Ozone Production Efficiencies in the Three Largest United States Cities from Airborne Measurements.

Despite ongoing reductions in emissions of ozone (O) precursors, nitrogen oxides (NO = NO + NO) and volatile organic compounds (VOCs), the three largest urban areas in the United States ─ New York City (NYC), Chicago, and Los Angeles (LA) ─ continue to exceed national air quality standards for O. Airborne measurements during the 2023 Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) campaign investigated nonlinear O photochemistry in these cities. We report mean ozone production efficiency (OPE), the enhancement ratio of O (= O + NO) to NO oxidation products, of 9 ± 4 (1σ), 6 ± 3, and 6 ± 3 ppbv ppbv in NYC, Chicago, and LA, respectively.

The cellular substrate of evolutionary novelty.

A major challenge in biology is comprehending how complex multicellular novelties evolve. Central to this problem is explaining how qualitatively new phenotypic traits - typically the focus of comparative developmental and macroevolutionary studies above the species level - can become established through population genetic processes. Here, we suggest that a resolution may be found by acknowledging the fundamental entities from which functional organismal phenotypes are constructed.

LSPR-Driven Dual-Mode Urea Sensor for Milk Adulteration Detection Using Gold Nanobipyramids and Upconversion Nanoparticles.

Ensuring food quality and safety is crucial, as the consumption of contaminated or substandard food poses serious risks to public health and imposes a substantial economic burden. Among various food safety concerns, milk adulteration with urea has emerged as a significant issue. This study presents a highly sensitive dual-mode colorimetric and fluorometric urea sensor for milk adulteration detection, utilizing enzymatic hydrolysis with Fenton-mediated plasmonic etching.

Large-scale high-density brain-wide neural recording in nonhuman primates.

High-density silicon probes have transformed neuroscience by enabling large-scale neural recordings at single-cell resolution. However, existing technologies have provided limited functionality in nonhuman primates (NHPs) such as macaques. In the present report, we describe the design, fabrication and performance of Neuropixels 1.

Asymmetric Total Synthesis of (-)-Crotonine G and (-)-Crotonolide D.

The first enantioselective total syntheses of crotonine G and crotonolide D are disclosed. The synthetic approach employs a SmI mediated ketyl radical cyclization to form the highly congested quaternary carbon at the center of these complex molecules. Following the furan introduction, the core structure of the natural product is constructed via oxidative olefin cleavage to install the unusual C-19 and C-20 oxidation.

Probing Isomers and Conformers by Cryogenic Ion Vibrational Spectroscopy: Deprotonated States of Valine and Aminovaleric Acid.

We present infrared photodissociation spectra of messenger-tagged, deprotonated valine and deprotonated aminovaleric acid, showing the difference in the vibrational spectra of isomers with the same functional groups. Through comparison of experimental results and density functional theory calculations, we find that the deprotonated states of both valine and aminovaleric acid adopt a configuration in which the carboxylate group forms a hydrogen bond with the amine group. Despite the similarities of the intramolecular hydrogen bonding, the spectra of the two molecules under study are sufficiently different to use the infrared signatures of the carboxylate and amine functional groups as a means to distinguish between them.

Inhomogeneous Quantum Quenches of Conformal Field Theory with Boundaries.

We develop a method to calculate generic time-dependent correlation functions for inhomogeneous quantum quenches in (1+1)-dimensional conformal field theory (CFT) induced by sudden Hamiltonian deformations that modulate the energy density inhomogeneously. Our Letter particularly focuses on the effects of spatial boundaries, which have remained unresolved by previous analytical methods. For generic postquench Hamiltonian, we develop a generic method to calculate the correlations by mirroring the system, which otherwise are Euclidean path integrals in complicated spacetime geometries difficult to calculate.

Ten new insights in climate science 2024.

The years 2023 and 2024 were characterized by unprecedented warming across the globe, underscoring the urgency of climate action. Robust science advice for decision makers on subjects as complex as climate change requires deep cross- and interdisciplinary understanding. However, navigating the ever-expanding and diverse peer-reviewed literature on climate change is enormously challenging for individual researchers.

Architected Liquid Crystal Elastomer Lattices with Programmable Energy Absorption.

