41 research outputs found

    Blood clearance and tissue distribution of PEGylated and non-PEGylated gold nanorods after intravenous administration in rats\ud

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    Aims: To develop and determine the safety of gold nanorods, whose aspect ratios can be tuned to obtain plasmon peaks between 650 and 850 nm, as contrast enhancing agents for diagnostic and therapeutic applications. Materials & methods: In this study we compared the blood clearance and tissue distribution of cetyl trimethyl ammonium bromide (CTAB)-capped and polyethylene glycol (PEG)-coated gold nanorods after intravenous injection in the tail vein of rats. The gold content in blood and various organs was measured quantitatively with inductively coupled plasma mass spectrometry. Results & discussion: The CTAB-capped gold nanorods were almost immediately (<15 min) cleared from the blood circulation whereas the PEGylation of gold nanorods resulted in a prolonged blood circulation with a half-life time of 19 h and more wide spread tissue distribution. While for the CTAB-capped gold nanorods the tissue distribution was limited to liver, spleen and lung, the PEGylated gold nanorods also distributed to kidney, heart, thymus, brain and testes. PEGylation of the gold nanorods resulted in the spleen being the organ with the highest exposure, whereas for the non-PEGylated CTAB-capped gold nanorods the liver was the organ with the highest exposure, per gram of organ. Conclusion: The PEGylation of gold nanorods resulted in a prolongation of the blood clearance and the highest organ exposure in the spleen. In view of the time frame (up to 48 h) of the observed presence in blood circulation, PEGylated gold nanorods can be considered to be promising candidates for therapeutic and diagnostic imaging purpose

    The Psychological Science Accelerator's COVID-19 rapid-response dataset

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    The psychological science accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator’s COVID-19 rapid-response dataset

    Get PDF
    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e. a controlling message) compared to no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly-internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared to the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly-internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing: Controlled motivation was associated with more defiance and less long-term behavioral intentions to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Significance Communicating in ways that motivate engagement in social distancing remains a critical global public health priority during the COVID-19 pandemic. This study tested motivational qualities of messages about social distancing (those that promoted choice and agency vs. those that were forceful and shaming) in 25,718 people in 89 countries. The autonomy-supportive message decreased feelings of defying social distancing recommendations relative to the controlling message, and the controlling message increased controlled motivation, a less effective form of motivation, relative to no message. Message type did not impact intentions to socially distance, but people’s existing motivations were related to intentions. Findings were generalizable across a geographically diverse sample and may inform public health communication strategies in this and future global health emergencies. Abstract Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    In vitro and in vivo (cyto)toxicity assays using PVC and LDPE as model materials.

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    The choice for a biomaterial is partly based on the outcome of (cyto)toxicity assays. The rationales behind the selection of certain parameters, such as cell lines, controls, and animals, were evaluated using a positive and a negative control, and one experimental sample designed to induce intermediate toxicity. Extraction and direct contact assays were performed using human epidermal keratinocytes and mouse fibroblasts and mouse epithelial cells. Cell survival was measured with the tetrazolium salt (MTT) reduction assay. In addition, local implantation studies were performed in mice and rats. The positive control induced a high degree of toxicity in all in vitro tests performed, indicating that the toxicity observed in the direct contact assay was due to in situ extraction of toxic components. In the direct contact assay the negative control tested on the mouse fibroblasts resulted in a significant reduction of cell survival. No decrease in cell survival was found using the experimental sample. Subcutaneous implantation studies in mice showed that the positive control material induced a severe degeneration in mice. However, in rats just minimal alterations were noted. The experimental material induced moderate responses only in mice. Our results indicate that the direct contact assay provides limited additional information on the cytotoxicity of materials if certain limitations are not taken into account. For the in vivo implantation assay mice were superior to rats in detecting local toxic responses

    Voeding tijdens de zwangerschap en de vatbaarheid voor chronische ziekten in het nageslacht bij de rat

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    Several epidemiological as well as experimental studies suggest that the composition of the maternal diet during pregnancy may have a programming effect on the fetus leading to epigenetic predisposition of chronic diseases in adulthood. Here, effects of various diets given during pregnancy and weaning on parameters related to chronic diseases during adulthood were studied in the rat. Seven groups of sixteen animals were put on an isocaloric semi-synthetic high-fat diet two weeks before pregnancy, and continuing throughout pregnancy and weaning. Diets differed in macronutrient - or fatty acid composition. Fetal development was studied on gestational day 21. After birth, litter size in parallel groups was reduced to eight pups. A series of physiological parameters were studied in the pups at age 12 weeks. The offspring of dams put on a low protein diet or a fish oil diet in utero and during weaning had a significantly reduced body weight gain from birth up to age 12 weeks in comparison to the control group. Male offspring aged 12 weeks fed the coconut oil diet in utero and during weaning appeared slightly insulin-resistant. No difference in the volume of the islets of Langerhans could be demonstrated in this group. Despite significantly smaller islets of Langerhans and a reduced number of large islets in the pancreas of 12-week-old male rats given the low protein diet in utero and during weaning, no differences in glucose or insulin concentration were found in comparison to the control group. Maternal diet during pregnancy and weaning did not influence immune function or blood pressure in the offspring at the age of 12 weeks. In conclusion, prenatal diet influences postnatal development, as determined by anatomical and physiological parameters.Uit zowel epidemiologische als dierexperimentele studies komen steeds meer aanwijzingen dat de samenstelling van de voeding tijdens de zwangerschap een belangrijke invloed heeft op de vatbaarheid van het nageslacht voor chronische ziekten op latere leeftijd. In deze dierexperimentele studie zijn de effecten van diervoeders met een verschillende samenstelling onderzocht op parameters voor chronische ziekten op volwassen leeftijd. Aan zeven groepen van elk zestien dieren werd een isocalorisch hoog-vet voer gegeven met een verschillende macronutrient- en vetzuursamenstelling vanaf twee weken voor de dracht tot aan het einde van de speenperiode. Op dag 21 van de dracht werd de foetale ontwikkeling onderzocht. Op de leeftijd van 12 weken is een aantal fysiologische en morfologische parameters bepaald. Nageslacht dat in utero en tijdens de speenperiode was blootgesteld aan een laag eiwit voer of een voer rijk in visvetzuren had een significant lager lichaamsgewicht vanaf de geboorte tot aan de leeftijd van 12 weken, ten opzichte van de controlegroep. Het mannelijk nageslacht van dieren van de cocosnootgroep (rijk aan verzadigde vetten) lijkt licht insuline resistent te zijn. Er was echter geen verschil in volume van de eilandjes van Langerhans ten opzichte van de controlegroep. Ondanks significant kleinere eilandjes van Langerhans en de aanwezigheid van minder grotere eilandjes in de pancreas bij 12-weken oude dieren uit de laag eiwit groep verschilde deze groep niet van de controlegroep in glucose- of insuline respons na een orale glucose load. De immuunfunctie en systolische en diastolische bloeddruk in het nageslacht op volwassen leeftijd leek niet te worden beinvloed door de samenstelling van de maternale voeding in utero en tijdens spenen Concluderend kan worden gezegd dat de samenstelling van de voeding tijdens de dracht en de vroege postnatale periode de postnatale ontwikkeling van het nageslacht beinvloedde, hetgeen bleek uit veranderingen in zowel morfologische als fysiologische parameters
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