低圧、低圧力

関: hypobaric、hypotonia、low-pressure

WordNet

(of muscular tissue) the state of being hypotonic (同)hypotonus, hypotonicity
not forceful; "a low-pressure salesman"; "a low-pressure campaign"
unrefined in character; "low comedy"
an air mass of lower pressure; often brings precipitation; "a low moved in over night bringing sleet and snow" (同)depression
a low level or position or degree; "the stock market fell to a new low"
used of sounds and voices; low in pitch or frequency (同)low-pitched
very low in volume; "a low murmur"; "the low-toned murmur of the surf" (同)low-toned
in a low position; near the ground; "the branches hung low"
less than normal in degree or intensity or amount; "low prices"; "the reservoir is low"
literal meanings; being at or having a relatively small elevation or upward extension; "low ceilings"; "low clouds"; "low hills"; "the sun is low"; "low furniture"; "a low bow"
the force applied to a unit area of surface; measured in pascals (SI unit) or in dynes (cgs unit); "the compressed gas exerts an increased pressure" (同)pressure level, force per unit area
an oppressive condition of physical or mental or social or economic distress
the somatic sensation that results from applying force to an area of skin; "the sensitivity of his skin to pressure and temperature was normal" (同)pressure_sensation
a force that compels; "the public brought pressure to bear on the government"
British political cartoonist (born in New Zealand) who created the character Colonel Blimp (1891-1963) (同)David Low, Sir David Low, Sir David Alexander Cecil Low

PrepTutorEJDIC

低圧の;低気圧の
(高さ・位置が)『低い』,低い所にある / (価格・数量・程度などが)『低い』,少ない / (身分・地位などが)『低い』,卑しい / (人格・行為などが)『卑しい』,下劣な,下品な / 《補語にのみ用いて》(体が)『弱った』;元気のない,憂うつな / (供給が)不十分な;(…が)乏しい《+『in』(『on』)+『名』》 / (音・声が)低い,小さい / (生物が)下等な / 『低く』,低い所に / (価格・程度などが)『安く』,低く / 低い声(調子)で;静かに / 最低点,最低水準
(牛の)モーという鳴き声 / (牛が)モーと鳴く
〈U〉『押すこと』,『押しつけること』,圧搾,圧縮;〈C〉〈U〉『圧力』,圧力の強さ / 〈U〉『圧迫』,『強制』 / 〈U〉(不快な)圧迫感 / 〈C〉〈U〉(精神的な)重荷,苦脳;(時間・金銭的)切迫 / 〈U〉多忙,あわただしさ / 《おもに米》…‘に'圧力をかける,強制する(《英》pressurise)
見よ,そら
liter[s]

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/06/14 22:41:04」(JST)

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[Wiki en表示]

A clockwise spinning low pressure area or cyclone off southern Australia. The center of the spiral-shaped cloud system is also the center of a low, and usually is where the pressure is lowest.

This low-pressure system over Iceland spins counter-clockwise due to balance between the Coriolis force and the pressure gradient force.

A low-pressure area, low, or depression is a region where the topographic map is atmospheric pressure is lower than that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere. The formation process of a low-pressure area is known as cyclogenesis. Within the field of meteorology, atmospheric divergence aloft occurs in two areas. The first area is on the east side of upper troughs, which form half of a Rossby wave within the Westerlies (a trough with large wavelength that extends through the troposphere). A second area of wind divergence aloft occurs ahead of embedded shortwave troughs, which are of smaller wavelength. Diverging winds aloft ahead of these troughs cause atmospheric lift within the troposphere below, which lowers surface pressures as upward motion partially counteracts the force of gravity.

Thermal lows form due to localized heating caused by greater sunshine over deserts and other land masses. Since localized areas of warm air are less dense than their surroundings, this warmer air rises, which lowers atmospheric pressure near that portion of the Earth's surface. Large-scale thermal lows over continents help drive monsoon circulations. Low-pressure areas can also form due to organized thunderstorm activity over warm water. When this occurs over the tropics in concert with the Intertropical Convergence Zone, it is known as a monsoon trough. Monsoon troughs reach their northerly extent in August and their southerly extent in February. When a convective low acquires a well-hot circulation in the tropics it is termed a tropical cyclone. Tropical cyclones can form during any month of the year globally, but can occur in either the northern or southern hemisphere during November.

Atmospheric lift will also generally produce cloud cover through adiabatic cooling once the air becomes saturated as it rises, although the low-pressure area typically brings cloudy skies, which act to minimize diurnal temperature extremes. Since clouds reflect sunlight, incoming shortwave solar radiation decreases, which causes lower temperatures during the day. At night the absorptive effect of clouds on outgoing longwave radiation, such as heat energy from the surface, allows for warmer diurnal low temperatures in all seasons. The stronger the area of low pressure, the stronger the winds experienced in its vicinity. Globally, low-pressure systems are most frequently located over the Tibetan Plateau and in the lee of the Rocky mountains. In Europe (particularly in the United Kingdom), recurring low-pressure weather systems are typically known as "depressions".

