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This study develops a simple and low-cost 3D paper-based analytical device (3D PAD) for the detection of available phosphate in soil. Epoxy resin is presented as a new hydrophobic material for low-cost mass production of PADs using the screen-printing method. An optimized concentration of epoxy resin solution is screen printed onto Whatman filter paper no. 1 in an easy one-step process to create hydrophobic patterns on PADs. The epoxy resin is air dried at room temperature, without heating or UV curing. This method delivers high reproducibility, resolution, and stability, and the epoxy resin barrier is compatible with both organic solvents and aqueous solutions. The molybdenum blue method is used in this PAD to measure phosphate in a colorimetric assay. The developed 3D PAD attains a linear range of 0.5-40 mg L

In this research, collagen hydrolysates with different average molecular weights ( Mn ¯ ) from leather collagen were chosen as raw materials. Five environmental-friendly sizing agents (SA) were prepared by cross-linking collagen hydrolysates with glycol diglycidyl ether (GDE) and further grafting them with butyl acrylate (BA) and styrene (St). Then the compound sizing agents (SGDESA-x, x = 1, 2, 3 and 4) were obtained by simple physical mixing of GDESA and starch. The surface sizing performance of GDESA and compound sizing agents were studied. The research result shows that both physical, mechanical properties and water resistance of the corrugated paper coated by GDESA were significantly improved when Mn ¯ of collagen hydrolysate was about 10,000, and its emulsion exhibited robust stability in long standing time. Furthermore, when the SGDESA-2 was used as a sizing agent, the coated corrugated paper exhibited strong water resistance, good physical and mechanical properties even after refolded for 20 times.

Paper microzone plates in combination with a noncontact liquid handling robot were demonstrated as tools for studying the stability of enzymes stored on paper. The effect of trehalose and SU-8 epoxy novolac resin (SU-8) on the stability of horseradish peroxidase (HRP) was studied in both a short-term experiment, where the activity of various concentrations of HRP dried on paper were measured after 1 h, and a long-term experiment, where the activity of a single concentration of HRP dried and stored on paper was monitored for 61 days. SU-8 was found to stabilize HRP up to 35 times more than trehalose in the short-term experiment for comparable concentrations of the two reagents, and a 1% SU-8 solution was found to stabilize HRP approximately 2 times more than a 34% trehalose solution in both short- and long-term experiments. The results suggest that SU-8 is a promising candidate for use as an enzyme-stabilizing reagent for paper-based diagnostic devices and that the short-term experiment could be used to quickly evaluate the capacity of various reagents for stabilizing enzymes to identify and characterize new enzyme-stabilizing reagents.

Introduction This study compared the bond strength, interfacial ultrastructure, and tag penetration of resin-based sealers applied to smear-free radicular dentin using 70% isopropyl alcohol as the active final rinse. Methods Eighty root canals were prepared and assigned to 2 groups (n = 40) according to the drying protocol: paper points or 70% isopropyl alcohol. Then, roots were divided into 4 subgroups (n = 10) with respect to the sealer and obturation material: AH Plus (Dentsply De Trey GmbH, Konstanz, Germany) and gutta-percha (AH/GP), Hybrid Root SEAL (Sun Medical, Tokyo, Japan) and gutta-percha (HR/GP), Epiphany SE (Pentron Clinical Technologies, Wallingford, CT) and gutta-percha (EP/GP), and Epiphany SE and Resilon (EP/RS). Roots were sectioned, and the push-out test was performed. Failure modes were examined under stereomicroscopy and sealer penetration into the dentinal tubules under scanning electron microscopy. Data were statistically analyzed by 2-way analysis of variance post hoc Tukey tests with a significant level of 5%. Results Overall, canals dried with isopropyl alcohol showed significantly higher bond strength values (2.11 ± 1.74 MPa) than with paper points (1.81 ± 1.73 MPa) (P < .05). The HR/GP group showed lower bond strength than the AH/GP group (P < .05) but higher than the EP/GP and EP/RS groups (P < .05). The most frequent type of failure was cohesive in the AH/GP and HR/GP groups and adhesive in the EP/GP and EP/RS groups. Scanning electron microscopic evaluation revealed better adaptation of the adhesive interface in the AH/GP and HR/GP groups in comparison with the EP/GP and EP/RS groups. Conclusions A final rinse with EDTA and 70% isopropyl alcohol improved the bond strength and penetration of the sealers into dentinal tubules of the root.

