[Effects of Fulvic Acid on Absorption and Form Distribution of Heavy Metals on Sediments].

Based on the extracted fulvic acid (FA) from Lake Wuliangsuhai sediments by sequential alkali extraction, this work studied the effects of FA on the adsorption and fraction distribution of heavy metals (HM) on sediments using original sediments and sediments treated with 30% H2O2 as adsorbents. The results showed both organic matter and FA had effects on the HM adsorption onto sediments; The treatments of FA-free conditions and the sediments treated by H2O2 showed relatively strong influence on Cu²âº adsorption, which decreased the Cu²âº adsorption by 17.85%. With the increasing FA addition, the adsorption percentage of HM on both types of sediments showed gradually decreasing trends, with the order of Cu²âº >> Cd²âº > Zn²âº > Pb²âº; when the FA content was more than 5% , FA became the governing factor on the decreasing adsorption percentage of HM. With increasing FA addition, forms distribution of HM showed significant changes in both types of sediments; i. e. FA additions showed significant negative and positive correlations with percentages of metals bound to carbonates and organic matter, respectively, since the FA addition increased the H⁺ concentration of the system, in which H⁺ could activate the metals bound to carbonate from the sediments. As an organophilic weak element, the fraction percentage of Cd bound to organic matter was the lowest with the minimal changes.

[Impacts of Microorganisms on Degradation and Release Characteristics of Organic Phosphorus in Lake Sediments During Freezing Season].

Organic phosphorus (OP) has been considered as an important pool for bioavailable phosphorus. In this work, impacts of microorganisms on the degradation and release of OP in sediments from Lake Wuliangsuhai during freezing season were investigated using chemical sequential extraction methods. The results showed that the concentrations of dissolved total phosphorus (DTP) dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) in overlying water of the sterilization (T(N)) treatments were higher than those of the substrate addition (T(M)) treatments, indicating that the assimilation of anaerobic microorganisms and the disassimilation reduction of iron driven by microorganisms were the main mechanisms govening OP behavior and process across the water-sediments interface. The concentrations of labile OP (LOP) and total labile phosphorus (TLP) decreased during the releasing period. During the first 60 days, the concentrations of moderately labile OP (MLOP) of T(M) treatments decreased, while those of the nonlabile OP (NLOP) increased. During 60-180 days, the MLOP concentrations of T(M) treatments were found increasing, while those of NLOP decreased. During the beginning period (0-60 d), the concentrations of MLOP of T(M) treatments were higher than those of T(N) treatments, while the NLOP concentrations were lower than those of T(N) treatments; and these trends were reversed during 60-180 days. These trends revealed the possibility of transformation between MLOP and NLOP during the releasing process. Furthermore, the percentage of OP was found decreasing, while inorganic phosphorus (IP) of T(M) treatments increased, which indicated the transfromation trend from OP to IP (about 6.1% of OP was transformed to IP) in sediments. On the basis of this work, it can be conclueded that microorganisms can improve the transformation from OP to IP elevating the bioavailability and contribution of OP in the eutrophication process of Iakes.

[Exchange Fluxes and Coupling Relationship of Dissolved Inorganic Carbon and Dissolved Organic Carbon Across the Water-Sediment Interface in Lakes].

In this work, the exchange fluxes and coupling relationship of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) were investigated across the water-sediment interface in Lake Wuliangsuhai and Daihai by employing columnar simulation method. The results showed that the sediments in non-Phragmitescommunis area from Lake Wuliangsuhai functioned as the sources of DIC and DOC for overlying water, whereas the sediments from Lake Daihai as the sinks during the period of summer (90 days). In the experimental period, the average exchange rates of DIC and DOC were 71.07 mmol x (m2 x d)(-1) and 185.09 mmol x (m2 x d)(-1) in non-Phragmitescommunis area from Lake Wuliangsuhai, respectively; while in Lake Daihai, they were 155.75 mmol x (m2 x d)(-1) and -1478.08 mmol x (m2 x d)(-1) in shoal water zone, and -486.53 mmol x (m2 x d)(-1) and -1274.02 mmol x (m2 x d)(-1) in deep water zone, respectively. The coupling effects between DIC and DOC were governed by hydrobios, microbial uptake, abiotic and microbiological degradation in Lake Wuliangsuhai and in shoal water zone of Lake Daihai; while they were closely related to the coprecipitation process of CaCO3 and the fraction distribution of inorganic carbon in sediments in deep water zone of Lake Daihai. In summary, the sink or source functions of sediments could be considered as the results of synthetic action of lake types, offshore distance, geohydrochemistry and the fraction distribution of inorganic carbon.

[Manipulation of superduct, adduction, rotation for the treatment of shoulder dislocation].

