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Current patterns of preventive antibiotic prescribing are encouraging the spread of antimicrobial resistance. Recently, the Spanish Society of Implants (SEI) developed the first clinical practice guidelines published to date, providing clear guidelines on how to prescribe responsible and informed preventive antibiotic therapy (PAT) based on the available scientific evidence on dental implant treatments (DIs). The present document aims to summarise and disseminate the recommendations established by this expert panel. These were based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies were analysed using the Scottish Intercollegiate Guidelines Network (SIGN) checklist templates and ranked according to their level of evidence. They were then assigned a level of recommendation using the Grading of Recommendations, Assessment, Development and Evaluation system (GRADE). Guidelines were established on the type of PAT, antibiotic and dosage of administration in the placement of DIs without anatomical constraints, in bone augmentation with the placement of DIs in one or two stages, placement of immediate DIs, sinus elevations, implant prosthetic phase, as well as recommendations in patients allergic to penicillin. Therefore, the PAT must be adapted to the type of implant procedure to be performed.

A Enfermagem, como profissão de alto desgaste físico e psicológico, tem levado alguns autores a relacionar as condições do trabalho com os altos níveis de stress. Devido à exigência da profissão, os enfermeiros estão diariamente sujeitos a situações complexas, como o envolvimento racional/emocional com os utentes, acarretando grandes níveis de responsabilidade. Assim, torna-se pertinente considerar o risco potencial dos enfermeiros de unidades críticas desenvolverem a síndrome de burnout. O objetivo desta revisão de literatura surge no sentido de ampliar o conhecimento e compreender mais detalhadamente os fatores de risco, consequências e estratégias de coping relacionadas com esta síndrome. Entre 20,8% a 31% dos profissionais de unidades críticas são alvo do burnout, o que a torna uma situação emergente. Alguns profissionais têm níveis de exigência sobre si e de controlo sobre uma situação que não corresponde à real, estas situações ocorrem onde mais existem situações limite, como nas unidades de cuidados intensivos, urgência e oncologia, que favorecem o stress intenso contínuo. A qualidade dos cuidados nos profissionais com burnout não fica assegurada, tornando-se fundamental que as organizações e o próprio indivíduo intervenham de forma a preveni-la e/ou minimizá-la, através de estratégias da própria organização e de estratégias de coping do próprio indivíduo.

Ao longo das últimas décadas, a relação dicotómica entre as ideias de reforma e revolução sofreu um crescente desequilíbrio, tornando-se a última num termo quase anacrónico e, quando muito, utópico. André Gorz foi um dos teóricos que mais se notabilizou pela resistência intelectual e política a esta tendência, problematizando estes conceitos sem, contudo, deixar de assumir uma via de saída do capitalismo. A partir da obra publicada desde meados da década de 1960 até à sua morte, em 2007, o objetivo desta investigação reside na análise dos programas políticos delineados com vista ao cumprimento deste fim. O artigo visa compreender as respetivas condições objetivas e subjetivas destas estratégias, nomeadamente as relações de trabalho; o conjunto das medidas contempladas; e o sujeito social constituinte de e constituído por tais mudanças.

O cancro colorectal é a segunda neoplasia mais frequente em homens e mulheres. Os doentes tratados apresentam um risco de recorrência elevado, pelo que o seguimento assume um papel crucial para a sua detecção precoce. As estratégias de seguimento são diferentes entre países e, dentro de cada país, entre as diferentes instituições. Em comum procuram melhorar: 1) a sobrevivência global; 2) a qualidade de vida; e 3) a razão custo/benefício. Os autores apresentam um algoritmo de seguimento para os doentes tratados por cancro colorectal, o qual assenta nos índices das recomendações da Sociedade Americana de Oncologia Médica.

This paper presents a performance evaluation of single and dual-band software-defined radio (SDR) front-ends using commercially available barium strontium titanate (BST) thin film to control SDR receivers dynamic range and mitigate interference. Firstly, an SDR front-end solution using a BST-based single-band bandpass filter (BPF) is developed to manage in-band attenuation according to the input power. Secondly, a dual-band SDR front-end to avoid high power interference with its spectral content on the below side of the second band is designed. This device is performed with a BST-based dual-band BPF providing independent control of the power limiting capabilities of the first and second bands. The BST component introduces a dependence on bias voltage, frequency, and input power. Consequently, by applying a 0 V bias, it is possible to target interferers between 700 MHz up to 1 GHz and attenuate them more than 7 dB at 40 dBm. The frequency dependence is defined by the second band, which retains its filtering performance while performing interference cancellation in the first band. This SDR solution implements a three functional dimension device in the upper MHz with a power-dependent insertion loss, high threshold power level, and frequency selectivity.

