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Reflection-type photoplethysmography (PPG) pulse sensors used in wearable smart watches, true wireless stereo, etc., have been recently considered a key component for monitoring biological signals such as heart rate, SPO3, and blood pressure. Typically, the optical front end (OFE) of these PPG sensors is heterogeneously configured and packaged with light sources and receiver chips. In this paper, a novel quarter-annulus photodetector (NQAPD) with identical inner and outer radii of curvature has been developed using a plasma dicing process to realize a ring-type OFE receiver, which maximizes manufacturing efficiency and increases the detector collection area by 36.7% compared to the rectangular PD. The fabricated NQAPD exhibits a high quantum efficiency of over 90% in the wavelength of 500 nm to 740 nm and the highest quantum efficiency of 95% with a responsivity of 0.41 A/W at the wavelength of 530 nm. Also, the NQAPD is shown to increase the SNR of the PPG signal by 5 to 7.6 dB compared to the eight rectangular PDs. Thus, reflective PPG sensors constructed with NQAPD can be applied to various wearable devices requiring low power consumption, high performance, and cost-effectiveness.

As the development of autonomous driving technology is now in full swing, the demand for miniaturized optical modules mounted on various sensors has increased. Particularly, the optical lens used for such autonomous driving must demonstrate stable performance and durability despite rapid changes in the external environment. In this regard, cubic zirconia (CZ) can be used as an optical lens due to its high refractive index, which is above 2.1 in visible and near-infrared wavelengths, along with its chemical and mechanical durability. Thus, in this paper, we investigated the temperature-dependent physical properties of CZ fabricated by the skull melting method. The temperature coefficient of the refractive index (dn/dT) of the fabricated CZ plate in the temperature range of 25–100 °C decreased from 9.76 × 10−5/K to 7.00 × 10−5/K as the wavelength increased from 447.0 nm to 785.0 nm. The estimated Abbe number decreased from 33.98 at 25 °C to 33.12 at 100 °C, while the measured coefficient of thermal expansion (CTE) was 9.91 × 10−6/K, which revealed that the dn/dT value of the CZ plate was more affected by the dispersion than by the CTE. In addition, the CZ samples with a high refractive index, coated with a dielectric multilayer showed a high average transmittance of 98.2% at the investigated wavelengths, making it suitable for miniaturization or wide-angle optical lens modules. To secure the durability required for automobile lenses, the variation in the surface profile of the CZ before and after the external impact was also analyzed, revealing much better performance than TAF glass. Therefore, the observed results demonstrate that the CZ material is suitable for use as an optical lens for autonomous vehicles.

To realize high-resolution thermal images with high quality, it is essential to improve the noise characteristics of the widely adopted uncooled microbolometers. In this work, we applied the post-metal annealing (PMA) process under the condition of deuterium forming gas, at 10 atm and 300 °C for 30 min, to reduce the noise level of amorphous-Si microbolometers. Here, the DC and temperature coefficient of resistance (TCR) measurements of the devices as well as 1/f noise analysis were performed before and after the PMA treatment, while changing the width of the resistance layer of the microbolometers with 35 μm or 12 μm pixel. As a result, the microbolometers treated by the PMA process show the decrease in resistance by about 60% and the increase in TCR value up to 48.2% at 10 Hz, as compared to the reference device. Moreover, it is observed that the noise characteristics are improved in inverse proportion to the width of the resistance layer. This improvement is attributed to the cured poly-silicon grain boundary through the hydrogen passivation by heat and deuterium atoms applied during the PMA, which leads to the uniform current path inside the pixel.

Abstract Micro-fabricated single-layer graphenes (SLGs) on a silicon dioxide (SiO2)/Si substrate, a silicon nitride (SiN) membrane, and a suspended architecture are presented for their use as temperature sensors. These graphene temperature sensors act as resistance temperature detectors, showing a quadratic dependence of resistance on the temperature in a range between 283 K and 303 K. The observed resistance change of the graphene temperature sensors are explained by the temperature dependent electron mobility relationship (~T−4) and electron-phonon scattering. By analyzing the transient response of the SLG temperature sensors on different substrates, it is found that the graphene sensor on the SiN membrane shows the highest sensitivity due to low thermal mass, while the sensor on SiO2/Si reveals the lowest one. Also, the graphene on the SiN membrane reveals not only the fastest response, but also better mechanical stability compared to the suspended graphene sensor. Therefore, the presented results show that the temperature sensors based on SLG with an extremely low thermal mass can be used in various applications requiring high sensitivity and fast operation.

