NIR-II Fluorescence Sensor Based on Steric Hindrance Regulated Molecular Packing for In Vivo Epilepsy Visualization.

Fluorescence sensing is crucial to studying biological processes and diagnosing diseases, especially in the second near-infrared (NIR-II) window with reduced background signals. However, it's still a great challenge to construct "off-on" sensors when the sensing wavelength extends into the NIR-II region to obtain higher imaging contrast, mainly due to the difficult synthesis of spectral overlapped quencher. Here, we present a new fluorescence quenching strategy, which utilizes steric hindrance quencher (SHQ) to tune the molecular packing state of fluorophores and suppress the emission signal. Density functional theory (DFT) calculations further reveal that large SHQs can competitively pack with fluorophores and prevent their self-aggregation. Based on this quenching mechanism, a novel activatable "off-on" sensing method is achieved via bio-analyte responsive invalidation of SHQ, namely the Steric Hindrance Invalidation geNerated Emission (SHINE) strategy. As a proof of concept, the ClO--sensitive SHQ lead to the bright NIR-II signal release in epileptic mouse hippocampus under the skull and high photon scattering brain tissue, providing the real-time visualization of ClO- generation process in living epileptic mice.

A cell hybridization-based method of generating recombinant rabbit monoclonal antibodies for detecting cytokines.

Recombinant rabbit monoclonal antibodies (rabbit rAbs) have shown promise in various biomedical fields. However, it is challenging and costly to generate rabbit rAbs using traditional techniques. Here we describe a convenient and cost-effective method. Using this method, we generated rabbit rAbs against mouse soluble IL-6 receptor α with affinities in the range of 10-9 to 10-12 M. The presented method is suitable for industrial and academic scientists looking to customize rabbit rAbs for their research.

Activatable NIR-II Photothermal Lipid Nanoparticles for Improved Messenger RNA Delivery.

Endosomal escape remains a central issue limiting the high protein expression of mRNA therapeutics. Here, we present second near-infrared (NIR-II) lipid nanoparticles (LNPs) containing pH activatable NIR-II dye conjugated lipid (Cy-lipid) for potentiating mRNA delivery efficiency via a stimulus-responsive photothermal-promoted endosomal escape delivery (SPEED) strategy. In acidic endosomal microenvironment, Cy-lipid is protonated and turns on NIR-II absorption for light-to-heat transduction mediated by 1064 nm laser irradiation. Then, the heat-promoted LNPs morphology change triggers rapid escape of NIR-II LNPs from the endosome, allowing about 3-fold enhancement of enhanced green fluorescent protein (eGFP) encoding mRNA translation capacity compared to the NIR-II light free group. In addition, the bioluminescence intensity induced by delivered luciferase encoding mRNA in the mouse liver region shows positive correlation with incremental radiation dose, indicating the validity of the SPEED strategy.

A Novel Near-Infrared Ratiometric Fluorescence Probe for Hg2+ Based on Quinoline-Fused Rhodamine Dye.

As one of the most toxic metals, Mercury ions cause serious environmental pollution and threaten the health of living organisms. Hence, we designed and synthesised a new near-infrared (NIR) ratiometric fluorescent probe toward monitoring of Hg2+ based on quinoline-fused rhodamine dye. Owing to the specific spirolactam ring-opening reaction, the probe exhibits a ratiometric fluorescent change after treatment of Hg2+ with increased emission in NIR and significantly reduced emission in visible region. The specific response mechanism and dual-channel fluorescence change allow the probe to have remarkable detection selectivity, fast response and high detection sensitivity. Moreover, with the properties of excellent cell permeability and low cytotoxicity, probe can be applied as detection tool for mercury ions with dual-channel ratiometric fluorescence imaging in living cell.

The copper-catalyzed synthesis of (Z)-2H-naphtho[1,8-bc]thiophenes with solid emission.

In recent years, one of the main research interests of our group has been the construction of 6/5 π-systems through the regioselective conversion of parallel alkynes in naphthalene with the aim of exploiting potential fluorescent materials. Herein, the copper-catalyzed synthesis of polysubstituted (Z)-2H-naphtho[1,8-bc]thiophenes from 8-halo-1-ethynylnaphthalenes using potassium ethylxanthate as the sulfur source is reported. In this protocol, a series of thiophene-fused 6/5 π-system compounds was synthesized via copper-catalyzed Ullmann-type C(aryl)-S bond formation and the α-addition of an alkyne bond with high selectivity and in high yields. The synthesized polysubstituted (Z)-2H-naphtho[1,8-bc]thiophenes exhibited solid emission, which made them potential candidates for use in optoelectronic conjugated materials. By using DMSO/D2O (3 : 1) as the reaction solvent, the deuterated products could be obtained in good yields under standard conditions.

Autistic traits and internet gaming addiction in Chinese children: The mediating effect of emotion regulation and school connectedness.

This report details an 18-month longitudinal study designed to investigate the influence of autistic traits' on internet gaming addiction (IGA) in children. A total of 420 Chinese children (220 boys, Mean age=9.74±0.45) participated in the research. Autistic traits were measured in the 4th grade and emotion regulation, school connectedness and IGA measured in both the 4th and 5th grades. After controlling for age, sex, and sensation seeking, results showed that autistic traits were related to decreased emotion regulation, which in turn was related to lower school connectedness, which was related to increased IGA. The results suggest that improving emotion regulation and school connectedness could reduce the risk of IGA. As a result, these findings may inform intervention and prevention programs targeting children with IGA, especially among those with high levels of autistic traits.

[Ion-exchange chromatographic behavior and characterization of Staphylococcus aureus in exponential phase].

A rapid, simple and sensitive method was developed to characterize S. aureus in exponential phase by a high performance ion-exchange chromatograph equipped with a laser light-scattering detector. An ion-exchange column (TSKgel SuperQ-TOYOPEARL 650C column, 7.6 mm i.d. x 100 mm, Tosoh, Japan) was used for the separation. The mobile phase was a 20 mmol/L piperazine-hydrochloric acid (pH 6.0) buffer. It was found that S. aureus in exponential phase exhibited two elution peaks. Transmission electron microscope (TEM) showed that the bacterial cells in the first peak appeared to be circular, while the cells in the second one appeared to be elliptical and had one obvious diaphragm. It is found that the proliferation capability of the second fraction was better than the first fraction by 65.3%. These results suggested that the first fraction was the S. aureus that stopped dividing, while the second one was the S. aureus that were undergoing cell division. Therefore, the chromatographic method developed here may be a promising tool for the rapid and efficient separation and characterization of bacterial cells.