Your browser does not fully support modern features. Please upgrade for a smoother experience.
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 by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Prophylaxis and Treatment Against Kp
Klebsiella pneumoniae (Kp) is an opportunistic pathogen and the leading cause of healthcare-associated infections, mostly affecting subjects with compromised immune systems or suffering from concurrent bacterial infections. However, the dramatic increase in hypervirulent strains and the emergence of new multidrug-resistant clones resulted in Kp occurrence among previously healthy people and in increased morbidity and mortality, including neonatal sepsis and death across low- and middle-income countries. As a consequence, carbapenem-resistant and extended spectrum β-lactamase-producing Kp have been prioritized as a critical anti-microbial resistance threat by the World Health Organization and this has renewed the interest of the scientific community in developing a vaccine as well as treatments alternative to the now ineffective antibiotics. Capsule polysaccharide is the most important virulence factor of Kp and plays major roles in the pathogenesis but its high variability (more than 100 different types have been reported) makes the identification of a universal treatment or prevention strategy very challenging. However, less variable virulence factors such as the O-Antigen, outer membrane proteins as fimbriae and siderophores might also be key players in the fight against Kp infections.
  • 1.1K
  • 10 May 2021
Topic Review
Insulin in Health and Disease
Insulin is a polypeptide hormone mainly secreted by β cells in the islets of Langerhans of the pancreas. The hormone potentially coordinates with glucagon to modulate blood glucose levels; insulin acts via an anabolic pathway, while glucagon performs catabolic functions. Insulin regulates glucose levels in the bloodstream and induces glucose storage in the liver, muscles, and adipose tissue, resulting in overall weight gain. The modulation of a wide range of physiological processes by insulin makes its synthesis and levels critical in the onset and progression of several chronic diseases. Although clinical and basic research has made significant progress in understanding the role of insulin in several pathophysiological processes, many aspects of these functions have yet to be elucidated. This review provides an update on insulin secretion and regulation, and its physiological roles and functions in different organs and cells, and implications to overall health. We cast light on recent advances in insulin-signaling targeted therapies, the protective effects of insulin signaling activators against disease, and recommendations and directions for future research.
  • 1.1K
  • 30 Jun 2021
Topic Review
Sphingolipids in Central Nervous System
Bioactive lipids are a newly defined class of lipids that are actively involved in the regulation of a variety of cellular events. As the name indicates, these molecular factors are subjected to action at the arrival of a specific stimulus and undergo subsequent transitions to cope up with the insult. Among these bioactive lipids, sphingolipids have emerged as distinctive mediators of various cellular processes, ranging from cell growth and proliferation to cellular apoptosis, executing immune responses to regulating inflammation. Recent studies have made it clear that sphingolipids, their metabolic intermediates (ceramide, sphingosine-1-phosphate, and N-acetyl sphingosine), and enzyme systems (cyclooxygenases, sphingosine kinases, and sphingomyelinase) harbor diverse yet interconnected signaling pathways in the central nervous system (CNS), orchestrate CNS physiological processes, and participate in a plethora of neuroinflammatory and neurodegenerative disorders.
  • 1.1K
  • 05 Aug 2021
Topic Review
Oxi-Inflamm-Aging Related Cardiorenal Syndrome
Kidney failure is also a major cause of cardiovascular morbidity and mortality. Indeed, epidemiological studies have demonstrated that chronic kidney disease (CKD) is a significant risk for cardiovascular events independently of classical risk. 
  • 1.1K
  • 06 Jan 2022
Topic Review
DNA Methyltransferases
DNA methylation is an epigenetic mark that living beings have used in different environments. The MTases family catalyzes DNA methylation. This process is conserved from archaea to eukaryotes, from fertilization to every stage of development, and from the early stages of cancer to metastasis. The family of DNMTs has been classified into DNMT1, DNMT2, and DNMT3. Each DNMT has been duplicated or deleted, having consequences on DNMT structure and cellular function, resulting in a conserved evolutionary reaction of DNA methylation. DNMTs are conserved in the five kingdoms of life: bacteria, protists, fungi, plants, and animals. 
  • 1.1K
  • 30 Aug 2022
Topic Review
γ-aminobutyric Acid and Barley Seedlings
It has been revealed that high NaCl stress (>60 mmol L−1) induced phenolics accumulation in barley seedlings, with γ-aminobutyric acid (GABA) playing a key role. Interestingly, low NaCl stimulus (20 mmol L−1) enhancing phenolics synthesis and growth of barley seedlings was also reported recently. Hence, exogenous GABA and its bio-synthesis inhibitor 3-mercaptopropionic acid (3-MP) were applied to reveal the mechanism of GABA regulating phenolics metabolism in barley seedlings treated with 20 mmol L−1 NaCl. The contents of total phenolics and flavonoids significantly increased by 11.64% and 14.52% under NaCl, respectively. The addition of GABA further increased phenolics and flavonoids contents, especially for gallic acid, protocatechuic acid, caffeic acid, and quercetin, compared with NaCl treatment. Simultaneously, GABA increased the activities and mRNA levels of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), and 4-coumalyl CoA ligase (4CL). The addition of 3-MP suppressed the above effects, except for increasing the protein levels of PAL, C4H, and 4CL. Low concentration of NaCl not only promoted growth, but also stimulated endogenous GABA metabolism to affect key enzymes activities and mRNA levels for phenolics synthesis in barley seedlings.
