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Pulmonary alveolar proteinosis (PAP) has been reported in rodents treated with nanoparticles (NPs). However, little is known about the type of NPs producing PAP and their toxicity mechanisms. Here, we assembled seven PAP-inducing NPs and TiO 2 NPs as a negative control. At 1 and 6 months after a single intratracheal instillation in rats, pulmonary inflammation and the gene expression of ATP-binding cassette (ABC) transporters and related genes were evaluated in separated alveolar macrophages (AMs). One month after intratracheal instillation, seven NPs (Eu 2 O 3 , In 2 O 3 , Pr 6 O 11 , Sm 2 O 3 , Tb 4 O 7 , and NiO) caused PAP, but only In 2 O 3 NPs caused persistent PAP at 6 months after treatment. The levels of phospholipids, indicators of PAP, showed good correlations with the gene expression profile of five transporters (ABCA1, ABCB4, ABCB8, ABCG1, and ABCG4), which effluxing phospholipids in AMs. Among them, ABCG1 and ABCG4 might be key transporters involved in PAP development because both showed a negative correlation with the magnitude of PAP, while others might be compensatory transporters for PAP recovery, as they showed a positive correlation. In conclusion, the identification of seven PAP-producing NPs implies that PAP may be an emerging occupational disease and that ABCG1 and ABCG4 may be therapeutic targets for PAP., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The combination effect of co-exposed different types of nanomaterials is little known although humans are generally exposed to a mixture of nanomaterials from urban ultrafine particles or industrial nanomaterials. Herein, we evaluated the combined effect of nanoparticles (NPs) using three types of NPs in different inflammogenic categories: carbon black (CB), nickel oxide (NiO), and copper oxide (CuO). A single type of NPs or NPs in combination was intratracheally instilled into the lungs of rats and the bronchoalveolar lavage fluid (BALF) was analyzed at 24 h after instillation to evaluate the acute inflammogenic potential. The percentage of neutrophils in BALF was selected as a toxicity endpoint and the potential for reactive oxygen species (ROS) generation, dose-response of the combined effect, sequential treatment of CB and NiO, and uptake of NiO to alveolar macrophages after combined treatment of CB and NiO were evaluated for the mechanism of the combined effect. Co-exposure of CuO and NiO showed an additive effect on the percentage of neutrophils and ROS generation potential, which implies that the physicochemical properties of each NP are not influenced by the other type. While CB exerted an antagonistic effect on the percentage of neutrophils in combined treatment with CuO or NiO. The antagonistic effect of CB was due to the scavenging activity of the ROS generated by the CuO and NiO rather than the competition in cellular uptake to target cells (i.e. alveolar macrophages), which highlight the importance of the combined effect of NPs in the risk assessment.

Workplace inhalation exposure to indium compounds has been reported to produce 'indium lung disease' characterized by pulmonary alveolar proteinosis (PAP), granulomas, and pulmonary fibrosis. However, there is little information about the pulmonary toxicity of nano-sized indium oxide (In 2 O 3 ), which is widely used in various applications such as liquid crystal displays. In this study, we evaluated the time-course and dose-dependent lung injuries by In 2 O 3 nanoparticles (NPs) after a single intratracheal instillation to rats. In 2 O 3 NPs were instilled to female Wistar rats at 7.5, 30, and 90 cm 2 /rat and lung injuries were evaluated at day 1, 3, 7, 14, 30, 90, and 180 after a single intratracheal instillation. Treatment of In 2 O 3 NPs induced worsening diverse pathological changes including PAP, persistent neutrophilic inflammation, type II cell hyperplasia, foamy macrophages, and granulomas in a time- and dose-dependent manner. PAP was induced from day 3 and worsened throughout the study. The concentrations of interleukin-1β, tumor necrosis factor-α, and monocyte chemoattractant protein-1 in bronchoalveolar lavage fluid (BALF) showed dose- and time-dependent increases and the levels of these inflammatory mediators are consistent with the data of inflammatory cells in BALF and progressive lung damages by In 2 O 3 NPs. This study suggests that a single inhalation exposure to In 2 O 3 NPs can produce worsening lung damages such as PAP, chronic active inflammation, infiltration of foamy macrophages, and granulomas. The early onset and persistent PAP even at the very low dose (7.5 cm 2 /rat) implies that the re-evaluation of occupational recommended exposure limit for In 2 O 3 NPs is urgently needed to protect workers.

