Recent ucsd_nano_ceng items

A highly utilized and practical lithium-sulfur positive electrode enabled in all-solid-state batteries

Fri, 8 May 2026 00:00:00 +0000

All-solid-state batteries using sulfur-based positive electrodes (cathodes) offer a cost-effective route to achieve high specific energy. However, low active material utilization and cycle life hinder performance. Here, we demonstrate a positive electrode design that employs sulfide solid-state electrolytes, where a high energy synthesis approach forms a metastable and ionically conductive interphase on the active material surface. This interphase facilitates high active material utilization and contributes capacity with cycling. We also show that tailoring active material particle sizes to the micron-scale improves rate performance and cycling stability. Structural analysis reveals that the substantial volume change of sulfur-based positive electrodes during operation can partially offset that of the negative electrodes, thereby mitigating internal mechanical stress. The combined design principles enable sulfur areal capacities up to 11 mAh cm-2 while maintaining stable cycling...

Acute Pharmacodynamic Effects of Oral Levodopa on Blood Pressure in Parkinson's Disease

Thu, 23 Apr 2026 00:00:00 +0000

BACKGROUND: Levodopa decreases blood pressure (BP) in persons with Parkinson's disease (PwP), but no pharmacodynamic studies integrating systemic levodopa concentration measurements have characterized its hypotensive effects. Understanding this relationship is clinically relevant for guiding therapeutic decisions, such as how aggressively to treat hypotension before initiating or increasing levodopa. In this pilot study, we aimed to determine the acute pharmacodynamic effects of oral immediate-release carbidopa/levodopa on BP in PwP. METHODS: PwP taking chronic oral carbidopa/levodopa with baseline BP ≥ 90/60 mmHg were recruited. Participants withheld antiparkinsonian medications overnight prior to the study visit and received carbidopa/levodopa immediate-release tablets at time 0. Capillary blood levodopa levels, seated BP measurements, and motor symptom assessments were performed at baseline and repeated every 10 min for 70-100 min. Non-compartmental pharmacokinetic parameters...

Simple Method for Photopatterning Commercial PDMS Using an Off-the-Shelf Photodeactivated Hydrosilylation Inhibitor

Thu, 9 Apr 2026 00:00:00 +0000

This paper describes a method of micropatterning commercial silicone elastomers using a photodeactivated hydrosilylation inhibitor. The method uses small doses of 365 nm light and is compatible with common platinum-cured formulations of poly(dimethylsiloxane) (PDMS). The hydrosilylation (cross-linking) inhibitor is a UV-sensitive emulsion composed of FeCl3 and a commercially available poly(ethylene oxide)-co-PDMS copolymer. This mixture enables selective solidification of exposed regions while preventing solidification in unexposed areas. This approach facilitates the creation of complex geometries while preserving the mechanical tunability, biocompatibility, and optical transparency of the base silicone. The patterned structures have been successfully used to fabricate high-resolution microfluidic devices and substrates for measuring the contractility of cardiac cells with integrated strain gauges. The process achieves feature sizes as small as 20 μm and is compatible with standard...

Ammonia Synthesis under Ambient Conditions: Insights into Water–Nitrogen–Magnetite Interfaces

Fri, 6 Mar 2026 00:00:00 +0000

New routes for transforming nitrogen into ammonia at ambient conditions would be a milestone toward an energy efficient and economically attractive production route in comparison to the traditional Haber-Bosch process. Recently, the synthesis of ammonia from water and nitrogen at room temperature and atmospheric pressure has been reported to be catalyzed by Fe₃O₄ at the air-water interface. By integrating ambient pressure X-ray photoelectron spectroscopy and ab initio molecular dynamics and free energy calculations, we investigate the underlying thermodynamic mechanisms governing ammonia and hydrazine formation at the water-Fe₃O₄-nanoparticle interface. We find that, unlike pure Fe₃O₄ where N₂ can only interact with a limited number of Fe sites, hydroxylated species introduce large and diverse adsorption geometries where N₂ can bind through either Fe sites or Fe-OH groups, each of which are...

33 Unresolved Questions in Nanoscience and Nanotechnology

Tue, 3 Mar 2026 00:00:00 +0000

Significant advances in science and engineering often emerge at the intersections of disciplines. Nanoscience and nanotechnology are inherently interdisciplinary, uniting researchers from chemistry, physics, biology, medicine, materials science, and engineering. This convergence has fostered novel ways of thinking and enabled the development of materials, tools, and technologies that have transformed both basic and applied research, as well as how we address critical societal challenges. In this Nano Focus, we pose and explore 33 questions whose answers could profoundly impact fields such as energy, electronics, the environment, optics, and medicine. These questions highlight the need for deeper foundational understanding, improved tools and techniques, and innovative applications─each with significant societal relevance. Together, they represent a global call-to-action for the scientific community.

