Hydrogen effects on nanoindentation behavior of metallic glass ribbons

Recently, metallic glass (MG) membranes that are permeable to hydrogen have gained interest due to the increasing importance of hydrogen separation in a number of applications, e.g., hydrogen-powered fuel cells. An important issue in the context of MG membranes is the hydrogen-induced embrittlement and efforts to understand the role played by hydrogen in the mechanical properties, especially yielding and plastic deformation behavior, of MGs are being made. In this study, therefore, an attempt was made by performing nanoindentation tests with cube-corner and spherical indenter tips on a series of Ni–Nb–Zr amorphous alloy ribbons to investigate the hydrogen effects on nanohardness and pop-in behavior (Figure 1). Weight gain measurements after hydrogen charging and thermal desorption spectroscopy (TDS) studies (Figure 2) were utilized to identify how the total hydrogen is partitioned into mobile and immobile parts. These, in turn, indicate the significant role of hydrogen mobility in the amorphous structure on the mechanical properties. In high-Zr alloys containing immobile H, both hardness (H) and shear yielding stress (τmax) increase significantly; while in low-Zr alloys having only mobile hydrogen, decrease in hardness and τmax were noted (Figure 1). The changes in shear transformation zone (STZ) volume, estimated through cumulative analysis of τmax, caused by hydrogen absorption were also found to depend on hydrogen mobility such that immobile hydrogen reduces the STZ volume while mobile hydrogen increases it. *This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2013R1A1A2A10058551)

Glacial history and depositional environments in little Storfjorden and Hambergbukta of Arctic Svalbard since the younger dryas

Geophysical and lithological data provide crucial information for the understanding of glacial history in Arctic Svalbard. In this study, we reconstructed the glacier-induced depositional environments of Little Storfjorden and its tributary, Hambergbukta, over the last 13 ka to better understand the glacial history of southeastern Svalbard. The combined uses of swath-bathymetry, high-resolution seismic stratigraphy, and multiple-proxy measurements of sediment cores allowed us to define five steps of glacier-induced depositional environments: 1) deposition of massive, semi-consolidated gravelly sandy mud (Facies 1) during re-advance or still-stand of the marine-based glaciers/ice streams in Little Storfjorden during Younger Dryas (13–12 ka); 2) deposition of massive mud to gravelly sandy mud (Facies 2A and B) during glacial retreat until the earliest Holocene (12–10.1 ka); 3) sediment winnowing by enhanced bottom currents during the early to middle Holocene (10.1–3.7 ka); 4) deposition of bioturbated sandy mud (Facies 3) with high productivity under seasonal sea ice conditions during the late Holocene (3.7–0.7 ka); and 5) deposition of (slightly) bioturbated sandy to gravelly mud (Facies 4) affected by glacier surges since Little Ice Age (LIA) (Facies 4). In addition to seismic stratigraphy, depositional patterns of IRD in Little Storfjorden indicate that the glacier surges in Hambergbukta occurred only after ∼0.7 ka. This suggests that the terminal moraine complex (TMC) represents the maximum extent of the LIA surges, which argues against the recent inference for the TMC formation during pre-LIA. This study shows the importance of multiple parameters to better understand the current behavior of tidewater glaciers in the Svalbard fjords in response to rapid climate change

Collision of Three Histologically Distinct Endometrial Cancers of the Uterus

A collision tumor is defined by the presence of two separate masses in one organ, which are pathologically distinct. We described a 70-yr-old patient who complained of abnormal vaginal bleeding with a collision tumor of the uterine corpus. The patient received total hysterectomy, bilateral salphingo-oophorectomy, bilateral pelvic-paraaortic lymphadenectomy, omentectomy, and intraperitoneal chemotherapy. The uterine corpus revealed three separate masses, which were located at the fundus, anterior and posterior wall. Each tumor revealed three pathologically different components, which were malignant mixed müllerian tumor, papillary serous carcinoma, and endometrioid adenocarcinoma. Among these components, only the papillary serous carcinoma component invaded the underlying myometrium and metastasized to the regional lymph node. Adjuvant chemotherapy and radiation therapy were performed. The patient is still alive and has been healthy for the last 8 yr. We have reviewed previously reported cases of collision tumors which have occurred in the uterine corpus

