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Laryngoscope blades used to intubate newborn babies are relatively bulky and frequently exert high pressure on the upper jaw. We tested a prototype neonatal offset-blade laryngoscope (NOBL) developed to overcome these limitations. Our aims were to compare the pressure on the upper jaw exerted by a size 0 Miller laryngoscope and the NOBL on a neonatal manikin, as well as the time taken to intubate the trachea and the area of view of the larynx. Twenty healthcare professionals with more than five years of experience in neonatal intensive care took part; the findings were assessed using pressure-sensitive film and photographs. High-pressure indentation occurred in 17 (85%) attempts using the Miller versus 1 (5%) using the NOBL (p = 0.0001). The median (IQR [range]) pressure exerted with the Miller laryngoscope was 455 (350-526 [75-650]) kPa vs 80 (0-133 [0-195]) kPa with the NOBL (p < 0.0001). The area of pressure exerted with the Miller laryngoscope was 68 (32-82 [0-110]) mm(2) vs 8 (0-23 [0-40]) mm(2) with the NOBL (p < 0.0001). The time to intubate was 8.3 (7.3-10.1[4-19]) s for the Miller and 8.0 (5.6-9.6 [4-13.5]) s for the NOBL (p < 0.0001). The area of view blocked by the Miller laryngoscope was 38% of the oral orifice versus 12% with the NOBL. We conclude that the NOBL significantly reduced undesired pressure on the upper jaw during tracheal intubation and improved the view of the larynx compared with a conventional laryngoscope.

Two-dimensional (2D) materials have attracted much attention over the last decade due to their high performance in nanoelectronic devices. The discovery of graphene opened up many opportunities to investigate and explore other 2D materials. There has been a drive to expand the toolbox of 2D materials to also include insulators and semiconductors with a variety of bandgaps. As a result, a wide range of materials have been discovered or predicted,1 with molybdenum disulfide (MoS2) being particularly popular. The semiconducting phase of MoS2 (2H-MoS2) is one of the most commonly studied among the transition metal dichalcogenides.2 It has a thickness dependent band gap which has drawn attention for field-effect transistors (FET) where a high on/off current ratio is desired.3-5 However, for applications in batteries,6supercapacitors,7 and solar cells,8 a substantially increased conductivity is required in order to achieve reasonable currents. Using 2H-MoS2 requires a relatively high voltage to get sufficient conductivity due to the presence of a band gap. The most common source of conductive MoS2 is metallic MoS2 (1T-MoS2) that has been prepared via the lithium intercalation process, which requires inert atmosphere processing and safety procedures.9 Hence, there is a desire to develop a safer and more efficient process to yield conductive MoS2. Defects plays a very important role in modulating the electrical properties of MoS2. Sonication of MoS2 in an appropriate solvent results in many disordered structural defects. The most common defects on MoS2 are sulfur defects.10 These defects increase the energy level of the gap state and eventually deteriorate the device performance. Thiol based molecules are commonly used to reduce the number of sulfur defects on MoS2.11 Other molecules such as oxygen or organic super acids like bis(trifluoromethane) sulfonamide (TFSI) have also been reported to passivate the surface defect.12,13 Past research has mainly focused on the theoretical study of defective MoS2 and how to utilize those defects for improving photoluminescent efficiency. However, those defects can also be utilized to improve the conductivity of MoS2 as a safer alternative for applications in batteries, supercapacitors, solar cells and sensors. In this work, we show a simple and effective way to prepare few layer conductive MoS2 under ambient conditions. We have demonstrated that the sheet resistance of the conductive MoS2 that we prepared is up to five orders of magnitude higher than that of the semiconducting phase of MoS2, depending on the dopant concentration. The samples were also characterized with Hall measurements, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. An important goal of our work is to control the conductivity of the MoS2 thin films in safe and facile ways that enable their application in low-cost chemiresistive sensors in liquid environments. We fabricated chemiresistive pH sensors with centimeter channel lengths while maintaining low measurement voltages. Our study furthers the understanding of conductive forms of MoS2, and also opens a new pathway for next generation electronic devices. References: 1. M. D. Segall et al., J. Phys.: Condens. Matter, 14, 2717–2744 (2002). 