Biomedical subjects

Jianping Cheng

Publications and source records attributed to Jianping Cheng.

6 recordsLinked to original sources

PubMed2006

A BPF-type algorithm for CT with a curved PI detector.

Helical cone-beam CT is used widely nowadays because of its rapid scan speed and efficient utilization of x-ray dose. Recently, an exact reconstruction algorithm for helical cone-beam CT was proposed (Zou and Pan 2004a Phys. Med. Biol. 49 941-59). The algorithm is referred to as a backprojection-filtering (BPF) algorithm. This BPF algorithm for a helical cone-beam CT with a flat-panel detector (FPD-HCBCT) requires minimum data within the Tam-Danielsson window and can naturally address the problem of ROI reconstruction from data truncated in both longitudinal and transversal directions. In practical CT systems, detectors are expensive and always take a very important position in the total cost. Hence, we work on an exact reconstruction algorithm for a CT system with a detector of the smallest size, i.e., a curved PI detector fitting the Tam-Danielsson window. The reconstruction algorithm is derived following the framework of the BPF algorithm. Numerical simulations are done to validate our algorithm in this study.

Algorithms↗

PubMed2006

[Effects of different irrigation modes on biological characteristics and water use efficiency of paddy rice].

With hybrid rice cultivar Liangyou Peijiu as test material, this paper studied its biological characteristics and water use efficiency under effects of four irrigation modes. Compared with continuous flooding irrigation, intermittent irrigation increased the leaf area index, photosynthetic rate and water use efficiency, and decreased the leaf transpiration rate. Semi-dry cultivation increased the leaf water use efficiency, while dry cultivation decreased the leaf area index, photosynthetic rate, and water use efficiency, and induced the leaf senescence in later growth period. Under intermittent irrigation, semi-dry cultivation and dry cultivation, the water consumption of paddy rice was 8. 75% , 17. 96% and 29. 69% lower, and its grain yield was 24. 02% higher but 5. 07% and 38. 93% lower than that under continuous flooding irrigation, respectively. The water use efficiency was the highest under intermittent irrigation, relatively high under semi-dry cultivation, but relatively low under continuous flooding irrigation and dry cultivation. Compared with other irrigation modes, intermittent irrigation increased the milled rice rate, head rice rate and grain length, while decreased the chalky rice and chalkiness. With the reduction of water consumption, the amylose content of rice grain decreased, but the gel consistency and protein content increased. Intermittent irrigation could be a favorable irrigation mode for the paddy rice planting in Southern China.

Agriculture↗

PubMed2005

Application of fluorescence-based resistance gene analog analysis for genotyping plant genetic resources.

Conventional approaches for detecting disease resistance gene analogs (RGAs) in plants are based on agarose gels or on polyacrylamide gel electrophoresis (PAGE) in combination with silver staining or radioactive labeling. A modified method for RGA analysis has been developed by using fluorescence-labeled primers for PCR amplifications. The amplified fragments are detected by denaturing PAGE using an automated laser fluorescence DNA sequencer and analyzed by fragment analysis software. This technique is not limited to specific plant species and is suitable for high-throughput genotyping plant genetic resources. We demonstrate here the efficiency of this method for comparison of RGA patterns in diverse plant species and for genotyping of natural populations of the wheat progenitor, Triticum dicoccoides.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2004

Methodology study on evaluation of radon flux from soil in China.

Radon flux rate from soil is one of the most important factors for the evaluation of environmental radon levels. The objective of our study is to make a rough estimation of the nationwide radon flux rate from soil in China. Considering the applicability to the large area and complex distribution of soil types in China, a simple model was established. To test the model, field measurements on radon flux rate totally in 47 points from different areas were carried out from spring to summer in 2003. Laboratory experiments of each soil sample on related soil properties, such as radium contents, water contents, soil dry bulk density and soil texture were performed simultaneously. Approximately 30% of the samples had very consistent calculated values with their measured values, their relative errors were less than 0.25. In spite of the large uncertainties in the model which is influenced by so many factors, the considerable validation of the model can be shown. Based on the discussion of distribution of the errors as well as the reasons causing the errors, a trial modification of the model was made. A modification function looked necessary when soil water content was <10%.

Algorithms↗

PubMed2002

Vector entropy imaging theory with application to computerized tomography.

Medical imaging theory for x-ray CT and PET is based on image reconstruction from projections. In this paper a novel vector entropy imaging theory under the framework of multiple criteria decision making is presented. We also study the most frequently used image reconstruction methods, namely, least square, maximum entropy, and filtered back-projection methods under the framework, of the single performance criterion optimization. Finally, we introduce some of the results obtained by various reconstruction algorithms using computer-generated noisy projection data from the Hoffman phantom and real CT scanner data. Comparison of the reconstructed images indicates that the vector entropy method gives the best in error (difference between the original phantom data and reconstruction), smoothness (suppression of noise), grey value resolution and is free of ghost images.

Algorithms↗

PubMed2002

Combined transcatheter arterial chemoembolization and beta-ultrasound guided portal vein embolization in the treatment of hepatocellular carcinoma.

OBJECTIVE: To study the effect of transcatheter arterial chemoembolization (TACE) combined with beta-ultrasound guided portal vein embolization (PVE) through fine-needle liver puncture for hepatocellular carcinoma. METHODS: 209 patients with primary hepatocellular carcinoma were divided into TACE group (104 patients) and TACE + PVE group (105 patients). RESULTS: The response rates (CR + PR) were 37.5% in TACE group and 57.2% in TACE + PVE group (P < 0.01). Tumor thrombi became lessened or resolved in the portal vein with incidences of 22.2% in TACE group and 68.8% in TACE + PVE group (P < 0.01). The 1-, 2- and 3-year survival rates were 65.1%, 36.3% and 20.5% in TACE group and 95.6%, 59.6% and 39.1% in TACE + PVE group (P < 0.05). CONCLUSION: The effect of TACE combined with PVE is much more effective than TACE alone for hepatocellular carcinoma. Beta-ultrasound guided portal vein embolization through fine-needle liver puncture is effective, easy, safe and should be widely practiced.

Adult↗