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
Calcium Transport Systems in Mitochondria
Calcium (Ca2+) is a divalent cation and a universal second messenger that regulates the most important functions and facets of all eukaryotic cells, including: gene expression, proliferation, regulation of bioenergetics, contraction of muscles, mediation of fertilization, and many other cellular functions. Regulation of free intracellular concentration of Ca2+ is an important mechanism for intracellular signaling, and it is a key component in the mediation of many cell functions and biochemical reactions, being crucial for signal transduction in cells. On top of all that, intra-mitochondrial Ca2+ regulates a cascade of physiological and pathophysiological processes in cells The normal level of intra-mitochondrial Са2+ is essential for the correct functioning of mitochondria; whereas Ca2+ overload is typical for a wide range of mitochondrial dysfunctions and pathophysiological processes. Homeostasis of Ca2+ in the mitochondria is determined by the delicate balance of mitochondrial Ca2+ transport systems in both the inner (IMM) and outer mitochondrial membrane (OMM). Ca2+ influx and efflux systems are composed of different components, including: channels, pumps, antiporters, or Ca2+ binding proteins that cooperate to maintain intra-mitochondrial Ca2+ homeostasis.
  • 1.8K
  • 18 Nov 2020
Topic Review
Coffee and Yeasts
Coffee is one of the most consumed beverages in the world, and its popularity has prompted the necessity to constantly increase the variety and improve the characteristics of coffee as a general commodity. The popularity of coffee as a staple drink has also brought undesired side effects, coffee production, processing and consumption are all accompanied by impressive quantities of coffee-related wastes which can be a threat to the environment. In this review, we integrated the main studies on fermentative yeasts used in coffee-related industries with an emphasis on two different directions: (1) the role of yeast strains in the postharvest processing of coffee, the possibilities to use them as starting cultures for controlled fermentation and their impact on the sensorial quality of processed coffee, and (2) the potential to use yeasts to capitalize on coffee wastes - especially spent coffee grounds—in the form of eco-friendly biomass, biofuel or fine chemical production.
  • 1.8K
  • 07 Feb 2021
Topic Review
Molecular and Functional Properties of Acid-Sensing Ion Channels
Acid-sensing ion channels (ASICs) are voltage-independent H+-gated cation channels largely expressed in the nervous system of rodents and humans, and involved in pain sensing and associated pathologies. At least six isoforms (ASIC1a, 1b, 2a, 2b, 3 and 4) associate into homotrimers or heterotrimers to form functional channels with highly pH-dependent gating properties.
  • 1.8K
  • 25 Oct 2022
Topic Review
Practical Methods for Liver Biology
Molecular and cellular research modalities for the study of liver pathologies have been tremendously improved over the recent decades. Advanced technologies offer novel opportunities to establish cell isolation techniques with excellent purity, paving the path for 2D and 3D microscopy and high-throughput assays (e.g., bulk or single-cell RNA sequencing). The use of stem cell and organoid research will help to decipher the pathophysiology of liver diseases and the interaction between various parenchymal and non-parenchymal liver cells. Furthermore, sophisticated animal models of liver disease allow for the in vivo assessment of fibrogenesis, portal hypertension and hepatocellular carcinoma (HCC) and for the preclinical testing of therapeutic strategies.
  • 1.8K
  • 01 Nov 2020
Topic Review
History of Intersex Surgery
The history of intersex surgery is intertwined with the development of the specialities of pediatric surgery, pediatric urology, and pediatric endocrinology, with our increasingly refined understanding of sexual differentiation, with the development of political advocacy groups united by a human qualified analysis, and in the last decade by doubts as to efficacy, and controversy over when and even whether some procedures should be performed. Prior to the medicalization of intersex, Canon and common law referred to a person's sex as male, female or hermaphrodite, with legal rights as male or female depending on the characteristics that appeared most dominant. The foundation of common law, the Institutes of the Lawes of England described how a hermaphrodite could inherit "either as male or female, according to that kind of sexe which doth prevaile." Single cases have been described by legal cases sporadically over the centuries. Modern ideas of medicalization of intersex and birth defects can be traced to French anatomist Isidore Geoffroy Saint-Hilaire (1805–1861), who pioneered the field of teratology. Since the 1920s surgeons have attempted to "fix" an increasing variety of conditions. Success has often been partial and surgery is often associated with minor or major, transient or permanent complications. Techniques in all fields of surgery are frequently revised in a quest for higher success rates and lower complication rates. Some surgeons, well aware of the immediate limitations and risks of surgery, feel that significant rates of imperfect outcomes are no scandal (especially for the more severe and disabling conditions). Instead they see these negative outcomes as a challenge to be overcome by improving the techniques. Genital reconstruction evolved within this tradition. In recent decades, nearly every aspect of this perspective has been called into question, with increasing concern regarding the human rights implications of medical interventions.
