H/F Substitution Achieved Enantiomeric Organic Inorganic Hybrid Perovskites and Trigonal Structure [DMFP]3(CdBr3)(CdBr4).

Organic-inorganic hybrid perovskites (OIHPs) have been emerging as a hot research topic due to their potential applications in energy storage, semiconductors, and electronic devices. Herein, we systematically investigated the synthesis and phase transition behaviors of the enantiomeric OIHPs, (R) and (S)-N,N-dimethyl-3-fluoropyrrolidinium cadmium bromide ([DMFP][CdBr3]), and the hybrid trigonal structure [DMFP]3 (CdBr3)(CdBr4). The enantiomers have a mirror-symmetric structure and enhanced solid-state phase transition points of 417 and 443 K, in contrast to the nonfluorinated parent compound, N,N-dimethyl-pyrrolidinium cadmium bromide ([DMP][CdBr3], 385 K). Moreover, racemic H/F substitution on the pyrrolidinium cations leads to the formation of a trigonal compound, showing above-room-temperature structural phase transition and dominant ferroelasticity. This work discovers chiral enantiomeric OIHPs through H/F substitution, demonstrating a useful chemical synthesis strategy for exploring novel phase transition materials.

H/F Substitution on the Spacer Cations Leads to 1D-to-2D Increment of the Pyrrolidinium-Containing Lead Iodide Hybrid Perovskites.

Hybrid organic-inorganic perovskites (HOIPs) have emerged as multifunctional materials with remarkable optical and electronic properties. In particular, 2D-layered lead iodide-based HOIPs possess great practical application potential in the photoelectric field. In this work, we report H/F substitution-induced 1D-to-2D increment of lead iodide HOIPs. The enantiomeric HOIPs, S- and R-FPPbI3 (FP = 3-fluoropyrrolidinium), were achieved by monofluoride substitution on the spacer cations of the parent HOIP, PyPbI3 (Py = pyrrolidinium), showing mirror image structural relationship and reversible solid-state phase transition. A 2D-layered HOIP, (DFP)2PbI4 (DFP = 3,3-difluoropyrrolidinium), was achieved with a low band gap of 2.09 eV through difluoride substitution, thanks to the expansion of the Pb-I network from 1D to 2D. This work highlights the exploration of 1D chiral and 2D-layered HOIP materials with reversible phase transitions through H/F substitution strategies.

Optical Control of Polarization Switching in a Single-Component Organic Ferroelectric Crystal.

The optical control of polarization switching is attracting tremendous interest because photoirradiation stands out as a nondestructive, noncontact, and remote-control means beyond an electric or strain field. The current research mainly uses various photoexcited electronic effects to achieve the photocontrol polarization, such as a light-driven flexoelectric effect and a photovoltaic effect. However, since photochromism was discovered in 1867, the structural phase transition caused by photoisomerization has never been associated with ferroelectricity. Here, we successfully synthesized an organic photochromic ferroelectric with polar space group Pna21, 3,4,5-trifluoro-N-(3,5-di-tert-butylsalicylidene)aniline, whose color can change between yellow and orange via laser illumination. Its dielectric permittivity and spontaneous polarization can be switched reversibly with a photoinduced phase transition triggered by structural photoisomerization between the enol form and the trans-keto form. To our knowledge, this is the first photoswitchable ferroelectric crystal to achieve polarization switching through a structural phase transition triggered by photoisomerization. This finding paves the way toward photocontrol of smart materials and biomechanical applications in the future.

Target Designing Phase Transition Materials through Halogen Substitution.

