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In order to study the role of alloying element Mo in the Fe-Cr-B wear-resistant surfacing alloy,plasma arc welding surfacing was used to prepare Fe-Cr-B wear-resistant surfacing alloy layer with different Mo contents on the surface of Q235 by adjusting the amount of molybdenum iron powder in the surfacing alloy powder.Scanning electron microscopy,XRD and other analysis and testing methods were used to study the effect of the change of Mo content on the microstructure and properties of Fe-Cr-B surfacing alloy.Results showed that when no molybdenum iron powder was added into the surfacing alloy,the surfacing alloy consisted of M2B and (Fe,Cr) phases.When the content of Mo in the surfacing alloy reached 2% (mass fraction),a new phase FeMo2B2 precipitated in the surfacing alloy.In such case,the surfacing alloy consisted of M2B,FeMo2B2 and (Fe,Cr) phases;and the Rockwell hardness of the surfacing alloy depended on the volume fractions of M2B,FeMo2B2 and (Fe,Cr).With the increase of Mo content,the Rockwell hardness and wear resistance of the surfacing alloy gradually increased.Compared with the surfacing alloy without Mo,the wear resistance of surfacing alloy with 8% (mass fraction) Mo was improved by 1.2 times.

Traumatic temporomandibular joint ankylosis refers to fibrous or bony fusion between the condyle and the glenoid fossa. It can cause problems with mouth-opening limitations, mastication difficulties, obstructive sleep apnea and hypopnea syndrome. When traumatic temporomandibular joint ankylosis occurs during childhood, it can cause facial asymmetry, micrognathia, and malocclusion, which significantly affect the physical and mental health. Once temporomandibular joint ankylosis occurs, it will be refractory and recurrent. The pathogenesis of temporomandibular joint ankylosis has not been completely elucidated and has always been a research hotspot in the oral and maxillofacial fields. In this paper, worldwide research was conducted, and the pathogenesis of traumatic temporomandibular joint ankylosis was clarified, such as “damage of condyle”,“disc displacement or rupture”,“damage to the glenoid fossa” and “lateral pterygoid muscle distraction”. The relative pathogenesis hypotheses were summarized, such as “hematoma organization” and “lateral pterygoid muscle distraction osteogenesis”. The related pathogenesis of traumatic temporomandibular joint ankylosis was discussed based on the latest cytology and molecular biology research.

Based on the panel data of 30 provinces from 2011-2021, the tenacity of Chinese pig feed industry chain was measured by the entropy method, and the current development situation and regional characteristics of the tenacity of pig feed industry chain were analyzed. A bidirectional fixed effect model was used to explore the influencing factors of the resilience of Chinese pig feed industry chain. The restults showed that during the research period, the toughness of Chinese pig feed industry chain rose slowly, and showed a cyclical rising trend with the appearance of pig cycle. Based on a dimensional perspective, the improvement of the resilience of Chinese pig feed industry chain mainly benefits from the effective improvement of basic strength and resistance. From a regional perspective, the most resilient pig feed industry chain in China is in sustainable production areas, followed by restricted production areas, core production areas, and finally suitable production areas. From the perspective of influencing factors, the economic development level, technological innovation level, financial development level, and transportation convenience all had a significant role in improving the toughness of Chinese pig feed industry chain. The study indicates that exploring the practical path to enhance the resilience of Chinese pig feed industry chain can provide useful reference for accelerating the construction of a new pattern of Chinese pig feed industry chain. [ABSTRACT FROM AUTHOR]

BACKGROUND The content of gallium in coal fly ash is 12-230μg/g. The determination of gallium in coal fly ash is crucial to realize the high-value-added utilization of coal fly ash. As a sample pretreatment method, the conventional open wet digestion method has limitations including a large amount of hydrofluoric acid, corrosion of analytical instruments, long dissolution time, the loss of elements, and environmental pollution. Microwave digestion has the advantages of complete digestion, minimal loss, and short digestion time, which can effectively solve the shortcomings of the open wet digestion method. OBJECTIVES To develop a good method for the determination of gallium in coal fly ash. METHODS The coal fly ash was collected from a power plant in Inner Mongolia. The sample was digested with nitric acid (5.0mL), hydrofluoric acid (1.0mL), hydrochloric acid (5.0mL) and perchloric acid (1.0mL) by microwave digestion and then determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). RESULTS The results showed that gallium could be leached totally using HNO3-HF-HCl-HClO4 (5:1:5:1, V/V) when the temperature was 190℃, the time 30 minutes and the microwave power 1400W. The limit of detection was 0.004mg/L. The relative standard deviation (RSD) was 1.7% with the recoveries ranging from 95.1% to 100.9%. CONCLUSIONS ICP-OES with microwave digestion method adds hydrochloric acid and reduces the amount of hydrofluoric acid, thus shortening the time of removing fluoride and reducing the damage to instruments. The method is easy to be used for the determination of trace gallium in coal fly ash.

