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Wearing a liquid cooling garment (LCG) that offers near-zone cooling improves the thermal comfort of pilots working in hot environments. Four LCG samples with different arrangements of tubes for distributing liquid were developed. Based on the analysis of the overall and local cooling efficiency of the four LCG samples using manikin tests, another novel LCG with a horizontal-vertical combined tube was proposed to achieve optimal cooling performance. Human trials were conducted to check the novel LCG for improving the thermal comfort of pilots in a hot indoor environment (40°C, 40% RH). The mean skin temperature of the subjects wearing the novel LCG was reduced by 1.9°C in the 120-minute-duration flying simulation work compared to the no-cooling scenario, and the greatest decrease in skin temperature (i.e., 5.7°C) was exhibited at the back waist. The thermal sensation at the upper body was improved to nearly neutral, and the heat stress level was reduced from moderate to slightly. The findings provide a guideline for designing personal LCG, thus benefiting the comfort and safety of pilots in hot cockpits.

As the simulation data of the Simufact Additive software was inconvenient to process, QT and structured query language (MySQL) database were used to develop the database to solve the processing of the simulation data. The GUI interface that has the functions of processing and saving the simulation data was designed. The interface developed by QT was used to start the Simufact Additive software, connect to the MySQL database and save the simulation data. The results showed that using MySQL as the management of simulation data has achieved better results in the post-processing of simulation data.

Developing fabrics with enhanced thermal protection is a cutting-edge topic in area of thermal protective clothing (TPC) for workers under heat hazards. Here, temperature-responsive NiTi shape memory alloy (SMA) filaments, which transform into a sinusoid form under a stimulus of temperature exceeding their austenite start temperature of 45.1 °C, were prepared. Nine composite fabrics (CFs) using SMA filaments and aramid yarns, different in filament interval, air gap orientation, aramid yarn type and fabric density, were fabricated and incorporated into traditional three-layer TPC fabric system, resulting in a four-layer smart fabric system (SFS) with adaptive structure. Thermal protective performance (TPP) tests demonstrated the addition of CF could significantly slow down the rise of temperature at skin surface and prolong the time to the first-degree burn. With the decrease of filament interval or increase of fabric density, TPP of SFS was improved due to more heat accumulation within and less heat conduction through the fabric. This study would inspire engineering CFs with enhanced TPP, thus pushing forward the development of smart technology in textile engineering.

Interface is the Achilles' heel in flexible electronics, where slipping, delamination, or cracking resulting from the intrinsic mechanical property mismatch of different materials might fail the device or cause degradation. Robust connections with strong interfacial strength and low interfacial impedance are highly desired in all kinds of flexible devices, especially when they require stretchability. Here, a new strategy of employing homogeneity is proposed to facilely achieve robust connection without introducing a third-party interlayer. The key to this strategy is implementing different functions in the same component materials, and in this work, this strategy is demonstrated by exploring the uniformity of carbon nanotube (CNT) in thermoplastic polyurethane (TPU) elastomer. Tuning the uniformity of CNT in TPU elastomer, two kinds of CNT-TPU composites (CTCs) are fabricated. They present contrasting properties of conductivity (281 folds), Young's modulus (7.1 folds), and strain sensitivity (15.7 folds) with the same weight fraction of CNT (15 wt %), and thus they can respectively act as strain sensor and interconnector in all-CNT-based stretchable strain monitoring electronics. The interlocking effect caused by spontaneous entanglement of surface polymer chains and the reconstruction of percolation network at the interface during drying confer the connection with robustness. The practical value of this strategy has been exemplified by the fabrication of a robust epidermis device via additive manufacturing. This epidermis device is patterned in a fractal motif for conformal contact and can sensitively monitor body motions and radial artery pulse.