Formation

Cyclogenesis is the development and strengthening of cyclonic circulations, or low-pressure areas, within the atmosphere.^[1] Cyclogenesis is the opposite of cyclolysis, and has an anticyclonic (high-pressure system) equivalent which deals with the formation of high-pressure areas—anticyclogenesis.^[2] Cyclogenesis is an umbrella term for several different processes, all of which result in the development of some sort of cyclone. Meteorologists use the term "cyclone" where circular pressure systems flow in the direction of the Earth's rotation,^[3]^[4] which normally coincides with areas of low pressure.^[5]^[6] The largest low-pressure systems are cold-core polar cyclones and extratropical cyclones which lie on the synoptic scale. Warm-core cyclones such as tropical cyclones, mesocyclones, and polar lows lie within the smaller mesoscale. Subtropical cyclones are of intermediate size.^[7]^[8] Cyclogenesis can occur at various scales, from the microscale to the synoptic scale. Larger-scale troughs, also called Rossby waves, are synoptic in scale.^[9] Shortwave troughs embedded within the flow around larger scale troughs are smaller in scale, or mesoscale in nature.^[10] Both Rossby waves and shortwaves embedded within the flow around Rossby waves migrate equatorward of the polar cyclones located in both the Northern and Southern hemispheres.^[11] All share one important aspect, that of upward vertical motion within the troposphere. Such upward motions decrease the mass of local atmospheric columns of air, which lowers surface pressure.^[12]

Extratropical cyclones form as waves along weather fronts due to a passing by shortwave aloft or upper level jet streak^{[clarification needed]} before occluding later in their life cycle as cold-core cyclones.^[13]^[14]^[15]^[16] Polar lows are small-scale, short-lived atmospheric low-pressure systems that occur over the ocean areas poleward of the main polar front in both the Northern and Southern Hemispheres. They are part of the larger class of mesoscale weather-systems. Polar lows can be difficult to detect using conventional weather reports and are a hazard to high-latitude operations, such as shipping and gas- and oil-platforms. They are vigorous systems that have near-surface winds of at least 17 metres per second (38 mph).^[17]

This depiction of the Hadley cell shows the process which sustains low-pressure areas. Diverging winds aloft allow for lower pressure and convergence at the Earth's surface, which leads to upward motion.

Tropical cyclones form due to latent heat driven by significant thunderstorm activity, and are warm-core with well-defined circulations.^[18] Certain criteria need to be met for their formation. In most situations, water temperatures of at least 26.5 °C (79.7 °F) are needed down to a depth of at least 50 m (160 ft);^[19] waters of this temperature cause the overlying atmosphere to be unstable enough to sustain convection and thunderstorms.^[20] Another factor is rapid cooling with height, which allows the release of the heat of condensation that powers a tropical cyclone.^[19] High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.^[19] Low amounts of wind shear are needed, as high shear is disruptive to the storm's circulation.^[19] Lastly, a formative tropical cyclone needs a pre-existing system of disturbed weather, although without a circulation no cyclonic development will take place.^[19] Mesocyclones form as warm core cyclones over land, and can lead to tornado formation.^[21] Waterspouts can also form from mesocyclones, but more often develop from environments of high instability and low vertical wind shear.^[22]

In deserts, lack of ground and plant moisture that would normally provide evaporative cooling can lead to intense, rapid solar heating of the lower layers of air. The hot air is less dense than surrounding cooler air. This, combined with the rising of the hot air, results in a low-pressure area called a thermal low.^[23] Monsoon circulations are caused by thermal lows which form over large areas of land and their strength is driven by how land heats more quickly than the surrounding nearby ocean. This generates a steady wind blowing toward the land, bringing the moist near-surface air over the oceans with it.^[24] Similar rainfall is caused by the moist ocean-air being lifted upwards by mountains,^[25] surface heating,^[26] convergence at the surface,^[27] divergence aloft, or from storm-produced outflows at the surface.^[28] However the lifting occurs, the air cools due to expansion in lower pressure, which in turn produces condensation. In winter, the land cools off quickly, but the ocean keeps the heat longer due to its higher specific heat. The hot air over the ocean rises, creating a low-pressure area and a breeze from land to ocean while a large area of drying high pressure is formed over the land, increased by wintertime cooling.^[24] Monsoons resemble sea and land breezes, terms usually referring to the localized, diurnal (daily) cycle of circulation near coastlines everywhere, but they are much larger in scale - also stronger and seasonal.^[29]

Climatology

Mid-latitudes and subtropics

QuikSCAT image of typical extratropical cyclones over the ocean. Note the maximum winds are on the poleward side of the occluded front.

Large polar cyclones help determine the steering of systems moving through the mid-latitudes, south of the Arctic and north of the Antarctic. An index which is used to gauge the magnitude of this effect in the Northern Hemisphere is the Arctic oscillation.^[30] Extratropical cyclones tend to form east of climatological trough positions aloft near the east coast of continents, or west side of oceans.^[31] A study of extratropical cyclones in the Southern Hemisphere shows that between the 30th and 70th parallels, there are an average of 37 cyclones in existence during any 6-hour period.^[32] A separate study in the Northern Hemisphere suggests that approximately 234 significant extratropical cyclones form each winter.^[33] In Europe, particularly the United Kingdom, recurring extratropical low-pressure weather systems are typically known as depressions.^[34] These tend to bring wet weather throughout the year. Thermal lows also occur over continental areas across the subtropics during the summer such as the Sonoran Desert, the Mexican plateau, Sahara, South America, and Southeast Asia.^[23] The lows are most commonly located over the Tibetan plateau and in the lee of the Rocky mountains.^[31]

Monsoon trough

February position of the ITCZ and monsoon trough in the Pacific Ocean, depicted by area of convergent streamlines offshore Australia and in the equatorial eastern Pacific

