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
Environmental Challenges Facing Martian Colonisation
Mars is a focus of New Space Age exploration and colonisation, but there are significant challenges to successful colonisation by humankind. Environmental microbes play a key role in supporting the ecosystems of Earth, especially within the biodegradation and bioremediation sectors.
  • 2.4K
  • 16 Jan 2024
Topic Review
Bioethanol Production of Distillery Stillage
Distillery stillage has a high energy potential (13.6 MJ/kg TS, 10.4 MJ/kg COD), which indicates that it can be processed via anaerobic digestion and is a suitable substrate for conversion into energy.
  • 2.4K
  • 16 Nov 2021
Topic Review
Fe-Mn-Si-Based Shape Memory Alloys
In civil engineering, beam structures such as bridges require reinforcement to increase load-bearing capacity and extend service life due to damage, aging, and capacity degradation under long-time services and disasters. The utilization of Fe-based shape memory alloys (Fe-SMA) to reinforce structures has been proven efficient and reliable, and the recovery stress of activated Fe-SMA can satisfy the reinforcement requirements.
  • 2.4K
  • 09 Jun 2023
Topic Review
MAYV Pathogenesis and Transmission Mechanisms
Mayaro virus (MAYV), isolated for the first time in Trinidad and Tobago, has captured the attention of public health authorities worldwide following recent outbreaks in the Americas. It has a propensity to be exported outside its original geographical range, because of the vast distribution of its vectors. Moreover, most of the world population is immunologically naïve with respect to infection with MAYV which makes this virus a true threat. The recent invasion of several countries by Aedes albopictus underscores the risk of potential urban transmission of MAYV in both tropical and temperate regions. In humans, the clinical manifestations of MAYV disease range from mild fever, rash, and joint pain to arthralgia. In the absence of a licensed vaccine and clinically proven therapeutics against Mayaro fever, prevention focuses mainly on household mosquito control. However, as demonstrated for other arboviruses, mosquito control is rather inecient for outbreak management and alternative approaches to contain the spread of MAYV are therefore necessary. Despite its strong epidemic potential, little is currently known about MAYV.
  • 2.4K
  • 27 Oct 2020
Topic Review
Hepatic Glucagon Resistance
A key criterion for the most common chronic liver disease—non-alcoholic fatty liver disease (NAFLD)—is an intrahepatic fat content above 5% in individuals who are not using steatogenic agents or having significant alcohol intake. Subjects with NAFLD have increased plasma concentrations of glucagon, and emerging evidence indicates that subjects with NAFLD may show hepatic glucagon resistance. For many years, glucagon has been thought of as the counterregulatory hormone to insulin with a primary function of increasing blood glucose concentrations and protecting against hypoglycemia. However, in recent years, glucagon has re-emerged as an important regulator of other metabolic processes including lipid and amino acid/protein metabolism.
  • 2.4K
  • 06 Jan 2021
Topic Review
Bacillus Species and Heavy Metals
 Heavy metals are one of the major pollutants that contribute to the escalating problem of environmental pollution, being primarily introduced in sensitive ecological habitats through industrial effluents, wastewater, as well as sewage of various industries. Microbial bioremediation, particularly the use of bacteria, has gained attention due to the feasibility and efficiency of using them in removing heavy metals from contaminated environments. Bacteria have several methods of processing heavy metals through general resistance mechanisms, biosorption, adsorption, and efflux mechanisms. Bacillus spp. are model Gram-positive bacteria that have been studied extensively for their biosorption abilities and molecular mechanisms that enable their survival as well as their ability to remove and detoxify heavy metals.
  • 2.4K
  • 09 Aug 2021
Topic Review
Electrolyte Imbalance
Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, fluid balance, oxygen delivery, acid–base balance and much more. Electrolyte imbalances can develop by consuming too little or too much electrolyte as well as excreting too little or too much electrolyte. Examples of electrolytes include: calcium, chloride, magnesium, phosphate, potassium, and sodium. Electrolyte disturbances are involved in many disease processes, and are an important part of patient management in medicine. The causes, severity, treatment, and outcomes of these disturbances can differ greatly depending on the implicated electrolyte. The most serious electrolyte disturbances involve abnormalities in the levels of sodium, potassium or calcium. Other electrolyte imbalances are less common and often occur in conjunction with major electrolyte changes. The kidney is the most important organ in maintaining appropriate fluid and electrolyte balance, but other factors such as hormonal changes and physiological stress play a role.
  • 2.4K
  • 02 Nov 2022
Topic Review
Education for Sustainable Development
Education can serve the purpose of trying to mitigate catastrophes, from the climate change education perspective. Therefore, understanding how teachers are engaging with sustainability issues can help to reveal how they cope with it. In a school context, teachers can have a role in enacting an interconnection between critical thinking (CT) as a potentially useful tool and education for sustainable development (ESD), in terms of educating and communicating the importance of sustainability to future generations.
