We report the mixing ratios of aerosol‐associated soluble ions (focusing on SO4= and NO3−) and HNO3 over the North Atlantic during NASA's Subsonic Assessment Ozone and Nitrogen Oxide Experiment ...(SONEX). The SONEX campaign was designed to quantify the impacts of jet emissions in the North Atlantic Flight Corridor (NAFC) by sampling both directly within and far removed from the organized track system. Beryllium‐7 activities were also measured to assess the magnitude of stratospheric influence in the SONEX study region. Mixing ratios of aerosol‐associated SO4= and NO3− above 8 km during SONEX were lower than recent measurements over the central United States during the Subsonic Aircraft Contrail and Cloud Effects Special Study (SUCCESS) and the same as those over the remote South Pacific during the Pacific Exploratory Mission‐Tropics (PEM‐Tropics), suggesting that aircraft emissions cannot yet be a major source of these ions. Furthermore, mean SO4= mixing ratios at high altitudes were 65% higher in regions away from the NAFC than they were directly in the track system just a few hours after peak traffic. Nitric acid mixing ratios at the highest DC‐8 sampling altitudes were elevated during SONEX compared to PEM‐Tropics, but there was no clear signal of enhancement by jet exhaust. Strong correlations with 7Be indicate that a large fraction of HNO3 and aerosol‐associated SO4= measured at high altitudes during SONEX were derived from a stratospheric source.
Eleven organic Lewis bases were investigated as potential ligands (L) on W6S8L‘6 clusters by exploring ligand exchange reactions to form W6S8L6 clusters. Six new homoleptic W6S8L6 cluster complexes ...were prepared and characterized with L = tri-n-butylphosphine (P n Bu3), triphenylphosphine (PPh3), tert-butylisocyanide ( t BuNC), morpholine, methylamine (MeNH2), and tert-butylamine ( t BuNH2). While partial replacement of ligands occurred with diethylamine (Et2NH) and dibutylamine (Bu2NH), homoleptic clusters could not be prepared by these exchange reactions. When aniline, tribenzylamine, and tri-tert-butylphosphine were the potential ligands, no exchange was observed. From ligand exchange studies of these ligands and others previously studied, a thermodynamic series of binding free energies for ligands on W6S8L6 clusters was established as the following: non-Lewis base solvents, aniline, P t Bu3, etc. ≪ Et2NH, Bu2NH < t BuNH2 < morpholine, piperidine ≤ n BuNH2, MeNH2 ≤ 4-tert-butylpyridine, pyridine < t BuNC < tricyclohexylphosphine (PCy3) < PPh3, P n Bu3 ≤ triethylphosphine (PEt3). Structures of the new cluster complexes were determined by X-ray crystallography. The new compounds were also characterized by NMR spectroscopy and thermogravimetric analyses (TGA). The W−L bond orders and TGA data qualitatively agree with the thermodynamic series above.
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IJS, KILJ, NUK, PNG, UL, UM
Aerosol sampling for the determination of the concentrations of soluble ionic species and the natural radionuclides super(7) Be and super(2) super(1) super(0) Pb was conducted from the NASA DC-8 over ...the western Pacific as part of GTE/PEM-West B during February-March 1994. Concentrations of most soluble ionic species in the free troposphere were higher in samples collected on flights originating from Hong Kong and Japan than those collected further east over the open ocean. In both regions the measured concentrations were higher than those found during PEM-West A (fall 1991). Activities of super(2) super(1) super(0) Pb, a tracer of air masses influenced by sources on the Asian continent, showed the same patterns. These data indicate the effect of stronger continental outflow from Asian over the western Pacific during the spring compared to fall season. For readily scavenged aerosol-associated species and soluble acidic gases the strongest indications of Asian outflow were restricted to altitudes below 6 km. The distribution of the continental tracer super(2) super(1) super(0) Pb was also compared to those of a large number of gas phase species measured on the DC-8. Relatively strong correlations were found with O sub(3) and peroxyacetylnitrate (PAN), but only during the flights over the remote Pacific. During PEM-West A, similar correlations were seen, but they were stronger near Asia. We believe that these correlations are a signature of continental air that has been processed by deep wet convection over land before being advected over the ocean. One flight over the Sea of Japan provided the opportunity to sample upper troposphere/lower stratosphere air in and around a tropopause fold. Concentrations of super(7) Be reached 7 pCi m super(-) super(3) STP, and peak O sub(3) mixing ratios of 480 ppb were encountered at 10.7 km. The super(7) Be data are used to estimate the fraction of stratospheric air mixed down into the troposphere by circulation in the fold.
We used the mist chamber/ion chromatography technique to quantify fine aerosol SO4= (<2.7 μm) in the Arctic during the Tropospheric Ozone Production about the Spring Equinox Experiment (TOPSE) with ...about 2.5 min time resolution. Our effective sample area ranged from 50° to 86°N and 53° to 100°W. The seasonal evolution of fine aerosol sulfate in the Arctic troposphere during TOPSE was consistent with the phenomenon of Arctic haze. Arctic haze has been attributed to pollution from sources in the Arctic and pollution transported meridionally along stable isentropes into the Arctic in geographically broad but vertically narrow bands. These layers became more prevalent at higher altitudes as the season progressed toward summer, and the relevant isentropes are not held so close to the surface. Mean fine particle SO4= mixing ratios during TOPSE in February below 1000 m were elevated (112 pptv) and highly variable (between 28 and 290 pptv) but were significantly lower at higher altitudes (about 40 pptv). As the season progressed, elevated mixing ratios and higher variability were observed at higher altitudes, up to 7 km. In May, mixing ratios at the lowest altitudes declined but still remained higher than in February at all altitudes. The high variability in our measurements likely reflects the vertical heterogeneity of the wintertime Arctic atmosphere as the airborne sampling platform passed in and out of these layers. It is presumed that mixing ratios and variability will continue to decline at all altitudes into the summer as wet deposition processes become important in removing aerosol SO4= from the troposphere.