Surface structure of water from soft X-ray second harmonic generation

Mon, 23 Feb 2026 00:00:00 +0000

The microscopic structure of water’s surface is crucial to many natural and industrial processes, but studying its hydrogen bond (H-bond) network directly remains challenging due to the required interfacial sensitivity of experimental techniques. By leveraging advances in flat liquid sheet microjets and terawatt-scale attosecond soft X-ray pulses from the LCLS X-ray free electron laser, we employed soft X-ray second harmonic generation (SXSHG) spectroscopy to examine the liquid water/vapor interface. SXSHG combines the elemental selectivity of X-ray spectroscopies with the surface selectivity of SHG and gives access to the electronic structure of interfacial species. Here, we show the SXSHG spectrum differs from bulk water’s X-ray absorption, with its peak shifted several eV, indicating a vastly different electronic environment at the interface as compared to the bulk. First-principles electronic structure calculations show the signal is highly sensitive to H-bond interactions,...

Bioprinting collagenase-responsive hydrogel for controlled release of cowpea mosaic virus immunotherapy.

Thu, 15 Jan 2026 00:00:00 +0000

In this work, we developed a collagenase-responsive hydrogel system to covalently load cancer immunotherapy candidate cowpea mosaic virus (CPMV) using 3D Digital Light Processing (DLP) bioprinting technology. CPMV was functionalized with norbornene groups (CPMV-NB), which was then bioprinted into hydrogels with 8-arm polyethylene glycol (PEG) norbornene and a collagenase-cleavable peptide via photoinduced thiol-ene click chemistry. This strategy enabled stable retention of CPMV-NB within the hydrogels and achieved controlled release of CPMV-NB triggered by collagenase. Furthermore, released CPMV-NB retained its immunogenicity to stimulate immune cells.

Lithium diffusion-controlled Li-Al alloy negative electrode for all-solid-state battery

Thu, 20 Nov 2025 00:00:00 +0000

Metal alloy negative electrodes are promising candidates for lithium all-solid-state batteries due to their high specific capacity and low cost. However, chemo-mechanical degradation and atomic transport limitations in the solid state remain unresolved challenges. Herein, we demonstrate a lithium-aluminum alloy negative electrode design (LixAl1, x = molar ratio of lithium to aluminum) based on a comprehensive understanding of the underlying diffusion mechanisms within the lithium-poor α (0 ≤ x ≤ 0.05) and lithium-rich β phases (0.95 ≤ x ≤ 1). The lithium-aluminum alloy negative electrodes with a higher lithium to aluminum ratio facilitate lithium migration through the β-LiAl phases, which serve as highly lithium-conductive channels with a lithium diffusion coefficient that is ten orders of magnitude higher than that of the α phase. In addition, a bulk dense negative electrode and an intimate negative electrode-electrolyte interface is demonstrated in the cross-sections...

Metastable sodium closo-hydridoborates for all-solid-state batteries with thick cathodes

Thu, 9 Oct 2025 00:00:00 +0000

Metastable sodium closo-hydridoborates for all-solid-state batteries with thick cathodes

PTPN22-CD45 dual phosphatase retrograde feedback enhances TCR signaling and autoimmunity

Mon, 15 Sep 2025 00:00:00 +0000

Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) is encoded by a gene strongly associated with lupus and other autoimmune diseases. PTPN22 regulates T cell receptor (TCR) signaling through dephosphorylation of the kinases lymphocyte-specific protein tyrosine kinase (LCK) and zeta-chain-associated protein kinase 70 (ZAP70). The regulation of PTPN22 remains poorly understood. Here, we identify PTPN22 Ser⁴⁴⁹ as a protein kinase A phosphorylation site, which is triggered by TCR engagement and is hyperphosphorylated in lupus peripheral blood cells. PTPN22 Ser⁴⁴⁹ phosphorylation selectively lowered the affinity of PTPN22 for ZAP70 versus LCK but also indirectly suppressed inhibitory LCK Tyr¹⁹² phosphorylation through a ZAP70-CD45 signaling axis. The resulting dephosphorylation of LCK Tyr¹⁹² not only enhanced TCR signaling but also modulated pathway activation downstream the TCR. In vivo loss of PTPN22 Ser⁴⁴⁹ phosphorylation...

Superionic Surface Li-Ion Transport in Carbonaceous Materials

Thu, 28 Aug 2025 00:00:00 +0000

Unlike Li-ion transport in the bulk of carbonaceous materials, little is known about Li-ion diffusion on their surface. In this study, we have discovered an ultrafast Li-ion transport phenomenon on the surface of carbonaceous materials with limited reversible Li insertion capacity and high surface area. An ionic conductivity of 18.1 mS cm^-1 at room temperature is observed in lithiated Ketjen black (KB), far exceeding those of most solid-state ion conductors. Theoretical calculations reveal low diffusion barriers for the surface Li species. As a result, lithiated KB functions effectively as an interlayer between Li and solid-state electrolytes (SSEs) to mitigate dendrite growth. Further, lithiated KB acts as a high-performance mixed ionic-electronic conductor and replaces solid electrolytes to enhance graphite anode performance, demonstrating full utilization with ∼85% capacity retention over 300 cycles. The discovery of this surface-mediated ultrafast Li-ion transport...

