High-Throughput Functional Screening of Antigen-Specific T Cells Based on Droplet Microfluidics at a Single-Cell Level.

The lack of an efficient method for the identification of tumor antigen-specific T cell receptors (TCRs) impedes the development of T cell-based cancer immunotherapies. Here, we introduce a droplet-based microfluidic platform for function-based screening and sorting of tumor antigen-specific T cells with high throughput. We built a reporter cell line by co-transducing the TCR library and reporter genes at the downstream of TCR signaling, and reporter cells fluoresced upon functionally binding with antigens. We co-encapsulated reporter cells and antigen-presenting cells in droplets to allow for stimulation on a single-cell level. Functioning reporter cells specific against the antigen were identified in the microfluidic channel based on the fluorescent signals of the droplets, which were immediately sorted out using dielectrophoresis. We validated the reporter system and sorting results using flow cytometry. We then performed single-cell RNA sequencing on the sorted cells to further validate this platform and demonstrate the compatibility with genetic characterizations. Our platform provides a means for precise and efficient T cell immunotherapy, and the droplet-based high-throughput TCR screening method could potentially facilitate immunotherapeutic screening and promote T cell-based anti-tumor therapies.

A Fluorescence Resonance Energy Transfer Probe Based on DNA-Modified Upconversion and Gold Nanoparticles for Detection of Lead Ions.

We report a new sensor for the specific detection of lead ions (Pb2+) in contaminated water based on fluorescence resonance energy transfer (FRET) between upconversion nanoparticles (UCNPs) as donors and gold nanoparticles (Au NPs) as receptors. The UCNPs modified with Pb2+ aptamers could bind to Au NPs, which were functionalized with complementary DNA through hybridization. The green fluorescence of UCNPs was quenched to a maximum rate of 80% due to the close proximity between the energy donor and the acceptor. In the presence of Pb2+, the FRET process was broken because Pb2+ induced the formation of G-quadruplexes from aptamers, resulting in unwound DNA duplexes and separated acceptors from donors. The fluorescence of UCNPs was restored, and the relative intensity had a significant linear correlation with Pb2+ concentration from 0 to 50 nM. The sensor had a detection limit as low as 4.1 nM in a buffer solution. More importantly, the sensor exhibited specific detection of Pb2+ in complex metal ions, demonstrating high selectivity in practical application. The developed FRET prober may open up a new insight into the specific detection of environmental pollution.

Exposed metal oxide active sites on mesoporous titania channels: a promising design for low-temperature selective catalytic reduction of NO with NH3.

A subtle catalyst design is provided with stably incorporated binary catalytically active centers of CuO and MnO2 on the surface wall of mesoporous TiO2. Such unique features render these mesoporous composites highly promising in the low-temperature selective catalytic reduction of NO with NH3, including high NO conversion efficiency, and superior H2O and SO2 resistance.

Phenyl-functionalized mesoporous silica materials for the rapid and efficient removal of phthalate esters.

Phthalate esters (PAEs) are a group of endocrine disrupting compounds, which have been widely used as plasticizers. To alleviate the environmental and health threats from water resources polluted by PAEs, we prepared phenyl functionalized mesoporous silica materials (ph-SBA-15) were synthesized by a simple post-modification approach for rapid and efficient removal of low concentration of di-n-butyl phthalate (DBP) from aqueous solution. Mesostructure, texture, surface chemistry and surface charges were systemically characterized. The obtained ph-SBA-15 possesses a highly ordered mesostructure, a high surface area (418m2/g), uniform mesopores (6.5nm) and high-density organic groups around 11wt.%. Batch adsorption experiments revealed that phenyl modified SBA-15 had an excellent ability to remove DBP with the maximum adsorption capacity up to ∼40mg/g at 25°C. The thermodynamics and kinetics for the adsorption were also investigated, demonstrating an exothermic, multi-layer and fast adsorption process. In addition, DBP adsorption was found to be sensitive to the pH and the uptake was observed to be greatest at around pH 7.0. Furthermore, this material can be effectively regenerated by ethanol.

Research progress on identification of QTLs and functional genes involved in salt tolerance in soybean.

The yield of soybean is substantially reduced when the crop is grown in salinity-affected soil. This review summarizes the progress achieved in defining the genetic basis of salinity tolerance. Both forward (uncovering the genetic basis of a phenotype by exploiting natural or induced mutations) and reverse (defining the phenotype which arises as a result of an altered DNA sequence) genetics methods have been used to reveal the function of key salinity response genes. Quantitative trait locus analysis has identified six regions of the genome which harbor loci influencing salinity tolerance, and positional cloning has succeeded in isolating one important salt tolerant gene. Meanwhile the application of the genome-wide association study technique has led to the isolation of a second gene involved in salinity tolerance. Reverse genetics experiments have highlighted a number of salinity response genes, mainly including ion transporter genes and transcription factor genes. These studies lay the foundations for understanding the mechanistic basis of salinity tolerance in soybean, knowledge of which would be essential to enable the breeding of highly salinity tolerant soybean cultivars through the use of marker-assisted selection or transgenesis.