Search

Based on the independently developed 5 T magnetic resonance imaging (MRI) system and research needs of 13C metabolic MRI, a gradient coil and 1H/13C dual resonance radiofrequency (RF) coil system for small-bore MRI were designed. The gradient coil was designed by using the finite-difference stream function method, and the RF coil was designed as a saddle coil combined with a surface coil in a dual-resonance scheme. Numerical simulation analysis of the magnetic field distribution was carried out by using the finite-element method, and a set of gradient and RF coils for small-bore 5 T 13C MRI was successfully developed. The feasibility of the design scheme was verified using a home-made 5 T MRI system, and the magnetic resonance images of 13C-labeled urea phantom and 1H magnetic resonance images of mice head were acquired by experimental tests, which lays a foundation for 13C metabolic MRI based on dynamic nuclear polarization in the future.

Relation extraction, as a key task in natural language processing, plays a significant role in deepening language understanding, constructing knowledge graphs, and optimizing information retrieval systems. However, traditional supervised learning methods are not well-suited for real-world scenarios due to the continuous emergence of new relations and the lack of large annotated datasets. Although the advent of large language models has significantly improved the performance of many natural language processing tasks, they still cannot effectively address the challenges of few-shot continual relation extraction. To fully leverage the semantic knowledge of large language models to mitigate catastrophic forgetting and overfitting issues, a novel few-shot continual relation extraction method, LAFA (large language model augmentation and feature alignment), is proposed. This method enhances representation alignment through various strategies such as relation instance rewriting, semantic expansion, and enhanced relation representation. It effectively improves the model adaptability to new relations and the retention of old knowledge while maintaining low data and computational costs. Experimental validation on two relation extraction datasets, FewRel and TACRED, demonstrates that LAFA outperforms existing methods in few-shot continual relation extraction tasks, particularly achieving the best results in incremental stages. Ablation experiments further reveal the significant contributions of each module to overall performance. Moreover, the inference efficiency and cost of LAFA are substantially lower than those of existing large language model-based methods, and it boasts strong scalability, being able to adapt to various language models.

For efficient electrochemical removal of Pb2+ from water bodies, Fe3O4 doped modified electrodes were prepared by loading a mixture of Fe3O4, powdered activated carbon, acetylene black and polyvinyl alcohol onto graphite paper with the coating method. The electrochemical removal of Pb2+ with Fe3O4-doped modified electrode was carried out in a differential column batch reactor mode, and the effects of voltage, temperature, operation time,concentration, and other factors on the Pb2+ removal performance were investigated. The reusability and stability of the electrode were evaluated based on cycle trials. The results showed that the prepared electrodes had abundant surface pores and uniform pore size. The removal of Pb2+ by the electrochemical system reached 98.73% after 150 min at a voltage of 1.4 V, and the extension of the operation time could significantly strengthen the removal of Pb2+. In the temperature range of 10-35 ℃, the increase of temperature was favorable for the electrochemical removal of Pb2+. The electrochemical system had good applicability and adaptability at different Pb2+ concentrations. With the increase of the initial Pb2+ concentration, the energy consumption for treating unit volume of Pb2+ wastewater increased gradually, but the energy consumption for removing unit mass of Pb2+ decreased on the contrary, The fitting results showed that the removal process of Pb2+ was in accordance with the pseudo-first order kinetics. The electrochemical system still maintained the original removal effect after eight cycles, presenting commendable reusability and stability.

