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A lattice structure is a typical high-strength lightweight material. In this work, the influence of materials, loading direction, gradient, and hybrid topology on the mechanical characteristics of lattice structures manufactured by additive manufacturing technology and the major factors determining lattice structure fatigue qualities are systematically reviewed. Additionally, studies focusing on the future direction of additively-manufactured lattice structures are presented, and prospective challenges with respect to designing and optimizing lattice structures are put forward. This review offers an advanced understanding of key factors affecting the mechanical properties of additively manufactured lattice structures and provides an indispensable basis for reliable applications of lattice structures. [ABSTRACT FROM AUTHOR]

New alkaloid, (E)-2-(hydroxyimino)-4-methylpentanamide (1) and a new cyclopentano[b] pyridine, 4-hydroxy-7-methyl-6,7-dihydro-5H-cyclopenta[c]pyridin-5-one (2), together with ten known compounds (3–12) were isolated from the mangrove soil-derived fungus Arthrinium sp. SCSIO 41305. Extensive spectroscopic analysis and X-Ray crystallographic analysis were used to elucidate the structure of (E)-2-(hydroxyimino)-4-methylpentanamide (1), including its absolute configuration. All the isolated compounds (1–12) were evaluated for their antimicrobial and enzyme inhibitory activities against acetylcholinesterase (AChE), neuraminidase (NAs), and phosphatidylinositol 3-kinase (PI3K). Among them, compounds 1 and 3 exhibited strong neuraminidase inhibitory activity with IC50 values of 12.04, 1.92 µmolL−1 (IC50 20 µmolL−1 for oseltamivir acid), while compounds 5, 6, 8, and 10 showed moderate neuraminidase inhibitory activity, and compounds 6–10 displayed weak enzyme inhibitory activities against PI3K. [ABSTRACT FROM AUTHOR]

Despite many publications devoted to the synchronization of vibrators or pendulums, there exist limited works considering the nonlinear vibrations of pendulums and vibrators coupled together. This paper is devoted to the synchronization and stability characteristics of a vibrating system with two vibrators mounted symmetrically on double pendulums. Utilizing the average method, the synchronization and stability criteria of the two vibrators are deduced. Further derivations indicate the synchronization of the pendulums is based on the synchronous states of the vibrators. Three kinds of possible synchronization types of the two pendulums are found: anti-phase synchronization under zero phase difference, in-phase synchronization under π phase difference, and partial synchronization when the phase difference of two vibrators falls into the open interval of zero and π. These synchronous states are all observed in experiments. Furthermore, the synchronization mechanism of the vibrator-pendulum system is explained by the regulating effect of the dimensionless coupling torque between the two vibrators. This regulating effect ensures the synchronization of the vibrators. After the vibrators are synchronized, the system further selects the synchronous states of the pendulums according to the phase difference between the two vibrators. [ABSTRACT FROM AUTHOR]

For a vibrating system where the pendulum and vibrators are coupled together, the relevant dynamic model and the corresponding synchronization problem are rarely studied, due to its complex dynamic coupling relationships. In this paper, a vibrator–pendulum coupling system is proposed to study its synchronization principle; here, the pendulum is driven by the synchronous motion of the two vibrators directly. By exploiting the system motion differential equations and their vibration responses, the synchronization criterion of the two vibrators is deduced via the average method. After that, the stability criterion for the synchronous states is presented according to the convergence and divergence characteristics of the perturbed differential equation in the balanced state. Based on the theoretical results, the synchronous stable states and motion characteristics of the system under different parameter conditions are discussed by numerical qualitative analyses, and the reasonable parameters matching principles in designing the real vibrating machine are provided. A series of numerical simulations and experiments are further given to examine the validity of the theoretical methods and the obtained results. The dynamic model and research results presented in this paper can be applied to design a new kind of vibrating jaw crusher; in this case, the pendulum is served as the moving jaw and can work with its swing motion trajectory under the premise of the stable zero-phase difference between the two vibrators. [ABSTRACT FROM AUTHOR]

Purpose: For the vibrating machine with linear motion, the traditional driving method is utilizing the self-synchronization of double vibrators, or using a single motor to drive a pair of forced synchronization vibrators by the gear meshing. In this paper, we propose and study a special linear motion vibrating system (VS) driven by only the single vibrator, where the vibrator is mounted on a pendulum (so called pendulum bob) and no synchronization strategy is involved. Methods: The Lagrange's equation is used to obtain the motion differential equations of the system. Based on the vibration mechanics principle, the theory condition to guarantee the linear motion of the main working rigid frame (MWRF) is deduced, and the double frequency vibrating transmission (VT) between the pendulum and the MWRF is investigated. Simultaneously, some qualitative analyses are given to further reveal the special motion characteristics of the system by numeric. The the Runge-Kutta routine is applied directly to the motion differential equations of the system and the experiment is carried out to further verify the validity of the theoretical results. Results: The results show that the special linear motion of the MWRF can be realized for the proposed dynamic model when satisfying the corresponding theory condition in the absence of self-synchronous or forced synchronization strategy, and in this case the system stability is relatively strong. Conclusion: To guarantee the linear motion of the MWRF, the stiffness and damping, generating from the connection coupling between the pendulum and the MWRF, should be minimized. The present work can offer a reference to design a new kind of vibrating machine with linear motion. In engineering, the desired linear motion vibration amplitude of MWRF can be reached by adjusting the parameters of vibrator and considering the theory condition of implementing linear motion. [ABSTRACT FROM AUTHOR]

