Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Chikungunya Virus
Arboviruses, in general, are a global threat due to their morbidity and mortality, which results in an important social and economic impact. Chikungunya virus (CHIKV), one of the most relevant arbovirus currently known, is a re-emergent virus that causes a disease named chikungunya fever, characterized by a severe arthralgia (joint pains) that can persist for several months or years in some individuals. Until now, no vaccine or specific antiviral drug is commercially available. Nitrogen heterocyclic scaffolds are found in medications, such as aristeromycin, favipiravir, fluorouracil, 6-azauridine, thioguanine, pyrimethamine, among others. New families of natural and synthetic nitrogen analogous compounds are reported to have significant anti-CHIKV effects. In the present work, we focus on these nitrogen-based heterocyclic compounds as an important class with CHIKV antiviral activity.
  • 732
  • 16 Jan 2021
Topic Review
Chinese Alchemy
Chinese alchemy is an ancient Chinese scientific and technological approach to alchemy, a part of the larger tradition of Taoist body-spirit cultivation developed from the traditional Chinese understanding of medicine and the body. According to original texts such as the Cantong qi, the body is understood as the focus of cosmological processes summarized in the five agents, or wu xing, the observation and cultivation of which leads the practitioner into greater alignment with the operation of the Tao, the great cosmological principle of everything. Therefore, the traditional view in China is that alchemy focuses mainly on the purification of one's spirit and body in the hopes of gaining immortality through the practice of Qigong and/or consumption and use of various concoctions known as alchemical medicines or elixirs, each of which having different purposes. Pao zhi (Pao chi) cites the pharmacological processing (of Chinese materia medica) as used in the practice of Traditional Chinese Medicine, such as honey or wine frying and roasting with toxic metals such as mercury, lead, and arsenic. According to J.C. Cooper's Chinese Alchemy: The Taoist Quest for Immortality, Taoism had two distinct parts, the classical Tao Chia, which was mystical and stemmed primarily from Laozi and Zhuangzi, and the more popular Tao Chiao, which was the popular, magical and alchemical side of Taoism. Cooper states that a common viewpoint is that "classical Taoism [Daoism] was the original but was too austere and rarefied for the general populace ... [but] Tao Chiao fulfilled the day-to-day needs of the people."
  • 2.4K
  • 16 Nov 2022
Topic Review
Chinese Herb-Synthesized Silver Nanoparticles by Phytonanotechnology
Biologically synthesized silver nanoparticles (AgNPs) are potential antimicrobial agents commonly used in clinical treatment, such as wound dressing, topical ointments and anticancer agents. Recently, AgNPs with leaf and root extract ofPanax ginsenghave been successfully synthesized and showed potential antimicrobial activity. Different parts of Chinese herbs, including leaves, stenches, roots, and fruit extract, are widely applied for curing diseases.
  • 777
  • 29 Mar 2022
Topic Review
Chiral Hydroxamic Acid Ligands in Asymmetric Synthesis
Chiral hydroxamic acid (HA) and bis-hydroxamic acid (BHA) ligands have made significant contributions to the field of asymmetric synthesis, particularly in the synthesis of natural products. These ligands possess unique molecular structures that allow for exceptional stereochemical control, leading to their widespread use in catalytic systems.
  • 205
  • 19 Dec 2023
Topic Review
Chiral Monolithic Silica-Based HPLC Columns
Ultrahigh pressure HPLC is based on the use of small sub-2-µm non-porous particle packed columns that can provide large surface area than the classical particle packed stationary phase for more efficient separation thus allowing the use of shorter columns with equivalent resolution to save the analysis time. The accompanied high back pressure of the small particle packed columns is overcoming by running the column in an ultrahigh pressure HPLC instrument that can resist high back pressure of up to 15,000 psi or 10,000 psi for longer column lifetimes. This has been achieved by the introduction of UHPLC system to run the chromatographic process with the sub-2-µm particle packed columns. 
  • 540
  • 31 Aug 2021
Topic Review
Chiral Porous Organic Frameworks
Organocatalysis, the use of chiral organic molecules as catalysts, has emerged as a highly efficient alternative to traditional asymmetric catalysis methods. Chiral porous organic frameworks have emerged as candidates for heterogeneous asymmetric organocatalysis.
