Investigation of the Efficacy of a Listeria monocytogenes Biosensor Using Chicken Broth Samples.

Foodborne pathogens are microbes present in food that cause serious illness when the contaminated food is consumed. Among these pathogens, Listeria monocytogenes is one of the most serious bacterial pathogens, and causes severe illness. The techniques currently used for L. monocytogenes detection are based on common molecular biology tools that are not easy to implement for field use in food production and distribution facilities. This work focuses on the efficacy of an electrochemical biosensor in detecting L. monocytogenes in chicken broth. The sensor is based on a nanostructured electrode modified with a bacteriophage as a bioreceptor which selectively detects L. monocytogenes using electrochemical impedance spectroscopy. The biosensing platform was able to reach a limit of detection of 55 CFU/mL in 1× PBS buffer and 10 CFU/mL in 1% diluted chicken broth. The biosensor demonstrated 83-98% recovery rates in buffer and 87-96% in chicken broth.

Biocomposite thermoplastic polyurethanes containing evolved bacterial spores as living fillers to facilitate polymer disintegration.

The field of hybrid engineered living materials seeks to pair living organisms with synthetic materials to generate biocomposite materials with augmented function since living systems can provide highly-programmable and complex behavior. Engineered living materials have typically been fabricated using techniques in benign aqueous environments, limiting their application. In this work, biocomposite fabrication is demonstrated in which spores from polymer-degrading bacteria are incorporated into a thermoplastic polyurethane using high-temperature melt extrusion. Bacteria are engineered using adaptive laboratory evolution to improve their heat tolerance to ensure nearly complete cell survivability during manufacturing at 135 °C. Furthermore, the overall tensile properties of spore-filled thermoplastic polyurethanes are substantially improved, resulting in a significant improvement in toughness. The biocomposites facilitate disintegration in compost in the absence of a microbe-rich environment. Finally, embedded spores demonstrate a rationally programmed function, expressing green fluorescent protein. This research provides a scalable method to fabricate advanced biocomposite materials in industrially-compatible processes.

Experimentally Determined Hansen Solubility Parameters of Biobased and Biodegradable Polyesters.

Hansen solubility parameters (HSP) of 15 commercially relevant biobased and biodegradable polyesters were experimentally determined by applying a novel approach to the classic solubility study method. In this approach, the extent of swelling in polymer films was determined using a simple equation based on the mass difference between swollen and nonswollen film samples to obtain normalized solvent uptake (N). Using N and HSPiP software, highly accurate HSP values were obtained for all 15 polyesters. Qualitative evaluation of the HSP values was conducted by predicting the miscibility of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHB-co-HHx, 7 mol % HHx) and poly(lactic acid) (PLA) with a novel lignin-based plasticizer (ethyl 3-(4-ethoxy-3-methoxyphenyl)propanoate, EP) with a relative energy difference (RED) less than 0.4. Additionally, an HSP-predicted plasticizer (di(2-ethylhexyl) adipate, DA) with a larger RED (>0.7) was used to demonstrate the effects of less-miscible additives. Plasticized samples were analyzed by differential scanning calorimetry and polarized optical microscopy (POM) to determine the Tg depression, with EP showing linear Tg depression up to 50% plasticizer loading, whereas DA shows minimal Tg depression past 10% loading. Further analysis by POM reveals that the DA phase separates from both polymers at loadings as low as 2.5% (PHB-co-HHx, 7 mol % HHx) and 5% (PLA), while the EP phase separates at a much higher loading of 50% (PHB-co-HHx, 7 mol% HHx) and 30% (PLA).

Weathering Effects on Degradation of Low-Density Polyethylene-Nanosilica Composite with Added Pro-oxidant.

