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To enhance the reliability of Ti2AlNb alloys as an aerospace engine component in marine environments， the hot salt corrosion behavior of Ti2AlNb alloy with nominal compositions of Ti-22Al-23Nb-1Mo-1Zr（atom fraction/%） coated with Na2SO4/NaCl（95/5，mass ratio）at temperatures of 550， 650 ℃ and 750 ℃ was investigated.The corrosion mass gain curves of alloys at different temperatures were drawn. The surface morphologies， cross-section structures， and corrosion products of the alloy after hot salt corrosion were examined and analyzed by X-ray diffraction（XRD）， scanning electron microscopy（SEM）， and energy dispersive X-ray spectroscopy（EDS）. The results show that the corrosion rate at 550 ℃ is lower and the oxide scales are straight， dense and intact， exhibiting excellent resistance to hot salt corrosion. The corrosion mass gain curves of the alloy follow a parabolic law at 650℃ and the oxide scales exhibit small-scale peeling and internal cracks， with a slightly layered structure. The alloy exhibits good resistance to hot salt corrosion at 650 ℃ in general. A significant mass loss is observed during the corrosion process at 750 ℃， with the oxide scales cracking and peeling severely. Furthermore， within the oxide scales emerges a distinct layered structure where two layers of corrosion products alternately exist： the main layer is mainly composed of TiO2 and contains various corrosion products including NbAlO4， while the other layer is mainly composed of NaNbO3. The resistance to hot salt corrosion of the alloy decreases seriously at 750 ℃.

The DELLA genes, also known as 'Green Revolution' genes, encode conserved master growth regulators that control plant development in response to internal and environmental cues. Functioning as nuclear-localized transcription regulators, DELLAs modulate expression of target genes via direct protein-protein interaction of their carboxy-terminal GRAS domain with hundreds of transcription factors (TFs) and epigenetic regulators. However, the molecular mechanism of DELLA-mediated transcription reprogramming remains unclear. Here by characterizing new missense alleles of an Arabidopsis DELLA, repressor of ga1-3 (RGA), and co-immunoprecipitation assays, we show that RGA binds histone H2A via the PFYRE subdomain within its GRAS domain to form a TF-RGA-H2A complex at the target chromatin. Chromatin immunoprecipitation followed by sequencing analysis further shows that this activity is essential for RGA association with its target chromatin globally. Our results indicate that, although DELLAs are recruited to target promoters by binding to TFs via the LHR1 subdomain, DELLA-H2A interaction via the PFYRE subdomain is necessary to stabilize the TF-DELLA-H2A complex at the target chromatin. This study provides insights into the two distinct key modular functions in DELLA for its genome-wide transcription regulation in plants.

With the improvement of thrust-to-weight ratio and other properties of future aero-engine，the high temperature mechanical property and structural stability of titanium alloy components are required. The limitation of traditional experiments in time and space scale has become increasingly prominent，and it is difficult to deeply study the microscopic transient phenomena and mechanisms. Moreover，the molecular dynamics（MD）calculation method takes the atomic/molecular model as the calculation object，on the basis of Newton classical mechanics and empirical parameters，the calculation efficiency is greatly improved compared with the quantum calculation method. Therefore，MD has become an important method to optimize the process parameters and calculate the microstructure properties of aero-engine titanium alloy. Based on an overview of the basic principle of MD computing space and time scale advantages，this paper reviews the relevant domestic and foreign achievements in the study of molding，microstructure characterization and performance testing of aero-engine titanium alloys by MD method in recent years，as well as representative conclusions that contribute to the improvement of high temperature resistance of aero-engine titanium alloys. Finally，the future prospect is discussed based on the demand for MD computing technology for aircraft engine titanium alloys，thus pointing out the challenges faced on the following aspects，including high-throughput composition design based on MD computing method，training molecular force fields for mature titanium alloy systems，and introducing the new ReaxFF（Reactive Force Field）into the study of combustion mechanisms.

