141 research outputs found

    Stratification and Isotope Separation in CP Stars

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    We investigate the elemental and isotopic stratification in the atmospheres of selected chemically peculiar (CP) stars of the upper main sequence. Reconfiguration of the UVES spectrograph in 2004 has made it possible to examine all three lines of the Ca II infrared triplet. Much of the material analyzed was obtained in 2008. We support the claim of Ryabchikova, Kochukhov & Bagnulo (RKB) that the calcium isotopes have distinct stratification profiles for the stars 10 Aql, HR 1217, and HD 122970, with the heavy isotope concentrated toward the higher layers. Better observations are needed to learn the extent to which Ca-40 dominates in the deepest layers of all or most CP stars that show the presence of Ca-48. There is little evidence for Ca-40 in the spectra of some HgMn stars, and the infrared triplet in the magnetic star HD 101065 is well fit by pure Ca-48. In HR 5623 (HD 133792) and HD 217522 it is likely that the heavy isotope dominates, though models are possible where this is not the case. While elemental stratification is surely needed in many cases, we point out the importance of including adjustments in the assumed Teff and log(g) values, in attempts to model stratification. We recommend emphasis on profiles of the strongest lines, where the influence of stratification is most evident. Isotopic mixtures, involving the 4 stable calcium nuclides with masses between 40 and 48 are plausible, but are not emphasized.Comment: 16 Pages, 20 Figures, 10 Tables. Accepted for publication in Monthly Notices of the RA

    New Whole Earth Telescope observations of CD-24 7599: steps towards δ Scuti star seismology

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    92 h of new Whole Earth Telescope observations have been acquired for the δ Scuti star CD-24 7599. All the seven pulsation modes reported by Handler et al. are confirmed. However, significant amplitude variations which are not caused by beating of closely spaced frequencies occurred within two years. Analysing the combined data of both WET runs, we detect six further pulsation modes, bringing the total number up to 13. We also examine our data for high-frequency pulsations similar to those exhibited by rapidly oscillating Ap stars, but we do not find convincing evidence for variability in this frequency domai

    Safety, tolerability and efficacy of peginterferon alpha-2a and ribavirin in chronic hepatitis C in clinical practice: The German Open Safety Trial

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    The combination treatment of peginterferon alpha-2a (PEG-IFN alpha-2a; Pegasys®) plus ribavirin (RBV) is recommended as a standard care for HCV infections. Side effects and aspects of efficacy and safety have to be balanced. This study evaluates clinical practice data on safety and efficacy of HCV treatment with PEG-IFN in combination with RBV over 24 and 48 weeks. This study was a phase III, multi-centre, open-label study with two treatment groups: PEG-IFN in combination with RBV for 24 or 48 weeks. The allocation to the treatment groups was at the discretion of the investigator; 309 patients entered active treatment: 90 patients received PEG-IFN plus RBV for 24 weeks and 219 patients PEG-IFN plus RBV for 48 weeks. A sustained virological response (SVR) was achieved in 48.9% of all patients. Genotype 1 patients with a 48-week combination treatment achieved an SVR of 39.9%. In the 48-week group a low baseline viral load was associated with a higher SVR rate (47.0% vs. 32.4%). For genotype 2 or 3 patients, the SVR was 67.9%. For these patients there was no relevant difference between patients with low and high viral loads; 97.7% of the patients experienced at least one adverse event. The incidence of serious adverse events was distinctly lower in the 24-week group (4.4% vs. 10.5%). This investigation confirms the well-known risk–benefit ratio found in controlled studies in a clinical practice setting. The safety profile is similar and shows the highest incidence of adverse events in the first 12 weeks of treatment

    Novel foods in the European Union: Scientific requirements and challenges of the risk assessment process by the European Food Safety Authority

