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Six arsenic(III)-capped 12-tungsto-2-arsenates(III) of the type [M2(AsIIIW6O25)2(AsIIIOH)x]n- (M = CrIII, 1; FeIII, 2; ScIII, 3; InIII, 4; TiIV, 5; MnII, 6) have been synthesized in aqueous medium by direct reaction of the elements using a one-pot strategy and structurally characterized by FT-IR spectroscopy, single-crystal XRD, and elemental analysis. Polyanions 1-6 are comprised of two octahedrally coordinated guest metal ions M sandwiched between two {AsW6} units, resulting in a structure with C2h point-group symmetry. Polyanions 1-5 contain tri- and tetravalent metal ion guests M (M = CrIII, FeIII, ScIII, InIII, and TiIV, respectively), and they have one {AsIIIOH} group grafted on each {AsW6} unit, whereas the divalent MnII-containing derivative 6 has two such {AsIIIOH} groups grafted on each {AsW6} unit. Magnetic studies on polyanions 3-5 over the temperature range 1.8-295 K and magnetic fields of 0-7 T confirmed that they are diamagnetic. On the other hand, polyanions 1, 2, and 6 are strongly magnetic and follow the Curie-Weiss law above 30 K. The susceptibility plots of 1 and 6 exhibit broad peaks suggesting short-range antiferromagnetic ordering, while the very weak antiferromagnetic ordering of 2 is overshadowed by traces of a paramagnetic impurity. The magnetization data of 1, 2, and 6 at 1.8 K over 0-7 T were analyzed by using the Heisenberg exchange procedure. Small (negative) values of the obtained J values help in understanding the absence of long-range antiferromagnetic ordering.

We study a fairness-based model for 2-facility location games on the real line where the social objective is to minimize the maximum envy over all agents. All the agents seek to minimize their personal costs, and the envy between any two of them is the difference in their personal costs. We consider two cases of personal costs, called min-dist cost and sum-dist cost. We are interested in pursuing strategyproof mechanisms for 2-facility location games in both cases. For the min-dist personal cost, we first show that a lower bound of the additive approximation for any deterministic strategyproof mechanism is 1/4, then devise a deterministic group strategyproof mechanism with additive approximation of 1/2 and two randomized strategyproof mechanisms with additive approximation of 1/4. For the sum-dist personal cost, we devise a group strategyproof deterministic mechanism which is also optimal.

Direct infusion (DI) has an extraordinary high-throughput advantage. Pseudo-targeted metabolomics (PTM) has been demonstrated integrating the merits of both nontargeted and targeted metabolomics. Herein, we attempted to implant DI into the PTM concept to configure a new strategy allowing shotgun PTM. First, a versatile MS/MSALL program was applied to acquire MS1 and MS2 spectra. Second, online energy-resolved MS (online ER-MS) was conducted to obtain breakdown graph as well as optimal collision energy (OCE) for each ion transition paired by precursor ion and the dominant product ion. Third, selected reaction monitoring (SRM) was responsible to output a quantitative dataset with a constant length. Moreover, breakdown graph also served as orthogonal structural evidence when matching MS2 spectra between DI-MS/MS and an in-house library to strengthen structural annotation confidence. To evaluate and illustrate the utility of the new strategy toward shotgun PTM of medicinal plants, in-depth chemome comparison was conducted within three Cistanche species, all of which are edible medicinal plants and playing essential roles for turning the deserts into the oases. A total of 185 variables participated in the quantitative measurement program. Each diagnostic ion pair was featured with an OCE. Significant species differences occurred, and echinacoside, acteoside, isoacteoside, 2'-acetyl-acteoside, tubuloside B, mannitol, sucrose, betaine, malate, as well as choline were found to be confirmative chemical markers offering primary contributions toward the species discrimination. After cross-validation with LC-MS/MS, DI-MS/MS fortified with the new strategy is an eligible tool for shotgun PTM, beyond Cistanche plants.

Advanced anti-counterfeiting materials have great research significance in the fields of economy, safety and human health. Compared with independent color mixed anti-counterfeiting materials, ultraviolet (UV) excitation wavelength-dependent discoloration, which can realize the change of the emission peak shape and color under different excitation wavelengths, is more attractive. In this work, the Sb-doped Cs2ZrCl6 vacancy-ordered double perovskite was designed and synthesized for anti-counterfeiting materials. Due to the singlet and triplet transitions of Sb3+ ions and self-trapping exciton (STE) emission of the Cs2ZrCl6 host, the material showed emission variability from blue to orange-yellow color. In addition, room temperature synthesis and excellent air and humidity stability further enhanced the potential of Sb-doped Cs2ZrCl6 for application.

A new series of sulphonamide derivatives bearing naphthalene moiety were synthesised and evaluated for their antiproliferative and tubulin polymerisation inhibitory activities. These new compounds were evaluated for their in vitro antiproliferative activity against MCF-7 and A549 by using CCK-8 method. Among all the tested compounds, compound 5c with naphthalen-1-yl moiety exhibited the most potent antiproliferative activity against MCF-7 and A549 cell line, with IC50 values of 0.51 ± 0.03 µM and 0.33 ± 0.01 µM, respectively. The results of tubulin polymerisation assay shown that 5c exhibited a significant ability to inhibit tubulin polymerisation with IC50 value of 2.8 μM. Consistent with its antitubulin activity, 5c can significantly arrest the cell cycle at G2/M phase and induce apoptosis in MCF-7 cancer cells. Molecular docking study indicated that compound 5c inhibited tubulin polymerisation through interacting at the colchicine-binding site of tubulin. Furthermore, 5c exhibited low cytotoxic activity on human normal cell line.

NaMnF3:Yb,Er and NaMnF3:Yb,Er@NaGdF4:xEu (x = 0, 0.3, 0.6, and 0.9) samples were synthesized by a simple hydrothermal method. The as-obtained NaMnF3:Yb,Er particles show a single red emission under the irradiation of infrared light (980 nm), due to the energy exchange transfer process between Mn2+ ions and Er3+ ions. Notably, further growth of NaGdF4:Eu on the basis of NaMnF3:Yb,Er enhanced the green up-conversion luminescence of Er3+ ions, which gradually shifted from red to green with the increase of the Gd3+ ion doping amount. In addition, NaMnF3:Yb,Er@NaGdF4:Eu exhibits red color under ultraviolet excitation (397 nm). These results provide a possible means for controlling the luminescence properties of the lanthanide doped up-conversion system. The luminescent film synthesized with NaMnF3:Yb,Er@NaGdF4:Eu can show different luminescent colors under different light irradiation (near infrared and ultraviolet), which indicates that they have potential applications in multi-mode anti-counterfeiting.

