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Underground space creation and energy extraction, which induce unloading on rock fractures, commonly occur in various rock engineering projects, and rock engineering projects are subjected to high temperatures with increasing depth. Fluid flow behavior of rock fractures is a critical issue in many subsurface rock engineering projects. Previous studies have extensively considered permeability evolution in rock fractures under loading phase, whereas changes in fracture permeability under unloading phase have not been fully understood. To examine the unloading-induced changes in fracture permeability under different temperatures, we performed water flow-through tests on fractured rock samples subjected to decreasing confining pressures and different temperatures. The experimental results show that the permeability of fracture increases with unloading of confining pressure but decreases with loading-unloading cycles. Temperature may affect fracture permeability when it is higher than a certain threshold. An empirical model of fracture hydraulic aperture including two material parameters of initial normal stiffness and maximum normal closure can well describe the permeability changes in rough rock fracture subjected to loading-unloading cycles and heating. A coupled thermo-mechanical model considering asperity damage is finally used to understand the influences of stress paths and temperatures on fracture permeability.

Geothermal wells often suffer from production difficulties such as disappointing injectivity/productivity right from the start or declining injectivity/productivity during long-term operation, Acid fracturing, as a soft stimulation technology, is becoming the preferred technology to stimulate the carbonate geothermal reservoir of low permeability in large depth. The basic mechanism of acid fracturing is to inject acid into the carbonate geothermal reservoir through geothermal wells, and then the matrix porosity and fracture apertures can be significantly improved through acid corrosion. Since the acid fracturing technology in geothermal reservoirs is mainly based on the experiences obtained from oil and gas fields, a complete technical system has not yet been established. To be specific, its design method and field implementation process lack theoretical guidance. In this paper, two correction coefficients are proposed to describe the acid etching induced changes in fracture normal stiffness and the maximum closure, based on which a nonlinear fracture constitutive model considering the coupled mechanical-chemical mediations on fracture apertures is developed. The developed nonlinear fracture constitutive model is incorporated into the theoretical framework of coupled thermal-hydraulic-mechanical-chemical processes in fractured rock mass, and a numerical modeling method suitable for acid fracturing in deep carbonate geothermal reservoir is developed. Based on the field test of acid fracturing in the geothermal well D22 in Xiong’an New Area, Hebei, China, the accuracy of the developed modeling method is verified, and the influences of human-controlled parameters including perforation position, acid concentration (mass fraction) and injection rate on the stimulation efficiency of acid fracturing is investigated though sensitivity analysis. The results show that acid fracturing mainly occurs within the fractures with high initial apertures in the carbonate geothermal reservoir of low permeability in large depth. The acid-etched fractures gradually propagated into the surrounding reservoir rocks with high permeability, and a stimulated network is formed after acid fracturing. Stimulation efficiency of acid fracturing is dependent on not only the increase in fracture apertures induced by acid etching and hydraulic pressure, but also the closure path of fractures after stimulation. The closer the perforation position is to the reservoir rocks with high permeability, the better stimulation efficiency of acid fracturing. The high acid concentration and injection rate are helpful to stimulate long fractures, by which the reservoir rocks with high permeability may be connected, and thus the better stimulation efficiency of acid fracturing is obtained.

BackgroundNumerous investigations have demonstrated a strong association between the TyG (triglyceride-glucose) index, which is derived from lipid and glucose levels in the bloodstream, and the onset and progression of cardiovascular diseases (CVD). Blood glucose and blood lipids are affected by nutritional status, and few studies have explored whether the correlation between TyG index and the risk of CVD is affected by nutritional status.AimsTo investigate the connection between TyG index and the risk of CVD among individuals with varying nutritional statuses.MethodA total of 19,847 were included in the analysis, of which 15,955 participants were non-malnourished and 3,892 patients were malnourished. According to the TyG index quartile, the patients were categorized into four groups. Logistic regression analysis and restricted cubic spline was used to study the relationship between TyG index and the risk of CVD in normal and malnourished populations.ResultsThe results of the restricted cubic spline showed that the TyG index was positively associated with the risk of CVD in the non-malnourished population. The TyG index showed a U-shaped association with the risk of CVD in malnourished people. The result is consistent with that of logistic regression (Malnutrition: Group 2: OR: 1.14; 95% CI: 0.85–1.53; Group 3: OR: 1.36; 95% CI: 1.03–1.79; Group 4: OR: 1.72; 95% CI:1.31–2.25, P for trend

