Acquisition of isotopic composition for surface snow in East Antarctica and the links to climatic parameters

The isotopic compositions of oxygen and hydrogen in ice cores are invaluable tools for the reconstruction of past climate variations. Used alone, they give insights into the variations of the local temperature, whereas taken together they can provide information on the climatic conditions at the point of origin of the moisture. However, recent analyses of snow from shallow pits indicate that the climatic signal can become erased in very low accumulation regions, due to local processes of snow reworking. The signal-to-noise ratio decreases and the climatic signal can then only be retrieved using stacks of several snow pits. Obviously, the signal is not completely lost at this stage, otherwise it would be impossible to extract valuable climate information from ice cores as has been done, for instance, for the last glaciation. To better understand how the climatic signal is passed from the precipitation to the snow, we present here results from varied snow samples from East Antarctica. First, we look at the relationship between isotopes and temperature from a geographical point of view, using results from three traverses across Antarctica, to see how the relationship is built up through the distillation process. We also take advantage of these measures to see how second-order parameters (d-excess and O-17-excess) are related to delta O-18 and how they are controlled. d-excess increases in the interior of the continent (i.e., when delta O-18 decreases), due to the distillation process, whereas O-17-excess decreases in remote areas, due to kinetic fractionation at low temperature. In both cases, these changes are associated with the loss of original information regarding the source. Then, we look at the same relationships in precipitation samples collected over 1 year at Dome C and Vostok, as well as in surface snow at Dome C. We note that the slope of the delta O-18 vs. temperature (T) relationship decreases in these samples compared to those from the traverses, and thus caution is advocated when using spatial slopes for past climate reconstruction. The second-order parameters behave in the same way in the precipitation as in the surface snow from traverses, indicating that similar processes are active and that their interpretation in terms of source climatic parameters is strongly complicated by local temperature effects in East Antarctica. Finally we check if the same relationships between delta O-18 and second-order parameters are also found in the snow from four snow pits. While the d-excess remains opposed to delta O-18 in most snow pits, the O-17-excess is no longer positively correlated to delta O-18 and even shows anti-correlation to delta O-18 at Vostok. This may be due to a stratospheric influence at this site and/or to post-deposition processes

日本-スウェーデン共同南極トラバース2007/2008 実施報告：I. 企画立案・事前準備と科学研究成果の概要

南極地域観測第Ⅶ期5か年計画に基づき，2007/2008 年の南極の夏期シーズンに，国立極地研究所を中心とした研究グループは，スウェーデンの研究者グループと共同で，東南極内陸域のドロンイングモードランド地域の内陸部の氷床環境調査を実施した．本報告は，現地調査前に5年間を費やした研究計画の企画検討の経過や行った事前準備と，現地野外観測を終了した後の6年間に得られた研究成果の概要をまとめるものである．本プロジェクトの調査により，南極内陸高原部の氷床環境の時空間分布について，多くの科学的知見が明らかになった．本報告はその概要を報告する．現地調査の実行の経過は別途の報告に記述する．In the seventh five-year plan of the Japanese Antarctic Research Expedition, a group of Japanese scientists (led by the National Institute of Polar Research) together with a group of Swedish scientists, conducted field surveys to better understand the glaciology of the ice sheet in Dronning Maud Land, East Antarctica, during the 2007/2008 austral summer season. This paper reports on the planning and field preparations, and outlines the scientific achievements of the field expedition. We have gained numerous new scientific insights on the spatio-temporal distribution of the ice sheet environment in the inland plateau. Here, we provide an overview of the new knowledge gained

Cardiomyopathy in a dog with multicentric lymphoma following treatment with several anthracyclines

Background: Canine lymphoma is one of the most frequently occurring malignant neoplasms in dogs. Anthracycline-based chemotherapy for the treatment of canine lymphoma is very effective; however, there is not enough evidence for the development of cardiac toxicity using several anthracyclines as chemotherapeutic agents. Case Description: An 8-year-old, castrated, mixed-breed dog was diagnosed with multicentric lymphoma and received multi-agent chemotherapy. Complete remission was achieved, but the patient had a relapse of lymphoma. After third-line chemotherapy with epirubicin, the patient was diagnosed with dilated cardiomyopathy. The total cumulative doses of doxorubicin, mitoxantrone, and epirubicin were 125, 8, and 125 mg/m2, respectively. Although the patient was treated with cardiac drugs and clinically stabilized, the patient had a relapse of lymphoma and died shortly after the diagnosis of cardiomyopathy. Conclusion: The patient was suspected to have anthracycline-induced cardiomyopathy. Further studies are required to establish prevention and management strategies for dogs receiving potentially cardiotoxic therapies such as anthracyclines

Electronic Effects of Nitrogen Atoms of Supports on Pt-Ni Rhombic Dodecahedral Nanoframes for Oxygen Reduction

