Functional and structural basis of human parainfluenza virus type 3 neutralization with human monoclonal antibodies.

Human parainfluenza virus type 3 (hPIV3) is a respiratory pathogen that can cause severe disease in older people and infants. Currently, vaccines against hPIV3 are in clinical trials but none have been approved yet. The haemagglutinin-neuraminidase (HN) and fusion (F) surface glycoproteins of hPIV3 are major antigenic determinants. Here we describe naturally occurring potently neutralizing human antibodies directed against both surface glycoproteins of hPIV3. We isolated seven neutralizing HN-reactive antibodies and a pre-fusion conformation F-reactive antibody from human memory B cells. One HN-binding monoclonal antibody (mAb), designated PIV3-23, exhibited functional attributes including haemagglutination and neuraminidase inhibition. We also delineated the structural basis of neutralization for two HN and one F mAbs. MAbs that neutralized hPIV3 in vitro protected against infection and disease in vivo in a cotton rat model of hPIV3 infection, suggesting correlates of protection for hPIV3 and the potential clinical utility of these mAbs.

Resilient Growth of a Highly Crystalline Topological Insulator-Superconductor Heterostructure Enabled by an Ex Situ Nitride Film.

Highly crystalline and easily feasible topological insulator-superconductor (TI-SC) heterostructures are crucial for the development of practical topological qubit devices. The optimal superconducting layer for TI-SC heterostructures should be highly resilient against external contamination and structurally compatible with TIs. In this study, we provide a solution to this challenge by showcasing the growth of a highly crystalline TI-SC heterostructure using refractory TiN (111) as the superconducting layer. This approach can eliminate the need for in situ cleavage or growth. More importantly, the TiN surface shows high resilience against contaminations during air exposure, as demonstrated by the successful recyclable growth of Bi2Se3. Our findings indicate that TI-SC heterostructures based on nitride films are compatible with device fabrication techniques, paving the way to the realization of practical topological qubit devices in the future.

Broadband, High-Reflectivity Dielectric Mirrors at Wafer Scale: Combining Photonic Crystal and Metasurface Architectures for Advanced Lightsails.

Highly ambitious initiatives aspire to propel a miniature spacecraft to a neighboring star within a human generation, leveraging the radiation pressure of lasers for propulsion. One major challenge for this enormous feat is to build a meter-scale, ultralow mass lightsail with broadband reflectivity. In this work, we present the design and fabrication of a lightsail composed of two distinct dielectric layers with photonic crystal/metasurface structure covering a 4" wafer. We achieved broadband reflection of >70% spanning over the full Doppler-shifted laser wavelength range during spacecraft acceleration with a low total mass in the range of a few grams when scaled up to meter size. Furthermore, we find new paths to reliably fabricate these subwavelength structures over macroscopic areas and then systematically characterize their optical performance, confirming their suitability for future lightsail applications. Our innovative device and precise nanofabrication approaches represent a significant leap toward interstellar exploration.

Momentum-Resolved Electronic Structures and Strong Electronic Correlations in Graphene-like Nitride Superconductors.

Although transition-metal nitrides have been widely applied for several decades, experimental investigations of their high-resolution electronic band structures are rare due to the lack of high-quality single-crystalline samples. Here, we report on the first momentum-resolved electronic band structures of titanium nitride (TiN) films, which are remarkable nitride superconductors. The measurements of the crystal structures and electrical transport properties confirmed the high quality of these films. More importantly, from a combination of high-resolution angle-resolved photoelectron spectroscopy and first-principles calculations, the extracted Coulomb interaction strength of TiN films can be as large as 8.5 eV, whereas resonant photoemission spectroscopy yields a value of 6.26 eV. These large values of Coulomb interaction strength indicate that superconducting TiN is a strongly correlated system. Our results uncover the unexpected electronic correlations in transition-metal nitrides, potentially providing a perspective not only to understand their emergent quantum states but also to develop their applications in quantum devices.

Active-feedback quantum control of an integrated low-frequency mechanical resonator.

