Quantum-mechanical ab initio simulation of the Raman and IR spectra of Fe3Al2Si3O12 almandine.

The IR and Raman spectra of the Fe(3)Al(2)Si(3)O(12) almandine garnet were simulated using the periodic CRYSTAL code with an all-electron Gaussian-type basis set and the hybrid B3LYP functional. The wavenumbers of the 25 Raman-active modes (3 of A(1g), 8 of E(g), and 14 of F(2g) symmetry) and 34 F(1u) IR-active modes (17 TO and 17 LO) were computed, as were the IR intensities. Calculated wavenumbers are in excellent agreement with the various sets of experimental results, with the mean absolute difference |Delta| being between 4 and 8 cm(-1). Graphical animation, available on the CRYSTAL Web site, provides a very comprehendible description of the movement of atoms and groups in each vibrational mode. The simulated reflectivity spectrum, obtained using a classical dispersion relation, is in excellent agreement with the measured one.

Ab initio simulation of the IR spectra of pyrope, grossular, and andradite.

IR spectra of pyrope Mg(3)Al(2)Si(3)O(12), grossular Ca(3)Al(2)Si(3)O(12) and andradite Ca(3)Fe(2)Si(3)O(12) garnets were simulated with the periodic ab initio CRYSTAL code by adopting an all-electron Gaussian-type basis set and the B3LYP Hamiltonian. Two sets of 17 F(1u) Transverse Optical (TO) and Longitudinal Optical (LO) frequencies were generated, together with their intensities. Because the generation of LO modes requires knowledge of the high frequency dielectric constant epsilon(infinity) and Born effective charges, they were preliminary evaluated by using a finite field saw-tooth model and well localized Wannier functions, respectively. As a by-product, the static dielectric constant epsilon(0) was also obtained. The agreement of the present calculated wavenumbers (i.e. peak positions) with the available experimental data is excellent, in that the mean absolute difference for the full set of data smaller than 8 cm(-1). Missing peaks in experimental spectra were found to correspond to modes with low calculated intensities. Correspondence between TO and LO modes was established on the basis of the overlap between the eigenvectors of the two sets and similarity of isotopic shifts; as result, the so called LO-TO splitting could be determined. Animation of the normal modes was employed to support the proposed pairing.

Bullous pemphigoid and pemphigus vulgaris: correlated behaviour of serum VEGF, sE-selectin and TNF-alpha levels.

BACKGROUND: Recently, we reported that soluble E-selectin (sE-selectin), an isoform of the cell membrane E-selectin, an adhesion molecule synthesized only by endothelial cells, is significantly increased in sera of the patients with bullous pemphigoid (PB) or pemphigus vulgaris. A significant correlation was also found between the serum sE-selectin levels and the number of skin lesions, suggesting the possible use of this molecule to gauge disease intensity before therapy. One of the sE-selectin inducers is tumor nerosis factor-alpha (TNF-alpha), that is also able to enhance vascular endothelial growth factor (VEGF), a strong endothelium activator. OBJECTIVE: On the basis of these observations, the present study was conducted to analyze the serum levels of VEGF, sE-selectin, and TNF-alpha in 8 patients with BP (age: 82, range 54-87, 7 males, 1 female) and in 6 patients affected affected with PV (age: 55, range 44-65; 5 males, 1 female) and to verify possible correlations between these variables and the disease activity, In addition, serum sE-selectin levels were measured over time and compared with the serum anti-epithelium antibodies titers. METHODS: The sE-selectin, VEGF and TNF-alpha levels were measured in the samples by means of commercially available ELISA kit. The same samples were also employed to measure the anti-epithelium antibody titers. RESULTS: Serum VEGF, sE-selectin and TNF-alpha levels were significantly correlated each other (p at least < 0.01). All three variables were also significantly correlated with the number of lesions (p at least < 0.01). Serum VEGF levels were found increased (median = 178 pg/ml, range 37-595) as compared to 28 healthy controls (median = 135 pg/ml, range 18/269, p < 0.05). Also serum TNF-alpha levels were found increased (median = 5.5 pg/ml, range < 0.1-41.0) as compared to 28 healthy controls (median < 0.1 pg/ml, range < 0.1-5.3), p < 0.01). When the patients were observed over time, serum sE-selectin levels highly correlated with the disease intensity in both dermatoses, although with different regression curves. CONCLUSIONS: These data further underline the endothelium involvement in these bullous dermatoses and stress the possibility of employing sE-selectin as a non-specific follow-up marker of both BP and PV.

[Seborrhea-like dermatitis in the acquired immunodeficiency syndrome. Clinical, histological, and microbiological aspects and biochemical findings]. / La dermatite seborroica-like nella sindrome da immunodeficienza acquisita. Aspetti clinici, istologici, microbiologici e rilievi biochimici.

Seventy-six patients diagnosed as having seborrheic dermatitis (SD) were divided into two groups: group A (n = 22) otherwise healthy subjects (HIV negative) and group B (n = 54) HIV positive (ARC and AIDS cases). Thirty normal healthy subjects without SD were considered as control (group C). The three groups were subjected to the following analyses: A) skin surface lipids (SSL) and fatty acid pattern of cholesterol esters, wax esters, triglycerides and free fatty acids fractions in the affected areas; B) plasma levels of Vitamin E and fatty acids of phospholipids; C) erythrocyte glutathione peroxidase (3 cases for each group); D) frequency of Pityrosporum species in the affected areas; E) skin biopsy in the affected areas (2 cases for each group). Histological findings paralleled those reported in the Literature. SSL composition, fatty acid pattern and frequency of Pityrosporum species did not show significant variation among the 3 groups. On the contrary the blood levels of Vitamin E, polyunsaturated fatty acids of phospholipids and glutathione peroxidase were found significantly lower in A and B groups than in the controls.