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Zhiwei Wang, Xianglin Li, Han Ling, Chiew Kei Tan, Loo Pin Yeo, Andrew Clive Grimsdale, Alfred Iing Yoong Tok
A 3D fluorine-doped SnO2 (FTO)/FTO-nanocrystal (NC)/TiO2 inverse opal (IO) structure is designed and fabricated as a new "host and guest" type of composite photoanode for efficient photoelectrochemical (PEC) water splitting. In this novel photoanode design, the highly conductive and porous FTO/FTO-NC IO acts as the "host" skeleton, which provides direct pathways for faster electron transport, while the conformally coated TiO2 layer acts as the "guest" absorber layer. The unique composite IO structure is fabricated through self-assembly of colloidal spheres template, a hydrothermal method and atomic layer deposition (ALD)...
April 17, 2018: Small
Lei Wang, Yueqing Wang, Mingguang Wu, Zengxi Wei, Chunyu Cui, Minglei Mao, Jintao Zhang, Xiaopeng Han, Quanhui Liu, Jianmin Ma
Zinc-air batteries with high-density energy are promising energy storage devices for the next generation of energy storage technologies. However, the battery performance is highly dependent on the efficiency of oxygen electrocatalyst in the air electrode. Herein, the N, F, and B ternary doped carbon fibers (TD-CFs) are prepared and exhibited higher catalytic properties via the efficient 4e- transfer mechanism for oxygen reduction in comparison with the single nitrogen doped CFs. More importantly, the primary and rechargeable Zn-air batteries using TD-CFs as air-cathode catalysts are constructed...
April 17, 2018: Small
Jialong Duan, Yuanyuan Zhao, Benlin He, Qunwei Tang
Perovskite solar cells with cost-effectiveness, high power conversion efficiency, and improved stability are promising solutions to the energy crisis and environmental pollution. However, a wide-bandgap inorganic-semiconductor electron-transporting layer such as TiO2 can harvest ultraviolet light to photodegrade perovskite halides, and the high cost of a state-of-the-art hole-transporting layer is an economic burden for commercialization. Here, the building of a simplified cesium lead bromide (CsPbBr3 ) perovskite solar cell with fluorine-doped tin oxide (FTO)/CsPbBr3 /carbon architecture by a multistep solution-processed deposition technology is demonstrated, achieving an efficiency as high as 4...
April 17, 2018: Small
Robert Wodtke, Christoph Hauser, Gloria Ruiz-Gomez, Elisabeth Jäckel, David Bauer, Martin Lohse, Alan Wong, Johanna Pufe, Friedrich-Alexander Ludwig, Steffen Fischer, Sandra Hauser, Dieter Greif, Maria Teresa Pisabarro, Jens Pietzsch, Markus Pietsch, Reik Löser
Transglutaminase 2 (TGase 2)-catalysed transamidation represents an important posttranslational mechanism for protein modification with implications in physiological and pathophysiological conditions including fibrotic and neoplastic processes. Consequently, this enzyme is considered a promising target for the diagnosis and therapy of these diseases. In this study, we report on the synthesis and kinetic characterisation of Nε -acryloyllysine piperazides as irreversible inhibitors of TGase 2. Systematic structural modifications on 54 new compounds were performed with a major focus on fluorine-bearing substituents due to the potential of such compounds to serve as radiotracer candidates for positron emission tomography...
April 17, 2018: Journal of Medicinal Chemistry
Alexander D Dilman, Vitalij V Levin
Compounds containing a difluoromethylene unit have gained increasing attention due to their utility in drug design. Classic methods for the synthesis of these compounds rely on either harsh deoxofluorination reactions or laborious functional group manipulation sequences. In 2013, we proposed a method for assembling gem-difluorinated molecules from a difluorocarbene, a nucleophile, and an electrophile. In this process, a difluorocarbene can be considered an equivalent of a bipolar CF2 unit. Performing consecutive bond-forming reactions by sequential attachment of a nucleophile and an electrophile to a difluorocarbene provides the opportunity for the synthesis of a wide variety of organofluorine compounds...