Preparing a massive mechanical resonator in a state with quantum limited motional energy provides a promising platform for studying fundamental physics with macroscopic systems and allows to realize a variety of applications, including precise sensing. While several demonstrations of such ground-state cooled systems have been achieved, in particular in sideband-resolved cavity optomechanics, for many systems overcoming the heating from the thermal bath remains a major challenge. In contrast, optomechanical systems in the sideband-unresolved limit are much easier to realize due to the relaxed requirements on their optical properties, and the possibility to use a feedback control schemes to reduce the motional energy. The achievable thermal occupation is ultimately limited by the correlation between the measurement precision and the back-action from the measurement. Here, we demonstrate measurement-based feedback cooling on a fully integrated optomechanical device fabricated using a pick-and-place method, operating in the deep sideband-unresolved limit. With the large optomechanical interaction and a low thermal decoherence rate, we achieve a minimal average phonon occupation of 0.76 when pre-cooled with liquid helium and 3.5 with liquid nitrogen. Significant sideband asymmetry for both bath temperatures verifies the quantum character of the mechanical motion. Our method and device are ideally suited for sensing applications directly operating at the quantum limit, greatly simplifying the operation of an optomechanical system in this regime.

Enhanced Quantum Anomalous Hall Effect with an Active Capping Layer.

The quantum anomalous Hall effect (QAHE) was discovered a decade ago but is still not utilized beyond a handful of research groups, due to numerous limitations such as extremely low temperature, electric-field-effect gating requirement, small sample sizes, and environmental aging effect. Here, we present a robust platform that provides effective solutions to these problems. Specifically, on this platform, we observe QAH signatures at record-high temperatures, with a Hall conductance of 1.00 e2/h at 2.0 K, 0.98 e2/h at 4.2 K, and 0.92 e2/h at 10 K, on centimeter-scale substrates, without electric-field-effect gating. The key ingredient is an active CrOx capping layer, which substantially boosts the ferromagnetism while suppressing environmental degradation. With this development, QAHE will now be accessible to much broader applications than before.

How does 2D and 3D of urban morphology affect the seasonal land surface temperature in Island City? A block-scale perspective.

The global climate warming caused by urbanization has significantly affected the urban environment. Whilst land surface temperature (LST) is an important factor reflecting urban temperature, previous research on LST mostly focused on two-dimensional (2D) factors and rarely mentioned about the role of three-dimensional (3D) factors, particularly the LST variation characteristics of island cities. Therefore, this study examined the seasonal variation characteristics of urban LST by analyzing the impact of 2D and 3D urban morphology factors of different urban block types on LST in Xiamen Island. The main results are as follows. First, compact low layer (CL), a block type with a higher density of low-rise buildings, has a higher LST in any season. Under the same block density (BD), the higher the block average height (BH), the lower the LST. Second, among the 2D urban morphology factors, normalized difference vegetation index (NDVI) was the main factor for cities to reduce urban LST, especially in summer, while normalized difference built-up index (NDBI) was the opposite. Different from land cities, we found a positive correlation between modified normalized difference water body index (MNDWI) and LST in autumn and winter. Third, in the 3D urban morphology factors, sky view factor (SVF) was significantly positively correlated with LST, while building fluctuation (BF) was negatively correlated. The higher the SVF, the worse the radiation shielding effect between buildings. On the contrary, the higher the BF, the higher the building undulation, and the better the building radiation shielding. These findings should provide some quantitative insights for the future construction and planning of island cities, which can be used to improve the thermal environment of island cities and support the sustainable development of cities.

Monolayer Superconductivity and Tunable Topological Electronic Structure at the Fe(Te,Se)/Bi2 Te3 Interface.

The interface between 2D topological Dirac states and an s-wave superconductor is expected to support Majorana-bound states (MBS) that can be used for quantum computing applications. Realizing these novel states of matter and their applications requires control over superconductivity and spin-orbit coupling to achieve spin-momentum-locked topological interface states (TIS) which are simultaneously superconducting. While signatures of MBS have been observed in the magnetic vortex cores of bulk FeTe0.55 Se0.45 , inhomogeneity and disorder from doping make these signatures unclear and inconsistent between vortices. Here superconductivity is reported in monolayer (ML) FeTe1-y Sey (Fe(Te,Se)) grown on Bi2 Te3 by molecular beam epitaxy (MBE). Spin and angle-resolved photoemission spectroscopy (SARPES) directly resolve the interfacial spin and electronic structure of Fe(Te,Se)/Bi2 Te3 heterostructures. For y = 0.25, the Fe(Te,Se) electronic structure is found to overlap with the Bi2 Te3 TIS and the desired spin-momentum locking is not observed. In contrast, for y = 0.1, reduced inhomogeneity measured by scanning tunneling microscopy (STM) and a smaller Fe(Te,Se) Fermi surface with clear spin-momentum locking in the topological states are found. Hence, it is demonstrated that the Fe(Te,Se)/Bi2 Te3 system is a highly tunable platform for realizing MBS where reduced doping can improve characteristics important for Majorana interrogation and potential applications.

