In this series, the most common risk factor for keratitis was contact lens wear and the most commonly isolated organism was P. aeruginosa.

An outcome of poor vision, vision loss during treatment, surgical intervention or complication of keratitis is more likely in patients with severe keratitis, keratitis related to prior ocular surface disease or older age.

In this series, keratitis related to contact lens wear became more frequent, whereas keratitis related to prior ocular surgery became less frequent. Different organism groups showed significant seasonal variations in their presentation, and bacterial resistance to cephalothin increased significantly.

AimsTo estimate the incidence of culture-positive microbial keratitis in Queensland and analyse trends in the organisms and their sensitivities cultured from corneal scrapes, especially low-incidence organisms.MethodsRetrospective multicentre case series of all positive corneal scrapes in Queensland, Australia between 2005 and 2015. Pathology organisations in Queensland were identified by online and local directory search and agreed to participate. Digital records of scrapes provided patient demographics and culture and susceptibility results. Trends in the incidence, organisms and sensitivities were monitored with linear regression. The yearly incidence of microbial keratitis was estimated from the Queensland population.ResultsThe included corneal scrapes totalled 3182, while 1006 were excluded. The included scrapes yielded 4111 organisms. Pseudomonas aeruginosa was the most common single isolate (729, 17.7%), although Gram-positive organisms were more common overall (2737, 66.6%). Fungal organisms were cultured in 6% of cases, while Acanthamoeba comprised only 1% of records. Bacterial organisms were sensitive to all recorded antibiotics in 89% of all isolates and none of the reported antibiotics showed a decreasing trend in susceptibility. The incidence of protozoal isolation decreased over time (p=0.055). Cultures positive for yeasts showed a linear increase in incidence (p=0.045) while moulds showed a spike in incidence in 2010–2012 (p=0.0008).ConclusionThe estimated incidence of microbial keratitis was 0.66 cases per 10 000 people, the rate of antibiotic susceptibility is high and stable, the incidence of keratitis secondary to protozoa is likely to be decreasing while the incidence of keratitis culturing yeast is increasing.

Importance Contact lens microbial keratitis (CLMK) is the most common cause of microbial keratitis in our community. Background Define the trend in rate of CLMK and define patient demographics/culture results that may have a predictive value in patients with CLMK. Design Retrospective review of clinical records of patients with MK. Participants All patients with positive corneal scraping between 1999 and 2015 at the Princess Alexandra Hospital, Brisbane, Queensland identified through local microbiology database. Methods Trend in CLMK tested with chi‐squared test of peak 3 years vs other years and Poisson regression of interrupted time series. Patient characteristics predictive of CLMK were defined by creating a polynomial regression model by stepwise variable selection. Main Outcome Measures Yearly rate of CLMK. Results Records of 895 episodes of MK were included. The most common: risk factor was contact lens wear (324, 36.2%), isolated organism was Pseudomonas aeruginosa (P. aeruginosa 181, 55.9%) and treatment was monotherapy with a fluoroquinolone 172, 53%). CLMK was most common between 2009 and 2011 (49.5% vs other years 32%, P < 0.001). Poisson regression of the interrupted time series showed there was a significant decrease in the rate over time after 2010 (P < 0.001). Independent factors predictive of CLMK in multivariate regression were young age (15‐49 years) and corneal culture positive for P. aeruginosa Conclusions and Relevance The rate of CLMK in our community ranged between 32% and 50% and the rate of disease appears to have peaked during 2009 to 2011 and subsequently declined.

Alloying in semiconductors has enabled many civilian technologies in electronics, optoelectronics, photonics, and others. While the alloying phenomenon is well established in traditional bulk semiconductors owing to a vast array of available ternary phase diagrams, alloying in 2D materials still remains at its seminal stages. This is especially true for transition metal trichalcogenides (TMTCs) such as TiS3 which has been recently predicted to be a direct gap, high carrier mobility, pseudo-1D semiconductor. In this work, we report on an unusual alloying rejection behavior in TiS3(1-x)Se3x vdW crystals. TEM, SEM, EDS, and angle-resolved Raman measurements show that only a miniscule amount (8%) of selenium can be successfully alloyed into a TiS3 host matrix despite vastly different precursor amounts as well as growth temperatures. This unusual behavior contrasts with other vdW systems such as TiS2(1-x)Se2x, MoS2(1-x)Se2x, Mo1-xWxS2, WS2(1-x)Se2x, where continuous alloying can be attained. Angle-resolved Raman and kelvin probe force microscopy measurements offer insights into how selenium alloying influences in-plane structural anisotropy as well as electron affinity values of exfoliated sheets. Our cluster expansion theory calculations show that only the alloys with a small amount of Se can be attained due to energetic instability above/below a certain selenium concentration threshold in the ternary phase diagrams. The overall findings highlight potential challenges in achieving stable Ti based TMTCs alloys.

Amphiphilic silicone copolymers are an exciting class of biomedically relevant polymers that can be used for magnetic resonance imaging (MRI)-based cell labeling and oximetry studies. However, the solution characteristics and the ability to form stable nanoemulsions must be first demonstrated. Therefore, a series of amphiphilic siloxanes were successfully synthesized by grafting allylic poly(ethylene glycol) (PEG) with three (PEG(3)) or 11 (PEG( 11)) repeat units or allylic triethylammonium bromide (QUAT) substituents onto polyhydromethylsiloxane backbones at three different PEG:ammonium molar ratios by using a one-pot reaction pathway. The PEG length and the PEG:QUAT molar ratio were varied to tune the hydrophilicity and surface tension, and the polymer structures were confirmed by using 1 H NMR and FT-IR spectroscopy. The results show that the water contact angle increased upon attaching the PEG and QUAT groups, while the surface tension was most sensitive to the PEG(3) concentration. Also, the critical micelle concentration of the silicone graft copolymers decreased with an increase in the PEG content. Dynamic light scattering (DLS) and cryogenic transmission electron microscopy probed the solution structures and the ability to form nanoemulsions encapsulating polydimethylsiloxane (PDMS) oils. The graft copolymers containing PEG(3) showed consistent sizes by DLS, but the size distribution changed for the PEG(11) samples as the QUAT concentration increased. Finally, the graft copolymers successfully formed stable nanoemulsions containing PDMS with particle sizes that are appropriate for MRI-based cell labeling and oximetry applications.

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