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Positioning with 5G signals generally requires connection to several base stations (BSs), which makes positioning more demanding in terms of infrastructure than communications. To address this issue, there have been several theoretical studies on single BS positioning, leveraging high-resolution angle and delay estimation and multipath exploitation possibilities at mmWave frequencies. This paper presents the first realistic experimental validation of such studies, involving a commercial 5G mmWave BS with a customized beam sweep procedure and a user equipment (UE) development kit mounted on a test vehicle. We present the relevant signal models, and signal processing methods, and validate these based on data collected in an outdoor science park environment. Our results indicate that positioning is possible, but the performance is limited by the knowledge of the position and orientation of the infrastructure and the multipath visibility and diversity.

Current studies on commutation failure (CF) often remain a fixed critical extinction time for the blocking recovery of thyristor, ignoring the dynamic behavior of thyristor during turn-off period under AC faults, which may result in inaccuracies of CF identification. To overcome this problem, a line-commutated converter (LCC) model considering thyristor turn-off characteristics is required. In this paper, a charge calculation approach based on the dynamic behavior of PN junctions of the thyristor is proposed firstly. Then, the relationships of multi-factors influencing thyristor turn-off characteristics are clarified and the mechanism of multi-factors impacts on thyristor turn-off characteristics is elaborated by the presented charge calculation approach. Finally, an improved LCC model considering the dynamic behavior of thyristor during turn-off period is proposed, and developed in PSCAD/EMTDC. The comparisons between the proposed model and the traditional model indicate that dynamic behavior of thyristor during turn-off period under AC faults could significantly influence the accuracy of CF identification, including the timing of CF occurrences and CF possibility. The application of the proposed improved LCC model could improve the accuracy of CF identification.

Integrated communications and localization (ICAL) will play an important part in future sixth generation (6G) networks for the realization of Internet of Everything (IoE) to support both global communications and seamless localization. Massive multiple-input multiple-output (MIMO) low earth orbit (LEO) satellite systems have great potential in providing wide coverage with enhanced gains, and thus are strong candidates for realizing ubiquitous ICAL. In this paper, we develop a wideband massive MIMO LEO satellite system to simultaneously support wireless communications and localization operations in the downlink. In particular, we first characterize the signal propagation properties and derive a localization performance bound. Based on these analyses, we focus on the hybrid analog/digital precoding design to achieve high communication capability and localization precision. Numerical results demonstrate that the proposed ICAL scheme supports both the wireless communication and localization operations for typical system setups.

The thermal and ablation effects of lasers are widely used in laser additive manufacturing, laser welding, laser cleaning, and laser cladding technologies. Absorptivity is the core index of laser beam-thermal energy conversion efficiency. This paper analyzed the irradiated material's absorption behavior during the solid-liquid-gas evolution of laser-ablated metal surfaces by comparing the temperature fields and the corresponding weld cross-sections for different laser action periods, considering the fusion and vaporization latent heats. The solid-liquid-gas state evolution of high-power fiber laser-irradiated metal surfaces occurs during several milliseconds, with a short solid-phase existence period, since fusion or melting time is much shorter than the vaporization time. As the solid-liquid-gas state evolves, the average absorptivity and the share of thermal conduction energy loss decrease with the laser action time, while the fusion energy loss gradually increases. The solid-phase surface of the metal in laser processing absorbs significantly more incident laser energy than the liquid-phase one. The longer the solid-phase occurrence period of the metal surface during the laser action, the greater its average absorptivity of the incident laser. By increasing the laser spot area and scanning rate, the solid-phase period of the laser-irradiated metal surface can be increased, improving its incident laser absorptivity.

A superhydrophobic copper coating was prepared by combining ionic liquid copper electrodeposition and a brief stearic acid modification process. After modification, the copper stearic acid was well formed and flower-like clusters were present on the surface of the superhydrophobic coating. Finally, the surface of the sample exhibits a good superhydrophobic performance with a contact angle of 158° and obvious self-cleaning behavior. The results of potentiodynamic polarization and electrochemical impedance measurements revealed that the presence of a superhydrophobic surface could improve the anti-corrosion property of the samples.

