231 research outputs found

    The FCC-ee Interaction Region Magnet Design

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    The design of the region close to the interaction point of the FCC-ee experiments is especially challenging. The beams collide at an angle (+-15 mrad) in the high-field region of the detector solenoid. Moreover, the very low vertical beta_y* of the machine necessitates that the final focusing quadrupoles have a distance from the IP (L*) of around 2 m and therefore are inside the main detector solenoid. The beams should be screened from the effect of the detector magnetic field, and the emittance blow-up due to vertical dispersion in the interaction region should be minimized, while leaving enough space for detector components. Crosstalk between the two final focus quadrupoles, only about 6 cm apart at the tip, should also be minimized.Comment: Poster presented at IPAC16, May 8-13, Busan, Kore

    Characterizations of how species mediate ecosystem properties require more comprehensive functional effect descriptors

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    The importance of individual species in mediating ecosystem process and functioning is generally accepted, but categorical descriptors that summarize species-specific contributions to ecosystems tend to reference a limited number of biological traits and underestimate the importance of how organisms interact with their environment. Here, we show how three functionally contrasting sediment-dwelling marine invertebrates affect fluid and particle transport - important processes in mediating nutrient cycling - and use high-resolution reconstructions of burrow geometry to determine the extent and nature of biogenic modification. We find that individual functional effect descriptors fall short of being able to adequately characterize how species mediate the stocks and flows of important ecosystem properties and that, in contrary to common practice and understanding, they are not substitutable with one another because they emphasize different aspects of species activity and behavior. When information derived from these metrics is combined with knowledge of how species behave and modify their environment, however, detailed mechanistic information emerges that increases the likelihood that a species functional standing will be appropriately summarized. Our study provides evidence that more comprehensive functional effect descriptors are required if they are to be of value to those tasked with projecting how altered biodiversity will influence future ecosystems

    Alarming increase in poisonings from recreational nitrous oxide use after a change in EU-legislation, inquiries to the Dutch Poisons Information Center

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    BACKGROUND: After the change in EU-legislation in 2014, recreational use of nitrous oxide (N2O) increased in the Netherlands from 2015 onwards. We studied the effect on N2O poisonings during an 11 year period. METHODS: A retrospective observational study was performed on the incidence rate of N2O poisonings, relative to all recreational drug poisonings reported to the Dutch Poisons Information Center (DPIC) from 2010-2020. Secondary outcomes were the frequency of heavy use, frequent use, co-exposures, and toxicity in 2019 and 2020. RESULTS: 433 N2O poisonings were included. The incidence rate increased exponentially from 0.12% in 2010 to 11% in 2020, with an average monthly rate of 3.8%. In 2019 and 2020, 79% of the patients indicated heavy use, frequent use or both, and 42% used from large cylinders. Chronic toxicity (signs of peripheral neuropathy) was reported in 38% of the patients. CONCLUSION: The rate of N2O poisonings increased alarmingly in the Netherlands. An increasing proportion of patients reported problematic heavy or frequent use, accompanied by chronic toxicity

    High Incidence of Signs of Neuropathy and Self-Reported Substance Use Disorder for Nitrous Oxide in Patients Intoxicated with Nitrous Oxide

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    Introduction: The number of patients with excessive nitrous oxide (N2O) use and neurological disorders has been rising, indicating an addictive potential of N2O. We studied the incidence of self-reported substance use disorder (SUD)-related symptoms, signs of neuropathy, and the patterns of use in N2O-intoxicated patients. Methods: The Dutch Poisons Information Center (DPIC) provides information by telephone on the management of intoxications to healthcare professionals. Retrospective data on signs of neuropathy and patterns of use were collected for all N2O intoxications reported to the DPIC in 2021 and 2022. Frequent and heavy use were self-reported as "often/frequent/weekly use"and as "use of tanks or >50 balloons/session,"respectively. From this cohort, we included patients with excessive N2O use or signs of neuropathy in a prospective observational cohort study. Online surveys were sent 1 week, 1 month, and 3 months after DPIC consultation. The survey included the drug use disorder questionnaire (validated to measure self-reported substance abuse [SA] and substance dependence [SD] based on Diagnostic and Statistical Manual of Mental Disorders [DSM]-IV-TR criteria) and questions on patterns of use and signs of neuropathy. DSM-IV-TR criteria were translated to DSM-V criteria to score for mild, moderate, or severe SUD, with 2-3, 4-5, or ≥6 symptoms, respectively. Results: We included 101 N2O-intoxicated patients in the retrospective study. Of these, 41% showed signs of neuropathy (N = 41), 53% used N2O tanks to fill balloons (N = 53), 71% used them frequently (N = 72), and 76% used them heavily (N = 77). We included 75 patients in the prospective study and 10 (13%) completed the first survey. All 10 patients fulfilled the criteria for SA and SD (DSM-IV-TR, median number of questions answered "yes"= 10/12), all used N2O tanks to fill balloons, and 90% (N = 9) experienced signs of neuropathy. After 1 and 3 months, 6/7 and 1/1 patients, respectively, continued to fulfill SA and SD criteria. Translating to DSM-V criteria, 1/10 patients fulfilled the criteria for (self-reported) mild SUD, 1/10 patients for moderate SUD, and 8/10 patients for severe SUD, 1 week after consultation. Conclusion: The high proportion of N2O-intoxicated patients reporting frequent and heavy use of N2O indicates an addictive potential of N2O. Although follow-up rate was low, all patients fulfilled self-reported SA, SD (DSM-IV-TR), and SUD (DSM-V) criteria for N2O. Somatic healthcare professionals treating patients with N2O intoxications should be aware of possible addictive behavior in patients. The screening, brief intervention, and referral to treatment approach should be considered to treat patients with self-reported SUD symptoms

