المؤلفون: Yongwang Lin, Xiaoyue Liang, Zhengyi Li, Tao Gong, Biao Ren, Yuqing Li, Xian Peng

المصدر: International Journal of Oral Science, Vol 16, Iss 1, Pp 1-11 (2024)

مصطلحات موضوعية: Dentistry, RK1-715

الوصف: Abstract The human oral microbiome harbors one of the most diverse microbial communities in the human body, playing critical roles in oral and systemic health. Recent technological innovations are propelling the characterization and manipulation of oral microbiota. High-throughput sequencing enables comprehensive taxonomic and functional profiling of oral microbiomes. New long-read platforms improve genome assembly from complex samples. Single-cell genomics provides insights into uncultured taxa. Advanced imaging modalities including fluorescence, mass spectrometry, and Raman spectroscopy have enabled the visualization of the spatial organization and interactions of oral microbes with increasing resolution. Fluorescence techniques link phylogenetic identity with localization. Mass spectrometry imaging reveals metabolic niches and activities while Raman spectroscopy generates rapid biomolecular fingerprints for classification. Culturomics facilitates the isolation and cultivation of novel fastidious oral taxa using high-throughput approaches. Ongoing integration of these technologies holds the promise of transforming our understanding of oral microbiome assembly, gene expression, metabolites, microenvironments, virulence mechanisms, and microbe-host interfaces in the context of health and disease. However, significant knowledge gaps persist regarding community origins, developmental trajectories, homeostasis versus dysbiosis triggers, functional biomarkers, and strategies to deliberately reshape the oral microbiome for therapeutic benefit. The convergence of sequencing, imaging, cultureomics, synthetic systems, and biomimetic models will provide unprecedented insights into the oral microbiome and offer opportunities to predict, prevent, diagnose, and treat associated oral diseases.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2049-3169Test

الوصول الحر: https://doaj.org/article/60f4b1aceb7449259a4da9ab9ab001b6Test

المؤلفون: Zhiying Zhang, Zhiyan Zhou, Jiaxin Liu, Liwei Zheng, Xian Peng, Lei Zhao, Xin Zheng, Xin Xu

المصدر: Frontiers in Immunology, Vol 15 (2024)

مصطلحات موضوعية: taste/taste physiology, periodontal disease(s), fibroblast(s), chemokines, bone loss, infectious disease(s), Immunologic diseases. Allergy, RC581-607

الوصف: IntroductionCells expressing taste signaling elements in non-gustatory tissues have been described as solitary chemosensory cells (SCCs) or tuft cells. These “taste-like” cells play a critical role in the maintenance of tissue homeostasis. Although the expression of SCC markers and taste signaling constituents has been identified in mouse gingivae, their role in periodontal homeostasis is still unclear. MethodsPublic RNA sequencing datasets were re-analyzed and further validated with RT-PCR/qRT-PCR and immunofluorescent staining to explore the expression of TAS2Rs and downstream signaling constituents in mouse gingival fibroblasts (MGFs). The specific action of salicin on MGFs via Tas2r143 was validated with RNA silence, heterologous expression of taste receptor/Gα-gustducin and calcium imaging. The anti-inflammatory effects of salicin against LPS-induced MGFs were investigated in cell cultures, and were further validated with a ligature-induced periodontitis mouse model using Ga-gustducin-null (Gnat3−/−) mice. ResultsThe expression of Tas2r143, Gnat3, Plcb2, and TrpM5 was detected in MGFs. Moreover, salicin could activate Tas2r143, elicited taste signaling and thus inhibited LPS-induced chemokines expression (CXCL1, CXCL2, and CXCL5) in MGFs. Consistently, salicin-treatment inhibited periodontal bone loss, inflammatory/chemotactic factors expression, and neutrophil infiltration in periodontitis mice, while these effects were abolished in Gnat3−/− mice. DiscussionGingival fibroblasts play a critical role in the maintenance of periodontal homeostasis via “SCC-like” activity. Salicin can activate Tas2r143-mediated bitter taste signaling and thus alleviate periodontitis in mouse, indicating a promising approach to the resolution of periodontal inflammation via stimulating the “SCC-like” function of gingival fibroblasts.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fimmu.2024.1374900/fullTest; https://doaj.org/toc/1664-3224Test

