Search Results

You are looking at 1 - 10 of 16 items for

  • Author or Editor: L. Ye x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

This is the first systematic study of air pollution from heavy metals and other trace elements throughout several industrialized areas and national parks of Eastern Romanian Carpathians using the moss biomonitoring technique. Samples ofHylocomium splendens collected at 120 sites were analyzed by epithermal neutron activation analysis at the pulsed fast reactor IBR-2 at JINR, Dubna, for a wide range of elements including heavy metals and rare earths (Na, Mg, Al, Cl,K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni (by (n,p) reaction), Cu, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Ag, Sn, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Yb, Hf, Ta, W, Au, Th, and U). Copper, lead and cadmium were determined by AAS. Certified Reference Standards of mosses produced for interlaboratory comparisons in the European moss-survey 1995 were used to ensure the quality of the measurements. To present results in the form of coloured contour maps the geographical information system GIS-INTEGRO was used. The regional extent of pollution with specific metals was determined. Results reported are well consistent with those obtained in numerous recent projects carried out in Germany, the Netherlands, Poland, Bulgaria and other countries.

Restricted access

Abstract

In this study, the ability of microRNA-1906 (miR-1906) to attenuate bone loss in osteoporosis was evaluated by measuring the effects of a miR-1906 mimic and inhibitor on the cellular toxicity and cell viability of MC3T3‐E1 cells. Bone marrow-derived macrophage (BMM) cells were isolated from female mice, and tartrate-resistant acid phosphatase signalling was performed in miR-1906 mimic-treated, receptor-activated nuclear factor kappa-B (NF-κB) ligand (RANKL)-induced osteoclasts. In-vivo, osteoporosis was induced by ovariectomy (OVX). Rats were treated with 500 nmol/kg of the miR-1906 mimic via intrathecal administration for 10 consecutive days following surgery. The effect of the miR-1906 mimic on bone mineral density (BMD) in OVX rats was observed in the whole body, lumbar vertebrae and femur. Levels of biochemical parameters and cytokines in the serum of miR-1906 mimic-treated OVX rats were analysed. The mRNA expression of toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), p-38 and NF-κB in tibias of osteoporotic rats (induced by ovariectomy) was observed using quantitative reverse-transcription polymerase chain reaction. Treatment with the miR-1906 mimic reduced cellular toxicity and enhanced the cell viability of MC3T3‐E1 cells. Furthermore, osteoclastogenesis in miR-1906 mimic-treated, RANKL-induced osteoclast cells was reduced, whereas the BMD in the miR-1906 mimic-treated group was higher than in the OVX group of rats. Treatment with the miR-1906 mimic also increased levels of biochemical parameters and cytokines in the serum of ovariectomised rats. Finally, mRNA expression levels of TLR4, MyD88, p-38 and NF-κB were lower in the tibias of miR-1906 mimic-treated rats than in those of OVX rats. In conclusion, the miR-1906 mimic reduces bone loss in rats with ovariectomy-induced osteoporosis by regulating the TLR4/MyD88/NF‐κB pathway.

Restricted access

Abstract  

The two complexes of [Ln(CA)3bipy]2 (Ln = Tb and Dy; CA = cinnamate; bipy = 2,2′-bipyridine) were prepared and characterized by elemental analysis, infrared spectra, ultraviolet spectra, thermogravimetry and differential thermogravimetry techniques. The thermal decomposition behaviors of the two complexes under a static air atmosphere can be discussed by thermogravimetry and differential thermogravimetry and infrared spectra techniques. The non-isothermal kinetics was investigated by using a double equal-double steps method, the nonlinear integral isoconversional method and the Starink method. The mechanism functions of the first decomposition step of the two complexes were determined. The thermodynamic parameters (ΔH , ΔG and ΔS ) and kinetic parameters (activation energy E and the pre-exponential factor A) of the two complexes were also calculated.

