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Topic Review
Dynamic Nuclear Polarisation
Dynamic nuclear polarization (DNP) results from transferring spin polarization from electrons to nuclei, thereby aligning the nuclear spins to the extent that electron spins are aligned. Note that the alignment of electron spins at a given magnetic field and temperature is described by the Boltzmann distribution under the thermal equilibrium. It is also possible that those electrons are aligned to a higher degree of order by other preparations of electron spin order such as: chemical reactions (leading to Chemical-Induced DNP, CIDNP), optical pumping and spin injection. DNP is considered one of several techniques for hyperpolarization. DNP can also be induced using unpaired electrons produced by radiation damage in solids. When electron spin polarization deviates from its thermal equilibrium value, polarization transfers between electrons and nuclei can occur spontaneously through electron-nuclear cross relaxation and/or spin-state mixing among electrons and nuclei. For example, the polarization transfer is spontaneous after a homolysis chemical reaction. On the other hand, when the electron spin system is in a thermal equilibrium, the polarization transfer requires continuous microwave irradiation at a frequency close to the corresponding electron paramagnetic resonance (EPR) frequency. In particular, mechanisms for the microwave-driven DNP processes are categorized into the Overhauser effect (OE), the solid-effect (SE), the cross-effect (CE) and thermal-mixing (TM). The first DNP experiments were performed in the early 1950s at low magnetic fields but until recently the technique was of limited applicability for high-frequency, high-field NMR spectroscopy, because of the lack of microwave (or terahertz) sources operating at the appropriate frequency. Today such sources are available as turn-key instruments, making DNP a valuable and indispensable method especially in the field of structure determination by high-resolution solid-state NMR spectroscopy.
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Topic Review
Diamond DA42
The Diamond DA42 Twin Star is a four seat, twin engine, propeller-driven airplane developed and manufactured by Austrian company Diamond Aircraft Industries. It was Diamond's first twin engine design, as well as the first new European twin-engine aircraft in its category to be developed in over 25 years. In 2004, the DA42 became the first diesel-powered fixed-wing aircraft to perform a non-stop crossing of the North Atlantic. By 2012, the DA42 had become a key revenue generator for the company, having gained popularity with government and military operators in addition to the civil market that had suffered as a result of the Great Recession. Government customers have typically employed the type in the aerial surveillance role, which contributed towards the development of the Aeronautics Defense Dominator, a medium-altitude long-endurance (MALE) unmanned aerial vehicle (UAV), which had been derived from the DA42.
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  • 21 Nov 2022
Topic Review
List of Proton Launches (2010–Present)
This is a list of launches made by the Proton-M rocket between 2010 and 2019. All launches were conducted from the Baikonur Cosmodrome.
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Biography
Ilaria Capua
Ilaria Capua (Rome, April 21, 1966) is a virologist and former Italian politician, best known for her research on influenza viruses, particularly avian influenza, and her efforts promoting open access to genetic information on emerging viruses as part of pre-pandemic preparedness efforts. Dr. Capua is currently a full professor with Institute of Food and Agricultural Science (IFAS), and has a j
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  • 21 Nov 2022
Topic Review
Backbone Chain
In polymer science, the backbone chain of a polymer is the longest series of covalently bonded atoms that together create the continuous chain of the molecule. This science is subdivided into the study of organic polymers, which consist of a carbon backbone, and inorganic polymers which have backbones containing only main group elements. In biochemistry, organic backbone chains make up the primary structure of macromolecules. The backbones of these biological macromolecules consist of central chains of covalently bonded atoms. The characteristics and order of the monomer residues in the backbone make a map for the complex structure of biological polymers (see Biomolecular structure). The backbone is, therefore, directly related to biological molecules’ function. The macromolecules within the body can be divided into four main subcategories, each of which are involved in very different and important biological processes: proteins, carbohydrates, lipids, and nucleic acids. Each of these molecules has a different backbone and consists of different monomers each with distinctive residues and functionalities. This is the driving factor of their different structures and functions in the body. Although lipids have a "backbone," they are not true biological polymers as their backbone is a three carbon molecule, glycerol, with longer substituent "side chains." For this reason, only proteins, carbohydrates, and nucleic acids should be considered as biological macromolecules with polymeric backbones.
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Biography
Aleksandr Markevich
Oleksandr Prokopovych Markevych (Ukrainian: Олександр Прокопович Маркевич), in English more often Aleksandr Prokofyevich Markevich (Russian: Александр Прокофьевич Маркевич) (19 March 1905 – 23 April 1999) was a Ukrainian zoologist, and a prolific helminthologist and copepodologist. He was professor and an Academician of the National Academ
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Biography
Edith Balfour Lyttelton
Dame Edith Sophy Lyttelton GBE JP (née Balfour; 4 April 1865 – 2 September 1948) was a British novelist, playwright, World War I-era activist and spiritualist.[1] Dame Edith was born in Saint Petersburg, the eldest daughter of Archibald Balfour, a London businessman and merchant in the Russian Empire, and Sophia "Sophy" Weguelin, daughter of MP Thomas Matthias Weguelin. Edith was educated
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Biography
Jason Halbert
Jason Halbert (born June 3, 1974) is an American producer, music director,[1][2] musician, engineer and songwriter.[3] He has been Kelly Clarkson's music director since 2003, shortly after her American Idol win.[2][4] He has also served as music director for Nick Carter (musician), Clay Aiken, Justin Guarini[5] in addition to touring as keyboardist for Paulina Rubio and Reba McEntire.[6][7][8][9
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Biography
David Haussler
David Haussler (born 1953) is an American bioinformatician known for his work leading the team that assembled the first human genome sequence in the race to complete the Human Genome Project and subsequently for comparative genome analysis that deepens understanding the molecular function and evolution of the genome.[1][2] He is a Howard Hughes Medical Institute Investigator, professor of biomol
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  • 21 Nov 2022
Topic Review
Salt and Cardiovascular Disease
Salt consumption has been extensively studied for its role in human physiology and impact on human health. Chronic, high intake of dietary salt consumption is associated with hypertension and cardiovascular disease, in addition to other adverse health outcomes. Major health and scientific organizations, such as the World Health Organization, US Centers for Disease Control and Prevention, and American Heart Association, have established high salt consumption as a major risk factor for cardiovascular diseases and stroke. Common edible salt is composed of sodium chloride.
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