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The molecular dynamics model of nano-machining a single-crystal silicon carbide substrate with a diamond abrasive is established. The effect of scratch on the atomic removal process and the material removal mechanism of the scratch wall were studied, considering vector displacement, cutting force, crystal structure transformation, and defects. The results show that the main methods for removing atoms in the scratched area are cutting and extrusion. The wall deformation of the scratch inlet zone invloves elastic and plastic mixed deformation, while the wall deformation of the scratch outlet zone is mainly plastic deformation. Increasing machining depth improves the removal of atoms. The presence of scratches on the substrate surface reduces both tangential and normal cutting forces in the nano-machining process, with the maximum difference being about 300 nN and 600 nN, respectively. The absence of atoms in the scratch area is the main reason for the decrease in tangential forces. The crystal structure of silicon carbide atoms is transformed by the shear and extrusion of the abrasive, resulting in a large number of atoms without a complete lattice. Moreover, atoms on the substrate surface form a stable structure by bonding with neighboring atoms. The affected area of substrate temperature is mainly concentrated under the abrasive and transferred to the depth of the substrate, with a difference of about 100 K between the substrate temperature at 2 Å, 5 Å, and 8 Å nano-machining depths.

In recent years, both morbidity and mortality of chronic kidney disease （CKD） have been rising rapidly and cardiovascular disease （CVD） is one of major causes. Traditional cardiovascular risk factors cannot fully explain this phenomenon. Therefore such CKD-specific risk factors as uremic toxins （UTs） have emerged as crucial players. This review focused upon typical protein-binding toxin of indoxyl sulfate （IS）. It described the mechanisms of effects in the occurrence and development of CKD and depicted an association with IS and CKD-related CVD by four aspects of atherosclerosis, arteriosclerosis, congestive heart failure and arrhythmias. Also effective therapeutic measures of reducing serum level of IS were introduced, including restriction of protein intake, modulation of intestinal flora, using oral intestinal adsorbents and innovative dialysis approaches of enhancing IS clearance. And albumin-binding competitors appear to be an effective removal of protein-binding UTs. In the future, more modes of IS clearance shall be discovered and verified whether or not they can slow the progression of CKD and lower the incidence of CKD-related cardiovascular disease in CKD.

The problem of food safety and public health caused by bacterial infection has always been a hot issue of social concern, so it is of great significance and application value to explore a safe and efficient food sterilization technology. X-ray irradiation, a new non-thermal sterilization technology with high penetrability that is safety controllable, has a high linear energy transfer (LET) value and relative biological effect (BRE). However, the mechanism for its inactivation effect on foodborne pathogenic bacteria such as Gram-negative bacteria is rarely reported, which greatly limits its application and development in the field of food microbial safety. In this study, the inactivation effect and mechanism of low-energy X-ray on Salmonella, a common foodborne Gram-negative pathogen, were investigated by transcriptomics in an effort to provide a theoretical basis for the application of low-energy X-ray in food safety control. The influence of X-ray irradiation at doses of 0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 kGy on the survival and sublethal effect of Salmonella was analyzed using plate counting method, the effect of X-ray irradiation on bacterial ultrastructure using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was examined, and the mechanism of Salmonella inactivation by low-energy X-ray was elucidated by transcriptomic analysis. Results showed that the sub-lethal rate of Salmonella was the highest (99.44%) when exposed to 0.5 kGy of X-rays. Low energy X-ray destroyed the bacterial cell wall and membrane. The transcriptome sequencing results showed that among the 292 differentially expressed genes (DEGs) identified, 214 were up-regulated and 78 were down-regulated. DEGs analysis showed that low energy X-ray irradiation could cause DNA damage and regulate oxidative stress response, amino acid synthesis, energy metabolism, virulence, and transmembrane transport in bacterial cells. These findings suggested that low-energy X-ray irradiation has the potential to inhibit bacterial growth and metabolism of cells and thereby reduce the risk of bacterial infection.

Background Aspartate aminotransferase (AST) /alanine aminotransferase (ALT) is a novel indicator to evaluate the prognosis of acute critical illness in recent years. At present, AST/ALT has only been reported to evaluate the prognosis of hemophagocytic lymphohistiocytosis (HLH) in adults, while HLH in children has not been studied. Objective To explore the relationship between AST/ALT and clinical characteristics and its prognostic significance in children with HLH, so as to provide a theoretical basis for early clinical recognition and diagnosis of HLH in children. Methods A total of 128 hospitalized children diagnosed with HLH in the Affiliated Hospital of Zunyi Medical University from January 2013 to May 2022 were selected as the research objects, and the baseline data of children were collected through the electronic medical record system. The children were divided into the T1 group (AST/ALT≤1.57, n=43), T2 group (1.57

Background In the field of assisted reproductive technology, medical cost of patients is increasingly considered as an important reference for making treatment protocols, while domestic health economics researches are rarely reported on the cost-effectiveness of gonadotropin-releasing hormone antagonist (GnRH-ant) protocol and short-acting GnRH agonist (GnRH-a) long protocol in fresh embryo transfer. Objective To analyse the cost-effectiveness of the clinical outcomes of GnRH-ant and GnRH-a protocols in fresh embryo transfer based on propensity score matching (PSM) . Methods A total of 1 971 patients treated with 2 117 cycles of in vitro fertilization/intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET) at the Reproductive Medicine and Genetics Center of the People's Hospital of Guangxi Zhuang Autonomous Region from 2016 to 2018 were selected and divided 422 patients with 432 cycles in the GnRH-ant group and 1 549 patients with 1 685 cycles in the GnRH-a group according to the protocols of controlled ovarian hyperstimulation (COH). Baseline data 〔including female age, type and duration of infertility, BMI, age at menarche, number of pregnancies, follicle stimulating hormone (FSH), basal estradiol (E2), basal luteinizing hormone (LH), basal progesterone, antral follicle count (AFC), etc.〕, therapeutic indicators 〔including COH protocols, gonadotropin (Gn) durarion, total Gn dosage, E2, LH, progesterone level and endometrial thickness on the trigger day, number of retrieved and mature oocytes, fertilization methods, number of transferable embryos, high-quality embryos and transferred embryos, etc.〕 and the clinical outcomes〔including unpregnancy, miscarriage, ectopic gestation, live birth (LB) 〕 were collected from the electronic medical record system and the 1∶1 PSM was performed using R 4.1.1 software with caliper value of 0.2. Cost-effectiveness analysis was performed on the two groups after PSM, sensitivity analysis was applied to verify the robustness of the study findings. Results There were significant differences in female age, BMI, basal FSH, LH, and AFC between the two groups before PSM (P0.05). Therapeutic indicators including Gn duration, Gn dosage, E2 and endometrial thickness on the trigger day, number of retrieved and mature oocytes were lower in the GnRH-ant group than GnRH-a group, while LH level on the trigger day was higher in the GnRH-ant than the GnRH-a group (P

To address issues like edge collapse and subsurface damage during the cutting process of SiC wafers, a model for cutting SiC wafers with ultra-thin diamond blades was established by combining Python language and Abaqus finite element analysis software. The effects of cutting parameters on cutting force, cutting temperature, wafer cutting edge morphology, cutting edge damage width and subsurface damage depth of wafer were studied. The results show that cutting force and cutting temperature are positively correlated with cutting depth, and there is an optimal value for the damage degree of the cutting edge and the subsurface damage depth. When the cutting depth is 6 μm, the cutting effect of SiC wafer is the best. The surface cutting edge damage width is 8 μm, the damage area is 4 905.56 μm2, the subsurface damage depth is 10.67 μm and the damage area is 7 022.18 μm2. In the high-speed cutting stage, where the cutting speed ranges from 60 to 121 m/s, cutting speed has no significant effect on cutting force, wafer temperature, wafer cutting edge morphology or subsurface damage.

