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A comparative experimental and numerical study of the impact behaviour of carbon-fiber-reinforced thermoplastic (TP) and thermoset (TS) composites has been carried out. On the one hand, low velocity impact (LVI) tests were performed on TP and TS composites with different lay-up sequences at different energy levels, and the damage modes and microscopic damage mechanisms after impact were investigated using macroscale inspection, C-scan inspection, and X-ray-computed tomography. The comparative results show that the initial damage valve force under LVI depends not only on the material, but also on the layup sequence. The initial valve force of the P2 soft layer with lower stiffness is about 11% lower than that of the P1 quasi-isotropic layer under the same material, while the initial valve force of thermoplastic composites is about 28% lower than that of thermoset composites under the same stacking order. Under the same stacking order and impact energy level, the damage area and depth of TP composites are smaller than those of TS composites; while under the same material and impact energy level, the indentation depth of P2 plies is greater than that of P1 plies, and the damage area of P2 plies is smaller than that of P1 plies, but the change of thermoplastic composites is not as obvious as that of thermoset composites. This indicates that TP composites have a higher initial damage threshold energy and impact resistance at the same lay-up order, while increasing the lay-up ratio of the same material by 45° improves the impact resistance of the structure. In addition, a damage model based on continuum damage mechanics (CDM) was developed to predict different damage modes of thermoplastic composites during low velocity impact, and the analytical results were compared with the experimental results. At an impact energy of 4.45 J/mm, the error of the initial damage valve force is 5.26% and the error of the maximum impact force is 4.36%. The simulated impact energy and impact velocity curves agree with the experimental results, indicating that the finite element model has good reliability. [ABSTRACT FROM AUTHOR]

Microalgae are the largest CO 2 fixer and O 2 producer on the earth and occupy an increasingly important position in human life and production. Various environmental factors have a significant impact on the growth and metabolism of microalgae. As global warming intensifies, heat stress has become a crucial factor affecting the microalgae industry. However, till now, it has not been clear how microalgae sensed the temperature stress, transmitted stress signals and adjusted in intracellular metabolic pathways. In this study, the growth of microalgae Auxenochlorella protothecoides UTEX2341 was inhibited at 32 °C, but the single cell dry weight increased. The cell component analyses showed that both the carbohydrate and total protein content decreased significantly, while the lipid content increased by 158%. Meanwhile, the intracellular Ca2+ concentration increased continuously, with a maximum increase of 1.65 times. According to the transcriptome analyses, the up-regulation of Ca2+ influx channel protein mid1-complementing activity 1 (MCA1) gene and the down-regulation of efflux channel protein cation exchanger 1(CAX) and autoinhibited Ca2+-ATPase 1 (ACA1) genes in cytoplasmic membrane jointly facilitated the increase of Ca2+ in the cytoplasm. Coexpression network analysis indicated that the fluctuation of Ca2+ in the cytoplasm could activate the expression of transcription factors MYB3 and AP2-4 through calmodulin (CAM) and calcium-dependent protein kinase (CDPK), and then regulate glycerol-3-phosphate acyltransferases (GPAT) at the beginning of TAG synthesis and diacylglycerol acyltransferase (DGAT)/phospholipid: diacylglycerol acyltransferase (PDAT) in the last step of TAG synthesis. Furthermore, the addition of Ca2+ specific chelator BAPTA-AM inhibited the expression of GPAT , which was consistent with the decrease in microalgae lipid content. The results proved that Ca2+ participated in the regulation of microalgae TAG synthesis under heat stress, which provided a new view for the understanding of the microalgae lipid accumulation mechanism. [Display omitted] • Heat stress was transmitted to microalgae through Ca2+. • MCA1 channel protein was the valve of Ca2+ influx under heat stress. • Ca2+ influx was the internal cause of the TAG accumulation increase. [ABSTRACT FROM AUTHOR]

The vibration and damping characteristics of free-free composite sandwich cylindrical shell with pyramidal truss-like cores have been conducted using the Rayleigh-Ritz model and finite element method. The predictions for the modal properties of composite sandwich cylindrical shell with pyramidal truss-like cores showed good agreement with the experimental tests. The influences of fiber ply angles on the natural frequency and damping loss factor were investigated. Three types of such composite sandwich cylindrical shells were manufactured using a hot press molding method and the relevant modal characteristics of various sandwich cylindrical shells could be obtained by modal tests. It can be found that modal strain energy approach was effective to estimate the structural damping loss factors and the variation of damping for each vibration modes could be explained suitably through the contributions of each strain energy components. Results showed that the structural damping loss factors not only depended on inherent material damping, but also relied on the vibration modes. The natural frequencies of composite sandwich cylindrical shell increased with the increasing of the ply angle of the inner and outer curve face sheets, whereas the damping loss factors of present shells did not increase monotonically. [ABSTRACT FROM AUTHOR]

Abstract: The vibration and damping performances of hybrid carbon fiber composite pyramidal truss sandwich panels with viscoelastic layers embedded in the face sheets were investigated in this paper. Hybrid carbon fiber composite pyramidal truss sandwich panels containing different thickness of viscoelastic layers were manufactured using a hot press molding method. Analytical models based on modal strain energy approach were developed using ABAQUS software to estimate the damping property of the hybrid sandwich structures. A set of modal tests were carried out to investigate the vibration and damping characteristics of such hybrid sandwich panels with or without viscoelastic layers. The damping loss factors of composite slender beams with different fiber orientations were tested to determine the constitutive damping properties of parent materials for such hybrid sandwich panels. The numerical simulation results showed good agreement with the experimental tests. The damping loss factors of hybrid sandwich panels increased distinctly compared with previous sandwich panels due to the viscoelastic layer embedded in the face sheets. [Copyright &y& Elsevier]

Abstract: This study is concerned with an actual collapse testing under the flap-wise loading for a large full-scale composite wind turbine blade, and a discussion is conducted to assess and evaluate the structural response of the blade during loading and after collapse by correlating experimental findings with numerical model predictions. A videometrics technique is adopted to measure the integral deformation and the local deformation of the wind turbine blade under the flap-wise loading. The measured results show that the displacement of the blade tip is up to 11m at the ultimate load which is 160% of the extreme design load for the tested blade. A simple method is proposed to identify the exact failure location of the blade based on the deformation data. The thorough analysis results indicate that the aerodynamic shells debonding from the adhesive joints is the initial failure mechanism causing a progressive collapse of the blade structure. [Copyright &y& Elsevier]

