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Atmospheric aerosol in the Tibetan Plateau (TP) and its surroundings has received widely scientific concern in recent decades owing to its significant impacts on regional climatic and cryospheric changes, ecological and environmental securities, and hydrological cycle. However, our understanding on the atmospheric aerosol in this remote region is highly limited by the scarcely available dataset due to the extremely harsh natural conditions. This condition has been improved in recent decades by constructing a few stable field observatories at typical sites on the TP and its surroundings. A continuous project was carried out since 2015 to investigate the properties and sources of atmospheric aerosols as well as their regional differences in the vast TP regions by performing multiple short-term intensive field observations using a suite of high-resolution online instruments. This paper presents a systematic dataset of the high-time-resolution (hourly scales) aerosol physicochemical and optical properties at eight different sites over the TP and its surroundings from the observation project, including the size-resolved chemical compositions of submicron aerosols, standard high-resolution mass spectra and sources of organic aerosols, size distributions of particle number concentrations, particle light scattering and absorption coefficients, particle light absorptions from different carbonaceous substances of black carbon and brown carbon, and number concentrations of cloud condensation nuclei. In brief, atmospheric aerosols in these remote sites were all well-mixed and highly aged due to their dominated regional transport sources. However, high contributions of carbonaceous organic aerosols, neutralized bulk submicron aerosols, and relatively higher light absorption capability were observed in the southern TP region, whereas secondary inorganic species contributed dominantly to the overall acidic submicron aerosols in the northern TP region. In addition to the insights into the regional differences on aerosol sources and properties in the vast TP regions, the datasets are also useful for the simulation of aerosol radiative forcing and the evaluation of interactions among different components of the Earth system in numerical models. [ABSTRACT FROM AUTHOR]

Acid soils occupy approximately 50% of potentially arable lands. Improving crop productivity in acid soils, therefore, will be crucial for ensuring food security and agricultural sustainability. High soil acidity often coexists with phosphorus (P) deficiency and aluminum (Al) toxicity, a combination that severely impedes crop growth and yield across wide areas. As roots explore soil for the nutrients and water required for plant growth and development, they also sense and respond to below-ground stresses. Within the terrestrial context of widespread P deficiency and Al toxicity pressures, plants, particularly roots, have evolved a variety of mechanisms for adapting to these stresses. As legumes, soybean (Glycine max) plants may acquire nitrogen (N) through symbiotic nitrogen fixation (SNF), an adaptation that can be useful for mitigating excessive N fertilizer use, either directly as leguminous crop participants in rotation and intercropping systems, or secondarily as green manure cover crops. In this review, we investigate legumes, especially soybean, for recent advances in our understanding of root-based mechanisms linked with root architecture modification, exudation and symbiosis, together with associated genetic and molecular strategies in adaptation to individual and/or interacting P and Al conditions in acid soils. We propose that breeding legume cultivars with superior nutrient efficiency and/or Al tolerance traits through genetic selection might become a potentially powerful strategy for producing crop varieties capable of maintaining or improving yields in more stressful soil conditions subjected to increasingly challenging environmental conditions. [ABSTRACT FROM AUTHOR]

Aiming at the problem of low automation and accuracy of semantic segmentation of transmission line point cloud data, an automatic segmentation algorithm of point cloud data that can extract objects such as towers, ground wires, and conductors is proposed based on the spatial feature distribution and edge detection filtering algorithm of the transmission line. The power plant is being tested using cloud data from the overhead power line LiDAR obtained from a drone. The results show that the algorithms proposed in this document have high accuracy and memory. The precision of the tower, conductor, and ground wire is 99.74%, 99.22%, and 97.69%, respectively, and the recall is 95.08%, 100%, and 97.97%, respectively. The classification effect is better than the commonly used automatic classification software of transmission line point cloud. Therefore, it has significant application value for realizing the accurate extraction of power lines and towers in transmission line point cloud data. [ABSTRACT FROM AUTHOR]

Atmospheric aerosol in the Tibetan Plateau (TP) and its surroundings has received widely scientific concern in recent decades owing to its significant impacts on regional climatic and cryospheric changes, ecological and environmental securities, and hydrological cycle. However, our understanding on the atmospheric aerosol in this remote region is highly limited by the scarcely available dataset, which has been proved to be an important factor on disturbing the climate and environment in this region. The extremely harsh natural conditions hamper the exploration of the observation. This condition has been improved in recent decade by constructing a few stable field observatories at typical sites on the TP and its surroundings. A comprehensive project was carried out since 2015 to investigate the properties and sources of atmospheric aerosols as well as their regional differences in the vast TP regions by performing multiple short-term intensive field observations using a suite of high-resolution online instruments. This paper presents a systematic dataset of the high-time-resolution hourly scales) aerosol physicochemical and optical properties at seven different sites over the TP and its surroundings from the observation project, including the size42 resolved chemical compositions of submicron aerosols, standard high-resolution mass spectra and sources of organic aerosols, size distributions of particle number concentrations, particle light scattering and absorption coefficients, particle light absorptions from different carbonaceous substances of black carbon and brown carbon, number concentrations of cloud condensation nuclei, and concentrations of gaseous pollutants. In brief, atmospheric aerosols in these remote sites were all well-mixed and highly-aged due to their regional transport sources. However, high contributions of carbonaceous organic aerosols, overall neutralized submicron aerosols, and relatively higher light absorption capability were observed in the southern TP, whereas secondary inorganic species contributed dominantly to the overall acidic submicron aerosols in the northern TP. In addition to the insights into the regional differences of aerosol sources and properties in the vast TP regions, the datasets are also useful for the simulation of aerosol radiative forcing and the evaluation of interactions among different components of the Earth system in numerical models. The datasets are available from the National Cryosphere Desert Data Center, Chinese Academy of Sciences (https://doi.org/10.12072/ncdc.NIEER.db2200.2022; Xu, 2022). [ABSTRACT FROM AUTHOR]