الوصول الحر: https://doaj.org/article/852c3874ba2e40b0a975b0415d9c19d5Test

المؤلفون: Liehui Zhang, Cheng Cao, Shaomu Wen, Yulong Zhao, Xian Peng, Jianfa Wu

المصدر: Natural Gas Industry B, Vol 10, Iss 4, Pp 383-392 (2023)

مصطلحات موضوعية: Carbon peak, Carbon neutrality, Natural gas, CO2-EGR, CO2 sequestration, Energy security, Gas industry, TP751-762

الوصف: In September 2020, the Chinese government proposed the goals to reach carbon dioxide emissions peak by 2030 and achieve carbon neutrality by 2060 (“two-carbon goals”). This brings opportunities to the development and application of CO2-enhanced gas recovery (CO2-EGR) in China. To obtain an overall understanding of the development of CO2-EGR under the two-carbon goals, this paper analyzes the significance, potential, status quo and challenges of CO2-EGR, and makes suggestions on the development of CO2-EGR in China. The research results are obtained as follows. First, the development of CO2-EGR plays a crucial role in ensuring China's energy security, accelerating the construction of the clean energy system to promote energy transition and realizing the two-carbon goals as early as possible. Second, China should clarify a path for CO2-EGR development, build a spatial layout of CO2-EGR, and promote digital inclusion in CO2-EGR, enhance the emission reduction role of CO2-EGR in the multi-energy complementary system, boost large scale application of renewable energy and deep decarbonization in the traditional coal industry, which is difficult to reduce carbon emissions. Third, China should draw lessons from European and American tax credit and innovation funds policies to accelerate the construction of a CO2-EGR policy support system. Fourth, China should carry out research on key CO2-EGR technologies to accelerate the construction of a CO2-EGR methodology and standard system and promote rapid and standardized development of the CO2-EGR industry. It is suggested to establish a CO2-EGR demonstration area in the Sichuan Basin and popularize it across China, so as to improve comprehensive economic benefits through the establishment of large-scale industrial clusters. It is concluded that the two-carbon goals bring opportunities to the development of CO2-EGR in China, which will promote gas production and demonstration of CO2 sequestration in gas reservoirs and have positive significance in ensuring energy security and realizing carbon peak and carbon neutrality in China.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2352854023000499Test; https://doaj.org/toc/2352-8540Test

الوصول الحر: https://doaj.org/article/308bdbab724849349d34ed0abdf5ef27Test

المؤلفون: Yuxiang Zhang, Haijun Yan, Shenglai Yang, Hui Deng, Xian Peng, Zhangxing Chen

المصدر: Journal of Natural Gas Geoscience, Vol 8, Iss 2, Pp 153-167 (2023)

مصطلحات موضوعية: Ultra-deep carbonate gas reservoir, Temperature, Gas single-phase seepage, Gas-water two-phase seepage, Gas-water physical properties, Gas industry, TP751-762

الوصف: Ultra-deep carbonate gas reservoirs are buried at great depths and have high temperatures, and the impact of high temperature on the seepage capacity of multi-type reservoirs is still unclear. The study selected cores from the fourth member of Dengying Formation in the Gaoshiti-Moxi area to measure the gas single-phase permeability of rock samples during the heating and cooling process, as well as the gas-water interfacial tension and gas-water two-phase relative permeability at different temperatures. This allowed researchers to obtain the effect of temperature on the seepage capacity of multi-type ultra-deep carbonate gas reservoir. The research results show that within the range of 20–120 °C, with the change of temperature, the gas single-phase seepage capacity of different types of reservoir rock samples changes as a power function. The decrease in gas-phase permeability during the heating process is jointly affected by the increase in gas viscosity, the expansion of dolomite crystals, and the migration of rock particles after embrittlement. After one heating and cooling process, fractured-cavity type rock samples had the highest irreversible degree of permeability at 82.52%, due to the development of micro-fractures, followed by 27.63% for pore type due to the development of small pores and throats, and the lowest was 9.46% for pore-cavity type. Fractured-cavity rock samples are temperature-sensitive, while pore-type and pore-cavity-type rock samples are temperature-resistant. The upper-temperature limit of the target multi-type gas reservoir is concentrated around 46–50 °C. The temperature increase mainly improves the gas-displacing water efficiency and gas-water two-phase seepage capacity by reducing the water-gas viscosity ratio, which is about 1/3 of the normal temperature at the formation temperature. The gas-water phase permeability curves of multi-type reservoirs under high-temperature conditions can better represent the two-phase seepage characteristics of actual formations. The effect of temperature on the seepage capacity of multi-type ultra-deep carbonate gas reservoirs can provide a theoretical basis for the efficient development of such gas reservoirs.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2468256X23000160Test; https://doaj.org/toc/2468-256XTest

