Review of Seawater Fiber Optic Salinity Sensors Based on the Refractive Index Detection Principle.

This paper presents a systematic review of the research available on salinity optic fiber sensors (OFSs) for seawater based on the refractive index (RI) measurement principle for the actual measurement demand of seawater salinity in marine environmental monitoring, the definition of seawater salinity and the correspondence between the seawater RI and salinity. To further investigate the progress of in situ measurements of absolute salinity by OFSs, the sensing mechanisms, research progress and measurement performance indices of various existing fiber optic salinity sensors are summarized. According to the Thermodynamic Equation of Seawater-2010 (TEOS-10), absolute salinity is recommended for sensor calibration and measurement. Comprehensive domestic and international research progress shows that fiber-optic RI sensors are ideal for real-time, in situ measurement of the absolute salinity of seawater and have excellent potential for application in long-term in situ measurements in the deep ocean. Finally, based on marine environmental monitoring applications, a development plan and the technical requirements of salinity OFSs are proposed to provide references for researchers engaged in related industries.

3D image reconstruction of terahertz computed tomography at sparse angles by total variation minimization.

Continuous-wave terahertz computed tomography (THz-CT) is an important three-dimensional imaging method for probing the profile and inner properties of a sample's structure. We applied the total variation (TV) minimization iterative algorithm to squeeze 75% data acquisition time of THz-CT without the loss of reconstruction fidelity. The imaging system is built based on a 278.6 GHz avalanche diode source. A zero-order Bessel beam is generated by an axicon, for which the intensity profile remains essentially propagation invariant within the non-diffracting zone. The effectiveness of the proposed method is verified by using three optically opaque objects. The reconstruction results show that the TV-minimization algorithm can effectively suppress noise, artefacts, and shape distortion created in sparse angle reconstruction.

Spatio-temporal variation of soil microplastics as emerging pollutant after long-term application of plastic mulching and organic compost in apple orchards.

Microplastics (MPs) pollution in agroecosystems have aroused great alarm and widespread concern. However, the spatial distribution and temporal variation characteristics of MPs in apple orchards with long-term plastic mulching and organic compost input are still poorly understood. This study investigated MPs accumulation characteristics and vertical distribution after applying plastic mulch and organic compost in apple orchards for 3 (AO-3), 9 (AO-9), 17 (AO-17), and 26 (AO-26) years on the Loess Plateau. The clear tillage (no plastic mulching and organic composts) area was used as a control (CK). At a soil depth of 0-40 cm, AO-3, AO-9, AO-17, and AO-26 treatments increased the abundances of MPs, and the black fibers and fragments of rayon and polypropylene were dominant. In the 0-20 cm soil layer, the abundances of MPs increased with the treatment time; the abundance was 4333 pieces kg-1 after 26 years of treatment, gradually decreasing with soil depth. In different treatments and soil layers, the percentages of MPs <1000 µm were dominant (>50%). The AO-17 and AO-26 treatments significantly increased the MPs with the size of 0-500 µm at 0-40 cm and the abundances of pellets in 0-60 cm soil. In conclusion, the long-term (≥17 years) application of plastic mulching and organic composts increased the abundances of small particles at 0-40 cm, and plastic mulching contributed the most to MPs, while organic composts increased the complexity and diversity of MPs.

Long-term cover crops improved soil phosphorus availability in a rain-fed apple orchard.

The objective of this present study was to understand the distribution patterns of various forms of soil phosphorus (P) and the biotic and abiotic factors affecting the soil P fractions under long-term cover crops. Here, we investigated the characteristics of soil P forms, community structure of P-solubilizing bacteria (using 16S rRNA) and the related enzyme activity under clean tillage (CT), 14 years of white clover (WC, Trifolium repens L.) and orchard grass (OG, Dactylis glomerata L.) cover crops in a rain-fed apple orchard on the Weibei Loess Plateau, China. Relative to CT treatment, long-term cover crops enhanced the bioavailability of soil P by increasing the contents of total phosphorus (TP), microbial phosphorus (MBP), organic phosphorus (Po) and certain forms of inorganic phosphorus (e.g. Al-P, Ca2-P, Ca8-P and Fe-P) in the surface soil, in addition, WC treatment also increase the available P (AP) contents in the topsoil. A redundant analysis (RDA) showed that soil organic matter (SOM), NH4+-N and pH were the key environmental factors affecting the morphological changes of soil P. In addition, the effects of long-term cover crops on soil P forms were mainly concentrated in the topsoil, and the WC treatment had a greater impact on soil P composition than the OG treatment. Interestingly, long-term cover crops effectively increased the abundances of P-solubilizing bacteria, such as Streptomyces, Sphingomonas, Nocardioides and Haliangium, and enhanced the alkaline phosphatase (ALP) activity. Overall, long-term cover crops were an effective strategy to activate soil P as they improve the soil environment.

