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OBJECTIVE Achieving solid fusion of the lumbosacral junction continues to be a challenge in long-segment instrumentation to the sacrum. The purpose of this study was to test the condition of adding sacral anchors through an S1 alar screw (S1AS) and multirod construct relative to using S1 pedicle screws (S1PSs) alone with sacroiliac fixation in lumbosacral junction augmentation. METHODS Seven fresh-frozen human lumbar-pelvic spine cadaveric specimens were tested under nondestructive moments (7.5 Nm). The ranges of motion (ROMs) in extension, flexion, left and right lateral bending (LB), and axial rotation (AR) of instrumented segments (L3–S1); the lumbosacral region (L5–S1); and the adjacent segment (L2–3) were measured, and the axial construct stiffness (ACS) was recorded. The testing conditions were 1) intact; 2) bilateral pedicle screw (BPS) fixation at L3–S1 (S1PS alone); 3) BPS and unilateral S2 alar iliac screw (U-S2AIS) fixation; 4) BPS and unilateral S1AS (U-S1AS) fixation; 5) BPS and bilateral S2AIS (B-S2AIS) fixation; and 6) BPS and bilateral S1AS (B-S1AS) fixation. Accessory rods were used in testing conditions 3–6. RESULTS In all directions, the ROMs of L5–S1 and L3–S1 were significantly reduced in B-S1AS and B-S2AIS conditions, compared with intact and S1PS alone. There was no significant difference in reduction of the ROMs of L5–S1 between B-S1ASs and B-S2AISs. Greater decreased ROMs of L3–S1 in extension and AR were detected with B-S2AISs than with B-S1ASs. Both B-S1ASs and B-S2AISs significantly increased the ACS compared with S1PSs alone. The ACS of B-S2AISs was significantly greater than that of B-S1ASs, but with greater increased ROMs of L2–3 in extension. CONCLUSIONS Adding sacral anchors through S1ASs and a multirod construct was as effective as sacropelvic fixation in lumbosacral junction augmentation. The ACS was less than the sacropelvic fixation but with lower ROMs of the adjacent segment. The biomechanical effects of using S1ASs in the control of long-instrumented segments were moderate (better than S1PSs alone but worse than sacropelvic fixation). This strategy is appropriate for patients requiring advanced lumbosacral fixation, and the risk of sacroiliac joint violation can be avoided.

In this paper, we present a novel data-driven design method for the human-robot interaction (HRI) system, where a given task is achieved by cooperation between the human and the robot. The presented HRI controller design is a two-level control design approach consisting of a task-oriented performance optimization design and a plant-oriented impedance controller design. The task-oriented design minimizes the human effort and guarantees the perfect task tracking in the outer-loop, while the plant-oriented achieves the desired impedance from the human to the robot manipulator end-effector in the inner-loop. Data-driven reinforcement learning techniques are used for performance optimization in the outer-loop to assign the optimal impedance parameters. In the inner-loop, a velocity-free filter is designed to avoid the requirement of end-effector velocity measurement. On this basis, an adaptive controller is designed to achieve the desired impedance of the robot manipulator in the task space. The simulation and experiment of a robot manipulator are conducted to verify the efficacy of the presented HRI design framework.

This study is the first to reveal the differential effects of different species of planktonic bacteria on fish kairomone-induced defense traits and energy redistribution in Daphnia . Our results not only help deepen the understanding of Daphnia ’s inducible defenses in environments containing a variety of bacteria but also provide insights into the energy reallocation involved in anti-predator defenses.

Road extraction from high‐resolution remote sensing images (HRSIs) has great importance in various practical applications. However, most existing road extraction methods have considerable limitation in capturing long‐range shape feature of road, and thus, they are ineffective in extracting road region under complex scenes. To address this issue, a novel model called long‐range context‐aware road extraction neural network (LR‐RoadNet) is proposed. LR‐RoadNet takes advantage of strip pooling to capture long‐range context from horizontal and vertical directions, aiming to improve continuity and completeness of road extraction results. Specifically, the LR‐RoadNet consists of two parts: strip residual module (SRM) and strip pyramid pooling module (SPPM). The SRM is built based on residual unit, in which the strip pooling is employed to learn general and long‐range road feature from input image. Then, the SPPM is used to obtain long‐range feature from multiple scales by multiple parallel strip pooling operations. More importantly, a structural similarity (SS) loss function is introduced to further explore road structure for optimizing LR‐RoadNet. The experimental results show that the proposed method achieves great improvement than other state‐of‐the‐art methods on three challenging datasets, Cheng‐Roads, Zimbabwe‐Roads and Mass‐Roads.

