z*h
发帖数: 773 | 1 Even As can replace P as a component of DNA, which is not as important as
they claim. If As can replace P in ATP, it will be a great discover. My
guess is impossible.
Why arsenic is toxic? Because arsenic can replace phosphate, resulting in a
breakdown of ATP generation. So, this paper is nothing based on available
evidences. A reminder is that Science editors are academic losers because
they cannot get a faculty position in any decent university. |
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s********n
发帖数: 2939 | 2 我觉得他所说的在As中繁殖是指利用As产生能量吧，这早就发现过了，利用As的化合物
作为电子供体或者受体。
phosphate
DNA |
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s******s
发帖数: 13035 | 3 也不是完全不可以。前面有人贴过，Tris有点细胞毒性，所以
活细胞是用PBS的；Phosphate对某些酶活性有干扰，所以为了
方便，体外分子生化啥的用TBS。这个WB没什么关系，不过一般
还是用TBS的比较多，再说Tris实在是太便宜 |
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f***8
发帖数: 571 | 4 Last week's high-profile announcement about a bacterium that thrives on
arsenic is drawing criticism from scientists in multiple fields, including
chemists. The study claims that the microbe can swap phosphorus for arsenic
in its biomolecules, including DNA (C&EN, Dec. 6, page 36; Science, DOI: 10.
1126/science.1197258). But outside experts say the data presented don't back
this claim.
NASA astrobiologist Felisa Wolfe-Simon and her colleagues have been the
subject of worldwide media attention si... 阅读全帖 |
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b******3
发帖数: 377 | 5 就是做结构的。。。
CD谱蛋白浓度多少？1mg/mL行不？主要是盐浓度有50mM phosphate，有问题没？ |
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m**z
发帖数: 787 | 6 CD需要的蛋白量是很少的，一般~10 uM,就可以了，体积应该是400-500ul的样子，不同
的仪器和cuvette可能会不同。50 mM phosphate有一点高，另外NaCl也会影响。不过这
些影响主要都在far UV region (180-200nm).对于看二级结构的话应该影响不大 |
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r****i
发帖数: 323 | 8 J Recept Signal Transduct Res. 2010 Dec;30(6):372-5. Epub 2010 Aug 23.
On the roles of Mg in the activation of G proteins.
Birnbaumer L, Zurita AR.
Laboratory of Neurobiology, National Institute of Environmental Health
Sciences, NIH, DHHS, Research Triangle Park, NC27709, USA. birnbau1@niehs.
nih.gov
Abstract
In this review, we highlight the evolution of our knowledge about the way Mg
(2+) participates in the activation of heterotrimeric G proteins, beginning
with its requirement in hormonal sti... 阅读全帖 |
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s******e
发帖数: 370 | 10 homemade 那肯定是calcium phosphate了
对293这样的细胞，基本上是喂什么吃什么 |
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s*********t
发帖数: 600 | 11 你的calcium phosphate的pH值不准确。差个0.05就会效率差很多。 |
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C*******e
发帖数: 4348 | 13 我们实验室用Thermo Scitific的Glutathione Agarose纯化GST-tag蛋白
他们的手册上说用Tris buffer
想问问看有没有人用过别的buffer
比如HEPES，phosphate，Bicine之类的？
打电话去tech support已经下班了：（ |
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a*******g
发帖数: 57 | 14 Title:Intestinal Phosphate Transport
Advances in Chronic Kidney Disease
Volume 18, Issue 2, March 2011, Pages 85-90
Email to: a*******[email protected]
万分感谢啊！！！ |
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a********k
发帖数: 2273 | 18 花了一个小时，深深的鄙视一下自己的无聊行径！！
125 蔡亮 男 1980年11月 复旦大学 生命
科学 2007年12月毕业于[美国]北卡大学 [美国]加州大学旧金山分校 博士后
Cai L, Mostov K. Polarity is destiny. Cell. 2009 Nov 13;139(4):660-2. PubMed
PMID: 19914162; PubMed Central PMCID: PMC2900917.
Cai L, Makhov AM, Schafer DA, Bear JE. Coronin 1B antagonizes cortactin and
remodels Arp2/3-containing actin branches in lamellipodia. Cell. 2008 Sep
5;134(5):828-42. PubMed PMID: 18775315; PubMed Central PMCID: PMC2570342.
