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When a single-phase ground fault occurs, the transient zero sequence current will significantly increase. So, it is possible to detect whether a single-phase grounding fault has occurred in the transmission line by calculating and comparing the amplitude of transient zero sequence current. Only when the amplitude of the zero sequence voltage under the steady-state power frequency is greater than the preset threshold can the line selection device be effectively and reliably started. The instantaneous value protection device can also be used to start first, and then, the steady-state amplitude of the power frequency can be compared as the verification object. [ABSTRACT FROM AUTHOR]

In the semi‐airborne frequency domain electromagnetic detection, strong noise will be generated due to the attitude change of the receiving coil sensor. However, the existing attitude measurement system cannot be directly used in the semi‐airborne frequency domain electromagnetic system because of the requirement on the volume and accuracy of the instrument. In order to reduce the effect of attitude noise, this paper analyzes the cause and influence of attitude noise in the semi‐airborne frequency domain electromagnetic system, and presents the attitude noise correction method based on coefficient rotation matrix and Kalman algorithm. A high‐performance attitude sensor based on (Micro‐Electro‐Mechanical System (MEMS) technology is used to design an attitude measurement system for the semi‐airborne frequency domain electromagnetic system. The calculated result shows that the required accuracy of the roll angle and pitch angle of the attitude measurement system is less than 0.1°, whereas the required accuracy of the yaw angle is lower. In the field application, the apparent resistivity results show that the imaging profile corrected by attitude error is more consistent with local geological data than that without correction. Consequently, the attitude measurement system and correction method proposed in this paper can improve the detection accuracy of the semi‐airborne frequency domain electromagnetic system significantly. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Frequency‐domain electromagnetic (FDEM) instruments are effective tools for detecting underground electrical abnormal targets. However, due to the influence of various noises in the detection process, would lead to l poor signal‐to‐noise ratio of the system and would ultimately affect the detection accuracy. And FDEM detection systems have a defined measuring range. Excessive noise will lead to saturation of the system acquisition and distortion of the measurement. Because of the above problems, an acquisition technique for the FDEM receiving system is proposed to achieve noise suppression in the detection process. The scheme proposes a multi‐frequency LC filtering circuit to optimize the analog signal acquisition module of the receiver system. The circuit converts the measured voltage signal into a current signal, improving the system's immunity to interference. At the same time, the noise of non‐target frequencies in the measured signal is suppressed, avoiding saturation of the receiving system acquisition, and realizing high signal‐to‐noise acquisition of multiple target frequencies. First, the principle of circuit design is analyzed, and the design flow of circuit parameters is proposed. Further, the validity of the design is verified via simulation results. Finally, the optimization scheme is validated with an actual circuit. The results show that for the measurement environment set in this paper, this optimization scheme can suppress the noise of non‐target frequency in the measured signal, so that the noise amplitude can be reduced by more than 90%, and the signal‐to‐noise ratio of the filtered signal can be improved by 23.35 dB. This study helps to facilitate FDEM instruments to achieve high signal‐to‐noise ratio detection. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Nuclear power components contain radioactivity on their surfaces after long-term service, which can be harmful to personnel and the environment during maintenance, dismantling, and decommissioning. In this experiment, laser decontamination technology is utilized to remove radioactivity from their surfaces. In order to meet the actual needs, a laser decontamination process without spot overlapping has been studied. Under the same equipment conditions, the decontamination efficiency of the non-spot overlapping process is 10 times higher than that of the spot overlapping process. Alloy 690 is used as the test substrate, and non-radioactive specimens are prepared by simulating primary-circuit hydrochemical conditions. The surface morphology, elemental composition, and phase composition of the specimens before and after laser decontamination are investigated with SEM and XRD using the single-pulse experiment and power single-factor experiment methods, and the laser decontamination effect was evaluated. The results show that the decontamination efficiency reached 10.8 m2/h under the conditions of a pulse width of 500 ns, a laser repetition frequency of 40 kHz, a scanning speed of 15,000 mm/s, and a line spacing of 0.2 mm, according to which the removal effect was achieved when the laser power was 160 W and the oxygen content on the surface was 6.29%; additionally, there were no oxide phases in the XRD spectra after decontamination. Therefore, the laser cleaning process without spot overlap can provide reference for future practical operations to achieve efficient removal of radioactivity from nuclear power components. [ABSTRACT FROM AUTHOR]

Electrode induction melting gas atomization (EIGA) technology is a commonly used and effective method for producing spherical metal powders in additive manufacturing. In this paper, we aim to describe the atomization and fragmentation of liquid sheets from a typical swirl nozzle and highlight the primary breakup of titanium alloy powder production. We developed a computational fluid dynamics (CFD) approach to simulate the primary disintegration process of the molten metal using the volume of fluid (VOF) method coupled with the large eddy simulation turbulence model (LES). Our numerical results show that high-speed spraying creates supersonic airflow in the atomization chamber. Recirculation is the main area where primary atomization occurs. The formation of the recirculation zone is the direct driving force that allows atomization to proceed, which will increase turbulence intensity and achieve higher atomization efficiency. VOF-LES simulation can capture some qualitative results such as conical melt-sheet shape, wave formation, ligament formation, and perforation formation. The primary droplet size mainly ranges between 200 and 800 μm. Finally, with increasing gas pressure, the particle size of the atomized powder gradually decreases, and the particle size distribution becomes narrower. [ABSTRACT FROM AUTHOR]

A hybrid blockchain structure (hybrid directed acyclic graph, or H-DAG) is proposed in this article to solve the existing problem of blockchain architectures using symmetric key encryption technology by combining the characteristics of single-chain blockchains and DAG distributed ledgers. By improving the block and transaction structures and optimizing the consensus mechanism, the H-DAG confirmed transaction orders while maintaining the high-throughput characteristics of a DAG, thus solving the transaction order dependence problem. We introduced a lightweight PoW mechanism to the H-DAG to improve the anti-fork ability of the blockchain. An incentive mechanism was adopted in our model to compel honest nodes to be more enthusiastic about participating in, maintaining, and enhancing the security of a given network. The blockchain states achieved strong levels of consistency, and their transaction confirmation times were predictable. We evaluated the performance of the H-DAG by comparing and analyzing multiple experiments, and we modeled a forking attack strategy, verifying the resistance of the H-DAG to this attack strategy. The experimental results demonstrated that the order of transactions in the H-DAG was globally consistent, and the confirmation time of transactions was predictable. The H-DAG improved the anti-fork ability and enhanced the security of the blockchain to ensure a degree of decentralization of the blockchain system. Therefore, the system throughput was enhanced by improving the block structure using symmetric key technology. [ABSTRACT FROM AUTHOR]

