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Topic Review
Life
Life is the characteristic state of organisms. Properties common to terrestrial organisms (plants, animals, fungi, protists and bacteria) are that they are cellular, carbon-and-water-based with complex organization, having a metabolism, a capacity to grow, respond to stimuli, reproduce and—through natural selection—adapt. An entity with the above properties is considered to be organic life. However, not every definition of life considers all of these properties to be essential. For example, the capacity for descent with modification is often taken as the only essential property of life. This definition notably includes viruses, which do not qualify under narrower definitions as they are acellular and do not metabolise. Broader definitions of life may also include theoretical non-carbon-based life and other alternative biology. The entire Earth contains about 75 billion tons of biomass (life), which lives within various environments within the biosphere.
  • 1.1K
  • 26 Oct 2022
Topic Review
Alternative Splicing
Alternative splicing (AS) is a critical post-transcriptional regulatory mechanism used by more than 95% of transcribed human genes and responsible for structural transcript variation and proteome diversity.
  • 1.1K
  • 18 Mar 2021
Topic Review
Cell Membrane Theory of Senescence
Lipids are an essential constituent of the cell membrane of which polyunsaturated fatty acids (PUFAs) are the most important component. Activation of phospholipase A2 (PLA2) induces the release of PUFAs from the cell membrane that form precursors to both pro- and ant-inflammatory bioactive lipids that participate in several cellular processes. PUFAs GLA (gamma-linolenic acid), DGLA (dihomo-GLA), AA (arachidonic acid), EPA (eicosapentaenoic acid) and DHA (do-cosahexaenoic acid) are derived from dietary linoleic acid (LA) and alpha-linolenic acid (ALA) by the action of desaturases whose activity declines with age. Consequently, aged cells are deficient in GLA, DGLA, AA, AA, EPA and DHA and their metabolites. LA, ALA, AA, EPA and DHA can also be obtained direct from diet and their deficiency (fatty acids) may indicate malnutrition and deficiency of several minerals, trace elements and vitamins some of which are also much needed co-factors for the normal activity of desaturases. In many instances (patients) the plasma and tissue levels of GLA, DGLA, AA, EPA and DHA are low (as seen in patients with hyperten-sion, type 2 diabetes mellitus) but they do not have deficiency of other nutrients. Hence, it is reasonable to consider that the deficiency of GLA, DGLA, AA, EPA and DHA noted in these condi-tions are due to the decreased activity of desaturases and elongases. PUFAs stimulate SIRT1 through protein kinase A-dependent activation of SIRT1-PGC1α complex and thus, increase rates of fatty acid oxidation and prevent lipid dysregulation associated with aging. 
  • 1.1K
  • 19 Mar 2021
Topic Review
DNA Dyes
Cell quantification is widely used both in basic and applied research. A typical example of its use is drug discovery research. Presently, plenty of methods for cell quantification are available. In this review, the basic techniques used for cell quantification, with a special emphasis on techniques based on fluorescent DNA dyes, are described. 
  • 1.1K
  • 23 Sep 2021
Topic Review
Flashbulb Memory
A flashbulb memory is a highly detailed, exceptionally vivid "snapshot" of the moment and circumstances in which a piece of surprising and consequential (or emotionally arousing) news was learned about. The term "flashbulb memory" suggests the surprise, indiscriminate illumination, detail, and brevity of a photograph; however flashbulb memories are only somewhat indiscriminate and are far from complete. Evidence has shown that although people are highly confident in their memories, the details of the memories can be forgotten. Flashbulb memories are one type of autobiographical memory. Some researchers believe that there is reason to distinguish flashbulb memories from other types of autobiographical memory because they rely on elements of personal importance, consequentiality, emotion, and surprise. Others believe that ordinary memories can also be accurate and long-lasting if they are highly distinctive, personally significant, or repeatedly rehearsed. Flashbulb memories have six characteristic features: place, ongoing activity, informant, own affect, other affect, and aftermath. Arguably, the principal determinants of a flashbulb memory are a high level of surprise, a high level of consequentiality, and perhaps emotional arousal.
  • 1.1K
  • 17 Nov 2022
Topic Review
Cerberin
Cerberin is a type of cardiac glycoside, a steroidal class found in the seeds of the dicotyledonous angiosperm genus Cerbera; including the suicide tree (Cerbera odollam) and the sea mango (Cerbera manghas). This class includes digitalis-like agents, channel-blockers that as a group have found historic uses as cardiac treatments, but which at higher doses are extremely toxic; in the case of cerberin, consumption of the C. odollam results in poisoning with presenting nausea, vomiting, and abdominal pain, often leading to death. The natural product has been structurally characterized, its toxicity is clear—it is often used as an intentional human poison in third-world countries, and accidental poisonings with fatalities have resulted from individuals even indirectly consuming the agent—but its potentially therapeutic pharmacologic properties are very poorly described.
  • 1.1K
  • 10 Nov 2022
Topic Review
47,XYY Syndrome
47,XYY syndrome is characterized by an extra copy of the Y chromosome in each of a male's cells. Although many males with this condition are taller than average, the chromosomal change sometimes causes no unusual physical features. Most males with 47,XYY syndrome have normal production of the male sex hormone testosterone and normal sexual development, and they are usually able to father children.  
  • 1.1K
  • 23 Dec 2020
Topic Review
Consolidated Bioprocessing
The long road from emerging biotechnologies to commercial “green” biosynthetic routes for chemical production relies in part on efficient microbial use of sustainable and renewable waste biomass feedstocks. One solution is to apply the consolidated bioprocessing approach, whereby microorganisms convert lignocellulose waste into advanced fuels and other chemicals. As lignocellulose is a highly complex network of polymers, enzymatic degradation or “saccharification” requires a range of cellulolytic enzymes acting synergistically to release the abundant sugars contained within. Complications arise from the need for extracellular localisation of cellulolytic enzymes, whether they be free or cell-associated.
  • 1.1K
  • 01 Jun 2021
Topic Review
Metal Oxide Nanoparticles for Food Packaging
Metal oxide nanoparticles have a higher surface area due to their smaller size, which makes them useful in various applications such as biosensors, bio-nanotechnology, and nanomedicine. These nanoparticles have many atoms on their surfaces, making them highly reactive.  There is a huge demand for packaging materials that can keep food fresher for extended periods of time. The incorporation of nanoscale fillers in the polymer matrix would assists in the alleviation of packaging material challenges while also improving functional qualities.
  • 1.1K
  • 20 Jun 2022
Topic Review
Nuclear Receptor Related-1 Protein
The entry summarizes the roles of Nurr1 in a wide range of tumors and the underlying pathways for carcinogenesis.  Nuclear receptor related-1 protein (Nurr1), coded by an early response gene, is involved in multiple cellular and physiological functions, including proliferation, survival, and self-renewal. Dysregulation of Nurr1 has been frequently observed in many cancers and is attributed to multiple transcriptional and post-transcriptional mechanisms.
  • 1.1K
  • 26 Nov 2020
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