The threat of a global rise in the number of untreatable infections caused by antibiotic-resistant bacteria calls for the design and fabrication of a new generation of bactericidal materials. Here, we report a concept for the design of antibacterial surfaces, whereby cell death results from the ability of the nanofeatures to deflect when in contact with attaching cells. We show, using three-dimensional transmission electron microscopy, that the exceptionally high aspect ratio (100-3000) of vertically aligned carbon nanotubes (VACNTs) imparts extreme flexibility, which enhances the elastic energy storage in CNTs as they bend in contact with bacteria. Our experimental and theoretical analyses demonstrate that, for high aspect ratio structures, the bending energy stored in the CNTs is a substantial factor for the physical rupturing of both Gram-positive and Gram-negative bacteria. The highest bactericidal rates (99.3% for Pseudomonas aeruginosa and 84.9% for Staphylococcus aureus) were obtained by modifying the length of the VACNTs, allowing us to identify the optimal substratum properties to kill different types of bacteria efficiently. This work highlights that the bactericidal activity of high aspect ratio nanofeatures can outperform both natural bactericidal surfaces and other synthetic nanostructured multifunctional surfaces reported in previous studies. The present systems exhibit the highest bactericidal activity of a CNT-based substratum against a Gram-negative bacterium reported to date, suggesting the possibility of achieving close to 100% bacterial inactivation on VACNT-based substrata.

The spectrum of pulmonary disease caused by e-cigarette use is currently emerging and appears to be multifaceted [1]. We describe a patient who developed pathologically documented giant cell interstitial pneumonia following regular use of an e-cigarette. This disorder has been termed hard metal pneumoconiosis, or cobalt lung, due to its close association with exposure to hard metal (cemented tungsten carbide with cobalt) [2]. Analysis of the device's e-liquid revealed significant levels of cobalt, supporting a diagnosis of giant cell interstitial pneumonia associated with inhaled cobalt from regular e-cigarette use.A 49-year-old previously healthy Caucasian female presented with progressive shortness of breath on exertion. She had a non-productive cough and wheezing. She denied any other symptoms. She had recently been given a diagnosis of asthma following an adverse reaction to ketorolac injection for low back pain. At that time, she was told it could be related to her environment. Home medications included daily montelukast 10 mg tablet and albuterol inhaler p.r.n. She had recently worked as a dog trainer, but stopped due to dyspnoea. She had a remote history of smoking cigarettes in her teens and twenties. She had been using a marijuana e-cigarette (ZenPen personal vaporiser) for 6 months.Physical examination showed a well-nourished woman with blood pressure 147/88 mmHg, heart rate 73 bpm, respiratory rate 18 bpm, and oxygen saturation 96% on room air. During a walk test in clinic she desaturated to 87% on room air after 2 min, with a heart rate of 114 bpm and respiratory rate of 25 bpm. Auscultation of her lungs revealed inspiratory crackles at the bases bilaterally. Pulmonary function tests showed moderately severe restriction with a severe diffusion defect: forced vital capacity (FVC) 1.58 L (51% predicted), forced expiratory volume in 1 s (FEV 1 ) 1.28 L (50% predicted), FEV 1 /FVC 81%, total lung capacity (TLC) 2.67 L (56% predicted), diffusing capacity of the lung for carbon monoxide (D LCO ) 7.7 mL•min −1 •mmHg −1 (27% predicted) and transfer coefficient of the lung for carbon monoxide (K CO ) 4.17 mL•min −1 •mmHg −1 •L −1 (99% predicted). Computed tomography (CT) scan of the chest showed bilateral ground glass opacity and ill-defined nodules predominating in the centrilobular regions with sparing of the subpleural lung (figure 1a and b). There was no reticulation, traction bronchiectasis or honeycombing. She underwent a surgical lung biopsy for diagnosis.Standard haematoxylin and eosin-stained histological sections from the surgical lung biopsy were reviewed by light microscopy.The e-liquid from the ZenPen micro-vaporiser belonging to the patient was analysed using inductively coupled plasma mass spectrometry (ICP-MS) as described previously by HESS et al. [3]. Two aliquots from the same sample were analysed, and the mean metal concentration of the two replicates was calculated. The metals analysed were aluminium, chromium, manganese, cobalt, nickel, arsenic, molybdenum, tungsten, cadmium and lead.Glas...

Bioelectrochemical systems couple electricity demand/supply to the metabolic redox reactions of microorganisms. Generally, electrodes act not only as electron acceptors/donors, but also as physical support for an electroactive biofilm. The microorganism-electrode interface can be modified by changing the chemical and/or topographical features of the electrode surface. Thus far, studies have reported conflicting results on the impact of the electrode surface roughness on the growth and current production of biofilms. Here, the surface roughness of the glassy carbon electrodes was successfully modified at the sub-microscale using micro electrodischarge machining, while preserving the surface chemistry of the parent glassy carbon. All microbial electrodes showed similar startup time, maximum current density, charge transport ability across the biofilm and biomass production. Interestingly, an increase in the average surface cavity depth was observed for the biofilm top layer as a function of the electrode surface roughness (from 7 μm to 16 μm for a surface roughness of 5 nm to 682 nm, respectively). These results indicated that the surface roughness at a sub-microscale does not significantly impact the attachment or current production of mixed culture anodic biofilms on glassy carbon. Likely earlier observations were associated with changes in surface chemistry, rather than surface topography.