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In this work, a new type of zinc(II) coordination polymer {[Zn(HIDC)(BBM)0.5]·H2O} n (Zn-CP) was synthesized using 4,5-imidazoledicarboxylic acid (H3IDC) and 2,2-(1,4-butanediyl)bis-1,3-benzimidazole (BBM) under hydrothermal conditions. Its structure has been characterized by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The Zn(II) ion is linked by the HIDC2− ligand to form a zigzag chain by chelating and bridging, and then linked by BBM to form a layered network structure. Adjacent layers are further connected by hydrogen bond interaction to form a 3-D supramolecular framework. The solid-state fluorescence performance of Zn-CP shows that compared with free H3IDC ligand, its fluorescence intensity is significantly enhanced.

Biomass-derived carbon materials prepared via pyrolysis from natural wood structures show potential for a storage application. Natural wood is composed of multiple carbon sources, including lignin, hemicellulose, and cellulose, which influence the formation and microstructure of pyrolysis carbon. However, the mechanism is not fully understood. In this work, vast lignin is selectively consumed via biodegradation with fungi from basswood. The results demonstrate that the as-prepared carbon material has a short-range ordered graphitic structure after thermal treatment. The improved graphitization degree of carbon suggests that cellulose is beneficial to graphite formation during pyrolysis. The elevated graphitization degree helps to improve the charge transfer and the thermodynamic stability of the electrode reaction. As a proof of concept, the obtained carbon current collector as a sodium-metal anode can undergo cycling at an areal capacity of 10 mAh cm-2 for over 4500 h and yield an excellent Coulombic efficiency of >99.5%.

A new silver(I) complex of the type [Ag2(mbbp)2](pic)2·DMF·CH3OH [mbbp = 2,6-bis( N-methylbenzimidazol-2-yl)pyridine] is synthesized and analyzed using a range of spectroscopic and crystallographic techniques. This compound contains cationic Ag2(mbbp)2 dimers, in which the crossed eight-shaped structure is formed by two mbbp ligands bridging two silver(I) centers and Ag–Ag bonds. Two-dimensional supramolecular networks of the silver(I) complex are connected by π···π interactions and hydrogen bonds. Hirshfeld analyses are performed to support the aforementioned intermolecular interactions. The effect of π···π stacking interactions on the fluorescence properties of the complex is investigated. Cyclic voltammetry indicates two irreversible redox processes. In addition, an antioxidant assay in vitro demonstrates that the silver(I) complex displays excellent scavenging activity toward hydroxyl radicals.

Bis(N-ethylbenzimidazol-2-ylmethyl)allylamine (EtAIDB) and its two complexes, [Mn(EtAIDB)Cl2] (1) and [Zn(EtAIDB)Cl2] (2), have been synthesized and characterized by elemental analyses, molar conductivities, UV–Visible and IR spectra. The crystal structures of both complexes have been determined by X-ray single crystal diffraction. The coordination environment of Mn(II) in 1 is a five-coordinate distorted trigonal bipyramid with a N3Cl2 ligand set, while 2 is a four-coordinate twisted tetrahedral geometry. Structural and Hirshfeld surface analysis reveals that these two complexes are dimers formed by π···π interactions. The antioxidant activity was determined by superoxide methods in vitro, indicating that 1 exhibited potential antioxidant properties.

A bicomponent anion exchange membrane (AEM) in the form of poly(vinylbenzyl chloride) (PVBC) cross-linked by polybenzimidazole (PBI) and quaternized by N-methylpiperidine (NMPD) is provided. On the...

Hadamard coding spectral imaging technology is a computational spectral imaging technology that modulates the target’s spectral information and recovers the original spectrum by the inverse transfo...

Hydrogen is believed to be an important energy storage vector to fully exploit the benefit of renewable and sustainable energy. Rubber seals are widely used in high-pressure hydrogen storage system, which may cause the occurrence of fracture or deterioration behavior inside the rubber, leading to a leak of explosive hydrogen. Thus, the effect of high-pressure hydrogen on the properties of rubber seals needs to be studied. In this paper, the material properties of rubber exposed to high-pressure hydrogen are elaborated, including transport properties, chemical structure, mechanical properties, rapid gas decompression and swelling. Simultaneously the sealing performance of rubber rings under high-pressure hydrogen is also presented, consisting of static and dynamic sealing characteristics. At the end of the article, some issues are proposed to provide reference train of thought for future research, involving types of fillers and rubbers, failure modes, impact of degradation on sealing performance, key parameters and design parameters, and effects of temperature and pressure.

Nidulaxanthone A (1), a xanthone dimer bearing an unprecedented heptacyclic 6/6/6/6/6/6/6 system, together with a new monomeric nidulalin D (2) and four known analogues (3, 4, 5 and 6), were isolated from Aspergillus sp. F029. Biosynthetically, 1 was likely generated via [4 + 2] cycloaddition of precursor 3. Compounds 1, 2, and 3 exhibited cytotoxicity with IC50 values ranging from 3.2 to 21.9 μM, and antibacterial activity with MIC50 values of 13.2 and 19.6 μg ml−1 for 2 and 3, respectively.

