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Biography
Iris Runge
Iris Anna Runge (1 June 1888 – 27 January 1966) was a German applied mathematician and physicist. Iris Runge was the eldest of six children of mathematician Carl Runge. She started studying physics, mathematics, and geography at the University of Göttingen in 1907, with the aim of becoming a teacher. At that time, she only attended the lectures, since women were not allowed to formally stu
  • 389
  • 29 Dec 2022
Topic Review
Ionizing Radiation
The development of protective agents against harmful radiations has been a subject of investigation for decades. However, effective (ideal) radioprotectors and radiomitigators remain an unsolved problem. Because ionizing radiation-induced cellular damage is primarily attributed to free radicals, radical scavengers are promising as potential radioprotectors. Early development of such agents focused on thiol synthetic compounds, e.g., amifostine (2-(3-aminopropylamino) ethylsulfanylphosphonic acid), approved as a radioprotector by the Food and Drug Administration (FDA, USA) but for limited clinical indications and not for nonclinical uses. To date, no new chemical entity has been approved by the FDA as a radiation countermeasure for acute radiation syndrome (ARS). All FDA-approved radiation countermeasures (filgrastim, a recombinant DNA form of the naturally occurring granulocyte colony-stimulating factor, G-CSF; pegfilgrastim, a PEGylated form of the recombinant human G-CSF; sargramostim, a recombinant granulocyte macrophage colony-stimulating factor, GM-CSF) are classified as radiomitigators. No radioprotector that can be administered prior to exposure has been approved for ARS. This differentiates radioprotectors (reduce direct damage caused by radiation) and radiomitigators (minimize toxicity even after radiation has been delivered). Molecules under development with the aim of reaching clinical practice and other nonclinical applications are discussed. Assays to evaluate the biological effects of ionizing radiations are also analyzed. Ionizing radiation is the energy released by atoms in the form of electromagnetic waves (e.g., X or gamma rays) or particle radiation (alpha, beta, electrons, protons, neutrons, mesons, prions, and heavy ions) with sufficient energy to ionize atoms or molecules.
  • 1.9K
  • 23 Feb 2022
Topic Review
Ionizing Irradiations in Food Industry
The ionizing radiations are particles or waves containing enough energy to ionize the matter when coming in contact. Their mode of action in living cells involves either the direct destruction of nucleic acid or by creating free radicals that can attack the cellular components. This cellular destruction and inactivation can be used to reduce the microbial burden in food items to increase the shelf life and safety of food, meanwhile maintaining the quality of the product. Although this technology is accepted by more than 60 countries, some consumers are reluctant to buy such products thinking that radiations might have modified their food which can also induce changes in their body after consumption. The proper scientific communication regarding the safety of ionization irradiations can change consumer behavior, and it requires the collaboration of all stakeholders in the food production chain. 
  • 2.1K
  • 05 Nov 2020
Topic Review
Ionising Radiation Sensors
Ionising radiation affects electronic circuits as well as living beings and has been a major concern for various critical applications such as healthcare, mining, avionics, nuclear, high-energy physics, and space applications. Radiation sensors are essential tools to estimate, measure and characterise radiation related information to assess the system performance and subsequently look for corrective measures. 
  • 891
  • 23 Sep 2021
Topic Review
Ionic and Excited Species
Experimental and theoretical studies of either characterization and reactivity of ionic and excited species with atoms, molecules, and radicals of interest in the chemistry of plasmas and energy production. Single and ionized species with single or multiple charge (H+, He+, H3+, HCO+, H3O+, He22+, CO22+, etc.), excited atoms and molecules (e.g. O(1D), N(2D), H*(2s2S1/2), He*(21,3S0,1), N2*(A3Σu+), etc.) play a crucial role in various important chemical systems such as flames (i.e. chemi-ionizations), natural plasmas (i.e. planetary ionospheres, comet tails and interstellar clouds), and biological environments (e.g. damaged biological tissues via the interaction between ionizing radiation and living cells). Such processes are very interesting from a fundamental point of view in Physical Chemistry and attracted the attention of a wide scientific community, since many applications to important fields: radiation chemistry, plasma physics and chemistry, combustion processes, development of laser sources. In particular, the conversion of waste carbon dioxide via assisted plasma technology gained recently increasing interest due to the possibility of obtaining value-added products, like gaseous or liquid fuels. Such characteristics make this an encouraging strategy for the storage of electrical energy from renewable sources into chemical energy in a circular economy scheme.
