Certain physical and physiological changes occur in the atmospheric levels where flight and space activities take place. Air pressure decreases with increasing altitude and the partial pressure of O₂ decreases in parallel with the atmospheric pressure drop and creates hypoxia in the flight crew and in the passengers. In case of acute hypobaric hypoxia, blood is redistributed to the brain and the heart, whereas blood supply to internal organs, such as kidney and skin is reduced. Peripheral cyanosis can be observed on the fingertips and the lips during hypoxia-induced blood redistribution. Tachycardia develops, but the stroke volume does not change. The coronary blood flow increases in parallel with the rise of cardiac output; however, the presence of severe hypoxia leads to myocardial depression. Coronary reflex vasoconstriction is followed by cardiac arrest. Another important pathology caused by low pressure is decompression sickness. In this disease, immediate reduction of the environmental pressure leads to the dissolved nitrogen transforms into gas, and nitrogen bubbles form in the tissue and in the blood. These bubbles interfere the perfusion of the blood and cause ischemia. Symptoms and signs of cardiac decompression sicknesses are dyspnea, tachypnea, chest pain, cough, hemoptysis, cyanosis, retrosternal discomfort, and rarely, shock. Air embolism of coronary vessels manifests as rhythm disturbances, myocardial infarction, and circulatory collapse. The physical forces that occur because of aircraft movement and affect both the pilot and the aircraft, are called acceleration (G) forces. The basic physical effect of G forces is weight increments and motion restriction. During high +Gz, blood pressure decreases in the brain and increases in the lower extremities. Blood forced to move into the lower parts of the body and lower extremities. Thus, brain perfusion cannot be achieved, and loss of consciousness occurs at approximately +4 Gz acceleration levels. Earth also applies an acceleration force to the objects on or around the world. Therefore, gravitational force is also applied to orbiting spacecraft by Earth. The centrifugal force and the gravitational force are in an equilibrium, weightlessness is created inside the orbiting spacecraft, and this is called microgravity. Blood redistributed to the neck and head veins, and astronauts feel nasal fullness, and bulging around the eyes during space missions. As the time spent in the space progresses, a 22% decrease in plasma volume is observed in the cardiovascular system within 1 week owing to increased venous return, and this causes a temporary hemoconcentration. After staying one week in space, cardiac output increases by 22% whereas peripheral resistance decreases by 14%. Rhythm disturbances are also seen during activities performed in space is and thought to be caused by electrolyte imbalance or stress. There is an increasing demand for high altitude and space travel nowadays. These trips cause several physical and physiological effects on both passenger and flight crew. Therefore, it is necessary to take precautionary measures to carry out these activities safely.

Background: Diabetes Mellitus (DM) is a metabolic disease with a high morbidity and mortality and increasing in prevalence all over the world. Due to the hypoxic, ischemic, inflammatory, and infective environment in DM, diabetic foot ulcers have been treated with medico-surgical interventions and adjuvant hyperbaric oxygen Therapy (HBOT). The purpose of this study was to evaluate the effects of HBOT on hematological indices and biochemical parameters in patients with diabetic foot. Methods: The study group was formed from the file records of 103 male patients who applied to Yunus Emre State Hospital HBOT Center between September 1, 2016 and December 31, 2020, and were treated HBOT with a multidisciplinary approach. Results: There were negative low correlations between number of HBOT sessions and Mean Corpuscular Hemoglobin (MCH) (P = .037, r = −0.207) and Blood Urea Nitrogen (BUN) (P = .037, r = −0.222). White Blood Cell Count (WBC), Neutrophils (NEU), Monocytes (MON), Platelet Count (PLT), and Plateletcrit (PTC) parameters were found to be decreased, and an increase in lymphocytes (LYM), Eosinophils (EOS), Mean Corpuscular Hemoglobin Concentration (MCHC), and Red Cell Distribution Width (RDW) parameters were detected after the treatments (P < .05). Again, after the treatment, glucose (Glu), C-Reactive Protein (CRP), direct bilirubin, and total protein (TP) levels were decreased, and uric acid (UA) levels increased (P < .05). Conclusion: HBOT improved hematological indices in patients and had a beneficial effect on biochemical parameters, particularly Glu and CRP levels. Adjuvant HBOT alleviates diabetic inflammation and has a beneficial effect on diabetic patient treatment.

Aviation accidents are caused by a chain of errors in many steps. Detection and classification of human factors in accidents are critical for taking effective precautions. This study aims to investigate the factors affecting civil aviation accidents in Turkey and increase aviation safety by raising awareness against the contributing factors in the accidents. Final accident reports of Turkish Civil Aviation Accidents, including fatalities or injuries between 2003 and 2017, were analysed retrospectively using the Human Factors Analysis and Classification System (HFACS). 59 aviation accidents were included in this study. Crew Resource Management (CRM) (41.4%), Loss of Situational Awareness (LSA) (39.0%), and meteorology (29.2%) were found to be the most contributing factors in 41 Plane, Helicopter, Glider (PHG) accidents, while meteorology (77.7%) and CRM (61.1%) were found to be the most contributing factors in 18 Balloon accidents. The rate of HFACS levels in the PHG/Balloon accidents were found to be 90.2%/66.6% in Level-1 (Unsafe Acts), 95.1%/100% in Level-2 (Preconditions for Unsafe Acts), 78.0%/94.4% in Level-3 (Unsafe Supervision), and 58.5/83.3% in Level-4 (Organizational Influences). These findings show that human factors are still major contributing factors in aviation accidents. Academic training like CRM, Aviation Meteorology and LSA should be given more frequently to the aviators to prevent accidents. Including Spatial Disorientation, hypoxia, and night vision practical training into the civilian pilot training and integrating HFACS into the "Aviation Safety Management System" might help to reduce aviation accident rates.