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121.
The UV-Visible absorption Spectra for the complexes cis and trans BrMn(CO)2dppm(P(OPh)3) dppm = Ph2PCH2PPh2 in several solvents are reported and an assignment of their bands is proposed. The cis isomer present one characteristics band in the visible region while that the trans isomer exhibits two well defined absorption bands. This spectral behavior is in agreement with early thermodynamic considerations. 相似文献
122.
E. de Amo M. Díaz Carrillo J. Fernández-Sánchez 《Journal of Mathematical Analysis and Applications》2012,386(2):528-541
The problem of constructing copulas whose supports are fractals has been studied by Fredricks, Nelsen and Rodríguez-Lallena [G.A. Fredricks, R.B. Nelsen, J.A. Rodríguez-Lallena, Copulas with fractal supports, Insurance Math. Econom. 37 (1) (2005) 42–48]. In this paper we continue on the path traced by these authors. We provide different types of families of self-similar copulas using techniques from Probability and Ergodic Theory to give properties on subsets of their fractal supports. In particular, we give new examples for those copulas and we analyze related topics with mutual singularity of the associated measures, Hausdorff dimension, and the connectedness of their supports. 相似文献
123.
The concept of digroup has been proposed as a generalization of continuous groups whose tangent space is a Leibniz algebra. We study a further generalization of the digroup structure in which we do not demand that the inverses are necessarily bilateral. We characterize a generalized digroup as a set and as a product. We show an analogous to the first isomorphism theorem. Additionally, we explore the concept of dialgebra digroup. 相似文献
124.
S. Vega J. A. Díaz V. Darias C. C. SNchez Mateo 《Journal of heterocyclic chemistry》2000,37(2):389-393
In this paper we describe a series of new thieno and pyrazolo[2,1]benzothiazepine derivatives 7a‐o which were synthesized by two different methods both starting from the previously described tricyclic alcohols 1–3 . Several components of this series were effective p. o. (per os, orally) in different pharmacological tests currently employed in the evaluation of antidepressant activity. 相似文献
125.
We present a study of the Gaussian q-measure introduced by Díaz and Teruel from a probabilistic and from a combinatorial viewpoint. A main motivation for the introduction of the Gaussian q-measure is that its moments are exactly the q-analogues of the double factorial numbers. We show that the Gaussian q-measure interpolates between the uniform measure on the interval [−1,1] and the Gaussian measure on the real line. 相似文献
126.
R. C. Díaz M. A. Sarasa C. Ríos J. J. Cuello 《Accreditation and quality assurance》1999,4(11):473-476
The determination of dichlorobenzene and naphthalene in commercial repellents used in Spain has been validated. This was
done using an isocratic regime, to test the reverse -phase HPLC system with acetonitrile: water 65 : 35 (v: v) as the mobile
phase, at 20 °C. This technique is proposed for the modular validation of the HPLC system . The results obtained with this
method show good agreement with the results provided by the manufacturers of the mothrepellents.
Received: 21 December 1998 / Accepted: 4 May 1999 相似文献
127.
B. Juliá-Díaz 《Few-Body Systems》2008,43(1-4):103-108
Recent developments on a dynamical coupled-channels model of hadronic and electromagnetic production of nucleon resonances are summarized. 相似文献
128.
UV spectrophotometric flow-injection assay of tetracycline antibiotics retained on Sephadex QAE A-25 in drug formulations 总被引:1,自引:0,他引:1
A. Ruiz Medina M. G. García Marín M. L. Fernndez de Crdova A. Molina Díaz 《Microchemical Journal》2000,65(3)
A flow injection analysis system with solid phase spectrophotometric transduction has been developed for the assay of tetracycline (TC), doxycicline (DTC), oxycicline (OTC) and chlortetracycline (CTC). The packing material of the flow-through cell consists of Sephadex QAE A-25 resin on which tetracyclines are temporarily retained. The carrier itself acts as the desorbing solution. The measurements of the intrinsic absorbance of tetracyclines (1000 μl of sample volume) were made at 380 nm (TC, DTC and OTC) and 387 nm (CTC). The detection limits were found to be 0.069 (TC and OTC), 0.081 (DTC) and 0.121 (CTC) μg ml−1 and the linear dynamic range extended between 0.5 and 12 (TC, DTC and OTC) and 1–20 μg ml−1 (CTC). The relative standard deviations (n=10) ranged between 0.7 and 1.2%. A study of the potentially interfering species was carried out. Using the proposed method, tetracyclines were satisfactorily determined without any interference from excipients in pharmaceutical preparations. 相似文献
129.
Antonio Casado-D��az Raquel Santiago-Mora Jos�� Manuel Quesada 《Experimental & molecular medicine》2010,42(2):87-98
Parathyroid hormone-related protein (PTHrP) is synthesized by diverse tissues, and its processing produces several fragments, each with apparently distinct autocrine and paracrine bioactivities. In bone, PTHrP appears to modulate bone formation in part through promoting osteoblast differentiation. The putative effect of PTH-like and PTH-unrelated fragments of PTHrP on human mesenchymal stem cell (MSCs) is not well known. Human MSCs were treated with PTHrP (1-36) or PTHrP (107-139) or both (each at 10 nM) in osteogenic or adipogenic medium, from the start or after 6 days of exposure to the corresponding medium, and the expression of several osteoblastogenic and adipogenic markers was analyzed. PTHrP (1-36) inhibited adipogenesis in MSCs and favoured the expression of osteogenic early markers. The opposite was observed with treatment of MSCs with PTHrP (107-139). Moreover, inhibition of the adipogenic differentiation by PTHrP (1-36) prevailed in the presence of PTHrP (107-139). The PTH/PTHrP type 1 receptor (PTH1R) gene expression was maximum in the earlier and later stages of osteogenesis and adipogenesis, respectively. While PTHrP (107-139) did not modify the PTH1R overexpression during adipogenesis, PTHrP (1-36) did inhibit it; an effect which was partially affected by PTHrP (7-34), a PTH1R antagonist, at 1 µM. These findings demonstrate that both PTHrP domains can exert varying effects on human MSCs differentiation. PTHrP (107-139) showed a tendency to favor adipogenesis, while PTHrP (1-36) induced a mild osteogenic effect in these cells, and inhibited their adipocytic commitment. This further supports the potential anabolic action of the latter peptide in humans. 相似文献
130.
Summary On the basis of a quantum-statistical model recently discussed, we deal in this paper with the perturbations induced by the
intense field of a CO2 laser on the levels of the vibrational pattern of a molecule undergoing multiphoton unimolecular dissociation. This perturbational
correction is investigated by using a displacement operator technique and the results are interpreted according to the statistical
model.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献