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The time-integrated polarization degree (PD) in the prompt optical band of a gamma-ray burst (GRB) was predicted to be less than 20%, while the time-resolved one can reach as high as 75% in the photosphere model. Polarizations in the optical band during the GRB prompt phase have not previously been studied in the framework of the magnetic reconnection model. Here, a three-segment power law of the energy spectrum is used to reconstruct the Stokes parameters of the magnetic reconnection model. Multiwavelength light curves and polarization curves from the optical band to MeV gamma rays in the GRB prompt phase are studied. We found that, depending mainly on the jet dynamics, there is a long-lasting high-PD phase in all calculated energy bands for the typical parameter sets. The time-resolved PD could be as high as 50%, while the time-integrated one is roughly 17% in the optical band. The time-resolved PD in X-rays can reach 60% and the time-integrated one is around 30%–40%. The evolution of polarization angle (PA) is random in both optical and gamma-ray bands for the photosphere model, while it is roughly constant in the synchrotron models. Therefore, future time-resolved PA observations in the prompt optical or gamma-ray band could distinguish between the photosphere and synchrotron models. [ABSTRACT FROM AUTHOR]

In previous studies, the time evolution information is missed in deducing the time-integrated polarizations of gamma-ray burst prompt emission. Here, it is considered and the time-integrated polarizations is investigated through the summation of the time-resolved ones. The statistical properties of the distribution of the time-integrated polarization degree (Π) can be read from the q– Π curve, where q ≡ θ V /θ j . θ V and θ j are the observational and jet half-opening angles, respectively. Hence, only the q– Π curves are studied. In addition to a toroidal magnetic field in the radiation region, an aligned field is also discussed. We found the predicted time-integrated polarization degree is around |$(40\!-\!50)\,\, \mathrm{ per\,cent}$| for High-energy Polarimetry Detector (HPD) onboard POLAR-2 and is roughly |$(30\!-\!40)\,\, \mathrm{ per\,cent}$| for its Low-energy Polarimetry Detector (LPD). Therefore, Π value detected by the HPD will be larger than that of the LPD in statistics and the result of the former estimations will underestimate the value of Π in an ordered field. There are mainly two types of the q –Π curve profiles, corresponding to two ordered magnetic field configurations. [ABSTRACT FROM AUTHOR]

The environment of a γ -ray burst has an important influence on the evolution of jet dynamics and its afterglow. Here we investigate the afterglow polarizations in a stratified medium with the equal arrival time surface (EATS) effect. Polarizations of multiband afterglows are predicted. The effects of the parameters of the stratified medium on the afterglow polarizations are also investigated. We found the influences of the EATS effect on the afterglow polarizations become important for off-axis detections and polarization degree (PD) bumps move to later times with the EATS effect. Even if the magnetic field configurations, jet structure, and observational angles are fixed, polarization properties of the jet emission could still evolve. Here, we assume a large-scale ordered magnetic field in the reverse-shock region and a two-dimensional random field in the forward-shock region. Then, PD evolution is mainly determined by the evolution of the f 32 parameter (the flux ratio between the reverse-shock region and forward-shock region) at the early stage and by the evolution of the bulk Lorentz factor γ at the late stage. Through the influences on the f 32 or γ, the observational energy band, observational angles, and the parameters of the stratified medium will finally affect the afterglow polarizations. [ABSTRACT FROM AUTHOR]

The rotations of the polarization angle (PA) with time (energy) can lead to the depolarization of the time-integrated (energy-integrated) polarization. However, we do not know how and when it will rotate. Here, we consider a magnetic reconnection model to investigate the polarizations, especially the PA rotations of gamma-ray burst (GRB) prompt emission. For a large-scale ordered aligned magnetic field configuration, we find that within T 50 PAs will rotate with time (energy) for slight off-axis observations. Our studies show that the rotations of the PAs are due to changes in the observed image of the emitting region before being averaged over the equal arrival time surface for the unresolved sources. We apply our model to the single-pulse bursts of GRB 170101A and GRB 170114A with time-resolved PA observations. We find it can interpret the violent PA variation of GRB 170101A, while the model could not predict the two 90° PA changes in GRB 170114A. A more detailed model should be considered. [ABSTRACT FROM AUTHOR]

In addition to the light curve and energy spectrum, polarization is also important for inferring the physical properties of the gamma-ray burst (GRB). Rotation of the polarization angle (PA) with time will cause depolarization of the time-integrated polarization degree. However, it has rarely been studied before. Here, we use a magnetic reconnection model with a large-scale ordered aligned magnetic field in the emitting region to study the influence of the parameters on the PA rotations in the GRB prompt phase. We find that the half-opening angle of the jet θ j , the observational angle θ V , and the bulk Lorentz factor Γ all have significant impacts on the PA rotations. The PA rotations are affected by the product value of θ j Γ0 (Γ0 is the normalization factor of Γ with Γ (r) = Γ 0 (r / r 0) s ), but are roughly independent of the concrete values of both θ j and Γ0. For the typical parameters, the changes of the PA within T 90 (△PA) would be within (12°, 66°) for slight off-axis observations, where T 90 is the duration of the burst with the accumulated flux density ranging from 5% to 95%. The q range for △PA > 10° becomes smaller with the increase of the product value of θ j Γ0. The most significant PA rotation with △PA ∼ 90° will happen when θ j Γ0 > 50 and 1.0 < q ≤ 1.2. [ABSTRACT FROM AUTHOR]

• Keratin filaments were developed from poultry feather wastes. • Dual-functional dithiols endow filaments with higher ductility than feathers. • Filament regeneration potentially creates more than 100-billion-dollar revenue. • Poultry wastes can be substantially reduced. Technology for the transformation of waste feathers to quality regenerated filaments has been developed. Regardless of superior properties of natural keratin materials, previously developed regenerated materials from keratin had tensile properties much lower than their natural counterparts due to backbone hydrolysis and inefficient reconstruction of disulfide crosslinkages. In this work, tough keratin filaments have been regenerated from white duck feathers via efficient restoration of disulfide crosslinkages using a dithiol reducing agent. Dithiol substantially reserves free thiol groups in the extraction and formed lengthy intermolecular crosslinkages in regenerated keratin filaments. Due to the high degree of intermolecular reconstruction of disulfide bonds and formation of lengthy crosslinkages via dithiol chain-extension, the keratin filaments exhibited considerable improvements in mechanical properties, especially for ductility and water stability. The tenacity and elongation at break were 160.7 MPa and 14%, respectively. The filaments retained about 80% of the tenacity of natural feathers at either dry or wet conditions and demonstrated stretchability 150% higher than natural feathers. The fiber regeneration technology makes it possible to substitute primary fiber sources by renewable poultry feathers. Successful filament substitution or addition can bring more than 88-billion-dollar revenue. The technology not only contributes to a sustainable fiber and poultry industry but adds substantial values to poultry feathers. [ABSTRACT FROM AUTHOR]

• Keratin films were reinforced by interfacially-compatible nano-cysteine particles. • Cysteine particles with smaller sizes showed better reinforcing effects. • The keratin composite films were tough, pliant and stable in high humidity. • Keratin composite films demonstrated good biocompatibility in vitro study. Keratin films with wet stability and strength suitable for biomedical applications were developed via reinforcement with submicron cysteine particles for improved interfaces. Keratin products regenerated from wool or human hair were widely investigated as wound dressing and tissue engineering scaffolds for their satisfactory biomedical properties. However, regenerated keratin scaffolds usually did not have good mechanical properties, and also could not stand humid or wet biological environment due to poor moisture stability. Reinforcements for keratin materials were usually polysaccharides or synthetic polymers, and thus usually had non-ideal interfacial properties due to limited compatibility. In this research, submicron cystine particles were employed to reinforce keratin films for their high compatibility with keratin and bio-safety. Transition of primary and secondary structures of keratin due to matrix-reinforcement interaction was analyzed. The keratin films showed unprecedented pliancy, good tensile properties under humid conditions and biocompatibility, and thus had good potential for biomedical engineering applications. [ABSTRACT FROM AUTHOR]

