Поведение радионуклида 106Ru в водных растворах при центрофугировании, ультрафильтрации и ионном обмене

The paper presents the results of 106Ru radionuclide behavior regularities study in aqueous solutions in a wide pH range by ultrafiltration, ion exchange and centrifugation methods. The regions of 106Ru various species existence in solution have been established: cationic 106Ru species at pH < 3.5; the transition region of non-ionic species formation in the range of pH 3.5–4.2 and the region of non-ionic species predominant formation at pH > 4.2. A characteristic feature of the studied solutions is the formation of non-ionic particles by microconcentrations of 106Ru via pseudocolloids at lower pH values as compared to ruthenium solutions with a concentration of 10-6–10-4 mol/dm3. The established regularities of the behavior of ruthenium radionuclides can be utilized to increase the efficiency of ion exchange and membrane separation methods at nuclear and radiation facilities for technological solutions and liquid radioactive waste treatment.Представлены результаты изучения закономерности поведения радионуклида 106Ru в водных растворах в широком интервале рН методами ультрафильтрации, ионного обмена и центрифугирования. Установлены области существования различных форм 106Ru в растворе: катионные формы 106Ru существуют при рН < 3,5; переходная область формирования неионных форм находится в интервале рН 3,5–4,2 и область преимущественного образования неионных форм при рН > 4,2. Характерной особенностью изученных растворов является образование рутением-106 концентрацией 10-11 моль/дм3 неионных частиц за счет псевдоколлоидообразования при более низких значениях рН по сравнению с растворами рутения в концентрации 10-6–10-4 моль/дм3. Установленные закономерности поведения радионуклидов рутения могут быть использованы для повышения эффективности способов ионного обмена и мембранного разделения при очистке технологических растворов и жидких радиоактивных отходов, образующихся на ядерных и радиационных объектах

Формы нахождения радионуклида кобальта-60 в растворах борной кислоты

In this work, the speciation of 60Co radionuclide in model solution of spent fuel pool coolant is studied by ultrafiltration and centrifugation. The effect of pH and composition of the solution on the 60Co radionuclide speciation is shown; the limitss in existence of ionic and non-ionic (pseudocolloidal) forms are defined. A great part of 60Co states at ionic form represented by hydrated cation of 60Co in the solutions of boric acid 20 g/L at 4–8 pH value. The size of non-ionic forms of 60Co in this pH range is 1–50 nm. Starting with pH 8, the соntent of non-ionic forms increases dramatically and reaches 100 % at pH value 10–11, which is due to formation of CoOH+ ions and their increased sorption activity at forming pseudocolloids. Introduction of iron (III) ions to the solution, which are precursors of corrosion products, shifts the formation of nonionic forms of 60Co to lower pH area.Исследовано состояние радионуклида 60Co в модельных растворах теплоносителя бассейна выдержки отработавшего ядерного топлива с использованием методов ультрафильтрации и центрифугирования. Показано влияние pH и состава раствора на формы нахождения радионуклида 60Co, установлены границы существования ионных и неионных (псевдоколлоидных) форм. В растворах борной кислоты 20 г/л при рН 4–8 большая часть 60Co находится в ионном состоянии в виде гидратированного катиона Co2+. Размер неионных форм кобальта в данном интервале рН составляет 1–50 нм. Начиная с рН 8 доля неионных форм резко увеличивается и достигает 100 % при рН 10–11, что связано с образованием ионов CoOH+ и их повышенной сорбционной активностью при образовании псевдоколлоидов. Внесение в раствор ионов железа (III), являющихся предшественниками продуктов коррозии, сдвигает образование неионных форм 60Co в более низкую область pH

Oral ixazomib maintenance following autologous stem cell transplantation (TOURMALINE-MM3): a double-blind, randomised, placebo-controlled phase 3 trial

