Cílem této dizertační prace je vylepšit existující detektory objektů pomocí sdílení informace a výpočtů mezi blízkými pozicemi v obraze. Navrhuje dvě metody, které jsou založené na Waldově sekvenčním testu poměrem pravděpodobností a algoritmu WaldBoost. První z nich, Early non-Maxima Suppression , přesunuje rozhodování o potlačení nemaximálních pozic ze závěrečné fáze do fáze vyhodnocování detektoru, čímž zamezuje zbytečným výpočtům detektoru v nemaximálních pozicích. Metoda neighborhood suppression doplňuje existující detektory o schopnost zavrhnout okolní pozice v obraze. Navržené metody je možné aplikovat na širokou škálu detektorů. Vyhodnocení obou metod dokazují jejich výrazně vyšší efektivitu v porovnání s detektory, které vyhodnocují jednotlivé pozice obrazu zvlášť. Dizertace navíc prezentuje výsledky rozsáhlých experimentů, jejichž cílem bylo vyhodnotit vlastnosti běžných obrazových příznaků v několika detekčních úlohách a situacích.

Although there are over 1,600 Engineered Nanomaterials (ENMs)-containing consumer products available, our understanding of ENM safety is still limited. Airborne ENMs can readily enter the human body through inhalation potentially leading to many adverse health effects such as cardiovascular and pulmonary diseases. The conventional in vitro submerged cell culture method was developed decades ago and has been widely used as a fast screening method to elucidate cellular toxicity upon exposure to hazardous materials; however, it has many limitations compared with the in vivo models. Our group has previously utilized and validated an integrated low flow system capable of generating and depositing airborne nanoparticles (NPs) directly onto cells at an air-liquid interface (ALI) condition, and our results confirmed that this exposure system produced reproducible toxicological data for ENMs including gold (Au), 16% silver coated onto silica (16% Ag-SiO2), and copper oxide (CuO). To further improve this ALI method for an even closer representation of the in vivo model, a co-culture model containing three cell lines (A549, THP-1 differentiated macrophages, and EA.hy 926) was established and validated for testing ENMs toxicity. The co-culture model was exposed to 16% Ag-SiO2 and CuO NPs under the same protocol (4 h ALI exposure with a concentration of 3.5 mg/m3) as monoculture (A549 only) for comparison. Toxicity was assessed by measuring cell viability, reactive oxygen species (ROS) production, lactate dehydrogenase (LDH) release, and interleukin (IL) 8 level. Results showed that 16% Ag-SiO2 NPs induced higher ROS generation, and CuO NPs produced a significant level of proinflammatory response compared with monoculture. In addition, the co-culture model exhibited a similar response with the primary human bronchial epithelia cell line (HBEC) in terms of ROS and IL-8 responses after CuO NPs exposure, suggesting a more advanced refinement of the conventional model for in vitro inhalation study.

Metal-based engineered nanomaterials (ENMs) have potential to revolutionize diagnosis, drug delivery and manufactured products, leading to greater human ENM exposure. It is crucial to understand ENM pharmacokinetics and their association with biological barriers such as the blood-brain barrier (BBB). Physicochemical parameters such as size and surface modification of ENMs play an important role in ENM fate, including their brain association. Multifunctional ENMs showed advantages across the highly regulated BBB. There are limited reports on ENM distribution among the blood in the brain vasculature, the BBB, and brain parenchyma. In this study, ceria ENM was used to study the effect of size on its pharmacokinetics. Four sizes of ceria ENMs were studied. Five nm ceria showed a longer half-life in the blood and higher brain association compared with other sizes and 15 and 30 nm ceria had a higher blood cell association than 5 or 55 nm ceria. Because of the long circulation and high brain association of 5 nm ceria compared with other sizes, its distribution between the BBB and brain parenchyma was studied. The in situ brain perfusion technique showed 5 nm ceria (99%) on the luminal surface of the BBB rather than the brain parenchyma. For biomedical applications in the central nervous system (CNS), it is vital to develop stable and biocompatible ENMs and enhance their uptake by taking advantage of their unique properties. Cross-linked nanoassemblies entrapping iron oxide nanoparticles (CNA-IONPs) showed controlled particle size in biological conditions and less toxicity in comparison to Citrate-IONPs. CNA-IONPs considerably enhanced MRI T2 relaxivities and generated heat at mild hyperthermic temperatures (40 ~ 42°C) in the presence of alternating magnetic field (AMF). Numerous researchers showed mild whole body hyperthermia can increase BBB permeability for potential brain therapeutic application. Compared to conventional hyperthermia, AMF-induced hyperthermia increased BBB permeability with a shorter duration of hyperthermia and lower temperature, providing the potential to enhance IONP flux across the BBB with reduced toxicity. Overall, ENMs with optimized physicochemical properties can enhance their flux across the BBB into the brain with desirable pharmacokinetics, which provide great potential for diagnosis and therapy in the CNS.