Restricted access

Abstract  

To evaluate the potentiality of the blue-green algae Spirulina platensis as a matrix for the production of Se-containing pharmaceuticals, the background levels of 31 major, minor and trace elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni using (n,p) reaction), As, Br, Zn, Rb, Mo, Ag, Sb, I, Ba, Sm, Tb, Tm, Hf, Ta, W, Au, Hg, Th were determined in Spirulina platensis biomass by means of epithermal neutron activation analysis. The possibility of the purpose-oriented incorporation of Se into Spirulina platensis biomass was demonstrated. The polynomial dependence of the Se accumulation on nutritional medium loading was revealed. The analytical technique used allows to control the amount of toxic elements in algae Spirulina platensis. Based on this study, a conclusion of the possibility to use Spirulina platensisas a matrix for the production of Se-containing pharmaceutical was drawn.

Restricted access

The common wheat line, YW243, developed in our research group, was tested for the resistances of barley yellow dwarf virus (BYDV), powdery mildew (Pm) and stripe rust in field, and was analyzed by molecular markers for convenient trace of the resistant genes in breeding. Genomic in situ hybridization (GISH) analysis and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) assay further demonstrated that YW243 was a homozygous multiple translocation line of Triticum aestivum, Thinopyrum intermedium and Secale cereale (T7DS·7DL-7XL & 1BL·1RS). The disease resistance test and marker analysis showed that YW243 carried seven resistance genes to the three diseases, including Bdv2 to BYDV on 7DL-7XL, Pm4 to powdery mildew on 2AL, Yr2, Yr9, Sr 31 and Lr26 and a new Yr to stripe rust on 7B, 1BL, 1RS and 2BL. Restriction fragment length polymorphism (RFLP) markers Xpsr687 and Xwg380 , sequence tagged site (STS) marker STS 1700 , simple sequence repeat (SSR) markers Xgwmc364 and Xgwm582 , SSR markers Xgwm388 and Xgwm501 can be used as diagnostic tools to track Bdv2, Pm4, Yr2, Yr9 and Yr in YW243 , respectively; and two amplified fragment length polymorphism (AFLP) markers M54E63 - 700 and M54E64 - 699 can also be used to select Yr in YW243 .

Restricted access

Although significant progress has been made on Agrobacterium -mediated wheat transformation, the current methodologies use immature embryos as recipient tissues, a process which is labor intensive, time consuming and expensive. In this study, we have managed to develop an Agrobacterium -based transformation scheme using explants derived from mature embryos. Based on transient expression of β -glucuronidase (GUS) marker, mature embryo halves prepared from freshly imbibed seeds were generally most susceptible to Agrobacterium -mediated T-DNA transfer. According to the results of callus induction and shoot production, Yumai 66 and Lunxuan 208 showed higher selection and regeneration efficiency than Bobwhite. In line with this finding, fertile T 0 transgenic plants were most readily obtained for both spring and winter wheat when mature embryo halves were used for co-inoculation by Agrobacterium cells. The presence of the antibiotic selection marker ( nptII , encoding neomycin phosphotransferase II) in the T 0 plants was revealed by both genomic PCR amplification and the enzyme-linked immunosorbent assay (ELISA). Additional analysis showed that the transgene was stably inherited from the two different generations and segregated normally among the T 1 progenies. Further development along this line will raise the efficiency of wheat transformation and increase the use of this approach in the molecular breeding of wheat crop.

Restricted access

Abstract  

The recombination of hydrogen and oxygen in technical gaseous waste of nuclear power plants in enlarged scale experiment has been studied on the basis of our previous work.1 The catalyst and its best operating conditions for recombination of hydrogen and oxygen determined in a small scale experiment were demonstrated and tested. The results show that the data obtained in an enlarged scale experiment agreed well with that of in a small scale test. The recombination rate of H2 and O2 was higher than 98.3% and 99.98% respectively. After recombination, the residual concentrations of H2 and O2 in waste gas were O2<3 ppm, H2<400 ppm. The Pd-Al2O3 catalyst and operating conditions determined for gaseous waste processing of nuclear power plants were satisfactory.

