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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 ℃.

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.

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.

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.

Research on sense of place in the field of geography is mostly focused on adults, with relatively little research on children's sense of place, ignoring changes in human perceptions, experiences, and attitudes toward the environment from childhood onward. In the field of psychology, child studies tend to focus on the temporal dimension of childhood growth and are relatively inadequate in the spatial dimension, lacking attention to interactions and actual experiences of children with place and space. This study focuses on the human-place relationship of children in daily life against the background of the new turn in cultural geography. Among children, animation, as the main medium through which they perceive the external world, contributes to their cognitive and emotional connections with families, communities, schools, and even cities, and plays an important role in fostering their sense of place. Therefore, based on the perspective of new cultural geography, this study takes Peppa Pig as an example and uses text analysis and other methods to analyze the mechanism through which animation builds children's sense of place by analyzing the scenes and plot elements of the animated series. This study finds that this mechanism contains the following four main dimensions: (1) Aesthetics and familiarity: This dimension includes small-scale and symbolic scene restoration of Peppa Pig; simple, caring, calm, and with the use of warm colors; and childish and awkward drawing styles that meet children's cognition, which can resonate with children and create a sense of familiarity. (2) Sense of belonging: In the social space that the protagonist is exposed to, the animation depicts an ideal family space, including the care of elders and the harmony of family relations; children thus form a sense of "home space" through Paige's "home." Through Paige's "home," children form a sense of belonging to "home." (3) Social bonding and social interaction: In this dimension, the "stress-free" "non-tame" and "low-control" school space implicitly influences children's cognitive and emotional connections to school; in addition, the richness and variety of social scenarios build bridges between children and the real social environment. (4) Nature bonding: The large proportion of nature scenes in the animation effectively compensates for the lack of nature experience of many urban children; the interaction mode between the protagonist and nature panpsychism, embodiment and parent-child interaction enriches their cognition and experience of the natural environment. Overall, through the interactive experience between the protagonist and the place, the animated series "Peppa Pig" shows preschool children the "non-controlled" locality of family space and the "non-regulated" locality of school space, constructing their sense of beauty, familiarity and a sense belonging to the place. In this sense, animation, as a "virtual buffer zone" that expands children's cognitive space, can stimulate their geographical imagination of the real world and is an important medium for developing their sense of place. The interpretation of this mechanism in this study helps to enrich the current research on children's geography and sense of place in China.

In this paper, 66 samples belonging to 12 varieties of domestic high-gluten wheat in 2021 were collected, and their physicochemical, rheological and bread sensory properties were analyzed. The results of the main component analysis showed that the total sensory score of bread had a strong correlation with gluten index, maximum tensile resistance, mixing time, stretching area and stabilization time, etc. At the same time, the screening of wheat varieties with high similarity through cluster analysis could play a key guiding role in the development and maintenance of production stability of baking special flour. Comparing the fitting quality of the bread total sensory score prediction model established by the three methods of stepwise regression, partial least squares and neural network model, the model built using artificial neural network was significantly better than other models. Using neural network models, the baking characteristics of different varieties of wheat could be quickly predicted, ensuring product stability, while also facilitating the development of more targeted baking special flours.

To improve the interface compatibility, dielectric properties and energy storage density of polyimide(PI)-based composite materials, the core@dual-shell nanoparticles, BT@TiO2@PDA were obtained via facile solution method using the dopamine to coat on the BT@TiO2 nanoparticles, which is barium titanate (BT) coated with amorphous-TiO2, hydrolyzed from tetra-n-butyl titanate (TBT). A series of modified BaTiO3/PI (BT@TiO2@PDA/PI) composites with different contents of BT@TiO2@PDA were prepared through a solution casting film formation method. The results show that the dispersion of nanofillers in the polymer matrix and the interface compatibility between them can be improved by utilizing core@dual-shell nano-structured BaTiO3. The permittivity κ of BT@TiO2@PDA/PI composite films with 40%(mass fraction) filler loading increase to 8.8 (1 kHz), which is about 2.7 times higher than that of pristine polyimide, 1.4 times higher than that of pristine BaTiO3/PI composite films. Temperature-dependent and frequency-dependent dielectric performance tests confirm that BT@TiO2@PDA/PI composites possess good temperature and frequency stability. In the frequency range of 100 kHz, the dielectric loss of the composites is less than 0.010; when the filler loadings are under 40%, the permittivity of the composites decreases by less than 0.6 (1 kHz) from 25 ℃ to 160 ℃.

