Apolipoproteins B and A-1 concentrations have been measured by radioimmunoassay in eluates of whole blood spotted on filter paper. The stability of apolipoproteins has been studied during a period of 2 months. Apolipoprotein levels are determined within 15 days after collection in order to avoid the significant decrease of B/A-1 ratio observed afterwards. The within-assay and between-assay CVs for middle concentrations are 6.4% and 6.8%, respectively, for apo B, and 8.2% and 13.5% for apo A-1. The coefficient of correlation between dried blood and plasma B/A-1 ratio is r2 = 0.907 (n=30). The apolipoprotein concentrations have been measured in 994 3-day-old newborns; the mean ± SD is 0.214±0.073 g/l (apo B), 0.495±0.147 g/l (apo A-1) and 0.453±0.164 (B/A-1 ratio). The apo B concentration is unaffected by birth weight or gestational age, but it is correlated with sex. Linear multivariate regression has been found for the apo A-1 concentration which is influenced by gestational age and by sex. Girls have higher levels than boys for both parameters (P<0.0001 for apo B; P=0.0037 for apo A-1). This radioimmunoassay technique for apolipoproteins meets the practical requirements of a neonatal screening program for familial hypercholesterolemia.

Dans le cadre du dépistage des hypothyroïdies congénitales, lors d'une élévation de la thyrotropine (TSH), les concentrations de thyroxine libre (T4 L) et triiodothyronine libre (T3 L) sont mesurées sur le même prélèvement de sang séché. Dans 18 cas d'hypothyroïdie définitive, les taux moyens de T4 L: 4,2 pmol/l (DS = 3,3) et de T3 L: 1,2 pmol/l (DS = 0,8) étaient significativement différents de ceux observés chez les nouveau-nés euthyroïdiens (T4 L: 27,0 pmol/l; DS = 7,5 et T3 L: 2,6 pmol/l; DS = 0,8). Les concentrations de TSH, T4 L et T3 L étaient significativement différentes entre les formes transitoires et les hypothyroïdies définitives (P < 0,001 pour TSH et T4 L, P < 0,01 pour T3 L). Ces méthodes rapides ont permis de débuter le traitement de façon précoce (moyenne d'âge: 9,5 j). Le suivi biologique des hypothyroïdiens traités est assuré par des contrôles réguliers et fréquents des trois hormones dans le sang séché pour une adaptation optimale des posologies au rythme de la croissance.

Nous avons adapté une technique de dosage radio-immunologique de la thyroxine libre (FT4) au sang séché sur papier filtre. Cette méthode présente de bonnes performances analytiques pour un volume d'échantillon réduit (5,5 μl de sang total) : CV intra- et interessais de 8,0 à 13,2%, limite de détection : 0,8 pmol/l, corrélation linéaire sang séché-plasma (r2 = 0,905). Une étude portant sur 1 978 nouveau-nés a permis d'établir l'histogramme de répartition des taux physiologiques et la moyenne chez les bébés euthyroïdiens : 27 pmol/l (DS = 7,5 pmol/l). À partir de ces résultats, nous proposons différentes valeurs pour le seuil inférieur du taux de FT4, permettant de limiter le nombre de rappels lors d'une élévation modérée de la TSH circulante. Les valeurs effondrées du taux de T4 libre observées chez quatre hypothyroïdiens (FT4 moyenne = 2,8 pmol/l) font de ce dosage un test de confirmation rapide et fiable dans le dépistage néonatal des hypothyroïdies.

We have adapted a new radioimmunoassay for free thyroxin (FT4) measurement in dried blood spots for use in neonatal screening for hypothyroidism. The method is easy, fast, and cheap. Within-assay and between-assay CVs are respectively 9.6% and 13.2%. In 997 neonates three days postpartum with normal thyrotropin concentrations, the mean FT4 concentration was 27.2 pmol/L (SD 7.3 pmol/L). There was no significant difference in mean FT4 concentration between boys and girls. FT4 concentrations increased linearly with birth weight or with gestational age, as expressed by multiple linear regression: FT4 (pmol/L) = 0.0016 birth weight (g) + 0.6931 gestational age (weeks) - 4.8772. Only gestational age significantly affected the FT4 value. For five hypothyroid infants tested on day three postpartum, FT4 values were all below the 1st percentile of values from healthy neonates. Thus, when the neonatal concentration of thyrotropin is above normal, FT4 measured in the same sample can provide a reliable earlier diagnosis of hypothyroidism.

Infrared spectra of irreversibly adsorbed species given by CF3CH2OH, CCl3CH2OH (D) and CCl3CHDOH on aluminas modified by addition of sodium or fluoride ions have been investigated in the 4000-1000 cm−1 range. They were compared to those obtained on pure alumina, in order to study the changes in acid—base properties. On sodium-treated aluminas, dissociative adsorption occurred; the wavenumbers of ν(CO) and ν(CH) vibrations of alcoholate species showed that the ionic character of COAl bonds increased with increasing sodium content up to 2.5% wt. It was deduced that Na+ introduction enhanced the basicity of adsorption sites. Similar effects were obtained when pure alumina samples were irreversibly pretreated with pyridine. On fluorinated aluminas, the study of the 1500-1000 cm−1 range evidenced formation of both alcoholate and non-dissociatively adsorbed species. As the latter gave rise to high frequency ν(CH) vibrations, it was concluded they were coordinately adsorbed. Addition of fluoride ions therefore increased the Lewis acidity of alumina samples.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMicrocalorimetric and Fourier transform infrared spectroscopic studies of methanol adsorption on aluminaGuido Busca, Pier Francesco Rossi, Vincenzo Lorenzelli, Mohammed Benaissa, Josette Travert, and Jean Claude LavalleyCite this: J. Phys. Chem. 1985, 89, 25, 5433–5439Publication Date (Print):December 1, 1985Publication History Published online1 May 2002Published inissue 1 December 1985https://doi.org/10.1021/j100271a024RIGHTS & PERMISSIONSArticle Views456Altmetric-Citations120LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (862 KB) Get e-Alerts