• The ultimate load-carrying capacity tests were carried out on the curved CFRP thin-walled pipe truss. • Linear and non-linear buckling analysis of the structure. • Methods for the introduction of initial geometric imperfections were investigated. • Parametric analysis of the ply orientation was carried out. This paper investigates the stability performance of a large-scale carbon fiber reinforced composite (CFRP) truss used in the keel structure of a stratospheric airship. An ultimate load-bearing test was performed on an approximately 4 m long curved CFRP thin-walled pipe truss, which was reduced to sliding supports at both ends to simulate force conditions in the normal service phase. A modified initial geometric imperfection (GI) simulation method was employed to conduct a linear and nonlinear finite element (FE) buckling analysis of the structure, considering the composite lay-up of the thin-walled pipe. Parametric analysis studies were also conducted to improve simulation accuracy and lightweight design. Results show that the structure exhibits linear behavior under the ultimate load level, with failure occurring at the span position of the lower chord. The FE model predicts the ultimate load capacity and stiffness of the structure accurately, and the parametric analysis reveals the significance of choosing a reasonable imperfection form and amplitude for the FE analysis, as well as the significant effect of ply orientation on structural performance. This study provides valuable insights into the design and optimization of CFRP trusses used in the keel structure of stratospheric airships. [ABSTRACT FROM AUTHOR]

• A new large-scale modular CFRP wheel-spoke-shaped stiffening ring is proposed. • A CFRP wheel-spoke-shaped stiffening ring with a diameter of 40.0 m was integrated through modular assembly technology. • The buckling failure position and buckling load of the CFRP wheel-spoke-shaped stiffening ring are determined by a multi-point loading static stability test. • A refined multi-layered shell model based on the combined eigenmode imperfection method is proposed and established. To enhance the hoop stiffness of the rigid-flexible integrated airship, a new large-scale wheel-spoke-shaped stiffening ring composed of modular carbon fiber reinforced polymer (CFRP) standard trusses was designed in this work. Particularly, by using the modular assembly technology, the CFRP stiffening ring with a diameter of 40.0 m was integrated assembly, which verified the feasibility of the proposed structural design method. Based on the applied uniformly distributed load form of the CFRP wheel-spoke-shaped stiffening ring during the flight of the rigid-flexible integrated airship, the standard truss module was subjected to a multi-point loading static stability test through a self-developed loading device, while the in-plane buckling failure position and buckling load of the CFRP wheel-spoke-shaped stiffening ring were also determined. Based on the refined multi-layered shell model, the combined eigenmode imperfection method was used for the nonlinear buckling analysis of the CFRP truss module. The buckling failure mode and the buckling load obtained from the simulation results were in good agreement with the test results. The proposed and verified large-scale modular CFRP wheel-spoke-shaped stiffening ring improved the hoop stiffness of the rigid-flexible integrated airship and achieved structural weight reduction and the design goal of the large-scale structure. The refined multi-layered shell model based on the combined eigenmode imperfection method has an important application value and guiding significance for investigating the buckling property of CFRP wheel-spoke-shaped stiffening rings, which provides valuable technical support for the structural design of rigid-flexible integrated airships. [ABSTRACT FROM AUTHOR]

The Asian hydroclimate variability during the early and middle Marine Isotope Stage (MIS) 3 was reconstructed from a high-resolution stalagmite δ18O record from Qixing Cave in southern China, which exhibited an extraordinarily strong precessional cycle. When compared with other cave records (mostly) from East Asia, covering a latitudinal transect from 23° to 38°N, it can be found that the magnitude of precessional-scale stalagmite δ18O variations decreases when the latitude increases, approximately from 3‰ to 1‰. In contrast, the amplitude of Heinrich stadials (HSs) in these stalagmite δ18O records enhances with increasing latitudes, from 1‰ to 2‰, reflecting an alleviated effect of high-latitude climate changes on the low-latitude hydroclimate, or a relative contribution from Westerlies-borne and near-sourced 18O-enriched moisture at northern China. In southern China, orbital-scale changes in stalagmite δ18O closely match variations of the atmospheric CH 4 concentration and δ18O of the atmospheric O 2 , suggesting a coherent response of low-latitude ecological and hydrological processes. In addition, a weaker precessional cycle in northern China is possibly related to the relative supply of near-sourced moisture source, where the Westerly wind can exert a substantial role. Therefore, precessional to millennial-scale changes in East Asian stalagmite δ18O records could be further modulated by local processes, rendering them a spatially contrasting trait. A pervasive imprint of muted precessional rainfall changes in loess records from northern China suggests a regionally distinct rhythm of moisture availability, in agreement with the stalagmite records from higher latitudes. • An increase of HS amplitude but weakening of the precessional cycle with increasing latitudes. • The role of low-latitude processes on alleviating the HS amplitude in southern China. • A dividing role of the latitudinal band ∼30°N on controlling the moisture supply in East Asia. • The barrier effect of Westerly jet and different moisture sources modulate precessional hydroclimate changes in northern China. [ABSTRACT FROM AUTHOR]

Changes in Asian summer monsoon (ASM) circulation and effective precipitation (precipitation/evaporation, P/E) were reconstructed from stalagmite δ18O and trace element records from Wulu Cave in southern China, covering Chinese Interstadial (CIS) 13 to Heinrich Stadial (HS) 5. The timing of HS 5 in our record (48.5 ± 0.1 ka, 47.2 ± 0.1 ka) agrees well with spatially-separated cave records (48.7 ± 0.1 ka, 47.4 ± 0.2 ka). At the onset of HS 5, Asian hydroclimate changes are coeval with bipolar ice-core records, but lead the Greenland warming by 300 years at the termination or are synchronous with Greenland records via the atmospheric CH4 constraint. During HS 5, the evolution of δ18O-based ASM, featuring four-phased variability, is less clear in element-inferred P/E variations. In contrast, the element records generally exhibit coherent variations among themselves, and are characterized by greater values in CIS 13 (stronger prior calcite precipitation (PCP) under seasonal drought conditions), followed by a rapid decline to a lower-than-average level (weaker PCP under relatively wetting conditions) during HS 5. This implicates an enhanced evaporation in the interstadial, but sufficient moisture availability during HS 5. The ASM weakening in mid-HS 5 is significantly stronger, in degree, than during Chinese Stadial (CS) 14, while the P/E variability in HS 5 is practically equivalent to that in CS 14. It suggests a pronounced sensitivity of ASM and an inertial effective precipitation response to HSs. Probably, the ocean–atmosphere interactions at low latitudes could favor the sustained moisture availability in southern China during HS 5. This at least implicates that the effective rainfall in southern China is less sensitive to climate perturbations during HS 5. [ABSTRACT FROM AUTHOR]

