Hypermethylation of Bmp2 and Fgfr2 Promoter Regions in Bone Marrow Mesenchymal Stem Cells Leads to Bone Loss in Prematurely Aged Mice.

Osteoporosis is an age-related, systemic skeletal disease that poses a significant public health challenge in contemporary society. Development at the epigenetic level is emerging as an important pathogenic mechanism of osteoporosis. Despite indications of a robust association between DNA methylation and osteoporosis development, a comprehensive understanding of the specific role of DNA methylation in osteoporosis remains limited. In this study, significant bone loss was detected at the beginning of eight weeks of age in mouse models of premature aging (SHJHhr mice). We identified a notable upregulation of DNA methyltransferase 3b/3l (Dnmt3b/l) and downregulation of ten eleven translocation dioxygenase 1 (Tet1) in bone marrow mesenchymal stem cells (BMSCs) isolated from SHJHhr mice, along with an increase in the overall 5-methylcytosine (5mC) levels. Moreover, methylation capture sequencing revealed genomic hypermethylation in SHJHhr mice BMSCs. Integrated methylome and transcriptome analyses revealed several crucial methylated genes and networks that are potentially associated with osteoporosis development. Notably, elevated methylation levels of genes linked to the Wnt signaling pathway, particularly bone morphogenetic protein 2 (Bmp2) and fibroblast growth factor receptor (Fgfr2), appeared to compromise the osteogenic differentiation potential of BMSCs. Concurrently, DNA methyltransferase inhibitors attenuated the methylation of the promoter regions of Bmp2 and Fgfr2 and rescued the osteogenic differentiation potential of the BMSCs from SHJHhr mice. In summary, our study provides novel insights into the role of DNA methylation in the development of osteoporosis and suggests promising prospects for employing epigenetic interventions to manage osteoporosis.

Cation-Loaded Porous Mg2+-Zeolite Layer Direct Dendrite-Free Deposition toward Long-Life Lithium Metal Anodes.

Lithium metal, with ultrahigh theoretical specific capacity, is considered as an ideal anode material for the lithium-ion batteries. However, its practical application is severely plagued by the uncontrolled formation of dendritic Li. Here, a cation-loaded porous Mg2+-Zeolite layer is proposed to enable the dendrite-free deposition on the surface of Li metal anode. The skeleton channels of zeolite provide the low coordinated Li+-solvation groups, leading to the faster desolvation process at the interface. Meanwhile, anions-involved solvation sheath induces a stable, inorganic-rich SEI, contributing to the uniform Li+ flux through the interface. Furthermore, the co-deposition of sustained release Mg2+ realizes a new faster migration pathway, which proactively facilitates the uniform diffusion of Li on the lithium substrate. The synergistic modulation of these kinetic processes facilitates the homogeneous Li plating/stripping behavior. Based on this synergistic mechanism, the high-efficiency deposition with cyclic longevity exceeding 2100 h is observed in the symmetric Li/Li cell with Mg2+-Zeolite modified anode at 1 mA cm-2. The pouch cell matched with LiFePO4 cathode fulfills a capacity retention of 88.4% after 100 cycles at a severe current density of 1 C charge/discharge. This synergistic protective mechanism can give new guidance for realizing the safe and high-performance Li metal batteries.

3D Printing Manufacturing of Lithium Batteries: Prospects and Challenges toward Practical Applications.

The manufacturing and assembly of components within cells have a direct impact on the sample performance. Conventional processes restrict the shapes, dimensions, and structures of the commercially available batteries. 3D printing, a novel manufacturing process for precision and practicality, is expected to revolutionize the lithium battery industry owing to its advantages of customization, mechanization, and intelligence. This technique can be used to effectively construct intricate 3D structures that enhance the designability, integrity, and electrochemical performance of both liquid- and solid-state lithium batteries. In this study, an overview of the development of 3D printing technologies is provided and their suitability for comparison with conventional printing processes is assessed. Various 3D printing technologies applicable to lithium-ion batteries have been systematically introduced, especially more practical composite printing technologies. The practicality, limitations, and optimization of 3D printing are discussed dialectically for various battery modules, including electrodes, electrolytes, and functional architectures. In addition, all-printed batteries are emphatically introduced. Finally, the prospects and challenges of 3D printing in the battery industry are evaluated.