Developing the large-scale preparation of non-noble metal catalysts with high performance is crucial for promoting the electrochemical production of hydrogen from water. In this work, a novel TiO2@FeNi2S4 (TiO2@FNS) branch nanoflake array on Ni foam can be prepared at a large scale (50 cm2) by combining an atomic-layer-deposited (ALD) TiO2 skeleton with one-step facile low-temperature (<100 °C) sulfurization method. As-prepared TiO2@FNS arrays exhibit excellent hydrogen evolution reaction (HER) performance with an overpotential of 97 mV at 10 mA cm−2, superior to the FNS counterpart (without TiO2 coating) and other reported catalysts. The enhanced HER catalytic performance of TiO2@FNS is attributed to the increased specific surface area and improved structural stability due to the introduction of TiO2 coating. Moreover, theoretical calculations also show that the bimetallic NFS structure is more favorable to the dissociation of water molecule and the desorption of H than the monometallic Ni3S2 counterpart. With the combination of experimental results and theoretical calculations, this work has enlightened a new way of exploring high-efficient catalysts for HER. [ABSTRACT FROM AUTHOR]

Machine translation is different from written translation. How to improve the performance of machine translation has been a research hotspot in current research on machine translation. In this paper, based on the semantic analysis and research of Japanese passive, a joint optimization algorithm of scheduling has been proposed, and the machine translation of Japanese passive has been studied. At present, machine translation is more and more widely used. Machine translation has solved many vocabulary problems, and it can complete a large amount of translation work and save a lot of manual translation time. While improving the translation speed, in the process of Japanese passive translation, it is also found that direct machine translation shows many shortcomings, and the quality of passive translation is not particularly ideal, exposing the basic problems of machine translation, such as semantic errors, syntactic errors, unclear and rigid expressions, and messy structures. In response to the problems above, this paper has improved the machine translation model for scheduling joint optimization algorithms. The paper has proposed several optimization algorithms and used resource awareness and computing power scheduling algorithms to conduct experimental analysis of translation performance. Finally, it is found that, among the two scheduling optimization algorithms, the resource-aware scheduling algorithm has better performance. With the same data, the resource-aware scheduling algorithm has saved 15.5% of the time compared with the computing power scheduling algorithm, and the accuracy of Japanese passive translation was 6%, 5%, and 21% higher than the computing power scheduling algorithm under different data volumes. Not only has the time taken been shortened, but the translation accuracy has also been improved. [ABSTRACT FROM AUTHOR]

In this study, twenty‐six peanut varieties and their cold‐pressed oils from eleven provinces in China were investigated for their oil content, acid value, peroxide value, fatty acid profiles, bioactive constituents, and induction period (IP) of lipid oxidation. Meanwhile, the effect of the geographical origin of peanut on the quality of cold‐pressed peanut oils (CPOs) was studied. The average acid value of CPOs in southern China was higher than that in northern China (0.49 mg KOH/g versus 0.22 mg KOH/g, p >.05). In addition, the average of oleic acid content, ratio of oleic acid to linoleic acid (O/L), and IP were also higher in southern China than that in northern China (p <.05). However, the average content of campesterol, β‐sitosterol, total phytosterol, linoleic acid, and ratio of unsaturated fatty acid to saturated fatty acid (UFA/SFA) exhibited reverse results (p <.05). At last, the comprehensive evaluation of CPOs based on principal component analysis (PCA) was performed. In all samples, Silihong from Liaoning province, northern China was No.1, and Zhonghua 21 from Xiaogan City, Hubei Province was No.4 which was the first one from southern China. Moreover, heat map clustering analysis further revealed the differences and similarities among different samples, and those results were in accordance with the comprehensive evaluation results. [ABSTRACT FROM AUTHOR]

For the exploration of shallow and small subsurface targets, rigid-beam helicopter-borne electromagnetic systems are often inconvenient or costly, whereas man-portable or ground-based systems are difficult to operate in complex terrain. An airborne concentric frequency-domain electromagnetic system with an unmanned rotorcraft as a flying platform is proposed to avoid the problems of low security in conventional helicopter-borne electromagnetic method and low efficiency in ground-based electromagnetic method for the exploration of shallow subsurface targets. Compared with the series mode of man-portable system, the currents of transmitting and bucking coils are assumed to be separately and continuously adjustable, which can reduce sensitivity of the small errors of the system. In this paper, the principle of canceling the primary magnetic field is analyzed. The design index of the physical parameters of the sensor is determined. The simulation experiment of layered earth model is carried out to verify the feasibility of the proposed system. [ABSTRACT FROM AUTHOR]

Bismuth oxide (Bi2O3) is an auspicious anode material for sodium-ion batteries owing to its high theoretical capacity and abundant Bi resources. However, the poor electronic conductivity and huge volume expansion of Bi2O3 during cycling lead to the low coulombic efficiency and unstable cycling stability. Aiming to suppress these issues, we use highly conductive reduced graphene oxide (rGO) as a continuous skeleton to fabricate a Bi2O3@rGO heterostructure. It exhibits high reversibility and stability for electrochemical sodium storage by delivering a reversible capacity of 161 mAh g−1 after 100 cycles at 50 mA g−1, which completely outperforms Bi2O3 (43 mAh g−1). In addition, the coulombic efficiency of the heterostructure stabilizes at >90% upon only 3 cycles. The results can be attributed to the dual function of rGO in supporting Bi2O3 nanoparticles and providing conductive pathways to fasten electron transport. [ABSTRACT FROM AUTHOR]

Delayed surface endothelialization is a bottleneck that restricts the further application of cardiovascular stents. It has been reported that the nature-inspired extracellular matrix (ECM) secreted by the hyaluronic acid (HA) micro-patterned smooth muscle cells (SMC) and endothelial cells (EC) can significantly promote surface endothelialization. However, this ECM coating obtained by decellularized method (dECM) is difficult to obtain directly on the surface of degradable magnesium (Mg) alloy. In this study, the method of obtaining bionic dECM by micro-patterning SMC/EC was further improved, and the nature-inspired ECM was prepared onto the Mg-Zn-Y-Nd (ZE21B) alloy surface by self-assembly. The results showed that the ECM coating not only improved surface endothelialization of ZE21B alloy, but also presented better blood compatibility, anti-hyperplasia, and anti-inflammation functions. The innovation and significance of the study is to overcome the disadvantage of traditional dECM coating and further expand the application of dECM coating to the surface of degradable materials and materials with different shapes. [ABSTRACT FROM AUTHOR]

For photovoltaic (PV) microgrid, the instability of PV power generation will bring a lot of trouble to the microgrid, it is a good solution to configure lithium-ion battery and the capacity configuration of lithium-ion battery is the key. This paper proposes a simple and feasible capacity configuration strategy for lithium-ion batteries, different from other studies; it optimizes the capacity configuration of batteries by abandoning extreme situations and further optimizes the capacity configuration according to the actual situation of microgrid load and PV. A microgrid consisting of an ~750 m2 factory with 50 kw PV is selected for analysis, the factory works from Monday to Saturday and rests on Sunday and the required battery capacity can be greatly optimized by adjusting the state of charge of the battery. After calculation, the strategy proposed in this paper requires a battery with only 375 kwh compared with the traditional strategy requiring 650 kwh, which can save ~42.3% of the cost and has good economic value. [ABSTRACT FROM AUTHOR]

