Optimization of Shielding Effectiveness of Coaxial Double Braided Screens in Contact

In this paper, the optimization of the shielding effectiveness of double braided coaxial screens in contact is obtained using semi-empirical single braid optimization formulas. Also the effect of the mutual inductance term between the double braided screens in contact is investigated. A sample optimization has been obtained practically, on one of the standard double braided RF coaxial cable namely, RG-142

A new fire-resistant thin pyramidal absorber based straw and gypsum powder for cost-effective EMC test chambers

In this study, low-cost, easy-fabrication, hollow, and thin pyramidal absorbers based on straw and gypsum powder (SGP-PA) are designed and fabricated for EMC test chambers and measured at 8–12 GHz. The novelty of this paper is the use of straw and gypsum powder materials naturally found in the environment together with carbon fiber (CF) which is preferred as a conductive additive material due to its various properties such as high conductivity, non-pollution in the fabrication process, binding ability thanks to its fibrous structure, and being usable in composite materials by means of its mechanical properties. Consequently, the effects of parameters such as CF ratio, thickness, base layer, and height of SGP-PA on absorptivity level are investigated with simulation/measurement results in order to shed light on absorber designers by obtaining optimum absorption. According to the results, different comments are made for each parameter by obtaining reflectivity values ranging between −21 dB and −50 dB

Isolated coronary artery bypass surgery in patients with mild to moderate ischemic mitral regurgitation: Early results

The optimal management of moderate ischemic mitral regurgitation (MR) remains controversial. Some surgeons advocate coronary artery bypass alone, while others suggest concomitant mitral valve annuloplasty. We aimed to evaluate the early results of isolated coronary artery bypass operation on the cases with mild-to-moderate ischemic MR. Between May 2010 and May 2011, 59 patients (64% male, mean age: 50.5 years) with a preoperative diagnosis of mild-to-moderate ischemic MR underwent a coronary bypass operation. Patients evaluated with preoperative and postoperative (in twelve-month period with an average of five months) transthoracic echocardiogram (TTE). Postoperative mortality was not observed in study group. The preoperative functional capacity of the patients as well as the variables of mild MR and moderate MR showed a statistically significant difference in a positive way when compared with the postoperative functional capacity and MR variables. Postoperative TTE evaluation revealed that only 2 cases have severe MR (3,4%) also 62,7 % of patients have mild and 33.9% of patients have moderate MR. While there was a significant difference in a positive way between the preoperative and postoperative period in terms of left atrial diameter, no significant difference was found for the variables of ejection fraction and pulmonary artery pressure. Among the patients whom undergoing coronary bypass surgery, if there is mild or moderate MR revealed with the TTE prior to the operation, performing only coronary bypass operation will be adequate, and our early results in this matter are satisfactory. But, if severe MR revealed with TTE, performance of mitral valve repair or replacement should be evaluated additional to coronary bypass operation. [Med-Science 2018; 7(1.000): 114-117

Spontaneous Rupture of the Ascending Thoracic Aorta in Young Man

Spontaneous rupture of the aorta without previous history of trauma, hypertension or apparent aortic pathology is rare. Delayed or nonoperative repair of this condition is usually lethal. We report spontaneous rupture of the ascending thoracic aorta in young man. A 20-year-old male who had complained of sudden onset of severe chest pain and dispnea was admitted to our hospital. Initially, acute type A closing aortic dissection was suspected but computed tomography (CT) showed no intimal flap, false lumen or aortic aneurysm. [Med-Science 2015; 4(1.000): 1809-17

A Tie-Over Dressing Using a Silicone Tube to Graft Deep Wounds

Background The most common cause of skin graft failure is the collection of blood or serous fluid underneath the graft. In our study, we describe the use of silicone tube for tie-over dressing to secure the skin graft margins with the aim of decreasing loss of the skin graft, particularly in grafting of deep wounds. Methods Between March 2008 and July 2011, we used this technique in 17 patients with skin defects with depths ranging from 3.5 to 8 mm (mean, 5.5 mm). First, the skin graft was sutured with 3/0 silk suture material from its corners. Then, a silicone round drain tube was sutured with 3/0 absorbable polyglactin 910 over the margins of the graft. Finally, long silk threads were tied over the bolus dressing, and the tie-over dressing was completed in the usual fashion. Results The mean follow-up was 7 months (range, 2-10 months) in the outpatient clinic. Graft loss on the graft margins due to hematoma or seroma was not developed. The results of adhesion between the graft and wound bed peripherally was excellent. Conclusions In our study, we suggest that use of a silicone tube for additional pressure on the edges of skin grafts in case of reconstruction of deep skin defects

Successful Mitral Valve Replacement in Patient with Severe Hemolytic Anemia due to Tight Mitral Stenosis

A 43 year-old woman complained of palpitation and shortness of breath admitted to our hospital. Transthoracic echocardiography revealed severe mitral stenosis and moderate mitral regurgitation. In routine blood tests hemoglobin and lactate dehydrogenase levels were 7.6 g/dL, 520 IU/L respectively. Coombs test was negative. After studying the other intrinsic or extrinsic causes of hemolytic anemia patients anemia was diagnosed as intravascular hemolytic anemia due to tight mitral stenosis. Therefore, mitral valve replacement planned and performed. Hemolysis was resolved after the mitral valve replacement. In conclusion, we report a case of hemolyt ic anemia due to mitral stenosis resolved by mechanical mitral valve replacement. [Med-Science 2016; 5(2.000): 738-41

Effects of rivaroxaban on myocardial ischemia-reperfusion injury in rats

Myocardial infarction and further ischemia-reperfusion injury is a life-threatening conditions in humans. In this study, the effects of rivaroxaban, an anticoagulant agent, were aimed to be studied in a myocardial ischemia-reperfusion (I/R) injury model in rats. Male Wistar-albino rats were allocated into three groups; Rivaroxaban (n=15), control (n=15) and sham (n=10). Myocardial ischemia (30 minutes) and then reperfusion (120 minutes) were surgically performed in the rivaroxaban given (3mg/kg/day by gavage for 10 days before surgical procedures) and the control groups. Electrocardiography changes, blood pressure and heart rate were recorded before ischemia, and during the periods of ischemia and the reperfusion. Hemodynamic and blood parameters were recorded. Necrotic tissue in the myocardium was determined by the triphenyl tetrazolium chloride dye method. The extent of myocardial necrosis and risk area was calculated using a computer-assisted image program. In the rivaroxaban administered group, the size of necrotic area in the myocardium decreased significantly, however, mean heart rate and mean arterial blood pressure did not change. K+ and CK levels in serum, which are indicative of tissue necrosis, were significantly lower in the rivaroxaban group compared to the control group (p [Med-Science 2022; 11(4.000): 1456-60