Qualitative Classification of Lubricating Oil Wear Particle Morphology Based on Coaxial Capacitive Sensing Network and SVM.

In addition to lubricating and cooling, aero-engine lubricating oil is also a transport medium for wear particles generated by mechanical wear. Online identification of the number and shape of wear particles is an important means to directly determine the wear state of rotating parts, but most of the existing research focuses on the identification and counting of wear particles. In this paper, a qualitative classification method of wear particle morphology based on support vector machine is proposed by using the wear particle capacitance signal obtained by the coaxial capacitive sensing network. Firstly, the coaxial capacitive sensing network simulation model is used to obtain the capacitance signals of different shapes of wear particles entering the detection space of different electrode plates. In addition, a variety of intelligent optimization algorithms are used to optimize the relevant parameters of the support vector machine (SVM) model in order to improve the classification accuracy. By using the processed data and optimized parameters, a SVM-based qualitative classification model for wear particles is established. Finally, the validity of the classification model is verified by real wear particles of different sizes. The simulation and experimental results show that the qualitative classification of different wear particle morphologies can be achieved by using the coaxial capacitive sensing network signal and the SVM model.

The Effects of Ru4+ Doping on LiNi0.5Mn1.5O4 with Two Crystal Structures.

Doping of Ru has been used to enhance the performance of LiNi0.5Mn1.5O4 cathode materials. However, the effects of Ru doping on the two types of LiNi0.5Mn1.5O4 are rarely studied. In this study, Ru4+ with a stoichiometric ratio of 0.05 is introduced into LiNi0.5Mn1.5O4 with different space groups (Fd3¯m, P4332). The influence of Ru doping on the properties of LiNi0.5Mn1.5O4 (Fd3¯m, P4332) is comprehensively studied using multiple techniques such as XRD, Raman, and SEM methods. Electrochemical tests show that Ru4+-doped LiNi0.5Mn1.5O4 (P4332) delivers the optimal electrochemical performance. Its initial specific capacity reaches 132.8 mAh g-1, and 97.7% of this is retained after 300 cycles at a 1 C rate at room temperature. Even at a rate of 10 C, the capacity of Ru4+-LiNi0.5Mn1.5O4 (P4332) is still 100.7 mAh g-1. Raman spectroscopy shows that the Ni/Mn arrangement of Ru4+-LiNi0.5Mn1.5O4 (Fd3¯m) is not significantly affected by Ru4+ doping. However, LiNi0.5Mn1.5O4 (P4332) is transformed to semi-ordered LiNi0.5Mn1.5O4 after the incorporation of Ru4+. Ru4+ doping hinders the ordering process of Ni/Mn during the heat treatment process, to an extent.

Synthesis and Electrochemical Characterization of LiNi0.5Co0.2Mn0.3O2 Cathode Material by Solid-Phase Reaction.

In this paper, using four carbonates as raw materials, the cathode material LiNi0.5Co0.2Mn0.3O2 was prepared with the "ball milling-calcining" solid-phase synthesis method. The specific reaction process, which consists of the decomposition of the raw materials and the generation of target products, was investigated thoroughly using the TG-DSC technique. XRD, SEM and charge/discharge test methods were utilized to explore the influence of different sintering temperatures on the structure, morphology and electrochemical performance of the LiNi0.5Co0.2Mn0.3O2 cathode. The results show that 900~1000 °C is the appropriate synthesis temperature range. LiNi0.5Co0.2Mn0.3O2 synthesized at 1000 °C delivers optimal cycling stability at 0.5 C. Meanwhile, its initial discharge specific capacity and coulomb efficiency reached 167.2 mAh g-1 and 97.89%, respectively. In addition, the high-rate performance of the cathode sample prepared at 900 °C is particularly noteworthy. Cycling at 0.5 C, 1 C, 1.5 C and 2 C, the corresponding discharge specific capacity of the sample exhibited 148.1 mAh g-1, 143.1 mAh g-1, 140 mAh g-1 and 138.9 mAh g-1, respectively.

