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科学家开发新技术 可以大规模生产生物降解微型机器人_我的网站

一 |     为了创造一种每分钟可以生产100多个可在体内分解的微机器人技术，大邱庆北科技学院（DGIST）机器人和机电工程系的Hongsoo Choi教授团队与韩国天主教大学首尔圣玛丽医院的Sung-Won Kim教授团队以及苏黎世联邦理工学院的Bradley J. Nelson教授团队合作。    

    Drivers queue at a petrol station to refuel in Tehran, on August 25, 2026. Photo: VCG
As military strikes and diplomatic negotiations have both failed to bring an early end to the roughly six‑month‑old US-Iran conflict, Washington rolled out new sanctions against Tehran on Monday local time intended to further strangle its economy. Iran, for its part, has vowed a tougher pushback.
In a news conference on Monday, Treasury Secretary Scott Bessent threatened new sanctions on countries refusing to cut economic ties with Iran, following recent rhetoric from Washington threatening an "economic D-Day" for Iran. 
Meanwhile, the Office of Foreign Assets Control (OFAC) under the US Treasury announced secondary sanctions on nearly 60 entities, individuals, and vessels in multiple jurisdictions which, according to the US' claims, enable Iran's activities, including so-called nuclear and missile technology procurement, cyber operations, and oil-revenue generation networks.
According to Reuters, those sanctions targeted businesses in China, the UAE, Singapore and several other countries, including a cooking-oil refinery in France, but did not include any of the Chinese financial institutions suspected of facilitating Iran's oil trade.
In response to US Treasury Secretary Scott Bessent laying out plans for economic asphyxiation of Iran, expanding Washington's secondary sanction threats and warning of dire consequences for countries that do not join the campaign, Chinese Foreign Ministry spokesperson Lin Jian said at a press briefing on Tuesday that China has made clear on many occasions its firm opposition to illicit unilateral sanctions that have no basis in international law or the authorization of the UN Security Council. 
"Economic warfare and maximum pressure provide no solution. On the contrary, they only serve to fuel tensions and lead to risk spillover, which will disrupt the global economic and financial order, and harm the legitimate rights and interests of other countries," the spokesperson said. 
The pressing task is to facilitate the deescalation of the situation and return to dialogue and negotiation as soon as possible, Lin said, adding that China will do everything necessary to firmly safeguard its rights and interests, Lin added. Lin also said China's cooperation with Iran is conducted within the framework of international law, thus should not be disrupted.
When asked whether China has received any such timeline, as the US stated it would give countries a timeline on when to shut down the actions that it has identified, and how China intends to respond to the relevant announcements by the US Treasury involving China-based entities and individuals, Chinese Foreign Ministry spokesperson Lin Jian stated on Tuesday that China is closely following the developments, and will do everything necessary to firmly safeguard our rights and interests.
In May this year, China's Ministry of Commerce issued a blocking ban prohibiting any recognition, enforcement or compliance with US sanctions imposed on five Chinese companies on the grounds of their alleged involvement in Iranian petroleum transactions.
Relying on its financial hegemony and long‑arm jurisdiction, the US enforces unilateral sanctions with no basis in international law. Such measures severely undermine fundamental consensus for international trade and erode the existing international order, Zhou Mi, senior research fellow at the Chinese Academy of International Trade and Economic Cooperation, told the Global Times on Tuesday.
In essence, Washington is imposing its Iran‑focused policies to enterprises across the globe, compelling third‑party actors to fall in line with its diplomatic objectives, Zhou noted.
The latest sanctions would affect a broader range of countries, industries and firms. They will not only draw wider opposition from the international community, but also boomerang on the interests of US‑owned enterprises, he added. 
Fewer levers left 
"We are launching an economic onslaught against Iran's financial connections around the globe," Bessent claimed at a press conference. "Our objective is to sever every economic lifeline" that sustains the country, he said, according to a Treasury release. 
The US Treasury Department said in a release that the new sectoral sanctions determinations target five critical sectors - digital assets, technology, gold, aviation and shipping - that the US claimed Iran has relied on to support its economy.
US Treasury claimed that "any entity that facilitates money laundering or sanctions evasion on behalf of Iran risks being cut off from the US financial system."
OFAC also suspended several general licenses that previously authorized certain remittance payments to Iran and Iranian access to the US cultural and academic system. The office also issued additional guidance on the so-called sanctions risks of bowing to Iranian demands related to shipping in the Strait of Hormuz.