الوصول الحر: https://doaj.org/article/1c742bc8e1ac4990a8aa703f0ca89a4eTest

المؤلفون: Dong Hui, Yan Zhang, Yong Hu, Xian Peng, Longxin Li, Zihan Zhao, Xixiang Liu, Tao Li, Yi Pan

المصدر: Energy Science & Engineering, Vol 11, Iss 4, Pp 1352-1369 (2023)

مصطلحات موضوعية: connectivity, OM pores, pore structure, pyrobitumen, shale gas, spatial distribution, Technology, Science

الوصف: Abstract Knowledge of shale pore structure characteristics is crucial to understand gas storage and seepage mechanisms. Organic matter (OM) pores are considered the most important pore type in shale, and one of the currently significant research questions focuses on the spatial distribution and connectivity of OM pores. To answer this question, typical OM‐rich siliceous shale samples from the Lower Silurian Longmaxi Formation were comprehensively investigated using focused ion beam scanning electron microscopy. A three‐dimensional model of the OM‐rich region of interest was segmented and reconstructed based on numerous two‐dimensional slices. The types of OM were found to control the development of organic pores, and OM pores including honeycomb‐shaped pores, spongy‐shaped pores, and slit‐like irregular pores are mainly formed in the pyrobitumen. The pore structure parameters of the OM‐rich ROI revealed that the pore size distribution of honeycomb‐shaped OM pores formed in the pyrobitumen was mainly distributed in the range of 10–50 and 80–100 nm, while the throat equivalent diameter distribution demonstrated a unimodal curve with the main peak located at approximately 30 nm. Pore connectivity analysis further indicated that pyrobitumen also contained several isolated nano‐pores, and pores with diameters smaller than 40 nm were poorly connected. Furthermore, permeability simulation revealed clear discrepancies in different directions owing to the heterogeneity of the OM pores. These findings provide experimental evidence for the assessment of shale gas resources and their development potential.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2050-0505Test

الوصول الحر: https://doaj.org/article/0abda959151445da918053f3eecb33c4Test

المؤلفون: Dong Hui, Longxin Li, Yan Zhang, Xian Peng, Tao Li, Changqing Jia, Yi Pan

المصدر: Frontiers in Energy Research, Vol 11 (2023)

مصطلحات موضوعية: shale, shale gas, clay minerals, CO2 storage, molecular simulation, General Works

الوصف: Knowledge of the interaction mechanisms between shale and CH4/CO2 is crucial for the implementation of CO2 sequestration with enhanced CH4 recovery (CS-EGR) in shale reservoir. As one of the main constituents of shale, clay minerals can profoundly affect the storage capacity of gases in nanopores. In this paper, the adsorption behaviors of both CO2 and CH4 on montmorillonite, illite as well as kaolinite under dry condition are investigated by Grand Canonical Monte Carlo (GCMC) simulation. The results exhibit that the maximum adsorption capacity of single-component CH4 and CO2 is associated with the types of clay crystals. Specifically, the montmorillonite has the strongest adsorption capacity for CO2, followed by illite and kaolinite, while the sequence in maximum adsorption capacity of CH4 is predicted in the order of kaolinite > montmorillonite > illite. These discrepancies are closely related to the characteristics of adsorbate molecules as well as the different structures of clay crystals. Meanwhile, the maximum adsorption capacity of CH4 in studied clay minerals gradually decreases as pore size increases, while nanopores with 2-nm basal spacing demonstrate the highest adsorption capacity for CO2. In addition, it is observed that the studied clay minerals tend to preferentially adsorb CO2 rather than CH4 during binary gas mixtures simulation. The selectivity of CH4/CO2 mixtures in montmorillonite and kaolinite exhibits various performances as the adsorption pressure increases, with the selectivity in montmorillonite being the largest, especially at low pressure. The cation exchange significantly enhances the electrostatic interaction with CO2 molecules, leading to a higher loading of CO2 as well as larger value of selectivity. These findings can provide basis and guidance for the CS-EGR project in shale reservoirs.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fenrg.2023.1231338/fullTest; https://doaj.org/toc/2296-598XTest