Due to the very importance for both fundamental research and technological applications, smart materials with stimuli-responsive properties have been studied intensively. Theoretical investigation contributes to this endeavor through constructing and analyzing a model system which captures main features of the corresponding complex material, wherefrom useful insight can be provided to the trialand- error experiments. We here report a theoretical study on the smart spherical nanoparticle grafted with light-responsive azobenzene-containing polymers. Utilizing the photoisomerization ability of the azobenzene group, nanoparticles can undergo a light-induced expansion-contraction transition. The wormlike chain based single chain in mean field theory, which has been developed by us recently, is used to investigate this transition in detail. Exploring a large parameter space, our results definitely determine the parameters, including the chain length and effective Kuhn length of grafted chain, nanoparticle radius, grafting density, and position of the azobenzene group along the chain contour, to admit optimum light-responsive behavior of the smart nanoparticle, which provides a guide for experimentalists to design this type of material in a rational manner. [ABSTRACT FROM AUTHOR]

In this paper, we prove the existence of a positive ground state solution to the following coupled system involving nonlinear Schrödinger equations: {-Δu+V1(x)u=f1(x,u)+λ(x)v,-Δv+V2(x)v=f2(x,v)+λ(x)u,x∈R²,x∈R², where λ,V1,V2∈C(R²,(0,+∞)) and f1,f2:R²×R→R have critical exponential growth in the sense of Trudinger-Moser inequality. The potentials V1(x) and V2(x) satisfy a condition involving the coupling term λ(x), namely 0<λ(x)≤λ0√V1(x)V2(x). We use non-Nehari manifold, Lions's concentration compactness and strong maximum principle to get a positive ground state solution. Moreover, by using a bootstrap regularity lifting argument and Lq-estimates we get regularity and asymptotic behavior. Our results improve and extend the previous results. [ABSTRACT FROM AUTHOR]

Responsive behavior of polymer brush to the external compression is one of the most important characters for its application. For the flexible polymer brush, in the case of low grafting density, which is widely studied by the Gaussian chain model based theory, the compression leads to a uniform deformation of the chain. However, in the case of high grafting density, the brush becomes anisotropic and the nematic phase will be formed. The normal compression tends to destroy the nematic order, which leads to a complex responsive behaviors. Under weak compression, chains in the nematic brush are buckled, and the bending energy and Onsager interaction give rise to the elasticity. Under deep compression, the responsive behaviors of the nematic polymer brush depend on the chain rigidity. For the compressed rigid polymer brush, the chains incline to re-orientate randomly to maximize the orientational entropy and its nematic order is destroyed. For the compressed flexible polymer brush, the chains incline to fold back to keep the nematic order. A buckling-folding transition takes place during the compressing process. For the compressed semiflexible brush, the chains are collectively tilted to a certain direction, which leads to the breaking of the rotational symmetry in the lateral plane. These responsive behaviors of nematic brush relate to the properties of highly frustrated worm-like chain, which is hard to be studied by the traditional self-consistent field theory due to the difficulty to solve the modified diffusion equation. To overcome this difficulty, a single chain in mean-field theory incorporating Monte Carlo simulation and mean-field theory for the worm-like chain model is developed in present work. This method shows high performance for entire region of chain rigidity in the confined condition. [ABSTRACT FROM AUTHOR]

A precise representation of the structure factor of a wormlike chain for the arbitrary chain flexibility in an orientational external field is obtained by virtue of the numerical solution to the modified diffusion equation satisfied by the Green's function. The model is built from a standard wormlike chain formalism in a continuous version which crossovers from the rigid-rod limit to the flexible chain limit and the Maier-Saupe interaction which describes the orientational effects from the nematic field. The behaviors of the structure factor in the distinct wavevector k regimes are numerically investigated as functions of chain flexibility and tilt angle between the directors of the nematic field and k. The radius of gyration extracted from the structure factor in small-k regime is also carefully analysed in both the directions along and perpendicular to the nematic axis. Our calculations exactly recover the prediction of the structure factor undergoing an orientational field in the rigid rod limit. [ABSTRACT FROM AUTHOR]

Although the volume transition of the polyelectrolyte gel has been studied for decades, less study on the finite size effects of the mobile ions has been conducted. In the present paper, Tanaka's classical theory of polyelectrolyte gel is extended to the cases of mobile ions of finite volume. In the salt free limit, the theoretical results show that the discontinuous volume transition of the polyelectrolyte gel will become a continuous one for counterionic size larger than a critical value. When a significant amount of salt is added, the critical value for the volume transition increases as a result of electrostatic screening. An increase in salt concentration can also make the polyelectrolyte gel in poor solvent collapse. Poorer solvent is needed to trigger the salt-induced collapse in polyelectrolyte gel with larger mobile ions than that with smaller ones. The effects of ionic size on the critical points and phase diagram of the volume transition are also discussed. The theoretical results suggest that the swelling behavior of polyelectrolyte gel might be tuned with salt of different volumes. [ABSTRACT FROM AUTHOR]

