31 research outputs found
The effects of particle-induced oxidative damage from exposure to airborne fine particulate matter components in the vicinity of landfill sites on Hong Kong
The physical, chemical and bioreactivity characteristics of fine particulate matter (PM2.5) collected near (<1 km) two landfill sites and downwind urban sites were investigated. The PM2.5 concentrations were significantly higher in winter than summer. Diurnal variations of PM2.5 were recorded at both landfill sites. Soot aggregate particles were identified near the landfill sites, which indicated that combustion pollution due to landfill activities was a significant source. High correlation coefficients (r) implied several inorganic elements and water-soluble inorganic ions (vanadium (V), copper (Cu), chloride (Cl−), nitrate (NO3−), sodium (Na) and potassium (K)) were positively associated with wind flow from the landfill sites. Nevertheless, no significant correlations were also identified between these components against DNA damage. Significant associations were observed between DNA damage and some heavy metals such as cadmium (Cd) and lead (Pb), and total Polycyclic Aromatic Hydrocarbons (PAHs) during the summer. The insignificant associations of DNA damage under increased wind frequency from landfills suggested that the PM2.5 loading from sources such as regional sources was possibly an important contributing factor for DNA damage. This outcome warrants the further development of effective and source-specific landfill management regulations for particulate matter production control to the city
Comparison of trauma systems in Asian countries: a cross-sectional study.
OBJECTIVE: This study aimed to compare the demographic characteristics and trauma service structures and processes of hospitals in 15 countries across the Asia Pacific, and to provide baseline data for the integrated trauma database: the Pan-Asian Trauma Outcomes Study (PATOS). METHODS: Medical directors and emergency physicians at PATOS-participating hospitals in countries across the Asia Pacific were surveyed through a standardized questionnaire. General information, trauma care system data, and trauma emergency department (ED) outcomes at each hospital were collected by email and analyzed using descriptive statistics. RESULTS: Survey data from 35 hospitals across 15 countries were collected from archived data between June 2014 and July 2015. Designated trauma centers were identified as the highest hospital level for trauma patients in 70% of surveyed countries. Half of the hospitals surveyed had special teams for trauma care, and almost all prepared activation protocol documents for these teams. Most hospitals offered specialized trauma education programs, and 72.7% of hospitals had a hospital-based trauma registry. The total number of trauma patients visiting the ED across 25 of the hospitals was 300,376. The overall survival-to-discharge rate was 97.2%; however, it varied greatly between 85.1% and 99.7%. The difference between survival-to-discharge rates of moderate and severe injury groups was highest in Taiwan (41.8%) and lowest in Thailand (18.6%). CONCLUSION: Trauma care systems and ED outcomes vary widely among surveyed hospitals and countries. This information is useful to build further detailed, systematic platforms for trauma surveillance and evidence-based trauma care policies
Comparison of trauma systems in Asian countries: a cross-sectional study
Objective This study aimed to compare the demographic characteristics and trauma service structures and processes of hospitals in 15 countries across the Asia Pacific, and to provide baseline data for the integrated trauma database: the Pan-Asian Trauma Outcomes Study (PATOS). Methods Medical directors and emergency physicians at PATOS-participating hospitals in countries across the Asia Pacific were surveyed through a standardized questionnaire. General information, trauma care system data, and trauma emergency department (ED) outcomes at each hospital were collected by email and analyzed using descriptive statistics. Results Survey data from 35 hospitals across 15 countries were collected from archived data between June 2014 and July 2015. Designated trauma centers were identified as the highest hospital level for trauma patients in 70% of surveyed countries. Half of the hospitals surveyed had special teams for trauma care, and almost all prepared activation protocol documents for these teams. Most hospitals offered specialized trauma education programs, and 72.7% of hospitals had a hospital-based trauma registry. The total number of trauma patients visiting the ED across 25 of the hospitals was 300,376. The overall survival-to-discharge rate was 97.2%; however, it varied greatly between 85.1% and 99.7%. The difference between survival-to-discharge rates of moderate and severe injury groups was highest in Taiwan (41.8%) and lowest in Thailand (18.6%). Conclusion Trauma care systems and ED outcomes vary widely among surveyed hospitals and countries. This information is useful to build further detailed, systematic platforms for trauma surveillance and evidence-based trauma care policies
