749 research outputs found
Spectral infrared hemispherical reflectance measurements for LDEF tray clamps
Infrared hemispherical reflectance measurements that were made on 58 chromic acid anodized tray clamps from LDEF are described. The measurements were made using a hemiellipsoidal mirror reflectometer with interferometer for wavelengths between 2-15 microns. The tray clamps investigated were from locations about the entire spacecraft and provided the opportunity for comparing the effects of atomic oxygen at each location. Results indicate there was essentially no dependence on atomic oxygen fluence for the surfaces studied, but there did appear to be a slight dependence on solar radiation exposure. The reflectances of the front sides of the tray clamps consistently were slightly higher than for the protected rear tray clamp surfaces
Bonding in Functionalized Aziridines: Nitrogen-15 and Carbon-13 Studies
Two isomeric pairs of cis- and trans-1-cyclohexyl-2-phenyl-3-benzoylaziridines
have been synthesized: (1) with a nitrogen-15 labelled nitrogen, and (2) with carbon-13
labelled ring carbons. The carbon-13 to X (where X=nitrogen-15, carbon-13 or
hydrogen-I) spin-spin coupling constants were measured and interpreted in terms
of stereoelectronic effects. X-ray crystallographic data (earlier determined for cisand
trans-1-cyclohexyl-2-phenyl-3-(p-toluyl)aziridines)1 appear in good agreement
with the NMR data. Bonding is discussed for the three-ring itself (NMR studies)
and for its substituents (X-ray studies). It is concluded that stereochemical interaction
of the Van der Waals type is an important determinant of aziridine bond
length. Three-ring to carbonyl hyperconjugation is correlated with stereoelectronic
interactions in the trans isomer
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PAUSED for thought? Using verbal protocol analysis to understand the situational and temporal cues in the decision-making of residential burglars
Using verbal protocol analysis (VPA) alongside semi-structured interviews, this research aimed to explicate the situational dynamics that inform the decision-making and target selection of residential burglars. Focusing on the VPA method, novel to criminological research, the paper considers the contribution of this empirical approach for studying the decision-making of offenders in situ. The findings reveal a series of cues, encapsulated in the âPAUSEDâ model, that are drawn upon by residential burglars to assess the suitability of a target; determining whether it is profitable, accessible, uninterruptible, surveillable, escapable and/or dishonourable. The PAUSED model is unpacked to articulate a collection of visual stimuli that serve to disrupt and suspend the otherwise rapid flow of target appraisal. Discussion of the strengths and limitations of the VPA method, and how it can compliment other approaches to understanding the decision-making of residential burglars, is provided
Detection and characterization of subvisible aggregates of monoclonal lgG in serum
To detect and characterize the aggregation of therapeutic monoclonal antibodies in undiluted biological fluids.
Fluorescently labeled subvisible IgG aggregates formed by applying either heat stress or by pH-shift were investigated immediately after addition to human serum, and after 24 h. Unstressed and stressed IgG formulations were analyzed by fluorescence single particle tracking, confocal laser scanning microscopy and flow cytometry.
Unstressed formulations remained free from subvisible aggregates in serum, whereas heat-stressed and pH-shift stressed formulations showed dissimilar aggregation behaviors. The aggregation profile of the heat-stressed formulation diluted in serum remained practically the same as the one diluted in buffer, even after the 24 h incubation period. The pH-shift stressed formulation had strikingly smaller and more numerous subvisible aggregates immediately after dilution in serum compared to buffer. These aggregates became noticeably larger in both diluents after 24 h, but in serum they appeared to be formed by other types of constituents than the labeled protein itself.
These results show that subvisible therapeutic protein aggregates may undergo changes in number, type and size distribution upon contact with human serum. This emphasizes the importance of analytical strategies for monitoring aggregation in undiluted biological fluids
Regional Patterns of Sea Level Change Related to Interannual Variability and Multidecadal Trends in the Atlantic Meridional Overturning Circulation
Some studies of ocean climate model experiments suggest that regional changes in dynamic sea level could provide a valuable indicator of trends in the strength of the Atlantic meridional overturning circulation (MOC). This paper describes the use of a sequence of global oceanâice model experiments to show that the diagnosed patterns of sea surface height (SSH) anomalies associated with changes in the MOC in the North Atlantic (NA) depend critically on the time scales of interest. Model hindcast simulations for 1958â2004 reproduce the observed pattern of SSH variability with extrema occurring along the Gulf Stream (GS) and in the subpolar gyre (SPG), but they also show that the pattern is primarily related to the wind-driven variability of MOC and gyre circulation on interannual time scales; it is reflected also in the leading EOF of SSH variability over the NA Ocean, as described in previous studies. The pattern, however, is not useful as a âfingerprintâ of longer-term changes in the MOC: as shown with a companion experiment, a multidecadal, gradual decline in the MOC [of 5 Sv (1 Sv ⥠106 m3 sâ1) over 5 decades] induces a much broader, basin-scale SSH rise over the mid-to-high-latitude NA, with amplitudes of 20 cm. The detectability of such a trend is low along the GS since low-frequency SSH changes are effectively masked here by strong variability on shorter time scales. More favorable signal-to-noise ratios are found in the SPG and the eastern NA, where a MOC trend of 0.1 Sv yrâ1 would leave a significant imprint in SSH already after about 20 years
Elevation of IL-6 in the allergic asthmatic airway is independent of inflammation but associates with loss of central airway function
<p>Abstract</p> <p>Background</p> <p>Asthma is a chronic inflammatory disease of the airway that is characterized by a Th2-type of immune response with increasing evidence for involvement of Th17 cells. The role of IL-6 in promoting effector T cell subsets suggest that IL-6 may play a functional role in asthma. Classically IL-6 has been viewed as an inflammatory marker, along with TNFα and IL-1ÎČ, rather than as regulatory cytokine.</p> <p>Objective</p> <p>To investigate the potential relationship between IL-6 and other proinflammatory cytokines, Th2/Th17 cytokines and lung function in allergic asthma, and thus evaluate the potential role of IL-6 in this disease.</p> <p>Methods</p> <p>Cytokine levels in induced sputum and lung function were measured in 16 healthy control and 18 mild-moderate allergic asthmatic subjects.</p> <p>Results</p> <p>The levels of the proinflammatory biomarkers TNFα and IL-1ÎČ were not different between the control and asthmatic group. In contrast, IL-6 levels were specifically elevated in asthmatic subjects compared with healthy controls (p < 0.01). Hierarchical regression analysis in the total study cohort indicates that the relationship between asthma and lung function could be mediated by IL-6. Among Th2 cytokines only IL-13 (p < 0.05) was also elevated in the asthmatic group, and positively correlated with IL-6 levels (r<sub>S </sub>= 0.53, p < 0.05).</p> <p>Conclusions</p> <p>In mild-moderate asthma, IL-6 dissociates from other proinflammatory biomarkers, but correlates with IL-13 levels. Furthermore, IL-6 may contribute to impaired lung function in allergic asthma.</p
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