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With two groups of numerical experiments with and without the cold-core eddy (CCE), the impacts of the CCE on the upper-ocean responses to Typhoon Trami (2018) were investigated using a coupled atmosphere–ocean model. It is commonly accepted that the CCE promotes the sea surface cooling (SSC) primally through the enhanced vertical mixing, while the contributions from the wind-driven advection and the near-inertial advection to the differences in the sea surface temperature (dSST) were underestimated. This study found that the presence of CCE contributed to the stronger along-track cold advection, which dominated the increase in the SSC near the radius of maximum wind (RMW) to the right of Trami’s track, and the stronger cross-track warm advection was acting to prevent the cooling induced by the vertical mixing. During the relaxation stage, the stronger near-inertial advection within the CCE accounted largely for the amplification and the redistribution of the dSST. As for the dynamic responses, the enhanced upwelling and downwelling within the CCE explained the larger cooling and warming in the subsurface temperature oscillations. The wind-driven acceleration of the currents in the mixing layer was larger during the typhoon–eddy interaction so that the CCE became an efficient mixer, thus contributing to the rapid surfacing of the cold water and the ensuing stronger wind-driven advection. These results highlight the importance of the advection processes in the modulating effect of the CCE. Therefore, 3D ocean models are needed to incorporate the mesoscale features of the oceanic eddies for realistically reproducing the upper-ocean responses to tropical cyclones (TCs).

Cartilage degeneration is reported to be one of the pathological symptoms of osteoarthritis (OA). Pyroptosis is highly involved in the development of cartilage degeneration and is regulated by the NLRP3 inflammasome. The present study aims to check the impact of Wufuyin granules (WFYG) against cartilage degeneration and explore the potential mechanism. Knee osteoarthritis (KOA) model was constructed in rats. The IL-1β and IL-18 level in chondrocytes and peripheral blood of KOA rats was detected by ELISA. Western Blot, qRT-PCR and immunofluorescence assay were applied to determine the IL-1β, IL-18, NLRP3, ASC and Caspase-1 levels in chondrocytes. The ROS level was visualized via immunofluorescence assay. The pyroptosis rate of chondrocytes was evaluated by flow cytometry and AO/EB staining. The release of IL-1β and IL-18 was repressed by WFYG both in-vitro and in-vivo. The pyroptosis rate of chondrocytes isolated from KOA rats was suppressed by a high dosage of WFYG. ROS in the cartilage tissue was significantly inhibited by the introduction of WFYG. IL-1β, IL-18, NLRP3, ASC and caspase-1 were downregulated by WFYG both in-vitro and in-vivo. WFYG ameliorates cartilage degeneration by inhibiting pyroptosis, possibly through suppressing the activation of NLRP3 inflammasomes.

An emerging application of nanotechnology in medicine currently being developed involves employing nanoparticles to deliver drugs, heat, light, or other substances to specific types of cells (such as cancer cells). As most biological molecules exist and function at the nanoscale, engineering and manipulating matter at the molecular level has many advantages in the field of medicine (nanomedicine). Although encouraging, it remains unclear how much of this will ultimately result in improved patient care. In surgical specialties, clinically relevant nanotechnology applications include the creation of surgical instruments, suture materials, imaging, targeted drug therapy, visualization methods, and wound healing techniques. Burn lesion and scar management is an essential nanotechnology application. Prevention, diagnosis, and treatment of numerous orthopedic conditions are crucial technological aspects for patients’ functional recovery. Orthopedic surgery is a specialty that deals with the diagnosis and treatment of musculoskeletal disorders. In recent years, the field of orthopedics has been revolutionized by the advent of nanotechnology. Using biomaterials comprised of nanoparticles and structures, it is possible to substantially enhance the efficacy of such interactions through nanoscale material modifications. This serves as the foundation for the majority of orthopedic nanotechnology applications. In orthopedic surgery, nanotechnology has been applied to improve surgical outcomes, enhance bone healing, and reduce complications associated with orthopedic procedures. This mini-review summarizes the present state of nanotechnology in orthopedic surgery, including its applications as well as possible future directions.

