[Establishment of New Zealand rabbit models of aplastic anemia].

Objective: To screen for the optimal dose of benzene and cyclophosphamide using an orthogonal design for establishment of New Zealand rabbit models of aplastic anemia.

Methods: Following an orthogonal experimental design, the effects of 3 levels of 4 factors, namely the dose of benzene (A), the dose of cyclophosphamide (B), the number of benzene injections (C), and the number of cyclophosphamide injections (D) were tested in the establishment of New Zealand rabbit models of aplastic anemia using a L (3) orthogonal table, and the optimal protocol for the model establishment was selected from the 9 experimental groups. Each rabbit received subcutaneous injection of benzene on the back every other day, followed by daily cyclophosphamide injection via the ear vein for prescribed times.

[Pollution Characteristics Analysis in Shallow Groundwater of Typical Farmland Area, Southern China].

To analyze the characteristics of shallow groundwater pollution in farmland ecosystem in south China and geochemical behavior of major pollutants in the environment, taking the typical farmland in Taihu River Basin as the object, combined with conventional analysis method of the water quality, fluorescence spectrum technology and multivariate statistical analysis method, the characteristics of the water chemistry in shadow groundwater and the distribution of the dissolved organic matter and the heavy metals were studied. The reasons for all the phenomena were researched as well. The result showed that, water body in the study area showed the reducing atmosphere, the main chemical types of shallow groundwater were HCO-Ca·Na, and compared to the contents of NH-N and NH-N, the concentration of NH-N was higher.

[Determination of Bi in Soils and Sediments by Atomic Fluorescence Spectrometry].

A method for determination of the contents of Bi in soils and sediments by atomic fluorescence spectrophotometry (AFS) was established by using aqua regia as the dissolved medium. In this paper, the instrument parameters, load flow and reducing agent concentration were optimized. Compared with microwave digestion and electric heating plate digestion, water bath digestion demonstrated the better digestion efficiency and was most commonly used.

Determination of Beryllium in Soil and Sediment by Graphite Furnace Atomic Absorption with a Microwave-Acid Digestion Method.

A method for determination of beryllium in soils and sediments by microwave-acid digestion/graphite furnace atomic absorption (GFAA) is described. In this paper, the working conditions of the instrument are optimized, the drawing of calibration curve is expounded, the pretreatment process of soil and sediments (including microwave heating process and the selection of digestion system) is discussed, and the interference of coexisting elements is examined. The sample was pretreated by microwave digestion parameters using HNO₃/ HCl/HF mixed acid system.

Permissible value for vanadium in allitic udic ferrisols based on physiological responses of green Chinese cabbage and soil microbes.

Greenhouse experiments were conducted to study the permissible value of vanadium (V) based on the growth and physiological responses of green Chinese cabbage (Brassica chinensis L.), and effects of V on microbial biomass carbon (MBC) and enzyme activities in allitic udic ferrisols were also studied. The results showed that biomass of cabbage grown on soil treated with 133 mg V kg(-1) significantly decreased by 25.