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Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.

We investigate an interlayer of 6,6′-bis(4-(bis(4-methoxyphenyl)amino)phenyl)-[1,1′-binaphthalene]-(2,2′-diyl)bis(oxy)bis(propane-3,1-diyl)bis(phosphonic acid) (BINOL-PA) with undoped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) coverage. The incorporation of the 1,10-bi-2-naphthol central core enhances π–π stacking and reduces charge recombination at the interface. Compared to PTAA alone (0.95 eV), BINOL-PA/PTAA exhibits a shorter distance from the Fermi energy (EF) to the valence-band maximum (VBM) (0.36 eV). Two phosphoric acid units in BINOL-PA fine-tune the molecular dipoles. Theoretical calculations reveal electrostatic surface potential differences between BINOL-PA and PTAA in their backbone structure. Open-circuit voltage decay (OCVD) and electrochemical impedance spectroscopy (EIS) results suggest suppressed interface recombination. The photovoltaic conversion efficiency (PCE), short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF) for the BINOL-PA/PTAA device are measured as 21.02%, 22.67 mA cm–2, 1.12 V, and 82.8%, respectively, all higher than those achieved by the PTAA device with a PCE of 18%. BINOL-PA/PTAA significantly elevates VOCand FF values compared with dopant-free PTAA alone. The champion device retains over 89% of its initial PCE after being exposed to an ambient environment without encapsulation for more than 30 days. The thermal aging test conducted under a nitrogen atmosphere demonstrates that the efficiency retention rate for BINOL-PA/PTAA displays 60% of its initial efficiency after 1500 h.

In this article, the possibility of improving target detection performance in passive bistatic radar by jointly exploiting multiple signals at different carrier frequencies emitted by the same illuminator is investigated, namely multifrequency passive bistatic radar (MFPBR) coherent integration. Since the carrier frequency of each signal is agile, the MFPBR coherent integration suffers from the problems of range-phase incoherence and Doppler broadening. In order to tackle these challenges, a multifrequency coherent integration target detection algorithm for passive bistatic radar is proposed. Specifically, this scheme corrects the Doppler broadening effect via time stretch processing. Then, low-sidelobe filtering based on convex optimization is carried out to remove the range-phase incoherence and obtain the multifrequency (MF) of the target's energy. Meanwhile, the high-range-resolution profiles of the target can be generated. The advantage of the proposed algorithm is that it can obtain superior coherent integration and detection performance for both single and multiple target scenarios compared to existing methods. Finally, a series of measured and simulation results are presented to demonstrate the effectiveness of the proposed algorithm.

A novel phase compensation method for the design of transmitarray is proposed in this article, enabling the gain enhancement for a dual-polarized 2-D multibeam antenna for the first time. The multibeam antenna is implemented in three-stacked printed circuit board laminates. Two sets of Butler matrices in substrate integrated waveguide (SIW) technology are vertically placed at different layers to feed the upper $2\times 2$ dual-polarized magneto-electric (ME) dipole antenna array. To verify the proposed method, a transmitarray employing the novel phase compensation method is designed as an overlay, consisting of $40\times 40$ single-layer dual-polarized unit cells. Finally, the whole high-gain 2-D multibeam antenna operating at the center frequency of 26 GHz is simulated and experimentally validated. The measured -10-dB impedance bandwidth achieves more than 23.1%, and the measured peak gain is 17.8 dBi for x-polarization and 17.9 dBi for y-polarization. The proposed transmitarray provides a maximum gain enhancement of 8.8 dB at 26 GHz. The measurements are in good agreement with the simulation results. The proposed method is general to other multibeam antennas of arbitrary scale for 5G millimeter-wave (mmWave) applications.

The first example rotaxane@MOF (named as CUST-761) has been designed and constructed via combining CB[6]-based rotaxane ([PR44]2+·2[NO3]−), 4,4′-biphenyldicarboxylate sodium salts (Na2BPDC), and transition metal cadmium ion under solvothermal conditions. X-ray single crystal diffraction revealed CUST-761exhibits a two-dimensional (2D) layered structure where rotaxanes are well embedded in the crystal lattices formed by BPDCs and cadmium ions. Thermogravimetric analysis (TGA) and Powder X-ray diffraction (PXRD) showed that CUST-761possesses excellent stability. The utility of CUST-761as fluorescence sensors has also been discussed. The results indicated that CUST-761can be used as a multiresponsive fluorescence sensor for detecting Fe3+and Cr2O72–with good sensitivity, high selectivity, and recoverability, even in the presence of other interfering ions. Besides, CUST-761also can selectively detect nitrofurantoin. The mechanism of CUST-761as a multiresponsive fluorescence sensor for detecting Fe3+, Cr2O72–, and the antibiotic nitrofurantoin has been clarified by experiments and theoretical calculations. This work provides insights into the design and synthesis of fluorescence sensing crystal-state materials.