Accelerated Reduction of Bromate in Frozen Solution
Bromate is a common disinfection byproduct formed during ozonation. Reducing bromate into bromide can remove this toxic pollutant, however, not many studies have been done for its environmental fate. In this work, we demonstrate a new transformation pathway that bromate can be efficiently reduced to bromide in frozen solution in the presence of organic reductants like humic substances (HS). The results showed that bromate in frozen solution could be removed by 30-40% in dark condition and 80-90% in irradiation condition lambda > 300 nm) in 24 h, while around 1% bromate was reduced in aqueous solution. The bromate reduction by HS induced a partial oxidation of HS, which was confirmed by X-ray photoelectron spectroscopic analysis of the HS sample recovered from the frozen solution. Photoluminescence analysis of HS revealed that the fluorescence quenching by bromate was observed only with very high concentration of bromate (0.1-0.2 M) in aqueous solution whereas the quenching effect in frozen solution was seen with much lower bromate concentration (5-100 mu M). The highly enhanced removal of bromate in ice is ascribed to the freeze concentration effect that bromate and HS are concentrated by orders of magnitude to accelerate the bimolecular transformation in the ice grain boundary region. Freezing process in cold environments would provide a unique chemical mechanism for the removal of persistent bromate.112sciescopu
Accelerated Reduction of Bromate in Frozen Solution
Bromate is a common disinfection
byproduct formed during ozonation.
Reducing bromate into bromide can remove this toxic pollutant, however,
not many studies have been done for its environmental fate. In this
work, we demonstrate a new transformation pathway that bromate can
be efficiently reduced to bromide in frozen solution in the presence
of organic reductants like humic substances (HS). The results showed
that bromate in frozen solution could be removed by 30–40%
in dark condition and 80–90% in irradiation condition (λ
> 300 nm) in 24 h, while around 1% bromate was reduced in aqueous
solution. The bromate reduction by HS induced a partial oxidation
of HS, which was confirmed by X-ray photoelectron spectroscopic analysis
of the HS sample recovered from the frozen solution. Photoluminescence
analysis of HS revealed that the fluorescence quenching by bromate
was observed only with very high concentration of bromate (0.1–0.2
M) in aqueous solution whereas the quenching effect in frozen solution
was seen with much lower bromate concentration (5–100 μM).
The highly enhanced removal of bromate in ice is ascribed to the freeze
concentration effect that bromate and HS are concentrated by orders
of magnitude to accelerate the bimolecular transformation in the ice
grain boundary region. Freezing process in cold environments would
provide a unique chemical mechanism for the removal of persistent
bromate
Freezing-Enhanced Dissolution of Iron Oxides: Effects of Inorganic Acid Anions
Dissolution
of iron from mineral dust particles greatly depends
upon the type and amount of copresent inorganic anions. In this study,
we investigated the roles of sulfate, chloride, nitrate, and perchlorate
on the dissolution of maghemite and lepidocrocite in ice under both
dark and UV irradiation and compared the results with those of their
aqueous counterparts. After 96 h of reaction, the total dissolved
iron in ice (pH 3 before freezing) was higher than that in the aqueous
phase (pH 3) by 6–28 times and 10–20 times under dark
and UV irradiation, respectively. Sulfuric acid was the most efficient
in producing labile iron under dark condition, whereas hydrochloric
acid induced the most dissolution of the total and ferrous iron in
the presence of light. This ice-induced dissolution result was also
confirmed with Arizona Test Dust (AZTD). In the freeze–thaw
cycling test, the iron oxide samples containing chloride, nitrate,
or perchlorate showed a similar extent of total dissolved iron after
each cycling while the sulfate-containing sample rapidly lost its
dissolution activity with repeating the cycle. This unique phenomenon
observed in ice might be related to the freeze concentration of protons,
iron oxides, and inorganic anions in the liquid-like ice grain boundary
region. These results suggest that the ice-enhanced dissolution of
