Nitric oxide (NO) is an important cellular signaling molecule that modulates various physiological activities. Angiogenesis-promoting activities of NO-donor drugs have been explored in both experimental and clinical studies. In this study, a structurally well characterized and water-soluble neutral {Fe(NO)2}(9) DNIC [(S(CH2)2OH)(S(CH2)2NH3)Fe(NO)2] (DNIC 2) was synthesized to serve as a NO-donor species. The antitumor activity of DNIC 2 was determined by MTT assay, confocal imaging, and Annexin-V/PI staining. The IC50 values of DNIC 2 were 18.8, 42.9, and 38.6 μM for PC-3, SKBR-3, and CRL5866 tumor cells, respectively. Moreover, DNIC 2 promoted apoptotic cell death via activation of apoptosis-associated proteins and inhibition of survival associated proteins. In particular, DNIC 2 treatment suppressed PC-3 tumor growth by 2.34- and 19.3-fold at 7 and 21 days, in comparison with the control group. These results indicate that water-soluble DNIC 2 may serve as a promising drug for cancer therapy.

The metro system is the main mode of transportation in Taipei City. The air quality of metro stations is crucial for passengers. This study investigated particle size distribution and its elemental composition and assessed tunnel washing performance in the Taipei Rapid Transit System (TRTS). A 24-hour particle sampling process was performed in the tunnels, platforms, and entrances and exits to measure particulate matter (PM) 2.5 and PM 10 concentrations in an underground metro station and to analyze PM metal components. PM 10 and PM 2.5 concentrations decreased sequentially from the tunnels to the platforms and then to the entrances and exits to ambient environment in the metro station. The main metal components of suspended particulates in the TRTS mainly included iron, barium, copper, manganese, magnesium, aluminum, chromium, zinc, nickel, and lead. The total PM 10 and PM 2.5 metal proportions were 33.9%-24.7% and 32.9%-22.8%, respectively. Furthermore, the effectiveness of tunnel washing in reducing the PM concentration was investigated. Monitoring results showed an increase in PM 10 and PM 2.5 concentrations after tunnel washing on the first day. The PM concentration started to decrease from the second day. Furthermore, 3.5 months after tunnel washing, the PM 10 concentration decreased by 45.9%, and 2 months after tunnel washing, the PM 2.5 concentration decreased by 71.3%. The mechanism of the continuous reduction in the PM 10 concentration after cleaning is probably related to the porous material of tunnel walls, which may provide a deposition sink for aerosol particles, as well as the filter effect of the air conditioning system. This is the first study to use full-section tunnel washing to reduce PM exposure at mass rapid transit (MRT) stations. Although full-section tunnel washing reduced the PM concentration in the metro station, accessorial technology, such as the air conditioning system or platform design, may help in reducing the exposure of MRT passengers.

No abstract