The double-sided permanent magnet eddy current retarder, equipped with a set of magnets at a certain air gap on both sides of the conductor disk to make it rotate in the alternating magnetic field to generate the damping torque, has important applications in the field of high temperature gas cooled reactor control rod drop speed limit. The double-sided magnet structure can achieve greater magnetic flux, make the structure more compact, and balance the axial forces on both sides of the conductor disk. However, due to the influence of part machining accuracy and assembly deviation, it is difficult to accurately control the air gap width on both sides of the conductor disk to be equal. And for convenience, only one side of the air gap is usually adjusted when adjusting damping in engineering applications, which increases the asymmetry of the air gap width. For different requirements such as optimal torque or maximum critical speed, the conductor disk generally selects nonmagnetic materials with high conductivity or ferromagnetic materials with high permeability. In this paper, the influence of asymmetric air gap on the damping torque was studied. First, the main magnetic path of the eddy current retarder was analyzed, the two-dimensional magnetic equivalent circuit was established, and the influence of the asymmetry degree δ of the air gap on the main magnetic flux was qualitatively analyzed. Second, based on the three-dimensional finite element simulation, the magnetic field distribution, air gap magnetic induction intensity, damping torque, and axial force in the case of ferromagnetic and nonmagnetic conductor disks were compared. Finally, the experimental verification was carried out. The results show that, for the double-sided permanent magnet eddy current device, there are two main magnetic circuits, one is very sensitive to δ, while the other is almost insensitive to it. The sensitivity of the damping torque to δ can be reduced by adjusting the magnetic resistance of the magnetic circuit to increase the proportion of the insensitive main magnetic circuit flux in the total main magnetic flux. In the running state, the main magnetic circuit transfers when ferromagnetic and nonmagnetic conductor disks are used respectively. With the constant total air gap width, the damping torque and axial force are not sensitive to δ when the nonmagnetic conductor disk is used, but they show a significant sensitivity when the ferromagnetic conductor disk is used. For the permanent magnet eddy current device with a double-sided magnet structure, the nonmagnetic material conductor can reduce the sensitivity to the air gap deviation on both sides.

Objective To investigate whether BZLF1 and BILF1 can inhibit the expression of major histocompatibility complex(MHC)molecules in Raji cells during Epstein-Barr virus (EBV) lytic cycle. Methods Reactivation was triggered by treating Raji cells with TPA and NaB. As the marker protein during EBV lytic state, the BZLF1 protein expression was detected by Western blot. The expression of BZLF1 and BILF1 at transcription level was analyzed by RT-qPCR in EBV reactivation. The expression of MHC class Ⅱ and MHC class Ⅰ molecules was analyzed by flow cytometry. After BZLF1 and BILF1 over-expression or gene silencing via siRNA in Raji cells by electroporation, the expression of MHC class Ⅱ and MHC class Ⅰ molecules was detected by flow cytometry and Western blot respectively. Results EBV reactivation can be triggered with TPA and NaB. The BZLF1 and BILF1 gene expression was observed by inducing EBV reactivation in Raji cells. The levels of MHC class Ⅱ and MHC class Ⅰ molecules were down regulated by inducing EBV reactivation or ectopic expression of BZLF1 and BILF1 (P＜0.05). Expression of MHC class Ⅱ and MHC class Ⅰ molecules was restored by specific siRNA. Conclusions BZLF1 and BILF1 down regulate the expression of MHC class Ⅱ and MHC class Ⅰ molecules in EBV reactivation respectively.

[Introduction] To evaluate the anti magnetic interference ability of electrical and electronic devices, it is necessary to carry out the corresponding magnetic field immunity test, in which the high uniformity steady-state magnetic field generator is the core component of a steady-state test device. [Method] Taking the conventional Helmholtz and Maxwell square coil as the research object, the parameters were optimized through numerical calculation, and the coil structure that can produce high-performance magnetic field was obtained analytically. The finite element method was used to establish a model for calculation, and the correctness of the results was verified. [Result] The general calculation formula of coil parameters is obtained through numerical analysis, and the two coil types are compared. The optimized Maxwell square coil with small size and power consumption is selected as the final structure. [Conclusion] The research of this paper provides a detailed calculation process and design reference for the high uniformity steady-state magnetic field generator, and can provide a theoretical basis for the design of corresponding equipment in the electrical industry.

The rare earth conversion film has attracted more and more attention in recent years because of its good corrosion resistance and non - toxicity. The concept and film forming mechanism of rare earth conversion film were briefly introduced, and the application of rare earth in corrosion prevention for ferrous metals as well as the nonferrous metals of aluminum, magnesium, zinc and their alloys was summarized. This study found that the corrosion resistance of composite rare earth conversion film was better than that of the single rare earth conversion film. Moreover, it also explained the reason why cerium conversion film had better corrosion resistance than other rare earth conversion films. Finally, it pointed out that the composite rare earth conversion film, rare earth composite alloy coating and densification of rare earth conversion film would be the development direction.

Accurate measurement of soil moisture is crucial in agricultural water management. A mini inside-out nuclear magnetic resonance (NMR) sensor has been designed to measure the moisture in model soils, consisting of three cylindrical magnets magnetized in the axial direction and four arc spiral coils with the same size in series. A circumferential symmetric constant gradient field can be obtained by adjusting the radius and height between the cylinders. To improve the signal-to-noise ratio of the sensor, this a wide-band matching method was proposed in this work to expand the excitation region of the radio frequency coils. The Carr-Purcell-Meiboom-Gill (CPMG) signal was analyzed through inverse Laplace transformation. With the results obtained, moisture content of the sample was found to be positively correlated with the integral area of T2 spectrum peak, verifying the feasibility of the sensor in soil moisture measurement.

