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Topic Review
Crocodile
Crocodiles (family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans (family Alligatoridae), the gharial and false gharial (family Gavialidae) among other extinct taxa. Although they appear similar, crocodiles, alligators and the gharial belong to separate biological families. The gharial, with its narrow snout, is easier to distinguish, while morphological differences are more difficult to spot in crocodiles and alligators. The most obvious external differences are visible in the head, with crocodiles having narrower and longer heads, with a more V-shaped than a U-shaped snout compared to alligators and caimans. Another obvious trait is that the upper and lower jaws of the crocodiles are the same width, and the teeth in the lower jaw fall along the edge or outside the upper jaw when the mouth is closed; therefore, all teeth are visible, unlike an alligator, which possesses in the upper jaw small depressions into which the lower teeth fit. Also, when the crocodile's mouth is closed, the large fourth tooth in the lower jaw fits into a constriction in the upper jaw. For hard-to-distinguish specimens, the protruding tooth is the most reliable feature to define the species' family. Crocodiles have more webbing on the toes of the hind feet and can better tolerate saltwater due to specialized salt glands for filtering out salt, which are present, but non-functioning, in alligators. Another trait that separates crocodiles from other crocodilians is their much higher levels of aggression. Crocodile size, morphology, behaviour and ecology differ somewhat among species. However, they have many similarities in these areas as well. All crocodiles are semiaquatic and tend to congregate in freshwater habitats such as rivers, lakes, wetlands and sometimes in brackish water and saltwater. They are carnivorous animals, feeding mostly on vertebrates such as fish, reptiles, birds and mammals, and sometimes on invertebrates such as molluscs and crustaceans, depending on species and age. All crocodiles are tropical species that, unlike alligators, are very sensitive to cold. They separated from other crocodilians during the Eocene epoch, about 55 million years ago. Many species are at the risk of extinction, some being classified as critically endangered.
  • 1.8K
  • 21 Oct 2024
Topic Review
Prosopis Plant
Members of the Prosopis genus are native to America, Africa and Asia, and have long been used in traditional medicine. The Prosopis species most commonly used for medicinal purposes are P. africana, P. alba, P. cineraria, P. farcta, P. glandulosa, P. juliflora, P. nigra, P. ruscifolia and P. spicigera, which are highly effective in asthma, birth/postpartum pains, callouses, conjunctivitis, diabetes, diarrhea, expectorant, fever, flu, lactation, liver infection, malaria, otitis, pains, pediculosis, rheumatism, scabies, skin inflammations, spasm, stomach ache, bladder and pancreas stone removal. Flour, syrup, and beverages from Prosopis pods have also been potentially used for foods and food supplement formulation in many regions of the world. In addition, various in vitro and in vivo studies have revealed interesting antiplasmodial, antipyretic, anti-inflammatory, antimicrobial, anticancer, antidiabetic and wound healing effects. The phytochemical composition of Prosopis plants, namely their content of C-glycosyl flavones (such as schaftoside, isoschaftoside, vicenin II, vitexin and isovitexin) has been increasingly correlated with the observed biological effects. 
  • 1.8K
  • 22 Jul 2021
Topic Review
Sperm in Honey Bee Drones
The quality of honey bee drone semen is relevant in different contexts, ranging from colony productivity to pathology, toxicology and biodiversity preservation. Despite its importance, considerably less knowledge is available on this subject for the honey bee when compared to other domestic animal species. A proper assessment of sperm quality requires a multiple testing approach which discriminates between the different aspects of sperm integrity and functionality. Most studies on drone semen quality have only assessed a few parameters, such as sperm volume, sperm concentration and/or sperm plasma membrane integrity.
  • 1.8K
  • 13 Jul 2021
Topic Review
Apigenin
Inflammation is intimately linked to the development or worsening of several non-infectious diseases. Chronic conditions such as cancer and cardiovascular disorders often result from tissue injury and genomic changes induced by persistent low-grade inflammation. Current treatments for these diseases are often not curative and come with significant side effects. Apigenin, a flavonoid found in common fruits and vegetables, has garnered attention for its broad biological activities, including anti-inflammatory, antioxidant, and anti-cancer properties. Despite its potential, achieving therapeutic levels of apigenin, especially in the CNS, remains challenging due to its limited bioavailability and rapid metabolism. Recent research has focused on developing advanced delivery systems, such as nanosized drug delivery systems, enteric polymer-coated spheres, and intranasal formulations, to enhance its bioavailability and therapeutic efficacy. These innovative delivery methods show promise in maximizing apigenin's potential as a therapeutic agent for chronic inflammatory diseases, metabolic syndrome, cardiovascular diseases, cancer, and neuroinflammatory disorders.
