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Topic Review
Quantum Dot-Based Lateral Flow Immunoassay
Point-of-care testing (POCT) technology has exhibited an outstanding capability for the detection of several disease biomarkers owing to the fact that such techniques are fast, easy to perform, efficient, and low cost. The lateral flow immunoassay (LFIA) is one such strategy for POCT. LFIA is a well-established platform and a potent assay for fast and inexpensive testing, as this technology is instrumentation independent and allows the visualisation of test results by the naked eye. In order to enhance the sensitivity and specificity of the LFIAs, as well as to allow the quantitation of results, fluorescence immunochromatographic assays have been developed by utilising fluorescent reporters. Fluorescence immunochromatographic assays have advantages over conventional approaches in regard to sensitivity as it produces a higher intensity band on the test and control lines. One such promising fluorescent reporter is quantum dots (QDs). QDs are tiny semiconducting nanocrystals with diameters ranging from 2 to 10 nanometers. QDs have unique electronic characteristics that are intermediate between those of bulk semiconductors and discrete molecules, which is due in part to their high surface-to-volume ratios. The most visible result is fluorescence, in which the nanocrystals emit distinct colours determined by particle size.
  • 3.1K
  • 19 Sep 2022
Topic Review
T Lymphocyte
Exosomes are extracellular vesicles (EV) of endosomal origin (multivesicular bodies, MVB) constitutively released by many different eukaryotic cells by fusion of MVB to the plasma membrane. However, inducible exosome secretion controlled by cell surface receptors is restricted to very few cell types and a limited number of cell surface receptors. Among these, exosome secretion is induced in T lymphocytes and B lymphocytes when stimulated at the immune synapse (IS) via T-cell receptor (TCR) and B-cell receptor (BCR), respectively. IS formation by T and B lymphocytes constitutes a crucial event involved in antigen-specific, cellular and humoral immune responses. Upon IS formation by T and B lymphocytes with antigen-presenting cells (APC) the convergence of MVB towards the microtubule organization center (MTOC), and MTOC polarization to the IS, are involved in polarized exosome secretion at the synaptic cleft. This specialized mechanism provides the immune system with a finely-tuned strategy to increase the specificity and efficiency of crucial secretory effector functions of B and T lymphocytes. Since inducible exosome secretion by antigen-receptors is a critical and unique feature of the immune system this entry considers the study of the traffic events leading to polarized exosome secretion at the IS and some of their biological consequences.
  • 3.1K
  • 29 Oct 2020
Topic Review
Applications of Lignin in Wood
Lignin is the most abundant aromatic polymer in nature and the second most abundant biomass on earth. In paper production and other processes, lignin is obtained as a side product and mainly used energetically. The use of lignin in wood adhesives or for wood modification has received a lot of scientific attention.
  • 3.1K
  • 25 May 2021
Topic Review
DNA-Based Biosensors
Due to superior biocompatibility, thermal stability, and alternative functionalization, deoxyribonucleic acid (DNA) is becoming a fascinating biological material used for biosensing. It is widely acknowledged that DNA and its assembly structure can be applied for detecting specific targets, including nucleic acids, proteins, metal ions, and small biological molecules. With the development of DNA nanotechnology, dynamic networks based on DNA hybridization can be used to amplify the signals of biosensors.
  • 3.1K
  • 07 Apr 2022
Topic Review
Gorgonopsia
Gorgonopsia (from the Greek Gorgon, a mythological beast, and óps 'aspect') is an extinct clade of sabre-toothed therapsids from the Middle to Upper Permian roughly 265 to 252 million years ago. They are characterised by a long and narrow skull, as well as elongated upper and sometimes lower canine teeth and incisors which were likely used as slashing and stabbing weapons. Postcanine teeth are generally reduced or absent. For hunting large prey, they possibly used a bite-and-retreat tactic, ambushing and taking a debilitating bite out of the target, and following it at a safe distance before its injuries exhausted it, whereupon the gorgonopsian would grapple the animal and deliver a killing bite. They would have had an exorbitant gape, possibly in excess of 90°, without having to unhinge the jaw. They markedly increased in size as time went on, growing from small skull lengths of 10–15 cm (4–6 in) in the Middle Permian to bear-like proportions of up to 60 cm (2 ft) in the Upper Permian. The latest gorgonopsians, Rubidgeinae, were the most robust of the group and could produce especially powerful bites. Gorgonopsians are thought to have been completely terrestrial and could walk with a semi-erect gait, with a similar terrestrial locomotory range as modern crocodilians. They may have been more agile than their prey items, but were probably inertial homeotherms rather than endotherms unlike contemporary therocephalians and cynodonts, and thus were probably comparatively less active. Though gorgonopsians were able to maintain a rather high body temperature, it is unclear if they would have also had sweat glands or fur (and by extension whiskers and related