Insects have a long history of being used in medicine, with clear primary and secondary functions and less side effects, and the study and exploitation of medicinal insects have received increasing attention. Insects gut microbiota and their metabolites play an important role in protecting the hosts from other potentially harmful microbes, providing nutrients, promoting digestion and degradation, and regulating growth and metabolism of the hosts. However, there are still few studies linking the medicinal values of insects with their gut microbes. In this study, we focused on the specific gut microbiota common to medicinal insects, hoping to trace the potential connection between medicinal values and gut microbes of medicinal insects. Based on 16S rRNA gene sequencing data, we compared the gut microbiota of medicinal insects [Periplaneta americana, Protaetia (Liocola) brevitarsis (Lewis) and Musca domestica], in their medicinal stages, and non-medicinal insects (Hermetia illucens L., Tenebrio molitor, and Drosophila melanogaster), and found that the intestinal microbial richness of medicinal insects was higher, and there were significant differences in the microbial community structure between the two groups. We established a model using a random-forest method to preliminarily screen out several types of gut microbiota common to medicinal insects that may play medicinal values: Parabacteroides goldsteinii, Lactobacillus dextrinicus, Bifidobacterium longum subsp. infantis (B. infantis), and Vagococcus carniphilus. In particular, P. goldsteinii and B. infantis were most probably involved in the anti-inflammatory effects of medicinal insects. Our results revealed an association between medicinal insects and their gut microbes, providing new development directions and possibly potential tools for utilizing microbes to enhance the medicinal efficacy of medicinal insects.

Oxidative stress and obesity are critical risk factors for metabolic syndrome. The consumption of functional food ingredients can a viable strategy to alleviate oxidative stress and obesity. In this study, the hydro-ethanolic extract of the edible insect Polyrhachis vicina was prepared and its bioactive components were characterized. The total polyphenol contents, total flavonoid contents, antioxidant and pancreatic lipase (PL) inhibitory activities of the extract were determined in vitro. In total, 60 bioactive components were tentatively identified in the P. vicina extract. Polyphenols and fatty acids were further quantified using LC-MS and GC-MS, respectively. P. vicina extract possessed excellent antioxidant and PL inhibition activities. Salicylic acid, gallic acid, liquiritigenin, and naringenin, which were the major polyphenols in the P. vicina extract, interacted with PL through hydrogen bonding, hydrophilic or hydrophobic and pi-cation interactions. Thus, P. vicina extract can be used as a nutraceutical to alleviate oxidative stress-induced disease and manage obesity.

Weak scattering in a random disordered medium and the associated extreme-event statistics are of great interest in various physical contexts. Here, in the context of non-relativistic particle motion through a weakly correlated random potential, we show how extreme events in particle densities are strongly related to the stretching exponents, where the ’hot spots’ in the intensity profile correspond to minima in the stretching exponents. This strong connection is expected to be valid for different random potential distributions, as long as the disorder is correlated and weak, and is also expected to apply to other physical contexts, such as deep ocean waves.

Chitosan (CS) has limited capacity for Ca(II)-adsorption abilities. Here, glutaraldehyde cross-linked chitosan (GLA-CTS) and maltose chitosan (MAL-CTS) were obtained by physical and chemical modifications to improve the adsorption of Ca2+. By comparing the adsorption kinetics and isotherm, the adsorption capabilities of GLA-CTS and MAL-CTS reached 112.27 ± 2.63 and 240.38 ± 31.88 mg/g in the presence of concentrations of 3000 mg/L Ca2+, which were about 2.1 and 4.6 times than CS. The structures of the resulting calcified complexes were profiled by SEM, XPS, FT-IR, and 13C NMR. Unlike the folds and spherical particles observed in CS-Ca(II) and GLA-CTS-Ca(II), the surface morphology of MAL-CTS-Ca(II) presented as flat-membrane-structures. In XPS assays, the peaks of Ca in GLA-CTS-Ca(II) and MAL-CTS-Ca(II) were significantly higher than that of CS-Ca(II), and the percentages of Ca atoms on the surfaces were 1.67 and 1.95 times higher respectively. Structural analyses were indicated from the FT-IR and 13C NMR results, the –NH2, –NHCOCH3 and –OH groups were all involved in the adsorption to Ca2+, and the worked groups were changed when calcium contents increased. Accordingly, possible structures of Ca(II)-complexes and the adsorption mechanisms were initially proposed. These two chitosan derivatives with evidently improved Ca(II)-adsorption are favorable for developing applications based chitosan.

