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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↗

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↗

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↗

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↗

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↗

PubMed2003

Doping of magic nanoclusters in the submonolayer In/Si(100) system.

Si(100)4 x 3-In reconstruction is essentially a superlattice of magic (identical-size) Si7In6 nanoclusters. Using scanning tunneling microscopy (STM) observations, we have found that under appropriate growth conditions up to 35% of these clusters can be modified; namely, two Si atoms in the cluster can be replaced by two In atoms, thus forming a Si5In8 cluster. This modification can be considered as a doping of the magic cluster, as it changes the electronic properties of the cluster from semiconducting towards metallic. The doped cluster is less rigid than the ordinary one and swings in the electrical field of the STM tip. The atomic structure and stability of the doped magic cluster have been examined using first-principles total-energy calculations.

Journal Article↗

PubMed2003

Giant Nernst effect and lock-in currents at magic angles in (TMTSF)2PF6.

We have measured the thermoelectric signal along the a axis in (TMTSF)2PF6 at 10 kbar as a function of the orientation of the applied magnetic field. Resonantlike Nernst signals were found with a dramatic sign change as the field was rotated through the "Lebed magic angles." The sign change indicates that the electrical current is "locked in" to the magic angle (interchain) directions for field alignment close to, but on either side of, the magic angles. The amplitude of signals near these angles is many orders of magnitude larger than expected from conventional Boltzmann transport theory.

Journal Article↗

PubMed1995

Solid-state magic-angle spinning 31P-NMR studies of native casein micelles.

Solid-state magic-angle spinning 31P-NMR spectroscopy was used to characterize the structure and composition of native casein micelles. The features of the magic-angle spinning 31P-NMR spectra, including overlapping resonances from mobile/immobile phosphorylated serine residues and inorganic calcium phosphates, have been determined using different experimental techniques and assigned by comparison with spectra of the presumed constituents within the casein micelle. Comparison with 31P-NMR spectra of alpha s1-, alpha s2-, and beta-caseins in dissolved and freeze-dried forms demonstrated that a major fraction of the phosphoserines in these proteins was in an immobilized state within the micelle. Likewise, from 31P-NMR spectra of the C-terminal part of kappa-casein, it was shown that this region of the micelle has a considerable conformational mobility. Finally, magic-angle spinning 31P-NMR spectra for a series of inorganic calcium phosphates and mineralized bone tissue revealed that the micellar inorganic calcium phosphates exhibit structural similarities to hydroxyapatite and hence resemble mineralized bone tissue.

Caseins↗

PubMed2001

Rapid and simple phenotypic assay for drug susceptibility of human immunodeficiency virus type 1 using CCR5-expressing HeLa/CD4(+) cell clone 1-10 (MAGIC-5).

We describe a rapid and simple novel phenotypic assay for drug susceptibility of human immunodeficiency virus type-1 (HIV-1) using a CCR5-expressing HeLa/CD4(+) cell clone 1-10 (MAGIC-5). MAGIC-5 cells produced large amounts of HIV-1 in culture supernatants, which enabled us to perform the phenotypic resistance assay. Determination of HIV-1 susceptibility to various protease inhibitors (PI) and nucleoside reverse transcriptase inhibitors was completed within 15 days in T-cell-tropic (X4) and macrophage-tropic (R5) viruses using fresh plasma samples containing at least 10(4) copies/ml. The nucleotide sequence of the envelope V3 region of HIV-1 in plasma was almost identical to that of the virus isolated by MAGIC-5 cells, suggesting a lack of selection bias in our assay. The assay variability was confined to within five-fold in all drugs examined. Accordingly, we used a 10-fold increase in the 50% inhibitory concentration as the cutoff value for viral resistance in the present assay. HIV-1 resistant to lamivudine, which was not detected by conventional genotypic assays, was isolated. In HIV-1 with PI-associated primary amino acid substitutions, our assay showed that drug resistance profiles correlated well with previously reported genotypic-assay data. Furthermore, our assay provided comprehensive results regarding PI resistance in the presence of multiple mutations. The novel assay successfully quantified the level of resistance of clinical HIV-1 isolates to a battery of anti-HIV drugs, indicating its clinical usefulness, particularly in patients who failed to respond to antiretroviral chemotherapy.

Amino Acid Sequence↗

PubMed1995

Increased signal in the normal supraspinatus tendon on MR imaging: diagnostic pitfall caused by the magic-angle effect.

OBJECTIVE: Increased signal intensity within the distal portion of the supraspinatus tendon during MR imaging is a frequent observation even in healthy subjects. This finding has been variously attributed to the presence of fat, muscle, connective tissue, abnormal vascularity, or degenerative changes. More recently, the effect of tendon orientation in the static magnetic field (Bo) has been implicated. It has been shown that tendons at the magic angle of 55 degrees to Bo show markedly increased signal. This study was designed to determine the contribution of the magic-angle effect to the MR signal in the distal portion of the supraspinatus tendon. SUBJECTS AND METHODS: Five healthy volunteers were imaged in a 1.5-T unit using short TR/TE sequences in standard supine position; they were then reimaged laterally flexed at the waist to reorient the plane of the distal portion of the supraspinatus tendon by approximately 20 degrees relative to Bo. In the second part of the study, three cadaveric shoulders were similarly imaged, first in standard position and then reoriented approximately 35 degrees by simple rotation of the specimen. The supraspinatus tendon was evaluated in each subject by noting the length of the segment with increased signal and the position of this segment relative to the insertion of the tendon on the greater tuberosity. Comparisons were made for each live and cadaveric subject between neutral and rotated positions. RESULTS: Segments of increased signal changed in length and position for each live and cadaveric subject from the neutral to the reoriented position. CONCLUSION: Our study suggests that tendon orientation contributes significantly to the presence of increased signal within the supraspinatus tendon, as caused by the magic-angle effect. Failure to recognize this effect may lead to diagnostic inaccuracy when evaluating the rotator cuff on short TR/TE sequences.

Adult↗

PubMed1994

Magical contagion and AIDS risk perception in a college population.

This study examined whether common reactions to AIDS are consistent with operation of the "magical law of contagion," a traditional belief that describes the transfer of properties, whether moral or physical, harmful or beneficial, through contact. Three features of magical contagion, explored in previous work, were re-examined. These features sometimes contrast with microbial contamination as described by modern germ theory. They are: permanence of effects; dose-insensitivity; and potential for effects to act backwards (i.e., from recipient back onto source). A fourth characteristic, previously unaddressed, was also explored: "moral-germ conflation," i.e., the tendency to incompletely distinguish illness from evil. Three hundred and ninety-nine college students completed a survey assessing each feature with regard to AIDS-related scenarios. Also assessed was general AIDS knowledge. Subjects were very well-informed about AIDS, yet a significant subset showed "magical" features of thinking. Consistent with moral-germ conflation, degree of worry about getting AIDS was better predicted by guilt than by risk behaviors and knowledge that they are risky. Implications are discussed.

Acquired Immunodeficiency Syndrome↗