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To determine the endoscopic release superficially rather than deep to the transverse carpal ligament to reduce the incidence of transient symptomatic exacerbation and postoperative absence from work in patients with carpal tunnel syndrome.From January 2012 to January 2018, patients with idiopathic carpal tunnel syndrome who underwent one-portal endoscopic release superficial to the transverse carpal ligament (ERSTCL) were analyzed. For comparison, a cohort treated with the conventional Chow endoscopic release between February 2008 and October 2013 were included. Transient worsening of symptoms, discrimination sensation, and days off work were assessed. The minimal clinically important difference was calculated for discrimination sensation. Severity of symptom and functional status also were assessed using the Levine-Katz Questionnaire. Significance was set at P.05.There was a significant difference between the ERSTCL group and the control group regarding the incidence of symptomatic exacerbation 1 week after surgery (2% vs 9%; P = .003) but no difference in other time intervals within the initial 3 months. There was a significant difference in 2-point discrimination 1 week (mean change = -0.13, 95% confidence interval [CI] -0.30 to 0.04, P = .01) and 2 weeks after surgery (mean change = -0.18, 95% CI -0.36 to -0.01, P = .033). Postoperative 1 and 2 weeks, 28% and 35% patients in ERSTCL group achieved a minimal clinically important difference, respectively. Compared with control group, the difference in frequencies was statistically significant (28% vs 45%; P = .027; 35% vs 57%; P = .015). The difference between the 2 groups in postoperative absence from work was statistically significant (95% CI 1.083-4.724; P = .002), with an average reduction in sick leave of 3 days in ERSTCL group. At a mean follow-up of 3 years, no significant difference was found between the groups regarding symptom and function statuses.Endoscopic release superficial rather than deep to transverse carpal ligament for carpal tunnel syndrome improves immediate postoperative transient symptomatic exacerbation, which allows the patients to return to work earlier.Level III, retrospective comparative study.

Wind-thermal-bundled power system is widely applied to solve the grid interconnection of wind farms, but it brings the high risk of subsynchronous oscillation (SSO) which is a threat to turbo generator and the stability of system. Conventional static excitation system uses Supplementary Excitation Damping Control (SEDC) to suppress SSO, but the response time is limited by the excitation winding time constant. Besides SEDC, flexible excitation system can provide an extra damping channel controlled by Subsynchronous Damping Controller (SSDC). This paper proposes a novel SSDC and its corresponding control method for flexible excitation system. Then the effect of SSDC is analyzed by complex torque coefficient method. Finally, the oscillation suppression effect of SEDC, SSDC and SEDC together with SSDC are compared by simulation with PSCAD/EMTDC.

This study was to assess the survival outcome of cutaneous melanoma (CM) patients with surgery vs non-surgery through inverse probability of treatment weighting (IPTW) using the propensity score. Patients diagnosed as CM were selected from the Surveillance, Epidemiology, and End Results Program (SEER) database. The survival outcome was estimated and compared by IPTW using the propensity score. Totally 2203 CM patients were identified, in which 1921 cases received surgical treatment (surgery group), while 282 cases didn't (non-surgery group). The median survival time of surgery and non-surgery groups was respectively 150 months and 15 months (unmatched cohort), 70 months and 40 months (matched cohort) and 130 months vs. 75 months (IPTW-weighted cohort). Compared with the non-surgery group, the surgery group had a lower risk of death in unmatched [hazard ratio (HR): 0.647, 95% confidence interval (CI): 0.509-0.821, P

Summary The widely used nerve transfer sources for elbow flexion in patients with upper brachial plexus avulsion (UBPA) include partial ulnar nerve, phrenic nerve, and intercostal nerves. A retrospective review of 21 patients treated with phrenic and partial ulnar nerve transfers for elbow flexion after UBPA was carried out. In the phrenic nerve transfer group, the phrenic nerve was transferred to the anterolateral bundle of the anterior division of the upper trunk; in the partial ulnar nerve transfer group, one fascicle of the ulnar nerve was transferred to the biceps branch. The British Medical Research Council (MRC) grading system, angle of elbow flexion, electromyography (EMG), and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire scoring were used to evaluate the recovery of elbow flexion at least 3 years postoperatively. The efficiency of motor function in phrenic nerve transfer group was 82%, whereas it was 80% in partial ulnar nerve transfer group. The outstanding rates of angle of elbow flexion were 64% and 70% in phrenic and partial ulnar nerve transfer groups, respectively. The DASH scores after surgery were significantly lower than those before surgery in the two groups. There was no statistical difference between the two groups in the changes of DASH scores before and after surgery. Both of phrenic and partial ulnar nerve transfers had good prognosis for elbow flexion in patients with UBPA.

A three-level H-bridge chopper using neutral point clamped technology is proposed for high ceiling voltage VSC excitation system to suppress overvoltage stress and shaft voltage. Highlighting with neutral point voltage balance control, the switching states of the three-level H-bridge chopper is specially designed and implemented for excitation voltage control. A prototype is fabricated and the laboratory test with small generator is carried out for verification.

A novel dual-channel damping control based on voltage source converter (VSC) excitation system is put forward in this paper to suppress subsynchronous oscillation for turbine generators. The proposed control is a combination of both supplementary excitation damping control (SEDC) and supplementary subsynchronous damping control (SSDC) but only implemented in one device. A small perturbation linearized model considering the dual-channel damping is built and the complex torque coefficients method is adopted to analyze the damping characteristic of the proposed control. Based on the analytical analysis, a decoupling tuning method for the dual-channel damping control is proposed. The effectiveness and superiority of the proposed subsynchronous damping control are verified through PSCAD simulation.