Cryoablation of cardiac arrhythmias

This thesis evaluates the safety and efficacy of cryoablation in supraventricular tachyarrhythmias. In Study I, the acute and long-term outcome of cryoablation therapy of typical atrioventricular nodal reentrant tachycardia (AVNRT) was studied in a large series of patients (n=312). Acute procedural success in AVNRT with cryoablation was achieved in 99% of patients with a recurrence rate of 5.8% during a mean follow-up period of 22 months, which is similar to the expected outcome after radiofrequency ablation (RF). There were no long-term complications related to the use of cryoablation. Additionally, it was shown that further reduction of the recurrence rate may be achieved by using the endpoint of complete slow pathway elimination compared with residual slow pathway conduction. In Study II the clinical usefulness of cryoenergy for the ablation of perinodal atrioventricular reentrant tachycardia (AVRT) was investigated. Cryomapping of substrates adjacent to the AV-node may improve safety of the procedure. Acute procedural success with cryoablation in superoparaseptal and septal accessory pathways was achieved in 96% of the patients with a recurrence rate of 27% during a median follow-up of 33 months. The total success rate was 89% after a second cryoablation. Thus, acute and long-term results were similar to those reported for RF but without any complications related to the conducting system. In Study III the safety and efficacy of cryoablation of atrial tachycardia (AT) with high risk of ablation-related injuries was evaluated. AT foci originated from the para-hisian area, the vicinity of the sinus node, and the crista terminalis adjacent to the phrenic nerve were studied. Acute procedural success was achieved in 96% of patients with a recurrence rate of 12% during a mean follow-up period of 16 months. The total success rate after a second cryoablation was 92%, which is similar to that reported for RF ablation but without any permanent complications. In Study IV cryoablation was compared to RF ablation for the treatment of cavotricuspid isthmusdependent atrial flutter with emphasis on clinical success, safety, and procedure-related pain. The acute ablation success was 95% in the RF group and 92% in the cryoablation group (NS). The long-term success after six-month of follow-up was 92% for RF and 86% for cryoablation (NS). RF ablation caused significantly more pain compared to cryoablation both in terms of average and peak pain perception. In conclusion, cryoablation of AVNRT, of high risk AVRT, and of AT are safe and effective alternatives to RF ablation without causing any permanent complication related to the conducting system and the phrenic nerve. Moreover, cryoablation of isthmus-dependent atrial flutter is not inferior to RF but with less procedure-related pain

Big Data Analysis application in the renewable energy market: wind power

Entre as enerxías renovables, a enerxía eólica e unha das tecnoloxías mundiais de rápido crecemento. Non obstante, esta incerteza debería minimizarse para programar e xestionar mellor os activos de xeración tradicionais para compensar a falta de electricidade nas redes electricas. A aparición de técnicas baseadas en datos ou aprendizaxe automática deu a capacidade de proporcionar predicións espaciais e temporais de alta resolución da velocidade e potencia do vento. Neste traballo desenvólvense tres modelos diferentes de ANN, abordando tres grandes problemas na predición de series de datos con esta técnica: garantía de calidade de datos e imputación de datos non válidos, asignación de hiperparámetros e selección de funcións. Os modelos desenvolvidos baséanse en técnicas de agrupación, optimización e procesamento de sinais para proporcionar predicións de velocidade e potencia do vento a curto e medio prazo (de minutos a horas)

The Extraction of Affecting Processes on the Management of Health, Safety and Environment (Case Study Mapna Group MD 2 in 2016)

Nowadays, the change and dynamism of organizations are the basic principles; therefore, managers should modify the goals, plans and work procedures so that they can be compatible with the environment condition. The management of HSE is not excepted from this principle. The aim of this study was to evaluate the processes affecting HSE. This study was a cross-sectional and applied study using the review of relevant documentation, interviews and brainstorming with experts, and the reviews of Best Practice to identify the HSE's processes. After checking the HSE activities, the 5 processes of HSE training, managing the risks, events, emergencies and contractors and any changes in the other processes of the organization were also suggested. The results showed that a process approaching the form of an intervention programed can be provided in order to have a better interaction between the HSE activities and organizations processes and workplace health promotion for the HSE activities

Perspectives of Nurses on Organizational Culture

Background & Objective: Hospitals and healthcare centers, like any other organizations, have some common norms and beliefs called as organizational culture. Organizational culture plays a key role in organization's and staffs' performances. Nurses' perspectives on the organizational culture affect the way they play their role in. This study aimed to investigate the role of organizational culture from perspectives of nurses working in selected hospitals at Tehran University of Medical Sciences. Methods & Materials: In this cross-sectional study, 230 nurses working in different wards of selected hospitals of Tehran University of Medical Sciences were recruited to the study. Data were collected using a demographic characteristics checklist as well as the nurse and organizational culture questionnaire extracted from the Robbins criteria. Data were analyzed using descriptive statistical indexes, independent t-test, Pearson correlation coefficient and regression in the SPSS v.17. Results: Results showed that the existing organizational culture in the selected hospitals was in a moderately good level from nurses' perspectives. From the scores obtained for various dimensions of the organizational culture, the highest and lowest scores were for control (44.2%) and conflict tolerance (31.8%), respectively. Conclusion: The level of the organizational culture from the nurses' perspectives might lead them to decrease the quality of their performance. Optimizing the organizational culture can improve nurses' performance and motivate them to increase their quality of work. &nbsp

