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Abstract The target scattering characteristics in microwave band are necessary to be researched for Orbital‐Angular‐Momentum (OAM) wave‐based radar applications. A theoretical description of electromagnetic (EM) scattering from a typical target by OAM waves is proposed in this paper. First, OAM waves are decomposed into plane waves in the spectral domain with different elevation and azimuth angles. Then, the scattering form of each decomposed plane wave is determined through coordinate system transformation and physical optics approximation. Formulas and numerical results are presented for OAM‐based radar scattering cross section of a perfect electric conductor and dielectric plate and a cylinder. Unlike the conventional results of EM plane wave scattering, the scattering properties of OAM waves from plate and cylinder are analysed with particular emphasis on OAM mode influence. The results provide insights into OAM wave‐matter interactions and may find important applications in wave propagation and OAM wave‐based radar detection and imaging.

This paper uses the super-efficiency SBM model to measure the green economic efficiency considering undesired output and analyzes the spatial distribution difference of green economic efficiency; secondly, the nonlinear panel threshold model is used to empirically study the nonlinear relationship between environmental regulations and green economic efficiency, and further analyzed the threshold effect of environmental regulations on the efficiency of green economy and concluded as follows. (1) The green economy efficiency index in the eastern region is mostly more significant than 1, and the green economy efficiency in most provinces in the eastern region has improved. These provinces have higher regional production levels and less environmental pollution. The green economy efficiency of the central region is second only to the eastern region. The green economy efficiency of provinces in the western region except Chongqing is less than 1, indicating that these provinces have insufficient regional production, severe environmental pollution, or extensive resource depletion. (2) The impact of environmental regulations on the efficiency of the green economy presents an inverted “U” shape, with a threshold of 0.5128 for environmental regulations. The impact of the industrial structure on the efficiency of the green economy changes from inhibition to promotion after crossing the threshold of the intensity of environmental regulation, and the degree of opening to the outside world has a complementary effect on the efficiency of the green economy. The impact of urbanization on the efficiency of the green economy changes from promotion to suppression after surpassing the threshold of the intensity of environmental regulations.

Abstract Controllable construction of diversiform topological morphologies through supramolecular self‐assembly on the basis of single building block is of vital importance, but still remains a big challenge. Herein, a bola‐type supra‐amphiphile, namely DAdDMA@2β‐CD, is rationally designed and successfully prepared by typical host–guest binding β‐cyclodextrin units with an aggregation‐induced emission (AIE)‐active scaffold DAdDMA. Self‐assembling investigation reveals that several morphologies of self‐assembled DAdDMA@2β‐CD including leaf‐like lamellar structure, nanoribbons, vesicles, nanofibers, helical nanofibers, and toroids, can be straightforwardly fabricated by simply manipulating the self‐assembling solvent proportioning and/or temperature. To the best of knowledge, this presented protocol probably holds the most types of self‐assembling morphology alterations using a single entity. Moreover, the developed leaf‐like lamellar structure performs well in mimicking the light‐harvesting antenna system by incorporating with a Förster resonance energy transfer acceptor, providing up to 94.2% of energy transfer efficiency.

Fund investment is a hot issue in today’s society. How to choose a project for investment is affected by many factors. In view of this problem, this paper starts from the granular computing point of view and combines the multigranulation rough set decision-making method to construct a fund investment decision information system; then, the fund investment decision information system is reduced under different thresholds, and the decision rules are extracted through reduction. And from the aspects of decision accuracy and rule accuracy, the rules are analyzed. Finally, decision rules are used to give the decision of the fund investment project. This study provides a new approach to fund management.

