n**********g
发帖数: 196 | 1 OK, you want basic chemistry and here is basic chemistry.
“Since ssDNA
can not bind to the editing enzyme alone in vitro, the conclusion will be
the enzyme needs the second substance that is a conformation-ready genomic
DNA to form a functional enzyme-ssDNA-genomic target DNA complex to complete
the reaction. ”
----This is so wrong. There could be 100 reasons why an enzyme does not bind
a substance. For example, temperature, pH. Most importantly, it directly
contradicts Han’s data (Fig 1,2).
“As... 阅读全帖 |
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H***5
发帖数: 129 | 2 Harper, K. C.; Sigman, M. S. Proc. Natl. Acad. Sci. U. S. A. 2011, 108, 2179.
Predicting and optimizing asymmetric catalyst performance using the
principles of experimental design and steric parameters
Harper, K. C.; Bess, E. N.; Sigman, M. S. Nat. Chem. 2012, 4, 366.
Multidimensional steric parameters in the analysis of asymmetric catalytic
reactions
Harper, K. C.; Sigman, M. S. Science (Washington, DC, U. S.) 2011, 333, 1875.
Three-Dimensional Correlation of Steric and Electronic Free Energy
R... 阅读全帖 |
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b**s
发帖数: 589 | 3 I think you are talking about DLVO and zeta potential things.
polyelectrolyte will offer two stabilization effects, electro and steric.
the zeta potentail can be zero but there are still steric effects. try to dip
it into a positivly charged salt solution, you will find the latex will be
coagulated instead.
positivly |
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c**********a
发帖数: 6 | 4 Dendrimer-based dispersant have great performance.
To lead the solid matter such as pigment into a liquid medium, a high
mechanical strength is necessary, traditionally, use dispersants to deal
these substances, mainly related surfactants. In addition, the dispersed
solid material tends to re-coalescence and flocculate the entire system,
current disadvantage of the products is that viscosity is limited to lower
with highly filled colored dispersion system. Dendritic dispersant has
superior dispe... 阅读全帖 |
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a*******a
发帖数: 332 | 5 空间位阻=steric hindrance
~~~~~~~参加 b 类型。。
PS：岳啥啥=岳灵珊？ 林啥啥=林平之？
~~~~~~~~ noble gas？
~~~~~~~~~双置换反应？
依稀觉得这个帖子往学术版发展的潜力了。。。 |
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i****s
发帖数: 729 | 6 steric resistance, i get it now. |
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x****e
发帖数: 53 | 7 大概就是steric hindrance 吧， 先 A 后 B 試試 |
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w******e
发帖数: 1187 | 8
sorry, 没看懂-_-
我的目的是测一个蛋白，想用该蛋白的一个interacting peptide做capturing agent，
用aptamer做detection agent，用peptide instead of Ab做capturing agent的
原因是1. 担心aptamer跟ab有steric hindrance；2. 不想用ab呵呵 |
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m*********7
发帖数: 5207 | 9 只能用cy5么？你不担心steric hindrance? |
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发帖数: 1 | 10 You leave me no choice but . I can not stand someone without any chemistry
sense when he/she is a biologist.
Chemical reaction is a on/off equilibrium. Some enzymes pick up the first
substance first and then the second one if the space arrangement is allowed
in the active site; some enzymes bind to a coordinated substance complex if
the reaction needs both substances available at the same time to fit into
the active site. It depends on the nature of individual enzymes. Since ssDNA
can not bind t... 阅读全帖 |
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n*******n
发帖数: 12 | 14 mitsunobu won't work because of the steric hindrance. But you can still try
it.
I think the induction came from the bata-keto functionalily. Try to use L-
selectride or Bu4NBH4. These two reagents usually deliver opposite
selectivity as NaBH4 does. |
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w**q
发帖数: 43 | 15 Just a thought.
For ester alone, s-cis form is favored(anomeric, A1,2 and dipole).
After addn of AlCl3, for Me, the s-trans...AlCl3 could be stable since Me is
small. But for Et, both s-cis...AlCl3 and s-trans...AlCl3 are unstable
complex due to steric effect. s-cis...AlCl3 is ready for IM cleavage of Et. |
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w*****y
发帖数: 36 | 16 Issue:
I think that steric effect is a major reason as you have a big aromatic
group AND a bulky alkyl group neighboring to the leaving group.
