A Long Wave-Infrared Miniatured Quantum Dot Spectrometer.

In this work, a long-wave infrared (LWIR) quantum dot (QD) spectrometer was constructed for the first time by integrating a 255-element HgSe QD filter array with an LWIR array detector. The filter array was fabricated using a combination inkjet printing strategy with eight types of T-dodecyl mercaptan-terminated HgSe QD inks. The stability and morphology of the QDs were improved by optimizing the purification methodology and ligand modification. Combined with the compressive-sensing-based least-squares linear regression (CS-LS) algorithm, the LWIR QD spectrometer achieved a spectral resolution of 5.4 cm-1 over a wide spectral range of 8 to 14 µm, enabling the detection of the chemical warfare agent simulant dimethyl methylphosphonate. This technology is expected to facilitate the development of smaller volumes and more accurate identification of various targets in the future. This paper offers an approach to fabricating low-cost LWIR spectrometers and promoting the scale-up applications of QD devices.

Model-Based Practically Precise Fabrication of HgSe Quantum Dots toward Their Application in a Long-Wave Infrared Micro Spectrometer.

Quantum dot (QD) passive filters present a simple and low-cost strategy for the micromation of spectrometers. In this field, the consistency between ultranarrow band gap QD fabrication and the precise control of its absorption characteristics is the key-challenge to extend QD spectrometers into the long-wave infrared (LWIR) region. Here, we show the model-based, practically precise fabrication of HgSe QDs as well as their specific spectral responses. Both the theoretical and experimental models of the HgSe QDs r-λ are formulated, which reveals the variation of transmission spectrum with the size of HgSe QDs. Then, the HgSe QDs synthesis parameter-spectral response hyperplane model and neural network model were obtained by using traditional polynomial fitting and machine learning, respectively. We also demonstrate the model-based precise fabrication of HgSe QDs with transmission characteristic peaks within 14 µm. The further simulation also shows that the 255─element QD filter array has the signal-to-noise ratio up to 14.57 dB with detection resolution about 5 cm-1.

Synthesis and Application of Polymer SXFA in the Detection of Organophosphine Agents with a SAW Sensor.

The effective detection of isopropyl methylfluorophosphonate (GB, sarin), a type of organophosphine poisoning agent, is an urgent issue to address to maintain public safety. In this research, a gas-sensitive film material, poly (4-hydroxy-4,4-bis trifluoromethyl)-butyl-1-enyl)-siloxane (SXFA), with a structure of hexafluoroisopropyl (HFIP) functional group was synthesized by using methyl vinylpropyl dichlorosilane and hexafluoroacetone trihydrate as initial materials. The synthesis process products were characterized using FTIR. SXFA was prepared on a 200 MHz shear surface wave delay line using the spin-coating method for GB detection. A detection limit of <0.1 mg/m3 was achieved through conditional experiments. Meanwhile, we also obtained a maximum response of 2.168 mV at a 0.1 mg/m3 concentration, indicating the much lower detection limit of the SAW-SXFA sensor. Additionally, a maximum response standard deviation of 0.11 mV with a coefficient of variation of 0.01 and a maximum recovery standard deviation of 0.22 mV with a coefficient of variation of 0.02 were also obtained through five repeated experiments. The results show that the SAW-SXFA sensor has strong selectivity and reproducibility, good selectivity, positive detection ability, high sensitivity, and fast alarm performance for sarin detection.

Loss of RNA-binding protein CELF2 promotes acute leukemia development via FAT10-mTORC1.

RNA-binding proteins (RBPs) are critical regulators for RNA transcription and translation. As a key member of RBPs, ELAV-like family protein 2 (CELF2) has been shown to regulate RNA splicing and embryonic hematopoietic development and was frequently seen dysregulated in acute myeloid leukemia (AML). However, the functional role(s) of CELF2 in hematopoiesis and leukemogenesis has not been fully elucidated. In the current study, we showed that Celf2 deficiency in hematopoietic system led to enhanced HSCs self-renewal and differentiation toward myeloid cells in mice. Loss of Celf2 accelerated myeloid cell transformation and AML development in MLL-AF9-induced AML murine models. Gene expression profiling integrated with RNA immunoprecipitation sequencing (RIP-Seq), together with biochemical experiments revealed that CELF2 deficiency stabilizes FAT10 mRNA, promotes FAT10 translation, thereby increases AKT phosphorylation and mTORC1 signaling pathway activation. Notably, combination therapy with a mTORC1 inhibitor (Rapamycin) and a MA9/DOTL1 inhibitor (EPZ-5676) reduced the leukemia burden in MLL-AF9 mice lacking Celf2 in vivo. Our study elucidated a novel mechanism by which the CELF2/FAT10-AKT/mTORC1 axis regulates the proliferation of normal blood cells and the development of AML, thus providing potential therapeutic targets for myeloid leukemia suppression.

A passive wireless surface acoustic wave (SAW) sensor system for detecting warfare agents based on fluoroalcohol polysiloxane film.

Long-term monitoring of environmental warfare agengts is a challenge for chemical gas sensors. To address this issue, we developed a 433 MHz passive wireless surface acoustic wave (WSAW) gas sensor for dimethyl methylphosphonate (DMMP) detection. This WSAW gas sensor includes a YZ lithium niobate (LiNbO3) substrate with metallic interdigital transducers (IDTs) etched on it, and an antenna was placed near the IDT. A DMMP-sensitive viscoelastic polymer fluoroalcoholpolysiloxane (SXFA) film was prepared on a LiNbO3 substrate, and mode modeling coupling was used to optimize the design parameters. The sensor can function properly in an environments between -30 °C and 100 °C with humidity less than 60% RH. When the wireless transmission distance was within the range of 0-90 cm, the sensor noise increased with distance, and the stability was less than 32°/h. While optimizing the film thickness of SXFA, a relationship was observed between sensor sensitivity and film thickness. When the film thickness of SXFA reached 450 nm, the optimal value was reached. At a distance of 20 cm between the transmitting and receiving antennas, DMMP was detected at different concentrations with the developed WSAW gas sensor. The lower detection limit of DMMP was 0.48 mg/m3, the sensitivity of the sensor was 4.63°/(mg/m3), and repeatable performance of the sensor was confirmed.