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41.
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Vitaliy Chagovets Zhihao Wang Alexey Kononikhin Natalia Starodubtseva Anna Borisova Dinara Salimova Igor Popov Andrey Kozachenko Konstantin Chingin Huanwen Chen Vladimir Frankevich Leila Adamyan Gennady Sukhikh 《Journal of the American Society for Mass Spectrometry》2018,29(2):323-330
Recent research revealed that tissue spray mass spectrometry enables rapid molecular profiling of biological tissues, which is of great importance for the search of disease biomarkers as well as for online surgery control. However, the payback for the high speed of analysis in tissue spray analysis is the generally lower chemical sensitivity compared with the traditional approach based on the offline chemical extraction and electrospray ionization mass spectrometry detection. In this study, high resolution mass spectrometry analysis of endometrium tissues of different localizations obtained using direct tissue spray mass spectrometry in positive ion mode is compared with the results of electrospray ionization analysis of lipid extracts. Identified features in both cases belong to three lipid classes: phosphatidylcholines, phosphoethanolamines, and sphingomyelins. Lipids coverage is validated by hydrophilic interaction liquid chromatography with mass spectrometry of lipid extracts. Multivariate analysis of data from both methods reveals satisfactory differentiation of eutopic and ectopic endometrium tissues. Overall, our results indicate that the chemical information provided by tissue spray ionization is sufficient to allow differentiation of endometrial tissues by localization with similar reliability but higher speed than in the traditional approach relying on offline extraction. 相似文献
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Facile Separation,Spectroscopic Identification,and Electrochemical Properties of Higher Trifluoromethylated Derivatives of [70]Fullerene 下载免费PDF全文
Maria P. Kosaya Alexey V. Rybalchenko Dr. Natalia S. Lukonina Olga N. Mazaleva Dr. Ilya N. Ioffe Dr. Vitaliy Yu. Markov Prof. Dr. Sergey I. Troyanov Prof. Dr. Lev N. Sidorov Dr. Nadezhda B. Tamm Dr. Alexey A. Goryunkov 《化学:亚洲杂志》2018,13(15):1920-1931
We survey the structure and electronic properties of the family of higher trifluoromethylated C70(CF3)n molecules with n=14, 16, 18, and 20. Twenty‐two available compounds, of which thirteen are newly obtained and characterized, demonstrate the broad diversity of π‐system topologies, which enabled us to study the interplay between the CF3 addition pattern and the electronic properties. UV/Vis spectroscopic and cyclic voltammetric studies demonstrate the importance of the exact addition pattern rather than the plain number of addends. Of particular interest is the skew pentagonal pyramid (SPP) addition pattern, which enables formation of closed‐shell cyclopentadienyl anions C70(CF3)n? 1 ? through CF3 detachment upon electron transfer. A detailed study of the process is presented for a SPP‐C70(CF3)16 where potentiostatic electrolysis at the second reduction potential gives C70(CF3)15? oxidizable to a persistent C70(CF3)15· radical. Together with the literature data for the lower C70(CF3)n compounds with n=2–12, the present results show good correlation between the experimental boundary level positions and the DFT predictions. The compounds turn out to be electron acceptor molecular semiconductors with experimental LUMO energies and HOMO–LUMO gaps within the ranges of ?4.3 to ?3.7 eV and 1.6 to 3.3 eV, respectively, depending on the shape of the conjugated fragments. The HOMO levels fall within the range of ?5.6 to ?6.9 eV and show linear correlation with the number of addends. 相似文献
45.