  • 2.4K
  • 14 Nov 2022
Topic Review
Shear Thickening Mechanism
Shear thickening fluid (STF) is a dense colloidal suspension of nanoparticles in a carrier fluid in which the viscosity increases dramatically with a rise in shear rate. Due to the excellent energy absorption and energy dissipation of STF, there is a desire to employ STFs in a variety of impact applications.
  • 2.4K
  • 05 Jun 2023
Topic Review
Mechanism of Antibiotics Resistance
Bacterial drug resistance is rapidly developing as one of the greatest threats to human health. Bacteria will adopt corresponding strategies to crack the inhibitory effect of antibiotics according to the antibacterial mechanism of antibiotics, involving the mutation of drug target, secreting hydrolase, and discharging antibiotics out of cells through an efflux pump, etc. Bacteria are found to constantly evolve new resistance mechanisms to antibiotics, including target protective protein, changes in cell morphology, and so on, endowing them with multiple defense systems against antibiotics, leading to the emergence of multi-drug resistant (MDR) bacteria and the unavailability of drugs in clinics. 
  • 2.4K
  • 28 Sep 2022
Topic Review
Dream Chronicles
Dream Chronicles, originally titled Dream Chronicles: The Endless Slumber, is an adventure, hidden object, and puzzle casual game developed by KatGames and published by PlayFirst. It is the first installment in the series. Set in a mystical world where mortal and fairy realms collide, the game tells the story of a mortal woman named Faye who is the only being able to awaken from a powerful fairy's dream spell. She embarks on an adventure through a dream world to find her fairy husband and save her hometown. To solve the mystery, players must complete puzzles and search for clues leading to the whereabouts of Faye's husband. As the first part of the first trilogy, Dream Chronicles spawned two direct sequels, Dream Chronicles 2 and Dream Chronicles, which were released in 2008 and 2009 respectively.
  • 2.4K
  • 12 Oct 2022
Topic Review
Forward Osmosis
Forward osmosis (FO), the most common osmotically driven membrane process, stands out as the most promising alternative for RO processes due to its inherently low fouling tendency, easier fouling removal, and energy efficiency when compared to pressure-driven–type membrane processes.
  • 2.4K
  • 21 Jan 2021
Topic Review
Exploring Coastal Access in South Africa
Coastal spaces have been highly contested terrains in South Africa, dating from the colonial period to the present time. Inclusive documentation of the history of coastal access in South Africa is inadequate. The alienation of the African majority from coastal access in South Africa has been systematically executed through various legislations. Although 1994 (democratic era) ushered in a political change, coastal spaces in South Africa still reflect historical racial divide, with former Caucasian areas well-endowed with facilities whilst others are still underdeveloped. The lack of access to coastal resources remains a challenge to many previously disadvantaged communities, owing to South Africa’s history of Apartheid. Apartheid spatial planning remains a factor that undermines equitable access to the coast.
  • 2.4K
  • 07 Apr 2022
Topic Review
Defining Infidelity
The experience of infidelity can be a traumatic affair that ruptures an individual's expectation of their most significant person. Its impact can cause significant emotional, psychological, and cognitive dysfunction for all parties involved. And although its definition is fluid, infidelity can occur in several different ways.
  • 2.4K
  • 10 Mar 2023
Topic Review
Antimicrobial Polymers
Antibiotic resistance has increased markedly in Gram-negative bacteria, causing severe infections intractable with traditional drugs and amplifying mortality and healthcare costs. Consequently, to find novel antimicrobial compounds, active on multidrug resistant bacteria, is mandatory. In this regard, cationic antimicrobial peptides (CAMPs)—able to kill pathogens on contact—could represent an appealing solution. However, low selectivity, hemolytic toxicity and cost of manufacturing, hamper their massive clinical application. In the recent years—starting from CAMPs as template molecules—less toxic and lower-cost synthetic mimics of CAMPs, including cationic peptides, polymers and dendrimers, have been developed. Although the pending issue of hemolytic toxicity and biodegradability is still left not completely solved, cationic antimicrobial polymers (CAPs), compared to small drug molecules, thanks to their high molecular weight, own appreciable selectivity, reduced toxicity toward eukaryotic cells, more long-term activity, stability and non-volatility. With this background, an updated overview concerning the state of the art of the main manufactured types of CAPs, active on Gram-negative bacteria, is herein reported, including synthetic procedure and action’s mechanism. Information about the antibacterial activity, advantages and drawbacks of the most appealing compounds was also provided.