Objective The current investigation sought to utilize finite element analysis to replicate the biomechanical effects of different fixation methods, with the objective of establishing a theoretical framework for the optimal choice of modalities in managing Pauwels type III femoral neck fractures. Methods The Pauwels type III fracture configuration, characterized by angles of 70°, was simulated in conjunction with six distinct internal fixation methods, including cannulated compression screw (CCS), dynamic hip screw (DHS), DHS with de‐rotational screw (DS), CCS with medial buttress plate (MBP), proximal femoral nail anti‐rotation (PFNA), and femoral neck system (FNS). These models were developed and refined using Geomagic and SolidWorks software. Subsequently, finite element analysis was conducted utilizing Ansys software, incorporating axial loading, torsional loading, yield loading and cyclic loading. Results Under axial loading conditions, the peak stress values for internal fixation and the femur were found to be highest for CCS (454.4; 215.4 MPa) and CCS + MBP (797.2; 284.2 MPa), respectively. The corresponding maximum and minimum displacements for internal fixation were recorded as 6.65 mm for CCS and 6.44 mm for CCS + MBP. When subjected to torsional loading, the peak stress values for internal fixation were highest for CCS + MBP (153.6 MPa) and DHS + DS (72.8 MPa), while for the femur, the maximum and minimum peak stress values were observed for CCS + MBP (119.3 MPa) and FNS (17.6 MPa), respectively. Furthermore, the maximum and minimum displacements for internal fixation were measured as 0.249 mm for CCS + MBP and 0.205 mm for PFNA. Additionally, all six internal fixation models showed excellent performance in terms of yield load and fatigue life. Conclusion CCS + MBP had the best initial mechanical stability in treatment for Pauwels type III fracture. However, the MBP was found to be more susceptible to shear stress, potentially increasing the risk of plate breakage. Furthermore, the DHS + DS exhibited superior biomechanical stability compared to CCS, DHS, and PFNA, thereby offering a more conducive environment for fracture healing. Additionally, it appeared that FNS represented a promising treatment strategy, warranting further validation in future studies.

Abstract It is important to study the effect of hydrate production on the physical and mechanical properties of low‐permeability clayey–silty reservoirs for the large‐scale exploitation of hydrate reservoirs in the South China Sea. In this study, a multiphysical‐field coupling model, combined with actual exploration drilling data and the mechanical experimental data of hydrate cores in the laboratory, was established to investigate the physical and mechanical properties of low‐permeability reservoirs with different slope angles during 5‐year hydrate production by the depressurization method via a horizontal well. The result shows that the permeability of reservoirs severely affects gas production rate, and the maximum gas production amount of a 20‐m‐long horizontal well can reach 186.8 m3/day during the 5‐year hydrate production. Reservoirs with smaller slope angles show higher gas production rates. The depressurization propagation and hydrate dissociation mainly develop along the direction parallel to the slope. Besides, the mean effective stress of reservoirs is concentrated in the near‐wellbore area with the on‐going hydrate production, and gradually decreases with the increase of the slope angle. Different from the effective stress distribution law, the total reservoir settlement amount first decreases and then increases with the increase of the slope angle. The maximum settlement of reservoirs with a 0° slope angle is up to 3.4 m, and the displacement in the near‐wellbore area is as high as 2.2 m after 5 years of hydrate production. It is concluded that the pore pressure drop region of low‐permeability reservoirs in the South China Sea is limited, and various slope angles further lead to differences in effective stress and strain of reservoirs during hydrate production, resulting in severe uneven settlement of reservoirs.

Abstract Objective To investigate the prognostic factors of patients with anti‐melanoma differentiation‐associated gene 5 (MDA5) positive clinically amyopathic dermatomyositis (CADM) and interstitial lung disease (ILD). Methods A retrospective analysis was conducted on clinical data of 125 patients with anti‐MDA5 + CADM‐ILD collected from 10 branches in eastern China between December 2014 and December 2022. Prognostic factors were analyzed using χ2 test, Log‐rank test, COX and logistic regression analysis. Results In this cohort, 125 anti‐MDA5 + CADM‐ILD patients exhibited a rapidly progressive interstitial lung disease (RPILD) incidence of 37.6%, and an overall mortality rate of 24.8%. One patient was lost to follow‐up. After diagnosis of RPILD, a mortality rate of 53.2% occurred in patients died within 3 months, and that of 5.6% appeared in those who survived for more than 3 months. Multiple factor analysis revealed that C‐reactive protein (CRP) ≥ 10 mg/L (p = 0.01) and recombinant human tripartite motif containing 21 (Ro52) (+) (p = 0.003) were associated with a higher risk of RPILD in anti‐MDA5 + CADM‐ILD patients; CRP ≥ 10 mg/L (p = 0.018) and the presence of RPILD (p = 0.003) were identified as the factors influencing survival time in these patients, while arthritis was the protective factor (p = 0.016). Conclusion Patients with anti‐MDA5 + CADM‐ILD will have a higher mortality rate, and the initial 3 months after diagnosis of RPILD is considered the risk window for the dismal prognosis. Patients with CRP ≥ 10 mg/L, Ro52 (+) and RPILD may be related to a shorter survival time, while patients complicated with arthritis may present with relatively mild conditions.

