2,003 research outputs found

    How metal films de-wet substrates - identifying the kinetic pathways and energetic driving forces

    Full text link
    We study how single-crystal chromium films of uniform thickness on W(110) substrates are converted to arrays of three-dimensional (3D) Cr islands during annealing. We use low-energy electron microscopy (LEEM) to directly observe a kinetic pathway that produces trenches that expose the wetting layer. Adjacent film steps move simultaneously uphill and downhill relative to the staircase of atomic steps on the substrate. This step motion thickens the film regions where steps advance. Where film steps retract, the film thins, eventually exposing the stable wetting layer. Since our analysis shows that thick Cr films have a lattice constant close to bulk Cr, we propose that surface and interface stress provide a possible driving force for the observed morphological instability. Atomistic simulations and analytic elastic models show that surface and interface stress can cause a dependence of film energy on thickness that leads to an instability to simultaneous thinning and thickening. We observe that de-wetting is also initiated at bunches of substrate steps in two other systems, Ag/W(110) and Ag/Ru(0001). We additionally describe how Cr films are converted into patterns of unidirectional stripes as the trenches that expose the wetting layer lengthen along the W[001] direction. Finally, we observe how 3D Cr islands form directly during film growth at elevated temperature. The Cr mesas (wedges) form as Cr film steps advance down the staircase of substrate steps, another example of the critical role that substrate steps play in 3D island formation

    Validation report which details the advanced models developed to describe a) static and continuous and b) dynamic force transfer standards taking into account sensitivity stability, temperature and other parasitic influences on the measurement uncertainty (target uncertainty is 1 % up to 100 Hz and 2 % between 100 - 1000 Hz)

    Get PDF
    Current document reports on the development and validation of advanced practical models for describing force measuring devices used for the measurement of static, continuous forces in part A as well as dynamic forces in part B of the report. In the force measurement applications, the sensitivity curve of the force measuring devices determined in the calibration gives the traceability to national standards. The measurement uncertainty in an application is mainly affected by the sensitivity stability, the influence of temperature and other parasitic components. To capture these effects an advanced model for static and continuous forces was developed in part A which describes these influences especially in respect of their contribution to the measurement uncertainty. In contrast to the static calibration procedure, the dynamic calibration of the sensor has been always challenging because of several reasons such as the sophisticated nature of dynamic measurement, insufficient structural equipment, and parasitic effects which yield higher measurement uncertainty in comparison to static measurements and therefore inappropriate characterization of the force transducers. To close this knowledge gap in the dynamic calibration, the advanced model for dynamic forces was developed in part B. To consider the dynamic properties of force measuring devices the frequency dependency of the sensitivity and the influence of parasitic influences from temperature of the force measuring devices was considered and described. The target uncertainty is 1 % for up to 100 Hz and the target uncertainty is 2 % for higher frequency range from 100 Hz up to 1000 Hz

    Stakeholders' perspectives on a patient-reported outcome measure-based drug safety monitoring system for immune-mediated inflammatory diseases

    Get PDF
    Background: Biologics are used as effective therapeutics to treat a variety of diseases. Even though biologics are widely used, knowledge on the post-marketing experience of patients is limited. Therefore, a framework was established for a patient-reported outcome measure (PROM)-based drug safety monitoring system for ADRs attributed to biologics, known as the ‘Dutch Biologic Monitor’. Objective: Generation of a multi-stakeholder perspective on the preferred setup, potential and added value of a PROM-based national drug safety monitoring system. Methods: Nineteen stakeholders were interviewed following a structured interview guide. Transcribed data were coded and analyzed to count frequencies and to generate recurring themes. Results: Stakeholders (84.2%) support the establishment of a national drug safety monitoring system, but the feasibility depends on the implementation process. The need for integration and assessment of PROMs on ADRs in clinical practice and the preference to monitor small molecules and new drugs were emphasized. Preferably, all pharmacological options per indication should be monitored. Conclusions: Stakeholders recommend to establish a PROM-based national drug safety monitoring system focused on ADRs attributed to biologics, small molecules, and new drugs. Moreover, PROMs on ADRs ideally need to become integrated in clinical practice to provide health-care providers more insight in patients’ perspectives

    High-resolution Local Gravity Model of the South Pole of the Moon from GRAIL Extended Mission Data

    Get PDF
    We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6deg by 1/6deg (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40deg. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models

