Copper-Catalyzed Asymmetric Reductions of Aryl/Heteroaryl Ketones under Mild Aqueous Micellar Conditions.

Enantioselective syntheses of nonracemic secondary alcohols have been achieved in an aqueous micellar medium via copper-catalyzed (Cu(OAc)·HO/()-3,4,5-MeO-MeO-BIPHEP) reduction of aryl/heteroaryl ketones. This methodology serves as a green protocol to access enantio-enriched alcohols under mild conditions (0-22 °C) using a base metal catalyst, together with an inexpensive, innocuous, and convenient stoichiometric hydride source (PMHS). The secondary alcohol products are formed in good to excellent yields with ee values greater than 90%.

Technical Note: Radiation properties of tissue- and water-equivalent materials formulated using the stoichiometric analysis method in charged particle therapy.

Purpose: Five tissue- and water-equivalent materials (TEMs) mimicking ICRU real tissues have been formulated using a previously established stoichiometric analysis method (SAM) to be applied in charged particle therapy. The purpose of this study was an experimental verification of the TEMs-SAM against charged particle beam measurements and for different computed tomography (CT) scanners. The potential of the TEMs-SAM to be employed in the dosimetry was also investigated.

Fourier power spectrum characteristics of face photographs: attractiveness perception depends on low-level image properties.

We investigated whether low-level processed image properties that are shared by natural scenes and artworks - but not veridical face photographs - affect the perception of facial attractiveness and age. Specifically, we considered the slope of the radially averaged Fourier power spectrum in a log-log plot. This slope is a measure of the distribution of special frequency power in an image.

Unprotected left main percutaneous coronary intervention in acute coronary syndromes with extracorporeal life support backup.

Background. Left main PCI is superior to coronary bypass surgery in selected patients. Registry data, however, suggest significant early adverse event rates associated with unprotected left main PCI.

Quantitative electron density characterization of soft tissue substitute plastic materials using grating-based x-ray phase-contrast imaging.

Many scientific research areas rely on accurate electron density characterization of various materials. For instance in X-ray optics and radiation therapy, there is a need for a fast and reliable technique to quantitatively characterize samples for electron density. We present how a precise measurement of electron density can be performed using an X-ray phase-contrast grating interferometer in a radiographic mode of a homogenous sample in a controlled geometry.

Socially anxious individuals discriminate better between angry and neutral faces, particularly when using low spatial frequency information.

Background And Objectives: Social anxiety is associated with biased processing of threatening faces. Earlier research indicated that socially anxious individuals are biased towards processing low spatial frequency (LSF) information when judging facial expressions. However, it remains unclear whether this bias reflects better performance for LSF-information, worse performance for high spatial frequency (HSF) information that needs to be compensated for, or both.

Intrusive images and voluntary memory for affective pictures: contextualization and dual-task interference.

Background And Objectives: The present study addressed the role of context information and dual-task interference during the encoding of negative pictures on intrusion development and voluntary recall.

Methods: Healthy participants were shown negative pictures with or without context information. Pictures were either viewed alone or concurrently with a visuospatial or verbal task.

Higher sensitivity for low spatial frequency expressions in social anxiety: evident in indirect but not direct tasks?

We tested whether socially anxious individuals perform better in processing facial information with low spatial frequencies (LSFs). For this, we presented socially anxious and nonanxious participants with hybrid face stimuli that contained independent facial expressions in high (HSF) and LSF bands. In two tasks, participants either rated the images according to "angriness" or had to learn how hybrid facial expressions predicted the location of an upcoming target.

Validating the truth of propositions: behavioral and ERP indicators of truth evaluation processes.

We investigated processes of truth validation during reading. Participants responded to 'true' and 'false' probes after reading simple true or false sentences. Compatible sentence/probe combinations (true/'true', false/'false') facilitated responding compared with incompatible combinations (true/'false', false/'true'), indicating truth validation.

A formulation of tissue- and water-equivalent materials using the stoichiometric analysis method for CT-number calibration in radiotherapy treatment planning.

