Dielectrophoresis of nanoscale dsDNA and humidity effects on its electrical conductivity

The dielectrophoresis method for trapping and attaching nanoscale double-stranded DNA between nanoelectrodes was developed. The method gives a high yield of trapping single or a few molecules only which enables transport measurements at the single molecule level. Electrical conductivity of individual 140-nm-long DNA molecules was measured, showing insulating behavior in dry conditions. In contrast, clear enhancement of conductivity was observed in moist conditions, relating to the interplay between the conformation of DNA molecules and their conductivity.Comment: 4 pages, 2 figure

The short-term effect of dark chocolate flavanols on cognition in older adults: A randomized controlled trial (FlaSeCo)

Background Cocoa flavanols in the diet have had positive effects on cognition, blood lipid levels, and glucose metabolism. Methods Cognitively healthy older adults aged 65–75 years were recruited for an eight-week randomized, double-blind controlled trial to investigate the effectiveness of cocoa flavanols on cognitive functions. At baseline, nutrient and polyphenol intakes from diet were assessed with three-day food diaries. The intervention group received 50 g dark chocolate containing 410 mg of flavanols per day, and the control group 50 g dark chocolate containing 86 mg of flavanols per day, for eight weeks. Cognition was assessed with Verbal Fluency (VF) and the Trail Making Test (TMT) A and B as the main outcome measures. Changes in blood lipids and glucose were also measured. Results The older adults participating numbered 100 (63% women), mean 69 y (range 65 to 74). They were highly educated with a mean 14.9 years of education (SD 3.6). No differences in changes in cognition were seen between groups. The mean change (± SEs) in the time to complete the TMT A and B in the intervention group was −4.6 s (−7.1 to −2.1) and −16.1 s (−29.1 to −3.1), and in the controls −4.4 s (−7.0 to −1.9) and −12.5 s (−22.8 to −2.1)(TMT A p = 0.93; TMT B p = 0.66). No difference was apparent in the changes in blood lipids, glucose levels, or body weight between the groups. Conclusions The healthy older adults showed no effect from the eight-week intake of dark chocolate flavanols on cognition.Peer reviewe

Reduced Graphene Oxide-Polycarbonate Electrodes on Different Supports for Symmetric Supercapacitors

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Endostatin inhibits VEGF-A induced osteoclastic bone resorption in vitro

BACKGROUND: Endostatin is a C-terminal fragment of collagen XVIII which is a component of basement membranes with the structural properties of both collagens and proteoglycans. Endostatin has a major role in angiogenesis which is intimately associated with bone development and remodeling. Signaling between the endothelial cells and the bone cells, for example, may have a role in recruitment of osteoclastic precursor cells. Our study aims at exploring a possibility that endostatin, either as a part of basement membrane or as a soluble molecule, may control osteoclastogenesis and osteoclastic bone resorption in vitro. METHODS: Rat pit formation assay was employed in order to examine the effect of endostatin alone or in combination with vascular endothelial growth factor-A (VEGF-A) on bone resorption in vitro. Effect of these agents on osteoclast differentiation in vitro was also tested. Osteoclastogenesis and the number of osteoclasts were followed by tartrate resistant acid phosphatase (TRACP) staining and resorption was evaluated by measuring the area of excavated pits. RESULTS: Endostatin inhibited the VEGF-A stimulated osteoclastic bone resorption, whereas endostatin alone had no effect on the basal resorption level in the absence of VEGF-A. In addition, endostatin could inhibit osteoclast differentiation in vitro independent of VEGF-A. CONCLUSION: Our in vitro data indicate that collagen XVIII/endostatin can suppress VEGF-A induced osteoclastic bone resorption to the basal level. Osteoclastogenesis is also inhibited by endostatin. The regulatory effect of endostatin, however, is not critical since endostatin alone does not modify the basal bone resorption

Antiviral therapies against Ebola and other emerging viral diseases using existing medicines that block virus entry

Emerging viral diseases pose a threat to the global population as intervention strategies are mainly limited to basic containment due to the lack of efficacious and approved vaccines and antiviral drugs. The former was the only available intervention when the current unprecedented Ebolavirus (EBOV) outbreak in West Africa began. Prior to this, the development of EBOV vaccines and anti-viral therapies required time and resources that were not available. Therefore, focus has turned to re-purposing of existing, licenced medicines that may limit the morbidity and mortality rates of EBOV and could be used immediately. Here we test three such medicines and measure their ability to inhibit pseudotype viruses (PVs) of two EBOV species, Marburg virus (MARV) and avian influenza H5 (FLU-H5). We confirm the ability of chloroquine (CQ) to inhibit viral entry in a pH specific manner. The commonly used proton pump inhibitors, Omeprazole and Esomeprazole were also able to inhibit entry of all PVs tested but at higher drug concentrations than may be achieved in vivo. We propose CQ as a priority candidate to consider for treatment of EBOV

Temporal Trends in Vertebral Size and Shape from Medieval to Modern-Day

Human lumbar vertebrae support the weight of the upper body. Loads lifted and carried by the upper extremities cause significant loading stress to the vertebral bodies. It is well established that trauma-induced vertebral fractures are common especially among elderly people. The aim of this study was to investigate the morphological factors that could have affected the prevalence of trauma-related vertebral fractures from medieval times to the present day. To determine if morphological differences existed in the size and shape of the vertebral body between medieval times and the present day, the vertebral body size and shape was measured from the 4th lumbar vertebra using magnetic resonance imaging (MRI) and standard osteometric calipers. The modern samples consisted of modern Finns and the medieval samples were from archaeological collections in Sweden and Britain. The results show that the shape and size of the 4th lumbar vertebra has changed significantly from medieval times in a way that markedly affects the biomechanical characteristics of the lumbar vertebral column. These changes may have influenced the incidence of trauma- induced spinal fractures in modern populations

Structural and Electrical Characterization of Solution-Processed Electrodes for Piezoelectric Polymer Film Sensors

Solution-processable graphene and carbon nanotube-based electrode materials were used here to provide electrodes on flexible piezoelectric polyvinylidenefluoride sensors. Piezoelectric sensitivity measurements, image-based analysis, adhesion tests, and sheet resistance measurements were applied to these printable sensors to rigorously analyze their performance and structure. The printable sensors showed electrical performance similar to metallized sensors, whereas the adhesion of the solution-processed materials to the substrate is not as high as that of the evaporated metal films. This also affects the measured sensor sensitivity values. The measurements based on optical images were found to be a promising method to capture detailed information about the electrode surface structure.acceptedVersionPeer reviewe

Piezoelectric sensitivity of a layered film of chitosan and cellulose nanocrystals

Free-standing biodegradable films were fabricated by mixing cellulose nanocrystals and nanofibers with a water-based chitosan solution. The piezoelectric sensitivity of the films was measured to find out their suitability in sensing and actuation applications. Also their structure was evaluated with scanning electron microscopy. Our initial results show that a simple solvent casting method can be used to prepare films with varying piezoelectric properties. The composite films of chitosan and cellulose nanocrystals were noticed to have a phase-separated layered structure, resulting in an interesting side-dependent piezoelectric response. Moreover, the sensitivity values of plain chitosan were close to those of a non degradable commercial sensor material polyvinylidene fluoride. The fabrication process has to be studied further to control and optimize the structure and piezoelectric properties of the films.publishedVersionPeer reviewe