Nature, Volume 637 Issue 8045, 9 January 2025
《自然》第637卷，8045期，2025年1月9日
物理學(xué)Physics
Particle exchange statistics beyond fermions and bosons
超越費米子和玻色子的粒子交換統(tǒng)計
▲ 作者：Zhiyuan Wang & Kaden R. A. Hazzard
▲ 鏈接：https://www.nature.com/articles/s41586-024-08262-7
▲摘要：人們普遍認(rèn)為，在量子力學(xué)中，除了二維的任意子，只有費米子和玻色子兩種粒子交換統(tǒng)計。原則上，第二種例外被稱為非統(tǒng)計。它延伸到二維之外，被認(rèn)為在物理上等同于費米子和玻色子。
研究者證明了物理系統(tǒng)中可以存在與費米子或玻色子等價的非平凡準(zhǔn)統(tǒng)計量。這些新類型的相同粒子遵循廣義不相容原理，導(dǎo)致與任何自由費米子和玻色子系統(tǒng)不同的奇異自由粒子熱力學(xué)。
他們通過發(fā)展粒子的第二次量子化來表述其理論。該理論自然地包括精確可解的非相互作用理論，并結(jié)合了諸如局部性等物理約束。
然后，他們在一維和二維中構(gòu)建了一組精確可解的量子自旋模型，其中自由粒子以準(zhǔn)粒子的形式出現(xiàn)，其交換統(tǒng)計量可以被物理觀察到，且與費米子和玻色子明顯不同。這證明了在凝聚態(tài)系統(tǒng)中存在一種新型準(zhǔn)粒子的可能性，更有可能是以前未考慮過的基本粒子類型。
▲ Abstract：It is commonly believed that there are only two types of particle exchange statistics in quantum mechanics, fermions and bosons, with the exception of anyons in two dimensions. In principle, a second exception known as parastatistics, which extends outside two dimensions, has been considered but was believed to be physically equivalent to fermions and bosons. Here we show that non-trivial parastatistics inequivalent to either fermions or bosons can exist in physical systems. These new types of identical particle obey generalized exclusion principles, leading to exotic free-particle thermodynamics distinct from any system of free fermions and bosons. We formulate our theory by developing a second quantization of paraparticles that naturally includes exactly solvable non-interacting theories and incorporates physical constraints such as locality. We then construct a family of exactly solvable quantum spin models in one and two dimensions, in which free paraparticles emerge as quasiparticle excitations, and their exchange statistics can be physically observed and are notably distinct from fermions and bosons. This demonstrates the possibility of a new type of quasiparticle in condensed matter systems and—more speculatively—the potential for previously unconsidered types of elementary particle.
Excitons in the fractional quantum Hall effect
分?jǐn)?shù)量子霍爾效應(yīng)中的激子
▲ 作者：Naiyuan J. Zhang, Ron Q. Nguyen, Navketan Batra, Xiaoxue Liu, Kenji Watanabe, Takashi Taniguchi, D. E. Feldman & J. I. A. Li
▲ 鏈接：https://www.nature.com/articles/s41586-024-08274-3
▲摘要：激子，即電子和空穴的庫侖驅(qū)動束縛態(tài)，通常由整數(shù)電荷組成。然而，在受電荷分?jǐn)?shù)化影響的雙層系統(tǒng)中，可以出現(xiàn)一種更有趣的層間激子形式，其中在攜帶分?jǐn)?shù)電荷的組分之間發(fā)生配對。盡管對這些分?jǐn)?shù)激子有許多理論預(yù)測，但它們的實驗觀察仍未被探索。
研究者報道了分?jǐn)?shù)量子霍爾效應(yīng)態(tài)中激子對的輸運特征。通過探測這些激子的組成及其對潛在波函數(shù)的影響，他們發(fā)現(xiàn)了兩種新的物質(zhì)量子相。
其中一個可以被看作是總填充為1的激子凝聚的分?jǐn)?shù)對應(yīng)物；而另一個則涉及一種更不尋常的激子類型，它遵循非玻色子量子統(tǒng)計，挑戰(zhàn)玻色子激子的標(biāo)準(zhǔn)模型。
▲ Abstract：Excitons, Coulomb-driven bound states of electrons and holes, are typically composed of integer charges. However, in bilayer systems influenced by charge fractionalization, a more interesting form of interlayer exciton can emerge, in which pairing occurs between constituents that carry fractional charges. Despite numerous theoretical predictions for these fractional excitons, their experimental observation has remained unexplored. Here we report transport signatures of excitonic pairing in fractional quantum Hall effect states. By probing the composition of these excitons and their impact on the underlying wavefunction, we discover two new types of quantum phases of matter. One of these can be viewed as the fractional counterpart of the exciton condensate at a total filling of 1, whereas the other involves a more unusual type of exciton that obeys non-bosonic quantum statistics, challenging the standard model of bosonic excitons.