Abstract Sesquiterpenes have been identified as promising ingredients for aviation fuels due to their high energy density and combustion heat properties. Despite the characterization of numerous sesquiterpene structures, studies testing their performance properties and feasibility as fuels are scarce. In this study, 122 sesquiterpenoid skeleton compounds, obtained from existing literature reports, are tested using group contribution and gaussian quantum chemistry methods to assess their potential as high‐energy aviation fuels. Seventeen sesquiterpene compounds exhibit good predictive performance and nine compounds are further selected for overproduction in yeast. Through fed‐batch fermentation, all compounds achieve the highest reported titers to date. Subsequently, three representative products, pentalenene, presilphiperfol‐1‐ene, and α‐farnesene, are selected, produced, purified in large quantities, and tested for use as potential fuels. The performance of pentalenene, presilphiperfol‐1‐ene, and their derivatives reveals favorable prospects as high‐energy aviation fuels.

The physical and mechanical parameters and degradation mechanisms of red sandstone in the Mount Wuyi scenic area were studied under the action of dry–wet cycles. Dry–wet cycle, acoustic wave velocity, water saturation rate, and triaxial compression tests were conducted, aided by scanning electron microscopy and X-ray diffraction testing techniques. The study’s results show that the dry–wet cycle effect on red sandstone is a major factor in the degradation of its physical and mechanical parameters and that its microstructural characteristics are significantly affected. The P-wave velocity, peak strength, elastic modulus, internal friction angle, and cohesion decreased, the water content and peak strain increased, and the elastic modulus was the most sensitive to dry–wet cycles. A dry–wet cycle’s action severely damages the microstructural integrity of the red sandstone. After 15 dry–wet cycles, the interstitial fillings between the skeletal grains are dissolved over a large area, microfractures are interwoven throughout, and the structure is severely fragmented. The microstructural degradation of the red sandstone by dry–wet cycles mainly manifests in the dissolution of the interstitial filler, and the relative content of calcite as an interstitial filler is reduced by 46.6% after 15 dry–wet cycles. The proposed strength decay prediction equation has reference significance for the strength prediction of the red sand conglomerate in the project. This study’s results can provide theoretical support for the landscape protection of rock masses and the prevention of engineering geological hazards.

This article conducted acoustic emission tests of natural coal, natural frozen coal, and saturated frozen coal to explore the damage characteristics of frozen coal and in view of the frozen coal damage early warning problems and explored the strength deformation and acoustic emission characteristics of coal samples. The test results showed that the compressive strength of the frozen coal samples decreased significantly, and the strength of the saturated frozen coal samples was the lowest; more acoustic emissions were generated at the initial loading stage. The damage parameters were defined using the acoustic emission parameters. The damage characteristics of the coal samples were analyzed. The damage model of the coal samples was established based on the power function. The early warning parameter VAEi to analyze the evolution characteristics of the variance curve was proposed; the sudden jump point b of VAEi from the stable development stage to the rapid growth stage was defined as a general early warning point; the endpoint point c of the parameter rapid growth stage was defined as a key early warning point; a zonal and hierarchical early warning was finally proposed.

