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Two pairs of salicylaldehyde derivative enantiomers, euroticins A and B (1 and 2), were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. Compound 1 possesses a highly constructed 6/6/6/5/7 pentacyclic structure featuring an unprecedented 2,11-dioxatricyclo[5.3.1.04,8]undecane core. Compound 2 represents the first example of 6/6/6/6 tetracyclic salicylaldehyde derivative. Their structures were established by spectroscopic analyses, X-ray diffraction, and electronic circular dichroism (ECD) and 13C NMR calculations. Compounds (+)-2 and (-)-2 exhibited remarkable antioxidative activities.

Aim This study aimed to investigate the effect of high glucose (HG) level on the proliferation, migration and invasion of trophoblasts and determine the role of placental growth factor (PLGF) in the process. Methods HTR8-S/Vneo was treated with different concentrations of d-glucose (0, 10, 15, 20, 25 and 30 μM) at different times (0, 6, 12 and 24 h). qRT-PCR and Western blot analyses were used to measure PLGF expression. The protein level of PLGF was measured by immunofluorescence. Cell proliferation was assessed with CCK-8 analysis. Wound healing and transwell assays were used to evaluate cell migration and invasion. Intercellular ROS was detected with DCFH-DA. Results After d-glucose treatment, the viability decreased in 25 and 30 μM groups. The HG group (25 μM) showed inhibited cell migration and invasion ability. The mRNA and protein levels of PLGF decreased under HG condition. Elevated ROS production was also detected in the HG group. Knocked-down PLGF expression enhanced increased ROS production and decreased cell migration and invasion, which reverted to the original levels after PLGF was overexpressed. Conclusion High glucose treatment inhibited HTR8-S/Vneo viability, migration and invasion by downregulating PLGF expression.

Nuclear protein 1 (NUPR1) is a stress-related small molecule and plays important roles in various tumors, including multiple myeloma (MM). Autophagy is essential for maintaining cellular homoeostasis in response to stress and, together with apoptosis, determines cell fate. Previous studies indicate that NUPR1 is involved in cancer progression of MM, but the underlying mechanisms have not been elucidated. In this study, we confirmed that NUPR1 and basal autophagy markers were highly expressed in the bone marrow of MM patients. The overexpression of NUPR1 was correlated with staging (both by Revised International Staging System [RISS] and Durie-Salmon [D-S] Staging System), levels of hemoglobin and calcium, and bone marrow plasma cell ratio in the MM patients. NUPR1 silencing reduced autophagy activities and induced apoptosis in U266 and RPMI 8226. We further observed a decrease in NUPR1 silencing-induced apoptosis in the presence of rapamycin, while an increase in apoptosis after chloroquine and 3-methyladenine treatment. Analysis of the mechanism indicated that PI3K/AKT/mTOR pathway was involved in autophagy-mediated apoptosis upon NUPR1 knockdown. In summary, our results demonstrate that NUPR1 silencing suppresses autophagy activities and induces autophagy-mediated apoptosis in MM cells through the PI3K/AKT/mTOR pathway, which exhibits potential as a treatment strategy for MM.

Steam generator water level control incorporates the system that controls the speed of the main water feed pump and the one that controls the degree to which the main water feed valve is open. Although these two control systems are set independently, they have a reciprocal influence. A key problem is that, in the actuator for the regulation of the two systems, the regulated variables tend to oscillate with a relatively large amplitude even under stable conditions. In this paper, a pervasive regulating resonance phenomenon is inspected and analyzed by means of simulating the real working conditions. And using a mathematical model of the main water feed flow, it reveals that the two factors which directly cause the regulation resonance phenomenon are the frequency characteristics of the control system and the phase difference. On the basis of this, three potential optimization schemes have been proposed: the optimization of the regulation parameters; changing the phase difference; and setting a regulation dead-band which can improve the stability of the control system.

DC–DC converter systems have drawn extensive research attentions and shown upward tendencies for industrial and military applications. In this article, a novel digital fast terminal sliding mode control (FTSMC) approach is investigated for dc–dc buck converters with mismatched disturbances. Specifically, the approximated discrete-time model of the converters with multiple disturbances is first obtained and analyzed based on the Euler's discretization method. Then, by adopting the delayed estimation technique, it is easy to obtain the accurate estimations of the lumped disturbances. Integrating disturbance compensations into the modified digital fast terminal sliding mode surface, the proposed controller is finally constructed on the basis of equivalent control method and the performance analysis is presented. Both simulation and experimental comparisons are made for the proposed digital FTSMC approach and the existing discretized linear sliding mode controllers to validate the effectiveness and feasibility of the presented controller. The proposed FTSMC approach is characterized by higher voltage tracking accuracy and better dynamic properties in different operating conditions.

