201 research outputs found

    Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of nicotine and its metabolites in placenta and umbilical cord.

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    Tobacco exposure during pregnancy is associated with obstetric and fetal complications. This study developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyse the placenta (PL) and umbilical cord (UC) for nicotine, cotinine and hydroxycotinine (OH-cotinine). Specimens were homogenized in water, followed by solid-phase extraction. Chromatographic separation was performed using an Atlantis HILIC Silica column. Detection was accomplished in electrospray in positive mode. Method validation included: linearity (5 to 1000 ng/g), accuracy (86.9 to 105.2% of target concentration in PL, and 89.1 to 105.0% in UC), imprecision (6.8 to 11.8% in PL, and 7.6 to 12.2% in UC), limits of detection (2 ng/g for cotinine and OH-cotinine, and 5 ng/g for nicotine) and quantification (5 ng/g), selectivity (no endogenous or exogenous interferences), matrix effect (-34.1 to -84.5% in PL, %CV = 9.1-24.0%; -18.9 to -84.7% in UC, %CV = 10.2-23.9%), extraction efficiency (60.7 to 131.5% in PL, and 64.1 to 134.2% in UC), and stability 72 h in the autosampler ( < 11.5% loss in PL, and < 13% loss in UC). The method was applied to 14 PL and UC specimens from tobacco users during pregnancy. Cotinine (6.8-312.2 ng/g in PL; 6.7-342.3 ng/g in UC) was the predominant analyte, followed by OH-cotinine ( < LOQ-80.2 ng/g in PL; < LOQ-80.5 ng/g in UC) and nicotine (5.7-63.7 ng/g in PL; 5.1-63.3 ng/g in UC). In a future study, this method will be applied to more than 150 specimens collected from a wide clinical study to evaluate the usefulness of maternal hair, meconium, placenta and umbilical cord compared to the maternal interview to detect in utero drug exposure

    Evaluation of preindustrial to present-day black carbon and its albedo forcing from ACCMIP (Atmospheric Chemistry and Climate Model Intercomparison Project)

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    As part of the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), we evaluate the historical black carbon (BC) aerosols simulated by 8 ACCMIP models against observations including 12 ice core records, long-term surface mass concentrations and recent Arctic BC snowpack measurements. We also estimate BC albedo forcing by performing additional simulations using offline models with prescribed meteorology from 1996–2000. We evaluated the vertical profile of BC snow concentrations from these offline simulations using the recent BC snowpack measurements. Despite using the same BC emissions, the global BC burden differs by approximately a factor of 3 among models due to differences in aerosol removal parameterizations and simulated meteorology: 34 Gg to 103 Gg in 1850 and 82 Gg to 315 Gg in 2000. However, the global BC burden from preindustrial to present-day increases by 2.5–3 times with little variation among models, roughly matching the 2.5-fold increase in total BC emissions during the same period. We find a large divergence among models at both Northern Hemisphere (NH) and Southern Hemisphere (SH) high latitude regions for BC burden and at SH high latitude regions for deposition fluxes. The ACCMIP simulations match the observed BC surface mass concentrations well in Europe and North America except at Jungfraujoch and Ispra. However, the models fail to predict the Arctic BC seasonality due to severe underestimations during winter and spring. The simulated vertically resolved BC snow concentrations are, on average, within a factor of 2–3 of the BC snowpack measurements except for Greenland and the Arctic Ocean. For the ice core evaluation, models tend to capture both the observed temporal trends and the magnitudes well at Greenland sites. However, models fail to predict the decreasing trend of BC depositions/ice-core concentrations from the 1950s to the 1970s in most Tibetan Plateau ice cores. The distinct temporal trend at the Tibetan Plateau ice cores indicates a strong influence from Western Europe, but the modeled BC increases in that period are consistent with the emission changes in Eastern Europe, the Middle East, South and East Asia. At the Alps site, the simulated BC suggests a strong influence from Europe, which agrees with the Alps ice core observations. Models successfully simulate higher BC concentrations observed at Zuoqiupu during the non-monsoon season than monsoon season, but models underpredict BC in both seasons. Despite a large divergence in BC deposition at two Antarctic ice core sites, models are able to capture the relative increase from preindustrial to present-day seen in the ice cores. In 2000 relative to 1850, globally annually averaged BC surface albedo forcing from the offline simulations ranges from 0.014 to 0.019 W m−2 among the ACCMIP models. Comparing offline and online BC albedo forcings computed by some of the same models, we find that the global annual mean can vary by up to a factor of two because of different aerosol models or different BC-snow parameterizations and snow cover. The spatial distributions of the offline BC albedo forcing in 2000 show especially high BC forcing (i.e. over 0.1 W m−2) over Manchuria, Karakoram, and most of the Former USSR. Models predict the highest global annual mean BC forcing in 1980 rather than 2000, mostly driven by the high fossil fuel and biofuel emissions in the Former USSR in 1980

