Organic-Inorganic Hybrid Ferroelectric and Antiferroelectric with Afterglow Emission.

Luminescent ferroelectrics are holding exciting prospect for integrated photoelectronic devices due to potential light-polarization interactions at electron scale. Integrating ferroelectricity and long-lived afterglow emission in a single material would offer new possibilities for fundamental research and applications, however, related reports have been a blank to date. For the first time, we here achieved the combination of notable ferroelectricity and afterglow emission in an organic-inorganic hybrid material. Remarkably, the presented (4-methylpiperidium)CdCl3 also shows noticeable antiferroelectric behavior. The implementation of cationic customization and halogen engineering not only enables a dramatic enhancement of Curie temperature of 114.4 K but also brings a record longest emission lifetime up to 117.11 ms under ambient conditions, realizing a leapfrog improvement of at least two orders of magnitude compared to reported hybrid ferroelectrics so far. This finding would herald the emergence of novel application potential, such as multi-level density data storage or multifunctional sensors, towards the future integrated optoelectronic devices with multitasking capabilities.

Abietane diterpenoids with anti-inflammatory activities from Callicarpa bodinieri.

Nine undescribed abietane diterpenoids (1-9) and eleven known abietane analogs (10-20) were isolated from Callicarpa bodinieri. Their structures were characterized by interpreting spectroscopic data, X-ray crystallography, and ECD analysis. The anti-inflammatory activities of these compounds were tested by evaluation of their inhibitory effect on NO production by lipopolysaccharide in RAW 264.7 macrophages, and compounds 3 and 8 exhibited potent anti-inflammatory activities with IC50 values of 36.35 ± 1.12 and 37.21 ± 0.92 µM. The western blotting studies demonstrated that compound 3 inhibited the expression of nitric oxide synthase and p65 that involved in the NF-κB pathway.

Anti-inflammatory ent-cleistanthane-type diterpenoids from Phyllanthus rheophyticus.

A bioactivity-guided isolation from the aerial parts of Phyllanthus rheophyticus obtained 17 undescribed ent-cleistanthane-type diterpenoids, namely phyllarheophols A-Q, as well as 12 known analogs. Their structures were characterized by a combination of spectroscopic data interpretation, single-crystal X-ray diffraction and ECD analysis. The anti-inflammatory activities of these compounds were evaluated by measuring their inhibitory effects on NO production in LPS-stimulated RAW264.7 macrophages, and their preliminary structure-activity relationships were also discussed. Further study showed that promising compounds phyllarheophol D and phyacioid B significantly suppressed the expressions of cytokines and nitric oxide synthase through the NF-κB signaling pathway.

Diterpenoids with an unusual tricyclo[10.3.0.02,9]pentadecane skeleton from Pedilanthus tithymaloides as multidrug resistance modulators.

Three new diterpenoids with an unusual carbon skeleton, pedilanins A-C (1-3), and nine new jatrophane diterpenoids, pedilanins D-L (4-12), along with five known ones (13-17), were isolated from Pedilanthus tithymaloides. Compounds 1-3 characterize an unprecedented tricyclo[10.3.0.02,9]pentadecane skeleton. Compounds 4-8 are rare examples of the jatrophanes bearing a cyclic hemiketal substructure. Their structures were determined by an extensive analysis of HRESIMS, NMR, quantum-chemical calculation, DP4+ probability, and X-ray crystallographic data. In the bioassay, compounds 1-12 dramatically reversed multidrug resistance in cancer cells with the fold-reversals ranging from 17.9 to 396.8 at the noncytotoxic concentration of 10 µM. The mechanism results indicated that compounds 2 and 3 inhibited the P-glycoprotein (Pgp) transporter function, thus reversing the drug resistance.

Euphohelides A-C, ent-Abietane-Type Norditerpene Lactones from Euphorbia helioscopia and Their Anti-Inflammatory Activities.

Three unreported ent-abietane-type norditerpene lactones, euphohelides A-C (1-3), and 11 known analogs (4-14) were isolated from the whole plants of Euphorbia helioscopia L. Euphohelide A (1) is an unprecedented 2-nor-ent-abietane lactone bearing a unique 5/6/6/5 tetracyclic system. Euphohelides B (2) and C (3) possess 2-nor-6/6/6/5 and 2,3-dinor-5/6/6/5 dilactone tetracyclic moieties, respectively. Their structures were established by spectroscopic methods, computational ECD, and X-ray crystallographic analyses. A biomimetic synthesis of 1 was achieved from precursor 4 based on the speculative biogenetic pathway. Compounds 1 and 5 significantly alleviated the release of LPS-induced NO with IC50 values of 32.98 ± 1.13 and 33.82 ± 3.25 µM, which might be related to the regulation of the NF-κB signaling pathway.

