bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfur‐Annulated Hexa‐peri‐hexabenzocoronene Decorated with Phenylthio Groups at the Periphery
Authors: Tan Yuan‐Zhi , Osella Silvio , Liu Yi , Yang Bo , Beljonne David , Feng Xinliang , Müllen Klaus 
Published: January 2015

AbstractThe chemical nature of the edge periphery essentially determines the physical properties of graphene. As a molecular‐level model system, large polycyclic aromatic hydrocarbons, that is, so‐called nanographenes, can be chemically modified through either edge functionalization or doping with heteroatoms. Although the synthetic methods for edge substitution are well‐developed, incorporation with heteroatoms by the bay annulation of large PAHs remains an enormous challenge. In this study, we present a feasible peripheral sulfur annulation of hexa‐peri‐hexabenzocoronene (HBC) by thiolation of perchlorinated HBC. The tri‐sulfur‐annulated HBC and di‐sulfur‐annulated HBC decorated with phenylthio groups were obtained and characterized by X‐ray diffraction, revealing their distinct sulfur‐annulated peripheral structure. Associated with theoretical calculations, we propose that the regioselective sulfur annulation results from the minimization of strain in the aromatic backbone. We further demonstrate the structure‐correlated property modulation by sulfur annulation, manifested by a decrease in band gap and tunable redox activity.
Total Synthesis of (−)‐Caprazamycin A
Authors: Nakamura Hugh , Tsukano Chihiro , Yasui Motohiro , Yokouchi Shinsuke , Igarashi Masayuki , Takemoto Yoshiji 
Published: January 2015

AbstractCaprazamycin A has significant antibacterial activity against Mycobacterium tuberculosis (TB). The first total synthesis is herein reported and features a) the scalable preparation of the syn‐β‐hydroxy amino acid with a thiourea‐catalyzed diastereoselective aldol reaction, b) construction of a diazepanone with an unstable fatty‐acid side chain, and c) global deprotection with hydrogenation. This report provides a route for the synthesis of related liponucleoside antibiotics with fatty‐acid side chains.
Acceleration of Acetal Hydrolysis by Remote Alkoxy Groups: Evidence for Electrostatic Effects on the Formation of Oxocarbenium Ions
Authors: Garcia Angie , Otte Douglas A. L. , Salamant Walter A. , Sanzone Jillian R. , Woerpel K. A. 
Published: January 2015

AbstractIn contrast to observations with carbohydrates, experiments with 4‐alkoxy‐substituted acetals indicate that an alkoxy group can accelerate acetal hydrolysis by up to 20‐fold compared to substrates without an alkoxy group. The acceleration of ionization in more flexible acetals can be up to 200‐fold when compensated for inductive effects.
Palladium(0)‐Catalyzed Iminohalogenation of Alkenes: Synthesis of 2‐Halomethyl Dihydropyrroles and Mechanistic Insights into the Alkyl Halide Bond Formation
Authors: Chen Chen , Hou Longlei , Cheng Mian , Su Jianhua , Tong Xiaofeng 
Published: January 2015

AbstractAlthough the advances on carbon halide reductive elimination have been made, the alkyl bromide and chloride analogues remain a challenge. Here, a palladium(0)‐catalyzed iminohalogenation of γ,δ‐unsaturated oxime esters is described, and the use of electron‐poor phosphine ligands proved to be crucial to promoting alkyl bromide and chloride reductive elimination. Furthermore, SN2‐type alkyl bromide and chloride reductive elimination has also been established.
Micromixing enhancement in a novel passive mixer with symmetrical cylindrical grooves
Authors: Wang Lei , Ma Shenghua , Han Xiaojun 
Published: January 2015

AbstractA passive micromixer with symmetrical cylindrical grooves along the channel was designed, fabricated and characterized. Systematic numerical simulations of mixing with Re ranging from 1.0 to 500 predict the optimized parameters and the mixing enhancement. The optimized depth of the cylindrical grooves is 100 µm. The experimental results have also confirmed the improvement of the mixing effect. Considering pressure drop and mixing enhancement, Re values of 10 and 100 are suitable for mixing of liquids with diffusion coefficients of 10−9 and 6 × 10−11 m2/s, respectively. The percentage of mixing of this micromixer is 2.22‐fold better than that of common Y‐mixer with Re of 10 at the distance of 19 mm from the meeting point of two fluids with the diffusion coefficient of 10−9 m2/s; similarly, the percentage of mixing of the new design is 2.18 times better than that of common Y‐mixer with Re of 100 at the distance of 19 mm from the meeting point of two fluids with the diffusion coefficient of 6 × 10−11 m2/s. This easy fabricated micromixer can be utilized for biological reactions and analytical assays. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Ultrafiltration of aquatic humic substances through magnetically responsive polysulfone membranes
Authors: Azmi Nur Atiah , Ng Qi Hwa , Low Siew Chun 
Published: January 2015