Objective: Alzheimer’s disease (AD) has become a significant global concern, but effective drugs able to slow down AD progression is still lacked. Electroacupuncture (EA) has been demonstrated to ameliorate cognitive impairment in individuals with AD. However, the underlying mechanisms remains poorly understood. This study aimed at examining the neuroprotective properties of EA and its potential mechanism of action against AD. Methods: APP/PS1 transgenic mice were employed to evaluate the protective effects of EA on Shenshu(BL 23) and Baihui(GV 20). Chemogenetic manipulation was used to activate or inhibit serotonergic neurons within the dorsal raphe nucleus (DRN). Learning and memory abilities were assessed by the novel object recognition and Morris water maze tests. Golgi staining, western blot, and immunostaining were utilized to determine EA-induced neuroprotection. Results: EA at Shenshu(BL 23) and Baihui(GV 20) effectively ameliorated learning and memory impairments in APP/PS1 mice. EA attenuated dendritic spine loss, increased the expression levels of PSD95, synaptophysin, and brain-derived neurotrophic factor in hippocampus. Activation of serotonergic neurons within the DRN can ameliorate cognitive deficits in AD by activating glutamatergic neurons mediated by 5-HT1B. Chemogenetic inhibition of serotonergic neurons in the DRN reversed the effects of EA on synaptic plasticity and memory. Conclusion: EA can alleviate cognitive dysfunction in APP/PS1 mice by activating serotonergic neurons in the DRN. Further study is necessary to better understand how the serotonergic neurons-related neural circuits involves in EA-induced memory improvement in AD.

Characterized by progressive and irreversible degeneration of the articular cartilage (AC), osteoarthritis (OA) is the most common chronic joint disease, and there is no cure for OA at present. Recent studies suggest that enhancing the recruitment of endogenous mesenchymal stem cells (MSCs) to damaged cartilage is a promising therapeutic strategy for cartilage repair. Tetrahedral framework nucleic acid (tFNA) is a novel DNA nanomaterial and has shown great potential in the field of biomedical science. Transforming growth factor-beta 3 (TGF-β3), a vital member of the highly conserved TGF-β superfamily, is considered to induce chondrogenesis. A 66-base DNA aptamer named HM69 is reported to identify and recruit MSCs. In this study, aptamer HM69-modified tFNAs were successfully self-assembled and used to load TGF-β3 when the disulfide bonds combined. We confirmed the successful synthesis of the final composition, HM69-tFNA@TGF-β3 (HTT), by PAGE, dynamic light scattering, and atomic force microscopy. The results of in vitro experiments showed that HTT effectively induced MSC proliferation, migration, and chondrogenic differentiation. In addition, HTT-treated MSCs were shown to protect the OA chondrocytes. In DMM mice, the injection of HTT improved the therapeutic outcome of mouse pain symptoms and AC degeneration. In conclusion, this study innovatively used the disulfide bonds combined with TGF-β3 and tFNA, and an additional sequence HM69 was loaded on tFNA for the better-targeted recruitment of MSCs. HTT demonstrated its role in promoting the chondrogenesis of MSCs and cartilage protection, indicating that it might be promising for OA therapy.

Plants have complex detoxification and metabolic systems that enable them to deal with environmental pollutants. We report accumulation of the pesticide isoproturon (IPU) in a BR signaling pathway for mutant bzr4-3/5 rice to be significantly higher than in wild-type (WT) rice controls and for exogenous 24-epibrassinolide to reverse toxic symptoms in WT rice but not in mutants. A genome-wide RNA sequencing study of WT/bzr4rice is performed to identify transcriptomic changes and metabolic mechanisms under IPU exposure. Three differentially expressed genes in yeast cells increase the degradation rate of IPU in a growth medium by factors of 1.61, 1.51, and 1.29 after 72 h. Using UPLC/Q-TOF-MS/MS, five phase I metabolites and five phase II conjugates are characterized in rice grains, with concentrations generally decreasing in bzr4rice grains. OsBZR4, a regulator of IPU degradation in rice, may eliminate IPU from edible parts of food crops by regulating downstream metabolic genes.

