Search

Understanding the pathological process of biological systems can greatly improve the prevention and treatment of diseases. The study of pathological processes has now reached the molecular level, and molecular fluorescent probes have become a powerful tool. Chromene, also known as benzo-pyran molecule, is a structural element of natural products with good biological compatibility and was developed as a fluorescent probe. The thiol-chromene "click" nucleophilic pyran ring-opening reaction allows the quick detection of thiol. In this work, the chromene alcohol can function as an efficient self-immolative spacer, which covalently links NIR fluorophore via a carbonyl ester. Due to its favorable characteristics and superior applicability, the self-immolative amplifier

Spiroplasma eriocheiris (S. eriocheiris) infection has caused heavy economic losses in Macrobrachium nipponense (M. nipponense) aquaculture industry. However, the interplay between immune responses of M. nipponense and S. eriocheiris infection has not yet been fully elucidated. Herein, full-length transcriptome profiling of M. nipponense hemocytes was performed with or without S. eriocheiris challenge. In total, 20,441 high quality unigenes were obtained, among which 733 differentially expressed genes (DEGs) were found, including 309 up-regulated and 424 down-regulated genes. Protein-protein interaction network (PPI) analysis of DEGs identified 4 hub immune-related genes, including MAP kinase-interacting serine/threonine-protein kinase 1 (MNK1), C-type lectin 4 (CTL4), gamma-interferon-inducible lysosomal thiol reductase (GILT), and anti-lipopolysaccharide factor (ALF). Tissue distribution and expression analysis of the key immune-associated genes demonstrated that they were widely expressed in 6 tissues, especially in gills, and were up-regulated by S. eriocheiris challenge. M. nipponense challenged by S. eriocheiris exhibited a significant reduction of bacterial clearance ability when the hub genes were silenced via RNA interference. Overall, our results indicated that the 4 hub immune-related genes play a vital role in anti-S. eriocheiris infection, thus providing insights into the immune defensive response mechanisms of M. nipponense against S. eriocheiris infection.

With the improvement of organic synthesis technology and the development of fluorescent probe, more and more fluorescent probes with excellent performance and versatility are required, so as to better realize their application value. High sensitivity, high selectivity, targetable and fast response NIR fluorescence probes are still needed for hydrogen sulfide precise detection. In this study, phenol containing 2, 4-dinitro group was selected as a strong electrophilic group to promote the nucleophilic substitution reaction. After the nucleophilic addition reaction between probe and hydrogen sulfide with delicate structure, strong nucleophile, 2, 4-dinitrophenol departure quickly and the NIR fluorophore was released, which showed fluorescence emission at 741 nm, and the probe detection limit for hydrogen sulfide was calculated as 96 nM. Interestingly, because of the positive charge in the hemiocyanine, the probe can locate efficiently in the mitochondria. This fluorescent probe with excellent performance was used to detect the endogenous levels of hydrogen sulfide in vivo. This work provides guidance for the design of multifunctional and high-performance fluorescent probes.

As an important biological messenger and effector molecule, hydrogen sulfide (H2S) not only is involved in maintaining the physiological function in cardiovascular, immune and nervous systems but also controls the activity of mitochondrial atpase and antioxidant stress in living cells. Herein, a new PET-based mitochondria-targeted NIR probe Mito-N3 with good selectivity and high sensitivity for H2S was presented in this work. The free probe has no fluorescence, however, once reacts with H2S, Mito-N3 goes through an analyte-prompted immolation, resulting in the releasing of the fluorophore (Mito−OH) and the concomitant restoring of remarkable fluorescence in the NIR emission at 736 nm. The detection limit was calculated as low as 20 nM. Most importantly, fluorescence imaging experiments showed that the probe can monitor the intracellular H2S level in mitochondria of MCF-7 cells, the probe Mito-N3 also had the potential application in sensing and tracking H2S in living nude mice.

A new near-infrared (NIR) fluorescent probe based on 2-Methylchromone was exploited for relay recognition of Cu2+ and biothiols. The mechanism involved in complex between metal ion and probe, and subsequent displacement reaction, which make the probe can detect GSH by NIR fluorescence turn on emission. Probe showed a fluorescence band at 718 nm in PBS-EtOH (3:2, v/v, 10 mM PBS, pH 7.4) solution. Upon the addition of Cu2+, a large fluorescence quenching was observed due to the coordination between probe 1 and Cu2+. The 1-Cu2+ could be used to detect biothiols utilizing high affinity of biothiols with Cu2+. This “on-off-on” fluorescent probe was also successfully applied to image GSH in MCF-7 cells and zebrafish.

(PhSe) 2 Pb has been prepared and decomposed in vacuum at 500 °C. From the analysis of the volatile decomposition products obtained by gas chromatography/mass spectrometry (GC/MS), it is shown that the major decomposition pathway is phenyl migration, and homolysis is a minor pathway. It is also confirmed that no hydrocarbon, except biphenyl, is formed via pyrolysis of (PhSe) 2 Pb. This result reveals that (PhSe) 2 Pb may be a useful single-source for the growth of PbSe thin films with low carbon contamination.