PurposeThis study aims to investigate the heat transfer mechanism of the uniforms used by people working in hot, humid and windy environments. Furthermore, the effectiveness of an opening structure added to the armpit of the uniforms in improving thermal comfort was comparatively examined.Design/methodology/approachA set of uniforms was tested with the opening at the armpit alternatively zipped or unzipped. Thermal manikin and human tests were performed in a climatic chamber simulating the specific environmental conditions, including wind speeds at four levels (0.15, 0.5, 2, 4 m/s) and relative humidities at two levels (50 and 85%). Static and dynamic thermal insulations of clothing (IT) were examined by the thermal manikin tests. The human bodies' thermal responses, including heart rates (HR), eardrum temperatures (Te), skin temperatures (Tsk) and subjective perceptions, were given by the human tests.FindingsSpecial mechanisms of heat transfer in the specific uniforms used in tropical monsoon climates were revealed. Reductions on IT were caused by the movement of the human body and the environmental wind, and the empirical equations would underestimate this reduction. The opening at the armpit was able to prompt more heat transfer under dynamic condition, with reducing the IT by 11.8%, lowering the mean Tsk by 0.92°C, and significantly improving the subjective perceptions (p e by 0.32°C.Originality/valueThis study managed to improve the thermal performance of uniforms for workers under unforgiving conditions. The evaluation and design methods introduced by this study provided practical guidance for similar products with strict dress codes and cost control requirements based on the findings from thorough product tests and analysis.

The thermo-physiological human simulator has been used in many regions for estimating thermal behavior of the locals. The applicability of the human simulator to populations from different regions is, however, questioned due to its lack of consideration for the ethnic diversities in thermoregulation. This study checked the potential of improving the applicability of the Newton human simulator, one of the most popular simulators, by correcting its local set point skin temperatures according to the target population (Chinese as an example). First, new set point skin temperatures were obtained by conducting tests with 101 Chinese under a thermal neutral condition. Then, simulator tests using the original and new set point skin temperatures were conducted separately for evaluating thermal responses of the Chinese under non-neutral conditions. The evaluated skin and core temperatures by the simulators were compared with those measured from the real human tests. It demonstrated that the evaluated skin temperatures are positively related with the set point skin temperatures of the simulator. Adjusting set point skin temperatures according to the Chinese improved the prediction performance of the local skin temperatures, with the root-mean-square-deviation being reduced for over 50% of the body segments. The proposed idea of correcting local set point skin temperatures would contribute to evaluating the thermal interaction between human body and its surroundings with a higher accuracy.

Long-term high-fat diet (HFD) destroys the intestinal mucosal barrier by damaging intestinal stem cells (ISCs). A HFD can increase the concentration of intestinal deoxycholic acid (DCA) and decrease the secretion of interleukin-22 (IL-22), which plays an important role in the proliferation, repair and regeneration of ISCs. We hypothesized that increased level of intestinal DCA induced by a HFD leads to ISC dysfunction by reducing the IL-22 levels in intestinal tissues. In this study, 2 weeks of a DCA diet or a HFD damaged ileal ISC and its proliferation and differentiation, resulting in a decrease in Paneth cells and goblet cells. Importantly, 2 weeks of a DCA diet or a HFD also reduced ileal IL-22 concentration, accompanied by a decreased number of group 3 innate lymphoid cells in ileal mucosa, which produce IL-22 after intestinal injury. Concurrent feeding with bile acid binder cholestyramine prevented all these changes induced by a HFD. In addition, in vitro study further confirmed that exogenous IL-22 reversed the decline in the proliferation and differentiation of ileal ISCs induced by DCA stimulation. Collectively, these results revealed that the decrease in intestinal IL-22 induced by DCA may be a novel mechanism by which HFD damages ISCs. The administration of IL-22 or a bile acid binder may provide novel therapeutic targets for the metabolic syndrome caused by a HFD.

