Lattice Plainification Leads to High Thermoelectric Performance of P-Type PbSe Crystals.

Thermoelectrics has applications in power generation and refrigeration. Since only commercial Bi2Te3 has a low abundance Te, PbSe gets attention. This work enhances the near-room temperature performance of p-type PbSe through enhancing carrier mobility via lattice plainification. Composition controlled and Cu-doped p-type PbSe crystals are grown through physical vapor deposition. Results exhibit an enhanced carrier mobility ≈2578 cm2 V-1 s-1 for Pb0.996Cu0.0004Se. Microstructure characterization and density functional theory calculations verify the introduced Cu atoms filled Pb vacancies, realizing lattice plainification and enhancing the carrier mobility. The Pb0.996Cu0.0004Se sample achieves a power factor ≈42 µW cm-1 K-2 and a ZT ≈ 0.7 at 300 K. The average ZT of it reaches ≈0.9 (300-573 K), resulting in a single-leg power generation efficiency of 7.1% at temperature difference of 270 K, comparable to that of p-type commercial Bi2Te3. A 7-pairs device paired the p-type Pb0.996Cu0.0004Se with the n-type commercial Bi2Te3 shows a maximum cooling temperature difference ≈42 K with the hot side at 300 K, ≈65% of that of the commercial Bi2Te3 device. This work highlights the potential of p-type PbSe for power generation and refrigeration near room temperature and hope to inspire researchers on replacing commercial Bi2Te3.

Grid-plainification enables medium-temperature PbSe thermoelectrics to cool better than Bi2Te3.

Thermoelectric cooling technology has important applications for processes such as precise temperature control in intelligent electronics. The bismuth telluride (Bi2Te3)-based coolers currently in use are limited by the scarcity of Te and less-than-ideal cooling capability. We demonstrate how removing lattice vacancies through a grid-design strategy switched PbSe from being useful as a medium-temperature power generator to a thermoelectric cooler. At room temperature, the seven-pair device based on n-type PbSe and p-type SnSe produced a maximum cooling temperature difference of ~73 kelvin, with a single-leg power generation efficiency approaching 11.2%. We attribute our results to a power factor of >52 microwatts per centimeter per square kelvin, which was achieved by boosting carrier mobility. Our demonstration suggests a path for commercial applications of thermoelectric cooling based on Earth-abundant Te-free selenide-based compounds.

Efficacy and safety of CM310 in severe eosinophilic chronic rhinosinusitis with nasal polyps (CROWNS-1): a multicentre, randomised, double-blind, placebo-controlled phase 2 clinical trial.

Background: Severe eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) remains the most relapsed subtype of uncontrolled CRSwNP. CM310, a humanised anti-interleukin (IL)-4 receptor alpha monoclonal antibody, inhibits IL-4 and IL-13 signaling which underlying eosinophilic inflammation. This study aims to evaluate the efficacy and safety of CM310 in patients with severe ECRSwNP. Methods: A multicentre, randomised, double-blind, and placebo-controlled phase 2 clinical trial was conducted. 56 eligible adult patients with severe ECRSwNP were randomised 1:1 to receive subcutaneously either CM310 (300 mg) or placebo every 2 weeks under the background therapy of mometasone furoate nasal spray (MFNS) for 16 weeks, with 8 weeks of follow-up. Coprimary endpoints included the changes from baseline in nasal polyp score (NPS) and nasal congestion score (NCS) at week 16. Key secondary endpoints included sinus Lund-Mackay CT score, change in sinus volume occupied by disease, University of Pennsylvania Smell Identification Test score, 22-item Sino-nasal Outcome Test score, and total symptom score. Safety, pharmacodynamics, and changes in type 2 inflammation biomarkers were assessed. This study is registered with ClinicalTrials.gov, NCT04805398. Findings: Between April 6, 2021, and March 18, 2022, 27 patients respectively in both the CM310 and placebo groups completed the study. Findings suggested that CM310 improved the coprimary efficacy endpoints of decreasing nasal polyp size and alleviating nasal congestion compared with the placebo. Least squares (LS) mean differences (CM310 vs placebo) of change from baseline in NPS and NCS at week 16 were -2.1 (95% CI -2.9, -1.4; p < 0.0001) and -0.9 (95% CI -1.4, -0.5; p < 0.0001), respectively. Sinus CT scan revealed that Lund-Mackay CT score (LS mean difference [95% CI] -7.6, [-9.4, -5.8]; p < 0.0001) and sinus volume occupied by disease (LS mean difference [95% CI] -37%, [-47%, -28%]; p < 0.0001) were significantly improved with CM310 compared with placebo. In addition, CM310 significantly relieved the daily symptoms of patients with CRSwNP and improved their quality of life reflected by the improvements in the TSS (-2.6 [95% CI -3.5, -1.6]), UPSIT (10.4 [95% CI 6.8, 14.0]) and SNOT-22 score (-19.1 [95% CI -29.8, -8.5]). Compared with placebo, CM310 administration significantly reduced type 2-related biomarkers including the serum TARC and total IgE, and tissue eosinophils. The most common adverse events were upper respiratory tract infection, blood cholesterol increased, and tinnitus, but none were considered drug-related. Interpretation: These findings support CM310 as an effective additional treatment option to the standard of care in patients with severe ECRSwNP. Funding: KeyMed Biosciences (Chengdu) Limited.

