Tissue Stretching Device

This tissue loading project consists of designing an apparatus that has two main functions. The first, and most obvious of these, being creating a device that will deform a band or disk of tissue with cells pre-seeded on them uniaxially while recording the stress and strain, specifically strain rate, that is applied to the tissue. While the deformation aspect of this device will be key, an equally important part of this project will be designing a part of our tissue loader that mimics the environmental chamber that the lab already uses or is compatible with the environmental chamber that is already in use. This is key when dealing with cells as the slightest disturbance in environment can lead to cell death and therefore inconclusive research results

Hemodynamic Effects on Aortic Development Due to Outflow Tract Banding

Hemodynamic forces drive remodeling of the early cardiac system in embryonic development. Perturbations of normal cardiac blood flow can cause the formation of defects and malformations within the cardiac system. Specifically, changes in hemodynamics can cause the formation of different congenital heart defects. The formation of heart defects has been studied; however, vasculature specific defects caused by changes in blood flow patterns in the early cardiac system have not been studied to the same degree. In this thesis, the effects of hemodynamic changes on arterial development were studied. Outflow tract banding (OTB) was used to cause a local increase in peak blood flow velocity in the outflow tract (OFT) of the early chick embryonic heart and resultant changes in the downstream dorsal aorta (DA) were studied. OTB was performed at 3 days of incubation, the suture was removed 24 hours later, and the embryo was studied at different time points up to 18 days of incubation. Hemodynamic measurements were taken at the OFT and the DA before and after OTB to see how changes in blood flow patterns in the early embryonic cardiac system affect development of the DA and its extracellular matrix (ECM) proteins. Elastin and collagen were of specific interest. Doppler ultrasound was used to show that OTB led to an increase in blood velocity in the OFT after banding and a decrease in velocity in the DA after 3 days of incubation (immediately after suture removal). No difference in DA velocity was seen at 10 days of incubation (6 days after suture removal). Two-photon imaging was used to show that changes in blood flow velocity due to OTB caused no discernable difference in aortic elastin or collagen organization through 11 days of incubation. It is likely that longer incubation periods (beyond 11 days) are needed in future work to investigate changes in the DA ECM amount and organization due to OTB

Consumer Response in out of Stock Situation at a Retail Store

Abstrac

Detection of cervical spine trauma: Are 3-dimensional reconstructed images as accurate as multiplanar computer tomography?

Introduction: This study was conducted to assess the diagnostic accuracy of three-dimensional computed tomography (3D-CT) in detection of cervical spine injuries in symptomatic post-trauma patients using multiplanar computed tomography (MP-CT) as reference standard.Approach: This cross-sectional study was conducted at Aga Khan University from July 2016 to January 2017. Patients were included using a non-probability, consecutive sampling. MP-CT and 3D- CT images were obtained and evaluated by a senior radiologist to identify cervical spine injuries.Results: 205 patients were included in the study. For fractures, 3D-CT images had sensitivity of 71%, specificity of 100%, positive predictive value (PPV) of 100%, negative predictive value (NPV) of 96.8% and diagnostic accuracy of 97%. For dislocations, 3D-CT reported sensitivity of 83.34%, specificity of 100%, positive predictive value of 100% and negative predictive value of 99.5% and diagnostic accuracy of 99.5%.Conclusion: 3D-CT has good diagnostic accuracy for injuries of the cervical spine but must be reviewed simultaneously with multiplanar CT images

Diagnostic accuracy of computed tomography in differentiating peritoneal tuberculosis from peritoneal carcinomatosis

Introduction: Peritoneal tuberculosis is difficult to diagnose as it may mimic peritoneal carcinomatosis, which has similar symptomatology. We sought to determine the diagnostic accuracy of computed tomography in differentiating peritoneal tuberculosis versus peritoneal carcinomatosis.Materials and methods: The associations of radiological findings in 124 patients with peritoneal carcinomatosis (n = 55) or tuberculosis (n = 69) were determined using Chi-square test. Sensitivity, specificity, positive and negative predictive value, and total diagnostic accuracy of CT imaging, with histopathology as gold standard, was determined. Subgroup analyses to determine these parameters by age (\u3e40 years and ≤40 years) and gender (male and female) were performed.Results: Mean age of study population was 44.1 ± 13.2 years with 61 males (49.2%) and 63 females (50.8%). The most common radiological abnormality in both peritoneal carcinomatosis (90.9%) and peritoneal tuberculosis (89.9%) was omental smudging, followed by presence of extraperitoneal mass (81.8%) in carcinomatosis and presence of micro-nodules in tuberculosis (88.4%). The findings significantly different in both the carcinomatosis and tuberculosis groups were high-density ascites, splenic calcification, splenomegaly, lymph node calcifications, micro-nodules, and macro-nodules. The diagnostic accuracy of CT in differentiating peritoneal tuberculosis from peritoneal carcinomatosis was 83.8%; sensitivity and specificity for peritoneal tuberculosis were 88.4% and 78.2%, respectively.Conclusion: The diagnostic accuracy of CT in differentiating peritoneal tuberculosis from peritoneal carcinomatosis revealed an overall diagnostic accuracy of 83.8%. Subgroup analysis revealed that CT may be a more specific diagnostic tool to predict peritoneal tuberculosis in female patients and in those over 40 years old