50 research outputs found

    Salt Loading from Efflorescence and Suspended Sediments in the Price River Basin

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    Salinity control is a major component of water management in arid climates and irrigated areas and one of particular concern in the Colorado River Basin. The alts enter the water as it flows over land or moves through the soil or geologic formations. The principal salt collection processes are 1) dissolution from the soil surface during runoff events, 2) transpiration of soil water leaving salt residuals, 3) efflorescence left by evaporating seepage and then dissolved by subsequent runoff, 4) dissolution with weathering of fixed bed channels, 5) salts released by sediments entering the channel from sheet, gulley, and bank erosion, and 6) deep percolation through saline aquifer reaching the stream as base flow. This study examined processes 3 and 5. Salt efflorescence was examined by field observation and instrumentation, laboratory experiments, and mathematical modeling. The field data showed near saturation conditions of sodium sulfate waters below crusts of densities between 0.14 and 0.36 g/cm^2 and which formed over abouta 10-day period following channel cleaning by storm runoff. Laboratory data on salt crusting in soil columns were also used in developing a model which when applied to the Price River Basin estimated that no more than 7.5 percent of the total salt loading comes from salt efflorescence being carried away in the stream flow. The conditions favorable to the accumulation of salt efflorescence are highly saline water just below the soil surface and a source of heat for vaporizing the water. Salt release from suspended sediments was studied by laboratory experimentation with sediment material obtained from various locations in the Price River Basin. The Buckinham Pi Theorem was employed to derive relationships expressing the EC of a sediment water system as a function o fthe controlling factors. The results were presented in two salt release equations, one excluding the effect of initial EC and the other providing for initially saline solutions. The salt release equations were incorporated into an adapted version of the Watershed Erosion and Sediment Transport (WEST) model and applied to a small tributary of Coal Creek. Extrapolation to the entire Price River Basin led to an estimate that about 0.50 percent of the total annual salt load is released from suspened sediments. This study concludes that surface salt sources produce a relatvely small fraction of the total loading. Future studies need to go underground. They need to quantify and examine the flow lines of water movement from mountain source and valley floow recharge areas to points of emergence as base flow in the larger stream channels. They need to investigate the aquifers and their soluble salt content

    Synthesis and Characterization of Silicate Calcium Phosphate Bioactive Glass Prepared by Electrospinning Method

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    Ternary (%mol) (64SiO2-31CaO-5P2O5) system of sol-gel derived bioactive glass fibers was prepared by electrospinning method. X-ray Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and nitrogen adsorption test (BET) analyses were performed to investigate the phase and chemical group of the composition, morphology of the surface and specific surface area of the fibers, respectively. SEM observations confirmed that the fibers were nano size. The amorphous nature and the presence of silanol groups in the composition were confirmed by XRD and FTIR, respectively. Apatite formation and biodegradability of the fibers were studied using various analyses after different days of soaking in simulated body fluid (SBF). The results affirmed the presence of apatite layers on the surface of the fibers. Cell culture evaluation indicated that MG-64 human osteoblast-like cells were attached and spread well on the surface. Furthermore, cell viability and cell growth demonstrated that the cells were grown and reproduced well on the fibers

    Factors Affecting the Quality and Quantity of Sleep in Coronary Artery Bypass Graft Patients

