143 research outputs found

    Vegetation change in the regional surface climate over East Asia due to global warming using BIOME4

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    This study investigates the possible changes in the regional surface climate due to global warming from a MM5 downscaling simulation for the period of 1971-2100. The main focus of this study is to observe the changes in vegetation types over East Asia. BIOME4, an equilibrium terrestrial biosphere model, is utilized to simulate vegetation patterns. Regional projections of this study show the increase of surface air temperature by 5◦C and precipitation by 6% over East Asia in the end of the 21st century. The present study also noticed that the increasing trend of temperature is associated with the increasing trends of the minimum temperature of the coldest month. Therefore, the region of favorable temperature conditions for vegetation growth in lower latitudes seems to extend toward the higher latitude. It leads to a northward shift of vegetation distribution in the lower latitudes besides the area extension. For instance, the trend in which the warm mixed forest and temperate deciduous forest shift northward may be distinguished. At the same time, the area of temperate deciduous forest pervades the area and replaces temperate grassland regions. Of interest, the tropical evergreen forest is expected to appear over southern China in the end of the 21st century. The possible vegetation changes are mainly affected by a temperature increase rather than a precipitation increase

    Comparative study on multibody vehicle dynamics models based on subsystem synthesis method using Cartesian and joint coordinates

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    AbstractThe subsystem synthesis method has been developed in order to improve computational efficiency for a multibody vehicle dynamics model. Using the subsystem synthesis method, equations of motion of the base body and each subsystem can be solved separately. In the subsystem synthesis method, various coordinate systems can be used and various integration methods can be applied in each subsystem, as long as the effective mass matrix and the effective force vector are properly produced. In this paper, comparative study has been carried out for the subsystem synthesis method with Cartesian coordinates and with joint relative coordinates. Two different integration methods such as an explicit integrator and an explicit implicit integrator are employed. In order to see the accuracy and computational efficiency from the different models based on the different coordinate systems and different integration methods, a rough terrain run simulations has been carried out with a 6 × 6 off-road multibody vehicle model

    Detection of distant metastasis to skeletal muscle by 18F-FDG-PET in a case of intrahepatic cholangiocarcinoma

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    Intrahepatic cholangiocarcinoma is a rare malignancy that originates from the epithelial cells of the intrahepatic bile ducts. Intrahepatic cholangiocarcinoma can metastasize in lymphatic chains, including the hepatoduodenal ligament, and it often invades adjacent organs or metastasizes to other visceral organs such as the lungs, bones, adrenal glands, and brain. However, distant skeletal muscle metastasis is very rare. Moreover, a metastatic skeletal muscle tumor rarely shows specific symptoms, making it difficult to identify in a routine examination. A 45-year-old man with a chief complaint of right upper quadrant abdominal pain was admitted to our hospital. Abdominal ultrasound and computed tomography with contrast enhancement showed a malignant mass in the right hepatic lobe, and 2-[18F] fluoro-2-deoxy-D-glucose positron-emission tomography revealed distant skeletal muscle metastases in the thorax and buttock. The patient underwent an ultrasound-guided percutaneous needle biopsy for the metastatic low-echo masses in the skeletal muscle

    The usefulness of transient elastography, acoustic-radiation-force impulse elastography, and real-time elastography for the evaluation of liver fibrosis

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    Background/AimsSeveral noninvasive methods have recently been developed for the evaluation of liver fibrosis. The accuracy of transient elastography (TE), acoustic-radiation-force impulse (ARFI) elastography, and real-time elastography (RTE) in predicting liver fibrosis were evaluated.MethodsSeventy-four patients who had undergone a liver biopsy within the previous 6 months were submitted to evaluation with TE, ARFI, and RTE on the same day.ResultsThere were significant correlations between fibrosis stage and liver stiffness measurement (LSM) using the three tested methods: TE, r2=0.272, P=0.0002; ARFI, r2=0.225, P=0.0017; and RTE, r2=0.228, P=0.0015. The areas under the receiver operating characteristic curves (AUROC) for the diagnosis of significant fibrosis (≥F2, Metavir stage) by TE, ARFI, RTE, TE/platelet count (PLT), velocity of shear wave (Vs)/PLT, and elasticity score (Es)/PLT were 0.727, 0.715, 0.507, 0.876, 0.874, and 0.811, respectively. The AUROC for the diagnosis of cirrhosis by TE, ARFI, RTE, TE/PLT, Vs/PLT, and Es/PLT were 0.786, 0.807, 0.767, 0.836, 0.819, and 0.838, respectively. Comparisons of AUROC between all LSMs for predicting significant fibrosis (≥F2) produced the following results: TE vs. RTE, P=0.0069; ARFI vs. RTE, P=0.0277; and TE vs. ARFI, P=0.8836. Applying PLT, the ability of each LSM to predict fibrosis stage significantly increased: TE/PLT vs. TE, P=0.0004; Vs/PLT vs. ARFI, P=0.0022; and Es/PLT vs. RTE, P<0.0001. However, the ability to predict cirrhosis was not enhanced, combining LSM and PLT.ConclusionsTE and ARFI may be better methods for predicting significant liver fibrosis than RTE. This predictive ability increased significantly when accounting for platelet count. However, all of the measures had comparable efficacies for predicting cirrhosis

