Mercury poses a significant threat to human health and the environment, and the United States Environmental Protection Agency has set a drinking water threshold of mercury (10 nM). Therefore, developing an environmentally friendly, on-site mercury ion (Hg2+) detection is highly desirable. Based on the synergetic catalysis of gold nanoparticles (AuNPs) and mercury, a simple and ultrasensitive colorimetric method for the determination of Hg2+ was established. The innovation of this work is to propose a strategy based on the self-assembly of two-dimensional (2D) AuNPs for colorimetric detection of Hg2+. The AuNPs are self-assembled into a densely arranged 2D AuNP layer at the liquid/liquid interface between dimethyl carbonate and water, which converts from the disordered distribution of AuNPs in 3D space to an orderly 2D AuNP layer distribution. This avoids the shortcomings of poor repeatability and weak detection signals caused by the uneven sampling before and greatly plays the catalytic role of each AuNP. In this work, gold amalgam catalyzes colorless 3,3′,5,5′-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) to yield blue-green oxidized TMB (oxTMB), realizing the colorimetric quantitative detection of Hg2+ in water systems. In this process, the formation of gold amalgam greatly improves the catalytic ability of AuNPs, and the detection limit of mercury ions is as low as 0.021 nM. The practical application of this sensor in the determination of Hg2+ in tap water samples has also been successfully verified, providing an effective method for environmental monitoring.
We report a dual-channel array based on gold nanorods (GNRs) to catalyze the reaction of methyl orange (MO) and sodium borohydride (NaBH4) for recognition of multiple amino acids. The sensor array consists of two channels: ultraviolet absorption and surface potential measurements. When amino acids with negative charges exist, positively charged GNRs and negatively charged amino acids attract each other, triggering the catalytic reduction ability of the GNRs to weaken and resulting in a decrease in the amount of reduction products of MO. Therefore, compared with the solution without target amino acids with negative charges, the absorbance of the solution at 460 nm decreases and zeta potential of the solution increases. However, in the presence of positively charged amino acids, the result is opposite to that of negatively charged amino acids mentioned above. Due to different amino acids with different charges, their existence leads to specific array's response patterns, i.e., ultraviolet absorption and surface potentials, which are distinguished by linear discriminant analysis. The sensor array successfully distinguished five amino acids (glutamic acid (Glu), lysine (Lys), aspartic acid (Asp), arginine (Arg), and histidine (His)) at the 100 nM level in complex media, showing great potential in the field of clinical diagnosis, biomedical research, and so on.
Objective To study the neuroprotective effect of apigenin on microglia which was exposed to oxygen glucose deprivation and reperfusion (OGD/R), which was characterized by its influence on IL-1β and TNF-α expression. Methods Primary microglial cultures were prepared from newborn rat brain. The purity of isolated cells were identified by GSA-IB4. The cells were randomized into 5 groups:normal group, DMSO group and apigenin-treated groups (10, 25, 50 μmol/L). The cells of DMSO group and apigenin-treated group were exposed to 8 h of OGD and 24 h of reperfusion in the presence or absence of apigenin at a range of concentrations. Culture supernatants were collected and IL-1β and TNF-α were detected by ELISA assay. Results The expression of IL-1β and TNF-α were significantly higher in DMSO group (P0.01), however, apigenin concentration-dependently suppressed IL-1β and TNF-α production of microglial. Conclusion Apigenin may play a neuroprotective effect which was related with depression of IL-1β and TNF-α production in OGD/R microglia.
To provide decision support to the commander, it is necessary to calculate shipborne vehicles’ sortie mission reliability during the formulation of the layout plan. Therefore, this paper presents the sortie mission network model and reliability calculation method for shipborne vehicles. Firstly, the shipborne vehicle layout and sortie task characteristics are used to establish the sortie mission network model. The shipborne vehicles' sortie mission reliability problem is transformed into a two-terminal network reliability problem. Secondly, the minimal path set method is used to calculate the two-terminal network reliability. An improved tabu search algorithm based on a strategy of breaking up the whole into parts is proposed to search for the minimal path set that matches the length. Finally, the sum of disjoint products is used to process the minimal path set to obtain the shipborne vehicles’ sortie mission reliability calculation formula. A numerical analysis of two simplified shipborne vehicles’ layouts is given to illustrate the calculation process of the method. This study provides a new evaluation index and an effective quantitative basis for the evaluation system of shipborne vehicles’ layout. It also provides theoretical support for the development of decision-making related to the sortie mission of shipborne vehicles.