April 17, 2018: Accounts of Chemical Research
Kai Junge Puring, Dennis Zywitzki, Dereje H Taffa, Detlef Rogalla, Manuela Winter, Michael Wark, Anjana Devi
A series of six cobalt ketoiminates, of which one was previously reported but not explored as a chemical vapor deposition (CVD) precursor, namely, bis(4-(isopropylamino)pent-3-en-2-onato)cobalt(II) ([Co( i pki)2 ], 1), bis(4-(2-methoxyethylamino)pent-3-en-2-onato)cobalt(II) ([Co(meki)2 ], 2), bis(4-(2-ethoxyethylamino)pent-3-en-2-onato)cobalt(II) ([Co(eeki)2 ], 3), bis(4-(3-methoxy-propylamino)pent-3-en-2-onato)cobalt(II) ([Co(mpki)2 ], 4), bis(4-(3-ethoxypropylamino)pent-3-en-2-onato)cobalt(II) ([Co(epki)2 ], 5), and bis(4-(3-isopropoxypropylamino)pent-3-en-2-onato)cobalt(II) ([Co( i ppki)2 ], 6) were synthesized and thoroughly characterized...
April 17, 2018: Inorganic Chemistry
Antonio Togni, Carl Philipp Rosenau, Benson J Jelier, Alvar D Gossert
Fluorine chemistry has taken a pivotal role in chemical reaction discovery, drug development, and chemical biology. NMR spectroscopy, arguably the most important technique for characterization of fluorinated compounds, is rife with highly inconsistent referencing of fluorine NMR chemical shifts, producing deviations larger than 1 ppm. Herein, we provide unprecedented evidence that both spectrometer design and the current unified scale system underpinning the calibration of heteronuclear NMR spectra has unintentionally led to widespread variation in the standardization of 19F NMR spectral data...
April 16, 2018: Angewandte Chemie
Yoon-Hui Sung, David Eliezer
The Parkinson's protein alpha-synuclein binds to synaptic vesicles in vivo and adopts a highly extended helical conformation when binding to lipid vesicles in vitro. High-resolution structural analysis of alpha-synuclein bound to small lipid or detergent micelles revealed two helices connected by a non-helical linker, but corresponding studies of the vesicle-bound extended-helix state are hampered by the size and heterogeneity of the protein-vesicle complex. Here we employ fluorinated alcohols (FAs) to induce a highly helical aggregation-resistant state of alpha-synuclein in solution that resembles the vesicle-bound extended-helix state but is amenable to characterization using high-resolution solution-state NMR...
April 16, 2018: Protein Science: a Publication of the Protein Society
Emily Curnock, William Levason, Mark E Light, Sajinder K Luthra, Graeme McRobbie, Francesco M Monzittu, Gillian Reid, R Nathan Williams
Fluorination of [ScCl3(Me3-tacn)] (Me3-tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) and [ScCl3(BnMe2-tacn)] (BnMe2-tacn = 1,4-dimethyl-7-benzyl-1,4,7-triazacyclononane) by Cl/F exchange with 3 mol. equiv. of anhydrous [NMe4]F in CH3CN solution yields the corresponding [ScF3(R3-tacn)] (R3 = Me3 or BnMe2). These are the first examples of scandium fluoride complexes containing neutral co-ligands. The fluorination occurs stepwise, and using a deficit of [NMe4]F produced [ScF2Cl(Me3-tacn)]. Attempts to fluorinate [YCl3(Me3-tacn)], [YI3(Me3-tacn)], [LaCl3(Me3-tacn)(OH2)] or [MCl3(terpy)] (M = Sc, Y or La; terpy = 2,2':6'2''-terpyridyl) using a similar method were unsuccessful, due to the Cl/F exchange being accompanied by loss of the neutral ligand from the metal centre...
April 17, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Zoltán Novák, Ádám Mészáros, Anna Székely, András Stirling
Synthesis of fluorinated compounds and their use as pharmaceutical ingredients or synthetic building blocks are in the focus of chemical and medicinal research. However, the efficient synthesis of trifluoromethylated nitrogen heterocycles sometimes are challenging. Herein, we disclose a simple aziridination process which relies on the use of amines and novel alkenyl synthon for the access of trifluoromethylated strained heterocycle. With the utilization of a newly designed, bench stable but highly reactive hypervalent alkenyl iodonium species, the three membered heterocyclic ring can be constructed from simple amines without structural limitation with high efficiency under mild conditions in the absence of transition metal catalysts...
