1
|
Wu Q, Xu X, Qian H, Wang S, Zhu R, Yan Z, Ma H, Chen Y, Huang G. Active metamaterials for realizing odd mass density. Proc Natl Acad Sci U S A 2023; 120:e2209829120. [PMID: 37200363 PMCID: PMC10214168 DOI: 10.1073/pnas.2209829120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 03/29/2023] [Indexed: 05/20/2023] Open
Abstract
Solids built out of active components have exhibited odd elastic stiffness tensors whose active moduli appear in the antisymmetric part and which give rise to non-Hermitian static and dynamic phenomena. Here, we present a class of active metamaterial featured with an odd mass density tensor whose asymmetric part arises from active and nonconservative forces. The odd mass density is realized using metamaterials with inner resonators connected by asymmetric and programmable feed-forward control on acceleration and active forces along the two perpendicular directions. The active forces produce unbalanced off-diagonal mass density coupling terms, leading to non-Hermiticity. The odd mass is then experimentally validated through a one-dimensional nonsymmetric wave coupling where propagating transverse waves are coupled with longitudinal ones whereas the reverse is forbidden. We reveal that the two-dimensional active metamaterials with the odd mass can perform in either energy-unbroken or energy-broken phases separated by exceptional points along principal directions of the mass density. The odd mass density contributes to the wave anisotropy in the energy-unbroken phase and directional wave energy gain in the energy-broken phase. We also numerically illustrate and experimentally demonstrate the two-dimensional wave propagation phenomena that arise from the odd mass in active solids. Finally, the existence of non-Hermitian skin effect is discussed in which boundaries host an extensive number of localized modes. It is our hope that the emergent concept of the odd mass can open up a new research platform for mechanical non-Hermitian system and pave the ways for developing next-generation wave steering devices.
Collapse
Affiliation(s)
- Qian Wu
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| | - Xianchen Xu
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| | - Honghua Qian
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| | - Shaoyun Wang
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| | - Rui Zhu
- Department of Mechanics, Beijing Institute of Technology, Beijing100081, People’s Republic of China
| | - Zheng Yan
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| | - Hongbin Ma
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| | - Yangyang Chen
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Guoliang Huang
- Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO65211
| |
Collapse
|
2
|
Wilcken R, Nishida J, Triana JF, John-Herpin A, Altug H, Sharma S, Herrera F, Raschke MB. Antenna-coupled infrared nanospectroscopy of intramolecular vibrational interaction. Proc Natl Acad Sci U S A 2023; 120:e2220852120. [PMID: 37155895 PMCID: PMC10193936 DOI: 10.1073/pnas.2220852120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/05/2023] [Indexed: 05/10/2023] Open
Abstract
Many photonic and electronic molecular properties, as well as chemical and biochemical reactivities are controlled by fast intramolecular vibrational energy redistribution (IVR). This fundamental ultrafast process limits coherence time in applications from photochemistry to single quantum level control. While time-resolved multidimensional IR-spectroscopy can resolve the underlying vibrational interaction dynamics, as a nonlinear optical technique it has been challenging to extend its sensitivity to probe small molecular ensembles, achieve nanoscale spatial resolution, and control intramolecular dynamics. Here, we demonstrate a concept how mode-selective coupling of vibrational resonances to IR nanoantennas can reveal intramolecular vibrational energy transfer. In time-resolved infrared vibrational nanospectroscopy, we measure the Purcell-enhanced decrease of vibrational lifetimes of molecular vibrations while tuning the IR nanoantenna across coupled vibrations. At the example of a Re-carbonyl complex monolayer, we derive an IVR rate of (25±8) cm-1 corresponding to (450±150) fs, as is typical for the fast initial equilibration between symmetric and antisymmetric carbonyl vibrations. We model the enhancement of the cross-vibrational relaxation based on intrinsic intramolecular coupling and extrinsic antenna-enhanced vibrational energy relaxation. The model further suggests an anti-Purcell effect based on antenna and laser-field-driven vibrational mode interference which can counteract IVR-induced relaxation. Nanooptical spectroscopy of antenna-coupled vibrational dynamics thus provides for an approach to probe intramolecular vibrational dynamics with a perspective for vibrational coherent control of small molecular ensembles.
