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Topic Review
Carbon-LiFePO4 Cathodes for Lithium-Ion Batteries
Li-ion batteries are in demand due to technological advancements in the electronics industry; thus, expanding the battery supply chain and improving its electrochemical performance is crucial. Carbon materials are used to increase the cyclic stability and specific capacity of cathode materials, which are essential to batteries. LiFePO4 (LFP) cathodes are generally safe and have a long cycle life. However, the common LFP cathode has a low inherent conductivity, and adding a carbon nanomaterial significantly influences how well it performs electrochemically.
  • 895
  • 28 Nov 2022
Topic Review
Thia-Michael Reaction
While the Michael addition has been employed for more than 130 years for the synthesis of a vast diversity of compounds, the reversibility of this reaction when heteronucleophiles are involved has been generally less considered. First applied to medicinal chemistry, the reversible character of the hetero-Michael reactions has been explored for the synthesis of Covalent Adaptable Networks (CANs), in particular the thia-Michael reaction and more recently the aza-Michael reaction. In these cross-linked networks, exchange reactions take place between two Michael adducts by successive dissociation and association steps. In order to understand and precisely control the exchange in these CANs, it is necessary to get an insight into the critical parameters influencing the Michael addition and the dissociation rates of Michael adducts by reconsidering previous studies on these matters. 
  • 1.1K
  • 28 Nov 2022
Topic Review
Enzymes Related to Early Skin-Aging
Skin is the largest organ of the human body and is a great shield, as it protects it from external infections (environmental and chemical pollutants) as well as from UV irradiation. However, it is vulnerable since its degradation can occur both due to extrinsic and intrinsic factors, leading to early aging. Among all, extrinsic skin aging, called photoaging, is a remarkable result of oxidative stress caused by UV irradiation. In addition, reactive oxygen species (ROS) have also been found to contribute to skin aging, as they are produced in skin cells through UV irradiation, although at low concentrations they could be beneficial for some signaling pathways. Environmental and chemical pollutants also produce ROS, triggering a number of pathologies. Skin’s connective tissue includes a number of constituents, including collagen fibrils, elastic fibers, glycoproteins, and glycosaminoglycans. Among all, proteins like elastin, collagen, the glycosaminoglycan hyaluronic acid, and a polymeric pigment called melanin play pivotal roles in the regulation of skin’s elasticity as well as its protection against UV irradiation.
  • 578
  • 28 Nov 2022
Topic Review
GO/TiO2-Related Nanocomposites as Photocatalysts in Wastewater Treatment
Photocatalysis is a more recently applied concept and is proven to be able to completely remove and degrade pollutants into simpler organic compounds. Titanium dioxide (TiO2) is a fine example of a photocatalyst owing to its cost-effectiveness and superb efficiency. However, issues such as the high recombination rate of photogenerated electrons along with positive holes while being only limited to UV irradiation need to be addressed. Carbonaceous materials such as graphene oxide (GO) can overcome such issues by reducing the recombination rate and providing a platform for adsorption accompanied by photocatalytic degradation of TiO2.
  • 535
  • 28 Nov 2022
Topic Review
Laser Dynamic Compression in Diamond Anvil Cells
The field of high-pressure materials research has grown steadily, with many remarkable discoveries having been made. Recent progress in laser material processing within diamond anvil cells (L-DACs); researchers focus on the practice of laser-driven dynamic compression within diamond anvil cells (i.e., LDC–DAC experimentation).
  • 691
  • 28 Nov 2022
Topic Review
Mars Oxygen ISRU Experiment
The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) is a technology demonstration on the NASA Mars 2020 rover Perseverance investigating the production of oxygen on Mars. On April 20, 2021, MOXIE produced oxygen from carbon dioxide in the Martian atmosphere by using solid oxide electrolysis. This was the first experimental extraction of a natural resource from another planet for human use. The technology may be scaled up for use in a human mission to the planet to provide breathable oxygen, oxidizer, and propellant; water may also be produced by combining the produced oxygen with hydrogen. The experiment was a collaboration between the Massachusetts Institute of Technology, the Haystack Observatory, the NASA/Caltech Jet Propulsion Laboratory, and other institutions.
  • 591
  • 28 Nov 2022
Topic Review
Types of Membrane Vesicles Acting as Tumor Vaccines
Membrane vesicles, a group of nano- or microsized vesicles, can be internalized or interact with the recipient cells, depending on their parental cells, size, structure and content. Membrane vesicles fuse with the target cell membrane, or they bind to the receptors on the cell surface, to transfer special effects. Based on versatile features, they can modulate the functions of immune cells and therefore influence immune responses. In the field of tumor therapeutic applications, phospholipid-membrane-based nanovesicles attract increased interest. Academic institutions and industrial companies are putting in effort to design, modify and apply membrane vesicles as potential tumor vaccines contributing to tumor immunotherapy. 