Nanomaterials are increasingly used in polymer composites to enhance their properties, such as mechanical performance and durability, increased electrical conductivity, and improved optical clarity. Here results are presented of a study simulating effects of weathering on degradation of a nanosilica-low-density polyethylene (LDPE) composite. Release of nanosilica from LDPE composites is a potential source of toxic SiO2. Nanosilica based LDPE composites were weathered under carefully controlled conditions by exposure to simulated sunlight. The effects of an added pro-oxidant on weathering was examined. Weathering of the composites with pro-oxidant was determined by quantifying changes in infrared spectroscopic properties (Fourier transform infrared spectroscopy / FTIR); mechanical properties, atomic force microscopy (AFM), scanning electron microscopy and other procedures. Wavelength effects on weathering rates were determined in a series of irradiations using simulated solar radiation passed through light filters that blocked different parts of the ultraviolet spectral region. Rates and spectral irradiance were then analyzed to develop spectral weighting functions (SWFs) that quantify wavelength effects on the sunlight-induced weathering of the pro-oxidant amended composites.

A Biologically Degradable and BioseniaticTM Feedstock for the High-Quality 3D Printing of Anatomical Models.

A Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) -based filament was evaluated as an alternative feedstock for Fused Deposition Modeling (FDM) of instructional and clinical medical specimens. PHBHHx-based prints of domestic cat vertebrae, skull bone, and an aortic arch cast were found comparable to conventional materials. PHBHHx-based filament and extrudate samples were evaluated for biological degradability, to meet the BioseniaticTM standard, defined by the University of Georgia New Materials Institute. Both samples achieved more than 90% mineralization within 32 days in industrial composting conditions.

Recruitment of participants for dementia research: interprofessional perspectives from primary care-based memory clinics.

Aim: To understand clinician attitudes and the barriers that impede research recruitment from specialized primary care-based memory clinics. Materials & methods: Clinicians completed a survey on attitudes and barriers to research recruitment from memory clinics. Results: Comfort and willingness to recruit for research were low to moderate and were lower for drug trials than for observational and non-drug trials. Respondents believed that it is important to have a standardized recruitment process. Identified barriers provide some insights into the factors that contribute to discomfort and lack of willingness to recruit research participants. Discussion: Findings can inform future efforts to develop a recruitment process that addresses identified barriers, while also providing an opportunity to increase participant recruitment in dementia research.

Recruitment of persons living with dementia from primary care for research is challenging and can be a barrier to study completion. Multispecialty Interprofessional Team (MINT) Memory Clinics may provide a unique opportunity for recruiting patients for research studies. In this study, clinicians completed a survey on attitudes and barriers to research recruitment from memory clinics in primary care. Clinician comfort and willingness to recruit for research were low to moderate. A number of barriers to recruiting patients for research from MINT Clinics were identified and included limited time, workload issues, limited information to share with patients, and their lack of knowledge about and experience with research. These study findings can help to develop a recruitment process that addresses identified barriers and helps to increase participant recruitment in dementia research.

Comparative Study of the Biological Degradation of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) Microbeads in Municipal Wastewater in Environmental and Controlled Laboratory Conditions.

From April to June 2019, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3(HA)) microbead samples were exposed to an operational wastewater reclamation facility (WWRF) in an aerobic aeration basin in Athens, Georgia. Samples were withdrawn from the facility over a 13-week timeframe, and the particles were examined by Raman microscopy and thermogravimetric analysis/mass spectroscopy (TGA/MS) coupled with differential scanning calorimetry (DSC). The activated sludge from this facility was also used as an inoculum to examine carbon mineralization under controlled respirometry experiments to corroborate biological degradation rates determined from both the environmental and laboratory approach. Respirometry, Raman microscopy, and TGA/MS-DSC methods all measured similar biodegradation timelines for microbeads bound to an epoxy substrate, indicating that the three methods are temporally comparable and may be used to measure material biological degradation. Samples of epoxy-bound P3(HA) microbeads, free microbeads, the P3(HA) film, and poly(lactic acid) (PLA) film demonstrated carbon mineralization of 90.0, 89.4, 95.0, and 8.15%, respectively, relative to the cellulose positive control. Using a modified Gompertz growth model, the biological degradation rate coefficients (Rm) were determined for cellulose, P3(HA) film, epoxy-bound P3(HA) microbeads, and free P3(HA) microbeads and found to be 31.6, 30.2, 17.5, and 18.7 mL CO2·g-1·day-1, respectively. Moreover, P3(HA) microbeads can efficiently mineralize in WWRF infrastructure at a rate comparable to cellulose.

