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The outlet guide vane (OGV) is integrated with the lobed mixer to improve the exhaust system’s performance with a high core inlet swirl. The best location for integrating the OGV is along the central line of the lobe’s trough and near the exit plane of the lobed mixer. Two types of lobed mixers (the scalloped reference lobed mixer and the scalloped de-swirling lobed mixer) integrating with/without OGVs, are numerically researched under eight inlet swirl conditions ranging from 0° to 35°. The simulation used the Reynolds-Averaged Navier-Stokes (RANS) method with Shear Stress Transport (SST) model based on an unstructured mesh of 30 million cells. The reserved outlet flow angle of the de-swirling lobed mixer is beneficial for enhancing the strength of downstream streamwise vortices and accelerating the jet mixing. After integrating with OGV: it can significantly suppress the leakage vortex between the lobe trough and the central body and the backflow downstream of the central body; on the other hand, it can further increase the strength and scale of streamwise vortices by expanding the radial range of inner secondary flow, thereby accelerating mixing and reducing total pressure loss & thrust loss. Under the design condition, the integrated de-swirling lobed mixer can increase thrust by 3.18% and reduce the mixing loss by 31.17% compared with the reference lobed mixer. Even under non-design conditions, the integrated de-swirling lobed mixer can still use upstream inlet swirl to enhance the streamwise vortices and accelerate the jet mixing within the conditions studied in this paper. The outlet jet uniformity of the integrated de-swirling lobed mixer is better than that of the integrated reference lobed mixer for the case with the same core inlet swirl. Compared with the latter, the former also has better tolerance to the attack angle, especially for the negative attack angle conditions. Under the condition with a core inlet swirl of 35°, the thrust loss of the integrated de-swirling lobed mixer is 2.15% lower than that of the integrated reference lobed mixer.

Background Hemorrhagic transformation (HT), especially symptomatic HT (sHT), seriously affects the functional prognosis in patients following mechanical thrombectomy (MT). The present study aimed to investigate the association of HT with heart rate variability (HRV) using multiple parameters in patients undergoing MT. Methods Between November 2019 and April 2024, we enrolled eligible patients according to the inclusion criteria and exclusion criteria. Linear parameters and nonlinear approaches reflecting HRV were calculated and analyzed. Results A total of 254 patients were included in the analysis, including 56 patients with HT and 198 patients without, and 24 patients with sHT and 230 patients without. Nonlinear approaches including SD1/SD2 ratio, Higuchi fractal dimension (HFD), large-scale multiscale entropy index (MSE LS ), multiscale entropy area under the curve (MSE AUC ), large-scale composite multiscale entropy index (CMSE LS ), and composite multiscale entropy area under the curve (CMSE AUC ) were showed to be independently associated with sHT (p < 0.05). Meanwhile, receiver operating characteristic curves suggested that CMSE LS was a better indicator to predict sHT than other HRV parameters, with the area under the curve of 0.708 (95%CI 0.581–0.835). Conclusions Nonlinear parameters of HRV including SD1/SD2 ratio, HFD, MSE LS , MSE AUC , CMSE LS , and CMSE AUC provide an independent indicator for predicting sHT in patients following MT.

Unsteady numerical simulations, coupled with the SST (Shear Stress Transport) k-ω turbulence model, were conducted to study the mixing-enhancement characteristics of the excited jet generated by the fluidic oscillator and the air tab in a single channel convergent nozzle with an inlet total pressure of 140–200 kPa. Compared with the steady air-tab jet, the sweeping jet generated by the fluidic oscillator has roughly the same penetration in the main flow, but it can induce streamwise vortices and planar vortices of larger scale and longer duration, which is beneficial to enhance jet mixing efficiency in the range of 1.0 DN (DN represents the diameter of the main nozzle outlet) downstream from the main nozzle. When x > 1.0 DN, the jet mixing is mainly dominated by the shear layer between the main jet and the ambient. As the sweeping jet suppresses the expansion of the main jet, which reduces the contact area between the main jet and the ambient, its mixing efficiency is less than that of the air tab in this region. With the increasing inlet total pressure of the fluidic oscillator, the influence range of the sweeping jet is increased, but its mixing efficiency does not increase significantly. In general, the fluidic oscillator can use a small jet flow (<5%) to achieve a high mixing efficiency (i.e., 60% at x = 2.0 DN) at the expense of low total pressure loss (<2.3%), which indicates that it has good engineering applicability.

