New opportunities for the study of organic films applied on metals for corrosion protection by means of alternating current scanning electrochemical microscopy

A new method for the investigation of the inhibition efficiency against corrosion by organic films adsorbed on metals based on the measurement of Z-approach curves by AC-SECM is proposed. Preliminary measurements conducted on four copper-inhibitor systems exposed to aqueous solutions support that a characteristic frequency can be defined, which corresponds to the frequency of the AC potential signal applied to the SECM tip for which a transition between negative- and positive-feedback behaviours is observed in the approach curves. From the shift of this characteristic frequency towards higher values, the enhancement of the corrosion protection efficiency of the inhibitor system can be established. Furthermore, the effects of inhibitor nature, concentration, and pre-treatment duration for the formation of the surface films, can be readily investigated.     

Eco-sustainable routing in optical networks

It is quite easy to foresee that in the next years, the future generation ultra-high speed network infrastructures and equipments will be no longer constrained only by their pure transport capacity, but also by their energy consumption costs and environmental effects. In particular, large network infrastructures are now widely recognized to play a fundamental role in the emission of greenhouse gases in the atmosphere, significantly affecting the environmental sustainability of new evolutions in network architectures as well as technological developments in communication devices. In this paper, a novel eco-sustainable routing and wavelength assignment algorithm, based on shortest path routing with an adaptive link weighting function relying on an extension of the OSPF-TE protocol to convey carbon footprint information, has been proposed to decrease the network ecological impact while balancing the traffic load and maintaining acceptable connection-blocking rate. The trade-off between load balancing and carbon footprint is also analyzed to evaluate the effectiveness of the proposed strategy within the context of a real world network.     

Crystallization of nanocomposites of an isotactic random butene-1/ethylene copolymer and layered double hydroxide

The effect of the presence of a layered double hydroxide (LDH) nanofiller on the crystallization behavior of a random isotactic butene-1/ethylene copolymer was investigated. Addition of LDH enhanced heterogeneous nucleation of the ordering process of the polymer matrix leading to an increase of the temperature of formation of the Form II mesophase on cooling the melt. Consequently, the size of spherulites of the polymer matrix was markedly reduced in the nanocomposites. In contrast, the Form II mesophase–Form I crystal phase transition kinetics and the final crystallinity were not affected by the presence of LDH. Addition of the LDH nanofiller led to a beneficial increase of the stiffness which suggests a route for compensating of the lower stiffness of the random copolymer compared to the homopolymer. Random copolymerization accelerates the disadvantageous room-temperature mesophase–crystal transition, but results in a reduction of the crystallinity. The addition of LDH counterbalances the lowering of the crystal fraction.     

Ancient road transport devices: Developments from the Bronze Age to the Roman Empire

The development of transportation systems has significantly enhanced the welfare and modernization of society. Wooden vehicles pulled by animals have been used for land transportation since the early Bronze Age. Whole-body gharries with rigid wheels pulled by oxen appeared in Crete by 2000 BC or earlier. Horses originating from the East were depicted in early Cretan seal-rings of the same period. The two-wheeled horsedrawn chariot was one of the most important inventions in history. This vehicle provided humanity its first concept of personal transport and was the key technology of war for 2000 years. Chariots of Mycenaean and Archaic Greece with light and flexible four-spoked wheels acting as spring suspensions were depicted in vase paintings. The development of this vehicle incorporated the seeds of a primitive design activity and was important for engineering. The Trojan horse since 1194 BC and the helepolis since 700 BC were the first known machines on a wheeled base transported by horses or self-powered. Ancient engineers invented bearings lubricated with fat, and Romans introduced the ancestors of ball bearings for their wagons and carts. The historic evolution of wheeled transportation systems, along with early traction, suspension, and braking systems, is presented in this paper. Analytical and numerical methods are incorporated to analyze the most conceivable loading situations of typically reconstructed wheeled transportation systems in ancient times. Traction requirements both for horse-driven machines and the power for internal motors are also analyzed. This study can serve as a basis for further development of detailed reconstruction of transportation systems in antiquity.     

Apple Pectic Gel Produced by Dehydration

A novel, flexible sheet-like food formed by the high methoxyl pectin–sugar–acid gelation during drying of apple puree was investigated to characterize drying-related properties. Product volume was reduced by 68% over the process, and this shrinkage was successfully modeled by assuming the volume reduction equal to the volume of water evaporated. The sorption isotherm at 25 °C was determined, and a new expression for the moisture content, W, as a function of water activity, a _w, of the type resulted as the most accurate for this J-shaped isotherm. The drying kinetics was studied at 50, 60, and 80 °C in a tray dryer. No constant drying rate period was found, and the drying curve was divided in high- and low-moisture zones. For high moistures, an internal–external mixed control diffusive model coupling mass and heat transfer was applied to obtain a mass transfer Biot number of 2.1. In the low-moisture zone, a diffusive, isothermal drying model for strict internal control was utilized. Diffusivities varied around 1 × 10–9 m²/s for high moistures and were about ten times lower at low moistures, although the activation energies were comparable (15,259 and 16,800 J/mol, respectively). The drying time at 60 °C was 6.67 h. The product scored four points out of five in a sensory evaluation of general acceptability.     

