Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the ...most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in biomedical applications. AgNPs play an important role in nanoscience and nanotechnology, particularly in nanomedicine. Although several noble metals have been used for various purposes, AgNPs have been focused on potential applications in cancer diagnosis and therapy. In this review, we discuss the synthesis of AgNPs using physical, chemical, and biological methods. We also discuss the properties of AgNPs and methods for their characterization. More importantly, we extensively discuss the multifunctional bio-applications of AgNPs; for example, as antibacterial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anti-cancer agents, and the mechanism of the anti-cancer activity of AgNPs. In addition, we discuss therapeutic approaches and challenges for cancer therapy using AgNPs. Finally, we conclude by discussing the future perspective of AgNPs.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Organic–inorganic hybrid perovskite solar cells have resulted in tremendous interest in developing next generation photovoltaics due to high record efficiency exceeding 22%. For inverted structure ...perovskite solar cells, the hole extraction layers play a significant role in achieving efficient and stable perovskite solar cell by modifying charge extraction, interfacial recombination losses, and band alignment. Here, cesium doped NiOx is selected as a hole extraction layer to study the impact of Cs dopant on the optoelectronic properties of NiOx and the photovoltaic performance. Cs doped NiOx films are prepared by a simple solution‐based method. Both doped and undoped NiOx films are smooth and highly transparent, while the Cs doped NiOx exhibits better electron conductivity and higher work function. Therefore, Cs doping results in a significant improvement in the performance of NiOx‐based inverted planar perovskite solar cells. The best efficiency of Cs doped NiOx devices is 19.35%, and those devices show high stability as well. The improved efficiency in devices with Cs:NiOx is attributed to a significant improvement in the hole extraction and better band alignment compared to undoped NiOx. This work reveals that Cs doped NiOx is very promising hole extraction material for high and stable inverted perovskite solar cells.
Cesium doping of NiOx enhances the conductivity of the oxide film and the hole extraction from the perovskite film in inverted planar perovskite solar cells. Significantly improved photovoltaic performance is obtained with the best efficiencies of 16.04% and 19.35% for NiOx and Cs:NiOx, respectively. The devices exhibit negligible hysteresis and good stability.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Carbon dots (Cdots) are an important probe for imaging and sensing applications because of their fluorescence property, good biocompatibility, and low toxicity. However, complex procedures and strong ...acid treatment are often required and Cdots suffer from low photoluminescence (PL) emission. Herein, a facile and general strategy using carbonization of precursors and then extraction with solvents is proposed for the preparation of nitrogen‐doped Cdots (N‐Cdots) with 3‐(3,4‐dihydroxyphenyl)‐L‐alanine (L‐DOPA), L‐histidine, and L‐arginine as precursor models. After they are heated, the precursors become carbonized. Nitrogen‐doped Cdots are subsequently extracted into N,N′‐dimethylformamide (DMF) from the carbogenic solid. A core–shell structure of Cdots with a carbon core and the oxygen‐containing shell was observed. Nitrogen has different forms in N‐Cdots and oxidized N‐Cdots. The doped nitrogen and low oxidation level in N‐Cdots improve their emission significantly. The N‐Cdots show an emission with a nitrogen‐content‐dependent intensity and Cdot‐size‐dependent emission‐peak wavelength. Imaging of HeLa cells, a human cervical cancer cell line, and HepG2 cells, a human hepatocellular liver carcinoma line, was observed with high resolution using N‐Cdots as a probe and validates their use in imaging applications and their multicolor property in the living cell system.
Going dotty: A facile and general strategy involving the carbonization of precursors and their subsequent extraction with solvents is proposed for the preparation of nitrogen‐doped carbon dots (N‐Cdots) with multicolor emission (see figure). The emission mechanism of the Cdots was studied. Multicolor photoluminescence was validated in living cell systems.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Silver nanoparticles (AgNPs) have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their ...unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with future perspectives on research into AgNPs.
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The phase-matching condition is a key aspect in nonlinear wavelength conversion processes, which requires the momenta of the photons involved in the processes to be conserved. Conventionally, ...nonlinear phase matching is achieved using either birefringent or periodically poled nonlinear crystals, which requires careful dispersion engineering and is usually narrowband. In recent years, metasurfaces consisting of densely packed arrays of optical antennas have been demonstrated to provide an effective optical momentum to bend light in arbitrary ways. Here, we demonstrate that gradient metasurface structures consisting of phased array antennas are able to circumvent the phase-matching requirement in on-chip nonlinear wavelength conversion. We experimentally demonstrate phase-matching-free second harmonic generation over many coherent lengths in thin film lithium niobate waveguides patterned with the gradient metasurfaces. Efficient second harmonic generation in the metasurface-based devices is observed over a wide range of pump wavelengths (λ = 1580-1650 nm).