【Objective】 Fragrant pear is a cash crop in Northwestern China and its growth relies on irrigation. This paper presents the results of an experimental study on the effect of drip irrigation amount on water consumption of the pear as well as water distribution in soil. 【Method】 The experiment was conducted from 2021 to 2023 in a pear orchard in Korla in Xinjiang. It consisted of four irrigation amount treatments: 3 750 (W0), 5 250 (W1), 6 750 (W2) and 8 250 m3/hm2 (W3). The control is surface flooding irrigation with an irrigation amount of 10 000 m3/hm2 (CK). For each treatment, we measured the change in soil water content and water consumption of the pears. 【Result】 Increasing irrigation amount led to an increase in soil water content. With the increase in irrigation amount, the variation coefficient of soil water content and fruit yield of the pear both increased first followed by a decline. The W2 treatment gave the highest fruit yield (7 285.91 kg/hm2), 1.4% to 20.89% higher than that in other treatments. The water use efficiency and irrigation water use coefficient both decreased as the irrigation amount increased. Throughout the entire growth period, water consumption of the pear varied from 444.83 to 695.27 mm. Water consumption during the rapid fruit expansion period of the pear, especially in the early stage, was the highest, varying from 3.77 to 6.16 mm/d. From 2021 to 2023, water consumption of the pear in W3 was 10.11% to 36.02% more than that in other treatments. In 2023, the water consumption of the pear in W2 was 3.74% to 7.15% higher than that in 2021 and 2022, in which the water consumption during rapid fruit expansion period of the pear varied from 4.71 to 5.48 mm/d. The crop coefficient of the pear during its entire growing period varied from 0.48 to 0.84. During the budburst and flowering stages, and the early stage in the rapid fruit expansion period, the crop coefficient of the pear was lower than that estimated from the FAO standard, while during the entire rapid fruit expansion and harvesting stage, the crop coefficient of the pear varied from 0.7 to 1.07 and 0.72 to 1.21, respectively. 【Conclusion】 The optimal drip irrigation amount for fragrant pear in Korla region should be not less than 6 750 m3/hm2.

Objective In order to understand the research on urban rail transit vehicle development in China in the past 20 years, Citespace software is used to make visual retrieval and analysis of the relevant literatures on this issue, and determine the cutting-edge hot topics. Method In the CNKI (China National Knowledge Infrastructure) paper database, periodicals are selected as the search scope, the year 2001-2020 as publication year, and subject ′vehicle′+full text ′urban rail transit′ as the search condition，9392 papers are exported in Refworks format. New data are generated by Citespace software creening and de-duplicating. The number and temporal characteristics of the literatures, keywords, citation frequency, cooperative relation of research institutions, research hot topics and cutting edge analysis are studied. Result & Conclusion The research shows that there are three research stages featuring steady growth, rapid growth and exponential growth corresponding to the years devided by 2008 and 2016 respectively. The research hot topics focuse on "traction", "braking", "dynamics" and "bogie" and others. The cutting edges of the research are "supercapacitor", "city railway", "vehicle maintenance", etc. Relevant scholars and research institutions are mainly concentrated in universities and main locomotive factories.

Pulmonary fibrosis is a progressive interstitial fibrotic lung disease with high mortality. Its pathogenesis is complex and involves the reprogramming of fatty acid metabolism. This reprogramming includes changes in de novo fatty acid synthesis, uptake, oxidation, and derivatives. It crucially influences alveolar epithelial cell survival, macrophage polarization, and fibroblast activation, thereby playing a significant role in either exacerbating or mitigating the disease. Understanding and intervening in the reprogramming of fatty acid metabolism offers potential strategies for prevention, diagnosing and treatment of pulmonary fibrosis.

Background In recent years, the promotion of "health-centered" concept and the increasing demands for health care of patients have placed greater demands on healthcare providers. The establishment of effective health care team is regarded as an important approach to improve service quality. The selection of objective and valid teamwork assessment tools is particularly important for the assessment of cooperation status among team members and team building. Objective To perform a systematic review of domestic and international assessment tools for medical teamwork, in order to provide a reference for the rational selection of medical teamwork assessment tools according to different situations. Methods Pubmed, CNKI, Wanfang and VIP databases were searched in April 2022 for literature related to medical teamwork assessment tools from January 2016 to April 2022. Literature screening and information extraction were performed independently by two investigators and cross-checked. The Chinese version of COSMIN study design checklist was used to evaluate the quality of the assessment tools. Results A total of 30 articles were included, involving 32 medical teamwork assessment tools, localized versions of the tools were also included in their original versions of the tools, and a total of 49 medical teamwork assessment tools were finally included. The results of the overall design and methodological quality evaluation of 32 medical teamwork assessment tools covered by 30 included papers showed that in terms of the overall design of the tools, 20 were considered as "very good", 2 as "good", and 10 as "vague"; in terms of the content validity, 1 was considered as "very good", 12 as "good", and 19 as "vague"; in terms of the construct validity, 19 were considered as "very good", 10 as "good", and 3 as "poor"; in terms of internal consistency, 29 were considered as "very good", 1 as "good", and 2 as "vague"; in terms of stability, 6 were considered as "very good", 8 as "good", 1 as "vague" and other relevant information was not reported. The assessment tools were divided into the interprofessional teamwork assessment tools (n=43) and intraprofessional teamwork assessment tools (n=6) based on the professional background of the team members. The interprofessional teamwork assessment tools were divided into the physician-nurse team assessment tools (n=20) and integration of multiple roles team assessment tools (n=23) including physicians, nurses, pharmacists, therapists, dietitians and others based on the job categories. Conclusion The research on the assessment tools of medical teamwork has received increasing attention from scholars at home and abroad. The content of the assessment tools is relatively rich, but further development is needed to construct a teamwork assessment tool specifically applicable to primary health care team.

Objective To explore potential function of IKAROS family zinc finger 1 (Ikzf1) in terminal erythroid differentiation. Methods Single-cell regulatory network inference and clustering (SCENIC) was used to predict transcription factors of terminal erythroid differentiation based on single cell transcriptomes of human and mouse bone marrow erythroid cells. Expression of the predicted Ikzf1 during terminal erythroid differentiation was acquired from public RNA-seq data and validated by RT-qPCR. Short hairpin RNA (shRNA) interference was performed to knock down Ikzf1 in mouse erythroid cells from fetal liver with a GFP cassette to mark successfully transfected cells. The knockdown efficiency in GFP+ cells was verified by RT-qPCR. The effect of Ikzf1 knockdown on erythroid differentiation and enucleation was analyzed by flow cytometry. Results SCENIC predicted that the transcription factor Ikzf1 regulated both human and mouse erythroid differentiation. RNA-seq data and RT-qPCR showed highly expressed Ikzf1 at proerythroblast and basophilic erythroblast stages of terminal erythroid differentiation. Ikzf1 expression was indeed down-regulated by shRNA in erythroid cells from mouse fetal liver. Flow cytometry analysis showed that knockdown of Ikzf1 affected terminal differentiation and significantly reduced the ratio of erythroid enucleation (P＜ 0.05). Conclusions Transcription factor Ikzf1 is highly expressed in early stage erythroblasts and involved in terminal erythroid differentiation as well as enucleation.

The novel coronavirus pandemic in early 2020 has been profoundly transforming people's lives. In China, countermeasures such as city and community lockdowns were successful in mitigating the epidemic. Such measures predominantly take effect by limiting close contacts between humans through work and school closures, for instance. However, high concentrations of human interactions are a feature of large urban areas, and daily commuting is a major source of the interactions, determined by the job-housing spatial relationship of the city. This study aims to explore the effects of optimizing the urban job-housing spatial relationship on mitigating disease spread. Taking Shanghai as an example, a multi-agent simulation model was established using NetLogo with a spatial granularity of 523×523 m grids to simulate disease spread through the daily basic activities of individual residents, including residence, working and commuting. The data used for the simulation were based on the current job-housing spatial relationship reflected by mobile phone grid data, from which a sample of 20 000 people with home and job locations was extracted to simulate the process of disease spread from 9 designated disease source locations. The selection of the source locations considered different location types of the Shanghai region, covering the central city area, the near suburbs and the outer suburbs. The measure of job-housing spatial relationship optimization was based on excess commuting. Using a method to simulate individual exchanging residences according to the principle of Pareto Optimality, the current excess commuting of Shanghai was found to approximately reach 69%. The job-housing spatial relationship was then measured as the extent of the excess commuting reduction. Analyses on the relationships between the optimization and the disease spread in space and time were conducted based on 20 simulations under each scenario of the 9 sources. The results showed that the proportions of the infected agents develop in S-shape curves with time, and the fastest spreads occur in the commuting periods. Diseases originating from sources that are closer to the city center spread faster than those originate from farther sources. Although 75% of the optimization constitutes the turning point for the job-housing spatial relationship to significantly postpone the spread, before this point, the influence of job-housing optimization on the spread time is limited. Such optimization can steadily reduce the spatial area of the spread, limit the scope of spread, localize the spread, and change its spatial mode from the "width-first mode" to the "depth-first mode." When the disease source is in the outer suburbs, the localization effect is particularly strong. Based on these findings, methods like job-housing balance, decentralizing jobs from central urban areas, and multi-center regional structures that can reduce commuting distances may constitute appropriate long-term strategies for urban epidemic intervention. The major contributions of the study are the exploration on the spatio-temporal regularities of infectious disease spread and epidemic intervention from the perspective of urban spatial structure, and the use of mobile phone data to provide relatively realistic base environment for disease spread simulation.