ABSTRACTOrganic foulants, such as humic acid substances, contribute to the irreversible fouling and flux decline in membrane separation processes. To reduce the membrane fouling potential, in this study, we explored the end‐capping of functionalized nanostructured magnetite (Fe3O4) with poly(acrylic acid) (PAA) on the surface of the polysulfone (PSF) membrane. The binding stability of PAA‐functionalized Fe3O4 [functionalized magnetite‐responsive nanoparticles (F‐MNPs)], combined with field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometry, were studied to determine the deposited morphology and magnetic properties of F‐MNPs on the membrane surface. In addition, the fouling analysis of the modified (F‐MNPs‐PSF) and unmodified (PSF) membranes were also being investigated through the filtration study. The results show that the magnetically responsive F‐MNPs‐PSF membrane developed in this study achieved high efficiency for the removal of humic substances when they were exposed to an oscillating external magnetic field. During filtration, the external magnetic field indirectly generated a torque that twisted the deposited Fe3O4 on the membrane surface. The actuated iron oxides consecutively reduced the concentration polarization around the top surface of the membrane and sequentially reduced the fouling propensity. These results provide some insight into the membrane's antifouling stability, which could be useful for environmental remediation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41874.
Cellulose‐based filter aids increase the capacity of depth filters during the downstream processing of plant‐derived biopharmaceutical proteins
Authors: Buyel Johannes Felix , Opdensteinen Patrick , Fischer Rainer 
Published: January 2015

AbstractDownstream processing (DSP) is a major cost factor during the production of biopharmaceutical proteins. Clarification can account for ∼40% of these costs, especially when a large amount of dispersed particulate material is generated, such as during the extraction of intracellular proteins from plants. Filter capacity can be increased (and DSP costs reduced) by using flocculants. Here we show that cellulose‐based filter aids can enhance the positive effect of flocculants by improving depth filter capacity even further. A design‐of‐experiments (DoE) approach was used to identify the optimal size and concentration of filter aids, at different values of pH and conductivity, for the clarification of tobacco leaf extracts during the production of a monoclonal antibody and a fluorescent protein. Filter aids ∼28 or ∼100 μm in length at concentrations of ∼10 and ∼5 g L–1 respectively were most efficient in combination with a strong cationic flocculant, but were ineffective without the flocculant. The filter aids increased depth filter capacity by 35‐fold compared to an additive‐free extract reaching ∼1000 L m–2 without affecting the target proteins. Thus, filter aids can be used to reduce production costs of plant‐derived biopharmaceuticals while the DoE approach enabled the identification of robust process conditions.
New analytical method for the study of metabolism of swertiamarin in rats after oral administration by UPLC‐TOF‐MS following DNPH derivatization
Authors: Wu Xiuhong , Tang Shuhan , Jin Yan , Zhang Yan , Hattori Masao , Wang Xijun , Zhang Hailong , Wang Zhigang 
Published: January 2015

AbstractThe metabolism of swertiamarin in vivo was studied by LC‐MS following 2,4‐dinitrophenylhydrazine derivatization. The ionization efficiency of the main metabolite erythrocentaurin was greatly enhanced by the new analytical method developed, and erythrocentaurin was successfully detected for the first time in rat plasma after oral administration of swertiamarin. Methyl 4‐formylbenzoate was used as the internal standard to quantify erythrocentaurin in rat plasma in negative mode by UPLC‐TOF‐MS, and it was found that erythrocentaurin reached the maximum mean plasma concentration of 425.8 ± 127.6 ng/mL at about 2 h after oral administration of swertiamarin at a dose of 200 mg/kg. A metabolic pathway of swertiamarin to erythrocentaurin was proposed. Swertiamarin is first hydrolyzed by bacterial β‐glucusidase to give the aglycone, which is readily converted to erythrocentaurin. The monoterpene compound swertiamarin was found to be metabolized to dihydroisocoumarin and alkaloid compounds in vivo, which may be responsible for the pharmacological effect of swertiamarin. The results may shed light on the clinical efficacy of swertiamarin and the new analytical method may assist in studies for the metabolism of other natural iridoids and secoiridoids in vivo. Copyright © 2015 John Wiley & Sons, Ltd.
Organocatalytic Enantioselective Decarboxylative Reaction of Malonic Acid Half Thioesters with Cyclic N‐Sulfonyl Ketimines by Using N‐Heteroarenesulfonyl Cinchona Alkaloid Amides
Authors: Nakamura Shuichi , Sano Masahide , Toda Ayaka , Nakane Daisuke , Masuda Hideki 
Published: January 2015

