[Monitoring and evaluation of eco-environmental quality of lake basin regions in Central Yunnan Province, China]. / 滇中湖泊流域生态环境质量监测与评价.

The basin region of nine highland lakes plays an important role in the economic development of Yunnan Province, in which, the basin region of the five lakes (Dianchi, Fuxianhu, Xingyunhu, Qiluhu and Yangzonghai Lake, hereinafter was called Five-lake Basin) locating in the central region of Yunnan Province is the most active economic and social development area of industry, agriculture and tourism, closely related to the eco-environmental quality of the whole basin. In this study, the eco-environmental quality of the Five-lake Basin from 1988 to 2018 was monitored and evaluated based on remote sensing ecological index (RSEI). The results showed that although the eco-environmental quality in this area had a trend of turning better from 1988 to 2018, with the mean value of RSEI increasing from 0.368 to 0.481, whereas the overall eco-environmental quality of the basin was poor. The area with improved eco-environmental quality accounted for 57.6%, which was mainly distributed in the mountains between lakes, while the declining area was mainly the flat area around the lake. The eco-environmental quality of Dianchi Lake, Fuxianhu Lake, and Yangzonghai Lake was improved during the study period, but the eco-environmental quality of Qiluhu Lake and Xingyunhu Lake deteriorated obviously in the last 10 years. The change of eco-environmental quality in each lake was consistent with the change of water quality. In the future, the improvement of eco-environmental quality needs more social attention and government investment.

[CCR7 silence by siRNA inhibits proliferation, invasion and promotes apoptosis of human MG63 osteosarcoma cells].

Objective To investigate the effect of siRNA-mediated chemokine receptor 7 (CCR7) silence on the proliferation, migration, invasion and apoptosis of human MG-63 osteosarcoma cells. Methods The study designed and synthesized siRNA targeting CCR7 (CCR7-siRNA). After MG63 cells were transfected with CCR7-siRNA, the expression of CCR7 was identified by Western blotting; cell apoptosis was detected by annexinV-FITC/PI double staining combined with flow cemetery; cell proliferation was tested by MTT assay; and cell migration and invasion abilities were examined by TranswellTM migration/invasion assays. Results CCR7 expression in MG63 cells was significantly inhibited after transfected with CCR7-siRNA. At the same time, cell proliferation, migration and invasion abilities were distinctly suppressed, and cell apoptosis rate increased. Conclusion Down-regulating CCR7 expression in MG63 cells could apparently inhibit cell proliferation, migration and invasion abilities of MG63 cells, and also induce cell apoptosis.

[Estrogen exerts anti-inflammatory effects by inhibiting NF-κB pathway through binding with estrogen receptor ß on synovicytes of osteoarthritis].

Objective To investigate the mechanism of estrogen's anti-inflammatory effects on synovial cells during the pathogenic process of osteoarthritis. Methods We isolated synovicytes from synovium tissues and identified the cells with flow cytometry. Then we detected the expression level of estrogen receptor ß (ERß) in synovicytes with immunofluorescence staining. The synovicytes were divided into control group, group pretreated with 10 ng/mL IL-1ß, group pretreated with 10 ng/mL IL-1ß and 10-7 mol/L estrogen, group pretreated with 10 ng/mL IL-1ß, 10-7 mol/L estrogen and specific antagonist of ERß, 10-5 mol/L tetrahydrocannabinol (THC). Thirty-six hours later, we observed the mRNA and protein levels of IκBα, phospho-IκBα (p-IκBα) and IL-6. Results Immunofluorescence staining showed the high expression level of ERß in synovicytes. In IL-1ß treated cells, IL-6 mRNA and protein level, IκBα mRNA and p-IκBα protein levels were elevated compared with the control group, while IκBα protein level declined. In the cells pretreated with IL-1ß and estrogen, the mRNA and protein levels of IL-6, IκBα and p-IκBα were inhibited compared with IL-1ß treated cells. THC blocked the effects of estrogen on the IL-1ß and estrogen treated cells, and the mRNA and protein levels of IL-6, IκBα and p-IκBα had no significant difference compared with IL-1ß treated cells. Conclusion The estrogen can restrain the activation of NF-κB pathway in synovicytes via ERß, thus playing a vital role in anti-inflammation.

Direct Reduction of Graphene Oxide by Ni Foam as a High-Capacitance Supercapacitor Electrode.