Improving the stability of perovskite solar cells remains crucial. Here, Ahn et al. show that trapped charges at grain boundaries induce the dissociation of the perovskite compound in the presence of moisture, and explain why degradation is irreversible under illumination and reversible in the dark.

High crystalline ZnO nanorods (NRs) on Zn pre-deposited graphene/Cu sheet without graphene transfer process have been fabricated by self-catalyzed vapor-phase transport synthesis. Here, the pre-deposited Zn metal on graphene not only serves as a seed to grow the ZnO NRs, but also passivates the graphene underneath. The temperature-dependent photoluminescence spectra of the fabricated ZnO NRs reveal a dominant peak of 3.88 eV at 10 K associated with the neutral-donor bound exciton, while the redshifted peak by bandgap shrinkage with temperature and electron-lattice interactions leads a strong emission at 382 nm at room temperature. The optical absorption of the ZnO NRs/graphene hetero-nanostructure at this ultraviolet (UV) emission is then theoretically analyzed to quantify the absorption amount depending on the ZnO NR distribution. By simply covering the ZnO NR/graphene/Cu structure with the graphene/glass as a top electrode, it is observed that the current-voltage characteristic of the ZnO NR/graphene hetero-nanojunction device exhibits a photocurrent of 1.03 mA at 3 V under a light illumination of 100 μW/cm2. In particular, the suggested graphene/ZnO NRs/graphene hybrid-nanostructure-based devices reveal comparable photocurrents at a bidirectional bias, which can be a promising platform to integrate 1D and 2D nanomaterials without complex patterning process for UV device applications.

Novel antireflective (AR) structures have attracted tremendous attention and been used in various applications such as solar cells, displays, wearable devices, and others. They have also stimulated the development of several other methods, including moth-eye-inspired technologies. However, the analyses of the shapes and sizes of nanostructures remain a critical issue and need to be considered in the design of effective AR surfaces. Herein, moth-eye and inverse-moth-eye patterned polyurethane-acrylate (PUA) structures (MPS and IMPS) with three different sizes are analyzed and compared to optimize the designed nanostructures to achieve the best optical properties pertaining to maximum transmittance and minimum reflectance. We fabricated moth-eye-inspired conical structures with three different sizes using a simple and robust fabrication method. Furthermore, the fabricated surfaces of the MPS and IMPS structures were analyzed based on the experimental and theoretical variation influences of their optical properties according to their sizes and shapes. As a result of these analyses, we herein propose a standard methodology based on the optimal structure of IMPS structure with a 300 nm diameter.

Background Despite the 2015 American College of Medical Genetics and Genomics (ACMG) and Association of Molecular Pathology (AMP) guideline, many variants of FBN1 gene remain inconclusive. In line with publication of the FBN1-specific variant interpretation guideline by ClinGen in 2022, we reassessed variants of uncertain significance (VUS) in FBN1 gene found in our institution. Methods VUS found in the course of FBN1 sequencing between December 2015 and April 2022 were reassessed based on FBN1-specific variant interpretation guideline, review of updated literatures and additional genetic tests including family study and/or RNA study if available. Results Out of 695 patients who underwent FBN1 sequencing, 61 VUS were found in 69 patients. Among them, 38 VUS in 43 patients (62.3%) were reclassified as pathogenic and likely pathogenic variant ((L)PV), including 20 novel (L)PV. Major causes of reclassification were: (1) gene-specific modification of ACMG/AMP criteria, (2) updated literatures and (3) additional genetic tests. The most important evidence for reclassification was clarification of critical amino acid residues. Conclusions After reassessing FBN1 variants according to FBN1-specific guideline and up-to-date database, a significant number of VUS was reclassified. Clinical laboratories are encouraged to perform variant reassessment at regular intervals or when there is a major change in the principle of variant interpretation. [ABSTRACT FROM AUTHOR]