Methanol (MeOH) in exhaled breath has potential for non-invasive assessment of intestinal flora. In this study, we have developed a biochemical gas sensor (bio-sniffer) for MeOH in the gas phase using fluorometry and a cascade reaction with two enzymes, alcohol oxidase (AOD) and formaldehyde dehydrogenase (FALDH). In the cascade reaction, oxidation of MeOH was initially catalyzed by AOD to produce formaldehyde, and then this formaldehyde was successively oxidized via FALDH catalysis together with reduction of oxidized form of β-nicotinamide adenine dinucleotide (NAD+). As a result of the cascade reaction, reduced form of NAD (NADH) was produced, and MeOH vapor was measured by detecting autofluorescence of NADH. In the development of the MeOH bio-sniffer, three conditions were optimized: selecting a suitable FALDH for better discrimination of MeOH from ethanol in the cascade reaction, buffer pH that maximizes the cascade reaction, and materials and methods to prevent leaking of NAD+ solution from an AOD-FALDH membrane. The dynamic range of the constructed MeOH bio-sniffer was 0.32–20 ppm, which encompassed the MeOH concentration in exhaled breath of healthy people. The measurement of exhaled breath of a healthy subject showed a similar sensorgram to the standard MeOH vapor. These results suggest that the MeOH bio-sniffer exploiting the cascade reaction will become a powerful tool for the non-invasive intestinal flora testing.

Injectable hydrogel provides a new advance on lubrication of artificial joints due to its in situ forming property and long-term release effect. The adaptability improvement of the injectable hydrogel is crucial for its successful application in joint prostheses without weakening its injectable performance. In this paper, we reported a thermosensitive poly(e-caprolactone)-poly(ethylene glycol)-poly(e-caprolactone) (PCEC) hydrogel embedded with carbon nanotubes (CNT) to improve its shear resistance and strain resistance. The phase-transition test demonstrated that the temperature range at the gel state for the PCEC/CNT hydrogel is higher than that of PCEC hydrogel under identical condition. We also demonstrated the CNT enhance the viscoelasticity of the thermosensitive PCEC hydrogel under the premise of retaining the effective slow-release behavior of bull serum albumin. The PCEC/CNT composite hydrogel has excellent slow-release and release-lubrication effects while maintaining its injectability. Consequently, it shows a promising application prospect as an injectable carrier, which provides slow-release lubrication effect on artificial joints.

A new diketopiperazine cyclo-(L-Phe-N-ethyl-L-Glu) (1), along with two known diketopiperazines cyclo-(L-Pro-L-Leu) (2) and cyclo-(L-Pro-L-Phe) (3) were isolated from the cultures of an endophytic fungus Aspergillus aculeatus F027. The structures of these compounds were elucidated based on spectroscopic data. The configurations of these compounds were determined by advanced Marfey's analysis. Antibacterial activity of the diketopiperazines against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were also evaluated.Supplemental data for this article can be accessed at https://doi.org/10.1080/14786419.2019.1677652.

Renal cell carcinoma (RCC) is one of the most common malignancies worldwide, and metabolic reprogramming has a profound effect on RCC tumorigenesis. mTORC1 inhibitors are widely used in RCC treatment, yet some types of RCC cells are resistant to these compounds. Thus, clarification of the metabolic mechanism of mTORC1 inhibitors and exploration of new therapeutic approaches are urgently needed. In this study, we found that the mTORC1 pathway was hyperactive in RCC. Immunohistochemistry and western blot analysis showed that phosphorylation of the mTORC1 substrate 4EBP1 at threonine 37/46 increased in RCC tissues compared with that in normal renal tissues. It was also found that mTORC1 inhibitor everolimus suppressed glucose consumption, lactate production, and multiple catalytic enzymes involved in glycolysis in 786-O and ACHN cells, but the accumulation of HIF1α induced by CoCl2 blocked the inhibitory effect of everolimus on aerobic glycolysis. Interestingly, western blot and metabolite analysis showed that the tumor suppressor NDRG2 (N-Myc downstream regulated gene 2) was able to inhibit mTORC1 activity and cooperate with an mTOR inhibitor to decrease aerobic glycolysis in 786-O and ACHN cells. These results demonstrate that NDRG2 may potentially synergize with mTORC1 inhibitors to suppress malignant phenotype of RCC. Taken together, these data provided preclinical evidence that the combination of NDRG2 and mTORC1 inhibitors might be a promising strategy for RCC therapy.

Recently, the design of biomimetic enzymes based on ultrathin two-dimension (2D) metal-organic framework (MOF) nanosheets have attracted great attention due to their large surface area and abundant accessible active sites. In this work, ultrathin 2D MOF nanosheets and multi-walled carbon nanotubes (MWCNTs) are simply mixed to prepare the composite (2D MOF/MWCNT) films though a Langmuir–Schafer method. The 2D MOF/MWCNT films are easily transferred on electrodes as a novel electrochemical platform for the detection of hydrogen peroxide (H2O2), with a detection limit of 0.70 μM (S/N = 3), a wide linear range from 0.001 to 8.159 mM, a high sensitivity of 157 μA cm−2 mM−1, a short response time of