Elongated areas of low pressure form at the monsoon trough or intertropical convergence zone as part of the Hadley cell circulation.^[35] Monsoon troughing in the western Pacific reaches its zenith in latitude during the late summer when the wintertime surface ridge in the opposite hemisphere is the strongest. It can reach as far as the 40th parallel in East Asia during August and 20th parallel in Australia during February. Its poleward progression is accelerated by the onset of the summer monsoon which is characterized by the development of lower air pressure over the warmest part of the various continents.^[36]^[37] The large-scale thermal lows over continents help create pressure gradients which drive monsoon circulations.^[38] In the southern hemisphere, the monsoon trough associated with the Australian monsoon reaches its most southerly latitude in February,^[39] oriented along a west-northwest/east-southeast axis. Many of the world's rainforests are associated with these climatological low-pressure systems.^[40]

Tropical cyclone

Infrared image of a powerful southern hemisphere cyclone, Winston, near its initial peak intensity

Tropical cyclones generally need to form more than 555 km (345 mi) or poleward of the 5th parallel north and 5th parallel south, allowing the Coriolis effect to deflect winds blowing towards the low-pressure center and creating a circulation.^[19] Worldwide, tropical cyclone activity peaks in late summer, when the difference between temperatures aloft and sea surface temperatures is the greatest. However, each particular basin has its own seasonal patterns. On a worldwide scale, May is the least active month while September is the most active month. November is the only month that activity in all the tropical cyclone basins is possible.^[41] Nearly one-third of the world's tropical cyclones form within the western Pacific Ocean, making it the most active tropical cyclone basin on Earth.^[42]

Associated weather

Schematic representation of flow around a low-pressure area in the Northern hemisphere. The pressure-gradient force is represented by blue arrows, the Coriolis acceleration (always perpendicular to the velocity) by red arrows

Wind is initially accelerated from areas of high pressure to areas of low pressure.^[43] This is due to density (or temperature and moisture) differences between two air masses. Since stronger high-pressure systems contain cooler or drier air, the air mass is denser and flows towards areas that are warm or moist, which are in the vicinity of low-pressure areas in advance of their associated cold fronts. The stronger the pressure difference, or pressure gradient, between a high-pressure system and a low-pressure system, the stronger the wind.^[44] Thus, stronger areas of low pressure are associated with stronger winds.

The Coriolis force caused by the Earth's rotation is what gives winds around low-pressure areas (such as in hurricanes, cyclones, and typhoons) their counter-clockwise (anticlockwise) circulation in the northern hemisphere (as the wind moves inward and is deflected right from the center of high pressure) and clockwise circulation in the southern hemisphere (as the wind moves inward and is deflected left from the center of high pressure).^[45] A cyclone differs from a hurricane or typhoon only on the basis of location.^[46] A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean, a typhoon occurs in the northwestern Pacific Ocean, and a cyclone occurs in the south Pacific or Indian Ocean.^[46] Friction with land slows down the wind flowing into low-pressure systems and causes wind to flow more inward, or flowing more ageostrophically, toward their centers.^[44] A low-pressure area is commonly associated with inclement weather,^[47] while a high-pressure area is associated with light winds and fair skies.^[48] Tornados are often too small, and of too short duration, to be influenced by the Coriolis force, but may be so-influenced when arising from a low-pressure system.^[49]^[50]

