Physician and nurse knowledge about patient radiation exposure in the emergency department

Background: Imaging methods that use ionizing radiation in emergency departments (EDs) have increased with advances in radiological diagnostic methods. Physician and nurse awareness of the radiation dose in the ED and the associated cancer risks to which the patients are exposed were surveyed with a questionnaire.Methods: A total of 191 subjects in six EDs participated in this study. ED physicians and ED nurses were asked about the risks and the radiation doses of imaging methods ordered in the ED. The differences between the two groups were compared using Student’s t‑test for continuous variables. A Fisher’s exact and Chi‑squared tests were used for categorical variables.Results: A total of 82 ED physicians and 109 ED nurses completed the questionnaire; 38 (46.3%) physicians and 8 (7.3%) nurses correctly answered the question about the chest X‑ray radiation dose. A question about the number of chest X‑rays that is equivalent to the dose of a pelvic X‑ray was answered correctly by 5 (6.1%) physicians and 9 (8.3%) nurses (P = 0.571). Questions regarding abdominal computed tomography (CT), chest CT, brain CT, abdominal ultrasonography, and brain magnetic resonance imaging were answered correctly more frequently by the physician group than the nurse group (P < 0.05). The risk of developing cancer over a lifetime due to a brain CT was correctly answered by 21 (25.6%) physicians and 30 (27.5%) nurses (P = 0.170). A similar question regarding abdominal CT was correctly answered by 21 (25.6%) physicians and 42 (38.5%) nurses (P = 0.127).Conclusions: Knowledge of the radiation exposure of radiology examinations was lower in nurses than physicians, but knowledge was poor in both groups. ED physicians and nurses should be educated about radiation exposure and cancer risks associated with various diagnostic radiological methods.Keywords: Diagnostic imaging, emergencies, radiation dosag

Studying the effect of sonographic landmarks imaged on transcutaneous laryngeal ultrasonography on perioperative vocal cord assessment

Scientific Session 8INTRODUCTION: Transcutaneous laryngeal ultrasound (TLUSG) is a non-invasive way of assessing vocal cord (VC) function. During examination, the assessor often looks at 3 sonographic landmarks (namely, false VC (FC), true VC (TC) and arytenoids (AR)) to ascertain VC movement. However, it is unclear among these landmarks, which one provides the most reliable VC assessment as not all patients would have all three landmarks identified on the same examination. We postulated that perhaps finding all three sonographic landmarks may further improve diagnostic accuracy. To address these questions, we prospectively evaluated consecutive patients over two institutions …published_or_final_versio

Fouling and its control in membrane distillation-A review

© 2014 Elsevier B.V. Membrane distillation (MD) is an emerging thermally-driven technology that poses a lot of promise in desalination, and water and wastewater treatment. Developments in membrane design and the use of alternative energy sources have provided much improvement in the viability of MD for different applications. However, fouling of membranes is still one of the major issues that hounds the long-term stability performance of MD. Membrane fouling is the accumulation of unwanted materials on the surface or inside the pores of a membrane that results to a detrimental effect on the overall performance of MD. If not addressed appropriately, it could lead to membrane damage, early membrane replacement or even shutdown of operation. Similar with other membrane separation processes, fouling of MD is still an unresolved problem. Due to differences in membrane structure and design, and operational conditions, the fouling formation mechanism in MD may be different from those of pressure-driven membrane processes. In order to properly address the problem of fouling, there is a need to understand the fouling formation and mechanism happening specifically for MD. This review details the different foulants and fouling mechanisms in the MD process, their possible mitigation and control techniques, and characterization strategies that can be of help in understanding and minimizing the fouling problem

Can net photosynthesis and water relations provide a clue on the forest decline of Quercus suber in North Tunisia?

