Risk Factors for Trabeculotomy Failure in Primary Congenital Glaucoma

Précis: This study demonstrates that a baseline corneal diameter >12.25, initial age [removed]12.25 mm did by 4.2 times, younger age than 4 months did by 2.5 times, bilaterality did by 1.5 times. Conclusions: A higher baseline IOP, younger age, larger corneal diameter, and bilaterality were identified as risk factors for trabeculotomy failure in congenital glaucoma. The presence of one or more of these should be considered in the decision-making process when considering surgical options to manage glaucoma in these patients. © 2022 Wolters Kluwer Health, Inc. All rights reserved

Study on weathering behavior of jack pine heat-treated under different conditions

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.It is of considerable importance to investigate the influence of weathering on the degradation processes of heat-treated wood. Kiln-dried (untreated) jack pine (Pinus banksiana) and jack pine heat-treated at three different temperatures (190°C, 200°C, and 210°C) were exposed to artificial weathering for different periods in order to understand the degradation processes due to weathering. Before and after exposure, their color and wettability by water were determined. Structural changes and chemical modifications at exposed surfaces were also investigated using SEM, FTIR spectroscopy, and XPS. The results revealed that the photo-degradation of lignin and the presence of extractives play important roles in color change and wetting behavior of heat-treated wood surfaces during weathering. The structural changes also influence the wettability. The effects of weathering for woods heat-treated under different conditions were similar, but different from those for untreated wood.dc201

Determination of the size distribution of non-spherical nanoparticles by electric birefringence-based methods

The in situ determination of the size distribution of dispersed non-spherical nanoparticles is an essential characterization tool for the investigation and use of colloidal suspensions. In this work, we test a size characterization method based on the measurement of the transient behaviour of the birefringence induced in the dispersions by pulsed electric fields. The specific shape of such relaxations depends on the distribution of the rotational diffusion coefficient of the suspended particles. We analyse the measured transient birefringence with three approaches: the stretched-exponential, Watson-Jennings, and multiexponential methods. These are applied to six different types of rod-like and planar particles: PTFE rods, goethite needles, single- and double-walled carbon nanotubes, sodium montmorillonite particles and gibbsite platelets. The results are compared to electron microscopy and dynamic light scattering measurements. The methods here considered provide good or excellent results in all cases, proving that the analysis of the transient birefringence is a powerful tool to obtain complete size distributions of non-spherical particles in suspension.Financial support of this investigation by Junta de Andalucía, Spain (grant No. PE2012-FQM0694) and University of Granada (Program “Proyectos de investigación precompetitivos”) is gratefully acknowledged

Investigation of the scaling law on gelation of oppositely charged nanocrystalline cellulose and polyelectrolyte

The sol-gel transition in the mixture system of oppositely charged polyelectrolyte (quaternized hydroxyethylcellulose ethoxylate, QHEC) and nanocrystalline cellulose (NCC) induced by electrostatic adsorption interaction was investigated by rheological means. Winter and Chambon theory was validated to be applicable for the critical gel point determination, and critical gel point have been successfully determined. With QHEC concentration increasing, more NCC were needed to form a critical gel, and smaller loss tangent and relaxation exponent (n) values at the gel point were observed, indicating the elastic nature of mixture was enhanced with QHEC increase. Gel strength behaved as a function of both QHEC and NCC concentrations, suggesting the gel network at the critical point was composed of entanglements and association of QHEC macromolecular chains, as well as the electrostatic adsorption interaction between QHEC chains and NCC rods. The calculated number of NCC rods per junction decreased from 0.30 to 0.01 when the QHEC concentration increased from 1.0 wt% to 3.0 wt%, indicating the electrostatic adsorption interaction between the NCC rods and QHEC chains was less significant to gel formation at higher QHEC concentrations. Therefore, the exponents of scaling law \u3b70 1d 08-\u3b3 and Ge 1d 08z for the QHEC/NCC mixtures revealed that the scaling law n = z/(z + \u3b3) between n, \u3b3, and z was only feasible at highest QHEC concentration, since the intermolecular interaction (electrostatic adsorption interaction in this article) was so weak that can be neglected and the critical gel network was dominated by QHEC chain entanglements and association. \ua9 2014 Elsevier Ltd.Peer reviewed: YesNRC publication: Ye

