Biomedical subjects

Lu Zhang

Publications and source records attributed to Lu Zhang.

95 records · Page 6Linked to original sources

PubMed2002

[Changes of crop yield and soil fertility under long-term application of fertilizer and recycled nutrients in manure on a black soil III. Soil nutrient budget].

The nutrient budget of fertilization models under different treatments was calculated using data from a field experiment over the period of 1985-1999. The results indicated that application of nitrogen fertilizer accelerated a large deficit of soil phosphorus, and the use of nitrogen and phosphorus accelerated the deficit of potassium. The experimental data demonstrated the appearance of a large area of soil deficit of phosphorus from 1970s and of potassium from 1980s in China. Nutrient recycled in farming system improved soil nutrient budget, but could not meet the nutrient requirements from high-yield crops. The use of recycled nutrients with an appropriate use of fertilizers according to the soil fertility could produce higher crop yields, balance soil nutrient budget, and not cause surplus nutrients to emit into environment.

Agriculture↗

PubMed2002

[A long-term field trial on fertilization and on use of recycled nutrients in farming systems IV. Soil fertility changes].

The fertility changes of soil under different fertilization treatments of a twelve years field trial indicated that the application of compost recycled in a farming system with appropriate amount of fertilizer applied to balance the soil nutrient budget, could not only produce higher crop yields and less surplus of nutrients into environment, but also improved soil fertility with significant increase of soil organic carbon and nitrogen in cultivated layer. However, maintaine higher soil available phosphorus, it was not sufficient just to balance the budget of soil phosphorus, and more phosphorus fertilizer application was needed.

Agriculture↗

PubMed2002

[Effect of different fertilization system on soil nutrient budget].

A long-term experiment was carried out on a damp palm soil about ten years under the condition of nutrient recycling and reutilization. The quantity of crop nutrients transferred from the system, and the nutrient budget of N, P and K in soil were studied. The results of a ten-year field experiment indicated that the use of nutrients recycled in the farming systems with appropriate amount of fertilizers applied according to the soil nutrient supplying ability could not only produce high crop yield, but also balance the soil nutrient budget, so that, there were no significant surplus of nutrients (mainly inorganic nitrogen) which might emit or leach out of soil into environment.

Agriculture↗

PubMed2001

A Study of Thin Liquid Films as Related to the Stability of Crude Oil Emulsions.

In this paper, we report the influence of surface-active compounds on the stability of crude oil emulsions using the apparatus designed for bilayer lipid membrane studies. The results obtained show that natural surface-active materials in crude oil, such as petroleum acids and asphaltenes, play a pivotal role. The ionized acids formed by the reaction between the petroleum acids and the alkali can decrease the interfacial tension and accelerate the thinning as well as the breakdown of the thin liquid film. The asphaltenes can adsorb onto the interface and improve the stability of the film. The order of the stability of the films between crude oil and alkaline solutions is found to be as follows: crude oil with asphaltenes removed (ii) <crude oil (i) <crude oil with both asphaltenes and petroleum acids removed (iv) <crude oil with petroleum acids removed (iii). Copyright 2001 Academic Press.

Journal Article↗

PubMedDate not supplied

A protein chip system for parallel analysis of multi-tumor markers and its application in cancer detection.

BACKGROUND: Tumor markers are routinely measured in clinical oncology. However, their value in cancer detection has been controversial largely because no single tumor marker is sensitive and specific enough to meet strict diagnostic criteria. One strategy to overcome the shortcomings of single tumor markers is to measure a combination of tumor markers to increase sensitivity and look for distinct patterns to increase specificity. This study aimed to develop a system for parallel detection of tumor markers as a tool for tumor detection in both cancer patients and asymptomatic populations at high risk. MATERIALS AND METHODS: A protein chip was fabricated with twelve monoclonal antibodies against the following tumor markers respectively: CA125, CA15-3, CA19-9, CA242, CEA, AFP, PSA, free-PSA, HGH, beta-HCG, NSE and ferritin. Tumor markers were captured after the protein chip was incubated with serum samples. A secondary antibody conjugated with HRP was used to detect the captured tumor markers using chemiluminescence technique. Quantification of the tumor markers was obtained after calibration with standard curves. RESULTS: The chip system showed an overall sensitivity of 68.18% after testing 1147 cancer patients, with high sensitivities for liver, pancreas and ovarian tumors and low sensitivities for gastrointestinal tumors, and a specificity of 97.1% after testing 793 healthy individuals. Application of the chip system in physical checkups of 15,867 individuals resulted in 16 cases that were subsequently confirmed as having cancers. Analysis of the detection results with a Support Vector Machine algorithm considerably increased the specificity of the system as reflected in healthy individuals and hepatitis/cirrhosis patients, but only modestly decreased the sensitivity for cancer patients. CONCLUSION: This protein chip system is a potential tool for assisting cancer diagnosis and for screening cancer in high-risk populations.

Antibodies, Monoclonal↗