Acute On‐Chip HIV Detection Through Label‐Free Electrical Sensing of Viral Nano‐Lysate

Development of portable biosensors has broad applications in environmental monitoring, clinical diagnosis, public health, and homeland security. There is an unmet need for pathogen detection at the point‐of‐care (POC) using a fast, sensitive, inexpensive, and easy‐to‐use method that does not require complex infrastructure and well‐trained technicians. For instance, detection of Human Immunodeficiency Virus (HIV‐1) at acute infection stage has been challenging, since current antibody‐based POC technologies are not effective due to low concentration of antibodies. In this study, we demonstrated for the first time a label‐free electrical sensing method that can detect lysed viruses, i.e. viral nano‐lysate, through impedance analysis, offering an alternative technology to the antibody‐based methods such as dipsticks and Enzyme‐linked Immunosorbent Assay (ELISA). The presented method is a broadly applicable platform technology that can potentially be adapted to detect multiple pathogens utilizing impedance spectroscopy for other infectious diseases including herpes, influenza, hepatitis, pox, malaria, and tuberculosis. The presented method offers a rapid and portable tool that can be used as a detection technology at the POC in resource‐constrained settings, as well as hospital and primary care settings.     

Bimetallic nickel-based nanocatalysts for hydrogen generation from aqueous hydrazine borane: Investigation of iron,cobalt and palladium as the second metal

Herein we present and discuss the catalytic activity results of nickel-based bimetallic nanoparticles towards the two-step dehydrogenation of hydrazine borane N₂H₄BH₃. Cobalt, iron and palladium were chosen as the second metal, and a series of Ni_1−xM_x nanocatalysts were prepared by surfactant-aided co-reduction method. The challenge was to find a nanocatalyst that is active in the decomposition of the N₂H₄ moiety of hydrazine borane. Of the 14 Ni_1−xM_x combinations, the best results were achieved with Ni_0.7Fe_0.3 and Ni_0.7Pd_0.3. At 50 °C, 3.9 and 4.3 mol H₂ + N₂ per mole of N₂H₄BH₃ were measured, indicating an activity in the decomposition of the N₂H₄ moiety. Then, both nanocatalysts were characterized by XRD, SEM, EDX, TEM, SAED and XPS. Finally, the differences in catalytic activity were discussed in terms of electronic and geometric effects.     

Effect of different dentin adhesives and application modes on sealing ability of amalgam restorations

Purpose: The aim of the study was to evaluate the sealing ability of bonded amalgam restorations using different adhesive materials with different adhesive application methods including amalgam bonding application. Materials and methods: The prepared Class-V cavities were randomly assigned to four application groups of four tested dual-curing dentin adhesives (Scotchbond Multi-Purpose Plus, XP Bond, Xeno IV and Clearfil Liner Bond 2V), dual-curing resin-based cement (Panavia F2.0) and a control group (unlined amalgam). Group 1 adhesives were applied according to the instructions for direct light-curing, Group 2 chemical-curing mode was applied according to the manufacturer’s amalgam bonding instructions. Group 3 adhesives were first applied in light-curing mode, and then amalgam bonding adhesive was applied. Group 4 adhesives were first applied in chemical-curing mode, followed immediately by light-curing mode. After that, amalgam adhesive parts were applied; then, the amalgam was condensed and carved. After storage for 24 h in distilled water at 37 °C, restorations were finished and polished. The teeth were then thermocycled (500 cycles between 5 and 55 °C), and the specimens were examined for microleakage using methylene blue as a marker. Results: Compared to the control group, the adhesive application modes significantly reduced microleakage for both dentin and enamel margins (p < 0.05). In dentin margins of the adhesives tested, Group 4 showed the lowest leakage score. On the enamel margins for Scotchbond Multi-Purpose Plus and XP Bond, Group 1 showed the highest microleakage (p < 0.05). Conclusion: According to marginal sealing ability and ease of application, Group 2 was recommended for the etch and rinse systems, and Group 4 was also recommended for the self-etch systems under amalgam restorations.     

