31 research outputs found

    Numerical, Experimental and Analytical Studies on Fluid Flow through a Marsh Funnel

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    This paper presents the application of computational fluid dynamics technique in civil and underground industries to evaluate fluid behaviour in a Marsh funnel. The numerical approach, based on computational fluid dynamics, simulated an incompressible two-phase Newtonian flow by means of the Volume-of-Fluid method. A complementary analytical proposed which provided a quick, field-ready method to assess the fluid field in the Marsh funnel. A supplemental experimental effort evaluated the results obtained from both the analytical calculation and numerical simulation. Results showed that the application of computational fluid dynamics technique gives the desired results in studying fluid flows in civil and underground industries. Proposed analytical solution is also capable of accurately predicting the fluid flow and thus can complement the experimental and numerical approaches. Further, the proposed analytical approach can be an alternative method for faster evaluation of fluid, although it needs to be calibrated with either the numerical or the experimental studies

    A systematic review of operating room ventilation

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    Ventilation systems are the primary way of eliminating airborne pathogenic particles in an operating room (OR). However, such systems can be complex due to factors such as different surgical instruments, diverse room sizes, various staff counts, types of clothing used, different surgical types and duration, medications, and patient conditions. OR ventilation should provide a thermally comfortable environment for the surgical staff team members while preventing the patient from suffering from any extreme hypothermia. Many technical, logistical, and ethical implications need to be considered in the early stage of designing a ventilation system for an OR. Years of research and a significant number of publications have highlighted the controversy and disagreement among infection specialists, design engineers, and ventilation experts in this context. This review article aims to provide a good understanding of OR ventilation systems in the context of air quality and infection control from existing research and provide multidimensional insights for appropriate design and operation of the OR. To this end, we have conducted a systematic review of the literature, covering 253 articles in this context. Systematic review and meta-analyses were used to map the evidence and identify research gaps in the existing clinical, practical, and engineering knowledge. The present study is categorized into six research focuses: ventilation system, thermal comfort, staff work practice and obstacles, door operation and passage, air cleaning technology, emission rate, and clothing systems. In the conclusion, we summarize the key limitations of the existing studies and insights for future research direction

    Apoptosis of Human Lymphocytes after Exposure to Hydatid Fluid

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    Background: Modulation of the immune response is an important strategy by which establish­ment and growth of hydatid cyst in the internal organs of human is warranted. Induction of apop­tosis in the lymphocytes might be a considerable component. This study was designed to evaluate apoptotic impact of hydatid fluid (HF) on human lymphocytes.Methods: Human lymphocytes were treated with hydatid fluid. After 6 hours of exposure, cas­pase-3 activity, the central enzyme of apoptosis cascade, was measured by fluorometric assay in the HF-treated lymphocytes and control cells. In addition, the expression of Bax (a pro-apoptotic protein) and Bcl-2 (an anti-apoptotic protein) mRNA was assessed by RT-PCR after 12 hours of exposure.Results: Both the ratio of Bax/Bcl-2 mRNA expression and Caspase-3 activity were higher in the HF-treated lymphocytes relative to the control group.Conclusion: Apoptosis could be as a possible mechanism by which Echinococcus granulosus overwhelms host defenses

    Clinical value of IS6110-based loop-mediated isothermal amplification for detection of Mycobacterium tuberculosis complex in respiratory specimens

