431 research outputs found

    Endoscopy in Nasopharyngeal Adenoid Surgery

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    The Effectiveness of Acceptance and Commitment Therapy Based on the Handicraft in Reducing Post-Traumatic Stress Disorder among Hearing Impaired University Students

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    The present study aimed to assess the effectiveness of Acceptance and Commitment Therapy (ACT) based on the use of handicrafts in reducing symptoms of Post-Traumatic Stress Disorder (PTSD) among university students with hearing impairments. A total of 12 hearing impaired students were randomly assigned to either the experimental group (n=6, M=19.47, SD=3.55) or the control group (n=6, M=19.47, SD=3.55). Participants in the experimental group underwent fifteen sessions of group-based ACT using handicrafts. The researchers measured PTSD symptoms before, immediately, after, and two months after the therapy sessions. The findings revealed that ACT based on the use of handicrafts effectively reduced symptoms of PTSD in the experimental group on the post-test and follow-up assessments. These results indicate that ACT based on the use of handicrafts may be a valuable approach in treating individuals with PTSD

    OPEN CIRCUIT HEAT EXCHANGER DYNAMICS DURING FLOW REDUCTION TRANSIENT IN THEIR SECONDARY LOOPS

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    An experimental and theoretical analysis was conducted for simulation of open circuit cross flow heat exchanger dynamics during flow reduction transient in their secondary loops. Finite difference mathematical model was prepared to cover the heat transfer mechanism between the hot water in the primary circuit and the cold water in the secondary circuit during transient course. This model takes under consideration the effect of water heat up in the secondary circuit due to step reduction of its flow on the physical and thermal properties linked to the parameters that are used for calculation of heat transfer coefficients on both sides of their tubes. Computer program was prepared for calculation purposes which cover all the variables that affect such type of transient mechanisms. The effect of the power density in the primary circuit and the water flow reduction percentage on the average temperature build up of the water in the primary circuit was investigated. The elapsed time required for the primary circuit average temperature to reach a steady state value was also calculated. These calculations were supported with experimental measurements conducted on a standard cross flow heat exchanger apparatus. The experimental results were compared with the theoretical results for certain power density value at different flow reduction percentages which show a reliable agreement. This relative agreement was necessary to consider the mathematical model with certain assurance for calculating transient parameters for higher power densities that are out of apparatus ranges. The results proved that water average temperature build up in the primary circuit has sharp tendency when the percentage of flow reduction in the secondary circuit reach 25% of its nominal values

    The minimally-invasive thyroidectomy incision: a histological analysis.

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    BACKGROUND: Minimally invasive thyroidectomy (MIT) has gained popularity in the surgical management of benign and malignant pathology of the thyroid. One of the main benefits of utilizing this technique is the use of smaller incisions resulting in increased cosmetic satisfaction. Unfortunately, the retraction required for adequate exposure during MIT may lead to skin damage, impaired wound healing and poor cosmetic outcomes. Some have proposed that excising incision edges prior to closure may improve cosmesis. A review of the literature does not reveal any histologic evidence to support this technique. MATERIAL/METHODS: In this prospective observational study, nine subjects undergoing MIT were identified. Both the superior and inferior skin edges were excised and labeled for orientation. Specimens were sent for hematoxylin and eosin staining and histologic analysis by a staff pathologist. RESULTS: All specimens showed no significant findings such as damage to the architecture of the dermis, acute inflammation, edema or evidence of hemorrhage. Focal blood vessel ectasia within the dermis was identified in three of nine subjects. CONCLUSIONS: Our findings do not yield a histological basis supporting the routine trimming of incisions during MIT. Although no significant findings were noted histologically, further studies are warranted to investigate the long-term cosmetic outcome of MIT incisions

    Simulation and Experimental Investigation of Performance and Flow Behavior for Steam Ejector Refrigeration System

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    The ejector refrigeration system is a desirable choice to reduce energy consumption. A Computational Fluid Dynamics CFD simulation using the ANSYS package was performed to investigate the flow inside the ejector and determine the performance of a small-scale steam ejector. The experimental results showed that at the nozzle throat diameter of 2.6 mm and the evaporator temperature of 10oC, increasing boiler temperature from 110oC to 140oC decreases the entrainment ratio by 66.25%. At the boiler temperature of 120oC, increasing the evaporator temperature from 7.5 to 15 oC increases the entrainment ratio by 65.57%. While at the boiler temperature of 120oC and the evaporator temperature of 10oC, increasing the nozzle throat diameter from 2.4 to 2.8 mm decreases the entrainment ratio by 40%. The numerical results showed that reducing the condenser back pressure or increasing the primary fluid temperature, secondary fluid temperature, and nozzle throat diameter moves the second shock waves in the downstream direction. It could be concluded that the second shock series position detects the ejector operation mode. The ejector runs in critical mode if the second shock series position is close to the diffuser. In contrast, if the second shock series position moves toward the upstream, the ejector runs in subcritical mode

    Experimental Study of Power Increase Transient in Heat Generation Systems Simulated By Immersed Heat Source

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    Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulus and solved by using Laplace method to determine the variation of bulk water temperature. The experimental investigation included a set of experiments carried out to investigate the temperature variation along the heat source for power increase transient of (5%, 10%, 15% and 20%) of its nominal value during and after reaching the steady state condition. Estimation of the boiling safety factor is predicted and compared with the theoretical values. Reliable agreement between experimental and theoretical approaches is reached. The later showed that the elapsed time required for the clad surface temperature to reach its steady state values after each transient is less than that related to bulk water temperature. New correlation for prediction of critical heat flux, CHF based on inlet water temperature and water mass flux are investigated and compared with CHF correlations obtained from previous researches. Specific recommendations concerned with preventive measured required to eliminate the effect of boiling crisis are concluded based on theoretical and experimental results related to transients setting times obtained from each case study

