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Quantum anomalous Hall goes intrinsicQuantum anomalous Hall effect—the appearance of quantized Hall conductance at zero magnetic field—has been observed in thin films of the topological insulator Bi2Se3 doped with magnetic atoms. The doping, however, introduces inhomogeneity, reducing the temperature at which the effect occurs. Two groups have now observed quantum anomalous Hall effect in intrinsically magnetic materials (see the Perspective by Wakefield and Checkelsky). Serlin et al. did so in twisted bilayer graphene aligned to hexagonal boron nitride, where the effect enabled the switching of magnetization with tiny currents. In a complementary work, Deng et al. observed quantum anomalous Hall effect in the antiferromagnetic layered topological insulator MnBi2Te4.Science, this issue p. 900, p. 895; see also p. 848In a magnetic topological insulator, nontrivial band topology combines with magnetic order to produce exotic states of matter, such as quantum anomalous Hall (QAH) insulators and axion insulators. In this work, we probe quantum transport in MnBi2Te4 thin flakes—a topological insulator with intrinsic magnetic order. In this layered van der Waals crystal, the ferromagnetic layers couple antiparallel to each other; atomically thin MnBi2Te4, however, becomes ferromagnetic when the sample has an odd number of septuple layers. We observe a zero-field QAH effect in a five–septuple-layer specimen at 1.4 kelvin, and an external magnetic field further raises the quantization temperature to 6.5 kelvin by aligning all layers ferromagnetically. The results establish MnBi2Te4 as an ideal arena for further exploring various topological phenomena with a spontaneously broken time-reversal symmetry.

The occurrence of superconductivity in proximity to various strongly correlated phases of matter has drawn extensive focus on their normal state properties, to develop an understanding of the state from which superconductivity emerges 1 – 4 . The recent finding of superconductivity in layered nickelates raises similar interests 5 – 8 . However, transport measurements of doped infinite-layer nickelate thin films have been hampered by materials limitations of these metastable compounds: in particular, a high density of extended defects 9 – 11 . Here, by moving to a substrate (LaAlO 3 ) 0.3 (Sr 2 TaAlO 6 ) 0.7 that better stabilizes the growth and reduction conditions, we can synthesize the doping series of Nd 1– x Sr x NiO 2 essentially free from extended defects. In their absence, the normal state resistivity shows a low-temperature upturn in the underdoped regime, linear behaviour near optimal doping and quadratic temperature dependence for overdoping. This is phenomenologically similar to the copper oxides 2 , 12 despite key distinctions—namely, the absence of an insulating parent compound 5 , 6 , 9 , 10 , multiband electronic structure 13 , 14 and a Mott–Hubbard orbital alignment rather than the charge-transfer insulator of the copper oxides 15 , 16 . We further observe an enhancement of superconductivity, both in terms of transition temperature and range of doping. These results indicate a convergence in the electronic properties of both superconducting families as the scale of disorder in the nickelates is reduced. By moving to a substrate that better stabilizes conditions, the doping series of Nd 1– x Sr x NiO 2 is synthesized free from extended defects, resulting in enhancement of superconductivity in terms of transition temperature and range of doping.

The ability to tune material properties using gating by electric fields is at the heart of modern electronic technology. It is also a driving force behind recent advances in two-dimensional systems, such as the observation of gate electric-field-induced superconductivity and metal–insulator transitions. Here, we describe an ionic field-effect transistor (termed an iFET), in which gate-controlled Li ion intercalation modulates the material properties of layered crystals of 1T-TaS 2 . The strong charge doping induced by the tunable ion intercalation alters the energetics of various charge-ordered states in 1T-TaS 2 and produces a series of phase transitions in thin-flake samples with reduced dimensionality. We find that the charge-density wave states in 1T-TaS 2 collapse in the two-dimensional limit at critical thicknesses. Meanwhile, at low temperatures, the ionic gating induces multiple phase transitions from Mott-insulator to metal in 1T-TaS 2 thin flakes, with five orders of magnitude modulation in resistance, and superconductivity emerges in a textured charge-density wave state induced by ionic gating. Our method of gate-controlled intercalation opens up possibilities in searching for novel states of matter in the extreme charge-carrier-concentration limit. The high charge doping achieved in ionic field-effect transistors by lithium intercalation allows gate-controlled phase transitions in thin flakes of 1T-TaS 2 .

