Simple Shear Versus Direct Shear Tests on Interfaces during Cyclic Loading

An apparatus capable of direct shear type and simple shear type testing of interfaces between soil and structural materials is developed. A series of monotonic and cyclic tests are conducted at the interfaces between dry sand and a rough surface under constant normal stress conditions with both methods. The test results indicate that the peak and residual shear strengths obtained from direct shear and simple shear are approximately the same. However, the simple shear box permits separate measurements of shear deformation of the sand mass and also sliding at the contact surface

Three-Dimensional Cyclic Behaviour of Interfaces

A new apparatus is used to study the behavior of an interface between dry sand and a rough surface under three dimensional cyclic loading conditions. A simple shear type of soil container is utilized in the experiments to investigate the coupling effects of two orthogonal shear stresses acting on the interface. The significance of the results are discussed with reference to the behavior of axially-laterally loaded piles

Comparing Cognitive Failures and Metacognitive Beliefs in Mild Traumatic Brain Injured Patients and Normal Controls in Kashan

Background: Head trauma is associated with multiple destructive cognitive symptoms and cognitive failure. Cognitive failures include problems with memory, attention and operation. Cognitive failures are considered as a process associated with metacognition. Objectives: This study aimed to compare cognitive failures and metacognitive beliefs in mild Traumatic Brain Injured (TBI) patients and normal controls in Kashan. Patients and Methods: The study was performed on 40 TBI patients referred to the Shahid Beheshti Hospital of Kashan city and 40 normal controls in Kashan. Traumatic brain injured patients and normal controls were selected by convenience sampling. Two groups filled out the demographic sheet, Cognitive Failures Questionnaire (CFQ) and Meta-Cognitions Questionnaire 30 (MCQ-30). The data were analyzed by the SPSS-19 software with multivariate analysis of variance. Results: The results of this study showed that there were no significant differences between TBI and controls in total scores and subscales of CFQ and MCQ (F = 0.801, P = 0.61). Conclusions: Based on these findings, it seems that mild brain injuries don't make significant metacognitive problems and cognitive failures

Mental Health Status of Patients With Mild Traumatic Brain Injury Admitted to Shahid Beheshti Hospital of Kashan, Iran

Background: Planning for providing mental health services to the mentally patients due to brain injury need awareness of mental health status of the patient. Objectives: This study aimed to assess the mental health of patients with mild TBI. Patients and Methods: The descriptive cross-sectional study was performed on 286 patients with mild TBI who were admitted to department of neurosurgery of Shahid Beheshti Hospital, Kashan, Iran, during the first eight months of 2013. Enrolled patients were 15 to 70 years old who able to respond to questionnaires. The Brief Symptom Inventory (BSI) questionnaire is used to assess the mental health status of the patients. The data were presented using logistic regression and descriptive statistics. Results: A total of 286 patients, 79.7% males and 20.3% females with male to female ratio of 4:1, completed the study. Female had significantly higher Global Severity Index (GSI) compared to males. There was a significant association between, psychologic disorders’ symptoms and age (P = 0.00). The mean (SD) of GSI on the Symptom Checklist-90 (SCL-90) was 1.39 (0.58). Conclusions: This study showed that 36% of the patients with mild TBI symptoms had mental health problems. Given the high rates of psychologic disorders among patients with mild TBI, it is necessary to reduce the factors that caused the disorder

Blunt Traumatic Hernia of Diaphragm With Late Presentation

Background: Diaphragmatic hernia after blunt trauma is an uncommon and often undiagnosed condition. Objectives: We aimed to review patients who presented with delayed blunt traumatic hernia of diaphragm. Patients and Methods: In this retrospective study, the medical records of six patients treated for blunt diaphragmatic hernias who were admitted to Kashan Shahid Beheshti hospital between June 2007 and June 2011 were analyzed. Results: Six patients with mean age of 41 years were included in the study. Male to female ratio was 2:1. Mean duration between trauma and admission to the hospital was 6.5 years (2 – 26 years). Five patients had left-sided diaphragmatic hernia. Chest X-ray was obtained from all patients which was diagnostic in 50 percent of the cases (n = 4). Additional diagnostic imaging with computerized tomography (CT) was used in six patients and upper gastrointestinal (GI) contrast study was performed in one patient. All patients underwent thoracotomy incision. Mesh repair was utilized in one patient. The mean hospitalization time was 14.1 days. There was one postoperative death (16.7%). Conclusions: Late presentation of blunt diaphragmatic hernia is an uncommon and challenging situation for the surgeon. Prompt diagnosis and treatment prevent serious morbidity and mortality associated with complications such as gangrene and perforation of herniated organ

Morphology of Rat Hippocampal CA1 Neurons Following Modified Two and Four-Vessels Global Ischemia Models

Background: An appropriate animal model of ischemia stroke is essential for evaluation of different therapeutic methods. Two and four-vessel global ischemia models are one of the most common types of transient cerebral ischemia. Objectives: In this study, the morphology of rat hippocampal CA1 neurons in modified models of two and four-vessel ischemia and reperfusion were evaluated. Materials and Methods: In this study, 20 Wistar rats were randomly divided into five groups. In group 2 and 3, both common carotid arteries were occluded for 10 minutes in either 3 or 24 hours of reperfusions, respectively. In group 4 and 5, both common carotid and vertebral arteries were occluded for 10 minutes in either 3 or 24 hours of reperfusions, respectively. Group 1 as control, underwent the whole surgery without any arteries occlusion. Hippocampi of the rats in all groups were processed and tissue sections were stained using the Nissl method. The morphology of CA1 neurons were studied under a light microscope and compared different groups. Results: In all groups ischemic changes were apparently observed in hippocampus CA1 neurons. In two-vessel occlusion model, after 3 and 24 hours of reperfusions, ischemic cells accounted for 14.9% and 23.2%, respectively. In four-vessel occlusion model, after 3 and 24 hours of reperfusions, ischemic cells accounted for 7.6% and 44.9% (P < 0.0001), respectively. Conclusions: Modified four-vessel occlusion model resulted in significant ischemic changes after 24 hours of reperfusion in CA1 neurons of rat hippocampus

Comparison of Artificial Neural Network and Logistic Regression Models for Prediction of Psychological Symptom Six Months after Mild Traumatic Brain Injury

Background: Nowadays, outcome prediction models using logistic regression (LR) and artificial neural network (ANN) analysis have been developed in many areas of healthcare research. Objectives: In this study, we have compared the performance of multivariable LR and ANN models, in prediction of psychological symptoms six months after mild traumatic brain injury. Methods: In a prospective cohort study, information of 100 mild traumatic brain injury patients, during a six months period between 2014 and 2016 were included. Data were divided into two training (n = 50) and testing (n = 50) groups, randomly. 300 ANNs and LRs were studied in the first group and then the predicted values were compared in the second group using the two final models. The receiver operating characteristic (ROC) curve and accuracy rate were used to compare these models. Results: The results showed that accuracy rate for the neural network model was 90.65, while it was 75.96 for the LR model. Conclusions: The ANN models appeared to be more powerful in predicting psychological symptoms versus the LR models