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PubMed1996

[Birth representation with reference to the magical coriander prescription of Codex Vindobonensis 93, fol. 102r, of the Austrian National Library].

One of the most impressive manuscript illustrations of the medieval history of midwifery is found in the Codex Vindobonensis 93, fol. 102r (a manuscript from the early 13th century), illustrating a magic prescription of herba coriandrum to accelerate childbirth. The composition of the omnibus manuscript is critically delineated in its historical context. The illustration, being isolated without any obstetrical teaching text, is judged as part of the ancient tradition of teaching by images which has no parallel north of the Alps. The different image traditions are reflected in the historical use and illustration of the midwifery chair, which can be traced back only to the beginning of the 16th century in Central Europe and on the British Isles. The importance of the magic prescription is shown by comparison within the same and other collections used in the Middle Ages and classified in the context of further traditions of magic in midwifery.

Europe↗

PubMed2003

Magical ideation modulates spatial behavior.

Previous research has found that animals as well as persons with psychotic disorders preferentially orient away from the cerebral hemisphere with the more active dopamine system. This study investigated the modulation of spatial behavior by a mode of thinking reminiscent of the positive symptoms of psychosis. In a non-treatment-seeking sample of healthy volunteers (20 women and 16 men), the authors assessed the lateral biases in turning and veering behavior and in line bisection as a function of their magical ideation, that is, a mild form of schizotypy. Across tasks, pronounced magical ideation was associated with reduced right-sided orientation preferences. This finding suggests a relative hyperdopaminergia of the right hemisphere as the biological basis of magical ideation.

Adult↗

PubMed2005

Relationship between magical ideation and noctcaelador.

This study explored the relationship between magical ideation and "noctcaelador" (strong interest in, and psychological attachment to, the night sky). 210 university students completed Eckblad and Chapman's 1983 Magical Ideation Scale and Kelly's 2004 Noctcaelador Inventory. Scores on the two scales were significantly positively related and accounted for 14% of the common variance. Based on this operational definition of magical ideation, a strong interest in the night-sky might be associated with uncommon beliefs and reports of unusual perceptual experience. Researchers must clarify and define these concepts to study possible relations.

Adolescent↗

PubMed2000

[X-rays between art and science in The Magic Mountain].

When x-ray, in the early 1900s, was hailed as the new instrument of objective verification and indisputable proof, it signaled the reign of the visual over the other senses of empirical verification, such as sound and touch. The extent of visual evidence was believed to be all- encompassing: x-rays were supposedly a sort of super photography that could prove the existence of immaterial substances, the materiality of things heretofore unseen. Thomas Mann's The Magic Mountain (1924) elaborates on three invisible aspects of the body: the verification of disease (tuberculosis), the visualization of intimate feelings such as love, and the ultimate proof of the spirtual self after death. In all three areas - medical, psychological and metaphysical - the x-ray was thought to be a magical instrument that could render the body (and soul) transparent. The Magic Mountain does not simply reflect these beliefs, but problematizes cultural conceptions inspired by medical-scientific axiomas.

Germany↗

PubMedDate not supplied

[Magical thinking and self development].

Based on a historical survey of the term "magic thinking" structural aspects of primary process and prelogical thinking will be elucidated. Developmental necessities for the emergence of magic interpretations in children of pre-school age are proposed. The thesis will be formulated, that magic interpretations may help the developing self in the management of life-circumstances during a period of cognitive egocentrism: feelings of non-competence may be compensated, and the locus of control may be held in the face of experiences of inferiority.

Child↗

PubMed2002

Dodecahedral clathrate structures and magic numbers in alkali cation microhydration clusters.

Using global geometry optimization based on our specialized version of Genetic Algorithms, we have examined the global and most important local minimum energy structures of water microsolvation clusters of potassium and cesium cations within the common TIP4P/OPLS model. Together with our earlier results on the corresponding sodium case, this work constitutes a first step towards a theoretical elucidation of "magic numbers" of solvating molecules and proposed special structures occurring in these systems. In particular, the actual role of dodecahedral cage structures is examined. Within the present model, they do not occur in sodium microsolvation, in agreement with the absence of the magic number 20 for this system. For potassium and cesium microsolvation, dodecahedral cages do occur but their actual structures are far from ideal and their importance appears to be overrated. We offer simple explanations for structural features and trends, and for magic numbers smaller than 20.

Journal Article↗

PubMed2006

Localized in vivo isotropic-anisotropic correlation 1H NMR spectroscopy using ultraslow magic angle spinning.

In a previous work (1), the susceptibility broadening in the (1)H NMR metabolite spectrum obtained in a live mouse was separated from the isotropic information, which significantly increased the spectral resolution. This was achieved using ultraslow magic angle spinning (MAS) of the animal combined with a modified phase-corrected magic angle turning (PHORMAT) pulse sequence. However, PHORMAT cannot be used for spatially selective spectroscopy. This article introduces a modified sequence called localized magic angle turning (LOCMAT) that makes this possible. Proton LOCMAT spectra were obtained from the liver and heart of a live mouse while the animal was spun at a speed of 4 Hz in a 2 Tesla field. It was found that even in this relatively low field, LOCMAT provided isotropic line widths that were a factor of 4-10 times smaller than those obtained in a stationary animal. Furthermore, the susceptibility broadening of the heart metabolites showed unusual features that are not observed in dead animals. The limitations of LOCMAT and possible ways to improve the technique are discussed. It is concluded that in vivo LOCMAT can significantly enhance the utility of NMR spectroscopy for biomedical research.