We describe a visible light-induced palladium-catalyzed radical germylative arylation of alkenes with easily accessible chlorogermanes. This protocol provides expedient access to germanium-substituted indolin-2-ones in good to excellent yields under mild reaction conditions. The key step for this strategy lies in the reductive activation of germanium–chloride bonds with an excited palladium complex under visible light irradiation. The involvement of germanium radicals was evidenced by electron paramagnetic resonance spectroscopy experiments.

Background: The peak power density of the hard X-ray nano-probe beamline is the highest at SSRF (Shanghai Synchrotron Radiation Facility). The peak power density of the front-end is 77.43 kW/mrad2, which is about 1.7 times higher than the others, for the fixed mask 1 (FM1) which is 11,440 mm away from the light source. However, adopting the traditional design may cause the major power absorbed by the downstream fixed mask 2 (FM2). Purpose: In order to evenly absorb the heat and ensure smooth beam transmission. Methods: The synchrotron beam tracing was performed, and the separate mask absorption approach was adopted. Additionally, finite element analysis (FEA) was conducted to analyze the thermodynamic behavior of FMs. Result: Currently, the front-end has been successfully designed and is running smoothly.

Enzymes, a class of biocatalysts, exhibit remarkable catalytic efficiency, specificity, and selectivity, governing many reactions that are essential for various cascades within living cells. The immobilization of structurally flexible enzymes on appropriate supports holds significant importance in facilitating biomimetic transformations in extracellular environments. Covalent organic frameworks (COFs) have emerged as ideal candidates for enzyme immobilization due to high surface tunability, diverse chemical/structural designs, exceptional stability, and metal-free nature. Various immobilization techniques have been proposed to fabricate COF-enzyme biocomposites, offering significant enhancements in activity and reusability for COF-immobilized enzymes as well as new insights into developing advanced enzyme-based applications. In this review, we provide a comprehensive overview of state-of-the-art strategies for immobilizing enzymes within COFs by focusing on their applicability and versatility. These strategies are systematically summarized and compared by categorizing them into postsynthesis immobilization and in situ immobilization, where their respective strengths and limitations are thoroughly discussed. Combined with an overview of critical emerging applications, we further elucidate the multifaceted roles of COFs in enzyme immobilization and subsequent applications, highlighting the advanced biofunctionality achievable through COFs.

Biomacromolecular condensates formed via phase separation establish compartments for the enrichment of specific compositions, which is also used as a biological tool to enhance molecule condensation, thereby increasing the efficiency of biological processes. Proteolysis-targeting chimeras (PROTACs) have been developed as powerful tools for targeted protein degradation in cells, offering a promising approach for therapies for different diseases. Herein, we introduce an intrinsically disordered region in the PROTAC (denoted PSETAC), which led to the formation of droplets of target proteins in the cells and increased degradation efficiency compared with PROTAC without phase separation. Further, using a nucleus targeting intrinsically disordered domain, the PSETAC was able to target and degrade nuclear-located proteins. Finally, we demonstrated intracellular delivery of PSETAC using lipid nanoparticle-encapsulated mRNA (mRNA-LNP) for the degradation of the endogenous target protein. This study established the PSETAC mRNA-LNP method as a potentially translatable, safe therapeutic strategy for the development of clinical applications based on PROTAC.

Intensive selection pressure constrains the evolutionary trajectory of SARS-CoV-2 genomes and results in various novel variants with distinct mutation profiles. Point mutations, particularly those within the receptor binding domain (RBD) of SARS-CoV-2 spike (S) protein, lead to the functional alteration in both receptor engagement and monoclonal antibody (mAb) recognition. Here, we review the data of the RBD point mutations possessed by major SARS-CoV-2 variants and discuss their individual effects on ACE2 affinity and immune evasion. Many single amino acid substitutions within RBD epitopes crucial for the antibody evasion capacity may conversely weaken ACE2 binding affinity. However, this weakened effect could be largely compensated by specific epistatic mutations, such as N501Y, thus maintaining the overall ACE2 affinity for the spike protein of all major variants. The predominant direction of SARS-CoV-2 evolution lies neither in promoting ACE2 affinity nor evading mAb neutralization but in maintaining a delicate balance between these two dimensions. Together, this review interprets how RBD mutations efficiently resist antibody neutralization and meanwhile how the affinity between ACE2 and spike protein is maintained, emphasizing the significance of comprehensive assessment of spike mutations.