A growing number of studies on gnotobiotic animals have shown that the gut microbiota can promote host health by influencing life history traits. However, it is not clear whether the performance of host defense traits is related to the gut microbiota. In this study, we used Daphnia magna as a model organism to investigate the relationship between D. magna life history anti-predation defense traits and gut microbiota alterations under fish kairomone. Results showed that the Shannon diversity of D. magna gut microbiota under fish kairomone reduced significantly with the developmental stages. By analyzing the correlation between the induced anti-predation defense traits of D. magna and the relative abundance of bacteria, we found that the abundances of Comamonadaceae, Moraxellaceae, and Flavobacteriaceae were linearly correlated with the partial anti-predation defense traits of D. magna. Furthermore, the functional categories analysis showed that fish kairomone influenced the metabolic repertoire of D. magna gut microbiota. Our results highlighted that predation risk can simultaneously induce anti-predation defense and reshape gut microbiota composition of D. magna, and there was a complex correlation between the induced defensive traits and altered-microbiota. Such results revealed an important role of gut microbiota in the development of defensive traits of Daphnia.

Recently, discriminative machine learning (ML) models have been widely used to predict various attributes from Electron Backscatter Diffraction (EBSD) patterns. However, there has never been any generative model developed for EBSD pattern simulation. On one hand, the training of generative models is much harder than that of discriminative ones; On the other hand, numerous variables affecting EBSD pattern formation make the input space high-dimensional and its relationship with the distribution of backscattered electrons complicated. In this study, combining two famous generative models, we propose a framework (EBSD-CVAE/GAN) with great flexibility and scalability to realize parametric simulation of EBSD patterns. Compared with the frequently used forward model, EBSD-CVAE/GAN can take variables more than just orientation and generate corresponding EBSD patterns in a single run. The accuracy and quality of generated patterns are evaluated through multiple methods. The model developed does not only summarize a distribution of backscattered electrons at a higher level, but also offers a new idea of mitigating data scarcity in this field.

Accurate indexing of EBSD patterns presents a challenging problem. We propose a new convolutional neural network (EBSD-CNN) to realize real-time indexing of EBSD patterns; we implement a disorientation loss function to adapt a standard CNN model for crystallographic orientation indexing. The indexing accuracy, rate, and robustness against noise are evaluated using both simulated and experimental data, and compared with other indexing methods (Hough-based indexing, dictionary indexing, and spherical indexing). The results suggest that a CNN can provide an alternative to commercial Hough-transform-based indexing with comparative accuracy and rate. We obtain insight into the network functionality by visualization of selected filters.

Osteosarcoma (OS) therapy faces many challenges, especially the poor survival rate once metastasis occurs. Therefore, it is crucial to explore new OS treatment strategies that can efficiently inhibit OS metastasis. Bioactive nanoparticles such as zinc oxide nanoparticles (ZnO NPs) can efficiently inhibit OS growth, however, the effect and mechanisms of them on tumor metastasis are still not clear. In this study, we firstly prepared well-dispersed ZnO NPs and proved that ZnO NPs can inhibit OS metastasis-related malignant behaviors including migration, invasion, and epithelial-mesenchymal transition (EMT). RNA-Seqs found that differentially expressed genes (DEGs) in ZnO NP-treated OS cells were enriched in wingless/integrated (Wnt) and hypoxia-inducible factor-1 (HIF-1) signaling pathway. We further proved that Zn

In the past two decades, friction stir processing (FSP) technology has received considerable attention. FSP can be used to adjust and control the microstructure of materials, including eliminating defects, destroying dendrites and controlling fractions in the second stage, and is therefore widely used in titanium and its alloys for biomedical, aerospace and automotive applications. This article comprehensively reviews the methods of studying FSP, the microstructure evolution of materials and the summary of material properties. It begins with the introduction of the FSW system, characterization, structure and elemental analysis, and simulation and performance testing methods, and then introduces the microstructure evolution mechanism of various titanium materials and discusses in detail the material properties of titanium alloy, namely hardness and wear resistance, elasticity and plasticity, corrosion resistance and biocompatibility. Finally, this review presents unresolved issues and outstanding challenges in FSP technology and reveals the direction of this emerging field of research.

