Characteristics of energy accumulation, evolution, and dissipation in uniaxial cyclic loading and unloading compression of 30 sandstone rock specimens under six different loading rates were explored. ...Stress–strain relations and acoustic emission characteristics of the deformation and failure of rock specimens were analyzed. The densities and rates of stored energy, elastic energy, and dissipated energy under different loading rates were confirmed, and an effective approach for the equivalent energy surface was presented. The energy evolution of rock deformation and failure were revealed. It turns out that the rock deformation behavior under uniaxial cyclic loading and unloading compression remained almost unchanged compared with that of uniaxial compression. The degree of match between reloading stress–strain curves and previous unloading curves was high, thereby demonstrating the memory function of rock masses. The intensity of acoustic emission fluctuated continually during the entire cyclic process. Emissions significantly increased as the stress exceeded the unloading level. The peak of acoustic emission increased with increasing loading stress level. Relationships between energy density and axial load indicate that the rock mass possesses a certain energy storage limitation. The energy evolution of rock masses is closely related to the axial loading stress, rather than to the axial loading rate. With increasing axial loading stress, stored energy varied most rapidly, followed by that of the elastic energy, then dissipated energy. Energy accumulation dominates prior to the axial load reaching peak strength; thereafter, energy dissipation becomes dominant. The input energy causes the irreversible initiation and extension of microcracks in the rock body. Elastic energy release leads to sudden instability of rock bodies and drives rock damage.
Despite several clinicopathological factors being integrated as prognostic biomarkers, the individual variants and risk stratification have not been fully elucidated in lower grade glioma (LGG). With ...the prevalence of gene expression profiling in LGG, and based on the critical role of the immune microenvironment, the aim of our study was to develop an immune-related signature for risk stratification and prognosis prediction in LGG.
RNA-sequencing data from The Cancer Genome Atlas (TCGA), Genome Tissue Expression (GTEx), and Chinese Glioma Genome Atlas (CGGA) were used. Immune-related genes were obtained from the Immunology Database and Analysis Portal (ImmPort). Univariate, multivariate cox regression, and Lasso regression were employed to identify differentially expressed immune-related genes (DEGs) and establish the signature. A nomogram was constructed, and its performance was evaluated by Harrell's concordance index (C-index), receiver operating characteristic (ROC), and calibration curves. Relationships between the risk score and tumor-infiltrating immune cell abundances were evaluated using CIBERSORTx and TIMER.
Noted, 277 immune-related DEGs were identified. Consecutively, 6 immune genes (
,
,
,
,
, and
) were identified as risk signature and Kaplan-Meier curve, ROC curve, and risk plot verified its performance in TCGA and CGGA datasets. Univariate and multivariate Cox regression indicated that the risk group was an independent predictor in primary LGG. The prognostic signature showed fair accuracy for 3- and 5-year overall survival in both internal (TCGA) and external (CGGA) validation cohorts. However, predictive performance was poor in the recurrent LGG cohort. The CIBERSORTx algorithm revealed that naïve CD4
T cells were significant higher in low-risk group. Conversely, the infiltration levels of M1-type macrophages, M2-type macrophages, and CD8
T cells were significant higher in high-risk group in both TCGA and CGGA cohorts.
The present study constructed a robust six immune-related gene signature and established a prognostic nomogram effective in risk stratification and prediction of overall survival in primary LGG.
To explore the acoustic emission (AE) characteristics of rock materials during the deformation and failure process under periodic loads, a uniaxial cyclic loading and unloading compression experiment ...was conducted based on an MTS 815 rock mechanics test system and an AE21C acoustic emissions test system. The relationships among stress, strain, AE activity, accumulated AE activity and duration for 180 rock specimens under 36 loading and unloading rates were established. The cyclic AE evolutionary laws with rock stress–strain variation at loading and unloading stages were analyzed. The Kaiser and Felicity effects of rock AE activity were disclosed, and the impact of the significant increase in the scale of AE events on the Felicity effect was discussed. It was observed that the AE characteristics are closely related to the stress–strain properties of rock materials and that they are affected by the developmental state and degree of internal microcracks. AE events occur in either the loading or unloading stages if the strain is greater than zero. Evolutionary laws of AE activity agree with changes in rock strain. Strain deformation is accompanied by AE activity, and the density and intensity of AE events directly reflect the damage degree of the rock mass. The Kaiser effect exists in the linear elastic stage of rock material, and the Felicity effect is effective in the plastic yield and post-peak failure stages, which are divided by the elastic yield strength. This study suggests that the stress level needed to determine a significant increase in AE activity was 70% of the
i
+ 1 peak stress. The Felicity ratio of rock specimens decreases with the growth of loading–unloading cycles. The cycle magnitude and variation of the Felicity effect, in which loading and unloading rates play a weak role, are almost consistent.
•Three different methods were used to extract longan polysaccharide.•Compared with LP-H and LP-S, LP-SE had a unique structure11LP-H, LP-S, LP-SE: longan pulp polysaccharides extracted with hot ...water, superfine grinding, superfine grinding-assisted enzymatic treatments, respectively..•LP-SE exhibited the strongest stimulation on proliferation of probssiotic.
