Electrical Conductive Properties of 3D-PrintedConcrete Composite with Carbon Nanofibers

Electrical conductive properties in cement-based materials have received attention in recent years due to their key role in many innovative application (i.e., energy harvesting, deicing systems, electromagnetic shielding, and self-health monitoring). In this work, we explore the use 3D printing as an alternative method for the preparation of electrical conductive concretes. With this aim, the conductive performance of cement composites with carbon nanofibers (0, 1, 2.5, and 4 wt%) was explored by means of a combination of thermogravimetric analysis (TGA) and dielectric spectroscopy (DS) and compared with that of specimens prepared with the traditional mold method. The combination of TGA and DS gave us a unique insight into the electrical conductive properties, measuring the specimens’ performance while monitoring the amount in water confined in the porous network. Experimental evidence of an additional contribution to the electrical conductivity due to sample preparation is provided. In particular, in this work, a strong correlation between water molecules in interconnected pores and the σ(ω) values is shown, originating, mainly, from the use of the 3D printing technique.This work was born under the umbrella of the ECRETE project (RTI2018-098554-B-I00) funded by MCIN/AEI/10.13039/501100011033 (Program I+D+i RETOS INVESTIGACIÓN 2018), the project PoroPCM (PCI2019-103657) funded by MCIN/AEI/10.13039/501100011033 and co-founded by the European Union (Programación Conjunta Internacional 2019) and the project NRG-STORAGE (GA 870114) funded by the European Commission. Research conducted in the scope of the Transnational Common Laboratory (LTC) Aquitaine-Euskadi Network in Green Concrete

Botulinum-A toxin injections into the detrusor muscle decrease nerve growth factor bladder tissue levels in patients with neurogenic detrusor overactivity

Purpose: We investigated the effects of BTX-A on visceral afferent nerve transmission by measuring bladder tissue NGF levels in patients with neurogenic detrusor overactivity before and after intravesical treatment with BTX-A. We also compared the bladder tissue NGF content with clinical and urodynamic data. Materials and Methods: A total of 23 patients underwent clinical evaluation and urodynamics with detection of the UDC threshold, maximum pressure and maximum cystometric capacity before, and at the 1 and 3-month followups. Endoscopic bladder Wall biopsies were also obtained at the same time points. NGF levels were measured in tissue homogenate by enzyme-linked immunosorbent assay (Promega, Madison, Wisconsin). Results: At 1 and 3 months mean catheterization and incontinent episodes were significantly decreased (p < 0.05 and < 0.001, respectively). On urodynamics we detected a significant increase in the UDC threshold and maximum cystometric capacity, and a significant decrease in UDC maximum pressure at the 1 and 3-month followups compared to baseline (each p < 0.001). At the same time points we detected a significant decrease in NGF bladder tissue content (each p < 0.02). Conclusions: BTX-A intravesical treatment induces a state of NGF deprivation in bladder tissue that persists at least up to 4 months. As caused by BTX-A, the decrease in acetylcholine release at the presynaptic level may induce a decrease in detrusor contractility and in NGF production by the detrusor muscle. Alternatively BTX-A can decrease the bladder level of neurotransmitters that normally modulate NGF production and release

Solvent and water retention in dental adhesive films after evaporation

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Solvent and water retention in dental adhesive blends after evaporation

This study examined the extent of organic solvent and water retention in comonomer blends with different hydrophilicity (Hoy's solubility parameter for hydrogen bonding, δh) after solvent evaporation, and the extent of tracer penetration in polymerised films prepared from these resins. For each comonomer blend, adhesive/solvent mixtures were prepared by addition of (1) 50 wt% acetone, (2) 50 wt% ethanol, (3) 30 wt% acetone and 20 wt% water and (4) 30 wt% ethanol and 20 wt% water. The mixtures were placed in glass wells and evaporated for 30-60 s for acetone-based resins, and 60-120 s for ethanol-based resins. The weight of the comonomer mixtures was measured before and after solvent evaporation. Resin films were prepared for transmission electron microscopy (TEM) after immersion in ammonical silver nitrate. The percentages of solvent and water retained in the comonomer mixtures, and between the acetone and ethanol groups were measured gravimetrically and were statistically compared. In comonomer-organic solvent mixtures, the percentage of solvent retained in acetone and ethanol-based mixtures increased significantly with hydrophilicity of the comonomer blends (P<0.05). In resin-organic solvent-water mixtures, significantly more solvent and water were retained in the ethanol-based mixtures (P<0.0001), when compared to acetone-based mixtures after 60 s of air-drying. TEM revealed residual water being trapped as droplets in resin films containing acetone and water. Water-filled channels were seen along the film periphery of all groups and throughout the entire resin films containing ethanol and water. The addition of water to comonomer-ethanol mixtures results in increased retention of both ethanol and water because both solvents can hydrogen bond to the monomers. © 2005 Elsevier Ltd. All rights reserved.postprin

