Search results for " coi"

Design and evaluation of a 32-channel phased-array coil for lung imaging with hyperpolarized 3-helium

2010

Imaging with hyperpolarized 3-helium is becoming an increasingly important technique for MRI diagnostics of the lung but is hampered by long breath holds (>20 sec), which are not always applicable in patients with severe lung disease like chronic obstructive pulmonary disease (COPD) or α-1-anti-trypsin deficiency. Additionally, oxygen-induced depolarization decay during the long breath holds complicates interpretation of functional data such as apparent diffusion coefficients. To address these issues, we describe and validate a 1.5-T, 32-channel array coil for accelerated 3He lung imaging and demonstrate its ability to speed up imaging 3He. A signal-to-noise ratio increase of up to a factor…

COVID-19 and its linguistic variants from Miss Rona to Boomer Remover

2022

The COVID-19 pandemic has had an enormous impact on everyday language and has led to unprecedented linguistic innovation and lexical explosion, ranging from the medicalisation of everyday language to the creation of new word formations that have defined new situations and overcome the fear of an unknown disease. In this paper, after briefly introducing the main linguistic features of English neologisms created to define changes in life style during the pandemic, a survey of the main English monikers coined to rename COVID-19 will be given taking into account the most recent studies on the subject.

A new record and molecular characterization of the Green Turtle Chelonia mydas (Testudines, Cheloniidae) in Sicilian coastal waters

2017

A juvenile specimen of the Green Turtle, Chelonia mydas, was recovered in Sicilian coastal waters close to Avola (Syracuse province, south-eastern Sicily, Italy). Before being released, the specimen was measured and inspected for the presence of ingested hooks or other possible harms to its health. A fragment of the mtDNA marker COI was amplified and sequenced in order to provide the first molecular data for the species from the central Mediterranean area. The possible influence of climate change on the occurrence of this thermophilic species in the central Mediterranean area is briefly discussed.

Neue vorstellungen über statistische fadenknäuel

1967

In Losung liegen synthetische Fadenmolekule im allgemeinen als Knauel vor. Diese Aussage stellt jedoch noch keine sehr genaue Information uber die Gestalt eines Fadenmolekuls dar. Hierzu bedarf es einer Systematik der verschiedenen Knaueltypen. Die Aufstellung einer solchen Systematik ist ein rein geometrisches Problem. Zunachst wird zwischen irrflugartigen und nicht-irrflugartigen Knaueln unterschieden. Ein irrflugartiges Knauel ist ein solches, bei dem die relative Orientierung zweier Fadenelemente zueinander zufallig ist, wenn die Entfernung zwischen den beiden Fadenelementen – langs des Fadens gemessen – hinreichend gros ist. Beispiele fur irrflugartige Knauel sind das KUHNsche Segmentm…

A Classical Synthesis of the Collagen-like Peptides with the Sequence Z(GlyProPro)nOBut and their characterization with circular dichroism and ultrac…

1975

Oligopeptides with the sequence Z(GlyProPro)nOBut (n = 3–7) were synthesized along a clasical pathway. Generally long fragments were condensed in order to allow an easy separation of the products from the reactants. It is established by molecular weight determination and measurements of circular dichroism that the peptides form the collagen-like triple helix in methanol and that they assume the random coil conformation in dilute acetic acid. The circular dichroism spectra agree reasonably well with the corresponding spectra for (ProProGly)10 which was obtained by solid phase synthesis in another laboratory.

Titration of poly(dA-dT) · poly(dA-dT) in solution at variable NaCl concentration

2004

CD and uv absorption data showed that high molecular weight poly(dA-dT) . poly(dA-dT), at 298 K, undergoes an acid-induced transition from B-double helix to random coil in NaCl solutions of different concentrations, ranging from 0.005 to 0.600M. Similarly, titration of the polynucleotide with a strong base causes duplex-to-single strands transition. The base- and acid-induced transitions were both reversible by back-titration (with an acid or, respectively, with a base): the apparent pKa were the same in both directions. However, the number of protons per titratable site (adenine N1) required to reach half-denaturation was in great excess over the stoichiometric value; to a much larger exte…

1981

The interaction of poly(L-glutamic acid) with 3,6-dioxaoctamethylenediamine was studied by circular dichroism spectroscopy under different conditions. In aqueous solution at pH 5,6 and in aqueous 1,4-dioxane (30–50 vol.-%) at pH 7,3 the conformation of poly(L-glutamic acid) was completely changed from α-helical to random coil in the presence of an excess of the diamine.

Discrete and Conservative Factorizations in Fib(B)

2021

AbstractWe focus on the transfer of some known orthogonal factorization systems from$$\mathsf {Cat}$$Catto the 2-category$${\mathsf {Fib}}(B)$$Fib(B)of fibrations over a fixed base categoryB: the internal version of thecomprehensive factorization, and the factorization systems given by (sequence of coidentifiers, discrete morphism) and (sequence of coinverters, conservative morphism) respectively. For the class of fibrewise opfibrations in$${\mathsf {Fib}}(B)$$Fib(B), the construction of the latter two simplify to a single coidentifier (respectively coinverter) followed by an internal discrete opfibration (resp. fibrewise opfibration in groupoids). We show how these results follow from thei…

On the Coincidence of the Feedback Nash and Stackelberg Equilibria in Economic Applications of Differential Games

2002

In this paper the scope of the applicability of the Stackelberg equilibrium concept in differential games is investigated. Firstly, conditions for obtaining the coincidence between the Stackelberg and Nash equilibria are defined in terms of the instantaneous pay-off function and the state equation of the game. Secondly, it is showed that for a class of differential games with state-interdependence both equilibria are identical independently of the player being the leader of the game. A survey of different economic models shows that this coincidence is going to occur for a good number of economic applications of differential games. This result appears because of the continuous-time setting i…

The use of slightly asymmetrical windings for rotating electrical machines

2018

Historically, asymmetrical windings in electrical machines have been rarely used and only for specified needs, because the adoption of symmetrical configurations has always been considered the only solution during the design stage of electrical machines. The aim of this work is to demonstrate with several examples that the use of slightly asymmetrical windings can be a reasonable choice and, in certain cases, a favorable option during the machine design stage, allowing the possibility of selecting a wider range of slot/pole number combinations, without affecting the performances of the machines. More in detail, an interior permanent magnet synchronous machine equipped with a symmetrical 3-p…