Crystalline materials have received extensive attention due to their extraordinary physical and chemical properties. Among them, phase transition materials have attracted great attention in the fields of photovoltaic, switchable dielectric devices, and ferroelectric memories, etc. However, many of them suffer from low phase transition temperatures, which limits their practical application. In this work, we systematically designed crystalline materials, (TMXM)2 PtCl6 (X=F, Cl, Br, I) through halogen substitution on the cations, aiming to improving phase transition temperature. The resulting phase transition of (TMXM)2 PtCl6 (X=F, Cl, Br, I) get a significant enhancement, compared to the parent compound [(CH3 )4 N]2 PtCl6 ((TM)2 PtCl6 ). Such phase transition temperature enhancement can be attributed to the introduction of halogen atoms that increase the potential energy barrier of the cation rotation. In addition, (TMBM)2 PtCl6 and (TMIM)2 PtCl6 have a low symmetry and crystallize in the space group C2 /c and P21 21 21 , respectively. This work highlights the halogen substitution in designing crystal materials with high phase transition temperature.

Homochiral Nickel Nitrite ABX3 (X = NO2-) Perovskite Ferroelectrics.

Chiral organic-inorganic perovskites (COIPs) have recently attracted increasing interest due to their unique inherent chirality and potential applications in next-generation optoelectronic and spintronic devices. However, COIP ferroelectrics are very sparse. In this work, for the first time, we present the nickel-nitrite ABX3 COIP ferroelectrics, [(R and S)-N-fluoromethyl-3-quinuclidinol]Ni(NO2)3 ([(R and S)-FMQ]Ni(NO2)3), where the X-site is the rarely seen NO2- bridging ligand. [(R and S)-FMQ]Ni(NO2)3 display mirror-relationship in the crystal structure and vibrational circular dichroism signal. It is emphasized that [(R and S)-FMQ]Ni(NO2)3 show splendid ferroelectricity with both an extremely high phase-transition point of 405 K and a spontaneous polarization of 12 µC/cm2. To our knowledge, [(R and S)-FMQ]Ni(NO2)3 are the first examples of nickel-nitrite based COIP ferroelectrics. This finding expands the COIP family and throws light on exploration of high-performance COIP ferroelectrics.

An investigation into the HIF-dependent intestinal barrier protective mechanism of Qingchang Wenzhong decoction in ulcerative colitis management.

ETHNOPHARMACOLOGICAL RELEVANCE: Ulcerative colitis (UC) is a chronic, non-specific inflammatory disease affecting the colon and rectum with an etiology that remains elusive. Traditional Chinese medicine (TCM) has been widely used on long-term UC treatment to better maintain the efficacy than traditional aminosalicylic acid or glucocorticosteroids and to ease financial burden of patients. Qingchang Wenzhong Decoction (QCWZD) is a modern TCM decoction with established clinical efficacy but the mechanism of its protection on intestinal barrier function remains unclear. AIM OF THE STUDY: Current findings highlight that the activation of the hypoxia inducible factor (HIF) pathway can facilitate the repair of intestinal epithelium barrier. This study is to investigate the protective effects of QCWZD and its HIF-targeted ingredients on hypoxia-dependent intestinal barrier. METHODS: The mice model of UC was induced by dextran sulfate sodium (DSS). Disease activity index (DAI) and histopathology scores and colon length were used to measure the severity of colitis. The DAO activity in serum and protein expression of tight junction (TJ) proteins were detected to explore the function of intestinal barrier. The protein levels of HIF-1α and its downstream gene heme oxygenase-1 (HO-1) were measured as well. HIF-targeted active ingredients in QCWZD were selected by network pharmacology and molecular docking. Protective effects of six constituents on HIF-related anti-oxidative and barrier protective pathway were evaluated by lipopolysaccharide (LPS)-induced HT29 and RAW264.7 cells, through the measurement of the production of ROS and mRNA level of pro-inflammatory cytokines. HIF-1α knockdown was carried out to explore the correlation of protection effects with HIF-related pathway of the active ingredients. RESULTS: QCWZD effectively alleviated colitis induced by DSS and demonstrated a protective effect on intestinal barrier function by upregulating HIF-related pathways. Six specific ingredients in QCWZD, targeting HIF, successfully reduced the production of cellular ROS and proinflammatory cytokines in LPS-induced cells. It is noteworthy that the barrier protection provided by these molecules is intricately linked with the HIF-related pathway. CONCLUSIONS: This study elucidates the HIF-related molecular mechanism of QCWZD in protecting the function of the epithelial barrier. Six compounds targeting the activation of the HIF-dependent pathway were demonstrated to unveil a novel therapeutic approach for managing UC.