As 5G New Radio (NR) is being rolled out, research effort is being focused on the evolution of what is to come in the post-5G era. In order to meet the diverse requirements of future wireless communication in terms of increased capacity and reduced latency, technologies such as distributed massive Multiple-Input Multiple-Output (MIMO), sub-millimeter wave and Tera-hertz spectrum become technology components of interest. Furthermore, to meet the demands on connectivity anywhere at anytime, non-terrestrial satellite networks will be needed, which brings about challenges both in terms of implementation as well as deployment. Finally, scaling up massive Internet-of-Things (IoT), energy harvesting and Simultaneous Wireless Information and Power Transfer (SWIPT) is foreseen to become important enablers when deploying a large amount of small, low-power radios. In this paper, we will discuss some of the important opportunities these technologies bring, and the challenges faced by the microwave and wireless communication communities.

Vector modulators (VM) and phase shifters are essential components in phased array antennas with electronic beam steering. This work presents an IQ reflection-type vector modulator using PIN diodes, designed and implemented to operate at 28 GHz. An extensive characterization was carried out, especially concerning bandwidth and input/output return losses. This modulator is capable of producing a 360° phase shifting with a minimum attenuation of 14 dB at 28 GHz, and has a measured bandwidth of 3.6 GHz. A digital control system for the vector modulator was also developed, allowing to obtain pre-selected constellations points, with a measured 0.4 dB of maximum absolute error in amplitude and 2.6° in phase. Additionally, the designed VM was employed in a practical application, where analog beamforming is implemented in a 4 × 4 transmitter phased array allowing to perform a complete electronic control of the radiation pattern of the array.

Reconfigurable antennas play an important role in wireless communication systems as the physical and electrical properties of their structures can be modified, allowing them to be used in different applications. In this paper two reconfigurable filtennas are presented to integrate mobile devices that communicate (uplink and downlink) with satellites in low-orbit constellations. A microstrip patch antenna in uplink mode (29 GHz), is surrounded by copper structure that, once connected via a PIN diode, takes the antenna to resonate in a lower frequency band (20 GHz). To deal with both bands, two filters were integrated into the radiating structure: edge-coupled and hairpin filters. The antennas were characterized and compared through simulation and measurements, in terms of impedance adaptation, radiation pattern and isolation between operating bands, validating their operability. Their small size and low cost allow these antennas to be integrated into mobile terminals that communicate with satellites or 5G systems.

This paper presents the design, simulation, and measurement results of a dual aperture-coupled microstripline-fed antenna array with circular polarization at the C-band for small satellites applications. The antenna array was designed at a center frequency of 5.5 GHz, and it has a two-port isolation bandwidth of 25 MHz above 20 dB while the axial ratio is below 1 dB. The main objective is to produce a four-patch antenna array to be mounted on CubeSat deployable wings along with a layer of solar panels, maximizing the usable space and obtaining a better link budget for a standardized Cubesat of 10 cm × 10 cm × 10 cm. The orthogonal feedlines' isolation between Tx/Rx signals and a minimization of the multi-layer design provide a lower profile approach considering the state-of-the-art. The significant thickness reduction combined with a new perspective of having both deployable wings transmitting and receiving signals lead to a notable improvement of the overall system. This work is relevant due to the demand for high-performance antenna systems that may expand the capabilities of CubeSats, considering the importance of using an antenna array instead of a single element approach.

Fundado em 1793, o Teatro Nacional de São Carlos (TNSC) é uma referência no campo da difusão e da produção de ópera em Portugal. Considerando o período entre 1974 e 2013, o presente artigo tem como principal objetivo compreender a evolução dos vários estatutos do TNSC e das lógicas que os enformam. A partir da análise de documentação jurídica, bem como de relatórios de gestão e de monografias dedicadas à história do referido teatro, é possível identificar ao longo deste período a oscilação entre dois paradigmas: o da gestão pública, que coloca a instituição sob a alçada direta do Estado, identificando neste modelo a melhor forma de assegurar o interesse público; o da gestão privada, defendendo que a satisfação do interesse público requer a indispensável participação de receitas empresariais em domínios sob responsabilidade estatal, em nome de maior eficácia orçamental. A relação entre estas duas lógicas, como será possível verificar, decorre no quadro de processos de maior amplitude, sendo indissociável de mutações nas políticas culturais e noutras esferas da sociedade.

