Sulfur-Induced Growth of Coordination Polymer Derived-Straight Carbon Nanotubes on Carbon Nanofiber Network for Zn-Air Batteries.

Low-cost heteroatom-doped carbon nanomaterials have been widely studied for efficient oxygen reduction reaction and energy storage and conversion in metal-air batteries. A Masson pine twigs-like 3-dimensional network construction of carbon nanofibers (CNFs) with abundant straight long Co, N, and S-doped carbon nanotubes (CNTs) is developed by thermal treatment of Co-based polymer coated onto polyacrylonitrile nanofiber network together with thiourea at 900 °C, denoted as CNFT-Co9 S8 -900. It is interesting to note that the introduction of a high concentration of sulfur does not lead to the complete toxicity of catalysts, but promotes the axial growth to selectively form straight CNTs instead of curly bamboo-like CNTs. The highly graphitized in-situ grown Co, N, S-doped CNTs and the 3-dimensional N-doped CNF network provide both active catalytic sites and highly conductive paths, which are beneficial for oxygen reduction reaction (ORR). Thus, the optimal CNFT-Co9 S8 -900 performs the excellent ORR catalytic activity with a half-wave potential of 0.84 V and a diffusion-limited current density of 5.49 mA cm-2 . Furthermore, the CNFT-Co9 S8 -900-based Zn-air devices also possess a high power density of 136.9 mW cm-2 better than commercial Pt/C.

Synthesis and biological evaluation of novel N-(piperazin-1-yl)alkyl-1H-dibenzo[a,c]carbazole derivatives of dehydroabietic acid as potential MEK inhibitors.

In this paper, a series of novel 1H-dibenzo[a,c]carbazole derivatives of dehydroabietic acid bearing different N-(piperazin-1-yl)alkyl side chains were designed, synthesised and evaluated for their in vitro anticancer activities against three human hepatocarcinoma cell lines (SMMC-7721, HepG2 and Hep3B). Among them, compound 10g exhibited the most potent activity against three cancer cell lines with IC50 values of 1.39 ± 0.13, 0.51 ± 0.09 and 0.73 ± 0.08 µM, respectively. In the kinase inhibition assay, compound 10g could significantly inhibit MEK1 kinase activity with IC50 of 0.11 ± 0.02 µM, which was confirmed by western blot analysis and molecular docking study. In addition, compound 10g could elevate the intracellular ROS levels, decrease mitochondrial membrane potential, destroy the cell membrane integrity, and finally lead to the oncosis and apoptosis of HepG2 cells. Therefore, compound 10g could be a potent MEK inhibitor and a promising anticancer agent worthy of further investigations.

Synthesis and biological evaluation of 2-aryl-benzimidazole derivatives of dehydroabietic acid as novel tubulin polymerization inhibitors.

A series of novel 2-aryl-benzimidazole derivatives of dehydroabietic acid were synthesized and characterized by IR, 1H NMR, 13C NMR, MS and elemental analyses. All the target compounds were evaluated for their in vitro cytotoxic activity against SMMC-7721, MDA-MB-231, HeLa and CT-26 cancer cell lines and the normal hepatocyte cell line QSG-7701 through MTT assays. Among them, compound 6j displayed the most potent cytotoxic activity with IC50 values of 0.08 ± 0.01, 0.19 ± 0.04, 0.23 ± 0.05 and 0.42 ± 0.07 µM, respectively, and substantially reduced cytotoxicity against QSG-7701 cells (5.82 ± 0.38 µM). The treatment of SMMC-7721 cells with compound 6j led to considerable inhibition of cell migration ability. The influence of compound 6j on cell cycle distribution was assessed on SMMC-7721 cells, exhibiting a cell cycle arrest at the G2/M phase. Moreover, tubulin polymerization assays and immunofluorescence assays elucidated that compound 6j could significantly inhibit tubulin polymerization and disrupt the intracellular microtubule network. A molecular docking study provided insight into the binding mode of compound 6j in the colchicine site of tubulin. In addition, compound 6j was found to induce apoptosis of SMMC-7721 cells, an increase of intracellular ROS level and a loss of mitochondrial membrane potential in a dose-dependent manner. These findings provided new molecular scaffolds for the further development of novel antitumor agents targeting tubulin polymerization.