A new furanone analog, (E)-2-(8,9-dihydroxy-6,8-dimethyldec-4-en-2-yl)-met-hylfuran-3(2H)-one (1), together with six known compounds, including two diterpenoids (2 and 3), one butyrolactone (4) and three isocoumarins (5–7), were isolated from a deep-sea fungus, Purpureocillium sp. SCSIO 06693. Among them, compound 1 existed as two tautomeric forms (1a and 1b) differing in configuration of the furan ring. The chemical structures were elucidated by the basis of spectroscopic evidences, including HRESIMS, NMR and optical rotation. Isolated compounds were evaluated for their cytotoxic, antiviral, antibacterial, antioxidant, acetyl cholinesterase (AChE) and pancreatic lipase (PL) enzyme inhibitory activities. Biological evaluation results revealed that compound 4 showed modest antioxidant activity against DPPH with IC50 value of 72.03 μM. In addition, compounds 1–4 exhibited PL enzyme inhibitory activities.

Nickel (Ni) is a widely utilized heavy metal that can cause environmental pollution and health hazards. Its safety has attracted the attention of both the environmental ecology and public health fields. While the central nervous system (CNS) is one of the main targets of Ni, its neurotoxicity and the underlying mechanisms remain unclear. Here, by taking advantage of the zebrafish model for live imaging, genetic analysis and neurobehavioral studies, we reveal that the neurotoxic effects induced by exposure to environmentally relevant levels of Ni are closely related to ferroptosis, a newly-described form of iron-mediated cell death. In vivo two-photon imaging, neurobehavioral analysis and transcriptome sequencing consistently demonstrate that early neurodevelopment, neuroimmune function and vasculogenesis in zebrafish larvae are significantly affected by environmental Ni exposure. Importantly, exposure to various concentrations of Ni activates the ferroptosis pathway, as demonstrated by physiological/biochemical tests, as well as the expression of ferroptosis markers. Furthermore, pharmacological intervention of ferroptosis via deferoxamine (DFO), a classical iron chelating agent, strongly implicates iron dyshomeostasis and ferroptosis in these Ni-induced neurotoxic effects. Thus, this study elucidates the cellular and molecular mechanisms underlying Ni neurotoxicity, with implications for our understanding of the physiologically damaging effects of other environmental heavy metal pollutants.

An innovative design of microbial electrolytic reactor (MER) coupled with Ipomoea aquaticaForsk. plant microbial fuel cell (IAF-PMFC) was developed for azo dye wastewater treatment and electricity generation. This study aims to assess the sequential degradation of azo dye and the feasibility of energy self-sufficiency in the MER/IAF-PMFC system. The decomposition of azo dye into aromatic amines and dye decolorization occurred in the MER at high hydraulic loading of 0.28 m

Chemical investigation on the deep-sea-derived fungus Chaetomium globosum led to the isolation of nine compounds. By extensive analyses of the1D and 2D NMR as well as HRESIMS spectra, their structures were elucidated as xylariol A ( 1 ), 1,3-dihydro-4,5,6-trihydroxy-7-methyl-isobenzofuran ( 2 ), epicoccone B ( 3 ) epicoccolide B ( 4 ), chaetoglobosin G ( 5 ), chaetoglobosin Fex ( 6 ), cochliodone A ( 7 ), cochliodone B ( 8 ), and chaetoviridin A ( 9 ), assorting as four phenolics ( 1 - 4 ), two cytochalosans ( 5 - 6 ), and three azaplilones ( 7 - 9 ). Compounds 1 - 3 were firstly reported from C. globosum . Under the concentrations of 20 μg/mL, 1 , 2 , and 3 exhibited potent in vitro anti-HIV activity with the inhibition rates of 70%, 75%, and 88%, respectively.