饮食中的饱和脂肪酸通常与人体健康的负面影响相关，然而有关各种饱和脂肪酸的生理效应、生物功能等研究结果存在一定的争议。综述了饱和脂肪酸的可能抗癌作用及作用机制，以期为癌症的辅助治疗提供一定的参考。目前对短链饱和脂肪酸、中链饱和脂肪酸、奇数链饱和脂肪酸、支链饱和脂肪酸抗癌作用的报道较多，饱和脂肪酸主要通过阻滞细胞周期、诱导细胞凋亡、抑制细胞迁移和调控细胞生长相关的信号通路，或通过影响相关基因的表达和转录因子的磷酸化水平来发挥抗癌作用 Dietary saturated fatty acids (SFAs) is usually associated with negative consequences for human health. However, there are some contradictory experimental results on the physiological effects and biological functions of various SFAs. The anti-cancer effects and mechanisms of SFAs were mainly summarized and discussed, so as to provide the way for adjuvant therapy of cancer. At present, there are many reports on the anti-cancer effects of short-chain SFAs, medium-chain SFAs, odd-chain SFAs and branched-chain SFAs, SFAs exert anti-cancer effects mainly by blocking the cell cycle, inducing apoptosis, inhibiting cell migration and regulating cell growth-related signalling pathways, and affecting the expression of related genes and the phosphorylation levels of transcription factors.

BACKGROUND The zircon U-Pb dating and analysis of major, trace and rare earth elements of rocks are the main research methods used to study the genesis of intrusive rocks. OBJECTIVES To constrain the genesis of neoproterozoic gneissic moyite of the Yangsanzhai, Xiaotian volcanic basin. METHODS Chemical composition of rocks was analyzed by X-ray fluorescence spectrometry (XRF), inductively coupled plasma-mass spectrometry (ICP-MS), and the zircon U-Pb age was determined by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS). RESULTS Results show that the rock was characterized by high silicon, kalium and sodium, and low iron, magnesium, calcium and phosphorus. The content of SiO2, Al2O3, MgO, K2O and Na2O were 65.86%-78.29%, 10.89%-16.02%, 0.17%-1.17%, 1.37%-6.44% and 0.53%-6.50%, respectively. The rock belonged to the high potassic calc-alkaline series. The samples were characterized by depletion of Nb, Sr, P and Ti, and enrichment of La, Ce, Nd and Zr. The samples had high content of rare earth elements (ΣREE=152.70-650.88μg/g) with light rare earth enrichment (LREE/HREE=6.77-20.64). Most of the samples had weakly negative europium anomalies (δEu=0.29-1.15) without cerium anomaly. The normalized curve of rare earth elements was characterized by right-incline. The 206Pb/238U ages of the 30 zircon points ranged from 720 to 828Ma, with a weighted average age of 776±11Ma (MSWD=2.1). CONCLUSIONS The discovery of Neoproterozoic gneissic moyite in the Xiaotian Basin indicates that there is uplift in the center of this basin, not the 'bucket' shape of thick in the middle and thin at the sides, as previously recognized. This has important guiding significance for the understanding of the tectonic morphology of the basin and further prospecting.

BACKGROUND Iron is the most abundant element on earth with variable valences. It is widely distributed in various minerals, rocks, fluids and organisms, and is involved in diagenesis, mineralization, hydrothermal activities and life activities. The study of iron isotope composition provides important information for geochemistry, astrochemistry and biochemistry. The accurate measurement of Fe isotopes is an important basis for the development of related research. OBJECTIVES To summarize the research progress of Fe isotope measurement technology. METHODS The current chemical separation and purification methods and main instrumental analysis techniques commonly used for iron isotopes, were compared and analyzed in this review, and the mechanism of different types of fractionations during mass spectrometry were discussed. These advances included:(1) Improvement of anion resin during determination of iron isotope by solution method; (2) Mass spectrometry development from traditional thermal ionization mass spectrometry to multi-collector inductively coupled plasma mass spectrometry; (3) Development of laser in situ analytical technology. On this basis, the steps and calibration methods that would cause iron isotope fractionation during the analysis were summarized, and the advantages and disadvantages of different analytical methods were reviewed. RESULTS The analysis process of solution method was long and complicated, but the precision was high (0.03‰, 2SD) and the method was stable. In situ iron isotope analysis method developed from nanosecond laser denudation to femtosecond laser denudation, with shorter pulse duration, higher pulse peak intensity (up to 1012W), and focusing intensity exceeding 1020W/cm2. In situ iron isotope analysis method was fast and had high spatial resolution, which can be used to discuss the geochemical process from the microscopic perspective. However, the presence of matrix effects limited the widespread use of iron isotopes. CONCLUSIONS Shortening solution analysis process and developing a series of matrix-matched standard samples are the research direction of iron isotope analysis.

BACKGROUND The conventional method for the measurement of sulfur isotopes in sulfate includes mainly barite conversion coupled with dual-inlet SO2 methods. These methods are facile and reliable. However, the large amounts of samples, the length of time needed, the laborious experimental work, and complicated preprocessing are impractical for the development direction of micro-analysis. OBJECTIVES To develop a method for determination of sulfur isotope compositions in gypsum directly through continuous flow elemental analyzer-isotope mass spectrometry (EA-IRMS). METHODS Two different preparation methods were used. (1) Direct measurement of sulfur isotopes was carried out by mixing calcium sulfate powder with V2O5 in a tin cup using EA-IRMS. (2) Calcium sulfate was fully dissolved in deionized water. The precipitation reagent BaCl2 was added to the liquid in which the calcium sulfate sample was dissolved. After the precipitated barium sulfate was filtered out, it was washed 2 to 3 times with deionized water. Samples were dried and mixed with V2O5 in a sealed tin cup and then determined by mass spectrometry. RESULTS The δ34S values of 13 gypsum samples ranged from -20‰ to -30‰, and the results from replicate measurements were compared for these two methods, yielding the absolute difference in δ values were 0.0-0.2 permil, indicating that the sulfur isotope ratios of the same sample were basically identical. CONCLUSIONS Compared with the conventional analysis method, the application of 'no pretreatment' to analyze the sulfur isotopes of gypsum was conducted successfully. Adding V2O5 to samples directly, during the process of instantaneous combustion, the oxygen in calcium sulfate are substituted by the external oxygen in V2O5 and oxygen gas, and the obtained oxygen of SO2 gas is uniform. Therefore, sulfur isotope ratios of SO2 can completely represent those of the calcium sulfate, making it unnecessary for oxygen isotope correction. The direct online analysis of sulfur isotopes in calcium sulfate samples using EA-IRMS is verified to be feasible.