Aiming at the shallow surface electromagnetic detection instrument system widely used in urban underground space exploration and underground target induction, a three-frequency resonance transmitting scheme is proposed to solve the problems of low efficiency in conventional single-frequency transmission method and high-voltage stress ($d\text{v}/d\text{t}$) in multifrequency pseudorandom transmission method. According to the specific transmitting coil and the required transmitting frequency, a three-frequency resonant matching circuit is designed to transmit the current signal with three frequency components, the fundamental and two low-order harmonics. Compared with 2n sequence pseudorandom transmitting mode, the current of resonant method is continuous without step, which reduces the influence on the received signal. In this article, the principle of three-frequency resonance is analyzed. The simulation experiment and laboratory test are carried out to verify the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

Intralipids are widely used to provide energy and necessary fatty acids for the patients. The structure of lipids may affect their function. We developed a bio‐catalyzed route to prepare various intralipids and investigated the protective effect of intralipids against α‐naphthylisothiocyanate (ANIT) induced liver injury rats, further discussing the structure–function relationship. The middle–long–middle (MLM) structural intralipid was synthesized through alcoholysis‐esterification, and the influence factors were investigated. ANIT treatment caused liver injury, further making hepatocyte damage, and increasing related biochemical indexes, like aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and total bilirubin (TBIL). Especially, MLM‐based and structoglyceride (STG) intralipids worked better in the early stage, to reduce the AST, ALT, and TBIL (p <.05). MLM showed a comparative advantage over other intralipids to accelerate the reduction of ALT (1st day) and AST (3rd day). MLM intralipid might be a promising next‐generation intralipid than the current STG intralipid liver‐injury patients. The biological catalysis MLM‐based intralipids can make the maximum utilization of fatty acids for the liver regeneration, where middle‐chain fatty acid (MCFA) in sn‐1,3 position can be metabolized directly to provide energy and long‐chain fatty acid (LCFA) in sn‐2 position can be delivered effectively for cell membrane repairing. [ABSTRACT FROM AUTHOR]

The ground–airborne frequency–domain electromagnetic (GAFDEM) method is a recently developed rapid detection approach for underground structures. However, the conventional apparent resistivity imaging in this method cannot meet the requirements of high precision and high efficiency detection for 3D targets. Therefore, we introduce the divergence of tipper vector (DTV) imaging to solve this problem with two orthogonal sources. First, we define DTV for the GAFDEM method, and then, we analyze the characteristics, advantages, and detection principles of DTV imaging using 3D models. Incorporating DTV imaging into the GAFDEM method allows us to directly distinguish the resistivity properties, position, and direction of an anomalous body more clearly and in less computing time, relative to apparent resistivity imaging. Thus, DTV imaging provides a fast detection method with high detection precision for a 3D anomalous body. This may effectively promote the development and application of the GAFDEM method and systems. [ABSTRACT FROM AUTHOR]

Meningioma is a prevalent intracranial malignancy known for its aggressive growth. Circular RNAs (circRNAs) play a crucial role in the development of various cancers. However, their involvement in meningioma remains understudied. This study aimed to investigate the function and underlying mechanism of hsa_circ_0004872 in meningioma. The molecular expression of hsa_circ_0004872, PD-L1 and EIF4A3 was identified by RT-qPCR and/or western blot assays. Cell viability, migration, and invasion were assessed through CCK-8 and Transwell assays, respectively. Cytotoxicity was determined using an LDH assay, and cell apoptosis was monitored by flow cytometry. The RNA and protein interactions were assessed through RNA-protein immunoprecipitation (RIP) and RNA pull down analyses. Our findings revealed that hsa_circ_0004872 expression was significantly downregulated in both meningioma tissue samples and cells. Overexpression of hsa_circ_0004872 inhibited the proliferation, metastasis, and immune escape of meningioma cells, as well as enhanced the cytotoxicity of CD8+ T cells by suppressing PD-L1. Furthermore, hsa_circ_0004872 directly interacted with EIF4A3, leading to the degradation of PD-L1 mRNA. Finally, inhibiting EIF4A3 improved the proliferation, metastasis, and immune escape of meningioma cells, as well as the cytotoxicity of CD8+ T cells. Our study demonstrated that hsa_circ_0004872 mitigated the proliferation, metastasis,and immune escape of meningioma cells by targeting the EIF4A3/PD-L1 axis. These findings suggested that hsa_circ_0004872 and EIF4A3 might serve as promising biological markers and therapeutic targets for meningioma treatment. Highlights: Hsa_circ_0004872 was downregulated in meningiomas and negatively correlated with PD-L1. Overexpression of hsa_circ_0004872 hindered the metastasis and immune escape of meningioma cells. Hsa_circ_0004872 competitively interacted to EIF4A3 to decay PD-L1 mRNA. EIF4A3 upregulation facilitated the metastasis and immune escape of meningioma cells. [ABSTRACT FROM AUTHOR]

In this paper, a noncontact laser ultrasonic method is proposed to determine the engineering constants of fiber reinforced composite. The method is based on the measurements of the transverse wave velocities as well as the longitudinal wave velocities. In the experiment, the unidirectional carbon fiber reinforced bismaleimide resin matrix composite is measured and the sample is equivalent to a transversely isotropic material. Two longitudinal wave propagation velocities and three transverse wave propagation velocities in two specific directions are measured, respectively. On this basis, all five independent elastic constants can be obtained according to the Christoffel equation. In the finite element analysis, the model of laser induced ultrasonic in the composites is established. The pulsed laser is equivalent to the surface load and the relationship between the physical parameters of the laser and the load is established by the correction coefficient. The numerical results match well with experimental measurements, which show that the method presented in this paper can achieve an accurate measurement of the elastic constants of fiber reinforced composite. [ABSTRACT FROM AUTHOR]

There is restricted research on the sensitive characteristic and detection ability analysis of semi-airborne frequency domain electromagnetic system at present. However, it is critical to the optimal design of the observation scheme, and it may be beneficial for the optimal selection of the record region and increasing the resolution of apparent resistivity imaging. So it is necessary to analyze the sensitive characteristic of the semi-airborne frequency domain system. In this paper, the primary electric field based on the closed-form expression of the electromagnetic field in the underground excited by a horizontal electric dipole is calculated, each element of the underground will be regarded as a current source, and the secondary magnetic field can be obtained based on tensor Green's function. The sensitivity is defined by the contribution of each element to the total secondary magnetic field at the receiving point, and the sensitivity distribution characteristic of the related region is analyzed. Numerical experiments reveal that the region with high sensitivity can produce a strong relative anomaly, and the contribution of the region with sensitivity near zero is almost negligible. To verify the analysis for sensitive characteristics and detectability, we have conducted a field test, after the design of the observation scheme, the data obtained reflects the underground fault zone well. Thus, the relationship between detectability and sensitivity is worth studying. • The sensitivity distribution characteristic of the related region for semi-airborne frequency domain system is analyzed. • The related region is analyzed with different combinations of the electrical, geometric and geological parameters. • The relationship between detectability and sensitive characteristics may help the optimal design of observation scheme. [ABSTRACT FROM AUTHOR]

