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可能会改变世界的SPN到底是什么?

SPNs Might Change the World, So What Are They?

Thank you to Climeworks for sponsoring today’s video.
感谢Climeworks赞助今天的视频
Climeworks removes carbon dioxide from the atmosphere,
Climeworks公司从大气中去除二氧化碳
helping fight the climate crisis.
来帮助对抗气候危机
Go to gift.climeworks.com/SciShow
请访问gift.climeworks.com/SciShow网站
to give the sustainable gift of CO2 removal this holiday season.
在这个节日里送上一份去除二氧化碳的环保礼物
[♪ INTRO]
[ 开场曲]
Science is always fun,
科学总是很有趣的
but it’s not every day that researchers get to go out into the parking lot
但并不是每天都有研究人员去停车场
and run their experiment over with their car.
然后用车碾压他们的试验品
On purpose! For science reasons!
这是他们为了科学研究的有意为之!
But, researchers publishing online last week in the journal Nature Materials
但是 上周在《自然材料》杂志发表文章的研究人员
did just that.
恰恰就是这样做的
It was one way to demonstrate
这是他们展示
the awesomeness of their newly developed “super jelly,”
新研发的“超级果冻”惊人之处的一种方式
a soft material that regains its shape surprisingly well under pressure.
“超级果冻”是一种压力下可以很好地恢复形状的柔软材料
Their new material is a type of hydrogel,
它们的新型材料是一种水凝胶
a material made from a network of molecules that hold onto water.
这是一种由极为亲水的分子网络所构成的材料
In fact, this hydrogel is made up of 80 percent water,
事实上 这种水凝胶的80%的成分是水
which the researchers say makes it even more surprising that
研究人员说 更令人感到惊讶的是
it doesn’t, like, pop like a water balloon would under pressure.
它不会像水球一样在压力下破裂
Most of the time,
大多数时候
it’s soft and flexible, kind of like squishy jelly.
它既柔软又有弹性有点像黏糊糊的果冻
But put some pressure on it,
但是给它施加一些压力
and this material’s change to become more like a glass.
这种材料的性能会变得更像玻璃
我们说的是很大的压力
In this case, approximately the weight of an elephant,
针对本实验 压力大小约等于一头大象的重量
or, ya know I did mention a car earlier.
或者像我之前提过的 一辆汽车
Even when compression does cause it to change shape,
即使压缩确实会改变它的形状
the hydrogel can spring back into its original shape in about two minutes.
水凝胶也能在大约两分钟内回弹至原来的形状
So what makes this wacky combination of material properties possible?
那么 是什么让这奇特的材料属性组合成为可能呢?
The hydrogel is part of a class of materials
这种水凝胶属于一种
known as supramolecular polymer networks, or SPNs.
被称为超分子聚合物网络(SPN)的材料
These are materials made of polymers, or chains of molecules,
它们由聚合物或分子链组成
that are assembled together using non-covalent bonds.
这些聚合物或分子链用非共价键聚集在一起
In a conventional polymer,
在普通聚合物中
long chains of molecules are held together by relatively stable covalent bonds.
长长的分子链通过相对稳定的共价键连接在一起
Individual polymers may also be crosslinked together,
个别聚合物也可能交联在一起
which means that various points on different polymers are attached to each other.
这意味着不同聚合物上的各个点相互附着
And that makes everything hold together a bit more.
从而使所有东西都更加紧密地结合在一起
Those crosslinks are generally also formed from covalent bonds,
这些交联键通常也是由共价键形成
which are interactions where atoms share electrons
这些共价键是在原子共享电子的相互作用下形成
and generally require a chemical reaction to make or break.
通常需要化学反应才能使之形成或断裂
SPNs do often contain conventional polymers that are held together by covalent bonds.
SPN通常含有由共价键连接在一起的普通聚合物
But polymers within the SPN are crosslinked by more transient intermolecular forces,
但SPN内部的聚合物则更多是由瞬态分子间作用力交联的
such as hydrogen bonding.
例如氢键
These crosslinks form and dissolve and form again in an equilibrium.
在平衡状态中这些交联键形成 溶解 再形成
That temporariness gives SPNs all kinds of special properties.
这种短暂性让SPN有了各种特殊的属性
Because their molecules can shift their crosslinks around on the fly,
由于它们的分子可以快速改变交联键
the materials are stretchy,
因此这种材料是有弹性的