  • 1.1K
  • 15 Oct 2021
Topic Review
Biochemical and Physiological Application of Pterin Photochemistry
Pterins are low-molecular weight heterocyclic compounds widely distributed in living organisms, primarily as reduced coenzymes. Structurally, pterins are a conjugated system of pyrazine and pyrimidine rings, the so-called pteridine, which is accompanied by a carbonyl group (C=O) at the C4 position and an amino group (NH2) at the C2 position. The pteridine structure is also characteristic of folates (folic acid and its derivatives) and flavins, or benzopteridines, which are derivatives of isoalloxazine. Folates are usually called “conjugated pterins” since they possess a para-aminobenzoilglutamine residue, whereas pterins are called “unconjugated pterins”. In addition to pterin, folates include a para-aminobenzoic acid (p-ABA) residue and one to five glutamic acid (Glu) residues.
  • 1.1K
  • 13 Dec 2022
Topic Review
The Fibroblast Growth Factor Receptors
Breast cancer (BC) is the most frequent form of malignancy and second only to lung cancer as cause of deaths in women. Notwithstanding many progresses made in the field, metastatic BC has a very poor prognosis. As therapies are becoming more personalized to meet the needs of patients, a better knowledge of the molecular biology leading to the disease unfolds the possibility to project more precise compounds or antibodies targeting definite alteration at the molecular level and functioning on such cancer-causing molecules expressed in cancer cells of patients, or present as antigens on the surface of cancer cell membranes. Fibroblast growth factor receptor (FGFR) is one of such druggable targets, activated by its own ligands -namely the Fibroblast Growth Factors (FGFs). This pathway provides a vast range of interesting molecular targets pursued at different levels of clinical investigation.
  • 1.1K
  • 01 Nov 2020
Topic Review
Polyphenols and its Natural Preservatives
The use of synthetic/artificial preservatives has become common and has not been widely accepted by consumers as they are aware of the fact that exposure to preservatives can lead to adverse effects on health, which is a major area of concern for researchers. Naturally occurring phenolic compounds appear to be extensively used as bio-preservatives to prolong the shelf life of the finished product. 
  • 1.1K
  • 07 Oct 2023
Topic Review
Ischemic Stroke and Excitotoxicity
Stroke is a relevant cause of death, disability and dementia worldwide. In ischemic stroke, excitotoxicity is the main mechanism of neuronal death in the penumbra area, a potentially recoverable tissue surrounding the irreversibly damaged infarct core. In excitatory neurons, scaffold protein PSD-95 plays a central role in neuronal function but also survival/death choices. Thus, this protein is a promising target for development of neuroprotective strategies for stroke and other pathologies similarly associated to excitotoxicity.
  • 1.1K
  • 13 Dec 2021
Topic Review
The Structure and Function of ABCA1
The adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) was identified by Luciani et al. over 36 years ago by PCR cloning and found to be located on chromosome 9q22-31. ABCA1 belongs to what was then a growing family of transmembrane proteins sharing many structural and functional similarities. ABCA1 was initially thought to be involved in the phagocytosis of apoptotic cells and to play a role in the regulation of the inflammatory response. Recent studies of structure-function relationships have shown that ABCA1 transports cholesterol and phospholipids across the plasma membrane to generate high-density lipoproteins (HDLs).
  • 1.1K
  • 28 Feb 2023
Topic Review
The Protein Corona
The prolific applicability of nanomaterials has made them a common citizen in biological systems, where they interact with proteins forming a biological corona complex. 
  • 1.1K
  • 14 Apr 2023
Topic Review
Marine Resources for the Omicron SARS-CoV-2 Variant
In November of 2021, a recently evolved variant of SARS-CoV-2, omicron, was discovered. In just one month, omicron has spread to more than 89 countries resulting in a rapid rise in cases and a new wave of infections. With over 46 mutations, omicron brings concern to the public health and may be able to infect at a greater capacity than previous strains. Although able to infect double vaccinated and previously infected individuals, the booster vaccine may prove promising. However, more research is needed to fully elucidate the key function of each mutation and to better develop effective drugs. Marine resources may be a promising drug discovery avenue to investigate. Through viral entry blockade and preventing viral replication and protein synthesis, metabolites produced from marine organisms may be promising against the evolving SARS-CoV-2.
