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BACKGROUND Simultaneous determination of thorium and potassium in geological samples can provide an important basis for exploration of radioactive mineral resources and evaluation of the natural radioactive ecological environment. The thorium in geological samples is usually digested by alkali fusion in traditional methods and determined by spectrophotometry. The traditional method is long, complex and not suitable for simultaneous determination of multiple elements. The potassium oxide in geological samples is digested by acid and generally determined by flame atomic absorption spectrometry, which requires diluting the solution with high concentration and has low detection efficiency. The determination of thorium and potassium oxide involves two different analytical methods and analytical instruments. OBJECTIVES To establish an analytical method for simultaneous determination of thorium and potassium oxide in geological samples. METHODS Chemical solvent which consists of nitric acid, hydrofluoric acid and perchloric acid, was identified according to the characteristics of the chemical composition of the geological samples. The geological samples were dissolved with this solvent and extracted with nitric acid. The content of thorium and potassium oxide in geological samples was measured by inductively coupled plasma-optical emission spectrometry (ICP-OES) at wavelengths of 401.913nm and 766.490nm, respectively by radial observation mode. RESULTS The correlation coefficient of the calibration curve of thorium and potassium oxide was greater than 0.999 and the detection limit of this method was 0.69μg/g and 0.008%, respectively. The measured value of the standard substance was consistent with the identified value, and the absolute logarithmic error of the two values was less than 0.1. The relative standard deviation was less than 6.0% and the recovery ranged from 96.0% to 104.0%. CONCLUSIONS This method meets the requirements of the testing quality management standard for geological and mineral laboratories.

In order to obtain optimized production technology of Castanopsis hystrix veneer, promote the high value utilization of Castanopsis hystrix plantation wood. In this study, Eucalyptus plywood was taken as the research object, the influences of glue and hot pressing process (glue spread, hot pressing temperature, hot pressing time and hot pressing pressure) on the moisture content, dipping peeling property and surface bonding strength of the Castanopsis hystrix veneer were investigated through orthogonal test method. Besides, the effects of different kinds of varnishes (nitrocellulose varnish, waterborne varnish and polyurethane varnish) on the color difference parameters and the physicochemical properties of the paint film (resistance to impact, wearability, adhesion, pencil hardness) of the veneer were also investigated. The results showed that the moisture content, dipping peeling property and surface bonding strength of the veneer could meet the requirements of the national standard. The optimal hot pressing process was 120 g/m² of glue, 180 °C of hot pressing temperature, 60 s of hot pressing time, and 0.4 MPa of hot pressing pressure. The impact resistance, abrasion resistance, and adhesion of the paint film coated with nitrocellulose varnish and polyurethane varnish could meet the requirements of the national standard. However, the abrasion resistance of the paint film coated with water-based varnish could not meet the requirements of the national standard, but it had the best adhesion and impact resistance. The Castanopsis hystrix wood has great development potential. [ABSTRACT FROM AUTHOR]

The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidiae), is a cryptic species complex comprising a minimum of 24 cryptic species. Some members of this complex are important agricultural pests, causing considerable damage to vegetable as well as ornamental and horticultural crops. Asia I, one of the cryptic species of B. tabaci, is widely distributed in Asia. One hundred and sixty mitochondrial cytochrome oxidase I (COI) sequences from eight countries have been analyzed to investigate the geographic origin and current genetic structure of this cryptic species. Sixty different haplotypes were identified, with levels of genetic distances ranging from 0.001 to 0.021. A sign of possible genetic differentiation emerges from the differential distribution of dominant haplotypes in Indonesia and India compared to China. A possible ancient separation between Asia I in India and Indonesia and secondary contact in China has been hypothesized. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to explore the root competitive effects of Ageratina adenophora and Setaria sphacelata, S. yunnanensis, Eupatorium fortunei, Chenopodium serotinum in monoculture and mixture, and the relative competitive abilities were evaluated. The results showed that the root length, superficial area and volume of A. adenophora in mixture were lower than in monoculture, but those of S. sphacelata were higher in mixture than in monoculture. The biomass of A. adenophora in mixture decreased by 77.1% and that of S. sphacelata increased by 80.4% compared with those in monoculture. The relative yield and competitive balance index of S. sphacelata were significantly higher than those of A. adenophora, and the relative yield was about 1.0, suggesting that the underground competitive ability of S. sphacelata was higher than A. adenophora. The root morphology of S. yunnanensis in monoculture and mixture was higher than those of A. adenophora, but the root morphology of two species in mixture was lower than in monoculture. The biomass of A. adenophora and S. yunnanensis in mixture decreased by 45.3% and 22.8% compared with those in monoculture, respectively. Competition effect parameters showed that A. adenophora was a mutual antagonism with S. yunnanensis. The root morphology of E. fortunei and A. adenophora in mixture showed no significant difference compared with that in monoculture. The biomass of A. adenophora and E. fortunei was lower than that in monoculture, respectively. Competition effect parameters showed that A. adenophora was a superior competitor. In the mixture of A. adenophora and C. serotinum, the root morphology parameters and competitive ability of A. adenophora were superior to those of C. serotinum. Above all, S. sphacelata is a preference plant material to control the A. adenophorum invasion and recover biodiversity in A. adenophorum invasion fields. [ABSTRACT FROM AUTHOR]

