27 research outputs found

    Increasing flood risk awareness and warning readiness by participation – But who understands what under ‘participation’?

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    Participation is an often-demanded process in disaster risk reduction (DRR). However, it is often unclear who understands what under this term. International organizations such as the United Nations have promoted participation in their DRR strategies since the 1980s, but further research is needed on its opportunities and limitations. Here we highlight what is understood by participation according to different actors and various international contexts. This study was motivated by a workshop where flood-risk and resilience experts from 14 countries perceived the nature of participation and the lack of its implementation differently. To unravel the multitude of these perspectives, 27 expert interviews were conducted in seven countries: Belgium, Germany, Indonesia, Iran, Nepal, Pakistan and Peru between March and August 2020. Results show that constraints on the conduction of participation are not only related to the specific country context but differ even within countries. Limitations such as capacities and willingness to participate as well as the role and importance of participation are common issues across the investigated contexts and countries

    Comparison between microcatheter and nebulizer for generating Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)

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    BACKGROUND: This study compares an endoscopic microcatheter and a nebulizer for delivering Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC). METHODS: This is an in vitro and ex vivo study in an established model (inverted bovine urinary bladder). Four parameters were compared to determine the performance of a micro-perforated endoscopic spray catheter vs. state-of-the art, nozzle technology: (1) surface coverage and pattern with methylene blue on blotting paper at three different distances; (2) median aerodynamic diameter (MAD) of aerosol droplets with three different solutions (H(2)O, Glc 5% and silicon oil); (3) depth of tissue penetration of doxorubicin (DOX) and (4) tissue concentration of cisplatin (CIS) and DOX using standard clinical solutions. RESULTS: The spray area covered by the microcatheter was larger (p < 0.001) but its pattern was inhomogenous than with the nozzle technology. We found that aerosol droplets were larger in the test group than in the control group for all three solutions tested. Median tissue penetration of DOX was lower (980 ”m) with the microcatheter than with the nebulizer (1235 ”m) and distribution was more heterogeneous ( = 0.003) with the microcatheter. The median tissue concentration of DOX and CIS was lower and concentration of DOX was more heterogeneous with the microcatheter (p = 0.002). CONCLUSIONS: This investigation has revealed that microcatheter technology generates larger aerosol droplet size, less drug tissue penetration and lower drug tissue concentration than the current nozzle technology. In the absence of clinical studies, use of microcatheters for delivering PIPAC can not be recommended at this stage

    Biological Performance of Titanium Surfaces with Different Hydrophilic and Nanotopographical Features

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    The micro- and nanostructures, chemical composition, and wettability of titanium surfaces are essential for dental implants’ osseointegration. Combining hydrophilicity and nanostructure has been shown to improve the cell response and to shorten the healing time. This study aimed to investigate the biological response to different wettability levels and nanotopographical modifications in aged and non-aged titanium surfaces. By plasma etching titanium surfaces with the fluorine gas 2,3,3,3-tetrafluoropropene (R1234yF), additional nanostructures were created on the sample surfaces. Furthermore, this treatment resulted in sustained superhydrophilicity and fluoride accumulation. We examined the effect of various nanostructuring processes and aging using scanning electron microscopy, roughness analyses, and wettability measurement. In addition, all the surface modifications were tested for their effects on fibroblast adhesion, proliferation, and viability as well as osteoblast differentiation. Our study indicates that the plasma etching, with 2,3,3,3-tetrafluoropropene, of the machined and SLA surface neither favored nor had an adverse effect on the biological response of the SAOS-2 osteoblast cell line. Although the fluorine-plasma-etched surfaces demonstrated improved fibroblast cell viability, they did not lead to improved early osseointegration. It is still unclear which surface properties mainly influence fibroblast and osteoblast adhesion. Further physiochemical aspects, such as electrostatic interaction and surface tension, are crucial to be analyzed along with wettability and roughness

    Surface-Mediated Modulation of Different Biological Responses on Anatase-Coated Titanium

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    Various surface modification strategies are being developed to endow dental titanium implant surfaces with micro- and nano-structures to improve their biocompatibility, and first of all their osseointegration. These modifications have the potential to address clinical concerns by stimulating different biological processes. This study aims to evaluate the biological responses of ananatase-modified blasted/etched titanium (SLA-anatase) surfaces compared to blasted/acid etched (SLA) and machined titanium surfaces. Using unipolar pulsed direct current (DC) sputtering, a nanocrystalline anatase layer was fabricated. In vitro experiments have shown that SLA-anatase discs can effectively promote osteoblast adhesion and proliferation, which are regarded as important features of a successful dental implant with bone contact. Furthermore, anatase surface modification has been shown to partially enhance osteoblast mineralization in vitro, while not significantly affecting bacterial colonization. Consequently, the recently created anatase coating holds significant potential as a promising candidate for future advancements in dental implant surface modification for improving the initial stages of osseointegration