2. H. Wan et al., RSC Adv., 5, 7944 (2015). 3. D. Kiriya et al., J. Am. Chem. Soc., 136, 7853−7856 (2014). 4. H. Fang et al., Nano Lett., 13, 1991−1995 (2013). 5. M. Choi et al., ACS Nano, 8, 9332-9340 (2014). 6. T. Stephenson et al., Energy Environ. Sci., 7, 209-231 (2014). 7. L. Cao et al., Small, 9, 2905–2910 (2013). 8. M.-L.Tsai et al., ACS Nano, 8, 8317-8322 (2014). 9. G. Eda et al., Nano Lett., 11, 5111–5116 (2011). 10. A. Dabral et al., Phys. Chem. Chem. Phys., 21, 1089-1099 (2019). 11. D. M. Sim et al., ACS Nano, 9, 12115-12123 (2015). 12. K. C. Santosh et al., J. Appl. Phys., 117, 135301 (2015). 13. H. Lu et al., APL Mater., 6, 066104 (2018). Figure 1

Silver is a precious metal that is commonly used in water filters to reduce growth of biofilm within the filter itself. Ionic silver is used as an effective disinfectant for potable water, giving a log10 reduction for L. pneumophilia, P. aeruginosa, and E. coli of 2.4, 4, and 7, respectively.1 In terms of human exposure, silver is not an essential metal therefore any exposure to silver is unwanted. When silver is ingested orally, the most common adverse effect is argyria, which is an extreme blue pigmentation of the skin and abdominal viscera.2 Occupational exposure to silver nitrate has been correlated to respiratory tract irritation.3 Currently there are no guidelines for silver ions in drinking water, and the World Health Organization (WHO) has set a health advisory (not a guideline value) of 100 ppb. The only country with a Maximum Allowable Content (MAC) is Germany, whose drinking water regulations (Trinkwasserverordnung) have a MAC of 80 ppb.4 Here we demonstrate a chemiresistive sensor for the in situ detection of silver (I) in aqueous media. Chemiresistive sensors function through the changes that occur in the electronic structure of the sensor itself. A graphite film attached to two copper contacts at either end is exposed to the silver ions such that only the graphite and not the contacts interact with the ions. To functionalize the graphite, silver (I)-specific ligands, such as bathocuproine, can be deposited onto the film to adsorb onto it, protecting it from interfering ions.5 Chemiresistive sensors have been demonstrated before for the detection of free chlorine in aqueous media. Rather than using graphite, carbon nanotubes (CNT) were utilized as the conductive film, with phenyl-capped aniline tetramer (PCAT) as the chlorine-specific ligand. As the PCAT doped CNT was exposed to chlorine, the PCAT oxidized, and the electronic changes were probed using a bias voltage. The linear range for this sensor was from 60 ppb to 60 ppm, providing sufficient sensitivity for household use.6 When testing other common ions, there were no significant interference's that compete with the response of silver (I) in solution, making this sensor quite selective to silver (I). pH tests show that there is no change in current induced by pH between the range of 6-10 pH. Below 6, the sensor functions as a "proton sensor" due to the protonation of the adsorbed bathocuproine. Above pH 10, AgOH may be formed, which will precipitate out of solution. All tests were performed at an analyte conductance of 31 μS/cm, which is typical for freshwater samples.7 When the fabricated sensor was exposed to silver (I) in aqueous solution, detection of the ions was observed through a step up in the current going through the sensor. Each step up in current was proportional to the concentration of silver (I) in solution. Based on this, a calibration curve was made using the Langmuir Isotherm model and a first-order exponential decay model. For the range of 3 ppb to 1 ppm, both the Langmuir Isotherm and the first-order exponential decay model gave R2 values of 0.9982 and 0.9939, respectively. The sensor could also be reliably reset to the same 0 ppm baseline after use by exposing it to a pH 3 solution. When exposed to silver (I) post-reset, current changes were also quite reproducible, with the values having a relative standard deviation no greater than 1.24%, highlighting the re-usability of this sensor. The limit of detection, calculated using a signal:noise ratio of 3, for this sensor would be 3 ppb. We have therefore demonstrated that chemiresistors based on functionalized nanocarbon films can be used as selective ion sensors in addition to their previously demonstrated application as redox sensors. The toolbox of organometallic chemistry can now be applied to extend this sensing platform to other cations for water quality sensing. References 1. Kim, J. S.; Kuk, E.; Yu, K. N.; Kim, J.