References

^ Arctic Climatology and Meteorology (2009). Cyclogenesis. Archived 2006-08-30 at the Wayback Machine. National Snow and Ice Data Center. Retrieved on 2009-02-21.
^ Glossary of Meteorology (2009). "Cyclogenesis". American Meteorological Society. Retrieved 2009-02-21.
^ Glossary of Meteorology (June 2000). "Cyclonic circulation". American Meteorological Society. Retrieved 2008-09-17.
^ Glossary of Meteorology (June 2000). "Cyclone". American Meteorological Society. Retrieved 2008-09-17.
^ BBC Weather Glossary (July 2006). "Cyclone". British Broadcasting Corporation. Archived from the original on 2006-08-29. Retrieved 2006-10-24.
^ "UCAR Glossary — Cyclone". meted.ucar.edu. Retrieved 2006-10-24.
^ Robert Hart (2003-02-18). "Cyclone Phase Analysis and Forecast: Help Page". Florida State University. Retrieved 2006-10-03.
^ I. Orlanski (1975). "A rational subdivision of scales for atmospheric processes". Bulletin of the American Meteorological Society. 56 (5): 527–530.
^ Glossary of Meteorology (June 2000). "Rossby wave". American Meteorological Society. Retrieved 2009-11-06.
^ Glossary of Meteorology (June 2000). "Short wave". American Meteorological Society. Retrieved 2009-11-06.
^ Glossary of Meteorology (June 2000). "Polar vortex". American Meteorological Society. Retrieved 2009-12-24.
^ Joel Norris (2005-03-19). "QG Notes" (PDF). University of California, San Diego. Retrieved 2009-10-26.
^ Glossary of Meteorology (2009). Short Wave. American Meteorological Society. Retrieved on 2009-03-02.
^ Glossary of Meteorology (2009). Upper-Level Trough. American Meteorological Society. Retrieved on 2009-03-02.
^ Carlyle H. Wash, Stacey H. Heikkinen, Chi-Sann Liou, and Wendell A. Nuss (1989). A Rapid Cyclogenesis Event during GALE IOP 9. Monthly Weather Review pp. 234–257. Retrieved on 2008-06-28.
^ Shay Johnson (2001-09-25). "The Norwegian Cyclone Model" (PDF). weather.ou.edu. Archived from the original (PDF) on 2006-09-01. Retrieved 2006-10-11.
^ E. A. Rasmussen & J. Turner (2003). Polar Lows: Mesoscale Weather Systems in the Polar Regions. Cambridge University Press. p. 612. ISBN 978-0-521-62430-5.
^ Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division (2004). "Frequently Asked Questions: What is an extra-tropical cyclone?". NOAA. Retrieved 2007-03-23.
^ ^a ^b ^c ^d ^e ^f Chris Landsea (2009-02-06). "Frequently Asked Questions: How do tropical cyclones form?". National Oceanic and Atmospheric Administration. Retrieved 2009-12-31.
^ Chris Landsea (2004-08-13). "Frequently Asked Questions: Why do tropical cyclones require 80 °F (27 °C) ocean temperatures to form?". National Oceanic and Atmospheric Administration. Retrieved 2006-07-25.
^ Glossary of Meteorology (2009). "Mesocyclone". American Meteorological Society. Retrieved 2006-12-07.
^ Choy, Barry K.; Scott M. Spratt (2003-05-13). "Using the WSR-88D to Predict East Central Florida Waterspouts". NOAA. Archived from the original on 2008-06-17. Retrieved 2009-12-26.
^ ^a ^b Glossary of Meteorology (2009). Thermal Low. American Meteorological Society. Retrieved on 2009-03-02.
^ ^a ^b Dr. Louisa Watts (2009). What causes the west African monsoon? National Centre for Environmental Science. Retrieved on 2009-04-04.
^ Dr. Michael Pidwirny (2008). CHAPTER 8: Introduction to the Hydrosphere (e). Cloud Formation Processes. Physical Geography. Retrieved on 2009-01-01.
^ Bart van den Hurk and Eleanor Blyth (2008). Global maps of Local Land-Atmosphere coupling. Archived 2009-02-25 at the Wayback Machine. KNMI. Retrieved on 2009-01-02.
^ Robert Penrose Pearce (2002). Meteorology at the Millennium. Academic Press, p. 66. ISBN 978-0-12-548035-2. Retrieved on 2009-01-02.
^ Glossary of Meteorology (June 2000). "Gust Front". American Meteorological Society. Retrieved 2008-07-09.
^ BBC Weather (2004-09-01). "The Asian Monsoon". Archived from the original on August 31, 2007. Retrieved 2008-05-22.
^ Todd Mitchell (2004). Arctic Oscillation (AO) time series, 1899 – June 2002. University of Washington. Retrieved on 2009-03-02.
^ ^a ^b L. de la Torre, Nieto R., Noguerol M., Añel J.A., Gimeno L. (2008). A climatology based on reanalysis of baroclinic developmental regions in the extratropical northern hemisphere. Ann New York Academy of Science;vol. 1146: pp. 235–255. Retrieved on 2009-03-02.
^ Ian Simmonds & Kevin Keay (February 2000). "Variability of Southern Hemisphere Extratropical Cyclone Behavior, 1958–97". Journal of Climate. American Meteorological Society. 13 (3): 550–561. Bibcode:2000JCli...13..550S. ISSN 1520-0442. doi:10.1175/1520-0442(2000)013<0550:VOSHEC>2.0.CO;2. Retrieved 2009-06-21.
^ S.K. Gulev; O. Zolina & S. Grigoriev (2001). "Winter Storms in the Northern Hemisphere (1958–1999) via the Internet Wayback Machine". Climate Dynamics. Science. 17: 795–809. Bibcode:2001ClDy...17..795G. doi:10.1007/s003820000145. Retrieved 2009-06-21.
^ Met Office (2009). Frontal Depressions. Retrieved on 2009-03-02.
^ Becca Hatheway (2008). "Hadley Cell". University Corporation for Atmospheric Research. Retrieved 2009-02-16.
^ National Centre for Medium Range Forecasting (2004-10-23). "Chapter-II Monsoon-2004: Onset, Advancement and Circulation Features" (PDF). Ministry of Earth Sciences (India). Archived from the original (PDF) on 2009-08-04. Retrieved 2008-05-03.
^ Australian Broadcasting Corporation (1999-08-11). "Monsoon". Retrieved 2008-05-03.
^ Mary E. Davis & Lonnie G. Thompson (2005). "Forcing of the Asian monsoon on the Tibetan Plateau: Evidence from high-resolution ice core and tropical coral records" (PDF). Journal of Geophysical Research. 110: 1 of 13. Bibcode:2005JGRD..11004101D. doi:10.1029/2004JD004933. ^{[permanent dead link]}
^ U. S. Navy (1998-01-22). "1.2 Pacific Ocean Surface Streamline Pattern". Retrieved 2006-11-26.
^ Hobgood (2008). "Global Pattern of Surface Pressure and Wind". Ohio State University. Archived from the original on 2009-03-18. Retrieved 2009-03-08.
^ Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division (2009-02-06). "Frequently Asked Questions: When is hurricane season?". National Oceanic and Atmospheric Administration. Retrieved 2009-12-24.
^ "Examining the ENSO" (PDF). James B Elsner, Kam-Biu Liu. 2003-10-08. Retrieved 2007-08-18.
^ BWEA (2007). Education and Careers: What is wind? Archived 2011-03-04 at the Wayback Machine. British Wind Energy Association. Retrieved on 2009-02-16.
^ ^a ^b JetStream (2008). Origin of Wind. National Weather Service Southern Region Headquarters. Retrieved on 2009-02-16.
^ Nelson, Stephen (Fall 2014). "Tropical Cyclones (Hurricanes)". Wind Systems: Low Pressure Centers. Tulane University. Retrieved 2016-12-24.
^ ^a ^b "What is the difference between a hurricane, a cyclone, and a typhoon?". OCEAN FACTS. National Ocean Service. Retrieved 2016-12-24.
^ Glossary of Meteorology (2009). Cyclone. American Meteorological Society. Retrieved on 2009-03-02.
^ Jack Williams (2007). What's happening inside highs and lows. USA Today. Retrieved on 2009-02-16.
^ Horton, Jennifer. "Does the rotation of the Earth affect toilets and baseball games?". SCIENCE, EVERYDAY MYTHS. HowStuffWorks. Retrieved 2016-12-25.
^ "Do Tornadoes Always Twist in the Same Direction?". SCIENCE — Earth and Space. WONDEROPOLIS. Retrieved 2016-12-25.