To consider the coupled effect on the running safety between elastic track and longitudinal impulse of Long Heavy Haul Train(LHHT), a train/track coupled dynamics model is established by using connection substructure theory. The ballasted track is divided into several segments called sub-tracks: a sub-track includes rail, sleepers and ballast. In the sub-track model, the sleepers and ballast are modelled as lumped mass. The rail is divided into the contact and connection rail. The contact rail is modelled as an Euler beam to reflect the wheel/rail interaction and the flexible vibration of the rail. The connection rail is modelled as a super element to reflect the interaction between adjacent contact rail. To increase the simulation speed, a new parallel computing method is proposed: a train/track coupled dynamics model is divided into different submodule, a submodule includes a sub-track and a vehicle on the sub-track. A submodule is calculated by a single computer core. The submodule is connected by connection rail, couplers and ballast. The advantage of this parallel method is that the load of each computer core is almost uniform. The simulation speed depends on the number of parallel computing cores instead of one core with a particularly large load. Finally, taking the 10,000-ton train as an example, the distribution of coupler force, the derailment coefficient and wheel unloading rate are given during the train braking on a curve, which shows the application and necessity of the train/track coupled dynamics model based on substructure and parallel computing.

The operational stability of radial journal bearings is the bottleneck that limits the reliability of hydraulic suspension micro-pump. Due to self-excited vibrations, the whirl amplitude of the plain journal bearing (PJB) is large at high rotational speeds, which will accelerate wear failure. It has been proven that employing herringbone grooved journal bearing (HGJB) is an effective method to reduce the whirl amplitude and improve operational stability. However, enhancing the stability of journal bearings in micro-pumps by herringbone grooved structures has rarely been studied, and its effect needs to be verified. We validated the mechanism of the stability improvement with the CFD method and compared the dynamic characteristics of HGJB and PJB by rotor dynamics evaluation and experiment. The experimental results show that under the same conditions the whirl amplitude of the HGJB decreases by 29.61% in the xdirection and by 24.09% in the ydirection compared with that of the PJB. This study reveals the effect of the herringbone grooved structure on the operational stability of bearings and may provide guidance for the reliability improvement of hydraulic suspension micro-pump.

Purpose: The mounted stationary sensor on the ring casing has become a widely accepted way to monitor the planetary gear condition and one challenging aspect of this method is the modulation effect caused by the moving planet gears. It is valuable to study the modulation effect caused by the moving planet gears. Method: Different window functions have been proposed to model this modulation phenomenon and there are several drawbacks: the selection of the window function parameters is often arbitrary and subjective instead of basing on the planetary gear physical parameter; the current window function is hard to reflect the impact from the ring gear boundary conditions. Therefore, this paper simulated this modulation phenomenon as moving load dynamic problem to overcome these drawbacks, where the ring casing has been modelled as an axisymmetric flexible structure and the internal meshing forces have been modelled as spatially varying moving loads. Based on the improved hamming window function, this paper related the window function parameters with the planetary gear physical properties and operation conditions and then, quantified the modulation effect with the consideration of moving load speed as well as the ring gear boundary condition. Results: For the planetary gear carrier arm rotation speed, the result suggested that the moving speed mainly affect the parameter β and the corresponding value showed a nonlinear decreasing trend when the moving speed increased. For the ring gear rim thickness, similarly, parameter β increased significantly with the increase of the rim value. For the radial support stiffness, parameter β has also been affected most and it shows a decreasing trend when the support stiffness increased. For the sensor location, both parameter α and β shows a periodical change around the ring casing. Conclusion: The results suggested that both parameters have been impacted by the rotation speed and boundary conditions, among which parameter β has been impacted most.

The classical theory of the electrical double layer (EDL) does not consider the effects of the electrode surface structure on the EDL properties. Moreover, the best agreement between the traditional EDL theory and experiments has been achieved so far only for a very limited number of ideal systems, such as liquid metal mercury electrodes, for which it is challenging to operate with specific surface structures. In the case of solid electrodes, the predictive power of classical theory is often not acceptable for electrochemical energy applications, e.g., in supercapacitors, due to the effects of surface structure, electrode composition, and complex electrolyte contributions. In this work, we combine ab initiomolecular dynamics (AIMD) simulations and electrochemical experiments to elucidate the relationship between the structure of Pt(hkl) surfaces and the double-layer capacitance as a key property of the EDL. Flat, stepped, and kinked Pt single crystal facets in contact with acidic HClO4media are selected as our model systems. We demonstrate that introducing specific defects, such as steps, can substantially reduce the EDL capacitances close to the potential of zero charge (PZC). Our AIMD simulations reveal that different Pt facets are characterized by different net orientations of the water dipole moment at the interface. That allows us to rationalize the experimentally measured (inverse) volcano-shaped capacitance as a function of the surface step density.

