74 research outputs found
Design of automotive VCSEL transmitter with on-chip feedforward optical power control
We propose a novel 50 Mb/s optical transmitter fabricated in a 0.6 mu m BiCMOS technology for automotive applications. The proposed VCSEL driver chip was designed to operate with a single Supply voltage ranging from 3.0 V to 5.25 V. A fully integrated feedforward current control circuit is presented to stabilize the optical output power without any external components. The experimental results show that the optical output power can be stable within a 1.1 dB range and the extinction ratio greater than 14 dB over the automotive environmental temperature range of -40 degrees C to 105 degrees C
The role of oxygen vacancies in SrTiO3 at the LaAlO3/SrTiO3 interface
Strontium titanate, SrTiO3, a widely used substrate material for electronic
oxide thin film devices, has provided many interesting features. In a
combination with a similar oxide material, LaAlO3, it has recently received
great interest. It was suggested that two-dimensional electron gas is formed at
the interface between SrTiO3 and LaAlO3, resulting in high electrical
conductivity and mobility. In this report we demonstrate that the transport
properties in those heterostructures are very sensitive to the deposition
parameters during thin film growth. Using cathode- and photoluminescence
studies in conjunction with measurements of electrical transport properties and
microstructure we show that the electronic properties observed at a
LaAlO3/SrTiO3 interface can be explained by oxygen reduced SrTiO3. In addition,
we demonstrate that oxygen can be pushed in and out of the sample, but that
re-oxygenation of an initially oxygen depleted LaAlO3/SrTiO3 heterostructure is
partly prevented by the presence of the film.Comment: 19 pages, 5 figure
Lifestyle behaviour and risk factor control in coronary patients : Belgian results from the cross-sectional EUROASPIRE surveys
Objective: The aim of this study was to assess lifestyle behaviour as well as risk factor management across Belgian coronary patients who participated in the cross-sectional European Action on Secondary Prevention through Intervention to Reduce Events (EUROASPIRE) surveys.
Methods: Analyses are based on a series of coronary patients by combining data from the Belgian participants in the EUROASPIRE III (328 patients; in 2006-2007) and EUROASPIRE IV (343 patients; in 2012-2013) surveys. Four hospitals located in the Ghent area participated in the surveys. Patients included in the analyses were >= 18 years old and had been hospitalised for a coronary event. Information on cardiovascular risk factors, lifestyle behaviour and medical treatment were obtained.
Results: Overall, the proportion of smokers was 11% with 40% persistent smokers. Adequate physical activity levels were reported by 17%, 28% of patients were obese, 47% was central obese and known diabetes was prevalent in 21% of patients. Hypertension was observed in 46% of patients and 20% had a total cholesterol >= 5 mmol/L. About 80% had participated in a cardiac rehabilitation programme and the majority of patients were treated with blood pressure (92%) or lipid-lowering drugs (92%). Anxiety and depressive symptoms were reported by 30% and 24%, respectively. Differences between EUROASPIRE III and IV were limited.