Abstract Emerging trends in the use of smartphones, online mapping applications, and social media, in addition to the geo-located data they generate, provide opportunities to trace users’ socio-economic activities in an unprecedentedly granular and direct fashion and have triggered a revolution in empirical research. These vast mobile data offer new perspectives and approaches to measure economic dynamics, and they are broadening the social science and economics fields. In this paper, we explore the potential for using mobile data to measure economic activity in China from a bottom-up view. First, we build indices for gauging employment and consumer trends based on billions of geo-positioning data. Second, we advance the estimation of offline store foot traffic via location search data derived from Baidu Maps, which is then applied to predict Apple’s revenues in China and to accurately detect box-office fraud. Third, we construct consumption indicators to track trends in various service sector industries and verify them with several existing indicators. To the best of our knowledge, this is the first study to measure the world’s second-largest economy by mining such unprecedentedly large-scale and fine-granular spatial-temporal data. In this way, our research provides new approaches and insights into measuring economic activity.

Among different insects, the American cockroach (Periplaneta americana) has been bred in industrial scale successfully as a potential resource of protein, lipid, and antibacterial peptide. However, the application of its chitosan has not been studied widely, which has hindered the sufficient utilization of P. americana. In this paper, the chitosan from P. americana was separated, characterized, and processed into film (PaCSF) to examine its potential of being applied in food packaging. As the results of different characterizations showed, PaCSF was similar to shrimp chitosan film (SCSF). However, concerning the performances relating to food packaging, the two chitosan films were different. PaCSF contained more water (42.82%) than SCSF did, resulting in its larger thickness (0.08 mm). PaCSF could resist UV light more effectively than SCSF did. Concerning antioxidant activity, the DPPH radical scavenging ability of PaCSF increased linearly with time passing, reaching 72.46% after 8 h, which was better than that of SCSF. The antibacterial activity assay exhibited that PaCSF resisted the growth of Serratia marcescens and Escherichia coli more effectively than SCSF did. The results implied that P. americana chitosan could be a potential raw material for food packaging, providing a new way to develop P. americana.

Projecting itself as the inheritor of China's past greatness, the CCP regime increasingly seeks to boost politico-cultural confidence in education and society and turn students and ordinary people into self-confident Chinese. This article identifies the oscillation of focus from victimhood to confidence in state nationalism and patriotic education and interrogates the politics behind the official push for self-confidence. Through the lens of Foucauldian governmentality and subjectivation, it argues that self-confidence serves as a governing technique for the party-state to subjugate people by individuating and subjectivising a verifiable feeling of certainty about the future, which depends on the CCP, pathologises political grievances, and precludes alternative political imaginaries. To be constructive as well as critical, this article draws upon contemporary political theory to suggest that education for humble citizenship, which centres on contingency, interdependence, and critique of the past and present, is key to citizenship education that strives for desubjugation and autonomy.

This article provides an overview of the politics of education as they affect regions and communities on the periphery of the People's Republic of China. Drawing on the articles in this special issue of Comparative Education, it analyses tensions related to the attempted imposition of Bejing's homogenising and totalising vision of Chineseness across Tibet, Xinjiang, Inner Mongolia, Hong Kong, Taiwan and amongst the mainland's migrant underclass. Also considered here are the politics of comparative educational scholarship, as they relate to a widespread failure to engage critically with the diversity and complexity of Chinese societies. Attributable largely to the West's own 'culture wars', this failure betrays much-touted ethical commitments to social justice and anti-'hegemonic' resistance. It is thus a central purpose of this essay - and special issue - to urge educational scholars to interrogate the politics of oppression and injustice in China and elsewhere 'beyond the Western horizon'.

While historically and ideologically peripheralised in modern Chinese politics, traditional culture has been discursively rehabilitated by the Chinese communist regime in recent years. Existing literature on this phenomenon tends to focus on the politicisation of culture, that is, how Chinese culture, particularly the Confucian tradition, is appropriated by the regime to legitimatise and stabilise its ideopolitical control in schools and society. This article draws attention to the interweaving but distinct and underexplored tendency of the culturalisation of politics, that is, the party-state's discursive construction of politics in culturalist terms. It examines how politics is culturally constructed, or culturalised, in the official textbooks for the guiding political doctrine Xi Jinping Thought, the teaching of which has been mandatory in schools and universities since 2021. Situating the Chinese case in the broader context of the 'cultural turn' in postmodern politics, this article discusses the implications for citizenship education under China's authoritarian regime.