化學(xué)Chemistry
Emergence of a distinct mechanism of C–N bond formation in photoenzymes
光酶中C-N鍵形成的獨特機制的出現(xiàn)
▲ 作者：Felix C. Raps, Ariadna Rivas-Souchet, Chey M. Jones & Todd K. Hyster
▲ 鏈接：https://www.nature.com/articles/s41586-024-08138-w
▲摘要：由于氮雜環(huán)在小分子藥物和農(nóng)用化學(xué)品中無處不在，C-N鍵的形成對現(xiàn)代化學(xué)合成是不可或缺的。烯烴與未活化烯烴的氫胺化反應(yīng)是構(gòu)建這些鍵的原子經(jīng)濟策略。然而，當(dāng)制備完全取代的碳立體中心時，這些反應(yīng)很難呈現(xiàn)不對稱。
研究者報道了一種利用Baeyer-Villiger單加氧酶制備2,2-二取代吡咯烷的光酶烯烴氫胺化反應(yīng)。5輪蛋白質(zhì)工程獲得了一個突變體，提供了良好的產(chǎn)物收率和立體選擇性。
與依賴于胺或烯烴氧化形成C-N鍵的相關(guān)光化學(xué)氫胺反應(yīng)不同，這項研究利用了還原生成的苯基和氮孤對的空間相互作用。
這種反鍵相互作用降低了自由基的氧化電位，使電子轉(zhuǎn)移到黃素輔因子。實驗表明，酶微環(huán)境在實現(xiàn)創(chuàng)新的C-N鍵形成機制中是必不可少的，這在小分子催化中是沒有類似的。分子動力學(xué)模擬研究了酶活性位點的底物，進(jìn)一步支持了這一假設(shè)。
這項工作是非自然生物催化中新興機制的一個罕見例子。在這種機制中，酶可以獲得其單個組分所沒有的機制。我們的研究展示了利用蛋白質(zhì)工程增強緊急機制的潛力，為化學(xué)合成中未解決的挑戰(zhàn)提供獨特的機制解決方案。
▲ Abstract：C–N bond formation is integral to modern chemical synthesis owing to the ubiquity of nitrogen heterocycles in small-molecule pharmaceuticals and agrochemicals. Alkene hydroamination with unactivated alkenes is an atom-economical strategy for constructing these bonds. However, these reactions are challenging to render asymmetric when preparing fully substituted carbon stereocentres. Here we report a photoenzymatic alkene hydroamination to prepare 2,2-disubstituted pyrrolidines by a Baeyer–Villiger mono-oxygenase. Five rounds of protein engineering afforded a mutant, providing excellent product yield and stereoselectivity. Unlike related photochemical hydroaminations, which rely on the oxidation of the amine or alkene for C–N bond formation, this work exploits a through-space interaction of a reductively generated benzylic radical and the nitrogen lone pair. This antibonding interaction lowers the oxidation potential of the radical, enabling electron transfer to the flavin cofactor. Experiments indicate that the enzyme microenvironment is essential in enabling a innovative C–N bond formation mechanism with no parallel in small-molecule catalysis. Molecular dynamics simulations were performed to investigate the substrate in the enzyme active site, which further support this hypothesis. This work is a rare example of an emerging mechanism in non-natural biocatalysis in which an enzyme has access to a mechanism that its individual components do not. Our study showcases the potential of enhancing emergent mechanisms using protein engineering to provide unique mechanistic solutions to unanswered challenges in chemical synthesis.