Animals↗

PubMed1996

Magic echoes and NMR imaging of solids.

Solid state NMR imaging techniques based on magic echoes are reviewed. The theoretical background of magic echoes in general and their spatial encoding in particular is treated. The magic-echo imaging pulse sequences presently in use are described and discussed. Particular emphasis is devoted to those techniques, which allow the incorporation of spectroscopic or parameter-selective information. The applicability of these methods for the investigation of materials is demonstrated and perspectives for materials science are outlined.

Image Enhancement↗

PubMed2005

NMR in rotating magnetic fields: magic-angle field spinning.

Magic-angle sample spinning is one of the cornerstones in high-resolution NMR of solid and semisolid materials. The technique enhances spectral resolution by averaging away rank 2 anisotropic spin interactions, thereby producing isotropic-like spectra with resolved chemical shifts and scalar couplings. In principle, it should be possible to induce similar effects in a static sample if the direction of the magnetic field is varied (e.g., magic-angle rotation of the B0 field). Here we will review some recent experimental results that show progress toward this goal. Also, we will explore some alternative approaches that may enable the recovery of spectral resolution in cases where the field is rotating off the magic angle. Such a possibility could help mitigate the technical problems that render difficult the practical implementation of this method at moderately strong magnetic fields.

Anisotropy↗

PubMed2002

Towards high-resolution 1H-NMR in biological membranes: magic angle spinning of bicelles.

Proton line narrowing in biomembranes spun at the magic angle, for spinning speeds greater than 7 kHz, was investigated in two ways: increasing the field strength from 200 to 800 MHz and changing the membrane fluidity. The resolution that one can obtain on natural lipid membranes under the form of liposomes is 0.019 ppm at 800 MHz. On the other hand, spinning bicelles (disk-like model membranes made of synthetic long and short chain lipids) at the magic angle decreases the line width by an additional factor of 3 provided the bicelle is subjected to large orientational disorder. This leads to proton line widths of the order of 6 Hz at 500 MHz. The conjunction of high field, magic angle spinning and use of bicelle membranes should prove to be useful to solve membrane protein structure in a membrane environment.

Animals↗

PubMed1981

Magic angle spinning carbon-13 NMR of tobacco mosaic virus. An application of the high-resolution solid-state NMR spectroscopy to very large biological systems.

Magic angle spinning 13C NMR was used to study tobacco mosaic virus (TMV) in solution. Well-resolved 13C NMR spectra were obtained, in which several carbon resonances of amino acids of the TMV coat protein subunits that are not observable by conventional high-resolution NMR spectroscopy can be designed. RNA resonance were absent, however, in the magic angle spinning 13C NMR spectra. Since three different binding sites are available for each nucleotide of the RNA, this is probably due to a line broadening caused by distributions of isotropic chemical shift values. In 13C-enriched TM 13C-13C dipolar interactions also gave rise to line broadening. By suitable pulse techniques that discriminate carbon resonances on the basis of their T1 and T1 rho values, it was possible to select particular groups of carbon nuclei with characteristic motional properties. Magic angle spinning 13C NMR spectra obtained with these pulse techniques are extremely well resolved.

Carbon Isotopes↗

PubMed2003

Manifestation of magic angle phenomenon: comparative study on effects of varying echo time and tendon orientation among various MR sequences.

The purpose of this study was to systematically investigate the effect of varying the echo time (TE) values and angle of the tendon to the main magnetic field (B(o)) upon the signal intensity observed with the magic angle phenomenon in tendons among most commonly used MR pulse sequences, including conventional spin echo (CSE), fast spin echo (FSE) and gradient echo (GRE) sequences. The intact bovine Achilles tendon was imaged using a clinical 1.5-T MR scanner. Magic angle phenomenon occurs in CSE, FSE and GRE sequences with different grade, appearing most severe in CSE, middle in FSE, and weakest in GRE sequence. In addition, the tendon signal changes produced by the magic angle phenomenon could be greatly reduced by increasing the TE to above a certain critical value in all three sequences. These critical TE values were different among CSE (40 msec), FSE (70 msec), and GRE (30 msec) sequences.

Achilles Tendon↗

PubMed2005

'Magic' nucleus 42Si.

