Need for explantation of an intrastromal titan ring after penetrating keratoplasty in two patients

The most severe complications after penetrating keratoplasty (PKP) include high astigmatism and immunological graft reaction. The introduction of the corneal intrastromal titan ring by Krumeich intended to reduce the incidence of both complications. We present two patients with keratoconus who referred to our department after a PKP combined with the implantation of an intrastromal ring. The first patient suffered from bulbar pain and headaches. The second patient suffered from postoperative high myopia, irregular astigmatism and was contact lens intolerant. In the first patient we recognized anterior movement of the ring inside the stroma and decided to remove it. The second patient was found to have extreme bulging of the transplant. We removed the ring and sequentially performed a repeat-PKP. In both patients the implantation of the ring failed to decrease the postoperative astigmatism and caused symptoms that affected the patients’ everyday life. Therefore, we recommend not to use this titan ring.

Synthesis and Characterization of an Amphiphilic Nanoparticles Based on Chitosan Oligosaccharide-Grafted-Polycaprolactone

The amphiphilic chitosan oligosaccharides graft copolymer (PHCSO-g-PCL) was synthesized via ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) through an amino group protection route using phthaloyl chitosan oligosaccharide (PHCSO) as intermediate. The graft reaction was carried out in Pyridine at 120 °C with a chitosan oligosaccharide (CSO) initiator and a tin 2-ethylhexanoate (Sn (Oct)2) catalyst. The amphiphilic PHCSO-g-PCL nanoparticles were prepared through the self-assembled in DMF organic solvents. PHCSO-PCL copolymer was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The physicochemical properties of the hydrophobized PHCSO-g-PCL nanoparticles were investigated by using dynamic light scattering (DLS). The results of DLS showed that the hydrodynamic diameters and particle size distribution with various concentrations of PHCSO-g-PCL nanoparticles were from 69.82 nm to 195.9 nm with a narrow polydispersity factor of 0.212 to 0.172.

Study on Structure Design and Properties of Super Absorbent Copolymerized with Milk Protein Grafted Acrylic Acid

Super absorbent resin(SAR) is a kind of contains strong hydrophilic groups such as carboxyl with certain degree of water swelling type crosslinking polymer. Because it can absorb their hundreds and even thousands of times of water, which are widely used in health product 、dewatering of coal seam and many other fields [1].At present ， there is few study on water absorption performance of protein grafted acrylic acid absorbent resin. Therefore, this article selects the pure milk of JiaBao dairy company production , conducted a series of graft reaction, studied the influence factors such as the initiator, cross-linking agent, neutralization degree ,consumption of milk and PH sensitivity.

The Synthesis and Application of Photoinitiators Chitosan-Graft-Acrylamide Polymer Flocculants

Chitosan and acrylamide were used for graft reaction by photoinitiator, and flocculation performance of grafted product was also studied. In addition, the impact of the trigger system, reaction time and temperature on product performance were discussed in detail. Structure property of the product was characterized by infrared spectroscopy. It is found that the highest stem grafting rate of graft copolymer can reach 239.4 % using this process, and the specific viscosity of product can reach 820 ml/g. The flocculation test was done by coal slurry water, and its result shows that the light transmission rate of slime water is up to 98.7 %.