648 research outputs found

    REE characteristics of Yamato-82162 and -86720 meteorites and their inference to classification

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    Abundances of REE, Ba, Sr, Rb, K, Mg, Ca and Fe were determined for Yamato-82162 and -86720 carbonaceous chondrites by mass spectrometric isotope dilution. The CI-normalized REE abundance patterns for Y-82162 are nearly flat (0.9-1.5×CI), but show small negative Ce anomalies. A small fraction of the chondrite shows a clear light/heavy REE fractionation. The REE abundance patterns of Y-86720 are also almost flat (1.4-1.9×CI) and show positive Eu anomalies. The degree of Eu anomaly seems to correlate with the absolute abundance of the REE. For the abundances of elements other than REE, Y-82162 shows enrichments of Fe and Mg and Y-86720 displays depletions of the relatively volatile elements K and Rb. From these results, the following conclusions are obtained : (1) Y-82162 may contain a high temperature component formed in the nebula. (2) Y-82162 is classified as a CI chondrite which has experienced thermal metamorphism. (3) Y-86720 is composed of a refractory-rich component and a refractory-poor component. (4) Y-86720 cannot be strictly classified into any group but is intermediate between CM and CO chondrites

    A case of synchronous bilateral breast cancer with different pathological responses to neoadjuvant chemotherapy with different biological character

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    We report a case of synchronous locally advanced bilateral breast cancer with different pathological responses to neoadjuvant chemotherapy with different biological character. The patient had presented bilateral breast cancer: the left breast cancer was hormone receptor negative, human epidermal growth factor receptor-2 (HER2) positive, and classified as T4bN1M0, stage IIIb, while the right was hormone receptor positive, HER2-negative, and classified as T4bN0M0, stage IIIb. We administered four cycles of anthracycline-based therapy followed by 12 weekly cycles of taxane with trastuzumab for neoadjuvant chemotherapy. We had achieved a significant left tumor reduction after each chemotherapy, but not right tumor. Bilateral modified radical mastectomies with axillary lymph-node dissection were performed. The therapeutic effect in the left was determined as a pathological complete response, in contrast to the right side. She has no recurrence for more than five years, though she had advanced cancer with oncologic emergency. This case could be an informative experience to understand the relation of tumor biology and response to systemic therapy

    Pharmacokinetics of Weekly Paclitaxel and Feasibility of Dexamethasone Taper in Japanese Patients with Advanced Non–small Cell Lung Cancer

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    AbstractPurposeWeekly paclitaxel combined with a platinum-based agent has been advocated as an alternative regimen for patients with advanced non–small cell lung cancer (NSCLC). Limited studies exist on the tolerability of weekly paclitaxel in Japanese patients with advanced NSCLC. Furthermore, the feasibility of dexamethasone taper in the premedication regimen for weekly paclitaxel has not been examined in these patients. To address this issue, we assessed the maximum tolerated dose, dose-limiting toxicity, and pharmacokinetics of weekly paclitaxel in Japanese patients with advanced NSCLC in a dose-escalation Phase I trial and examined the feasibility of dexamethasone taper in these patients.MethodsWeekly 1-hour infusions of paclitaxel were administered at doses of 80 to 120 mg/m2 (dose escalation of 20 mg/m2). The 7-week treatment cycle consisted of 6 infusions followed by a 2-week treatment interval. Pharmacokinetics were assessed during the first cycle. Dexamethasone was commenced at 16 mg and doses were successively halved if hypersensitivity reactions were absent.FindingsA total of 15 patients with either Stage IIIB or IV NSCLC were enrolled. Although no dose-limiting toxicity was observed at 120 mg/m2, 4 of 6 patients with peripheral neuropathy required discontinuation of treatment. The maximum accepted dose and the recommended dose were 120 and 100 mg/m2, respectively. No grade ≥3 adverse events were observed at 100 mg/m2. The maximum drug concentration and AUC correlated with dose escalation. The pharmacokinetic parameters after the first and sixth infusions were similar, indicating that repeated administration of paclitaxel did not result in drug accumulation or affect its pharmacokinetic profile. Partial response was observed in 3 of 15 patients. Plasma adrenocorticotropic hormone and cortisol levels decreased during treatment but approached baseline levels after a dexamethasone-free interval.ImplicationsWeekly paclitaxel at 100 mg/m2 given as a 1-hour infusion for 6 weeks followed by a 2-week treatment interval was well tolerated by Japanese patients with advanced NSCLC. Dexamethasone taper was feasible in these patients, and no clear trend in plasma adrenocorticotropic hormone or cortisol levels was observed

    Volatilization of alkali metals from the heated Murchison (CM2) meteorite

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    In order to examine volatilization processes of alkali metals at high temperature, heating experiments were carried out using a starting material prepared from Murchison (CM2) (grain-size : ∿10μm) at temperatures of 1200-1400℃ under a constant pressure of 8×10^ Torr, and heating duration up to 80min. Analyses of alkalis (Na, K, Rb), major and minor elements and petrographic examinations were performed for run products. Results show that fractional volatilization of alkali metals occurred during heating. It is suggested that the volatilization rates of alkali metals are influenced by the chemical composition of partial melt
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