149 research outputs found

    Analysis of 37-kW Converter-Fed Induction Motor Losses

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    This paper presents an energy efficiency analysis of a 37-kW standard squirrel-cage induction motor under sinusoidal and nonsinusoidal supply. The motor losses are analyzed using the conventional IEC loss segregation method and also numerically modeled using finite-element simulations. The measured and simulated loss components are compared with three different modulation methods. The overall simulated losses are in good agreement with the measured ones, but there exist differences in the loss components

    Slotless PM machines with skewed winding shapes:3D electromagnetic modeling

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    The 3D modeling technique presented in this paper, predicts, with high accuracy, electromagnetic fields and corresponding dynamic effects in conducting regions for rotating machines with slotless windings, e.g. self-supporting windings. The presented modeling approach can be applied to a wide variety of slotless winding configurations, including skewing and/or different winding shapes. It is capable to account for induced eddy-currents in the conductive rotor parts, e.g. permanent magnet eddy-current losses, albeit not iron and winding AC losses. The specific focus of this paper is to provide the reader with the complete implementation and assumptions details of such a 3D semi-analytical approach, which allows model validations with relatively short calculation times. This model can be used to improve future design optimizations for machines with 3D slotless windings. It has been applied, in this paper, to calculate fixed parameter Faulhaber, Rhombic, and Diamond slotless PM machines to illustrate accuracy and applicability

    Effects of manufacturing tolerances of permanent magnets in fractional slot permanent magnet synchronous machines

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    The fractional slot permanent magnet synchronous machines are well-known for their low torque ripple. However, in mass-production machines, not all the permanent magnets are identical due to the manufacturing tolerances and new torque harmonics could appear. In addition, the magnetic field is modified and unbalanced magnetic pull (UMP) could happen. Apart from that it is important to study the effect on vibrations since the magnetic field is no longer ideal. So, here, a study of the effect of unevenly magnetised permanent magnet distribution on torque ripples, unbalance magnetic pull, and vibrations is proposed. Apart from that, the tolerance grade sensitivity is studied. Finally, experimental tests show good agreement with finite element analysis

    Marimastat as maintenance therapy for patients with advanced gastric cancer: a randomised trial

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    This randomised, double-blind, placebo-controlled study was designed to evaluate the ability of the orally administered matrix metalloproteinase inhibitor, marimastat, to prolong survival in patients with non-resectable gastric and gastro-oesophageal adenocarcinoma. Three hundred and sixty-nine patients with histological proof of adenocarcinoma, who had received no more than a single regimen of 5-fluorouracil-based chemotherapy, were randomised to receive either marimastat (10 mg b.d.) or placebo. Patients were treated for as long as was tolerable. The primary endpoint was overall survival with secondary endpoints of time to disease progression and quality of life. At the point of protocol-defined study completion (85% mortality in the placebo arm) there was a modest difference in survival in the intention-to-treat population in favour of marimastat (P=0.07 log-rank test, hazard ratio=1.23 (95% confidence interval 0.98–1.55)). This survival benefit was maintained over a further 2 years of follow-up (P=0.024, hazard ratio=1.27 (1.03–1.57)). The median survival was 138 days for placebo and 160 days for marimastat, with 2-year survival of 3% and 9% respectively. A significant survival benefit was identified at study completion in the pre-defined sub-group of 123 patients who had received prior chemotherapy (P=0.045, hazard ratio=1.53 (1.00–2.34)). This benefit increased with 2 years additional follow-up (P=0.006, hazard ratio=1.68 (1.16–2.44)), with 2-year survival of 5% and 18% respectively. Progression-free survival was also significantly longer for patients receiving marimastat compared to placebo (P=0.009, hazard ratio=1.32 (1.07–1.63)). Marimastat treatment was associated with the development of musculoskeletal pain and inflammation. Events of anaemia, abdominal pain, jaundice and weight loss were more common in the placebo arm. This is one of the first demonstrations of a therapeutic benefit for a matrix metalloproteinase inhibitor in cancer patients. The greatest benefit was observed in patients who had previously received chemotherapy. A further randomised study of marimastat in these patients is warranted