Electron tomography study of isolated human centrioles

Centrioles are components of the centrosome, which is present in most eukaryotic cells (from protozoa to mammals). They organize the microtubule skeleton during interphase and the mitotic spindle during cell division. In ciliate cells, centrioles form basal bodies that are involved in cellular motility. Despite their important roles in biology, the detailed structure of centrioles remains obscure. This work contributes to a more complete model of centriole structure. The authors used electron tomography of isolated centrosomes from the human lymphoblast KE37 to explore the details of subdistal appendages and centriole lumen organization in mother centrioles. Their results reveal that each of the nine subdistal appendages is composed of two halves (20 nm diameter each) fused in a 40 nm tip that extends 100 nm from where it anchors to microtubules. The centriole lumen is filled at the distal domain by a 45 nm periodic stack of rings. Each ring has a 30 nm diameter, is 15 nm thick, and appears to be tilted at 53 degrees perpendicular to the centriole axis. The rings are anchored to microtubules by arms. Based on their results, the authors propose a model of the mother centriole distal structure.     

HTLV-1 Infection and Pathogenesis: New Insights from Cellular and Animal Models

Since the discovery of the human T-cell leukemia virus-1 (HTLV-1), cellular and animal models have provided invaluable contributions in the knowledge of viral infection, transmission and progression of HTLV-associated diseases. HTLV-1 is the causative agent of the aggressive adult T-cell leukemia/lymphoma and inflammatory diseases such as the HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). Cell models contribute to defining the role of HTLV proteins, as well as the mechanisms of cell-to-cell transmission of the virus. Otherwise, selected and engineered animal models are currently applied to recapitulate in vivo the HTLV-1 associated pathogenesis and to verify the effectiveness of viral therapy and host immune response. Here we review the current cell models for studying virus–host interaction, cellular restriction factors and cell pathway deregulation mediated by HTLV products. We recapitulate the most effective animal models applied to investigate the pathogenesis of HTLV-1-associated diseases such as transgenic and humanized mice, rabbit and monkey models. Finally, we summarize the studies on STLV and BLV, two closely related HTLV-1 viruses in animals. The most recent anticancer and HAM/TSP therapies are also discussed in view of the most reliable experimental models that may accelerate the translation from the experimental findings to effective therapies in infected patients.     

Collagen Fibres Orientation in the Bone Matrix around Dental Implants: Does the Implant’s Thread Design Play a Role?

The aim of this study was to analyse the influence of different thread shapes of titanium dental implant on the bone collagen fibre orientation (BCFO) around loaded implants. Twenty titanium dental implants, divided for thread shapes in six groups (A–F) were analysed in the present study. All implants were immediately loaded and left in function for 6 months before retrieval. The parameters evaluated under scanning electron microscope were the thread width, thread depth, top radius of curvature, flank angle, and the inter-thread straight section. Two undecalcified histological sections were prepared from each implant. Birefringence analysis using circularly polarized light microscopy was used to quantitively measure BCFO. For groups A–F, respectively, transverse BCFO was 32.7%, 24.1%, 22.3%, 18.2%, 32.4%, and 21.2%, longitudinal BCFO was 28.2%, 14.5%, 44.9%, 33.1%, 37.7%, and 40.2%. The percentage differences between transverse and longitudinal orientation were 4.50% (A), 9.60% (B), −22.60% (C), −14.90% (D), −5.30% (E), and −19.00% (F). Following loading, the amount of transverse and longitudinal BCFO were significantly influenced by the thread shape. The greater flank angles and narrower inter-thread sections of the “V” shaped and “concave” shaped implant threads of groups A and B, respectively, promoted the predominance of transverse BCFO, compared to groups C-F (p < 0.05). A narrow inter-thread straight section promotes transverse BCFO, as do “V” shaped and “concave” shaped threads, which can thus be considered desirable design for implant threads.     

Erythroid Induction of Chronic Myelogenous Leukemia K562 Cells Following Treatment with a Photoproduct Derived from the UV‐A Irradiation of 5‐Methoxypsoralen

Induction of terminal erythroid differentiation can be an efficient strategy to inhibit proliferation of chronic myelogenous leukemia cells. Psoralens, well‐known photo‐chemotherapeutic agents, were found to be efficient at inducing erythroid differentiation of K562 cells, an in vitro cell line isolated from the pleural effusion of a patient with chronic myelogenous leukemia in blast crisis. The effects of crude pre‐irradiated solutions of 5‐methoxypsoralen on erythroid differentiation of human leukemic K‐562 cells were evaluated. The major photoproduct was characterized and analyzed, and it was found to induce erythroid differentiation of K562 cells and inhibit NF‐κB/DNA interactions.     

Monitoring of bacterial communities during low temperature thermal treatment of activated sludge combining DNA phylochip and respirometry techniques

Sludge reduction is one of the major challenges in biological wastewater treatment. One approach is to increase the sludge degradation yield together with the biodegradation kinetics. Among the various sludge pretreatment strategies proposed, thermal pretreatment at around 65 °C was described as promising. The enhancement in the biodegradation activity due to the selection of thermophilic hydrolytic bacteria was proposed, but further experiments are needed to demonstrate the specific role of these bacteria. In this study, concentrated activated sludge grown at 20 °C was subjected to thermal treatment at 65 °C for different periods. The originality of the work relied on a polyphasic approach based on the correlation between kinetics (chemical oxygen demand, COD; mixed liquor suspended solids, MLSS), bacterial activity (respirometry) and bacterial community structure (phylochip monitoring) in order to characterize the mechanisms involved in the thermal reduction of sludge. The bacterial activity in the aeration basin decreased to a very low level when recycling sludge was treated at 65 °C from 13 to 60 h, but then, started to increase after 60 h. In parallel to these fluctuations in activity, a drastic shift occurred in the bacterial community structure with the selection of thermophilic bacteria (mainly related to genera Paenibacillus and Bacillus), which are known for their specific hydrolases.