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Further insights on the secondary metabolites of a soft coral-derived fungus Aspergillus versicolor under the guidance of MS/MS-based molecular networking led to the isolation of seven known cycloheptapeptides, namely, asperversiamides A–C (1–3) and asperheptatides A–D (4–7) and an unusual pyrroloindoline-containing new cycloheptapeptide, asperpyrroindotide A (8). The structure of 8 was elucidated by comprehensive spectroscopic data analysis, and its absolute configuration was determined by advanced Marfey’s method. The semisynthetic transformation of 1 into 8 was successfully achieved and the reaction conditions were optimized. Additionally, a series of new derivatives (10−19) of asperversiamide A (1) was semi-synthesized and their anti-tubercular activities were evaluated against Mycobacterium tuberculosis H37Ra. The preliminary structure−activity relationships revealed that the serine hydroxy groups and the tryptophan residue are important to the activity.

The discovery of a method to separate isotopologues, molecular entities that differ in only isotopic composition

Marine organisms often produce a variety of metabolites with unique structures and diverse biological activities that enable them to survive and struggle in the extremely challenging environment. During the last two decades, our group devoted great effort to the discovery of pharmaceutically interesting lead compounds from South China Sea marine plants and invertebrates. We discovered numerous marine secondary metabolites spanning a wide range of structural classes, various biosynthetic origins and various aspects of biological activities. In a series of reviews, we have summarized the bioactive natural products isolated from Chinese marine flora and fauna found during 2000-2012. The present review provides an updated summary covering our latest research progress and development in the last decade (2012-2022) highlighting the discovery of over 400 novel marine secondary metabolites with promising bioactivities from South China Sea marine organisms.

Here, we report an asymmetric electrochemical organonickel-catalyzed reductive cross-coupling of aryl aziridines with aryl iodides in an undivided cell, affording β-phenethylamines in good to excellent enantioselectivity with broad functional group tolerance. The combination of cyclic voltammetry analysis of the catalyst reduction potential as well as an electrode potential study provides a convenient route for reaction optimization. Overall, the high efficiency of this method is credited to the electroreduction-mediated turnover of the nickel catalyst instead of a metal reductant-mediated turnover. Mechanistic studies suggest a radical pathway is involved in the ring opening of aziridines. The statistical analysis serves to compare the different design requirements for photochemically and electrochemically mediated reactions under this type of mechanistic manifold.

In this paper, TC4/AZ91D bimetallic composites has been prepared by liquid–solid compound casting process adapting various thickness of Cu coating. The effects of Cu coating thickness on the evolution of interface microstructures and joint mechanical properties are investigated. The results indicate that metallurgical bonded joints are obtained with Cu coating thickness ranging from 36.7 to 51.4 μm. With the increase of Cu coating thickness, the interface microstructure evolves from δ-Mg + Mg2Cu eutectic structure to Mg–Cu intermetallic compound (IMC) Cu2Mg + Mg2Cu and Mg–Al–Cu ternary intermetallic compound. The calculation results of formation enthalpy and chemical potential of Mg–Al–Cu system suggest that Cu element prefers to react with Mg element and formed Mg–Cu IMC. In particular, when Cu coating thickness reaches 36.7 μm, the average shear strength of the bimetal reaches a maximum of 65.3 MPa. Further increasing Cu coating thickness leads to the generation of thick Mg2Cu IMC layer and Mg2Cu + Cu2Mg mixed IMC layer which are proved to be harmful to the shear strength of TC4/AZ91D bimetals. All the fracture surfaces of the bimetallic composites exhibite to have a brittle fracture morphology. However, the fracture location is different with each other. For Cu coating thickness of 36.7 μm, the interface fractures at the δ-Mg + Mg2Cu eutectic structure, while the interface fractures at the Cu2Mg + Mg–Al–Cu ternary intermetallic layers when Cu coating thickness is 44.2 μm and 51.4 μm.

