mohammad hoseinzade

Nowadays, according to the global population growth, building and automobile generation are increasing. Hence, the vehicle collision to structures is increasing too, and these events may cause more vulnerability on structures. That's why, these structures need to be re-evaluated for strengthening and rehabilitating, but this issue is usually ignored and neglected. For this reason, in this study has been made an effort to determine, the rate of concrete structure vulnerability under vehicle collision on corner and middle columns with 10, 60 and 100 km/h speeds with19 seismic records simultaneously as incremental dynamic analysis (IDA). Also this speeds may be define as low, medium and high speeds. At initiation, by ETABS software and according to Iran's seismic design code of buildings (4th edition) a concrete structure with intermediate moment frame system was designed. Then to obtain the force-time spectrum, the vehicle collision and a concrete structure was simulated by LSDYNA software. After that this building was analysed under several force-time spectrum and 19 seismic records in near field. After that the fragility curves due to incremental dynamic analysis (IDA) were drawn. Finally, according to failure indicators from HAZUS standard, the probability of damage from vehicle collision and 19 seismic records on corner and middle columns was evaluated. Then it was specified, the collision causes permanent deformations on structural elements and increasing in vehicle speed will increase the horizontal displacement of story and reduces the base shear, as well as increases the rate of damage on structure finally. For instance, the rate of displacement ratio from vehicle collision to concrete structure with 10, 60 and 100 speeds, which indicates the rate of damage, applied on structure is equal 0.00152, 0.00515 and 0.023.

There are different ways to design energy dissipators. According to the type of performance of these elements, it is better to adopt the design method according to the consumed energy in order to determine what load should be considered as the design load for the energy-dissipating elements so that these elements have the best seismic performance. One of these methods is the use of energy-based performance index. This method is usually used to design pall friction dampers. In this research, it has been tried to use this method for a 12-story reinforced concrete structure of friction dampers, viscous, and seismic isolators of the lead rubber support type, and their performance is investigated. Based on this, for the earthquake records, the energy-based performance index has been calculated and the optimal design load has been calculated for these three energy wasters. Structures with optimal design load are subjected to dynamic loads and the contribution of elements in energy loss and their fragility curve have been evaluated. The results show that in a constant spectral acceleration (Sa), the probability of exceeding the specified performance level of a structure with a friction damper that is designed on this basis is lower than other structures. Also, in the acceleration of the design, the seismic isolator has wasted more energy than the other two structures.

Efforts to control the COVID-19 pandemic are still on. This study aimed to evaluate the effect ofsofosbuvir on length of hospital stay and complications in COVID-19 cases with moderate severity.

This randomized clinical trial was done on moderate COVID-19 cases, who were admitted to Shohadaye TajrishHospital, Tehran, Iran, from 4/2021 to 9/2021. Eligible patients were randomly allocated into two groups ofintervention (sofosbuvir) and control, and their outcomes were compared regarding the length of hospital stayand complications.

100 COVID-19 cases were randomly divided into two groups of 50 patients, asthe intervention and control groups. The mean age of patients was 50.56 ± 12.23 and 57.1±14.1 years in theintervention and control groups, respectively (p = 0.02). The two groups were similar regarding distribution ofgender (p = 0.15), underlying diseases (p = 0.08), the severity of COVID-19 (p = 0.80) at the time of admission,signs and symptoms (p > 0.05), and essential laboratory profile (p > 0.05). The length of hospital stay in thecontrol and intervention groups was 7.7 ± 4.09 days and 4.7±1.6 days, respectively (p = 0.02). None of our patientsneeded ICU or mechanical ventilation.

Sofosbuvir may decrease the length of hospital stay ofCOVID-19 cases with moderate severity, without a significant effect on the rate of intensive care unit (ICU) needand mortality.