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Topic Review
Chitosan-Nanoparticles for Oral Insulin Delivery
Diabetes mellitus is a chronic endocrine disease, affecting more than 400 million people around the world. Patients with poorly controlled blood glucose levels are liable to suffer from life-threatening complications, such as cardiovascular, neuropathy, retinopathy and even premature death. Today, subcutaneous parenteral is still the most common route for insulin therapy. Oral insulin administration is favourable and convenient to the patients. In contrast to injection route, oral insulin delivery mimics the physiological pathway of endogenous insulin secretion. However, oral insulin has poor bioavailability (less than 2%) due to the harsh physiological environment through the gastrointestinal tract (GIT). Over the last few decades, many attempts have been made to achieve an effective oral insulin formulation with high bioavailability using insulin encapsulation into nanoparticles as advanced technology. Various natural polymers have been employed to fabricate nanoparticles as a delivery vehicle for insulin oral administration. Chitosan, a natural polymer, is extensively studied due to the attractive properties, such as biodegradability, biocompatibility, bioactivity, nontoxicity and polycationic nature. Numerous studies were conducted to evaluate chitosan and chitosan derivatives-based nanoparticles capabilities for oral insulin delivery. This review highlights strategies that have been applied in the recent five years to fabricate chitosan/chitosan derivatives-based nanoparticles for oral insulin delivery. A summary of the barriers hurdle insulin absorption rendering its low bioavailability such as physical, chemical and enzymatic barriers are highlighted with an emphasis on the most common methods of chitosan nanoparticles preparation. Nanocarriers are able to improve the absorption of insulin through GIT, deliver insulin to the blood circulation and lower blood glucose levels. In spite of some drawbacks encountered in this technology, chitosan and chitosan derivatives-based nanoparticles are greatly promising entities for oral insulin delivery.
  • 2.6K
  • 02 Nov 2020
Topic Review
Lonone
The term ionone is derived from “iona” (Greek for violet) which refers to the violet scent and “ketone” due to its structure. Ionones can either be chemically synthesized or endogenously produced via asymmetric cleavage of β-carotene by β-carotene oxygenase 2 (BCO2). 
  • 2.6K
  • 05 Jan 2021
Topic Review
Sex-Reversed Females of Salmonid Fish
Sex-reversed females (SRFs; masculinised females, neomales) are genetically females; however, owing to masculinisation, they are capable of producing spermatozoa.
  • 2.6K
  • 12 May 2021
Topic Review
Theranostic Radiopharmaceuticals
Theranostic Radiopharmaceuticals (Radiotheranostics) is a term in the medical field to define the combination of therapeutic and diagnostic techniques by a suitable radiopharmaceutical agent. Radionuclides are isotopes that emit radiation or have excess nuclear energy, making them chemically unstable and tend to change into another atom. Various types of radiation can be emitted by radionuclides e.g. alpha particles, beta particles, and gamma energy. In radiotheranostics, a pharmaceutical agent (drug) is needed to be a carrier molecule that introduces the radionuclide to its target. Radionuclides are then used as a source of radiation in radiotheranostics that are responsible for diagnosing or treating various diseases.
  • 2.6K
  • 24 May 2022
Topic Review
Nanotechnological Approaches for Removal of Persistent Organic Pollutants
Persistent organic pollutants (POPs) are a group of hazardous chemical compounds that originate from anthropogenic activities during production, utilization, and disposal. They can impact living beings and the environment adversely because of their ease of transportation by wind and water. The level of hazardous persistent organic pollutants is increasing every day in the environment.