Abstract: The size of wind turbine blades is expected to increase considerably in the future. Since the modern wind turbine blade is generally large-scale, faulty design production results in high expense. To achieve a desired wind turbine blade, a better understanding of the structural behavior on different scale is necessary. Although the structural deformation of the full-scale blade under various loads is an important parameter in the analysis of structural behavior and the blade’s performance, there are many difficulties in an accurate deformation measurement of the large-scale wind turbine blade. A videometric technique reported here was developed to determine the large-scale blade deformations. The technique principle and methodology will be presented in the current paper, which involves the detail of implementation in the large-scale blade deformation measurement. Some application examples with the obtained data and their analysis are presented, which demonstrates the technique’s application on large-scale wind turbine blade, and which is relevant to understanding the structural behavior of wind turbine blade in the full-scale tests and during operation. The videometric technique will be useful for structural investigation of composite wind turbine blades. A wide variety of other applications, especially those involving fieldwork, could exploit this implementation of videometric. [Copyright &y& Elsevier]

Abstract: In this study, a novel alkaliphilic extracellular endo-β-1,4-xylanase was purified from the culture filtrate of microbial community EMSD5, which could grow in liquid culture fermentation under static condition with corn stover as inducement. Single step purification was achieved using anion exchange chromatography. The purified enzyme showed a single band on SDS polyacrylamide gel electrophoresis (SDS-PAGE) with an apparent molecular weight of 22kDa and pI of 7.1. Stimulation of the activity by β-mercaptoethanol, and dithiotheritol (DTT) was observed. Moderately thermostable xylanase showed optimum activity at 50°C in pH 8.0. 16S rDNA clone library analysis indicated this community was mainly composed of bacteria related to genera Clostridium, Acinetobacter, Bacteroides, Lysinibacillus and Dysgonomonas. The present work reports for the first time the purification and characterization of an alkaliphilic xylanase from a microbial community, and the alkaliphilicity and moderate thermostability of this xylanase may have potential implications in pulp and paper industries. [Copyright &y& Elsevier]

Background: Yield and quality are the two most important traits in crop breeding. Exploring the regulatory mechanisms that affect both yield and quality traits is of great significance for understanding the molecular genetic networks controlling these key crop attributes. Expansins are cell wall loosening proteins that play important roles in regulating rice grain size. Results: We investigated the effect of OsEXPA7, encoding an expansin, on rice grain size and quality. OsEXPA7 overexpression resulted in increased plant height, panicle length, grain length, and thousand-grain weight in rice. OsEXPA7 overexpression also affected gel consistency and amylose content in rice grains, thus affecting rice quality. Subcellular localization and tissue expression analyses showed that OsEXPA7 is localized on the cell wall and is highly expressed in the panicle. Hormone treatment experiments revealed that OsEXPA7 expression mainly responds to methyl jasmonate, brassinolide, and gibberellin. Transcriptome analysis and RT-qPCR experiments showed that overexpression of OsEXPA7 affects the expression of OsJAZs in the jasmonic acid pathway and BZR1 and GE in the brassinosteroid pathway. In addition, OsEXPA7 regulates the expression of key quantitative trait loci related to yield traits, as well as regulates the expression levels of BIP1 and bZIP50 involved in the seed storage protein biosynthesis pathway. Conclusions: These results reveal that OsEXPA7 positively regulates rice yield traits and negatively regulates grain quality traits by involving plant hormone pathways and other trait-related pathway genes. These findings increase our understanding of the potential mechanism of expansins in regulating rice yield and quality traits and will be useful for breeding high-yielding and high-quality rice cultivars. [ABSTRACT FROM AUTHOR]

Background: Xylanases randomly cleave the internal β-1,4-glycosidic bonds in the xylan backbone and are grouped into different families in the carbohydrate-active enzyme (CAZy) database. Although multiple xylanases are detected in single strains of many filamentous fungi, no study has been reported on the composition, synergistic effect, and mode of action in a complete set of xylanases secreted by the same microorganism. Results: All three xylanases secreted by Penicillium chrysogenum P33 were expressed and characterized. The enzymes Xyl1 and Xyl3 belong to the GH10 family and Xyl3 contains a CBM1 domain at its C-terminal, whereas Xyl2 belongs to the GH11 family. The optimal temperature/pH values were 35 °C/6.0, 50 °C/5.0 and 55 °C/6.0 for Xyl1, Xyl2, and Xyl3, respectively. The three xylanases exhibited synergistic effects, with the maximum synergy observed between Xyl3 and Xyl2, which are from different families. The synergy between xylanases could also improve the hydrolysis of cellulase (C), with the maximum amount of reducing sugars (5.68 mg/mL) observed using the combination of C + Xyl2 + Xyl3. Although the enzymatic activity of Xyl1 toward xylan was low, it was shown to be capable of hydrolyzing xylooligosaccharides into xylose. Xyl2 was shown to hydrolyze xylan to long-chain xylooligosaccharides, whereas Xyl3 hydrolyzed xylan to xylooligosaccharides with a lower degree of polymerization. Conclusions: Synergistic effect exists among different xylanases, and it was higher between xylanases from different families. The cooperation of hydrolysis modes comprised the primary mechanism for the observed synergy between different xylanases. This study demonstrated, for the first time, that the hydrolysates of GH11 xylanases can be further hydrolyzed by GH10 xylanases, but not vice versa. [ABSTRACT FROM AUTHOR]

