Water use sources and its influencing factors of Pinus massoniana and Quercus acutissima community in hilly region of Southern China.

The process of plant water use is complex and changeable, which is affected by various factors. Exploring the sources and influencing factors of plant water use can provide reference for clarifying the mechanisms of forest water adaptation under climate change. We chosen the typical forest communities in the hilly region of Sou-thern China, Pinus massoniana and Quercus acutissima mixed forest as the research object. By analyzing water sources of plants in different seasons, the factors affecting the changes of water sources were explored in combination with soil water, precipitation, and plant roots. The results showed that water use characteristics of P. massoniana and Q. acutissima were similar and both mainly utilized 0-40 cm soil water during the dry season, with proportions of 60.0% and 66.6%. During the rainy season, as soil water content of deep layers increased, the main water sources of both gradually shifted towards deep soil. The similarity proportion indices of P. massoniana and Q. acutissima were above 60%, indicating that there was an obvious water competition between them. Root system of Q. acutissima had plasticity in water absorption, and played a dominant role in absorbing shallow water during the dry season. Water was the main driving factor for water source transformation of Q. acutissima and P. massoniana during the rainy season. Compared with P. massoniana, Q. acutissima was more sensitive to the changes of water sources. Under the background of future warming and drying, the competition between the two species for shallow water sources might be intensified. Those two species should be sparsely planted or thinned to optimize forest structure to cope with water stress.

Population Parameters and Feeding Preference of Spodoptera litura (Lepidoptera: Noctuidae) on Different Asparagus officinalis Tissues.

Spodoptera litura is an important pest that seriously affects Asparagus officinalis production. To clarify the population characteristics and feeding preference of S. litura on different asparagus tissues, asparagus stems and leaves were selected as the research objects, related studies were conducted by constructing the life table and the feeding preference experiment. The results showed that S. litura could complete its development and reproduction normally on asparagus stems or leaves. Although the adult longevity and fecundity of S. litura on the two types of tissues were not significantly different, the development duration of larvae and pupae, and total preoviposition period on leaves were significantly longer than those raised on stems. The intrinsic rate of increase and finite rate of increase were 0.186 d-1 and 1.204 d-1 on stems, which were significantly higher than those fed on leaves (0.161 d-1 and 1.175 d-1). The mean generation time on stems (32.88 d) was significantly lower than on leaves (36.88 d). It indicated that stems were more suitable for its population growth. In the feeding preference, the third and fifth instar larvae preferred to feed on leaves, and other instar larvae (except for the sixth instar of 2.5 h) had no significant difference. These results will provide a theoretical reference for further research and forecasting and integrated control.

[The preparation of the polylacticacid nanoparticles of cucurbitacin and their drug loading].

This paper introduced an experimental study of the preparation of polylacticacid (PLA) nanoparticles of cucurbitacin (CuC) using a precipitation method. The residual acetone, ratio of CuC PLA precipitates, and the relationships between the ratios of two precipitates and drug incorporation rates were measured. It appeared that the nanoparticles with 60% of PLA incorporated with 5.5% of CuC were formed when acetone was injected into the aqueous phase. As the acetone gradually evaporated, drug incorporation/encapsulation continued, with most of CuC (about 70%) formed new crystalline cores and suspended in the form of microcrystals in the medium, resulting a suspension containing both nanoparticles and microcrystals. We also concluded that this system may not necessarily be suitable for all lipophilic drugs to be prepared to PLA nanoparticles with good incorporation rate. The drug incorporation depended on the interactions among drug, PLA, and organic solvents, in addition to the solubility of the drug.

[Studies on purification of the extract of fructus Gardeniae for injection by macroreticular resins].

OBJECTIVE: To purify the extract of fructus gardeniae for injection by macroreticular resins in purification process of traditional Chinese medicine (TCM) Injections. METHOD: Using fructus gardeniae as sample, on base of obtaining the extract by employing macroreticular resin, quality evaluation and rationality of purification methods had been studied by the quantitative analysis of active ingredients and the characteristics of micromeritics, safety and stability of the extract. RESULT: The experiment showed the extract of fructus gardeniae for injection had been produced successfully by macroreticular resin. CONCLUSION: Using macroreticular resins is a promising purification way of TCM injections, whereas a more consummate method of quality evaluation must be established to ensure safety, efficiency and stability of the preparation in the process.