Irradiated lung cancer cell-derived exosomes modulate macrophage polarization by inhibiting MID1 via miR-4655-5p.

Radiation Pneumonitis (RP) is one of the most common and severe complication in patients receiving thoracic radiotherapy. The release of cytokines contribute to activating the RP process. Macrophages also play an important role in the pathogenesis of RP. The differential activation of macrophages is regulated by microRNA (miRNA). Exosomes containing miRNAs are one of the important ways to mediate cellular communication. However, the exosomes mediate communication between tumor cells and macrophages during the pathogenesis of RP remains understudied. In this study, we isolated and characterized the exosomes secreted by lung cancer cells after irradiation. Co-culture of exosomes with macrophages revealed that exosomes could induce macrophage proliferation activation and M2 polarization. miRNA array was used to analyze the differential expression of miRNAs in exosomes, and it was found that miR-4655-5p was stably and highly expressed in exosomes. The function of miR-4655-5p in macrophages was confirmed by overexpression/inhibition of miR-4655-5p expression in macrophages. The targeting association between miR-4655-5p and MID1 was determined by bioinformatics prediction followed by a confirmatory dual luciferase reporter assay. We showed that miR-4655-5p regulate the macrophage proliferation and inflammatory response by forming a negative regulatory loop that alters MID1 activity and its downstream PP2Ac. Overall, our results indicated that exosomal miR-4655-5p secreted by lung cancer cells after irradiation promoted the proliferation and M2 polarization of macrophages. It can be speculated that exosomes play an immunomodulatory role in the pathogenesis of RP and provided a new target for the prevention and treatment of RP.

Nano-optical method for transforming a single yeast cell using exogenous genes.

We report a highly efficient nano-optical method for transforming a single yeast cell using exogenous genes. It used laser tweezers or micromanipulators to immobilize the cell immersed in a DNA solution and created a transient nano-sized hole on its cell wall concurrently with laser scissors to deliver nano moles of DNA into the cell. With this method, one can directly transfer the naked DNA of exogenous genes into yeast cells for transformation. We successfully transformed S. cerevisiae yeasts respectively with GFP (Green Fluorescent Protein) plasmid and the nucleic acid extraction of a bacteria GF1 from the gut of Coptotermes formosanus termites. The experimental results demonstrated that the recombinants had high survival rate and transformation efficiency (28%). The recombinant GFP-yeast system showed green fluorescence for generations. GF1 DNA sequences were incorporated into the yeast genome as a heritable component with stable expression for multi-generations so that the recombinant GF1-yeast had a strong capability of digesting biomass as GF1. Our method would apply to different cells with cell walls for various gene transformations.

Superconducting Fourfold Fe(Te,Se) Film on Sixfold Magnetic MnTe via Hybrid Symmetry Epitaxy.

Epitaxial Fe(Te,Se) thin films have been grown on various substrates but never been grown on magnetic layers. Here we report the epitaxial growth of fourfold Fe(Te,Se) film on a sixfold antiferromagnetic insulator, MnTe. The Fe(Te,Se)/MnTe heterostructure shows a clear superconducting transition at around 11 K, and the critical magnetic field measurement suggests the origin of the superconductivity to be bulk-like. Structural characterizations suggest that the uniaxial lattice match between Fe(Te,Se) and MnTe allows a hybrid symmetry epitaxy mode, which was recently discovered between Fe(Te,Se) and Bi2Te3. Furthermore, the Te/Fe flux ratio during deposition of the Fe(Te,Se) layer is found to be critical for its superconductivity. Now that superconducting Fe(Te,Se) can be grown on two related hexagonal platforms, Bi2Te3 and MnTe, this result opens a new possibility of combining topological superconductivity of Fe(Te,Se) with the rich physics in the intrinsic magnetic topological materials (MnTe)n(Bi2Te3)m family.

Geometric Tuning of Stress in Predisplaced Silicon Nitride Resonators.