can repair themselves quickly,
它们可以进行快速地自我修复
can dissipate excess energy, and are usually soft.
消耗多余的能量 它们通常是比较柔软的
But while researchers have tried optimizing those temporary bonds for those properties,
但是 尽管研究人员已经试图优化这些暂时性化学键的属性
the researchers behind this study wondered
但这项研究背后的研究人员想知道
what would happen if the temporary bonds actually stuck around a little longer.
如果暂时性化学键实际停留的时间稍长一点会发生什么
The hypothesis was that
他们假设
longer-lasting bonds would nudge the SPN towards a state that
持续时间更长的化学键会促使SPN
is more resistant to any forces applied to it.
对施加在其上的任何作用力都更具有抵抗力
So, the researchers developed a library of slightly-tweaked possible molecules
因此 研究人员开发了一个可稍作调整的分子库
that might be slower to dissolve a crosslinked bond.
这些分子可以使交联化学键溶解得更慢
They tested out lots of different options,
他们测试了许多不同的可能性后
and observed that some behaved in a more rigid manner.
观察到有些可能性的表现更为抗压
And ultimately,
他们最终发现
the one whose bonds dissolved the slowest was the strongest when compressed.
在被压缩时 化学键溶解最慢的最抗压
And that is our super jelly!
这就是我们的超级果冻!
In addition to running it over repeatedly with their car,
研究人员除了用车反复碾压它们
the researchers also developed a pressure sensor from the material that
他们还利用该材料开发了一个压力传感器
they used to measure people walking, and standing, and jumping.
来测量人们在行走 站立 和跳跃时的压力
You know, just to show that
你知道的 他们只是为了展示
it does have applications for things like soft robotics and bioelectronics.
它在软体机器人和生物电子学等方面的应用
But honestly, even if it’s not useful yet,
但说实话 即使它还没有用处
the super jelly’s squishy-yet-shatterproof combination?
柔软又不易碎的超级果冻结合体?
Pretty darn cool.
这太酷了
Speaking of supramolecular polymer networks,
说到超分子聚合物网络
and no, I’m not kidding.
我并没有开玩笑
This time, they acted as scaffolding to help heal spinal injuries.
这次 它们用来充当支架来帮助治愈脊柱损伤
In a study published last month in the journal Science,
在上个月发表在《科学》杂志上的一项研究中
researchers injected paralyzed mice with nanofibers that
研究人员给瘫痪的老鼠注射了纳米纤维
triggered injured spinal cord cells to regenerate.
从而引发损伤的脊髓细胞再生
Within 3 to 4 weeks, the mice could walk again.
在3到4周内 老鼠又能行走了
Now it’s super important to note that this study was only done in mice.
需要特别注意的是 这项研究只是在老鼠的身上进行
This technique has not been used to treat spinal injuries in humans, yet.
这项技术还没有被用于治疗人类脊柱损伤
But for the mice, the results were definitely promising.
但对于老鼠来说 这个结果肯定是有保证的
The damaged neurons regrew their long signaling tails, called axons.
受损的神经元重新长出长的信号尾 这个便是轴突
The mice also developed less scar tissue and more new blood vessels
老鼠患处瘢痕组织减少 新的血管增多
in the region in question, which are important for successful healing.
这个结果对成功愈合来说很重要
As a neat bonus, the molecules all broke down within 12 weeks,
更妙的是 这些分子在12周内全部分解
leaving nothing behind but nutrients for the cells to use.
只留下了营养物质来供细胞使用
The nanofibers were injected in liquid form.
纳米纤维以液体的形式注入
But once they made contact with living tissue,
但它们一旦与活组织接触
the fibers bonded to each other to form a gel-like SPN that
纤维就会相互粘合形成一种凝胶状的SPN
mimicked the normal scaffolding around the cells of the spinal cord.
从而模仿脊髓细胞周围的正常支架
Importantly, the fibers also contained components that
重要的是 这些纤维还含有
would encourage the spinal neurons to regenerate.
促进脊髓神经元再生的成分
Some of them were attached to a molecule that signals neural stem cells to turn into neurons,
它们其中一些附着在了从神经干细胞转化为神经元的信号分子上
while others were attached to a molecule that encourages cells to reproduce and survive.
而另一些附着在了促进细胞繁殖和存活的分子上
The researchers expected that a more stable scaffold structure
研究人员期望一个更稳定的支架结构
