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Topic Review
Inorganic Nanoparticles for Cancer Treatment
The application of porphyrins and their derivatives have been investigated extensively over the past years for phototherapy cancer treatment. Phototherapeutic Porphyrins have the ability to generate high levels of reactive oxygen with a low dark toxicity and these properties have made them robust photosensitizing agents. In recent years, Porphyrins have been combined with various nanomaterials in order to improve their bio-distribution. These combinations allow for nanoparticles to enhance photodynamic therapy (PDT) cancer treatment and adding additional nanotheranostics (photothermal therapy—PTT) as well as enhance photodiagnosis (PDD) to the reaction. This review examines various porphyrin-based inorganic nanoparticles developed for phototherapy nanotheranostic cancer treatment over the last three years (2017 to 2020). Furthermore, current challenges in the development and future perspectives of porphyrin-based nanomedicines for cancer treatment are also highlighted.
  • 2.3K
  • 28 Oct 2020
Topic Review
The Hydrophobic Effects
Hydrophobic interactions are involved in and believed to be the fundamental driving force of many chemical and biological phenomena in aqueous environments.
  • 2.3K
  • 01 Nov 2022
Topic Review
Application of Quantum Mechanics/Molecular Mechanics Methodologies to Metalloproteins
The multiscaling quantum mechanics/molecular mechanics (QM/MM) approach was introduced in 1976, while the extensive acceptance of this methodology started in the 1990s. The combination of QM/MM approach with molecular dynamics (MD) simulation, otherwise known as the QM/MM/MD approach, is a powerful and promising tool for the investigation of chemical reactions’ mechanism of complex molecular systems, drug delivery, properties of molecular devices, organic electronics, etc. Applications of the QM/MM methodologies on metalloproteins are presented.  
  • 2.2K
  • 05 May 2022
Topic Review
Photocathode Materials
Photoelectrochemical water splitting is a promising approach to sustainable hydrogen production with no carbon emissions. Hydrogen being a future fuel to coming human generations is of utmost importance. The photocathodes in a photoelectrochemical (PEC) water-splitting cell are essential for the direct evolution of hydrogen. Among the known photocathodes, Cu-based p-type semiconducting materials are the most promising photo-absorber materials owing to their low-cost, low toxicity, natural abundance, suitable band-gaps, and favorable band edges for reduction. 
  • 2.2K
  • 08 Nov 2022
Topic Review
Graphitic Carbon Nitride as a Photocatalyst
Carbon nitride, albeit known for a long time, has been tested as a photocatalyst only since 2009. Extensive searches for reliable visible-light-activated semiconductor photocatalysts revealed the next generation photocatalyst based on a polymeric semiconductor—graphitic carbon nitride.
  • 2.2K
  • 29 Dec 2022
Topic Review
Nanoparticle Exsolution on Perovskite-Based Catalysts
In heterogeneous catalysis, surfaces decorated with uniformly dispersed, catalytically-active (nano)particles are a key requirement for excellent performance. Besides standard catalyst preparation routines—with limitations in controlling catalyst surface structure (i.e., particle size distribution or dispersion)—exsolution is a potential novel and time efficient route to precisely tailor catalyst surface morphology and composition of perovskites: Perovskite-type oxides of nominal composition ABO3 with transition metal cations on the B-site can exsolve the B-site transition metal upon controlled reduction. In this exsolution process, the transition metal emerges from the oxide lattice and migrates to the surface where it forms catalytically active nanoparticles. Doping the B-site with reducible and catalytically highly active elements, offers the opportunity of tailoring properties of exsolution catalysts.
  • 2.1K
  • 01 Nov 2020
Topic Review
MALDI Mass Spectrometry
MALDI Mass Spectrometry is an analytical technique able to study the complex interdependency between chemical interaction and structural conformation of several protein based assemblies.
  • 2.1K
  • 16 Nov 2020
Topic Review
CO2 Hydrogenation to Methanol
High-efficiency utilization of CO2 facilitates the reduction of CO2 concentration in the global atmosphere and hence the alleviation of the greenhouse effect. The catalytic hydrogenation of CO2 to produce value-added chemicals exhibits attractive prospects by potentially building energy recycling loops.
