200 research outputs found

    Dutch Immigrant Memoirs and Related Writings

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    Review of Dutch Immigrant Memoirs and Related Writings, by Henry S. Lucas

    Structural Response of Shells to Shock and Detonation Loading

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    Part I: theory. Part II: shock loading of a thin aluminum tube. Part III: the GALCIT detonation tube

    Smart shops: a survey of products, claimed effects and medical-toxicological relevance

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    During the last few years the use of herbal drugs of abuse, so-called 'smart products' and eco-drugs has increased. Many of these products have psychoactive effects. The variety of smart products sold in the so-called smart shops is enormous and this is still a growing market. The increased availability of these products and the continuing appearance of new products on the market, has led to increased awareness of the possible negative health aspects associated with the use of these products. At present, the Dutch Inspectorate for Health Protection, Commodities and Veterinary Public Health is testing the activities of these smart shops and the products for adherence to the regulations. This document, prepared by the National Poisons Control Centre (NVIC) of the National Institute of Public Health and the Environment (RIVM), serves as a practical aid to the Inspectorate in evaluating the various smart products. Four important groups of smart products can be discerned: the energizers, relaxing herbs, aphrodisiacs and products with hallucinogenic properties. For each of these groups the following items are described: the various product appearances, usage, the (desired) effects of the product according to smart shop information brochures, a description of the original plants (most of these products are derived from plants), the active ingredients in the product, and to the best of our knowledge, the pharmacology and medical toxicology of these ingredients and products. Further monitoring of the use of these smart products and the health effects they cause, should make clear to which specific group of smart products most attention should be paid from a medical point of view.Het gebruik van zogenaamde smartproducts en eco-drugs neemt de laatste jaren steeds meer toe. Het aanbod van producten die in de smartshops worden verkocht is zeer divers. Veel van de aangeboden middelen hebben psychoactieve effecten. Bovendien is het een uiterst dynamische markt, waar regelmatig nieuwe producten ontwikkeld en verkocht worden. Door deze groeiende markt wordt ook van overheidswege aandacht besteed aan de gezondheids- en maatschappelijke risico's van het gebruik en de verkoop van deze middelen. In het huidige beleid ten aanzien van deze middelen ligt de nadruk op gezondheidsbescherming met behulp van voorlichting, monitoring en onderzoek. In dit kader toetst in 1999 de Inspectie Gezondheidsbescherming, Waren en Veterinaire Zaken de activiteiten van smartshops en andere verkooppunten, alsmede de verhandelde waar, aan de warenwettelijke kaders. Zonodig wordt nieuwe jurisprudentie opgebouwd. Dit rapport, geschreven op verzoek van en in samenwerking met de Inspectie Gezondheidsbescherming, Waren en Veterinaire Zaken dient de Inspectie tot een praktisch hulpmiddel bij het evalueren van de vele verschillende producten die op de markt aanwezig zijn. Op grond van het belangrijkste beoogde effect dat deze middelen na gebruik zouden verschaffen, zijn de producten ingedeeld in een van de vier te onderscheiden functionele groepen, te weten de "energizers", "relaxing herbs", "afrodisiaca" en "hallucinogene producten". Per product(-groep) worden besproken: de verschillende productvoorkomens en wijze van gebruik, het in de smartshop gepropageerde doel van gebruik, de plantaardige herkomst van het product, en de samenstellende verbindingen met voor zover bekend hun farmacologische werkingsmechanismen en toxiciteit. Daarbij is gebruik gemaakt van de humaan medisch-toxicologische kennis zoals die op dit moment voorhanden is. Verdere monitoring naar de effecten van het gebruik zal inzichtelijk moeten maken naar welke productgroepen vanuit medisch oogpunt in de toekomst de meeste aandacht zal moeten uitgaan

    Transcriptional signatures of somatic neoblasts and germline cells in <i>Macrostomum lignano</i>

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    The regeneration-capable flatworm <i>Macrostomum lignano</i> is a powerful model organism to study the biology of stem cells in vivo. As a flatworm amenable to transgenesis, it complements the historically used planarian flatworm models, such as <i>Schmidtea mediterranea</i>. However, information on the transcriptome and markers of stem cells in <i>M. lignano</i> is limited. We generated a de novo transcriptome assembly and performed the first comprehensive characterization of gene expression in the proliferating cells of <i>M. lignano</i>, represented by somatic stem cells, called neoblasts, and germline cells. Knockdown of a selected set of neoblast genes, including <i>Mlig-ddx39</i>, <i>Mlig-rrm1</i>, <i>Mlig-rpa3</i>, <i>Mlig-cdk1</i>, and <i>Mlig-h2a</i>, confirmed their crucial role for the functionality of somatic neoblasts during homeostasis and regeneration. The generated <i>M. lignano</i> transcriptome assembly and gene expression signatures of somatic neoblasts and germline cells will be a valuable resource for future molecular studies in <i>M. lignano</i>

