323 research outputs found

    In situ observation of compressive deformation of an interconnected network of zinc oxide tetrapods

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    Zinc oxide tetrapods have remarkable functional and mechanical properties with potential applications in different fields including nanoelectronic and optoelectronic sensing, functional composites and coatings, as well as energy harvesting and storage. Based on the 3D shape of these microparticles, they can be assembled into highly porous (up to 98%) macroscopic ceramic framework structures that can be utilized as a versatile template for the fabrication of other multi-scaled foam-like materials. Here we investigated the three-dimensional structure of low density interconnected zinc oxide tetrapod networks by high resolution X-ray computed tomography. In situ observations during mechanical loading show inhomogeneous development of anelastic strain (damage) during compression, and homogeneous elastic recovery on unloading. Individual tetrapods are observed to deform by arm rotation to accommodate strain

    High intensity neutrino oscillation facilities in Europe

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    The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fréjus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of μ+ and μ− beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular He6 and Ne18, also stored in a ring. The far detector is also the MEMPHYS detector in the Fréjus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive

    Impact of conditioning regimen on outcomes for children with acute myeloid leukemia undergoing transplantation in first complete remission. An analysis on behalf of the Pediatric Disease Working Party of the European Group for Blood and Marrow Transplantation

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    Hematopoietic stem cell transplantation (HSCT) represents the cornerstone of treatment in pediatric high-risk and relapsed acute myeloid leukemia (AML). The aim of the present study was to compare outcomes of pediatric patients with AML undergoing HSCT using 3 different conditioning regimens: total body irradiation (TBI) and cyclophosphamide (Cy); busulfan (Bu) and Cy; or Bu, Cy, and melphalan (Mel). In this retrospective study, registry data for patients > 2 and <18 years age undergoing matched allogeneic HSCT for AML in first complete remission (CR1) in 204 European Group for Blood and Marrow Transplantation centers between 2000 and 2010 were analyzed. Data were available for 631 patients; 458 patients received stem cells from a matched sibling donor and 173 from a matched unrelated donor. For 440 patients, bone marrow was used as stem cell source, and 191 patients received peripheral blood stem cells. One hundred nine patients received TBICy, 389 received BuCy, and 133 received BuCyMel as their preparatory regimen. Median follow-up was 55 months. Patients receiving BuCyMel showed a lower incidence of relapse at 5 years (14.7% versus 31.5% in BuCy versus 30% in TBICy, P < .01) and higher overall survival (OS) (76.6% versus 64% versus 64.5%, P = .04) and leukemia-free survival (LFS) (74.5% versus 58% versus 61.9%, P < .01), with a comparable nonrelapse mortality (NRM) (10.8% versus 10.5% versus 8.1%, P = .79). Acute graft-versus-host disease (GVHD) grades III and IV but not chronic GVHD, was higher in patients receiving BuCyMel. Older age at HSCT had an adverse impact on NRM and the use of peripheral blood as stem cell source was associated with increased chronic GVHD and NRM as well as lower LFS and OS. Among pediatric patients receiving HSCT for AML in CR1, the use of BuCyMel conditioning proved superior to TBICy and BuCy in reducing relapse and improving LFS

    Role of Mitochondrial Complex IV in Age-Dependent Obesity

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    Aging is associated with progressive white adipose tissue (WAT) enlargement initiated early in life, but the molecular mechanisms involved remain unknown. Here we show that mitochondrial complex IV (CIV) activity and assembly are already repressed in white adipocytes of middle-aged mice and involve a HIF1A-dependent decline of essential CIV components such as COX5B. At the molecular level, HIF1A binds to the Cox5b proximal promoter and represses its expression. Silencing of Cox5b decreased fatty acid oxidation and promoted intracellular lipid accumulation. Moreover, local in vivo Cox5b silencing in WAT of young mice increased the size of adipocytes, whereas restoration of COX5B expression in aging mice counteracted adipocyte enlargement. An age-dependent reduction in COX5B gene expression was also found in human visceral adipose tissue. Collectively, our findings establish a pivotal role for CIV dysfunction in progressive white adipocyte enlargement during aging, which can be restored to alleviate age-dependent WAT expansion

