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Background To investigate the clinical safety and efficacy of foldable capsular vitreous body (FCVB) in the treatment of severe silicone oil-dependent eyes. Methods Five patients (5 eyes) of severe silicone oil-dependent eyes underwent FCVB implantation from December 2019 to July 2020. The preoperative and postoperative visual acuity, intraocular pressure, corneal conditions, postoperative retinal reattachment, and FCVB status were observed. The patients were followed up for 12-15 months. Results A total of 5 patients (5 eyes) with severe silicone oil-dependent eyes were included, including 3 males and 2 females, with an average age of 32±14 years. The longest silicone oil tamponade time was 8 years, and the shortest was 2 years, with an average of 5±3 years. All patients were safely and successfully implanted with FCVB without severe intraoperative or postoperative complications. Up to the last follow-up, there was no significant change between preoperative and postoperative visual acuity. Before surgery, 4 patients had normal intraocular pressure while 1 patient had ocular hypotension; after surgery, the latter was still at a low level, and the other patients had intraocular pressure in the normal range. Conclusions The FCVB is a safe, feasible, and effective vitreous substitute to maintain ocular morphology and intraocular pressure without aggravating silicone oil emulsification, retinal displacement, or corneal degeneration during the implantation period of 12-15 months.

The reduction of α-pinene by NaBH4 was achieved using NiCl2•6H2O in PEG-800/ethanol system under room temperature. Under the optimized conditions, the conversion of α-pinene and the selectivity of cis-pinane reached 97% and 98%, respectively. On the basis of TEM and a series of poisoning experiments, the nature of the active catalytic species for the reaction was discussed.

To achieve the integrity of solid particles coated by water phase (S/W/O) compound droplets, it is important to investigate the transport process of the compound droplets in the horizontal straight channel. The experimental results show that the integrity is significantly influenced by the flow rates and density difference. The water (W) phase is observed to be peeled off from the surface of the particles (polystyrene (PS) shells), mainly caused by the slip velocity of the W phase and the density mismatching among three phases. During the peeling off process, a relative motion between the solid (S) and W phases initially occurs, causing a decrease of the distance (δ) between them, and then, the PS shell is driven to pass through the W/O interface under the action of drag force and net gravity. It is also found that increasing flow rates of both phases contributes to obtaining integrated compound droplets. A boundary that separates the integrated from damaged compound droplets also exits when the fluid properties are fixed. Above the line of the boundary, compound droplets with integrity are prepared. Moreover, the absolute optimum density matching between the S and W phases is less than 0.003 g/cm3, while that between the W and oil (O) phases is less than 0.005 g/cm3.

In the procedures of designing polystyrene-polyvinyl alcohol-CH (carbon and hydrogen elements) (PS-PVA-CH) triple-layer microspheres, there are many methods such as drop-tower technique, emulsion micro-encapsulation, dip (spin) coating, interfacial polycondensation, and spraying technique to prepare the PVA coating. Drop-tower technique, emulsion micro-encapsulation and dip (spin) coating are most-commonly used. The advantages, disadvantages and the research progress of the three methods are summarized in this paper. Emulsion micro-encapsulation is suitable for preparing double-layer microspheres of sizes smaller then 500 m, with high survival ratio and good quality. However,the preparation process is easily influenced by artificial factors. Small-sized double-layer microspheres can also be prepared by the drop-tower technique, and the preparation period is short. But there are still some problems such as the difficulty in designing thedroplet generator, uneven PVA coating and the difficulty in preparing large-sized microspheres. Dip (spin) coating technique can be used to prepare PS-PVA microspheres with sizes larger than 1000 m, but the spread of PVA coating is affected by many factors in this method, and the prepared PVA coating is too thin and not uniform.