Objectives: This study aimed to determine the role and mechanism underlying migration and invasion inhibitory protein (MIIP) modulation in M2 macrophages within the tumor microenvironment and the potential of targeting the MIIP– stimulator of interferon genes (STING) pathway in colorectal cancer (CRC) therapy. Methods: MIIP expression was analyzed for associations with the STING pathway and M2 macrophage infiltration using public datasets and clinical CRC samples. CRC cells were genetically modified using lentiviral vectors to overexpress or silence MIIP and STING. The interactions of genetically modified CRC cells with macrophages were studied in co-culture systems. Techniques, including immunofluorescence staining, RT-qPCR, western blot, ELISA, flow cytometry, and Transwell migration and invasion assays, were used to evaluate the crosstalk between CRC cells and macrophages. An orthotopic mouse CRC model was developed to study the effects of MIIP on M2 macrophage polarization and tumor metastasis through the STING–NFκB2–IL10 axis. The therapeutic significance of a STING antagonist was also assessed in vivo. Results: Analyses of The Cancer Genome Atlas (TCGA) cohort and our CRC cohort revealed low MIIP expression is associated with STING pathway activation, increased M2 macrophage infiltration, and poor clinical outcomes. The results of functional experiments demonstrated that MIIP inhibits IL10 production via the STING–TRAF3–NFκB2 axis in CRC cells, suppressing M2 macrophage polarization in co-culture systems. Conversely, M2 macrophages promoted CRC cell migration and invasion in an IL10-dependent manner. In vitro and in vivo studies confirmed that the MIIP-mediated feedback loop between CRC cells and macrophages depends on the STING–NFκB2–IL10 axis. Furthermore, inhibition of STING expression in a mouse model reduced M2 macrophage polarization and tumor metastasis. Conclusions: This study established MIIP as a crucial regulator of macrophage polarization in the CRC tumor microenvironment, providing new insights into the role in suppressing CRC progression and immune–tumor crosstalk. These findings highlight the potential of targeting the STING pathway as a therapeutic strategy for CRC patients who respond poorly to immune checkpoint inhibitors.
Abstract Superconductivity is observed in rhombohedral trilayer graphene in a narrow regime between the flavour-symmetric state and the symmetry breaking phase, which cannot be described by the conventional Bardeen-Cooper-Schrieffer theory. The measured coherence length, for instance, is roughly two orders of magnitude shorter than the value predicted by the Bardeen-Cooper-Schrieffer relation based on the large fermi velocity and an extremely low charge carrier density of the flavour-symmetric phase. To resolve the discrepancies, we propose that the rhombohedral trilayer graphene superconducting phase arises from the pairing of quasiparticles of the adjacent inter-valley coherent state. We illustrate the superconducting phenomenology using gapped Dirac cones with the chemical potential μ close to the valence band’s edge. Our findings indicate that the transition temperature T c obeys $${T}_{c}\propto {\epsilon }_{D}\exp (-2/{\rho }_{\rm{qp}}U)$$ T c ∝ ϵ D exp ( − 2 / ρ qp U ) with the density of states ρ qp of intervalley coherent state quasiparticles, which is much suppressed compared to predictions from the Bardeen-Cooper-Schrieffer theory. The coherence length ξ we predict behaves according to $$\xi \sim v/\sqrt{\mu {T}_{c}}$$ ξ ~ v / μ T c with v being the velocity of Dirac cone. Applying our assumption to a microscopic model, our predictions align well with experimental data and effectively capture key measurable quantities such as the transition temperature T c and the coherence length ξ `without parameter fine-tuning.
Objectives This study aimed to determine the role and mechanism underlying migration and invasion inhibitory protein (MIIP) modulation in M2 macrophages within the tumor microenvironment and the potential of targeting the MIIPu2013 stimulator of interferon genes (STING) pathway in colorectal cancer (CRC) therapy. Methods MIIP expression was analyzed for associations with the STING pathway and M2 macrophage infiltration using public datasets and clinical CRC samples. CRC cells were genetically modified using lentiviral vectors to overexpress or silence MIIP and STING. The interactions of genetically modified CRC cells with macrophages were studied in co-culture systems. Techniques, including immunofluorescence staining, RT-qPCR, western blot, ELISA, flow cytometry, and Transwell migration and invasion assays, were used to evaluate the crosstalk between CRC cells and macrophages. An orthotopic mouse CRC model was developed to study the effects of MIIP on M2 macrophage polarization and tumor metastasis through the STINGu2013NFu03BAB2u2013IL10 axis. The therapeutic significance of a STING antagonist was also assessed in vivo. Results Analyses of The Cancer Genome Atlas (TCGA) cohort and our CRC cohort revealed low MIIP expression is associated with STING pathway activation, increased M2 macrophage infiltration, and poor clinical outcomes. The results of functional experiments demonstrated that MIIP inhibits IL10 production via the STINGu2013TRAF3u2013NFu03BAB2 axis in CRC cells, suppressing M2 macrophage polarization in co-culture systems. Conversely, M2 macrophages promoted CRC cell migration and invasion in an IL10-dependent manner. In vitro and in vivo studies confirmed that the MIIP-mediated feedback loop between CRC cells and macrophages depends on the STINGu2013NFu03BAB2u2013IL10 axis. Furthermore, inhibition of STING expression in a mouse model reduced M2 macrophage polarization and tumor metastasis. Conclusions This study established MIIP as a crucial regulator of macrophage polarization in the CRC tumor microenvironment, providing new insights into the role in suppressing CRC progression and immuneu2013tumor crosstalk. These findings highlight the potential of targeting the STING pathway as a therapeutic strategy for CRC patients who respond poorly to immune checkpoint inhibitors.
Quantum gravity-gradient sensing technology exhibits unique advantages and significant application potential in geophysical research and practical scenarios. We present a free-fall vertical gravity gradiometer based on cold-atom interferometry. Phase-difference extraction employs an elliptical-fitting method that is simple to implement and responds rapidly to gravitational variations. A detailed analysis is conducted on the noise associated with this method and corresponding optimizations are carried out. The device achieves a performance with a sensitivity of 52.9 E/root Hz and a stability better than 0.5 E over 7 & times; 104 s (1 E = 1 & times; 10-9 s-2). Based on this performance, we initially completed the application simulation of resource exploration scenarios in the laboratory and evaluated its accuracy and sensitivity in the exploration field. This research work provides support for future geophysical research and applications.
The Kibble-Zurek (KZ) mechanism renders a theoretical framework for elucidating the formation of topological defects across continuous phase transitions. Nevertheless, it is not immediately clear whether the KZ mechanism applies to topological phase transitions. The direct experimental study for such a topic is hindered by quenching a certain parameter over orders of magnitude in topological materials. Instead, we investigate the KZ behavior across topological transitions of a Chern band in two-dimensional (2D) optical Raman lattices with quantum gases. Defined as the defects, excitation density is reconstructed via measuring the spin wave functions, with which the power-law scaling of total excitation density is extracted and such scaling could be interpreted within the KZ framework. Our work has heralded the commencement of experimentally exploring the KZ mechanism of the topological phase transitions.
The Chern-Simons (CS) invariant is a fundamental topological invariant describing the topological invariance of three-dimensional (3D) space based on the Chern-Simons field theory. To date, direct measurement of the CS invariant in a physical system remains elusive. Here, the CS invariant is experimentally measured by quenching a 2D optical Raman lattice with 1/2 spin in ultracold atoms. With a recently developed Bloch state tomography, we measure the expectation values of three Pauli matrices in 2D quasimomentum space plus 1D time [(2 + 1)D], and then respectively extract the Berry curvature and the corresponding Berry connection. By integrating the product of these two quantities, we obtain the CS invariants near f1 and 0, which are consistent with theoretical predictions. We also observe transitions among these values, which indicates the change of the topology of the quantum state in (2 + 1)D quantum dynamics.
In this work, we consider superconductor/flat band material/superconductor (S/FB/S) Josephs on junctions (JJs) where the flat band material possesses isolated flat bands with exactly zero Fermi velocity. Contrary to conventional S/N/S JJs where the critical Josephson current vanishes when the Fermi velocity goes to zero, we show in this work that the critical current in the S/FB/S junction is controlled by the quantum metric length ξ_{QM} of the flat bands. Microscopically, when ξ_{QM} of the flat band is long enough, the interface bound states originally localized at the two S/FB, FB/S interfaces can penetrate deeply into the flat band material and hybridize to form Andreev bound states (ABSs). These ABSs are able to carry long range and sizable supercurrents. Importantly, ξ_{QM} also controls how far the proximity effect can penetrate into the flat band material. This stands in sharp contrast to the de Gennes' theory for S/N junctions which predicts that the proximity effect is expected to be zero when the Fermi velocity of the normal metal is zero. We further suggest that the S/FB/S junctions would give rise to a new type of resonant Josephson transistor which can carry a sizable and highly gate-tunable supercurrent.
The atom gravimeter, based on the principle of matter-wave interferometry, represents a new generation of high-precision gravity measurement instruments with significant application potential. We have successfully developed a high-precision atom gravimeter named USTC-AG12. To comprehensively evaluate its environmental adaptability and performance in long-term measurements, while effectively suppressing vibration noise and increasing system stability, we transported the device to a mountain 800 km away and conducted continuous gravity measurements using advanced vibration postcompensation techniques. The experimental results demonstrate that the atom gravimeter achieved stable operation for more than 150 days, with a measurement sensitivity of 18.6 mu Gal/root Hz and stability of 0.6 mu Gal at 1000 s. Moreover, comparative observations with a superconducting gravimeter showed excellent consistency between the two instruments: the long-term measurements exhibited almost no drift. Additionally, we used the continuous observation data from the cold-atom gravimeter to thoroughly validate the reliability of gravity data in seismic analysis and research. Through comparative analysis with seismometer recordings, the two instruments demonstrated high consistency in extracting seismic surface wave dispersion velocities, confirming the application value of atom gravimeters in the field of seismic research.
Time-varying gravity field survey is one of the important methods for seismic risk assessment. To obtain accurate timevarying gravity data, it is essential to establish a gravity reference, which can be achieved using absolute gravimeters. Atom gravimeters, as a recently emerging type of absolute gravimeter, have not yet been practically validated for their reliability in mobile gravity surveys. To study and evaluate the operational status and performance metrics of the A-Grav atom gravimeter under complex field conditions, the University of Science and Technology of China, Hefei National Laboratory, and the Anhui Earthquake Agency conducted a joint observation experiment using an atom gravimeter (AGrav) and relative gravimeters (CG-6) within the North China Seismic Gravity Monitoring Network. The experiment yielded the following results: 1) The standard deviations for mobile observations of the atom gravimeter is 2.1 μGal; 2)The mean differences in point values and segment differences between the atom gravimeter and the relative gravimeter at the same locations is 5.8(17.1) μGal and 4.4(11.0) μGal, respectively, with point value differences of less than 2.0 μGal compared to the FG5X absolute gravimeter at the same location; 3) The results of hybrid gravity adjustment based on absolute gravity control and the point value precision at each measurement point, with an average point value precision of 3.6 μGal. The results indicate that the A-Grav atom gravimeter has observation accuracy and precision comparable to the FG5X absolute gravimeter, demonstrating good stability and reliability in field mobile measurements, and can meet the requirements for seismic gravity monitoring. This work provides a technical reference for the practical application of atom gravimeters in control measurements and time-varying gravity monitoring for earthquakes.
The study of the gauge field is an everlasting topic in modern physics. Spin-orbit coupling is a powerful tool in ultracold atomic systems, resulting in an artificial gauge field that can be easily manipulated and observed in a tabletop environment. Combining optical Raman lattices and atom-atom interactions, the artificial gauge field can be made density dependent. In this work we propose a straightforward way to engineer a one-dimensional density-dependent gauge field in a Bose-Hubbard model in spin-orbit-coupled Raman lattices. We study the model from two perspectives: few-body quantum-walk dynamics and the many-body ground state. From the first perspective, we show that large spin-flipped tunneling can lead to a deep two-body bound state. From the second perspective, mean-field and density-matrix renormalization-group calculations consistently reveal three different phases, i.e., the Mott insulator phase, the superfluid phase, and the magnetic superfluid phase. Finally, we discuss the experimental protocol with Raman lattices based on existing experimental platforms.
Mounting evidence has demonstrated the genetic association of ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) gene polymorphisms with bronchial asthma and a diverse set of inflammatory disorders. However, its role in type I interferon (type I IFN) signaling remains poorly defined. Herein, we report that ORMDL3 is a negative modulator of the type I IFN signaling by interacting with mitochondrial antiviral signaling protein (MAVS) and subsequently promoting the proteasome-mediated degradation of retinoic acid-inducible gene I (RIG-I). Immunoprecipitation coupled with mass spectrometry (IP-MS) assays uncovered that ORMDL3 binds to ubiquitin-specific protease 10 (USP10), which forms a complex with and stabilizes RIG-I through decreasing its K48-linked ubiquitination. ORMDL3 thus disrupts the interaction between USP10 and RIG-I, thereby promoting RIG-I degradation. Additionally, subcutaneous syngeneic tumor models in C57BL/6 mice revealed that inhibition of ORMDL3 enhances anti-tumor efficacy by augmenting the proportion of cytotoxic CD8 positive T cells and IFN production in the tumor microenvironment (TME). Collectively, our findings reveal the pivotal roles of ORMDL3 in maintaining antiviral innate immune responses and anti-tumor immunity.
The coherence length ξ is the fundamental length scale of superconductors which governs the sizes of Cooper pairs, vortices, Andreev bound states, and more. In BCS theory, the coherence length is ξBCS = ℏvF/Δ, where vF is the Fermi velocity and Δ is the pairing gap. It is clear that increasing Δ will shorten ξBCS. In this work, we show that the quantum metric, which is the real part of the quantum geometric tensor, gives rise to an anomalous contribution to the coherence length. Specifically, $$\xi =\sqrt{{\xi }_{{{{\rm{BCS}}}}}^{2}+{\ell }_{{{{\rm{qm}}}}}^{2}}$$ for a superconductor where ℓqm is the quantum metric contribution. In the flat-band limit, ξ does not vanish but is bound below by ℓqm. We demonstrate that under the uniform pairing condition, ℓqm is controlled by the quantum metric of minimal trace in the flat-band limit. Physically, the Cooper pair size of a superconductor cannot be squeezed down to a size smaller than ℓqm which is a fundamental length scale determined by the quantum geometry of the wave functions. Lastly, we compute the quantum metric contributions for the family of superconducting moiré graphene materials, demonstrating the significant role played by quantum metric effects in these narrow-band superconductors. The coherence length is a key parameter of a superconductor and can usually be determined using BCS theory; however recent experiments on twisted bilayer graphene have shown a large deviation from the predicted values. Here, the authors show how quantum geometry contributes to the coherence length and how it could explain recent observations in flat band systems.
The Kibble-Zurek (KZ) mechanism describes the scaling behavior when driving a system across a continuous symmetry-breaking transition. Previous studies have shown that the KZ-like scaling behavior also lies in the topological transitions in the Qi-Wu-Zhang model (2D) and the Su-Schrieffer-Heeger model (1D), although symmetry breaking does not exist in these systems. Both models with linear band crossings yield nu similar or equal to 1 and z similar or equal to 1. A natural question is whether different critical exponents can emerge in topological transitions beyond the linear band crossings. In this paper, we look into the KZ behavior in a topological 2D checkerboard lattice with a quadratic band crossing. We investigate from dual perspectives: momentum distribution of the Berry curvature in clean systems for simplicity, and real-space analysis of domain-like local Chern marker configurations in disordered systems, which is a more intuitive analog to conventional KZ description. In equilibrium, we find the correlation length diverges at the transition with a power nu similar or equal to 1/2. Then, by slowly quenching the system across the topological phase transition, we find that the freeze-out time tf and the unfrozen length scale xi(tf) both satisfy the KZ scaling, verifying z similar or equal to 2. We subsequently explore KZ behavior in topological phase transitions with other higher-order band crossings and find the relationship between the critical exponents and the order. Our results extend the understanding of the KZ mechanism and nonequilibrium topological phase transitions.
This topical review article reports rapid progress on the generalization and application of entanglement in non-Hermitian free-fermion quantum systems.We begin by examining the realization of non-Hermitian quantum systems through the Lindblad master equation,alongside a review of typical non-Hermitian free-fermion systems that exhibit unique features.A pedagogical discussion is provided on the relationship between entanglement quantities and the correlation matrix in Hermitian systems.Building on this foundation,we focus on how entan-glement concepts are extended to non-Hermitian systems from their Hermitian free-fermion counterparts,with a review of the general properties that emerge.Finally,we highlight various concrete studies,demonstrating that entanglement entropy remains a powerful diagnostic tool for characterizing non-Hermitian physics.The entan-glement spectrum also reflects the topological characteristics of non-Hermitian topological systems,while unique non-Hermitian entanglement behaviors are also discussed.The review is concluded with several future directions.Through this review,we hope to provide a useful guide for researchers who are interested in entanglement in non-Hermitian quantum systems.
Our previous understanding of transport in disordered system depends on the assumption that there is a well-defined Fermi velocity. The Fermi velocity determines important length scales in the system such as the diffusion length and localization length. However, nearly flat band materials with vanishing Fermi velocity, it is uncertain how to understand the disorder effects and what quantities determine the characteristic length scales in the system. In the clean limit, it is expected that the bulk transport is absent. In this work, we demonstrate, with a diamond lattice, that disorder can induce diffusion transport in a flat-band system with finite quantum metric. As disorder increases, the bulk transmission channels are activated, and the conductance reaches a maximum before decays inversely with disorder strength. Importantly, via the calculation of the wave-packet dynamics numerically, we show that the quantum metric determines the diffusion length of the system. Analytically, we show that the interplay between the disorder and quantum geometry gives rise to an effective Fermi velocity, as captured by the self-consistent Born approximation. The diffusion coefficient is identified from the Bethe-Salpeter equation under the ladder approximation. Our results reveal a disorder-driven delocalization mechanism in flat-band systems with finite quantum metric which cannot be understood by well-established theories of quantum diffusion. Our theory is important for understanding the disorder effects and transport properties of flat band materials such as twisted bilayer graphene which are current under intense investigation.
Recent experimental study unveiled highly unconventional phenomena in the superconducting twisted bilayer graphene (TBG) with ultra flat bands, which cannot be described by the conventional BCS theory. For example, given the small Fermi velocity of the flat bands, the superconducting coherence length predicted by BCS theory is more than 20 times shorter than the measured values. A new theory is needed to understand many of the unconventional properties of flat band superconductors. In this work, we establish a Ginzburg-Landau (GL) theory from a microscopic flat band Hamiltonian. The GL theory shows how the properties of the physical quantities such as the critical temperature, the superconducting coherence length, the upper critical field and the superfluid density are governed by the quantum metric of the Bloch states. One key conclusion is that the superconducting coherence length is not determined by the Fermi velocity but by the size of the optimally localized Wannier functions which is limited by quantum metric. Applying the theory to TBG, we calculated the superconducting coherence length and the upper critical fields. The results match the experimental ones well without fine tuning of parameters. The established GL theory provides a new and general theoretical framework for understanding flat band superconductors with quantum metric.
The two-dimensional (2D) material-based thermal switch is attracting attention due to its novel applications, such as energy conversion and thermal management, in nanoscale devices. In this paper, we observed that the reversible 2H–1T′ phase transition in MoTe2 is associated with about a fourfold/tenfold change in thermal conductivity along the X/Y direction by using first-principles calculations. This phenomenon can be profoundly understood by comparing the Mo–Te bonding strength between the two phases. The 2H-MoTe2 has one stronger bonding type, while 1T′-MoTe2 has three weaker types of bonds, suggesting bonding inhomogeneity in 1T′-MoTe2. Meanwhile, the bonding inhomogeneity can induce more scattering of vibration modes. The weaker bonding indicates a softer structure, resulting in lower phonon group velocity, a shorter phonon relaxation lifetime and larger Grüneisen constants. The impact caused by the 2H to 1T′ phase transition in MoTe2 hinders the propagation of phonons, thereby reducing thermal conductivity. Our study describes the possibility for the provision of the MoTe2-based controllable and reversible thermal switch device.
In Hilbert space, the geometry of the quantum state is identified by the quantum geometric tensor (QGT), whose imaginary part is the Berry curvature and whose real part is the quantum metric tensor. Here, we experimentally realize a complete Bloch-state tomography to directly measure the eigenfunction of an optical Raman lattice for ultracold atoms. Through the measured eigenfunction, the distribution of the complete QGT in the Brillouin zone is reconstructed, with which the topological invariants are extracted by the Berry curvature and the distances of quantum states in momentum space are measured by the quantum metric tensor. Furthermore, we experimentally test a predicted inequality between the Berry curvature and the quantum metric tensor, which reveals a deep connection between the topology and geometry.
A precise and convenient sensor was constructed to identify pathogens in household refrigerators (4 °C, RH = 55%) by integrating a volatile organic compound fingerprint-responsive gel-based colorimetric sensor array and a neural network. The platform is expected to be extended to the intelligent food packaging field and has promise for point-of-need monitoring of pathogens.