The divergence of the tipper (DT) is an important imaging method characterized by fast imaging speed and high lateral resolution. It has been recently adopted from the natural source airborne electromagnetic method to the orthogonal electric sources ground-airborne frequency-domain electromagnetic method. However, the imaging characteristics and patterns of DT in the two methods are unclear due to significant differences in the sources used. The application of DT in ground-airborne frequency-domain electromagnetic method is limited. Therefore, this study first identifies the similarities and differences between the two methods from the theory. Furthermore, based on the same simulation model, the response characteristics of the DT excited by natural and orthogonal electric sources are investigated. The similarities and differences between the two methods are clarified. It will contribute to the rapid development and application of the DT imaging in ground-airborne electromagnetic detection method. [ABSTRACT FROM AUTHOR]

The aim of the present work was to study the applicability of rotating packed bed (RPB) for biodiesel through the biocatalytic method. In this research, the RPB facilitated a more homogeneous mixture of substrates due to its higher mass transfer efficiency and better micromixing environment. This was superior to the traditional continuous stirred tank reactor (CSTR) system. Candida sp. 99-125 lipase was used without any organic solvent or additive, and demonstrated a significant catalyst efficiency. The key factors, such as the high gravity factor (β), pattern of the catalyst and methanol-FFA molar ratio etc . were investigated. Under the optimal conditions, the hydrolysis yield of fatty acids was 97.0% after 24 h and the esterification yield of biodiesel was 96.0% 6 h later. The esterifying yield didn’t have an obvious decline in the fifth batch. Consequently, the RPB is an attractive and effective reactor for enzymatic synthesis. [ABSTRACT FROM AUTHOR]

Laser ultrasonic is a most promising method for non-destructive evaluation of residual stress. The residual stress of thin steel plate is measured by laser ultrasonic technique. The pre-stress loading device is designed which can easily realize the condition of the specimen being laser ultrasonic tested at the same time in the known stress state. By the method of pre-stress loading, the acoustoelastic constants are obtained and the effect of different test directions on the results of surface wave velocity measurement is discussed. On the basis of known acoustoelastic constants, the longitudinal and transverse welding residual stresses are measured by the laser ultrasonic technique. The finite element method is used to simulate the process of surface wave detection of welding residual stress. The pulsed laser is equivalent to the surface load and the relationship between the physical parameters of the laser and the load is established by the correction coefficient. The welding residual stress of the specimen is realized by the ABAQUS function module of predefined field. The results of finite element analysis are in good agreement with the experimental method. The simple and effective numerical and experimental methods for laser ultrasonic measurement of residual stress are demonstrated. [ABSTRACT FROM AUTHOR]

• Thermal treatment methods including explosion-puffing, microwave and roasting were used. • Explosion-puffed oil had higher content of tocopherols, lignans and phytosterols. • Microwaved oil contained maximum value for sesamol. • Explosion-puffing achieved the least effect on content of protein and most amino acids. This study investigated the impact of multiple thermal treatments (explosion-puffing, microwave, and roasting) on the processing qualities of sesame seeds and cold-pressed oil. The scanning electron microscopy (SEM) showed fissures and cavities of sesame seed surface upon thermal treatments. The microwave treatment promoted the maximum conversion of sesamolin into sesamol in the sesame oil. Compared with other treatments, explosion-puffing treatment resulted in most significant increases in the multiple beneficial phytochemicals, as well as in vitro antioxidant properties determined by 2,2-dipheny1-1-picrylhydrazyl radical (DPPH) radical scavenging activity, Ferric reducing antioxidant power (FRAP) and oxidative stability index (OSI). Additionally, thermal treatment processing caused varying degrees of damage of crude protein, total amino acids (TAA) and protein structure (tertiary and second structure). In which, explosion-puffing achieved minimal reduction in the first two indicators. Collectively, explosion-puffing might be a preferable thermal treatment method for industrial sesame processing with improved quality specifications. [ABSTRACT FROM AUTHOR]

The laser ultrasonic generation of Rayleigh surface wave and longitudinal wave in an elastic plate is studied by experiment and finite element method. In order to eliminate the measurement error and the time delay of the experimental system, the linear fitting method of experimental data is applied. The finite element analysis software ABAQUS is used to simulate the propagation of Rayleigh surface wave and longitudinal wave caused by laser excitation on a sheet metal sample surface. The equivalent load method is proposed and applied. The pulsed laser is equivalent to the surface load in time and space domain to meet the Gaussian profile. The relationship between the physical parameters of the laser and the load is established by the correction factor. The numerical solution is in good agreement with the experimental result. The simple and effective numerical and experimental methods for laser ultrasonic measurement of the elastic constants are demonstrated. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial dysfunction may play a central role in the pathologic process of Alzheimer’s disease (AD), but there is still a scarcity of data that directly links the pathology of AD with the alteration of mitochondrial DNA. This study aimed to provide a comprehensive assessment of mtDNA rearrangement events in AD brain tissue. Patients and Methods: Postmortem frozen human brain cerebral cortex samples were obtained from the Banner Sun Health Research Institute Brain and Body Donation Program, Sun City, AZ. Mitochondria were isolated and direct sequence by using MiSeq®, and analyzed by relative software. Results: Three types of mitochondrial DNA (mtDNA) rearrangements have been seen in post mortem human brain tissue from patients with AD and age matched control. These observed rearrangements include a deletion, F-type rearrangement, and R-type rearrangement. We detected a high level of mtDNA rearrangement in brain tissue from cognitively normal subjects, as well as the patients with Alzheimer's disease (AD). The rate of rearrangements was calculated by dividing the number of positive rearrangements by the coverage depth. The rearrangement rate was significantly higher in AD brain tissue than in control brain tissue (17.9%versus 6.7%; p = 0.0052). Of specific types of rearrangement, deletions were markedly increased in AD (9.2% versus 2.3%; p = 0.0005). Conclusions: Our data showed that failure of mitochondrial DNA in AD brain might be important etiology of AD pathology. [ABSTRACT FROM AUTHOR]

