প্রতিপ্রভা: সংশোধিত সংস্করণের মধ্যে পার্থক্য

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বট নিবন্ধ পরিষ্কার করেছে। কোন সমস্য থাকল এর পরিচালককে জানান।
৪ নং লাইন:
 
{{distinguish|Inflorescence}}
{{forজন্য|the album by Asobi Seksu|Fluorescence (album)}}
{{Use dmy dates|date=July 2012}}
[[Image:Fluorescent minerals hg.jpg|thumb|right|Fluorescent minerals emit visible light when exposed to [[ultraviolet]] light.]]
১৭ নং লাইন:
[[File:Lignum nephriticum - cup of Philippine lignum nephriticum, Pterocarpus indicus, and flask containing its fluorescent solution Hi.jpg|thumb|left|upright|''[[Lignum nephriticum]]'' cup made from the wood of the narra tree (''[[Pterocarpus indicus]]''), and a flask containing its fluorescent [[Solution (chemistry)|solution]]]]
[[File:Matlaline structure.svg|thumb|right|Matlaline, the fluorescent substance in the wood of the tree ''Eysenhardtia polystachya'']]
An early observation of fluorescence was described in 1560 by [[Bernardino de Sahagún]] and in 1565 by [[Nicolás Monardes]] in the [[infusion]] known as ''[[lignum nephriticum]]'' ([[Latin]] for "kidney wood"). It was derived from the wood of two tree species, ''[[Pterocarpus indicus]]'' and ''[[Eysenhardtia polystachya]]''.<ref name="acuna">{{Citeসাময়িকী journalউদ্ধৃতি | last1 = Acuña | first1 = A. Ulises | last2 = Amat-Guerri | first2 = Francisco | last3 = Morcillo | first3 = Purificación | last4 = Liras | first4 = Marta | last5 = Rodríguez | first5 = Benjamín | title = Structure and Formation of the Fluorescent Compound of ''Lignum nephriticum'' | doi = 10.1021/ol901022g | journal = Organic Letters | volume = 11 | issue = 14 | pages = 3020–3023 | year = 2009 | pmid = 19586062 | url = http://202.127.145.151/siocl/siocl_0001/HHJdatabank/090707ol-6.pdf | deadurl = no | archiveurl = https://web.archive.org/web/20130728224629/http://202.127.145.151/siocl/siocl_0001/HHJdatabank/090707ol-6.pdf | archivedate = 28 July 2013 | df = dmy-all }}</ref><ref name="saff">{{citeবই bookউদ্ধৃতি|author= [[William Edwin Safford|Safford, William Edwin]]|title =Annual report of the Board of Regents of the Smithsonian Institution|chapter =''Lignum nephriticum''|location=Washington|publisher =Government Printing Office|date =1916|pages=271–298|url =https://archive.org/download/annualreportofbo1915smitfo/annualreportofbo1915smitfo.pdf}}</ref><ref>{{Citeসাময়িকী journalউদ্ধৃতি | last1 = Valeur | first1 = B. | last2 = Berberan-Santos | first2 = M. R. N. | doi = 10.1021/ed100182h | title = A Brief History of Fluorescence and Phosphorescence before the Emergence of Quantum Theory | journal = Journal of Chemical Education | volume = 88 | issue = 6 | pages = 731–738 | year = 2011 | pmid = | pmc = |bibcode = 2011JChEd..88..731V }}</ref><ref>{{Citeসাময়িকী journalউদ্ধৃতি | last1 = Muyskens | first1 = M. | doi = 10.1021/ed083p765 | last2 = Ed Vitz | title = The Fluorescence of ''Lignum nephriticum'': A Flash Back to the Past and a Simple Demonstration of Natural Substance Fluorescence | journal = Journal of Chemical Education | volume = 83 | issue = 5 | pages = 765 | year = 2006 | pmid = | pmc = |bibcode = 2006JChEd..83..765M }}</ref> The chemical compound responsible for this fluorescence is matlaline, which is the oxidation product of one of the flavonoids found in this wood.<ref name="acuna"/>
 
In 1819, [[Edward Daniel Clarke|Edward D. Clarke]]<ref>{{citeসাময়িকী journalউদ্ধৃতি|author=Clarke, Edward Daniel|year=1819|url=https://books.google.com/books?id=KWc7AQAAIAAJ&pg=PA34|title=Account of a newly discovered variety of green fluor spar, of very uncommon beauty, and with remarkable properties of colour and phosphorescence|journal=The Annals of Philosophy|volume=14|pages=34–36|quote=The finer crystals are perfectly transparent. Their colour by transmitted light is an intense ''emerald green''; but by reflected light, the colour is a deep ''sapphire blue''|deadurl=no|archiveurl=https://web.archive.org/web/20170117092607/https://books.google.com/books?id=KWc7AQAAIAAJ&pg=PA34|archivedate=17 January 2017|df=dmy-all}}</ref> and in 1822 [[René Just Haüy]]<ref>Haüy merely repeats Clarke's observation regarding the colors of the specimen of fluorite which he (Clarke) had examined: Haüy, ''Traité de Minéralogie'', 2nd ed. (Paris, France: Bachelier and Huzard, 1822), vol. 1, [https://books.google.com/books?id=MvcTAAAAQAAJ&pg=PA512 p. 512] {{webarchive|url=https://web.archive.org/web/20170117122039/https://books.google.com/books?id=MvcTAAAAQAAJ&pg=PA512 |date=17 January 2017 }}. Fluorite is called "chaux fluatée" by Haüy: "... violette par réflection, et verdâtre par transparence au Derbyshire." ([the color of fluorite is] violet by reflection, and greenish by transmission in [specimens from] Derbyshire.)</ref> described fluorescence in [[fluorite]]s, [[Sir David Brewster]] described the phenomenon for [[chlorophyll]] in 1833<ref>{{citeসাময়িকী journalউদ্ধৃতি|author=Brewster, David|year=1834|url=https://books.google.com/books?id=I_UQAAAAIAAJ&pg=PA538|title=On the colours of natural bodies|journal=Transactions of the Royal Society of Edinburgh|volume=12|issue=2|pages=538–545|doi=10.1017/s0080456800031203|deadurl=no|archiveurl=https://web.archive.org/web/20170117120622/https://books.google.com/books?id=I_UQAAAAIAAJ&pg=PA538|archivedate=17 January 2017|df=dmy-all}} On page 542, Brewster mentions that when white light passes through an alcoholic solution of chlorophyll, red light is reflected from it.</ref> and [[Sir John Herschel]] did the same for [[quinine]] in 1845.<ref>{{citeসাময়িকী journalউদ্ধৃতি|author=Herschel, John|year=1845|url=https://books.google.com/books?id=GmwOAAAAIAAJ&pg=PA143|title=On a case of superficial colour presented by a homogeneous liquid internally colourless|journal=Philosophical Transactions of the Royal Society of London|volume=135|pages=143–145|doi=10.1098/rstl.1845.0004|deadurl=no|archiveurl=https://web.archive.org/web/20161224220539/https://books.google.com/books?id=GmwOAAAAIAAJ&pg=PA143|archivedate=24 December 2016|df=dmy-all}}</ref><ref>{{citeসাময়িকী journalউদ্ধৃতি|author=Herschel, John|year=1845|url=https://books.google.com/books?id=GmwOAAAAIAAJ&pg=PA147|title=On the epipŏlic dispersion of light, being a supplement to a paper entitled, "On a case of superficial colour presented by a homogeneous liquid internally colourless"|journal=Philosophical Transactions of the Royal Society of London|volume=135|pages=147–153|doi=10.1098/rstl.1845.0005|deadurl=no|archiveurl=https://web.archive.org/web/20170117093409/https://books.google.com/books?id=GmwOAAAAIAAJ&pg=PA147|archivedate=17 January 2017|df=dmy-all}}</ref>
 