By adjusting the inter-wire arc (IWA) posture, the skew-coupling arc (SCA) is proposed to address the polar effect in the cross arc, enabling decoupling control of heat, force, and mass transfer. Despite the advancement, the arc stabilization mechanism in the SCA remains poorly understood, hindering its application as a heat source in welding or additive manufacturing. To elucidate this mechanism, various influencing factors such as power supply characteristics, shielding gas composition, IWA posture, and plasma main arc (PMA) were analyzed. An electrical signal and high-speed camera synchronous acquisition system was utilized to analyze current-voltage waveforms and arc shapes. The results indicate that the arc stability of the SCA can be enhanced by ensuring specific external conditions. Constant voltage power supply enhances the self-regulating effect of the IWA, maintaining the IWA and the PMA in a hybrid state at all times. Introducing an oxidizing gas to the shielding gas can effectively suppress cathode spot climbing and stabilize the IWA. The vertical spacing between wires directly impacts the PMA deflection, while the wire horizontal angle has a lesser effect. The heat-regulating effect of the PMA column boosts the arc length regulation by the IWA. The current and the ion gas flow rate in the PMA minimally influence the SCA stability. These findings can provide a solid foundation for further applications of the SCA as heat source.

This study introduces a novel vector gas regulated plasma arc welding technique incorporating four auxiliary gas channels integrated within the water-cooled nozzle. Four different forms plasma arcs were generated by introducing four, three, two or none gas streams through the auxiliary channels respectively. Experimental and simulation methods were used to compare arc pressure, arc temperature characteristics for different arc types respectively. It was found that auxiliary gases can adjust the arc pressure and temperature field distribution on workpiece. In comparison to conventional plasma arc welding, the novel PAW can enhance the plasma arc penetration and adjust the thermal and force distribution. It offers increased welding efficiency and adaptability to diverse conditions, has a significant application potential in plasma arc welding technology.

Directed energy deposition (DED) represents a pivotal advancement in intelligent manufacturing, facilitating efficient near-net shape metal part production, particularly suited for aerospace and defense applications demanding high precision. Arc-based DED relies on meticulous process and trajectory planning, where AI-driven manufacturing systems optimize paths and parameters to surmount intricate physical phenomena like material melting and heat transfer. AI methodologies such as deep learning and big data analytics offer promising solutions. The exclusive process planning software for DED-Arc (EPPS−DED) broadens the technology's application domains. This paper comprehensively outlines core algorithms pertinent to EPPS-DED and essential process strategies for meticulous process planning, providing insights for software development and part quality enhancement. Key topics covered include 3D model slicing, path planning, printing efficiency, and scanning order for 2D contours with diverse geometries, alongside strategies for inclined structures and lattices. Moreover, it discusses the latest AI applications in process planning. The paper concludes with current progress and future outlooks aimed at refining the accuracy and performance of DED-fabricated components.

Herein, a novel and practical methodology for the photoinduced decarboxylative difluoroalkylation and perfluoroalkylation of a-fluoroacrylic acids is reported. A wide range of a-fluoroacrylic acids can be used as applicable feedstocks, allowing for rapid access to structurally important difluoroalkylated and polyfluoroalkylated monofluoroalkenes with high Z-stereoselectivity under mild conditions. The protocol demonstrates excellent functional group compatibility and provides a platform for modifying complex biologically active molecules.

Variable polarity plasma arc welding (VPPAW) is a highly efficient method for joining aluminum and magnesium alloys, primarily because of the automatic removal of oxide layers through cathode spots. Additionally, the high energy density generated by a variable polarity plasma arc creates a keyhole within the weld pool, enabling single-pass welding of medium-thick plates with minimal deformation and residual stress. Understanding the keyhole behaviors, arc physics, and control methodologies are essential to optimize and improve the stability of this welding process. This survey paper offers an overview of the development of the VPPAW process and its recent developments of detecting, modeling, and controlling. It shows that the potential applications of hybrid processes derived from VPPAW have expanded. Advanced process detection techniques, particularly the utilization of X-ray-based vision systems for the in-situobservation of molten metal flow, have significantly contributed to the understanding of VPPAW. Moreover, studies investigating VPPAW across different welding positions have enhanced the adaptability of this welding method. Accurate numerical models and intelligent deep learning methodologies have been crucial in unveiling the underlying mechanisms and facilitating the predictive analysis of welding quality.

