7 research outputs found
Structural dynamics of first-order phase transition in giant magnetocaloric La(Fe,Si)13: The free energy landscape
Maximizing the performance of magnetic refrigerators and thermomagnetic energy harvesters is imperative for their successful implementation and can be done by maximizing their operation frequency. One of the features delimiting the frequency and efficiency of such devices is the phase transition kinetics of their magnetocaloric/thermomagnetic active material. While previous studies have described the magnetic component governing the kinetics of the magnetovolume phase transition in La(Fe,Si)13 giant magnetocaloric materials, a comprehensive description of its structural component has yet to be explored. In this study, in situ synchrotron X-ray diffraction is employed to describe the structural changes upon magnetic field application/removal. Long magnetic field dependent relaxation times up to a few hundred seconds are observed after the driving field is paused. The phase transition is found to be highly asymmetric upon magnetic field cycling due to the different Gibbs energy landscapes and the absence of an energy barrier upon field removal. An exponential relationship is found between the energy barriers and the relaxation times, suggesting the process is governed by a non-thermal activation over an energy barrier process. Such fundamental knowledge on first-order phase transition kinetics suggests pathways for materials optimization and smarter design of magnetic field cycling in real-life devices
Molecular and functional profiling identifies therapeutically targetable vulnerabilities in plasmablastic lymphoma
Plasmablastic lymphoma (PBL) represents a rare and aggressive lymphoma subtype frequently associated with immunosuppression. Clinically, patients with PBL are characterized by poor outcome. The current understanding of the molecular pathogenesis is limited. A hallmark of PBL represents its plasmacytic differentiation with loss of B-cell markers and, in 60% of cases, its association with Epstein-Barr virus (EBV). Roughly 50% of PBLs harbor a MYC translocation. Here, we provide a comprehensive integrated genomic analysis using whole exome sequencing (WES) and genome-wide copy number determination in a large cohort of 96 primary PBL samples. We identify alterations activating the RAS-RAF, JAK-STAT, and NOTCH pathways as well as frequent high-level amplifications in MCL1 and IRF4. The functional impact of these alterations is assessed using an unbiased shRNA screen in a PBL model. These analyses identify the IRF4 and JAK-STAT pathways as promising molecular targets to improve outcome of PBL patients
Potential human transmission of amyloid β pathology: surveillance and risks
Studies in experimental animals show transmissibility of amyloidogenic proteins associated with prion diseases, Alzheimer's disease, Parkinson's disease, and other neurodegenerative diseases. Although these data raise potential concerns for public health, convincing evidence for human iatrogenic transmission only exists for prions and amyloid β after systemic injections of contaminated growth hormone extracts or dura mater grafts derived from cadavers. Even though these procedures are now obsolete, some reports raise the possibility of iatrogenic transmission of amyloid β through putatively contaminated neurosurgical equipment. Iatrogenic transmission of amyloid β might lead to amyloid deposition in the brain parenchyma and blood vessel walls, potentially resulting in cerebral amyloid angiopathy after several decades. Cerebral amyloid angiopathy can cause life-threatening brain haemorrhages; yet, there is no proof that the transmission of amyloid β can also lead to Alzheimer's dementia. Large, long-term epidemiological studies and sensitive, cost-efficient tools to detect amyloid are needed to better understand any potential routes of amyloid β transmission and to clarify whether other similar proteopathic seeds, such as tau or α-synuclein, can also be transferred iatrogenically
Structural dynamics of first-order phase transition in giant magnetocaloric La(Fe,Si)13: the free energy landscape
Maximizing the performance of magnetic refrigerators and thermomagnetic energy harvesters is imperative for their successful implementation and can be done by maximizing their operation frequency. One of the features delimiting the frequency and efficiency of such devices is the phase transition kinetics of their magnetocaloric/thermomagnetic active material. While previous studies have described the magnetic component governing the kinetics of the magnetovolume phase transition in La(Fe,Si)13 giant magnetocaloric materials, a comprehensive description of its structural component has yet to be explored. In this study, in situ synchrotron X-ray diffraction is employed to describe the structural changes upon magnetic field application/removal. Long magnetic field dependent relaxation times up to a few hundred seconds are observed after the driving field is paused. The phase transition is found to be highly asymmetric upon magnetic field cycling due to the different Gibbs energy landscapes and the absence of an energy barrier upon field removal. An exponential relationship is found between the energy barriers and the relaxation times, suggesting the process is governed by a non-thermal activation over an energy barrier process. Such fundamental knowledge on first-order phase transition kinetics suggests pathways for materials optimization and smarter design of magnetic field cycling in real-life devices
Rituximab plus high-dose chemotherapy (MegaCHOEP) or conventional chemotherapy (CHOEP-14) in young, high-risk patients with aggressive B-cell lymphoma: 10-year follow-up of a randomised, open-label, phase 3 trial