In his 1852 paper on the "Refrangibility" ([[wavelength]] change) of light, [[George Gabriel Stokes]] described the ability of [[fluorite|fluorspar]] and [[uranium glass]] to change invisible light beyond the violet end of the visible spectrum into blue light. He named this phenomenon ''fluorescence'' : "I am almost inclined to coin a word, and call the appearance ''fluorescence'', from fluor-spar [i.e., fluorite], as the analogous term ''opalescence'' is derived from the name of a mineral."<ref>{{citeসাময়িকী journalউদ্ধৃতি
|title = On the Change of Refrangibility of Light
|author = Stokes, G. G.
৯৯ নং লাইন:
 
===Fluorence===
Strongly fluorescent pigments often have an unusual appearance which is often described colloquially as a "neon color." This phenomenon was termed "Farbenglut" by [[Hermann von Helmholtz]] and "fluorence" by Ralph M. Evans. It is generally thought to be related to the high brightness of the color relative to what it would be as a component of white. Fluorescence shifts energy in the incident illumination from shorter wavelengths to longer (such as blue to yellow) and thus can make the fluorescent color appear brighter (more saturated) than it could possibly be by reflection alone.<ref>{{citeসাময়িকী journalউদ্ধৃতি|last1=Schieber|first1=Frank|title=Modeling the Appearance of Fluorescent Colors|journal=Proceedings of the Human Factors and Ergonomics Society Annual Meeting|date=October 2001|volume=45|issue=18|pages=1324–1327|doi=10.1177/154193120104501802}}</ref>
 
==Rules==
১১১ নং লাইন:
 
===Stokes shift===
{{mainমূল articleনিবন্ধ|Stokes shift}}
In general, emitted fluorescent light has a longer wavelength and lower energy than the absorbed light.<ref>[[#Lakowicz|Lakowicz]], pp. 6–7</ref> This phenomenon, known as [[Stokes shift]], is due to energy loss between the time a photon is absorbed and when it is emitted. The causes and magnitude of Stokes shift can be complex and are dependent on the fluorophore and its environment. However, there are some common causes. It is frequently due to non-radiative decay to the lowest vibrational energy level of the excited state. Another factor is that the emission of fluorescence frequently leaves a fluorophore in a higher vibrational level of the ground state.
 
১২০ নং লাইন:
 
====Biofluorescence====
Biofluorescence is the absorption of [[electromagnetic radiation|electromagnetic]] wavelengths from the [[visible light]] spectrum by fluorescent proteins in a living organism, and the reemission of that light at a lower energy level. This causes the light that is re-emitted to be a different color than the light that is absorbed. Stimulating light excites an [[electron]], raising energy to an unstable level. This instability is unfavorable, so the energized electron is returned to a stable state almost as immediately as it becomes unstable. This return to stability corresponds with the release of excess energy in the form of fluorescent light. This emission of light is only observable when the stimulant light is still providing light to the organism/object and is typically yellow, pink, orange, red, green, or purple. Biofluorescence is often confused with the following forms of biotic light, bioluminescence and biophosphorescence.<ref name="Fluorescence in marine organisms">{{citeওয়েব webউদ্ধৃতি|title=Fluorescence in marine organisms|url=http://gestaltswitchexpeditions.com/fluorescence-in-marine-orga/|website=Gestalt Switch Expeditions|deadurl=yes|archiveurl=https://web.archive.org/web/20150221070425/http://www.gestaltswitchexpeditions.com/fluorescence-in-marine-orga/|archivedate=21 February 2015|df=dmy-all}}</ref>
 
====Bioluminescence====
১৩১ নং লাইন:
 
====Epidermal chromatophores====
Pigment cells that exhibit fluorescence are called fluorescent chromatophores, and function somatically similar to regular [[chromatophore]]s. These cells are dendritic, and contain pigments called fluorosomes. These pigments contain fluorescent proteins which are activated by K+ (potassium) ions, and it is their movement, aggregation, and dispersion within the fluorescent chromatophore that cause directed fluorescence patterning.<ref name="wucherer" /><ref>{{Citeসাময়িকী journalউদ্ধৃতি
| pmid = 11041206
| year = 2000
১৪৪ নং লাইন:
}}</ref> Fluorescent cells are innervated the same as other chromatphores, like melanophores, pigment cells that contain [[melanin]]. Short term fluorescent patterning and signaling is controlled by the nervous system.<ref name ="wucherer" /> Fluorescent chromatophores can be found in the skin (e.g. in fish) just below the epidermis, amongst other chromatophores.
 