In vivo and in vitro permeability of one-step self-etch adhesives

Adhesive dentistry should effectively restore the peripheral seal of dentin after enamel removal. We hypothesize that non-rinsing, simplified, one-step self-etch adhesives are effective for minimizing dentin permeability after tooth preparation procedures. Crown preparations in vital human teeth were sealed with Adper Prompt, Xeno III, iBond, or One-Up Bond F. Epoxy resin replicas were produced from polyvinyl siloxane impressions for SEM examination. Dentin surfaces from extracted human teeth were bonded with these adhesives and connected to a fluid-transport model for permeability measurements and TEM examination. Dentinal fluid droplets were observed from adhesive surfaces in resin replicas of in vivo specimens. In vitro fluid conductance of dentin bonded with one-step self-etch adhesives was either similar to or greater than that of smear-layer-covered dentin. TEM revealed water trees within the adhesives that facilitate water movement across the polymerized, highly permeable adhesives. Both in vitro and in vivo results did not support the proposed hypothesis.published_or_final_versio

Effect of some factors of variability on carcass weight of organically reared beef.

..Introduction - During the last few years, organic production has showed an increasing trend. This trend is mainly due to the EU supporting policy, in order to guarantee food security and sustainable productions for the future. In addition, since the nineties, producers and consumers have shown a growing interest towards organic production and the market have been developed. Moreover in Tuscany, a lot of farmers which own marginal land and/or forested areas have decided to turn to organic livestock, both for the ethical value of their products and for the greater bargaining power that the goods have on the market. Aim - The aim of this research was to study the effects of some variability factors on carcass weight. Materials and methods - Breed, slaughtering age, sex, season of birth, interactions year x management, breed x age and sex x age on carcass weight of 457 cattle slaughtered during the period 2001-2011 were evaluated. The animals were Chianina, Maremmana, Limousine and crossbreed Maremmana x Limousine veals and were raised in the same farm in Tuscany. The animals received the same feed and were slaughtered at an average age of 18/24 months, depending on the breed and sex. Data were stratified on the basis of the slaughtering age (five levels), then a statistical analysis was performed. Results and discussion - Chianina and crossbreed Limousine x Maremmana gave heavier carcasses: 389.3 +/- 6.39 and 323.4 +/- 5.41 kg, respectively. In general the farming system (conventional or organic) did not affect carcass weight. Chianina cattle showed a wide range of slaughtering weights. Moreover in the farm, the larger number of Chianina beef was slaughtered between 22 and 26 months like Limousine and crossbreeds, whereas Maremmana was slaughtered between 18-22 months. Males had heavier carcass than female: 353.2 +/- 4.35 vs 299.4 +/- 5.85 respectively but the differences between sexes were significant only after 18 months. The management system (conventional/organic) and the season of birth did not affect the carcass weight of cattle. Conclusion - The management system (conventional/organic) do not seem to influence the productivity, indeed it does not affect the carcass weight of beef cattle. On the other hands the choices of management play an important roles on productivity as demonstrated by the effects of the slaughter age and the breed on the carcass weight

Influence of different scanning techniques on in vitro performance of CAD-CAM-fabricated fiber posts

This study assessed push-out strength, cement layer thickness, and interfacial nanoleakage of luted fiber posts fabricated with computer-aided design/computer-assisted manufacture (CAD/CAM) technology after use of 1 of 3 scanning techniques, namely, direct scanning of the post space (DS), scanning of a polyether impression of the post space (IS), and scanning of a plaster model of the post space (MS). Thirty premolars were randomly assigned to three groups corresponding to the scanning technique. Posts were computer-designed and milled from experimental fiber-reinforced composite blocks. The mean (±SD) values for push-out strength and cement thickness were 17.1 ± 7.7 MPa and 162 ± 24 μm, respectively, for DS, 10.7 ± 4.6 MPa and 187 ± 50 μm for IS, and 12.0 ± 7.2 MPa and 258 ± 78 μm for MS specimens. Median (interquartile range) interfacial nanoleakage scores were 3 (2-4) for DS, 2.5 (2-4) for IS, and 3 (2-4) for MS. Post retention was better for fiber posts fabricated by DS technique than for those fabricated by IS and MS. Cement thickness did not differ between DS and IS specimens, but the cement layer was significantly thicker in the MS group than in the other two groups. Scanning technique did not affect sealing ability, as the three groups had comparable nanoleakage values

Incompatibility profiles of all-in-one adhesives. II. Contribution of oxygen inhibition

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