Synthesis and in vitro cytotoxic evaluation of new 1H-benzo[d]imidazole derivatives of dehydroabietic acid.

A series of new 1H-benzo[d]imidazole derivatives of dehydroabietic acid were designed and synthesized as potent antitumor agents. Structures of the target molecules were characterized using MS, IR, 1H NMR, 13C NMR and elemental analyses. In the in vitro cytotoxic assay, most compounds showed significant cytotoxic activities against two hepatocarcinoma cells (SMMC-7721 and HepG2) and reduced cytotoxicity against noncancerous human hepatocyte (LO2). Among them, compound 7b exhibited the best cytotoxicity against SMMC-7721 cells (IC50: 0.36±0.13µM), while 7e was most potent to HepG2 cells (IC50: 0.12±0.03µM). The cell cycle analysis indicated that compound 7b caused cell cycle arrest of SMMC-7721 cells at G2/M phase. Further, compound 7b also induced the apoptosis of SMMC-7721 cells in Annexin V-APC/7-AAD binding assay.

Renewable Lignosulfonate-Assisted Synthesis of Hierarchical Nanoflake-Array-Flower ZnO Nanomaterials in Mixed Solvents and Their Photocatalytic Performance.

With the assistance of sodium lignosulfonate, hierarchical nanoflake-array-flower nanostructure of ZnO has been fabricated by a facile precipitation method in mixed solvents. The sodium lignosulfonate amount used in our synthetic route is able to fine-tune ZnO morphology and an abundance of pores have been observed in the nanoflake-array-flower ZnO, which result in specific surface area reaching as high as 82.9 m(2) · g(-1). The synthesized ZnO exhibits superior photocatalytic activity even under low-power UV illumination (6 W). It is conjectured that both nanoflake-array structure and plenty of pores embedded in ZnO flakes may provide scaffold microenvironments to enhance photocatalytic activity. Additionally, this catalyst can be used repeatedly without a significant loss in photocatalytic activity. The low-cost, simple synthetic approach as well as high photocatalytic and recycling efficiency of our ZnO nanomaterials allows for application to treat wastewater containing organic pollutants in an effective way.

Synthesis, in vitro antimicrobial and cytotoxic activities of new carbazole derivatives of ursolic acid.

A series of new carbazole derivatives of ursolic acid were designed and synthesized in an attempt to develop potent antimicrobial or antitumor agents. Their structures were confirmed by using IR, HRMS and (1)H NMR analysis. All the synthesized compounds were evaluated for their antimicrobial activity against four bacterial and three fungal strains using serial dilution method. Compounds 3a, 3b, 4a, 4b and 5a-f exhibited significant antibacterial activity against at least one tested bacteria with MIC values of 3.9-15.6µg/ml. In addition, the in vitro cytotoxicity of these compounds were also assayed against two human tumor cell lines (SMMC-7721 and HepG2) using MTT colorimetric method. From the results, compounds 5a-e and 5h displayed pronounced cytotoxic activity with IC50 values below 10µM. Specially, compound 5e was found to be the most potent compound with IC50 values of 1.08±0.22 and 1.26±0.17µM against SMMC-7721 and HepG2 cells, respectively, comparable to those of doxorubicin. In addition, compound 5e showed reduced cytotoxicity against noncancerous LO2 cells with IC50 value of 5.75±0.48µM.

Synthesis and biological evaluation of novel N-substituted 1H-dibenzo[a,c]carbazole derivatives of dehydroabietic acid as potential antimicrobial agents.