Research on the Comprehensive Evaluation Method for the Automatic Recognition of Raman Spectrum under Multidimensional Constraint.

Raman spectrum contains abundant substance information with fingerprint characteristics. However, due to the huge variety of substances and their complex characteristic information, it is difficult to recognize the Raman spectrum accurately. Starting from dimensions like the Raman shift, the relative peak intensity, and the overall hit ratio of characteristic peaks, we extracted and recognized the characteristics in the Raman spectrum and analyzed these characteristics from local and global perspectives and then proposed a comprehensive evaluation method for the recognition of Raman spectrum on the basis of the data fusion of the recognition results under multidimensional constraint. Based on the common spectrum database of the normal Raman and surface-enhanced Raman of thousands of substances, we analyzed the performance of the evaluation method. It shows that even for the identification of spectra from instruments of low technical specifications, the automatic recognition rate of the sample can reach 98% and above, a great improvement compared with that of the common identification algorithms, which proves the effectiveness of the comprehensive evaluation method under multidimensional constraint.

A New In Situ Coaxial Capacitive Sensor Network for Debris Monitoring of Lubricating Oil.

Wear debris monitoring of lubricant oil is an important method to determine the health and failure mode of key components such as bearings and gears in rotatory machines. The permittivity of lubricant oil can be changed when the wear debris enters the oil. Capacitive sensing methods showed potential in monitoring debris in lubricant due to the simple structure and good response. In order to improve the detection sensitivity and reliability, this study proposes a new coaxial capacitive sensor network featured with parallel curved electrodes and non-parallel plane electrodes. As a kind of through-flow sensor, the proposed capacitive sensor network can be in situ integrated into the oil pipeline. The theoretical models of sensing mechanisms were established to figure out the relationship between the two types of capacitive sensors in the sensor network. The intensity distributions of the electric field in the coaxial capacitive sensor network are simulated to verify the theoretical analysis, and the effects of different debris sizes and debris numbers on the capacitance values were also simulated. Finally, the theoretical model and simulation results were experimentally validated to verify the feasibility of the proposed sensor network.

Development of shipboard automatic flow injection analysis-Surface-enhanced Raman spectroscopy instrument toward onsite detection of trace polycyclic aromatic hydrocarbons in water environment.

The qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) has been important for the environmental control of persistent organic pollutants for decades. Considering the potential risk of deterioration, degradation, and external pollution during transportation, the development of rapid and onsite detection of trace PAHs is in demand. Here, taking the advantage of high sensitivity of surface-enhanced Raman spectroscopy (SERS), we developed a shipboard instrument by combining a portable Raman instrument and a flow injection device, integrating the sample pretreatment and target detection step by step. The feasibility of the instrument was demonstrated by detecting trace benzo[a]pyrene from different water environments with the lowest detection concentration less than 1 µg/l. The reliable stability and repeatability indicate that in the case of emergency response, the developed flow injection analysis-SERS instrument is very promising for the quantitative and qualitative analysis of diverse organic pollutants other than PAHs in water environments.

The Design and Verification of an Active SAMSR Ultrasonic Guided Wave Monitoring System with Ultra-Low Crosstalk.