Can Standard Health Technology Assessment Approaches Help Guide the Price of Orphan Drugs in Canada? A Review of Submissions to the Canadian Agency for Drugs and Technologies in Health Common Drug Review.

Orphan drugs have high acquisition costs and when standard health technology assessment (HTA) approaches are used to assess their cost-effectiveness, they often appear not cost-effective. The Canadian Patented Medicine Review Board (PMPRB), through new regulations, will apply HTA assessment results from the Canadian Agency for Drugs and Technologies in Health (CADTH) and Institut national d'excellence en santé et en services sociaux (INESSS) when setting the maximum price that can be charged for Category I patented medicines (treatments with an annual cost exceeding 150% of GDP per capita of Canada or with expected annual market size >$50M). Through these regulations, PMPRB has also established a willingness-to-pay threshold of CAD$200,000 or CAD$150,000 per quality adjusted life year (QALY) for medications with a prevalence of no more than 1 in 2000 across all approved indications. We reviewed the orphan drug submissions made to CADTH's Common Drug Review (CDR) January 2015-May 2020 to understand how the methodology of assessing cost-effectiveness of orphan drugs has guided pricing in Canada. A total of 35 orphan drug submissions were assessed by CDR in this period, none of which met the willingness-to-pay threshold of CAD$50,000 per QALY. Only one drug met the CAD$200,000 per QALY for Therapeutic Criteria Level I, and two drugs met CAD$150,000 per QALY for other Therapeutic Criteria Levels proposed by PMPRB. Price reductions of 32-99% were recommended for treatments that were approved in order to be listed for reimbursement. This review showed that the new PMPRB regulations could be creating challenges for manufacturers of rare disease treatments to meet Canadian pricing regulations. These regulations may jeopardize the launch of new medicines and limit opportunities to add to the development of real-world evidence of orphan drugs, which can be used in reimbursement approaches such as pay-for-performance.

Distinct Mycoplasma pneumoniae Interactions with Sulfated and Sialylated Receptors.

Mycoplasma pneumoniae is a cell wall-less bacterial pathogen of the conducting airways, causing bronchitis and atypical or "walking" pneumonia in humans. M. pneumoniae recognizes sialylated and sulfated oligosaccharide receptors to colonize the respiratory tract, but the contribution of the latter is particularly unclear. We used chamber slides coated with sulfatide (3-O-sulfogalactosylceramide) to provide a baseline for M. pneumoniae binding and gliding motility. As expected, M. pneumoniae bound to surfaces coated with sulfatide in a manner that was dependent on sulfatide concentration and incubation temperature and inhibited by competing dextran sulfate. However, mycoplasmas bound to sulfatide exhibited no gliding motility, regardless of receptor density. M. pneumoniae also bound lactose 3'-sulfate ligated to an inert polymer scaffold, and binding was inhibited by competing dextran sulfate. The major adhesin protein P1 mediates adherence to terminal sialic acids linked α-2,3, but P1-specific antibodies that blocked M. pneumoniae hemadsorption (HA) and binding to the sialylated glycoprotein laminin by 95% failed to inhibit mycoplasma binding to sulfatide, suggesting that P1 does not mediate binding to sulfated galactose. Consistent with this conclusion, the M. pneumoniae HA-negative mutant II-3 failed to bind to sialylated receptors but adhered to sulfatide in a temperature-dependent manner.

Photocross-linking Kinetics Study of Benzophenone Containing Zwitterionic Copolymers.

The kinetics of benzophenone (BP) and its derivatives have been widely studied in different solvents by nanosecond laser flash photolysis as well as in the polymer matrix. With the development of functional polymer coating, BP, as well as other photocross-linkers, has been incorporated into the polymer backbone or side chain to form the covalent connection between polymer coatings and substrates, which can improve the mechanical and chemical stability of the coatings. In this work, a series of BP pendent zwitterionic copolymer kinetics were investigated using UV-vis for the first time. Because of the high hydrophilicity of the zwitterionic monomer, the influence of the polymer matrix's polarity on the cross-linking rate was observed. With a higher zwitterionic percentage in the copolymer, the polarity of the copolymer increases, BP reactivity decreases, and a hypothesis between the BP rate constant and partial coefficient log P was raised. Moreover, the thermal property is also an important factor affecting the BP reactivity. For polymers with high glass-transition temperature, the reactivity was not dominated by the chemical environment such as polarity, and the restricted segment movement reduces the cross-linking rate. Additionally, the ring substituents show similar effects to BP pendent copolymers as with small molecules. Electron-withdrawing groups help to stabilize the BP triplet radical and facilitate cross-linking, while electron-donating groups work conversely. Therefore, polarity, thermal properties, and substituents should be taken into consideration when designing BP-containing functional polymers.

