From fractional quantum anomalous Hall smectics to polar smectic metals: nontrivial interplay between electronic liquid crystal order and topological order in correlated topological flat bands.

Symmetry-breaking orders can not only compete with each other, but also be intertwined, and the intertwined topological and symmetry-breaking orders make the situation more intriguing. This work examines the archetypal correlated flat band model on a checkerboard lattice at fillingν=2/3and we find that the unique interplay between smectic charge order and topological order gives rise to two novel quantum states. As the interaction strength increases, the system first transitions from a Fermi liquid (FL) into FQAH smectic (FQAHS) state, where the topological order coexists cooperatively with smectic charge order with enlarged ground-state degeneracy and interestingly, the Hall conductivity isσxy=ν=2/3, different from the band-folding or doping scenarios. Further increasing the interaction strength, the system undergoes another quantum phase transition and evolves into a polar smectic metal (PSM) state. This emergent PSM is an anisotropic non-Fermi liquid, whose interstripe tunneling is irrelevant while it is metallic inside each stripe. Different from the FQAHS and conventional smectic orders, this PSM spontaneously breaks the two-fold rotational symmetry, resulting in a nonzero electric dipole moment and ferroelectric order. In addition to the exotic ground states, large-scale numerical simulations are also used to study low-energy excitations and thermodynamic characteristics. We find that the onset temperature of the incompressible FQAHS state, which also coincides with the onset of non-polar smectic order, is dictated by the magneto-roton modes. Above this onset temperature, the PSM state exists at an intermediate-temperature regime. Although theT = 0 quantum phase transition between PSM and FQAHS is first order, the thermal FQAHS-PSM transition could be continuous. We expect the features of the exotic states and thermal phase transitions could be accessed in future experiments.

Thermodynamic Response and Neutral Excitations in Integer and Fractional Quantum Anomalous Hall States Emerging from Correlated Flat Bands.

Integer and fractional Chern insulators have been extensively explored in correlated flat band models. Recently, the prediction and experimental observation of fractional quantum anomalous Hall (FQAH) states with spontaneous time-reversal symmetry breaking have garnered attention. While the thermodynamics of integer quantum anomalous Hall (IQAH) states have been systematically studied, our theoretical knowledge on thermodynamic properties of FQAH states has been severely limited. Here, we delve into the general thermodynamic response and collective excitations of both IQAH and FQAH states within the paradigmatic flat Chern-band model with remote band considered. Our key findings include (i) in both ν=1 IQAH and ν=1/3 FQAH states, even without spin fluctuations, the charge-neutral collective excitations would lower the onset temperature of these topological states, to a value significantly smaller than the charge gap, due to band mixing and multiparticle scattering; (ii) by employing large-scale thermodynamic simulations in FQAH states in the presence of strong interband mixing between C=±1 bands, we find that the lowest collective excitations manifest as the zero-momentum excitons in the IQAH state, whereas in the FQAH state, they take the form of magnetorotons with finite momentum; (iii) the unique charge oscillations in FQAH states are exhibited with distinct experimental signatures, which we propose to detect in future experiments.

Amplitude Mode in Quantum Magnets via Dimensional Crossover.

We investigate the amplitude (Higgs) mode associated with longitudinal fluctuations of the order parameter at the continuous spontaneous symmetry breaking phase transition. In quantum magnets, due to the fast decay of the amplitude mode into low-energy Goldstone excitations, direct observation of this mode represents a challenging task. By focusing on a quasi-one-dimensional geometry, we circumvent the difficulty and investigate the amplitude mode in a system of weakly coupled spin chains with the help of quantum Monte Carlo simulations, stochastic analytic continuation, and a chain-mean field approach combined with a mapping to the field-theoretic sine-Gordon model. The amplitude mode is observed to emerge in the longitudinal spin susceptibility in the presence of a weak symmetry-breaking staggered field. A conventional measure of the amplitude mode in higher dimensions, the singlet bond mode, is found to appear at a lower than the amplitude mode frequency. We identify these two excitations with the second (first) breather of the sine-Gordon theory, correspondingly. In contrast to higher-dimensional systems, the amplitude and bond order fluctuations are found to carry significant spectral weight in the quasi-1D limit.