Li2ZrF6-based electrolytes for durable lithium metal batteries
用于耐用鋰金屬電池的Li2ZrF6基電解質(zhì)
▲ 作者：Qingshuai Xu, Tan Li, Zhijin Ju, Guangxu Chen, Daiqi Ye, Geoffrey I. N. Waterhouse, Yingying Lu, Xuejun Lai, Guangmin Zhou, Lin Guo, Keyou Yan, Xinyong Tao, Hong Li & Yongcai Qiu
▲ 鏈接：https://www.nature.com/articles/s41586-024-08294-z
▲ 摘要：鋰（Li）金屬電池（MNB）是一種很有前途的高能量密度可充電電池。然而，由高活性鋰和非水電解質(zhì)之間的反應(yīng)形成的鋰枝晶導(dǎo)致了安全性問題和快速的容量衰減。開發(fā)可靠的固體電解質(zhì)界面對于實現(xiàn)高速率和長壽命的LMB至關(guān)重要，但在技術(shù)上仍然具有挑戰(zhàn)性。
研究者證明了在含有LiPF6的LMB碳酸鹽電解質(zhì)中添加過量的m-Li2ZrF6（單斜晶體的）納米顆粒，有助于在施加電壓的驅(qū)動下將大量的ZrF62 -離子釋放到電解質(zhì)中，轉(zhuǎn)化為t-Li2ZrF6（三方晶系），并在原位形成穩(wěn)定的固體-電解質(zhì)界面，具有高鋰離子電導(dǎo)率。
計算電鏡和低溫透射電鏡研究表明，富m-Li2ZrF6固電解質(zhì)界面的原位形成顯著增強了鋰離子的轉(zhuǎn)移，抑制了鋰枝晶的生長。結(jié)果表明，采用LiFePO4陰極、三維鋰碳陽極和Li2ZrF6基電解質(zhì)組裝的lmb在3000次循環(huán)后具有較高的容量保持率（>80.0%），大大提高了循環(huán)穩(wěn)定性。這一成就代表了領(lǐng)先的性能，因此在實際的高速率條件下，為耐用的LMB提供了可靠的基于Li2ZrF6的電解質(zhì)。
▲ Abstract：Lithium (Li) metal batteries (LMBs) are promising for high-energy-density rechargeable batteries. However, Li dendrites formed by the reaction between highly active Li and non-aqueous electrolytes lead to safety concerns and rapid capacity decay. Developing a reliable solid–electrolyte interphase is critical for realizing high-rate and long-life LMBs, but remains technically challenging. Here we demonstrate that adding excess m-Li2ZrF6 (monoclinic) nanoparticles to a commercial LiPF6-containing carbonate electrolyte of LMBs facilitates the release of abundant ZrF62– ions into the electrolyte driven by the applied voltage, converting to t-Li2ZrF6 (trigonal) and creating a stable solid–electrolyte interphase in situ with high Li-ion conductivity. Computational and cryogenic transmission electron microscopy studies revealed that the in situ formation of the t-Li2ZrF6-rich solid–electrolyte interphase markedly enhanced Li-ion transfer and suppressed the growth of Li dendrites. As a result, LMBs assembled with LiFePO4 cathodes (areal loading, 1.8/2.2 mAh cm-2), three-dimensional Li–carbon anodes (50- m-thick Li) and Li2ZrF6-based electrolyte displayed greatly improved cycling stability with high capacity retention (>80.0%) after 3,000 cycles (1C/2C rate). This achievement represents leading performance and, thus, delivers a reliable Li2ZrF6-based electrolyte for durable LMBs under practical high-rate conditions.