For cochlear implant training and robotic cochlear implant experiments, the design method of scalable scala tympani model was proposed. The mathematical model of the cochlea was used as the central curve of scala tympani channel. Referring to the clinical anatomy data, the contour of the scala tympani cross-section was approximated as an ellipse. The profile was placed along the central curve, and the angle was adjusted to determine the position and orientation of the profile in three dimensions such that the central curve passes through its center. The data was imported into Matlab to generate a three-dimensional mathematical model of scala tympani, which can be expanded by setting different scale factors. The virtual scala tympani model was generated in SolidWorks, and the 2:1 fully transparent scala tympani model were fabricated by 3D printing to replace the specimen for experiment.

Dry eye disease (DED) is a widespread and frequently reported multifactorial ocular disease that not only causes ocular discomfort but also damages the cornea and conjunctiva. At present, topical administration is the most common treatment modality for DED. Due to the existence of multiple biological barriers, instilled drugs generally exhibit short action times and poor penetration on the ocular surface. To resolve these issues, several advanced drug delivery systems have been proposed. This review discusses new dosage forms of drugs for the treatment of DED in terms of their characteristics and advantages. Innovative formulations that are currently available in the market and under clinical investigation are elaborated. Meanwhile, their deficiencies are discussed. It is envisioned that the flourishing of advanced drug delivery systems will lead to improved management of DED in the near future.

The performance of attitude stabilization control algorithms for rigid spacecraft can be limited by disturbances. In this paper, the global finite-time attitude stabilization problem with disturbances is investigated and handled by constructing a second-order sliding mode controller. Firstly, a virtual controller based on set stabilization idea is constructed to globally finite-time stabilize the system. Then, a relay polynomial second-order sliding mode controller is constructed to guarantee that the tracking error towards the virtual controller will converge to zero in finite-time. Finite-time Lyapunov theory is applied to support the proof and stability analysis. The global finite-time stability holds even with bounded disturbances. The effectiveness and feasibility of the controller are illustrated by the numerical simulations.

Fluorometholone (FMT) is a frequently prescribed drug for the alleviation of dry eye. However, due to low aqueous solubility, it has been routinely used as an ophthalmic suspension, which is characterized by low bioavailability, inconvenience of administration, and difficulty in delivering accurate dose. Furthermore, the opaque appearance of the ophthalmic suspension is not desirable for optical purpose. In the present study, a transparent FMT nanoformulation (FMT-CD NPs) was fabricated by the cyclodextrin (CD) nanoparticle technology without organic solvents. It was demonstrated that FMT was encapsulated in an amorphous form, which was associated with increased release rate and enhanced corneal penetration efficiency. The biocompatibility of FMT-CD NPs was confirmed by the Live/Dead assay, CCK-8 assay and the wound healing assay. Most importantly, FMT-CD NPs alleviated dry eye signs more efficiently than the commercial eye drop, with one-fifth the dosage of FMT in the latter. Collectively, our study provides a promising FMT formulation for improved management of dry eye while reducing drug related side effects.

BACKGROUND Alzheimer's disease (AD) is clinically characterized as a progressive cognitive impairment and behavioral disorder. Pathological hallmarks of AD include extracellular senile plaques (SPs), intracellular neurofibrillary tangles (NFTs) and massive neuronal loss. Although the exact cause of AD is not well understood, a mounting body of evidence has demonstrated that the pathogenesis of AD is associated with oxidative stress, neu-roinflammation, and amyloid beta (Aβ) induced neural apoptosis. Moreover, overexpression of β-secretase 1 (BACE1), Aβ, mammalian target of rapamycin (mTOR), and Tau proteins are closely related to cognitive symptoms in AD. Studies have demonstrated that artemether, an antimalarial drug with acceptable side effects, possesses protective effects against neuroinflammation and oxidative stress. Importantly, artemether can easily penetrate the blood brain barrier, thereby representing an ideal drug candidate for AD treatment. METHODS The effect of artemether on memory protection and the associated molecular mechanisms were investigated in an Aβ25-35 induced cognitive impairments rat model. RESULTS Results of the in vivo study showed that oral administration of artemether significantly attenuated Aβ25-35-induced cognitive impairment in rats. Results of the in vitro study revealed that artemether significantly downregulated the endogenous expression of Aβ, BACE1, mTOR, and Tau proteins in N2a cells. CONCLUSIONS The beneficial effect of artemether against Aβ 25-35-induced cognitive impairments was attributable to the downregulation of the expression of Aβ, BACE1, mTOR, and Tau proteins, suggesting the potential of artemether as an effective, neuronal protective, and multi-targeted drug candidate for AD treatment.

