No abstract

To clear up the detailed mechanism of the alternating copolymerization of styrene (St) and maleic anhydride (MAn) concerning the initiation species, the propagation species, the tendency of the chain transfer reaction as well as the directional tendency of the reaction between copolymer radicals and monomer complexes, the role of the charge transfer complexes, characterization of end groups and additional donor effects were examined.The equilibrium constant of the St/MAn (1 : 1) complex was determined to be 0.31 by NMR spectroscopy, that suggested considerable amounts of complexes existing in the system. As expected, a small quantity of initiator (1%-azobisisobutyronitrile (AIBN)) was incorporated into the St/MAn copolymer. Chlorine atoms were scarcely incorporated into the copolymer synthesized in CCl4 with AIBN or benzoyl peroxide (BPO) as an initiator. Hence the copolymerization was considered to be induced only by attacke of initiator radicals to the monomer or the complexes, contrary to the usual conception of telomerization.When the electron donor monomer was added to the system, the terpolymerization could be treated as a copolymerization of the two complexes, i e . , St/MAn and Donor/MAn. By adding naphthalene the rate maximum point shifted from higher concentration of MAn to the equivalent concentration of St and MAn. Degradative chain transfer to N.N-dimethylaniline was observed, confirming the existance of poly-MAn radicals.It was suggested from these results that the charge transfer complex and uncomplexed MAn took part in the copolymerization of S t and MAn. This was proved kinetically. The whole mechanism was discussed. ZUSAMMENFASSUNG: Um den Mechanismus der alternierenden Copolymerisation von Styrol (St) und Maleinsaureanhydrid (MAn) in bezug auf die Art der Initiierung und des Wachstums, die Neigung zu Ketteniibertragungsreaktionen und Richtungstendenzen der Reaktion zwischen den Copolymerradikalen und den Monomerkomplexen aufzuklaren, wurden die Rolle der Elektronendonator/-akzeptor-Komplexe, die Charakterisierung der Endgruppen und Donatoreffekte untersncht. Die Gleichgewichtskonstante des St/MAn(l : 1)-Komplexes wurde durch NMR-Spektroskopie zu 0,31 bestimmt. Das bedeutet, dal3 betrachtliche Mengen von Komplexen in dem System existieren. Eine kleine Menge des Initiators (1%-Azoisobuttersaiuredinitril (AIBN)) wurde, wie erwartet, in das St/MAn-Copolymere eingebaut. Chloratome wurden so gut wie nicht in das mit AIBN oder Dibenzoylperoxid (BPO) als Initiator in C C 4 synthetisierte 265 E. TSUCHIDA and T. TOMONO Copolymere eingebaut. Es wurde daher die Copolymerisation nur als durch den AngrifT der Initiatorradikale auf das Monomere oder die Komplexe gestartet betrachtet, im Gegensatz zum iiblichen Konzept der Telomerisation. Wenn ein Elektronendonator-Monomeres dem System hinzugefiigt wurde, konnte die Terpolymerisation als Copolymerisation der beiden Komplexe St/MAn und Donator/MAn betrachtet werden. Bei Zugabe von Naphthalin wurde die maximale Copolymerisationsgeschwindigkeit von hoheren MAn-...

These data suggest that viruses in the presence of certain kinds of amino acids could be aggregated and effectively removed by a filter that has a pore size larger than the size of the viruses.

Abstract:The first nationwide nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-l) of voluntarily donated blood after serological pre-screening and before release of cellular components and plasma for fractionation was implemented by the Japanese Red Cross Blood Transfusion Services. From February 1, 2000 to April 30, 2001, specimens from 6,805,010 units of serologically negative donation were screened in minipools of 50 samples within 24 hr after blood donation by NAT using multiplex HBV/HCV/HIV-l reagent for blood transfusion including short shelf-life platelets. Among them, 112 HBV DNA-positives, 25 HCV RNA positives and 4 HIV-l RNA positives were screened out and we could prevent transfusion of these NAT positive units. Subtypes/genotypes of HBV DNA, adr/C, adw/A, adwlB, adw/C, ayr/C and aywlD were found and adr/C was predominant. A total of 61.6 % of them (69/112) were negative by overnight EIA. Sixth three of HBV NATpositive samples carried virus loads less than 10 4 copies ImL and 92.1 % of them (58/63) were negative by overnight EIA. The virus growth curves of HBV in 6 cases obtained by retrospective and prospective follOW-Up study showed exponential straight lines in the early stage of serological window periods and the log times ofHBV growth (10 fold increase) in serological window period were between 4.6 and 7.6 days. NAT screening with highly sensitive reagents in pool of specimens is useful to exclude blood units with low level of HBV and HBV mutants from blood transfusion.

The virus-clearance efficiency of the FVIII product, CROSS EIGHT M, was markedly increased, in particular against small non-enveloped viruses, by changing the virus filter pore size from 35 nm to 20 nm. It was possible to implement the 20-nm pore-size filter without variation of the biochemical properties or a serious loss of FVIII.