Inter-regional multimedia fate analysis of PAHs and potential risk assessment by integrating deep learning and climate change scenarios.

Polycyclic aromatic hydrocarbons (PAHs) are hazardous compounds associated with respiratory disease and lung cancer. Increasing fossil fuel consumption, which causes climate change, has accelerated the emissions of PAHs. However, potential risks by PAHs have not been predicted for Korea, and appropriate PAH regulations under climate change have yet to be developed. This study assesses the potential risks posed by PAHs using climate change scenarios based on deep learning, and a multimedia fugacity model was employed to describe the future fate of PAHs. The multimedia fugacity model describes the dynamics of sixteen PAHs by reflecting inter-regional meteorological transportation. A deep neural network predicts future environmental and economic conditions, and the potential risks posed by PAHs, in the year 2050, using a prediction model and climate change scenarios. The assessment indicates that cancer risks would increase by more than 50%, exceeding the lower risk threshold in the southern and western regions. A mix of strategies for developing PAH regulatory policies highlighted the necessity of increasing PAHs monitoring stations and controlling fossil fuel usage based on the domestic and global conditions under climate change scenarios.

Nipple-areolar complex ischemia and necrosis in nipple-sparing mastectomy.

INTRODUCTION: Nipple-sparing mastectomy (NSM), combined with immediate breast reconstruction, has become the preferred surgical option to achieve better patient satisfaction and aesthetic outcome. However, nipple-areolar complex (NAC) ischemia and necrosis are common complications following nipple-sparing technique. MATERIALS AND METHODS: We performed a retrospective analysis of 220 breasts that underwent NSM and immediate reconstruction from May 2010 to December 2016 at our institute. For accurate evaluation of ischemia rate after nipple-sparing mastectomy, we suggested a nipple-areolar ischemia grading system. We also found association between various factors and complications of nipple-areolar complex through statistical analysis. RESULTS: Among 220 breasts that underwent NSM in 207 patients, ischemia occurred in 141 (64.1%) breasts. However, necrosis required surgical reoperation in only 69 (31.3%) breasts. Patient factor affecting NAC complications was existence of ptosis. Also, surgical techniques for periareolar incision as well as oncologic surgeon's technique impacted NAC necrosis. Reconstruction methods including direct-to-implant, latissimus dorsi island flap with implant, and transverse rectus abdominis free flap showed higher rate of necrosis compared to tissue-expander reconstruction. CONCLUSION: We clarified factors that affect NAC necrosis. Among them, modifiable factors were skin tension and periareolar incision. When periareolar incision is necessary, lower periareolar incision is safer than upper periareolar incision to preserve vascularity of NAC.