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Topic Review
Hydrogen Bond Energy
Hydrogen bonds (HBs) play a crucial role in many physicochemical and biological processes. Theoretical methods can reliably estimate the intermolecular HB energies. Quantifying an intramolecular hydrogen bond (IHB) strength is not as straightforward as the intermolecular one. The main difficulty lies in isolating the X–H···Y interaction present within a molecule than in a dimer or a complex. However, the procedure discussed (viz. molecular tailoring approach) in this article, allows the generation of fragments so that the atoms/functional groups involved in the HB formation are parts of two different fragments. The energies of these fragments are added or substracted, using the inclusion exclusion principle in set theory, to obtained the energy of HB bond.
  • 1.4K
  • 19 May 2021
Topic Review
Per- and Polyfluoroalkyl Substances
Per- and polyfluoroalkyl substances (PFAS) are a family of synthetic fluorinated organic compounds whose widespread use and resistance to biodegradation have led to their accumulation in the environment, causing growing concerns over their impact on humans.
  • 1.4K
  • 15 Jan 2021
Topic Review
Shape Memory Polyurethane
The inherent capability to deform and reform in a predefined environment is a unique property existing in shape memory polyurethane. The intrinsic shape memory ability of the polyurethane is due to the presence of macro domains of soft and hard segments in its bulk, which make this material a potential candidate for several applications. This entry is focused on manifesting the applicability of shape memory polyurethane and its composites/blends in various domains, especially to human health such as shielding of electromagnetic interference, medical bandage development, bone tissue engineering, self-healing, implants development, etc. 
  • 1.4K
  • 30 Oct 2020
Topic Review
Available Sampling Methods for Plastic Waste
Given the rapid development of plastics recycling in recent years, the need for guidelines for sampling and material characterization is steadily emerging. However, there still exists a considerable scarcity of methods that enable proper material data acquisition. It was found that neither the literature nor the standards provide a comprehensive practice that considers the distinctive characteristics of plastic waste and applies it to different situations along the value chain. Two variants of the proposed plan were evaluated based on the flake size distribution and the apparent density of four different pretreated polyolefin (PO) waste materials. Combining stratified random sampling with composite sampling yields a good sampling technique for rigid PO waste. Moreover, the analysis of a composite sample adequately conveys the true material properties of a sublot or lot.
  • 1.4K
  • 31 Aug 2022
Topic Review
Copper Complexes as Topoisomerases Inhibitors
Organometallics, such as copper compounds, are cancer chemotherapeutics used alone or in combination with other drugs. A group of copper complexes exerts an effective inhibitory action on topoisomerases, which participate in the regulation of DNA topology. Copper complexes of topoisomerase inhibitors work by different molecular mechanisms that have repercussions on the cell cycle checkpoints and death effectors. 
  • 1.4K
  • 14 Oct 2020
Topic Review
Microbial Degradation of Rubber: Actinobacteria
Rubber is an essential part of our daily lives with thousands of rubber-based products being made and used. Natural rubber undergoes chemical processes and structural modifications, while synthetic rubber, mainly synthetized from petroleum by-products are difficult to degrade safely and sustainably. The most prominent group of biological rubber degraders are Actinobacteria. Rubber degrading Actinobacteria contain rubber degrading genes or rubber oxygenase known as latex clearing protein (lcp). Rubber is a polymer consisting of isoprene, each containing one double bond. The degradation of rubber first takes place when lcp enzyme cleaves the isoprene double bond, breaking them down into the sole carbon and energy source to be utilized by the bacteria. Actinobacteria grow in diverse environments, and lcp gene containing strains have been detected from various sources including soil, water, human, animal, and plant samples. 
  • 1.4K
  • 23 Jun 2021
Topic Review
Drug Delivery for Cardiovascular Diseases
Cardiovascular diseases (CVDs) are the leading cause of death globally, taking an estimated 17.9 million lives each year, representing one third of global mortality. As existing therapies still have limited success, due to the inability to control the biodistribution of the currently approved drugs, the quality of life of these patients is modest. The advent of nanomedicine has brought new insights in innovative treatment strategies.
  • 1.4K
  • 08 Dec 2020
Topic Review
Tannylated Calcium Carbonate Materials
Calcium carbonate (CaCO3)-based materials have received notable attention for biomedical applications owing to their safety and beneficial characteristics, such as pH sensitivity, carbon dioxide (CO2) gas generation, and antacid properties. Herein, to additionally incorporate antioxidant and anti-inflammatory functions, we prepared tannylated CaCO3 (TA-CaCO3) materials using a simple reaction between tannic acid (TA), calcium (Ca2+), and carbonate (CO32−) ions. TA-CaCO3 synthesized at a molar ratio of 1:75 (TA:calcium chloride (CaCl2)/sodium carbonate (Na2CO3)) showed 3–6 μm particles, comprising small nanoparticles in a size range of 17–41 nm. The TA-CaCO3 materials could efficiently neutralize the acid solution and scavenge free radicals. 
  • 1.4K
  • 12 May 2021
Topic Review
Factors Affecting Electrospinning
Electrospinning can produce continuous nanofibers from a variety of materials. Processional, physical, systemic, and solution parameters, among others, impact the fiber morphology and properties of electrospun fibers.
  • 1.4K
  • 13 Apr 2023
Topic Review
Technologies for Detecting Oxygen Vacancies
A perovskite catalyst combined with various advanced oxidation processes (AOPs) to treat organic wastewater attracted extensive attention. The physical and chemical catalytic properties of perovskite were largely related to oxygen vacancies (OVs). OVs were able to alter the chemical, physical, and electronic properties of materials, so they became one of the most important research subjects. It was usually necessary to observe and analyze the phenomenon caused by OVs; however, due to their low concentration and short existence time, OVs were normally not visible to the naked eye. The relative concentration of OVs ranged from PPM to tens of atomic percent, a condition that was difficult to find a fitting experimental plan to characterize and distinguish OVs. 
  • 1.4K
  • 02 Feb 2023
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