A novel PSMA targeting molecule ［177Lu］Lu-DOTA-CPN-PSMA with high uptake and long retention in prostate cancer was developed, in which DOTA was used as the bifunctional chelator, glutamic acid-urea-lysine(Glu-Urea-Lys) was used as the targeting group, and 4-(p-tolyl)butyric acid(CP) group together with quinoline ring were introduced at the linker of this molecule. The precursor DOTA-CPN-PSMA was synthesized using solid-phase peptide synthesis method. DOTA-CPN-PSMA was labeled with carrier-free 177Lu. The influences of pH, reaction time, temperature, and ratio of 177Lu/PSMA on the radiolabeling were investigated respectively, and the optimal labeling condition was determined accordingly. The lipid water partition coefficient and in vitro stability of ［177Lu］Lu-DOTA-CPN-PSMA were also measured. Preliminary SPECT/CT imaging study of ［177Lu］Lu-DOTA-CPN-PSMA was performed in nude mice bearing 22RV1 tumor and compared with ［177Lu］Lu-PSMA-I&T. The optimization of the labeling condition shows that the addition of gentisic acid is essential, and the reaction pH is at the range of 3.5-5.5, the reaction temperature and time is 60.94 ℃ and 5.15 min respectively, the ratio of 177Lu/PSMA(mCi/μg, 1 Ci=3.7×1010 Bq) is controlled at 1∶1-2∶1. The radiochemical purity reaches over 95%, and even up to 99%. The results of in vitro stability study show that the radiochemical purity is remained ≥95% after being incubated in saline and bovine serum at 37 ℃ for 24 h. So that the solution of ［177Lu］Lu-DOTA-CPN-PSMA is used for imaging study directly without further purification. The lipid-water partition coefficient of ［177Lu］Lu-DOTA-CPN-PSMA is -2.02, indicate that it is more lipophilic than ［177Lu］Lu-PSMA-I&T. Preliminary SPECT/CT studies reveal that ［177Lu］Lu-DOTA-CPN-PSMA is mainly metabolized through kidneys. Compared with images of ［177Lu］Lu-PSMA-I&T, higher uptake in prostate tumors and lower uptake in the kidneys are displayed. After 72 h, ［177Lu］Lu-DOTA-CPN-PSMA demonstrates longer retension in tumor than ［177Lu］-PSMA-I&T, but also displays longer retention in the body. These results demonstrate the potential of ［177Lu］Lu-DOTA-CPN-PSMA as a candidate for the treatment of prostate cancer and it is worth further study.

Abstract Background Osteoarthritis (OA) is a degenerative disease related to cholesterol metabolism disorders. However, current therapies for OA are insufficient and no convincing disease-modifying OA drugs exist. Therefore, we aimed to elucidate the mechanism by which borojoa iridoid glycoside (BIG) inhibits chondrocyte apoptosis in OA. Methods Borojoa pulp was heated to 70 °C, and the main active substance in borojoa, BIG, was extracted by fractionation at an ultraviolet 254-nm absorption peak. Chondrocytes were identified by immunohistochemistry and visualized by immunofluorescence confocal microscopy. The proliferation of chondrocytes cultured with BIG was determined by MTS assay. The apoptosis of chondrocytes cultured with BIG was tested by Annexin V-FITC/PI, and the cytokine, protein, and cholesterol levels in chondrocytes were detected by ELISA, RT‒qPCR, Western blot, and biochemistry analyses. Protein‒protein interactions were verified by a coimmunoprecipitation (Co-IP) assay. Results BIG promoted chondrocyte proliferation and reduced apoptosis in vitro. BIG induced an alteration of the total RNA profiles in chondrocytes, and bioinformatic analysis showed that BIG inhibited chondrocyte apoptosis by promoting c-MYC expression; KEGG analysis confirmed that BIG-inhibited apoptosis was enriched in the cell cycle pathway. Flow cell cycle experiments confirmed that BIG promoted chondrocyte proliferation by significantly increasing the S phase cell number. The c-MYC inhibitor 10058-F4 stimulated the increased expression of IL-1β, IL-6, TNF-α, and AGEs and suppressed the cholesterol metabolism, which promoted chondrocyte apoptosis and autophagy. Co-IP analysis showed that BIG promoted the interaction of c-MYC and CH25H, Bcl-2, which suggests that BIG could inhibit chondrocyte apoptosis in part by enhancing c-MYC-mediated cholesterol metabolism. Conclusions This study confirmed that BIG promotes chondrocyte proliferation and inhibits apoptosis and autophagy, and BIG improving OA is associated with cholesterol metabolism. The results identify a potential mechanism by which BIG enhances c-MYC-mediated CH25H regulation of cholesterol metabolism in vitro and suggest that BIG might be a promising new drug against OA.

