Imaging Thermally Fluctuating Néel Vectors in van der Waals Antiferromagnet NiPS3.

Studying antiferromagnetic domains is essential for fundamental physics and potential spintronics applications. Despite their importance, few systematic studies have been performed on antiferromagnet (AFM) domains with high spatial resolution in van der Waals (vdW) materials, and direct probing of the Néel vectors remains challenging. In this work, we found multidomain states in the vdW AFM NiPS3, a material extensively investigated for its unique magnetic exciton. We employed photoemission electron microscopy combined with the X-ray magnetic linear dichroism (XMLD-PEEM) to image the NiPS3's magnetic structure. The nanometer-spatial resolution of XMLD-PEEM allows us to determine local Néel vector orientations and discover thermally fluctuating Néel vectors that are independent of the crystal symmetry even at 65 K, well below the TN of 155 K. We demonstrate that an in-plane orbital moment of the Ni ion is responsible for the weak magnetocrystalline anisotropy. The observed thermal fluctuations of the antiferromagnetic domains may explain the broadening of magnetic exciton peaks at higher temperatures.

Improved eutrophication model with flow velocity-influence function and application for algal bloom control in a reservoir in East China.

Improving hydrodynamic conditions is considered an effective method for facilitating the eutrophication management. However, the effect of hydrodynamic conditions on algal growth has rarely been quantified. In this work, a eutrophication model was developed and flow velocity was introduced into the algae growth kinetic formula to simulate the dynamics of algae growth in a drinking water source reservoir in East China. Based on the previous research and model calibration, the flow velocity-influence function f(v) and its parameters were determined. Accordingly, the optimal flow velocity for the dominant algae growth and critical flow velocity for algal growth inhibition were presented to be 0.055 m/s and 0.200 m/s for the study reservoir. Modeled results considering f(v) agreed with better with observations and reproduced the algal overgrowth process more accurately. The spatial-temporal differences in chlorophyll a (Chl a) concentration distribution during the algal proliferation period were analyzed on the basis of simulation results, which corroborated the significant influence of flow velocity on algal growth. The established model was applied to investigate the effect of improvement in hydrodynamic conditions on algal bloom control in the reservoir, and the scenario simulation of the additional sluice was conducted. Results showed that the additional sluice operation inhibited algal overgrowth effectively, resulting in an average decrease of 24.8%, 3.3%, 43.0%, and 37.5% in modeled Chl a concentration upstream north, upstream south, midstream and downstream, respectively. The established model might serve as a practical tool for eutrophication management in the study reservoir and other water bodies with similar hydrological characteristics and geographical features.

Nervous System-Driven Osseointegration.

Implants are essential therapeutic tools for treating bone fractures and joint replacements. Despite the in-depth study of osseointegration for more than fifty years, poor osseointegration caused by aseptic loosening remains one of the leading causes of late implant failures. Osseointegration is a highly sophisticated and spatiotemporal process in vivo involving the immune response, angiogenesis, and osteogenesis. It has been unraveled that the nervous system plays a pivotal role in skeletal health via manipulating neurotrophins, neuropeptides, and nerve cells. Herein, the research related to nervous system-driven osseointegration was systematically analyzed and reviewed, aiming to demonstrate the prominent role of neuromodulation in osseointegration. Additionally, it is indicated that the implant design considering the role of neuromodulation might be a promising way to prevent aseptic loosening.

Differential Nanoscale Topography Dedicates Osteocyte-Manipulated Osteogenesis via Regulation of the TGF-ß Signaling Pathway.