Introduction The purpose of this study was to evaluate the effects of intraradicular moisture conditions on the push-out bond strength of root canal sealers. Methods Eighty root canals were prepared using rotary instruments and, thereafter, were assigned to 4 groups with respect to the moisture condition tested: (1) ethanol (dry): excess distilled water was removed with paper points followed by dehydration with 95% ethanol, (2) paper points: the canals were blot dried with paper points with the last one appearing dry, (3) moist: the canals were dried with low vacuum by using a Luer adapter for 5 seconds followed by 1 paper point for 1 second, and (4) wet: the canals remained totally flooded. The roots were further divided into 4 subgroups according to the sealer used: (1) AH Plus (Dentsply-Tulsa Dental, Tulsa, OK), (2) iRoot SP (Innovative BioCeramix Inc, Vancouver, Canada), (3) MTA Fillapex (Angelus Industria de Produtos Odontologicos S/A, Londrina, Brasil), and (4) Epiphany (Pentron Clinical Technologies, Wallingford, CT). Five 1-mm-thick slices were obtained from each root sample (n = 25 slices/group). Bond strengths of the test materials to root canal dentin were measured using a push-out test setup at a cross-head speed of 1 mm/min. The data were analyzed statistically by two-way analysis of variance and Tukey tests at P = .05. Results Irrespective of the moisture conditions, iRoot SP displayed the highest bond strength to root dentin. Statistical ranking of bond strength values was as follows: iRoot SP > AH Plus > Epiphany ≥ MTA Fillapex. The sealers displayed their highest and lowest bond strengths under moist (3) and wet (4) conditions, respectively. Conclusions The degree of residual moisture significantly affects the adhesion of root canal sealers to radicular dentin. For the tested sealers, it may be advantageous to leave canals slightly moist before filling.

To assess the sealing ability of ProRoot MTA when placed as an apical barrier using three different techniques.Sixty freshly extracted single-rooted human teeth were decoronated and standardized to a root length of 15 mm. The root segments were prepared with Gates Glidden burs to simulate a divergent open apex of immature teeth and randomly assigned into three experimental groups of 20 samples each. MTA (5 mm) was placed by pluggers (Group A), paper points (Group B), or ultrasonic tips (Group C). A cotton pellet moistened with saline was placed in the root canals till the material set, and the coronal portion was sealed with Cavit. After 24 hours, the Cavit and cotton pellet were removed and the canals dried and obturated with warm guttapercha (Obtura) and AH 26 sealer. Coronal portions of all samples were then sealed with Cavit. All root segments were double-coated with nail varnish except for the open apex and were exposed to methylene blue dye for 48 hours at room temperature. The samples were sectioned longitudinally (layer thickness 0.4 mm) and the extent of dye penetration was measured with a stereomicroscope (magnification 20×).The mean depth (± standard deviation) of dye leakage for Group A was 1.34 ± 0.5 mm, Group B 1.25 ± 0.4 mm, and Group C 1.14 ± 0.4 mm. There were no significant differences among the three experimental groups (.178P.552).ProRoot MTA has a similar sealing ability when placed as an apical barrier with pluggers, paper points, or ultrasonic tips.

This work examined the efficacy of chlorine dioxide (ClO2) gas for the decontamination of Bacillus thuringiensis spores on paper, wood, epoxy, and plastic surfaces. Spores representing an inoculation level of approximately 6 log colony-forming units (CFU) per surface were treated with 5, 10, 15, 20, 25, or 30 milligrams per liter (mg/L) ClO2 gas for 12 hours under 85-92 percent relative humidity and at 22 +/- 1 degrees C. Under the tested treatment conditions, the highest population of surviving spores was found on the paper surface and the lowest was found on the plastic surface (p.05). The 5 mg/L ClO2 gas treatment inactivated 2.5, 3.6, 4.0, and 4.9 log spores per surface on paper, wood, epoxy, and plastic surfaces, respectively. A greater than 5-log reduction of spores was achieved on each surface after the 15 mg/L ClO2 gas treatment. The minimum ClO2 gas concentration needed to completely inactivate the inoculated spores was 30 mg/L for paper and wood surfaces, 25 mg/L for epoxy surfaces, and 20 mg/L for plastic surfaces. The results of this study may provide insight into the parameters of effective decontamination procedures for Bacillus spores.