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Abstract: A calix[4]arene functionized boron dipyrromethene (CBDP) was utilized as a charged fluorescent chromoionophore in ion optodes. The plasticized polyvinyl chloride (PVC) films containing CBDP and anion exchanger tridodecylmethylammonium chloride (TDMACl) exhibited reversible response to pH from 2 to 10. The fluorescence intensity of CBDP increases upon protonation due to the suppression of the photo induced electron transfer (PET) process between phenolate anion in calixarene and bodipy core. CBDP was applied to prepare anion and cation selective optodes based on co-extraction or ion-exchange mechanism. Optical sensors with the same fluorescent chromoionophore for four blood electrolytes, chloride ion, potassium ion, sodium ion, and calcium ion were prepared and allow the simultaneous measurements of multi analytes in biological samples by microplate reader. The concentrations of four electrolytes in rabbit plasma determined by the proposed optodes were consistent with the results obtained by conventional potentiometric methods, which suggests the possibilities for further applications of such optodes in clinical diagnosis. [Copyright &y& Elsevier]

A highly stable, long wavelength polarity sensitive probe, 8-nitrophenyl-3,5-dipiperidine-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (NPBDP), was developed for living cell imaging of intracellular lipid droplets by fluorescence microscopy. [ABSTRACT FROM AUTHOR]

In this paper, a fiber Bragg grating (FBG) temperature measurement method for intersatellite laser link is studied. Based on the analysis of the FBG temperature measurement method, the FBG sensing demodulation system is built to calibrate its wavelength and temperature parameters. The experimental data of temperature gradient monitoring are compared with the on-orbit real-time temperature data of a satellite's solar array measured by the thermistor to verify the temperature monitoring accuracy and stability of the FBG sensing demodulation system. The FBG sensing demodulation system and the thermistor temperature measurement system are compared under the same environmental conditions during the constant temperature period, the continuous heating phase and the natural cooling phase. The results show that during the constant temperature period, the temperature fluctuation range and standard deviation of the FBG sensing demodulation system are ±0.16 °C and 0.08 °C, respectively, which is significantly better than the performance of the thermistor temperature measurement system, whose temperature fluctuation range and standard deviation are ±5.92 °C and 1.08 °C, respectively. The temperature response speed of the former is significantly faster than that of the latter during the continuous heating phase and the natural cooling phase. [ABSTRACT FROM AUTHOR]

A novel Fabry–Perot (F–P) interferometer model based on the ultra-small gradient-index (GRIN) fiber probe is investigated. The signal arm of the F–P interferometer is organically combined with the ultra-small GRIN fiber probe to establish the theoretical model of the novel F–P interferometer. An interferometer experimental system for vibration measurements was built to measure the performance of the novel F–P interferometer system. The experimental results show that under the given conditions, the output voltage of the novel interferometer is 3.9 V at the working distance of 0.506 mm, which is significantly higher than the output voltage 0.48 V of the single-mode fiber (SMF) F–P interferometer at this position. In the range of 0.1–2 mm cavity length, the novel interferometer has a higher output voltage than an SMF F–P interferometer. Therefore, the novel F–P interferometer is available for further study of the precise measurement of micro vibrations and displacements in narrow spaces. [ABSTRACT FROM AUTHOR]

Abstract Differences in trophic status can lead to different water quality and sediment geochemistry characteristics, influencing antimony (Sb) mobility in sediments and its release into the water column. In this study, seasonal sampling was conducted in algal- and macrophyte-dominated zones of Lake Taihu, China. High-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were used to measure soluble Sb and DGT-labile Sb in the sediment-water profiles at a 4 mm vertical resolution. Results showed that total Sb in sediments from the two zones were on average 3.50 mg/kg and 3.21 mg/kg in the algal- and macrophyte-dominated zones, respectively, with the residual fraction being 96.3% and 95.4% of the total Sb contents in the two zones. In winter, soluble Sb concentrations in both zones increased. This was probably due to the oxidation of Sb(III) to Sb(V) by Mn and Fe oxides. In summer and autumn, soluble Sb concentrations in the algal-dominated region remained low. This is attributed to the dominance of insoluble Sb(III) in sediments under anoxic conditions under eutrophic environments. In contrast, soluble Sb concentrations in the macrophyte-dominated zone were significantly high in summer and were 4.15-times higher than limits set by the World Health Organization (WHO). This likely resulted from the photochemical and rhizospheric oxidation of insoluble Sb(III) compounds. It is suggested that Sb contamination in the sediment-water system of the macrophyte-dominated zone deserves additional attention. Highlights • Antimony (Sb) mobility differed in algae- and macrophyte-dominated (MD) regions. • Photochemical and rhizospheric oxidation increased Sb mobility in the MD region in summer. • Mn and Fe oxide oxidation increased Sb mobility in two regions during winter. • Sb mobilization manifested mainly in the transition between Sb(III) and Sb(V). [ABSTRACT FROM AUTHOR]