Metagenomics has enabled the comprehensive study of microbiomes. However, many applications would benefit from a method that sequences specific bacterial taxa of interest, but not most background taxa. We developed mEnrich-seq (in which ‘m’ stands for methylation and seq for sequencing) for enriching taxa of interest from metagenomic DNA before sequencing. The core idea is to exploit the self versus nonself differentiation by natural bacterial DNA methylation and rationally choose methylation-sensitive restriction enzymes, individually or in combination, to deplete host and background taxa while enriching targeted taxa. This idea is integrated with library preparation procedures and applied in several applications to enrich (up to 117-fold) pathogenic or beneficial bacteria from human urine and fecal samples, including species that are hard to culture or of low abundance. We assessed 4,601 bacterial strains with mapped methylomes so far and showed broad applicability of mEnrich-seq. mEnrich-seq provides microbiome researchers with a versatile and cost-effective approach for selective sequencing of diverse taxa of interest.

Cd pollution-safe cultivar (Cd-PSC) is a feasible strategy to minimize Cd contamination in leafy vegetables. The shoot Cd concentrations of 23 Lactuca sativacultivars under Cd stress ranged from 0.124 to 2.155 mg·kg–1with a maximum cultivar difference of 8 folds. Typical Cd-PSC C16 (L) and high-Cd-accumulating cultivar C13 (H) were screened to investigate the mechanisms of Cd accumulations in L. sativathrough determining Cd concentrations, Cd subcellular distributions, phytochelatin profiles, and phytochelatin biosynthesis-related genes’ expressions. Higher Cd distribution in a heat stable fraction in C13 (H) indicated that the high Cd accumulation trait of C13 (H) mainly depended on the Cd-phytochelatin complexes. Root phytochelatin concentrations were significantly elevated in C13 (H) (5.83 folds) than in C16 (L) (2.69 folds) (p< 0.05) under Cd stress. Significantly downregulated expressions of glutathione S-transferase rather than the regulation of phytochelatin synthesis genes in the root of C13 (H) might be responsible for sufficient glutathione supply for phytochelatins synthesis. These findings suggested that phytochelatin elevation in C13 (H) would favor the Cd root to shoot transportation, which provides new insights into the phytochelatin-related cultivar-dependent Cd accumulating characteristic in L. sativa.

In the sensorless control system of permanent magnet synchronous motor (PMSM), the controller dead time will lead to the rotor position observation error. If there is parameter and load disturbance, the rotor position observation error will be further amplified, resulting in obvious harmonics. The rotor position observation error will be fed back to the control system and affect the control effect. In this paper, the influence of sensorless rotor Angle estimation error on dead-time current ripple is quantitatively analyzed. Then a harmonic suppression strategy for sensorless PMSM is proposed based on Proportional Complex Integration (PCI) algorithm and Active Disturbance Rejection Control (ADRC). In this paper, the stability of this strategy and the suppression effect of high-frequency specific harmonics are proved by combining the control theory. Then, an experimental platform is set up to carry out harmonic suppression, dynamic tracking, and parameter robustness experiments to verify the effectiveness and feasibility of this strategy.

A method for designing broadband dual-polarization thin aperture with a small focal length to diameter ratio (F/D) is proposed for low-profile transmitarray antenna (TA). The aperture is composed of two types of narrowband subwavelength unit cells, namely the wire-loop Huygens’ unit cell and the stacked I-shaped cross unit cell. The two types of unit cells collaborate to achieve complete 360° phase coverage and uphold a high transmittance (> −1.3 dB). Both unit cells possess the capability to manipulate dual polarization electromagnetic (EM) waves, exhibit strong angular stability, and have a period of $0.165\lambda _{0}$ (where $\lambda _{0}$ is the free space wavelength at 9 GHz). Furthermore, the subwavelength period of the unit cells enhances the sampling frequency of the aperture, thereby effectively mitigating aperture distortion caused by unit cell failure resulting from frequency variations. Hence, despite the narrowband nature of the unit cells, the aperture enables broadband performance. The proposed aperture design method offers a more efficient solution for broadband small F/D compared to the conventional TA design method, with reduced design complexity, thinner aperture thickness, and simplified unit cell structure. Finally, the proposed methodology is utilized to design the aperture of a TA prototype with an F/D of 0.32, which is equipped with a broadband magneto-electric (ME) dipole feed. The measured results demonstrate that the 2.5-dB gain bandwidth (BW) of the TA prototype is 17.02%.