AbstractThe organocatalytic enantioselective decarboxylative Mannich reaction of malonic acid half thioesters (MAHTs) with cyclic N‐sulfonyl ketimines by using N‐heteroarenesulfonyl cinchona alkaloid amides afforded products with high enantioselectivity. Both enantiomers of the products could be obtained by using pseudoenantiomeric chiral catalysts. The reaction proceeds through a nucleophilic addition of the MAHTs to the ketimines prior to decarboxylation.
Characterization of a unique cell population marked by transgene expression in the adult cochlea of nestin‐CreERT2/tdTomato‐reporter mice
Authors: Chow Cynthia L. , Guo Weixiang , Trivedi Parul , Zhao Xinyu , Gubbels Samuel P. 
Published: January 2015

ABSTRACTHair cells in the adult mammalian cochlea cannot spontaneously regenerate after damage, resulting in the permanency of hearing loss. Stem cells have been found to be present in the cochlea of young rodents; however, there has been little evidence for their existence into adulthood. We used nestin‐CreERT2/tdTomato‐reporter mice to trace the lineage of putative nestin‐expressing cells and their progeny in the cochleae of adult mice. Nestin, an intermediate filament found in neural progenitor cells during early development and adulthood, is regarded as a multipotent and neural stem cell marker. Other investigators have reported its presence in postnatal and young adult rodents; however, there are discrepancies among these reports. Using lineage tracing, we documented a robust population of tdTomato‐expressing cells and evaluated these cells at a series of adult time points. Upon activation of the nestin promoter, tdTomato was observed just below and medial to the inner hair cell layer. All cells colocalized with the stem cell and cochlear‐supporting‐cell marker Sox2 as well as the supporting cell and Schwann cell marker Sox10; however, they did not colocalize with the Schwann cell marker Krox20, spiral ganglion marker NF200, nor glial fibrillary acidic acid (GFAP)‐expressing supporting cell marker. The cellular identity of this unique population of tdTomato‐expressing cells in the adult cochlea of nestin‐CreERT2/tdTomato mice remains unclear; however, these cells may represent a type of supporting cell on the neural aspect of the inner hair cell layer. J. Comp. Neurol. 523:1474–1487, 2015. © 2015 Wiley Periodicals, Inc.
Controlling Porosity in Lignin‐Derived Nanoporous Carbon for Supercapacitor Applications
Authors: Jeon Ju‐Won , Zhang Libing , Lutkenhaus Jodie L. , Laskar Dhrubojyoti D. , Lemmon John P. , Choi Daiwon , Nandasiri Manjula I. , Hashmi Ali , Xu Jie , Motkuri Radha K. , Fernandez Carlos A. , Liu Jian , Tucker Melvin P. , McGrail Peter B. , Yang Bin , Nune Satish K. 
Published: January 2015

AbstractInvited for this month′s cover is a group of collaborators led by Satish Nune at Pacific Northwest National Laboratory. The image shows the path to renewable energy storage using high surface area carbons derived from low‐cost renewable lignin. The Communication itself is available at 10.1002/cssc.201402621.
Headspace oxygen measurements can be used as a fast and convenient method for shelf‐life assessment of potato snacks
Authors: Samotyja Urszula , Kozak Wojciech 
Published: January 2015

The aim of this study was to explore the influence of different barrier and atmosphere conditions on the complex processes affecting storage stability of potato snacks, and the use of oxygen determination measurements within a packaging atmosphere as a quick quality and shelf‐life assessment method. The subject of investigation was potato snacks packed in transparent and metallised polymeric packaging laminates, filled with air or nitrogen. Samples were analysed for moisture, water activity, hydroperoxide and oxygen concentration in the headspace by two methods: a non‐invasive optical method based on fluorescence quenching and an electrochemical method. High barrier packaging provides better protection against moisture but not against oxidation. The shelf‐life of potato snacks is undermined by oxygen presence in the foam structure of the product. Neither barrier packaging nor modification of atmosphere applied alone bring satisfactory results, therefore a combined strategy is recommended. The study proved that the most optimal solution was the use of metallised packaging with nitrogen. The use of an optical sensor can be an appropriate and effective novel method for a non‐destructive oxidation progress evaluation of food that is stored in translucent packaging.Practical applications: The high linear correlation between hydroperoxides and oxygen content is of great practical value in shelf‐life assessment and screening the correctness of a packaging process.The shelf‐life of potato snacks is undermined by oxidative processes. As processes of fatty acids oxidation are related to oxygen uptake, the presence of a relationship between hydroperoxide content and oxygen concentration or consumption is of great practical value in quality and shelf‐life assessment.
Cooking and pressing is an effective and eco‐friendly technique for obtaining high quality oil from Sardinella longiceps
Authors: Chakraborty Kajal , Joseph Deepu 
Published: January 2015