This paper proposes to apply Transformer model in the field of Chinese text automatic proofreading. Transformer model is different from traditional Seq2Seq model based on probability, statistics, rules or BiLSTM. This deep learning model improves the overall structure of Seq2Seq model to achieve automatic proofreading of Chinese text. By comparing different models with public data sets and using accuracy, recall rate and F1 value as evaluation indexes, the experimental results show that Transformer model has greatly improved proofreading performance compared with other models.

[Objective] Rhodamine B (RhB) is a typical triphenylmethane dye with a carboxyl structure and a type of recalcitrant organic pollutant. It can cause significant damage to human health and the environment when discharged into water bodies. Ultraviolet/hydrogen peroxide (UV/H2O2) technology uses UV light excitation to decompose H2O2 into hydroxyl radicals (•OH) with strong oxidizing properties. The standard electrode potential of •OH is 2.8 eV, which is much higher than those of ordinary oxidants such as O3, Cl2, and H2O2. UV/H2O2 technology has the advantages of rapid reaction, low selectivity with organic compounds, and good treatment effects. In addition, the hydrolysis products of H2O2 are water and oxygen, which are environmentally friendly and do not cause secondary pollution. Therefore, among many advanced oxidation methods, UV/H2O2 technology is receiving widespread attention and research. Herein, a comprehensive experiment was designed to degrade RhB by the UV/H2O2 process. [Method] The effects of process conditions such as H2O2 dosage, pH value, and UV light intensity on the removal efficiency of RhB by UV/H2O2 were explored by single-factor experiments. Response surface methodology (RSM) was employed to examine the interaction of the different influencing factors. A quadratic regression model for the RhB removal rate was constructed, and its accuracy was verified through experiments. UV-Visible (UV-Vis) spectroscopy and three-dimensional fluorescence spectroscopy were applied to confirm the removal effect of RhB. [Results] The results of the single-factor experiments indicated that the degradation process of RhB by UV/H2O2 followed the pseudo-first-order kinetic equation. Properly increasing the concentration of H2O2 improved the reaction rate and the degradation effect of RhB, but its excessive addition led to the self-loss of •OH. Weak alkaline conditions were more conducive to RhB degradation in UV/H2O2 systems. With the increased UV light intensity, the reaction rate constant k value significantly increased. The RSM results revealed that the interaction between H2O2 dosage and UV light intensity significantly affected RhB degradation. At a H2O2 dosage of 47.45 mL/L, the pH value was 8.11, the UV light intensity was 730 µW/cm², and the RhB removal rate could reach 92.44% after 120 min. The relative deviation between the experimental and predicted values of the model was 0.89%. The predicted values from the regression model established with Design-expert software were highly correlated with the experimental values, accurately reflecting the actual removal of RhB. The UV-Vis and three-dimensional fluorescence results showed that a large number of azo bonds were rapidly broken by the active components, and the polycyclic aromatic hydrocarbons in the molecular structure of RhB were disrupted, but some benzene derivatives were formed during the reaction. [Conclusions] The UV/H2O2 method could effectively degrade RhB dye wastewater. Single-factor experiments and RSM were used to optimize the conditions of the UV/H2O2 process, which helped improve students' understanding of the influencing factors of the reaction, kinetic fitting and optimization of experimental conditions in scientific research training, and cultivating students' scientific and rigorous style. [ABSTRACT FROM AUTHOR]

