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238674eaea4d3dd22114b8e1a3c9ff4c8251228a
intrahippocampal injection of 8 μg of cangitoxin in
intrahippocampal injection of 8 μg of cangitoxin in rats has strong behavioral effects, leading to akinesia interchanging with facial automatisms and head tremor, salivation, rearing, jumping, barrel-rolling, wet dog shakes and forelimb clonic movements. in addition, convulsions occur which gradually increase in durati...
wikipedia
b5da7218dbab7c2f6c74dd49de12e479451042e1
according to its sequence homology, it is likely
according to its sequence homology, it is likely that cangitoxin prolongs the inactivation of the voltage-gated sodium channels by binding on the external side of the plasma membrane, thereby preventing the outward movement of the ivs4 transmembrane segment. this blockage prevents the conformational change that is esse...
wikipedia
dc4e5f3cc2516833b3feb792c4a146b61e5a197f
sea anemone toxins act on voltage-gated sodium channels
sea anemone toxins act on voltage-gated sodium channels (na 1.1, na 1.2, na 1.4, na 1.5, na 1.6, na 1.7) and depending on their affinity to a specific isoform, they mainly act on cardiac or neuronal voltage-gated sodium channels. sea anemone toxins act at the receptor site 3. on the basis of its sequence homology, cang...
wikipedia
33bc66886cf87092975436a93d6f37103d412d00
cangitoxin is to varying degrees homologous to the
cangitoxin is to varying degrees homologous to the other sea anemone toxins. the most prominent is the homology to the type 1 class sea anemone toxins (85%). the homology of cangitoxin to the type 2 and 3 class sea anemone toxins is less, respectively 50% and 30%. the major neurotoxin bciii (bciii) isolated from bunodo...
wikipedia
2af20fb9cf58eab74a832c7d980d45f571ccfde5
substitution of the 16th amino acid, asparagine (n),
substitution of the 16th amino acid, asparagine (n), into an aspartic acid (d) is named cangitoxin-ii (cgtx-ii). cangitoxin-iii (cgtx-iii) contains in addition to the previous substitution, a replacement of the 14th amino acid, arginine (r), into histidine (h).
wikipedia
0787cf38f0efed8711dad28bb32dfc9ea78a1488
cangitoxin belongs to the type 1 class sea
cangitoxin belongs to the type 1 class sea anemone toxins, consisting of long polypeptides with short anti-parallel β–sheets and three disulfide bonds. cangitoxin is a 4958 da peptide, with the primary structure gvacrcdsdgptvrgnslsgtlwltggcpsgwhncrgsgpfigycckk and disulfide bonds cys4-cys45, cys6-cys35, and cys28-cys46...
wikipedia
18d3c861fcbe557b68cf13fbad038c449c02d63d
cangitoxin is a polypeptide isolated from the venom
cangitoxin is a polypeptide isolated from the venom of bunodosoma cangicum, a common sea anemone species found in the intertidal zone during low tides on the coastal reefs of the brazilian seashore.
wikipedia
f2bc33e1dd6400bbf5033609f08fd836c4194fd2
cangitoxin, also known as cgtx or cgx, is
cangitoxin, also known as cgtx or cgx, is a toxin purified from the venom of the sea anemone bunodosoma cangicum, which most likely acts by prolonging the inactivation of voltage-gated sodium channels (na channels).
wikipedia
1d2d5f65efa774632089e7aad3963ffbe0a78f8b
charles blair was a scottish-born canadian ice hockey
charles blair was a scottish-born canadian ice hockey player. he played one game in the national hockey league with the toronto maple leafs during the 1948–49 season, on december 4, 1948, against the chicago black hawks. the rest of his career, which lasted from 1948 to 1961, was mainly spent in the american hockey lea...
wikipedia
dc920655881bbf7ef6f16f9488a6bb66391b8972
blair was born in edinburgh, scotland, and while
blair was born in edinburgh, scotland, and while still an infant, he immigrated with his family to canada. he played junior hockey with the oshawa generals before he was called up by the toronto maple leafs to play his one and only national hockey league game. after spending time with the toronto marlboros, blair signe...
wikipedia
9c8bef71b943fc22e106661a43034730d5cff551
charles blair (july 23, 1928 – december 14,
charles blair (july 23, 1928 – december 14, 2006) was a scottish-born canadian ice hockey player. he played one game in the national hockey league with the toronto maple leafs during the 1948–49 season, on december 4, 1948, against the chicago black hawks. the rest of his career, which lasted from 1948 to 1961, was mai...
wikipedia
2a4661e3d53d148e1475d80836bd09ef6fe0f73e
dabong bridge is a bridge in dabong, kelantan,
dabong bridge is a bridge in dabong, kelantan, malaysia. it was built between 2004 and 2006. this bridge was officially opened on 20 august 2006 by malaysian prime minister abdullah ahmad badawi.