Proso millet is a traditional grain that can be divided into waxy and nonwaxy varieties based on amylose content. However, research on different varieties of cooked proso millet is limited, especially as a whole grain. This paper investigated the quality properties and aroma characterization of cooked nonwaxy proso millet (NPM) and waxy proso millet (WPM). Scanning electron microscopy images showed that cooked NPM exhibited a more compact structure, whereas cooked WPM displayed a porous structure. Cooked NPM presented higher water absorption ratio, expansion ratio, hardness, and better chewiness than cooked WPM. Correlation analysis indicated that the texture properties were positively correlated with the cooking characteristics as well as the amylose and protein contents. The resistant starch content of cooked NPM (35.97%) was higher than that of cooked WPM (28.85%). Aroma analysis revealed that cooked NPM and WPM contained 56 and 67 volatile substances, respectively. Cooked NPM and WPM exhibited different properties mainly attributed to the various amylose and protein contents. These findings may provide a theoretical basis for the processing and commercial development of the proso millet resource.

Flickering light stimulation has emerged as a promising non-invasive neuromodulation strategy to alleviate neuropsychiatric disorders. However, the lack of a neurochemical underpinning has hampered its therapeutic development. Here, we demonstrate that light flickering triggered an immediate and sustained increase (up to 3 h after flickering) in extracellular adenosine levels in the primary visual cortex (V1) and other brain regions, as a function of light frequency and intensity, with maximal effects observed at 40 Hz frequency and 4000 lux. We uncovered cortical (glutamatergic and GABAergic) neurons, rather than astrocytes, as the cellular source, the intracellular adenosine generation from AMPK-associated energy metabolism pathways (but not SAM-transmethylation or salvage purine pathways), and adenosine efflux mediated by equilibrative nucleoside transporter-2 (ENT2) as the molecular pathway responsible for extracellular adenosine generation. Importantly, 40 Hz (but not 20 and 80 Hz) light flickering for 30 min enhanced non-rapid eye movement (non-REM) and REM sleep for 2–3 h in mice. This somnogenic effect was abolished by ablation of V1 (but not superior colliculus) neurons and by genetic deletion of the gene encoding ENT2 (but not ENT1), but recaptured by chemogenetic inhibition of V1 neurons and by focal infusion of adenosine into V1 in a dose-dependent manner. Lastly, 40 Hz light flickering for 30 min also promoted sleep in children with insomnia by decreasing sleep onset latency, increasing total sleep time, and reducing waking after sleep onset. Collectively, our findings establish the ENT2-mediated adenosine signaling in V1 as the neurochemical basis for 40 Hz flickering-induced sleep and unravel a novel and non-invasive treatment for insomnia, a condition that affects 20% of the world population.

IMPORTANCE: Excessive screen time has been associated with a higher risk for mental health problems, but whether the associations differ by screen content types is unclear. OBJECTIVE: To examine the allocation of and longitudinal changes in screen exposure across different content types and to explore their associations with mental health in children aged 3 to 6 years. DESIGN, SETTING, AND PARTICIPANTS: This cohort study used 3-wave, lagged generalized estimating equation models to analyze data from the Shanghai Children’s Health, Education and Lifestyle Evaluation–Preschool (SCHEDULE-P) study in Shanghai, China. The cohort was a representative sample of kindergarten children. Data were collected between November 2016 and May 2019 when children were aged 3 to 4 years (wave 1), 4 to 5 years (wave 2), and 5 to 6 years (wave 3). Data analysis was performed between June 2022 and May 2023. EXPOSURE: Screen exposure (total daily time and time with each type of content, including educational programs, entertainment programs, non–child-directed programs, electronic games, and social media) was collected when children were aged 3, 5, and 6 years. MAIN OUTCOMES AND MEASURES: Mental health of children at age 3, 5, and 6 years was reported by parents using the Strengths and Difficulties Questionnaire. RESULTS: Of the 15 965 children included in the representative sample, 8270 were males (51.7%) and the mean (SD) age at wave 1 was 3.73 (0.30) years. As children developed from ages 3 to 6 years, the proportion of screen exposure to educational programs (≤1 hour per day: 45.0% [95% CI, 43.5%-46.5%] to 26.8% [95% CI, 25.3%-28.3%]) and entertainment programs (≤1 hour per day: 44.4% [95% CI, 42.8%-45.9%] to 32.1% [95% CI, 30.4%-33.9%]) decreased, whereas exposure to social media increased (≤1 hour per day: 1.5% [95% CI, 1.2%-1.9%] to 27.1% [95% CI, 25.5%-28.7%]). The associations between on-screen content and mental health varied. For a given total screen time, a higher proportion of screen exposure to educational programs was associated with a lower risk for mental health problems (adjusted odds ratio [AOR], 0.73; 95% CI, 0.60-0.90), whereas non–child-directed programs were associated with a higher risk for such problems (AOR, 2.82; 95% CI, 1.91-4.18). Regardless of the content, total screen time was consistently associated with mental health problems. CONCLUSIONS AND RELEVANCE: Results of this study indicated that both total screen time and different types of content were associated with mental health problems in children aged 3 to 6 years. Limiting children’s screen time, prioritizing educational programs, and avoiding non–child-directed programs are recommended.

