Utilization of volcanic ejecta as a high-performance supplementary cementitious material by gravity classification and pulverization

The reaction of natural pozzolans is caused by volcanic glass composed of amorphous silicate; however, volcanic ejecta also contains crystal mineral, pumice, and sometimes weathered clay fraction in their natural conditions. By focusing on the differences of physical properties between these components, high-purity volcanic glass powder (VGP) was manufactured by dry gravity classification and pulverization. This paper reports the results of investigations to utilize pyroclastic flow deposits as a supplementary cementitious material (SCM). Through this method, the glass content of VGP increased to 88% with a mean particle size of 1 μm, when that of the raw material is about 60%. Chemical analysis indicated that VGP is principally composed of silica (about 72%) and alumina (about 13%). The performance of VGP as a SCM was evaluated by conducting tests on concrete mixtures, replacing 0% to 30% by weight of portland cement by VGP with a 20% to 60% water to cement ratio. VGP concrete showed better results of 7-and 28-day compressive strength compared to control concrete in all experiments. In particular, VGP demonstrated better flowability and strength development in concrete with a low water-binder ratio in comparison to silica fume

Evaluation of two prognostic indices for adult T‐cell leukemia/lymphoma in the subtropical endemic area, Okinawa, Japan

Aggressive adult T‐cell leukemia/lymphoma (ATL) has an extremely poor prognosis and is hyperendemic in Okinawa, Japan. This study evaluated two prognostic indices (PIs) for aggressive ATL, the ATL‐PI and Japan Clinical Oncology Group (JCOG)‐PI, in a cohort from Okinawa. The PIs were originally developed using two different Japanese cohorts that included few patients from Okinawa. The endpoint was overall survival (OS). Multivariable Cox regression analyses in the cohort of 433 patients revealed that all seven factors for calculating each PI were statistically significant prognostic predictors. Three‐year OS rates for ATL‐PI were 35.9% (low‐risk, n = 66), 10.4% (intermediate‐risk, n = 256), and 1.6% (high‐risk, n = 111), and those for JCOG‐PI were 22.4% (moderate‐risk, n = 176) and 5.3% (high‐risk, n = 257). The JCOG‐PI moderate‐risk group included both the ATL‐PI low‐ and intermediate‐risk groups. ATL‐PI more clearly identified the low‐risk patient subgroup than JCOG‐PI. To evaluate the external validity of the two PIs, we also assessed prognostic discriminability among 159 patients who loosely met the eligibility criteria of a previous clinical trial. Three‐year OS rates for ATL‐PI were 34.5% (low‐risk, n = 42), 9.2% (intermediate‐risk, n = 109), and 12.5% (high‐risk, n = 8). Those for JCOG‐PI were 22.4% (moderate‐risk, n = 95) and 7.6% (high‐risk, n = 64). The low‐risk ATL‐PI group had a better prognosis than the JCOG‐PI moderate‐risk group, suggesting that ATL‐PI would be more useful than JCOG‐PI for establishing and examining novel treatment strategies for ATL patients with a better prognosis. In addition, strongyloidiasis, previously suggested to be associated with ATL‐related deaths in Okinawa, was not a prognostic factor in this study