Background: Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. Methods: We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. Results: Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. Conclusions: The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk. [ABSTRACT FROM AUTHOR]

Background Hazard identification for risk assessment of nanoparticles (NPs) is mainly composed of in vitro cell-based assays and in vivo animal experimentation. The rapidly increasing number and functionalizations of NPs makes in vivo toxicity tests undesirable on both ethical and financial grounds, creating an urgent need for development of in vitro cell-based assays that accurately predict in vivo toxicity and facilitate safe nanotechnology. Methods In this study, we used 9 different NPs (CeO2, TiO2, carbon black, SiO2, NiO, Co3O4, Cr2O3, CuO, and ZnO). As an in vivo toxicity endpoint, the acute lung inflammogenicity in a rat instillation model was compared with the in vitro toxicity endpoints comprising cytotoxicity, pro-inflammatory cytokine expression, or haemolytic potential. For in vitro assays, 8 different cell-based assays were used including epithelial cells, monocytic/macrophage cells, human erythrocytes, and combined culture. Results ZnO and CuO NPs acting via soluble toxic ions showed positive results in most of assays and were consistent with the lung inflammation data. When compared in in vitro assays at the same surface area dose (30 cm2/mL), NPs that were low solubility and therefore acting via surface reactivity had no convincing activity, except for CeO2 NP. Cytotoxicity in differentiated peripheral blood mononuclear cells was the most accurate showing 89% accuracy and 11% false negativity in predicting acute lung inflammogenicity. However, the haemolysis assay showed 100% consistency with the lung inflammation if any dose, having statistical significance was considered positivity. Other cell-based in vitro assays showed a poorer correlation with in vivo inflammogenicity. Conclusions Based on the toxicity mechanisms of NPs, two different approaches can be applied for prediction of in vivo lung inflammogenicity. Most in vitro assays were good at detecting NPs that act via soluble ions (i.e., ZnO and CuO NP). However, in vitro assays were limited in detecting NPs acting via surface reactivity as their mechanism of toxicity, except for the haemolysis assay. [ABSTRACT FROM AUTHOR]

Background: The in vivo kinetics of nanoparticles is an essential to understand the hazard of nanoparticles. Here, the absorption, distribution, and excretion patterns of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles following oral administration were evaluated. Methods: Nanoparticles were orally administered to rats for 13 weeks (7 days/week). Samples of blood, tissues (liver, kidneys, spleen, and brain), urine, and feces were obtained at necropsy. The level of Ti or Zn in each sample was measured using inductively coupled plasma-mass spectrometry. Results: TiO2 nanoparticles had extremely low absorption, while ZnO nanoparticles had higher absorption and a clear dose-response curve. Tissue distribution data showed that TiO2 nanoparticles were not significantly increased in sampled organs, even in the group receiving the highest dose (1041.5 mg/kg body weight). In contrast, Zn concentrations in the liver and kidney were significantly increased compared with the vehicle control. ZnO nanoparticles in the spleen and brain were minimally increased. Ti concentrations were not significantly increased in the urine, while Zn levels were significantly increased in the urine, again with a clear dose-response curve. Very high concentrations of Ti were detected in the feces, while much less Zn was detected in the feces. Conclusions: Compared with TiO2 nanoparticles, ZnO nanoparticles demonstrated higher absorption and more extensive organ distribution when administered orally. The higher absorption of ZnO than TiO2 nanoparticles might be due to the higher dissolution rate in acidic gastric fluid, although more thorough studies are needed. [ABSTRACT FROM AUTHOR]