    The Contribution of CALL to Advanced-Level Foreign/Second Language Instruction

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    This paper evaluates the contribution of instructional technology to advanced-level foreign/second language learning (AL2) over the past thirty years. It is shown that the most salient feature of AL2 practice and associated Computer-Assisted Language Learning (CALL) research are their rarity and restricted nature. Based on an analysis of four leading CALL journals (CALICO, CALL, LL&T, ReCALL), less than 3% of all CALL publications deal with AL2. Moreover, within this body of research, the range of languages involved is very restricted. Three languages, English, German and French, account for nearly 87% of the studies. Likewise, in nearly 81% of the cases, the learning focus is on the written language. Attention to oral-aural skills accounts for only 18% of all AL2 CALL projects. Whatever the targeted language or linguistic focus, the most striking aspect of advanced-level L2 CALL studies is the lack of information given regarding the competency level of students and the linguistic level of the activities undertaken. The determination of these critical parameters is thus of necessity very much a highly interpretive process. Based on the available evidence, it is estimated that half of the learners in these AL2 studies were in fact within the Common European Framework of Reference (CEFR) B1 range, i.e. below what would generally be considered as advanced-level competency. So, too, half of the assigned tasks were deemed to have been below the B2 level, with 40% of these below the B1 level. This study concludes that both quantitatively and qualitatively the contribution of instructional technology to advanced-level L2 acquisition has been very limited

    Menopausia y Terapia Hormonal de la Menopausia Las recomendaciones 2018 de la Unidad de Endocrinología Ginecológica de Clínica Alemana de Santiago -Sociedad Italiana de la Menopausia y la Sociedad Chilena de Endocrinología Ginecológica

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    ABSTRACT In the last decade, the risk benefits ratio of MHT has been evaluated mainly in terms of cardiovascular risk. Present Consensus Statement is largely inspired by the Global Consensus on Menopausal Hormone Therapy in 2013 and 2016 by leading global menopause societies (The American Society for Reproductive Medicine, The Asia Pacific Menopause Federation, The Endocrine Society, The European Menopause and Andropause Society, The International Menopause Society, The International Osteoporosis Foundation and The North American Menopause Society). The aim of these Recommendations is to provide a simple and updated reference on postmenopausal MHT. The term MHT typically includes estrogen replacement therapy (ERT) and estrogen-progestogen therapy (EPT). EPT can be sequential (Seq) when progestogen is added to ERT for 10-14 days a month, or continuous combined (CC) when progestogen is administered continuously every day along with a fixed amount of estrogen. MHT also includes Tibolone and the Tissue Selective Estrogen Complex (TSEC)

    Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η\eta|<0.8) and transverse momentum range 0.2< pTp_{\rm T}< 5.0 GeV/cc. The elliptic flow signal v2_2, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ±\pm 0.002 (stat) ±\pm 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v2(pT)_2(p_{\rm T}) reaches a maximum of 0.2 near pTp_{\rm T} = 3 GeV/cc. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

    Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

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    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at sNN\sqrt{s_{_{\rm NN}}} = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in η<0.8|\eta|<0.8 and 0.3<pT<200.3 < p_T < 20 GeV/cc are compared to the expectation in pp collisions at the same sNN\sqrt{s_{\rm NN}}, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAAR_{\rm AA}. The result indicates only weak medium effects (RAAR_{\rm AA} \approx 0.7) in peripheral collisions. In central collisions, RAAR_{\rm AA} reaches a minimum of about 0.14 at pT=6p_{\rm T}=6-7GeV/cc and increases significantly at larger pTp_{\rm T}. The measured suppression of high-pTp_{\rm T} particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

    European guideline (EuroGuiDerm) on atopic eczema – part II: non-systemic treatments and treatment recommendations for special AE patient populations

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    The evidence- and consensus-based guideline on atopic eczema was developed in accordance with the EuroGuiDerm Guideline and Consensus Statement Development Manual. Four consensus conferences were held between December 2020 and July 2021. Twenty-nine experts (including clinicians and patient representatives) from 12 European countries participated. This second part of the guideline includes recommendations and detailed information on basic therapy with emollients and moisturizers, topical anti-inflammatory treatment, antimicrobial and antipruritic treatment and UV photo- therapy. Furthermore, this part of the guideline covers techniques for avoiding provocation factors, as well as dietaryinterventions, immunotherapy, complementary medicine and educational interventions for patients with atopic eczema and deals with occupational and psychodermatological aspects of the disease. It also contains guidance on treatment for paediatric and adolescent patients and pregnant or breastfeeding women, as well as considerations for patients who want to have a child. A chapter on the patient perspective is also provided. The first part of the guideline, published sepa- rately, contains recommendations and guidance on systemic treatment with conventional immunosuppressive drugs, biologics and janus kinase (JAK) inhibitors, as well as information on the scope and purpose of the guideline, and a sec- tion on guideline methodology. Received: 17 February 2022; Accepted: 3 June 202

    Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388
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