structures). Their brains were reminiscent of modern reptilian brains, rather than those of living mammals. Most species may have been predominantly diurnal (active during the day) though some could have been crepuscular (active at dawn or dusk) or nocturnal (active at night). They are thought to have had binocular vision, a parietal eye (which detects sunlight and maintains circadian rhythm), a keen sense of smell, a functional vomeronasal organ ("Jacobson's organ"), and possibly a rudimentary eardrum. The major therapsid groups had all evolved by 275 million years ago from a "pelycosaur" ancestor (a poorly defined group including all synapsids which are not therapsids). The therapsid takeover from pelycosaurs took place by the Middle Permian as the world progressively became drier. Gorgonopsians rose to become apex predators of their environments following the Capitanian mass extinction event which killed off the dinocephalians and some large therocephalians after the Middle Permian. Despite the existence of a single continent during the Permian, Pangaea, gorgonopsians have only been found in the Karoo Supergroup (primarily in South Africa, but also in Tanzania, Zambia, and Malawi), the Moradi Formation of Niger, and western Russia, with probable remains known from the Kundaram Formation of India. These places were semi-arid areas with highly seasonal rainfall. Gorgonopsian genera vary very little, and consequently, many species have been named based on flimsy and likely age-related differences since their discovery in the late 19th century, and the group has been subject to several taxonomic revisions. They became extinct during a phase of the Permian–Triassic extinction event taking place at the very end of the Permian, in which major volcanic activity (which would produce the Siberian Traps) and resultant massive spike in greenhouse gases caused rapid aridification due to temperature spike, acid rain, frequent wildfires, and potential breakdown of the ozone layer. The large predatory niches would be taken over by the archosaurs (namely crocodilians and dinosaurs) in the Mesozoic.
  • 3.1K
  • 17 Oct 2022
Topic Review
ZnO and TiO2 Green Synthesis
Over the last two decades, oxide nanostructures have been continuously evaluated and used in many technological applications. The advancement of the controlled synthesis approach to design desired morphology is a fundamental key to the discipline of material science and nanotechnology. These nanostructures can be prepared via different physical and chemical methods; however, a green synthesis approach is a promising way to produce these nanostructures with desired properties with time and energy savings and/or less use of hazardous chemicals. In this regard, ZnO and TiO2 nanostructures are prominent candidates for various applications given their thermal stability, non-toxicity and cost-effective. 
  • 3.1K
  • 06 May 2021
Topic Review
Hop
Hops is considered a short-day, temperate species, so the major challenge for the development of hop cultivation in Brazil, with high-yield capacity and with local typicity of bitterness and aroma, is the adaptation of cultivars to the photoperiod conditions in subtropical regions. 
  • 3.1K
  • 20 May 2022
Topic Review
Electron (Rocket)
Electron is a two-stage orbital expendable launch vehicle (with an optional third stage) developed by the American aerospace company Rocket Lab to service the commercial small satellite launch segment. Its Rutherford engines, manufactured in California , are the first electric-pump-fed engine to power an orbital rocket. In December 2016, Electron completed flight qualification. The first rocket was launched on 25 May 2017, reaching space but not achieving orbit due to a glitch in communication equipment on the ground. During its second flight on 21 January 2018, Electron reached orbit and deployed three CubeSats. The first commercial launch of Electron, and the third launch overall, occurred on 11 November 2018.
  • 3.1K
  • 08 Oct 2022
Topic Review
Woolly Mammoth (Mammuthus primigenius)
The woolly mammoth (Mammuthus primigenius) was a large, elephant-like mammal that lived during the Ice Age. It belonged to the family Elephantidae, which includes modern elephants. It was characterized by its long, curved tusks, thick fur, and adaptations to extremely cold climates. The woolly mammoth was one of the last surviving members of the Mammuthus genus and played a significant role in Pleistocene ecosystems. Its extinction around 4,000 years ago was due to a combination of climate change and human activity.
  • 3.1K
  • 19 Mar 2025
Topic Review
Bisphenols
Bisphenols (BPs), and especially bisphenol A (BPA), are known endocrine disruptors (EDCs), capable of interfering with estrogen and androgen activities, as well as being suspected of other health outcomes.
  • 3.1K
  • 28 Oct 2020
Topic Review
Carboxylases for CO2 Biotransformation
The rapid growth of atmospheric CO2 concentration by continuous consumption of fossil fuels is one of the main causes of global warming. Turning CO2 into fuels and chemicals through biotransformation offers a win-win strategy to both decrease atmospheric CO2 and efficiently exploit carbon resources. The overall efficiency of CO2 biotransformation in vitro and CO2 assimilation in vivo is generally determined by the biochemical properties of carboxylases. Herein, we summarized carboxylases based on catalytic mechanism and CO2 biotransformation in vitro and CO2 assimilation in vivo based on newly mined or designed carboxylases. 