Epidermal fluorescent cells in fish also respond to hormonal stimuli by the α–MSH and MCH hormones much the same as melanophores. This suggests that fluorescent cells may have color changes throughout the day that coincide with their [[circadian rhythm]].<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1093/icb/13.3.885| title = Endocrine Regulation of Pigmentation in Fish| journal = Integrative and Comparative Biology| volume = 13| issue = 3| pages = 885–894| year = 1973| last1 = Abbott | first1 = F. S. }}</ref> Fish may also be sensitive to [[cortisol]] induced [[stress response]]s to environmental stimuli, such as interaction with a predator or engaging in a mating ritual.<ref name="wucherer" />
 
===Phylogenetics===
 
====Evolutionary origins====
It is suspected by some scientists that [[Green fluorescent protein|GFPs]] and GFP like proteins began as electron donors activated by light. These electrons were then used for reactions requiring light energy. Functions of fluorescent proteins, such as protection from the sun, conversion of light into different wavelengths, or for signaling are thought to have evolved secondarily.<ref name="Biology of underwater fluorescence">{{citeওয়েব webউদ্ধৃতি|last1=Beyer|first1=Steffen|title=Biology of underwater fluorescence|url=https://translate.google.com/translate?sl=de&tl=en&prev=_t&hl=en&ie=UTF-8&u=http://www.fluopedia.org/publications/deutsch/biologie/|website=Fluopedia.org}}</ref>
 
[[File:Observed occurrences of green and red biofluorescence in Actinopterygii - journal.pone.0083259.g002.png|thumb|Observed occurrences of green and red biofluorescence in Actinopterygii – journal.pone.0083259.g002|thumb|Fluorescence has multiple origins in the tree of life. This diagram displays the origins within actinopterygians (ray finned fish).]]
 
The incidence of fluorescence across the [[tree of life]] is widespread, and has been studied most extensively in a phylogenetic sense in fish. The phenomenon appears to have evolved multiple times in multiple [[tax]]a such as in the anguilliformes (eels), gobioidei (gobies and cardinalfishes), and tetradontiformes (triggerfishes), along with the other taxa discussed later in the article. Fluorescence is highly genotypically and phenotypically variable even within ecosystems, in regards to the wavelengths emitted, the patterns displayed, and the intensity of the fluorescence. Generally, the species relying upon camouflage exhibit the greatest diversity in fluorescence, likely because camouflage is one of the most common uses of fluorescence.<ref name="sparks">{{Citeসাময়িকী journalউদ্ধৃতি | last1 = Sparks | first1 = J. S. | last2 = Schelly | first2 = R. C. | last3 = Smith | first3 = W. L. | last4 = Davis | first4 = M. P. | last5 = Tchernov | first5 = D. | last6 = Pieribone | first6 = V. A. | last7 = Gruber | first7 = D. F. | editor1-last = Fontaneto | editor1-first = Diego | title = The Covert World of Fish Biofluorescence: A Phylogenetically Widespread and Phenotypically Variable Phenomenon | doi = 10.1371/journal.pone.0083259 | journal = PLoS ONE | volume = 9 | issue = 1 | pages = e83259 | year = 2014 | pmid = 24421880| pmc = 3885428|bibcode = 2014PLoSO...983259S }}</ref>
 
====Adaptive functions====
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Water absorbs light of long wavelengths, so less light from these wavelengths reflects back to reach the eye. Therefore, warm colors from the visual light spectrum appear less vibrant at increasing depths. Water scatters light of shorter wavelengths, meaning cooler colors dominate the visual field in the [[photic zone]]. Light intensity decreases 10 fold with every 75 m of depth, so at depths of 75 m, light is 10% as intense as it is on the surface, and is only 1% as intense at 150 m as it is on the surface. Because the water filters out the wavelengths and intensity of water reaching certain depths, different proteins, because of the wavelengths and intensities of light they are capable of absorbing, are better suited to different depths. Theoretically, some fish eyes can detect light as deep as 1000 m. At these depths of the aphotic zone, the only sources of light are organisms themselves, giving off light through chemical reactions in a process called bioluminescence.
 
Fluorescence is simply defined as the absorption of electromagnetic radiation at one [[wavelength]] and its reemission at another, lower energy wavelength.<ref name="sparks" /> Thus any type of fluorescence depends on the presence of external sources of light. Biologically functional fluorescence is found in the photic zone, where there is not only enough light to cause biofluorescence, but enough light for other organisms to detect it. The visual field in the photic zone is naturally blue, so colors of fluorescence can be detected as bright reds, oranges, yellows, and greens. Green is the most commonly found color in the biofluorescent spectrum, yellow the second most, orange the third, and red is the rarest. Fluorescence can occur in organisms in the aphotic zone as a byproduct of that same organism’s bioluminescence. Some biofluorescence in the aphotic zone is merely a byproduct of the organism’s tissue biochemistry and does not have a functional purpose. However, some cases of functional and adaptive significance of biofluorescence in the aphotic zone of the deep ocean is an active area of research.<ref>{{citeওয়েব webউদ্ধৃতি|last1=Matz|first1=M.|title=Fluorescence: The Secret Color of the Deep|url=http://oceanexplorer.noaa.gov/explorations/05deepscope/background/fluorescence/fluorescence.html|publisher=Office of Ocean Exploration and Research, U.S. National Oceanic and Atmospheric Administration|deadurl=no|archiveurl=https://web.archive.org/web/20141031213647/http://oceanexplorer.noaa.gov/explorations/05deepscope/background/fluorescence/fluorescence.html|archivedate=31 October 2014|df=dmy-all}}</ref>
 