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    OBJECTIVES: A fundamental to global tuberculosis (TB) control is timely and accurate diagnosis of infectious cases of the disease. Among various methods, techniques based on nucleic acid amplification are the ones with promising prospects. The present study evaluates the diagnostic value of the recently developed IS6110-based loop-mediated isothermal amplification (LAMP) for detection of Mycobacterium tuberculosis complex (MTBC) in sputum specimens. METHODS: In this cross-sectional study (2008-2009), IS6110-LAMP was evaluated on 101 sputum specimens from 93 highly suspected TB patients and compared to Amplicor MTB test and in-house IS6110-PCR and -nested PCR assays. Culture results or clinical recovery following anti-TB therapy was considered as a reference to prove the TB cases. RESULTS: The overall sensitivity of IS6110-LAMP, Amplicor, nPCR, and PCR were respectively 89.6% (69/77 specimens; 95% confidence interval [CI], 80.5-95.4%), 76.6% (59/77 specimens; CI, 65.6-85.5%), 79.2% (61/77 specimens; CI, 68.5-87.6%) and 59.7% (46/77 specimens; CI, 47.9-70.8%). The specificity and positive predictive value (PPV) were 100% for all the tests, and the negative predictive value (NPV) of IS6110-LAMP, Amplicor, nPCR, and PCR were respectively 75%, 57.1%, 60%, and 43.6%. There was an excellent overall agreement between LAMP and nPCR (k 0.828), and between LAMP and Amplicor (k 0.746), in addition to a better tolerance of IS6110-LAMP to inhibitors present in clinical specimens. CONCLUSION: The better diagnostic performance of IS6110-LAMP compared to Amplicor (p = 0.009), nPCR (p = 0.013) and PCR (p &lt; 0.0001) besides its rapidity, simplicity, and cost-effectiveness makes it a valuable method for the detection of MTBC in clinical samples, particularly in resource-limited settings</p

    Thymectomy for Nonthymomatous Myasthenia Gravis: Comparison of Video-Assisted Thoracoscopic and Transsternal Thymectomy

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    Objective: Thymectomy considered as a standard procedure in treatment of all the steps of myasthenia gravis. Video-assisted thoracoscopic surgery (VATS) thymectomy is one of the minimally invasive procedures that because of the short duration of hospitalization, less postoperative pain, and scar after surgery, nowadays it is replaced the traditional methods of surgery for patients with myasthenia gravis, but there are still differences and concerns. The aim of this study was to compare outcomes of two different techniques of surgery, VATS versus transsternal (TS) in the treatment of myasthenia gravis. Methods: In this pilot study, 42 patients with myasthenia gravis and without a thymus tumor were evaluated based on Myasthenia Gravis Foundation of America classification and drug consumption. Then, they randomly underwent two different techniques of surgery: VATS versus TS. Patients were evaluated based on preoperative and postoperative variables. Results: Duration of intensive care unit stay and hospitalization has been reduced in patients who underwent VATS thymectomy operation technique. In addition, duration of surgical procedure has been reduced significantly in these patients. These patients have less blood loss during surgery compared with TS group. The Myasthenia Gravis Foundation of America postoperative status in VATS thymectomy revealed that the number of patients with complete stable remission was higher and number of persons remained unchanged was lower in this group. Conclusions: VATS thymectomy is a safe and appropriate approach comparing with traditional methods such as TS thymectomy for patients with myasthenia gravis. This method has better results after surgery and can be used as a minimally invasive alternative method instead of TS thymectomy. Copyright © 2018 by the International Society for Minimally Invasive Cardiothoracic Surgery

    The range and diversity of providers' viewpoints towards the Iraqi primary health care system: an exploration using Q-methodology.

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    BACKGROUND: The increasingly recognized need for reorganizing the primary health care services in Iraq calls for a comprehensive assessment of the system to better understand its problems and needs for development. As part of such comprehensive assessment and due to the important role of primary health care providers in adopting any change, we ought to explore the range and diversity of viewpoints of primary health care providers towards the Iraqi primary health care system. METHODS: This explorative study was carried out in Erbil governorate, Iraq from May to July 2011. Data were collected from primary health care providers using Q-methodology to elicit subjective viewpoints and identify shared patterns among individuals. Forty primary health care providers representing eight primary health care centers sorted 41 statements reflecting different aspects of the Iraqi primary health care system into a distribution on a scale of nine from "disagree most" to "agree most". By-person factor analysis was used to derive latent viewpoints through centroid factor extraction and varimax rotation of factors. RESULTS: Analysis of the participants' Q-sorts resulted in four distinct viewpoints among primary health care providers toward the current primary health care system. One factor emphasized positive aspects of the current primary health care system that is content with the current primary health care system. The other three factors highlighted the negative aspects and they included (i) professionally-centered viewpoint, (ii) comprehensive perception and problem-based solutions and (iii) critical to leadership/governance aspects of the system. CONCLUSIONS: This study revealed diverse viewpoints of primary health care providers toward the current Iraqi primary health care system and recognized the particular issues related to each viewpoint. The findings can contribute to a better understanding of health policy makers and primary health care managers concerning the problems facing the primary health care system that might contribute to change in the management of this system
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