  • 3.1K
  • 04 Mar 2021
Topic Review
Application of Ground Heat Exchangers
Geothermal energy is a widely available, constant source of renewable energy that has shown great potential as an alternative source of energy in achieving global energy sustainability and environment protection. When exploiting geothermal energy, whether is for heating or cooling of buildings, a ground heat exchanger (GHE) is the most important component, whose performance can be easily improved by following the latest design aspects. 
  • 3.1K
  • 26 May 2021
Topic Review
Contributions of Chromatography to the Science Progress
Chromatography was born approximately one century ago and has undergone outstanding technological improvements in innovation, research, and development since then that has made it fundamental to advances in knowledge at different levels, with a relevant impact on the well-being and health of individuals. Chromatography boosted a comprehensive and deeper understanding of the complexity and diversity of human–environment interactions and systems, how these interactions affect our life, and the several societal challenges currently facing, namely those related to the sustainability of our planet and the future generations. From the life sciences, which allowed to identify endogenous metabolites relevant to disease mechanisms, to the OMICS field, nanotechnology, clinical and forensic analysis, drug discovery, environment, and “foodprint”, among others, the wide range of applications of today’s chromatographic techniques is impressive. This is fueled by a great variability of powerful chromatographic instruments currently available, with very high sensitivity, resolution, and identification capacity, that provide a strong basis for an analytical platform able to support the challenging demands of the postgenomic and post COVID-19 eras. 
  • 3.1K
  • 02 Sep 2022
Topic Review
Characteristics of Vitamin E
Vitamin E is a fat-soluble organic micronutrient that helps to preserve human health. Its main function is likely that of a radical scavenger protecting biological membranes from lipid peroxidation. Vegetable oils, such as wheat germ, sunflower, corn germ, soybean, and rapeseed, are the primary dietary source of vitamin E for humans. It is also found in some nuts, fruits, and vegetables, such as almonds, avocados, spinach, and kale.
  • 3.1K
  • 16 Sep 2022
Biography
Juan Martín Maldacena
Juan Martín Maldacena (September 10, 1968 ) is an Argentine theoretical physicist and the Carl P. Feinberg Professor in the School of Natural Sciences at the Institute for Advanced Study.[1] He has made significant contributions to the foundations of string theory and quantum gravity. His most famous discovery is the AdS/CFT correspondence, a realization of the holographic principle in string t
  • 3.1K
  • 24 Nov 2022
Topic Review
Poly(vinylidene fluoride) Phase Structure and Identification
Poly(vinylidene fluoride) (PVDF) is one of the most interesting semicrystalline polymers and is often used in sensors, actuators, energy harvesters, etc., because of its high biocompatibility, film-forming ability, low cost, excellent chemical stability, and good electroactive characteristics, including piezo-, pyro-, and ferro-electric properties.
  • 3.1K
  • 30 Jun 2023
Topic Review
Deep Eutectic Solvents Systems
Deep eutectic solvents (DESs) represent an emergent class of green designer solvents that find numerous applications in different aspects of chemical synthesis. A particularly appealing aspect of DES systems is their simplicity of preparation, combined with inexpensive, readily available starting materials to yield solvents with appealing properties (negligible volatility, non-flammability and high solvation capacity). 
  • 3.1K
  • 07 Jul 2021
Topic Review
Climate Oscillation
A climate oscillation or climate cycle is any recurring cyclical oscillation within global or regional climate, and is a type of climate pattern. These fluctuations in atmospheric temperature, sea surface temperature, precipitation or other parameters can be quasi-periodic, often occurring on inter-annual, multi-annual, decadal, multidecadal, century-wide, millennial or longer timescales. They are not perfectly periodic and a Fourier analysis of the data does not give a sharp spectrum. A prominent example is the El Niño Southern Oscillation, involving sea surface temperatures along a stretch of the equatorial Central and East Pacific Ocean and the western coast of tropical South America, but which affects climate worldwide. Records of past climate conditions are recovered through geological examination of proxies, found in glacier ice, sea bed sediment, tree ring studies or otherwise.
  • 3.1K
  • 09 Nov 2022
Topic Review
Electromigration
Electromigration is the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applications where high direct current densities are used, such as in microelectronics and related structures. As the structure size in electronics such as integrated circuits (ICs) decreases, the practical significance of this effect increases.
  • 3.1K
  • 24 Nov 2022
Topic Review
Premature Ovarian Insufficiency and Infertility
Reproductive aging is on the rise globally and inseparable from the entire aging process. An extreme form of reproductive aging is premature ovarian insufficiency (POI), which to date has mostly been of idiopathic etiology, thus hampering further clinical applications and associated with enormous socioeconomic and personal costs. In the field of reproduction, timely diagnosis with a clear understanding of the various comorbidities that can arise from estrogen deficiency and the important functional role of inflammation-induced ovarian deterioration are research hotspots for appropriate counseling and preventing this prematurely ovarian aging disease. It is evident that more research is required to allow pre-emptive identification of the at-risk population and to identify mechanisms that, if addressed promptly, can prolong ovarian function and fertility.
  • 3.1K
  • 30 Dec 2022
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