This paper presents a new passive vector modulator phase shifter (VMPS) based on a polar architecture suitable for use in advanced beamforming feeding networks. The cascaded structure of a reflection-type bi-phase variable attenuator (RTBVA) and a reflection-type phase shifter (RTPS) allows great flexibility regarding phase and amplitude control, and reduces amplitude errors in phase shifting. A printed circuit operating at a central frequency of 3.6 GHz with 5-bit phase resolution was designed and implemented to validate the proposed concept. The measured results showed a 360° phase shift range, an average insertion loss of 2.4 dB at 3.6 GHz, a root-mean-square phase, and a gain error of 1.3° and 0.06 dB, respectively. This VMPS also allows an amplitude control range of ~25 dB and an operational bandwidth of 0.7 GHz (19.4%).

Three-dimensional (3D) printing technology is an area of research that has received great attention in the last decade and it is pointed out by many as the future of manufacturing. 3D printing can be described as an additive process that creates a physical object from a digital model, depositing materials layer by layer. The ability to quickly produce complex structures at a reduced cost and without wasting materials is the main reason why this additive manufacturing technique is increasingly being used instead of conventional manufacturing processes. 3D printing has been applied in several scenarios, including automotive, maritime and construction industry, healthcare, as well as in the antenna research field. This paper reviews the current state-of-the-art of 3D printed antennas. Firstly, an overview of 3D printing technology is presented and then a vast number of 3D printed antennas, categorized by their construction process, are described. Finally, the main advantages and some of the limitations of using 3D printing technology in the construction of Radio Frequency (RF) structures are presented.

A condição socioprofissional dos jornalistas tem sofrido profundas transformações ao longo das últimas décadas. Estas têm origem numa sucessão de crises que afetam a comunicação social no contexto de um processo combinado de liberalização e digitalização. Além de mudanças nas rotinas de produção, as redações jornalísticas sofreram operações de reestruturação, responsáveis pela recomposição da sua força de trabalho. Entre despedimentos coletivos, aumento do desemprego, contratos a prazo, “recibos verdes”, formas descontínuas e intermitentes de trabalho, baixos salários, trabalho gratuito e a reduzido custo de estagiários, a precariedade passou, aos poucos, a caracterizar a condição jornalística. A partir dos resultados do “Estudo Sobre os Efeitos do Estado de Emergência no Jornalismo no Contexto da Pandemia Covid-19”, este artigo pretende analisar as implicações destas políticas nas relações de emprego dos jornalistas. O objetivo principal é compreender em que medida é que a resposta das empresas de comunicação social a esta nova realidade representa uma reversão da lógica de precarização ou, pelo contrário, a sua aceleração. O estudo pretende, em primeiro lugar, realizar um diagnóstico das relações de emprego antes da declaração de estado de emergência (DEE) — entre março e abril de 2020 — nomeadamente a incidência de vínculos temporários e a sua relação com fatores como o género ou a idade. Num segundo momento, analisar-se-á os efeitos da DEE a este nível, principalmente no que respeita ao recurso a contratos temporários, a despedimentos ou ao lay-off.

This article is a study on a strike of journalists, typographers and distributors that took place in Lisbon in 1921. Culminating a tension in the past years, responsible for several strikes, this event stands out either for its longevity, lasting about four months, or for gathering workers with different social conditions. From the analysis of the coverage by O Jornal, informative organ of the newspaper companies, as well as by O Século and Diário de Notícias, the aim of this research is, firstly, to demonstrate how journalistic production fits into a strategy of struggle, namely by linking the strikers to the Bolshevik regime and to the exercise of a “red censorship”. Besides aiming at their discredit, establishing such relationship served to justify the repression of trade union activity. Secondly, the text identifies differences and similarities between the discourses conveyed by the daily newspapers, thus contributing to the reflection on the distinction between informative and political journalism.