This study investigated the removal efficiency and mechanisms of water contaminants (mainly N-nitrosamines) during municipal wastewater reclamation by a membrane bioreactor (MBR) and nanofiltration (NF) hybrid system. The removal of bulk water contaminants was governed by the microbial activities in the MBR and molecular weight cut-off (MWCO) of the NF membranes. The removal of N-nitrosamines by the MBR was primarily attributed to biodegradation by aerobic bacteria, which can be determined by the reactivity of the amine functional groups with the catabolic enzymes (removal efficiency=45-84%). Adsorption and formation of membrane fouling can enhance the removal of N-nitrosamines by the NF membranes. However, size-exclusion is found to play a major role in the removal of N-nitrosamines by the NF membranes since the removal efficiencies of N-nitrosamines varied significantly depending on molecular weight of the N-nitrosamines and MWCO of the NF membranes (removal efficiency: NE90>NE70)., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Highly luminescent Cd-free Zn doped CuInS(2) nanocrystals (ZCIS NCs) were synthesized, and their properties were evaluated using X-ray diffraction, Raman, UV, and photoluminescence. The crystal structure of the ZCIS NCs was similar to the zinc blende, and the lattice constant decreased with increasing Zn concentration. By incorporation of Zn, the emission wavelength was tuned from 536 to 637 nm with concomitant enhancement of the quantum yield up to 45%. A white light emitting diodes, integrating dual ZCIS NCs (λ(em) = 567, and 617 nm) and a 460 nm InGaN LED, exhibited a high color rendering index of 84.1 with a warm color temperature of 4256.2K. The CIE-1931 chromaticity coordinates were slightly shifted from (0.3626, 0.3378) at 20 mA to (0.3480, 0.3206) at 50 mA.

The nano-market has grown rapidly over the past decades and a wide variety of products are now being manufactured, including those for biomedical applications. Despite the widespread use of nanomaterials in various industries, safety and health effects on humans are still controversial, and testing methods for nanotoxicity have not yet been clearly established. Nanomaterials have been reported to interfere with conventional cytotoxicity tests due to their unique properties, such as light absorption or light scattering. In this regard, the colony-forming efficacy (CFE) assay has been suggested as a suitable test method for testing some nanomaterials without these color-interferences. In this study, we selected two types of GNPs (Graphene nanoplatelets) as test nanomaterials and evaluated CFE assay to assess the cytotoxicity of GNPs. Moreover, for further investigation, including expansion into other cell types, GNPs were evaluated by the conventional cytotoxicity tests including the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), Cell Counting Kit-8 (CCK-8), and Neutral red uptake (NRU) assay using MDCK, A549 and HepG2 cells. The results of CFE assay suggest that this test method for three cell lines can be applied for GNPs. In addition, the CFE assay was able to evaluate cytotoxicity regardless more accurately of color interference caused by residual nanomaterials. [ABSTRACT FROM AUTHOR]

This study was aimed at enhancing surface plasmon resonance through a combination of Ag nanoparticles (NPs) and an asymmetric crater structure capable of concentrating light. The crater structure was fabricated via wet-chemical etching of a GaAs(100) wafer, after which an Ag film was deposited inside, and subjected to rapid thermal annealing to form NPs. The results were analysed in terms of the magnitude of the Raman intensity, from which an optimal combination of annealing temperature and film thickness was determined. Ag nanowires (NWs) were also spray-coated onto the AgNPs to elucidate the effect of coupling the NPs with the NWs. The Raman intensity was 22 times higher inside the crater with AgNPs and NWs than on a flat area without NPs; however, further increases in the amount of AgNWs resulted in greater coverage of the AgNPs, which reduced the Raman intensity. We expect the proposed method for Raman signal enhancement to promote further development and applications of surface-enhanced Raman scattering (SERS) spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, the chemical structure at the interfaces of nanocomposite thin films, consisting of MgF2 nanoparticles and a plasma polymer fluorocarbon (PPFC) matrix, was analyzed to elucidate the relationship between fluorine dispersion and surface properties. Using self‐made MgF2–carbon nanotube–polytetrafluoroethylene ternary composite sputtering targets, MgF2 nanoparticles were successfully embedded in the PPFC matrix through sputtering. The spectrometric analysis showed that the fluorine atoms transfer at the nanoparticle interface created a carbon‐rich region in the PPFC polymer matrix, resulting in higher thin film hardness. The optimized MgF2 nanoparticle/PPFC matrix thin film showed that surface hardness reached 4.32 GPa, and it also exhibited high optical transparency and water repellency. MgF2–PPFC nanocomposite thin film could be applicable to protective optical coatings for display and automotive windows. [ABSTRACT FROM AUTHOR]