Net photosynthesis, sap flow density (SFD) and water use efficiency (WUE) were measured in a Quercus suber forest in north Tunisia in an attempt to explain the forest decline. In general, sap flow was positively related to light intensity and water loss, indicating that high light intensities can increase the SFD up to the saturation point in the cork oak. CO2 assimilation of cork oak in this region was light intensity-dependent. Cork oak showed a general increase in photosynthetic rates with increasing light intensity up to the light saturation point. Increased radiation probably increased the photosynthesis and growth above ground in this area, whereas the below-ground soil had insufficient moisture for uptake through the roots because the high light intensity and temperature induced high evapotranspiration.Key words: Decline, evaportranspiration, light intensity, Quercus suber, sap flow density, water use efficiency

Characteristics of biochemical markers and quality parameters using whole wheat flours in Korean wheat cultivars and lines

Tese de doutoramento em Ciências e Tecnologias da Informação, apresentada ao Departamento de Engenharia Informática da Faculdade de Ciências e Tecnologia da Universidade de CoimbraO espectro rádio tem vindo a ser regulado de um modo estático. Ou seja, este encontra-se essencialmente dividido em bandas de frequência licenciadas, com utilização restringida a um número limitado de utilizadores autorizados, e em algumas bandas de frequência não licenciadas para utilização livre. Devido à falta de flexibilidade resultante desta abordagem, partes significativas do espectro rádio encontram-se subutilizadas. Em simultâneo, outras bandas de frequência estão a ficar cada vez mais saturadas, nomeadamente as não licenciadas em áreas densamente povoadas. O Rádio Cognitivo é um paradigma recente cujo objetivo é melhorar o nível de eficiência na utilização do espectro rádio. Os seus princípios gerais consistem em permitir que dispositivos sem fios não licenciados (os denominados Utilizadores Secundários) possam aceder às bandas de frequência licenciadas desde que estes não interferiram de forma prejudicial com os utilizadores licenciados (os denominados Utilizadores Primários). A abordagem preponderante na área de Rádio Cognitivo consiste em ter utilizadores secundários com capacidade para, de um modo dinâmico, detetar e aceder a oportunidades espectrais, ou seja, bandas de frequência que não estão a ser acedidas pelos respetivos utilizadores primários num determinado momento numa determinada localização. Neste contexto, os utilizadores secundários devem ser capazes de analisar o espectro rádio com precisão e, de preferência, possuírem mecanismos de aprendizagem baseados em observação local e experiência passada. Apesar da área de Rádio Cognitivo ter implicações na totalidade das camadas das pilhas protocolares de comunicação, os seus problemas fundamentais localizam-se nos níveis físico (PHY) e de controlo de acesso ao meio (MAC). Em particular, os protocolos de controlo de acesso ao meio desempenham um papel fundamental no âmbito de operações de controlo de acesso ao espectro rádio e de suporte à cooperação entre utilizadores secundários. Os utilizadores primários, quanto a eles, devem manter-se abstraídos das operações de Rádio Cognitivo e, em consequência, não estarem sujeitos a qualquer tipo de alteração em cenários de Rádio Cognitivo. Esta tese apresenta cinco contribuições, essencialmente relacionadas com o nível do controlo de acesso ao meio, com o objetivo de incrementar os níveis de proteção dos utilizadores primários e de desempenho dos utilizadores secundários em redes de Rádio Cognitivo distribuídas, especialmente quando os utilizadores secundários não têm antecipadamente acesso a qualquer tipo de informação, tal como a localização de utilizadores primários. Neste tipo de cenário, não existe qualquer entidade central responsável por recolher e processar dados de origem diversa ou tomar decisões de acesso ao espectro rádio. Ou seja, as soluções propostas adequam-se a utilizadores secundários que operam de um modo autónomo e cooperativo. Estes tomam as suas decisões baseando-se, essencialmente, em observações locais, em eventuais resultados de aprendizagem e em dados trocados entre si. A primeira contribuição desta tese consiste numa descrição da área de Rádio Cognitivo através de um estado da arte detalhado. A segunda contribuição resulta na definição de um protocolo de controlo de acesso ao meio apoiado num mecanismo inovador, designado COSBET (Cooperative Sense-Before-Transmit), que oferece um nível superior de proteção dos utilizadores primários em cenários de Rádio Cognitivo distribuídos sujeitos ao problema do utilizador primário oculto. Este tipo de anomalia ocorre quando um utilizador secundário é incapaz de detetar as atividades de um determinado utilizador primário apesar de poder provocar interferências na respetiva área de abrangência. Tal como já foi referido, na área de Rádio Cognitivo, é considerado desejável os utilizadores secundários terem capacidades de aprendizagem baseadas em observação local e experiência passada. No entanto, em cenários distribuídos, o problema do utilizador primário oculto afeta negativamente a qualidade dos resultados de aprendizagem obtidos e, em consequência, o nível efetivamente alcançado em termos de proteção dos utilizadores primários. Sendo assim, esta tese também analisa esta questão e propõe uma solução destinada a tratá-la, estando esta terceira contribuição baseada num conceito chave designado FIBASC (Filtering Based on Suspicious Channels). A troca de informação de controlo em redes de Rádio Cognitivo distribuídas é frequentemente suportada por um canal partilhado e acessível à globalidade dos utilizadores secundários. Este é o designado canal de controlo comum (CCC), sendo igualmente esta a abordagem seguida pelo protocolo COSBET-MAC proposto. No entanto, os CCC estão sujeitos a problemas de saturação. A ocorrência deste tipo de problema impede os utilizadores secundários de tirarem pleno proveito das potencialidades oferecidas pelo Rádio Cognitivo, acabando por limitar os níveis de desempenho de comunicação alcançáveis. Sendo assim, nesta tese também analisamos esta questão e propomos uma solução destinada a abordá-la, correspondendo esta à nossa quarta contribuição. A solução proposta, designada CORHYS (Cognitive Radio Hybrid Signalling), baseia-se num esquema de sinalização híbrido que recorre simultaneamente a um CCC e aos canais de dados que vão sendo alocados de forma dinâmica. A quinta e última contribuição desta tese consiste na definição de uma estratégia adicional, igualmente localizada no nível do controlo de acesso ao meio, destinada a melhorar o desempenho dos utilizadores