high performance microwave waveguide devices produced by laser powder bed fusion process

Abstract Additive manufacturing technologies are currently envisaged to boost the development of a next generation of microwave devices intended for satellite telecommunications. Due to their excellent electromagnetic and mechanical properties, metal waveguide components are key building blocks of several radio frequency (RF) systems used in these applications. This article reports the perspectives deriving from the use of laser powder bed fusion (L-PBF) technology to the production of high-performance microwave waveguide devices. A robust design of filters has been implemented in several prototypes manufactured in AlSi10Mg alloy. The corresponding measured performance confirm the applicability of the L-PBF process to the intended application

3D Printing of a Monolithic K/Ka-Band Dual-Circular Polarization Antenna-Feeding Network

In this paper, a Ka/K-band antenna-feeding network in dual-circular polarization is reported. The design of the system was carried out in view of its monolithic manufacturing through selective laser melting in AlSi10Mg alloy. As a proof-of-concept for satellite telecommunication multi-beam applications, the feeding network operates in the K band (19.25, 20.75) GHz and in the Ka band (27.0, 29.0) GHz. The system provides four rectangular-waveguide ports and a common dual-polarized circular-waveguide port to be connected to the feed horn. The prototype exhibits measured values of in-band return loss better than 28 dB and a port-to-port isolation better than 19 dB (in polarization) and 50 dB (in frequency). The cross-polar discrimination is higher than 20 dB. In this regard, an elliptical-waveguide line was specifically designed and manufactured to recover a value higher than 30 dB in both frequency bands. The line can be easily integrated in the feed horn to be connected to the feeding-network thanks the ease of customization provided by 3D printing. The insertion losses are lower than 0.5 and 0.2 dB in the K and Ka bands, respectively. The weight of the prototype is approximately 130 g

Latin America and the Caribbean code against cancer: Developing evidence-based recommendations to reduce the risk of cancer in Latin America and the Caribbean

Latin America and the Caribbean (LAC) has a population of more than 650 million inhabitants (8.5% of the world population),1 with a cancer incidence of more than 1.4 million new patients and more than 670,000 deaths in 2018. These figures will increase by 78% by 2040 to more than 2.5 million people diagnosed with cancer each year, and these patients will require medical attention, care, and support. However, many of these new cancer diagnoses can be prevented through public policies, supportive environments, and lifestyles that promote health and prevent cancer (Fig 1).2 In the LAC region, there are many organizations and institutions providing information on cancer prevention, including national cancer institutes, cancer societies and foundations, and public health agencies. Nevertheless, the information is frequently confusing, overwhelming, or even contradictory. The scientific source and credibility, as well as the primary message, differ according to the type of organization that provides the information (eg, patient organization, scientific or governmental institution).For the LAC region, a coalition of institutions and international organizations has joined forces to adapt the European Code to the cancer risks and situation in the LAC region. This involves collecting, analyzing, and evaluating the scientific evidence to support suitable cancer prevention recommendations to the LAC context. A multistakeholder participation in the project is a key approach to ensure that all players will be owners of the Code and true promoters. The coalition is composed of the Pan-American Health Organization (PAHO; also part of the WHO) and the IARC as leading international organizations; a Scientific Committee of senior researchers and distinguished leaders in cancer prevention from LAC; and an Advocacy Group representing important organizations in LAC, including the Latin American and Caribbean Society of Medical Oncology, the Network of Latin-American Cancer Institutes, the Healthy Caribbean Coalition, and the Association of Latin American Leagues Against Cancer.Fil: Cazap, Eduardo. Sociedad Latinoamericana y del Caribe de Oncología Médica; ArgentinaFil: de Almeida, Liz Maria. Instituto Nacional de Câncer Brasil Jose Alencar Gomes da Silva; BrasilFil: Arrossi, Silvina. Centro de Estudios de Estado y Sociedad; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García, Patricia J.. Universidad Cayetano Heredia; PerúFil: Garmendia, María Luisa. Universidad de Chile; ChileFil: Gil, Enrique. South America Pan-American Health Organization; PerúFil: Hassel, Trevor. Healthy Caribbean Coalition; BarbadosFil: Mayorga, Rubén. South America Pan-American Health Organization; PerúFil: Mohar, Alejandro. Universidad Nacional Autónoma de México; MéxicoFil: Murillo, Raúl. Centro Javeriano de Oncología; ColombiaFil: Owen, Gabriel O.. Healthy Caribbean Coalition; BarbadosFil: Paonessa, Diego. Liga Argentina de Lucha contra el Cancer; ArgentinaFil: Santamaría, Julio. Centro Hemato Oncológico Panamá; PanamáFil: Tortolero Luna, Guillermo. Universidad de Puerto Rico; Puerto RicoFil: Zoss, Walter. Red de Institutos e Instituciones Nacionales de Cancer; BrasilFil: Herrero, Rolando. Agencia Internacional para la Investigación del Cáncer; FranciaFil: Luciani, Silvana. Pan-American Health Organization; Estados UnidosFil: Schüz, Joachim. Agencia Internacional para la Investigación del Cáncer; FranciaFil: Espina, Carolina. Agencia Internacional para la Investigación del Cáncer; Franci

3D-Printing of Antenna-Feed Components for Space Applications

This paper reports an overview on the on-going research activity aimed at the exploitation of 3D-printing technologies to the development of dual-band and dual-polarization components for SatCom antenna feed chains. In particular, architectures optimized for 3D-printing are discussed, and the results of a preliminary study on the application of perforations along the internal channels is reported

"Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 ± 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

Objectives: Few studies have analyzed factors associated with delirium subtypes. In this study, we investigate factors associated with subtypes of delirium only in patients with dementia to provide insights on the possible prevention and treatments. Design: This is a cross-sectional study nested in the \u201cDelirium Day\u201d study, a nationwide Italian point-prevalence study. Setting and Participants: Older patients admitted to 205 acute and 92 rehabilitation hospital wards. Measures: Delirium was evaluated with the 4-AT and the motor subtypes with the Delirium Motor Subtype Scale. Dementia was defined by the presence of a documented diagnosis in the medical records and/or prescription of acetylcholinesterase inhibitors or memantine prior to admission. Results: Of the 1057 patients with dementia, 35% had delirium, with 25.6% hyperactive, 33.1% hypoactive, 34.5% mixed, and 6.7% nonmotor subtype. There were higher odds of having venous catheters in the hypoactive (OR 1.82, 95% CI 1.18-2.81) and mixed type of delirium (OR 2.23, CI 1.43-3.46), whereas higher odds of urinary catheters in the hypoactive (OR 2.91, CI 1.92-4.39), hyperactive (OR 1.99, CI 1.23-3.21), and mixed types of delirium (OR 2.05, CI 1.36-3.07). We found higher odds of antipsychotics both in the hyperactive (OR 2.87, CI 1.81-4.54) and mixed subtype (OR 1.84, CI 1.24-2.75), whereas higher odds of antibiotics was present only in the mixed subtype (OR 1.91, CI 1.26-2.87). Conclusions and Implications: In patients with dementia, the mixed delirium subtype is the most prevalent followed by the hypoactive, hyperactive, and nonmotor subtype. Motor subtypes of delirium may be triggered by clinical factors, including the use of venous and urinary catheters, and the use of antipsychotics. Future studies are necessary to provide further insights on the possible pathophysiology of delirium in patients with dementia and to address the optimization of the management of potential risk factors