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J H Wen

Publications and source records attributed to J H Wen.

2 recordsLinked to original sources

[Image reconstruction based on tomosynthesis].

As a reconstruction method earlier than CT, tomosynthesis has its characteristic. This paper first analyzes principles of tomosynthesis, through transformation of equation set of tomosynthesis, which describes relation between sectional image and projection image, and we have proved that tomosynthesis is the same as Algebraic Reconstruction Techniques essentially. Reconstruction of tomosynthesis is indeed the reconstruction of Algebraic Reconstruction Techniques which under limited angle. We may regard all directive projection information as constitution of two limited angle projection information. Finally we reconstruct sectional image by using conception of "row" in tomosynthesis. And computer simulation has proved our conclusion to be correct.

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Analysis for 1,3-bis(2-chloroethyl)-1-nitrosourea by chemical ionization mass spectrometry.

We used chemical ionization mass spectrometry to quantify the cancer chemotherapeutic agent 1,3-bis(2-chloroethyl)-1-nitrosourea in biological fluids. A stable isotope-labeled internal standard was added to the fluid being analyzed. Protonated molecular ion intensity ratios were determined by selected ion monitoring of sample extracts inserted directly into the chemical ionization source. Peak ratios were calculated for chlorine isotope ratios in their natural abundance, to verify the integrity of the data acquired, and to compute the drug concentration. The assay was applied to measure the compound in rat blood and plasma and in human plasma, and to monitor in vitro metabolism in rat-liver microsomal preparations. For the analyses we used a quadrupole mass spectrometer interfaced to a commercial computer system. Data-system characteristics are described.

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