In this study, the different encapsulation methods involving emulsification and coaxial electrospinning were both utilized to fabricate a series of core/sheath composite, nanoparticles (NPs) and Nanofibers (NFs) separately, for drug delivery on potential biological and therapeutic applications. Bovine serum albumin (BSA) was employed as an active pharmaceutical ingredient model for core; poly(L-lactic acid) (PLLA) and methoxy poly(ethyleneglycol)-Poly lactic acid (mPEG-PLA) were selected as the encapsulation matrix for sheath. Attributed to the optimized fabrication procedures, the obtained NPs and NFs had the small average diameters and narrow size distributions with uniform structures and smooth surface morphologies. Based on the drug release profiles, both the NPs provided a burst release process followed by a drug diffusion manner, while for the NFs, the drug diffusion was the predominant factor in drug release. In particular, the mPEG-PLA NFs were fabricated with excellent hydrophilicity and highly neutralized surface resulting in a sustained release of BSA over 10 days. In addition, mPEG-PLA NFs also provided a better zero-order drug release profiles during the release time from 8 to 72 h, and a one-dimensional Fickian diffusion pattern during the whole BSA release period. A cytotoxicity study suggested that the two drug delivery systems were both safe to cells. In conclusions, the synergism of PEGylation with coaxial electrospinning may be an effective way to retard the release of drugs in a more sustained manner. [ABSTRACT FROM AUTHOR]

• Large-sized 0D-2D Cu 2 O @rGO composite is prepared as an anode material for SIBs. • Cu 2 O@rGO composite exhibits high reversible capacity. • Unique microspherical Cu 2 O exhibits excellent electrochemical kinetics during charge–discharge process. • Large-sized 0D-2D structural design strategy shows great potentials for SIBs. A cuprous oxide microspheres@reduced graphene oxide (Cu 2 O@rGO) composite is successfully prepared and used as an anode active material for sodium-ion batteries. In the hybrid structure, large-sized 0D Cu 2 O microspheres (∼500 nm) are distributed on highly conductive 2D rGO layers. The Cu 2 O@rGO electrode delivers a high reversible capacity of 273.2 mAh g−1 at a current density of 50 mA g−1 after 100 cycles, significantly higher than regular-sized (less than100 nm) Cu 2 O/rGO composite (185.9 mAh g−1) and bare Cu 2 O particles (95.8 mAh g−1). Even at 1 A g−1, Cu 2 O@rGO still demonstrates a capacity of 189 mAh g−1 after 1000 cycles. The enhanced electrochemical performance of Cu 2 O@rGO might be ascribed to the continuous and stable 3D network structure, which is transformed from the unique large-sized 0D-2D architecture after cycling. The as-fabricated hybrid structure shows great potentials in energy storage applications. [ABSTRACT FROM AUTHOR]

A new method for the reduction of iodosteroids to deoxysteroids has been developed using Zn, HCOOH and a catalytic amount of Aliquat 336 in water. In total, 13 iodosteroids were reduced in good to excellent yields. The higher solubilities of the substrates lead to the faster reactions, and the aqueous reaction was efficiently accelerated by granular polytetrafluoroethylene. The advantage of the aqueous system over eight organic solvents has also been demonstrated. [ABSTRACT FROM AUTHOR]

The frequency-domain controlled-source electromagnetic method (FDCSEM) has played an important role in the terrestrial and oceanic exploration. However, the measuring manners and the detecting abilities in two kinds of environment are much different. This paper analyses the electromagnetic theories of the FDCSEM exploration on land and in ocean, simulates the electromagnetic responses in the two cases based on a united physical and mathematical model, and studies the physical mechanism leading to these differences. In this study, the relationship between the propagation paths and the detecting ability is illuminated and the way to improve the detecting ability of FDCSEM is brought forward. In terrestrial exploration, FDCSEM widely adopts the measuring manner of controlled-source audio-frequency magnetotelluric method (CSAMT), which records the electromagnetic fields in the far zone in the broadside direction of an electric dipole source. This manner utilizes the airwave (i.e. the Earth surface wave) and takes the stratum wave as interference. It is sensitive to the conductive target but insensitive to the resistive one. In oceanic exploration, FDCSEM usually adopts the measuring manner of marine controlled-source electromagnetic method (MCSEM), which records the electromagnetic fields, commonly the horizontal electric fields, in the in-line direction of the electric dipole source. This manner utilizes the stratum wave (i.e. the seafloor wave and the guided wave in resistive targets) and takes the airwave as interference. It is sensitive to the resistive target but relatively insensitive to the conductive one. The numerical simulation shows that both the airwave and the stratum wave contribute to the FDCSEM exploration. United utilization of them will enhance the anomalies of targets and congregate the advantages of CSAMT and MCSEM theories. At different azimuth and different offset, the contribution of the airwave and the stratum wave to electromagnetic anomaly is different. Observation at moderate offset in the in-line direction is the best choice for the exploration of resistive targets, no matter the environment is land or shallow sea. It is also the best choice for the exploration of conductive targets in terrestrial environment. As for the conductive targets in shallow sea, observation at moderate offset in the broadside direction is better. Synthetic and felicitous utilization of the airwave and the stratum wave will optimize the performance of FDCSEM. [ABSTRACT FROM AUTHOR]

Natural gas hydrate is estimated to have huge reserves. Its exploitation can solve the global oil and gas shortage problem. Hydrates decompose into water and methane, and methane molecules are supersaturated to form nanobubbles. Methane nanobubbles can affect the decomposition efficiency of hydrates. They can provide abundant methane sources for the re-nucleation of hydrates. Molecular dynamics is employed in this study to investigate the decomposition process of type I methane hydrate and the formation of methane nanobubbles generated during decomposition under different methane mole fraction, pressures, and temperatures. The results indicate that external pressure inhibits the diffusion of methane molecules, thereby preventing the formation of nanobubbles. A higher mole fraction of methane molecules in the system requires a higher external pressure to generate stable nanobubbles after the decomposition of the hydrate structure. At 330 K, it is easy to form a nanobubble structure. Results of this study can help provide ideas for the study of efficient extraction and secondary nucleation of hydrates. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop anti-washout and fast-setting calcium-magnesium phosphate cement (as- CMP) by introducing white dextrin ( WD) and magnesium phosphate cement ( MPC) to CPC. The results showed that WD imparted anti-washout to the as- CMP paste, whereas MPC simultaneously improved the paste anti-washout and fast-setting. The synergistic effect of MPC and WD obviously shortened the setting time of as- CMP. The WD did not affect the phase evolution and microstructure of the paste. Furthermore, all samples were biocompatible and as- CMP exhibited the best cell metabolic activity, cell attachment, and proliferation, which would provide basic data for the clinical application. [ABSTRACT FROM AUTHOR]

Abstract: In this study, porous scaffolds made of magnesium phosphate (MP)/polycaprolactone (PCL) biocomposite were developed for bone tissue engineering applications. The composite scaffolds were fabricated by the particulate leaching method using sodium chloride particles as porogen. The obtained scaffold with porosity around 73% presents a porous structure with interconnected open pores. Hydrophilicity of the scaffolds was enhanced by the incorporation of MP component as demonstrated by the water contact angle measurement. The results of the in vitro degradation study show that the MP/PCL composite scaffolds degraded faster than PCL scaffolds in phosphate buffered saline (PBS). In addition, the degradation rate of the scaffolds could be tuned by adjusting the content of MP component in the composite. The results indicate that the MP/PCL composite scaffold has a potential application in bone tissue engineering. [Copyright &y& Elsevier]

