Poly[N-(2-hydroxypropyl)methacrylamide]-based tissue-embedding medium compatible with MALDI mass spectrometry imaging experiments

Traditional tissue-sectioning techniques for histological samples utilize various embedding media to stabilize the tissue on a sectioning target and to provide a smooth cutting surface. Due to the ion suppression effect in MALDI ionization and number of background peaks in the low-mass region, these media are not suitable for mass spectrometry imaging (MSI) experiments. To overcome this, droplets of water are often used to mount the tissue on a sectioning target, but the ice block formed around the tissue does not provide a good support for sectioning of fragile samples. In this work, we propose a novel embedding media, compatible with MALDI ionization and MSI experiments, based on poly[N-(2-hydroxypropyl)methacrylamide] (pHPMA). Using a reversible addition-fragmentation chain transfer polymerization technique, well-defined pHPMA polymer with narrow mass distribution was prepared. Benefits of the resulted pHPMA-based embedding media were tested on different tissue samples.     

The effect of heat treatment temperature on the interfacial shear strength of C/C composites

This paper investigates the effect of heat treatment temperature on the interfacial shear strength (IFSS) of carbon/carbon composites reinforced with polyacrylonitrile-based fibers. A series of single fiber push-out tests were performed on specimens heat treated at 1800, 2100, and 2400 °C, using a nanoindenter with a flat ended conical tip. The microstructure was characterized using polarized light and transmission electron microscopy and the debonded fiber/matrix interface was examined using scanning electron microscopy. Wavelet analysis of the load–displacement data was used as an additional tool to investigate the initiation and progression of debonding. Compared to 1800 °C, heat treatment at 2400 °C was associated with a decrease in IFSS, from 12 to 7 MPa. Transmission electron microscopy study showed that the microstructure of the fiber/matrix interphase remained amorphous even with heat treatment at 2400 °C. The decrease in the IFSS can be partly attributed to the reorganization of the graphene sheets in the matrix in the vicinity of fiber/matrix interphase. The thermal expansion mismatch between fiber and pyrocarbon matrix is another possible reason for the observed decrease in the IFSS.     

The structure of maladaptive personality traits in childhood: A step toward an integrative developmental perspective for DSM-V.

The present study describes the construction of a taxonomy of trait-related symptoms in childhood, the Dimensional Personality Symptom Item Pool (DIPSI), and examines the replicability of the taxonomy's higher order structure across maternal ratings of referred (N = 205) and nonreferred (N = 242) children and self-ratings of adolescents (N = 453). The DIPSI's 4 higher order factors--that is, Emotional Instability, Disagreeableness, Introversion, and Compulsivity--showed clear correspondence with the dimensions of personality pathology found in adulthood (Dimensional Assessment of Personality Pathology-Basic Questionnaire; W. J. Livesley, 1990; Schedule for Nonadaptive and Adaptive Personality; L. A. Clark, 1993). These 4 factors can be further organized into 2 superfactors, representing Internalizing and Externalizing Traits, demonstrating empirical and conceptual relationships with psychopathology models in childhood and adulthood. The implications for the assessment and conceptualization of early trait pathology are discussed in the context of an integrative developmental perspective on the construction of the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermodynamic Properties of He@C60

Contributions to thermodynamic properties of the endohedral He@C₆₀, resulting from motion of He inside the cage, are calculated. The contribution to C_v shows a maximum at low temperatures. The maxima for ³He@C₆₀ and ⁴He@C₆₀ are at about 41 K and 30 K, respectively.     

Contribution of staling compounds to the aged flavour of lager beer by studying their flavour thresholds

The effect of 26 staling compounds on the aged flavour of a Belgian lager beer was studied. Strikingly, thresholds were regularly found to be substantially lower than those previously reported, and it appeared important to consider threshold values as indicative rather than absolute because of very large variations in sensitivity of individuals. In addition, a masking effect of isoamyl acetate and various interactions were observed between flavour compounds, which can considerably influence their flavour activity, even at sub-threshold concentrations. Cardboard flavour was essentially caused by (E)-2-nonenal. Additionally, methional, 3-methylbutanal, 2-furfuryl ethyl ether, β-damascenone and acetaldehyde were confirmed as key contributors to the aged flavour and to a lesser extent, (E,E)-2,4-decadienal, phenylacetaldehyde, 2-methylpropanal, diacetyl and 5-hydroxymethyfurfural. Finally, the addition of a selection of compounds could fairly well reproduce the flavour of aged lager beer, indicating that these compounds account for the major part of this flavour.     

On an on-line dynamic direct coordination method in process industry

A two-level production control system based on an on-line dynamic direct coordination method is discussed. Within the structure, each local unit makes decisions keeping to the coupling outputs as recommended by the coordinator. An application to a system in process industry is given.     

Implementation of adaptive modulation as A fade countermeasure

Three key problem areas associated with implementation of the concept of adaptive modulation as a fade countermeasure in a practical VSAT system are addressed in this paper. First, the heart of such a system, an adaptive modem, is described; such a device should be able to support a number of different modulation schemes, independently for modulation and demodulation. It is shown how an adaptive modulator can be built around a VLSI numerically controlled oscillator and that an adaptive demodulator is feasible once the universal carrier tracking loop is implemented with use of digital signal processing. As regards system operation, a data transfer scenario is described which highlights that it is important to expand the set of commands and responses of the data link control protocol in order to cater for the new abilities of the system. Finally, the article describes a computer simulation of system performance evaluation under dynamic rain fading propagation conditions and applied to a K_a band link. The results confirm earlier theoretical work and show great advantage over systems using fixed modulation schemes and fixed link propagation budget margins.     

Two C60O Structures and Their Relative Stabilities: AM1 Computations

C₆₀O is studied by means of the AM1 quantum-chemical method. Full geometry optimization of its C_s and C_2v structures, and harmonic vibrational analysis, are employed in the evaluation of the temperature dependence of their relative stabilities. The C_2v structure remains a minor component of the equilibrium gas-phase mixture even at high temperatures.