Frequency of depression and anxiety among heart failure patients in a tertiary care hospital of Faisalabad, Pakistan Depression & anxiety among cardiac patients

Heart failure (HF) is a chronic illness with high prevalence and mortality, leading toeconomic burden ofhealth due to prolonged hospital stay and re-admissions. Failure to comprehend the importance of identifying mental illnesses could lead to explanations that why the morbidity and mortality of heart failure patients endure to be very high. Objective: To determine the frequency of anxiety and depression in heart failure patients. Methods: It is a descriptive cross sectional study including 323 CHF patients admitted to the Faisalabad Institute of Cardiology hospital, 250 were males and 73 were females, mean age was 54.1 ± 9.2 years having 70 years as maximum and 25 years as minimum.  Data was collected with the help of HADS questionnaire. Patients were interviewed for assessment of anxiety and depression. Data was analyzed using SPSS version 24. Mean and standard deviation was calculated for quantitative data and for qualitative data frequency and percentageswas calculated. To measure the association of anxiety and depression with age categories and gender, chi square test was used. P values less than and equal to 0.05 were taken as significant. Results: The results showed that 43% subjects had <11 score indicating no anxiety, 57% had >11score indicating anxiety. 45% subjects had<11 score indicating no depression, 55% had >11score indicating depression. Conclusions: The study concluded that frequency of depression and anxiety is high in congestive heart failure patients. Strategies are required to assess and diagnose these mental illnesses to establish early treatment which may foster multidisciplinary health care team approach and interventions that address the psychological burden.

Alkali Metal K, Rb, Cs Doped Methylammonium Lead Iodide Perovskites for Potential Photovoltaic Applications

The hybrid perovskite solar cells have become a key player in third generation photovoltaics since the first solid state perovskite photovoltaic cell was reported in 2012. Over the course of this work, a wide array of subjects has been treated: starting with the synthesis and deposition of different charge transport layers, synt hesis of hybrid perovskite materials, optimization of annealing temperature, stability of the material with the addition of inorganic metal ions, and photovoltaic device fabrications. The key advantages of methylammonium lead iodide (CH3NH3PbI3=MAPbI3; CH3NH3=MA) perovskite is the efficient absorption of light, optimum band gap and long carrier life time. The organic components, i.e. CH3NH3, in MAPbI3 perovskites bring instabilities even at ambient conditions. To address such instabilities, an attempt has been made to replace the organic constituent with inorganic monovalent cations; K+1, Rb+1, and Cs+1 in MAPbI3; (MA)1-xBxPbI3 (B= K, Rb, Cs; x=0-1). The optical, morphological, structural, chemical, optoelectronic and electrical properties of the materials have been explored by employing different characterization techniques. Initially methylammonium lead iodide (MAPbI3) compound grows in a tetragonal crystal structure, which remains intact with lower doping concentrations. However, the crystal structure of the material is found to be transformed from tetragonal at lower doping to double phase i.e., simultaneous existence of tetragonal MAPbI3 and orthorhombic BPbI3 (B=K, Rb, Cs) structure at higher doping concentrations. These structural phase transformations are also visible in electron micrographs of the doped samples. The resistances of the samples were seen to be suppressed in lower doping range, which can be attributed to the more electropositive character of inorganic alkali cations. A prominent blue shift has seen in the steady state photoluminescence and optical absorption spectra with higher alkali cation doping, which corresponds to increase in the energy bandgap and this effect is very small in light doped samples. The x-ray photoemission spectroscopy studies of all the investigated perovskite samples have shown the presence of Pb+2 and I-1 oxidation states. The intercalation of inadvertent carbon and oxygen in perovskite films was also investigated by x-ray photoemission spectroscopy. It is observed that the respective peaks intensities of carbon and oxygen, responsible for methylammonium lead iodide decomposition has decreased with partial doping, which can be attributed to the doping of oxidation stable alkali metal cations (K+1, Rb+1, Cs+1). Following this work, some of the properties of the phase pure organicinorganic MAPbI3 have been studied. The selected devices with pristine as well as doped perovskite i.e., (MA)1-xBxPbI3 (B= K, Rb, Cs) based inverted perovskite photovoltaic cells were fabricated and tested their power conversion efficiencies. Later, the power conversion characteristics of the devices were investigated by developing an electronic circuit allowing versatile power point tracking of solar devices. The device with the best efficiency of 15.37% was attained with 30% Cs doping, having device parameters as; open circuit voltage value of 1.08V, photocurrent density (Jsc) of 19.70mA/cm2, and fill factor of 0.72. In case of potassium (K+) based mixed cation perovskite based devices, efficiency of about 13.32% is obtained with 10% doping. Using this approach, the stability of the materials and performances of perovskite based solar devices have been increased. These studies showed that the organic (MA) and inorganic cations (K, Rb and Cs) can be used in specific ratios by wet chemical synthesis procedure for better stability and efficiency of solar cells. We showed that mixed cations lead to a stable perovskite tetragonal phase in low atomic concentrations with no appreciable variation in energy bandgap of the photo-absorber, allowing the material to intact with the properties of un-doped perovskite with enhanced efficiency and stability.