wikipedia
2a4661e3d53d148e1475d80836bd09ef6fe0f73e
dabong bridge is a bridge in dabong, kelantan,
dabong bridge is a bridge in dabong, kelantan, malaysia. it was built between 2004 and 2006. this bridge was officially opened on 20 august 2006 by malaysian prime minister abdullah ahmad badawi.
wikipedia
989aa12a48789069f94cf7599d4adde581cbae4a
daniel gottesman is a physicist, known for his
daniel gottesman is a physicist, known for his work regarding quantum error correction, in particular the invention of the stabilizer formalism for quantum error-correcting codes, and the gottesman–knill theorem. he is a faculty member at the university of maryland. gottesman completed a b.a. in physics at harvard univ...
wikipedia
a3b2bd4d4b5dd3bf97d542133bed099e341b0479
gottesman completed a b.a. in physics at harvard
gottesman completed a b.a. in physics at harvard university (1992) and a ph.d. in physics at caltech (1997). he is a fellow of the american physical society (2013). in 2003, he was named to the mit technology review tr100 as one of the top 100 innovators in the world under the age of 35.
wikipedia
5d60103db064b7f5fe6ca3aafd8f122165be9c30
daniel gottesman is a physicist, known for his
daniel gottesman is a physicist, known for his work regarding quantum error correction, in particular the invention of the stabilizer formalism for quantum error-correcting codes, and the gottesman–knill theorem. he is a faculty member at the university of maryland.
wikipedia
578c69ae949c022a4fb504b2055e89cf3f6546bb
eskicioglu has published over 80 academic papers which
eskicioglu has published over 80 academic papers which have been cited over 2900 times, resulting in an h-index and i10-index of 23 and 43 respectively. she has previously received a natural sciences and engineering research council (nserc) postgraduate scholarship, the british columbia confederation of university facu...
wikipedia
7607941117a767b43833a2050fad3202c0300f67
conventional fermentation methods can take several weeks, or
conventional fermentation methods can take several weeks, or months, to generate methane. in collaboration with international groups, eskicioglu has developed a new waste pre-treatment technique, where common materials in agricultural waste, including douglas fir bark, can generate methane faster. in addition, eskiciog...
wikipedia
69c2361cd1b8b48c64540da4984baa9c037b6a74
eskicioglu leads the ubc bioreactor technology group at
eskicioglu leads the ubc bioreactor technology group at the university of british columbia's okanagan campus, where her lab develops wastewater treatment technologies, including waste processing and biological treatment. in 2020, she was appointed as the senior industrial research chair (irc), awarded by the natural sc...
wikipedia
62f933819ed9b344386f53749b224cb6a9c6de87
eskicioglu was born in turkey, and spent her
eskicioglu was born in turkey, and spent her first ten years in istanbul. she cites her experiences in turkey, including traffic jams and a lack of clean water and air, as what prompted her interest in environmental issues. she completed a bachelor of science degree in environmental engineering at the istanbul tech uni...
wikipedia
f3ad017ae6b0ad58ee1f68ab8e994412b8672608
douglas gordon "the gleichen cowboy" young was a
douglas gordon "the gleichen cowboy" young was a canadian ice hockey defenceman who played mostly for the detroit red wings of the national hockey league. young was also captain of the red wings from 1935 to 1938 leading the team to two stanley cup wins. the original (cup) belts are on display in the nhl hall of fame.
wikipedia
df676976dec71aeda7c4d2827448cee8690dc9b0
prior to 1940, young was signed as a
prior to 1940, young was signed as a free agent by the montreal canadiens, where he would play his last 50 games in the nhl. young was claimed on waivers by the toronto maple leafs in 1940 and was set down to their farm team, the providence reds of the american hockey league. young finished out his career scoring 22 po...
wikipedia
62c52092e0b2cbfa8ca580b9c4ecca5bbaaa7e66
within a two-month span in 1931, young was
within a two-month span in 1931, young was claimed by the philadelphia quakers in an inter-league draft, claimed by the new york americans in the dispersal draft, and traded to the detroit falcons for ron martin. so finally, on october 18, 1931, young had found his nhl home with the detroit falcons. in the 1931–32 seas...
wikipedia
fd98058d4b29b1535c72f08a336fe4738e9eb3e8
young had a great start to his hockey
young had a great start to his hockey career when he was part of the 1926 memorial cup champion calgary canadians. he followed this feat by joining the canadian professional hockey league as a member of the kitchener millionaires (later renamed the toronto millionaires) and playing sound defensive hockey. the ihl took ...