Deep learning models have shown great potential in reducing low-dose (LD) positron emission tomography (PET) image noise by estimating full-dose (FD) images from the corresponding LD images. Those models, however, when trained on paired LD-FD PET images from a source scanner, fail to generalize well when applied to LD PET images from a target scanner, due to a phenomenon called “domain drift.” In this study, we present a method for cross-scanner LD PET image noise reduction. This is done via a self-ensembling framework using a limited number of paired LD-FD PET images and a large number of LD PET images from the target scanner. The self-ensembling framework leverages the paired 2-D slices from both scanners to learn a regression model. It additionally incorporates a consistency loss on the LD PET images from the target scanner to enhance the model’s generalization capability. We conduct experiments on three datasets, respectively, acquired from three different scanners, including a GE Discovery MI (DMI) scanner, a Siemens Biograph Vision 450 (Vision) scanner, and a UI uMI 780 (uMI) scanner. Results from our comprehensive experiments demonstrate the generalization capability of our method.

A novel and general approach is proposed for holographic antennas (HAs) to achieve high aperture efficiency with a compact aperture size. A theoretical demonstration of this behavior is found by investigating the relationship between the attenuation constant and the aperture efficiency. Meanwhile, double-layer cross-embedded tensor unit cell is proposed, to achieve more continuous surface impedance distribution. Moreover, the attenuation constant $\alpha $ and conversion efficiency $\varepsilon _{\mathrm {conv}}$ are improved without enlarging the aperture size and sacrificing the gain bandwidth. In this case, the double-layer topology approaches the theoretical maximum aperture efficiency with compact size. It is worth mentioning that, the proposed method is compatible with both uniform and nonuniform modulated HAs. As a validation, two double-layer HAs designed with the respective uniform and nonuniform modulation index are analyzed, fabricated, and measured. Both are with a compact aperture dimension of $4.15^{2}~\pi \cdot \lambda _{0}^{2}$ at 26 GHz. Compared with conventional single-layer HA, the first prototype achieves an increased realized gain of 2.3 dB and an aperture efficiency of 44.3%, while the second prototype achieves an enhanced realized gain of 2.8 dB and an aperture efficiency of 49.1%, respectively. The HAs feature compact size, high efficiency, low cost, and planar integration, rendering them good prospects for the 5th generation (5G) millimeter-wave (mm-wave) applications.

In view of the temperature control system with Programmable Logic Controller (PLC) as the core, the main problems focus on the inability to realize wireless communication, remote downloading, poor temperature stability and poor anti-interference ability. A multi-channel Proportional Integral Differential (PID) temperature control system based on PLC and Internet of Things (IOT) is designed. It can not only adjust the temperature in real time. But also, the thirdparty cloud platform can be used through Message Queuing Telemetry Transport (MQTT) protocol, wireless data monitoring and remote control can also be carried out, and PLC programs can be downloaded remotely. Compared with the traditional wired monitoring system, it has great advantages and brings unprecedented convenience to the maintenance of the equipments. Based on the prototype, the multi-channel temperature stability and anti-interference tests, and wireless communication monitoring and alarm tests are carried out. The results show that the actual temperature of the system can change with the set value by PID control algorithm with the multi-channel heaters, and the temperature stability can reach ± 0.1 °C in steady state. In addition, real-time data such as temperature, voltage and current can be obtained through the cloud platform monitoring interface. And after triggering the alarm, the mobile devices (such as mobile phones) receive messages in real time.

Exosomes exhibit high bioavailability, biological stability, targeted specificity, low toxicity, and low immunogenicity in shuttling various bioactive molecules such as proteins, lipids, RNA, and DNA. Natural exosomes, however, have limited production, targeting abilities, and therapeutic efficacy in clinical trials. On the other hand, engineered exosomes have demonstrated long-term circulation, high stability, targeted delivery, and efficient intracellular drug release, garnering significant attention. The engineered exosomes bring new insights into developing next-generation drug delivery systems and show enormous potential in therapeutic applications, such as tumor therapies, diabetes management, cardiovascular disease, and tissue regeneration and repair. In this review, we provide an overview of recent advancements associated with engineered exosomes by focusing on the state-of-the-art strategies for cell engineering and exosome engineering. Exosome isolation methods, including traditional and emerging approaches, are systematically compared along with advancements in characterization methods. Current challenges and future opportunities are further discussed in terms of the preparation and application of engineered exosomes.