Pt-based nanostructures immobilized on carbon supports have been widely used as electrocatalysts. Their catalytic activity can be improved by support modification including nitrogen doping and coating with nitrogen-containing polymers, where nitrogen atoms possibly interact with surface Pt atoms at a catalyst/support interface. To understand electronic effects of nitrogen-doped and polymer-coated carbon supports on the catalytic activity of Pt-based nanostructured catalysts, we prepared Pt3Ni nanoframes (NFs) supported on polybenzimidazole (PBI)-coated and uncoated carbon nanotubes for the oxygen reduction reaction (ORR), and then compared their catalytic activities and electronic properties with those of NFs immobilized on nitrogen-doped and undoped carbon supports. Although both PBI-coating and nitrogen-doping approaches improved the catalytic activity of NFs, ex situ X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy revealed that nitrogen doping showed electronic effects on NFs, whereas PBI-coating showed almost no impact on the electronic state of NFs but stabilized Pt(OH)ad species under electrochemical conditions. Our studies demonstrate that difference in microscopic environments of nitrogen atoms at the catalyst/support interface is highly sensitive to the electronic effects of supports on Pt-based electrocatalysts

Secondary right atrial thrombosis in three dogs: Antithrombotics therapy and echocardiographic follow‐up

Abstract Three dogs were diagnosed with right atrial thrombosis, thought to be secondary to systemic diseases. Specifically, two cases had hyperadrenocorticism and one case was diagnosed with pancreatitis with acute renal injury. In all cases, the thrombi were found within the right atrium, necessitating a differentiation from cardiac neoplasia. In all three cases, the structures assumed to be thrombi had irregular margins with interspersed hypoechoic regions, which were later confirmed as thrombi based on the responsiveness to therapy. All three cases were prescribed with the combination of clopidogrel and rivaroxaban.The thrombi gradually disappeared after initiation of the combination therapy. Complete resolution of right atrial thrombosis was noted in each dog treated with clopidogrel and rivaroxaban. This combination therapy appears to be safe and well tolerated. Diligent observation of the echocardiographic findings and clinical course allows the diagnosis of thrombosis

アリルエストレノールによる前立腺肥大症の治療中断後, PSA値の回復に必要な期間についての検討

Decrease in serum prostate specific antigen (PSA) concentration is inevitably associated with antiandrogen therapy for benign prostatic hyperplasia (BPH), and might mask the presence of prostate cancer or delay its diagnosis. To determine the appropriate timepoint for determination of correct PSA value, we sequentially measured serum PSA and testosterone levels after discontinuation of antiandrogen therapy for BPH. With informed consent, 12 patients (72.8 +/- 12.2* years old) with BPH were treated with allylestrenol 50 mg/day for 4 months. Serum testosterone and PSA concentrations were determined before and just after treatment, as well as every month after treatment up to 3 months. After treatment with allylestrenol for 4 months, mean serum testosterone and PSA levels were significantly decreased from 408 +/- 136* to 87.9 +/- 76.2* ng/dl, and from 2.81 +/- 0.87* to 2.04 +/- 0.82* ng/ml, respectively. The mean serum PSA level recovered to the pretreatment level within 2 months and mean serum testosterone concentration within one month after discontinuation of administration. In conclusion, during treatment of BPH with antiandrogen allylestrenol, a two-month washout is adequate for determination of correct PSA value (*: M +/- SD).前立腺肥大症をアンチアンドロゲン剤にて治療するとテストステロンの低下にともないPSAが低下する.これにより前立腺癌の診断が遅れることが危惧されている.しかしながら, アンチアンドロゲン剤の中断後4ヵ月で, 両者とも完全に前値に復することをすでに報告した.PSA4.0ng/ml以下の前立腺肥大症の症例においてアンチアンドロゲン剤中断後のテストステロンとPSAの変化を経時的に観察し, 治療前値に復するまでに要する期間につき検討した.症例は平均72.8±2.2歳前立腺肥大症(前立腺体積:36.7±7.9ml)患者でアンチアンドロゲン剤による治療およびテストステロン, PSAの経時的採血に文書同意を得た12症例である.アリルエストレノール50mg/dayを4ヵ月間投与した.これを中断後1ヵ月ごとに採血してテストステロンとPSAを経時的に観察した.アリルエストレノールの投与4ヵ月でテストステロンは低下し, これに伴いPSAも有意に低下した.治療の中断後1ヵ月でテストステロンは前値に復し, PSAは中断後2ヵ月でほぼ前値に復した.以上より, 前立腺肥大症のアリルエストレノールによる治療中に正確なPSA値を知るために必要なアリルエストレノールのwashout期間は, ほぼ2ヵ月であることが示唆された(著者抄録

Spatial distributions of soluble salts in surface snow of East Antarctica

To better understand how sea salt reacts in surface snow of Antarctica, we collected and identified non-volatile particles in surface snow along a traverse in East Antarctica. Samples were obtained during summer 2012/2013 from coastal to inland regions within 69°S to 80°S and 39°E to 45°E, a total distance exceeding 800 km. The spatial resolution of samples is about one sample per latitude between 1500 and 3800 m altitude. Here, we obtain the atomic ratios of Na, S and Cl, and calculate the masses of sodium sulphate and sodium chloride. The results show that, even in the coast snow sample (69°S), sea salt is highly modified by acid (HNO3 or H2SO4). The fraction of sea salt that reacts with acid increases in the region from 70°S to 74°S below 3000 m a.s.l., where some NaCl remains. At the higher altitudes (above 3300 m a.s.l.) in the inland region (74°S to 80°S), the reaction uses almost all of the available NaCl