Tailoring Chloride Solid Electrolytes for Reversible Redox

Thu, 28 Aug 2025 00:00:00 +0000

Solid-state electrolytes enable next-generation batteries that can theoretically deliver higher energy densities while improving device safety. However, when fabricating cathodes for all-solid-state batteries, solid-state electrolytes must be combined with the active materials in high weight fractions in order to achieve sufficient ionic percolation within the cathode composite. This requirement drastically hinders the practicality of solid-state batteries as the solid-state electrolyte is conventionally designed to be electrochemically inactive and is effectively electrochemical "dead weight", lowering both the gravimetric and volumetric energy density of the cell. In this work, a well-known solid-state electrolyte, Na₂ZrCl₆, is modified by aliovalent substitution of inactive Zr⁴⁺ cations with redox-active M⁵⁺ (M = Nb or Ta) cations to create a series of Na_2-xM_xZr_1-xCl₆...

3D printed nerve guidance conduit for biologics‐free nerve regeneration and vascular integration

Thu, 14 Aug 2025 00:00:00 +0000

There is a clinical need for an effective nerve guidance conduit to treat peripheral nerve injuries. Many studies have explored different materials and active cues to guide neural regeneration, with some success. However, none have demonstrated a comparable or better functional recovery than the clinical standard autograft. Autografts are often insufficient for reconstruction of an injury to long nerves such as the sciatic or brachial plexus. Synthetic nerve guidance conduits (NGCs) have been investigated for these injuries to guide axonal regeneration and lead to functional recovery. We have designed a biologics-free hydrogel-based multi-channel conduit with defined microscale features to guide axonal outgrowth. To investigate extraneural vascular infiltration and its effects on functional recovery, we also designed a multi-microchannel conduit with defined regularly spaced micropores, orthogonal to the axon guidance channels. Using our custom-built Rapid Projection, Image-guided,...

Light-based vat-polymerization bioprinting

Thu, 14 Aug 2025 00:00:00 +0000

Light-based vat-polymerization bioprinting

3D Printed Nerve Guidance Conduit for Biologics-Free Nerve Regeneration and Vascular Integration

Thu, 14 Aug 2025 00:00:00 +0000

Thermo-electrochemical level-set topology optimization of a heat exchanger for lithium-ion batteries for electric vertical take-off and landing vehicles

Mon, 11 Aug 2025 00:00:00 +0000

Developing electric vertical take-off and landing vehicles (eVTOL) that can meet the demanding power and energy requirements entails significant challenges, one of which is due to the weight of the battery packs. To address this challenge, optimization techniques can be employed to achieve lightweight designs while satisfying thermal criteria. This study focuses on optimizing a battery heat exchanger housing a high-energy-densitycylindrical cell using the level-set topology optimization method. To accurately account for heat generation from battery electrochemistry, we investigate both a high-fidelity, the Doyle Fuller Newman (DFN) model, and a low-fidelity electrochemical model, the Single Particle Model (SPM), which are compared to experimental results for an eVTOL flight profile. The novelty of the proposed approach resides in the integration of the electrochemical models within a three-dimensional unsteady thermo-electrochemical topology optimization framework. The battery...

Earable Multimodal Sensing and Stimulation: A Prospective Toward Unobtrusive Closed-Loop Biofeedback

Thu, 17 Jul 2025 00:00:00 +0000

The human ear has emerged as a bidirectional gateway to the brain's and body's signals. Recent advances in around-the-ear and in-ear sensors have enabled the assessment of biomarkers and physiomarkers derived from brain and cardiac activity using ear-electroencephalography (ear-EEG), photoplethysmography (ear-PPG), and chemical sensing of analytes from the ear, with ear-EEG having been taken beyond-the-lab to outer space. Parallel advances in non-invasive and minimally invasive brain stimulation techniques have leveraged the ear's access to two cranial nerves to modulate brain and body activity. The vestibulocochlear nerve stimulates the auditory cortex and limbic system with sound, while the auricular branch of the vagus nerve indirectly but significantly couples to the autonomic nervous system and cardiac output. Acoustic and current mode stimuli delivered using discreet and unobtrusive earables are an active area of research, aiming to make biofeedback and bioelectronic medicine...

Accelerated data-driven materials science with the Materials Project

Tue, 15 Jul 2025 00:00:00 +0000

The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our efforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the...

Tuning the free energy of host–guest encapsulation by cosolvent

Mon, 23 Jun 2025 00:00:00 +0000

Supramolecular hosts create unique microenvironments which enable the tuning of reactions via steric confinement and electrostatics. It has been shown that "solvent shaping inside hydrophobic cavities" is an important thermodynamic driving force for guest encapsulation in the nanocage host. Here, we show that even small (5%) changes in the solvent composition can have a profound impact on the free energy of encapsulation. In a combined THz, NMR and ab initio MD study, we reveal that the preferential residing of a single DMSO molecule in the cavity upon addition of ≥5% DMSO results in a considerable change of ΔS from 63-76 cal mol^-1 K^-1 to 23-24 cal mol^-1 K^-1. This can be rationalized by reduction of the cavity volume due to the DMSO molecule which resides preferentially in the cavity. These results provide novel insights into the guest-binding interactions, emphasizing that the entropic driving force is notably influenced...