Conclusions: Compared to the overall EUROASPIRE results in Europe, Belgian CHD patients seem to do slightly better. However, tackling obesity, physical inactivity, hypertension and psychosocial distress remains an important challenge in the management of coronary patients
Building a Global Ecosystem Research Infrastructure to Address Global Grand Challenges for Macrosystem Ecology
The development of several large-, "continental"-scale ecosystem research infrastructures over recent decades has provided a unique opportunity in the history of ecological science. The Global Ecosystem Research Infrastructure (GERI) is an integrated network of analogous, but independent, site-based ecosystem research infrastructures (ERI) dedicated to better understand the function and change of indicator ecosystems across global biomes. Bringing together these ERIs, harmonizing their respective data and reducing uncertainties enables broader cross-continental ecological research. It will also enhance the research community capabilities to address current and anticipate future global scale ecological challenges. Moreover, increasing the international capabilities of these ERIs goes beyond their original design intent, and is an unexpected added value of these large national investments. Here, we identify specific global grand challenge areas and research trends to advance the ecological frontiers across continents that can be addressed through the federation of these cross-continental-scale ERIs.Peer reviewe
Proof-of-concept trial results of the HeartMan mobile personal health system for self-management in congestive heart failure
This study tested the effectiveness of HeartMan—a mobile personal health system offering decisional support for management of congestive heart failure (CHF)—on health-related quality of life (HRQoL), self-management, exercise capacity, illness perception, mental and sexual health. A randomized controlled proof-of-concept trial (1:2 ratio of control:intervention) was set up with ambulatory CHF patients in stable condition in Belgium and Italy. Data were collected by means of a 6-min walking test and a number of standardized questionnaire instruments. A total of 56 (34 intervention and 22 control group) participants completed the study (77% male; mean age 63 years, sd 10.5). All depression and anxiety dimensions decreased in the intervention group (p < 0.001), while the need for sexual counselling decreased in the control group (p < 0.05). Although the group differences were not significant, self-care increased (p < 0.05), and sexual problems decreased (p < 0.05) in the intervention group only. No significant intervention effects were observed for HRQoL, self-care confidence, illness perception and exercise capacity. Overall, results of this proof-of-concept trial suggest that the HeartMan personal health system significantly improved mental and sexual health and self-care behaviour in CHF patients. These observations were in contrast to the lack of intervention effects on HRQoL, illness perception and exercise capacity
Defining Responses to Therapy and Study Outcomes in Clinical Trials of Invasive Fungal Diseases: Mycoses Study Group and European Organization for Research and Treatment of Cancer Consensus Criteria
Invasive fungal diseases (IFDs) have become major causes of morbidity and mortality among highly immunocompromised patients. Authoritative consensus criteria to diagnose IFD have been useful in establishing eligibility criteria for antifungal trials. There is an important need for generation of consensus definitions of outcomes of IFD that will form a standard for evaluating treatment success and failure in clinical trials. Therefore, an expert international panel consisting of the Mycoses Study Group and the European Organization for Research and Treatment of Cancer was convened to propose guidelines for assessing treatment responses in clinical trials of IFDs and for defining study outcomes. Major fungal diseases that are discussed include invasive disease due to Candida species, Aspergillus species and other molds, Cryptococcus neoformans, Histoplasma capsulatum, and Coccidioides immitis. We also discuss potential pitfalls in assessing outcome, such as conflicting clinical, radiological, and/or mycological data and gaps in knowledg
Heart re-transplantation in Eurotransplant
Internationally 3% of the donor hearts are distributed to re-transplant patients. In Eurotransplant, only patients with a primary graft dysfunction (PGD) within 1 week after heart transplantation (HTX) are indicated for high urgency listing. The aim of this study is to provide evidence for the discussion on whether these patients should still be allocated with priority. All consecutive HTX performed in the period 1981-2015 were included. Multivariate Cox' model was built including: donor and recipient age and gender, ischaemia time, recipient diagnose, urgency status and era. The study population included 18 490 HTX, of these 463 (2.6%) were repeat transplants. The major indications for re-HTX were cardiac allograft vasculopathy (CAV) (50%), PGD (26%) and acute rejection (21%). In a multivariate model, compared with first HTX hazards ratio and 95% confidence interval for repeat HTX were 2.27 (1.83-2.82) for PGD, 2.24 (1.76-2.85) for acute rejection and 1.22 (1.00-1.48) for CAV (P < 0.0001). Outcome after cardiac re-HTX strongly depends on the indication for re-HTX with acceptable outcomes for CAV. In contrast, just 47.5% of all hearts transplanted in patients who were re-transplanted for PGD still functioned at 1-month post-transplant. Alternative options like VA-ECMO should be first offered before opting for acute re-transplantation
Analysis of small-angle X-ray scattering data in the presence of significant instrumental smearing
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