Proposed solutions:
1.Try lithium exchange to attack 4-X butylnitrile (X=I,Br,OTs etc);
2.Refer to Buchwald's Tetrahdron review paper to identify a specific
bidendate ligand that may work for you.
Good luck! |
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q****i
发帖数: 6923 | 17 http://www.sciencedirect.com/science/article/pii/S0022328X00925
(Aroyloxymethyl)trifluorosilanes: a new class of pentacoordinate silicon
compounds.
Journal of Organometallic Chemistry (1980), 201, (1), 165-77. CODEN:JORCAI
ISSN:0022-328X.
Synthesis of organofunctional silanes with sterically hindered substituents
at silicon atoms Full TextBy Gulinski, Jacek et al
From Applied Organometallic Chemistry, 15(8), 649-657; 2001
s****[email protected] |
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m******2
发帖数: 114 | 18 many thanks for your reply!
a good point, but I beg to differ. since silylation involves Si-H and Si-CH
=CH2, Si-O contribution should not be pivotal? if it is, then it is mainly
due to steric hindrance after si-o bonding with the alkyne alcohol?
hope you can make more comments. any reference on Si-O quick bonding? thx! |
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j**********i
发帖数: 187 | 19 Borkovec and Behrens, 2006
M. Borkovec, S.H. Behrens
Stabilization of aqueous colloidal dispersions: electrostatic and steric
forces
Encycl Surf Colloid Sci (2006), pp. 5765–5774
发到 w******[email protected]
谢谢了。 |
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b****i
发帖数: 8 | 20 pls don't laugh at me. My chemistry is total rubbish.
Anyone can tell me what's the meaning of *C (star on left top of Carbon atom)
in a carbon chain, and what's then meaning of a black point above on the
Carbon atom.
Also how to say in Chinese that 'steric effect', and the meaning.
Sorry I can't input Chinese. Anyone could tell me the answer in Chinese will
be most help!
Thx a lot! |
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c*****e
发帖数: 238 | 21 If I remember correctly, the radical is usually represented by a dot,
I hardly remember anything related with an asterisk, maybe an asymmetric
carbon atom, or an isotopic carbon.
steric effect译为位阻效应吧.
It is generally caused by the hindrance of large groups. |
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t******l
发帖数: 3060 | 22 how you try the reaction?
that reaction should be easy.
is ur polymer dissolve in solvent?
since ur -OH group is not that steric hindered. the general mathod can be.
dissolve in Solvent like Acetonnitrile, add K2CO3, add such as 1-bromoHexane.
refluxing for 24h. that's it.
for more rigorous condition. u can use stronger base, like KtBuO. refluxing in
higher temp. |
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M*******n
发帖数: 508 | 23 来自主题: Macromolecules版 - 几个弱智问题 do you mean apparent density by bulk density?
for (1) and (3), I don't think so. At least, you have steric effects.
and that's why we have LDPE and HDPE, right? |
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y***e
发帖数: 6082 | 24 ATRP没啥前途的，RAFT对单体相对来说就好多了，可惜又对CTA选择性太强，总之活性
聚合要走的路还很长
why? because of the extreme large of the monomer? I tried some ATRP on my
synthesized monomer, it failed, too. but the reason is very likely because
the size of the monomer which cuase some steric difficulties. |
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s****e
发帖数: 2934 | 25 ☆─────────────────────────────────────☆
cds (红毛呼呼猪) 于 (Sat Sep 9 13:15:25 2006) 提到:
大家认识一下阿
☆─────────────────────────────────────☆
yueke (小鱼儿) 于 (Wed Sep 20 11:58:05 2006) 提到:
ATRP没啥前途的，RAFT对单体相对来说就好多了，可惜又对CTA选择性太强，总之活性
聚合要走的路还很长
why? because of the extreme large of the monomer? I tried some ATRP on my
synthesized monomer, it failed, too. but the reason is very likely because
the size of the monomer which cuase some steric difficulties.
☆─────────────────────────────────────☆
hu |
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c*s
发帖数: 2145 | 26 sounds like steric effect plays a role and you might try copolymerize with
other monomer |
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G*******s
发帖数: 92 | 27 Nag A, Ghosh PC. J Drug Target. 1999; 6(6):427-38. Assessment of targeting
potential of galactosylated and mannosylated sterically stabilized liposomes
to different cell types of mouse liver.
email: n***********[email protected]
谢谢!! |
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