====[[Photic zone]]====
১৬৯ নং লাইন:
Bony fishes living in shallow water, due to living in a colorful environment, generally have good color vision. Thus, in shallow-water fishes, red, orange, and green fluorescence most likely serves as a means of communication with conspecifics, especially given the great phenotypic variance of the phenomenon.<ref name="sparks"/>
 
Many fish that exhibit biofluorescence, such as [[sharks]], [[lizardfish]], [[scorpionfish]], [[wrasses]], and [[flatfishes]], also possess yellow intraocular filters.<ref name="Heinermann">{{citeসাময়িকী journalউদ্ধৃতি|last1=Heinermann|first1=P|title=Yellow intraocular filters in fishes|journal=Experimental Biology|date=2014-03-10|volume=43|issue=2|pages=127–147|pmid=6398222}}</ref> Yellow intraocular filters in the [[lens (anatomy)|lenses]] and [[cornea]] of certain fishes function as long-pass filters, thus enabling the species that possess them to visualize and potentially exploit fluorescence to enhance visual contrast and patterns that are unseen to other fishes and predators that lack this visual specialization.<ref name="sparks"/> Fishes that possess the necessary yellow intraocular filters for visualizing biofluorescence potentially exploit a light signal from members of it or a similar functional role. Biofluorescent patterning was especially prominent in cryptically patterned fishes possessing complex camouflage, and that many of these lineages also possess yellow long-pass intraocular filters that could enable visualization of such patterns.<ref name="Heinermann" />
 
Another adaptive use of fluorescence is to generate red light from the ambient blue light of the [[photic zone]] to aid vision. Red light can only be seen across short distances due to attenuation of red light wavelengths by water.<ref name="michiels">{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1186/1472-6785-8-16| pmid = 18796150| pmc = 2567963| title = Red fluorescence in reef fish: A novel signalling mechanism?| journal = BMC Ecology| volume = 8| pages = 16| year = 2008| last1 = Michiels | first1 = N. K. | last2 = Anthes | first2 = N. | last3 = Hart | first3 = N. S. | last4 = Herler | first4 = J. R. | last5 = Meixner | first5 = A. J. | last6 = Schleifenbaum | first6 = F. | last7 = Schulte | first7 = G. | last8 = Siebeck | first8 = U. E. | last9 = Sprenger | first9 = D. | last10 = Wucherer | first10 = M. F. }}</ref> Many fish species that fluoresce are small, group-living, or benthic/aphotic, and have conspicuous patterning. This patterning is caused by fluorescent tissue and is visible to other members of the species, however the patterning is invisible at other visual spectra. These intraspecific fluorescent patterns also coincide with intra-species signaling. The patterns present in ocular rings to indicate directionality of an individual’s gaze, and along fins to indicate directionality of an individual’s movement.<ref name="michiels" /> Current research suspects that this red fluorescence is used for private communication between members of the same species.<ref name="wucherer">{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1371/journal.pone.0037913| pmid = 22701587| title = A Fluorescent Chromatophore Changes the Level of Fluorescence in a Reef Fish| journal = PLoS ONE| volume = 7| issue = 6| pages = e37913| year = 2012| last1 = Wucherer | first1 = M. F. | last2 = Michiels | first2 = N. K. |bibcode = 2012PLoSO...737913W | pmc=3368913}}</ref><ref name= "sparks" /><ref name ="michiels" /> Due to the prominence of blue light at ocean depths, red light and light of longer wavelengths are muddled, and many predatory reef fish have little to no sensitivity for light at these wavelengths. Fish such as the fairy wrasse that have developed visual sensitivity to longer wavelengths are able to display red fluorescent signals that give a high contrast to the blue environment and are conspicuous to conspecifics in short ranges, yet are relatively invisible to other common fish that have reduced sensitivities to long wavelengths. Thus, fluorescence can be used as adaptive signaling and intra-species communication in reef fish.<ref name="michiels" /><ref name="gerlach">{{Citeসাময়িকী journalউদ্ধৃতি
| pmid = 24870049
| pmc = 4071555
১৯২ নং লাইন:
 
=====Coral=====
Fluorescence serves a wide variety of functions in coral. Fluorescent proteins in corals may contribute to photosynthesis by converting otherwise unusable wavelengths of light into ones for which the coral’s symbiotic algae are able to conduct [[photosynthesis]].<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1038/35048564 | pmid = 11130722 | title = Fluorescent pigments in corals are photoprotective | year = 2000 | last1 = Salih | first1 = A. | journal = Nature | volume = 408 | issue = 6814 | pages = 850–3 | last2 = Larkum | first2 = A. | last3 = Cox | first3 = G. | last4 = Kühl | first4 = M. | last5 = Hoegh-Guldberg | first5 = O. | url = https://www.researchgate.net/publication/12197663_Fluorescent_pigments_in_corals_are_photoprotective | bibcode = 2000Natur.408..850S | deadurl = no | archiveurl = https://web.archive.org/web/20151222103614/https://www.researchgate.net/publication/12197663_Fluorescent_Pigments_in_Corals_are_Photoprotective | archivedate = 22 December 2015 | df = dmy-all }}</ref> Also, the proteins may fluctuate in number as more or less light becomes available as a means of photoacclimation.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1242/jeb.040881| title = Green fluorescent protein regulation in the coral Acropora yongei during photoacclimation| journal = Journal of Experimental Biology| volume = 213| issue = 21| pages = 3644–3655| year = 2010| last1 = Roth | first1 = M. S.| last2 = Latz | first2 = M. I.| last3 = Goericke | first3 = R.| last4 = Deheyn | first4 = D. D. | pmid=20952612}}</ref> Similarly, these fluorescent proteins may possess antioxidant capacities to eliminate oxygen radicals produced by photosynthesis.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1016/j.bbagen.2006.08.014| title = Quenching of superoxide radicals by green fluorescent protein| journal = Biochimica et Biophysica Acta (BBA) - General Subjects| volume = 1760| issue = 11| pages = 1690–1695| year = 2006| last1 = Bou-Abdallah | first1 = F. | last2 = Chasteen | first2 = N. D. | last3 = Lesser | first3 = M. P. | pmid=17023114 | pmc=1764454}}</ref> Finally, through modulating photosynthesis, the fluorescent proteins may also serve as a means of regulating the activity of the coral’s photosynthetic algal symbionts.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1007/s00239-005-0129-9| title = Adaptive Evolution of Multicolored Fluorescent Proteins in Reef-Building Corals| journal = Journal of Molecular Evolution| volume = 62| issue = 3| pages = 332–339| year = 2006| last1 = Field | first1 = S. F. | last2 = Bulina | first2 = M. Y. | last3 = Kelmanson | first3 = I. V. | last4 = Bielawski | first4 = J. P. | last5 = Matz | first5 = M. V. | pmid=16474984| bibcode = 2006JMolE..62..332F}}</ref>
 