The conventional Bligh and Dyer method of extracting oil from the edible tissues of Sardinella longiceps was compared with different eco‐friendly methodologies using 40% ethanol, 95% ethanol, distilled water, and cooking followed by pressing, as well as cooking followed by the Bligh and Dyer method. Among the different methods studied, cooking followed by pressing showed a beneficial effect on the quality of the oil as evidenced by reduced saponification (209.8 mg KOH/g), peroxide (11.88 meqO­2/kg), para‐anisidine (16.2), total oxidation (39.96), and TBARS (6.18 MDAEQ/kg) values. A comparable lipid yield (8.3%) with that of the Bligh and Dyer method was attained through the cooking and pressing method. The greater induction time (0.13 h) indicated better oxidative stability of cooked and pressed oil as compared to the oil obtained using other methods. The fish oil obtained by cooking followed by pressing has been demonstrated to yield comparable amounts of eicosapentaenoic acid, docosahexaenoic acid, and total polyunsaturated fatty acid contents when compared to the Bligh and Dyer method. These results demonstrated the effectiveness of the cooking and pressing technique for obtaining the best quality oil from Sardinella longiceps. The oil obtained by the cooking and pressing mode was characterized by FTIR and NMR experiments.Practical applications: The advantages of the method involving cooking followed by pressing as compared to the traditional Bligh and Dyer method were the absence of toxic solvents along with reduced cost and labor requirements. In addition, no chemical wastes were generated in this technique. The cooking followed by pressing method has been demonstrated to improve the nutritive value and oxidative stability of the crude fish oil as compared to the new eco‐friendly methods studied and the traditional method. The utilities of FTIR and NMR analyses as new analytical tools for analyzing the chemistry of fish oil have been demonstrated in the present study. This study is significant for the extraction of greater quality marine fish oil for use in pharmaceutical industries.Oil obtained by cooking followed by pressing (E6) of Sardinella longiceps showed greater induction time (0.13 h) compared to the conventional Bligh and Dyer method (E1, 0.05 h). No significant differences in EPA, DHA, total n‐3 PUFA, or n‐3/n‐6 PUFA contents were observed between E6 and E1. The signature peaks of different fatty acids of E6 were identified from the 1H‐NMR spectral features. These results demonstrated the effectiveness of cooking and pressing technique for obtaining the best quality oil from S. longiceps.
Variations in the Blaise Reaction: Conceptually New Synthesis of 3‐Amino Enones and 1,3‐Diketones
Authors: Rao H. Surya Prakash , Muthanna Nandurka 
Published: January 2015

AbstractOrganic compounds with 3‐amino enone or 1,3‐diketone functional groups are extremely important, as they can be converted into a plethora of heterocyclic or carbocyclic compounds, or can be used as ligands in metal complexes. We have achieved a new, easy, straightforward and convenient synthesis of 3‐amino enones and 1,3‐diketones starting from aryl/heteroaryl/alkyl nitriles and 1‐aryl/alkyl 2‐bromoethanones. The reaction is a variation of the classical Blaise reaction, and it works with zinc and trimethylsilyl chloride as an activator. By running the hydrolysis of the reaction intermediate with HCl (3 n aq.) at 0–30 °C or at 100 °C, it is possible to form either 3‐amino enones or 1,3‐diketones, respectively. The newly developed method was used for the synthesis of avobenzone, an ingredient of sun‐screen lotions. Furthermore, an easy synthesis of (Z)‐3‐amino‐1‐[4‐(tert‐butyl)phenyl]‐3‐(4‐methoxyphenyl)prop‐2‐en‐1‐one, with UV/Vis absorption characteristics similar to those of avobenzone, was also achieved.
Synthesis of Substituted Dibenz[a,c]anthracenes and an Investigation of Their Liquid‐Crystalline Properties
Authors: Psutka Katie M. , Williams Joshua , Paquette Joseph A. , Calderon Oliver , Bozek Kevin J. A. , Williams Vance E. , Maly Kenneth E. 
Published: January 2015