wikipedia
44f4a5607d81bcf4f18ec10e7518ba746858bf69
douglas gordon "the gleichen cowboy" young (october 1,
douglas gordon "the gleichen cowboy" young (october 1, 1908 – may 15, 1990) was a canadian ice hockey defenceman who played mostly for the detroit red wings of the national hockey league. young was also captain of the red wings from 1935 to 1938 leading the team to two stanley cup wins. the original (cup) belts are on ...
wikipedia
e147abcc8f5dc294fbcd996f6bfce003a8af745b
edward neville da costa andrade frs was an
edward neville da costa andrade frs was an english physicist, writer, and poet. he told the literary digest his name was pronounced "as written, i.e., like air raid, with and substituted for air." in the scientific world andrade is best known for work that first determined the wavelength of a type of gamma radiation, p...
wikipedia
20932c08dac074f9522d4e4a626d140b6698ad02
he was quain professor of physics at university
he was quain professor of physics at university college, london from 1928 to 1950, and then fullerian professor of chemistry at the royal institution for three years, until opposition to his attempts to reform the ri led to a vote of no confidence in him by members of the ri, following which he resigned. in 1943 andrad...
wikipedia
71dbfb9d7ba58cf32499056aed8c3608af59f91a
in 1910 edward neville studied for a doctorate
in 1910 edward neville studied for a doctorate on the electrical properties of flames under prof lenard at the university of heidelberg and then had a brief but productive spell of research with ernest rutherford at manchester in 1914. they carried out diffraction experiments to determine the wavelengths of gamma-rays ...
wikipedia
9be3c115909cae9b681110d60cc063d2ec37ddd2
edward neville andrade was a sephardi jew, his
edward neville andrade was a sephardi jew, his family having arrived in london from portugal during the napoleonic era, and was a descendant of moses da costa andrade (not moses da costa as is sometimes stated). da costa andrade was his 2nd great-grandfather, a feather merchant in london's east end. the surname "andrad...
wikipedia
bd2b292fff9c5db63032c507b6ecc18cbe353bce
edward neville da costa andrade frs (27 december
edward neville da costa andrade frs (27 december 1887 – 6 june 1971) was an english physicist, writer, and poet. he told the literary digest his name was pronounced "as written, i.e., like air raid, with and substituted for air." in the scientific world andrade is best known for work (with ernest rutherford) that first...
wikipedia
cb6f7dd349e28de7a6e858a9330d192e0fe9400c
denise walsh is an american political scientist, currently
denise walsh is an american political scientist, currently a professor of political science and women, gender and sexuality at the university of virginia. she studies the relationship between women's rights and political inclusion and level of democracy, as well as women's advancement during periods of democratization.
wikipedia
2ed95facf1defa9214ff476e0454d87f4557ed74
walsh is a member of the 2020-2024 editorial
walsh is a member of the 2020-2024 editorial leadership of the american political science review, which is the most selective political science journal. she was also the 2016-2017 president of the women's caucus for political science in the american political science association.
wikipedia
49ab537fcaea287df91066b06d54644e82e6a8a4
walsh has published on women's representation and rights
walsh has published on women's representation and rights in democracies in journals like politics & gender, ps: political science & politics, and comparative political studies. she has also published articles on research ethics, and on the status of women in the discipline of political science.
wikipedia
b4ba22b391a11e2f4631719a2d4aab360022be3a
walsh wrote the book women's rights in democratizing
walsh wrote the book women's rights in democratizing states: just debate and gender justice in the public sphere, published in 2010. the book confirms and advances findings that democratization does not generally increase women's participation in politics, as political institutions and parties often block women's advan...
wikipedia
dfeb90839eeafade2832f1a0a5aaa59c46dbbae6
walsh studied politics and economics at bennington college,
walsh studied politics and economics at bennington college, earning a ba in 1985. she completed an ma in political science at columbia university in 1986, and a phd in political science from the new school for social research in 2006. in 2005, she became a professor at the university of virginia, where she was also a c...
wikipedia
cb6f7dd349e28de7a6e858a9330d192e0fe9400c
denise walsh is an american political scientist, currently
denise walsh is an american political scientist, currently a professor of political science and women, gender and sexuality at the university of virginia. she studies the relationship between women's rights and political inclusion and level of democracy, as well as women's advancement during periods of democratization.
wikipedia
45eb4ae5411a32a25149dd0e820ee70999c4b892
in mathematics, the cartan–kähler theorem is a major
in mathematics, the cartan–kähler theorem is a major result on the integrability conditions for differential systems, in the case of analytic functions, for differential ideals i . it is named for Élie cartan and erich kähler.
wikipedia
9fad62f5536777e2047a1931382269da1289fe2d
then there exists a (locally) unique connected, (k
then there exists a (locally) unique connected, (k + 1) {\displaystyle (k+1)} -dimensional, real analytic integral manifold x ⊆ m {\displaystyle x\subseteq m} of i {\displaystyle i} that satisfies p ⊆ x ⊆ r {\displaystyle p\subseteq x\subseteq r}.
