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51.
It is shown to be consistent that countable, Fréchet,
1-spaces are first countable. The result is obtained by using a countable support iteration of proper partial orders of length
2.The research of both authors is partially supported by NSERC 相似文献
52.
Alan R. Katritzky Subbu Perumal Wojciech Kuzmierkiewicz Ping Lue John V. Greenhill 《Helvetica chimica acta》1991,74(8):1924-1930
tert- Alkyl sulfides are conveniently prepared from α-(1H-benzotriazol-1-yl)alkyl sulfides by displacement of the 1H-benzotriazol-1-yl group with Grignard reagents. The 1-[α-(alkylthio)alkyl]- and 1-[α-(arylthio)alkyl]-1H-benzotriazole intermediates are easily available by several routes: (i) displacement of the halogen from appropriate halides by sodium salts of thiols, (ii) condensation of 1H-benzotriazole and thiols with carbonyl compounds, or (iii) lithiation of N-substituted 1H-benzotriazoles and subsequent treatment with electrophiles. 相似文献
53.
Alan J. Chalk 《Journal of organometallic chemistry》1974,76(2):C38-C39
Reactions of MI(CH3)(PPh3)2 or MCl(CH2COR)(PPh3)2 (M = Pd, Pt) with sodium dicyanomethanide in methanol gave novel metal complexes. Spectroscopic data suggest that these complexes contain either an iminoether chelate ring or a carbon-carbon chelate ring which was derived from CH(CN)2-. 相似文献
54.
Goren AC Hrovat DA Seefelder M Quast H Borden WT 《Journal of the American Chemical Society》2002,124(13):3469-3472
Time-dependent B3LYP/6-31G calculations have been performed at the optimized C(2) or C(2v) geometries of several substituted semibullvalenes (1(deloc)) and barbaralanes (2(deloc)), to compare the computed vertical electronic excitation energies with the temperature-dependent, long-wavelength absorptions that have been observed in the UV/vis spectra of some of these compounds by Quast and co-workers. The excellent agreement between the calculated vertical excitation energies and the observed values of lambda(max) provides strong support for the identification of the bishomoaromatic species 1(deloc) and 2(deloc) as the source of these absorptions. Furthermore, the CN stretching frequencies, computed for the C(2) geometry of 1,5-dimethyl-2,6-dicyano-4,8-diphenylsemibullvalene (1f(deloc)), fit the low-frequency absorptions seen in the IR spectrum of 1f, thus furnishing independent evidence that bishomoaromatic geometries of semibullvalenes have, in fact, been observed spectroscopically. B3LYP/6-31G calculations predict that 2,6-dicyano-4,8-diphenylsemibullvalene 1c has a C(2) equilibrium geometry (1c(deloc)) and that the long-wavelength UV/vis absorption (lambda(max) = 585 nm) and CN stretching frequencies (2192 and 2194 cm(-1)) computed for 1c(deloc) should serve to identify this bishomoaromatic semibullvalene when it is synthesized. 相似文献
55.
Lawan Ly Xiaoqian Cheng Saravana R. K. Murthy Olivia Z. Jones Taisen Zhuang Steven Gitelis Alan T. Blank Aviram Nissan Mohammad Adileh Matthew Colman Michael Keidar Giacomo Basadonna Jerome Canady 《Molecules (Basel, Switzerland)》2022,27(13)
Soft tissue sarcomas (STS) are a rare and highly heterogeneous group of solid tumors, originating from various types of connective tissue. Complete removal of STS by surgery is challenging due to the anatomical location of the tumor, which results in tumor recurrence. Additionally, current polychemotherapeutic regimens are highly toxic with no rational survival benefit. Cold atmospheric plasma (CAP) is a novel technology that has demonstrated immense cancer therapeutic potential. Canady Cold Helios Plasma (CHCP) is a device that sprays CAP along the surgical margins to eradicate residual cancer cells after tumor resection. This preliminary study was conducted in vitro prior to in vivo testing in a humanitarian compassionate use case study and an FDA-approved phase 1 clinical trial (IDE G190165). In this study, the authors evaluate the efficacy of CHCP across multiple STS cell lines. CHCP treatment reduced the viability of four different STS cell lines (i.e., fibrosarcoma, synovial sarcoma, rhabdomyosarcoma, and liposarcoma) in a dose-dependent manner by inhibiting proliferation, disrupting cell cycle, and inducing apoptosis-like cell death. 相似文献
56.
Direct measurements of the in-plane London penetration depth λ L have recently been performed on high-temperature superconducting copper oxides by a new low-energy muon spin rotation technique. The results show that λ L is isotope dependent, evidencing unconventional electron–phonon interactions as its source. The data are interpreted here in terms of polaronic effects on the single-particle energies, which leads to level shifts and exponential band narrowing. Good agreement with the experimental data is obtained. 相似文献
57.
58.
59.
R. Alan Aitken Bernd Fodi Michael H. Palmer Alexandra M.Z. Slawin Jing Yang 《Tetrahedron》2012,68(29):5845-5851
The structures of pyridazine N-oxide, pyrimidine N-oxide and pyrazine N-oxide have been determined by X-ray diffraction for the first time. Comparison with theoretical predictions of the equilibrium structures using the B3LYP method together with a cc-pVTZ basis set, show close agreement with the structural parameters observed, and experimental dipole moments, which suggests that the charge distribution is realistic. An ‘atoms in molecules’ (AIM) analysis of the computed wave-functions shows total electron densities rather different from the classical picture of a dative bond, whereas the same wave-functions subjected to Mulliken analysis show a more conventional view of the electron distribution. This latter procedure allows a bond dipole analysis of the N-oxide charge distribution. 相似文献
60.
Cosmological solutions with a homogeneous Yang-Mills field which oscillates and passes between topologically distinct vacua are discussed. These solutions are used to model the collapsing Bartnik-McKinnon gravitational sphaleron and the associated anomalous production of fermions. The Dirac equation is analyzed in these backgrounds. It is shown explicity that a fermion energy level crosses from the negative to positive energy spectrum as the gauge field evolves between the topologically distinct vacua. The cosmological solutions are also generalized to include an axion field. 相似文献