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151.
Rodolfo Moreno‐Fuquen Eustaquio Vinicius Ribeiro de Castro Margarita Moreno Regina Helena De Almeida Santos Angela Marcela Montao 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):206-207
In the title co‐crystal, C7H5NO4·C5H4N2O3, the two components are linked by an intermolecular hydrogen bond between the O—H and N—O groups [O?O 2.577 (3) Å]. The interplanar angle between the planes of the rings of the molecules is 5.3 (2)°. The rings are stacked in the crystal with a mean interplanar distance of 3.279 (3) Å. 相似文献
152.
153.
The experimental and numerical analysis of spheres falling into viscous flows is considered. The physical model is built using a set of silicone and glass spheres falling into oil and water. The rigid‐body trajectory of the sphere and the free surface evolution are obtained from videos. The numerical results are obtained using two different finite element codes. The first code uses a fractional step approach with adaptive meshes and time‐step sizes whereas the second code uses a monolithic fully coupled fixed‐mesh technique. The results exhibit a good comparison between both numerical techniques and with the experiments. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
154.
Jan Chalupa Karel Handlíř Zdeňka Padělková Marcela Vejsová Vladimír Buchta Robert Jirásko Aleš Rûžička 《应用有机金属化学》2008,22(6):308-313
The set of four triorganotin(IV) diesters of 4‐ketopimelic acid containing {2‐[(CH3)2NCH2]C6H4}‐ as a C,N‐chelating ligand was prepared. Their structures were studied by the help of IR, NMR and X‐ray crystallographic techniques in the case of {{2‐[(CH3)2NCH2]C6H4}SnPh2}2[(OOCCH2CH2)2C?]. All these compounds are monomeric both in solid state and solution with five‐coordinated tin atoms and medium strong intramolecular Sn? N connection. The antimycotical activity of these compound was studied and compared with the triorganotin(IV) derivatives of 4‐ketopimelic acid and antimycotical drugs in clinical use. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
155.
156.
J. A. Baeta Segundo Heyder Hey Walter F. Wreszinski 《Journal of statistical physics》1994,76(5-6):1479-1493
We prove that the spectrum defined in terms of the autocorrelation function of a harmonic subject to a quasiperiodic perturbation, is, at resonance, transient absolutely continuous, covering the whole line. In the nonresonant case, and under some supplementary Diophantine condition, it is pure point, coinciding with the spectrum of a special almost-periodic function. 相似文献
157.
The nuclear spin conversion of a molecule is the modification of the total nuclear spin I of its equivalent atoms. This phenomenon is observed by measuring the relaxation rate of a gas sample initially prepared with a population of spin isomers far from the equilibrium given by nuclear spin statistics. New experimental data obtained at low pressure show a surface-induced enhancement of the nuclear spin conversion in 13CH3F. Contrary to binary collisions in the gas phase, hitting the surface induces direct conversion. Several mechanisms are proposed. 相似文献
158.
Mariângela B. M. De Azevedo Joel Alderete Jaime A. Rodriguez Ana O. Souza Daniel Rettori Marcio A. Torsoni Adelaide Faljoni-Alario Marcela Haun Nelson Durân 《Journal of inclusion phenomena and macrocyclic chemistry》2000,37(1-4):93-101
Violacein is a poorly water-soluble antitumoraland antibacterial drug. The solubility can be enhanced by complexation with-cyclodextrin. The inclusion complex was prepared by the co-precipitation method in molarratios of 1 : 1 and 1 : 2 of violacein/-cyclodextrin, respectively. The acutetoxicity (E. coli strain) of violacein did not changeup to 400 M, either in thepresence or absence of cyclodextrin. Cytotoxicity (V-79 cellculture) through DNA and MTT assays was significantlydecreased in the presence of the 1 : 2 molar ratio complex.Studies on erythrocyte lipid peroxidation by the thiobarbituricacid (TBA) methodshowed that violacein and violacein/-CD (1 : 2) at100 M cause 50% and 80% inhibition, respectively. At 500 M theviolacein/-CD complexinhibited lipid peroxidation completely; however, withfree violacein only 65% inhibition was reached at that concentration. 相似文献
159.
Elevated supersaturation of total dissolved gas (TDG) has deleterious effects in aquatic organisms. To minimize the supersaturation of TDG at hydropower dams, spillway flow deflectors redirect spilled water horizontally forming a surface jet that prevents bubbles from plunging to depth in the stilling basin. 相似文献
160.
Alberto Peraza-Labrador Diana Marcela Buitrago Ericsson Coy-Barrera Sandra J. Perdomo-Lara 《Molecules (Basel, Switzerland)》2022,27(11)
The in vitro antiproliferative activity of a phenolic-rich extract from Lycium barbarum fruits against head and neck HPV16 squamous cell carcinoma (OSCC) has been demonstrated, indicating for the first time that L. barbarum extract inhibits human papillomavirus (HPV) type 16 cell lines. Ethanol extract of L. barbarum was used for cell viability evaluation on SCC090, CAL27, and HGnF cell lines. After 24 and 48 h, the cell cycle effect of L. barbarum extract (at 1.0, 10, and 100 µg/mL) was measured via flow cytometry. In addition, the mRNA expression on E6/E7 and p53 via RT-PCR and the expression of p16, p53, Ki-67, and Bcl-2 via immunohistochemistry were also determined. Untreated cells, 20 µM cisplatin, and a Camellia sinensis-derived extract were used as negative and positive controls, respectively. We demonstrated that the studied L. barbarum extract resulted in G0/G1 arrest and S phase accumulation in SCC090 at 1.0 and 10 μg/mL. A reduction in mRNA levels of E6/E7 oncogenes (p < 0.05) with p53 overexpression was also observed through PCR, while immunohistochemical analyses indicated p16 overexpression (p > 0.05) and a decrease in p53 overexpression. The observed effects were associated with anticancer and immunomodulatory phenolics, such as flavonols/flavan-3-ols and tyramine-conjugated hydroxycinnamic acid amides, identified in the studied extract. These findings revealed that the phenolic-rich extract of L. barbarum fruits has promising properties to be considered further for developing new therapies against oral and oropharyngeal HPV lesions. 相似文献