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111.
We obtain a local characterization of the point of continuity property for bounded subsets in Banach spaces not containing basic sequences equivalent to the standard basis of ℓ1 and, as a consequence, we deduce that, in Banach spaces with a separable dual, every closed, bounded, convex and nonempty subset failing the point of continuity property contains a further subset which can be seen inside the set of Borel regular probability measures on the Cantor set in a weak-star dense way. Also, we characterize in terms of trees the point of continuity property of Banach spaces not containing ℓ1, by proving that a Banach space not containing ℓ1 satis- fies the point of continuity property if, and only if, every seminormalized weakly null tree has a boundedly complete branch. 相似文献
112.
113.
Areli A. Molina‐Paredes Víctor M. Jimnez‐Prez Jesús A. Lara‐Cern Ivana Moggio Eduardo Arias Rosa Santilln Mario Snchez Alma Saucedo‐Yaez Blanca M. Muoz‐Flores 《应用有机金属化学》2019,33(1)
Five novel organoboron complexes were synthesized in just 15 min via microware irradiation, by one pot multicomponent reactions between diverse aryl aldehydes with benzoylhydrazide, or 4‐nitrobenzoylhidrazine and diphenyl boronic acid, in a 1:1:1 ratio in benzene. The products were characterized by 1H, 13C, 11B NMR, UV, IR, spectroscopy and high‐resolution mass spectrometry (HRMS). The molecular structure was also determined by single‐crystal X‐ray diffraction for two complexes, which showed the tetra‐coordination of the boron atoms giving rise to distorted tetrahedral molecular geometry with a strong intermolecular C‐H···π interactions. In spite of the low quantum yields exhibited by the series in solution, some complexes stained uniformly the silk fibroins emitting enough fluorescence to allow its characterization by confocal microscopy. Boron as chelate center of the five complexes resulted not to be toxic for B16F10 cells, these compounds are appropriate for their used in medical applications. 相似文献
114.
115.
A. Frank R. Lemus R. Bijker F. Pérez-Bernal J. M. Arias 《Czechoslovak Journal of Physics》1998,48(6-7):782-788
An algebraic method especially suited to describe the strongly anharmonic vibrational spectra in molecules may be an appropriate
framework to study the vibrational spectra of Na
n
+
clusters, where nearly flat potential energy surfaces and the appearance of close lying isomers have been reported. As an
illustration we describe the model and apply it to the Be4, H
3
+
, Be3 and Na
3
+
clusters.
Presented by A. Frank at the International Conference on “Atomic Nuclei and Metallic Clusters”, Prague, September 1–5, 1997.
This work was supported in part by the European Community under contract No. CI1*-CT94-0072, DGAPA-UNAM under project IN101997
and Spanish DGCYT under project PB92-0663. 相似文献
116.
G.A. Torchia C. Mendez I. Arias L. Roso A. Ródenas D. Jaque 《Applied physics. B, Lasers and optics》2006,83(4):559-563
Femtosecond laser writing has been used to create 1D and 2D diffracting microstructures in Nd3+:MgO co-doped LiNbO3 crystals. The main characteristics of the diffracting device, such as its polarization dependence and diffraction efficiency have been investigated, showing that first order diffraction efficiencies in excess of 35% can be achieved. We have demonstrated that continuous wave laser oscillation from Nd3+ ions at 1.06 μm can be generated through the integrated diffraction gratings, thus leading to non-collinear intracavity laser propagation. The laser performance, in terms of laser thresholds and slope efficiencies, is reported and explained. The achievement of a controlled non-collinear propagation is an interesting feature in multi-frequency lasers, optical communication and optical switching. PACS 42.55.Rz; 42.70.Hj; 42.25.Fx 相似文献
117.
G. Portnov A.-N. Uthe I. Cruz R. P. Fiffe F. Arias 《Mechanics of Composite Materials》2005,41(3):241-254
The possibility of using forced winding coupled with in situ curing to increase the energy storage capacity of hybrid steel-composite cylindrical flywheels is estimated and analyzed. Stress states for given loading conditions in two- and three-layered compound cylinders made from steel and four different types of unidirectional composites are calculated. For each of these combinations, optimum dimensions and the energy storage capacity of the flywheels are found.__________Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 41, No. 3, pp. 351–372, May–June, 2005. 相似文献
118.
In this work, the rheological, thermal and mechanical properties of melt-compounded flax fiber-reinforced polylactide composites were investigated. The effect of compounding on fiber length and diameter, and the relationship between fiber content and the crystallization behavior of the biocomposites, at various temperatures, were also examined. After melt-compounding, fiber bundles initially present were, to a large extent, broken into individual fibers and the fiber length was decreased by 75 %, while the aspect ratio was decreased by nearly 50 %. The crystallization half-time was found to decrease with increasing flax fiber content, and showed a minimum value at 105 °C for all systems. The elastic modulus was increased by 50 % in the presence of 20 wt% flax fibers. The addition of maleic anhydride-grafted polylactide had a positive effect on the mechanical properties of the biocomposite. This system is particularly interesting in the context of sustainable development as it is entirely based on renewable resources and biodegradable. 相似文献
119.
J.R. Moyano J.M. Lines M.J. Arias J.I. Perez-Martinez G. Bettinetti F. Giordano 《Journal of inclusion phenomena and macrocyclic chemistry》1996,25(1-3):137-140
The study of complexation between GL and -CD in liquid medium has been carried out by phase-solubility,1H and13C NMR studies. A formation complex is observed from the phase solubility diagram, being the average association constant of 1094 M–1, The NMR studies revealed the preferent complexation of the aliphatic moiety of GL. The aromatic moiety is also entrapped, but in minor extent, by the CD molecules. 相似文献
120.
Hugo R. Arias Katarzyna M. Targowska-Duda Jesús García-Colunga Marcelo O. Ortells 《Molecules (Basel, Switzerland)》2021,26(8)
It is generally assumed that selective serotonin reuptake inhibitors (SSRIs) induce antidepressant activity by inhibiting serotonin (5-HT) reuptake transporters, thus elevating synaptic 5-HT levels and, finally, ameliorates depression symptoms. New evidence indicates that SSRIs may also modulate other neurotransmitter systems by inhibiting neuronal nicotinic acetylcholine receptors (nAChRs), which are recognized as important in mood regulation. There is a clear and strong association between major depression and smoking, where depressed patients smoke twice as much as the normal population. However, SSRIs are not efficient for smoking cessation therapy. In patients with major depressive disorder, there is a lower availability of functional nAChRs, although their amount is not altered, which is possibly caused by higher endogenous ACh levels, which consequently induce nAChR desensitization. Other neurotransmitter systems have also emerged as possible targets for SSRIs. Studies on dorsal raphe nucleus serotoninergic neurons support the concept that SSRI-induced nAChR inhibition decreases the glutamatergic hyperstimulation observed in stress conditions, which compensates the excessive 5-HT overflow in these neurons and, consequently, ameliorates depression symptoms. At the molecular level, SSRIs inhibit different nAChR subtypes by noncompetitive mechanisms, including ion channel blockade and induction of receptor desensitization, whereas α9α10 nAChRs, which are peripherally expressed and not directly involved in depression, are inhibited by competitive mechanisms. According to the functional and structural results, SSRIs bind within the nAChR ion channel at high-affinity sites that are spread out between serine and valine rings. In conclusion, SSRI-induced inhibition of a variety of nAChRs expressed in different neurotransmitter systems widens the complexity by which these antidepressants may act clinically. 相似文献