    Total body topical 5-fluorouracil for extensive non-melanoma skin cancer

    Get PDF
    Background Topical 5-fluorouracil 5% cream is one of the treatment modalities for non-melanoma skin cancer (NMSC). There is a lack of suitable therapies to treat patients with extensive NMSC. In this paper we report two patients with extensive NMSC treated by total body application of topical 5-fluorouracil 5% cream. Observations Topical 5-fluorouracil 5% cream was applied twice daily to the total body, including normal appearing skin. During the treatment, weekly blood samples were taken for measurement of 5-fluorouracil levels. All samples showed a 5-fluorouracil level less than the detection level of 10 mu g/l. Total body 5-fluorouracil 5% cream was shown to be an effective treatment in our patients; the majority of lesions cleared in both patients. Conclusions In conclusion, total body topical 5-fluorouracil 5% cream application was successful in two patients with extensive NMSC. No detectable serum level of 5-fluorouracil could be determined. Pain and secondary infections were important side effects in our patients. However, in patients with extensive NMSC this treatment may be considered

    Global and Local Gravity Field Models of the Moon Using GRAIL Primary and Extended Mission Data

    Get PDF
    The Gravity Recovery and Interior Laboratory (GRAIL) mission was designed to map the structure of the lunar interior from crust to core and to advance the understanding of the Moon's thermal evolution by producing a high-quality, high-resolution map of the gravitational field of the Moon. The mission consisted of two spacecraft, which were launched in September 2011 on a Discovery-class NASA mission. Ka-band tracking between the two satellites was the single science instrument, augmented by tracking from Earth using the Deep Space Network (DSN)

    Immune-mediated inflammatory disease patients' preferences in adverse drug reaction information regarding biologics

    Get PDF
    Objectives: Patient-reported outcomes (PROs) are increasingly used in studies and medical practice to obtain information on patients’ perspectives toward their treatment or disease. However, most study outcomes are primarily directed at healthcare professionals. It was aimed to obtain insight in which type of information immune-mediated inflammatory disease (IMID) patients prefer to receive after participating in the Dutch Biologic Monitor (DBM), a PRO-based prospective cohort event monitoring system focused on adverse drug reactions (ADRs). Methods: A survey was conducted among DBM participants that wanted information about the results. Patients’ preferences were identified using twelve statements and rated with five-point Likert-type scales. Subgroup analyses and differences between statements were performed using Mann-Whitney U Tests. Results: The survey was completed by 591 patients (response rate 67.6%). Most respondents had inflammatory rheumatic diseases (76.8%) and used adalimumab (37.2%) or etanercept (33.2%). Respondents preferred results per IMID over aggregated results (p = <0.001). Information on whether patients with similar IMIDs experience ADRs (average 4.5), which biologics are most likely to cause ADRs (4.4) and whether ADRs disappear (4.4) were most interesting. Conclusion: DBM participants prefer to receive disease-specific information on ADRs that is tailored to their own biologic and IMID, including the outcome of ADRs

    Gastrointestinal adverse drug reaction profile of etanercept:Real world data from patients and healthcare professionals

    Get PDF
    Objective. We aimed to describe the nature and frequency of gastrointestinal adverse drug reactions (GI-ADRs) of etanercept (ETN) using patient-reported and healthcare professional (HCP)-registered data and compared this frequency with the GI-ADR frequency of the widely used tumor necrosis factor-α inhibitor adalimumab (ADA). Methods. Reported GI-ADRs of ETN for rheumatic diseases were collected from the Dutch Biologic Monitor and DREAM registries. We described the clinical course of GI-ADRs and compared the frequency with ADA in both data sources using Fisher exact test. Results. Out of 416 patients using ETN for inflammatory rheumatic diseases in the Dutch Biologic Monitor, 25 (6%) patients reported 36 GI-ADRs. In the DREAM registries 11 GI-ADRs were registered for 9 patients (2.3%), out of 399 patients using ETN, with an incidence of 7.1 per 1000 patient-years. Most GI-ADRs consisted of diarrhea, nausea, and abdominal pain. GI-ADRs led to ETN discontinuation in 1 patient (4%) and dose adjustment in 4 (16%) in the Dutch Biologic Monitor. Eight GI-ADRs (73%) led to ETN discontinuation in the DREAM registries. The frequency of GI-ADRs of ETN did not significantly differ from GI-ADRs of ADA in both data sources (Dutch Biologic Monitor: ETN 8.7% vs ADA 5.3%, P = 0.07; DREAM: ETN 2.8% vs ADA 4.7%, P = 0.16). Conclusion. Most GI-ADRs associated with ETN concerned gastrointestinal symptoms. These ADRs may lead to dose adjustment or ETN discontinuation. The frequency of ETN-associated GI-ADRs was comparable to the frequency of ADA-associated GI-ADRs. Knowledge about these previously unknown ADRs can facilitate early recognition and improve patient communication
    corecore