Abstract In close-range photogrammetry, some improved designs have been developed to increase the coding capacity of Schneider-like concentric circular coded targets. However, another typical type, Hattori-like dot-dispersing coded targets (HCTs), is rarely expanded. In this paper, we give our detailed solution to recognize a kind of non-public HCT used in video-simultaneous triangulation and resection systems. Then, an advanced HCT (AHCT) with multiple templates and simplified P2 -Invariant is proposed, which achieves capacity expansion and recognition acceleration. First, the cross-ratio invariant is used in template recognition, and then the affine transformation is used in decoding. During the template recognition process, multiple templates are designed to expand the coding capacity, and a simplified P2 -Invariant is adopted to accelerate the recognition. Experiments are carried out with different shooting angles ranging from 0° to 80°, with smaller coded targets, with mixed coded targets of different sizes and with large outdoor scenes, and the results show that AHCTs can not only preserve the stability of the HCTs, but also achieve the capacity growth of coded targets at a faster recognition rate by 14.6%. The AHCTs with large capacity can be applied in scenarios with a large size or complex structure, and the acceleration advantage can be considered in real-time dynamic domains.
In recent years,the research on cotton genomics was greatly developed due to accumulation of a great deal of bioinformatics data from different cotton species,which put a solid foundation for cotton breeding by design.In this paper,we reviewed the progresses and present status of cotton molecular breeding in recent years.Some strategies to cotton molecular breeding in the future was put forward.
Abstract Recently, single‐atom catalysts are attracting much attention in sensor field due to their remarkable peroxidase‐ or oxidase‐like activities. Herein, peroxidase‐like FeCoZn triple‐atom catalyst supported on S‐ and N ‐doped carbon derived from ZIF‐8 (FeCoZn‐TAC/SNC) serves as a proof‐of‐concept nanozyme. In this paper, a dual‐channel nanozyme‐based colorimetric sensor array is presented for identifying seven preservatives in food. Further experiments reveal that the peroxidase‐like activity of the FeCoZn TAzyme enables it to catalyze the oxidation of 3,3′,5,5′‐tetramethylbenzidine (TMB) and o‐phenylenediamine (OPD) in the presence of H 2 O 2 , yielding the blue oxTMB and yellow oxOPD, respectively. However, food preservatives are adsorbed on the nanozyme surface through π–π stacking interaction and hydrogen bond, and the reduction in catalytic activity of FeCoZn TAzyme causes differential colorimetric signal variations, which provide unique “fingerprints” for each food preservative.
Colorectal cancer (CRC) is a common human malignancy. The aims of this study are to investigate the gene expression profile of CRC and to explore potential strategy for CRC diagnosis, therapy and prognosis. We use affy and Limma package of Bioconductor R to do differential expression genes (DEGs) and differential expression lncRNAs (DELs) analysis from the gene datasets (GSE8671, GSE21510, GSE32323, GSE39582 and TCGA) respectively. Then, DEGs were analyzed by GO and KEGG pathway and Kaplan-Meier survival curve and Cox regression analyses were used to find aberrantly expressed genes associated with survival outcome of CRC patients. Real-time PCR assay was used to verify the aberrantly expressed genes expression in CRC samples. 306 up-regulation and 213 down-regulation common DEGs were found. A total of 485 DELs were identified, of which 241 up-regulated and 244 down-regulated. Then, GO and KEGG pathway analyses showed that DEGs were involved in cell cycle, mineral absorption, DNA replication, and Nitrogen metabolism. Among them, Kaplan-Meier survival curve and Cox regression analyses revealed that CDC6, CDC45, ORC6 and SNHG7 levels were significantly associated with survival outcome of CRC patients. Finally, real-time PCR assay was used to verify that the CDC6, CDC45, ORC6 and SNHG7 expression were up-regulated in 198 CRC samples compared with the expression levels in individual-matched adjacent mucosa samples. CDC6, CDC45, ORC6 and SNHG7 are implicated in CRC initiation and progression and could be explored as potential diagnosis, therapy and prognosis targets for CRC.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)