A responsive living material prepared by diffusion reveals extracellular enzyme activity of cyanobacteria

Thu, 22 May 2025 00:00:00 +0000

Stimuli-responsive engineered living materials (ELMs) can respond to environmental or biochemical cues and have broad utility in biological sensors and machines, but have traditionally been limited to biocompatible scaffolds. This is because they are typically made by mixing cells into a precursor solution before crosslinking. Here, we demonstrate a diffusion mechanism for incorporating cells of the cyanobacterium Synechococcus elongatus sp. PCC 7942 (S. elongatus) into nanoclay-poly-N-isopropylacrylamide (NC-PNIPAm), a hydrogel with a cytotoxic precursor, by exploiting its temperature-dependent shape-morphing behavior. Subsequent growth of S. elongatus caused a decrease in the bending curvature and stiffness (local Young's modulus) of NC-PNIPAm due to partial degradation by an unannotated enzyme. Creation and observation of this cyanobacteria-hydrogel ELM showcases a method for diffusing cells into a hydrogel as well as characterizing an extracellular enzyme.

Deep learning assisted high‐resolution microscopy image processing for phase segmentation in functional composite materials

Tue, 13 May 2025 00:00:00 +0000

In the domain of battery research, the processing of high-resolution microscopy images is a challenging task, as it involves dealing with complex images and requires a prior understanding of the components involved. The utilisation of deep learning methodologies for image analysis has attracted considerable interest in recent years, with multiple investigations employing such techniques for image segmentation and analysis within the realm of battery research. However, the automated analysis of high-resolution microscopy images for detecting phases and components in composite materials is still an underexplored area. This work proposes a novel workflow for FFT-based segmentation, periodic component detection and phase segmentation from raw high-resolution Transmission Electron Microscopy (TEM) images using a trained U-Net segmentation model. The developed model can expedite the detection of components and their phase segmentation, diminishing the temporal and cognitive demands...

In vivo periodontal ultrasound imaging via a hockey-stick transducer and comparison to periodontal probing: a proof-of-concept study

Thu, 8 May 2025 00:00:00 +0000

ObjectiveThe objective of this study is to evaluate a compact ultrasound transducer to image anatomical biomarkers for periodontal diagnosis of teeth, including difficult-to-reach posterior teeth.Materials and methodsA 9-MHz hockey-stick transducer was used to image 53 premolars, 30 molars, and 79 incisors and canines from 13 subjects. The alveolar bone crest (ABC), cementoenamel junction (CEJ), and gingival margin (GM) were identified by ultrasound imaging. The image-based distances between these anatomic landmarks were measured for iABC (ABC to CEJ), iGR (GM to CEJ) and iGH (ABC to GM). The measurements were compared to corresponding parameters obtained from clinical examination. The measurements were also used to assess periodontal health and were compared with clinical diagnosis.ResultsThe average iGR measurements were − 1.12 mm (i.e., 1.12 mm above the CEJ) for gingivitis and Stage I periodontitis, and − 0.56 mm for Stage III periodontitis, demonstrating a...

Engineering electro-crystallization orientation and surface activation in wide-temperature zinc ion supercapacitors

Thu, 24 Apr 2025 00:00:00 +0000

Matching the capacity of the anode and cathode is essential for maximizing electrochemical cell performance. This study presents two strategies to balance the electrode utilization in zinc ion supercapacitors, by decreasing dendritic loss in the zinc anode while increasing the capacity of the activated carbon cathode. The anode current collector was modified with copper nanoparticles to direct zinc plating orientation and minimize dendrite formation, improving the Coulombic efficiency and cycle life. The cathode was activated by an electrolyte reaction to increase its porosity and gravimetric capacity. The full cell delivered a specific energy of 192 ± 0.56 Wh kg−1 at a specific power of 1.4 kW kg−1, maintaining 84% capacity after 50,000 full charge-discharge cycles up to 2 V. With a cumulative capacity of 19.8 Ah cm−2 surpassing zinc ion batteries, this device design is particularly promising for high-endurance applications, including un-interruptible power supplies and energy-harvesting...

Metalloborospherene Analogs to Metallofullerene

Mon, 14 Apr 2025 00:00:00 +0000

Boron, the neighbor element to carbon in the periodic table, is characterized by unique electron deficiency that fosters multicenter delocalized bonding, contributing to its diverse chemistry. Unlike carbon cages (fullerenes), which preserve their structural integrity under endohedral or exohedral doping, larger boron cages (borospherenes) exhibit diverse structural configurations. These configurations can differ from those of pure boron cages and are stabilized by various metals through unique metal–boron bonding, resulting in a variety of metalloborospherenes. Due to boron’s electron deficiency, metalloborospherenes exhibit fascinating chemical bonding patterns that vary with cluster size and the type of metal dopants. This review paper highlights recent advancements in metalloborospherene research, drawing comparisons with metallofullerenes, and focuses on the use of transition metals, lanthanides, and actinides as dopants across various cage dimensions.

Structure Search with the Strategic Escape Algorithm

Mon, 14 Apr 2025 00:00:00 +0000

This work introduces the Strategic Escape (SE) algorithm, an approach that systematically ensures effective exploration of the potential energy surface during global minimum searches for atomic clusters. The SE algorithm prioritizes the escape from local minima prior to geometry optimization, leveraging a combination of randomized direction vectors, distance-based uniqueness criteria, and covalent bonding heuristics. These principles enhance structural diversity and computational efficiency by reducing redundant geometry optimizations. Additionally, a symmetry-guided seed generation method based on an adaptive polygon is proposed to provide diverse and physically realistic initial configurations. Together, these methods achieve a 2.3-fold improvement in computational efficiency compared to conventional Basin-Hopping approaches. The effectiveness of the SE algorithm is demonstrated through its application to boron, metal clusters, and binary-composition clusters, achieving rapid...