Diagnosis of Interaction-driven Topological Phase via Exact Diagonalization.

We propose a general scheme for diagnosing interaction-driven topological phases in the weak interaction regime using exact diagonalization (ED). The scheme comprises the analysis of eigenvalues of the point-group operators for the many-body eigenstates and the correlation functions for physical observables to extract the symmetries of the order parameters and the topological numbers of the underlying ground states at the thermodynamic limit from a relatively small size system afforded by ED. As a concrete example, we investigate the interaction effects on the half-filled spinless fermions on the checkerboard lattice with a quadratic band crossing point. Numerical results support the existence of a spontaneous quantum anomalous Hall phase purely driven by a nearest-neighbor weak repulsive interaction, separated from a nematic Mott insulator phase at strong repulsive interaction by a first-order phase transition.

Spin-degree manipulation for one-dimensional room-temperature ferromagnetism in a haldane system.

The intricate correlation between lattice geometry, topological behavior and charge degrees of freedom plays a key role in determining the physical and chemical properties of a quantum-magnetic system. Herein, we investigate the introduction of the unusual oxidation state as an alternative pathway to modulate the magnetic ground state in the well-known S = 1 Haldane system nickelate Y2BaNiO5 (YBNO). YBNO is topologically reduced to incorporate d9-Ni+ (S = 1/2) in the one-dimensional Haldane chain system. The random distribution of Ni+ for the first time results in the emergence of a one-dimensional ferromagnetic phase with a transition temperature far above room temperature. Theoretical calculations reveal that the antiferromagnetic interplay can evolve into ferromagnetic interactions with the presence of oxygen vacancies, which promotes the formation of ferromagnetic order within one-dimensional nickel chains. The unusual electronic instabilities in the nickel-based Haldane system may offer new possibilities towards unconventional physical and chemical properties from quantum interactions.

Three new mixed-alkali- and alkaline-earth-metal borates: from 1D chain to 2D layer to 3D framework.

Three new mixed-metal borates, K4Ba2[B14O20(OH)10]·3H2O (1), LiSr2[B10O16(OH)3] (2), and LiBa[B9O15] (3), have been made under hydro(solvo)thermal conditions and characterized by means of IR, UV-vis-near-IR, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1 is a 1D chain constructed from B14O21(OH)10(10-) cluster units, 2 is of a 2D layer with nine-membered-ring windows built up of B10O19(OH)3(9-) cluster units, while 3 exhibits a 3D framework with 12-membered-ring channels composed of B3O7 cluster units.

[Empirical analysis on lumbar disc herniation treated with "sinew-bone three needling technique" of Chinese medicine].

The paper presents professor WU Han-qing's experience in treatment of lumbar disc herniation (LDH) with "sinew-bone three needling technique" of Chinese medicine. Based on the theory of meridian sinew, the points are located by "three-pass method" in terms of the distribution of meridian sinew and syndrome/pattern differentiation. The cord-like muscles and adhesion are relieved by relaxing technique to work directly on the affected sites and alleviate the local compression to the nerve root. The needle technique is operated flexibly according to the affected regions involved, due to which, the needling sensation is increased while the safety ensured. As a result, the meridian qi is enhanced, the mind and qi circulation is regulated; and the clinical effect is improved.

Hypoxia-inducible factor-1 up-regulates the expression of Toll-like receptor 4 in pancreatic cancer cells under hypoxic conditions.