Marine natural products play critical roles in the chemical defense of many marine organisms and are essential, reputable sources of successful drug leads. Sixty-seven 14-membered resorcylic acid lactone derivatives 3–27 and 30–71 of the natural product zeaenol (1) isolated from the marine-derived fungus Cochliobolus lunatus were semisynthesized by chlorination, acylation, esterification, and acetalization in one to three steps. The structures of these new derivatives were established by HRESIMS and NMR techniques. All the compounds (1–71) were evaluated for their antialgal and antiplasmodial activities. Among them, 14 compounds displayed antifouling activities against adhesion of the fouling diatoms. In particular, 9 and 34 exhibited strong and selective inhibitory effects against the diatoms Navicula laevissima and Navicula exigua (EC50 = 6.67 and 8.55 μmol/L), respectively, which were similar in efficacy to those of the positive control SeaNine 211 (EC50 = 2.90 and 9.74 μmol/L). More importantly, 38, 39, and 69–71 showed potent antiplasmodial activities against Plasmodium falciparum with IC50 values ranging from 3.54 to 9.72 μmol/L. Very interestingly, the five antiplasmodial derivatives displayed non-toxicity in the cytotoxicity assays and the zebrafish embryos model, thus, representing potential promising antiplasmodial drug agents. The preliminary structure–activity relationships indicated that biphenyl substituent at C-2, acetonide at positions C-5′ and C-6′, and tri- or tetra-substituted of acyl groups increased the antiplasmodial activity. Therefore, combining evaluation of chemical ecology with pharmacological models will be implemented as a systematic strategy, not only for environmentally friendly antifoulants but also for structurally novel drugs.

Natural products are well established as an important resource and play an important role in drug discovery. Here, two pyrrolinone-fused benzoazepine alkaloids, (+)-asperazepanones A (1) and B (2) with a 6/7/5 ring system, together with the artifact (−)-asperazepanone A (1), were isolated from the coral-derivedAspergillus candidusfungus. Their structures including absolute configurations were elucidated by extensive spectroscopic methods, single crystal X-ray diffraction, and ECD calculations. Furthermore, total syntheses of (±)-1and (±)-2have been achieved starting from the commercially L-aspartic acid diethyl ester hydrochloride and monoethyl malonate in 7 and 8 steps, respectively. The key step in the syntheses was an intramolecular Friedel-Crafts reaction to build the unique tricyclic skeleton. Interestingly, (+)-2not only showed obviously inhibitory activity against NO production, but also inhibited potent LPS-induced expression of TNF-α and IL-6 at the concentration of 0.1 μM. It thus represents a potentially promising lead for anti-inflammatory drug discovery.

The morphology of eutectic silicon in solidification microstructure is critical to the performance of Al-Si-based alloys. Simulating eutectic Si phase formation has been a challenge in ICME (integrated computational materials engineering) based design and manufacturing of solidification products of Al-Si-based alloys. In this study, our previous three-dimensional (3-D) cellular automaton (CA) model for α-Al dendritic growth was extended to include eutectic (α-Al + Si) transformation in multi-dendrite domains, providing a complete solidification simulation of critically important Al-Si based alloys. The quantitative results of the Si phase in the eutectic microstructure were experimentally validated using scanning electron microscopy and deep etching techniques. The simulation results show a good agreement with the experimental observations and calculations by the Scheil model and lever rule. This 3-D CA model is useful for predicting and optimizing the solidification microstructure including eutectic transformation during solidification processing such as casting, potentially welding, and additive manufacturing.

Background Liver fibrosis is an outcome of restoring process in chronic liver injury. Human amniotic mesenchymal stem cells (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating liver fibrosis. This study aimed to explore the effect and mechanism of hAMSCs on liver fibrosis. Methods hAMSCs were transplanted into carbon tetrachloride (CCl4)-induced liver fibrosis mice via tail vein, and the effects of hAMSCs on hepatic fibrosis were assessed. The effects of hAMSCs and hAMSCs conditional medium (CM) on the activation of hepatic stellate cells (HSCs) were investigated in vivo and in vitro. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may inhibit the activation of HSCs. Finally, the underlying mechanisms were explored by assessing IGF-1R/PI3K/AKT and GSK3β/β-catenin signaling pathways in the activated HSCs (LX-2) with hAMSCs and hAMSCs transfected with corresponding siRNAs. Results Our results showed that hAMSCs possessed the characterizations of mesenchymal stem cells. hAMSCs significantly reduced liver fibrosis and improved liver function in mice by inhibiting HSCs activation in vivo. Both hAMSCs and hAMSC-CM remarkably inhibited the collagen deposition and activation of LX-2 cells in vitro. Antibody array assay showed that insulin-like growth factor binding protein-3 (IGFBP-3), Dickkopf-3 (DKK-3), and Dickkopf-1 (DKK-1) were highly expressed in the co-culture group and hAMSC-CM group compared with LX-2 group. Western blot assay demonstrated that IGFBP-3, DKK-3, and DKK-1 derived from hAMSCs inhibit LX-2 cell activation through blocking canonical Wnt signaling pathway. Conclusions Our results demonstrated that IGFBP-3, Dkk3, and DKK-1 secreted by hAMSCs attenuated liver fibrosis in mice through inhibiting HSCs activation via depression of Wnt/β-catenin signaling pathway, suggesting that hAMSCs or hAMSC-CM provides an alternative therapeutic approach for the treatment of liver fibrosis.