AIM: To investigate the effect of melatonin (MEL) on the depression behavior in mice induced by chronic restraint stress (CRS). METHODS: Forty-eight SPF-grade male C57BL/6J mice were randomly divided into control group (;i=12) and CRS group (n-36). The mice in CRS group were further divided into 3 groups (n-12) : CRS+vehicle group, CRS+fluoxetine (FLX) group, and CRS+MEL group. Mouse depression model was established by the CRS method for 14 d, and then the depression-like behaviors were observed for modeling validation. After 14 d of drug intervention combined with CRS, the behaviors were detected again. Nissl staining, RT-qPCR, Western blot and immunofluorescence staining were performed in mouse brain tissues. RESULTS: Compared with control group, the weight changes of the mice in CRS group were significantly lowered, the immobility time of forced swimming and tail suspension tests was significantly increased, the consumption rate of sugar water decreased significantly, and the central time and movement distance in open-field test decreased significantly (P<0.01). Compared with CRS+vehicle group, the depression-like behaviors induced by CRS were successfully reversed by the drugs in both CRS+FLX and CRS+MEL groups. Furthermore, compared with CRS+vehicle group, the mRNA levels of brain-derived neurotrophic factor (BDNF), extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB), and the protein levels of BDNF, phosphorylated ERK1/2 and CREB were increased significantly in both CRS+FLX and CRS+MEL groups (P«X 01). The results of Nissl staining showed that the neurons in CRS+vehicle group were irregularly arranged, and the number of Nissl bodies was decreased (P<0. 01). The neuron status and number of Nissl bodies in both CRS+FLX and CRS+MEL groups were significantly improved (P<0. 01). Immunofluorescence staining showed that the number of c-Fos-positive cells in the frontal cortex and hippocampal CA1 region of the mice in CRS+vehicle group was significantly larger than that in control group (P< 0.01). Conversely, the number of c-Fos-positive cells in CRS+FLX and CRS+MEL groups was significantly smaller than that in CRS+vehicle group (P<0. 01). CONCLUSION: Melatonin can significantly alleviate depression-like behavior induced by CRS in mice, which may be related to the activation of BDNF-ERK-CREB signaling pathway. [ABSTRACT FROM AUTHOR]

When the planetary gear transmission system fails， its signal transmission is coupled with each other， and the nonlinear characteristic is presented， which makes the fault type and damage degree of the planetary gear to be difficultly recognized. The optimization mathematical model of the kernel function scale parameter is constructed by means of Fisher criterion（FC） discriminate function in pattern recognition， and the improved particle swarm optimization method is applied to the optimization to fully improve the analysis performance of the kernel principal component analysis（KPCA） for nonlinear problem. It is applied to the identification and diagnosis of wear damage degree of planetary gear. The results of example analysis show that the intelligently optimized KPCA based on PSO-FC have improve the structure distribution of data in the feature space and achieved the good scale clustering effect in planetary gear wear damage degree recognition. It can effectively solve the identify problems of complex fuzzy damage boundary and damage degree in the mechanical transmission.

With the expansion of high dimensional space in UAV trajectory planning, the flying environment of UAV is very complex, and the external threat of UAV is no longer a simple two-dimensional static threat. The traditional ant colony algorithm and artificial potential field algorithm cannot meet the requirements of real-time and high complex environment. To solve the above problems, a new dynamic programming algorithm based on dynamic weighted A* algorithm is proposed. Firstly, the flight environment of UAV is modeled. By studying the constraints such as the turning radius, the length of track section and the limit of the maximum range, the safe flight of UAV is ensured, thus reducing the crash rate and the threat probability. Secondly, a new navigation mode is designed by studying the track and external threat parameters of the UAV, which can reduce the danger of navigation and reduce the loss. Then, the potential energy of the vertex can be expanded. The dynamic weight of the overall change of location and grid graph is obtained, and the cost function in dynamic environment is obtained, which increases the speed, accuracy and evasion degree of obstacle avoidance search. Finally, the simulation results show that under the same application environment, the proposed algorithm has the best path, the least threat cost and the shortest execution time compared with the ant colony algorithm and artificial potential field algorithm. To sum up, the dynamic weighted A* algorithm can be well applied to UAV trajectory planning, reducing the cost of UAV track, shortening the completion time of the algorithm and improving the search speed and precision of unmanned aerial vehicle trajectory planning in complex environment.

Due to the influence of the process, actual frequency of clock generator module always has some deviations from target, it is necessary to trim the clock module whose frequency is not as it was expected. Compared with traversing method, dichotomy has higher convergence rate. Auto trim circuit was designed based on dichotomy, and measurement error caused by synchronous of referenced pulse was analyzed. Auto trim circuit counted output of clock generator module during high level of referenced slow pulse which was generated by automatic test equipment, and trim value was changed using dichotomy, achieving the purpose of saving measure time.

As an important mode in airborne radar systems, Wide Area Surveillance Ground Moving Target Indication (WAS-GMTI) mode has the ability of monitoring a large area in a short time, and then the detected moving targets can be located quickly. However, in real environment, many factors introduce considerable errors into the location of moving targets. In this paper, a fast location method based on the characteristics of the moving targets in WAS-GMTI mode is utilized. And in order to improve the location performance, those factors that introduce location errors are analyzed and moving targets are relocated. Finally, the analysis of those factors is proved to be reasonable by simulation and real data experiments.

Apatite is a common accessory mineral, having a high Sr-Nd content and a low Rb content. The precise determination of micro-area Sr-Nd isotopic composition for apatite will provide important geochemical information for discussing the details of the geological process. Laser Ablation Multi-collector Inductively Coupled Plasma-Mass Spectrometry (LA-MC-ICPMS) technique has the characteristics of rapid analysis, high analytical precision and high spatial resolution, and is particularly suitable for Sr-Nd isotopic analysis of a large quantity of fine-grained apatite samples. The precise deduction of isotopic interference and calibration of instrument mass bias are crucial for in-situ analysis to obtain Sr-Nd isotopic ratio. In this article a method is described, which adopts LA-MC-ICPMS and combines with the newly published method for deduction of interferences, like Kr, Rb, divalent ions of REEs and calcium-containing polymer for Sr isotopes, Sm for Nd isotopes. The calibration of instrument mass bias is carried out, and the in-situ Sr-Nd isotopic analysis approach for apatite is established. The test results of Durango apatite standard, Apatite 1 and PE show that Sr-Nd isotopic composition of apatite sample with high Sr-Nd content can be accurately determined. The specific results are consistent with literature or the measured values by Thermal Ionization Mass Spectrometry (TIMS) within error. The measurement precision of Sr isotopes is < 0.015% (2SD), and that of Nd isotopes is < 0.005% (2SD). The established method is applied for Sr-Nd isotopic analysis of Durango apatite standard, Apatite 1 and PE (laboratory standard), respectively. The analysis results indicate that the Sr-Nd isotopic compositions of the three apatite samples are basically consistent, and can serve as ideal reference samples for in-situ Sr-Nd isotopic analysis.