Electron–electron and electron–phonon interactions are two major driving forces that stabilize various charge-ordered phases of matter. In layered compound 1T-TaS 2 , the intricate interplay between the two generates a Mott-insulating ground state with a peculiar charge-density-wave (CDW) order. The delicate balance also makes it possible to use external perturbations to create and manipulate novel phases in this material. Here, we study a mosaic CDW phase induced by voltage pulses, and find that the new phase exhibits electronic structures entirely different from that of the original Mott ground state. The mosaic phase consists of nanometre-sized domains characterized by well-defined phase shifts of the CDW order parameter in the topmost layer, and by altered stacking relative to the layers underneath. We discover that the nature of the new phase is dictated by the stacking order, and our results shed fresh light on the origin of the Mott phase in 1T-TaS 2 . In correlated materials, new phases emerge when the balance between many-body interactions is perturbed. Here, Ma et al . induce a mosaic charge-density-wave phase out of Mott insulating state in layered 1T-TaS 2 by voltage pulses, which reveals a dominating role of interlayer stacking order.

The repair of skeletal defects in maxillofacial region remains an intractable problem, the rising technology of bone tissue engineering provides a new strategy to solve it. Scaffolds, a crucial element of tissue engineering, must have favorable biocompatibility as well as osteoinductivity. In this study, we prepared berberine/polycaprolactone/collagen (BBR/PCL/COL) scaffolds with different concentrations of berberine (BBR) (25, 50, 75 and 100 μg/mL) through electrospinning. The influence of dosage on scaffold morphology, cell behavior and in vivo bone defect repair were systematically studied. The results indicated that scaffolds could release BBR stably for up to 27 days. Experiments in vitro showed that BBR/PCL/COL scaffolds had appropriate biocompatibility in the concentration of 25–75 μg/mL, and 50 and 75 μg/mL scaffolds could significantly promote osteogenic differentiation of dental pulp stem cells. Scaffold with 50 μg/mL BBR was implanted into the critical bone defect of rats to evaluate the ability of bone repair in vivo. It was found that BBR/PCL/COL scaffold performed more favorable than polycaprolactone/collagen (PCL/COL) scaffold. Overall, our study is the first to evaluate the capability of in vivo bone repair of BBR/PCL/COL electrospun scaffold. The results indicate that BBR/PCL/COL scaffold has prospective potential for tissue engineering applications in bone regeneration therapy.

Formulations from nanotechnology platform promote therapeutic drug delivery and offer various advantages such as biocompatibility, non-inflammatory effects, high therapeutic output, biodegradability, non-toxicity, and biocompatibility in comparison with free drug delivery. Due to inherent shortcomings of conventional drug delivery to cancerous tissues, alternative nanotechnological-based approaches have been developed for such ailments. Ovarian cancer is the leading gynecological cancer with higher mortality rates due to its reoccurrence and late diagnosis. In recent years, the field of medical nanotechnology has witnessed significant progress in addressing existing problems and improving the diagnosis and therapy of various diseases including cancer. Nevertheless, the literature and current reviews on nanotechnology are mainly focused on its applications in other cancers or diseases. In this review, we focused on the nanoscale drug delivery systems for ovarian cancer targeted therapy and diagnosis, and different nanocarriers systems including dendrimers, nanoparticles, liposomes, nanocapsules, and nanomicelles for ovarian cancer have been discussed. In comparison to non-functionalized counterparts of nanoformulations, the therapeutic potential and preferential targeting of ovarian cancer through ligand functionalized nanoformulations' development has been reviewed. Furthermore, numerous biomarkers such as prostatic, mucin 1, CA-125, apoptosis repeat baculoviral inhibitor-5, human epididymis protein-4, and e-cadherin have been identified and elucidated in this review for the assessment of ovarian cancer. Nanomaterial biosensor-based tumor markers and their various types for ovarian cancer diagnosis are explained in this article. In association, different nanocarrier approaches for the ovarian cancer therapy have also been underpinned. To ensure ovarian cancer control and efficient detection, there is an urgent need for faster and less costly medical tools in the arena of oncology.