The solid–liquid compound casting (SLCC) was used to produce Ti/Mg bimetal via hot dip Zn coating, and the interfacial microstructures and mechanical properties of the Mg/Ti bimetal were investigated in this work. The scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) reveal that there is no interlayer metallurgical reaction when the pouring temperature is 670 °C. As the pouring temperature increases to 710 and 750 °C, the thickness of the metallurgical interfacial zone is about 130 and 310 µm, respectively. The interfacial zone is mainly consists of α-Mg and τ-TiAlZn coexistence phases. Thermodynamic models are established to explain the evolution mechanism of α-Mg and τ-TiAlZn coexistence phases. It is concluded that the formation process of α-Mg and τ-TiAlZn phase coexist is as follows: TiZn5(s)-to-TiZn5(l), and then α-Mg and τ-TiAlZn phases coexist. While the sequence of the phases that formed in the Ti–Al–Zn ternary system is TiAl3→τ-TiAlZn, this is based on the fact that the Al atoms are used up at the interfacial zone. The highest shear strength of Zn-coated TC4/AZ91D bimetallic material is up to 34.24 Mpa when the pouring temperature is 710 °C.

Natural products derived from marine microorganisms have received great attention as a potential resource of new compound entities for drug discovery. The unique marine environment brings us a large group of sulfur-containing natural products with abundant biological functionality including antitumor, antibiotic, anti-inflammatory and antiviral activities. We reviewed all the 484 sulfur-containing natural products (non-sulfated) isolated from marine microorganisms, of which 59.9% are thioethers, 29.8% are thiazole/thiazoline-containing compounds and 10.3% are sulfoxides, sulfones, thioesters and many others. A selection of 133 compounds was further discussed on their structure–activity relationships, mechanisms of action, biosynthesis, and druggability. This is the first systematic review on sulfur-containing natural products from marine microorganisms conducted from January 1987, when the first one was reported, to December 2020.

The strong antibacterial, antiviral and anticancer activities demonstrated by quinolones make them promising lead structures and important synthetic targets for drug discovery. Here, we report, to the best of our knowledge, the first scalable total synthesis of antiviral (+)-aniduquinolone A, possessing a 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one skeleton. This synthetic strategy explores E-stereoselective Horner–Wadsworth–Emmons (HWE) olefination as the key step to assemble isopropenyl substituted tetrahydrofuran onto the 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one core, which is built by highly diastereoselective intramolecular aldol reaction. Moreover, two sets of stereoisomers of aniduquinolone A with substantially overlapping NMR data were synthesized completely and assigned unambiguously by comprehensive analysis of both their spectroscopic and X-ray diffraction data. Unexpectedly, aflaquinolones A, C, and D that feature different 2,4-dimethyl cyclohexanone moieties were transformed successfully from (+)-aniduquinolone A by treating with TFA. The methodology delineated herein can be applied broadly to the synthesis of natural alkaloids containing the core structure of 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one.

Nowadays, the sound source localization is widely applied in various fields, with a focus on arrays or algorithms. Meanwhile, acoustic metasurfaces have recently attracted enormous interest in material science. This paper proposed a kind of piezoelectric acoustic metasurface, whose structure is theoretically proved to be useful in sound field orientation or sound source localization. The metasurfaces consist of forty units made up of a resonance-like cavity and a piezoelectric composite sheet in air. By scanning through space and frequency, it has been investigated that the effective interval can reach $$30^\circ \le \theta \le 150^\circ $$ and $$-200\le x\le 200\,\hbox {cm}$$ under far-field and near-field scenario, respectively. Meanwhile, the bandwidth of the structure was evaluated to be up to 800–900 Hz in both scenarios. In addition, this paper analyzed three factors affecting the interval: frequency, the size of the metasurface, and the number of elements. The results of this paper has opened up a new way for sound source localization and metasurfaces.