The experiment aimed to investigate the antibacterial activity of 4-substituted terpyridine zinc-metal complexes. The MICs of these metal complexes against Staphylococcus aureus, Salmonella, Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus, and Streptococcus agalactiae were determined by the microbroth dilution method. The study observed the effects of the metal complexes on bacterial growth, bacterial cell morphology, cell membrane permeability, and intracellular protein expression after the interaction with the complexes, aiming to explore the antibacterial mechanism against Staphylococcus aureus. The results showed that 4-substituted terpyridine zinc-metal complexes exhibited the higher antibacterial activity against Staphylococcus aureus and Vibrio parahaemolyticus. Following the interaction with the complexes, Staphylococcus aureus showed delayed growth, bacterial cells underwent shrinkage and rupture, increased cell membrane permeability, and reduced intracellular protein expression. The study indicates that 4-substituted terpyridine zinc-metal complexes may inhibit bacterial activity by disrupting the bacterial cells or suppressing protein expression. [ABSTRACT FROM AUTHOR]

BACKGROUND The low-temperature nitrogen (N2) adsorption-desorption method has been widely used to evaluate the pore structure of shale, however, the different analytical conditions such as degassing temperature and degassing time were reported in the literature. In addition, closure of the hysteresis loop often occurs in the test results, which seriously affects the accuracy of the structural parameters such as pore size distribution. BAOBJECTIVES To evaluate and explore an effective method for measuring pore size distribution in shale, using the black shales from the Department of Chongqing 1 well Lower Cambrian Niutitang Formation. METHODS Measurement conditions using low-temperature N2 adsorption method to analyze the shale pore size distribution. The effects of sample weight, degassing temperature, heating rate, and degassing time on the analytical results were systematically discussed. A reliable measurement method of pore size distribution is established by further optimizing the parameters, which has been successfully used in the determination of other shale samples. RESULTS The results show that the isothermal adsorption-desorption curves of the samples are inverse C type, which belong to the V type of BDDT isotherm adsorption curve proposed by Brunauer et al. The hysteresis loops belong to the H4 type in the IUPAC classification, which corresponds to the narrow slit-like pores, indicating that there are a large number of micropores in the shale, in addition to the mesopores with a peak pore size concentrating at 3.5-4.5 nm and a certain number of macropores. CONCLUSIONS Degassing temperature is the main factor affecting the analytical results. This study complements the exploration on the testing method of pore size distribution in shale and provides the key parameters for further study of shale gas in China.

The experiment was to study the quality change of cottonseed shell and sugar beet pulp after fermentation. The experiment adopted a dual factor cross grouping design. SBP and CSH were mixed according to fresh-weight ratio of 70:30, 75:25, 80:20 and 85:15, respectively. Mixing storage was carried out by adding fermentation bacteria and not adding fermentation bacteria. The experiment was divided into eight groups with three replicates in each group. Sealed fermentation was carried out for 1, 2, 6 months. The results showed that the sensory rating of fermented feed in all groups was above good, and the top sensory rating of fermented feed in CSH-A30 group, CSH-N30 group, CSH-A25 group, CSH-N25 group and CSH-A20 group was excellent. At the second month of fermentation, cottonseed shell supplemental level had a very extreme effect on DM content of fermented feed (P<0.01), an extreme effect on NDF content (P<0.05), but no significant effect on ADF content (P>0.05). The content of NDF and ADF in fermented feed in CSH-A group were significantly higher than those in CSH-N group (P<0.05). The content of FGP in fermented feed was extremely lower than that before fermentation (P<0.01), and the FGP removal rates were 71.7% and 82.7% at the second month and the six months of fermentation, respectively. The FGP removal rate of fermented diets in CSH-A group was significantly higher than that in CSH-N group (P<0.05). The content of NDF, ADF and FGP of fermented feed were extremely interacted with the added amount of cottonseed shell and the added strain at the first month and the sixth month of fermentation (P<0.01). Compared with before fermentation, DM content of fermented feed was decreased by 4.8% (P<0.01), NDF content was increased by 3.3% (P>0.05) and ADF content was increased by 9.3% (P<0.01) when fermented for two months. DM content of fermented feed was decreased by 5.8% (P< 0.01) when fermented for six months. ADF content was increased by 9.6% (P<0.01). The experiment indicates that the mixture of 70%*75% sugar beet pulp and 25%*30% cottonseed shell are suitable for fermentation for two months. [ABSTRACT FROM AUTHOR]

