Myocardial Infarction in Children

Myocardial infarction (MI) is a clinical condition that develops associated with a sudden reduction or interruption of the blood flow of the vessels supplying the heart for various reasons. The electrocardiographic, echocardiographic and enzymatic diagnostic criteria of MI have been well defined in adults, in children there are some difficulties. Although seen more often in the presence of congenital heart disease (CHD), MI may also be seen in patients without CHD. Unlike atherosclerotic coronary artery disease in adult patients, ischaemia and infarct in children are often associated with coronary artery anomalies and CHD. In addition, congenital prothrombotic diseases, vasculitis, surgical or interventional procedures may also cause ischaemia and infarct. Subendocardial ischaemia, especially aortic stenosis characterised by hypertrophy in the left ventricle is often seen in hypertrophic cardiomyopathy or hypertensive patients. The most important risk factors in neonates and infants are the presence of CHD, coronary artery anomalies and perinatal asfixia. The most frequently seen causes of pediatric myocardial infarction (PMI) are abnormal left coronary artery originating from the pulmonary artery (ALCAPA) and Kawasaki disease. Another often seen cause of PMI is patients who underwent arterial switch operations

PENCERE BOŞLUKLU PERDE DUVARLA GÜÇLENDİRİLMİŞ 1/3 ÖLÇEKLİ BETONARME ÇERÇEVELERİN DAVRANIŞI

Bu deneysel çalışmada, 1/3 ölçekli, tek açıklıklı, iki katlı, 6 adet betonarme çerçeve üretilmiş ve pencere boşluklu veya boşluksuz dolgu duvar ile güçlendirilerek davranışları araştırılmıştır. Bu deney numuneleri depremi benzeştiren tersinir-tekrarlanır yükler altında test edilmiştir. Deney numuneleri Türkiye’deki betonarme yapılarda çoğunlukla gözlemlenen eksiklikleri yansıtacak şekilde üretilmiştir. İlk deney numunesi güçlendirme uygulaması yapılmamış referans numunedir. Diğer numuneler ise farklı pencere boşluk oranlarına ve konumuna sahip betonarme dolgu duvarlı numunelerdir. Yapılan deneylerin sonuçları betonarme dolgu duvarların, dayanım, rijitlik ve enerji tüketme üzerindeki etkilerini ortaya koyacak şekilde değerlendirilmiştir.  Deney sonuçları, betonarme dolgu duvarlı numunelerin, referans numuneden daha fazla yatay yük dayanımına, enerji tüketimine ve rijitliğe sahip olduğunu göstermiştir

The Effects of Topiramate Applied to the Nucleus Accumbens Region on Morphine Withdrawal Syndrome

Aim:Nucleus accumbens, one of the nuclei of the basal ganglia, and dopamine, the neurotransmitter play a critical role in opioid dependence and withdrawal. In opioid withdrawal, the importance of neurotransmitters such as glutamate and gamma aminobutyric acid (GABA), as well as dopamine, is known. In this study, we aimed to investigate the effects of local injections of topiramate, an antiepileptic agent affecting GABAergic and glutamatergic pathways, into the nucleus accumbens on withdrawal signs and locomotor activity during naloxone-induced withdrawal in morphine-dependent rats.Materials and Methods:Twenty male Sprague-Dawley rats were divided in topiramate treatment and control groups. All animals received morphine pellets and guide cannulas were placed bilaterally in the nucleus accumbens regions by stereotaxic surgery. On the last day of the experiment, following the bilateral topiramate or saline (control group) microinjections, morphine withdrawal was triggered by naloxone.Results:Topiramate microinjections into the nucleus accumbens region significantly suppressed the signs of naloxone-induced morphine withdrawal such as number of jumpings and weight loss. No significant difference was observed in wet dog shakes, one of the withdrawal signs, after local topiramate treatment. Although topiramate microinjections increased stereotypical activity it did not change locomotor activity behavior such as vertical and ambulatory activity, and total covered distance.Conclusion:These findings show that local microinjection of topiramate into the nucleus accumbens is effective in preventing opioid deprivation symptoms without significant effect on locomotor activity

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Final remedy of the excitation in the analysis of open planar circuits

The Spectral Domain Method (SDM) is widely applied to analyse planar microwave circuits, but open planar circuit analysis with SDM requires an efficient excitation modeling technique. Recent excitation modeling technique is very efficient but needs an improvement at low frequencies. This paper introduces an interpolation technique to improve the deficiency of the recent excitation modelling at low frequencies

Computationally efficient solution for multilayer microwave circuits

The Spectral Domain Method (SDM) is widely applied to analyse two layer planar microwave circuits. Adaptation of this technique to multilayer structures requires an efficient derivation of the Green’s function. This paper provides an iterative derivation for computer design tool programmers

A new route to fast accurate design tool for open planar circuit analysis

Spectral Domain Method (SDM) is one of the best known techniques for developing full-wave design tool at the operating frequency of interest. However full-wave analysis requires more computer power and takes time to yield results. The aim of this paper is to enhance SDM to make it as fast as the simpler methods. The SDM analysis requires the definition of the unknown current distribution on the metallisation of the circuit. The minimisation of the number of basis functions required is crucial to the efficiency of the technique, therefore, sub-gridding, the inclusion of a priori knowledge of current distribution by using precalculated current basis functions and re-mapping of precalculated basis function are employed in the present implementation

Fast rigorous impedance matrix calculations in SDM for analysis of open planar structures

Spectral Domain Method (SDM) has been chosen to develop a technique which is accurate, yet retains the interactive design tool capabilities of a simpler method. In this paper several enhancements will be presented to speed up impedance matrix calculation which must be repeated at each spot frequency in SDM. In addition, an adaptive truncation which limits the numerical integration over an infinite surface to the finite computer resources will be introduced. The location vector calculation will also be presented in this contribution to reduce the number of impedance matrix elements to be calculated. Moreover a technique which cannot completely be classified one way or other will be introduced. This enhancement reduces the number of impedance matrix elements in one dimension and hence speeds up overall numerical integration