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[en] To study the expressions of TIMP-1 and MMP-9 in patients with chronic obstructive pulmonary disease (COPD) complicated with spontaneous pneumothorax, and their correlations with treatment outcomes. Methods: A total of 80 COPD patients complicated with spontaneous pneumothorax treated in our hospital from December 2015 to December 2017. The serum expressions of TIMP-1 and MMP-9 in 80 COPD patients complicated with spontaneous pneumothorax (COPD group) and 52 healthy volunteers (control group) were detected by ELISA. The correlations of TIMP-1 and MMP-9 expressions with arterial blood gas parameters as well as scores of MRC breathlessness scale and St. George’s Respiratory Questionnaire (SGRQ) were analyzed. Results: The serum expressions of TIMP-1 and MMP-9 of COPD group were significantly higher than those of control group (P<0.05), but the two groups had similar MMP-9/TIMP-1 ratios (P>0.05). For COPD group, TIMP-1 expression, MMP-9 expression, MMP-9/TIMP-1, Sa(O2) and p(O2) were not correlated (P>0.05). TIMP-1 expression was significantly positively correlated with MRC scale and SGRQ scores (P<0.05). Sa(O2), p(O2) and MRC scale score of low MMP-9 expression, low TIMP-1 expression and low MMP-9/TIMP-1 group were significantly improved compared with those of high MMP-9 expression, high TIMP-1 expression and high MMP-9/TIMP-1 group (P<0.05). MMP-9 expression, TIMP-1 expression or MMP-9/TIMP-1 was not correlated with improvement of SGRQ score. Pulmonary function improvement (Sa(O2) improvement rate ≥5% and/or p(O2) improvement rate ≥10%) was correlated with serum MMP-9 expression, baseline Sa(O2) and p(O2). Conclusion: Increase of serum TIMP-1 and MMP-9 expressions in COPD patients was correlated with symptoms and scores of quality of life, and the expressions were also correlated with short-term treatment reactivity. (author)
[en] Tetracentron sinense is an endangered tree in China in appendix III of CITES. The current status and dynamics of wild population of T. sinense are unknown, but are vital to its conservation. Diameter at breast height (or basal height for individuals <2.5 m) of all individuals of the T. sinense population in Meigu Dafengding Nature Reserve was investigated. Population size structure, time-specific life tables, survival analysis, and time series analysis were used to analyze the conservation status and dynamics of a natural population. The size structure of the population showed a spindle shape, with few younger individuals (including seedling and sapling) being present, and more middle-aged and aged individuals. The survival curve was a Deevey-type II. The mortality rate, killing power, mortality density, and hazard rate of the population all peaked in the 6th and 12th age-classes. In the first six age-classes, survival rate decreased monotonically, while the cumulative mortality rate rapidly increased, after which the change in trend became relatively gentle. The population size is expected to decrease rapidly in the future 6 and 12 age-classes. The result showed that the natural population was relatively stable, but was in the early stage of decline. The population size of T. sinense in Meigu Dafengding Reserve decreased during the early stage, stabilized in middle stage, and declined in the final stage. The lack of seedlings or saplings might reflect f bottleneck in the regeneration of T. sinense natural population. (author)
[en] By using the fixed monitoring sample sites of two re-vegetation modes in the opencast coal mine dump of Zhongmei Pingsuo as platform, we analyzed the number and the dynamic characteristics of the spatial distribution of all naturally regenerated seedlings in 2010 and 2014, sampled the corresponding soil, and investigated the correlation of two re-vegetation modes and soil quality parameters. Our results indicated that (1) the plant vegetation seedlings of SII site reduced and those of SI site significantly increased, which was opposite to saplings, and in 2014, the number of saplings in SII site substantially increased twice than the number in 2010; (2) from the respective of spatial distribution, the spatial map of seedlings and saplings showed that the their distribution of major species was consistent in 2010 and 2014. The dense and sparse areas in 2010 kept a similar distribution in 2014, which corresponds to the quantity of the species; (3) stepwise linear regression analysis between the survival rates of seedlings and saplings of various species and soil parameters indicated that the survival rate of elm seedlings significantly negatively correlated with soil moisture content and positively correlated with pH, and that the survival rate of locust saplings exhibited an extremely positive correlation to the organic matter content. (author)
[en] To provide good performance of spatial and energy measurement for the experiments at the HIRFL-CSR, a double-sided silicon strip detector (DSSD) has been designed as the pixel detector. Performance of the DSSD has been characterized in a vacuum chamber with the alpha source. The reverse leakage current of the DSSD is measured to be ∼3 nA/cm2⋅ 100 μm at the full depleted voltage and the energy resolution of each strip is better than 1%. Besides, the energy information of charge sharing events can be well measured. In this paper, the design, manufacture and performance characterization of the DSSD will be discussed.