N6-methyladenosine (m6A) is the most prevalent internal modification present in the mRNAs of all higher eukaryotes, where it is present within both coding and noncoding regions. In mammals, methylation requires the catalysis of a multicomponent m6A methyltransferase complex. Proposed biological functions for m6A modification include pre-mRNA splicing, RNA stability, cell fate regulation, and embryonic development. However, few studies have been conducted on m6A modification in trees. In particular, the regulation mechanism of RNA m6A in Populus development remains to be further elucidated. Here, we show that PtrMTA (Populus trichocarpa methyltransferase) was colocalized with PtrFIP37 in the nucleus. Importantly, the PtrMTA-overexpressing plants significantly increased the density of trichomes and exhibited a more developed root system than that of wild-type controls. Moreover, we found that PtrMTA-overexpressing plants had better tolerance to drought stress. We also found PtrMTA was a component of the m6A methyltransferase complex, which participated in the formation of m6A methylation in poplar. Taken together, these results demonstrate that PtrMTA is involved in drought resistance by affecting the development of trichomes and roots, which will provide new clues for the study of RNA m6A modification and expand our understanding of the epigenetic molecular mechanism in woody plants.

Optical fiber surface-enhanced Raman scattering (SERS) probes provide a novel platform for liquid-phase in situ and remote SERS detections. However, it is still a challenge to fabricate noble metal nanostructures with large SERS enhancement factor (EF) onto optical fiber surfaces. In this article, we successfully prepare Au-nanorod cluster structures on optical fiber facets by a laboratory-developed laser-induced evaporation self-assembly method. It is demonstrated that the optimized optical fiber SERS probes show high detection sensitivity (10−10 M for rhodamine 6G solution, and 10−8 M for malachite green or crystal violet solution) and excellent reproducibility (relative standard deviation less than 6%). As the laser-induced evaporation self-assembly method is a simple and low-cost method capable of achieving automatic and reproducible preparations of cluster patterned optical fiber SERS probes, this work may find important application prospects in various liquid-phase SERS detection areas.

For the first time, a reproducible surface plasmon-enhanced optical sensor for the detection of gaseous formaldehyde was proposed, which was fabricated by depositing a mixture of CdSe@ZnS quantum dots (QDs), fumed silica (FS), and gold nanoparticles (GNs) on the surface of a silica sphere array to meet the urgent requirement of a rapid, sensitive, and highly convenient formaldehyde detection method. Because of the spectral overlap between QDs and GNs, plasmon-enhanced fluorescence was observed in the film of QDs/FS/GNs. When exposed to formaldehyde molecules, the enhanced fluorescence was quenched linearly with the increase of formaldehyde concentration in the range of 0.5-2.0 ppm. The reason is attributed to the nonradiative electron transfer from QDs to the carbonyl of formaldehyde molecules with the assistance of amino groups. Our results demonstrate that the designed sensors are capable of detecting ultralow concentration gaseous formaldehyde at room temperature with a fast response-recovery time and excellent selectivity, stability, and reproducibility. This work provides a simple and low-cost approach for optical formaldehyde sensor fabrication and shows promising applications in environmental detection.

It is a great challenge to fabricate electrode with simultaneous high activity for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, a high‐performance bifunctional electrode formed by vertically depositing a porous nanoplate array on the surface of nickel foam is provided, where the nanoplate is made up by the interconnection of trinary Ni–Fe–Mo suboxides and Ni nanoparticles. The amorphous Ni–Fe–Mo suboxide and its in situ transformed amorphous Ni–Fe–Mo (oxy)hydroxide acts as the main active species for HER and OER, respectively. The conductive network built by Ni nanoparticles provides rapid electron transfer to active sites. Moreover, the hydrophilic and aerophobic electrode surface together with the hierarchical pore structure facilitate mass transfer. The corresponding water electrolyzer demonstrates low cell voltage (1.50 V @ 10 mA cm−2 and 1.63 V @ 100 mA cm−2) with high durability at 500 mA cm−2 for at least 100 h in 1 m KOH., A high‐performance bifunctional electrode in the form of a porous nanoplate array vertically aligned on nickel foam for overall water splitting is provided. The porous nanoplate is built by the interconnection of trinary Ni–Fe–Mo suboxides and Ni nanoparticles, which is featured with amorphous active material and rapid electron/mass transfer.

A new drug, Caba-780, was synthesized by chemical coupling of the heptamethyl phthalocyanine near-infrared fluorescent (NIRF) dye IR-780 and the paclitaxel-based chemotherapeutic drug cabazitaxel. Then, the potential value of Caba-780 in the diagnosis and treatment of castration-resistant prostate cancer (CRPC) was evaluated. The CRPC cell lines DU145 and PC-3, as well as the normal human prostate stromal cell line WPMY-1, were used to evaluate the uptake of Caba-780 and its antitumor effect in vitro. The distribution, antitumor effect, and safety of Caba-780 were also evaluated in tumor-bearing mouse xenograft models. Our results showed that Caba-780 was efficiently absorbed by DU145 and PC-3 cells and that the cytotoxicity of Caba-780 was significantly stronger than that of IR-780 and cabazitaxel. In addition, Caba-780 inhibited the migration and invasion of DU145 and PC-3 cells and promoted apoptosis by prolonging the G2 phase of the cell cycle. Further analysis indicated that Caba-780 could be used to effectively image tumor xenografts. At the same time, this drug inhibited the growth of tumors in vivo. Therefore, the new synthetic drug Caba-780 has potential applications in the diagnosis and treatment of CRPC.