A new oxygenated tricyclic cyclopiazonic acid (CPA) alkaloid, asperorydine Q (1), along with seven known compounds, namely, asperorydines O (2) and J (3), speradine H (4), cyclopiamides A (5) and H (6), saadamysin (7), and pyrazinemethanol (8), were isolated from the coral-associated Aspergillus flavus GXIMD 02503. The structures were elucidated by physicochemical properties and comprehensive spectroscopic data analysis. Compounds 1–5 and 7–8 exhibited potent inhibition of lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) with the IC50 values ranging from 6.5 to 21.8 µmol L−1. In addition, the most potent one, pyrazinemethanol (8), dose-dependently suppressed receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation without obvious cytotoxicity in bone marrow macrophages cells (BMMCs), suggesting it is a promising lead compound for the treatment of osteolytic diseases. [ABSTRACT FROM AUTHOR]

Transition-metal-catalyzed homogeneous dehydrogenation and isomerization are common organic molecular activation reactions. Palladium hydrides are good olefin isomerization catalysts but are usually short-lived species under redox-active dehydrogenation conditions. Here, we show that Pd-H in the presence of an N-heterocyclic carbene ligand and an alkene regulator enables transfer-dehydroaromatization, avoiding the homo-disproportionation pathway. The desired product is obtained with up to 99:1 selectivity, and the exo-to-endo olefin isomerization can be carried out in one pot. In contrast to previously reported methods that rely on the efficient removal of Pd-H, the approach reported herein benefits from the steric effects of the N-heterocyclic carbene and the choice of alkene to regulate the competing reactivity of allylic C‒H activation and hydropalladation. This method circumvents the challenges associated with tedious olefin separation and a low exo-to-endo olefin isomerization ratio and expands the scope to include challenging endo- and exo-cyclic olefins under mild, neutral, and oxidant-free conditions. Overall, herein, we provide a strategy to synthesize (hetero)aromatic compounds via chemoselective dehydrogenation of cyclic alkenes over ketones and the dehydrogenative Diels-Alder reaction of a cyclic enamine. Aromatic compounds can be prepared via dehydrogenation of cyclic compounds. Here the authors report the dehydroaromatization of endocyclic and exocyclic olefins via chain-walking isomerization and transfer-dehydrogenation catalyzed by palladium N-heterocyclic carbene complexes in the presence of alkenes as sacrificial reagents. [ABSTRACT FROM AUTHOR]

This paper aims at investigating the times–frequency synchronization of the three exciters in a far super-resonant vibrating system. Based on the asymptotic method, the Bogoliubov standard formal equations of the three exciters are constructed, and the criterion of the double-frequency synchronization for the simplified form is deduced. Meanwhile, the stability criterion of the synchronous states is derived by complying with the Routh–Hurwitz principle. The stability characteristics of double-frequency synchronization are qualitatively discussed by numeric, including the stable phase differences and stability ability among the three exciters. Finally, the corresponding simulations and experiments for the double-frequency synchronization are carried out, respectively. According to the comparisons and analyses of results for theory, numeric, simulation and experiment, including the stable phase differences among the three exciters, responses of the system, synchronous rotational velocities, etc., it is shown that the feasibility of the used theory method and the validity of the obtained results are verified. This paper can also provide a theoretical reference for designing new types of vibrating equipment in engineering with two different driving frequencies. [ABSTRACT FROM AUTHOR]

Hair follicles are the basis of the formation of Hu sheep pattern. This study was to employ whole transcriptome sequencing to screen differentially expressed long non-coding RNAs (lncRNAs) between three wave patterns in lambskin. In this study, three groups of 2-day-old Hu sheep were selected from full-sib individuals that included small, medium, and large waves, and hair follicle tissues were collected from dorsal side of Hu sheep. LncRNA and mRNA expression profiles were analyzed by whole transcriptome sequencing technology. 33, 31, and 41 differentially expressed lncRNAs were selected between large and medium, medium and small, and large and small, respectively. 458, 481, and 498 differentially expressed mRNAs were found between large and medium, medium and small, and large and small, respectively, by RNA-seq analysis. qRT-PCR results of 16 randomly selected lncRNAs and mRNAs were similar to the sequencing results. Correlation analysis of lncRNA and mRNA expression showed that, several lncRNAs may be enriched for hair follicle such as Wnt, mTOR, Notch signaling pathways. Our results aid in excavation of mRNAs and lncRNAs in hair follicle, and providing a basis for future study on pattern formation mechanisms. [ABSTRACT FROM AUTHOR]

Sheep colibacillosis is one of the most common bacterial diseases in large-scale sheep farms. In this study, we orally administered Escherichia coli F17 (E. coli F17) to lambs to obtain antagonistic and sensitive individuals. We used RNA-seq to screen for differential circRNAs in the spleens of both antagonist and sensitive individuals to explore the effect of circRNA on anti-diarrhoea in sheep. The results showed that 60 differentially expressed (DE) circRNAs were screened by RNA-seq in the spleen of antagonistic and sensitive lambs, among which 31 were up-regulated and 29 were down-regulated; q-PCR was used to validate the relative expression levels of six randomly selected circRNAs in antagonist and susceptible lambs and found to be consistent with the results of RNA-seq. Using Miranda analysis of circRNA-miRNA-mRNA interactions, we found a certain target relationship between 6 circRNAs, 5 miRNAs and 9 mRNAs. The relative expression levels of mRNA in antagonistic and sensitive lambs were verified by q-PCR and were consistent with the results of RNA-seq. This study explored the expression profile of circRNA in the spleen of an antagonistic and susceptible lamb with diarrhoea and found that differentially expressed circRNAs were helpful for determining how the lambs resist the pathogenesis of diarrhoea and provided a scientific basis for lambs to resist diarrhoea. [ABSTRACT FROM AUTHOR]