Cai L, Makhov AM, Bear JE. F-actin... 阅读全帖 |
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s*****o
发帖数: 26 | 19 只做过一次，好像要注意不能用PBS洗细胞。
Critical Steps
Do not wash cells with a phosphate-containing buffer such as PBS. Load all
lanes of each gel with only simultaneously prepared samples. Because
transfer of phosphorylated proteins from a gel with Mn2+-Phos-tag is
difficult, the gel should be first soaked in EDTA-containing transfer buffer
B and the original semi-dry transfer method4 using three transfer buffers
should be performed.
http://www.nature.com/protocolexchange/protocols/594#/reagents |
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O******e
发帖数: 4845 | 20 Severe Congenital Disorder Successfully Treated in a Mouse Model for the
First Time
http://www.sciencedaily.com/releases/2011/12/111222103044.htm
ScienceDaily (Dec. 22, 2011) Using a mouse model, Heidelberg University Ho
spital researchers have for the first time successfully treated a severe con
genital disorder in which sugar metabolism is disturbed. The team headed by
Prof. Christian Korner, group leader at the Center for Child and Adolescent
Medicine, demonstrated that if female mice are giv... 阅读全帖 |
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l**********1
发帖数: 5204 | 21 GTP→GDP already
please go to new book
"New Insights into the Mechanisms
of Cytomotive Actin and Tubulin
Filaments" 2011 Elsevier Inc.
by Christopher H.S. Aylett, Jan Lo¨we, and Linda A. Amos
full text link:
//www2.mrc-lmb.cam.ac.uk/groups/JYL/PDF/AmosReview2011.pdf
its pp20
On phosphate release, Wang and Nogales proposed that the contact
between T7 and the nucleotide of the adjacent subunit within the E-site
interface becomes disrupted, leaving contacts only on the side of the
subunit–subunit ... 阅读全帖 |
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b******s
发帖数: 1089 | 22 (3)
dong xinnian最近几年上升非常猛。好文章也是不断。几周前当选院士也让她成为热点。
我对她的个性并无了解。唯一记得的是几年前参加arabidopsis conference的时候排队
去食物，她就在我背后，当时她在和另外一个教授聊天。感觉她说话非常自信，甚至偶
尔有一点aggressive。但是论坛上有人说她很nice。我在网上读过她回忆她父亲的文章
，感觉她是个很纯真的人。
Wuhan University, Wuhan, Hubei, China Microbiology B.S.
1978 1982
Northwestern University, Chicago, USA Molecular Biology Ph.D. 1983
1988
Harvard Medical School, Boston, USA Plant Mol. Biol. Postdoc
1988-1991
Dong xn PhD时的导师似乎当时也不怎么有名。但是Dong xn发了很多文章。
Wo... 阅读全帖 |
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b******s
发帖数: 1089 | 23 (3)
dong xinnian最近几年上升非常猛。好文章也是不断。几周前当选院士也让她成为热点。
我对她的个性并无了解。唯一记得的是几年前参加arabidopsis conference的时候排队
去食物，她就在我背后，当时她在和另外一个教授聊天。感觉她说话非常自信，甚至偶
尔有一点aggressive。但是论坛上有人说她很nice。我在网上读过她回忆她父亲的文章
，感觉她是个很纯真的人。
Wuhan University, Wuhan, Hubei, China Microbiology B.S.
1978 1982
Northwestern University, Chicago, USA Molecular Biology Ph.D. 1983
1988
Harvard Medical School, Boston, USA Plant Mol. Biol. Postdoc
1988-1991
Dong xn PhD时的导师似乎当时也不怎么有名。但是Dong xn发了很多文章。
Wo... 阅读全帖 |
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l**********1
发帖数: 5204 | 24 En
温习一下 其十一年前的豪言 啊
中国科学：显著的发展和严峻的挑战
——历史演变和现状比较
于2001年12月4日 1st version
饶毅
本文在简要回顾中国科学史的基础上，介绍一些近年研究的内容，肯定中国
科学令人乐观的进步，并讨论可能的意义。同时也指出，中国优秀论文总量仍不
到世界的百分之一，低于中国经济在世界所占的百分比、也不能适应中国持续发
展的要求。中国科学的规模需要相当程度的扩大、质量有待进一步提高。中国科
技还存在面临许多问题和挑战。
中国科学历史上的优秀例子
一个国家科学研究状况可以近似地由发表论文的情况所反映。以下，本文主
要从生命科学的研究来讨论中国科学的情况，一方面这是我有一定判断力的领域，
另一方面生命科学是科学技术最重要的组成部分之一，可以反映科学主流。讨论
中国论文发表情况前，先谈两个背景：中国科学的历史情况，优秀科学和著名杂
志的关系。
奠定中国生命科学研究是二、三十年代协和医学院生理系林可胜和生化系吴
宪。他们不仅自己研究出色，而且培养和带领了其他研究者。林可胜在胃肠道生
理和神经生理有优秀工作。1942年，他在中国当选为美国科学院外籍院士，是... 阅读全帖 |
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l**********1
发帖数: 5204 | 25 sure
add one recent paper
Levy S at al. (2011)
The competitive advantage of a dual-transporter system.