Abstract Doping perovskite oxide with different cations is used to improve its electro‐catalytic performance for various energy and environment devices. In this work, an activated lattice oxygen activity in Pr0.4Sr0.6CoxFe0.9−xNb0.1O3−δ (PSCxFN, x = 0, 0.2, 0.7) thin film model system by B‐site cation doping is reported. As Co doping level increases, PSCxFN thin films exhibit higher concentration of oxygen vacancies (Vo••) as revealed by X‐ray diffraction and synchrotron‐based X‐ray photoelectron spectroscopy. Density functional theory calculation results suggest that Co doping leads to more distortion in FeO octahedra and weaker metaloxygen bonds caused by the increase of antibonding state, thereby lowering Vo•• formation energy. As a consequence, PSCxFN thin film with higher Co‐doping level presents larger amount of exsolved particles on the surface. Both the facilitated Vo•• formation and B‐site cation exsolution lead to the enhanced hydrogen oxidation reaction (HOR) activity. Excessive Co doping until 70%, nevertheless, results in partial decomposition of thin film and degrades the stability. Pr0.4Sr0.6(Co0.2Fe0.7Nb0.1)O3 with moderate Co doping level displays both good HOR activity and stability. This work clarifies the critical role of B‐site cation doping in determining the Vo•• formation process, the surface activity, and structure stability of perovskite oxides.

Objective To compare the clinical therapeutic effect of transverse cancellous lag screw (TCLS) fixations and ordinary cannulated screw (OCS) fixations for vertical femoral neck fractures. Methods A total of 62 eligible patients with an average age of 56.2 years (range, 19–45 years; 40 male and 22 female) with Pauwels’ type III femoral neck fractures were recruited in our study from January 2016 to December 2017. Among the patients, 30 underwent TCLS fixation (TCLS group), and the others were treated with OCS fixation (OCS group). The baseline data, perioperative outcomes (operative time, intra‐operative blood loss, reduction quality, and hospital time), postoperative outcomes evaluated by a variety of scales including visual analogue scale (VAS) score, EuroQol five dimensions questionnaire (EQ‐5D) and Harris hip scores (HHS), and complications (nonunion, femoral head necrosis, femoral neck shortening, and failure of fixation) of the two groups were recorded to compare at 12‐month follow‐up. Results The mean follow‐up time of included patients was 13.4 ± 1.6 months in the TCLS group and 13.7 ± 0.9 months in the OCS group. There was no statistically significant difference in the baseline data as well as perioperative outcomes, including operative time, intra‐operative blood loss, the hemoglobin difference before and after treatment, quality of reduction, and hospital time between two groups. Likewise, the VAS score, the EQ‐5D score, and complications rates including nonunion and femoral head necrosis had no distinct difference in two groups. However, HHS in the TCLS group were superior to those in the OCS group at 12‐month follow‐up, and the femoral neck shortening rate was prominently reduced in the TCLS group when compared with the OCS group. Conclusions Treating vertical femoral neck fractures with the TCLS technique could significantly improve hip functional recovery and reduce the postoperative femoral neck shortening rate. The present study provides novel insight for the treatment of vertical femoral neck fractures.

Abstract The dramatic climate fluctuations of the late Quaternary have influenced the diversity and composition of macroorganism communities, but how they structure belowground microbial communities is less well known. Fungi constitute an important component of soil microorganism communities. They play an important role in biodiversity maintenance, community assembly, and ecosystem functioning, and differ from many macroorganisms in many traits. Here, we examined soil fungal communities in Chinese temperate, subtropical, and tropic forests using Illumina MiSeq sequencing of the fungal ITS1 region. The relative effect of late Quaternary climate change and contemporary environment (plant, soil, current climate, and geographic distance) on the soil fungal community was analyzed. The richness of the total fungal community, along with saprotrophic, ectomycorrhizal (EM), and pathogenic fungal communities, was influenced primarily by the contemporary environment (plant and/or soil) but not by late Quaternary climate change. Late Quaternary climate change acted in concert with the contemporary environment to shape total, saprotrophic, EM, and pathogenic fungal community compositions and with a stronger effect in temperate forest than in tropic–subtropical forest ecosystems. Some contemporary environmental factors influencing total, saprotrophic, EM, and pathogenic fungal communities in temperate and tropic–subtropical forests were different. We demonstrate that late Quaternary climate change can help to explain current soil fungal community composition and argue that climatic legacies can help to predict soil fungal responses to climate change.

Tissue engineering (TE) has brought new hope for articular cartilage regeneration, as TE can provide structural and functional substitutes for native tissues. The basic elements of TE involve scaffolds, seeded cells, and biochemical and biomechanical stimuli. However, there are some limitations of TE; what most important is that static cell culture on scaffolds cannot simulate the physiological environment required for the development of natural cartilage. Recently, bioreactors have been used to simulate the physical and mechanical environment during the development of articular cartilage. This review aims to provide an overview of the concepts, categories, and applications of bioreactors for cartilage TE with emphasis on the design of various bioreactor systems.