Nicotinic acid bromide: a simple organic salt optical-electrical ferroelastic with high Tc.

A new ferroelastic organic salt nicotinic acid bromide (N-Br) was connected by hydrogen bonding with nicotinic acid cations via a halogen substitution strategy. It exhibits a ferroelastic phase transition from P21/m to P1̄ with 2/mF1̄ Aizu notation with a high Curie temperature (Tc) of 402 K. Moreover, optical regulation from blue light to white light was achieved by halogen substitution.

Metal ion induced dual switchable dielectric and luminescent properties in hybrid halides.

A new multi-functional organic-inorganic hybrid compound was successfully obtained by regulating metal halides. Apart from excellent luminescence properties, in particular, the introduction of a Mn halide successfully achieved a dual-switchable dielectric property, which could lead to very interesting exploration in sensors.

Ferroelasticity in Organic-Inorganic Hybrid Perovskites.

Molecular ferroelastics have received particular attention for potential applications in mechanical switches, shape memory, energy conversion, information processing, and solar cells, by taking advantages of their low-cost, light-weight, easy preparation, and mechanical flexibility. The unique structures of organic-inorganic hybrid perovskites have been considered to be a design platform for symmetry-breaking-associated order-disorder in lattice, thereby possessing great potential for ferroelastic phase transition. Herein, we review the research progress of organic-inorganic hybrid perovskite ferroelastics in recent years, focusing on the crystal structures, dimensions, phase transitions and ferroelastic properties. In view of the few reports on molecular-based hybrid ferroelastics, we look forward to the structural design strategies of molecular ferroelastic materials, as well as the opportunities and challenges faced by molecular-based hybrid ferroelastic materials in the future. This review will have positive guiding significance for the synthesis and future exploration of organic-inorganic hybrid molecular ferroelastics.

The construction of a two-dimensional organic-inorganic hybrid double perovskite ferroelastic with a high T c and narrow band gap.

Two-dimensional (2D) hybrid double perovskites have attracted extensive research interest for their fascinating physical properties, such as ferroelectricity, X-ray detection, light response and so on. In addition, ferroelastics, as an important branch of ferroic materials, exhibits wide prospects in mechanical switches, shape memory and templating electronic nanostructures. Here, we designed a 2D phase-transition double perovskite ferroelastic through a structurally progressive strategy. This evolution is core to our construction process from 0D to 1D and AgBi-based 2D. In this way, we successfully synthesized 2D lead-free ferroelastic (DPA)4AgBiBr8 (DPA = 2,2-dimethylpropan-1-aminium) with a high Curie temperature (T c), which shows a narrower band gap than 0D (DPA)4Bi2Br10 and 1D (DPA)5Pb2Br9. Moreover, the mechanism of structural phase transition and molecular motion are fully characterized by temperature dependent solid-state NMR and single crystal XRD. (DPA)4AgBiBr8 injects power into the discovery of new ferroelastics or the construction and dimensional adjustment in new hybrid double perovskites.

Thermally stimuli-responsive materials with transformable double channels of nonlinear optical and dielectric properties.

Organic-inorganic hybrid materials have received extensive attention and in-depth research in the past few decades due to their superior properties and potential applications in storage, sensing, dielectric switches, actuators and other information fields. Based on this scientific background, we developed two organic-inorganic hybrids [TMFEA]2CdI4 (compound 1) and [TMFEA]2ZnI4 (compound 2) (TMFEA = trimethylfluoroethylammonium). Both compounds show transformable double channels of nonlinear optical and dielectric properties induced by structural phase transitions, which was proved by the thermal, nonlinear optical, and dielectric phase changes. In addition, the channels can be switched ON and OFF by temperature regulation. This work will provide inspiration and options for the exploration of opto-electrical dual channel components.

Jatrolignans C and D: New Neolignan Epimers from Jatropha curcas.

Two new neolignans jatrolignans, C (1) and D (2), a pair of epimers, were isolated from the whole plants of Jatropha curcas L. (Euphorbiaceae). Their structures were determined with HRESIMS, IR, and NMR data analysis, and electronic circular dichroism (ECD) experiments via a comparison of the experimental and the calculated ECD spectra. Their antichlamydial activity was evaluated in Chlamydia abortus. They both showed dose-dependent antichlamydial effects. Significant growth inhibitory effects were observed at a minimum concentration of 40 µM.