Multipronged Approach to Combat Catheter-Associated Infections and Thrombosis by Combining Nitric Oxide and a Polyzwitterion: a 7 Day In Vivo Study in a Rabbit Model.

The development of nonfouling and antimicrobial materials has shown great promise for reducing thrombosis and infection associated with medical devices with aims of improving device safety and decreasing the frequency of antibiotic administration. Here, the design of an antimicrobial, anti-inflammatory, and antithrombotic vascular catheter is assessed in vivo over 7 d in a rabbit model. Antimicrobial and antithrombotic activity is achieved through the integration of a nitric oxide donor, while the nonfouling surface is achieved using a covalently bound phosphorylcholine-based polyzwitterionic copolymer topcoat. The effect of sterilization on the nonfouling nature and nitric oxide release is presented. The catheters reduced viability of Staphylococcus aureus in long-term studies (7 d in a CDC bioreactor) and inflammation in the 7 d rabbit model. Overall, this approach provides a robust method for decreasing thrombosis, inflammation, and infections associated with vascular catheters.

Fully Synthetic Heparan Sulfate-Based Neural Tissue Construct That Maintains the Undifferentiated State of Neural Stem Cells.

Heparin and heparan sulfate (HS) are attractive components for constructing biomaterials due to their ability to recruit and regulate the activity of growth factors. The structural and functional heterogeneity of naturally derived heparin and HS is, however, an impediment for the preparation of biomaterials for regenerative medicine. To address this problem, we have prepared hydrogels modified by well-defined synthetic HS-derived disaccharides. Human induced pluripotent cell-derived neural stem cells (HIP-NSCs) encapsulated in a polyethylene glycol-based hydrogel modified by a pendent HS disaccharide that is a known ligand for fibroblast growth factor-2 (FGF-2) exhibited a significant increase in proliferation and self-renewal. This observation is important because evidence is emerging that undifferentiated stems cells can yield significant therapeutic benefits via their paracrine signaling mechanisms. Our data indicate that the HS disaccharide protects FGF-2, which has a very short biological half-live, from degradation. It is anticipated that, by careful selection of a synthetic HS oligosaccharide, it will be possible to control retention and release of specific growth factor, which in turn will provide control over cell fate.

Specialist and family physician collaboration: Insights from primary care-based memory clinics.

Given limited available geriatric specialists and complexity of dementia care, there is a need for greater collaboration between primary care and specialists to better meet the needs of persons with dementia. Meaningful family physician-specialist collaboration has the potential to improve health outcomes, timely access to care and more appropriate healthcare resource utilisation. Primary Care Collaborative Memory Clinics (PCCMCs), which include specialist support, provide a significant opportunity for studying the family physician-specialist interface. This study aimed to explore the nature of collaborative relationships between memory clinic family physicians and specialists caring for persons with memory concerns in PCCMCs across Ontario, Canada. Family physicians (N = 71) attending an education session and specialists (N = 21) completed a survey in the fall of 2017 that measured frequency and amount of collaboration, perceptions of their relationship and identified factors that enable and challenge collaboration. Descriptive statistics were generated for quantitative data and themes for responses to open-ended questions were explored using descriptive qualitative content analysis. Specialists and memory clinic family physicians valued their collaboration particularly as related to capacity building for dementia care and desired more time devoted to collaboration. Identified enablers and barriers to collaboration have implications for further integration of specialist support to potentially support improved patient care and further build capacity in primary care to manage dementia care. Opportunities exist for expanding and more intentionally supporting how family physicians and specialists interact with the creation of more formalised processes to support optimal collaboration, including a clear delineation of roles, responsibilities and expectations, more formally planned and structured relationship building and monitoring, identifying and addressing unique barriers to collaboration and use of a variety of methods of communication. Study findings have implications for how specialists and family physicians communicate and collaborate in other programmes for complex chronic conditions.