An m-out-of-n:G system is composed of statistically independent and identically distributed components with exponential lifetimes. The reliability of such a system is obtained under the assumption ...that the failure of a component changes the failure rate of the surviving components.< >
This paper highlights the performance of the mist chamber/ion chromatography (MC/IC) technique for measuring atmospheric sulfur dioxide (SO2) during the Gas‐Phase Sulfur Intercomparison Experiment ...(GASIE). The technique was found to be free of interference from CO, CO2, CH4, NOx, O3, CH3SCH3, and H2O vapor. Repeated measurements at various mixing ratios of SO2 indicated that the coefficient of variation in the MC/IC measurement is 3–5% at 300–500 parts per trillion by volume (pptv), 4–7% at 150 pptv, 10% at 50 pptv, and as great as 20% near 20 pptv. In ambient air diluted five‐ to tenfold with zero air, the MC/IC technique tracked the other methods over the range of 30–3500 pptv. This agreement reinforced the conclusions obtained during the other test phases of GASIE. The MC/IC method has desirable features such as simplicity, small size, and weight of required equipment, sample integration times of 10 min or less, low pptv detection capabilities, and relatively modest implementation costs. In addition, a suite of important soluble gases can be measured simultaneously including nitric, formic, and acetic acids.
Lung transplants have been performed worldwide since the early 1980s. While numerous studies have been published on somatic aspects after lung transplantation, there is considerably less information ...available on psychosocial aspects and on the correlation between the physical and the psychosocial state of health after transplantation.
Between 1992 and 2002, 125 patients underwent lung transplantation at University Hospital Zurich. To be included into the study, patients had to have received a lung transplant > 12 months previously and to have good knowledge of the German or Italian languages. With the aid of standardized questionnaires, psychosocial variables such as levels of anxiety and depression, self-esteem, and social support were determined. In addition, self-assessments of physical and psychological health were obtained. The medical data included information on FEV1, complications such as pulmonary infections, acute or chronic allograft rejection, and assessment of the patient's physical and psychological health by the treating doctors.
The overall degree of anxiety and depression of the lung transplant recipients was comparable to standard samples of an average population. However, male lung transplant recipients were significantly more depressed than female recipients. Self-esteem was higher than in clinical comparison samples. Preceding pulmonary complications had long-lasting effects on the level of anxiety, whereas nonpulmonary complications did not have such an effect.
Overall, the psychological well-being of patients after lung transplantation is similar to the normal population. Subgroups of patients with increased psychological distress have been identified.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Our current understanding of atmospheric mercury lacks fundamental details. Gas phase elemental mercury (Hg degree ) was measured aboard the NASA DC-8 research aircraft during the Intercontinental ...Chemical Transport Experiment-Phase B (INTEX-B) conducted in spring 2006 over the North Pacific. Our data confirm efficient chemical cycling of Hg degree in the tropopause region and show that it is strongly anti-correlated with O sub(3) there, yielding a tropospheric-stratospheric mixing curve of ~- 0.20 ppqv Hg degree /ppbv O sub(3). In addition, we found frequent total depletion of Hg degree in upper tropospheric (8-12 km) air masses impacted by stratospheric influence. When O sub(3) mixing ratios were >300 ppbv, Hg degree was rarely detected. It appears that in the tropopause and stratosphere Hg degree is oxidized on the order of days followed by heterogeneous transformation to particulate mercury. These processes constitute an effective chemical sink for Hg degree at the top of the troposphere, which may recycle mercury back to the gas phase as stratospheric aerosols are eventually dispersed into the troposphere.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The objective of this study was to evaluate the feasibility of ultrasonography-guided injections of botulinum toxin A into the parotid glands of children with severe drooling (sialorrhea). Excessive ...drooling is common in children with chronic neurologic disorders. Preliminary observations in adults suggest that injections of botulinum toxin A into the parotid glands can decrease drooling, but the optimal dose, sites of injection, and concomitant use of imaging during injections and its use for children have not been established. Ultrasonography was used to guide the injection of botulinum toxin (10—25 IU) into both parotid glands of nine children with excessive drooling. Subjective and objective measures of the severity of drooling were collected before and after botulinum toxin A injections. A booster injection was provided if the initial response was inadequate. Injections were well tolerated, and no adverse reactions were observed. Ultrasonography revealed that the parotid gland showed a variable depth, extent, and vascularization. Eight of nine patients needed a booster injection after 1 month. Objective measures of drooling severity were improved in seven of nine patients. However, subjective improvement was reported in only three of nine patients, and this improvement was functionally significant in only one patient. Although intraparotid injection of botulinum toxin A is safe and causes a reduction in saliva production in children, the doses used in this study did not result in functionally significant improvement. Higher doses of botulinum toxin A in the parotid glands or concomitant injections into the submandibular glands can increase the efficacy of these injections. Variability in size, depth, and vascular supply of the parotid gland suggests the importance of ultrasonography guidance for optimizing injections. These results underscore the need for further studies to establish the efficacy of this treatment in children. (J Child Neurol 2005;20:120—123).
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
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