Diabetic cardiomyopathy (DbCM) is a prevalent disease, characterized by contractile dysfunction and left ventricular hypertrophy. Patients with DbCM have high morbidity and mortality worldwide. Recent studies have identified that pyroptosis, a kind of cell death, could be induced by hyperglycemia involved in the formation of DbCM. This review summarizes the regulatory mechanisms of pyroptosis in DbCM, including NOD-like receptor3, AIM2 inflammasome, long non-coding RNAs, microRNAs, circular RNA, autophagy, and some drugs.

To enlarge the chemical diversity of Eurotium sp. SCSIO F452, a talented marine-derived fungus, we further investigated its chemical constituents from a large-scale fermentation with modified culture. Four pairs of new salicylaldehyde derivative enantiomers, euroticins F-I (1–4), as well as a known one eurotirumin (5) were isolated and characterized. Compound 1 features an unprecedented constructed 6/6/6/5 tetracyclic structures, while 2 and 3 represent two new types of 6/6/5 scaffolds. Their structures were established by comprehensive spectroscopic analyses, X-ray diffraction, 13C NMR, and electronic circular dichroism calculations. Selected compounds showed significant inhibitory activity against α-glucosidase and moderate cytotoxic activities against SF-268, MCF-7, HepG2, and A549 cell lines.

A new indole diketopiperazine alkaloid, named penilline D (

Hepatocellular carcinoma (HCC) ranks third in the cause of death due to cancer. Circular RNA circSEC24 Homolog A (circSEC24A) has been uncovered to be upregulated in liver cancer. However, the function of circSEC24A in HCC is indistinct. We analyzed the microarray datasets GSE78520 and GSE94508 to search for differentially expressed circRNAs associated with HCC. Expression of circSEC24A, microRNA (miR)-455-3p, and protein phosphatase, Mg2+/Mn2+ dependent 1F (PPM1F) mRNA was detected by quantitative real-time polymerase chain reaction (RT-qPCR). Loss-of-function experiments were conducted to validate the biological function of circSEC24A in HCC cells in vitro and in vivo. Protein levels were evaluated by western blotting and immunohistochemistry (IHC). The relationship between circSEC24A or PPM1F and miR-455-3p was verified by a dual-luciferase reporter and/or RNA immunoprecipitation (RIP) assays. circSEC24A was overexpressed in HCC. circSEC24A silencing decreased xenograft tumor growth in vivo and repressed proliferation, metastasis, invasion, epithelial-to-mesenchymal transition (EMT), induced cell cycle arrest, and apoptosis of HCC cells in vitro. circSEC24A acted as a molecular sponge to sequester miR-455-3p, resulting in elevating the expression of PPM1F. miR-455-3p inhibitor reversed the suppressive impact of circSEC24A silencing on malignant behaviors of HCC cells. PPM1F overexpression offsets the inhibitory effect of miR-455-3p mimic on malignant behaviors of HCC cells. circSEC24A sponged miR-455-3p to elevate the PPM1F expression, resulting in accelerating malignant behaviors of HCC cells. The study provided a potential therapeutic target for patients with HCC.

Cadmium (Cd) is a worldwide environmental pollutant that postures serious threats to humans and ecosystems. Over the years, its adverse effects on the central nervous system (CNS) have been concerned, whereas the underlying cellular/molecular mechanisms remain unclear. In this study, taking advantages of zebrafish model in high-throughput imaging and behavioral tests, we have explored the potential developmental neurotoxicity of Cd at environmentally relevant levels, from the perspectives of neurobehavior and neuroimaging. Briefly, Cd2+ exposure resulted in a general impairment of zebrafish early development. Zebrafish neurobehavioral patterns including locomotion and reactivity to environmental signals were significantly perturbed upon Cd2+ exposure. Importantly, a combination of in vivo two-photon neuroimaging, flow cytometry and gene expression analyses revealed notable neurodevelopmental disorders as well as neuroimmune responses induced by Cd2+ exposure. Both cell-cycle arrest and apoptosis contributed jointly to a significant decrease of neuronal density in zebrafish larvae exposed to Cd2+. The dramatic morphological alterations of microglia from multi-branched to amoeboid, the microgliosis, as well as the modulation of gene expression profiles demonstrated a strong activation of microglia and neuroinflammation triggered by environmental levels of Cd2+. Together, our study points to the developmental toxicity of Cd in inducing CNS impairment and neuroinflammation thereby providing visualized etiological evidence of this heavy metal induced neurodevelopmental disorders. It's tempting to speculate that this research model might represent a promising tool not only for understanding the molecular mechanisms of Cd-induced neurotoxicity, but also for developing pharmacotherapies to mitigate the neurological damage resulting from exposure to Cd, and other neurotoxicants.

