The inability to guide the nucleation locations of electrochemically deposited Li has long been considered the main factor limiting the utilization of high‐energy‐density Li‐metal batteries. In this ...study, an electrical conductivity gradient interfacial host comprising 1D high conductivity copper nanowires and nanocellulose insulating layers is used in stable Li‐metal anodes. The conductivity gradient system guides the nucleation sites of Li‐metal to be directed during electrochemical plating. Additionally, the controlled parameter of the intermediate layer affects the highly stable Li‐metal plating. The electrochemical behavior is confirmed through experiments associated with the COMSOL Multiphysics simulation data. The distributed Li‐ion reaction flux resulting from the controlled electrical conductivity enables stable cycling for more than 250 cycles at 1 mA cm−2. The gradient system effectively suppresses dendrite growth even at a high current density of 5 mA cm−2 and ensures Li plating and stripping with ultra‐long‐term stability. To demonstrate the high‐energy‐density full‐cell application of the developed anode, it is paired with the LiNi0.8Co0.1Mn0.1O2 cathode. The cells demonstrate a high capacity retention of 90% with an extremely high Coulombic efficiency of 99.8% over 100 cycles. These results shed light on the formidable challenges involved in exploiting the engineering aspects of high‐energy‐density Li‐metal batteries.
An electrical conductivity gradient interfacial host composed of simply fabricated 1D high conductivity copper nanowires and nanocellulose insulating layers shows stable lithium metal plating/stripping during electrochemical reaction. The conductivity gradient offers to guide the nucleation of lithium metal deposition, resulting in a high capacity retention of 90% with an extremely high Coulombic efficiency of 99.8% over 100 cycles as a full‐cell test.
Multiple sharp‐edged gold nanostars were efficiently assembled on nanopipette tips through electrostatic interactions for use as a potent intracellular hypoxia‐sensing Raman probe. Colloidal ...stability and surface immobilization were checked using scanning electron microscopy, light scattering, and zeta potential measurements. Site‐specific intracellular hypoxia levels can be estimated in vitro and in vivo using Raman lancets (RL). Distinct Raman spectral changes for the nitro‐(NO2) functional group of the redox marker 4‐nitrothiophenol (4NTP) can be quantified according to the intracellular oxygen (O2) content, ranging from 1 % to 10 %. Redox potential changes in mitochondrial respiration were also examined through serial injections of inhibitors. 3D‐cultured cells and in vivo tests were used to validate our method, and its application in the assessment of the aggressiveness of cancer cells by differentiating spectral changes between malignant and benign cells was demonstrated.
Twinkle, twinkle little stars: Multiple sharp‐edged gold nanostars were efficiently assembled on nanopipette tips through electrostatic interactions for use as a potent intracellular hypoxia‐sensing Raman probe.
Development of oxygen evolution reaction (OER) catalysts with reduced precious metal content while enhancing catalytic performance has been of pivotal importance in cost‐effective design of acid ...polymer electrolyte membrane water electrolyzers. Hollow multimetallic nanostructures with well‐defined facets are ideally suited for saving the usage of expensive precious metals as well as boosting catalytic performances; however, Ir‐based hollow nanocatalysts have rarely been reported. Here, a very simple synthetic scheme is reported for the preparation of hollow octahedral nanocages of Co‐doped IrCu alloy with readily tunable morphology and size. The Co‐doped IrCu octahedral nanocages show excellent electrocatalytic activity and long‐term durability for OER in acidic media. Notably, their OER activity represents one of the best performances among Ir‐based acidic OER catalysts.
Novel facet‐controlled Co‐doped IrCu octahedral hollow nanocages exhibit excellent electrocatalytic activity and durability toward the oxygen evolution reaction in acidic conditions.
Electromagnetic enhancement effects through localized surface plasmon resonance considerably amplify the intensity of incident light when molecules are positioned in the vicinity of miniscule ...nanogaps. The aggregation of plasmonic nanoparticles synthesized using bottom‐up methods has been extensively used to generate hot spots in solutions. These methods assist in obtaining non‐periodic plasmonic signals, because the realization of uniform nanogaps through particle aggregation is difficult. Nanostructured substrates with gaps of 20–100 nm have also been fabricated using the top‐down approach. However, the fabrication of smaller nanogap templates using these methods is difficult owing to high costs and low throughput. Therefore, a nanodimple array internalized with AuNPs is developed in this study to mitigate the challenges encountered in the bottom‐up and top‐down approaches. Precise nanogaps are generated by regularly internalizing AuNPs in the cavities of nanodimples through DNA hybridization. Simulations of the electric field distribution indicate that the incorporation of 80 nm‐sized AuNPs into a curved nanodimpled Au substrate generate high‐density volumetric hot spots within a detection volume, and result in a high plasmonic enhancement factor of 8.25 × 107. The tremendous potential of the proposed plasmonic platform as an SERS‐based biomedical diagnostic device is also verified.
Development of a sensitive surface‐enhanced Raman scattering detection platform, in which 80 nm‐sized gold nanoparticles are uniformly distributed in curved cavities of a nanodimpled Au substrate through DNA hybridization is presented.