Two new zinc(II) and manganese(II) complexes with the ligand 1,3-bis(1-allylbenzimidazol-2-yl)-2-oxopropane (aobb), with composition [Zn(aobb)2](pic)2·DMF·CH3OH (1) and [Mn(aobb)(DMF)2(H2O)] (pic)2 (2) (pic = picrate; DMF = N,N-dimethylformamide), have been synthesized and characterized by elemental analysis, electrical conductivities, X-ray single-crystal diffraction, IR, and UV–vis spectra. Single-crystal X-ray revealed that Zn(II) and Mn(II) centers are both located in the six-coordinate distorted octahedral geometry. The DNA-binding modes of the ligand and the complexes were investigated by electronic absorption titration, competitive binding with ethidium bromide and viscosity measurements. The experimental evidence indicated the ligand and complexes interact with calf thymus DNA through intercalation. The binding strength follows the order 2 > 1 > aobb. Additionally, 2 displays potential superoxide dismutase activity in vitro studies.

Through feeding 1,2-dimethylindole, two new bisindoles, chaetoindolone E and F (1 and 2) and five known indole derivatives (3–7) were isolated from the cultures of an endophytic fungus Chaetomium sp. The structures of these compounds were elucidated based on HR-MS, NMR and single-crystal X-ray crystallography. Compounds 1 and 2 were undescribed before, compounds 3–7 were first reported from natural sources, and NMR spectrums of compounds 4 and 5 were first reported. The cytotoxity of the bisindole compounds (1–3) was also tested.

A new benzophenanthridine alkaloid, 2,3,9-trimethoxy-7,8-methylenedioxy-5-methylbenzo[c]-6(5H) phenanthridone (2) and a benzophenanthridine alkaloid first found from natural sources, 2,3-dimethoxy-7,8- methylenedioxy-5-methylbenzo[c]-6(5H)- phenanthridone (1) together with two known benzophenanthridine alkaloids, Dihydrosanguinarine (3) and Dihydrochelilutine (4) were isolated from the roots of Thalictrum microgynum Lecoy.ex Oliv. The structures of 1 and 2 were elucidated using various spectroscopic techniques including HRESIMS and 1 D and 2 D NMR. Antibacterial activity of these compounds were tested. Compound 1, 3 and 4 showed antibacterial activity against Staphylococcus aureus with MIC values of 50, 100, 25 μg/mL, respectively.

Red phosphorus (RP) as the anode material for the sodium-ion battery (SIB) possesses a high energy density, but the poor electronic conductivity and huge volume change during Na+ insertion/extraction restrict its application. In this work, the edible fungus slag-derived porous carbon (PC) is adopted as a carbon matrix to combine with RP to form PC@RP composites through a facile vaporization-condensation approach. The conductive porous carbon architecture improves the transfer of electron and Na+ in the composite. The robust carbon framework together with the chemical bonding between PC and RP effectively buffer the huge volumetric change of RP. As a result, the PC@RP composite material delivers a specific capacity of 655.1 mA h g-1 at 0.1 A g-1 with a capacity retention of 87% after 100 charging/discharging cycles. In particular, the full SIB assembled with P2-Na2/3Ni1/3Mn1/3Ti1/3O2 as the cathode material and PC@RP as the anode material exhibits a specific capacity of 77.3 mA h g-1 (based on the mass of cathode material) at 0.5 C, and 85% capacity is retained after 100 charging/discharging cycles.

The development of bifunctional electrocatalysts with high performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with earth-abundant elements is still a challenge in electrochemical water splitting technology. Herein, we fabricated a free-standing electrocatalyst in the form of vertically oriented Fe-doped Ni3S2 nanosheet array grown on three-dimensional (3D) Ni foam (Fe-Ni3S2/NF), which presented a high activity and durability for both HER and OER in alkaline media. On the basis of systematic experiments and calculation, the Fe-doping was evidenced to increase the electrochemical surface area, improve the water adsorption ability, and optimize the hydrogen adsorption energy of Ni3S2, which resulted in the enhancement of HER activity on Fe-Ni3S2/NF. Moreover, metal sites of Fe-Ni3S2/NF were proved to play a significant role in the HER process. During the catalysis of OER, the formation of Ni–Fe (oxy)hydroxide was observed on the near-surface section of Fe-Ni3S2/NF, and...

Autophagy is an intracellular catabolic mechanism essential for recycling intracellular unfolding protein and eliminating toxic protein aggregates. Several studies have shown that deficient autophagy is implicated in the development of Alzheimer's disease (AD) progression. To date, rapidly emerging evidence suggests that neurosteroid progesterone (PG) may play an important role in ameliorating AD. However, the role of PG and its neuroprotective mechanism in regulating autophagy still require further investigation. Here, we investigated the protective effects of PG against Aβ-induced inflammatory responses in astrocytes and its underlying mechanism in mediating autophagy. Remarkably, Aβ induced astrocyte dysfunction in autophagic activation and up-regulated inflammatory secretion. However, the autophagy inducer rapamycin (RAPA) significantly suppressed Aβ-induced inflammation in astrocytes. In astrocytes, treatment with Aβ caused autophagy deficiency, whereas PG significantly increased autophagy activation. Finally, PG suppressed Aβ-induced neuroinflammatory production via enhancing autophagy together with regulating mTOR signaling. Taken together, these results show that autophagy is a vital mechanism against Aβ-induced neuroinflammatory responses in astrocytes and demonstrate the potential neuroprotective mechanism of PG in suppressing neuroinflammatory responses by enhancing autophagy. Therefore, uncovering the neuroprotective mechanism of PG may provide new insight into novel therapies for the amelioration of AD.