Analysis of cellulose nanocrystal rod lengths by dynamic light scattering and electron microscopy

A method to characterize the length (L) of rod-like cellulose nanocrystal (CNC) particles is described. It is based on dynamic light scattering (DLS) and electron microscopy. Measurement of translational diffusion coefficient from DLS along with diameter measurements from electron microscopy is used in Broersma translational diffusion coefficient equation to calculate the CNC particle L. For wood based CNC rods, diameter of 15 nm measured by scanning electron microscopy (SEM) and translational diffusion coefficient of 5.21 7 10 -12 m2/s measured by DLS give particle L of 271 nm from Broersma's relation. This one and other calculated L values for various rod-like particles are in good agreement with the L of the particles measured either by transmission or SEM. \ua9 2013 Springer Science+Business Media Dordrecht.Peer reviewed: YesNRC publication: Ye

Nanocomposites of nanocrystalline cellulose for enzyme immobilization

We describe the synthesis, characterization and use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. Nanocrystalline cellulose (NCC) is a product isolated from natural cellulose fibers, which is of approximately 100 nm long and 10 nm wide in size. We augmented the surface area and tailored the chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNPs). The deposition of AuNPs on NCC was controlled by using cationic polyethylenimine (PEI) at different pHs. AuNPs were thiol-functionalized using different linkers prior to enzyme immobilization. The enzyme (glucose oxidase or GOx) was conjugated on the composite by carbodiimide coupling, and subsequent activation of linker-carboxylic acid group. Our results showed that GOx was attached to the surface of the NCC nanocomposite. Moreover, the amount of GOx loaded onto the support depended on the length of the thiol-linker used. The lower value (20. 3 mg/mg of support) was obtained with the longer thiol-linker (11 carbon chain) compared to 25. 2 mg/mg of support for the smaller thiol-linker (3 carbon chain). \ua9 2012 Springer Science+Business Media Dordrecht.Peer reviewed: YesNRC publication: Ye

Amine-decorated nanocrystalline cellulose surfaces: Synthesis, characterization, and surface properties

In this present work, terminal amino-functionalized nanocrystalline cellulose derivatives were prepared using a simple two-step protecting group-free protocol under aqueous reaction conditions at room temperature. Carboxylate groups were first introduced onto the surface of nanocrystalline cellulose (NCC) via a TEMPO-mediated oxidation. Then, reaction of surface-carboxylated NCC with bifunctional amines of small alkyl chain length by EDC/NHS-mediated coupling furnished the desired aminated NCC via an amide linkage. Surface covalent functionalization was confirmed by Fourier transform infrared spectroscopy, elemental analysis, and X-ray photoelectron spectroscopy. Size, surface charge, morphology, and thermal properties were obtained by various techniques. STEM images revealed no change in structure and morphology of the materials after TEMPO-mediated oxidation but a slight agglomeration was observed after surface covalent functionalization with diamines. While amide linkage confers stability, terminal primary amine groups on the surface of NCC represent a versatile reactive functional group for bioconjugation with other biomolecules for potential biomedical applications. \ua9 2013 Published by NRC Research Press.Peer reviewed: YesNRC publication: Ye

Surface modification and dispersion of nanocrystalline cellulose in organic media

Peer reviewed: YesNRC publication: Ye

Flocculation of cellulose nanocrystals by adsorbing and non-adsorbing polymers

Peer reviewed: YesNRC publication: Ye

Nanocomposites of nanocrystalline cellulose for biosensor applications

In this work, we describe the use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. NCC is a product isolated from natural cellulose fibers, which is of approx. 100 nm long and 10 nm wide in size. We augmented the surface area and chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNP). The deposition of AuNP on NCC was controlled by using cationic Polyethylenimine (PEI). AuNPs were thio-funtionalized prior to enzyme immobilization and the enzyme (glucose oxidase) was conjugated on the composite by carbodiimide (EDC)/NHS coupling. Using UV-visible and fluorescence spectroscopy in the presence of a specific substrate we monitored the activity of the immobilized enzymes, and its efficiency was compared with that of the enzyme in free form. Our results using FT-IR and SEM show that thiol-AuNPs were attached to the surface of NCC. The enzymes activity were measured and quantified using different kit assays and proved that the enzymes were attached to the support and maintained their activity.Peer reviewed: YesNRC publication: Ye