scholarly journals Shelf Life and Storage Conditions of Universal Adhesives: A Literature Review

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2708
Author(s):  
Georgi Iliev ◽  
Louis Hardan ◽  
Cynthia Kassis ◽  
Rim Bourgi ◽  
Carlos Enrique Cuevas-Suárez ◽  
...  
Keyword(s):  
Shelf Life ◽  
Clinical Importance ◽  
Storage Conditions ◽  
Adhesive Systems ◽  
Hybrid Layer ◽  
Universal Adhesive ◽  
Bond Performance ◽  
Universal Adhesives ◽  
The Stability ◽  
And Storage

This paper presents state of the art universal adhesive systems and the effect of shelf-life and storage conditions on their bond performance. Three topics are explored in this review: an introduction to the topic, the mechanisms responsible for the degradation of the hybrid layer, and the factors that play a role in the stability of universal adhesives. In addition, issues such as potential durability and clinical importance are discussed. Universal adhesive systems are promising but must be handled and stored according to the manufacturer’s instructions, with careful attention given to the details of shelf-life and storage conditions for maximal success. It appears that the components of universal adhesives play an important role in their stability. Furthermore, HEMA-free formulations using methacrylamides lead to longer shelf-life. Further research is needed to prove these hypotheses.

scholarly journals High–Pressure Processing vs. Thermal Treatment: Effect on the Stability of Polyphenols in Strawberry and Apple Products

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2919
Author(s):  
Gabriela Lorena Salazar-Orbea ◽  
Rocío García-Villalba ◽  
Francisco A. Tomás-Barberán ◽  
Luis Manuel Sánchez-Siles
Keyword(s):  
High Pressure ◽  
Thermal Treatment ◽  
Shelf Life ◽  
Storage Conditions ◽  
High Pressure Processing ◽  
Negative Effects ◽  
Apple Products ◽  
Processed Products ◽  
The Stability ◽  
And Storage

Polyphenols are important bioactive compounds that are affected by processing. The consumer’s demand for minimally processed products contributes to the increase in non-thermal technologies such as high-pressure processing (HPP) in the food industry. This review is aimed at critically discussing the positive and negative effects of thermal treatment (TT) and HPP on the stability of different polyphenol families in agro-food products obtained from strawberry and apple, two of the most used fruits in food processing. Our findings show that the phenolic content was affected by processing, fruit type, polyphenol family, and storage conditions (time and temperature) of the final product. To increase shelf life, manufacturers aiming to preserve the natural content of polyphenols need to find the sweet spot between polyphenol stability and product shelf-life since the residual enzyme activity from HPP can affect polyphenols negatively.

Effect of pH and temperature on the infectivity of human coronavirus 229E

1989 ◽  
Vol 35 (10) ◽  
pp. 972-974 ◽  
Author(s):  
Alain Lamarre ◽  
Pierre J. Talbot
Keyword(s):  
Incubation Period ◽  
Storage Conditions ◽  
Viral Infectivity ◽  
Human Coronavirus ◽  
Virus Growth ◽  
The Stability ◽  
And Storage ◽  
Influence Of Ph ◽  
Human Coronavirus 229E

The stability of human coronavirus 229E infectivity was maximum at pH 6.0 when incubated at either 4 or 33 °C. However, the influence of pH was more pronounced at 33 °C. Viral infectivity was completely lost after a 14-day incubation period at 22, 33, or 37 °C but remained relatively constant at 4 °C for the same length of time. Finally, the infectious titer did not show any significant reduction when subjected to 25 cycles of thawing and freezing. These studies will contribute to optimize virus growth and storage conditions, which will facilitate the molecular characterization of this important pathogen.Key words: coronavirus, pH, temperature, infectivity, human coronavirus.

scholarly journals Pre-Drawn Syringes of Comirnaty for an Efficient COVID-19 Mass Vaccination: Demonstration of Stability

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1029
Author(s):  
Francesca Selmin ◽  
Umberto M. Musazzi ◽  
Silvia Franzè ◽  
Edoardo Scarpa ◽  
Loris Rizzello ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Real Life ◽  
Storage Conditions ◽  
Lipid Nanoparticles ◽  
Mass Vaccination ◽  
Hydrodynamic Diameter ◽  
The Us ◽  
Real Mass ◽  
The Stability ◽  
And Storage

Moving towards a real mass vaccination in the context of COVID-19, healthcare professionals are required to face some criticisms due to limited data on the stability of a mRNA-based vaccine (Pfizer-BioNTech COVID-19 Vaccine in the US or Comirnaty in EU) as a dose in a 1 mL-syringe. The stability of the lipid nanoparticles and the encapsulated mRNA was evaluated in a “real-life” scenario. Specifically, we investigated the effects of different storing materials (e.g., syringes vs. glass vials), as well as of temperature and mechanical stress on nucleic acid integrity, number, and particle size distribution of lipid nanoparticles. After 5 h in the syringe, lipid nanoparticles maintained the regular round shape, and the hydrodynamic diameter ranged between 80 and 100 nm with a relatively narrow polydispersity (<0.2). Samples were stable independently of syringe materials and storage conditions. Only strong mechanical stress (e.g., shaking) caused massive aggregation of lipid nanoparticles and mRNA degradation. These proof-of-concept experiments support the hypothesis that vaccine doses can be safely prepared in a dedicated area using an aseptic technique and transferred without affecting their stability.