Background: Gut microbiota plays an important role in host physiology and fitness. The gut microbiota can promote host health by influencing life history traits, especially in arthropods. However, it is not clear whether the performance of host defense traits in response to predator pressure in natural food webs is related to their gut microbiota composition. In this study, we used Daphnia magna as a model organism to investigate the relationship of D. magna life history traits and gut microbiota alterations under predator kairomone based on 16S rRNA amplicon sequencing.Result: We showed that the microbiota composition of D. magna was significantly affected by their predator risk and development stage. The relative abundance of Comamonadaceae (mainly Limnohabitans sp.) significantly decreased in the presence of predator kairomone. Furthermore, the presence of predator kairomone significantly reduced the α diversity of gut microbiota in D. magna with the increase of instar. Among them, the OTUs belonged to Epsilonbacteraeota and Firmicutes in the presence of predator kairomone were significantly higher than those in the control group. The results of functional predictions showed that predation pressure promote the metabolic function of gut microbiota, such as metabolism of energy, cofactors, and vitamins. By analyzing the correlation between the induced defense traits of D. magna and the relative abundance of bacteria, we found that the increased abundance of Comamonadaceae, Moraxellaceae, and Flavobacteriaceae were linearly correlated with the partial defense traits of D. magna. Specifically speaking, body size was positively correlated with an increased abundance of Comamonadaceae, whereas spine length was negatively correlated with an increased abundance of Comamonadaceae but was positively correlated with increased Flavobacteriaceae abundance. Conclusions: Our results suggested that predation risk can affect the composition of the gut microbiota in D. magna, which may indirectly induce the production of defensive traits in D. magna. The results of this study revealed an important role of gut microbiota in the development of defensive traits of Daphnia in response to fish predators. The correlation between microbial abundance and defense traits is of great significance for further understanding the effect of host-microbiota interaction on individual anti-predation defense.

Host genotype and environment are considered crucial factors in shaping Daphnia gut microbiome composition. Among the environmental factors, diet is an important factor that regulates Daphnia microbiome. Most of the studies only focused on the use of axenic diet and non-sterile medium to investigate their effects on Daphnia microbiome. However, in natural environment, Daphnia diets such as phytoplankton are associated with microbes and could affect Daphnia microbiome composition and fitness, but remain relatively poorly understood compared to that of axenic diet. To test this, we cultured two Daphnia magna genotypes (genotype-1 and genotype-2) in sterile medium and fed with axenic diet. To check the effects of algal diet-associated microbes versus free water-related microbes, Daphnia were respectively inoculated with three different inoculums: medium microbial inoculum, diet-associated microbial inoculum, and medium and diet-mixed microbial inoculum. Daphnia were cultured for 3 weeks and their gut microbiome and life history traits were recorded. Results showed that Daphnia inoculated with medium microbial inoculum were dominated by Comamonadaceae in both genotypes. In Daphnia inoculated with mixed inoculum, genotype-1 microbiome was highly changed, whereas genotype-2 microbiome was slightly altered. Daphnia inoculated with diet microbial inoculum has almost the same microbiome in both genotypes. The total number of neonates and body size were significantly reduced in Daphnia inoculated with diet microbial inoculum regardless of genotype compared to all other treatments. Overall, this study shows that the microbiome of Daphnia is flexible and varies with genotype and diet- and medium-associated microbes, but not every bacteria is beneficial to Daphnia, and only symbionts can increase Daphnia performance.