Collapse
Affiliation(s)
- Roland Wilcken
- Department of Physics, and JILA, University of Colorado, Boulder, CO80309
| | - Jun Nishida
- Department of Physics, and JILA, University of Colorado, Boulder, CO80309
| | - Johan F. Triana
- Department of Physics, Universidad de Santiago de Chile, Estación Central917022, Chile
| | - Aurelian John-Herpin
- Institute of Bioengineering, École Polytechnique Fédéral de Lausanne, Lausanne1015, Switzerland
| | - Hatice Altug
- Institute of Bioengineering, École Polytechnique Fédéral de Lausanne, Lausanne1015, Switzerland
| | - Sandeep Sharma
- Department of Chemistry, University of Colorado, Boulder, CO80309
| | - Felipe Herrera
- Department of Physics, Universidad de Santiago de Chile, Estación Central917022, Chile
- Millennium Institute for Research in Optics, Concepción4030000, Chile
| | - Markus B. Raschke
- Department of Physics, and JILA, University of Colorado, Boulder, CO80309
| |
Collapse
|
3
|
Yang Q, Miao Y, Banerjee P, Hourwitz MJ, Hu M, Qing Q, Iglesias PA, Fourkas JT, Losert W, Devreotes PN. Nanotopography modulates intracellular excitable systems through cytoskeleton actuation. Proc Natl Acad Sci U S A 2023; 120:e2218906120. [PMID: 37126708 PMCID: PMC10175780 DOI: 10.1073/pnas.2218906120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 03/21/2023] [Indexed: 05/03/2023] Open
Abstract
Cellular sensing of most environmental cues involves receptors that affect a signal-transduction excitable network (STEN), which is coupled to a cytoskeletal excitable network (CEN). We show that the mechanism of sensing of nanoridges is fundamentally different. CEN activity occurs preferentially on nanoridges, whereas STEN activity is constrained between nanoridges. In the absence of STEN, waves disappear, but long-lasting F-actin puncta persist along the ridges. When CEN is suppressed, wave propagation is no longer constrained by nanoridges. A computational model reproduces these experimental observations. Our findings indicate that nanotopography is sensed directly by CEN, whereas STEN is only indirectly affected due to a CEN-STEN feedback loop. These results explain why texture sensing is robust and acts cooperatively with multiple other guidance cues in complex, in vivo microenvironments.
Collapse
Affiliation(s)
- Qixin Yang
- Department of Physics, University of Maryland, College Park, MD20742
- Institute of Physical Science and Technology, University of Maryland, College Park, MD20742
| | - Yuchuan Miao
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD21205
| | - Parijat Banerjee
- Department of Physics & Astronomy, Johns Hopkins University, Baltimore, MD21218
| | - Matt J. Hourwitz
- Department of Chemistry & Biochemistry, University of Maryland, College Park, MD20742
| | - Minxi Hu
- School of Molecular Sciences, Arizona State University, Tempe, AZ85287
| | - Quan Qing
- Department of Physics, Arizona State University, Tempe, AZ85287
- Biodesign Institute, Arizona State University, Tempe, AZ85287
| | - Pablo A. Iglesias
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD21205
- Department of Electrical & Computer Engineering, Johns Hopkins University, Baltimore, MD21218
| | - John T. Fourkas
- Institute of Physical Science and Technology, University of Maryland, College Park, MD20742
- Department of Chemistry & Biochemistry, University of Maryland, College Park, MD20742
| | - Wolfgang Losert
- Department of Physics, University of Maryland, College Park, MD20742
- Institute of Physical Science and Technology, University of Maryland, College Park, MD20742
| | - Peter N. Devreotes
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD21205
| |
Collapse
|
4
|
Bendory T, Khoo Y, Kileel J, Mickelin O, Singer A. Autocorrelation analysis for cryo-EM with sparsity constraints: Improved sample complexity and projection-based algorithms. Proc Natl Acad Sci U S A 2023; 120:e2216507120. [PMID: 37094135 PMCID: PMC10161091 DOI: 10.1073/pnas.2216507120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 03/24/2023] [Indexed: 04/26/2023] Open
Abstract
The number of noisy images required for molecular reconstruction in single-particle cryoelectron microscopy (cryo-EM) is governed by the autocorrelations of the observed, randomly oriented, noisy projection images. In this work, we consider the effect of imposing sparsity priors on the molecule. We use techniques from signal processing, optimization, and applied algebraic geometry to obtain theoretical and computational contributions for this challenging nonlinear inverse problem with sparsity constraints. We prove that molecular structures modeled as sums of Gaussians are uniquely determined by the second-order autocorrelation of their projection images, implying that the sample complexity is proportional to the square of the variance of the noise. This theory improves upon the nonsparse case, where the third-order autocorrelation is required for uniformly oriented particle images and the sample complexity scales with the cube of the noise variance. Furthermore, we build a computational framework to reconstruct molecular structures which are sparse in the wavelet basis. This method combines the sparse representation for the molecule with projection-based techniques used for phase retrieval in X-ray crystallography.