secundários em cenários de Rádio Cognitivo distribuídos em que se recorre a um CCC. Fazem parte das suas linhas orientadoras a otimização da reutilização espacial do espectro rádio e a redução do tráfego de controlo gerado entre utilizadores secundários. As soluções de Rádio Cognitivo propostas no âmbito desta tese foram avaliadas em ambiente de simulação, sendo esta uma prática comum, nomeadamente devido a limitações de tempo e de outros tipos de recursos. Para o efeito, recorreu-se ao OMNET++ (Objective Modular Network Testbed in C++), um simulador baseado em eventos discretos e de código aberto. A totalidade das contribuições da presente tese podem ser aplicadas em conjunto. A integração destas deu origem a uma solução única e otimizada de controlo de acesso ao meio destinada a cenários de Rádio Cognitivo distribuídos. Esta aborda as duas principais preocupações existentes em cenários de Rádio Cognitivo: proteger os utilizadores primários de qualquer tipo de interferência prejudicial; e melhorar o desempenho de comunicação dos utilizadores secundários. Tanto quanto sabemos, as várias soluções propostas e o nível de completude que a utilização conjunta destas permite não são oferecidos por qualquer outra proposta de controlo de acesso ao meio existente para cenários de Rádio Cognitivo distribuídos. As contribuições desta tese também apontam direções que podem ser seguidas no âmbito de outros protocolos de controlo de acesso ao meio, especialmente aqueles que se destinam a redes de Rádio Cognitivo distribuídas.The radio spectrum has been statically regulated, i.e., essentially partitioned into licensed frequency bands, which are accessed exclusively by authorized users, and unlicensed frequency bands that can be freely accessed. Due to this inflexible policy, large portions of the entire radio spectrum remain unused independently of time and location in the world, while some frequency bands suffer from increasing levels of saturation, particularly the unlicensed ones in densely populated areas. Cognitive Radio (CR) is a recent paradigm that aims at improving efficiency regarding spectrum utilization. Its principles consist in allowing unlicensed wireless devices (i.e., secondary users) to access licensed frequency bands provided that the respective incumbent users (i.e., primary users) do not suffer any harmful interference. The most preponderant CR approach consists in having a secondary user (SU) dynamically locating and accessing spectrum opportunities, i.e., frequency bands that are not being accessed by any primary user (PU) at a given time and location. Consequently, sensing the spectrum and learning through local observation and past experience, which enables proactive spectrum decision, are key CR issues. Despite CR has implications in all the layers of the communication protocol stack, its fundamentals are mainly related to the physical (PHY) and medium access control (MAC) levels. In fact, CR MAC protocols are at the heart of spectrum access control and cooperation between SUs. PUs are expected to be unware of CR operations and, consequently, should not suffer any modification under CR scenarios. This thesis provides five contributions, essentially related to the MAC level, with the aim of improving the protection of PUs and the communication performance of SUs in cooperative distributed CR networks, particularly when there is no access to any a priori known information, such as the locations of primary transmitters. In this type of scenario, there are no central entities that collect and fuse data, or take spectrum decisions. That is, the proposed solutions fit into totally autonomous and cooperating SUs, i.e., SUs that take their own decisions based on local observation, on learning outcomes if any is available, and on data they exchange with each other. The first contribution of this thesis consists in a description of the CR area through an indepth state of the art. The second contribution lies in the definition of a CR MAC protocol that follows a novel approach, named Cooperative Sense-Before-Transmit (COSBET), which provides a higher protection of PUs in distributed CR scenarios that suffer from the hidden PU problem. This issue occurs when a SU cannot sense the activities of a given PU despite it can cause harmful interference to its coverage area. As already mentioned, CR considers that the SUs might have learning capabilities based on local observation and past experience. However, in distributed scenarios, the hidden PU problem affects the accuracy of learning and, therefore, the effectiveness of PU protection. For that reason, in this thesis we also discuss this issue and propose a novel solution that addresses it. This solution is based on a key concept named FIBASC (Filtering Based on Suspicious Channels). Utilizing a common control channel (CCC), i.e., a channel that is available to all the SUs in a CR network, for signalling purposes is a frequent practice concerning existing distributed CR MAC solutions. It is also the solution adopted by COSBET-MAC. However, a CCC is susceptible to saturation and can, therefore, become a performance bottleneck that inhibits the SUs from taking full advantage of CR potentialities. Consequently, the fourth contribution of this thesis consists in analysing this issue and addressing it through a novel solution, which we named CORHYS (Cognitive Radio Hybrid Signalling). CORHYS is based on a hybrid signalling approach that performs signalling over the CCC and over the allocated data channels simultaneously. The fifth and last contribution of this thesis consists in a MAC-level strategy that aims at further improving the performance of SUs in distributed CR scenarios that are based on a CCC. The key guidelines for this strategy are optimizing the spatial reuse of the radio spectrum and reducing control traffic. The CR solutions that resulted from this thesis were evaluated through simulation, which is a common practice, particularly due to time and other resource restrictions. For this purpose, we used OMNET++ (Objective Modular Network Testbed in C++), an open source discrete event simulator. The contributions of this thesis can be applied jointly and were successfully integrated with each other, which resulted in an optimized CR MAC solution that addresses the two main concerns in distributed CR scenarios: protecting the PUs from harmful interference; and improving the communication performance of the SUs. To the best of our knowledge, the proposed solutions and the level of completeness that they jointly achieve are not found in any other existing distributed CR MAC proposal. We also note that they define directions that can be followed by other CR MAC protocols, particularly those that target distributed CR networks