[Objectives] To investigate the morphological effects of infection of honeybees by Nosema ceranae, including the main tissues infected, the effects on protein expression in the midgut and the regulation of the honeybee immune response. [Methods] Total honeybee midgut proteins were extracted and screened using SDS-PAGE and differentially expressed proteins identified using LC-MS/MS. Differential expression of proteins was verified with semi-quantitative, and quantitative, RT-PCR. [Results] There was no significant difference in the body weight of infected and uninfected (control) Apis cerana cerana Fabricius or Apis mellifera Ligustica. However, there were significant differences in the intestinal morphology of infected and uninfected bees. Furthermore, two differentially expressed midgut protein bands were identified in A. mellifera and A. cerana cerana. Thirty-five candidate proteins were obtained by MS in A. mellifera and 11 in A. cerana cerana. Four days after infection, expression levels of arginine kinase (AK) and glycerol triphosphate dehydrogenase (GPDH) in A. mellifera, were up-regulated 2.02 times, 2.21 times, respectively, relative to the control group, whereas thioredoxin reductase (TrxR) and arginine in A. cerana cerana were up-regulated 1.72 times, and 1.88 times, respectively. All data were consistent with the results of SDS-PAGE analysis. [Conclusion] The expression of proteins related to basic metabolism, immune response, oxidative stress and energy metabolism in the honeybee midgut (such as AK and GPDH in A. mellifera and AK and TrxR in A. cerana cerana) were significantly up-regulated after infection by N. ceranae, suggesting that these proteins may be involved in the immune defense of intestinal tissues. This study provides a rich data base for in-depth study of the immune and metabolic responses of the honeybee midgut to infection by N. ceranae. [ABSTRACT FROM AUTHOR]

Since a lot of pattern matching in the process of dictionary set establishment and three-dimensional(3D) reconstruction, the super dimension algorithm takes a long time and is difficult in practical application. To solve this problem, a super-dimensional reconstruction algorithm based on porosity classification is proposed, which can greatly reduce the time cost of 3D reconstruction. First, the dictionary sets are classified by the porosity of dictionary elements. Then, the porosity classification dictionary is used to search according to porosity during reconstruction, and the corresponding dictionary interval is searched first. Based on the 3D reconstruction of different training images and porosity distribution, an adaptive search range determination method is proposed. Finally, the effectiveness of the proposed super dimension algorithm is verified by multiple reconstruction of the training images of high, medium and low porosity, a comparative analysis is made on the reconstruction results of the traditional Super dimension algorithm and the proposed algorithm in terms of the statistical characteristic function, pore-throat parameters and reconstruction time. [ABSTRACT FROM AUTHOR]

The silicone rubber for insulation coatings has been prepared with α, ω-dihydroxy polydimethyliloxane as the base rubber and calcium carbonate or fumed silica as the reinforcing filler. The influence of types and amounts of reinforcing fillers on the performance of silicone rubber are discussed. The results show that the silicone rubber with light nano-calcium carbonate has better thixotropy, higher tensile strength and elongation at break; whereas the silicone rubber has no thixotropy with heavy calcium carbonate as a reinforcing filler, and low tensile strength and elongation at break are relatively low. When nano-calcium carbonate is used as filler, the particle size of calcium carbonate increases from 50 ~70 nm to 100 ~ 120 nm, the density of silicone rubber increases from 1.38 g/cm³ to 1.48 g/cm³, however its tensile strength decreases from 2.45 MPa to 2.26 MPa, and the elongation at break decreases from 313% to 266%. As the consistency value remains the same, the tensile strength decreases from 2.45 MPa to 1.03 MPa, the elongation at break increases from 263% to 313% and then decreases to 296%. When fumed silica increases from 15 phr to 35 phr, the density of silicone rubber increases from 1.03 g/cm³ to 1.12 g/cm³, the consistency value decreases from 9.8 to 6.5, the tensile strength first increases from 2.49 MPa to 2.91 MPa and then decreases to 2.61 MPa, the elongation at break first increases from 294% to 373% and then decreases to 339%. When silicone rubber was prepared with 25 phr fumed silica T30, it has a density of 1.08 g/cm³, a consistency value of 8.0, a tensile strength of 2.91 MPa, and an elongation at break of 373%. The normal breakdown voltage of the wire coated with silicone rubber is 43.1 kV, and the breakdown voltage retention rate after 7 days' immersion in water is 86.5%, which can be used for insulation transformation of bare overhead lines. [ABSTRACT FROM AUTHOR]

Ecological and traditional theoretical biology experiments were conducted to study the allometric growth of larval and juvenile clown anemonefish Amphiprion ocellaris at their early life stage, thus providing fundamental data in artificial propagation of clown anemone fish. The 11th day post hatch of fish was the junction between the larval and juvenile clown anemone fish. The results indicated that organs of feeling, feeding, and swimming developed and differentiated rapidly with allometric patterns during the larval and juvenile stage. As for head organs, snout length, eye cross, mouth width and head height exhibited positive allometric growth in larval stage, while the snout-gill slit distance and eye diameter exhibited negative allometric growth. As for torso region organs, body height, trunk length, tail length, caudal peduncle length, caudal peduncle height and body thick exhibited positive allometric growth in larval stage, and only head length exhibited negative allometric growth. As for swimming organs, caudal fin, dorsal fin, pectoral fin, pelvic fin and anal fin all exhibited positive allometric growth. In juvenile stage, the head, torso and swimming organs of the clown anemone fish were all negative allometric growth. The allometric development of the key organs of clown anemone fish has important ecological significance for adapting to changes in environmental factors. [ABSTRACT FROM AUTHOR]

