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Chitosan-stabilised metallic Pd (CTS-Pd) and Pt (CTS-Pt) nanoparticles were synthesised and used for the hydrogenation of palm oil. With the goal of preparing hydrogenated oil with low trans fatty acid (TFA) content under ambient conditions, Fe anion was added as the secondary metallic precursor to synthesise chitosan-stabilised bimetallic Pd–Fe (CTS-Pd–Fe) and Pt–Fe (CTS-Pt–Fe) nanoparticles. The catalytic hydrogenations with newly prepared nanoparticles were performed in aqueous solution under ambient temperature and atmospheric pressure. The addition of Fe was found to improve the catalytic activity and decrease the selectivity for TFA. Hydrogenation with CTS-Pt–Fe affords the optimal results, producing 3.8% TFA at 92.1% conversion of C18:2 and no TFA was formed until the content of C18:2 was lower than 1.7%. Based on the analyses, it can be demonstrated that the preferential conversion of C18:2 to cis C18:1 and cis C18:1 to C18:0 leads to the low formation of TFA.

Erythropoietin (EPO) is a glycoprotein hormone conventionally thought to be responsible only in producing red blood cells in our body. However, with the discovery of the presence of EPO and EPO receptors in the retinal layers, the EPO seems to have physiological roles in the eye. In this review, we revisit the role of EPO in the eye. We look into the biological role of EPO in the development of the eye and the physiologic roles that it has. Apart from that, we seek to understand the mechanisms and pathways of EPO that contributes to the therapeutic and pathological conditions of the various ocular disorders such as diabetic retinopathy, retinopathy of prematurity, glaucoma, age-related macular degeneration, optic neuritis, and retinal detachment. With these understandings, we discuss the clinical applications of EPO for treatment of ocular disorders, modes of administration, EPO formulations, current clinical trials, and its future directions.

Pristine chitosan beads were modified with sulfur (S)-containing functional groups to produce thiolated chitosan beads (ETB), thereby increasing S donor ligands and crosslinks. The effect of temperature, heating time, carbon disulfide (CS2)/chitosan ratio, and pH on total S content of ETB was examined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The total S content of ETB increased with increasing CS2/chitosan ratio and decreased with decreasing pH and increasing temperature (>60 °C) and heating time (at 60 °C). Spectroscopic analyses revealed the presence of thiol (–SH)/thione, disulfide (–S–S–), and sulfonate groups in ETB. The thiolation mechanism involves decomposition of dithiocarbamate groups, thereby forming thiourea crosslinks and trithiocarbonate, resulting in –SH oxidation to produce –S–S– crosslinks. The partially formed ETB crosslinks contribute to its acid stability and are thermodynamically feasible in adsorbing Cd and Cu. The S-containing functional groups added to chitinous wastes act as sorbents for metal remediation from acidic environments. Refereed/Peer-reviewed

Ocular trauma is a topic of unresolved controversies and there are continuous controversial and debatable management strategies for open-globe injuries (OGIs). International classification of ocular trauma proposed almost 15 years ago needs to be reviewed and to be more robust in predicting the outcome in the setting of OGIs. Anterior segment trauma involves controversies related to patching for corneal abrasion, corneal laceration repair, and medical management of hyphema. Timing of cataract surgery and intraocular lens implantation in the setting of trauma is still debated worldwide. There are unresolved issues regarding the management of OGIs involving the posterior segment. Timing of vitrectomy has been and will continue to be debated by proponents of early versus delayed intervention. The use of prophylactic cryotherapy and scleral buckle is still practiced differently throughout the world. The role of intravitreal antibiotics in posterior segment trauma in the absence of infection is still debated. Similarly, the use of vitrectomy versus vitreous tap in the setting of traumatic endophthalmitis is not fully resolved. In optic neuropathy, the role of intravenous methylprednisolone versus conservative management is always debated and still there are no evidence-based guidelines about the beneficial role of pulse steroid therapy. The role of optic canal decompression in the setting of acute traumatic optic neuropathy is also not conclusive. Orbital and adnexal trauma has been shown to adversely affect the outcome of OGI patients but both lids and orbital injury are not taken as preoperative variables in international ocular trauma classification. The timing of intervention in blow-out fracture is still debated. The pediatric age group, owing to the high risk of amblyopia and intraocular inflammation as well as strong vitreoretinal adhesions, has to be managed by different principles. Although the risk of sympathetic ophthalmia is very rare, it is always one of the key debated issues while managing traumatized eyes with no light perception vision. Prospective, controlled clinical studies are not possible in the OGI setting and this article reviews pertinent data regarding these management issues and controversies, and provides recommendations for treatment based on the available published data and the authors' personal experience.