Aim: Evergreen broad-leaved forests (EBLFs) occupy most tropical and subtropical regions of mainland Asia and exhibit high species diversity, productivity and richness. Understanding the historical dynamics of EBLFs is important for biodiversity conservation and regional carbon storage and cycling under global climate change. However, little is known about the historical dynamics of EBLFs in mainland Asia. Dendrobium, an epiphytic orchid genus found in EBLFs, was used to gain new insights of the historical establishment and extension of EBLFs in mainland Asia. Location: Mainland Asia. Methods: We sampled c. 80% of the currently recognized species of Dendrobium found in mainland Asia. A phylogeny was generated using maximum parsimony, maximum likelihood and Bayesian inference methods. A calibrated chronogram was obtained using a Bayesian relaxed-clock model approach. Biogeographical scenarios were investigated using the statistical dispersal- vicariance analysis and dispersal-extinction-cladogenesis methods. Ancestral states were constructed by mesquite and bayestraits, and diversification of Dendrobium was investigated by APE and LASER packages. Results Our results indicate that Asian Dendrobium was present on mainland Asia since the Oligocene, after which this genus diversified in this region and dispersed into higher elevations. The ancestral habit of Dendrobium was epiphytic and terrestrial and lithophytic habits each have multiple, recently independent origins. Main conclusions Our results support the hypothesis that EBLFs have been established in mainland Asia at least since the Oligocene and further suggest that the EBLFs of mainland Asia expanded into higher elevations prior to the late Cenozoic. The diversification of Asian Dendrobium coincided with a warmer climate during the late Oligocene and middle Miocene and the expansion of key groups (including Fagaceae, Lauraceae, Magnoliaceae and Theaceae) of EBLFs during the early Cenozoic. [ABSTRACT FROM AUTHOR]

Congenital hemidysplasia with ichthyosiform nevus and limb defects ( CHILD) syndrome is an X-linked autosomal dominant disorder characterized by unilateral congenital hemidysplasia with ichthyosiform erythroderma and ipsilateral limb defects caused by a mutation in the gene encoding NAD[P]H steroid dehydrogenase-like protein ( NSDHL) at Xq28. The histopathologic hallmark of skin lesions in CHILD syndrome is psoriasiform epidermis with hyperkeratosis and parakeratosis, and its most striking feature affecting the upper dermis is filling of the papillary dermis with foam cells. Here we present the case of a 9-year-old Chinese girl born with the typical clinical features of CHILD syndrome. Histologic and immunohistochemical evaluation of the skin lesions confirmed the diagnosis and led to identification of a heterozygous point mutation in exon 8 of the NSDHL gene. In addition, we provide a literature review of 26 unrelated CHILD syndrome patients from different countries, caused by 20 unique gene mutations occurring throughout the entire NSDHL gene, to promote understanding and provide a more comprehensive description of this unusual disorder. [ABSTRACT FROM AUTHOR]

2-Amino-7,4′-dimethoxyisoflavone ( I), CHNO and 2-amino-7-methoxy-4′-hydroxyisoflavone ( II), CHNO were synthesized and their crystal structures were determined by single-crystal X-ray diffraction. They all crystallize in the monoclinic crystal system, space group P21/c. The cell dimensions of I are a = 15.6673(17) Å, b = 7.3998(8) Å, c = 13.2919(14) Å, β = 111.4460(10)°, D = 1.377 mg/mm, V = 1,434.3(3) A, Z = 4 and those of II are a = 10.990(7) Å, b = 11.879(7) Å, c = 10.422(6) Å, β = 96.904(11)°, D = 1.393 mg/mm, V = 1,350.8(14) A, Z = 4. A combination of F-type and T-type aromatic–aromatic interaction and hydrogen bonding links the molecules of I into a tri-dimensional framework structure. In the crystal structure of II, paired tri-centered hydrogen bond generates a R(21) ring and the R(21) rings link the molecules into a sheet. Graphical Abstract: A combination of F-type and T-type aromatic–aromatic interaction and hydrogen bonding links the molecules of 2-amino-4′,7-dimethoxyisoflavone into a tri-dimensional framework structure. In the crystal structure of 2-amino-7-methoxy-4′-hydroxyisoflavone, paired tri-centered hydrogen bond generates a R(21) ring and the R(21) rings link the molecules into a sheet. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: The population size structure, growth dynamics and mode of competition among adult trees (≥4 cm DBH) of six abundant tree species in a 5 ha study plot of a temperate deciduous forest in the Dongling Mountains in northern China were investigated using diffusion and growth dynamics models. In the year of 2000, two dominant species, Quercus liaotungensis and Betula dahurica accounted for ca. 68.69% of the total basal area and 52.71% of the total density of adult plants. Q. liaotungensis, Populus davidiana and Acer mono exhibited inverse J-shaped DBH distributions whereas Betula dahurica, B. platyphylla and Salix caprea had unimodal DBH distributions. One-sided interspecific competition was detected between some species combinations at the scale of the 5 ha study plot, and the competitive effect was mainly size-dependent rather than from species-specific interactions with large individuals in the canopy layer out competing smaller individuals in the understory. Symmetric competition was found between Q. liaotungensis and A. mono only. However, considering the straight line relationship of G (t, x) –, which suggests that competitive asymmetry is very low or absent, combined with the relatively low mortality of trees with a DBH larger than 4 cm, we speculate that asymmetric interspecific competition was not important in structuring this tree community. Regeneration characteristics of each species are most likely important in regulating species coexistence and stand dynamics in this forest. [Copyright &y& Elsevier]

Besides light curves and spectra, polarization provides a different powerful tool of studying the gamma-ray burst (GRB) prompt phase. Compared with the time-integrated and energy-integrated polarization, time-resolved and energy-resolved polarization can deliver more physical information about the emitting region. Here we investigate time-resolved and energy-resolved polarization of GRB prompt emission using the synchrotron models. We find that the equal arrival time surface effect is very important in shaping the polarization degree (PD) curves when the physical conditions of the emitting region change violently with radius. Polarization properties are neither correlated with the spectral lag nor the peak energy evolution patterns. Polarization properties with a mixed magnetic field are very similar to those for a corresponding ordered magnetic field but the former has a smaller PD. The emission at the MeV peak can be highly polarized for a synchrotron model while it is unpolarized as predicted by a dissipative photosphere model. Future energy-resolved polarization observations can distinguish between these two models. [ABSTRACT FROM AUTHOR]

• Crosslinkers were developed from oligosaccharides for valorization of keratin wastes. • Oligosaccharide crosslinkers were more effective than other non-toxic crosslinkers. • Crosslinking simultaneously improved strength and elongation of keratin films. • Reaction mechanism between sugar crosslinker and keratin was revealed using analogs. • Relationship between tensile properties and crosslinking degree was quantified. Oligosaccharide derivatives were developed to crosslink keratin materials from poultry feathers, swine bristles and ox hairs to valorize these major wastes from meat industry. Global butchery generates more than 8,600,000 tons of keratinous wastes annually. Keratin was considered a promising resource for developing bio-based products as alternatives to petroleum products. Regenerated keratin products, such as films, usually showed insufficient mechanical properties, and required external crosslinking. However, most crosslinkers for proteins are either toxic, expensive, or with low efficiencies under mild conditions. In this research, regenerated keratin films were crosslinked by oxidized sucrose, a safe and potent bio-polyaldehyde. The crosslinker with verified low toxicity improved both tensile strength and elongation of keratin films, surpassing many other safe crosslinkers. Mechanism of the crosslinking reaction was proposed as forming Schiff bases and aminals and verified via 1H NMR and 13C NMR. Relationship between tensile properties and crosslinking degree of keratin films was also quantified. [ABSTRACT FROM AUTHOR]