BACKGROUND & AIMS: Hypoxia is a common characteristic of solid tumors. Recent studies confirmed that Toll-like receptor 4 (TLR4) plays a significant role in cancer invasion and progression. In this study, the correlation between the expression of TLR4 and the change of the protein level of Hypoxia-inducible factor-1 alpha (HIF-1α) was studied. METHODS: We examined 84 human pancreatic cancer tissues for expression of HIF-1α and TLR4 proteins. Panc-1 cells were exposed to normoxia (20% O(2)) or hypoxia (<1% O(2)) or treated with CoCl(2). TLR4 protein was analyzed by flow cytometry and immunostaining. Growth studies were conducted on cells with the HIF-1α inhibition isolated from stable transfected cell lines. Finally, TLR4 protein was detected by immunohistochemistry in vivo tumors. RESULTS: There was a positive correlation between TLR4 and HIF-1α protein in pancreatic cancer tissues. Hypoxic stress induced TLR4 mRNA and protein expression in Panc-1 cells. Cells transfected with HIF-1α siRNA showed attenuation of hypoxia stress-induced TLR4 expression. In vivo growth decreased in response to TLR4 and HIF-1α inhibiton. Transient HIF-1α siRNA treatment could effectively curb tumor growth in vivo. CONCLUSION: These results suggest that TLR4 expression in pancreatic cancer cells is up-regulated via HIF-1α in response to hypoxic stress and underscore the crucial role of HIF-1α-induced TLR4 in tumor growth.

[WU Han-qing's theory and clinical application of "three regions, nine needles and twelve methods"].

The paper introduces the theory and the clinical application of "three regions, nine needles and twelve methods" summarized by professor WU Han-qing. On the basis of traditional nine needles and in association with taiji longguan needling technique handed down from family generations, WU Han-qing innovated "three regions, nine needles and twelve methods". According to the treating location and anatomical structure, the needling techniques are classified in terms of three regions, i.e. the needling technique of cutaneous region, that of sinew region and that of periosteum region. Nine kinds of needle devices are developed, including two categories, i.e. miniature sinew-bone needle and grand sinew-bone needle. Based on the three-region needling techniques, 12 acupuncture methods are summarized for different areas and layers of diseases. This acupuncture technique is applicable for the treatment of chronic pain such as injury of sinews, pain in the neck, shoulder, lumbar region and leg and sequela of apoplexy.

[Experience in treatment of cervical spondylotic radiculopathy by relaxing the sinew of hand three yang meridians with the tendon-bone needling therapy of Chinese medicine].

The clinical experience of professor WU Han-qing in treatment of cervical spondylotic radiculopathy (CSR) with the tendon-bone needling therapy of Chinese medicine is introduced. Professor WU believes that the pathogenesis of CSR is the damage on the neck and the sinew of hand three yang meridians, the formation of clustered nodules, obstruction in meridians and the stagnation of qi and blood. In treatment, the tendon-bone needling therapy is mainly adopted to relaxing clustered nodules and the sinew of hand three yang meridians and promoting qi and blood circulation. Regarding the acupoint selection, the "three-yangguan localization method" is used. The three hand-yangguan points and the three wrist-yangguan points are selected. The knotted points corresponding to the affected transverse processes of cervical vertebra are selected as well. Meanwhile, the adjuvant treatment points are selected on the base of the principle as "selecting the points along the affected meridian sinew". During treatment, according to needling sites and layers, the different needling techniques are optioned flexibly. Besides, the attentive experience in needling sensation in physician and the interaction between physician and patient are emphasized so as to improve the safety of treatment.

Identification of magnetic interactions and high-field quantum spin liquid in α-RuCl3.

The frustrated magnet α-RuCl3 constitutes a fascinating quantum material platform that harbors the intriguing Kitaev physics. However, a consensus on its intricate spin interactions and field-induced quantum phases has not been reached yet. Here we exploit multiple state-of-the-art many-body methods and determine the microscopic spin model that quantitatively explains major observations in α-RuCl3, including the zigzag order, double-peak specific heat, magnetic anisotropy, and the characteristic M-star dynamical spin structure, etc. According to our model simulations, the in-plane field drives the system into the polarized phase at about 7 T and a thermal fractionalization occurs at finite temperature, reconciling observations in different experiments. Under out-of-plane fields, the zigzag order is suppressed at 35 T, above which, and below a polarization field of 100 T level, there emerges a field-induced quantum spin liquid. The fractional entropy and algebraic low-temperature specific heat unveil the nature of a gapless spin liquid, which can be explored in high-field measurements on α-RuCl3.

