Identifying the driver of pulsating aurora     

Nishimura Y  Bortnik J  Li W  Thorne RM  Lyons LR  Angelopoulos V  Mende SB  Bonnell JW  Le Contel O  Cully C  Ergun R  Auster U 《Science (New York, N.Y.)》2010,330(6000):81-84

Pulsating aurora, a spectacular emission that appears as blinking of the upper atmosphere in the polar regions, is known to be excited by modulated, downward-streaming electrons. Despite its distinctive feature, identifying the driver of the electron precipitation has been a long-standing problem. Using coordinated satellite and ground-based all-sky imager observations from the THEMIS mission, we provide direct evidence that a naturally occurring electromagnetic wave, lower-band chorus, can drive pulsating aurora. Because the waves at a given equatorial location in space correlate with a single pulsating auroral patch in the upper atmosphere, our findings can also be used to constrain magnetic field models with much higher accuracy than has previously been possible.  相似文献   

Comparison of key aroma compounds in five different types of Japanese soy sauces by aroma extract dilution analysis (AEDA)     

Kaneko S  Kumazawa K  Nishimura O 《Journal of agricultural and food chemistry》2012,60(15):3831-3836

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Identification of a Germicidal Compound against Picornavirus in Bamboo Pyroligneous Acid     

S Marumoto  SP Yamamoto  H Nishimura  K Onomoto  M Yatagai  K Yazaki  T Fujita  T Watanabe 《Journal of agricultural and food chemistry》2012,60(36):9106-9111

The germicidal activity of pyroligneous acid (PA) against a picornavirus, encephalomyocarditis virus (EMCV), was analyzed, and the component responsible for its disinfectant activity was identified. Bamboo PA (BPA) inactivated EMCV, but neutralization of BPA abolished this activity. Using liquid-liquid phase extraction and silica gel column chromatography, the hydrophobic active fraction of BPA was separated and its 12 major components were identified. The active fraction was reconstructed by mixing synthetic chemicals at the determined concentrations, and a subtraction series of one chemical from the complete mixture was prepared. An in vitro virus assay demonstrated that phenol was the sole germicidal component, and acetic acid augmented the phenol's inactivating activity resulting in >5-log decrease in EMCV infectivity. Considering the low environmental risk of PA, these findings suggest that BPA is a potentially useful agent for preventing viral epidemics in agricultural and human environments.  相似文献   

Nitrous oxide evolved from soil covered with plastic mulch film in horticultural field   总被引：1，自引：0，他引：1  

Seiichi Nishimura  Michio Komada  Masako Takebe  Seiichiro Yonemura  Naoto Kato 《Biology and Fertility of Soils》2012,48(7):787-795

Soil solarization practice, in which soil is covered with plastic mulch film and exposed to high temperature prior to crop cultivation, is expected to be an effective method for reducing weeds and pathogenic microorganisms without using agricultural chemicals. Although the production of nitrous oxide (N₂O), a major greenhouse gas, is enhanced in fertilized soil covered with plastic mulch films, its transport route to the atmosphere has not been sufficiently elucidated to date. In this study, we investigated the N₂O evolution from plastic-mulch-film-covered agricultural soil. In a horticultural field where ridge soil was covered with a plastic mulch film after fertilization, we observed significant N₂O flux from the soil surface of the unfertilized furrow between the ridges, indicating the horizontal diffusion of N₂O from the ridge soil covered with the mulch film to the adjacent furrow soil surface. On the other hand, the measurement of the permeance (permeation coefficient) of the plastic mulch film for gaseous N₂O by laboratory experiment revealed that N₂O gradually permeated the mulch film; the permeance increased exponentially with an increase in ambient temperature, indicating possible N₂O emission by permeation through the mulch film under field conditions. In winter, the amount of N₂O emission by permeation through the mulch film was estimated to be lower than that emitted from the furrow soil surface, and it was lower than that in summer. On the other hand, it was estimated to be much higher in summer owing to the higher permeance of the film at high temperatures.  相似文献   

Triterpenoids isolated from Zizyphus jujuba inhibit foam cell formation in macrophages     

Fujiwara Y  Hayashida A  Tsurushima K  Nagai R  Yoshitomi M  Daiguji N  Sakashita N  Takeya M  Tsukamoto S  Ikeda T 《Journal of agricultural and food chemistry》2011,59(9):4544-4552