Coal mine gangue hills have a significant impact on the ecological environment. To address this challenge, gravity heat pipes have been recognized as an effective means of controlling deep-seated temperature in coal mine gangue hills. Among various factors affecting heat transfer efficiency, the magnitude of external airflow velocity in the heat dissipation section of the heat pipe is critical. In this study, we develop a novel chimney effect model for gravity heat pipes in coal mine gangue hills. We employ the non-isothermal flow multiphysics transient solution method to analyze the single-factor effects of entrance radius, height of outlet section, and radius of outlet section on the average velocity at the chimney outlet. Furthermore, we utilize a comprehensive factorial response surface research method to fit the functional relationship between the average velocity at the chimney outlet and various chimney parameters. Notably, our study introduces the height and radius of the outlet section as constraint conditions based on field conditions. As a result, we determine the optimal chimney parameters for achieving the chimney effect in gravity heat pipes within coal gangue hills. Specifically, we set the chimney inlet radius at 1.05 m, the chimney outlet height at 0.03 m, and the chimney outlet radius at 0.145 m. Comparative analysis reveals that introducing the chimney improves the heat dissipation efficiency of the gravity heat pipe by 2.6%. Overall, our study offers innovative approaches to addressing the challenges associated with coal gangue hills and provides valuable insights into the optimization of gravity heat pipes for efficient heat dissipation. [ABSTRACT FROM AUTHOR]

A considerably improved method for the Cu-catalyzed coupling of sulfuryl chloride with P(O)-H was described. Using commercially available l-proline as the ligand decreased the precatalyst loading, broadened the substrate scope and greatly promoted the efficiency of the coupling reaction. Moreover, gram-scale preparation, easy-to handle and recyclable catalyst featured this transformation. [ABSTRACT FROM AUTHOR]

Pyrolysis is considered the most promising way to convert biomass to fuels. Upgrading biomass pyrolysis oil is essential to produce high quality hydrocarbon fuels. Upgrading technologies have been developed for decades, and this review focuses on the hydrodeoxygenation (HDO). In order to declare the need for upgrading, properties of pyrolysis oil are firstly analyzed, and potential analysis methods including some novel methods are proposed. The high oxygen content of bio-oil leads to its undesirable properties, such as chemical instability and a strong tendency to re-polymerize. Acidity, low heating value, high viscosity and water content are not conductive to making bio-oils useful as fuels. Therefore, fast pyrolysis oils should be refined before producing deoxygenated products. After the analysis of pyrolysis oil, the HDO process is reviewed in detail. The HDO of model compounds including phenolics monomers, dimers, furans, carboxylic acids and carbohydrates is summarized to obtain sufficient information in understanding HDO reaction networks and mechanisms. Meanwhile, investigations of model compounds also make sense for screening and designing HDO catalysts. Then, we review the HDO of actual pyrolysis oil with different methods including two-stage treatment, co-feeding solvents and in-situ hydrogenation. The relative merits of each method are also expounded. Finally, HDO catalysts are reviewed in order of time. After the summarization of petroleum derived sulfured catalysts and noble metal catalysts, transitional metal carbide, nitride and phosphide materials are summarized as the new trend for their low cost and high stability. After major progress is reviewed, main problems are summarized and possible solutions are raised. [ABSTRACT FROM AUTHOR]

The worm-like chain is one of the best theoretical models of the semiflexible polymer. The structure factor, which can be obtained by scattering experiment, characterizes the density correlation in different length scales. In the present review, the numerical method to compute the static structure factor of the worm-like chain model and its general properties are demonstrated. Especially, the chain length and persistence length involved multi-scale nature of the worm-like chain model are well discussed. Using the numerical structure factor, Gaussian fluctuation theory of the worm-like chain model can be developed, which is a powerful tool to analyze the structure stability and to predict the spinodal line of the system. The microphase separation of the worm-like diblock copolymer is considered as an example to demonstrate the usage of Gaussian fluctuation theory. [ABSTRACT FROM AUTHOR]

The present study aimed to screen potential genes associated with metastatic prostate cancer (PCa), in order to improve the understanding of the mechanisms underlying PCa metastasis. The GSE3325 microarray dataset, which was downloaded from the Gene Expression Omnibus database, consists of seven clinically localized PCa samples, six hormone-refractory metastatic PCa samples and six benign prostate tissue samples. The Linear Models for Microarray Data package was used to identify differentially-expressed genes (DEGs) and a hierarchical cluster analysis for DEGs was performed with the pheatmap package. Furthermore, potential functions for the DEGs were predicted by a functional enrichment analysis. Subsequently, microRNAs (miRNAs) potentially involved in the regulation of PCa metastasis were identified by WebGestalt software, and the miRNA-DEG regulatory network was visualized using Cytoscape. In addition, a pathway enrichment analysis for DEGs in the regulatory network was performed. A total of 306 and 2,073 genes were differentially expressed in the clinically localized PCa and the metastatic PCa groups, respectively, as compared with the benign prostate group, of which 174 were differentially expressed in both groups. A number of the DEGs, including CAMK2D and SH3BP4, were significantly enriched in the cell cycle, and others, such as MAF, were associated with the regulation of cell proliferation. Furthermore, some DEGs (CAMK2D and PCDH17) were observed to be regulated by miR-30, whereas others (ADCY2, MAF, SH3BP4 and PCDH17) were modulated by miR-182. Additionally, ADCY2 and CAMK2D were distinctly enriched in the calcium signaling pathway. The present study identified novel DEGs, including ADCY2, CAMK2D, MAF, SH3BP4 and PCDH17, that may be involved in the metastasis of PCa. [ABSTRACT FROM AUTHOR]

