[The technique of retaining part of the external auditory canal posterior wall with epitympanoplasty in soft wall reconstruction treating middle ear cholesteatoma].

Objective:To investigate the surgical treatment of cholesteatoma of the middle ear. Method:A retrospective analysis of patients from June 2013 to July 2016 diagnosed as cholesteatoma. 137 ears were divided into A group (retaining part of the external auditory canal posterior wall with epitympanoplasty in soft wall reconstruction for 75 ears) and B group (canal wall down mastoidotympanoplasty for 62 ears). the extent and damage of cholesteatoma were observed, comparing the time of dry ear and epithelial postoperative, the incidence of complications such as dizziness and hearing changes. Result:compared with B group, the postoperative dry ear time, epithelial time and hearing improvement in the A group were obviously improved, and the incidence of vertigo after operation was decreased, and the anatomical and physiological functions of the external auditory canal were protected. Conclusiont:The technique of retaining part of the external auditory canal posterior wall with epitympanoplasty in soft wall reconstruction is conductive to the removal of lesions and normal anatomical and physiological protection to external auditory canal, can prevent the forming of the abstraction pocket effectively and the recurrence of cholesteatoma, has clinical and practical value.

[Application of surgical cricothyrotomy in emergency and complicated airway management].

Objective:To explore the feasibility of intercricothyrotomy in emergency airway management. Method:Characteristics of 27 cases underwent surgical cricothyrotomy were analyzed. Result:The main causes of emergency were severe trauma of head and neck, larynx stenosis, interspaces infection of the floor of the mouth and submaxillary space, etc; all the patients were divided into 2 groups : surgical cricothyrotomy as the first choice (group A,16/27) and surgical cricothyrotomy after conventional tracheotomy (group B,11/27); The average time of opening airway for group A was much shorter than group B ï¼»(58.12±24.41)s, (739.09±245.29)s,respectively, P<0.01)ï¼½; Bleeding in group A (14 cases) was much less than group B (13 cases) ï¼»(2.36±1.16)ml, (4.65±4.31)ml,respectively, P<0.01ï¼½; Except 1 cases died from primary disease, 4 cases with laryngeal stenosis underwent laryngeal dilation with T type expansion tube and 2 cases of bilateral recurrent laryngeal nerve palsy, the average time with tracheal tube of the remaining 20 patients was (12.35±7.29)d, no postoperative complications such as larynx or tracheal stenosis were found. All of them were successfully extubation. Conclusion:Surgical cricothyrotomy procedure is fast and safe with simple and convenient that can be used as the preferred method of rapid airway opening when a critical respiratory tract was difficult to manage.

Superior pillared clay catalysts for selective catalytic reduction of nitrogen oxides for power plant emission control.

Fe(3+)-, Cr(3+)-, Cu(2+)-, Mn(2+)-, Co(2+)-, and Ni(2+)-exchanged Al2O3-pillared interlayer clay (PILC) or TiO2-PILC catalysts are investigated for the selective catalytic reduction (SCR) of nitric oxide by ammonia in the presence of excess oxygen. Fe(3+)-exchanged pillared clay is found to be the most active. The catalytic activity of Fe-TiO2-PILC could be further improved by the addition of a small amount of cerium ions or cerium oxide. H2O and SO2 increase both the activity and the product selectivity to N2. The maximum activity on the Ce-Fe-TiO2-PILC is more than 3 times as active as that on a vanadium catalyst. Moreover, compared to the V2O5-WO3/TiO2 catalyst, the Fe-TiO2-PILC catalysts show higher N2/N2O product selectivities and substantially lower activities (by approximately 85%) for SO2 oxidation to SO3 under the same reaction conditions. A 100-hr run in the presence of H2O and SO2 for the CeO2/Fe-TiO2-PILC catalyst showed no decrease in activity.