Restricted access

Abstract  

The complex of [Nd(BA)3bipy]2 (BA = benzoic acid; bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR spectra, single crystal X-ray diffraction, and TG/DTG techniques. The crystal is monoclinic with space group P2(1)/n. The two–eight coordinated Nd3+ ions are linked together by four bridged BA ligands and each Nd3+ ion is further bonded to one chelated bidentate BA ligand and one 2,2′-bipyridine molecule. The thermal decomposition process of the title complex was discussed by TG/DTG and IR techniques. The non-isothermal kinetics was investigated by using double equal-double step method. The kinetic equation for the first stage can be expressed as dα/dt = A exp(−E/RT)(1 − α). The thermodynamic parameters (ΔH , ΔG , and ΔS ) and kinetic parameters (activation energy E and pre-exponential factor A) were also calculated.

Restricted access

Abstract  

A ternary binuclear complex of dysprosium chloride hexahydrate with m-nitrobenzoic acid and 1,10-phenanthroline, [Dy(m-NBA)3phen]2·4H2O (m-NBA: m-nitrobenzoate; phen: 1,10-phenanthroline) was synthesized. The dissolution enthalpies of [2phen·H2O(s)], [6m-HNBA(s)], [2DyCl3·6H2O(s)], and [Dy(m-NBA)3phen]2·4H2O(s) in the calorimetric solvent (VDMSO:VMeOH = 3:2) were determined by the solution–reaction isoperibol calorimeter at 298.15 K to be
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta_{\text{s}} H_{\text{m}}^{\theta }$$ \end{document}
[2phen·H2O(s), 298.15 K] = 21.7367 ± 0.3150 kJ·mol−1,
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta_{\text{s}} H_{\text{m}}^{\theta }$$ \end{document}
[6m-HNBA(s), 298.15 K] = 15.3635 ± 0.2235 kJ·mol−1,
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta_{\text{s}} H_{\text{m}}^{\theta }$$ \end{document}
[2DyCl3·6H2O(s), 298.15 K] = −203.5331 ± 0.2200 kJ·mol−1, and
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta_{\text{s}} H_{\text{m}}^{\theta }$$ \end{document}
[[Dy(m-NBA)3phen]2·4H2O(s), 298.15 K] = 53.5965 ± 0.2367 kJ·mol−1, respectively. The enthalpy change of the reaction was determined to be
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta_{\text{r}} H_{\text{m}}^{\theta } = 3 6 9. 4 9 \pm 0. 5 6 \;{\text{kJ}}\cdot {\text{mol}}^{ - 1} .$$ \end{document}
According to the above results and the relevant data in the literature, through Hess’ law, the standard molar enthalpy of formation of [Dy(m-NBA)3phen]2·4H2O(s) was estimated to be
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta_{\text{f}} H_{\text{m}}^{\theta }$$ \end{document}
[[Dy(m-NBA)3phen]2·4H2O(s), 298.15 K] = −5525 ± 6 kJ·mol−1.
Restricted access

Abstract  

Photoinitiating behaviors of oligo(α-aminoketones) (OAK) macrophotoinitiator containing aminoalkylphenone group on free-radical photopolymerization had been investigated by differential photo-calorimetry (DPC). The macrophotoinitiator showed comparative performance with those commercial photoinitiators with lower molecular mass. The effect of photoinitiator concentrations and UV intensity on the polymerization rate was investigated, and the value of exponential factor was found to be 0.5 at the beginning of polymerization, suggesting that the photopolymerization initiated by OAK followed biradical termination mechanism. Photosensitizer isopropyl thioxanthone (ITX) and oxygen severely restricted the polymerization in these systems. Photoinitiators with lower molecular mass showed higher reactivity than those with higher molecular mass.

Restricted access