SuFEx-based strategies for the preparation of functional particles and cation exchange resins.

A predictable and reproducible number of sulfuric acid sites have been achieved for cation exchange resins by employing a mild SuFEx-based reagent system to effect the hydrolysis of fluorosulfonated polymer beads. The resultant poly(hydrogen sulfate) beads effectively demonstrate their utility as cation exchange resins in ion-capture experiments. Furthermore, their polyfluorosulfonated precursors have also proven to be suitable substrates for traditional SuFEx-type click reactions in both small molecule and protein immobilization applications.

Advanced Care Planning for Persons With Dementia in Primary Care: Attitudes and Barriers Among Health-Care Professionals.

BACKGROUND: Advance care planning (ACP) provides clarity on goals and preferences for future health-care decisions, the timeliness of which is critical for persons with dementia. AIM: This study assessed Primary Care Collaborative Memory Clinic (PCCMC) health-care practitioners' desire for more education on ACP, capacity for and attitudes toward ACP, and current ACP practices in their regular family practice and in their PCCMC. METHODS: Primary Care Collaborative Memory Clinic health-care professionals completed a questionnaire in which they rated their interest in learning various ACP-related topics (5-point scale: not at all to very much so), attitudes toward ACP, and the importance of and perceived degree of responsibility for ACP (5-point scale: not at all to extremely). Respondents estimated ACP completion in regular family practice and PCCMC. RESULTS: Two hundred and sixty one surveys were completed. Mean knowledge ratings were moderate (M = 3.0) and mean ratings of interest in ACP topics were all high (median ≥ 4). Despite the perception that ACP is very important (M = 4.9) and the responsibility of PCCMCs (M = 3.7), the majority of respondents estimated that 40% or fewer patients have had ACP. Ratings of willingness to conduct ACP (M = 3.7) and comfort level (M = 3.4) were moderate but significantly exceeded ratings of ability (M = 2.9), comfort (M = 3.5), and confidence (M = 2.8). CONCLUSION: There was a striking disconnect between perceptions of the importance of completing ACP for persons with dementia and actual ACP completion rates. Primary Care Collaborative Memory Clinics may be in an ideal position to support ACP discussions; however, there is a need to improve health-care professionals' knowledge and attitudes toward ACP.

Ingested Micronizing Plastic Particle Compositions and Size Distributions within Stranded Post-Hatchling Sea Turtles.

From July 2015 to November 2016, 96 post-hatchling sea turtles were collected from 118 km of the Atlantic coastline in Florida, USA, including loggerhead, green, and hawksbill sea turtle species. Forty-five of the recovered turtles were rehabilitated and released, but the remaining 52 died and were frozen. At necropsy, the gastrointestinal tracts of most the turtles contained visible plastic, and collected particles of 27 individuals were chemically characterized by Raman microscopy as polyethylene, polypropylene, polyethylene terephthalate, and polystyrene. Mesoparticle plastic fragments 1.0-8.7 mm, microparticle fragments 20-1000 µm, and nanoparticles 5-169 nm were identified in the turtles. Polyethylene and polypropylene were the most common plastics ingested from specimens representing 54.1 and 23.7% of the total observed mesoparticles and 11.7 and 21.0% of the total observed microparticles, respectively. A plastic-to-body mass ratio of 2.07 mg/g was determined for this group. The authors suggest that ingestion of micronizing plastic by post-hatchling sea turtles is likely a substantial risk to survival of these endangered and threatened species. This study also provides some of the first evidence for the formation of nanoscopic plastic particles that we theorize forms in the post-hatchling and juvenile environment and are present post-ingestion.

Sialylated Receptor Setting Influences Mycoplasma pneumoniae Attachment and Gliding Motility.

