Suchergebnisse

Abstract
To facilitate hazard characterisation for inhaled engineered nanomaterials we have established an aerosol exposure air-liquid-interface (AE-ALI) system, incorporating a Cultex RFSTM cell exposure system. While offering potential benefits in terms of more realistic aerosol exposure mode over traditional submerged in vitro models and being in-line with the principles of the 3Rs, (replace, reduce and refine animal use), detailed system characterisation is required to produce reliable and reproducible results. As such, this work looked to fully characterise our AE-ALI system with a view to optimising cell viability of system controls and deposition quantity, uniformity, and reproducibility for engineered nanomaterials. Using a nano-CeO2 aerosol, the effects of exposure conditions and system parameters (e.g. temperature, electrostatic precipitator voltage and airflow) on deposition efficiency, pattern and reproducibility were investigated using ICP-MS. While results showed that appropriate choice of operating parameters can produce broadly uniform deposition, reproducibility was low, and dose monitoring during exposures is recommended. After initial optimisation of the system for deposition, the effect of exposure duration, well size and flowrate on cellular responses (e.g. cytotoxicity (LDH) and selected gene expression (IL-8, CXCL1, HMOX1, SPP1) of system controls (H2O aerosol) was investigated using human lung alveolar (A549) and primary small airway epithelial cells. Results indicate that even after optimisation for cell health, the system itself is "toxic" to cells in comparison to incubator controls, with increasing effects observed with exposure duration meaning exposure durations must be minimised. Results from this study highlight the need for detailed characterisation of AE-ALI systems prior to use.

BACKGROUND: The wooden bowl is an important symbol of the Tibetan cultures, yet, in China, little has been documented regarding the raw materials used to make these items as well as their cultural significance in Tibet. This study explores the ethnobotanical uses of plants used to make wooden bowls to understand their sustainability, cultural significance, and current status of related traditional knowledge in Gyirong Town, which is one of the most famous places for wooden bowl making. MATERIALS AND METHODS: Between 2019 and 2021, key informant interviews, semi-structured interviews, and participatory observations were used to conduct ethnobotanical field surveys in Gyirong Valley. The field work was performed with the assistance of local guides. In this study, we utilized a use-report (UR) to reflect the number of mentions of a species by locals. RESULTS: Our results show that 16 different plants are used during the wooden bowl making process, of which nine are used as raw materials, three for dyeing, and four for varnishing. Although communities rely heavily on these plants, good management and collection methods were observed. We also documented the use of Fallopia denticulata as a red dye and four species of Impatiens as wood varnishes for the first time. CONCLUSION: The wooden bowl craftsmen and their housewives have a wealth of traditional knowledge of using plants to make wooden bowls in Gyirong Town. And the wooden bowls are now also offering benefits to the locals as well. The government and local people are committed to the protection and development of traditional knowledge related to wooden bowls, and this knowledge maintains a healthy degree of vitality. This research can provide insights into the vitality of traditional handicrafts that are facing challenges and promote their protection.

Traditional wireless security focuses on preventing unmanned aerial vehicle (UAV) communications from suspicious eavesdropping and/or jamming attacks. However, there is a growing need for governments to keep malicious UAV communications under legitimate surveillance. This paper first investigates a new surveillance paradigm for monitoring suspicious UAV communications via jamming suspicious UAVs. Due to the power consumption limitation, the choice of eavesdropping and jamming will reflect the performance of the UAVs communication. Therefore, the paper analyses the UAV's eavesdropping and jamming models in different cases, and then proposes the model to optimize the data package in the constraints of lower power consumption, which can be solved by the proposed selection policy. The simulation results validate our proposed selection policy in terms of power consumption and eavesdropped packets. In different fading models, power consumption increases with time, regardless of distances, and our proposed policy performs better in Weibull fading channels in terms of eavesdropped packets.