=====[[Cephalopods]]=====
''Alloteuthis subulata'' and ''Loligo vulgaris'', two types of nearly transparent squid, have fluorescent spots above their eyes. These spots reflect incident light, which may serve as a means of camouflage, but also for signaling to other squids for schooling purposes.<ref>{{Citeসাময়িকী journalউদ্ধৃতি
|pmid = 11441052
|url = http://jeb.biologists.org/content/204/12/2103.short
২১৮ নং লাইন:
[[File:Crystal Jelly ("Aequorea Victoria"), Monterey Bay Aquarium, Monterey, California, USA.jpg|thumb|DSC26479, Crystal Jelly ("Aequorea Victoria"), Monterey Bay Aquarium, Monterey, California, USA (5085398602)|thumb|''Aequoria victoria'', biofluorescent jellyfish known for GFP]]
 
Another, well-studied example of biofluorescence in the ocean is the [[hydrozoan]] ''[[Aequorea victoria]]''. This jellyfish lives in the photic zone off the west coast of North America and was identified as a carrier of [[green fluorescent protein]] (GFP) by [[Osamu Shimomura]]. The gene for these green fluorescent proteins has been isolated and is scientifically significant because it is widely used in genetic studies to indicate the expression of other genes.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1146/annurev.biochem.67.1.509| title = The Green Fluorescent Protein| journal = Annual Review of Biochemistry| volume = 67| pages = 509–544| year = 1998| last1 = Tsien | first1 = R. Y.| pmid=9759496}}</ref>
 
=====Mantis shrimp=====
Several species of [[mantis shrimp]], which are stomatopod [[crustaceans]], including ''Lysiosquillina glabriuscula'', have yellow fluorescent markings along their antennal scales and [[carapace]] (shell) that males present during threat displays to predators and other males. The display involves raising the head and thorax, spreading the striking appendages and other maxillipeds, and extending the prominent, oval antennal scales laterally, which makes the animal appear larger and accentuates its yellow fluorescent markings. Furthermore, as depth increases, mantis shrimp fluorescence accounts for a greater part of the visible light available. During mating rituals, mantis shrimp actively fluoresce, and the wavelength of this fluorescence matches the wavelengths detected by their eye pigments.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1126/science.1089803| title = Fluorescent Enhancement of Signaling in a Mantis Shrimp| journal = Science| volume = 303| issue = 5654| pages = 51| year = 2004| last1 = Mazel | first1 = C. H.| pmid=14615546}}</ref>
 
====[[Aphotic zone]]====
 
=====Siphonophores=====
''[[Siphonophorae]]'' is an order of marine animals from the phylum [[Hydrozoa]] that consist of a specialized [[jellyfish|medusoid]] and [[polyp]] [[zooid]]. Some siphonophores, including the genus Erenna that live in the aphotic zone between depths of 1600 m and 2300 m, exhibit yellow to red fluorescence in the [[photophores]] of their tentacle-like [[tentilla]]. This fluorescence occurs as a by-product of bioluminescence from these same photophores. The siphonophores exhibit the fluorescence in a flicking pattern that is used as a lure to attract prey.<ref>{{Citeসাময়িকী journalউদ্ধৃতি
| doi = 10.1016/j.bbagen.2006.08.014
| title = Quenching of superoxide radicals by green fluorescent protein
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=====Dragonfish=====
The predatory deep-sea [[Barbeled dragonfish|dragonfish]] ''Malacosteus niger'', the closely related ''Aristostomias'' genus and the species ''Pachystomias microdon'' are capable of harnessing the blue light emitted from their own bioluminescence to generate red biofluorescence from suborbital [[photophores]]. This red fluorescence is invisible to other animals, which allows these dragonfish extra light at dark ocean depths without attracting or signaling predators.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1038/30871|title=Dragon fish see using chlorophyll|bibcode=1998Natur.393..423D| year = 1998| last1 = Douglas | first1 = R. H.| journal = Nature| volume = 393| issue = 6684| pages = 423–424| last2 = Partridge | first2 = J. C.| last3 = Dulai | first3 = K.| last4 = Hunt | first4 = D.| last5 = Mullineaux | first5 = C. W.| last6 = Tauber | first6 = A. Y.| last7 = Hynninen | first7 = P. H.}}</ref>
 
===Terrestrial biofluorescence===
 
====Amphibians====
The [[Polka-dot tree frog]], widely found in the [[Amazon rainforest|Amazon]] was discovered to be the first fluorescent [[amphibian]] in 2017. The frog is pale green with dots in white, yellow or light red. The fluorescence of the frog was discovered unintentionally in Buenos Aires, Argentina. The fluorescence was traced to a new compound found in the [[lymph]] and skin glads.<ref>{{citeসংবাদ newsউদ্ধৃতি |last=Wong |first=Sam |date=March 13, 2017 |title=Luminous frog is the first known naturally fluorescent amphibian |url=https://www.newscientist.com/article/2124466-luminous-frog-is-the-first-known-naturally-fluorescent-amphibian/ |access-date=2017-03-22 |deadurl=no |archiveurl=https://web.archive.org/web/20170320143233/https://www.newscientist.com/article/2124466-luminous-frog-is-the-first-known-naturally-fluorescent-amphibian/ |archivedate=20 March 2017 |df=dmy-all }}</ref> The main fluorescent compound is Hyloin-L1 and it gives a blue-green glow when exposed to violet or [[Ultraviolet|ultra violet light]]. Scientists behind the discovery say that the fluorescence can be used for communication. They also think that about 100 or 200 species of frogs are likely to be fluorescent.<ref>{{citeসংবাদ newsউদ্ধৃতি |last=King |first=Anthony |date=March 13, 2017 |title=Fluorescent frog first down to new molecule |url=https://www.chemistryworld.com/news/fluorescent-frog-first-down-to-new-molecule-/2500541.article |access-date=2017-03-22 |deadurl=no |archiveurl=https://web.archive.org/web/20170322191916/https://www.chemistryworld.com/news/fluorescent-frog-first-down-to-new-molecule-/2500541.article |archivedate=22 March 2017 |df=dmy-all }}</ref>
 