Abstract Background The thalamus plays a crucial role in transmitting nociceptive information to various cortical regions involving migraine-related allodynia and photophobia. Abnormal structural and functional alterations related to the thalamus have been well established. However, it is unknown whether the brain structure and function of the thalamic subregions are differentially affected in this disorder. In this study, we aimed to clarify this issue by comparing the structure and function of 16 thalamic subregions between patients with episodic migraine (EM) and healthy controls (HCs). Methods Twenty-seven patients with EM and 30 sex-, age- and education-matched HCs underwent resting-state functional and structural magnetic resonance imaging scans. Functional connectivity (rsFC), grey matter volume (GMV), and diffusion tensor imaging (DTI) parameters of each subregion of the thalamus were calculated and compared between the two groups. Furthermore, correlation analyses between neuroimaging changes and clinical features were performed in this study. Results First, compared with HCs, patients with EM exhibited decreased rsFC between the anterior-medial-posterior subregions of the thalamus and brain regions mainly involved in the medial system of the pain processing pathway and default mode network (DMN). Second, for the whole thalamus and each of its subregions, there were no significant differences in GMV between patients with EM and HCs (P > 0.05, Bonferroni corrected). Third, there was no significant difference in DTI parameters between the two groups (P > 0.05). Finally, decreased rsFC was closely related to scores on the Hamilton Rating Scale for Anxiety (HAMA) and Big Five Inventory (BFI) scales. Conclusion Selective functional hypoconnectivity in the thalamic subregions provides neuroimaging evidence supporting the important role of thalamocortical pathway dysfunction in episodic migraine, specifically, that it may modulate emotion and different personality traits in migraine patients.

Abstract Background Laryngeal mask airway(LMA) have been widely used in clinical practice. Irritation to the patient during the insertion of a laryngeal mask can cause hemodynamic fluctuations, which is particularly unsafe for geriatric patients. We used probit regression analysis to determine the median effective dose of sufentanil to inhibit the response to LMA insertion in geriatric patients. Methods A total of 90 patients were selected for the study using the following inclusion criteria: age ≥ 65 years old, ASA grade I–III, and scheduled to undergo intravenous general anesthesia with LMA insertion. Each patient received a dose of sufentanil for anesthesia induction in one of six levels: 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3 μg kg−1. LMA insertion was scored with a 3-point, 6-category scale, with scores ≥ 16 indicating effective LMA insertion, and

In this paper, we consider the Internet Protocol(IP) network quality and study the impact of network performance factors, such as delay and packet loss on the end-to-end service quality of major accounts and overall quality of internet. We propose a unified architecture design and conduct an investigation on IP network quality monitoring and optimization solutions through a combination of Telemetry, Twamp, IFIT, Flow and other applications of new technologies. The results indicate that the deployment of proposed design can provide effective improvements in the timeliness, authenticity and reliability of monitoring data. Meanwhile, it will collect and analyze the quality data of massive packet granularity, and realize fault warning with the help of AI intelligent prediction capabilities after the deployment of design. The proposed design can both improve the quality of services, and further enhance the existing network's " autonomous driving" capabilities.