The cold wake caused by a tropical cyclone (TC) extends for hundreds of kilometers and persists for several weeks, thus influencing the surface response for any subsequent TCs that might pass over it. It is commonly accepted that sea-surface temperature (SST) cooling, as produced by a single TC, occurs primarily through vertical mixing. However, when there are sequential TCs, the earlier TC can dramatically change the thermal structure of the upper ocean, which may influence the subsequent development of a latter-occurring TC (LTC). Therefore, the contribution of horizontal advection and vertical mixing to SST-cooling during the passage of LTCs is of great interest. Using a 19-year-long observational dataset and the heat budget analysis of an idealized numerical simulation, the SST change during the passage of sequential TCs is investigated. The results demonstrate that, on average, the SST cooling caused by the LTC shows an overall decreasing trend with enhanced lingering wakes. Budget analysis of the model simulations suggests that an earlier TC can suppress the vertical mixing induced by an LTC mainly through an alteration of dynamics within the deepened mixed layer and that the contribution of vertical mixing to the SST cooling is weaker due to the intensification of the earlier TC. The weakened vertical mixing dominates the decreased SST cooling induced by an LTC. In contrast, the cold wake generated by an earlier TC can produce more cold water on the right side of the TC’s track, which contributes to stronger horizontal advection upon the arrival of the LTC. In general, the effects of the earlier TC can suppress the sea-surface thermal response to an LTC. If the contribution of the horizontal advection to SST cooling is neglected, the SST cooling induced by an LTC could be reduced by about 40%. As for the response of the sub-surface water to the passage of an LTC, the weakened warm anomaly induced by vertical mixing and the enhanced cooling anomaly caused by the vertical advection explain the reduced tendency for the mixed layer to deepen. As a result, the tendency for the mixed layer depth (MLD) to increase is suppressed during the passage of an LTC. These results highlight the importance of optimally depicting cold wakes in numerical simulations to improve the prediction of the upper ocean’s response to sequential TCs.

DBSCAN is a fundamental spatial clustering algorithm with numerous practical applications. However, a bottleneck of the algorithm is in the worst case, the run time complexity is $O(n^2)$. To address this limitation, we propose a new grid-based algorithm for exact DBSCAN in Euclidean space called GriT-DBSCAN, which is based on the following two techniques. First, we introduce a grid tree to organize the non-empty grids for the purpose of efficient non-empty neighboring grids queries. Second, by utilising the spatial relationships among points, we propose a technique that iteratively prunes unnecessary distance calculations when determining whether the minimum distance between two sets is less than or equal to a certain threshold. We theoretically prove that the complexity of GriT-DBSCAN is linear to the data set size. In addition, we obtain two variants of GriT-DBSCAN by incorporating heuristics, or by combining the second technique with an existing algorithm. Experiments are conducted on both synthetic and real-world data sets to evaluate the efficiency of GriT-DBSCAN and its variants. The results of our analyses show that our algorithms outperform existing algorithms.

Intervertebral disc degeneration (IDD) has caused great trouble in people's lives. Dysregulated long noncoding RNAs (lncRNAs) are closely linked to IDD progression. Our study aims to analyze the role of LINC00917 in the progression of IDD. Forty nucleus pulposus (NP) IDD tissues and 40 NP tissues of intervertebral discs without apparent degeneration were collected. TBHP was used to induce IDD. Cell proliferation was measured using the MTT and EdU assays. Pyroptosis was detected using flow cytometry. RT-qPCR and Western blot assays were performed to determine mRNA, miRNA, and protein expression. Dual-luciferase reporter and RNA pull-down assays were performed to verify the relationship between LINC00917 or NLRP1 and miR-149-5p. LINC00917 expression was enhanced in TBHP-treated nucleus pulposus cells (NPCs). The knockdown of LINC00917 promoted proliferation and inhibited cytotoxicity, inflammatory response, and pyroptosis of NPCs. LINC00917 functions as a sponge for miR-149-5p. Having silenced miR-149-5p, the effects of LINC00917 knockdown on NPC proliferation and inflammation-induced pyroptosis were alleviated. NLRP1 overexpression induced cellular dysfunction and pyroptosis of NPCs. LINC00917 knockdown restored NPC cellular functions and inhibited IDD progression by modulating the miR-149-5p/NLRP1 axis.