Droplet impacting and bouncing off solid surface plays a vital role in various biological/physiological processes and engineering applications. However, due to a lack of accurate control of force ...transmission, the maneuver of the droplet movement and energy conversion is rather primitive. Here we show that the translational motion of an impacting droplet can be converted to gyration, with a maximum rotational speed exceeding 7300 revolutions per minute, through heterogeneous surface wettability regulation. The gyration behavior is enabled by the synergetic effect of the asymmetric pinning forces originated from surface heterogeneity and the excess surface energy of the spreading droplet after impact. The findings open a promising avenue for delicate control of liquid motion as well as actuating of solids.
We investigate the one-bit MIMO (1b-MIMO) radar that performs one-bit sampling with a time-varying threshold in the temporal domain and employs compressive sensing in the spatial and Doppler domains. ...The goals are to significantly reduce the hardware cost, energy consumption, and amount of stored data. The joint angle and Doppler frequency estimations from noisy onebit data are studied. By showing that the effect of noise on one-bit sampling is equivalent to that of sparse impulsive perturbations, we formulate the one-bit ℓ 1 -regularized atomic-norm minimization (1b-ANM-L1) problem to achieve gridless parameter estimation with high accuracy. We also develop an iterative method for solving the 1b-ANM-L1 problem via the alternating direction method of multipliers. The Cramér-Rao bound (CRB) of the 1b-MIMO radar is analyzed, and the analytical performance of one-bit sampling with two different threshold strategies is discussed. Numerical experiments are presented to show that the 1b-MIMO radar can achieve high-resolution parameter estimation with a largely reduced amount of data.
Abstract
The prosperity of the lithium‐ion battery market is dialectically accompanied by the depletion of corresponding resources and the accumulation of spent batteries. It is an urgent priority to ...develop green and efficient battery recycling strategies for helping ease resources and environmental pressures at the current stage. Here, we propose a mild and efficient lithium extracting strategy based on potential controllable redox couples. Active lithium in the spent battery without discharging is extracted using a series of tailored aprotic solutions comprised of polycyclic aromatic hydrocarbons and ethers. This ensures a safe yet efficient recycling process with nearly ≈100 % lithium recovery. We further investigate the Li
+
‐electron concerted redox reactions and the effect of solvation structure on kinetics during the extraction, and broaden the applicability of the Li‐PAHs solution. This work can stimulate new inspiration for designing novel solutions to meet efficient and sustainable demands in recycling batteries.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Sialon ceramics were prepared by the nitridation of Si, Al and Al
2
O
3
powders with the transition metals (Fe, Co, Ni) catalysts. The phase composition, microstructure and mechanical properties of ...specimens were studied. Compared with the catalyst-free specimen, the addition of Fe, Co and Ni greatly promoted the nitridation process of Sialon ceramics and improved the weight gain rate and mechanical properties of specimens. With the increased content of catalysts, the apparent porosity of the products decreased first and then increased, contrary to flexural strength and compressive strength. The specimen with 2.5 wt% Fe had the highest flexural strength 145.8 MPa, and it exhibited the highest compressive strength of 594.6 MPa when Co content was 2.5 wt%, whereas they were 71.9 and 78.7 MPa, respectively, when without catalyst.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The flexible Li‐air battery (FLAB) with ultrahigh energy density is a hopeful candidate for flexible energy storage devices. However, most current FLAB operate in a pure oxygen atmosphere, which is ...limited by safety and corrosion issues from the metallic lithium anode and has thus greatly impeded the application of FLAB. Now, inspired by the protection effect of the umbrella, a stable hydrophobic composite polymer electrolyte (SHCPE) film with high flexibility, hydrophobicity, and stability was fabricated to protect the lithium anode. The SHCPE mitigated lithium corrosion and improved the capacity, rate performance, and cycle life (from 24 cycles to 95 cycles) of a battery in the ambient air. Based on the protection of SHCPE and the catalysis of MnOOH, the prepared pouch‐type FLAB displayed high flexibility, stable performances, long cycling life (180 cycles), and excellent safety; the battery can bear soaking in water, high temperature, and nail penetration.
Hold up an umbrella! A stable hydrophobic composite polymer electrolyte inspired by umbrellas was designed and fabricated on a lithium anode for a flexible Li‐air battery that can safely operate in the ambient air. Based on the in situ fabricated multifunctional electrolyte, the pouch‐type flexible Li‐air battery showed stable electrochemical performance and safety even under extreme conditions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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