Mycoplasma pneumoniae is a common cause of human respiratory tract infections, including bronchitis and atypical pneumonia. M. pneumoniae binds glycoprotein receptors having terminal sialic acid residues via the P1 adhesin protein. Here, we explored the impact of sialic acid presentation on M. pneumoniae adherence and gliding on surfaces coated with sialylated glycoproteins, or chemically functionalized with α-2,3- and α-2,6-sialyllactose ligated individually or in combination to a polymer scaffold in precisely controlled densities. In both models, gliding required a higher receptor density threshold than adherence, and receptor density influenced gliding frequency but not gliding speed. However, very high densities of α-2,3-sialyllactose actually reduced gliding frequency over peak levels observed at lower densities. Both α-2,3- and α-2,6-sialyllactose supported M. pneumoniae adherence, but gliding was only observed on the former. Finally, gliding on α-2,3-sialyllactose was inhibited on surfaces also conjugated with α-2,6-sialyllactose, suggesting that both moieties bind P1 despite the inability of the latter to support gliding. Our results indicate that the nature and density of host receptor moieties profoundly influences M. pneumoniae gliding, which could affect pathogenesis and infection outcome. Furthermore, precise functionalization of polymer scaffolds shows great promise for further analysis of sialic acid presentation and M. pneumoniae adherence and gliding.

Biodegradation of Poly(3-hydroxybutyrate- co-3-hydroxyhexanoate) Plastic under Anaerobic Sludge and Aerobic Seawater Conditions: Gas Evolution and Microbial Diversity.

Poly(3-hydroxybutyrate- co-3-hydroxyhexanoate) (poly(3HB- co-3HHx)) thermoplastics are a promising biodegradable alternative to traditional plastics for many consumer applications. Biodegradation measured by gaseous carbon loss of several types of poly(3HB- co-3HHx) plastic was investigated under anaerobic conditions and aerobic seawater environments. Under anaerobic conditions, the biodegradation levels of a manufactured sheet of poly(3HB- co-3HHx) and cellulose powder were not significantly different from one another over 85 days with 77.1 ± 6.1 and 62.9 ± 19.7% of the carbon converted to gas, respectively. However, the sheet of poly(3HB- co-3HHx) had significantly higher methane yield ( p ≤ 0.05), 483.8 ± 35.2 mL·g-1 volatile solid (VS), compared to cellulose controls, 290.1 ± 92.7 mL·g-1 VS, which is attributed to a greater total carbon content. Under aerobic seawater conditions (148-195 days at room temperature), poly(3HB- co-3HHx) sheets were statistically similar to cellulose for biodegradation as gaseous carbon loss (up to 83% loss in about 6 months), although the degradation rate was lower than that for cellulose. The microbial diversity was investigated in both experiments to explore the dominant bacteria associated with biodegradation of poly(3HB- co-3HHx) plastic. For poly(3HB- co-3HHx) treatments, Cloacamonales and Thermotogales were enriched under anaerobic sludge conditions, while Clostridiales, Gemmatales, Phycisphaerales, and Chlamydiales were the most enriched under aerobic seawater conditions.

Frailty Screening and Case-Finding for Complex Chronic Conditions in Older Adults in Primary Care.

With the aging population, escalating demand for seniors' care and limited specialist resources, new care delivery models are needed to improve capacity for primary health care for older adults. This paper describes the "C5-75" (Case-finding for Complex Chronic Conditions in Seniors 75+) program, an innovative care model aimed at identifying frailty and commonly associated geriatric conditions among older adults within a Canadian family practice setting and targeting interventions for identified conditions using a feasible, systematic, evidence-informed multi-disciplinary approach. We screen annually for frailty using gait speed and handgrip strength, screen for previously undiagnosed comorbid conditions, and offer frail older adults multi-faceted interventions that identify and address unrecognized medical and psychosocial needs. To date, we have assessed 965 older adults through this program; 14% were identified as frail based on gait speed alone, and 5% identified as frail based on gait speed with grip strength. The C5-75 program aims to re-conceptualize care from reactive interventions post-diagnosis for single disease states to a more proactive approach aimed at identifying older adults who are at highest risk of poor health outcomes, case-finding for unrecognized co-existing conditions, and targeting interventions to maintain health and well-being and potentially reduce vulnerability and health destabilization.