Asymmetrical traumatic bilateral hip dislocations with hemodynamic instability and an unstable pelvic ring: Case report and review of literature

Simultaneous anterior and posterior traumatic dislocations of both hips are very rare. Only 33 cases have been previously reported in the English language literature. Although they were all due to high-energy injuries, they were hemodynamically stable and had a stable pelvic ring. We report a unique case of asymmetrical hip dislocations with an unstable pelvic ring and hemodynamic instability. A 40-year-old man was injured in a high-energy motor vehicle accident. He was hemodynamically unstable when he presented in the emergency department. Radiolographs showed asymmetrical dislocations of both hips with an unstable pelvic ring. Under general anesthesia, he had closed reduction of the dislocations of both hips, followed by temporary stabilization with an external fixator. Transcatheter arterial embolization was performed to stop active pelvic bleeding. Delayed open reduction and internal fixation was performed 12 d later with anterior and posterior plates. The patient recovered well with an uneventful post-operative course. Asymmetrical bilateral hip dislocations with pelvic ring instability caused by trauma, as presented in this case, is very rare and potentially life threatening. Prompt treatment can give a good outcome.

One-pot synthesis of nickel-cobalt hydroxyfluorides nanowires with ultrahigh energy density for an asymmetric supercapacitor

A novel and unique nickel-cobalt hydroxyfluorides(NiCo-HF)nanowires material is fabricated by one-pot solvothermal synthesis method for asymmetric supercapacitor.The synthesis mechanism and factors that influence the formation of the Ni Co-HF nanowires have been further discussed.The as-prepared NiCo-HF electrode exhibits a high specific capacitance of 3,372.6 F g^(à1),and the capacitance retention of 94.3%can be achieved at a high current density of 20 A g^(à1)after 10,000 cycles.The outstanding electrochemical performance of the electrode can be attributed to the synergistic effect of the nanowires morphology and complicated redox process of active material.Furthermore,an asymmetric supercapacitor assembled with Ni Co-HF nanowires as positive electrode and activated carbon as the negative electrode shows an ultrahigh energy density of 83.6 Wh kg^(à1)at a power density of 379.4 W kg^(à1)and an excellent cycling stability with 86.3%capacitance retention after 10,000 cycles,indicating that this novel material has great promise for potential application in energy storage device.

Histogram-kernel Error and Its Application for Bin Width Selection in Histograms

Histogram and kernel estimators are usually regarded as the two main classical data-based nonparametric tools to estimate the underlying density functions for some given data sets. In this paper we will integrate them and define a histogram-kernel error based on the integrated square error between histogram and binned kernel density estimator, and then exploit its asymptotic properties. 3ust as indicated in this paper, the histogram-kernel error only depends on the choice of bin width and the data for the given prior kernel densities. The asymptotic optimal bin width is derived by minimizing the mean histogram-kernel error. By comparing with Scott＇s optimal bin width formula for a histogram, a new method is proposed to construct the data-based histogram without knowledge of the underlying density function. Monte Carlo study is used to verify the usefulness of our method for different kinds of density functions and sample sizes.