Trace amounts of three halogens (chlorine, bromine and iodine) in seventeen U.S. Geological Survey (USGS) geochemical reference materials were determined by radiochemical neutron activation analysis ...(RNAA). The materials analysed were AGV‐2 (andesite), BCR‐2, BHVO‐2 and BIR‐1a (basalts), CLB‐1 (coal), COQ‐1 (carbonatite), DGPM‐1 (disseminated gold ore), DNC‐1a (dolerite), DTS‐2b (dunite), GSP‐2 (granodiorite), Nod‐A‐1 and Nod‐P‐1 (manganese nodules), QLO‐1a (quartz latite), SBC‐1 (marine shale), SDC‐1 (mica schist), SGR‐1b (shale rock) and W‐2a (diabase). The chlorine, bromine and iodine contents were determined to be 5.64 mg kg−1 (BIR‐1a) to 4410 mg kg−1 (Nod‐A‐1), 0.039 mg kg−1 (BIR‐1a) to 52.1 mg kg−1 (CLB‐1), and 0.041 mg kg−1 (BIR‐1a) to 599 mg kg−1 (CLB‐1), respectively. The RNAA data of the three halogens were compared with the corresponding data in the literature.
Key Points
Trace amounts of Cl, Br and I were determined by RNAA.
Inconsistencies were found between the RNAA results and literature values.
Explained by (a) I‐loss in the pretreatment of solutions analysed by ICP‐MS, (b) incomplete quantitative collection of Cl in pyrohydrolysis preconcentration prior to ICP‐MS, (c) overestimation due to interferences in ICP‐MS instruments.
The objective of this study was to evaluate the results of salvage surgery after definitive chemoradiation for hypopharyngeal squamous cell carcinoma.
This was a retrospective cohort study. Of the 79 ...patients with previously untreated hypopharyngeal squamous cell carcinoma who received definitive chemoradiation from January 2004 to January 2009, 24 who had recurrence and underwent salvage surgery at the National Cancer Center Hospital East, Chiba, Japan, were enrolled in this study.
Of the 24 patients who underwent salvage surgery with curative intent, 13 had an isolated local failure, eight had an isolated neck failure and three had combined local and regional failure. Postoperative surgical complications were observed in eight (33.3%) patients. Of the 24 patients undergoing salvage surgery, 12 (50%) had recurrence. In 11 of these patients, death ensued from salvage failure, defined as the presence of any recurrence after salvage treatment. The causes of cancer-specific death ensuing from salvage failure were regional recurrence of the tumor (n = 6) (one of whom had concurrent distant metastases) and distant metastases alone (n = 5). No local recurrence after salvage surgery was observed in our group of patients. The disease-free and overall 24-month survival rates were 49.0 and 50.0%, respectively. Those patients who initially presented with unresectable disease had lower overall survival compared with those who initially presented with resectable disease (P = 0.0003).
The oncologic outcomes were acceptable in those patients in whom salvage surgery was carried out. Those who initially presented with unresectable disease had a poor prognosis.
Combining isotope dilution mass spectrometry with a calibration method and choosing appropriate internal standard elements, 14 lanthanides (rare earth elements, REEs) were precisely and accurately ...determined for rock samples by using quadruple ICP-MS instruments. An enriched spike of 149Sm was used to determine Sm content by an isotope dilution method. Simultaneously, Sm content was determined by a calibration method and the ratio of the two Sm values was used for correcting the preparation loss of the other REEs, which were analyzed only by a calibration method. Indium and Tl were chosen for use as internal standard elements. Applying the procedure developed in this study to the homogenized Allende meteorite powder sample prepared by the Smithsonian Institution, Washington, D. C., US and several geological reference samples issued by the Geological Survey of Japan and the US geological Survey, precision and accuracy of the data obtained were evaluated and the accuracy was found to be equivalent to isotope dilution values obtained by thermal ionization mass spectrometry. Rare earth element concentrations in several meteorite samples were determined, and results indicate that our procedure is appropriate for a wide variety of whole rock compositions.
Display omitted
•Combining isotope dilution mass spectrometry with a calibration method and choosing appropriate internal standard elements, 14 lanthanides (rare earth elements) were precisely and accurately determined for rock samples by using quadrupole ICP-MS instruments. Applying the procedure developed in this study to the homogenized Allende meteorite powder sample, and Japanese and US geological reference samples, precision and accuracy of the data obtained were evaluated and found to be equivalent to isotope dilution values obtained by thermal ionization mass spectrometry.
