WordNet

plan secretly, usually something illegal; "They plotted the overthrow of the government"
a small area of ground covered by specific vegetation; "a bean plot"; "a cabbage patch"; "a briar patch" (同)plot of land, plot of ground, patch
a secret scheme to do something (especially something underhand or illegal); "they concocted a plot to discredit the governor"; "I saw through his little game from the start" (同)secret plan, game
a chart or map showing the movements or progress of an object
the story that is told in a novel or play or movie etc.; "the characters were well drawn but the plot was banal"
devise the sequence of events in (a literary work or a play, movie, or ballet); "the writer is plotting a new novel"
form into a hill
a local and well-defined elevation of the land; "they loved to roam the hills of West Virginia"
risque English comedian (1925-1992) (同)Benny Hill, Alfred Hawthorne
United States railroad tycoon (1838-1916) (同)J. J. Hill, James Jerome Hill

PrepTutorEJDIC

『小区画の土地』,小地所 / (小説・劇などの)『筋』,プロット / 『蔭謀』,たくらみ / 〈悪事〉‘を'『ひそかに計画する』,たくらむ / (地図・海図などに)…‘を'書き込む;…‘の'図表(図面)を作る / 〈土地〉‘を'区画する《+『out』+『名,』+『名』+『out』》 / (…に対して…の)『陰謀を企てる』,たくらむ《+『against』+『名』+『about』(『toward』)+『名』(do『ing』)
『丘』,小山 / (特に道路の)傾斜,坂 / 盛り上げた土砂,塚

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/01/12 13:38:01」(JST)

wiki en

[Wiki en表示]

This article is about The Hill equation is an equation used in biochemical characterization. For other uses, see Hill differential equation.

In biochemistry, the binding of a ligand to a macromolecule is often enhanced if there are already other ligands present on the same macromolecule (this is known as Cooperative binding). The Hill coefficient provides a way to quantify this effect.

It describes the fraction of the macromolecule saturated by ligand as a function of the ligand concentration; it is used in determining the degree of cooperativeness of the ligand binding to the enzyme or receptor. It was originally formulated by Archibald Hill in 1910 to describe the sigmoidal O₂ binding curve of hemoglobin.^[1]

A coefficient of 1 indicates completely independent binding, regardless of how many additional ligands are already bound. Numbers greater than one indicate positive cooperativity, while numbers less than one indicate negative cooperativity. The Hill coefficient of oxygen binding to hemoglobin is 2.3-3.0.

Hill equation:

- fraction of occupied sites where the ligand can bind to the binding site of the receptor protein.

- free (unbound) ligand concentration

- Apparent dissociation constant derived from the law of mass action (equilibrium constant for dissociation)

- ligand concentration producing half occupation (ligand concentration occupying half of the binding sites). This is also the microscopic dissociation constant.

- Hill coefficient, describing cooperativity (or possibly other biochemical properties, depending on the context in which the Hill equation is being used)

Taking the reciprocal of both sides, rearranging, inverting again, and then taking the logarithm on both sides of the equation leads to an alternative formulation of the Hill equation:

When appropriate, the value of the Hill coefficient describes the cooperativity of ligand binding in the following way:

- Positively cooperative binding: Once one ligand molecule is bound to the enzyme, its affinity for other ligand molecules increases.

- Negatively cooperative binding: Once one ligand molecule is bound to the enzyme, its affinity for other ligand molecules decreases.

- Noncooperative binding: The affinity of the enzyme for a ligand molecule is not dependent on whether or not other ligand molecules are already bound. In this case, the Hill equation (as a relationship between the concentration of a compound adsorbing to binding sites and the fractional occupancy of the binding sites) is equivalent to the Langmuir equation.

References[edit]

^ Hill, A. V. (1910-01-22). "The possible effects of the aggregation of the molecules of hæmoglobin on its dissociation curves" (PDF). J. Physiol. 40 (Suppl): iv–vii. Retrieved 2009-03-18.