  • 2.6K
  • 02 Aug 2022
Topic Review
AI Mk. VIII Radar
Radar, Airborne Interception, Mark VIII, or AI Mk. VIII for short, was the first operational microwave-frequency air-to-air radar. It was used by Royal Air Force night fighters from late 1941 until the end of World War II. The basic concept, using a moving parabolic antenna to search for targets and track them accurately, remained in use by most airborne radars well into the 1980s. Low-level development began in 1939 but was greatly sped after the introduction of the cavity magnetron in early 1940. This operated at 9.1 cm wavelength (3 GHz), much shorter than the 1.5 m wavelength of the earlier AI Mk. IV. Shorter wavelengths allowed it to use smaller and much more directional antennas. Mk. IV was blinded by the reflections off the ground from its wide broadcast pattern, which made it impossible to see targets flying at low altitudes. Mk. VIII could avoid this by keeping the antenna pointed upward, allowing it to see any aircraft at or above the horizon. The design was just beginning to mature in late 1941 when the Luftwaffe began low-level attacks. A prototype version, the Mk. VII, entered service on the Bristol Beaufighter in November 1941. A small number of these were sent to units across the UK to provide coverage at low altitudes while Mk. IV equipped aircraft operated at higher altitudes. After a small run of the improved Mk. VIIIA, the definitive Mk. VIII arrived in early 1942, offering higher power as well as a host of electronic and packaging upgrades. It arrived just as production rates of the De Havilland Mosquito began to improve, quickly displacing the Beaufighter units in RAF squadrons. Mk. VIII equipped Mosquitoes would be the premier night fighter from 1943 through the rest of the war. The Mk. VIII spawned a number of variants, notably the AI Mk. IX which included a lock-on feature to ease interceptions. A series of events, including a deadly friendly fire incident, so greatly delayed the Mk. IX that it never entered service. During the late-war period, many UK aircraft adopted the US SCR-720 under the name AI Mk. X. This worked on the same general principles as the Mk. VIII, but used a different display system that offered several advantages. Development of the basic system continued, and the Mk. IX would eventually briefly re-appear in greatly advanced form as the AI.17 during the 1950s.
  • 2.6K
  • 16 Nov 2022
Topic Review
GMC CCKW 2½-ton 6X6 Truck
The GMC CCKW, also known as "Jimmy", or the G-508 by its Ordnance Supply Catalog nr, was a highly successful series of off-road capable, 2​1⁄2-ton, 6x6 trucks, built in large numbers to a standardized design (from 1941 to 1945) for the U.S. Army, that saw heavy service, predominantly as cargo trucks, in both World War II and the Korean War. The original "Deuce and a Half", it formed the backbone of the famed Red Ball Express that kept Allied armies supplied as they pushed eastward after the Normandy invasion. The CCKW came in many variants, including open or closed cab, long wheelbase (LWB) CCKW-353 and short (SWB) CCKW-352, and over a score of specialized models, but the bulk were standard, general purpose, cargo models. A large minority were built with a front mounted winch, and one in four of the cabs had a machine-gun mounting ring above the co-driver's position. Of the almost 2.4 million trucks that the U.S. Army bought between 1939 and December 1945, across all payload weight classes, some 812,000, or just over one third, were ​2 1⁄2-ton trucks. GMC's total production of the CCKW and its variants, including the 2​1⁄2-ton, 6x6, amphibian DUKW, and the 6x4, 5-ton (on-road) CCW-353, amounted to some 572,500 units – almost a quarter of the total WW II U.S. truck production, and 70 percent of the total ​2 1⁄2-ton trucks. GMC's total of ~550,000 purely 6x6 models, including the DUKW, formed the overwhelming majority of the ~675,000 six by six ​2 1⁄2-ton trucks, and came in less than 100,000 shy of the almost 650,000 World War II jeeps. Additionally, GM built over 150,000 units of the CCKW's smaller brother, the ​1 1⁄2-ton, 4x4 Chevrolet G506, at the same factory. The GMC CCKW began to be phased out, once the M35 series trucks were first deployed in the 1950s, but remained in active U.S. service until the mid-1960s. Eventually, the M35 series, originally developed by REO Motors, succeeded the CCKW as the U.S. Army's standard ​2 1⁄2-ton, 6x6 cargo truck.