UpToDate Contents

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English Journal

Impact of dietary cadmium sulphide nanoparticles on Danio rerio zebrafish at very low contamination pressure.

Ladhar C1, Geffroy B, Cambier S, Treguer-Delapierre M, Durand E, Brèthes D, Bourdineaud JP.Author information 1University of Bordeaux, CNRS, UMR 5805, Arcachon Marine Station , Place du Dr Peyneau, 33120 Arcachon , France.AbstractTo address the impact of cadmium sulphide nanoparticles (CdSNPs) of two different sizes (8 and 50 nm), Danio rerio zebrafish were dietary exposed to very low doses: 100 or 40 ng CdSNPs/day/g body weight for 36 or 60 days, respectively. The results obtained using RAPD-PCR genotoxicity test showed genomic alteration since the number of hybridisation sites of the RAPD probes was significantly modified after CdSNPs exposure. In addition, selected stress response genes were either repressed or upregulated in tissues of CdSNPs-exposed fish. Mitochondrial dysfunction was also caused by the presence of CdSNPs in food. Cadmium accumulation in fish tissues (brain and muscles) could only be observed after 60 days of exposure. CdSNPs toxicity was dependent on their size and concentration.
Nanotoxicology.Nanotoxicology.2014 Sep;8(6):676-85. doi: 10.3109/17435390.2013.822116. Epub 2013 Jul 25.
To address the impact of cadmium sulphide nanoparticles (CdSNPs) of two different sizes (8 and 50 nm), Danio rerio zebrafish were dietary exposed to very low doses: 100 or 40 ng CdSNPs/day/g body weight for 36 or 60 days, respectively. The results obtained using RAPD-PCR genotoxicity test showed gen
PMID 23883150

Osteocytes exposed to far field of therapeutic ultrasound promotes osteogenic cellular activities in pre-osteoblasts through soluble factors.

Fung CH1, Cheung WH2, Pounder NM3, Harrison A3, Leung KS4.Author information 1Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.2Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, China; Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China. Electronic address: louis@ort.cuhk.edu.hk.3Orthopaedic Trauma and Clinical Therapies, Smith and Nephew, Inc., Durham, NC 27703, United States.4Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong, China; Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China.AbstractLow intensity pulsed ultrasound (LIPUS) was reported to accelerate the rate of fracture healing. When LIPUS is applied to fractures transcutaneously, bone tissues at different depths are exposed to different ultrasound fields. Measurement of LIPUS shows pressure variations in near field (nearby transducer); uniform profile was found beyond it (far field). Moreover, we have reported that the therapeutic effect of LIPUS is dependent on the axial distance of ultrasound beam in rat fracture model. However, the mechanisms of how different axial distances of LIPUS influence the mechanotransduction of bone cells are not understood. To understand the cellular mechanisms underlying far field LIPUS on enhanced fracture healing in rat model, the present study investigated the effect of ultrasound axial distances on (1) osteocyte, the mechanosensor, and (2) mechanotransduction between osteocyte and pre-osteoblast (bone-forming cell) through paracrine signaling. We hypothesized that far field LIPUS could enhance the osteogenic activities of osteoblasts via paracrine factors secreted from osteocytes. The objective of this study was to investigate the effect of axial distances of LIPUS on osteocytes and osteocyte-osteoblast mechanotransduction. In this study, LIPUS (plane; 2.2cm in diameter, 1.5MHz sine wave, ISATA=30mW/cm(2)) was applied to osteocytes (mechanosensor) at three axial distances: 0mm (near field), 60mm (mid-near field) and 130mm (far field). The conditioned medium of osteocytes (OCM) collected from these three groups were used to culture pre-osteoblasts (effector cell). In this study, (1) the direct effect of ultrasound fields on the mechanosensitivity of osteocytes; and (2) the osteogenic effect of different OCM treatments on pre-osteoblasts were assessed. The immunostaining results indicated the ultrasound beam at far field resulted in more β-catenin nuclear translocation in osteocytes than all other groups. This indicated that osteocytes could detect the acoustic differences of LIPUS at various axial distances. Furthermore, we found that the soluble factors secreted by far field LIPUS exposed osteocytes could further promote pre-osteoblasts cell migration, maturation (transition of cell proliferation into osteogenic differentiation), and matrix calcification. In summary, our results of this present study indicated that axial distance beyond near field could transmit ultrasound energy to osteocyte more efficiently. The LIPUS exposed osteocytes conveyed mechanical signals to pre-osteoblasts and regulated their osteogenic cellular activities via paracrine factors secretion. The soluble factors secreted by far field exposed osteocytes led to promotion in migration and maturation in pre-osteoblasts. This finding demonstrated the positive effects of far field LIPUS on stimulating osteocytes and promoting mechanotransduction between osteocytes and osteoblasts.
Ultrasonics.Ultrasonics.2014 Jul;54(5):1358-65. doi: 10.1016/j.ultras.2014.02.003. Epub 2014 Feb 11.
Low intensity pulsed ultrasound (LIPUS) was reported to accelerate the rate of fracture healing. When LIPUS is applied to fractures transcutaneously, bone tissues at different depths are exposed to different ultrasound fields. Measurement of LIPUS shows pressure variations in near field (nearby tran
PMID 24560187

Stimulation of bone repair with ultrasound: A review of the possible mechanic effects.

