编译 | 李言
nature, 2 november 2023, volume 623 issue 7985
《自然》2023年11月2日,第623卷,7985期
?
材料科学materials science
injectable tissue prosthesis for instantaneous closed-loop rehabilitation
可以进行瞬时闭环康复的可注射组织假体
▲ 作者:subin jin, heewon choi et al.
▲ 链接:
https://www.nature.com/articles/s41586-023-06628-x
▲ 摘要:
在这里,我们提出了一种可注射的组织假体,它们在神经肌肉系统中具有瞬时双向电传导能力。这种柔软的可注射假体由具有独特的苯硼酸介导多重交联的生物相容性水凝胶组成,如不可逆但可自由重排的联苯键和可逆的配位键,通过原位交叉偶联形成导电金纳米颗粒。
在大鼠严重肌肉损伤的早期阶段,通过注射这种假体材料成功实现了机器闭环辅助康复,并在后期实现了组织的加速修复。
▲ abstract:
here we present an injectable tissue prosthesis with instantaneous bidirectional electrical conduction in the neuromuscular system. the soft and injectable prosthesis is composed of a biocompatible hydrogel with unique phenylborate-mediated multiple crosslinking, such as irreversible yet freely rearrangeable biphenyl bonds and reversible coordinate bonds with conductive gold nanoparticles formed in situ by cross-coupling. closed-loop robot-assisted rehabilitation by injecting this prosthetic material is successfully demonstrated in the early stage of severe muscle injury in rats, and accelerated tissue repair is achieved in the later stage.
化学chemistry
quinone-mediated hydrogen anode for non-aqueous reductive electrosynthesis
醌介导的非水还原电合成氢阳极
▲ 作者:jack twilton, mathew r. johnson et al.
▲ 链接:
https://www.nature.com/articles/s41586-023-06534-2
▲ 摘要:
在此,我们报告了一种介导的h2阳极,通过将蒽醌介质的热催化加氢与蒽氢醌的电化学氧化配对,实现了h2的间接电化学氧化。这种醌介导的h2阳极用于支持镍催化的交叉亲电偶联(xec),这种反应类别在制药工业中得到广泛采用。
我们在小规模间歇反应中对该方法进行了初步验证,随后适应了可实现百克级药物中间体合成的再循环反应器。我们的介导h2阳极技术提供了一种支持h2驱动的电合成还原的普遍策略。
▲ abstract:
here we report a mediated h2 anode that achieves indirect electrochemical oxidation of h2 by pairing thermal catalytic hydrogenation of an anthraquinone mediator with electrochemical oxidation of the anthrahydroquinone. this quinone-mediated h2 anode is used to support nickel-catalysed cross-electrophile coupling (xec), a reaction class gaining widespread adoption in the pharmaceutical industry. initial validation of this method in small-scale batch reactions is followed by adaptation to a recirculating flow reactor that enables hectogram-scale synthesis of a pharmaceutical intermediate. the mediated h2 anode technology disclosed here offers a general strategy to support h2-driven electrosynthetic reductions.
carbon-to-nitrogen single-atom transmutation of azaarenes
氮杂芳烃的碳-氮单原子嬗变
▲ 作者:jisoo woo, colin stein, alec h. christian & mark d. levin.
▲ 链接:
https://www.nature.com/articles/s41586-023-06613-4
▲ 摘要:
在此,我们报告了一种使杂芳香碳原子直接转化为氮原子,将喹啉类转化为喹唑啉类的转化过程。母体氮杂芳烃的氧化重组得到了一个开环的中间体,带有亲电位点,为环重合和碳基离去基的排出准备了条件。
这种方法不同于现有的原子插入—删除方法,从而避免了逐步骨骼编辑中常见的骨架旋转和取代基微扰陷阱。我们展示了广泛的喹啉和相关的氮杂芳烃,所有这些都可以通过用氮原子取代c3碳转化为相应的喹唑啉。实验支持了活化中间体的关键作用,并指出了c - n嬗变反应发展的更一般策略。
▲ abstract:
here, we report a transformation that enables the direct conversion of a heteroaromatic carbon atom into a nitrogen atom, turning quinolines into quinazolines. oxidative restructuring of the parent azaarene gives a ring-opened intermediate bearing electrophilic sites primed for ring reclosure and expulsion of a carbon-based leaving group. such a ‘sticky end’ approach subverts existing atom insertion–deletion approaches and as a result avoids skeleton-rotation and substituent-perturbation pitfalls common in stepwise skeletal editing. we show a broad scope of quinolines and related azaarenes, all of which can be converted into the corresponding quinazolines by replacement of the c3 carbon with a nitrogen atom. mechanistic experiments support the critical role of the activated intermediate and indicate a more general strategy for the development of c-to-n transmutation reactions.