    A meta-analysis of two randomised trials of early chemotherapy in asymptomatic metastatic colorectal cancer

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    This report constitutes a prospectively planned meta-analysis combining two almost identical trials undertaken in Australasia and Canada to study the effect of starting chemotherapy immediately in asymptomatic patients with metastatic colorectal cancer. Patients (n=168) were randomised to receive either immediate or delayed treatment (at onset of predefined symptoms). Australasian patients received either weekly 5-fluorouracil and leucovorin (500 and 20 mg m−2, respectively) (n=59) or the daily × 5 Mayo Clinic schedule (425 and 20 mg m−2, respectively) (n=42). Canadian patients were treated with the Mayo schedule (n=67). Otherwise, the two studies were almost identical in design and each used the European Organisation for the Research and Treatment of Cancer (EORTC) QLQ-C30 instrument for measuring quality of life (QoL). Treatment was continued until 6 months had elapsed or disease progression occurred. Low accrual led to trial suspension before the predetermined sample size for either study was reached. Median survival was not significantly better with immediate treatment (median 13.0 vs 11.0 months; hazard ratio, 1.15; 95% confidence interval (CI) 0.79–1.72; P=0.49). There was no statistically significant difference in progression-free survival (time from randomisation until first evidence of progression after chemotherapy, 10.2 vs 10.8 months; hazard ratio, 1.08; 95% CI 0.71–1.64; P=0.73). There was no difference in overall QoL or its individual domains between the two treatment strategies at baseline or at any subsequent time point. Early treatment of asymptomatic patients with metastatic colorectal cancer did not provide a survival benefit or improved QoL compared to withholding treatment until symptoms occurred

    Schuldig landschap. Over de toeristische aantrekkingskracht van Baantjer, Wallander en Inspector Morse

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    De opnamelokaties van tv-detectives genieten een toenemende populariteit onder toeristen. In dit artikel wordt, op basis van een tekstuele analyse van ‘Baantjer’, ‘Inspector Morse’ en ‘Wallander’, onderzocht welke inhoudelijke kenmerken van deze tv-detectives mogelijk als ‘trigger’ fungeren. Uit de analyse blijkt dat plaats en beweging een centrale rol vervullen binnen de narratieve structuur van dit genre. Door zelf de lokaties te bezoeken, kunnen toeristen het spoor nalopen van hun geliefde detective om aldaar, vanuit een veilige positie, tijdelijk op te gaan in het schemergebied tussen fictie en werkelijkheid

    Fulvestrant is an effective and well-tolerated endocrine therapy for postmenopausal women with advanced breast cancer: results from clinical trials

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    Fulvestrant (‘Faslodex’) is a new type of endocrine treatment – an oestrogen receptor (ER) antagonist that downregulates the ER and has no agonist effects. Early efficacy data from phase I/II trials have demonstrated fulvestrant to be effective and well tolerated. Two randomised phase III trials have compared the efficacy of fulvestrant and the aromatase inhibitor, anastrozole, in postmenopausal women with advanced breast cancer progressing on prior endocrine therapy. Fulvestrant (intramuscular injection 250 mg month−1) was found to be at least as effective as anastrozole (orally 1 mg day−1) for time to progression (5.5 vs 4.1 months, respectively (hazard ratio (HR): 0.95; 95.14% confidence interval (CI), 0.82–1.10; P=0.48)) and objective response 19.2 vs 16.5%, respectively; treatment difference 2.75%; 95.14% CI, −2.27 to 9.05%; P=0.31). More recently, fulvestrant has also been shown to be noninferior to anastrozole in terms of overall survival, with median time to death being 26.4 months in fulvestrant-treated patients and 24.2 months in those treated with anastrozole (HR: 0.97; 95% CI, 0.78–1.21; P=0.82). In a further randomised phase III trial, fulvestrant was compared with tamoxifen as first-line therapy for advanced disease in postmenopausal women. In the overall population, efficacy differences favoured tamoxifen and noninferiority of fulvestrant could not be ruled out. In the prospectively defined subset of patients with ER-positive and/or progesterone receptor-positive disease, there was no statistically significant difference between fulvestrant and tamoxifen. This paper reviews the efficacy and tolerability results from these trials

