Topic Review
VARTM Processed Composite Materials
Fiber-reinforced composite structures are used in different applications due to their excellent strength to weight ratio. Due to cost and tool handling issues in conventional manufacturing processes, like resin transfer molding (RTM) and autoclave, vacuum-assisted resin transfer molding (VARTM) is the best choice among industries. VARTM is highly productive and cheap. However, the VARTM process produces complex, lightweight, and bulky structures, suitable for mass and cost-effective production, but the presence of voids and fiber misalignment in the final processed composite influences its strength. Voids are the primary defects, and they cannot be eliminated completely, so a design without considering void defects will entail unreliability. Many conventional failure theories were used for composite design but did not consider the effect of voids defects, thus creating misleading failure characteristics.
  • 1154
  • 07 Apr 2021
Topic Review
Natural Biopolymers
Natural biopolymers are an interesting resource for edible films production, as they are environmentally friendly packaging materials.
  • 1125
  • 23 Jun 2021
Topic Review
Water-Soluble Photoinitiators in Biomedical Applications
Light-initiated polymerization processes are currently an important tool in various industrial fields. The advancement of technology has resulted in the use of photopolymerization in various biomedical applications, such as the production of 3D hydrogel structures, the encapsulation of cells, and in drug delivery systems. The use of photopolymerization processes requires an appropriate initiating system which, in biomedical applications, must meet additional criteria: high water solubility, non-toxicity to cells, and compatibility with visible low-power light sources. This article is a literature review on those compounds that act as photoinitiators of photopolymerization processes in biomedical applications. The division of initiators according to the method of photoinitiation was described and the related mechanisms were discussed. Examples from each group of photoinitiators are presented, and their benefits, limitations and applications are outlined.
  • 1043
  • 10 Jun 2020
Topic Review
Antimicrobial Polymers
Antibiotic resistance has increased markedly in Gram-negative bacteria, causing severe infections intractable with traditional drugs and amplifying mortality and healthcare costs. Consequently, to find novel antimicrobial compounds, active on multidrug resistant bacteria, is mandatory. In this regard, cationic antimicrobial peptides (CAMPs)—able to kill pathogens on contact—could represent an appealing solution. However, low selectivity, hemolytic toxicity and cost of manufacturing, hamper their massive clinical application. In the recent years—starting from CAMPs as template molecules—less toxic and lower-cost synthetic mimics of CAMPs, including cationic peptides, polymers and dendrimers, have been developed. Although the pending issue of hemolytic toxicity and biodegradability is still left not completely solved, cationic antimicrobial polymers (CAPs), compared to small drug molecules, thanks to their high molecular weight, own appreciable selectivity, reduced toxicity toward eukaryotic cells, more long-term activity, stability and non-volatility. With this background, an updated overview concerning the state of the art of the main manufactured types of CAPs, active on Gram-negative bacteria, is herein reported, including synthetic procedure and action’s mechanism. Information about the antibacterial activity, advantages and drawbacks of the most appealing compounds was also provided.
  • 963
  • 12 Jan 2021
Topic Review
Chitosan in Fish Biotechnology
Chitosan is increasingly used for safe drug and nucleic acid delivery due to well-known properties such as bioadhesion, low toxicity, biodegradability and biocompatibility. Furthermore, chitosan derivatization can be easily performed to improve solubility and stability of chitosan-nucleic acid polyplexes, and enhance efficient target cell drug delivery, cell uptake, intracellular endosomal escape, unpacking and nuclear import of expression plasmids. This review focus attention on recent advances in chitosan-mediated gene delivery for fish biotechnology applications such as fish vaccination against bacterial and viral infection, control of gonadal development, and gene overexpression and silencing for overcoming metabolic limitations such as dependence on protein-rich diets and low glucose tolerance of farmed fish.
  • 956
  • 27 Oct 2020
Topic Review
Meat Packaging
The term ‘packaging’ refers to the technological intervention aimed at the protection of food from a variety of factors, which provokes the product detriment. Packaging is considered as one of the most interesting technological aspects and a constantly evolving issue in food production. 
  • 897
  • 21 Jan 2021
Topic Review
Semiconductor Gas Sensors
Semiconductor materials include metal oxides, conducting polymers, carbon nanotubes, and 2D materials. Metal oxides are most often the first choice due to their ease of fabrication, low cost, high sensitivity, and stability. Some of their disadvantages are low selectivity and high operating temperature. Conducting polymers have the advantage of a low operating temperature and can detect many organic vapors. They are flexible but affected by humidity. Carbon nanotubes are chemically and mechanically stable and are sensitive towards NO and NH3, but need dopants or modifications to sense other gases. Graphene, transition metal chalcogenides, boron nitride, transition metal carbides/nitrides, metal organic frameworks, and metal oxide nanosheets as 2D materials represent gas-sensing materials of the future, especially in medical devices, such as breath sensing.
  • 896
  • 10 Dec 2020
Topic Review
Polymer 3D Printing
Polymer 3D printing is an emerging technology with recent research translating towards increased use in diverse industries. The polymer 3D printing process works by depositing a polymer in a directed fashion to form a completed part, generally through layer by layer deposition.  Polymer printing is advantageous because it enables printing low-cost functional parts with diverse properties and capabilities. An important aspect polymer 3D printing is the consideration of materials, processes, and design strategies that all influence a parts performance. Research in materials has led to the development of polymers with advantageous characteristics for mechanics and biocompatibility, with tuning of mechanical properties achieved by altering printing process parameters. Suitable polymer printing processes include extrusion, resin, and powder 3D printing, which enable directed material deposition for the design of advantageous and customized architectures.  Through careful consideration of material, process, and design it is possible to create a 3D printed polymer part of complex geometry that is tuned for a specific application on a per-print basis.
  • 859
  • 23 Jun 2021
Topic Review
Cellulose
Cellulose is the main substance of a plant’s cell walls, helping plants to remain stiff and upright, hence, it can be extracted from plant sources, agriculture waste, animals, and bacterial pellicle. It is composed of polymer chains consisting of unbranched β (1,4) linked D glucopyranosyl units (anhydroglucose unit, AGU).
  • 845
  • 07 Feb 2021
Topic Review
Jojoba Oil
Jojoba is a widely used medicinal plant that is cultivated worldwide. Its seeds and oil have a long history of use in folklore to treat various ailments, such as skin and scalp disorders, superficial wounds, sore throat, obesity, and cancer; for improvement of liver functions, enhancement of immunity, and promotion of hair growth. Extensive studies on Jojoba oil showed a wide range of pharmacological applications, including antioxidant, anti-acne and antipsoriasis, anti-inflammatory, antifungal, antipyretic, analgesic, antimicrobial, and anti-hyperglycemia activities. In addition, Jojoba oil is widely used in the pharmaceutical industry, especially in cosmetics for topical, transdermal, and parenteral preparations. Jojoba oil also holds value in the industry as an anti-rodent, insecticides, lubricant, surfactant, and a source for the production of bioenergy. Jojoba oil is considered among the top-ranked oils due to its wax, which constitutes about 98% (mainly wax esters, few free fatty acids, alcohols, and hydrocarbons). In addition, sterols and vitamins with few triglyceride esters, flavonoids, phenolic and cyanogenic compounds are also present. 
  • 833
  • 03 Jun 2021
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