In the paper, a method of moving target detection and parameters estimation is proposed used for dual channels Wide Area Surveillance (WAS) radar based on high resolution Doppler Beam Sharpen (DBS) image. First, it analyzes characteristics of clutter and moving target return, and presents the ways of clutter suppression and moving target parameters estimation. Then, an approach to decrease errors of parameters estimation is proposed. At last, an effective approach to resolve the ambiguity caused during estimating moving targets parameters is proposed. The effectiveness of the presented method is demonstrated by both simulated data and real data.

Compressed Sensing (CS) theory provides a new solution for lowering acquisition cost and synchronous demodulation processing pressure of DS TT&C signal, furthermore sparsity is an important prerequisite for CS application, but the research on sparsity of the signal is seldom reported. In this paper, the sparsity of DS TT&C signal is in depth analyzed by building the basic dictionary, and a dual-stage dictionary learning method is proposed, moreover the basic learned dictionary and delay-Doppler dictionary are built based on the dual-stage dictionary learning method and detailed analysis of the signal model. Lastly, the performances of the basic dictionaries are verified by simulation experiments. The results show that DS TT&C signals receive a strong sparsity both in the built basic dictionaries, which provides a foundation for signal processing on the basis of CS. [ABSTRACT FROM AUTHOR]

Objective To prepare chitosan microparticles based on influenza vaccine liposome, and determine the preparation technology of chitosan liposome vaccine. Methods We prepared chitosan microparticles with different N/P ratio based on influenza vaccine liposomes which were produced by film dispersion method. Then we observed the morphology and determined the average particle size and particle size distribution, entrapment efficiency and the binding rate. By comparing the encapsulation rate and binding rate of different N/P ratio chitosan nanoparticles, the preparation technology of chitosan liposome vaccine was preliminary determined. Results Influenza vaccine liposomes coated with chitosan were round or oval with uniformed particle size distribution. The average particle size increased from 2.14 μ m to 4.05 μ m, and the average encapsulation rate increased from 80.41% to 84.37% after coated liposomes with chitosan . By comparing 6 N/P ratio, the ration of 5:1 was the best ratio in terms of binding rate which was 19.40% . Conclusions Chitosan coated liposomes is circular with increased particle size and encapsulation rate. 5:1 ratio of N/P is the optimum proportion concerning the incubation of chitosan and liposome. [ABSTRACT FROM AUTHOR]

Objective To study the dynamic changes of thioredoxin 2 (Trx2) protein expression in the cardiac mitochondria of selenium deficiency rats and its effect on cardiac mitochondria damage. Methods Thrity-six rats were randomized into normal control group (n = 18) and selenium deficiency model group (n = 18) . When rats were fed for 20 weeks, 30 weeks and 40 weeks, respectively, their cardiac function was determined by carotid artery intubation. At the corresponding time points, damage of cardiac mitochondria was observed under electron microscope; the mitochondrial stereological parameters including surface density (Sv), volume density (Vv) and specífic surface (Rsv, surface-to-volume ratio) were further studied. The cardiac mitochondria were extracted from the rats at the corresponding time points to assess the enzyme activities of succinate dehydrogenase (SDH) and cytochrome C oxidase (COX), and to detect the protein expression of Trx2 with Wettern blot. Results ① Rats in the model group had notably decreased cardiac function, and electron microscopy showed mitochondrial swelling with fractured or dissolved crsitae. Further study showed notable decreases in Sv, Rsv, SDH and COX, but remarkable increase in Vv in the selenium deficiency rat hearts compared with that in the corresponding control group (P<0.05) . With the time extension of low-selenium feeding, Sv, Rsv, SDH and COX all decreased, and Vv significantly increased (P<0. 05). ② The protein expression of Trx2 in the cardiac mitochondria of selenium deficiency rats significantly decreased compared with that in the corresponding control group, and the decrease was greater as the time of seienmm deficiency prolonged (P<0.05). ③ Pearson linear correlation analysis showed that the protein expression of mitochondrial Trx2 had a positive correlation with Sv, Rsv, SDH and COX, but a negative correlation with Vv (P <0 .01). Conclusion Selenium deficiency down-regulates the protein expression of mitochondrial Trx2 in the rat heart, which results in cardiac mitochondrial injury and the uiimate progress of heart failure. [ABSTRACT FROM AUTHOR]

To overcome the shortcomings of the traditional artificial potential field method in mobile robot path planning, an improved method was proposed, in which potential field intensity was used instead of force vector to plan the path for the mobile robot. By addition of coefficient item to repulsion potential field of obstacles, the destination unreachable problem caused by the closely distance between destination and obstacles was solved. Considering the speed-effect of mobile obstacles and mobile robot, the velocity information was introduced into potential field function and an "added potential field" was also introduced to guide the robot to be out of local minimum points. Based on the new method, all the potential field intensity was added by algebraic sum style, then the genetic trust region algorithm was used to search the minimum sum point of potential field intensity within the movement scope which the robot can arrive at during a sampling period, and the global optimization path was composed of all the minimum points. Experiment results show that better path planning for mobile robot in dynamic environment can be achieved by this new method. [ABSTRACT FROM AUTHOR]

For describing the topology information in the reconfiguration process of self-reconfigurable robot, an UBot self-reconfigurable robot topology description method based on incidence matrix is proposed. At first, a joint state table during the reconfiguration process is built up based on the analysis of the module motion characteristic of UBot self-reconfigurable robot system; and then a binary number representation is developed by analyzing the linkage and position relation that may exist among modules; finally, taking worm configuration as example, the corresponding topology description matrix is obtained, which can describe not only the information of module address, module connection status and position relation, but also the joint angle status information of each module exactly. This topology description method is helpful to the research of configuration matching and reconfiguration algorithm of reconfigurable robot. [ABSTRACT FROM AUTHOR]

To realize the stable walking cycle of passive biped robot, this paper presents a method to find the fixed point and a detailed analysis on the effect of the change of mechanical parameters of the passive walking model and slope gradient on the existence of stable fixed point is' carried out. The effect for each parameter at the given initial conditions on the speed of converging to the stable cycle walking and the effect of changing status of stable fixed point from the change of the parameters are investigated. It is concluded that the smaller mass for legs, a higher location for the center of mass, the right radius of foot, the larger moment of inertia as well as the right slope gradient are beneficial for improving the local stability of the passive robot. [ABSTRACT FROM AUTHOR]

In order to get a better convergence anti transition for passive bipedal robot research, this article analyzed the initial model of passive biped robot, i.e. the two-dimensional rimless-wheel model. Its dynamic model was constructed and its motion characteristic was analyzed with Adams. The effect of initial velocity, quality, foot radius, the number of spokes, the length of spoke, moment of inertia and slope gradient on the movement of rimless-wheel was analyzed. Results show that a right initial velocity and slope gradient, larger quality and foot radius, more and shorter spokes, as well as larger moment of inertia can lead to a fast and smooth cycle motion for rimless-wheel. [ABSTRACT FROM AUTHOR]