Aim: The equator‐to‐poles decline in the number of species, namely the latitudinal diversity gradient (LDG), is the most conspicuous pattern in biology, yet the underlying mechanisms of this pattern remain controversial. Species dispersal could have strong effects on large‐scale species distributions but has rarely been considered in understanding the LDG. Here we sought to examine how dispersal ability may influence the latitudinal phylogenetic patterns of woody angiosperm assemblages. Location: China. Taxon: Woody angiosperms. Methods: Based on a highly supported mega‐phylogeny constructed from plastid genomes, we assessed the patterns of phylogenetic relatedness and dissimilarity of 1184 trees with three different seed dispersal modes (i.e. zoochory, anemochory and autochory) in 12 permanent forest dynamic plots covering tropical, subtropical and temperate zones in China. Results: We found that, compared with zoochorous and anemochorous species, the less vagile autochorous trees exhibited a much weaker latitudinal pattern in phylogenetic relatedness and higher phylogenetic dissimilarity among plots. The phylogenetic dissimilarity pattern of autochorous trees was explained more by geographic distance than environmental factors, consistent with a dominant role for dispersal limitation. Main Conclusions: Our study, for the first time, demonstrates that seed dispersal mode strongly influences the latitudinal phylogenetic patterns of woody angiosperm assemblages in China and highlights the importance of interaction between dispersal limitation and environmental filtering in determining the large‐scale distribution of forest biodiversity. [ABSTRACT FROM AUTHOR]

A central compact object (CCO; e.g., a black hole) with an accretion disk has been suggested as the common central engine of various astrophysical phenomena, such as gamma-ray bursts (GRBs), tidal disruption events (TDEs), and active galactic nuclei (AGNs). A jet powered by such a system might precess due to the misalignment of the angular momenta of the CCO and accretion disk. Some quasiperiodic behaviors observed in the light curves of these phenomena can be well interpreted within the framework of a precessing jet model. In this paper, we study the emission polarization of precessing jets in these three kinds of phenomena. The polarization angle also shows a gradual change for the synchrotron emission in both the random and toroidal magnetic field configurations with the precessing jet, while it can only change abruptly by 90° for the nonprecessing top-hat jet. Polarization properties are periodic due to the assumptions made in our model. The polarization observations are crucial to confirm the precession nature of jets in GRBs, TDEs, and AGNs. [ABSTRACT FROM AUTHOR]

A large-scale ordered magnetic field plays a very important role in the formation and acceleration of a gamma-ray burst (GRB) jet. During the GRB prompt phase, some dissipation processes may occur and disturb the magnetic field, making the field become random to some extent. Therefore, a mixed magnetic field consisting of an ordered component and a random component is plausible for the early afterglow phase. Here we investigate the polarization evolution and light curve of an afterglow under such a three-dimensional mixed magnetic field. Three kinds of ordered component (i.e., aligned, toroidal, and radial) are discussed. We find that the three cases are distinguishable through jet polarization evolution. The polarization angle for a 3D mixed magnetic field with an aligned ordered component can evolve gradually but only changes abruptly by 90° in the toroidal and radial cases. Furthermore, during the reverse shock crossing time, the polarization degree (PD) can be non-zero for the toroidal case but roughly zero for the radial case. Since an aligned component in a jet corresponds to a magnetar central engine and a toroidal component corresponds to a black hole, GRB central engines are distinguishable through polarization observations even if the magnetic field is mixed in a jet. In addition, our polarization calculation can be applied to GRB 170817A associated with GW170817. Using the recently observed PD upper limit 12% of GRB 170817A at t = 244 days, the magnetic field strength ratio of the ordered to random components in this afterglow is constrained to be ≲0.9. [ABSTRACT FROM AUTHOR]

Genetic studies have elucidated mechanisms that regulate aging; however, there has been little progress in identifying drugs that retard ageing. Caenorhabditis elegans is among the classical model organisms in ageing research. Methyl 3,4-dihydroxybenzoate (MDHB) can prolong the life-span of C. elegans, but the underlying molecular mechanisms are not yet fully understood. Here, we report that MDHB prolongs the life-span of C. elegans and delays age-associated declines of physiological processes. Besides, MDHB can lengthen the life-span of eat-2 (ad1113) mutations, revealing that MDHB does not work via caloric restriction (CR). Surprisingly, the life-span–extending activity of MDHB is completely abolished in daf-2 (e1370) mutations, which suggests that daf-2 is crucial for a MDHB-induced pro-longevity effect in C. elegans. Moreover, MDHB enhances the nuclear localization of daf-16/FoxO, and then modulates the expressions of genes that positively correlate with defenses against stress and longevity in C. elegans. Therefore, our results indicate that MDHB at least partially acts as a modulator of the daf-2/daf-16 pathway to extend the lifespan of C. elegans, and MDHB might be a promising therapeutic agent for age-related diseases. [ABSTRACT FROM AUTHOR]

Herein – with the optimization goals of a lightweight, large-span structure; modularization; and heavy loading – a tapered-section truss module and standard truss module are integrated and assembled, yielding a new design for an all-carbon-fiber-reinforced polymer (CFRP) truss structure. The design structure fully considers the mechanical characteristics of the truss and the requirements of standardized production efficiency, integrating the "fish keel" structural design method to give it a hollow structure style. By fabricating two 1:1 truss structures (A-Truss and B-Truss) with a length of 20.4 m, the conceptual design, modular design method, and integrated assembly technology of the truss structure were effectively verified; further, experimental research on the strength performance of the mold-clave-forming plate-type joint and the axial compression behavior of large-span full CFRP truss structure is carried out. The failure position of the truss structure is determined, and an enhancement measure for the key connection joint between the truss modules is proposed. Based on specific application scenarios, it is clear that the truss meets the design requirements in terms of bearing capacity and deformation, and can be used as the main bearing structure of large aircraft and aerospace assembly platforms. [ABSTRACT FROM AUTHOR]

Aim: Understanding how spatial distributions of rare and common species are associated with environmental and spatial processes is essential to understanding community assembly. We addressed the following questions: (a) does the relative importance of space and topography vary from rare to common tree species? (b) Are the contributions of topography and space equal? (c) Are the variances explained by topography or space correlated with elevational ranges (ER) at the local scale? (d) Does cell‐size influence those postulated associations? Location: China and the Americas. Major taxa studied: Tree species. Methods: We partitioned the variation in species richness and composition of rare and common tree species by topography and space across a range of extents and grain sizes in eight communities. We calculated contribution ratio (CR) between space and topography to quantify their relative importance. We employed Kendall's rank correlation to determine the relation between CR and commonness. Mixed effect models were used to identify the influence of cell‐size on the results. Results: The majority of CR values were positively related to increasing commonness, especially for composition. The explained variances by space were always higher than that by topography regardless of commonness. At local scale, variances explained by space or topography were not correlated with ER. Main conclusions: Our results indicate that the relative importance of space compared to topography increases from rare to common species across forests. We suggest that future studies of community assembly need to account for both space and topography to adequately describe differences in rare and common species assembly mechanisms at range of spatial extents and grain sizes. [ABSTRACT FROM AUTHOR]

The X-ray afterglows of almost one-half of gamma-ray bursts have been discovered by the Swift satellite to have a shallow decay phase of which the origin remains mysterious. Two main models have been proposed to explain this phase: relativistic wind bubbles (RWBs) and structured ejecta, which could originate from millisecond magnetars and rapidly rotating black holes, respectively. Based on these models, we investigate polarization evolution in the shallow decay phase of X-ray and optical afterglows. We find that in the RWB model, a significant bump of the polarization degree evolution curve appears during the shallow decay phase of both optical and X-ray afterglows, while the polarization position angle abruptly changes its direction by 90°. In the structured ejecta model, however, the polarization degree does not evolve significantly during the shallow decay phase of afterglows whether the magnetic field configuration in the ejecta is random or globally large-scale. Therefore, we conclude that these two models for the shallow decay phase and relevant central engines would be testable with future polarization observations. [ABSTRACT FROM AUTHOR]