Due to the exponential increase in the development and utilization of rare earth oxide nanoparticles (REO NPs) in various fields, the possibility of exposure in humans by inhalation has increased. However, there are little information about hazards of REO NPs and its mechanisms of toxicity. In this study, we evaluated the acute pulmonary inflammation using 10 REO NPs (Dy2O3, Er2O3, Eu2O3, Gd2O3 La2O3, Nd2O3, Pr6 O11, Sm2O3, Tb4O7, and Y2O3) and four well-known toxic particles (CuO, NiO, ZnO, and DQ12). Minimum three doses per NP were instilled into the lungs of female Wistar rats at surface area dose metric and lung inflammation was evaluated at 24 h post-instillation by bronchoalveolar lavage fluid (BALF) analysis and histopathological observation. All types of REO NPs showed common pathological changes including mild to moderate infiltration of neutrophils and activated macrophages in the alveoli, peribronchial, and perivascular region. The inflammogenic potential evaluated by the number of granulocytes divided by the treated surface area dose showed all types of REO NPs has much higher inflammogenic potential than DQ12, ZnO, and NiO NPs. The correlation plot between the number of granulocytes and the potential for reactive oxygen species (ROS) generation showed a good correlation with exception of Pr6O11. The higher inflammogenic potential of REO NPs than that of well-known highly toxic particles imply that REO NPs need special attention for inhalation exposure and more studies are needed. In addition, the potential of ROS generation is one of the key factors producing lung inflammation by REO NPs. [ABSTRACT FROM AUTHOR]

The main mechanism of toxicity for fast-dissolving nanoparticles (NPs) is relatively simple as it originates from the intrinsic toxicity of their constituent elements rather than complicated surface reactivity. However, there is little information about the compared toxicity of fast-dissolving NP and its constituent ion, which is essential for understanding the mechanism of NP toxicity and the development of a structure-toxicity relationship (STR) model. Herein, we selected three types of fast-dissolving metaloxide NPs (CoO, CuO, and ZnO) and constituent metal chlorides (CoCl2, CuCl2, and ZnCl2) to compare dose-response curves between NP and its constituent metal. These materials were treated relevant cell lines for inhalation setting (i.e., differentiated THP-1 cells for macrophages and A549 cells for alveolar epithelial cells) and cytotoxicity as an endpoint was evaluated at 24 h post-incubation. The results showed that CoO and CuO NPs in both cell types showed similar patterns of dose-response curves and cytotoxic potential compared to that of their respective metal chloride. On the other hand, ZnO NPs in both cell types showed a completely different dose-response curve compared to that of ZnCl2: ZnO NPs showed modest slope and much less potential for cytotoxicity compared to that of ZnCl2. These results imply that fastdissolving metal-oxide NPs are not always have similar dose-response curves and toxic potentials compared to their constituent metal chlorides and this may be due to the differential mechanism of intracellular uptake of these substances and their interaction with intracellular detoxification molecules. Further investigations are needed for the use of toxic potential of metal ions as a predicting factors of fast-dissolving NPs toxicity. In addition, chelating agent specific for dissolved metal ions can be applied for the treatment of these fast-dissolving NPs. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO NPs) are used in various industries such as food additives, cosmetics, and biomedical applications. In this study, we evaluated lung damage over time by three types of ZnO NPs (L-serine, citrate, and pristine) following the regulation of functional groups after a single intratracheal instillation to rats. The three types of ZnO NPs showed an acute inflammatory reaction with increased LDH and inflammatory cell infiltration in the alveoli 24 h after administration. Especially in treatment with L-serine, citrate ZnO NPs showed higher acute granulocytic inflammation and total protein induction than the pristine ZnO NPs at 24 h. The acute inflammatory reaction of the lungs recovered on day 30 with bronchoalveolar fibrosis. The concentrations of IL-4, 6, TNF-α, and eotaxin in the bronchoalveolar lavage fluid (BALF) decreased over time, and the levels of these inflammation indicators are consistent with the following inflammatory cell data and acute lung inflammation by ZnO NP. This study suggests that single inhalation exposure to functionalized ZnO NPs may cause acute lung injury with granulocytic inflammation. Although it can recover 30 days after exposure, acute pulmonary inflammation in surface functionalization means that additional studies of exposure limits are needed to protect the workers that produce it. [ABSTRACT FROM AUTHOR]