A transparency oriented self-adaptive algorithm applied to admittance type haptic devices is proposed, which is based on an inner velocity loop PI controller with desire force feed-forward. Besides, an online iterative approach is presented to estimate the stiffness parameter of the controller. The systemic stability proof of the algorithm is realized by constructing Liapunov stability criterion with system states. The comparative experimental results show that the new method can accommodate the contact stiffness variation and effectively improve the transparency of haptic system. [ABSTRACT FROM AUTHOR]

A physical model of femur, with rounded and individual feature, was constructed by means of disposing computer tomography (CT) images from a volunteer's human femur. And then, some parameters were derived from CT images for the geometrical and material properties of the moulded femur, and the vibration modal analysis of femur was carried out through the finite element method. The former six-step modes were extracted out. This study is useful for developing artificial joint design available for Chinese bony features. [ABSTRACT FROM AUTHOR]

Objectives: To analyze the Nogo-P3 component of event-related potential (ERP) in the process of visual acuity processing, to provide electrophysiological evidence for objective evaluation of visual acuity., Methods: Twenty-six subjects with no other ocular diseases except for ametropia were recruited, and all subjects had uncorrected visual acuity both eyes 1/10 (evaluated using Monoyer chart). Block letter E with different visual angles and directions were used as graphic stimuli. The Go/Nogo paradigm was used for ERP studies. The visual angle of Go stimulation angle was 1°15', Nogo stimuli were 1°15', 55', 24' and 15'. The visual acuity test was performed on each of the two naked eyes separately in all subjects, and the characteristics of the Nogo-P3 component were analyzed., Results: The latency of Nogo-P3 showed no difference between the stimuli of 1°15' and 55', and between Nogo stimulation angle 24' and 15'. There was significant difference between Nogo stimulation angle 1°15' and 24', and between Nogo stimulation angle 1°15' and 15' ( P <0.05). There was significant difference between Nogo stimulation angle 55' and 24', and between Nogo stimulation angle 55' and 15' ( P <0.05). No significant differences were observed in the Nogo-P3 amplitude among Nogo stimulation., Conclusions: In the Go/Nogo paradigm, Nogo-P3 can reflect the cognitive response of subjects to Nogo stimulation, which can be used for objective evaluation of visual acuity.

In order to understand the possibility and spatial pattern of Benggang (collapsing hill) erosion in risk assessment and distinguish the primary and secondary areas in Benggang prevention, we took a small watershed in Anxi County (Fujian, China) as the study area and Benggang as the source, and constructed the Benggang expansion resistance surface using the minimum cumulative resistance (MCR) model and divided the risk zoning. The results showed that the area around Benggang displayed a low resistance value, while the northwest and southeast areas displayed a high resistance value. The Benggang expansion resistance surface had an island type form. Based on resistance surface, the research region was divided into very high-risk, high-risk, medium risk, low-risk and very low-risk zones. We proposed corresponding Benggang management suggestions for those zones. A total of 21 strategic saddle points were extracted based on the resistance surface morphology. The strategic points in the lower safety zone were considered as the priority areas for Benggang prevention. We compared the hazard results based on the MCR model and the information quantity method. These results were consistent in spatial distribution, indicating the reliability of the results of hazard zoning by the MCR model.

Objectives: To explore the relationship between the frequency characteristics and response threshold of auditory steady-state response (ASSR), auditory brainstem response (ABR) and 40 Hz auditory event related potential (40 Hz AERP), and their application values in forensic medicine., Methods: Thirty volunteers with normal hearing (60 ears) were selected to perform pure tone audiometry (PTA) threshold and ASSR, ABR and 40 Hz AERP response threshold tests in the standard sound insulation shielding room, and the results were statistically analyzed by SPSS 22.0 software., Results: At 0.5 kHz and 1.0 kHz frequencies, the correlation between 40 Hz AERP response threshold and PTA threshold was good, which was better than that of ASSR and ABR response threshold. At 2.0 kHz and 4.0 kHz frequencies, the correlation between ASSR and ABR response thresholds and PTA threshold was good, which was better than that of 40 Hz AERP response threshold., Conclusions: To evaluate the hearing at 0.5 kHz and 1.0 kHz frequencies, it is recommended to use 40 Hz AERP and ASSR to comprehensively assess the PTA threshold of the subjects. To evaluate the hearing at 2.0 kHz and 4.0 kHz frequencies, ABR and ASSR are recommended to assess the PTA threshold of subjects comprehensively. The combination of ASSR, ABR and 40 Hz AERP can improve the accuracy of hearing function evaluation.

The changes of active ingredients content, moisture status and texture characteristics during the moistening of Paeoniae Radix Alba were studied by low-field NMR and imaging(LF-NMR/MRI) and texture analyzer, so as to analyze the correlation between LF-NMR parameters, texture characteristics and active ingredient content of Paeoniae Radix Alba during the moistening at diffe-rent times. The results showed that MRI technology could directly, vividly and accurately characterize the degree of moistening and the process of water migration, and the degree of moistening was consistent with the judgment results of traditional experience. The characteristics of moisture migration and moisture phase state in the moistening process of Paeoniae Radix Alba were that the total water content increased and existed in the form of free water, with an increased moisture mobility. In the case of dampening, the total water content did not increase, but the more watery part of the medicinal material was distributed to the less watery part, with a reduced fluidity. Finally, the medicinal materials were moistened, which can be mutually verified with the MRI results. The free water content and the total water content of Paeoniae Radix Alba had extremely negative correlations with hardness, surface toughness, internal toughness, Paeoniflorin and albiflorin contents(P&lt;0.01). It showed that the use of LF-NMR/MRI and texture analyzer could better characterize the moistening process. It provides data characterization for the scientific connotation of &quot;less soaking and more moisturizing, and the drug is completely saturated with water&quot;, and the traditional experience of &quot;observing the water head&quot;. The feasible and objective evaluation method was helpful to optimize the softening process parameters, scientifically standardize the operating specifications, define the scienti-fic connotation of traditional Chinese medicine softening, and promote the inheritance and innovation of traditional Chinese medicine processing.

To conduct endpoint determination of tablet coating and analyze coating process by near-infrared spectroscopy(NIRS). Firstly, the layered k-fold cross validation was used to discuss the optimal combination of spectral interval and preprocessing method, and the optimal result was used as the modeling condition. Secondly, in above condition, the qualitative model was proposed based on the throught of principal component analysis(PCA) and confidence interval, this model and the conformity test model were established respectively in this study, and the discrimination performance of coating eligibility was calculated. Then, the internal cross validation was used to obtain the coating end-point conforming rate as the threshold for determining the endpoint of tablet coating. Finally, the results of predicted conforming rate and discrimination parameters for the test samples of different batches were calculated with the above models, which were then further used for end-point detection and process analysis. As compared with the conformity test, this method proposed in this study was more accurate and stable in determining the coating conformity, and the coating endpoint can be accurately determined when 95% of the eligibility rate was used as the discriminant threshold. Meanwhile, in the process analysis, the change trend of the process parameters(model discrimination parameters, prediction conforming rate) was basically consistent with that in the conformity test. The results indicate that the method proposed in this study has a good and stable performance, which can be used to determine the endpoint of coating and analyze the process. It is of great significance to reduce the difference between batches and improve the product consistency. Meanwhile, this research method also lays a foundation for the future researches by online near infrared measurements.