A solution to improve the FAST feature point detection algorithm susceptible to image noise interference is proposed. Eight directions are derived from the selected point to solve the gray level mutations in these eight directions, and based on this, it is judged whether the point is a feature point. And take the maximum value suppression for the dense area of feature points, and solve the maximum value of the sum of gray changes in all directions as the judgment condition to screen the feature points. A new feature point matching scheme is proposed, where the Hamming distance between feature points within the target image is derived by the BruteForce algorithm. If the Hamming distance between the first few target points and the original feature point is less than a certain threshold, it will be substituted into the original image to solve the problem. The Hamming distance between the feature points of the original image is selected as the correct matching point. Finally, the principle of region growth is introduced to the MC algorithm, which saves the amount of calculation and improves the generation accuracy.

Dynamical diagnosis of damage evolution is essential to promote the pavement performance of asphalt materials and prolong their service life. As a non-destructive method, acoustic emission (AE) can be used to assess the degree of deformation or cracking of stressed materials by detecting the energy release from damage points. The objective of the study was to explore the continuous damage evolution behavior of asphalt mixtures by evaluating the variation characteristics of AE parameters and waveforms. Firstly, the three-point bending tests and AE tests were simultaneously conducted on asphalt mixture beams, and AE behaviors associated with the failure process were investigated. Secondly, considering the impact of material heterogeneity on AE transmission, wavelet transform was utilized to qualitatively determine the relationship between wavelet coefficient and damage degree of asphalt mixtures. Lastly, the fractal theory was applied to quantitatively explore the scale-invariance of AE process and the AE mutation of damage process. The results show that the accumulation of AE energy and AE count could reflect the dynamical failure process of asphalt mixtures under different loading rates. The effect of sampling frequency could be presented by time-scale characteristics of AE waveforms. The fracture characteristics of asphalt mixtures could be reflected by amplitude and energy distribution of cumulative AE energy and AE waveforms. The fractal result of AE energy is relatively stable in revealing the flexural failure characteristics of asphalt mixtures. The mutational rise of the waveform fractal dimension from the minimum value is related to the critical fracture condition of asphalt mixtures.

Recently, with the popularity of smartphones and other GPS embedded devices, location-based service applications are being rapidly developed. In addition, individual privacy protection is also receiving increasing attention. Currently, most studies assume that individual location records are independent. However, the records are mostly interrelated in the real world. If the information is protected without considering the location-correlated information between users, an attacker can use a background knowledge attack to obtain the user’s private information. Therefore, this paper proposes a method to protect multiuser location-correlated information under a strict privacy budget. First, a method for group movement analysis based on adaptive time segmentation is proposed in this paper. In addition, based on the time dimension, time-continuous hotspot areas are constructed by adaptively segmenting and merging the stay areas, which are established for subsequent location-correlated privacy protection. Second, a data publishing mechanism is proposed to resist inferred attacks and to adaptively protect user-correlated location information. In addition, this paper also proposes the individual user correlation sensitivity concept and extends differential privacy by building an individual sensitivity matrix to correct noise. The experiments on real datasets show that under the same conditions, compared with the existing methods, the heat value of the hotspot areas formed by the method is increased by 10.11% under the same time slice length. In addition, the method reduces the similarity of 26.98% of group users.

The relationship between precipitation types and meteorological factors was surveyed based on the effect analysis of main meteorological parameters on asphalt pavement surface icing conditions and prediction analysis model of asphalt pavement temperature was established. This study aims to determine the correlation between icy pavement and meteorological factors and implement an accurate prediction of the icing condition of pavement. Considering the road slipperiness criterion presented by Norrman, a discriminative standard of icing condition of asphalt pavement surface in the central area of Zhejiang Province was proposed. Based on the above analysis results, a prediction model of pavement surface icing condition involved in asphalt pavement and ambient temperatures under the condition of different precipitation types was constructed by using support vector machine (SVM) method. Results demonstrate that (1) the distribution characteristics of daily mean air temperature, daily mean pavement temperature, daily average wind speed, and average daily rainfall have remarkable differences under the condition of different precipitation types, wherein the variation features of daily mean air temperature and daily mean pavement temperature are obvious; (2) the indirect prediction of precipitation type and pavement surface temperature could be accomplished in terms of meteorological monitoring data; (3) the influence of pavement surface icing conditions on driving safety is lower than that of rainwater freezing on a cold surface, melting snow at air temperature above 0℃, and melting snow at air temperature below 0℃; and (4) the SVM-based prediction model of pavement surface icing condition has an accurate analysis result with misreporting rate below 6%. The generalization ability of the proposed model is good and fully demonstrates the application prospects of SVM in the pavement weather prediction field. This study can provide theoretical and technical support for real-time warning about icy asphalt pavements in winter.