A series of new N-substituted 1H-dibenzo[a,c]carbazole derivatives were synthesized from dehydroabietic acid, and their structures were characterized by IR, (1)H NMR and HRMS spectral data. All compounds were evaluated for their antibacterial and antifungal activities against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens) and three fungi (Candida albicans, Candida tropicalis and Aspergillus niger) by serial dilution technique. Some of the synthesized compounds displayed pronounced antimicrobial activity against tested strains with low MIC values ranging from 0.9 to 15.6µg/ml. Among them, compounds 6j and 6r exhibited potent inhibitory activity comparable to reference drugs amikacin and ketoconazole.

Low-temperature precipitation synthesis of flower-like ZnO with lignin amine and its optical properties.

A facile precipitation method has been developed to synthesize ZnO with [bis(2-aminoethyl)amino]methyl lignin (lignin amine) that is chemically modified from low-cost pulp industrial lignin. The obtained ZnO crystallites have been characterized to exhibit a hexagonal wurtzite structure, and their sizes have been determined at ca. 24 nm (mean value). These ZnO nanocrystallites are of high purity and well crystallized. Our present synthetic approach apparently exempts the commonly used calcining purification procedure. It is found that the morphology of ZnO and its specific surface area are capable of being tuned by varying the added lignin amine amount. Using the optimal 10 mL lignin amine, the synthesized ZnO exhibits flower-like morphology with proper specific surface area. Additionally, photoluminescence property of the obtainable ZnO displays two emissive bands at 383 nm (sharp) and in the range of 480 to 600 nm (broad) at room temperature. Their intensities were revealed to depend on the added lignin amine amount as well as on the molar ratio of Zn2+/OH-. The present investigation demonstrates that our method is simple, eco-friendly, and cost-effective for the synthesis of small-size ZnO materials.

Salegentibacter echinorum sp. nov., isolated from the sea urchin Hemicentrotus pulcherrimus.

A novel Gram-negative, strictly aerobic, heterotrophic, non-motile and yellow-pigmented bacterial strain, designated HD4(T), was isolated from the sea urchin Hemicentrotus pulcherrimus collected from the Yellow Sea in China. Optimal growth of the strain was observed at 28-30 °C, pH 6.8-7.3, and in the presence of 3-5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain HD4(T) exhibited high similarity with the members of Salegentibacter (92.3-95.4 %). The DNA G+C content was 37.0 mol%, MK-6 was the main respiratory quinone and summed feature 3 (comprising iso-C15:0 2-OH/C16:1ω7c), iso-C15:0, iso-C17:0 3-OH and anteiso-C15:0 were the major cellular fatty acids. The predominant polar lipids in strain HD4(T) were phosphatidylethanolamine and two unknown lipids (L2, L4). Based on the phylogenetic, physiological and biochemical characteristics, strain HD4(T) should be classified as a novel species within the genus Salegentibacter, for which the name Salegentibacter echinorum sp. nov. is proposed. The type strain is HD4(T) (=CICC 10466(T) = NRRL B-59666(T)).

Flaviflexus huanghaiensis gen. nov., sp. nov., an actinobacterium of the family Actinomycetaceae.

Strain H5(T) was isolated from a sediment sample collected from the coastal area of Qingdao, China. The cells were Gram-stain-positive, non-motile, straight or curved rods. The temperature range for growth was 20-37 °C and the pH for growth ranged from 6.5 to 9.0, with optimum growth occurring in the temperature range 28-30 °C and pH range 7.5-8.0. Growth occurred in the presence of 0-6% (w/v) NaCl (optimum, 0-2%). Strain H5(T) had MK-9, MK-9(H2) and MK-9(H4) as the major menaquinones and C18:1ω9c, C16:0, C14:0, C18:0 and C16:1ω9c as major fatty acids. The cell-wall peptidoglycan type was A5α l-Lys-l-Ala-l-Lys-d-Glu. The major polar lipids were phosphatidylglycerol (PG), an unknown phospholipid (PL1) and two unknown phosphoglycolipids (PGL1, PGL2). An unknown phospholipid (PL2) and two unknown glycolipids (GL1, GL2) were present in moderate to minor amounts in the polar lipid profile. The genomic DNA G+C content was 61.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain H5(T) represents a novel lineage in the family Actinomycetaceae. On the basis of phenotypic, physiological and molecular characteristics, it is proposed that the novel isolate should be classified as a novel species in a new genus: Flaviflexus huanghaiensis gen. nov., sp. nov., with strain H5(T) ( = DSM 24315(T) =CICC 10486(T)) as the type strain of the type species.