Automatically generating captions for videos faces a huge challenge since it is a cross-modal cross task that involves vision and texts. Most of the existing models generate the captioning words merely based on the video visual content features, ignoring the important underlying semantic information. The relationship between explicit semantics and hidden visual content is not holistically exploited, thus hardly describing fine-grained caption accurately from a global view. To better extract and integrate the semantic information, we propose a novel encoder-decoder framework of bi-directional long short-term memory with attention model and conversion gate (BiLSTM-CG), which transfers auxiliary attributes and then generates detailed captioning. Specifically, we extract semantic attributes from sliced frames in a multiple-instance learning (MIL) manner. MIL algorithms attempt to learn a classification function that can predict the labels of bags and/or instances in the visual content. In the encoding stage, we adopt 2D and 3D convolutional neural networks to encode video clips, and then feed the concatenate features into a BiLSTM. In decoding stage, we design a CG to adaptively fuse semantic attributes into hidden features at word level, and a CG can convert auxiliary attributes and textual embedding for video captioning. Furthermore, the CG has an ability to automatically decide the optimal time stamp to capture the explicit semantic or rely on the hidden states of the language model to generate the next word. Extensive experiments conducted on the MSR-VTT and MSVD video captioning datasets demonstrate the effectiveness of our method compared with state-of-the-art approaches.

A new tetracyclic triterpenoid (1) was isolated from the fresh bark of Ailanthus altissima. The structure was elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques and high-resolution mass spectrometry.

Based on the strategy of diversity-oriented synthesis and the structures of natural product pimprinine and streptochlorin, two series of novel pimprinine derivatives containing 1,3,4-oxadiazole-5-thioether moieties were efficiently synthesized under the optimized reaction conditions. Biological assays conducted at Syngenta showed the designed derivatives displayed an altered pattern of biological activity, of which 5h was identified as the most promising compound with strong activity against Pythium dissimile and also a broad antifungal spectrum in primary screening. Further structural optimization of pimprinine and streptochlorin derivatives is well under way, aiming to discover synthetic analogues with improved antifungal activity. Two series of novel pimprinine derivatives containing 1,3,4-oxadiazole-5-thioether moieties were efficiently synthesized through diversity-oriented synthesis strategy under the optimized conditions. Biological assays showed the designed derivatives exhibited potential activity.

Two new lignans (1, 2) were isolated from the fresh bark of Ailanthus altissima. The structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques and high-resolution mass spectrometry.

Clay minerals are ubiquitous in soil and sediments, and play important roles in environmental processes. Virtually all clay minerals contain some Fe, either in the crystal structure or adsorbed at the surface of the clay minerals, which could promote many reactions on the clay minerals. The interaction between Fe containing clay mineral and its surrounding contaminants would greatly affect the transformation and toxicity of the contaminants. While it is certain that the Fe plays important roles in the fate of the contaminants, relative qualitative and quantitative assessment of these processes is limited. Based on the overall toxicity variation, this paper reviews the active areas of the researches on the interactions between Fe containing clay mineral and contaminants, and provides perspectives for future work.

Microplastics, as a group of emerging contaminants, are receiving growing attention. During the last decade, their occurrence and toxicity in aquatic ecosystems have been intensively studied and reviewed, but less attention has been paid on soil ecosystems. Given the importance of soil ecosystems and the call for increasing research on soil from scientific communities, it is predicted that relevant studies will boom in the following years. The present review intends to provide a comprehensive overview of current knowledge on microplastic pollution in soil environments. We critically summarize the source, contamination level and fate of microplastics in (industrial and arable) soils. Then, we thoroughly describe what effects have been observed on soil microbes, animals and plants, and analyze what insights we can get from available information. Finally, we identify knowledge gaps that need to be filled and give suggestions for future research.

Directional solidification experiments were performed on Al–Si–Mg alloys to examine the effect of compositional variation on dendritic growth and to develop a novel growth model for the prediction of primary dendrite arm spacing in solidification microstructures. Instead of relying on the growth restriction factor or inoculant particle efficacy, this model examines solute effects to describe the final primary dendritic arm spacing. Increased Mg concentration was shown to decrease the dendritic growth velocity by decreasing constitutional undercooling. Solute enrichment at the solid/liquid interface was shown to limit lateral coarsening of primary dendrite arms and create a region of local solute depletion. This phenomenon allowed increased nucleation due to an increase in the resulting local liquidus temperature, and ultimately produced a refined primary dendrite arm spacing. Primary and secondary dendrites were measured and quantitatively analyzed in validation of the model. The model, which shows increased accuracy compared to existing models, was developed with aid of the three-dimensional cellular automaton method and experimentally verified.