Mechanistic studies reveal that Pd-catalyzed C(sp3)–H arylation of thioethers with silver(I) additives takes place via C(sp3)–H activation, oxidative addition and reductive elimination, wherein all steps proceed via the heterodimeric Pd–Ag pathway. Besides, the active heterodimeric Pd–Ag species are detected by mass spectrometry via control experiments.

The development of advanced luminescent materials with simple synthesis and a high safety factor is still a great challenge for anti-counterfeiting applications. Herein, multi-mode emission NaYF4:Ln (Ln = Er/Tm, Yb/Er, Yb/Tm)/NaYF4:Ce,Mn composites were synthesized by employing a hydrothermal method. These materials show an excitation source-dependent color change, and could show red, green and blue up-conversion (UC) luminescence under the irradiation of a 980 nm laser and exhibit green and blue down-conversion (DC) luminescence at 254 nm and 365 nm, respectively. The energy transfer mechanism of the UC and DC luminescence of the samples was discussed in detail. Moreover, the composite materials were further fabricated into fluorescent anti-counterfeit inks, and various multi-mode fluorescent patterns were created by screen printing technology. This work provides a simple and promising material with outstanding fluorescence properties for security and anti-counterfeiting applications.

A novel series of 4-(4-methoxynaphthalen-1-yl)-5-arylpyrimidin-2-amines were designed, synthesized, and evaluated for their anticancer activities. Most of the synthesized compounds exhibited moderate to high antiproliferative activity in comparison to the standard drug cisplatin. Among them, 5i bearing ethoxy at the 4-position of the phenyl was found to be the most active on MCF-7 and HepG2 cancer cell lines, with IC50 values of 3.77 ± 0.36 and 3.83 ± 0.26 µM, respectively. Further mechanism study shown that 5i potently inhibited tubulin polymerization, induced cell cycle arrest at G2/M phase and cell apoptosis in MCF-7 cell line. Furthermore, molecular modeling study suggested that 5i probably binds to the colchicine site of tubulin.

Polaritons with a twist The ability to design and fabricate optical systems with tunable topological features makes them especially attractive for developing analogs of topological condensed matter systems, which by themselves tend to be fixed or limited in their tunability. Liu et al. now show that the combination of a two-dimensional material with a photonic crystal can be used to develop an analogous quantum spin Hall system. The strong coupling between the monolayer tungsten disulfide excitons with a nontrivial hexagonal photonic crystal gives rise to helical topological polaritons observed at up to 200 kelvin. The topological polaritons can be actively tuned by temperature and may further be manipulated with electric or magnetic fields, thereby providing a flexible platform with which to explore exotic topological phenomena and new phases of quantum matter. Science , this issue p. 600

Polyoxometalates (POMs) have emerged as potential anode materials for lithium-ion batteries (LIBs) owing to their ability to transfer multiple electrons. Although POM anode materials exhibit notable results in LIBs, their energy-storage mechanisms have not been well-investigated. Here, we utilize various in operando and ex situ techniques to verify the charge-storage mechanisms of a Keplerate-type POM Na2K23{[(MoVI)MoVI5O21(H2O)3(KSO4)]12 [(VIVO)30(H2O)20(SO4)0.5]}·ca200H2O ({Mo72V30}) anode in LIBs. The {Mo72V30} anode provides a high reversible capacity of up to ∼1300 mA h g-1 without capacity fading for up to 100 cycles. The lithium-ion storage mechanism was studied systematically through in operando synchrotron X-ray absorption near-edge structure, ex situ X-ray diffraction, ex situ extended X-ray absorption fine structure, ex situ transmission electron microscopy, in operando synchrotron transmission X-ray microscopy, and in operando Raman spectroscopy. Based on the abovementioned results, we propose that the open hollow-ball structure of the {Mo72V30} molecular cluster serves as an electron/ion sponge that can store a large number of lithium ions and electrons reversibly via multiple and reversible redox reactions (Mo6+ ↔ Mo1+ and V5+/V4+↔ V1+) with fast lithium diffusion kinetics (DLi+: 10-9-10-10 cm2 s-1). No obvious volumetric expansion of the microsized {Mo72V30} particle is observed during the lithiation/delithiation process, which leads to high cycling stability. This study provides comprehensive analytical methods for understanding the lithium-ion storage mechanism of such complicated POMs, which is important for further studies of POM electrodes in energy-storage applications.

Multi-walled carbon nanotubes (MWNTs) were prepared by pyrolysis of cheap natural gas over Ni/La2O3-MgO catalyst at 740 °C. The purified MWNTs were easily dispersed by ball milling method and aqueo...

Nitrogen pollution is a serious environmental issue in the Danjiangkou Reservoir region (DRR), the water source of the South-to-North Water Diversion Project of China. In this research, seasonal surveys and a bi-weekly time series survey were conducted in the Qihe River Basin, one of the most densely populated agricultural basins in the DRR. Hydrochemical compositions (NO3− and Cl−), dual isotopes (δD-H2O, δ18O-H2O, δ15N-NO3−, and δ18O-NO3−), and a Markov Chain Monte Carlo isotope mixing model were jointly applied to unravel the sources, migrations, and transformations of the nitrate (NO3−) in the basin. It was revealed that the mixing between different sources was the main process controlling the isotopic compositions of the riverine NO3− in the upper-middle reaches. In contrast, denitrification occurred in the lower reaches. For the first time, the sources of NO3− were quantified at a basin scale in the DRR. Overall, the river transported 484.2 tons/year of NO3-N to the reservoir, of which 32.6%, 36.4%, 28.0%, and 3.0% was from soil organic nitrogen, chemical fertilizer, residential sewage and atmospheric precipitation, respectively. The NO3-N fluxes of the different sources were regulated by the monsoon climate and anthropogenic activities. For example, high precipitation and intense fertilization resulted in severe nonpoint source pollution. Denitrification thrived in soils and reservoirs in wet seasons. Temperature could regulate the migration, nitrification and denitrification processes. Based on the results, we suggest that the management strategies dealing with nitrogen pollution issue in the DRR should follow the specific spatiotemporal characteristics of NO3− sources, migration and transformation mechanisms.