To prevent CaCO3scaling in oil and gas wells, scale inhibition are commonly used. This study utilized the molecular dynamics method to simulate the crystallization of a high concentration CaCO3solution, with particular attention given to the influence of the scale inhibitor sodium tripolyphosphate (Na5P3O10). Examination of the distribution of CO32−surrounding Ca2+indicated that P3O105−effectively hinders the interaction between CO32−and Ca2+, leading to a decrease in the root mean square displacement and diffusion coefficient of ions. Based on the analysis of intermolecular interaction energies, it is evident that the binding energy between Ca2+and CO32−is estimated at around 550 kcal/mol, whereas the binding energy between Ca2+and P3O105−is approximately 1000 kcal/mol. These data support the conclusion that P3O105−exhibits a higher affinity for Ca2+binding, thereby impeding the formation of CaCO3.

In group decision-making problems, trust relationships among experts often impact the evaluation information they provide for alternatives, and noncooperative behaviors are common in the consensus adjustment process. In the existing literature, cooperative game as a powerful tool is not well applied to cope with noncooperative behaviors of experts in terms of their adjustment willingness and adjustment cost. The objective of this article is to propose a group decision-making method with hesitant fuzzy preference relations based on the cooperative game to address the above issues comprehensively. To achieve this objective, the previous collaboration information of experts is applied to construct an undirected collaborative network, and trust weights of experts are determined according to the in-degree centrality of the undirected collaborative network. To determine the degree of consensus of experts, the integrated trust relationship and preference consistency level of experts are used as a referent standard for the collective preference. A cooperative game is introduced in the consensus adjustment process. Two factors, namely, experts’ adjustment willingness and unit adjustment cost, are included in the profit function of the game. In addition, the effects of changes in adjustment willingness and adjustment cost on the degree of consensus, the iteration number of games, and the ranking result of alternatives are analyzed. The effectiveness of the method is illustrated by an example regarding sustainable supply chain strategy selection. Comparisons with related methods are also presented. Results show that the proposed method can reflect trust relations and noncooperative behaviors of experts, and improve the degree of group consensus.

Three-dimensional point cloud classification is fundamental but still challenging in 3-D vision. Existing graph-based deep learning methods fail to learn both low-level extrinsic and high-level intrinsic features together. These two levels of features are critical to improving classification accuracy. To this end, we propose a dual-graph attention convolution network (DGACN). The idea of DGACN is to use two types of graph attention convolution operations with a feedback graph feature fusion mechanism. Specifically, we exploit graph geometric attention convolution to capture low-level extrinsic features in 3-D space. Furthermore, we apply graph embedding attention convolution to learn multiscale low-level extrinsic and high-level intrinsic fused graph features together. Moreover, the points belonging to different parts in real-world 3-D point cloud objects are distinguished, which results in more robust performance for 3-D point cloud classification tasks than other competitive methods, in practice. Our extensive experimental results show that the proposed network achieves state-of-the-art performance on both the synthetic ModelNet40 and real-world ScanObjectNN datasets.

The vertical industry member and the Internet of Things (IoT) business are spurring heated discussions on the evolution of future mobile communication. The emerging non-terrestrial network (NTN) plays increasingly important role in addressing service and coverage demand boom, whilst they still envisage technical and performance bottlenecks. Besides, traditional communication paradigm is constrained by Shannon theorem and fails to exploit the semantic features. In this article, we review the classic 6G NTN IoT networks and semantic communication in terms of structure, challenges, and applications. Then we observe that the superiority of semantic communication in low signal-to-noise ratio (SNR) regime is complementary to 6G NTN. We further propose an adaptive semantic-empowered 6G NTN IoT structure supporting communication paradigm switching. Finally, the open issues are discussed.

