Determination Method on Initial Pretension of Cables in Steel Mega Frame and Prestressed Composite Bracing Structure

Determining initial pretension values of pre-stressed cables is one of the key problems for a steel mega frame and pre-stressed composite bracing structure.Through the mechanical analysis of the composite bracing under vertical loading,the critical factors deciding the initial pretention value were found.According to these factors,a rule for the initial pretension value was put forward.The determination equations were acquired based on the principle of force equilibrium at nodes.The numerical results indicate that the internal force disequilibrium in composite bracings resulted from symmetrical load can be eliminated only in a symmetrical way,so that initial pretention values are decided only by vertical loads.The influencing coefficient leveling method,taking into account interactions between story and story,is accurate and feasible.

Nail Changes as the Initial Sign of Psoriasis: A Case Report

Introduction:Nail psoriasis has a profound negative influence on quality of life and has a more closely relationship with psoriatic arthritis.However,patients with nail changes only were often overlooked with the diagnosis of psoriasis.It is necessary to pay more attention to nail psoriatic changes.Herein,we report a 24-year-old male patient with nail changes as the initial sign of psoriasis who was finally diagnosed with nail psoriasis.Case presentation:The nails presented with white streaks,deformations,and had been missed for 8 months.Physical examination further revealed one erythematous scaly plaque on the buttock,anusand scalp respectively with positive Auspitz sign.Combined with the negative fungal microscopic,dermoscopic results and pathological results,the diagnosis of nail psoriasis was made.Oralacitretin(30 mg/day)and topical calcipotriene liniment was prescribed for 3 months followed with etanercept(50 mg once per week),and the nail symptoms were well controlled.Discussion:Nail psoriasis is usually noticed after the occurrence of skin lesions,but may occur simultaneously with or before skin psoriasis.Occasionally,nail involvement is the only manifestation of psoriasis.Nail lesions maybe one of the strongest clinical predictors of psoriatic and it has a profound negative influence on quality of life,so that timely recognition and proper treatment are improtant.Conclusion:Nail psoriasis can cause substantial physical and psychological impairment.However,nail involvement is an often overlooked feature of psoriasis.More attention should be paid to nail psoriatic changes and the administration of appropriate treatment.