Osteocytes function as the master orchestrator of bone remodeling activity in the telophase of osseointegration. However, most contemporary studies focus on the manipulation of osteoblast and/or osteoclast functionality via implant surface engineering, which neglects the pivotal role of osteocytes in de novo bone formation. It is confirmative that osteocyte processes extend directly to the implant surface, but whether the surface physicochemical properties can affect the functionality of osteocytes and determine the fate of the osseointegration in the final remodeling stage remains to be determined. Titania nanotube arrays (NTAs) with distinct diameters were fabricated to investigate the relationship between the nanoscale topography and the functionality of osteocytes. In vitro results pinpointed that NTA with a diameter of 15 nm (NTA-15) significantly promote osteogenesis of osteocytes via the enhancement of spreading, proliferation, and mineralization. The osteocyte transcriptome of each group further revealed that the TGF-ß signaling pathway plays a pivotal role in osteocyte-mediated osteogenesis. The in vivo study definitely mirrored the aforementioned results, that NTA-15 significantly promotes bone formation around the implant. Consequently, nanoscaled topography-induced osteocyte functionality is important in late osseointegration. This suggests that surface designs targeting osteocytes may, therefore, be a potential approach to solving the aseptic loosening of the implant, and thus strengthen osseointegration.

Broken Inversion Symmetry in Van Der Waals Topological Ferromagnetic Metal Iron Germanium Telluride.

Inversion symmetry breaking is critical for many quantum effects and fundamental for spin-orbit torque, which is crucial for next-generation spintronics. Recently, a novel type of gigantic intrinsic spin-orbit torque is established in the topological van der Waals (vdW) magnet iron germanium telluride. However, it remains a puzzle because no clear evidence exists for interlayer inversion symmetry breaking. Here, the definitive evidence of broken inversion symmetry in iron germanium telluride directly measured by the second harmonic generation (SHG) technique is reported. The data show that the crystal symmetry reduces from centrosymmetric P63/mmc to noncentrosymmetric polar P3m1 space group, giving the threefold SHG pattern with dominant out-of-plane polarization. Additionally, the SHG response evolves from an isotropic pattern to a sharp threefold symmetry upon increasing Fe deficiency, mainly due to the transition from random defects to ordered Fe vacancies. Such SHG response is robust against temperature, ensuring unaltered crystalline symmetries above and below the ferromagnetic transition temperature. These findings add crucial new information to the understanding of this interesting vdW metal, iron germanium telluride: band topology, intrinsic spin-orbit torque, and topological vdW polar metal states.

A suture-free, shape self-adaptive and bioactive PEG-Lysozyme implant for Corneal stroma defect repair and rapid vision restoration.

Corneal transplantation is a prevailing treatment to repair injured cornea and restore vision but faces the limitation of donor tissue shortage clinically. In addition, suturing-needed transplantation potentially causes postoperative complications. Herein, we design a PEG-Lysozyme injective hydrogel as a suture-free, shape self-adaptive, bioactive implant for corneal stroma defect repair. This implant experiences a sol-gel phase transition via an in situ amidation reaction between 4-arm-PEG-NHS and lysozyme. The physicochemical properties of PEG-Lysozyme can be tuned by the components ratio, which confers the implant mimetic corneal modulus and provides tissue adhesion to endure increased intraocular pressure. In vitro tests prove that the implant is beneficial to Human corneal epithelial cells growth and migration due to the bioactivity of lysozyme. Rabbit lamellar keratoplasty experiment demonstrates that the hydrogel can be filled into defect to form a shape-adaptive implant adhered to native stroma. The implant promotes epithelialization and stroma integrity, recovering the topology of injured cornea to normal. A newly established animal forging behavior test prove a rapid visual restoration of rabbits when use implant in a suture free manner. In general, this work provides a promising preclinical practice by applicating a self-curing, shape self-adaptive and bioactive PEG-Lysozyme implant for suture-free stroma repair.

The solvent effect modulates the formation of homogeneous polyphenol composite hydrogels with improved transparency and mechanical strength for antibacterial delayed sternal closure films.