Continuous SiC fiber reinforced titanium matrix（SiCf/Ti）composite exhibiting high specific strength，high specific modulus and high temperature resistance，shows important application prospects in the aerospace field. In this paper，the development of SiCf/Ti composite's application，preparation，property control and testing technology is summarized，and the bottleneck problems required to be broken through are raised. SiCf/Ti composite shows the unidirectional performance advantages，making it suitable for rotating ring parts（bling，turbine disk，etc），rod parts（turboshaft，connecting rod，fastener，etc）and plate parts（aircraft skin，etc）. The commonly used preparation methods of SiCf/Ti composite materials are foil-fiber-foil（FFF）method and matrix coating technology（MCT）. FFF is suitable for preparing plate structural parts，and MCT is suitable for winding structural parts，such as rings，disks and shafts. The properties of SiCf/Ti composite mainly depend on SiC fiber，titanium alloy matrix and fiber/matrix interface. The microstructure and properties of SiC fibers are highly sensitive to the preparation process，and it is one of the research focuses to obtain stable SiC fibers by regulating the reactor structure and deposition conditions. The titanium alloy matrix can be coated on the fiber surface by physical vapor deposition to prepare the titanium alloy precursor wire，which is the key to the subsequent preparation of high-quality components. The interfacial microstructure，thermal stability and mechanical properties of SiCf/Ti composites are closely related to the coating on the fiber surface，so the control of coating type and structure is an important means to control the interfacial properties of SiCf/Ti composites. The application of SiCf/Ti composite materials has promoted the development of non-destructive testing technology，so researchers have carried out the basic research of ultrasonic testing，X-ray testing and acoustic emission in application of composite material testing. In order to realize the wide application of SiCf/Ti composites，further research work should be carried out in the structural design，low-cost manufacturing，failure analysis and life prediction of composite materials in the future.

Hypothermia is commonly used to protect donor hearts during transplantation. However, patients transplanted with aged donor hearts still have severe myocardial injury and decreased survival rates, but the underlying mechanism remains unknown. Because aged hearts are not considered suitable for donation, the number of patients awaiting heart transplants is increasing. In this study, we examined whether hypothermic cardioprotection was attenuated in aged donor hearts during transplantation and evaluated potential therapeutic targets. Using a rat heart transplantation model, we found that hypothermic cardioprotection was impaired in aged donor hearts but preserved in young donor hearts. RNA-Seq showed that cold-inducible RNA-binding protein (Cirbp) expression was decreased in aged donor hearts, and these hearts showed severe ferroptosis after transplantation. The young donor hearts from Cirbp-KO rats exhibited attenuated hypothermic cardioprotection, but Cirbp overexpression in aged donor hearts ameliorated hypothermic cardioprotection. Cardiac proteomes revealed that dihydroorotate dehydrogenase (DHODH) expression was significantly decreased in Cirbp-KO donor hearts during transplantation. Consequently, DHODH-mediated ubiquinone reduction was compromised, thereby exacerbating cardiac lipid peroxidation and triggering ferroptosis after transplantation. A cardioplegic solution supplemented with CIRBP agonists improved hypothermic cardioprotection in aged donor hearts, indicating that this method has the potential to broaden the indications for using aged donor hearts in transplantation., Introduction Currently, advanced heart failure places a constant and heavy burden on clinical and public health systems (1). Treatment options for heart failure include medication, ventricular assistive devices, and heart [...]

The incidence of emergence delirium (ED) is higher in preschool children undergoing tonsillectomy and/or adenoidectomy. The purpose of this study was to determine the median effective dose (ED50) of dexmedetomidine (DEX) for the inhibition of ED in preschool children by using probit regression analysis. A total of 140 anesthesia records were retrieved and divided into seven groups based on the infusion rate of DEX: .2, .25, .3, .35, .4, .45, and .5 μg·kg −1 ·h −1 . The Pediatric Anesthesia Emergence Delirium Scale (PAEDS) was used to assess ED in preschool children, and ED was defined as a PAEDS score ≥ 10. Probit regression analysis revealed that the ED50 and ED95 of DEX were .31 μg·kg −1 ·h −1 (95% CI: .29–.35) and .48 μg·kg −1 ·h −1 (95% CI: .44–.56), respectively. Probit(p) = −2.84 + 9.28 × ln (Dose), (χ 2 = 1.925, P = .859). The PAEDS score was significantly increased in the ED group, and the rate of bradycardia was significantly decreased in the ED group compared with the without ED group (27.3% vs 54.1%, P = .02). DEX can effectively inhibit the ED in preschool children undergoing tonsillectomy and/or adenoidectomy, however, bradycardia was the main complication.

ObjectiveTo determine the prevalence of avian influenza viruses in the external environment of poultry in Anqing City， Anhui Province， and provide scientific evidence for prevention and control of animal-derived influenza in humans.MethodsA total of 28 farmers’ markets/farms in 10 counties （cities， districts） of Anqing City， Anhui Province， were selected as surveillance sites by simple random sampling strategy. Poultry faeces and other related samples were collected for 6 consecutive weeks. Real-time fluorescence quantitative PCR was used to examine the nucleic acids of influenza A virus. Subtypes H5， H7， and H9 of avian influenza virus were further tested in the positive samples.ResultsA total of 426 specimens were collected， among which 113 tested positive with a positive rate of 26.53%. Among the positive specimens， 104 were determined to be subtype H9， accounting for 92.04%. It did not significantly differ in the positive rate between the main and non-main urban areas （χ20.05） or among the specimens collected in different weeks （χ2=7.57， P>0.05）. However， it significantly differed in the positive rate among the specimens collected in the third week and other weeks （χ2=6.89， P