Objective To investigate the relationship between cytomegalovirus (CMV) seropositivity and the occurrence of cancer using the data from the third National Health and Nutrition Examination Survey (NHANES Ⅲ). Methods The retrospective analysis was performed on the subjects aged 17 or above who participated in NHANES Ⅲ from 1988 to 1994. Results Among 14718 participants, CMV existed in the participants with cancer history, weighted sero-prevalences of CMV in skin cancer and colorectal cancer patients were slightly higher.The percent of female with CMV seropositivity was 10% higher than that of male.Moreover, the possibility of CMV existence in female subjects with breast cancer, cervical cancer and uterine cancer was also slightly higher.Furthermore, CMV prevalence was increased with age (P < 0.01).Unadjusted Logistic regression indicated the presence of CMV was associated with cancer history, skin cancer and breast cancer (P < 0.01).However, such associations were no longer significant after adjusting potential confounders including gender, age, education, race, poverty income ratio, body mass index, smoking status and alcohol-use status. Conclusion The association between CMV seropositivity and cancer occurrence is not significant in general population.

In view of problems of randomness and subjectivity in determining weight of existing rockburst prediction methods，a discrete Hopfield neural network (DHNN) model for prediction of classification of rockburst intensity was proposed。The model selects stress coefficient, rockbrittleness coefficient and elastic energy index as evaluation index, divides rockburst grade into 4 stages, such as strong rockburst, medium rockburst, weak rockburst and no rockburst, then encodes them. The model need't normalize sample data with simpler encoding ,lesser iterations of network and better associative memory ability, only be converted to '1' and '-1' of the two value model, therefore, the classification prediction of rockburst intensity is more scientific and reasonable. The model can provide a new way for classification prediction of rockburst intensity in deep underground engineering. The prediction results of typical rockburst engineering examples prove the correctness of the model.

Forward-looking imaging technique can be used on phased array radar to detect and track the targets in front of the high speed motion platform. To solve the problem of discriminating the targets in the beamwidth, a forward-looking imaging method by integrating minimum variance and maximum likelihood spectrum estimation is proposed. Firstly, the approach of scanning the beam is used. The initial two-dimensional range-azimuth image is created with minimum variance spectrum estimation. Secondly, the regions in which the amplitude peaks exceed the threshold are searched to implement the second estimation. Simulation results have demonstrated the effectiveness of the approach to improve the targets' resolution capability in the applications involving correlated signals and low signal-to-noise ratios. [ABSTRACT FROM AUTHOR]

Dental diseases such as dental caries and periodontitis often lead to tooth loss, which is common in China. Clinically, oral restoration is mainly used for treatment. Zirconia, with excellent mechanical properties, good biocompatibility and better aesthetic performance, has become an ideal restorative material in the field of dental restoration. Traditional computer aided design/ computer aided manufacturing (CAD/CAM) subtractive manufacturing has the high processing accuracy and good marginal adaptation, but it has shortcomings such as material waste, tool wear and insufficient accuracy in the production of occlusal grooves. As a typical representative of rapid prototyping technology, additive manufacturing (3D printing) meets basic requirements for building precision, personalization and structural complexity allceramic crowns, and is expected to be a potential technology for the preparation of all-ceramic crowns. The progress of domestic and foreign research teams in the development and application of zirconia all-ceramic crowns using stereolithography 3D printing were reviewed. The ceramic slurry composition, design of printing process support structure, optimization of printing parameters, post treatment process route and evaluation of the performance of the printed products were reviewed and analyzed accompanying by a large number of examples for explanation. Finally, the challenges that will be faced in the future in the field of zirconia all-ceramic crowns via stereolithography 3D printing have been pointed out, and some suggestions have been provided. [ABSTRACT FROM AUTHOR]