Dehydration-activated structural phase transition in a two-dimensional hybrid double perovskite.

As a feasible lead-free scheme, organic-inorganic hybrid double perovskites show many excellent properties, including ferroelectricity, ferroelasticity, self-powered circularly polarized light detection and so on. In this work, the solid-to-solid structural phase transition of a two-dimensional hybrid double perovskite (CHA)4CuBiI8 was successfully activated via the dehydration of (CHA)4CuBiI8·H2O, which was proven by differential scanning calorimetry (DSC) and temperature-dependent dielectric measurements. Using variable-temperature single-crystal X-ray diffractometry, the cause behind the phase transition of (CHA)4CuBiI8 was determined to be the overall coordination of distortion and movement of the inorganic skeleton and thermal deformation of the cationic structure. In addition, the substance after dehydration shows good stability in multiple reversible switching during dielectric tests. The interesting dehydration-activated results of the material contribute towards a further expansion of the properties and potential application of hybrid double perovskites.

Metal ion modulation triggers dielectric double switching and green fluorescence in A2MX4-type compounds.

Multifunctional switching materials show great potential for applications in sensors, smart switches, and other fields due to their ability to integrate different physical channels in one single device. However, multifunctional responsive materials with multiple switching and luminescence properties have rarely been reported. Here, we report three organic-inorganic hybrids: [TMAA]2[CoCl4] (compound 1), [TMAA]2[CdBr4] (compound 2) and [TMAA]2[MnCl4] (compound 3). Compound 1 and compound 2 undergo two reversible phase transitions at high temperature (328.95/359.25 K and 350.45/393.15 K, respectively). Since the inorganic skeleton has a strong influence on the luminescence properties of such structured substances, Cd and Co were replaced with Mn, after which compound 3 was obtained as expected. The above strategy triggered bright green luminescence with a quantum yield of 35.19%, and significantly increased the phase transition temperature of compound 3 to above 400 K. The above results show that the regulation of the inorganic skeleton provides a new strategy for researchers to develop dual phase change/luminous materials.

Cytotoxic cardenolides from Calotropis gigantea.

Sixteen cardiac glycosides, including five previously undescribed compounds, were extracted and purified from whole plants of Calotropis gigantea (L.). Spectroscopic data and electronic circular dichroism (ECD) analyses were used to determine their structures. Calogiganin C is the first naturally occurring example of a cardenolide containing a 7-membered lactone in ring A. The cytotoxic activities of these compounds against A172, U251, AGS, PANC-1, HepG2, HCT116 and NCI-H226 cell lines were evaluated. Four of them exhibited the most potent growth inhibitory activity against a panel of human cancer cell lines, including A172, U251, AGS, PANC-1 and HCT116. Notably, uscharidin and calotropin showed pronounced cytotoxicities at low nanomolar concentrations against A172 and U251 cells, and possible cell death mechanism studies manifested that these two compounds induced G2/M cell cycle arrest, which demonstrated promising anticancer potential.

Observation of Transition from Ferroelasticity to Ferroelectricity by Solvent Selective Effect in Anilinium Bromide.

Organic ferroelectrics are highly desirable for their light weight, mechanical flexibility and biocompatibility. However, the rational design of organic ferroelectrics has always faced great challenges. Anilinium bromide (AB) has two structures reported in the Cambridge Crystallographic Data Centre, which might be an mmmF2/m type ferroelastic (AB-1). When we studied its ferroelasticity, we were surprised to discover that there was another crystal (AB-2) in H2 O besides this one, and they were very difficult to separate. By changing the solvent, we found that AB-1 crystals could be formed in ethanol, where ferroelastic domains were visualized by polarized light microscopy, and AB-2 crystals could be obtained from various crystallization solvents of methanol, isopropanol, N-butanol, acetonitrile, dimethyl sulfoxide, and N,N-dimethylformamide, which undergo a ferroelectric phase transition with mm2Fm, showing clear ferroelectricity in two phases. To our knowledge, the regulation of ferroelasticity to ferroelectricity by solvent selective effect is unprecedented in the field of ferroelectrics. This work reveals the important role of solvent effect in organic ferroelectrics.