    Expression of the immune modulator secretory leukocyte protease inhibitor (SLPI) in colorectal cancer liver metastases and matched primary tumors is associated with a poorer prognosis

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    Secretory leukocyte protease inhibitor (SLPI), a pleiotropic protein expressed by healthy intestinal epithelial cells, functions as an inhibitor of NF-κB and neutrophil proteases and exerts antimicrobial activity. We previously showed SLPI suppresses intestinal epithelial chemokine production in response to microbial contact. Increased SLPI expression was recently detected in various types of carcinoma. In addition, accumulating evidence indicates SLPI expression is favorable for tumor cells. In view of these findings and the abundance of SLPI in the colonic epithelium, we hypothesized SLPI promotes colorectal cancer (CRC) growth and metastasis. Here, we aimed to establish wh

    Duplication of the IL2RA locus causes excessive IL-2 signaling and may predispose to very early onset colitis

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    Single genetic mutations predispose to very early onset inflammatory bowel disease (VEO-IBD). Here, we identify a de novo duplication of the 10p15.1 chromosomal region, including the IL2RA locus, in a 2-year-old girl with treatment-resistant pancolitis that was brought into remission by colectomy. Strikingly, after colectomy while the patient was in clinical remission and without medication, the peripheral blood CD4:CD8 ratio was constitutively high and CD25 expression was increased on circulating effector memory, Foxp3(+), and Foxp3(neg) CD4(+) T cells compared to healthy controls. This high CD25 expression increased IL-2 signaling, potentiating CD4(+) T-cell-derived IFN gamma secretion after T-cell receptor (TCR) stimulation. Restoring CD25 expression using the JAK1/3-inhibitor tofacitinib controlled TCR-induced IFN gamma secretion in vitro. As diseased colonic tissue, but not the unaffected duodenum, contained mainly CD4(+) T cells with a prominent IFN gamma-signature, we hypothesize that local microbial stimulation may have initiated colonic disease. Overall, we identify that duplication of the IL2RA locus can associate with VEO-IBD and suggest that increased IL-2 signaling predisposes to colonic intestinal inflammation.Transplantation and immunomodulatio

    The enigma of in vivo oxidative stress assessment: isoprostanes as an emerging target

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    Oxidative stress is believed to be one of the major factors behind several acute and chronic diseases, and may also be associated with ageing. Excess formation of free radicals in miscellaneous body environment may originate from endogenous response to cell injury, but also from exposure to a number of exogenous toxins. When the antioxidant defence system is overwhelmed, this leads to cell damage. However, the measurement of free radicals or their endproducts is tricky, since these compounds are reactive and short lived, and have diverse characteristics. Specific evidence for the involvement of free radicals in pathological situations has been difficult to obtain, partly owing to shortcomings in earlier described methods for the measurement of oxidative stress. Isoprostanes, which are prostaglandin-like bioactive compounds synthesized in vivo from oxidation of arachidonic acid, independently of cyclooxygenases, are involved in many human diseases, and their measurement therefore offers a way to assess oxidative stress. Elevated levels of F2-isoprostanes have also been seen in the normal human pregnancy, but their physiological role has not yet been defined. Large amounts of bioactive F2-isoprostanes are excreted in the urine in normal basal situations, with a wide interindividual variation. Their exact role in the regulation of normal physiological functions, however, needs to be explored further. Current understanding suggests that measurement of F2-isoprostanes in body fluids provides a reliable analytical tool to study oxidative stress-related diseases and experimental inflammatory conditions, and also in the evaluation of various dietary antioxidants, as well as drugs with radical-scavenging properties. However, assessment of isoprostanes in plasma or urine does not necessarily reflect any specific tissue damage, nor does it provide information on the oxidation of lipids other than arachidonic acid

    Substrate cycling between de novo lipogenesis and lipid oxidation: a thermogenic mechanism against skeletal muscle lipotoxicity and glucolipotoxicity

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    Life is a combustion, but how the major fuel substrates that sustain human life compete and interact with each other for combustion has been at the epicenter of research into the pathogenesis of insulin resistance ever since Randle proposed a 'glucose-fatty acid cycle' in 1963. Since then, several features of a mutual interaction that is characterized by both reciprocality and dependency between glucose and lipid metabolism have been unravelled, namely: 1. the inhibitory effects of elevated concentrations of fatty acids on glucose oxidation (via inactivation of mitochondrial pyruvate dehydrogenase or via desensitization of insulin-mediated glucose transport), 2. the inhibitory effects of elevated concentrations of glucose on fatty acid oxidation (via malonyl-CoA regulation of fatty acid entry into the mitochondria), and more recently 3. the stimulatory effects of elevated concentrations of glucose on de novo lipogenesis, that is, synthesis of lipids from glucose (via SREBP1c regulation of glycolytic and lipogenic enzymes). This paper first revisits the physiological significance of these mutual interactions between glucose and lipids in skeletal muscle pertaining to both blood glucose and intramyocellular lipid homeostasis. It then concentrates upon emerging evidence, from calorimetric studies investigating the direct effect of leptin on thermogenesis in intact skeletal muscle, of yet another feature of the mutual interaction between glucose and lipid oxidation: that of substrate cycling between de novo lipogenesis and lipid oxidation. It is proposed that this energy-dissipating substrate cycling that links glucose and lipid metabolism to thermogenesis could function as a 'fine-tuning' mechanism that regulates intramyocellular lipid homeostasis, and hence contributes to the protection of skeletal muscle against lipotoxicity
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