The galloping of catenary wires may endanger the operation safety of electrified railways and cause great economic losses. To prevent such disasters caused by the galloping of catenary wires, this article proposes a non-invasive monitoring method of catenary wires galloping based on video image technology. The real-time images of catenary wires are obtained by using cameras installed in lateral direction, and the images are preprocessed to reduce computation. On the basis of extracting the edge contour of contact lines by region edge detection combined with morphological operation, Hough transform is applied to detect contact lines. Through coordinate conversion parameters obtained by camera calibration, the point to be measured in the center of the contact line is converted into world coordinate, and the motion amplitude and frequency spectrum of the target measuring point are calculated, and then alarm information is sent out according to the galloping limit value. The results of simulation test of catenary wires galloping monitoring show that this method can accurately obtain the motion parameters of the target measuring points, and thus estimate the galloping situation of the catenary wires and realize the galloping monitoring of the catenary wires. [ABSTRACT FROM AUTHOR]

To reveal the innate immunity of mast cells against recombinant VP1-VP4 protein of foot-and-mouth disease virus (FMDV), mouse peritoneal mast cells (PMCs) were pulsed with recombinant VP1-VP4 protein. The supernatants harvested from PMCs cultures were applied to the high throughput ELISA array. Our results show that the expression levels of CCL19, L-selectin, CCL17, and TNF alpha released from PMCs pulsed with recombinant VP1-VP4 were significantly down-regulated compared with PMCs alone (P<0.001). Surprisingly, in comparison with PMCs alone, the expression levels of CCL19, IL-15, IL-9, G-CSF, and Galectin-1 in PMCs with the mannose receptor (MR) inhibitor were significantly up-regulated (Plt;0.01), and the expression level of IL-10 was also remarkably up-regulated (Plt;0.05). Importantly, the protein expression levels in PMCs treated with MR inhibitor were higher than PMCs pulsed with VP1-VP4, including IL-10, IL-17, CCL20, IL-15, IL-9, L-selectin, CCL17, TNF alpha, and CCL19 (Plt;0.01) as well as CCL21, and G-CSF (Plt;0.05). Differential expression analysis in bioinformatics shows that both L-selectin and CCL17 were recognized as differentially expressed protein molecules (Log2(ratio)≤-1) when compared with PMCs alone. Furthermore, the up-regulation of the expression levels of CCL20, CCL19, L-selectin, and IL-15 in PMCs treated with MR inhibitor was defined as differential expression (Log2(ratio)≥1). These data indicate that PMCs are capable of secreting CCL19, L-selectin, CCL17, and TNF alpha spontaneously and the recombinant VP1-VP4 has an inhibitive potential to PMCs during their performance of innate immune response. Given the protein expression levels from PMCs pre-treated with MR inhibitor were significantly increased, it can be deduced that immunosuppression of FMDV is presumably initiated by the VP1 recognition of MR on mast cells.

Objective: To investigate the role of the dead macrophages infected by Brucella suis S2 strain in the initiation of immune response to Brucella., Methods: The mouse peritoneal macrophages were infected with Brucella suis S2 strain in vitro. After one hour, the cells were cultured in serum-free RPMI1640 medium for 5 days until all of them were dead because of starvation. The dead cell fragments and the bone marrow-derived dendritic cells (BMDCs) were co-cultured for 24, 48 and 72 hours, and then interleukin 12 (IL-12), tumor necrosis factor α (TNF-α) in the co-cultivation supernatant were detected by ELISA. The mouse macrophages marked by carboxyfluorescein diacetate succinimidyl ester (CFSE) were infected with Brucella suis S2 strain in vitro, and then were cultured without serum in the dark; the dead macrophages fragments and BMDCs labeled with anti-CD11c-PE were co-cultured for 1 hour away from light, and then the changes that BMDCs swallowed the fragments of macrophages were observed by laser scanning confocal microscopy. BALB/c mice were inoculated with the fragments of dead macrophages infected by S2 strain through abdominal cavity. After one week, a second immunization was done. The serum levels of IL-4, IL-2 and IFN-γ were detected with ELISA at 3 days post-secondary immunization., Results: The macrophages fragments infected by S2 strain could be swallowed by DCs. The level of TNF-α in BMDCs swallowing macrophages fragments infected by S2 strain was significantly higher than that in the control group, but the former did not secret IL-12. The levels of IL-2, IL-4 and IFN-γ in the sera from the mice inoculated with the macrophages fragments infected by S2 strain were dramatically higher than those in the control groups., Conclusion: The dead macrophages infected by Brucella suis S2 strain can activate DCs to present antigen and induce the anti-Brucella immune response.

