Chemical and Biomedical Engineering _Vaporized Hydrogen Peroxide N95 Decontamination Summary

Summary evaluation of Vaporized Hydrogen Peroxide for the decontamination of N95 filtering facepiece respirators by Caitlin Howell, Department of Chemical and Biomedical Engineering, University of Maine

S8E10: How can nature-inspired engineering improve human health?

Antibiotic resistance has become a growing problem in the treatment of bacterial infections. In addition to minimizing or negating the effects of existing medicine, these antibiotic-resistant bacteria, or “superbugs,” are mutating faster than the development of new remedies. Caitlin Howell, University of Maine associate professor of biomedical engineering, is working on new tools that take notes from nature to combat antibiotic-resistant bacteria. Similar to the way in which the human body keeps balance with its own bacterial populations, Howell’s devices use nontoxic, non-invasive surface-based technology to trap bacteria and prevent them from spreading. In this episode of “The Maine Question” podcast, Howell discusses how nature can inspire engineers when developing new resources for improving human health. She elaborates on her research developing technology that can help reduce infections among hospital patients

In situ investigations of biological molecules using vibrational sum-frequency-generation spectroscopy

The molecular-level understanding of biological molecules on solid surfaces is critical in areas including medicine, biologically-based industry, and the development of biotechnologies. In order to gain further knowledge of the orientation and organization of biological molecules adsorbed on surfaces, we used the label-free, interface-specific technique of sum-frequency generation (SFG) spectroscopy. This technique has the distinct advantage of being able to be operated in situ as well as ex situ, allowing for direct comparison of changes in biological molecules between these two states. Films of surface-bound single-stranded DNA (ssDNA) on gold were chosen as model biological systems due to their numerous applications in genetic profiling, nano-assembly, and bio-computing, as well as their relative simplicity as biomolecular layers. Sensitivity and proof-of-principle tests on simple surface-bound, short alkane chains demonstrated the ability of SFG spectroscopy to detect molecular concentrations low enough to be useful in the investigation of biological molecules and to accurately detect the interactions of water with model hydrophobic and hydrophilic self-assembled monolayers. Investigations of multilayers of thymine, adenine, and cytosine nucleobases alone revealed a high degree of order in the thymine layers, with the signals from the methyl group unique to this base clearly visible. Films of both thiolated and non-thiolated surface-bound DNA in air showed little and moderate orientation, respectively, with the methylene stretches of the sugar-phosphate backbone dominating the spectra. Comparison of the changes in signal intensity among thymine, adenine, and cytosine ssDNA films in air and in H2O revealed differences in their solubility, which agreed with current ex situ knowledge of the manner in which these differing DNA types adsorb on gold surfaces. These experiments also revealed the appearance of nucleobase-specific spectra upon exposure to water, which was tied to the higher mobility of the sugar-phosphate backbone under these conditions. Investigations of hybridized ssDNA films in air using SFG spectroscopy indicated that the hybridization process in surface-bound DNA molecules does not necessarily correspond with an increase in molecular order, as is known to happen with DNA molecules in solution, and furthermore that even gentle processing of such hybridized samples for ex situ analysis can significantly disrupt the hybrid structure. These results were confirmed using near-edge absorbtion fine structure spectroscopy. Finally, the results obtained from the model DNA films were applied to a more complex biomolecule, fibronectin, on gold surfaces. Experiments showed that SFG spectroscopy could detect a fibronectin film even under a layer of fixed cells. Further tests on living cells over alkanethiol self-assembled monolayers confirmed this observation. These results give new information on the orientation and organization of DNA films on solid surfaces both in and ex situ, and show how this knowledge can be applied to more complex biological systems. Furthermore, this work contributes to a knowledge base for the application of SFG spectroscopy to future questions in which the label-free, in situ knowledge of surface-bound biological molecules is of critical importance