AbstractWe report the synthesis of a series of 2,3,5,6‐tetraalkoxydibenz[a,c]anthracenes bearing substituents (H, OCH3, or CN) in the 11‐ and 12‐positions and an investigation of their liquid‐crystalline properties. The synthesis involved Suzuki coupling of the appropriate dibromonaphthalene and boronate ester, followed by an oxidative cyclization. Compounds 4 and 5, bearing OCH3 and H, respectively, do not exhibit any liquid‐crystalline properties. In contrast, compounds 6a–c, bearing cyano groups, assemble into columnar mesophases, suggesting that electron‐withdrawing groups are important for promoting columnar mesophase assembly. Analysis of the XRD revealed that compound 6b exhibits a columnar hexagonal phase, whereas compounds 6a and 6c exhibit columnar rectangular phases. The XRD data of 6a and 6b also show reflections that are consistent with antiparallel dimers within the columnar stacks, and intercolumnar spacings suggest that molecules are tilted within the columns.
Copper‐Catalyzed Asymmetric Oxidative Cross‐Coupling of 2‐Naphthols with Aryl Methyl Ketones
Authors: Deng Tao , Wang Hongjun , Cai Chun 
Published: January 2015

AbstractA copper‐catalyzed asymmetric oxidative cross‐coupling reaction of 2‐naphthols with aryl methyl ketones has been developed. This transformation provides an efficient route to various functionalized naphtho[2,1‐b]furan‐1(2H)‐ones in an enantiomerically enriched manner with molecular oxygen in air as the oxidant (52–89 % yields, up to 87 % ee). The reaction leads to the formation of a new quaternary carbon center within 3(2H)‐furanones.
Efficient Microwave‐Assisted Synthesis of PCBM Methanofullerenes (C60 and C70)
Authors: Hadad Caroline , Syrgiannis Zois , Bonasera Aurelio , Prato Maurizio 
Published: January 2015

AbstractPCBM is a fullerene derivative (phenyl‐C61‐butyric acid methyl ester) considered to be one of the best n‐type organic semiconductors and plays a relevant role in organic photovoltaic solar cells. Much effort has been devoted to the optimization of the synthesis of PCBM derivatives. In this paper, PC61BM and PC71BM fullerene mono‐adducts but also PCBM‐like derivatives are successfully prepared by a one‐step cyclopropanation reaction under microwave irradiation. The products are collected in good yields in short time, during which isomerization of the open [5,6] to the closed [6,6] form takes place in situ. In addition, with the use of two cycles of irradiation, a series of mixtures of bis‐adduct PCBM‐like derivatives were also obtained in good yields.
An Antibacterial Nonenzymatic Glucose Sensor Composed of Carbon Nanotubes Decorated with Silver Nanoparticles
Authors: Liu Yingzhu , Liu Shan , Chen Rongsheng , Zhan Weiting , Ni Hongwei , Liang Feng 
Published: January 2015

AbstractA glucose sensor composed of silver nanoparticles decorated carbon nanotubes (Ag‐NPs/CNTs) prepared by ion implantation is described. Ag‐NPs with size of 2–4 nm are uniformly distributed in the CNTs after ion implantation. This process provides a strong combination between Ag‐NPs and CNTs and can effectively prevent the Ag‐NPs from aggregation. A linear range of 125 µM to 10 mM towards glucose determination was obtained. The Ag‐NPs/CNTs electrode shows minimal interferences from co‐existence species such as uric acid and ascorbic acid and an antibacterial rate of 94 % towards E. coli.
Nanohybrid Chemosensor for the Simultaneous Detection of Fluoride and Iodide in Aqueous System and Its Utility in Real Samples
Authors: Huerta‐Aguilar Carlos Alberto , Singh Jasminder , Kaur Harpreet , Pandiyan Thangarasu , Singh Narinder 
Published: January 2015

AbstractA nanohybrid chemosensor for specific, selective and simultaneous recognition of iodide and fluoride was prepared through decoration of silver nanoparticles onto Schiff‐Base based organic nanoparticles. The developed chemosensor showed specific recognition ability for this analytes at low concentrations with detection limits at 690 nM for fluoride and 11 nM for iodide in two different regions of DPV profiles. Theoretical calculations based in Density Functional Theory were performed, which supports experimental results by demonstrating the binding selectivity of nanohybrids with I− and F−. The proposed sensor was also used for real sample analysis and results were verified using some standard literature method.