Effect of Different Protocols in Preconditioning With EDTA in Sclerotic Dentin and Enamel Before Universal Adhesives Applied in Self-etch Mode

2017 ◽  
Vol 42 (3) ◽  
pp. 284-296 ◽  
Author(s):  
EC Martini ◽  
SO Parreiras ◽  
MF Gutierrez ◽  
AD Loguercio ◽  
A Reis
Keyword(s):  
Bond Strength ◽  
Adhesive Systems ◽  
Microtensile Bond Strength ◽  
Universal Adhesive ◽  
Etching Pattern ◽  
Bonding Performance ◽  
Universal Adhesives ◽  
Microshear Bond Strength ◽  
Self Etch ◽  
Main Factor

SUMMARY Objectives: The aim of this study was to investigate the effect of different protocols of 17% ethylene diamine tetra-acetic acid (EDTA) conditioning on the etching pattern and immediate bond strength of universal adhesives to enamel and sclerotic dentin. Methods and Materials: Forty bovine teeth with sclerotic dentin and 20 human third molars were randomly divided into eight groups resulting from the combination of the main factors surface treatment (none, two-minute EDTA conditioning manual application, 30-second EDTA manual application, 30-second EDTA sonic application) and adhesives systems (Scotchbond Universal Adhesive [SBU] and Prime & Bond Elect [PBE]). Resin-dentin and enamel-dentin bond specimens were prepared and tested under the microtensile bond strength (μTBS) and microshear bond strength (μSBS) tests, respectively. The etching pattern produced on the unground enamel and the sclerotic dentin surfaces under the different protocols and adhesive systems was evaluated under scanning electron microscopy. Results: For enamel, only the main factor adhesive was significant (p&lt;0.0001), with SBU showing the highest μSBS. In sclerotic dentin, the lowest mean was observed for the group without EDTA application and the highest mean in the group with EDTA application with the sonic device for 30 seconds. Regardless of the EDTA protocol, the highest means of μTBS were observed for SBU (p&lt;0.05). Conclusions: EDTA conditioning improves the bonding performance of universal adhesives in the self-etch mode on sclerotic dentin, mainly when applied for 30 seconds with the aid of a sonic device. EDTA pretreatment also improves the retentive etching pattern of enamel, but it does not result in higher enamel bond strength.

scholarly journals Influence of drying methods on preservation of biologically active substances of garden strawberries being raw material for food enrichment

2021 ◽  
Vol 845 (1) ◽  
pp. 012094
Author(s):  
I M Novikova ◽  
O M Blinnikova ◽  
L G Eliseeva ◽  
D A Blinnikova
Keyword(s):  
Shelf Life ◽  
Storage Period ◽  
Storage Conditions ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Raw Material ◽  
Drying Methods ◽  
Urgent Problem ◽  
And Storage ◽  
Active Substances

Abstract At present, the preservation of the consumer properties of berry products is an urgent problem. Use of fresh garden strawberries is limited by a short storage period and seasonality. Under optimal storage conditions in a normal atmosphere, the average shelf life of strawberries is from 2 to 9 days depending on the variety. To meet the needs of the population in garden strawberries and meet the physiological needs in a unique complex of biologically active substances, strawberries are subjected to different processing methods. Drying being a type of fruit and berry products processing has the following advantages: a significant increase in the shelf life of products, a decrease in the mass and storage volumes of dried berries, preservation of minerals, carbohydrates, dietary fiber, antioxidants, bioflavonoids and many biologically active compounds in berries. Modern drying technologies allow preserving the content of essential vitamins to its full extent. Comparison of two technologies for drying garden strawberries has established that vitamins and other biologically active substances are well preserved in berries. Berries dried by convective vacuum-impulse method (CVI) are recommended to be used for food enrichment.

scholarly journals An Assessment of Mesoporous Silica Nanoparticle Architectures as Antigen Carriers

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 294 ◽  
Author(s):  
Xinyue Huang ◽  
Helen E Townley
Keyword(s):  
Mesoporous Silica ◽  
Mesoporous Silica Nanoparticles ◽  
High Surface ◽  
Silica Nanoparticle ◽  
Storage Conditions ◽  
Surface Areas ◽  
Antigen Complex ◽  
The Stability ◽  
And Storage ◽  
Storage Temperatures

Mesoporous silica nanoparticles (MSNPs) have the potential to be used as antigen carriers due to their high surface areas and highly ordered pore network. We investigated the adsorption and desorption of diphtheria toxoid as a proof-of-concept. Two series of nanoparticles were prepared—(i) small pores (SP) (<10 nm) and (ii) large pores (LP) (>10 nm). SBA-15 was included as a comparison since this is commercially available and has been used in a large number of studies. External diameters of the particles ranged from 138 to 1509 nm, surface area from 632 to 1110 m2/g and pore size from 2.59 to 16.48 nm. Antigen loading was assessed at a number of different ratios of silica-to-antigen and at 4 °C, 20 °C and 37 °C. Our data showed that protein adsorption by the SP series was in general consistently lower than that shown by the large pore series. Unloading was then examined at 4 °C, 20 °C and 37 °C and a pH 1.2, 4.5, 6.8 and 7.4. There was a trend amongst the LP particles towards the smallest pores showing the lowest release of antigen. The stability of the MSNP: antigen complex was tested at two different storage temperatures, and storage in solution or after lyophilization. After 6 months there was negligible release from any of the particles under any of the storage conditions. The particles were also shown not to cause hemolysis.

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