In 2015, continuous volatile organic compound (VOC) monitoring was conducted for Dongsi (urban site), the southeast boundary site Yongledian, and Dingling (background site). The average annual mole fraction of atmospheric VOCs in urban areas was(48.93±31.03)×10 -9 , the average annual mole fraction of the southeast boundary was (54.55±39.64)×10 -9 , and the average annual mole fraction for the background site was(28.25±21.26)×10 -9 . Considering VOC components, alkanes occupy the highest proportion, followed by oxygen-containing VOCs, olefins, aromatic hydrocarbons, halogenated hydrocarbons, and acetylene. VOC concentration was higher in winter, lower in summer, higher at night and lower in the daytime. The concentration of acetylene in urban areas was higher in spring, summer and autumn, but higher in winter at the southeast boundary site. However, in the background, a small amount of direct anthropogenic interference was detectable, with the concentration of oxygen VOCs higher at noon and in summer. The species with high mole fractions in the VOCs were identified as mainly ethane, acetylene, ethylene, acetaldehyde, propane, acetone, n-butane, dichloromethane, and other low-carbon substances. The concentrations of benzene and toluene in the high-carbon group was relatively high. From the toluene/benzene ratio, it was found that Beijing VOCs were influenced by many sources other than transportation. However, the ratio of ethane/acetylene has been found to be significantly dependent on the aging of air mass in Beijing, with the southeast boundary particularly affected by movement of the aging air mass. Changes in the ratio of isopentane/TVOC showed that high summer temperature enhanced gasoline volatilization. The southeastern boundary point of OFP was the highest, followed by the urban area, with Dingling lower. The species with greater contribution to OFP were ethylene, propylene, acetaldehyde, paraxylene and toluene, with the higher mole fraction of alkanes making little contribution to OFP.

Mitochondria are an essential component of multicellular life and play important roles in the health of the cells and the body. Mitochondria can produce energy by oxidative phosphorylation, mediate calcium and reactive oxygen signal transduction, and regulate cell apoptosis. Recent studies indicate that mitochondria continually change their shapes and distribution by fission and fusion, which are collectively termed mitochondrial dynamics. Mitochondrial dynamics play critical roles in maintaining mitochondrial function. This review focuses on the structure and biological functions of mitochondrial fission and fusion related proteins in mammal cells.

Hispidulin(HPDL) chitosan microspheres were prepared in this study to deliver HPDL to the lesion sitevia intravenous injection, and further evaluate their anticancer effects in vitro and the growth inhibition effect on A549 cells spheroids. HPDL chitosan microspheres were prepared by emulsion crosslinking method with chitosan as a drug carrier and the amount of HPDL was determined by high performance liquid chromatography (HPLC). The morphology of microspheres was observed under laser scanning confocal microscope. Additionally, the drug release amount of targeting microspheres was detected by dialysis method. Furthermore, the anti-proliferative effects against A549 lung cancer cells were tested by sulforhodamine B (SRB) method, and the effects of HPDL chitosan micrpsphereson early apoptosis of A549 cellswere determined by flow cytometry. A549 cells tumor spheroids were developed in vitro and then HPDL chitosan microspheres were added. On the 0, 1, 3, 7 d after adding the drugs, the inverted microscope was used to observe the mythologicaland volume changes of A549 cells spheroids. The encapsulation efficiency of HPDL chitosan microspheres was （75.32±0.52）%, and the drug loading amount was （7.76±0.67）%. Meanwhile, the microspheres were round shaped andhad smooth surface. The HPDL chitosan microspheres exhibited stronger inhibitory effects on A549 lung cancer cells. The results of flow cytometry indicated that, the early apoptosis rate of lung cancer A549 cells was （37.0±0.75）% at 24 h cells culture after drug administration. The volume of tumor spheroid was significantly inhibited, which had been shrunk by (50.09±11.06)% after the treatment by drug-loaded microsphere at day 7 as compared with blank group; meanwhile, the cells surface were obviously lysed. The preparation method in this research was simple and practicable, and the microspheres prepared with this method were round and smooth, with high encapsulation efficiency, which can significantly inhibit proliferation of lung adenocarcinoma A549 cells and induce cell apoptosis, and at the same time can cause lysisand death of A549 cell tumor spheroid., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To understand the risk situation of imported schistosomiasis and its main influencing factors in Shanghai City from 2005 to 2015., Methods: A retrospective survey was performed, and the database was established based on the data collection of imported schistosomiasis, Oncomelania hupensis snail situation and mobile population in Shanghai City from 2005 to 2015., Results: From 2005 to 2015, the mobile population in Shanghai City increased by 123.92%, which reached about 9 816 500, and 54.70% of them were located in the inner suburban districts. The accumulated areas with snails of 7.13 hm 2 were found in 16 towns of 4 outer suburbs (excluding Chongming District). A total of 23 cases of imported schistosomiasis were found in Shanghai City, and the number of the imported schistosomiasis cases was on the downward trend ( rs = -0.782, P = 0.004). From 2005 to 2009, 11 out of 13 imported schistosomiasis cases (84.62%) were distributed in the inner suburban districts where no O. hupensis snails were found at the same time. From 2010 to 2015, 9 out of 10 imported schistosomiasis cases (90%) were distributed in the outer suburban districts where O. hupensis snails were found at the same time., Conclusions: The number of imported schistosomiasis cases in Shanghai is on the downward trend. However, the threat of imported schistosomiasis to the prevention and control of schistosomiasis in Shanghai City should not be ignored.