生命科學(xué)Life Science
Learning-associated astrocyte ensembles regulate memory recall
學(xué)習(xí)相關(guān)星形膠質(zhì)細(xì)胞群調(diào)節(jié)記憶回憶
▲ 作者：Michael R. Williamson, Wookbong Kwon, Junsung Woo, Yeunjung Ko, Ehson Maleki, Kwanha Yu, Sanjana Murali, Debosmita Sardar & Benjamin Deneen
▲ 鏈接：https://www.nature.com/articles/s41586-024-08170-w
▲摘要：記憶形成和回憶的物理表現(xiàn)是尚未解決的基本問題。在細(xì)胞水平上，被稱為記憶印痕的神經(jīng)元集合被學(xué)習(xí)事件激活，并控制記憶回憶。星形膠質(zhì)細(xì)胞靠近神經(jīng)元，參與一系列支持神經(jīng)傳遞和回路可塑性的活動。
此外，星形膠質(zhì)細(xì)胞表現(xiàn)出經(jīng)驗依賴的可塑性，盡管星形膠質(zhì)細(xì)胞的特定集合是否參與記憶回憶尚不清楚。
研究者發(fā)現(xiàn)學(xué)習(xí)事件誘導(dǎo)海馬星形膠質(zhì)細(xì)胞子集中的c-Fos表達(dá)，并隨后調(diào)節(jié)小鼠海馬回路的功能。學(xué)習(xí)事件后星形膠質(zhì)細(xì)胞群與c-Fos的交叉標(biāo)記表明它們與印跡神經(jīng)元密切相關(guān)，這些星形膠質(zhì)細(xì)胞群的重新激活刺激記憶回憶。
在分子水平上，學(xué)習(xí)相關(guān)星形膠質(zhì)細(xì)胞（LAA）群表現(xiàn)出核因子I-A的表達(dá)升高，其在該群體中的選擇性刪除抑制了記憶回憶。綜上所述，這一數(shù)據(jù)確定LAA集合是一種可塑性的形式，足以激發(fā)記憶回憶，并表明星形膠質(zhì)細(xì)胞是印跡的活躍成分。
▲ Abstract：The physical manifestations of memory formation and recall are fundamental questions that remain unresolved1. At the cellular level, ensembles of neurons called engrams are activated by learning events and control memory recall. Astrocytes are found in close proximity to neurons and engage in a range of activities that support neurotransmission and circuit plasticity. Moreover, astrocytes exhibit experience-dependent plasticity, although whether specific ensembles of astrocytes participate in memory recall remains obscure. Here we show that learning events induce c-Fos expression in a subset of hippocampal astrocytes, and that this subsequently regulates the function of the hippocampal circuit in mice. Intersectional labelling of astrocyte ensembles with c-Fos after learning events shows that they are closely affiliated with engram neurons, and reactivation of these astrocyte ensembles stimulates memory recall. At the molecular level, learning-associated astrocyte (LAA) ensembles exhibit elevated expression of nuclear factor I-A, and its selective deletion from this population suppresses memory recall. Taken together, our data identify LAA ensembles as a form of plasticity that is sufficient to provoke memory recall and indicate that astrocytes are an active component of the engram.
