Carbon nanoscrolls produced from acceptor-type graphite intercalation compounds

A low-temperature wet chemistry technique for producing carbon nanoscrolls is described. The technique is based on the use of readily available acceptor-type graphite intercalation compounds. The initial graphite intercalation compound is first exfoliated to produce a suspension of graphene monolayers in ethanol which is subsequently sonicated yielding a suspension of carbon nanoscrolls. The technique does not require heating and the use of inert atmosphere thus providing an improvement compared to the previously reported methods.     

Formation and applications of stable 10 nm to 500 nm supramolecular porphyrinic materials

Nanoscaled materials of organic dyes are of interest for a variety of potential applications because of the rich photonic properties that this class of molecules can impart. One mode to form such nanoscaled materials is via self-organization and self-assembly, using reasonably well understood methods in supramolecular chemistry. But there are inherent complexities that arise from the use of organic-based supramolecular materials, including stability toward dioxygen, structural stability, and nanoarchitectures that may change with environmental conditions. Porphyrinoids have rich photonic properties yet are remarkably stable, have a rigid core, are readily functionalized, and metalation of the macrocycle can impart a plethora of optical, electronic, and magnetic properties. While there are many <10 nm porphyrinic assemblies, which may or may not self-organize into crystals, there is a paucity of 10–500 nm porphyrinic materials that can be isolated and stored. A variety of strategies towards the latter nanoscopic porphyrinic materials are discussed in terms of design, construction, and nanoarchitecture. The hierarchical structures include colloids, nanorods, nanotubes, nanorings, and nano-crystalline materials. This prolegomenon emphasizes the supramolecular chemistry, structure-stability, and structure-function relationships. The goal herein is to examine general trends and delineate general principles.     

Strong Photoacoustic Signal Enhancement by Coating Gold Nanoparticles with Melanin for Biomedical Imaging

Photoacoustics is a powerful biomedical imaging and detection technique, because it is a noninvasive, nonionizing, and low‐cost method facilitating deep tissue penetration. However, suitable contrast agents need to be developed to increase the contrast for in vivo imaging. Gold nanoparticles are often discussed as potential sonophores due to their large absorption cross‐section and their tunable plasmon resonance. However, disadvantages such as toxicity and low photoacoustic efficiency in the tissue transparency window prevail, preventing their clinical application. As a result, there remains a strong need to develop colloidal photoacoustic contrast agents which absorb in the tissue transparency window, exhibit high photoacoustic signal, and are biocompatible. Here, a facile synthetic approach is presented to produce melanin shells around various gold nanoparticle geometries, from spheres to stars and rods. These hybrid particles show excellent dispersability, better biocompatibility, and augmented photoacoustic responses over the pure melanin or pristine gold particles, with a rod‐shape geometry leading to the highest performance. These experimental results are corroborated using numerical calculations and explain the improved photoacoustic performance with a thermal confinement effect. The applicability of melanin coated gold nanorods as gastrointestinal imaging probes in mouse intestine is showcased.     

Study on chemical composition,antioxidant and anti-inflammatory activities of hot water extract from Piceamariana bark and its proanthocyanidin-rich fractions

Hot water extract (HWE) from Picea mariana (black spruce) bark was evaluated for its antioxidant and anti-inflammatory activities. HWE was fractionated into an oligomeric proanthocyanidin-rich fraction (OPF) and a polymeric proanthocyanidin-rich (PPF) fraction, and their bioactivities were also evaluated. OPF exhibited the highest antioxidant and anti-inflammatory activities. The compositions of HWE, OPF and PPF were also evaluated. OPF was richest in total polyphenol but the lowest in total proanthocyanidin (PA) content. Thiolysis coupled with HPLC-DAD has shown that the PAs of the black spruce bark were procyanidin type. The mean degrees of polymerisation (DPm) of HWE, OPF and PPF were, respectively, 6.0, 3.3 and 7.6.     

Predicting distress-induced eating with self-reports: Mission impossible or a piece of cake?

Comments on the original article, "Assessing yourself as an emotional eater: Mission impossible?" by C. Evers, D. T. D. de Ridder, and M. A. Adriaanse (see record 2009-20990-009). Results of a functional MRI study (Bohon, Stice, & Spoor, 2009) contradict the assertion that it is "impossible" to self-assess emotional eating because the self-report emotional eating scale of the Dutch Eating Behavior Questionnaire (DEBQ-em) predicted important individual differences in reward response during negative moods. Evers et al advance their argument in the context of results of four experiments where self-reported “emotional eaters” (DEBQ-em) did not eat more food during emotional encounters as compared to control conditions or “no emotional eaters.” However, the core characteristic of emotional eaters is not that they eat so much during distress (though binge eaters may do), but that they do not show the typical stress response of eating less (the typical stress response being loss of appetite because of physiological effects that mimic satiety) (Gold & Chrousos, 2002). Accordingly, the moderator effect of emotional eating during distress would be that. “No emotional eaters” eat less and “emotional eaters” eat the same or more compared to control conditions. Close inspection of the results of Evers et al reveals that their “no emotional eaters” did not show the typical stress response of eating less. This opens the possibility that the null findings of Evers et al may be simply explained by misclassification of “no emotional eaters” versus “emotional eaters” because of their use of median splits (a procedure notorious for possible misclassification of subjects into distinct groups). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interkulturelle Kompetenz in der medizinischen Praxis

