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The formation mechanisms of the mega-dunes and lakes in the hinterland of Badain Jaran Desert, China, is the focus of extensive academic research in the field of geoscience, and an often debated topic is whether atmospheric precipitation on the mega-dune can infiltrate to recharge groundwater. In the present study, the probability distribution functions and the return period analysis of extreme daily precipitation based on long-term precipitation records for the southern margin of Badain Jaran Desert and 2-year observation of hinterland precipitation were used to classify precipitation in the desert region. The data of automatic weather station and eddy covariance system in the desert hinterland were used to analyze evaporation on the mega-dune surface after various rain events. The results showed that the rain events in the desert could be divided into three categories. The first is conventional precipitation (CP), which is below 5 mm, accounting for roughly 90 % of all rain events in the desert. The second and third categories are ordinary annual maximum (OAM) and extreme precipitation (EP), in which precipitation is roughly 20 mm and more than 40 mm, respectively. The atmospheric precipitation of CP and OAM evaporated from the mega-dune surface in 1-3 days and 3-4 weeks, respectively. Following an EP event, the mega-dune evaporation was negatively influenced by the upper dry sand layer, and a lengthy period was required for its complete removal. The accumulative evaporation and accumulative precipitation of all three types of rain events indicated that local atmospheric precipitation had no significant contribution to recharging the groundwater system in the hinterland of Badain Jaran Desert. This research will benefit comprehensive elucidation of the formation mechanism of lakes in the hinterland of Badain Jaran Desert. [ABSTRACT FROM AUTHOR]

The effect of density of hydrogen-bonding donor (HBD) on the formation of layer-by-layer assemblies of poly(4-vinylpyridine) and poly(4-vinylphenol) was investigated. For this purpose, a series of ethyl-substituted poly(4-vinylphenol) (EsPVPhf) with variable ethyl substitute percentage was synthesized by grafting the phenol moiety along the poly(4-vinylphenol) backbone with 1-bromoethane. UV-vis spectroscopy revealed a uniform deposition process of the hydrogen-bonded multilayer consisting of poly(4-vinylpyridine) (PVPy) and EsPVPhf with variable density of HBD. Notably, it was found that increasing the HBD density of EsPVPhf resulted in a marked decrease of both amount of polymers adsorbed and film thickness, which should be related to the EsPVPhf conformation change from coiled state to extended conformation in ethanol solution. Compared with the effect of charge density in polyelectrolyte multilayer, however, there does not exist a critical density of HBD in our case of hydrogen-bonded multilayer assembly. In addition, surface structures of PVPy/EsPVPhf multilayer films also can be tailored controllably by adjusting HBD density of EsPVPhf. As a result, a new method for tuning the structure of hydrogen-bonding-directed multilayer films was developed. [ABSTRACT FROM AUTHOR]

Focuses on the cardiac protective role of novel erythrocyte-derived depressing factor (EDDF) in spontaneous hypertensive rats (SHR), calcium overload (CaO) rats, and Wistar rats. Evaluation of the EDDF mechanism; Measurement of mean artery pressure (MAP), heart rate (HR) and LVdp/dtmax; Use of inorganic phosphate assay to determine the effect of EDDF on the Ca2+-ATPase activity in myocardial sarcoplasmic reticulum (SR) of CaO rats; Use of 45Ca2+ radioactive isotope measurement to determine calcium transport in myocytes; Use of the Western blot method to determine the phosphorylation levels of extracellular signal-regulated protein kinases (ERK1/2) in myocardial tissue of SHR and CaO rats; Observation of the unltrastructures of cardiac muscle cells with the transmission electron microscope; Indication that EDDF can significantly lower MAP, HR and LVdp/dtmax in a dose dependent manner; Effect on the ultrastructural lesion of cardiac muscle cells; Finding that uptake and release rate from myocardial SR and CaO rats significantly decreased compared to the control.

The Donggutuo site, situated in the east margin of Nihewan basin, is one of the most important Paleolithic sites in China, characterized by the longest excavation seasons and the most abundant cultural remains recovered in the region. Based on well-constructed sporopollen, sediment grain size analysis, magnetic susceptibility, and iron oxide analysis of the 2000-2001 excavated section, four stages of environmental change in the Nihewan Beds are identified by the authors. The results indicate four major stages of environment and climate change from 1) warm and humid forest grass to 2) temperate and humid forest grass to 3) temperate and dry forest grass to 4) warm and humid forest, which is suitable for hominid occupation. The changes correspond to the stages of lake transgression and regression. The environment after the lake died out away has been cold and dry boschveld. The hominid activities at the site took place in the Early Pleistocene (1.10 Ma), which corresponds to the early three environmental stages. Therefore, it can be inferred that the early hominids adapted to the relatively low lake level episodes through activities involving sporadic stone tool making, procuring of raw materials for tools, concentrating stone artifacts, and hunting and butchering. In conclusion, the results will be of great significance to research regarding the relationship between hominid occupation and environmental changes as well as the adaptive behaviors of early humans at the Donggutuo site. [ABSTRACT FROM AUTHOR]

Evaluates the protective role of a human erythrocyte-derived depressing factor (EDDF) on blood vessels. Examination of the effect of EDDF on vascular function and ultrastructure using isolated vascular ring perfusion microscopy; Contractile response of calcium-overload rats to phenylephrine; Ability of EDDF to protect blood vessels against injury by influencing calcium transport.