  • 2.4K
  • 12 Jan 2021
Topic Review
BioFilms
Biofilms are aggregates formed as a protective survival state by microorganisms to adapt to the environment and can be resistant to antimicrobial agents and host immune responses due to chemical or physical diffusion barriers, modified nutrient environments, suppression of the growth rate within biofilms, and the genetic adaptation of cells within biofilms. With the widespread use of medical devices, medical device-associated biofilms continue to pose a serious threat to human health, and these biofilms have become the most important source of nosocomial infections. However, traditional antimicrobial agents cannot completely eliminate medical device-associated biofilms. New strategies for the treatment of these biofilms and targeting biofilm infections are urgently required. Several novel approaches have been developed and identified as effective and promising treatments.
  • 2.4K
  • 13 Apr 2021
Topic Review
Phrynosoma
Horned lizards (Phrynosoma), also known as horny toads or horntoads, are a genus of North American lizards and the type genus of the family Phrynosomatidae. The common names refer directly to their horns or to their flattened, rounded bodies, and blunt snouts. The generic name Phrynosoma means "toad-bodied". In common with true toads (amphibians of the family Bufonidae), horned lizards tend to move sluggishly, often remain motionless, and rely on their remarkable camouflage to avoid detection by predators. They are adapted to arid or semiarid areas. The spines on the lizard's back and sides are modified reptile scales, which prevent water loss through the skin, whereas the horns on the head are true horns (i.e., they have a bony core). Of the 22 species of horned lizards, 15 are native to the United States. The largest-bodied and most widely distributed of the US species is the Texas horned lizard.
  • 2.4K
  • 26 Oct 2022
Topic Review
Determining Number of Clusters in a Data Set
For a certain class of clustering algorithms (in particular k-means, k-medoids and expectation–maximization algorithm), there is a parameter commonly referred to as k that specifies the number of clusters to detect. Other algorithms such as DBSCAN and OPTICS algorithm do not require the specification of this parameter; hierarchical clustering avoids the problem altogether. The correct choice of k is often ambiguous, with interpretations depending on the shape and scale of the distribution of points in a data set and the desired clustering resolution of the user. In addition, increasing k without penalty will always reduce the amount of error in the resulting clustering, to the extreme case of zero error if each data point is considered its own cluster (i.e., when k equals the number of data points, n). Intuitively then, the optimal choice of k will strike a balance between maximum compression of the data using a single cluster, and maximum accuracy by assigning each data point to its own cluster. If an appropriate value of k is not apparent from prior knowledge of the properties of the data set, it must be chosen somehow. There are several categories of methods for making this decision.
  • 2.4K
  • 22 Nov 2022
Topic Review
Derealization
Derealization is an alteration in the perception of the external world, causing sufferers to perceive it as unreal, distant, distorted or falsified. Other symptoms include feeling as if one's environment is lacking in spontaneity, emotional coloring, and depth. It is a dissociative symptom that may appear in moments of severe stress. Derealization is a subjective experience pertaining to a person's perception of the outside world, while depersonalization is a related symptom characterized by dissociation towards one's own body and mental processes. The two are commonly experienced in conjunction with one another, but are also known to occur independently. Chronic derealization is fairly rare, and may be caused by occipital–temporal dysfunction. Experiencing derealization for long periods of time or having recurring episodes can be indicative of many psychological disorders, and can cause significant distress among sufferers. However, temporary derealization symptoms are commonly experienced by the general population a few times throughout their lives, with a lifetime prevalence of up to 26-74% and a prevalence of 31–66% at the time of a traumatic event.
  • 2.4K
  • 29 Nov 2022
Topic Review
Modification of Clay Minerals for Carbon Capture
Carbon capture is among the most sustainable strategies to limit carbon dioxide emissions, which account for a large share of human impact on climate change and ecosystem destruction. This growing threat calls for novel solutions to reduce emissions on an industrial level. Carbon capture by amorphous solids is among the most reasonable options as it requires less energy when compared to other techniques and has comparatively lower development and maintenance costs. In this respect, the method of carbon dioxide adsorption by solids can be used in the long-term and on an industrial scale. Furthermore, certain sorbents are reusable, which makes their use for carbon capture economically justified and acquisition of natural resources full and sustainable. Clay minerals, which are a universally available and versatile material, are amidst such sorbents. These materials are capable of interlayer and surface adsorption of carbon dioxide. In addition, their modification allows to improve carbon dioxide adsorption capabilities even more. 
  • 2.4K
  • 13 Apr 2022
  • Page
  • of
  • 2799
Featured Entry Collections
>>

Featured Reprints

>>
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Medieval Royal Iconography
Academic Video Service
Feedback