The morbidity and mortality related to respiratory tract diseases is enormous, with hundreds of millions of individuals afflicted and four million people dying each year. Understanding the immunological processes in the mucosa that govern outcome following pathogenic encounter could lead to novel therapies. There is a need to study responses at mucosal surfaces in humans for two reasons: (i) Immunological findings in mice, or other animals, often fail to translate to humans. (ii) Compartmentalization of the immune system dictates a need to study sites where pathogens reside. In this manuscript, we describe two novel non-invasive nasal mucosal microsampling techniques and their use for measuring immunological parameters: 1) using nasal curettes to collect cells from the inferior turbinate and; 2) absorptive matrices to collect nasal lining fluid. Both techniques were well tolerated and yielded reproducible and robust data. We demonstrated differences in immune populations and activation state in nasal mucosa compared to blood as well as compared to nasopharyngeal lumen in healthy adults. We also found superior cytokine detection with absorptive matrices compared to nasal wash. These techniques are promising new tools that will facilitate studies of the immunological signatures underlying susceptibility and resistance to respiratory infections.
Fused filament fabrication (FFF) or fused deposition modeling is an additive manufacturing (AM) process commonly used for geometric modeling and rapid prototyping of parts called three-dimensional (3-D) printing. Commonly used thermoplastic materials in FFF 3-D printing AM are acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and polybutylene terephthalate (PBT). However, these materials exhibit relatively low strength and toughness. Therefore, it is desirable to improve various properties of thermoplastics in 3-D printing AM by employing nanotechnology. The combination of 3-D printing and nanotechnology opens new venues for the manufacture of 3-D engineered materials with optimized properties and multifunctionality (e.g. mechanical, electrical, and thermal properties). Hence, in this work, the multifunctional property improvement effects of graphene oxide (GO) on thermoplastic materials suitable for 3-D printing AM are investigated. Low loading of GO with carboxyl and hydroxyl surface functional groups is incorporated into thermoplastic materials suitable for 3-D printing AM by a special mixing technique. ABS is chosen in this study due to its availability. Graphene nanosheets are employed to improve the properties of the developed nanocomposites by 3-D
Pulmonary infections in the returned traveller are a common presentation. A wide variety of infections may present with pulmonary symptoms. It is important for clinicians to differentiate the cause of these symptoms. The risk of contracting certain travel-related pulmonary diseases depends on travel destination, length of stay, activities undertaken and co-morbidities. Some pathogens are found worldwide, whilst others are related to specific locations. This review article will discuss the approach to diagnosing and treating pulmonary infections in the returned traveller.
A new device designed to harvest rotational vibration energy is presented. The device is modeled as a spring-mass-damper system connected to a vibration source where a torsion rod is used as a spring element and a shearing electromagnetic induction circuit as the energy harvesting element. The device is inherently a resonant type harvester. A prototype device is tested using a purely sinusoidal vibration input and more realistic inputs consisting of wider bandwidths, multiple resonance peaks, and low amplitude noise. The performance of the prototype to realistic inputs verifies the ongoing challenge to vibration energy harvesting, namely, significant loss of performance when using broadband inputs with resonant based devices.