The photo-mediated “metal-free” atom transfer radical polymerization approach has been investigated for the first time to polymerize methyl methacrylate, N,N-dimethylamino-2-ethyl methacrylate, 2-([4,6-dichlorotriazin-2-yl]oxy)ethyl methacrylate and a mixture of methyl methacrylate and 1-pyrenemethyl methacrylate from a regioregular poly(3-hexylthiophene) (P3HT) macroinitiator to produce well-defined rod–coil conjugated diblock copolymers, highly relevant for use as organic electronic materials without metal catalyst contamination. This was achieved using pyrene and a pyrenyl N-substituted phenothiazine (PPTh) as UV light photoredox catalysts. Spectral and chromatographic results revealed that the applied synthetic approach generated P3HT-based diblock copolymers in a controlled manner and with narrow molecular weight distributions (Đ ≤ 1.3). From a comparison of the efficiency of the photocatalysts, PPTh has shown advantages over pyrene, including much lower catalyst content and higher polymerization conversions.

Two new one-dimensional (1D) double-chain Ag(I) coordination polymers, namely: {[Ag(Hcn)(bpy)]·2CH3OH}n (1), [Ag2(Hidc)(H2O)2]n (2) (Hcn = 2-hydroxycinnamate, bpy = 4,4′-bipyridine, Hidc = 4,5-imidazoledicarboxylate), were synthesized by volatilization method and characterized by single-crystal X-ray diffraction, elemental analysis, IR and UV–vis spectra. Single-crystal analyses show that although two Ag(I) CPs are both 1D double-chain structure constructed by Ag-Ag bonds, CP 1 is linear, while CP 2 is zigzagged. This difference in the structure may be due to the symmetry of the repeat unit of the Ag(I) CPs and the linkage pattern of the Ag-Ag bonds, in which the repeat unit of CP 1 is symmetric, whereas that of CP 2 is asymmetric. The fluorescence properties of the ligands and CPs 1-2 in the solid-state were studied. The fluorescence peaks of the two Ag(I) CPs were weakened compared to the ligands, which is attributed to ligand-centered fluorescence. The partial quenching of the aggregates may be due to the Ag-Ag interactions. In addition, cyclic voltammograms of CPs 1-2 indicated an irreversible Ag+/Ag couple with the order of reversibility being 1 > 2.

Three heteronuclear Cd–Ln clusters based on open-chain ether Schiff (bis(5-bromine-3-methoxysalicylidene)-3-oxapentane-1,5-diamine (H2L) and niacin (NA), with composition [Cd6Ln4L5 (OAc)5(NA)5(CH3OH)5](NO3)4·x(CH3OH)·y(CH2Cl2) (1 Ln = Sm, x = 1, y = 1; 2 Ln = Eu, x = 0, y = 1; 3 Ln = Tb, x = 2, y = 1), have been synthesized and structural characterizated. The structure analysis reveals that 1–3 contain the similar sandwich-type polycationic unit [Cd6Ln4L5(OAc)5(NA)5(CH3OH)5]4+. Solid-state luminescence studies show that the emission peaks of the H2L ligand located in the range of 340 ~ 373 nm in 1–3. The characteristic emission peaks of Sm3+ ion appear in cluster 1, but there is no Eu3+ or Tb3+ ion emission peak in clusters 2 and 3. The fluorescence spectra of 1–3 in N,N-dimethylformamide (DMF) solution only appear emission peaks of π*→π transition of [CdL] coordination units, but characteristic emission peaks of Ln3+ ions didn’t emerge. It is possible that the DMF molecules impeded the energy transfer from [CdL] coordination units to the lanthanum(III) ions. Moreover, antioxidation properties indicate that H2L and 1–3 have outstanding biological activity in scavenging oxygen free radicals.

Chiral compounds play a vital role in our lives because we are made up of chiral polymers. A strict rule of chirality synthesis is “to obtain one enantiomer of a new chiral product, one enantiomer of a chiral source is needed”. If two enantiomers can be synthesized using a single chiral compound, we can both break the above rule and open up a more efficient route to useful chiral materials using a cheaper chiral source. Here we report the first example of double reversals of enantioselectivity in catalytic asymmetric polymerization of achiral monomers using a single isomer of simple chiral compounds as cocatalyst. Furthermore, we achieved this by changing only one achiral condition, that is, the amount of the chiral cocatalyst, without any other changes in the polymerization conditions. As a result, we easily and directly synthesized (+)- or (−)-polymer using a single chiral compound as a cocatalyst.

The development of high-performance electrocatalyst with earth-abundant elements for water-splitting is a key factor to improve its cost efficiency. Herein, a noble metal-free bifunctional electrocatalyst was synthesized by a facile pyrolysis method using sucrose, urea, Co(NO3)2 and sulfur powder as raw materials. During the fabrication process, Co, S co-doped graphitic carbon nitride (g-C3N4) was first produced, and then this in-situ-formed template further induced the generation of a Co, N, S tri-doped graphene coupled with Co nanoparticles (NPs) in the following pyrolysis process. The effect of pyrolysis temperature (700, 800, and 900 °C) on the physical properties and electrochemical performances of the final product was studied. Thanks to the increased number of graphene layer encapsulated Co NPs, higher graphitization degree of carbon matrix and the existence of hierarchical macro/meso pores, the composite electrocatalyst prepared under 900 °C presented the best activity for both hydrogen evolution ...