According to the repair technology of steel pipe pile anti-corrosion, we developed a set of automatic control system based on PLC and upper computer control, which on the circumference of the walking part adopts high speed counter to determine the circumferential walking position spray gun device, according to the control of lance position to finish the walk, spraying, lifting, and other functions. In order to improve the response speed of the system, we used the high-speed counting module hardware interrupt function to achieve control of the circumference of the walking mechanism, which has improved the control precision of the control system. [ABSTRACT FROM AUTHOR]

Aluminum nanoparticles are tried to be prepared by liquid chemical method to obtain their controlled microstructures. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy dispersive spectrometer (EDS) are applied to characterize the aluminum nanoparticles. The effects of processing parameters including molar ratio of AlCl3 to LiAlH4, the adding amount of catalyst and the decomposition temperature on the structure, morphology and composition of the aluminum nanoparticles are studied in detail. The optimal preparation condition is achieved when the molar ratio of AlCl3 to LiAlH4 is 1:6, the adding amount of catalyst is 0. 04 mL, and the decomposition temperature is 110 °C. The obtained aluminum is spherical-like with an average size of 50 nm and contains the minimum impurity elements Cl and Ti. [ABSTRACT FROM AUTHOR]

To thoroughly investigate biochemical characteristics of the humic activated sludge and action mechanism, the humic biological pellets were tested by means of SEM-EDAX. The results show that the main composition elements in humic biological pellets are C, 0, Si, and there are small amounts of Al, S, Fe. Compared to conventional activated sludge, the number of typical bacteria, nitrifying bacteria, nitrosobacteria, denitrifier and actinomycetes in humic activated sludge were significantly higher. Organic matter content in humic activated sludge is less than that in conventional activated sludge, but the humic acids content is higher. The humification degree of humic activated sludge is considerably higher than that of conventional activated sludge. The SBR reactor operated under humic activated sludge process performed excellent pollutant removal efficiency than conventional SBR reactor, the removal efficiency of C0DCr, TN and TP is 4%, 10% and 14% higher respectively. [ABSTRACT FROM AUTHOR]

To solve the problems of moisture absorption and aggregation of superfine AP (ammonium per-chlorate) and the aggregation of nano-sized catalysts in composite propellants, the CuO/AP/HTPB (hydroxyl-terminated polybutadiene) nanocomposites are prepared without introduction of other non-components of the composite propellants. Firstly, the CuO/AP nanocomposites are prepared by a novel ceramic membrane anti-solvent crystallization method, and then the CuO/AP/HTPB nanocomposites are prepared by solvent evaporating method. The size, morphology and structure of the resultant nanocomposites are characterized by SEM, HRTEM, FT-IR, ICP and XRD. The moisture absorption property of the nano-composites is also investigated. The results show that the CuO/AP/HTPB nanocomposites particles are the hexahedrons with the size of no more than 6 µm, and CuO nanoparticles exhibit better dispersion. The outer compact HTPB shell could prevent the moisture absorption of the superfine AP effectively. [ABSTRACT FROM AUTHOR]

Electric power steering(EPS) is a complicated electro-mechanical system. Control strategy plays a decisive tale in the process of assistance. Based on the kinetics analysis, mathematics model and Simulink based simulation model of electric power steering were established. Low-pass filter was used to reduce the tracking error for determined structure of the control system. Further, close-loop control was realized by using steering torque and motor current as feedback signals respectively. Simulation and experiment show that the proposed control strategy could reduce tracking error effectively, and the dynamic response of the system is good. [ABSTRACT FROM AUTHOR]

A systematic investigation to understand the impacts of the variable-thickness blade on the structural strength and performance of the first stage impeller for a domestic large flow centrifugal compressor is undertaken. The geometric models of 9 shrouded impellers with variable-thickness blade are mainly established by CAD software Solidworks, static structural analyses are carried out using finite element software ANSYS, and CFD simulations are performed with the CFX code. Emphases are placed on the variation of maximal von Mises stress in FEM analyses, and the distinction of impeller internal flow behavior in CFD simulations. The variable thickness of. blade is found to exert the great influence on the structural strength and performance of a centrifugal compressor. Furthermore, the computational results indicate that the appropriate increase of blade thickness close to trailing edge can remarkably improve the strength and aerodynamic characteristics of a shrouded impeller. Finally, the theoretical bases are given for the structural optimization and the performance improvement of a large flow centrifugal compressor and a nuclear reactor coolant cycling pump impellers. [ABSTRACT FROM AUTHOR]

