Factors Affecting the Rate of Breast Cancer; Role of Heavy Metals

Breast cancer is caused by uncontrolled growth of breast cells. It is more common in women as compared tothat in men. The breast cancer may be interlinked with the drinking of alcohol, smoking, sex, hormonal therapy, obesity,family history and age. Various epidemiologic studies suggest the role of metals e.g., nickel (Ni), zinc (Zn), arsenic(As),selenium (Se)and cadmium (Cd)as potential risk factors in breast cancer. Humans are exposed to these metals bymeans of drinking water, food and air. The oxidative theory suspects that the complexes formed from these metals invivo, near the location of DNA, catalyze the redox reactions which results in oxidation of DNA. The metals like arsenic(As), chromium (Cr), aluminum (Al), cadmium (Cd) and chromium (Cr)which exist in trace amount are considered ascarcinogens for organisms by IARC (International Agency for Research on Cancer). The carcinogenicity of these metalsmainly depends upon their chemical structure and oxidation states

Bi and Sn Doping Improved the Structural, Optical and Photovoltaic Properties of MAPbI3-Based Perovskite Solar Cells

One of the most amazing photovoltaic technologies for the future is the organic–inorganic lead halide perovskite solar cell, which exhibits excellent power conversion efficiency (PCE) and can be produced using a straightforward solution technique. Toxic lead in perovskite can be replaced by non-toxic alkaline earth metal cations because they keep the charge balance in the material and some of them match the Goldschmidt rule’s tolerance factor. Therefore, thin films of MAPbI3, 1% Bi and 0%, 0.5%, 1% and 1.5% Sn co-doped MAPbI3 were deposited on FTO-glass substrates by sol-gel spin-coating technique. XRD confirmed the co-doping of Bi–Sn in MAPbI3. The 1% Bi and 1% Sn co-doped film had a large grain size. The optical properties were calculated by UV-Vis spectroscopy. The 1% Bi and 1% Sn co-doped film had small Eg, which make it a good material for perovskite solar cells. These films were made into perovskite solar cells. The pure MAPbI3 film-based solar cell had a current density (Jsc) of 9.71 MA-cm−2, its open-circuit voltage (Voc) was 1.18 V, its fill factor (FF) was 0.609 and its efficiency (η) was 6.98%. All of these parameters were improved by the co-doping of Bi–Sn. The cell made from a co-doped MAPbI3 film with 1% Bi and 1% Sn had a high efficiency (10.03%)