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The Sinian Doushantuo and the Cambrian Niutitang formations in southern China have a good shale gas resource potential. Although >20 wells have already been drilled in these formations, the shale gas production has been much lower than expected, due to the high thermal maturity of the rocks and the severely disturbed geological structure of the corresponding area. An industrial gas flow was discovered only in the Weiyuan region. To achieve the shale gas breakthrough of paleo-shale strata, it is necessary to find a shale reservoir with low thermal maturity and weak geological deformation. On the basis of the study on the Weiyuan, Huangling and other paleo-uplifts, a shale gas accumulation mechanism named "shale gas accumulating around the edges of paleo-uplifts" was proposed. It has been suggested that the shale gas is usually contained within the slope belt of a paleo-uplift margin characterized by a shallow burial depth, stable structure activity, and a low level of thermal maturity. Taking into account this accumulation mechanism, a large number of wells have been drilled on the southern edge of the Huangling paleo-uplift (western Hubei province). Organic-enriched shales with high shale gas content and low thermal maturity, have been found within the Sinian Doushantuo and the Cambrian Niutitang formations. To tackle the problems deriving from the low exploration level, complex geological structure, low temperature, and low pressure in the region, we proposed and applied innovative fracturing process, new complex fracturing techniques and new recovering technology systems. High and stable shale outputs were obtained from the Niutitang Formation (well Yangye-1HF, HF: Horizontal Well Fracturing) and from the Doushantuo Formation (well Yangye-2HF): 7.83 × 104 and 5.53 × 104 m3/day, respectively. These outputs were achieved following horizontal well section fracturing, which resulted in a significant breakthrough for the production capacity of the low-pressure shale gas reservoir in the complex tectonic region outside of the Sichuan Basin. • The shale gas accumulated around the edges of the paleo-uplifts. • The reservoir with complex fractures and low pressure can be reconstructed by new technology. • The Cambrian and Sinian organic-enriched shale has a good shale gas potential. [ABSTRACT FROM AUTHOR]

Isoalantolactone (IAL) is an active sesquiterpene naturally present in many vegetables, condiments and medicinal plants. In this study, an efficient strategy was developed for the identification of metabolites following the in vivo metabolism and in vitro biotransformation of IAL with rat intestinal bacteria utilizing ultra performance liquid chromatography combined with Triple TOF mass spectrometry (UPLC - Triple TOF-MS/MS). As a result, 46 metabolites including 34 novel sulfur-containing products were identified. The results demonstrated that IAL could undergo general metabolic reactions, including oxidation, hydration, hydrogenation, demethylation, cysteine conjugation and N-acetylcysteine conjugation, but the most noticeable characteristic of IAL metabolism was the H 2 S addition to the double bond between C-11 and C-13 and subsequent reactions to produce a series of novel sulfur-containing dimers. This is the first study of IAL metabolism in vivo , whose results provide novel and useful data for a better understanding of the safety and efficacy of IAL. [ABSTRACT FROM AUTHOR]

• A HMABC algorithm based on load balance was proposed. • The scouter bee mechanism solves the problem of falling into local optimum. • The THR based on machine load balance improves local search ability. • The HMABC is applied successfully into aviation composite materials manufacturing. The manufacturing of composite materials for the aerospace industry represents a cornerstone of future development in this advanced field. In this study, a mathematical model of flexible job-shop scheduling problem (FJSP) was established by extracting the key manufacturing information from an aerospace composite manufacturing workshop. Intelligent algorithms can effectively solve FJSP. However, when applied to a multi-objective FJSP (MOFJSP), they suffer from drawbacks such as blind search and low efficiency. Therefore, this study proposes a new artificial bee colony algorithm and implements it as part of a hybrid method (referred to as the HMABC) to solve MOFJSP. The method involves three steps: (1) A multiple-rule initial population is constructed to minimize randomness and improve quality. (2) A greedy decoding method is used to decode each individual to further narrow the search range to replace the conventional decoding method. (3) By considering the machine load index (which has often been neglected), the concept of machine load rate is proposed, and three heuristic strategies are designed (with the influences ranging from small to high) to diverge the solution in all directions instead of just a direction. The performance of the proposed method is compared with those of existing algorithms using a classical FJSP test example, and the effectiveness and efficiency of HMABC is verified. Finally, the method is applied to an actual aerospace composite manufacturing system to realize the scheduling of actual production activities. [ABSTRACT FROM AUTHOR]