Collapse
Affiliation(s)
- Tamir Bendory
- School of Electrical Engineering, Tel Aviv University, Tel Aviv69978, Israel
| | - Yuehaw Khoo
- Department of Statistics, University of Chicago, Chicago, IL60637
| | - Joe Kileel
- Department of Mathematics, Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, TX78712
| | - Oscar Mickelin
- Program in Applied and Computational Mathematics, Princeton University, Princeton, NJ08540
| | - Amit Singer
- Department of Mathematics, Program in Applied and Computational Mathematics, Princeton University, Princeton, NJ08540
| |
Collapse
|
5
|
Garcia RJ, Bu K, Jaffe A. Resource theory of quantum scrambling. Proc Natl Acad Sci U S A 2023; 120:e2217031120. [PMID: 37071685 PMCID: PMC10151511 DOI: 10.1073/pnas.2217031120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023] Open
Abstract
Quantum chaos has become a cornerstone of physics through its many applications. One trademark of quantum chaotic systems is the spread of local quantum information, which physicists call scrambling. In this work, we introduce a mathematical definition of scrambling and a resource theory to measure it. We also describe two applications of this theory. First, we use our resource theory to provide a bound on magic, a potential source of quantum computational advantage, which can be efficiently measured in experiment. Second, we also show that scrambling resources bound the success of Yoshida's black hole decoding protocol.
Collapse
Affiliation(s)
- Roy J Garcia
- Department of Physics, Harvard University, Cambridge, MA 02138
| | - Kaifeng Bu
- Department of Physics, Harvard University, Cambridge, MA 02138
| | - Arthur Jaffe
- Department of Physics, Harvard University, Cambridge, MA 02138
| |
Collapse
|
6
|
Lewis AM, Willard DJ, H. Manesh MJ, Sivabalasarma S, Albers SV, Kelly RM. Stay or Go: Sulfolobales Biofilm Dispersal Is Dependent on a Bifunctional VapB Antitoxin. mBio 2023; 14:e0005323. [PMID: 37036347 PMCID: PMC10127717 DOI: 10.1128/mbio.00053-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/14/2023] [Indexed: 04/11/2023] Open
Abstract
A type II VapB14 antitoxin regulates biofilm dispersal in the archaeal thermoacidophile Sulfolobus acidocaldarius through traditional toxin neutralization but also through noncanonical transcriptional regulation. Type II VapC toxins are ribonucleases that are neutralized by their proteinaceous cognate type II VapB antitoxin. VapB antitoxins have a flexible tail at their C terminus that covers the toxin's active site, neutralizing its activity. VapB antitoxins also have a DNA-binding domain at their N terminus that allows them to autorepress not only their own promoters but also distal targets. VapB14 antitoxin gene deletion in S. acidocaldarius stunted biofilm and planktonic growth and increased motility structures (archaella). Conversely, planktonic cells were devoid of archaella in the ΔvapC14 cognate toxin mutant. VapB14 is highly conserved at both the nucleotide and amino acid levels across the Sulfolobales, extremely unusual for type II antitoxins, which are typically acquired through horizontal gene transfer. Furthermore, homologs of VapB14 are found across the Crenarchaeota, in some Euryarchaeota, and even bacteria. S. acidocaldarius vapB14 and its homolog in the thermoacidophile Metallosphaera sedula (Msed_0871) were both upregulated in biofilm cells, supporting the role of the antitoxin in biofilm regulation. In several Sulfolobales species, including M. sedula, homologs of vapB14 and vapC14 are not colocalized. Strikingly, Sulfuracidifex tepidarius has an unpaired VapB14 homolog and lacks a cognate VapC14, illustrating the toxin-independent conservation of the VapB14 antitoxin. The findings here suggest that a stand-alone VapB-type antitoxin was the product of selective evolutionary pressure to influence biofilm formation in these archaea, a vital microbial community behavior. IMPORTANCE Biofilms allow microbes to resist a multitude of stresses and stay proximate