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    Introduction: Sleep disturbance is common in patients undergoing Coronary Artery Bypass Graft surgery and has been recognized for more than 30 years. New literature suggests the importance of sleep and rest for restoration, protection and promotion of function and wellbeing of these patients. Because of the importance of the role of nurses in diagnosis and treatment of sleep disorders, this study was conducted to determine possible effective factors on sleep quality and sleep quantity of patients after CABG. Methods: This longitudinal, descriptive and correlational study was conducted on 91 patients admitted to Imam Reza Hospital in Mashad City in 2005-2006. Subjects were selected according to inclusion and exclusion criteria. Data was collected by interview in three stages: 24 hours before surgery, as well as 6 weeks and 10 weeks after surgery. Subjective sleep quality was measured with PSQI and sleep quantity was measured with sleep log. The first two interviews were done at the hospital clinic and the last via telephone. Data was analyzed in SPSS using student T test, Pearson correlation coefficient and General Linear Model. Results: According to Univariable analysis, variables such as age (p=0.03), aorta clamp time (p=0.003), mechanical ventilation time (p=0.01), staying time in hospital (p=0.04) can affect sleep quantity 10 weeks after surgery. Previous history of sleep disorder (p=0.005), diabetes (p=0.02), use of diuretic drugs before surgery (p=0.04) and ACEI drugs after surgery (p=0.01) can affect sleep quality 10 weeks after surgery. Conclusion: Sleep disorder history (p=0.01), use of diuretic drugs before surgery (p=0.04) and sleep quantity 6 weeks after surgery (p=0.01) have been the most effective factors on sleep quality 10 weeks after surgery, whereas quality of life 10 weeks after surgery (p=0.04) has been the most effective factor on sleep quantity 10 weeks after surgery. There is therefore a necessity for presenting approaches in order to eliminate and minimize modifiable factors

    Detection and qualification of optimum antibacterial and cytotoxic activities of silver-doped bioactive glasses

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    This study aims to detect the optimum antibacterial activity of silver-doped bioactive glasses (Ag-BGs) for prevention of post-transplant infections in tissue engineering. The results have shown that the Ag-BG samples had broad-spectrum antibacterial efficacy in an Ag concentration-dependent manner. The 2 Ag-BG had the highest effect during the first 10 min to 72 h. The minimum inhibitory concentration of 2 Ag-BG was estimated to be 2 mg/ml for Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) and 2.66 mg/ml for Staphylococcus aureus (S. aureus). A concentration of 0.5 Ag-BG repressed growth of E. coli after 1 h, but did not have any detectable antibacterial effect for longer periods. Evaluation of the effects of prepared Ag-BG on human osteoblast cells viability showed that 1 and 2 samples changed the cell proliferation rate in masses of more than 3.33 and 2 mg/ml, respectively. Moreover, in a typical manner, the release of Ag ions from the glass structure started immediately, continued steadily and affected bacterial growth when it reached its critical concentration in the medium. This systematic study can illustrate the optimum antibacterial property of the Ag-BG samples in masses of 3.33 and 2 mg/ml for 1 and 2 Ag, respectively, for prevention of post-transplant infections. © The Institution of Engineering and Technology 2015

    Anthropometric indices predicting incident hypertension in an Iranian population: The Isfahan cohort study

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    10.14744/AnatolJCardiol.2019.10594Anatolian Journal of Cardiology22133-4

    Socioeconomic determinants and metabolic syndrome : Results from the Isfahan Healthy Heart Program

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    Introduction: The prevalence of metabolic syndrome (MetS) is increasing in Iran. We assessed the relationship between socioeconomic status (SES) and Mets components in the Iranian population. Materi- als and Methods: The sample for this study comprised a random cross-section of men and women from two province districts who participated in the Isfahan Healthy Heart Program (IHHP) in 2007. Each participant completed a questionnaire, underwent anthropometric testing and blood pressure measurements, and pro- vided a blood sample. Mets was defined based on ATPIII criteria. Several SES dimensions, such as education, occupation, and number of children, as well as home, car, and personal computer ownership, were assessed to determine the participant’s SES. Results: A higher-than-average income, car ownership, owning or renting a private home, and having a computer are increasing towards increment in SES. All MetS components were more prevalent in participants defined as having a lower SES, while low HDL levels were more common in participants having an SES II (P>0.001). A multivariate analysis showed that having the lowest SES (I) increased the risk of MetS by 1.72 [1.44-2.07], whereas subjects having an SES III had a 1.23 [1.04-1.47] lower risk for MetS. Conclusions: The relationship between SES and Mets is due largely to behavioural factors, such as practicing unhealthy eating habits. Given the high prevalence of Mets in Iran, we propose that regular health check-ups may be useful in the early detection of the syndrome and, consequently, in the prevention of its effects. In addition, the early detection of MetS may result in the early diagnosis and prevention of car- diovascular diseases. (www.actabiomedica.it
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