The competitive succession of plants community is determined by feedback of interaction between plant and soil microbe. In order to confirm the role of soil microbe in the population establishment and expansion of Ageratina adenophora Sprengel, a vicious invasive weed in china, the feedback effects of microorganisms in plant rhizosphere soil on growth of Ageratina adenophora Sprengel and 2 native plants were compared, Eupatorium lindleyanum DC. and Setaira viridis (L.) Beauv, by conducting the greenhouse pot experiment. A. adenophora and native plant soil were sterilized, added fungicide and no treated (control groups), respectively. The results showed that soil microorganisms in plant rhizosphere can produce a direct positive feedback effects on the growth of plants. The biomass of A. adenophora, E. lindleyanum and S. viridis decreased significantly after adding fungicide or sterilizing. There were no significant difference of AMF root colonization of E. lindleyanum and S. viridis between A. adenophora soil and native plant soil in control group, but AMF root colonization of E. lindleyanum and S. viridis in A. adenophora soil increased by 81.02% and 89.7% compared to native plant soil after adding fungicide, respectively. The PLFAs results also showed that the soil microbe communities of A. adenophora and native plants were apparently different. It was considered that the invasive plant, A. adenophora produced positive feedback to itself by affecting the soil microbe communities and function in invaded habits, subsequently contributing to its growth and population expansion. [ABSTRACT FROM AUTHOR]

Long non-coding RNA (lncRNA) is a variety of the human transcriptome that does not code for proteins and plays an important role in the development and progression of multiple solid malignant tumors. However, the roles of lncRNAs in the development of pancreatic ductal adenocarcinoma (PDAC) remain unknown. In this study, we investigated the expression patterns of lncRNAs in three PDAC tumor samples (T) relative to those of matched adjacent non-tumor tissues (N) via a microarray with 30,586 lncRNA probes and 26,109 mRNA probes. The lncRNA microarray revealed 27,279 lncRNAs in PDAC samples, of which 2,331 were significantly upregulated (P<0.05; T/N>2.0) and 1,641 were downregulated (P<0.05; N/T>2.0) compared with matched adjacent non-tumor samples. In addition, 19,995 mRNAs were detected, of which 1,676 were significantly upregulated (P<0.05; T/N>2.0) and 1,981 were downregulated (P<0.05; N/T>2.0). Pathway analysis indicated that 41 pathways corresponded to upregulated transcripts and 25 pathways corresponded to downregulated transcripts (P-value cut-off is 0.05). Gene ontology (GO) analysis showed that the highest enriched GOs targeted by upregulated and downregulated transcripts were tissue homeostasis. The validation results from quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis and microarray analysis were consistent. Furthermore, the expression level of long intergenic non-coding RNA HOTAIRM1 was upregulated in 12 PDAC tissues samples compared with matched adjacent non-tumor samples by qRT-PCR. The results showed that the lncRNA and mRNA expression profiles differed significantly between the PDAC tissues and their adjacent non-tumor tissues, and the revelation of an association between HOTAIRM1 expression and PDAC is especially noteworthy. These findings may provide new potential molecular markers for diagnosis and treatment of PDAC.

A field experiment was conducted to explore the root competitive effects of Ageratina adenophora and Setaria sphacelata, S. yunnanensis, Eupatorium fortunei, Chenopodium serotinum in monoculture and mixture, and the relative competitive abilities were evaluated. The results showed that the root length, superficial area and volume of A. adenophora in mixture were lower than in monoculture, but those of S. sphacelata were higher in mixture than in monoculture. The biomass of A. adenophora in mixture decreased by 77.1% and that of S. sphacelata increased by 80.4% compared with those in monoculture. The relative yield and competitive balance index of S. sphacelata were significantly higher than those of A. adenophora, and the relative yield was about 1.0, suggesting that the underground competitive ability of S. sphacelata was higher than A. adenophora. The root morphology of S. yunnanensis in monoculture and mixture was higher than those of A. adenophora, but the root morphology of two species in mixture was lower than in monoculture. The biomass of A. adenophora and S. yunnanensis in mixture decreased by 45.3% and 22.8% compared with those in monoculture, respectively. Competition effect parameters showed that A. adenophora was a mutual antagonism with S. yunnanensis. The root morphology of E. fortunei and A. adenophora in mixture showed no significant difference compared with that in monoculture. The biomass of A. adenophora and E. fortunei was lower than that in monoculture, respectively. Competition effect parameters showed that A. adenophora was a superior competitor. In the mixture of A. adenophora and C. serotinum, the root morphology parameters and competitive ability of A. adenophora were superior to those of C. serotinum. Above all, S. sphacelata is a preference plant material to control the A. adenophorum invasion and recover biodiversity in A. adenophorum invasion fields.