Anesthetic choice impacts mortality and bacterial clearance in a murine experimental pneumonia model

Fri, 11 Apr 2025 00:00:00 +0000

BackgroundAnimal models of infectious pneumonia often require the use of anesthetics, but their choice and impact on outcome is rarely discussed. This study investigates the impact of the most commonly used anesthetics on mortality and bacterial clearance in a murine model of Pseudomonas aeruginosa pneumonia.MethodsIsoflurane or ketamine/xylazine were determined to be the most commonly utilized anesthetics for murine pneumonia models. Mice were anesthetized with either ketamine/xylazine or isoflurane during intratracheal infection with P. aeruginosa strains PA14 or PA01. Mortality, bacterial clearance, and lung tissue damage were compared. Additional in vitro assays assessed the effects of ketamine on human whole blood killing, serum killing, and neutrophil functions (reactive oxygen species (ROS) production, neutrophil extracellular trap (NET) production, chemotaxis, and phagocytosis).ResultsMice anesthetized with ketamine/xylazine and infected with PA14 had significantly increased...

Boosted CO2 Photoreduction Performance by CdSe Nanoplatelets via Se Vacancy Engineering

Mon, 7 Apr 2025 00:00:00 +0000

2D metal-chalcogenide nanoplatelets (NPLs) exhibit promising photocatalysis properties due to their ultrathin morphology, high surface-to-volume ratio, and enhanced in-plane electron transport mobility. However, NPLs, especially cadmium chalcogenides, encounter challenges in CO₂ photoreduction due to insufficient solar energy utilization and fast recombination of photogenerated charge carriers. Defect engineering offers a potential solution but often encounters difficulties maintaining structural integrity, mechanical stability, and electrical conductivity. Herein, by taking two monolayers (2ML) CdSe NPLs as a model system, selenium (Se) vacancies confined in atomic layers can enhance charge separation and conductivity. A straightforward approach to create Se vacancies in various monolayers CdSe NPLs (2, 4, and 5ML) has been developed, enabling efficient CO₂ photoreduction with a 4-fold increase in CO generation compared to their defect-free counterparts....

TinkerModeller: An Efficient Tool for Building Biological Systems in Tinker Simulations

Wed, 2 Apr 2025 00:00:00 +0000

Polarizable force fields advance our understanding of electrostatic interactions in molecular systems; however, their widespread application is limited by the complexity of required molecular modeling. We here present TinkerModeller (TKM), a versatile software package designed to streamline the construction of biological systems in the Tinker molecular simulation software. The core functionality of TKM lies in its capacity to generate input files for complex molecular systems and facilitate the conversion from classical to polarizable force fields. With a user-friendly, standalone script, TKM provides an intuitive interface that supports users from molecular modeling through to postanalysis, creating a comprehensive platform for molecular dynamics simulations within Tinker. Furthermore, TKM includes an electric field (EF) postanalysis module, introducing a novel approach that employs charge methods and point charge approximations for efficient internal EF estimation. This module...

Characterization of Coulomb Interactions in Electron Transport Through a Single Hetero-Helicene Molecular Junction Using Scanning Tunneling Microscopy

Tue, 1 Apr 2025 00:00:00 +0000

Characterization of the structural and electron transport properties of single chiral molecules provides critical insights into the interplay between their electronic structure and electrochemical environments, providing broader implications given the significance of molecular chirality in chiroptical applications and pharmaceutical sciences. Here, we examined the topographic and electronic features of a recently developed chiral molecule, B,N-embedded double hetero[7]helicene, at the edge of Cu(100)-supported NaCl thin film with scanning tunneling microscopy and spectroscopy. An electron transport energy gap of 3.2 eV is measured, which is significantly larger than the energy difference between the highest occupied and the lowest unoccupied molecular orbitals given by theoretical calculations or optical measurements. Through first-principles calculations, we demonstrated that this energy discrepancy results from the Coulomb interaction between the tunneling electron and the molecule's...

Transcranial volumetric imaging using a conformal ultrasound patch

Fri, 21 Mar 2025 00:00:00 +0000

Accurate and continuous monitoring of cerebral blood flow is valuable for clinical neurocritical care and fundamental neurovascular research. Transcranial Doppler (TCD) ultrasonography is a widely used non-invasive method for evaluating cerebral blood flow1, but the conventional rigid design severely limits the measurement accuracy of the complex three-dimensional (3D) vascular networks and the practicality for prolonged recording2. Here we report a conformal ultrasound patch for hands-free volumetric imaging and continuous monitoring of cerebral blood flow. The 2 MHz ultrasound waves reduce the attenuation and phase aberration caused by the skull, and the copper mesh shielding layer provides conformal contact to the skin while improving the signal-to-noise ratio by 5 dB. Ultrafast ultrasound imaging based on diverging waves can accurately render the circle of Willis in 3D and minimize human errors during examinations. Focused ultrasound waves allow the recording of blood flow...