to vital nutrients. The mechanisms of entering and leaving a biofilm are highly regulated to ensure microbial survival, but are not yet well described in archaea. Here, a VapBC type II toxin-antitoxin system in the thermoacidophilic archaeon Sulfolobus acidocaldarius was shown to control biofilm dispersal through a multifaceted regulation of the archaeal motility structure, the archaellum. The VapC14 toxin degrades an RNA that causes an increase in archaella and swimming. The VapB14 antitoxin decreases archaella and biofilm dispersal by binding the VapC14 toxin and neutralizing its activity, while also repressing the archaellum genes. VapB14-like antitoxins are highly conserved across the Sulfolobales and respond similarly to biofilm growth. In fact, VapB14-like antitoxins are also found in other archaea, and even in bacteria, indicating an evolutionary pressure to maintain this protein and its role in biofilm formation.
Collapse
Affiliation(s)
- April M. Lewis
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Daniel J. Willard
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Mohamad J. H. Manesh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Shamphavi Sivabalasarma
- Institute for Biology, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Sonja-Verena Albers
- Institute for Biology, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBBS, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Robert M. Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| |
Collapse
|
7
|
Abstract
Water (H2O) microdroplets are sprayed onto a magnetic iron oxide (Fe3O4) and Nafion-coated graphite mesh using compressed N2 or air as the nebulizing gas. The resulting splash of microdroplets enters a mass spectrometer and is found to contain ammonia (NH3). This gas-liquid-solid heterogeneous catalytic system synthesizes ammonia in 0.2 ms. The conversion rate reaches 32.9 ± 1.38 nmol s-1 cm-2 at room temperature without application of an external electric potential and without irradiation. Water microdroplets are the hydrogen source for N2 in contact with Fe3O4. Hydrazine (H2NNH2) is also observed as a by-product and is suspected to be an intermediate in the formation of ammonia. This one-step nitrogen-fixation strategy to produce ammonia is eco-friendly and low cost, which converts widely available starting materials into a value-added product.
Collapse
Affiliation(s)
- Xiaowei Song
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Chanbasha Basheer
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dammam 31261, Saudi Arabia
| | - Richard N Zare
- Department of Chemistry, Stanford University, Stanford, CA 94305
| |
Collapse
|
8
|
Osher S, Heaton H, Wu Fung S. A Hamilton-Jacobi-based proximal operator. Proc Natl Acad Sci U S A 2023; 120:e2220469120. [PMID: 36989305 PMCID: PMC10083605 DOI: 10.1073/pnas.2220469120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
First-order optimization algorithms are widely used today. Two standard building blocks in these algorithms are proximal operators (proximals) and gradients. Although gradients can be computed for a wide array of functions, explicit proximal formulas are known for only limited classes of functions. We provide an algorithm, HJ-Prox, for accurately approximating such proximals. This is derived from a collection of relations between proximals, Moreau envelopes, Hamilton-Jacobi (HJ) equations, heat equations, and Monte Carlo sampling. In particular, HJ-Prox smoothly approximates the Moreau envelope and its gradient. The smoothness can be adjusted to act as a denoiser. Our approach applies even when functions are accessible only by (possibly noisy) black box samples. We show that HJ-Prox is effective numerically via several examples.
Collapse
Affiliation(s)
- Stanley Osher
- Department of Mathematics, University of California, Los Angeles, CA 90095
| | | | - Samy Wu Fung
- Department of Applied Mathematics and Statistics, Colorado School of Mines, Golden, CO 80401
| |
Collapse
|