Objective: To study the pattern recognition and activation effect of mast cells infected by Brucella (B.) suis S2., Methods: Mast cells derived from bone marrow in vitro were infected by B.suis S2. The change in the cell morphology was observed with Wrights-Giemsa's staining, and cell degranulation was tested with toluidine blue staining. The extracellular levels of histamine, IFN-γ and IL-12 of mast cells at 1 and 12 h after infection were detected by indirect ELISA. The uptake pattern of mast cells to B.suis S2 was determined by laser-scanning confocal microscopy. The expressions of TLR4 and TLR8 mRNA were detected by RT-PCR at 12 and 24 h after infection by B.suis S2, and the TLR4 and TLR8 protein expressions were detected by flow cytometry at 24 h., Results: The form of mast cells infected by B.suis S2 was obviously changed. Significant degranulation was observed at 1 h, and at 1, 12 h post-infection by B.suis S2, the content of histamine secreted by mast cells was significantly higher than that of normal control group (P<0.05), and IFN-γ and IL-12 were not found. At 30 min and 1 h, B.suis S2 bound to the mast cell surface and were not uptaken into the mast cells. Compared with the control group, the expression of TLR4 mRNA increased after 12 h infection by B.suis S2, and was reduced at 24 h. The expression of TLR4 protein rose at 24 h, but the expression of TLR8 mRNA and protein did not alter at 12 and 24 h after infection by B.suis S2., Conclusion: B.suis S2 can bind to the cell surface and activate mast cells, cause their degranulation, induce the release of histamine, but IFN-γ and IL-12 were not found during the observing time. The mechanism may be that B.suis S2 can be recognized by mast cells through TLR4 but can not be phagocytosed by mast cells.

Objective To make a comparison of the characteristics between macrophages and dendritic cells (DC) infected by Brucella suis (B. suis) S(2);. Methods Wrights-Giemsa's stainning was used to observe the cell morphology and calculate the phagocytic rate. ELISA was employed to detect the expressions of IL-12 and TNF-α in cell culture supernatants as well as the contents of IFN-γ and IL-4 in the co-culture with T cells. With annexin-V-FITC/PI double staining, the cell apoptosis rate was determined by flow cytometry. Results 1 h after infected by B. suis S(2);, the phagocytic rate of macrophages was (43.6±4.8)%, which was significantly higher than that of the DC (16.3±2.7)% (P<0.05). The apoptosis rates of normal macrophages and macrophages 6, 12 and 24 h after infected by B. suis S(2); were (3.09±1.21)%, (19.89±1.36)%, (22.73±2.21)% and (42.44±3.12)%, respectively, which were dramatically higher than those of the DC at the corresponding time points, being (1.82±0.01)%, (3.76±0.13)%, (7.87±0.56)% and (9.08±0.23)%, respectively (P<0.05). The levels of IL-12 secreted by macrophages 24 and 48 h after infected by B. suis S(2); were significantly lower than those by the DC (P<0.01). At 24, 48 and 72 h, the levels of TNF-α secreted by macrophages were dramatically lower than those by the DC (P<0.01), and the levels of IFN-γ in the co-culture supernatants of macrophages and T cells were significantly lower than those in DC and T cell co-culture (P<0.01). Conclusion Macrophages have a better ability in phagocytosing B. suis S(2); than DC and the apoptosis rate of macrophages is higher than that of DC after infected by B. suis S(2);, but in activating and inducing the cellular immune response and presenting antigen, DC are stronger than macrophages.