Because foam cell formation in macrophages is believed to play an essential role in the progression of early atherosclerotic lesions in vivo, prevention of foam cell formation is considered to be one of the major targets for the treatment of atherosclerosis. The present study examined the inhibitory effect of 50 crude plant extracts on foam cell formation. Among those crude extracts, Zizyphi Fructus (ZF) and Zizyphi Semen (ZS) extracts significantly inhibited the foam cell formation induced by acetylated LDL. Furthermore, triterpenoids such as oleanonic acid, pomolic acid, and pomonic acid were the major active compounds, and triterpenoids containing a carboxylic acid at C-28 play an important role in the inhibitory effect on foam cell formation in human macrophages. These data suggest that triterpenoids in Zizyphus jujuba , the plant source of ZF and ZS, may therefore be useful for the prevention of atherosclerosis.  相似文献   

Computed tomographic lymphangiography via intra‐metatarsal pad injection is feasible in dogs with chylothorax     

Lee‐Shuan Lin  Hsien‐Chieh Chiu  Ryohei Nishimura  Reina Fujiwara  Cheng‐Shu Chung 《Veterinary radiology & ultrasound》2020,61(4):435-443

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Establishment of an in vitro culture model to study milk production and the blood–milk barrier with bovine mammary epithelial cells     

Yusaku Tsugami  Norihiro Suzuki  Manabu Kawahara  Takahiro Suzuki  Takanori Nishimura  Ken Kobayashi 《Animal Science Journal》2020,91(1)

This study attempted to establish a culture model to recreate the milk production pathway in bovine mammary epithelial cells (BMECs). BMECs were isolated from Holstein cows (nonlactating, nonpregnant, and parous) and were stored by cryopreservation. To separate the apical and basolateral compartments, BMECs were cultured on a cell culture insert with a collagen gel in the presence of bovine pituitary extract and dexamethasone to induce milk production and tight junction (TJ) formation. The culture model showed the secretion of the major milk components, such as β‐casein, lactose, and triglyceride, and formed less‐permeable TJs in BMECs. Moreover, the TJs were distinctly separated from the apical and basolateral membranes. Glucose transporter‐1, which transports glucose into the cytoplasm through the basolateral membrane, localized in the lateral membrane of BMECs. Toll‐like receptor‐4, which binds to lipopolysaccharide in the alveolar lumen in mastitis, localized in the apical membrane. Beta‐casein was mainly localized near the Golgi apparatus and the apical membrane. Moreover, milk components were almost secreted into the upper chamber of the cell culture insert. These findings indicate that this model has clear cell polarity as well as in vivo and is effective to study of milk production and the blood–milk barrier in lactating BMECs.  相似文献   

Histopathological significance of microRNA-210 expression in acute peripheral ischemia in a murine femoral artery ligation model     

Yuichi Takai  Satoshi Nishimura  Hitoshi Kandori  Takeshi Watanabe 《Journal of toxicologic pathology》2020,33(4):211

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Methods for inoculum production and inoculation of Cistella japonica,the causal agent of resinous stem canker in Chamaecyparis obtusa     

T. Yamanobe  Y. Oribe  K. Nishimura 《Forest Pathology》2008,38(1):29-36

The ascomycete Cistella japonica was cultured on potato dextrose agar medium (PDA) for inoculation into Chamaecyparis obtusa, enabling the development of an inoculation method suitable for use in a breeding programme aimed at selecting for families of Ch. obtusa resistant to resinous stem canker. Using PDA to generate the inoculum resolved the problems encountered with the previously used mixed medium of rice bran and wheat bran, including unfavourable characteristics, uncertain growth of Ci. japonica mycelia, and a complex culturing operation. The inoculation test induced resin exudation similar to that observed in natural infections, and reproduced clonal differences with regard to damage severity.  相似文献   

The soil seed bank of the threatened plant <Emphasis Type="Italic">Magnolia stellata</Emphasis> is subordinate to the emergence of current-year seedlings     

Hiromitsu Kisanuki  Hisae Oguro  Arisa Nakai  Suzuki Setsuko  Naoyuki Nishimura  Nobuhiro Tomaru 《Journal of Forest Research》2008,13(2):143-146

We studied seed bank formation of the threatened star magnolia, Magnolia stellata, to examine the early stage of regeneration. Forty-five seedling plots (2 × 2 m), each including a soil-sampling quadrat (40 × 40 cm), were established randomly under or around the crowns of mature M. stellata trees. Seeds of M. stellata were collected from each quadrat to a depth of 5 cm. Only four seeds of M. stellata were found (0.56 seeds/m²) and all were located under mature crowns. Current-year seedlings were abundant in water channels, on moss, or under mature crowns, suggesting that the seeds may require wet soil conditions for germination. Magnolia stellata seeds show considerable germination below the crowns of mature trees in the year following masting, while some seeds remain dormant in the soil. Considering the soil seed bank and the current-year seedling bank of M. stellata, a frequent supply of seed is essential for the regeneration of this species. Thus, it is important to maintain mature trees in addition to promoting seed production.  相似文献