Findings Between March 3, 2003, and April 7, 2009, 275 patients were randomly assigned to R-CHOEP-14 (n=136) or R-MegaCHOEP (n=139). 130 patients in the R-CHOEP-14 group and 132 patients in the R-MegaCHOEP group were included in the intention-to-treat population. After a median follow-up of 9?3 years (IQR 5?1?11?1), 10-year event-free survival was 51% (95% CI 42?61) in the R-MegaCHOEP group and 57% (47?67) in the R-CHOEP-14 group (adjusted hazard ratio [HR] 1?3 [95% CI 0?9?1?8], p=0?23). 10-year progression-free survival was 59% (50?68) in the R-MegaCHOEP group and 60% (51?70) in the R-CHOEP-14 group (adjusted HR 1?1 [0?7?1?7], p=0?64). 10-year overall survival was 66% (57?76) in the R-MegaCHOEP group and 72% (63?81) in the R-CHOEP-14 group (adjusted HR 1?3 [0?8?2?1], p=0?26). Relapse occurred in 30 (16% [95% CI 11?22]) of 190 patients who had complete remission or unconfirmed complete remission; 17 (17%) of 100 patients in the R-CHOEP-14 group and 13 (14%) of 90 patients in the R-MegaCHOEP group. Seven (23%) of 30 patients had low-grade histology at relapse and had better outcomes compared with patients who relapsed with aggressive histologies. Lymphoma affected the CNS in 18 (28%) of 64 patients with treatment failure. 22 secondary malignancies were reported in the intention-to-treat population; in 12 (9%) of 127 patients in the R-CHOEP-14 group and ten (8%) of 126 patients in the R-MegaCHOEP group. Background R-MegaCHOEP was the first phase 3 study comparing high-dose chemotherapy plus rituximab followed by autologous haematopoietic stem-cell transplantation (HSCT) with conventional chemotherapy plus rituximab in first-line therapy for patients aged 60 years or younger with high-risk aggressive B-cell lymphoma. Little is known about the long-term outcomes of these patients. We aimed to evaluate the long-term efficacy and safety of conventional chemotherapy versus high-dose chemotherapy after 10 years of follow-up in the R-MegaCHOEP trial. Methods In this open-label, randomised, phase 3 trial done across 61 centres in Germany, patients aged 18-60 years with newly diagnosed, high-risk (age-adjusted International Prognostic Index [IPI] 2 or 3) aggressive B-cell lymphoma were randomly assigned (1:1, using Pocock minimisation) to eight cycles of conventional chemotherapy (cyclosphosphamide, doxorubicin, vincristine, etoposide, and prednisolone) plus rituximab (R-CHOEP-14) or four cycles of high-dose chemotherapy plus rituximab followed by autologous HSCT (R-MegaCHOEP). The trial was unmasked. Patients were stratified by age-adjusted IPI factors, presence of bulky disease (tumour mass >= 7 & middot;5 cm diameter), and treatment centre. The primary endpoint was event-free survival, analysed here 10 years after randomisation. 10-year overall survival, progression-free survival, conditional survival, relapse patterns, secondary malignancies, and molecular characteristics were also analysed. All analyses were done on the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT00129090. Findings Between March 3, 2003, and April 7, 2009, 275 patients were randomly assigned to R-CHOEP-14 (n=136) or R-MegaCHOEP (n=139). 130 patients in the R-CHOEP-14 group and 132 patients in the R-MegaCHOEP group were included in the intention-to-treat population. After a median follow-up of 9 & middot;3 years (IQR 5 & middot;1-11 & middot;1), 10-year event-free survival was 51% (95% CI 42-61) in the R-MegaCHOEP group and 57% (47-67) in the R-CHOEP-14 group (adjusted hazard ratio [HR] 1 & middot;3 [95% CI 0 & middot;9-1 & middot;8], p=0 & middot;23). 10-year progression-free survival was 59% (50-68) in the R-MegaCHOEP group and 60% (51-70) in the R-CHOEP-14 group (adjusted HR 1 & middot;1 [0 & middot;7-1 & middot;7], p=0 & middot;64). 10-year overall survival was 66% (57-76) in the R-MegaCHOEP group and 72% (63-81) in the R-CHOEP-14 group (adjusted HR 1 & middot;3 [0 & middot;8-2 & middot;1], p=0 & middot;26). Relapse occurred in 30 (16% [95% CI 11-22]) of 190 patients who had complete remission or unconfirmed complete remission; 17 (17%) of 100 patients in the R-CHOEP-14 group and 13 (14%) of 90 patients in the R-MegaCHOEP group. Seven (23%) of 30 patients had low-grade histology at relapse and had better outcomes compared with patients who relapsed with aggressive histologies. Lymphoma affected the CNS in 18 (28%) of 64 patients with treatment failure. 22 secondary malignancies were reported in the intention-to-treat population; in 12 (9%) of 127 patients in the R-CHOEP-14 group and ten (8%) of 126 patients in the R-MegaCHOEP group. Interpretation Event-free survival and overall survival were similar between groups after 10 years of follow-up; outcomes were not improved in the R-MegaCHOEP group by high-dose chemotherapy and autologous HSCT. Patients who relapsed with aggressive histology showed a high incidence of CNS involvement and poor prognosis. For these patients, novel therapies are greatly warranted. Funding Deutsche Krebshilfe (German Cancer Aid). Copyright (c) 2021 Elsevier Ltd. All rights reserved. Methods In this open-label, randomised, phase 3 trial done across 61 centres in Germany, patients aged 18?60 years with newly diagnosed, high-risk (age-adjusted International Prognostic Index [IPI] 2 or 3) aggressive B-cell lymphoma were randomly assigned (1:1, using Pocock minimisation) to eight cycles of conventional chemotherapy (cyclosphosphamide, doxorubicin, vincristine, etoposide, and prednisolone) plus rituximab (R-CHOEP-14) or four cycles of high-dose chemotherapy plus rituximab followed by autologous HSCT (R-MegaCHOEP). The trial was unmasked. Patients were stratified by age-adjusted IPI factors, presence of bulky disease (tumour mass ?7?5 cm diameter), and treatment centre. The primary endpoint was event-free survival, analysed here 10 years after randomisation. 10-year overall survival, progression-free survival, conditional survival, relapse patterns, secondary malignancies, and molecular characteristics were also analysed. All analyses were done on the intention-to-trea