A three-dimensional (3D) quantitative cellular automaton (CA) model was developed to simulate dendritic growth during solidification processing of ternary alloys. A detailed method was proposed to solve solute diffusion and calculate the solid fraction for ternary alloys during solidification. The present model has been shown to accurately predict dendrite morphologies and solute distributions of both single equiaxed dendrite and columnar dendrites during solidification. The model was also used to study the influence of the concentration of a third component (Mg in the Al-Si-Mg system) on dendritic growth. With increasing Mg concentration, the steady-state dendrite tip growth velocity was shown to decrease, resulting in a shorter primary dendrite length. The 3D CA simulation results agree well with the prediction of the LGK theoretical model. Multi-columnar dendrite growth was simulated with different cooling rates. Primary and secondary dendrite morphology was shown to have little variation at low cooling rates (1.0 to 2.0 K/s) and a constant undercooling. The average secondary dendrite arm spacing was shown to decrease with the increase of cooling rate within this range. The 3D CA simulation results are in good agreement with the experimental directional solidification experiments of a commercial A356 (Al-7 wt pct Si-0.3 wt pct Mg).

The formation, stability and in vitro digestion of milk fat globule membrane (MFGM) proteins stabilized emulsions with 0.2 wt% β-carotene were investigated. The average particle size of β-carotene emulsions stabilized with various MFGM proteins levels (1%, 2%, 3%, 4%, 5% wt%) decreased with the increase of MFGM proteins levels. When MFGM proteins concentration in emulsions is above 2%, the average particle size of β-carotene emulsions is below 1.0 μm. A quite stable emulsion was formed at pH 6.0 and 7.0, but particle size increased with decrease in acidity of the β-carotene emulsion. β-carotene emulsions stabilized with MFGM proteins were stable with a certain salt concentrations (0–500 mMNaCl). β-carotene emulsions were quite stable to aggregation of the particles at elevated temperature and time (85 °C for 90 min). At the same time, β-carotene emulsions were stable against degradation under heat treatment conditions. In vitro digestion of β-carotene emulsion showed the mean particle size of β-carotene emulsions stabilized with MFGM proteins in the simulated stomach conditions and intestinal conditions is larger than that of initial emulsions and simulated mouth conditions. Confocal laser scanning microscopy of β-carotene MFGM proteins emulsions also showed the corresponding results to different vitro digestion model. There was a rapid release of free fatty acid (FFA) during the first 10 min and after this period, an almost constant 70% digestion extent was reached. Approximately 80% of β-carotene was released within 2 h of incubation under the simulated intestinal fluid. These results showed that MFGM protein can be used as a good emulsifier in emulsion stabilization, β-carotene rapid release as well as lipophilic bioactive compounds delivery.

Automatic epileptic seizure detection based on electroencephalogram is crucial to epilepsy diagnosis and treatment. However, the large numbers of time series make it quite challenging to establish a high performance automatic detection method. Considering different physiological states of the brain could be characterized by distinct combinations or interactions of similar discontinuous local temporal patterns, a novel framework based on biclustering for automatic epileptic seizure detection is proposed in this paper. First, the CC algorithm is used to identify similar discontinuous local temporal patterns. Then, the bicluster membership matrix using a new similarity measurement is constructed to reduce the dimensionality. At last, the ELM classifier is adopted to discriminate between epileptic seizure and seizure-free EEG signals. With extensive comparative studies and evaluations on the publicly available Bonn epileptic EEG dataset, it indicates that the proposed framework could not only automatically detect or predict an epilepsy seizure with high performances with respect to accuracy, robustness and efficiency, but also implicitly provide valuable knowledge for studying the mechanisms of epilepsy.