  • 1.1K
  • 29 Jun 2022
Topic Review
Evaluation of Biological Activity of Natural Compounds
Natural compounds have diverse structures and are present in different forms of life. Metabolites such as tannins, anthocyanins, and alkaloids, among others, serve as a defense mechanism in live organisms and are undoubtedly compounds of interest for the food, cosmetic, and pharmaceutical industries.
  • 1.1K
  • 01 Aug 2022
Topic Review
Transcriptomic Harmonization
Emergence of methods interrogating gene expression at high throughput gave birth to quantitative transcriptomics, but also posed a question of inter-comparison of expression profiles obtained using different equipment and protocols and/or in different series of experiments. Addressing this issue is challenging, because all of the above variables can dramatically influence gene expression signals and, therefore, cause a plethora of peculiar features in the transcriptomic profiles. Millions of transcriptomic profiles were obtained and deposited in public databases of which the usefulness is however strongly limited due to the inter-comparison issues. Platform/protocol/batch bias can be efficiently reduced not only for the comparisons of limited transcriptomic datasets. Instead, instruments were proposed for transforming gene expression profiles into the universal, uniformly shaped format that can support multiple inter-comparisons for reasonable calculation costs. This forms a basement for universal indexing of all or most of all types of RNA sequencing and microarray hybridization profiles.
  • 1.1K
  • 02 Dec 2022
Topic Review
Biological Effects of Fluorescein Photochemistry
Fluorescein is a fluorescent organic dye used as tracer, contrasting agent or a diagnostic tool in various fields of medicine and natural sciences in general.
  • 1.1K
  • 26 May 2022
Topic Review
The Role of microRNAs in Neurological Pathologies
MicroRNAs (miRNAs) are small non-coding RNA molecules that are 18–25 nucleotides long (22 nucleotides on average) and involved in the transcriptional and post-transcriptional regulation of gene expression by RNA interference, which is of great interest to molecular biologists, geneticists, and biochemists. These molecules are mainly present intracellularly, but there is also an extracellular (circulating) microRNA fraction. The existence and functions of more than 2500 human miRNAs are known. 
  • 1.1K
  • 29 Aug 2023
Topic Review
Posttranscriptional Defects of Selenoenzymes
Methylmercury (MeHg) is a well-known neurotoxicant that causes severe intoxication in humans. Research progress has pointed out the importance of oxidative stress in the pathogenesis of MeHg toxicity. MeHg-induced intracellular relative selenium deficiency due to the greater affinity of MeHg for selenohydryl groups and selenides leads to failure in the recoding of a UGA codon for selenocysteine and results in the degradation of antioxidant selenoenzyme mRNA by nonsense-mediated mRNA decay. The defect of antioxidant selenoenzyme replenishment exacerbates MeHg-mediated oxidative stress. 
  • 1.1K
  • 09 Nov 2020
Topic Review
Chemical Changes in Atherosclerosis
Fiberoptic Raman spectroscopy and Raman microscopy were used to investigate alterations in the aorta wall and the surrounding perivascular adipose tissue (PVAT) in the murine model of atherosclerosis (Apoe-/-/Ldlr-/- mice). Both abdominal and thoracic parts of the aorta were studied to account for the heterogenic chemical composition of aorta and its localization-dependent response in progression of atherosclerosis. The average Raman spectra obtained for both parts of aorta cross sections revealed that the chemical composition of intima-media layers along aorta remains relatively homogeneous while the lipid content in the adventitia layer markedly increases with decreasing distance to PVAT. Moreover, our results demonstrate that the increase of the lipid to protein ratio in the aorta wall correlates directly with the increased unsaturation level of lipids in PVAT and these changes occur only in the abdominal, but not in thoracic, aorta. In summary, distinct pathophysiological response in the aortic vascular wall could be uncovered by fiber optic Raman spectroscopy based on simple parameters detecting chemical contents of lipids in PVAT.
  • 1.1K
  • 21 Jul 2020
Topic Review
Oxidative Stress in Pulmonary Hypertension
Pulmonary hypertension (PH) is a progressive disease characterized by elevated artery pressures and pulmonary vascular resistance. Underlying mechanisms comprise endothelial dysfunction, pulmonary artery remodeling and vasoconstriction. Several studies have shown evidence of the critical role of oxidative stress in PH pathophysiology. Alteration of redox homeostasis produces excessive generation of reactive oxygen species, inducing oxidative stress and the subsequent alteration of biological molecules. Exacerbations in oxidative stress production can lead to alterations in nitric oxide signaling pathways, contributing to the proliferation of pulmonary arterial endothelial cells and smooth muscle cells, inducing PH development. 
  • 1.1K
  • 12 May 2023
  • Page
  • of
  • 133
Featured Entry Collections
>>

Featured Books

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