Abstract This report presents the results from IUPAC Working Party IV.2.2 of the global trial within the framework of IUPAC Commission IV.2, “Characterization of Commercial Polymers”. The results were compared on the basis of molecular weight obtained by size exclusion chromatography (SEC)using different techniques practiced in participating laboratories, the majority of which were materials suppliers. The practical methodologies used different solvents for the polymers, in particular, benzyl alcohol, 1,1,1,3,3,3 hexafluoropropan-2-ol and tetrahydrofuran; the latter solvent was used after chemical modification of the polyamides, in general with trifluoroacetic anhydride. Eight laboratories participated in the trial. The repeatability for molecular weight in each laboratory was good, whatever technique was used, the relative standard deviation averaged over all laboratories being around 3%. The deviations in distribution of molecular weights with different experimental methodologies were broader, but were reasonably good despite the diversity of methods. The differences in the distribution correspond to a confidence interval of about 30% in molecular weight.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIonically modified electrodes for use in nonpolar fluidsDavid E. Niehaus, R. Mark. Wightman, and Paul A. FlowersCite this: Anal. Chem. 1991, 63, 17, 1728–1732Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Published inissue 1 September 1991https://pubs.acs.org/doi/10.1021/ac00017a014https://doi.org/10.1021/ac00017a014research-articleACS PublicationsRequest reuse permissionsArticle Views105Altmetric-Citations17LEARN 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 optionsGet e-Alertsclose Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVoltammetry of ferrocene in supercritical carbon dioxide containing water and tetrahexylammonium hexafluorophosphateDavid Niehaus, Mark Philips, Adrian Michael, and R. Mark WightmanCite this: J. Phys. Chem. 1989, 93, 16, 6232–6236Publication Date (Print):August 1, 1989Publication History Published online1 May 2002Published inissue 1 August 1989https://pubs.acs.org/doi/10.1021/j100353a052https://doi.org/10.1021/j100353a052research-articleACS PublicationsRequest reuse permissionsArticle Views358Altmetric-Citations63LEARN 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
Clinical stage 1 (CS1) nonseminomatous (NS) germ cell tumors involve a 30% probability of relapse upon surveillance. Adjuvant chemotherapy with one course of bleomycin, etoposide, and cisplatin (1xBEP) can reduce this risk to <5%. However, 1xBEP results are based solely on five controlled trials from high-volume centers. We analyzed the outcome in a real-life population.In a multicentric international study, 423 NS CS1 patients receiving 1xBEP were retrospectively evaluated. Median follow-up was 37 (range, 6-89) months. Primary end points were relapse-free and overall survival evaluated after 5 years. We also looked at associations of relapse with clinico-pathological factors using stratified Kaplan-Meier methods and Cox regression models. Treatment modality and outcome of recurrences were analyzed descriptively.The 5-year relapse-free survival rate was 96.2%. Thirteen patients (3.1%; 95% confidence interval, 1.65-5.04%) relapsed after a median time of 13 months, of which 10 were salvaged (77%). Relapses were mostly confined to retroperitoneal nodes. Three patients succumbed, two to disease progression and one to toxicity of chemotherapy. Pathological stage >pT2 was significantly associated with relapse rate.The relapse rate of 3.1% found in this population of NS CS1 patients treated with 1xBEP at the routine care level was not inferior to the median rate of 2.3% reported from a meta-analysis of controlled trials. Also, the cure rate of relapses of 77% is consistent with the previously reported rate of 80%. This study clearly shows that the 1xBEP regimen represents a safe treatment for NS CS1 patients.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnzyme-modified organic conducting salt microelectrodeJodi L. Kawagoe, David E. Niehaus, and R. Mark. WightmanCite this: Anal. Chem. 1991, 63, 24, 2961–2965Publication Date (Print):December 15, 1991Publication History Published online1 May 2002Published inissue 15 December 1991https://doi.org/10.1021/ac00024a029RIGHTS & PERMISSIONSArticle Views218Altmetric-Citations49LEARN 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 (1 MB) Get e-Alerts Get e-Alerts
This report presents the results from IUPAC Working Party IV.2.2 of the global trial within the framework of IUPAC Commission IV.2, “Characterization of Commercial Polymers”. The results were compared on the basis of molecular weight obtained by size exclusion chromatography (SEC) using different techniques practiced in participating laboratories, the majority of which were materials suppliers. The practical methodologies used different solvents for the polymers, in particular, benzyl alcohol, 1,1,1,3,3,3-hexafluoropropan-2-ol and tetrahydrofuran; the latter solvent was used after chemical modification of the polyamides, in general with trifluoroacetic anhydride. Eight laboratories participated in the trial. The repeatability for M̅w in each laboratory was good, whatever technique was used, the relative standard deviation averaged over all laboratories being around 3 %. The deviations in distribution of molecular weights with different experimental methodologies were broader, but were reasonably good despite the diversity of methods. The differences in the distribution correspond to a confidence interval of about 30 % in M̅w.