Based on the FE software - ABAQUS, a simulation model was established to research into the construction and running process of the preloading spiral case keeping constant internal water pressure of hydropower station. The model firstly takes into account the surrounding concrete constructing keeping a preloading internal water pressure with constant value, then the removing of the preloading load and initial gap established, and finally the refilling of water with normal operation. The load-bearing properties both by spiral case steel liner and the surrounding concrete and the concrete damage developing process were studied mainly. Taking a large preloading spiral case as a real model, 3D-nonliner simulation was carried out, and the experimental results were compared with those of the traditional simplification model. Through the analysis of the main differences between two models and discussion of the developing and closing process of the gap between steel liner and the outer concrete structure, it is concluded that the non-uniform distribution and too-earlier closing of the gap are the main reasons of the higher stress level of the concrete and the damage developing. The simulation model could represent more practically the bearing characteristics and the operation properties of the preloading spiral case, and could be taken as a reliable simulation method for the structure design of the spiral case and rebar's playing. [ABSTRACT FROM AUTHOR]

Based on the error analysis of linear frequency modulated (LFM) intermediate frequency (IF) signal generator circuit, a novel error model in frequency domain was established. The model divided the signal generator circuit into two parts, the non-ideal LFM baseband signal generator circuit and the ideal IF modulator. Then a new calibration algorithm is proposed. Through changing the ROM data, it achieved the purpose of circuit error correction. Furthermore, a structure to realize the calibration algorithm was designed. Finally, the simulation results verified the excellence of the calibration algorithm and the correctness of the structure. [ABSTRACT FROM AUTHOR]

According to the structure of sum-difference patterns phase-comparison two-dimension mono-pulse radar system, the system is divided into three parts, including the antenna-comparator, comparator, and channel processing circuitry. The impact of their non-ideal to the performance of angle measurement is analyzed and simulated. Some meaningful conclusions are acquired. The amplitude imbalance of antenna-comparator has influence on measured angle value but sign, and the phase imbalance has influence on both the measured angle value and sign. The impedance inconsistency of comparators affects both measured angle value and sign. The amplitude imbalance of channel processing circuitry affects the measured angle value and the phase imbalance affects measured angle sign. Furthermore, in the non-ideal factors, the impact of phase imbalance of antenna-comparator is the least, and the amplitude imbalance of antenna-comparator as well as the impedance inconsistency of comparators is great. [ABSTRACT FROM AUTHOR]

Based on the monitoring data about the crest displacement of a gravity dam, the component of horizontal displacement caused by impounded water was separated by progressive regressive method. At the same time, an inverse problem about elastic parameter of dams and basic rocks identification using improved genetic algorithm was analyzed as an optimization problem. Also, during the inverse calculating process, contact elements were used to simulate the longitudinal joints of the dam. It is shown that the methods proposed are coincident better with the actual structure, and the results of the inverse analysis are reasonable and reliable in high degree. [ABSTRACT FROM AUTHOR]

With the increase of unit capacity of hydro-generators, the spiral case becomes a giant hydraulic structure with very high HD value, but its dynamic characteristics which should be paid particular attention to in the design stage have rarely been touched both in theory and practice. Three typical manners of steel spiral casing (SC) embedded in concrete, i. e., manner of SC embedded in concrete with soft cushion layer (MSCL), manner of SC embedded in concrete while holding a certain water head inside SC (MHWH) and manner of SC embedded directly in concrete (MD), were researched on the performances of a giant spiral case performed by 3-D finite element methods. To optimize the design of the giant spiral case, free-vibration and stiffness behaviors, dynamic responses under water pressure pulsation and anti-fatigue performance were analyzed and compared respectively. Results show that the influence of different embedment manners on the static and dynamic performances of the powerhouse is minor and should not be the control factor while selecting embedment manners. [ABSTRACT FROM AUTHOR]

Based on the concept of operator-valued metric spaces, the definitions of operator-valued contraction map and expansive map were introduced, and furthermore, the corresponding fixed point theorems were proven. As an application, the existence and uniqueness of a kind of integral equation of Fredholm type is given. [ABSTRACT FROM AUTHOR]

A mechanism, which uses a digital pan-tilt and a beam from laser rangefinding sensor as virtual pole to measure the position and pose of cylinder-like object, is presented. The structure, constitution and measuring principle of the mechanism are described in detail. Calculation method and formulas are also given. The position and pose of an ammunition can be synchronously measured using the given mechanism and algorithm if the positions of two points in space are known. The mechanism can be used for explosive ordnance disposal robot for the position and pose measurement of ammunition. The measured data can be used to guide the route planning and autonomous movement of robot arm. [ABSTRACT FROM AUTHOR]