The mycelial growth kinetics, cadmium biosorption capacity and main governing biosorption mechanism of Pleurotus ostreatus (oyster mushroom) have been determined in this study. The fungus mycelium exhibits a sig- moidal (S-shaped) growth curve in which the growth rates for the lag and exponential phases are 0.1 and 0.31 g/L·day, respectively. The grown fungus is subjected to elemental, infra-red and scanning electron microscopy-energy dispersive x-ray spectroscopy analyses, while biosorption data are fitted to established adsorption isotherm models, namely, Langmuir, Freundlich and Dubinin-Radushkevich. It is strongly suggested that the main governing mechanism involved is chemi- sorption due to good fitting of biosorption data to Langmuir and Dubinin-Radushkevich models with possibility of in- volvement of both ion exchange and complexation. Data presented in the study are very useful for design of future pilot- or industrial-scale biosorption water purification systems.

Cobalt catalysts supported on a series of mesoporous SBA-15 materials isomorphically substituted with zirconium (Zr/Si atomic ratio = 1/20) with different pore sizes (5.7 nm, 7.8 nm, 11.6 nm, 17.6 nm) have been synthesized. The catalysts were characterized by transmission electron microscopy, 29Si solid state magic angle spinning (MAS) NMR, N2 adsorption-desorption measurements, X-ray powder diffraction, X-ray photoelectron spectroscopy, H2-temperature programmed reduction, H2-temperature programmed desorption and O2 titrations. The results indicated that larger pore size led to weaker interactions between cobalt and the supports which lowered the temperature of both reduction steps (Co3O4→CoO and CoO→Co0). The catalytic performances of the catalysts in Fischer-Tropsch synthesis (FTS) were tested in a fixed bed reactor. It was found that the FTS catalytic activity and product selectivity depended strongly on the pore size of the catalysts. The catalyst with a pore size of 7.8 nm showed the best FTS activity, and the catalyst with a pore size of 17.6 nm showed the highest selectivity to C12–C20 and C20+ hydrocarbons.

We investigate the properties of shear horizontal surface acoustic wave propagation in layered functionally graded piezoelectric material structures loaded with viscous liquid. The piezoelectric material is polarized in the z-direction and the material properties change gradually along the thickness of the layer. Interfacial mechanical conditions are continuity of particle velocity and stress components at the interface. We here assume that the liquid is electrically insulated and its permittivity is much less than that of the piezoelectric material. The solutions of dispersion relations are obtained for insulated liquid with electrically open or shorted conditions by means of transfer matrix method. The effects of the gradient variation of material constants on the phase velocity and attenuation are presented and discussed in detail. The analytical method and the results are useful for the design of the resonators and sensors.

Poly(ether ether ketone) (PEEK) was synthesized with a good yield, by nucleophilic substitution reaction of 4,4’-difluorobenzophenone (DFBP) with hydroquinone (HQ) in the presence of anhydrous potassium carbonate (K2CO3) under microwave (MW) irradiation. The highest yield of 96.1% was obtained using sulfolane as the solvent and with a reaction time of only 55 min. The reaction time was reduced greatly compared with conventional heating. The product was characterised by infrared spectroscopy (IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The polymer, having inherent viscosities of 0.71 dlg-1, has excellent thermal stability as shown by 10% weight loss in nitrogen at about 563 °C. The XRD pattern confirmed the semicrystalline character of PEEK synthesized.

The frequency–temperature characteristics of quartz crystal resonators, particularly the frequency stability in a specific temperature range in which the vibration modes are strongly coupled, has been an important requirement in most applications. The analytical work on frequency–temperature relations has been done over the last decades in many aspects, ranging from the fundamental theory for the thermal effect on vibrations of elastic solids to simplified plate equations of a few strongly coupled vibration modes. However, it has been clearly observed that due to complications of the resonator structures such as the presence of a mounting structure and electrodes, simple and analytical solutions will not be able to consider all the factors which will have inevitable and noticeable effects. In this paper, we incorporate the frequency–temperature theory for crystal plates based on the incremental thermal field formulation by Lee and Yong into our finite element analysis implementation, which is then used to analyze the free vibrations of crystal plates with the higher-order Mindlin plate theory. The effect of electrodes on the frequency–temperature relation is also considered. The computational results are compared with experimental ones from actual products. The satisfactory agreement demonstrates the precise prediction of the frequency–temperature behavior and practical applications of the finite element analysis in product modeling and development.

