The impact of the COVID-19 pandemic and behavioral restrictions on electricity consumption and the daily demand curve in Turkey.

The rapid spread of COVID-19 has severely impacted many sectors, including the electricity sector. The reliability of the electricity sector is critical to the economy, health, and welfare of society; therefore, supply and demand need to be balanced in real-time, and the impact of unexpected factors should be analyzed. During the pandemic, behavioral restrictions such as lockdowns, closure of factories, schools, and shopping malls, and changing habits, such as shifted work and leisure hours at home, significantly affected the demand structure. In this research, the restrictions and their corresponding timing are classified and mapped with the Turkish electricity demand data to analyze the estimated impact of the restrictions on total demand and daily demand profile. A modulated Fourier Series Expansion evaluates deviations from normal conditions in the aggregate demand and the daily consumption profile. The aggregate demand shows a significant decrease in the early phase of the pandemic, during the period March-June 2020. The shape of the daily demand curve is analyzed to estimate how much demand shifted from daytime to night-time. A population-based restriction index is proposed to analyze the relationship between the strength and coverage of the restrictions and the total demand. The persistency of the changes in the daily demand curve in the post-contingency period is analyzed. These findings imply that new scheduling approaches for daily and weekly loads are required to avoid supply-demand mismatches in the future. The long-term policy implications for the energy transition and lessons learned from the COVID-19 pandemic experience are also presented.

The comparison of traditional and modified harvesting techniques of left internal mammary artery regarding endothelin-1/2/3 expression and free flow capacity.

AIM: We have conducted this study to seek and observe visual clues through immunohistochemical staining for differences in Et-1/2/3 expression and the free-flow capacity measuring the blood flow through grafts, in the left internal mammary artery grafts prepared either with clipped or nonclipped techniques. METHODS: A total of 40 consecutive patients with a diagnosis of coronary artery disease who would benefit from elective coronary artery bypass graft surgery were randomised into two groups consisting 20 patients each. Left internal mammary artery was harvested by a traditional clipped (control group) and a modified nonclipped (study group) technique in each of the groups. All harvested arterial segments were evaluated for luminal endothelial integrity through hematoxylin&eosin and immunohistochemical staining. RESULTS: The free-flow capacity of left internal mammary artery grafts were significantly higher in nonclipped arteries when compared with that of clipped ones (P=0.001). The arterial lumen of the nonclipped segments were visibly more dilated than the clipped ones. Nonclipped segments presented a lighter immunostaining for Et-1/2/3 when compared with the clipped ones (P<0.001). CONCLUSION: We believe that lesser endothelial damage caused by the lower intraluminal pressure in modifiedly harvested left internal mammary artery segments has positive implications on intraoperative and postoperative cardiac events related to graft vasospasm, especially related with endothelins. We recommend modified left internal mammary artery harvesting in patients going under coronary artery bypass graft operation.

N-acetyl cysteine promotes angiogenesis and clearance of free oxygen radicals, thus improving wound healing in an alloxan-induced diabetic mouse model of incisional wound.

BACKGROUND: This study investigated whether N-acetyl cysteine induces any favourable effects on cutaneous incisional wound healing in diabetic and nondiabetic mice. The wounds were assessed using detection of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) expression, and wound-breaking strength (WBS) measurements. METHODS: In total, 48 BALB/c mice were used. These were divided into four groups, each consisting of 12 mice. Incisional wounds were made on the back of each mouse. Two of the groups consisted of healthy animals and the other two groups consisted of mice with alloxan-induced diabetes. One group of healthy mice and one group of diabetic mice received intraperitoneal N-acetyl cysteine (NAC) 150 mg/kg for 5 consecutive days, while the other two groups were untreated. On the fifth day all animals were killed, and the WBS, oxidative stress parameters, histopathological and immunohisotchemical results were assessed. RESULTS: Both diabetic and nondiabetic mice receiving NAC had lower levels of oxidative stress markers and higher WBS measurements than untreated counterparts. CONCLUSIONS: A mouse model of incisional wound treated with NAC resulted in lower levels of tissue oxidative stress, higher levels of tissue glutathione, and downregulation of iNOS expression coupled with upregulation of VEGF expression, producing an overall favourable clinical outcome of higher WBS and a shorter wound-healing period both in diabetic and nondiabetic mice. Both antioxidant and anti-inflammatory properties of NAC may be involved in this improved healing process for incisional wounds.