Although bone is a self-healing organ and is able to repair and restore most fractures, large bone fractures, about 10%, are not repairable. Bone grafting, as a gold standard, and bone tissue engineering using biomaterials, growth factors, and stem cells have been developed to restore large bone defects. Since bone regeneration is a complex and multiple-step process and the majority of the human genome, about 98%, is composed of the non-protein-coding regions, non-coding RNAs (ncRNAs) play essential roles in bone regeneration. Recent studies demonstrated that long ncRNAs (lncRNAs) and circular RNAs (circRNAs), as members of ncRNAs, are widely involved in bone regeneration by interaction with microRNAs (miRNAs) and constructing a lncRNA or circRNA/miRNA/mRNA regulatory network. The constructed network regulates the differentiation of stem cells into osteoblasts and their commitment to osteogenesis. This review will present the structure and biogenesis of lncRNAs and circRNAs, the mechanism of bone repair, and the bone tissue engineering in bone defects. Finally, we will discuss the role of lncRNAs and circRNAs in osteogenesis and bone fracture healing through constructing various lncRNA or circRNA/miRNA/mRNA networks and the involved pathways.

β-Ecdysone is a phytosteroid derived from multifarious medicinal plants, such as Achyranthes root (Achyranthes bidentata) and Tinospora cordifolia, possessing the potential anti-osteoporosis effect. However, the underlying mechanisms for β-ecdysone treating osteoporosis remain unclear. This study aims to explore the molecular mechanisms of β-ecdysone against osteoporosis by network pharmacology and molecular docking. First, the potential targets of β-ecdysone and osteoporosis were predicted by public databases. Protein interaction and functional enrichment analyses of potential targets were performed using the STRING and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway databases. Finally, hub targets were identified from network pharmacology, and their interaction with β-ecdysone was validated by molecular docking. Results showed that 47 potential targets were related to the mechanisms of β-ecdysone treating osteoporosis. Enrichment analyses revealed that the potential targets were mainly associated with steroid biosynthetic and metabolic processes, as well as HIF-1 and estrogen signaling pathways. By protein–protein interaction network analysis, top 10 hub targets were screened, including TNF, ALB, SRC, STAT3, MAPK3, ESR1, PPARG, CASP3, TLR4, and NR3C1. Molecular docking showed that β-ecdysone had good affinity with TLR4, TNF, and ESR1. Therefore, β-ecdysone might exert therapeutic effect on osteoporosis development via targeting TLR4, TNF, and ESR1 and regulating HIF-1 and estrogen pathways.

Steel–concrete hybrid towers have been proposed for onshore tall wind turbine tower installations. Their bottom sections are built with concrete and top sections with steel. The primary advantages of such hybrid towers include construction using low-cost durable material and avoidance of transport barriers associated with all-steel towers. In this study, a set of design constraints governing the geometry of hybrid towers was proposed to determine the optimal combination of concrete and steel sections. The primary constraint in tower design involves avoiding resonance because a resonant response can significantly damage the tower and trigger turbine fault conditions. A sensitivity analysis was conducted to explore the correlation between the natural frequency and geometry of a tower. The results demonstrated that an increase in the proportion of concrete can lead to a pronounced effect on the first modal frequency of taller towers. Additionally, geometric optimisation was performed on a 160 m tall tower. This resulted in a 12.7% reduction in the total cost compared with that of the initial design.