Neiella marina gen. nov., sp. nov., isolated from the sea cucumber Apostichopus japonicus.

A novel strain, designated J221(T), was isolated from the intestine of a sea cucumber, Apostichopus japonicus, collected from earthen ponds in Qingdao, China. The strain was Gram-negative, oxidase-positive, aerobic, rod-shaped and motile by means of one to several polar flagella. Growth of strain J221(T) was observed at temperatures between 10 and 40 °C with optimum growth between 25 and 28 °C. The pH range for growth was 5.0-9.0 with optimum growth at pH 7.5-8.0. The dominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c, 29.04 %), C16 : 0 (28.93 %) and C18 : 1ω7c (26.15 %). The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. Diphosphatidylglycerol, an unknown aminolipid and an unknown aminophospholipid were present in moderate to minor amounts in the polar lipid profile. Strain J221(T) had Q-8 as the major respiratory quinone. The DNA G+C content of strain J221(T) was 46.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain J221(T) is a member of the Gammaproteobacteria. It formed a distinct phyletic line with less than 91 % sequence similarity to any species within previously recognized genera. On the basis of this polyphasic taxonomic study, strain J221(T) should be classified as a representative of a novel species of a new genus, for which the name Neiella marina gen. nov., sp. nov. is proposed. The type strain of Neiella marina is J221(T) ( = CGMCC 1.10130(T) = NRRL B-51319(T)).

Agarivorans gilvus sp. nov. isolated from seaweed.

A novel agarase-producing, non-endospore-forming marine bacterium, WH0801(T), was isolated from a fresh seaweed sample collected from the coast of Weihai, China. Preliminary characterization based on 16S rRNA gene sequence analysis showed that WH0801(T) shared 96.1  % similarity with Agarivorans albus MKT 106(T), the type species of the genus Agarivorans. A polyphasic taxonomic study was conducted and confirmed the phylogenetic affiliation of strain WH0801(T) to the genus Agarivorans. Isolate WH0801(T) produces light-yellow-pigmented colonies; cells are Gram-stain-negative, straight or curved rods, which are motile with a single polar flagellum. Strain WH0801(T) grew in 0.5-5  % NaCl, with optimum growth at 3  % NaCl, and its optimal pH and cultivation temperature were 8.4-8.6 and 28-32 °C, respectively. Data from biochemical tests, whole-cell fatty acid profiling, 16S rRNA gene sequence studies and DNA-DNA hybridization clearly indicated that isolate WH0801(T) represented a novel species within the genus Agarivorans, for which the name Agarivorans gilvus sp. nov. is proposed. The type strain of Agarivorans gilvus sp. nov. is WH0801(T) (=NRRL B-59247(T) =CGMCC 1.10131(T)).

The study of helicon plasma source.

Helicon plasma source is known as efficient generator of uniform and high density plasma. A helicon plasma source was developed for investigation of plasma neutralization and plasma lens in the Institute of Modern Physics in China. In this paper, the characteristics of helicon plasma have been studied by using Langmuir four-probe and a high argon plasma density up to 3.9x10(13) cm(-3) have been achieved with the Nagoya type III antenna at the conditions of the magnetic intensity of 200 G, working gas pressure of 2.8x10(-3) Pa, and rf power of 1200 W with a frequency of 27.12 MHz. In the experiment, the important phenomena have been found: for a given magnetic induction intensity, the plasma density became greater with the increase in rf power and tended to saturation, and the helicon mode appeared at the rf power between 200 and 400 W.