    High-content high-throughput imaging reveals distinct connections between mitochondrial morphology and functionality for oxphos complex I, III, and V inhibitors

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    Cells can adjust their mitochondrial morphology by altering the balance between mitochondrial fission and fusion to adapt to stressful conditions. The connection between a chemical perturbation, changes in mitochondrial function, and altered mitochondrial morphology is not well understood. Here, we made use of high-throughput high-content confocal microscopy to assess the effects of distinct classes of oxidative phosphorylation (OXPHOS) complex inhibitors on mitochondrial parameters in a concentration and time resolved manner. Mitochondrial morphology phenotypes were clustered based on machine learning algorithms and mitochondrial integrity patterns were mapped. In parallel, changes in mitochondrial membrane potential (MMP), mitochondrial and cellular ATP levels, and viability were microscopically assessed. We found that inhibition of MMP, mitochondrial ATP production, and oxygen consumption rate (OCR) using sublethal concentrations of complex I and III inhibitors did not trigger mitochondrial fragmentation. Instead, complex V inhibitors that suppressed ATP and OCR but increased MMP provoked a more fragmented mitochondrial morphology. In agreement, complex V but not complex I or III inhibitors triggered proteolytic cleavage of the mitochondrial fusion protein, OPA1. The relation between increased MMP and fragmentation did not extend beyond OXPHOS complex inhibitors: increasing MMP by blocking the mPTP pore did not lead to OPA1 cleavage or mitochondrial fragmentation and the OXPHOS uncoupler FCCP was associated with OPA1 cleavage and MMP reduction. Altogether, our findings connect vital mitochondrial functions and phenotypes in a high-throughput high-content confocal microscopy approach that help understanding of chemical-induced toxicity caused by OXPHOS complex perturbing chemicals.Toxicolog

    Quietly sharing the load? The role of school psychologists in enabling teacher resilience

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    Teacher resilience is associated with positive student outcomes and plays an important role in teacher retention and well-being. School ecologies can enable the resilience of teachers, with prior research illustrating the importance of supportive colleagues, strong leadership, and positive school culture. There is limited research, however, exploring the role of school psychologists in supporting or enabling teacher resilience. Using data from experienced Australian school psychologists and teachers, this exploratory qualitative study examines the role of school psychologists in enabling teacher resilience. Findings show that school psychologists directly and indirectly support teacher resilience, although teachers perceive school psychologists’ main role as work with individual students. Issues pertaining to variations in access and particular roles of school psychologists are discussed. Although further research is needed to clarify and promote the role of school psychologists, this study points to them potentially playing an important role in school ecologies that enable teacher resilience

    Treatment of bulky lymph nodes in locally advanced cervical cancer:boosting versus debulking

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    Objective: Treatment strategies for bulky lymph nodes in patients with locally advanced cervical cancer scheduled for definitive chemoradiation include nodal boosting with radiotherapy, surgical debulking, or both. The aim of this retrospective cohort study was to compare survival and toxicity in patients receiving these treatments and to compare them with a group that received neither form of treatment. Methods: Women diagnosed between January 2009 and January 2017 with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IB2, IIA2-IVA cervical cancer with lymph nodes ≥1.5 cm without upper limit on pretreatment imaging and treated with definitive chemoradiation were selected from the Netherlands Cancer Registry. Patients were categorized by intention-to-treat strategy: boosting, debulking, or neither treatment, with subgroup analysis for patients receiving both treatments, that is, debulking with boosting. Overall and relapse-free survival outcomes were compared by Kaplan-Meier and Cox regression analyses and toxicity by logistic regression analysis. Results: Of 190 patients, 101 (53%) received only nodal boosting, 31 (16%) debulking alone, 29 (15%) debulking combined with boosting, and 29 (15%) received neither treatment. The 5 year overall and relapse-free survival for the treatment groups were 58%, 45% and 45% (p=0.19), and 47%, 44% and 46% (p=0.87), respectively. Multivariable Cox regression analyses demonstrated no differences in overall and relapse-free survival. Combination of debulking with boosting was associated with decreased overall and relapse-free survival compared with debulking alone (HR 2.47, 95% CI 1.22 to 5.00; and HR 2.37, 95% CI 1.14 to 4.93). Nodal boosting was independently associated with a decreased toxicity risk compared with debulking strategy (OR 0.37, 95% CI 0.16 to 0.83). Conclusions: This study showed no survival benefit from either nodal boosting or debulking strategy in patients with suspicious bulky nodes. Nodal boosting might, however, be associated with less toxicity. Dual treatment with debulking and boosting showed a worse survival outcome because this group probably represents patients with poor prognostic factors
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