Volume Threshold for Chest Tube Removal: A Randomized Controlled Trial

Background: Despite importance of chest tube insertion in chest trauma, there is no ‎general agreement on the level of daily volume drainage from chest tube. This study ‎was conducted to compare the effectiveness and safety of chest tube removal at the ‎levels of 150 ml/day and 2oo ml/day. Methods: Eligible patients (138) who needed replacement of chest tube (because of ‎trauma or malignancy) were randomized into two groups; control (removal of chest tube ‎when drainage reached to 150 ml/day) and trial (removal of chest tube at the level of ‎‎200 ml/day). All patients received standard care during hospital admission and a follow-‎up visit after 7days of discharge from hospital. Patients were then compared in terms of ‎major clinical outcomes using chi-squared and t-test. Results: From the total of 138 patients, 70 and 68 patients were randomized to control ‎‎(G150) and trial (G200) group, respectively. Baseline characteristics were comparable ‎between the two groups. Although the trial group had a shorter mean for length of ‎hospital stay (LOS) (4.1 compared to 4.8, p=0.04), their differences in drainage time ‎did not reach to the level of statistical significance (p=0.1). Analysis of data showed no ‎statistically significant differences between the rate of radiological reaccumulation, ‎thoracentesis and decrease in pulmonary sounds (auscultatory), one week after ‎discharge from hospital.‎‏ ‏Conclusions: Compared to a daily volume drainage of 150 ml, removal of chest tube ‎when there is 200 ml/day is safe and will even result in a shorter hospital stay. This in ‎turn leads to a lower cost.

The reliability of self-reporting chronic diseases: how reliable is the result of population-based cohort studies

Objectives: To evaluate the reliability of self-reporting chronic diseases in the baseline data of the Ravansar Non-Communicable Diseases (RaNCD) cohort study in Kermanshah province, western Iran.Methods: The study was conducted in RaNCD cohort study. To assess the reliability of self-report of chronic disease, a random sample of 202 participants were asked about some of chronic conditions 30-35 days (mean=32) after recruitment.Results: A range of kappa agreement between 39.52-100%, which the lower statistics was for hypertension and hepatitis and the higher one for cancer, cardiac ischemic, and diabetes.Conclusion: The self-report of chronic diseases was highly reliable. Therefore self-reporting data for some conditions can be used in situations where the validity is acceptable

Effects of Air-Injection Pressure on Airflow Pattern of Air Sparging

Air sparging is a remediation technology for treating soil/groundwater contaminated with volatile organic compounds (VOCs). VOC removal during air sparging is rendered less effective because of the random formation of air channels, creating preferential paths for airflow, thus limiting remediation to these channels, referred to as a zone of influence (ZOI). Pulsation is a popular method used to improve the effectiveness of air sparging through cyclic operation, with the hope that air channels would form elsewhere. Pulsation makes air sparging more time-consuming. This paper studies the effects of one cycle of pulsation and air pressure on the airflow pattern and presents a laboratory study that investigated the effects of initial and further increases in the injected air’s pressure on the airflow pattern within a glass-bead medium used as a medium analogous to the soil. Digital images of airflow patterns were collected; these images show a larger radius of influence (ROI) and ZOI due to the initial air-pressure increase, particularly when a higher overburden pressure (i.e. the stress due to the partially saturated layer on top of the saturated soil-simulant layer) exists above the water-saturated zone. Further air-pressure increases seem to have no measurable effect on the ROI and the shape of the ZOI

Electromagnetically Induced Transport in Water for Geoenvironmental Applications

Air sparging is a popular soil remediation technique that enables the removal of contaminants through diffusing air into soil. The removal process is, however, slow. The goal of this work is to study the effect of electromagnetic (EM) waves —with minimal heat generation— on transport mechanisms such as diffusion, in order to improve airflow or contaminant transport in order to expedite the cleanup process using air sparging or similar technologies. This effect is studied through an experimental setup that examines the diffusion of a nonreactive dye in water under EM waves at a range of frequencies (50-200 MHz). The electric field was simulated using COMSOL Multiphysics for better three-dimensional (3D) visualization and analysis and then validated using the experimental measurements. A dielectrophoretic study was then performed using the simulated electric field. Various dye flows under EM stimulation at different frequencies were compared. At 65 MHz and 76 MHz, the dye flow was in the direction of the dielectrophoretic forces, which are believed to be the governing mechanism for the EM-stimulated dye transport

