Tuning the rheology and microstructure of particle-laden fluid interfaces with Janus particles.

Hypothesis: Particle-laden fluid interfaces are the central component of many natural and engineering systems. Understanding the mechanical properties and improving the stability of such interfaces are of great practical importance. Janus particles, a special class of heterogeneous colloids, might be used as an effective surface-active agent to control the assembly and interfacial rheology of particle-laden fluid interfaces.

Transport Evidence for Sulfur Vacancies as the Origin of Unintentional n-Type Doping in Pyrite FeS.

Pyrite FeS has long been considered a potential earth-abundant low-cost photovoltaic material for thin-film solar cells but has been plagued by low power conversion efficiencies and open-circuit voltages. Recent efforts have identified a lack of understanding and control of doping, as well as uncontrolled surface conduction, as key roadblocks to the development of pyrite photovoltaics. In particular, while n-type bulk behavior in unintentionally doped single crystals and thin films is speculated to arise from sulfur vacancies (V), proof remains elusive.

Superlattice-based thin-film thermoelectric modules with high cooling fluxes.

In present-day high-performance electronic components, the generated heat loads result in unacceptably high junction temperatures and reduced component lifetimes. Thermoelectric modules can, in principle, enhance heat removal and reduce the temperatures of such electronic devices. However, state-of-the-art bulk thermoelectric modules have a maximum cooling flux qmax of only about 10 W cm(-2), while state-of-the art commercial thin-film modules have a qmax <100 W cm(-2).

Non-contact method for characterization of small size thermoelectric modules.

Conventional techniques for characterization of thermoelectric performance require bringing measurement equipment into direct contact with the thermoelectric device, which is increasingly error prone as device size decreases. Therefore, the novel work presented here describes a non-contact technique, capable of accurately measuring the maximum ΔT and maximum heat pumping of mini to micro sized thin film thermoelectric coolers. The non-contact characterization method eliminates the measurement errors associated with using thermocouples and traditional heat flux sensors to test small samples and large heat fluxes.

A Thermally Conductive Separator for Stable Li Metal Anodes.

Li metal anodes have attracted considerable research interest due to their low redox potential (-3.04 V vs standard hydrogen electrode) and high theoretical gravimetric capacity of 3861 mAh/g. Battery technologies using Li metal anodes have shown much higher energy density than current Li-ion batteries (LIBs) such as Li-O2 and Li-S systems.

Phase Stability and Stoichiometry in Thin Film Iron Pyrite: Impact on Electronic Transport Properties.

The use of pyrite FeS2 as an earth-abundant, low-cost, nontoxic thin film photovoltaic hinges on improved understanding and control of certain physical and chemical properties. Phase stability, phase purity, stoichiometry, and defects, are central in this respect, as they are frequently implicated in poor solar cell performance. Here, phase-pure polycrystalline pyrite FeS2 films, synthesized by ex situ sulfidation, are subject to systematic reduction by vacuum annealing (to 550 °C) to assess phase stability, stoichiometry evolution, and their impact on transport.

Hepatitis C virus seroconversion among HIV-positive men who have sex with men with no history of injection drug use: Results from a clinical HIV cohort.

Background: Internationally, there is a growing recognition that hepatitis C virus (HCV) may be sexually transmitted among HIV-positive men who have sex with men (MSM).

Objective: To report the first Canadian estimate of HCV seroincidence in 2000 to 2010 and its risk factors among HIV-positive MSM with no known history of injection drug use.

Methods: Data from the Ontario HIV Treatment Network Cohort Study, an ongoing cohort of individuals in HIV care in Ontario, were analyzed.

Impact of a chronic disease self-management program on health care utilization in rural communities: a retrospective cohort study using linked administrative data.

Background: Internationally, chronic disease self-management programs (CDSMPs) have been widely promoted with the assumption that confident, knowledgeable patients practicing self-management behavior will experience improved health and utilize fewer healthcare resources. However, there is a paucity of published data supporting this claim and the majority of the evidence is based on self-report.

Methods: We used a retrospective cohort study using linked administrative health data.

Effect of a course-based intervention and effect of medical regulation on physicians' opioid prescribing.

Objective: To examine the effects of an intensive 2-day course on physicians' prescribing of opioids.

Design: Population-based retrospective observational study.

Setting: College of Physicians and Surgeons of Ontario (CPSO) in Toronto.

Crossover from nanoscopic intergranular hopping to conventional charge transport in pyrite thin films.

Pyrite FeS2 is receiving a resurgence of interest as a uniquely attractive thin film solar absorber based on abundant, low-cost, nontoxic elements. Here we address, via ex situ sulfidation synthesis, the long-standing problem of understanding conduction and doping in FeS2 films, an elusive prerequisite to successful solar cells. We find that an abrupt improvement in crystallinity at intermediate sulfidation temperatures is accompanied by unanticipated crossovers from intergranular hopping to conventional transport, and, remarkably, from hole-like to electron-like Hall coefficients.

Multiple sclerosis disease-modifying therapy prescribing patterns in Ontario.

Background: Differences in Multiple sclerosis (MS) disease-modifying therapy (DMT) prescribing patterns between different groups of neurologists have not been explored.