With the rapid industrialization, increasing of fossil fuel consumption and the environmental impact, it is an inevitable trend to develop clean energy and renewable energy. Hydrogen, for its renewable and pollution-free characteristics, has become an important potential energy carrier. Hydrogen is regarded as a promising alternative fuel for fossil fuels in the future. Therefore, it is very necessary to summarize the technological progress in the development of hydrogen energy and research the status and future challenges. Hydrogen production and storage technology are the key problems for hydrogen application. This study applied bibliometric analysis to review the research features and trends of hydrogen production and storage study. Results showed that in the 2004-2018 period, China, USA and Japan leading in these research fields, the research and development in the world have grown rapidly. However, the development of hydrogen energy still faces the challenge of high production cost and high storage requirements. Photocatalytic decomposition of water to hydrogen has attracted more and more research in hydrogen production research, and the development of new hydrogen storage materials has become a key theme in hydrogen storage research. This study provides a comprehensive review of hydrogen production and storage and identifies research progress on future research trend in these fields. It would be helpful for policy-making and technology development and provide suggestions on the development of a hydrogen economy.

In this study, a novel series of isoxazole-naphthalene derivatives as tubulin polymerization inhibitors were designed, synthesized and evaluated for their anti-proliferative activities against human breast cancer cell line MCF-7. Most of the synthesized compounds exhibited moderate to potent antiproliferative activity (IC50

Nanowires (NWs) and nanobelts (NBs) have been widely studied and fabricated into a variety of nanoscale devices such as light emitting diodes (LEDs), lasers and biosensors. These unique materials have attracted sustained attention due to their novel properties, ease of growth, and the ability to fabricate highly engineered devices. However, their widespread application remains hindered due to the difficulty in integrating multiple NWs or NBs together for more complex devices. Integration of multiple NWs and NBs together on the same chip can enable the coupling of different devices to help realize complex on-chip architectures such as photonic integrated circuits or nanoscale diagnostic tools, which currently require outcoupling using larger components. In this letter we report the coupling of on-chip NB LEDs and photodetectors using a single, precisely self-aligned, cadmium sulfide (CdS) NB fabricated on a silicon-on-insulator (SOI) substrate. Electroluminescence generated by the CdS NB is waveguided and measured across the self-aligned device and demonstrates an on/off ratio of 102–103. This work describes a new method for fabricating and integrating more complex nanoscale devices that can enable advances in areas such as on-chip optical computational components and nanoscale optical biodiagnostics.

Multi-walled carbon nanotubes (MWNTs) with high-yield were prepared by pyrolysis of mixture of natural gas (NG) and propylene (C3H6) over Fe-Ni/Al2O3-MgO catalyst. For C3H6/NG flow rate ratio rangi...

Background In recent years, nanomaterials have been increasingly developed and applied in the field of bone tissue engineering. However, there are few studies on the induction of bone regeneration by tantalum nanoparticles (Ta NPs) and no reports on the effects of Ta NPs on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and the underlying mechanisms. The main purpose of this study was to investigate the effects of Ta NPs on bone regeneration and BMSC osteogenic differentiation and the underlying mechanisms. Materials and methods The effects of Ta NPs on bone regeneration were evaluated in an animal experiment, and the effects of Ta NPs on osteogenic differentiation of BMSCs and the underlying mechanisms were evaluated in cell experiments. In the animal experiment, hematoxylin-eosin (HE) staining and hard-tissue section analysis showed that Ta NPs promoted bone regeneration, and immunohistochemistry revealed elevated expression of BMP2 and Smad4 in cells cultured with Ta NPs. Results The results of the cell experiments showed that Ta NPs promoted BMSC proliferation, alkaline phosphatase (ALP) activity, BMP2 secretion and extracellular matrix (ECM) mineralization, and the expression of related osteogenic genes and proteins (especially BMP2, Smad4 and Runx2) was upregulated under culture with Ta NPs. Smad4 expression, ALP activity, ECM mineralization, and osteogenesis-related gene and protein expression decreased after inhibiting Smad4. Conclusion These data suggest that Ta NPs have an osteogenic effect and induce bone regeneration by activating the BMP2/Smad4/Runx2 signaling pathway, which in turn causes BMSCs to undergo osteogenic differentiation. This study provides insight into the molecular mechanisms underlying the effects of Ta NPs in bone regeneration.

Fluoroethylene carbonate (FEC) has been proven an effective electrolyte additive for silicon-based Li-ion cells. However, studies have shown that it will promote the formation of acid during storage and cycling in LiPF6-based electrolyte, thus deteriorating the performance of cell. Herein, tris(trimethylsilyl)phosphite (TMSPi) and fluoroethylene carbonate (FEC) are used as combinative electrolyte additive for LiNi0.6Co0.2Mn0.2O2-SiOx/graphite (NCM622-SiOx/Gr) coin-type full cell. Electrolyte storage experiments show that TMSPi can eliminate the acid present in FEC-containing electrolyte. Theoretical calculations and electrochemical analysis confirm that TMSPi could be oxidized previously on NCM622 to optimize the cathode electrolyte interphase (CEI) and FEC can also be reduced in advance on SiOx/Gr to modify the solid electrolyte interphase (SEI). Such a full cell with 3% TMSPi + 5% FEC as electrolyte additive has the best electrochemical performance; the specific discharge capacity is maintained at 156.1 mAh g−1 after 200 cycles at rate of 1 C between 2.8 and 4.25 V. X-ray photoelectron spectroscopy results of electrode surface show that CEI has a certain amount of Li2CO3 and LixPOyFz and lower LiF, while SEI has a certain amount of Li2CO3 and LiF and less LixPOyFz, which could be beneficial to improve the cyclic stability of NCM622-SiOx/Gr full cell.