  • 1.4K
  • 01 Nov 2020
Topic Review
Ion-selective Electrodes
An Ion-selective electrode (ISE) is a transducer (sensor) which converts the activity of a specific ion dissolved in a solution into an electrical potential which can be measured by a voltmeter or pH meter. The voltage is theoretically dependent on the logarithm of the ionic activity, according to the Nernst equation. The sensing part of the electrode is usually made as an ion-specific membrane, along with a reference electrode. Ion-selective electrodes are used in biochemical and biophysical research, where measurements of ionic concentration in an aqueous solution are required, usually on a real time basis.
  • 1.4K
  • 10 Oct 2022
Topic Review
Ion-Mobility Spectrometry
Ion mobility spectrometry (IMS) is an analytical technique used to separate and identify ionized molecules in the gas phase based on their mobility in a carrier buffer gas. Though heavily employed for military or security purposes, such as detecting drugs and explosives, the technique also has many laboratory analytical applications, including the analysis of both small and large biomolecules. IMS instruments are extremely sensitive stand-alone devices, but are often coupled with mass spectrometry, gas chromatography or high-performance liquid chromatography in order to achieve a multi-dimensional separation. They come in various sizes, ranging from a few millimeters to several meters depending on the specific application, and are capable of operating under a broad range of conditions. IMS instruments such as microscale high-field asymmetric-waveform ion-mobility spectrometry can be palm-portable for use in a range of applications including volatile organic compound (VOC) monitoring, biological sample analysis, medical diagnosis and food quality monitoring. Systems operated at higher pressure (i.e. atmospheric conditions, 1 atm or 1013 hPa) are often accompanied by elevated temperature (above 100 °C), while lower pressure systems (1-20 hPa) do not require heating.
  • 492
  • 30 Nov 2022
Topic Review
Ion-Exchange
According to Encyclopedia Britannica, ion-exchange process can be defined as “any class of chemical reactions between two substances (each consisting of positively and negatively charged species called ions) that involves an exchange of one or more ionic components”. This is the case, for example, of a multi-component oxide glass immersed – at a given temperature – in a mixture of molten salts containing metal ions (typically nitrates such as silver nitrate AgNO3, potassium nitrate KNO3, copper nitrate Cu(NO3)2, sodium nitrate NaNO3, etc.). Because of the high temperature at which the process occurs and concentration gradient established in proximity of the interface between glass and molten salt, sodium ions Na+ present within the compound glass migrate in the solution and are replaced by cations originally contained in the salt melt (e.g., Ag+, K+, Cu2+, etc.). Due to the different size and polarizability of the ions participating in the process, the glass modifies its network locally in the exchanged regions, with particular reference to its density and, therefore, to its refractive index. This paves the way for the production of graded-index optical components and waveguides, for passive and active integrated optical devices. Furthermore, the K+ – Na+ exchange is the basis for the chemical strengthening of the glass, which allows to obtain mechanically resistant glasses in increasingly thinner thicknesses for applications in smartphone technology and flexible photonics. Finally, the possibility of inducing the formation of noble metal nanoparticles in an ion-exchanged glass following particular thermal post-process techniques allows the realization of new low-cost optical platforms for sensing and photovoltaic applications.
  • 857
  • 31 May 2021
Topic Review
Ion Channel and Bioinformatics
Ion channels are linked to important cellular processes. The use of artificial intelligence (AI) in bioinformatics and computational molecular biology research has been growing fast over the last two decades. Bioinformatics methods attempt to model known biological structures and predict unknown ones. Versatile bioinformatics techniques are capable of storing the information processed in various biological and biophysical studies in the created databank, and calling and utilizing the information from the databank in pinpointing crucial molecular processes of an individual system or collective ones. The techniques thus help establish scientific links between various mechanisms and processes and produce concluding evidence that is otherwise often unattainable using conventional theoretical and experimental techniques. Besides, computational techniques are popularly found to model the biomolecular complexes in silico studies to mainly address their statics, dynamics, and energetics in an artificially constructed, yet mimicking the biological systems’ environment.
  • 572
  • 08 Oct 2021
Topic Review
Introduction to the Mathematics of General Relativity
The mathematics of general relativity is complex. In Newton's theories of motion, an object's length and the rate at which time passes remain constant while the object accelerates, meaning that many problems in Newtonian mechanics may be solved by algebra alone. In relativity, however, an object's length and the rate at which time passes both change appreciably as the object's speed approaches the speed of light, meaning that more variables and more complicated mathematics are required to calculate the object's motion. As a result, relativity requires the use of concepts such as vectors, tensors, pseudotensors and curvilinear coordinates. For an introduction based on the example of particles following circular orbits about a large mass, nonrelativistic and relativistic treatments are given in, respectively, Newtonian motivations for general relativity and Theoretical motivation for general relativity.
  • 787
  • 01 Dec 2022
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