The South China coast has a high incidence of warm-sector heavy rainfall (WSHR) events. The ageostrophic winds in the boundary layer in most of these events associated with the southwesterly boundary layer jets (BLJs) mainly exhibit strong convergence at rainfall area. In this paper, we analyze two cases of WSHR in May 2013 and May 2015, which occurred in similar synoptic environments but varied in intensity, extent, and duration of rainfall, where the ageostrophic winds are the confrontational confluence and asymptotic confluence pattern, respectively. ERA-5 reanalysis data and the diagnostic equation of ageostrophic wind are used to examine the factors affecting the ageostrophic winds in the northern land region and the southern offshore region of the rainfall. The results suggest that land-sea contrast leads to the convergence of ageostrophic winds in the rainfall area. Boundary layer friction dominates the northeasterly ageostrophic winds on land. The diurnal variation of BLJs dominates the ageostrophic winds and their diurnal variation at sea, contributing southwesterly or southeasterly ageostrophic winds, so the phase difference between the land and sea forms confrontational or asymptotic confluence, respectively. BLJs with different intensities, extents, and diurnal variations can lead to different ageostrophic wind patterns and their confluence modes. The land-sea thermal contrast can directly affect ageostrophic winds, and it can also affect the diurnal variation of BLJs, thus affecting the ageostrophic winds and their confluence mode. It is further verified that the BLJs and thermal forcing are important in warm-sector heavy rainfall processes in South China.

As a typhoon approaches the continent, the position where anthropogenic aerosols penetrate, the convection competition between the eyewall and peripheral rainbands, and the separate contributions of direct aerosol-radiation interactions (ARI) and indirect aerosol-cloud interactions (ACI), yield uncertainties in the convection intensification area and hence the typhoon intensity. Typhoon Lupit (2009) was simulated using the Weather Research and Forecasting Model with Chemistry (WRF-Chem) to investigate and isolate the direct and indirect effects of aerosols on the intensity, convection, and precipitation of the typhoon. Three simulations (CTL, CLEAN, and CTLARIOFF) were designed, representing a polluted case (CTL, considering the ingestion of anthropogenic aerosols with ARI and ACI), a clean maritime case (CLEAN, mainly with sea salt aerosols), and a polluted case without aerosol radiative forcing (CTLARIOFF, as per CTL but without ARI) The results showed that anthropogenic aerosols could penetrate into both the peripheral rainbands and the eyewall when the typhoon was approaching the Asian continent Owing to the representation of the real aerosol scenario, the simulated typhoon intensity weakened and was closer to observed values in the CTL experiment. The ARI dominated over ACI with the opposite effects. Specifically, the ACI mainly enhanced the formation of ice-phase hydrometeors within the upper level of the eyewall with more freezing latent heat releases, leading to an invigoration of eyewall convection. These excess ice-phase particles melted after they descended into the warm layer below the 0°C level, which accelerated the accretion of cloud droplets by raindrops (Pcacr) and hence the mixed phase precipitation process in the eyewall. The dynamic feedback induced by the ACI enhanced the boundary layer inflow and the upper layer outflow, supporting the maintenance of strong eyewall convection and intensification of the typhoon. Inversely, the ARI heated the distant periphery low-level atmosphere at an altitude of 1–2 km by the absorbing polluted aerosols. The heated air, driven by the radial inflow, firstly went through the periphery rainbands of the typhoon and invigorated convection there due to the low-level warming. Then, the enhanced periphery convection inhibited the further transport of warm moist air into the eyewall, resulting in weakening of the eyewall convection and hence typhoon intensity. In sum, for the polluted scenario, as the typhoon approached the continent, ARI played a dominant role over ACI. The WRF-Chem model with full consideration of aerosol-cloud-radiation interactions is advantageous in terms of reliably simulating typhoon intensity and precipitation distribution.

