Tensile strain of germanium micro-disks on freestanding SiO2 beams

Tensile strain is crucial to expect the direct recombination in germanium (Ge), towards monolithic light sources on silicon (Si). Freestanding beams of Ge are known to produce strong tensile strain, however, it is not trivial to construct a cavity in a freestanding structure. Here, we fabricated Ge micro-disks on freestanding oxide beams, and observed Whispering-Gallery-Modes (WGM) by photoluminescence. The tensile strain was larger in shorter beams, which is consistent with simulations

Overcoming minimal residual disease using intensified conditioning with medium-dose etoposide, cyclophosphamide and total body irradiation in allogeneic stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia in adults

BACKGROUND AIMS: An intensified conditioning regimen incorporating medium-dose etoposide (VP16) is an option for patients with acute lymphoblastic leukemia (ALL). However, the prognostic impacts of the addition of VP16 to cyclophosphamide (CY) and total body irradiation (TBI) in patients with Philadelphia chromosome-positive (Ph+) ALL with regard to minimal residual disease (MRD) status have not been elucidated. METHODS: The authors retrospectively compared the outcomes of patients with Ph+ ALL who underwent allogeneic transplantation following VP16/CY/TBI (n = 101) and CY/TBI (n = 563). RESULTS: At 4 years, the VP16/CY/TBI group exhibited significantly better disease-free survival (DFS) (72.6% versus 61.7%, P = 0.027) and relapse rate (11.5% versus 21.1%, P = 0.020) and similar non-relapse mortality (16.0% versus 17.2%, P = 0.70). In subgroup analyses, the beneficial effects of the addition of VP16 on DFS were more evident in patients with positive MRD status (71.2% versus 48.4% at 4 years, P = 0.022) than those with negative MRD status (72.8% versus 66.7% at 4 years, P = 0.24). Although MRD positivity was significantly associated with worse DFS in patients who received CY/TBI (48.4% versus 66.7%, P < 0.001), this was not the case in those who received VP16/CY/TBI (71.2% versus 72.8%, P = 0.86). CONCLUSIONS: This study demonstrated the benefits of the addition of VP16 in Ph+ ALL patients, especially those with positive MRD status. VP16/CY/TBI could be a potential strategy to overcome the survival risk of MRD positivity

Adult patients with Ph+ ALL benefit from conditioning regimen of medium‐dose VP16 plus CY/TBI

The medium-dose etoposide (VP16) added on cyclophosphamide (CY)/total body irradiation (TBI) is one of the intensified myeloablative conditioning regimens used in allogenic hematopoietic stem cell transplantation (allo-HSCT) for acute lymphoblastic leukemia (ALL). However, the patient subgroups who can actually benefit from VP16/CY/TBI compared to CY/TBI have not been precisely defined. Therefore, we conducted a multi-center retrospective study using the Japanese nationwide registry database to elucidate the efficacy of VP16/CY/TBI on post-transplant prognosis. Biological and clinical distinct subtypes (i.e., Philadelphia chromosome-positive (Ph+) and -negative (Ph−) ALL) were evaluated separately, which included 820 Ph+ and 1463 patients with Ph− ALL, respectively. Compared with the CY/TBI group, the VP16/CY/TBI group showed superior progression-free survival (PFS) in patients with Ph+ ALL (65% vs. 57% at 3 years after HSCT; adjusted hazard ratio (HR), 0.73; 95% confidence interval (CI), 0.55–0.98; p = 0.03), along with significantly reduced incidence of relapse (adjusted HR, 0.58; 95% CI, 0.37–0.90; p = 0.02) without the increase of non-relapse mortality (NRM). By contrast, in patients with Ph− ALL, VP16/CY/TBI did not improve PFS nor incidence of relapse; addition of VP16 reduced relapse (HR, 0.65; p = 0.06) in patients with Ph− ALL transplanted at CR1, while improved PFS was not observed (HR, 0.90; p = 0.52) due to increased NRM. This study demonstrated that VP16/CY/TBI is a more effective and well-tolerated regimen in comparison with CY/TBI in patients with myeloablative allo-HSCT for adult Ph+ ALL. Our findings can provide a novel algorithm for conditioning regimen selection in patients with adult ALL

Spin-on doping of germanium-on-insulator wafers for monolithic light sources on silicon

