Background: Ultrahigh dose-rate radiation (UHDR) produces less hydrogen peroxide (HO) in pure water, as suggested by some experimental studies, and is used as an argument for the validity of the theory that FLASH spares the normal tissue due to less reactive oxygen species (ROS) production. In contrast, most Monte Carlo simulation studies suggest the opposite.
Purpose: We aim to unveil the effect of UHDR on HO production in pure water and its underlying mechanism, to serve as a benchmark for Monte Carlo simulation.
To compare two independently developed methods that enable modelling inter-track interactions in TOPAS-nBio by examining the yield of radiolytic species in radiobiological Monte Carlo track structure simulations. One method uses a phase space file to assign more than one primary to one event, allowing for inter-track interaction between these primary particles. This method has previously been developed by this working group and published earlier.
View Article and Find Full Text PDFTo investigate the influence of different versions of the Monte Carlo codesgeant4 andflukaon the calculation of overall response functionsof air-filled ionization chambers in clinical proton beams.factors were calculated for six plane-parallel and four cylindrical ionization chambers withgeant4 andfluka. These factors were compared to already published values that were derived using older versions of these codes.
View Article and Find Full Text PDFSkeletal remains discovered in Simon's Town, South Africa, were hypothesised as being associated with a former Dutch East India Company (VOC) hospital. We report a novel combined osteological and biochemical approach to these poorly-preserved remains. A combined strontium (Sr/Sr), oxygen (δO) and carbon (δC) isotope analysis informed possible childhood origins and diet, while sex-specific amelogenin enamel peptides revealed biological sex.
View Article and Find Full Text PDFIn FLASH radiotherapy (dose rates ≥40 Gy s), a reduced normal tissue toxicity has been observed, while maintaining the same tumor control compared to conventional radiotherapy (dose rates ≤0.03 Gy s). This protecting effect could not be fully explained yet.
View Article and Find Full Text PDFBundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz
June 2023
In the view of the German government, the One Health approach is a pioneering compass for inter- and transdisciplinary thinking, networking, and action. To protect the health of humans, animals, plants, and ecosystems, it should always receive attention at all its interfaces and activities. The One Health approach has gained political importance in recent years and is being taken into account in several strategies.
View Article and Find Full Text PDFMemory T cells form an essential part of immunological memory, which can last for years or even a lifetime. Much experimental work has shown that the individual cells that make up the memory T-cell pool are in fact relatively short-lived. Memory T cells isolated from the blood of humans, or the lymph nodes and spleen of mice, live about 5-10 fold shorter than naive T cells, and much shorter than the immunological memory they convey.
View Article and Find Full Text PDFCytomegalovirus (CMV) infection has a major impact on the T-cell pool, which is thought to be associated with ageing of the immune system. The effect on the T-cell pool has been interpreted as an effect of CMV on non-CMV specific T-cells. However, it remains unclear whether the effect of CMV could simply be explained by the presence of large, immunodominant, CMV-specific memory CD8+ T-cell populations.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2021
Despite heightened awareness of the detrimental impact of hate speech on social media platforms on affected communities and public discourse, there is little consensus on approaches to mitigate it. While content moderation-either by governments or social media companies-can curb online hostility, such policies may suppress valuable as well as illicit speech and might disperse rather than reduce hate speech. As an alternative strategy, an increasing number of international and nongovernmental organizations (I/NGOs) are employing counterspeech to confront and reduce online hate speech.
View Article and Find Full Text PDFIn particle therapy of lung tumors, modulating effects on the particle beam may occur due to the microscopic structure of the lung tissue. These effects are caused by the heterogeneous nature of the lung tissue and cannot be completely taken into account during treatment planning, because these micro structures are too small to be fully resolved in the planning CT. In several publications, a new material parameter called modulation power () was introduced to characterize the effect.
View Article and Find Full Text PDFThe purpose of this work is to investigate the feasibility of TOPAS-nBio for track structure simulations using tuple scoring and ROOT/Python-based post-processing.There are several example applications implemented in GEANT4-DNA demonstrating track structure simulations. These examples are not implemented by default in TOPAS-nBio.
View Article and Find Full Text PDFTo provide Monte Carlo calculated beam quality correction factors () for monoenergetic proton beams using the Monte Carlo codefluka.The Monte Carlo codeflukawas used to calculate the dose absorbed in a water-filled reference volume and the air-filled cavities of six plane-parallel and four cylindrical ionization chambers. The chambers were positioned at the entrance region of monoenergetic proton beams with energies between 60 and 250 MeV.
View Article and Find Full Text PDFProviding health information is a non-pharmaceutical intervention designed to reduce disease transmission and infection risk by encouraging behavior change. But does knowledge change behavior? We test whether coronavirus health knowledge promotes protective risk mitigation behaviors early in the Covid-19 pandemic in samples from four African countries (Ghana, Malawi, Sierra Leone, and Tanzania). Despite reputations for weak health sectors and low average levels of education, health knowledge of the symptoms and transmission mechanisms was high in all countries in the two months after the virus entered the country.
