In vitro digestion rate and resistant starch content of tortillas stored at two different temperatures

In vitro indicators of starch bioavailability were evaluated in freshly prepared maize tortillas and compared to those exhibited by 24, 48 or 72 h-stored samples. Storage took place either at room temperature (approx. 25 °C) or under refrigeration (4 °C). Potentially available starch (AS) content decreased from 670 g kg⁻¹ in the control tortilla to 583 g kg⁻¹ in 72 h-stored preparations. Concomitant increases in total resistant starch (RS) and retrograded resistant starch (RRS) were recorded upon storage. RRS content in 72 h-stored samples (35-39 g kg⁻¹) doubled that of freshly prepared tortillas. Changes in AS, RS and RRS were not affected by storage temperature. Both initial rate and final point of starch hydrolysis by pancreatic amylase were reduced in samples kept for 48 and 72 h, without influence of storage temperature. Storage length is suggested as a major determinant of the bioavailability of starch in tortillas.     

Molecular beam epitaxy of semipolar AlN(11\bar{2}2) and GaN(11\bar{2}2) on m-sapphire

We report on the plasma-assisted molecular-beam epitaxy of semipolar $\hbox{AlN}(11\bar{2}2)$ and GaN( $11\bar{2}2$ ) films on $(1\bar{1}00)$ m-plane sapphire. AlN deposited on m-sapphire settles into two main crystalline orientation domains, $\hbox{AlN}(11\bar{2}2)$ and $\hbox{AlN}(10\bar{1}0),$ whose ratio depends on the III/V ratio. Growth under moderate nitrogen-rich conditions enables to isolate the $(11\bar{2}2)$ orientation. The in-plane epitaxial relationships of $\hbox{AlN}(11\bar{2}2)$ on m-plane sapphire are $[11\bar{2}\bar{3}]_{\rm AlN} \vert \vert [0001]_{\rm sapphire}$ and $[1\bar{1}00]_{\rm AlN} \vert \vert [11\bar{2}0]_{\rm sapphire}.$ GaN deposited directly on m-sapphire results in ( $11\bar{2}2$ )-oriented layers with ( $10\bar{1}\bar{3}$ )-oriented inclusions. A ～100 nm-thick AlN( $11\bar{2}2$ ) buffer imposes the ( $11\bar{2}2$ )-orientation for the GaN layer grown on top. By studying the Ga-desorption on GaN( $11\bar{2}2$ ), we conclude that these optimal growth conditions corresponds to a Ga excess of one monolayer on the GaN( $11\bar{2}2$ ) surface.     

Qualitative mapping of structurally different dipeptide nanotubes

Biological self-assembled structures are receiving increasing focus within micro- and nanotechnology, for example, as sensing devices, due to the fact that they are cheap to produce and easy to functionalize. Therefore, methods for the characterization of these structures are much needed. In this paper, electrostatic force microscopy (EFM) was used to distinguish between hollow nanotubes formed by self-assembly by a simple aromatic dipeptide, L-phenylalanine, silver-filled peptide-based nanotubes, and silver wires placed on prefabricated SiO2 surfaces with a backgate. The investigation shows that it is possible to distinguish between these three types of structures using this method. Further, an agreement between the detected signal and the structure of the hollow peptide was demonstrated; however only qualitative agreement with the mathematical expressing of the tubes is shown.     

Perspectives to breed for improved baking quality wheat varieties adapted to organic growing conditions

Northwestern European consumers like their bread to be voluminous and easy to chew. These attributes require a raw material that is rich in protein with, among other characteristics, a suitable ratio between gliadins and glutenins. Achieving this is a challenge for organic growers, because they lack cultivars that can realise high protein concentrations under the relatively low and variable availability of nitrogen during the grain-filling phase common in organic farming. Relatively low protein content in wheat grains thus needs to be compensated by a high proportion of high-quality protein. Organic farming therefore needs cultivars with genes encoding for optimal levels of glutenins and gliadins, a maximum ability for nitrogen uptake, a large storage capacity of nitrogen in the biomass, an adequate balance between vegetative and reproductive growth, a high nitrogen translocation efficiency for the vegetative parts into the grains during grain filling and an efficient conversion of nitrogen into high-quality proteins. In this perspective paper the options to breed and grow such varieties are discussed.     

Light-Activated Metal Complexes that Covalently Modify DNA

Many drugs in current clinical use rely on mechanisms of action that involve damage to nucleic acids. While this has been a successful therapeutic approach for many years, the major limitation of these agents is systemic cytotoxicity, resulting from damage caused to healthy cells. Photoactive metal complexes offer the possibility of combining two successful treatment modalities for cancer and other diseases by providing DNA damage similar to that obtained with cisplatin, but in a spatially and temporally controlled manner, as with phototherapy. Recent progress in the field has provided metal complexes that can be triggered to create covalent adducts with nucleic acids both in vitro and in cells. Furthermore, several of these agents have been shown to induce cytotoxicity in cancer cell lines, in vitro tumor models, and in vivo animal models. In the last year, new compounds have been reported that can be activated with low energy light within the “therapeutic window,” where light penetration through tissue is sufficient to access larger volume tumors. This review highlights the advances that demonstrate the potential of light-activated metal complexes as therapeutics and research tools for biomedical applications.     

Peptides Derived from Vascular Endothelial Growth Factor B Show Potent Binding to Neuropilin-1

Vascular endothelial growth factors (VEGFs) regulate significant pathways in angiogenesis, myocardial and neuronal protection, metabolism, and cancer progression. The VEGF-B growth factor is involved in cell survival, anti-apoptotic and antioxidant mechanisms, through binding to VEGF receptor 1 and neuropilin-1 (NRP1). We employed surface plasmon resonance technology and X-ray crystallography to analyse the molecular basis of the interaction between VEGF-B and the b1 domain of NRP1, and developed VEGF-B C-terminus derived peptides to be used as chemical tools for studying VEGF-B - NRP1 related pathways. Peptide lipidation was used as a means to stabilise the peptides. VEGF-B-derived peptides containing a C-terminal arginine show potent binding to NRP1-b1. Peptide lipidation increased binding residence time and improved plasma stability. A crystal structure of a peptide with NRP1 demonstrated that VEGF-B peptides bind at the canonical C-terminal arginine binding site. VEGF-B C-terminus imparts higher affinity for NRP1 than the corresponding VEGF-A₁₆₅ region. This tight binding may impact on the activity and selectivity of the full-length protein. The VEGF-B₁₆₇ derived peptides were more effective than VEGF-A₁₆₅ peptides in blocking functional phosphorylation events. Blockers of VEGF-B function have potential applications in diabetes and non-alcoholic fatty liver disease.     

Discovery of a New Class of Non‐imidazole Oxazoline‐Based Histamine H3 Receptor (H3R) Inverse Agonists

H ₃ R inverse agonists based on an aminopropoxy‐phenyloxazoline framework constitute highly valuable druglike lead compounds that display efficacy in a mouse model of recognition memory.

     

Some comments on a Viennese school of psychiatry.

The author comments on a school of psychotherapy called Logotherapy or Existential Analysis, which was originated by Victor E. Frankl of the Department of Neurology and Psychiatry at the University of Vienna. This school of analysis reflects the culture of the Hitler era and post-war Europe. Frankl states that neurosis is caused by repression of the patient's sense of responsibility and the function of psychotherapy is to bring this sense of responsibility back to the patient's awareness. Happiness, he postulates, is a byproduct of the realization of other values. Fear of death, aging, and discomfort are the principal causes of anxiety. The author feels that this school of psychotherapy, which has arisen from an experiential background so different from ours is worthy of careful study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)