Silver Nanoparticle-Based Chemiluminescent Sensor Array for Pesticide Discrimination

In this work, we developed a simple, facile, and highly sensitive nanoparticle-based chemiluminescent (CL) sensor array for the discrimination of organophosphate and carbamate pesticides. This CL sensor array is based on simultaneous utilization of the triple-channel properties of the luminol-functionalized silver nanoparticle (Lum-AgNP) and H₂O₂ CL system containing CL intensity, the time for CL emissions to appear, and the time to reach the CL peak value, which are able to be measured via a single experiment. The triple-channel properties can be simultaneously altered after interaction with pesticides, producing distinct CL response patterns as “fingerprints” related to each specific pesticide, which was subjected to principal component analysis (PCA) to generate a clustering map. Using this sensor array, five organophosphate and carbamate pesticides, including dimethoate, dipterex, carbaryl, chlorpyrifos, and carbofuran, have been well-distinguished at a concentration of 24 μg/mL. A total of 20 unknown pesticide samples have been successfully identified with an accuracy of 95%. The simple strategy of this study is expected to promote the development of functionalized nanomaterial-based sensor arrays

Table_1_Super-resolution reconstruction, recognition, and evaluation of laser confocal images of hyperaccumulator Solanum nigrum endocytosis vesicles based on deep learning: Comparative study of SRGAN and SRResNet.docx

It is difficult for laser scanning confocal microscopy to obtain high- or ultra-high-resolution laser confocal images directly, which affects the deep mining and use of the embedded information in laser confocal images and forms a technical bottleneck in the in-depth exploration of the microscopic physiological and biochemical processes of plants. The super-resolution reconstruction model (SRGAN), which is based on a generative adversarial network and super-resolution reconstruction model (SRResNet), which is based on a residual network, was used to obtain single and secondary super-resolution reconstruction images of laser confocal images of the root cells of the hyperaccumulator Solanum nigrum. Using the peak signal-to-noise ratio (PSNR), structural similarity (SSIM) and mean opinion score (MOS), the models were evaluated by the image effects after reconstruction and were applied to the recognition of endocytic vesicles in Solanum nigrum root cells. The results showed that the single reconstruction and the secondary reconstruction of SRGAN and SRResNet improved the resolution of laser confocal images. PSNR, SSIM, and MOS were clearly improved, with a maximum PSNR of 47.690. The maximum increment of PSNR and SSIM of the secondary reconstruction images reached 21.7% and 2.8%, respectively, and the objective evaluation of the image quality was good. However, overall MOS was less than that of the single reconstruction, the perceptual quality was weakened, and the time cost was more than 130 times greater. The reconstruction effect of SRResNet was better than that of SRGAN. When SRGAN and SRResNet were used for the recognition of endocytic vesicles in Solanum nigrum root cells, the clarity of the reconstructed images was obviously improved, the boundary of the endocytic vesicles was clearer, and the number of identified endocytic vesicles increased from 6 to 9 and 10, respectively, and the mean fluorescence intensity was enhanced by 14.4% and 7.8%, respectively. Relevant research and achievements are of great significance for promoting the application of deep learning methods and image super-resolution reconstruction technology in laser confocal image studies.</p

Group statistical analysis in channel-wise CS from MAP to delta [HbO2] in different frequency interval.

<p>(A) channel-wise CS in frequency interval I (B) channel-wise CS in frequency interval III. Each column shows the CS mean and SD of a specific effective coupling interaction for different groups. The healthy, L–H and R–H groups are represented by different columns as illustrated by the legend in the figure. The line connectors and ‘*’ on the top of individual columns indicate that the difference between the two column distributions was statistically significant.</p

Configuration of source optodes, detector optodes and channels.

<p>(A) 24 channels corresponding to the 10/10 system. (B) Six cerebral cortex areas are separated by the rectangle frame as LPFC, RPFC, LPL, RPL, LOL and ROL. The ‘C’ represents channel.</p

Group-average coupling functions <i>q</i>_{<i>delta</i>[<i>HbO2</i>]}(<i>∅</i>_{<i>delta</i>[<i>HbO2</i>]},<i>∅</i>_<i>MAP</i>) between MAP and delta [HbO₂] oscillations in LPFC, RPFC, LPL, RPL, LOL and ROL in interval I.

<p>The coupling functions describe the functional influence from the MAP to delta [HbO₂] oscillator in different brain regions.</p

Group-average coupling functions <i>q</i>_{<i>delta</i>[<i>HbO2</i>]}(<i>∅</i>_{<i>delta</i>[<i>HbO2</i>]},<i>∅</i>_<i>MAP</i>) between MAP and delta [HbO₂] oscillations in LPFC, RPFC, LPL, RPL, LOL and ROL in interval IV.

<p>The coupling functions describe the functional influence from the MAP to delta [HbO₂] oscillator in different brain regions.</p

Effect of Tm3+ concentration on the emission wavelength shift in Tm3+-doped silica microsphere lasers

In this work, a Tm3+-doped solgel silica microsphere lasing at 2.0 mu m is reported. Microspheres with different Tm3+ concentrations are fabricated by overlaying different Tm3+ concentration solgel solutions on the surface of a pure silica microsphere resonator and then annealing the sample with a CO2 laser. Based on a traditional fiber taper-microsphere coupling method, single and multimode microsphere lasing in the wavelength range 1.8-2.0 mu m is observed if an 808 nm laser diode is used as a pump source. A relatively low threshold pumping power of 1.2 mW is achieved using this arrangement. This solgel method allows for an easy varying of the Tm3+ doping concentration. The observed laser output shifts to longer wavelengths when the Tm3+ doping concentration increases. This has been explained by the larger Tm absorption at shorter wavelengths. The ability to fabricate solgel co-doped silica glass microlasers represents a new generation of low threshold and compact infrared laser sources for use as miniaturized photonic components for a wide range of applications, including gas sensing and medical surgery. (c) 2018 Optical Society of America

Variation of DNA Methylome of Zebrafish Cells under Cold Pressure

<div><p>DNA methylation is an essential epigenetic mechanism involved in multiple biological processes. However, the relationship between DNA methylation and cold acclimation remains poorly understood. In this study, Methylated DNA Immunoprecipitation Sequencing (MeDIP-seq) was performed to reveal a genome-wide methylation profile of zebrafish (Danio rerio) embryonic fibroblast cells (ZF4) and its variation under cold pressure. MeDIP-seq assay was conducted with ZF4 cells cultured at appropriate temperature of 28°C and at low temperature of 18°C for 5 (short-term) and 30 (long-term) days, respectively. Our data showed that DNA methylation level of whole genome increased after a short-term cold exposure and decreased after a long-term cold exposure. It is interesting that metabolism of folate pathway is significantly hypomethylated after short-term cold exposure, which is consistent with the increased DNA methylation level. 21% of methylation peaks were significantly altered after cold treatment. About 8% of altered DNA methylation peaks are located in promoter regions, while the majority of them are located in non-coding regions. Methylation of genes involved in multiple cold responsive biological processes were significantly affected, such as anti-oxidant system, apoptosis, development, chromatin modifying and immune system suggesting that those processes are responsive to cold stress through regulation of DNA methylation. Our data indicate the involvement of DNA methylation in cellular response to cold pressure, and put a new insight into the genome-wide epigenetic regulation under cold pressure.</p></div