High electron doping of germanium (Ge) is considered to be an important process to convert Ge into an optical gain material and realize a monolithic light source integrated on a silicon chip. Spin-on doping is a method that offers the potential to achieve high doping concentrations without affecting crystalline qualities over other methods such as ion implantation and in-situ doping during material growth. However, a standard spin-on doping recipe satisfying these requirements is not yet available. In this paper we examine spin-on doping of Ge-on-insulator (GOI) wafers. Several issues were identified during the spin-on doping process and specifically the adhesion between Ge and the oxide, surface oxidation during activation, and the stress created in the layers due to annealing. In order to mitigate these problems, Ge disks were first patterned by dry etching followed by spin-on doping. Even by using this method to reduce the stress, local peeling of Ge could still be identified by optical microscope imaging. Nevertheless, most of the Ge disks remained after the removal of the glass. According to the Raman data, we could not identify broadening of the lineshape which shows a good crystalline quality, while the stress is slightly relaxed. We also determined the linear increase of the photoluminescence intensity by increasing the optical pumping power for the doped sample, which implies a direct population and recombination at the gamma valley

Fabrication of Ge micro-disks on free-standing SiO2 beams for monolithic light emission

Realizing a germanium (Ge)-based monolithic light source requires n-type doping with high activation levels, tensilestrain, and an optical cavity. Here, we demonstrate the application of spin-on doping technique, and the use of free-standing structures to induce tensile strain on Ge micro-disks, which act as a simple micro-cavit

Raw data for &#39;Tensile Strain Engineering of Germanium Micro-Disks on Free-Standing SiO2 Beams&#39;.

This dataset contains the raw data for &#39;Tensile Strain Engineering of Germanium Micro-Disks on Free-Standing SiO2 Beams&#39;. Summary of this dataset in the form of figures were published by the Japanese Journal of Applied Physics (JJAP), Special Issues of the International Conference on Solid-State Devices and Materials (SSDM) 2015, Sapporo, Japan. Copyright 2016 The Japan Society of Applied Physics.</span

Residual disease is a strong prognostic marker in patients with acute lymphoblastic leukaemia with chemotherapy‐refractory or relapsed disease prior to allogeneic stem cell transplantation

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is one of the curative treatment options for acute lymphoblastic leukaemia (ALL). However, the outcomes in patients transplanted without complete remission (non-CR) have not yet been fully reported, and detailed analyses are required to identify subgroups in which optimal prognosis is expected and to optimize pre-transplant therapeutic strategies. Hence, we performed a multicentred retrospective cohort study including a total of 663 adult ALL patients transplanted at non-CR status; the median bone marrow (BM) blast counts at HSCT was 13·2%, and 203 patients (30·6%) were treated at primary induction failure status. The overall survival (OS) was 31·1% at two years, and the multivariate analyses identified five prognostic risk factors, including older age (≥50 years), increased BM blasts (≥10%), poor performance status, high haematopoietic cell transplantation (HCT)-comorbidity index, and relapsed disease status, among which BM blast was the most significantly related. A predictive scoring system composed of these risk factors clearly stratified OS (15·6-59·5% at two years). In conclusion, this is the first large-scale study to analyze the correlation of patient characteristics with post-transplant prognosis in ALL transplanted at non-CR status. The importance of blast control before HSCT should be focused on for better patient prognosis

Raw data for &#39;Fabrication of Ge micro-disks on free-standing SiO2 beams for monolithic light emission&#39;.

This dataset contains the raw data for the fabrication of Ge micro-disks on free-standing SiO2 beams for monolithic light emission. Summary of this dataset in the form of figures were published by IEEE, proceedings of the IEEE NANO 2015 conference, Rome, Italy. 978-1-4673-8156-7/15/$31.00 &copy; 2015 IEEE</span

Raw data for &#39;Spin-on doping of germanium-on-insulator wafers for monolithic light sources on silicon&#39;. Published by Japanese Journal of Applied Physics (JJAP). Copyright 2015 The Japan Society of Applied Physics.

This dataset contains the raw data for spin-on doping experiments of Ge-on-insulator wafers for light emission purposes. Summary of this dataset in the form of figures were published Japanese Journal of Applied Physics (JJAP). Copyright 2015 The Japan Society of Applied Physics. Citation: Abdelrahman Zaher Al-Attili, Satoshi Kako, Muhammad K. Husain, Frederic Y. Gardes, Hideo Arimoto, Naoki Higashitarumizu, Satoshi Iwamoto, Yasuhiko Arakawa, Yasuhiko Ishikawa, and Shinichi Saito. &quot;Spin-on doping of germanium-on-insulator wafers for monolithic light sources on silicon.&quot; Japanese Journal of Applied Physics, vol. 54, no. 5, p. 052101, 2015. Funded by Funding Program for World-Leading Innovation R&amp;D on Science and Technology (FIRST Program). Japan Society for the Promotion of Science The Project for Developing Innovation Systems, and Kakenhi (216860312). Ministry of Education, Culture, Sports, Science, and Technology, Japan (MEXT)</span