    Effect of High-Temperature Annealing on Ion-Implanted Silicon Solar Cells

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    P-type and n-type wafers were implanted with phosphorus and boron, respectively, for emitter formation and were annealed subsequently at 950∼1050∘C for 30∼90 min for activation. Boron emitters were activated at 1000∘C or higher, while phosphorus emitters were activated at 950∘C. QSSPC measurements show that the implied Voc of boron emitters increases about 15 mV and the J01 decreases by deep junction annealing even after the activation due to the reduced recombination in the emitter. However, for phosphorus emitters the implied Voc decreases from 622 mV to 560 mV and the J01 increases with deep junction annealing. This is due to the abrupt decrease in the bulk lifetime of the p-type wafer itself from 178 μs to 14 μs. PC1D simulation based on these results shows that, for p-type implanted solar cells, increasing the annealing temperature and time abruptly decreases the efficiency (Δηabs=−1.3%), while, for n-type implanted solar cells, deep junction annealing increases the efficiency and Voc, especially (Δηabs=+0.4%) for backside emitter solar cells

    CD82/KAI1 Maintains the Dormancy of Long-Term Hematopoietic Stem Cells through Interaction with DARC- Expressing Macrophages

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    Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we examine the role of CD82/ KAI1 in niche-mediated LT-HSC maintenance. We found that CD82/ KAI1 is expressed predominantly on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs). In Cd82 +/-/+/- mice, LTHSCs were selectively lost as they exited from quiescence and differentiated. Mechanistically, CD82based TGF-b1/ Smad3 signaling leads to induction of CDK inhibitors and cell-cycle inhibition. The CD82 binding partner DARC/ CD234 is expressed on macrophages and stabilizes CD82 on LT-HSCs, promoting their quiescence. When DARC + BMmacrophages were ablated, the level of surface CD82 on LT-HSCs decreased, leading to cell-cycle entry, proliferation, and differentiation. A similar interaction appears to be relevant for human HSPCs. Thus, CD82 is a functional surface marker of LT-HSCs that maintains quiescence through interaction with DARC-expressing macrophages in the BM stem cell niche.113525Ysciescopu

    Establishment of Efficacy and Safety Assessment of Human Adipose Tissue-Derived Mesenchymal Stem Cells (hATMSCs) in a Nude Rat Femoral Segmental Defect Model

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    Human adipose tissue-derived mesenchymal stem cell (hATMSC) have emerged as a potentially powerful tool for bone repair, but an appropriate evaluation system has not been established. The purpose of this study was to establish a preclinical assessment system to evaluate the efficacy and safety of cell therapies in a nude rat bone defect model. Segmental defects (5 mm) were created in the femoral diaphyses and transplanted with cell media (control), hydroxyapatite/tricalcium phosphate scaffolds (HA/TCP, Group I), hATMSCs (Group II), or three cell-loading density of hATMSC-loaded HA/TCP (Group III-V). Healing response was evaluated by serial radiography, micro-computed tomography and histology at 16 weeks. To address safety-concerns, we conducted a GLP-compliant toxicity study. Scanning electron microscopy studies showed that hATMSCs filled the pores/surfaces of scaffolds in a cell-loading density-dependent manner. We detected significant increases in bone formation in the hATMSC-loaded HA/TCP groups compared with other groups. The amount of new bone formation increased with increases in loaded cell number. In a toxicity study, no significant hATMSC-related changes were found in body weights, clinical signs, hematological/biochemical values, organ weights, or histopathological findings. In conclusion, hATMSCs loaded on HA/TCP enhance the repair of bone defects and was found to be safe under our preclinical efficacy/safety hybrid assessment system
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