The storm track and oceanic front play an important role in the midlatitude air–sea interaction. In this study, future changes in the impact of the North Pacific midlatitude oceanic frontal intensity on the wintertime storm track are projected based on climate model outputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5). The performance of 13 CMIP5 models is evaluated, and it is found that a majority of these models are capable of reproducing the northward intensification of the storm track in response to the strengthened oceanic front. The ensemble means of outputs from six best models under three Representative Concentration Pathway (RCP) scenarios (RCP2.6, RCP4.5, and RCP8.5) are compared with the results of the historical simulation, and future changes are projected. It is found that the impact of the oceanic frontal intensity on the storm track tends to get stronger and extends further westward in a warming climate, and the largest increase appears in the RCP8.5 run. Further analysis reveals that the stronger impact of the oceanic front on the storm track in the future may be partially attributed to the greater oceanic frontal impact on the near-surface baroclinicity, which is mainly related to the intensified oceanic frontal impact on the meridional potential temperature gradient under the climate change scenario. However, this process can hardly explain the increasing impact of the oceanic front on the upstream of the storm track.

Capture of a strong elevated ducting event, especially its maintenance and sudden change, is of great value to airborne radar to achieve its beyond-the-line-of-sight detection. However, the knowledge is not easily accessible over the open ocean and hence very rare. During the Air–Sea Interaction Survey (ASIS) over the western North Pacific (WNP) in May 2016, a strong elevated ducting event with a long-life period and sudden change in its evolution was observed. Measurements from the ASIS, images from the Himawari-8 satellite, reanalysis data from the ECMWF, and Weather Research and Forecasting (WRF) model, were used to analyze the maintenance and sudden change of this strong ducting event, together with the model performance on simulating it. The results showed that the maintenance of strong elevated ducts, with their tops ranging from 750 to 1050 m and average strength of approximately 38 M units, was caused by a strong dry air mass capping over the wet marine atmospheric boundary layer (MABL), together with the subsidence inversion associated with high pressure. The WRF model performs well in simulating them. However, a sudden increase in duct height with a slight decrease of strength was recorded by the subsequent GPS radiosonde, which was finally contributed to the mechanical turbulent inversion and hydrolapse associated with the marine low-level jet (MLLJ). The height of the maximum horizontal wind speed (Umh) of the MLLJ corresponds well with the bottom of the trapping layer. However, these jet-relevant ducts are generally weak and it is difficult to accurately simulate them by using the mesoscale numerical model, since the wind-shear produced eddies are too small to be properly parameterized.

The duration of the eyewall replacement cycle (ERC) in typhoons is determined by the rate of dissipation of the inner eyewall and intensification of the outer eyewall, which is an important indicator for predicting changes in the intensity and structure of typhoons. Previous studies on ERCs have focused on the internal storm dynamics associated with the interactions between the concentric eyewalls (CEs), but the impacts of the sea surface cooling (SSC) on ERCs remain not adequately investigated. The slow movement of Typhoon Trami results in remarkable SSC. Using a coupled atmosphere-ocean model, the simulation for Trami generates an ERC that matches observations, whereas an unrealistic long-lived ERC is produced in the uncoupled simulation. Numerical simulations suggest that the typhoon-induced nonuniform SSC can not only weaken the typhoon, but can also modulate the duration of the ERCs. The SSC acts like a catalyst for triggering the negative feedback between the surface heat exchange and the circulations of Trami to reduce the energy supply to the inner eyewall more severely where the sea surface temperature (SST) dropped more sharply. The SSC works in concert with the interactions between the CEs to weaken the inner eyewall faster, thus terminating the ERC of Trami rapidly. The results indicate that a better understanding of the modulation effect of SSC is required for the accurate forecast of ERCs.

