A photothermal responsive system accelerating nitric oxide release to enhance bone repair by promoting osteogenesis and angiogenesis

Managing bone defects remains a formidable clinical hurdle, primarily attributed to the inadequate orchestration of vascular reconstruction and osteogenic differentiation in both spatial and temporal dimensions. This challenge persists due to the constrained availability of autogenous grafts and the limited regenerative capacity of allogeneic or synthetic bone substitutes, thus necessitating continual exploration and innovation in the realm of functional and bioactive bone graft materials. While synthetic scaffolds have emerged as promising carriers for bone grafts, their efficacy is curtailed by deficiencies in vascularization and osteoinductive potential. Nitric oxide (NO) plays a key role in revascularization and bone tissue regeneration, yet studies related to the use of NO for the treatment of bone defects remain scarce. Herein, we present a pioneering approach leveraging a photothermal-responsive system to augment NO release. This system comprises macromolecular mPEG-P nanoparticles encapsulating indocyanine green (ICG) (NO-NPs@ICG) and a mPEG-PA-PP injectable thermosensitive hydrogel carrier. By harnessing the synergistic photothermal effects of near-infrared radiation and ICG, the system achieves sustained NO release, thereby activating the soluble guanylate cyclase (SGC)-cyclic guanosine monophosphate (cGMP) signaling pathway both in vitro and in vivo. This orchestrated cascade culminates in the facilitation of angiogenesis and osteogenesis, thus expediting the reparative processes in bone defects. In a nutshell, the NO release-responsive system elucidated in this study presents a pioneering avenue for refining the bone tissue microenvironment and fostering enhanced bone regeneration.

A synthetic moving-envelope metasurface antenna for independent control of arbitrary harmonic orders

Flexible frequency controls are crucial in many photonic and electronic applications, ranging from communications systems, spectroscopy, and metrology to quantum information processing. However, the state-of-the-art solutions based on nonlinear bulk media, electro-optic effect, and nonlinear metasurfaces incur very limited spectral controllability, and merely a couple of harmonic orders can be independently manipulated. Here, we theoretically propose and experimentally demonstrate synthetic moving-envelope metasurface antennas capable of simultaneously generating arbitrary harmonic orders and independently manipulating their wave properties in a software-defined manner. As proof-of-principle examples, we demonstrate unidirectional frequency transition, frequency comb generation, arbitrary harmonic orders independent control, and their applications in frequency-division multiplexing communications. All these complicated functionalities are achieved by the 1-bit spatiotemporally ON-OFF switching of meta-atoms of the waveguide-integrated metasurface antenna. Our proposed synthetic metasurface antenna solution greatly expands the frontiers of wave engineering and information manipulation, showing promising potential in wireless communications, spectroscopy, metrology, and quantum science.

Research on High-Precision Measurement Method for Small-Size Gears with Small-Modulus

Small-modulus gears, which are essential for motion transmission in precision instruments, present a measurement challenge due to their minuscule gear gaps. A high-precision measurement method under the influence of positioning errors is proposed, enabling precise evaluation of the machining quality of small-modulus gears. Firstly, a compound measurement platform for small-modulus gears is developed. Using a 3D model of the measurement system, the mathematical relationships governing motion transmission between various components are analyzed. Secondly, the formation mechanism of gear positioning error is revealed and its important influence on measurement accuracy is discussed. An optimization method for spatial coordinate transformation matrices under positioning errors of gears is proposed. Thirdly, the study focuses on small-sized gears with a modulus of 0.1 mm and a six-level accuracy. Based on the aforementioned measurement system, the tooth profile measurement points are collected in the actual workpiece coordinate system. Then, gear error parameters are extracted based on the established models for tooth profile deviation and pitch deviation. Finally, the accuracy and effectiveness of the proposed measurement method are verified by comparing the measurement results of the P26 gear measuring center.

Dual-Energy Computed Tomography Iodine Maps: Application in the Diagnosis of Periprosthetic Joint Infection in Total Hip Arthroplasty

BACKGROUND

The challenge of early and rapid diagnosis of periprosthetic joint infection (PJI) remains important. This study aimed to assess the efficacy of dual-energy computed tomography (CT) (DECT) iodine maps for diagnosing PJI in total hip arthroplasty.

METHODS

We prospectively enrolled 68 patients who had postoperative joint pain after hip arthroplasty. All patients underwent preoperative DECT iodine imaging to quantify iodine concentration (IC) in periprosthetic tissues during arterial and venous phases. The diagnostic efficacy of DECT iodine maps was evaluated by constructing receiver operating characteristic (ROC) curves according to the Musculoskeletal Infection Society criteria.