With the new concept of computing force network being put forward, how to manage, cooperate and deploy after the integration of computing power and network has become an urgent problem for telecom operators. To better solve the problems of unified management, perceptual dispatch, and collaborative arrangement of multi-dimensional resources such as network, computing, and storage, we study from the direction of computing force network management and control. Then we investigate the overall architecture design of computing force network management and control system, the core capabilities, and the evolution of underlying network technology. Based on the principle of "the network changes with the computing force, and the network strengthens the computing force", the collaborative mode of "horizontal connection and vertical dispatch" of the computing force network is formed with the help of the management and control system capabilities. Eventually, we believe it will effectively support the development demands of computing force network business and help the development of the national "Eastern Data and Western Computing" project.

Tumor metastasis is a leading cause of breast cancer-related death. Taxane-loaded polymeric formulations, such as Genexol PM and Nanoxel M using poly(ethylene glycol)-poly(d,l-lactide) (PEG-PLA) micelles as drug carriers, have been approved for the treatment of metastatic breast cancer. Unfortunately, the physical instability of PEG-PLA micelles, leading to poor drug loading, premature drug leakage, and consequently limited drug delivery to tumors, largely hinders their therapeutic outcome. Inspired by the enantiomeric nature of PLA, this work developed stereocomplex PEG-PLA micelles through stereoselective interactions of enantiomeric PLA, which are further incorporated with a hypoxia-responsive moiety used as a hypoxia-cleavable linker of PEG and PLA, to maximize therapeutic outcomes. The results showed that the obtained micelles had high structural stability, showing improved drug loading for effective drug delivery to tumors as well as other tissues. Especially, they were capable of sensitively responding to the hypoxic tumor environment for drug release, reversing hypoxia-induced drug resistance and hypoxia-promoted cell migration for enhanced bioavailability under hypoxia. In vivo results further showed that the micelles, especially at a high dose, inhibited the growth of the primary tumor and improved tumor pathological conditions, consequently remarkably inhibiting its metastasis to the lungs and liver, while not causing any systemic toxicity. Hypoxia-responsive stereocomplex micelles thus emerge as a reliable drug delivery system to treat breast cancer metastasis.

In this paper, a new pyrroloquinoline-derivative-based fluorescent probe, PQP-1, was prepared for the selective detection of Lys in living cells and natural mineral water for drinking. PQP-1 exhibited high selectivity, low limit of detection, and a wide pH range. PQP-1 could be successfully applied for imaging Lys in living cells and in natural mineral water for drinking. We expect that PQP-1 will expand the detection reaction mechanism and the practical biological applications of Lys.

Abstract Background Self-directed learning (SDL) is one of the most important abilities for medical students in terms of their future clinical medical practice. During the blended teaching process, teachers can design a variety of learning activities to cultivate students’ SDL abilities. This study aimed to assess the differences between the SDL abilities of medical students using blended and traditional didactic teaching. Methods This study included 239 medical students from eight administrative classes. The students were divided into two groups: (1) the experimental group (EG), which included 119 students from four administrative classes, and (2) the control group (CG), which included 120 students from the remaining four classes. From February to July 2022, blended teaching methods were applied to the EG group, and SDL abilities were assessed in comparison to the CG group receiving traditional didactic teaching methods. Results At the end of the semester, significant differences (p

Continuous SiC fiber reinforced titanium matrix composite（SiCf/Ti composite）has good specific strength and comprehensive mechanical properties, it is a lightweight high temperature structural material that attracts much attention in the new generation of equipment development. SiCf/Ti composites can be prepared by the methods of foil fiber foil（FFF）and matrix coating fiber（MCF）. In order to compare the effects of the two methods on the growth of interfacial reaction, SiCf/TC17 composites were prepared by FFF and MCF respectively. By study the interfacial reaction layer thickness of composites prepared by the two processes after thermal exposure at the temperature from 800℃ to 900 ℃, the microstructure and the thickness of interfacial layer were analyzed by scanning electron microscope, further the interfacial reaction rate at high temperature was obtained, and the interfacial reaction kinetic parameters of different materials were attained. The results showed that the interfacial reaction rate of SiCf/TC17 composite prepared by MCF method was higher than that of the composites prepared by FFF method at the same temperature. The interfacial reaction rate factor k0 is 4.942×10−3 m/s1/2 and 8.149×10−3 m/s1/2 for the composites prepared by MCF and FFF method, respectively. Additionally, the reaction activation energy Q is 276.3 kJ/mol and 291.7 kJ/mol for those, respectively. This is because the titanium alloy matrix prepared by MCF method has smaller phase structure and higher element diffusion rate at high temperature. Therefore, the composite prepared by MCF has lower reaction activation energy at high temperature.