Background: Maintenance therapy following autologous stem cell transplantation (ASCT) can delay disease progression and prolong survival in patients with multiple myeloma. Ixazomib is ideally suited for maintenance therapy given its convenient once-weekly oral dosing and low toxicity profile. In this study, we aimed to determine the safety and efficacy of ixazomib as maintenance therapy following ASCT. Methods: The phase 3, double-blind, placebo-controlled TOURMALINE-MM3 study took place in 167 clinical or hospital sites in 30 countries in Europe, the Middle East, Africa, Asia, and North and South America. Eligible participants were adults with a confirmed diagnosis of symptomatic multiple myeloma according to International Myeloma Working Group criteria who had achieved at least a partial response after undergoing standard-of-care induction therapy followed by high-dose melphalan (200 mg/m2) conditioning and single ASCT within 12 months of diagnosis. Patients were randomly assigned in a 3:2 ratio to oral ixazomib or matching placebo on days 1, 8, and 15 in 28-day cycles for 2 years following induction, high-dose therapy, and transplantation. The initial 3 mg dose was increased to 4 mg from cycle 5 if tolerated during cycles 1–4. Randomisation was stratified by induction regimen, pre-induction disease stage, and response post-transplantation. The primary endpoint was progression-free survival (PFS) by intention-to-treat analysis. Safety was assessed in all patients who received at least one dose of ixazomib or placebo, according to treatment actually received. This trial is registered with ClinicalTrials.gov, number NCT02181413, and follow-up is ongoing. Findings: Between July 31, 2014, and March 14, 2016, 656 patients were enrolled and randomly assigned to receive ixazomib maintenance therapy (n=395) or placebo (n=261). With a median follow-up of 31 months (IQR 27·3–35·7), we observed a 28% reduction in the risk of progression or death with ixazomib versus placebo (median PFS 26·5 months [95% CI 23·7–33·8] vs 21·3 months [18·0–24·7]; hazard ratio 0·72, 95% CI 0·58–0·89; p=0·0023). No increase in second malignancies was noted with ixazomib therapy (12 [3%] patients) compared with placebo (eight [3%] patients) at the time of this analysis. 108 (27%) of 394 patients in the ixazomib group and 51 (20%) of 259 patients in the placebo group experienced serious adverse events. During the treatment period, one patient died in the ixazomib group and none died in the placebo group. Interpretation: Ixazomib maintenance prolongs PFS and represents an additional option for post-transplant maintenance therapy in patients with newly diagnosed multiple myeloma. Funding: Millennium Pharmaceuticals, a wholly owned subsidiary of Takeda Pharmaceutical Company

Oral ixazomib maintenance following autologous stem cell transplantation (TOURMALINE-MM3): a double-blind, randomised, placebo-controlled phase 3 trial

Background: Maintenance therapy following autologous stem cell transplantation (ASCT) can delay disease progression and prolong survival in patients with multiple myeloma. Ixazomib is ideally suited for maintenance therapy given its convenient once-weekly oral dosing and low toxicity profile. In this study, we aimed to determine the safety and efficacy of ixazomib as maintenance therapy following ASCT. Methods: The phase 3, double-blind, placebo-controlled TOURMALINE-MM3 study took place in 167 clinical or hospital sites in 30 countries in Europe, the Middle East, Africa, Asia, and North and South America. Eligible participants were adults with a confirmed diagnosis of symptomatic multiple myeloma according to International Myeloma Working Group criteria who had achieved at least a partial response after undergoing standard-of-care induction therapy followed by high-dose melphalan (200 mg/m2) conditioning and single ASCT within 12 months of diagnosis. Patients were randomly assigned in a 3:2 ratio to oral ixazomib or matching placebo on days 1, 8, and 15 in 28-day cycles for 2 years following induction, high-dose therapy, and transplantation. The initial 3 mg dose was increased to 4 mg from cycle 5 if tolerated during cycles 1–4. Randomisation was stratified by induction regimen, pre-induction disease stage, and response post-transplantation. The primary endpoint was progression-free survival (PFS) by intention-to-treat analysis. Safety was assessed in all patients who received at least one dose of ixazomib or placebo, according to treatment actually received. This trial is registered with ClinicalTrials.gov, number NCT02181413, and follow-up is ongoing. Findings: Between July 31, 2014, and March 14, 2016, 656 patients were enrolled and randomly assigned to receive ixazomib maintenance therapy (n=395) or placebo (n=261). With a median follow-up of 31 months (IQR 27·3–35·7), we observed a 28% reduction in the risk of progression or death with ixazomib versus placebo (median PFS 26·5 months [95% CI 23·7–33·8] vs 21·3 months [18·0–24·7]; hazard ratio 0·72, 95% CI 0·58–0·89; p=0·0023). No increase in second malignancies was noted with ixazomib therapy (12 [3%] patients) compared with placebo (eight [3%] patients) at the time of this analysis. 108 (27%) of 394 patients in the ixazomib group and 51 (20%) of 259 patients in the placebo group experienced serious adverse events. During the treatment period, one patient died in the ixazomib group and none died in the placebo group. Interpretation: Ixazomib maintenance prolongs PFS and represents an additional option for post-transplant maintenance therapy in patients with newly diagnosed multiple myeloma. Funding: Millennium Pharmaceuticals, a wholly owned subsidiary of Takeda Pharmaceutical Company. © 2019 Elsevier Lt