RESULTS

Compared with erythrocyte sedimentation rate (Area Under the Curve (AUC) = 0.837), polymorphonuclear cell percentage (AUC = 0.703), and C-reactive protein (AUC = 0.837), periprosthetic tissue venous-phase iodine concentration (IC) (AUC = 0.970) and arterial-phase IC (AUC = 0.964) exhibited outstanding discriminative capability between PJI and aseptic failure. The PJI cut-off point was venous IC = 1.225 mg/ml, with a sensitivity of 92.31% and specificity of 90.48%; for arterial IC = 1.065 mg/ml, the sensitivity was 96.15%, and a specificity was 90.70%.

CONCLUSION

This study demonstrates the great potential of DECT iodine maps for the diagnosis of PJI around hip arthroplasty, which helps to differentiate between periprosthetic infection and aseptic failure after hip arthroplasty.

Lattice distortion enabling enhanced strength and plasticity in high entropy intermetallic alloy

Intermetallic alloys have traditionally been characterized by their inherent brittleness due to their lack of sufficient slip systems and absence of strain hardening. However, here we developed a single-phase B2 high-entropy intermetallic alloy that is both strong and plastic. Unlike conventional intermetallics, this high-entropy alloy features a highly distorted crystalline lattice with complex chemical order, leading to multiple slip systems and high flow stress. In addition, the alloy exhibits a dynamic hardening mechanism triggered by dislocation gliding that preserves its strength across a wide range of temperatures. As a result, this high-entropy intermetallic circumvents precipitous thermal softening, with extensive plastic flows even at high homologous temperatures, outperforming a variety of both body-centered cubic and B2 alloys. These findings reveal a promising direction for the development of intermetallic alloys with broad engineering applications.

By Introducing Multiple Hydrogen Bonds Endows MOF Electrodes with an Enhanced Structural Stability

Recently, metal-organic frameworks (MOFs) have attracted great interest in energy storage areas. However, the poor structural stability of MOFs derived from weak coordination bonds limits their applications. Here, quadruple hydrogen bonds (H-bonds) were introduced onto the MOFs to enhance their structural stability. Cross-linked networks could be formed between molecules owing to multiple H-bonds, strengthening the framework stability. Moreover, the dynamic reversibility of H-bonds could endow MOFs with self-healing ability. Furthermore, due to lower binding energy compared to coordination bonds, H-bonds break preferentially when subjected to internal stress, thus protecting the MOFs. Consequently, the as-prepared self-healing hybrid (SHH-Cu-MOF@Ti3C2TX) exhibited high capacitance retention (89.4%) after 5000 cycles at 1 A g-1, while that hybrid without dynamic H-bonds (H-Cu-MOF@Ti3C2TX) presented a 79.9% retention, delivering an enhancement in cycling stability. Moreover, an asymmetric supercapacitor (ASC) was fabricated by employing SHH-Cu-MOF@Ti3C2TX and activated carbon (AC) as the electrodes. The ASC delivered a specific capacitance (47.4 F g-1 at 1 A g-1), an energy density (16.9 Wh kg-1), and a power density (800 W kg-1) as well as good rate ability (retains 81% of its initial capacitance from 0.2 A g-1 to 5 A g-1).

A Dual-Polarization Programmable Metasurface for Green and Secure Wireless Communication

Dual-polarization programmable metasurfaces can flexibly manipulate electromagnetic (EM) waves while providing approximately twice the information capacity. Therefore, they hold significant applications in next-generation communication systems. However, there are three challenges associated with the existing dual-polarization programmable metasurfaces. This article aims to propose a novel design to address them. First, the design overcomes the challenge of element- and polarization-independent controls, enabling more powerful manipulations of EM waves. Second, by using more energy-efficient tunable components and reducing their number, the design can be nearly passive (maximum power consumption of 27.7 mW), leading to a significant decrease in the cost and power consumption of the system (at least two orders of magnitude lower than the power consumption of conventional programmable metasurfaces). Third, the design can operate in a broad bandwidth, which is attractive for practical engineering applications. Both the element and array of the metasurface are meticulously designed, and their performance has been carefully studied. The experiments demonstrate that 2D wide-angle beam scanning can be realized. Moreover, secure communication based on directional information modulation can be implemented by exploiting the metasurface and an efficient discrete optimization algorithm, showing its programmable, multiplexing, broadband, green, and secure features.

Effect of oregano essential oil on intestinal immunoglobulin G in Holstein dairy bulls

Introduction

Immunoglobulin G (IgG) is important in mediating humoral immunity and in the maintenance of immune homeostasis in the intestinal mucosa. Oregano essential oil (OEO) is a natural herbal extract that possesses antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory properties. As the effects of OEO on intestinal mucosal immunity in Holstein dairy bulls remained unclear, we investigated the effect of dietary supplementation of OEO on IgG levels and IgG+ cells residing in the intestinal tract in Holstein dairy bulls.