Background: Carbon nanotubes (CNTs) are engineered graphene cylinders with numerous applications in engineering, electronics and medicine. However, CNTs cause inflammation and fibrosis in the rodent lung, suggesting a potential human health risk. We hypothesized that multi-walled CNTs (MWCNTs) induce two key inflammatory enzymes in macrophages, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), through activation of extracellular signal-regulated kinases (ERK1,2). Methods: RAW264.7 macrophages were exposed to MWCNTs or carbon black nanoparticles (CBNPs) over a range of doses and time course. Uptake and subcellular localization of MWCNTs was visualized by transmission electron microscopy (TEM). Protein levels of COX-2, iNOS, and ERK1,2 (total ERK and phosphorylated ERK) were measured by Western blot analysis. Prostaglandin-E2 (PGE2) and nitric oxide (NO) levels in cell supernatants were measured by ELISA and Greiss assay, respectively. Results: MWCNTs, but not CBNPs, induced COX-2 and iNOS in a time- and dose-dependent manner. COX-2 and iNOS induction by MWCNTs correlated with increased PGE2 and NO production, respectively. MWCNTs caused ERK1,2 activation and inhibition of ERK1,2 (U0126) blocked MWCNT induction of COX-2 and PGE2 production, but did not reduce the induction of iNOS. Inhibition of iNOS (L-NAME) did not affect ERK1,2 activation, nor did L-NAME significantly decrease COX-2 induction by MWCNT. Nickel nanoparticles (NiNPs), which are present in MWCNTs as a residual catalyst, also induced COX-2 via ERK-1,2. However, a comparison of COX-2 induction by MWCNTs containing 4.5 and 1.8% Ni did not show a significant difference in ability to induce COX-2, indicating that characteristics of MWCNTs in addition to Ni content contribute to COX-2 induction. Conclusion: This study identifies COX-2 and subsequent PGE2 production, along with iNOS induction and NO production, as inflammatory mediators involved in the macrophage response to MWCNTs. Furthermore, our work demonstrates that COX-2 induction by MWCNTs in RAW264.7 macrophages is ERK1,2-dependent, while iNOS induction by MWCNTs is ERK1,2-independent. Our data also suggest contributory physicochemical factors other than residual Ni catalyst play a role in COX-2 induction to MWCNT. [ABSTRACT FROM AUTHOR]

Pirimiphos-methyl (O-2-diethylamino-6-methylpyrimidin-4-yl O,O-dimethyl phosphorothioate: POM) is widely used organophosphorous(OP) insecticide as a grain protectant to control insects during storage. This study was carried out to assess the immunologic effects of POM in Balb/c mice after 28-day oral exposure. Three dose levels of POM (10, 60, or 120 mg/kg/day) were administered orally to mice for 4 weeks. At autopsy after 28-day exposure, there were significant decreases in relative spleen weight and splenic cellularity found at 120 mg POM, but body weight, relative thymic weight, thymic cellularity, and splenic and thymic subsets were not affected. T cell proliferation response induced by Con A was significantly decreased at all dosages though no statistical differences were observed in splenic B cell proliferation. Significant increases in the production of cytokines (IL-2, IL-4, IL-6, IFN- γ, and IL-10) were evident on the whole, but the increase in production of inflammatory cytokines overwhelmed that of the TH1 cell suppressive cytokine (IL-10). The relative levels of three types of autoantibodies, anti-dsDNA, anti-histone, and antinuclear antibody (ANA) were dose-dependently decreased in serum. Oral exposure to POM induced a significant decrease in Immunoglobulin M production capability in Balb/c mice. This decrease in antibody production capability may result from disturbances in cytokine balance produced by splenic immune cells. These results show that POM may induce allergic responses by relatively enhancing TH2 development and additionally contribute to chronic inflammation by attracting macrophage by IFN-γ. [ABSTRACT FROM AUTHOR]

A 14.3-in flexible color electronic-paper display with the highest resolution has been developed. This display uses an electrophoretic material between a-Si:H thin-film transistors (TFTs) on a metal foil and a color filter array (CFA) coated onto a plastic substrate, allowing it to recover its original shape after being bent and to produce color images. To make this new display possible, low-temperature processes (< 150 °C) for TFT and CFA on flexible substrates have been developed, resulting in the minimization of panel deformation and the prevention of circuit structure change. Here, we also develop a U-type dual TFT structure and a quad-type CFA pattern suitable for this reflective-type display. [ABSTRACT FROM AUTHOR]

Evaluates the Schottky barrier heights and conduction-band offsets of In[sub 1-x]Ga[sub x]As[sub 1-y]P[sub y] epilayers. Growth of epilayers on gallium arsenide substrates; Dependence of Schottky barrier heights on the composition of the substrate material; Correlation between metal-semiconductor and semiconductor-semiconductor heterointerfaces.