气候科学climate science
seasonal advance of intense tropical cyclones in a warming climate
气候变暖时强烈热带气旋的季节性推进
▲ 作者:kaiyue shan, yanluan lin, pao-shin chu, xiping yu & fengfei song
▲ 链接:
https://www.nature.com/articles/s41586-023-06544-0
▲ 摘要:
在此,我们发现自20世纪80年代以来,在大多数热带海洋中,强烈热带气旋出现了显著的季节性推进,北半球和南半球的早移率分别为每10年3.7天和3.2天。强烈热带气旋的季节性推进与快速强化事件的季节性推进密切相关,有利的海洋条件较早出现能快速强化事件的季节性推进。
利用多个全球气候模式、大整体和个别强迫实验的模拟,可以探测到主要由温室气体强迫驱动的有利海洋条件较早出现。强烈热带气旋的季节性推进将增加与其他极端降雨事件相交的可能性,这些极端降雨事件通常在夏季达到峰值,从而导致更多影响。
▲ abstract:
here, we identify a significant seasonal advance of intense tcs since the 1980s in most tropical oceans, with earlier-shifting rates of 3.7 and 3.2 days per decade for the northern and southern hemispheres, respectively. this seasonal advance of intense tcs is closely related to the seasonal advance of rapid intensification events, favoured by the observed earlier onset of favourable oceanic conditions. using simulations from multiple global climate models, large ensembles and individual forcing experiments, the earlier onset of favourable oceanic conditions is detectable and primarily driven by greenhouse gas forcing. the seasonal advance of intense tcs will increase the likelihood of intersecting with other extreme rainfall events, which usually peak in summer, thereby leading to disproportionate impacts.
地质学geology
highest terrestrial 3he/4he credibly from the core
来自地核的最高3he/4he比率
▲ 作者:f. horton, p. d. asimow, k. a. farley, j. curtice, m. d. kurz, j. blusztajn, j. a. biasi & x. m. boyes
▲ 链接:
https://www.nature.com/articles/s41586-023-06590-8
▲ 摘要:
在此,我们报告了在巴芬岛熔岩橄榄石的陆地火成岩中测量到的最高3he/4he比率(67.2±1.8倍的大气比率)。
我们认为,这些熔岩中极高的3he/4he氦可能来自地核。地核假说的可行性放松了长期以来基于与全球地幔柱相关的熔岩中惰性气体的限制,即太阳星云中的挥发性元素自吸积的早期阶段以来一直存在于地幔中。
▲ abstract:
here we report the highest magmatic 3he/4he ratio(67.2 ± 1.8 times the atmospheric ratio) yet measured in terrestrial igneous rocks, in olivines from baffin island lavas. we argue that the extremely high-3he/4he helium in these lavas might derive from earth’s core. the viability of the core hypothesis relaxes the long-standing constraint—based on noble gases in lavas associated with mantle plumes globally—that volatile elements from the solar nebula have survived in the mantle since the early stages of accretion.
moon-forming impactor as a source of earth’s basal mantle anomalies
月球形成大碰撞是地球基底地幔异常的一个成因
▲ 作者:qian yuan, mingming li et al.
▲ 链接:
https://www.nature.com/articles/s41586-023-06589-1
▲ 摘要:
在此,我们认为大型低剪切波速省可能代表了在形成月球的巨大撞击之后保存在原地球地幔中的忒伊亚地幔(tmm)的埋藏遗迹。我们的大碰撞模拟表明,忒伊亚地幔的一小部分可能被送到了原地球的固体下地幔。
根据忒伊亚地幔模型和观测到的月球较高的feo含量,我们发现tmm比原地球地幔密度大2.0%-3.5%。我们的地幔对流模型显示,撞击后几十公里大小的致密tmm团块随后会下沉并积聚成地球核心上类似低剪切波速省的热化学堆,并存在至今。
因此,剪切波速省可能是形成月球的巨大撞击的自然结果。由于巨大的撞击在行星吸积的最后阶段是常见的,类似的由撞击引起的地幔不均匀性也可能存在于其他行星体的内部。
▲ abstract:
here we show that llvps may represent buried relics of theia mantle material (tmm) that was preserved in proto-earth’s mantle after the moon-forming giant impact. our canonical giant-impact simulations show that a fraction of theia’s mantle could have been delivered to proto-earth’s solid lower mantle. we find that tmm is intrinsically 2.0–3.5% denser than proto-earth’s mantle based on models of theia’s mantle and the observed higher feo content of the moon. our mantle convection models show that dense tmm blobs with a size of tens of kilometres after the impact can later sink and accumulate into llvp-like thermochemical piles atop earth’s core and survive to the present day. the llvps may, thus, be a natural consequence of the moon-forming giant impact. because giant impacts are common at the end stages of planet accretion, similar mantle heterogeneities caused by impacts may also exist in the interiors of other planetary bodies.
特别声明:本文转载仅仅是出于传播信息的需要,并不意味着代表本网站观点或证实其内容的真实性;如其他媒体、网站或个人从本网站转载使用,须保留本网站注明的“来源”,并自负米乐app官网下载的版权等法律责任;作者如果不希望被转载或者联系转载稿费等事宜,请与我们接洽。