Decay Resistance Properties of Hot Water Extracted Oriented Strandboard

The use of extracted wood hemicelluloses as a substrate for fermentation and biofuels production has the added benefit of leaving the remaining wood product intact after extraction and being usable in other applications. However, it is still unclear how these extraction procedures might affect susceptibility to fungal attack. Modified oriented strandboards (OSB) were created by hot water extracting red maple strands before adhesive application and pressing of the strands into boards. Treated and untreated boards were tested for decay susceptibility in a modified ASTM soil block jar bioassay using multiple species of white and brown rot fungi. Results showed no significant differences in decay susceptibility between the untreated and extracted boards for all the brown rot fungi tested. The white rot fungi tested were shown to decay the boards made from extracted strands significantly less than the boards made from control strands. These results indicate that modifying OSB panels by removing hemicelluloses for use in ethanol and other alternative fuel production does not increase decay susceptibility to the brown rot fungi tested and appears to confer a degree of decay resistance against the white rot fungi

S4E9: How can we get the most out of technology?

Refrigerators tell us when we’re out of juice. Digital assistants schedule appointments and alert us to the weather forecast. Driverless cars slide into tight parallel parking spaces. Today, many of us increasingly rely on devices, apps and artificial intelligence in our daily lives. How can technology be designed to do the most good? How can scientists make it easy to use and put people, rather than the technology, in charge? This is the work of the University of Maine VEMI Lab. VEMI stands for Virtual Environment and Multimodal Interaction. This week, directors Rick Corey, Nick Giudice and Caitlin Howell talk with host Ron Lisnet about the lab’s mission, its many projects, and the answer to the question: How can we get the most out of technology

The role of feedback and follow up in ambulance services: a qualitative interview study

Background: International studies have shown that the feedback that ambulance staff receive lacks structure, relevance, credibility and routine implementation (Cash, 2017; Morrison, 2017). Research from psychology and implementation science suggests that feedback can change professional behaviour, improve clinical outcomes and positively influence staff mental health (Ivers, 2012; Michie and Williams, 2003). The aim of this study was to explore the experience of ambulance staff regarding current feedback provision and their views on how feedback impacts on patient safety, staff wellbeing and professional development. Methods: A qualitative study conducted as part of a wider study of work-related wellbeing in ambulance staff. 25 semi-structured interviews with prehospital staff in a clinical role from a UK ambulance service sampled using theoretical sampling. Theoretically-informed thematic analysis using psychological theory linked to the self-motives framework for feedback-seeking behaviour. Results: Study participants viewed current feedback provision as inadequate and consistently expressed a desire for increased feedback. Participants raised concerns that inadequate feedback could negatively impact on patient safety by preventing learning from mistakes. Enhancing feedback provision was suggested to improve patient safety by supporting professional development and clinical decision-making, through facilitating reflection, knowledge acquisition and professional behaviour change. Similarly, participants thought that enhanced feedback could improve staff wellbeing by enabling closure and encouraging intra-professional dialogue and peer-support. The self-motives framework was useful in interpreting personal and professional motivators for feedback-seeking behaviour within the data. Conclusions: In accordance with previous research in this area, this study highlights prehospital clinicians’ strong desire for feedback. Furthermore, it suggests that enhancing prehospital feedback could improve patient safety by enriching clinical decision-making and supporting professional development, as well as promote staff wellbeing. Findings from this initial study will be used to guide a PhD programme to address this evidence gap

Lubricant-Infused Nanoparticulate Coatings Assembled by Layer-by-Layer Deposition