The direct/reductive amination of carbohydrate-based furoin and furil with NH3/H2was investigated to access amine derivatives. In the sole presence of NH3, cyclic amines, i.e.2,3,5,6-tetra(furan-2-yl)pyrazine and 2,2′-bipyridine-3,3′-diol, were generated as the main products from furoin and furil, respectively. Over Ru/Al2O3under NH3/H2, 2-amino-1,2-di(furan-2-yl)ethan-1-ol (i.e.alcohol–amine) was generated as the main product with 47% yield at 140 °C for 2 h starting from furoin. The catalyst could be recycled for at least three consecutive runs. An alcohol–imine was the main intermediate that underwent tautomerization to alcohol–enamine/keto–amine leading to cyclic by-products by self-condensation. DFT calculations, complementing the experimental observations, provided detailed molecular-level insight into the reactivity of the alcohol–imine intermediate. Its preferential adsorption on Ru centers viathe NH group, with the OH group pointing away from the surface, was found to direct its hydrogenation towards the alcohol–amine as main product. By combining Ru/Al2O3and a silica-anchored N-heterocyclic carbene (NHC) catalyst, the alcohol-amine could be accessed with 42% overall yield in a single reactor.

Allogeneic hematopoietic stem cell transplantation (HSCT) currently stands as the sole remedy for individuals afflicted with hemophagocytic lymphohistiocytosis (HLH). In this study, we retrospectively evaluated how pediatric patients with relapsed or refractory (R/R) HLH responded to our institution’s cocktail conditioning regimen. The disease was diagnosed according to criteria applicable to patients with familial/genetic, relapsing, or severe/persistent HLH. All donors were HLA haplo-identical family donors. In our cohort, sixty-five patients (P-HLH), including 28 with familial/genetic HLH, 36 with secondary HLH, and 1 with an unknown cause, underwent haplo-identical family donor HSCT. The conditioning regimen consisted of intravenous administration of etoposide (VP-16), busulfan, fludarabine, rabbit anti-human thymocyte globulin (r-ATG), and cyclophosphamide (Cy). Tacrolimus and mycophenolate mofetil were used for graft-versus-host disease (GvHD) prevention. We observed that the median time for neutrophil recovery was 11 days (range, 8–24), and for platelet counts to exceed 20 × 109/L, it was 14 days (range, 7–130). There were 5 patients (7.7%) who experienced grades III to IV acute GvHD, and 6 patients (9.2%) developed extensive chronic GvHD. The estimated 3- and 5-year overall survival rates were 78.1% (95% CI, 65.8–84.6%) and 74.9% (95% CI, 61.2–84.4%), respectively. The estimated 3- and 5-year event-free survival rates were 73.5% (95% CI, 60.8–82.6%) and 70.3% (95% CI, 56.4–80.5%), respectively. Our findings demonstrate that our innovative conditioning regimen is both effective and safe, offering valuable insights for healthcare professionals evaluating the merits of existing therapies.

This letter presents a hybrid decoupling technique to realize high isolation for dual-polarized dipole antennas. The proposed antenna consists of a cross-dipole on two horizontal layers, one in the x-axis direction directly fed by a coaxial line and its extended strip and another in the y-axis direction differentially excited by a wideband power divider. A wideband hybrid decoupling method is applied, and the designed antenna has a simulated port-to-port isolation of more than 52.4 dB in the overlapped −10 dB impedance wideband of 1.69–2.73 GHz (47.1%). The fabricated prototype obtains a high port-to-port isolation of more than 48.3 dB over the 1.73–2.73 GHz (44.8%) frequency band. At the same time, the antenna has a stable radiation pattern, realized gains of 8.6 ± 0.7 dBi at Port 1 and 8.7 ± 0.6 dBi at Port 2, and an average radiation efficiency of 86.2%. The above characteristics indicate that the proposed antenna qualifies as a candidate for the base station antenna system in the 1.7–2.7 GHz frequency band.

An enhanced isolation technique between two low-profile patch antennas is proposed. Two identical antennas are configured with two printed circuit boards (PCBs) spaced at 0.206λ0, where λ0 is the free-space wavelength at 3.5 GHz. Every antenna is a rectangular patch with four slots and two vias, vertically fed with a coaxial probe. A decoupling strip embedded between two antennas and a slot on the ground improves isolation, which would not deteriorate the cross-polarization and backward radiation levels. Two-port impedance match and isolation characteristics are analyzed when the two-antenna spacing varies from 0.159λ0 to 0.252λ0. The proposed antenna has a size of 0.817λ0 × 0.448λ0 × 0.038λ0. The fabricated prototype is measured, and the results demonstrate that the −10 dB impedance bandwidths are 3.37–3.61 GHz (6.88%), the port-to-port isolation is more than 45.2 dB, the realized gains are 4.53 ± 0.35 dBi, and the average radiation efficiencies are more than 70%. Therefore, the measured results agree well with the simulated, making it a promising candidate for in-band full-duplex applications in 5G terminal scenes.