Objective To compare the consistency of quantitative ultrasound(QUS)and dual-energy X-ray absorptiometry(DXA)in measuring bone mineral density(BMD)of adults aged 18-40 years in Guangzhou and evaluate the diagnostic value of QUS for identifying low bone mass.Methods DXA was employed to measure the BMD and QUS to measure the speed of sound(SOS)in 731 participants.The Bland-Altman analysis was performed to evaluate the consistency of Z scores between SOS and BMD.With the BMD Z ≤-2.00 as the diagnostic criterion for low bone mass,the receiver operating characteristics curve of QUS was established,and the area under the curve(AUC)and the sensitivity,specificity,and correct diagnostic index for the optimal cut-off of SOS Z score were calculated.Results The results of Bland-Altman analysis showed that the mean differences in the Z scores of SOS and BMD in males and females were 1.27(-0.94 to 3.47)and 0.93(-1.33 to 3.18),respectively.The AUC of SOS Z score in the diagnosis of low bone mass in males and females was 0.734(95% CI =0.380-0.788)and 0.679(95% CI =0.625-0.732),respectively.In males,the optimal cut-off of SOS Z score for low bone mass was -0.35,with the sensitivity,specificity,and correct diagnostic index of 64.1%,68.6%,and 0.327,respectively.In females,the optimal cut-off value of SOS Z scores for low bone mass was -1.14,with the sensitivity,specificity,and correct index of 73.9%,54.8%,and 0.285,respectively.Conclusion QUS and DXA show poor consistency in the diagnosis of BMD in the adults aged 18-40 years in Guangzhou,while QUS demonstrates an acceptable value in identifying low bone mass.

Objective To investigate the food preferences and explore the potential association between dietary knowledge and food preferences in residents aged 18 and over in China,so as to provide a basis for promoting healthy diets.Methods The latent class analysis was carried out with the 2015 cross-sectional data of China health and nutrition survey to categorize the food preferences among 8 783 residents aged 18 and over.Multinomial Logistic regression was adopted to assess the association between and dietary knowledge and food preferences.Results The food preferences of the residents aged 18 and over in China were classified into preference for less vegetable(3.28%),lack of preference(11.20%),diverse preferences(4.19%),and preference for healthy diets(81.33%).The proportion of the adults with dietary knowledge was 36.87%(3 238/8 783).The dietary knowledge varied in the adults with different food preferences(all P <0.001).After adjusting for gender,age,urban and rural distribution,education background,and annual household income,for each point increase in the dietary knowledge score,there was an estimated reduction of 22% in the probability of preferring less vegetables( OR =0.78,95% CI =0.76-0.80, P <0.001),13% in the probability of lacking preference( OR =0.87,95% CI =0.86-0.89, P <0.001),and 3% in the probability of having diverse preferences( OR =0.97,95% CI =0.94-1.00, P =0.030).Compared with those lacking dietary knowledge,the individuals with dietary knowledge had a 77% less probability of preferring less vegetables( OR =0.23,95% CI =0.16-0.32, P <0.001),a 55% less probability of lacking preference( OR =0.45,95% CI =0.39-0.53, P <0.001),and a 23% less probability of having diverse preferences( OR =0.77,95% CI =0.61-0.96, P =0.023).Conclusions The residents aged 18 and over in China presented four food preferences,including preference for less vegetables,lack of preference,diverse preferences,and preference for healthy diets,the last of which had the highest proportion.The individuals with lower levels of dietary knowledge have higher probability of preferring unhealthy food.

Objective To analyze the expression of cyclooxygenase-2 (COX-2) in the patients with snow-white sign of advanced colorectal adenoma (ACA) and explore its clinical significance.Method Western blotting was employed to determine the expression of COX-2 in the adenoma tissue and the normal tissue adjacent to the adenoma tissue (>5 cm away from the distal end of the adenoma tissue) of 40 ACA patients with snow-white sign and 40 ACA patients without snow-white sign.Results The appearance of snow-white sign in ACA patients was associated with patient age ( P =0.001) and not associated with sex,smoking history,drinking history,ethnic groups,family history of colorectal cancer,abdominal pain,diarrhea,constipation,fecal occult blood,or tumor markers (all P >0.05).Snow-white sign mainly appeared in the ACA patients with multiple adenomas ( P =0.004),large adenomas ( P =0.006),adenomas in distal colon ( P =0.015),protruding polyps ( P =0.044),and late-stage pathology ( P =0.010).The occurrence of snow-white sign showed no difference in the ACA patients with different results of Japan NBI Expert Team classification ( P =0.502).The expression of COX-2 in the adenoma tissue was higher than that in the adjacent normal tissue in the patients with and without snow-white sign ( P <0.001, P =0.004).The patients with snow-white sign had higher expression of COX-2 protein in the adenoma tissue than the patients without snow-white sign ( P =0.001).The expression of COX-2 protein in the adjacent healthy tissue had no significant difference between the patients with and without snow-white sign ( P =0.603).Conclusions Snow-white sign is more like to appear in the ACA patients with young age,multiple and large adenomas,adenomas in distal colon,protruding polyps,and late-stage pathology.Moreover,the expression of COX-2 in the ACA patients with snow-white sign is significantly higher than that in the ACA patients without snow-white sign.The adults with snow-white sign are prone to cancerization than those without snow-white sign.