The RNA-binding protein Lin28 regulates neurogliogenesis in mammals, independently of the let-7 microRNA. However, the detailed regulatory mechanism remains obscured. Here, we established Lin28a or Lin28b overexpression mouse embryonic stem cells (ESCs) and found that these cells expressed similar levels of the core pluripotent factors, such as Oct4 and Sox2, and increased Yap1 but decreased lineage-specific markers compared to the control ESCs. Further differentiation of these ESCs to neuronal and glial lineage cells revealed that Lin28a/b overexpression did not affect the expression of neuronal marker βIII-tubulin, but dramatically inhibited the glial lineage markers, such as Gfap and Mbp. Interestingly, overexpression of Yap1 in mouse ESCs phenocopied Lin28a/b overexpression ESCs by showing defect in glial cell differentiation. Inhibition of Yap1/Tead-mediated transcription with verteporfin partially rescued the differentiation defect of Lin28a/b overexpression ESCs. Mechanistically, we demonstrated that Lin28 can directly bind to Yap1 mRNA, and the induction of Yap1 by Lin28a in mESCs is independent of Let7. Taken together, our results unravel a novel Lin28-Yap1 regulatory axis during mESC to glial lineage cell differentiation, which may shed light on glial cell generation in vitro.

Injury of articular cartilage can cause osteoarthritis and seriously affect the physical and mental health of patients. Unfortunately, current surgical treatment techniques that are commonly used in the clinic cannot regenerate articular cartilage. Regenerative medicine involving stem cells has entered a new stage and is considered the most promising way to regenerate articular cartilage. In terms of theories on the mechanism, it was thought that stem cell-mediated articular cartilage regeneration was achieved through the directional differentiation of stem cells into chondrocytes. However, recent evidence has shown that the stem cell secretome plays an important role in biological processes such as the immune response, inflammation regulation, and drug delivery. At the same time, the stem cell secretome can effectively mediate the process of tissue regeneration. This new theory has attributed the therapeutic effect of stem cells to their paracrine effects. The application of stem cells is not limited to exogenous stem cell transplantation. Endogenous stem cell homing and in situ regeneration strategies have received extensive attention. The application of stem cell derivatives, such as conditioned media, extracellular vesicles, and extracellular matrix, is an extension of stem cell paracrine theory. On the other hand, stem cell pretreatment strategies have also shown promising therapeutic effects. This article will systematically review the latest developments in these areas, summarize challenges in articular cartilage regeneration strategies involving stem cells, and describe prospects for future development.

Articular cartilage is susceptible to damage, but its self-repair is hindered by its avascular nature. Traditional treatment methods are not able to achieve satisfactory repair effects, and the development of tissue engineering techniques has shed new light on cartilage regeneration. Mesenchymal stem cells (MSCs) are one of the most commonly used seed cells in cartilage tissue engineering. However, MSCs tend to lose their multipotency, and the composition and structure of cartilage-like tissues formed by MSCs are far from those of native cartilage. Thus, there is an urgent need to develop strategies that promote MSC chondrogenic differentiation to give rise to durable and phenotypically correct regenerated cartilage. This review provides an overview of recent advances in enhancement strategies for MSC chondrogenic differentiation, including optimization of bioactive factors, culture conditions, cell type selection, coculture, gene editing, scaffolds, and physical stimulation. This review will aid the further understanding of the MSC chondrogenic differentiation process and enable improvement of MSC-based cartilage tissue engineering.

Animal models play an important role in preclinical studies, especially in tissue engineering scaffolds for cartilage repair, which require large animal models to verify the safety and effectiveness for clinical use. The small ruminant models are most widely used in this field than other large animals because they are cost-effective, easy to raise, not to mention the fact that the aforementioned animal presents similar anatomical features to that of humans. This review discusses the experimental study of tissue engineering scaffolds for knee articular cartilage regeneration in small ruminant models. Firstly, the selection of these scaffold materials and the preparation process in vitro that have been already used in vivo are briefly reviewed. Moreover, the major factors influencing the rational design and the implementation as well as advantages and limitations of small ruminants are also demonstrated. As regards methodology, this paper applies principles and methods followed by most researchers in the process of experimental design and operation of this kind. By summarizing and comparing different therapeutic concepts, this paper offers suggestions aiming to increase the effectiveness of preclinical research using small ruminant models and improve the process of developing corresponding therapies.