wikipedia
43475bdb5873204fd0f41124c1fbb3af40732080
moreover, assume there is a real analytic submanifold
moreover, assume there is a real analytic submanifold r ⊆ m {\displaystyle r\subseteq m} of codimension r (p) {\displaystyle r(p)} containing p {\displaystyle p} and such that t p r ∩ h (t p p) {\displaystyle t_{p}r\cap h(t_{p}p)} has dimension k + 1 {\displaystyle k+1} for all p ∈ p {\displaystyle p\in p}.
wikipedia
a3a2a8cb0c26590d4297dd2ca7ecf810daa87af3
let (m, i) {\displaystyle (m,i)} be a real
let (m, i) {\displaystyle (m,i)} be a real analytic eds. assume that p ⊆ m {\displaystyle p\subseteq m} is a connected, k {\displaystyle k} -dimensional, real analytic, regular integral manifold of i {\displaystyle i} with r (p) ≥ 0 {\displaystyle r(p)\geq 0} (i.e., the tangent spaces t p p {\displaystyle t_{p}p} are "...
wikipedia
95c9cb891c8d6201f1fa5f384d68dca4a7548e51
it is not true that merely having d
it is not true that merely having d i {\displaystyle di} contained in i {\displaystyle i} is sufficient for integrability. there is a problem caused by singular solutions. the theorem computes certain constants that must satisfy an inequality in order that there be a solution.
wikipedia
e24067d90dd66a0252d96fc05407f9b833d13a8a
in mathematics, the cartan–kähler theorem is a major
in mathematics, the cartan–kähler theorem is a major result on the integrability conditions for differential systems, in the case of analytic functions, for differential ideals i {\displaystyle i}. it is named for Élie cartan and erich kähler.
wikipedia
6e4674552e4110763983a621bcc073a16ca70da0
the continental o-240 engine is a four-cylinder, horizontally
the continental o-240 engine is a four-cylinder, horizontally opposed, air-cooled aircraft engine that was developed in the late 1960s for use in light aircraft by continental motors, inc. the first o-240 was certified on 7 july 1971.
wikipedia
b264e095641f7b7141d12586cf3ecc0cff5e28c1
the iof-240 is similar to the io-240-b except
the iof-240 is similar to the io-240-b except that it employs an aerosance fadec system to control the ignition and fuel injection systems. the engine was not selected to power any production north american-manufactured aircraft until the liberty xl2 entered production in 2006 powered by the iof-240-b.
wikipedia
f0105fa00e896132e84742d2a21a8a666e6b4ae1
the o-240 was produced under license in the
the o-240 was produced under license in the united kingdom by rolls-royce limited and was used to power the reims-cessna fra150 aerobat, a more powerful aerobatic model of the cessna 150 constructed in france by reims aviation under license. rolls-royce acquired the rights to the o-240, but not the io-240 in 1977.
wikipedia
9e7a3773044f5f0d60f2b8527314927183000e2f
the 130 hp (97 kw) o-240 was a
the 130 hp (97 kw) o-240 was a new engine design derived from the six-cylinder continental o-360 and introduced in 1971. it is generally similar in overall dimensions to the continental o-200, but with a higher 8.5:1 compression ratio, designed to run on 100/130 avgas. the o-240 delivers 30% more power than the o-200 w...
wikipedia
6e4674552e4110763983a621bcc073a16ca70da0
the continental o-240 engine is a four-cylinder, horizontally
the continental o-240 engine is a four-cylinder, horizontally opposed, air-cooled aircraft engine that was developed in the late 1960s for use in light aircraft by continental motors, inc. the first o-240 was certified on 7 july 1971.
wikipedia
9c9782d7a2bfb673f8eba8736063093a128a1899
dallas earl smith is a canadian former ice
dallas earl smith is a canadian former ice hockey defenceman who played fifteen seasons for the boston bruins and new york rangers of the national hockey league between 1960 and 1978. with the bruins smith won the stanley cup in 1970 and 1972. internationally he played for the canadian national team at the 1977 world c...
wikipedia
6e7289812f8f9958fbe287c219e446b0113f86e8
smith began the 1977 season after an acrimonious
smith began the 1977 season after an acrimonious contract dispute which saw him sign a one-year contract the day before the season began, and which caused him to miss training camp. he was named interim captain of the bruins after longtime captain john bucyk was injured, but left the team in march after a dispute, play...
wikipedia
a7e32421ef985e1c27f9e76ab7b2de4d53b157d1
with the expansion in 1967 smith made the
with the expansion in 1967 smith made the bruins for good and, partnered with superstar bobby orr on defence, led the nhl in plus/minus the first season the statistic was officially tabulated. he gained a reputation as a solid defensive defenceman — as well as a wide repute as the league's strongest man, bolstered by h...