would help ensure that receptors on neurons and other cells would
来帮助神经元和其他细胞上的受体
encounter the signaling molecules attached to the fibers.
遇到附着在纤维上的信号分子
The signaling molecule could then bind to the cells
然后信号分子可以与细胞结合
and instruct them to begin repairing themselves.
并引导细胞开始自我修复
But the weak bonds of the fibers’ SPN meant that even once they were
但纤维SPN的化学键很弱 这意味着即使它们
assembled into their extracellular scaffolding,
被聚集到细胞外支架中
the fibers continued to move slightly, sometimes even escaping the network.
纤维也会继续轻微移动 甚至有时会逸出网状结构
And to the researchers’ surprise, that movement seemed to be important.
令研究人员惊讶的是 这一运动似乎很重要
They found that the versions of their fibers that moved more within their structure
他们发现 在其结构内运动更多的纤维
also correlated with better healing and regeneration.
也能使患处更好的愈合和再生
While they can’t say for sure that the movement caused this better result, they think it likely did.
虽然他们无法肯定是运动导致了更好的结果 但他们认为很可能是这样的
The target cells and their receptors also move around,
由于靶细胞和它们的受体也在运动
so the researchers think the fibers’ movement could
因此研究人员认为纤维的运动可能
increase the chance that they’ll collide with a receptor.
会增加它们与受体结合的机会
The researchers say the finding could even help explain
研究人员说 这一发现甚至可以帮助解释
why biological systems so often have proteins that seem messy and disordered.
为什么生物系统常常有看起来混乱无序的蛋白
It’s possible that the chaos could help with cellular signaling.
这种混乱也许对细胞信号有帮助
Now that’s all we know about this for now
这是我们目前所知道的内容
, but the results are so promising that the researchers say
但研究结果是如此有希望以至于研究人员表示
they want to adapt the technique for use in humans very soon.
他们渴望不久可以将这项技术应用在人类身上
But also this more basic principle that motion is important to cell signaling?
但也是这个基本的原理 即运动对细胞信号重要吗?
They say that could someday have even broader applications,
他们说 可能有朝一日会有更广泛的应用
from countering neurodegenerative diseases to better targeting all kinds of drugs.
从对抗神经退行性疾病到更好地针对各种药物
Thanks for watching this episode of SciShow News, which was supported by Climeworks.
感谢收看本期由Climworks赞助的《科学秀》
The climate crisis is the most important issue facing us right now.
气候危机是我们目前面临的最重要的问题
And it’s going to take action on a lot of fronts to fight it,
Climworks将在许多方面采取行动来对抗它
but Climeworks aims to give you one tool you can use to help.
但Climeworks的目的在于可以给你一个帮助你的工具
Climeworks works to address the climate crisis by removing carbon dioxide from the air.
Climeworks致力于通过去除空气中的二氧化碳来解决气候危机
They use a type of technology called direct air capture,
他们使用直接捕获空气的技术
which removes CO2 directly from the atmosphere.
直接从大气中去除二氧化碳
The CO2 can then be reused, upcycled, or stored geologically.
然后这些二氧化碳可以被重新利用 升级改造 或在地质上储存
You can subscribe at different tiers
你可以订购不同级别的服务
to remove up to 50kg of CO2 per month.
每月最多去除50公斤的二氧化碳
That’s 30 days of central heating in a home!
这相当于一个家庭30天的集中供暖!
And if you’re looking for gifts for the holidays,
如果你在为节日挑选礼物
a subscription could be an awesome, environmentally friendly gift
订购是一种令人敬畏 环保的礼物
to help inspire climate-positive action.
有助于激励积极的气候行动
You can head to gift.climeworks.com/scishow
你可以前往gift.climeworks.com/scishow网站
to give the gift of CO2 removal this holiday season.
在这个节日里送上去除二氧化碳的礼物
[♪ OUTRO]
[片尾曲]

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视频概述

你知道SPN吗?那你知道“超级果冻”吗?如果你对此感到好奇的话,就跟随视频看看可能会改变世界的SPN到底是什么吧!

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翻译译者

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审核员

审核员YUE

视频来源

https://www.youtube.com/watch?v=rqqVOcg1_AY

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