212 research outputs found
Maximum Classifier Discrepancy for Unsupervised Domain Adaptation
In this work, we present a method for unsupervised domain adaptation. Many
adversarial learning methods train domain classifier networks to distinguish
the features as either a source or target and train a feature generator network
to mimic the discriminator. Two problems exist with these methods. First, the
domain classifier only tries to distinguish the features as a source or target
and thus does not consider task-specific decision boundaries between classes.
Therefore, a trained generator can generate ambiguous features near class
boundaries. Second, these methods aim to completely match the feature
distributions between different domains, which is difficult because of each
domain's characteristics.
To solve these problems, we introduce a new approach that attempts to align
distributions of source and target by utilizing the task-specific decision
boundaries. We propose to maximize the discrepancy between two classifiers'
outputs to detect target samples that are far from the support of the source. A
feature generator learns to generate target features near the support to
minimize the discrepancy. Our method outperforms other methods on several
datasets of image classification and semantic segmentation. The codes are
available at \url{https://github.com/mil-tokyo/MCD_DA}Comment: Accepted to CVPR2018 Oral, Code is available at
https://github.com/mil-tokyo/MCD_D
Kinetics Study of Adsorption Behaviors of Trivalent Metal Ions onto Chelating Resin: Comparison between Scandium(III) and Other Metal Ions
Scandium (Sc) lacks commercially viable independent deposits and is mainly recovered as a by-product of the smelting of other ores. In the process of recovering nickel from laterite ores, Sc is recovered from leaching solutions. The recovery of Sc requires its efficient separation and purification from other impurities. This study proposes a process for the selective separation and recovery of Sc from other trivalent cations in sulfuric acid solutions using an iminodiacetic acid chelating resin, Diaion™ CR11. The adsorption behaviors of trivalent ions Sc(III), Cr(III), Al(III), and Fe(III) onto CR11 in single- and multiple-metal systems were investigated to determine the appropriate Sc separation conditions. In systems containing single metal ions, pseudo-first-order and pseudo-second-order kinetic models were used to fit the data. Linear and nonlinear methods were used for fitting. The activation energies were calculated from the rate constants at a pH of 2.0 and at three different temperatures of 23℃, 60℃, and 80℃ and followed the order: Cr(III) > Fe(III) > Sc(III) > Al(III). In binary systems including Sc(III), the simultaneous adsorption of Sc(III) and other trivalent ions onto CR11 was investigated. Previously adsorbed Sc(III) on CR11 was displaced by the subsequent adsorption of Fe(III) or Cr(III) from the solution. The affinity of the metal ions to iminodiacetic acid and the adsorption reaction rate were critical factors for suitable selective Sc separation, indicating that prior removal of Fe(III) was necessary. Column experiments at 23℃ using a synthetic solution without Fe(III) showed that Cr(III) adsorption was suppressed, and that Sc(III) was efficiently adsorbed. Scandium can be efficiently recovered from a solution containing Sc(III) after prior removal of Fe(III) by adsorption at low temperature using CR11
Addition of Some Transition Elements and their Effects on the Electrochemical Properties of MgNi
In this study, some transition elements, Ag, Co, Pd, Re, Ru and Ti, at 6 and 10mol% compositions, were selected to ball mill with Mg2Ni and Ni, and the effects of transition elements on the electrochemical properties of amorphous MgNi were investigated. Three distinct effects on the electrochemical properties of MgNi were found: Ti and Pd dissolved into the bulk of MgNi during ball milling and the degradation of discharge capacity was decreased by addition of Ti and Pd. Ag and Co also dissolved in the MgNi powder, but there was no appreciable influence on the electrochemical behavior of MgNi. Re and Ru neither dissolved into MgNi nor improved the properties of MgNi
Study of Hydrogen Adsorption by V, V-Ti alloy and V-oxide through ab initio Calculations