Longan pulp polysaccharides were extracted with hot water (LP-H), superfine grinding (LP-S) and superfine grinding-assisted enzymatic treatments (LP-SE). The yields, physicochemical properties and prebiotic activities of polysaccharides were investigated. Compared with LP-H and LP-S, the yield, sugar content, solubility, arabinose and mannose percentage of LP-SE increased while its apparent viscosity, particle size, Mw and glucose percentage declined. Three LPs contained similar glycosidic linkage of →3)-α-l-Araf-(1→, →3,6)-β-d-Galp-(1→ and α-l-Rhap(l→, while they each contained specific glycosidic linkage of →4)-β-d-Glcp(l→, →4)-β-d-Galp-(1→ and →5)-α-l-Araf-(1→ in LP-H, LP-S and LP-SE, respectively. Moreover, LP-SE exhibited stronger stimulation than LP-H and LP-S on the proliferation of Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus fermentum and Leuconostoc mesenteroides. The results indicated three extraction methods had some effect on chemical composition and structure of polysaccharide. LP-SE extracted by superfine grinding-assisted enzymatic treatment exhibited the highest prebiotic activities, which have a great potential in applying in functional food and medical industry.
Photocatalytic hydrogenation provides an effective alternative way for the synthesis of industrial chemicals to meet the economic and environment expectations. Especially, over the past few years, ...metal‐organic frameworks (MOFs), featured with tunable structure, porosity, and crystallinity, have been significantly developed as many high‐performance catalysts in the field of photocatalysis. In this review, the background and development of photocatalytic hydrogenation are systemically summarized. In particular, the comparison between photocatalysis and thermal catalysis, and the fundamental understanding of photohydrogenation, including reaction pathways, reducing species, regulation of selectivity, and critical parameters of light, are proposed. Moreover, this review highlights the advantages of MOFs‐based photocatalysts in the area of photohydrogenation. Typical effective strategies for modifying MOFs‐based composites to produce their advantages are concluded. The recent progress in the application of various types of MOFs‐based photocatalysts for photohydrogenation of unsaturated organic chemicals and carbon dioxide (CO2 ) is summarized and discussed in detail. Finally, a brief conclusion and personal perspective on current challenges and future developments of photocatalytic hydrogenation processes and MOFs‐based photocatalysts are also highlighted.
In this review, the background and development of photohydrogenation are summarized. Photocatalysis is compared with thermal catalysis, and the fundamental understanding of photohydrogenation is concluded. Moreover, MOFs‐based photocatalysts, their typical modification strategies, and applications in photohydrogenation are discussed. Finally, the conclusion and perspective on challenges and developments of photohydrogenation and MOFs‐based photocatalysts are highlighted.
•The rising ranges of phenolics and antioxidant activity varied during germination.•The ratios of free and bound phenolics to total were various during germination.•Bound ferulic and coumaric acid ...contents substantially increased during germination.
Germinated brown rice is a good source of the phenolics associated with antioxidant effects. Germination significantly increased by 63.2% and 23.6% the total phenolic and flavonoid contents, respectively. The percentage contribution of bound phenolics to total was 42.3% before and decreased slightly to 37.6% after germination. The percentage contribution of bound flavonoids to total, 51.1%, was the same before and after germination. The change in the amounts of free and bound forms indicated that transformations could occur during the germination process. Six individual phenolics were detected by HPLC. The levels of ferulic, coumaric, syringic, and caffeic acid significantly increased. The ratio of bound ferric reducing antioxidant power to total was basically constant, while germination increased the ratio of bound oxygen radical absorbance capacity to total. This indicated that the increase of bound phenolics exerts beneficial health effects throughout the digestive tract after absorption and may reduce mutations.
Most of the existing researches on energy evolution in the process of rock deformation and failure mainly revolve around a specific stage (before or after the peak). However, there are few studies ...involving the impacts of lithology and loading rate on the energy evolution in the whole process from deformation to failure, especially the studies on non-linear characteristics of rock energy, which is the frontier of study on the mechanism of rock failure. In this context, this study further explores the influencing rule of lithology and loading rate on the energy evolution process of loaded rock. By employing the MTS 815 rock mechanics test system and conducting 18 groups of tests on yellow sandstone, limestone and marble, the research reveals the evolution process and distribution law of elastic energy resilience density along with the stress. Then the micro-mechanism of accumulation and dissipation of rock energy are analyzed. A non-linear evolution model (Logistic equation) is proposed that demonstrates how the energy density of loaded rock changes with axial stress. This model can also explore the bifurcation and chaos characteristics of rock energy evolution, and further reveals the rule that the iterative growth factor of energy density changes with lithology, stress level and loading rate. The results are conducive to deepening the understanding on the differences in engineering characteristics of rocks with different lithologies, and play a guiding role in the prevention and control against dynamic disasters of rocks in the engineering field.
Highlights
Evolution rules of rock elastic and dissipated energy densities were revealed.