The central engine and jet composition of gamma-ray bursts (GRBs) remain mysterious. Here we suggest that observations on the polarization evolution of early optical afterglows may shed light on these questions. We first study the dynamics of a reverse shock and a forward shock that are generated during the interaction of a relativistic jet and its ambient medium. The jet is likely magnetized with a globally large-scale magnetic field from the central engine. The existence of the reverse shock requires that the magnetization degree of the jet should not be high (σ ≤ 1), so that the jet is mainly composed of baryons and leptons. We then calculate the light curves and polarization evolution of early optical afterglows and find that when the polarization position angle changes by 90° during the early afterglow, the polarization degree is zero for a toroidal magnetic field but is very likely to be nonzero for an aligned magnetic field. This result would be expected to provide a probe for the central engine of GRBs because an aligned field configuration could originate from a magnetar central engine and a toroidal field configuration could be produced from a black hole via the Blandford–Znajek mechanism. Finally, for such two kinds of magnetic field configurations, we fit the observed data of the early optical afterglow of GRB 120308A equally well. [ABSTRACT FROM AUTHOR]

Global biodiversity decline and its cascading effects through trophic interactions pose a severe threat to human society. Establishing the impacts of biodiversity decline requires a more thorough understanding of multi‐trophic interactions and, more specifically, the effects that loss of diversity in primary producers has on multi‐trophic community assembly.Within a synthetic conceptual framework for multi‐trophic beta‐diversity, we tested a series of hypotheses on neutral and niche‐based bottom‐up processes in assembling herbivore and carnivore communities in a subtropical forest using linear models, hieratical variance partitioning based on linear mixed‐effects models (LMMs) and simulation.We found that the observed taxonomic, phylogenetic and functional beta‐diversity of both herbivorous caterpillars and carnivorous spiders were significantly and positively related to tree dissimilarity. Linear models and variance partitioning for LMMs jointly suggested that as a result of bottom‐up effects, producer dissimilarities were predominant in structuring consumer dissimilarity, the strength of which highly depended on the trophic dependencies on producers, the diversity facet examined, and data quality. Importantly, linear models for standardized beta‐diversities against producer dissimilarities implied a transition between niche‐based processes such as environmental filtering and competitive exclusion, which supports the role of bottom‐up effect in determining consumer community assembly.These findings enrich our mechanistic understanding of the 'Diversity Begets Diversity' hypothesis and the complexity of higher‐trophic community assembly, which is fundamental for sustainable biodiversity conservation and ecosystem management. [ABSTRACT FROM AUTHOR]

Schima superba is an important dominant species in subtropical evergreen broadleaved forests of China, and plays a vital role in community structure and dynamics. However, the survival rate of its seedlings in the field is low, and water shortage could be a factor that limits its regeneration. In order to better understand the response of its seedlings to drought stress on a functional genomics scale, RNA-seq technology was utilized in this study to perform a large-scale transcriptome sequencing of the S. superba seedlings under drought stress. More than 320 million clean reads were generated and 72218 unique transcripts were obtained through de novo assembly. These unigenes were further annotated by blasting with different public databases and a total of 53300 unique transcripts were annotated. A total of 31586 simple sequence repeat (SSR) loci were presented. Through gene expression profiling analysis between drought treatment and control, 11038 genes were found to be significantly enriched in drought-stressed seedlings. Based on these differentially expressed genes (DEGs), Gene Ontology (GO) terms enrichment and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis indicated that drought stress caused a number of changes in the types of sugars, enzymes, secondary mechanisms, and light responses, and induced some potential physical protection mechanisms. In addition, the expression patterns of 18 transcripts induced by drought, as determined by quantitative real-time PCR, were consistent with their transcript abundance changes, as identified by RNA-seq. This transcriptome study provides a rapid method for understanding the response of S. superba seedlings to drought stress and provides a number of gene sequences available for further functional genomics studies. [ABSTRACT FROM AUTHOR]

• A new modular design scheme for large-scale modular CFRP wheel-spoke-shaped pre-tensioned structures is proposed. • The design scheme of the CFRP wheel-spoke-shaped pre-tensioned structure is verified. • A single-point synchronous graded tensioning method was proposed. • The stiffening ring structure achieves a self-equilibrium at the designed prestress level. The development of large-scale space flight platforms and space vehicles has led to the definition of ultra-lightweight and large-span structural design requirements for backbone structures. Taking the large-scale production, lightweight, modularization, and rapid assembly requirements as the optimization design goals, the modularization technology, connection method, and assembly mode of a carbon fiber reinforced polymer (CFRP) truss structure are studied; leading to the proposal of a new modular design scheme for large-scale modular CFRP wheel-spoke-shaped pre-tensioned structure. Based on the single-point synchronous graded tensioning method, an integrated tension test of the large-scale modular CFRP wheel-spoke-shaped structure is carried out with an integrated tension equipment. The consistency of the strain changed when the upper and lower radial cables was tested, the strain characteristics of the triangular joint frame and the CFRP truss during the push-tensioning process were analyzed, and the overall deformation of the large-scale modular CFRP wheel-spoke-shaped structure was studied. The proposed single-point synchronous graded tensioning method can simply and efficiently perform tensioning consistency in the prestressed cables, and therefore solve the engineering issues of low precision, complex tension application, and assembly difficulties in existing circular multi-point synchronous graded tensioning method. The large-scale modular CFRP wheel-spoke-shaped pre-tensioned structure achieves both structural weight reduction and large-scale structural design goals, while having broad application prospects in various aerospace vehicles and space structures. The proposed modular technology, wheel-spoke structure design scheme, and single-point synchronous graded tensioning method have high a scientific contribution, while providing technical support for the development of new spacecrafts. [ABSTRACT FROM AUTHOR]

Oxidized sucrose, an un-traditional biobased crosslinker, was proved as effective as glutaraldehyde in improving water stability of ultrafine fibrous proteins without causing cytotoxicity. Proteins from agricultural byproducts, such as zein, are abundantly available for production of industrial and medical products, but are restricted by their poor water stability and wet properties. An effective and safe crosslinking method became indispensable for protein-based materials, especially biomaterials. Fibrous basic units with sub-micron scale were critical for biomaterials to resemble native extracellular matrices (ECMs) structurally. In this research, sucrose was oxidized into polar polyaldehydes to crosslink ultrafine fibrous scaffolds from corn protein. The control groups were crosslinked with glutaraldehyde, a known highly effective crosslinker with considerable toxicity. With similar improvement in water stability, the oxidized sucrose crosslinked scaffolds showed much better cytocompatibility than the glutaraldehyde crosslinked ones via in vitro study with preosteoblast cells. [ABSTRACT FROM AUTHOR]

High-resolution stalagmite δ18O records, representing Asian summer monsoon (ASM) intensity, were reconstructed from Wulu and Xiao caves, southwestern China, over Chinese Interstadials (CIS) 25 and 22. A most prominent feature of these stalagmite records is a persistent ASM strengthening throughout the entire event, different from a gradual cooling in corresponding events at Greenland and Antarctica. It implicates that the cooling in the Southern Hemisphere may intensify the ASM circulation through increased cross-equatorial flow, which overwhelms the northern high-latitude impact. Combined with previous published records over the past two interglacial-glacial cycles, diverse trends of CIS events generally match with changes in North Hemisphere summer insolation (NHSI). Accordingly, three modes of CIS ASM variability can be observed, i.e., ASM strengthening when NHSI increases, weakening when NHSI decreases, and a relatively stable ASM during NHSI peak. We argue that NHSI variability or interhemispheric gradient could change the strength of cross-equatorial flow, and in turn, alter the landward transport of monsoonal moisture. The mean isotopic composition of moisture, inherited by stalagmite δ18O signal especially in southern China, is likely a reflection of energy balance between hemispheres. [ABSTRACT FROM AUTHOR]