A novel wideband circularly polarized (CP) dipole antenna is presented. The proposed antenna is configured with three horizontal layers of an electrical dipole, two parasite Π-strips, and a ground, where the electrical dipole is fed by a vertical microstrip balun, resulting in three CP modes. The 180° rotationally symmetric dipole generates two CP modes in the middle- and high-frequency bands. In order to improve the CP bandwidth, two 180° rotationally symmetric Π-strips are introduced and excite the third CP mode in the low-frequency band. The antenna prototype is fabricated, and the measured results show that the −10 dB impedance bandwidth is 1.63–3.98 GHz (83.78%), the 3 dB axial ratio bandwidth (ARBW) is 1.70–3.11 GHz (58.63%), the realized gain is 7.34 ± 0.32 dBi, and the average radiation efficiency is 80.61%. As a result, the 1 dB gain bandwidth is overlapped with the ARBW, and the realized gain has a high flatness over the ARBW. Therefore, the proposed antenna is a promising candidate for broadband CP wireless communication system applications.

This brief proposes a novel impulse-radio ultra-wideband (IR-UWB) transmitter circuit and system for high-speed wireless communication with a fractional digital time converter (DTC) and high spectrum efficiency modulation named as intra-chip pulse position modulation (Intra-Chip PPM). The transmitter achieves high precision and high dynamic range simultaneously combining counter and delay line for integer and fractional part of delay respectively. The maximum delay control range is 8012.8ps while the minimum delay resolution is 0.4ps, which is achieved by on-chip calibration of delay line, providing precise position information for high-speed Intra-chip PPM and multi-rate pulse modulation. The circuit of whole transmitter is designed and simulated with 40nm CMOS process. The simulation results show that the proposed transmitter can achieve maximum data rate of 1996.8Mb/s and energy efficiency of only 6.2pJ/bit.

The keyhole welding process in Variable Polarity Plasma Arc Welding enhances weld quality significantly, yet it introduces pool instability. Dynamic stability is pursued by investigating molten metal flowing within keyholes and their characteristics. Weld pool flow patterns are obtained via particle tracking, while instability characteristics are captured employing a high-speed camera. Analysing directional molten metal flow unveils Convergence and Separation Points in weld pool flow. The latter's displacement induces weld pool instability, resulting in an increase in keyhole area and a reduction in the pinch angle. The keyhole area signifies pool instability, while the rear wall angle reflects the welding state. These findings provide a theoretical basis for weld control and advance vision-based intelligent manufacturing welding techniques.

Reconfigurable intelligent surfaces (RISs) have tremendous potential to boost communication performance, especially when the line-of-sight (LOS) path between the user equipment (UE) and base station (BS) is blocked. To control the RIS, channel state information (CSI) is needed, which entails significant pilot overhead. To reduce this overhead and the need for frequent RIS reconfiguration, we propose a novel framework for integrated localization and communications, where RIS configurations are fixed during location coherence intervals, while BS precoders are optimized every channel coherence interval. This framework leverages accurate location information obtained with the aid of several RISs as well as novel RIS optimization and channel estimation methods. Performance in terms of localization accuracy, channel estimation error, and achievable rate demonstrates the effectiveness of the proposed approach.

Next generation cellular network is expected to provide the simultaneous high-accuracy localization and ultra-reliable communication services, even in high mobility scenarios. To that end, the novel orthogonal time frequency space (OTFS) modulation has been developed as a promising physical-layer transmission technique, evident by the outstanding performance in terms of robustness against time-frequency selective fading over the orthogonal frequency division multiplexing (OFDM) counterpart. However, when OTFS meets massive multiple-input multiple-output (MIMO), the specific conditions, under which the delay-Doppler (DD) domain channel model holds, are not identified. In addition, the channel estimation and localization performance in such system is rarely studied. In this work, we target at these new challenges, and conduct comprehensive modelling, performance analysis, and algorithm design for massive MIMO-OTFS based simultaneous localization and communications. Specifically, we derive new channel models for the massive MIMO-OTFS system, which captures both time-frequency dispersion and spatial wideband effects. The specific conditions, under which the new models hold has been unveiled as well. Based on the new models, we establish the theoretical foundations for channel estimation and localization, by deriving the Cramér-Rao lower bounds of channel parameter and location estimation errors. Such bounds have been achieved with the newly designed low-complexity channel estimation and localization algorithms. Numerical simulations of the proposed framework with prevailing pulse functions are also conducted and the results validate the proposed designs and analysis.

