229 research outputs found

    Switched Capacitor Voltage Converter

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    This project supports IoT development by reducing the power con- sumption and physical footprint of voltage converters. Our switched- capacitor IC design steps down an input of 1:0 - 1:4 V to 0:6 V for a decade of load current from 5 - 50A

    Cryptococcus neoformans Requires a Functional Glycolytic Pathway for Disease but Not Persistence in the Host

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    Cryptococcus neoformans is an important fungal pathogen of immunocompromised individuals, with a close relative, Cryptococcus gattii, emerging as a serious threat for the immunocompetent. During initial infection, C. neoformans colonizes the airspaces of the lungs, resulting in pneumonia, and subsequently migrates to the central nervous system (CNS). We sought to understand fungal carbon utilization during colonization of these fundamentally different niches within the host, in particular the roles of gluconeogenesis and glycolysis. We created mutants at key points in the gluconeogenesis/glycolysis metabolic pathways that are restricted for growth on lactate and glucose, respectively. A phosphoenolpyruvate carboxykinase mutant (the pck1∆ mutant), blocked for entry of 2- and 3-carbon substrates into gluconeogenesis and attenuated for virulence in a murine inhalation model, showed wild-type (WT) persistence in a rabbit cerebrospinal fluid (CSF) model of cryptococcosis. Conversely, both the pyruvate kinase (pyk1∆) and the hexose kinase I and II (hxk1∆/hxk2∆) mutants, which show impaired glucose utilization, exhibited severely attenuated virulence in the murine inhalation model of cryptococcosis and decreased persistence in the CNS in both the rabbit CSF and the murine inhalation models while displaying adequate persistence in the lungs of mice. These data suggest that glucose utilization is critical for virulence of C. neoformans and persistence of the yeast in the CNS

    Scientific Opinion on the hazard assessment of endocrine disruptors: Scientific criteria for identification of endocrine disruptors and appropriateness of existing test methods for assessing effects mediated by these substances on human health and the environment

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    Upon request of the European Commission, the Scientific Committee (SC) of the European Food Safety Authority reviewed existing information related to the testing and assessment of endocrine active substances (EASs) and endocrine disruptors (EDs). This work was conducted by a working group of experts in endocrinology, risk assessment and toxicology, together with observers from other EU agencies, namely EMA, ECHA and EEA. To distinguish between EDs and other groups of substances with different modes of action, it was concluded that an ED is defined by three criteria: the presence of i) an adverse effect in an intact organism or a (sub)population; ii) an endocrine activity; and iii) a plausible causal relationship between the two. As scientific criteria for adversity have not been generally defined, specific criteria for endocrine disrupting effects could not be identified. Hence, expert judgement is required to assess on a case-by-case basis the (eco)toxicological relevance of changes at the molecular to individual and/or (sub)population level following exposure to an EAS. The SC concluded that a reasonably complete suite of standardised assays for testing the effects of EASs is (or will soon be) available for the oestrogenic, androgenic, thyroid and steroidogenic modalities in mammals and fish, with fewer tests for birds and amphibians. Shortcomings in current tests and for other endocrine modalities and species were reviewed. Critical effect, severity, (ir)reversibility and potency aspects are part of the hazard characterisation of EDs. To inform on risk and level of concern for the purpose of risk management decisions, risk assessment (taking into account hazard and exposure data/predictions) makes best use of available information. Levels of concern are not determined exclusively by risk assessment but also by protection goals set by the risk management
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