331 research outputs found

    A precise study on undrained shear behavior of hydrate-bearing pressure core from the Eastern Nankai Trough

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    Experimental variable effects on laser heating of inclusions during Raman spectroscopic analysis

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    Raman spectroscopy for fluid, melt, and mineral inclusions provides direct insight into the physicochemical conditions of the environment surrounding the host mineral at the time of trapping. However, the obtained Raman spectral characteristics such as peak position are modified because of local temperature enhancement of the inclusions by the excitation laser, which might engender systematic errors and incorrect conclusions if the effect is not corrected. Despite the potentially non-negligible effects of laser heating, the laser heating coefficient (B) (°C/mW) of inclusions has remained unsolved. For this study, we found B from experiments and heat transport simulation to evaluate how various parameters such as experimental conditions, mineral properties, and inclusion geometry affect B of inclusions. To assess the parameters influencing laser heating, we measured B of a total of 19 CO2-rich fluid inclusions hosted in olivine, orthopyroxene, clinopyroxene, spinel, and quartz. Our results revealed that the measured B of fluid inclusions in spinel is highest (approx. 6 °C/mW) and that of quartz is lowest (approx. 1 × 10−2 °C/mW), consistent with earlier inferences. Our simulation results show that the absorption coefficient of the host mineral is correlated linearly with B. It is the most influential parameter when the absorption coefficient of the host mineral (αh) is larger than that of an inclusion (αinc). Furthermore, although our results indicate that both the inclusion size and depth have little effect on B if αh > αinc, the thickness and radius of the host mineral slightly influence B. These results suggest that the choice of inclusion size and depth to be analyzed in a given sample do not cause any systematic error in the Raman data because of laser heating, but the host radius and thickness, which can be adjusted to some degree at the time of sample preparation, can cause systematic errors between samples.Our results demonstrate that, even with laser power of 10 mW, which is typical for inclusion analysis, the inclusion temperature rises to tens or hundreds of degrees during the analysis, depending especially on the host mineral geometry and optical properties. Therefore, correction of the heating effects will be necessary to obtain reliable data from Raman spectroscopic analysis of inclusions. This paper presents some correction methods for non-negligible effects of laser heating

    Bis[Ό-3,5-bis­(2-pyrid­yl)pyrazolato]bis­(hydrogensulfato)­dicopper(II) methanol disolvate

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    The title compound, [Cu2(C13H9N4)2(HSO4)2]·2CH3OH, consists of discrete centrosymmetric dinuclear complex mol­ecules and methanol solvent mol­ecules. The CuII atom shows a square-pyramidal coordination geometry and is bonded to four N atoms of the two bis-chelating 3,5-bis­(2-pyrid­yl)pyrazol­ate ions (bpypz−) and one O atom of the hydrogensulfate ion. The bpypz− ligands in the complex mol­ecule are virtually coplanar [dihedral angle between the mean ligand planes = 0.000(1)°] with the CuII atom deviating in opposite directions from their best plane by 0.2080 (12) Å. π–π stacking inter­actions between the pyridyl and pyrazole rings [centroid–centroid distance = 3.391 (3) Å] and strong O—H⋯O hydrogen bonds between the hydrogensulfate ligands and the methanol mol­ecules assemble the mol­ecules into a one-dimensional polymeric structure extending along the a axis. The methanol mol­ecule acts both as an accepter and a donor in the hydrogen bonding

    Cognitive Abilities Related to Reading and Writing Skills in Chinese Third-grade Children

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    In this study, we analysed the cognitive abilities that predict reading and writing attainment in the Chinese language for Mandarin-speaking children. A total of 140 Chinese third-graders studying in Ningbo, Zhejiang were evaluated for their visual cognition including visual perception and memory, naming speed, vocabulary knowledge, phonological skills, nonverbal intelligence, and abilities to read and write. The results of multiple regression analyses revealed that word and nonword reading accuracy were predicted to a significant degree by visual memory and phonological awareness, respectively. Naming speed significantly contributed to the reading speeds regarding words, nonwords, and paragraphs. Our results also showed that the scores in word and nonword reading predicted the scores of writing as well. Visual memory and phonological awareness are essential for reading Chinese accurately, while naming speed is an important factor for Chinese reading fluency. The present results have implications regarding the design of useful tasks that screen poor readers of Chinese

    Development of high-pressure low-temperature plane strain testing apparatus for methane hydrate-bearing sand

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    AbstractA high-pressure low-temperature plane strain testing apparatus was developed for visualizing the deformation of methane hydrate-bearing sand due to methane hydrate production. Using this testing apparatus, plane strain compression tests were performed on pure Toyoura sand and methane hydrate-bearing sand with localized deformation measurements. From the results, it was observed that the methane hydrate-free specimens, despite their relatively high density, showed changes in compressive volume. Marked increases in the initial stiffness and strength of the methane hydrate-bearing sand were observed (methane hydrate saturation of SMH=60%). Moreover, the volumetric strain changed from compressive to dilative. For the specimens with methane hydrate, a dilative behavior above SMH=0% was observed. An image analysis showed that the shear bands of the methane hydrate-bearing sand were thinner and steeper than those of the host sand. In addition, the dilative volumetric strain in the shear band increased markedly when methane hydrate existed in the pore spaces