The microstructure evolution, tensile properties and fracture behavior of five-element Ti2AlNb alloy Ti-22Al-23Nb-1Mo-1Zr (atom fraction/%) ring forging at different solution temperatures of 850, 880, 900 ℃ and 750 ℃ aging treatment (AT) were studied by scanning electron microscope (SEM), transmission electron microscopy (TEM) and mechanical testing machines. The results show that with the increase of solution temperature, the fine lamellar O phase is more solid-dissolved into the B2 phase matrix, the coarse lamellar O phase gradually becomes coarser and the volume fraction of O phase decreases after solution treatment (ST). After ST+AT, a very small amount of fine lamellar O phase precipitates from the B2 phase matrix at a higher solution temperature, coarse lamellar O phase is coarsened, the volume fraction of O phase tends to be the same. The tensile strength of the alloy decreases, while the ductility increases with the increase of solution temperature. The tensile fracture morphology is a quasi cleavage characteristic of typical cleavage and dimple mixed fracture. There are microcracks, slip characteristics and the bending O phase elongated along tensile direction in the longitudinal fracture. Dislocations distribute along the B2/O phase boundary. The small size of the lamellar O phase can effectively reduce the dislocation slip distance, resulting in strong strengthening effect.

Congenital syphilis is a significant public health problem. Pregnant women infected with Treponema pallidum present with various clinical manifestations, mainly including skin or visceral manifestations. The extensive clinical manifestations of T. pallidum infection mimic those of many other diseases during pregnancy, which may lead to delayed diagnosis and serious consequences. We report a case of fetal T. pallidum infection and premature delivery in a woman whose syphilis screening was negative at 16 weeks of gestation. Despite presenting to the dermatologist at 24 weeks of gestation with maculopapular rash which is usually associated with secondary syphilis, the diagnosis of syphilis was not considered. This case shows that even if early syphilis screening of pregnant women is negative, they may still get infected with T. pallidum later on in pregnancy. Therefore, in patients presenting with a rash without an obvious cause, T. pallidum infection should be excluded. The health status of patients' spouses should be assessed during pregnancy. Additionally, perinatal health education is necessary for women and their spouses during pregnancy. The abovementioned factors could reduce the probability of T. pallidum infection in pregnant women and their infants.

As one of the important materials for new generation aeroengines, Ti2AlNb alloy has many good properties, including good processability, great comprehensive mechanical properties and low density. In order to widen the application field of Ti2AlNb alloy, the optimization of alloy composition and the control of process and microstructure need to be carried out to further enhance the oxidation resistance property of traditional Ti2AlNb alloy. In this study, the compound method of Mo, Zr, W alloys on traditional Ti-Al-Nb alloy was designed to improve the oxidation resistance property of Ti2AlNb alloy. The oxidation mass gain behaviour, the oxide layer structure, surface oxides and the alloy composition distribution of these Ti2AlNb alloys during the high temperature oxidation process at 750 ℃ and 850 ℃ were analyzed and compared. It is found that the oxidation resistance of Ti2AlNb alloy with Mo alloying element decreases obviously when temperature increases from 750 ℃ to 850 ℃, while the oxidation resistance of Ti2AlNb alloy with Zr alloying element still keeps excellent; the oxide scale microstructure of these Ti2AlNb alloys is made up of oxidation layer, oxygen enrich layer and interstital affected layer according to the SEM morphology analysis of these cross-sections samples. It is believed that Zr and W alloying elements have the coordination repression effects on the formation of different oxide layers during the oxidation process at 850 ℃. Therefore, the kind of Ti2AlNb alloy with both Zr and W alloying elements was recommended as the promising anti-oxidation Ti2AlNb alloy.

Duplex kidney is a common congenital malformation appeared as duplication of pelvis and ureter. However, renal duplication within sinus renalis is an extremely rare variation of the renal collecting system. In this study, we report a case of an asymptomatic kidney disease in a 33-year-old man, who demonstrates abnormal echo of renal sinus anomaly discovered incidentally in ultrasound examination. Computed tomography urography (CTU) exhibited the other small duplex kidney located in renal sinus. In the excretory phase images, the contrast medium within its small renal pelvis could be seen to flow into the right major renal calices. This case exhibited a very rare anatomical variation of duplicated renal malformation.

High-frequency rectifiers at terahertz regime are pivotal components in modern communication, whereas the drawbacks in semiconductor junctions-based devices inhibit their usages. Here, the authors report electromagnetic rectification with high signal-to-noise ratio driven by chiral Bloch-electrons in type-II Dirac semimetal NiTe2-based device allowing for efficient THz detection.