Objective: To develop monoclonal antibodies that can specifically recognize human von Willebrand factor (VWF) propeptide (VWFpp) in plasma, and establish a rapid and reliable method for the detection of VWFpp antigen in plasma by using the double-antibody sandwich ELISA with the obtained anti-VWFpp monoclonal antibody., Methods: The recombinant human VWFpp (D1 and D2 regions) protein expressed in eukaryotic cells was used as immunogen to immunize BALB/c mice with routine method, so as to obtain clones of fusion cells. After screening and identification, hybridoma cell lines secreting monoclonal antibodies against VWFpp were selected, and then double-antibody sandwich ELISA assay was used to construct VWFpp antigen detection kit for the determination of VWFpp in human plasma. The levels of VWFpp antigen in plasma of 12 leukemia patients who underwent bone marrow transplantation were dynamically detected., Results: Two hybridoma cell lines that can be subcultured continuously and secrete monoclonal antibodies against VWFpp were obtained and named SZ175 and SZ176 respectively. Identified by ELISA and Western blot, the antibodies could both specifically recognize VWFpp but couldn't recognize mature VWF (without propeptide). Based on the principle of double-antibody sandwich ELISA, monoclonal antibodies SZ175 and SZ176 were successfully made into a kit for detecting VWFpp antigen. The plasma VWFpp levels of leukemia patients before and after bone marrow transplantation were dynamically detected. The results showed that the plasma VWFpp levels of the patients after transplantation were significantly higher than those before transplantation., Conclusion: Two monoclonal antibodies against VWFpp were successfully prepared, and a double-antibody sandwich ELISA detection kit for VWFpp antigen was constructed, which provides a powerful tool for further study on the biological function of VWFpp, the clinical diagnosis and classification of von Willebrand disease (VWD), and the prognostic monitoring of endothelial injury-related diseases.

Objective: To investigate whether co-transfection of wild-type VWFpp with VWF mutant in D1 region is able to correct VWF defects in biosynthesis and secretion., Methods: Four VWF mutant plasmids were single transfected into HEK 293 cells, or co-transfected into HEK 293 cells with the wild type VWFpp plasmids. The VWF in supernatant and lysate of transfected cells were analyzed by ELISA, vertical VWF multimer electrophoresis. The retention of VWF in endoplasmic reticulum of transfected cells were detected by immunofluorescence confocal microscope., Results: In the vertical VWF multimer analysis, with co-expressing VWF mutant and VWFpp, the VWF multimer bands disappeared, and the VWF antigen in both supernatant and lysate of cells decreased, compared with the single expression of VWF mutant. Although the intracellular levels of VWF antigens decreased after co-expression, the retention rate of VWF mutant decreased in endoplasmic reticulum., Conclusion: VWFpp can reduce the retention of VWF in endoplasmic reticulum, assists the transport of VWF between subcellular organelles. However, VWFpp inhibits the biosynthesis and secretion of VWF about the mutant in D1 domain.

Purpose: CD133 +/- cells were isolated and purified from primary oral squamous cell carcinoma(OSCC) to explore the effects of different culture conditions on the maintenance and biological characteristics of CD133 + primary OSCC., Methods: CCK-8 was used to detect the ability of proliferation and cisplatin resistance between CD133 +/- cell subsets. Transwell assay was used to compare the invasive ability of two cell subsets under the action of cisplatin. Flow cytometry was used to detect the proportion of CD133 + cells cultured by serum free medium(SFM) (with or without leukemia inhibitory factor, LIF) or serum supplied medium (SSM). Subcutaneous tumor model in nude mice was used to verify the difference in tumorigenicity of CD133 +/- cell subsets. The transplanted tumor was removed for H-E staining and immunohistochemistry (IHC). SPSS 25.0 software package was used for statistical analysis., Results: Compared with CD133- cell subsets, CD133 + cell subsets had stronger ability of proliferation in vitro(P<0.05) and cisplatin tolerance(P<0.001). Cisplatin had a stronger effect on the invasive ability of CD133 - cell subsets than CD133 + cell subsets (P<0.01). No significant difference in the proportion of CD133 + cell between LIF-SFM and no-LIF-SFM was found (P>0.05); but compared with SSM culture method, SFM culture method could maintain the proportion of CD133 + cell better(P<0.05). CD133 + cell subsets showed stronger tumorigenic ability with fewer cells than CD133 - cell subsets in nude mice(P<0.05)., Conclusions: Serum free culture method can better maintain the characteristics of primary OSCC stem cells, but the addition of LIF has no significant effect on the maintenance of stemness of primary OSCC cells.

The index weight coefficients were determined by comparing the analytic hierarchy process(AHP), the criteria importance through inter-criteria correlation(CRITIC), and the AHP-CRITIC mixed weighting method. The comprehensive scores of index components(echinacoside, salvianolic acid B, paeoniflorin, and ointment yield) of each group in the orthogonal test were compared to optimize the extraction process of Congrong Shujing Granules. The results showed that the AHP-CRITIC mixed weighting method scientifically optimized the extraction process. To be specific, the decoction pieces should be added with the 6-fold amount of water and extracted twice, 1 h each time. After three verification tests, the average mass fractions of echinacoside, salvianolic acid B, and paeoniflorin were 0.72, 9.34, and 5.92 mg·g~(-1), respectively, and the average ointment yield was 47.18%. As verified by the AHP-CRITIC mixed weighting method and the orthogonal test, the optimized extraction process of Congrong Shujing Granules was stable and feasible and could be applied to industrial production.