Use of warm priming solution in open heart surgery: its effects on hemodynamics and acute inflammation.

Cardiac surgery causes an acute inflammatory response and organ damage. In this study, for the first time in the literature, we compared the effects of priming solutions at 20 degrees C and 36 degrees C on acute inflammatory markers and hemodynamic parameters. Forty patients were recruited and randomized into two groups, each consisting of 20 participants who underwent elective coronary artery bypass grafting operation. Groups were primed with the same solution at different temperatures. Hemodynamic parameters were recorded. Blood samples were drawn pre-operatively and at the 15(th) and 60(th) minutes of aortic cross-clamping and the 24(th) hour following surgery. Serum pre-albumin, alpha-1 antitrypsin, and tumor necrosis factor-alpha levels were determined. The groups were compared statistically. Both of the groups were comparable for mean aortic cross-clamping time and mean time for cardiopulmonary bypass. Mean blood pressure value was significantly lower and the mean amount of ephedrine hydrochloride used was significantly higher in the cold priming group. Spontaneous beating of the heart after removal of aortic cross-clamp significantly was more frequent in the warm priming group. A significant rise was observed in systemic inflammatory markers in the cold priming group. In our study, the lesser amount of ephedrine hydrochloride used and the higher frequency of spontaneous beating of the heart in the warm priming group may be considered as improvements in hemodynamic status. Use of warm priming solution also induced a significant improvement in the acute inflammatory markers. We recommend the use of warm priming solution in open heart surgery.

Effect of low dose electrocautery usage during radial artery harvesting on the neurological outcome of the forearm: a neuroelectrophysiological study.

BACKGROUND: The present study aimed to investigate whether electrocautery caused any thermal injury to the forearm nerves or not. METHODS: We compared the neurological outcome of two different radial artery harvesting techniques through neuroelectrophysiological studies. Preoperative values and postoperative conduction changes after one month were compared in two groups of patients. Each of the groups consisted of 20 patients. Radial arteries were harvested using scissors in Group 1 and with a low dose diathermy technique in Group 2. RESULTS: The mean amplitude of sensory action potentials of radial nerves was significantly reduced postoperatively at the end of the first month in both groups (P = 0.01, P = 0.001). But there were no significant differences between groups with respect to the sensory action potentials of ulnar and median nerves postoperatively. There were no significant differences between groups with respect to radial, ulnar and median nerve motor conduction recordings. CONCLUSION: Low dose electrocautery does not cause excessive nerve injury compared with the scissors technique in radial artery harvesting. Electrocautery may be used safely for RA harvesting in the forearm.

The use of the retinal nerve fiber layer thickness measurement in determining the effects of cardiopulmonary bypass procedures on the optic nerve.

BACKGROUND: Our aim was to determine the effects of cardiopulmonary bypass procedures on the optic nerve by retinal nerve fiber layer thickness measurements. METHODS: Retinal nerve fiber layer thickness was measured using the GDx Nerve Fiber Analyser, 1 day before the surgery and on postoperative days 1, 5 and 30 in 20 patients undergoing coronary artery bypass grafting surgery. RESULTS: Postoperative mean values for retinal nerve fiber layer thickness, except symmetry on the first day and except symmetry and superior nasal ratio on the fifth day, were statsitically decreased. Only the value for the inferior ratio was significantly lower at the end of the first month. CONCLUSIONS: Cardiopulmonary bypass procedures cause a temporary decrease in retinal nerve fiber layer thickness.