Xiaofeng Bao

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The real-world fuel efficiency and exhaust emission profiles of CO, HC and NOx for light-duty diesel vehicles were investigated. Using a portable emissions measurement system, 16 diesel taxies were tested on different roads in Macao and the data were normalized with the vehicle specific power bin method. The 11 Toyota Corolla diesel taxies have very good(More)
The nitrone, 5,5-dimethylpyrroline N-oxide (DMPO), is a commonly used spin trap for the detection of superoxide radical anion (O2*-) using electron paramagnetic resonance spectroscopy. This work investigates the reactivity of DMPO to O2*- in mildly acidic pH (5.0-7.0). Mild acidity is characteristic of acidosis and has been observed in hypoxic systems,(More)
Amazon Aurora is a relational database service for OLTP workloads offered as part of Amazon Web Services (AWS). In this paper, we describe the architecture of Aurora and the design considerations leading to that architecture. We believe the central constraint in high throughput data processing has moved from compute and storage to the network. Aurora brings(More)
Dynamic queries facilitate exploration of information through real-time visual display of both query formulation and results. Dynamic query sliders are linked to the main visualization to filter data. A common alternative to dynamic queries is to link several simple visualizations, such as histograms, to the main visualization with a brushing interaction.(More)
A new fluorescent chemosensor based on a Rhodamine B and pyrrole conjugate (RBPY) has been designed and synthesized. UV-vis absorption and fluorescence spectroscopic studies show that RBPY exhibits a high selectivity and sensitivity toward Fe(3+) among many other metal cations in a MeOH/H2O solution (3:2, v/v, pH 7.10, HEPES buffer, 0.1mM) by forming a 1:1(More)
A known chemotype of H(3) receptor ligand was explored for development of a radioligand for imaging brain histamine subtype 3 (H(3)) receptors in vivo with positron emission tomography (PET), namely nonimidazole 2-aminoethylbenzofurans, represented by the compound (R)-(2-(2-(2-methylpyrrolidin-1-yl)ethyl)benzofuran-5-yl)(4-fluorophenyl)methanone (9).(More)
The metabolism of 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine chloride (CTHB), a compound with promising pharmacological effects against arrhythmia, was investigated in rat bile. A metabolite and unchanged CTHB were found in the bile. Characterization and structural elucidation of the metabolite was achieved by LC/MS and LC/NMR. The following metabolic(More)
A facile synthesis for novel loperamide analogs as potential μ opioid receptors is described. The synthetic procedure for compound 5, which contains two 4-phenyl piperidine scaffolds, was optimized, and this compound was synthesized in excellent yield. We also describe a mild and highly efficient protocol for the synthesis of compounds 6 and 7.
INTRODUCTION Rhodamine-123 is a known substrate for the efflux transporter, P-glycoprotein (P-gp). We wished to assess whether rhodamine-123 might serve as a useful substrate for developing probes for imaging efflux transporters in vivo with positron emission tomography (PET). For this purpose, we aimed to label rhodamine-123 with carbon-11 (t(1/2)=20.4min)(More)
China’s fuel quality standards and fuel supply management have long been an impediment to improved air quality by hindering the progress of vehicle emission control. This paper summarizes the status of China’s fuel quality standards, fuel supply and vehicle emission standards focusing on the major problems of fuel quality management. The mechanism that(More)