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The products of the insertion reaction of Hg(3P1) in the SiH (SiD) bond of h- or d-silane in nitrogen and rare gas matrixes were studied by Fourier transform infrared spectroscopy. Results showed that the reaction occurs without activation energy. Disilane molecules were produced from the dimers of parent molecules close to mercury or from the complexes of the insertion products with the parent molecules. A mixed CH4/SiH4 experiment provided the ratio of the insertion rates in these two molecules.

The influence of dietary supplementation with raw or heated rapeseeds on the digestion, ruminal characteristics and duodenal nitrogen flow in lactating dairy cows was determined. Rapeseeds decreased organic matter digestibility and increased propionate proportion in ruminal volatile fatty acids. Heat treatment of rapeseeds did not affect dry matter and organic matter digestibility but increased that of nitrogen. No dietary effects were observed in the duodenal flow of nutrients. Results indicate that inclusion of rapeseeds in hay-based diets will not adversely affect fiber digestion in dairy cattle.

The nitric oxide dimers isolated in neon or nitrogen matrices have been irradiated in the infrared by selected lines of a cw CO laser and in the UV at 193 nm by an ArF excimer laser. IR excitation of the antisymmetric mode of the cis dimer in neon induces a conversion to a special van der Waals dimer. At T<6 K UV irradiation dissociates the dimers mainly to NO monomers and, in smaller proportion, to NO2 in the neon matrix or to N2O in the nitrogen matrix. NO2 is formed exclusively from the cis dimer and N2O from the trans dimer. At higher temperature in nitrogen, the oxygen atoms produced in the N2O formation migrate and react with NO to form NO2. The vibrational spectroscopy in nitrogen reveals several new features. The symmetrical vibrational mode of planar trans-(NO)2, normally IR inactive, becomes observable at 5.8 K owing to the matrix strain. cis-(NO)2 is trapped in two sites and the energy difference between them changes abruptly around 14 K, suggesting a structural transformation in the neighborhood of the sites. Cooling at 5.8 K induces a reversible decrease of the cis dimer bands, correlated with the appearance of vdW dimer bands. In both matrices, the antisymmetric band of the cis dimer is broadened by a predissociation effect as in the gas phase. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

By highly resolved infrared absorption spectra the dependence of aggregation of NO in neon on concentration, annealing, and deposition temperature is studied in recording the intensities of monomers in two sites (1874.54 and 1877.56 cm-1), of cis-(NO)2 dimers in the symmetrical (around 1866 cm-1) and antisymmetrical (around 1780 cm-1) mode, of a special dimer around 1858 cm-1 and a series of monomer side bands shifted by about 0.3, 0.6, and 1.8 cm-1 due to coupling of molecules at different lattice sites. The dimer bands also exhibit a fine structure and a broad background caused by larger aggregates. The almost statistical size distribution at low concentration and condensation temperature changes to a preferential aggregation at higher concentration (>=2×10-3) and condensation temperature (≥7 K) and the irreversible aggregation by diffusion at elevated temperatures is followed on a time scale of hours. A reversible conversion of special dimers at 1778.67 and 1865.48 cm-1 to a dimer at 1857.93 cm-1 is accelerated by lowering the temperature and attributed to a martensitic hcp to fcc phase transition. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To determine whether excessive alcohol consumption increases the risk for intensive care unit (ICU)-acquired bacterial infection, especially ventilator-associated pneumonia (VAP), in nontrauma patients. DESIGN: Prospective observational cohort study. SETTING: A 21-bed polyvalent ICU in a university hospital. PATIENTS: A total of 358 adult patients admitted over a 1-yr period who had an ICU stay > or = 3 days and in whom alcohol consumption could be assessed. INTERVENTIONS: None. MEASUREMENTS AND MEAN RESULTS: Thirty-one percent of the patients (111 of 358) were identified as at-risk drinkers according to the National Institute on Alcohol Abuse and Alcoholism criteria. Among these, 61 had a daily intake of five or more drinks per day and 73 had Simplified Michigan Alcohol Short Test scores > or = 3. ICU-acquired bacterial infections were diagnosed in 88 patients, and 69 patients had one or more VAPs. Forty (36%) at-risk drinkers acquired bacterial infections vs. 48 (19%) not-at-risk drinkers (p < .001). Among at-risk drinkers, the proportion of patients who developed bacterial infection was higher in at-risk drinkers consuming five or more drinks per day compared with at-risk drinkers consuming fewer than five drinks per day (p = .048). After adjustment for age, gender, Simplified Acute Physiology Score II, length of hospital stay before ICU admission, prior antibiotic administration within 24 hrs before ICU admission, type of admission, immunosuppression, duration of mechanical ventilation, and central venous and urinary catheter exposure, at-risk drinking remained significantly associated with the acquisition of bacterial infection at any site (hazard ratio 1.92; 95% confidence interval, 1.17-3.14; p = .009) and of VAP (hazard ratio 1.76; 95% confidence interval, 1.05-3.06; p = .04). CONCLUSIONS: At-risk drinking was a significant risk factor for acquisition of ICU-acquired bacterial infection. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Chemokines such as CCL2/monocyte chemotactic protein 1 (MCP-1) play a key role in leukocyte migration and are potential targets in the treatment of chronic inflammatory disorders. The objective of this study was to evaluate the effects of human anti-CCL2/MCP-1 monoclonal antibody (ABN912) treatment in patients with rheumatoid arthritis (RA). METHODS: Patients with active RA were enrolled in a randomized, placebo-controlled, dose-escalation study of ABN912. Infusions were administered on day 1 and day 15. In the dose-escalation phase, 4 cohorts of 8 patients each underwent serial arthroscopic biopsy of synovial tissue. Immunohistochemistry and digital image analysis were used to characterize biomarkers in synovial tissue. Laboratory evaluation included pharmacokinetic analysis and immunotypic studies of peripheral blood mononuclear cells. To assess the clinical effects of treatment with ABN912, an additional 21 patients were treated with the highest dose tolerated. RESULTS: The total study population comprised 45 patients: 33 patients received ABN912, and 12 patients received placebo. ABN912 treatment was well tolerated. Unexpectedly, there was a dose-related increase in ABN912-complexed total CCL2/MCP-1 levels in peripheral blood, up to 2,000-fold. There was no detectable clinical benefit of ABN912 compared with placebo, nor did treatment with the study drug result in a significant change in the levels of biomarkers in synovial tissue and peripheral blood. CONCLUSION: ABN912 treatment did not result in clinical or immunohistologic improvement and may have been associated with worsening of RA in patients treated with the highest dose. The results might be related to the greatly increased level of total CCL2/MCP-1 in serum that was observed following treatment with ABN912. This observation may be relevant for a variety of antibody-based therapies. [ABSTRACT FROM AUTHOR]