Laboratory Study of the Effect of Electromagnetic Waves on Airflow during Air Sparging

Air sparging is a technique that uses the injection of a gas (e.g., air, oxygen) into the subsurface to remediate saturated soils and groundwater contaminated with volatile organic compounds (VOCs). Contaminant-removal efficiency and air-sparging performance are highly dependent on the pattern and type of airflow. Airflow, however, suffers from air channel formation (i.e., preferential paths for airflow), limiting remediation to smaller contaminated zones. This paper presents the results of experimental work investigating the possibility of controlling and improving airflow patterns through a saturated glass-bead medium using electromagnetic (EM) waves to enhance air sparging. The test setup consists of a resonant cavity made of an acrylic tank covered with transparent, electrically conductive films. Experimental measurement of the electric field component of EM waves is performed at different frequencies. Airflow pattern is also studied at different air-injection pressure levels with/without EM stimulation. The zone of influence (ZOI) during air sparging is monitored using digital imaging. A quantitative approach is then taken to correlate the characteristics of EM waves and airflow patterns

Study of Mechanisms Governing Electromagnetic Alteration of Hydraulic Conductivity of Soils

Hydraulic conductivity is a measure of the rate at which water flows through porous media. Because of the dipole properties of water molecules, electric field can affect hydraulic conductivity. In this study, the effect of radio-frequency (RF) waves on hydraulic conductivity is investigated. This is important both for the geophysical measurement of hydraulic conductivity as well as remediation using electromagnetic waves. Bentonite clay and sandy samples are tested in rigid-wall, cylindrical permeameters and stimulated using a CPVC-cased monopole antenna vertically centered in the permeameters. The permeameters are encased within RF cavities constructed of aluminum mesh in order to prevent interference from the outside and to confine the RF wave to the medium. Falling-head and constant-head tests are performed to measure the hydraulic conductivity of the clayey and sandy soil samples, respectively. The results show a correlation between the change in the hydraulic conductivity and various characteristics of the RF stimulation. The change is, however, different for sandy and clayey soils

MATLAB in electrochemistry: A review

International audienceMATLAB (MATrix LABoratory) is a multi-paradigm numerical computing environment and fourth-generation programming language. MATLAB allows matrix manipulations, plotting of functions and data, implementation of algorithms, creation of user interfaces and interfacing with programs written in other languages, including C, C ++ , Java, Fortran and Python. Electrochemistry is a branch of chemistry that studies the relationship between electricity, as a measurable and quantitative phenomenon, and identifiable chemical change, with either electricity considered an outcome of a particular chemical change or vice versa. MATLAB has obtained a wide range of applications in different fields of science and electrochemists are also using it for solving their problems which can help them to obtain more quantitative and qualitative information about systems under their studies. In this review, we are going to cast a look on different applications of MATLAB in electrochemistry and for each section, a number of selected articles published in the literature will be discussed and finally, the results will be summarized and concluded

What explains socioeconomic inequalities in dental flossing? Cross-sectional results from the RaNCD cohort study

Introduction: The magnitude of or determinants underlying socioeconomic inequalities in the use of dental floss is poorly understood in Iran. This study aimed to measure and decompose socioeconomic inequalities in dental flossing in Ravansar, Iran. Methods: This cross-sectional study used data of 10002 individuals aged 35-65 years obtained from the Ravansar Non-communicable Disease (RaNCD) cohort study located in Kermanshah province, west of Iran.  Socioeconomic status was measured through an asset-based method and principal component analysis was carried out to determine the socioeconomic status (SES). The concentration index and curve were used to measure socioeconomic inequality in dental flossing. Decomposition analysis was also used to determine the main determinants that contribute to inequalities in dental flossing. Findings: Of 10,002 participants, 11.74% were found to use dental floss. The normalized CI for use of dental floss was 0.327 in the entire population, 0.323 in females and 0.329 in males, indicating that the use of dental floss is more concentrated among high-SES individuals. The decomposition analysis indicated that SES (50.58%) and level of education (44.90%) respectively contributed the most to this inequality. Place of residence (10.55%) and age group (2.7%) were the next main contributors, respectively. Conclusion: There are a low prevalence and a relatively high degree of pro-rich socioeconomic-related inequality in dental flossing among Iranian adults. Socioeconomic status, level of education and place of residence contributed the most to the observed inequalities in dental flossing. Policy interventions should consider these factors to reduce inequality in the use of dental floss and increase the prevalence of dental flossing. &nbsp