  • 1.8K
  • 01 Nov 2022
Topic Review
α-Lactalbumin
α-Lactalbumin (α-LA) is a small (Mr 14,200), acidic (pI 4-5), Ca2+-binding protein. α-LA is a regulatory component of lactose synthase enzyme system. α-LA is very important in infant nutrition since it constitutes a large part of the whey and total protein in human milk. The protein possesses a single strong Ca2+-binding site, which can also bind Mg2+, Mn2+, Na+, K+, and some other metal cations. It contains several distinct Zn2+-binding sites. Physical properties of α-LA strongly depend on the occupation of its metal binding sites by metal ions. In the absence of bound metal ions α-LA is in the molten globule-like state. The binding of metal ions, and especially of Ca2+, increases stability of α-LA against action of heat, various denaturing agents, and proteases, while the binding of Zn2+ to the Ca2+-loaded protein decreases its stability and causes its aggregation. The thermal unfolding of apo-α-LA takes place in the temperature region from 10 to 30 °C. The binding of Ca2+ under the conditions of low ionic strength shifts the thermal transition to higher temperatures by more than 40 °C. The binding of Mg2+, Na+, and K+ increases protein stability as well. The stronger an ion binds to the protein, the more pronounced the thermal transition shift. All four classes of surfactants (anionic, cationic, non-ionic, and zwitterionic) denature α-LA and the denaturation involves at least one intermediate. The position of any denaturation transition in α-LA (half-transition temperature, half-transition pressure, half-transition denaturant concentration) depends upon metal ion concentration in solution (especially if this metal ion is Ca2+). Therefore, values of denaturation temperature or urea or guanidine hydrochloride denaturing concentration are relatively meaningless for α-LA without specifying the metal ion content(s) and their solution concentration(s). At a neutral or slightly acidic pH at a physiological temperature, α-LA can associate with membranes. The conformations of the membrane-bound protein range from native-like to molten globule-like states. At a low pH, α-LA penetrates the interior of the negatively charged membranes and exhibits a molten globule conformation. Depending on external conditions, α-LA can form amyloid fibrils, amorphous aggregates, nanoparticles, and nanotubes. At pH 2, α-LA in the classical molten globule conformation can form amyloid fibrils. Some of these aggregated states of α-LA (nanoparticles, nanotubes) can be used in practical applications such as drug delivery to tissues and organs. The structure and self-assembly behavior of α-LA are governed by a subtle balance between hydrophobic and polar interactions and this balance can be finely tuned through the addition of selected substances. Small size nanoparticles of α-LA (100 to 200 nm) can be obtained with the use of various desolvating agents. Partially hydrolyzed α-LA can form nanotubes. α-LA and some of its fragments possess bactericidal and antiviral activities. Complexes of partially unfolded α-LA with oleic acid showed significant cytotoxicity to various tumor and bacterial cells. α-LA in such complexes plays a role of a delivery carrier of cytotoxic fatty acid molecules into tumor cells across the cell membrane. Cytotoxic protein–oleic acid complexes possess a common core-shell structure, where an oily core is made of a micellar oleic acid, whereas a proteinaceous shell, which stabilizes the oleic acid micelle, is formed from the flexible, partially unfolded proteins. These complexes called liprotides (lipids and partially denatured proteins), which are potential novel anti-tumorous drugs, can be considered as molten globular containers filled with the toxic oil.
  • 1.8K
  • 31 Aug 2020
Topic Review
Crop Management with the IoT
IoT is becoming a bearing technology for next generation crop management. Cheap networked devices can sense crop fields at a finer grain to give timeliness warnings on the presence of stress conditions and diseases, while on-board devices will monitor field and machine status. Cloud computing allows integrating collected information in a new  generation of FMIS to make decisions and automate field practices by actuators and robot fleets.
  • 1.8K
  • 02 Feb 2021
Topic Review
Src Non-Receptor Tyrosine Kinase
Src non-receptor tyrosine kinase phosphorylates a variety of protein substrates that perform specific cellular functions. Activity of Src is regulated by a variety of stimuli and the Src protein is subjected to several types of post-translational modifications including lipidation, phosphorylation, acetylation, ubiquitylation, sumoylation and oxidation. In particular, p-Tyr416 Src has been known to be an active form while p-Tyr527 Src is an inactive form through autoinhibition by binding to Src SH2 own domain.
  • 1.8K
  • 23 May 2022
Topic Review
Equine Piroplasmosis
Equine piroplasmosis (EP), caused by the hemoparasites Theileria equi, Theileria haneyi, and Babesia caballi, is an important tick-borne disease of equines that is prevalent in most parts of the world. Infection may affect animal welfare and has economic impacts related to limitations in horse transport between endemic and non-endemic regions, reduced performance of sport horses and treatment costs.
  • 1.8K
  • 26 Nov 2020
Topic Review
Amino Acid Transporters
The conventional function of amino acid transporters in mammalian cells is in the maintenance of amino acid homeostasis. Every cell has a need for amino acids from extracellular sources, particularly for the essential amino acids that mammalian cells are not able to synthesize. This need cannot be met without the participation of specific transporters in the plasma membrane because of the hydrophilic nature of these amino acids, a feature that prevents their simple diffusion across the hydrophobic lipid bilayer. 
  • 1.8K
  • 02 Mar 2022
  • Page
  • of
  • 1746
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