Objectives: Proper blood lipid levels are essential for survival in older adults, but inconsistent relationships have been reported between blood lipids and all-cause mortality in the elderly.Methods: This retrospective longitudinal study analyzed data from 1,067 Chinese older adults enrolled in the Chinese Longitudinal Healthy Longevity Survey collected in 2008 and followed up until death or December 31, 2018. The outcome was all-cause mortality. Multivariate Cox regression analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with stratification by age (60-80, 80-100, or ≥100 years) for further analysis. The survival probability according to lipid profile quartiles was calculated using Kaplan-Meier curves and the log-rank test.Results: The participants' mean age was 84.84 years, and 57.0% were female. In total, 578 individuals died, and 277 were lost to follow-up. The mean total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were higher among those who died than among those who survived. Participants in the second HDL-C quartile and the highest LDL-C and triglyceride (TG) quartiles had 28% higher, 23% lower, and 49% lower risks of all-cause mortality, respectively. After further adjustment, the associations remained except for HDL-C, and additional associations were observed between all-cause mortality and the third TC and LDL-C quartiles and the second TG quartile (HR, 1.44; 95% CI, 1.01 to 2.06; HR, 0.68; 95% CI, 0.49 to 0.94; HR, 0.79; 95% CI, 0.62 to 0.99, respectively).Conclusions: Older adults should maintain an LDL-C level of 1.91-2.47 mmol/L and a TG level of no less than 1.66 mmol/L. [ABSTRACT FROM AUTHOR]

Phylogenetic trees have been extensively used in community ecology. However, how the phylogeny construction affects ecological inferences is poorly understood. In this study, we constructed three different types of phylogenetic trees (a synthetic‐tree generated using V.PhyloMaker, a barcode‐tree generated using rbcL+matK+trnH‐psbA, and a plastome‐tree generated from plastid genomes) that represented an increasing level of phylogenetic resolution among 580 woody plant species from six forest dynamic plots in subtropical evergreen broadleaved forests of China. We then evaluated the performance of each phylogeny in estimations of community phylogenetic structure, turnover and phylogenetic signal in functional traits. As expected, the plastome‐tree was most resolved and most supported for relationships among species. For local phylogenetic structure, the three trees showed consistent results with Faith's PD and MPD; however, only the synthetic‐tree produced significant clustering patterns using MNTD for some plots. For phylogenetic turnover, contrasting results between the molecular trees and the synthetic‐tree occurred only with nearest neighbor distance. The barcode‐tree agreed more with the plastome‐tree than the synthetic‐tree for both phylogenetic structure and turnover. For functional traits, both the barcode‐tree and plastome‐tree detected phylogenetic signal in maximum height, but only the plastome‐tree detected signal in leaf width. This is the first study that uses plastid genomes in large‐scale community phylogenetics. Our results highlight the improvement of plastome‐trees over barcode‐trees and synthetic‐trees for the analyses studied here. Our results also point to the possibility of type I and II errors in estimation of phylogenetic structure and turnover and detection of phylogenetic signal when using synthetic‐trees. [ABSTRACT FROM AUTHOR]

A simple and straightforward methodology towards the synthesis of 2,4,5-trisubstituted pyrimidines has been developed by one-step reaction of isoflavones with thiourea or guanidine. Ten 2-mercapto-4,5-diphenylpyrimidines and eight 2-amino-4,5-diphenylpyrimidines were reported. All of them were characterized by FT-IR, NMR, and elemental analysis. A variety of substrates can participate in the process with good yields and high purities, making this methodology suitable for library synthesis in drug discovery. J. Heterocyclic Chem., (2011). [ABSTRACT FROM AUTHOR]

A simple and straightforward methodology toward the synthesis of novel 4,5-biphenyl-2-pyrimidinylguanidine compounds has been developed by one-pot reaction of biguaninde or dimethyldiguanide with isoflavones. A series of 20 new compounds was reported. All of them were characterized by FT-IR, NMR, and elemental analysis. A typical compound was determined by X-ray diffraction. A variety of substrates can participate in the process with good yields and high purities, making this methodology suitable for library synthesis in drug discovery. [ABSTRACT FROM AUTHOR]

Background: Fatty liver has become a main problem that causes huge economic losses in many aquaculture modes. It is a common physiological or pathological phenomenon in aquaculture, but the causes and occurring mechanism are remaining enigmatic. Methods: Each three liver samples from the control group of allogynogenetic gibel carp with normal liver and the overfeeding group with fatty liver were collected randomly for the detailed comparison of histological structure, lipid accumulation, transcriptomic profile, latent pathway identification analysis (LPIA), marker gene expression, and hepatocyte mitochondria analyses. Results: Compared to normal liver, larger hepatocytes and more lipid accumulation were observed in fatty liver. Transcriptomic analysis between fatty liver and normal liver showed a totally different transcriptional trajectory. GO terms and KEGG pathways analyses revealed several enriched pathways in fatty liver, such as lipid biosynthesis, degradation accumulation, peroxidation, or metabolism and redox balance activities. LPIA identified an activated ferroptosis pathway in the fatty liver. qPCR analysis confirmed that gpx4, a negative regulator of ferroptosis, was significantly downregulated while the other three positively regulated marker genes, such as acsl4, tfr1 and gcl, were upregulated in fatty liver. Moreover, the hepatocytes of fatty liver had more condensed mitochondria and some of their outer membranes were almost ruptured. Conclusions: We reveal an association between ferroptosis and fish fatty liver for the first time, suggesting that ferroptosis might be activated in liver fatty. Therefore, the current study provides a clue for future studies on fish fatty liver problems. [ABSTRACT FROM AUTHOR]

In this work, a salt-free and low alkali dyeing process was developed through cationic modification of cotton fabric with a series of quaternary ammonium salts (QAS). The dyeing performance indicated that the cationic cotton fabric treated with 3-chloro-2-hydroxypropyldimethyloctane ammonium chloride (CT-8) achieved better K/S value (8.87) and dye fixation (90.47 %) compared to the conventional dyeing process. Notably, the CT-8 treated fabric performed exceptionally under salt-free conditions and with a Na 2 CO 3 concentration of 5 g/L. The rationale behind the adoption of a salt-free and low-alkali dyeing process was attributed to the positive charge of quaternary ammonium groups, which had an augmenting impact on the hydroxyl reaction activity of cotton fabrics. The condensed Fukui function, atomic charge, and HOMO orbital calculations showed that the QAS structure could regulate the hydroxyl reactivity of cationic cotton fabric. Our salt-free and low alkali dyeing process not only achieved the aim of reducing chemical consumption and emissions, but also contributed to better understand the effect of hydroxyl reactivity of cationic cotton on the fixation reaction with reactive dye, and provided a new direction to achieve the require of sustainable development and clean production for a variety of industrial crops and products. [Display omitted] [ABSTRACT FROM AUTHOR]

• An experimental system is developed to conduct vibration experiments on large films in air. • The dynamic equivalent methodology has been demonstrated for a larger rectangular membrane. • Vibration test results show that added masses affect the dynamic equivalence of grid membranes. While the dynamic equivalent methodology of substituting grid membranes for rectangular membranes in air vibration testing has been validated at small scales, scaling up to large rectangular membranes presents challenges such as gravity, uneven stress, and low-frequency identification. This paper uses numerical and experimental methods to explore the dynamic equivalence of a large rectangular membrane and a grid membrane. An experimental system is designed to conduct vibration tests of grid membranes in air, with the vertically arranged, bi-directionally tensioned grid membranes reducing the influence of gravity and flexible tensioning devices, eliminating shear stresses, and facilitating the realization of a uniform stress field. Additionally, the grid membrane is excited using rapid sinusoidal sweep excitation with an exciter, which effectively excites the low-order modes. At the same time, a laser vibrometer is utilized to accurately measure the velocity time history data at the observation points. Combining the observation points' velocity time history data with the exciter's force time history data, signal processing, and modal analysis techniques effectively identify the low-order modes. A series of grid membranes with various added masses are compared with the numerical results of rectangular membranes with respect to frequency and mode shape. The first three modes show a consistent frequency and mode shape between the large rectangular and grid membranes, while the mode correlation decreases with higher modes. Increasing the additional mass at the intersection of the grid membrane enhances frequency consistency without altering mode correlation. [ABSTRACT FROM AUTHOR]