-H.; Park, S. J.; Lee, H. J.; Kim, S. H.; Park, Y. K.; Park, Y. H.; Hwang, C.-Y.; et al. Antimicrobial Effects of Silver Nanoparticles. Nanomedicine: Nanotechnology, Biology and Medicine 2007, 3 (1), 95–101. 2. Marshall, J. P. Systemic Argyria Secondary to Topical Silver Nitrate. Archives of Dermatology 1977, 113 (8), 1077. 3. Toxicological Profile for Silver. Agency for Toxic Substances and Disease Registry 1990. 4. Silver as a Drinking-Water Disinfectant. World Health Organization 2018. 5. Saito, T. Transport of Silver(I) Ion through a Supported Liquid Membrane Using Bathocuproine as a Carrier. Separation Science and Technology 1998, 33 (6), 855–866. 6. Hsu, L. H. H.; Hoque, E.; Kruse, P.; Selvaganapathy, P. R. A Carbon Nanotube Based Resettable Sensor for Measuring Free Chlorine in Drinking Water. Applied Physics Letters 2015, 106 (6), 063102. 7. https://www.ontario.ca/data/provincial-stream-water-quality-monitoring-network (accessed on October 22, 2019) Figure 1

Background and aims Aetiology of BPD is multifactorial with prenatal and postnatal factors being involved. First, we aimed to evaluate the association between chorioamnionitis and BPD. Secondly, the effect of other perinatal factors on the risk of developing BPD were analysed. Methods Retrospective analysis of all infants with GA <32 weeks or BW <1500 g. admitted into our hospital between 2002-2010. 120 patients who died before 36 weeks of PMA were excluded. Results The average GA was: 29,7 ± 3 s; 217/432 (50%) had any type of chorioamnionitis (histological or clínical); 75/432 (17.4%) met diagnostic criteria for BPD at 36 weeks.Univariate analysis: lower GA, any type of chorioamnionitis, DAP and duration of mechanical ventilation (MV) were associated with an increased risk of DBP (p < 0.05).Multivariate analysis: administration of antenatal steroids or chorioamnionitis did not independently modify the risk of BPD. But adding both, the effect became statistically significant protective for BPD (OR 0.52, 95% CI 0.03 to 0.79).Days in MV is the only factor that independently increased the risk of BPD. Neither a lower GA nor the presence of PDA had significantance; but, the risk of BPD was higher in the presence of PDA and MV together: every day in MV increased the risk of BPD (OR 1.130, 95% CI1.001-1.27). Conclusions Chorioamnionitis in coexistence with antenatal corticosteroids decreases the risk of BPD. Mechanical ventilation is the main risk factor for BPD. In the presenceof DAP, ventilation increases the risk of BPD. Background Endotracheal intubation (EI) is currently required for surfactant administration. However, EI is associated with adverse physiologic effects, including bradycardia and hypoxia. The laryngeal mask airway (LMA) may provide a more practical and less invasive alternative to EI for surfactant administration. Aim Determine feasibility of LMA placement in neonates by investigating the time, number of attempts and physiologic stability during placement of the device. Methods Infants ≥1250 g who required surfactant administration were eligible. Videotape of the LMA placement procedure was reviewed to determine number of attempts, duration of attempts, total procedure time, and heart rate and oxygen saturation change from baseline. Results Twenty-two infants were included in analysis. Mean total procedure time was 129 seconds (±187). Duration of attempts was 59 seconds (±81). Successful placement was achieved on the first attempt in 73% of cases. Two attempts were required in 14% of cases and all procedures were successful in ≤3 attempts. As compared to baseline, heart rate increased 3 beats per minute on average (±4, range: -3 to 11) and oxygen saturation decreased by 7% on average (±8, range: -24 to 1), as shown in Figure 1. PO-0758Abstract PO-0758 Figure 1 Conclusions Successful placement was achieved in the majority of patients in one attempt with an average total procedure time of approximately 2 min. Physiologic parameters were maintained close to baseline with minimal fluctuation in heart r...