    A retrospective analysis of second-line chemotherapy in patients with advanced gastric cancer

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    <p>Abstract</p> <p>Background</p> <p>Because treatment of advanced gastric cancer (AGC) patients after failure with first-line chemotherapy remains controversial, we performed this retrospective analysis based on the data obtained from 1455 patients registered in a first-line treatment cohort with respect to receiving or not receiving subsequent chemotherapy.</p> <p>Methods</p> <p>The decision for administering second-line chemotherapy was, in most cases, at the discretion of the physician. Seven-hundred twenty-five (50%) received second-line chemotherapy after first-line failure. Univariate and multivariate analyses were performed on the recognized baseline parameters for survival.</p> <p>Results</p> <p>At the time of initiating second-line chemotherapy, the patients' median age was 56 years (range, 22 to 86) and 139 (19%) had an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or more. Seven (1%) complete and 108 (15%) partial responses to second-line chemotherapy were observed for an overall response rate of 16% (95% confidence interval [CI], 13 to 19%). The median progression-free and overall survivals, calculated from the start of second-line chemotherapy, were 2.9 months (95% CI, 2.6 to 3.3) and 6.7 months (95% CI, 5.8 to 7.5), respectively. Multivariate analysis revealed that low baseline hemoglobin level (hazard ratio [HR], 0.74; 95% CI 0.61–0.90) and a poor performance status (HR, 0.66; 95% CI, 0.52–0.83) were independent negative prognostic factors for overall survival.</p> <p>Conclusion</p> <p>Performance status, along with baseline hemoglobin level, could be used to identify the subgroup of patients most likely to benefit from second-line chemotherapy for AGC.</p

    Phase I study of epirubicin, cisplatin and capecitabine plus matuzumab in previously untreated patients with advanced oesophagogastric cancer

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    To evaluate the safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of the humanised antiepidermal growth factor receptor monoclonal antibody matuzumab combined with epirubicin, cisplatin and capecitabine (ECX) in patients as first-line treatment for advanced oesophagogastric cancer that express epidermal growth factor receptor (EGFR). This was a phase I dose escalation study of matuzumab at 400 and 800 mg weekly and 1200 mg every 3 weeks combined with ECX (epirubicin 50 mg m−2, cisplatin 60 mg m−2 on day 1 and capecitabine 1000 mg m−2 daily). Patients were treated until disease progression, unacceptable toxicity or for a maximum of eight cycles. Twenty-one patients were treated with matuzumab at three different dose levels (DLs) combined with ECX. The main dose-limiting toxicity (DLT) was grade 3 lethargy at 1200 mg matuzumab every 3 weeks and thus 800 mg matuzumab weekly was the maximum-tolerated dose (MTD). Other common toxicities included rash, nausea, stomatitis and diarrhoea. Pharmacokinetic evaluation demonstrated that the coadministration of ECX did not alter the exposure of matuzumab. Pharmacodynamic studies on skin biopsies demonstrated inhibition of the EGFR pathway. Objective response rates of 65% (95% confidence interval (CI): 43–82), disease stabilisation of 25% (95% CI: 11–47) and a disease control rate (CR+PR+SD) of 90% were achieved overall. The MTD of matuzumab in combination with ECX was 800 mg weekly, and at this DL it was well-tolerated and showed encouraging antitumour activity. At the doses evaluated in serial skin biopsies, matuzumab decreased phosphorylation of EGFR and MAPK, and increased phosphorylation of STAT-3
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