Objective: To compare the application effects of three methods, namely microscopic examination, antigen detection (RDT) and nucleic acid test (PCR) in malaria detection between municipal and districts/counties centers for disease control and prevention in Shanghai, and analyze the malaria detection ability of the laboratories in Shanghai., Methods: The blood smears, whole blood samples, case review confirmation records and case data of malaria cases and suspected cases in Shanghai from 2012 to 2015 were collected by Shanghai Municipal Center for Disease Control and Prevention, and the detection results were analyzed and compared., Results: A total of 212 samples with complete data were submitted by all districts (counties) in Shanghai from 2012 to 2015, the samples submitted by Jinshan Districts were the most (41.98%), and among the first diagnosis hospitals, those submitted by the tertiary hospitals were the most (82.07%). The submitted samples in the whole year were increased gradually from January to October. All the 212 samples were detected by three methods (the microscopic examination, RDT and PCR) in the laboratory of Shanghai Municipal Center for Disease Control and Prevention, and 167 were tested and confirmed comprehensively as positives, accounting for 78.77%, and 45 were confirmed as negatives, accounting for 21.23%. The samples were detected by the method of microscopy and domestic RDT in the laboratories of the centers for disease control and prevention at district/county level, totally 153 were tested as positives, accounting for 72.17%, 41 were unclassified, accounting for 19.34%, 53 were negative, accounting for 25.00%, and 6 were undetected, accounting for 2.83%. The coincidence of microscopic examination between the report hospitals and the centers for disease control and prevention at district/county level was 78.16%, and the coincidence between centers for disease control and prevention at district/county level and municipal level was 93.20%. The utilization rate of RDT in the laboratory of district/county level was 73.58%. The coincidence of RDT tests between those domestic and imported was 93.59%. Compared with the detection results by municipal center for disease control and prevention, 37 samples were misjudged by the laboratories of district/county level. Almost all (99.37%) of the confirmed malaria cases were imported overseas, including Africa (85.44%), Asia (13.92%) and America (0.63%)., Conclusions: The surveillance after malaria elimination in Shanghai should be carried out by combining with different detection methods and resource integration.

Objective: To observe ten-year prognosis of patients with latent Keshan disease (KD) and to determine its associated risk factors., Methods: A total of 448 patients with newly diagnosed latent KD were monitored and followed up for 10 years. Their ECG abnormalities were classified as major or minor using the Minnesota Code. COX proportional hazards regression models were established to identify risk factors associated with the development of chronic KD., Results: A final sample of 414 cases was included in analyses, with an average of (112.9 ± 17.5) months of follow-up. At the end of follow-up, 92 (22. 2%) patients developed chronic KD. Older age (> 15 years), male, family history of KD, smoking, lower level of blood selenium (< 60 µg/L), major ECG abnormalities, and 18.5 kg/m² ≤ body mass index (BMI) 23.9 kg/m² were associated with higher cumulative incidence of chronic KD. The COX regression models showed that major ECG abnormalities, BMI, selenium deficiency, hypertension, and ventricular premature complex (VPC) abnormalities contributed to increased risk of chronic KD. A positive linear correlation (r = 0.719, P < 0.01) between GPx activity and blood selenium concentration was found., Conclusion: Major ECG abnormalities, BMI, selenium deficiency, hypertension and VPC abnormalities are associated with the development of chronic KD.

Objective: To explore the effect of adipose-derived stem cells (ASCs) on the skin expansion rate in rabbit., Methods: The rabbit ASCs were isolated from fat tissue and cultured in vitro. The ADSCs were identified by cell immunofluorescence and marked by Edu staining.20 new Zealand rabbits were randomly divided into experimental(n =10) and control group(n =10).An area of 1.5 cm ×1.5 cm on the one side back of each rabbit was tattooed and one 30 ml round expander was implanted subcutaneously. ASCs suspension (1 ml) was injected subcutaneously in the experimental group, while serum free DMEM medium(1 ml) in control group. The expansion was proceeded regularly under constant pressure for 4 weeks.The expanded tattooed square area was measured on the 7th,14th,28th day and analyzed statistically. The expanded skin was harvested for histological study. Immunohistochemical staining was used to detect the expression of vascular endothelial cell marker CD31,and the microvessel density determination. The expression of epidermal growth factor (EGF) and vascular endothelial growth factor(VEGF)was detected by ELISA for skin tissue specificity. Western Blot was used for detection of CK19 in the epidermal cells., Results: The expanded skin thickness and expansion rate in experimental group were significant higher than those in control group (P ＜ 0.05). Compared with control group, the expression of CK19,CD31 and EGF, VEGF, as well as the microvessel density were all markedly increased in experimental group(P ＜0.05)., Conclusions: ASCs can increase the expansion rate of skin tissue by promotion of angiogenesis and tissue regeneration.

Objective: To investigate the effect of adipose-derived stem cells (ADSCs) combined with chitosan on the immediate retraction rate of rabbit expanded skin., Methods: ADSCs were isolated from rabbit fresh fat under sterile conditions and cultured to the 3rd generation by methods of enzymatic digestion; the specific surface markers and the differentiation into epidermal cells and cartilage cells were identified. Forty New Zealand white rabbits (aged, 2-3 months) were randomly divided into 4 groups (n = 10): control group (group A), ADSCs group (group B), chitosan group (group C), and ADSCs+chitosan group (group D). ADSCs cell suspension with the concentration of 5 x 10⁶ cells/mL was prepared. The skin expansion model was made by embedding 30 mL dilator into the back of rabbit. Chitosan (2%, 5 mL) was coated on the surface of the dilator in groups C and D, and ADSCs cell suspension (1 mL) was injected into the skin in groups B and D. Conventional tissue expansion was performed to expected capacity at 4 weeks, and maintained for 1 week. The expanded skin was harvested to measure the immediate retraction rate, and the thickness of skin, epidermis, and fibrous capsule with HE staining. Masson staining was used to observe the characteristics of collagen in the fibrous capsule, and immunohistochemical staining for CD31 to determine the microvessel density (MVD)., Results: ADSCs were successfully isolated, and had multiple differentiation ability. All the animals survived to the end of the experiment. The immediare retraction rate of group D was significantly lower than that of the other groups (P < 0.05), groups B and C were significantly lower than group A (P < 0.05), and group B was significantly lower than group C (P < 0.05). The histological staining revealed that there were more mature fibroblasts and coarse collagen fibers with regular arrangement in groups A and B; there were more naive fibroblasts and tiny and sparse collagen fibers in groups C and D. The thickness of skin and epidermis, and MVD of groups B and D were significantly larger than those of groups A and C (P < 0.05); the thickness of fibrous capsule of groups C and D was significantly less than that of groups A and B (P < 0.05); but no significant difference was found in the above indexes between other groups (P > 0.05)., Conclusion: ADSCs can promote angiogenesis and regeneration of the expanded skin, have no effect on the fibrous capsule. Chitosan can inhibit the proliferation of fibrous capsule, so a combination of ADSCs and chitosan can inhibit the immediate retraction of the expanded skin.

CYP1 subfamily genes in gills and liver of rainbow trout as biomarkers were studied to establish methods for quantitative mRNA expression analysis of these genes and to determine their expression pattern. Fish caged in various waters in the Haihe River (Tianjin) were analyzed. The mRNA expression patterns observed in Machangjian River and estuary site of Haihe River were markedly similar but at different levels, reflecting that those sites shared the similar pollution components but with different local pollution load. CYP1C1 and 1C3 were only induced at Gegu site and estuary site of Haihe River, indicating different types of CYP1 agonists in Machangjian River. Response patterns of multiple CYP1 genes in gills and liver could be applied in the monitoring strategy. The response patterns of CYP1 genes could be used for better understanding the relationship between complex mixtures of pollutants and biological response of organisms in aquatic environments.