Human thermoregulation models, particularly the Fiala model, are well accepted for the prediction of thermoregulatory responses and the assessment of clothing and building systems with regard to human thermal comfort. However, the convective heat transfer coefficients (hc), used for the heat transfer calculations, were obtained from measurements with a thermal manikin with poor body resolution from decades ago, and they were not distinguished between body postures. In this study, the overall and local hc of the human body in both standing and seated postures were evaluated by CFD simulations and implemented in the Fiala model to investigate the resultant influence on the predicted thermoregulatory responses by comparing the predictions with measurements of 14 human exposures. It was found that the original hc used in the Fiala model was similar to the simulated hc of the standing body, but higher than that of the seated body at most body parts. In 64% of the investigated human exposures, the root-mean-square-deviation of the skin temperature predicted by the Fiala model with the simulated hc was lower than that achieved with the original hc, indicating an improvement of the accuracy of the Fiala model. Additionally, the higher hc of the standing body resulted in a lower mean skin temperature by up to 1.5 °C when compared to the seated body in the environment of 10 °C and 2.5 m/s. This emphasises the necessity of ensuring the accuracy of the hc in the thermoregulation model in order to improve its validity for specific investigated conditions.

Long-term high-fat feeding (HF) induces intestinal mucosal barrier damage. However, the mechanism for this remains unclear. HF can elevate the intestinal and circulating bile acid (BA) levels, especially deoxycholic acid (DCA). We hypothesize that BAs elevated by HF regulate intestinal stem cell (ISC) function, which may contribute to mucosal barrier injury in the ileum of mice. In this study, we showed that 2 weeks of HF resulted in a shortening of intestinal villi and a decrease in the tight junction (TJ) protein occludin in the ileum of mice, accompanied by an increase in circulating BA levels. Importantly, 2 weeks of HF also reduced ileal ISCs and goblet cells and decreased the proliferation function of ISCs and their ability to differentiate into goblet cells. Endoplasmic reticulum (ER) stress was found to be involved in the process of ISC damage. All these alterations were reversed by cofeeding with the bile acid binder cholestyramine. In addition, the in vitro studies also confirmed a cytotoxic effect of DCA at a high concentration on ISCs and goblet cells. In conclusion, these data suggested that high levels of BAs induced by HF could impair ISC function by triggering ER stress, resulting in the disruption of the intestinal mucosal barrier.

Rationale Spasmolytic polypeptide-expressing metaplasia (SPEM) is an important risk factor for the occurrence of gastric cancer. It may be driven by a chronic inflammatory environment in which macrophage is involved. Studies have shown that intestinal metaplasia may originate from SPEM, and bile acid-induced chronic inflammation plays an important role in the process of intestinal metaplasia. However, whether bile acids are involved in the development of SPEM and the specific mechanism are unclear. Meanwhile, macrophages are known to be involved in inflammation regulation by releasing various factors, including exosomes. In this study, we hypothesized that the exosomes released from macrophages stimulated by deoxycholic acid participated in the development of SPME. Methods In vivo, mice were gavaged with deoxycholic acid for 4 weeks, and gastric tissues were harvested. In vitro, deoxycholic acid-induced macrophage-derived exosomes were isolated by ultracentrifugation and cocultured with the gastric organoids of mice. Immunofluorescence staining and quantitative real-time PCR were used to analyze markers of macrophages and SPEM. Results In vivo, after 4 weeks of deoxycholic acid intragastric administration, macrophage markers (F4/80) and SPEM markers (TFF2 and GSII lectin) were increased in from treated mice compared with those from normal control mice. In vitro, macrophage-derived exosomes labeled with PKH67 were internalized by gastric organoids. Deoxycholic acid-induced macrophage-derived exosomes increased the expression of SPEM markers (TFF2 and GSII lectin) in gastric organoids compared to exosomes derived from macrophages without deoxycholic acid stimulation. Conclusion Macrophage-derived exosomes may be a novel mechanism by which deoxycholic acid promotes SPEM.