Skin-interfaced electronics: A promising and intelligent paradigm for personalized healthcare

Tue, 18 Mar 2025 00:00:00 +0000

Skin-interfaced electronics (skintronics) have received considerable attention due to their thinness, skin-like mechanical softness, excellent conformability, and multifunctional integration. Current advancements in skintronics have enabled health monitoring and digital medicine. Particularly, skintronics offer a personalized platform for early-stage disease diagnosis and treatment. In this comprehensive review, we discuss (1) the state-of-the-art skintronic devices, (2) material selections and platform considerations of future skintronics toward intelligent healthcare, (3) device fabrication and system integrations of skintronics, (4) an overview of the skintronic platform for personalized healthcare applications, including biosensing as well as wound healing, sleep monitoring, the assessment of SARS-CoV-2, and the augmented reality-/virtual reality-enhanced human-machine interfaces, and (5) current challenges and future opportunities of skintronics and their potentials in clinical...

A modular approach to enhancing cell membrane-coated nanoparticle functionality using genetic engineering

Mon, 10 Mar 2025 00:00:00 +0000

Since their initial development, cell membrane-coated nanoparticles (CNPs) have become increasingly popular in the biomedical field. Despite their inherent versatility and ability to enable complex biological applications, there is considerable interest in augmenting the performance of CNPs through the introduction of additional functionalities. Here we demonstrate a genetic-engineering-based modular approach to CNP functionalization that can encompass a wide range of ligands onto the nanoparticle surface. The cell membrane coating is engineered to express a SpyCatcher membrane anchor that can readily form a covalent bond with any moiety modified with SpyTag. To demonstrate the broad utility of this technique, three unique targeted CNP formulations are generated using different classes of targeting ligands, including a designed ankyrin repeat protein, an affibody and a single-chain variable fragment. In vitro, the modified nanoparticles exhibit enhanced affinity towards cell lines...

Development of a Sealed Rechargeable Li–SO2 Battery

Sat, 1 Mar 2025 00:00:00 +0000

Rechargeable Li-SO₂ batteries offer low-cost, high-energy density benefits and can leverage manufacturing processes for the existing primary version at a commercial scale. However, they have so far only been demonstrated in an "open-system" with continuous gas supply, preventing practical application. Here, the utilization and reversibility of SO₂ along with the lithium stability are addressed, all essential for long-life, high-energy batteries. The study discovers that high SO₂ utilization is achievable only from SO₂ dissolved in electrolytes between the lithium anode and carbon cathode. This results from a unique osmosis phenomenon where SO₂ consumption increases salt concentration, driving the influx of organic solvents rather than SO₂ from outside the current path. This insight leads to configure a bobbin-cell with all electrolytes between the electrodes, realizing nearly 70% of SO₂ utilization, > 12x...

Local-strain-induced CO2 adsorption geometries and electrochemical reduction pathway shift

Fri, 28 Feb 2025 00:00:00 +0000

Unravelling the influence of strain and geometric effects on the electrochemical reduction of carbon dioxide (CO₂RR) on Cu-based (or Pd-based) alloys remains challenging due to complex local microenvironment variables. Herein, we employ two PdCu alloys (nanoparticles and nanodendrites) to demonstrate how CO₂RR selectivity can shift from CO to HCOO^-. Despite sharing consistent phases, exposed crystal facets, and overall oxidative states, these alloys exhibit different local strain profiles due to their distinct geometries. By integrating experimental data, in-situ spectroscopy, and density functional theory calculations, we revealed that CO₂ prefers adsorption on tensile-strained areas with carbon-side geometry, following a *COOH-to-CO pathway. Conversely, on some compressive-strained regions induced by the dendrite-like morphology, CO₂ adopts an oxygen-side geometry, favoring an *OCHO-to-HCOO pathway due to the downshift...

Theoretical Investigation on One-Electron ϕ···ϕ Bonding in Diuranium Inverse Sandwich U2B6 Complex Enabled by a B6 Ring.

Fri, 28 Feb 2025 00:00:00 +0000

Traditional σ, π, and δ types of covalent chemical bonding have been extensively studied for nearly a century. In contrast, ϕ-type bonding involving nf (n = 4, 5) orbitals has received less attention due to their high contraction and minimal orbital overlap. Herein, we theoretically predict a singly occupied ϕ···ϕ bonding between two 5f orbitals, facilitated by B6 group orbitals in the hexa-boron diuranium inverse sandwich structure of U2B6. From ab initio quantum chemical calculations, the global minimum structure has a septuplet state with D6h symmetry. Chemical bonding analyses reveal that the 5f and 6d atomic orbitals of the two uranium atoms interact with the ligand orbitals of the central B6 ring, exhibiting favorable energy matching and symmetry compatibility to form delocalized σ-, π-, δ-, and ϕ-type bonding orbitals. Notably, even though the ϕ···ϕ bonding orbital is singly occupied, it still has a significant role in stability and cannot be overlooked. Furthermore, the...