EGFR Oncogenic Mutations in NSCLC Impair Macrophage Phagocytosis and Mediate Innate Immune Evasion Through Up-Regulation of CD47.

INTRODUCTION: EGFR-mutated NSCLC is characterized by an immunosuppressive microenvironment that confers limited clinical effectiveness to anti-PD-1 or PD-L1 antibodies. Despite the discouraging outcomes of immunotherapy, novel immune checkpoints are constantly emerging, among which the specific vulnerability for therapeutic intervention in the context of EGFR-mutated NSCLC remains unresolved. METHODS: Data sets of patient- and cell line-levels were used for screening and mutual validation of association between EGFR mutation and a panel of immune checkpoint-related genes. Regulatory mechanism was elucidated through in vitro manipulation of EGFR signaling pathway and evaluated by immunoblot analysis, quantitative polymerase chain reaction, flow cytometry, immunofluorescence staining, and chromatin immunoprecipitation. In vivo investigation of different therapeutic strategies were conducted using both immunocompetent and immunodeficient mouse models. RESULTS: Among all screened immune checkpoints, CD47 emerged as the candidate most relevant to EGFR activation. Mechanistically, EGFR mutation constitutively activated downstream ERK and AKT pathways to respectively up-regulate the transcriptional factors c-Myc and NF-κB, both of which structurally bound to the promotor region of CD47 and actively transcribed this "don't eat me" signal. Impaired macrophage phagocytosis was observed on introduction of EGFR-sensitizing mutations in NSCLC cell line models, whereas CD47 blockade restored the phagocytic capacity and augmented tumor cell killing in both in vitro and in vivo models. Remarkably, the combination of anti-CD47 antibody with EGFR tyrosine kinase inhibitor revealed an additive antitumor activity compared with monotherapy of either antitumor agent in both immunocompetent and adaptive immunity-deficient mouse models. CONCLUSIONS: EGFR-sensitizing mutation facilitates NSCLC's escape from innate immune attack through up-regulating CD47. Combination therapy incorporating CD47 blockade holds substantial promise for clinical translation in developing more effective therapeutic approaches against EGFR-mutant NSCLC.

An organic plastic ferroelectric with high Curie point.

Plastic ferroelectrics, featuring large entropy changes in phase transitions, hold great potential application for solid-state refrigeration due to the electrocaloric effect. Although conventional ceramic ferroelectrics (e.g., BaTiO3 and KNbO3) have been widely investigated in the fields of electrocaloric material and catalysis, organic plastic ferroelectrics with a high Curie point (T c) are rarely reported but are of great importance for the sake of environmental protection. Here, we reported an organic plastic ferroelectric, (-)-camphanic acid, which crystallizes in the P21 space group, chiral polar 2 (C2) point group, at room temperature. It undergoes plastic paraelectric-to-ferroelectric phase transition with the Aizu notation of 23F2 and high T c of 414 K, showing large entropy gain (ΔS t = 48.2 J K-1 mol-1). More importantly, the rectangular polarization-electric field (P-E) hysteresis loop was recorded on the thin film samples with a large saturated polarization (P s) of 5.2 µC cm-2. The plastic phase transition is responsible for its multiaxial ferroelectric feature. This work highlights the discovery of organic multiaxial ferroelectrics driven by the motive of combining chirality and plastic phase transition, which will extensively promote the practical application of such unique functional materials.

Highest-Tc organic enantiomeric ferroelectrics obtained by F/H substitution.