April 16, 2018: Angewandte Chemie
Viktoria Butsch, Frederik Börgel, Fabian Galla, Katrin Schwegmann, Sven Hermann, Michael Schäfers, Burkhard Riemann, Bernhard Wünsch, Stefan Wagner
Dysregulated levels of activated matrix metalloproteinases (MMPs) are linked to different pathologies such as cancer, atherosclerosis, neuroinflammation and arthritis. Therefore imaging of MMPs with positron emission tomography (PET) represents a powerful tool for the diagnosis of MMP associated diseases. Moreover, to distinguish between the distinct functions and roles of individual MMPs in particular pathophysiological processes their specific imaging must be realized with radiolabeled tracers e.g. fluorine-18 labeled MMP inhibitors (MMPIs)...
April 16, 2018: Journal of Medicinal Chemistry
Samantha E Wilner, Qi Xiao, Zachary Tobias Graber, Samuel E Sherman, Virgil Percec, Tobias Baumgart
Lamellar to non-lamellar membrane shape transitions play essential roles in key cellular processes, such as membrane fusion and fission, and occur in response to external stimuli, including drug treatment and heat. A subset of these transitions can be modeled by means of thermally inducible amphiphile assemblies. We previously reported on mixtures of hydrogenated, fluorinated, and hybrid Janus dendrimers (JDs) that self-assemble into complex dendrimersomes (DMSs), including dumbbells, and serve as promising models for understanding the complexity of biological membranes...
April 16, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Sebastian Hagenhoff, Ansgar Korf, Ullrich Markgraf, Sebastian Brandt, Alexander Schütz, Joachim Franzke, Heiko Hayen
RATIONALE: The potential of an atmospheric pressure ionization source based on a dielectric barrier discharge in helium for the hyphenation of gas chromatography and mass spectrometry (GC/DBDI-MS) has been demonstrated only recently and for a limited range of compounds. Due to its 'soft' ionization properties and the possibility to choose from a variety of atmospheric pressure ionization MS instruments, GC/DBDI-MS has the potential to be an interesting alternative to 'classic' GC/MS techniques...
April 16, 2018: Rapid Communications in Mass Spectrometry: RCM
Yanna Liu, Manli Qian, Xinxin Ma, Lingyan Zhu, Jonathan W Martin
Non-target high resolution mass spectrometry (Nt-HRMS) has proven useful for identification of unknown poly- and perfluoroalkyl substances (PFASs) in commercial products and water, but applications to biological samples are limited. China is the major PFAS manufacturing nation, thus here we adapted our Nt-HRMS methods to fish collected from Yangtze River and Tangxun Lake to discover potentially bioaccumulative PFASs in aquatic organisms destined for human consumption. In addition to traditional PFASs, over 330 other fluorinated analytes belonging to 10 classes of PFASs were detected among the pooled fish livers, including 6 sulfonate classes, 2 amine classes, 1 carboxylate class, and 1 N-heterocycle class...
April 16, 2018: Environmental Science & Technology
Teera Butburee, Yang Bai, Huanjun Wang, Hongjun Chen, Zhiliang Wang, Gang Liu, Jin Zou, Pongtanawat Khemthong, Gao Qing Max Lu, Lianzhou Wang
Porous single crystals are promising candidates for solar fuel production owing to their long range charge diffusion length, structural coherence, and sufficient reactive sites. Here, a simple template-free method of growing a selectively branched, 2D anatase TiO2 porous single crystalline nanostructure (PSN) on fluorine-doped tin oxide substrate is demonstrated. An innovative ion exchange-induced pore-forming process is designed to successfully create high porosity in the single-crystalline nanostructure with retention of excellent charge mobility and no detriment to crystal structure...