Les spectres infrarouges des espèces irréversiblement adsorbées données par CCI3CH2OH, CCI3CD2OH, CF3CH2OH, HC [math] CCH2OH et HC [math] CCD2OH sur alumine (activée à 880 K) et par CCI3CH2OD, CF3CH2OD et DC [math] CCH2OD sur AI2O3—OD sont analysés dans la région 4 000 — 1 000 cm— 1. La similitude des spectres obtenus par adsorption d'un alcool ROH et du composé ROD correspondant dans la région 1 500 — 1 000 cm— 1 montre sans ambigüité la formation d'espèces de type alcoolate. Ces espèces sont hétérogènes. L'utilisation d'échantillons d'alumine activés à 1 150 K permet de déterminer le nombre d'ondes ν (OH) des groupements hydroxyle résultant de l'adsorption dissociative. Dans les conditions opératoires utilisées (température d’adsorption : 310 K), la formation des espèces carboxylates peut être considérée comme négligeable. L'étude des vibrations ν (CH) ne permet pas de mettre en évidence la présence d'espèces coordinées. Dans le cas de l'adsorption de l'alcool propargylique, l'étude de la région des vibrations du groupement acétylénique montre que l'adsorption ne se fait pas par coupure de la liaison [math] C — H mais uniquement par dissociation de la liaison OH.

The adsorption of H2S, CH3SH and (CH3)2S has been studied by gravimetry and infrared spectroscopy. Some experiments have been carried out with preadsorbed pyridine as a poison. The results show that (CH3)2S is bonded to Lewis acid sites and that 60 µmol g–1 are irreversibly coordinated to stronger sites of this type. Dissociative chemisorption has been observed for H2S and CH3SH. Poisoning experiments lead us to conclude that the first adsorption steps involve either a coordinative adsorption (ca. 30 µmol g–1) or a hydrogen bond between a surface basic oxygen atom and the H atom of the SH bond (ca. 50 µmol g–1). The reversible adsorption of CH3SH is thought to occur by these two processes besides another one in which the S atom is H bonded to a hydroxyl surface group. These results clarify the nature of the adsorption sites of alumina.

Les spectres des espèces réversiblement adsorbées données par CCI3CH2OH, CCI3CD2OH, CF3CH2OH, HC [math] CCH2OH et HC [math] CCD2OH sur alumine activée à 880 K et à 1 150 K sont semblables : les groupements hydroxyle restant sur l'alumine après activation à 880 K n'interviennent donc pas dans le processus d'adsorption réversible des alcools. Sans exclure la formation d'espèces coordinées, l'examen des spectres permet de conclure à la présence d'espèces liées par ponts hydrogène. Nous montrons que certains groupements hydroxyle jouant le rôle de donneur de proton proviennent de l'adsorption dissociative irréversible des alcools. Seule cependant une partie de ces groupements hydroxyle est mise en jeu, ce qui confirme l'hétérogénéité des espèces résultant de l'adsorption irréversible des alcools, donc l'hétérogénéité des sites de l’alumine. Les ponts hydrogène sont plus forts que ceux observés pour les alcools à l'état liquide pur : l'adsorption irréversible s'accompagne donc, du moins pour certains d'entre eux, d'une augmentation de l'acidité des OH formés par rapport à celle des alcools de départ.

Chemischer InformationsdienstVolume 12, Issue 17 Article ChemInform Abstract: IR-UNTERSUCHUNG DER ADSORPTION VON ALKOHOLEN AN AL2O3. 1. MITT. IRREVERSIBLE ADSORPTION VON 2,2,2-TRIHALOGEN-ETHANOLEN UND PROPARGYLALKOHOL. 2. MITT. REVERSIBLE ADSORPTION VON 2,2,-TRIHALOGEN-ETHANOLEN UND PROPARGYLALKOHOL J. TRAVERT, J. TRAVERTSearch for more papers by this authorJ.-C. LAVALLEY, J.-C. LAVALLEYSearch for more papers by this authorO. SAUR, O. SAURSearch for more papers by this authorJ. LAMOTTE, J. LAMOTTESearch for more papers by this author J. TRAVERT, J. TRAVERTSearch for more papers by this authorJ.-C. LAVALLEY, J.-C. LAVALLEYSearch for more papers by this authorO. SAUR, O. SAURSearch for more papers by this authorJ. LAMOTTE, J. LAMOTTESearch for more papers by this author First published: April 28, 1981 https://doi.org/10.1002/chin.198117119AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume12, Issue17April 28, 1981 RelatedInformation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdsorption of alcohols on alumina. 1. Gravimetric and infrared spectroscopic investigation. CommentJean-Claude Lavalley, Jack Caillod, and Josette TravertCite this: J. Phys. Chem. 1980, 84, 16, 2083–2084Publication Date (Print):August 1, 1980Publication History Published online1 May 2002Published inissue 1 August 1980https://pubs.acs.org/doi/10.1021/j100453a017https://doi.org/10.1021/j100453a017research-articleACS PublicationsRequest reuse permissionsArticle Views65Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts