Thermodynamic evidence of fractional Chern insulator in moiré MoTe2.

Chern insulators, which are the lattice analogues of the quantum Hall states, can potentially manifest high-temperature topological orders at zero magnetic field to enable next-generation topological quantum devices1-3. Until now, integer Chern insulators have been experimentally demonstrated in several systems at zero magnetic field3-8, whereas fractional Chern insulators have been reported in only graphene-based systems under a finite magnetic field9,10. The emergence of semiconductor moiré materials11, which support tunable topological flat bands12,13, provides an opportunity to realize fractional Chern insulators13-16. Here we report thermodynamic evidence of both integer and fractional Chern insulators at zero magnetic field in small-angle twisted bilayer MoTe2 by combining the local electronic compressibility and magneto-optical measurements. At hole filling factor ν = 1 and 2/3, the system is incompressible and spontaneously breaks time-reversal symmetry. We show that they are integer and fractional Chern insulators, respectively, from the dispersion of the state in the filling factor with an applied magnetic field. We further demonstrate electric-field-tuned topological phase transitions involving the Chern insulators. Our findings pave the way for the demonstration of quantized fractional Hall conductance and anyonic excitation and braiding17 in semiconductor moiré materials.

Continuous Mott transition in semiconductor moiré superlattices.

The evolution of a Landau Fermi liquid into a non-magnetic Mott insulator with increasing electronic interactions is one of the most puzzling quantum phase transitions in physics1-6. The vicinity of the transition is believed to host exotic states of matter such as quantum spin liquids4-7, exciton condensates8 and unconventional superconductivity1. Semiconductor moiré materials realize a highly controllable Hubbard model simulator on a triangular lattice9-22, providing a unique opportunity to drive a metal-insulator transition (MIT) via continuous tuning of the electronic interactions. Here, by electrically tuning the effective interaction strength in MoTe2/WSe2 moiré superlattices, we observe a continuous MIT at a fixed filling of one electron per unit cell. The existence of quantum criticality is supported by the scaling collapse of the resistance, a continuously vanishing charge gap as the critical point is approached from the insulating side, and a diverging quasiparticle effective mass from the metallic side. We also observe a smooth evolution of the magnetic susceptibility across the MIT and no evidence of long-range magnetic order down to ~5% of the Curie-Weiss temperature. This signals an abundance of low-energy spinful excitations on the insulating side that is further corroborated by the Pomeranchuk effect observed on the metallic side. Our results are consistent with the universal critical theory of a continuous Mott transition in two dimensions4,23.

Remote imprinting of moiré lattices.

Two-dimensional moiré materials are formed by overlaying two layered crystals with small differences in orientation or/and lattice constant, where their direct coupling generates moiré potentials. Moiré materials have emerged as a platform for the discovery of new physics and device concepts, but while moiré materials are highly tunable, once formed, moiré lattices cannot be easily altered. Here we demonstrate the electrostatic imprinting of moiré lattices onto a target monolayer semiconductor. The moiré potential-created by a lattice of electrons that is supported by a Mott insulator state in a remote MoSe2/WS2 moiré bilayer-imprints a moiré potential that generates flat bands and correlated insulating states in the target monolayer and can be turned on/off by gate tuning the doping density of the moiré bilayer. Additionally, we studied the interplay between the electrostatic and structural relaxation contributions to moiré imprinting. Our results demonstrate a pathway towards gate control of moiré lattices.

Air-Stable Na3.5C6O6 as a Sodium Compensation Additive in Cathode of Na-Ion Batteries.

Sodium-ion battery (SIB) is a candidate for the stationary energy storage systems because of the low cost and high abundance of sodium. However, the energy density and lifespan of SIBs suffer severely from the irreversible consumption of the Na-ions for the formation of the solid electrolyte interphase (SEI) layer and other side reactions on the electrodes. Here, Na3.5C6O6 is proposed as an air-stable high-efficiency sacrificial additive in the cathode to compensate for the lost sodium. It is characteristic of low desodiation (oxidation) potential (3.4-3.6 V vs. Na+/Na) and high irreversible desodiation capacity (theoretically 378 mAh g-1). The feasibility of using Na3.5C6O6 as a sodium compensation additive is verified with the improved electrochemical performances of a Na2/3Ni1/3Mn1/3Ti1/3O2ǀǀhard carbon cells and cells using other cathode materials. In addition, the structure of Na3.5C6O6 and its desodiation path are also clarified on the basis of comprehensive physical characterizations and the density functional theory (DFT) calculations. This additive decomposes completely to supply abundant Na ions during the initial charge without leaving any electrochemically inert species in the cathode. Its decomposition product C6O6 enters the carbonate electrolyte without bringing any detectable negative effects. These findings open a new avenue for elevating the energy density and/or prolonging the lifetime of the high-energy-density secondary batteries.

Method for GPU-based spectral data cube reconstruction of integral field snapshot imaging spectrometers.

In this paper, the principles of spectral data cube reconstruction based on an integral field snapshot imaging spectrometer and GPU-based acceleration are presented. The primary focus is on improving the reconstruction algorithm using GPU parallel computing technology to enhance the computational efficiency for real-time applications. And the computational tasks of the spectral reconstruction algorithm were transferred to the GPU through program parallelization and memory optimization, resulting in significant performance gains. Experimental results indicate that the average processing time of the GPU-based parallel algorithm is approximately 29.43 ms, showing a substantial acceleration ratio of about 14.27 compared to the traditional CPU serial algorithm with an average processing time of around 420.46 ms. The study aims to refine the GPU parallelization algorithm for continued improvement in computational efficiency and overall performance. The anticipated applications of this research include providing crucial technical support for the perception and monitoring of crop growth traits in agricultural production, contributing to the modernization and advancement of intelligence in the field.

A New and Practical Model of Human-like Ascending Aorta Aneurysm in Rats.

INTRODUCTION: Ascending aortic aneurysm is a serious health risk. In order to study ascending aortic aneurysms, elastase and calcium ion treatment for aneurysm formation are mainly used, but their aneurysm formation time is long, the aneurysm formation rate is low. Thus, this study aimed to construct a rat model of ascending aorta aneurysm with a short modeling time and high aneurysm formation rate, which may mimic the pathological processes of human ascending aorta aneurysm. METHODS: Cushion needles with different pipe diameters (1.0, 1.2, 1.4 and 1.6 mm) were used to establish a human-like rat model of ascending aortic aneurysm by narrowing the ascending aorta of rats and increasing the force of blood flow on the vessel wall. The vascular diameters were evaluated using color Doppler ultrasonography after two weeks. The characteristics of ascending aortic aneurysm in rats were detected by Masson's trichrome staining, Verhoeff's Van Gieson staining and hematoxylin and eosin staining while RT-PCR were utilized to assess the total RNA of cytokine interleukin-1ß, interleukin 6, transforming growth factor-beta1 and metalloproteinase 2. RESULTS: Two weeks after surgery, the ultrasound images and the statistical analysis demonstrated that the diameter of the ascending aorta in rats increased more than 1.5 times, similar to that in humans, indicating the success of animal modeling of ascending aortic aneurysm. Moreover, the optimal constriction diameter of the ascending aortic aneurysm model is 1.4 mm by the statistical analysis of the rate of ascending aortic aneurysm and mortality rate in rats with different constriction diameters. CONCLUSIONS: The human-like ascending aortic aneurysm model developed in this study can be used for the studies of the pathological processes and mechanisms in ascending aortic aneurysm in a more clinically relevant fashion.

VThunter: a database for single-cell screening of virus target cells in the animal kingdom.

Viral infectious diseases are a devastating and continuing threat to human and animal health. Receptor binding is the key step for viral entry into host cells. Therefore, recognizing viral receptors is fundamental for understanding the potential tissue tropism or host range of these pathogens. The rapid advancement of single-cell RNA sequencing (scRNA-seq) technology has paved the way for studying the expression of viral receptors in different tissues of animal species at single-cell resolution, resulting in huge scRNA-seq datasets. However, effectively integrating or sharing these datasets among the research community is challenging, especially for laboratory scientists. In this study, we manually curated up-to-date datasets generated in animal scRNA-seq studies, analyzed them using a unified processing pipeline, and comprehensively annotated 107 viral receptors in 142 viruses and obtained accurate expression signatures in 2 100 962 cells from 47 animal species. Thus, the VThunter database provides a user-friendly interface for the research community to explore the expression signatures of viral receptors. VThunter offers an informative and convenient resource for scientists to better understand the interactions between viral receptors and animal viruses and to assess viral pathogenesis and transmission in species. Database URL: https://db.cngb.org/VThunter/.

Surface Lattice Modulation Enables Stable Cycling of High-Loading All-solid-state Batteries at High Voltages.

Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all-solid-state Li-ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+-doped, cation-disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium-deficient layer featuring a rock-salt-like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high-loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide-based ASSBs at high voltages.

Comparative analysis of single cell lung atlas of bat, cat, tiger, and pangolin.

Horseshoe bats (Rhinolophus sinicus) might help maintain coronaviruses severely affecting human health, such as severe acute respiratory syndrome coronavirus (SARS-CoV). Bats may be more tolerant of viral infection than other mammals due to their unique immune system, but the exact mechanism remains to be fully explored. During the coronavirus disease 2019 (COVID-19) pandemic, multiple animal species were diseased by coronavirus infection, especially in the respiratory system. Herein, a comparative analysis with single nucleus transcriptomic data of the lungs across four species, including horseshoe bat, cat, tiger, and pangolin, were conducted. The distribution of entry factors for twenty-eight respiratory viruses was characterized for the four species. Our findings might increase our understanding of the immune background of horseshoe bats.

A New 3D Iodoargentate Hybrid: Structure, Optical/Photoelectric Performance and Theoretical Research.

The explorations of new three-dimensional (3D) microporous metal halides, especially the iodoargentate-based hybrids, and understanding of their structure-activity relationships are still quite essential but full of great challenges. Herein, with the aromatic 4,4'-dpa (4,4'-dpa = 4,4'-dipyridylamine) ligands as the structural directing agents, we solvothermal synthesized and structurally characterized a novel member of microporous iodoargentate family, namely [H2-4,4'-dpa]Ag6I8 (1). Compound 1 possesses a unique and complicated 3D [Ag6I8]n2n- anionic architecture that was built up from the unusual hexameric [Ag6I13] secondary building units (SBUs). Research on optical properties indicated that compound 1 exhibited semiconductor behavior, with an optical band gap of 2.50 eV. Under the alternate irradiation of light, prominent photoelectric switching abilities could be achieved by compound [H2-4,4'-dpa]Ag6I8, whose photocurrent densities (0.37 µA·cm-2 for visible light and 1.23 µA·cm-2 for full-spectrum) compared well with or exceeded those of some high-performance halide counterparts. Further theoretical calculations revealed that the relatively dispersed conduction bands (CBs) structures in compound 1 induced higher electron mobilities, which may be responsible for its good photoelectricity. Presented in this work also comprised the analyses of Hirshfeld surface, powder X-ray diffractometer (PXRD), thermogravimetric measurement, energy-dispersive X-ray spectrum (EDX) along with X-ray photoelectron spectroscopy (XPS).

Creation of moiré bands in a monolayer semiconductor by spatially periodic dielectric screening.

Moiré superlattices of two-dimensional van der Waals materials have emerged as a powerful platform for designing electronic band structures and discovering emergent physical phenomena. A key concept involves the creation of long-wavelength periodic potential and moiré bands in a crystal through interlayer electronic hybridization or atomic corrugation when two materials are overlaid. Here we demonstrate a new approach based on spatially periodic dielectric screening to create moiré bands in a monolayer semiconductor. This approach relies on reduced dielectric screening of the Coulomb interactions in monolayer semiconductors and their environmental dielectric-dependent electronic band structure. We observe optical transitions between moiré bands in monolayer WSe2 when it is placed close to small-angle-misaligned graphene on hexagonal boron nitride. The moiré bands are a result of long-range Coulomb interactions, which are strongly gate tunable, and can have versatile superlattice symmetries independent of the crystal lattice of the host material. Our result also demonstrates that monolayer semiconductors are sensitive local dielectric sensors.

Stripe phases in WSe2/WS2 moiré superlattices.

Stripe phases, in which the rotational symmetry of charge density is spontaneously broken, occur in many strongly correlated systems with competing interactions1-11. However, identifying and studying such stripe phases remains challenging. Here we uncover stripe phases in WSe2/WS2 moiré superlattices by combining optical anisotropy and electronic compressibility measurements. We find strong electronic anisotropy over a large doping range peaked at 1/2 filling of the moiré superlattice. The 1/2 state is incompressible and assigned to an insulating stripe crystal phase. Wide-field imaging reveals domain configurations with a preferential alignment along the high-symmetry axes of the moiré superlattice. Away from 1/2 filling, we observe additional stripe crystals at commensurate filling 1/4, 2/5 and 3/5, and compressible electronic liquid crystal states at incommensurate fillings. Our results demonstrate that two-dimensional semiconductor moiré superlattices are a highly tunable platform from which to study the stripe phases and their interplay with other symmetry breaking ground states.

Design and manufacture of miniaturized immersed imaging spectrometer for remote sensing.

A miniaturized immersed imaging spectrometer possessing long slit and large relative aperture is proposed. It is integrated monolithically with three concentric optical components. Through the chief ray tracing, we analyzed its astigmatism characteristic and then deduced the anastigmatic condition for long slit. Meanwhile, it is athermal by matching the suitable lens materials to compensate thermal defocus. Based on the anastigmatic and athermal conditions, we have designed a miniaturized VNIR immersed imaging spectrometer and developed the prototype. Its slit is 48 mm long and it is optically fast with an F-number of 2.5. The new form shows about 12 times smaller in volume than the classic Offner-Chrisp imaging spectrometer and weighs only 2 kg, and has excellent thermal adaptability while temperature changes between -40 °C and 60 °C. Meanwhile, fabrication of core elements and gluing process of the immersed imaging spectrometer are presented. Test results of the prototype show superior performance with high imaging quality and small smile and keystone distortions. Such miniaturized immersed imaging spectrometer will greatly improve the performance and reduce the costs of wide swath hyperspectral remote sensing, and is desirable for usage on small plane or satellite platforms.

Long-slit polarization-insensitive imaging spectrometer for wide-swath hyperspectral remote sensing from a geostationary orbit.

To improve the swath width and quantitative accuracy of hyperspectral payloads on a geostationary orbit, a long-slit polarization-insensitive imaging spectrometer is designed and demonstrated in this paper. For the wide swath, several long-slit spectrometers with the same specification have been designed and compared. The result shows that the Wynne-Offner spectrometer has advantages in increasing slit length and reducing volume, and it is suitable for being spliced for ultra-wide swath. To solve the problem of inaccurate radiation measuring caused by the polarization of imaging spectrometers, the requirement for linear polarization sensitivity (LPS) is theoretically analyzed and assessed. As diffraction grating is the main polarization-sensitive element in an imaging spectrometer, we propose to increase the apical angle of the grating groove to reduce its LPS and compensate its residual polarization by specially polarized optical films coated on lens surfaces, thus the polarization-insensitive system is achieved. At last, a VNIR spectrometer with superior spatial and spectral performance is developed, and its slit is 61.44 mm long. The maximum LPS of this system is reduced from 10.0% to 2.3% (test 2.5%) after the depolarization design, which greatly reduces the uncertainty of the measuring radiation caused by polarization. The developed imaging spectrometer can play a role in quantitative hyperspectral remote sensing, especially in wide-swath applications on geostationary orbit.

Quantum Oscillations in Two-Dimensional Insulators Induced by Graphite Gates.

We demonstrate a mechanism for magnetoresistance oscillations in insulating states of two-dimensional (2D) materials arising from the interaction of the 2D layer and proximal graphite gates. We study a series of devices based on different 2D systems, including mono- and bilayer T_{d}-WTe_{2}, MoTe_{2}/WSe_{2} moiré heterobilayers, and Bernal-stacked bilayer graphene, which all share a similar graphite-gated geometry. We find that the 2D systems, when tuned near an insulating state, generically exhibit magnetoresistance oscillations corresponding to a high-density Fermi surface, in contravention of naïve band theory. Simultaneous measurement of the resistivity of the graphite gates shows that the oscillations of the sample layer are precisely correlated with those of the graphite gates. Further supporting this connection, the oscillations are quenched when the graphite gate is replaced by a low-mobility metal, TaSe_{2}. The observed phenomenon arises from the oscillatory behavior of graphite density of states, which modulates the device capacitance and, as a consequence, the carrier density in the sample layer even when a constant electrochemical potential is maintained between the sample and the gate electrode. Oscillations are most pronounced near insulating states where the resistivity is strongly density dependent. Our study suggests a unified mechanism for quantum oscillations in graphite-gated 2D insulators based on electrostatic sample-gate coupling.

Genetic variability and functional implication of HPV16 from cervical intraepithelial neoplasia in Shanghai women.

Human papillomavirus (HPV)16 gene mutation is usually associated with persistent HPV infection and cervical intraepithelial neoplasia (CIN). However, the functional implications of HPV16 mutations remain poorly understood.145 LCR/E6/E7 of the HPV16 isolates were amplified and sequenced, and HPV16 integration status was detected. In total, 89 SNPs (68 in the LCR, 13 in E6, 8 in E7) were discovered, 11 of which were nonsynonymous mutations (8 in E6, 3 in E7). The H85Y and E120D variants in E6 were significantly reduced in the high-grade squamous intraepithelial lesion (HSIL) group compared to the T," a potential binding site for TATA-binding protein, is the most common in LCR variants. A4 (Asian) was associated with an increased risk of HSIL compared to A1-3(P = .009). The H85/E120 in E6 and N29 in HPV16 E7 might play a critical role in carcinogenesis by disrupting p53 and Rb degradation due to affecting their interaction, respectively. In a word, the findings in this study provide preventative and therapeutic interventions of HPV16 -related cervical lesions/cancer.

Glyburide attenuates ozone-induced pulmonary inflammation and injury by blocking the NLRP3 inflammasome.

Glyburide is a classic antidiabetic drug that is dominant in inflammation regulation, but its specific role in ozone-induced lung inflammation and injury remains unclear. In order to investigate whether glyburide prevents ozone-induced pulmonary inflammation and its mechanism, C57BL/6 mice were intratracheally pre-instilled with glyburide or the vehicle 1 hour before ozone (1 ppm, 3 hours) or filtered air exposure. After 24 hours, the total inflammatory cells and total protein in bronchoalveolar lavage fluid (BALF) were detected. The pathological alternations in lung tissues were evaluated by HE staining. The expression of NLRP3, interleukin-1ß (IL-1ß), and IL-18 protein in lung tissues was detected by immunohistochemistry. Western blotting was used to examine the levels of caspase-1 p10 and active IL-1ß protein. Levels of IL-1ß and IL-18 in BALF were measured using ELISA kits. Glyburide treatment decreased the total cells in BALF, the inflammatory score, and the mean linear intercept induced by ozone in lung tissues. In addition, glyburide inhibited the expression of NLRP3, IL-18, and IL-1ß protein in lung tissues, and also suppressed NLRP3 inflammasome activation, including caspase-1 p10, active IL-1ß protein in lung tissues, IL-1ß, and IL-18 in BALF. These results demonstrate that glyburide effectively attenuates ozone-induced pulmonary inflammation and injury via blocking the NLRP3 inflammasome.