The keyhole welding process in Variable Polarity Plasma Arc Welding enhances weld quality significantly, yet it introduces pool instability. Dynamic stability is pursued by investigating molten metal flowing within keyholes and their characteristics. Weld pool flow patterns are obtained via particle tracking, while instability characteristics are captured employing a high-speed camera. Analysing directional molten metal flow unveils Convergence and Separation Points in weld pool flow. The latter’s displacement induces weld pool instability, resulting in an increase in keyhole area and a reduction in the pinch angle. The keyhole area signifies pool instability, while the rear wall angle reflects the welding state. These findings provide a theoretical basis for weld control and advance vision-based intelligent manufacturing welding techniques.

Objective: To evaluate the efficacy and safety of microwave ablation (MWA) plus ethanol ablation (EA) for different types of benign mixed thyroid nodules. Methods: A total of 81 patients with 81 benign mixed thyroid nodules were enrolled into the study; 39 were divided to the MWA group and 42 to the combined group (MWA combined with EA). Nodule ablation rate, volume reduction rate (VRR) and surgical complications of all patients were analyzed before and after treatment. Results: The mean ablation rate were 86.49 ± 6.68% and 90.09 ± 5.79% in the microwave and combined groups respectively, and the ablation rate of nodule decreased as the nodule volume increased. For nodules ≥15 ml in volume, the mean ablation rate of the combined group was higher than that of the microwave group (all P< 0.05). The mean VRR at 12 months postoperatively was 89.58 ± 4.32% in the microwave group and 92.92 ± 3.49% in the combined group, showing statistical significantly different between both arms (P= 0.001). The combined group decreased in volume more significantly than the microwave group for nodules with 20–50% or 50–80% cystic proportions or >15 ml in volume (all P< 0.05). The complication rate was 23.08% and 2.38% respectively. Conclusion: MWA combined with EA is more effective than MWA for treating mixed thyroid nodules. MWA combined with EA may be the first approach for nodules with >20% cystic proportions or volume >15 ml.

The existence of organic salts in hypersaline wastewater enlarges the difficulty of wastewater treatment. In this study, a real hypersaline wastewater containing both organic and inorganic salts from the bifenthrin alcohol production processes was firstly neutralized to convert and release the organic salt to organic compound and inorganic salt, and then adsorbed by macroporous resins. The optimal operating conditions and adsorption mechanisms were investigated and analyzed through the wastewater treatment. The experimental results show that after the wastewater is neutralized with the naturally accompanied evaporation of resulted organic compound, removals of chemical oxygen demand (COD) and ammonia nitrogen (AN) can reach up to 22.7% and 36%, respectively. Thereafter the wastewater was adsorbed by macroporous resins, the highest total COD removal can only reach up to 65.9% for the single resin adsorption case, which is not enough for the inorganic salt recovery with a high purity. Whereas the removal of organic matter can be remarkably promoted by the sequentially coupled macroporous resin adsorption case. The highest total COD and AN removals can reach up to 93% and 100%, respectively, when the neutralized wastewater is adsorbed firstly by resin NKA-II and then by resin XAD-4. The adsorption isotherms of sequentially coupled resins of NKA-II and XAD-4 are both better fitted by Freundlich’s model and the adsorption processes can be well fitted by pseudo-second-order kinetic model.

This study investigates the underlying causes of Variable Polarity Plasma Arc Welding (VPPAW) spatial positional instability and its adverse impact on weld seam quality. Microstructural analysis reveals that the primary cause of poor transverse mechanical properties is the asymmetric distribution of grains. Through the study of heat and mass transfer in the molten pool, it was found that the asymmetric flow of molten metal under the influence of gravity is the main factor leading to uneven temperature distribution and asymmetric grain distribution in the weld pool. A novel approach based on a predefined temperature field is proposed to regulate the weld pool's stability and welding quality. The implementation of the predefined temperature field effectively improves VPPAW weld pool flow, leading to enhanced temperature distribution and grain size and distribution. These findings provide a theoretical foundation and valuable engineering recommendations for achieving high-quality spatial position welding in VPPAW.

