100 research outputs found

    Third-order integrable difference equations generated by a pair of second-order equations

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    We show that the third-order difference equations proposed by Hirota, Kimura and Yahagi are generated by a pair of second-order difference equations. In some cases, the pair of the second-order equations are equivalent to the Quispel-Robert-Thomson(QRT) system, but in the other cases, they are irrelevant to the QRT system. We also discuss an ultradiscretization of the equations.Comment: 15 pages, 3 figures; Accepted for Publication in J. Phys.

    Discrete mappings with an explicit discrete Lyapunov function related to integrable mappings

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    We propose discrete mappings of second order that have a discrete analogue of Lyapunov function. The mappings are extensions of the integrable Quispel-Roberts-Thompson (QRT) mapping, and a discrete Lyapunov function of the mappings is identical to an explicit conserved quantity of the QRT mapping. Moreover we can obtain a differential and an ultradiscrete limit of the mappings preserving the existence of Lyapunov function. We also give applications of a mapping with an adjusted parameter, a probabilistic mapping and coupled mappings.Comment: submitted to Physica

    Optimizing the timing of 3.6 mg Pegfilgrastim Administration for Dose-Dense Chemotherapy in Japanese Patients with Breast Cancer

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    Perioperative dose-dense chemotherapy (DDCT) with pegfilgrastim (Peg) prophylaxis is a standard treatment for high-risk breast cancer. We explored the optimal timing of administration of 3.6 mg Peg, the dose approved in Japan. In the phase II feasibility study of DDCT (adriamycin+cyclophosphamide or epirubicin+cyclophosphamide followed by paclitaxel) for breast cancer, we investigated the feasibility, safety, neutrophil transition, and optimal timing of Peg treatment by administering Peg at days 2, 3, and 4 post-chemotherapy (P2, P3, and P4 groups, respectively). Among the 52 women enrolled, 13 were aged > 60 years. The anthracycline sequence was administered to P2 (n=33), P3 (n=5), and P4 (n=14) patients, and the taxane sequence to P2 (n=38) and P3 (n=6) patients. Both sequences showed no interaction between Peg administration timing and treatment discontinuation, treatment delay, or dose reduction. However, the relative dose intensity (RDI) was significantly different among the groups. The neutrophil count transition differed significantly among the groups receiving the anthracycline sequence. However, the neutrophil count remained in the appropriate range for both sequences in the P2 group. The timing of Peg administration did not substantially affect the feasibility or safety of DDCT. Postoperative day 2 might be the optimal timing for DDCT

    Denosumab for Treatment of a Recurrent Cervical Giant-Cell Tumor

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    A 43-year-old male patient with C5 giant cell tumor (GCT) underwent tumor resection and anterior bone fusion of C4–C6. The tumor recurred locally 9 months after surgery with the patient complaining of neck and shoulder pain similar to his preoperative symptoms. Denosumab was administered and his pain disappeared after a two-month administration, with a sclerotic rim formation seen at the tumor site on computed tomography. He has been followed for 18 months with no evidence of tumor recurrence. Complete resection is generally recommended, but is not easy for many patients with cervical GCT because of the existence of neurovascular structures. Some patients suffer from recurrence and treatment becomes more difficult. As such, denosumab may be an efficacious option for treatment of recurrent GCT of the cervical spine, although long-term follow-up is required to monitor for presence or absence of recurrence

    Assessment of the Initial Diagnostic Accuracy of a Fragility Fracture of the Sacrum: A Study of 56 Patients