Novel dual-functional fluorescent sensors based on bis(5,6-dimethylbenzimidazole) derivatives for distinguishing of Ag+ and Fe3+ in semi-aqueous medium.

Three novel bisbenzimidazole derivatives have been synthesized and developed as dual-functional fluorescent sensors for the rapid and highly selective detection of Ag+ and Fe3+ ions in semi-aqueous medium with distinct spectral response for the first time. The absorption intensity is drastically decreased after the addition of Ag+. Contrarily, it is markedly increased upon the addition of Fe3+. And there is a good linear relation at low concentration of both Ag+ and Fe3+, which provides a quantitative method for their detection. Similarly, the sensors show a distinct fluorescence response towards Ag+ and Fe3+ with a different fluorescence color change under UV light. In addition, no significant changes and interference can be observed with other metal ions. The sensing mechanism studies confirm that the N atom in CN of benzimidazole ring of sensor 4a may bind with Ag+ or Fe3+ ion to form metal complex. And there is only a static quenching process for the 4-Ag+ complex system, but both dynamic and static quenching processes occur in the 4-Fe3+ complex system. Moreover, sensors 4 can steadily work in solution with a wide range of pH 4-13 and rapidly respond to Ag+ and Fe3+ with a response time of 10 s. Finally, the sensors have been successfully applied to the visual detection of Ag+ and Fe3+ not only in solution, but also in test paper.

Quick construction of a C-N bond from arylsulfonyl hydrazides and Csp2-X compounds promoted by DMAP at room temperature.

An efficient approach for C-N bond construction by the coupling reaction of arylsulfonyl hydrazides and Csp2-X compounds is described for the first time with good yields at room temperature. The reaction promoted by the simple base DMAP displays excellent regioselectivity as well as high functional group tolerance with 41 examples. Even for inactive Csp2-Cl compounds, the metal-free transformation also affords a satisfactory yield after prolonging the reaction time, which is comparable to that of the corresponding Csp2-Br compound. The good effect of DMAP and its action mechanism are confirmed by the competitive experiments of reactivity between Cl-substituted and Br-substituted substrates and the single-crystal X-ray analysis of the key intermediate quaternary ammonium salt. Importantly, the application of this method for a gram-scale (even over 10 g) preparation can be accomplished.

Bis-2(5H)-furanone derivatives as new anticancer agents: Design, synthesis, biological evaluation, and mechanism studies.

New bis-2(5H)-furanone derivatives containing a benzidine core were synthesized via a one-step transition-metal-free reaction of benzidine with 5-substituted 3,4-dihalo-2(5H)-furanones. Their antitumor activities against various tumor cells have been evaluated by MTT assay. Among them, compound 4e exhibits significant inhibitory activity against C6 glioma cells with an IC50 value of 12.1 µm and low toxicity toward HaCaT human normal cells. Studies on the antitumor mechanism reveal that cell cycle arrest at S-phase in C6 cells is induced by compound 4e. Furthermore, investigations with electronic, fluorescence emission and circular dichroism spectra show that compound 4e can significantly interact with C6-DNA. These data indicate that DNA may be one of the potential targets for bis-2(5H)-furanone derivatives as anticancer drugs.

Synthesis and biological evaluation of 4-biphenylamino-5-halo-2(5H)-furanones as potential anticancer agents.

An efficient route without metal catalyst has been developed for synthesis of 4-biphenylamino-5-halo-2(5H)-furanones. The antitumor activities against various tumor cells of all the compounds have been evaluated by MTT assay. Among them, the compound 3j exhibits significant inhibitory activity against MCF-7 human breast cancer cells with an IC50 value of 11.8 µM and low toxicity toward HaCaT human normal cells. The mechanism studies confirm that 3j can induce cell cycle arrest at G2/M phase in MCF-7 cells. Compared with compound 3e, 3j has stronger binding affinity to c-myc G-quadruplex (G4) DNA via π-π stacking and H-bonding interactions. Western blot analysis also further confirms that compound 3j can down-regulate the expression of c-myc in MCF-7 cells.