Background: As part of the plant microbiome, endophytic bacteria play an essential role in plant growth and resistance to stress. Water-soluble humic materials (WSHM) is widely used in sustainable agriculture as a natural and non-polluting plant growth regulator to promote the growth of plants and beneficial bacteria. However, the mechanisms of WSHM to promote plant growth and the evidence for commensal endophytic bacteria interaction with their host remain largely unknown. Here, 16S rRNA gene sequencing, transcriptomic analysis, and culture-based methods were used to reveal the underlying mechanisms. Results: WSHM reduced the alpha diversity of soybean endophytic bacteria, but increased the bacterial interactions and further selectively enriched the potentially beneficial bacteria. Meanwhile, WSHM regulated the expression of various genes related to the MAPK signaling pathway, plant-pathogen interaction, hormone signal transduction, and synthetic pathways in soybean root. Omics integration analysis showed that Sphingobium was the genus closest to the significantly changed genes in WSHM treatment. The inoculation of endophytic Sphingobium sp. TBBS4 isolated from soybean significantly improved soybean nodulation and growth by increasing della gene expression and reducing ethylene release. Conclusion: All the results revealed that WSHM promotes soybean nodulation and growth by selectively regulating soybean gene expression and regulating the endophytic bacterial community, Sphingobium was the key bacterium involved in plant-microbe interaction. These findings refined our understanding of the mechanism of WSHM promoting soybean nodulation and growth and provided novel evidence for plant-endophyte interaction. [ABSTRACT FROM AUTHOR]

RNA‐binding proteins (RBPs) are components of the post‐transcriptional regulatory system, but their regulatory effects on complex traits remain unknown. Using an integrated strategy involving map‐based cloning, functional characterizations, and transcriptomic and population genomic analyses, we revealed that RBP‐K (LOC_Os08g23120), RBP‐A (LOC_Os11g41890), and RBP‐J (LOC_Os10g33230) encode proteins that form an RBP‐A‐J‐K complex that negatively regulates rice yield‐related traits. Examinations of the RBP‐A‐J‐K complex indicated RBP‐K functions as a relatively non‐specific RBP chaperone that enables RBP‐A and RBP‐J to function normally. Additionally, RBP‐J most likely affects GA pathways, resulting in considerable increases in grain and panicle lengths, but decreases in grain width and thickness. In contrast, RBP‐A negatively regulates the expression of genes most likely involved in auxin‐regulated pathways controlling cell wall elongation and carbohydrate transport, with substantial effects on the rice grain filling process as well as grain length and weight. Evolutionarily, RBP‐K is relatively ancient and highly conserved, whereas RBP‐J and RBP‐A are more diverse. Thus, the RBP‐A‐J‐K complex may represent a typical functional model for many RBPs and protein complexes that function at transcriptional and post‐transcriptional levels in plants and animals for increased functional consistency, efficiency, and versatility, as well as increased evolutionary potential. Our results clearly demonstrate the importance of RBP‐mediated post‐transcriptional regulation for the diversity of complex traits. Furthermore, rice grain yield and quality may be enhanced by introducing various complete or partial loss‐of‐function mutations to specific RBP genes using clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR‐associated protein 9 technology and by exploiting desirable natural tri‐genic allelic combinations at the loci encoding the components of the RBP‐A‐J‐K complex through marker‐assisted selection. [ABSTRACT FROM AUTHOR]

[Display omitted] • 28 PPCPs detected with concentrations of 45.19–1453.58 ng/L in water from the Tibet. • High animal vaccine consumption is main source of PPCPs in Qinghai-Tibet Plateau. • CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounts for over 90% of the total PPCPs. • Excessive consumption of PPCPs by livestock breeding was the main emission source. • NOR, CTC, TCN, CAF, and CBZ pose high long-term ecological risks to aquatic biota. As the third pole of the world and Asia's water tower, the Tibetan Plateau experiences daily release of pharmaceutical and personal care products (PPCPs) due to increasing human activity. This study aimed to explore the potential relationship between the concentration and composition of PPCPs and human activity, by assessing the occurrence of PPCPs in areas of typical human activity on the Qinghai-Tibet Plateau and evaluating their ecological risk. The results indicate that 28 out of 30 substances were detected in concentrations ranging from less than 1 ng/L to hundreds of ng/L, with the average concentration of most PPCPs in the Tibet Autonomous Region being higher than that in Qinghai Province. Among the detected substances, CAF, NOR, CTC, CIP, TCN, OTC, AZN, and DOX accounted for over 90% of the total concentration. The emission sources of PPCPs were identified by analyzing the correlation coefficients of soil and water samples, with excess PPCPs used by livestock breeding discharged directly into soil and then into surface water through leaching or runoff. By comparing the concentration and composition of PPCPs with those in other regions, this study found that CIP, ENR, LOM, NOR, CTC, DOX, OTC, and TCN were the most commonly used PPCPs in the Qinghai-Tibet Plateau. To assess the ecological risk of PPCPs, organisms at different trophic levels, including algae, crustaceans, fish, and insects, were selected. The prediction of the no effect concentration of each PPCP showed that NOR, CTC, TCN, CAF, and CBZ may have deleterious effects on water biota. This study can assist in identifying the emission characteristics of PPCPs from different types and intensities of human activities, as well as their occurrence and fate during the natural decay of aquatic systems. [ABSTRACT FROM AUTHOR]

Amylose content (AC) is the main factor determining the palatability, viscosity, transparency, and digestibility of rice (Oryza sativa) grains. AC in rice grains is mainly controlled by different alleles of the Waxy (Wx) gene. The AP2/EREBP transcription factor OsEBP89 interacts with the MYC‐like protein OsBP5 to synergistically regulate the expression of Wx. Here, we determined that the GLYCOGEN SYNTHASE KINASE 5 (OsGSK5, also named SHAGGY‐like kinase 41 [OsSK41]) inhibits the transcriptional activation activity of OsEBP89 in rice grains during amylose biosynthesis. The loss of OsSK41 function enhanced Wx expression and increased AC in rice grains. By contrast, the loss of function of OsEBP89 reduced Wx expression and decreased AC in rice grains. OsSK41 interacts with OsEBP89 and phosphorylates four of its sites (Thr‐28, Thr‐30, Ser‐238, and Thr‐257), which makes OsEBP89 unstable and attenuates its interaction with OsBP5. Wx promoter activity was relatively weak when regulated by the phosphomimic variant OsEBP89E–OsBP5 but relatively strong when regulated by the nonphosphorylatable variant OsEBP89A–OsBP5. Therefore, OsSK41‐mediated phosphorylation of OsEBP89 represents an additional layer of complexity in the regulation of amylose biosynthesis during rice grain development. In addition, our findings provide four possible sites for regulating rice grain AC via precise gene editing. [ABSTRACT FROM AUTHOR]