OBJECTIVE: To study the mechanism and clinical effect of using the manipulatin of move, adduction, rotation method for the treatment of shoulder dislocation. METHODS: from January 2010 to March 2012,120 patients with shoulder dislocation admitted were randomly divided into treatment group and control group, 60 cases in each group. In the treatment group, there were 31 males and 29 females; In control group, there were 30 males and 30 females. In treatment group, 60 patients create their own "on the move, adduction, rotation manipulative treatment,the other 60 cases in control group used traditional restoration methods in wearing the traction treatment. The efficacy of two methods of treatment of shoulder dislocation were compared on reset process once successfully rate, the patient's level of pain (VAS). RESULTS: In treatment group, restoration once successfully were in 59 cases, improvement of the pain (VAS) values was 3.76 +/- 1.05, the results were excellent in 57 cases, good in 2, poor in 1,without concurrent fractures and nerve injury, without re-dislocation after 3 months. In control group, restoration once successfully were in 50 cases, improvement of pain (VAS) values was 5.67 +/- 1.15, the results were excellent in 45 cases, good in 7, poor in 8. The reset once successfully rate,improvement of VAS values and clinical effect in treatment group were better than that of control group. CONCLUSION: On the move, adduction, rotation method has advantages of more wearing traction with uniform force, work together to focus, saving time and effort, easy and convenient to avoid iatrogenic injury.

[Adsorption characteristic and form distribution of silicate in lakes sediments].

Taking surface sediments from the Wuliangsuhai Lake and Daihai Lake as adsorbent, the isothermal adsorption experiments of silicate on sediments were carried out and the adsorption behavior was explained by Langmuir, Freundlich and Temkin crossover-type equations, then the form distribution characters of silicate were studied after adsorption in this work. The results showed that the adsorption behavior of silicate on the two lakes sediments can be linear fitting in the lower concentration dose (< or = 3.00 mg x L(-1)); the sediments from the Wuliangsuhai Lake behaved adsorbing silicate while the sediments from the Daihai Lake behaved releasing silicate under the experimental dose; all of the Langmuir, Freundlich and Temkin crossover-type equations can be used to explain the adsorption behavior of silicate on the two lakes sediments, and the native adsorption silicate (NAS) and equilibrium silicate concentration (ESC(0)) calculated by the three equations could be used to explain the sink and source effects of the sediments from the two lakes; the silicate form distribution in the sediments after adsorption indicated that silicate adsorbed on particles were mainly added on the form of IEF-Si, CF-Si, IMOF-Si and OSF-Si, and the IMOF-Si and OSF-Si had important potential bioavailability.

[Characteristics of organic carbon forms in the sediment of Wuliangsuhai and Daihai Lakes].

The characteristics and differences of organic carbon forms in the sediments of the Wuliangsuhai and the Daihai Lakes with different eutrophication types were discussed in the present study. The results showed that the range of total organic carbon content (TOC) in Wuliangsuhai Lake was 4.50-22.83 g x kg(-1) with the average of 11.80 g x kg(-1). The range of heavy-fraction organic carbon content was 3.38-21.67 g x kg(-1) with the average of 10.76 g x kg(-1). The range of light-fraction organic carbon content was 0.46-1.80 g x kg(-1) with the average of 1.04 g x kg(-1); The range of ROC content was 0.62-3.64 g x kg(-1) with the average of 2.11 g x kg(-1), while the range of total organic carbon content in Daihai lake was 6.84-23.46 g x kg(-1) with the average of 14.94 g x kg(-1). The range of heavy-fraction organic carbon content was 5.27-22.23 g x kg(-1) with the average of 13.89 g x kg(-1). The range of light-fraction organic carbon content was 0.76-1.57 g x kg(-1). The range of ROC content was 1.54-7.08 g x kg(-1) with the average of 3.62 g x kg(-1). The results indicated that the heavy-fraction organic carbon was the major component of the organic carbon and plays an important role in the accumulation of organic carbon in the sediments of two Lakes. The content of light-fraction organic carbon was similar in the sediments of two lakes, whereas, the contents of total organic carbon and heavy-fraction organic carbon in the sediment of Wuliangsuhai Lake were less than those in the sediment of Daihai Lake, and the value of LFOC/TOC in the Wuliangsuhai Lake was larger than that in the Daihai Lake. The humin was the dominant component of the sediment humus, followed by fulvic acid in the two lakes. The values of HM/HS in the sediments of Wuliangsuhai lake range from 43.06% to 77.25% with the average of 62.15% and values of HM/HS in the sediments of Dahai lake range from 49.23% to 73.85% with the average of 65.30%. The tightly combined humus was the dominant form in the sediment humus of two lakes, and the followed was loosely combined humus. As a whole, the carbon storage of two lakes were all relatively stable, but the values of PQ, LFOC/TOC, the ratio of loosely to tightly combined humus and HA/FA revealed that, in the sediment of Wuliangsuhai, the humification degree of organic matter was lower than that of Daihai, while the activity of humus was higher than that of Daihai, thus the carbon storage is less stable than that of Daihai.

[Examination of silicate limitation of primary production by diatoms phytoplankton in the Daihai Lake].