Advances in microfluidic device miniaturization and system integration contribute to the development of portable, handheld, and smartphone-compatible devices. These advancements in diagnostics have ...the potential to revolutionize the approach to detect and respond to future pandemics. Accordingly, herein, recent advances in point-of-care testing (POCT) of coronavirus disease 2019 (COVID-19) using various microdevices, including lateral flow assay strips, vertical flow assay strips, microfluidic channels, and paper-based microfluidic devices, are reviewed. However, visual determination of the diagnostic results using only microdevices leads to many false-negative results due to the limited detection sensitivities of these devices. Several POCT systems comprising microdevices integrated with portable optical readers have been developed to address this issue. Since the outbreak of COVID-19, effective POCT strategies for COVID-19 based on optical detection methods have been established. They can be categorized into fluorescence, surface-enhanced Raman scattering, surface plasmon resonance spectroscopy, and wearable sensing. We introduced next-generation pandemic sensing methods incorporating artificial intelligence that can be used to meet global health needs in the future. Additionally, we have discussed appropriate responses of various testing devices to emerging infectious diseases and prospective preventive measures for the post-pandemic era. We believe that this review will be helpful for preparing for future infectious disease outbreaks.
T-cell exhaustion denotes a hypofunctional state of T lymphocytes commonly found in cancer, but how tumor cells drive T-cell exhaustion remains elusive. Here, we find T-cell exhaustion linked to ...overall survival in 675 hepatocellular carcinoma (HCC) patients with diverse ethnicities and etiologies. Integrative omics analyses uncover oncogenic reprograming of HCC methionine recycling with elevated 5-methylthioadenosine (MTA) and S-adenosylmethionine (SAM) to be tightly linked to T-cell exhaustion. SAM and MTA induce T-cell dysfunction in vitro. Moreover, CRISPR-Cas9-mediated deletion of MAT2A, a key SAM producing enzyme, results in an inhibition of T-cell dysfunction and HCC growth in mice. Thus, reprogramming of tumor methionine metabolism may be a viable therapeutic strategy to improve HCC immunity.
Metallic lithium (Li) and sodium (Na) anodes have received great attention as ideal anodes to meet the needs for high energy density batteries due to their highest theoretical capacities. Although ...many approaches have successfully improved the performances of Li or Na metal anodes, many of these methods are difficult to scale up and thus cannot be applied in the production of batteries in practice. In this work, we introduce nanocrevasses in a carbon fiber scaffold which can facilitate the penetration of molten alkali metal into a carbon scaffold by enhancing its wettability for Li/Na metal. The resulting alkali metal/carbon composites exhibit stable long-term cycling over hundreds of cycles. The facile synthetic method is enabled for scalable production using recycled metal waste. Thus, the addition of nanocrevasses to carbon fiber as a scaffold for alkali metals can generate environmentally friendly and cost-effective composites for practical electrode applications.
Staphylococcus aureus is a leading cause of nosocomial infections because of its resistance to diverse antibiotics. The formation of a biofilm is one of the mechanisms of drug resistance in S. ...aureus. The anti-biofilm abilities of 498 plant extracts against S. aureus were examined. Seventy-two plant extracts belonging to 59 genera and 38 families were found to significantly inhibit the formation of biofilms of S. aureus without affecting the growth of planktonic cells. The most active extract, from Alnus japonica, inhibited the formation of biofilms by three S. aureus strains by >70% at 20 μg ml
−1
. Transcriptional analyses showed that extract of A. japonica repressed the intercellular adhesion genes icaA and icaD most markedly. Quercetin and tannic acid are major anti-biofilm compounds in the extract of A. japonica. Additionally, the extract of A. japonica and its component compound quercetin, reduced hemolysis by S. aureus. This phenomenon was not observed in the treatment with tannic acid. This study suggests that various plant extracts, such as quercetin and tannic acid, could be used to inhibit the formation of recalcitrant biofilms of S. aureus.
The development of Pt‐free electrocatalysts for the hydrogen evolution reaction (HER) recently is a focus of great interest. While several strategies are developed to control the structural ...properties of non‐Pt catalysts and boost their electrocatalytic activities for the HER, the generation of highly reactive defects or interfaces by combining a metal with other metals, or with metal oxides/sulfides, can lead to notably enhanced catalytic performance. Herein, the preparation of cactus‐like hollow Cu2‐xS@Ru nanoplates (NPs) that contain metal/metal sulfide heterojunctions and show excellent catalytic activity and durability for the HER in alkaline media is reported. The initial formation of Ru islands on presynthesized Cu1.94S NPs, via cation exchange between three Cu+ ions and one Ru3+, induces the growth of the Ru phase, which is concomitant with the dissolution of the Cu1.94S nanotemplate, culminating in the formation of a hollow nanostructure with numerous thin Ru pillars. Hollow Cu2‐xS@Ru NPs exhibit a small overpotential of 82 mV at a current density of −10 mA cm−2 and a low Tafel slope of 48 mV dec−1 under alkaline conditions; this catalyst is among state‐of‐the‐art HER electrocatalysts in alkaline media. The excellent performance of hollow Cu2‐xS@Ru NPs originates from the facile dissociation of water in the Volmer step.
Cactus‐like hollow Cu2‐xS@Ru nanoplates greatly promote the alkaline hydrogen evolution reaction via the catalytic synergy between metal sulfide and metal phases.
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