Assessment of risks of tunneling project in Iran using artificial bee colony algorithm

The soft computing techniques have been widely applied to model and analyze the complex and uncertain problems. This paper aims to develop a novel model for the risk assessment of tunneling projects using artificial bee colony algorithm. To this end, the risk of the second part of the Emamzade Hashem tunnel was assessed and analyzed in seven sections after testing geotechnical characteristics. Five geotechnical and hydrological properties of study zone are considered for the clustering of geological units in front of tunneling project including length of tunnel, uniaxial compressive strength, rock mass rating, tunneling index Q, density and underground water condition. These sections were classified in two low-risk and high-risk groups based on their geotechnical characteristics and using clustering technique. It was resulted that three sections with lithologies Durood Formation, Mobarak Formation, and Ruteh Formation are placed in the high risk group and the other sections with lithologies Baroot Formation, Elika Formation, Dacite tuff of Eocene, and Shear Tuff, and Lava Eocene are placed in the low risk group. In addition, the underground water condition and density with 0.722 and 1 Euclidean distances have the highest and lowest impacts in the high risk group, respectively. Therefore, comparing the obtained results of modelling and actual excavation data demonstrated that this technique can be applied as a powerful tool for modeling risks of tunnel and underground constructions

Total Phenytoin concentration is not well correlated with active free drug in critically-ill head trauma patients

Objective: Phenytoin is an antiepileptic drug used widely for prophylaxis and treatment of seizure after neurotrauma. Phenytoin has a complex pharmacokinetics and monitoring of its serum concentrations is recommended during treatment. Total phenytoin concentration is routinely measured for monitoring of therapy. In this study, we evaluated the correlation between phenytoin total and free concentrations in neurotrauma critically-ill patients to determine whether the phenytoin total concentration is a reliable predictor of free drug, which is responsible for the therapeutic effects. Methods: A total of 40 adult head trauma patients evaluated for free (unbound) and total serum phenytoin concentrations. Patients were divided into two groups. Group A consists of 20 unconscious patients with severe head injury under mechanical ventilation and Group B consists of 20 conscious self-ventilated patients. Correlation and agreement between total and free phenytoin plasma concentrations were analyzed. Findings: Pearson correlation analysis and Bland-Altman test showed weak to moderate correlation (r = 0.528) and poor agreement between free and total phenytoin concentrations in patients with severe trauma and higher Acute Physiology And Chronic Health Evaluation II (APACHE II) scores (Group A) and good correlation (r = 0.817) and moderate agreement in patients with mild to moderate trauma and lower APACHE II scores (Group B). Conclusion: Our results indicated that total phenytoin serum concentration is not a reliable therapeutic goal for drug monitoring in severely-ill head trauma patients even in the absence of hypoalbuminemia, renal and hepatic failure. It seems justifiable to measure free phenytoin concentration in all severely ill neurotrauma patients