Solids containing spherical nano-inclusions with interface stresses: Effective properties and thermal–mechanical connections

AbstractThis work examines the overall thermoelastic behavior of solids containing spherical inclusions with surface effects. Elastic response is evaluated as a superposition of separate solutions for isotropic and deviatoric overall loads. Using a variational approach, we construct the Euler–Lagrange equation together with the natural transition (jump) conditions at the interface. The overall bulk modulus is derived in a simple form, based on the construction of neutral composite sphere. The transverse shear modulus estimate is derived using the generalized self-consistent method. Further, we show that there exists an exact connection between effective thermal expansion and bulk modulus. This connection is valid not only for a composite sphere, but also for a matrix-based composite reinforced by many randomly distributed spheres of the same size, and can be viewed as an analog of Levin’s formula for composites with surface effects

Disease burden and conditioning regimens in ASCT1221, a randomized phase II trial in children with juvenile myelomonocytic leukemia: A Children's Oncology Group study

Background: Most patients with juvenile myelomonocytic leukemia (JMML) are curable only with allogeneic hematopoietic cell transplantation (HCT). However, the current standard conditioning regimen, busulfan-cyclophosphamide-melphalan (Bu-Cy-Mel), may be associated with higher risks of morbidity and mortality. ASCT1221 was designed to test whether the potentially less-toxic myeloablative conditioning regimen containing busulfan-fludarabine (Bu-Flu) would be associated with equivalent outcomes. Procedure: Twenty-seven patients were enrolled on ASCT1221 from 2013 to 2015. Pre- and post-HCT (starting Day +30) mutant allele burden was measured in all and pre-HCT therapy was administered according to physician discretion. Results: Fifteen patients were randomized (six to Bu-Cy-Mel and nine to Bu-Flu) after meeting diagnostic criteria for JMML. Pre-HCT low-dose chemotherapy did not appear to reduce pre-HCT disease burden. Two patients, however, received aggressive chemotherapy pre-HCT and achieved low disease-burden state; both are long-term survivors. All four patients with detectable mutant allele burden at Day +30 post-HCT eventually progressed compared to two of nine patients with unmeasurable allele burden (P = 0.04). The 18-month event-free survival of the entire cohort was 47% (95% CI, 21–69%), and was 83% (95% CI, 27–97%) and 22% (95% CI, 03–51%) for Bu-Cy-Mel and Bu-Flu, respectively (P = 0.04). ASCT1221 was terminated early due to concerns that the Bu-Flu arm had inferior outcomes. Conclusions: The regimen of Bu-Flu is inadequate to provide disease control in patients with JMML who present to HCT with large burdens of disease. Advances in molecular testing may allow better characterization of biologic risk, pre-HCT responses to chemotherapy, and post-HCT management

Hematopoietic stem cell transplantation for CD40 ligand deficiency: results from an EBMT/ESID-IEWP-SCETIDE-PIDTC Study

BACKGROUND: CD40 ligand (CD40L) deficiency, an X-linked primary immunodeficiency, causes recurrent sinopulmonary, Pneumocystis and Cryptosporidium infections. Long-term survival with supportive therapy is poor. Currently, the only curative treatment is hematopoietic stem cell transplantation (HSCT). OBJECTIVE: We performed an international collaborative study to improve patients' management, aiming to individualize risk factors and determine optimal HSCT characteristics. METHODS: We retrospectively collected data on 130 patients who underwent HSCT for CD40L deficiency between 1993-2015. We analyzed outcome and variables relevance with respect to survival and cure. RESULTS: Overall survival (OS), event-free survival (EFS) and disease-free survival (DFS) were 78.2%, 58.1% and 72.3% 5 years post-HSCT. Results were better in transplants performed ≥2000 and in children <10 years old at HSCT. Pre-existing organ damage negatively influenced outcome. Sclerosing cholangitis was the most important risk factor. After 2000, superior OS was achieved with matched donors. Use of myeloablative regimens and HSCT ≤2 years from diagnosis associated with higher OS and DFS. EFS was best with matched sibling donors, myeloablative conditioning (MAC) and bone marrow-derived stem cells. Most rejections occurred after reduced intensity or non-myeloablative conditioning, which associated with poor donor cell engraftment. Mortality occurred mainly early after HSCT, predominantly from infections. Among survivors who ceased immunoglobulin replacement, T-lymphocyte chimerism was ≥50% donor in 85.2%. CONCLUSION: HSCT is curative in CD40L deficiency, with improved outcome if performed before organ damage development. MAC is associated with better OS, EFS and DFS. Prospective studies are required to compare risks of HSCT with those of life-long supportive therapy