Effects of warming and eutrophication on coastal phytoplankton production

Phytoplankton production in coastal waters influences seafood production and human health and can lead to harmful algal blooms. Water temperature and eutrophication are critical factors affecting phytoplankton production, although the combined effects of warming and nutrient changes on phytoplankton production in coastal waters are not well understood. To address this, phytoplankton production changes in natural waters were investigated using samples collected over eight months, and under 64 different initial conditions, established by combining four different water temperatures (i.e., ambient T, + 2, + 4, and + 6 degrees C), and two different nutrient conditions (i.e., non-enriched and enriched). Under the non-enriched conditions, the effect of warming on phytoplankton production was significantly positive in some months, significantly negative in others, or had no effect. However, under enriched conditions, warming affected phytoplankton production positively in all months except one, when the salinity was as low as 6.5. These results suggest that nutrient conditions can alter the effects of warming on phytoplankton production. Of several parameters, the ratio of initial nitrate concentration to chlorophyll a concentration [NCCA, mu M (pg L-1)(-1))] was one of the most critical factors determining the directionality of the warming effects. In laboratory experiments, when NCCA in the ambient or nutrient-enriched waters was >= 1.2, warming increased or did not change phytoplankton production with one exception; however, when NCCA was < 1.2, warming did not change or decreased production. In the time series data obtained from the coastal waters of four target countries, when NCCA was 1.5 or more, warming increased phytoplankton production, whereas when NCCA was lower than 1.5, warming lowered phytoplankton production, Thus, it is suggested that NCCA could be used as an index for predicting future phytoplankton production changes in coastal waters.11Ysciescopu

A Case of a Pulmonary Arteriovenous Malformation With Ebstein's Anomaly

A pulmonary arteriovenous malformation (PAVM) is a rare pulmonary vascular anomaly presenting as dyspnea or recurrent epistaxis. Ebstein's anomaly (EA), a congenital cardiac malformation, is also a rare condition. There have been no reports concerning the co-existence of PAVM with hereditary hemorrhagic telangiectasia (HHT) and EA. A 40-year-old woman was admitted with a 2-month history of increasing dyspnea and several years of recurrent epistaxis. On transthoracic echocardiography, she was diagnosed with EA and agreed to undergo surgical treatment. A chest CT angiography showed a 12-mm serpiginous vascular structure suspicious for a PAVM and a liver CT suggested HTT. Although it is unclear whether or not a concurrent PAVM and EA have an embryologic or genetic relationship, we report a case of a PAVM with EA. Further genetic and embryonic studies are needed to identify a possible relationship of the two medical conditions

Risk factors for multi-drug resistant Acinetobacter baumannii bacteremia in patients with colonization in the intensive care unit

<p>Abstract</p> <p>Background</p> <p>Epidemic outbreaks of multi-drug resistant (MDR) <it>Acinetobacter baumannii </it>(AB) in intensive care units (ICUs) are increasing. The incidence of MDR AB bacteremia, which develops as a result of colonization, is increasing through widespread dissemination of the pathogen, and further colonization. We sought to determine risk factors for MDR AB bacteremia in patients colonized with MDR AB in the ICU.</p> <p>Methods</p> <p>We conducted a retrospective, observational study of 200 patients colonized with MDR AB in the ICU at Severance Hospital, South Korea during the outbreak period between January 2008 and December 2009.</p> <p>Results</p> <p>Of the 200 patients colonized with MDR AB, 108 developed MDR AB bacteremia, and 92 did not. APACHE II scores were higher in bacteremic than non-bacteremic patients at the time of ICU admission and colonization (24.0 vs. 21.6; <it>P </it>= 0.035, 22.9 vs. 16.8; <it>P </it>< 0.001, respectively). There was no difference between the two groups in the duration of time from ICU admission to colonization (7.1 vs. 7.2 days; <it>P </it>= 0.923), but the duration of time at risk was shorter in bacteremic patients (12.1 vs. 6.0 days; <it>P </it>= 0.016). A recent invasive procedure was a significant risk factor for development of bacteremia (odds ratio = 3.85; 95% CI 1.45-10.24; <it>P </it>= 0.007). Multivariate analysis indicated infection and respiratory failure at the time of ICU admission, maintenance of mechanical ventilation, maintenance of endotracheal tube instead of switching to a tracheostomy, recent central venous catheter insertion, bacteremia caused by other microorganism after colonization by MDR AB, and prior antimicrobial therapy, were significant risk factors for MDR AB bacteremia.</p> <p>Conclusions</p> <p>Patients in the ICU, colonized with MDR AB, should be considered for minimizing invasive procedures and early removal of the invasive devices to prevent development of MDR AB bacteremia.</p

The genome sequence of Xanthomonas oryzae pathovar oryzae KACC10331, the bacterial blight pathogen of rice

The nucleotide sequence was determined for the genome of Xanthomonas oryzae pathovar oryzae (Xoo) KACC10331, a bacterium that causes bacterial blight in rice (Oryza sativa L.). The genome is comprised of a single, 4 941 439 bp, circular chromosome that is G + C rich (63.7%). The genome includes 4637 open reading frames (ORFs) of which 3340 (72.0%) could be assigned putative function. Orthologs for 80% of the predicted Xoo genes were found in the previously reported X.axonopodis pv. citri (Xac) and X.campestris pv. campestris (Xcc) genomes, but 245 genes apparently specific to Xoo were identified. Xoo genes likely to be associated with pathogenesis include eight with similarity to Xanthomonas avirulence (avr) genes, a set of hypersensitive reaction and pathogenicity (hrp) genes, genes for exopolysaccharide production, and genes encoding extracellular plant cell wall-degrading enzymes. The presence of these genes provides insights into the interactions of this pathogen with its gramineous host