Lattice plainification advances highly effective SnSe crystalline thermoelectrics.

Thermoelectric technology has been widely used for key areas, including waste-heat recovery and solid-state cooling. We discovered tin selenide (SnSe) crystals with potential power generation and Peltier cooling performance. The extensive off-stoichiometric defects have a larger impact on the transport properties of SnSe, which motivated us to develop a lattice plainification strategy for defects engineering. We demonstrated that Cu can fill Sn vacancies to weaken defects scattering and boost carrier mobility, facilitating a power factor exceeding ~100 microwatts per centimeter per square kelvin and a dimensionless figure of merit (ZT) of ~1.5 at 300 kelvin, with an average ZT of ~2.2 at 300 to 773 kelvin. We further realized a single-leg efficiency of ~12.2% under a temperature difference (ΔT) of ~300 kelvin and a seven-pair Peltier cooling ΔTmax of ~61.2 kelvin at ambient temperature. Our observations are important for practical applications of SnSe crystals in power generation as well as electronic cooling.

Realizing high-ranged thermoelectric performance in PbSnS2 crystals.

Great progress has been achieved in p-type SnS thermoelectric compound recently, while the stagnation of the n-type counterpart hinders the construction of thermoelectric devices. Herein, n-type sulfide PbSnS2 with isostructural to SnS is obtained through Pb alloying and achieves a maximum ZT of ~1.2 and an average ZT of ~0.75 within 300-773 K, which originates from enhanced power factor and intrinsically ultralow thermal conductivity. Combining the optimized carrier concentration by Cl doping and enlarged Seebeck coefficient through activating multiple conduction bands evolutions with temperature, favorable power factors are maintained. Besides, the electron doping stabilizes the phase of PbSnS2 and the complex-crystal-structure induced strong anharmonicity results in ultralow lattice thermal conductivity. Moreover, a maximum power generation efficiency of ~2.7% can be acquired in a single-leg device. Our study develops a n-type sulfide PbSnS2 with high performance, which is a potential candidate to match the excellent p-type SnS.

The anticancer effect of EGFR-targeting artificial microRNA controlled by SLPI promoter in nasopharyngeal carcinoma.