Given a social network G and a positive integer k, the influence maximization problem seeks for k nodes in G that can influence the largest number of nodes. This problem has found important applications, and a large amount of works have been devoted to identifying the few most influential users. But most of existing works only focus on the diffusion of a single idea or product in social networks. However, in reality, one company may produce multiple kinds of products and one user may also have multiple adoptions. For multiple kinds of different products with different activation costs and profits, it is crucial for the company to distribute the limited budget among multiple products in order to achieve profit maximization. The Profit Maximization with Multiple Adoptions (PM2A) problem aims to seek for a seed set within the budget to maximize the overall profit. In this paper, a Randomized Modified Greedy (RMG) algorithm based on the Reverse Influence Sampling (RIS) technique is presented for the PM2A problem, which could achieve a ( 1 − 1 / e − e ) -approximate solution with high probability and is also the best performance ratio of the PM2A problem. Comprehensive experiments on three real-world social networks are conducted, and the results demonstrate that our RMG algorithm outperforms the algorithm proposed in [16] and other heuristics in terms of profit maximization, and could better allocate the budget.

The design and development of low-cost sorbents is vital for CO2 capture from flue gases. In this study, the lignite char from Ordos coal (SE) was treated by a one-step KOH activation method to prepare microporous activated carbons for CO2 adsorption. The textural pore properties, surface functional groups and element contents of SE before and after activation were characterized and discussed; the effects of the mass ratio of KOH to SE, activation temperature and time, as well as the adsorption temperature on CO2 adsorption for prepared porous sorbents were investigated and optimized; the isosteric heat of adsorption and adsorption kinetics for the optimized sorbent were further calculated and fitted. When the mass ratio of KOH to SE was 1 : 1, the activation temperature and time were 700 °C and 120 min respectively, and the sorbent of K/SE700(120) showed an adsorption capacity of 1.35 mmol g−1 at 20 °C, which dropped by 2.96% after ten regenerations. The Langmuir adsorption isotherms fitted the adsorption data of K/SE700(120) well, and the isosteric heats of adsorption were 11–13 kJ mol−1, showing the physisorption characteristic. In addition, the good fit of the adsorption data to the Avrami model suggested that there are multiple adsorption routes for K/SE700(120).

Diseases caused by Phytophthora species seriously affect global crop production and food security. Identification of key factors involved in plant resistance is valuable for disease management. Previously, we characterized the transcriptome of Nicotiana benthamiana which was infected with Phytophthora parasitica. Here, we selected NbERF173, one of the most strongly up-regulated genes of N. benthamiana in response to P. parasitica infection, for further investigation. First, NbERF173 encodes a conserved transcription factor in our tested plant species. Second, overexpression of NbERF173 in N. benthamiana enhanced its resistance to P. parasitica, and silencing of NbERF173 significantly promoted the infection of both P. parasitica and Botrytis cinerea. Additionally, we demonstrated that NbERF173 can participate in reprograming of gene expression during P. parasitica infection and manipulate expression patterns of many defense-related genes, including two proteinase inhibitors encoding genes (PI1-B and KTI1). Furthermore, overexpression of PI1-B and KTI1 strengthened plant resistance to P. parasitica and partially restored the deficiency in resistance of NbERF173-silenced N. benthamiana plants. Finally, we found that NbERF173 could not bind to the promoters of PI1-B and KTI1 using yeast one-hybrid assay. Together, our results suggest that NbERF173 positively regulate the disease resistance, probably by reprograming of defense-related genes.

The principle of chromatographic fingerprint is that certain diagnostic metabolites should be always distributed in a given plant and currently, it has been widely accepted as a promising means for medicinal plant authentication. Moreover, the chemical profile is the only evidence to clarify the ingredients of those consumable plant products, e.g. traditional Chinese medicine (TCM) prescriptions. Herein, efforts were made to describe the diagnostic metabolome of medicinal plant or TCM prescription using a binary code sequence. Forty-five well-known medicinal plants along with six relevant prescriptions were employed for concept illustration and proof. Each plant was subjected to chemical characterization, and diagnostic metabolites of all plants were gathered into a chemical pool containing 595 compounds. A robust method enabling the detection of all 595 constituents was then developed using LC coupled to scheduled multiple reaction monitoring. Analyst™ software was responsible for automatically judging the presence (defined as “1”) or absence (defined as “0”) of each analyte with a defined signal-to-noise threshold (S/N > 100). After converting each medicinal plant to a binary sequence consisting of 595 codes, an in-house database was built by involving all sequences. The potentials of sequence library retrieval towards plant authentication, preliminary chemical characterization, and deformulation of TCM prescriptions were demonstrated after that the diagnostic metabolome of each test sample was translated to a binary code sequence. Above all, binary code is a flexible tool for diagnostic metabolite sequencing of medicinal plants, and it should be an alternative tool of DNA barcoding towards plant authentication.

An ideal 2D ferromagnetism is formed in the Ni nano-islands/graphene hybrid via graphene-mediated ferromagnetic coupling., Nanoscale magnetic structures are fundamental to the design and fabrication of spintronic devices and have exhibited tremendous potential superior to the conventional semiconductor devices. However, most of the magnetic moments in nanostructures are unstable due to size effect, and the possible solution based on exchange coupling between nanomagnetism is still not clear. Here, graphene-mediated exchange coupling between nanomagnets is demonstrated by depositing discrete superparamagnetic Ni nano-islands on single-crystal graphene. The heterostructure exhibits ideal two-dimensional (2D) ferromagnetism with clear hysteresis loops and Curie temperature up to 80 K. The intrinsic ferromagnetism in graphene and antiferromagnetic exchange coupling between graphene and Ni nano-islands are revealed by x-ray magnetic circular dichroism and density functional theory calculations. The artificial 2D ferromagnets constitute a platform to study the coupling mechanism between complex correlated electronic systems and magnetism on the nanoscale, and the results and concept provide insights into the realization of spin manipulation in quantum computing.

Breast cancer is the most common malignancy in women, and its incidence increases annually. Traditional therapies have several side effects, leading to the urgent need to explore new smart drug-delivery systems and find new therapeutic strategies. Graphene-based nanomaterials (GBNs) are potential drug carriers due to their target selectivity, easy functionalization, chemosensitization and high drug-loading capacity. Previous studies have revealed that GBNs play an important role in fighting breast cancer. Here, we have summarized the superior properties of GBNs and modifications to shape GBNs for improved function. Then, we focus on the applications of GBNs in breast cancer treatment, including drug delivery, gene therapy, phototherapy, and magnetothermal therapy (MTT), and as a platform to combine multiple therapies. Their advantages in enhancing therapeutic effects, reducing the toxicity of chemotherapeutic drugs, overcoming multidrug resistance (MDR) and inhibiting tumor metastasis are highlighted. This review aims to help evaluate GBNs as therapeutic strategies and provide additional novel ideas for their application in breast cancer therapy.