Through the strategy of F/H substitution, we precisely designed the highest-Tc (phase transition temperature) organic enantiomeric ferroelectrics, (R)- and (S)-(N,N-dimethyl-3-fluoropyrrolidinium) iodide, of which the Tc reaches up to 470 K, far beyond those of other enantiomeric ferroelectrics and also the commercial ferroelectric BaTiO3.

[Synthesis of hydroxyapatite/magnetite/zeolite composite for Congo red removal from aqueous solution].

In this study, a novel hydroxyapatite/magnetite/zeolite (HAP/Fe3O4/Zeo) composite was prepared, characterized and used as an adsorbent to remove Congo red (CR) from aqueous solution. The adsorption characteristics of CR from aqueous solution on the HAP/Fe3O4/Zeo composite were investigated using batch experiments. Results showed that the HAP/Fe3O4/Zeo composite was effective for the removal of CR from aqueous solution. The CR adsorption capacity for the HAP/Fe3O4/Zeo composite decreased with solution pH increasing from 3 to 4 or solution pH increasing from 7 to 11, and remained basically unchanged with pH increasing from 4 to 7. The CR removal efficiency of the HAP/Fe3O4/Zeo composite increased with increasing adsorbent dosage, while the amount of CR adsorbed on the HAP/Fe3O4/Zeo composite decreased with increasing adsorbent dosage. The adsorption kinetic data of CR on the HAP/Fe3O4/Zeo composite well fitted a pseudo-second-order model. The equilibrium adsorption data of CR on the HAP/Fe3O4/Zeo composite could be described by the Langmuir and Freundlich isotherm models. The maximum monolayer adsorption capacity for CR derived from the Langmuir isotherm model was determined to be 117 mg x g(-1) at pH 7 and 303 K. The adsorption process of CR on the HAP/Fe3O4/Zeo composite was spontaneous and endothermic. The main mechanisms for the adsorption of CR on the HAP/Fe3O4/Zeo composite at pH 7 included surface complexation, hydrogen bonding and Lewis acid-base reaction. Thermal regeneration showed that the HAP/Fe3O4/Zeo composite could be used for five desorption-adsorption cycles with high removal efficiency for CR in each cycle. X-ray diffraction (XRD) analysis revealed that the HAP/Fe3O4/zeolite composite contained Fe3O4, and this composite had relatively high saturation magnetization. The HAP/Fe3O4/Zeo composite adsorbed with CR could be collected from aqueous solution under an external magnetic field quickly. Results of this study suggested that the HAP/Fe3O4/Zeo composite should be applicable for the removal of CR from wastewater.

[Removal of nitrate from aqueous solution using cetylpyridinium chloride (CPC)-modified activated carbon as the adsorbent].

Surfactant-modified activated carbon (SMAC) was prepared by loading cetylpyridinium chloride (CPC) onto activated carbon and used as adsorbents to remove nitrate from aqueous solution. The SMAC was effective for removing nitrate from aqueous solution. The SMAC exhibited much higher nitrate adsorption capacity than that of the unmodified activated carbon. The nitrate adsorption capacity for SMAC increased with increasing the CPC loading. The adsorption kinetics of nitrate on SMAC followed a pseudo-second-order kinetic model. The equilibrium adsorption data of nitrate on SMAC could be described by the Langmuir isotherm model. Based on the Langmuir isotherm model, the maximum nitrate adsorption capacity for SMAC with CPC loading amount of444 mmol per 1 kg activated carbon was determined to be 16.1 mg x g(-1). The nitrate adsorption capacity for SMAC decreased with the increasing solution pH. The presence of competing anions such as chloride, sulfate and bicarbonate reduced the nitrate adsorption capacity. The nitrate adsorption capacity for SMAC slightly decreased with the increasing reaction temperature. Almost 95% of nitrate molecules adsorbed on SMAC could be desorbed in 1 mol x L(-1) NaCl solution. The main mechanisms for the adsorption of nitrate on SMAC are anionic exchange and electrostatic attraction. The results of this work indicate that SMAC is a promising adsorbent for removing nitrate from aqueous solution.