Introduction: Inflammatory responses play an important role in the pathogenesis of preeclampsia. Recently, the anti-inflammatory role played by autophagy has drawn increasing attention. Our aim was to investigate variations in autophagy in preeclampsia and protection against oxidized low-density lipoprotein (oxLDL)-mediated inflammation by autophagy.Methods: We used immunohistochemistry, immunofluorescence, quantitative real-time PCR, and western blotting to analyze the expression of autophagy proteins (beclin-1 and LC3II/LC3I) in preeclampsia placentas and in JEG-3 cells treated with oxLDL and rapamycin.Results: We found a decreased level of autophagy proteins in preeclampsia placentas, and oxLDL did not induce autophagy in JEG-3 cells. Furthermore, when cells were pretreated with rapamycin, autophagy was activated and expression of inflammatory factors (tumor necrosis factor-α and interleukin-6) induced by oxLDL was downregulated.Conclusion: We conclude that impaired autophagy in preeclampsia has potential to decrease trophoblast protection from oxidative and inflammatory stress, thereby contributing to the pathogenesis of preeclampsia. [ABSTRACT FROM AUTHOR]

Popular courses are representative of high-quality courses on MOOC (Massive Open Online Course) platforms. However, current research on the formation mechanism of popular courses is rare. Thus, a fuzzy-set qualitative comparative analysis (fsQCA) is adopted to explore configurations of MOOC quality elements for popular courses on MOOC platforms. This study selects courses on the Coursera platform as the research object. Unique datasets of 272 observations and 261 observations before and after the outbreak of pandemic, respectively, are used to investigate for a better understanding of the role of quality elements in forming popular courses. Three key findings are revealed. First, the configurations for MOOC popular courses differ from those of nonpopular courses, suggesting an asymmetric view of causality that underpins MOOC quality. Second, parsimonious configurations emergent from complex interactions among eight MOOC quality elements which are selected from three aspects of MOOC course arrangement, MOOC teaching faculty arrangement, and MOOC learner reviews, suggesting causality of equifinality that produces a popular course both before and after the outbreak of pandemic. Notably, the role of the professional title of MOOCs teachers becomes more important for forming popular courses after COVID-19. Third, although the number of MOOC teachers appears as a peripheral element along with the number of long reviews as a core element in all configurations for popular courses, they need the presence of other quality elements to form popular courses, suggesting a conjunction between quality elements. All findings provide implications not only for MOOC providers to regard popular courses as a result of configurations of MOOCs quality elements, but also for further research on fsQCA in course quality on MOOC platforms. • A fuzzy-set qualitative comparative analysis (fsQCA) is adopted. • Configurations of MOOC quality elements for popular courses is explored. • The configurations for MOOC popular courses differ from those of nonpopular courses. • The role of the professional title of MOOCs teachers becomes more important after COVID-19. • There exists a conjunction between quality elements. [ABSTRACT FROM AUTHOR]

To enhance prediction reliability and accuracy, a hybrid model based on the promising principle of “decomposition and ensemble” and a recently proposed meta-heuristic called grey wolf optimizer (GWO) is introduced for daily PM 2.5 concentration forecasting. Compared with existing PM 2.5 forecasting methods, this proposed model has improved the prediction accuracy and hit rates of directional prediction. The proposed model involves three main steps, i.e., decomposing the original PM 2.5 series into several intrinsic mode functions (IMFs) via complementary ensemble empirical mode decomposition (CEEMD) for simplifying the complex data; individually predicting each IMF with support vector regression (SVR) optimized by GWO; integrating all predicted IMFs for the ensemble result as the final prediction by another SVR optimized by GWO. Seven benchmark models, including single artificial intelligence (AI) models, other decomposition-ensemble models with different decomposition methods and models with the same decomposition-ensemble method but optimized by different algorithms, are considered to verify the superiority of the proposed hybrid model. The empirical study indicates that the proposed hybrid decomposition-ensemble model is remarkably superior to all considered benchmark models for its higher prediction accuracy and hit rates of directional prediction. [ABSTRACT FROM AUTHOR]

A thermoacoustic electric generator without resonator designed for aerospace application is discussed in this study, which is developed by a traveling-wave looped-tube thermoacoustic heat engine coupling with two linear alternators directly. A novel method of filling phase modulation object in the acoustic power output port is proposed to improve the performance of the thermoacoustic electric generator. The experimental results show that the ellipsoid makes the most significant influence among sphere, cylinder and ellipsoid serving as phase modulation object. Varying the major axis of the ellipsoid only, the influence of it increases first and then decreases. The ellipsoid fixed in different positions makes different effects. The maximum output electric power of 73.31 W and the maximum system efficiency of 14.12% are obtained in the upper and middle positions respectively. [ABSTRACT FROM AUTHOR]

This work is to study the potential of particles fabricated from soy protein isolate (SPI) as a protective carrier for quercetin. When the concentration of SPI particles increases from 0 to 0.35 g/L, quercetin gives a gradually increased fluorescence intensity and fluorescence anisotropy. The addition of quercetin can highly quench the intrinsic fluorescence of SPI particles. These results are explained in terms of the binding of quercetin to the hydrophobic pockets of SPI particles mainly through the hydrophobic force together with the hydrogen bonding. The small difference in the binding constants at 25 and 40 °C suggests the structural stability of SPI particles. The relative changes in values of Gibbs energy, enthalpy, and entropy indicate that the binding of quercetin with SPI particles is spontaneous and hydrophobic interaction is the major force. Furthermore, SPI particles are superior to native SPI for improving the stability and radical scavenging activity of quercetin. [ABSTRACT FROM AUTHOR]

