Structure of 2,2,5,5,6,6,9,9-octamethyl-2,5,6,9-tetrasiladecane,a structural precursor of poly[(tetramethyldisilanediyl)ethylene]

In order to obtain information for suggesting the most likely molecular and crystal structure of poly[(tetramethyldisilanediyl)ethylene] (PTMDSE) an X-ray study of the structural precursor 2,2,5,5,6,6,9,9-octamethyl-2,5,6,9-tetrasiladecane (TSD) is carried out. The TDS molecule is centrosymmetric, the CSiCCSiSiCCSiC chain having an almost planar all-trans conformation. In the crystal of TSD one can distinguish molecular layers parallel to the a b plane; the long axes of the TSD molecules form an angle of 24,4° with the layer plane; intermolecular contacts in layers are shorter, on the average, than interlayer contacts.     

Correlation of near infrared absorption and diffuse reflectance spectroscopy scattering with tissue neovascularization and collagen concentration in a diabetic rat wound healing model

The objective of this paper was to correlate optical changes of tissue during wound healing measured by near infrared (NIR) and diffuse reflectance spectroscopy (DRS) with histologic changes in an animal model. Amplitude and phase of scattered light were obtained in a diabetic rat and control model and biopsies were taken for blood vessel ingrowth and collagen concentration. NIR absorption coefficient correlated with blood vessel ingrowth over time, in both the control and diabetic animals. DRS data correlated with collagen concentration. Previous publications by this group documented only the NIR changes during the wound healing process but this is the first reported correlation with histology data. The ability to correlate DRS scattering with collagen concentration during healing is another important and novel finding. This technology may play an important role clinically in assessing the efficacy of wound healing agents in diabetics.     

Stabilization of synaptic membranes by α-tocopherol against the damaging action of phospholipases. Possible mechanism of biological action of vitamin E

Using fluorescent and ESR-spin probes, the effects of phospholipases A₂, C and D on rat brain synaptosomal membranes were investigated. It was shown that the exposure of synaptosomal membranes to phospholipases A₂, C and D results in their depolarization and an increase of the negative surface potential. In the case of phospholipases A₂ and C, these changes are associated with a decrease of the microviscosity of the membrane lipid bilayer. α-Tocopherol stabilizes synaptosomal membranes against the damaging action of the phospholipases. This stabilization consists in the reconstitution of the transmembrane potential and an increase of microviscosity of the phospholipase-treated membranes. The stabilizing effect of α-tocopherol is due to the binding of phospholipid hydrolysis products, but not to the inhibition of phospholipases. The observed stabilization of synaptosomal membranes by α-tocopherol is regarded as a possible mechanism of biological action of vitamin E on biomembranes.     

Advances in neural networks research: An introduction

The present Special Issue “Advances in Neural Networks Research: IJCNN2009” provides a state-of-art overview of the field of neural networks. It includes 39 papers from selected areas of the 2009 International Joint Conference on Neural Networks (IJCNN2009). IJCNN2009 took place on June 14-19, 2009 in Atlanta, Georgia, USA, and it represents an exemplary collaboration between the International Neural Networks Society and the IEEE Computational Intelligence Society. Topics in this issue include neuroscience and cognitive science, computational intelligence and machine learning, hybrid techniques, nonlinear dynamics and chaos, various soft computing technologies, intelligent signal processing and pattern recognition, bioinformatics and biomedicine, and engineering applications.     

Interspecies Scaling of Receptor-Mediated Pharmacokinetics and Pharmacodynamics of Type I Interferons

Purpose  

To develop an integrated mechanism-based modeling approach for the interspecies scaling of pharmacokinetic (PK) and pharmacodynamic (PD) properties of type I interferons (IFNs) that exhibit target-mediated drug disposition (TMDD).     

Effect of self-myofascial release on myofascial pain,muscle flexibility,and strength: A narrative review

Background

Numerous techniques have been employed to treat myofascial pain syndrome. Self-myofascial release (SMFR) is a relatively new technique of soft tissue mobilization. The simplicity and portability of the SMFR tools allow it to be easily implemented in any type of fitness or rehabilitation program. It is an active method and can be used by anyone at home or at the workplace.

The role of the nasal region in craniofacial growth: An investigation using path analysis

This study focuses on the role of the nasal region and its interactions with adjacent facial elements during early ontogeny. A series of linear measurements, areas and volumes were extracted from a collection of 227 medical CT-scans of children from 0 to 6 years of age. These measurements describe aspects of the form of the orbit, maxilla, peri-alveolar (subnasal) region, nasal area, eye, oral region, masseter, and temporal muscles. Hypothesized interactions were then examined using path analysis. Two paths were designed: the first to investigate potential interactions in, and relative contributions of the nasal derivatives and adjacent regions to overall facial growth and development; the second path sees the addition of facial soft tissue measurements and aims to assess their effects on skeletal components, and on overall facial growth and development. The results of the first path indicate a large contribution of the nasal and subnasal regions to facial development. This indicates that the nasal septum and the developing dentition provide an important but variable contribution to facial ontogeny during early years. This result is confirmed in the second path, where the soft tissue elements were added to the diagram. Results of the second path indicate that the soft tissues contribute only locally to the development of some skeletal elements of the face. This indicates that the contribution of skeletal components has a more direct effect on facial height than soft tissue matrices, however there are complex interactions between soft tissues and skeletal elements throughout ontogeny.     

Antibacterial properties of dermaseptin S4 derivatives with in vivo activity

Derivatives of the cytotoxic peptide dermaseptin S4 have recently emerged as potential antimicrobial agents. Here, we report on the antibacterial properties of three derivatives with improved toxicity profiles: a 28-residues K4K20-S4 and two shorter versions, K4-S4(1-16) and K4-S4(1-13). The range of MICs of K4K20-S4 against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli were, respectively, 1 to 4, 1 to 4, and 1 to 16 microg/ml. MICs of the short derivatives were rather similar or two to fourfold higher. Each of the three peptides was rapidly bactericidal in vitro, reducing the number of viable CFU of either E. coli or S. aureus by 6 log units in 30 min or less. Compared with MSI-78 or PG-1, K4-S4(1-13) was at least as potent against bacteria (assessed at two MIC multiples) but displayed lesser toxicity against human erythrocytes. Serial passage in subinhibitory concentrations led to emergence of resistance to commercial antibiotics but not to the L- or D isomer of either of the dermaseptin derivatives. The short derivatives were further investigated for antibacterial activity in vivo, using a peritonitis model of mice infected with P. aeruginosa. Naive mice in the vehicle control group exhibited 75% mortality, compared to 18 or 36% mortality in mice that received a single intraperitoneal injection (4.5 mg/kg) of K4-S4(1-16) or K4-S4(1-13), respectively. In vivo bactericidal activity was confirmed in neutropenic mice, where intraperitoneal administration of K4-S4(1-16) reduced the number of viable CFU in a dose-dependent manner by >3 log units within 1 h of exposure, and this was sustained for at least 5 h. Overall, the data suggest that dermaseptin S4 derivatives could be useful in treatment of infections, including infections caused by multidrug-resistant bacteria.