The holographic antenna is an impedance-modulated periodic leaky-wave antenna. The radiation efficiency is higher in the region closer to the feed because of uneven leaky-wave radiations and thus limits the overall aperture efficiency. To alleviate this issue, this paper proposes a nonuniform proportional impedance modulation method. By employing directional-fed topology and controlling the leakage rate in different regions on the aperture surface, the aperture efficiency is significantly improved without sacrificing bandwidth. To validate the proposed idea, a reflector-based scalar holographic antenna is analyzed, simulated and experimentally validated. The measurement results show 3 dB gain bandwidth of 49% within 14.8–24.4 GHz and a maximum aperture efficiency of 27.5%. Moreover, the beam scanning range is 5°–61° within the 3 dB gain bandwidth. The proposed method is promising to realize a holographic antenna with wide bandwidth, high aperture efficiency, and planar integration simultaneously.

Given a set of clients and a set of facilities with different priority levels in a metric space, the Budgeted Priorityp-Medianproblem aims to open a subset of facilities and connect each client to an opened facility with the same or a higher priority level, such that the number of opened facilities associated with each priority level is no more than a given upper limit, and the sum of the client-connection costs is minimized. In this paper, we present a data reduction-based approach for limiting the solution search space of the Budgeted Priorityp-Medianproblem, which yields a (1+ε)-approximation algorithm running in O(ndlogn)+(pε-1)pε-O(1)nO(1)time in d-dimensional Euclidean space, where nis the size of the input instance and pis the maximal number of opened facilities. The previous best approximation ratio for this problem obtained in the same time is (3+ε).

A wideband folded reflectarray antenna (FRA) is proposed in this letter. The differential slot feed employs a 180° feeding network for in-phase radiation. It is inherently integrated with the main reflector of FRA in a single-layer printed circuit board (PCB). Meanwhile, multiresonance unit is designed to achieve a wide bandwidth and a phase range exceeding 360°. To validate the proposed method, a 40 GHz FRA with an electrical size of 12.4 × 12.4λ02 is designed and fabricated. The measurement results show a 10 dB impedance bandwidth of 22.7% and a 3 dB gain bandwidth of 21.6%. Moreover, the maximum gain is 28.6 dBi with aperture efficiency of 39.3%. Compared with the published FRAs using planar integrated feed, the proposed FRA widely expands the impedance and gain bandwidth. It also features low profile, low cost, high aperture efficiency, and easy integration with active front ends.

In recent years, neural architecture search (NAS) methods have been proposed for the automatic generation of task-oriented network architecture in image classification. However, the architectures obtained by existing NAS approaches are optimized only for classification performance and do not adapt to devices with limited computational resources. To address this challenge, we propose a neural network architecture search algorithm aiming to simultaneously improve the network performance and reduce the network complexity. The proposed framework automatically builds the network architecture at two stages: block-level search and network-level search. At the stage of block-level search, a gradient-based relaxation method is proposed, using an enhanced gradient to design high-performance and low-complexity blocks. At the stage of network-level search, an evolutionary multiobjective algorithm is utilized to complete the automatic design from blocks to the target network. The experimental results demonstrate that our method outperforms all evaluated hand-crafted networks in image classification, with an error rate of 3.18% on Canadian Institute for Advanced Research (CIFAR10) and an error rate of 19.16% on CIFAR100, both at network parameter size less than 1 M. Obviously, compared with other NAS methods, our method offers a tremendous reduction in designed network architecture parameters.

Pretherapy dosimetry prediction is a prerequisite for treatment planning and personalized optimization of the emerging radiopharmaceutical therapy (RPT). Physiologically based pharmacokinetic (PBPK) model, describing the intrinsic pharmacokinetics of radiopharmaceuticals, have been proposed for pretherapy prediction of dosimetry. However, it is restricted with organwise prediction and the customization based on pretherapy measurements is still challenging. On the other side, artificial intelligence (AI) has demonstrated the potential in pretherapy dosimetry prediction. Nevertheless, it is still challenging for pure data-driven model to achieve voxelwise prediction due to huge gap between the pretherapy imaging and post-therapy dosimetry. This study aims to integrate the PBPK model into deep learning for voxelwise pretherapy dosimetry prediction. A conditional generative adversarial network (cGAN) integrated with the PBPK model as regularization was developed. For proof of concept, 120 virtual patients with 68Ga-PSMA-11 PET imaging and 177Lu-PSMA-I&T dosimetry were generated using realistic in silico simulations. In kidneys, spleen, liver and salivary glands, the proposed method achieved better accuracy and dose volume histogram than pure deep learning. The preliminary results confirmed that the proposed PBPK-adapted deep learning can improve the pretherapy voxelwise dosimetry prediction and may provide a practical solution to support treatment planning of heterogeneous dose distribution for personalized RPT.