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    Study Design Retrospective study. Purpose To investigate the clinical manifestations of a fragility fracture of the sacrum (FFS) and the factors that may contribute to a misdiagnosis. Overview of Literature The number of patients diagnosed with FFS has increased because of extended life expectancy and osteoporosis. Patients with FFS may report nonspecific symptoms, such as back, buttock, groin, and/or leg pain, leading to a misdiagnosis and a delay in definitive diagnosis. Methods Fifty-six patients (13 males and 43 females) with an average age of 80.2±9.2 years admitted to the hospital for FFS between 2006 and 2021 were analyzed retrospectively. The following patient data were collected using medical records: pain regions, a history of trauma, initial diagnoses, and rates of fracture detection using radiography, computed tomography (CT), and magnetic resonance imaging (MRI). Results Forty-one patients presented with low back and/or buttock pain, nine presented with groin pain, and 17 presented with thigh or leg pain. There was no history of trauma in 18 patients (32%). At the initial visit, 27 patients (48%) were diagnosed with sacral or pelvic fragility fractures. In contrast, 29 patients (52%) were initially misdiagnosed with lumbar spine disease (23 patients), hip joint diseases (three patients), and buttock bruises (three patients). Fracture detection rates for FFS were 2% using radiography, 71% using CT, and 93% using MRI. FFS was diagnosed definitively using an MRI with a coronal short tau inversion recovery (STIR) sequence. Conclusions Some patients with FFS have leg pain with no history of trauma and are initially misdiagnosed as having lumbar spine disease, hip joint disease, or simple bruises. When these clinical symptoms are reported, we recommend considering FFS as one of the differential diagnoses and performing lumbar or pelvic MRIs, particularly coronal STIR images, to rule out FFS

    Phase II trial of aflibercept with FOLFIRI as a second‐line treatment for Japanese patients with metastatic colorectal cancer

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    Aflibercept targets vascular endothelial growth factor. The present study involved assessing the efficacy, safety and pharmacokinetics of aflibercept plus 5‐fluorouracil/levofolinate/irinotecan (FOLFIRI) as a second‐line treatment for metastatic colorectal cancer (mCRC) in Japanese patients. Aflibercept (4 mg/kg) plus FOLFIRI was administered every 2 weeks in 62 patients with mCRC until disease progression, unacceptable toxicity or patient withdrawal. Tumors were imaged every 6 weeks. The primary endpoint was objective response rate (ORR); secondary endpoints were progression‐free survival, overall survival, safety, and pharmacokinetics of aflibercept, irinotecan and 5‐fluorouracil. A total of 60 patients were evaluated for ORR; 50 had received prior bevacizumab. The ORR was 8.3% (95% confidence interval [CI]: 1.3%‐15.3%), and the disease control rate (DCR) was 80.0% (69.9%‐90.1%). The median progression‐free survival was 5.42 months (4.14‐6.70 months) and the median overall survival was 15.59 months (11.20‐19.81 months). No treatment‐related deaths were observed, and no significant drug‐drug interactions were found. The most common treatment‐emergent adverse events were neutropenia and decreased appetite. Free aflibercept had a mean maximum concentration (coefficient of variation) of 73.2 μg/mL (15%), clearance of 0.805 L/d (22%) and volume of distribution of 6.2 L (18%); aflibercept bound with vascular endothelial growth factor had a clearance of 0.162 L/d (9%) (N = 62). Aflibercept did not significantly affect the pharmacokinetics of irinotecan or 5‐fluorouracil: The clearance was 11.1 L/h/m2 (28%) for irinotecan and, at steady state, 72.6 L/h/m2 (56%) for 5‐fluorouracil (N = 10). Adding aflibercept to FOLFIRI was shown to be beneficial and well‐tolerated in Japanese patients with mCRC. ClinicalTrials.gov Identifier: NCT01882868

    Direct determination of Burgers vector sense and magnitude of elementary dislocations by synchrotron white x-ray topography

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    The x-ray topography by using highly coherent beam obtained at third-generation synchrotron facilities can provide higher spatial resolution and higher lattice-distortion sensitivity than those by former-generation facilities. Here, we report the direct determination of the Burgers vector senses and magnitudes of elementary dislocations in a high-quality silicon carbide single crystal using white x-ray section topography with a long sample-to-film distance. Our data strongly indicate that there are very weak but extraordinarily long-range elastic interactions between elementary screw dislocations. Those interactions govern dislocation-propagation behavior and the distribution of dislocations. Moreover, we found that white x-ray projection topography with a long sample-to-film distance can also be a powerful tool to effectively examine the detailed structure of elementary dislocations in single crystals
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