A two-dimensional cellular automaton–finite volume model was developed to simulate dendrite growth of Al-3 wt pct Cu alloy during solidification to investigate the effect of temperature and fluid flow on dendrite morphology, solute concentration distribution, and dendrite growth velocity. Different calculation conditions that may influence the results of the simulation, including temperature and flow, were considered. The model was also employed to study the effect of different undercoolings, applied temperature fields, and forced flow velocities on solute segregation and dendrite growth. The initial temperature and fluid flow have a significant impact on the dendrite morphologies and solute profiles during solidification. The release of energy is operated with solidification and results in the increase of temperature. A larger undercooling leads to larger solute concentration near the solid/liquid interface and solute concentration gradient at the same time-step. Solute concentration in the solid region tends to increase with the increase of undercooling. Four vortexes appear under the condition when natural flow exists: the two on the right of the dendrite rotate clockwise, and those on the left of the dendrite rotate counterclockwise. With the increase of forced flow velocity, the rejected solute in the upstream region becomes easier to be washed away and enriched in the downstream region, resulting in acceleration of the growth of the dendrite in the upstream and inhibiting the downstream dendrite growth. The dendrite perpendicular to fluid flow shows a coarser morphology in the upstream region than that of the downstream. Almost no secondary dendrite appears during the calculation process.

A cellular automaton (CA)–finite difference model is developed to simulate dendrite growth and solute diffusion during solidification process in the molten pool of Al-Cu alloy. In order to explain the interaction between the dendritic growth and solute distribution, a series of CA simulations with different solute diffusion velocity coefficients are carried out. It is concluded that the solute concentration increases with dendrite growing and solute accumulation in the dendrite tip. Converged value of the dendrite tip growth velocity is about 480 μm/s if the mesh size is refined to 2 μm or less. Growth of the primary dendrite and the secondary dendrite is mainly influenced by solute diffusion at the dendrite tips. And growth of secondary and tertiary dendrites is mainly influenced by solute diffusion at interdendrite.

Welding porosity defects significantly reduce the mechanical properties of welded joints. In this paper, the hydrogen porosity evolution coupled with dendrite growth during solidification in the molten pool of Al-4.0 wt pct Cu alloy was modeled and simulated. Three phases, including a liquid phase, a solid phase, and a gas phase, were considered in this model. The growth of dendrites and hydrogen gas pores was reproduced using a cellular automaton (CA) approach. The diffusion of solute and hydrogen was calculated using the finite difference method (FDM). Columnar and equiaxed dendrite growth with porosity evolution were simulated. Competitive growth between different dendrites and porosities was observed. Dendrite morphology was influenced by porosity formation near dendrites. After solidification, when the porosities were surrounded by dendrites, they could not escape from the liquid, and they made pores that existed in the welded joints. With the increase in the cooling rate, the average diameter of porosities decreased, and the average number of porosities increased. The average diameter of porosities and the number of porosities in the simulation results had the same trend as the experimental results.

The marine mangrove Xylocarpus granatum is used as a folk medicine and is rich in bioactive limonoids. The quantitative determination of the chemical composition and distribution of limonoids in different parts of X. granatum fruit (fruit peel, seed coat, seed kernels, seed, and fruit) is significant for authentication and quality control purposes. However, the quantitative determination of limonoids in X. granatum has not yet been reported. In this study, a chemometric-assisted liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous determination of 17 limonoids to reveal the chemical composition and distribution in different parts of X. granatum fruit. Ultrasonic-assisted extraction, optimized by response surface methodology (RSM), was more accurate than the general one-variable-at-a-time method. The overall distribution of 17 limonoids in different parts of X. granatum fruit had the following order: seed kernels > seed > fruit, and 13 limonoids showed a rank order of seed kernels > seed > fruit > fruit peel > seed coat. Furthermore, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to analyze the LC–MS/MS data and provide a chemometric model for easy visualization and interpretation to classify the different parts of X. granatum fruit. In addition, the study indicated that the chemometric-assisted strategy, consisting of RSM, PCA, and OPLS-DA for the development, optimization, and data analysis of multicomponent quantitation by LC–MS/MS, is effective and feasible. This study provided the chemical composition and distribution evidence for the authentication and quality control of X. granatum fruit.

Molecular epigenetic approach activates silent gene cluster producing dimeric bis-spiro-azaphilones in Chaetomium globosum CBS148.51

Six known quassinoids were isolated from the bark of Ailanthus altissima. Their structures were elucidated by spectroscopic methods. Compounds 1–6 were screened for their antitumor activities evaluated by MTT assay.