Traditional wireless security focuses on preventing unmanned aerial vehicle (UAV) communications from suspicious eavesdropping and/or jamming attacks. However, there is a growing need for governments to keep malicious UAV communications under legitimate surveillance. This paper first investigates a new surveillance paradigm for monitoring suspicious UAV communications via jamming suspicious UAVs. Due to the power consumption limitation, the choice of eavesdropping and jamming will reflect the performance of the UAVs communication. Therefore, the paper analyses the UAV's eavesdropping and jamming models in different cases, and then proposes the model to optimize the data package in the constraints of lower power consumption, which can be solved by the proposed selection policy. The simulation results validate our proposed selection policy in terms of power consumption and eavesdropped packets. In different fading models, power consumption increases with time, regardless of distances, and our proposed policy performs better in Weibull fading channels in terms of eavesdropped packets. ; info:eu-repo/semantics/publishedVersion

Abstract
Cerium oxide nanoparticles (CeO2NPs) from some diesel fuel additives and other applications have been detected in ambient air. Concerns have been raised over their potential human health impact in situations of inadvertent exposure. Oxidative mechanisms have been suggested as a common feature for pulmonary injury in response to airborne particulate matter, including engineered nanomaterials. To understand in depth how CeO2NPs may influence oxidative stress induced pulmonary inflammation and fibrotic events, we used both in vivo and in vitro bleomycin-induced lung injury models. Male Sprague-Dawley rats were intratracheally instilled with bleomycin or saline (control) followed by nose-only inhalation exposure to nano-sized CeO2NP aerosols (mass concentration 1.8 mg/m3) or water (controls) for 3 hours per day for 4 days per week for one or two weeks. At 3 days post exposure, animals were sacrificed and bronchoalveolar lavage (BAL) fluid, lung histopathology and global mRNA expression analysed. Bleomycin exposure resulted in an increase in total BAL cells, fibrotic staining and significant induction of inflammatory and oxidative stress on mRNA sequencing analysis. Modifications of these responses by one-week exposure to CeO2NPs included attenuation of fibrotic staining and gene expression markers of lung function, inflammation and epithelial-mesenchymal transition (EMT). CeO2NP alone resulted in increased inflammatory responses but did not appear to cause fibrotic changes. Interpretation of these responses at a cellular level was further explored using 3D human small airway epithelium cultures (SmallAirTM) in an aerosol exposure air-liquid-interface system. This also indicated that some bleomycin-induced cellular responses could be attenuated by exposure to CeO2NP aerosols.

Abstract
Ambient nitrogen dioxide (NO2) and particulate matter (PM) concentrations are often found to be proportional, such that inhalation of one pollutant is expected to be accompanied by the inhalation of the other. Epidemiological evidence consistently demonstrates the health burdens associated with the inhalation of NO2 and PM, though has difficulty deciphering the inhalation hazard of either pollutant individually. Airway models can be exposed to NO2 and PM separately or as a co-exposure in vitro, allowing mechanisms of toxicity to be elucidated. Herein, NCI-H441 cells were exposed to either 780 ng/cm2 Printex 90 carbon black (CB) (a surrogate model of PM) using a VitroCell Cloud12, 5 ppm NO2 (within a modified Coy hypoxic cabinet) or a combination of NO2+CB over 24 hours. Cytotoxicity was not altered by NO2 or CB (trypan blue exclusion assay), however CB, and to a lesser extent CB+NO2 exposure resulted in a non-significant increase in membrane permeability (p>0.05). qPCR revealed no alterations in expression of superoxide dismutase 1 (SOD1) for any exposure condition. Both CB and NO2 exposures resulted in significantly increased IL6 and IL8 release (ELISA) (p<0.05), although co-exposure of the two pollutants did not augment the detected IL6 or IL8 levels. These data indicate NO2 and CB produce an inflammatory response in this model, though little evidence suggests that NO2 and CB act in an additive or synergistic manner via this pathway. Additional work remains ongoing to establish the mechanisms of toxicity utilising an anatomically relevant triple cell co-culture of the alveolar epithelial barrier.