The property of continuous SiC fiber reinforced titanium matrix composites is strongly affected by the interface strength.The interface shear strength of SiCf/TC17 was tested by fiber push-out test and then the microstructure of the sample was observed by SEM. The process of cooling from the composite consolidation temperature, specimen preparation for the push-out test, and the actual testing were simulated by using the finite element method. The initial temperature when residual stress begun to exist was identified through regarding the friction force when the fiber was completely separated from the matrix as the starting point.And the distribution of residual stress was analyzed before and after the sample preparation.The influence of the sample thickness and the fiber fraction volume on the distribution of the residual stress was studied.Cohesive zone model was used to analyze the interface chemical bonding strength.The results indicate that the initial temperature below which the residual stress starts to be generated is about 775 ℃.The residual shear stress is introduced at the interface after sample preparation.The difference between the test results of the interface shear strength and the interface chemical bonding strength is due to the existence of the interface residual shear stress.And the interface chemical bonding strength of SiCf/TC17 composites is about 450 MPa at room temperature.

In this work, a hybrid laminated plate is developed by changing ply orientations and stacking sequences. The hybrid laminated plate is composed of carbon nanotube reinforced composite and fiber reinforced composite layers. Negative Poisson’s ratio (NPR) is obtained for the case of [22F/(22C/−22C)3T/−22F] laminate. A theoretical laminated model considering geometric nonlinearity and shear deformation is presented. Based on a two-step perturbation method, the solutions of the motion equations are obtained to capture the nonlinear frequencies and load–deflection curves. On this basis, the fourth-order Runge–Kutta method is used to obtain the dynamic response of hybrid laminated plates. The presented model is verified by comparing the results obtained analytically and numerically. Several factors such as loading and distribution of carbon nanotubes (CNTs), and foundation type are considered in parametric study. Numerical results indicate that the thermal-mechanical behavior of hybrid laminated plates significantly improved by properly adjusting the CNT distribution. In addition, the results reveal that changes in temperature and foundation stiffness have pronounced influence on the nonlinear vibration characteristics of hybrid laminate plates with NPR as compared to those with positive Poisson’s ratio.

Quinary Ti-22Al-23Nb-2(Mo, Zr) alloy has a broad application prospect in the aeroengine field. The temperature ranges of phase regions, β/B2 processing, heat treatment and the corresponding mechanical properties were investigated by SEM, TEM and multi mechanical testing machines. The results show that the alloy goes through B2, B2+α2, B2+α2+O and B2+O four phase regions in the sequence from high temperature to low temperature, the corresponding critical temperatures are 1060 ℃, 950 ℃ and 930 ℃ respectively. The composition and morphology of the grain boundary phase are influenced by the collective effect of distortion degree of B2 grains and heat treatment. Coarse discontinuous α2 phase is easy to form at the boundaries of original B2 grains with high distortion degree, and is converted into α2+Orim structure if heat treated at B2+O phase region; The fine continuous O phase is inclined to form at the boundaries of dynamic recrystallized B2 grains with low distortion degree, which can be completely transformed into α2 if heat treated at B2+α2 phase region; no phase is formed at the boundaries of static recrystallized B2 grains. Precipitates within B2 grains are mainly influenced by heat treatment. α2 and O can directly and independently precipitate from B2, O can also attach α2 to form an α2/Orim core-shell structure. The α2/Orim core-shell structure indicates α2 has good stability at low temperature. After solid solution and aging treated, mixed microstructure with bi-size precipitates emerge within B2 grains, which can be coarse α2/Orim+ fine O or coarse OI+OII with the corresponding solution treatment at B2+α2 and B2+O respectively. The size distribution of B2 precipitated phase in grain is the main factor affecting the mechanical properties . Larger size is favorable for the ductility and toughness of alloy, but unfavorable for strength and creep resistance.