The adsorption of hydrogen on surfaces of vanadium, vanadium-titatnium alloy and vanadium oxide was studied by ab initio calculations using Gaussian03 package. The activation and adsorption energies for adsorption were evaluated by scanning potential energy surfaces of respective systems comprising a hydrogen molecule and small cluster consisting of several metal atoms for modelling an alloy surface to reduce computational cost. The surfaces investigated were V(110), V-Ti(110), VO(111) and VO(110), diaerent cluster models being adopted for some surfaces to examine their validities and to and an appropriate cluster model and adsorption site. By comparing the results obtained by using the alloy and/or compound in diaerent cases, it was found that the activation energy for adsorption is larger for surfaces with an oxygen adlayer than for clean and Ti-covered vanadium surfaces. These andings are in good agreement with experimental observations. It was also demonstrated that diaerent cluster models for a given alloy give similar activation and adsorption energies
Effects of Pd Addition on the Electrochemical Properties of MgNi
Two groups of Pd-modified MgNi samples were prepared: sample Ⅰ, ball-milling Pd (1, 6 and 10 mol%) with amorphous MgNi for 10 min, 2hr or 10 hr, sample Ⅱ, ball-milling 10 mol% Pd with Mg2Ni and Ni for 80 hr. Effects of the addition of Pd on the electrochemical properties of MgNi were investigated. For sample Ⅰ, the effects of Pd depended on both the Pd ratio and the time of ball-milling. During ball-milling, Pd bebame amorphous and was distributed uniformly on the surface of MgNi particle. At 6 mol% and 10 mol% Pd, degradation of the discharge capacity of MgNi was significantly decreased. As for sample Ⅱ, the cycle life of MgNi was remarkably improved by Pd modification. The roles of Pd in the behavior of MgNi were analyzed, and the improvements in MgNi properties arising from both modifications by Pd were thought to be due to the prevention of the formation of Mg(OH)2
Radiation therapy for oligometastatic bone disease in breast cancer
Breast cancer (BCa) frequently metastasizes to the bone. BCa patients with oligometastatic bone diseases have much more favorable outcomes than those with metastatic bone disease. Radiation therapy (RT), especially stereotactic body radiation therapy (SBRT), is advised for the treatment of patients with oligometastatic bone disease in other primary sites. "This line of treatment provided favorable outcomes in patients and resulted in only mild toxicities. A similar strategy has been suggested for treatment of BCa patients with oligometastatic bone disease. BCa, bone-only, or high radiation dose are reported to have been associated with good outcomes in RT for metastatic disease. Furthermore, based on the guidelines provided by the BCa expert panel of the German Society for Radiation Oncology and members of the Working Party of Gynecologic Oncology Breast Committee and in line of the results obtained in other primary sites, our group supports the use of high-dose RT or SBRT for the treatment of BCa patients with oligometastatic bone disease. Additionally, the use of magnetic resonance imaging (MRI) for proper target volume definition and three-dimensional (3D) treatment planning especially for lesions of the trunk are essential for the treatment planning of RT. Of note, several clinical trials have combined RT with immune checkpoint inhibitors for the treatment of BCa patients with metastatic disease. Based on this, we anticipate that combined RT and ICI may serve as a better treatment modality for BCa patients with oligometastatic bone disease
Lung stereotactic body radiation therapy for elderly patients aged >= 80 years with pathologically proven early-stage non-small cell lung cancer: a retrospective cohort study
Background
Stereotactic body radiation therapy (SBRT) is an established therapy for medically inoperable early-stage non-small cell lung cancer (NSCLC). Many elderly patients are medically inoperable owing to comorbidities. Therefore, SBRT may be a useful therapy for elderly patients. However, the application of SBRT for patients aged ≥ 80 years has not been completely elucidated. Therefore, this study aimed to assess the clinical utility of SBRT for elderly patients aged ≥ 80 years with pathologically proven early-stage NSCLC.