Auxin is an important phytohormone in plants, and auxin signaling pathways in rice play key roles in regulating its growth, development, and productivity. To investigate how rice grain yield traits are regulated by auxin signaling pathways and to facilitate their application in rice improvement, we validated the functional relationships among regulatory genes such as OsIAA10, OsSK41, and OsARF21 that are involved in one of the auxin (OsIAA10) signaling pathways. We assessed the phenotypic effects of these genes on several grain yield traits across two environments using knockout and/or overexpression transgenic lines. Based on the results, we constructed a model that showed how grain yield traits were regulated by OsIAA10 and OsTIR1, OsAFB2, and OsSK41 and OsmiR393 in the OsSK41‐OsIAA10‐OsARF module and by OsARF21 in the transcriptional regulation of downstream auxin response genes in the OsSK41‐OsIAA10‐OsARF module. The population genomic analyses revealed rich genetic diversity and the presence of major functional alleles at most of these loci in rice populations. The strong differentiation of many major alleles between Xian/indica and Geng/japonica subspecies and/or among modern varieties and landraces suggested that they contributed to improved productivity during evolution and breeding. We identified several important aspects associated with the genetic and molecular bases of rice grain and yield traits that were regulated by auxin signaling pathways. We also suggested rice auxin response factor (OsARF) activators as candidate target genes for improving specific target traits by overexpression and/or editing subspecies‐specific alleles and by searching and pyramiding the 'best' gene allelic combinations at multiple regulatory genes in auxin signaling pathways in rice breeding programs. [ABSTRACT FROM AUTHOR]

Background: After centuries of heavy reliance on fossil fuel energy, the world suffers from an energy crisis and global warming, calling for carbon emission reduction and a transition to clean energy. Microalgae have attracted much attention as a potential feedstock for biofuel production due to their high triacylglycerol content and CO2 sequestration ability. Many diacylglycerol acyltransferases (DGAT) species have been characterized, which catalyze the final committed step in triacylglycerol biosynthesis. However, the detailed structure–function features of DGATs and the role of the interactions among DGAT proteins in lipid metabolism remained largely unknown. Results: In this study, the three characterized DGATs of Auxenochlorella protothecoides 2341 showed distinct structural and functional conservation. Functional complementation analyses showed that ApDGAT1 had higher activity than ApDGAT2b in yeast and model microalgae, and ApDGAT2a had no activity in yeast. The N-terminus was not essential to the catalysis function of ApDGAT1 but was crucial to ApDGAT2b as its enzyme activity was sensitive to any N-terminus modifications. Similarly, when acyl-CoA binding proteins (ACBPs) were fused to the N-terminus of ApDGAT1 and ApDGAT2b, zero and significant activity changes were observed, respectively. Interestingly, the ApACBP3 + ApDGAT1 variant contributed to higher oil accumulation than the original DGAT1, and ApACBP1 + ApDGAT1 fusion boosted oleic acid content in yeast. Overexpression of the three DGATs and the variation of ApACBP3 + ApDGAT1 increased the content of C18:1 of Chlamydomonas reinhardtii CC-5235. Significantly, ApDGAT1 interacted with itself, ApDGAT2b, and ApACBP1, which indicated that these three lipid metabolic proteins might have been a part of a dynamic protein interactome that facilitated the enrichment of oleic acid. Conclusions: This study provided new insights into the functional and structural characteristics of DGATs and elucidated the importance of these physical interactions in potential lipid channeling. [ABSTRACT FROM AUTHOR]

Magnetorheological elastomer (MRE) is a novel intelligent material, which shows excellent potential in vibration control applications. Previous researches have fully demonstrated that the magneto-induced shear storage modulus of MRE largely determines the vibration control effect. However, both existing theoretical and experimental ways to measure the magneto-induced shear storage modulus of MRE face their own shortage. Therefore, a novel physics-guided deep learning model is proposed to efficient predict the magneto-induced mechanical properties of MRE based on Magnetic Dipole theory and data-driven methods. A small database is built by collecting the magneto-induced shear storage modulus of MRE with different material ratios tested on a special shear rheometer. The proposed model trained with small training samples and its prediction results fit well with experimental values (average R2 of 0.99) which is superior to existing constitutive models. The training only takes 25 s, which significantly shortens the time compared to the experiment. Furthermore, the proposed model effectively predicts the magneto-induced storage modulus of MRE and has good generalization and superior transfer performance. [Display omitted] [ABSTRACT FROM AUTHOR]

It is urgent to explore new ways to protect endangered wild animals and develop sustainable animal husbandry on the Qinghai–Tibet Plateau due to its fragile ecological environment. Ruminants, raised in captivity and free-range, have important niches in the Plateau and are the best models to analyze the effects of different feeding modes on their health. In this study, two ruminants, yaks and goats in free-range and captive modes, respectively, were selected to study the relationship between gut microbes and ruminant health. The results showed that the gut microbial diversity of free-range ruminants was higher than those of captive ruminants. Principal co-ordinates analysis (PCoA) showed that there were significant differences in the gut microbial communities in different breeding modes. Both the captive ruminants enriched the Succinivibrionaceae family, which had a strong potential to synthesize lipopolysaccharide, and the low exercise amount of the captive animals was significantly related to this function. Meanwhile, free-range ruminants enriched Oscillospiraceae, which had the potential to degrade benzoic acid, and this potential had a significant positive correlation with resistance to parasitic infections. We offer other possibilities, such as adding benzoic acid to feed or increasing the exercise time of captive ruminants to make them healthier. [ABSTRACT FROM AUTHOR]