April 16, 2018: Advanced Materials
Satoshi Yamauchi, Yasuka Yamashita, Asuka Nishimoto, Hisashi Nishiwaki
The relationship between the structure of lignano-9,9'-lactone (2,3-dibenzylbutyrolactone) and its activity as a plant growth regulator was clarified. Derivatives with higher plant growth inhibitory activity than natural dimethylmatairesinol 4 were synthesized. The 2-hydroxy-7-Z-ene derivative 42 displayed growth inhibitory activity against both the shoots (IC50 = 0.65 mM) and roots (IC50 = 0.43 mM) of lettuce seedlings. Regiospecific activity was observed. The 2,3-dihydroxy derivative 24 showed the highest growth inhibitory activity against both the shoots (IC50 = 0...
April 16, 2018: Journal of Agricultural and Food Chemistry
Xin Zhang, Fei Liu, Karla-Anne Knapp, Michael L Nickels, H Charles Manning, Leon M Bellan
Herein, we report the development of a simple, high-throughput and efficient microfluidic system for synthesizing radioactive [18F]fallypride, a PET imaging radiotracer widely used in medical research. The microfluidic chip contains all essential modules required for the synthesis and purification of radioactive fallypride. The radiochemical yield of the tracer is sufficient for multiple animal injections for preclinical imaging studies. To produce the on-chip concentration and purification columns, we employ a simple "trapping" mechanism by inserting rows of square pillars with predefined gaps near the outlet of microchannel...
April 16, 2018: Lab on a Chip
Adel S Girgis, Altaf H Basta, Houssni El-Saied, Mohamed A Mohamed, Ahmad H Bedair, Ahmad S Salim
A variety of fluorescence-active fluorinated pyrazolines 13-33 was synthesized in good yields through cyclocondensation reaction of propenones 1-9 with aryl hydrazines 10-12 . Some of the synthesized compounds provided promising fluorescence properties with quantum yield ( Φ ) higher than that of quinine sulfate (standard reference). Quantitative structure-property relationship studies were undertaken supporting the exhibited fluorescence properties and estimating the parameters governing properties. Five synthesized fluorescence-active pyrazolines ( 13 , 15 , 18 , 19 and 23 ) with variable Φ were selected for treating two types of paper sheets (Fabriano and Bible paper)...
March 2018: Royal Society Open Science
Dorleta Gonzalez, Raquel L Arribas, Lucia Viejo, Rocio Lajarin-Cuesta, Cristobal de Los Rios
Following the premises of the multitarget-directed ligands approach for the drug R&D against neurodegenerative diseases, where Alzheimer's disease (AD) outstands, we have synthesized and evaluated analogues of the gramine derivative ITH12657 (1-benzyl-5-methyl-3-(piperidin-1-ylmethyl-1H-indole, 2), which had shown important neuroprotective properties, such as blocking effect of voltage-gated Ca2+ channels (VGCC), and prevention of phosphoprotein phosphatase 2A (PP2A) inhibition. The new analogues present different substitutions at the pending phenyl ring, what slightly modified their pharmacological characteristics...
April 9, 2018: Bioorganic & Medicinal Chemistry
Norimitsu Kasahara, Kyoichi Kaira, Pinjie Bao, Tetsuya Higuchi, Yukiko Arisaka, Bilguun Erkhem-Ochir, Noriaki Sunaga, Yoichi Ohtaki, Toshiki Yajima, Takayuki Kosaka, Tetsunari Oyama, Takehiko Yokobori, Takayuki Asao, Masahiko Nishiyama, Yoshito Tsushima, Hiroyuki Kuwano, Kimihiro Shimizu, Akira Mogi
OBJECTIVES: 2-Deoxy-2-[fluorine-18] fluoro-d-glucose with positron emission tomography (18 F-FDG-PET) is a clinically useful tool for cancer evaluation. 18 F-FDG accumulation in tumor cells is known to be correlated with the presence of glucose transporter 1 (GLUT1) and hypoxia-inducible factor-1α (HIF-1α). Although anti-programmed death-1 (PD-1) antibody treatments have been approved, no suitable predictor of significant responders has been identified. Based on the existing information, we investigated the relationship between tumor immunity (including PD-L1) and 18 F-FDG uptake in patients with surgically resected pulmonary squamous-cell carcinoma (SQC)...
May 2018: Lung Cancer: Journal of the International Association for the Study of Lung Cancer
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