Trace amounts of three halogens (chlorine, bromine, and iodine) were determined using radiochemical neutron activation analysis (RNAA) for nine sedimentary rocks and three rhyolite samples. To obtain ...high-quality analytical data, the radiochemical procedure of RNAA was improved by lowering the background in gamma-ray spectrometry and completing the chemical procedure more rapidly than in conventional procedures. A comparison of the RNAA data of Br and I with corresponding inductively coupled plasma mass spectrometry (ICPMS) literature data revealed that the values obtained by ICPMS coupled with pyrohydrolysis preconcentration were systematically lower than the RNAA data for some reference samples, suggesting that the quantitative collection of Br and I cannot always be achieved by the pyrohydrolysis for some solid samples. The RNAA data of three halogens can classify sedimentary rock reference samples into two groups (the samples from inland water and those from seawater), implying the geochemical significance of halogen data.
The mass fractions of Cl, Br and I were obtained by radiochemical neutron activation analysis (RNAA) of seventeen USGS geochemical reference materials (RMs), for which we had published halogen ...contents in GGR (Sekimoto and Ebihara 2017). Except for three RMs, 100 mg to > 300 mg of each powder material was used for a single analysis. After 10 min of neutron irradiation, a rapid radiochemical purification procedure was performed. Chemical yields were determined by the reactivation method. Each RM was analysed multiple times and consistent values were obtained for each element. Of the seventeen RMs, CLB‐1, DGPM‐1 and QLO‐1a were also analysed by INAA. The INAA and RNAA results for CLB‐1 and DGPM‐1agree within 4%, implying that RNAA values obtained in this study are reliable. Compared with the 2017 data, the Cl and Br values obtained in this study were consistent, but the I values were 1/4 to 1/8 lower for all samples. It is concluded that the quantitative values of Cl and Br published in GGR in 2017 are reliable, while the I values are incorrect. Therefore, it is recommended that the I contents in the USGS RMs determined in this study be substituted in place of previous values.
Key Points
We redetermined the mass fractions of Cl, Br and I in seventeen USGS geochemical RMs by RNAA.
The values from this study were compared with those previously published in GGR (Sekimoto and Ebihara 2017).
We concluded that the 2017 iodine values were erroneous and should be replaced with new values.
Abstract Objective In cases of differentiated thyroid carcinoma, the presence or absence of invasion into the circumferential organs is an important prognostic factor. Surgical procedures include ...circular resection of the trachea with end-to-end anastomosis and window resection with secondary closure. We have used window resection with secondary closure since 1993, and herein retrospectively analyze the treatment outcomes for this surgical procedure in order to determine the indications for procedure selection. Methods Subjects comprised 41 cases of invasion by differentiated thyroid carcinoma into the trachea, for which surgery was performed at the Department of Head and Neck Surgery of the National Cancer Center Hospital East from 1993 to 2007. The mean age was 65.7 ± 7.9 years, and the median length of the observation period was 43 months. There were 17 cases (41.4%) cases of secondary relapse. Results The 5-year and 10-year overall survival rates for this surgical procedure were 78.9% and 74.5%, respectively, while the 5-year and 10-year local control rates were 92.4% and 73.4%, respectively. The pathological resection stump was positive in 27 cases (65.8%), but no significant differences in treatment outcome were observed between the stump-positive group and the stump-negative group. There were 26 cases in which closure of the tracheal fistula was performed by the time of observation. When the tracheal defect had a diameter equivalent to 7 rings of the trachea or less and a circumference half that of the tracheal cartilage or smaller, including partial cricoid cartilage, it was possible to perform closure with only a local flap. For larger defects, reconstruction was performed using hard tissues or materials, such as hydroxyapatite, titanium mesh, and costal cartilage. There were 2 cases that required re-window because of dyspnea after closure. Conclusion The treatment outcomes for this surgical procedure for invasive cases of differentiated thyroid carcinoma into the trachea resulted in a low rate of local recurrence and similar survival rates as described in other reports. Even for cases of resection exceeding half the circumference of the trachea, closure of the tracheal fistula can be performed using hard tissues or materials; however, in such cases, we believe that closure should be attempted progressively in a two-stage reconstruction.