Three dimensional reduced graphene oxide (RGO)/Ni foam composites are prepared by a facile approach without using harmful reducing agents. Graphene oxide is reduced by Ni foam directly in its aqueous suspension at pH 2 at room temperature, and the resultant RGO sheets simultaneously assemble around the pillars of the Ni foam. The RGO/Ni foam composite is used as a binder-free supercapacitor electrode and exhibits high electrochemical properties. Its areal capacitance is easily tuned by varying the reduction time for different RGO loadings. When the reduction time increases from 3 to 15 days, the areal capacitance of the composite increases from 26.0 to 136.8 mF cm(-2) at 0.5 mA cm(-2). Temperature is proven to be a key factor in influencing the reduction efficiency. The composite prepared by 5 h reduction at 70 °C exhibits even better electrochemical properties than its counterpart prepared by 15 day reduction at ambient temperature. The 5 h RGO/Ni foam composite shows an areal capacitance of 206.7 mF cm(-2) at 0.5 mA cm(-2) and good rate performance and cycling stability with areal capacitance retention of 97.4% after 10000 cycles at 3 mA cm(-2). Further extending the reduction time to 9 h at 70 °C, the composite shows a high areal capacitance of 323 mF cm(-2) at 0.5 mA cm(-2). Moreover, the good rate performance and cycling stability are still maintained.

Electrospun PCL/PLA/HA based nanofibers as scaffold for osteoblast-like cells.

Polycaprolactone (PCL), poly (lactic acid) (PLA) and hydroxyapatite (HA) are frequently used as materials for tissue engineering. In this study, PCL/PLA/HA nanofiber mats with different weight ratio were prepared using electrospinning. Their structure and morphology were studied by FTIR and FESEM. FTIR results demonstrated that the HA particles were successfully incorporated into the PCL/PLA nanofibers. The FESEM images showed that the surface of fibers became coarser with the introduction of HA nanoparticles into PCL/PLA system. Furthermore, the addition of HA led to the decreasing of fiber diameter. The average diameters of PCL/PLA/HA nanofiber were in the range of 300-600 nm, while that of PCL/PLA was 776 +/- 15.4 nm. The effect of nanofiber composition on the osteoblast-like MC3T3-E1 cell adhesion and proliferation were investigated as the preliminary biological evaluation of the scaffold. The MC3T3-E1 cell could be attached actively on all the scaffolds. The MTT assay revealed that PCL/PLA/HA scaffold shows significantly higher cell proliferation than PCL/PLA scaffolds. After 15 days of culture, mineral particles on the surface of the cells was appeared on PCL/PLA/HA nanofibers while normal cell spreading morphology on PCL/PLA nanofibers. These results manifested that electrospun PCL/PLA/HA scaffolds could enhance bone regeneration, showing their marvelous prospect as scaffolds for bone tissue engineering.

Influence of cross-sectional design and dimension on mechanical behavior of nickel-titanium instruments under torsion and bending: a numerical analysis.

INTRODUCTION: The aim of this study was to examine the influence of the cross-sectional configuration and dimensions (size and taper) on the torsional and bending behavior of nickel-titanium rotary instruments, taking into account the nonlinear mechanical properties of material. METHODS: Ten cross-sectional configurations, square, triangular, U-type, S-type (large and small), convex-triangle, and 4 proprietary ones (Mani NRT and RT2, Quantec, and Mtwo), were analyzed under torsion or bending by using a 3-dimensional finite element method. The von Mises stresses were correlated with the critical values for various phases of the nickel-titanium material. RESULTS: Different loading conditions led to unequal patterns of stress distribution. Increasing the applied torque or bending angle resulted in a rise in the corresponding stresses in the instrument. Favorable stress distribution without dangerous stress concentration was observed if the material was undergoing superelastic transformation at that applied load. The ultimate strength of the material was not exceeded when the instrument was bent up to a 50-degree curvature. On the other hand, when a torsional moment of greater than 1.0 N*mm was applied, the maximum stresses developed in some designs would exceed the ultimate strength of the material. Little variation in the von Mises stresses was observed for instruments of different nominal sizes and tapers on bending to similar extent. CONCLUSIONS: The cross-sectional design has a greater impact than taper or size of the instrument on the stresses developed in the instrument under either torsion or bending. Certain cross-sectional configurations are prone to fracture by excess torsional stresses.