wikipedia
e5132e0f0343dcf3751690990fc3cc314b5f93d3
signed as a teenager by the bruins, after
signed as a teenager by the bruins, after a junior career with their estevan bruins farm team, smith made his debut with boston in 1960. he played the full 1961 season with the club, but thereafter spent most of the next seven seasons in the minor leagues, winning second all-star team accolades with the oklahoma city b...
wikipedia
97c64eba0d7debdc04736a3152731789c194126e
dallas earl smith (born october 10, 1941) is
dallas earl smith (born october 10, 1941) is a canadian former ice hockey defenceman who played fifteen seasons for the boston bruins and new york rangers of the national hockey league between 1960 and 1978. with the bruins smith won the stanley cup in 1970 and 1972. internationally he played for the canadian national ...
wikipedia
7bf1ccd15b2328f494dc454dd23e70d6ebc248cf
ctnow is a free weekly newspaper in central
ctnow is a free weekly newspaper in central and southwestern connecticut, united states, published by the hartford courant. the previous iteration of ctnow was new mass. media, a privately owned weekly newspaper company until 1999, when its owners, including founding publisher geoffrey robinson, sold the company to the...
wikipedia
3f3db36efdc17857c01f732ad7b85516e01b006f
advocate weekly newspapers formerly published the valley advocate,
advocate weekly newspapers formerly published the valley advocate, a similar alternative weekly, in easthampton, massachusetts, covering the greater springfield area and the pioneer valley of western massachusetts. it began as an independent newspaper in 1973 and was sold in late 2007 to newspapers of new england, pare...
wikipedia
18c429bd499ea353b7869c943389738a7a0215ef
in the 1980s and '90s the paper included
in the 1980s and '90s the paper included a full-time photographer, nicholas lacy, and an array of colorful editors and reporters, including ric hornung (who was known to eavesdrop on city hall denizens by hiding in the lunch truck and taking notes on their conversations), janet reynolds (who later became publisher), ja...
wikipedia
8dd2d521f27ec9b436e245c8ef8a99a7a98acfde
polman notes, in the acknowledgements for "dateline: connecticut,"
polman notes, in the acknowledgements for "dateline: connecticut," "i had originally hoped to thank the publishers of the hartford advocate for allowing me to reprint some of my 'subject to change' columns, but they denied me access to my work, citing my 'gravitation' to the courant."
wikipedia
f5031268fce26a690e5f76ec5ae2e51ee81bcb3b
in a history of the alternative media, a
in a history of the alternative media, a trumpet to arms, author david armstrong described the advocate as a bastion for the "new muckrakers." the author explored the paper's examination of the behind-the-scenes power exercised by the corporate elite in hartford. kauffman had reported that top banks and insurance compa...
wikipedia
e4ed99dd2fff9b793d4d1fe9a96068b902345c26
polman left the advocate after some five years
polman left the advocate after some five years to become a columnist at the courant and later joined the philadelphia inquirer as national political correspondent. he also taught at the university of pennsylvania. kauffman later worked for cnn, taught at emerson college in boston, morehouse college in atlanta and the u...
wikipedia
8e551f967029f67a91d006bd4bfe2eed0425e2fb
gail collins reported on state government and politics;
gail collins reported on state government and politics; she is now an op-ed columnist at the new york times. another early reporter was david lieberman, who was later an editorial writer for the courant and covered the media business for usa today.
wikipedia
ca2eed9b35d6e75562572fdc80fd6bcc35142d92
the hartford advocate was founded in 1974 by
the hartford advocate was founded in 1974 by geoffrey robinson and edward matys to fill a void in investigative and beat reporting in the capital city of connecticut. for example, the hartford courant, where robinson and matys had previously worked, did not routinely cover one of the city's largest industries, insuranc...
wikipedia
744c324919ca9469223f277c7ae73148ab1ade27
advocate weeklies offered investigative journalism, national, state and
advocate weeklies offered investigative journalism, national, state and local political coverage, commentary, and arts features and criticism, mostly from a liberal or countercultural point of view. they shared some editorial content, but each had regionally focused news and opinion pieces, restaurant reviews, event li...
wikipedia
f1fe649d5f2ea1199cb9f0c02906ad557a55b082
in 1999, the four-paper chain was sold to
in 1999, the four-paper chain was sold to times-mirror, which was itself acquired by tribune in 2000. tribune announced in december 2007 that it would sell the valley advocate, its only massachusetts publication, to newspapers of new england.
wikipedia
ad6fe1a8d545b6d6e4b7a6dc5e692973d18c902c
the pair began publishing the valley advocate, a
the pair began publishing the valley advocate, a bi-weekly serving western massachusetts, in september 1973 from small basement offices in amherst, massachusetts. in september 1974, the valley advocate began publishing weekly; robinson and matys opened offices in hartford and started publication of the hartford advocat...