The effect of the maritime environment on radio frequency (RF) propagation is not well understood. In this work, we study the propagation of ad hoc 2.4 GHz and 5 GHz wireless local area network systems typically used for near-shore operation of unmanned surface vehicles. In previous work, maritime RF propagation performance is evaluated by collecting RSSI data over water and comparing it against existing propagation models. However, the multivariate effect of the maritime environment on RF propagation means that these single-domain studies cannot distinguish between factors unique to the maritime environment and factors that exist in typical terrestrial RF systems. In this work, we isolate the effect of the maritime environment by collecting RSSI data over land and over seawater at two different frequencies and two different ground station antenna heights with the same physical system in essentially the same location. Results show that our 2.4 GHz, 2 m antenna height system received a 2 to 3 dBm path loss when transitioning from over-land to over-seawater (equivalent to a 25 to 40% reduction in range); but increasing the frequency and antenna height to 5 GHz, 5 m respectively resulted in no meaningful path loss under the same conditions; this reduction in path loss by varying frequency and antenna height has not been demonstrated in previous work. In addition, we studied the change in ground reflectivity coefficient, R , when transitioning from over-land to over-seawater. Results show that R remained relatively constant, −0.49 ≤ R ≤ −0.45, for all of the over-land experiments; however, R demonstrated a frequency dependence during the over-seawater experiments, ranging from −0.39 ≤ R ≤ −0.33 at 2.4 GHz, and −0.51 ≤ R ≤ −0.50 at 5 GHz.
In transportation sector, there is an increasing need for joining dissimilar materials for lightweight structures; however, substantial barriers to the joining of dissimilar materials have led to an investigation and development of new joining techniques. Friction stir blind riveting (FSBR), a newly invented method, has shown great promise in joining complex structures with dissimilar materials. The process can be utilized more effectively if knowledge regarding the failure mechanisms of the FSBR joints becomes available. This research focuses on investigating the different mechanisms that lead to a failure in FSBR joints under lap-shear tensile tests. An in situ, nondestructive, acoustic emission (AE) testing method was applied during quasi-static tensile tests to monitor the initiation and evolution of damage in FSBR joints with different combinations of dissimilar materials (including aluminum, magnesium, and a carbon-fiber reinforced polymeric composite). In addition, a fractographic analysis was conducted to characterize the failure modes. Finally, based on the analysis, the distinct failure modes and damage accumulation processes for the joints were identified. An AE accumulative hit history curve was found to be efficient to discriminate the deformation characteristics, such as the deformation zone and failure mode, which cannot be observed through a traditional extensometer measurement method. In addition, the AE accumulative hit history curve can be applied to predict the failure extension or moment of FSBR joints through an identification of the changes in curve slope. Such slope changes usually occur around the middle of Zone II, which is defined in this study.
IntroductionPneumococcal colonisation is regarded as a pre-requisite for developing pneumococcal disease. In children previous studies have reported pneumococcal colonisation to be a symptomatic event and described a relationship between symptom severity/frequency and colonisation density. The evidence for this in adults is lacking in the literature. This study uses the experimental human pneumococcal challenge (EHPC) model to explore whether pneumococcal colonisation is a symptomatic event in healthy adults. MethodsHealthy participants aged 18-50 were recruited and inoculated intra-nasally with either Streptococcus pneumoniae (serotypes 6B, 23F) or saline as a control. Respiratory viral swabs were obtained prior to inoculation. Nasal and non-nasal symptoms were then assessed using a modified Likert score between 1 (no symptoms) to 7 (cannot function). The rate of symptoms reported between the two groups was compared and a correlation analysis performed. ResultsData from 54 participants were analysed. 46 were inoculated with S. pneumoniae (29 with serotype 6B, 17 with serotype 23F) and 8 received saline (control). In total, 14 became experimentally colonised (30.4%), all of which were inoculated with serotype 6B. There was no statistically significant difference in nasal (p = 0.45) or non-nasal symptoms (p = 0.28) between the inoculation group and the control group. In those who were colonised there was no direct correlation between colonisation density and symptom severity. In the 22% (12/52) who were co-colonised, with pneumococcus and respiratory viruses, there was no statistical difference in either nasal or non-nasal symptoms (virus positive p = 0.74 and virus negative p = 1.0). PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0229558 March 10, 2020 1 / 12 OPEN ACCESS Citation: Trimble A, Connor V, Robinson RE, McLenaghan D, Hancock CA, Wang D, et al. (2020) Pneumococcal colonisation is an asymptomatic event in healthy adults using an experimental human colonisation model. PLoS ONE 15(3): e0229558. https://doi.org/10.
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