Advanced oxidation processes (AOPs) are important technologies for aqueous organics removal. Despite organic pollutants can be degraded via AOPs generally, high mineralization of them is hard to achieve. Herein, we synthesized a manganese oxide nanomaterial (H2-OMS-2) with abundant Brønsted-acid sites via ion-exchange of cryptomelane-type MnO

This paper proposes, a method for the physical modeling of the perimodiolar electrode, particularly for the process of recovering its preset shape with the guide wire drawn out, based on the composite spring-mass model by employing the virtual-volumetric spring inspired from the traditional spring-mass model. Simulation experiments of modeling and virtual insertion of perimodiolar electrode were carried out. The results indicated that the mean and standard deviation of the difference between the local deformation angles of the simulated and measured sets of mass points, (1, 2, 3), (2, 3, 4), …, (13, 14, 15), were 6.34° and 5.98°, respectively. Additionally, the physical model of the perimodiolar electrode can reflect the overall morphological changes of the real perimodiolar electrode.

Lead induced neurotoxicity has been extensively investigated. However, the potential connections between early-life lead exposure and the frequently observed aberrant neurobehavior in juveniles and adults remain unclear. In this study, zebrafish model was used to explore the immediate and long-term effects of early-life exposure to environmental levels of lead on the central nervous system, and the cellular and molecular mechanisms underlying the consequent abnormal neurobehavior. Lead exposed zebrafish larvae exhibited neurologic damage and defective neurobehavior. Consistent with clinical studies, despite being raised in lead-free conditions, the juvenile and adult fish experienced lead exposure earlier, presented ADHD-like symptoms, and the adult fish exhibited remarkably affected vitality and shoaling behavior. Their anxiety levels were elevated, whereas their social interaction, as well as learning and memory were strongly depressed. The expression profiles of key genes involved in neurodevelopment and neurotransmitter systems were significantly modulated, in similar patterns as in the larval stage. Notably, the density of neurons was decreased and varicosities in neuronal axons were frequently observed in the lead-exposed groups. It's tempting to speculate that the disruption of early neurodevelopment as well as the prolonged modulation of neuromorphic and neurotransmitter systems contribute to the lead-induced neurobehavioral disorders observed in juveniles and adulthood.

The vascular endothelium, which plays an essential role in maintaining the normal shape and function of blood vessels, is a natural barrier between the circulating blood and the vascular wall tissue. The endothelial damage can cause vascular lesions, such as atherosclerosis and restenosis. After the vascular intima injury, the body starts the endothelial repair (re-endothelialization) to inhibit the neointimal hyperplasia. Endothelial progenitor cell is the precursor of endothelial cells and plays an important role in the vascular re-endothelialization. However, re-endothelialization is inevitably affected in vivo and in vitro by factors, which can be divided into two types, namely, promotion and inhibition, and act on different links of the vascular re-endothelialization. This article reviews these factors and related mechanisms.

The coolant fill rate setting of CPR1000 unit reactor core has train A/B of redundancy measuring channels, whose function is to monitor the water inventory of reactor core under the working conditions of water loss and other accidents to ensure the safety of reactor core. In order to confirm the reliability of train A/B of redundancy measuring channels, a technical solution for the cross comparison of fill rate during the reactor refueling cycle is proposed to validate the consistency of train A/B of redundancy measuring and computing channels. Through the cross validation model of fill rate of reactor core coolant monitoring system, the sensitivity analysis on such input variables as relative pressure of primary coolant circuit, temperature of reactor core, differential pressure of reactor core, absolute pressure of containment, etc. shall be conducted. The sensitivity analysis model adopts the GUM method for the law of propagation of uncertainty, through which the proportion of uncertainty components of various input variables can be obtained. Moreover, the aided analysis based on the engineering statistic data from the nuclear power units of various bases shall be conducted to determine the sensitivity variables of cross validation of fill rate. Based on the combination of variable sensitivity analysis and process variables influence analysis with the switching process of the unit uplink status and the objective law of system change, the optimal window and system condition setting for the redundancy cross validation is proposed, including such factors and statuses as system pressure, temperature, running condition of primary pump, etc. Such solution has been applied to engineering sites, and has achieved good effects which can prove its feasibility and effectiveness.