wikipedia
e57f0e551f831c280a5fd7975c2c6a4a50bcea2e
the company was founded in 1973 by geoffrey
the company was founded in 1973 by geoffrey robinson and edward matys, then copy editors at the hartford courant. robinson, a native of new haven, connecticut, worked as wire service editor of the daily lorain journal of ohio after his graduation from yale university in 1971. matys had worked in editorial positions at ...
wikipedia
9d5ed364434c7956271467be1ac6388ea9e76d21
the previous iteration of ctnow was new mass.
the previous iteration of ctnow was new mass. media, a privately owned weekly newspaper company until 1999, when its owners, including founding publisher geoffrey robinson, sold the company to the hartford courant for an undisclosed sum. a year later, courant parent company times-mirror was bought by the tribune compan...
wikipedia
1c8f8f4be8ed8acf4727652ccb16602af8fec4f9
christine jasoni is an american-born new zealand academic
christine jasoni is an american-born new zealand academic specialising in foetal neural development. she is a professor at the university of otago and has been the director of the university's brain health research centre since 2016. in 2020 she was elected a ngā takahoa a te apārangi companion of royal society te apār...
wikipedia
305d91201b2091b140ca566250f61e432c54731f
christine jasoni crsnz is an american-born new zealand
christine jasoni crsnz is an american-born new zealand academic specialising in foetal neural development. she is a professor at the university of otago and has been the director of the university's brain health research centre since 2016. in 2020 she was elected a ngā takahoa a te apārangi companion of royal society t...
wikipedia
49ec5f184a401df51ff96cc8eeaba0da4ac6f00e
disuccinimidyl suberate (dss) is a six-carbon lysine-reactive non-cleavable
disuccinimidyl suberate (dss) is a six-carbon lysine-reactive non-cleavable cross-linking agent. it consists of functional groups it is a homobifunctional n-hydroxysuccinimide (nhs) ester formed by carbodiimide-activation of carboxylate molecules, with identical reactive groups at either end. the reactive groups are se...
wikipedia
f0d04738e41af9af187f6c4f21d781fbcb304089
disuccinimidyl suberate's reactivity toward primary amines allows it
disuccinimidyl suberate's reactivity toward primary amines allows it to serve as a cross-linking agent for proteins, without toxic side-products and forming peptide bonds with the lysine residues in a single step. in a study on blood substitutes, dss was shown to cross-link hemoglobin intramolecularly, yielding a relat...
wikipedia
75b68aafc87db7fdf3dcdf03bcf6e24f60ebb3b5
a study was done looking at the application
a study was done looking at the application of size exclusion chromatography in the purification of cross-link peptides within samples. when the eluted peptides were analyzed, cross-linked peptides could be detected at higher concentrations in the earlier fractions, eluting before modified or unmodified peptides.
wikipedia
01ee585c30b00e73abfd6ee99158c91ccb04eead
dss is reactive towards amine groups (primary amines)
dss is reactive towards amine groups (primary amines) at ph 7.0-9.0. it is membrane permeable, therefore permitting intracellular cross-linking, has high purity, is non-cleavable, and is water-insoluble (it must be dissolved in a polar organic solvent such as dmf or dmso before addition to sample.)
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0ff27922a953d5b15e5f88a3e8c748fe5146050f
it consists of functional groups it is a
it consists of functional groups it is a homobifunctional n-hydroxysuccinimide (nhs) ester formed by carbodiimide-activation of carboxylate molecules, with identical reactive groups at either end. the reactive groups are separated by a spacer and in this molecule it is a six carbon alkyl chain. this reagent is mainly u...
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f90380902c4b775c1b6fcde874ca6bfc6603dd75
in polymer chemistry, cationic polymerization is a type
in polymer chemistry, cationic polymerization is a type of chain growth polymerization in which a cationic initiator transfers charge to a monomer, which then becomes reactive. this reactive monomer goes on to react similarly with other monomers to form a polymer.
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7664f1ed56b1e4fa1ae134557d82cb04292af757
the types of monomers necessary for cationic polymerization
the types of monomers necessary for cationic polymerization are limited to alkenes with electron-donating substituents and heterocycles. similar to anionic polymerization reactions, cationic polymerization reactions are very sensitive to the type of solvent used. specifically, the ability of a solvent to form free ions...
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6217859653cf0c4ef2a8a8a7038af82ce145d916
other polymers formed by cationic polymerization are homopolymers
other polymers formed by cationic polymerization are homopolymers and copolymers of polyterpenes, such as pinenes (plant-derived products), that are used as tackifiers. in the field of heterocycles, 1,3,5-trioxane is copolymerized with small amounts of ethylene oxide to form the highly crystalline polyoxymethylene plas...