Trends in prevalence and mortality of dementia in elderly Hong Kong population: projections, disease burden, and implications for long term care

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Dementia Trends: Impact of the Ageing Population and Societal Implications for Hong Kong

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The clinical usefulness of initial serum procalcitonin as an aggravation predictor in a hepatobiliary tract infection at emergency department

Background and Objectives: The ability to predict future clinical deterioration early in patients who present to an emergency care center with a hepatobiliary tract infection is difficult. We studied the clinical usefulness of the initial serum levels of procalcitonin in a hepatobiliary tract infection as an indicator for predicting aggravation in the early stages.Methods: Of the patients who presented with the clinical symptoms of a hepatobiliary tract infection, 99 were diagnosed with a hepatobiliary tract infection by imaging studies and subsequently enrolled in the study. Laboratory tests were obtained in the early stage of disease after presentation to an emergency care center. We assessed and compared the serum levels of many early inflammatory markers (white blood cell [WBC] counts, C‑reactive protein and procalcitonin) between patients whose symptoms were initially stable upon arrival to an emergency care center but then deteriorated to, those whose symptoms remained consistently stable. Thus, we examined if the above serum markers are useful in predicting the possibility of future symptom aggravation.Results: Of a total of 99 patients, 27 were assigned to the symptom aggravation group. The serum levels of WBC counts and C‑reactive protein in the aggravation group were elevated. However, the median value (interquartile range) of procalcitonin was relatively increased at 2.28 (0.41–7.84 ng/ml), demonstrating a significant difference.Conclusions: In conclusion, initial serum levels of procalcitonin might be used as an indicator for aggravation in patients with hepatobiliary tract infection at the emergency department, even though there is hemodynamic stability.Key words: Hepatobiliary tract, infection, procalcitoni