  • 1.8K
  • 05 Aug 2024
Topic Review
Awns
Awns are extending structures from lemmas in grasses and are very active in photosynthesis, contributing directly to the filling of the developing grain. Barley (Hordeum vulgare L.) awns are highly diverse in shape and length and are known to be controlled by multiple awn-related genes. The genetic effects of these genes on awn diversity and development in barley are multiplexed and include complementary effect, cumulative effect, duplicate effect, recessive epistasis, dominant epistasis, and inhibiting effect, each giving a unique modified Mendelian ratio of segregation. The complexity of gene interactions contributes to the awn diversity in barley. Excessive gene interactions create a challenging task for genetic mapping and specific strategies have to be developed for mapping genes with specific interactive effects. Awn gene interactions can occur at different levels of gene expression, from the transcription factor-mediated gene transcription to the regulation of enzymes and metabolic pathways. A better understanding of gene interactions will greatly facilitate deciphering the genetic mechanisms underlying barley awn diversity and development. 
  • 1.8K
  • 07 May 2021
Topic Review
Baddeley's Model of Working Memory
Baddeley's model of working memory is a model of human memory proposed by Alan Baddeley and Graham Hitch in 1974, in an attempt to present a more accurate model of primary memory (often referred to as short-term memory). Working memory splits primary memory into multiple components, rather than considering it to be a single, unified construct. Baddeley & Hitch proposed their three-part working memory model as an alternative to the short-term store in Atkinson & Shiffrin's 'multi-store' memory model (1968). This model is later expanded upon by Baddeley and other co-workers to add a fourth component, and has become the dominant view in the field of working memory. However, alternative models are developing, providing a different perspective on the working memory system. The original model of Baddeley & Hitch was composed of three main components: the central executive which acts as a supervisory system and controls the flow of information from and to its slave systems: the phonological loop and the visuo-spatial sketchpad. The phonological loop stores verbal content, whereas the visuo-spatial sketchpad caters to visuo-spatial data. Both the slave systems only function as short-term storage centers. In 2000, Baddeley added a third slave system to his model, the episodic buffer. Baddeley & Hitch's argument for the distinction of two domain-specific slave systems in the older model was derived from experimental findings with dual-task paradigms. Performance of two simultaneous tasks requiring the use of two separate perceptual domains (i.e. a visual and a verbal task) is nearly as efficient as performance of the tasks individually. In contrast, when a person tries to carry out two tasks simultaneously that use the same perceptual domain, performance is less efficient than when performing the tasks individually. A fourth component of Baddeley's model was added 25 years later to complement the central executive system. The third slave system was designated as episodic buffer. It is considered a limited-capacity system that provides temporary storage of information by conjoining information from the subsidiary systems, and long-term memory, into a single episodic representation.
  • 1.7K
  • 04 Nov 2022
Topic Review
Podophyllotoxin
Podophyllotoxin is an aryltetralin-type lignan isolated from species of Podophyllum. Two most common sources are the rhizomes of Podophyllum peltatum (American mayapple) and Sinopodophyllum hexandrum Royle (Barberry family). The podophyllotoxin extract has been documented for its use as a laxative, and as a remedy for various medical complications such as gonorrhea, tuberculosis, menstrual disorders, psoriasis, dropsy, cough, syphilis and venereal warts.
  • 1.7K
  • 27 Apr 2021
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.
  • 1.7K
  • 15 Jun 2021
Topic Review
Tissue
In biology, tissue is a biological organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. The English word "tissue" derives from the French word "tissu", the past participle of the verb tisser, "to weave". The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is studied in both plant anatomy and physiology. The classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. Developments in electron microscopy, immunofluorescence, and the use of frozen tissue-sections have enhanced the detail that can be observed in tissues. With these tools, the classical appearances of tissues can be examined in health and disease, enabling considerable refinement of medical diagnosis and prognosis.
  • 1.7K
  • 26 Oct 2022
Topic Review
Mycosporine-Like Amino Acids as Sunscreen
Prolonged exposure to harmful ultraviolet radiation (UVR) can induce many chronic or acute skin disorders in humans. To protect themselves, many people have started to apply cosmetic products containing UV-screening chemicals alone or together with physical sunblocks, mainly based on titanium–dioxide (TiO2) or zinc-oxide (ZnO2). However, it has now been shown that the use of chemical and physical sunblocks is not safe for long-term application, so searches for the novel, natural UV-screening compounds derived from plants or bacteria are gaining attention. Certain photosynthetic organisms such as algae and cyanobacteria have evolved to cope with exposure to UVR by producing mycosporine-like amino acids (MAAs). These are promising substitutes for chemical sunscreens containing commercially available sunblock filters. The use of biopolymers such as chitosan for joining MAAs together or with MAA-Np (nanoparticles) conjugates will provide stability to MAAs similar to the mixing of chemical and physical sunscreens. 
