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1.
J Chem Phys ; 138(16): 164306, 2013 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-23635137

RESUMEN

Benchmark results for electron densities in the ground states of Li(-), Be, C(2+), Ne(6+), and Ar(14+) have been generated from very accurate variational wave functions represented in terms of extensive basis sets of exponentially correlated Gaussian functions. For Ne(6+), and Ar(14+), the upper bounds to the energies improve over previous results known from the literature. For the remaining systems our bounds are from 0.1 to 1.1 µhartree higher than the most accurate ones. We present in graphical and, partially, numerical form results both for the radial electron densities and for the difference radial density distributions (DRD) (defined with respect to the Hartree-Fock radial density) that highlight the impact of correlation effects on electron densities. Next, we have employed these DRD distributions in studies of the performance of several broadly used orbital-based quantum-chemical methods in accounting for correlation effects on the density. Our computed benchmark densities for Be have been also applied for testing the possibility of using the mathematically strict result concerning exact atomic electron densities, obtained by Ahlrichs et al. [Phys. Rev. A 23, 2106 (1981)], for the determination of the reliability range of computed densities in the long-range asymptotic region. The results obtained for Be are encouraging.


Asunto(s)
Berilio/química , Electrones , Teoría Cuántica
2.
J Chem Phys ; 130(16): 164102, 2009 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-19405556

RESUMEN

The problem of linking the dynamic electron correlation effects defined in traditional ab initio methods [or wave function theories (WFTs)] with the structure of the individual density functional theory (DFT) exchange and correlation functionals has been analyzed for the Ne atom, for which nondynamic correlation effects play a negligible role. A density-based approach directly hinged on difference radial-density (DRD) distributions defined with respect the Hartree-Fock radial density has been employed for analyzing the impact of dynamic correlation effects on the density. Attention has been paid to the elimination of basis-set incompleteness errors. The DRD distributions calculated by several ab initio methods have been compared to their DFT counterparts generated for representatives of several generations of broadly used exchange-correlation functionals and for the recently developed orbital-dependent OEP2 exchange-correlation functional [Bartlett et al., J. Chem. Phys. 122, 034104 (2005)]. For the local, generalized-gradient, and hybrid functionals it has been found that the dynamic correlation effects are to a large extend accounted for by densities resulting from exchange-only calculations. Additional calculations with self-interaction corrected exchange potentials indicate that this finding cannot be explained as an artifact caused by the self-interaction error. It has been demonstrated that the VWN5 and LYP correlation functionals do not represent any substantial dynamical correlation effects on the electron density, whereas these effects are well represented by the orbital-dependent OEP2 correlation functional. Critical comparison of the present results with their counterparts reported in literature has been made. Some attention has been paid to demonstrating the differences between the energy- and density-based perspectives. They indicate the usefulness of density-based criteria for developing new exchange-correlation functionals.

3.
J Control Release ; 50(1-3): 267-72, 1998 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-9685893

RESUMEN

The efficacy of passive transdermal versus electrically-enhanced, or iontophoretic delivery of insulin was studied. The effect of skin pre-treatment on iontophoretic delivery of insulin was also investigated. Rectangular pulses of 0.25 mA/cm2 current amplitude, 2 kHz frequency, and 50% duty cycle were used as anodal stimulation for electrically enhanced transdermal delivery of insulin. Twenty (20) BB/Wor chronic diabetic adult male rats were shaved 48 h prior to the study, and some experimental groups had hair stubble removed with a depilatory lotion. The iontophoretic drug-containing electrode was filled with 3 ml of porcine regular insulin (100 IU/ml) which has been adjusted to an acidic pH of 3.68 using 0.1 M HCl. The iontophoretic electrodes were then adhered to the abdomen of the alert rat. Results of the iontophoretic procedure were quantified by monitoring changes in blood glucose levels. When insulin was placed on the shaved skin, blood glucose levels fell in the chronic diabetic rat. In general, glucose levels fell more quickly and more profoundly using an iontophoretic enhancement of transdermal insulin delivery. However, some skin preparations facilitated movement of insulin more efficiently. The most profound effect of lowered blood glucose occurred when a depilatory lotion was used on the day of the study in conjunction with iontophoresis, where blood glucose levels fell by 61% after 1 h of iontophoretic treatment. Results indicate that insulin was delivered passively at therapeutic levels when the skin had been treated with the depilatory lotion on the same day as the study, was measured through a reduction in blood glucose levels of 29% after 1 h of passive delivery. When the depilatory lotion was used 24 h prior to iontophoresis, blood glucose remained near initial blood glucose levels. In the groups that did not have the depilatory lotion applied, blood glucose levels fell by 8% after 1 h of iontophoretic insulin delivery. The experimental evidence indicates a substantial increase in the penetration of insulin with the same-day application of depilatory lotion in conjunction with iontophoretic enhancement.


