Особенности спектров ИК отражения и комбинационного рассеяния кристаллов Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-x-=/SUB=-Se-=SUB=-x-=/SUB=-

A comprehensive study (X-ray phase analysis, Raman spectroscopy, and IR reflectance measurements) of p -Sb_2Te_3 – _ x Se_ x (0 ≤ x ≤ 0.10) crystals synthesized by the Czochralski method is carried out. The X-ray phase data and Raman spectra show that all of the alloy samples under study are rhombohedral crystals in structure, with unit-cell parameters close to those of Sb_2Te_3 crystals. At the same time, the formation of regions with different degrees of the replacement of Te atoms with Se atoms is observed. The reflectance spectra of the crystals, R (ν), have a characteristic minimum at about 1000 cm^–1. The minimum is attributed to hole plasma vibrations. The plasma minimum systematically shifts to higher frequencies, as the Se content is increased. Calculation of the reflectance spectra in the context of the Drude–Lorentz model satisfactorily describes the experimental data; in this case, it is necessary to take into account also the contribution of optical crystal-lattice vibrations to spectra in the low-frequency region. The calculation makes it possible to determine the optical parameters of the crystals and to estimate the hole effective mass and the optical conductivity.

Use of Linezolid to Treat MRSP Bacteremia and Discospondylitis in a Dog

A 1.5 yr old male German shepherd dog was evaluated for recurrent intermittent episodes of fever and lethargy. Clinicopathologic abnormalities were suggestive of a discospondylitis at the seventh and eighth thoracic vertebrae. Blood and urine cultures yielded growth of methicillin-resistant Staphylococcus pseudintermedius (MRSP) that was resistant to all commonly used antibiotics. Extralabel antibiotic susceptibility testing demonstrated susceptibility of both blood and urine isolates to linezolid. The prescribed dose was extrapolated from pharmacokinetic (PK) studies and the isolate’s plasma minimum inhibitory concentration (MIC). Linezolid was administered for 23 wk and resulted in successful resolution of bacteremia, bacteriuria, and discospondylitis. When justified, linezolid should be considered to treat methicillin-resistant infections.

Effect of atropine on plasma amino acid levels and milk secretion of cows

SummarySubcutaneous injections of 30 mg atropine into lactating cows induced a 20–40% decrease of free amino acid (AA) levels in arterial plasma. Minimum levels were observed after 30–50 min. The decline persisted for more than 6 h. The greatest fall in concentration was noted for tyrosine, methionine, lysine, arginine, phenylalanine and threonine. Arterial glucose levels remained unaffected. The effect of atropine on milk secretion was studied in 2 cows which were milked every hour with the aid of oxytocin. Maximal effects were observed after 3–4 h. They included reduction in concentration of casein and ±-lactalbumin (±-la) and a decline in production of milk (20%), casein (35%), ±-la (45%) and lactose (18%). Uptake by the lactating udder over a period of about 1 h after injection of atropine was studied in 2 cows. Mammary blood flow and glucose uptake remained unaffected. There was a positive correlation between arteriovenous differences of essential AA and arterial plasma concentrations. The uptake of essential AA decreased by approximately 50 %. There was no evidence that atropine has a direct inhibiting effect on the udder. It is suggested that the decrease of ±-la synthesis might induce an inhibition of lactose synthesis and milk production.