In the present work, we address the new route for the green synthesis of manganese dioxide (MnO2) by an innovative method named the solution plasma process (SPP). The reaction mechanism of both colloidal and nanostructured MnO2 was investigated. Firstly, colloidal MnO2 was synthesized by plasma discharging in KMnO4 aqueous solution without any additives such as reducing agents, acids, or base chemicals. As a function of the discharge time, the purple color solution of MnO4 - (oxidation state +7) was changed to the brown color of MnO2 (oxidation state +4) and then light yellow of Mn2+ (oxidation state +2). Based on the UV-vis analysis we found the optimal discharging time for the synthesis of stable colloidal MnO2 and also reaction mechanism was verified by optical emission spectroscopy (OES) analysis. Secondly, MnO2 nanoparticles were synthesized by SPP with a small amount of reducing sugar. The precipitation of brown color was observed after 8 min of plasma discharge and then completely separated into colorless solution and precipitation. It was confirmed layered type of nanoporous birnessite- MnO2 by X-ray powder diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), and electron microscopes. The most important merits of this approach are environmentally friendly process within a short time compared to the conventional method. Moreover, the morphology and the microstructure could be controllable by discharge conditions for the appropriate potential applications, such as secondary batteries, supercapacitors, adsorbents, and catalysts.

This case report describes satisfactory correction of deep and large canine corneal ulcerations by application of bidirectional corneo-conjunctival transposition (CCT). A 12-year-old spayed female Maltese dog with a large corneal descemetocele, perforation, and blepharospasm of the right eye was referred to Chungbuk National University Veterinary Teaching Hospital. More than half of the thickness of the cornea was damaged, and the ulcer was progressive. On ophthalmic examination, menace response and dazzle reflex were absent. No corneal melting was observed. As the patient had large and deep corneal ulcers, traditional one-sided CCT was not sufficient to cover the wound lesion. To increase corneal transparency after recovery, we decided to perform bidirectional CCT from 12 o’ clock on the dorsal side to 7 o’ clock on the ventral side. The dog was medicated with topical eye drops, ofloxacin, atropine, and moxifloxacin before surgery. Debridement with a diamond burr was then performed around the descemetocele. Five weeks after surgery, the dazzle reflex was restored as the blood vessel receded from the cornea to the conjunctiva. Eight weeks after surgery, corneal transparency and corneal stability were gradually restored, but not completely. Bidirectional CCT provides structural support and helps corneal wound healing in large canine corneal ulceration.