In Part II of this study, the influence of an oceanic cold-core eddy on the atmospheric boundary layer structures of Typhoon Francisco (2013) is investigated, as well as a comparison with the cold wake effect. Results show that the eddy induces shallower mixed-layer depth and forms stable boundary layer above and near it. The changes of these features shift from northwest to southeast across the storm eye, following the translation of Francisco over the eddy. Nonetheless, the decrease in mixed-layer depth and formation of stable boundary layer caused by the cold wake are located at right rear of the storm. The sensible heat fluxes at the lowest atmospheric model level are mostly downward over the sea surface cooling region. Due to their different relative locations with Francisco, the diabatic heating in the northwest quadrant of the storm can be more effectively inhibited by the cold-core eddy than by the cold wake. The asymmetric characteristics of surface tangential wind are less sensitive to sea surface cooling than those of surface radial wind, implying a change in surface inflow angle. Different from previous studies, the surface inflow angle is found to be reduced especially above the cold-core eddy and cold wake region. An analysis of radial wind tendency budget indicates that the decrease in radial pressure gradient is dominant in changing the acceleration rate of surface radial wind, rather than the decrease in the Coriolis and centrifugal forces, and therefore more outward surface flow is induced by both the cold-core eddy and cold wake.

Due to the coarse temporal resolution of the best track databases for typhoons, some small-scale characteristics of typhoon motion have been neglected. In order to reveal the fine features of typhoon motion, the dense cloud within the radius of maximum wind (RMW) of mature typhoons, defined as a “cloud gyro” that simultaneously spins around its own rotational axis and precesses around the vertical axis, is approximated to a rigid body. Based on the principles of gyrodynamics, the derived mathematical model of a typhoon track indicates that typhoon movement is composed of translational motion governed by the steering flow and superimposed precessional motion that manifests as the inherent characteristics of typhoon tracks, especially with the external torque. High temporal resolution numerical simulation of a real case verifies the conclusion of this study, which is that the smaller the RMW, the larger the tangential wind speed or the larger the external torque, and the more obviously precessional motion manifests.

Osteosarcoma (OS) is one of the most common primary bone malignancies in children and adolescents. The toxicity to healthy tissues from conventional therapeutic strategies, including chemotherapy and radiotherapy, and drug resistance, severely affects OS patients' quality of life and cancer-specific outcomes. Many efforts have been made to develop various nanomaterial-based drug delivery systems with specific properties to overcome these limitations. Among the developed nanocarriers, liposomes are the most successful and promising candidates for providing targeted tumour therapy and enhancing the safety and therapeutic effect of encapsulated agents. Liposomes have low immunogenicity, high biocompatibility, prolonged half-life, active group protection, cell-like membrane structure, safety and effectiveness. This review will discuss various nanomaterial-based carriers in cancer therapy and then the characteristics and design of liposomes with a particular focus on the targeting feature. We will also summarise the recent advances in the liposomal drug delivery system for OS treatment in preclinical and clinical studies.

There has been a rapid increase in bone tissue regeneration since the concept of "tissue engineering." Stem cell-based biomaterials have revolutionized the field of tissue regeneration. Biomaterials play an essential part in bone regeneration through their crucial substratum for cell differentiation, cohesion, and proliferation by manipulating cells. Numerous studies have been carried out in order to create a biomaterial with diverse biological and physical characteristics. Furthermore, they developed a cell microenvironment with the desired pore magnitude to stimulate stem cells to transform them from artificial to biological microenvironments.The current review aims to give a comprehensive overview of stem cells and biomaterials in bone tissue regeneration.Initially, bone biology and its interaction with stem cells and biomaterials are briefly explained. Following that, the behavior and mechanism of biomaterials influencing the stem cells during bone tissue regeneration are emphasized. Lastly, the future outlook for tackling the current challenges for designing biomaterials/stem cell materials for bone tissue engineering (TE) is discussed.Compatible biomaterial for bone regeneration requires evaluating the structure, matrix, composition, flexibility, and nature of native bone tissue defects. The concept of TE offers a platform for designing biologically, physically, and chemically biocompatible biomaterials for stem cells to proliferate and differentiate. Currently, stem cells are increasingly used for TE with a promising outcome due to their self-renewal and differentiation potential. Furthermore, they can secrete biological-active compounds and modulate the fate and behavior of other cells in native tissues. Bone TE may flourish more rapidly and efficiently using stem cells.