Core-shell nanostructures have been widely investigated to improve the electrocatalytic performance of platinum. However, organic precursors, surfactants or high temperature are usually necessary during the preparation procedure. Unfortunately, these requirements limit the application of these methods on a large scale. Herein, a Pdcore@Ptshell nanostructure was fabricated through the reduction of K2PtCl4 by dissociated hydrogen at room temperature without the assistance of either a surfactant or a high-boiling point solvent. The shell thickness of this nanostructure was successfully controlled by varying the amount of K2PtCl4; core-shell nanoparticles with a shell thickness of 0.45, 0.75 and 0.90 nm were obtained, as determined by TEM. The remarkable crystallinity and epitaxial growth of the Pdcore@Ptshell nanostructure were revealed by HRTEM and EDS. According to ICP and XPS, surface segregation of Pt was established. The impressive ORR performance was attributed to the weak adsorption strength of the OHads species, which resulted from the electron transfer impact between the Pdcore and Ptshell. The facile and clean preparation method can be used to prepare other core-shell nanostructures under a mild atmosphere.

In order to effectively utilize low grade energy at different temperatures, this paper presents three systems using liquefied nature gas (LNG) as cold source. 16 potential applicable organic working fluids are selected for different cycles and systems. In the meantime, thermodynamic and thermal-economic analysis and comparison based on a multi-objective optimal model has been done. The results indicate that, when the temperature of low grade energy is below 370 K, the single-system has the best performance, and the tripartite-system has the best performance when the temperature is above 370 K. Propane emerges as the most suitable working fluid for single-system and R245fa for tripartite-system. Meanwhile, best work conditions have been calculated for single-system and tripartite-system. Moreover, the turbine's cost is the largest for both systems because of the large expansion ratio.

Palladium nanocrystals (NCs) are highly useful functional materials in many applications, and the performances of Pd NCs were strongly depended on the crystalline facet exposed on their surface. In this work, Pd NCs were synthesized in aqueous solutions by using Na2PdCl4 as the precursor, citric acid as the capping agent, and Pluronic F127 as both stabilizer and reductant. By adjusting the reaction parameters, Pd cuboctahedrons, octahedrons, and triangular nanoplates with well-defined facets can be produced. This study provides a new pathway for the shape-controlled preparation of noble metal NCs.

The spinel Li4Ti5O12/rutile-TiO2@carbon (LTO-RTO@C) composites were fabricated via a hydrothermal method combined with calcination treatment employing glucose as carbon source. The carbon coating layer and the in situ formed rutile-TiO2 can effectively enhance the electric conductivity and provide quick Li+ diffusion pathways for Li4Ti5O12. When used as an anode material for lithium-ion batteries, the rate capability and cycling stability of LTO-RTO@C composites were improved in comparison with those of pure Li4Ti5O12 or Li4Ti5O12/rutile-TiO2. Moreover, the potential of approximately 1.8 V rechargeable full lithium-ion batteries has been achieved by utilizing an LTO-RTO@C anode and a LiFePO4@N-doped carbon cathode.

Rational design of inexpensive, highly active, and long-term stable non-precious metal electrocatalysts for oxygen reduction reaction (ORR) is of significant importance for large-scale applications of fuel cells in practice. In this paper, we report, for the first time, the construction of 2D layered mesoporous transition metal-nitrogen-doped carbon/nitrogen-doped graphene (meso-M-N-C/N-G, M = Fe, Co, and Ni) electrocatalysts using 4,4-bipyridine as the nitrogen and carbon source and mesoporous KIT-6/N-G generated by in situ formation of KIT-6 on graphene nanosheets as a template. The meso-Fe-N-C/N-G electrocatalyst showed super electrocatalytic performance for ORR. Excitingly, its catalytic activity and durability were superior to those of Pt/C, making it a good candidate as an ORR electrocatalyst in fuel cells. The results suggested that the outstanding electrocatalytic performance of the electrocatalysts could be attributed to the unique mesoporous structure, high surface area, ultrasmall size of Fe or FeOx nanocrystals embedded in 2D layered N-G nanosheets, excellent electron transportation, homogeneous distribution of high-density pyridinic N and graphitic N, graphitic C, and abundant metal active sites (Fe-Nx). The synthesis approach can be used as a versatile route toward the construction of various 2D layered graphene-based mesoporous materials.