Soil methanotrophs are the only biological sink for atmospheric methane (CH 4). The activity and the diversity of methanotrophic communities in grassland soils can be impacted by animal grazing. In this study, soils were collected from a 17-year running grazing intensity trial in a typical steppe in the Loess Plateau, China to examine the responses of CH 4 oxidation rate and active methanotroph composition and abundance to different levels of sheep grazing. Soils were collected from summer grazed pastures at no (0 sheep ha−1), low (2.67 sheep ha−1), moderate (5.33 sheep ha−1) and high (8.67 sheep ha−1) levels of grazing. We found that all soils were able to oxidize atmospheric and high concentration (10%) CH 4 through soil methanotrophs. Compared to ungrazed soils, the atmospheric CH 4 oxidation rate and methanotroph abundance were higher in low and high grazed soils but lower in moderately grazed soils. Across all soils, the in-situ methanotroph community was dominated by upland soil cluster gamma methanotrophs and potentially contributed to the atmospheric concentration CH 4 oxidation. Soil methanotroph community responses to the high 13CH 4 concentration revealed an increase in methanotroph abundance and a transition of the active methanotroph community to traditional Type I (Methylocaldum and Methylobacter) and Type II (Methylocystis) methanotrophs. Methylocaldum responses to the high CH 4 concentration were greater in highly grazed soil than in ungrazed soil. The activity of Methylobacter and Methylocystis under high CH 4 concentrations was reduced by high grazing intensity. This study provides evidence that recent intensifications of animal grazing can result in particular community assembly of microbial methane oxidizers responsible for CH 4 sink capabilities of grassland soils. • Sheep grazing modifies CH 4 uptake and methanotroph community of a typical steppe soil. • USCγ dominated the in-situ methanotroph community. • Atmospheric concentration CH 4 oxidation was driven by USCγ methanotrophs. • High concentration CH 4 oxidation was driven by traditional Type I and Type II methanotrophs. [ABSTRACT FROM AUTHOR]

Ischemic stroke (IS) is a heterogeneous multifactorial disorder caused by both genetic and environmental factors. A genome-wide association study on stroke in Caucasians identified a variant on chromosome 4q25 that is significantly associated with IS, with the strongest risk for cardioembolic stroke (CES). The current study aims to investigate the association of the rs1906591 variant on 4q25 with IS through a case-control study in a Chinese Han population. A total of 712 IS patients and 774 control subjects were involved in the current research. Stroke subtyping was performed according to the Trial of Org 10172 in Acute Stroke Treatment criteria. The genotypes were determined using the SNaPshot technique. The association of the genotypes with the risk of IS was estimated using logistic regression analysis. The rs1906591 single nucleotide polymorphism variant was associated with the CES subtype in both recessive and additive models (recessive model: odds ratio [OR] = 2.58, 95% confidence interval [CI] 1.47–4.53, p = 0.001, adjusted OR = 2.71, 95% CI 1.48–4.96, p = 0.001; additive model: OR = 2.50, 95% CI 1.19–5.25, p = 0.015, adjusted OR = 2.83, 95% CI 1.24–6.50, p = 0.013). This result indicates that patients with the AA genotype have a higher rate of CES than other genotypes. However, the rs1906591 variant was not significantly associated with the overall incidence of stroke or other stroke subtypes. The rs1906591 variant is significantly associated with CES in the Chinese Han population, but not with other stroke subtypes. [ABSTRACT FROM AUTHOR]

Abstract: 1-(Morpholin-1-yl-pyridin-2-yl-methyl)-2-naphthol as a novel efficient N–O ligand has been developed for palladium-catalyzed Mizoroki–Heck reaction in neat water without the protection of an inert atmosphere. The reactions proceed smoothly and give the desired products in moderate to excellent yields. The catalyst system is reusable. [Copyright &y& Elsevier]

Abstract: Tetraethylenepentamine and triethylenetetramine are found to be efficient organic bases for the N-arylation of pyrazole and imidazole with aryl and heteroaryl-iodides and -bromides catalyzed by CuI in water at moderate temperature. The cross-couplings proceed smoothly with good to excellent yields and a variety of functional groups are tolerated under this condition. [Copyright &y& Elsevier]

Abstract: Activated-copper powder is an efficient catalyst for the N-arylation of heterocycles with aryl halides and can be reused several times. The reactions can proceed smoothly in water by using LiOH as base and give the corresponding products in good yields. The protocol shows good tolerance toward various functional groups. [Copyright &y& Elsevier]