Peribronchial lymphocyte activation in bleomycin-induced lung injury

The role of lymphocytes in bleomycin (Bleo)-induced lung injury remains obscure. In normal hamsters, peribronchial lymphatic tissue (PBLT) has been found to contain a large population of T lymphocytes responsive to interleukin 2 (IL-2) but not to IL-4. Lung injury induced by a single intratracheal instillation of Bleo in hamsters has been ameliorated by cyclosporin A (CyA). In the present study, using this model, PBLT-derived lymphocyte function was explored for 28 days after Bleo instillation. Increase in PBLT lymphocytes occurred at five time points investigated, reaching highest values on day +7 (p < 0.0025). Cell proliferation in response to concanavalin A was enhanced, while IL-2 +/- the mitogen had no effect. In contrast to its inactivity in the normal hamster, in the Bleo-injured animal IL-4 alone induced T cell proliferation (p = 0.0077) on day +7. CyA therapy initially suppressed and delayed recovery of the number of lymphocytes and their activation. The results of this study suggest the existence of a vulnerable period in Bleo-induced lung injury and indicate that lymphocytes participate in the pathogenesis of the insult to the tissue. The unresponsiveness to IL-2 and the emergence of cellular response to IL-4 indicate immune deviation in PBLT-derived T cells.     

Validation and test issues related to noise induced by parasitic inductances of VLSI interconnects

Shows the results of studies of noise induced by various combinations of parasitic capacitances and inductances. Interconnects are simulated with parameters obtained from a 0.18 /spl mu/m process. The four kinds of noise addressed are (i) crosstalk pulse; (ii) crosstalk speedup and slowdown; (iii) oscillatory noise; (iv) combination of oscillatory noise and crosstalk pulse. The crosstalk effects induced by a combination of mutual capacitance and mutual inductance can be larger than those induced by mutual capacitance alone, even if capacitive crosstalk dominates. For certain interconnects that are capacitively and inductively coupled, transitions in the same direction on an aggressor and victim line can cause speedup or slowdown, depending on timing parameters. A similar observation holds for transitions in opposite directions. We also observe that oscillatory noise can combine with crosstalk pulse under certain skew conditions and give rise to a large magnitude of noise. We show that inductance induced noise can be a problem in medium length interconnects. Because such interconnects can occur in combinational logic blocks, the generation of suitable vectors for test and validation of such logic blocks is of concern.     

Microfluidic pump powered by self-organizing bacteria

Results are presented that demonstrate the successful use of live bacteria as mechanical actuators in microfabricated fluid systems. The flow deposition of bacteria is used to create a motile bacterial carpet that can generate local fluid motion inside a microfabricated system. By tracking the motion of tracer particles, we demonstrate that the bacterial cells that comprise the carpet self-organize, generating a collective fluid motion that can pump fluid autonomously through a microfabricated channel at speeds as high as 25 microm s(-1). The pumping performance of the system can also be augmented by changing the chemical environment. The addition of glucose to the working buffer raises the metabolic activity of the bacterial carpet, resulting in increased pumping performance. The performance of the bacterial pump is also shown to be strongly influenced by the global geometry of the pump, with narrower channels achieving a higher pumping velocity with a faster rise time.     

Biocatalytic and Structural Properties of a Highly Engineered Halohydrin Dehalogenase

Two highly engineered halohydrin dehalogenase variants were characterized in terms of their performance in dehalogenation and epoxide cyanolysis reactions. Both enzyme variants outperformed the wild‐type enzyme in the cyanolysis of ethyl (S)‐3,4‐epoxybutyrate, a conversion yielding ethyl (R)‐4‐cyano‐3‐hydroxybutyrate, an important chiral building block for statin synthesis. One of the enzyme variants, HheC2360, displayed catalytic rates for this cyanolysis reaction enhanced up to tenfold. Furthermore, the enantioselectivity of this variant was the opposite of that of the wild‐type enzyme, both for dehalogenation and for cyanolysis reactions. The 37‐fold mutant HheC2360 showed an increase in thermal stability of 8 °C relative to the wild‐type enzyme. Crystal structures of this enzyme were elucidated with chloride and ethyl (S)‐3,4‐epoxybutyrate or with ethyl (R)‐4‐cyano‐3‐hydroxybutyrate bound in the active site. The observed increase in temperature stability was explained in terms of a substantial increase in buried surface area relative to the wild‐type HheC, together with enhanced interfacial interactions between the subunits that form the tetramer. The structures also revealed that the substrate binding pocket was modified both by substitutions and by backbone movements in loops surrounding the active site. The observed changes in the mutant structures are partly governed by coupled mutations, some of which are necessary to remove steric clashes or to allow backbone movements to occur. The importance of interactions between substitutions suggests that efficient directed evolution strategies should allow for compensating and synergistic mutations during library design.     

Determination of primary, secondary, and tertiary amines in air by direct or diffusion sampling followed by determination with liquid chromatography and tandem mass spectrometry

Two different methods for sampling of primary, secondary, and tertiary aliphatic and aromatic amines in air have been developed for improving amine analysis in air. The aim was to have a quick method for direct sampling of amines at defined times, for example, for material testing as well as for long-term measurements of amines by diffusive sampling during field studies without sampling instrumentation. The goal of the study was chemical analysis of amines, especially focusing on an analytical method suitable for tertiary amines besides primary and secondary amines. For both direct and diffusive sampling, samplers working with phosphoric acid impregnated glass wool for trapping of amines by formation of quaternary ammonium salts have been designed and tested. Direct sampling was applied for in-car emission measurement and for polyurethane exhalation monitoring by drawing air from 1 m3 test chambers through amine sampling devices. Diffusive sampling was applied for the same in-car measurement and for field measurement at a landfill leachate uptake with an obnoxious smell. Quantification of sampled analytes was achieved by LCMS/MS analysis.     

Experimental detection of laminar‐turbulent transition on a rotating wind turbine blade in the free atmosphere

This paper discusses the findings from a measurement campaign on a rotating wind turbine blade operating in the free atmosphere under realistic conditions. A total of 40 pressure sensors together with an array of 23 usable hot‐film sensors (based on constant temperature anemometry) were used to study the behavior of the boundary layer within a specific zone on the suction side of a 30 m diameter wind turbine at different operational states. A set of several hundreds of data sequences were recorded. Some of them show that under certain circumstances, the flow may be regarded as not fully turbulent. Accompanying Computational Fluid Mechanics (CFD) simulations suggest the view that a classical transition scenario according to the growth of so‐called Tollmien–Schlichting did not apply. Copyright © 2016 John Wiley & Sons, Ltd.