Procyanidin (PC) is a polyphenolic compound with antioxidant activity. The purpose of this study was to determine the influence of PC on canine sperm quality after 72 h of storage at 4 °C. The collected ejaculates were separated into four equal aliquots and treated with various concentrations of PC (0, 10, 30, and 50 μg/mL) in Tris-citric-fructose-egg yolk (TCFE) extender and stored at 4 °C for 72 h. The findings revealed that 30 μg/mL PC was the optimum concentration for significantly improving sperm motility (p < 0.05). Sperm samples treated with 30 μg/mL PC had substantially greater plasma membrane integrity, acrosome integrity, and mitochondrial membrane potential than the control group (p < 0.05). Furthermore, T-AOC and the expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), and glutathione peroxidase 1 (GPx1) genes were significantly higher in sperm treated with 30 μg/mL PC than those in control (p < 0.05). In summary, this study discovered that adding PC to the TCFE extender enhanced sperm quality and that 30 μg/mL PC was the optimal concentration for canine sperm when stored at 4 °C.

Bone is a self-regenerative tissue that can repair small defects and fractures. In large defects, bone tissue is unable to provide nutrients and oxygen for repair, and autologous grafting is used as the gold standard. As an alternative method, the bone tissue regeneration approach uses osteoconductive biomaterials to overcome bone graft disadvantages. However, biomaterials are considered as foreign components that can stimulate host immune responses. Although traditional principles have been aimed to minimize immune reactions, the design of biomaterials has steadily shifted toward creating an immunomodulatory microenvironment to harness immune cells and responses to repair damaged tissue. Among immune cells, macrophages secrete various immunomodulatory mediators and crosstalk with bone-forming cells and play key roles in bone tissue engineering. Macrophage polarization toward M1 and M2 subtypes mediate pro-inflammatory and anti-inflammatory responses, respectively, which are crucial for bone repairing at different stages. This review provides an overview of the crosstalk between various immune cells and biomaterials, macrophage polarization, and the effect of physicochemical properties of biomaterials on the immune responses, especially macrophages, in bone tissue engineering.

Land cover in the Chinese Loess Plateau has undergone dramatic changes since the late 1980s. Revealing the trend in land cover change and eco-environmental quality response of different geomorphic units in this stage is a realistic requirement for promoting sustainable development of the Chinese Loess Plateau. Based on the data of geomorphic units and land cover in 1990, 2000, 2010 and 2018 of the Chinese Loess Plateau, we studied the trend of land cover change and eco-environmental quality response of different geomorphic units by using a significance index of land cover change, a proportion index of land cover change and an eco-environmental response model. The results indicated that from 1990 to 2018, the areas of forestland and construction land substantially increased, whereas those of cropland, grassland, wetland and unused land considerably decreased. Land cover change exhibited large geomorphic differences, and the main conversion of land cover was from cropland into other land types. Unstable trend of land cover change in the loess tablelands and sandy loess hills declined, whereas the unstable trends in the other geomorphic units enhanced. Eco-environmental quality varied among different geomorphic units. The expansion of construction land and degradation of forestland, grassland and wetland resulted in the deterioration of eco-environmental quality. The conversion of cropland and unused land into forestland and grassland, and the conversion of grassland into forestland were the main factors that drove the improvement of eco-environmental quality. The findings of this study may provide theoretical reference and support decision making for the optimization of land use structure and the improvement of eco-environmental quality on the Chinese Loess Plateau.

Simulations using a convection-permitting numerical model (The Weather Research and Forecasting, WRF) are conducted to investigate the mechanisms responsible for the maintenance and organization of long-lived moist convection into a Mei-yu rainband (091800–101,800 UTC June 2008). This rainband was composed of multiple two-dimensional precipitation bandings, being elongated from the southwest to the northeast with the narrow width. In addition to establishment of the Mei-yu frontal zone, the northwesterly flow behind the mid-tropospheric trough also brought about upper-level dry air. The downward transport of the dry air had a high value of potential vorticity and just overrode the low-level moist southwesterly component, inducing the conditional instability (CI) and frontogenesis at the coherent regions. This behavior combined with the Mei-yu frontogenesis, leading to successive convection to maintain the rainband, whereas the latent heat was not directly linked to the rainband longevity. The releases of CI, conditionally symmetric and inertial instabilities were simultaneously present in the bandings, as an indication of the mechanisms for the formation of banded structures. Therefore, the mesoscale circulations in banded convection developed in the form of coexisted upward and slantwise motions. Our attempt to integrate the dry intrusion and multiple instabilities could be a vital significance in discussing the Mei-yu rainband development.