The geomorphologic and environmental evolution of the Loess Plateau is greatly affected by the strong fault activity, leading to the frequent occurrence of geological hazards, particularly the loess-mudstone landslide (LML). Thus, it is crucial to investigate the formation mechanism of such landslides in active fault zones. In this study, a field survey was conducted in the Weibei tableland of Baoji where the active fault zone is developed. To study the creep behavior of LML sliding zone soil, the triaxial creep tests of multi-stage loading under different water content, confining pressure, dry density, loess-mudstone binary structure (LMBS) contact surface angle, and thickness were carried out using the sliding zone soil samples (loess, mudstone, and LMBS samples) obtained from Wolongsi landslide in the study area as an example. Experimental results revealed that: (1) Water content has a significant weakening effect on the strength of LML sliding zone soil. The strength of the LMBS sample is extremely water-sensitive. The weakening effect of water on the long-term strength of LML sliding zone soil mainly manifested in promoting the elastoplastic deformation of loess and the viscoplastic deformation of mudstone. (2) The long-term strength of the LML slip zone soil increases linearly with the increase in confining pressure and increases exponentially with the dry density. (3) The degrading effect of the stratigraphic interface dip angle on the long-term slope strength is mainly reflected in the change in the weakening degree of water on the strength of the LML sliding zone. In addition, according to the test results, the traditional Nishihara model is improved by introducing nonlinear parameters, and a new constitutive equation describing LML sliding zone soil is established. The new constitutive model can accurately describe the creep curve's whole process especially sensitively identifying the accelerated creep stage. Finally, after conducting a field investigation and laboratory tests, the main hazard factors affecting the occurrence of the LML were analyzed in the presence of fault activity on the Weibei Plateau of Baoji, China, and its formation mechanism was revealed as well. [ABSTRACT FROM AUTHOR]

Background: Both APETALA2/Ethylene Responsive Factor (AP2/ERF) superfamily and R2R3-MYB family were from one of the largest diverse families of transcription factors (TFs) in plants, and played important roles in plant development and responses to various stresses. However, no systematic analysis of these TFs had been conducted in the green algae A. protothecoides heretofore. Temperature was a critical factor affecting growth and lipid metabolism of A. protothecoides. It also remained largely unknown whether these TFs would respond to temperature stress and be involved in controlling lipid metabolism process. Results: Hereby, a total of six AP2 TFs, six ERF TFs and six R2R3-MYB TFs were identified and their expression profiles were also analyzed under low-temperature (LT) and high-temperature (HT) stresses. Meanwhile, differential adjustments of lipid pathways were triggered, with enhanced triacylglycerol accumulation. A co-expression network was built between these 18 TFs and 32 lipid-metabolism-related genes, suggesting intrinsic associations between TFs and the regulatory mechanism of lipid metabolism. Conclusions: This study represented an important first step towards identifying functions and roles of AP2 superfamily and R2R3-MYB family in lipid adjustments and response to temperature stress. These findings would facilitate the biotechnological development in microalgae-based biofuel production and the better understanding of photosynthetic organisms' adaptive mechanism to temperature stress. [ABSTRACT FROM AUTHOR]

The modification of tRNA is important for accurate, efficient protein translation. A number of tRNA-modifying enzymes were found to influence various developmental processes in distinct organisms. However, few genetic or molecular studies have focused on genes encoding tRNA-modifying enzymes in green plant organelles. Here, we discovered that PDD OL , a natural variation allele of PLEIOTROPIC DEVELOPMENTAL DEFECTS (PDD), leads to pleiotropic developmental defects in a near-isogenic line (NIL) generated by introgressing the wild rice Oryza longistaminata into the rice (Oryza sativa) cv 187R. Map-based cloning revealed that PDD encodes an evolutionarily conserved tRNA-modifying GTPase belonging to the tRNA modification E family. The function of PDD was further confirmed by genetic complementation experiments and mutant analysis. PDD mRNA is primarily expressed in leaves, and PDD is localized to chloroplasts. Biochemical analyses indicated that PDD187R forms homodimers and has strong GTPase activity, whereas PDDOL fails to form homodimers and has weak GTPase activity. Liquid chromatography–coupled tandem quadrupole mass spectrometry revealed that PDD is associated with the 5-methylaminomethyl-2-thiouridine modification of chloroplast tRNA. Furthermore, compared to 187R, NIL- PDD OL has severely reduced levels of proteins involved in photosynthesis and ribosome biogenesis but increased levels of plastid-encoded RNA polymerase subunits. Finally, we demonstrate that the defect due to PDD OL alters chloroplast gene expression, thereby affecting communication between the chloroplast and the nucleus. [ABSTRACT FROM AUTHOR]

Objectives. Ankylosing spondylitis (AS) is a chronic disease that decreases mobility, function, and quality of life. This study introduced the "Smart-phone SpondyloArthritis Management System" (SpAMS), an interactive mobile health (mHealth) tool designed for AS/spondyloarthritis (SpA) disease management and used SpAMS data to evaluate clinical characteristics of Chinese patients with AS. Methods. SpAMS integrates patient's and physician's portals in a smart phone application. The Chinese Ankylosing Spondylitis Prospective Imaging Cohort was launched using SpAMS in April 2016. Patient self-assessments were completed online at baseline and at every subsequent clinic visit. Physician-reported assessments and treatments were recorded by rheumatologists during each visit. Results. In total, 1201 patients with AS [mean (SD) age, 30.6 (8.7) years; male, 82.6%] were recruited. Mean (SD) disease duration was 8.4 (6.1) years. Past or current symptoms of acute anterior uveitis (AAU), psoriasis, and inflammatory bowel disease (IBD) were observed in 21.0%, 3.7%, and 9.4% of patients, respectively. AAU and IBD occurred significantly more in patients with symptom duration > 10 years. The most commonly used medications at baseline were nonsteroidal anti-inflammatory drugs (98.2%). Patients using tumour necrosis factor inhibitors accounted for 20.8%, and 66.4% of patients used conventional synthetic disease-modifying antirheumatic drugs. At baseline, 57.2% of patients had inactive disease (ID)/low disease activity (LDA); this rate significantly improved to 79.2% after a mean follow-up of 13.3 (5.9) months. Compared with relapsed patients, new achievers of ID/LDA underwent more online patient assessments (P < .001). Problems solved in SpAMS caused 29.1% of clinic visits to a tertiary hospital unnecessary. SpAMS saved an average of 5.3 hours and 327.4 RMB per person on traffic expenses; these expenses equalled 16% of the Chinese monthly disposable personal income. Conclusions. SpAMS is a time- and cost-saving disease management tool that can help patients with AS perform self-management and provide valuable data to clinicians. [ABSTRACT FROM AUTHOR]