Lunar meteorite Northwest Africa (NWA) 2977 is identified as an olivine cumulate gabbro (OC), consisting of coarse cumulate olivine crystals up to 1 mm with low-Ca and high-Ca pyroxenes, plagioclase, ...and interstitial incompatible element-rich pockets of K-feldspar, Ca-phosphates, ilmenite, and troilite. These minerals and textures are similar to those of the OC clasts of the NWA 773 clan of meteorites. NWA 2977 contains a variety of pyroxene textures and compositions including augite, pigeonite, and rare orthopyroxene, all having exsolution lamellae. Some of the orthopyroxene has abundant augite lamellae with compositions indicating formation by inversion of pigeonite. This pigeonite was inverted at 1140 °C according to the pigeonite eutectoid reaction (PER) temperatures. Inverted pigeonite has not been found previously in the NWA 773 clan of meteorites. The presence of inverted pigeonite indicates that NWA 2977 cooled more slowly than most other OC clasts of the NWA 773 clan. The relatively slow cooling of NWA 2977 can be explained by formation in a deeper level of the original igneous body of the NWA 773 clan OC lithology.
The lunar meteorite Northwest Africa (NWA) 2200 is a regolith breccia with a ferroan feldspathic bulk composition (Al2O3 = 30.1 wt.%; Mg# = molar 100 × Mg/(Mg + Fe) = 59.2) and low Th content ...(0.42 μg/g). Lithologically, NWA 2200 is a diverse mixture of lithic and glassy clasts, mineral fragments, and impact glass spherules, all embedded in a dark glassy matrix. NWA 2200 contains some feldspathic brecciated rock components (ferroan anorthositic granulitic breccia, poikiloblastic granulitic breccia, and glassy melt breccia with an intersertal texture). The bulk compositions of these brecciated components indicate they are derived from ferroan troctolitic or noritic anorthosite lithologies (bulk Al2O3 = 26–30 wt.%; bulk FeO/MgO > 1.0). The bulk composition of NWA 2200 is more ferroan and feldspathic than the Apollo feldspathic regolith samples and feldspathic lunar regolith meteorites, and is also more depleted in incompatible elements (e.g., rare earth elements) than Apollo 16 feldspathic regolith samples. We conclude that NWA 2200 originated from a location different to the Apollo landing sites, and may have been sourced from the ferroan KREEP-poor highlands, “KREEP” materials are enriched in such elements as potassium (K), rare earth elements (REE), phosphorus (P).
•REEs, Th, U and P were precisely and accurately determined in 15 R chondrites.•R chondrites are slightly enriched in heavy REEs with a small, positive Ce anomaly.•CI-like and refractory-rich REEs ...were mixed in the R chondrite parent body.•A mean Th/U ratio of R chondrites is 5.1% higher than the CI ratio.•Phosphorus and REE contents are negatively correlated in R chondrites.
Rare earth elements (REEs), Th, U and P were determined in 15 Rumuruti (R)-type chondrites and the Allende CV chondrite. Repeated analyses of Allende for REEs, Th and U by ICP-MS and P by ICP-AES, and comparisons of these data with literature values ensure high reproducibility (precision) and reliability (accuracy) of acquired data. CI-normalized REE abundances in R chondrites are slightly enriched in heavy REEs with a small, positive Ce anomaly, in contrast to Allende. CI-normalized Pr/Tm and Nd/Yb ratios show a positive correlation, suggesting the heterogeneous mixing of two components (CI-like and refractory-rich materials) during the accretion of the R chondrite parent body. A Ce anomaly, however, was likely homogeneously present in the nebula. A mean Th/U ratio of R chondrites is 3.81±0.13(1σ), which is 5.1% higher than the CI ratio. Probably, the Th–U fractionation was inherited from the nebula from which the R chondrite parent body formed. Besides the Th–U fractionation, REEs and Th–U are heterogeneously fractionated in R chondrites, for which parent body processing is assumed to be the cause. A mean P content of R chondrites (1254 μg/g) is higher than for any ordinary chondrite and is close to the EL mean. There appears to be a negative correlation between P and REEs contents in R chondrites. It is probable that REEs were diluted by extraneously supplied, REEs-depleted and P-containing materials (schreibersite or metal). This process must have occurred heterogeneously during accretion so that the heterogeneity of P-containing materials was preserved in the R chondrite parent body and individual R chondrites.
PDF