iron oxides can be a potential source of bioavailable iron, and the
acid anions critically influence this process
Abiotic Formation of Humic-Like Substances through Freezing-Accelerated Reaction of Phenolic Compounds and Nitrite
A previously unknown abiotic humification pathway which is highly accelerated in frozen solution containing phenolic compounds and nitrite was investigated and proposed. The production of humic-like acids (HLA) and fulvic-like acids (FLA) was observed in the frozen solution (-20 degrees C) whereas it was negligible in aqueous solution (20 degrees C). Inorganic nitrogen was transformed into organic nitrogen during the humification process. Mass spectrometry (MS) and elemental analyses, including pyrolysis-GC/MS and FT-ion cyclotron resonance/MS, showed that humification products (HLA and FLA) have chemical structures and compositions similar to nature humic substances. The enhanced humification reaction could be attributed to the freeze-concentration effect, whereby nitrite ions in the unfrozen grain boundary region are transformed into nitrosonium ions which oxidize phenols to phenolic radicals. Confocal Raman microscopy confirmed that catechol and nitrite ions are preferentially concentrated at the ice grain boundary and electron paramagnetic resonance spectroscopic analysis of catechol/nitrite solution detected the phenolic radicals only in frozen solution, not in aqueous solution. The freezing-induced generation of phenolic radicals should lead to the formation of humic-like substances through polymerization. This study identifies and proposes a new humic formation pathway that might work as a model abiotic "bottom-up" mechanism in frozen environmental conditions
BLI-Based Functional Assay in Phage Display Benefits the Development of a PD-L1-Targeting Therapeutic Antibody
The therapeutic functionality of the antibodies from phage display is verified after an initial screening. Several immunological assays such as ELISA, flow cytometry, the western blot, and surface plasmon resonance (SPR) assay are commonly used; the IgG-format antibody is usually preferred to verify the functionality of antibodies, which need elaborative mammalian expression and purification work. Here, we describe a biolayer interferometry (BLI)-based assay that can evaluate the inhibitory functions of antibodies at an earlier stage of screening. To develop a PD-L1-targeting antibody from phage display, we applied the BLI assay to the initial scFv antibody screening, in addition to common ELISA and fluorescence-activated cell sorting (FACS) assays, which showed high advantages and relevance with the in vitro cell-based PD-1/PD-L1 inhibition assay. The same assays for IgG-format antibodies showed high efficiency of the BLI assay in the functional characterization of antibodies, and one candidate selected from the BLI assay resulted in highly efficacious antitumor activity in an in vivo syngeneic mouse study. The BLI assay was also beneficial when searching for antibodies with diverse epitopes. These results demonstrated that the BLI-based inhibition assay is an excellent technique for high-throughput scFv antibody screening in earlier stages and can make phage-display antibody screening more efficient to develop therapeutic candidates
Novel Antibodies Targeting MUC1-C Showed Anti-Metastasis and Growth-Inhibitory Effects on Human Breast Cancer Cells
Mucin1 (MUC1) is aberrantly glycosylated and overexpressed in various cancers, and it plays a crucial role in cancerogenesis. MUC1 is a type I membranous protein composed of α and β subunits. MUC1-α can be cleaved in cancers, exposing MUC1-β (MUC1-C). MUC1-C is involved with multiple cancer cellular functions, which makes it an attractive target for cancer treatment. However, its multifunctional mechanisms have not been fully elucidated and there has not been a successful therapeutic development against MUC1-C. Through a phage display process, we isolated the specific antibodies for the extracellular domain of MUC1-C. The relevant full IgG antibodies were produced successfully from mammalian cells and validated for their MUC1-C specificities through ELISA, dual FACS analysis, BLI assay, and confocal image analysis. In the comparison with reference antibody, elected antibodies showed characteristic bindings on target antigens. In the functionality assessment of high-ranking antibodies, SKM1-02, -13, and -20 antibodies highly inhibited invasion by triple-negative breast cancer (TNBC) cells and the SKM1-02 showed strong growth inhibition of cancer cells. Our results showed that these MUC1-C specific antibodies will be important tools for the understanding of MUC1 oncogenesis and are also highly effective therapeutic candidates against human breast cancers, especially TNBC cells