Microscopic mechanism of rock energy accumulation and dissipation was analyzed.
Nonlinear evolution model of rock energy density vs. axial stress was established.
Bifurcation and chaos characteristics of the rock energy evolution were analyzed.
•Free & bound phytochemicals in milled fractions of black rice exist differences.•The changing ranges of free & bound phytochemicals varied after extrusion.•Extrusion slightly increases the release ...of phytochemicals in black rice bran fraction.•Extrusion causes significant phytochemical loss in polished/brown rice fractions.•Free fractions contributes most to total phytochemicals before and after extrusion.
The phytochemical profile and antioxidant activities of unprocessed and extruded milled fractions of black rice were investigated. Extrusion increased the free phenolics, anthocyanins and oxygen radical absorbance capacity (ORAC) and decreased the bound forms. The total phenolics, anthocyanins and ORAC increased by 12.6%, 5.4% and 19.7%, respectively, in bran. Extrusion decreased both free and bound phenolics and anthocyanins while ORAC values decreased by 46.5%, 88.4% and 33.1%, respectively, in polished rice and by 71.2%, 87.9% and 14.7%, respectively, in brown rice. A total of seven phenolics, gallic, chlorogenic, vanillic, caffeic, syringic, p-coumaric and ferulic acids, were detected in both forms. Cyanidin 3-glucoside (Cy-3-G), cyanidin 3-rutinoside and peonidin 3-glucoside were also detected with Cy-3-G found in the highest amounts in unprocessed and extruded rice bran. These results provide the basis for the development of different milled fractions of extruded black rice with balanced nutritional characteristics for today’s functional food markets.
China's Chang'E-5 (CE-5) mission has collected 1.731 kg samples from a young mare basalt unit (named P58/EM4) in the northeastern Oceanus Procellarum region of the Moon. Accurate tracing of the ...provenance of returned samples is essential for understanding their laboratory measurements, which can provide critical information about the Moon and the inner Solar System. In this article, the provenance, chemical composition, formation, and evolution processes of the regolith at the CE-5 landing site are analyzed by using remote sensing observations and crater ejecta deposition models. A comprehensive search based on crater ejecta thickness model shows that 1892 impact craters in P58 likely deposited ∼0.56 m of primary ejecta at the landing site, whereas 4 impact craters outside P58 deposited 0.05 m of distal ejecta that further excavated and reworked ∼0.5 m thick local mare basalt. Twelve craters within 1 km from the CE-5 landing site are estimated to contribute ∼0.49 m (~88%) of the ejecta materials, and their ejecta source regions are investigated using the Maxwell Z model. Among these 12 craters, Xu Guangqi and a smaller crater near the landing site are the two most volumetrically significant contributors (~0.3 m and ∼0.12 m). Craters more than 1 km distant from the landing site deposited fewer exotic materials, but some of them could have delivered low-Ti materials to the sampling site. Finally, the regolith stratigraphy at the landing site is investigated based on the identified and assumed impact sequence by using a Monte Carlo-based ejecta ballistic sedimentation model. The results reveal a depth-varying FeO/TiO2 abundance profile at the landing site, suggesting that the sedimentation of distant ejecta can reduce FeO/TiO2 abundance of the underlying layer by ∼1 wt.% at ∼0.5 m depth. Our results provide key information on sample provenance and regolith stratigraphy of the landing site, which is crucial to deciphering the returned CE-5 samples.
•The provenance of the Chang'E-5 samples is investigated using crater ejecta deposition models.•In total 1896 craters likely deposited about 1.1 m thick ejecta at the CE-5 landing site.•The young crater, Xu Guangqi, is the most volumetrically significant contributor.•Distant craters may have delivered low-Ti materials to the CE-5 landing site.•A depth-varying composition profile at CE-5 the landing site is predicted.
•Free & bound antioxidant phenolics in endosperm and bran of indica rice investigated.•Phenolic content and antioxidant activity of bran/embryo mainly exist in free form.•The endosperm fraction ...contains both free and bound forms of phenolics.•Bran/embryo fraction contributes most to phenolics content and total antioxidant activity.•Ferulic and coumaric acid in bound forms were distributed mainly in bran/embryo.
This study quantified free and bound phytochemicals and their antioxidant activity in the endosperm and bran/embryo of different indica rice varieties. Phytochemicals mainly existed as free form in the bran/embryo and as both free and bound forms in the endosperm. The average values of total phenolic content, flavonoid content, FRAP, ABTS and ORAC values in the bran/embryo were 3.1, 10.4, 8.2, 11.2 and 11.4 times higher than those in the endosperm, respectively. In whole brown rice, the bran contributed 59.2%, 53.7%, 47.7%, 55.5% and 56.9% of total phenolics, flavonoids, FRAP, ABTS and ORAC values, respectively. Seven individual phenolics (gallic, protocatechuic, chlorogenic, caffeic, syringic, coumaric and ferulic acids) were detected with most coumaric and ferulic acids in the bran. All measurements exhibited varietal differences. These findings provide important information for improving human health by encouraging the consumption of whole brown rice and its use in food product development.
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