The usage of delayed sternal closure films after thoracotomy surgery helps doctors deal with emergency conveniently. There is a growing demand to develop suturable, antibacterial and transparent films for delayed sternal closure. Although polyphenol incorporated hydrogels provide good suture ability, they lose transparency because of the heterogeneous distribution of polyphenols during the post-immersion process. Here, a solvent exchange method is proposed to fabricate homogeneous polyphenol composite hydrogels in a bottom-up manner, which utilizes the distinct solvent effect of DMSO and H2O to modulate the association and disassociation between polyphenols and the polymer backbones on demand. DMSO first provides a protective environment to turn off the intermolecular interactions and allows tannic acid (TA) to be dispersed into the polymer network PEG-lysozyme (PEG-LZM) homogeneously. The following water rehydration turns on the intermolecular interactions between titanic acid and PEG-lysozymes, and results in a homogeneous titanic acid toughened composite hydrogel (PEG-LZM-TA (DH)), which has an improved transparency and mechanical properties than those of the materials prepared by the post-immersion method. In addition, the TA integration provides antibacterial function to the hydrogels. We establish a rabbit delayed sternal closure model to demonstrate that PEG-LZM-TA (DH) films can be sutured to temporarily close the thoracic cavity of rabbits, provide a transparent window to inspect the wound at any time, and control the bacterial contamination efficiently. We further explore the solvent exchange method to other polyphenols and polymeric hydrogel composites. The results suggest that the solvent exchange method provides generic opportunities to fabricate homogeneous polyphenol strengthened hydrogel systems with high performance.

Eco-friendly development of an ultrasmall IONP-loaded nanoplatform for bimodal imaging-guided cancer theranostics.

Success in disease therapy depends on precision medicines, where development of formulations with diagnostic and therapeutic functions is quite important. In this study, multifunctional theranostics based on a magnetic graphene oxide (GO) nanohybrid (GIPD) has been developed for magnetic resonance (MR) imaging-guided chemo-photothermal therapy of cancer. The GIPD is endowed with T1/T2 MR imaging capacity via precipitation of small-sized IONP nanoparticles (8.25 ± 2.25 nm) on GO nanosheets through a mild friendly way (60 °C for 1 h, no organic solvent). The obtained nanocomposite is then non-covalently decorated with phosphine oxide polyethylene glycol to improve biosafety. The final nanohybrid effectively loads doxorubicin as the model chemotherapeutic drug and is found to have in vivo T1/T2 MR bimodal imaging functions. Both the in vitro and in vivo results demonstrate that the GO-based nanoplatform displays a good remote photothermal effect, which can damage the dense shell of solid tumor tissue, thereby facilitating the delivery of anticancer drugs into tumor cells. Therefore, this theranostic nanoplatform enables a potent combined chemo-photothermal anticancer efficacy, holding great potential for exploitation of precision cancer therapy.

[The significance of pepsinogen with its subgroup and CA72-4 associate detect applied to early diagnostic and prognosis judgment on gastric cancer].

OBJECTIVE: To find out the connection of serum pepsinogen and it's subgroups (PGI, PGII) with CA72-4 to early diagnosis and postoperative recurrence on gastric cancer. METHODS: RIA was applied to detect the results of serum PGI, PGII and CA72-4 on gastric cancer and other stomach diseases, then the clinic value of associating detection on gastric cancer diagnosis and prognosis judgment were assessed. RESULTS: The serum PG levels of GC patients were significantly lower comparing to those of healthy controls (P < 0.01), apparent changes had taken place on earlier period GC (P < 0.05), and aggressive GC were even lower (P < 0.01). On the earlier period of GC diagnosis, CA72-4 levels were not apparently different to healthy controls (P > 0.05), and aggressive GC were significantly higher (P < 0.01). Compared preoperative with postoperative, the serum PGI and PGII and CA72-4 levels were significantly different (P < 0.01). In the patients underwent total gastrectomy, both of pepsinogen levels were lower than those of subtotal or large partial gastrectomy (P < 0.05). The serum PGI, PGII and CA72-4 levels of patients with recurrence of GC after total gastrectomy were significantly higher than those without. Compared before recurrence patients with after ones, the serum PGI and PGII levels of partial gastrectomy were no apparent difference (P > 0.05), however apparent changes had taken place on CA72-4 levels. The associate detection had even higher specificity (P < 0.01). CONCLUSIONS: Apply to detect the serum PG levels on crowds, especially pGI, PGI/II levels decrease, which may be expected to become the index to earlier period GC screening. The associating detection to PG and CA72-4 levels may significantly improve sensitivity and specificity, which have chances to be applied to monitoring to postoperative gastrectomy.