High pressures studies on bis(L-alaninate)copper(II) by Raman spectroscopy and synchrotron X-ray diffraction.

The crystal of bis(L-alaninate)copper(II) [Cu(C3H6NO2)2] was studied by Raman spectroscopy and synchrotron X-ray diffraction as a function of hydrostatic pressure, and its vibrational and structural behavior were investigated to analyze its stability at high pressures. The Raman spectra of bis(L-alaninate)copper(II) show changes in vibrational modes that are associated with deformations and stretching of units involving the copper atom. These results indicate that molecular fragments involving the copper atom undergo rotations and discontinuities in bond lengths. The lattice parameters of bis(L-alaninate)copper(II) obtained from Le Bail fits also exhibit changes in the same pressure ranges as the Raman spectra. The discontinuities in the angular parameter beta are compatible with the rotations of the molecular fragments. Bis(L-alaninate)copper(II) undergoes changes, but maintains monoclinic symmetry in the range of 0-20.1 GPa.

Synchrotron radiation X-ray diffraction and Raman spectroscopy study of l-asparagine monohydrate doped with Fe(III) at high pressure.

Crystals of l-asparagine monohydrate doped with Fe(III) were studied by Raman spectroscopy in a diamond anvil cell (DAC) in the spectral range from 100 to 3200 cm-1 and pressures up to 9.2 GPa. The behavior of external modes suggests conformational changes between 3.0 and 4.0 GPa mainly affecting the CH2 group. X-ray diffraction measurements with synchrotron radiation were performed in the angular range from 3 to 12 degrees (2θ) up to 9.3 GPa. The lattice parameters contract up to 9.3 GPa, with the exception of parameter b, which exhibits expansion from 7.2 GPa. The lattice parameters exhibit discontinuities between 3.0 and 4.0 GPa, this effect is compatible with conformational changes. Such modifications occur without a change in symmetry, at least up to 9.3 GPa. Under decompression, down to atmospheric pressure, the original Raman spectrum is recovered, showing that the conformational change and the other changes are all reversible.

Physical approach for a quantitative analysis of the phytosterols in free phytosterol-oil blends by X-ray Rietveld method.

This study investigates and compares the thermal phase transition and crystallization characteristics of a commercial food grade free phytosterol blend (FP) with a stigmasterol analytical standard (SS), the FP behavior in a food model system after its addition to high oleic sunflower oil (HOSO). The properties of the FP:HOSO blends were studied by differential scanning calorimetry, solid content, crystal morphology, and X-ray diffraction (XRD) measurements. The Rietveld method (RM) was applied associated with the XRD measurements to support phase analysis and the study of crystallinity degree. The materials were also characterized by means of chemical composition, such as fatty acids and triacylglycerol profiles, for HOSO, and phytosterol profile, for FP. Regarding phase behavior and crystallinity properties, FP has very similar characteristics to SS. The thermal behavior of FP:HOSO blends has two characteristic peaks, one from FP and the other from HOSO. The similarity reported in the literature between the diffraction pattern of FP and pure phytosterols is a positive characteristic for FP. A high FP concentration resulted in high supersaturation and thus the formation of small crystals. The incorporation of HOSO reduced of the large agglomeration of FP crystals and the dispersion crystalline aggregates (spherulites) of FP crystals. The application of RM in FP:HOSO blends to quantify the crystalline and amorphous phases was successfully used. The application has provided the expected value for these phases, according to the same experimental mass ratio of the blends, thereby validating the applicability of this approach in this type of material.

Elective coronary stent implantation in cardiogenic shock complicating acute myocardial infarction: in-hospital and six-month clinical and angiographic results.

Effective treatment of patients with acute myocardial infarction and cardiogenic shock depends on restoring persistent patency of the infarct-related artery. Coronary stenting, reducing abrupt or delayed closure related to dissection and suboptimal result, may improve PTCA results in cardiogenic shock. Eighteen patients (14 males and 4 females, mean age 59 +/- 7 years), referred to catheterization laboratory for acute myocardial infarction and shock, had elective stent implantation during 14 primary and 4 rescue PTCA. Time delay between shock onset and PTCA was 4.1 +/- 3 hr (range, 30 min to 12 hr). The IRA was LAD in seven patients (38%), LCx in two (11%), and RCA in eight (45%). One patient (5.%) had distal LMCA occlusion. Stent deployment was successful in 100% of patients and resulted in TIMI 3 flow in 13 (72%) patients. In 13 (72%) cases, cardiogenic shock gradually resolved and the patients were discharged alive. Five patients (28%) died because of irreversible hemodynamic deterioration without evidence of reinfarction. At 6-month follow-up, all the discharged patients were alive and no patient had reinfarction or recurrent angina. Heart transplant was required in one patient 5 months after stenting because of refractory congestive heart failure. Angiography demonstrated patency of all the coronary arteries treated, with TIMI 3 flow in all patients. Stent restenosis rate was 30%, and target lesion revascularization with CABG or re-PTCA was not required in any case. LV function improved from 39% +/- 15% to 51% +/- 15% (P < 0.01). Elective coronary stenting is an effective treatment for acute myocardial infarction complicated by cardiogenic shock and may improve acute and long-term survival.