Methods

Twelve Holstein bulls in good health of approximately 10 months of age were selected for the experiment and randomly equally divided into two groups. The control (CK) group was fed a basal ration, and in the OEO group, the basal ration was supplemented with OEO (20 g/head/day). After 300 days of feeding, tissue samples of the jejunum, ileum, and colon of the bulls in each group were collected for histopathological analysis, immunohistochemistry, and enzyme-linked immunosorbent assays, respectively.

Results

The jejunum, ileum, and colon of bulls in the CK group had obvious pathological damage, whereas the structure of each intestinal segment was clear and intact. In the OEO group, pathological damage was significantly reduced. IgG+ plasma cells were diffusely distributed in the lamina propria of the jejunum, ileum, and colon in the CK and OEO groups, with no significant difference between the groups. OEO supplementation significantly reduced the number of IgG+ plasma cells in each intestinal segment, with the highest decrease rate being noted for the ileum (22.87%), followed by the colon (19.45%) and jejunum (8.52%). ELISA test results and immunohistochemical results were mutually verified. The change in IgG content was consistent with the trend of change in the number of IgG+ plasma cells.

Discussion

Our findings suggest that OEO supplementation does not alter the diffuse spatial distribution of IgG+ plasma cells in the intestines of Holstein dairy bulls, but lowers immunoglobulin levels to normal levels, significantly reduces intestinal damage, and may enhance mucosal immune defence barrier function by inhibiting inflammatory reactions.

[Effect of preoperative oral ibuprofen on postoperative pain after dental implantation: a randomized controlled trial]

Objective: To evaluate the effect of preemptive analgesia with ibuprofen on postoperative pain following single posterior tooth implantation, aiming to provide a clinical reference for its application. Methods: A multicenter, randomized, double-blind, placebo-controlled parallel-group trial was conducted. A total of 82 participants were included in the trial, meeting the eligibility criteria from April 2022 to April 2024 at the Capital Medical University School of Stomatology (40 cases), Beijing TianTan Hospital, Capital Medical University (22 cases), Beijing Chao-Yang Hospital, Capital Medical University (20 cases). Participants were randomly assigned in a 1∶1 ratio to either the ibuprofen group or the control group, with each group comprising 41 individuals. Participants in the ibuprofen group received 300 mg of sustained-release ibuprofen capsules orally 15 min before surgery, while the control group received a placebo. Both groups received the same postoperative analgesic regimen for 3 days. Pain scores were assessed using the Numerical rating scale (NRS) at 30 min, 4 h, 6 h, 8 h, 24 h, 48 h, and 72 h postoperatively, and the additional use of analgesic medication was recorded from days 4 to 6 postoperatively. Results: A total of 82 participants were initially enrolled in the study, with 7 dropouts (4 from the control group and 3 from the ibuprofen group), resulting in 75 participants (37 in the control group and 38 in the ibuprofen group) completing the trial. There were no reports of adverse events such as nausea or vomiting among the participants. The ibuprofen group exhibited significantly lower pain scores at 4 h, 6 h and 8 h [1.0 (0.0, 2.0), 1.0 (0.0, 2.0), 1.5 (0.0, 3.0) ] postoperatively compared to the control group 4 h, 6 h and 8 h [2.0 (1.0, 3.0), 3.0 (1.5, 4.0), 2.0 (1.0, 4.0)] (Z=-1.99, P=0.047; Z=-3.01, P=0.003; Z=2.10, P=0.036). The proportions of patients requiring additional analgesic medication between days 4 and 6 post-surgery were 18.4% (7/38) in the ibuprofen group and 27.0% (10/37) in the control group, with no significant difference (χ2=0.79, P=0.373). The median additional medication usage postoperatively was [0.0 (0.0, 0.0) pills] in the ibuprofen group and [0.0 (0.0, 1.0) pills] in the control group, with no significant difference (Z=-0.78, P=0.439). Conclusions: Preemptive analgesia with ibuprofen effectively reduces postoperative pain following tooth implantation, representing a safe and effective perioperative pain management strategy.

Arbitrarily rotating polarization direction and manipulating phases in linear and nonlinear ways using programmable metasurface

Independent controls of various properties of electromagnetic (EM) waves are crucially required in a wide range of applications. Programmable metasurface is a promising candidate to provide an advanced platform for manipulating EM waves. Here, we propose an approach that can arbitrarily control the polarization direction and phases of reflected waves in linear and nonlinear ways using a stacked programmable metasurface. Further, we extend the space-time-coding theory to incorporate the dimension of polarization, which provides an extra degree of freedom for manipulating EM waves. As proof-of-principle application examples, we consider polarization rotation, phase manipulation, and beam steering at linear and nonlinear frequencies. For validation, we design, fabricate, and measure a metasurface sample. The experimental results show good agreement with theoretical predictions and simulations. The proposed approach has a wide range of applications in various areas, such as imaging, data storage, and wireless communication.