The Daihai Lake (40 degrees 29'27"-40 degrees 37'6"N, 112 degrees 33'31"-112 degrees 46'40"E) is a typical inland lake in a semiarid region in Inner Mongolia, China. Based on the geochemistry character of biogenic silica (BSi) in the water-sediments system of the Daihai Lake, the theory of silicate limitation of Primary Production by Diatoms phytoplankton in the Daihai Lake are discussed in this work by interpreting the information of the BSi concentrations, horizontal and vertical distributions and the response relation between BSi and past environmental conditions. It is found that the concentration of Si is very low in overlying water while very high in the sediments. The spatial distribution patters of SiO3(2-) and BSi suggest the Si source of the lake. The geochemistry information of BSi is well archived in the lake sediment profiles, and the geochemistry information of BSi well responses to the past environmental conditions of the Daihai drainage basin. The ratios between Si, and C, N, P in the water-sediment system and the response relation between BSi and past environmental conditions indicate the main reasons for the theory of silicate limitation of Primary Production by Diatoms phytoplankton. Furthermore, the dominant factor for silicate limitation of Primary Production by Diatoms phytoplankton is different in different periods.

Species and distribution of rare earth elements in the Baotou section of the Yellow River in China.

This paper analyses the contents and species distributions of rare earth elements (REEs) in the water-suspended particulate-sediment system of the Baotou section of the Yellow River, China, with known anthropogenic REE input from industrial discharges. The major forms of REEs were suspended and dissolved in the mainstream and the tributaries of the Baotou section, respectively. The concentrations of the dissolved and suspended REEs had the same trends in the overlying water along the mainstream, which increased from the Seqi section (site A) to the mouth of the Sidaosha River (site D), reaching a maximum value at site D, and tending to decrease thereafter. The contents of REEs in sediment cores showed enrichment with light rare earth elements (LREEs). The bound to carbonates and to Fe-Mn oxides are the major forms of REE in the secondary phase and the REE exhibited LREE enrichment pattern and moderate Eu depletion in suspended particulates and surface sediments. The contents and species distributions of REEs in the water-suspended particulate-sediment system of the Baotou section suggest that the anthropogenic source of REEs from Baotou city have enhanced REE accumulation to the Baotou section. This information is important for predicting possible pollution resulting from anthropogenic REE input into rivers.

[Heavy metal adsorption research on different size fractions of sediment in the Baotou section of the Yellow River by using modified fractal dimension model].

The expression of surface fractal dimension (SFD) for size fractions of the Yellow River sediment was deduced. Based on the expression, the SFD value of different size fractions of the sediment was calculated. The SFD value of the sediment in the Baotou section of the Yellow River is 1.91, and the SFD value of the sediment smaller than 63 microm is 1.36, indicating strong ablation and separating ability of the Yellow River water. Using the modified fractal model, Freundlich model and Langmuir model to fit the data of heavy metal (Cu, Pb, Zn and Cd) adsorption, it is found that the modified fractal model is more available. And the adsorptive thermodynamics is better described by combining the modified fractal model and metastable equilibrium adsorption (MEA) theory. The variation extents of equilibrium adsorption capacity influenced by different grain size are ranked as Cu > Pb > Zn approximately equal to Cd. For each selected heavy metal, the higher initial concentration is, the stronger variation of adsorption capacity will be. The adsorptions of Cu and Pb are mainly associated with mineral composition of the sediment, while the adsorptions of Zn and Cd are mainly associated with physical characteristics of the sediment surface.

[Three dimensional induction of autologous mesenchymal stem cell and the effects on depressing long-term degeneration of tissue-engineering cartilage].

OBJECTIVES: To induce autologous bone marrow derived mesenchymal stem cell (aMSC) into chondrocyte, and to confirm the effects of 3 dimensional (3D) dynamic inducing in vitro and their long-term animal model repairing in vivo. METHODS: aMSC were separated from rabbits bone marrow aspirates, then respectively experienced 3D dynamic inducing in alginate drops in modified rotating wall bioreactor culture or in two dimensional (2D) inducing (culture flask) for 10 d. The induced cells were harvest and then mixed with fibrin sealant (FS) to repair rabbit knee femoral trochlea cartilage defects model. After 8, 12, 24, 48 weeks animals were euthanized. Gross appearance, histological appearances were examined. RESULTS: Flask culture groups showed a little chondrocyte differentiation, 3D inducing group showed obviously chondrocyte differentiation, improved collagen II and proteoglycan production. For 3D inducing ones in vivo, the cartilage defects were smoothly repaired by white translucent hard tissue with obvious hyaline-like cartilage histological appearance after 8, 12 weeks, and the defects boundary were hard to be identified with hyaline like cartilage with sustained histological appearance and score after 24, 48 weeks. For 2D ones in vivo, the cartilage defects were smoothly repaired after 8 weeks by hyaline like cartilage which showed accelerated degeneration after 24 weeks and lose cartilage performance completely after 48 weeks. CONCLUSIONS: 3D dynamic inducing may assist aMSC on differentiating into chondrocyte, improve its long-term in vivo repairing effects, and enlighten its further applications in tissue engineering cartilage.