We introduce a novel method to geometrically tune the tension in prestrained resonators by making Si3N4 strings with a designed predisplacement. This enables us, for example, to study their dissipation mechanisms, which are strongly dependent on the stress. After release of the resonators from the substrate, their static displacement is extracted using scanning electron microscopy. The results match finite-element simulations, which allows a quantitative determination of the resulting stress. The in- and out-of-plane eigenmodes are sensed using on-chip Mach-Zehnder interferometers, and the resonance frequencies and quality factors are extracted. The geometrically controlled stress enables tuning not only of the frequencies but also of the damping rate. We develop a model that quantitatively captures the stress dependence of the dissipation in the same SiN film. We show that the predisplacement shape provides additional flexibility, including control over the frequency ratio and the quality factor for a targeted frequency.

Oxygen vacancy-rich 2D GO/BiOCl composite materials for enhanced photocatalytic performance and semiconductor energy band theory research.

Bismuth-based materials are extensively studied for photocatalytic applications because of their unique crystal structure. Herein, we reported a binary graphene oxide (GO)/BiOCl composite material prepared by a hydrothermal method and analyzed its photodegradation mechanism through the semiconductor energy band theory. The degradation rate of the GO/BiOCl composite towards Rhodamine B could reach 93.6% within 8 min, and its performance exceeded that of most photocatalysts. The influencing factors for improving the photocatalytic activity are as follows: (1) abundant oxygen vacancies generated on the tight recombination interface; (2) a 2D-2D electron transfer channel between GO and BiOCl; and (3) GO acting as a load to provide more reaction sites for BiOCl nanosheets. This work provides a simple solution and theoretical explanation for the rapid degradation of pollutants, and has broad application prospects.

AI Aided Analysis on Saliva Crystallization of Pregnant Women for Accurate Estimation of Delivery Date and Fetal Status.

Saliva contains similar molecular components to serum. Analysis of saliva can provide important diagnostic information about the body. Here we report an artificial intelligence (AI) aided home-based method that can let pregnant women perform daily monitoring on their pregnant status and accurate prediction on their delivery date by the pattern analysis of their salivary crystals. The method was developed based on the information obtained from our investigation on the saliva samples of 170 pregnant women about the correlation of the salivary crystal pattern with pregnant age and fetal status. It demonstrated that the patterns of salivary crystallization could act as indicators of the pregnant age, fetal state, and some medical conditions of pregnant women. On this basis, with the aid of AI recognition and analysis of the fractal dimension and some characteristic crystals in the salivary crystallization, we performed estimation on the delivery date in both quantitative and qualitative manners. The accuracy of the prediction on 15 pregnant women was satisfactory: 100% delivering in the predicted week, 93.3% within the estimated three days, and 86.7% on the day as the prediction. We also developed a simple smartphone-based AI-aided salivary crystal imaging and analysis device as an auxiliary means to let pregnant women monitor their fetal status daily at home and predict their delivery date with adequate accuracy.

Spacer-Layer-Tunable Magnetism and High-Field Topological Hall Effect in Topological Insulator Heterostructures.

Controlling magnetic order in magnetic topological insulators (MTIs) is a key to developing spintronic applications with MTIs and is commonly achieved by changing the magnetic doping concentration, which inevitably affects the spin-orbit coupling strength and the topological properties. Here, we demonstrate tunable magnetic properties in topological heterostructures over a wide range, from a ferromagnetic phase with a Curie temperature of around 100 K all the way to a paramagnetic phase, while keeping the overall chemical composition the same, by controlling the thickness of nonmagnetic spacer layers between two atomically thin magnetic layers. This work showcases that spacer-layer control is a powerful tool to manipulate magneto-topological functionalities in MTI heterostructures. Furthermore, the interaction between the MTI and the Cr2O3 buffer layers also leads to a robust topological Hall effect surviving up to a record-high 6 T of magnetic field, shedding light on the critical role of interfacial layers in thin-film topological materials.

Hybrid Symmetry Epitaxy of the Superconducting Fe(Te,Se) Film on a Topological Insulator.

It is challenging to grow an epitaxial 4-fold compound superconductor (SC) on a 6-fold topological insulator (TI) platform due to the stringent lattice-matching requirement. Here, we demonstrate that Fe(Te,Se) can grow epitaxially on a TI (Bi2Te3) layer due to accidental, uniaxial lattice match, which is dubbed as "hybrid symmetry epitaxy". This new growth mode is critical to stabilizing robust superconductivity with TC as high as 13 K. Furthermore, the superconductivity in this FeTe1-xSex/Bi2Te3 system survives in the Te-rich phase with Se content as low as x = 0.03 but vanishes at Se content above x = 0.56, exhibiting a phase diagram that is quite different from that of the conventional Fe(Te,Se) systems. This unique heterostructure platform that can be formed in both TI-on-SC and SC-on-TI sequences opens a route to unprecedented topological heterostructures.