Tunable Near-Field Radiative Heat Transfer between Graphene-Coated Magneto-Optical Metasurfaces

The highly structured design of metasurfaces greatly facilitates the manipulation of near-field radiative heat transfer (NFRHT). In this study, we incorporate magneto-optical materials into metasurfaces to theoretically explore the mechanism for controlling NFRHT between anisotropic magneto-optical metasurfaces. Our findings indicate that the interaction between the magnetization-induced modes, arising from interband transitions of graphene, and the surface modes of InSb under a magnetic field leads to a transition in the heat transfer spectrum from a dual band to a triple band. The modification of the distribution and magnitude of transmission wave vectors in surface electromagnetic modes by magnetic fields serves to modulate the radiative heat flux. By combining active control by a magnetic field with passive structural design of metasurfaces, the regulation of heat flux can be increased by more than 8-fold compared with the planar configuration. Additionally, the magnetic field amplifies the anisotropy of the photon energy distribution induced by the symmetry breaking of the metasurface structure. This study is anticipated to provide a pathway for achieving flexible tuning of NFRHT by combining active and passive regulation. It also opens up possibilities for multiband information transmission and for improving the performance of energy conversion devices.

[Change Characteristics of Carbonaceous Aerosol in Chengdu from 2018 to 2021]

Carbonaceous aerosol is an important component of atmospheric fine particulates （PM2.5） that has an important effect on global climate change, atmospheric visibility, regional air quality, and human health. In order to investigate the long-term change characteristics of carbonaceous aerosols under the background of emission reduction, the concentrations of organic carbon （OC）, elemental carbon （EC） in PM2.5 samples, and volatile organic compounds （VOCs） in Chengdu from 2018 to 2021 and the corresponding meteorological factors were obtained through real-time online monitoring. The results showed that the average ρ（OC） and ρ（EC） during the monitoring period were （10.9 ±5.7） μg·m-3 and （2.6 ±1.9） μg·m-3, accounting for 25.2% and 6.0% of PM2.5, respectively, and the average ρ（SOC） was （5.7 ±3.3） μg·m-3, accounting for 52.9% of OC. The concentrations of OC, EC, and PM2.5 showed a downward trend from 2018 to 2020 [PM2.5： The concentration of average annual decrease was -7.1 μg·（m3·a） -1, with an average annual decrease of -14.6 %·a-1； OC： -1.7 μg·（m3·a）-1, -14.2 %·a-1； EC： -0.1 μg·（m3·a）-1, -4.4 %·a-1], and the concentrations of each pollutant in 2021 rebounded in different ranges compared with those in 2020. The concentrations of PM2.5 and OC were as follows： winter > spring > autumn > summer, and the concentrations of EC were as follows： winter > autumn > spring > summer. The proportions of OC and EC were higher in summer and autumn than in other seasons, with the average proportions of 26.8% and 6.9%, respectively. With the aggravation of the pollution level, OC, EC, and SOC concentrations gradually increased, but the proportions in PM2.5 showed a gradual downtrend, indicating that the control factor of PM2.5 pollution in Chengdu was not the carbon component. Source apportionment results showed that carbonaceous aerosols in Chengdu were mainly affected by motor vehicles, industrial sources, biomass combustion sources, and VOCs secondary reaction. From 2019 to 2021, EC was affected by the characteristic components of motor vehicles and decreased yearly. OC and EC were affected by VOCs more in spring and autumn than in other seasons. VOCs emission management should be increased in spring and autumn to reduce the impact of secondary reaction.

Fully Breaking Entanglement of Multiple Harmonics for Space- and Frequency-Division Multiplexing Wireless Applications via Space-Time-Coding Metasurface

Harmonic generation and utilization are significant topics in nonlinear science. Although the progress in the microwave region has been expedited by the development of time-modulated metasurfaces, one major issue of these devices is the strong entanglement of multiple harmonics, leading to criticism of their use in frequency-division multiplexing (FDM) applications. Previous studies have attempted to overcome this limitation, but they suffer from designing complexity or insufficient controlling capability. Here a new space-time-coding metasurface (STCM) is proposed to independently and precisely synthesize not only the phases but also the amplitudes of various harmonics. This promising feature is successfully demonstrated in wireless space- and frequency-division multiplexing experiments, where modulated and unmodulated signals are simultaneously transmitted via different harmonics using a shared STCM. To illustrate the advantages, binary frequency shift keying (BFSK) and quadrature phase shift keying (QPSK) modulation schemes are respectively implemented. Behind the intriguing functionality, the mechanism of the space-time coding strategy and the analytical designing method are elaborated, which are validated numerically and experimentally. It is believed that the achievements can potentially propel the time-vary metasurfaces in the next-generation wireless applications.