  • 241
  • 20 Jul 2023
Topic Review
Chitin
       Chitin, being the second most abundant biopolymer after next to cellulose, has been gaining popularity since its initial first discovery by Braconot in 1811. However, fundamental knowledge and literature on about chitin and its derivatives from insects are difficult to obtain. The most common and sought-after sources of chitin are shellfishes (especially crustaceans) and other aquatic invertebrates. The amount of shellfishes available is obviously restricted by the amount of food waste that is allowed; hence, it is a limited resource. Therefore,Hence, insects are the best choices since, out of 1.3 million species in the world, 900,000 are insects, making them the most abundant species in the world. In this review, a total of 82 samples from shellfishes—crustaceans and mollusks (n = 46), insects (n = 23), and others (n = 13)—have been collected and studied for their chemical extraction of chitin and its derivatives. The aim of this paper is to review the extraction method of chitin and chitosan for a comparison of the optimal demineralization and deproteinization processes with, so as to consideration of insects as alternative sources of chitin. The methods employed in this review are based on comprehensive bibliographic research. Based on previous data, chitin and chitosan yield contents of insects in their study favorably compares and competes with those of commercial chitin and chitosan—for example, 45% in Bombyx eri, 36.6% in Periostracum cicadae (cicada sloughs), and 26.2% in Chyrysomya megacephala. Therefore, according to the data reported by previous researchers, with comparable yield values to those of against crustacean chitin and the great interests of in insects as alternative sources, efforts towards comprehensive knowledge in this field are relevant.
  • 2.4K
  • 30 Oct 2020
Topic Review
Chitin and Chitosan
Chitin and its derivative chitosan are highly abundant polymers in nature, appearing in both the shells and exoskeletons of various marine and non-marine species. Since they possess favorable properties, such as biocompatibility, biodegradability, non-toxicity, and non-immunogenicity, they have gained recent attention due to their enormous potential biomedical applications. The polycationic surface of chitosan enables it to form hydrogenic and ionic bonds with drug molecules, which is one of its most useful properties. Because chitosan is biocompatible, it can therefore be used in drug delivery systems. The development of chitosan-based nanoparticles has also contributed to the significance of chitin as a drug delivery system that can deliver drugs topically. Furthermore, chitin can be used in cancer treatment as a vehicle for delivering cancer drugs to a specific site and has an antiproliferative effect by reducing the viability of cells. Finally, chitosan can be used as a wound dressing in order to promote the faster regeneration of skin epithelial cells and collagen production by fibroblasts.
  • 1.2K
  • 01 Aug 2022
Topic Review
Chitosan Adsorbent
Chitin is mentioned as the second most abundant and important natural biopolymer in worldwide scale. The main sources for the extraction and exploitation of this natural polysaccharide polymer are crabs and shrimps. Chitosan (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) is the most important derivative of chitin and can be used in a wide variety of applications including cosmetics, pharmaceutical and biomedical applications, food, etc., giving this substance high value-added applications. Moreover, chitosan has applications in adsorption because it contains amino and hydroxyl groups in its molecules, and can thus contribute to many possible adsorption interactions between chitosan and pollutants (pharmaceuticals/drugs, metals, phenols, pesticides, etc.). However, it must be noted that one of the most important techniques of decontamination is considered to be adsorption because it is simple, low-cost, and fast. 
  • 1.3K
  • 01 Jun 2021
Topic Review
Chitosan and Chitosan Modified by Functionalization
The biomedical and therapeutic importance of chitosan and chitosan derivatives is the subject of interdisciplinary research. In this entry, researchers intended to consolidate some of the recent discoveries regarding the potential of chitosan and its derivatives to be used for biomedical and other purposes. Why chitosan? Because chitosan is a natural biopolymer that can be obtained from one of the most abundant polysaccharides in nature, which is chitin. Compared to other biopolymers, chitosan presents some advantages, such as accessibility, biocompatibility, biodegradability, and no toxicity, expressing significant antibacterial potential. In addition, through chemical processes, a high number of chitosan derivatives can be obtained with many possibilities for use. 
  • 1.4K
  • 02 Apr 2022
  • Page
  • of
  • 467
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Video Production Service
Feedback