====Butterflies====
[[swallowtail butterfly|Swallowtail]] (''Papilio'') butterflies have complex systems for emitting fluorescent light. Their wings contain pigment-infused crystals that provide directed fluorescent light. These crystals function to produce fluorescent light best when they absorb [[radiance]] from sky-blue light (wavelength about 420&nbsp;nm). The wavelengths of light that the butterflies see the best correspond to the absorbance of the crystals in the butterfly's wings. This likely functions to enhance the capacity for signaling.<ref>{{Citeসাময়িকী journalউদ্ধৃতি
| pmid = 16293753
| year = 2005
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====Parrots====
[[Parrots]] have fluorescent [[plumage]] that may be used in mate signaling. A study using mate-choice experiments on [[budgerigars]] (''Melopsittacus undulates'') found compelling support for fluorescent sexual signaling, with both males and females significantly preferring birds with the fluorescent experimental stimulus. This study suggests that the fluorescent plumage of parrots is not simply a by-product of [[pigmentation]], but instead an adapted sexual signal. Considering the intricacies of the pathways that produce fluorescent pigments, there may be significant costs involved. Therefore, individuals exhibiting strong fluorescence may be honest indicators of high individual quality, since they can deal with the associated costs.<ref>{{Citeসাময়িকী journalউদ্ধৃতি| doi = 10.1126/science.295.5552.92| pmid = 11778040| title = Fluorescent Signaling in Parrots| journal = Science| volume = 295| issue = 5552| pages = 92| year = 2002| last1 = Arnold| first1 = K. E.| url = http://www.stat.ufl.edu/STA6166/Fall2007/STA}}{{dead link|date=January 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
 
====Arachnids====
[[File:Sorpion Under Blacklight edit.jpg|thumb|Fluorescing scorpion]]
Spiders fluoresce under UV light and possess a huge diversity of fluorophores. Remarkably, spiders are the only known group in which fluorescence is “taxonomically widespread, variably expressed, evolutionarily labile, and probably under selection and potentially of ecological importance for intraspecific and interspecific signaling.” A study by Andrews et al. (2007) reveals that fluorescence has evolved multiple times across spider taxa, with novel fluorophores evolving during spider diversification. In some spiders, ultraviolet cues are important for predator-prey interactions, intraspecific communication, and camouflaging with matching fluorescent flowers. Differing ecological contexts could favor inhibition or enhancement of fluorescence expression, depending upon whether fluorescence helps spiders be cryptic or makes them more conspicuous to predators. Therefore, natural selection could be acting on expression of fluorescence across spider species.<ref>{{Citeসাময়িকী journalউদ্ধৃতি
| pmid = 17412670
| pmc = 2104643
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}}</ref>
 
Scorpions also fluoresce.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1016/S1074-5521(99)80085-4| title = The fluorescence of scorpions and cataractogenesis| journal = Chemistry & Biology| volume = 6| issue = 8| pages = 531–539| year = 1999| last1 = Stachel | first1 = S. J. | last2 = Stockwell | first2 = S. A. | last3 = Van Vranken | first3 = D. L. | pmid=10421760}}</ref>
 
====Plants====
The ''Mirabilis jalapa'' flower contains violet, fluorescent betacyanins and yellow, fluorescent betaxanthins. Under white light, parts of the flower containing only betaxanthins appear yellow, but in areas where both betaxanthins and betacyanins are present, the visible fluorescence of the flower is faded due to internal light-filtering mechanisms. Fluorescence was previously suggested to play a role in [[pollinator]] attraction, however, it was later found that the visual signal by fluorescence is negligible compared to the visual signal of light reflected by the flower.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1007/s00114-010-0709-4| title = Is the flower fluorescence relevant in biocommunication?| journal = Naturwissenschaften| volume = 97| issue = 10| pages = 915–924| year = 2010| last1 = Iriel | first1 = A. A. | last2 = Lagorio | first2 = M. A. G. |bibcode = 2010NW.....97..915I | pmid=20811871}}</ref>
 
[[Chlorophyll]] fluoresces a weak red under ultraviolet light.<ref>{{Citeবই bookউদ্ধৃতি|url=https://books.google.com/books?id=x2PZRC6Zd5sC&pg=PA12&dq=Chlorophyll+fluoresces+a+weak+red+under+ultraviolet+light.&hl=en&sa=X&ved=0ahUKEwiRlYCz85vYAhWJgVQKHZhsDrYQ6AEIODAD#v=onepage&q=Chlorophyll%20fluoresces%20a%20weak%20red%20under%20ultraviolet%20light.&f=false|title=Photobiology of Higher Plants|last=McDonald|first=Maurice S.|date=2003-06-02|publisher=John Wiley & Sons|isbn=9780470855232|language=en|deadurl=no|archiveurl=https://web.archive.org/web/20171221200631/https://books.google.com/books?id=x2PZRC6Zd5sC&pg=PA12&dq=Chlorophyll+fluoresces+a+weak+red+under+ultraviolet+light.&hl=en&sa=X&ved=0ahUKEwiRlYCz85vYAhWJgVQKHZhsDrYQ6AEIODAD#v=onepage&q=Chlorophyll%20fluoresces%20a%20weak%20red%20under%20ultraviolet%20light.&f=false|archivedate=21 December 2017|df=dmy-all}}</ref>
 