We demonstrate a highly sensitive and flexible bending strain sensor using tin-doped indium oxide (ITO) nanoparticles (NPs) assembled in line patterns on flexible substrates. By utilizing transparent ITO NPs without any surface modifications, we could produce strain sensors with adjustable gauge factors and optical transparency. We were able to control the dimensional and electrical properties of the sensors, such as channel height and resistance, by controlling the NP assembly speed. Furthermore, we were able to generate controlled gauge factor with values ranging from 18 to 157, which are higher than previous cases using metallic Cr NPs and Au NPs. The alignment of the ITO NPs in parallel lines resulted in low crosstalk between the transverse and longitudinal bending directions. Finally, our sensor showed high optical transmittance, up to ∼93% at 500 nm wavelength, which is desirable for flexible electronic applications. [ABSTRACT FROM AUTHOR]

We report three-dimensionally assembled nanoparticle structures inducing multiple plasmon resonances for broadband light harvesting in nanocrystalline silicon (nc-Si:H) thin-film solar cells. A three-dimensional multiscale (3DM) assembly of nanoparticles generated using a multi-pin spark discharge method has been accomplished over a large area under atmospheric conditions via ion-assisted aerosol lithography. The multiscale features of the sophisticated 3DM structures exhibit surface plasmon resonances at multiple frequencies, which increase light scattering and absorption efficiency over a wide spectral range from 350–1100 nm. The multiple plasmon resonances, together with the antireflection functionality arising from the conformally deposited top surface of the 3D solar cell, lead to a 22% and an 11% improvement in power conversion efficiency of the nc-Si:H thin-film solar cells compared to flat cells and cells employing nanoparticle clusters, respectively. Finite-difference time-domain simulations were also carried out to confirm that the improved device performance mainly originates from the multiple plasmon resonances generated from three-dimensionally assembled nanoparticle structures. [ABSTRACT FROM AUTHOR]

Glass is a food contact material that has been used for a long time in food packaging because it is chemically durable and stable. However, when used for a long time in an aqueous solution or under certain conditions in which alteration may occur, solid flakes may be formed. The phenomenon could be observed when the process of boiling water in a glass kettle is repeated. Transparent and shiny needle-shaped glass fragments appear floating in the water, which may cause complaints from consumers.The purpose of this study is to investigate the conditions leading to the formation of flakes and to identify the components of the suspended flakes in glass container.In this study we investigated the formation of flakes at different temperatures (70–100 °C), initial pH values (3–11) and varying the solution composition (with Na+, K+, Ca2+, Mg2+ concentrations from 0.2 to 40 mg/L). Two types of glass materials, soda-lime-silica glass and borosilicate glass (heat-resistance glass) were examined.Results show that flakes were observed under the following conditions: 24 h at more than 90 °C, pH 8, and 20 mg/L Ca2+ for soda-lime-silica glass and more than 100 °C, pH 11 for borosilicate glass. The component of flakes was identified as a mixture of hydrates of magnesium, calcium, and aluminum silicate analyzed by X-ray fluorescence spectroscopy, inductively coupled plasma-optical emission spectroscopy, and X-ray diffraction.

Abstract Some drugs cause phototoxicity in humans when exposed to light, thus there is a need for an in vivo phototoxicity test to evaluate them. However, an in vivo phototoxicity test method to evaluate this has not been established. This study aimed to establish an in vivo phototoxicity test method for transdermally administered drugs. For this, we evaluated the phototoxicity using Sprague-Dawley (SD) rats for transdermal administered drugs and we studied the appropriate UVA dose using 8-methoxypsalen, which is a well-known phototoxic drug. We found that a UVA dose of 15 J/cm2 was dose and time dependent response compared to other UVA doses. We performed the Minimum Erythema Dose (MED) test because UVB can cause skin irritation by itself and selected 0.01 J/cm2 as an appropriate dose of UVB. Using the selected UVA and UVB doses, we performed a phototoxicity study of 6 pharmaceutical drugs, which included phototoxic and non-phototoxic drugs. As a result of the phototoxicity test, 100% accuracy was obtained when compared with previous studies. In addition, we performed histopathology to confirm the new findings. We found that histopathology can be used as an additional indicator of phototoxicity test for transdermally administered drugs.