High‐Pressure Synthesis of a Nitrogen‐Rich Inclusion Compound ReN8⋅x N2 with Conjugated Polymeric Nitrogen Chains 下载免费PDF全文
Dr. Maxim Bykov Dr. Elena Bykova Egor Koemets Timofey Fedotenko Georgios Aprilis Dr. Konstantin Glazyrin Dr. Hanns‐Peter Liermann Dr. Alena V. Ponomareva Johan Tidholm Dr. Ferenc Tasnádi Prof. Dr. Igor A. Abrikosov Prof. Dr. Natalia Dubrovinskaia Prof. Dr. Leonid Dubrovinsky 《Angewandte Chemie (International ed. in English)》2018,57(29):9048-9053
A nitrogen‐rich compound, ReN8?x N2, was synthesized by a direct reaction between rhenium and nitrogen at high pressure and high temperature in a laser‐heated diamond anvil cell. Single‐crystal X‐ray diffraction revealed that the crystal structure, which is based on the ReN8 framework, has rectangular‐shaped channels that accommodate nitrogen molecules. Thus, despite a very high synthesis pressure, exceeding 100 GPa, ReN8?x N2 is an inclusion compound. The amount of trapped nitrogen (x) depends on the synthesis conditions. The polydiazenediyl chains [?N=N?]∞ that constitute the framework have not been previously observed in any compound. Ab initio calculations on ReN8?x N2 provide strong support for the experimental results and conclusions. 相似文献
46.
Journal of Thermal Analysis and Calorimetry - The structural relaxation of Na2O–K2O–CaO–ZrO2–SiO2 (NKCZ), Na2O–K2O–ZnO–ZrO2–SiO2 (NKzZ),... 相似文献
47.
Stack the Bowls: Tailoring the Electronic Structure of Corannulene‐Integrated Crystalline Materials 下载免费PDF全文
Allison M. Rice Ekaterina A. Dolgopolova Brandon J. Yarbrough Gabrielle A. Leith Corey R. Martin Kenneth S. Stephenson Rebecca A. Heugh Amy J. Brandt Prof. Dr. Donna A. Chen Dr. Stavros G. Karakalos Dr. Mark D. Smith Prof. Dr. Kelsey B. Hatzell Dr. Perry J. Pellechia Prof. Dr. Sophya Garashchuk Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (International ed. in English)》2018,57(35):11310-11315
We report the first examples of purely organic donor–acceptor materials with integrated π‐bowls (πBs) that combine not only crystallinity and high surface areas but also exhibit tunable electronic properties, resulting in a four‐orders‐of‐magnitude conductivity enhancement in comparison with the parent framework. In addition to the first report of alkyne–azide cycloaddition utilized for corannulene immobilization in the solid state, we also probed the charge transfer rate within the Marcus theory as a function of mutual πB orientation for the first time, as well as shed light on the density of states near the Fermi edge. These studies could foreshadow new avenues for πB utilization for the development of optoelectronic devices or a route for highly efficient porous electrodes. 相似文献
48.
Victoria V. Grishko Natalia V. Galaiko Ekaterina V. Igosheva Maksim V. Dmitriev 《Tetrahedron》2018,74(34):4489-4494
A novel synthetic protocol of ozonolytic cleavage of 18α-oleanane triterpenoid with the five-membered α,β-alkenenitrile moiety dissolved in dichloromethane to selectively synthesize a 1,3-secotriterpene derivative with 78% yield was developed. Spontaneous condensations of the synthesized 19β,28-epoxy-1,3-seco-2-nor-18α-olean-3-al-1-oic acid followed by formation of unsubstituted 1,3- and 1,4-lactones were registered in reactions with sodium borohydride as a reducing reagent or oxalyl chloride as an activating agent, respectively. α-Methoxy- and α-ethoxy-substituted 1,3-lactones were obtained when the polar protic solvents methanol or ethanol were used for the ozonolysis of the alkenenitrile. Experiments on ozonolysis were carried out in combination with reduction with dimethyl sulfide. Ozonolysis of alkenenitrile in dichloromethane without reductive treatment was found out to have resulted in stable triterpene ozonide. 相似文献
49.
Summary Using the potentiometric method, the protonation constants of 1, 5- and 4, 6-benzo[h]naphthyridine (bn), as well as the stability constants of their complexes with nickel(II), cobalt(II), copper(II), or cadmium(II) were determined. 相似文献
50.