Advances in the DNA Nanotechnology for the Cancer Biomarkers Analysis: Attributes and Applications.

The most commonly used clinical methods are enzyme-linked immunosorbent assay (ELISA) and quantitative PCR (qPCR) in which ELISA was applied for the detection of protein biomarkers and qPCR was especially applied for nucleic acid biomarker analysis. Although these constructed methods have been applied in wide range, they also showed some inherent shortcomings such as low sensitivity, large sample volume and complex operations. At present, many methods have been successfully constructed on the basis of DNA nanotechnology with the merits of high accuracy, rapid and simple operation for cancer biomarkers assay. In this review, we summarized the bioassay strategies based on DNA nanotechnology from the perspective of the analytical attributes for the first time and discussed and the feasibility of the reported strategies for clinical application in the future.

Isolation of differentially expressed sex genes in garden asparagus using suppression subtractive hybridization.

Garden asparagus (Asparagus officinalis L.) is a dioecious species whose male and female flowers are found in separate unisexual individuals. A region called the M-locus, located on a pair of homomorphic sex chromosomes, controls sexual dimorphism in asparagus. To date, no sex determining gene has been isolated from asparagus. To identify more genes involved in flower development in asparagus, subtractive hybridization library of male flowers in asparagus was constructed by suppression subtraction hybridization. A total of 107 expressed sequence tags (ESTs) were identified. BLASTX analysis showed that the library contained several genes that could be related to flower development. The expression patterns of seven selected genes believed to be involved in the development of asparagus male flower were further analyzed by semi-quantitative or real-time reverse-transcription polymerase chain reaction (RT-PCR). Results showed that AOEST4-5, AOEST12-40, and AOEST13-38 were strongly expressed in the male flower stage, whereas no transcript level of AOEST13-38 was detected in the female flower stage. The expression levels of AOEST13-87, AOEST13-92, AOEST13-40, and AOEST18-87 in the male flower stage were also higher than those in the female flower stage, although these transcripts were also expressed in other tissues. The identified genes can provide a strong starting point for further studies on the underlying molecular differences between the male and female flowers of asparagus.

[Comprehensive method for evaluating soil quality in cotton fields in Xinjiang, China]. / 新疆棉田土壤质量综合评价方法.

To evaluate the soil quality in the main cotton growing regions of Xinjiang, 11 soil quality indices were measured in representative locations: Hami, Bole, Changji, Shihezi, Aksu, Kashgar and Kuitun. The indices included soil pH, salt, organic matter, total N, available P and available K for soil physicochemical properties, and Cr, Cu, Zn, As, and Pb for soil heavy metal pollution. Based on these indices, a comprehensive soil quality index (SQI) was developed to analyze the soil quality in the cotton fields of Xinjiang. The results showed that the soils in Xinjiang's cotton fields were alkaline, with an average pH of 7.87. The soils were mildly saline, with an average salt content of 3.44 g·kg-1. Soil organic matter and total N concentrations were generally low, whereas available P and available K concentrations were relatively high. Soil available P concentrations were significantly higher than that of the second national soil survey, whereas soil pH, salt content, organic matter, and total N were less. Soil available K was greater in some regions but lower in others compared with the second national soil survey. The average heavy metal concentrations were as follows: Cr, 45.88 mg·kg-1; Cu, 40.66 mg·kg-1; Zn, 68.30 mg·kg-1; As, 12.88 mg·kg-1; and Pb, 16.68 mg·kg-1. These values were all below the national standards. However, the Cu, Zn, and As concentrations were greater than the background values in Xinjiang, indicating the accumulation of those elements in the soils. When the Nemerow comprehensive pollution index (PN) of heavy metals was less than 0.5, the comprehensive soil quality improved as the soil physicochemical properties improved. Soil organic matter, total N, Cu, Zn, As and Pb were the main variables affecting soil quality in the main cotton cropping regions of Xinjiang. The cotton growing areas in Xinjiang generally had medium soil quality. Changji and Kuitun had the highest SQI (0.52) whereas Aksu had the lowest value (0.31). Soil quality was generally highest in northern Xinjiang, followed by western area, and then southern area.

Astrocyte hepcidin is a key factor in LPS-induced neuronal apoptosis.