Lanthanide-based (Ln3+-based) nanoparticles have great potential for high-field magnetic resonance imaging (MRI) applications. Here, we report NaHoF4 and NaDyF4 nanoparticles with modulated sizes (9-40 nim) and shapes (spherical-like, hexagonal prism, rod-like), suitable for high-field MRI as shown through in vivo studies. We used X-ray diffraction, transmission electron microscope, dynamic light scattering, and MRI techniques to investigate the structure, morphology, hydrodynamic size, and relaxivity of the prepared NaHoF4 and NaDyF4 nanoparticles, showing mono disperse nanoparticles of high crystallinity. In particular, we studied effects of the particle size, shape, surface coating and ζ-potential on transverse (spin-spin relativity, r2) and longitudinal (spin-lattice relaxivity, r1) relaxivity at 9.4 T. We found that the NaHoF4 and NaDyF4 nanoparticles have r2 relaxivities of (274.0 ± 6.9) × 104 and (4767.3 ± 160.9) × 104 mMNP-1 s-1 per nanoparticle and high r2/r1 ratio of 781 and 410 at a high magnetic field of 9.4 T, respectively, making them attractive as MRI T2 contrast agents. The growth of the hexagonal structure of the NaHoF4 and NaDyF4 nanoparticles was mainly dominated by the growth competition along the [001] and [100] directions that could be modulated by the amount of oleic acid (OA), 1-octadecene (ODE), NaOH, and NH4F. Moreover, both the larger particle size and thin coating polymer layer of nanoparticles increased the transverse relaxivity. The effects of the parameters, such as rotation correlation time, diffusion, and electronic relation times on the dipolar and Curie components of the inner- and outer-sphere contribution, and thus directly on the relaxivity, are discussed. We found that these parameters can be modulated by the particle size and surface coating. Following the outer-sphere relaxation theory, we used computer simulations of r1 and r2 relaxivity as a function of the particle core size, hydrodynamic size, diffusion time, and electronic relation time, which all show an impact on r1 and r2, albeit to very different extends, which has enhanced our understanding of the relaxivity mechanisms. According to the computer simulations, r1 can be controlled by the core size, hydrodynamic size at low magnetic fields of ~0.02 T corresponding to proton Larmor frequency of about 1 MHz. The r1 does not change significantly at the higher frequency and actually drops precipitously. However, on the basis of theoretical simulations, we expect r2 can be increased in a wide range of Larmor frequencies (0.1-1000 MHz) by increasing the core size, reducing thickness of the coating layer, or increasing the magnetic field. The particle sizes, hydrodynamic sizes, and diffusion times and magnetic fields have larger contribution to the relaxivity than that of other parameters. Five animals were imaged and in vivo MRI showed that the rod-like NaDyF4 (25 nm × 35 nm) nanoparticles, without any targeting ligands, provided visible contrast between brain and breast tumors and normal tissues up to 24 h after injection. Contrast was observed in all animals after injection of nanoparticle solution, which may be attributed to enhanced permeation and retention effects of the rod-shape nanoparticles in tumor. The experimental and simulation results suggest that the NaHoF4 and NaDyF4 nanoparticles are indeed good candidates for high-field (>3 T) T2 imaging contrast agents. [ABSTRACT FROM AUTHOR]

Background: Long-chain non-coding RNA (lncRNA) LINC00609 is a potential tumor suppressor, but the mechanism of action in non-small cell lung cancer (NSCLC) is yet to be understood. Objectives: The effects of LINC00609 on A549 cell proliferation, apoptosis, and cell cycle arrest were investigated. Methods: The LINC00609 levels in NSCLC and normal tissues were analyzed by bioinformatics. Expressions of LINC00609, miR-128-3p, and Rho family GTPase 3 (RND3) in NSCLC cells (A549) were determined by qRT-PCR. Bioinformatics analysis predicted target genes and dual-luciferase reporter assays to ensure that LINC00609 targeted miR-128-3p and miR-128-3p targeted RND3. The proliferation of cells was determined using EDU and CCK-8. Flow cytometry was used to evaluate cell apoptosis rate and cell cycle. The western blotting assay identified proteins related to proliferation and apoptosis. Results: In NSCLC tissues, LINC00609 was expressed in low levels, while its high expression was associated with a higher survival rate. LINC00609 affected cell proliferation, apoptosis, cell cycle arrest, and expression of related proteins. Dual-luciferase reporter assay showed that LINC00609 binds specifically to miR-128-3p, and miR-128-3p binds to RND3. MiR-128-3p overexpression could neutralize the effects of LINC00609. A siRNA targeting RND3 could reverse the effect of the miR-128-3p inhibitor. Silencing RND3 resulted in a decrease in apoptosis rate and the number of cells in the S-phase and an increase in the number of cells in the G1-phase. Furthermore, phosphorylation levels of the AKT protein and mTOR protein, and Bcl2 expression, increased; however, the expression of RND3, Bax, and caspase3 decreased. Conclusions: LINC00609 regulated miR-128-3p/RND3 axis to modulate A549 cell proliferation, apoptosis, and cell cycle arrest. In the case of NSCLC, LINC00609 could be a potential target for therapy. [ABSTRACT FROM AUTHOR]

Double-stranded DNA can exist in multiple structures, including three recently identified overstretched structures (peeled ssDNA, DNA bubble, and S-DNA) for torsion-unconstrained DNA under large tension. Here, we report systematic studies of interconversion between these overstretched DNA structures induced by changing NaCl concentration at constant force. At forces above 70 pN where DNA exists in one of the overstretched states, direct interconversions between S-DNA and DNA bubble for the end-closed DNA construct, as well as interconversions between S-DNA and peeled ssDNA for the end-opened DNA construct, were observed to involve stepwise extension changes. Interestingly, compared to other conversions, the conversion from peeled ssDNA to S-DNA has ultraslow kinetics, which can be explained by formation of secondary hairpin structures on a relaxed strand of peeled ssDNA. Our findings provide important insights into the structures of torsion-unconstrained DNA under large force. [ABSTRACT FROM AUTHOR]

Lignin is an important renewable source of phenolic products. In this study, alkali lignin was depolymerized to produce phenolic compounds. The effects of catalyst, solvent, reaction time, and reaction temperature on the yields of liquid products and volatile fractions were investigated in detail. Compared with the solvents water and octane, alcohols can significantly promote depolymerization of lignin due to the excellent solubility of the degradation products and intermediates. Under the conditions of 300 °C for 2 h in the solvent ethanol, the highest yields of liquid products (75.8 wt%) and volatile fraction (38.1 wt%) were obtained over a ZnCl2 catalyst. Gas chromatograph-mass spectroscopy analysis demonstrated that the volatile fraction was composed of guaiacols (15.09 wt%), phenols (15.79 wt%), and syringols (2.28 wt%). Furthermore, the mechanism for lignin depolymerization is discussed. [ABSTRACT FROM AUTHOR]

