Polymer Microbead-Based Surface Enhanced Raman Scattering Immunoassays

The high sensitive surface enhanced Raman scattering (SERS) makes its broad utilization in biomolecule recognition. In this study, a highly specific polymer microbead-based Raman/SERS immunoassay system is developed and evaluated. Different analytical techniques such as UV–visible spectrophotometry, transmission electron microscopy, Raman spectrometry, and fluorescence microscopy have been employed to investigate the feasibility and effectiveness of gold nanoparticles (AuNPs) and polymer microbeads for immunoglobulin (IgG) recognition. The developed polymer microbead-based Raman/SERS immunoassay includes functional polystyrene (PS) microbeads, AuNPs, and SERS reporters, where the carboxylated PS microbeads serve as the immune-solid support, and the self-assembled monolayer (SAM) of 4-mercaptobenzoic acid (4-MBA) formed on the surface of 50 nm AuNPs is used as the SERS tags. Antibodies (donkey antigoat IgG) are bioconjugated to the PS microbeads, which are able to selectively recognize the 4-MBA/AuNP-conjugated antigens (goat antihuman IgG). The specific recognition of matched antibody and antigen can be confirmed by both fluorescence imaging and Raman/SERS analysis. By combining the Raman signals of polymer microbeads and SERS tags, the system could have promising application for simultaneous multiplex detection in homogeneous immunoassay systems

Pickering Emulsion as an Efficient Platform for Enzymatic Reactions without Stirring

To address the current limitations of enzymatic reactions, we develop a novel strategy to conduct stirring-free biphasic enzymatic reactions. This strategy involves translation of a conventional biphasic enzymatic reaction to a water-in-oil (W/O) Pickering emulsion system by adding a small amount of solid particle emulsifier. In such a system, enzymes, for example, a <i>Candida Antarctica</i> lipase B (CALB), are compartmentalized within millions of micron-sized water droplets, while organic substrates are dissolved in the oil phase (outside the droplets). It was demonstrated that CALB-catalyzed hydrolysis kinetic resolution of racemic esters in the stirring-free Pickering emulsion system gave favorable reaction efficiency and enantioselectivity as compared to those for the conventional biphasic system under stirring conditions, which was due to the large reaction interfacial area and the short molecule distances created by the Pickering emulsion droplets. The specific activity was found to depend on the water droplet size, highlighting the importance of the presence of droplets in the reaction system. Moreover, the convenient and effective recycling of CALB could be achieved through simple demulsification by centrifugation. After 27 reaction cycles, the ee values of ester and alcohol were still as high as 87.5% and 99%, respectively, which significantly exceed those of the conventional biphasic reaction. The high recyclability may be attributed to avoiding stirring that often causes damage to the three-dimensional structure of enzymes. This study compellingly demonstrates that a Pickering emulsion is an innovative platform to efficiently process enzymatic reactions without need for stirring and immobilization

Compartmentalization of Incompatible Reagents within Pickering Emulsion Droplets for One-Pot Cascade Reactions

It is a dream that future synthetic chemistry can mimic living systems to process multistep cascade reactions in a one-pot fashion. One of the key challenges is the mutual destruction of incompatible or opposing reagents, for example, acid and base, oxidants and reductants. A conceptually novel strategy is developed here to address this challenge. This strategy is based on a layered Pickering emulsion system, which is obtained through lamination of Pickering emulsions. In this working Pickering emulsion, the dispersed phase can separately compartmentalize the incompatible reagents to avoid their mutual destruction, while the continuous phase allows other reagent molecules to diffuse freely to access the compartmentalized reagents for chemical reactions. The compartmentalization effects and molecular transport ability of the Pickering emulsion were investigated. The deacetalization–reduction, deacetalization–Knoevenagel, deacetalization–Henry and diazotization–iodization cascade reactions demonstrate well the versatility and flexibility of our strategy in processing the one-pot cascade reactions involving mutually destructive reagents

image_1_High Indoleamine 2,3-Dioxygenase Is Correlated With Microvessel Density and Worse Prognosis in Breast Cancer.tif

<p>Indoleamine 2,3-dioxygenase (IDO), which catalyzes the breakdown of the essential amino acid tryptophan into kynurenine, is understood to have a key role in cancer immunotherapy. IDO has also received more attention because of its non-immune functions including regulating angiogenesis. The purpose of this study was to investigate the effects of IDO on microvessel density (MVD), and to explore its prognostic role in breast cancer. We showed IDO expression was positively correlated with MVD labeled by CD105 (MVD-CD105) rather than MVD labeled by CD31 (MVD-CD31) in breast cancer specimens. Both IDO expression and MVD-CD105 level were associated with initial TNM stage, histological grade, and tumor-draining lymph nodes (TDLNs) metastasis in breast cancer. In the prognostic analysis, TDLNs metastasis, an advanced TNM stage (III) and high histological grade (III) significantly predicted shorter survival in univariate analysis. Concentrating on IDO and MVD, the patients with IDO expression or high MVD level had poorer prognosis compared with no IDO expression [P = 0.047 for progress-free survival (PFS)] and low MVD level (P = 0.019 for OS); the patients with IDO expression and high MVD level had a tendency with shorter overall survival when compared with non IDO expression, low MVD level, or both (P = 0.062 for OS). In multivariate analysis, an advanced TNM stage (III) was significantly associated with shorter 5-year survival rate of PFS (HR: 0.126, 95% CI: 0.024–0.669, P = 0.015). In order to verify the phenomenon of IDO promoting angiogenesis, we contained the study in vitro. We detected the expression of IDO mRNA in breast cancer cell lines and measured the concentration of tryptophan and kynurenine in the supernatants of MCF-7 by high performance liquid chromatography. The ratio of Kyn and trp (kyn/trp) was calculated to estimate IDO-enzyme activity. MCF-7 cells, which produce high level of IDO and metabolize tryptophan, promoted human umbilical vein endothelial cells (HUVEC) proliferation significantly in co-culture system. Meanwhile IDO could upregulate the expression of CD105 in HUVEC, which was downregulated after adding IDO inhibitor, 1-methyl-d-trytophan. These results suggest that IDO could promote angiogenesis in breast cancer, providing a novel, potentially effective molecular or gene therapy target for angiogenesis inhibition in the future.</p