Abstract: An ICPC with high structure recoverability and paste stability was successfully developed directly incorporating PEG-6000 into the liquid phase of CPC. The rheological behavior of ICPC was investigated with rheometric scientific ARES902-30004 controlled strain rheometer. Novel approaches of flow rate, shear thinning index (SI), shear stress slowdown (Δ τ) and thixotropy loop area have been applied to assess the injectability and structure recoverability of the ICPC paste. The addition of PEG-6000 to ICPC resulted in a thixotrophic structure with shortened setting time, slightly increased viscosity, larger thixotropic hysteresis loop area and lower Δ τ, with the improvement largely dependent on the PEG-6000 content. With acceptable injectability and shortened setting time, ICPC (1%) showed the lowest Δ τ and the highest SI, endowing the paste good structure recoverability and paste stability. The ICPC (1%) was bioactive and facilitated cell attachment and proliferation. The optimized ICPC (1%) paste with a relatively good structure stability and paste stability may serve as a good candidate for tooth root-canal fillings and percutaneous vertebroplasty in microinvasive surgery. [ABSTRACT FROM AUTHOR]

Abstract: Efficacious hemostatic agents have significant potential for use in rapid exsanguinating hemorrhage control by emergency medical technician or military medic nowadays. Unfortunately, the topical hemostats currently available in market still have various disadvantages. In this study, a series of macroporous chitosan coated mesoporous silica xerogel beads (CSSX) with good biocompatibility were developed. They consisted of mesoporous silica xerogel cores and chitosan layers with macroporous structure by using modified sol-gel process and PEG molecular imprinting technique. The textural properties of the CSSX beads were optimized by in vitro and in vivo evaluation for promoting blood clotting and the results indicated that the prepared CSSX beads can significantly accelerate the contact activation pathway of coagulation cascade and produce desirable hemostasis, with the best efficiency from the CSSX prepared with 2% chitosan and 5% PEG. Furthermore, these CSSX beads were observed to create no exothermic reaction and the subsequential tissue thermal injury by histological examination, and exhibited no obvious cytotoxicity even after 7 days. The results of the present study forward CSSX bead as a safe hemostatic system and present a platform for further optimization studies of materials with enhanced hemostatic capabilities for specific injury types. [ABSTRACT FROM AUTHOR]

Abstract: Ni–Co duplex coating has been successfully cladded on copper substrate by continuous wave CO2 laser. The average microhardness of cladded coating was 635 HV0.05, which was about 7 times of Cu substrate (92 HV0.05). During sliding wear tests, the volume loss of copper substrate was about 7 times of Ni–Co duplex coating at 60min. The high microhardness and crack free advantages of Ni–Co duplex coating, were favorable to reduce the plastic deformation and adhesive wear of copper substrate, resulting in the improvement of wear properties. [Copyright &y& Elsevier]

Abstract: Hydroxyapatite nanoparticles (HAPN) have been discovered to exert cytotoxicity and apoptosis-induction in some cancer cells. But it is still not clear how tumor cells interact with HAPNs with various sizes. In this study, we investigated the effect of the particle size of the HAPN on the anti-tumor activity, apoptosis-induction and the levels of the apoptotic signaling proteins in human hepatoma HepG2 model cells. HAPNs within 20–180nm size range were synthesized by a modified sol–gel method. The cellular internalization and biolocalization of the FITC-labeled HAPNs were also identified. The results showed that in HepG2 cells, the anti-tumor activity and HAPN-induced apoptosis strongly depended on the size of HAPNs, and the efficacies all decreased in the order of 45-nm>26-nm>78-nm>175-nm. HAPNs, ranging from 20nm to 80nm, were found to effectively activate caspase-3 and -9, decrease the Bcl-2 protein level, and increase the levels of Bax, Bid and the release of cytochrome c from mitochondria into cytoplasm, with the best efficiency from 45-nm HAPN. Correlating the cellular response with the cellular internalization, it can be inferred that the size of HAPN and thereby the cellular localization had predominant effect on the HAPN-induced cytotoxicity, apoptotis, and the levels of the apoptotic proteins in HepG2 cells. The findings presented here could provide new means to modulate the cellular behaviors of HAPN and to guide the design of HAPN-based delivery and therapeutic systems. [Copyright &y& Elsevier]

Abstract: Biodegradable microspheres have been widely used in drug/protein delivery system. In this paper, a modified ionotropic gelation method combined with a high voltage electrostatic field was developed to prepare protein-loaded chitosan microspheres. Bovine serum albumin (BSA) was chosen as a model protein. The preparation process and major parameters were discussed and optimized. The morphology, particle size, encapsulation efficiency and in vitro release behavior of the prepared microspheres were investigated. The results revealed that the microspheres exhibited good sphericity and dispersity when the mixture of sodium tripolyphosphate (TPP) and ethanol was applied as coagulation solution. Higher encapsulation efficiency (>90%) was achieved for the weight ratio of BSA to chitosan below 5%. 35% of BSA was released from the microspheres cured in 3% coagulation solution, and more than 50% of BSA was released from the microspheres cured in 1% coagulation solution at pH 8.8. However, only 15% of BSA was released from the microspheres cured in 1% coagulation solution at pH 4. The results suggested that ionotropic gelation method combined with a high voltage electrostatic field will be an effective method for fabricating chitosan microspheres for sustained delivery of protein. [Copyright &y& Elsevier]

Abstract: The effect of the PEG-grafted degree in the range of 0–30% on the in vitro macrophage uptake and in vivo biodistribution of poly(ethylene glycol)–poly(lactic acid)–poly(ethylene glycol) (PELE) nanoparticles (NPs) were investigated in this paper. The prepared NPs were characterized in terms of size, zeta potential, hydrophilicity, poly(vinyl alcohol) (PVA) residual on nanoparticles surfaces as well as drug loading. The macrophage uptake and biodistribution including plasma clearance kinetics following intravenous administration in mice of the NPs labeled by 6-coumarin were evaluated. The results showed that, except for the particles size, the hydrophilicity, superficial charges and in vitro phagocytosis amount of NPs are dependent on the PEG content in the copolymers greatly. The higher of the PEG content, the more hydrophilicity and the nearer to neutral surface charge was observed. And the prolonged circulation half-life (t 1/2) of the PELE NPs in plasma was also strongly depended on the PEG content with the similar trend. In particular for PELE30 (containing 30% of PEG content) NPs, with the lowest phagocytosis uptake accompanied the highest hydrophilicity and approximately neutral charge, it had the longest half-life in vivo with almost 12-fold longer and accumulation in the reticuloendothelial system organs close to 1/2-fold lower than those of reference PLA. These results demonstrated that the PELE30 NPs with neutral charge and suitable size has a promising potential as a long-circulating oxygen carrier system with desirable biocompatibility and biofunctionality. [Copyright &y& Elsevier]