In this article, a novel human-robot interaction (HRI) system is presented and applied in the robotic arm coordinated operation control task. The presented HRI system includes two parts, the impedance model controller and the robotic arm controller, which allows the operator to manipulate the robotic arm to accomplish the given task with minimal human effort. First, the model-based reinforcement learning (RL) method is applied in the impedance model for operator adaptation. The impedance model controller can transform human input into the specific signal for the manipulator. Second, a novel adaptive manipulator controller is designed. In contrast to existing controllers, a velocity-free filter is implemented in our controller, which is developed to replace the manipulator actuator’s speed signal. The effectiveness of the presented HRI system is verified by the simulation based on real manipulator parameters.

Decreasing elastic modulus and simultaneously improving biological compatibility has been a major challenge in developing biomedical alloy. In this study, Ti6Al4V/Zn composite with surface nano crystallization is successfully fabricated by friction stir processing (FSP) with simultaneous addition of beneficial Zn element. Nanoscale microstructures in surface region include nanoscaled Zn rich particles (including TiZn2), α nanograins, nanotwins and nano α + β lamellae. Dislocations slip and grain boundary sliding contribute much to the transformation of α-Ti nanograin, while dynamic overlapping of two partial dislocations is the main deformation mechanism for nanotwins. Interestingly, these nanoscale microstructures reduce the elastic modulus of this region.

Chenyuan Zhu,1,2,* Yuting Lv,3,4,* Chao Qian,1,2,* Zihao Ding,3,5 Ting Jiao,1,2 Xiaoyu Gu,1,2 Eryi Lu,6 Liqiang Wang,3 Fuqiang Zhang1,2 1Department of Prosthodontics, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 2Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, National Clinical Research Center of Stomatology, 3State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 4College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, People’s Republic of China; 5Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, USA; 6Department of Stomatology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: The interaction between the material and the organism affects the survival rate of the orthopedic or dental implant in vivo. Friction stir processing (FSP) is considered a new solid-state processing technology for surface modification. Purpose: This study aims to strengthen the surface mechanical properties and promote the osteogenic capacity of the biomaterial by constructing a Ti-6Al-4V (TC4)/zinc (Zn) surface nanocomposites through FSP. Methods: FSP was used to modify the surface of TC4. The microstructures and mechanical properties were analyzed by scanning electron microscopy, transmission electron microscopy, nanoindentation and Vickers hardness. The biological properties of the modified surface were evaluated by the in vitro and in vivo study. Results: The results showed that nanocrystalline and numerous β regions, grain boundary a phase, coarser acicular α phase and finer acicular martensite α' appeared because of the severe plastic deformation caused by FSP, resulting in a decreased elastic modulus and an increased surface hardness. With the addition of Zn particles and the enhancement of hydrophilicity, the biocompatibility was greatly improved in terms of cell adhesion and proliferation. The in vitro osteogenic differentiation of rat bone marrow stromal cells and rapid in vivo osseointegration were enhanced on the novel TC4/Zn metal matrix nanocomposite surface. Conclusion: These findings suggest that this novel TC4/Zn surface nanocomposite achieved by FSP has significantly improved mechanical properties and biocompatibility, in addition to promoting osseointegration and thus has potential for dental and orthopedic applications. Keywords: nanocomposite, friction stir processing, nanocrystalline/ultrafine grained, bone marrow stromal cells, cell proliferation, osteogenic differentiation

This work combines several techniques into a novel method to manufacture NiTi Nb layer-like porous structures with 3D interconnected channels, which are of vital importance in the biomedical field. NiTi wires and Nb foils are used herein to prepare NiTi Nb layer-like porous materials via in situ eutectic reaction. Microstructure, phase transformation and superelasticity of the resultant NiTi Nb layer-like porous material are analyzed and discussed, and the interface between NiTi wires and the solidified NiTi Nb eutectic region are also studied. Dislocations and stacking faults occurring at interfaces accelerate the eutectic phase transformation. Meanwhile, rod-like eutectic phase pins the motion of screw dislocations, which is beneficial for stress-induced R martensite nucleation. It is believed that much more superelastic recovery and elastic recovery for such a layer-like porous structure are attributed to formation of more martensites during deformation. Furthermore, both reorientation and subsequent de-twinning of type II twins result in the observed stress-plateau, thereby promoting the superelastic recovery.