For a class of linear time-invariant neutral systems with neutral and discrete constant delays, several existing asymptotic stability criteria in the form of linear matrix inequalities (LMIs) are simplified by using matrix analysis techniques. Compared with the original stability criteria, the simplified ones include fewer LMI variables, which can obviously reduce computational complexity. Simultaneously, it is theoretically shown that the simplified stability criteria and original ones are equivalent; that is, they have the same conservativeness. Finally, a numerical example is employed to verify the theoretic results investigated in this paper. [ABSTRACT FROM AUTHOR]

The variation characteristics of Ultraviolet-B (UVB; 280-315 nm) radiation over Beijing were explored using measured data that were collected in Beijing from November 2010 to October 2011. Seasonal variations in UVB radiation and influence of ozone and clearness index on the ratio of UVB to broadband solar radiation ( G) were investigated. The annual value of UVB radiation in Beijing is 6.37 MJ m−2, and monthly average value ranges from 4.96 to 28.37 kJ m−2 d−1. The maximum daily total UVB radiation ranges from 6.55 kJ m−2 d−1 in November to 54.22 kJ m−2 d−1 in July. The monthly minimum of daily total UVB radiation varies from 0.5 kJ m−2 d−1 in February to 11.52 kJ m−2 d−1 in July. The monthly average of the ratio of UVB radiation to G ranges from 0.007 to 0.017%, with an annual average value of 0.012%. The variation in slant ozone column causes annual cycle of the ratio UVB radiation to G, with maximum value in summer. In addition, clouds have a greater effect on G than UVB radiation. Thus, the ratio increases by more than 17% when the atmospheric conditions change from clear to cloudy. [ABSTRACT FROM AUTHOR]

Double-stranded DNA (d5DNA) unconstrained by torsion undergoes an overstretching transition at about 65 pN, elongating the DNA to about 1.7-fold. Three possible structural transitions have been debated for the nature of DNA overstretching: (I) "peeling" apart of dsDNA to produce a peeled 5sDNA strand under tension while the other strand coils, (II) "inside-strand separation" of dsDNA to two parallel 55DNA strands that share tension (melting bubbles), and (iii) "B-to-S" transition to a novel dsDNA, termed S-DNA. Here we overstretched an end-opened DNA (with one open end to allow peeling) and an end-closed (i.e., both ends of the linear DNA are covalently closed to prohibit peeling) and torsion-unconstrained DNA. We re- port that all three structural transitions exist depending on experimental conditions. For the end-opened DNA, the peeling transition and the B-to-S transition were observed; for the end-closed DNA, the inside-strand separation and the B-to-S transition were observed. The peeling transition and the inside-strand separation are hysteretic and have an entropy change of approximately 17 cal/(K~mol), whereas the B-to-S transition is nonhysteretic and has an entropy change of approximately -2 cal/(K.mol). The force-extension curves of peeled 55DNA, melting bubbles, and S-DNA were characterized by experiments. Our results provide experimental evidence for the for- mation of DNA melting bubbles driven by high tension and prove the existence of nonmelted S-DNA. Our findings afford a full under- standing of three possible force-driven structural transitions of tor- sion-unconstrained DNA and the resulting three overstretched DNA structures. [ABSTRACT FROM AUTHOR]

Double-stranded DNA is a dynamic molecule whose structure can change depending on conditions. While there is consensus in the literature about many structures DNA can have, the state of highly-stretched DNA is still not clear. Several groups have shown that DNA in the torsion-unconstrained B-form undergoes an "overstretching" transition at a stretching force of around 65 pN, which leads to approximately 1.7-fold elongation of the DNA contour length. Recent experiments have revealed that two distinct structural transitions are involved in the overstretching process: (i) a hysteretic "peeling" off one strand from its complementary strand, and (ii) a nonhysteretic transition that leads to an undetermined DNA structure. We report the first simultaneous determination of the entropy (ΔS) and enthalpy changes (ΔH) pertaining to these respective transitions. For the hysteretic peeling transition, we determined ΔS ∼ 20 cal/(K.mol) and ΔH ∼ 7 kcal/mol. In the case of the nonhysteretic transition, ΔS ∼ -3 cal/(K.mol) and ΔH ∼ 1 kcal/mol. Furthermore, the response of the transition force to salt concentration implies that the two DNA strands are spatially separated after the hysteretic peeling transition. In contrast, the corresponding response after the nonhysteretic transition indicated that the strands remained in close proximity. The selection between the two transitions depends on DNA base-pair stability, and it can be illustrated by a multidimensional phase diagram. Our results provide important insights into the thermodynamics of DNA overstretching and conformational structures of overstretched DNA that may play an important role in vivo. [ABSTRACT FROM AUTHOR]

P-Arylation in water has been developed via cross-coupling of aryl halides with diphenylphosphine oxide (Ph2P(O)H) and (RP)-(−)-menthyl benzylphosphinate catalyzed by NiCl2·6H2O/Zn under relatively mild conditions. [ABSTRACT FROM AUTHOR]