Background Perfluorooctanoic acid (PFOA) is widely used in the manufacture of household and industrial products. It has certain toxicity and leaves many residues in the environment. Numerous studies have shown that PFOA exhibits endocrine disrupting properties and immunotoxicity and induces developmental defects. However, there is very little information regarding its toxicity on oocytes. Methods We cultured denuded oocytes in maturation medium supplemented with 0, 300, or 500 PFOA during IVM and evaluated the maturation of oocytes from the aspects of ROS(DCFH-DA), mitochondria(MitoOrange and JC-1), DNA damage(P-H2AX), and cytoskeleton(β-tubulin). Results Compared with the control group, the PFOA treatment group exhibited significantly reduced proportion of oocytes matutation. Furthermore, the DCFH-DA test showed that PFOA significantly increased reactive oxygen species (ROS) levels. PFOA disrupted mitochondrial distribution and decreased mitochondrial function as assessed using MitoOrange and JC-1. In addition, PFOA-treated oocytes exhibited a significantly higher percentage of P-H2AX, defective β-tubulin, abnormal chromosome alignment, lower expression of the anti-apoptotic gene Bcl-2, and higher expression of the apoptotic genes caspase3 and Bax. Conclusion In summary, PFOA could negatively and directly affect oocyte maturation in vitro and cause oxidative stress, mitochondrial function disruption, DNA damage, cytoskeleton damage, and apoptosis.

This paper conducted experimental and numerical investigations on seismic behaviour of masonry infilled self-centring-beam moment-frames (SCB-MFs). First, an efficient hysteretic material model was proposed for use with the equivalent strut modelling approach of infill walls. This model was defined by backbone parameters and hysteretic parameters and implemented in the OpenSees platform to facilitate its application. Then, an approximately half-scale test of infilled SCB-MFs was carried out. The test observations and load-carrying capacities of masonry walls in the specimen were reported and analysed. The experimental hysteresis was reproduced by the numerical model using the proposed infill material. Finally, structural analyses were conducted for 3-, 6-, 9-, and 12-storey infilled SCB-MFs based on the calibrated computational model. Comparisons of the hysteretic behaviours obtained by the simulation with experimental results showed that the proposed infill material could capture the strength, stiffness, and energy dissipation during reloading, along with the residual drift during unloading. The nonlinear dynamic analyses also validated the feasibility of using the proposed model to simulate the dynamic responses of infilled SCB-MFs.

Previously proposed self-centering moment-resisting frames relied on gap opening and closing in the beam–column interface to achieve recentering capability and energy dissipation capacity. ...

To evaluate short crack growth and fatigue damage accumulation in steel structures, efforts have been made based on a two-dimensional (2D) grain-based model for fatigue life assessment unde...

This paper proposes the concept of resilient friction beams (RFBs) and investigates how RFBs can be economically implemented in moment-resisting frames (MFs) to improve seismic performance . The RFBs mainly consist of two T-shaped beams and four cap plates, resulting in a cost-effective configuration that employs less steel than previous self-centring beam designs. The mechanics of the RFB are first explained, and the equations predicting its responses are given. Two numerical methods are presented for modelling RFBs. The results from a finite element model (FEM) confirmed the sliding behaviour of the RFBs. Then a simplified spring model was created for performing nonlinear dynamic analysis. Finally, a set of steel framed buildings with different heights were designed and computationally subjected to two seismic levels of ground motions. The results suggest that residual interstory drift , peak base shears and peak absolute accelerations can be effectively limited by providing RFBs at the lower storeys.