As novel cross sections, aerodynamic behaviors and vortex-induced vibration (VIV) inducement of split box girders, especially split three-box girders, are not fully understood. Analysis of vortex-excited force (VEF) evolutionary characteristics in the VIV process may reveal valuable information. Based on displacement and pressure measurement wind tunnel tests on a large-scale section model, the evolutionary characteristics of typical VEF indexes were expounded. VIV was divided into four stages: pre-VIV, ascent, extreme point, and descent. At the extreme point, high-order harmonics were found, which indicates that VEF has obvious nonlinearities. Mean and RMS values of global VEF appear to be controlled by upstream and downstream boxes. An increase in RMS values is the main cause of VIV. VEF spanwise correlation is mainly dominated by structural vibration at the extreme point, while spanwise distance is dominant in other stages. Local aerodynamic forces on the surfaces include upstream box surface (excluding partial lower surfaces of the wind fairing), upstream and downstream curved surfaces in upstream gap, upper surface of downstream box, and the wake are the main contributors to global VEF and the main cause of VIV. This work provides a comprehensive understanding of aerodynamic behaviors and VIV inducement of split three-box girder bridges.

Although Ti-6Al-4V has been widely used in biomaterial field. Compared with other classes of materials, it still encounters some problems such as low surface hardness and relative low biocompatibility. To solve these problems friction stir processing (FSP) was applied to fabricate a nanosized composite layer of TiO2 and Ti-6Al-4V. Uniform distribution of TiO2 particles with some clusters on the surface of alloy can be observed. Due to severe plastic deformation and stirring heat, nanocrystallines and amorphous TiO2 can be observed in stir zone. FSPed samples show significant improvement in surface microhardness and biocompatibility due to its modified structure compared with original sample. In addition, through corrosion behaviors of the samples in simulated body fluid, it is found that FSP can enhance whilst TiO2 reduces the possibility and corrosion rate of material in environment of human body.

The shortage of low-sulfur coking coal will bring about an increasingly high hydrogen sulfide (H2S) in the coke oven gas (COG) in the near future. This work investigated the removal of hydrogen sulfide (H2S) from a simulated coke oven gas (COG) by catalytic oxidative absorption in a rotating packed bed (RPB). Sodium carbonate (Na2CO3) solution doped with 20 mg L−1 of a commercial “888” catalyst was used as the absorbent. The removal efficiency of H2S was evaluated under various operating conditions including rotation speed of the RPB (N), liquid-gas ratio (L/G), inlet H2S concentration ( c H 2 S,in ), temperature (T) and Na2CO3 concentration ( c Na 2 CO 3 ) in an attempt to optimize the conditions. The results were validated by comparison with those of separate experiments conducted in a packed column comprising a high-efficiency laboratory packing of Dixon rings. The comparison results reveal that the RPB exhibited higher H2S removal efficiency than the packed column, indicating it as an efficient gas-liquid contactor with a greater potential to remove H2S from COG.

In this work, a biomedical Ti-6Al-4V (TC4)/Zn composite with gradient microstructures was successfully prepared by friction stir processing (FSP). The microstructures and mechanical properties of the composite were systematically studied using scanning electron microscope (SEM), X-ray diffractometer (XRD), transmission electron microscope (TEM), atom probe tomography (APT), and microhardness test. The results show that TC4/Zn composite can be successfully prepared, and gradient microstructures varying from coarse grain to nanocrystalline is formed from the bottom to the upper surface. During FSP, adding Zn can accelerate the growth of &beta, phase region, and the grain size significantly increases with the increasing rotation rate. The grain combination is the main mechanism for grain growth of &beta, phase region. The deformation mechanisms gradually change from dislocation accumulations and rearrangement to dynamic recrystallization from the bottom to the upper surface (1.5 mm&ndash, 150 &mu, m from the upper surface). The composite exhibits slightly higher microhardness compared with the matrix. This paper provides a new method to obtain a TC4/Zn composite with gradient surface microstructures for potential applications in the biomedical field.