The stereo-defects and its distribution of four homo- and co-polypropylene samples with different processing properties were studied through the correct design Successive Self-Nucleation and Annealing (SSA), and other characterization methods such as Differential Scanning Calorimetry (DSC), Gel Permeation Chromatography (GPC), Temperature Rising Elution Fractionation (TREF), respectively. Firstly, the preliminary characterization found that the two homo-polypropylene or co-polypropylene samples had the similar mechanical and thermal properties, and the SSA results also revealed the internal microstructure of the different kind of polypropylene was almost exactly the same, representing the alike isotactic sequence length, the fractions weight of the isotactic sequence, and the isotactic sequence length distribution of the same kind of polypropylene. Compared with the homo-polypropylene, the DSC, GPC, and TREF tests indicated there were difference in the properties of the co-polypropylene samples, revealing the disparities in molecular chain microstructure. The SSA results after the correct Ts for each sample showed there were obvious differences in the (statistical) lamellar thickness and its distribution and the fractions weight of different fractions after SSA treatment, further revealing the microstructure difference on the isotactic sequence length, and the isotactic sequence length distribution of homo- and co-polypropylene samples. Besides, the correct design SSA also indicated the polar copolymer monomer had a great influence on the high isotactic component in co-polypropylene microstructure.

A method for the determination of complex refractivity based on reflection measurements of rough surfaces is proposed. The reflection spectra of a polished reflector and three different aluminum alloy rough surfaces are measured using a Fourier transform spectrometer. Using the Kirchhoff approximation, the relationship between the root mean square roughness and the natural logarithm of reflectance is deduced. Then, the numerical reflection spectra of a smooth surface, verified by the measured spectra of a polished reflector, are determined using the least squares method. The complex refractivity is subsequently extracted using the Kramers-Kronig relation, and the obtained results agree with the refractivity measured with an ellipsometer. The advantage of this scheme is that it immediately obtains complex refractivity from rough surfaces, which is more efficient for the fabrication of samples and the operation of retrieval systems.

The promising Pt-based ternary catalyst is crucial for polymer electrolyte membrane fuel cells (PEMFCs) due to improving catalytic activity and durability for both methanol oxidation reaction and oxygen reduction reaction. In this work, a facile strategy is used for the synthesis ternary RuMPt (M = Fe, Co, Ni, and Cu) nanodendrities catalysts. The ternary RuMPt alloys exhibit enhanced specific and mass activity, positive half-wave potential, and long-term stability, compared with binary Pt-based alloy and the commercial Pt/C catalyst, which is attributed to the high electron density and upshifting of the d-band center for Pt atoms, and synergistic catalytic effects among Pt, M, and Ru atoms by introducing a transition metal. Impressively, the ternary RuCoPt catalyst exhibits superior mass activity (801.59 mA mg −1 ) and positive half-wave potential (0.857 V vs . RHE) towards MOR and ORR, respectively. Thus, the RuMPt nanocomposite is a very promising material to be used as dual electrocatalyst in the application of PEMFCs.

By using a living one-handed helical cis-transoidal poly(chiral substituted phenylacetylene) as a polymer initiator (poly(1n)), helix-sense-selective polymerization (HSSP) of an achiral phenylacetylene 2 having two hydroxy groups successfully afforded a diblock copoly(phenylacetylene) (copoly(1n/2m)) consisting of a dynamic one-handed helical cis-transoidal block and a static one-handed helical cis-cisoidal block. The formation of the diblock structure was confirmed by consumption of the chiral initiator, appearance of characteristic CD indicating the one-handed helical cis-cisoidal block, and occurrence of the selective photocylic aromatization reaction in the cis-cisoidal block. Therefore, HSSP has been achieved by using the chiral alkenyl groups in the initiator as a chiral source for the first time. In addition, since the HSSP was achieved in spite of the long distance between the chiral initiation site and the propagating site, chiral teleinduction through the rigid and static one-handed helical cis-...

A possible correlation between liver cancer pain and the hypoxia-inducible factor (HIF)-1 and vascular endothelial growth factor (VEGF) expression levels was examined. From January, 2015 to January, 2016, 30 patients suffering from liver cancer with pain, 30 patients with liver cancer without pain and 30 hepatitis patients with pain were enrolled in the study. Pain level was evaluated by visual analogue scale (VAS), the expression levels of HIF-1 and VEGF mRNA were determined by RT-PCR and the expression levels of HIF-1 and VEGF proteins were examined by ELISA. Before intervention, the VAS in the hepatitis group was significantly higher than that of the liver cancer pain group. However, after intervention the VAS in the two groups was reduced. HIF-1 and VEGF mRNA expression levels in the liver cancer pain group were significantly higher than those in the liver cancer group before and after intervention. The expression levels of HIF-1 and VEGF mRNA in the hepatitis group were the lowest. The expression levels of HIF-1 and VEGF mRNA in the liver cancer pain group considerably increased after intervention. The expression levels of HIF-1 and VEGF mRNA in the other two groups showed no changes before or after intervention. Before and after the intervention, VAS in the liver cancer pain group was positively correlated to the expression levels of HIF-1 and VEGF. Thus, pain occurrence and the pain level in liver cancer patients were correlated with the expression levels of HIF-1 and VEGF. As the regular three-step medicine analgesic ladder is ineffective in these cases, verification of HIF-1 and VEGF expression levels may be considered the new target for pain release.

