5 research outputs found
Optimization and first electronic implementation of the Constant-Fraction Time-Over-Threshold pulse shape discrimination method
In this contribution we report on further investigations of the
recently-evaluated Constant-Fraction Time-over-Threshold (CF-ToT) method for
neutron/gamma-ray pulse shape discrimination (PSD). The superiority of the
CF-ToT PSD method over the constant-threshold (CT-ToT) method was previously
demonstrated, down to low neutron energy thresholds of 100 keVee. Here, we
report on a quantitative comparison between the traditionally used Charge
Comparison (CC) method and the CF-ToT method using a stilbene scintillator
coupled to a silicon photomultiplier, implementing an offline analysis of
recorded fast-neutron and gamma-ray waveforms. An optimization of the constant
fraction value indicates that a 20%-fraction yields the optimum figure-of-merit
(FOM) and gamma-ray peak-to-valley (P/V) ratio. The results obtained for a
particle energy threshold of 100 keVee show that the FOM and P/V values
achieved with the CF-ToT method are superior to those obtained using the
standard CC method. In addition, a first electronic implementation of the
CF-ToT method was performed using simple circuitry suitable for multichannel
architecture. Initial results obtained with this circuit prototype are
presented.Comment: 10 pages, 8 figures. To be submitted to JINS
Single cell dissection of plasma cell heterogeneity in symptomatic and asymptomatic myeloma
Multiple myeloma, a plasma cell malignancy, is the second most common blood cancer. Despite extensive research, disease heterogeneity is poorly characterized, hampering efforts for early diagnosis and improved treatments. Here, we apply single cell RNA sequencing to study the heterogeneity of 40 individuals along the multiple myeloma progression spectrum, including 11 healthy controls, demonstrating high interindividual variability that can be explained by expression of known multiple myeloma drivers and additional putative factors. We identify extensive subclonal structures for 10 of 29 individuals with multiple myeloma. In asymptomatic individuals with early disease and in those with minimal residual disease post-treatment, we detect rare tumor plasma cells with molecular characteristics similar to those of active myeloma, with possible implications for personalized therapies. Single cell analysis of rare circulating tumor cells allows for accurate liquid biopsy and detection of malignant plasma cells, which reflect bone marrow disease. Our work establishes single cell RNA sequencing for dissecting blood malignancies and devising detailed molecular characterization of tumor cells in symptomatic and asymptomatic patients