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Topic Review
Crossover Experiment
In chemistry, a crossover experiment is a method used to study the mechanism of a chemical reaction. In a crossover experiment, two similar but distinguishable reactants simultaneously undergo a reaction as part of the same reaction mixture. The products formed will either correspond directly to one of the two reactants (non-crossover products) or will include components of both reactants (crossover products). The aim of a crossover experiment is to determine whether or not a reaction process involves a stage where the components of each reactant have an opportunity to exchange with each other. The results of crossover experiments are often straightforward to analyze, making them one of the most useful and most frequently applied methods of mechanistic study. In organic chemistry, crossover experiments are most often used to distinguish between intramolecular and intermolecular reactions. Inorganic and organometallic chemists rely heavily on crossover experiments, and in particular isotopic labeling experiments, for support or contradiction of proposed mechanisms. When the mechanism being investigated is more complicated than an intra- or intermolecular substitution or rearrangement, crossover experiment design can itself become a challenging question. A well-designed crossover experiment can lead to conclusions about a mechanism that would otherwise be impossible to make. Many mechanistic studies include both crossover experiments and measurements of rate and kinetic isotope effects.
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  • 28 Oct 2022
Topic Review
Gold-Nanoparticle Hybrid Nanostructures for Multimodal Cancer Therapy
With the urgent need for bio-nanomaterials to improve the currently available cancer treatments, gold nanoparticle (GNP) hybrid nanostructures are rapidly rising as promising multimodal candidates for cancer therapy. Gold nanoparticles (GNPs) have been hybridized with several nanocarriers, including liposomes and polymers, to achieve chemotherapy, photothermal therapy, radiotherapy, and imaging using a single composite. The GNP nanohybrids used for targeted chemotherapy can be designed to respond to external stimuli such as heat or internal stimuli such as intratumoral pH. 
  • 444
  • 28 Oct 2022
Topic Review
The Tetrahydrofuran Motif in Marine Lipids and Terpenes
Heterocycles are particularly common moieties within marine natural products. Specifically, tetrahydrofuranyl rings are present in a variety of compounds which present complex structures and interesting biological activities. Focusing on terpenoids, a high number of tetrahydrofuran-containing metabolites have been isolated. They show promising biological activities, making them potential leads for novel antibiotics, antikinetoplastid drugs, amoebicidal substances, or anticancer drugs. Thus, they have attracted the attention of the synthetics community and numerous approaches to their total syntheses have appeared.
  • 650
  • 28 Oct 2022
Topic Review
Cracking
In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or long-chain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carbon-carbon bonds in the precursors. The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. Cracking is the breakdown of a large alkane into smaller, more useful alkenes. Simply put, hydrocarbon cracking is the process of breaking a long chain of hydrocarbons into short ones. This process requires high temperatures. More loosely, outside the field of petroleum chemistry, the term "cracking" is used to describe any type of splitting of molecules under the influence of heat, catalysts and solvents, such as in processes of destructive distillation or pyrolysis. Fluid catalytic cracking produces a high yield of petrol and LPG, while hydrocracking is a major source of jet fuel, diesel fuel, naphtha, and again yields LPG.
  • 908
  • 27 Oct 2022
Topic Review
IMP321
IMP321 is a large molecule cancer drug being developed by the clinical stage biotechnology company Prima BioMed (Nasdaq: IMMP). The drug is Prima's lead compound. IMP321 (INN name: eftilagimod alpha) is soluble version of the immune checkpoint molecule LAG3, used to increase an immune response to tumours. The drug is administered by subcutaneous injection. IMP321 has two intended clinical settings, 'low dose' (for example 250 µg) as adjuvant to cancer vaccines and 'high dose' (such as 12 injections of 6 mg each) as first-line 'chemo-immunotherapy', that is, combined with standard chemotherapy. IMP321 has been in Phase II clinical testing. The product has been shown to be non-immunogenic, that is, no anti-IMP321 antibodies have been detected in clinical trials. Currently the main indication for the drug is metastatic breast cancer.
  • 532
  • 27 Oct 2022
Topic Review
Pharmaceutical and Microplastic Pollution in Water
Pharmaceuticals (PhACs) and microplastics (MPs) are emerging pollutants that pose serious environmental risks. PhACs have been found in low concentrations in a variety of environmental samples, including sewage treatment plant effluents, surface water, seawater, and groundwater, in a number of countries.
  • 599
  • 27 Oct 2022
Topic Review
Iguvine Tablets
The Iguvine Tablets, also known as the Eugubian Tablets or Eugubine Tables, are a series of seven bronze tablets from ancient Iguvium (modern Gubbio), Italy, written in the ancient Italic language Umbrian. The earliest tablets, written in the native Umbrian alphabet, were probably produced in the 3rd century BC, and the latest, written in the Latin alphabet, from the 1st century BC. The tablets contain religious inscriptions that memorialize the acts and rites of the Atiedian Brethren, a group of 12 priests of Jupiter with important municipal functions at Iguvium. The religious structure present in the tablets resembles that of the early stage of Roman religion, reflecting the Roman archaic triad and the group of gods more strictly related to Jupiter. Discovered in a farmer's field near Scheggia in the year 1444, they are currently housed in the Civic Museum of the Palazzo dei Consoli in Gubbio. The tablets are by far the longest and most important document of any of the Osco-Umbrian group of languages, which are closely related to Latin. The tablets shed light on the grammar of this ancient dead language, and also on the religious practices of the ancient peoples of Italy, including the archaic religion of the Romans. Parts of tablets VI and VII appear to be written in an accentual metre, similar to the Saturnian metre that is encountered in the earliest Latin poetry. The complete text, together with a translation into Latin, was published in London in 1863 by Francis Newman and 1931 in a book by Albrecht von Blumenthal. They were translated into English and published by James W. Poultney in 1959. Although the general meaning of the tablets is clear, there are still many obscure and debated points and issues. The main difficulty in understanding the text is the insufficient knowledge of the Umbrian vocabulary. These are the only documents of full details of sacred rituals from the ancient religions of Europe which have come down to us in an almost complete state. Moreover, their content deals with the rituals (sacrifices and prayers) addressed to the highest gods of the local community and to some extent may reflect the common religious beliefs and practices of the Italic peoples. Consequently, a great number of scholars have devoted their efforts to reading and deciphering them since their discovery. The modern Festival of Ceri, celebrated every year in Gubbio on May 15 in honor of Bishop Ubald or Ubaldo of Gubbio (1084–1160), shares certain features with the rites described in the text and so may be a survival of that ancient pre-Christian custom. It is also celebrated in Jessup, Pennsylvania, a town with a large number of immigrants from the Gubbio area, as Saint Ubaldo Day.
  • 1.1K
  • 27 Oct 2022
Topic Review
Tetravalence
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules.
  • 872
  • 27 Oct 2022
Topic Review
Margatoxin
Margatoxin (MgTX) is a peptide that selectively inhibits Kv1.3 voltage-dependent potassium channels. It is found in the venom of Centruroides margaritatus, also known as the Central American Bark Scorpion. Margatoxin was first discovered in 1993. It was purified from scorpion venom and its amino acid sequence was determined.
  • 271
  • 27 Oct 2022
Topic Review
Nanotechnology in Cosmetics
Nanomaterials are materials with a size ranging from 1 to 100 nm in at least one dimension. At the nanoscale, material properties become different. These unique properties can be exploited for a variety of applications, including the use of nanoparticles in skincare and cosmetics products. Cosmeceuticals is one of the fastest growing industries in terms of personal care, accompanied by an increase in nanocosmeceuticals research and applications.
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