DataSheet_1_Identification of candidate genes regulating seed oil content by QTL mapping and transcriptome sequencing in Brassica napus.zip

Increasing oil production is a major goal in rapeseed (Brassica napus) molecular breeding programs. Identifying seed oil content (SOC)-related candidate genes is an important step towards achieving this goal. We performed quantitative trait locus (QTL) mapping of SOC in B. napus using a high-density SNP genetic map constructed from recombinant inbred lines and the Illumina InfiniumTM 60K SNP array. A total of 26 QTLs were detected in three years on A01, A03, A05, A06, A09, C01, C03 and C05, which accounted for 3.69%~18.47% of the phenotypic variation in SOC. Of these, 13 QTLs are reported here for the first time. 1713 candidate genes in the 26 QTLs confidence interval were obtained. We then identified differentially expressed genes (DEGs) between the high- and low-SOC accessions, to narrow down our focus to 21 candidate genes (Y1-Y21) related to SOC, and we will focus on 11 (Y1-Y11) candidate genes that contribute to the formation of high-SOC. In addition to providing insight into the genetic basis of SOC in B. napus, the loci identified and candidate genes in this study can be used in molecular breeding strategies to increase SOC in this important seed crop.</p

Genome-wide association scan for seed ADL content and the genomic landscape of the major locus on A05.

<p>(a) Association signals of ADL (2014) values on A05. The top of the panel shows an R-QTL region based on its significant SNPs, the positions of which are indicated by vertical green lines. Negative log10-transformed <i>p</i>-values from the compressed MLM are plotted on the vertical axis. The blue horizontal line indicates the 1% FDR-adjusted significance threshold (6.27 × 10⁻⁶); the bottom of the panel indicates the related candidate genes marked with green boxes in the R-QTL region. One previously identified gene, <i>PAL4</i>, was significantly associated with seed ADL content. (b) The distribution of the linkage disequilibrium (LD) blocks of the major locus on A05. (c) LD analysis of A05. (d) The LD decay of A05.</p

Overlapping or linkage relationships among seed ADL content quantitative trait loci (QTLs) in this and previous studies.

<p>Overlapping or linkage relationships among seed ADL content quantitative trait loci (QTLs) in this and previous studies.</p

Genome-wide association studies of seed ADL content (ADL) and seed hull content (HC).

<p>Manhattan plots of the compressed MLMs for ADL and HC. Negative log₁₀-transformed <i>p</i>-values from a genome-wide scan are plotted against position on each of the 19 chromosomes. The black horizontal dashed line indicates the genome-wide significance threshold, and the green marker is the simultaneously detected locus. (a): 13ADL, (c): 13HC, (e): 14ADL, (g): 14HC. Quantile-quantile plot of the compressed MLMs for ADL and HC, (b): 13ADL, (d): 13HC, (f): 14ADL. (h): 14HC.</p

Pseudohalogen-Based 2D Perovskite: A More Complex Thermal Degradation Mechanism Than 3D Perovskite

(MA)₂Pb­(SCN)₂I₂, a new pseudohalogen-based 2D perovskite material, was reported as a very stable and promising photo-absorber in PSCs previously. However, the later researchers found that MA₂Pb­(SCN)₂I₂ was not as stable as claimed. Thus, it is very critical to clarify the controversy and reveal the degradation mechanism of MA₂Pb­(SCN)₂I₂. On the other hand, a large number of studies have indicated that adding a small amount of SCN^– improves surface topography and crystallinity. However, whether SCN^– ions can be incorporated into a 3D perovskite film remains debatable. In this work, the thermal degradation pathway of (MA)₂Pb­(SCN)₂I₂ is revealed by thermal gravimetric and differential thermal analysis coupled with quadrupole mass spectrometry and density functional theory calculations. The decomposition of (MA)₂Pb­(SCN)₂I₂ has been proved experimentally to be more complex than that of MAPbI₃, involving four stages and multi-reactions from room temperature to above 500 °C. By combining the experimental results and theoretical calculations, it is found that 2D (MA)₂Pb­(SCN)₂I₂ actually is unstable when serving as photo-absorber in PSCs. Moreover, the role of SCN^– in improving the crystallinity of 3D perovskite has also been discussed in detail

Predictive ability of genome selection with different reference populations (x-axis) and SNP markers (y-axis).

<p>Predictive ability of genome selection with different reference populations (x-axis) and SNP markers (y-axis).</p