    Exportin-5 orthologues are functionally divergent among species

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    Exportin-5, an evolutionarily conserved nuclear export factor belonging to the importin-ÎČ family of proteins, is known to play a role in the nuclear export of small noncoding RNAs such as precursors of microRNA, viral minihelix RNA and a subset of tRNAs in mammalian cells. In this study, we show that the exportin-5 orthologues from different species such as human, fruit fly and yeast exhibit diverged functions. We found that Msn5p, a yeast exportin-5 orthologue, binds double-stranded RNAs and that it prefers a shorter 22 nt, double-stranded RNA to ∌80 nt pre-miRNA, even though both of these RNAs share a similar terminal structure. Furthermore, we found that Drosophila exportin-5 binds pre-miRNAs and that amongst the exportin-5 orthologues tested, it shows the highest affinity for tRNAs. The knockdown of Drosophila exportin-5 in cultured cells decreased the amounts of tRNA as well as miRNA, whereas the knock down of human exportin-5 in cultured cells affected only miRNA but not tRNA levels. These results indicate that double-stranded RNA binding ability is an inherited functional characteristic of the exportin-5 orthologues and that Drosophila exportin-5 functions as an exporter of tRNAs as well as pre-miRNAs in the fruit fly that lacks the orthologous gene for exportin-t

    Retrograde Jejuno-Jejunal Intussusception after Total Gastrectomy

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    An eighty-year-old female was transferred to the hospital after experiencing abdominal pain and nausea. She had had a history of total gastrectomy for gastric cancer 14 years previously. Abdominal X-ray revealed a localized expansion of the small bowel. Computed tomography revealed a mass with a lamellar structure in a concentric circle. With a tentative diagnosis of small bowel obstruction due to intussusception, she underwent emergency operation. Laparotomy revealed a retrograde jejuno-jejunal intussusception. Bowel resection was performed due to the severe ischemic damage. All reported intussusception cases after total gastrectomy displayed retrograde characteristics and could occur both during the early and late period after surgery. It is important to consider the possibility of intussusception for patients presenting with acute abdomen who have previously undergone gastric resection

    LACTATE/MCT4/GPR81 AXIS IN BONE PAIN OF BREAST CANCER

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    Breast cancer (BC) bone metastasis causes bone pain (BP), which detrimentally damages the quality of life and outcome of patients with BC. However, the mechanism of BC‑BP is poorly understood, and effective treatments are limited. The present study demonstrated a novel mechanism of BC‑BP using a mouse model of bone pain, in which mouse (EO771) and human (MDA‑MB‑231) BC cells were injected in the bone marrow cavity of tibiae. Western blot analysis using sensory nerves, in vivo assessment of cancer pain and in vitro calcium flux analysis were performed. These mice developed progressive BC‑BP in tibiae in conjunction with an upregulation of phosphorylated pERK1/2 and cAMP‑response element‑binding protein (pCREB), which are molecular indicators of neuron excitation, in the dorsal root ganglia (DRG) of sensory nerves. Importantly, mice injected with BC cells, in which the expression of the lactic acid transporter monocarboxylate transporter 4 (MCT4) was silenced, exhibited decreased BC‑BP with downregulated expression of pERK1/2 and pCREB in the DRG and reduced circulating levels of lactate compared with mice injected with parental BC cells. Further, silencing of the cell‑surface orphan receptor for lactate, G protein‑coupled receptor 81 (GPR81), in the F11 sensory neuron cells decreased lactate‑promoted upregulation of pERK1/2 and Ca2+ influx, suggesting that the sensory neuro excitation was inhibited. These results suggested that lactate released from BC cells via MCT4 induced BC‑BP through the activation of GPR81 of sensory neurons. In conclusion, the activation of GPR81 of sensory neurons by lactate released via MCT4 from BC was demonstrated to contribute to the induction of BC‑BP, and disruption of the interactions among lactate, MCT4 and GPR81 may be a novel approach to control BC‑BP

    Antiresorptive agent-related osteonecrosis of the jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw

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    Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan

    Synchronous Total Occlusion of the Celiac Axis and Superior Mesenteric Artery: An Autopsy Case

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    Acute mesenteric ischemia (AMI) is often caused by superior mesenteric artery (SMA) embolization. We report a rare case of synchronous celiac axis and SMA embolization in an elderly woman with initially mild abdominal pain. Ultimately, a second contrast-enhanced computed tomography revealed extensive necrosis from the stomach to the transverse colon together with liver ischemia due to hours of occlusion. Multiorgan failure made palliation the only option, and she died the following evening. Autopsy revealed a fragile atherosclerosis-asso-ciated thrombus. Careful examination and repeat diagnostic tests should be performed in patients with mild abdominal symptoms at risk for AMI
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