Magnetic sulfur-doped carbons for mercury adsorption.

Mercury pollution is a significant threat to the environment and health worldwide. Therefore, effective and low-cost absorbents that are easily scalable are needed for real-world applications. Enlarging the surface area of the materials and doping with heteroatoms are two of the most common strategies to cope with this problem. Sulfur-doped activated carbon synthesized from the carbonization of inverse vulcanized thiopolymers makes it possible to combine both large specific surface area and doping of heteroatoms, resulting in outperformance in mercury uptake against commercial activated carbons. Convenient recovery of mercury absorbents after treatment should be beneficial in mercury collecting and recycling. Therefore, magnetic sulfur-doped carbons (MSCs) were prepared by functionalizing sulfur doped carbons through chemical precipitation with magnetic iron oxides. Besides the characterisations of materials, mercury uptake experiments, such as stactic test, capacity test, impact of solution pH, and mixed ions interferences were performed. These MSCs exhibit high specific surface area (1,329 m2/g), high sulfur content (up to 14.8 wt%), porous structure, low cost, and are convenient for retrieval. MSCs are demonstrated high uptake capacity (187 mg g-1) and efficiency in mercury solution and multifunctional absorption in mixed ions solution, showing their potential to be applied in water purification and environmental remediation.

Automated label flows for excited states of correlation functions in lattice gauge theory.

Extracting excited states from lattice gauge theory correlation functions can be achieved through χ^{2} minimization fits or algebraic approaches such as the variational method and Prony's method. Performing any kind of error analysis often leads to overlapping confidence regions of model parameters, even when the spectrum is not particularly dense. To correctly estimate errors, one must beware of mislabeling the states. In this work, we provide an algorithm that we call automated label flows which consistently and systematically identifies a deterministic labeling of states. This is a black-box approach in the sense that it gives a sensible set of labels without user guidance. As an example, we pair one black box method with another, analyzing a lattice correlation function from real data using automated label flows in the context of Prony's method.

Nitric Oxide Releasing Titanium Surfaces for Antimicrobial Bone-Integrating Orthopedic Implants.

Titanium implants in orthopedic applications can fail due to infection and impaired integration into the host. Most research efforts that facilitate osseointegration of the implant have not considered infection, and vice versa. Moreover, most infection control measures involve the use of conventional antibiotics which contributes to the global epidemic of antimicrobial resistance. Nitric oxide (NO) is a promising alternative to antibiotics, and while researchers have investigated NO releasing coatings, there are few reports on the function/robustness or the mechanism of NO release. Our comprehensive mechanistic study has allowed us to design, characterize, and optimize NO releasing coatings to achieve maximum antimicrobial efficacy toward bacteria with minimum cytotoxicity to human primary osteoblasts in vitro. As the antibiotic era is coming to an end and the future of infection control continues to demand new alternatives, the coatings described herein represent a promising therapeutic strategy for use in orthopedic surgeries.

Investigating the Antibacterial Properties of Inverse Vulcanized Sulfur Polymers.

More than 60 million tons of sulfur are produced as a byproduct of the petrochemical industry annually. Recently, the inverse vulcanization process has transformed this excess sulfur into functional polymers by stabilization with organic cross-linkers. These interesting new polymers have many potential applications covering diverse areas. However, there has been very little focus on the potential of these high-sulfur polymers for their antibacterial properties. These properties are examined here by exposing two common bacteria species, Escherichia coli (E. Coli) and Staphylococcus aureus (S. aureus), to two structurally different, inverse vulcanized sulfur polymers: sulfur-co-diisopropenyl benzene (S-DIB) and sulfur dicyclopentadiene (S-DCPD). We report the highest bacteria log reduction (>log 4.3) of adhered bacterial cells (S. aureus) to an inverse vulcanized sulfur polymer to date and investigate the potential pathways in which antibacterial activity may occur.

Effect of Polymer Demixed Nanotopographies on Bacterial Adhesion and Biofilm Formation.