Pleiotropic effects of nitric oxide sustained-release system for peripheral nerve repair

The regenerative microenvironment after peripheral nerve injury is imbalanced and difficult to rebalance, which is mainly affected by inflammation, oxidative stress, and inadequate blood supply. The difficulty in remodeling the nerve regeneration microenvironment is the main reason for slow nerve regeneration. Traditional drug treatments have certain limitations, such as difficulty in penetrating the blood-nerve barrier and lack of pleiotropic effects. Therefore, there is an urgent need to build multifunctional nerve grafts that can effectively regulate the regenerative microenvironment and promote nerve regeneration. Nitric oxide (NO), a highly effective gas transmitter with diatomic radicals, is an important regulator of axonal growth and migration, synaptic plasticity, proliferation of neural precursor cells, and neuronal survival. Moreover, NO provides potential anti-inflammation, anti-oxidation, and blood vessel promotion applications. However, excess NO may cause cell death and neuroinflammatory cell damage. The prerequisite for NO treatment of peripheral nerve injury is that it is gradually released over time. In this study, we constructed an injectable NO slow-release system with two main components, including macromolecular NO donor nanoparticles (mPEG-P(MSNO-EG) nanoparticles, NO-NPs) and a carrier for the nanoparticles, mPEG-PA-PP injectable temperature-sensitive hydrogel. Due to the multiple physiological regulation of NO and better physiological barrier penetration, the conduit effectively regulates the inflammatory response and oxidative stress of damaged peripheral nerves, promotes nerve vascularization, and nerve regeneration and docking, accelerating the nerve regeneration process. STATEMENT OF SIGNIFICANCE: The slow regeneration speed of peripheral nerves is mainly due to the destruction of the regeneration microenvironment. Neural conduits with drug delivery capabilities have the potential to improve the microenvironment of nerve regeneration. However, traditional drugs are hindered by the blood nerve barrier and cannot effectively target the injured area. NO, an endogenous gas signaling molecule, can freely cross the blood nerve barrier and act on target cells. However, excessive NO can lead to cell apoptosis. In this study, a NO sustained-release system was constructed to regulate the microenvironment of nerve regeneration through various pathways and promote nerve regeneration.

[The effect of ubiquitin ligase Cullin3 on the proliferation, migration and invasion of triple-negative breast cancer cells and exploration of its mechanism]

Objective: To investigate the effects of ubiquitin ligase Cullin3 (CUL3) on the proliferation, migration and invasion ability of triple-negative breast cancer (TNBC) cells and its mechanism of action. Methods: Bioinformatics-based methods were used to obtain CUL3 gene and protein expression data in TNBC tissues, and to assess the expression of CUL3 in tumour tissues of TNBC patients (n=160) and in normal breast tissues (n=572), and its relationship with clinical prognosis. The effects of overexpression of CUL3 on the proliferation, migration and invasion ability of TNBC cells in vitro were detected by CCK8 cell proliferation assay, scratch assay and transwell assay; proteins that might interact with CUL3 were screened by immunoprecipitation combined with mass spectrometry analysis, and the substrate protein regulated by CUL3 was identified as Glutathione S-Transferase Pi 1 (GSTP1); the effects of overexpression of GSTP1 on the migration and invasion ability of TNBC cells were detected by scratch assay and Transwell assay, and it was explored whether overexpression of CUL3 could reverse the effects of GSTP1 on the migration and invasion ability of cells; and the effects of overexpression of GSTP1 on the migration and invasion ability of cells were detected by Western blot and IP (Immunoprecipitation) to detect the effect of CUL3 on the ubiquitination modification of GSTP1 protein, and to verify the molecular mechanism by which CUL3 regulates the expression of GSTP1 to affect TNBC migration and invasion. Results: CUL3 expression was significantly higher in TNBC (P<0.000 1), and high CUL3 expression was closely associated with poor prognosis of TNBC patients (OS, P=0.018; RFS, P=0.008); overexpression of CUL3 significantly increased the proliferation of TNBC cells (F=11.97, P=0.002 for the 231-cell group, F=51.92, P<0.001 for the 468-cell group), migration [74.7±4.0 and 128.0±6.1 perforating cells in the overexpression groups of 231 and 468 cell lines, compared with 21.0±2.7 and 70.0±6.6 in the blank control (NC) group, and the t-values of 231 and 468 cell groups were-19.24 and-11.23, with P-values<0.001] and invasive ability (48 h cell proliferation rates were 56.6%±4.4% and 51.6%±3.7% in the 231 and 468 cell line overexpression groups, compared with 40.5%±2.9% and 32.9%±4.8% in the NC group, respectively, t=-5.26, P=0.006 3 in the 231 cell group; t=-5.38 in the 468 cell group, P=0.005 8); GSTP1 expression was reduced in TNBC, and up-regulation of GSTP1 inhibited TNBC cell migration (the number of membrane-penetrating cells in the overexpression groups of 231 and 468 cell lines were 16.3±6.5 and 33.0±6.2, respectively, compared with 34.3±2.5 and 77.3±5.0 in the NC group, and t=5.44 in the 231 cell group, P=0.006; 468 cell group t=7.20, P=0.002) and invasion (48 h cell proliferation rates of 49.6%±1.7% and 36.2%±1.4% in the 231 and 468 cell line overexpression groups, compared to 59.4%±4.7% and 53.0%±1.7% in the NC group, t=3.42, P=0.027 in the 231 cell group; 468 cell group t=13.18, P<0.001), whereas up-regulation of CUL3 reversed the effects of GSTP1 on cell migration (37.0±1.0 and 67.0±5.3 membrane-penetrating cells in the overexpression groups of 231 and 468 cell lines, respectively, 231 cell group t=-3.97, P=0.017; 468 cell group t=-6.12, P=0.004), and invasion (48 h cell proliferation rates of 71.9%±3.6% and 59.4%±2.1% in the 231 and 468 cell line overexpression groups, respectively, with t-values of -9.61 and -16.01 in the 231 and 468 cell groups, respectively, P-values<0.001) inhibitory effects; and CUL3, by increasing GSTP1 ubiquitylation modification, promotes ubiquitin-proteasome system to degrade GSTP1 protein, thereby reducing the stability of GSTP1 protein. Conclusion: Overexpression of CUL3 promotes TNBC development by promoting GSTP1 ubiquitination degradation inducing cell migration and invasion.