Genome-wide identification and expression profiling of the YUCCA gene family in Malus domestica.

The plant hormone auxin is essential for plant growth and development. YUCCA proteins catalyse the rate-limiting step for endogenous auxin biosynthesis. In this study, we isolated 20 MdYUCCA genes from apple genome. MdYUCCA6a, MdYUCCA8a, and MdYUCCA10a were expressed in most organs and could support whole plant basal auxin synthesis. MdYUCCA4a, MdYUCCA10b, and MdYUCCA11a expression indicated roles for these genes in auxin biosynthesis in vegetative organs. MdYUCCA2b, MdYUCCA11b, and MdYUCCA11d were mainly expressed in flower organs. High temperature induced the expression of MdYUCCA4a, MdYUCCA6a, MdYUCCA8a, and MdYUCCA10a, and down-regulated the expression of MdYUCCA2b and MdYUCCA6b. Dual-luciferase assay indicated that MdPIF4 could trans-activate the MdYUCCA8a promoter. Overexpression of MdYUCCA8a increased IAA content, increased stem height, enhanced apical dominance, and led to silique malformation. These results provide a foundation for further investigation of the biological functions of apple MdYUCCAs.

Knockdown of tripartite motif 59 (TRIM59) inhibits proliferation in cholangiocarcinoma via the PI3K/AKT/mTOR signalling pathway.

AIM: We analysed multiple microarray datasets in the Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) DataSets for messenger RNAs (mRNAs) whose expression is apparently increased in human cholangiocarcinoma (CCA) samples, compared with that in the adjacent normal biliary epithelial tissue. The results revealed that the expression of tripartite motif-containing 59 (TRIM59) was significantly increased in the CCA tissue samples. TRIM59 is a member of the tripartite motif (TRIM) protein family, which contains a highly conserved N-terminal-an interesting new gene (RING) domain regulating transcriptional factors and tumorigenesis. In the present study, we investigated the effects of TRIM59 expression on tumour growth in CCA. MATERIALS AND METHODS: After analyzing the microarray datasets from the TCGA database and GEO DataSets, we screened out 291 target genes, which are significantly overexpressed in CCA tissues, and TRIM59 was one of them. The quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry were performed to determine the expression of TRIM59 in CCA tissues (n = 65) and cell lines. Kaplan-Meier survival analysis was conducted to assess the prognosis of TRIM59 in patients with CCA. A specific siRNA (siRNA-1008) was used to inhibit the expression of TRIM59 in HCCC9810 and HUCCT1 cell lines. The effects of TRIM59 silencing on cell proliferation were assessed by the CCK-8, colony-formation, and EDU incorporation assays. Furthermore, the effects of TRIM59 knockdown on cell apoptosis and cell cycle were determined by flow cytometry. The in vivo effects were evaluated using a mouse tumorigenic model. Western blotting was also performed to verify the relationship between knockdown of TRIM59 and activation of the PI3K/AKT/mTOR pathway. RESULTS: TRIM59 was highly expressed in CCA tissues. The knockdown of TRIM59 obviously reduced the proliferation and colony formation abilities of CCA cells in vitro and in vivo. Furthermore, the cell apoptosis analysis results showed that TRIM59 silencing apparently promoted CCA cell apoptosis by the mitochondrial pathway. Our preliminary results indicate that the down-regulation of TRIM59 levels might restrict the PI3K/AKT/mTOR signalling pathway. CONCLUSIONS: Our study revealed that TRIM59 is up-regulated in CCA tissues and cell lines and promoted CCA cell proliferation, possibly by affecting the PI3K/AKT/mTOR signalling pathway.