167 research outputs found

    Comparison of xenon triple point realizations

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    It is widely recognized that the Mercury triple point (MTP) being situated very close to the Water triple point (WTP) constitutes a weakness in the International Temperature Scale of 1990 (ITS-90), in addition to safety concerns related to the use and transportation of Mercury. As such, a substitution for a safer, high-quality fixed point about half way between the Argon and Water triple points would be highly desirable. Now, a direct comparison is described of a Xenon cell filled in 2005 by the National Research Council Canada (NRC) and a more recently produced cell of the Istituto Nazionale di Ricerca Metrologica (INRIM). The present paper discusses the INRiM 2017 measurements on both the INRiM and NRC cells, with a follow-up measurement at NRC, and presents the difference between the two cells, (0.17 ± 0.08) mK with the uncertainties of each cell’s realization of the Xenon triple point (XeTP), 0.11 mK for the INRiM cell and 0.07 mK for the NRC cell (k = 1). In addition, the effect of substituting Mercury with Xenon on Type 1 non-uniqueness (‘SRI’, subrange inconsistency), Type 3 non-uniqueness (‘NU3’, cSPRT variability) and propagation of fixed point realization uncertainty is shown and discussed

    A transcriptome analysis identifies molecular effectors of unconjugated bilirubin in human neuroblastoma SH-SY5Y cells

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    Background: The deposition of unconjugated bilirubin (UCB) in selected regions of the brain results in irreversible neuronal damage, or Bilirubin Encephalopathy (BE). Although UCB impairs a large number of cellular functions in other tissues, the basic mechanisms of neurotoxicity have not yet been fully clarified. While cells can accumulate UCB by passive diffusion, cell protection may involve multiple mechanisms including the extrusion of the pigment as well as pro-survival homeostatic responses that are still unknown. Results: Transcriptome changes induced by UCB exposure in SH-SY5Y neuroblastoma cell line were examined by high density oligonucleotide microarrays. Two-hundred and thirty genes were induced after 24 hours. A Gene Ontology (GO) analysis showed that at least 50 genes were directly involved in the endoplasmic reticulum (ER) stress response. Validation of selected ER stress genes is shown by quantitative RT-PCR. Analysis of XBP1 splicing and DDIT3/CHOP subcellular localization is presented. Conclusion: These results show for the first time that UCB exposure induces ER stress response as major intracellular homeostasis in surviving neuroblastoma cells in vitro

    Analysis of Serum Th2 Cytokines in Infants with Non-IgE Mediated Food Allergy Compared to Healthy Infants

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    Background: The aim of this study is to assess the serum values of IL-4, IL-5, IL-10, and IL-13 in a group of infants with non-IgE mediated food allergies treated with a hydrolyzed formula and compare them with a group of healthy peers. Methods: A total of 53 infants aged 1 to 4 months, of which 34 with non-IgE mediated food allergies and 19 healthy infants were enrolled in this study. Infants were eligible if they had gastrointestinal symptoms of food allergy and needed to switch from their initial formula to hydrolyzed formulas with an improvement of symptoms. Controls were fed with either breastmilk or standard formula. Blood samples were taken within one week of a special diet for cases. Interleukinsin in peripheral blood was detected and analyzed using the real-time PCR MAMA method. Fecal calprotectin was evaluated using a quantitative assay. Results: Values of IL-4 and IL-13 were significantly higher in the non-IgE food allergy group compared to the control group (p < 0.05), while IL-5 and IL-10 were significantly lower than the control group (p < 0.05). Fecal calprotectin in the non-IgE food allergy group was significantly higher compared to the control group (p < 0.05). Conclusion: This study provides a theoretical basis that Th2 cytokine expression in infants with a non-IgE mediated food allergy is significantly different than in healthy infants; this finding supports the use of early dietetic treatment with hydrolyzed formulas

    Quaternary glacial history of the Mediterranean mountains

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    Glacial and periglacial landforms are widespread in the mountains of the Mediterranean region. The evidence for glacial and periglacial activity has been studied for over 120 years and it is possible to identify three phases of development in this area of research. First, a pioneer phase characterized by initial descriptive observations of glacial landforms; second, a mapping phase whereby the detailed distribution of glacial landforms and sediments have been depicted on geomorphological maps; and, third, an advanced phase characterized by detailed understanding of the geochronology of glacial sequences using radiometric dating alongside detailed sedimentological and stratigraphical analyses. It is only relatively recently that studies of glaciated mountain terrains in the Mediterranean region have reached an advanced phase and it is now clear from radiometric dating programmes that the Mediterranean mountains have been glaciated during multiple glacial cycles. The most extensive phases of glaciation appear to have occurred during the Middle Pleistocene. This represents a major shift from earlier work whereby many glacial sequences were assumed to have formed during the last cold stage. Glacial and periglacial deposits from multiple Quaternary cold stages constitute a valuable palaeoclimatic record. This is especially so in the Mediterranean mountains, since mountain glaciers in this latitudinal zone would have been particularly sensitive to changes in the global climate system. © 2006 Edward Arnold (Publishers) Ltd

    Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change

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    Background: Approximately two hundred human burials were discovered on the edge of a paleolake in Niger that providea uniquely preserved record of human occupation in the Sahara during the Holocene (,8000 B.C.E. to the present). CalledGobero, this suite of closely spaced sites chronicles the rapid pace of biosocial change in the southern Sahara in response tosevere climatic fluctuation.Methodology/Principal Findings: Two main occupational phases are identified that correspond with humid intervals in theearly and mid-Holocene, based on 78 direct AMS radiocarbon dates on human remains, fauna and artifacts, as well as 9 OSLdates on paleodune sand. The older occupants have craniofacial dimensions that demonstrate similarities with mid-Holocene occupants of the southern Sahara and Late Pleistocene to early Holocene inhabitants of the Maghreb. Theirhyperflexed burials compose the earliest cemetery in the Sahara dating to ,7500 B.C.E. These early occupants abandon thearea under arid conditions and, when humid conditions return ,4600 B.C.E., are replaced by a more gracile people withelaborated grave goods including animal bone and ivory ornaments.Conclusions/Significance: The principal significance of Gobero lies in its extraordinary human, faunal, and archaeologicalrecord, from which we conclude the following:(1) The early Holocene occupants at Gobero (7700–6200 B.C.E.) were largely sedentary hunter-fisher-gatherers withlakeside funerary sites that include the earliest recorded cemetery in the Sahara.(2) Principal components analysis of craniometric variables closely allies the early Holocene occupants at Gobero with askeletally robust, trans-Saharan assemblage of Late Pleistocene to mid-Holocene human populations from the Maghreband southern Sahara.(3) Gobero was abandoned during a period of severe aridification possibly as long as one millennium (6200–5200 B.C.E).(4) More gracile humans arrived in the mid-Holocene (5200–2500 B.C.E.) employing a diversified subsistence economybased on clams, fish, and savanna vertebrates as well as some cattle husbandry.(5) Population replacement after a harsh arid hiatus is the most likely explanation for the occupational sequence at Gobero.(6) We are just beginnin

    Body mass index and circulating oestrone sulphate in women treated with adjuvant letrozole

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    Background: Obesity is an independent adverse prognostic factor in early breast cancer patients, but it is still controversial whether obesity may affect adjuvant endocrine therapy efficacy. The aim of our study (ancillary to the two clinical trials Gruppo Italiano Mammella (GIM)4 and GIM5) was to investigate whether the circulating oestrogen levels during treatment with the aromatase inhibitor letrozole are related to body mass index (BMI) in postmenopausal women with breast cancer. Methods: Plasma concentration of oestrone sulphate (ES) was evaluated by radioimmunoassay in 370 patients. Plasma samples were obtained after at least 6 weeks of letrozole therapy (steady-state time). Patients were divided into four groups according to BMI. Differences among the geometric means (by ANOVA and ANCOVA) and correlation (by Spearman's rho) between the ES levels and BMI were assessed. Results: Picomolar geometric mean values (95% confidence interval, n=patients) of circulating ES during letrozole were 58.6 (51.0-67.2, n=150) when BMI was <25.0 kg m-2; 65.6 (57.8-74.6, n=154) when 25.0-29.9 kg m-2; 59.3 (47.1-74.6, n=50) when 30.0-34.9 kg m -2; and 43.3 (23.0-81.7, n=16) when 6535.0 kg m-2. No statistically significant difference in terms of ES levels among groups and no correlation with BMI were observed. Conclusions: Body mass index does not seem to affect circulating oestrogen levels in letrozole-treated patient

    Functional Induction of the Cystine-Glutamate Exchanger System Xc- Activity in SH-SY5Y Cells by Unconjugated Bilirubin

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    We have previously reported that exposure of SH-SY5Y neuroblastoma cells to unconjugated bilirubin (UCB) resulted in a marked up-regulation of the mRNA encoding for the Na+ -independent cystine∶glutamate exchanger System Xc− (SLC7A11 and SLC3A2 genes). In this study we demonstrate that SH-SY5Y cells treated with UCB showed a higher cystine uptake due to a significant and specific increase in the activity of System Xc−, without the contribution of the others two cystine transporters (XAG− and GGT) reported in neurons. The total intracellular glutathione content was 2 folds higher in the cells exposed to bilirubin as compared to controls, suggesting that the internalized cystine is used for gluthathione synthesis. Interestingly, these cells were significantly less sensitive to an oxidative insult induced by hydrogen peroxide. If System Xc− is silenced the protection is lost. In conclusion, these results suggest that bilirubin can modulate the gluthathione levels in neuroblastoma cells through the induction of the System Xc−, and this renders the cell less prone to oxidative damage
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