View Article and Find Full Text PDFTo treat lung tumours with particle therapy, different additional tasks and challenges in treatment planning and application have to be addressed thoroughly. One of these tasks is the quantification and consideration of the Bragg peak (BP) degradation due to lung tissue: as lung is an heterogeneous tissue, the BP is broadened when particles traverse the microscopic alveoli. These are not fully resolved in clinical CT images and thus, the effect is not considered in the dose calculation.
View Article and Find Full Text PDFPoly- and cyclophosphazenes are excellent flame retardants but currently, are not used as textile finishing agents because water-soluble and permanent washing systems are missing. Here, we demonstrate for the first time, the successful usage of a water-soluble cyclotriphosphazene derivative for textile finishing for cotton, different cotton/polyester, and cotton/polyamide blend fabrics. A durable finish was achieved using a photoinduced grafting reaction.
View Article and Find Full Text PDFSeveral ionic liquids are excellent solvents for cellulose. Starting from that finishing of PET fabrics with cellulose dissolved in ionic liquids like 1-ethyl-3-methyl imidazolium acetate, diethylphosphate and chloride, or the chloride of butyl-methyl imidazolium has been investigated. Finishing has been carried out from solutions of different concentrations, using microcrystalline cellulose or cotton and by employing different cross-linkers.
View Article and Find Full Text PDFStudy Question: Does the initiation of corifollitropin alfa administration on cycle day 4 instead of cycle day 2 result in a reduced total rFSH consumption in a GnRH antagonist protocol?
Summary Answer: Initiation of corifollitropin alfa on cycle day 4 compared with day 2 results in significantly reduced total rFSH consumption at the end of the follicular phase.
What Is Known Already: In vitro fertilization treatment is associated with significant physical, psychological and emotional stress in infertile patients. This notion has fuelled the search for simplified treatment approaches that may reduce the treatment burden.
The use of a gonadotrophin-releasing hormone (GnRH) agonist to trigger final oocyte maturation in a GnRH antagonist protocol has been associated with poorer clinical outcomes due to an increased luteal-phase defect. It has been shown that LH activity is crucial in a normal luteal phase. Studies assessing the LH concentrations after clomiphene citrate co-treatment have observed increased luteal-phase LH concentrations.
View Article and Find Full Text PDFPurpose: Rifampin combination therapy plays an important role in the management of staphylococcal periprosthetic joint infection (PJI). However, the emergence of rifampin resistance is a feared complication. We retrospectively analysed predetermined potential risk factors in patients with rifampin-resistant staphylococcal PJI in a multicentre case-control study.
View Article and Find Full Text PDFMultiple myeloma is a heterogeneous disease, which is characterized by the occurrence of specific genomic abnormalities that are both of diagnostic and prognostic relevance. Since the detection of these abnormalities through molecular-genetic techniques is hampered by the overall low percentage of plasma cells present in primary bone marrow aspirates, we assessed the efficacy of these techniques in enriched plasma cell fractions from 61 multiple myeloma patients. Using interphase FISH, genomic abnormalities could be detected in 96% of the enriched samples as compared to 61% in the cultured whole bone marrow samples.
View Article and Find Full Text PDFObjectives: Previous studies have revealed that memory performance is diminished in chronic pain patients. Few studies, however, have assessed multiple components of memory in a single sample. It is currently also unknown whether attentional problems, which are commonly observed in chronic pain, mediate the decline in memory.
View Article and Find Full Text PDFThe purpose of this study was to determine if interval training at 110-120% of peak power output one and two days/wk in addition to habitual training would elicit improvements in lactate threshold (LT) in a dose response manner. Twenty physically active individuals completed this study: age--21.1+/-1.
View Article and Find Full Text PDFPatients with a life-threatening illness can be confronted with various types of loneliness, one of which is existential loneliness (EL). Since the experience of EL is extremely disruptive, the issue of EL is relevant for the practice of end-of-life care. Still, the literature on EL has generated little discussion and empirical substantiation and has never been systematically reviewed.
View Article and Find Full Text PDFThe hereditary spastic paraplegias (HSP) are a heterogeneous group of familial movement disorders sharing progressive spastic paraplegia as a common disease sign. In the present study, we performed the first pathoanatomical investigation of the central nervous degeneration of a female patient with a complicated HSP form who suffered from progressive spastic paraplegia, dysarthria, emotional symptoms, cognitive decline and a variety of additional neuropsychological deficits. This pathoanatomical investigation revealed in addition to loss of layer V Betz pyramidal cells in the primary motor cortex, widespread cerebellar neurodegeneration (i.
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