Carbon nanomaterials with low density, high strength, high elastic modulus, excellent conductivity and thermal conductivity are the ideal reinforcing phases for TiAl-based alloy. In this paper, the preparation and surface treatment methods of TiAl-based alloy modified by carbon nanofibers, carbon nanotubes and graphene are reviewed. The influence of material and processing on the interface structure and mechanical properties are introduced, and strengthening mechanisms are also summarized. The preparation technology of graphene modified TiAl-based alloy will be the key development direction of future research. The key problems of graphene uniform dispersion technology, interface reaction control and action mechanism in TiAl- based alloy matrix are the difficulties in the research field of this technology.

In the present study, Ti-10V-2Fe-3Al (Ti-1023) alloy was prepared by vacuum consumable melting and forging technique. The structural stability, microstructural evolution and mechanical behavior of the alloy were systematically investigated by X-ray diffraction, transmitting electron microscopy and mechanical testing. It is indicated that the structural stability, microstructure and mechanical behavior of Ti-1023 alloy are closely related to the cold deformation and heat treatment. Regardless of the solution treatments in single β phase region (833 ℃) or α + β phase region (753 ℃), double yielding occurs in the stress-strain curves of the alloy. This suggests that the β phases in the alloys with above solution treatments possess low structural stability, and stress induces β→α" martensitic transformation, leading to double yielding behavior. Severe cold rolling deformation and stress/strain induced martensitic transformation gives rise to the refinement of β grains and martensite variants. Since numerous dislocations and grain/phase boundaries induced by severe cold deformation can be used as nucleating sites for the precipitation of α phase, a large amount of fine α phase is precipitated out of the cold rolled Ti-1023 alloy after short aging at 550 ℃, therefore,the alloy exhibits a good balance between strength and ductility.

Abstract Background Spinal anesthesia is optimal choice for transurethral resection of the prostate (TURP), but the sensory block should not cross the T10 level. With advancing age, the sensory blockade level increases after spinal injection in some patients with spinal canal stenosis. We optimize the dose of spinal anesthesia according to the decreased ratio of the dural sac cross-sectional area (DSCSA), the purpose of this study is to hypothesis that if DSCSA is an effective parameter to modify the dosage of spinal anesthetics to achieve a T10 blockade in geriatric patients undergoing TURP. Methods Sixty geriatric patients schedule for TURP surgery were enrolled in this study. All subjects were randomized divided into two groups, the ultrasound (group U) and the control (group C) groups, patient receive either a dose of 2 ml of 0.5% isobaric bupivacaine in group C, or a modified dose of 0.5% isobaric bupivacaine in group U. We measured the sagittal anteroposterior diameter (D) of the dural sac at the L3–4 level with ultrasound, and calculated the approximate DSCSA (A) according to the following formula: A = π(D/2)2, ( π = 3.14). The modified dosage of bupivacaine was adjusted according to the decreased ratio of the DSCSA. Results The cephalad spread of the sensory blockade level was significantly lower (P

Objective: The purpose of this study was to investigate the lifetime suicide attempt rate, clinical characteristics and cognitive function of Chinese patients with chronic schizophrenia who had attempted suicide. Methods: We collected data from 908 schizophrenia inpatients about suicide attempts through interviews with the patients and their families, as well as through medical records. All patients were assessed with the Positive and Negative Syndrome Scale, the Rating Scale for Extrapyramidal Side Effects, the Abnormal Involuntary Movement Scale, and the Repeated Battery for the Assessment of Neuropsychological Status. Results: Of this sample, 97 (10.68%) had attempted suicide. Patients who had attempted suicide were younger, had longer illness duration, and more severe general psychopathology and depressive symptoms than those who had not. Logistic regression analysis confirmed that suicide attempts were correlated with age, smoking, and depression. No cognitive performance differences were observed between patients who had and had not attempted suicide. Conclusions: In China, patients with chronic schizophrenia may have a higher prevalence of lifetime suicide attempts than the general population. Some demographic and clinical variables were related to suicide attempts in patients with chronic schizophrenia.

