Smokers' responses to being addressed when smoking in an outdoor voluntary smoke-free zone: An observational study.

Introduction: Addressing smokers who smoke in a voluntary smoke-free area is vital to its successful implementation. Many people perceive barriers in addressing smokers due to fear of negative responses. Insights in actual responses are currently lacking.

Novel ATP competitive MK2 inhibitors with potent biochemical and cell-based activity throughout the series.

Optimization of our previously described pyrrolopiperidone series led to the identification of a new benzamide sub-series, which exhibits consistently high potency in biochemical and cell-based assays throughout the series. Strong inhibition of LPS-induced production of the cytokine TNFα is coupled to the regulation of HSP27 phosphorylation, indicating that the observed cellular effects result from the inhibition of MK2. X-ray crystallographic and computational analyses provide a rationale for the high potency of the series.

Discovery of selective and orally available spiro-3-piperidyl ATP-competitive MK2 inhibitors.

The identification of a potent, selective, and orally available MK2 inhibitor series is described. The initial absence of oral bioavailability was successfully tackled by moving the basic nitrogen of the spiro-4-piperidyl moiety towards the electron-deficient pyrrolepyridinedione core, thereby reducing the pK(a) and improving Caco-2 permeability. The resulting racemic spiro-3-piperidyl analogues were separated by chiral preparative HPLC, and the activity towards MK2 inhibition was shown to reside mostly in the first eluting stereoisomer.

Pulse subtraction time delay imaging method for ultrasound contrast agent detection.

Detection of contrast agent in perfused tissues has been an important research topic for many years. Currently available methods are mostly based on the strong nonlinear scattering of contrast agent microbubbles. These methods selectively extract those parts of the spectrum that show the largest difference in nonlinearity between contrast agent and tissue.

Estimating acoustic peak pressure generated by ultrasound transducers from harmonic distortion level measurement.

Pressure amplitude measurement is important for general research on ultrasound. Because it requires high accuracy, it is usually done using a hydrophone calibrated by an accredited laboratory. In this paper, a method is proposed for estimating the pressure amplitude in the ultrasound field using an uncalibrated single-element transducer and Khokhlov-Zabolotskaya-Kuznetsov simulations of the ultrasound field.

Radial modulation of microbubbles for ultrasound contrast imaging.

Over the past few years, extensive research has been carried out in the field of ultrasound contrast imaging. In addition to the development of new types of ultrasound contrast agents, various imaging methods dedicated to contrast agents have been introduced, and some of them are now commercially available. In this study, we present results of an imaging technique that is capable of detecting echoes from microbubbles and eliminating those emanating from nonoscillating structures (tissue), thereby enhancing contrast imaging.

Transfer functions of US transducers for harmonic imaging and bubble responses.

Current medical diagnostic echo systems are mostly using harmonic imaging. This means that a fundamental frequency (e.g.

Efficient quantification of the left ventricular volume using 3-dimensional echocardiography: the minimal number of equiangular long-axis images for accurate quantification of the left ventricular volume.

For quantification of the left ventricular volume from 3-dimensional echocardiograms a number of cross-sectional images are used. The goal of this study was to determine the minimum number of long-axis images necessary for accurate quantification of the left ventricular volume. A strong correlation was observed between volumes obtained from magnetic resonance imaging and 3-dimensional echocardiography using 16 equiangular images (r = 0.

A KLM-circuit model of a multi-layer transducer for acoustic bladder volume measurements.

In a preceding study a new technique to non-invasively measure the bladder volume on the basis of non-linear wave propagation was validated. It was shown that the harmonic level generated at the posterior bladder wall increases for larger bladder volumes. A dedicated transducer is needed to further verify and implement this approach.

Harmonic chirp imaging method for ultrasound contrast agent.

Coded excitation is currently used in medical ultrasound to increase signal-to-noise ratio (SNR) and penetration depth. We propose a chirp excitation method for contrast agents using the second harmonic component of the response. This method is based on a compression filter that selectively compresses and extracts the second harmonic component from the received echo signal.

Experimental evaluation of a non-linear coded excitation method for contrast imaging.

Previously, we have shown that for a single bubble, using chirps as the excitation signal improves both the linear and the non-linear response. Computer simulations of randomly distributed contrast agent bubbles show an increase of 10-13 dB in response when comparing pulse excitations with chirp excitations that have equal bandwidths and peak amplitudes. Second harmonic compression of simulated bubble echoes with chirp excitation shows low side-lobe levels and limited loss of axial resolution when compared to pulse excitation.

Nonlinear coded excitation method for ultrasound contrast imaging.

Coded excitation with compression on receive is used in medical ultrasound (US) imaging to increase signal-to-noise ratio (SNR) and penetration depth. We performed a computer simulation study to investigate if chirped pulse excitation can be applied in US contrast agent imaging to increase SNR and contrast-to-tissue ratio (CTR) and, thus, reduce contrast agent destruction and tissue harmonics. A new nonlinear compression technique is proposed that selectively compresses the second harmonic component of the response.

Simulation of circular array ultrasound transducers for intravascular applications.

The beam shape of a circular array transducer that is commonly used in intravascular ultrasound catheters was investigated in linear mode of operation. For this use, a simulation program which can simulate the radio frequency (rf)-response of a number of scatterers has been developed. The program is based on the impulse response method, which is implemented in the frequency domain.

Flow estimation using an intravascular imaging catheter.

Coronary flow assessment can be useful for determining the hemodynamic severity of a stenosis and to evaluate the outcome of interventional therapy. We developed a method for measuring the transverse flow through the imaging plane of an intravascular ultrasound (IVUS) catheter. This possibility has raised great clinical interest since it permits simultaneous assessment of vessel geometry and function with the same device.

Allelopathic interaction between a reef coelenterate and benthic algae.

We did in situ experiments to study the influence of a water-borne substance, exuded by the reef anthozoan Condylactis gigantea, on filamentous algae. Algal biomass accumulation on experimental glass slides was significantly inhibited by the exudate. Algal spores and diatoms were present in equal numbers on experimental and control slides, but the exudate inhibited germination of spores and was toxic to developing green, red and brown algae.