90 research outputs found
Position control of servo with discontinuouns rechangeable speed
Diplomová práci obsahuje simulaci náhrady spojitého řízení za nespojité. Cílem práce je řešení polohové regulace pístového servomotoru, který je ovládán přepouštěním tlakového oleje za pomoci několika elektromagneticky ovládaných rozvaděčů s clonami ve výstupních kanálech. Ověření činnosti regulované soustavy je provedeno pomocí simulace v prostředí Matlab/Simulink a prvků Matlab/Simulink, Matlab/Hydrosim. Požadavkem na vytvořený model je ověřit chování soustavy, aby po úpravách mohl být použitelný pro další rozvoj problematiky.Diploma thesis work includes simulation of compensation of control for discrete. The aim of the work is a solution positioning control of servomotor drive piston, which is controlled by pass of the pressure oil with the help of several electromagnetically controlled switchboards with the orifice in the output channels. The verification activities of the regulated system is done using simulation in Matlab/Simulink and Matlab/Simulink, Matlab/Hydrosim. The requirement on the created model is to verify the behavior of the system to be modified to be used for the further development of the issue
Successful Peripheral Blood Stem Cells Collection in Imatinib Pretreated and Nilotinib-Treated Chronic Myeloid Leukemia Patient
We report a case of a successful mobilization and harvest of the peripheral blood stem cells (PBSCs) in imatinib-pretreated and nilotinib treated 52-year-old woman diagnosed with Philadelphia chromosome-positive and BCR-ABL (b2a2) positive chronic phase CML in 2/2002. She failed interferon-alfa and imatinib treatment. She achieved her first complete molecular remission after 16 months of nilotinib treatment and later on was mobilized with filgrastim at a dose of 10 ug/kg/day applied subcutaneously once daily. The total number of 2.98 × 106 CD34+ cells/kg was harvested on the fourth day of the mobilization. The autologous graft of the stem cells was cryopreserved and tested for the residual disease: the FISH revealed negative results and the RT-PCR was positive (BCR-ABL/ABL ratio 0,0017 in RQ-PCR). To our knowledge, this is the first report of successful PBSC harvest in a patient significantly pretreated with imatinib and nilotinib
Challenges of Clinical Decision Support System Development
One of the high-growing areas in medicine is research and development of advanced IT technologies for clinical decision support. Clinical decision support system (CDSS) must be able to store the necessary clinical data and also to analyze this data, and process and interpret the results for a specialist. This article is focused on interdisciplinary research and development challenges in developing a complex information system for searching and selecting a suitable donor for bone marrow transplantation using an advanced DNA-based donor search model. The particular challenges are summarized and the approaches to tackle them are described
an ALWP-EBMT study
Background Allogeneic stem cell transplantation is the only curative option
for patients with acute myeloid leukemia (AML) experiencing relapse. Either
matched sibling donor (MSD) or unrelated donor (UD) is indicated. Methods We
analyzed 1554 adults with AML transplanted from MSD (n = 961) or UD (n = 593,
HLA-matched 10/10, n = 481; 9/10, n = 112). Compared to MSD, UD recipients
were older (49 vs 52 years, p = 0.001), transplanted more recently (2009 vs
2006, p = 0.001), and with a longer interval to transplant (10 vs 9 months, p
= 0.001). Conditioning regimen was more frequently myeloablative for patients
transplanted with a MSD (61 vs 46 %, p = 0.001). Median follow-up was 28
(range 3–157) months. Results Cumulative incidence (CI) of neutrophil
engraftment (p = 0.07), grades II–IV acute GVHD (p = 0.11), chronic GVHD (p =
0.9), and non-relapse mortality (NRM, p = 0.24) was not different according to
the type of donor. At 2 years, CI of relapse (relapse incidence (RI)) was 57
vs 49 % (p = 0.001). Leukemia-free survival (LFS) at 2 years was 21 vs 26 % (p
= 0.001), and overall survival (OS) was 26 vs 33 % (p = 0.004) for MSD vs UD,
respectively. Chronic GVHD as time-dependent variable was associated with
lower RI (HR 0.78, p = 0.05), higher NRM (HR 1.71, p = 0.001), and higher OS
(HR 0.69, p = 0.001). According to HLA match, RI was 57 vs 50 vs 45 %, (p =
0.001) NRM was 23 vs 23 vs 29 % (p = 0.26), and LFS at 2 years was 21 vs 27 vs
25 % (p = 0.003) for MSD, 10/10, and 9/10 UD, respectively. In multivariate