Abstract: Origin of bistability in organic bistable memory devices (OBDs) was investigated by using two metal deposition processes of electron beam deposition and thermal deposition. Thermal deposition of Al was more effective than electron beam deposition to get high on/off ratio and stable operation of OBDs and metal nanoparticle formation during metal deposition was found to be critical to bistability of polymer OBDs. [Copyright &y& Elsevier]

Nowadays, various industries using nanomaterials are growing rapidly, and in particular, as the commercialization and use of nanomaterials increase in the cosmetic field, the possibility of exposure of nanomaterials to the skin of product producers and consumers is increasing. Due to the unique properties of nanomaterials with a very small size, they can act as hapten and induce immune responses and skin sensitization, so accurate identification of toxicity is required. Therefore, we selected silica nanomaterials used in various fields such as cosmetics and biomaterials and evaluated the skin sensitization potential step-by-step according to in-vitro and in-vivo alternative test methods. KeratinoSensTM cells of modified keratinocyte and THP-1 cells mimicking dendritic-cells were treated with silica nanoparticles, and their potential for skin sensitization and cytotoxicity were evaluated, respectively. We also confirmed the sensitizing ability of silica nanoparticles in the auricle-lymph nodes of BALB/C mice by in-vivo analysis. As a result, silica nanoparticles showed high protein binding and reactive oxygen species (ROS) mediated cytotoxicity, but no significant observation of skin sensitization indicators was observed. Although more studies are needed to elucidate the mechanism of skin sensitization by nanomaterials, the results of this study showed that silica nanoparticles did not induce skin sensitization. [ABSTRACT FROM AUTHOR]

Keywords: skin sensitization; alternative test; KeratinoSens TM; LLNA; dissolving nanoparticles; nanoparticles; copper; cobalt EN skin sensitization alternative test KeratinoSens TM LLNA dissolving nanoparticles nanoparticles copper cobalt N.PAG N.PAG 1 05/03/21 20210414 NES 210414 In the original article, there was an error. Skin sensitization, alternative test, KeratinoSens TM, LLNA, dissolving nanoparticles, nanoparticles, copper, cobalt. [Extracted from the article]

Graphene nanoplatelets (GNPs) are one of the major types of carbon based nanomaterials that have different industrial and biomedical applications. There is a risk of exposure to GNP material in individuals involved in their large-scale production and in individuals who use products containing GNPs. Determining the exact toxicity of GNP nanomaterials is a very important agenda. This research aimed to evaluate the skin sensitization potentials induced by GNPs using two types of alternative to animal testing. We analyzed the physicochemical characteristics of the test material by selecting a graphene nanomaterial with a nano-size on one side. Thereafter, we evaluated the skin sensitization effect using an in vitro and an in vivo alternative test method, respectively. As a result, we found that GNPs do not induce skin sensitization. In addition, it was observed that the administration of GNPs did not induce cytotoxicity and skin toxicity. This is the first report of skin sensitization as a result of GNPs obtained using alternative test methods. These results suggest that GNP materials do not cause skin sensitization, and these assays may be useful in evaluating the skin sensitization of some nanomaterials. [ABSTRACT FROM AUTHOR]

Human skins are exposed to nanomaterials in everyday life from various sources such as nanomaterial-containing cosmetics, air pollutions, and industrial nanomaterials. Nanomaterials comprising metal haptens raises concerns about the skin sensitization to nanomaterials. In this study, we evaluated the skin sensitization of nanomaterials comparing metal haptens in vivo and in vitro. We selected five metal oxide NPs, containing copper oxide, cobalt monoxide, cobalt oxide, nickel oxide, or titanium oxide, and two types of metal chlorides (CoCl2 and CuCl2), to compare the skin sensitization abilities between NPs and the constituent metals. The materials were applied to KeratinoSensTM cells for imitated skin-environment setting, and luciferase induction and cytotoxicity were evaluated at 48 h post-incubation. In addition, the response of metal oxide NPs was confirmed in lymph node of BALB/C mice via an in vivo method. The results showed that CuO and CoO NPs induce a similar pattern of positive luciferase induction and cytotoxicity compared to the respective metal chlorides; Co3O4, NiO, and TiO2 induced no such response. Collectively, the results implied fast-dissolving metal oxide (CuO and CoO) NPs release their metal ion, inducing skin sensitization. However, further investigations are required to elucidate the mechanism underlying NP-induced skin sensitization. Based on ion chelation data, metal ion release was confirmed as the major "factor" for skin sensitization. [ABSTRACT FROM AUTHOR]