الوصول الحر: https://doaj.org/article/5bcc4f7dbcbf49af8bfd83c546bd6da0Test

المؤلفون: Zheng Wang, Ge Yang, Xuedong Zhou, Xian Peng, Mingyun Li, Miaomiao Zhang, Dong Lu, Deqin Yang, Lei Cheng, Biao Ren

المصدر: Microbiology Spectrum, Vol 11, Iss 4 (2023)

مصطلحات موضوعية: heavy ion, Streptococcus mutans, oral microbiota, Microbiology, QR1-502

الوصف: ABSTRACT Radiation caries is one of the most common complications of head and neck radiotherapy. A shift in the oral microbiota is the main factor of radiation caries. A new form of biosafe radiation, heavy ion radiation, is increasingly being applied in clinical treatment due to its superior depth-dose distribution and biological effects. However, how heavy ion radiation directly impacts the oral microbiota and the progress of radiation caries are unknown. Here, unstimulated saliva samples from both healthy and caries volunteers and caries-related bacteria were directly exposed to therapeutic doses of heavy ion radiation to determine the effects of radiation on oral microbiota composition and bacterial cariogenicity. Heavy ion radiation significantly decreased the richness and diversity of oral microbiota from both healthy and caries volunteers, and a higher percentage of Streptococcus was detected in radiation groups. In addition, heavy ion radiation significantly enhanced the cariogenicity of saliva-derived biofilms, including the ratios of the genus Streptococcus and biofilm formation. In the Streptococcus mutans-Streptococcus sanguinis dual-species biofilms, heavy ion radiation increased the ratio of S. mutans. Next, S. mutans was directly exposed to heavy ions, and the radiation significantly upregulated the gtfC and gtfD cariogenic virulence genes to enhance the biofilm formation and exopolysaccharides synthesis of S. mutans. Our study demonstrated, for the first time, that direct exposure to heavy ion radiation can disrupt the oral microbial diversity and balance of dual-species biofilms by increasing the virulence of S. mutans, increasing its cariogenicity, indicating a potential correlation between heavy ions and radiation caries. IMPORTANCE The oral microbiome is crucial to understanding the pathogenesis of radiation caries. Although heavy ion radiation has been used to treat head and neck cancers in some proton therapy centers, its correlation with dental caries, especially its direct effects on the oral microbiome and cariogenic pathogens, has not been reported previously. Here, we showed that the heavy ion radiation directly shifted the oral microbiota from a balanced state to a caries-associated state by increasing the cariogenic virulence of S. mutans. Our study highlighted the direct effect of heavy ion radiation on oral microbiota and the cariogenicity of oral microbes for the first time.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2165-0497Test

الوصول الحر: https://doaj.org/article/526d1e5b20a5440f8f0e1ee084e03b12Test

المؤلفون: XIAN Peng, FU Qiang, ZHENG Sen-mu, TANG Shuai, HUANG Peng-fei

المصدر: Cailiao Baohu, Vol 56, Iss 1, Pp 77-81 (2023)

مصطلحات موضوعية: 2195 al-li alloy, heat treatment state, chemical milling, surface quality, Materials of engineering and construction. Mechanics of materials, TA401-492, Technology

الوصف: For studying the effect of different heat treatment states on the chemical milling properties of 2195 Al-Li alloy, orthogonal experiments were used to research the chemical milling properties of 2195 Al-Li alloys with different heat treatment states(T8 state and O state) under different process parameters. Results showed that the chemical milling rate in T8 state was higher than that in O-state under different process parameters, and the side cutting rate in T8 state was more stable than that in O-state. Meanwhile, the surface quality of 2195 Al-Li alloy after chemical milling was related to the heat treatment state. The O-state sample had different degrees of etching grooves at the rib position after chemical milling, while the T8-state sample was smooth and flat and had better surface quality after chemical milling.

