s******y
发帖数: 28562 | 1 根据我自己的经验，这个并不确实。
有一个事情是，如果两个restriction site 距离得不是很远的话，有一个切了就会
影响到另外一个的切割效率，所以产物中会有一定比例的质粒是只被切了一刀的。
这种质粒会很容易被连接起来，所以不需要占产物的很高比例（即使只占1%）也能产生
很高的transformation effeciency. |
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n*****n
发帖数: 202 | 2 you don't have to have all the points in the description. But you have to be
productive, high effecient, with multi-task skills, hard working,and honest
. |
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v****e
发帖数: 131 | 3 问大家一个问题.
我知道senescence associated beta-gal staining 是最常见的方法检测senescence是
否发生了改变.可不幸的是我们的flox老鼠在构建的时候插入了beta-gal基因.所以当我
们基因被knockout后,beta-gal就会表达.我们平时用普通beta-gal staining 这个来
trace deletion effeciency and etc.
我的问题是还能用senescence associated beta-gal staining (SA-b-gal) 来检测
senescence是否发生了变化?注意到SA-b-gal staining的ph值要求是6.我们平时做的
staining是ph 7.其它步骤都是一样的.是不是可能这个ph的一点不同,能够使我们老鼠
中依然可以做senescence associated beta-gal staining.
anyway,我还是可以做western 检测marker.据我所知有PAI-1,P21,P53,P19.我发现P19,
PAI-1改变,但P53不变,mak... 阅读全帖 |
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m******5
发帖数: 1383 | 4 在文章中可以直接用dCT作纵坐标么？同时把internal control的effeciency列出
（不换算成 target Efficiency^dCT/ internal efficiency ^dCT） |
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n***w
发帖数: 2405 | 5 Did you load the entire volume or you just load a portion? I can't say for
Chip but when I did regular IP I used a small volume and loaded all onto the
gels and this would tell me how efficient my IP works. |
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m******5
发帖数: 1383 | 6 right now my problem seems to not be about ip but rather westernblot on
cross linked sample . my input did not work as well. |
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g*********3
发帖数: 177 | 7 It seems you have trouble in reverse-crosslinking step. show us your recipe
for reverse crosslinking. Run a gel on dna. |
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m******5
发帖数: 1383 | 8 Thank you!
I did not go through the reverse crosslinking step for Chip-qPCR
What I did is I washed the dynal-beads by Ip buffer and boiled for 15 mins
in invitrogen LDS protein loading buffer.
recipe |
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d****7
发帖数: 109 | 10 我刚做ChIP的时候也遇到过这种情况，这种现象可能是factor specific
这样吧，你在跑ChIP的时候，再多跑一下两个样品：
(1) un-crosslinked whole cell extract
(2) crosslinked but un-sonicated chromatin
如果(1)都没有目的条带，证明抗体根本不识别蛋白，或者蛋白根本不表达。但是既然
你说是knockin tag，也许表达亮太低
如果(1)有带，(2)没有，说明蛋白的epitope可能被formadehyde毁掉了
如果(1) (2)都有带，超声后的input没有带，证明oversonication，把蛋白给毁了，我
最近就遇到这种情况，都是input，超声前能检测到带，超声后就没了。。。。
还有，煮10分钟足以，30分钟有点过 |
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f**u
发帖数: 346 | 11 有点不明白你说的(2)。这个直接去跑的话那不是等于在跑完整的chromatin，这么大一
团东西怎么跑？ |
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d****7
发帖数: 109 | 12 对，完整的chromatin是一大坨，但是加了sample buffer，煮了之后，就不是了
跑起来没问题 |
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m******5
发帖数: 1383 | 13 非常感谢！！！另外很不好意思这么迟才回复。
这也就是说westernblot crosslinked sample是个routine的手段来检测抗体是否work
for Chip了？
为什么常见的protocol都只要求Co-IP verify antibody呢？ |
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j*******u
发帖数: 81 | 14 当然不是必须的
你的实验里最doMinant的因素是 differentiation effeciency和purification
methods. |
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w**d
发帖数: 2334 | 15 i know it is hard to beat BLAS. In my understanding, the for-loop might be not
as effecient as BLAS, but won't be slower than the standard for-loop in C or
Fortran.