Abstract: A major obstacle in the development of polymeric nanoparticles (NPs) as effective drug delivery vesicles is the rapid clearance from blood. In order to realize a significant prolongation in blood circulation, a combinatorial design, covalent attachment of polyethylene glycol (PEG) to polylactic acid (PLA) and physical adsorption of water-soluble chitosan (WSC) to particle surface, has been developed for surface modification of PLA NPs. Two types of WSC, cationic partially deacetylated chitin (PDC) and anionic N-carboxy propionyl chitosan sodium (CPCTS) were investigated. All the NPs formulated in the size range of 100–200nm were prepared by a modified w/o/w technique and physicochemically characterized. In vitro phagocytosis by mouse peritoneal macrophage (MPM), in vivo blood clearance and biodistribution following intravenous administration in mice, of these NPs labeled with 6-coumarin, were evaluated. The presence of WSC, whether alone or with PEG, highly improved the surface hydrophilicity as well as suspension stability of NPs. Their surface charge was greatly affected by the WSC coating, being close to neutrality for PEG/PDC NPs and highly negative in the case of PEG/CPCTS NPs. In comparison to NPs treated with PEG or WSC alone, the synergistic action of PEG and WSC strongly inhibited the macrophage uptake and extended the circulation half-life (t 1/2) with concomitant reduced liver sequestration. Particularly, PEG/PDC NPs showed the most striking result with regard to their performance in vitro and in vivo. Calculated t 1/2 of PEG/PDC NPs and PEG/CPCTS NPs was 63.5h and 7.1h, respectively, much longer than that of control PEG/PVA NPs (1.1h). More WSC materials need to be evaluated, but the present data suggest that, a combinatorial coating of PEG and PDC greatly prolongs the systemic circulation of NPs and represents a significant step in the development of long-circulating drug delivery carriers. [Copyright &y& Elsevier]

Abstract: In this paper, an array of highly ordered hydroxyapatite (HAP) nanotubes was synthesized by sol–gel auto-combustion method with porous anodic aluminum oxide (AAO) template for the first time. Based on thermogravimetry (DTA/TG), Fourier transform infrared (FTIR) and X-ray diffraction (XRD), the dried gel, derived from the sol solution with Ca(NO3)2·4H2O and PO(CH3O)3 as precursors and ethylene glycol as the polymeric matrix, exhibited a typical self-propagating combustion behavior at low temperature, directly resulting in hexagonal crystalline HAP materials. The resultant HAP arrays fabricated from the above sol–gel in the AAO template were uniformly distributed, highly ordered nanotubes with uniform length and diameter according to the observations of scanning electron microscopy (SEM) and transmission electron microscope (TEM). The electron diffraction (ED), XRD and X-ray photoelectron spectroscopy (XPS) survey proved the formation of HAP phase with polycrystalline structure in the AAO template. Based on these results, a potential mechanism of “an auto-combustion from dried gel to nanoparticles and a subsequent in situ reaction from nanoparticles to nanotubes” was proposed. [Copyright &y& Elsevier]

Abstract: A novel chitin-graft–polyleucine microsphere with hollow construction was prepared via ring-opening polymerization initiated with chitin based on interfacial protocol. The FT-IR and 1H NMR analysis demonstrated the conjugation with regulated graft length. The study provided a facile one-step route to obtain microsphere with glycoconjugation structure. This hybrid polysaccharide–polypeptide microsphere may give promising application in drug delivery and tissue engineering. [Copyright &y& Elsevier]

Abstract: Co-polypeptides containing 3,4-dihydroxyphenylalanine (DOPA) and l-lysine were synthesized to mimic the marine adhesive proteins through ring-opening polymerizations. The effects of composition, molecular weight, and curing agents on the adhesive properties, swelling, and degradation behavior of synthetic polypeptide were investigated. Ferric ion was introduced to the system to optimize both adhesive strength and water resistance, simulating the specificity of metal-mediated cross-linking of the marine mussel adhesives. The polypeptide was used to bond on porcine skin and porcine bone in vitro to evaluate the adhesive properties. Furthermore, outcomes of the cell culture of both co-polypeptide and co-polypeptide-modified ethylene vinyl acetate (EVA) demonstrated good cell affinity, which would provide basic data for the application of the co-polypeptide in the biomaterial field. [Copyright &y& Elsevier]

Abstract: The effect of oxygen gas on the chemical structure, surface property and controlled drug release characteristics of radio frequency (RF) plasma poly-n-butyl methacrylate (PPBMA) thin films was investigated. The ATR–FTIR and XPS spectra of the resultant PPBMA films showed relatively higher concentration of C–H, C–C and C but less intense peaks of Cx2013;O functionalities, which imply that the oxygen gas had no significant influence on the chemical structure of the plasma films. Results of the SEM experiment revealed that a dome-like structure was observed in the case of deposition without oxygen, but in the case of deposition with oxygen, a smooth and dense surface was produced. Moreover, the hydrophilicity of PPBMA obtained from the deposition with oxygen was higher than that without oxygen. Drug release from PPBMA deposition coating without oxygen had biphasic patterns, a fast release followed by a slow release, but the one with oxygen exhibited a slow Higuchi release. [Copyright &y& Elsevier]

Abstract: Laser post-treatment of Ni–Cu plasma-sprayed layer on copper substrate was conducted by pulsed Nd:YAG laser, and its sliding wear tests were investigated. Optical microscope (OM) and scanning electron microscope (SEM) observations showed that, after the laser post-treatment processing, the obtained Ni–Cu coating had dense and homogeneous structure, as well as metallurgical combination with copper substrate, without cracks found. High microhardness of 347 HV of Ni–Cu coating was obtained, which was almost 3.4 times of Cu substrate (102 HV). The volume loss of copper substrate was nearly 4 times of the laser post-treated sample, under sliding wear tests. With the laser post-treatment of large area crack-free Ni–Cu coating on copper substrate, the seizure tendency of Ni–Cu coating was much more suppressed, resulting in the improvement of wear properties. [Copyright &y& Elsevier]

Abstract: In this paper, the steady and dynamic rheological properties of concentrated aqueous injectable calcium phosphate cement (CPC) slurry were investigated. The results indicate that the concentrated aqueous injectable CPC showed both plastic and thixotropic behavior. As the setting process progressed, the yield stress of CPC slurry was raised, the area of the thixotropic hysteresis loop was enlarged, indicating that the strength of the net structure of the slurry had increased. The results of dynamic rheological behavior indicate that the slurry presented the structure similar to viscoelastic body and the property of shear thinning at the beginning. During the setting process, the slurry was transformed from a flocculent structure to a net structure, and the strength increased. Different factors had diverse effects on the rheological properties of the CPC slurry in the setting process, a reflection of the flowing properties (or injection), and the microstructure development of this concentrated suspension. Raising the powder-to-liquid ratio decreased the distance among the particles, increased the initial strength, and shortened the setting time. In addition, raising the temperature improved the initial strength, increased the order of reaction, and shortened the setting time, which was favorable to the setting process. The particle size of the raw material had much to do with the strength of original structure and setting time. The storage module G′ of CPC slurry during the setting process followed the rule of power law function G′=A exp(Bt), which could be applied to forecast the setting time, and the calculated results thereafter are in agreement with the experimental data. [Copyright &y& Elsevier]