Hyaline articular cartilage lacks blood vessels, lymphatics, and nerves and is characterised by limited self-repair ability following injury. Traditional techniques of articular cartilage repair and regeneration all have certain limitations. The development of tissue engineering technology has brought hope to the regeneration of articular cartilage. The strategies of tissue-engineered articular cartilage can be divided into three types: “cell-scaffold construct,” cell-free, and scaffold-free. In “cell-scaffold construct” strategies, seed cells can be autologous chondrocytes or stem. Among them, some commercial products with autologous chondrocytes as seed cells, such as BioSeed®-C and CaReS®, have been put on the market and some products are undergoing clinical trials, such as NOVOCART® 3D. The stem cells are mainly pluripotent stem cells and mesenchymal stem cells from different sources. Cell-free strategies that indirectly utilize the repair and regeneration potential of stem cells have also been used in clinical settings, such as TruFit and MaioRegen. Finally, the scaffold-free strategy is also a new development direction, and the short-term repair results of related products, such as NOVOCART® 3D, are encouraging. In this paper, the commonly used techniques of articular cartilage regeneration in surgery are reviewed. By studying different strategies and different seed cells, the clinical application status of tissue-engineered articular cartilage is described in detail.

In this study, a case-based diagnostic model of a power transformer for oil chromatography is proposed. A nonlinear normalised mapping method is proposed for achieving ideal distribution characteristics of oil chromatogram gas in the case base. A similarity degree algorithm is proposed to calculate the similarity degree in the target spatial domain between the case to be diagnosed and the cases in the case base. A threshold method is proposed to determine the number of similar cases. Also, a method for calculating the weight of the diagnosis result according to the case distribution in the case base is proposed. The diagnostic method proposed is used to deploy the diagnostic system on the Internet. Defeat diagnosis conclusions of two transformers by the method and system in this paper are consistent with the disintegration results. It can be concluded that the proposed method has important practical application value in engineering.

Seed cells of articular cartilage tissue engineering face many obstacles in their application because of the dedifferentiation of chondrocytes or unstable chondrogenic differentiation status of pluripotent stem cells. To overcome mentioned dilemmas, a simulation of the articular cartilage microenvironment was constructed by primary articular cartilage cells (pACs) and acellular cartilage extracellular matrix- (ACECM-) oriented scaffold cocultured with human umbilical cord Wharton’s jelly-derived mesenchymal stem cells (hWJMSCs) in vitro. The coculture groups showed more affluent cartilage special matrix ingredients including collagen II and aggrecan based on the results of histological staining and western blotting and cut down as many pACs as possible. The RT-PCR and cell viability experiments also demonstrated that hWJMSCs were successfully induced to differentiate into chondrocytes when cultured in the simulated cartilage microenvironment, as confirmed by the significant upregulation of collagen II and aggrecan, while the cell proliferation activity of pACs was significantly improved by cell-cell interactions. Therefore, compared with monoculture and chondrogenic induction of inducers, coculture providing a simulated native articular microenvironment was a potential and temperate way to regulate the biological behaviors of pACs and hWJMSCs to regenerate the hyaline articular cartilage.

Articular cartilage lacks a blood supply and nerves. Hence, articular cartilage regeneration remains a major challenge in orthopedics. Decellularized extracellular matrix- (ECM-) based strategies have recently received particular attention. The structure of native cartilage exhibits complex zonal heterogeneity. Specifically, the development of a tissue-engineered scaffold mimicking the aligned structure of native cartilage would be of great utility in terms of cartilage regeneration. Previously, we fabricated oriented PLGA/ACECM (natural, nanofibrous, articular cartilage ECM) composite scaffolds. In vitro, we found that the scaffolds not only guided seeded cells to proliferate in an aligned manner but also exhibited high biomechanical strength. To detect whether oriented cartilage regeneration was possible in vivo, we used mesenchymal stem cell (MSC)/scaffold constructs to repair cartilage defects. The results showed that cartilage defects could be completely regenerated. Histologically, these became filled with hyaline cartilage and subchondral bone. Moreover, the aligned structure of cartilage was regenerated and was similar to that of native tissue. In conclusion, the MSC/scaffold constructs enhanced the structure-specific regeneration of hyaline cartilage in a rabbit model and may be a promising treatment strategy for the repair of human cartilage defects.