We developed an efficient method to synthesize monoligated and the corresponding bisligated iminopyridyl Ni(II) catalysts containing the same iminopyridine ligands. Subsequently, effects of monolig...

The SEE susceptibility on 28 nm Xilinx Zynq-7020 All Programmable SoC was investigated at heavy ion microbeam facilities in Institute of Modern Physics (IMP). The sensitive SEE spots distribution in entire PS area was obtained by running the on chip memory (OCM) test program. The extracted chip bottom modules layout information indicated that the SEE sensitive events occurred in the OCM area, central data processing area, and interfaces controlling buffer registers elements area, accounting for 19.6%, 32.6% and 47.8%, respectively. The results showed it was possible that the SEE events in other areas appeared more serious than in the target block located area. Meanwhile, the partial cross section was gotten in the test and it was (5.75 ± 0.85) × 10−5 cm2.

A series of unsymmetrical α-diimine palladium complexes bearing low steric crowdedness on one side and bulky substituents on the other side were prepared and characterized. Activated with sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, these α-diimine Pd(II) complexes were used to catalyze ethylene oligomerization and cooligomerization with polar monomers including methyl acrylate (MA), acrylic acid (AA) and vinyltriethoxysilane (VTEoS). In ethylene oligomerization, the hyperbranched oil products were obtained with high activities (14.2–27.0 × 103 g mol−1 h−1). The remote substituent of bulky diarylmethyl moiety showed a significant effect on catalyst activity, while exhibit little variation on the molecular weight of ethylene oligomers. In ethylene-polar monomer cooligomerization, functional and hyperbranched oils were produced and polar monomer incorporations can be tuned by the perturbations of the remote substituent.

In this study, a self-supported CFP@PANI@Fe3O4 cathode with three-layer structure was fabricated using a two-step synthetic route and characterized to reveal the morphology, composition and electrochemical performance of the novel electrode. The as-prepared CFP@PANI@Fe3O4 electrode showed enhanced electrocatalytic performance for p-nitrophenol degradation in electro-Fenton (EF) process with boron-doped diamond (BDD) electrode as anode. The results showed that for CFP@PANI@Fe3O4 cathode, 20 mg L−1 of p-nitrophenol was almost degraded in 60 min and the removal efficiency of total organic carbon (TOC) was 51.2% under the condition of applied current density 5 mA cm−2 and initial pH 3.0, which accompanied with more effective mineralization current efficiency (MCE) and less energy consumption (EC) compared with CFP and CFP@PANI electrodes. This enhancement was due to the increased electrocatalytic ability of in suit grown Fe3O4 on the surface of conductive substrates. Further investigation indicated that the fabricated electrode retained a high level of stability after consecutive runs. The reasonable reaction mechanism of p-nitrophenol was finally proposed according to the analysis of radical trapping experiments and fluorescence spectra, in which the hydroxyl radical (·OH) was deemed to the primary active oxidants. This work demonstrates the enormous potential of establishing an EF system with an efficient self-supported cathode based on in suit Fe3O4 immobilization for environmental remediation.

DNA origami is a ubiquitous nanostructure that can be used as a universal scaffold for constructing molecular motors, nanosensors, nanodrugs, and optical devices. Understanding the inherent heterogeneity of DNA origami structures is crucial for optimizing the design of high-efficiency nanosized-devices. Here, we investigated the spatial effects of the DNA origami on binding reactions using atomic force microscopy. Protein complexes formed more efficiently at the vertex and rim than on the surface of the DNA origami; surprisingly, the maximum difference in biotin-streptavidin binding efficiency was over 80%, and the change in the binding rate was approximately 40-fold, suggesting the presence of distinct microenvironments at different locations of the DNA origami. Our findings are not only useful for the potential applications of the DNA origami, but also for clarifying differences in nanomaterials caused by nonuniform distribution or defects.

Conventional Dammann grating is a binary-phase (0, π) transmission grating capable of splitting an incoming laser beam into multiple outgoing beams with equal intensity. In this paper, we present an alternative design for Dammann-type beamsplitter with a non π-phase shift value. In the design, the simulated annealing algorithm is taken to optimize the grating structure and phase difference simultaneously. We find that this non 0-π phase grating exhibits interesting properties. When the etching depth is slightly lower than the theoretical depth, the zero-order light intensity is enhanced compared to other diffraction orders. Conversely, when the etching depth is slightly greater than the theoretical depth, the zero-order light intensity is attenuated. This allows us to flexibly adjust the brightness of the zero-order diffractive light. In contrast, the deviation of the etching depth will always result in a brighter zero-order light for the conventional Dammann grating. Simulations and experiments are performed to verify the feasibility of the proposed grating.

Ochratoxin A (OTA) is a common natural contaminant found in human and animal food worldwide. Our previous work has shown that OTA can cause oxidative DNA damage, G2 arrest and malignant transformation of human gastric epithelium (GES-1) cells. Mitochondria are considered to be target for the action of many cytotoxic agents. However, the role of mitochondria in the cytotoxicity of OTA remains unknown. The aim of this study is to explore the putative role of mitochondria on OTA cytotoxicity by analyzing mitochondrial changes in GES-1 cells. The results showed that OTA treatment (5, 10, 20 µM) for different times caused increases in the production of reactive oxygen species, and induced mitochondrial damage, shown by loss of mitochondrial membrane potential (ΔΨM), and decrease in cellular ATP concentration. Subsequently, the mitochondrial apoptotic pathway was activated, presented by increase of apoptotic rate and activation of apoptotic proteins. Autophagic cell death was also triggered, demonstrated by the conversion of light chain 3B (LC3B)-I to LC3B-II and elevated levels of green fluorescent protein-LC3 (GFP-LC3) puncta. Moreover, Parkin-dependent mitophagy was also activated presented by the colocalization of MitoTracker with LysoTracker or GFP-LC3 puncta. The inhibition of autophagy and mitophagy by inhibitors or siRNA attenuated the toxic effect of OTA on cell growth. Interestingly, OTA treatment also enhanced mitochondrial biogenesis confirmed by activation of AMPK/PGC-1α/TFAM pathway and promoted cell survival. Collectively, the effects of OTA on mitochondria of GES-1 cells are complex. OTA could cause mitochondrial function disturbance, apoptotic and autophagic cell death and also induce mitochondrial biogenesis.

