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Background: Investigation of various aspects of care in ostomy patients is of clinical importance, as the level of knowledge and skills of nurses directly influences the quality of patient education and satisfaction with received care. Objectives: The purpose of this study was to determine knowledge of nurses in general surgery wards regarding fecal intestinal ostomies. Methods: This cross-sectional study was performed during year 2015 at teaching hospitals (Ghaem, Imam Reza and Omid hospitals) affiliated to Mashhad University of Medical Sciences, Iran. We used census for sampling, and the study population included all nurses, who were working in intestinal ostomy surgery wards. Inclusion criteria were having an undergraduate degree in nursing and at least one-year work experience at the surgical ward. Data collection tools were a demographic information questionnaire and a researcher-made survey of "assessment of knowledge of nurses in ostomy care". Data were analyzed using SPSS software version 11.5. Results: Overall, 83.9% of participants were female and mean work experience at the surgical ward was 4.23 (SD = 3.73). More than half of the nurses gave incorrect answers to questions related to the use of powders and sprays associated with skin itching and sensitivity (64.3%), and how to care for ostomy with a rod (66.1%). Nurses also showed low and very low levels of knowledge on symptoms and control of obstruction (57.1%), change duration in the size of ostomy (66%), sexual intercourse (57.1%), colostomy complications (51.8%) and ileostomy (57.1%) and authorized or unauthorized activities (50%) as well as how to perform bowel irrigation (75%). Conclusions: According to the results of this study, the knowledge of nurses was not enough to provide primary care for ostomy; thus due to the importance of adequate knowledge and because of needs assessments, it is recommended for nursing managers to conduct retraining courses and other educational approaches for nurses.

The use of gas permeable membranes for bubbleless aeration is of increasing interest due to the energy savings it affords in wastewater treatment applications. However, flow maldistributions are a major factor in the impedance of mass transfer efficiency. In this study, the effect of module configuration on the hydrodynamic conditions and gas transfer properties of various submerged hollow fibre bundles was investigated. Flow patterns and velocity profiles within fibre bundles were predicted numerically using computational fluid dynamics (CFD) and the model was validated by tracer-response experiments. In addition, the effect of fibre spacing and bundle size on the aeration rate of various modules was evaluated experimentally. Previous studies typically base performance evaluations on the liquid inlet velocity or an average velocity, an approach which neglects the effect of geometric features within modules. The use of validated CFD simulations provides more detailed information for performance assessment. It was shown that specific oxygen transfer rates declines significantly with increasing numbers of fibres in a bundle. However, the same trend was not observed when the fibre spacing is increased. A correlation was proposed for the prediction of the overall mass transfer coefficient utilizing the local velocity values obtained from the validated CFD model.

Cylindrical Kresling origami structures are often used in engineering fields due to their axial stretchability, tunable stiffness, and bistability, while their radial closability is rarely mentioned to date. This feature enables a valvelike function, which inspired this study to develop a new origami-based valve. With the unique one-piece structure of origami, the valve requires fewer parts, which can improve its tightness and reduce the cleaning process. These advantages meet the requirements of sanitary valves used in industries such as the pharmaceutical industry. This paper summarizes the geometric definition of the Kresling pattern as developed in previous studies and reveals the similarity of its twisting motion to the widely utilized iris valves. Through this analogy, the Kresling structure’s closability and geometric conditions are characterized. To facilitate the operation of the valve, we optimize the existing structure and create a new crease pattern, RC-ori. This novel design enables an entirely closed state without twisting. In addition, a simplified modeling method is proposed in this paper for the non-rigid foldable cylindrical origami. The relationship between the open area and the unfolded length of the RC-ori structure is explored based on the modeling method with a comparison with nonlinear FEA simulations. Not only limited to valves, the new crease pattern could also be applied to microreactors, drug carriers, samplers, and foldable furniture.

Background: Early childhood caries (ECC) is an aggressive and multifactorial form of dental caries in children, in which the biomarkers of oxidative stress may increase. Objectives: This study aimed to compare the salivary malondialdehyde (MDA) levels in children with early childhood caries (ECC) and caries-free (CF) children. Methods: To this end, 42 ECC children and 42 CF children, aged 4 - 6 years, were randomly selected from the kindergartens of four socio-economically different districts of Isfahan. An unstimulated saliva sample was obtained from children fasting during the past night using the spitting method. In the laboratory, the MDA levels were evaluated spectrophotometrically. An independent-samples t-test was used to examine the differences between the two groups. Results: The mean salivary MDA level was significantly higher in the ECC group than in the CF group (P = 0.01), and there was no significant relationship between salivary MDA and gender (P = 0.44 in the ECC group, P = 0.30 in the CF group). Moreover, no significant relationship was noticed between MDA with decayed, missing, filled teeth (dmft). Conclusions: The findings documented a relationship between ECC and MDA as one of the products of oxidative stress reactions. Accordingly, the MDA level of saliva can be a critical indicator in determining the status of caries in children.