Overexpression of membrane-type 2 matrix metalloproteinase induced by hypoxia-inducible factor-1α in pancreatic cancer: Implications for tumor progression and prognosis.

Membrane-type 2 matrix metalloproteinase (MT2-MMP) has been identified as a powerful modulator of the pericellular environment that promotes tumor invasion and metastasis. In this study, we investigated the association of MT2-MMP and hypoxia-inducible factor-1α (HIF-1α) expression in pancreatic cancer with regard to their clinical prognostic significance. Of the tissue specimens obtained from the 78 patients included in this study, 46 (59%) were found to be positive for MT2-MMP immunostaining and MT2-MMP expression was colocalized with HIF-1α in pancreatic cancer. Using the Spearman's rank analysis, the protein and mRNA expression level of MT2-MMP was found to be significantly correlated with HIF-1α and CD34-microvascular density in pancreatic cancer. Furthermore, the expression of MT2-MMP in response to hypoxia was increased in a time-dependent manner and the promoter luciferase reporter revealed upregulation of MT2-MMP expression induced by HIF-1α in pancreatic cancer cells. Moreover, the Cox regression model indicated that MT2-MMP was an independent prognostic factor in patients with pancreatic cancer. Our results demonstrated that the overexpression of MT2-MMP was induced by HIF-1α in response to hypoxia and was an independent prognostic factor for pancreatic cancer progression.

Effects of CPG ODN on biological behavior of PANC-1 and expression of TLR9 in pancreatic cancer.

AIM: To determine the expression of toll-like receptor 9 (TLR9) in pancreatic tumor and the effects of cytosine phosphate-guanosine oligodeoxynucleotides 2216 (CPG ODN2216) on biological behavior of pancreatic carcinoma cell line PANC-1 and explore their clinical significance. METHODS: The immunohistochemistry and Western blot were used to determine the expression of TLR9 protein in pancreatic cancer tissues, and immunofluorescence staining was performed to detect the TLR9 protein expression in pancreatic carcinoma cell line PANC-1. To assess the effects of CPG ODN2216 on the invasive property of Panc-1 cells, in vitro cell adhesion, wound-healing scrape, and invasion and cell colony formation were evaluated. RESULTS: TLR9 was highly expressed in pancreatic cancer tissues and PANC-1 cells. The percentage of positive cells expressing TLR9 protein in human pancreatic tissues, paracancerous tissues and normal tissues were 73.3%, 33.3% and 20.0%, respectively, and the protein expression level of TLR9 was gradually descending (P < 0.05). In vitro tests in wound-healing scrape, cell adhesion, colony formation and matrigel invasion showed that the adhesion and motility of PANC-1 cells in CPG ODN 2216 treatment group were significantly lower than in the control group (P < 0.05). The cell growth assay showed that the proliferative ability of PANC-1 cells in treatment group was significantly decreased and CPG ODN2216 had an inhibitive effect in the growth of Panc-1 cells in a dose and time-dependent manner (P < 0.05). CONCLUSION: The gene of TLR9 is correlated with the invasive and metastatic potential of human pancreatic carcinoma, and CPG ODN2216 induces the inhibition of migration and invasion of Panc-1 cells.

[Efficacy of water knife needle release combined with bone peptide injection for heel pain].

OBJECTIVE: To evaluate the efficacy of water knife needle release combined with bone peptide injection in the management of heel pain. METHODS: Thirty-five patients with unilateral heel pain were treated with water knife needle release and bone peptide injection under local anesthesia. The deep tissue with the tenderness was released in the operation, and the result was evaluated 1 week after the surgery to decide whether to conduct another surgery. No more than 3 treatment sessions were administered. The efficacy was evaluated according to nimodipine method by the principles of Chinese clinical drug guidance, and the complications of the surgery were observed. RESULTS: Six months after the surgery, 28 cases had excellent results, 3 had good outcomes, 2 showed improvement, and 2 failed to respond favorably, with a rate of good and excellent result of 94.2%. No adverse side effect was recorded in the follow up of the patients. CONCLUSION: Water needle knife release combined with bone peptide injection can produce a good result in the treatment of heel pain.