analysis adjusted for differences between the two groups, UD was associated
with lower RI (HR 0.76, p = 0.001) and higher LFS (HR 0.83, p = 0.001)
compared to MSD. Interval between diagnosis and transplant was the other
factor associated with better outcomes (RI (HR 0.62, p < 0.001) and LFS (HR
0.67, p < 0.001)). Conclusions Transplantation using UD was associated with
better LFS and lower RI compared to MSD for high-risk patients with AML
transplanted in first relapse
Measurable residual disease, FLT3-ITD mutation, and disease status have independent prognostic influence on outcome of allogeneic stem cell transplantation in NPM1-mutated acute myeloid leukemia
Nucleophosmin-1 (NPM1) mutations in acute myeloid leukemia (AML) confer a survival advantage in the absence of FLT3-internal tandem duplication (FLT3-ITD). Here, we investigated the main predictors of outcome after allogeneic hematopoietic stem cell transplantation (allo-HCT). We identified 1572 adult (age >= 18 year) patients with NPM1-mutated AML in first complete remission (CR1:78%) or second complete remission (CR2:22%) who were transplanted from matched sibling donors (30.8%) or unrelated donors (57.4%) between 2007 and 2019 at EBMT participating centers. Median follow-up for survivors was 23.7 months. FLT3-ITD was present in 69.3% of patients and 39.2% had detectable minimal/measurable residual disease (MRD) at transplant. In multivariate analysis, relapse incidence (RI) and leukemia-free survival (LFS) were negatively affected by concomitant FLT3-ITD mutation (HR 1.66 p = 0.0001, and HR 1.53, p < 0.0001, respectively), MRD positivity at transplant (HR 2.18, p < 10(-5) and HR 1.71, p < 10(-5), respectively), and transplant in CR2 (HR 1.36, p = 0.026, and HR 1.26, p = 0.033, respectively), but positively affected by Karnofsky score >= 90 (HR 0.74, p = 0.012, and HR 0.7, p = 0.0002, respectively). Overall survival (OS) was also negatively influenced by concomitant FLT3-ITD (HR 1.6, p = 0.0001), MRD positivity at transplant (HR 1.61, p < 10(-5)), and older age (HR 1.22 per 10 years, p < 0.0001), but positively affected by matched sibling donor (unrelated donor: HR 1.35, p = 0.012; haploidentical donor: HR 1.45, p = 0.037) and Karnofsky score >= 90 (HR 0.73, p = 0.004). These results highlight the independent and significant role of FLT3-ITD, MRD status, and disease status on posttransplant outcomes in patients with NPM1-mutated AML allowing physicians to identify patients at risk of relapse who may benefit from posttransplant prophylactic interventions.</p
Allogeneic Stem Cell Transplantation for Myelodysplastic Syndrome Patients with a 5q Deletion
The deletion (5q) karyotype (del [5q]) in patients with myelodysplastic syndrome (MDS) is the most common karyotypic abnormality in de novo MDS. An increased number of blasts and additional karyotypic abnormalities (del [al]+) are associated with a poor outcome. We analyzed the outcome of allogeneic hematopoietic cell transplants (HCT) in patients suffering from MDS with only del (5q) or del (5q)+. A total of 162 patients, of median age 54 years (range, 9 to 73), having MDS and del (5q) abnormalities received HCT from identical siblings (n = 87) or unrelated donors (n = 75). The cumulative incidence of nonrelapse mortality and relapse incidence at 4 years was 29% (95% CI, 22 to 36) and 46% (95% CI, 38 to 54), whereas the estimated 4 year survival, relapse-free and overall, was 25% (95% CI, 18 to 33) and 30% (95% CI, 23 to 38), respectively. In a multivariate analysis patients with del (5q) and a blast excess displayed poorer survival (hazard ratio, 2.38; 95% CI, 1.44 to 3.93; PPeer reviewe
Integrating biological HLA-DPB1 mismatch models to predict survival after unrelated hematopoietic cell transplantation
Ibrutinib as initial therapy for patients with chronic lymphocytic leukemia
Background: chronic lymphocytic leukemia (CLL) primarily affects older persons who often have coexisting conditions in addition to disease-related immunosuppression and myelosuppression. We conducted an international, open-label, randomized phase 3 trial to compare two oral agents, ibrutinib and chlorambucil, in previously untreated older patients with CLL or small lymphocytic lymphoma. Methods: we randomly assigned 269 previously untreated patients who were 65 years of age or older and had CLL or small lymphocytic lymphoma to receive ibrutinib or chlorambucil. The primary end point was progression-free survival as assessed by an independent review committee. Results: the median