In this brief, a harmonic disturbance observer (HDOB) based control approach is proposed for the robust voltage regulation design of a dc–ac inverter system. In distributed generation systems, wide range of load variations and effects of nonlinear loads result in significant degradations of control performance. Moreover, the loads, as the mismatched disturbances, impose adverse influences on the inverter system via a channel different from the control input. Toward that end, an HDOB is proposed to estimate the periodic load disturbances. By constructing new disturbance compensation gains, the effects of the mismatched periodic disturbances are removed from the output voltage channel. Rigorous stability analysis for the closed-loop system is presented. Experimental results are explored to illustrate the feasibility and capacity of the proposed control scheme.

(±)-Eurotone A [(±)- 1 ], a pair of new enantiomeric polyketide dimers, as well as six known biogenetically related polyketides ( 2 – 7 ) were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. Their structures were determined by comprehensive spectroscopic methods, X-ray diffraction and quantum chemical calculations. Compound 1 represented the first pair of spirodihydrobenzanthracene enantiomers isolated from marine fungi with their absolute configurations assigned. A plausible biosynthetic pathway involving a key acid-mediated dimerization was proposed for 1 . The antioxidative activities of the new enantiomers were evaluated.

In order to evaluate the performance of the slip critical bolted connection of HSS members, 30 specimens fabricated from high strength steel (HSS) (Q550, Q690 and Q890), are tested to investigate the slip factors of shot-blasted surface and rusted surface after blasting. For comparison, a group of specimens fabricated from mild steel Q345 are tested as well. In order to investigate the effect of the steel strength grade on slip factor, the values of hardness, roughness and capacity of plastic deformation of steels with different strength grades are also tested and analyzed. Based on experimental results and friction theory, it is found that with the same blasting treatment, the surface roughness tends to decrease with the increase of steel hardness, which induces the decreasing of the slip factor. Based on the friction mechanism, the slip factor is not only decided by surface roughness, but also can be affected by the capacity of plastic deformation of the contacting materials. With the increasing of plastic deformation capacity of the steel, the slip factor tends to be higher. According to the test results, the suggested slip factor of HSS specimens with blasted surfaces is 0.40. Moreover, for the specimens with rusted surface after blasting, there may be an increment in the slip factor owing to the increased surface roughness by rusting. However, the positive influence of rusting on the slip factor is not recommended to be considered in the connection design due to its instability. Therefore, the recommended slip factor of the specimen with rusted surface after blasting takes the value of 0.40 as well.

In this study, overcurrent protection technique is investigated for the voltage regulation problem of the DC–DC buck converter system with time-varying disturbances and uncertainties. Normally, fast dynamics during the start-up phase generates large transient current. The overlarge transient current may lead to risks of hardware damage. By selecting conservative control parameters, the current constrained performance can be realised. However, the transient performance and disturbance rejection ability are sacrificed. It is of significant importance to design a controller which keeps a good balance between dynamic performance and overcurrent protection. Moreover, the control accuracy is inevitable affected by the time-varying disturbances effects, including load variations, input voltage fluctuations and circuit parameter perturbations. In this paper, the control design is divided into two parts. Firstly, by inserting a dynamic penalty term into the state feedback controller, a baseline current-constrained scheme is developed. Rigorous stability analysis and current constraint performance are given under the presented baseline controller. Secondly, taking the time-varying disturbances into account, a novel GPI observer-based composite current-constrained controller can be developed by combining disturbance estimations and the baseline controller. Experimental results are provide to demonstrate the effectiveness of the presented control strategy.

A new butenolide derivative (±)-asperteretal F (1) and related congener (2) recently reported containing an unusual 2-benzyl-3-phenyl substituted lactone core, together with five known compounds (3–7) were isolated and characterized from the fungus Aspergillus terreus. SCSIO FZQ028 derived from a deep-sea sediment of South China Sea. Their chemical structures were established on the basis of 1D- and 2D-NMR spectroscopic data, and HR-ESI-MS analysis. Additionally, all the compounds were evaluated for the antioxidative activities against DPPH, cytotoxic activities against two tumor cell lines (SF-268 and HepG-2), and antimicrobial activities. Compounds 2-4, and 7 showed significant activities against DPPH with IC50 ranging from 5.89 to 10.07 μg/mL. Compounds 2 and 4 showed moderate antimicrobial activities against all four tested bacteria.

