Highly CO2 sensitive extruded fluorescent plastic indicator film based on HPTS

Highly-sensitive optical fluorescent extruded plastic films are reported for the detection of gaseous and dissolved CO2. The pH-sensitive fluorescent dye used is 8-Hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS, PTS-) coated on the surface of hydrophilic fumed silica and the base is tetrabutylammonium hydroxide (TBAH). The above components are used to create an HPTS pigment (i.e. HPTS/SiO2/TBAH) with a high CO2 sensitivity (%CO2(S=1/2) = 0.16%) and fast 50% response (t50↓) = 2 s and recovery (t50↑) = 5 s times. Highly CO2-sensitive plastic films are then fabricated, via the extrusion of the HPTS pigment powder in low-density polyethylene (LDPE). As with the HPTS-pigment, the luminescence intensity (at 515 nm) and absorbance (at 475 nm) of the HPTS plastic film decreases as the %CO2 in the ambient gas phase increases. The HPTS plastic film exhibits a high CO2 sensitivity, %CO2(S=1/2), of 0.29%, but a response time ˂2 min and recovery time ˂40 min, which is slower than that of the HPTS pigment. The HPTS plastic film is very stable under ambient conditions, (with a shelf life ˃ six month when stored in the dark but under otherwise ambient conditions). Moreover, the HPTS-film is stable in water, salt solution and even in acid (pH=2), and in each of these media it can be used to detect dissolved CO2.

Protocol-driven adjustment of ocular hypotensive medication in patients at low risk of conversion to glaucoma

AIM: To investigate the safety and potential savings of decreasing medication use in low-risk patients with ocular hypertension (OH).
METHODS: Patients with OH receiving pressure-lowering medication identified by medical record review at a university hospital underwent examination by a glaucoma specialist with assessment of visual field (VF), vertical cup-to-disc ratio (vCDR), central corneal thickness and intraocular pressure (IOP). Subjects with estimated 5-year risk of glaucoma conversion <15% were asked to discontinue ≥1 medication, IOP was remeasured 1 month later and risk was re-evaluated at 1 year.
RESULTS: Among 212 eyes of 126 patients, 44 (20.8%) had 5-year risk >15% and 14 (6.6%) had unreliable baseline VF. At 1 month, 15 patients (29 eyes, 13.7%) defaulted follow-up or refused to discontinue medication and 11 eyes (5.2%) had risk >15%. The remaining 69 patients (107 eyes, 50.7%) successfully discontinued 141 medications and completed 1-year follow-up. Mean IOP (20.5±2.65 mm Hg vs 20.3±3.40, p=0.397) did not change, though mean VF pattern SD (1.58±0.41 dB vs 1.75±0.56 dB, p=0.001) and glaucoma conversion risk (7.31±3.74% vs 8.76±6.28%, p=0.001) increased at 1 year. Mean defect decreased (-1.42±1.60 vs -1.07±1.52, p=0.022). One eye (0.47%) developed a repeatable VF defect and 13 eyes (6.1%) had 5-year risk >15% at 1 year. The total 1-year cost of medications saved was US$4596.
CONCLUSIONS: Nearly half (43.9%) of low-risk OH eyes in this setting could safely reduce medications over 1 year, realising substantial savings.Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Ectopic bone formation in rapidly fabricated acellular injectable dense collagen-Bioglass hybrid scaffolds via gel aspiration-ejection

Gel aspiration-ejection (GAE) has recently been introduced as an effective technique for the rapid production of injectable dense collagen (IDC) gel scaffolds with tunable collagen fibrillar densities (CFDs) and microstructures. Herein, a GAE system was applied for the advanced production and delivery of IDC and IDC-Bioglass® (IDC-BG) hybrid gel scaffolds for potential bone tissue engineering applications. The efficacy of GAE in generating mineralizable IDC-BG gels (from an initial 75-25 collagen-BG ratio) produced through needle gauge numbers 8G (3.4 mm diameter and 6 wt% CFD) and 14G (1.6 mm diameter and 14 wt% CFD) was investigated. Second harmonic generation (SHG) imaging of as-made gels revealed an increase in collagen fibril alignment with needle gauge number. In vitro mineralization of IDC-BG gels was confirmed where carbonated hydroxyapatite was detected as early as day 1 in simulated body fluid, which progressively increased up to day 14. In vivo mineralization of, and host response to, acellular IDC and IDC-BG gel scaffolds were further investigated following subcutaneous injection in adult rats. Mineralization, neovascularization and cell infiltration into the scaffolds was enhanced by the addition of BG and at day 21 post injection, there was evidence of remodelling of granulation tissue into woven bone-like tissue in IDC-BG. SHG imaging of explanted scaffolds indicated collagen fibril remodelling through cell infiltration and mineralization over time. In sum, the results suggest that IDC-BG hybrid gels have osteoinductive properties and potentially offer a novel therapeutic approach for procedures requiring the injectable delivery of a malleable and dynamic bone graft that mineralizes under physiological conditions

Evidence for the reliability and validity, but not the practical utility of the two-factor Consideration of Future Consequences Scale-14

Researchers have proposed 1-factor, 2-factor, and bifactor solutions to the 12-item Consideration of Future Consequences Scale (CFCS-12). In order to overcome some measurement problems and to create a robust and conceptually useful two-factor scale the CFCS-12 was recently modified to include two new items and to become the CFCS-14. Using a University sample, we tested four competing models for the CFCS-14: (a) a 12-item unidimensional model, (b) a model fitted for two uncorrelated factors (CFC-Immediate and CFC-Future), (c) a model fitted for two correlated factors (CFC-I and CFC-F), and (d) a bifactor model. Results suggested that the addition of the two new items has strengthened the viability of a two factor solution of the CFCS-14. Results of linear regression models suggest that the CFC-F factor is redundant. Further studies using alcohol and mental health indicators are required to test this redundancy.