  • 1.7K
  • 21 May 2021
Topic Review
FTIR Spectroscopy as Diagnostic Tools
Infrared spectroscopy has long been used to characterize chemical compounds, but the applicability of this technique to the analysis of biological materials containing highly complex chemical components is arguable. However, recent advances in the development of infrared spectroscopy have significantly enhanced the capacity of this technique in analyzing various types of biological specimens. Consequently, there is an increased number of studies investigating the application of infrared spectroscopy in screening and diagnosis of various diseases. The lack of highly sensitive and specific methods for early detection of cancer has warranted the search for novel approaches. Being more simple, rapid, accurate, inexpensive, non-destructive and suitable for automation compared to existing screening, diagnosis, management and monitoring methods, Fourier transform infrared spectroscopy can potentially improve clinical decision-making and patient outcomes by detecting biochemical changes in cancer patients at the molecular level. Besides the commonly analyzed blood and tissue samples, extracellular vesicle-based method has been gaining popularity as a non-invasive approach. Therefore, infrared spectroscopic analysis of extracellular vesicles could be a useful technique in the future for biomedical applications.
  • 1.7K
  • 23 Jun 2021
Topic Review
Thaumarchaeota
The Thaumarchaeota or Thaumarchaea (from the Ancient Greek:) are a phylum of the Archaea proposed in 2008 after the genome of Cenarchaeum symbiosum was sequenced and found to differ significantly from other members of the hyperthermophilic phylum Crenarchaeota. Three described species in addition to C. symbiosum are Nitrosopumilus maritimus, Nitrososphaera viennensis, and Nitrososphaera gargensis. The phylum was proposed in 2008 based on phylogenetic data, such as the sequences of these organisms' ribosomal RNA genes, and the presence of a form of type I topoisomerase that was previously thought to be unique to the eukaryotes. This assignment was confirmed by further analysis published in 2010 that examined the genomes of the ammonia-oxidizing archaea Nitrosopumilus maritimus and Nitrososphaera gargensis, concluding that these species form a distinct lineage that includes Cenarchaeum symbiosum. The lipid crenarchaeol has been found only in Thaumarchaea, making it a potential biomarker for the phylum. Most organisms of this lineage thus far identified are chemolithoautotrophic ammonia-oxidizers and may play important roles in biogeochemical cycles, such as the nitrogen cycle and the carbon cycle. Metagenomic sequencing indicates that they constitute ~1% of the sea surface metagenome across many sites. Thaumarchaeota-derived GDGT lipids from marine sediments can be used to reconstruct past temperatures via the TEX86 paleotemperature proxy, as these lipids vary in structure according to temperature. Because most Thaumarchaea seem to be autotrophs that fix CO2, their GDGTs can act as a record for past Carbon-13 ratios in the dissolved inorganic carbon pool, and thus have the potential to be used for reconstructions of the carbon cycle in the past.
  • 1.7K
  • 20 Oct 2022
Topic Review
Nuclear Receptor Superfamily
The nuclear receptor superfamily comprises a large group of proteins with functions essential for cell signaling, survival, and proliferation. There are multiple distinctions between nuclear superfamily classes defined by hallmark differences in function, ligand binding, tissue specificity, and DNA binding. In this review, we utilize the initial classification system, which defines subfamilies based on structure and functional difference. The defining feature of the nuclear receptor superfamily is that these proteins function as transcription factors. The loss of transcriptional regulation or gain of functioning of these receptors is a hallmark in numerous diseases. For example, in prostate cancer, the androgen receptor is a primary target for current prostate cancer therapies. Targeted cancer therapies for nuclear hormone receptors have been more feasible to develop than others due to the ligand availability and cell permeability of hormones. 
  • 1.6K
  • 12 Aug 2021
Topic Review
Endocannabinoid System (ECS)
The endocannabinoid system (ECS) is an essential signaling system in mammal physiology regulating several biological and disease conditions. ECS’s three main components are (i) cannabinoids receptors (CBR) CBR-1 and CBR-2; (ii) signaling molecules that are lipid-based termed the “endocannabinoids” (EC), endogenous ligands of the CBRs; and (iii) enzymes responsible for synthesizing and degrading ECs. ECS regulates multiple physiological processes, such as brain plasticity and neuronal development, cell death, inflammation, sleep, appetite, pain, and anxiety.