Due to long propagation distance and high sensitivity to a variety of damages, ultrasonic guided wave technologies have been widely applied in the damage detection or health monitoring of pipe networks and large plate-like structures. However, there are two important problems to be solved when applying this technology; namely, the large scanning time required for monitoring large-scaled structures and the serious crosstalk between the actuation and receiving signals, especially when monitoring hot-spot regions. Therefore, this study mainly designed key parts, such as the matrix switcher and attenuation circuit. The single-actuation and multiple-simultaneous-reception (SAMSR) mechanism based on an analog switching matrix and a low noise charge amplifier circuit was designed and integrated with the SPI control bus to shorten the scanning time. Moreover, a two-stage attenuation circuit with an interlocking isolation structure is presented to effectively isolate the receiving signals from the actuation signals to obtain ultra-low crosstalk even under a high voltage actuation source. In this study, the designed matrix switcher and other components were integrated into the developed ultrasonic guided wave monitoring system. Several experiments were conducted on a stiffened composite structure to illustrate the effectivity of the developed SAMSR ultrasonic guided wave system by comparing the signals collected with those from a commercial ultrasonic guided wave system.

Ti-Doped Tunnel-Type Na4Mn9O18 Nanoparticles as Novel Anode Materials for High-Performance Supercapacitors.

Nanomaterials with tunnel structures are extremely attractive to be used for electrode materials in electrochemical energy storage devices. Tunnel-structured Ti-doped Na4Mn9O18 nanoparticles (TNMO-NPs) were synthesized by a facile and high-production method of the solid-state reaction with a high-energy ball-milling process. As electrode materials in the supercapacitor cell, the as-synthesized TNMO-NPs exhibit a high specific capacity of 284.93 mA h g-1 (0.57 mA h cm-2/1025.75 F g-1). A superior rate capability with a decay of 36% is achieved by increasing the scan rates from 2 to 25 mV s-1. To further explore the storage mechanism of Ti-doped Na4Mn9O18 materials, density functional theory (DFT) calculations were used to calculate the activation energy for the ion immigration in the electrode, and the results show that the minimum ion diffusion barrier energy is 0.272 eV, indicating that the sodium ions could insert into the system easily. Through the scan-rate-dependent cyclic voltammetry analysis, the capacity value indicates a mixed charge storage of capacitive behavior and Na+ intercalation progress. A maximum energy density of 77.81 W h kg-1 at a power density of 125 W kg-1 is achieved, and a high energy density of 54.79 W h kg-1 is maintained even at an ultrahigh power density of 3750 W kg-1. The TNMO-NP supercapacitors show excellent flexibility at various bent (0-180°) states. The capacitive performance of the TNMO-NPs makes them promising cathode materials for flexible supercapacitors with high specific capacities and high energy densities.

Measurement and Time Response of Electrohydrodynamic Direct-Writing Current.

The micro/nano current is an important characteristic to reflect the electrohydrodynamic direct-writing (EDW) process. In this paper, a direct-written current measurement system with a high signal to noise ratio was proposed to monitor the charged jets, providing the data basis for the promotion of stability and precision of the EDW jet. The electrical characteristics of the printing process were studied, the electrohydrodynamic direct-written current was associated with the stability of charged jet and the accuracy of direct-written patterns. There was an impulse current when the front end of the jet reached the collector and then a stable jet could be gained. With the increase of applied voltage, the severe fluctuation of measured current increased, the charged jet became more unstable and the accuracy of direct-written parallel lines was lower. The effects of processing parameters on direct-written current were also investigated. The average direct-written current at the stable stage increased as the applied voltage and polymer concentration increased, and it decreased as the distance from the nozzle to the collector increased. This research will promote the development and applications of EDW technology in the fields of micro/nano manufacturing.

Electrochemical synthesis of phosphorus-doped graphene quantum dots for free radical scavenging.

In this work, phosphorus-doped graphene quantum dots (P-GQDs) with a high phosphorus doping content (>7 at%) are synthesized via an electrochemical approach. Sodium phytate (C6H6Na12O24P6), a green food antioxidant additive, is used as the electrolyte for providing both a phosphorus source and an electrolysis environment. The obtained P-GQDs exhibit excellent scavenging activity of free radicals, such as hydroxyl radicals (˙OH) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Combined with Raman, FT-IR, and XPS spectral analyses, the reason for high phosphorus content and the mechanism of free radical scavenging of P-GQDs are investigated in our work.

[A method for automatic selection of optimal standard hip stems].