Analytical design of athermal ultra-compact concentric catadioptric imaging spectrometer.

An ultra-compact concentric catadioptric imaging spectrometer with large relative aperture and long slit is proposed. It consists of three optical components integrated monolithically in a concentric layout. Its astigmatism theory is discussed through tracing its chief ray and its athermalization is realized by optimizing lens materials. A high-speed (F/2.25) long-slit (48mm) VNIR design with high imaging quality and small distortions is presented. Results show a 10× reduction in volume than classic designs based on Offner-Chrisp configuration and a 1.9× reduction in length than Dyson configuration. Moreover, the design shows superior thermal adaptability with negligible decline in imaging quality while operating temperature changes between -30 ℃ and 70 ℃.

Increasing electrical conductivity of upconversion materials by in situ binding with graphene.

Upconversion nanoparticles (UCNPs) hold promise as near-infrared light converters to enhance the efficiency of solar cells. However, the prevalent use of UCNPs in solar cells is restricted by their poor electrical conductivity and low emission efficiency. Here reduced graphene oxide (rGO)-NaYF4:Yb(3+)/Er(3+) composites are proposed to achieve good electrical conductivity due to the high charge carrier mobility of rGO. Composites of rGO and UCNPs combined by a chemical bond are in situ synthesized by the hydrothermal method, followed by a reduction process. The contact of UCNPs with rGO is proved by SEM, and the binding between the rGO-UCNP composites is confirmed by Fourier transform infrared spectroscopy. The composites are doped into the photoanode of a solar cell. As anticipated, electrochemical impedance spectroscopy confirms the good electrical conductivity of the in situ synthesized rGO-UCNPs. Furthermore, the use of rGO-UCNPs in solar cells enables an enhancement in short-circuit current density and overall efficiency by about 10%. These findings reveal that the combination of UCNPs with rGO opens up new opportunities of extending the use of UCNPs in the area of solar energy harvesting.

Comparison of laparoscopic subtotal colectomy with posterior vaginal suspension and laparoscopic subtotal colectomy with transvaginal repair for patients with slow-transit constipation complicated with rectocele: a non-randomized comparative study in a single center.

BACKGROUND: Slow-transit constipation complicated with rectocele is a mixed constipation difficult to treat by surgery. Different hospitals and surgeons may employ different surgical procedures. The present study aims to compare the efficacy of laparoscopic subtotal colectomy (LSC) with posterior vaginal suspension and LSC with transvaginal repair for patients having refractory slow-transit constipation complicated with rectocele. METHODS: This paper is a retrospective study of 64 patients having refractory slow-transit constipation complicated with rectocele. Admitted from January 2002 to December 2012, the 64 patients were non-randomly divided into two groups: patients who underwent LSC with posterior vaginal suspension (Group A, 36 patients) and patients who underwent LSC with transvaginal repair (Group B, 28 patients). RESULTS: There was no statistically significant difference (P > 0.05) in preoperative general characteristics and Wexner constipation score between Group A and Group B. There was no statistically significant difference (P > 0.05) in operative time and intraoperative blood loss between the two groups. One month after the surgery, there was no statistically significant difference (P > 0.05) in early postoperative complications, constipation recurrence rate, degree of improvement in constipation symptoms, and Wexner constipation score between the two groups. But 1-year follow-up results show that there was statistically significant difference (P < 0.05) in constipation recurrence rate, gastrointestinal quality of life index, the degree of improvement in constipation symptoms, and Wexner constipation score between the two groups. CONCLUSION: Compared with the LSC with transvaginal repair, the LSC with posterior vaginal suspension demonstrated better efficacy in treating refractory slow-transit constipation complicated with rectocele.