The objective of the study was to numerically investigate the effect of thermal regulation performance provided by the winter school uniforms varying in wearing methods on thermal responses. A model of human thermal regulation was used to predict the human physiological responses while sedentary in an indoor environment and exercising in an outdoor environment, and further validated against measured data in human trials. TSENS and UCB comfort models were coupled to the thermal regulation model for predicting human thermal sensation. The predictions were then compared with the subjective responses to surveys. The results showed that the thermal regulation model coupled to UCB comfort model presented the potential for providing a means for reasonably accurate prediction of the thermal sensation in both indoor and outdoor environments. Based on the presented model, it was demonstrated that the difference of mean skin temperatures caused by the different wearing methods of school uniforms ranged from 1.26 to 1.99 °C. Thus, the designs on thermal regulation performance provided by the wearing methods of school uniform were extremely important for students to improve their thermal comfort while switching between the indoor and outdoor environments.

To understand the effectiveness of some garment adjustment designs for high school uniform in winter, manikin tests and subjective wear trials were carried out. Five series of school uniform ensembles were involved in the experiments. They were further collocated into 17 ensemble configurations with detachable designs (ensembles A and B) and opening structures (ensembles C, D, and E). As manikin test results showed, the thermal insulation of ensembles A, B and C varied most significantly due to their adjustment design. The possible thermal insulation regulation levels were approximately 68% and 80% for ensembles A and B, and 60% and 90% for ensemble C. Two human trials that simulated students’ daily movements between indoor and outdoor classes were conducted with ensemble A. Two climate chambers were used at the same time for indoor and outdoor environment simulation. In Case X, where ensemble A was assumed to be non-detachable, skin temperatures that were 0.6℃ lower were finally observed compared to Case Y, where ensemble A was detachable. Moreover, significantly ( p

Cholesterol overloading and bile acid metabolic disorders play an important role in the onset of cholesterol gallstone (CGS). Short-chain fatty acids (SCFAs) can regulate bile acid metabolism by modulating the gut microbiota. However, the role and mechanism by which sodium butyrate (NaB) targets bile acids to attenuate CGS are still unknown. In this study, continuous administration of 12 mg/day for 8 weeks was decreased the incidence of gallstones induced by lithogenic diet (LD) from 100% to 25%. NaB modulated SCFAs and improved the gut microbiota. The remodeling of the gut microbiota changed the bile acid compositions and decreased cecal tauro-α-muricholic acid (T-α-MCA) and tauro-β-muricholic acid (T-β-MCA) which are effective farnesoid X receptor (FXR) antagonists. The quantitative real-time PCR examination showed that NaB significantly increased levels of ileal Fxr, fibroblast growth factor-15 (Fgf-15) and small heterodimer partner (Shp) mRNA and subsequently inhibited bile acid synthesis. In addition, NaB enhanced bile acid excretion by increasing the levels of hepatic multidrug resistance protein 2 (Mdr2) and bile salt export pump (Bsep) mRNA, and it enhanced bile acid reabsorption in the intestine by increasing the levels of ileal bile acid transporter (Ibat) mRNA. In addition, NaB reduced the absorption of cholesterol in the intestine and inhibited the excretion of cholesterol in the liver, which reduced the cholesterol concentration in serum and bile. Furthermore, the protective effects of NaB administration were abolished by FXR antagonists. Taken together, our results suggest that NaB mitigates CGS by modulating the gut microbiota to regulate the FXR-FGF-15/SHP signaling pathway.

