Novel copolymers showing interactions of amidinium-carboxylate groups in water

Four hydrophobic amidine containing monomers N-(pyridin-2-yl)methacrylamide (3), 5-(pyridin-2-ylamino)pentyl methacrylate (7), S-5-(isopropenylcarbonyloxy)pentyl-N,N-diphenylthiourea (9) and methyl-5-guanidino-2-methacrylamidopentanoate (12) were synthesized and copolymerized with a water soluble co-monomer N,N-dimethylacrylamide (13) or N-isopropylacrylamide (22). The second component was a copolymer containing methacrylic acid (19) and 13/22. By combination of these two components the formation of amidinium-carboxylate interactions was determined by dynamic light scattering (DLS), ¹H-NMR spectroscopy and rheology measurements.     

Electronic Markets for Architects—The Architecture of Electronic Markets

In recent years there has been a move towards more cooperation in the construction industry. While the traditional practice is that the architect chooses the trades, provides the construction plan, and tells the trades what to do, a new initiative has been formed to create cooperative construction teams. Here the architect will discuss details of the construction plan with the trades concerned and all parties work cooperatively on the construction project. This means that there will be many coordination tasks and that communication plays a pivotal role. The paper presents a framework for and an implementation of an electronic marketplace to support such cooperative construction teams. It will be argued that there must be a co-design of the business system (i.e. cooperative construction teams) and the IT system (i.e. the marketplace including the search, negotiation, and fulfilment phases) for efficiently supporting small and medium-sized companies participating in cooperative teams and interacting on electronic marketplaces.     

Effects of partial volume and phase shift between fat and water in gradient-echo magnetic resonance-mammography

The signal modulations caused by partial volume effect and phase shift between fat and water signal in gradient-echo magnetic resonance mammography (GRE MR-mammography) have been calculated. Based on this, the theoretical sensitivity and specificity of GRE MR-mammography has been investigated considering different evaluation methods for the gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA)-based signal enhancement. The results show that both in- and out-of-phase sequences suffer from partial volume effects in voxels that contain both fat and water. This can decrease sensitivity to Gd-DTPA uptake in small, fat-embedded lesions or in pathology that contains fat interspersed histologically. Additionally, out-of-phase sequences can suffer from phase cancellation effects that can further decrease their sensitivity to Gd-DTPA uptake. In the worst case signal can actually decrease during Gd-DTPA influx. Determination of enhancement relative to the baseline value can decrease the specificity of GRE MR-mammography in the out-of-phase condition and decrease the sensitivity in the in-phase condition. These effects are less pronounced when enhancement is calculated relative to fat. These effects need to be understood since Gd-DTPA uptake is the prime indicator of malignancy in MR-mammography.     

Homework works if homework quality is high: Using multilevel modeling to predict the development of achievement in mathematics.

The present study examined the associations of 2 indicators of homework quality (homework selection and homework challenge) with homework motivation, homework behavior, and mathematics achievement. Multilevel modeling was used to analyze longitudinal data from a representative national sample of 3,483 students in Grades 9 and 10; homework effects were analyzed at the student and the class level simultaneously. Students who perceived their homework assignments to be well selected reported higher homework motivation, and homework behavior at both the student and the class level predicted later achievement at the class level. Homework assignments perceived to be cognitively challenging were differentially associated with achievement at the student and the class level. Students who perceived their homework to be challenging (student level) showed relatively poor performance, but homework challenge was positively related to achievement at the class level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cover Image,Volume 99, Issue 14

The cover image is based on the Short Communication Hydrolysis of chlorogenic acid in apple juice using a p-coumaryl esterase of Rhizoctonia solani by Mareike Siebert et al., https://doi.org/10.1002/jsfa.9940 .

     

The Collider Principle in Causal Reasoning: Why the Monty Hall Dilemma Is So Hard.

The authors tested the thesis that people find the Monty Hall dilemma (MHD) hard because they fail to understand the implications of its causal structure, a collider structure in which 2 independent causal factors influence a single outcome. In 4 experiments, participants performed better in versions of the MHD involving competition, which emphasizes causality. This manipulation resulted in more correct responses to questions about the process in the MHD and a counterfactual that changed its causal structure. Correct responses to these questions were associated with solving the MHD regardless of condition. In addition, training on the collider principle transferred to a standard version of the MHD. The MHD taps a deeper question: When is knowing about one thing informative about another? (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancing DPCD in Liquid Products by Mechanical Inactivation Effects: Assessment of Feasibility

The enhancement of standard dense phase carbon dioxide (DPCD) pasteurization by additional mechanical effects was assessed in this work. These effects were induced during pasteurization by the sudden depressurization in a narrow minitube. The high flow velocities, moderate pressures (40–80 bar) and low temperatures (25–45 °C) lead to intense degasification and shear stress. The inactivation of the test microorganism Escherichia coli DH5α (E. coli DH5α) was determined before and after depressurization in the minitube, representing entirely chemical DPCD via dissolved CO₂ and total inactivation comprising the effects of dissolved CO₂ and mechanical effects, respectively. Compared to conventional DPCD pasteurization, which is mostly attributed to chemical effects, the additional mechanical effects increased the inactivation efficiency considerably.     

3D‐Printed Scanning‐Probe Microscopes with Integrated Optical Actuation and Read‐Out

Scanning‐probe microscopy (SPM) is the method of choice for high‐resolution imaging of surfaces in science and industry. However, SPM systems are still considered as rather complex and costly scientific instruments, realized by delicate combinations of microscopic cantilevers, nanoscopic tips, and macroscopic read‐out units that require high‐precision alignment prior to use. This study introduces a concept of ultra‐compact SPM engines that combine cantilevers, tips, and a wide variety of actuator and read‐out elements into one single monolithic structure. The devices are fabricated by multiphoton laser lithography as it is a particularly flexible and accurate additive nanofabrication technique. The resulting SPM engines are operated by optical actuation and read‐out without manual alignment of individual components. The viability of the concept is demonstrated in a series of experiments that range from atomic‐force microscopy engines offering atomic step height resolution, their operation in fluids, and to 3D printed scanning near‐field optical microscopy. The presented approach is amenable to wafer‐scale mass fabrication of SPM arrays and capable to unlock a wide range of novel applications that are inaccessible by current approaches to build SPMs.