Asunto(s)
Diabetes Mellitus/tratamiento farmacológico , Insulina/administración & dosificación , Piel/metabolismo , Administración Cutánea , Animales , Glucemia/análisis , Enfermedad Crónica , Insulina/farmacocinética , Iontoforesis , Masculino , Ratas
4.
Pol Merkur Lekarski ; 6(33): 141-2, 1999 Mar.
Artículo en Polaco | MEDLINE | ID: mdl-10365599

RESUMEN

We demonstrate the case of 47 year old woman with chylopericardium after mitral valve replacement. By reason of heart tamponade she underwent surgical treatment resulted in complete relief of the pericardial effusion.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas/métodos , Insuficiencia de la Válvula Mitral/cirugía , Derrame Pericárdico/cirugía , Complicaciones Posoperatorias/cirugía , Femenino , Humanos , Persona de Mediana Edad
9.
Pol Tyg Lek ; 46(19-21): 386-8, 1991.
Artículo en Polaco | MEDLINE | ID: mdl-1845680

RESUMEN

Comparison of the scintigraphic diagnosis of the myocardial infarction with two radioactive substances is presented. Pyrophosphate labelled with radioactive 99mTc and anti-myosins labelled with radioactive 111In were used for this purpose.


Asunto(s)
Radioisótopos de Indio , Infarto del Miocardio/diagnóstico por imagen , Pirofosfato de Tecnecio Tc 99m , Anticuerpos Monoclonales/análisis , Humanos , Miosinas/inmunología , Cintigrafía
10.
Comput Chem ; 24(3-4): 263-74, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10815996

RESUMEN

The density functional theory (DFT) calculations in different approximations have been performed for the geometries and vibrational states of the trans-glyoxal molecule in the ground state S0 (X1Ag) and in the lowest excited triplet state T1 (a3Au, n-pi* type). Eight typical combinations of exchange and correlation functionals have been used. Comparative Hartree-Fock (HF) calculations have also been performed. For the open shell a3Au state the standard spin-unrestricted Hartree-Fock and Kohn-Sham approaches (UHF, UKS) as well as the restricted open-shell versions (ROHF, ROKS) have been applied. The calculated frequencies have been compared, among others, with the data resulting from the most recent phosphorescence exicitation spectra of glyoxal cooled in the supersonic molecular beam, recorded with the cooperation of one of us (JH) for the spin-forbidden S0-T1 transition. The most realistic description of the vibrational frequencies, within the unscaled harmonic approximation, can be obtained using the 3-parameter Becke-93 exchange functional (B3), whereas this description practically does not depend on the correlation functional used. Our calculations support the recently reexamined experimental energy of the symmetric CH-rocking fundamental for the T1 state.

11.
Pol Arch Med Wewn ; 105(4): 297-302, 2001 Apr.
Artículo en Polaco | MEDLINE | ID: mdl-11761801

RESUMEN

Two electrocardiographic types of inferior wall infarct were isolated based on angiographic localization of right coronary artery occlusion. In proximal occlusion of RCA before right ventricular branch there is no depression or more rarely elevation of ST segment in V1-V3 especially in V1 (the first morphological type). ST segment depression in V1-V3 (second morphological type) is characteristic for distal segment of RCA occlusion.


Asunto(s)
Estenosis Coronaria/complicaciones , Estenosis Coronaria/fisiopatología , Infarto del Miocardio/etiología , Angiografía , Estenosis Coronaria/diagnóstico , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Disfunción Ventricular Derecha/diagnóstico , Disfunción Ventricular Derecha/etiología , Disfunción Ventricular Derecha/fisiopatología
12.
Biochemistry ; 24(6): 1418-24, 1985 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-3157402

RESUMEN

The experiments here show that chemically synthesized DNA containing fluorine at selected sites can be used to test specific predictions of a model for cro repressor--operator interaction. This is done by observation of the perturbation to the fluorine-19 NMR spectra of analogues of OR3 synthesized with 2'-deoxy-5-fluorouracil at specific positions in the DNA helix. Although the three-dimensional structure of the cro repressor from phage lambda has been determined by Matthews and co-workers [Anderson, W., Ohlendorf, D., Takeda, Y., & Matthews, B. (1981) Nature (London) 290, 754-758], direct structural observations on the complex of the protein with its specific DNA recognition sequence, OR3, are limited. From that structure of the protein, alone, a model of its complex to DNA was built by fitting B-form DNA, with some distortion [Ohlendorf, D., Anderson, W., Fisher, R., Takeda, Y., & Matthews, B. (1982) Nature (London) 298, 718-723]. That model proposes that the cro repressor contacts only one side of this DNA double helix and a number of specific protein--DNA contacts. To test the model, 2'-deoxy-5-fluorouracil was used to place the fluorine-19 nuclear spin-label on the side of the DNA contacting the cro repressor and on the opposite side facing away from the cro repressor. The results presented here are consistent with the prediction that lambda phage cro repressor contacts only one side of the DNA double helix.


Asunto(s)
Bacteriófago lambda/genética , ADN Viral/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Secuencia de Bases , Fluorescencia , Espectroscopía de Resonancia Magnética , Modelos Moleculares
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