100 research outputs found

    Millimeter-wave FET modeling based on a frequency extrapolation approach

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    An empirical distributed model, based on electromagnetic analysis and standard S-parameter measurements up to microwave frequencies, is shown to be capable of accurate small-signal predictions up to the millimeter-wave range. The frequency-extrapolation approach takes advantage from a physically-expected, smooth behavior of suitably defined elementary active devices connected to a passive distributed network. On this basis, small-signal millimeter-wave FET modeling becomes an affordable task in any laboratory equipped with a standard microwave vector network analyzer and electromagnetic simulation capabilities. In the paper, wide experimental validation of the proposed model up to 110GHz is presented for PHEMT devices with different sizes and bias conditions

    Global modeling approach to the design of an MMIC amplifier using Ohmic Electrode-Sharing Technology

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    An innovative technique for high--density, high-frequency integrated circuit design is proposed.The procedure exploits the potentialities of a global modeling approach,previously applied only at device level,enabling the circuit designer to explore flexible layout solutions imed at important reduction in chip size and cost.The new circuit design technique is presented by means of an example consisting of a wide-band amplifier,implemented with the recently proposed Ohmic Electrode-Sharing Technology (OEST).The good agreement between experimental and simulated results confirms the validity of the proposed MMIC design approach

    How can advance care planning support hope in patients with advanced cancer and their families: a qualitative study as part of the international ACTION trial

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    Objective Clinicians' fears of taking away patients' hope is one of the barriers to advance care planning (ACP). Research on how ACP supports hope is scarce. We have taken up the challenge to specify ways in which ACP conversations may potentially support hope. Methods In an international qualitative study, we explored ACP experiences of patients with advanced cancer and their personal representatives (PRs) within the cluster-randomised control ACTION trial. Using deductive analysis of data obtained in interviews following the ACP conversations, this substudy reports on a theme of hope. A latent thematic analysis was performed on segments of text relevant to answer the research question. Results Twenty patients with advanced cancer and 17 PRs from Italy, the Netherlands, Slovenia, and the United Kingdom were participating in post-ACP interviews. Three themes reflecting elements that provide grounds for hope were constructed. ACP potentially supports hope by being (I) a meaningful activity that embraces uncertainties and difficulties; (II) an action towards an aware and empowered position; (III) an act of mutual care anchored in commitments. Conclusion Our findings on various potentially hope supporting elements of ACP conversations provide a constructive way of thinking about hope in relation to ACP that could inform practice

    Advance care planning in patients with advanced cancer: A 6-country, cluster-randomised clinical trial

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    Background Advance care planning (ACP) supports individuals to define, discuss, and record goals and preferences for future medical treatment and care. Despite being internationally recommended, randomised clinical trials of ACP in patients with advanced cancer are scarce. Methods and findings To test the implementation of ACP in patients with advanced cancer, we conducted a cluster-randomised trial in 23 hospitals across Belgium, Denmark, Italy, Netherlands, Slovenia, and United Kingdom in 2015–2018. Patients with advanced lung (stage III/IV) or colorectal (stage IV) cancer, WHO performance status 0–3, and at least 3 months life expectancy were eligible. The ACTION Respecting Choices ACP intervention as offered to patients in the intervention arm included scripted ACP conversations between patients, family members, and certified facilitators; standardised leaflets; and standardised advance directives. Control patients received care as usual. Main outcome measures were quality of life (operationalised as European Organisation for Research and Treatment of Cancer [EORTC] emotional functioning) and symptoms. Secondary outcomes were coping, patient satisfaction, shared decision-making, patient involvement in decision-making, inclusion of advance directives (ADs) in hospital files, and use of hospital care. In all, 1,117 patients were included (442 intervention; 675 control), and 809 (72%) completed the 12-week questionnaire. Patients’ age ranged from 18 to 91 years, with a mean of 66; 39% were female. The mean number of ACP conversations per patient was 1.3. Fidelity was 86%. Sixteen percent of patients found ACP conversations distressing. Mean change in patients’ quality of life did not differ between intervention and control groups (T-score −1.8 versus −0.8, p = 0.59), nor did changes in symptoms, coping, patient satisfaction, and shared decision-making. Specialist palliative care (37% versus 27%, p = 0.002) and AD inclusion in hospital files (10% versus 3%, p < 0.001) were more likely in the intervention group. A key limitation of the study is that recruitment rates were lower in intervention than in control hospitals. Conclusions Our results show that quality of life effects were not different between patients who had ACP conversations and those who received usual care. The increased use of specialist palliative care and AD inclusion in hospital files of intervention patients is meaningful and requires further study. Our findings suggest that alternative approaches to support patient-centred end-of-life care in this population are needed

    Trained facilitators’ experiences with structured advance care planning conversations in oncology : an international focus group study within the ACTION trial