The meniscus plays a vital role in protecting the articular cartilage of the knee joint. The inner two-thirds of the meniscus are avascular, and injuries to this region often fail to heal without intervention. The use of tissue engineering and regenerative medicine techniques may offer novel and effective approaches to repairing meniscal injuries. Meniscal tissue engineering and regenerative medicine typically use one of two techniques, cell-based or cell-free. While numerous cell-based strategies have been applied to repair and regenerate meniscal defects, these techniques possess certain limitations including cellular contamination and an increased risk of disease transmission. Cell-free strategies attempt to repair and regenerate the injured tissues by recruiting endogenous stem/progenitor cells. Cell-free strategies avoid several of the disadvantages of cell-based techniques and, therefore, may have a wider clinical application. This review first compares cell-based to cell-free techniques. Next, it summarizes potential sources for endogenous stem/progenitor cells. Finally, it discusses important recruitment factors for meniscal repair and regeneration. In conclusion, cell-free techniques, which focus on the recruitment of endogenous stem and progenitor cells, are growing in efficacy and may play a critical role in the future of meniscal repair and regeneration.

The histological features of cartilage call attention to the fact that cartilage has a little capacity to repair itself owing to the lack of a blood supply, nerves, or lymphangion. Stem cells have emerged as a promising option in the field of cartilage tissue engineering and regenerative medicine and could lead to cartilage repair. Much research has examined cartilage regeneration utilizing stem cells. However, both the potential and the limitations of this procedure remain controversial. This review presents a summary of emerging trends with regard to using stem cells in cartilage tissue engineering and regenerative medicine. In particular, it focuses on the characterization of cartilage stem cells, the chondrogenic differentiation of stem cells, and the various strategies and approaches involving stem cells that have been used in cartilage repair and clinical studies. Based on the research into chondrocyte and stem cell technologies, this review discusses the damage and repair of cartilage and the clinical application of stem cells, with a view to increasing our systematic understanding of the application of stem cells in cartilage regeneration; additionally, several advanced strategies for cartilage repair are discussed.

Wireless smart home system is to facilitate people's lives and it trends to adopt a more intelligent way to provide services. It is beneficial to design an intelligent smart home (SH) to precisely recognize users' behaviors and automatically responsd with the corresponding activities to satisfy users' actual demands. However, activity models in the existing approaches are usually constructed separately through statistic probability. These models cannot recognize the user's dynamical intentions accurately. To address the problem, we propose a new SH architecture with smart device enabled sensor networks and develop the prototype system. Moreover, we propose the hybrid semantic model based on the statistic probability model and the semantic association model, and an assistance algorithm is presented. In our prototype system, the smart devices are described by semantic models. When the user needs assistance, smart gateway can provide appropriate services according to the inference results of the algorithm. The algorithm has been implemented and the results show that the accuracy of the algorithm based on the hybrid model is higher than the statistic probability model.

The meniscus plays a crucial role in maintaining knee joint homoeostasis. Meniscal lesions are relatively common in the knee joint and are typically categorized into various types. However, it is difficult for inner avascular meniscal lesions to self-heal. Untreated meniscal lesions lead to meniscal extrusions in the long-term and gradually trigger the development of knee osteoarthritis (OA). The relationship between meniscal lesions and knee OA is complex. Partial meniscectomy, which is the primary method to treat a meniscal injury, only relieves short-term pain; however, it does not prevent the development of knee OA. Similarly, other current therapeutic strategies have intrinsic limitations in clinical practice. Tissue engineering technology will probably address this challenge by reconstructing a meniscus possessing an integrated configuration with competent biomechanical capacity. This review describes normal structure and biomechanical characteristics of the meniscus, discusses the relationship between meniscal lesions and knee OA, and summarizes the classifications and corresponding treatment strategies for meniscal lesions to understand meniscal regeneration from physiological and pathological perspectives. Last, we present current advances in meniscal scaffolds and provide a number of prospects that will potentially benefit the development of meniscal regeneration methods.