Abstract: A highly dispersed 50 wt% Ni/MgO–Al2O3 catalyst was prepared by deposition–precipitation (DP) method for the diesel pre-reforming reaction. The pH of the precursor solution was controlled from pH 9.5 to 12.0 to examine the effects on NiO crystallite size and metal dispersion. The increase of pH of the precursor solution causes an increase of specific surface area and metal dispersion, and reduces NiO crystallite size. The pre-reforming reaction was carried out using n-tetradecane as surrogate compound of diesel. The coke formation of used catalysts was examined by TGA, TEM, SEM, and Raman analysis. The 50 wt% Ni/MgO–Al2O3 catalyst prepared at pH 11.5 showed a high catalytic activity and excellent coke resistance due to high metal dispersion (8.71%), small NiO crystallite size (3.5 nm), and strong interaction between Ni and support. Furthermore, this catalyst showed a good stability in the pre-reforming reaction at S/C ratio of 3.5 and 450 °C for 88 h. [Copyright &y& Elsevier]

Abstract: In this study, composite reverse osmosis (RO) membranes made from sulfonated poly(arylene ether sulfone) containing amino groups (aPES) and aminated template free zeolite nanoparticle (aTMA) were prepared with the aim of enhancing chlorination resistance and improving membrane performance. The performance of the RO membranes containing aPES and aTMA was evaluated; salt rejection and water flux were 98.8% and 37.8L/m2h, respectively. Salt rejection decreased by only 12.7% and water flux increased by 2.5L/m2h after the chlorination test. aPES/aTMA significantly modified the three-dimensional polyamide (PA) network structures and contributed to the high performance because of copolymer chain stiffness due to a high degree of cross-linking in the RO membranes. Therefore, aPES and aTMA, which helped improve water permeability, also protected the active layer structure from degradation and enhanced chlorine resistance of the RO membrane. [Copyright &y& Elsevier]

Abstract: Organic bistable memory devices (OBDs) with size-controlled polypyrrole (PPy) nanoparticles are developed by employing conducting PPy nanoparticle-embedded poly(vinyl alcohol) (PVA) as an active layer in OBDs. Monodisperse polypyrrole (PPy) nanoparticles with different diameters (20, 60, and 100nm) are fabricated via dispersion polymerization in order to evaluate size-dependent bistable memory characteristics. Stable multilevel switching and a high on/off ratio over 100 were demonstrated with 20nm of PPy in the OBDs. [Copyright &y& Elsevier]

Abstract: In this study, surface functionalized silica nanoparticles were prepared through a continuous two-step sol–gel process. After the TEOS-derived silica particles were synthesized, silane compounds were added during the second sol–gel process without any filtration or purification processes. The introductions of the organic chains to their surfaces were measured using 13C solid-state NMR. The effects of the hydrophilicity of the organo-chains on the silica particles were evaluated and analyzed by water contact angle and water wettability tests. The differences of surface charge in the dispersion state were analyzed by measuring the zeta-potential and the variations in the charge were measured as a function of pH. [Copyright &y& Elsevier]

Abstract: Phosphor conversion white LED was developed using a 460nm InGaN LED chip as an excitation source and yellow emitting Ce-activated YAG as the phosphor. YAG:Ce phosphor was obtained through solid state reaction (SSR) at 1500°C, and spray pyrolysis (SP) at 900°C. The SSR and SP prepared YAG:Ce had strong excitation peaks at 460nm, and broad band emissions from 540nm to 580nm due to d–f transition of the Ce ion. The fabricated white LED using SSR-YAG:Ce and SP-YAG:Ce showed a luminous efficiency of 65.8lmW−1 with CRI of 65.1, and 92.1lmW−1 with CRI of 67.7 at 20mA, respectively. For high CRI values, CdSe/ZnSe nanoparticles emitting at 622nm were prepared via the wet chemical method. The high CRI values of the white LED were achieved by efficient energy transfer from YAG:Ce to CdSe/ZnSe nanoparticles in hybrid phosphor system. The luminous efficiency of the hybrid phosphor white LED was 77.1lmW−1 and this device showed an excellent CRI of 92.3 at 20mA. The CIE of the white LED was varied from (0.34, 0.31) to (0.35, 0.31) when the applied currents increased from 20 to 60mA. [ABSTRACT FROM AUTHOR]