But the main reason for the slow speed of for-loop is because during
the for-loop, lots of intermediate variables are generated.
In the new version, it is not done in that way if the matrix variable
has been initialized.
Mathworks has done something to improve the speed. You can go to the website of mathworks, and search with
keywor |
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k*******t
发帖数: 23 | 16 May I ask whether this book helps a lot? Could you please share the
experience?
<>
And for the general part, how to prepare effeciently?
Thanks a lot. |
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Q***5
发帖数: 994 | 17 Don't know about the NPC property.
But, for P>1, L_P norm often leads to convex problem, therefore, effecient
numberical methods can be used to find the optimal solution.
When P = 1, it is still convex -- but the smoothness of the problem is poor,
therefore, need more care and computing time.
For P<1 (including 0), the problem is generally non-convex, ordinary
numerical routine (e.g. gradient descent) can only leads to local optimal
solution. Finding the global optimal solution can be charllengi |
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g****t
发帖数: 31659 | 18 看来我没记错，一般的L0是NP hard。
ref:
http://www.computer.org/portal/web/csdl/doi/10.1109/ICASSP.2009.4960346
Don't know about the NPC property.
But, for P>1, L_P norm often leads to convex problem, therefore, effecient
numberical methods can be used to find the optimal solution.
When P = 1, it is still convex -- but the smoothness of the problem is poor,
therefore, need more care and computing time.
For P<1 (including 0), the problem is generally non-convex, ordinary
numerical routine (e.g. gradient desc |
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x*******9
发帖数: 200 | 19 The reseason I only have 500 score in NBME test3 I thought is due to Ob,
prevention and management. does anybody have good idea about improve them
effeciently? I thought I understand something, but still got wrong anserwer.
Thank you!!! |
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l*****l
发帖数: 85 | 20 Li batteries have been used and will be used for many applications. There
are always lots of work to make them cheaper and better. It does nothing
with those papers with so-called "creative ideas".
DSSC is almost a dead area unless the liquid electrolyte can be replaced
with polymer/solid while keeping the overal efficieny to 10%. Compared to Li
batteries, the space for 创新 in this area is much more limited. TiO2 is
still The Material since the early of 1990s.
Organic-inorganic solar cell is fanc... 阅读全帖 |
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m*****n
发帖数: 5245 | 21
Can't agree more. The R&D effeciency in Big Pharma is so low. They just hire
lots of employees doing nothing. |
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a**u
发帖数: 5 | 22 I have a problem that bothers me a lot. I always feel nervous when I try to
read books written in English. I feel my heart beating very fast and messy in
my mind for the first half an hour or so once I begin to read. Then I will
calm down. But after about 15 min reading, I can't concentrate on my reading
at all but think about various other things, or do other things, such as
eating snacks, watching TV...
This way I am far from effecient in studying...I am a Ph.D. and my major
requires a lot of |
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c******r
发帖数: 6 | 23 Hi,
Sincere thank to Ahhaau and Fern for their discussions about this problem. :)
Two points I want to make:
1. I've tried to use simulated annealing to do iterative improvement. But
because of the effect of parameter tuning, the algorithm is kind of slow.
That's why I want to find a computationally effecient algorithm to solve it.
If not, at least a good heuristics.
2. I also tried to formulate the constraints as integer constraints. But
notice that the cost functions may not be linear, so solv |
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l***a
发帖数: 12410 | 24 the problem of SAS proc sql is when SAS translate it to Oracle database, it
doesn't translate in the way you code it. e.g. where statement constraints
are not always embeded in the oracle queries and probably splitted as
another match merge query. this usually results in much lower effeciency and
doesn't matter if you code it as sub-query or join style |
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z*******h
发帖数: 346 | 25 比如不管是啥一律pass by value. 暴大的matrix也pass by value, 太变态乐吧。这种
情况显然是pass by reference更effecient. |
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g*********r
发帖数: 2847 | 26
never done such.
it is not effecient for clients to pay us for the grunt work |
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g*********r
发帖数: 2847 | 27
never done such.
it is not effecient for clients to pay us for the grunt work |
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p******s
发帖数: 229 | 28 10^6 or more records, easily reach 10^8.
Being effecient is a main consideration while handling large data.
A skilled programmer can end a program running in couple hours. That may
take a day or days in green hands. |
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