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    The European Food Safety Authority (EFSA) has been involved in the risk assessment of novel foods since 2003. The implementation of the current novel food regulation in 2018 rendered EFSA the sole entity of the European Union responsible for such safety evaluations. The risk assessment is based on the data submitted by applicants in line with the scientific requirements described in the respective EFSA guidance document. The present work aims to elaborate on the rationale behind the scientific questions raised during the risk assessment of novel foods, with a focus on complex mixtures and whole foods. Novel foods received by EFSA in 2003–2019 were screened and clustered by nature and complexity. The requests for additional or supplementary information raised by EFSA during all risk assessments were analyzed for identifying reoccurring issues. In brief, it is shown that applications concern mainly novel foods derived from plants, microorganisms, fungi, algae, and animals. A plethora of requests relates to the production process, the compositional characterization of the novel food, and the evaluation of the product's toxicological profile. Recurring issues related to specific novel food categories were noted. The heterogeneous nature and the variable complexity of novel foods emphasize the challenge to tailor aspects of the evaluation approach to the characteristics of each individual product. Importantly, the scientific requirements for novel food applications set by EFSA are interrelated, and only a rigorous and cross-cutting approach adopted by the applicants when preparing the respective application dossiers can lead to scientifically sound dossiers. This is the first time that an in-depth analysis of the experience gained by EFSA in the risk assessment of novel foods and of the reasoning behind the most frequent scientific requests by EFSA to applicants is made

    Safety of apple fruit cell culture biomass as a novel food pursuant to Regulation (EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of an apple fruit cell culture biomass as a novel food (NF) pursuant to Regulation (EU) 2015/2283 and intended as an ingredient for food supplements in adults. The cells have been sourced from the callus grown on a piece of apple placed on a solid medium under sterile conditions. The de-differentiated apple cells are then cultivated in liquid medium. The medium contains sucrose, vitamins, minerals, trace elements and the two synthetic plant hormone analogues, benzylaminopurine (< 0.1 mg/kg) and 2,4-dichlorophenoxyacetic acid (< 0.25 mg/kg). These plant hormones are regulated under the EU pesticide legislation and their residue levels in the NF are in compliance with the EU maximum residue levels. The main components of the NF are carbohydrates (including sugars and non-digestible carbohydrates), ash, proteins and smaller amounts of fatty acids and organic acids. Except for the amount of total fat and the organic acids (succinic and l-malic acid), the quantities of the compositional parameters of the NF and apple have little in common. The Panel considers that a provided subchronic toxicity study was not needed to establish the safety of this NF, when taking into account the source of the NF, i.e. apples, the production process, the low intended use level and the composition of the NF, despite the noted differences to apple. The Panel considers that the NF contains proteins, which were not detected in apple and which may be allergenic. The Panel concludes that the NF, an apple fruit cell culture biomass, is safe under the proposed conditions of use

    Safety of hot water extract of fruits and peduncles of Hovenia dulcis as a novel food pursuant to Regulation 1(EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of ‘Hovenia dulcis fruit extract’ as a novel food (NF) for its use in food supplements. The NF concerns a hot water extract of sliced and dried fruits and peduncles of Hovenia dulcis Thun. The production process is described in sufficient detail but contains contradictory information regarding the mixing with another ingredient of the NF. The NF is comprised of mostly carbohydrates (about 90%), about 2% proteins, 5% moisture, less than 1% fat and about 2% ash. In addition, the NF contains small amounts of flavonoids such as dihydromyricetin, myricetin and quercetin. The Panel notes limitations of the data provided from the batch testing regarding proximate analyses and plant secondary metabolites. Given these limitations, the Panel considers that the data provided by the applicant do not demonstrate that different batches produced with the described production process meet the proposed specifications. The target population is the general adult population excluding pregnant and lactating women and people with a chronic disease, such as liver malfunction. Limited information was provided on a history of consumption of Hovenia dulcis fruits and on an extract approved in South Korea. A number of toxicological studies were performed. However, the study reports did not allow to verify that the test item was representative of the NF. The same applied to a human study provided by the applicant. The Panel concludes that the safety of the NF has not been established

    Safety of the extension of use of plant sterol esters as a novel food pursuant to Regulation (EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of an extension of use of the novel food ‘plant sterol esters’ when added to vegetable fat spreads and to liquid vegetable fat-based emulsions for cooking and baking purposes pursuant to Regulation (EU) 2015/2283. Member States expressed concerns in relation to plant sterol oxidation products (POP) and consumption by non-target population groups. The median (0.5%) and P90 (2.28%) value of the oxidation rates of plant sterols determined by a wide range of cooking experiments were used together with exposure estimates for plant sterol when added and cooked with vegetable fat spreads and liquids. The no-observed adverse effect level (NOAEL) of a subchronic rat study and an applied default uncertainty factor of 200 served to derive levels (i.e. 0.64 mg POP/kg body weight (bw) per day) considered safe for humans. This safe level of exposure would be exceeded at the P95 by all age groups when considering the P90 oxidation rate and using EFSA's comprehensive food consumption database for assessing the potential exposure. When considering the median oxidation rate, the safe level of 0.64 mg POP/kg bw per day would be exceeded at the highest P95 intake estimates in children below 9 years of age. When considering an intake of the maximum authorised use level of 3 g plant sterols/person per day and oxidation rates of 0.5% and 2.28%, the resulting daily POP intakes per kg bw by an adult weighing 70 kg would be 0.21 and 0.98 mg/kg bw per day, respectively, the latter value exceeding 0.64 mg/kg bw per day. The Panel concludes that the safety of the intended extension of use of plant sterol esters under the proposed conditions of use has not been established