The placement of dental implants is performed in a contaminated surgical field in the oral cavity, which may lead to implant failure. Bacterial adhesion and proliferation ( , ) often lead to implant infections. Although Ag nanoparticles hold great promise for a broad spectrum of antibacterial activities, their runoff from dental implants compromises their antibacterial efficacy and potentially impairs osteoblast proliferation. Thus, this aspect remains a primary challenge and should be controlled. In this study, PLGA(Ag-Fe O ) was modified on the implanted tooth surface and was characterized by transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The magnetic and antibacterial properties were also determined. Results showed that Ag successfully bonded with Fe O , and Ag-Fe O not only exerted superparamagnetism but also exhibited antibacterial activity almost identical to silver nanoparticles (nano-Ag). The PLGA(Ag-Fe O ) coating could significantly maintain the antibacterial activity and avoid bacterial adhesion to the implant. Compared with the blank control group, PLGA(Ag-Fe O ) under magnetic field-coated samples had a significantly lower amount of colonized ( <0.01). Osteoblast proliferation results showed that the coated samples did not exhibit cytotoxicity and could promote osteoblast proliferation as shown by MTT, alkaline phosphatase, and the nucleolar organizer region count. We developed a novel Ag biologically compatible nanoparticle in this study without compromising the nano-Ag antibacterial activity, which provided continuous antibacterial action.

Background To observe the effect and mechanism of alpha-adrenergic receptor inhibitor phentolamine (PTL) in a rabbit model of acute pulmonary embolism (APE) combined with shock. Methods Twenty-four New Zealand rabbits were randomly divided into sham operation group (S group, n  = 8), model group (M group, n  = 8) and PTL group ( n  = 8), the model of APE combined with shock was established. Mean pulmonary arterial pressure (MPAP), peripheral mean arterial pressure (MAP) and pulmonary circulation time were evaluated. The expression levels of α 1 receptor, α 2 receptor and their downstream molecules in pulmonary embolism (PE) and non-pulmonary embolism (non-PE) regions lung tissues were detected and compared, respectively. Results In M group, α receptor-related signaling pathways were significantly activated in both PE and non-PE areas as expressed by up-regulated α 1 , α 2 receptor and phospholipase C (PLC); the expression level of phosphorylated protein kinase A (p-PKA) was significantly down-regulated; myosin light chain kinase (MLCK) and α-smooth muscle actin (α-SMA) levels were up-regulated. PTL treatment significantly improved pulmonary as well as systemic circulation failure: decreased MPAP, restored blood flow in non-PE area, shortened pulmonary circulation time, increased MAP, and restored the circulation failure. PTL induced significantly down-regulated expression of α 1 receptor and its downstream molecule PLC in both PE and non-PE area, the expression level of α 2 receptor was also down-regulated, the expression level of p-PKA was significantly up-regulated. PTL treatment can inhibit both α 1 and α 2 receptor-related signaling pathways in whole lung tissues, and inhibit Ca 2+ signaling pathways. The expression level of MLCK and α-SMA were significantly down-regulated. Compared with PE area, the changes of expression levels of α receptor and its downstream molecules were more significant in the non-PE region. Conclusion In this model of APE combined with shock, the sympathetic nerve activity was enhanced in the whole lung, α 1 and α 2 receptor and their downstream signaling activation might mediate blood flow failure in the whole lung. PTL treatment can effectively restore pulmonary blood flow in non-PE area and improve pulmonary as well as systemic circulation failure possibly through down-regulating α 1 and α 2 receptor and their downstream signaling pathways.

The clinical management of bone defects presents a significant challenge in regenerative medicine due to the limited self-repair capacity of bone tissue and inadequate vascularization. Nitric oxide, a gaseous signaling molecule, has garnered attention as a potent modulator of bone remodeling, exhibiting pro-osteogenic, pro-angiogenic, and anti-inflammatory properties. However, its therapeutic application is limited by its short half-life, high reactivity, and dose-dependent biphasic effects. Advanced polymer-based nanoformulations have been developed to address these challenges and enable controlled and localized NO delivery to bone tissue. This review explores role of NO in bone repair mechanisms and the limitations of conventional delivery systems. Significant focus is given to innovative polymeric platforms, such as dendrimers, micelles, nanogels, and hybrid composites, which offer precise control over release kinetics, high encapsulation efficiency, and targeted delivery. Additionally, integrating NO delivery within nanoengineered scaffolds and coatings for orthopedic implants is explored as a promising strategy to enhance osteointegration and reduce the risk of post-surgical infections. Preclinical studies demonstrate promising osteogenic effects yet face significant challenges including cytotoxicity at elevated NO concentrations along with non-standardized evaluation protocols and scalability limitations. Future perspectives point to the potential of stimuli-responsive systems, co-delivery approaches, and personalized strategies utilizing additive manufacturing technologies. This review consolidates the latest advancements in the field, underscoring the significant potential of polymer-based NO nanoformulations to revolutionize bone tissue engineering.