[en] Adaptation to environmental changes is crucial for the viability of all organisms. In plants, cysteine proteases (CP) are vital proteolytic enzymes response to complex and volatile environmental factors. Previously, over-expression of a CP gene isolated from Salix matsudana (SmCP) was shown to improve the salt stress tolerance of Arabidopsis thaliana. However, the molecular mechanisms that underlie the enhanced salt stress tolerance of these over-expression lines remain uncharacterized. In this study, the transcriptome of transgenic Arabidopsis SmCP over-expression lines and wild type (WT) control (CT) plants was analyzed by RNA sequencing to identify genes associated with salt tolerance. The abundance level of selected differentially expressed genes was validated by quantitative real-time PCR analysis. The SmCP-transgenic line showed many transcriptomic changes under salt-stress conditions, including genes associated with alterations in the antioxidant environment and ion-transport capacity. Elucidation of the mechanism of salt stress resistance is important for utilization of SmCP for genetic improvement of commercial crops for tolerance to saline soil . (author)
[en] Highlights: • Precipitation of ω-Ti was revealed to account for the sub-Tg exothermic reaction of metastable β-type BMGCs. • Precipitation of isothermal ω-Ti significantly increases the modulus and hardness of the crystalline phase in β-type BMGCs. • Precipitation of isothermal ω-Ti does not alter the morphologies of the crystalline phase in β-type BMGCs. • Smaller modulus and lower hardness of the crystalline phase were substantiated to cause a lager plasticity of BMGCs. It is challenging to tailor the mechanical properties of in-situ formed β phases in Ti/Zr-based bulk metallic glass composites (β-type BMGCs) without changing the morphologies of the β phases. Recently, BMGCs containing metastable β-Ti/Zr phases (metastable β-type BMGCs) exhibit an exothermic reaction below the glass transition temperature (sub-Tg) of the glassy matrices during heating, however, the corresponding structural origin remains unclear. In this work, the precipitation of ω phase inside β phase was revealed to account for the sub-Tg exothermic event of the metastable Ti45.7Zr33Cu5.8Co3Be12.5 BMGC. The sub-Tg annealing of metastable β-type BMGCs causes the precipitation of nanometer-sized isothermal ω phase, which leads to a large increase in the modulus and hardness of the crystalline phase. This finding provides a novel route to tailor the modulus and hardness of the crystalline phases in BMGCs without changing their morphologies, including volume fractions, sizes, and distributions. On this basis, the influence of the modulus and hardness of the crystalline phase on mechanical properties of BMGCs was exclusively investigated. Our experimental results together with finite-element simulations proved that lower modulus and hardness of the crystalline phase benefit a larger plasticity of BMGCs.
[en] Trimeric surfactant modified montmorillonite immobilized in alginate beads (CA/3RenQ-Mt) sorbent was synthesized to simultaneously remove Cu2+ and methyl orange (MO) from aqueous solution. The CA/3RenQ-Mt was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), zeta potential analysis and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) analysis. The adsorption of Cu2+ and MO by CA/3RenQ-Mt was studied by the operational variables including contact time, pH and temperature. The results showed CA/3RenQ-Mt exhibited higher affinity to both Cu2+ and MO compared to sodium montmorillonite (Mt-Na), trimeric surfactant modified montmorillonite (3RenQ-Mt) or calcium alginate (CA). The pseudo-first-order kinetic model and Langmuir isotherm model were found to describe the MO adsorption well; the pseudo-second-order kinetic model and Freundlich isotherm model fitted well with the Cu2+ adsorption. The adsorption of MO onto CA/3RenQ-Mt is an endothermic spontaneous process, and ion-exchange was the dominant adsorption mechanism. Accordingly, the adsorption of Cu2+ on CA/3RenQ-Mt involved endothermic spontaneous chemical adsorption by means of coordination/chelation between Cu2+ and the oxygen atoms of carboxyl and hydroxyl groups of alginate. In general, CA/3RenQ-Mt can be applied as multifunctional adsorbent to remove heavy ions and anion dyes from aqueous solution.
[en] Aeromagnetic surveys using unmanned aerial vehicles (UAV) can be used in low-altitude detailed detection of small-scale magnetic anomalies and offers an auxiliary means for geomagnetic survey on land. However, excessive weight of the detection instruments and strong magnetic interference remain problems. To address them, an aeromagnetic system for a multi-rotor UAV based on the Overhauser sensor was designed. To ensure aeromagnetic surveys have high precision and are omnidirectional and fast, a miniaturized Overhauser sensor and a narrow-band tuned filter were designed and a short-time high-precision measurement method was proposed. Furthermore, the ridge regression is used to reduce the adverse effects of multicollinearity and enhance the stability of the compensation coefficient estimators. Both laboratory and flight tests were conducted. Overall, the results show that the static and dynamic noise is 0.029 nT, 0.041 nT, respectively, and the improvement ratio of aeromagnetic interference is 4.38 in the dynamic tests; a test of iron pipe detection was performed to verify the overall performance of the aeromagnetic system.
[en] Magnetohydrodynamic (MHD) waves play a significant role in the processes of the solar wind acceleration and the coronal heating. Based on the in situ measurements of the WIND spacecraft, some MHD waves in the quiet solar wind are identified with two criteria: (1) the correlation coefficients between velocity and magnetic field perturbations ( and ) and between thermal pressure and magnetic pressure perturbations (δpt and δpb), and (2) the dispersion relations of MHD waves. A preliminary statistics of those MHD modes is also achieved by selecting and analyzing the WIND data of 42,279 samples (45050.4 hr) in the 23rd solar cycle. It is found that the time fraction of Alfvén waves is 8% in this period, while the existence time of slow waves is 3.4%, and the fast wave is rare. The statistical result also shows that the Alfvén waves have a higher time fraction in fast solar wind, while the occurrence of slow waves is higher in moderate-speed solar wind. This work will provide more clues to understanding MHD activities in the solar wind, as well as the studies of solar wind acceleration and heating.