A filtering reconfigurable intelligent surface for interference-free wireless communications

The powerful capability of reconfigurable intelligent surfaces (RISs) in tailoring electromagnetic waves and fields has put them under the spotlight in wireless communications. However, the current designs are criticized due to their poor frequency selectivity, which hinders their applications in real-world scenarios where the spectrum is becoming increasingly congested. Here we propose a filtering RIS to feature sharp frequency-selecting and 2-bit phase-shifting properties. It permits the signals in a narrow bandwidth to transmit but rejects the out-of-band ones; meanwhile, the phase of the transmitted signals can be digitally controlled, enabling flexible manipulations of signal propagations. A prototype is designed, fabricated, and measured, and its high quality factor and phase-shifting characteristics are validated by scattering parameters and beam-steering phenomena. Further, we conduct a wireless communication experiment to illustrate the intriguing functions of the RIS. The filtering behavior enables the RIS to perform wireless signal manipulations with anti-interference ability, thus showing big potential to advance the development of next-generation wireless communications.

Quercetin-3-O-glc-1-3-rham-1-6-glucoside decreases Aβ production, inhibits Aβ aggregation and neurotoxicity, and prohibits the production of inflammatory cytokines

Alzheimer's disease (AD) is a progressive neurodegenerative disease with the hallmark of aggregation of beta-amyloid (Aβ) into extracellular fibrillar deposition. Accumulating evidence suggests that soluble toxic Aβ oligomers exert diverse roles in neuronal cell death, oxidative stress, neuroinflammation, and the eventual pathogenesis of AD. Aβ is derived from the sequential cleavage of amyloid-β precursor protein (APP) by β-secretase (BACE1) and γ-secretase. The current effect of single targeting is not ideal for the treatment of AD. Therefore, developing multipotent agents with multiple properties, including anti-Aβ generation and anti-Aβ aggregation, is attracting more attention for AD treatment. Previous studies indicated that Quercetin was able to attenuate the effects of several pathogenetic factors in AD. Here, we showed that naturally synthesized Quercetin-3-O-glc-1-3-rham-1-6-glucoside (YCC31) could inhibit Aβ production by reducing β-secretase activity. Further investigations indicated that YCC31 could suppress toxic Aβ oligomer formation by directly binding to Aβ. Moreover, YCC31 could attenuate Aβ-mediated neuronal death, ROS and NO production, and pro-inflammatory cytokines release. Taken together, YCC31 targeting multiple pathogenetic factors deserves further investigation for drug development of AD.

Radar Micro-Doppler Signature Generation Based on Time-Domain Digital Coding Metasurface

Micro-Doppler effect is a vital feature of a target that reflects its oscillatory motions apart from bulk motion and provides an important evidence for target recognition with radars. However, establishing the micro-Doppler database poses a great challenge, since plenty of experiments are required to get the micro-Doppler signatures of different targets for the purpose of analyses and interpretations with radars, which are dramatically limited by high cost and time-consuming. Aiming to overcome these limits, a low-cost and powerful simulation platform of the micro-Doppler effects is proposed based on time-domain digital coding metasurface (TDCM). Owing to the outstanding capabilities of TDCM in generating and manipulating nonlinear harmonics during wave-matter interactions, it enables to supply rich and high-precision electromagnetic signals with multiple micro-Doppler frequencies to describe the micro-motions of different objects, which are especially favored for the training of artificial intelligence algorithms in automatic target recognition and benefit a host of applications like imaging and biosensing.