The Extraction of Affecting Processes on the Management of Health, Safety and Environment (Case Study Mapna Group MD 2 in 2016)

Nowadays, the change and dynamism of organizations are the basic principles; therefore, managers should modify the goals, plans and work procedures so that they can be compatible with the environment condition. The management of HSE is not excepted from this principle. The aim of this study was to evaluate the processes affecting HSE. This study was a cross-sectional and applied study using the review of relevant documentation, interviews and brainstorming with experts, and the reviews of Best Practice to identify the HSE's processes. After checking the HSE activities, the 5 processes of HSE training, managing the risks, events, emergencies and contractors and any changes in the other processes of the organization were also suggested. The results showed that a process approaching the form of an intervention programed can be provided in order to have a better interaction between the HSE activities and organizations processes and workplace health promotion for the HSE activities

Protective effect of Malva sylvestris L. extract in ischemia-reperfusion induced acute kidney and remote liver injury.

Mallow (Malva sylvestris L.) has had medicinal and therapeutic uses in addition to its oral consumption. The present study was conducted to examine the protective effect of Malva sylvestris L. extract on ischemia-reperfusion-induced kidney injury and remote organ injuries in the liver. Before ischemia-reperfusion, rats in the different groups received intraperitoneal normal saline or mallow extract at the doses of 200, 400 or 600 mg/kg of body weight. After 30-minutes of bilateral renal ischemia followed by 24-hours of reperfusion, tissue damage in the kidney and liver samples were determined through studying H&E-stained slides under a light microscope. The degree of leukocyte infiltration and tissue mRNA expressions of TNF- and ICAM-1 were then measured to examine the degree of renal inflammation. The renal tissue MDA and FRAP levels were measured for determining the amount of oxidative stress. Plasma concentrations of creatinine, urea, ALT and ALP were also measured. Ischemia-reperfusion led to a significant increase in plasma concentrations of creatinine, urea, ALT and ALP, and renal tissue MDA, and a significant decrease in renal tissue FRAP. The expression of pro-inflammatory factors in the kidney tissue, the level of leukocyte infiltration and the amount of tissue damage in the kidney and liver also increased. Pretreatment by mallow extract led to a significant improvement in all the variables measured. The 200- and 400-mg doses yielded better results in most parameters compared to the 600-mg dose. The findings showed that mallow extract protects the kidney against ischemia-reperfusion and reduces remote organ injury in the liver

Factors Influencing Unsafe Behaviors and Accidents on Construction Sites: A Review

Objective. Construction is a hazardous occupation due to the unique nature of activities involved and the repetitiveness of several field behaviors. The aim of this methodological and theoretical review is to explore the empirical factors influencing unsafe behaviors and accidents on construction sites. Methods. In this work, results and findings from 56 related previous studies were investigated. These studies were categorized based on their design, type, methods of data collection, analytical methods, variables, and key findings. A qualitative content analysis procedure was used to extract variables, themes, and factors. In addition, all studies were reviewed to determine the quality rating and to evaluate the strength of provided evidence. Results. The content analysis identified 8 main categories: (a) society, (b) organization, (c) project management, (d) supervision, (e) contractor, (f) site condition, (g) work group, and (h) individual characteristics. The review highlighted the importance of more distal factors, e.g., society and organization, and project management, that may contribute to reducing the likelihood of unsafe behaviors and accidents through the promotion of site condition and individual features (as proximal factors). Conclusion. Further research is necessary to provide a better understanding of the links between unsafe behavior theories and empirical findings, challenge theoretical assumptions, develop new applied theories, and make stronger recommendations

Representing histopathologic alterations in liver tissue of rats that underwent sham (A), renal ischemia/reperfusion and pretreatment with normal saline (B), or malva silvestris extract at 200, 400, or 600 mg/kg (C-E).

<p>(Haematoxylin-Eosin, 400x).</p

Plasma creatinine (A) and urea (B) levels in rats that underwent renal ischemia/reperfusion (I/R), pretreated with normal saline (I/R), or malva silvestris extract at 200, 400, or 600 mg/kg (I/R + M) compared to the sham group.

<p>Data is presented as mean ± SE (n = 7 in each group).</p> <p>* P<0.05 in comparison with the sham group</p> <p>** P<0.01, *** P<0.001 in comparison with the sham group</p> <p>‡‡ P < 0.01, ‡‡‡ P < 0.001 in comparison with the I/R group</p> <p>†† P < 0.01 in comparison with the I/R + M200 group.</p