Dorland's Illustrated Medical Dictionary
Nelson, David L.; Cox, Michael M. Lehninger Principles of Biochemistry (4th ed.).
Coval ML (December 1970). "Analysis of Hill interaction coefficients and the invalidity of the Kwon and Brown equation". J. Biol. Chem. 245 (23): 6335–6. PMID 5484812. Cite uses deprecated parameters (help)
d'A Heck, Henry (1971). "Statistical theory of cooperative binding to proteins. Hill equation and the binding potential". J. Am. Chem. Soc. 93 (1): 23–29. doi:10.1021/ja00730a004.
Atkins, Gordon L. (1973). "A simple digital-computer program for estimating the parameter of the Hill Equation". Eur. J. Biochem. 33 (1): 175–180. doi:10.1111/j.1432-1033.1973.tb02667.x.
Endrenyi, Laszlo; Kwong, F. H. F.; Fajszi, Csaba (1975). "Evaluation of Hill slopes and Hill coefficients when the saturation binding or velocity is not known". Eur. J. Biochem. 51 (2): 317–328. doi:10.1111/j.1432-1033.1975.tb03931.x.
Voet, Donald; Voet, Judith G. Biochemistry.
Weiss, J. N. (1997). "The Hill equation revisited: uses and misuses". FASEB 11 (11): 835–841. PMID 9285481.
Kurganov, B. I.; Lobanov, A. V. (2001). "Criterion for Hill equation validity for description of biosensor calibration curves". Anal. Chimica Acta 427 (1): 11–19. doi:10.1016/S0003-2670(00)01167-3.
Goutelle1, Sylvain; Maurin, Michel; Rougier, Florent; Barbaut, Xavier; Bourguignon, Laurent; Ducher, Michel; Maire, Pascal (2008). "The Hill equation: a review of its capabilities in pharmacological modelling". Fund. Clinic. Pharmac. 22: 633–648. doi:10.1111/j.1472-8206.2008.00633.x.
Mitavskiy, B.; Chu, D.; Zabet., Radu (2009). "Models of transcription factor binding: Sensitivity of activation functions to model assumptions.". Journal of Theoretical Biology 257 (3): 419–429. doi:10.1016/j.jtbi.2008.11.026. PMID 19121637.
Gesztelyi R; Zsuga J; Kemeny-Beke A; Varga B; Juhasz B; Tosaki A (2012). "The Hill equation and the origin of quantitative pharmacology". Arch Hist Exact Sci 66: 427–38.
Colquhoun D (2006). "The quantitative analysis of drug-receptor interactions: a short history". Trends Pharmacol Sci 27: 149–57.
Rang HP (2006). "The receptor concept: pharmacology's big idea". Br J Pharmacol 147: S9–16.
Neubig RR; Spedding M; Kenakin T; Christopoulos A (2003). "International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification. XXXVIII. update on terms and symbols in quantitative pharmacology". Pharmacol Rev 55: 597–606.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. システマティックレビューおよびメタアナリシス systematic review and meta analysis
2. 肩関節脱臼および整復 shoulder dislocation and reduction
3. 生物統計学および疫学に関する一般用語集 glossary of common biostatistical and epidemiological terms
4. 成人における胃食道逆流の外科的マネージメント surgical management of gastroesophageal reflux in adults
5. 多発血管炎性肉芽腫症および顕微鏡的多発血管炎を伴う肉芽腫症の臨床症状および診断 clinical manifestations and diagnosis of granulomatosis with polyangiitis and microscopic polyangiitis

English Journal

Cation export by overland flow in a recently burnt forest area in north-central Portugal.

Machado AI1, Serpa D2, Ferreira RV1, Rodríguez-Blanco ML3, Pinto R1, Nunes MI1, Cerqueira MA1, Keizer JJ1.
The Science of the total environment.Sci Total Environ.2015 Aug 15;524-525:201-12. doi: 10.1016/j.scitotenv.2015.04.026. Epub 2015 Apr 17.
The current fire regime in the Mediterranean Basin constitutes a serious threat to natural ecosystems because it drastically enhances surface runoff and soil erosion in the affected areas. Besides soil particles themselves, soil cations can be lost by fire-enhanced overland flow, increasing the risk
PMID 25897728

Predictive factors for limb occlusions after endovascular aneurysm repair.

Faure EM1, Becquemin JP2, Cochennec F2; ENGAGE collaborators.
Journal of vascular surgery.J Vasc Surg.2015 May;61(5):1138-1145.e2. doi: 10.1016/j.jvs.2014.11.084. Epub 2015 Feb 2.
OBJECTIVE: Greater flexibility and smaller sizes for introducer sheaths in the newest stent grafts increase the feasibility of endovascular aneurysm repair but raise concerns about long-term limb patency. The aim of the study was to determine the incidence of and predictive factors for limb occlusio
PMID 25656594

Using theory and formative research to design interventions to improve community health worker motivation, retention and performance in Mozambique and Uganda.

Strachan DL1, Källander K2,3, Nakirunda M4, Ndima S5, Muiambo A6, Hill Z7; inSCALE study group.
Human resources for health.Hum Resour Health.2015 Apr 30;13:25. doi: 10.1186/s12960-015-0020-8.
BACKGROUND: Community health workers (CHWs) are increasingly being used in low-income countries to address human resources shortages, yet there remain few effective, evidence-based strategies for addressing the enduring programmatic constraints of worker motivation, retention and performance. This p
PMID 25925007

Japanese Journal

Topographic variation in heterotrophic and autotrophic soil respiration in a tropical seasonal forest in Thailand(Environment)

TAKAHASHI Masamichi,HIRAI Keizo,LIMTONG Pitayakon,LEAUNGVUTIVIROG Chaveevan,PANUTHAI Samreong,SUKSAWANG Songtam,ANUSONTPORNPERM Somchai,MAROD Dokrak
Soil science and plant nutrition 57(3), 452-465, 2011-06
… In Kanchanaburi, western Thailand, we measured the soil respiration rates at different slope positions-ridge (plot R), upper slope (plot U), and lower slope (plot L)-on a hill in a seasonal tropical forest [mixed deciduous forest (MDF)] to determine the seasonal and spatial variations in soil respiration on the slope. …
NAID 110009327333

登熟期の水稲穂部への海水由来塩分付着害に対するケイ酸による減収の軽減効果

森静香,柴田康志,松田裕之,藤井弘志
日本土壌肥料學雜誌 80(4), 347-354, 2009-08-05
登熟期の水稲穂部に塩分付着害を人為的に発生させ,海水由来塩分付着害に対するケイ酸の幼形期前後の追肥による減収の軽減効果を検討した結果は以下のとおりである.1)2005年は出穂前10日,2006年は出穂前29日のケイ酸処理により,海水散布前のケイ酸吸収量は両年次ともに対照区よりケイ酸処理区で多い傾向であった.2)海水を1株当たり5mL散布した各試験区の一穂塩分量は2005年の海水を散布した全区におい …
NAID 110007504041