Grain size and shape are important determinants of grain weight and yield in rice. Here, we report a new major quantitative trait locus (QTL), q TGW3 , that controls grain size and weight in rice. This locus, q TGW3 , encodes OsSK41 (also known as OsGSK5), a member of the GLYCOGEN SYNTHASE KINASE 3/SHAGGY-like family. Rice near-isogenic lines carrying the loss-of-function allele of Os SK41 have increased grain length and weight. We demonstrate that OsSK41 interacts with and phosphorylates AUXIN RESPONSE FACTOR 4 (OsARF4). Co-expression of Os SK41 with Os ARF4 increases the accumulation of OsARF4 in rice protoplasts. Loss of function of Os ARF4 results in larger rice grains. RNA-sequencing analysis suggests that Os ARF4 and Os SK41 repress the expression of a common set of downstream genes, including some auxin-responsive genes, during rice grain development. The loss-of-function form of Os SK41 at q TGW3 represents a rare allele that has not been extensively utilized in rice breeding. Suppression of Os SK41 function by either targeted gene editing or QTL pyramiding enhances rice grain size and weight. Thus, our study reveals the important role of OsSK41 in rice grain development and provides new candidate genes for genetic improvement of grain yield in rice and perhaps in other cereal crops. [ABSTRACT FROM AUTHOR]

Temperature is a crucial factor affecting microalgae CO 2 capture and utilization. However, an in-depth understanding of how microalgae respond to temperature stress is still unclear. In particular, the regulation mechanism under opposite temperature (heat and cold) stress had not yet been reported. In this study, the physicochemical properties and transcription level of related genes of microalgae Auxenochlorella protothecoides UTEX 2341 under heat and cold stress were investigated. Heat stress (Hs) caused a drastic increase of reactive oxygen species (ROS) in UTEX 2341. As key elements responded to Hs, superoxide dismutase (SOD) enzyme increased by 150%, 70%, and 30% in activity, and nitric oxide (NO) grew by 409.6%, 212.5%, and 990.4% in content compared with the control at 48 h, 96 h, 168 h. Under cold stress (Cs), ROS increased in the early stage and decreased in the later stage. As key factors responded to Cs, proline (Pro) increased respectively by 285%, 383%, and 81% in content, and heat shock transcriptional factor HSFA1d increased respectively by 161%, 71%, and 204% in transcript level compared with the control at 48 h, 96 h, 168 h. Furthermore, the transcript level of antioxidant enzymes or antioxidant coding genes was consistent with the changing trend of enzymes activity or antioxidant content. Notably, both glutathione (GSH) and heat shock protein 97 (hsp 97) were up-regulated in response to Hs and Cs. In conclusion, GSH and hsp 97 were the core elements of UTEX 2341 in response to both Hs and Cs. SOD and NO were the key elements that responded to Hs, while proline and HSFA1d were the key elements that responded to Cs. This study provided a basis for the understanding of the response mechanism of microalgae under temperature stress and the improvement of the microalgae tolerance to temperature stress. • Glutathione and hsp 97 were the core factors in algae responded to temperature stress. • Proline and HSFA1d were the key factors in algae responded to cold stress. • SOD and NO were the key factors in algae responded to heat stress. • A suggested working model of microalgae for cold/heat-resistance was constructed. [ABSTRACT FROM AUTHOR]

Paenibacillus sp. strain A2 is a Gram-negative rod-shaped bacterium isolated from a mixture of formation water and petroleum in Daqing oilfield, China. This facultative aerobic bacterium was found to have a broad capacity for metabolizing hydrocarbon and organosulfur compounds, which are the main reasons for the interest in sequencing its genome. Here we describe the features of Paenibacillus sp. strain A2, together with the genome sequence and its annotation. The 7,650,246 bp long genome (1 chromosome but no plasmid) exhibits a G+C content of 54.2 % and contains 7575 protein-coding and 49 RNA genes, including 3 rRNA genes. One putative alkane monooxygenase, one putative alkanesulfonate monooxygenase, one putative alkanesulfonate transporter and four putative sulfate transporters were found in the draft genome. [ABSTRACT FROM AUTHOR]

A finite element model for a composite T-joint structure under tensile loading has been established to simulate and analyze failure mechanisms, carrying capacities, in-plane and interlaminar damage behaviors based on the Tsai-Wu failure criterion and a cohesive zone model. Strains on the stress-concentration zone of the T-joint structure during loading were measured to validate the FEM model. The results showed that the simulated results had a good agreement with that of the measurements. The carrying capacity of the composite T-joint is mainly determined by failure modes, which can be changed by reducing fillet-filling ratio in the fillet of the T-joint and initiation and propagation paths of delamination cracks between the fillet and the L-ribs. The maximum tensile load of the T-joint calculated by FEM methods was 1854N, while the experimental value was 1862N. [ABSTRACT FROM AUTHOR]

In recent years, yak milk has received widespread attention due to its high nutrition, green and pollution-free characteristics, but the source of yak milk flavor is still unclear. In this study, fresh yak manure collected from Lhasa, Nagqu, Qamdo, Yushu, and Qinghai Lake were sequenced by 16S rRNA gene high-throughput sequencing technology. The correlation between intestinal microbiota and yak milk quality combined with the local environmental factors was evaluated for the first time. The enterotype of yaks from Lhasa, Nagqu, and Qinghai Lake was classified as enterotype of norank_f_Oscillospirales_UCG-010 and Rikenellaceae_ RC9_gut_group , and the enterotype of yaks from Qamdo and Yushu was classified as enterotype of Oscillospiraceae UCG-005. Procrustes analysis showed that there was a close relationship between yak milk composition and intestinal microbiota. Metabolic pathway analysis found that different genera and key enzymes of methane and short-chain fatty acid metabolic pathways differed in their responses to environmental factors. Based on the above analysis, a model about environmental factors, intestinal bacteria and the flavor of yak milk was developed. The results provided a reference for the study of flavor substances in yak milk and a new direction for the improvement of dairy products and their derivatives. • The yak gut microbial diversity of southeastern Tibet-Qinghai Plateau is studied. • The yak is divided into Enterotype 1 and Enterotype 2 according to its gut microbes. • Stable enterotype is the basis for the function of different genera in the gut. • Yak milk flavor is closely related to gut microbes and local environmental factors. • A model based on enterotype to influence the flavor of yak milk is constructed. [ABSTRACT FROM AUTHOR]

