118 research outputs found

    High Performance X-Ray Transmission Windows Based on Graphenic Carbon

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    A novel x-ray transmission window based on graphenic carbon has been developed with superior performance compared to beryllium transmission windows that are currently used in the field. Graphenic carbon in combination with an integrated silicon frame allows for a window design which does not use a mechanical support grid or additional light blocking layers. Compared to beryllium, the novel x-ray transmission window exhibits an improved transmission in the low energy region (0.1hboxkeV−3hboxkeV0.1 hbox{keV}-3 hbox{keV} ) while demonstrating excellent mechanical stability, as well as light and vacuum tightness. Therefore, the newly established graphenic carbon window, can replace beryllium in x-ray transmission windows with a nontoxic and abundant material. Index terms: Beryllium, Carbon, Graphene, Thin films, X-ray applications, X-ray detector

    Common Fragile Site Tumor Suppressor Genes and Corresponding Mouse Models of Cancer

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    Chromosomal common fragile sites (CFSs) are specific mammalian genomic regions that show an increased frequency of gaps and breaks when cells are exposed to replication stress in vitro. CFSs are also consistently involved in chromosomal abnormalities in vivo related to cancer. Interestingly, several CFSs contain one or more tumor suppressor genes whose structure and function are often affected by chromosomal fragility. The two most active fragile sites in the human genome are FRA3B and FRA16D where the tumor suppressor genes FHIT and WWOX are located, respectively. The best approach to study tumorigenic effects of altered tumor suppressors located at CFSs in vivo is to generate mouse models in which these genes are inactivated. This paper summarizes our present knowledge on mouse models of cancer generated by knocking out tumor suppressors of CFS

    Antimicrobial Use in Pediatric Oncology and Hematology: Protocol for a Multicenter Point-Prevalence Study With Qualitative Expert Panel Assessment

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    Background: Because infections are a major driver of morbidity and mortality in children with hematologic or oncologic diseases, antimicrobials are frequently prescribed in pediatric oncology practice. However, excess or inappropriate use of antimicrobials is directly linked to the emergence of antimicrobial resistance. Although point-prevalence studies have examined the extent of antimicrobial use, a comprehensive qualitative evaluation of individual antimicrobial prescriptions remains lacking. Objective: The aim of this study is to identify appropriate versus inappropriate antimicrobial use among pediatric cancer patients in a point-prevalence study, followed by an expert panel adjudication process and a subsequent report of these findings to participating centers. This study also aims to improve the quality of patient care by informing centers about discrepancies between internal standards of care and national guidelines. Methods: Our point-prevalence study is performed at pediatric cancer centers in Germany and Austria. All patients under 18 years old who are hospitalized at the time of the study are included. As a supplement to the point-prevalence study, an expert panel is qualitatively assessing each of the antimicrobial prescriptions at the participating centers to review local guidelines and compare them with national guidelines. Results: As of December 2021, the point-prevalence survey has been conducted at 30 sites and expert panel adjudication for qualitative assessment of each antimicrobial use is ongoing. Results of the study are expected in 2022. Conclusions: This is the first point-prevalence study conducted among pediatric cancer centers with an integrated, multistep, qualitative approach that assesses each antimicrobial prescription. The results of this study will inform possible interventions for internal guidelines and antimicrobial stewardship programs implemented at pediatric cancer centers. In addition, local guidelines will be compared with national guidelines. Furthermore, this study will contribute to the overall integration of antimicrobial stewardship principles and initiatives in pediatric oncology and hematology, thereby improving safety and quality of care for children and adolescents with cancer and blood disorders