Spinal cord injury induced Neuregulin 1 signaling changes in mouse prefrontal cortex and hippocampus.

Accumulated evidence has recently demonstrated that spinal cord injury (SCI) can lead to chronic damage in a wide range of brain regions. Neuregulin 1 (Nrg1) signaling has been broadly recognized as an important mechanism contributing to neural differentiation and regeneration. We here studied the effect of SCI on Nrg1 signaling in prefrontal cortex (PFC) and hippocampus (HIP) in a mouse model. As was indicated by the increased levels of GFAP and Iba-1, our results demonstrated that SCI significantly induced activation of astrocytes and microglial cells in both PFC and HIP. In addition, both western blot and morphological assay demonstrated that Nrg1 was altered in both regions at 8 weeks post SCI, which was accompanied with decreased phosphorylation levels of its cognitive receptors Neu and ErbB4. Our combined results indicated that SCI can influence Nrg1 signaling, which may contribute to the worsening of pathophysiological changes in major brain regions during SCI. These results also suggested that exogenous Nrg1 treatment may have a therapeutic role in counteracting SCI-induced brain damage.

Differential changes in Neuregulin-1 signaling in major brain regions in a lipopolysaccharide-induced neuroinflammation mouse model.

Neuregulin 1 (Nrg1) is involved in multiple biological processes in the nervous system. The present study investigated changes in Nrg1 signaling in the major brain regions of mice subjected to lipopolysaccharide (LPS)-induced neuroinflammation. At 24 h post­intraperitoneal injection of LPS, mouse brain tissues, including tissues from the cortex, striatum, hippocampus and hypothalamus, were collected. Reverse transcription­polymerase chain reaction was used to determine the expression of Nrg1 and its receptors, Neu and ErbB4, at the mRNA level. Western blotting was performed to determine the levels of these proteins and the protein levels of phosphorylated extracellular signal-regulated kinases (Erk)1/2 and Akt1. Immunohistochemical staining was utilized to detect the levels of pNeu and pErbB4 in these regions. LPS successfully induced sites of neuroinflammation in these regions, in which changes in Nrg1, Neu and ErbB4 at the mRNA and protein levels were identified compared with controls. LPS induced a reduction in pNeu and pErbB4 in the striatum and hypothalamus, although marginally increased pErbB4 levels were found in the hippocampus. LPS increased the overall phosphorylation of Src but this effect was reduced in the hypothalamus. Moreover, increased phosphorylation of Akt1 was found in the striatum and hippocampus. These data suggest diverse roles for Nrg1 signaling in these regions during the process of neuroinflammation.

Association of genetic variants in the IRAK-4 gene with susceptibility to severe sepsis.

BACKGROUND: The association of genetic variation in the IRAK-1 gene with sepsis outcome has been proved. However, few studies have addressed the impact of the IRAK-4 gene variants on sepsis risk. This study aimed to determine whether the polymorphisms in the IRAK-4 gene are associated with susceptibility to and prognosis of severe sepsis in the Chinese Han ethnic population. METHODS: In this case-control study, 192 patients with severe sepsis hospitalized in the emergency department of Zhongshan Hospital from February 2006 to December 2009 and 192 healthy volunteers were enrolled. Exclusion criteria included metastatic tumors, autoimmune diseases, AIDS or treatment with immunosuppressive drugs. This study was approved by the ethical committee of Zhongshan Hospital, Fudan University. Sepsis patients were divided into a survival group (n=124) and a non-survival group (n=68) according to the 30-day mortality. Primer 3 software was used to design PCR and sequencing primers. Genomic DNA was extracted from peripheral blood mononuclear cells. Seven tagSNPs in IRAK-4 were selected according to the data of the Chinese Han population in Beijing from the Hapmap project and genotyped by direct sequencing. The chi-square test was used to evaluate the differences in genotype and allele frequencies between the two groups. RESULTS: The distributions of all tagSNPs were consistent with Hardy-Weinberg equilibrium. The allele and genotype frequencies of rs4251545 (G/A) were significantly different between the severe sepsis and healthy control groups (P=0.015, P=0.035, respectively). Carriers of the rs4251545A had a higher risk for severe sepsis compared with carriers of the rs4251545G (OR=1.69, 95% CI: 1.10-2.58). The allele and genotype frequencies of all SNPs were not significantly different between the survival group and non-survival group. CONCLUSION: These findings indicate that the variants in IRAK-4 are significantly associated with susceptibility to severe sepsis in the Chinese Han ethnic population.