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations, and determining appropriate closing laws of guide vanes (GVs) and runner blades (RBs) for this process is of significance. In this study, we proposed a procedure to optimize the co-closing law of GVs and RBs by using computational fluid dynamics (CFD), combined with the design of experiment (DOE) method, approximation model, and genetic optimization algorithm. The sensitivity of closing law parameters on the histories of head, speed, and thrust was analyzed, and a two-stage GVs’ closing law associating with a linear RBs’ closing law was proposed. The results show that GVs dominate the transient characteristics by controlling the change of discharge. Speeding GVs’ first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure; slowing GVs’ second-stage closing speed is conducive to controlling the maximum reverse axial force. RBs directly affect the runner force. Slowing RBs’ closing speed can further reduce the rotational speed and the maximum reverse axial force. The safety margin of each control parameter, flow patterns, and pressure pulsations of a practical hydropower station were all improved after optimization, demonstrating the effectiveness of this method.

An ultrathin dual polarization Huygens’ element (HE) is proposed based on a novel degeneracy method for electric and magnetic resonance modes. This HE exhibits a wider operation bandwidth (BW) and higher transmittance than the other hole-free dual-polarization lens antenna (LA) elements of similar thickness. By arranging three pairs of bilayer-dipole-pairs (BDPs) in parallel, the element achieves electric and magnetic resonance modes at the same frequency. In addition, the mutual coupling between the electric and magnetic resonance modes is effectively eliminated by implementing a reverse translation of the BDPs located at the edge of the element. The approach facilitates the realization of dual polarization Huygens’ resonance by combining two orthogonal BDPs. The proposed method eliminates the requirement for substrate thickness as the degree of freedom, enabling the element to achieve Huygens’ resonance even with an ultrathin substrate thickness as low as $0.05\lambda _{0}$ (where $\lambda _{0}$ is the free space wavelength). Furthermore, a cylindrical conformal LA operating in the Ka-band is designed based on this proposed HE. Due to the presence of broadband magnetoelectric degeneracy in the HE, the proposed LA prototype exhibits a wider gain BW compared to other conformal LAs with similar thicknesses. Moreover, the LA prototype achieves an aperture efficiency (AE) exceeding 30% due to the high transmittance provided by the proposed HE.

This brief proposes a miniaturized $4\times4$ Butler matrix using slow-wave ridged half-mode substrate integrated waveguide (RHMSIW). By etching the metal ridge of RHMSIW with periodic grooves, slow-wave characteristic is enabled with increased phase constant, and therefore couplers in Butler matrix are miniaturized. Compared with the conventional SIW-based ${H}$ -plane $4\times4$ Butler matrix, the electrical width and length of the proposed design are reduced by 82% and 34.3% respectively. The measured results agree well with the simulated results. The proposed miniaturized Butler matrix is promising for multibeam antennas with compact size, low cost and easy integration.

Endogenous opioid peptides (EOP) are the neurochemical basis of the anesthetic and analgesic effects of acupuncture, and the quantity of acupuncture stimulus can be controlled accurately by using electroacupuncture (EA). The present study explores the dose-effect relationship between EA with different parameters and the regulation of EOP system. In this paper, the intervention effects of EA on EOP system were specially discussed in terms of the single factor and the different combinations of the frequency, waveform and current intensity. This study shows that EOP system presents a frequency-response specificity. The low frequency of EA promotes the release of enkephalin, β-endorphin and endomorphin, the high one activates the dynorphin system selectively, and the intermediate frequency works on promoting the release of enkephalin and β-endorphin, as well as dynorphin. Sparse-dense wave of EA may induce the release of enkephalin, β-endorphin, endomorphin and dynorphin, presenting a synergistic effect. However, the waveform of EA should be selected flexibly in clinical practice. Sometimes the better therapeutic effect can also be obtained with the continuous wave of EA. EOP system is involved in mediating appropriate intensity of EA, while the acupuncture effect generated by an extra strong EA stimulation refers to a kind of stress response of non-opioid mechanism. The different combinations of EA parameters result in various effects. The combination of EA parameters should be optimized in accordance with different diseases, which is valuable for guiding clinical practice and the development of EA therapy.