    A water cycle for the Anthropocene

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    International audienceHumor us for a minute and do an online image search of the water cycle. How many diagrams do you have to scroll through before seeing any sign of humans? What about water pollution or climate change—two of the main drivers of the global water crisis? In a recent analysis of more than 450 water cycle diagrams, we found that 85% showed no human interaction with the water cycle and 98% omitted any sign of climate change or waterpollution (Abbott et al., 2019). Additionally, 92% of diagrams depicted verdant, temperate ecosystems with abundant freshwater and 95% showed only a single river basin. It did not matter if the diagrams came from textbooks, scientific articles, or the internet, nor if they were old or new; most showed an undisturbed water cycle, free from human interference. These depictions contrast starkly with the state of the water cycle in the Anthropocene, when land conversion, human water use, and climate change affect nearly every water pool and flux (Wurtsbaugh et al., 2017; Falkenmark et al., 2019; Wine and Davison, 2019). The dimensions and scale of human interference with water are manifest in failing fossil aquifersin the world’s great agricultural regions (Famiglietti, 2014), accelerating ice discharge from the Arctic (Box et al., 2018), and instability in atmospheric rivers that support continental rainfall (Paul et al., 2016).We believe that incorrect water cycle diagrams are a symptom of a much deeper and widespread problem about how humanity relates to water on Earth. Society does not understand how the water cycle works nor how humans fit into it (Attari, 2014; Linton, 2014; Abbott et al., 2019). In response to this crisis of understanding, we call on researchers, educators, journalists, lawyers, and policy makers to change how we conceptualize and present the global water cycle. Specifically, we must teach where water comes from, what determines its availability, and how many individuals and ecosystems are in crisis because of water mismanagement, climate change, and land conversion. Because the drivers of the global water crisis are truly global, ensuring adequate water for humans and ecosystems will require coordinated efforts that extend beyond geopolitical borders and outlast the tenure of individual administrations (Keys et al., 2017; Adler, 2019). This level of coordination and holistic thinking requires widespread understanding of the water cycle and the global water crisis. Making the causes and consequences of the water crisis visible in our diagrams is atractable and important step towards the goal of a sustainable relationship with water that includes ecosystems and society

    Human domination of the global water cycle absent from depictions and perceptions

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    International audienceHuman water use, climate change and land conversion have created a water crisis for billions of individuals and many ecosystems worldwide. Global water stocks and fluxes are estimated empirically and with computer models, but this information is conveyed to policymakers and researchers through water cycle diagrams. Here we compiled a synthesis of the global water cycle, which we compared with 464 water cycle diagrams from around the world. Although human freshwater appropriation now equals half of global river discharge, only 15% of the water cycle diagrams depicted human interaction with water. Only 2% of the diagrams showed climate change or water pollution—two of the central causes of the global water crisis—which effectively conveys a false sense of water security. A single catchment was depicted in 95% of the diagrams, which precludes the representation of teleconnections such as ocean–land interactions and continental moisture recycling. These inaccuracies correspond with specific dimensions of water mismanagement, which suggest that flaws in water diagrams reflect and reinforce the misunderstanding of global hydrology by policymakers, researchers and the public. Correct depictions of the water cycle will not solve the global water crisis, but reconceiving this symbol is an important step towards equitable water governance, sustainable development and planetary thinking in the Anthropocene

    Single-laser 32.5 Tbit/s Nyquist WDM transmission

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    We demonstrate 32.5 Tbit/s 16QAM Nyquist WDM transmission over a total length of 227 km of SMF-28 without optical dispersion compensation. A number of 325 optical carriers are derived from a single laser and encoded with dual-polarization 16QAM data using sinc-shaped Nyquist pulses. As we use no guard bands, the carriers have a spacing of 12.5 GHz equal to the Nyquist bandwidth of the data. We achieve a high net spectral efficiency of 6.4 bit/s/Hz using a software-defined transmitter which generates the electrical modulator drive signals in real-time.Comment: (c) 2012 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibite

    Longer and better lives for patients with atrial fibrillation:the 9th AFNET/EHRA consensus conference

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    Aims: Recent trial data demonstrate beneficial effects of active rhythm management in patients with atrial fibrillation (AF) and support the concept that a low arrhythmia burden is associated with a low risk of AF-related complications. The aim of this document is to summarize the key outcomes of the 9th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). Methods and results: Eighty-three international experts met in MĂŒnster for 2 days in September 2023. Key findings are as follows: (i) Active rhythm management should be part of the default initial treatment for all suitable patients with AF. (ii) Patients with device-detected AF have a low burden of AF and a low risk of stroke. Anticoagulation prevents some strokes and also increases major but non-lethal bleeding. (iii) More research is needed to improve stroke risk prediction in patients with AF, especially in those with a low AF burden. Biomolecules, genetics, and imaging can support this. (iv) The presence of AF should trigger systematic workup and comprehensive treatment of concomitant cardiovascular conditions. (v) Machine learning algorithms have been used to improve detection or likely development of AF. Cooperation between clinicians and data scientists is needed to leverage the potential of data science applications for patients with AF. Conclusions: Patients with AF and a low arrhythmia burden have a lower risk of stroke and other cardiovascular events than those with a high arrhythmia burden. Combining active rhythm control, anticoagulation, rate control, and therapy of concomitant cardiovascular conditions can improve the lives of patients with AF
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