Science. 334: 1408-12.
Abstract
Cells use transporters of different affinities to regulate nutrient influx.
When nutrients are depleted, low-affinity transporters are replaced by high-
affinity ones. High-affinity transporters are helpful when concentrations of
nutrients are low, but the advantage of reducing their abundance when
nutrients are abundant is less clear. When we eliminated such red... 阅读全帖 |
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l**********1
发帖数: 5204 | 26 LZ 可以参考下上周的 Science one report:
Yi W. et al. and Hsieh-Wilson LC (2012)
Phosphofructokinase 1 Glycosylation Regulates Cell Growth and Metabolism
Science 337: 975-980
Abs:
Cancer cells must satisfy the metabolic demands of rapid cell growth
within a continually changing microenvironment. We demonstrated that the
dynamic posttranslational modification of proteins by O-linked β-N-
acetylglucosamine (O-GlcNAcylation) is a key metabolic regulator of glucose
metabolism. O-GlcNAcylation was induced ... 阅读全帖 |
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x**4
发帖数: 112 | 27 http://www.ncbi.nlm.nih.gov/pubmed/22147018
Circadian feeding drive of metabolic activity in adipose tissue and not
hyperphagia triggers overweight in mice: is there a role of the pentose-
phosphate pathway?
Endocrinology. 2012 Feb;153(2):690-9. Epub 2011 Dec 6.
Thanks |
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g***y
发帖数: 205 | 28 1. HK dephosphorylate response regulator的时候，phosphate去哪了？
hk hydrolysis the RR~P, free P就到环境中去了 （可以去TLC 去测？）
还是说 先生称 HK~P， 然后 HK~P 自己dephosphorylation了，free P 去环境中了。
2.in vitro phosphorylation实验中，一个分子量很大的蛋白，能促进HK 的
dephosphorylation，但是不影响 phosphortransfer to RR. 这怎么解释啊？
除了conformation change这种万能解释。 |
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l********n
发帖数: 260 | 29 Ubiquitin, SUMO, and Phosphate: How a Trio of Posttranslational Modifiers
Governs Protein Fate. Helle D. Ulrich[1]. [1] Cancer Research UK London
Research
please send to a*************[email protected].
Thanks! |
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d****e
发帖数: 13 | 30 What is this? I transfected Hela cells with p27 fused to GFP by calcium
phosphate method. The GFP fluorescence localized to nuclei but there a few
bright spots in the nuclei corresponding to the bubbles under bright fields.
Is this normal? are those spots auto fluorescent? |
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j*b
发帖数: 341 | 31 这个PKM2和肿瘤代谢的关系已经知道很久了，这两篇还不是原创贴。
cantley还可以发nature，能不能解释一下？
Anticancer Res. 2003 Mar-Apr;23(2A):1155-8.
Tumor marker pyruvate kinase type tumor M2 in patients suffering from
diabetic nephropathy.
Oremek GM, Rutner F, Sapoutzis N, Sauer-Eppel H.
Source
Central Laboratory, Hospital of the Johann Wolfgang Goethe-University,
Frankfurt/Main, Germany.
Abstract
INTRODUCTION:
Compared to normal tissues all tumors investigated so far and especially
those with a metastatic potential overexpress an isoenzy... 阅读全帖 |
|
j*b
发帖数: 341 | 32 这个PKM2和肿瘤代谢的关系已经知道很久了，这两篇还不是原创贴。
cantley还可以发nature，能不能解释一下？
Anticancer Res. 2003 Mar-Apr;23(2A):1155-8.
Tumor marker pyruvate kinase type tumor M2 in patients suffering from
diabetic nephropathy.
Oremek GM, Rutner F, Sapoutzis N, Sauer-Eppel H.