Tumor cells metastasizing through the bloodstream or lymphatic systems must withstand acute shear stress (ASS). Autophagy is a cell survival mechanism that functions in response to stressful conditions, but also contributes to cell death or apoptosis. We predicted that a compensation pathway to autophagy exists in tumor cells subjected to mechanical stress. We found that ASS promoted autophagosome (AP) accumulation and induced release of extracellular nanovesicles (EVs) containing autophagy components. Furthermore, we found that ASS promoted autophagic vesicles fused with multivesicular body (MVB) to form an AP-MVB compartment and then induced autophagy component release into the extracellular space via EVs through the autophagy-MVB-exosome pathway. More importantly, either increasing intracellular autophagosome accumulation or inhibiting autophagic degradation promoted AP-MVB accumulation but did not induce autophagy-associated protein release via EVs except under ASS, demonstrating the existence of a mechanical stress-dependent compensation pathway. Together, these findings revealed that EVs provide an additional protection mechanism for tumor cells and counteract autophagy to maintain cellular homeostasis under acute shear stress.

Magnesium isotope behavior in dissolution and precipitation reactions during chemical weathering have been well documented. However, mechanisms of mineral dissolution and precipitation impact on the riverine Mg isotope composition under different climatic and geology background are not well constrained, which limits Mg isotope application in weathering research. Mg isotopic compositions for solute and suspended sediments in Jinsha River Basin, located in Tibetan Plateau, China, were examined to address this issue. The δ26Mg values for dissolved loads range from −1.67‰ to −0.5‰, and the suspended loads show systematically heavier Mg isotope compositions (−1.15‰ to −0.06‰). Conservative mixing between different rock weathering end-members fails to fully explain Mg isotopic composition variation of Jinsha River waters based on mass balance and mixing model with the river geochemistry data. Mg in rivers draining dominantly carbonate and evaporite is isotopically heavier compared with the value of catchment bedrocks, and water pH and δ26Mg values are negatively correlated in carbonate (calcite and dolomite) oversaturated river waters, which suggests the precipitation of secondary carbonate as an important mechanism driving the δ26Mg of dissolved loads heavier. For carbonate unsaturated waters, Mg concentrations and δ26Mg values are intermediate between those of silicate dominated basins and carbonate oversaturated waters. The results suggest two possible different mechanisms controlling river solute δ26Mg values: fractionation during carbonate precipitation incorporating of Mg; and conservative mixing between a solute end-member formed from carbonate precipitation and end-members from rock weathering. This study provides new evidence and insights in carbonate precipitation processes regulating river Mg isotope signature and its potential influence on Mg cycling.

Copper-based materials have attracted increasing attention for their earth-abundant and cheap characters for water splitting application. In the present work, a combined structure of Co3O4 nanoparticles and CuO microsheets was constructed in an aqueous system and studied as an efficient oxygen evolution reaction (OER) electrocatalyst. NH3 molecules as the ligand of metal ions (Cu2+ and Co2+) played vital roles for the uniform growth of Co3O4@CuO microsheets. The synergetic contribution of the two components made the composite samples behave excellent OER activity and fast kinetics both on glassy carbon electrode (GCE) and nickel foam (NF) substrates in alkaline medium. The remarkable small overpotentials (310 and 394 mV) can be obtained for CuO-Co-0.2/GCE sample at current densities of 1 and 10 mA/cm2 in 1.0 mol L−1 KOH (pH = 13.6). The in-situ deposited CuO-Co-0.2/NF achieved in the aqueous synthetic system demonstrates superior (structural and electrochemical) stability for 20 h-OER performance.

Holographic laser beam shaping using a spatial light modulator can provide flexible adaptation of the intensity profile. However, speckle noise exists in the shaped beams, which reduces the beam quality seriously. In this paper, a new method is proposed to implement noise reduced flat-top beam shaping. The Gerchberg–Saxton (GS) algorithm with special spherical initial phase profile is adopted to calculate the phase-only hologram. When the spherical phase distribution is properly selected, the speckle free flat-top beam with high diffraction efficiency and low root-mean-square error can be obtained. Both simulations and experiments are performed to verify the feasibility of the proposed method. The comparison with the conventional GS algorithm using a random initial phase distribution is also carried out.

As a semi-natural ecosystem, the agroecosystem is both a major provider and a major beneficiary of ecosystem services (ES). The aim of this paper was to contribute to the scientific understanding of the current status of AES research, recognize the knowledge base and influential articles, and uncover the key research themes and how the research themes have evolved over the past decade. Bibliometric methods based on the ISI Web of Science (WoS) database were used to analyse articles related to AES published between 2008 and 2017. A total of 3573 records were evaluated during this study. The results show that there has been a significant increase in research interest in the AES field. The most frequent keywords were “Biodiversity”, “Land use change” and “Climate change”. This study divides the common keywords into 7 categories and analyses them over two periods. Agrobiodiversity and land use have been emphasized in current AES research, which is a trend that will likely continue in the future. Valuation is indispensable, but AES research has needs beyond monetary valuation. In the future, multisubject and multimethod integrative research for understanding, modelling, evaluating, and managing the AES will be more abundant.

We give two characterisations of tracially nuclear C*-algebras. The first is that the finite summand of the second dual is hyperfinite. The second is in terms of a variant of the weak* uniqueness property. The necessary condition holds for all tracially nuclear C*-algebras. When the algebra is separable, we prove the sufficiency.

This paper investigates a fuzzy disturbance observer (FDO)-based terminal sliding mode control (TSMC) strategy for the liquid-filled spacecraft with flexible structure(LFS-FS) under control saturation. Firstly, a novel FDO is designed to estimate the lumped uncertainty, including the inertia uncertainty, external disturbance, the coupling of liquid slosh and flexible structure(LF), as well as the parts that exceed control saturation. The merits of the FDO lie in that estimation error can be arbitrarily small by adjusting the designed parameters and the prior information is not required. Then, based on the estimation of FDO, a finite-time TSMC is designed, which has more satisfactory control performance, such as chattering reduction and fast convergence speed. The stability of the closed-loop system is proved strictly by Lyapunov theory. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed method.

The discovery of mechanochromic materials with multicolor conversion has mainly depended on accidents and good fortune until now, but manipulating molecular aggregation modes to achieve polymorphism is highly efficient. To obtain multicolor conversion materials and explore the intrinsic mechanism of polymorphism, TPEB2F and TPEB3F were designed and synthesized based on molecular isomerism and aggregation-induced emission (AIE) theory. Although they have similar solvatochromism and AIE properties, TPEB2F and TPEB3F show a high-contrast polymorphism and mechanochromism in terms of reversibility, fluorescence emission intensity and wavelength shift. Only crystal 2R was obtained for TPEB2F, but four different crystals 3Y, 3R, 3N and 3F exist for TPEB3F in the same solvent environment. Emission maxima of 2R show a 22 nm red shift, and its quantum yield (ΦF) was significantly increased to 0.37 from 0.09 after hard grinding. 3Y provided a maximum redshift (40 nm) and slightly reduced ΦF due to different intermolecular stacking and arrangement compared to the others, while 3N exhibited a remarkable blue shift (48 nm) and emission enhancement by gently grinding. X-ray single crystal analysis indicated that mechanochromism was not only related to intermolecular stacking and arrangement but also to the crystal system, space group and density. Theoretical calculations revealed that 2R, 3Y and 3R have an intramolecular charge transfer effect, and furthermore, the key to the formation of polymorphism mainly depends on the dipole moment of stacked molecular pairs and culture solvents rather than the minimum energy of stacked molecular pairs and the dipole moment of a single molecule. In addition, the by-product was purified and characterized in detail for the first time.

To reduce the cost of CO2 capture, polyethylene polyamine (PEPA), with a high amino density and relatively low price, was loaded into MCM-41 to prepare solid sorbents for CO2 capture from flue gases. In addition, methoxypolyethylene glycol (MPEG) was codispersed and coimpregnated with PEPA to prepare composite sorbents. The pore structures, surface functional groups, adsorption and regeneration properties for the sorbents were measured and characterized. When CO2 concentration is 15%, for 30, 40 and 50 wt% PEPA-loaded MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.15, 1.47 and 1.66 mmol g−1 at 60 °C; for 30 wt% PEPA and 20 wt% MPEG, 40 wt% PEPA and 10 wt% MPEG, and 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.97, 2.22 and 2.25 mmol g−1 at 60 °C; the breakthrough and equilibrium adsorption capacities for 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41 respectively reached 2.01 and 2.39 mmol g−1 at 50 °C, all values showed a significant increase compared to PEPA-modified MCM-41. After 10 regenerations, the equilibrium adsorption capacity for codispersed MCM-41 was reduced by 5.0%, with the regeneration performance being better than that of PEPA-loaded MCM-41, which was reduced by 7.8%. The CO2-TPD results indicated that the mutual interactions between PEPA and MPEG might change basic sites in MCM-41, thereby facilitating active site exposure and CO2 adsorption.

Atomic force microscopy-based single-molecule-force spectroscopy is limited by low throughput. We introduce addressable DNA origami to study multiple target molecules. Six target DNAs that differed by only a single base-pair mismatch were clearly differentiated a rupture force of only 4 pN.

This article describes the construction and thermal characterization of a cryogen-free cryostat designed for single-pressure refractive index gas thermometry (SPRIGT) of helium-4 in the range 5–25 K. The system is cooled using a G-M type two-stage pulse tube cryocooler. The temperature can be controlled with a standard uncertainty of 20 µK over the whole working range. The use of a thermal switch to attenuate the modulated heat flux arising from the periodic temperature oscillation of the cryocooler is described. From the temperature evolution over the whole system the thermal characteristics are estimated using a simple model.

The great orthogonality between 1H NMR spectroscopy and LC-MS implies that their deployments in series could offer an opportunity to gain the qualified molecular markers via comparative metabolomics, and an attempt was made here to propose an integrated strategy namely "from 1H NMR-based non-targeted to LC-MS-based targeted metabolomics". In-depth chemome comparisons of Cistanche plants, such as C. deserticola, C. salsa, C. tubulosa, and C. sinensis, that possess dramatic economic and ecological benefits for the arid regions in the northwest China attributing to their dramatic medicinal and edible values, were employed to verify the applicability. 1H NMR-based non-targeted matabolomics acted as the survey experiment to find those signals offering decisive contributions towards the species discrimination, and the signals were translated to a set of putative identities, eighteen ones in total, through matching with authentic compounds and referring to some accessible databases. Afterwards, an advanced LC-MS platform assembling reversed phase liquid chromatography, hydrophilic interaction liquid chromatography, and tailored multiple reaction monitoring, was introduced to simultaneously quantify those eighteen potential markers in a single analytical run, because those candidates exhibited great polarity span as well as wide content range. Significant species differences occurred amongst their chemome patterns. Echinacoside, acteoside, betaine, mannitol, 6-deoxycatalpol, sucrose, and 8-epi-loganic acid were disclosed as the markers enabling the discrimination of those four species. The findings offered an alternative tool to differentiate Cistanche plants. More importantly, the strategy namely "from 1H NMR-based non-targeted to LC-MS-based targeted metabolomics" facilitates the pursuit of molecular markers among analogue plants, and thereby provides a promising choice for in-depth chemome comparison.

Polyamines are important bioactive molecules involved in regulating H2O2 homeostasis, which is recognized as a major stimulus of oxidative stress under aluminum (Al) exposure. In this study, we investigated the involvement of spermidine oxidation in Al-induced oxidative stress, and its modulation by exogenous putrescine (Put) in two wheat genotypes differing in Al tolerance. Aluminum caused more severe oxidative damage at the root apexes in the Al-sensitive genotype Yangmai-5 than in the tolerant Xi Aimai-1, but these effects were significantly reversed by exogenous Put and polyamine oxidase (PAO) inhibitors. Aluminum caused a more significant increase in cell wall-bound PAO (CW-PAO) activity in Yangmai-5 than in Xi Aimai-1. Inhibiting of CW-PAO reduced H2O2 accumulation, restored Spd decline in both genotypes, indicating its potential role in Al-induced H2O2 production through catalyzing Spd oxidation. Additionally, Al significantly increased the activity of plasma membrane-NADPH oxidase, another H2O2 generator, in wheat roots. Put application significantly inhibited the activity of CW-PAO and plasma membrane-NADPH oxidase, and reduced H2O2 accumulation in Al-stressed wheat roots. Antioxidant enzymes were significantly stimulated by Al, but not Put. Overall, Put may protect wheat roots against Al-induced oxidative stress through regulating H2O2 production by inhibiting CW-PAO and plasma membrane-NADPH oxidase.