Omniphobic coatings are designed to repel a wide range of liquids without leaving stains on the surface. A practical coating should exhibit stable repellency, show no interference with color or transparency of the underlying substrate and, ideally, be deposited in a simple process on arbitrarily shaped surfaces. We use layer-by-layer (LbL) deposition of negatively charged silica nanoparticles and positively charged polyelectrolytes to create nanoscale surface structures that are further surface-functionalized with fluorinated silanes and infiltrated with fluorinated oil, forming a smooth, highly repellent coating on surfaces of different materials and shapes. We show that four or more LbL cycles introduce sufficient surface roughness to effectively immobilize the lubricant into the nanoporous coating and provide a stable liquid interface that repels water, low-surface-tension liquids and complex fluids. The absence of hierarchical structures and the small size of the silica nanoparticles enables complete transparency of the coating, with light transmittance exceeding that of normal glass. The coating is mechanically robust, maintains its repellency after exposure to continuous flow for several days and prevents adsorption of streptavidin as a model protein. The LbL process is conceptually simple, of low cost, environmentally benign, scalable, automatable and therefore may present an efficient synthetic route to non-fouling materials.Chemistry and Chemical Biolog

Spectral Energy Distributions of Local Luminous And Ultraluminous Infrared Galaxies

Luminous and ultraluminous infrared galaxies ((U)LIRGs) are the most extreme star forming galaxies in the universe. The local (U)LIRGs provide a unique opportunity to study their multi-wavelength properties in detail for comparison to their more numerous counterparts at high redshifts. We present common large aperture photometry at radio through X-ray wavelengths, and spectral energy distributions (SEDs) for a sample of 53 nearby LIRGs and 11 ULIRGs spanning log (LIR/Lsun) = 11.14-12.57 from the flux-limited Great Observatories All-sky LIRG Survey (GOALS). The SEDs for all objects are similar in that they show a broad, thermal stellar peak and a dominant FIR thermal dust peak, where nuLnu(60um) / nuLnu(V) increases from ~2-30 with increasing LIR. When normalized at IRAS-60um, the largest range in the luminosity ratio, R(lambda)=log[nuLnu(lambda)/nuLnu(60um)] observed over the full sample is seen in the Hard X-rays (HX=2-10 keV). A small range is found in the Radio (1.4GHz), where the mean ratio is largest. Total infrared luminosities, LIR(8-1000um), dust temperatures, and dust masses were computed from fitting thermal dust emission modified blackbodies to the mid-infrared (MIR) through submillimeter SEDs. The new results reflect an overall ~0.02 dex lower luminosity than the original IRAS values. Total stellar masses were computed by fitting stellar population synthesis models to the observed near-infrared (NIR) through ultraviolet (UV) SEDs. Mean stellar masses are found to be log(M/Msun) = 10.79+/-0.40. Star formation rates have been determined from the infrared (SFR_IR~45Msun/yr) and from the monochromatic UV luminosities (SFR_UV~1.3Msun/yr), respectively. Multiwavelength AGN indicators have be used to select putative AGN: about 60% of the ULIRGs would have been classified as an AGN by at least one of the selection criteria.Comment: 39 pages, including 12 figures and 11 tables; accepted for publication in ApJ

Self-Replenishing Vascularized Fouling-Release Surfaces

Inspired by the long-term effectiveness of living antifouling materials, we have developed a method for the self-replenishment of synthetic biofouling-release surfaces. These surfaces are created by either molding or directly embedding 3D vascular systems into polydimethylsiloxane (PDMS) and filling them with a silicone oil to generate a nontoxic oil-infused material. When replenished with silicone oil from an outside source, these materials are capable of self-lubrication and continuous renewal of the interfacial fouling-release layer. Under accelerated lubricant loss conditions, fully infused vascularized samples retained significantly more lubricant than equivalent nonvascularized controls. Tests of lubricant-infused PDMS in static cultures of the infectious bacteria Staphylococcus aureus and Escherichia coli as well as the green microalgae Botryococcus braunii, Chlamydomonas reinhardtii, Dunaliella salina, and Nannochloropsis oculata showed a significant reduction in biofilm adhesion compared to PDMS and glass controls containing no lubricant. Further experiments on vascularized versus nonvascularized samples that had been subjected to accelerated lubricant evaporation conditions for up to 48 h showed significantly less biofilm adherence on the vascularized surfaces. These results demonstrate the ability of an embedded lubricant-filled vascular network to improve the longevity of fouling-release surfaces.Engineering and Applied Science