A rigid-flexible tensegrity airship structure is proposed through the systematic research and design of the wheel spoke–shaped stiffening ring, carbon fiber–reinforced polymer slender cable, central longitudinal compression truss, and spherical multi-part integration assemblage. This structure aimed to fully utilize the structural performance advantages of a semi-rigid airship and the self-equilibrating characteristics of a tensegrity structure. The design of the spherical multi-part integration assemblage facilitates the rotation of a wheel spoke–shaped stiffening ring and enhances the installation efficiency of longitudinal cables. The tensegrity system is applied to the rigid-flexible integrated airship structure to make the main compression-bearing shaft bear the compressive stress and the longitudinal cables bear the tensile stress, thereby creating a rigid-flexible tensegrity airship structure with the self-equilibrating system. The feasibility of the structural design, component preparation, and integrated assembly technology of the rigid-flexible tensegrity airship has been effectively verified and evaluated by the integral assembly procedure, which ensures the assembly safety and reliability of the airship structure. The rigid-flexible tensegrity airship structure exhibits a clear load transfer path, high stiffness, bearing capacity, and strong shape retention capacity under low pressure conditions, which provides an ideal structural form for the stratospheric airship. • A new modular large-scale CFRP wheel spoke–shaped stiffening ring is proposed. • A CFRP slender cable with a geometric locking end-fitting is designed and developed. • A new type of spherical multi-part integration assemblage is designed to facilitate the installation of longitudinal cables. • Two types of large-span central longitudinal compression trusses are designed and developed. • The tensegrity system is applied to create a rigid-flexible tensegrity airship structure. [ABSTRACT FROM AUTHOR]

Elucidating symbiotic relationships between arbuscular mycorrhizal fungi (AMF) and plants contributes to a better understanding of their reciprocally dependent coexistence and community assembly. However, the main drivers of plant and AMF community assembly remain unclear. In this study, we examined AMF communities from 166 root samples of 17 woody plant species from 10 quadrats in a Chinese subtropical forest using 454 pyrosequencing of 18S rRNA gene to describe symbiotic AMF–plant association. Our results show the woody plant–AMF networks to be highly interconnected and nested, but in antimodular and antispecialized manners. The nonrandom pattern in the woody plant–AMF network was explained by plant and AMF phylogenies, with a tendency for a stronger phylogenetic signal by plant than AMF phylogeny. This study suggests that the phylogenetic niche conservatism in woody plants and their AMF symbionts could contribute to interdependent AMF and plant community assembly in this subtropical forest ecosystem. [ABSTRACT FROM AUTHOR]

Elucidating interactions of above-ground and below-ground communities in different habitat types is essential for understanding biodiversity maintenance and ecosystem functioning., Using 454 pyrosequencing of ITS2 sequences we examined the relationship between subtropical mountain forest soil fungal communities, abiotic conditions, and plant communities using correlation and partial models., Ridge and valley habitats with differing fungal communities were delineated. Total, saprotrophic and pathogenic fungal richness were significantly correlated with plant species richness and/or soil nutrients and moisture in the ridge habitat, but with habitat convexity or basal area of Castanopsis eyrei in the valley habitat. Ectomycorrhizal ( EM) fungal richness was significantly correlated with basal area of C. eyrei and total EM plants in the ridge and valley habitats, respectively. Total, saprotrophic, pathogenic and EM fungal compositions were significantly correlated with plant species composition and geographic distance in the ridge habitat, but with various combinations of plant species composition, plant species richness, soil C : N ratio and pH or no variables in the valley habitat., Our findings suggest that mechanisms influencing soil fungal diversity and community composition differ between ridge and valley habitats, and relationships between fungal and woody plant assemblages depend on habitat types in the subtropical forest ecosystem. [ABSTRACT FROM AUTHOR]

Based on the "light-weight, heavy-load, and large-span" composite truss design goal for the load-bearing structures of large aircraft, the joint construction pattern, modular integration approach, unique connection method for rear connection-rings, and structural design of composite trusses are studied in detail; a novel carbon-fiber-reinforced polymer (CFRP) truss supporting rear connection-ring is proposed. Based on the force characteristics of different section positions and the advantages of different joint types, three different joint types have been adopted: plate-shell-integrated joint (only single-K and double-K patterns), aluminum alloy joints, and butt joints. This can help fully analyze the advantages of different joint types and achieve the optimal design of composite trusses. Each truss module can be designed separately based on the specific functional and usability requirements, which increases the design freedom of the composite truss, and gives the composite truss an aesthetic three-dimensional structure. Based on the unique construction characteristics of the truss ends, axial compression performance tests were carried out on the designed and fabricated 1:1 CFRP truss prototype, with a span of 18.5 m, using specific axial loading equipment. The research results show that the unique connection method of the rear connection-ring achieved uniform load transfer from the rear connection-ring to the truss; the CFRP truss prototype meets two design requirements (bearing capacity ≥ 55.0 kN, axial compression deformation <1/1500), and is particularly suitable for the rear connection-ring to transmit large loads effectively. The proposed novel CFRP truss supporting rear connection-ring has the advantages of efficient structure assemblage, high design freedom, and flexible construction, which meets the design requirements in terms of truss functionality and realizes the "large-span, heavy-load, and light-weight" structural design goal. • A novel carbon-fiber-reinforced polymer (CFRP) truss supporting rear connection-ring is proposed. • The joint construction pattern, modular integration approach, unique connection method, and structural design were effectively verified. • The axial compression behavior of the CFRP truss supporting rear connection-ring is systematically studied. • Three different joints are adopted to leverage the performance advantages of each joint and optimize the overall performance of the composite truss. [ABSTRACT FROM AUTHOR]

Stratospheric airships require a lightweight envelope to contain lighter-than-air (LTA) buoyancy gas, making the lightweight design and pressure-bearing performance of the envelope structure a key research issue. This paper proposes a structural design scheme for a sliding poly-p-phenylene benzobisoxazole (PBO) fiber-rope-reinforced spherical envelope. The aims were to reduce envelope weight and improve pressure-bearing performance while solving the challenges of envelope structural strength. Two types of spherical envelope structures were constructed from Vectran fabric with PBO rope placed in various positions for reinforcement, and subjected to inflatable burst tests. Strain in the seam tape and envelope gores were measured by digital image correlation. A refined envelope structure model was established to simulate the bursting process with consideration of the cutting pattern effect and the mechanical properties of the weld seams. Comparison of the simulation and test results, combined with observations of the tear textures of damaged envelopes, enabled the determination of failure positions. The envelope material at the failure point was disassembled and the micromorphology and microstructure of the bearing layer were observed by scanning electron microscopy (SEM). The process and characteristics of damage origination, propagation, and collection in the envelope material are explained, and the stress behavior and state of the damage positions are analyzed. Based on the study of the mechanical behavior at the failure position, design suggestions for PBO-rope-reinforced spherical envelopes are provided. A strength criterion to incorporate tensile–shear coupling is proposed, which bridges the gap between the uniaxial tensile strength (UTS) and biaxial tensile mechanical properties of the envelope structure. • A structural design scheme using a sliding PBO-rope-reinforced airship envelope structure was proposed. • A sliding PBO-rope-reinforced spherical airship envelope structural model was established. • The stress behavior and state of the damage position were analyzed. • Design suggestions for PBO-rope-reinforced spherical envelopes are provided. • A novel idea of incorporating tensile–shear coupling into a strength criterion was proposed. [ABSTRACT FROM AUTHOR]