Methods
We retrospectively evaluated the data of patients aged ≥ 80 years with pathologically proven primary NSCLC who underwent SBRT at our institution between January 2009 and March 2020. Treatment outcomes and toxicities were analyzed. We used the Kaplan–Meier method to estimate survival curves and the log-rank test to compare the survival curves. We performed univariate and multivariate Cox regression analyses. p-values
Results
Sixty-four patients (65 lesions) were included, and the median follow-up period was 38.7 (range 3.5–95.7) months. The median age was 82.9 (range 80.0–94.8) years. Sixteen patients were medically operable, and 48 patients were medically inoperable. The prescribed dose of SBRT was either 48 Gy in four fractions or 60 Gy in 10 fractions. The median survival time was 60.0 months (95% confidence interval, 43.5–71.1). The 1-, 3-, and 5-year local control, cancer-specific survival, progression-free survival, and overall survival rates were 98.4%, 98.4%, 81.0%, and 88.9%; 90.1%, 93.7%, 58.9%, and 68.3%; and 87.4%, 83.5%, 38.2%, and 47.5%, respectively. Multivariate analysis revealed that inoperability and solid nodules were the predictors of poor overall survival after SBRT in elderly patients. Two patients (3.1%) had grade 3 radiation pneumonitis, and one patient (1.6%) had grade 5 radiation pneumonitis.
Conclusions
SBRT was feasible in patients aged ≥ 80 years with NSCLC. It achieved good local control with minimal toxicity. SBRT may be beneficial in elderly patients with early-stage NSCLC
Radiation pneumonitis after definitive concurrent chemoradiotherapy with cisplatin/docetaxel for non-small cell lung cancer: Analysis of dose-volume parameters
Background: Radiation pneumonitis (RP) is a major pulmonary adverse event of chest radiotherapy. The PACIFIC trial that identified durvalumab as an effective subsequent-line therapy after concurrent chemoradiotherapy (CCRT) found that patients with grade 2 or higher RP may have to be excluded from treatment under certain criteria. The purpose of this study was to investigate the relationship between grade ≥2 RP and the parameters of dose-volume histograms after CCRT with cisplatin/docetaxel for stage III non-small cell lung cancer and conduct a subset analysis of severe RP that can lead to the permanent discontinuation of treatment per the PACIFIC trial criteria to help determine treatment strategy.
Methods: We calculated the percentage of the lung volume received at least 5 Gy (V5) and 20 Gy (V20), the mean lung dose (MLD), and the lung volume spared from a 5 Gy dose (VS5) to the total lung volume. Factors affecting the incidence of grade ≥2 RP were identified; severe RP was defined as grade ≥3 as well as grade 2 RP that required ≥10 mg prednisolone for at least 12 weeks.
Results: This study included 45 patients. On univariate analysis, all parameters and total lung volume were found to be significant predictors of grade ≥2 RP (P = .001, .003, .03, .004, and .02, respectively). On multivariate analysis, V20 was a significant predictive factor of grade ≥2 RP (P = .007). Severe RP developed in 6 of 37 patients (16.2%) whose V20 values were 35% or lower. On univariate analysis, only V20 was a significant predictor of severe RP in these patients (P = .01).
Conclusions: The best approach to reduce the rate of grade ≥2 RP is to maintain the V5, V20, MLD, and VS5 as low as possible during radiotherapy planning in patients receiving definitive CCRT with cisplatin/docetaxel
Clinical Outcome of Palliative Concurrent Chemoradiotherapy with Cisplatin/Docetaxel for Stage III Non-small Cell Lung Cancer
Palliative concurrent chemoradiotherapy (CCRT) is often administered to patients with stage III non-small cell lung cancer (NSCLC). We investigated the clinical outcomes of patients receiving palliative CCRT for NSCLC. Data of patients with NSCLC who underwent palliative CCRT (n=16), preoperative CCRT plus surgery (n=97), or definitive CCRT (n=48) were evaluated. In all groups, the concurrent chemotherapy regimens consisted of cisplatin and docetaxel. Rates of local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS), overall survival (OS), and prognosis were compared. The 2-year rates of LC, DMFS, PFS, and OS in 16 patients who underwent palliative CCRT were 44.4%, 12.5%, 12.5%, and 18.8%, respectively. Univariate analysis showed that palliative CCRT was associated with poor LC (p<0.001), DMFS (p<0.001), PFS (p<0.001), and OS (p<0.001) outcomes in patients who completed CCRT as a preoperative treatment and poor LC (p=0.01), DMFS (p=0.003), PFS (p=0.04), and OS (p=0.004) outcomes in patients who were considered for definitive CCRT. Although there were some long-term survivors, the clinical outcomes of palliative CCRT were significantly inferior to those of the ideal treatments. Therefore, careful determination of the appropriate treatment indications and further studies are warranted
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