Fine-Grained Essential Tensor Learning for Robust Multi-View Spectral Clustering

Multi-view subspace clustering (MVSC) has drawn significant attention in recent study. In this paper, we propose a novel approach to MVSC. First, the new method is capable of preserving high-order neighbor information of the data, which provides essential and complicated underlying relationships of the data that is not straightforwardly preserved by the first-order neighbors. Second, we design log-based nonconvex approximations to both tensor rank and tensor sparsity, which are effective and more accurate than the convex approximations. For the associated shrinkage problems, we provide elegant theoretical results for the closed-form solutions, for which the convergence is guaranteed by theoretical analysis. Moreover, the new approximations have some interesting properties of shrinkage effects, which are guaranteed by elegant theoretical results. Extensive experimental results confirm the effectiveness of the proposed method.

Skeletal editing of pyridines through atom-pair swap from CN to CC

Skeletal editing is a straightforward synthetic strategy for precise substitution or rearrangement of atoms in core ring structures of complex molecules; it enables quick diversification of compounds that is not possible by applying peripheral editing strategies. Previously reported skeletal editing of common arenes mainly relies on carbene- or nitrene-type insertion reactions or rearrangements. Although powerful, efficient and applicable to late-stage heteroarene core structure modification, these strategies cannot be used for skeletal editing of pyridines. Here we report the direct skeletal editing of pyridines through atom-pair swap from CN to CC to generate benzenes and naphthalenes in a modular fashion. Specifically, we use sequential dearomatization, cycloaddition and rearomatizing retrocycloaddition reactions in a one-pot sequence to transform the parent pyridines into benzenes and naphthalenes bearing diversified substituents at specific sites, as defined by the cycloaddition reaction components. Applications to late-stage skeletal diversification of pyridine cores in several drugs are demonstrated.

Castration alters the ileum microbiota of Holstein bulls and promotes beef flavor compounds

BACKGROUND

In the beef industry, bull calves are usually castrated to improve flavor and meat quality; however, this can reduce their growth and slaughter performance. The gut microbiota is known to exert a significant influence on growth and slaughter performance. However, there is a paucity of research investigating the impact of castration on gut microbiota composition and its subsequent effects on slaughter performance and meat flavor.

RESULT

The objective of this study was to examine the processes via which castration hinders slaughter productivity and enhances meat quality. Bull and castrated calves were maintained under the same management conditions, and at slaughter, meat quality was assessed, and ileum and epithelial tissue samples were obtained. The research employed metagenomic sequencing and non-targeted metabolomics techniques to investigate the makeup of the microbiota and identify differential metabolites. The findings of this study revealed the Carcass weight and eye muscle area /carcass weight in the bull group were significantly higher than those in the steer group. There were no significant differences in the length, width, and crypt depth of the ileum villi between the two groups. A total of 53 flavor compounds were identified in the two groups of beef, of which 16 were significantly higher in the steer group than in the bull group, and 5 were significantly higher in the bull group than in the steer group. In addition, bacteria, Eukaryota, and virus species were significantly separated between the two groups. The lipid metabolism pathways of α-linolenic acid, linoleic acid, and unsaturated fatty acids were significantly enriched in the Steers group. Compared with the steer group, the organic system pathway is significantly enriched in the bull group. The study also found that five metabolites (LPC (0:0/20:3), LPC (20:3/0:0), LPE (0:0/22:5), LPE (22:5/0:0), D-Mannosamine), and three species (s_Cloning_vector_Hsp70_LexA-HP1, s_Bacteroides_Coprophilus_CAG: 333, and s_Clostridium_nexile-CAG: 348) interfere with each other and collectively have a positive impact on the flavor compounds of beef.

CONCLUSIONS

These findings provide a basic understanding that under the same management conditions, castration does indeed reduce the slaughter performance of bulls and improve the flavor of beef. Microorganisms and metabolites contribute to these changes through interactions.

Design of a Compact 2-6 GHz High-Efficiency and High-Gain GaN Power Amplifier

In this paper, a novel wideband power amplifier (PA) operating in the 2-6 GHz frequency range is presented. The proposed PA design utilizes a combination technique consisting of a distributed equalization technique, multiplexing the power supply network and matching network technique, an LR dissipative structure, and an RC stability network technique to achieve significant bandwidth while maintaining superior gain flatness, high efficiency, high gain, and compact size. For verification, a three-stage PA using the combination technique is designed and implemented in a 0.25 μm GaN high-electron-mobility transistor (HEMT) process. The fabricated prototype demonstrates a saturated output power of 4 W, a power gain of 21 dB, a gain flatness of ±0.6 dB, a power-added efficiency of 39-46%, and a fractional bandwidth of 100% under the operating conditions of drain voltage 28 V (continuous wave) and gate voltage -2.6 V. Moreover, the chip occupies a compact size of only 2.51 mm × 1.97 mm.