  • 2.6K
  • 22 Nov 2022
Topic Review
Culture
Culture is the collective expression of a community's identity and represents the sum of its members' shared experiences. It encompasses both tangible and intangible elements, ranging from material artifacts and technology to language, rituals, and social norms. As a pervasive force, culture influences individual behaviors, shapes societal structures, and contributes to the diversity of human societies.
  • 2.6K
  • 25 Jan 2024
Topic Review
Emotion Recognition in Virtual Reality
Emotions play a critical role in our daily lives, so the understanding and recognition of emotional responses is crucial for human research. Affective computing research has mostly used non-immersive two-dimensional (2D) images or videos to elicit emotional states. However, immersive virtual reality, which allows researchers to simulate environments in controlled laboratory conditions with high levels of sense of presence and interactivity, is becoming more popular in emotion research. Moreover, its synergy with implicit measurements and machine-learning techniques has the potential to impact transversely in many research areas, opening new opportunities for the scientific community. This paper presents a systematic review of the emotion recognition research undertaken with physiological and behavioural measures using head-mounted displays as elicitation devices. The results highlight the evolution of the field, give a clear perspective using aggregated analysis, reveal the current open issues and provide guidelines for future research.
  • 2.6K
  • 29 Jan 2021
Topic Review
Cryotropic Gelation and Macroporous Scaffolds
Cryogels obtained by the cryotropic gelation process are macroporous hydrogels with a well-developed system of interconnected pores and shape memory. Biodegradable cryogels have been prepared from natural polymers (biopolymers) and synthetic polymers with biodegradable/bioresponsive bonds containing bio-resembling or artificial units. The cryogels could be composed of one type of polymer or a combination of different materials. Polymers from natural origins (plants or animals) attract considerable attention for their intrinsic biocompatibility and potential ability to mimic ECM, favoring cell-matrix interactions for tissue-engineering and regeneration.
  • 2.6K
  • 12 Jul 2021
Topic Review
Nucleoside Analogs
As the non-naturally occurring biomolecules, modified DNA/RNA nucleoside and oligonucleotide analogues composed of L-(deoxy)riboses, have been designed and applied as innovative therapeutics with superior plasma stability, weakened cytotoxicity, and inexistent immunogenicity.
  • 2.6K
  • 29 Dec 2021
Topic Review
Structure and Physicochemical Properties of Konjac Glucomannan
Konjac glucomannan (KGM), can not only be applied as a food additive, which greatly improves the taste and flavor of food and extends the shelf life of food but also occupies an important role in T2DM (Type 2 Diabetes Mellitus). KGM can extend gastric emptying time, increase satiety, and promote liver glycogen synthesis, and also has the potential to improve intestinal flora and the metabolic system through a variety of molecular pathways in order to positively regulate oxidative stress and immune inflammation, and protect the liver and kidneys.
  • 2.6K
  • 01 Feb 2023
Topic Review
Carbon-Isotope Signature of Diagenetic Carbonates
Diagenetic carbonates often show large variations in their carbon isotope compositions. Variations are mainly the result of isotope fractionation effects during microbial metabolic processes, and these processes themselves may induce carbonate formation. Inorganic carbon from dissimilatory microbial activity shows negative carbon isotope values (d13C), in particular if methane is used as a carbon source. In turn, inorganic carbon produced during methanogenesis shows positive d13C values. The range of isotope values preserved in the carbonate phase ultimately depends on the reservoir sizes, diffusive mixing of different carbon sources, and episodic formation of carbonate. The carbon-isotope signature of diagenetic carbonates therefore represents an archive of past biogeochemical activity in the subsurface.