age of the patients was 73 years. During a median follow-up period of 18.4 months, ibrutinib resulted in significantly longer progression-free survival than did chlorambucil (median, not reached vs. 18.9 months), with a risk of progression or death that was 84% lower with ibrutinib than that with chlorambucil (hazard ratio, 0.16; P<0.001). Ibrutinib significantly prolonged overall survival; the estimated survival rate at 24 months was 98% with ibrutinib versus 85% with chlorambucil, with a relative risk of death that was 84% lower in the ibrutinib group than in the chlorambucil group (hazard ratio, 0.16; P=0.001). The overall response rate was higher with ibrutinib than with chlorambucil (86% vs. 35%, P<0.001). The rates of sustained increases from baseline values in the hemoglobin and platelet levels were higher with ibrutinib. Adverse events of any grade that occurred in at least 20% of the patients receiving ibrutinib included diarrhea, fatigue, cough, and nausea; adverse events occurring in at least 20% of those receiving chlorambucil included nausea, fatigue, neutropenia, anemia, and vomiting. In the ibrutinib group, four patients had a grade 3 hemorrhage and one had a grade 4 hemorrhage. A total of 87% of the patients in the ibrutinib group are continuing to take ibrutinib. Conclusions: ibrutinib was superior to chlorambucil in previously untreated patients with CLL or small lymphocytic lymphoma, as assessed by progression-free survival, overall survival, response rate, and improvement in hematologic variables. (Funded by Pharmacyclics and others; RESONATE-2 ClinicalTrials.gov number, NCT01722487.)
Readout of a quantum processor with high dynamic range Josephson parametric amplifiers
We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in
which the active nonlinear element is implemented using an array of rf-SQUIDs.
The device is matched to the 50 environment with a Klopfenstein-taper
impedance transformer and achieves a bandwidth of 250-300 MHz, with input
saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor
was used to benchmark these devices, providing a calibration for readout power,
an estimate of amplifier added noise, and a platform for comparison against
standard impedance matched parametric amplifiers with a single dc-SQUID. We
find that the high power rf-SQUID array design has no adverse effect on system
noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on
amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with
this design show no degradation in readout fidelity due to gain compression,
which can occur in multi-tone multiplexed readout with traditional JPAs.Comment: 9 pages, 8 figure
Measurement-Induced State Transitions in a Superconducting Qubit: Within the Rotating Wave Approximation
Superconducting qubits typically use a dispersive readout scheme, where a
resonator is coupled to a qubit such that its frequency is qubit-state
dependent. Measurement is performed by driving the resonator, where the
transmitted resonator field yields information about the resonator frequency
and thus the qubit state. Ideally, we could use arbitrarily strong resonator
drives to achieve a target signal-to-noise ratio in the shortest possible time.
However, experiments have shown that when the average resonator photon number
exceeds a certain threshold, the qubit is excited out of its computational
subspace, which we refer to as a measurement-induced state transition. These
transitions degrade readout fidelity, and constitute leakage which precludes
further operation of the qubit in, for example, error correction. Here we study
these transitions using a transmon qubit by experimentally measuring their
dependence on qubit frequency, average photon number, and qubit state, in the
regime where the resonator frequency is lower than the qubit frequency. We
observe signatures of resonant transitions between levels in the coupled
qubit-resonator system that exhibit noisy behavior when measured repeatedly in
time. We provide a semi-classical model of these transitions based on the
rotating wave approximation and use it to predict the onset of state
transitions in our experiments. Our results suggest the transmon is excited to
levels near the top of its cosine potential following a state transition, where
the charge dispersion of higher transmon levels explains the observed noisy
behavior of state transitions. Moreover, occupation in these higher energy
levels poses a major challenge for fast qubit reset
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