral, o que se refletiria num índica BIS de 60. A maioria dos participantes medem a pressão arterial do doente a cada 5 minutos e nunca utilizaram sistemas de infusão alvo-controlada. Discussão: Os resultados do inquérito mostraram que existe uma grande variedade de métodos para avaliar a perda de consciência, uma diversidade no manuseamento e doses de propofol na indução, uma falta de experiência no uso de sistemas de infusão alvo-controlada e na avaliação da relação entre a dose, a velocidade e a concentração de propofol. Neste trabalho apresentaram-se também algumas sugestões para os anestesiologistas ponderarem implementar nas suas práticas clínicas. Conclusão: Parece haver uma diversidade na quantidade e na forma como os anestesiologistas portugueses utilizam o propofol na indução da anestesia geral.Introduction: Administering propofol intravenously adequately during induction of general anesthesia implies a good knowledge of pharmacokinetics and pharmacodynamics, a good understanding of how anesthesia alters consciousness and the ability to correctly interpret vital signs monitoring. The purpose of this study was to assess the usual practice of anesthesiologists in Portugal regarding the administration of propofol during the induction of general anesthesia. Methods: A transversal observational analytical and descriptive study, conducted through a questionnaire sent by e-mail to all anesthesiologists of several Portuguese hospitals. The questionnaire presented a conventional scenario (male subject, 50 years, 60 kg, 160 cm, ASA I, submitted to general anesthesia with 1% propofol) and has 10 questions directed to the administration of propofol during induction phase of general anesthesia. A descriptive analysis of the data was performed through SPSS 23.0®. Results: A total of 118 physicians responded to the survey, most of whom were experts for more than 5 years (56.9%). Based on the presented scenario, most anesthesiologists would administer mL/hours, and would assess loss of consciousness by evaluating loss of the eyelid reflex, which, in BIS index, would be reflected in a 60 value. Most participants measure the patient's blood pressure every 5 minutes and have never used target-controlled infusion systems. Discussion: The survey showed that there is a wide variety of methods to assess the loss of consciousness, a diversity in handling propofol in induction, a lack of experience in the use of targetcontrolled infusion systems and in the evaluation of the relationship between dose, velocity and concentration of propofol. In this work, some suggestions were also made for anesthesiologists to consider implementing in their clinical practices. Conclusion: There seems to be a diversity in the amount and in the way propofol is used by the Portuguese anesthesiologists to induce general anesthesia.Foundation for Science and Technology ((FCT), Portugal, for the PhD Scholarship SFRH/BD/98915/2013 and for the project UID/ SEM/50022/2013.info:eu-repo/semantics/publishedVersio

    OPTIMIZATION OF ZIRCONIA INKS TO FABRICATE 3D POROUS SCAFFOLDS BY ROBOCASTING

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    High-performance bioceramics such as zirconia, alumina, and their composites, are attractive materials for the fabrication of load-bearing bone implants because of their outstanding mechanical properties, biocompatibility, corrosion resistance, and aesthetic quality. A suitable level of porosity and pore sizes with a few hundred microns are required for a good bone integration of the scaffolds. This requirement can be achieved through additive manufacturing, like robocasting. For this purpose, the optimization of colloidal inks is one of paramount importance as the rheological properties of the inks determine the quality of the three-dimensional structures. This target has not been satisfactorily accomplished in previous research works. The present study aims at closing this gap by carrying out a systematic investigation about the influence of the most important parameters that determine the printing ability of zirconia inks. The dispersing ability of the zirconia powder was studied in order to maximize the solids loading while keeping a high degree of homogeneity of the starting suspensions. The viscoelastic properties of the suspensions were then altered by adding suitable doses of a coagulating agent to obtain easily extrudable pastes for the robocasting process. The green samples were dried and sintered at the heating rate of 1ºC/min up to 600ºC, an holding at this temperature for 1 h, followed by an heating rate of 5ºC/min up to 1350ºC and holding for 1 h at this temperature, and then cooling down to room temperature. Zirconia inks with high fraction of solids (48 vol.%) could be successfully prepared. The extruded cylinders exhibited an excellent shape retention in scaffolds with different macropore sizes (200, 300, 400 and 500 mm)

    Occupational risk in a glass manufacturing industry unit

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    Risk assessment is one of the main pillars of the framework directive and other directives in respect of health and safety. It is also the basis of an effective management of safety and health as it is essential to reduce work-related accidents and occupational diseases. To survey the hazards eventually present in the workplaces the usual procedures are i) gathering information about tasks/activities, employees, equipment, legislation and standards; ii) observation of the tasks and; iii) quantification of respective risks through the most adequate risk assessment among the methodologies available. From this preliminary evaluation of a welding plant and, from the different measurable parameters, noise was considered the most critical. This paper focus not only the usual way of risk assessment for noise but also another approach that may allow us to identify the technique with which a weld is being performed
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