Definition of the problem The issue of cultural diversity in medicine is more relevant than ever due to increased migration and pluralism. Over the past few years, both cross-cultural conflicts and the role cultural imperatives and values play in the physician-patient relationship have been a focus of public as well as scientific discourse. The question of how to provide culturally sensitive care has, therefore, become increasingly urgent. Training health care professionals in intercultural competence is a major step forward, but so far the medical field in Germany has been slow to acknowledge the significance of this topic. Arguments In this article, the authors critically analyze the different concepts of culture and the conception of culture in the medical context and advance a framework of intercultural philosophy designed to specify a culturally sensitive ethics. Subsequently, the notion of the concept of “intercultural competence” is examined, on the basis of which the authors argue that a form of competence is needed, which is founded on a constructivist approach. Furthermore, developments in medical education regarding (1) the implementation of cultural training and (2) cultural engagement in clinical ethics are illustrated. Conclusion There are many developments in the form of guidelines and training modules which provide a productive chance for collaboration between diverse scientific disciplines. At the same time, there is room for improvement in the field of education and advanced training. In order to meet the need for culturally sensitive care in German hospitals and to achieve the levels attained internationally, it is essential to build upon the programs and suggestions that are outlined in this article and create standards for hospitals and medical curricula.     

Linear-quadratic Gaussian balancing for model reduction of differential-algebraic systems

We generalise the model reduction method of linear-quadratic Gaussian balanced truncation to linear time-invariant systems governed by differential-algebraic equations. The presented method relies on the solution of generalised algebraic Riccati equations. A simple a priori error bound in the gap metric is given.     

Biogenic amines content in traditional dry fermented sausage Petrovská klobása as possible indicator of good manufacturing practice

The aim of this study was to determine the content of nine biogenic amines (tryptamine, phenylethylamine, putrescine, cadaverine, histamine, serotonin, tyramin, spermidine and spermine) and total biogenic amines in traditional dry fermented sausage Petrovská klobása at the end of drying period, as possible indicators of good manufacturing practice (GMP).Chromatographic separation of dansyl chloride derivatizated amines was completed in 8 min. Analyses were performed by HPLC-DAD on Eclipse XDB-C18 column. Tryptamine and spermine were determined in all analyzed samples, while histamine, serotonin and spermidine were not detected in any samples. Average content of individual biogenic amine ranged from 5.54 mg/kg (putrescin) to 75.1 mg/kg (tryptamine) and total content of biogenic amines varied from 77.8 mg/kg to 174 mg/kg.The results obtained in this study provided no evidence for deviations from good manufacturing practice in Petrovská klobása production.     

Picea mariana bark: A new source of trans-resveratrol and other bioactive polyphenols

The ethyl acetate soluble fraction obtained from the hot water extract of Picea mariana bark (BS-EAc(f)) has been demonstrated to have anti-inflammatory and antioxidant properties. Thus, in the current study, we isolated and characterised major compounds of this fraction by HPLC, NMR and MS analyses. On the whole, 28 compounds were identified, among which were five neolignans, seven lignans, trans-resveratrol, three phenolic acids and four flavonoids. To the best of our knowledge, 2,3-dihydro-3-(4-hydroxy-3-methoxyphenyl)-2-(hydroxymethyl)-(2S,3S)-1,4-benzodioxin-6-propanol, threo and erythro 3-methoxy-8,4'-oxyneolignan-3',4,7,9,9'-pentol, pallasiin, (±) epi-taxifolin, homovanillyl alcohol, orcinol and 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol are reported for the first time in the Picea genus. P. mariana dry bark contains at least 104μgg(-1)dw of trans-resveratrol and it could be therefore considered as a new accessible source of this molecule. This study provides novel information about the identity of major compounds present in BS-EAc(f), which is essential for the understanding of the anti-inflammatory and nutraceutical potential of this extract.     

<Emphasis Type="Italic">N</Emphasis>-Acyl Taurines are Anti-Proliferative in Prostate Cancer Cells

Endocannabinoids have been implicated in cancer development and cause heterogenous effects in tumor cells, by inducing apoptosis, reducing migration, causing anti-angiogenic activity and alterations in the cell cycle resulting in growth arrest. Recently, several novel amides of fatty acids that are structurally related to endocannabinoids have been isolated from mammalian sources, although the functions of these fatty amides are not well studied. One group of these novel fatty acid amides are the N-acyl taurines (fatty acids conjugated to the amino acid taurine). This study examined if N-acyl taurines, specifically N-arachidonoyl taurine and N-oleoyl taurine could function in a similar way to endocannabinoids and result in cell cycle alterations or growth arrest in the human prostate adenocarcinoma cell line PC-3. PC-3 cells were treated with various concentrations of N-arachidonoyl taurine and N-oleoyl taurine and cell proliferation and viability was measured using resazurin and colony formation assays. Effects of N-acyl taurines on the cell cycle was measured using FACS analysis. Treatment with N-arachidonoyl taurine and N-oleoyl taurine resulted in a significant reduction in proliferation of PC-3 cells, even at concentrations as low as 1 μM. Treatment with N-oleoyl taurine resulted in an increased number of cells in the subG1 population, suggesting apoptosis, and a lower number of cells in S-phase of the cell cycle. In summary, our results show that novel biologically active lipids, the N-acyl taurines, result in reduced proliferation in PC-3 cells.