Abstract: Bending properties and failure modes of carbon fiber composite egg and pyramidal honeycomb beams were studied and presented in this paper. Three point bending responses of both sandwich beams were tested. Face wrinkling, face crushing, core member crushing and debonding were considered, and theoretical relationships for predicting the failure load associated with each mode were presented under three point bending load. Failure mechanism maps were constructed to predict the failure of composite sandwich beams with pyramidal and egg honeycomb cores subjected to bending. Face wrinkling and core debonding have been investigated under three point bending and the maximum displacement was studied using analytical and experimental methods. The finite element method was employed to determine the ratio (maximum displacement/applied load) of sandwich beam with two different honeycomb cores. Comparisons between two kinds of honeycomb beams were also conducted. [Copyright &y& Elsevier]

Abstract: In this paper, the polyurethane foam filled pyramidal lattice core sandwich panel is fabricated in order to improve the energy absorption and low velocity impact resistance. Based on the compression tests, a synergistic effect that the foam filled sandwich panels have a greater load carrying capacity compared to the sum of the unfilled specimens and the filled polyurethane block is found. Moreover, the energy absorption efficiency of foam filled sandwich panels with higher relative density (2.58% and 3.17%) lattice cores is lower than that of the unfilled specimens when the compressive strain is small, while it exhibits superior when the compressive strain arrives at about 0.25, and the superiority enlarges as the strain increase. However, the energy absorption of foam filled sandwich panels owning lower relative density (1.83%) lattice cores is inferior to that of the unfilled specimens. During the low velocity impact tests, it is found that the contact duration between the impactor and the sandwich specimens is shorter and the impact peak load has a slight increase for the foam filled specimens. [Copyright &y& Elsevier]

Common wild rice ( Oryza rufipogon Griff.) is an important genetic reservoir for rice improvement. We investigated a quantitative trait locus (QTL), qGP5-1, which is related to plant height, leaf size and panicle architecture, using a set of introgression lines of O. rufipogon in the background of the Indica cultivar Guichao2 ( Oryza sativa L.). We cloned and characterized qGP5-1 and confirmed that the newly identified gene OsEBS (enhancing biomass and spikelet number) increased plant height, leaf size and spikelet number per panicle, leading to an increase in total grain yield per plant. Our results showed that the increased size of vegetative organs in OsEBS-expressed plants was enormously caused by increasing cell number. Sequence alignment showed that OsEBS protein contains a region with high similarity to the N-terminal conserved ATPase domain of Hsp70, but it lacks the C-terminal regions of the peptide-binding domain and the C-terminal lid. More results indicated that OsEBS gene did not have typical characteristics of Hsp70 in this study. Furthermore, Arabidopsis ( Arabidopsis thaliana) transformed with OsEBS showed a similar phenotype to OsEBS-transgenic rice, indicating a conserved function of OsEBS among plant species. Together, we report the cloning and characterization of OsEBS, a new QTL that controls rice biomass and spikelet number, through map-based cloning, and it may have utility in improving grain yield in rice. [ABSTRACT FROM AUTHOR]

Abstract: A combined experimental and numerical study is conducted to assess the effects of impact energy, impact site and core density on the compression-after-impact (CAI) strength of pyramidal truss core sandwich structures. It is found that the severity of impact damage highly depends on the impact site. The CAI tests show that the local buckling occurs for both the un-impact specimens and the specimens impacted under lower energy, while debonding is observed for the specimens impacted under higher energy. In case of the specimens impacted on the middle point of the four adjacent nodes, only a crack appears in the impact-damaged facesheet, which propagates transversely across the facesheet. It is observed that the CAI strength of specimens impacted on the middle point of four adjacent nodes drop much more than that of specimens impacted on the node, and that the specimens with higher density cores have slightly lower normalized CAI strength reduction. Moreover, it is found that the CAI strength of specimens impacted on the node decreases with the impact energy increasing. In addition to experimental tests, the numerical simulation performs well in capturing the failure modes for impact-damaged specimens under compressive load. [Copyright &y& Elsevier]

Developing methods for increasing the biomass and improving the plant architecture is important for crop improvement. We herein describe a gene belonging to the RING_Ubox (RING (Really Interesting New Gene) finger domain and U-box domain) superfamily, PLANT ARCHITECTURE and GRAIN NUMBER 1 (PAGN1), which regulates the number of grains per panicle, the plant height, and the number of tillers. We used the CRISPR/Cas9 system to introduce loss-of-function mutations to OsPAGN1. Compared with the control plants, the resulting pagn1 mutant plants had a higher grain yield because of increases in the plant height and in the number of tillers and grains per panicle. Thus, OsPAGN1 may be useful for the genetic improvement of plant architecture and yield. An examination of evolutionary relationships revealed that OsPAGN1 is highly conserved in rice. We demonstrated that OsPAGN1 can interact directly with OsCNR10 (CELL NUMBER REGULATOR10), which negatively regulates the number of rice grains per panicle. A transcriptome analysis indicated that silencing OsPAGN1 affects the levels of active cytokinins in rice. Therefore, our findings have clarified the OsPAGN1 functions related to rice growth and grain development. [ABSTRACT FROM AUTHOR]