A new strategy was proposed for the electrochemical fabrication of manganese dioxide (MnO2) coatings on titanium (Ti) fibers. In order to achieve stable MnO2 coatings, a Ti wire was initially anodized in methanol/water containing fluoride ions for the in situ growth of nano/submicro-scale titania (TiO2) pyramids. Thereafter, silica nanoparticles (SiO2NPs) were electrophoretically deposited on the TiO2 coatings. Finally, the nanoparticle-like MnO2 coating was homogeneously formed on the Ti@TiO2@SiO2NPs fiber support in neutral electrolytic solution by cyclic voltammetry using polypyrrole as an organic binder. The resulting fiber showed good extraction selectivity and efficient extraction capability for aromatic compounds with large delocalized π-systems. For this purpose, this fiber was used for the selective enrichment of the studied polycyclic aromatic hydrocarbons (PAHs) coupled to high-performance liquid chromatography with ultraviolet detection. The linear calibration curves were obtained in the concentration range of 0.01–500 μg L−1 with correlation coefficients higher than 0.999 in all instances. The relative standard deviations (RSDs) for single fiber repeatability varied from 4.7% to 5.5% for intra-day and inter-day measurements (n = 5), and RSDs for the fiber-to-fiber reproducibility varied from 5.8% to 6.7% (n = 5). The developed method was successfully applied to the selective enrichment and sensitive determination of target PAHs in river water, rain water and wastewater samples with relative recoveries from 93.0% to 106%. Furthermore, the fabricated fiber was stable enough to perform the whole analytical sequence in practical applications.

Laminar natural convection in a vertical annulus with inner wall covered by a porous layer is numerically studied in this paper by using a multiple-relaxation-time lattice Boltzmann (MRT LB) model for the axisymmetric thermal flow in porous media at the representative element volume (REV) scale. The effects of the Rayleigh number, Darcy number, thermal diffusivity ratio and thickness of the porous layer on the overall heat transfer rate are investigated. It is found that wrapping with a porous layer can serve as a useful tool for heat transfer augmentation or reduction, which is strongly depending on the physical parameters, especially the Darcy number and thermal diffusivity ratio.

In this study, diamond crystals were synthesized via the temperature gradient method at 5.6 GPa and 1230–1245 °C by adding a Mn3P2 dopant and FeNi catalyst. Experimental results showed that Mn3P2 shifted the V-shaped growth region to the upper right by influencing the catalytic properties. The scanning electron microscopy (SEM) photographs of the diamonds synthesized at 1245 °C revealed that there were many dendritic structures in the (100) surfaces. The diamond crystal quality could be improved when the added Mn3P2 was less than 6 wt% at 1245 °C, but it would be seriously damaged when the diamond was heavily doped with Mn3P2. Pits and uneven layered structures appeared on the diamond surfaces when the additive was included at 12 wt% at 1245 °C. The Fourier transform infrared spectroscopy (FTIR) results revealed that the Mn3P2 additive increases the N content of the crystal and that N is present in the diamond crystal in the form of a “C” center. It is worth noting that phosphorus could be doped into diamond crystals by using the Mn3P2 additive and that the other impurities in diamonds were mostly C–N and C–O forms, as confirmed by X-ray photoelectron spectroscopy (XPS). The phosphorus in the sample crystals mainly formed C–P bonds with carbon, while a smaller amount of phosphorus formed P–O bonds with oxygen. The test results of the electrical properties as assessed by the van der Pauw method for the diamond crystals with Mn3P2 doped at 1245 °C revealed a resistivity of 0.516 × 106–9.729 × 106 Ω cm and a negative Hall coefficient, indicative of an n-type semiconductor.

The output voltage tracking problem with overcurrent protection for a pulse width modulation-based dc–dc buck converter is investigated in this brief. On the one hand, large transient current during the start-up phase is required for fast dynamics. On the other hand, overlarge transient current may lead to a risk of hardware damage. Conventionally, this problem is solved by choosing conservative control parameters, while the dynamic performance is sacrificed to a certain extent. Besides, the load uncertainty is inevitable in practical applications. Hence, a control design that keeps a good balance between dynamic performance, overcurrent protection, and robustness is desired. To this end, a novel and simple current-constrained controller is constructed. Both dynamic performance and current constraint are taken into account. The low complexity of the proposed current-constrained controller yields a higher reliability of dc–dc buck converter control system, and reduces cost of hardware. Moreover, it shows a nice property of robustness against load uncertainty. Control action is penalized by adjusting controller gains automatically when inductor current tends to the barrier bound. Rigorous stability analysis is given under the presented controller. Comparative simulation and experimental results between the proposed control scheme and the classic proportion–integration–differentiation control scheme on the buck converter system are illustrated to verify the feasibility and effectiveness of the proposed control scheme.