Padilla F1, Puts R2, Vico L3, Raum K2.Author information 1Inserm, U1032, LabTau, Lyon F-69003, France; Université de Lyon, Lyon F-69003, France. Electronic address: frederic.padilla@inserm.fr.2Julius Wolff Institut & Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Germany.3Inserm U1059 Lab Biologie intégrée du Tissu Osseux, Université de Lyon, St-Etienne F-42023, France.AbstractIn vivo and in vitro studies have demonstrated the positive role that ultrasound can play in the enhancement of fracture healing or in the reactivation of a failed healing process. We review the several options available for the use of ultrasound in this context, either to induce a direct physical effect (LIPUS, shock waves), to deliver bioactive molecules such as growth factors, or to transfect cells with osteogenic plasmids; with a main focus on LIPUS (or Low Intensity Pulsed Ultrasound) as it is the most widespread and studied technique. The biological response to LIPUS is complex as numerous cell types respond to this stimulus involving several pathways. Known to-date mechanotransduction pathways involved in cell responses include MAPK and other kinases signaling pathways, gap-junctional intercellular communication, up-regulation and clustering of integrins, involvement of the COX-2/PGE2, iNOS/NO pathways and activation of ATI mechanoreceptor. The mechanisms by which ultrasound can trigger these effects remain intriguing. Possible mechanisms include direct and indirect mechanical effects like acoustic radiation force, acoustic streaming, and propagation of surface waves, fluid-flow induced circulation and redistribution of nutrients, oxygen and signaling molecules. Effects caused by the transformation of acoustic wave energy into heat can usually be neglected, but heating of the transducer may have a potential impact on the stimulation in some in-vitro systems, depending on the coupling conditions. Cavitation cannot occur at the pressure levels delivered by LIPUS. In-vitro studies, although not appropriate to identify the overall biological effects, are of great interest to study specific mechanisms of action. The diversity of current experimental set-ups however renders this analysis very complex, as phenomena such as transducer heating, inhomogeneities of the sound intensity in the near field, resonances in the transmission and reflection through the culture dish walls and the formation of standing waves will greatly affect the local type and amplitude of the stimulus exerted on the cells. A future engineering challenge is therefore the design of dedicated experimental set-ups, in which the different mechanical phenomena induced by ultrasound can be controlled. This is a prerequisite to evaluate the biological effects of the different phenomena with respect to particular parameters, like intensity, frequency, or duty cycle. By relating the variations of these parameters to the induced physical effects and to the biological responses, it will become possible to derive an 'acoustic dose' and propose a quantification and cross-calibration of the different experimental systems. Improvements in bone healing management will probably also come from a combination of ultrasound with a 'biologic' components, e.g. growth factors, scaffolds, gene therapies, or drug delivery vehicles, the effects of which being potentiated by the ultrasound.
Ultrasonics.Ultrasonics.2014 Jul;54(5):1125-45. doi: 10.1016/j.ultras.2014.01.004. Epub 2014 Jan 17.
In vivo and in vitro studies have demonstrated the positive role that ultrasound can play in the enhancement of fracture healing or in the reactivation of a failed healing process. We review the several options available for the use of ultrasound in this context, either to induce a direct physical e
PMID 24507669

Japanese Journal

Improved Deposition Efficiency of Cold-Sprayed CoNiCrAlY with Pure Ni Coatings and Its High-Temperature Oxidation Behavior after Pre-Treatment in Low Oxygen Partial Pressure

Lee Kang-Il,Ogawa Kazuhiro
Materials transactions 55(9), 1434-1439, 2014-09
NAID 40020178526

Changes in hydrophobic and hydrophilic hydration properties caused by raising the pressure or by lowering the temperature

Kinoshita Masahiro,Oshima Hiraku
Chemical Physics Letters 610-611, 1-7, 2014-08-28
… The entropic component, which always makes a positive contribution to the HFE, becomes larger at high pressures and smaller at low temperatures for both solutes: it governs the pressure and temperature dependence of the HFE. … For hydrophilic solutes at low temperatures, however, the energetic component becomes more important and makes them less hydrophilic. … We discuss the validity of our previous studies on pressure and cold denaturating of proteins. …
NAID 120005466700

Fabrication of mixed α/β-SiAlON powders via salt-assisted combustion synthesis

Niu Jing,Harada Kazuto,Suzuki Shota,Nakatsugawa Isao,Okinaka Noriyuki,Akiyama Tomohiro
Journal of Alloys and Compounds 604, 260-265, 2014-08-15
… High-quality Y-and Ca-α/β-SiAlON and α-SiAlON ceramics were synthesized via salt-assisted combustion synthesis from Si, Al, and metal oxide (Y2O3 and CaO) with the addition of NaCl and MgCl2 under a nitrogen pressure of 1 MPa. … We found that the type of metal chlorides employed significantly affected the α/β ratio and the morphology of the product, with the use of NaCl affording high α/β ratios and equiaxed morphologies, while the use of MgCl2 resulting in low α/β ratios and elongated grains. …
NAID 120005464717

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★リンクテーブル★

リンク元	「hypotonia」「低圧」「hypobaric」「低圧力」
拡張検索	「low-pressure」
関連記事	「low」「pressure」

「hypotonia」

　　[★]

n.