A dwarf mutant, designated LB4D, was obtained among the progeny of backcrosses to a wild rice introgression line. Genetic analysis of LB4D indicated that the dwarf phenotype was controlled by a single semidominant dwarfing gene, which was named LB4D. The mutants were categorized as dn‐type dwarf mutants according to the pattern of internode reduction. In addition, gibberellin (GA) response tests showed that LB4D plants were neither deficient nor insensitive to GA. This study found that tiller formation by LB4D plants was decreased by 40% compared with the wild type, in contrast to other dominant dwarf mutants that have been identified, indicating that a different dwarfing mechanism might be involved in the LB4D dominant mutant. The reduction of plant height in F1 plants ranged from 27.9% to 38.1% in different genetic backgrounds, showing that LB4D exerted a stronger dominant dwarfing effect. Using large F2 and F3 populations derived from a cross between heterozygous LB4D and the japonica cultivar Nipponbare, the LB4D gene was localized to a 46 kb region between the markers Indel 4 and Indel G on the short arm of chromosome 11, and four predicted genes were identified as candidates in the target region. [ABSTRACT FROM AUTHOR]

In rice ( Oryza sativa L.), the number of panicles, spikelets per panicle and grain weight are important components of grain yield. These characteristics are controlled by quantitative trait loci (QTLs) and are derived from variation inherent in crops. As a result of the complex genetic basis of these traits, only a few genes involved in their control have been cloned and characterized. We have previously map-cloned a gene cluster including eight leucine-rich repeat receptor-like kinase ( LRK) genes in Dongxiang wild rice ( Oryza rufipogon Griff.), which increased the grain yield by 16%. In the present study, we characterized the LRK1 gene, which was contained in the donor parent (Dongxiang wild rice) genome and absent from the recurrent parent genome (Guichao2, Oryza sativa L. ssp. indica). Our data showed that rice LRK1 is a plasma membrane protein expressed constitutively in leaves, young panicles, roots and culms. The over-expression of rice LRK1 results in increased panicles, spikelets per panicle, weight per grain and enhanced cellular proliferation, leading to a 27.09% increase in total grain yield per plant. The increased number of panicles and spikelets per panicle are associated with increased branch number. Our data suggest that rice LRK1 regulates rice branch number by enhancing cellular proliferation. The functional characterization of rice LRK1 facilitates an understanding of the mechanisms involved in cereal crop yield, and may have utility in improving grain yield in cereal crops. [ABSTRACT FROM AUTHOR]

A set of 148 F9 recombinant inbred lines (RILs) was developed from the cross of an indica cultivar 93-11 and japonica cultivar DT713, showing strong F1 heterosis. Subsequently, two backcross F1 (BCF1) populations were constructed by backcrossing these 148 RILs to two parents, 93-11 and DT713. These three related populations (281BCF1 lines, 148 RILs) were phenotyped for six yield-related traits in two locations. Significant inbreeding depression was detected in the population of RILS and a high level of heterosis was observed in the two BCF1 populations. A total of 42 main-effect quantitative trait loci (M-QTLs) and 109 epistatic effect QTL pairs (E-QTLs) were detected in the three related populations using the mixed model approach. By comparing the genetic effects of these QTLs detected in the RILs, BCF1 performance and mid-parental heterosis ( HMP), we found that, in both BCF1 populations, the QTLs detected could be classified into two predominant types: additive and over-dominant loci, which indicated that the additive and over-dominant effect were more important than complete or partially dominance for M-QTLs and E-QTLs. Further, we found that the E-QTLs detected collectively explained a larger portion of the total phenotypic variation than the M-QTLs in both RILs and BCF1 populations. All of these results suggest that additive and over-dominance resulting from epistatic loci might be the primary genetic basis of heterosis in rice. [ABSTRACT FROM AUTHOR]

The static/dynamic compressive performances of sandwich panels with density gradient lattice core were investigated by experimental and numerical methods. A three-layer stainless steel lattice sandwich panel was proposed, and the density gradient between core layers of the sandwich panels was achieved by varying the cross-sectional dimensions of truss bar of each layer. A large diameter Hopkinson pressure bar device was employed to carried out the dynamic impact experiment. The three-dimension finite element method was used to investigate the effects of gradient scheme of core layers and the impact velocity on the structural response. The results reveal that, there exists different failure mechanism between non-gradient lattice sandwich panels and gradient lattice sandwich panels, and the ABC gradient configuration is optimal due to its higher impact strength and better energy absorption capacity at a higher impact velocity which can buckle the truss bars of all layers of gradient lattice sandwich panel. [ABSTRACT FROM AUTHOR]

• Poor mechanical robustness still hinders water repellent coatings for application. • Natural weakness of nanoscale structures causes poor mechanical robustness. • Inverse infusion process creates much stronger micro/nano hybrid structures. • Newly synthesized epoxy enhances both water repellency and mechanical strength. • Water repellent coatings with comprehensive robustness in very harsh conditions. Poor mechanical durability still hinders artificial superhydrophobic coatings from practical application, although these coatings were created years ago and still attract wide research interest. Previous epoxy/nanoparticle works seem to encounter a dilemma: a delicate nanostructure and low surface energy without a proper and strong microstructure to provide protection and strength naturally leads to weak mechanical adhesion and poor wear robustness. Herein, we develop an inverse infusion process (IIP) to construct hierarchical structures via newly synthesized hydrophobic and tough epoxy resin as well as rationally selected alumina nanoparticles (NPs). The IIP process forms an uncured epoxy layer first on the substrate and a preliminary nanocomposite coating next using an air spraying method, after which the epoxy layer inversely infuses into the micro/nanostructure and constructs a tougher microstructure on the top as well as a continuous nanocomposite layer throughout the coating after curing. This results in superhydrophobic coatings on a substrate with excellent adhesion and mechanical robustness, and our coatings can tolerate 600 cycles of tape peeling tests (with 3 M high-tack tape), 20 m sandpaper abrasion (with a pressure of ~5 kPa and 80 grit sandpaper), 115 cycles of Taber abrasion (with 250 g load), and 600 g of sand impact from a height of 110 cm, which are the highest values achieved by superhydrophobic coatings to the best of our knowledge. Furthermore, our coatings sustained highly corrosive media, such as sodium hydroxide and hydrochloric acid solutions. A combination of the established IIP process and the rationally selected ingredients dramatically enhanced the mechanical durability of the superhydrophobic coatings, and these attractive materials may attract attention for self-cleaning, anti-icing, and anti-fouling applications in industry. [ABSTRACT FROM AUTHOR]