Unraveling the Role of Metal-Support Interactions on the Structure Sensitivity of Fischer-Tropsch Synthesis

Structure sensitivity plays a pivotal role in heterogeneous catalysis and the Fischer-Tropsch reaction is one of the prime examples of such a structure-sensitive reaction. The activity and selectivity of this reaction depend on the size of the nanoparticle and this trend is observed for a whole range of support materials. To understand why metal-support interactions do not affect this trend, a ReaxFF force field is developed that effectively mimics the broad variety of support materials and captures the metal-support interaction strength into a single structural parameter. Particles of 1-9 nm embedded on support materials are sampled using simulated annealing molecular dynamics and the effect of the metal-support interaction on the active site distribution is studied. It is found that although the size-dependency profile of various active site topologies depends on the interaction strength of the nanoparticle with the support, step-edge sites with an FCC(110) motif remain insensitive to the type of support. Based on microkinetic simulations, it is established that these sites are predominantly responsible for the observed atom-based FTS activity rationalizing why Fischer-Tropsch synthesis is structure-sensitive but support-insensitive.</p

Building, Reality, Caring: What Nurses in Three Australian Psychogeriatric Assessment Units Say about the Built Environment

Many people believe that ‘purpose-built’ facilities will diminish some of the challenging behaviours exhibited by older people with dementia or psychiatric conditions. This study aimed to explore and understand what hands-on nurses in psychogeriatric assessment units experience and think of the built environment as a part of their day to day work. Twenty-one unstructured interviews were conducted with nurses at three psychogeriatric assessment units. The units ranged in style from an ancient adapted building to a contemporary 'purpose-built' facility. A critical hermeneutics derived from Gadamer was used to explore the interviews. It found that nurses think of the built environment in relation to the care needs of their patients, and feel bureaucratic restrictions in using the built environment more keenly than the shortcomings of the built environment itself. Nurses saw themselves and their patients as 'outcasts' or victims of those with money and power. The study concludes with suggestions for challenging the status quo, but also considers that being regarded as 'outcasts' allows opportunities to avoid being overly impressed by technological marvels

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Impact of the lockdown on acute stroke treatments during the first surge of the COVID-19 outbreak in the Netherlands

INTRODUCTION: We investigated the impact of the Corona Virus Disease 2019 (COVID-19) pandemic and the resulting lockdown on reperfusion treatments and door-to-treatment times during the first surge in Dutch comprehensive stroke centers. Furthermore, we studied the association between COVID-19-status and treatment times. METHODS: We included all patients receiving reperfusion treatment in 17 Dutch stroke centers from May 11th, 2017, until May 11th, 2020. We collected baseline characteristics, National Institutes of Health Stroke Scale (NIHSS) at admission, onset-to-door time (ODT), door-to-needle time (DNT), door-to-groin time (DGT) and COVID-19-status at admission. Parameters during the lockdown (March 15th, 2020 until May 11th, 2020) were compared with those in the same period in 2019, and between groups stratified by COVID-19-status. We used nationwide data and extrapolated our findings to the increasing trend of EVT numbers since May 2017. RESULTS: A decline of 14% was seen in reperfusion treatments during lockdown, with a decline in both IVT and EVT delivery. DGT increased by 12 min (50 to 62 min, p-value of < 0.001). Furthermore, median NIHSS-scores were higher in COVID-19 - suspected or positive patients (7 to 11, p-value of 0.004), door-to-treatment times did not differ significantly when stratified for COVID-19-status. CONCLUSIONS: During the first surge of the COVID-19 pandemic, a decline in acute reperfusion treatments and a delay in DGT was seen, which indicates a target for attention. It also appeared that COVID-19-positive or -suspected patients had more severe neurologic symptoms, whereas their EVT-workflow was not affected. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-021-02539-4

A Randomized Trial of Intravenous Alteplase before Endovascular Treatment for Stroke

The value of administering intravenous alteplase before endovascular treatment (EVT) for acute ischemic stroke has not been studied extensively, particularly in non-Asian populations. METHODS We performed an open-label, multicenter, randomized trial in Europe involving patients with stroke who presented directly to a hospital that was capable of providing EVT and who were eligible for intravenous alteplase and EVT. Patients were randomly assigned in a 1:1 ratio to receive EVT alone or intravenous alteplase followed by EVT (the standard of care). The primary end point was functional outcome on the modified Rankin scale (range, 0 [no disability] to 6 [death]) at 90 days. We assessed the superiority of EVT alone over alteplase plus EVT, as well as noninferiority by a margin of 0.8 for the lower boundary of the 95% confidence interval for the odds ratio of the two trial groups. Death from any cause and symptomatic intracerebral hemorrhage were the main safety end points. RESULTS The analysis included 539 patients. The median score on the modified Rankin scale at 90 days was 3 (interquartile range, 2 to 5) with EVT alone and 2 (interquartile range, 2 to 5) with alteplase plus EVT. The adjusted common odds ratio was 0.84 (95% confidence interval [CI], 0.62 to 1.15; P=0.28), which showed neither superiority nor noninferiority of EVT alone. Mortality was 20.5% with EVT alone and 15.8% with alteplase plus EVT (adjusted odds ratio, 1.39; 95% CI, 0.84 to 2.30). Symptomatic intracerebral hemorrhage occurred in 5.9% and 5.3% of the patients in the respective groups (adjusted odds ratio, 1.30; 95% CI, 0.60 to 2.81). CONCLUSIONS In a randomized trial involving European patients, EVT alone was neither superior nor noninferior to intravenous alteplase followed by EVT with regard to disability outcome at 90 days after stroke. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups

Diagnosis and follow-up of MEN1 : Results from the DutchMEN1 study group

Multiple Endocrine Neoplasia type1 (MEN1) is a rare autosomal inherited disorder, characterized by the occurrence of primary hyperparathyroidism (pHPT), duodenopancreatic neuroendocrine tumors (dpNET), and pituitary tumors (PIT). Other tumors associated with MEN1 are lung NET, thymic NET, adrenal adenomas, and even some solid tumors such as breast cancer. MEN1 significantly impacts life-expectancy and quality of life in those affected. On average MEN1 patients have a 27 years decreased life-expectancy. Over recent decades, the follow-up and treatment of MEN1 patients has greatly improved. Still, many controversies over diagnosis, follow-up and treatment of MEN1 remain. Because of the low prevalence of MEN1, these controversies seemed difficult to investigate. In the Netherlands, care for MEN1 patients is densely centralized in eight university medical centers taking care for over 90% of MEN1 patients. The DutchMEN1 study group is an unique collaboration to improve care for MEN1 patients. The DutchMEN1 study groups database comprises longitudinal follow-up of all MEN1 patients treated in the university medical centers, enabling studies for the evidence based care for MEN1 patients. The current thesis focuses on the diagnosis and follow-up of MEN1 patients. Currently, diagnosis of MEN1 can be established by genetic testing or clinically by the presence of at least two out of three major manifestations (pHPFT, dpNET, and PIT). Patients meeting clinical criteria, without a MEN1 mutation in genetic analysis are also referred to as 'phenocopies'. Phenocopies turned out to have a completely different clinical course, only very seldomly developed a third or other associated MEN1 manifestation, and had a significantly higher life-expectancy. Further we investigated when to test patients with endocrine tumors for a MEN1 mutation. The current guidelines seem too strict and this can therefore result in a delayed diagnosis of MEN1. The age limit for the testing of patients with parathyroid adenoma of 30 years turned out to be used too strictly as a cut-off. In addition, clinicians should especially have a high index of suspicion for MEN1 if the family history of patients is positive for NETs. Follow-up in MEN1 is aimed at early detection of MEN1 associated manifestation and is performed by biochemical and radiological screening. In part two of this thesis we investigated the efficacy of the screening program in early detection of MEN1 manifestations. Biochemical tumor markers for dpNET performed poor and their use should no longer be advised for this purpose. Despite thoracic screening and early surgery premature death because of thymic NETs remains high. Given the low prevalence and incidence of thymic NETs a discussion should be started regarding the number of patients to be screened to prevent one premature death because of a thymic NET. A similar discussion should be started with regard to the frequency of follow-up CT scans. The need for early surgical interventions for MEN1 related lung NETs, given the now found relatively indolent course, should also be reconsidered. With regard to MEN1 related pituitary tumors we found that these tumors did not have a more aggressive behavior than their sporadic counterparts which was suggested in previous studies. Therefore, pituitary tumors in MEN1 patients can be followed and treated using the same guidelines as sporadically occurring pituitary tumors

Electromagnetic inverse scattering of buried objects

Electrical Engineering, Mathematics and Computer Scienc

Vaccination process of immunocompromised patients in the Netherlands: Current challenges and potential solutions

Introduction: Immunocompromised patients (ICP) have an increased risk for infectious diseases. Vaccines could help reduce this risk. However, ICP do not always receive or are reimbursed for the specific vaccinations on which they are dependent in the Netherlands. This research aims to gain insights into the current challenges in the vaccination process of ICP in the Netherlands. Moreover, it aims to explore potential solutions for these challenges and the ideal vaccination process. Methods: Twelve semi-structured interviews with relevant stakeholders were conducted. Partly based on the challenges found by the Council for Health and Society (RVS) and the Dutch National Health Care Institute (ZIN) an interview guide was developed. Results: Several newly emerged challenges were identified: fair reimbursement for the efforts of stakeholders; circular reasoning of vaccine reimbursement and guidelines; suboptimal translation from guidelines to practice and no smooth-running infrastructure. Most challenges corresponded with those stated by the RVS and ZIN. Affordability and knowledge deficit in healthcare providers and patients were the most important challenges. Rarely the same solutions were mentioned, and no ideal vaccination process emerged. Conclusions: The various challenges in the vaccination process of ICP in the Netherlands implies the difficulty to solve the problem. It is recommended to focus on solving the most important challenges. A potential solution is to adjust the GVS registration process to make it easier for the pharmaceutical industry to apply for reimbursement towards various high-risk groups. Additionally, vaccination should have a more prominent role in the education of healthcare providers. Furthermore, stakeholders need to cooperate more to solve the reimbursement and guidelines issue