Abstract Studies of dredging effectiveness, especially the ones that last for several years, are scarce. In this study, we evaluated effectiveness of dredging performed for six years on controlling cobalt (Co), zinc (Zn), and nickel (Ni) contamination of sediments. High-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) methods were applied to analyze the non-dredged and post-dredging sediments. The soluble and DGT-labile Co and Ni content declined by 22% and 44% (soluble) and by 16% and 26% (labile) in April, July and October in the post-dredging region. In contrast, their concentrations increased by 105% and 9% (soluble) and 322% and 27% (labile) in January. These changes in the dredging effects were caused by the corresponding changes in the reducible and residual fractions of Co and the residual fraction of Ni in sediments in the dredged site, respectively. Soluble and DGT-labile Zn decreased on average by 23% and 29% in July and October and increased on average by 151% and 52% in April and January in the post-dredging region. The different Zn mobility in the post-dredging region was controlled by the reducible fraction of Zn. The results revealed positive influence of dredging engineering in summer, autumn and/or spring and negative one in winter. Therefore, an accurate assessment of dredging effectiveness should take its seasonal variation into consideration. Graphical abstract Image 1 Highlights • Dredging effects change during the different seasons as reflected by soluble and labile concentrations. • Dredging was most effective in April, July and October and had a negative effect in January. • Efficacy of Co was affected by the reducible and residual fractions in sediments. • Efficacies of Zn and Ni were respectively affected by reducible and residual fractions. [ABSTRACT FROM AUTHOR]

Fomesafen, a broad-spectrum herbicide with a long duration, is frequently applied in legume farmlands, causing severe damage to crop growth and the local environment. Sinorhizobium sp. W16 was a fomesafen-degrading rhizobium isolated from a soybean nodule. The pure culture assay revealed that strain W16 efficiently degraded 5 mg L−1 of fomesafen by 69 % over 7 days. Three metabolites were identified by liquid chromatography and time-of-flight mass spectrometry, revealing strain W16 was the first strain isolated to catalyze the cleavage of ether bond of fomesafen. The results of the pot experiment demonstrated that strain W16 colonizes the soybean rhizosphere for over 50 days and eliminates the inhibition of fomesafen on nitrogen fixation by increasing the activity of nitrogenase and stimulating the indigenous nitrogen-fixing microbes in the rhizosphere. The symbiotic relationship between strain W16 and legumes promotes soil fomesafen degradation rates by 29.17 %–57.87 %. This study provides valuable information about a novel fomesafen-degrading rhizobium with great potential for promoting the bioremediation of herbicide-contaminated farmland soil due to the development of symbiotic systems with legumes. [Display omitted] [ABSTRACT FROM AUTHOR]

• Peach gum colouring was associated with the total phenolic content that it contained. • Peach gum could be characterized by presence of metabolites and fungal communities. • Gummosis pathogenic fungus had a positive correlation with polyphenols in the gum. • Peach gum colouring may reflect defense response of plant against pathogenic fungi. • Hesperetin, naringenin and eriodictyol constituted the most abundant of flavonoids. In the present study, the differences in the antioxidant capability, metabolite composition and fungal diversity in peach gum with various colours were investigated. Metabolomics revealed that peach gum comprised many small-molecule metabolites (including primary and secondary metabolites), and most polyphenols (such as flavonoids and phenolic acids) showed a significantly positive relationship with the colour deepening, total phenol content and antioxidant capability. Using fungal diversity analysis, the abundance of five fungi at the genus level increased with peach gum colour deepening, and these fungi demonstrated a significantly positive relationship with two defense hormones (salicylic acid and abscisic acid) and most polyphenols (particularly flavonoids). The gummosis pathogenic fungus Botryosphaeria was among the five fungi, suggesting that peach gum colouring may reflect plant defense responses against pathogenic fungi. Additionally, the concentrations of 12 flavonoids in peach gum samples were detected based on LC-QQQ/MS, among which hesperetin, naringenin and eriodictyol were the most abundant. [ABSTRACT FROM AUTHOR]

• A new DGT can simultaneous 2-D imaging of three types of analytes by LA-ICP-MS. • The LA-ICP-MS method provides good analytical precision for 17 elements. • The hybrid PO-DGT sensor allows simultaneous 2-D imaging of O 2 and 17 elements. A new diffusive gradients in thin films technique (HR-ZCA DGT) was developed for simultaneous two-dimensional (2-D) chemical imaging of sulfides, metallic cations and oxyanions (S, Cd, Co, Fe, Cu, Mn, Ni, Pb, Zn, As, Cr, Mo, Sb, Se, V, P and W) at the submillimeter scale, combined with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis. A novel binding gel was prepared using a double precipitation method with AgI and zirconium oxide (Zr-oxide) deposited sequentially on a preformed Chelex-100 resin gel. A good linear relationship was observed (R 2>0.99) between mass accumulation of the 17 assessed elements on the binding gel and the corresponding standardized laser ablation signals (signals of elements divided by signals of internal standard 13C), proving the feasibility of LA-ICP-MS analysis. Good analytical precision (RSD<12 %) was achieved for all 17 elements. A hybrid sensor comprising the novel DGT binding gel overlying an O 2 planar optrode was then tested in sediments to evaluate the dynamics of O 2 and multiple elements. Results showed that the mobility of As, P and W were controlled by precipitation/dissolution processes with Fe/Mn oxides. V, Co, Ni, Zn, Mo, Cd and Sb were released at the sediment surface with the oxidation of iron sulfides. [ABSTRACT FROM AUTHOR]