Natural dermal armor has superior protective performance and flexibility for effectively protecting flexible objects. Limited by the complex microstructure of natural scales, the scales of common bionic armors are mostly solid flat scales, which will have a certain impact on the quality and protective performance of the armor, and they are not suitable for protecting flexible objects with a curved surface out of consideration for conformality and performance. Based on the Miura pattern with single-degree-of-freedom, this paper designs an arc-scale that can be conformal to the curved surface, and proposes an arc-armor inspired by fish scales. The experiments and numerical simulations have proved that the introduction of the origami structure design can induce a stable failure mode of the arc-scale. The origami-based arc-armor has the advantages of low peak load, long effective stroke, and small fluctuation, which greatly improves the protection performance of the armor. And based on the failure mode of the arc-scale, the second-level structure is proposed to further optimize the energy absorption characteristics of the arc-scale, which contributes to reducing the peak load of the scales under medium- and high-velocity impacts. Under high-velocity impact, the denser the distribution of cells inside the scales, the higher the energy absorption efficiency of the arc-scales, which provides certain guidance for the design and application of the arc-armor. We have obtained an arc-armor with excellent energy absorption characteristics that can be reverse-designed according to the target shape. And such structures can find a wide range application in the protection of flexible electronics, human bodies, and other flexible objects that require light weight and flexibility.

The fractures in asphalt materials evolving from microcracks directly affect the performance of asphalt pavements. Acoustic Emission (AE) technique plays a crucial role in dynamically monitoring the internal structural changes of stressed materials. This study attempted to characterize the fracture mechanism of asphalt mixtures by identifying the characteristics of recoded AE data. Firstly, the three-point bending tests and AE tests were simultaneously conducted to investigate the damage evolution process of asphalt mixtures through the time characteristics of AE parameters. Secondly, the cusp catastrophe model based on AE energy rate was employed to explore the mutational characteristics of AE process and to evaluate the damage state of asphalt mixtures. Finally, the k-means method was applied to distinguish the patterns of AE signals associating with the specific damage behaviors of asphalt mixtures during the flexural failure process. The results show that abrupt change of AE energy rate and cumulative AE energy could reflect the evolutionary characteristics of damage in asphalt mixtures. The mutational analysis of AE energy rate reveals that the damage state of asphalt mixtures subjected to the continuous external forces would change between instability and stability, which could be served as a complementary approach for further understanding the periodic variation characteristics of damage evolution process based on cumulative AE energy. The k-means method could effectively classify the recorded AE signals of asphalt mixtures in three-point bending tests into three distinctive clusters. The potential mechanisms for the clustered signals corresponding to different damage behaviors of asphalt mixtures could be characterized by the parametric characteristics and the wavelet power spectrum of AE signals.

To study the influence of the coexistence condition of acidic and alkalic additives on the mechanical performance of stabilized clay based on the processes for obtaining the basic physical parameters of soil and analyzing the stabilization mechanism of ionic and alkalic soil stabilizers, an experiment on the mechanical behavior characteristics of stabilized clay was performed using different types of ionic and alkalic stabilizers through a series of laboratory tests. The following results are obtained. (1) Typical soil is low liquid limit clay, and the ionic stabilizer with an optimal content of 0.014% mass ratio to dry soil exhibits strong acidity. (2) As a result of its unique molecular structure, the double electric-combined water film becomes thin rapidly during compaction molding, in which the compactness of clay particle structure increases. (3) The 7-day unconfined compressive strength can be improved with different contents of the ionic stabilizer. (4) Except for the high lime soil mixture, the compaction degree of soil exerts a pronounced effect on the stabilization performance of an ionic stabilizer and the least compaction degree should be over 96%. (5) The unconfined compressive strength, indirect tensile strength, and freeze-thaw performance of the acid-alkali-stabilized soil demonstrate a gradually increasing tendency with an increase in curing time, however, the evolution characteristic of strength exhibits an advantageous superposition threshold value when compared to the alkali-stabilized clay. The neutralization reaction and oil membrane of soil particles will inhibit the later reaction processes of carbonation, pozzolanic, and hydration of lime-|cement-stabilized soil.