  • 480
  • 28 Nov 2022
Topic Review
Nucleic Acid
Nucleic acids are the biopolymers, or small biomolecules, essential to all known forms of life. The term nucleic acid is the overall name for DNA and RNA. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. If the sugar is a compound ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid). Nucleic acids are the most important of all biomolecules. They are found in abundance in all living things, where they function to create and encode and then store information in the nucleus of every living cell of every life-form organism on Earth. In turn, they function to transmit and express that information inside and outside the cell nucleus—to the interior operations of the cell and ultimately to the next generation of each living organism. The encoded information is contained and conveyed via the nucleic acid sequence, which provides the 'ladder-step' ordering of nucleotides within the molecules of RNA and DNA. Strings of nucleotides are bonded to form helical backbones—typically, one for RNA, two for DNA—and assembled into chains of base-pairs selected from the five primary, or canonical, nucleobases, which are: adenine, cytosine, guanine, thymine, and uracil; note, thymine occurs only in DNA and uracil only in RNA. Using amino acids and the process known as protein synthesis, the specific sequencing in DNA of these nucleobase-pairs enables storing and transmitting coded instructions as genes. In RNA, base-pair sequencing provides for manufacturing new proteins that determine the frames and parts and most chemical processes of all life forms.
  • 1.7K
  • 28 Nov 2022
Topic Review
Inhalant
Inhalants are a broad range of household and industrial chemicals whose volatile vapors or pressurized gases can be concentrated and breathed in via the nose or mouth to produce intoxication, in a manner not intended by the manufacturer. They are inhaled at room temperature through volatilization (in the case of gasoline or acetone) or from a pressurized container (e.g., nitrous oxide or butane), and do not include drugs that are sniffed after burning or heating. For example, amyl nitrite (poppers), nitrous oxide and toluene – a solvent widely used in contact cement, permanent markers, and certain types of glue – are considered inhalants, but smoking tobacco, cannabis, and crack are not, even though these drugs are inhaled as smoke or vapor. While a few inhalants are prescribed by medical professionals and used for medical purposes, as in the case of inhaled anesthetics and nitrous oxide (an anxiolytic and pain relief agent prescribed by dentists), this article focuses on inhalant use of household and industrial propellants, glues, fuels, and other products in a manner not intended by the manufacturer, to produce intoxication or other psychoactive effects. These products are used as recreational drugs for their intoxicating effect. According to a 1995 report by the National Institute on Drug Abuse, the most serious inhalant use occurs among homeless children and teenagers who "... live on the streets completely without family ties." Inhalants are the only substance used more by younger teenagers than by older teenagers. Inhalant users inhale vapor or aerosol propellant gases using plastic bags held over the mouth or by breathing from a solvent-soaked rag or an open container. The practices are known colloquially as "sniffing", "huffing" or "bagging". The effects of inhalants range from an alcohol-like intoxication and intense euphoria to vivid hallucinations, depending on the substance and the dose. Some inhalant users are injured due to the harmful effects of the solvents or gases or due to other chemicals used in the products that they are inhaling. As with any recreational drug, users can be injured due to dangerous behavior while they are intoxicated, such as driving under the influence. In some cases, users have died from hypoxia (lack of oxygen), pneumonia, heart failure or arrest, or aspiration of vomit. Brain damage is typically seen with chronic long-term use of solvents as opposed to short-term exposure. Even though many inhalants are legal, there have been legal actions taken in some jurisdictions to limit access by minors. While solvent glue is normally a legal product, a Scottish court has ruled that supplying glue to children is illegal if the store knows the children intend to inhale the glue. In the US, thirty-eight of 50 states have enacted laws making various inhalants unavailable to those under the age of 18 or making inhalant use illegal.
  • 1.2K
  • 28 Nov 2022
Topic Review
Surface-Enhanced Raman Spectroscopy Clinical Applications
Surface-enhanced Raman spectroscopy (SERS) has become a powerful analytical technique, widely used for the detection of various analytes at low concentrations. In comparison to many other analytical methods, SERS is a highly sensitive, fast, humidity-independent analytical method with a high potential for multiplexed detection. SERS advantages over fluorescence, for instance, include good robustness/low photobleaching and capabilities for label-free detection, while SERS can be applied for in situ monitoring, in vivo biosensing, and even single molecule detection. Due to these advantages, SERS is widely used in molecular biology, biomedicine, and environmental science. Furthermore, SERS is capable of detecting single molecules Factors such as pH, the degree of nanoparticle (NP) aggregation, temperature and substrate composition can have a significant impact on the reproducibility and enhancement of SERS applications.
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