New Method for Determining Mode-I Static Fracture Toughness of Coal Using Particles

Understanding the mechanical properties of coal is crucial for efficient mining and disaster prevention in coal mines. Coal contains numerous cracks and fissures, resulting in low strength and challenges in preparing standard samples for testing coal fracture toughness. In engineering, indicators such as the hardness coefficient (f value) and Hardgrove grindability index (HGI) are straightforward to measure. Various experiments, including drop weight, grinding, uniaxial compressive strength and three-point bending experiments, were conducted using notched semi-circular bend (NSCB) specimens and particle sizes of 1-2 mm/0.425-1 mm. Theoretical and experimental results indicate that the hardness coefficient of coal and rock is proportional to the crushing work ratio and inversely proportional to the mean equivalent diameter. Moreover, the square of the fracture toughness of coal and rock is directly proportional to the crushing work ratio, inversely proportional to the newly added area, directly proportional to the mean equivalent diameter and directly proportional to the hardness coefficient. The Mode-I fracture toughness of coal and rock can be rapidly determined through the density, the equivalent diameter after crushing and the elastic modulus, with experimental verification of its accuracy. Considering that smaller particle sizes exhibit greater resistance to breakage, the distribution mode of new surface areas after particle breakage was established, influenced by the initial particle size and the energy of a single broken particle. This study can assist in quickly and accurately determining the fracture toughness of coal.

A terahertz meta-sensor array for 2D strain mapping

Large-scale stretchable strain sensor arrays capable of mapping two-dimensional strain distributions have gained interest for applications as wearable devices and relating to the Internet of Things. However, existing strain sensor arrays are usually unable to achieve accurate directional recognition and experience a trade-off between high sensing resolution and large area detection. Here, based on classical Mie resonance, we report a flexible meta-sensor array that can detect the in-plane direction and magnitude of preloaded strains by referencing a dynamically transmitted terahertz (THz) signal. By building a one-to-one correspondence between the intrinsic electrical/magnetic dipole resonance frequency and the horizontal/perpendicular tension level, arbitrary strain information across the meta-sensor array is accurately detected and quantified using a THz scanning setup. Particularly, with a simple preparation process of micro template-assisted assembly, this meta-sensor array offers ultrahigh sensor density (~11.1 cm-2) and has been seamlessly extended to a record-breaking size (110 × 130 mm2), demonstrating its promise in real-life applications.

[Etiological characterization of invasive non-typhoid Salmonella strains in Guangdong Province from 2018 to 2022]

Objective: To understand the serotype distribution, drug resistance and molecular characterization of invasive non-typhoid Salmonella (iNTS) in Guangdong Province from 2018 to 2022 and provide scientific evidence for the prevention and treatment of blood flow infection caused by Salmonella. Methods: Serological identification, antimicrobial susceptibility testing, multilocus sequence typing (MLST), and whole genome sequencing were performed on Salmonella isolated from blood and stool samples in Guangdong from 2018 to 2022. Simultaneously, annotated the sequencing results for drug resistance genes and virulence factors by a microbial gene annotation system. Results: The 136 iNTS strains were divided into 25 serotypes, and Salmonella enteritidis accounted for 38.24% (52/136). The OR of other iNTS serotypes were calculated with Salmonella typhimurium as the control. The OR values of Oreninburg, Rysson, and Pomona serotypes were the highest, which were 423.50, 352.92, and 211.75, respectively. The drug resistance rate of iNTS was 0.74%-66.91%, which was lower than that of non-iNTS (3.90%-77.21%). The main iNTS of drug resistance were ampicillin and tetracycline, with resistance rates of 66.91% (91/136) and 50.00% (68/136), respectively, while the resistance rates to ciprofloxacin (5.88%,8/136), ceftazidime (5.88%,8/136), gentamicin (5.13%,7/136) and cefoxitin (0.74%, 1/136) were relatively low. iNTS carried a variety of drug-resistance genes and virulence factors, but no standard virulence factor distribution has been found. MLST cluster analysis showed that iNTS was divided into 26 sequence types, and ST11 accounted for 38.24% (52/136). Conclusions: The iNTS strains in Guangdong were dominated by Salmonella enteritidis, of which three serotypes, Oreninburg, Rison, and Pomona, may be associated with a higher risk of invasive infection during 2018 to 2022. iNTS was sensitive to clinical first-line therapeutic drugs (cephalosporins and fluoroquinolones), with highly diverse sequences and clear phylogenetic branches. ST11 was the local dominant clone group.