Source
Central Laboratory, Hospital of the Johann Wolfgang Goethe-University,
Frankfurt/Main, Germany.
Abstract
INTRODUCTION:
Compared to normal tissues all tumors investigated so far and especially
those with a metastatic potential overexpress an isoenzy... 阅读全帖 |
|
k***e
发帖数: 41 | 33 calcium phosphate.
请问二楼， PDL是？ |
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i***i
发帖数: 46 | 34 看到一个hiv test的东西，
里面有：
1 Test Stick, containing a nitrocellulose membrane with adsorbed HIV-1 and
HIV-2 synthetic peptides and goat anti-human IgG, and a pad containing a
blocking agent and protein-A colloidal gold
1 Test Tube, containing 1 mL of a phosphate buffered saline solution with
polymers and an antimicrobial agent
帮朋友问下专业人士，这个stick要和口腔的gum接触，stick的东西对人体有没有危害
的可能？那个合成的多肽，会不会有传染性？还有那个tube里面的东西，要是不小心接
触人体会怎样？
谢谢大家。 |
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s*****a
发帖数: 59 | 35 忘说了，我就是用变性条件做His-purification的，用8M Urea, 100mM Phosphate,
10mM Tris, pH7.8做binding.
我确定His tag是表达的（based on size and DNA sequencing)。基于很多原因，不想
把 his-tag放到另一端。如果是变性条件，tag就肯定不会被包埋吧？
还有另一个可能，之前IP elution 有用1%SDS，之后做buffer exchange (Milliopore
Centricon)后可能SDS去除不完全。但是最坏可能也就是His-binding时有0.1%左右的
SDS，看Ni-NTA compatible list 应该不会影响binding啊 |
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p****y
发帖数: 95 | 36 why use phosphate buffer for His-tag, it will precipitate Ni2+ and your
beads won't bind your His-tag protein anymore |
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b******n
发帖数: 4225 | 37 我们总是用phophate buffer纯化his-tag
没啥问题
phosphate buffer的pH随温度变化没有tris大，也就是pH更稳定 |
|
O*******o
发帖数: 7091 | 38 【 以下文字转载自 Environmental 讨论区 】
发信人: OldogZhao (赵小牛), 信区: Environmental
标 题: Baozi, Help needed w/ Eutrophication Potential Measurements
发信站: BBS 未名空间站 (Sun Sep 15 11:20:57 2013, 美东)
想评价一下不同phosphates化合物对Eutrophication的贡献。程序好象是。培养箱恒温
光照培养， 测水中的叶绿素含量。请有经验的大狭提供参考文献。many thanks |
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g******o
发帖数: 96 | 39 target protein可以被上游kinase磷酸化。serine突变成aspartic acid有表型，可是
serine突变成alanine没有表型。reviewer认为这个位点在正常生理情况下不怎么重要
，并要求解释原因。我的解释是这个位点在in vivo 被高度调控，可能有phosphate不
停的去磷酸化；也可能只有在特定的条件下才被磷酸化。
有人知道有这样的例子吗？只有D mutation 有表型而A mutation 没有表型的。
谢谢！ |
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m******g
发帖数: 467 | 40 Science 14.05.09
稍微了解一下：
1. Large-Scale Psychological Differences Within China Explained by Rice
Versus Wheat Agriculture
Control: tested people from neighboring counties along the rice-wheat border
and found differences that were just as large
小知识：
1. Hippocampal Neurogenesis Regulates Forgetting During Adulthood and
Infancy
2. Rock Soup
Phosphorylated sugar intermediates were probably present in Earth's earliest
oceans
Observed 29 interconversion reactions, including the formation of ribose 5... 阅读全帖 |
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D**********e
发帖数: 41 | 41 My understanding is in acidic pH, because RNA is single stranded, the bases
of RNA ionize with H+, and is soluble in aqueous phase. While DNA is double
stranded, it's base is not exposed, it's not soluble in either aqueous or
organic phase. In basic pH, the phosphate backbone of DNA form salt with Na+
, and become soluble in aqueous phase. |
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c********n
发帖数: 225 | 42 第五篇 Tag! You’re it.