    Safety of bovine milk osteopontin as a Novel food pursuant to Regulation (EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on bovine milk osteopontin (bmOPN) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF concerns OPN derived from bovine whey. The NF is intended to be used at a maximum use level of 151 mg/L, in infant formula (IF), follow-on formula (FoF) and ready-to-eat dairy-based meals for children up to 35 months of age. As compared to the concentrations naturally present in cow’s milk and concentrations found in IF on the market reported in the literature, the proposed use level of the NF represents an about 10-fold higher concentration of bmOPN. The intended use levels of the NF would provide bmOPN at a concentration within the range of human milk (hm) OPN. In a 6-month study, 14, 72 and 140 mg bmOPN/L in reconstituted (as consumed) IF were given to 279 infants in order to study possible effects on frequency and severity of adverse events, and growth, formula intake and stool consistency. Despite that a number of inconsistencies and limitations were noted in the study report, the Panel considers that the results obtained from this study do not raise safety concerns. Considering the source of the NF, that neither the toxicological studies nor the provided infant study do raise safety concerns, and the low bmOPN plasma levels in infants resulting from the consumption of the NF, the Panel considers that the margin of exposure (i.e. 36) between the NOAEL of the subchronic toxicity study (1,200 mg/kg bw per day) and the highest P95 estimate for infants (33.4 mg/kg bw per day) is sufficient. The Panel concludes that the NF is safe under the proposed conditions of use

    Safety of Cetylated Fatty Acids as a Novel Food pursuant to Regulation (EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on an application for cetylated fatty acids as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF concerns primarily a mixture of cetylated myristic acid and cetylated oleic acid synthesised from cetyl alcohol, myristic acid and oleic acid, and to a lesser degree, other cetylated fatty acids and other compounds from olive oil. The NF is intended for use in food supplements for the general adult population. The highest dose tested in a subchronic toxicity study in rats, i.e. 4,500 mg/kg per day, was considered to be the no-observed-adverse effect level. By applying the default uncertainty factor of 200 as suggested by the EFSA Scientific Committee (2012), and considering a default body weight of 70 kg for the adult target population, this would result in an intake of 1.6 g per day, which is lower than the maximum intake proposed by the applicant (i.e. 2.1 g per day). The Panel concludes that the NF, cetylated fatty acids, is safe at an intake of 1.6 g per day for the intended target population, i.e. adults

    Safety of a change in specifications of the novel food oleoresin from Haematococcus pluvialis containing astaxanthin pursuant to Regulation (EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of a change of specifications of the novel food (NF) oleoresin from Haematococcus pluvialis containing astaxanthin (ATX) pursuant to Regulation (EU) 2015/2283. The NF is already authorised as ingredient for the use in food supplements as defined in Directive 2002/46EC in accordance to Regulation (EU) 2017/2470. The NF concerns an oleoresin which contains ~ 10% ATX, obtained by supercritical CO2 extraction of the homogenised and dried biomass of cultivated H. pluvialis. This NF has been assessed by the Panel in 2014. With the present dossier, the applicant proposed to lower the minimum specification limits for protein and ATX monoesters for the NF, and to increase the maximum specification limit for the relative amount of ATX diesters in total ATX. An increase of the maximum specification limit for the 9-cis isomer is also applied for. Although the data are limited regarding bioavailability and distribution in humans of these three naturally occurring ATX isomers, the available in vitro and in vivo data suggest that the 13-cis rather than the 9-cis ATX is selectively absorbed, i.e. has a higher bioavailability and/or possibly emerges from isomerisation of all-trans ATX. The Panel notes that the toxicity of the individual ATX isomers has not been studied individually. However, the ADI of 0.2 mg/kg, which was established for synthetic ATX and ATX from H. pluvialis, applies also for ATX in the oleoresin from H. pluvialis with the proposed changes of specifications. The Panel concludes that the NF, oleoresin from H. pluvialis containing ATX, is safe with the proposed specification limits
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