Mohammad Mokhber, an aide to Supreme Leader Mojtaba Khamenei, said in an X post on Monday that Iran's response to US sanctions and pressure will be "more decisive than before."
Iranian Economy Minister Ali Madanizadeh said that Tehran "is and was ready," with a two-year plan to counter Washington's new sanctions. He told state television that "it seems they wished to suffer yet another defeat," per an AFP report. 
Iranian Parliament Speaker Mohammad Bagher Ghalibaf responded in an X post that "the Americans know no one will believe their nonsense," noting that the US is not in a position economically to restrict its relations with other countries. 
Alan Eyre, a distinguished diplomatic fellow at the Middle East Institute, told NBC News that after six months of combat, the US government "has few remaining levers it can use to convince Iran's major trading partners to materially reduce their economic ties."
While Washington's maximum‑pressure campaign may deliver short‑term shocks to Iran's economy, it can hardly "strangle" the country completely, said Liu Zhongmin, a professor at the Middle East Studies Institute of Shanghai International Studies University.
He added that Iran's economic resilience cannot be underestimated. Having borne decades of crippling sanctions from the US and Western nations, Tehran has built substantial experience in sanction‑busting and developed coping mechanisms ranging from basic‑industry self‑reliance and regional trade networks to oil‑for‑goods swaps and non‑US dollar‑denominated trade. Furthermore, the Strait of Hormuz remains a source of strategic leverage for Iran to push back against US pressure.
The expert said that Tehran and Washington are encountering "a battle of wills," and Iran believes the economic costs the US would suffer from a Hormuz blockade would outweigh the damage inflicted on Iran by sanctions.
Washington's "economic strangulation" policy risks ending in failure unless it yields short‑term outcomes, particularly securing the opening of the Strait of Hormuz, Liu added. 
Self-created dilemma
As the US ramps up pressure on Iran, Americans are growing averse to a protracted war.
According to a Reuters/Ipsos poll that closed on Monday, US ‌public approval of the war with Iran fell to its lowest level since the conflict's early days, with just 31 percent of Americans supporting US military action.
On June 18, the US and Iran signed an MoU, under which the two were scheduled to hold negotiations within a period of 60 days, which ended on August 17, to reach a final agreement. However, the talks' fate remains unclear following renewed escalation between the two countries.
Iranian political analyst Mostafa Khoshcheschm told Al Jazeera that the new US sanctions intended to create an "economic onslaught" were a "political show" of intimidation. 
Liu said that by resorting to an "economic strangulation" tactic after miring itself in a fruitless military quagmire over Iran, the US has laid bare its practical predicament and strategic dilemma, and seemingly running out of cards.
Citing sources, CNN reported earlier this month that the US military has exhausted nearly 80 percent of its interceptors for a key missile defense system as senior US military commanders are warning that the Pentagon's munitions stockpile is "dangerously low."
Faced with depleted ammunition stockpiles and insufficient military‑industrial capacity, and amid growing domestic criticism of its Middle East policy, the White House has opted for tough economic measures against Iran, Liu said. "Less costly than military coercion, such moves help Washington strike a tough posture before voters and shun political risks from further military escalation," said the expert.
There is, however, an increasingly obvious paradox in Washington's economic warfare against Iran: the tighter the sanctions, the tighter global energy supplies become, and the higher costs borne by American consumers and businesses, the expert added. 
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以微创靶向精准治疗为目标，构建微型机器人的方法有很多。其中最受欢迎的是被称为双光子聚合法的超精细3D打印工艺，它通过两个激光器相交引发合成树脂的聚合。这种技术有能力创建具有纳米级精度的结构。缺点是创建一个微型机器人需要大量的时间，因为体素，即通过3D打印实现的像素，必须连续固化。此外，在双光子聚合过程中，机器人中的磁性纳米粒子可能会阻碍光路。当利用高浓度的磁性纳米粒子时，过程结果可能不均匀。为了解决目前微机器人生产技术的限制，DGIST教授Hongsoo Choi的研究团队创造了一种方法，通过将磁性纳米颗粒和可生物降解的甲基丙烯酸明胶的混合物流到微流控芯片上，以每分钟100个的高速度制造微机器人，该混合物可以通过光固化。与现有的双光子聚合方法相比，这可以使制造微型机器人的速度提高1万倍以上。然后，用这种技术生产的微型机器人与从人的鼻子中收集的人类鼻甲骨干细胞进行培养，以诱导干细胞粘附到微型机器人的表面。

二 | 通过这一过程，制造了一个干细胞携带的微型机器人，包括内部的磁性纳米颗粒和附着在外表面的干细胞。当机器人内部的磁性纳米粒子对外部磁场作出反应时，机器人就会移动，并能移动到所需的位置。
在现有的干细胞疗法中，选择性的细胞输送是困难的。然而，携带干细胞的微型机器人可以通过实时控制电磁场控制系统产生的磁场而移动到所需的位置。研究小组进行了一项实验，检查携带干细胞的微型机器人是否能通过一个迷宫状的微通道到达目标点，并因此证实机器人可以移动到所需的位置。此外，通过将携带微型机器人的干细胞与一种降解酶进行孵化，评估了微型机器人的可降解性。孵化6小时后，微机器人完全解体，机器人内部的磁性纳米粒子被磁场控制系统产生的磁场收集。干细胞在微型机器人被解体的地方增殖。随后，干细胞被诱导分化成神经细胞，以确认正常分化；干细胞在大约21天后被分化成神经细胞。该实验验证了使用微型机器人将干细胞运送到所需位置是可能的，而且运送的干细胞可以通过表现出增殖和分化来作为一种有针对性的精确治疗剂。

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Published on:17:26:23