The biomimetic turbine has an excellent flow drag reduction ability and wide incidence adaptability, so it has the potential to achieve high efficiency within a wide working range of high-performance variable cycle engines. A biomimetic cascade that can broaden the effective working incidence angles was designed based on a high-loading low-pressure turbine cascade, and its flow mechanism and aerodynamic performance were studied using experimental and numerical methods under the incidences angle (i) of 0° to 15° and Reynolds number of 1.0 × 105. A series of counter rotating vortex pairs induced by the biomimetic cascade bring additional dissipation losses, but it accelerates the energy exchange between the boundary layer and mainstream, enhancing the dissipation of the pressure side leg of horseshoe vortex, and thus suppressing the flow separation and passage vortices. The undulating surface of biomimetic cascades can suppress the expansion of secondary flow in a spanwise direction in the end region, especially for large-scale separation under high incidence conditions. When i < 5°, the loss of biomimetic cascades is slightly higher than that of the original cascades, but the increase is only 0.5%; when i > 5°, the losses of biomimetic cascades are significantly reduced, with a maximum reduction of 70% at i = 15°.

This paper focuses on the dynamic internal flow in the integrated aggressive intermediate turbine duct (AITD) with different HPT wake numbers, using CFX Solver with dynamic Reynolds-averaged Navier–Stokes equations (RANS), the shear stress transmission κ-ω turbulence model (SST) and the γ-θ transition model. The HPT wakes are simulated using sweeping rods, with the number of rods ranging from 14 to 56 and a reduced frequency of 1.07. The increasing wake number reduces the radial pressure gradient in the integrated AITD, and then decelerates the radial migration and dissipation of wake vortices, so that some residual wakes can reach the integrated low-pressure turbine guide vane (LPT-GV) to enhance the suppression of flow separation to a certain extent. On the other hand, the increase in wake number can also weaken the skewness and stretching of the wake, thereby increasing the duration of flow separation suppression. When there are too many wakes, the mixing between adjacent wakes accelerates the dispersion of wake vortices, leading to increased total pressure loss and an enhanced turbulence intensity. This enhanced turbulence intensity promotes bypass transition on the suction surface of the LPT-GV in advance, thereby completely eliminating flow separation on the LPT-GV in the entire spatiotemporal domain, which is beneficial for reducing separation loss, but also increasing turbulent viscous loss. When N ≤ 28, the gross loss of the integrated AITD studied in this paper reaches a minimum value (around 0.22), as the benefits brought by the wake suppression of flow separation can offset the wake dissipation loss and the turbulent viscous loss caused by the wake-induced transition. Considering that wake loss is inherently present, using sweeping wakes to inhibit the flow separation on the integrated LPT-GV can bring certain aerodynamic benefits when the wake number is less than 28.

A dynamic simulation was launched to research the influence of high-pressure turbine (HPT) rotor wake passing frequency on the flow mechanism in an integrated aggressive interturbine duct (AITD). Sweeping rods were adopted to replace the HPT rotors to decouple the influence of its wake from those of other secondary flows. The diameter of the rods (d/s, nondimensionalized by the pitch (s) of the integrated struts at midspan) was 0.10, and their reduced frequency (f) ranged from 0.49 to 1.61. The k–ω SST turbulence model and γ–θ transition model were adopted for the turbulence closure. A 6.3-million-node structured grid was used to meet the grid dependency. Along with increasing f, the intensified circumferential motion of the wake (1) enhances the wake vortex stretching and exhaustion near the hub; (2) promotes the radial inclination of wakes and elongates and narrows the wake vortex band, resulting in increased spacing between the adjacent wake vortices and the weakened vortex interaction. In the high-f cases, the enhanced turbulence intensity in the interval between the adjacent wakes could suppress the separation bubble on LPT-GV in advance, but the elongated and narrowed wake vortices resulted in a substantial reduction in the radial extent and duration of their suppression on the separation bubble. Therefore, the influence of f on the integrated AITD and its parts was bidirectional, and adjusting the sweeping frequency to balance its positive and negative effects could minimize the total loss in the integrated AITD.

