New Li-Mg phosphates with a 3D framework: experimental and ab initio calculations.

Two new lithium-magnesium phosphates LiMg6(PO4)3(P2O7) and Li(Mg5.62Sc0.19Li0.19)(PO4)3(P2O7) were synthesized by a solid-phase method. Using high-resolution time-of-flight neutron powder diffraction (TOF NPD) and X-ray powder diffraction (XRPD), we established that these phosphates have a Pnma orthorhombic structure with the cell parameters a = 9.14664(5) Å, b = 18.83773(8) Å, c = 8.27450(4) Å, and V = 1425.71(1) Å3 and a = 9.14516(5) Å, b = 18.84222(9) Å, c = 8.28204(4) Å, and V = 1427.12(1) Å3, respectively. The crystal structures can be described by stacking of the [Mg6O18]∞ or [Mg5.62Sc0.19Li0.19O18]∞ wavy layers, which are parallel to the (100) direction and interconnected through PO4 tetrahedra and P2O7 groups to form a 3D-framework. The Li atoms are located in large tunnels formed in a 3D lattice, which contributes to lithium diffusion. AC impedance spectroscopy analysis shows that LiMg6(PO4)3(P2O7) and Li(Mg5.62Sc0.19Li0.19)(PO4)3(P2O7) have a Li ion conductivity of 3.6 × 10-4 S cm-1 and 1.7 × 10-4 S cm-1 at 950 °C, with an activation energy of 1.28 eV and 1.55 eV, respectively. NMR MAS studies confirmed the coexistence of pyro- and orthogroups in the structure of both phases and two lithium positions in Li(Mg5.62Sc0.19Li0.19)(PO4)3(P2O7). The first-principles method was used to study the electronic structure and stability of the two phases. The calculated formation enthalpies demonstrated that Sc is a stabilizing impurity in LiMg6(PO4)3(P2O7), while a strong destabilization of olivine LiMgPO4 is observed upon doping with Sc. This explains the failure to synthesize Sc-doped olivine. The new phosphate LiMg6(PO4)3(P2O7) is a dielectric with a band gap of 5.35 eV, which decreases to 4.85 eV due to the appearance of a localized Sc 3d peak upon doping with Sc. These findings are consistent with the results obtained by UV-Vis spectroscopy. The new phase may be a good optical matrix similar to LiMgPO4.

[Medical care provision to the victim children of Haiti].

Treatment and diagnostic measures, including anesthesia during catastrophes and natural disasters are a world known problem. The paper presents the experience of anesthetic care provision during specialized surgical care to the victim children of the earthquake in Haiti. The materials of analysis were 529 anesthesias conducted to 72 children, who were in the treatment for crush syndrome, skeletal and concomitant injury. The peculiarities of anesthesia during the treatment of wound process depending on the stage of surgery are brought into view. During the preparatory phase the optimal type of anesthesia is inhalation and intravenous anesthesia, whereas for the defect closure (main stage) all types of anesthesia, including balanced endotracheal and combined anesthesia were used.

Measurement of the analyzing power in p-->d-->(p p)n with a fast forward 1S0 proton pair.

A measurement of the analyzing power A(y) of the p-->d--> (p p) + n reaction was carried out at the ANKE spectrometer at COSY at beam energies of 0.5 and 0.8 GeV by detection of a fast forward proton pair of small excitation energy E(pp) < 3 MeV. The S-wave dominance in the fast diproton is experimentally demonstrated in this reaction. While at T(p) = 0.8 GeV the measured analyzing power almost vanishes, it rises to nearly unity at T(p) = 0.5 GeV for neutrons emitted at theta(c.m.)(n) = 167 degrees. The results are compared with a model taking into account one-nucleon exchange, single scattering, and Delta(1232) excitation in the intermediate state. The model describes fairly well the unpolarized cross section obtained earlier and the analyzing power at 0.8 GeV; it fails to reproduce A(y) at 0.5 GeV.

Surface coverages of bonded-phase ligands on silica: a computational study.

A computational study of the packing of various bonded-phase ligands bound to chromatographic silica is presented. This is done with the intention of examing the type of surface structures that are typically found in real chromatographic systems. Utilizing the surface structure of the (111) face of the beta-cristobalite crystal, it is shown that the maximum surface coverages of dimethyloctylsilane, dimethyloctadecylsilane, triisopropylsilane, diisopropyloctylsilane, and diisopropyloctadecylsilane can be calculated that are in good agreement with experiment. The maximum surface coverages are also calculated for the (100) face of the beta-cristobalite crystal and for a set of random silica surfaces. The coverages for the latter two surfaces types are found to be significantly lower than the experimental values for chromatographic silica surfaces. These results further suggest that chromatographic silica surfaces may resemble crystalline surface sites similar to the (111) face of beta-cristobalite, as has been previously suggested in the literature. Hence, these structures can be reliably utilized in molecular simulations of bonded-phase chromatography where the atomic-level detail of the silica surface has been previously lacking.

[Morphostatistical characteristics of adenomas of the large intestine based on the data from 1915 autopsies]. / Morfostatisticheskaia kharakteristika adenom tolstoi kishki po dan nym 1915 autopsii.

Large intestine polyps have been revealed in 1372 cases of 1915 autopsies. 4.1% of these have been hyperplastic polyps, 86.2% tubular adenomas, 11.1% tubular-villous and 2.7% villous adenomas. Solitary adenomas have been less frequent than multiple one (42 vs. 58%). The adenomas have been equally incident in the right and left portions of the large intestine, but they have been larger and characterized by a higher degree of epithelial dysplasia in the sigmoid and rectum. Malignant adenomas made up 0.8% of the total number of tumors. Adenomas have been revealed twice more frequently in the patients who died in hospital than in the group of forensic medical autopsies. Multifactorial analysis has demonstrated a correlation between adenoma detection rate and some chronic diseases.

[Correlation analysis of the organometric heart parameters under normal and pathological conditions]. / Korreliatsionnyi analiz organometricheskikh parametrov serdtsa v norme i v patologii.

An organometric study of 27 heart parameters normally, in hypertension, chronic nonspecific pulmonary diseases and ischemic heart disease was carried out. Significant differences in the heart weight values under normal and pathological conditions were found. A correlation analysis of the heart parameters normally and pathologically was performed revealing specific associations for each group of pathology. Increased associations were observed between heart weight values and its parts and the linear-planimetric parameters in the groups of ischemic heart disease and chronic nonspecific pulmonary diseases.