Nuclear shell structures--the distribution of the quantum states of individual protons and neutrons--provide one of our most important guides for understanding the stability of atomic nuclei. Nuclei with 'magic numbers' of protons and/or neutrons (corresponding to closed shells of strongly bound nucleons) are particularly stable. Whether the major shell closures and magic numbers change in very neutron-rich nuclei (potentially causing shape deformations) is a fundamental, and at present open, question. A unique opportunity to study these shell effects is offered by the 42Si nucleus, which has 28 neutrons--a magic number in stable nuclei--and 14 protons. This nucleus has a 12-neutron excess over the heaviest stable silicon nuclide, and has only one neutron fewer than the heaviest silicon nuclide observed so far. Here we report measurements of 42Si and two neighbouring nuclei using a technique involving one- and two-nucleon knockout from beams of exotic nuclei. We present strong evidence for a well-developed proton subshell closure at Z = 14 (14 protons), the near degeneracy of two different (s(1/2) and d(3/2)) proton orbits in the vicinity of 42Si, and a nearly spherical shape for 42Si.

Journal Article↗

PubMed2005

Quantification of global orientational order in organic solids by magic-angle spinning deuterium NMR with rotor synchronization.

A new method for the characterization of orientational order in organic solids based on magic-angle spinning NMR spectroscopy is introduced. The method is related to the rotor-synchronized magic-angle spinning experiment proposed by Harbison and Spiess [Chem. Phys. Lett. 124, 128 (1986)], but exploits the anisotropy of the deuterium quadrupolar coupling instead of the carbon-13 chemical shielding anisotropy. Magic-angle spinning provides a sensitivity advantage over pseudostatic techniques; using the deuterium quadrupolar coupling makes the method applicable to systems that do not exhibit large carbon chemical shift anisotropies, such as aliphatic polymers. Due to the magnitude of the deuterium quadrupolar coupling, a large number of spinning sidebands can be reliably observed, allowing for a precise determination of the orientational distribution function. Experimental data are analyzed in terms of Wigner matrix basis functions as well as the conjugate orthogonal functions framework. Unidirectionally cold-drawn poly(ethylene) is used as an example to demonstrate the method.

Journal Article↗

PubMed1981

Changes in the structure of nuclei between the magic neutron numbers 50 and 82 as indicated by a rotating-cluster analysis of the energy values of the first 2 excited states of isotopes of cadmium, tin, and tellurium.

Values of R, the radius of rotation of the rotating cluster, are calculated from the observed values of the energy of the lowest 2(+) states of the even isotopes of (48)Cd, (50)Sn, and (52)Te with the assumption that the cluster is alpha, p(2), and alpha, respectively. R shows a maximum at approximately N = 58, a minimum at approximately N = 62, and a second maximum at approximately N = 70. The increase to the first maximum is interpreted as resulting from the overcrowding of spherons (alphas and tritons) in the mantle (outer layer) of the nuclei, causing the cluster to change from rotating in the mantle to skimming over its surface; the decrease to the minimum results from the addition of three dineutrons to the core, expanding the mantle and permitting the rotating cluster to begin to drop back into it; and the increase to the second maximum results from the overcrowding of the larger mantle surrounding the core containing the semi-magic number 14 of neutrons rather than the magic number 8 for N = 50. The decrease after the second maximum results from the further increase in the number of core neutrons to 20, corresponding to the magic number 82. Some additional evidence for the change to an intermediate structure between N = 50 and N = 82 is also discussed.

Journal Article↗

PubMed1992

Magic numbers for metallic clusters and the principle of maximum hardness.

It is shown that for relatively more stable metallic clusters (those with magic number of atoms) the chemical hardness (I-A) too is relatively larger. Thus the occurrence of magic numbers for metal clusters whose stability is determined by their electronic shell structure can be understood as a manifestation of the principle of maximum hardness. This may also represent a possible way of delineating clusters with stability dominated by their electronic shell structure from those for which the magic numbers occur as a result of their geometric structure.

Journal Article↗

PubMed2000

New magic number, N = 16, near the neutron drip line

We have surveyed the neutron separation energies (S(n)) and the interaction cross sections (sigma(I)) for the neutron-rich p-sd and the sd shell region. Very recently, both measurements reached up to the neutron drip line, or close to the drip line, for nuclei of Z</=8. A neutron-number dependence of S(n) shows clear breaks at N = 16 near the neutron drip line (T(Z)>/=3), which shows the creation of a new magic number. A neutron-number dependence of sigma(I) shows a large increase of sigma(I) for N = 15, which supports the new magic number. The origin of the new magic number is also discussed.

Journal Article↗

PubMed2001

AlH(3) and Al(2)H(6): magic clusters with unmagical properties.

Enhanced stability, low electron affinity, and high ionization potential are the hallmarks of a "magic" cluster. With an electron affinity of 0.28 eV, ionization potential of 11.43 eV, and a large binding energy, AlH(3) satisfies these criteria. However, unlike other magic clusters that interact only weakly with each other, two AlH(3) clusters bind to each other with an energy of 1.54 eV. The resulting Al(2)H(6), while also a magic cluster in its own right, possesses the most unusual property that the difference between its adiabatic and vertical detachment energy is about 2 eV--the largest of any known cluster. These results, based on density functional theory, are verified experimentally through photodetachment spectroscopy.

Journal Article↗