As the current global threat of antimicrobial resistance (AMR) persists, developing alternatives to antibiotics that are less susceptible to resistance is becoming an urgent necessity. Recent advances in biomaterials have allowed for the development and fabrication of materials with discrete surface nanotopographies that can deter bacteria from adhering to their surface. Using binary polymer blends of polystyrene (PS), poly(methyl methacrylate) (PMMA) and polycaprolactone (PCL) and varying their relative concentrations, PS/PCL, PS/PMMA and PCL/PMMA polymer demixed thin films were developed with nanoisland, nanoribbon and nanopit topographies. In the PS/PCL system, PS segregates to the air-polymer interface, with the lower solubility PCL preferring the substrate-polymer interface. In the PS/PMMA and PCL/PMMA systems, PMMA prefers the air-polymer interface due to its greater solubility and lower surface energy. The anti-adhesion efficacy of the demixed films were tested against Pseudomonas aeruginosa (PA14). PS/PCL and PCL/PMMA demixed films showed a significant reduction in cell counts adhered on their surfaces compared to pure polymer control films, while no reduction was observed in the counts adhered on PS/PMMA demixed films. While the specific morphology did not affect the adhesion, a relationship between bacterial cell and topographical surface feature size was apparent. If the surface feature was smaller than the cell, then an anti-adhesion effect was observed; if the surface feature was larger than the cell, then the bacteria preferred to adhere.

Nitric Oxide Releasing Polymeric Coatings for the Prevention of Biofilm Formation.

The ability of nitric oxide (NO)-releasing polymer coatings to prevent biofilm formation is described. NO-releasing coatings on (poly(ethylene terephthalate) (PET) and silicone elastomer (SE)) were fabricated using aminosilane precursors. Pristine PET and SE were oxygen plasma treated, followed by immobilisation of two aminosilane molecules: N-(3-(trimethoxysilyl)propyl)diethylenetriamine (DET3) and N-(3-trimethoxysilyl)propyl)aniline (PTMSPA). N-diazeniumdiolate nitric oxide donors were formed at the secondary amine sites on the aminosilane molecules producing NO-releasing polymeric coatings. The NO payload and release were controlled by the aminosilane precursor, as DET3 has two secondary amine sites and PTMSPA only one. The antibacterial efficacy of these coatings was tested using a clinical isolate of Pseudomonas aeruginosa (PA14). All NO-releasing coatings in this study were shown to significantly reduce P. aeruginosa adhesion over 24 h with the efficacy being a function of the aminosilane modification and the underlying substrate. These NO-releasing polymers demonstrate the potential and utility of this facile coating technique for preventing biofilms for indwelling medical devices.

Lattice study of the conformal window in QCD-like theories.

We study the extent of the conformal window for an SU(3) gauge theory with N{f} Dirac fermions in the fundamental representation. We present lattice evidence for 12

Up quark mass in lattice QCD with three light dynamical quarks and implications for strong CP invariance.

A standing mystery in the standard model is the unnatural smallness of the strong CP violating phase. A massless up quark has long been proposed as one potential solution. A lattice calculation of the constants of the chiral Lagrangian essential for the determination of the up quark mass, 2alpha(8)-alpha(5), is presented. We find 2alpha(8)-alpha(5)=0.29+/-0.18, which corresponds to m(u)/m(d)=0.410+/-0.036. This is the first such calculation using a physical number of dynamical light quarks, N(f)=3.

How can we learn to live with rivers? The findings of the Institution of Civil Engineers Presidential Commission on flood-risk management.

In the wake of the floods of 1998 and 2000 the Government invited the Institution of Civil Engineers (ICE) to carry out a technical review of flood-risk management in England and Wales and to consider the most appropriate approaches to flood-risk management for the 21st century. The findings of this Commission are published in the ICE report Learning to live with rivers. Further information on the Commission and its work is available at www.icenet.org.uk/presidential.htm. This paper provides an introduction to the need for such a review and the scope of the Commission's work. A summary of the findings of the Commission are presented along with key recommendations for improved flood-risk management in the future.