2060 Al–Cu–Li alloy plates with 2- and 1-mm thickness were welded by a fiber laser beam. The weld microstructure features and the mechanical properties such as microhardness and tensile strength of 2060 Al–Cu–Li alloy laser beam-welded joint were investigated to study the influence of welding parameters on the weld bead. By microstructure and mechanical property analysis, it is found that weld width as well as penetration depth increases with the increase of laser power when the welding speed is constant. The microstructures of the fusion line and fusion zone show similar dendrite morphologies with traditional cast structure under the thermal cycling. Fine grain zone can be observed near the fusion line. Welding porosities exist in the microstructure of 2060 Al–Cu–Li laser beam-welded joint. Porosity ratio increases at first, and then declines, and then increases again with the increase of laser power. The larger heat input causes the lower microhardness distribution of the corresponding joint. The optimized welding parameters of fiber laser beam welding of 2- and 1-mm-thick 2060 Al–Cu–Li alloys are 2500 W and 3 m/min and 2300 W and 4 m/min, respectively.

The synthesis of novel coumarin[8,7-e][1,3]oxazine derivatives through a microwave-assisted three-component one-pot Mannich reaction is described in this study. All the target compounds were evaluated in vitro for their antifungal activity against Botrytis cinerea, Colletotrichum capsici, Alternaria solani, Gibberella zeae, Rhizoctonia solani, and Alternaria mali. The preliminary bioassays showed that 5e, 5m, and 5s exhibited good antifungal activity and the most active compound was 5m with an [Formula: see text] value as low as 2.1 nM against Botrytis cinerea.

A new limonoid, named granaxylocartin A (1), was isolated from the seeds of Xylocarpus granatum, and the structure was elucidated on the basis of one- and two-dimensional NMR (including 1H, 13C NMR, DEPT, 1H–1H COSY, HSQC, HMBC, and NOESY).

The original version of the article unfortunately contained a mistake in Fig. 3. In this figure, norank_o_DS-100 and Niastella were mistakenly labelled with α-Proteobacteria and Firmicutes, respectively. The correct lineage is given below.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Numerical and experimental investigations of multi-layer laser-MIG hybrid welding for Fe36Ni Invar alloy were presented in this paper. The multi-layer laser-MIG hybrid welding experiments with different parameters were conducted for the 19.5-mm-thick Invar plates. A finite element (FE) model was established to predict the temperature field, residual stress, and deformation distribution during and after welding. A plane-conical combined heat source model was used to simulate the laser-MIG hybrid welding process. Different numbers of welding layers were chosen to study the effect of welding layer on the temperature field, residual stress, and deformation distribution. It was found that the maximum residual stress of Invar plates after laser-MIG hybrid welding is 300 MPa and maximum deformation is 0.4 mm, so that laser-MIG hybrid welding can be used in actual manufacture of Invar moulds.

Five acylation derivatives (1a–1e) were prepared by acylation of the bioactive natural product hypoxylin A (1) isolated from Halorosellinia oceanicum. Compounds 1a and 1b were epimers with the configuration inversion of C-10 in 1b. Hypoxylin A (1) and 1a–1e exhibited potent lethal activity toward the brine shrimp Artemia salina. Hypoxylin A (1) also showed cytotoxicity against tumor cell line A549 with an IC50 value of 5.6 μg/mL. The antibacterial activities of these compounds were also evaluated, and none of them were active.

In the plasma of dairy cows with 1-5 points of lameness, the mineral elements [calcium (Ca), iron (Fe), copper (Cu), zinc (Zn), iodine (I), selenium (Se), molybdenum (Mo), and chromium (Cr)], the energy metabolic indicators [triglyceride (TG), glucose (Glu), total cholesterol (CHO), nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), lactate (LA), and blood urea nitrogen (BUN)], and inflammatory indexes [bovine haptoglobin (BoHp), histamine (HIS), and immunoglobulin G (IgG)] were measured, respectively. Furthermore, the correlations of the measured indicators with the degrees of lameness were analyzed. The results showed that in the plasma of dairy cows with 2/3-5 points of lameness, for the mineral elements' levels, Ca, Cu, I, Se, and Fe significantly decreased, Cr significantly increased, and Mo showed a decreasing trend; for levels of the energy metabolism indicators, NEFA and BHBA significantly decreased, BUN and LA significantly increased, and Glu, CHO, and TG showed an increasing trend; for inflammation indexes, the concentrations of HIS, BoHp, and IgG all significantly increased; and further analysis indicated that the Mo, Fe, NEFA, BUN, BHBA, IgG, Ca, and Se had a significant correlation with the degrees of lameness. Resulting data revealed the changes of mineral elements, metabolism, and inflammation indexes in the plasma of dairy cows suffering from different degrees of lameness, which will provided basic knowledge for in-depth understanding of lameness in dairy cows.