  • 2.1K
  • 15 Apr 2022
Topic Review
2-Oxocarboxylic Acids
Atmospheric organic aerosols play a major role in climate, demanding a better understanding of their formation mechanisms by contributing multiphase chemical reactions with the participation of water. The sunlight driven aqueous photochemistry of small 2-oxocarboxylic acids is a potential major source of organic aerosol, which prompted the investigations into the mechanisms of glyoxylic acid and pyruvic acid photochemistry reviewed here. While 2-oxocarboxylic acids can be contained or directly created in the particles, the majorities of these abundant and available molecules are in the gas phase and must first undergo the surface uptake process to react in, and on the surface, of aqueous particles.
  • 2.1K
  • 02 Jul 2023
Topic Review
Tin-iodate rechargeable battery
The tin-iodate battery is a rechargeable battery for large scale energy storage.
  • 2.0K
  • 04 Jan 2022
Topic Review
A Labile Metallo-Porphyrin as Tool to Control J-Aggregates Chiroptical Properties
The zinc(II) metal derivative of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS4) is quite labile and readily demetallates under acidic conditions, affording the parent diacid porphyrin in a monomeric form. The rate of this process is first order on [ZnTPPS4] and second order on [H+], allowing a precise control of the monomer release in solution. Under high ionic strength, this latter species is able to self-assemble into J-aggregates, whose kinetics of growth are largely modulated by pH. The aggregation kinetics have been treated according to a well-established model, in which the formation of an initial nucleus is the rate determining step preceding the autocatalytic growth of the whole assembly. The extinction spectra of the aggregates suggest the occurrence of a dipolar coupling mechanism very similar to that operating in metal nanoparticles. Spontaneous symmetry breaking takes place in these aggregates as evidenced by unusual circular dichroism spectra. The intensity and sign of the effect is controlled by the aggregation rate and therefore can be tuned through a proper choice of initial conditions.
  • 2.0K
  • 15 Jul 2020
Topic Review Video
Physicochemical Processes Leading to Plasma-Driven Solution Electrolysis
A new type of electrolysis, initially known as the contact glow-discharge electrolysis (CGDE) and, more recently, as the plasma-driven solution electrolysis (PDSE), has attracted attention as an alternative method of hydrogen production. PDSE is a nontypical electrochemical process in which electric plasma is formed in the glow discharges excited by the direct or pulsed current in a gas–vapor envelope in the vicinity of the discharge electrode immersed in the electrolytic solution. The yield of chemicals in PDSE (i.e., the ratio of the moles of the product formed to the moles of electrons consumed in a chemical reaction) is several times higher than the Faradaic production of chemicals (predicted by Faraday’s law). In PDSE, new chemical compounds can also be synthesized, which does not happen using Faradaic electrolysis.
  • 2.0K
  • 31 Oct 2022
Topic Review
Corrosion Inhibition of Metal Surfaces Mediated by 1,2,3-Triazoles
Corrosion is generally viewed as the destructive consequence of chemical reaction between a metal or metal alloy and its environment that contains corrosive agents. Compared to inorganic corrosion inhibitors, the organic ones are less toxic, can be also used at low concentrations, and have a better film-forming ability. The adsorption properties of organic corrosion inhibitors are primarily linked to the presence of both π-electrons from aromatic rings and heteroatoms in the molecular structures. Indeed, organic compounds containing nitrogen, phosphorus, sulfur, and oxygen atoms have been extensively investigated as corrosion inhibitors of metals and their alloys in acidic environments. In this respect, triazole derivatives are the most used nitrogen-containing organic inhibitors, in particular the family of 1,2,3-triazoles prepared under click chemistry regime by the prolific copper-catalyzed azide cycloaddition reactions. 
  • 1.9K
  • 10 Feb 2022
Topic Review
Nitrogenase
Nitrogenase defines the familty of enzymes that catalyze the reduction of N2 (molecular nitrogen) to NH3 (ammonia). It is the only enzyme family which can realize this process of nitrogen fization. 