    Dronabinol has preferential antileukemic activity in acute lymphoblastic and myeloid leukemia with lymphoid differentiation patterns

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    Proapoptotic effect of THC is mediated via the mitochondrial intrinsic pathway. Western immunoblotting of cleaved caspase 9 in Jurkat cells treated with THC is shown. Tubulin serves as a loading control. (TIFF 107 kb

    Ultrastructural alterations in the retinal pigment epithelium and photoreceptors of a Stargardt patient and three Stargardt mouse models: indication for the central role of RPE melanin in oxidative stress

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    Background Stargardt disease (SD) is characterized by the accumulation of the age-pigment lipofuscin in the retinal pigment epithelium (RPE) and subsequent neuroretinal degeneration. The disease leads to vision loss early in life. Here, we investigate age-dependent ultrastructural changes in three SD mouse models: albino Abca4-/- and pigmented Abca4-/- and Abca4-/-.Rdh8-/- mice. Since we found indications for oxidative stress primarily in albino SD mice, we tested RPE melanin for its antioxidative capabilities. Methods SD mouse eyes were investigated by light, fluorescence and electron microscopy and were compared to the respective albino and pigmented wild type mice and to a human donor SD eye. To confirm the role of RPE melanin in scavenging oxidative stress, melanin from S. officinalis as a standard and porcine RPE were tested for their capability to quench superoxide anions. Results Histological alterations indicative of oxidative stress and/or lysosomal dysfunction were present in albino Abca4-/- and Abca4-/-.Rdh8-/- mice. Retinal damage, such as inner segment rupture and pyknotic or free photoreceptor nuclei in the subretinal space and RPE vacuolization were exclusively found in albino Abca4-/- mice. Shortened and disorganized photoreceptor outer segments and dead RPE cells were found in albino Abca4-/- and Abca4-/-.Rdh8-/- mice, with earlier onset in albino Abca4-/- mice. Undegraded phagosomes and lipofuscin accumulation were present in the RPE of all three SD strains, but numbers were highest in Abca4-/-.Rdh8-/- mice. Lipofuscin morphology differed between SD strains: (melano-)lipofuscin granules in pigmented Abca4-/- mice had a homogenous electron density and sharp demarcations, while lipofuscin in albino Abca4-/- mice had a flocculent electron density and often lacked a surrounding membrane, indicating loss of lysosomal integrity. Young Abca4-/-.Rdh8-/- mice showed (melano-)lipofuscin granules with homogenous electron density, while in aged animals granules with flocculent electron density predominated. Both strains of pigmented SD mice had melanolipofuscin clusters as found in the human SD eye. Like melanin from S. officinalis, porcine RPE melanin can also quench superoxide anions. Discussion The presented pathologies in albino Abca4-/- and Abca4-/-.Rdh8-/- mice suggest oxidative stress and/or lysosomal dysfunction within the RPE. Since albino Abca4-/- mice have the earliest onset and severest damage and as absence of melanin and also melanin turnover with age are known to diminish RPEs anti-oxidative properties, we assume that RPE melanin plays a role in SD related damages. A lack of pathology in pigmented Abca4-/- mice due to lower stress levels as compared to the Abca4-/-.Rdh8-/- mice underlines this hypothesis. It is also supported by the finding that RPE melanin can quench superoxide anions. We therefore suppose that RPE melanin is important in retinal health and we discuss its role as an oxidative stress scavenger

    Fundus autofluorescence, spectral-domain optical coherence tomography, and histology correlations in a Stargardt disease mouse model

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    Stargardt disease (STGD1), known as inherited retinal dystrophy, is caused by ABCA4 mutations. The pigmented Abca4-/- mouse strain only reflects the early stage of STGD1 since it is devoid of retinal degeneration. This blue light-illuminated pigmented Abca4-/- mouse model presented retinal pigment epithelium (RPE) and photoreceptor degeneration which was similar to the advanced STGD1 phenotype. In contrast, wild-type mice showed no RPE degeneration after blue light illumination. In Abca4-/- mice, the acute blue light diminished the mean autofluorescence (AF) intensity in both fundus short-wavelength autofluorescence (SW-AF) and near-infrared autofluorescence (NIR-AF) modalities correlating with reduced levels of bisretinoid-fluorophores. Blue light-induced RPE cellular damage preceded the photoreceptors loss. In late-stage STGD1-like patient and blue light-illuminated Abca4-/- mice, lipofuscin and melanolipofuscin granules were found to contribute to NIR-AF, indicated by the colocalization of lipofuscin-AF and NIR-AF under the fluorescence microscope. In this mouse model, the correlation between in vivo and ex vivo assessments revealed histological characteristics of fundus AF abnormalities. The flecks which are hyper AF in both SW-AF and NIR-AF corresponded to the subretinal macrophages fully packed with pigment granules (lipofuscin, melanin, and melanolipofuscin). This mouse model, which has the phenotype of advanced STGD1, is important to understand the histopathology of Stargardt disease
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