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31de35ecfac908ff6882e9c4433ad72ce19039d1
polybutene is another copolymer, containing roughly 80% isobutylene
polybutene is another copolymer, containing roughly 80% isobutylene and 20% other butenes (usually 1-butene). the production of these low molecular weight polymers (300–2500 da) is done within a large range of temperatures (−45 to 80 °c) with alcl or bf. depending on the molecular weight of these polymers, they can be ...
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dc93fb42f62e7cf977f07d7a71fb024e00f09730
butyl rubber, in contrast to pib, is a
butyl rubber, in contrast to pib, is a copolymer in which the monomers isobutylene (~98%) and isoprene (2%) are polymerized in a process similar to high molecular weight pibs. butyl rubber polymerization is carried out as a continuous process with alcl as the initiator. its low gas permeability and good resistance to c...
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415f08d225da8e18b75ae63d65b3ec1ca7ba391b
the largest commercial application of cationic polymerization is
the largest commercial application of cationic polymerization is in the production of polyisobutylene (pib) products which include polybutene and butyl rubber. these polymers have a variety of applications from adhesives and sealants to protective gloves and pharmaceutical stoppers. the reaction conditions for the synt...
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7e659be745676c6b7be80b4083ac6ee9f567eb11
in 1984, higashimura and sawamoto reported the first
in 1984, higashimura and sawamoto reported the first living cationic polymerization for alkyl vinyl ethers. this type of polymerization has allowed for the control of well-defined polymers. a key characteristic of living cationic polymerization is that termination is essentially eliminated, thus the cationic chain grow...
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07a98047c42fa668af879f60a0a0041c8401f890
in which i is the initiator, m is
in which i is the initiator, m is the monomer, m is the propagating center, and k i {\displaystyle {\mathit {k_{i}}}}, k p {\displaystyle {\mathit {k_{p}}}}, k t {\displaystyle {\mathit {k_{t}}}}, and k t r {\displaystyle {\mathit {k_{tr}}}} are the rate constants for initiation, propagation, termination, and chain tra...
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44921e5745fdfd884e93f7b4733292b66f1b688f
cationic ring-opening polymerization follows the same mechanistic steps
cationic ring-opening polymerization follows the same mechanistic steps of initiation, propagation, and termination. however, in this polymerization reaction, the monomer units are cyclic in comparison to the resulting polymer chains which are linear. the linear polymers produced can have low ceiling temperatures, henc...
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f9641f981d1a3d8be981c37ca90fda6fbb359eeb
chain transfer can take place in two ways.
chain transfer can take place in two ways. one method of chain transfer is hydrogen abstraction from the active chain end to the counterion. in this process, the growing chain is terminated, but the initiator-coinitiator complex is regenerated to initiate more chains.
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b5cb4cc0da66dcfcdf1688c0a801c4245aa393c5
termination generally occurs by unimolecular rearrangement with the
termination generally occurs by unimolecular rearrangement with the counterion. in this process, an anionic fragment of the counterion combines with the propagating chain end. this not only inactivates the growing chain, but it also terminates the kinetic chain by reducing the concentration of the initiator-coinitiator...
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984a2519a5de859069520a0c74a77eb09b0b51e5
the size of the counterion is also a
the size of the counterion is also a factor. a smaller counterion, with a higher charge density, will have stronger electrostatic interactions with the carbenium ion than will a larger counterion which has a lower charge density. further, a smaller counterion is more easily solvated by a polar solvent than a counterion...
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54bb773b26cbf0248152b5f5618b2ca88a1fd7af
the association is strongest as a covalent bond
the association is strongest as a covalent bond and weakest when the pair exists as free ions. in cationic polymerization, the ions tend to be in equilibrium between an ion pair (either tight or solvent-separated) and free ions. the more polar the solvent used in the reaction, the better the solvation and separation of...
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dafd039eb1fb41132b67828a91b10aa3aa919663
the solvent and the counterion (the gegen ion)
the solvent and the counterion (the gegen ion) have a significant effect on the rate of propagation. the counterion and the carbenium ion can have different associations according to intimate ion pair theory; ranging from a covalent bond, tight ion pair (unseparated), solvent-separated ion pair (partially separated), a...
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3b8eb2f8b4567cd19267a9b6ee8b521455b2fa13
chain length is also affected by temperature. low
chain length is also affected by temperature. low reaction temperatures, in the range of 170–190 k, are preferred for producing longer chains. this comes as a result of the activation energy for termination and other side reactions being larger than the activation energy for propagation. as the temperature is raised, t...