Effects of the granularity of the raw materials on the hydration and hardening process of calcium phosphate cement (CPC) composed of equimolar tetracalcium phosphate (TECP) and dicalcium phosphate anhydrous (DCPA) were investigated systematically. The variation of pH value in CPC slurry indicated that the control step of CPC hydration was the dissolution of DCPA under these experimental conditions. Reducing the particle size of DCPA could accelerate the hydration rate, and decreasing the particle size of TECP would expedite the dissolution of DCPA, which would obviously result in a faster hydration rate. The results of isothermal conduction calorimetry showed that reducing the particle size of TECP could increase the conversion ratio of starting materials to hydration products, which would lead to an increase in the compressive strength of the hardened body of CPC. The sample composed of the smallest particle size of DCPA and TECP obtained the compressive strength of 41 MPa, which would not attain the highest compressive strength, 49 MPa. The smaller the particle size of either DCPA or TECP, the shorter the setting time was. During the setting process of CPC, the microstructure progresses from a gel structure to an agglomeration-crystallization structure. The calculated values of setting time from the rheological model coincided with the experimental data very well. The parameters of AC impedance spectroscopy were closely correlated with the mean pore diameter and porosity of the CPC hardened body. The results of AC impedance spectroscopy further verified that a small particle size of raw materials could result in high hydration rate and the compressive strength of 49.1 MPa. [Copyright &y& Elsevier]

The exothermal behavior in the hydration process of calcium phosphate cement (CPC) and their effect factors were investigated systematically. One CPC formulation is composed of tetracalcium phosphate (TECP) and dicalcium phosphate anhydrous (DCPA), and its hydration reaction is an exothermic reaction. Hydration includes five processes, namely, the start, induction, acceleration, deceleration and the terminating process. The introduction of hydroxyapatite (HAP) as crystal seed shortens induction and advances on the reaction peak position, which resulted from the introduction of crystal seed that reduced the activation energy of heterogeneous nucleation. The increase in temperature not only makes the reaction advance but also enlarges it. The activation energy of the hydration reaction is 176 kJ/mol by calculation. The particle size of the raw material and the ratio of calcium to phosphate in the specimen have large effects on the hydration process. Decrease in particle size of TECP and in the ratio of calcium to phosphate resulted in marked acceleration of reaction and made the reaction peak advance evidently, but the effect of particle size of DCPA is not so remarkable. Based on the heat liberation in the hydration of CPC specimens taking Ca/P as 1.5 and 1.67, the standard mole enthalpies of formation of TECP and calcium-deficient hydroxyapatite are −5908 and −11119 kJ mol−1, respectively. [Copyright &y& Elsevier]

The preparation of d- and l-myo-inositol 2,4,5-trisphosphate is described, together with the phosphorothioate counterparts. The known chiral diols d- and l-1,4-di-O-benzyl-5,6-bis-O-p-methoxybenzyl-myo-inositol were regioselectively protected at the 3-position using a benzyl group via a 2,3-O-stannylene acetal. Removal of the p-methoxybenzyl groups of each enantiomer gave d- and l-1,3,6-tri-O-benzyl-myo-inositol. Phosphitylation with bis(benzyloxy)diisoproplyaminophosphine and 1H-tetrazole gave the trisphosphite intermediate for each enantiomer. Oxidation with 3-chloroperoxybenzoic acid gave the fully protected d- and l-myo-inositol 2,4,5-trisphosphates. Sulphoxidation of the d- and l-2,4,5-trisphosphite intermediates gave the fully protected d- and l-myo-inositol 2,4,5-trisphosphorothioate compounds. The fully protected trisphosphates were deblocked using hydrogenolysis and the phosphorothioates were deprotected using sodium in liquid ammonia. The individual compounds were then purified using ion exchange chromatography to afford pure d- and l-myo-inositol 2,4,5-trisphosphates together with the corresponding phosphorothioates. [Copyright &y& Elsevier]

The impact of traumatic spinal cord injury (SCI) can be extremely devastating, as it often results in the disruption of neural tissues, impeding the regenerative capacity of the central nervous system. However, recent research has demonstrated that mesenchymal stem cells (MSCs) possess the capacity for multi-differentiation and have a proven track record of safety in clinical applications, thus rendering them effective in facilitating the repair of spinal cord injuries. It is urgent to develop an aligned scaffold that can effectively load MSCs for promoting cell aligned proliferation and differentiation. In this study, we prepared an aligned nanofiber scaffold using the porcine decellularized spinal cord matrix (DSC) to induce MSCs differentiation for spinal cord injury. The decellularization method removed 87% of the immune components while retaining crucial proteins in DSC. The electrospinning technique was employed to fabricate an aligned nanofiber scaffold possessing biocompatibility and a diameter of 720 nm. In in vitro and in vivo experiments, the aligned nanofiber scaffold induces the aligned growth of MSCs and promotes their differentiation into neurons, leading to tissue regeneration and nerve repair after spinal cord injury. The approach exhibits promising potential for the future development of nerve regeneration scaffolds for spinal cord injury treatment. [ABSTRACT FROM AUTHOR]

The application of organic coatings is the most cost-effective and common method for metallic equipment toward corrosion, whose anti-corrosion property needs to be improved and evaluated in a short time. To rapidly and rationally assess the anti-corrosion property of organic coatings in the ocean splash zone, a new accelerated test was proposed. In the study, the corrosion protection property of the coating samples was measured by an improved AC-DC-AC test in a simulated seawater of 3.5 wt.% NaCl solution, a simulated ocean splash zone test and a new accelerated test combining the above two tests. The results showed that the corrosion rate of the coating samples was high in the improved AC-DC-AC test, which lost its anti-corrosion property after 24 cycles equal to 96 h. The main rapid failure reason was that the time of the water and corrosive media arriving at the carbon steel substrate under the alternating cathodic and anodic polarization with symmetrical positive and negative electric charges was shortened. The entire impedance of the coating samples was improved by about 1.6 times more than that in the initial early time in the simulated ocean splash zone test, which was caused by the damage effect from the salt spraying, drying, humidifying, salt immersion, high temperature and UVA irradiation being weaker than the enhancement effect from the post-curing process by the UVA irradiation. In the new accelerated test, the samples lost their corrosion resistance after 12 cycles equal to 288 h with the fastest failure rate. On account of the coupling process of the salt spraying, drying, humidifying, salt immersion, high temperature combined with the cathodic and anodic polarization and the UVA irradiation, the penetration and transmission rate of water and corrosive media in the coating were further accelerated, the corrosion rate on the carbon steel substrate was reinforced even larger and the destruction of the top polymer molecules was more serious. The new accelerated test showed the strongest damage-acceleration effect than that in the other two tests. [ABSTRACT FROM AUTHOR]