Objective: To construct a mouse model of Glanzmann's thrombasthenia (GT) with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation by CRISPR/Cas9 technology, and then further explore the expression and function of glycoprotein αIIbβ3 on the surface of platelet membrane., Methods: The donor oligonucleotide and gRNA vector were designed and synthesized according to the ITGA2B gene sequence. The gRNA and Cas9 mRNA were injected into fertilized eggs with donor oligonucleotide and then sent back to the oviduct of surrogate mouse. Positive F0 mice were confirmed by PCR genotyping and sequence analysis after birth. The F1 generation of heterozygous GT mice were obtained by PCR and sequencing from F0 bred with WT mice, and then homozygous GT mice and WT mice were obtained by mating with each other. The phenotype of the model was then further verified by detecting tail hemorrhage time, saphenous vein bleeding time, platelet aggregation, expression and function of αIIbβ3 on the surface of platelet., Results: The bleeding time of GT mice was significantly longer than that of WT mice (P<0.01). Induced by collagen, thrombin, and adenosine diphosphate (ADP), platelet aggregation in GT mice was significantly inhibited (P<0.01, P<0.01, P<0.05). Flow cytometry analysis showed that the expression of αIIbβ3 on the platelet surface of GT mice decreased significantly compared with WT mice (P<0.01), and binding amounts of activated platelets to fibrinogen were significantly reduced after thrombin stimulation (P<0.01). The spreading area of platelet on fibrinogen in GT mice was significantly smaller than that in WT mice (P<0.05)., Conclusion: A GT mouse model with ITGA2B c.2659 C>T (p.Q887X) nonsense mutation has been established successfully by CRISPR/Cas9 technology. The aggregation function of platelet in this model is defective, which is consistent with GT performance.

Objective: To obtain the recombinant protein of spacer domain in von Willebrand factor cleaving protease (ADAMTS13), and further study its biological function in ADAMTS13., Methods: The prokaryotic expression vector was constructed by using the template of plasmid with full-length ADAMTS13, and then transfected into E coli., following the induction of IPTG with the low temperature (30 ℃). The recombinant protein was purified with Ni-NTA agarose column by gradient imidazole. The purity and immune activity of purified products were identified with SDS-PAGE and Western blot respectively. By Adding the recombinant protein to the plasma of immune-mediated thrombotic thrombocytopenic purpura (iTTP) patients, the activity of ADAMTS13 was tested., Results: The prokaryotic expression vector was successfully constructed and the protein of spacer domain with the high purity was obtained. Western blot showed that the recombinant fragment could both react with monoclonal antibody against 6×His and polyclonal sheep IgG against ADAMTS13 (Gln34-Trp688). The protein formed a main lane at the position of 15 kDa with SDS-PAGE. It was demonstrated that the recombinant protein could efficiently elevate the ADAMTS13 activity in plasma of iTTP patients to reach normal level by functional experiment., Conclusion: The recombinant protein has high purity and immune activity, which provides the experimental basis for further research on mechanism of iTTP involved in spacer domain.

Based on the latest monthly data of moderate resolution imaging spectroradiometer (MODIS)/Terra C6.1 aerosol optical depth (AOD), the temporal-spatial distribution and variability trend in AOD over China during 2001-2017 are analyzed to explore the distribution and variation characteristics of AOD in China. Regarding the spatial characteristics, the first prominent high-value center of the annual mean AOD was located in the industrially and economically developed areas of the North China Plain, Central China, the Yangtze River Delta region, the Pearl River Delta region, and the Sichuan Basin. The second prominent high-value center of the annual mean AOD was located in the dust aerosol-dominated areas of Taklimakan Desert. Two low-value centers of the annual mean AOD were located in the eastern part of Inner Mongolia to the north of Northeast China and the Tibet Plateau. Regarding the temporal characteristics, the AOD value peaked in eight areas in spring and summer. The annual mean AOD values in the Taklimakan Desert, Sichuan Basin, and Pearl River Delta peaked from March to May, and those in the North China Plain, Central China, and Yangtze River Delta peaked from May to July. The trend characteristics showed that during 2001-2006, the AOD in Northwest China and Inner Mongolia showed a downtrend, and that in the east-central China and the eastern part of southwest China showed a growth trend. During 2007-2012, the trend of AOD in the Tibetan Plateau and the Taklimakan Desert changed from decreasing to increasing. The growth trend of AOD in the North China Plain and the Sichuan Basin was weakened, and the AOD in the Yangtze River Delta showed a weak downward trend. During 2013-2017, the AOD in most areas of China showed a significant downward trend.