  • 2.6K
  • 30 Oct 2020
Topic Review
Articular Cartilage Injury and Repair
Articular cartilage injury and repair is an issue of growing importance. Although common, defects of articular cartilage present a unique clinical challenge due to its poor self-healing capacity, which is largely due to its avascular nature. There is a critical need to better study and understand cellular healing mechanisms to achieve more effective therapies for cartilage regeneration. This article aims to describe the key features of cartilage which is being modelled using tissue engineered cartilage constructs and ex vivo systems. These models have been used to investigate chondrogenic differentiation and to study the mechanisms of cartilage integration into the surrounding tissue.
  • 2.6K
  • 19 Jan 2021
Topic Review
Andrographolide
Traditionally, Andrographis paniculata has been used as an herbal remedy for lung infection treatments. Its leaves contain a diterpenoid labdane called andrographolide responsible for a wide range of biological activities such as antioxidant, anti-inflammatory, and anti-cancer properties. This entry is a brief review of the antioxidant mechanisms and the regulation of the Nrf2 (nuclear factor (erythroid-derived 2)-like 2) signaling pathway by andrographolide.
  • 2.6K
  • 30 Jul 2021
Topic Review
Conceptualization of the Migration Phenomenon
The migration process has become particularly important for Romania in the last 20 years, and its socio-economic, political and cultural effects affect the Romanian state. That is why flexible policies are needed in order to be coherent, to have as main purpose keeping specialists in the country in certain basic economic fields, as well to implement measures to determine the return of specialists and students who have left to study abroad.
  • 2.6K
  • 14 Apr 2022
Topic Review
Modesto Manifesto
The Modesto Manifesto, was a set of standards for religious leaders that became notable as the signature practice among men in which they avoid spending time alone with people of the opposite sex to whom they are not married. It has additionally taken a more modern meaning as a display of integrity, a means of avoiding sexual temptation, to avoid any appearance of doing something considered morally objectionable, and to avoid being accused of sexual harassment or assault. Created for male evangelical Protestant leaders by Billy Graham, it has been popularly known as the "Billy Graham rule." Its adoption by U.S. Vice President Mike Pence has had it additionally nicknamed the "Mike Pence rule". The Modesto Manifesto has found a prominent foothold on Wall Street and more generally in American finance for its ability to limit the "risk" of perceived sexual impropriety.
  • 2.6K
  • 14 Oct 2022
Topic Review Video Peer Reviewed
Multi-Criteria Decision Making (MCDM) Methods and Concepts
Multi-criteria decision-making (MCDM) is one of the main decision-making problems which aims to determine the best alternative by considering more than one criterion in the selection process. MCDM has manifold tools and methods that can be applied in different fields from finance to engineering design. This entry aims to provide a survey on the MCDM concept, its applications, main categories, and different methods. The final section provides manifold information and statistics on the published works in the MCDM fields. Some of the main methods are also listed in this section.
  • 2.6K
  • 10 Jan 2023
Topic Review
P-Glycoprotein
P-glycoprotein (P-gp) is a crucial membrane transporter situated on the cell’s apical surface, being responsible for eliminating xenobiotics and endobiotics. P-gp modulators are compounds that can directly or indirectly affect this protein, leading to changes in its expression and function. These modulators can act as inhibitors, inducers, or activators, potentially causing drug–drug interactions (DDIs). 
  • 2.6K
  • 15 Nov 2023
Topic Review
Green Seaweeds and Ulvan
This entry analyzed the recent trend towards, progresses towards the preparation of chemicals of, and value-added biomaterials from marine macroalgae resources, especially green seaweeds and their derived ulvan polysaccharides for various applications. In recent years, ulvan both in pristine and modified forms has gained a large amount of attention for its effective utilization in various areas due to its unique physiochemical properties, lack of exploration, and higher green seaweed production. The pristine form of ulvan (sulfated polysaccharides) is used as a bio-component; food ingredient; or a raw material for the production of numerous chemicals such as fuels, cosmetics, and pharmaceuticals, whereas its modified form is used in the sector of composites, membranes, and scaffolds, among others, because of its physicochemical properties.
  • 2.6K
  • 15 Jun 2021
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