Alumina nanofibers of high aspect ratio with surface area of >300 m2 g−1 has been prepared successfully in bulk quantities by the sol–gel method. The synthesis parameters including the binary water–alcohol solvent system to aluminium isopropoxide ratio, pH, type of solvent and aging temperature affect the uniformity and formation of nanofibers. It is proposed that alumina nanofibers were formed by the curling of the nanosheets upon condensation after the hydrolysis. The phase evolution of alumina nanofibers from pseudoboehmite to α phase has been shown by XRD and FTIR. 27Al NMR investigations show that the Al atoms are six and four coordinated. The morphology of the alumina nanofibers does not change much as the calcination temperature was increased. In addition, the average pore size increases and the BET surface area decreases as a function of calcination temperature. The thermal behavior of alumina nanofibers was investigated by TGA.

A novel design method for high Q piezoelectric resonators was presented and proposed using the 3-D equations of linear piezoelectricity with quasi-electrostatic approximation which include losses attributed to mechanical damping in solid and resistance in current conduction. There is currently no finite element software for estimating the Q of a resonator without apriori assumptions of the resonator im- pedance or damping. There is a necessity for better and more realistic modeling of resonators and filters due to miniaturization and the rapid advances in frequency ranges in telecommunication. We presented new three-dimensional finite element models of quartz and barium titanate resonators with mechanical damping and resistance in current conduction. Lee, Liu and Ballato's 3-D equations of linear piezoelectricity with quasi-electro- static approximation which include losses attributed to mechanical damping in solid and resistance in current conduction were formulated in a weak form and implemented in COMSOL. The resulting finite element model could predict the Q and other electrical parameters for any piezoelectric resonator without apriori as- sumptions of damping or resistance. Forced and free vibration analyses were per- formed and the results for the Q and other electrical parameters were obtained. Comparisons of the Q and other electrical parameters obtained from the free vibra- tion analysis with their corresponding values from the forced vibration analysis were found to be in excellent agreement. Hence, the frequency spectra obtained from the free vibration analysis could be used for designing high Q resonators. Results for quartz thickness shear AT-cut and SC-cut resonators and thickness stretch poled barium titanate resonators were presented. An unexpected benefit of the model was the prediction of resonator Q with energy losses via the mounting supports.

Removal of Cu(II) and Cd(II) from wastewater using porous chitosan beads is likely to be enhanced by the introduction of thiol groups (−SH). This is because, in accordance with the Hard Soft Acid Base concept, the soft Lewis base of –SH forms a strong bond with soft Lewis acid of Cd(II) or with borderline Lewis acids such as Cu(II). Possible formation of thiourea and disulfide crosslinks (−S–S–) may also confer increased bead stability in acidic solution. Thiolated chitosan beads (ETB) prepared and investigated in this study had a total sulfur content of 7.9 %. The thiolation process slightly increased the Brunauer-Emmett-Teller surface area of the chitosan beads from 39.5 to 46.3 m2/g. This ETB was categorised as a microporous material (pore aperture: 1.8 nm) with multiple and uniform porous layers. Analysis by X-ray photoelectron spectroscopy indicated the presence of three sulfur species, S(−I), S(−II) and S(V) attributed to –S–S–, –SH and sulfonate (−SO3 −) groups. The Langmuir sorption capacity, q max, for Cd(II) was improved by 18 times by thiolation of chitosan. However, the q max for Cu(II) by ETB was seven times lower than that of pristine chitosan beads, possibly due to exhaustion of amine groups (−NH2). The batch sorption data was generally fitted well by a linearised Freundlich isotherm model and a Ho’s pseudo-second-order kinetic model, indicating metal interaction with the heterogeneous surface of ETB and chemical adsorption as the possible rate-limiting step, respectively. The metal uptake has resulted in the oxidation of –SH to –SO3 − group in ETB, thereby decreasing the stability of metal-sulfide bonds as well as their metal uptake.