In a hip replacement case when a standard hip stem is chosen, it is rough to select hip stems before operation, thus some stand-up standard hip stems should be prepared. The operation time is usually prolonged. In order to solve this problem, this paper presents a method to automatically select optimal standard hip stems by computers. Femoral anatomical data of a patient are acquired from X-ray films. Based on these anatomical data and a database of average cross-sections in proximal femurs, proximal femur of the patient can be reconstructed. This proximal femur model makes it possible to optimally select a standard hip stem. Theory analyses indicate that the method, presented in this paper, is practicable.

[Computerized three-dimensional reconstruction and morphologic measurement of adult acetabulum bone structure].

OBJECTIVE: To set up three-dimensional reconstruction of acetabulum bone structure from CT scanned image in computer with software of CAD and study quantitatively the morphologic features of the acetabulum. METHODS: Through the process of CT scanning, and edge recording of the CT image, we made use of CAD software and Unigraphics software to reconstruct the 40 normal acetabulum bones for the radius of acetabulum (R), minimum thickness of medial wall of acetabulum (L), depth of Harris fossa (D) and maximum opening rim width in cross-sectional plane (W). RESULTS: The average R was 30.48 +/- 2.05 mm. The average L was 2.35 +/- 1.13 mm. The average D was 5.71 +/- 1.21 mm. The average W was 63.06 +/- 2.05 mm. There was a linear relationship between the R and the W, but no correlation between the R, the L and the D. CONCLUSIONS: There was a significance linear relationship between the R and the W in normal adult acetabulum. However no correlation between the R, the L and the D.

[Custom design of hip joint prostheses based on X-ray films].

A novel method for the design of hip joint prostheses based on X-ray films is introduced. Only arcs and straight-lines form figures of hip joint prostheses. Because geometrical tolerances of manufacturing hip joint prostheses matching section are usually not strict, hip joint prostheses can be manufactured without CNC machine tool. Three hip joint prostheses for three different femurs were designed through a program which was developed by the present authors. Approximate marrow cavities of these femurs were simulated according to a standard database about femur. These models of femur marrow cavities were used to verify the hip joint prostheses designed. These hip joint prostheses designed were manufactured and implanted into femurs respectively. Experimental results indicate that the novel method for the design of hip joint prostheses is practicable.

[Measurement and classification of geometric parameters in Chinese proximal femur].

This study sought to establish a set of hip prostheses for the Chinese population and improve the design guidelines for hip prostheses. 480 cadaveric adult femora were obtained for X-ray imaging. 21 geometric parameters of femora were sampled on the anteroposterior(AP) and mediolateral(ML) views of radiograph in conjunction with computer-aided image processing technology. The curves of canal of proximal femur were fitted and made statistics. Pattern recognition was used to classify these geometric parameters. The results of classification corresponded with the 10 groups of data for design. On the basis of the numerous set of data, the results and classification would serve as means and guidelines for optimizing the design of prosthetic components and so far as custom-built hip prosthetics.

A biomechanical investigation on the incorporation of cortical allograft in rabbit ulna defects.

OBJECTIVE: To explore the changes of biomechanic al properties of cortical allograft in different mechanical environments. METHODS: Cortical allograft was transplanted to each side of th e midshaft diaphyseal ulna of each one of 40 rabbits. The left transplanted allo graft underwent normal physiological load, while the right one underwent lower l oad. After animals were killed,specimens were taken for examination of bone mine ral density, bone porosity and maximal three-point-bend breaking load. RESULTS: The union strength of allograft-host bone junction wa s increased constantly; meanwhile, the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and a later recovery of its strength. In comparison, the union strength of the normally loaded graft -host bone construct was significantly higher than that of the lower loaded sid e at the 8th and 16th week after transplantation. At the 16th week, there was gr eater bone strength in normally loaded graft than that in lower loaded graft. CONCLUSIONS: The internal repair can lead to initial greater we akening of cortical allograft and later gradual recovery of its strength. The ef fect of physiological load can accelerate the improvement of the biomechanical p rope rties of allograft.