这篇回顾一下用His-tag纯化蛋白带来的一些花絮。
每个蛋白都有自己的脾气，所以表达和纯化他们其实就有点像cooking，从原材料的准
备，配方到调味，把握火候，最后色香味俱全才可能成为一道佳肴 – 对于蛋白就是要
达到有其对应的生物活性了。每每看到“保证型”蛋白表达服务的宣传，心里笑一下，
然后就会想到自己的一个“秘密武器” – 有一个融合蛋白确实可以达到几乎100%的高
效表达， 只是都在包涵体里。从另一方面来讲，如果没有时间和经费的限制，确实每
一个蛋白只要花功夫去做，最后都能达到100%成功率,得到有生物活性的终产物。
大部分人的时间和经费都有限，也不是每一个人都有耐心或有必要成为大厨， 那么就
有了purification tag。 His-tag是个经典。说起Histidine这个氨基酸，它的
imidazole side chain的pKa在6左右，这个特性让Histidine成为很多酶的活性中心的
一个重要组分， 这方面这次就不多讲了；另一方面，histidine也是个很好的metal
chelator， 是很多metallop... 阅读全帖 |
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m****m
发帖数: 395 | 43 想配一个Citrate Phosphate Buffer，网上的配方只说要配pH6.6的溶液取
36.4ml 0.2M的Na2HPO4 stock + 13.6ml 0.1M的citric acid stock 然后稀释至100ml。
请问这个溶液最终的盐浓度(buffer strength)是多少呢？怎么算？由于实验特殊需要
，盐浓度不能太高，以前只配过tris buffer，规定是20mM,10mM。
弱问了，求解 |
|
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h**********r
发帖数: 671 | 45 Thanks a lot! Chi Baozi~~ |
|
m********2
发帖数: 317 | 46 Nat Biotechnol. 2014 Sep;32(9):941-6. doi: 10.1038/nbt.2951. Epub 2014 Jun
22.
Generation of mouse models of myeloid malignancy with combinatorial genetic
lesions using CRISPR-Cas9 genome editing.
给通讯作者写信问了，然后第一作者的回复是这样的:
for the original virus we have been using standard calcium phosphate
transfection wit plasmid ratios of 6:10:1.5 (all ug per 10 cm dish) for
vector:psPAX2:pMD2.G.
The virus was collected at around 24-28h and 36-40h post transfection and
concentrated 50-100x with ultrazentrifuga... 阅读全帖 |
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X******n
发帖数: 914 | 47 Lack of Evidence for PKM2 Protein Kinase Activity－Molecular Cell
Highlights
•PEP-dependent phosphorylation was assayed in cell lysates using
radioactive PEP
•Trace adenine nucleotides can confound PEP-dependent phosphorylation
assay results
•PEP-dependent phosphorylation is rare and is not dependent on PKM2
•We are unable to detect PKM2 protein kinase activity in a variety of
contexts
Summary
The role of pyruvate kinase M2 (PKM2) in cell proliferation is controversial
. A... 阅读全帖 |
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o*******a
发帖数: 242 | 48 Nature. 2015 Apr 30;520(7549):683-7. doi: 10.1038/nature14412. Epub 2015 Apr
15.
A molecular mechanism of artemisinin resistance in Plasmodium falciparum
malaria.
Mbengue A1, Bhattacharjee S1, Pandharkar T1, Liu H2, Estiu G2, Stahelin RV3,
Rizk SS1, Njimoh DL4, Ryan Y1, Chotivanich K5, Nguon C6, Ghorbal M7, Lopez-
Rubio JJ7, Pfrender M8, Emrich S9, Mohandas N10, Dondorp AM11, Wiest O12,
Haldar K1.
Abstract
Artemisinins are the cornerstone of anti-malarial drugs. Emergence and
spread of resistanc... 阅读全帖 |
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B***v
发帖数: 113 | 49 好建议，记下了。
"During vesicle uncoating, primary endocytic vesicles may acquire Rab5, a
small GTPase involved in transport to early endosomes and in early endosome
docking and fusion. Primary endocytic vesicles are targeted to and fuse with
early endosomes expressing phosphatidylinositol(3)-phosphate, PI(3)P, in a
process dependent on Rab5 effector proteins and early endosomal SNAREs."
我觉得抑制endocytosis相对简单。比较困难的是还想找到有哪些靶点，通过对其调节
可以增加endocytosis呢？ |
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g*****x
发帖数: 3283 | 50 小弟不是做生物的，有个关于CRISPR的问题想问下各位。如果gRNA的5'被磷酸化，对识
别和反应活性会有多大影响？目前看文献5'的tolerance非常好，但找不到用5'-
phosphate的gRNA的具体实验，大家有没有什么意见？先谢过了～ |
|