Inflammatory responses involving microglia and astrocytes contribute to the pathogenesis of neurodegenerative diseases (NDs). In addition, inflammation is tightly linked to iron metabolism dysregulation. However, it is not clear whether the brain inflammation-induced iron metabolism dysregulation contributes to the NDs pathogenesis. Herein, we demonstrate that the expression of the systemic iron regulatory hormone, hepcidin, is induced by lipopolysaccharide (LPS) through the IL-6/STAT3 pathway in the cortex and hippocampus. In this paradigm, activated glial cells are the source of IL-6, which was essential in the iron overload-activated apoptosis of neurons. Disrupting astrocyte hepcidin expression prevented the apoptosis of neurons, which were able to maintain levels of FPN1 adequate to avoid iron accumulation. Together, our data are consistent with a model whereby inflammation initiates an intercellular signaling cascade in which activated microglia, through IL-6 signaling, stimulate astrocytes to release hepcidin which, in turn, signals to neurons, via hepcidin, to prevent their iron release. Such a pathway is relevant to NDs in that it links inflammation, microglia and astrocytes to neuronal damage.

[Hyperspectral inversion of soil water and salt content in soils with different textures]. / ä¸åŒè´¨åœ°ç›æ¸åŒ–åœŸå£¤æ°´ç›å«é‡çš„é«˜å ‰è°±åæ¼”.

In order to monitor soil water and salt content of saline soil conveniently and quickly, this paper took the typical salinization irrigation district of Xinjiang as the research object, obtained the spectral curve of soil water and salt content by using portable spectrometers based on the hyperspectral technology, transformed the original spectra of soil using the first order differential, second order differential and continuum removal methods. The results showed that the transformation of the original spectral data was beneficial to fingerprint band extraction of soil properties, and the method was not same in soils with different textures. In loam soil, continuum removal analysis was the best method for extraction of characteristic bands when the soil water content was 0% and 10%, first order differential equations were the best method when the soil water content was 15%, and second order differential equations were the best method when the soil water content was 19%. In sandy soil, continuum removal analysis was the best method for extraction of characteristic bands when the soil water content was 0%, whereas second order differential equations were the best method when soil water content was 10%, 15% or 19%. The transformed data were screened for inversion models of soil water and salt content by using the partial least squares regression method. When thesalinity was < 6.38 mS·cm-1 in loam soil and < 5.94 mS·cm-1 in sandy soil, the decision coefficients (Rcal2), internal cross validation (Rcv2), and external validation (Rval2) were greater than 0.65 (P<0.05). When the soil moisture content was less than 16% in loam soil and 12% in sandy soil, the inversion accuracy of model was higher. The results would provide a reference threshold for si-multaneously monitoring soil water and salt content in salinized areas.

Analysis of transposable elements in the genome of Asparagus officinalis from high coverage sequence data.

Asparagus officinalis is an economically and nutritionally important vegetable crop that is widely cultivated and is used as a model dioecious species to study plant sex determination and sex chromosome evolution. To improve our understanding of its genome composition, especially with respect to transposable elements (TEs), which make up the majority of the genome, we performed Illumina HiSeq2000 sequencing of both male and female asparagus genomes followed by bioinformatics analysis. We generated 17 Gb of sequence (12×coverage) and assembled them into 163,406 scaffolds with a total cumulated length of 400 Mbp, which represent about 30% of asparagus genome. Overall, TEs masked about 53% of the A. officinalis assembly. Majority of the identified TEs belonged to LTR retrotransposons, which constitute about 28% of genomic DNA, with Ty1/copia elements being more diverse and accumulated to higher copy numbers than Ty3/gypsy. Compared with LTR retrotransposons, non-LTR retrotransposons and DNA transposons were relatively rare. In addition, comparison of the abundance of the TE groups between male and female genomes showed that the overall TE composition was highly similar, with only slight differences in the abundance of several TE groups, which is consistent with the relatively recent origin of asparagus sex chromosomes. This study greatly improves our knowledge of the repetitive sequence construction of asparagus, which facilitates the identification of TEs responsible for the early evolution of plant sex chromosomes and is helpful for further studies on this dioecious plant.