BACKGROUND Laryngeal cancer is one of the most common malignant tumors of the head and neck. Natural compounds in traditional Chinese medicine provide many valuable potential compounds for tumor chemotherapy. Esculetin, a coumarin derivative from several herbs, inhibits proliferation of many types of cancer cells, but its anticancer effect in laryngeal cancer is still not clear. MATERIAL AND METHODS We performed in vitro proliferation assay, invasion assay, and migration assay to assess the effect of esculetin against LC, and in vivo nude mouse xenograft animal model was used as well. Flow cytometry was conducted to analyze the effect of esculetin on cell cycle of LC cells, and Western blot analysis was used to assess the effect esculetin on the JAK-STAT signaling pathway. RESULTS Esculetin remarkably inhibits proliferation, migration, and invasion of LC cells, and reduces in vivo xenograft tumor growth and tumor weight in a dose-dependent manner. Our molecular mechanism study demonstrated that esculetin significantly inhibits STAT3 phosphorylation and blocks translocation of STAT3 into the nucleus, and esculetin also blocks the cell cycle in G1/S phase. CONCLUSIONS In a summary, by inhibiting the STAT3 activation, esculetin shows potential anticancer effects against the laryngeal cancer.

Transition metal sulfide is considered as a kind of promising noble metal-free material for hydrogen evolution reaction (HER). However, most of conventional sulfurization methods require high temperature and/or long reaction time. Herein, a sulfurization strategy at room temperature (25 °C) by using Na2S in aqueous solution is applied to sulfurize nickel foam-supported nickel-cobalt carbonate hydroxide nanowire array, during which amorphous sulfide gradually forms on the surface of nanowire and finally replaces the nanowire completely. It is found that the electrode sulfurized for 5 min in which only a thin sulfide layer is formed presents nearly identical catalytic performance for HER with the electrode that is sufficiently sulfurized for 120 min. The electrode sulfurized at 25 °C for 5 min only needs an overpotential of 100 mV to achieve hydrogen evolution current at 10 mA cm−2 in 1 M KOH, and negligible loss of activity is observed after working at a current density of 20 mA cm−2 for 25 h. The interface between carbonate hydroxide and sulfide is considered to play an important role in the catalysis of HER. The observation in this work can provide new insights into the sulfurization process and the role of sulfide in the process of HER.

Renal cell carcinoma (RCC) has always been considered resistant to chemotherapy. IR-780 is a near-infrared fluorescent (NIRF) dye that can be efficiently taken up by RCC cells. Cabazitaxel is a cytotoxic drug that interferes with mitosis by acting on tubulin. We chemically fused IR-780 and cabazitaxel into a new drug, Caba-780, which is expected to increase the sensitivity of RCC to chemotherapy. Infrared spectrum, nuclear magnetic resonance spectra, high-resolution mass spectra, and IR spectra were used for detecting structural characterization of the new synthetic drug Caba-780. The RCC cells lines ACHN and 786-O, as well as the non-cancerous human embryonic kidney cell line HEK293, were used to assess the cytotoxicity and tumor-efficient uptake of Caba-780 in vitro. The xenograft tumor-bearing mice and C57 mice were used to estimate the tumor-efficient imaging of Caba-780 as well as the safety and efficacy of its anti-tumor effects in vivo. The new synthetic drug Caba-780 retains the NIRF properties of IR-780. In vitro, Caba-780 was efficiently absorbed by the RCC cell lines ACHN and 786-O, and had an inhibitory effect on their growth, clonogenicity migration, and invasion. At the same time, Caba-780 retained the anti-tumor effect of cabazitaxel, which can inhibit the growth of tumor cells and promote apoptosis by inhibiting mitosis. In vivo experiments showed that Caba-780 can be taken up and imaged in tumor tissue, whereby it inhibits tumor growth. The novel fused molecule Caba-780 has application prospects in the diagnosis and treatment of RCC and makes RCC chemotherapy possible.

Nobiletin is a polymethoxy flavonoid isolated from Citrus depressa and Citrus reticulata. It has been reported that nobiletin can suppress tumors. We primarily explored the antitumor effects of nobiletin and the associated potential mechanisms in ACHN and Caki-2 renal carcinoma cells. A CCK-8 assay and cloning experiments were used to assess cell viability, and a transwell assay and scratch test were used to assess metastatic ability. The cell cycle was analyzed by flow cytometry, whereas apoptosis was analyzed using flow cytometry and a terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay. Protein expression was examined by Western blot and immunofluorescence. Renal cancer cells were subcutaneously transplanted into nude mice for in vivo studies. The data showed that nobiletin administration significantly dose- and time-dependently suppressed renal cancer cell proliferation; moreover, nobiletin treatment induced cell cycle arrest in the G0/G1 phase and promoted apoptosis. Immunofluorescence analysis indicated that nobiletin decreased the nuclear localization of signal transducer and activator of transcription 3 (STAT3) and YY1-associated protein 1 (YY1AP1). Western blot showed that the levels of phosphorylated SRC, phosphorylated AKT serine/threonine kinase (AKT), and phosphorylated STAT3 were decreased, whereas that of phosphorylated YY1AP1 was increased. The results further showed that application of insulin-like growth factor 1 (IGF1) was able to reverse the nobiletin-induced changes in the levels of phosphorylated AKT, phosphorylated STAT3, and phosphorylated YY1AP1, and could also reverse the antitumor effects of nobiletin. The results of in vivo experiments showed that, compared to the control, tumor volume and weight were both reduced following nobiletin treatment. In conclusion, our study demonstrated that nobiletin can inhibit renal carcinoma cell viability and provides a novel therapeutic approach for the treatment of kidney cancer.

Amorphous materials have recently received much attention as catalysts for electrochemical reactions. However, there are relatively few reports focused on the structure change of amorphous catalyst...