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Topic Review
Royleanones
Plants have been used for centuries to treat several illnesses. The Plectranthus genus has a vast variety of species that has allowed the isolation of cytotoxic compounds with notable activities.The abietane diterpenes 6,7-dehydroroyleanone (DeRoy), 7alfa-acetoxy-6 -hydroxyroyleanone (Roy), and Parvifloron D (ParvD) were obtained from Plectranthus spp. and showed promising biological activities, such as cytotoxicity on several cancer cell lines, including cancer stem cell inducing sphere cells. In silico studies comparied the possible binding modes of active compounds and derivatives against different PKC isoforms alpha/beta/delta/iota/lambda/theta/zeta.
  • 770
  • 27 Oct 2020
Topic Review
Molecularly Imprinted Nanoparticles Based Sensor
The development of a sensor based on molecularly imprinted polymer nanoparticles (nanoMIPs) and electrochemical impedance spectroscopy (EIS) for the detection of trace levels of cocaine is described in this paper. NanoMIPs for cocaine detection, synthesized using a solid phase, were applied as the sensing element. The nanoMIPs were first characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering and found to be ~148.35 ± 24.69 nm in size, using TEM. The nanoMIPs were then covalently attached to gold screen-printed electrodes and a cocaine direct binding assay was developed and optimized, using EIS as the sensing principle. EIS was recorded at a potential of 0.12 V over the frequency range from 0.1 Hz to 50 kHz, with a modulation voltage of 10 mV. The nanoMIPs sensor was able to detect cocaine in a linear range between 100 pg mL-1 and 50 ng mL-1 (R2 = 0.984; p-value = 0.00001) and with a limit of detection of 0.24 ng mL-1 (0.70 nM). The sensor showed no cross-reactivity toward morphine and a negligible response toward levamisole after optimizing the sensor surface blocking and assay conditions. The developed sensor has the potential to offer a highly sensitive, portable and cost-effective method forcocaine detection.
  • 770
  • 02 Nov 2020
Topic Review
Synthesis of Organoclays
Organoclays are effective adsorbents, prepared by intercalation or surface grafting of clays and clay minerals with various organic compounds. Organoclays have important practical applications as adsorbents of a wide range of organic pollutants and some inorganic contaminants.
  • 770
  • 06 Aug 2021
Topic Review
Zinc Oxide Doped with Transition Metal Ions
As an excellent semiconductor photocatalyst, zinc oxide is widely used in the field of photocatalysis and is regarded as one of the most reliable materials to solve environmental problems. However, because its band gap energy limits the absorption of visible light and reduces the efficiency of catalytic degradation, it needs to be doped with other substances or compounded with other substances and precious metal. 
  • 770
  • 11 Nov 2022
Topic Review Peer Reviewed
Fluorescence in Smart Textiles
Fluorescence has been identified as an advantageous feature in smart fabrics, notably for the protection of humans during outdoor athletic activities, as well as for preventing counterfeiting and determining authenticity. Fluorescence in smart fabrics is achieved using dendrimers, rare earth metal compounds, and fluorescent dye. The principal method for producing fluorescent fabrics is to immerse the sample in a solution containing fluorescent agents. However, covalent connections between fluorophores and textile substates should be established to improve the stability and intensity of the fluorescent characteristics. Fabric can be fluorescent throughout, or fluorescent fibers can be woven directly into the textile structures, made of natural (cotton, silk) or synthetic (polyamide- and polyester-based) fibers, into a precise pathway that becomes visible under ultraviolet irradiation.
  • 770
  • 14 Nov 2023
Topic Review
Lyotropic Liquid Crystalline Nanostructures as Drug Delivery Systems
Lyotropic liquid crystals (LLC) result from the self-assembly process of amphiphilic molecules, such as lipids, into water, being organized in different mesophases. The non-lamellar formed mesophases, such as bicontinuous cubic (forming cubosomes) and inverse hexagonal (forming hexosomes), attract great scientific interest in the field of pharmaceutical nanotechnology. Non-lamellar LLC nanosystems can be utilized as drug delivery nanosystems, as well as for protein, peptide, and nucleic acid delivery. They exhibit major advantages, including stimuli-responsive properties for the “on demand” drug release and the ability for controlled release, by manipulating their internal conformation properties and their administration by different routes. Moreover, non-lamellar LLC nanosystems exhibit unique adjuvant properties to activate the immune system, being ideal for the development of novel vaccines. 