Cultivated land protection （CLP） entered the new era of macro administration in 1999 in China. This paper presents a holistic analysis of cultivated land use change concerning the three goals of the CLP, i.e., grain security, ecological security and harmonizing regional development. Farmers＇ willingness to grow grain has been the key factor in safeguarding grain security. Grain-for-green policy has contributed to improving ecological state especially in the western provinces. Effects of the land macro-control of the CLP on harmonizing regional development were significant. Moi＇eover, cultivated land use change in 1999-2007 points out the way of the evolving poliey in the future. From the viewpoint of normative concept of multifunctionality, we discuss development of the three land functions, i.e., production function, environmental function and carrier function. Finally, we propose to emphasize multifunctional land management based on regional differences to promote transition of the CLP.

Land function change has been the focus of scientific research and policy making worldwide. Agricultural development and land use demand at present in China shared common characteristics with the countries such as Japan, South Korea, USA, and European developed countries, which have undergone cultivated land function transition. Whether cultivated land function transition occurred is of significance for land change science and cultivated land protection in China. However, there has been no explicit methodology for cultivated land function change research. This paper firstly presents a methodology by integrating policy development analysis based on the normative connotation of cultivated land function or termed cultivated land function demand and quantitative assessment based on the positive connotation of cultivated land function or termed cultivated land function supply. Then, cultivated land function transition is diagnosed by analyzing cultivated land function change in 1949-2012. Results show that cultivated land function transition overall occurred in 2006. Specifically, the normative cultivated land function or cultivated land function demand fragmented into seven types in 1985 and upgraded in 2004. Total value of the positive cultivated land function or cultivated land function supply turned to rise with an increase from 2.40 to 2.45 as the coefficients of variability （CV） of the value of the seven functions decreased from 2.94 to 2.29 in 2006-2012. The two-year gap between these two aspects of transition mainly resulted from the time lag effects of policy implementation. In the process of the transition, co-ordination and malposition of supply and demand of cultivated land function coexisted with supply lag and function morphology distortion. Considering the transition experiences in the developed countries mentioned above, suggestions on multifunctional cultivated land man- agement are proposed. Moreover, route of land use transition research is discussed.

Exosomes participate in many physiological and pathological processes by regulating cell–cell communication, which are involved in numerous diseases, including osteoarthritis (OA). Exosomes are detectable in the human articular cavity and were observed to change with OA progression. Several joint cells, including chondrocytes, synovial fibroblasts, osteoblasts, and tenocytes, can produce and secrete exosomes that influence the biological effects of targeted cells. In addition, exosomes from stem cells can protect the OA joint from damage by promoting cartilage repair, inhibiting synovitis, and mediating subchondral bone remodeling. This review summarizes the roles and therapeutic potential of exosomes in OA and discusses the perspectives and challenges related to exosome-based treatment for OA patients in the future.

The domestic pig has been widely used as an important large animal model. Precise and efficient genetic modification in pig provides a great promise in biomedical research. Recently, clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system has been successfully used to produce many gene-targeted animals. However, these animals have been generated by co-injection of Cas9 mRNA and single-guide RNA (sgRNA) into one-cell stage embryos, which mostly resulted in mosaicism of the modification. One or two rounds of further breeding should be performed to obtain homozygotes with identical genotype and phenotype. To address this issue, gene-targeted somatic cells can be used as donor for somatic cell nuclear transfer (SCNT) to produce gene-targeted animals with single and identical mutations. In this study, we applied Cas9/sgRNAs to effectively direct gene editing in porcine fetal fibroblasts and then mutant cell colonies were used as donor to generate homozygous gene-targeted pigs through single round of SCNT. As a result, we successfully obtained 15 tyrosinase (TYR) biallelic mutant pigs and 20 PARK2 and PINK1 double-gene knockout (KO) pigs. They were all homozygous and no off-target mutagenesis was detected by comprehensive analysis. TYR⁻/⁻pigs showed typical albinism and the expression of parkin and PINK1 were depleted in PARK2⁻/⁻/PINK1⁻/⁻pigs. The results demonstrated that single- or double-gene targeted pigs can be effectively achieved by using the CRISPR/Cas9 system combined with SCNT without mosaic mutation and detectable off-target effects. This gene-editing system provides an efficient, rapid, and less costly manner to generate genetically modified pigs or other large animals.