  • 1.9K
  • 19 Feb 2021
Topic Review
Mesoporous Silica Nanoparticles
Mesoporous silica nanoparticles (MSNs) have been widely employed as drug carriers owing to their exquisite physico-chemical properties. Mesoporous material Solid and porous material, with natural or synthetic character, with an average pore size between microporous (less than 2 nm) and macroporous (more than 50 nm). The pore structure can be ordered or not and provides an extremely high surface area in a relatively small amount of material According to IUPAC notation, the mesoporous category is midway between the pore sizes that define microporous materials, up to 2 nm, and macroporous, pore diameters greater than 50 nm. They have a large number of applications in the fields of catalysis, molecular separation, drug release or chemical sensors among others, as a result of the network of porous cavities in their internal structure. - Examples: ordered mesoporous silica materials, carbon molecular sieves, porous organic / inorganic hybrid materials and porous metal oxides.
  • 1.9K
  • 13 Jan 2021
Topic Review
Geant4-DNA Modeling of Water Radiolysis
In this work, we use the next sub-volume method (NSM) to investigate the possibility of using the compartment-based (“on-lattice”) model to simulate water radiolysis.
  • 1.9K
  • 24 Jun 2021
Topic Review
Steady State
In chemistry, a steady state is a situation in which all state variables are constant in spite of ongoing processes that strive to change them. For an entire system to be at steady state, i.e. for all state variables of a system to be constant, there must be a flow through the system (compare mass balance). A simple example of such a system is the case of a bathtub with the tap running but with the drain unplugged: after a certain time, the water flows in and out at the same rate, so the water level (the state variable Volume) stabilizes and the system is in a steady state. The steady state concept is different from chemical equilibrium. Although both may create a situation where a concentration does not change, in a system at chemical equilibrium, the net reaction rate is zero (products transform into reactants at the same rate as reactants transform into products), while no such limitation exists in the steady state concept. Indeed, there does not have to be a reaction at all for a steady state to develop. The term steady state is also used to describe a situation where some, but not all, of the state variables of a system are constant. For such a steady state to develop, the system does not have to be a flow system. Therefore, such a steady state can develop in a closed system where a series of chemical reactions take place. Literature in chemical kinetics usually refers to this case, calling it steady state approximation. In simple systems the steady state is approached by state variables gradually decreasing or increasing until they reach their steady state value. In more complex systems state variable might fluctuate around the theoretical steady state either forever (a limit cycle) or gradually coming closer and closer. It theoretically takes an infinite time to reach steady state, just as it takes an infinite time to reach chemical equilibrium. Both concepts are, however, frequently used approximations because of the substantial mathematical simplifications these concepts offer. Whether or not these concepts can be used depends on the error the underlying assumptions introduce. So, even though a steady state, from a theoretical point of view, requires constant drivers (e.g. constant inflow rate and constant concentrations in the inflow), the error introduced by assuming steady state for a system with non-constant drivers may be negligible if the steady state is approached fast enough (relatively speaking).
  • 1.9K
  • 14 Oct 2022
Topic Review
Applications of g-C3N4-Based Photocatalysts
The assembly of g-C3N4 with metal oxides is an effective strategy which can not only improve electron–hole separation efficiency by forming a polymer–inorganic heterojunction, but also compensate for the redox capabilities of g-C3N4 owing to the varied oxidation states of metal ions, enhancing its photocatalytic performance. Applications of g-C3N4-based materials in photocatalysis are discussed, including water splitting to generate H2 and O2, the degradation of pollutants, CO2 reduction and bacterial disinfection.
  • 1.8K
  • 29 Nov 2022
Topic Review
Logic Gates and Molecular Logic Gates
Logic gates are devices used to perform binary arithmetic and logical operations and thus constitute the basis of modern computers. They perform Boolean logic operations on one or more inputs to produce an output. Molecular switches convert input stimulations into output signals. Therefore, the principles of binary logic can be applied to the signal transduction operated by molecular switches. The presence of various ions, neutral species, pH, temperature, and viscosity, among many others, result in color or emission changes due to the complex interplay of many excited state processes and environmental parameters. In this entry, basic logic gates are defined, and their types are given, while examples of molecular logic gates are also presented.
  • 1.8K
  • 29 Mar 2024
Topic Review
The Design of Ni-Based Single Crystal Superalloys
The most important performance characteristics of heat-resistant alloys (HRAs) are creep and fatigue resistance, which are very complex functions of chemical composition and microstructure. The microstructure of metal HRAs, among which the first place is occupied by Ni-based alloys, usually consists of two main phases: a solid solution based on the main element containing alloying elements (matrix), and a strengthening phase, which is usually used as intermetallides, carbides and silicides.
  • 1.8K
  • 17 Jan 2022
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