BACKGROUND: This study intends to use artificial microRNA (recombinant adenovirus vector) targeting epidermal growth factor receptor (EGFR) to inhibit the overexpressed EGFR in nasopharyngeal carcinoma, thereby inhibiting the proliferation and metastasis of nasopharyngeal carcinoma. METHOD: The research group verified the expression of EGFR in nasopharyngeal carcinoma through databases, clinical tissues, and cellular pathways. The team first tested the transfection of the recombinant adenovirus by fluorescence microscopy. After adenovirus treatment with different multiplicity of infection (MOI), EGFR level and cell viability in cells were examined by Western blot and MTT assay. Next, the effects of adenovirus (Ad)-SLPI-EGFR on cell proliferation, migration, apoptosis, and related proteins were sequentially examined by EdU, scratch, Transwell, and Western blot. In vivo experiments were performed to evaluate the biological function of EGFR in nasopharyngeal carcinoma. RESULT: All three validation pathways showed the increase in EGFR expression in nasopharyngeal carcinoma. Transfection tests showed that the SLPI promoter was specific in CNE2 cells. With the increase in MOI, the inhibition of EGFR expression and cancer cell viability by Ad-SLPI-EGFR was enhanced. Meanwhile, Ad-SLPI-EGFR effectively reduced the proliferation and metastasis of CNE2 cells and affected the expression of related proteins. Furthermore, Ad-SLPI-EGFR inhibited the invasion and metastasis of nasopharyngeal carcinoma in vivo. CONCLUSION: Ad-SLPI-EGFR inhibits the expression of EGFR in nasopharyngeal carcinoma cells, and finally achieves the purpose of inhibiting the proliferation and metastasis of cancer cells, which may provide novel targeted intervention for the treatment of nasopharyngeal carcinoma.

Multiple valence bands convergence and strong phonon scattering lead to high thermoelectric performance in p-type PbSe.

Thermoelectric generators enable the conversion of waste heat to electricity, which is an effective way to alleviate the global energy crisis. However, the inefficiency of thermoelectric materials is the main obstacle for realizing their widespread applications and thus developing materials with high thermoelectric performance is urgent. Here we show that multiple valence bands and strong phonon scattering can be realized simultaneously in p-type PbSe through the incorporation of AgInSe2. The multiple valleys enable large weighted mobility, indicating enhanced electrical properties. Abundant nano-scale precipitates and dislocations result in strong phonon scattering and thus ultralow lattice thermal conductivity. Consequently, we achieve an exceptional ZT of ~ 1.9 at 873 K in p-type PbSe. This work demonstrates that a combination of band manipulation and microstructure engineering can be realized by tuning the composition, which is expected to be a general strategy for improving the thermoelectric performance in bulk materials.

Mechanically Induced Highly Efficient Hydrogen Evolution from Water over Piezoelectric SnSe nanosheets.

Piezoelectric nanomaterials open new avenues in driving green catalysis processes (e.g., H2 evolution from water) through harvesting mechanical energy, but their catalytic efficiency is still limited. The predicted enormous piezoelectricity for 2D SnSe, together with its high charge mobility and excellent flexibility, renders it an ideal candidate for stimulating piezocatalysis redox reactions. In this work, few-layer piezoelectric SnSe nanosheets (NSs) are utilized for mechanically induced H2 evolution from water. The finite elemental method simulation demonstrates an unprecedent maximal piezoelectric potential of 44.1 V for a single SnSe NS under a pressure of 100 MPa. A record-breaking piezocurrent density of 0.3 mA cm-2 is obtained for SnSe NSs-based electrode under ultrasonic excitation (100 W, 45 kHz), which is about three orders of magnitude greater than that of reported piezocatalysts. Moreover, an exceptional H2 production rate of 948.4 µmol g-1 h-1 is achieved over the SnSe NSs without any cocatalyst, far exceeding most of the reported piezocatalysts and competitive with the current photocatalysis technology. The findings not only enrich the potential piezocatalysis materials, but also provide useful guidance toward high-efficiency mechanically driven chemical reactions such as H2 evolution from water.

High thermoelectric performance realized through manipulating layered phonon-electron decoupling.

Thermoelectric materials allow for direct conversion between heat and electricity, offering the potential for power generation. The average dimensionless figure of merit ZTave determines device efficiency. N-type tin selenide crystals exhibit outstanding three-dimensional charge and two-dimensional phonon transport along the out-of-plane direction, contributing to a high maximum figure of merit Zmax of ~3.6 × 10-3 per kelvin but a moderate ZTave of ~1.1. We found an attractive high Zmax of ~4.1 × 10-3 per kelvin at 748 kelvin and a ZTave of ~1.7 at 300 to 773 kelvin in chlorine-doped and lead-alloyed tin selenide crystals by phonon-electron decoupling. The chlorine-induced low deformation potential improved the carrier mobility. The lead-induced mass and strain fluctuations reduced the lattice thermal conductivity. Phonon-electron decoupling plays a critical role to achieve high-performance thermoelectrics.