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c1d157ac0c8a2cf16f62e5a524395be6df2d6c59
generally, e t {\displaystyle {\mathit {e_{t}}}} is larger
generally, e t {\displaystyle {\mathit {e_{t}}}} is larger than the sum of e i {\displaystyle {\mathit {e_{i}}}} and e p {\displaystyle {\mathit {e_{p}}}}, meaning the overall activation energy is negative. when this is the case, a decrease in temperature leads to an increase in the rate of propagation. the converse is...
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b4b683dd8df33c966f28ceb9972fade701a4552d
the temperature of the reaction has an effect
the temperature of the reaction has an effect on the rate of propagation. the overall activation energy for the polymerization (e {\displaystyle {\mathit {e}}}) is based upon the activation energies for the initiation (e i {\displaystyle {\mathit {e_{i}}}}), propagation (e p {\displaystyle {\mathit {e_{p}}}}), and term...
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8fcd737da630a34775d8556a401b85a7a3d00c4a
propagation proceeds by addition of monomer to the
propagation proceeds by addition of monomer to the active species, i.e. the carbenium ion. the monomer is added to the growing chain in a head-to-tail fashion; in the process, the cationic end group is regenerated to allow for the next round of monomer addition.
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d8b9dc806a09a075b8e6297f8fad976e716725ff
ionizing radiation can form a radical-cation pair that
ionizing radiation can form a radical-cation pair that can then react with a monomer to start cationic polymerization. control of the radical-cation pairs is difficult and often depends on the monomer and reaction conditions. formation of radical and anionic species is often observed.
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e2d8b8bc94f598afc076d64e3227f0c0c7b835b0
stable carbenium ions are used to initiate chain
stable carbenium ions are used to initiate chain growth of only the most reactive alkenes and are known to give well defined structures. these initiators are most often used in kinetic studies due to the ease of measuring the disappearance of the carbenium ion absorbance. common carbenium ions are trityl and tropylium ...
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7f05ce762868633b008ecd1bee8b7222be7c41f7
lewis acids are the most common compounds used
lewis acids are the most common compounds used for initiation of cationic polymerization. the more popular lewis acids are sncl, alcl, bf, and ticl. although these lewis acids alone are able to induce polymerization, the reaction occurs much faster with a suitable cation source. the cation source can be water, alcohols...
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d1acfea1d2ff1ddce434c3672080befc6820a069
strong protic acids can be used to form
strong protic acids can be used to form a cationic initiating species. high concentrations of the acid are needed in order to produce sufficient quantities of the cationic species. the counterion (a) produced must be weakly nucleophilic so as to prevent early termination due to combination with the protonated alkene. c...
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f16a90af64c43acc762406c46f34d150c28136f8
initiation is the first step in cationic polymerization.
initiation is the first step in cationic polymerization. during initiation, a carbenium ion is generated from which the polymer chain is made. the counterion should be non-nucleophilic, otherwise the reaction is terminated instantaneously. there are a variety of initiators available for cationic polymerization, and som...
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3789d719355392e5623890c55565f21d1d6db3d6
heterocyclic monomers that are cationically polymerized are lactones,
heterocyclic monomers that are cationically polymerized are lactones, lactams and cyclic amines. upon addition of an initiator, cyclic monomers go on to form linear polymers. the reactivity of heterocyclic monomers depends on their ring strain. monomers with large ring strain, such as oxirane, are more reactive than 1,...
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de7581ffeb772010ac1593dd93f37f748be6c2a0
cationic polymerization of olefin monomers occurs with olefins
cationic polymerization of olefin monomers occurs with olefins that contain electron-donating substituents. these electron-donating groups make the olefin nucleophilic enough to attack electrophilic initiators or growing polymer chains. at the same time, these electron-donating groups attached to the monomer must be ab...
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c58eb917427e14500e2d20b1b92bb052d39ad4b2
monomer scope for cationic polymerization is limited to
monomer scope for cationic polymerization is limited to two main types: alkene and heterocyclic monomers. cationic polymerization of both types of monomers occurs only if the overall reaction is thermally favorable. in the case of alkenes, this is due to isomerization of the monomer double bond; for heterocycles, this ...
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0ebfe2a326d59b8e87f01f1f622314a3a9e40b84
in polymer chemistry, cationic polymerization is a type
in polymer chemistry, cationic polymerization is a type of chain growth polymerization in which a cationic initiator transfers charge to a monomer, which then becomes reactive. this reactive monomer goes on to react similarly with other monomers to form a polymer. the types of monomers necessary for cationic polymeriza...
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d764a5256182d4f31b1c2caa04752781ce7ef062
on december 10, 2012, he was honored with
on december 10, 2012, he was honored with a special lecture and ceremony co-sponsored by the western center for agricultural health and safety, the university of california, davis, and the national institute for occupational safety and health. john howard, m.d., niosh director, flew to california for the specific purpo...
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