The effect of YSZ+NiCrAl-B.e composite coating on the ignition resistance of TC11 titanium alloy was studied by using the method of friction in oxygen-enriched atmosphere. Combining friction and wear analysis and unsteady heat conduction calculation, the fireproof mechanism of the composite coating was discussed. The results show that the YSZ+NiCrAl-B.e composite coating significantly improves the ignition resistance of the titanium alloy, and its critical ignition oxygen concentration is about 2.3 times than that of the bare titanium alloy. The friction property of the friction pair composed of the titanium alloy and the composite coating is higher than that of the friction pair composed of titanium and titanium alloy; And the effect of NiCrAl-B.e layer on the ignition resistance of the titanium alloy is not obvious. In the process of friction ignition, the YSZ layer can significantly reduce the temperature rise of the titanium alloy substrate though preventing the rapid heat transfer, delaying the ignition of the titanium alloy. In this sense, the YSZ layer is the flame retardant layer in the coating system, and heat barrier is the main fireproof mechanism.

The 600℃ high temperature titanium alloy composite with graphene oxide addition was prepared by temperature-controlled mixing method and hot isostatic pressing. Microstructure and mechanical properties of composite were studied by metallographic observation, energy spectrum analysis, phase analysis and tensile test. The results show that graphene oxides are dispersed uniformly in the 600℃ high temperature titanium alloy powder when the content of graphene oxide is 0.3%(mass fraction) and the main mode of action is physical adsorption. Compared with the alloy without graphene oxide, the microstructure of the composite with 0.3% graphene oxide is obviously refined, and the average size of equiaxed alpha phase is reduced by 36%. Meanwhile, the average room temperature tensile strength and yield strength increase by 7.8% and 10.4% respectively and Vickers hardness increases by 25.6%. The strengthening mechanisms of graphene oxide on 600℃ high temperature titanium alloy mainly include grain refinement strengthening,dislocation streng-thening and precipitation strengthening of the (TiZr)6Si3 second-phase.

Dexmedetomidine can effectively decrease the incidences of emergence agitation (EA) in adult patients, but there are major side effects related to increased dose of dexmedetomidine. The purpose of this study was to determine the median effective dose of dexmedetomidine in the prevention of EA among geriatric patients undergoing major open surgery with general anesthesia. A total of 50 geriatric patients were enrolled in this study. Dexmedetomidine 0.5 μg·kg −1 ·h −1 continuous intravenous infusion was administered to the first patient. The next dose was increased or decreased by .05 depending on the response of the previous patient, according to the Dixon up-and-down method. An “effective” or “ineffective” response was determined based on the Riker sedation-agitation score (RSAS), we defined “effective” as RSAS

The low cycle fatigue (LCF) property and low cycle dwell fatigue (LCDF) property of bimodal structure and lamellar structure for Ti60 titanium alloy under high peak stress were studied by means of optical microscope (OM), scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The results show that microstructure has little effect on LCF property, while significantly influences LCDF property. The dwell fatigue sensitivity of bimodal structure is higher than that of lamellar structure. Under dwell loading condition, the fatigue life decreases remarkably. The fatigue life decreases with the increase of the peak stress, while the dwell fatigue sensitivity increases. Within the same cycle, plastic strain accumulation of LCDF is greater than that of LCF, and the plastic strain accumulation of bimodal structure is more than that of lamellar structure. The LCF crack initiates at the specimen surface with single source, while LCDF crack originates inside of specimen with multiple sources. There are quasi-cleavage facets on the fracture surface. The density of facets for bimodal structure is higher than that of lamellar structure.

NiCrAl/YSZ/NiCrAl-B. e composite coating on TC11 titanium alloy was combusted by friction in oxygen-enriched atmosphere. The combustion products were studied by XRD, SEM, EDS and EPMA. The effect of the composite coating on the combustion behavior of TC11 titanium alloy was discussed. The results show that there is regional microstructural evolution along radial direction in the substrate of the combusted specimen. The substrate near the central hole is the ignition source. When the combustion degree is low, the effect of the YSZ intermediate layer on the combustion behavior of titanium alloys can be ignored. However, when the combustion degree is high, the YSZ intermediate layer dissolves greatly in the titanium alloy melt through decomposition reaction, which provides O and Zr for the titanium alloy melt and accelerates the interaction between Ti and O. Furthermore, the ZrTiO4 combustion product has a worse ability to block oxygen diffusion than TiO2. As a result, NiCrAl/YSZ/NiCrAl-B. e composite coating, especially the YSZ layer, promotes the ext-ended combustion of TC11 titanium alloy.

