Extravasation of contrast medium during CT examination: An observational casecontrol study

Introduction: extravasation is an adverse reaction to intravenous injection of contrast medium (CM) during CT examination. The objectives ofthis study are to determine the frequency, management and outcomes of extravasations and to assess risk factors for extravasation. Methods:every incident of extravasation which occurred between March 2012 and March 31, 2013 was recorded in an extravasation form. Ethics Committeeapproval was obtained and the patients gave their consent to participate in the study. Data collected in the form included patients' age, sex,  comorbidities, symptoms, CM used, injection mode, site and rate,  extravasated volume, location of extravasation, severity of injury,  treatment and patient outcome. Each case was matched with 4 controls of the same age ± 5 years and the same gender when possible.Results: extravasation occurred in 18 (7 women, 11 men) out of 2,000 injections of CM (0.9%) with a median age of 53 (10-78) years. Automated injection was performed in all cases with a mean rate of 1.7ml/s. Large  extravasated volumes (B 50ml) were more observed in patients  undergoing CT angiography (28.6% vs. 6.6%, although not significant P=0.112). Multivariate analysis revealed a significant association between patients with cardiac diseases and extravasation (OR: 7.3, 95% CI (1.09-49.05), P=0.04) whereas the injection rate is a protective factor from extravasation (P=0.002).Conclusion: extravasation of CM results in mild to moderate adverse effects in all cases. Our study suggests that patients with cardiac disease are more predisposed to contrast extravasation than others. Further and larger studies are needed to confirm this trend

The effect of the various doses of atorvastatin on renal tubular cells; an experimental study

Recent retrospective observational studies suggest that high-potency statin therapy might increase the risk of acute kidney injury, however data on this subject is scares. Objectives: This study, was designed to investigate the renal tubular cell effect of different doses of atorvastatin to detect the possible aggravation of renal function or morphology of the kidney. Materials and Methods: In this experimental study 24 male Wistar rats were designated into 4 equal groups and treated as follows. Control group received phosphate buffer as the vehicle of atorvastatin for 7 days. Groups 1, II and III received atorvastatin at doses of 10, 50 and 150 mg/kg daily for 7 days, then on the day 8, all rats were anesthetized using ketamine and the blood samples were collected for evaluation of creatinine (Cr) and blood urea nitrogen (BUN) levels and then all rats were sacrificed, then the animals’ kidneys were dissected out and histopathological studies were performed Results: Mean (±SD) of scores of injury to renal tubular cells in control group was 4.2 ±2.2 and in groups I, II and III were 6.44 ± 4.9, 15.4± 8.5 and 25.8 ± 12.7 respectively. Group III which received 150 mg/kg/day of atorvastatin had significant renal damage in comparison to control group (P < 0.001). There was no significant difference of renal injury score between control group with groups of I and II. Conclusions: In the present study we found, atorvastatin with a dose of 150 mg/kg/day for 7 days was nephrotoxic for rats, while lower doses at 10 mg/kg/day or 50 mg/kg/day for 7 days were not accompanied by renal injury. These findings imply further attention to the administration of higher doses of atorvastatin in clinical conditions

Comparing the patterns of hypertension and type 2 diabetes mellitus in patients with colorectal cancer

Background: Type 2 diabetes mellitus (DM) and hypertension are worldwide epidemic. Colorectal cancer (CRC) is the most prevalent gastrointestinal cancer in Iran. Prevalence of type 2 diabetes mellitus and hypertension in the patients with colorectal cancer had not reported in Iran, before this study. Methods: Overall, 2570 individual-year follow-ups were conducted for 1127 patients with colorectal cancer. For diagnosis of type 2 diabetes mellitus, fasting blood sugar and glycosylated hemoglobin tests were used and for that of hypertension, blood pressure was measured in two turns. The descriptive indices were calculated and the mean and median survivals, from colorectal cancer diagnosis time, were calculated using survival analysis and the comparison among survival times was done through log-rank test. Stata12 software was used for data analysis. Findings: The prevalences of hypertension and type 2 diabetes mellitus in the patients with colorectal cancer were 13.38 (95 CI: 11.1-15.8) and 8.69 (95 CI: 7.0-10.7), respectively. Median survival time in patients with hypertension and diabetes mellitus were 8.52 and 4.90 years, respectively. According to log-rank test, no significant difference was observed between the survival time of patients with colorectal cancer suffering from hypertension and type 2 diabetes mellitus. Conclusion: The obtained findings in this study indicate that survival time in patients with type 2 diabetes mellitus is less than those with hypertension; but two metabolic diseases have same effect on survival rate of the patients with colorectal cancer. © 2014, Isfahan University of Medical Sciences(IUMS). All rights reserved