Abstract: Supported nickel catalysts for aqueous-phase catalytic hydrogenation/dehydration of furfural were prepared using impregnation method with different supporting materials. Effects of supporting materials, nickel loading and reaction temperature on conversion rate of furfural as well as selectivity for desired product C5 were systematically studied. Experiments showed that catalytic activity of Ni/SiO2–Al2O3 was obviously higher than that of Ni/γ-Al2O3. The conversion of furfural over 14wt.%Ni/SiO2–Al2O3 catalyst was 62.99% under the temperature of 140°C and the cold pressure of H2 3.0MPa, while that was 19.19% over 14wt.%Ni/γ-Al2O3 under the same conditions. Conversion rate of furfural increased with temperature, but selectivity for desired product decreased with temperature. Tentative reaction mechanisms of hydrogenation/dehydration were proposed. In order to investigate catalyst recyclability, a batch of Ni/SiO2–Al2O3 was reused three times and analyzed by Thermogravimetry (TG). It was found that considerable amount of coke formed on Ni/SiO2–Al2O3 surface and deteriorated its activity dramatically after second use. [Copyright &y& Elsevier]

Objective: Postconditioning is a novel approach to myocardial protection during ischemia reperfusion. Our study observed the effect of postconditioning on coronary blood flow velocity and endothelial function in patients who underwent emergency percutaneous coronary intervention (PCI). Methods: Ninety-four patients with their first acute myocardial infarction who underwent revascularization within 12 hours of onset by primary PCI were recruited in the study. All the patients were randomized to two groups, IR group (PCI without postconditioning) and Postcond group (PCI with postconditioning). Corrected TIMI frame count (CTFC) was used to evaluate velocity of coronary blood after PCI. Creatine phosphokinase (CK), CK-MB, and malondialdehyde (MDA) were measured before and after PCI. Arterial endothelial function was studied noninvasively by examination of brachial artery responses to endothelium-dependent and endothelium-independent stimuli by echo Doppler technique. Wall motion score index (WMSI) was assessed by two-dimensional echocardiography before and 8 weeks after angioplasty. Results: There were no significant differences between the two groups with regard to age, sex, presence of angiographically visible collaterals, and elapsed time from the onset of symptoms until perfusion. Patients with postconditioning had much faster CTFC than patients without postconditioning (25.38 ± 5.35 vs 29.23 ± 5.54). After 8 weeks, the WMSI improved significantly in both groups, but the ΔWMSI in Postcond group was significantly larger than that of IR group (1.20 ± 0.30 vs 1.04 ± 0.36, P < 0.05). There was a significant negative correlation between ΔWMSI and CTFC in IR group and Postcond group (r =−0.9032, P < 0.01; r =−0.7884, P < 0.01). The peaks of CK and CK-MB of Postcond group were much lower than that of IR group (1236.57 ± 813.21 U/L vs 1697.36 ± 965.74 U/L; 116.92 ± 75.83 U/L vs 172.41 ± 92.64 U/L), and MDA-reactive products were significantly lower than that in the IR group at any same time after PCI. All patients with acute myocardial infarction had a depressed endothelium-dependent vasodilation function, while the endothelium-dependent vasodilation function was improved in Postcond group. Conclusion: Postconditioning is a simple, operative procedure for salvaging the coronary endothelial function and cardiomyocyte. It could be used widely in clinic and to better the prognosis of acute myocardial infarction. [ABSTRACT FROM AUTHOR]

Visible-light-induced C(sp²)--H phosphorylation of 2H-thiozoles/quinoxalines with H-phosphine oxides was achieved using an inorganic-ligand supported Mo oxide ([N(C4H9)4]2[Mo6O19]) as a hydrogen atom transfer (HAT) photocatalyst. The developed photo-driven C(sp²)--P bond formation protocol could furnish a wide range of products with excellent functional group tolerance in a water-based solvent at room temperature, without the addition of metals, bases, additives or external oxidants. A gram-scale reaction can occur in a low catalyst loading system. Moreover, the formulated photocatalyst showed excellent stability and reusability, and also exhibited satisfactory photo-reactivity under sunlight irradiation. The mechanistic investigations supported that the C(sp²)--P bond formation went through radical coupling or radical nucleophilic addition pathways. [ABSTRACT FROM AUTHOR]

Superior inbred lines are central to maize breeding as sources of natural variation. Although many elite lines have been sequenced, less sequencing attention has been paid to newly developed lines. We constructed a genome assembly of the elite inbred line KA105, which has recently been developed by an artificial breeding population named Shaan A and has shown desirable characteristics for breeding. Its pedigree showed genetic divergence from B73 and other lines in its pedigree. Comparison with the B73 reference genome revealed extensive structural variation, 58 presence/absence variation (PAV) genes, and 1023 expanded gene families, some of which may be associated with disease resistance. A network-based integrative analysis of stress-induced transcriptomes identified 13 KA105-specific PAV genes, of which eight were induced by at least one kind of stress, participating in gene modules responding to stress such as drought and southern leaf blight disease. More than 200,000 gene pairs were differentially correlated between KA105 and B73 during kernel development. The KA105 reference genome and transcriptome atlas are a resource for further germplasm improvement and surveys of maize genomic variation and gene function. [ABSTRACT FROM AUTHOR]

Background: Drought is a critical abiotic stress that influences maize yield and reduces grain yield when it occurs at the flowering or filling stage. To dissect the genetic architecture of grain yield under drought stress (DS), a genome-wide association analysis was conducted in a maize population composed of diverse inbred lines from five locations under well-watered and DS conditions at flowering in 2019 and 2020. Results: Using a fixed and random model circulating probability unification model, a total of 147 loci associated with grain yield or the drought resistance index (DRI) were identified, of which 54 loci were associated with a DRI with an average phenotypic variation explanation of 4.03%. Further, 10 of these loci explained more than 10% of the phenotypic variation. By integrating two public transcriptome datasets, 22 differentially expressed genes were considered as candidate genes, including the cloned gene ZmNAC49, which responds to drought by regulating stomatal density. Enrichment and protein interaction network showed that signaling pathways responded to drought resistance, including jasmonic acid and salicylic acid, mitogen-activated protein kinase, and abscisic acid-activated. Additionally, several transcription factors involved in DS were identified, including basic leucine zipper (GRMZM2G370026), NAC (GRMZM2G347043), and ethylene-responsive element binding protein (GRMZM2G169654). Conclusions: In this study, we nominated several genes as candidate genes for drought resistance by intergrating association maping and transcription analysis. These results provide valuable information for understanding the genetic basis of drought tolerance at the mature stage and for designing drought-tolerant maize breeding. [ABSTRACT FROM AUTHOR]