The effects of both the microstructure and the original grain size on three-roll screw rolling process of Ti6Al4V titanium alloy bar were studied in the present work. The microstructure of Ti6Al4V titanium bar had a great influence on the mechanical properties of the rolling bar. When the original size was large, the grains were apparently refined but the microstructure was uneven. But for semi-finished titanium bar composed of fine equiaxed grains, the grains after rolling were fine and uniform. During the rolling process, the Ti6Al4V titanium alloy microstructure changed from equiaxed structure to the basket-weave one. After annealing at 800℃ for 1.5 hours and then cooling in air, the average tensile strength decreased from 984 MPa to 964 MPa; while after annealing at 950℃ for 1.5 hours and then cooling by water, and aging at 540℃ for 6 hours then cooling by air, the average tensile strength increased from 979 MPa to 1107 MPa.

To analyze the relationship between composition, microstructure and mechanical properties of TA15 titanium alloys, the quasi-static tensile properties and dynamic properties at room temperature of four kinds of TA15 titanium alloys were studied by the electronic universal tensile testing machine and split hopkinson pressure bar (SHPB). The results reveal that the Zr content has little effect on the tensile strength at room temperature, moreover, with the increase of content of main alloy elements Al, V and Mo, the content of primary α phase decreases and the lamella width of secondary α phase is thinner which provide higher strength and lower plasticity. Slight changes in alloy composition have little effect on dynamic mechanical properties within the critical strain rate range. Increasing the content of main alloy elements Al, Zr, V and Mo is beneficial to improve the critical strain rate, at which the alloy has excellent dynamic mechanical properties. For equiaxed TA15 titanium alloys obtained under air cooling condition, the smaller volume fraction of primary α phase and thinner lamella of secondary α phase can improve the tensile strength, critical strain rate and dynamic mechanical properties at room temperature.

As one kind of near alpha titanium alloys with excellent mechanical properties, Ti6242 alloy always shows the“dwell fatigue”characteristic, which is similar to other near α or α+β titanium alloys, especially at near room temperature. In this study, the low cycle fatigue and dwell fatigue tests under high load were designed according to the law of dwell fatigue sensitivity rising with the increase of test load. Combining with microstructure observation, mechanical property characterization and failure fracture analysis, the relationship between the microstructure and fracture behavior under high load low cycle fatigue and dwell fatigue tests was analyzed systematically. By summarizing the characteristics of failure fracture under room temperature tensile, high load low cycle fatigue test and high load dwell fatigue test, also comparing the dwell fatigue sensitivity of the Ti6242 alloy in this study with other Ti6242 alloys and other titanium alloys under different loading conditions, it is proved that increasing the fatigue load is a feasible way to characterize the dwell fatigue sensitivity of Ti6242 alloy.

In order to understand the cooling procedure of aviation engine blade after titanium combustion, the finite element method was used to simulate the temperature and fluid field of ROTOR37 model after combustion occurred with 550℃ fire proof titanium alloy(TF550 titanium alloy) and 600℃ high temperature titanium alloy(TA29 titanium alloy), respectively. The results show that the relative mach number influences the cooling procedure of blade, the cooling performance at the area of mach number about 0.7-1 is much higher than other area; compared with the leading edge, the cooling process of the tip is more complex, and the cooling rate is an order of magnitude lower than that of the leading edge. The difference of cooling temperature between TF550 titanium alloy and TA29 titanium alloy at tip combustion area is quite observable; and the maximum value occurs within the scope of 1000-2500K; the former is more than 100K lower than the latter, the value is reduced into 30K within the scope of 300-500K. The temperature distortion of the flow field would increase the intensity of the surge, the effect of combustion on the surge margin should be fully considered during the design of the blade.