筋緊張低下、低張、低血圧、低圧

関: decreased muscle tone、hypobaric、low pressure、low-pressure、muscle hypotonia、muscular flaccidity、muscular hypotonia

「低圧」

　　[★]

英: low pressure、hypotonia、low-pressure、hypobaric
関: 減圧、低比重、低圧力、筋緊張低下、筋弛緩状態

「hypobaric」

　　[★]

減圧の、低圧の、低比重の

関: hypotonia、low density、low pressure、low-pressure、reduced pressure、vacuum

「低圧力」

　　[★]

英: low pressure、low-pressure
関: 低圧

「low-pressure」

　　[★]

低圧の、低圧力の

関: hypobaric、hypotonia、low pressure

「low」

　　[★]

adj.

(比較級lower-最上級lowest)低い、不十分な

関: deficient、inadequate、insufficiency、insufficient、insufficiently、poorly、scanty

「pressure」

　　[★]

n.

圧力

[1] Arctic Climatology and Meteorology (2009). Cyclogenesis. Archived 2006-08-30 at the Wayback Machine. National Snow and Ice Data Center. Retrieved on 2009-02-21.

[CyclogenesisDef-2] Glossary of Meteorology (2009). "Cyclogenesis". American Meteorological Society. Retrieved 2009-02-21.

[AMSCcDef-3] Glossary of Meteorology (June 2000). "Cyclonic circulation". American Meteorological Society. Retrieved 2008-09-17.

[AMSCycDef-4] Glossary of Meteorology (June 2000). "Cyclone". American Meteorological Society. Retrieved 2008-09-17.

[BBCCycDef-5] BBC Weather Glossary (July 2006). "Cyclone". British Broadcasting Corporation. Archived from the original on 2006-08-29. Retrieved 2006-10-24.

[UCARCycDef-6] "UCAR Glossary — Cyclone". meted.ucar.edu. Retrieved 2006-10-24.

[AnlFcastHelp-7] Robert Hart (2003-02-18). "Cyclone Phase Analysis and Forecast: Help Page". Florida State University. Retrieved 2006-10-03.

[8] I. Orlanski (1975). "A rational subdivision of scales for atmospheric processes". Bulletin of the American Meteorological Society. 56 (5): 527–530.

[9] Glossary of Meteorology (June 2000). "Rossby wave". American Meteorological Society. Retrieved 2009-11-06.

[10] Glossary of Meteorology (June 2000). "Short wave". American Meteorological Society. Retrieved 2009-11-06.

[11] Glossary of Meteorology (June 2000). "Polar vortex". American Meteorological Society. Retrieved 2009-12-24.

[12] Joel Norris (2005-03-19). "QG Notes" (PDF). University of California, San Diego. Retrieved 2009-10-26.

[13] Glossary of Meteorology (2009). Short Wave. American Meteorological Society. Retrieved on 2009-03-02.

[14] Glossary of Meteorology (2009). Upper-Level Trough. American Meteorological Society. Retrieved on 2009-03-02.

[15] Carlyle H. Wash, Stacey H. Heikkinen, Chi-Sann Liou, and Wendell A. Nuss (1989). A Rapid Cyclogenesis Event during GALE IOP 9. Monthly Weather Review pp. 234–257. Retrieved on 2008-06-28.

[NorCycMod-16] Shay Johnson (2001-09-25). "The Norwegian Cyclone Model" (PDF). weather.ou.edu. Archived from the original (PDF) on 2006-09-01. Retrieved 2006-10-11.

[17] E. A. Rasmussen & J. Turner (2003). Polar Lows: Mesoscale Weather Systems in the Polar Regions. Cambridge University Press. p. 612. ISBN 978-0-521-62430-5.

[AOML_FAQ_A7-18] Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division (2004). "Frequently Asked Questions: What is an extra-tropical cyclone?". NOAA. Retrieved 2007-03-23.

[AOML_FAQ_A15-19] ^ ^a ^b ^c ^d ^e ^f Chris Landsea (2009-02-06). "Frequently Asked Questions: How do tropical cyclones form?". National Oceanic and Atmospheric Administration. Retrieved 2009-12-31.

[AOML_FAQ_A16-20] Chris Landsea (2004-08-13). "Frequently Asked Questions: Why do tropical cyclones require 80 °F (27 °C) ocean temperatures to form?". National Oceanic and Atmospheric Administration. Retrieved 2006-07-25.

[MesocyloneDef-21] Glossary of Meteorology (2009). "Mesocyclone". American Meteorological Society. Retrieved 2006-12-07.

[22] Choy, Barry K.; Scott M. Spratt (2003-05-13). "Using the WSR-88D to Predict East Central Florida Waterspouts". NOAA. Archived from the original on 2008-06-17. Retrieved 2009-12-26.

[thermal-23] Glossary of Meteorology (2009). Thermal Low. American Meteorological Society. Retrieved on 2009-03-02.

[cause-24] Dr. Louisa Watts (2009). What causes the west African monsoon? National Centre for Environmental Science. Retrieved on 2009-04-04.

[MT-25] Dr. Michael Pidwirny (2008). CHAPTER 8: Introduction to the Hydrosphere (e). Cloud Formation Processes. Physical Geography. Retrieved on 2009-01-01.

