Magnetic Switching of Second-Harmonic Generation from Single Cerium-Based Coordination Polymer Microcrystals.

Conventional access and modulation of second-harmonic generation (SHG) require precise control of crystal orientation, which faces great mechanical challenges in the case of micro/nanocrystals. Here, we demonstrate the magnetic-field-tunable SHG performance of lanthanide coordination polymer (Ce-BTC CP) microcrystals through field-aligned orientations. The coordination of Ce ions and organic ligands constructs a noncentrosymmetric structure, which not only contributes to a favorable powder SHG efficiency 3.2 times larger than that of the benchmark KH2PO4 (KDP) but also endows the microcrystals with strong magnetic anisotropy. The SHG efficiency (∼0 to 10 × KDP) depends on the orientation of the crystallographic c-axis, whereas magnetic anisotropy always aligns the c-axis with the magnetic field at a specific angle. Accordingly, the SHG can be magnetically switched by field-induced alignments. The adsorption of dyes by Ce-BTC CPs further facilitates the magnetic switching of multicolor fluorescence that can be excited by the SHG. Our work provides a new pathway for achieving SHG modulation at the microscopic level.

Unexpected longer T1 lifetime of 6-sulfur guanine than 6-selenium guanine: the solvent effect of hydrogen bonds to brake the triplet decay.

The decay of the T1 state to the ground state is an essential property of photosensitizers because it decides the lifetime of excited states and, thus, the time window for sensitization. The sulfur/selenium substitution of carbonyl groups can red-shift absorption spectra and enhance the triplet yield because of the large spin-orbit coupling, modifying nucleobases to potential photosensitizers for various applications. However, replacing sulfur with selenium will also cause a much shorter T1 lifetime. Experimental studies found that the triplet decay rate of 6-seleno guanine (6SeGua) is 835 times faster than that of 6-thio guanine (6tGua) in aqueous solution. In this work, we reveal the mechanism of the T1 decay difference between 6SeGua and 6tGua by computing the activation energy and spin-orbit coupling for rate calculation. The solvent effect of water is treated with explicit microsolvation and implicit solvent models. We find that the hydrogen bond between the sulfur atom of 6tGua and the water molecule can brake the triplet decay, which is weaker in 6SeGua. This difference is crucial to explain the relatively long T1 lifetime of 6tGua in an aqueous solution. This insight emphasizes the role of solvents in modulating the excited state dynamics and the efficiency of photosensitizers, particularly in aqueous environments.

Two Metastable Endohedral Metallofullerenes Sc2C2@C1(39656)-C82 and Sc2C2@C1(51383)-C84: Direct-C2-Insertion Products from Their Most Stable Precursors.

Endohedral metallofullerenes (EMFs) are sub-nano carbon materials with diverse applications, yet their formation mechanism, particularly for metastable isomers, remains ambiguous. The current theoretical methods focus mainly on the most stable isomers, leading to limited predictability of metastable ones due to their low stabilities and yields. Herein, we report the successful isolation and characterization of two metastable EMFs, Sc2C2@C1(39656)-C82 and Sc2C2@C1(51383)-C84, which violate the isolated pentagon rule (IPR). These two non-IPR EMFs exhibit a rare case of planar and pennant-like Sc2C2 clusters, which can be considered hybrids of the common butterfly-shaped and linear configurations. More importantly, the theoretical results reveal that despite being metastable, these two non-IPR EMFs survived as the products from their most stable precursors, Sc2C2@C2v(5)-C80 and Sc2C2@Cs(6)-C82, via a C2 insertion during the post-formation annealing stages. We propose a systematic theoretical method for predicting metastable EMFs during the post-formation stages. The unambiguous molecular-level structural evidence, combined with the theoretical calculation results, provides valuable insights into the formation mechanisms of EMFs, shedding light on the potential of post-formation mechanisms as a promising approach for EMF synthesis.

Capturing nonclassical C70 with double heptagons in low-pressure combustion.

A double-heptagon-containing C70H6 (dihept-C70H6) was isolated and unambiguously characterized in the soot of low-pressure combustion, which shares the identical heptagonal cage as dihept-C70Cl6 previously identified in the products of carbon arc, and thus represents the first nonclassical fullerene isolable in both carbon arc and combustion.

A General Electrodeposition Strategy for Fabricating Ultrathin Nickel Cobalt Phosphate Nanosheets with Ultrahigh Capacity and Rate Performance.