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.

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.

Titanium dioxide nanoparticles (TiO2-NPs) are used to improve the aesthetic of toothpaste. While TiO2-NPs have been used safely in toothpaste products for a long time, there haven't been studies to determine whether absorption of TiO2-NPs by the mucous membranes in the mouth induces pathogenic conditions. Here, we assessed whether TiO2-NPs induce cyclooxygenase-2 (COX-2) and investigated the molecular mechanisms underlying the pro-inflammatory effect of TiO2-NPs on human periodontal ligament (PDL) cells. Treatment of PDL cells with TiO2-NPs led to induction of both COX-2 mRNA and protein expression. TiO2-NPs stimulated the nuclear translocation of nuclear factor-kappaB (NF-κB) as well as its DNA binding by inducing phosphorylation and subsequent degradation of the inhibitory protein IκBa in PDL cells. TiO2-NPs treatment resulted in rapid activation of extracellular signal- regulated kinase (ERK)1/2 and Akt, which could be upstream of NF-κB. Treatment of PDL cells with both the MEK1/2 inhibitor U0126 and the PI3K inhibitor LY294002 strongly attenuated TiO2-NPs-induced activation of NF-κB, and also the expression of COX-2. PDL cells treated with TiO2-NPs exhibited increased accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with ROS scavenger N-acetyl cysteine (NAC) abrogated the stimulatory effect of TiO2-NPs on p65, p50, and COX-2 expression. In conclusion, ROS, concomitantly overproduced by TiO2-NPs, induce COX-2 expression through activation of NF-κB signaling, which may contribute to the inflammatory effect of PDL cells. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are one of the major types of nanomaterials that have various industrial and biomedical applications. However, there is a risk of accidental exposure to CNTs in individuals involved in their large-scale production and in individuals who use products containing CNTs. This study aimed to evaluate the skin sensitization induced by CNTs using two alternative tests. We selected single-wall carbon nanotubes and multi-walled carbon nanotubes for this study. First, the physiochemical properties of the CNTs were measured, including the morphology, size, and zeta potential, under various conditions. Thereafter, we assessed the sensitization potential of the CNTs using the ARE-Nrf2 Luciferase KeratinoSens™ assay, an in vitro alternative test method. In addition, the CNTs were evaluated for their skin sensitization potential using the LLNA: BrdU-FCM in vivo alternative test method. In this study, we report for the first time the sensitization results of CNTs using the KeratinoSens™ and LLNA: BrdU-FCM test methods in this study. This study found that both CNTs do not induce skin sensitization. These results suggest that the KeratinoSens™ and LLNA: BrdU-FCM assay may be useful as alternative assays for evaluating the potential of some nanomaterials that can induce skin sensitization.

The compound 6:2 chlorinated polyfluorinated ether sulfonate (F-53B), a replacement for perfluorooctanesulfonate (PFOS) in the electroplating industry, has been widely detected in numerous environmental matrices, human sera, and organisms. Due to regulations that limit PFOS use, F-53B use is expected to increase. Therefore, in this study, we performed a subchronic oral toxicity study of F-53B in Sprague Dawley (SD) rats. F-53B was administered orally once daily to male and female rats for 28 days at doses of 5, 20, and 100 mg/kg/day. There were no toxicologically significant changes in F-53B-treated rats, except in the thyroid gland. However, F-53B slightly reduced the serum concentrations of thyroid hormones, including triiodothyronine and thyroxine, compared with their concentrations in the vehicle group. F-53B also induced follicular hyperplasia and was associated with increased thyroid hormone biosynthesis-associated protein expression. These results demonstrate that F-53B is a strong regulator of thyroid hormones in SD rats as it disrupts thyroid function. Thus, caution should be exercised in the industrial application of F-53B as an alternative for PFOS.