Recent Development of Nanoparticle Platforms for Organophosphate Nerve Agent Detoxification

Thu, 27 Feb 2025 00:00:00 +0000

Poisoning by organophosphate (OP) nerve agents remains a pressing global threat due to their extensive use in chemical warfare agents and pesticides, potentially causing high morbidity and mortality worldwide. This urgent need for effective countermeasures has driven considerable interest in innovative detoxification approaches. Among these, nanoparticle technology stands out for its multifunctional potential and wide-ranging applications. This review highlights recent advancements in nanoparticle platforms developed for OP detoxification, focusing on five main types: inorganic nanoparticles, lipid-based nanoparticles, polymer-based nanoparticles, metal-organic framework nanoparticles, and cellular nanoparticles. For each platform, we discuss representative examples that illustrate how structural and functional properties enhance their effectiveness as nanocarriers, nanocatalysts, or nanoscavengers, ultimately enabling safe and efficient OP detoxification. This review aims to...

A Self-Amplifying Human Papillomavirus 16 Vaccine Candidate Delivered by Tobacco Mosaic Virus-Like Particles

Mon, 24 Feb 2025 00:00:00 +0000

Virus-like particles (VLPs) are naturally occurring delivery platforms with potential for mRNA vaccines that can be used as an alternative to lipid nanoparticles. Here we describe a self-amplifying mRNA vaccine based on tobacco mosaic virus (TMV) expressing a mutated E7 protein from human papillomavirus 16 (HPV16). E7 is an early gene that plays a central role in viral replication and the oncogenic transformation of host cells, but nononcogenic mutant E7 proteins can suppress this activity. Immunization studies involving the delivery of self-amplifying mutant E7 mRNA packaged with TMV coat proteins confirmed the elicitation of E7-specific IgG antibodies. Additional in vitro splenocyte proliferation and cytokine profiling assays indicated the activation of humoral and cellular immune responses. We conclude that TMV particles are suitable for the delivery of mRNA vaccines and can preserve their integrity and functionality in vitro and in vivo.

ABCD of IA: A multi-scale agent-based model of T cell activation in inflammatory arthritis

Mon, 17 Feb 2025 00:00:00 +0000

Biomaterial-based agents have been demonstrated to regulate the function of immune cells in models of autoimmunity. However, the complexity of the kinetics of immune cell activation can present a challenge in optimizing the dose and frequency of administration. Here, we report a model of autoreactive T cell activation, which are key drivers in autoimmune inflammatory joint disease. The model is termed a multi-scale Agent-Based, Cell-Driven model of Inflammatory Arthritis (ABCD of IA). Using kinetic rate equations and statistical theory, ABCD of IA simulated the activation and presentation of autoantigens by dendritic cells, interactions with cognate T cells and subsequent T cell proliferation in the lymph node and IA-affected joints. The results, validated with in vivo data from the T cell driven SKG mouse model, showed that T cell proliferation strongly correlated with the T cell receptor (TCR) affinity distribution (TCR-ad), with a clear transition state from homeostasis...

Chemical tools to define and manipulate interferon-inducible Ubl protease USP18

Mon, 17 Feb 2025 00:00:00 +0000

Ubiquitin-specific protease 18 (USP18) is a multifunctional cysteine protease primarily responsible for deconjugating the interferon-inducible ubiquitin-like modifier ISG15 from protein substrates. Here, we report the design and synthesis of activity-based probes (ABPs) that incorporate unnatural amino acids into the C-terminal tail of ISG15, enabling the selective detection of USP18 activity over other ISG15 cross-reactive deubiquitinases (DUBs) such as USP5 and USP14. Combined with a ubiquitin-based DUB ABP, the USP18 ABP is employed in a chemoproteomics screening platform to identify and assess inhibitors of DUBs including USP18. We further demonstrate that USP18 ABPs can be utilized to profile differential activities of USP18 in lung cancer cell lines, providing a strategy that will help define the activity-related landscape of USP18 in different disease states and unravel important (de)ISGylation-dependent biological processes.

Nanoscale Manipulation of Single-Molecule Conformational Transition through Vibrational Excitation

Fri, 14 Feb 2025 00:00:00 +0000

Controlling molecular actions on demand is a critical step toward developing single-molecule functional devices. Such control can be achieved by manipulating the interactions between individual molecules and their nanoscale environment. In this study, we demonstrate the conformational transition of a single pyrrolidine molecule adsorbed on a Cu(100) surface, driven by vibrational excitation through tunneling electrons using scanning tunneling microscopy. We identify multiple transition pathways between two structural states, each governed by distinct vibrational modes. The nuclear motions corresponding to these modes are elucidated through density functional theory calculations. By leveraging fundamental forces, including van der Waals interactions, dipole-dipole interactions, and steric hindrance, we precisely tune the molecule-environment coupling. This tuning enables the modulation of vibrational energies, adjustment of transition probabilities, and selection of the lowest-energy...

Molecular-Scale Insights into the Heterogeneous Interactions between an m‑Terphenyl Isocyanide Ligand and Noble Metal Nanoparticles

Thu, 13 Feb 2025 00:00:00 +0000

The structural and chemical properties of metal nanoparticles are often dictated by their interactions with molecular ligand shells. These interactions are highly material-specific and can vary significantly even among elements within the same group or materials with similar crystal structure. In this study, we surveyed the heterogeneous interactions between an m-terphenyl isocyanide ligand and Au and Ag nanoparticles (NPs) at the single-molecule limit. Specifically, we found that the ligation behavior with this molecule differs significantly between that of Au and AgNPs. Surface-enhanced Raman spectroscopy measurements revealed unique enhancement factors for two molecular vibrational modes between two metal surfaces, indicating different ligand binding geometries. Molecular-level characterization using scanning tunneling microscopy allowed us to directly visualize these variations between Ag and Au surfaces, which we assign as two distinct binding mechanisms. This molecular-scale...