As an important factor in indoor human thermal comfort, the wind is investigated in the present study using a fully validated human body-environment interface model based on CFD technology. The three parameters of air speed (va, 0.5–2 m/s), turbulence intensity (TI, 5%–40%) and wind direction (0°–180°) were simulated to study their influence on the convective heat transfer coefficient (hc) at the surface of the human body. It was found that va influenced the value of hc more than TI. The influence of TI on hc reached a steady level when va was above 1.5 m/s; for example the greatest rate of change of hc at the head remained at 52% as the TI was increased from 5% to 40%. The wind direction had a noticeable influence on the overall hc when the va was above 0.5 m/s. A 90° wind (i.e. from the right side) gave a value of hc that was about 20% lower than wind from other directions, and led to an asymmetrical distribution of hc over the body surface. Locally, the wind direction did not influence hc at the head and feet, and influenced the central segments more than the limbs. Two regression equations for the correlations between hc and va, TI and wind direction were also generated and validated for continuous evaluation of hc. The resulting database of values for hc can be used in combination with the human thermoregulation models for thermal response prediction in built spaces with increased air speed.

The crosstalk between macrophages and gastric epithelial cells has emerged as a player in chronic inflammation during intestinal metaplasia. However, the role of bile acid on this modulation remains to be studied. We hypothesized that deoxycholic acid-induced macrophages secreted exosomes to mediate intercellular communication and promoted intestinal metaplasia in human gastric epithelial cells (GES-1 cells). Macrophage-derived exosomes (M-Exos) and deoxycholic acid-induced macrophage-derived exosomes (D-Exos) were isolated by ultracentrifugation. EdU staining and CCK-8 assay were utilized to evaluate the effects of exosomes on the proliferation of GES-1 cells. Intestinal metaplasia was assessed by the expression of caudal-related homeobox transcription factor 2 (CDX2) at both mRNA and protein level. MicroRNA sequencing revealed the microRNA (miRNA) expression profiles of M-Exos and D-Exos. The role of a specific miRNA and mRNA was analyzed by using miRNA mimics, miRNA inhibitors and siRNAs. D-Exos promoted the expression of CDX2 and suppressed the proliferation of GES-1 cells, compared to M-Exos. The miRNA profiles and quantitative real-time PCR examination showed D-Exos enriched a higher level of hsa-miR-30a-5p than M-Exos. Overexpressed has-miR-30a-5p increased CDX2 expression and inhibited the proliferation in GES-1 cells via targeted Forkhead Box D1 (FOXD1), a potential regulatory factor in the process of intestinal metaplasia. D-Exos may promote intestinal metaplasia and suppress proliferation of GES-1 cells via hsa-miR-30a-5p targeting FOXD1, which may be involved in the action mechanism of bile acid on gastric mucosa.

As a typical mode of modern transportation, high-speed rail (HSR) plays a key role in the formation and development of today's regional spatial pattern. Based on the panel data of 2009, 2012, 2015 and 2018, Beijing-Tianjin-Hebei Urban Agglomeration is taken as the research object and the social network analysis method is used by this research to explore the evolution of urban agglomeration spatial structure under the impact of HSR construction. The results show that: Firstly, HSR construction increases the average network density of urban agglomeration by 0.0487, which promotes the spatial connection density of urban agglomeration in a positive way. Secondly, HSR can improve the point centrality of moderately developed cities by 0.87, reduce the spatial connection of urban agglomeration’ dependence on core cities, and improve the urban agglomeration’ stability of spatial structure. Thirdly, HSR can make more cities enter the core subgroup faster, and improve the speed of urban agglomeration evolution to the optimized state. Based on this, the following suggestions are put forward: first, cities without HSR should strengthen urban construction in order to achieve interconnection with cities with HSR as soon as possible. Second, HSR construction should be taken as an opportunity to cultivate new regional hub cities. Third, the transportation planning department should strive to improve the HSR construction level of the peripheral cities so that they can share the effect of HSR construction.