Transition-metal phosphates/phosphides possess promising theoretical electrochemical characteristics and exhibit great potential in advanced supercapacitors. Unfortunately, limited by the processing techniques and overall structure, their specific capacity and rate performance are still unsatisfactory. Herein, we report the fabrication of transition-metal phosphate electrodes with an ultrathin sheetlike array structure by one-step electrodeposition at room temperature. As a proof-of-concept, a transition-metal phosphate member of NiCo(HPO4)2·3H2O with an ultrathin nanosheet structure (thickness ∼2.3 nm) was synthesized and investigated. The as-prepared NiCo(HPO4)2·3H2O electrode showcases an ultrahigh specific capacity of 1768.5 C g-1 at 2 A g-1 (the highest value for transition-metal phosphates/phosphides reported to date), superb rate performance of 1144.8 C g-1 at 100 A g-1, and excellent electrochemical stability. Moreover, the transition-metal phosphate nanosheet array can be uniformly deposited on various conductive substrates, demonstrating the generality of our strategy. Therefore, this simple electrodeposition strategy provides an opportunity to fabricate ultrathin transition-metal phosphate nanosheet materials that can be used for energy storage/conversion, electrocatalysis, and other electrochemical energy-related devices.

Hierarchical Nanosheets/Walls Structured Carbon-Coated Porous Vanadium Nitride Anodes Enable Wide-Voltage-Window Aqueous Asymmetric Supercapacitors with High Energy Density.

The energy density of aqueous asymmetric supercapacitors (ASCs) is usually limited by low potential windows and capacitances of both anode and cathode. Herein, a facile strategy to fabricate hierarchical carbon-coated porous vanadium nitride nanosheet arrays on vertically aligned carbon walls (CC/CW/p-VN@C) as anode for aqueous ASCs is reported. The potential window of CC/CW/p-VN@C electrode can be stably extended to -1.3 to 0 V (vs Ag/AgCl) with greatly improved specific capacitance (604.8 F g-1 at 1 A g-1), excellent rate capability (368 F g-1 at 60 A g-1), and remarkable electrochemical stability. To construct ASCs, a Birnessite Na0.5MnO2 nanosheet arrays (CC/CW/Na0.5MnO2) cathode is similarly built. Benefiting from the matchable potential windows and high specific capacitances of the rationally designed anode and cathode, aqueous CC/CW/p-VN@C||CC/CW/Na0.5MnO2 ASCs with a wide voltage window of 2.6 V are fabricated. Moreover, the ASCs showcase an ultrahigh energy density up to 96.7 W h kg-1 at a high power density of 1294 W kg-1, and excellent cycling stability (92.5% retention after 10 000 cycles), outperforming most of previously reported ASCs and even comparable to that of organic electrolyte supercapacitors (SCs). This efficient strategy for fabricating 2.6 V aqueous ASCs suggests a promising research system for high energy density SCs.

Expression of the recepteur d'originenantais receptor tyrosine kinase in non-small cell lung cancer and its clinical significance.

BACKGROUND: Recepteur d'originenantais (RON) is a receptor tyrosine kinase (RTK) that belongs to the MET proto-oncogene family. The aim of this study was to investigate the expression of RON receptor tyrosine kinase in human non-small cell lung cancer (NSCLC) and its relationship with clinical pathology of NSCLC and prognosis. METHODS: RON protein expression by immunohistochemistry (IHC) in 96 NSCLC specimens was evaluated and compared with the clinical pathology and prognosis, and 20 para-neoplastic tissues were included as controls. RON mRNA and protein expression in 25 fresh tissue samples of lung cancer and 10 normal lung tissues were also analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. RESULTS: The rate of positive RON expression differed significantly between NSCLC tissues (55.2%, 53/96) and para-neoplastic tissues (5%, 1/20) (P < 0.001). RON protein expression was not found to be associated with gender or age. However, RON expression positively correlated with clinical TNM stage (P = 0.004), histological types (P = 0.001), lymph node metastasis (P = 0.012) and differentiation (P = 0.035). RT-PCR and Western blotting analysis also confirmed that the expression of RON mRNA and protein was significantly increased in the NSCLC tissues versus normal tissues. In addition, RON expression was associated with a poor prognosis for patients with NSCLC (P = 0.045). CONCLUSIONS: The expression of RON protein and mRNA is significant in human NSCLC and low in para-neoplastic and normal tissues. Elevated RON expression may contribute to the occurrence, progression and metastasis of NSCLC, inferring that it could be useful as a new prognostic indicator for patients with NSCLC.