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Topic Review
Long-Term Memory
Long-term memory (LTM) is the stage of the Atkinson–Shiffrin memory model in which informative knowledge is held indefinitely. It is defined in contrast to short-term and working memory, which persist for only about 18 to 30 seconds. Long-term memory is commonly labelled as explicit memory (declarative), as well as episodic memory, semantic memory, autobiographical memory, and implicit memory (procedural memory).
  • 2.0K
  • 24 Nov 2022
Topic Review
Tree of Life
The tree of life or universal tree of life is a metaphor, model and research tool used to explore the evolution of life and describe the relationships between organisms, both living and extinct, as described in a famous passage in Charles Darwin's On the Origin of Species (1859). {{Blockquote Tree diagrams originated in the medieval era to represent genealogical relationships. Phylogenetic tree diagrams in the evolutionary sense date back to the mid-nineteenth century. The term phylogeny for the evolutionary relationships of species through time was coined by Ernst Haeckel, who went further than Darwin in proposing phylogenic histories of life. In contemporary usage, tree of life refers to the compilation of comprehensive phylogenetic databases rooted at the last universal common ancestor of life on Earth. Two public databases for the tree of life are TimeTree, for phylogeny and divergence times, and the Open Tree of Life, for phylogeny.
  • 2.0K
  • 18 Oct 2022
Topic Review
The Role of Phytoplankton in Carbon Dioxide Fixation
Marine phytoplankton account for more than half of the carbon dioxide fixation of Earth. The export of carbon is highest at the photic zone of the ocean, which is dominated by phytoplankton. The term phytoplankton comes from the Greek words phyto (plants) and plankton (wanderers or drifters). Plankton can also be zooplanktons that feed on phytoplankton and release fecal pellets that are made of dissolved carbon particles.
  • 2.0K
  • 13 Apr 2022
Topic Review
Lactoferrin and Lactobacilli
Vaginal infections are the most prevalent women's health problem. Incompetent diagnosis, inappropriate treatments, and antibiotic resistance are the main causes of the unsatisfactory results of conventional antimicrobic treatment for these infections. Consequently, several researches have been carried out to identify new treatments for these genital diseases. The significant enhancement in our knowledge of vaginal microbiota has permitted to develop new nonpharmacological strategies for the treatment of vaginal infections that seek to restore the balance of vaginal microflora, as opposed to modifying its components. Among these approaches, bioactive compounds, such as probiotics and nutraceutical proteins (like lactoferrin), deserve particular attention. The aim of this review is to examine the role of probiotics (mainly Lactobacillus spp.) and lactoferrin as new strategies for counteracting bacterial and fungal vaginal infections.
  • 2.0K
  • 30 Oct 2020
Topic Review
Impedance Based Cellular Assays
The development of organ on a chip technology utilising human cells, has the advantages of replacing animal experimentation and providing data more applicable to study of human cell biochemistry and disease. However, measurement of metabolites often requires cell lysis permitting only a single end-point measurement. Development of non-destructive methods for monitoring cell cultures in real-time is desirable in helping to inform pathways of disease and define targets for pharmacological intervention. Impedance-based cellular assays, representing one such technique, are designed to monitor cellular impedance, a property of the insulating nature of cell membranes, resulting from changes in cell shape caused by signalling events inside and between cells. This relies on culturing primary cells or cell lines in vitro directly on microelectrodes or using electrodes in culture media and then monitoring changes in impedance over time in response to external treatments compared to untreated controls. Impedance measurements are recorded in real-time at one or several frequencies and can be sampled several times a second for as long as desired. This is beneficial in pinpointing changes with time in culture and can be useful in determining the starting point of a toxic effect or a therapeutic window. A further advantage of impedance-based cellular assays lie in their ability to monitor the cell culture without using specific cell or protein labels, which might otherwise influence the target being studied. Depending on the system used, changes in impedance can be correlated with alterations in basolateral adhesion, membrane integrity, tight junctions and barrier function.