Objective: To examine concentrations of prescribing patterns and to assess if MS-specialists use a broader range of DMTs relative to general neurologists.

Methods: We conducted a cross-sectional study using administrative claims databases in Ontario, Canada to link neurologists to 2009 DMT prescription data.

Hopping transport and the Hall effect near the insulator-metal transition in electrochemically gated poly(3-hexylthiophene) transistors.

Despite 35 years of investigation, much remains to be understood regarding charge transport in semiconducting polymers, including the ultimate limits on their conductivity. Recently developed ion gel gating techniques provide a unique opportunity to study such issues at very high charge carrier density. Here we have probed the benchmark polymer semiconductor poly(3-hexylthiophene) at electrochemically induced three-dimensional hole densities approaching 10(21) cm(-3) (up to 0.

Resonant photoemission and spin polarization of Co(1-x)Fe(x)S(2).

The valence band occupied state electronic structure of Co(1-x)Fe(x)S(2) in the region of the Fe/Co 3d bands has been investigated using photoemission and spin-polarized photoemission. As measured by using spin-polarized ultraviolet photoemission, the surface Fermi level spin polarization of Co(1-x)Fe(x)S(2) thin films at 50 K, specifically at x = 0, 0.05, 0.

Fluoroquinolone therapy and idiosyncratic acute liver injury: a population-based study.

Background: Although fluoroquinolones are sometimes associated with mild, transient elevations in aminotransferase levels, serious acute liver injury is uncommon. Regulatory warnings have identified moxifloxacin as presenting a particular risk of hepatotoxicity. Thus, we examined the risk of idiosyncratic acute liver injury associated with the use of moxifloxacin relative to other selected antibiotic agents.

Single-crystalline silver films for plasmonics.

A simple route to flat, large-area, single-crystalline films for plasmonics is demonstrated by sputter deposition of silver onto mica substrates at elevated temperatures. The films exhibit improved dielectric properties and allow more precise patterning of high-quality nanostructures for plasmonic applications.

New fibrate use and acute renal outcomes in elderly adults: a population-based study.

Background: Fibric acid derivatives (fibrates) have been shown to increase serum creatinine level in randomized trials.

Objective: To assess renal outcomes in elderly adults within 90 days of a new fibrate prescription.

Design: Population-based cohort study.

Antidepressants, metoprolol and the risk of bradycardia.

Case reports and pharmacologic theory suggest that some antidepressants can interfere with the hepatic metabolism of metoprolol by cytochrome P450 2D6 (CYP2D6), potentially increasing the risk of bradycardia. The objective of this study was to characterize the clinical consequences of this potential drug interaction at the population level. We conducted a population-based, nested case-control study of Ontario residents 66 years of age or older receiving metoprolol.

Beta-blockers and cardiovascular outcomes in dialysis patients: a cohort study in Ontario, Canada.

Background: Beta-blockers may be cardioprotective in patients receiving chronic dialysis. We examined cardiovascular outcomes among incident dialysis patients receiving beta-blocker therapy.

Methods: We conducted a retrospective cohort study employing linked healthcare databases in Ontario, Canada.

Adherence to multiple sclerosis disease-modifying therapies in Ontario is low.

Background/objective: Differences in patient adherence to various disease-modifying drugs (DMDs) in the treatment of multiple sclerosis (MS) are not well understood. The goal of this study was to evaluate adherence of adult MS patients in Ontario with public drug plan coverage to various DMDs: intramuscular interferon beta-1a (i.m.

Reduction in diisocyanate and non-diisocyanate sensitizer-induced occupational asthma in Ontario.

Objective: To investigate relative frequency and features of diisocyanate (ISO) and non-diisocyanate (N-ISO) allowed occupational asthma (OA) claims in Ontario, Canada, during a 5-year period (1998 to 2002).

Methods: Records were abstracted from the Ontario Workplace Safety and Insurance Board using methodology similar to our previous investigation that had identified 30 ISO and 30 N-ISO claims/yr during 1980 to 1993.

Results: There were 99 OA claims: 37 ISO (7.

Work-related asthma in health care in Ontario.

Background: The health of workers in health care has been neglected in the past. There are few reports regarding occupational asthma (OA) in this group, and work-exacerbated asthma (WEA) has rarely been considered.

Methods: We examined the frequency of claims for OA and WEA allowed by the compensation board in Ontario, Canada for which industry was coded as "health care" between 1998 and 2002, to determine the frequency of OA and WEA, causative agents, and occupations.

Promoter methylation of Wnt antagonists DKK1 and SFRP1 is associated with opposing tumor subtypes in two large populations of colorectal cancer patients.

Aberrant activation of canonical Wnt signaling is a hallmark event in colorectal carcinogenesis. The Dickkopf-1 (DKK1) and Secreted Frizzled Related Protein 1 (SFRP1) genes encode extracellular inhibitors of Wnt signaling that are frequently silenced by promoter hypermethylation in colorectal cancer (CRC). These methylation events have been identified as prognostic markers of patient outcome and tumor subtype in several cancers but similar roles in CRC have not been comprehensively examined.