Purpose: Postoperative surgical site infection in patients treated with lumbosacral fusion has usually been thought to be caused by perioperative contamination. With the proximity of these incisions to the perineum, this study sought to determine if contamination by gastrointestinal and/or urogenital flora should be considered as a major cause of this complication. Methods: We conducted a retrospective review of adults treated with open posterior lumbosacral fusions between 2014 and 2021 to identify common factors in deep postoperative infection and the nature of the infecting organisms. Cases of tumor, primary infection and minimally invasive surgery were excluded. Results: 489 eligible patients were identified, 20 of which required debridement deep to the fascia (4.1%). Mean age, operative time, estimated blood loss and levels fused were similar between both groups. The infected group had a significantly higher BMI. The mean time from primary procedure to debridement was 40.8 days. Four patients showed no growth, 3 showed Staphylococcussp. infection (Perioperative Inside–Out) requiring debridement at 63.5 days. Thirteen showed infection with intestinal or urogenital pathogens (Postoperative Outside–In) requiring debridement at 20.0 days. Postoperative Outside–In infections led to debridement 80.3 days earlier than Perioperative Inside–Out infections (p= 0.007). Conclusions: 65% of deep infections in patients undergoing open lumbosacral fusion were due to early contamination by pathogens associated with the gastrointestinal and/or urogenital tracts. These required earlier debridement than Staphylococcus sp. infections. There should be renewed focus on keeping these pathogens away from the incision during the early stages of wound healing.

Several cognitive processes, including instrumental behavior and working memory, are controlled by endocannabinoids acting on cannabinoid receptor 1 (CB1R) in the brain through retrograde and presynaptic inhibition of GABA or glutamate release. However, the temporal mechanisms underlying the control of these cognitive processes by CB1Rs remain largely unknown. Here, we have developed a light-sensitive CB1R chimera (optoCB1R) by replacing the intracellular domains of bovine rhodopsin with those of human CB1R. We demonstrated that light stimulation of optoCB1R triggered canonical CB1R signaling by inhibiting cAMP (but not cGMP or IP1) signaling and activating the MAPK pathway in vitro or in vivo. Moreover, light stimulation of optoCB1R in corticostriatal glutamatergic neurons could temporally inhibit excitatory postsynaptic currents (EPSCs) at the level of seconds. Importantly, transient (3 s) and “time-locked”, but not random, activation of optoCB1R signaling in corticostriatal neurons at the time of reward affected animal sensitivity to outcome devaluation and inhibited goal-directed behavior. However, prolonged (~30 min) but not transient (10 or 30 s) activation of astrocytic CB1R signaling in the hippocampus impaired working memory. Consequently, neuronal and astrocytic CB1R signaling differentially regulate working memory and goal-directed behavior through distinct temporal and cellular mechanisms. Ultimately, the pharmacological blockade of adenosine A2AR improved the neuronal and astrocytic CB1R-induced impairments in goal-directed behavior and working memory, possibly through modulation of EPSCs and c-Fos, respectively. Therefore, A2AR may represent a promising target for managing cognitive dysfunction resulting from the use of CB1R drugs.

It is important to identify atmospheric environmental drivers of childhood asthma because asthma is the most common chronic disease in children globally. We provided an overview of the impacts of exposure to atmospheric environmental factors (e.g., meteorological factors and air pollutants) on childhood asthma, based on a series of studies with the cutting-edge environmental epidemiological methodology in Shanghai, China. Overall, we found that the prevalence of asthma among the children aged 3–7 years had increased by approximately 7 fold, from 2.1% in 1990 to 14.6% in 2019. Most meteorological factors (i.e. daily mean temperature, temperature difference, air pressure, air pressure difference, precipitation, relative humidity, sunshine and wind speed) and air pollutants (PM10, PM2.5, NO2, SO2and O3) were significantly associated with childhood asthma (p < 0.05), but meteorological factors appeared to play more important roles than air pollutants in the occurrence of asthma exacerbations. We also found that temperature variability was significantly associated with the elevated relative risk of daily outpatient visits for childhood asthma (p < 0.05). Furthermore, we conducted a systematic review on climate change adaptation measures and childhood asthma and found that there were a number of adaptation measures proposed for childhood asthma in response to climate change, including vulnerability assessment, improving ventilation and heating, enhancing community education, developing forecast models, and early warning systems. However, the effectiveness of most adaptation measures, except for improving ventilation and heating in winter, have not been explored and quantified. Since asthma is sensitive to the variation of atmospheric environmental conditions, it is critical to develop and implement appropriate climate change mitigation and adaptation strategies as global heating becomes apparent.