Molecular-Scale Insights into the Heterogeneous Interactions between an m‑Terphenyl Isocyanide Ligand and Noble Metal Nanoparticles

Thu, 13 Feb 2025 00:00:00 +0000

Immunomodulatory Nanoparticles for Modulating Arthritis Flares

Tue, 11 Feb 2025 00:00:00 +0000

Disease-modifying drugs have improved the treatment for autoimmune joint disorders, such as rheumatoid arthritis, but inflammatory flares are a common experience. This work reports the development and application of flare-modulating poly(lactic-co-glycolic acid)-poly(ethylene glycol)-maleimide (PLGA-PEG-MAL)-based nanoparticles conjugated with joint-relevant peptide antigens, aggrecan_70-84 and type 2 bovine collagen_256-270. Peptide-conjugated PLGA-PEG-MAL nanoparticles encapsulated calcitriol, which acted as an immunoregulatory agent, and were termed calcitriol-loaded nanoparticles (CLNP). CLNP had a ∼200 nm hydrodynamic diameter with a low polydispersity index. In vitro, CLNP induced phenotypic changes in bone marrow derived dendritic cells (DC), reducing the expression of costimulatory and major histocompatibility complex class II molecules, and proinflammatory cytokines. Bulk RNA sequencing of DC showed that CLNP enhanced expression of Ctla4,...

Intelligent in-cell electrophysiology: Reconstructing intracellular action potentials using a physics-informed deep learning model trained on nanoelectrode array recordings

Thu, 30 Jan 2025 00:00:00 +0000

Intracellular electrophysiology is essential in neuroscience, cardiology, and pharmacology for studying cells’ electrical properties. Traditional methods like patch-clamp are precise but low-throughput and invasive. Nanoelectrode Arrays (NEAs) offer a promising alternative by enabling simultaneous intracellular and extracellular action potential (iAP and eAP) recordings with high throughput. However, accessing intracellular potentials with NEAs remains challenging. This study presents an AI-supported technique that leverages thousands of synchronous eAP and iAP pairs from stem-cell-derived cardiomyocytes on NEAs. Our analysis revealed strong correlations between specific eAP and iAP features, such as amplitude and spiking velocity, indicating that extracellular signals could be reliable indicators of intracellular activity. We developed a physics-informed deep learning model to reconstruct iAP waveforms from extracellular recordings recorded from NEAs and Microelectrode arrays...

A Pressure‐Sensitive, Repositionable Bioadhesive for Instant, Atraumatic Surgical Application on Internal Organs (Adv. Mater. 1/2025)

Thu, 30 Jan 2025 00:00:00 +0000

A Pressure‐Sensitive, Repositionable Bioadhesive for Instant, Atraumatic Surgical Application on Internal Organs (Adv. Mater. 1/2025)

Inhalable biohybrid microrobots: a non-invasive approach for lung treatment

Thu, 30 Jan 2025 00:00:00 +0000

Amidst the rising prevalence of respiratory diseases, the importance of effective lung treatment modalities is more critical than ever. However, current drug delivery systems face significant limitations that impede their efficacy and therapeutic outcome. Biohybrid microrobots have shown considerable promise for active in vivo drug delivery, especially for pulmonary applications via intratracheal routes. However, the invasive nature of intratracheal administration poses barriers to its clinical translation. Herein, we report on an efficient non-invasive inhalation-based method of delivering microrobots to the lungs. A nebulizer is employed to encapsulate picoeukaryote algae microrobots within small aerosol particles, enabling them to reach the lower respiratory tract. Post nebulization, the microrobots retain their motility (~55 μm s-1) to help achieve a homogeneous lung distribution and long-term retention exceeding five days in the lungs. Therapeutic efficacy is demonstrated...

Surface molecular engineering to enable processing of sulfide solid electrolytes in humid ambient air

Sat, 18 Jan 2025 00:00:00 +0000

Sulfide solid-state electrolytes (SSEs) are promising candidates to realize all solid-state batteries (ASSBs) due to their superior ionic conductivity and excellent ductility. However, their hypersensitivity to moisture requires processing environments that are not compatible with today’s lithium-ion battery manufacturing infrastructure. Herein, we present a reversible surface modification strategy that enables the processability of sulfide SSEs (e. g., Li6PS5Cl) under humid ambient air. We demonstrate that a long chain alkyl thiol, 1-undecanethiol, is chemically compatible with the electrolyte with negligible impact on its ion conductivity. Importantly, the thiol modification extends the amount of time that the sulfide SSE can be exposed to air with 33% relative humidity (33% RH) with limited degradation of its structure while retaining a conductivity of above 1 mS cm-1 for up to 2 days, a more than 100-fold improvement in protection time over competing approaches. Experimental...

Engineering the Cellular Microenvironment: Integrating Three-Dimensional Nontopographical and Two-Dimensional Biochemical Cues for Precise Control of Cellular Behavior