===Abiotic fluorescence===
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====Atmosphere====
Fluorescence is observed in the atmosphere when the air is under energetic electron bombardment. In cases such as the natural [[aurora]], high-altitude nuclear explosions, and rocket-borne electron gun experiments, the molecules and ions formed have a fluorescent response to light.<ref name=gilmore1992>
{{Citeসাময়িকী journalউদ্ধৃতি| doi = 10.1063/1.555910| title = Franck–Condon Factors, r-Centroids, Electronic Transition Moments, and Einstein Coefficients for Many Nitrogen and Oxygen Band Systems| journal = Journal of Physical and Chemical Reference Data| volume = 21| issue = 5| pages = 1005| year = 1992| last1 = Gilmore| first1 = F. R.| last2 = Laher| first2 = R. R.| last3 = Espy| first3 = P. J.| bibcode = 1992JPCRD..21.1005G| url = http://www.dtic.mil/docs/citations/ADA246065| deadurl = no| archiveurl = https://web.archive.org/web/20170709141516/http://www.dtic.mil/docs/citations/ADA246065| archivedate = 9 July 2017| df = dmy-all}}</ref>
 
====Common materials that fluoresce====
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===Lighting===
{{detailsবিস্তারিত|Fluorescent lamp}}
[[Image:Www Beo cc.jpg|thumb|Fluorescent paint and plastic lit by [[UV tube]]s. Paintings by Beo Beyond]]
The common [[fluorescent lamp]] relies on fluorescence. Inside the [[glass]] tube is a partial vacuum and a small amount of [[mercury (element)|mercury]]. An electric discharge in the tube causes the mercury atoms to emit mostly ultraviolet light. The tube is lined with a coating of a fluorescent material, called the ''[[phosphor]]'', which absorbs the ultraviolet and re-emits visible light. Fluorescent [[lighting]] is more energy-efficient than [[incandescent]] lighting elements. However, the uneven [[spectrum]] of traditional fluorescent lamps may cause certain colors to appear different than when illuminated by incandescent light or [[daylight]]. The mercury vapor emission spectrum is dominated by a short-wave UV line at 254&nbsp;nm (which provides most of the energy to the phosphors), accompanied by visible light emission at 436&nbsp;nm (blue), 546&nbsp;nm (green) and 579&nbsp;nm (yellow-orange). These three lines can be observed superimposed on the white continuum using a hand spectroscope, for light emitted by the usual white fluorescent tubes. These same visible lines, accompanied by the emission lines of trivalent europium and trivalent terbium, and further accompanied by the emission continuum of divalent europium in the blue region, comprise the more discontinuous light emission of the modern trichromatic phosphor systems used in many [[compact fluorescent lamp]] and traditional lamps where better color rendition is a goal.<ref name="How Fluorescent Lamps Work">{{citeওয়েব webউদ্ধৃতি|last=Harris|first=Tom|title=How Fluorescent Lamps Work|url=http://home.howstuffworks.com/fluorescent-lamp.htm|work=HowStuffWorks|publisher=Discovery Communications|accessdate=27 June 2010|deadurl=no|archiveurl=https://web.archive.org/web/20100706040948/http://home.howstuffworks.com/fluorescent-lamp.htm|archivedate=6 July 2010|df=dmy-all}}</ref>
 
Fluorescent lights were first available to the public at the [[1939 New York World's Fair]]. Improvements since then have largely been better phosphors, longer life, and more consistent internal discharge, and easier-to-use shapes (such as compact fluorescent lamps). Some [[High-intensity discharge lamp|high-intensity discharge (HID) lamps]] couple their even-greater electrical efficiency with phosphor enhancement for better color rendition.{{Citation needed|date=July 2010}}
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===Analytical chemistry===
Many analytical procedures involve the use of a [[fluorometer]], usually with a single exciting wavelength and single detection wavelength. Because of the sensitivity that the method affords, fluorescent molecule concentrations as low as 1 part per trillion can be measured.<ref>{{Citeসাময়িকী journalউদ্ধৃতি | doi = 10.1006/abio.1993.1020| title = Fluorometric Assay Using Dimeric Dyes for Double- and Single-Stranded DNA and RNA with Picogram Sensitivity| journal = Analytical Biochemistry| volume = 208| pages = 144–150| year = 1993| last1 = Rye | first1 = H. S. | last2 = Dabora | first2 = J. M. | last3 = Quesada | first3 = M. A. | last4 = Mathies | first4 = R. A. | last5 = Glazer | first5 = A. N. | pmid=7679561}}</ref>
 
Fluorescence in several wavelengths can be detected by an [[Chromatography detector|array detector]], to detect compounds from [[High-performance liquid chromatography|HPLC]] flow. Also, [[Thin layer chromatography|TLC]] plates can be visualized if the compounds or a coloring reagent is fluorescent. Fluorescence is most effective when there is a larger ratio of atoms at lower energy levels in a [[Boltzmann distribution]]. There is, then, a higher probability of excitement and release of photons by lower-energy atoms, making analysis more efficient.
 
===Spectroscopy===
{{Mainমূল articleনিবন্ধ|Fluorescence spectroscopy}}
Usually the setup of a fluorescence assay involves a light source, which may emit many different wavelengths of light. In general, a single wavelength is required for proper analysis, so, in order to selectively filter the light, it is passed through an excitation monochromator, and then that chosen wavelength is passed through the sample cell. After absorption and re-emission of the energy, many wavelengths may emerge due to [[Stokes shift]] and various [[electron transition]]s. To separate and analyze them, the fluorescent radiation is passed through an emission [[monochromator]], and observed selectively by a detector.<ref>{{citeবই bookউদ্ধৃতি|author=Harris, Daniel C.|title=Exploring chemical analysis|url=https://books.google.com/books?id=x5eEW76lizEC|date=2004|publisher=Macmillan|isbn=978-0-7167-0571-0|deadurl=no|archiveurl=https://web.archive.org/web/20160731220213/https://books.google.com/books?id=x5eEW76lizEC|archivedate=31 July 2016|df=dmy-all}}</ref>
 