BPA modulates the WDR5/TET2 complex to regulate ERß expression in eutopic endometrium and drives the development of endometriosis.

Overexpression of estrogen receptor ß (ERß) in endometrium contributes to endometriosis (EM) pathogenesis. Trimethylation of the H3 lysine (K) 4 (H3K4me3) in promoters is strongly correlated with gene expression. This study aimed to explore the effects of bisphenol A (BPA) exposure on EM development from the perspective of the regulation of ERß expression in eutopic endometrium via the H3K4me3-related epigenetic pathway. A mouse EM model was established to investigate the effects of BPA. Immortalized human normal endometrial stromal cells (iESCs) were cultured and treated with BPA to explore the underlying mechanism. Eutopic endometria from patients with or without EM were collected and analyzed. Results showed that BPA elevated ERß expression in mouse eutopic endometrium and promoted lesion growth. BPA also promoted WD repeat domain 5 (WDR5) expression and upregulated H3K4me3 levels in the ERß promoter and Exon 1. Further research indicated that WDR5 interacted with tet methylcytosine dioxygenase 2 (TET2), while BPA exposure enhanced the interaction between these two proteins, promoted the recruitment of the WDR5/TET2 complex to the ERß promoter and Exon 1, and inhibited DNA methylation of CpG islands. The WDR5/TET2 interaction was essential for BPA-induced ERß overexpression. Enhanced WDR5/TET2 interaction was also observed in eutopic endometria from EM patients. Further results showed that BPA upregulated WDR5 expression through the G protein-coupled estrogen receptor (GPER)-mediated PI3K/mTOR signaling pathway. In conclusion, our study suggests that BPA exposure promotes EM development by upregulating ERß expression in eutopic endometrium via the WDR5/TET2-mediated epigenetic pathway.

Effects of Low-Dose X-Ray on Cell Growth, Membrane Permeability, DNA Damage and Gene Transfer Efficiency.

BACKGROUND: We aimed to reveal if low dose X-rays would induce harmful or beneficial effect or dual response on biological cells and whether there are conditions the radiation can enhance gene transfer efficiency and promote cell growth but without damage to the cells. METHOD: A systematic study was performed on the effects of Kilo-V and Mega-V X-rays on the cell morphology, viability, membrane permeability, DNA damage, and gene transfection of 293 T and CHO cells. RESULTS: The Kilo-V X-rays of very low doses from 0.01 to 0.04 Gray in principle didn't induce any significant change in cell morphology, growth, membrane permeability, and cause DNA damage. The Mega-V X-ray had a damage threshold between 1.0 and 1.5 Gray. The 0.25 Gray Mega-V-X-ray could promote cell growth and gene transfer, while the 1.5 Gray Mega-V X-ray damaged cells. CONCLUSION: The very low dose of KV X-rays is safe to cells, while the effects of Mega-V-X-rays are dose-dependent. Mega-V-X-rays with a dose higher than the damage threshold would be harmful, that between 1.0 -1.5 Gray can evoke dual effects, whereas 0.25 Gray MV X-ray is beneficial for both cell growth and gene transfer, thus would be suitable for radiation-enhanced gene transfection.

Studies on the origin of the interfacial superconductivity of Sb2Te3/Fe1+yTe heterostructures.

The recent discovery of the interfacial superconductivity (SC) of the Bi2Te3/Fe1+yTe heterostructure has attracted extensive studies due to its potential as a novel platform for trapping and controlling Majorana fermions. Here we present studies of another topological insulator (TI)/Fe1+yTe heterostructure, Sb2Te3/Fe1+yTe, which also has an interfacial 2-dimensional SC. The results of transport measurements support that reduction of the excess Fe concentration of the Fe1+yTe layer not only increases the fluctuation of its antiferromagnetic (AFM) order but also enhances the quality of the SC of this heterostructure system. On the other hand, the interfacial SC of this heterostructure was found to have a wider-ranging TI-layer thickness dependence than that of the Bi2Te3/Fe1+yTe heterostructure, which is believed to be attributed to the much higher bulk conductivity of Sb2Te3 that enhances indirect coupling between its top and bottom topological surface states (TSSs). Our results provide evidence of the interplay among the AFM order, itinerant carries from the TSSs, and the induced interfacial SC of the TI/Fe1+yTe heterostructure system.