Abstract Seed dispersal selection pressures may cause morphological differences in cone structure and seed traits of large‐seeded pine trees. We investigated the cone, seed, and scale traits of four species of animal‐dispersed pine trees to explore the adaptations of morphological structures to different dispersers. The four focal pines analyzed in this study were Chinese white pine (Pinus armandi), Korean pine (P. koraiensis), Siberian dwarf pine (P. pumila), and Dabieshan white pine (P. dabeshanensis). There are significant differences in the traits of the cones and seeds of these four animal‐dispersed pines. The scales of Korean pine and Siberian dwarf pine are somewhat opened after cone maturity, the seeds are closely combined with scales, and the seed coat and scales are thick. The cones of Chinese white pine and Dabieshan white pine are open after ripening, the seeds fall easily from the cones, and the seed coat and seed scales are relatively thin. The results showed that the cone structure of Chinese white pine is similar to that of Dabieshan white pine, whereas Korean pine and Siberian dwarf pine are significantly different from the other two pines and vary significantly from each other. This suggests that species with similar seed dispersal strategies exhibit similar morphological adaptions. Accordingly, we predicted three possible seed dispersal paradigms for animal‐dispersed pines: the first, as represented by Chinese white pine and Dabieshan white pine, relies upon small forest rodents for seed dispersal; the second, represented by Korean pine, relies primarily on birds and squirrels to disperse the seeds; and the third, represented by Siberian dwarf pine, relies primarily on birds for seed dispersal. Our study highlights the significance of animal seed dispersal in shaping cone morphology, and our predictions provide a theoretical framework for research investigating the coevolution of large‐seeded pines and their seed dispersers.

Several assays have been frequently used to estimate antioxidant capacities including ABTS•+, DPPH, and FRAP assays. Xanthohumol (XN), the major prenylated flavonoid contained in beer, witnessed various reports on its antioxidant capacity. We systematically evaluated the antioxidant activity of XN using three systems, 2,2,-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS•+) scavenging assays, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assays, and ferric reducing antioxidant power (FRAP) assays. The results are expressed as Trolox equivalent antioxidant capacity (TEAC). The TEAC of XN was 0.32±0.09 μmol·l−1 by the ABTS assay and 0.27±0.04 μmol·l−1 by the FRAP. Meanwhile, the XN did not show obviously scavenging effect on DPPH radical reaction system. These results showed that different methods in the evaluation of compound antioxidant capicity, there may be a different conclusion.

Purpose: The purpose of this study was to report the initial results of meniscus allograft transplantation after a 2-year follow-up period with second-look arthroscopy of 18 patients., Methods: Seven medial and 11 lateral meniscus allografts were evaluated with a median follow-up of 24.9 months (range, 18-41 months). The clinical outcome and failure rate were evaluated by use of second-look arthroscopy in all patients, magnetic resonance imaging (MRI) analysis in 17 patients, and standardized outcome scores assessment, including Lysholm score, Knee Injury, and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) on pain and satisfaction and International Knee Documentation Committee (IKDC) objective ratings in all patients. Patients were grouped into medial and lateral subgroups as well as those with isolated or combined procedures., Results: For the second-look arthroscopic findings, 6 meniscus transplants (33%) had normal characteristics, 10 (56%) had altered characteristics, and 2 (11%) failed. On MRI, two grafts had grade III signals and 11 showed partially extruded. Patients demonstrated statistically significant improvements in standardized outcome scores and VAS pain scales. Overall, 67% of the patients reported that they were completely or mostly satisfied with the procedure. There were no significant differences in the medial and lateral subgroups and no significant differences were noted in the isolated and combined subgroups., Conclusions: Arthroscopic meniscus transplantation can achieve satisfying subjective and objective clinical outcomes, with a failure rate of 11% after 1-3 years of follow-up, as documented by second-look arthroscopy.