Architected LCE lattices are fabricated with flow-induced alignment via direct ink writing and systematically characterized their shape morphing, stiffness, and energy absorption behavior across strain rates spanning six orders of magnitude from 10 to 10 s. It is shown that architected liquid crystal elastomer (LCE) lattices exhibit superior energy absorption compared to their non-mesogenic (silicone) counterparts. Importantly, the LCE-to-silicone energy absorption ratios are up to 18-fold higher at the highest strain rate tested.

Identification of key steps in the evolution of anaerobic methanotrophy in Methanovorans (ANME-3) archaea.

Despite their large environmental impact and multiple independent emergences, the processes leading to the evolution of anaerobic methanotrophic archaea (ANME) remain unclear. This work uses comparative metagenomics of a recently evolved but understudied ANME group, " Methanovorans" (ANME-3), to identify evolutionary processes and innovations at work in ANME, which may be obscured in earlier evolved lineages. We identified horizontal transfer of homologs and convergent evolution in carbon and energy metabolic genes as potential early steps in evolution.

General Quantum Alchemical Free Energy Simulations via Hamiltonian Interpolation.

We present an implementation of alchemical free energy simulations at the quantum mechanical level by directly interpolating the electronic Hamiltonian. The method is compatible with any level of electronic structure theory and requires only one quantum calculation for each molecular dynamics step in contrast to multiple energy evaluations that would be needed when interpolating the ground-state energies. We demonstrate the correctness and applicability of the technique by computing alchemical free energy changes of gas-phase molecules, with both nuclear and electron creation/annihilation.

Dental development in the tropical gar (Atractosteus tropicus) and the evolution of vertebrate dentitions.

Background: Dentitions have diversified enormously during vertebrate evolution, involving reductions, modifications, or allocations to prey seizing and processing regions. A combination of ancient and novel features related to dental and oropharyngeal apparatuses is found in extant lineages of non-teleost fishes, such as the gars. While relevant to evolutionary-developmental studies, gars have largely been overlooked regarding how their dentition arises, thus leaving our comprehension of the evolutionary history of vertebrate dentitions incomplete.

Wound management materials and technologies from bench to bedside and beyond.

Chronic wounds represent a major global health problem, causing staggering economic and social burdens. The pursuit of effective wound healing strategies demands a multidisciplinary approach, and advances in material sciences and bioengineering have paved the way for the development of novel wound healing biomaterials and technologies. In this Review, we provide an overview of the history and challenges of wound management and highlight the current state-of-the-art in wound healing biomaterials alongside the emerging technologies poised to transform the landscape of chronic wound treatment and monitoring.

Statistical mechanics of a two-dimensional quasistatic granular pile: Thermodynamics and constitutive relations.

From the onset of the subject, granular media have been defying the toolkit of statistical mechanics, thus hindering our understanding of their thermodynamic and stress-strain constitutive properties and making this state of matter one of the key remaining mysteries in science. In the present work, we offer a resolution to this problem with the help of an idealized model-a collection of two-dimensional identical balls forming a static granular pile in the gravity field-that allows us to develop appropriate thermodynamics and constitutive relations from the first principles a posteriori justified via the statistical analysis of pile realizations. Besides the uncertainty due to the rough substrate on which the pile is built, we uncover another one due to ambiguities occurring in the positions of some interior balls.

Potential of CO sequestration through accelerated weathering of limestone on ships.

Calcium carbonate dissolution is the dominant negative feedback in the ocean for neutralizing the acidity from rising atmospheric carbon dioxide. Mimicking this natural process, the accelerated weathering of limestone (AWL) can store carbon as bicarbonate in the ocean for tens of thousands of years. Here, we evaluate the potential of AWL on ships as a carbon sequestration approach.

Reactivation of an embryonic cardiac neural crest transcriptional profile during zebrafish heart regeneration.

During vertebrate development, the heart primarily arises from mesoderm, with crucial contributions from cardiac neural crest (CdNC) cells that migrate to the heart and form a variety of cardiovascular derivatives. Here, by integrating bulk and single cell RNA-seq with ATAC-seq, we identify a gene regulatory subcircuit specific to migratory cardiac crest cells composed of key transcription factors and Notably, we show that cells expressing the canonical neural crest gene are essential for proper cardiac regeneration in adult zebrafish. Furthermore, expression of all transcription factors from the migratory cardiac crest gene subcircuit are reactivated after injury at the wound edge.

