Thickness Optimization of Thin-Film Tandem Organic Solar Cell.

The polymer solar cells also known as organic solar cells (OSCs) have drawn attention due to their cynosure in industrial manufacturing because of their promising properties such as low weight, highly flexible, and low-cost production. However, low η restricts the utilization of OSCs for potential applications such as low-cost energy harvesting devices. In this paper, OSCs structure based on a triple-junction tandem scheme is reported with three different absorber materials to enhance the absorption of photons which in turn improves the η, as well as its correlating performance parameters. The investigated structure gives the higher value of η = 14.33% with Jsc = 16.87 (mA/m2), Voc = 1.0 (V), and FF = 84.97% by utilizing a stack of three different absorber layers with different band energies. The proposed structure was tested under 1.5 (AM) with 1 sun (W/m2). The impact of the top, middle, and bottom subcells' thickness on η was analyzed with a terse to find the optimum thickness for three subcells to extract high η. The optimized structure was then tested with different electrode combinations, and the highest η was recorded with FTO/Ag. Moreover, the effect of upsurge temperature was also demonstrated on the investigated schematic, and it was observed that the upsurge temperature affects the photovoltaic (PV) parameters of the optimized cell and η decreases from 14.33% to 11.40% when the temperature of the device rises from 300 to 400 K.

Pattern of coronary artery disease with no risk factors under age 35 years.

BACKGROUND: Coronary artery disease (CAD) is no more deemed to be an ailment of the 4th or 5th decade; rather an earlier age incidence is not infrequently encountered in our population. However, there are a few data regarding CAD in young adults, and much about its underlying pathology still remains undetermined. The objective of this study was to delineate the coronary arterial disease pattern in adults under the age of 35 years, but having no known coronary risk factors. METHODS: This prospective study was conducted at the Cardiology Departments of all 3 public sector tertiary care hospitals in Peshawar from Jun 2008 to Dec 2009. After having excluded the traditional risk factors for CAD, patients under the age of 35 years with objective evidence of CAD were subjected to percutaneous coronary angiography. RESULTS: Out of a total of 104 patients, 85 (81.73%) patients were men, and 19 (18.27%) were women. The mean age of the whole group was 32.66 +/- 3.237 (22-35) years. Significant CAD (> 50% diameter narrowing of at least one major coronary artery) was found in 87 (83.7%) patients while 17 (16.3%) patients had non-atherosclerotic coronary artery disease, including 12 (11.53%) patients having normal coronary arteries, 1 (1%) patient had anomalous origin of right coronary artery (RCA), 1 (1%) patient had coronary arteritis, 2 (1.92%) patients had coronary artery ectasia, and 1 (1%) patient had a myocardial bridge over left anterior descending artery (LAD). Among the patients with significant CAD, the prevalence rate of one, two and three vessel disease was 54 (51.9%), 22 (21.2%) and 11 (10.6%) respectively. Almost 50% of the lesions occurred in LAD followed by 25% in RCA and 20% in circumflex, while only one patient (1%) had isolated significant CAD of left main coronary artery. Osteal segments were involved in 10%, proximal in 61%, mid in 21% and distal segments in 7% of the lesions. CONCLUSION: In the younger age group, CAD is mostly a disease of men, single vessel CAD predominates with LAD involvement mostly, predominant osteal to proximal segment involvement of vessels, and a much higher incidence of normal coronaries and non-obstructive CAD is met with.

Electrical storms and their prognostic implications.

BACKGROUND: Prevention of sudden cardiac death has always been a challenge for electrophysiologists and to date, automatic implantable cardiovertor defibrillator (AICD) is found to be the only remedy. This device delivers an intracardiac shock whenever it senses a fatal ventricular arrhythmia in order to achieve sinus rhythm. If the delivery of these intracardiac shocks becomes frequent, the situation is declared as an electrical storm. This article deals with the frequency, precipitating factors and prevention of electrical storms. METHODS: One hundred and ten episodes of electrical storms (a total of 668 shocks) were retrospectively analysed in 25 recipients of automatic implantable cardioverter defibrillators. ECG, echocardiography, serum electrolytes, urea and creatinine were done for all the patients, and they were hospitalized for a minimum of 24 hours. RESULTS: During the 3 year study period, all the 25 patients with an implantable cardiovertor defibrillator, on an average, received one shock per two years. However, 12 out of these 25 patients (50%) had more than two shocks within 24 hours. Most of these patients with electrical storms were having active ischemia, electrolytes imbalances or renal failure. CONCLUSION: Electrical storms are common in patients with coronary artery disease with impaired left ventricular functions. Ischemia, electrolytes imbalances and renal failure predispose to the electrical storms. Electrical Storms are predictors of poor prognosis.

Frequency of Brugada-type ECG pattern (Brugada sign) in an apparently healthy young population.

OBJECTIVE: To determine the frequency and demographic features of subjects with Brugada-Type ECG pattern in apparently healthy young population. STUDY DESIGN: Cross sectional descriptive study. METHODS: This study was conducted at School of Nursing Hayatabad Medical Complex, Public Health School, Post Graduate College of Nursing, Qurtaba College, Brain's Post Graduate College and Gandhara Institute of Science and Technology Hayatabad Peshawar from June 2006 to May 2007. A total of one thousand one hundred (1100) subjects, 712 males and 388 females, were included in the study. A prospective analysis of the eleven hundred electrocardiograms (ECG) of healthy young subjects in the above institutions were included in this study. RESULTS: Brugada-Type ECG pattern frequency was 0.8% (nine out of one thousand one hundred healthy subjects). Five cases (0.45%) were observed between 16 to 20 years of age and four cases (0.36%) were observed in 21 years and above. Out of total of nine cases of Brugada-Type ECG pattern (Brugada Sign), seven were males (0.6%) and two were females (0.2%). CONCLUSION: Frequency of Brugada-Type ECG pattern was 0.8% in the apparently healthy young students in Hayatabad Peshawar.