    Rewiring coral: Anthropogenic nutrients shift diverse coral–symbiont nutrient and carbon interactions toward symbiotic algal dominance

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    Improving coral reef conservation requires heightened understanding of the mechanisms by which coral cope with changing environmental conditions to maintain optimal health. We used a long‐term (10 month) in situ experiment with two phylogenetically diverse scleractinians (Acropora palmata and Porites porites) to test how coral–symbiotic algal interactions changed under real‐world conditions that were a priori expected to be beneficial (fish‐mediated nutrients) and to be harmful, but non‐lethal, for coral (fish + anthropogenic nutrients). Analyzing nine response variables of nutrient stoichiometry and stable isotopes per coral fragment, we found that nutrients from fish positively affected coral growth, and moderate doses of anthropogenic nutrients had no additional effects. While growing, coral maintained homeostasis in their nutrient pools, showing tolerance to the different nutrient regimes. Nonetheless, structural equation models revealed more nuanced relationships, showing that anthropogenic nutrients reduced the diversity of coral–symbiotic algal interactions and caused nutrient and carbon flow to be dominated by the symbiont. Our findings show that nutrient and carbon pathways are fundamentally “rewired” under anthropogenic nutrient regimes in ways that could increase corals’ susceptibility to further stressors. We hypothesize that our experiment captured coral in a previously unrecognized transition state between mutualism and antagonism. These findings highlight a notable parallel between how anthropogenic nutrients promote symbiont dominance with the holobiont, and how they promote macroalgal dominance at the coral reef scale. Our findings suggest more realistic experimental conditions, including studies across gradients of anthropogenic nutrient enrichment as well as the incorporation of varied nutrient and energy pathways, may facilitate conservation efforts to mitigate coral loss.We provide a long‐term field experiment to test the implications of different nutrient sources, fish excretion and moderate levels of anthropogenic nutrients, for coral health and coral–symbiont interactions. Our study identifies a potentially novel "transition state" whereby despite maintaining high growth rates and creating no apparent negative external effects, anthropogenic nutrient enrichment drives coral–algal interactions to be dominated by the algal symbiont—that is, increased prominence of energy and nutrient flow from the algal symbiont under conditions of Fish + anthropogenic nutrients (NPK) in the figure. We hypothesize that this “rewiring” of the coral–symbiont interactions may render the coral more vulnerable to additional stressors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162733/2/gcb15230_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162733/1/gcb15230.pd

    The optimal succinylcholine dose for intubating emergency patients: retrospective comparative study

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    Background : Succinylcholine remains the drug of choice for satisfactory rapid-sequence tracheal intubation. It is not clear from the literature why the 1 mg/kg dose of succinylcholine has been traditionally used. The effective dose (ED95) of succinylcholine is less than 0.3 mg/kg. The dose of 1 mg/kg represents 3.5 to 4 times the ED95. Objectives : To compare the effect of the traditionally used 1 mg/kg of succinylcholine with lower doses of 0.6 mg/kg and 0.45 mg/kg on intubation condition regarding the onset time, duration of action, duration of abdominal fasciculation, and the intubation grading. Methods : This retrospective comparative study was carried into three groups of ASA III & IV (American Society of Anesthesiologist's Physical Status III and IV) non-prepared emergency patients who were intubated at emergency department of Hamad General Hospital, Doha, Qatar during January 1st 2007 to August 31, 2010. The Institutional Research Board (IRB) approval was obtained. This study was limited to 88 patients who received fentanyl 1 µg/kg followed by etomidate 0.3 mg/kg intravenously as induction agents and succinylcholine as a muscle relaxant agent in doses of 0.45 mg/kg, 0.6 mg/kg, or 1 mg/kg. Results : Increasing the succinylcholine dosage shortened the onset time, prolonged the duration of action, and prolonged the duration of abdominal fasciculation significantly (P<.001). Tracheal intubation was 100% successful in the three groups of patients. Conclusion : Succinylcholine dose of 0.45 mg/kg provides an optimal intubation condition in ASA III & IV emergency non-prepared patients. Duration of action of succinylcholine is dose dependent; reducing the dose allows a more rapid return of spontaneous respiration and airway reflexes

    Decision aid on radioactive iodine treatment for early stage papillary thyroid cancer - a randomized controlled trial

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    Abstract Background Patients with early stage papillary thyroid carcinoma (PTC), are faced with the decision to either to accept or reject adjuvant radioactive iodine (RAI) treatment after thryroidectomy. This decision is often difficult because of conflicting reports of RAI treatment benefit and medical evidence uncertainty due to the lack of long-term randomized controlled trials. Methods We report the protocol for a parallel, 2-arm, randomized trial comparing an intervention group exposed to a computerized decision aid (DA) relative to a control group receiving usual care. The DA explains the options of adjuvant radioactive iodine or no adjuvant radioactive iodine, as well as associated potential benefits, risks, and follow-up implications. Potentially eligible adult PTC patient participants will include: English-speaking individuals who have had recent thyroidectomy, and whose primary tumor was 1 to 4 cm in diameter, with no known metastases to lymph nodes or distant sites, with no other worrisome features, and who have not received RAI treatment for thyroid cancer. We will measure the effect of the DA on the following patient outcomes: a) knowledge about PTC and RAI treatment, b) decisional conflict, c) decisional regret, d) client satisfaction with information received about RAI treatment, and e) the final decision to accept or reject adjuvant RAI treatment and rationale. Discussion This trial will provide evidence of feasibility and efficacy of the use of a computerized DA in explaining complex issues relating to decision making about adjuvant RAI treatment in early stage PTC. Trial registration Clinical Trials.gov Identifier: NCT0108355
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