• A modal measurement and identification experiment is proposed for air cushions. • The vibration properties of top and bottom layers are simultaneously identified. • The first 8 modes of an air cushion have been firstly and successfully identified. Air cushions have been widely utilised as roofs and facades for large-span buildings owing to their advantages such as ultra-light weight and aesthetic appearance. The dynamic performance of air cushions, which is a typical fluid-solid interaction problem, is complex, because the top layer, bottom layer, and inner air are highly coupled. However, there is a paucity of effective dynamic experimental studies to test the modal characteristics of entire air cushions. Therefore, in this study, a modal measurement and identification method was developed to simultaneously calculate the dynamic properties of both the top and bottom layers of air cushions. A laser displacement sensor array was employed to record the time-history displacement data at the observation points, and the combined application of the fast Fourier transform (FFT) and stochastic subspace identification (SSI) methods was used for modal identification. A hexagonal air cushion was adopted for testing, and the first eight frequencies and modes were successfully identified. The test results indicated that the first mode shape was significantly different from that of a single-layer foil. The one-wave vibration mode shape appeared after the multi-wave mode shapes, which was a unique phenomenon for air cushions. The frequencies and mode shapes of the top and bottom layers were almost identical. The mode deformation of the two layers can be in the same direction or opposite directions, and the frequencies corresponding to the mode shapes of layers vibrating in the same direction were higher than those of layers vibrating in opposite directions. [ABSTRACT FROM AUTHOR]

This study investigated the neuroprotective effects of methyl 3,4-dihydroxybenzoate (MDHB) against t-butyl hydroperoxide (TBHP) induced oxidative damage in SH-SY5Y (human neuroblastoma cells) and the underlying mechanisms. SH-SY5Y were cultured in DMEM + 10% FBS for 24 h and pretreated with different concentrations of MDHB or N-acetyl-l-cysteine (NAC) for 4 h prior to the addition of 40 μM TBHP for 24 h. Cell viability was analyzed using the methylthiazolyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays. An annexin V-FITC assay was used to detect cell apoptosis rates. The 2′,7′-dichlorofluorescin diacetate (DCFH-DA) assay was used to determine intracellular ROS levels. The activities of antioxidative enzymes (GSH-Px and SOD) were measured using commercially available kits. The oxidative DNA damage marker 8-OHdG was detected using ELISA. Western blotting was used to determine the expression of Bcl-2, Bax, caspase 3, p-Akt and Akt proteins in treated SH-SY5Y cells. Our results showed that MDHB is an effective neuroprotective compound that can mitigate oxidative stress and inhibit apoptosis in SH-SY5Y cells. [ABSTRACT FROM AUTHOR]

To study the effects of different exercise intensity performed at different exercise times on lipid metabolism response during prolonged exercise. Nine young men performed endurance exercise at different exercise intensities (60%VO2max or Fatmax) in the morning (9 am to 10 am) or evening (5 pm to 6 pm); blood samples were collected before exercise and immediately and one and two hours after exercise completion. Expired gas was analyzed from the start of exercise until two hours after exercise completion. There were no significant changes in catecholamine (adrenaline and noradrenaline) and free fatty acid levels between morning and evening trials for each endurance exercise intensity. However, the morning and evening trials both exhibited significantly higher lipid oxidation at Fatmax than that at 60%VO2max. These results suggest that exercise at Fatmax offers greater lipid oxidation than that at 60%VO2max, regardless of exercise timing. [ABSTRACT FROM AUTHOR]

A meta-analysis was conducted to evaluate the efficacy of propranolol in the treatment of infantile hemangiomas ( IHs) in Chinese infants. A statistically significant difference was found between infants treated using propranolol and those treated using corticosteroids (p < 0.001). The total effect pooled from 26 single-arm studies using meta-analysis of propranolol on IHs in Chinese infants was 93% (95% confidence interval 0.88, 0.96). [ABSTRACT FROM AUTHOR]

Objective The specific autoantibodies and antigens that mediate systemic lupus erythematosus (SLE)-related organ injuries remain largely unknown. This study was undertaken to investigate the antibody-mediated immune response that leads to SLE skin lesions. Methods The study included 85 SLE patients with lupus-specific skin lesions and 31 without skin lesions. The reactivity of serum antibody with skin antigens was determined by immunoblotting using human foreskin as the substrate. Skin antigens were identified using mass spectrometry. Serum antibody was isolated by affinity purification and was injected intracutaneously into mouse skin to determine pathogenicity. Serum antibody levels were monitored by enzyme-linked immunosorbent assay. Results We determined that 78% of the patients with skin lesions had serum antibodies reactive with 35-kd and/or 25-kd skin antigens, which was significantly higher than the percentage of patients without skin lesions ( P < 0.0001), suggesting a correlation between immune response and skin lesions. Acidic ribosomal protein P0 (RPLP0) and galectin 3 were 2 target antigens identified from 35-kd and 25-kd proteins, respectively. Purified serum anti-RPLP0 and anti-galectin 3 antibodies induced lupus-like histologic changes after intracutaneous injection. Anti-RPLP0 and anti-galectin 3 antibody levels were significantly higher in SLE patients than in healthy controls and decreased with skin recovery. Anti-galectin 3 antibody levels were not significantly higher in SLE patients than in patients with dermatomyositis or scleroderma, but strongly related to lupus cutaneous vasculitis. Additionally, levels of the 2 antibodies were positively correlated with leukopenia and C3 deficiency, and the anti-RPLP0 antibody level was also positively correlated with arthritis and SLE disease activity. Conclusion Our findings indicate that the immune response mediated by serum anti-RPLP0 and anti-galectin 3 antibodies plays a key role in the pathogenesis of SLE skin lesions. These findings provide new insights into the mechanism of SLE-related organ disorders. [ABSTRACT FROM AUTHOR]

Exploring the relationships between the biodiversity of groups of interacting organisms yields insight into ecosystem stability and function (Hooper et al. ; Wardle ). We demonstrated positive relationships between host plant richness and ectomycorrhizal ( EM) fungal diversity both in a field study in subtropical China (Gutianshan) and in a meta-analysis of temperate and tropical studies (Gao et al. ). However, based on re-evaluation of our data sets, Tedersoo et al. () argue that the observed positive correlation between EM fungal richness and EM plant richness at Gutianshan and also in our metastudies was based mainly from (i) a sampling design with inconsistent species pool and (ii) poor data compilation for the meta-analysis. Accordingly, we checked our data sets and repeated the analysis performed by Tedersoo et al. (). In contrast to Tedersoo et al. (), our re-analysis still confirms a positive effect of plant richness on EM fungal diversity in Gutianshan, temperate and tropical ecosystems, respectively. [ABSTRACT FROM AUTHOR]

Microbial diversity is generally far higher than plant diversity, but the relationship between microbial diversity and plant diversity remains enigmatic. To shed light on this problem, we examined the diversity of a key guild of root-associated microbes, that is, ectomycorrhizal ( EM) fungi along a plant diversity gradient in a Chinese subtropical forest. The results indicated that EM fungal diversity was positively correlated with host plant diversity. Furthermore, this relationship was best predicted by host genus-level diversity, rather than species-level diversity or family-level diversity. The generality of this finding was extended beyond our study system through the analyses of 100 additional studies of EM fungal communities from tropical and temperate forests. Here as well, EM fungal lineage composition was significantly affected by EM plant diversity levels, and some EM fungal lineages were co-associated with some host plant genera. These results suggest a general diversity maintenance mechanism for host-specific microbes based on higher order host plant phylogenetic diversity. [ABSTRACT FROM AUTHOR]