A NOVEL FRAMEWORK FOR SIMULATING PARTICLE DEPOSITION WITH MOVING BEDFORMS

Previous modeling studies of hyporheic exchange induced by moving bedforms have used a moving reference frame, typically corresponding to an individual moving bedform. However, this approach is not suitable for simulating the exchange and accumulation of immobile fine particles beneath moving bedforms, which commonly occurs in sand-bed streams, as both moving and stationary features must be considered. Here we present a novel simulation framework that may represent arbitrarily shaped, generally aperiodic mobile bedforms within a stationary reference frame. We combine this approach with particle tracking to successfully reproduce observations of clay deposition in sand beds, and the resulting development of a low-conductivity layer near the scour zone. We find that increased bedform celerity and filtration both lead to a shallower depth of clay deposition and a more compact deposition layer. While increased filtration causes more clay to deposit, increased celerity reduces deposition by flattening hyporheic exchange flowpath

Diffuse large B cell lymphoma characteristics and outcomes during the COVID-19 pandemic in two tertiary centers - an Israeli/ Italian study

The COVID-19 pandemic posed a major challenge in cancer care worldwide which might have an impact on the management of diffuse large B-cell lymphoma (DLBCL). We conducted a retrospective study comparing characteristics, management, and outcomes of DLBCL patients diagnosed during the first year of the COVID-19 pandemic (1/3/2020-28/2/2021) to those diagnosed in the previous year (1/3/2019-28/2/2020) in two tertiary centers in Italy and Israel. 182 patients were diagnosed with DLBCL during the study period. More patients were diagnosed during the pandemic compared to the year before: 60 vs. 29 and 54 vs. 39 in Italy and in Israel, respectively. Trends towards older age and higher transformation rates were shown during the pandemic. The interval between the initiation of symptoms and diagnosis was longer during the pandemic. Five and four patients were diagnosed with COVID-19 during treatment in Italy and in Israel, respectively. there was no difference in dose density and intensity of treatment, before and during the pandemic. The median follow-up during and before the pandemic was 15.2 and 25.5 months, respectively. Progression-free survival (PFS) was slightly shorter during the pandemic compared to the year before (64.9% vs. 70.6%; p = 0.0499). In multivariate analysis, older age and transformed disease were independently related to PFS, while diagnosis of DLBCL during the pandemic was not. Despite the challenges caused by COVID-19 pandemic, the management of DLBCL patients remained unchanged including dose density and intensity. Nevertheless, a shorter PFS during the outbreak might be attributed to differences in patients' characteristics

Prediction of life-threatening and disabling bleeding in patients with AML receiving intensive induction chemotherapy

Bleeding in patients with acute myeloid leukemia (AML) receiving intensive induction chemotherapy is multifactorial and contributes to early death. We sought to define the incidence and risk factors of grade 4 bleeding to support strategies for risk mitigation. Bleeding events were retrospectively assessed between day-14 and day 160 of induction treatment according to the World Health Organization (WHO) bleeding assessment scale, which includes grade 4 bleeding as fatal, life-threatening, retinal with visual impairment, or involving the central nervous system. Predictors were considered pretreatment or prior to grade 4 bleeding. Using multivariable competing-risk regression analysis with grade 4 bleeding as the primary outcome, we identified risk factors in the development cohort (n=341), which were tested in an independent cohort (n=143). Grade 4 bleeding occurred in 5.9% and 9.8% of patients in the development and validation cohort, respectively. Risk factors that were independently associated with grade 4 bleeding included baseline platelet count #40x109/L compared with .40x109/L, and baseline international normalized ratio of prothrombin time (PT-INR) .1.5 or 1.3 . 1.5 compared with #1.3. These variables were allocated points, which allowed for stratification of patients with low- and high-risk for grade 4 bleeding. Cumulative incidence of grade 4 bleeding at day160 was significantly higher among patients with high- vs low-risk (development: 31±7% vs 2±1%; P<.001; validation: 25±9% vs 7±2%; P=.008). In both cohorts, high bleeding risk was associated with disseminated intravascular coagulation (DIC) and proliferative disease. We developed and validated a simple risk model for grade 4 bleeding, which enables the development of rational risk mitigation strategies to improve early mortality of intensive induction treatment