Foundation models for fast, label-free detection of glioma infiltration
快速、無標(biāo)記檢測膠質(zhì)瘤浸潤的基礎(chǔ)模型
▲ 作者：Akhil Kondepudi, Melike Pekmezci, Xinhai Hou, Katie Scotford, Cheng Jiang, Akshay Rao, Edward S. Harake, Asadur Chowdury, Wajd Al-Holou, Lin Wang, Aditya Pandey, Pedro R. Lowenstein, Maria G. Castro, Lisa Irina Koerner, Thomas Roetzer-Pejrimovsky, Georg Widhalm, Sandra Camelo-Piragua, Misha Movahed-Ezazi, Daniel A. Orringer, Honglak Lee, Christian Freudiger, Mitchel Berger, Shawn Hervey-Jumper & Todd Hollon
▲ 鏈接：https://www.nature.com/articles/s41586-024-08169-3
▲ 摘要：膠質(zhì)瘤治療的一個關(guān)鍵挑戰(zhàn)是在手術(shù)中檢測腫瘤浸潤以實現(xiàn)安全的最大切除。不幸的是，大多數(shù)膠質(zhì)瘤患者術(shù)后可安全切除殘余腫瘤，導(dǎo)致早期復(fù)發(fā)和生存率降低。研究者提出了一種快速（<10 s）和準(zhǔn)確檢測新鮮，未經(jīng)處理的手術(shù)組織中膠質(zhì)瘤浸潤的視覺基礎(chǔ)模型——FastGlioma。
該模型可在快速、無標(biāo)記的光學(xué)顯微鏡下使用大規(guī)模自我監(jiān)督（約400萬張圖像）進(jìn)行預(yù)訓(xùn)練，并進(jìn)行微調(diào)以輸出一個標(biāo)準(zhǔn)化的評分。該評分表明腫瘤浸潤程度在全片光學(xué)圖像中。
在一項前瞻性、多中心、國際彌漫性膠質(zhì)瘤患者檢測隊列（n = 220）中，F(xiàn)astGlioma能夠檢測并量化腫瘤浸潤程度，其在受試者工作特征曲線下的平均面積為92.1±0.9%。在一項頭部對頭部的前瞻性研究中，該模型在手術(shù)期間檢測腫瘤浸潤方面的表現(xiàn)優(yōu)于圖像引導(dǎo)和熒光引導(dǎo)輔助手段（n = 129）。
根據(jù)世界衛(wèi)生組織的定義，該模型在不同的患者人口統(tǒng)計、醫(yī)療中心和彌漫性膠質(zhì)瘤分子亞型中表現(xiàn)仍然很高。該模型在其他成人和兒童腦腫瘤診斷中顯示出零概率通用性，表明這一基礎(chǔ)模型有可能被用作指導(dǎo)腦腫瘤手術(shù)的通用輔助工具。這些發(fā)現(xiàn)代表了醫(yī)學(xué)基礎(chǔ)模型在釋放人工智能在癌癥患者護理中的作用方面的變革潛力。
▲ Abstract：A critical challenge in glioma treatment is detecting tumour infiltration during surgery to achieve safe maximal resection. Unfortunately, safely resectable residual tumour is found in the majority of patients with glioma after surgery, causing early recurrence and decreased survival. Here we present FastGlioma, a visual foundation model for fast (<10 s) and accurate detection of glioma infiltration in fresh, unprocessed surgical tissue. FastGlioma was pretrained using large-scale self-supervision (around 4 million images) on rapid, label-free optical microscopy, and fine-tuned to output a normalized score that indicates the degree of tumour infiltration within whole-slide optical images. In a prospective, multicentre, international testing cohort of patients with diffuse glioma (n = 220), FastGlioma was able to detect and quantify the degree of tumour infiltration with an average area under the receiver operating characteristic curve of 92.1 ± 0.9%. FastGlioma outperformed image-guided and fluorescence-guided adjuncts for detecting tumour infiltration during surgery by a wide margin in a head-to-head, prospective study (n = 129). The performance of FastGlioma remained high across diverse patient demographics, medical centres and diffuse glioma molecular subtypes as defined by the World Health Organization. FastGlioma shows zero-shot generalization to other adult and paediatric brain tumour diagnoses, demonstrating the potential for our foundation model to be used as a general-purpose adjunct for guiding brain tumour surgeries. These findings represent the transformative potential of medical foundation models to unlock the role of artificial intelligence in the care of patients with cancer.
本文鏈接：《自然》（20250109出版）一周論文導(dǎo)讀http://www.lensthegame.com/show-11-16214-0.html
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