    Proposed therapeutic range of treosulfan in reduced toxicity pediatric allogeneic hematopoietic stem cell transplant conditioning: results from a prospective trial

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    Treosulfan is given off‐label in pediatric allogeneic hematopoietic stem cell transplant. This study investigated treosulfan's pharmacokinetics (PKs), efficacy, and safety in a prospective trial. Pediatric patients (n = 87) receiving treosulfan‐fludarabine conditioning were followed for at least 1 year posttransplant. PKs were described with a two‐compartment model. During follow‐up, 11 of 87 patients died and 12 of 87 patients had low engraftment (≤ 20% myeloid chimerism). For each increase in treosulfan area under the curve from zero to infinity (AUC(0‐∞)) of 1,000 mg hour/L the hazard ratio (95% confidence interval) for mortality increase was 1.46 (1.23–1.74), and the hazard ratio for low engraftment was 0.61 (0.36–1.04). A cumulative AUC(0‐∞) of 4,800 mg hour/L maximized the probability of success (> 20% engraftment and no mortality) at 82%. Probability of success with AUC(0‐∞) between 80% and 125% of this target were 78% and 79%. Measuring PK at the first dose and individualizing the third dose may be required in nonmalignant disease

    Impact of in vivo lymphodepletion on outcome in children with nonmalignant disorders receiving peripheral blood stem cell transplantation

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    Peripheral blood stem cell transplantation (PBSCT) with in vivo lymphodepletion can provide faster neutrophil recovery with limited risk of severe graft-versus-host disease (GVHD) in children with nonmalignant disorders (NMDs). We aimed to provide an historical comparison of these 2 strategies regarding the prevalence of GVHD, viral reactivation, timing of immune reconstitution, and final outcomes. Data on 98 children undergoing PBSCT were collected from 5 European pediatric transplantation centers. Only patients with NMDs receiving treosulfan or myeloablative busulfan conditioning and 9-10/10 HLA-matched transplant were included. The patients were divided into 2 groups according to in vivo lymphodepletion with antithymocyte globulin (ATG) or with alemtuzumab. We compared rates of acute and chronic GVHD; Epstein-Barr virus, cytomegalovirus, and adenovirus reactivation; chimerism; lymphocyte recovery; overall survival (OS) and event-free survival (EFS) between the 2 groups. The rate of severe acute GVHD (grade III-IV) was significantly higher in patients receiving ATG (26% vs 10% in alemtuzumab recipients; P <.05), whereas viral reactivations occurred with a similar rate in the 2 groups (alemtuzumab, 56%; ATG, 57%). Alemtuzumab was the major risk factor for delayed T cell immune reconstitution in the first 3 months after transplantation (odds ratio [OR], 6.0; 95% confidence interval [CI], 1.8 to 19; P <.005). Extended chronic GVHD, ADV reactivation, slower CD3(+) cell recovery, and HLA-mismatch reduced the probability of survival. Infections were the main cause of mortality in our cohort, and delayed T cell recovery was significantly associated with mortality in multivariate analysis (OR, 12; 95% CI, 1.2 to 114; P <.05). Ultimately, no differences in OS and EFS survival were seen between the ATG and alemtuzumab groups. ATG and alemtuzumab showed similar impacts on outcomes of children undergoing PBSCT for NMDs. The 2 strategies of in vivo lymphodepletion showed specific drawbacks that were counterbalanced by benefits that ultimately led to a comparable survival rate. A patient-centered lymphodepletion strategy can be advised in children undergoing PBSCT for NMDs, by favoring T cell recovery in the presence of invasive infection or GVHD prevention in high-risk mismatched donor transplantation. (C) 2021 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.Transplantation and immunomodulatio
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