Naoki Nishimoto

Discrimination Between Infant and Adult Bloodstains Using Micro-Raman Spectroscopy: A Preliminary Study

In the present study, we used micro‐Raman spectroscopy with high‐resolution analysis to discriminate between bloodstains from infants and bloodstains from adults. Raman peaks were detected at 674, 754, 976, 1002, 1105, 1127, 1176, 1248, 1340, 1368, 1390, 1560, and 1611 cm−1; these peaks were derived from hemoglobin, albumin, and glucose. However, a peak was obtained at 1105 cm−1, which was assigned to histidine; this peak was observed only for bloodstains from adults. Human adult hemoglobin (HbA) is composed of an α2β2 tetramer structure, whereas human fetal hemoglobin (HbF) is composed of an α2γ2. Therefore, the lack of a Raman peak at 1105 cm−1 in bloodstains from infants indicates the possibility of two histidine substitutions (His116Ile and His143Ser) in the γ chain of HbF. This study discriminates between bloodstains from infants and bloodstains from adults using micro‐Raman spectroscopy, with beneficial implications in forensic science.

COMPARISON OF THE IN VITRO CYTOTOXICITIES OF NITROGEN DOPED (p-TYPE) AND n-TYPE ZINC OXIDE NANOPARTICLES

The use of NPs in the health care field is increasing. Before their biological application, investigating the toxicities of both n-type ZnO nanoparticles (NPs) and nitrogen-doped (“p-type”) NPs is important. Using L929 cells, the cell viability, oxidative stress, apoptosis induction, inflammatory responses, and cellular uptake were assayed 24h after the addition of n-type ZnO NPs and nitrogen-doped NPs (which act as p-type) (25μg/mL). The ZnO NPs were fabricated using a gas evaporation method. Increased H2O2 generation and decreased levels of glutathione were more evident in with n-type than in those treated with nitrogen-doped (“p-type”) ZnO NPs. Caspase-3/-7 activity was higher in cells treated with n-type ZnO NPs than in those treated with nitrogen-doped (“p-type”) NPs. Elevated levels of TNF-α and IL-1β were observed in cell culture supernatants: IL-1β levels were higher in n-type ZnO NPs than nitrogen-doped (“p-type”) NPs. The cellular Zn uptake of n-type ZnO NPs was higher than nitrogen-doped (“p-type”) NPs. These findings show that n-type ZnO NPs have higher cytotoxicity than nitrogen-doped (“p-type”) ZnO NPs. This may be due to a reductive effect of n-type ZnO NPs that induces higher free radical production, reactive oxygen species (ROS) generation, and cellular uptake of this type of ZnO NPs.