Tissue- and water-equivalent materials (TEMs) are widely used in quality assurance and calibration procedures, both in radiodiagnostics and radiotherapy. In radiotherapy, particularly, the TEMs are often used for computed tomography (CT) number calibration in treatment planning systems. However, currently available TEMs may not be very accurate in the determination of the calibration curves due to their limitation in mimicking radiation characteristics of the corresponding real tissues in both low- and high-energy ranges.

Face value: eye movements and the evaluation of facial crowds in social anxiety.

Scientific evidence is equivocal on whether Social Anxiety Disorder (SAD) is characterized by a biased negative evaluation of (grouped) facial expressions, even though it is assumed that such a bias plays a crucial role in the maintenance of the disorder. To shed light on the underlying mechanisms of face evaluation in social anxiety, the eye movements of 22 highly socially anxious (SAs) and 21 non-anxious controls (NACs) were recorded while they rated the degree of friendliness of neutral-angry and smiling-angry face combinations. While the Crowd Rating Task data showed no significant differences between SAs and NACs, the resultant eye-movement patterns revealed that SAs, compared to NACs, looked away faster when the face first fixated was angry.

Task-irrelevant spider associations affect categorization performance.

In two studies, the Single Target Implicit Association Test (STIAT) was used to investigate automatic associations toward spiders. In both experiments, we measured the strength of associations between pictures of spiders and either threat-related words or pleasant words. Unlike previous studies, we administered a STIAT version in which stimulus contents was task-irrelevant: The target spider pictures were categorized according to the label picture, irrespective of what they showed.

[Digital volume tomography (DVT) and multislice spiral CT (MSCT): an objective examination of dose and image quality].

Purpose: In the last five years digital volume tomographs (DVT) have found their way into the diagnostic imaging of the facial skull. In this study both the image quality and dose of DVT and multislice spiral CT (MSCT) in this field of application were investigated using established physical methods for CT.

Materials And Methods: Measurements on DVT scanners of various manufacturers and on a modern MSCT scanner were performed.

Effects of adaptive section collimation on patient radiation dose in multisection spiral CT.

Purpose: To evaluate the potential effectiveness of adaptive collimation in reducing computed tomographic (CT) radiation dose owing to z-overscanning by using dose measurements and Monte Carlo (MC) dose simulations.

Materials And Methods: Institutional review board approval was not necessary. Dose profiles were measured with thermoluminescent dosimeters in CT dose index phantoms and in an Alderson-Rando phantom without and with adaptive section collimation for spiral cardiac and chest CT protocols and were compared with the MC simulated dose profiles.

Social anxiety and anger identification: bubbles reveal differential use of facial information with low spatial frequencies.

We investigated the facial information that socially anxious and nonanxious individuals utilize to judge emotions. Using a reversed-correlation technique, we presented participants with face images that were masked with random bubble patterns. These patterns determined which parts of the face were visible in specific spatial-frequency bands.

Modulation transfer function-based assessment of temporal resolution: validation for single- and dual-source CT.

The purpose of this study was to determine a manufacturer-independent quality assurance measurement for temporal resolution with a three-dimensional cardiac motion robot; validation was with single-source (SS) and dual-source (DS) computed tomography (CT). Image acquisition was performed by using standard cardiac protocols. Image contrast-based modulation transfer function (MTF) was assessed as function of time.

Concepts for dose determination in flat-detector CT.

Flat-detector computed tomography (FD-CT) scanners provide large irradiation fields of typically 200 mm in the cranio-caudal direction. In consequence, dose assessment according to the current definition of the computed tomography dose index CTDI(L=100 mm), where L is the integration length, would demand larger ionization chambers and phantoms which do not appear practical. We investigated the usefulness of the CTDI concept and practical dosimetry approaches for FD-CT by measurements and Monte Carlo (MC) simulations.

Technical approaches to the optimisation of CT.

This paper reviews current technical approaches to the optimisation of CT practice, i.e. approaches to reduce patient dose to the necessary minimum.