وصف الملف: electronic resource

العلاقة: http://www.mat-pro.com/fileup/1001-1560/PDF/230112.pdfTest; https://doaj.org/toc/1001-1560Test

الوصول الحر: https://doaj.org/article/61e321cc31f146ce9feca1e3d70da25bTest

المؤلفون: Zhi Liu, Ning Zhang, Xian Peng, Sannyuya Liu, Zongkai Yang

المصدر: Educational Technology & Society, Vol 26, Iss 1, Pp 1-15 (2023)

مصطلحات موضوعية: social-cognitive engagement, integrated analysis, social network analysis (sna), epistemic network analysis (ena), knowledge building, Education (General), L7-991

الوصف: Grounded on constructivism, mining a complex mix of social and cognitive interrelations is key to understanding collaborative discussion in online learning. A single examination of one of these factors tends to overlook the impact of the other factor on learning. In this paper, we innovatively constructed a social-cognitive engagement setting to jointly characterize social and cognitive aspects. In the online discussion forum, this study jointly characterized students’ social and cognitive aspects to investigate interactive patterns of different social-cognitive engagements and social-cognitive engagement evolution across four periods (i.e., creation, growth, maturity, and death). Multi-methods including social network analysis, content analysis, epistemic network analysis, and statistical analysis was applied in this study. The results showed that the interactive patterns of social-cognitive engagement were affected by both social network position and cognitive level. In particular, students’ social network position was a vital indicator for the contributions to cognitive level of students, and cognitive level affected the related interactions to some extent. In addition, this study found a nonlinear evolutionary development of students’ social-cognitive engagement. Furthermore, maturity is a critical period on which teachers should focus, as the co-occurrence of social-cognitive engagement reaches a maximum level in this period. Based on the results, this multi-perspective analysis including social and cognitive aspects can provide insightful methodological implications and practical suggestions for teachers in conducting in-depth interactive discussions.

وصف الملف: electronic resource

العلاقة: https://www.j-ets.net/collection/published-issues/26_1#h.46p3sh869dyxTest; https://doaj.org/toc/1176-3647Test; https://doaj.org/toc/1436-4522Test

الوصول الحر: https://doaj.org/article/337ff772494d4a90bb5f643da0e2c132Test

المؤلفون: Xinyu Peng, Qi Han, Xuedong Zhou, Yanyan Chen, Xiaoyu Huang, Xiao Guo, Ruiting Peng, Haohao Wang, Xian Peng, Lei Cheng

المصدر: Drug Delivery, Vol 29, Iss 1, Pp 561-573 (2022)

مصطلحات موضوعية: ph-sensitive drug delivery system, nanocarrier, chlorhexidine, dental caries, s. mutans, intelligent material, Therapeutics. Pharmacology, RM1-950

الوصف: Dental caries is a biofilm-related preventable infectious disease caused by interactions between the oral bacteria and the host’s dietary sugars. As the microenvironments in cariogenic biofilms are often acidic, pH-sensitive drug delivery systems have become innovative materials for dental caries prevention in recent years. In the present study, poly(DMAEMA-co-HEMA) was used as a pH-sensitive carrier to synthesize a chlorhexidine (CHX)-loaded nanomaterial (p(DH)@CHX). In vitro, p(DH)@CHX exhibited good pH sensitivity and a sustained and high CHX release rate in the acidic environment. It also exhibited lower cytotoxicity against human oral keratinocytes (HOKs) compared to free CHX. Besides, compared with free CHX, p(DH)@CHX showed the same antibacterial effects on S. mutans biofilms. In addition, it had no effect on eradicating healthy saliva-derived biofilm, while free CHX exhibited an inhibitory effect. Furthermore, the 16s rDNA sequencing results showed that p(DH)@CHX had the potential to alter oral microbiota composition and possibly reduce caries risk. In conclusion, the present study presents an alternative option to design an intelligent material to prevent and treat dental caries.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1071-7544Test; https://doaj.org/toc/1521-0464Test

الوصول الحر: https://doaj.org/article/c5d60a524f76469aa51c948ace0d688cTest