===Biochemistry and medicine===
{{Mainমূল articleনিবন্ধ|Fluorescence in the life sciences}}
[[Image:FluorescentCells.jpg|thumb|right|[[Endothelium|Endothelial cells]] under the microscope with three separate channels marking specific cellular components]]
Fluorescence in the life sciences is used generally as a non-destructive way of tracking or analysis of biological molecules by means of the fluorescent emission at a specific frequency where there is no background from the excitation light, as relatively few cellular components are naturally fluorescent (called intrinsic or [[autofluorescence]]).
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* DNA detection: the compound [[ethidium bromide]], in aqueous solution, has very little fluorescence, as it is quenched by water. Ethidium bromide's fluorescence is greatly enhanced after it binds to DNA, so this compound is very useful in visualising the location of DNA fragments in [[agarose gel electrophoresis]]. Intercalated ethidium is in a hydrophobic environment when it is between the base pairs of the DNA, protected from quenching by water which is excluded from the local environment of the intercalated ethidium. Ethidium bromide may be carcinogenic – an arguably safer alternative is the dye [[SYBR Green]].
* FIGS ([[Fluorescence image-guided surgery]]) is a medical imaging technique that uses fluorescence to detect properly labeled structures during surgery.
* [[Intravascular fluorescence]] is a catheter-based medical imaging technique that uses fluorescence to detect high-risk features of atherosclerosis and unhealed vascular stent devices.<ref name="pmid20210433">{{citeসাময়িকী journalউদ্ধৃতি|vauthors=Calfon MA, Vinegoni C, Ntziachristos V, Jaffer FA | title=Intravascular near-infrared fluorescence molecular imaging of atherosclerosis: toward coronary arterial visualization of biologically high-risk plaques. | journal=J Biomed Opt | year= 2010 | volume= 15 | issue= 1 | pages= 011107 | pmid=20210433 | doi=10.1117/1.3280282 | pmc=3188610 | bibcode=2010JBO....15a1107C }}</ref> Plaque autofluorescence has been used in a first-in-man study in coronary arteries in combination with [[optical coherence tomography]].<ref name="pmid26971006">{{citeসাময়িকী journalউদ্ধৃতি|vauthors=Ughi GJ, Wang H, Gerbaud E, Gardecki JA, Fard AM, Hamidi E, etal |title=Clinical Characterization of Coronary Atherosclerosis With Dual-Modality OCT and Near-Infrared Autofluorescence Imaging | journal=JACC Cardiovasc Imaging | year= 2016 | volume= 9| issue= | pages= 1304–1314| pmid=26971006 | pmc=5010789 | doi=10.1016/j.jcmg.2015.11.020}}</ref> Molecular agents has been also used to detect specific features, such as stent [[fibrin]] accumulation and enzymatic activity related to artery inflammation.<ref name="pmid26685129">{{citeসাময়িকী journalউদ্ধৃতি|vauthors=Hara T, Ughi GJ, McCarthy JR, Erdem SS, Mauskapf A, Lyon SC, etal | title=Intravascular fibrin molecular imaging improves the detection of unhealed stents assessed by optical coherence tomography in vivo | journal=Eur Heart J | year= 2015 | volume= | issue= | pages= ehv677| pmid=26685129 | doi=10.1093/eurheartj/ehv677}}</ref>
* SAFI (species altered fluorescence imaging) an imaging technique in [[electrokinetic phenomena|electrokinetics]] and [[microfluidics]].<ref>{{Citeসাময়িকী journalউদ্ধৃতি
|pmid = 23463253
|url = https://microfluidics.stanford.edu/Publications/ParticleTracking_Diagnostics/Shkolnikov_A%20method%20for%20non-invasive%20full-field%20imaging%20and%20quantification%20of%20chemical%20species.pdf
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|df = dmy-all
}}</ref> It uses non-electromigrating dyes whose fluorescence is easily quenched by migrating chemical species of interest. The dye(s) are usually seeded everywhere in the flow and differential quenching of their fluorescence by analytes is directly observed.
* Fluorescence-based assays for screening [[Toxicity|toxic]] chemicals. The optical assays consist of a mixture of environmental-sensitive fluorescent dyes and human skin cells that generate fluorescence spectra patterns.<ref name="Moczko2016">{{Citeসাময়িকী journalউদ্ধৃতি
| pmid = 27653274
| pmc = 5031998
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===Optical brighteners===
{{Mainমূল articleনিবন্ধ|Optical brightener}}
Fluorescent compounds are often used to enhance the appearance of fabric and paper, causing a "whitening" effect. A white surface treated with an optical brightener can emit more visible light than that which shines on it, making it appear brighter. The blue light emitted by the brightener compensates for the diminishing blue of the treated material and changes the hue away from yellow or brown and toward white. Optical brighteners are used in laundry detergents, high brightness paper, cosmetics, [[high-visibility clothing]] and more.
 
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==References==
{{reflistসূত্র তালিকা|30em}}
 
==Bibliography==
* {{citeবই bookউদ্ধৃতি|ref=Lakowicz|author=Lakowicz, Joseph R. |year=1999|title=Principles of Fluorescence Spectroscopy|publisher=Kluwer Academic / Plenum Publishers|isbn=978-0-387-31278-1}}
 
==External links==
{{commonsকমন্স categoryবিষয়শ্রেণী|Fluorescence}}
* [http://www.fluorophores.org Fluorophores.org], the database of fluorescent dyes
* [http://micro.magnet.fsu.edu/primer/techniques/fluorescence/fluorescenceintro.html FSU.edu], Basic Concepts in Fluorescence
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{{Authority control}}
 
[[Categoryবিষয়শ্রেণী:Fluorescence| ]]
[[Categoryবিষয়শ্রেণী:Dyes]]
[[Categoryবিষয়শ্রেণী:Molecular biology]]
[[Categoryবিষয়শ্রেণী:Radiochemistry]]
 
[[বিষয়শ্রেণী:আণবিক জীববিজ্ঞান]]