The preparation of green and economical bio-aviation fuel is a priority for the sustainable development industry. In this study, Jatropha oil was used as a raw material to catalyze the conversion of raw material to aviation kerosene fraction by photothermal coupling under the conditions of light and low temperature. The correlations among conversion rate, target alkane selectivity, composition distribution, and catalyst microstructure were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), nitrogen (N2) adsorption and desorption, X-ray fluorescence (XRF), ammoniatemperature programmed desorption (NH3-TPD), ultraviolet-visible spectrophotometry (UV-Vis), and other characterization. The correlation between conversion and target alkane selectivity and composition distribution and catalyst microstructure was investigated, and different modification methods and different molecular sieve materials were selected. The results showed that the molecular sieves modified with the solid dispersion method could retain the structural stability of titanium dioxide (TiO2) and molecular sieves to a great extent while slightly enhancing the pore capacity and pore size of the catalyst to make it easier to adsorb reactants; the introduction of active metal platinum (Pt) could reduce the forbidden bandwidth of the catalyst, increase the weak acid amount of the catalyst, improve the adsorption capacity of hydrogen (H2), and thus improve the catalytic ability, resulting in a suitable catalyst for this study: P-21. The photothermal catalytic reaction of Jatropha oil using P-21 catalyst obtained 97.21% conversion and 74.99% selectivity of the target alkanes under the optimal process parameters. The results of this study provide effective catalyst parameters for research in the field of clean energy. [ABSTRACT FROM AUTHOR]

PbO2-MnO2 electrodes were prepared by electrochemical codeposition methods. The electrodes were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The content of manganese in the electrodes increased with the increase in manganese ion concentration in the solution, which can reach 48.4%. The codeposition of manganese decreased the grain sizes and formed the porous structure. Cyclic voltammetry and galvanostatic charge{discharge measurements were used to evaluate the inuence of manganese content in the electrodes on the specific capacitive performance of PbO2-MnO2 electrodes. The specific capacitance of PbO2-MnO2 (48.4%) electrodes could reach 374.5 F g-1. The excellent specific capacitance can be ascribed to the porous structure and the synergy of excellent conductivity of lead dioxide and the good specific capacitance of manganese dioxide. [ABSTRACT FROM AUTHOR]

• Piceatannol lightened oxidative injury and collagen synthesis in lung tissues during pulmonary fibrosis. • Piceatannol inhibited the activation and collagen synthesis of TGF-β-induced lung fibroblasts. • JAK2 activation abolished the effects of piceatannol in TGF-β-induced lung fibroblasts. Pulmonary fibrosis (PF) is characterized by oxidative injury and excessive collagen synthesis in lung fibroblasts, causing impaired pulmonary function and chronic lung injury. Piceatannol, a dietary polyphenol, possesses vital pharmacological effects in metabolic disorders, cancers, cardiovascular disease and infectious disease; however, its role in PF is still not completely elucidated. Mice (8 to 10 weeks old) were administered bleomycin (BLM) intratracheally (2 U/kg) to establish an in vivo PF model. Murine primary lung fibroblasts were isolated and stimulated with TGF-β (10 ng/mL) for 48 h to induce its activation. Meanwhile, mice or primary lung fibroblasts were treated with different doses of piceatannol to observe its protective roles. Pulmonary function and arterial blood gas were detected to assess pulmonary physiological status. Collagen deposition and the mRNA levels of profibrotic genes were determined by H&E staining and RT-PCR. Meanwhile, the protein and mRNA markers, as well as end-product of oxidative stress were detected in vivo and in vitro. The results showed that pulmonary function was significantly impaired in BLM-induced mice, accompanied by elevated oxidative stress and excessive collagen synthesis. Piceatannol significantly improved pulmonary function and decreased oxidative injury as well as collagen synthesis in mice with PF. Mechanically, piceatannol treatment significantly inhibited the activation of JAK2/STAT3 signaling pathway in BLM-induced mice and TGF-β-induced lung fibroblasts. Additional findings also demonstrated that coumermycin A1 (C-A1), an agonist of JAK2, could abolish the effects of piceatannol on TGF-β-induced lung fibroblasts and reactivated the phosphorylation STAT3. Taken together, our study demonstrated that piceatannol could protect against oxidative injury and collagen synthesis during PF in a JAK2/STAT3 signaling pathway-dependent manner. [ABSTRACT FROM AUTHOR]

A unified phase diagram is presented for rod-coil diblock copolymer melts in the isotropic phase regime as a function of the asymmetric parameter. The study is based on free energy calculation, which incorporates three-dimensional spatial variations of the volume fraction with angular dependence. The wormlike-chain model is used in a self-consistent field treatment. Body-centered cubic, A15, hexagonal, gyroid, and lamellar structures where the rod segments are packed inside the convex rod-coil interface are found stable. As the conformational asymmetric parameter increases, the A15 phase region expands and the gyroid phase region reduces. The stability of the structures is analyzed by concepts such as packing frustration, spinodal limit, and interfacial curvature. [ABSTRACT FROM AUTHOR]

Abstract The paper studies the angle tracking control of the elbow joint and the end-point of the human musculoskeletal arm model. It uses a Hill-type planar model with six muscles and two links. During the motion, the gravity compensation is emphasized since it has significant influence on actual anthropomorphic arm system. An adaptive fuzzy sliding mode control method is proposed and applied to make the elbow joint and the end point of the human musculoskeletal arm model track certain angles. Through the adaptive fuzzy system, it may realize the adaptive approximation of switching scales of sliding mode controller so as to avoid chattering. Numerical simulations are performed in order to verify the proposed control method. Results show that accurate angle tracking control may well be accomplished by proposed sliding mode controller. [ABSTRACT FROM AUTHOR]