Deformed One-Dimensional Covalent Organic Polymers for Enhanced CO Electroreduction to Methanol.

Spatially arranged molecular catalysts in polymeric frameworks, typically in a layered structure, are emerging strategies to mitigate the molecular aggregation and improve the catalytic performance. However, the effect of local coordination induced by polymerization remains underexplored. Here, we develop one-dimensional cobalt-tetra-amino-phthalocyanine-based covalent organic polymers (1D-COP) for the electrochemical CO reduction reaction (CORR).

High-resolution profiling reveals coupled transcriptional and translational regulation of transgenes.

Concentrations of RNAs and proteins provide important determinants of cell fate. Robust gene circuit design requires an understanding of how the combined actions of individual genetic components influence both messenger RNA (mRNA) and protein levels. Here, we simultaneously measure mRNA and protein levels in single cells using hybridization chain reaction Flow-FISH (HCR Flow-FISH) for a set of commonly used synthetic promoters.

Robust Laser-Induced Graphene-Boron-Doped Diamond Nanowall Hybrid Nanostructures with Enhanced Field Electron Emission Performance for Microplasma Illumination Devices.

This investigation introduces a scalable fabrication method for laser-induced graphene (LIG)-boron-doped diamond nanowall (BDNW) hybrid nanostructures, designed for field electron emission (FEE) cathode materials in microplasma illumination (μPI) devices. The two-step process involves fabricating BDNWs via microwave plasma-enhanced chemical vapor deposition, followed by drop-casting BDNW dispersion onto polyimide foils to create LIG-BDNW hybrid nanostructures. Topographic studies reveal that BDNWs on LIG boosts surface area and prevent graphene restacking.

The Mycobacterium tuberculosis Transposon Sequencing Database (MtbTnDB): A Large-Scale Guide to Genetic Conditional Essentiality.

Characterizing genetic essentiality across various conditions is fundamental for understanding gene function. Transposon sequencing (TnSeq) is a powerful technique to generate genome-wide essentiality profiles in bacteria and has been extensively applied to Mycobacterium tuberculosis (Mtb). Dozens of TnSeq screens have yielded valuable insights into the biology of Mtb in vitro, inside macrophages, and in model host organisms.

Methane-powered sea spiders: Diverse, epibiotic methanotrophs serve as a source of nutrition for deep-sea methane seep .

Methane seeps harbor uncharacterized animal-microbe symbioses with unique nutritional strategies. Three undescribed sea spider species (family Ammotheidae; genus ) endemic to methane seeps were found along the eastern Pacific margin, from California to Alaska, hosting diverse methane- and methanol-oxidizing bacteria on their exoskeleton. δC tissue isotope values of in situ specimens corroborated methane assimilation (-45‰, on average).

Concise total synthesis of the cage-like sesquiterpenoid (+)-daphnepapytone A.

We report a non-biomimetic total synthesis of (+)-daphnepapytone A, an unprecedented member of the guaiane-derived sesquiterpenoids that displays moderate inhibitory activity against α-glycosidase (IC = 159 ± 2.1 μM) and possesses a highly strained bridging cyclobutane motif. Our approach provided expedient access to the tetracyclic core of (+)-daphnepapytone A through an intramolecular allenyl thermal [2 + 2] cycloaddition and a Pauson-Khand reaction with a labile cyclobutane.

Combustion Resistant Borohydrides and Their Chemical Interactions with Li-Metal Surfaces: An Experimental and Theoretical Study.

Borohydrides are important molecular entities for a myriad of applications from organic synthesis to components of functional materials and devices. All borohydrides have been thought to be susceptible to spontaneous ignition when exposed to a flame. Herein we demonstrate that this is not always true by identifying several borohydride rich materials that are resistant to combustion when contacted with a torch.

Impact of glacial meltwater on phytoplankton biomass along the Western Antarctic Peninsula.

The Western Antarctic Peninsula is undergoing rapid environmental change. Regional warming is causing increased glacial meltwater discharge, but the ecological impact of this meltwater over large spatiotemporal scales is not well understood. Here, we leverage 20 years of remote sensing data, reanalysis products, and field observations to assess the effects of sea surface glacial meltwater on phytoplankton biomass and highlight its importance as a key environmental driver for this region's productive ecosystem.