In an effort to turn waste into wealth, Reactive Red 2 (RR2), a common and refractory organic pollutant in industrial wastewater, has been employed for the first time as a precursor to synthesize carbon nanodots (CNDs) by a facile, green and low-cost route, without utilization of any strong acids or other oxidizers. The detailed characterizations have confirmed that the synthesized CNDs exhibit good water dispersibility, with a mean particle size of 2.43 nm and thickness of 1–3 layers. Importantly, the excellent fluorescence properties and much reduced biotoxicity of the CNDs confer its potential applications in further biological imaging, which has been successfully verified in both in vitro (cell culture) and in vivo (zebrafish) model systems. Thus, it is demonstrated that the synthesized CNDs exhibit nice biocompatibility and fluorescence properties for bioimaging. This work not only provides a novel economical and environmentally friendly approach in recycling a chemical pollutant, but also greatly promotes the potential application of CNDs in biological imaging., The pollutant reactive red 2 was employed to synthesize fluorescent carbon nanodots allowing biological imaging in vitro and in vivo.

Through profiling learners’ music usage in everyday learning settings and depicting their learning experience when studying with a music app powered by a large-scale and real-world music library, this study revealed preliminary observations on how background music impacts learning under varying task load, and manifested intriguing patterns of learners’ music usage and music preferences in various task load conditions. Specifically, we piloted a three-day field experiment in students’ everyday learning environment. During the experiment, participants performed learning tasks with music in the background and completed a set of online surveys before and after each learning session. Our results suggested that learners’ self-selected, real-life background music could enhance their learning effectiveness, while the beneficial effect of background music was more apparent when the learning task was less mentally or temporally demanding. Towards a closer look at the characteristics of preferable music pieces under various task load conditions, our findings showed that music preferred by participants under high versus low temporal demand differs in a number of characteristics, including speechiness, acousticness, danceability, and energy. This study further reveals the effects of background music on learning under varying task load levels and provides implications for context-aware background music selection when designing musically enriched learning environments.

Northeast China—located near the northern limit of the influence by the East Asian summer monsoon—receives most moisture through the westerly airflow, but variations in moisture contributions from the Yellow Sea in the western Pacific Ocean determine its hydroclimate during summer monsoon season. The proportion of moisture from the Yellow Sea is strongly modulated by the location and intensity of the Western Pacific Subtropical High (WPSH). However, it is still unclear how sensitive regional hydroclimate to WPSH-modulated change in moisture sources and its impact on peatland carbon accumulation. Here, we used macrofossil data and paired δ13C and δ18O isotope analysis of Sphagnum moss cellulose from a well-dated bog from a steep mountain slope in the Greater Khingan Mountains (~47˚N) to reconstruct peatland moisture changes and elucidate past shifts in moisture sources. δ13C values reflect peatland surface moisture, as dry conditions with less water film effects would increase isotopic discrimination against 13C and result in lower δ13C values. Our results from a 250-year peat record show a decrease of ~3‰ in δ13C from -25 to -28‰—with corresponding increase in dry-adapted moss Polytrichum—suggesting a drying trend since about 1980 AD. Also, the down-core δ18O and δ13C data show a positive correlation (r = 0.65, p < 0.001), in contrast with evaporative enrichment of δ18O being the dominant effect. We argue that δ18O values reflect the input of moisture derived from the Yellow Sea—that has higher δ18O values than that from the westerlies—as modulated by the WPSH. When the WPSH extends westward, it blocks moisture transport from the Yellow Sea to North China, causing low δ18O values in summer precipitation, dry conditions, and negative shifts in δ13C, and vice versa. Furthermore, carbon accumulation rates show a major decrease after the 1980s—despite that more recent peat tends to have higher apparent accumulation rates—suggesting a sensitive response of this steep-slope mountain peatland to shift in regional hydroclimate in monsoon-margin region of Northeast China.