With the development of digital signal processes, the relative differences of PMSM single loop in control periods between the speed loop and current loops are becoming smaller or even vanishing. Therefore, cascade control schemes seem to be unnecessary. In addition, considering the effects of disturbances and the variety of moments of inertia, this paper proposes a scheme using an adaptive non-cascade control method to design the controller, which merges speed loop and q-axis current loop into one single loop. First, an extended state observer (ESO) is employed to estimate the disturbances of the system. The estimated value is used in the feedforward compensation design to improve the capability of system anti-disturbance. Then, considering the performance degradation caused by inertia change, an adaptive control scheme is developed. By using inertia identification technology, the feedforward compensation gain can be tuned automatically according to the identification value. Several groups of simulations and experiments are carried out and the results demonstrate the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

Integrated structural-electromagnetic optimisation design is an interesting area in the field of antenna design. Due to the urgent requirements on second-order sensitivity analysis to benefit the integrated iterative procedure, based on the authors' previous work, an analytic second-order partial derivative formula of electromagnetic performance - directivity with respect to surface nodal displacements for reflector antennas is deduced. In this formula, the electromagnetic performance is obtained by superposition of radiation integrals on each small triangular element. Then, a perturbation of surface nodal displacement is introduced to re-express the distorted radiation integral. By partially differentiating the distorted phase error in radiation integral with respect to nodal perturbation over the corresponding triangular element twice, the second-order partial derivative is derived. Two reflectors - an axis-symmetrical one and an offset one, are illustrated in simulation to show the second-order partial derivatives in contour plots. A comparative simulation is performed to illustrate its benefits in integrated structural-electromagnetic optimisation. [ABSTRACT FROM AUTHOR]

The perennial grass Pennisetum alopecuroides was degraded using a conventional heating method with sulfuric acid. The effects of temperature (150 to 200 °C), reaction time (30 to 210 min), acid concentration (2% to 10%), and solid-liquid ratio (1:10 to 1:4) were optimized for P. alopecuroides hydrolysis. The production of levulinic acid was strongly affected by variations in these parameters. The optimum conditions with respect to reaction temperature, time, acid concentration, and solid-liquid ratio were 190 °C, 60 min, 8%, and 1:6, respectively. The maximum levulinic acid yield using the optimum conditions was 50.49%. The residues obtained from various temperatures were also intensively characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric (TG) analyses. These results extend the current understanding of the bioconversion and utilization of renewable lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

A palladium-catalyzedintramolecular isoindolinone-forming aminooxygenationof alkenes with 1 atm of oxygen as oxidant is reported. A varietyof functionalized alkenes and carboxylic acids can be used, and highyields were observed. Preliminary mechanistic studies revealed thatthe aminooxygenation products were formed through the oxidation ofa C–PdIIspecies using a strong oxidant, peroxide,which is generated in situ from a Pd(OAc)2/bpy/O2/HOAc catalytic system. [ABSTRACT FROM AUTHOR]

We report on the synthesis of high-quality microporous/mesoporous BN material via a facile two-step approach. An extremely high surface area of 1687 m2 g-1 and a large pore volume of 0.99 cm3 g-1 have been observed in the synthesized BN porous whiskers. The formation of the porous structure was attributed to the group elimination of organic species in a BN precursor, melamine diborate molecular crystal. This elimination method maintained the ordered pore structure and numerous structural defects. The features including high surface area, pore volume and structural defects make the BN whiskers highly suitable for hydrogen storage and wastewater treatment applications. We demonstrate excellent hydrogen uptake capacity of the BN whiskers with high weight adsorption up to 5.6% at room temperature and at the relatively low pressure of 3 MPa. Furthermore, the BN whiskers also exhibit excellent adsorption capacity of methyl orange and copper ions, with the maximum removal capacity of 298.3 and 373 mg g-1 at 298 K, respectively. [ABSTRACT FROM AUTHOR]

Liquid fuel such as bio-gasoline derived from biomass is widely recognized as a potential substitution for the diminishing fossil fuels due to its abundance of raw materials and lower greenhouse gas emissions. In this work, Ni/HZSM-5 catalysts were developed by incipient impregnation method and applied in the bio-gasoline production by aqueous phase reforming of sorbitol. The effects of reaction temperature, hydrogen pressure and calcination temperature of the catalysts on the catalytic performance were investigated. The activity test results showed that the catalyst calcined at 500 °C had the maximal activity with 47.6% of the bio-gasoline yield and 76.4% of the total selectivity of lighter alkanes (C5-C6) at 240 °C and 4.0 MPa. The catalysts were characterized by N2 physical adsorption, H2 temperature-programmed reduction (H2-TPR), H2 temperature-programmed desorption (H2-TPD), and infrared spectroscopy (IR) techniques. The characterization results revealed that the catalyst calcined at 500 °C can provide optimum surface area and pore volume for the reaction. Moreover, 100% of the reducibility of Ni species was detected on the surface of HZSM-5, following by more nickel active sites, which led to a visible increase in the yield of bio-gasoline. [ABSTRACT FROM AUTHOR]

This paper points out an error in the principle figure and the waveform figure of the thermal resistance standard [EC747- 7, which describes the relation between the I-V curves and the temperature. It theoretically proves that the I-V-T curve of the standard contradicts the physical law. This contradiction is also revealed by experimental results. Finally, the correct I-V-T characteristic curve and the waveform figure at two different temperatures for the same transistor is given, which serves as the reference to correct the standard. [ABSTRACT FROM AUTHOR]