To explore highly efficient yellow-green light conversion agents used for agricultural film, six bay-substituted perylene diimides and their polyvinyl chloride doped films (by 0.5% weight addition) were prepared. The maximum absorption and emission peaks of the luminogens-doped polyvinyl chloride films are located at 581–609 nm and 647–667 nm, respectively. More importantly, the fluorescence quantum yields of PTCDA, t-BuOPTCDA and m-MeOPTCDA are up to 0.88, 0.84 and 0.78 in doping film, respectively. The strengthening solar radiation and outdoor exposure to sunlight last 160 min and two months respectively and the emission intensity of m-MeOPTCDA-doped film displays slight changes and 9% fluctuation in turn. Combined transmittance, compatibility, mechanical properties and thermal stability, m-MeOPTCDA is chosen as the best effective light conversion materials. To better understand the optical properties of the luminogens, molecular configuration optimization, electron cloud density distribution and molecular orbital energy levels were completed by theoretical calculation. Further, the double layer coextrusion film containing m-MeOPTCDA and Triphenyl acrylonitrile is succeed in dual band excitation(350 nm and 580 nm)and emission (430 nm and 651 nm), by optimizing the proportion of m-MeOPTCDA and Triphenyl acrylonitrile, the special light conversion films for different crops will be expected.

The authors propose a nonreciprocal phonon laser in a spinning microwave magnomechanical system, consisting of a spinning microwave resonator coupled to an yttrium-iron-garnet sphere. These results could potentially be useful for manipulating cavity magnomechanical systems through the Fizeau light-dragging effect.

Tyrosinase plays an important role in melanin biosynthesis and enzymatic browning of fresh-cut fruit and vegetables. To discover potent tyrosinase inhibitors and antibrowning agents, a series of novel kojic acid derivatives containing bioactive heterocycle moiety (4a-4l) were designed and synthesized. Thereinto, 4d displayed the most potent tyrosinase inhibitory activity with IC50 of 3.23 ± 0.26 μM and behaved as a competitive inhibitor with a Ki of 1.96 μM, compared to kojic acid (IC50 = 32.23 ± 2.01 μM). Besides, copper-chelating assay, fluorescence spectrum quenching experiment, ANS-binding fluorescence quenching analysis, and molecular modeling studies indicated that 4d may inhibit tyrosinase activity by chelating with copper ions in the active site of tyrosinase. Furthermore, 4d exhibited low cytotoxic activity and significant antibrowning effects. This study suggests that these compounds may serve as lead molecules for developing novel tyrosinase inhibitors and antibrowning agents.

Lycium fruits have a high content of phenolics as bioactive constituents with various pharmacological effects, but there is a lack of comparative analysis and chemical profiling of phenolics in Lycium fruit varieties. An ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MSE) combined with chemometrics was developed to characterize the phenolics in fruits from four Lycium species, including Lycium barbarum L. (LBL), L. chinense Mill. (LCM), L. barbarum var. auranticarpum (LBA) and L. ruthenicun Murr. (LRM). 63 phenolics were identified according to reported tandem mass fragmentation patterns and the UNIFI scientific informatics platform. Nine phenolics (5, 18, 20, 29, 31, 37, 41, 43, 60) were common and predominant components among four types of Lycium fruit. The partial least squares discriminant analysis (PLS-DA) and the orthogonal partial least squares discriminant analysis (OPLS-DA) were analyzed on the basis of a matrix created from 653 sets of data, and 20 Lycium fruits were classified into four groups. Further analysis identified that phenolics profiles were characteristic for each Lycium species, and five markers (13, 29, 31, 35, 99) could be utilized for fruit identification. Subsequently, inhibitory activity against 5α-reductase of phenolic extracts of Lycium fruits showed that LBL extract was the relative better effective, followed by LCM, whereas LBA and LRM showed no activity, which might be associated with the high contents of marker compounds (29, 31, 35, 43, 71, 99) in LBL. These findings will provide guidance for the development of Lycium phenolics with beneficial properties for the prevention and treatment of Benign prostatic hyperplasia (BPH).

In comparison of liquid chromatography, direct infusion is a superior choice to achieve high-throughput measurements. The specificity and selectivity of tandem mass spectrometry (MS/MS) actually result in a so-called MS separation potential when chemical characterization of herbal medicines. Here, a MS/MSALL program was introduced to promote DI–MS/MS to be an eligible tool for shotgun chemome characterization of Artemisia rupestris L. that is currently drawing worldwide interests because of the promising antiviral activity. After MS1 spectral acquisition for the crude extract, the gas phase fractionation concept enabled the precursor ion cohort sequentially entered the collision cell with a stepped unit mass window (step-size as 1 Da) to generate MS2 spectra, thus generating a unique property integrating the advantages of both data-dependent and data-independent acquisition manners. Even though being free of chromatographic separation, spectrometric separations were accomplished for by MS/MSALL program unless the components shared identical nominal molecular weights. Extensive efforts such as the correlations of MS1 signals with MS2 spectra, structural annotations of fragment ion species, information retrieval in some accessible databases, and referring to the literature data, were devoted for chemical characterization, and as a result, 44 compounds, in total, were structurally identified from 50% aqueous methanol exact of A. rupestris, including 8 caffeoyl quinic acid derivatives, 13 flavonoids, 15 monomeric and dimeric sesquiterpenoids, 4 fatty acids, 2 penylpropanoids, along with 2 other compounds. However, isomers were assigned as an isomeric mixture because their precursor ions always co-existed in a single mass window. Above all, DI–MS/MSALL provides an alternative tool for chemome characterization of herbal medicines, in particular when the great measurement workload for a large sample cohort, attributing to the high-throughput advantage.