3D Printing of a Photo-thermal Self-folding Actuator

The demand for rapid and accurate fabrication of light-weight, biocompatible, and soft actuators in soft robotics has perused researchers to design and fabricate such products by rapid manufacturing techniques. The self-folding origami structure is a type of soft actuator that has applications in micro electro mechanical systems, soft electronics, and biomedical devices. 3-dimentional (3D) printing is a current manufacturing process that can be used for fabrication of involute soft self-folding products by means of shape memory polymer materials. This paper presents, for the first time, a method for developing a photo thermal self-folding soft actuator using a 3D bioplotter. Easily accessible and inexpensive pre-strained polystyrene is opted for the backbone of actuator. The polystyrene film (PS) is then structured in a hand shape gripper. Chitosan hydrogel and carbon black ink were combined for printing active hinges on the hand gripper. Various active hinges with different widths and thicknesses were printed on the hand gripper using the 3D bioplotter. An infra-red (IR) heating lamp was placed at a reasonable distance to emit IR light uniformly on the hand gripper. The temperature distribution on the hand gripper was observed using a thermographic camera and the bending angles of the samples were recorded by a video camera. It was observed that the bending angles of the hand fingers depend on factors such as the intensity of the heat flux generated by the IR light intensity, distance, onset temperature, geometry of the fingers such as width and thickness, and area of the hinges

Surface nanogrooving of carbon microtubes

Extrusion processing of carbon tubes can be problematic due to their poor interfacial interactions with polymeric matrices. Surface chemical modification of carbon tubes can be utilized to create bonding sites to form networks with polymer chains. However, chemical reactions resulting in intermolecular primary bonding limit processability of extrudate, since they cause unstable rheological behaviour, and thus decrease the stock holding time, which is determinative in extrusion. This study presents a method for the synthesis of carbon microtubes with physically modified surface area to improve the filler and matrix interfacial interactions. The key concept is the formation of a nanogrooved topography, through acoustic cavitation on the surface of processing fibres. The effect of nanogrooving on roughness parameters is described, along with the role of surface modified carbon tubes on rheological behaviour, homogeneity, and coherency of extrudate. The measurements showed that nanogrooving increases the surface area of carbon microtubes, as a result, die swelling of the extrudate is reduced. Furthermore, after solidification, the mechanical strength of composite is reinforced due to stronger interactions between nanogrooved carbon tubes and polymer matrix

Effect of blowing agent concentration on cell morphology and impact properties of natural rubber foam

The concentration of sodium bicarbonate as a chemical blowing agent was varied to evaluate its effect on the morphology and impact properties of natural rubber foam. The expandable rubber samples were prepared using a conventional two-roll mill and were then expanded via a heat transfer foaming process using compression moulding and an air-circulating oven. The physical properties of the natural rubber foams were characterised, and the results were observed to systematically correlate with the impact properties of the foam. The absorbed energy of the foam increases with decreasing crosslink density and relative foam density, which is associated with the formation of smaller foam cells and an increase in the number of cells per unit volume

Accelerating Cosmologies and Inflation from M/Superstring Theories

We review the recent developments in obtaining accelerating cosmologies and/or inflation from higher-dimensional gravitational theories, in particular superstring theories in ten dimensions and M-theory in eleven dimensions. We first discuss why it is difficult to obtain inflationary behavior in the effective low-energy theories of superstring/M-theory, i. e. supergravity theories. We then summarize interesting solutions including S-branes that give rise to accelerating cosmologies and inflationary solutions in M-theory with higher order corrections. Other approaches to inflation in the string context are also briefly discussed.Comment: 38 pages, Invited review to be published in IJMPA, v2: slightly expanded and refs. added, v3, v4: typos corrected, published versio