The influence of retention hole and adhesive systems on the shear bond strengths of resin composite to amalgam

The aim of the study is to evaluate the influence of surface-treatment methods with and without the use of a retention hole on the shear bond strength of a resin composite adhered to amalgam using an adhesive system. Amalgam specimens were divided into six groups. Group 1 (Bur) specimens were roughened with a diamond bur, Group 2 (Al₂O₃) specimens were sandblasted with a 50?μm aluminum oxide powder, Group 3 (CoJet^®) specimens were sandblasted with 30?μm CoJet^® Sand, Group 4 (Bur?+?Rh) specimen surfaces were prepared with a retention hole 1?mm in diameter and 1?mm deep and roughened with a diamond bur, Group 5 (Al₂O₃?+?Rh) specimens were also prepared with a retention hole and sandblasted with 50?μm aluminum oxide powder, and Group 6 (CoJet^®?+?Rh) surfaces were prepared with a retention hole and sandblasted with 30?μm CoJet^® Sand. Resin composite cylinders were bonded onto the amalgam surfaces using Xeno^® IV, Optibond? All-In-One, Clearfil? SE Bond, Adper? Single Bond Plus, and Scotchbond? Multi-Purpose adhesive systems. In addition, silane (Monobond S) was used for Groups 5 and 6. The shear bond was determined and statistically analyzed using two-way analysis of variance and post hoc Tukey’s tests (p?≤?0.05). The surface treatment significantly affected the shear bond strengths of the adhesive systems. The shear bond strengths of Optibond? All-In-One (2.661?±?0.48?MPa) in Group 1 and Scotchbond Multi-Purpose (3.818?±?0.98) in Group 4 were significantly higher than those of the other adhesive systems. Silica coating of the amalgam surface significantly improved the shear bond strength of the resin composites. The addition of a retention hole on the amalgam affects the bonding strength of the composite adhesion.     

Drying of grape pomace with a double pass solar collector

This study aims to analyze the performance of a novel design of the double pass solar air collector (DPSAC)-assisted drying system and investigate the drying kinetics of grape pomace which is an agricultural by-product. The samples were dried to a moisture content of 0.01?g water/g dry matter between 100 and 250?min depending on the weather conditions. The average thermal efficiencies of DPSAC were calculated as 79.77, 79.85, and 69.46%. Average values of the coefficient of performance of DPSAC were determined as 5.32, 5.13, and 4.32. The highest specific moisture extraction rate value was achieved as 617.18?g water/kWh. Whereas the mass transfer coefficient (h_m) values ranged from 9.15E?11 to 1.04E?7?m/s, the effective moisture diffusivity (D_e) values were obtained between 3.04E?13 and 1.02E?10?m²/s. The qualitative analysis showed that the drying using DPSAC may be an alternative for drying applications in terms of short drying time and energy usage. Nevertheless, these results clearly suggest a complex and effective interplay between thermal performance and drying kinetics.     

Hydrogen release from aqueous hydrazine bisborane

Aqueous hydrazine bisborane H₃BN₂H₄BH₃ (HBB) might be a possible liquid-state chemical H storage material at the conditions that the compound totally dehydrogenates in mild conditions. Herein we demonstrate such a potential. We report for the first time a work about the dehydrogenation of aqueous HBB. The compound is not stable in water. Its stability is even lower in alkaline conditions because of the likely formation of the unstable intermediate [H₃BOH]^?. The use of a metal-based catalyst accelerates the hydrolysis of the BH₃ groups but the bimetallic NiPt catalyst is more active, being also able to decompose the N₂H₄ moiety. The best kinetics is observed at 70 °C and in alkaline conditions. However, the dehydrogenation is not total, reaching a limit of 80% of conversion. Unfortunately the reason of that is not understood yet. As things stand, there are some challenges ahead, but HBB has shown to be a possible liquid-state chemical H storage material.     

Aqueous hydrazine borane N2H4BH3 and nickel-based catalyst: An effective couple for the release of hydrogen in near-ambient conditions

Nickel-based bimetallic catalysts were screened using the sodium borohydride NaBH₄ hydrolysis and the aqueous hydrazine borane N₂H₄BH₃ dehydrogenation. A total of 22 bimetallic catalysts were synthesized according to an easy process while focusing on metals like Fe, Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt and Au. In the end, the bimetallic candidate Ni_87.5Pt_12.5 showed to be the most active and the most selective for the dehydrogenation of N₂H₄BH₃. At 70?°C, it is able to decompose N₂H₄BH₃ into 5.8 equivalents of H₂+N₂ in less than 12?min such as: N₂H₄BH₃?+?3H₂O?→?0.95 N₂?+?0.1 NH₃?+?B(OH)₃?+?4.85H₂. Durability and stability tests were also performed. In our conditions, Ni_87.5Pt_12.5 was found to suffer from small loss of performance because of an electronic evolution of the catalytic surface leading to modified sorption properties of the catalytic sites. Our main results are reported and discussed herein.