[26] Bart van den Hurk and Eleanor Blyth (2008). Global maps of Local Land-Atmosphere coupling. Archived 2009-02-25 at the Wayback Machine. KNMI. Retrieved on 2009-01-02.

[27] Robert Penrose Pearce (2002). Meteorology at the Millennium. Academic Press, p. 66. ISBN 978-0-12-548035-2. Retrieved on 2009-01-02.

[28] Glossary of Meteorology (June 2000). "Gust Front". American Meteorological Society. Retrieved 2008-07-09.

[29] BBC Weather (2004-09-01). "The Asian Monsoon". Archived from the original on August 31, 2007. Retrieved 2008-05-22.

[30] Todd Mitchell (2004). Arctic Oscillation (AO) time series, 1899 – June 2002. University of Washington. Retrieved on 2009-03-02.

[extra-31] L. de la Torre, Nieto R., Noguerol M., Añel J.A., Gimeno L. (2008). A climatology based on reanalysis of baroclinic developmental regions in the extratropical northern hemisphere. Ann New York Academy of Science;vol. 1146: pp. 235–255. Retrieved on 2009-03-02.

[VarSouthCyc-32] Ian Simmonds & Kevin Keay (February 2000). "Variability of Southern Hemisphere Extratropical Cyclone Behavior, 1958–97". Journal of Climate. American Meteorological Society. 13 (3): 550–561. Bibcode:2000JCli...13..550S. ISSN 1520-0442. doi:10.1175/1520-0442(2000)013<0550:VOSHEC>2.0.CO;2. Retrieved 2009-06-21.

[WinterStormsNorth-33] S.K. Gulev; O. Zolina & S. Grigoriev (2001). "Winter Storms in the Northern Hemisphere (1958–1999) via the Internet Wayback Machine". Climate Dynamics. Science. 17: 795–809. Bibcode:2001ClDy...17..795G. doi:10.1007/s003820000145. Retrieved 2009-06-21.

[34] Met Office (2009). Frontal Depressions. Retrieved on 2009-03-02.

[35] Becca Hatheway (2008). "Hadley Cell". University Corporation for Atmospheric Research. Retrieved 2009-02-16.

[NCFMRF-36] National Centre for Medium Range Forecasting (2004-10-23). "Chapter-II Monsoon-2004: Onset, Advancement and Circulation Features" (PDF). Ministry of Earth Sciences (India). Archived from the original (PDF) on 2009-08-04. Retrieved 2008-05-03.

[37] Australian Broadcasting Corporation (1999-08-11). "Monsoon". Retrieved 2008-05-03.

[38] Mary E. Davis & Lonnie G. Thompson (2005). "Forcing of the Asian monsoon on the Tibetan Plateau: Evidence from high-resolution ice core and tropical coral records" (PDF). Journal of Geophysical Research. 110: 1 of 13. Bibcode:2005JGRD..11004101D. doi:10.1029/2004JD004933. ^{[permanent dead link]}

[NAVY2-39] U. S. Navy (1998-01-22). "1.2 Pacific Ocean Surface Streamline Pattern". Retrieved 2006-11-26.

[40] Hobgood (2008). "Global Pattern of Surface Pressure and Wind". Ohio State University. Archived from the original on 2009-03-18. Retrieved 2009-03-08.

[AOML_FAQ_G1-41] Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division (2009-02-06). "Frequently Asked Questions: When is hurricane season?". National Oceanic and Atmospheric Administration. Retrieved 2009-12-24.

[enso-42] "Examining the ENSO" (PDF). James B Elsner, Kam-Biu Liu. 2003-10-08. Retrieved 2007-08-18.

[43] BWEA (2007). Education and Careers: What is wind? Archived 2011-03-04 at the Wayback Machine. British Wind Energy Association. Retrieved on 2009-02-16.

[jet-44] JetStream (2008). Origin of Wind. National Weather Service Southern Region Headquarters. Retrieved on 2009-02-16.

[45] Nelson, Stephen (Fall 2014). "Tropical Cyclones (Hurricanes)". Wind Systems: Low Pressure Centers. Tulane University. Retrieved 2016-12-24.

[HCT-46] "What is the difference between a hurricane, a cyclone, and a typhoon?". OCEAN FACTS. National Ocean Service. Retrieved 2016-12-24.

[47] Glossary of Meteorology (2009). Cyclone. American Meteorological Society. Retrieved on 2009-03-02.

[48] Jack Williams (2007). What's happening inside highs and lows. USA Today. Retrieved on 2009-02-16.

[49] Horton, Jennifer. "Does the rotation of the Earth affect toilets and baseball games?". SCIENCE, EVERYDAY MYTHS. HowStuffWorks. Retrieved 2016-12-25.

[50] "Do Tornadoes Always Twist in the Same Direction?". SCIENCE — Earth and Space. WONDEROPOLIS. Retrieved 2016-12-25.

v t e Cyclones and anticyclones of the world (Centers of action)
Types	Extratropical Mesocyclone/Anticyclonic storm Polar Subtropical cyclone/Subtropical ridge Thermal Tropical
Anticyclones	Polar High Siberian High Azores High (Bermuda/North Atlantic) North American High (Canadian/Greenland) South Atlantic High (St.Helena) North Pacific High (Hawaii High) South Pacific High Kalahari High
Cyclones	Aleutian Low (Alaska/Far East Russia) Atlantic hurricane Australian Low (east coast) European windstorm Genoa Low Icelandic Low Kona storm (Hawaii) Nor'easter Pacific hurricane Polar vortex Typhoon Wake Low

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案内

low pressure