  • 2.0K
  • 30 Oct 2020
Topic Review
Antimicrobial-resistance genes in human gut
Antibiotic-resistance has long been associated with the use and abuse of antibiotics. However, increasing evidence is suggesting that antibiotic-resistance is in fact a phenomenon that has been occurring in natural environments for thousands and possibly millions of years. With the expansion of the microbiome field, it is now possible to characterize antibiotic-resistance genes altogether in different samples, including the human gut. This has also enabled the characterization of ancient human gut microbiomes, which also include antibiotic-resistance genes. Mummified gut remains represent a unique opportunity to characterize the microbiome and antibiotic-resistance genes prior the antibiotic-therapy era. Surprisingly, mummies from the Inca and Italian nobility cultures showed to possess antibiotic-resistance-like genes similar to modern-day antibiotic-resistance genes conferring resistance to beta-lactams, sulfa, quinolones and vancomycin, just to mention a few examples. This is intriguing as it further supports that antibiotic-resistance began in the environment and was transferred to the human gut by means that remain to be investigated and are a matter of ongoing speculation.
  • 2.0K
  • 29 Oct 2020
Topic Review
P-Coumaric Acid in Cosmetics
p-Coumaric acid is a natural metabolite contained in many edible plants, and its antioxidant activities in reducing oxidative stress and inflammatory reactions have been demonstrated in various experimental models. p-Coumaric acid has an optimal structure to be a competitive inhibitor of tyrosinase that catalyzes key reactions in the melanin biosynthetic pathway. Experimental evidence supports this notion as it was found to be a more potent inhibitor of tyrosinase, especially toward human enzymes, than other well-known tyrosinase inhibitors such as arbutin and kojic acid. p-Coumaric acid inhibited melanin synthesis in murine melanoma cells, human epidermal melanocytes, and 3-dimensionally reconstituted human skin models. Ex vivo skin permeation experiments and in vivo efficacy tests for p-coumaric acid confirmed its efficient transdermal delivery and functional efficacy in reducing erythema development and skin pigmentation due to ultraviolet exposure. Human studies further supported its effectiveness in hypopigmentation and depigmentation. These findings suggest that p-coumaric acid has good potential to be used as a skin-lightening active ingredient in cosmetics. 
  • 2.0K
  • 30 Jul 2021
Topic Review
T Lymphocyte
Exosomes are extracellular vesicles (EV) of endosomal origin (multivesicular bodies, MVB) constitutively released by many different eukaryotic cells by fusion of MVB to the plasma membrane. However, inducible exosome secretion controlled by cell surface receptors is restricted to very few cell types and a limited number of cell surface receptors. Among these, exosome secretion is induced in T lymphocytes and B lymphocytes when stimulated at the immune synapse (IS) via T-cell receptor (TCR) and B-cell receptor (BCR), respectively. IS formation by T and B lymphocytes constitutes a crucial event involved in antigen-specific, cellular and humoral immune responses. Upon IS formation by T and B lymphocytes with antigen-presenting cells (APC) the convergence of MVB towards the microtubule organization center (MTOC), and MTOC polarization to the IS, are involved in polarized exosome secretion at the synaptic cleft. This specialized mechanism provides the immune system with a finely-tuned strategy to increase the specificity and efficiency of crucial secretory effector functions of B and T lymphocytes. Since inducible exosome secretion by antigen-receptors is a critical and unique feature of the immune system this entry considers the study of the traffic events leading to polarized exosome secretion at the IS and some of their biological consequences.
  • 2.0K
  • 29 Oct 2020
Topic Review
How Genes Work
Most genes contain the information needed to make functional molecules called proteins. Proteins do most of the work in cells and are required for the structure, function, and regulation of the body's tissues and organs.
  • 2.0K
  • 24 Dec 2020
Topic Review
Carpobrotus edulis
Carpobrotus edulis, formerly known as Mesembryanthemum edule L, belongs to the Aizoaceae family of plants. It is a facultative halophytic invasive medicinal and edible succulent plant that is native to South Africa and is distributed worldwide. Hitherto, this plant appears to be mainly known for its ornamental use in decorations, soil stabilization and erosion control, and not for its many potential medicinal and nutritional benefits, thus suggesting its underutilization. This entry presents cogent and comprehensive information on the distribution, ethnomedicinal use, phytochemistry,pharmacology, toxicology, and nutritional value of Carpobrotus edulis and provides the rationale for further pharmacognostic research that will validate its many folkloric medicinal and nutraceutical claims, and promote its standardization into a commercially available product.
  • 2.0K
  • 21 Oct 2020
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