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    Background In oncology, Health Care Professionals often experience conducting Advance Care Planning (ACP) conversations as difficult and are hesitant to start them. A structured approach could help to overcome this. In the ACTION trial, a Phase III multi-center cluster-randomized clinical trial in six European countries (Belgium, Denmark, Italy, the Netherlands, Slovenia, United Kingdom), patients with advanced lung or colorectal cancer are invited to have one or two structured ACP conversations with a trained facilitator. It is unclear how trained facilitators experience conducting structured ACP conversations. This study aims to understand how facilitators experience delivering the ACTION Respecting Choices (RC) ACP conversation. Methods A qualitative study involving focus groups with RC facilitators. Focus group interviews were recorded, transcribed, anonymized, translated into English, and thematically analysed, supported by NVivo 11. The international research team was involved in data analysis from initial coding and discussion towards final themes. Results Seven focus groups were conducted, involving 28 of in total 39 trained facilitators, with different professional backgrounds from all participating countries. Alongside some cultural differences, six themes were identified. These reflect that most facilitators welcomed the opportunity to participate in the ACTION trial, seeing it as a means of learning new skills in an important area. The RC script was seen as supportive to ask questions, including those perceived as difficult to ask, but was also experienced as a barrier to a spontaneous conversation. Facilitators noticed that most patients were positive about their ACTION RC ACP conversation, which had prompted them to become aware of their wishes and to share these with others. The facilitators observed that it took patients substantial effort to have these conversations. In response, facilitators took responsibility for enabling patients to experience a conversation from which they could benefit. Facilitators emphasized the need for training, support and advanced communication skills to be able to work with the script. Conclusions Facilitators experienced benefits and challenges in conducting scripted ACP conversations. They mentioned the importance of being skilled and experienced in carrying out ACP conversations in order to be able to explore the patients’ preferences while staying attuned to patients’ needs

    Content analysis of Advance Directives completed by patients with advanced cancer as part of an Advance Care Planning intervention: insights gained from the ACTION trial

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    Purpose: Writing an Advance Directive (AD) is often seen as a part of Advance Care Planning (ACP). ADs may include specific preferences regarding future care and treatment and information that provides a context for healthcare professionals and relatives in case they have to make decisions for the patient. The aim of this study was to get insight into the content of ADs as completed by patients with advanced cancer who participated in ACP conversations. Methods: A mixed methods study involving content analysis and descriptive statistics was used to describe the content of completed My Preferences forms, an AD used in the intervention arm of the ACTION trial, testing the effectiveness of the ACTION Respecting Choices ACP intervention. Results: In total, 33% of 442 patients who received the ACTION RC ACP intervention completed a My Preferences form. Document completion varied per country: 10.4% (United Kingdom), 20.6% (Denmark), 29.2% (Belgium), 41.7% (the Netherlands), 61.3% (Italy) and 63.9% (Slovenia). Content analysis showed that ‘maintaining normal life’ and ‘experiencing meaningful relationships’ were important for patients to live well. Fears and worries mainly concerned disease progression, pain or becoming dependent. Patients hoped for prolongation of life and to be looked after by healthcare professionals. Most patients preferred to be resuscitated and 44% of the patients expressed maximizing comfort as their goal of future care. Most patients preferred ‘home’ as final place of care. Conclusions: My Preferences forms provide some insights into patients’ perspectives and preferences. However, understanding the reasoning behind preferences requires conversations with patients

    Missing not at random in end of life care studies: multiple imputation and sensitivity analysis on data from the ACTION study

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    Background: Missing data are common in end-of-life care studies, but there is still relatively little exploration of which is the best method to deal with them, and, in particular, if the missing at random (MAR) assumption is valid or missing not at random (MNAR) mechanisms should be assumed. In this paper we investigated this issue through a sensitivity analysis within the ACTION study, a multicenter cluster randomized controlled trial testing advance care planning in patients with advanced lung or colorectal cancer. Methods: Multiple imputation procedures under MAR and MNAR assumptions were implemented. Possible violation of the MAR assumption was addressed with reference to variables measuring quality of life and symptoms. The MNAR model assumed that patients with worse health were more likely to have missing questionnaires, making a distinction between single missing items, which were assumed to satisfy the MAR assumption, and missing values due to completely missing questionnaire for which a MNAR mechanism was hypothesized. We explored the sensitivity to possible departures from MAR on gender differences between

    A Scalable PHEMT Model Taking Into Account Electromagnetic and Electro-Thermal Effects

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    The paper proposes an approach to model a P-HEMT taking into account for the electrical-thermal- electromagnetic behavior in an effective way.The model is based on the integration of a distributed approach,which considers an intrinsic device for gate finger,each of them equipped with a thermal equivalent circuit.The latter considers also the mutual interacting between the adjacent intrinsic devices by means a voltage-controlled voltage- source that allows considering the thermal coupling by a series of coefficients determined in an analytical way.The electrical model has been extracted from a 2x150um PHEMT and then applied to predict the DC and RF characteristic of a 8x150um proving the model scalability capability
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