  • 770
  • 29 Jun 2022
Topic Review
Nanocrystalline Doped Diamond for Photocatalytic
Nitrogen impurity has been introduced in diamond film to produce a nitrogen vacancy center (NV center) toward the solvated electron-initiated reduction of N2 to NH3 in liquids, giving rise to extend the wavelength region beyond the diamond’s band. Scanning electron microscopy and X-ray diffraction demonstrate the formation of the nanocrystalline nitrogen-doped diamond with an average diameter of ten nanometers. Raman spectroscopy and PhotoLuminescence (PL) spectrum show characteristics of the NV0 and NV− charge states. Measurements of photocatalytic activity using supraband (λ < 225 nm) gap and sub-band gap (λ > 225 nm) excitation show the nitrogen-doped diamond significantly enhanced the ability to reduce N2 to NH3 compared to the polycrystalline diamond and single crystal diamond (SCD). Our results suggest an important process of internal photoemission, in which electrons are excited from negative charge states into conduction band edges, presenting remarkable photoinitiated electrons under ultraviolet and visible light. Other factors, including transitions between defect levels and processes of reaction, are also discussed. This approach can be especially advantageous to such as N2 and CO2 that bind only weakly to most surfaces and high energy conditions.
  • 769
  • 16 Oct 2020
Topic Review
Permafrost Carbon Cycle
The permafrost carbon cycle is a sub-cycle of the larger global carbon cycle. Permafrost is defined as subsurface material that remains below 0o C (32o F) for at least two consecutive years. Because permafrost soils remain frozen for long periods of time, they store large amounts of carbon and other nutrients within their frozen framework during that time. Permafrost represents a large carbon reservoir that is seldom considered when determining global terrestrial carbon reservoirs. Recent and ongoing scientific research however, is changing this view. The permafrost carbon cycle (Arctic Carbon Cycle) deals with the transfer of carbon from permafrost soils to terrestrial vegetation and microbes, to the atmosphere, back to vegetation, and finally back to permafrost soils through burial and sedimentation due to cryogenic processes. Some of this carbon is transferred to the ocean and other portions of the globe through the global carbon cycle. The cycle includes the exchange of carbon dioxide and methane between terrestrial components and the atmosphere, as well as the transfer of carbon between land and water as methane, dissolved organic carbon, dissolved inorganic carbon, particulate inorganic carbon and particulate organic carbon.
  • 769
  • 04 Nov 2022
Topic Review
Self-Assembling Nucleobase-Containing Peptides
The self-assembly of bio-inspired nanomaterials and biological nanostructures confers new properties and functions to conjugated biomaterials, such as the ability to respond to external stimuli. Nucleobase-containing peptides can be considered as aromatic peptides and, similar to these self-assembling structures, they can lead to interesting functional nanostructures as hereafter explained. Self-assembling nucleopeptides can form hydrogels based on supramolecular structures held by non-covalent molecular interactions occurring between the peptide segments, as well as π–π stacking and Watson–Crick interactions via complementary DNA bases.
  • 769
  • 16 Jun 2021
Topic Review
Stacking
In chemistry, pi stacking (also called π–π stacking) refers to attractive, noncovalent interactions between aromatic rings, since they contain pi bonds. These interactions are important in nucleobase stacking within DNA and RNA molecules, protein folding, template-directed synthesis, materials science, and molecular recognition, although new research suggests that pi stacking may not be operative in some of these applications. Despite intense experimental and theoretical interest, there is no unified description of the factors that contribute to pi stacking interactions.
  • 769
  • 31 Oct 2022
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