  • 1.6K
  • 24 Mar 2022
Topic Review
Spawn
Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, to spawn refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquatic mammals and reptiles, reproduce through the process of spawning. Spawn consists of the reproductive cells (gametes) of many aquatic animals, some of which will become fertilized and produce offspring. The process of spawning typically involves females releasing ova (unfertilized eggs) into the water, often in large quantities, while males simultaneously or sequentially release spermatozoa (milt) to fertilize the eggs. Most fish reproduce by spawning, as do most other aquatic animals, including crustaceans such as crabs and shrimps, molluscs such as oysters and squid, echinoderms such as sea urchins and sea cucumbers, amphibians such as frogs and newts, aquatic insects such as mayflies and mosquitoes and corals, which are actually small aquatic animals—not plants. Fungi, such as mushrooms, are also said to "spawn" a white, fibrous matter that forms the matrix from which they grow. There are many variations in the way spawning occurs, depending on sexual differences in anatomy, how the sexes relate to each other, where and how the spawn is released and whether or how the spawn is subsequently guarded.
  • 1.6K
  • 08 Nov 2022
Topic Review
Architecture and Composition of the Intestinal Flora
Intestinal microorganisms are composed of bacteria, archaea, eukaryotes, and viruses, and more than 99% of them are bacteria. Approximately 1014 bacteria are known to constitute the intestinal flora in the adult gut, and this number is 10 times the number of human somatic cells.
  • 1.6K
  • 05 Aug 2022
Topic Review
Chemistry and Biosynthesis of Apigenin
Apigenin, a natural bioactive flavonoid widely present in medicinal plants, functional foods, vegetables and fruits, exerts protective effects in models of neurological disorders and cardiovascular diseases and most of these effects are attributed to its antioxidant action.
  • 1.6K
  • 05 Nov 2021
Topic Review
Advanced Glycation End Products (AGEs)
The Maillard reaction is a simple but ubiquitous reaction that occurs both in vivo and ex vivo during the cooking or processing of foods under high-temperature conditions, such as baking, frying, or grilling. Glycation of proteins is a post-translational modification that forms temporary adducts, which, on further crosslinking and rearrangement, form permanent residues known as advanced glycation end products (AGEs). Cooking at high temperature results in various food products having high levels of AGEs. This review underlines the basis of AGE formation and their corresponding deleterious effects on the body. Glycated Maillard products have a direct association with the pathophysiology of some metabolic diseases, such as diabetes mellitus type 2 (DM2), acute renal failure (ARF), Alzheimer’s disease, dental health, allergies, and polycystic ovary syndrome (PCOS). The most glycated and structurally abundant protein is collagen, which acts as a marker for diabetes and aging, where decreased levels indicate reduced skin elasticity. In diabetes, high levels of AGEs are associated with carotid thickening, ischemic heart disease, uremic cardiomyopathy, and kidney failure. AGEs also mimic hormones or regulate/modify their receptor mechanisms at the DNA level. In women, a high AGE diet directly correlates with high levels of androgens, anti-Müllerian hormone, insulin, and androstenedione, promoting ovarian dysfunction and/or infertility. Vitamin D3 is well-associated with the pathogenesis of PCOS and modulates steroidogenesis. It also exhibits a protective mechanism against the harmful effects of AGEs.
  • 1.6K
  • 28 Jul 2021
Topic Review
Marine Organism-Derived Polydeoxyribonucleotide
Polydeoxyribonucleotides (PDRNs) are a family of DNA-derived drugs with a molecular weight ranging from 50 to 1500 kDa, which are mainly extracted from the sperm cells of salmon trout or chum salmon. Many pre-clinical and clinical studies have demonstrated the wound healing and anti-inflammatory properties of PDRN, which are mediated by the activation of adenosine A2A receptor and salvage pathways, in addition to promoting osteoblast activity, collagen synthesis, and angiogenesis. In fact, PDRN is already marketed due to its therapeutic properties against various wound healing- and inflammation-related diseases. 
  • 1.6K
  • 26 May 2021
Topic Review
Major Pathological Hallmarks of Multiple Sclerosis
Multiple Sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system which is characterized by demyelinating lesions and axonal damage. MS is a complex disease characterized by important pathophysiological heterogeneity affecting the clinical appearance, progression and therapeutic response for each patient. Therefore, there is a strong unmet need to define specific biomarkers that will reflect the different features of the disease. Experimental autoimmune encephalomyelitis (EAE) is the most commonly used experimental model for the study of MS, as it resembles the pathological features of human MS in many aspects and has allowed for the elucidation of pathogenesis pathways and the validation of certain targets for MS therapies. 
  • 1.6K
  • 18 Oct 2022
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