Clinical Efficacy of Radiofrequency Cervical Zygapophyseal Neurotomy in Patients with Chronic Cervicogenic Headache

The purpose of the present study was to assess the clinical efficacy of radiofrequency (RF) cervical zygapophyseal joint neurotomy in patients with cervicogenic headache. A total of thirty consecutive patients suffering from chronic cervicogenic headaches for longer than 6 months and showing a pain relief by greater than 50% from diagnostic/prognostic blocks were included in the study. These patients were treated with RF neurotomy of the cervical zygapophyseal joints and were subsequently assessed at 1 week, 1 month, 6 months, and at 12 months following the treatment. The results of this study showed that RF neurotomy of the cervical zygapophyseal joints significantly reduced the headache severity in 22 patients (73.3%) at 12 months after the treatment. In conclusion, RF cervical zygapophyseal joint neurotomy has shown to provide substantial pain relief in patients with chronic cervicogenic headache when carefully selected

Nano-structured Pt–Cr anode catalyst over carbon support, for direct methanol fuel cell

In this study, several kinds of carbon were used as the support for the Pt-based catalyst of the direct methanol fuel cell (DMFC). Mesoporous carbons with large BET surface area and a commercial carbon were used as the support for the anode catalyst. The maximum current densities of the catalysts were compared by cyclic voltammogram. The catalyst supported on Vulcan XC-72, the commercial carbon support, showed the highest catalytic activity because of its high electric conductivity in spite of small BET surface area. Transition metals such as Cr, Mn, Y, or Zn were impregnated simultaneously with a Pt precursor on Vulcan XC-72, respectively, and then the catalytic activity was tested. The Pt–Cr/C catalyst showed the highest catalytic activity among this catalyst series, and was more active than the Pt/C catalyst. Furthermore, in order to improve the activity of the Pt–Cr/C catalyst, sintering of active metals by thermal reduction during the preparation should be avoided. Therefore, alkaline aluminum leaching method was applied for the purpose of decreasing the particle size of the active metals by reducing the sintering of Pt and Cr. Aluminum precursor was introduced together with Pt and Cr precursors into the commercial carbon support in the preparation process. After reduction of the sample, aluminum species were selectively leached out. The catalyst showed a much improved activity as expected and characterized by H2 chemisorption and TEM analyses.the Korea Science and Engineering Foundation through the Research Center for Energy Conversion and Storage, and by the Ministry of Science and Technology of Korea through the Research Center for Nanocatalysis, one of the National Science Programs for Key Nanotechnolog